Magnetospheric Response Times Following Southward IMF Turnings

We analyze the response times of various regions of the magnetosphere-ionosphere system to sudden southward turnings of the IMF. Our data set consists of 26 events during which the IMP BZ component was observed by WIND to change from a stea northward field to a southward field, which subsequently led to a substorm. The magnetospheric response to such IMF southward turnings is examined using data from the POLAR EFI experiment, the GOES 9 magnetometer, and ground magnetometers. The POLAR/EFI was used to investigate changes in the polar cap electric field which occurred in response to the changing interplanetary electric field, and these results are compared with response timings derived from high-latitude ground magnetometers. POLAR/EFI data show responses in the polar cap about 15 minutes after the arrival of the IMF change at the magnetopause. Auroral zone magnetograms and geosynchronous spacecraft measurements are utilized to evaluate the response timing within the closed field line region. In one event examined in detail, the start of a substorm growth phase was observed by GOES 9 in the midnight sector of geosynchronous orbit about two minutes before POLAR observed a response in the polar cap. Using superposed epoch analysis, we calculate typical response times in the polar cap, in the nightside plasma sheet, and in the ionosphere in order to discuss the various suggested mechanisms for information propagation from the subsolar magnetopause into the magnetosphere. We find that for the set of ten events for which the GOES 9 and the CANOPUS array are in the midnight sector, the field at geosynchronous as measured by GOES responds at or before the time of response in the polar cap as measured by POLAR, suggesting different methods of information propagation

Possible impacts of a future grand solar minimum on climate: Stratospheric and global circulation changes.

This is the final version of the article. It first appeared from Wiley via http://dx.doi.org/10.1002/2014JD022022A future decline in solar activity would not offset projected global warmingA future decline in solar activity could have larger regional effects in winterTop-down mechanism contributes to Northern Hemisphere regional response.LJG and ACM were supported by the National Centre for Atmospheric Science's Climate Directorate. ACM also acknowledges support from the ERC ACCI project no. 267760 and an AXA Postdoctoral Fellowship. SI and AAS were supported by the Joint DECC/Defra Met Office Hadley Centre Climate Programme (GA01101). LJG and JAA were supported by a grant from the National Environmental Research Council

Vascular changes in diabetic retinopathy-a longitudinal study in the Nile rat

Diabetic retinopathy is the most common microvascular complication of diabetes and is a major cause of blindness, but an understanding of the pathogenesis of the disease has been hampered by a lack of accurate animal models. Here, we explore the dynamics of retinal cellular changes in the Nile rat (Arvicanthis niloticus), a carbohydrate-sensitive model for type 2 diabetes. The early retinal changes in diabetic Nile rats included increased acellular capillaries and loss of pericytes that correlated linearly with the duration of diabetes. These vascular changes occurred in the presence of microglial infiltration but in the absence of retinal ganglion cell loss. After a prolonged duration of diabetes, the Nile rat also exhibits a spectrum of retinal lesions commonly seen in the human condition including vascular leakage, capillary non-perfusion, and neovascularization. Our longitudinal study documents a range and progression of retinal lesions in the diabetic Nile rat remarkably similar to those observed in human diabetic retinopathy, and suggests that this model will be valuable in identifying new therapeutic strategies

Mining and analysis of audiology data to find significant factors associated with tinnitus masker

