Search

The bacterial plant pathogen Xylella fastidiosa causes disease in several globally important crops. However, some cultivars harbour reduced bacterial loads and express few symptoms. Evidence considering plant species in isolation suggests xylem structure influences cultivar susceptibility to X. fastidiosa. We test this theory more broadly by analysing high‐resolution synchrotron X‐ray computed tomography of healthy and infected plant vasculature from two taxonomic groups containing susceptible and resistant varieties: two citrus cultivars (sweet orange cv. Pera, tangor cv. Murcott) and two olive cultivars (Koroneiki, Leccino). Results found the susceptible plants had more vessels than resistant ones, which could promote within‐host pathogen spread. However, features associated with resistance were not shared by citrus and olive. While xylem vessels in resistant citrus stems had comparable diameters to those in susceptible plants, resistant olives had narrower vessels that could limit biofilm spread. And while differences among olive cultivars were not detected, results suggest greater vascular connectivity in resistant compared to susceptible citrus plants. We hypothesize that this provides alternate flow paths for sustaining hydraulic functionality under infection. In summary, this work elucidates different physiological resistance mechanisms between two taxonomic groups, while supporting the existence of an intertaxonomical metric that could speed up the identification of candidate‐resistant plants. [ABSTRACT FROM AUTHOR]

Objective: Focal epilepsy is common in low‐ and middle‐income countries. The frequency and nature of possible underlying structural brain abnormalities have, however, not been fully assessed. Methods: We evaluated the possible structural causes of epilepsy in 331 people with epilepsy (240 from Kenya and 91 from South Africa) identified from community surveys of active convulsive epilepsy. Magnetic resonance imaging (MRI) scans were acquired on 1.5‐Tesla scanners to determine the frequency and nature of any underlying lesions. We estimated the prevalence of these abnormalities using Bayesian priors (from an earlier pilot study) and observed data (from this study). We used a mixed‐effect modified Poisson regression approach with the site as a random effect to determine the clinical features associated with neuropathology. Results: MRI abnormalities were found in 140 of 240 (modeled prevalence = 59%, 95% confidence interval [CI]: 53%–64%) of people with epilepsy in Kenya, and in 62 of 91 (modeled prevalence = 65%, 95% CI: 57%–73%) in South Africa, with a pooled modeled prevalence of 61% (95% CI: 56%–66%). Abnormalities were common in those with a history of adverse perinatal events (15/23 [65%, 95% CI: 43%–84%]), exposure to parasitic infections (83/120 [69%, 95% CI: 60%–77%]) and focal electroencephalographic features (97/142 [68%, 95% CI: 60%–76%]), but less frequent in individuals with generalized electroencephalographic features (44/99 [44%, 95% CI: 34%–55%]). Most abnormalities were potentially epileptogenic (167/202, 82%), of which mesial temporal sclerosis (43%) and gliosis (34%) were the most frequent. Abnormalities were associated with co‐occurrence of generalized non‐convulsive seizures (relative risk [RR] = 1.12, 95% CI: 1.04–1.25), lack of family history of seizures (RR = 0.91, 0.86–0.96), convulsive status epilepticus (RR = 1.14, 1.08–1.21), frequent seizures (RR = 1.12, 1.04–1.20), and reported use of anti‐seizure medication (RR = 1.22, 1.18–1.26). Significance: MRI identified pathologies are common in people with epilepsy in Kenya and South Africa. Mesial temporal sclerosis, the most common abnormality, may be amenable to surgical correction. MRI may have a diagnostic value in rural Africa, but future longitudinal studies should examine the prognostic role. [ABSTRACT FROM AUTHOR]

Xylella fastidiosa is a xylem‐limited plant pathogen infecting many crops globally and is the cause of the recent olive disease epidemic in Italy. One strategy proposed to mitigate losses is to replant susceptible crops with resistant varieties. Several genetic, biochemical and biophysical traits are associated to X. fastidiosa disease resistance. However, mechanisms underpinning resistance are poorly understood. We hypothesize that the susceptibility of olive cultivars to infection will correlate to xylem vessel diameters, with narrower vessels being resistant to air embolisms and having slower flow rates limiting pathogen spread. To test this, we scanned stems from four olive cultivars of varying susceptibility to X. fastidiosa using X‐ray computed tomography. Scans were processed by a bespoke methodology that segmented vessels, facilitating diameter measurements. Though significant differences were not found comparing stem‐average vessel section diameters among cultivars, they were found when comparing diameter distributions. Moreover, the measurements indicated that although vessel diameter distributions may play a role regarding the resistance of Leccino, it is unlikely they do for FS17. Considering Young–Laplace and Hagen–Poiseuille equations, we inferred differences in embolism susceptibility and hydraulic conductivity of the vasculature. Our results suggest susceptible cultivars, having a greater proportion of larger vessels, are more vulnerable to air embolisms. In addition, results suggest that under certain pressure conditions, functional vasculature in susceptible cultivars could be subject to greater stresses than in resistant cultivars. These results support investigation into xylem morphological screening to help inform olive replanting. Furthermore, our framework could test the relevance of xylem geometry to disease resistance in other crops. [ABSTRACT FROM AUTHOR]

