368 research outputs found
Susceptibility of biological stages of the horn fly, Haematobia irritans, to entomopathogenic fungi (Hyphomycetes)
The susceptibility of the egg, pupa, and adult of Haematobia irritans (L.) (Diptera: Muscidae) to isolates of the fungi Metarhizium anisopliae (Metsch.) Sor., Beauveria bassiana (Bals.) Vuill., and Paecilomyces fumosoroseus (Wize) Brown and Smith, was evaluated under laboratory conditions. Groups of 20 eggs than 4 h old, pupae less than 48h old and adults were sprayed with a conidial suspension of each isolate. Eggs, pupae and adults of horn fly were susceptible to these entomopathogenic fungi. For treated eggs, the isolates Ma3, Ma 15, Ma25, Pfr1, and Pfr8 reduced adult emergence to 3.8% to 6.3% in comparison with the control (72%). The mortality of pupae infected by the isolates Ma2, Ma25, and Pfr10 ranged between 50% and 71.3%. Mortality of adults after treatment with the isolates Ma6, Ma 10, Ma 14, Ma 15, Pfr 1, Pfr 9, Pfr 10, Pfr 11, and Pfr12 were higher than 90%. The isolate Ma6 produced the lowest LC(50) against adult horn flies (8.08 × 10(2)conidia/ml). These findings supported the hypotheses that isolates of M. anisopliae, and P. fumosoroseus are pathogenic against the different biological stages of horn flies by reducing adult emergence when applied on groups of eggs and pupae, and producing mortality when applied to adults
Analysis of radiation-induced cell death in head and neck squamous cell carcinoma and rat liver maintained in microfluidic devices
Objective The aim of this study was to investigate how head and neck squamous cell carcinoma (HNSCC) tissue biopsies maintained in a pseudo in vivo environment within a bespoke microfluidic device respond to radiation treatment. Study Design Feasibility study. Setting Tertiary referral center. Subjects and Methods Thirty-five patients with HNSCC were recruited, and liver tissue from 5 Wistar rats was obtained. A microfluidic device was used to maintain the tissue biopsy samples in a viable state. Rat liver was used to optimize the methodology. HNSCC was obtained from patients with T1-T3 laryngeal or oropharyngeal SCC; N1-N2 metastatic cervical lymph nodes were also obtained. Irradiation consisted of single doses of between 2 Gy and 40 Gy and a fractionated course of 5×2 Gy. Cell death was assessed in the tissue effluent using the soluble markers lactate dehydrogenase (LDH) and cytochrome c and in the tissue by immunohistochemical detection of cleaved cytokeratin18 (M30 antibody). Results A significant surge in LDH release was demonstrated in the rat liver after a single dose of 20 Gy; in HNSCC, it was seen after 40 Gy compared with the control. There was no significant difference in cytochrome c release after 5 Gy or 10 Gy. M30 demonstrated a dose-dependent increase in apoptotic index for a given increase in single-dose radiotherapy. There was a significant increase in apoptotic index between 1×2 Gy and 5×2 Gy. Conclusion M30 is a superior method compared with soluble markers in detecting low-dose radiation-induced cell death. This microfluidic technique can be used to assess radiation-induced cell death in HNSCC and therefore has the potential to be used to predict radiation response
The biology and behavior of the longhorned beetle, Dectes texanus on sunflower and soybean
The biology and behavior of the longhorned beetle Dectes texanus LeConte (Coleoptera: Cerambycidae) was studied on two host plants that suffer economic losses from this pest; sunflower, Helianthus annuus, and soybean, Glycines max. Reciprocal crosses of D. texanus collected from the two plants all produced viable progeny, indicating that conspecific insects attack both crops. Pupae from soybean stalks weighed about 40% less than those from sunflower, and adults fed on soybean lived a mean of 23 days, compared to a mean of 53 days (males) and 76 days (females) for those fed sunflower. A female's larval host plant had no effect on her tendency to ovipuncture plants of either type in a greenhouse trial. A field-tested population collected exclusively from sunflower contained three types of females in similar proportions: those that laid eggs only on sunflower, those that laid only on soybean, and those that laid equally on both host plants. Females in field trials fed more on the plant they had fed on in the laboratory, but soybean-fed females fed more on soybean than did sunflower-fed females. Females fed soybean