45 results on '"Jones VJ"'
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2. Holocene deglaciation and glacier readvances on the Fildes Peninsula and King George Island (Isla 25 de Mayo), South Shetland Islands, NW Antarctic Peninsula
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Heredia Barión P, Roberts SJ, Spiegel C, Binnie SA, Wacker L, Davies J, Gabriel I, Jones VJ, Blockley S, Pearson EJ, Foster L, Davies SJ, Roland TP, Hocking EP, Bentley MJ, Hodgson DA, Hayward CL, McCulloch RD, Strelin JA, Kuhn G
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- 2023
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3. Regional variability in the atmospheric nitrogen deposition signal and its transfer to the sediment record in Greenland lakes
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Anderson, NJ, Curtis, CJ, Whiteford, EJ, Jones, VJ, McGowan, S, Simpson, GL, and Kaiser, J
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parasitic diseases - Abstract
Disruption of the nitrogen cycle is a major component of global environmental change. δ15N in lake sediments is increasingly used as a measure of reactive nitrogen input but problematically, the characteristic depleted δ15N signal is not recorded at all sites. We used a regionally replicated sampling strategy along a precipitation and N-deposition gradient in SW Greenland to assess the factors determining the strength of δ15N signal in lake sediment cores. Analyses of snowpack N and δ15N-NO3 and water chemistry were coupled with bulk sediment δ15N. Study sites cover a gradient of snowpack δ15N (ice sheet: −6‰; coast -10‰), atmospheric N deposition (ice sheet margin: ∼ 0.2 kg ha−1 yr−1; coast: 0.4 kg ha−1 yr−1) and limnology. Three 210Pb-dated sediment cores from coastal lakes showed a decline in δ15N of ca. -1‰ from ∼ 1860, reflecting the strongly depleted δ15N of snowpack N, lower in-lake total N (TN) concentration (∼ 300 μg N L−1) and a higher TN-load. Coastal lakes have 3.7–7.1× more snowpack input of nitrate than inland sites, while for total deposition the values are 1.7–3.6× greater for lake and whole catchment deposition. At inland sites and lakes close to the ice-sheet margin, a lower atmospheric N deposition rate and larger in-lake TN pool resulted in greater reliance on N-fixation and recycling (mean sediment δ15N is 0.5–2.5‰ in most inland lakes; n = 6). The primary control of the transfer of the atmospheric δ15N deposition signal to lake sediments is the magnitude of external N inputs relative to the in-lake N-pool.
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- 2018
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4. Were the Larsemann Hills ice-free through the Last Glacial Maximum?
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UCL, Hodgson, DA, Noon, PE, Vyverman, W, Bryant, CL, Gore, DB, Appleby, P, Gilmour, M, Verleyen, E, Sabbe, K, Jones, VJ, Ellis-Evans, JC, Wood, PB, UCL, Hodgson, DA, Noon, PE, Vyverman, W, Bryant, CL, Gore, DB, Appleby, P, Gilmour, M, Verleyen, E, Sabbe, K, Jones, VJ, Ellis-Evans, JC, and Wood, PB
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Lake sediments in the Larsemann Hills contain a great diversity of biological and physical markers from which past environments can be inferred. In order to determine the timing of environmental changes it is essential to have accurate dating of sediments. We used radiometric (Pb-210 and Cs-137), radiocarbon (AMS C-14) and uranium series (U-238) methods to date cores from eleven lakes. These were sampled on coastal to inland transects across the two main peninsulas, Broknes and Stornes, together with a single sample from the Bolingen Islands. Radiometric dating of recent sediments yielded Pb-210 levels below acceptable detection limits. However, a relatively well-defined peak in Cs-137 gave a date marker which corresponds to the fallout maximum from the atmospheric testing of atomic weapons in 1964/65. Radiocarbon (AMS 14C) measurements showed stratigraphical consistency in the age-depth sequences and undisturbed laminae in some cores provides evidence that the sediments have remained undisturbed by glacial action. In addition, freshwater surface sediments were found to be in near-equilibrium with modem C-14, and not influenced by radiocarbon contamination processes. This dating program, together with geomorphological records of ice flow directions and glacial sediments, indicates that parts of Broknes were ice-free throughout the Last Glacial Maximum and that some lakes have existed continuously since at least 44 ka BP. Attempts to date sediments older than 44 ka BP using U-238 dating were inconclusive. However, supporting evidence for Broknes being ice-free is provided by an Optically Stimulated Luminescence date from a glaciofluvial deposit. In contrast, Stornes only became ice-free in the mid to late Holocene. This contrasting glacial history results from the Dalk Glacier which diverts ice around Broknes. Lakes on Broknes and some offshore islands therefore contain the oldest known lacustrine sediment records from eastern Antarctica, with the area providing an i
- Published
- 2001
5. The Krakenes late-glacial palaeoenvironmental project
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Birks, HH, Battarbee, RW, Beerling, DJ, Birks, HJB, Brooks, SJ, Duigan, CA, Gulliksen, S, Haflidason, H, Hauge, F, Jones, VJ, Jonsgard, B, Karevik, M, Larsen, E, Lemdahl, G, Lovlie, R, Mangerud, J, Peglar, SM, Possnert, G, Smol, JP, Solem, JO, Solhoy, I, Solhoy, T, Sonstegaard, Birks, HH, Battarbee, RW, Beerling, DJ, Birks, HJB, Brooks, SJ, Duigan, CA, Gulliksen, S, Haflidason, H, Hauge, F, Jones, VJ, Jonsgard, B, Karevik, M, Larsen, E, Lemdahl, G, Lovlie, R, Mangerud, J, Peglar, SM, Possnert, G, Smol, JP, Solem, JO, Solhoy, I, Solhoy, T, and Sonstegaard
- Abstract
Krakenes is the site of a small lake on the west coast of Norway that contains a long sequence of late-glacial sediments. The Younger Dryas is well represented, as a cirque glacier developed in the catchment at this time. This site offers unique opportuni, Addresses: Birks HH, UNIV BERGEN, INST BOT, ALLEGATEN 41, N-5007 BERGEN, NORWAY. UNIV COLL LONDON, DEPT GEOG, ENVIRONM CHANGE RES CTR, LONDON WC1H 0AP, ENGLAND. UNIV SHEFFIELD, DEPT ANIM & PLANT SCI, SHEFFIELD S10 2TN, S YORKSHIRE, ENGLAND. NAT HIST MUSEU
- Published
- 1996
6. The transferability of diatoms to clothing and the methods appropriate for their collection and analysis in forensic geoscience
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Scott, KR, Morgan, RM, Jones, VJ, and Cameron, NG
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Diatoms ,Transfer ,GE ,Forensic geoscience ,Trace evidence ,Soil Collection procedure ,QE ,Collection procedure ,Pathology and Forensic Medicine - Abstract
Forensic geoscience is concerned with the analysis of geological materials in order to compare and exclude environmental samples from a common source, or to identify an unknown provenance in a criminal investigation. Diatom analysis is currently an underused technique within the forensic geoscience approach, which has the potential to provide an independent ecological assessment of trace evidence. This study presents empirical data to provide a preliminary evidence base in order to be able to understand the nature of diatom transfers to items of clothing, and the collection of transferred diatom trace evidence from a range of environments under experimental conditions. Three diatom extraction methods were tested on clothing that had been in contact with soil and water sites: rinsing in water (RW), rinsing in ethanol (RE), and submersion in H2O2 solution (H). Scanning electron microscopy (S.E.M.) analysis was undertaken in order to examine the degree of diatom retention on treated clothing samples. The total diatom yield and species richness data was recorded from each experimental sample in order to compare the efficacy of each method in collecting a representative sample for analysis. Similarity was explored using correspondence analysis. The results highlight the efficiency of H2O2 submersion in consistently extracting high diatom counts with representative species from clothing exposed to both aquatic and terrestrial sites. This is corroborated by S.E.M. analysis. This paper provides an important empirical evidence base for both establishing that diatoms do indeed transfer to clothing under forensic conditions in a range of environments, and in identifying that H2O2 extraction is the most efficient technique for the optimal collection of comparative samples. There is therefore potentially great value in collecting and analysing diatom components of geoforensic samples in order to aid in forensic investigation.
