277 results on '"Newell, Mark A."'
Search Results
252. Physical and electronic structure of simple metal systems studied by electron spectroscopy
- Author
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Newell, Mark Alistair
- Subjects
- 530.41, Solid-state physics
- Published
- 1992
253. The historic working small craft of South Carolina : a general typology with a study of adaptations of flatboat design
- Author
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Newell, Mark M.
- Subjects
- 623.8, VM275.C2N3 ; Flatboats--United States--South Carolina
- Abstract
The following dissertation presents a typology for historic working watercraft of the State of South Carolina, United States of America. The background investigation for this typology addressed research design questions concerning the geographic and ethnic origins of the builders of these craft, the history of transportation growth in the area and other factors which are thought to have influenced basic design, and construction methods. These factors were the environments in which craft operated, the materials and skills available for their construction, and the shapes and eights of typical cargoes they were designed to transport. In addition to archival sources, data was developed by surveying regions of South Carolina where specific types of craft were known to operate. These areas included lower coastal plain riverine environments, abandoned rice plantations, abandoned ferry crossings, historic canals, and marine phosphate mining areas. Where remains of craft were discovered, a survey was conducted to gather sufficient information to determine the basic design, construction, and function of the vessel. Experimental archaeological projects also were undertaken during the last stages of the research to determine if it were possible to gather viable data concerning construction economy, construction sequence, and performance. The projects consisted of the construction of one full scale 'replica' rice plantation barge, one full scale 'reconstruction' of an upland cotton boat, and one large scale model of a plantation chine-girder barge. These projects also constituted an examination of the value of experimental archaeology to this type of research. The work also provided an opportunity to compare the relative values of the construction of replicas using historic techniques and materials, versus 'reconstruction' to visually accurate standards using modern materials. It was determined, given certain factors dictated by funding and labor, that experimental archaeology can indeed contribute worthwhile data for research purposes. The archival and field data generated by this activity were analyzed and a typology developed. It was determined that at least fourteen specific types of paddled or wind and tide driven watercraft were operated in the study area from the pre-historic period to approximately 1930. These craft included dugout canoes, dugout-form based plantation craft, flat bottomed sailing vessels, round hulled ocean going sailing vessels, barge-form ferry craft, rice flats and phosphate carriers, extreme length-to-beam ratio mountain river craft, and highly specialized canal craft. The data also indicate that working environments and cargo form were specific and direct influences on watercraft design. In some cases, such as aboriginal dugout canoes produced prior to European contact, ethnic influences were readily discernible. This proved not to be the case after the contact period. Archival data clearly indicate that both European and Africans and African Americans were engaged in watercraft construction and operation during the study period. Evidence is presented to show that Europeans sought specific skills among imported Africans ranging from the cultivation of agricultural crops to blacksmithing. Further evidence demonstrates African skills in watercraft construction and operation, especially of dugout canoes and dugout based designs. It is hypothesized that craft of these type are most likely to be representative of the craft produced by this ethnic group in South Carolina. This hypothesis is supported by presentation of archival data showing that these types of craft were the vessels of choice of African and African American crews. Further evidence is presented to show that widely ranging European boat building skills also are represented in the archaeological record, including English, French and possibly middle European influences. It is further determined that specific identification of the influence of anyone ethnic group is made unlikely as a result of the early absorption of ethnic traditions and the training of one group, Africans and African Americans, in the boat-building and carpentry traditions of the dominant European group. Extensive additional field data is presented on barge-form craft as remains of this type of vessel contributed to the archaeological record in far greater numbers than any other. The preponderance of this form is interpreted as a manifestation of the magnitude of the South Carolina rice industry and the catastrophic nature of its cessation due to the Civil War of 1860-1865. Two types of construction are identified, one based on plank and frame (as opposed to plank on frame) methods, the other method utilizing massive chine-girder logs. Evidence is presented to demonstrate that, while the basic barge or flat design was similar throughout the study area, details of construction including chine-girder shaping, fastening methods, scarphing techniques, and bow/stern to side construction methods varied greatly. This is interpreted as a reflection of the individual skills of the plantation carpenters who were primarily responsible for the building of these craft. Evidence also is presented for an emerging dating technique based on the nature of construction methods, types of fastenings, and the size of lumber components of barge form craft. The research also suggests predictive models for determining the likelihood of further remains of specific vessel types ranging from rice cuIture flats to phosphate barges. Finally, appendices to this dissertation include 106 illustrations, a glossary of terms, a procedure for barge documentation, tables of conversions for metric measurements to English measurement on barges, and a discussion of weights and measurements for historic period cargoes and containers.
- Published
- 1997
254. Quiet is the new loud.
- Author
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Newell, Mark
- Subjects
- *
LETTERS to the editor , *SILENT films - Abstract
A letter to the editor is presented in response to the article by Tim Young on tax funding for silent film screenings in the October 2009 issue.