Predicting complex species‐environment interactions is crucial for guiding conservation and mitigation strategies in a dynamically changing world. Phenotypic plasticity is a mechanism of trait variation that determines how individuals and populations adapt to changing and novel environments. For individuals, the effects of phenotypic plasticity can be quantified by measuring environment–trait relationships, but it is often difficult to predict how phenotypic plasticity affects populations. The assumption that environment–trait relationships validated for individuals indicate how populations respond to environmental change is commonly made without sufficient justification. Here we derive a novel general mathematical framework linking trait variation due to phenotypic plasticity to population dynamics. Applying the framework to the classical example of Nicholson's blowflies, we show how seemingly sensible predictions made from environment–trait relationships do not generalise to population responses. As a consequence, trait‐based analyses that do not incorporate population feedbacks risk mischaracterising the effect of environmental change on populations. [ABSTRACT FROM AUTHOR]

The idea of a 'third space' located between academic and professional domains has proven useful in exploring changing academic and professional roles in higher education, including in online learning. However, the role of technology in accounts of third space activity remains under‐explored. Drawing on research into the introduction of Massive Open Online Courses (MOOCs) at three UK higher education institutions, it is argued that both social and technical factors must be considered to understand, plan for and manage the third space roles and structures which emerge in such initiatives. This study focuses on learning designers, confirming that they act as third space 'blended professionals' in the somewhat distinctive case of MOOC development. However, it also proposes the concept of a socio‐technical third space in which blended professionals act as hubs in a metaphorical network of activity, using social and technical means to shape their own roles and those of others. [ABSTRACT FROM AUTHOR]

Background: Early vascular complications following pancreatic transplantation are not uncommon (3%–8%). Typically, cross‐sectional imaging is requested in response to clinical change. We instituted a change in protocol to request imaging pre‐emptively to identify patients with thrombotic complications. Methods: In 2013, protocol computer tomography angiography (CTA) at days 3–5 and day 10 following pancreas transplantation was introduced. A retrospective analysis of all pancreas transplants performed at our institution from January 2001 to May 2019 was undertaken. Results: A total of 115 patients received pancreas transplants during this time period. A total of 78 received pancreas transplant without routine CTA and 37 patients with the new protocol. Following the change in protocol, we detected a high number of subclinical thromboses (41.7%). There was a significant decrease in invasive intervention for thrombosis (78.6% before vs 30.8% after, p =.02), and graft survival was significantly higher (61.5% before vs 86.1% after, p =.04). There was also a significant reduction in the number of graft failures (all‐cause) where thrombosis was present (23.4% before vs 5.6% after, p =.02). Patient survival was unaffected (p =.48). Conclusions: Implementation of early protocol CTA identifies a large number of patients with subclinical graft thromboses that are more amenable to conservative management and significantly reduces the requirement for invasive intervention. [ABSTRACT FROM AUTHOR]

Xylella fastidiosa is an important insect‐vectored bacterial plant pathogen with a wide host range, causing significant economic impact in the agricultural and horticultural industries. Once restricted to the Americas, severe European outbreaks have been discovered recently in Italy, Spain, France, and Portugal. The Italian outbreak, detected in Puglia in 2013, has spread over 100 km, killing millions of olive trees, and is still expanding. To date, quantified assessment of important epidemiological parameters useful for risk assessment and management, such as transmission rates, symptomless periods, and time to death in field populations, has been lacking. This is due to the emergent and novel nature of the outbreak and length of time needed to monitor the course of disease progression. To address this, we developed a Bayesian method to infer epidemiological parameters by fitting and comparing compartmental epidemiological models to short snapshots of disease progression observed in multiple field plots. We estimated that each infected tree with symptoms is able to infect around 19 trees per year (95% credible range 14–26). The symptomless stage was estimated to have low to negligible infectivity and to last an average of approximately 1.2 years (95% credible range 1.0–1.3 years). Tree desiccation was estimated to occur approximately 4.3 years (95% credible range 4.0–4.6 years) after symptom appearance. However, we were unable to estimate the infectiousness of desiccated trees from the data. Our method could be used to make early estimates of epidemiological parameters in other emerging disease outbreaks where symptom expression is slow. [ABSTRACT FROM AUTHOR]

Sudden cardiac death is a significant cause of mortality in adults with congenital heart disease (CHD). The Cook County Medical Examiner's Office database was queried for cases of CHD as a cause of death in the period between July 2008 and April 2019. Twenty‐two cases were identified, including 11 decedents with simple defects and 10 decedents with complex defects. All of the subjects were in apparent good health at the time of death. In the absence of other obvious causes of death, simple defects were considered cases of sudden cardiac death. Significant cardiac morphological changes were common in complex defects. While 16 cases had known, diagnosed/treated CHD, 5 cases had no diagnosis prior to autopsy. In these cases, the ability to recognize CHD (sometimes subtle) helped in determining the causes of death. Therefore, forensic pathologists must be able to properly recognize various forms of CHD and request consultations, when needed. [ABSTRACT FROM AUTHOR]

The National Institute on Drug Abuse has observed an increase in fentanyl deaths in the United States. One epidemic related to the abuse of fentanyl happened in Cook County in 2005–2007 (350 deaths). Another outbreak of fentanyl deaths occurred in 2015–2017 in the same area. The database of the Cook County Medical Examiner's Office was searched for cases of fentanyl deaths between 2015 and 2017: 1244 deaths were found. A comparison was performed with the previous data: an increase in the number of females was observed in 2015–2017. Also, in 2005–2007, the majority of deaths occurred among African American, while in 2015–2017, Caucasians were more involved. Within our population, some drug combinations were more common in specific demographic subgroups (male/females; Caucasian/African American; and certain age groups). The epidemiology and the most significant drug associations found at the toxicology are discussed, highlighting the usefulness of the knowledge about this outbreak for public health. [ABSTRACT FROM AUTHOR]