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7. The transfer of diatoms from freshwater to footwear materials: An experimental study assessing transfer, persistence, and extraction methods for forensic reconstruction
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Levin, EA, Morgan, RM, Scott, KR, and Jones, VJ
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GE ,RA1001 - Abstract
In recent years there has been growing interest in environmental forms of trace evidence, and ecological trace evidence collected from footwear has proved valuable within casework. Simultaneously, there has been growing awareness of the need for empirical experimentation to underpin forensic inferences. Diatoms are unicellular algae, and each cell (or ‘frustule’) consists of two valves which are made of silica, a robust material that favours their preservation both in sediments and within forensic scenarios. A series of experiments were carried out to investigate the transfer and persistence of diatoms upon common footwear materials, a recipient surface that has historically been overlooked by studies of persistence. The effectiveness of two novel extraction techniques (jet rinsing, and heating and agitation with distilled water) was compared to the established extraction technique of hydrogen peroxide digestion, for a suite of five common footwear materials: canvas, leather, and ‘suede’ (representing upper materials), and rubber and polyurethane (representing sole materials). It was observed that the novel extraction technique of heating and agitation with distilled water did not extract fewer diatom valves, or cause increased fragmentation of valves, when compared to peroxide digestion, suggesting that the method may be viable where potentially hazardous chemical reactions may be encountered with the peroxide digestion method.\ud \ud Valves could be extracted from all five footwear materials after 3 min of immersion, and more valves were extracted from the rougher, woven upper materials than the smoother sole materials. Canvas yielded the most valves (a mean of 2511/cm2) and polyurethane the fewest (a mean of 15/cm2). The persistence of diatoms on the three upper materials was addressed with a preliminary pilot investigation, with ten intervals sampled between 0 and 168 h. Valves were seen to persist in detectable quantities after 168 h on all three upper materials. However, some samples produced slides with no valves, and the earliest time after which no diatom valves were found was 4 h after the transfer. Analysis of the particle size distributions over time, by image analysis, suggests that the retention of diatoms may be size-selective; after 168 h, no particles larger than 200 μm2 could be found on the samples of canvas, and > 95% of the particles on the samples of suede were less than or equal to 200 μm2. A pilot investigation into the effects of immersion interval was carried out upon samples of canvas. Greater numbers of valves were extracted from the samples with longer immersion intervals, but even after 30 s, > 500 valves could be recovered per cm2, suggesting that footwear may be sampled for diatoms even if the contact with a water body may have been brief. These findings indicate that, if the variability within and between experimental runs can be addressed, there is significant potential for diatoms to be incorporated into the trace analysis of footwear and assist forensic reconstructions.
8. Benefits of information technology training to National Health Service staff in Wales.
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Warm DL, Thomas SE, Heard VR, Jones VJ, and Hawkins-Brown TM
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The use of computers in the National Health Service (UK) as a workplace is fundamental to its future. However, there is evidence of a paucity of information technology skills within the workforce and therefore, information technology skill training is essential. The National Health Service in Wales has been using the European Computer Driving Licence qualification to educate its staff in order to cover this skill gap. This paper reports on an evaluation of the perceived benefits to staff, both clinical and non-clinical, working for the National Health Service in Wales of information technology training through the European Computer Driving Licence qualification. Results show that there is an increase in confidence in terms of tasks undertaken but also towards other general life skills. Additionally, for those respondents with clinical contact, there is a perceived increase both in the time available with and the quality of care, given to patients. As the continued move towards a computer orientated healthcare system occurs, the information technology skills obtained through but not limited to training schemes such as European Computer Driving Licence will become of paramount importance, particularly as the single most important failure for technology-related projects in healthcare is a lack of readiness. [ABSTRACT FROM AUTHOR]
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- 2009
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9. Freshwater diatom persistence on clothing I: A quantitative assessment of trace evidence dynamics over time.
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Scott KR, Jones VJ, Cameron NG, Young JM, and Morgan RM
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- Forensic Sciences, Humans, Seasons, Specimen Handling, Clothing, Diatoms, Fresh Water
- Abstract
Freshwater diatoms offer valuable circumstantial forensic indicators, with a growing empirical research base aiming to identify and understand some of the spatial and temporal factors affecting their validity as trace evidence. Previous studies demonstrated that recipient surface characteristics, environmental variability, and individual species traits influence the initial transfer of freshwater diatoms to clothing. However, no previous research has sought to consider the impact of these and other variables on the persistence of transferred diatoms over investigative timescales. Therefore, this study aimed to identify and explore diatom retention dynamics on clothing following wear over time (hours to weeks). A series of experiments were designed to examine the impact of clothing material, seasonality, and time since wear (persistence interval) on the total number and species-richness of diatoms recovered and their relative retention (%) over time. Nine clothing swatches were immersed in a freshwater environment and then worn for one month in the spring. Subsamples were retrieved at regular intervals (e.g. 30 mins, 1 h, 8 h, 24 h) up to one month, diatoms were extracted using a H
2 O2 method, and examined microscopically. Three clothing materials were subject to the same experiment in the winter to generate a seasonal comparison. The results broadly identified three stages of diatom persistence on clothing - rapid initial loss, variable intermediate decay, and sustained long-term presence. Clothing material significantly impacted the number of diatoms recovered and retention dynamics over time, with complex interactions identified with seasonality. Although fewer diatoms were recovered in the winter, overall retention trends were consistent at the different times of year. The findings demonstrate that diatoms can be recovered from clothing, even weeks or months after an initial transfer, yielding a useful environmental trace indicator for forensic reconstructions over investigative timescales. The impact of clothing material and seasonality on persistence identified cotton, acrylic, and viscose clothing as the most reliable temporal repository of diatom trace evidence, with a more abundant forensic assemblage available for forensic comparisons in the spring., Competing Interests: Declaration of Competing Interest The authors declare no competing information or conflicts of interest., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)- Published
- 2021
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10. Freshwater diatom persistence on clothing II: Further analysis of species assemblage dynamics over investigative timescales.
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Scott KR, Jones VJ, Cameron NG, Young JM, and Morgan RM
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Diatoms are a useful form of environmental trace evidence, yielding a circumstantial link between persons and scenes of forensic interest. A developing empirical research base has sought to understand those factors affecting the transfer and persistence of freshwater diatoms on clothing and footwear surfaces. Although an initial study has demonstrated that diatoms can persist on clothing following weeks of wear, no previous research has explored the temporal dynamics of a persistent species assemblage over timescales pertinent to forensic investigations. This study therefore aimed to determine if: (1) valve morphology (size and shape) influences diatom persistence, (2) the relative abundance of taxa within an assemblage affects retention, and (3) a persistent diatom assemblage retrieved from clothing after one month can reliably be compared to the site of initial transfer. To build on previous research findings which highlighted the impact of substrate and environmental seasonality on diatom transfer and persistence, here, nine clothing materials were tested in spring before a seasonal comparison in the winter. Fabric swatches were immersed in a freshwater river, worn attached to clothing, and subsamples retrieved at regular intervals (hours, days, weeks) up to one month post-immersion. Diatoms were extracted using a H
2 O2 technique and analysed via microscopy. The results indicated that smaller diatoms (< 10 µm) are retained in significantly greater abundance, with no statistically significant difference between centric and pennate diatom loss over time. Although a persistent species assemblage was relatively stable over the one month of wear, significant differences were identified between clothing substrate in the spring and between the seasonal samples. The most abundant environmental taxa were consistently identified in the forensic samples, with greater variability attributed to the retention of relatively less common species. The findings suggest that, despite a loss in the abundance and species-richness of diatoms retrieved from clothing over time, a persistent assemblage may provide a useful circumstantial link to the site of initial transfer. The complex relationships between clothing type, environmental seasonality, and time since wear on retention, emphasise the need for diatom trace evidence to be carefully interpreted within an exclusionary framework, and the significance of any casework findings to be determined with reference to empirical evidence bases., Competing Interests: Conflict of interest The authors declare no competing information or conflicts of interest., (Copyright © 2021 The Author(s). Published by Elsevier B.V. All rights reserved.)- Published
- 2021
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11. What to Do? Predicting Coping Strategies Following Ingroup Members' Stereotypical Behaviors in Interracial Interactions.
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Taylor VJ, Yantis C, Bonam C, and Hart A
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- Adaptation, Psychological, Anxiety, Emotions, Humans, Black or African American, White People
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The current studies examine how witnessing stereotype-confirming ingroup behavior affects black Americans' interactions with white Americans. Across three studies, black Americans indicated metaperceptual, emotional, and behavioral responses to witnessing a black person's stereotypically negative, stereotypically positive, or nonstereotypically neutral behavior during an interracial (vs. intraracial) interaction. Following an ingroup member's stereotypically negative (vs. stereotypically positive in Study 1, or nonstereotypically neutral in Studies 2-3) behavior during an interracial interaction, black Americans expressed greater metastereotypes, which increased intergroup anxiety, ultimately eliciting nuanced coping strategies: engagement/overcompensation, antagonism, freezing, or avoidance. Psychological resources attenuated anxiety's effect on engagement/overcompensation (Studies 2-3) and freezing (Study 3). Both patterns were stronger in interracial (vs. intraracial) interactions (Study 3). This research demonstrates the central role of metaperceptions in interracial interactions, highlighting how stereotypically negative behaviors of nearby ingroup members are impactful situational stressors that affect behavioral intentions in intergroup encounters.
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- 2021
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12. Open science, communal culture, and women's participation in the movement to improve science.
