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Abstract Various erythropoietic abnormalities are highly prevalent among patients with pulmonary arterial hypertension (PAH) and associated with worse disease severity. Given the poorly understood yet important roles of dysregulated erythropoiesis and iron metabolism in PAH, we sought to further characterize the hematologic and iron profiles in PAH and their relationship to PAH severity. We recruited 67 patients with PAH and 13 healthy controls. Hemodynamics attained within 1 year of blood sample collection were available for 36 patients. Multiple hematologic, iron, and inflammatory parameters were evaluated for their association with hemodynamics. The subset with hemodynamic data consisted of 29 females (81%). The most common etiologies were idiopathic PAH (47%) and connective tissue disease‐related PAH (33%). 19 (53%) had functional class 3 or 4 symptomatology, and 12 (33%) were on triple pulmonary vasodilator therapy. Immature reticulocyte fraction (IRF) had significant positive correlations with mean pulmonary artery (PA) pressure (mPAP) (0.59, p

The nursery industry produces and sells plants for landscape and environmental purposes and represents a major sector within the US agricultural industry. In recent years, the nursery industry has undergone rapid growth as a result of various factors, including increased demand from housing development and pandemic-fueled interest in home horticulture. As with any industry, the nursery industry must adapt to changes in societal trends to sustain growth. In the wake of unprecedented societal and supply chain issues stemming from the global coronavirus disease 2019 pandemic, the American Society for Horticultural Science Nursery Crops Professional Interest Group gathered experts in various disciplines to provide their opinions and insights into the future of the nursery industry, focusing specifically on the changes and challenges the nursery industry will face in the coming decade. Nursery crop specialists spanning the United States identified three primary areas that will steer the future momentum of the nursery industry: consumer trends, natural resources, and labor. Six experts were selected to represent these areas in a workshop held Jul 2022 at the American Society for Horticultural Science Annual Conference in Chicago, IL, USA. This article was developed to disseminate to the greater scientific community the discussions held and insight shared during that workshop.

Walking is crucial for independence and quality of life. This study leverages wrist-worn sensor data from UK Biobank participants to establish normative daily-life walking data, stratified by age and sex, to provide benchmarks for research and clinical practice. The Watch Walk digital biomarkers were developed, validated, and applied to 92,022 participants aged 45–79 who wore a wrist sensor for at least three days. Normative data were collected for daily-life walking speed, step-time variability, step count, and 17 other gait and sleep biomarkers. Test–retest reliability was calculated, and associations with sex, age, self-reported walking pace, and mobility problems were examined. Population mean maximal and usual walking speeds were 1.49 and 1.15 m/s, respectively. The daily step count was 7749 steps, and step regularity was 65%. Women walked more regularly but slower than men. Walking speed, step count, longest walk duration, and step regularity decreased with age. Walking speed is associated with sex, age, self-reported pace, and mobility problems. Test–retest reliability was good to excellent (ICC ≥ 0.80). This study provides large-scale normative data and benchmarks for wrist-sensor-derived digital gait and sleep biomarkers from real-world data for future research and clinical applications.

Eastern filbert blight (EFB) and pacific flatheaded borer (PFB) are two problems of Pacific Northwest orchard and nursery production. Fungicides and insecticides used to manage these issues are typically applied to plant tissues with minimal foliage present that can result in considerable spray waste or drift. The Intelligent Spray System (ISS) is a laser-guided, variable-rate sprayer that detects objects in the target zone and releases spray volumes proportional to the density of plant tissues, thereby increasing application efficiency and reducing waste. However, the ISS has not been tested when targeting low-foliage plant tissues such as emerging shoots and trunks. Three experiments were conducted from 2018 to 2021 to evaluate the potential use of the ISS for EFB and PFB management by assessing spray coverage on emerging hazelnut shoot tips, hazelnut tree trunks, and maple tree trunks. On hazelnut shoot tips, coverage was

