Background Agricultural production is often limited by low phosphorus (P) availability. In developing countries, which have limited access to P fertiliser, there is a need to develop plants that are ...more efficient at low soil P. In fertilised and intensive systems, P-efficient plants are required to minimise inefficient use of P-inputs and to reduce potential for loss of P to the environment. Scope Three strategies by which plants and microorganisms may improve P-use efficiency are outlined: (i) Root-foraging strategies that improve P acquisition by lowering the critical P requirement of plant growth and allowing agriculture to operate at lower levels of soil P; (ii) P-mining strategies to enhance the desorption, solubilisation or mineralisation of P from sparingly-available sources in soil using root exudates (organic anions, phosphatases), and (iii) improving internal P-utilisation efficiency through the use of plants that yield more per unit of P uptake.
Microplastics have been observed in indoor and outdoor air. This raises concern for human exposure, especially should they occur in small enough sizes, which if inhaled, reach the central airway and ...distal lung. As yet, methods for their detection have not spectroscopically verified the chemical composition of microplastics in this size-range. One proposed method is an automated spectroscopic technique, Raman spectral imaging; however, this generates large and complex data sets. This study aims to optimize Raman spectral imaging for the identification of microplastics (≥2 μm) in ambient particulate matter, using different chemometric techniques. We show that Raman spectral images analyzed using chemometric statistical approaches are appropriate for the identification of both virgin and environmental microplastics ≥2 μm in size. On the basis of the sensitivity, we recommend using the developed Pearson’s correlation and agglomerative hierarchical cluster analysis for the identification of microplastics in spectral data sets. Finally, we show their applicability by identifying airborne microplastics >4.7 μm in an outdoor particulate matter sample obtained at an urban sampling site in London, United Kingdom. This semiquantitative method will enable the procurement of exposure concentrations of airborne microplastics guiding future toxicological assessments.
Summary Background Tuberculosis incidence in the UK has risen in the past decade. Disease control depends on epidemiological data, which can be difficult to obtain. Whole-genome sequencing can detect ...microevolution within Mycobacterium tuberculosis strains. We aimed to estimate the genetic diversity of related M tuberculosis strains in the UK Midlands and to investigate how this measurement might be used to investigate community outbreaks. Methods In a retrospective observational study, we used Illumina technology to sequence M tuberculosis genomes from an archive of frozen cultures. We characterised isolates into four groups: cross-sectional, longitudinal, household, and community. We measured pairwise nucleotide differences within hosts and between hosts in household outbreaks and estimated the rate of change in DNA sequences. We used the findings to interpret network diagrams constructed from 11 community clusters derived from mycobacterial interspersed repetitive-unit–variable-number tandem-repeat data. Findings We sequenced 390 separate isolates from 254 patients, including representatives from all five major lineages of M tuberculosis . The estimated rate of change in DNA sequences was 0·5 single nucleotide polymorphisms (SNPs) per genome per year (95% CI 0·3–0·7) in longitudinal isolates from 30 individuals and 25 families. Divergence is rarely higher than five SNPs in 3 years. 109 (96%) of 114 paired isolates from individuals and households differed by five or fewer SNPs. More than five SNPs separated isolates from none of 69 epidemiologically linked patients, two (15%) of 13 possibly linked patients, and 13 (17%) of 75 epidemiologically unlinked patients (three-way comparison exact p<0·0001). Genetic trees and clinical and epidemiological data suggest that super-spreaders were present in two community clusters. Interpretation Whole-genome sequencing can delineate outbreaks of tuberculosis and allows inference about direction of transmission between cases. The technique could identify super-spreaders and predict the existence of undiagnosed cases, potentially leading to early treatment of infectious patients and their contacts. Funding Medical Research Council, Wellcome Trust, National Institute for Health Research, and the Health Protection Agency.