- Published
- 2009
255. Unwelcome intrusions.
- Author
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Newell, Mark
- Subjects
- *
LETTERS to the editor , *SILENT film music - Abstract
A letter to the editor is presented in response to the article in the September 2009 issue by Keith Whithall about sound accompaniments to silent films.
- Published
- 2009
256. Letters.
- Author
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Shabshis, Adele, Wilkinson, Jim, Newell, Mark, and McBride, Amanda
- Abstract
Several letters to the editor are presented in response to articles in previous issues, including "Aged care outrage," and "GP workforce greying fast," in the January 30, 2009 issue, "Natural fertility regulation---the Billing Ovulation Method," in the December 19, 2008 issue.
- Published
- 2009
257. Letters.
- Author
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Hobbs, Tony, Berry, Ashley, Seidler, Raymond, Newell, Mark, George, Kate, and Bhaskar, Pushpa
- Abstract
Several letters to the editor are presented in response to the articles in previous issues including "Divisions nothing but a waste', Gut Feelings" in the March 7, 2008 issue, "In this debate, patients' health outcomes are real bottom line" in the March 7, 2008 issue and "Let's end suspicion of sleaze" in the March 7, 2008 issue.
- Published
- 2008
258. Earlier and more frequent occupation of breeding sites during the non‐breeding season increases breeding success in a colonial seabird.
- Author
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Bennett, Sophie, Harris, Mike P., Wanless, Sarah, Green, Jonathan A., Newell, Mark A., Searle, Kate R., and Daunt, Francis
- Subjects
- *
COLONIAL birds , *ANIMAL breeding , *COLONIES (Biology) , *CHRONOPHOTOGRAPHY , *PATH analysis (Statistics) - Abstract
Competition for high‐quality breeding sites in colonial species is often intense, such that individuals may invest considerable time in site occupancy even outside the breeding season. The site defense hypothesis predicts that high‐quality sites will be occupied earlier and more frequently, consequently those sites will benefit from earlier and more successful breeding. However, few studies relate non‐breeding season occupancy to subsequent breeding performance limiting our understanding of the potential life‐history benefits of this behavior. Here, we test how site occupancy in the non‐breeding season related to site quality, breeding timing, and breeding success in a population of common guillemots Uria aalge, an abundant and well‐studied colonially breeding seabird. Using time‐lapse photography, we recorded occupancy at breeding sites from October to March over three consecutive non‐breeding seasons. We then monitored the successive breeding timing (lay date) and breeding success at each site. On average, sites were first occupied on the 27th October ± 11.7 days (mean ± SD), subsequently occupied on 46 ± 18% of survey days and for 55 ± 15% of the time when at least one site was occupied. Higher‐quality sites, sites with higher average historic breeding success, were occupied earlier, more frequently and for longer daily durations thereafter. Laying was earlier at sites that were occupied more frequently and sites occupied earlier were more successful, supporting the site defense hypothesis. A path analysis showed that the return date had a greater or equal effect on breeding success as lay date. Pair level occupancy had no effect on breeding timing or success. The clear effect of non‐breeding occupancy of breeding sites on breeding timing and success highlights the benefits of this behavior on demography in this population and the importance of access to breeding sites outside the breeding season in systems where competition for high‐quality sites is intense. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
259. Modelling the responses of partially migratory metapopulations to changing seasonal migration rates: From theory to data.
- Author
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Payo‐Payo, Ana, Acker, Paul, Bocedi, Greta, Travis, Justin M. J., Burthe, Sarah J., Harris, Michael P., Wanless, Sarah, Newell, Mark, Daunt, Francis, and Reid, Jane M.
- Subjects
- *
VITAL statistics , *MIGRATORY animals , *CONCEPTUAL models , *DYNAMIC models , *POPULATION dynamics - Abstract
Among‐individual and within‐individual variation in expression of seasonal migration versus residence is widespread in nature and could substantially affect the dynamics of partially migratory metapopulations inhabiting seasonally and spatially structured environments. However, such variation has rarely been explicitly incorporated into metapopulation dynamic models for partially migratory systems. We, therefore, lack general frameworks that can identify how variable seasonal movements, and associated season‐ and location‐specific vital rates, can control system persistence.We constructed a novel conceptual framework that captures full‐annual‐cycle dynamics and key dimensions of metapopulation structure for partially migratory species inhabiting seasonal environments. We conceptualize among‐individual variation in seasonal migration as two variable vital rates: seasonal movement probability and associated movement survival probability. We conceptualize three levels of within‐individual variation (i.e. plasticity), representing seasonal or annual variation in seasonal migration or lifelong fixed strategies. We formulate these concepts as a general matrix model, which is customizable for diverse life‐histories and seasonal landscapes.To illustrate how variable seasonal migration can affect metapopulation growth rate, demographic structure and vital rate elasticities, we parameterize our general models for hypothetical short‐ and longer‐lived species. Analyses illustrate that elasticities of seasonal movement probability and associated survival probability can sometimes equal or exceed those of vital rates typically understood to substantially influence metapopulation dynamics (i.e. seasonal survival probability or fecundity), that elasticities can vary non‐linearly, and that metapopulation outcomes depend on the level of within‐individual plasticity.We illustrate how our general framework can be applied to evaluate the consequences of variable and changing seasonal movement probability by parameterizing our models for a real partially migratory metapopulation of European shags Gulosus aristotelis assuming lifelong fixed strategies. Given observed conditions, metapopulation growth rate was most elastic to breeding season adult survival of the resident fraction in the dominant population. However, given doubled seasonal movement probability, variation in survival during movement would become the primary driver of metapopulation dynamics.Our general conceptual and matrix model frameworks, and illustrative analyses, thereby highlight complex ways in which structured variation in seasonal migration can influence dynamics of partially migratory metapopulations, and pave the way for diverse future theoretical and empirical advances. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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260. Permissive Hypotension: Potentially Harmful in the Elderly? A National Trauma Data Bank Analysis.