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Murphy MC, Mejia AF, Mejia J, Yan X, Cheryan S, Dasgupta N, Destin M, Fryberg SA, Garcia JA, Haines EL, Harackiewicz JM, Ledgerwood A, Moss-Racusin CA, Park LE, Perry SP, Ratliff KA, Rattan A, Sanchez DT, Savani K, Sekaquaptewa D, Smith JL, Taylor VJ, Thoman DB, Wout DA, Mabry PL, Ressl S, Diekman AB, and Pestilli F
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- Authorship, Humans, Information Dissemination, Open Access Publishing, Reproducibility of Results, Science trends, Women
- Abstract
Science is undergoing rapid change with the movement to improve science focused largely on reproducibility/replicability and open science practices. This moment of change-in which science turns inward to examine its methods and practices-provides an opportunity to address its historic lack of diversity and noninclusive culture. Through network modeling and semantic analysis, we provide an initial exploration of the structure, cultural frames, and women's participation in the open science and reproducibility literatures ( n = 2,926 articles and conference proceedings). Network analyses suggest that the open science and reproducibility literatures are emerging relatively independently of each other, sharing few common papers or authors. We next examine whether the literatures differentially incorporate collaborative, prosocial ideals that are known to engage members of underrepresented groups more than independent, winner-takes-all approaches. We find that open science has a more connected, collaborative structure than does reproducibility. Semantic analyses of paper abstracts reveal that these literatures have adopted different cultural frames: open science includes more explicitly communal and prosocial language than does reproducibility. Finally, consistent with literature suggesting the diversity benefits of communal and prosocial purposes, we find that women publish more frequently in high-status author positions (first or last) within open science (vs. reproducibility). Furthermore, this finding is further patterned by team size and time. Women are more represented in larger teams within reproducibility, and women's participation is increasing in open science over time and decreasing in reproducibility. We conclude with actionable suggestions for cultivating a more prosocial and diverse culture of science., Competing Interests: The authors declare no competing interest., (Copyright © 2020 the Author(s). Published by PNAS.)
- Published
- 2020
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13. Long-term ecological changes in Mediterranean mountain lakes linked to recent climate change and Saharan dust deposition revealed by diatom analyses.
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Pérez-Martínez C, Rühland KM, Smol JP, Jones VJ, and Conde-Porcuna JM
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- Africa, Northern, Climate Change, Dust, Ecosystem, Spain, Diatoms, Lakes
- Abstract
Anthropogenic climate change and the recent increase of Saharan dust deposition has had substantial effects on Mediterranean alpine regions. We examined changes in diatom assemblage composition over the past ~180 years from high-resolution, dated sediment cores retrieved from six remote lakes in the Sierra Nevada Mountains of Southern Spain. In all lakes, changes in diatom composition began over a century ago, but were more pronounced after ~1970 CE, concurrent with trends in rising regional air temperature, declining precipitation, and increased Saharan dust deposition. Temperature was identified as the main predictor of diatom assemblage changes, whereas both Saharan dust deposition drivers, the Sahel precipitation index and the winter North Atlantic Oscillation, were secondary explanatory variables. Diatom compositional shifts are indicative of lake alkalinization (linked to heightened evapoconcentration and an increase in calcium-rich Saharan dust input) and reduced lake water turbulence (linked to lower water levels and reduced inflows to the lakes). Moreover, decreases in epiphytic diatom species were indicative of increasing aridity and the drying of catchment meadows. Our results support the conclusions of previous chlorophyll-a and cladoceran-based paleolimnological analyses of these same dated sedimentary records which show a regional-scale response to climate change and Saharan dust deposition in Sierra Nevada lakes and their catchments during the 20th century. However, diatom assemblages seem to respond to different atmospheric and climate-related effects than cladoceran assemblages and chlorophyll-a concentrations. The recent impact of climate change and atmospheric Saharan deposition on lake biota assemblages and water chemistry, as well as catchment water availability, will have important implications for the valuable ecosystem services that the Sierra Nevada provides., Competing Interests: Declaration of competing interest The authors certify that there is no actual or potential conflict of interest in relation to this article., (Copyright © 2020 Elsevier B.V. All rights reserved.)
- Published
- 2020
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14. Freshwater diatom transfer to clothing: Spatial and temporal influences on trace evidence in forensic reconstructions.
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Scott KR, Morgan RM, Cameron NG, and Jones VJ
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- Forensic Sciences methods, Fresh Water analysis, Microscopy methods, Seasons, Clothing, Diatoms classification, Diatoms isolation & purification, Spatio-Temporal Analysis
- Abstract
Environmental indicators are increasingly sought and analysed in a range of forensic reconstructions. Although the majority of casework and research studies are concerned with the criminal investigation of terrestrial habitats (soils, sediments, plants etc.), freshwater environments are also frequently encountered as crime scenes. As such, microalgae, particularly diatoms, may provide useful circumstantial trace evidence following their transfer to a victim or perpetrator. Diatom analysis is a relatively underused technique in forensic ecology, although an increased empirical research focus is beginning to recognise the evidential value of a transferred assemblage. This study aimed to examine three of the spatial and temporal variables known to influence the extent of an initial transfer of trace particulates, within the context of freshwater diatoms to clothing. A series of experiments were designed to consider the impact of recipient surface characteristics (clothing type), source environment conditions (seasonality), and morphological (type of diatom) variability, on the total number (no. per cm
2 ) and species richness (total no. sp.) of an evidential diatom sample recovered from clothing. Nine commonly used clothing materials were immersed in a freshwater river at three times of year - the early and late spring and in the winter. Diatoms were recovered using a H2 O2 extraction technique and examined microscopically. The results demonstrated that diatom transfer to clothing varies significantly, with a greater abundance and a higher species richness transferred to coarse woven surfaces including acrylic, linen, and viscose. Significantly fewer diatoms were transferred to clothing in the winter, in line with seasonal fluctuations in the source environment diatom community. Furthermore, variation in the relative abundance of particular diatom species was identified between clothing types, provisionally suggesting that morphological characteristics may also support or limit the transfer of material. These findings highlight that, although clothing may offer a valuable repository of freshwater diatom trace evidence, the interpretation of evidential material should be approached within an exclusionary framework. Thus, empirical data has been generated to develop evidence bases within forensic ecology, demonstrating some of the spatial and temporal factors which may contribute to or limit the transfer of evidence., (Copyright © 2018 The Chartered Society of Forensic Sciences. Published by Elsevier B.V. All rights reserved.)- Published
- 2019
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15. A Comparison of Thresholding Methods for Forensic Reconstruction Studies Using Fluorescent Powder Proxies for Trace Materials.
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Levin EA, Morgan RM, Griffin LD, and Jones VJ
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Image segmentation is a fundamental precursor to quantitative image analysis. At present, no standardised methodology exists for segmenting images of fluorescent proxies for trace evidence. Experiments evaluated (i) whether manual segmentation is reproducible within and between examiners (with three participants repeatedly tracing three images) (ii) whether manually defining a threshold level offers accurate and reproducible results (with 20 examiners segmenting 10 images), and (iii) whether a global thresholding algorithm might perform with similar accuracy, while offering improved reproducibility and efficiency (16 algorithms tested). Statistically significant differences were seen between examiners' traced outputs. Manually thresholding produced good accuracy on average (within ±1% of the expected values), but poor reproducibility (with multiple outliers). Three algorithms (Yen, MaxEntropy, and RenyiEntropy) offered similar accuracy, with improved reproducibility and efficiency. Together, these findings suggest that appropriate algorithms could perform thresholding tasks as part of a robust workflow for reconstruction studies employing fluorescent proxies for trace evidence., (© 2018 The Authors Journal of Forensic Sciences published by Wiley Periodicals, Inc. on behalf of American Academy of Forensic Sciences.)
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- 2019
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16. "A threat on the ground": The consequences of witnessing stereotype-confirming ingroup members in interracial interactions.
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Taylor VJ, Garcia RL, Shelton JN, and Yantis C
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- Adult, Female, Humans, Male, Minority Groups, Young Adult, Black or African American psychology, Interpersonal Relations, Racism, Stereotyping, White People psychology
- Abstract
Objectives: Three studies explored interpersonal consequences of engaging in interracial interactions after witnessing racial ingroup members' stereotypical behavior., Method: Study 1 used experience-sampling methodology to assess ethnic minority students' (n = 119) intergroup anxiety, metastereotypes, and anticipatory behaviors following one of three types of interpersonal interactions: (a) a White person and a racial ingroup member who had behaved stereotypically, (b) a White person and a nonstereotypical ingroup member, or (c) neither. Studies 2 (n = 273) and 3 (n = 379) experimentally examined whether witnessing an ingroup member's stereotypically negative behavior in interracial interactions, compared to stereotypically positive (Study 2) or nonstereotypically negative behavior (Study 3) differentially affected anxiety, metastereotypes, and anticipatory behaviors in interracial versus intraracial interactions among Black Americans., Results: In Study 1, minorities reported greater anxiety, metastereotypes, and motivation to disprove stereotypes, but less interest in future interracial contact, following interracial interactions involving stereotype-confirming ingroup members compared to other interactions. In Studies 2 and 3, adverse interaction consequences were most severe when ingroup behavior was both negative and stereotypical compared to neutral, stereotypically positive, and nonstereotypically negative ingroup behavior. Additionally, metastereotypes (and, to a lesser degree, anxiety) mediated individuals' motivation to disprove stereotypes and desire future interactions with White witnesses following stereotypically negative ingroup behavior in interracial (vs. intraracial) interactions., Conclusions: This research highlights the emotional, metaperceptual, and motivational outcomes following ingroup members' stereotypical behavior in intergroup contexts that extend beyond dyadic encounters. (PsycINFO Database Record, ((c) 2018 APA, all rights reserved).)
