133 research outputs found
Enhanced Floral Analysis by Low Temperature Scanning Electron Microscopy
Traditional methods of preparation of botanical specimens for scanning electron microscopy (SEM) have proven to induce artifacts in some specimens which often reduce quality of resulting images, and are highly misleading for taxonomic purposes. The advantages of low temperature SEM are illustrated by an investigation of freshly collected flowers, using a cryo-system interfaced to an SEM. This method overcame the deficiencies of traditional procedures to produce exceptional images of floral surfaces in their natural state. Depending on the nature of the material under investigation, the method my be indispensable (e.g., for accurate details of petal surfaces), preferable (e.g., glandular hairs are better shown than by critical point drying), inefficient (e.g., images of stigmas of equivalent clarity are obtainable by direct examination of unfixed uncoated material), or unrewarding (e.g., examination of dry herbarium specimens). This paper stresses previously unappreciated adaptive and taxonomic importance of microtopography of floral surfaces of several genera important as agricultural forage crops. Certain species have evolved adaptive petal surface microsculpturing that facilitates cross-pollination by their insect associates. In the cross-pollinating species examined, different petal areas appear to be specialized for the landing of pollinating insects, and perhaps also as tactile (braille-like) orientation guides to the hidden nectaries. By contrast, in related self-pollinating species and cultivars, and when flowers are clustered in a head that provides a landing platform for pollinators, these adaptations are reduced or absent
Policy makers ignoring science and scientists ignoring policy: the medical ethical challenges of heroin treatment
A decade of research in Switzerland, The Netherlands, Germany, and Spain now constitutes a massive body of work supporting the use of heroin treatment for the most difficult patients addicted to opiates. These trials concur on this method's safety and efficacy and are now serving as a prelude to the institution of heroin treatment in clinical practice throughout Europe. While the different sampling and research protocols for heroin treatment in these studies were important to the academic claims about specific results and conclusions that could be drawn from each study, the overall outcomes were quite clear – and uniformly positive. They all find that the use of prescribed pharmaceutical heroin does exactly what it is intended to do: it reaches a treatment refractory group of addicts by engaging them in a positive healthcare relationship with a physician, it reduces their criminal activity, improves their health status, and increases their social tenure through more stable housing, employment, and contact with family. The Canadian trial (NAOMI), now underway for over a year, but not yet completed, now faces a dilemma about what to do with its patients who have successfully completed 12 months of heroin and must be withdrawn from heroin and transferred to other treatments in accordance with the research protocol approved by Government of Canada, federal granting body and host institutions. The problem is that the principal criterion for acceptance to NAOMI was their history of repeated failure in these very same treatment programs to which they will now be referred. The existence of the results from abroad (some of which were not yet available when NAOMI was designed and initiated) now raises a very important question for Canada: is it ethical to continue to prohibit the medical use of heroin treatment that has already been shown to be feasible and effective in numerous medical studies throughout the world? And while this is being worked out, is it acceptable to require patients who have been successfully treated with heroin in Canada, to be forced to move back to less effective treatments (treatments that failed to be efficacious in the past)? This essay discusses this dilemma and places it in the broader context of ethics, science, and health policy. It makes the case for continuation of the current successful patients in heroin treatment and the institution of heroin treatment to all Canadian patients living with active addictions who qualify
The Relationship Between Drinking and Assertiveness in College Students
The relationship between drinking patterns of college students and their measured level of assertiveness was examined in this study. The subjects were categorized into six groups based on their self-reported frequency and amount of drinking. They were also asked to record the number of drinks they had drunk in the prior week. The MacAndrews Alcoholism Scale and the Rathus Assertion Schedule were administered to all the subjects. Pearson Product-moment correlations were calculated to assess the relationship between levels of drinking, the number of drinks in the prior week and scores from the Rathus Assertion Schedule and the MacAndrews Alcoholism Scale. The subjects were divided into two groups based on their scores obtained on the MacAndrews Scale: those whose score was 26 or above (prealcoholics) and those whose score was below 26 (Non-prealcoholic). Pearson Product-moment correlations were calculated to assess the relationship between the variables for these two groups. The results of the analysis did not support previous research that heavy drinking is associated with lower levels of assertiveness in alcoholics. In contrast to previous findings with alcoholics, the results indicated a very limited positive relationship between these variables for the non-prealcoholics, particularly the males, and no relationship at all for the prealcoholic subjects. It is suggested that the lack of assertiveness observed in alcoholics may develop after the onset of their alcoholism.