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WAIBEL, BRETT H., BRIDGES, LINDSAY C., and NEWELL, MARK A.
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- *
HYPOTENSION , *BLOOD circulation disorders , *DATABASES , *DISEASES in older people , *RESUSCITATION - Abstract
Permissive hypotension is a component of damage control resuscitation that aims to provide a directed, controlled resuscitation, while countering the "lethal triad." This principle has not been specifically studied in elderly (ELD) trauma patients (S55 years). Given the ELD population's lack of physiologic reserve and risk of inadequate perfusion with "normal" blood pressures, we hypothesized that utilized a permissive hypotension strategy in ELD trauma patients would result in worse outcomes compared with younger patients (18-54 years). A retrospective review of National Trauma Data Bank reports from 2009 and 2010, identifying critically ill patients undergoing a "damage control laparotomy," was performed to determine the effect of age and systolic blood pressure on outcome. Logistic regression analysis, including evaluation of an interaction between age and admission blood pressure, was performed on mortality using admission demographics, physiology, injury severity, mechanism of injury, and in-hospital complications. Although there was a higher likelihood of death with greater age, lower admission systolic blood pressure, lower Glasgow Coma Score, increased injury severity score, and acute renal failure, a synergistic effect of age and blood pressure on mortality was not identified. Permissive hypotension appears to be a possible management strategy in ELD trauma patients. [ABSTRACT FROM AUTHOR]
- Published
- 2015
261. Modelling and mapping how common guillemots balance their energy budgets over a full annual cycle.
- Author
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Dunn, Ruth E., Green, Jonathan A., Wanless, Sarah, Harris, Mike P., Newell, Mark A., Bogdanova, Maria I., Horswill, Catharine, Daunt, Francis, and Matthiopoulos, Jason
- Subjects
- *
OCEAN temperature , *CALORIC expenditure , *ANIMAL populations , *SEVERE storms , *ENERGY budget (Geophysics) , *REPRODUCTION , *POPULATION dynamics , *BAYESIAN analysis - Abstract
The ability of individual animals to balance their energy budgets throughout the annual cycle is important for their survival, reproduction and population dynamics. However, the annual cycles of many wild, mobile animals are difficult to observe and our understanding of how individuals balance their energy budgets throughout the year therefore remains poor.We developed a hierarchical Bayesian state‐space model to investigate how key components of animal energy budgets (namely individual energy gain and storage) varied in space and time. Our model used biologger‐derived estimates of time‐activity budgets, locations and energy expenditure to infer year‐round time series of energy income and reserves. The model accounted for seasonality in environmental drivers such as sea surface temperature and daylength, allowing us to identify times and locations of high energy gain.Our study system was a population of common guillemots Uria aalge breeding at a western North Sea colony. These seabirds manage their energy budgets by adjusting their behaviour and accumulating fat reserves. However, typically during severe weather conditions, birds can experience an energy deficit over a sustained period, leading to starvation and large‐scale mortality events.We show that guillemot energy gain varied in both time and space. Estimates of guillemot body mass varied throughout the annual cycle and birds periodically experienced losses in mass. Mass losses were likely to have either been adaptive, or due to energetic bottlenecks, the latter leading to increased susceptibility to mortality. Guillemots tended to be lighter towards the edge of their spatial distribution.We describe a framework that combines biologging data, time‐activity budget analysis and Bayesian state‐space modelling to identify times and locations of high energetic reward or potential energetic bottlenecks in a wild animal population. Our approach can be extended to address ecological and conservation‐driven questions that were previously unanswerable due to logistical complexities in collecting data on wild, mobile animals across full annual cycles. Read the free Plain Language Summary for this article on the Journal blog. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
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262. Don't privatize job specialties.