- Published
- 2018
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17. Functional attributes of epilithic diatoms for palaeoenvironmental interpretations in South-West Greenland lakes.
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McGowan S, Gunn HV, Whiteford EJ, John Anderson N, Jones VJ, and Law AC
- Abstract
Benthic diatoms are commonly used for palaeoenvironmental reconstruction in Arctic regions, but interpretation of their ecology remains challenging. We studied epilithic diatom assemblages from the shallow margins of 19 lakes from three areas (coast-inland-ice sheet margin) along a climate gradient in Kangerlussuaq, West Greenland during two periods; shortly after ice-off (spring) and in the middle of the growth season (summer). We aimed to understand the distribution of Arctic epilithic diatoms in relation to water chemistry gradients during the two seasons, to investigate their incorporation into lake sediments and to assess their applicability as palaeoenvironmental indicators. Diatoms were correlated with nutrients in the spring and alkalinity/major ions in the summer, when nutrients were depleted; approximately half of the variance explained was independent of spatial factors. When categorised by functional attributes, diatom seasonal succession differed among regions with the most obvious changes in inland lakes where summer temperatures are warmer, organic nutrient processing is prevalent and silicate is limiting. These conditions led to small, motile and adnate diatoms being abundant in inland lakes during the summer ( Nitzschia spp., Encyonopsis microcephala ), as these functional attributes are suited to living within complex mats of non-siliceous microbial biofilms. Seasonal succession in silica-rich lakes at the coast was less pronounced and assemblages included Tabellaria flocculosa (indicating more acidic conditions) and Hannaea arcus (indicating input from inflowing rivers). The nitrogen-fixing diatom Epithemia sorex increased from the coast to the ice sheet, negatively correlating with a gradient of reactive nitrogen. The presence of this diatom in Holocene sediment records alongside cyanobacterial carotenoids during arid periods of low nitrogen delivery, suggests that it is a useful indicator of nitrogen limitation. Nitzschia species appear to be associated with high concentrations of organic carbon and heterotrophy, but their poor representation in West Greenland lake sediments due to taphonomic processes limits their palaeoenvironmental application in this region. Proportions of epilithic taxa in lake sediment records of coastal lakes increased during some wetter periods of the Holocene, suggesting that snowpack-derived nutrient delivery may offer diatom taxa living at lake margins a competitive advantage over planktonic diatoms during the "moating" ice melt period. Thus, further research investigating linkages between epilithic diatoms, snowpack and nutrient delivery in seasonally frozen lakes is recommended as these taxa live on the 'front-line' during the spring and may be especially sensitive to changes in snowmelt conditions.
- Published
- 2018
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18. Types and Factors Associated With Online Health Information Seeking Among College Men in Latino Fraternities: A Qualitative Study.
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Chavarria EA, Chaney EH, Stellefson ML, Chaney JD, Chavarria N, and Dodd VJ
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- Adult, Florida, Focus Groups, Humans, Male, Men's Health, Qualitative Research, Young Adult, College Fraternities and Sororities, Hispanic or Latino, Information Seeking Behavior, Internet
- Abstract
Despite the fact that a large percentage of Americans go online to seek health information, literature pertaining to online health information (OHI) seeking among college men in Latino fraternities (CMLF) has been nonexistent. Thus, the purpose of this study was to (a) identify the types of OHI that CMLF seek and (b) to determine the factors motivating OHI seeking among CMLF. Four 1- to 1.5-hour focus groups were conducted in two public universities in Florida with 41 college-aged Latino males in an established Latino fraternity. E-mails were used to recruit fraternity members. Qualitative analysis of the focus group transcripts identified that CMLF search for a variety of OHI types including searches on symptoms, diagnoses, weight loss, and treatments for conditions or diseases among other types of OHI. Factors motivating OHI seeking included informational needs of others and concerns for others, worries due to lack of health insurance, preoccupations with health condition, concerns over physical appearance, and clarification through social media. CMLF may be elicited to serve as information conduits to increase access to health information on chronic diseases for older non-English-speaking Latino adults. Lack of health insurance along with other factors in this segment of the population have led to self-diagnosis and self-treatment of illness. Thus, empirical research and health promotion on the potential risks due to self-diagnosing and self-treatment of illness is warranted among CMLF.
- Published
- 2017
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19. The transfer of diatoms from freshwater to footwear materials: An experimental study assessing transfer, persistence, and extraction methods for forensic reconstruction.
- Author
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Levin EA, Morgan RM, Scott KR, and Jones VJ
- Subjects
- Forensic Sciences, Humans, Immersion, Diatoms isolation & purification, Fresh Water, Shoes, Specimen Handling methods
- Abstract
In recent years there has been growing interest in environmental forms of trace evidence, and ecological trace evidence collected from footwear has proved valuable within casework. Simultaneously, there has been growing awareness of the need for empirical experimentation to underpin forensic inferences. Diatoms are unicellular algae, and each cell (or 'frustule') consists of two valves which are made of silica, a robust material that favours their preservation both in sediments and within forensic scenarios. A series of experiments were carried out to investigate the transfer and persistence of diatoms upon common footwear materials, a recipient surface that has historically been overlooked by studies of persistence. The effectiveness of two novel extraction techniques (jet rinsing, and heating and agitation with distilled water) was compared to the established extraction technique of hydrogen peroxide digestion, for a suite of five common footwear materials: canvas, leather, and 'suede' (representing upper materials), and rubber and polyurethane (representing sole materials). It was observed that the novel extraction technique of heating and agitation with distilled water did not extract fewer diatom valves, or cause increased fragmentation of valves, when compared to peroxide digestion, suggesting that the method may be viable where potentially hazardous chemical reactions may be encountered with the peroxide digestion method. Valves could be extracted from all five footwear materials after 3min of immersion, and more valves were extracted from the rougher, woven upper materials than the smoother sole materials. Canvas yielded the most valves (a mean of 2511/cm
2 ) and polyurethane the fewest (a mean of 15/cm2 ). The persistence of diatoms on the three upper materials was addressed with a preliminary pilot investigation, with ten intervals sampled between 0 and 168h. Valves were seen to persist in detectable quantities after 168h on all three upper materials. However, some samples produced slides with no valves, and the earliest time after which no diatom valves were found was 4h after the transfer. Analysis of the particle size distributions over time, by image analysis, suggests that the retention of diatoms may be size-selective; after 168h, no particles larger than 200μm2 could be found on the samples of canvas, and >95% of the particles on the samples of suede were less than or equal to 200μm2 . A pilot investigation into the effects of immersion interval was carried out upon samples of canvas. Greater numbers of valves were extracted from the samples with longer immersion intervals, but even after 30s, >500 valves could be recovered per cm2 , suggesting that footwear may be sampled for diatoms even if the contact with a water body may have been brief. These findings indicate that, if the variability within and between experimental runs can be addressed, there is significant potential for diatoms to be incorporated into the trace analysis of footwear and assist forensic reconstructions., (Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.)- Published
- 2017
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20. Transcriptional targets of TWIST1 in the cranial mesoderm regulate cell-matrix interactions and mesenchyme maintenance.
- Author
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Bildsoe H, Fan X, Wilkie EE, Ashoti A, Jones VJ, Power M, Qin J, Wang J, Tam PPL, and Loebel DAF
- Subjects
- Animals, Binding Sites, Cell Differentiation, Cell Line, Dogs, Epithelial-Mesenchymal Transition genetics, Extracellular Matrix metabolism, Gene Expression Regulation, Developmental, Madin Darby Canine Kidney Cells, Mesenchymal Stem Cells metabolism, Mice, Mice, Knockout, Morphogenesis genetics, Nuclear Proteins biosynthesis, Twist-Related Protein 1 biosynthesis, Extracellular Matrix genetics, Mesoderm growth & development, Neural Crest embryology, Nuclear Proteins genetics, Skull embryology, Twist-Related Protein 1 genetics
- Abstract
TWIST1, a basic helix-loop-helix transcription factor is essential for the development of cranial mesoderm and cranial neural crest-derived craniofacial structures. We have previously shown that, in the absence of TWIST1, cells within the cranial mesoderm adopt an abnormal epithelial configuration via a process reminiscent of a mesenchymal to epithelial transition (MET). Here, we show by gene expression analysis that loss of TWIST1 in the cranial mesoderm is accompanied by a reduction in the expression of genes that are associated with cell-extracellular matrix interactions and the acquisition of mesenchymal characteristics. By comparing the transcriptional profiles of cranial mesoderm-specific Twist1 loss-of-function mutant and control mouse embryos, we identified a set of genes that are both TWIST1-dependent and predominantly expressed in the mesoderm. ChIP-seq was used to identify TWIST1-binding sites in an in vitro model of a TWIST1-dependent mesenchymal cell state, and the data were combined with the transcriptome data to identify potential target genes. Three direct transcriptional targets of TWIST1 (Ddr2, Pcolce and Tgfbi) were validated by ChIP-PCR using mouse embryonic tissues and by luciferase assays. Our findings reveal that the mesenchymal properties of the cranial mesoderm are likely to be regulated by a network of TWIST1 targets that influences the extracellular matrix and cell-matrix interactions, and collectively they are required for the morphogenesis of the craniofacial structures., (Copyright © 2016 Elsevier Inc. All rights reserved.)
