Trade-offs between performance and tolerance of abiotic and biotic stress have been proposed to explain both the success of invasive species and frequently observed size differences between native and introduced populations.Canada thistle seeds collected from across the introduced North American and the native European range were grown in benign and stressful conditions(nutrient stress,shading,simulated herbivory,drought,and mowing),to evaluate whether native and introduced individuals differ in performance or stress tolerance.An additional experiment assessed the strength of maternal effects by comparing plants derived from field-collected seeds with those derived from clones grown in the glasshouse.Introduced populations tended to be larger in size,but no trade-off of stress tolerance with performance was detected;introduced populations had either superior performance or equivalent trait values and survivorship in the treatment common gardens.We also detected evidence of parallel latitudinal clines of some traits in both the native and introduced ranges and associations with climate variables in some treatments,consistent with recent climate adaptation within the introduced range.Our results are consistent with rapid adaptation of introduced populations,but,contrary to predictions,the evolution of invasive traits did not come at the cost of reduced stress tolerance.
Individual atomic defects in 2D materials impact their macroscopic functionality.Correlating the interplay is challenging,however,intelligent hyperspectral scanning tunneling spectroscopy(STS)mapping provides a feasible solution to this technically difficult and time consuming problem.Here,dense spectroscopic volume is collected autonomously via Gaussian process regression,where convolutional neural networks are used in tandem for spectral identification.Acquired data enable defect segmentation,and a workflow is provided for machine-driven decision making during experimentation with capability for user customization.We provide a means towards autonomous experimentation for the benefit of both enhanced reproducibility and user-accessibility.Hyperspectral investigations on WS_(2)sulfur vacancy sites are explored,which is combined with local density of states confirmation on the Au{111}herringbone reconstruction.Chalcogen vacancies,pristine WS_(2),Au face-centered cubic,and Au hexagonal close-packed regions are examined and detected by machine learning methods to demonstrate the potential of artificial intelligence for hyperspectral STS mapping.
Film cooling is an important measure to enable an increase of the inlet temperature of a gas turbine and, thereby, to improve its overall efficiency. The coolant is ejected through spanwise rows of holes in the blades or endwalls to build up a film shielding the material. The holes often are inclined in the downstream direction and give rise to a kidney vortex. This is a counter-rotating vortex pair, with an upward flow direction between the two vortices, which tends to lift off the surface and to locally feed hot air towards the blade outside the pair. Reversing the rotational sense of the vortices reverses these two drawbacks into advantages. In the considered case, an anti-kidney vortex is generated using two subsequent rows of holes both inclined downstream and yawed spanwise with alternating angles. In a previous study, we performed large-eddy simulations (which focused on the fully turbulent boundary layer) of this anti-kidney vortex film-cooling and compared them to a corresponding physical experiment. The present work analyzes the simulated flow field in detail, beginning in the plenum (inside the blade or endwall) through the holes up to the mixture with the hot boundary layer. To identify the vortical structures found in the mean flow and in the instantaneous flow, we mostly use the λ 2 criterion and the line integral convolution (LIC) technique indicating sectional streamlines. The flow regions (coolant plenum, holes, and boundary layer) are studied subsequently and linked to each other. To track the anti-kidney vortex throughout the boundary layer, we propose two criteria which are based on vorticity and on LIC results. This enables us to associate the jet vortices with the cooling effectiveness at the wall, which is the key feature of film cooling.
Multimode fibers(MMFs)are an example of a highly scattering medium,which scramble the coherent light propagating within them to produce seemingly random patterns.Thus,for applications such as imaging and image projection through an MMF,careful measurements of the relationship between the inputs and outputs of the fiber are required.We show,as a proof of concept,that a deep neural network can learn the input-output relationship in a 0.75 m long MMF.Specifically,we demonstrate that a deep convolutional neural network(CNN)can learn the nonlinear relationships between the amplitude of the speckle pattern(phase information lost)obtained at the output of the fiber and the phase or the amplitude at the input of the fiber.Effectively,the network performs a nonlinear inversion task.We obtained image fidelities(correlations)as high as~98%for reconstruction and~94%for image projection in the MMF compared with the image recovered using the full knowledge of the system transmission characterized with the complex measured matrix.We further show that the network can be trained for transfer learning,i.e.,it can transmit images through the MMF,which belongs to another class not used for training/testing.