- Author
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Newell, Mark
- Subjects
PRIVATIZATION - Abstract
Criticizes the article `Study finds too many general officers,' which appeared in the April 6 1998 edition of `Army Times.' Reaction to the article's statements regarding the privatization of some United States governmental agencies; Necessity of trained and qualified officers for military support roles; Contention on the article's failure to examine the effect of modernization on battlefield operations.
- Published
- 1998
263. Site‐dependent regulation of breeding success: Evidence for the buffer effect in the common guillemot, a colonially breeding seabird.
- Author
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Bennett, Sophie, Wanless, Sarah, Harris, Michael P., Newell, Mark A., Searle, Kate, Green, Jonathan A., and Daunt, Francis
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- *
DEMOGRAPHIC change , *SUCCESS - Abstract
Density‐dependent regulation can offer resilience to wild populations experiencing fluctuations in environmental conditions because, at lower population sizes, the average quality of habitats or resources is predicted to increase. Site‐dependent regulation is a mechanism whereby individuals breed at the highest quality, most successful, sites, leaving poorer quality, less successful sites vacant. As population size increases, higher quality sites become limiting but when populations decline, lower quality sites are vacated first, offering resilience. This process is known as the 'buffer effect'. However, few studies have tested whether such regulation operates in populations experiencing changes in size and trend.We used data from a population of common guillemots Uria aalge, a colonially breeding seabird, to investigate the relationship between site occupancy probability, site quality and population size and trend. These data were collected at five sub‐colonies spanning a 38‐year period (1981–2018) comprising phases of population increase, decrease and recovery.We first tested whether site quality and population size in sub‐colonies explained which sites were occupied for breeding, and if this was robust to changes in sub‐colony trend. We then investigated whether disproportionate use of higher quality sites drove average site quality and breeding success across sub‐colony sizes and trends. Finally, we tested whether individuals consistently occupied higher quality sites during periods of decline and recovery.Higher quality sites were disproportionality used when sub‐colony size was smaller, resulting in higher average site quality and breeding success at lower population sizes. This relationship was unaffected by changes in sub‐colony trend. However, contrary to the predictions of the buffer effect, new sites were established at a similar rate to historically occupied sites during sub‐colony decline and recovery despite being of lower quality.Our results provide support for the buffer effect conferring resilience to populations, such that average breeding success was consistently higher at lower population size during all phases of population change. However, this process was tempered by the continued establishment of new, lower quality, sites which could act to slow population recovery after periods when colony size was low. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
264. Impact of Hypothermia (below 36°C) in the Rural Trauma Patient
- Author
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Waibel, Brett H., Schlitzkus, Lisa L., Newell, Mark A., Durham, Christopher A., Sagraves, Scott G., and Rotondo, Michael F.
- Subjects
- *
HYPOTHERMIA , *WOUNDS & injuries , *RURAL health services , *INJURY complications , *MORTALITY , *LENGTH of stay in hospitals , *GLASGOW Coma Scale-Extended , *PATIENTS - Abstract
Background: Hypothermia is an independent predictor of mortality based on urban studies. But this association has not been described in the rural setting. This study''s purpose was to evaluate hypothermia as a cofactor to mortality, complications, and hospital length of stay (LOS) parameters in the rural trauma setting. Study Design: The National Trauma Registry of the American College of Surgeons database for our rural, Level I trauma center was queried for a 5-year period (July 2002 to June 2007) to identify adult trauma patients. Multivariate regression models were used to evaluate the association of hypothermia with mortality; infectious complications; organ dysfunction; and, among survivors, hospital LOS parameters. Results: Of 9,482 adult patients admitted, 1,490 (15.7%) patients were hypothermic. Hypothermia had an adjusted odds ratio of 1.70 for mortality (95% CI, 1.35 to 2.12; p < 0.001). After controlling for covariates, hypothermia was not significantly associated with infectious complications or organ dysfunction, except for arrhythmia (adjusted odds ratio, 1.40; CI, 1.03 to 1.90; p = 0.031). Hypothermia was not associated with a difference in ICU (p = 0.310) or ventilator (p = 0.144) LOS. But a slight increase in hospital days was noted in the hypothermic patient (hazards ratio, 0.890 for discharge; 95% CI, 0.838 to 0.946; p < 0.001). Conclusions: Hypothermia is a common problem at admission in a rural trauma center. It is associated with an increase in hospitalized days but not with increased ICU or ventilator days among survivors. Other than arrhythmias, it was not significantly associated with other National Trauma Registry of the American College of Surgeons infectious or organ dysfunction complications. Hypothermia is an independent risk factor for mortality in the rural trauma patient. [Copyright &y& Elsevier]
- Published
- 2009
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265. No evidence for fitness signatures consistent with increasing trophic mismatch over 30 years in a population of European shag Phalacrocorax aristotelis.
