1,013 research outputs found
The cost of promiscuity: sexual transmission of Nosema microsporidian parasites in polyandrous honey bees
Multiple mating (and insemination) by females with different males, polyandry, is widespread across animals, due to material and/or genetic benefits for females. It reaches particularly high levels in some social insects, in which queens can produce significantly fitter colonies by being polyandrous. It is therefore a paradox that two thirds of eusocial hymenopteran insects appear to be exclusively monandrous, in spite of the fitness benefits that polyandry could provide. One possible cost of polyandry could be sexually transmitted parasites, but evidence for these in social insects is extremely limited. Here we show that two different species of Nosema microsporidian parasites can transmit sexually in the honey bee Apis mellifera. Honey bee males that are infected by the parasite have Nosema spores in their semen, and queens artificially inseminated with either Nosema spores or the semen of Nosema-infected males became infected by the parasite. The emergent and more virulent N. ceranae achieved much higher rates of infection following insemination than did N. apis. The results provide the first quantitative evidence of a sexually transmitted disease (STD) in social insects, indicating that STDs may represent a potential cost of polyandry in social insects
Free energies of binding of R- and S-propranolol to wild-type and F483A mutant cytochrome P450 2D6 from molecular dynamics simulations
Detailed molecular dynamics (MD) simulations have been performed to reproduce and rationalize the experimental finding that the F483A mutant of CYP2D6 has lower affinity for R-propranolol than for S-propranolol. Wild-type (WT) CYP2D6 does not show this stereospecificity. Four different approaches to calculate the free energy differences have been investigated and were compared to the experimental binding data. From the differences between calculations based on forward and backward processes and the closure of thermodynamic cycles, it was clear that not all simulations converged sufficiently. The approach that calculates the free energies of exchanging R-propranolol with S-propranolol in the F483A mutant relative to the exchange free energy in WT CYP2D6 accurately reproduced the experimental binding data. Careful inspection of the end-points of the MD simulations involved in this approach, allowed for a molecular interpretation of the observed differences
Optimisation of the RT-PCR detection of immunomagnetically enriched carcinoma cells
BACKGROUND: Immunomagnetic enrichment followed by RT-PCR (immunobead RT-PCR) is an efficient methodology to identify disseminated carcinoma cells in the blood and bone marrow. The RT-PCR assays must be both specific for the tumor cells and sufficiently sensitive to enable detection of single tumor cells. We have developed a method to test RT-PCR assays for any cancer. This has been investigated using a panel of RT-PCR markers suitable for the detection of breast cancer cells. METHODS: In the assay, a single cell line-derived tumor cell is added to 100 peripheral blood mononuclear cells (PBMNCs) after which mRNA is isolated and reverse transcribed for RT-PCR analysis. PBMNCs without added tumor cells are used as specificity controls. The previously studied markers epidermal growth factor receptor (EGFR), mammaglobin 