Firms simultaneously face the need to cooperate with and control an alliance partner. To complement the transaction cost perspective's emphasis on the need to control and limit opportunistic behavior, we examine the sources and impact of the cooperation costs incurred in order to work with a partner. We propose that these costs increase with greater joint task complexity and interpartner diversity, and perceptions of equitable behavior affect the perceptions of these costs. Hypotheses derived from the framework are tested in a sample of 231 contractual alliances between architects and general contractors in the Hong Kong construction industry. We find that both cooperation costs and transaction costs affect the level of time and effort a manager expends on an alliance, supporting our fundamental proposition that the costs of cooperation and control are conceptually and empirically distinct. We argue that cooperation costs should be incorporated into studies that compare the choice of alternative partners and alliance structures, as well as among the broader categories of market, hierarchy, and hybrid governance forms. [ABSTRACT FROM AUTHOR]

Objective: Appalachia—historically a culturally and politically unique region of the United States—has been effectively ignored by contemporary political scientists. Using a unique measure of Appalachian residence, this article analyzes racial attitudes, religion, and Appalachian opposition to the 2008 presidential candidacy of Barack Obama. Methods: I use regression analysis to assess the extent to which Appalachian residents differ in their levels of perceived racial favoritism, identification as born‐again Christians, and frequency of church attendance, as well as whether these variables can mediate the seeming regional effect of Appalachia in a standard vote choice model. Results: I first demonstrate higher levels of perceived racial favoritism and, especially, higher levels of a particular type of religiosity in the region. I then assess whether these measures can mediate Appalachian distinctiveness in presidential vote choice. When perceived racial favoritism, church attendance, and born‐again Christian status are controlled for in regression models, Appalachian regional opposition to the 2008 Obama candidacy disappears statistically. Conclusion: While race and religion both "matter," I find it is religion that seems to matter more in explaining Appalachian distinctiveness, particularly relative to traditional southern distinctiveness. This provides a new vantage point from which to assess southern politics debates about subregional variation and the relative roles of race and religion, as well as sets the foundation for further analyses of Appalachia and American politics. [ABSTRACT FROM AUTHOR]

BioGears is an open‐source, lumped parameter, full‐body human physiology engine. Its purpose is to provide realistic and comprehensive simulations for medical training, research, and education. BioGears incorporates a physiologically based pharmacokinetic/pharmacodynamic (PK/PD) model that is designed to be applicable to a diversity of drug classes and patients and is extensible to future drugs. In addition, BioGears also supports drug interactions with various patient insults and interventions allowing for a realistic research framework and accurate dose‐patient responses. This tutorial will demonstrate how the generic BioGears PK/PD model can be extended to a new substance for prediction of drug administration outcomes. [ABSTRACT FROM AUTHOR]

Objective: Asthmatic children who develop obesity through adolescence have poorer disease outcomes compared with those who do not. This study aimed to characterize the biology of childhood asthma complicated by adult obesity.Methods: Gene expression networks are powerful statistical tools for characterizing human disease that leverage the putative coregulatory relationships of genes to infer relevant biological pathways. Weighted gene coexpression network analysis of gene expression data was performed in whole blood from 514 adult asthmatic subjects. Then, module preservation and association replication analyses were performed in 418 subjects from two independent asthma cohorts (one pediatric and one adult).Results: A multivariate model was identified in which three gene coexpression network modules were associated with incident obesity in the discovery cohort (each P < 0.05). Two module memberships were enriched for genes in pathways related to platelets, integrins, extracellular matrix, smooth muscle, NF-κB signaling, and Hedgehog signaling. The network structures of each of the obesity modules were significantly preserved in both replication cohorts (permutation P = 9.999E-05). The corresponding module gene sets were significantly enriched for differential expression in subjects with obesity in both replication cohorts (each P < 0.05).Conclusions: The gene coexpression network profiles thus implicate multiple interrelated pathways in the biology of an important endotype of asthma with obesity. [ABSTRACT FROM AUTHOR]

Despite advances in the diagnosis and treatment of congenital heart defects (CHDs), these defects are still an important cause of sudden, unexpected death in young children. This retrospective study identified 64 cases of CHDs presenting as a cause of sudden, unexpected death in a busy, urban Medical Examiner's Office pediatric population between 2006 and 2016. The majority of cases (52 of 64, 81%) were infants. Interestingly, 52% of cases were undiagnosed prior to autopsy. Ventricular septal defects and atrioventricular septal defects were the most common simple (14%) and complex (17%) malformations observed, respectively. In many cases, there were coexistent simple and/or complex defects. Most of the cases diagnosed with CHD prior to autopsy (48%) had undergone some type of surgical repair. This study highlights the importance of considering undiagnosed CHDs as a cause of sudden, unexpected death, particularly in young children. [ABSTRACT FROM AUTHOR]