also made more ovipunctures on soybean plants in field trials than sunflower-fed females, but their responses to sunflower plants were similar. Females displayed higher total ovipositional activity when they encountered sunflower first in the field, and lower total activity when they encountered soybean first. Feeding scores were significantly correlated with ovipunctures and eggs on both plant types. We conclude that sunflower is the preferred host plant, although females will accept soybean when it is the only available food. The results suggest that D. texanus is still in the initial stages of a host range expansion with female host selection behavior demonstrating both genetic influences and phenotypic flexibility. Sunflower represents a nutritionally superior, ancestral host plant and relatively high fitness costs are still associated with utilization of the novel host plant, soybean, costs that may be offset by benefits such as reduced intraspecific competition. These potential benefits and their consequent implications for D. texanus host range evolution are hypothesized and discussed
On the cohomology of pseudoeffective line bundles
The goal of this survey is to present various results concerning the
cohomology of pseudoeffective line bundles on compact K{\"a}hler manifolds, and
related properties of their multiplier ideal sheaves. In case the curvature is
strictly positive, the prototype is the well known Nadel vanishing theorem,
which is itself a generalized analytic version of the fundamental
Kawamata-Viehweg vanishing theorem of algebraic geometry. We are interested
here in the case where the curvature is merely semipositive in the sense of
currents, and the base manifold is not necessarily projective. In this
situation, one can still obtain interesting information on cohomology, e.g. a
Hard Lefschetz theorem with pseudoeffective coefficients, in the form of a
surjectivity statement for the Lefschetz map. More recently, Junyan Cao, in his
PhD thesis defended in Grenoble, obtained a general K{\"a}hler vanishing
theorem that depends on the concept of numerical dimension of a given
pseudoeffective line bundle. The proof of these results depends in a crucial
way on a general approximation result for closed (1,1)-currents, based on the
use of Bergman kernels, and the related intersection theory of currents.
Another important ingredient is the recent proof by Guan and Zhou of the strong
openness conjecture. As an application, we discuss a structure theorem for
compact K{\"a}hler threefolds without nontrivial subvarieties, following a
joint work with F.Campana and M.Verbitsky. We hope that these notes will serve
as a useful guide to the more detailed and more technical papers in the
literature; in some cases, we provide here substantially simplified proofs and
unifying viewpoints.Comment: 39 pages. This survey is a written account of a lecture given at the
Abel Symposium, Trondheim, July 201
Talin is required for integrin-mediated platelet function in hemostasis and thrombosis
Integrins are critical for hemostasis and thrombosis because they mediate both platelet adhesion and aggregation. Talin is an integrin-binding cytoplasmic adaptor that is a central organizer of focal adhesions, and loss of talin phenocopies integrin deletion in Drosophila. Here, we have examined the role of talin in mammalian integrin function in vivo by selectively disrupting the talin1 gene in mouse platelet precursor megakaryocytes. Talin null megakaryocytes produced circulating platelets that exhibited normal morphology yet manifested profoundly impaired hemostatic function. Specifically, platelet-specific deletion of talin1 led to spontaneous hemorrhage and pathological bleeding. Ex vivo and in vitro studies revealed that loss of talin1 resulted in dramatically impaired integrin αIIbβ3-mediated platelet aggregation and β1 integrin–mediated platelet adhesion. Furthermore, loss of talin1 strongly inhibited the activation of platelet β1 and β3 integrins in response to platelet agonists. These data establish that platelet talin plays a crucial role in hemostasis and provide the first proof that talin is required for the activation and function of mammalian α2β1 and αIIbβ3 integrins in vivo
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Hematopoietic Cell Transplantation in Patients With Primary Immune Regulatory Disorders (PIRD): A Primary Immune Deficiency Treatment Consortium (PIDTC) Survey.