- Author
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Keogan, Katharine, Lewis, Sue, Howells, Richard J., Newell, Mark A., Harris, Michael P., Burthe, Sarah, Phillips, Richard A., Wanless, Sarah, Phillimore, Albert B., Daunt, Francis, and Teplitsky, Celine
- Subjects
- *
OCEAN temperature , *PLANT phenology , *FOOD chains - Abstract
As temperatures rise, timing of reproduction is changing at different rates across trophic levels, potentially resulting in asynchrony between consumers and their resources. The match–mismatch hypothesis (MMH) suggests that trophic asynchrony will have negative impacts on average productivity of consumers. It is also thought to lead to selection on timing of breeding, as the most asynchronous individuals will show the greatest reductions in fitness.Using a 30‐year individual‐level dataset of breeding phenology and success from a population of European shags on the Isle of May, Scotland, we tested a series of predictions consistent with the hypothesis that fitness impacts of trophic asynchrony are increasing.These predictions quantified changes in average annual breeding success and strength of selection on timing of breeding, over time and in relation to rising sea surface temperature (SST) and diet composition.Annual average (population) breeding success was negatively correlated with average lay date yet showed no trend over time, or in relation to increasing SST or the proportion of principal prey in the diet, as would be expected if trophic mismatch was increasing. At the individual level, we found evidence for stabilising selection and directional selection for earlier breeding, although the earliest birds were not the most productive. However, selection for earlier laying did not strengthen over time, or in relation to SST or slope of the seasonal shift in diet from principal to secondary prey. We found that the optimum lay date advanced by almost 4 weeks during the study, and that the population mean lay date tracked this shift.Our results indicate that average performance correlates with absolute timing of breeding of the population, and there is selection for earlier laying at the individual level. However, we found no fitness signatures of a change in the impact of climate‐induced trophic mismatch, and evidence that shags are tracking long‐term shifts in optimum timing. This suggests that if asynchrony is present in this system, breeding success is not impacted. Our approach highlights the advantages of examining variation at both population and individual levels when assessing evidence for fitness impacts of trophic asynchrony. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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266. The energetic cost of parasitism in a wild population.
- Author
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Hicks, Olivia, Green, Jonathan A., Burthe, Sarah J., Daunt, Francis, Newell, Mark, Butler, Adam, Motohiro Ito, and Katsufumi Sato
- Subjects
- *
PARASITES , *ENERGY consumption , *FLIGHT , *ACCELEROMETRY , *PERFORMANCE - Abstract
Parasites have profound fitness effects on their hosts, yet these are often sub-lethal, making them difficult to understand and quantify. A principal sub-lethal mechanism that reduces fitness is parasite-induced increase in Parasites have profound fitness effects on their hosts, yet these are often sub-lethal, making them difficult to understand and quantify. A principal sub-lethal mechanism that reduces fitness is parasite-induced increase in energetic costs of specific behaviours, potentially resulting in changes to time and energy budgets. However, quantifying the influence of parasites on these costs has not been undertaken in free-living animals. We used accelerometers to estimate energy expenditure on flying, diving and resting, in relation to a natural gradient of endo-parasite loads in a wild population of European shags Phalacrocorax aristotelis. We found that flight costs were 10% higher in adult females with higher parasite loads and these individuals spent 44% less time flying than females with lower parasite loads. There was no evidence for an effect of parasite load on daily energy expenditure, suggesting the existence of an energy ceiling, with the increase in cost of flight compensated for by a reduction in flight duration. These behaviour specific costs of parasitism will have knock-on effects on reproductive success, if constraints on foraging behaviour detrimentally affect provisioning of young. The findings emphasize the importance of natural parasite loads in shaping the ecology and life-history of their hosts, which can have significant population level consequences. [ABSTRACT FROM AUTHOR]
- Published
- 2018
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267. Quantifying the impacts of predation by Great Black-backed Gulls Larus marinus on an Atlantic Puffin Fratercula arctica population: Implications for conservation management and impact assessments.