Objectives: The objective of this research is to find the factors associated with tinnitus masker from the literature, and by using the large amount of audiology data available from a large NHS (National Health Services, UK) hearing aid clinic. The factors evaluated were hearing impairment, age, gender, hearing aid type, mould and clinical comments. Design: The research includes literature survey for factors associated with tinnitus masker, and performs the analysis of audiology data using statistical and data mining techniques. Setting: This research uses a large audiology data but it also faced the problem of limited data for tinnitus. Participants: It uses 1,316 records for tinnitus and other diagnoses, and 10,437 records of clinical comments from a hearing aid clinic. Primary and secondary outcome measures: The research is looking for variables associated with tinnitus masker, and in future, these variables can be combined into a single model to develop a decision support system to predict about tinnitus masker for a patient. Results: The results demonstrated that tinnitus maskers are more likely to be fit to individuals with milder forms of hearing loss, and the factors age, gender, type of hearing aid and mould were all found significantly associated with tinnitus masker. In particular, those patients having Age<=55 years were more likely to wear a tinnitus masker, as well as those with milder forms of hearing loss. ITE (in the ear) hearing aids were also found associated with tinnitus masker. A feedback on the results of association of mould with tinnitus masker from a professional audiologist of a large NHS (National Health Services, UK) was also taken to better understand them. The results were obtained with different accuracy for different techniques. For example, the chi-squared test results were obtained with 95% accuracy, for Support and Confidence only those results were retained which had more than 1% Support and 80% Confidence. Conclusions: The variables audiograms, age, gender, hearing aid type and mould were found associated with the choice of tinnitus masker in the literature and by using statistical and data mining techniques. The further work in this research would lead to the development of a decision support system for tinnitus masker with an explanation that how that decision was obtained

Light-Driven H2 Evolution and C═C or C═O Bond Hydrogenation by Shewanella oneidensis : A Versatile Strategy for Photocatalysis by Nonphotosynthetic Microorganisms

Photocatalytic chemical synthesis by coupling abiotic photosensitizers to purified enzymes provides an effective way to overcome the low conversion efficiencies of natural photosynthesis while exploiting the high catalytic rates and selectivity of enzymes as renewable, earth-abundant electrocatalysts. However, the selective synthesis of multiple products requires more versatile approaches and should avoid the time-consuming and costly processes of enzyme purification. Here we demonstrate a cell-based strategy supporting light-driven H2 evolution or the hydrogenation of C═C and C═O bonds in a nonphotosynthetic microorganism. Methylviologen shuttles photoenergized electrons from water-soluble photosensitizers to enzymes that catalyze H2 evolution and the reduction of fumarate, pyruvate, and CO2 in Shewanella oneidensis. The predominant reaction is selected by the experimental conditions, and the results allow rational development of cell-based strategies to harness nature’s intrinsic catalytic diversity for selective light-driven synthesis of a wide range of products

Global solar wind variations over the last four centuries

The most recent “grand minimum” of solar activity, the Maunder minimum (MM, 1650–1710), is of great interest both for understanding the solar dynamo and providing insight into possible future heliospheric conditions. Here, we use nearly 30 years of output from a data-constrained magnetohydrodynamic model of the solar corona to calibrate heliospheric reconstructions based solely on sunspot observations. Using these empirical relations, we produce the first quantitative estimate of global solar wind variations over the last 400 years. Relative to the modern era, the MM shows a factor 2 reduction in near-Earth heliospheric magnetic field strength and solar wind speed, and up to a factor 4 increase in solar wind Mach number. Thus solar wind energy input into the Earth’s magnetosphere was reduced, resulting in a more Jupiter-like system, in agreement with the dearth of auroral reports from the time. The global heliosphere was both smaller and more symmetric under MM conditions, which has implications for the interpretation of cosmogenic radionuclide data and resulting total solar irradiance estimates during grand minima

Preterm Birth in Caucasians Is Associated with Coagulation and Inflammation Pathway Gene Variants