Primary Immune Regulatory Disorders (PIRD) are an expanding group of diseases caused by gene defects in several different immune pathways, such as regulatory T cell function. Patients with PIRD develop clinical manifestations associated with diminished and exaggerated immune responses. Management of these patients is complicated; oftentimes immunosuppressive therapies are insufficient, and patients may require hematopoietic cell transplant (HCT) for treatment. Analysis of HCT data in PIRD patients have previously focused on a single gene defect. This study surveyed transplanted patients with a phenotypic clinical picture consistent with PIRD treated in 33 Primary Immune Deficiency Treatment Consortium centers and European centers. Our data showed that PIRD patients often had immunodeficient and autoimmune features affecting multiple organ systems. Transplantation resulted in resolution of disease manifestations in more than half of the patients with an overall 5-years survival of 67%. This study, the first to encompass disorders across the PIRD spectrum, highlights the need for further research in PIRD management
The High-Acceptance Dielectron Spectrometer HADES
HADES is a versatile magnetic spectrometer aimed at studying dielectron
production in pion, proton and heavy-ion induced collisions. Its main features
include a ring imaging gas Cherenkov detector for electron-hadron
discrimination, a tracking system consisting of a set of 6 superconducting
coils producing a toroidal field and drift chambers and a multiplicity and
electron trigger array for additional electron-hadron discrimination and event
characterization. A two-stage trigger system enhances events containing
electrons. The physics program is focused on the investigation of hadron
properties in nuclei and in the hot and dense hadronic matter. The detector
system is characterized by an 85% azimuthal coverage over a polar angle
interval from 18 to 85 degree, a single electron efficiency of 50% and a vector
meson mass resolution of 2.5%. Identification of pions, kaons and protons is
achieved combining time-of-flight and energy loss measurements over a large
momentum range. This paper describes the main features and the performance of
the detector system
Longitudinal cytokine profiling identifies GRO-α and EGF as potential biomarkers of disease progression in Essential Thrombocythemia
Myeloproliferative neoplasms (MPNs) are characterized by deregulation of mature blood cell production and increased risk of myelofibrosis (MF) and leukemic transformation. Numerous driver mutations have been identified but substantial disease heterogeneity remains unexplained, implying the involvement of additional as yet unidentified factors. The inflammatory microenvironment has recently attracted attention as a crucial factor in MPN biology, in particular whether inflammatory cytokines and chemokines contribute to disease establishment or progression. Here we present a large-scale study of serum cytokine profiles in more than 400 MPN patients and identify an essential thrombocythemia (ET)-specific inflammatory cytokine signature consisting of Eotaxin, GRO-α, and EGF. Levels of 2 of these markers (GRO-α and EGF) in ET patients were associated with disease transformation in initial sample collection (GRO-α) or longitudinal sampling (EGF). In ET patients with extensive genomic profiling data (n = 183) cytokine levels added significant prognostic value for predicting transformation from ET to MF. Furthermore, CD56+CD14+ pro-inflammatory monocytes were identified as a novel source of increased GRO-α levels. These data implicate the immune cell microenvironment as a significant player in ET disease evolution and illustrate the utility of cytokines as potential biomarkers for reaching beyond genomic classification for disease stratification and monitoring.The serum cytokine studies were supported by a research grant from the Rosetrees Trust. NFØ was supported by grants from the Danish Lundbeck Foundation and Danish Cancer Society, J.G. was supported by fellowships from Bloodwise and the Kay Kendall Leukaemia Fund; and M.S.S. is the recipient of a Biotechnology and Biological Sciences Research Council Industrial Collaborative Awards in Science and Engineering PhD Studentship. Work in the R.C.S. laboratory was supported by grants from the Stiftung Blutspendezentrum SRK beider Basel, the Swiss National Science Foundation (31003A-147016/1 and 31003A_166613), and the Swiss Cancer League (KLS-2950-02-2012 and KFS-3655-02-2015). A.K. was supported by the Else Kröner-Fresenius Foundation. Work in the A.R.G. laboratory is supported by the Wellcome Trust, Bloodwise, Cancer Research UK, the Kay Kendall Leukaemia Fund, and the Leukemia and Lymphoma Society of America. Work in the D.G.K. laboratory is supported by a Bloodwise Bennett Fellowship (15008), a European Hematology Association Non-Clinical Advanced Research Fellowship, and an ERC Starting Grant (ERC-2016-STG–715371). D.G.K. and A.R.G. are supported by a core support grant from the Wellcome Trust and Medical Research Council to the Wellcome MRC Cambridge Stem Cell Institute, the National Institute for Health Research Cambridge Biomedical Research Centre, and the CRUK Cambridge Cancer Centre
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