Genome wide association studies have associated single nucleotide polymorphisms within the gene locus encoding protein tyrosine phosphatase non-receptor type 2(PTPN2) with the onset of inflammatory bowel disease(IBD) and other inflammatory disorders. Expression of PTPN2 is enhanced in actively inflamed intestinal tissue featuring a marked up-regulation in intestinal epithelial cells. PTPN2 deficient mice suffer from severe intestinal and systemic inflammation and display aberrant innate and adaptive immune responses. In particular, PTPN2 is involved in the regulation of inflammatory signalling cascades, and critical for protecting intestinal epithelial barrier function, regulating innate and adaptive immune responses, and finally for maintaining intestinal homeostasis. On one hand, dysfunction of PTPN2 has drastic effects on innate host defence mechanisms, including increased secretion of pro-inflammatory cytokines, limited autophagosome formation in response to invading pathogens, and disruption of the intestinal epithelial barrier. On the other hand, PTPN2 function is crucial for controlling adaptive immune functions, by regulating T cell proliferation and differentiation as well as maintaining T cell tolerance. In this way, dysfunction of PTPN2 contributes to the manifestation of IBD. The aim of this review is to present an overview of recent findings on the role of PTPN2 in intestinal homeostasis and the impact of dysfunctional PTPN2 on intestinal inflammation.
Marianne R SpalingerDeclan F McColeGerhard RoglerMichael Scharl
AIM To characterize antiviral therapy eligibility among hepatitis B virus(HBV)-infected adults at a university hospital in Zambia.METHODS Hepatitis B surface antigen-positive adults(n = 160) who were h IV-negative and referred to the hospital after a routine or clinically-driven HBV test were enrolled. Alanine Aminotransferase(ALT),Aspartate Aminotransferase(AST),platelet count,hepatitis B e-antigen,and HBV DNA were measured. Liver fibrosis/cirrhosis was assessed by physical examination,AST-to-platelet ratio index,and transient elastography. In antiviral therapy-na?ve individuals,we described hBV stages and antiviral therapy eligibility per World health Organization(WhO) and by hBV test(routine vs clinical). Elevated ALT was > 19 in women and > 30 U/L in men. Among treatmentexperienced individuals,we described medication side effects,adherence,and viral suppression.RESULTS The median age was 33 years,71.9% were men,and 30.9% were diagnosed with HBV through a clinicallydriven test with the remainder identified via routine testing(at the blood bank,community events,etc.). Among 120 treatment-na?ve individuals,2.5% were categorized as immune tolerant,11.7% were immune active,35.6% were inactive carriers,and 46.7% had an indeterminate phenotype. Per WhO guidelines,13(10.8%) were eligible for immediate antiviral therapy. The odds of eligibility were eight times higher for those diagnosed at clinical vs routine settings(adjusted odds ratio,8.33; 95%CI: 2.26-29.41). Among 40 treatmentexperienced hBV patients,virtually all took tenofovir,and a history of mild side effects was reported in 20%. Though reported adherence was good,12 of 29(41.4%) had HBV DNA > 20 IU/m L. CONCLUSION Approximately one in ten HBV-monoinfected Zambians were eligible for antivirals. Many had indeterminate phenotype and needed clinical follow-up.