- Published
- 2016
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21. Dataset of TWIST1-regulated genes in the cranial mesoderm and a transcriptome comparison of cranial mesoderm and cranial neural crest.
- Author
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Bildsoe H, Fan X, Wilkie EE, Ashoti A, Jones VJ, Power M, Qin J, Wang J, Tam PP, and Loebel DA
- Abstract
This article contains data related to the research article entitled "Transcriptional targets of TWIST1 in the cranial mesoderm regulate cell-matrix interactions and mesenchyme maintenance" by Bildsoe et al. (2016) [1]. The data presented here are derived from: (1) a microarray-based comparison of sorted cranial mesoderm (CM) and cranial neural crest (CNC) cells from E9.5 mouse embryos; (2) comparisons of transcription profiles of head tissues from mouse embryos with a CM-specific loss-of-function of Twist1 and control mouse embryos collected at E8.5 and E9.5; (3) ChIP-seq using a TWIST1-specific monoclonal antibody with chromatin extracts from TWIST1-expressing MDCK cells, a model for a TWIST1-dependent mesenchymal state.
- Published
- 2016
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22. Thyroid bud morphogenesis requires CDC42- and SHROOM3-dependent apical constriction.
- Author
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Loebel DA, Plageman TF Jr, Tang TL, Jones VJ, Muccioli M, and Tam PP
- Abstract
Early development of the gut endoderm and its subsequent remodeling for the formation of organ buds are accompanied by changes to epithelial cell shape and polarity. Members of the Rho-related family of small GTPases and their interacting proteins play multiple roles in regulating epithelial morphogenesis. In this study we examined the role of Cdc42 in foregut development and organ bud formation. Ablation of Cdc42 in post-gastrulation mouse embryos resulted in a loss of apical-basal cell polarity and columnar epithelial morphology in the ventral pharyngeal endoderm, in conjunction with a loss of apical localization of the known CDC42 effector protein PARD6B. Cell viability but not proliferation in the foregut endoderm was impaired. Outgrowth of the liver, lung and thyroid buds was severely curtailed in Cdc42-deficient embryos. In particular, the thyroid bud epithelium did not display the apical constriction that normally occurs concurrently with the outgrowth of the bud into the underlying mesenchyme. SHROOM3, a protein that interacts with Rho GTPases and promotes apical constriction, was strongly expressed in the thyroid bud and its sub-cellular localization was disrupted in Cdc42-deficient embryos. In Shroom3 gene trap mutant embryos, the thyroid bud epithelium showed no apical constriction, while the bud continued to grow and protruded into the foregut lumen. Our findings indicate that Cdc42 is required for epithelial polarity and organization in the endoderm and for apical constriction in the thyroid bud. It is possible that the function of CDC42 is partly mediated by SHROOM3., (© 2016. Published by The Company of Biologists Ltd.)
- Published
- 2016
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23. Parent Training Intervention to Manage Externalizing Behaviors in Children With Autism.
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Sellinger VJ and Elder JH
- Subjects
- Adult, Child, Female, Humans, Autistic Disorder psychology, Child Behavior Disorders therapy, Parents education
- Abstract
Children with autism spectrum disorder (ASD) are more likely than their typically developing peers to exhibit externalizing behaviors; however, the etiology in children with ASD may be different and related to the core deficits of the disorder. Although parent training interventions have been effective in decreasing externalizing behaviors in typically developing children, the effectiveness in children with ASD has not been established. An in-depth analysis of the child's behavior may provide the foundation upon which to develop an individualized parent training approach. This case study illustrates how a functional assessment interview was used to obtain in-depth information about externalizing behaviors exhibited by a child with ASD who is high functioning and how this information was used to develop an individualized parent training intervention., (Copyright © 2016 National Association of Pediatric Nurse Practitioners. Published by Elsevier Inc. All rights reserved.)
- Published
- 2016
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24. Context-specific function of the LIM homeobox 1 transcription factor in head formation of the mouse embryo.
- Author
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Fossat N, Ip CK, Jones VJ, Studdert JB, Khoo PL, Lewis SL, Power M, Tourle K, Loebel DA, Kwan KM, Behringer RR, and Tam PP
- Subjects
- Animals, Cadherins metabolism, Endoderm cytology, Endoderm metabolism, Gene Deletion, Gene Expression Regulation, Developmental, Germ Layers cytology, Germ Layers metabolism, LIM-Homeodomain Proteins genetics, Mice, Knockout, Models, Biological, Mutation, Phenotype, Signal Transduction, Transcription Factors genetics, Wnt Proteins metabolism, Embryo, Mammalian metabolism, Head embryology, LIM-Homeodomain Proteins metabolism, Transcription Factors metabolism
- Abstract
Lhx1 encodes a LIM homeobox transcription factor that is expressed in the primitive streak, mesoderm and anterior mesendoderm of the mouse embryo. Using a conditional Lhx1 flox mutation and three different Cre deleters, we demonstrated that LHX1 is required in the anterior mesendoderm, but not in the mesoderm, for formation of the head. LHX1 enables the morphogenetic movement of cells that accompanies the formation of the anterior mesendoderm, in part through regulation of Pcdh7 expression. LHX1 also regulates, in the anterior mesendoderm, the transcription of genes encoding negative regulators of WNT signalling, such as Dkk1, Hesx1, Cer1 and Gsc. Embryos carrying mutations in Pcdh7, generated using CRISPR-Cas9 technology, and embryos without Lhx1 function specifically in the anterior mesendoderm displayed head defects that partially phenocopied the truncation defects of Lhx1-null mutants. Therefore, disruption of Lhx1-dependent movement of the anterior mesendoderm cells and failure to modulate WNT signalling both resulted in the truncation of head structures. Compound mutants of Lhx1, Dkk1 and Ctnnb1 show an enhanced head truncation phenotype, pointing to a functional link between LHX1 transcriptional activity and the regulation of WNT signalling. Collectively, these results provide comprehensive insight into the context-specific function of LHX1 in head formation: LHX1 enables the formation of the anterior mesendoderm that is instrumental for mediating the inductive interaction with the anterior neuroectoderm and LHX1 also regulates the expression of factors in the signalling cascade that modulate the level of WNT activity., (© 2015. Published by The Company of Biologists Ltd.)
- Published
- 2015
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25. "Two souls, two thoughts," two self-schemas: double consciousness can have positive academic consequences for African Americans.
- Author
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Brannon TN, Markus HR, and Taylor VJ
- Subjects
- Adult, Female, Humans, Male, Young Adult, Achievement, Black or African American ethnology, Consciousness, Cultural Diversity, Social Identification
- Abstract
African Americans can experience a double consciousness-the two-ness of being an American and an African American. The present research hypothesized that: (a) double consciousness can function as 2 self-schemas-an independent self-schema tied to mainstream American culture and an interdependent self-schema tied to African American culture, and (b) U.S. educational settings can leverage an interdependent self-schema associated with African American culture through inclusive multicultural practices to facilitate positive academic consequences. First, a pilot experiment and Studies 1 and 2 provided evidence that double consciousness can be conceptualized as 2 self-schemas. That is, African Americans shifted their behavior (e.g., cooperation) in schema-relevant ways from more independent when primed with mainstream American culture to more interdependent when primed with African American culture. Then, Studies 3 and 4 demonstrated that incorporating African American culture within a university setting enhanced African Americans' persistence and performance on academic-relevant tasks. Finally, using the Gates Millennium Scholars dataset (Cohort 1), Study 5 conceptually replicated Studies 3 and 4 and provided support for one process that underlies the observed positive academic consequences. Specifically, Study 5 provided evidence that engagement with African American culture (e.g., involvement with cultural events/groups) on college campuses makes an interdependent self-schema more salient that increases African American students' sense of academic fit and identification, and, in turn, enhances academic performance (self-reported grades) and persistence (advanced degree enrollment in a long-term follow-up). The discussion examines double consciousness as a basic psychological phenomenon and suggests the intra- and intergroup benefits of inclusive multicultural settings., ((c) 2015 APA, all rights reserved).)
- Published
- 2015
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26. Reply to A. Dragutinovic, 'A reply to: The transferability of diatoms to clothing and the methods appropriate for their collection and analysis in forensic geoscience Forensic Sci. Int. 241 (2014) 127-137'.
- Author
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Scott KR, Morgan RM, Jones VJ, and Cameron NG
- Subjects
- Humans, Clothing, Diatoms, Specimen Handling methods
- Published
- 2015
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27. The transferability of diatoms to clothing and the methods appropriate for their collection and analysis in forensic geoscience.