Increased urban and suburban populations in the arid western United States have resulted in more water demand; however, water availability in the region has become limited because of inadequate precipitation. Recent droughts have led to restrictions on irrigating landscape plants. Garden rose (Rosa ×hybrida) is commonly used as flowering plants in residential landscapes, but its drought tolerance has not been widely studied. The objective of this study was to determine the impact of reduced irrigation frequency on visual quality, plant growth, and physiology of five garden rose cultivars, including ChewPatout (Oso Easy® Urban Legend®), Meibenbino (Petite Knock Out®), MEIRIFTDAY (Oso Easy® Double Pink), Overedclimb (Cherry Frost™), and Radbeauty (Sitting Pretty™). Twenty-four plants of each rose cultivar were established in a trial plot at Utah Agricultural Experiment Station Greenville Research Farm (North Logan, UT, USA) in Summer 2021. Plants were randomly assigned to one of three deficit irrigation treatments for which irrigation frequencies were calculated using 80% reference evapotranspiration (ETO) (high), 50% ETO (medium), and 20% ETO (low). The total volumes of irrigation water applied to each plant were 345.6, 172.8, and 43.2 L for the high, medium, and low irrigation frequencies, respectively, during the deficit irrigation trial from 12 May to 30 Sep 2022. Root zones were wetted more frequently as irrigation frequency increased from low to high irrigation frequencies. Decreased irrigation frequency increased the number of visibly wilted and damaged leaves on all rose cultivars. However, only ‘Meibenbino’ and ‘MEIRIFTDAY’ exhibited a reduction in overall appearance under decreased irrigation frequency. The relative growth indices of both ‘Meibenbino’ and ‘MEIRIFTDAY’ decreased by 6%, whereas the dry weights of their leaves decreased by 37% and 36%, respectively, as irrigation decreased from high to low frequencies. Roses in this study appeared to decrease stomatal conductance up to 51% when irrigation decreased from high to low frequencies, or when air temperature increased. ‘Meibenbino’ and ‘MEIRIFTDAY’ exhibited unacceptable overall appearance, growth reduction, and higher leaf–air temperature differences, and they were less tolerant to reduced irrigation. Although the ‘Radbeauty’ maintained plant growth under the reduced irrigation frequency, the large leaf size led to a more visibly wilted appearance and the potential for heat stress, thus impairing visual quality. ‘ChewPatout’ and ‘Overedclimb’ were most tolerant to deficit irrigation at 20% ETO and maintained plant growth with acceptable visual quality and lower leaf temperatures when they received one irrigation during the growing season.

Abstract Digital gait biomarkers (including walking speed) indicate functional decline and predict hospitalization and mortality. However, waist or lower-limb devices often used are not designed for continuous life-long use. While wrist devices are ubiquitous and many large research repositories include wrist-sensor data, widely accepted and validated digital gait biomarkers derived from wrist-worn accelerometers are not available yet. Here we describe the development of advanced signal processing algorithms that extract digital gait biomarkers from wrist-worn devices and validation using 1-week data from 78,822 UK Biobank participants. Our gait biomarkers demonstrate good test–retest-reliability, strong agreement with electronic walkway measurements of gait speed and self-reported pace and significantly discriminate individuals with poor self-reported health. With the almost universal uptake of smart-watches, our algorithms offer a new approach to remotely monitor life-long population level walking speed, quality, quantity and distribution, evaluate disease progression, predict risk of adverse events and provide digital gait endpoints for clinical trials.

Widespread outbreaks of tomato powdery mildew (Leveillula taurica and Oidium neolycopersici) are problematic in fresh market tomato (Solanum lycopersicum) crops in western Oregon, USA. In western Oregon, fresh market tomatoes are frequently grown in greenhouses or high tunnels where conditions can promote diseases such as powdery mildew. Heightened concerns about worker safety limit the pesticides available for use in enclosed systems. We studied the efficacy of ultraviolet-C (UV-C) light applications under high-tunnel conditions compared with a standard fungicide program. Plants treated with UV-C had zero incidence of powdery mildew on all sample dates in the first trial. In trial 2, disease incidence was lower on UV-C treated plants than both grower standard and nontreated control early in the study while disease severity remained lower in UV-C than nontreated control and similar to grower standard treatment. Additional research is needed to optimize UV-C treatment intervals to minimize negative effects on plant growth and maximize powdery mildew control.

