379 research outputs found

    CaMKK2 Knockout Bone Marrow Cells Collected/Processed in Low Oxygen (Physioxia) Suggests CaMKK2 as a Hematopoietic Stem to Progenitor Differentiation Fate Determinant

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    Little is known about a regulatory role of CaMKK2 for hematopoietic stem (HSC) and progenitor (HPC) cell function. To assess this, we used Camkk2−/− and wild type (WT) control mouse bone marrow (BM) cells. BM cells were collected/processed and compared under hypoxia (3% oxygen; physioxia) vs. ambient air (~21% oxygen). Subjecting cells collected to ambient air, even for a few minutes, causes a stress that we termed Extra Physiological Shock/Stress (EPHOSS) that causes differentiation of HSCs and HPCs. We consider physioxia collection/processing a more relevant way to assess HSC/HPC numbers and function, as the cells remain in an oxygen tension closer physiologic conditions. Camkk2−/− cells collected/processed at 3% oxygen had positive and negative effects respectively on HSCs (by engraftment using competitive transplantation with congenic donor and competitor cells and lethally irradiated congenic recipient mice), and HPCs (by colony forming assays of CFU-GM, BFU-E, and CFU-GEMM) compared to WT cells processed in ambient air. Thus, with cells collected/processed under physioxia, and therefore never exposed and naïve to ambient air conditions, CaMKK2 not only appears to act as an HSC to HPC differentiation fate determinant, but as we found for other intracellular mediators, the Camkk−/− mouse BM cells were relatively resistant to effects of EPHOSS. This information is of potential use for modulation of WT BM HSCs and HPCs for future clinical advantage. Graphical Abstract: [Figure not available: see fulltext.]

    Assessment of the temperature cut-off point by a commercial intravaginal device to predict parturition in Piedmontese beef cows

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    Dystocic parturitions have an adverse impact on animal productivity and therefore the profitability of the farm. In this regard, accurate prediction of calving is essential since it allows for efficient and prompt assistance of the dam and the calf. Numerous approaches to predict parturition have been studied, among these, measurement of intravaginal temperature (IVT) is the most effective method at the field level. Thus, objectives of this experiment were, 1) to find an IVT cut-off to predict calving within 24 h, and 2) to clarify the use of IVT as an automated method of calving detection in housed beef cows. A commercial intravaginal electronic device (Medria Vel'Phone\uae) with a sensor that measures the IVT every 12 h was used. Piedmontese cows (n = 211; 27 primiparous and 184 multiparous) were included in this study. One-way analysis of variance was used to assess the temperature differences at 0, 12, 24, 36, 48 and 60 h before parturition. Receiving operator characteristic curves were built to determine the temperature cut-off which predicts calving within 24 h with the highest summation of sensitivity (Se) and specificity (Sp). Binomial logistic regression models were computed to identify factors that may affect the IVT before calving. Mean gestation length was 291.5 \ub1 13.7 d (primiparous, 292 \ub1 14.1 d; multiparous, 289 \ub1 9.2 d). A decrease (P < 0.001) in the average IVT was found from 60 h before calving until the expulsion of the IVT device. A significant (P < 0.05) reduction in the IVT was noticeable from 24 h before until parturition. The IVT drop to predict parturition 24 h before calving was 0.21 \ub0C (area under the curve [AUC] = 0.72; Se = 66%, Sp = 76%). Furthermore, the IVT cut-off value to predict parturition within 24 h was 38.2 \ub0C (AUC = 0.89; Se = 86%, Sp = 91%). None of the evaluated fixed effects (parity, dystocia, season or length of gestation) affected (P \u2c3 0.05) the IVT variation from 60 h before and up to calving. To conclude, the IVT average seems to be a better parameter than the drop in temperature to predict parturition within 24 h. In this regard, a cut-off of 38.2 \ub0C showed a high Se and Sp for predicting calving. This study demonstrates the usefulness of a commercially available device to predict calving to improve management in stabled beef farms

    Minimal Anomalous U(1)' Extension of the MSSM

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    We study an extension of the MSSM by an anomalous abelian vector multiplet and a St\"uckelberg multiplet. The anomalies are cancelled by the Green-Schwarz mechanism and the addition of Chern-Simons terms. The advantage of this choice over the standard one is that it allows for arbitrary values of the quantum numbers of the extra U(1). As a first step towards the study of hadron annihilations producing four leptons in the final state (a clean signal which might be studied at LHC) we then compute the decays Z'\to Z_0 \g and Z′→Z0Z0Z'\to Z_0 Z_0. We find that the largest values of the decay rate is ∼10−4\sim 10^{-4} GeV, while the expected number of events per year at LHC is at most of the order of 10.Comment: 45 pages, 8 eps figures, feynmf. Phenomenological section expanded. 2 plots and references adde