- Author
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Scott KR, Morgan RM, Jones VJ, and Cameron NG
- Subjects
- Ethanol, Humans, Hydrogen Peroxide, Microscopy, Electron, Scanning, Oxidants, Ponds, Soil, Solvents, Water, Clothing, Diatoms, Specimen Handling methods
- Abstract
Forensic geoscience is concerned with the analysis of geological materials in order to compare and exclude environmental samples from a common source, or to identify an unknown provenance in a criminal investigation. Diatom analysis is currently an underused technique within the forensic geoscience approach, which has the potential to provide an independent ecological assessment of trace evidence. This study presents empirical data to provide a preliminary evidence base in order to be able to understand the nature of diatom transfers to items of clothing, and the collection of transferred diatom trace evidence from a range of environments under experimental conditions. Three diatom extraction methods were tested on clothing that had been in contact with soil and water sites: rinsing in water (RW), rinsing in ethanol (RE), and submersion in H2O2 solution (H). Scanning electron microscopy (S.E.M.) analysis was undertaken in order to examine the degree of diatom retention on treated clothing samples. The total diatom yield and species richness data was recorded from each experimental sample in order to compare the efficacy of each method in collecting a representative sample for analysis. Similarity was explored using correspondence analysis. The results highlight the efficiency of H2O2 submersion in consistently extracting high diatom counts with representative species from clothing exposed to both aquatic and terrestrial sites. This is corroborated by S.E.M. analysis. This paper provides an important empirical evidence base for both establishing that diatoms do indeed transfer to clothing under forensic conditions in a range of environments, and in identifying that H2O2 extraction is the most efficient technique for the optimal collection of comparative samples. There is therefore potentially great value in collecting and analysing diatom components of geoforensic samples in order to aid in forensic investigation., (Copyright © 2014 The Authors. Published by Elsevier Ireland Ltd.. All rights reserved.)
- Published
- 2014
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28. Older Adults and Diabetes: Preface.
- Author
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Briscoe VJ
- Published
- 2014
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29. Analyzing gene function in whole mouse embryo and fetal organ in vitro.
- Author
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Tanaka SS, Yamaguchi YL, Jones VJ, and Tam PP
- Subjects
- Animals, Electroporation, Embryo, Mammalian cytology, Gene Expression Regulation, Developmental, Gene Targeting, Mice, Molecular Biology methods, Embryo, Mammalian metabolism, Embryonic Development genetics, Morphogenesis genetics, Organogenesis genetics
- Abstract
A well-established experimental paradigm to analyze gene function in development is to elucidate the impact of gain and loss of gene activity on cell differentiation, tissue modelling, organogenesis, and morphogenesis. This chapter describes the experimental protocols to study gene function by means of electroporation and lipofection to manipulate genetic activity in whole embryos and fetal organs in vitro. These techniques allow for more precise control of the timing, with reference to developmental age or stage, and the cell/tissue-specificity of the changes in gene activity. They provide an alternative strategy that can expedite the analysis of gene function before resorting to the conventional means of transgenesis and gene targeting in the whole organism.
- Published
- 2014
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30. Deposition of (236)U from atmospheric nuclear testing in Washington state (USA) and the Pechora region (Russian Arctic).
- Author
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Ketterer ME, Groves AD, Strick BJ, Asplund CS, and Jones VJ
- Subjects
- Radiation Monitoring methods, Washington, Water Pollutants, Radioactive, Plutonium analysis, Soil Pollutants, Radioactive analysis, Uranium analysis
- Abstract
Stratospheric fallout-derived (236)U has been detected by sector field ICPMS at two field locations for which our laboratory possessed available archived samples: A) four soil cores from Washington state (northwestern USA) and B) sediment cores from three small lakes in the Pechora region (Russian Arctic). Four Washington state soil cores exhibit (236)U inventories of 8.1 ± 1.3, 11.1 ± 0.9, 18 ± 2, and 30.2 ± 3.9 Tatoms/m(2); the respective (239)Pu contents are 52.9 ± 3.5, 67 ± 3, 71 ± 2, and 151 ± 2 Tatoms/m(2). A (236)U/(239)Pu atom ratio of 0.19 ± 0.04 (1 SD) has been determined from the Washington state soil cores. The three Pechora region lake cores each exhibit coincident maxima in their (236)U and (239)Pu atom concentration profiles. The (236)U/(238)U atom ratios are controlled by two independent factors; (236)U is from fallout deposition and (238)U concentrations are a property of the geochemical distribution of naturally occurring U. A (236)U/(238)U atom ratio as high as 8.9 × 10(-6) has been observed for acid-leached soils containing Pu solely derived from bomb-test fallout. Accordingly, a non-zero (236)U background from stratospheric fallout must be recognized and taken into account when detectable (236)U is used to infer specific local or regional influences of reactor-irradiated U., (Copyright © 2012. Published by Elsevier Ltd.)
- Published
- 2013
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31. The mesenchymal architecture of the cranial mesoderm of mouse embryos is disrupted by the loss of Twist1 function.
- Author
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Bildsoe H, Loebel DA, Jones VJ, Hor AC, Braithwaite AW, Chen YT, Behringer RR, and Tam PP
- Subjects
- Animals, Apoptosis genetics, Basic Helix-Loop-Helix Transcription Factors genetics, Basic Helix-Loop-Helix Transcription Factors metabolism, Craniofacial Abnormalities genetics, Craniofacial Abnormalities metabolism, Craniofacial Abnormalities pathology, Embryo, Mammalian embryology, Fluorescent Antibody Technique, Gene Expression Regulation, Developmental, In Situ Hybridization, Mesoderm embryology, Mice, Mice, Inbred C57BL, Mice, Knockout, Mice, Transgenic, Models, Anatomic, Models, Genetic, Neural Crest cytology, Neural Crest embryology, Neural Crest metabolism, Nuclear Proteins deficiency, Reverse Transcriptase Polymerase Chain Reaction, Skull embryology, Skull metabolism, Time Factors, Twist-Related Protein 1 deficiency, Embryo, Mammalian metabolism, Mesoderm metabolism, Nuclear Proteins genetics, Twist-Related Protein 1 genetics
- Abstract
The basic helix-loop-helix transcription factor Twist1 is a key regulator of craniofacial development. Twist1-null mouse embryos exhibit failure of cephalic neural tube closure and abnormal head development and die at E11.0. To dissect the function of Twist1 in the cranial mesoderm beyond mid-gestation, we used Mesp1-Cre to delete Twist1 in the anterior mesoderm, which includes the progenitors of the cranial mesoderm. Deletion of Twist1 in mesoderm cells resulted in loss and malformations of the cranial mesoderm-derived skeleton. Loss of Twist1 in the mesoderm also resulted in a failure to fully segregate the mesoderm and the neural crest cells, and the malformation of some cranial neural crest-derived tissues. The development of extraocular muscles was compromised whereas the differentiation of branchial arch muscles was not affected, indicating a differential requirement for Twist1 in these two types of craniofacial muscle. A striking effect of the loss of Twist1 was the inability of the mesodermal cells to maintain their mesenchymal characteristics, and the acquisition of an epithelial-like morphology. Our findings point to a role of Twist1 in maintaining the mesenchyme architecture and the progenitor state of the mesoderm, as well as mediating mesoderm-neural crest interactions in craniofacial development., (Copyright © 2012 Elsevier Inc. All rights reserved.)
- Published
- 2013
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32. Diabetes in older adults.
- Author
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Kirkman MS, Briscoe VJ, Clark N, Florez H, Haas LB, Halter JB, Huang ES, Korytkowski MT, Munshi MN, Odegard PS, Pratley RE, and Swift CS
- Subjects
- Diabetes Mellitus drug therapy, Diabetes Mellitus metabolism, Diabetes Mellitus prevention & control, Diabetes Mellitus, Type 2 drug therapy, Diabetes Mellitus, Type 2 epidemiology, Diabetes Mellitus, Type 2 metabolism, Diabetes Mellitus, Type 2 prevention & control, Female, Humans, Prediabetic State drug therapy, Prediabetic State epidemiology, Prediabetic State metabolism, Prediabetic State prevention & control, Diabetes Mellitus epidemiology
- Published
- 2012
- Full Text
- View/download PDF
33. Diabetes in older adults: a consensus report.
- Author
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Kirkman MS, Briscoe VJ, Clark N, Florez H, Haas LB, Halter JB, Huang ES, Korytkowski MT, Munshi MN, Odegard PS, Pratley RE, and Swift CS
- Subjects
- Aged, Diabetes Complications diagnosis, Diabetes Complications prevention & control, Diabetes Complications therapy, Diabetes Mellitus diagnosis, Humans, Hypoglycemic Agents therapeutic use, Diabetes Mellitus therapy
- Published
- 2012
- Full Text
- View/download PDF
34. Long-range transport of pollutants to the Falkland Islands and Antarctica: evidence from lake sediment fly ash particle records.