Introduction Physical activity has health benefits, including lowered obesity, diabetes and hypertension levels. However, participation in regular physical activities among undergraduate students is declining and, instead, physical inactivity sets the path for sedentarism. Strategies and best practices used to enhance participation in regular physical activities among undergraduate students are beneficial for mitigating sedentariness and promoting healthy lifestyles. Therefore, this study aims to present a systematic review protocol that focuses on the strategies and best practices used to enhance participation in regular physical activities among undergraduate university students.Methods and analysis Quantitative, qualitative and mixed-methods design studies will be included and appraised. The following databases will be searched: PubMed, Science Direct, Academic Search Complete, ERIC, Web of Science, SAGE, CINAHL Plus and SPORTDiscus. Database searches on physical activities among undergraduate university students will be generated to answer the following research question: What are the strategies and best practices used to enhance participation in regular physical activities among undergraduate university students? Two independent reviewers will conduct the primary screening of articles from 2011 to 2022. A third reviewer will be consulted to solve any disagreements. Study selection will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines, and study quality will be assessed by the Johanna Biggs Institute checklist. Results from the selected articles will be extracted, summarised and categorised based on the type of study participants, study design and setting, and methodological quality. A narrative description will synthesise the findings to answer the objectives of this review.Ethics and dissemination Ethics approval for this study was granted by the Humanities and Social Science Research Ethics Committee at the University of the Western Cape, reference number: HS21/10/24. The results will be disseminated through a peer-reviewed publication and conference presentation.

To optimize pesticide applications to the canopies of deciduous perennial crops, spray volume should be adjusted throughout the year to match the changes in canopy volume and density. Machine-vision, computer-controlled, variable-rate sprayers are now commercially available and claim to provide adequate coverage with decreased spray volumes compared with constant-rate sprayers. However, there is little research comparing variable- and constant-rate spray applications as crop characteristics change throughout a growing season. This study evaluated spray volume, spray quality (e.g., coverage and deposit density), and off-target spray losses of variable- and constant-rate sprayers across multiple phenophases in an apple (Malus domestica) orchard and a grape (Vitis vinifera) vineyard. The variable-rate sprayer mode applied 67% to 74% less volume in the orchard and 61% to 80% less volume in the vineyard. Spray coverage (percent), measured by water-sensitive cards (WSC), was consistently greater in the constant-rate mode compared with the variable-rate mode, but in many cases, excessive coverage (i.e., over-spray) was recorded. The variable-rate sprayer reduced off-target losses, measured by WSC coverage, up to 40% in the orchard and up to 33% in the vineyard. Spray application deposit densities (droplets per square centimeter) on target canopies were typically greater in variable-rate mode. However, the deposit densities were confounded in over-spray conditions because droplets coalesced on the WSC resulting in artificially low values (i.e., few, very large droplets). Spray efficiencies were most improved early in the growing season, when canopy density was lowest, demonstrating the importance of tailoring spray volume to plant canopy characteristics.

Here we describe the identification of genes and their encoded proteins that are expressed in advanced grade tumors by reconstruction of a sarcoma cancer testis gene 1b/a (catg1b/a) network. CTAG1B/A is an ortholog of the yeast/Drosophila transcription factor Pcc1p, and a member of the KEOPS transcription complex. It has been implicated in telomere maintenance and transcriptional regulation through association with chromatin remodeling factors and is only expressed during adult testis germ cell differentiation. Ctag1b/a is re-activated in synovial sarcomas and myxoid liposarcomas but not in differentiated liposarcomas. We mapped CTAG1B/A protein to sarcoma transcription pathways with gene set expression analysis (GSEA) and using independent samples, we immunohistochemically identified expression of at least two network neighbors, RANBP2, and TLE1, thus validating our approach. This work demonstrates that mapping unknown genes to functional pathways by network re-construction is a powerful tool that can be used to identify candidate oncoproteins.

