Negative effects of nitrogen deposition on Swiss butterflies.

Nitrogen (N) deposition from agriculture and combustion of fossil fuels is a major threat to plant diversity, but its effects on organisms at higher trophic levels are unclear. We investigated how N deposition may affect species richness and abundance (number of individuals per species) in butterflies. We reviewed the peer-reviewed literature on variables used to explain spatial variation in butterfly species richness and found that vegetation variables appeared to be as important as climate and habitat variables in explaining butterfly species richness.

Environmental and Anthropogenic Factors Shape Major Bacterial Community Types Across the Complex Mountain Landscape of Switzerland.

Mountain areas harbor large climatic and geographic gradients and form numerous habitats that promote high overall biodiversity. Compared to macroorganisms, knowledge about drivers of biodiversity and distribution of soil bacteria in mountain regions is still scarce but a prerequisite for conservation of bacterial functions in soils. An important question is, whether soil bacterial communities with similar structures share environmental preferences.

Measuring Efficiency of Semi-automated Brain Tumor Segmentation by Simulating User Interaction.

Traditionally, radiologists have crudely quantified tumor extent by measuring the longest and shortest dimension by dragging a cursor between opposite boundary points across a single image rather than full segmentation of the volumetric extent. For algorithmic-based volumetric segmentation, the degree of radiologist experiential involvement varies from confirming a fully automated segmentation, to making a single drag on an image to initiate semi-automated segmentation, to making multiple drags and clicks on multiple images during interactive segmentation. An experiment was designed to test an algorithm that allows various levels of interaction.

Species turnover reveals hidden effects of decreasing nitrogen deposition in mountain hay meadows.

Nitrogen (N) deposition is a major threat to biodiversity in many habitats. The recent introduction of cleaner technologies in Switzerland has led to a reduction in the emissions of nitrogen oxides, with a consequent decrease in N deposition. We examined different drivers of plant community change, that is, N deposition, climate warming, and land-use change, in Swiss mountain hay meadows, using data from the Swiss biodiversity monitoring program.

Using change-point models to estimate empirical critical loads for nitrogen in mountain ecosystems.

To protect ecosystems and their services, the critical load concept has been implemented under the framework of the Convention on Long-range Transboundary Air Pollution (UNECE) to develop effects-oriented air pollution abatement strategies. Critical loads are thresholds below which damaging effects on sensitive habitats do not occur according to current knowledge. Here we use change-point models applied in a Bayesian context to overcome some of the difficulties when estimating empirical critical loads for nitrogen (N) from empirical data.

Nitrogen deposition and multi-dimensional plant diversity at the landscape scale.

Estimating effects of nitrogen (N) deposition is essential for understanding human impacts on biodiversity. However, studies relating atmospheric N deposition to plant diversity are usually restricted to small plots of high conservation value. Here, we used data on 381 randomly selected 1 km(2) plots covering most habitat types of Central Europe and an elevational range of 2900 m.

BNIP3 regulates AT101 [(-)-gossypol] induced death in malignant peripheral nerve sheath tumor cells.

Malignant peripheral nerve sheath tumors (MPNSTs) are aggressive Schwann cell-derived sarcomas and are the leading cause of mortality in patients with neurofibromatosis type 1 (NF1). Current treatment modalities have been largely ineffective, resulting in a high rate of MPNST recurrence and poor five-year patient survival. This necessitates the exploration of alternative chemotherapeutic options for MPNST patients.

Surviving change: the metabolic journey of hematopoietic stem cells.

Hematopoietic stem cells (HSCs) are a rare population of somatic stem cells that maintain blood production and are uniquely wired to adapt to diverse cellular fates during the lifetime of an organism. Recent studies have highlighted a central role for metabolic plasticity in facilitating cell fate transitions and in preserving HSC functionality and survival. This review summarizes our current understanding of the metabolic programs associated with HSC quiescence, self-renewal, and lineage commitment, and highlights the mechanistic underpinnings of these changing bioenergetics programs.