1 (MGB1), epithelial cell adhesion molecule (EpCAM/TACSTD1), mucin 1 (MUC1), carcinoembryonic antigen (CEA) were tested. Two new epithelial-specific markers ELF3 and EphB4 were also tested. RESULTS: MUC1 was unsuitable as strong amplification was detected in 100 cell PBMNC controls. Expression of ELF3, EphB4, EpCAM, EGFR, CEA and MGB1 was found to be both specific for the tumor cell, as demonstrated by the absence of a signal in most 100 cell PBMNC controls, and sensitive enough to detect a single tumor cell in 100 PBMNCs using a single round of RT-PCR. CONCLUSIONS: ELF3, EphB4, EpCAM, EGFR, CEA and MGB1 are appropriate RT-PCR markers for use in a marker panel to detect disseminated breast cancer cells after immunomagnetic enrichment
The effect of acute exercise on glycogen synthesis rate in obese subjects studied by 13C MRS
In obesity, insulin-stimulated glucose uptake in skeletal muscle is decreased. We investigated whether the stimulatory effect of acute exercise on glucose uptake and subsequent glycogen synthesis was normal. The study was performed on 18 healthy volunteers, 9 obese (BMIΒ =Β 32.6Β Β±Β 1.2Β kg/m2, meanΒ Β±Β SEM) and 9 lean (BMIΒ =Β 22.0Β Β±Β 0.9Β kg/m2), matched for age and gender. All participants underwent a euglycemic hyperinsulinemic clamp, showing reduced glucose uptake in the obese group (PΒ =Β 0.01), during which they performed a short intense local exercise (single-legged toe lifting). Dynamic glucose incorporation into glycogen in the gastrocnemius muscle before and after exercise was assessed by 13C magnetic resonance spectroscopy combined with infusion of [1-13C]glucose. Blood flow was measured to investigate its potential contribution to glucose uptake. Before exercise, glycogen synthesis rate tended to be lower in obese subjects compared with lean (78Β Β±Β 14 vs. 132Β Β±Β 24Β ΞΌmol/kg muscle/min; PΒ =Β 0.07). Exercise induced highly significant rises in glycogen synthesis rates in both groups, but the increase in obese subjects was reduced compared with lean (112Β Β±Β 15 vs. 186Β Β±Β 27Β ΞΌmol/kg muscle/min; PΒ =Β 0.03), although the relative increase was similar (184Β Β±Β 35 vs. 202Β Β±Β 51%; PΒ =Β 0.78). After exercise, blood flow increased equally in both groups, without a temporal relationship with the rate of glycogen synthesis. In conclusion, this study shows a stimulatory effect of a short bout of acute exercise on insulin-induced glycogen synthesis rate that is reduced in absolute values but similar in percentages in obese subjects. These results suggest a shared pathway between insulin- and exercise-induced glucose uptake and subsequent glycogen synthesis
The PROgnostic Value of unrequested Information in Diagnostic Imaging (PROVIDI) Study: rationale and design
We describe the rationale for a new study examining the prognostic value of unrequested findings in diagnostic imaging. The deployment of more advanced imaging modalities in routine care means that such findings are being detected with increasing frequency. However, as the prognostic significance of many types of unrequested findings is unknown, the optimal response to such findings remains uncertain and in many cases an overly defensive approach is adopted, to the detriment of patient-care. Additionally, novel and promising image findings that are newly available on many routine scans cannot be used to improve patient care until their prognostic value is properly