Development of more efficient and sustainable irrigation technology is critical to maintain horticultural production in a water scarce future. Sensor controlled irrigation is an emerging technology that has the potential to increase irrigation efficiency and reduce overwatering by using real-time data on container water status to control the timing and volume of irrigation events. This project presents a novel irrigation control system using lysimetry. We develop small scale lysimeters, referred to as mini-lysimeter, which provide a direct measure of actual evapotranspiration (ET) via a change in mass of containerized crops. As such, mini-lysimeter sensors have the potential to be an effective instrument for automatic irrigation scheduling. This paper presents the mini-lysimeter controlled irrigation system design in detail, including the mini-lysimeter sensors, data logger and control system configuration, and the hardware needed to integrate the control system into existing irrigation infrastructure. A proof of concept study is presented where mini-lysimeter (ML) controlled irrigation is compared to a traditional timer-based irrigation schedule. Results show that the ML controlled irrigation system can produce plants of equal size to traditional irrigation methods while using 26% less water on average. The outcome of this study indicates that the hardware presented here is reliable and robust enough to produce quality plants in a real nursery production setting, and this technology provides a novel approach to improving water efficiency in container nurseries.

Potted poinsettia (Euphorbia pulcherrima) is an important commercial commodity for the U.S. floriculture industry. The production of poinsettia demands intensively managed light control, heat, fertilizer, and water; inhibiting elongation with plant growth regulators, and protecting plants from diseases and pests with pesticide applications. Excessive irrigation creates pollution, promotes disease, and is expensive. Sensor-based control systems can optimize irrigation schedules. Irrigation management is crucial in nursery production of poinsettias because water is a limited resource and agricultural runoff is monitored in many states across the United States. By pairing environmental sensors with sensors that continuously monitor plant transpiration, we can determine how plant water use and water stress fluctuate with environmental and physiological demands. We hypothesized that continual measurements of sap flow could be correlated with environmental sensors to develop a new water stress index (WSI), which can deliver the benefits of detecting water stress that might affect the quality of potted poinsettias. To test this hypothesis, rooted cuttings of poinsettia (E. pulcherrima cv. Prestige Red) were individually potted into twelve 11-L black plastic nursery pots. Potted plants were grown in a naturally illuminated temperature-controlled glasshouse. The 12 plants were randomly assigned one of three watering treatments: weekly, biweekly, and triweekly irrigation. From the data collected, we were able to create a WSI that correlated available soil moisture with the difference between the expected transpiration with actual transpiration rates. Our results suggest that the plants in the weekly treatment group did not experience water stress until 0.3 m3·m–3 volume water content indicated by

Abstract Background While a number of studies have investigated knee symptoms among elite athletes, few have directly compared the association between engagement in different sports and knee symptoms among young adults in the general population. The current study aimed to investigate the relation between sports participation hours, type/ number of sports engaged, self-rated competitiveness and knee symptoms among undergraduates. Methods Undergraduates were invited to participate in a self-administered online survey through invitation emails. Respondents were instructed to provide demographic information (e.g., age, gender, sports participation hours, types of engaged sports, self-rated competitiveness in sports and anxiety level etc.) and to report knee symptoms (current, the last 7 days, the last 12 months, and lifetime). Multiple logistic regressions were conducted to investigate the association between sports participation and current knee symptoms. Results Of 17,552 invitees, 3744 responded to the survey. Valid data from 3053 respondents was used for analysis. Forty-four percent of the respondents engaged in sports regularly (≥once per week). Running, cross-training and swimming were the most frequently participated sports among the respondents. The current prevalence rate of knee symptoms was 6.4%. Hours spent participating in combat sports, soccer, yoga, and basketball participation hours were significantly associated with current knee symptoms. Respondents who rated themselves as “competitive” demonstrated a higher risk of having current knee symptoms than “recreational” players. Number of engaged sports was not associated with current knee symptoms among undergraduates. Conclusions Certain sports types were associated with current knee symptoms. Compared to self-rated “recreational” players, self-rated “competitive” players were more likely to have current knee symptoms. Students should take preventive measures to minimize their risk of developing knee symptoms, especially when participating in combat sports, soccer, yoga, and basketball, or engaging in sports at a highly competitive level.