- Author
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Langlois Lopez, Samuel, Daunt, Francis, Wilson, Jared, O'Hanlon, Nina J., Searle, Kate R., Bennett, Sophie, Newell, Mark A., Harris, Michael P., and Masden, Elizabeth
- Subjects
- *
PREDATION , *POPULATION viability analysis , *OFFSHORE wind power plants , *WILDLIFE management areas , *GULLS , *WILDLIFE conservation , *CONFLICT management , *FUSION reactor blankets - Abstract
The management of predator-prey conflicts can be a key aspect of species conservation. For management approaches to be effective, a robust understanding of the predator-prey relationship is needed, particularly when both predator and prey are species of conservation concern. On the Isle of May, Firth of Forth, Scotland, numbers of breeding Great Black-backed Gulls Larus marinus , a generalist predator, have been increasing since the 1980s, which has led to increasing numbers of sympatrically breeding Atlantic Puffins Fratercula arctica being predated during the breeding season. This may have consequences for species management on the Isle of May and impact assessments of offshore windfarms in the wider Firth of Forth area. We used population viability analysis to quantify under what predation pressure the Atlantic Puffin population may decline and become locally extinct over a three-generation period. The predation level empirically estimated in 2017 (1120 Puffins per year) was not sufficient to drive a decline in the Puffin population. Rather, an increase to approximately 3000 Puffins per year would be required to cause a population decline, and >4000 to drive the population to quasi-extinction within 66 years. We discuss the likelihood of such a scenario being reached on the Isle of May, and we recommend that where predator-prey conflicts occur, predation-driven mortality should be regularly quantified to inform conservation management and population viability analyses associated with impact assessments. • Seabird predation by other seabirds may impact the demographic rates of seabird populations. • Population Viability Analysis as a useful tool to quantify predator-prey conflicts. • Quantifying seabird predation is key to inform predator-prey management. • Quantifying seabird predation can improve accuracy of impact assessments. [ABSTRACT FROM AUTHOR]
- Published
- 2023
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268. Effects of a fishery closure and prey abundance on seabird diet and breeding success: Implications for strategic fisheries management and seabird conservation.
- Author
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Searle, Kate R., Regan, Charlotte E., Perrow, Martin R., Butler, Adam, Rindorf, Anna, Harris, Michael P., Newell, Mark A., Wanless, Sarah, and Daunt, Francis
- Subjects
- *
FISHERY closures , *PREY availability , *FISHERY management , *FORAGE fishes , *COLONIES (Biology) , *FISHERIES , *FISH conservation - Abstract
Industrial forage fish fisheries may reduce prey availability affecting diet and breeding success of marine predators. However, evidence for fisheries effects on predator demography remains rare, hindering evaluation of their impact on populations. Using 25 years of data on the commercial lesser sandeel fishery in the north-western North Sea, we evaluated the effectiveness of the closure in safeguarding breeding success of four seabird species - black-legged kittiwake, common guillemot, Atlantic puffin and razorbill. We also tested for effects of a scientific fishery in the closed area on breeding success. We quantified how changes in the diet of chicks for the four seabird species were influenced by the abundance of sandeels and the alternative prey species, European sprat, and the potential prey behavioural disturbance effects of sandeel fishing on the prey. Finally, we examined how changes in chick diet and prey abundance have shaped long-term variation in seabird breeding success. The period of fishery operation was associated with a decline in kittiwake breeding success in colonies with foraging ranges overlapping the closed area, from 52 % of young fledged pre-fishery to 23 % during fishery operation. Breeding success increased by approximately 10 % in the period following fishery closure to 2018. We document wide uncertainty around this increase in breeding success, partly driven by variation in the responses of individual colonies. For guillemot, razorbill and puffin we found no evidence for negative effects of the fishery on breeding success, nor for positive effects arising from its closure. We found no evidence for an impact on breeding success of the scientific fishery. The proportion of sandeel in chick diet was positively associated with breeding success in the four species, albeit with only weak evidence for puffin. Fishing effort was associated with a decreased proportion of sandeel in puffin diet, a lower proportion of the sandeel component of the diet consisting of 0-group in kittiwake, razorbill and puffin, and with decreased kittiwake breeding success. Our findings provide quantitative evidence for how forage fish fisheries may impact seabird demography, highlighting the species-specific nature of responses, and the difficulties in teasing apart drivers amongst ongoing environmental change. Time-area fisheries closures show promise as a tool for positively affecting productivity in some seabird species. However, we identify important caveats around its effectiveness for strategic seabird conservation and aspirations of net gain. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
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269. Reproductive performance of resident and migrant males, females and pairs in a partially migratory bird.
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Grist, Hannah, Daunt, Francis, Wanless, Sarah, Burthe, Sarah J., Newell, Mark A., Harris, Mike P., Reid, Jane M., and Bouwhuis, Sandra
- Subjects
- *
MIGRATORY birds , *FEMALES , *MALES , *LIFE , *BIRDS - Abstract
1. Quantifying among-individual variation in life-history strategies and associated variation in reproductive performance and resulting demographic structure, is key to understanding and predicting population dynamics and life-history evolution. Partial migration, where populations comprise a mixture of resident and seasonally migrant individuals, constitutes a dimension of life-history variation that could be associated with substantial variation in reproductive performance. However, such variation has rarely been quantified due to the challenge of measuring reproduction and migration across a sufficient number of seasonally mobile males and females. 2. We used intensive winter (non-breeding season) resightings of colour-ringed adult European shags (Phalacrocorax aristotelis) from a known breeding colony to identify resident and migrant individuals. We tested whether two aspects of annual reproductive performance, brood hatch date and breeding success, differed between resident and migrant males, females and breeding pairs observed across three consecutive winters and breeding seasons. 3. The sex ratios of observed resident and migrant shags did not significantly differ from each other or from 1:1, suggesting that both sexes are partially migratory and that migration was not sex-biased across surveyed areas. 4. Individual resident males and females hatched their broods 6 days earlier and fledged 0.2 more chicks per year than migrant males and females on average. Resident individuals of both sexes therefore had higher breeding success than migrants. 5. Hatch date and breeding success also varied with a pair's joint migratory strategy such that resident-resident pairs hatched their broods 12 days earlier than migrant-migrant pairs and fledged 0.7 more chicks per year on average. However, there was no evidence of assortative pairing with respect to migratory strategy: observed frequencies of migrant-migrant and resident-resident pairs did not differ from those expected given random pairing. 6. These data demonstrate substantial variation in two key aspects of reproductive performance associated with the migratory strategies of males, females and breeding pairs within a partially migratory population. These patterns could reflect direct and/or indirect mechanisms, but imply that individual variation in migratory strategy and variation in pairing among residents and migrants could influence selection on migration and drive complex population and evolutionary dynamics. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
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270. Prehospital Fluid Resuscitation: What Type, How Much, and Controversies
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Newell, Mark, Gracias, Vincente, and Rotondo, Michael
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271. Parental age influences offspring telomere loss.
