Arabidopsis Roots and Shoots Show Distinct Temporal Adaptation Patterns toward Nitrogen Starvation

Nitrogen (N) is an essential macronutrient for plants. N levels in soil vary widely, and plants have developed strategies to cope with N deficiency. However, the regulation of these adaptive responses and the coordinating signals that underlie them are still poorly understood. The aim of this study was to characterize N starvation in adult Arabidopsis (Arabidopsis thaliana) plants in a spatiotemporal manner by an integrative, multilevel global approach analyzing growth, metabolites, enzyme activities, and transcript levels. We determined that the remobilization of N and carbon compounds to the growing roots occurred long before the internal N stores became depleted. A global metabolite analysis by gas chromatography-mass spectrometry revealed organ-specific differences in the metabolic adaptation to complete N starvation, for example, for several tricarboxylic acid cycle intermediates, but also for carbohydrates, secondary products, and phosphate. The activities of central N metabolism enzymes and the capacity for nitrate uptake adapted to N starvation by favoring N remobilization and by increasing the high-affinity nitrate uptake capacity after long-term starvation. Changes in the transcriptome confirmed earlier studies and added a new dimension by revealing specific spatiotemporal patterns and several unknown N starvation-regulated genes, including new predicted small RNA genes. No global correlation between metabolites, enzyme activities, and transcripts was evident. However, this multilevel spatiotemporal global study revealed numerous new patterns of adaptation mechanisms to N starvation. In the context of a sustainable agriculture, this work will give new insight for the production of crops with increased N use efficiency

Injury rate and injury pattern among elite World Cup snowboarders: A 6-year cohort study

Masteroppgave - Norges idrettshøgskole, 2013Background: There is limited knowledge on injury rate and injury pattern in the different disciplines among elite snowboarders Objective: The aim of this study was to describe and compare the injury rate and injury pattern among the different International Ski Federation (FIS) World Cup (WC) snowboard disciplines with a precise calculation of exposure. Methods: We conducted retrospective interviews with FIS WC snowboard athletes at the end of each season in the period 2007-2012, to register injuries sustained during the competitive season. To calculate the exposure we obtained information from result lists from FIS’ competition database for all WC competitions for each of the interviewed athletes. Results: We registered a total of 574 injuries among 1432 athletes. Of these, 171 occurred during FIS WC competitions. The total relative and absolute injury rate were 6.4 injuries per 1000 runs and 40.1 injuries per 100 athletes per season, respectively. The relative injury rate was 11.9 per 1000 runs in snowboard cross, 6.3 in halfpipe, 3.6 in big air, and 2.8 in parallel giant slalom/parallel slalom (PGS/PSL). Conclusion: The absolute and the relative injury rate were significantly higher in snowboard cross than in halfpipe, big air and PGS/PSL. Snowboard cross had also the highest risk of severe injuries (> 28 days absence). The risk of knee injury (the most common injury type) and head injury was significant higher in snowboard cross and halfpipe compared to PGS/PSL. No differences in the relative or absolute injury rate between male and female snowboarders were detected

The Clash of the Trinities: A New Theoretical Analysis of the General Nature of War

This monograph reimagines war’s fundamental nature, extending Clausewitz’s theory of its political origin and “Trinitarian” elements in a way that embraces alternative, sociological explanations like that of John Keegan. Ultimately, it proposes a new way to visualize the complexities of war’s intrinsic elements, operating at any scale, and expresses war with a completely new and universal definition.https://press.armywarcollege.edu/monographs/1406/thumbnail.jp

Measuring the effectiveness of using rangers to deliver a behavior change campaign on sustainable palm oil in a UK zoo

A fundamental objective of modern zoos is promoting pro-environmental behaviors. This study experimentally assessed the contribution of zoo rangers (staff employed to engage visitors) in delivering a behavior change campaign promoting sustainable palm oil use. The campaign was delivered in a dedicated area in a walk-through animal exhibit, with rangers either “present” or “absent” in the campaign space. Questionnaires assessing awareness, knowledge, and purchasing intentions were completed by 1032 visitors. Two analyses were conducted: (1) comparing the impact of ranger presence versus absence (to assess the overall impact of having rangers present regardless of whether they talked to visitors) and (2) comparing the impact of talking to a ranger against demographically matched individuals visiting when rangers were absent (to assess the specific impact of talking to a ranger). Visitors who talked to rangers were more aware of palm oil, had more knowledge, and greater intentions of purchasing sustainable palm oil. However, as only one-quarter of visitors talked to a ranger, fewer differences were found comparing ranger presence versus absence. These findings suggest that rangers can be instrumental in communicating complex conservation issues and delivering zoo-based behavior change campaigns, but their impact is limited by low engagement rates

Camp stability predicts patterns of hunter-gatherer cooperation.