Plant nursery production systems are a multi-billion-dollar, international, and horticultural industry that depends on storing and shipping live plants. The storage environment represents potentially desiccating and even fatal conditions for dormant, bareroot, and deciduous horticulture crops, like orchard trees, forestry trees, ornamental trees, and grapevines. When tree mortality is considered within a plant hydraulic framework, plants experiencing water stress are thought to ultimately die from hydraulic failure or carbon starvation. We hypothesized that the hydraulic framework can be applied to stored crops to determine if hydraulic failure or carbon starvation could be attributed to mortality. We used deciduous trees as model species because they are important horticultural crops and provide a diversity of hydraulic strategies. We selected cultivars from six genera: Acer, Amelanchier, Gleditsia, Gymnocladus, Malus, and Quercus. For each cultivar, we measured stem hydraulic conductance and vulnerability to embolism. On a weekly basis for 14 weeks (March–June), we removed trees of each cultivar from cold storage (1–2°C). Each week and for each cultivar, we measured stem water potential and water content (n = 7) and planted trees to track survival and growth (n = 10). At three times during this period, we also measured non-structural carbohydrates. Our results showed that for four cultivars (Acer, Amelanchier, Malus, and Quercus), the stem water potentials measured in trees removed from storage did not exceed stem P50, the water potential at which 50% of stem hydraulic conductivity is lost. This suggests that the water transport system remains intact during storage. For two cultivars (Gleditsia and Gymnocladus), the water potential measured on trees out of storage exceeded stem P50, yet planted trees from all weeks survived and grew. In the 14 weeks, there were no significant changes or directional trends in stem water potential, water content, or NSC for most cultivars, with a few exceptions. Overall, the results show that the trees did not experience detrimental water relations or carbon starvation thresholds. Our results suggest that many young deciduous trees are resilient to conditions caused by prolonged dormancy and validate the current storage methods. This experiment provides an example of how a mechanistically based understanding of physiological responses can inform cold storage regimes in nursery tree production.

Background: Some interstitial lung disease (ILD) patients develop a progressive fibrosing-ILD phenotype (PF-ILD), with similar persistent lung function decline suggesting common molecular pathways involved. Nintedanib, a tyrosine kinase inhibitor targeting the PDGF, FGF, VEGF and M-CSF pathways, has shown comparable efficacy in idiopathic pulmonary fibrosis (IPF) and systemic sclerosis-associated ILD (SSc-ILD). We hypothesize that Nintedanib targeted molecular pathways will be augmented to a similar degree across PF-ILD regardless of aetiology. Methods: We collected explanted lung tissue at the time of lung transplantation from 130 PF-ILD patients (99 (76%) IPF, 14 (11%) SSc-ILD, 17 (13%) other PF-ILD), and wedge biopsies from 200 donor lungs and measured PDGF, FGF, VEGF and M-CSF concentrations by Luminex. Findings: The concentrations of PDGF-AA, PDGF-BB, FGF-2, VEGF and M-CSF were significantly increased in PF-ILD lungs compared to donor lungs (PDGF-AA 93·0 pg/ml [±97·2] vs. 37·5 pg/ml [±35·4], p

Introduction Evidence suggests that abnormalities occur in the lung microvasculature in idiopathic pulmonary fibrosis (IPF). We hypothesised that dynamic contrast-enhanced (DCE)-magnetic resonance imaging (MRI) could detect alterations in permeability, perfusion and extracellular extravascular volume in IPF, thus providing in vivo regional functional information not otherwise available. Methods Healthy controls and IPF subjects underwent DCE-MRI of the thorax using a dynamic volumetric radial sampling sequence and administration of gadoterate meglumine at a dose of 0.1 mmol·kg−1 at 2 mL·s−1. Model-free analysis of signal intensity versus time curves in regions of interest from a lower, middle and upper axial plane, a posterior coronal plane and the whole lung yielded parameters reflective of perfusion and permeability (peak enhancement and rate of contrast arrival (kwashin)) and the extracellular extravascular space (rate of contrast clearance (kwashout)). These imaging parameters were compared between IPF and healthy control subjects, and between fast/slow IPF progressors. Results IPF subjects (n=16, 56% male, age (range) 67.5 (60–79) years) had significantly reduced peak enhancement and slower kwashin in all measured lung regions compared to the healthy volunteers (n=17, 65% male, age (range) 58 (51–63) years) on unadjusted analyses consistent with microvascular alterations. kwashout, as a measure of the extravascular extracellular space, was significantly slower in the lower lung and posterior coronal regions in the IPF subjects consistent with an increased extravascular extracellular space. All estimates were attenuated after adjusting for age. Similar trends were observed, but only the associations with kwashin in certain lung regions remained statistically significant. Among IPF subjects, kwashout rates nearly perfectly discriminated between those with rapidly progressive disease versus those with stable/slowly progressive disease. Conclusions DCE-MRI detects changes in the microvasculature and extravascular extracellular space in IPF, thus providing in vivo regional functional information.