Abstract: To address the lack of information about the shape and extent of real dispersal kernels, Bullock et al. (Journal of Ecology 105:6‐19, 2017) synthesised empirical information on seed dispersal distances. Testing the fit of a variety of probability density functions, they found no function was the best‐fitting for all datasets but some outperformed others. Cousens et al. (Journal of Ecology, 2017) focus on the specific finding of the generally poor fit of the WALD function to wind dispersal data and use this to argue that mechanistically derived functions would not be expected to fit data particularly well. We agree in part with this argument and discuss the issues that may lead to poor fit, including the simplifying assumptions of the WALD and the complexity of the dispersal process. We explain the fundamental linkage between the mechanistic form of the WALD and the derived function used for fitting to data. We demonstrate, however, that the logic that a mechanistically based function could fit to data is valid, under the hypothesis that it encompasses the key processes determining the dispersal kernel. This argument is supported by the facts that: (1) our analyses and others have shown the WALD performs well in a number of cases; and (2) the WALD is the best‐fitting function for an example in which we simulate dispersal data using a realistic representation of variability in the wind dispersal process. Synthesis. While there are reasons that mechanistically derived functions may not fit well to empirical data, they do in some empirical and simulated cases and this suggests they can capture the dispersal behaviour of real systems. Mechanistic functions should be explored along with other more general functions when describing empirical data to investigate their simplifying assumptions and to add to our arsenal of functions for analysing dispersal data. Analyses using these functions are critical if we are to move from simply describing the system in which the data were gathered to gaining more general insights into dispersal and predicting its consequences. [ABSTRACT FROM AUTHOR]

Sudden unexpected death of an individual with epilepsy can pose a challenge to death investigators, as most deaths are unwitnessed, and the individual is commonly found dead in bed. Anatomic findings (eg, tongue/lip bite) are commonly absent and of varying specificity, thereby limiting the evidence to implicate epilepsy as a cause of or contributor to death. Thus it is likely that death certificates significantly underrepresent the true number of deaths in which epilepsy was a factor. To address this, members of the National Association of Medical Examiners, North American SUDEP Registry, Epilepsy Foundation SUDEP Institute, American Epilepsy Society, and the Centers for Disease Control and Prevention constituted an expert panel to generate evidence-based recommendations for the practice of death investigation and autopsy, toxicological analysis, interpretation of autopsy and toxicology findings, and death certification to improve the precision of death certificate data available for public health surveillance of epilepsy-related deaths. The recommendations provided in this paper are intended to assist medical examiners, coroners, and death investigators when a sudden unexpected death in a person with epilepsy is encountered. [ABSTRACT FROM AUTHOR]

Understanding the ability of plants to spread is important for assessing conservation strategies, landscape dynamics, invasiveness and ability to cope with climate change. While long-distance seed dispersal is often viewed as a key process in population spread, the importance of inter-specific variation in demography is less explored. Indeed, the relative importance of demography vs seed dispersal in determining population spread is still little understood. We modelled species' potential for population spread in terms of annual migration rates for a set of species inhabiting dry grasslands of central Europe. Simultaneously, we estimated the importance of demographic (population growth rate) versus long-distance dispersal (99th percentile dispersal distance) characteristics for among-species differences in modelled population spread. In addition, we assessed how well simple proxy measures related to demography (the number and survival of seedlings, the survival of flowering individuals) and dispersal (plant height, terminal velocity and wind speed during dispersal) predicted modelled spread rates. We found that species' demographic rates were the more powerful predictors of species' modelled potential to spread than dispersal. Furthermore, our simple proxies were correlated with modelled species spread rates and together their predictive power was high. Our findings highlight that for understanding variation among species in their potential for population spread, detailed information on local demography and dispersal might not always be necessary. Simple proxies or assumptions that are based primarily on species demography could be sufficient. [ABSTRACT FROM AUTHOR]

In their recent paper, Staver and Hansen ( Global Ecology and Biogeography, 2015, 24, 985-987) refute the case made by Hanan et al. ( Global Ecology and Biogeography, 2014, 23, 259-263) that the use of classification and regression trees (CARTs) to predict tree cover from remotely sensed imagery (MODIS VCF) inherently introduces biases, thus making the resulting tree cover unsuitable for showing alternative stable states through tree cover frequency distribution analyses. Here we provide a new and equally fundamental argument for why the published frequency distributions should not be used for such purposes. We show that the practice of pre-average binning of tree cover values used to derive cover values to train the CART model will also introduce errors in the frequency distributions of the final product. We demonstrate that the frequency minima found at tree covers of 8-18%, 33-45% and 55-75% can be attributed to numerical biases introduced when training samples are derived from landscapes containing asymmetric tree cover distributions and/or a tree cover gradient. So it is highly likely that the CART, used to produce MODIS VCF, delivers tree cover frequency distributions that do not reflect the real world situation. [ABSTRACT FROM AUTHOR]

Simulating spatially explicit population models to predict population spread allows environmental managers to make better-informed decisions. Accurate simulation requires high spatial resolution, which, using existing techniques, can require prohibitively large amounts of computational resources (RAM, CPU, etc)., We developed and implemented a novel algorithm for the simulation of integro-difference equations (IDEs) modelling population spread, including stage structure, which uses adaptive mesh refinement., We measured the accuracy of the adaptive algorithm by comparing the results of simulations using the adaptive and a standard non-adaptive algorithm. The relative error of the population's spatial extent was low (<0·05) for a range of parameter values. Comparing efficiency, we found that our algorithm used up to 10 times less CPU time and RAM than the non-adaptive algorithm., Our approach provides large improvements in efficiency without significant loss of accuracy, so it enables faster simulation of IDEs and simulation at scales and at resolutions that have not been previously feasible. As an example, we simulate the spread of a hypothetical species over the UK at a resolution of 25 m. We provide our implementation of the algorithm as a user-friendly executable application. [ABSTRACT FROM AUTHOR]