    St\"uckelino Dark Matter in Anomalous U(1)' Models

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    We study a possible dark matter candidate in the framework of a minimal anomalous U(1)′U(1)' extension of the MSSM. It turns out that in a suitable decoupling limit the St\"uckelino, the fermionic degree of freedom of the St\"uckelberg multiplet, is the lightest supersymmetric particle (LSP). We compute the relic density of this particle including coannihilations with the next to lightest supersymmetric particle (NLSP) and with the next to next to lightest supersymmetric particle (NNLSP) which are assumed almost degenerate in mass. This assumption is needed in order to satisfy the stringent limits that the Wilkinson Microwave Anisotropy Probe (WMAP) puts on the relic density. We find that the WMAP constraints can be satisifed by different NLSP and NNLSP configurations as a function of the mass gap with the LSP. These results hold in the parameter space region where the model remains perturbative.Comment: 21 pages, 6 figures, improved section 5, revised version published on EPJ

    Fasciola hepatica en búfalos de la Provincia de Corrientes, Argentina

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    Fasciola hepática (Trematoda: Digenea) es el agente etiológico de la fasciolosis de los bóvidos. En la región el parásito causa pérdidas por decomiso de hígados y falta de rendimiento productivo de los animales afectados. La enfermedad está supeditada a la presencia de huéspedes intermediarios, caracoles pulmonados de la familia Lymnaeidae, cuyas poblaciones prosperan en ambientes acuáticos. En la Provincia de Corrientes la enfermedad se conoce desde hace mucho tiempo, afectando a bovinos y ovinos; no se hallaron datos referentes al ganado bubalino (Bubalus bubalis). El objetivo de este ensayo fue determinar la presencia del parásito en búfalos de 41 establecimientos ganaderos de diferentes departamentos de la provincia citada, en los cuales existían antecedentes de la enfermedad en bovinos. Durante los años 2005 a 2008 fueron relevados respectivamente 11, 14 y 16 establecimientos bubalinos (en total 1.200 búfalos de distintos sexos y edades), obteniéndose resultados positivos en once establecimientos (26,8%). Se refrenda que la fasciolosis aparece cuando los búfalos son introducidos en lugares ocupados previamente por bovinos infestados con F. hepatica

    Calcium/calmodulin-dependent kinase kinase 2 regulates hematopoietic stem and progenitor cell regeneration

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    Hematopoietic stem and progenitor cells (HSPCs) are predominantly quiescent in adults, but proliferate in response to bone marrow (BM) injury. Here, we show that deletion of Ca2+/calmodulin (CaM)-dependent protein kinase kinase 2 (CaMKK2) promotes HSPC regeneration and hematopoietic recovery following radiation injury. Using Camkk2-enhanced green fluorescent protein (EGFP) reporter mice, we found that Camkk2 expression is developmentally regulated in HSPC. Deletion of Camkk2 in HSPC results in a significant downregulation of genes affiliated with the quiescent signature. Accordingly, HSPC from Camkk2 null mice have a high proliferative capability when stimulated in vitro in the presence of BM-derived endothelial cells. In addition, Camkk2 null mice are more resistant to radiation injury and show accelerated hematopoietic recovery, enhanced HSPC regeneration and ultimately a prolonged survival following sublethal or lethal total body irradiation. Mechanistically, we propose that CaMKK2 regulates the HSPC response to hematopoietic damage by coupling radiation signaling to activation of the anti-proliferative AMP-activated protein kinase. Finally, we demonstrated that systemic administration of the small molecule CaMKK2 inhibitor, STO-609, to irradiated mice enhanced HSPC recovery and improved survival. These findings identify CaMKK2 as an important regulator of HSPC regeneration and demonstrate CaMKK2 inhibition is a novel approach to promoting hematopoietic recovery after BM injury

    The legacy of Corrado Gini in population studies

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    This volume contains 12 papers that range over many different research subjects, taking in many of the population questions that, directly or indirectly, absorbed Corrado Gini as demographer and social scientist over several decades. They vary from the analysis of the living conditions and behaviours of the growing foreign population (measurements and methods of analysis, socio-economic conditions and health, ethnic residential segregation, sex-ratio at birth), to studies on the homogamy of couples; from population theories (with reference to the cyclical theory of populations) to the modelling approach to estimating mortality in adult ages or estimating time transfers, by age and sex, related to informal child care and adult care; from historical studies that take up themes dear to Gini (such as the estimates of Italian military deaths in WWI), to the application of Gini’s classical measurements to studying significant phenomena today (transition to adulthood and leaving the parental home, health care, disabled persons and social integration). The subjects and measurements that appear here are not intended to exhaust the broad spectrum of Gini’s research work in the demographic and social field (nor could they), but they can make up a part of the intersection between his vast legacy and some interesting topics in current research, some of which were not even imaginable in the mid twentieth century. Looking at the many contributions that celebrated Gini in Treviso and thinking about his legacy, it seems possible to identify at least two typologies of approach, to be found in this issue of the journal, too. On the one hand, there are contributions that aim to retrieve and discuss themes, methodologies and measurements dealt with or used by Gini so as to evaluate their present relevance and importance in the current scholarly debate. On the other, there are contributions that deal with topics that are far from Gini’s work, as they study very recent phenomena, but actually, among other things, make use of methods and indicators devised by Gini that are now so much part of the common currency of methodology, so they don’t require explicit reference to their Author
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