34 research outputs found
Modelling the Species Distribution of Flat-Headed Cats (Prionailurus planiceps), an Endangered South-East Asian Small Felid
Background: The flat-headed cat (Prionailurus planiceps) is one of the world’s least known, highly threatened felids with a
distribution restricted to tropical lowland rainforests in Peninsular Thailand/Malaysia, Borneo and Sumatra. Throughout its
geographic range large-scale anthropogenic transformation processes, including the pollution of fresh-water river systems
and landscape fragmentation, raise concerns regarding its conservation status. Despite an increasing number of cameratrapping
field surveys for carnivores in South-East Asia during the past two decades, few of these studies recorded the flatheaded
cat.
Methodology/Principal Findings: In this study, we designed a predictive species distribution model using the Maximum
Entropy (MaxEnt) algorithm to reassess the potential current distribution and conservation status of the flat-headed cat.
Eighty-eight independent species occurrence records were gathered from field surveys, literature records, and museum
collections. These current and historical records were analysed in relation to bioclimatic variables (WorldClim), altitude
(SRTM) and minimum distance to larger water resources (Digital Chart of the World). Distance to water was identified as the
key predictor for the occurrence of flat-headed cats (.50% explanation). In addition, we used different land cover maps
(GLC2000, GlobCover and SarVision LLC for Borneo), information on protected areas and regional human population density
data to extract suitable habitats from the potential distribution predicted by the MaxEnt model. Between 54% and 68% of
suitable habitat has already been converted to unsuitable land cover types (e.g. croplands, plantations), and only between
10% and 20% of suitable land cover is categorised as fully protected according to the IUCN criteria. The remaining habitats
are highly fragmented and only a few larger forest patches remain.
Conclusion/Significance: Based on our findings, we recommend that future conservation efforts for the flat-headed cat
should focus on the identified remaining key localities and be implemented through a continuous dialogue between local
stakeholders, conservationists and scientists to ensure its long-term survival. The flat-headed cat can serve as a flagship
species for the protection of several other endangered species associated with the threatened tropical lowland forests and
surface fresh-water sources in this region
Pathogenic Activation and Therapeutic Blockage of FcαR-Expressing Polymorphonuclear Leukocytes in IgA Pemphigus
Pathomechanisms in IgA pemphigus are assumed to rely on Fc-dependent cellular activation by antigen-specific IgA autoantibodies; however, models for the disease and more detailed pathophysiologic data are lacking. In this study, we aimed to establish in vitro models of disease for IgA pemphigus, allowing us to study the effects of the interaction of anti-keratinocyte IgA with cell surface FcαRs. Employing multiple in vitro assays, such as a skin cryosection assay and a human skin organ culture model, in this study, we present mechanistic data for the pathogenesis of IgA pemphigus, mediated by anti–desmoglein 3 IgA autoantibodies. Our results reveal that this disease is dependent on FcαR-mediated activation of leukocytes in the epidermis. Importantly, this cell-dependent pathology can be dose-dependently abrogated by peptide-mediated inhibition of FcαR:IgA-Fc interaction, as confirmed in an additional model for IgA-dependent disease, that is, IgA vasculitis. These data suggest that IgA pemphigus can be modeled in vitro and that IgA pemphigus and IgA vasculitis are FcαR-dependent disease entities that can be specifically targeted in these experimental systems
Measuring the quantum state of photoelectrons
A photoelectron, emitted due to the absorption of light quanta as described
by the photoelectric effect, is often characterized experimentally by a
classical quantity, its momentum. However, since the photoelectron is a quantum
object, its rigorous characterization requires the reconstruction of the
complete quantum state, the photoelectron's density matrix. Here, we use
quantum state tomography to fully characterize photoelectrons emitted from
helium and argon atoms upon absorption of ultrashort, extreme ultraviolet light
pulses. While in helium we measure a pure photoelectronic state, in argon,
spin-orbit interaction induces entanglement between the ion and the
photoelectron, leading to a reduced purity of the photoelectron state. Our work