determined. The PROVIDI study seeks to address these issues using an innovative multi-center case-cohort study design. PROVIDI is to consist of a series of studies investigating specific, selected disease entities and clusters. Computed Tomography images from the participating hospitals are reviewed for unrequested findings. Subsequently, this data is pooled with outcome data from a central population registry. Study populations consist of patients with endpoints relevant to the (group of) disease(s) under study along with a random control sample from the cohort. This innovative design allows PROVIDI to evaluate selected unrequested image findings for their true prognostic value in a series of manageable studies. By incorporating unrequested image findings and outcomes data relevant to patients, truly meaningful conclusions about the prognostic value of unrequested and emerging image findings can be reached and used to improve patient-care
ΠΡΡΠ²Π»Π΅Π½ΠΈΠ΅ ΠΏΠΎΠ½ΡΡΠΈΠΉ ΠΈ ΠΈΡ Π²Π·Π°ΠΈΠΌΠΎΡΠ²ΡΠ·Π΅ΠΉ Π² ΡΠ°ΠΌΠΊΠ°Ρ ΡΠ΅Ρ Π½ΠΎΠ»ΠΎΠ³ΠΈΠΈ ΠΊΠΎΠ½ΡΠ΅Π½Ρ-ΠΌΠΎΠ½ΠΈΡΠΎΡΠΈΠ½Π³Π°
ΠΡΠΈΠ²Π΅Π΄Π΅Π½Ρ ΠΏΠΎΠ΄Ρ
ΠΎΠ΄Ρ ΠΊ ΡΠ΅ΡΠ΅Π½ΠΈΡ ΠΏΡΠΎΠ±Π»Π΅ΠΌΡ Π²ΡΡΠ²Π»Π΅Π½ΠΈΡ ΡΠ°ΠΊΡΠΎΠ³ΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΎΠΉ ΠΈΠ½ΡΠΎΡΠΌΠ°ΡΠΈΠΈ ΠΈΠ· Π½Π΅ΡΡΡΡΠΊΡΡΡΠΈΡΠΎΠ²Π°Π½Π½ΡΡ
ΡΠ΅ΠΊΡΡΠΎΠ²ΡΡ
ΠΏΠΎΡΠΎΠΊΠΎΠ². ΠΠΏΠΈΡΠ°Π½Ρ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΠΈΡΠ΅ΡΠΊΠΈΠ΅ ΡΠ΅ΡΠ΅Π½ΠΈΡ, ΠΏΠΎΠ·Π²ΠΎΠ»ΡΡΡΠΈΠ΅ ΠΈΠ·Π²Π»Π΅ΠΊΠ°ΡΡ ΠΈΠ· ΠΏΠΎΠ»Π½ΠΎΡΠ΅ΠΊΡΡΠΎΠ²ΡΡ
Π΄ΠΎΠΊΡΠΌΠ΅Π½ΡΠΎΠ² ΡΠ°ΠΊΠΈΠ΅ ΠΏΠΎΠ½ΡΡΠΈΡ ΠΊΠ°ΠΊ ΡΠΈΡΠΌΡ, ΡΠ°ΠΌΠΈΠ»ΠΈΠΈ, Π³Π΅ΠΎΠ³ΡΠ°ΡΠΈΡΠ΅ΡΠΊΠΈΠ΅ Π½Π°Π·Π²Π°Π½ΠΈΡ ΠΈ Ρ.ΠΏ., Π° ΡΠ°ΠΊΠΆΠ΅ Π²ΡΡΠ²Π»ΡΡΡ ΡΠΈΠ»Ρ ΠΈΡ
Π²Π·Π°ΠΈΠΌΠΎΡΠ²ΡΠ·Π΅ΠΉ Π½Π° ΠΎΡΠ½ΠΎΠ²Π΅ ΠΏΡΠΈΠΌΠ΅Π½Π΅Π½ΠΈΡ Π΄Π²ΡΡ
Π°Π»Π³ΠΎΡΠΈΡΠΌΠΎΠ². ΠΠ΅ΡΠ²ΡΠΉ ΠΈΠ· ΡΡΠΈΡ
Π°Π»Π³ΠΎΡΠΈΡΠΌΠΎΠ² ΠΎΡΠ½ΠΎΠ²ΡΠ²Π°Π΅ΡΡΡ Π½Π° ΡΡΠ΅ΡΠ΅ ΡΠΎΠ²ΠΌΠ΅ΡΡΠ½ΠΎΠ³ΠΎ Π²Ρ
ΠΎΠΆΠ΄Π΅Π½ΠΈΡ ΠΏΠΎΠ½ΡΡΠΈΠΉ Π² ΠΎΠ΄Π½ΠΈ ΠΈ ΡΠ΅ ΠΆΠ΅ Π΄ΠΎΠΊΡΠΌΠ΅Π½ΡΡ, Π° Π²ΡΠΎΡΠΎΠΉ Π½Π° ΡΡΠ΅ΡΠ΅ ΠΎΠ±ΡΠ΅Π³ΠΎ Π΄Π»Ρ ΡΠ°ΡΡΠΌΠ°ΡΡΠΈΠ²Π°Π΅ΠΌΡΡ
ΠΏΠΎΠ½ΡΡΠΈΠΉ ΠΊΠΎΠ½ΡΠ΅ΠΊΡΡΠ°.ΠΠ°Π²Π΅Π΄Π΅Π½ΠΎ ΠΏΡΠ΄Ρ
ΠΎΠ΄ΠΈ Π΄ΠΎ Π²ΠΈΡΡΡΠ΅Π½Π½Ρ ΠΏΡΠΎΠ±Π»Π΅ΠΌΠΈ Π²ΠΈΡΠ²Π»Π΅Π½Π½Ρ ΡΠ°ΠΊΡΠΎΠ³ΡΠ°ΡΡΡΠ½ΠΎΡ ΡΠ½ΡΠΎΡΠΌΠ°ΡΡΡ Π· Π½Π΅ΡΡΡΡΠΊΡΡΡΠΎΠ²Π°Π½ΠΈΡ
ΡΠ΅ΠΊΡΡΠΎΠ²ΠΈΡ
ΠΏΠΎΡΠΎΠΊΡΠ². ΠΠΏΠΈΡΠ°Π½ΠΎ ΡΠ΅Ρ
Π½ΠΎΠ»ΠΎΠ³ΡΡΠ½Ρ ΡΡΡΠ΅Π½Π½Ρ, ΡΠΎ Π΄ΠΎΠ·Π²ΠΎΠ»ΡΡΡΡ Π΄ΠΎΠ±ΡΡΠΈ Π· ΠΏΠΎΠ²Π½ΠΎΡΠ΅ΠΊΡΡΠΎΠ²ΠΈΡ
Π΄ΠΎΠΊΡΠΌΠ΅Π½ΡΡΠ² ΡΠ°ΠΊΡ ΠΏΠΎΠ½ΡΡΡΡ ΡΠΊ ΡΡΡΠΌΠΈ, ΠΏΡΡΠ·Π²ΠΈΡΠ°, Π³Π΅ΠΎΠ³ΡΠ°ΡΡΡΠ½Ρ Π½Π°Π·Π²ΠΈ ΡΠΎΡΠΎ, Π° ΡΠ°ΠΊΠΎΠΆ Π²ΠΈΡΠ²Π»ΡΡΠΈ ΡΠΈΠ»Ρ ΡΡ
Π½ΡΡ
Π²Π·Π°ΡΠΌΠΎΠ·Π²βΡΠ·ΠΊΡΠ² Π½Π° Π±Π°Π·Ρ Π·Π°ΡΡΠΎΡΡΠ²Π°Π½Π½Ρ Π΄Π²ΠΎΡ
Π°Π»Π³ΠΎΡΠΈΡΠΌΡΠ². ΠΠ΅ΡΡΠΈΠΉ Π· ΡΠΈΡ
Π°Π»Π³ΠΎΡΠΈΡΠΌΡΠ² Π±Π°Π·ΡΡΡΡΡΡ Π½Π° Π²ΡΠ°Ρ
ΡΠ²Π°Π½Π½Ρ ΡΠΏΡΠ»ΡΠ½ΠΎΠ³ΠΎ Π²Ρ
ΠΎΠ΄ΠΆΠ΅Π½Π½Ρ ΠΏΠΎΠ½ΡΡΡ Π΄ΠΎ ΠΎΠ΄Π½ΠΈΡ
Ρ ΡΠΈΡ
ΡΠ°ΠΌΠΈΡ
Π΄ΠΎΠΊΡΠΌΠ΅Π½ΡΡΠ², Π° Π΄ΡΡΠ³ΠΈΠΉ β Π½Π° Π²ΡΠ°Ρ
ΡΠ²Π°Π½Π½Ρ Π·Π°Π³Π°Π»ΡΠ½ΠΎΠ³ΠΎ Π΄Π»Ρ ΠΏΠΎΠ½ΡΡΡ, ΡΠΎ ΡΠΎΠ·Π³Π»ΡΠ΄Π°ΡΡΡΡΡ, ΠΊΠΎΠ½ΡΠ΅ΠΊΡΡΡ.Approaches to the solution of a problem of revealing factual information from unstructured text flows are given. The technological solutions, allowing to take from text-through documents such concepts as a firm, a surname, place names, etc., and also to reveal force of their interrelations on the basis of application of two algorithms are described. The first of these algorithms is based on the account of joint concepts occurrence in the same documents, and the second one on the account of the context common for considered concepts
Frontal-to-Parietal Top-Down Causal Streams along the Dorsal Attention Network Exclusively Mediate Voluntary Orienting of Attention