While it was expected that the drinking level of the subjects would be related to their scores on the MacAndrews Scale this was not the case. This finding suggests that drinking may not be a reliable predictor of alcoholism. Further research is suggested using a larger sample of only prealcoholics to determine what relationships exist between assertiveness, drinking and the prediction of alcoholism
Los marcadores microsatélite revelan la reestructuración genética de Medicago sinskiae (Fabaceae) en el oeste y el sudoeste de Irán
Medicago sinskiae appears to be a very rare species in the Iranian flora with only a few records in the last three decades. Eight populations (62 individuals) of M. sinskiae, one population of M. rigidula (seven individuals), and one population of M. constricta (five individuals) from western and southwestern Iran were analyzed for microsatellite data based on newly designed SSR primers using NGS technology. The PCoA, Clustering and Structure analyses showed no geographical pattern of genetically designated clusters. Our results showed that M. sinskiae is mainly an inbreeder. It is assumed that high levels of gene flow (Nm) and generation of genetically homogenous populations seem to be more affected by fast dispersal and not localized gene flow. Extensive collections recently made from the western and southwestern Iran showed that its presence is increasing. Finally, our results indicate that the species is segregated from its very close relatives M. rigidula and M. constricta in Iran.Medicago sinskiae es considerada una especie rara en la flora iraní con únicamente unas pocas citas en las tres últimas décadas. Se han muestreado ocho poblaciones (62 individuos) de M. sinskiae, una población de M. rigidula (siete individuos) y una población de M. constricta (cinco individuos) en el oeste y el suroeste de Irán que han sido analizadas con marcadores microsatélite. Se han utilizado nuevos primers obtenidos con tecnología NGS. Los análisis de PCoA, Clustering y Structure no muestran un patrón geográfico para los clústeres genéticos. Los resultados muestran que M. sinskiae es principalmente una especie autógama. Se asume que los altos niveles de flujo genético (Nm) y la homogeneidad genética poblacional están afectados por una rápida dispersión y un flujo genético no localizado. Recolecciones extensivas realizadas recientemente en el oeste y el suroeste de Iran muestran que el rango de distribución esta especie se está incrementando. Finalmente, nuestros resultados indican que M. sinskiae está diferenciada de las especies M. rigidula y M. constricta en Irán
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Barriers of solar energy uptake and the potential for mitigation solutions in Barbados
Understanding the barriers that inhibit the deployment of renewable energy technologies to achieve long-term reductions in carbon emissions from the use of fossil fuels is paramount to Barbados. Although there are targets towards renewable energy (solar, wind, biomass, geothermal) uptake, the share of these technologies in the energy mix does not exist in Barbados due to the total dependence on fossil fuels. In this paper, a review of potential challenges and the main problems for deployment of alternative energy sources is presented. Through interviews, questionnaires with a focus group of key personnel’s, the paper documents the lack of renewable energy sources (with emphasis on solar energy) as one of the main alternatives to meet the carbon emission targets set by the country. The barriers and challenges facing the implementation of solar energy deployment have been clarified. From the results, it is evident that significant policy barriers still exist at the country level, which has reduced the effectiveness of a concerted national effort to deploy renewables. The current policy landscape which benefits from fossil fuel imports, the lack of technical know-how and the lack of research and development in the renewable energy space are amongst the key barriers identified. The paper also outlines the key policy’s frameworks, regulatory environment and the lack of incentives, which encompasses the renewable energy sector, and presents a critical analysis of the barriers faced by the industry. A mitigation framework is proposed to bridge the gap of solar energy (renewable energy) deployment
Inhibition of the Mitochondrial Enzyme ABAD Restores the Amyloid-β-Mediated Deregulation of Estradiol
Alzheimer's disease (AD) is a conformational disease that is characterized by amyloid-β (Aβ) deposition in the brain. Aβ exerts its toxicity in part by receptor-mediated interactions that cause down-stream protein misfolding and aggregation, as well as mitochondrial dysfunction. Recent reports indicate that Aβ may also interact directly with intracellular proteins such as the mitochondrial enzyme ABAD (Aβ binding alcohol dehydrogenase) in executing its toxic effects. Mitochondrial dysfunction occurs early in AD, and Aβ's toxicity is in part mediated by inhibition of ABAD as shown previously with an ABAD decoy peptide. Here, we employed AG18051, a novel small ABAD-specific compound inhibitor, to investigate the role of ABAD in Aβ toxicity. Using SH-SY5Y neuroblastoma cells, we found that AG18051 partially blocked the Aβ-ABAD interaction in a pull-down assay while it also prevented the Aβ42-induced down-regulation of ABAD activity, as measured by levels of estradiol, a known hormone and product of ABAD activity. Furthermore, AG18051 is protective against Aβ42 toxicity, as measured by LDH release and MTT absorbance. Specifically, AG18051 reduced Aβ42-induced impairment of mitochondrial respiration and oxidative stress as shown by reduced ROS (reactive oxygen species) levels. Guided by our previous finding of shared aspects of the toxicity of Aβ and human amylin (HA), with the latter forming aggregates in Type 2 diabetes mellitus (T2DM) pancreas, we determined whether AG18051 would also confer protection from HA toxicity. We found that the inhibitor conferred only partial protection from HA toxicity indicating distinct pathomechanisms of the two amyloidogenic agents. Taken together, our results present the inhibition of ABAD by compounds such as AG18051 as a promising therapeutic strategy for the prevention and treatment of AD, and suggest levels of estradiol as a suitable read-out
“Fishing Na Everybody Business”: Women's Work and Gender Relations in Sierra Leone's Fisheries
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
Bi-allelic Loss-of-Function CACNA1B Mutations in Progressive Epilepsy-Dyskinesia.