Neuregulin-1 overexpression and Trp53 haploinsufficiency cooperatively promote de novo malignant peripheral nerve sheath tumor pathogenesis.

Malignant peripheral nerve sheath tumors (MPNSTs) are Schwann cell-derived malignancies that arise from plexiform neurofibromas in patients with mutation of the neurofibromin 1 (NF1) gene. We have shown that the growth factor neuregulin-1 (NRG1) also contributes to human neurofibroma and MPNST pathogenesis and that outbred C57BL/6J × SJL/J transgenic mice overexpressing NRG1 in Schwann cells (P0-GGFβ3 mice) recapitulate the process of neurofibroma-MPNST progression. However, it is unclear whether NRG1 acts predominantly within NF1-regulated signaling cascades or instead activates other essential cascades that cooperate with NF1 loss to promote tumorigenesis.

Protector turns predator: Autophagic death via selective degradation of KRAS.

Therapy-induced autophagy is recognized as a critical determinant of treatment outcome in cancer patients, primarily as a factor underlying drug resistance. However, recent investigations point toward a context-dependent, death-inducing role for autophagy, the mechanism of which remains largely unknown. Our recent study provides evidence that autophagy can directly mediate cell killing in multiple tumor cell types by facilitating degradation of KRAS/K-Ras, a key survival protein.

4-Hydroxytamoxifen induces autophagic death through K-Ras degradation.

Tamoxifen is widely used to treat estrogen receptor-positive breast cancer. Recent findings that tamoxifen and its derivative 4-hydroxytamoxifen (OHT) can exert estrogen receptor-independent cytotoxic effects have prompted the initiation of clinical trials to evaluate its use in estrogen receptor-negative malignancies. For example, tamoxifen and OHT exert cytotoxic effects in malignant peripheral nerve sheath tumors (MPNST) where estrogen is not involved.

Redirected Touching: Training and Adaptation in Warped Virtual Spaces.

is a technique in which virtual space is warped to map many virtual objects onto one real object that serves as a passive haptic prop. Recent work suggests that this mapping can often be predictably unnoticeable and have little effect on task performance. We investigated training and adaptation on a rapid aiming task in a real environment, an unwarped virtual environment, and a warped virtual environment.

The pan erbB inhibitor PD168393 enhances lysosomal dysfunction-induced apoptotic death in malignant peripheral nerve sheath tumor cells.

Malignant peripheral nerve sheath tumors (MPNSTs) are rapidly progressive Schwann cell neoplasms. The erbB family of membrane tyrosine kinases has been implicated in MPNST mitogenesis and invasion and, thus, is a potential therapeutic target. However, tyrosine kinase inhibitors (TKIs) used alone have limited tumoricidal activity.

Autophagy in brain tumors: a new target for therapeutic intervention.

The role of autophagy, traditionally considered a cellular homeostatic and recycling mechanism, has expanded dramatically to include an involvement in discrete stages of tumor initiation and development. Gliomas are the most aggressive and also the most common brain malignancies. Current treatment modalities have only a modest effect on patient outcomes.

Reconstitution of CD4 T cells in bronchoalveolar lavage fluid after initiation of highly active antiretroviral therapy.

The massive depletion of gastrointestinal-tract CD4 T cells is a hallmark of the acute phase of HIV infection. In contrast, the depletion of the lower-respiratory-tract mucosal CD4 T cells as measured in bronchoalveolar lavage (BAL) fluid is more moderate and similar to the depletion of CD4 T cells observed in peripheral blood (PB). To understand better the dynamics of disease pathogenesis and the potential for the reconstitution of CD4 T cells in the lung and PB following the administration of effective antiretroviral therapy, we studied cell-associated viral loads, CD4 T-cell frequencies, and phenotypic and functional profiles of antigen-specific CD4 T cells from BAL fluid and blood before and after the initiation of highly active antiretroviral therapy (HAART).