Previous effective connectivity analyses of functional magnetic resonance imaging (fMRI) have revealed dynamic causal streams along the dorsal attention network (DAN) during voluntary attentional control in the human brain. During resting state, however, fMRI has shown that the DAN is also intrinsically configured by functional connectivity, even in the absence of explicit task demands, and that may conflict with effective connectivity studies. To resolve this contradiction, we performed an effective connectivity analysis based on partial Granger causality (pGC) on event-related fMRI data during Posner's cueing paradigm while optimizing experimental and imaging parameters for pGC analysis. Analysis by pGC can factor out exogenous or latent influences due to unmeasured variables. Typical regions along the DAN with greater activation during orienting than withholding of attention were selected as regions of interest (ROIs). pGC analysis on fMRI data from the ROIs showed that frontal-to-parietal top-down causal streams along the DAN appeared during (voluntary) orienting, but not during other, less-attentive and/or resting-like conditions. These results demonstrate that these causal streams along the DAN exclusively mediate voluntary covert orienting. These findings suggest that neural representations of attention in frontal regions are at the top of the hierarchy of the DAN for embodying voluntary attentional control
Identification of a Siglec-F+ granulocyte-macrophage progenitor
In recent years multi-parameter flow cytometry has enabled identification of cells at major stages in myeloid development; from pluripotent hematopoietic stem cells, through populations with increasingly limited developmental potential (common myeloid progenitors and granulocyte-macrophage progenitors), to terminally differentiated mature cells. Myeloid progenitors are heterogeneous, and the surface markers that define transition states from progenitors to mature cells are poorly characterized. Siglec-F is a surface glycoprotein frequently used in combination with IL-5 receptor alpha (IL5RΞ±) for the identification of murine eosinophils. Here, we describe a CD11b+ Siglec-F+ IL5RΞ±- myeloid population in the bone marrow of C57BL/6 mice. The CD11b+ Siglec-F+ IL5RΞ±- cells are retained in eosinophil deficient PHIL mice, and are not expanded upon overexpression of IL-5, indicating that they are upstream or independent of the eosinophil lineage. We show these cells to have GMP-like developmental potential in vitro and in vivo, and to be transcriptionally distinct from the classically described GMP population. The CD11b+ Siglec-F+ IL5RΞ±- population expands in the bone marrow of Myb mutant mice, which is potentially due to negative transcriptional regulation of Siglec-F by Myb. Lastly, we show that the role of Siglec-F may be, at least in part, to regulate GMP viability
Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV
The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of βs = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pTβ₯20 GeV and pseudorapidities {pipe}Ξ·{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}Ξ·{pipe}<0. 8) for jets with 60β€pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2β€{pipe}Ξ·{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. Β© 2013 CERN for the benefit of the ATLAS collaboration
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