Michael J VinikoorEdford SinkalaAnnie KanungaMutinta MuchimbaBright NsokoloRoma ChilengiGilles WandelerJoseph MulengaTina ChisengaDebika BhattacharyaMichael S SaagGraham FosterMichael W FriedPaul Kelly
Light sheet fluorescence microscopy(LSFM)is rapidly becoming an essential technology for mesoscopic imaging of samples such as embryos and adult mouse organs.However,LSFM can suffer from optical artifacts for which there is no intrinsic solution.The attenuation of light due to absorbing material causes“shadow”artifacts along both the illumination and detection paths.Several approaches have been introduced to reduce this problem,including scanning illumination and multi-view imaging.However,neither of these approaches completely eliminates the problem.If the distribution of the absorbing material is complex,shadows cannot be avoided.We introduce a new approach that relies on multi-modal integration of two very different mesoscopic techniques.Unlike LSFM,optical projection tomography(OPT)can operate in transmission mode to create a voxel map of the 3D distribution of the sample’s optical attenuation.Here,we demonstrate a hybrid instrument(OPTiSPIM)that can quantify this attenuation and use the information to correct the shadow artifacts of LSFM.
Jürgen MayerAlexandre Robert-MorenoJames SharpeJim Swoger
The intestinal microbiota plays a crucial role in health and changes in its composition are linked with major global human diseases.Fully understanding what shapes the human intestinal microbiota composition and knowing ways of modulating the composition are critical for promotion of life-course health,combating diseases,and reducing global health disparities.We aim to provide a foundation for understanding what shapes the human intestinal microbiota on an individual and global scale,and how interventions could utilize this information to promote life-course health and reduce global health disparities.We briefly review experiences within the first 1,000 days of life and how long-termexposures to environmental elements or geographic specific cultures have lasting impacts on the intestinal microbiota.We also discuss major public health threats linked to the intestinal microbiota,including antimicrobial resistance and disappearing microbial diversity due to globalization.In order to promote global health,we argue that the interplay of the larger ecosystem with intestinal microbiota research should be utilized for future research and urge for global efforts to conserve microbial diversity.
Electrosorption of solvated species at metal electrodes is a most fundamental class of processes in interfacial electrochemistry.Here,we use its sensitive dependence on the electric double layer to assess the performance of ab initio thermodynamics approaches increasingly used for the first-principles description of electrocatalysis.We show analytically that computational hydrogen electrode calculations at zero net-charge can be understood as a first-order approximation to a fully grand canonical approach.Notably,higher-order terms in the applied potential caused by the charging of the double layer include contributions from adsorbate-induced changes in the work function and in the interfacial capacitance.These contributions are essential to yield prominent electrochemical phenomena such as non-Nernstian shifts of electrosorption peaks and non-integer electrosorption valencies.We illustrate this by calculating peak shifts for H on Pt electrodes and electrosorption valencies of halide ions on Ag electrodes,obtaining qualitative agreement with experimental data already when considering only second order terms.The results demonstrate the agreement between classical electrochemistry concepts and a first-principles fully grand canonical description of electrified interfaces and shed new light on the widespread computational hydrogen electrode approach.
The many ways parasites can impact their host species have been the focus of intense study using a range of approaches. A particularly promising but under-used method in this context is experimental evolution, because it allows targeted manipulation of known populations exposed to contrasting conditions. The strong potential of applying this method to the study of insect hosts and their associated parasites is demonstrated by the few available long-term experiments where insects have been exposed to parasites. In this review, we summarize these studies, which have delivered valuable insights into the evolution of resistance in response to parasite pressure, the underlying mechanisms, as well as correlated genetic responses. We further assess findings from relevant artificial selection studies in the interrelated contexts of immunity, life history, and reproduction. In addition, we discuss a number of well-studied Tribolium castaneum-Nosema whitei coevolution experiments in more detail and provide suggestions for research. Specifically, we suggest that future experiments should also be performed using nonmodel hosts and should incorporate contrasting experimental conditions, such as population sizes or envi- ronments. Finally, we expect that adding a third partner, for example, a second parasite or symbiont, to a host-parasite system could strongly impact （co）evolutionary dynamics.