The application of ultra-high spatial resolution imagery from small unpiloted aerial systems (sUAS) can provide valuable information about the status of built infrastructure following natural disasters. This study employs three methods for improving the value of sUAS imagery: (1) repeating the positioning of image stations over time using a bi-temporal imaging approach called repeat station imaging (RSI) (compared here against traditional (non-RSI) imaging), (2) co-registration of bi-temporal image pairs, and (3) damage detection using Mask R-CNN, a convolutional neural network (CNN) algorithm applied to co-registered image pairs. Infrastructure features included roads, buildings, and bridges, with simulated cracks representing damage. The accuracies of platform navigation and camera station positioning, image co-registration, and resultant Mask R-CNN damage detection were assessed for image pairs, derived with RSI and non-RSI acquisition. In all cases, the RSI approach yielded the highest accuracies, with repeated sUAS navigation accuracy within 0.16 m mean absolute error (MAE) horizontally and vertically, image co-registration accuracy of 2.2 pixels MAE, and damage detection accuracy of 83.7% mean intersection over union.

Repeat station imaging (RSI) is a method for specialized image collection and co-registration that facilitates rapid change detection with aerial imagery for time-critical analyses. Our previously reported research has defined methods for automated multitemporal image co-registration and demonstrated the utility of RSI for achieving precise co-registration, but without actually automating the technique. For this paper, we developed a custom software implementing specific procedures for automated RSI-based image co-registration, processed 252 image pairs containing diverse scenes and collection conditions, and evaluated the performance of RSI and the auto-registration tool. We found that the average root-mean-square error of image co-registration ranged between 1.3 and 1.9 pixels for aerial RSI images with 8–14 cm spatial resolution captured at the same time of day. The implications of these findings are that automated multitemporal co-registration and automated change detection could be performed in near real-time onboard an aircraft as it flies, opening up a range of new monitoring applications, particularly with unmanned aircraft systems. However, results with our custom software also indicate that images captured at different times of day with varying illumination and shadow conditions yield poor co-registration, and in some instances fail to register.

Various erythropoietic abnormalities are highly prevalent among patients with pulmonary arterial hypertension (PAH) and associated with worse disease severity. Given the poorly understood yet important roles of dysregulated erythropoiesis and iron metabolism in PAH, we sought to further characterize the hematologic and iron profiles in PAH and their relationship to PAH severity. We recruited 67 patients with PAH and 13 healthy controls. Hemodynamics attained within 1 year of blood sample collection were available for 36 patients. Multiple hematologic, iron, and inflammatory parameters were evaluated for their association with hemodynamics. The subset with hemodynamic data consisted of 29 females (81%). The most common etiologies were idiopathic PAH (47%) and connective tissue disease-related PAH (33%). 19 (53%) had functional class 3 or 4 symptomatology, and 12 (33%) were on triple pulmonary vasodilator therapy. Immature reticulocyte fraction (IRF) had significant positive correlations with mean pulmonary artery (PA) pressure (mPAP) (0.59, p

Multi-temporal aerial imagery captured via an approach called repeat station imaging (RSI) facilitates post-hazard assessment of damage to infrastructure. Spectral-radiometric (SR) variations caused by differences in shadowing may inhibit successful change detection based on image differencing. This study evaluates a novel approach to shadow classification based on bi-temporal imagery, which exploits SR change signatures associated with transient shadows. Changes in intensity (brightness from red–green–blue images) and intensity-normalized blue waveband values provide a basis for classifying transient shadows across a range of material types with unique reflectance properties, using thresholds that proved versatile for very different scenes. We derive classification thresholds for persistent shadows based on hue to intensity ratio (H/I) images, by exploiting statistics obtained from transient shadow areas. We assess shadow classification accuracy based on this procedure, and compare it to the more conventional approach of thresholding individual H/I images based on frequency distributions. Our efficient and semi-automated shadow classification procedure shows improved mean accuracy (93.3%) and versatility with different image sets over the conventional approach (84.7%). For proof-of-concept, we demonstrate that overlaying bi-temporal imagery also facilitates normalization of intensity values in transient shadow areas, as part of an integrated procedure to support near-real-time change detection.

