Characterization of seasonal variations in responsiveness of pituitary gland to different doses of gonadotropin releasing hormone in buffalo cows

In tropical countries such as India, it has been observed that a number of buffalo cows experience seasonal anestrous during summer months. This might be due to seasonal changes in responsiveness of pituitary gland to gonadotropin releasing hormone (GnRH) and/or decreased hypothalamic GnRH release. Attempts were made to characterize the responsiveness of pituitary gland to a range of doses (0.1, 1, 10 and 33 µg) of GnRH in terms of LH and progesterone (P4) secretions during summer (April-May) and rainy (September-November) months. As a part of these studies, a radioimmunoassay method for estimation of circulating LH in buffalo cows was standardized. During summer months, it was observed that in the presence of low circulating P4 levels the minimum dose of GnRH required for eliciting a significant increase in circulating LH levels was 10 µg/animal that corresponded to a dose of ~28 ng/kg BW. However, during rainy months, administration of the same dose of GnRH failed to elicit a response suggesting that the pituitary gland is not responsive to low doses of exogenous GnRH.  On the other hand, buffalo cows receiving a dose of 100 µg of GnRH during rainy months elicited a surge-like increase in circulating LH that peaked at 2 h and the increase in LH concentrations lasted for nearly 6 h post GnRH treatment. The results appear to suggest that during summer months the pituitary gland function is not affected, but there may be lowered hypothalamic GnRH input to the pituitary gland

Twenty-three unsolved problems in hydrology (UPH) – a community perspective

This paper is the outcome of a community initiative to identify major unsolved scientific problems in hydrology motivated by a need for stronger harmonisation of research efforts. The procedure involved a public consultation through on-line media, followed by two workshops through which a large number of potential science questions were collated, prioritised, and synthesised. In spite of the diversity of the participants (230 scientists in total), the process revealed much about community priorities and the state of our science: a preference for continuity in research questions rather than radical departures or redirections from past and current work. Questions remain focussed on process-based understanding of hydrological variability and causality at all space and time scales. Increased attention to environmental change drives a new emphasis on understanding how change propagates across interfaces within the hydrological system and across disciplinary boundaries. In particular, the expansion of the human footprint raises a new set of questions related to human interactions with nature and water cycle feedbacks in the context of complex water management problems. We hope that this reflection and synthesis of the 23 unsolved problems in hydrology will help guide research efforts for some years to come

Measurement of the azimuthal anisotropy of Y(1S) and Y(2S) mesons in PbPb collisions at √S^{S}NN = 5.02 TeV

The second-order Fourier coefficients (υ$_{2}$) characterizing the azimuthal distributions of Υ(1S) and Υ(2S) mesons produced in PbPb collisions at $\sqrt{s_{NN}}$ = 5.02 TeV are studied. The Υmesons are reconstructed in their dimuon decay channel, as measured by the CMS detector. The collected data set corresponds to an integrated luminosity of 1.7 nb$^{-1}$. The scalar product method is used to extract the υ$_{2}$ coefficients of the azimuthal distributions. Results are reported for the rapidity range |y| < 2.4, in the transverse momentum interval 0 < p$_{T}$ < 50 GeV/c, and in three centrality ranges of 10–30%, 30–50% and 50–90%. In contrast to the J/ψ mesons, the measured υ$_{2}$ values for the Υ mesons are found to be consistent with zero

Measurement of the Y(1S) pair production cross section and search for resonances decaying to Y(1S)μ⁺μ⁻ in proton-proton collisions at √s = 13 TeV

The fiducial cross section for Y(1S)pair production in proton-proton collisions at a center-of-mass energy of 13TeVin the region where both Y(1S)mesons have an absolute rapidity below 2.0 is measured to be 79 ± 11 (stat) ±6 (syst) ±3 (B)pbassuming the mesons are produced unpolarized. The last uncertainty corresponds to the uncertainty in the Y(1S)meson dimuon branching fraction. The measurement is performed in the final state with four muons using proton-proton collision data collected in 2016 by the CMS experiment at the LHC, corresponding to an integrated luminosity of 35.9fb$^{-1}$. This process serves as a standard model reference in a search for narrow resonances decaying to Y(1S)μ$^{+}$μ$^{-}$ in the same final state. Such a resonance could indicate the existence of a tetraquark that is a bound state of two bquarks and two b̅ antiquarks. The tetraquark search is performed for masses in the vicinity of four times the bottom quark mass, between 17.5 and 19.5GeV, while a generic search for other resonances is performed for masses between 16.5 and 27GeV. No significant excess of events compatible with a narrow resonance is observed in the data. Limits on the production cross section times branching fraction to four muons via an intermediate Y(1S)resonance are set as a function of the resonance mass