- Author
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Rose NL, Jones VJ, Noon PE, Hodgson DA, Flower RJ, and Appleby PG
- Subjects
- Antarctic Regions, Environmental Monitoring, Falkland Islands, History, 19th Century, History, 20th Century, History, 21st Century, Lead Radioisotopes analysis, Lead Radioisotopes history, Coal Ash analysis, Coal Ash history, Environmental Pollutants analysis, Environmental Pollutants history, Geologic Sediments analysis, Lakes analysis
- Abstract
(210)Pb-dated sediment cores taken from lakes on the Falkland Islands, the South Orkney Islands, and the Larsemann Hills in Antarctica were analyzed for fly ash particles to assess the temporal record of contamination from high temperature fossil-fuel combustion sources. Very low, but detectable, levels were observed in the Antarctic lakes. In the Falkland Island lakes, the record of fly ash extended back to the late-19th century and the scale of contamination was considerably higher. These data, in combination with meteorological, modeling, and fossil-fuel consumption data, indicate most likely sources are in South America, probably Chile and Brazil. Other southern hemisphere sources, notably from Australia, contribute to a background contamination and were more important historically. Comparing southern polar data with the equivalent from the northern hemisphere emphasizes the difference in contamination of the two circumpolar regions, with the Falkland Island sites only having a level of contamination similar to that of northern Svalbard.
- Published
- 2012
- Full Text
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35. Stereotype threat undermines academic learning.
- Author
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Taylor VJ and Walton GM
- Subjects
- Black or African American, Female, Humans, Male, Semantics, United States, White People, Educational Status, Prejudice
- Abstract
Two experiments tested whether stereotype threat can undermine the acquisition of academic knowledge and thus harm performance even in nonthreatening settings. In Experiment 1, Black and White students studied rare words in either nonthreatening or threatening conditions. One to two weeks later, participants recalled word definitions, half in a nonthreatening "warm-up" and half in a threatening "test." Replicating past research, Black students performed worse on the test than on the warm-up. But importantly, Black students who had studied in the threatening rather than nonthreatening environment performed worse even on the warm-up. White students were unaffected. In Experiment 2, a value affirmation eliminated the learning-threat effect and provided evidence of psychological process. The results suggest that stereotype threat causes a form of "double jeopardy" whereby threat can undermine both learning and performance. The discussion addresses implications for the interpretation of group differences and for understanding how brief threat-reducing interventions can produce long-lasting benefits.
- Published
- 2011
- Full Text
- View/download PDF
36. Sox17-dependent gene expression and early heart and gut development in Sox17-deficient mouse embryos.
- Author
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Pfister S, Jones VJ, Power M, Truisi GL, Khoo PL, Steiner KA, Kanai-Azuma M, Kanai Y, Tam PP, and Loebel DA
- Subjects
- Animals, Cell Transplantation methods, Embryo, Mammalian cytology, Embryo, Mammalian embryology, Endoderm embryology, Endoderm metabolism, Female, Gastrointestinal Tract embryology, Gene Expression Profiling, Green Fluorescent Proteins genetics, Green Fluorescent Proteins metabolism, HMGB Proteins deficiency, Heart embryology, Hep G2 Cells, Humans, In Situ Hybridization, Male, Mice, Mice, 129 Strain, Mice, Knockout, Mice, Transgenic, Oligonucleotide Array Sequence Analysis, Reverse Transcriptase Polymerase Chain Reaction, SOXF Transcription Factors deficiency, Somites embryology, Somites metabolism, Embryo, Mammalian metabolism, Gastrointestinal Tract metabolism, Gene Expression Regulation, Developmental, HMGB Proteins genetics, Myocardium metabolism, SOXF Transcription Factors genetics
- Abstract
Sox17 is a transcription factor that is required for maintenance of the definitive endoderm in mouse embryos. By expression profiling of wild-type and mutant embryos and Sox17-overexpressing hepatoma cells, we identified genes with Sox17-dependent expression. Among the genes that were up-regulated in Sox17-null embryos and down-regulated by Sox17 expressing HepG2 cells is a set of genes that are expressed in the developing liver, suggesting that one function of Sox17 is the repression of liver gene expression, which is compatible with a role for Sox17 in maintaining the definitive endoderm in a progenitor state. Consistent with these findings, Sox17(-/-) cells display a diminished capacity to contribute to the definitive endoderm when transplanted into wild-type hosts. Analysis of gene ontology further revealed that many genes related to heart development were downregulated in Sox17-null embryos. This is associated with the defective development of the heart in the mutant embryos, which is accompanied by localised loss of Myocd-expressing cardiogenic progenitors and the malformation of the anterior intestinal portal.
- Published
- 2011
- Full Text
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37. Alternans in genetically modified langendorff-perfused murine hearts modeling catecholaminergic polymorphic ventricular tachycardia.
- Author
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Sabir IN, Ma N, Jones VJ, Goddard CA, Zhang Y, Kalin A, Grace AA, and Huang CL
- Abstract
The relationship between alternans and arrhythmogenicity was studied in genetically modified murine hearts modeling catecholaminergic polymorphic ventricular tachycardia (CPVT) during Langendorff perfusion, before and after treatment with catecholamines and a β-adrenergic antagonist. Heterozygous (RyR2(p/s)) and homozygous (RyR2(s/s)) RyR2-P2328S hearts, and wild-type (WT) controls, were studied before and after treatment with epinephrine (100 nM and 1 μM) and propranolol (100 nM). Monophasic action potential recordings demonstrated significantly greater incidences of arrhythmia in RyR2(p/s) and RyR2(s/s) hearts as compared to WTs. Arrhythmogenicity in RyR2(s/s) hearts was associated with alternans, particularly at short baseline cycle lengths. Both phenomena were significantly accentuated by treatment with epinephrine and significantly diminished by treatment with propranolol, in full agreement with clinical expectations. These changes took place, however, despite an absence of changes in mean action potential durations, ventricular effective refractory periods or restitution curve characteristics. Furthermore pooled data from all hearts in which arrhythmia occurred demonstrated significantly greater alternans magnitudes, but similar restitution curve slopes, to hearts that did not demonstrate arrhythmia. These findings thus further validate the RyR2-P2328S murine heart as a model for human CPVT, confirming an alternans phenotype in common with murine genetic models of the Brugada syndrome and the congenital long-QT syndrome type 3. In contrast to these latter similarities, however, this report demonstrates the dissociation of alternans from changes in the properties of restitution curves for the first time in a murine model of a human arrhythmic syndrome.
- Published
- 2010
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38. Cardiac arrhythmia: a simple conceptual framework.
- Author
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Kalin A, Usher-Smith J, Jones VJ, Huang CL, and Sabir IN
- Subjects
- Action Potentials, Animals, Arrhythmias, Cardiac physiopathology, Humans, Risk Factors, Time Factors, Arrhythmias, Cardiac etiology, Heart Conduction System physiopathology
- Abstract
This review presents a simple trigger-substrate model of arrhythmogenesis and its application to the generation of reentrant ventricular arrhythmias. We demonstrate its broad applicability to the understanding of arrhythmic phenomena in a wide range of both hereditary and acquired arrhythmic disorders., (Copyright © 2010 Elsevier Inc. All rights reserved.)
- Published
- 2010
- Full Text
- View/download PDF
39. Requirement for Twist1 in frontonasal and skull vault development in the mouse embryo.
- Author
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Bildsoe H, Loebel DA, Jones VJ, Chen YT, Behringer RR, and Tam PP
- Subjects
- Animals, Branchial Region cytology, Branchial Region embryology, Branchial Region physiology, Frontal Bone embryology, Frontal Bone metabolism, Jaw embryology, Jaw metabolism, Mice, Mice, Mutant Strains, Nasal Bone embryology, Nasal Bone metabolism, Neural Crest cytology, Neural Crest physiology, Skull cytology, Skull physiology, Morphogenesis physiology, Neural Crest embryology, Nuclear Proteins physiology, Skull embryology, Twist-Related Protein 1 physiology
- Abstract
Using a Cre-mediated conditional deletion approach, we have dissected the function of Twist1 in the morphogenesis of the craniofacial skeleton. Loss of Twist1 in neural crest cells and their derivatives impairs skeletogenic differentiation and leads to the loss of bones of the snout, upper face and skull vault. While no anatomically recognizable maxilla is formed, a malformed mandible is present. Since Twist1 is expressed in the tissues of the maxillary eminence and the mandibular arch, this finding suggests that the requirement for Twist1 is not the same in all neural crest derivatives. The effect of the loss of Twist1 function is not restricted to neural crest-derived bones, since the predominantly mesoderm-derived parietal and interparietal bones are also affected, presumably as a consequence of lost interactions with neural crest-derived tissues. In contrast, the formation of other mesodermal skeletal derivatives such as the occipital bones and most of the chondrocranium are not affected by the loss of Twist1 in the neural crest cells.
- Published
- 2009
- Full Text
- View/download PDF
40. BMP/SMAD1 signaling sets a threshold for the left/right pathway in lateral plate mesoderm and limits availability of SMAD4.