Dispersal is fundamental to ecological processes at all scales and levels of organization, but progress is limited by a lack of information about the general shape and form of plant dispersal kernels. We addressed this gap by synthesizing empirical data describing seed dispersal and fitting general dispersal kernels representing major plant types and dispersal modes., A comprehensive literature search resulted in 107 papers describing 168 dispersal kernels for 144 vascular plant species. The data covered 63 families, all the continents except Antarctica, and the broad vegetation types of forest, grassland, shrubland and more open habitats (e.g. deserts). We classified kernels in terms of dispersal mode (ant, ballistic, rodent, vertebrates other than rodents, vehicle or wind), plant growth form (climber, graminoid, herb, shrub or tree), seed mass and plant height., We fitted 11 widely used probability density functions to each of the 168 data sets to provide a statistical description of the dispersal kernel. The exponential power (ExP) and log-sech (LogS) functions performed best. Other 2-parameter functions varied in performance. For example, the log-normal and Weibull performed poorly, while the 2Dt and power law performed moderately well. Of the single-parameter functions, the Gaussian performed very poorly, while the exponential performed better. No function was among the best-fitting for all data sets., For 10 plant growth form/dispersal mode combinations for which we had >3 data sets, we fitted ExP and LogS functions across multiple data sets to provide generalized dispersal kernels. We also fitted these functions to subdivisions of these growth form/dispersal mode combinations in terms of seed mass (for animal-dispersed seeds) or plant height (wind-dispersed) classes. These functions provided generally good fits to the grouped data sets, despite variation in empirical methods, local conditions, vegetation type and the exact dispersal process., Synthesis. We synthesize the rich empirical information on seed dispersal distances to provide standardized dispersal kernels for 168 case studies and generalized kernels for plant growth form/dispersal mode combinations. Potential uses include the following: (i) choosing appropriate dispersal functions in mathematical models; (ii) selecting informative dispersal kernels for one's empirical study system; and (iii) using representative dispersal kernels in cross-taxon comparative studies. [ABSTRACT FROM AUTHOR]

Estimating population spread rates across multiple species is vital for projecting biodiversity responses to climate change. A major challenge is to parameterise spread models for many species. We introduce an approach that addresses this challenge, coupling a trait-based analysis with spatial population modelling to project spread rates for 15 000 virtual mammals with life histories that reflect those seen in the real world. Covariances among life-history traits are estimated from an extensive terrestrial mammal data set using Bayesian inference. We elucidate the relative roles of different life-history traits in driving modelled spread rates, demonstrating that any one alone will be a poor predictor. We also estimate that around 30% of mammal species have potential spread rates slower than the global mean velocity of climate change. This novel trait-space-demographic modelling approach has broad applicability for tackling many key ecological questions for which we have the models but are hindered by data availability. [ABSTRACT FROM AUTHOR]

Purpose To explore the use and reproducibility of magnetic resonance-derived myocardial T1 mapping in patients with iron overload. Materials and Methods The research received ethics committee approval and all patients provided written informed consent. This was a prospective study of 88 patients and 67 healthy volunteers. Thirty-five patients underwent repeat scanning for reproducibility. T1 mapping used the shortened modified Look-Locker inversion recovery sequence (ShMOLLI) with a second, confirmatory MOLLI sequence in the reproducibility group. T2* was performed using a commercially available sequence. The analysis of the T2* interstudy reproducibility data was performed by two different research groups using two different methods. Results Myocardial T1 was lower in patients than healthy volunteers (836 ± 138 msec vs. 968 ± 32 msec, P < 0.0001). Myocardial T1 correlated with T2* (R = 0.79, P < 0.0001). No patient with low T2* had normal T1, but 32% ( n = 28) of cases characterized by a normal T2* had low myocardial T1. Interstudy reproducibility of either T1 sequence was significantly better than T2*, with the results suggesting that the use of T1 in clinical trials could decrease potential sample sizes by 7-fold. Conclusion Myocardial T1 mapping is an alternative method for cardiac iron quantification. T1 mapping shows the potential for improved detection of mild iron loading. The superior reproducibility of T1 has potential implications for clinical trial design and therapeutic monitoring. J. Magn. Reson. Imaging 2015;41:1505-1511. © 2014 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Understanding how species' traits relate to their status (e.g. invasiveness or rarity) is important because it can help to efficiently focus conservation and management effort and infer mechanisms affecting plant status. This is particularly important for invasiveness, in which proactive action is needed to restrict the establishment of potentially invasive plants., We tested the ability of genome size ( DNA 1 C-values) to explain invasiveness and compared it with cytogenetic traits (chromosome number and ploidy level). We considered 890 species from 62 genera, from across the angiosperm phylogeny and distributed from tropical to boreal latitudes., We show that invasiveness was negatively related to genome size and positively related to chromosome number (and ploidy level), yet there was a positive relationship between genome size and chromosome number; that is, our result was not caused by collinearity between the traits. Including both traits in explanatory models greatly increased the explanatory power of each., This demonstrates the potential unifying role that genome size, chromosome number and ploidy have as species' traits, despite the diverse impacts they have on plant physiology. It provides support for the continued cataloguing of cytogenetic traits and genome size of the world's flora. [ABSTRACT FROM AUTHOR]