Chloroquine-induced autophagic vacuole accumulation and cell death in glioma cells is p53 independent.

Glioblastoma (GBM) is a high-grade central nervous system malignancy and despite aggressive treatment strategies, GBM patients have a median survival time of just 1 year. Chloroquine (CQ), an antimalarial lysosomotropic agent, has been identified as a potential adjuvant in the treatment regimen of GBMs. However, the mechanism of CQ-induced tumor cell death is poorly defined.

Autophagy: cerebral home cooking.

Cell survival depends on a complex interplay of processes including homeostatic pathways and cytoprotective mechanisms. Autophagy is a physiological process involved in the basal turnover of long-lived proteins and organelles and also comprises an integral part of the cellular stress response. The significance of autophagy in regulating neural cell fate has become increasingly recognized and agents targeting autophagy are of increasing therapeutic interest.

High frequencies of polyfunctional HIV-specific T cells are associated with preservation of mucosal CD4 T cells in bronchoalveolar lavage.

The mechanisms underlying the massive gastrointestinal tract CD4 T-cell depletion in human immunodeficiency virus (HIV) infection are not well understood nor is it clear whether similar depletion is manifest at other mucosal surfaces. Studies of T-cell and virus dynamics in different anatomical sites have begun to illuminate the pathogenesis of HIV-associated disease. Here, we studied depletion and HIV infection frequencies of CD4 T cells from the gastrointestinal tract, bronchoalveolar lavage (BAL), and blood with the frequencies and functional profiles of HIV-specific T cells in these anatomically distinct sites in HIV-infected individuals.

Do the physical characteristics of a virtual reality device contraindicate its use for balance assessment?

Context: Virtual reality environments may allow researchers to investigate functional balance performance without risks associated with testing in the real world.

Objective: To investigate the effects of the mass of a head-mounted display (HMD) on balance performance.

Design: Counterbalanced pretest-posttest.

Functional impairment of CD4 T cells despite normalization of T cell number in HIV.

Using an in vitro model, we demonstrate that when CD4 T cells from HIV infected subjects are enriched from total blood lymphocytes the immune response to antigen is augmented. However, augmentation of this response is confined to HIV infected subjects with relatively preserved CD4 T cell counts. Enriching for CD4 T cells had no effect on antigen responses in patients with low CD4 lymphocyte counts.

Cytometric analysis of BAL T cells labeled with a standardized antibody cocktail correlates with immunohistochemical staining.

Background: Determining T-cell phenotypes of lung cells obtained by bronchoalveolar lavage (BAL) is frequently clinically useful, particularly for evaluating causes of interstitial lung disease. The current standard of determining CD4/CD8 T-cell subsets by immunohistochemical (IHC) staining of cytocentrifuge slides is labor-intensive and subject to interpreter variation. Flow cytometry (FCM) is a precise and rapid method commonly used in research to characterize cells in the lung.

Impaired cell surface expression of human CD1d by the formation of an HIV-1 Nef/CD1d complex.

The HIV-1 Nef protein causes a decrease in major histocompatibility complex (MHC) class I and CD4 molecule expression on the cell surface. To determine if Nef can affect components of the innate immune response, we assessed the ability of Nef to alter the cell surface expression of human CD1d. In cells co-expressing CD1d and Nef, a substantial reduction in the cell surface level of CD1d was observed, with a concomitant reduction in the activation of CD1d-restricted NKT cells.

CD4+CD28-T cells are expanded in sarcoidosis.

Background And Aim: A subset of CD4+ lymphocytes lacking CD28, an important costimulatory molecule, is increased in certain inflammatory conditions. However, studies have not directly studied CD4+CD28-lymphocytes in patients with chronic sarcoidosis. The aim of this study was to further characterize the CD4+CD28-T cell population in patients with sarcoidosis, particularly those with active disease.