- Author
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Furtado MB, Solloway MJ, Jones VJ, Costa MW, Biben C, Wolstein O, Preis JI, Sparrow DB, Saga Y, Dunwoodie SL, Robertson EJ, Tam PP, and Harvey RP
- Subjects
- Animals, Cell Line, Forkhead Transcription Factors metabolism, Humans, Mesoderm embryology, Mice, Mutation, Nodal Protein metabolism, Signal Transduction, Smad1 Protein genetics, Smad4 Protein genetics, Body Patterning, Bone Morphogenetic Proteins metabolism, Mesoderm physiology, Smad1 Protein metabolism, Smad4 Protein metabolism
- Abstract
Bistability in developmental pathways refers to the generation of binary outputs from graded or noisy inputs. Signaling thresholds are critical for bistability. Specification of the left/right (LR) axis in vertebrate embryos involves bistable expression of transforming growth factor beta (TGFbeta) member NODAL in the left lateral plate mesoderm (LPM) controlled by feed-forward and feedback loops. Here we provide evidence that bone morphogenetic protein (BMP)/SMAD1 signaling sets a repressive threshold in the LPM essential for the integrity of LR signaling. Conditional deletion of Smad1 in the LPM led to precocious and bilateral pathway activation. NODAL expression from both the left and right sides of the node contributed to bilateral activation, indicating sensitivity of mutant LPM to noisy input from the LR system. In vitro, BMP signaling inhibited NODAL pathway activation and formation of its downstream SMAD2/4-FOXH1 transcriptional complex. Activity was restored by overexpression of SMAD4 and in embryos, elevated SMAD4 in the right LPM robustly activated LR gene expression, an effect reversed by superactivated BMP signaling. We conclude that BMP/SMAD1 signaling sets a bilateral, repressive threshold for NODAL-dependent Nodal activation in LPM, limiting availability of SMAD4. This repressive threshold is essential for bistable output of the LR system.
- Published
- 2008
- Full Text
- View/download PDF
41. Criteria for arrhythmogenicity in genetically-modified Langendorff-perfused murine hearts modelling the congenital long QT syndrome type 3 and the Brugada syndrome.
- Author
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Sabir IN, Li LM, Jones VJ, Goddard CA, Grace AA, and Huang CL
- Subjects
- Action Potentials, Animals, Brugada Syndrome genetics, Brugada Syndrome physiopathology, Brugada Syndrome prevention & control, Cardiac Pacing, Artificial, Disease Models, Animal, Electrocardiography, Endocardium drug effects, Endocardium physiopathology, Long QT Syndrome genetics, Long QT Syndrome physiopathology, Long QT Syndrome prevention & control, Mice, Mice, Transgenic, Models, Cardiovascular, NAV1.5 Voltage-Gated Sodium Channel, Perfusion, Pericardium drug effects, Pericardium physiopathology, Sodium Channels genetics, Time Factors, Anti-Arrhythmia Agents toxicity, Brugada Syndrome chemically induced, Flecainide toxicity, Heart Rate drug effects, Long QT Syndrome chemically induced, Quinidine toxicity, Sodium Channels metabolism
- Abstract
The experiments investigated the applicability of two established criteria for arrhythmogenicity in Scn5a+/Delta and Scn5a+/- murine hearts modelling the congenital long QT syndrome type 3 (LQT3) and the Brugada syndrome (BrS). Monophasic action potentials (APs) recorded during extrasystolic stimulation procedures from Langendorff-perfused control hearts and hearts treated with flecainide (1 microM) or quinidine (1 or 10 microM) demonstrated that both agents were pro-arrhythmic in wild-type (WT) hearts, quinidine was pro-arrhythmic in Scn5a+/Delta hearts, and that flecainide was pro-arrhythmic whereas quinidine was anti-arrhythmic in Scn5a+/- hearts, confirming clinical findings. Statistical analysis confirmed a quadratic relationship between epicardial and endocardial AP durations (APDs) in WT control hearts. However, comparisons between plots of epicardial against endocardial APDs and this reference curve failed to correlate with arrhythmogenicity. Restitution curves, relating APD to diastolic interval (DI), were then constructed for the first time in a murine system and mono-exponential growth functions fitted to these curves. Significant (P<0.05) alterations in the DI at which slopes equalled unity, an established indicator of arrhythmogenicity, now successfully predicted the presence or absence of arrhythmogenicity in all cases. We thus associate changes in the slopes of restitution curves with arrhythmogenicity in models of LQT3 and BrS.
- Published
- 2008
- Full Text
- View/download PDF
42. Type 1 diabetes: exercise and hypoglycemia.
- Author
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Briscoe VJ, Tate DB, and Davis SN
- Subjects
- Female, Glucose administration & dosage, Glucose metabolism, Humans, Insulin administration & dosage, Insulin adverse effects, Male, Sex Characteristics, Diabetes Mellitus, Type 1 physiopathology, Diabetes Mellitus, Type 1 therapy, Exercise physiology, Hypoglycemia etiology
- Abstract
The Diabetes Control and Complications Trial demonstrated that tight control of diabetes management greatly reduces the risk of microvascular complications of diabetes. Unfortunately, tight control of blood glucose can also result in hypoglycemia, especially in patients with type 1 diabetes mellitus (T1DM). It is now widely recognized that antecedent hypoglycemia can blunt neuroendocrine, autonomic nervous system (ANS), and metabolic counterregulatory responses to subsequent hypoglycemia. Thus, blunted counterregulatory defenses against falling plasma glucose levels are a major risk factor for hypoglycemia in people with diabetes. This risk is also complicated by a difference in responses between males and females. Because of the qualitative similarity of neuroendocrine, ANS, and metabolic responses to hypoglycemia and exercise, we developed studies to determine whether neuroendocrine and ANS counterregulatory dysfunction play a role in the pathogenesis of exercise-related hypoglycemia in T1DM. Results from these studies have shown that neuroendocrine (catecholamine and glucagon), ANS (muscle sympathetic nerve activity), and metabolic (lipolysis and glucose kinetics) responses are blunted during exercise after antecedent hypoglycemia, and that there is a sexual dimorphism in responses. Similarly, antecedent episodes of exercise can blunt counterregulatory responses during subsequent hypoglycemia, thereby creating reciprocal feed-forward vicious cycles that increase the risk of hypoglycemia during either stress.
- Published
- 2007
- Full Text
- View/download PDF
43. The use of gauze: will it ever change?
- Author
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Jones VJ
- Subjects
- Bandages trends, Humans, Wound Healing, Occlusive Dressings trends
- Abstract
Although the benefits of healing in a moist environment have been published worldwide, the use of woven gauze as a wound contact material still prevails in many countries. This article traces the history of gauze and problems associated with usage against the introduction of one of the first modern materials, the hydrocolloid. Why this revolution in dressing material did not herald an immediate change of practice away from gauze is examined. Since the 1970s, the range, availability and sophistication of these and other moisture-retentive dressings have increased dramatically, and yet it seems that some practitioners remain unconvinced. The processes that underpin personal and organisational change that may contribute to this reluctance are also considered.
- Published
- 2006
- Full Text
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44. Climate-driven regime shifts in the biological communities of arctic lakes.
- Author
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Smol JP, Wolfe AP, Birks HJ, Douglas MS, Jones VJ, Korhola A, Pienitz R, Rühland K, Sorvari S, Antoniades D, Brooks SJ, Fallu MA, Hughes M, Keatley BE, Laing TE, Michelutti N, Nazarova L, Nyman M, Paterson AM, Perren B, Quinlan R, Rautio M, Saulnier-Talbot E, Siitonen S, Solovieva N, and Weckström J
- Subjects
- Animals, Arctic Regions, Biodiversity, Eukaryota isolation & purification, Fresh Water, Invertebrates, Time Factors, Water Microbiology, Cold Climate, Ecosystem, Greenhouse Effect
- Abstract
Fifty-five paleolimnological records from lakes in the circumpolar Arctic reveal widespread species changes and ecological reorganizations in algae and invertebrate communities since approximately anno Domini 1850. The remoteness of these sites, coupled with the ecological characteristics of taxa involved, indicate that changes are primarily driven by climate warming through lengthening of the summer growing season and related limnological changes. The widespread distribution and similar character of these changes indicate that the opportunity to study arctic ecosystems unaffected by human influences may have disappeared.
- Published
- 2005
- Full Text
- View/download PDF
45. Rapid dating of recent sediments in Loch Ness: inductively coupled plasma mass spectrometric measurements of global fallout plutonium.
- Author
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Ketterer ME, Hafer KM, Jones VJ, and Appleby PG
- Abstract
The (239+240)Pu activity profile is determined for a sediment core collected from 170-m depth at Loch Ness, Scotland. These measurements use magnetic sector inductively coupled plasma mass spectrometry for rapid determination of Pu activities and (240)Pu/(239)Pu atom ratios. A (239+240)Pu detection limit of 0.1 Bq/kg is obtained for 2 g of acid-leached sediment; (242)Pu is used as a spike isotope. The Pu activity profile exhibits a maximum of 42.7+/-0.3 Bq/kg (239+240)Pu in the 9-10-cm depth interval. The position of this maximum coincides with peaks in the (241)Am and (137)Cs activity profiles. These peak activities are ascribed to the 1963/1964 peak fallout from atmospheric testing of nuclear weapons. The (240)Pu/(239)Pu atom ratios are in the range 0.15-0.20, in agreement with the expected range of 0.166-0.194 for Northern Hemisphere fallout, and do not suggest the presence of other contributing sources. This study demonstrates that ICPMS has considerable potential for rapid determination of the chronology of post-1950 sediments, and also for validating (210)Pb dates where chronologies over longer time-scales are needed.
- Published
- 2004
- Full Text
- View/download PDF
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