Purpose Epilepsy is common in sub- Saharan Africa ( SSA), but the clinical features and consequences are poorly characterized. Most studies are hospital-based, and few studies have compared different ecological sites in SSA. We described active convulsive epilepsy ( ACE) identified in cross-sectional community-based surveys in SSA, to understand the proximate causes, features, and consequences. Methods We performed a detailed clinical and neurophysiologic description of ACE cases identified from a community survey of 584,586 people using medical history, neurologic examination, and electroencephalography ( EEG) data from five sites in Africa: South Africa; Tanzania; Uganda; Kenya; and Ghana. The cases were examined by clinicians to discover risk factors, clinical features, and consequences of epilepsy. We used logistic regression to determine the epilepsy factors associated with medical comorbidities. Key Findings Half (51%) of the 2,170 people with ACE were children and 69% of seizures began in childhood. Focal features ( EEG, seizure types, and neurologic deficits) were present in 58% of ACE cases, and these varied significantly with site. Status epilepticus occurred in 25% of people with ACE. Only 36% received antiepileptic drugs (phenobarbital was the most common drug [95%]), and the proportion varied significantly with the site. Proximate causes of ACE were adverse perinatal events (11%) for onset of seizures before 18 years; and acute encephalopathy (10%) and head injury prior to seizure onset (3%). Important comorbidities were malnutrition (15%), cognitive impairment (23%), and neurologic deficits (15%). The consequences of ACE were burns (16%), head injuries (postseizure) (1%), lack of education (43%), and being unmarried (67%) or unemployed (57%) in adults, all significantly more common than in those without epilepsy. Significance There were significant differences in the comorbidities across sites. Focal features are common in ACE, suggesting identifiable and preventable causes. Malnutrition and cognitive and neurologic deficits are common in people with ACE and should be integrated into the management of epilepsy in this region. Consequences of epilepsy such as burns, lack of education, poor marriage prospects, and unemployment need to be addressed. [ABSTRACT FROM AUTHOR]

Animal welfare is not currently regulated by a single, comprehensive international law instrument. This article considers prevailing frameworks in international law that address animal welfare in some way, but by themselves do not meet the hallmarks of an effective global protection regime, including comprehensiveness and enforceability. Emerging frameworks that might fill the gap in global animal welfare protection include a universal declaration on animal welfare, the entrenchment of World Organisation for Animal Health ( OIE) animal health standards and an international convention for the protection of animal welfare. While the prospects of any of these models succeeding in the short term are uncertain at best, the challenge now is to think carefully about what legal form an international framework for animal protection might take. [ABSTRACT FROM AUTHOR]

Summary 1. Climate change impacts on habitat suitability and demography are often studied, but direct effects on plant dispersal are rarely considered. To address this we analysed climate model projections of future wind speeds and modelled their possible impacts on dispersal and spread of wind-dispersed plants. 2. Projections for 17 Global Climate Models and three emission scenarios suggested great uncertainty about wind speeds in southern England by the period 2070-99. Projections ranged from −90% to +100% change in the mean wind speed, although the average projection was for large falls in both summer and winter wind speeds. 3. Using a novel method for converting projected changes in mean wind speed to new seasonal wind speed distributions, we parameterized a mechanistic model of seed dispersal by wind using baseline and changes in mean wind speed from −80% to +80%. 4. The mechanistic seed dispersal model was combined with demographic data in an analytical model of plant spread. This was carried out for three British native and three non-native species, which represented a range of life-forms. 5. Dispersal kernels and population spread rates were affected disproportionately by changes in wind speed, demonstrating nonlinear propagation of uncertainty in wind speed projections through to modelled plant spread rates. 6. Sensitivity analyses showed differences among the plant species in which demographic transitions were most important in determining spread rates. By contrast, sensitivity of spread rates to dispersal parameters showed great consistency among species, with seed release height being more important than seed terminal velocity. 7. Synthesis. Plant populations will need to shift their geographic ranges to keep pace with climate change-driven habitat loss. This study shows that climate change may affect that ability by decreasing the dispersal distances of wind-dispersed plants and thus their potential spread rates. However, the modelling approach presented here illustrates that uncertainty in climate models leads to an even greater uncertainty about how dispersal and spread will change in future climates. Caution should therefore be exercised in making predictions as to how fast plant species may spread in response to climate change. [ABSTRACT FROM AUTHOR]

The development of transgenic technologies, coupled with sterile insect techniques (SIT), is being explored in relation to new approaches for the biological control of insect pests. Recent studies have shown that there are often fitness costs associated with transgenic insect strains, but the impact of these costs on their potential use in pest control is poorly understood. In this paper, we explore the impact of an insect fitness cost on two control strategies (classical SIT and transgenic late-acting bisex lethality) using a stage-structured mathematical model, which is parameterized for the mosquito Aedes aegypti. Counter to the majority of studies, we use realistic pulsed release strategies and incorporate a fitness cost, which is manifested as a reduction in male mating competitiveness. For both models we show that the level of control of a pest mosquito population is highly sensitive to the rate at which the transgenic or sterile males are released. Population control is more effective when smaller numbers of sterile/transgenic males are released more frequently than larger and less frequent releases. If the wild-type mosquito population exhibits cycles of peaks and troughs in abundance, as is the case for many insect species, then high frequency releases of transgenic males not only reduce mosquito abundance, but they may dampen future pest outbreaks, whereas the use of SIT alone may have an adverse effect, causing an increase in mosquito abundance. Additionally, the timing of sterile/transgenic male release during the mosquito population cycle is critical in reducing pest outbreak levels. In all cases, the reduced fitness of the sterile/transgenic males causes reductions in control, thus requiring more frequent or greater magnitude releases. Synthesis and applications. The sterile insect technique is considered to be a valuable non-chemical tool for pest management. With the potential application of recent genetic developments to enhance the technique, it is becoming increasingly important to consider the wider ecological implications of this biological control strategy. Predicting the most efficient release strategies will be important in combating pest and vector insects as well as for limiting potential broader ecological effects. Although the focus of our models are based on the mosquito, A. aegypti, which can spread yellow fever, dengue fever and Chikungunya disease, our modelling approach and results can be applied more broadly to other species. [ABSTRACT FROM AUTHOR]