Humans regularly cooperate with non-kin, which has been theorized to require reciprocity between repeatedly interacting and trusting individuals. However, the role of repeated interactions has not previously been demonstrated in explaining real-world patterns of hunter-gatherer cooperation. Here we explore cooperation among the Agta, a population of Filipino hunter-gatherers, using data from both actual resource transfers and two experimental games across multiple camps. Patterns of cooperation vary greatly between camps and depend on socio-ecological context. Stable camps (with fewer changes in membership over time) were associated with greater reciprocal sharing, indicating that an increased likelihood of future interactions facilitates reciprocity. This is the first study reporting an association between reciprocal cooperation and hunter-gatherer band stability. Under conditions of low camp stability individuals still acquire resources from others, but do so via demand sharing (taking from others), rather than based on reciprocal considerations. Hunter-gatherer cooperation may either be characterized as reciprocity or demand sharing depending on socio-ecological conditions

On reaction thresholds in doubly special relativity

Two theories of special relativity with an additional invariant scale, "doubly special relativity" (DSR), are tested with calculations of particle process kinematics. Using the Judes-Visser modified conservation laws, thresholds are studied in both theories. In contrast to some linear approximations, which allow for particle processes forbidden in special relativity, both the Amelino-Camelia and Maguejo-Smolin frameworks allow no additional processes. To first order, the Amelino-Camelia framework thresholds are lowered and the Maguejo-Smolin framework thresholds may be raised or lowered.Comment: 13 pages,v3 added comments regarding the assumption of composite particles,minor wording changes, version to be publishe

Application of J Integral for the Fracture Assessment of Welded Polymeric Components

For many demanding applications of engineering plastics, fracture behaviour under various loading conditions is of prime practical importance. It is well known that fracture properties of plastics are significantly affected by the loading rate, temperature and both local and global stress states. The limitations associated with conventional fracture test methods may, at least in principle, be overcome by the use of appropriate fracture mechanical approaches, which properly account for the temperature and rate dependence of the mechanical behaviour of plastics and should provide geometry-independent fracture toughness values. To provide an additional contribution to this application, fracture tests were performed on both 15- and 20-mm-thick bulk-extruded sheets of a polypropylene random copolymer (PP(RC)) and on four different configurations of their welded joints. The fully ductile fracture range was determined by rate-dependent tests on single CT specimens, and fracture toughness values were derived at the peak loads (JFmax and CTODFmax). Fracture toughness values were determined for stable crack extension based on the J-Δa and/or CTOD-Δa R-curves using single and multiple specimens in terms of various definitions of the crack initiation (J0.2, J0.2BL or δ0.2) toughness values. As expected, both methods revealed distinct differences between the bulk materials and the welded joints. These differences were found to depend on the loading rate, the weld configuration and on the data reduction method (J integral or CTOD)

Factors underlying Ebola virus infection among health workers, Kenema, Sierra Leone, 2014-2015

Background. Ebola virus disease (EVD) in health workers (HWs) has been a major challenge during the 2014-2015 outbreak. We examined factors associated with Ebola virus exposure and mortality in HWs in Kenema District, Sierra Leone. Methods. We analyzed data from the Sierra Leone National Viral Hemorrhagic Fever Database, contact tracing records, Kenema Government Hospital (KGH) staff and Ebola Treatment Unit (ETU) rosters, and burial logs.Results. From May 2014 through January 2015, 600 cases of EVD originated in Kenema District, including 92 (15%) HWs, 66 (72%) of whom worked at KGH. Among KGH medical staff and international volunteers, 18 of 62 (29%) who worked in the ETU developed EVD, compared with 48 of 83 (58%) who worked elsewhere in the hospital. Thirteen percent of HWs with EVD reported contact with EVD patients, while 27% reported contact with other infected HWs. The number of HW EVD cases at KGH declined roughly 1 month after implementation of a new triage system at KGH and the opening of a second ETU within the district. The case fatality ratio for HWs and non-HWs with EVD was 69% and 74%, respectively.Conclusions. The cluster of HW EVD cases in Kenema District is one of the largest ever reported. Most HWs with EVD had potential virus exposure both inside and outside of hospitals. Prevention measures for HWs must address a spectrum of infection risks in both formal and informal care settings as well as in the community.Publisher PDFPeer reviewe