Schizophrenia and autism are thought to result from the interaction between a susceptibility genotype and environmental risk factors. The offspring of women who experience infection while pregnant ...have an increased risk for these disorders. Maternal immune activation (MIA) in pregnant rodents produces offspring with abnormalities in behavior, histology, and gene expression that are reminiscent of schizophrenia and autism, making MIA a useful model of the disorders. However, the mechanism by which MIA causes long-term behavioral deficits in the offspring is unknown. Here we show that the cytokine interleukin-6 (IL-6) is critical for mediating the behavioral and transcriptional changes in the offspring. A single maternal injection of IL-6 on day 12.5 of mouse pregnancy causes prepulse inhibition (PPI) and latent inhibition (LI) deficits in the adult offspring. Moreover, coadministration of an anti-IL-6 antibody in the poly(I:C) model of MIA prevents the PPI, LI, and exploratory and social deficits caused by poly(I:C) and normalizes the associated changes in gene expression in the brains of adult offspring. Finally, MIA in IL-6 knock-out mice does not result in several of the behavioral changes seen in the offspring of wild-type mice after MIA. The identification of IL-6 as a key intermediary should aid in the molecular dissection of the pathways whereby MIA alters fetal brain development, which can shed new light on the pathophysiological mechanisms that predispose to schizophrenia and autism.
The choice of the best basal friction law to use in ice‐sheet models remains a source of uncertainty in projections of sea level. The parameters in commonly used friction laws can produce a broad ...range of behavior and are poorly constrained. Here we use a time series of elevation and speed data to examine the simulated transient response of Pine Island Glacier, Antarctica, to a loss of basal traction as its grounding line retreats. We evaluate a variety of friction laws, which produces a diversity of responses, to determine which best reproduces the observed speedup when forced with the observed thinning. Forms of the commonly used power law friction provide much larger model‐data disagreement than less commonly used regularized Coulomb friction in which cavitation effects yield an upper bound on basal friction. Thus, adoption of such friction laws could substantially improve the fidelity of large‐scale simulations to determine future sea level.
Plain Language Summary
Although much effort has gone into improving numerical simulations of ice‐sheet behavior for sea‐level projection, the best choice for the friction law that governs the sliding of ice over its bed remains poorly known. As a consequence, a wide range of friction laws is used by the ice‐sheet modeling community. Here we take advantage of several remotely sensed data sets to model the changes in speed of Pine Island Glacier, Antarctica, over nearly two decades, using a variety of existing friction laws. We find that the behavior of this glacier is simulated far more faithfully relative to observations when a “regularized Coulomb” friction law is used. This type of friction law accounts for the formation of pressurized basal water pockets (cavitation) that occur when ice slides rapidly over its bed, which limits friction in a way that may amplify ice‐sheet instability. By contrast, low‐order exponents in more traditional power law friction parameterizations yield unbounded basal friction as speed increases, placing a much stronger brake on unstable ice‐sheet behavior. Thus, these results make a strong case for adopting bounded regularized Coulomb friction laws in place of the more commonly used unbounded friction laws.
Key Points
The recent behavior of Pine Island Glacier is reproduced best with regularized Coulomb friction, which works for both hard and soft beds
Different representations of effective pressure in similar regularized Coulomb friction laws can produce vastly different behavior
Relative to many commonly used friction laws, Coulomb friction laws have the potential to improve projections of future sea‐level rise
The human frontal cortex helps mediate working memory, a system that is used for temporary storage and manipulation of information and that is involved in many higher cognitive functions. Working ...memory includes two components: short-term storage (on the order of seconds) and executive processes that operate on the contents of storage. Recently, these two components have been investigated in functional neuroimaging studies. Studies of storage indicate that different frontal regions are activated for different kinds of information: storage for verbal materials activates Broca's area and left-hemisphere supplementary and premotor areas; storage of spatial information activates the right-hemisphere premotor cortex; and storage of object information activates other areas of the prefrontal cortex. Two of the fundamental executive processes are selective attention and task management. Both processes activate the anterior cingulate and dorsolateral prefrontal cortex.