Purpose: To investigate the diagnostic performance of diffusion-weighted imaging (DWI) for mammographically and clinically occult breast lesions. Materials and Methods: The study included 91 women with 118 breast lesions (91 benign, 12 ductal carcinoma in situ [DCIS], 15 invasive carcinoma) initially detected on dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) and assigned BI-RADS category 3, 4, or 5. DWI was acquired with b = 0 and 600 s/mm2. Lesion visibility was assessed on DWI. Apparent diffusion coefficient (ADC) values were compared between malignancies, benign lesions, and normal (no abnormal enhancement on DCE-MRI) breast tissue, and the diagnostic performance of DWI was assessed based on ADC thresholding. Results: Twenty-four of 27 (89%) malignant and 74/91 (81%) benign lesions were hyperintense on the b = 600 s/mm2 diffusion-weighted images. Both DCIS (1.33 ± 0.19 × 10−3 mm2/s) and invasive carcinomas (1.30 ± 0.27 × 10−3mm2/s) were lower in ADC than benign lesions (1.71 ± 0.43 × 10−3mm2/s; P < 0.001), and each lesion type was lower in ADC than normal tissue (1.90 ± 0.38 × 10−3mm2/s, P ≤ 0.001). Receiver operating curve (ROC) analysis showed an area under the curve (AUC) of 0.77, and sensitivity = 96%, specificity = 55%, positive predictive value (PPV) = 39%, and negative predictive value (NPV) = 98% for an ADC threshold of 1.60 × 10−3mm2/s. Conclusion: Many mammographically and clinically occult breast carcinomas were visibly hyperintense on diffusion-weighted images, and ADC enabled differentiation from benign lesions. Further studies evaluating DWI while blinded to DCE-MRI are necessary to assess the potential of DWI as a noncontrast breast screening technique. J. Magn. Reson. Imaging 2010;1:562-570. © 2010 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Purpose: To investigate whether diffusion tensor imaging (DTI) measures of anisotropy in breast tumors are different from normal breast tissue and can improve the discrimination between benign and malignant lesions. Materials and Methods: The study included 81 women with 105 breast lesions (76 malignant, 29 benign). DTI was performed during breast MRI examinations, and fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values were measured for breast lesions and normal tissue in each subject. FA and ADC were compared between cancers, benign lesions, and normal tissue by univariate and multivariate analyses. Results: The FA of carcinomas (mean ± SD: 0.24 ± 0.07) was significantly lower than normal breast tissue in the same subjects (0.29 ± 0.07; P < 0.0001). Multiple logistic regression showed that FA and ADC were each independent discriminators of malignancy ( P < 0.0001), and that FA improved discrimination between cancer and normal tissue over ADC alone. However, there was no difference in FA between malignant and benign lesions ( P = 0.98). Conclusion: Diffusion anisotropy is significantly lower in breast cancers than normal tissue, which may reflect alterations in tissue organization. Our preliminary results suggest that FA adds incremental value over ADC alone for discriminating malignant from normal tissue but does not help with distinguishing benign from malignant lesions. J. Magn. Reson. Imaging 2010; 31: 339-347. © 2010 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

Parasitism can influence many aspects of the host's behaviour and physiology, which in turn can have a profound impact on their population and evolutionary ecology. In many host–parasite interactions there is often a time lag between infection and the death of the host, yet little is known, experimentally or theoretically, about the effects that intra-class competition between parasitised and unparasitised hosts have on the host–parasite population dynamics. In this article we address this gap in our understanding using a stage-structured mathematical model for a host–parasitoid interaction, which has been parameterised for the Plodia–Venturia experimental system. In the case where parasitised larvae do not compete and do not cannibalise unparasitised larvae, our model predicts a wide range of host–parasitoid dynamics, ranging from host–parasitoid generation cycles, to host generation cycles with parasitoid half-generation cycles, to host–parasitoid equilibria, to host generation cycles with parasitoid extinction. However, when parasitised larvae can compete with their unparasitised larvae counterparts, the host–parasitoid population dynamics can dramatically change. In particular, we show that high levels of competition exerted by unparasitised larvae upon parasitised larvae is more likely to lead to parasitoid extinction. In addition, we demonstrate that unparasitised host larvae that are sufficiently susceptible to intra-class competition, or parasitised host larvae that are sufficiently strong competitors, can have a stabilising effect on the host–parasitoid population dynamics. The implications of these theoretical results are discussed in light of our understanding of host–parasitoid interactions and host–parasite systems in general. [ABSTRACT FROM AUTHOR]

We used the dual capability of hyperpolarized 129Xe for spectroscopy and imaging to develop new measures of xenon diffusing capacity in the rat lung that (analogously to the diffusing capacity of carbon monoxide or D LCO) are calculated as a product of total lung volume and gas transfer rate constants divided by the pressure gradient. Under conditions of known constant pressure breath-hold, the volume is measured by hyperpolarized 129Xe MRI, and the transfer rate is measured by dynamic spectroscopy. The new quantities (xenon diffusing capacity in lung parenchyma ( D LXeLP)), xenon diffusing capacity in RBCs ( D LXeRBC), and total lung xenon diffusing capacity ( D LXe)) were measured in six normal rats and six rats with lung inflammation induced by instillation of fungal spores of Stachybotrys chartarum. D LXeLP, D LXeRBC, and D LXe were 56 ± 10 ml/min/mmHg, 64 ± 35 ml/min/mmHg, and 29 ± 9 ml/min/mmHg, respectively, for normal rats, and 27 ± 9 ml/min/mmHg, 42 ± 27 ml/min/mmHg, and 16 ± 7 ml/min/mmHg, respectively, for diseased rats. Lung volumes and gas transfer times for LP ( T trLP) were 16 ± 2 ml and 22 ± 3 ms, respectively, for normal rats and 12 ± 2 ml and 35 ± 8 ms, respectively, for diseased rats. Xenon diffusing capacities may be useful for measuring changes in gas exchange associated with inflammation and other lung diseases. Magn Reson Med, 2006. © 2006 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