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Heidinger, Britt J., Herborn, Katherine A., Granroth‐Wilding, Hanna M.V., Boner, Winnie, Burthe, Sarah, Newell, Mark, Wanless, Sarah, Daunt, Francis, Monaghan, Pat, and Blanckenhorn, Wolf
- Subjects
- *
SHAG (Bird) , *PARENTAL age , *TELOMERES , *LONGEVITY , *POPULATION - Abstract
The age of the parents at the time of offspring production can influence offspring longevity, but the underlying mechanisms remain poorly understood. The effect of parental age on offspring telomere dynamics (length and loss rate) is one mechanism that could be important in this context., Parental age might influence the telomere length that offspring inherit or age-related differences in the quality of parental care could influence the rate of offspring telomere loss. However, these routes have generally not been disentangled., Here, we investigated whether parental age was related to offspring telomere dynamics using parents ranging in age from 2 to 22 years old in a free-living population of a long-lived seabird, the European shag ( Phalacrocorax aristotelis). By measuring the telomere length of offspring at hatching and towards the end of the post-natal growth period, we could assess whether any potential parental age effect was confined to the post-natal rearing period., There was no effect of maternal or paternal age on the initial telomere length of their chicks. However, chicks produced by older mothers and fathers experienced significantly greater telomere loss during the post-natal nestling growth period. We had relatively few nests in which the ages of both parents were known, and individuals in this population mate assortatively with respect to age. Thus, we could not conclusively determine whether the parental age effect was due to maternal age, paternal age, or both; however, it appears that the effect is stronger in mothers., These results demonstrate that in this species, there was no evidence that parental age was related to offspring hatching telomere length. However, telomere loss during nestling growth was reduced in the offspring of older parents. This could be due to an age-related deterioration in the quality of the environment that parents provide, or because parents that invest less in offspring rearing live to an older age. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
272. Do early warning indicators consistently predict nonlinear change in long-term ecological data?
- Author
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Burthe, Sarah J., Henrys, Peter A., Mackay, Eleanor B., Spears, Bryan M., Campbell, Ronald, Carvalho, Laurence, Dudley, Bernard, Gunn, Iain D. M., Johns, David G., Maberly, Stephen C., May, Linda, Newell, Mark A., Wanless, Sarah, Winfield, Ian J., Thackeray, Stephen J., Daunt, Francis, and Allen, Craig
- Subjects
- *
BIOINDICATORS , *ENVIRONMENTAL databases , *CLIMATE change , *BALLISTIC missile early warning system , *AUTOCORRELATION (Statistics) - Abstract
Anthropogenic pressures, including climate change, are causing nonlinear changes in ecosystems globally. The development of reliable early warning indicators ( EWIs) to predict these changes is vital for the adaptive management of ecosystems and the protection of biodiversity, natural capital and ecosystem services. Increased variance and autocorrelation are potential early warning indicators and can be readily estimated from ecological time series. Here, we undertook a comprehensive test of the consistency between early warning indicators and nonlinear abundance change across species, trophic levels and ecosystem types., We tested whether long-term abundance time series of 55 taxa (126 data sets) across multiple trophic levels in marine and freshwater ecosystems showed (i) significant nonlinear change in abundance 'turning points' and (ii) significant increases in variance and autocorrelation ('early warning indicators'). For each data set, we then quantified the prevalence of three cases: true positives (early warning indicators and associated turning point), false negatives (turning point but no associated early warning indicators) and false positives (early warning indicators but no turning point)., True positives were rare, representing only 9% (16 of 170) of cases using variance, and 13% (19 of 152) of cases using autocorrelation. False positives were more prevalent than false negatives (53% vs. 38% for variance; 47% vs. 40% for autocorrelation). False results were found in every decade and across all trophic levels and ecosystems., Time series that contained true positives were uncommon (8% for variance; 6% for autocorrelation), with all but one time series also containing false classifications. Coherence between the types of early warning indicators was generally low with 43% of time series categorized differently based on variance compared to autocorrelation., Synthesis and applications. Conservation management requires effective early warnings of ecosystem change using readily available data, and variance and autocorrelation in abundance data have been suggested as candidates. However, our study shows that they consistently fail to predict nonlinear change. For early warning indicators to be effective tools for preventative management of ecosystem change, we recommend that multivariate approaches of a suite of potential indicators are adopted, incorporating analyses of anthropogenic drivers and process-based understanding. [ABSTRACT FROM AUTHOR]