Spontaneous preterm birth (<37 weeks gestation—PTB) occurs in ∼12% of pregnancies in the United States, and is the largest contributor to neonatal morbidity and mortality. PTB is a complex disease, potentially induced by several etiologic factors from multiple pathophysiologic pathways. To dissect the genetic risk factors of PTB a large-scale high-throughput candidate gene association study was performed examining 1536 SNP in 130 candidate genes from hypothesized PTB pathways. Maternal and fetal DNA from 370 US Caucasian birth-events (172 cases and 198 controls) was examined. Single locus, haplotype, and multi-locus association analyses were performed separately on maternal and fetal data. For maternal data the strongest associations were found in genes in the complement-coagulation pathway related to decidual hemorrhage in PTB. In this pathway 3 of 6 genes examined had SNPs significantly associated with PTB. These include factor V (FV) that was previously associated with PTB, factor VII (FVII), and tissue plasminogen activator (tPA). The single strongest effect was observed in tPA marker rs879293 with a significant allelic (p = 2.30×10−3) and genotypic association (p = 2.0×10−6) with PTB. The odds ratio (OR) for this SNP was 2.80 [CI 1.77–4.44] for a recessive model. Given that 6 of 8 markers in tPA were statistically significant, sliding window haplotype analyses were performed and revealed an associating 4 marker haplotype in tPA (p = 6.00×10−3). The single strongest effect in fetal DNA was observed in the inflammatory pathway at rs17121510 in the interleukin-10 receptor antagonist (IL-10RA) gene for allele (p = 0.01) and genotype (p = 3.34×10−4). The OR for the IL-10RA genotypic additive model was 1.92 [CI 1.15–3.19] (p = 2.00×10−3). Finally, exploratory multi-locus analyses in the complement and coagulation pathway were performed and revealed a potentially significant interaction between a marker in FV (rs2187952) and FVII (rs3211719) (p<0.001). These results support a role for genes in both the coagulation and inflammation pathways, and potentially different maternal and fetal genetic risks for PTB

The Prevalence of Previously Undiagnosed Leprosy in the General Population of Northwest Bangladesh

In order to estimate the level of leprosy in an area with many leprosy patients, we determined the prevalence of previously undiagnosed leprosy in the general population and compared this with the registered (or known) number of leprosy patients. We also compared it with the known prevalence of leprosy in contacts of leprosy patients. We examined 20 randomly selected geographical clusters of 1,000 persons each in two districts of Bangladesh, with over 4 million population. Physical examination was performed on all individuals. The number of newly found leprosy cases among 17,862 people above 5 years of age from the clusters was 27, giving a rate of previously undiagnosed leprosy of 15.1 per 10,000. This rate is six times higher than the registered prevalence, but three times lower than the rate in the most distant subgroup of contacts (neighbour of neighbour and social contacts) of leprosy patients in the same area. We conclude that in areas where leprosy is common, it may be preferable to do full village or neighbourhood surveys when a new leprosy patient is found, rather than to limit contact surveys to close contacts only, such as household members

Four priority areas to advance invasion science in the face of rapid environmental change

Unprecedented rates of introduction and spread of non-native species pose burgeoning challenges to biodiversity, natural resource management, regional economies, and human health. Current biosecurity efforts are failing to keep pace with globalization, revealing critical gaps in our understanding and response to invasions. Here, we identify four priority areas to advance invasion science in the face of rapid global environmental change. First, invasion science should strive to develop a more comprehensive framework for predicting how the behavior, abundance, and interspecific interactions of non-native species vary in relation to conditions in receiving environments and how these factors govern the ecological impacts of invasion. A second priority is to understand the potential synergistic effects of multiple co-occurring stressors— particularly involving climate change—on the establishment and impact of non-native species. Climate adaptation and mitigation strategies will need to consider the possible consequences of promoting non-native species, and appropriate management responses to non-native species will need to be developed. The third priority is to address the taxonomic impediment. The ability to detect and evaluate invasion risks is compromised by a growing deficit in taxonomic expertise, which cannot be adequately compensated by new molecular technologies alone. Management of biosecurity risks will become increasingly challenging unless academia, industry, and governments train and employ new personnel in taxonomy and systematics. Fourth, we recommend that internationally cooperative biosecurity strategies consider the bridgehead effects of global dispersal networks, in which organisms tend to invade new regions from locations where they have already established. Cooperation among countries to eradicate or control species established in bridgehead regions should yield greater benefit than independent attempts by individual countries to exclude these species from arriving and establishing