While researchers in alliance management have identified the duality of cooperation and control within alliances, comparative governance scholars have not yet developed a coherent framework for relating the costs of cooperation to governance choices. This paper proposes a theory of cooperation costs highlighting the importance of joint task complexity, interpartner diversity, equity and strategic implications on the perception of alliance value and the formation and evolution of hybrid governance structures. A tolerance frontier is used to predict conditions for alliance failure both ex ante and after formation, as well as conditions under which an alliance will evolve once formed. The framework is illustrated through an analysis of the initial structuring and subsequent changes in the NedCar alliance between Mitsubishi Motors and Volvo, and implications for further research are discussed. [ABSTRACT FROM AUTHOR]

This paper analyzes the learning process and sequential capabilities development in Lenovo, China's most successful PC manufacturer, which originated as a spin-off from a government-supported research institute. The case study reveals this firm's evolutionary, path-dependent and stage-wise progress from initial sales, distribution and service activities to manufacturing, product and process design and, finally developmental R&D. The study shows the interaction among the firm's changing environment, its competitive strategy, and its set of resources and capabilities. The case has implications for research on such organizations, as well as implications for management. [ABSTRACT FROM AUTHOR]

Purpose: Multiple, prolonged, generalized, or focal seizures are common in children with severe malaria, with or without coma. In other contexts, such seizures have been associated with the development of epilepsy. The relation between falciparum malaria and epilepsy is undetermined; thus we measured the prevalence and characteristics of epilepsy in children with a history of severe malaria. Methods: We took a detailed epilepsy history from the parents of 487 children (aged 6–9 years) to compare the prevalence of epilepsy between three exposure groups: children with a history of cerebral malaria (CM), malaria and complicated seizures (M/S), or those unexposed to either complication. Each child had an EEG and was classified as having active, inactive, or no epilepsy. Results: An increased prevalence of epilepsy was seen in children previously admitted with CM [9.2%; OR, 4.4; 95% confidence interval (CI), 1.4–13.7] or M/S (11.5%; OR, 6.1; 95% CI, 2.0–18.3) compared with the unexposed group (2.2%). The most commonly reported seizure types were tonic–clonic (42%), focal becoming secondarily generalized (16%), and both (21%). Twenty-six percent of the active epilepsy group initially had EEG abnormalities. Conclusions: These results suggest that children exposed to CM or M/S have an increased propensity for epilepsy relative to children unexposed to these complications. The prevalence of epilepsy associated with CM is similar to that reported after other severe encephalopathies. The prevalence associated with M/S is more than twice that reported after complicated febrile seizures. [ABSTRACT FROM AUTHOR]

Research in transition economics like China has sought and found explanations for strategic behaviour based on institutional and other social processes, leading to descriptions of China's emerging business system as 'network capitalism'. This paper argues, however that organizational capabilities and transaction costs are increasingly important influences on strategic choice as economic reforms proceed. An in-depth case study of of one firm's behaviour in two different asset markets - R&D and distribution in the Chinese pharmaceutical industry - illustrates fundamental differences in firm strategies for securing these assets. To account for this variety and move beyond the homogeneity implied by prior research, we propose a framework for differentiating the transition trajectories for different types of complementary assets. We propose conditions under which all three perspectives - institutional and social structure, organizational capabilities and transaction costs - predict similar trajectories and firm strategies, but different decision processes, and when their predictions differ. [ABSTRACT FROM AUTHOR]

Studies the N-terminal region of the heme-regulated elF2alpha kinase. Autonomous heme binding domain; Compatibility of the amino acid sequence with the globin fold; Theoretical significance of the study.

ABSTRACT Introduction: Patients with amyotrophic lateral sclerosis (ALS) are prone to venous thromboembolism (VTE) and secondary complications. Because there is an increased incidence of VTE after surgical procedures, placement of a Diaphragm Pacing System (DPS) in ALS patients as treatment for respiratory muscle weakness could potentially increase the incidence of VTE, especially in patients with limited mobility. Methods: We implanted a DPS in 10 ALS patients who met the criteria for this procedure. They underwent a preoperative evaluation as recommended by the guidelines. Results: We report 2 patients with no symptoms of deep vein thrombosis (DVT) before the surgical procedure who then developed perioperative VTE. Conclusions: These patients highlight the need to consider preoperative screening for DVT and postoperative thromboprophylaxis in high-risk ALS patients who undergo DPS placement. Muscle Nerve 50: 863-865, 2014 [ABSTRACT FROM AUTHOR]

The family systems theory of David Kantor and William Lehr as expressed in their book, Inside the Family, forms the foundation for the model of family therapy which is taught at the Family Institute of Cambridge. This paper is a summary of and an introduction to that theory. Their concepts of family boundaries, dimensions, typal arrangements, and the four player system are presented and discussed. [ABSTRACT FROM AUTHOR]