The occurrence of non-epileptic hyperkinetic movements in the context of developmental epileptic encephalopathies is an increasingly recognized phenomenon. Identification of causative mutations provides an important insight into common pathogenic mechanisms that cause both seizures and abnormal motor control. We report bi-allelic loss-of-function CACNA1B variants in six children from three unrelated families whose affected members present with a complex and progressive neurological syndrome. All affected individuals presented with epileptic encephalopathy, severe neurodevelopmental delay (often with regression), and a hyperkinetic movement disorder. Additional neurological features included postnatal microcephaly and hypotonia. Five children died in childhood or adolescence (mean age of death: 9 years), mainly as a result of secondary respiratory complications. CACNA1B encodes the pore-forming subunit of the pre-synaptic neuronal voltage-gated calcium channel Cav2.2/N-type, crucial for SNARE-mediated neurotransmission, particularly in the early postnatal period. Bi-allelic loss-of-function variants in CACNA1B are predicted to cause disruption of Ca2+ influx, leading to impaired synaptic neurotransmission. The resultant effect on neuronal function is likely to be important in the development of involuntary movements and epilepsy. Overall, our findings provide further evidence for the key role of Cav2.2 in normal human neurodevelopment.MAK is funded by an NIHR Research Professorship and receives funding from the Wellcome Trust, Great Ormond Street Children's Hospital Charity, and Rosetrees Trust. E.M. received funding from the Rosetrees Trust (CD-A53) and Great Ormond Street Hospital Children's Charity. K.G. received funding from Temple Street Foundation. A.M. is funded by Great Ormond Street Hospital, the National Institute for Health Research (NIHR), and Biomedical Research Centre. F.L.R. and D.G. are funded by Cambridge Biomedical Research Centre. K.C. and A.S.J. are funded by NIHR Bioresource for Rare Diseases. The DDD Study presents independent research commissioned by the Health Innovation Challenge Fund (grant number HICF-1009-003), a parallel funding partnership between the Wellcome Trust and the Department of Health, and the Wellcome Trust Sanger Institute (grant number WT098051). We acknowledge support from the UK Department of Health via the NIHR comprehensive Biomedical Research Centre award to Guy's and St. Thomas' National Health Service (NHS) Foundation Trust in partnership with King's College London. This research was also supported by the NIHR Great Ormond Street Hospital Biomedical Research Centre. J.H.C. is in receipt of an NIHR Senior Investigator Award. The research team acknowledges the support of the NIHR through the Comprehensive Clinical Research Network. The views expressed are those of the author(s) and not necessarily those of the NHS, the NIHR, Department of Health, or Wellcome Trust. E.R.M. acknowledges support from NIHR Cambridge Biomedical Research Centre, an NIHR Senior Investigator Award, and the University of Cambridge has received salary support in respect of E.R.M. from the NHS in the East of England through the Clinical Academic Reserve. I.E.S. is supported by the National Health and Medical Research Council of Australia (Program Grant and Practitioner Fellowship)
North American Cornucopia
Many North American plants have characteristics that are especially promising for creating varieties needed to expand food production, and there are excellent prospects of generating new economically competitive crops from these natives. The inadequacy of current crops to meet the food demands of the world’s huge, growing population makes the potential of indigenous North American food plants even more significant. These plants can also generate crops that are more compatible with the ecology of the world, and many also have inherent health benefits. Presenting detailed scholarship, a thoroughly accessible style, and numerous entertaining anecdotes, North American Cornucopia: Top 100 Indigenous Food Plants is a full-color book dedicated to the most important 100 native food plants of North America north of Mexico that have achieved commercial success or have substantial market potential. The introductory chapter reviews the historical development of North American indigenous crops and factors bearing on their future economic success. The rest of the book consists of 100 chapters, each dedicated to a particular crop. The book employs a user-friendly chapter format that presents the material in sections offering in-depth coverage of each plant. The first section of each chapter provides information on the scientific and English names of the plants, followed by a section on the geography and ecology of the wild forms, accompanied by a map showing the North American distribution. A section entitled "Plant Portrait" comprises a basic description of the plant, its history, and its economic and social importance. This is followed by "Culinary Portrait," concerned with food uses and culinary vocabulary. The chapters then provide an analysis of the economic future of each crop, discuss notable and interesting scientific or technological observations and accomplishments, and present extensive references
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