shows how state tomography gives new insights into the fundamental quantum
aspects of light-induced electronic processes in matter, bridging the fields of
photoelectron spectroscopy and quantum information, and offering new
spectroscopic possibilities for quantum technology
Оптимизация параметров лазерного излучения для воздействия на пигменты на основе диоксида титана (TiO2)
В настоящее время не существует методики, позволяющей быстро и безопасно удалять татуировки и перманентный макияж, содержащие пигменты на основе диоксида титана. Тема работы является актуальной в связи с растущим спросом на такие услуги в сфере эстетической медицины, а данный пигмент является базой для широкого спектра пастельных и натуральных оттенков чернил. Объектом исследования являются дисперсные растворы диоксида титана. Целью данной работы является изучение влияния лазерного излучения на пигменты на основе диоксида титана. Полученные данные послужат основой для разработки методов удаления белых пигментов в татуировках и повысят эффективность удаления перманентного макияжа.Currently, there is no method to quickly and safely remove tattoos and permanent makeup containing titanium dioxide pigments. The topic of work is relevant in connection with the growing demand for such services in the field of aesthetic medicine, and this pigment is the base for a wide range of pastel and natural shades of ink. The object of the research are titanium dioxide dispersive solutions. The purpose of this work is to explore the effects of laser radiation on pigments based on titanium dioxide by changing its parameters. The obtained data will serve as the foundation for the development of methods for removing white pigments in tattoos and will increase the effectiveness of permanent makeup removal
<scp>ReSurveyEurope</scp>: A database of resurveyed vegetation plots in Europe
AbstractAimsWe introduce ReSurveyEurope — a new data source of resurveyed vegetation plots in Europe, compiled by a collaborative network of vegetation scientists. We describe the scope of this initiative, provide an overview of currently available data, governance, data contribution rules, and accessibility. In addition, we outline further steps, including potential research questions.ResultsReSurveyEurope includes resurveyed vegetation plots from all habitats. Version 1.0 of ReSurveyEurope contains 283,135 observations (i.e., individual surveys of each plot) from 79,190 plots sampled in 449 independent resurvey projects. Of these, 62,139 (78%) are permanent plots, that is, marked in situ, or located with GPS, which allow for high spatial accuracy in resurvey. The remaining 17,051 (22%) plots are from studies in which plots from the initial survey could not be exactly relocated. Four data sets, which together account for 28,470 (36%) plots, provide only presence/absence information on plant species, while the remaining 50,720 (64%) plots contain abundance information (e.g., percentage cover or cover–abundance classes such as variants of the Braun‐Blanquet scale). The oldest plots were sampled in 1911 in the Swiss Alps, while most plots were sampled between 1950 and 2020.ConclusionsReSurveyEurope is a new resource to address a wide range of research questions on fine‐scale changes in European vegetation. The initiative is devoted to an inclusive and transparent governance and data usage approach, based on slightly adapted rules of the well‐established European Vegetation Archive (EVA). ReSurveyEurope data are ready for use, and proposals for analyses of the data set can be submitted at any time to the coordinators. Still, further data contributions are highly welcome.</jats:sec
Cdc42 is a key regulator of B cell differentiation and is required for antiviral humoral immunity
The small Rho GTPase Cdc42, known to interact with Wiskott–Aldrich syndrome (WAS) protein, is an important regulator of actin remodeling. Here, we show that genetic ablation of Cdc42 exclusively in the B cell lineage is sufficient to render mice unable to mount antibody responses. Indeed Cdc42-deficient mice are incapable of forming germinal centers or generating plasma B cells upon either viral infection or immunization. Such severe immune deficiency is caused by multiple and profound B cell abnormalities, including early blocks during B cell development; impaired antigen-driven BCR signaling and actin remodeling; defective antigen presentation and in vivo interaction with T cells; and a severe B cell–intrinsic block in plasma cell differentiation. Thus, our study presents a new perspective on Cdc42 as key regulator of B cell physiology