The reactive oxygen species (ROS)-producing enzyme NADPH oxidase (NOX) was first identified in the membrane of phagocytic cells. For many years, its only known role was in immune defense, where its ...ROS production leads to the destruction of pathogens by the immune cells. NOX from phagocytes catalyzes, via one-electron trans-membrane transfer to molecular oxygen, the production of the superoxide anion. Over the years, six human homologs of the catalytic subunit of the phagocyte NADPH oxidase were found: NOX1, NOX3, NOX4, NOX5, DUOX1, and DUOX2. Together with the NOX2/gp91
component present in the phagocyte NADPH oxidase assembly itself, the homologs are now referred to as the NOX family of NADPH oxidases. NOX are complex multidomain proteins with varying requirements for assembly with combinations of other proteins for activity. The recent structural insights acquired on both prokaryotic and eukaryotic NOX open new perspectives for the understanding of the molecular mechanisms inherent to NOX regulation and ROS production (superoxide or hydrogen peroxide). This new structural information will certainly inform new investigations of human disease. As specialized ROS producers, NOX enzymes participate in numerous crucial physiological processes, including host defense, the post-translational processing of proteins, cellular signaling, regulation of gene expression, and cell differentiation. These diversities of physiological context will be discussed in this review. We also discuss NOX misregulation, which can contribute to a wide range of severe pathologies, such as atherosclerosis, hypertension, diabetic nephropathy, lung fibrosis, cancer, or neurodegenerative diseases, giving this family of membrane proteins a strong therapeutic interest.
We investigated Autism social identity and mental health in autistic people. Autistic people have social and communication deficits, and experience social stigma—factors that could interfere with the ...development of positive social identity. Indeed, autistic participants (N = 272) had significantly lower personal self‐esteem, and higher levels of depression and anxiety than typically developing controls (N = 267). Autism social identification was positively associated with personal self‐esteem, and this relationship was mediated by collective self‐esteem (perceived positivity of Autism identity). Furthermore, there were significant negative indirect effects between Autism identification and anxiety, and between Autism identification and depression, through increases in collective self‐esteem and personal self‐esteem. Thus, while autistic participants reported poorer mental health than average, having a positive Autism social identity appeared to offer a protective mechanism. This implies that to improve mental health in the Autism population, clinical approaches should aim to facilitate development of positive Autism identities.
In 1964, W. D. Hamilton proposed a novel solution to the long-standing evolutionary puzzle: why do individuals cooperate? Hamilton predicted that, if individuals possess the ability to discriminate ...on the basis of kinship, then they should gain inclusive fitness benefits by biasing helpful behaviour towards relatives and harmful behaviour away from them. The possibility that kin selection might favour social evolution has now inspired five decades of active research. Here, I synthesize this evidence for social mammals. First, I report on the methodological advances that allow for pedigree construction, and review the evidence for maternal and paternal kin discrimination. Second, I recognize that a substantial body of evidence for the evolution of cooperative breeding via kin selection exists, and then focus on the potential for kin selection to favour less well understood, yet equally salient, targets of selection: social partner choice, coalition formation and social tolerance (withholding aggression). I find that kin selection favours remarkably similar patterns of nepotism in primate and nonprimates with respect to these short-lived social acts. Although social alliances among maternal and paternal kin are common in mammalian societies, kinship largely fails to protect individuals from aggression. Thus, an individual's closest associates and allies, many of whom are kin, are most often an individual's closest competitors within mammalian social groups. Taken together, these findings highlight the value of Hamilton's holistic approach in simultaneously considering the direct benefits of competition and the indirect fitness benefits of cooperation. Despite major empirical advances since the inception of kin selection theory, future tests using newly available molecular and statistical methods in combination with longitudinal behavioural data are required to partition the relative contributions of direct and indirect fitness on the lifetime inclusive fitness. Such approaches will elucidate the relative influences of evolutionary and ecological forces favouring social evolution across the mammalian lineage of social mammals.
•W. D. Hamilton's (1964) kin selection theory has now inspired five decades of research.•Inclusive benefits of short-lived social acts have been largely overlooked for social mammals.•Kinship promotes associations and coalitions, but rarely tolerance in primates and nonprimates.•Context-dependent costs (competition) and benefits (cooperation) are both important.•Longitudinal data should be combined with new methods to elucidate lifetime fitness consequences.
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