- Published
- 2016
- Full Text
- View/download PDF
273. Tactical-level Public Affairs and information operations
- Author
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Newell, Mark R., Maj
- Subjects
PUBLIC INFORMATION ,INFORMATION WARFARE ,INFORMATION MANAGEMENT - Abstract
illus bibliog
- Published
- 1999
274. Reflagging: 2d Armored Division becomes the 4th Infantry Division (Mechanized)
- Author
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Newell, Mark R., Maj
- Subjects
ARMY - Corps, Divisions, etc - United States ,INACTIVATION OF INSTALLATIONS AND UNITS - Army - Abstract
illus
- Published
- 1996
275. 4th ID (Infantry Division) pioneers new division design
- Author
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Newell, Mark, Maj
- Subjects
ARMY - United States - Organization ,ARMY - Corps, Divisions, etc - United States ,FUTURE - Abstract
illus
- Published
- 1998
276. Breeding density, fine-scale tracking, and large-scale modeling reveal the regional distribution of four seabird species.
- Author
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Wakefield ED, Owen E, Baer J, Carroll MJ, Daunt F, Dodd SG, Green JA, Guilford T, Mavor RA, Miller PI, Newell MA, Newton SF, Robertson GS, Shoji A, Soanes LM, Votier SC, Wanless S, and Bolton M
- Subjects
- Animals, Charadriiformes physiology, Ireland, Models, Biological, Population Density, United Kingdom, Animal Distribution, Birds physiology, Feeding Behavior, Nesting Behavior
- Abstract
Population-level estimates of species' distributions can reveal fundamental ecological processes and facilitate conservation. However, these may be difficult to obtain for mobile species, especially colonial central-place foragers (CCPFs; e.g., bats, corvids, social insects), because it is often impractical to determine the provenance of individuals observed beyond breeding sites. Moreover, some CCPFs, especially in the marine realm (e.g., pinnipeds, turtles, and seabirds) are difficult to observe because they range tens to ten thousands of kilometers from their colonies. It is hypothesized that the distribution of CCPFs depends largely on habitat availability and intraspecific competition. Modeling these effects may therefore allow distributions to be estimated from samples of individual spatial usage. Such data can be obtained for an increasing number of species using tracking technology. However, techniques for estimating population-level distributions using the telemetry data are poorly developed. This is of concern because many marine CCPFs, such as seabirds, are threatened by anthropogenic activities. Here, we aim to estimate the distribution at sea of four seabird species, foraging from approximately 5,500 breeding sites in Britain and Ireland. To do so, we GPS-tracked a sample of 230 European Shags Phalacrocorax aristotelis, 464 Black-legged Kittiwakes Rissa tridactyla, 178 Common Murres Uria aalge, and 281 Razorbills Alca torda from 13, 20, 12, and 14 colonies, respectively. Using Poisson point process habitat use models, we show that distribution at sea is dependent on (1) density-dependent competition among sympatric conspecifics (all species) and parapatric conspecifics (Kittiwakes and Murres); (2) habitat accessibility and coastal geometry, such that birds travel further from colonies with limited access to the sea; and (3) regional habitat availability. Using these models, we predict space use by birds from unobserved colonies and thereby map the distribution at sea of each species at both the colony and regional level. Space use by all four species' British breeding populations is concentrated in the coastal waters of Scotland, highlighting the need for robust conservation measures in this area. The techniques we present are applicable to any CCPF., (© 2017 by the Ecological Society of America.)
- Published
- 2017
- Full Text
- View/download PDF
277. Genomic selection in plant breeding.
- Author
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Newell MA and Jannink JL
- Subjects
- Genetic Markers, Genome, Plant, Plants genetics, Selection, Genetic, Breeding, Software
- Abstract
Genomic selection (GS) is a method to predict the genetic value of selection candidates based on the genomic estimated breeding value (GEBV) predicted from high-density markers positioned throughout the genome. Unlike marker-assisted selection, the GEBV is based on all markers including both minor and major marker effects. Thus, the GEBV may capture more of the genetic variation for the particular trait under selection.
- Published
- 2014
- Full Text
- View/download PDF
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