The impetus for this special issue came at a somber time which was the 100th anniversary of the proclamation of the Chinese Immigration Act in 1923. This 15-page piece of [...]

A three-phase, 11-day training program designed to monitor elemental mercury (Hg0) emissions originating from gold shops was conducted in Georgetown and Bartica, Guyana, during May of 2019. The first phase consisted of interactive lectures and discussions on mercury use in artisanal and small-scale gold mining throughout Guyana, the region, and the world. In addition, specific training in the theory and use of analytical instrumentation to quantify Hg0 pollution associated with the processing of amalgams and sponge gold occurred. Trainees participated in the mapping of smelting facilities in Georgetown where, outside of one gold shop, Hg0 concentrations exceeded 100,000 ng/m3. During the second phase of training, a subset of trainees traveled to Bartica, where they mapped the town center to identify point sources of Hg0 pollution, all of which corresponded to the location of shops where amalgams and sponge gold were heated and purchased. Once mapped, Hg0 concentrations were measured during the smelting of gold inside the Guyana Gold Board (GGB) facility and two privately-owned gold shops. Maximum Hg0 concentrations at the GGB facility did not exceed 98,700 ng/m3 during the measurement period, while maximum concentrations at the two privately owned shops were measured as 527,500 ng/m3 and 302,200 ng/m3. With guidance from the training team, trainees were responsible for the collection and interpretation of all data. The third phase of the training involved the collaborative production of a report summarizing the findings from the training. This work represents the first formal training opportunity for the assessment of Hg0 concentrations in and around gold shops in Guyana, and provides baseline data to assist the government of Guyana to generate air quality standards for Hg0 emissions.

1H and 195Pt NMR are used to probe the spin ½ anion chain in the quasi-one-dimensional conductor Per2[Pt(mnt)2], which exhibits nearly simultaneous charge density wave (CDW) and spin-Peierls (SP) transitions at low temperatures (Tc ~ 8 K). Below Tc the [Pt(mnt)2] chain forms a spin-singlet state that is evident in 1H NMR spectra and spin relaxation (1/T1) rates; however minority unpaired Pt spins may remain in the SP ground state. With increasing magnetic field, the SP and CDW order parameters decrease in unison, indicating they are coupled up to a critical field Bc ~ 20 T. Above Bc, the spin singlet evolves into a spin-polarized configuration. The 195Pt NMR signals vanish as either Tc or Bc are approached from within the SP ground state, suggesting the hyperfine field of the Pt nucleus is significantly stronger than at the proton sites. Simulations yield a consistent picture of the angular, temperature, and magnetic field-dependent spectral features.

Large format digital camera (LFDC) systems are becoming more broadly available and regularly collect image data over large areas. Spectral and radiometric attributes of imagery from LFDC systems make this type of image data appropriate for semi-automated change detection. However, achieving accurate spatial co-registration between multitemporal image sets is necessary for semi-automated change detection. This study investigates the accuracy of co-registration between multitemporal image sets acquired using the Leica Geosystems ADS40, Intergraph Z/I Imaging® DMC, and Vexcel UltraCam-D sensors in areas of gentle, moderate, and extreme terrain relief. Custom image sets were collected and orthorectified by imagery vendors, with guidance from the authors. Results indicate that imagery acquired by vendors operating LFDC systems may be coregistered with pixel or sub-pixel level accuracy, even for environments with high terrain relief. Specific image acquisition and processing procedures facilitating this level of coregistration are discussed.

Se describe la operación de las red sísmicas de 30 estaciones que cubre las islas del Caribe Oriental, con centro en la Universidad de West Indies en Trinidad. La red incluye la vigilancia de 15 volcanes activos en un arco de 750 km de largo. La red tiene capacidad para detectar y localizar la mayoria de los eventos de M>2 en la región. Se describe la evolución de la red y algunas de sus estrategias de superación. doi: https://doi.org/10.22201/igeof.00167169p.1996.35.3.458

Sweet's Syndrome (SS), also known as acute febrile neutrophilic dermatosis, is one of several cutaneous inflammatory disorders classified as neutrophilic dermatoses. Respiratory complications are described in