Ovum Pick-up in cattle – a 25-yr retrospective analysis

Repeated oocyte collection by transvaginal ultrasound-guided follicular puncture (Ovum Pick-Up, OPU), implicitly associated to in vitro embryo production (IVEP), has become alternative and competitive to superovulation for embryo production in cattle. It is alternative because it can be applied successfully irrespective of the reproductive status of the donor, i.e. in pregnant and acyclic animals, in those having patent tube or genital tract infections and in animals insensitive to superovulatory treatment. It is competitive because it can yield more transferable embryos per donor on a monthly basis. Through the years, the number of transferable embryos provided by OPU has significantly increased mainly due to the technological improvement of IVEP. However, limits to OPU application remain due to lower pregnancy rate of in vitro vs in vivo produced embryos or non optimal co-operation between OPU practitioners and IVF laboratories. This review will focus on the technical modifications proposed for improving OPU efficiency, the analysis of the physiological parameters that affect OPU and IVEP efficiency and, finally, the use of OPU as a tool to study and manipulate reproductive activity in cattle

NLSE on the half-line with point interactions

We investigate the existence and the uniqueness of NLS ground states of fixed mass on the half-line in the presence of a point interaction at the origin. The nonlinearity is of power type, and the regime is either $L^2$-subcritical or $L^{2}$-critical, while the point interaction is either attractive or repulsive. In the $L^{2}$-subcritical case, we prove that ground states exist for every mass value if the interaction is attractive, while ground states exist only for sufficiently large masses if the interaction is repulsive. In the latter case, if the power is less or equal to four, ground states coincide with the only bound state. If instead, the power is greater than four, then there are values of the mass for which two bound states exist, and neither of the two is a ground state, and values of the mass for which two bound states exist, and one of them is a ground state. In the $L^{2}$-critical case, we prove that ground states exist for masses strictly below a critical mass value in the attractive case, while ground states never exist in the repulsive case.Comment: 17 page

gamete quality in a multistressor environment

Over the past few decades, accumulated evidence confirms that the global environment conditions are changing rapidly. Urban industrialization, agriculture and globalization have generated water, air and soil pollution, giving rise to an environment with a growing number of stress factors, which has a serious impact on the fitness, reproduction and survival of living organisms. The issue raises considerable concern on biodiversity conservation, which is now at risk: it is estimated that a number of species will be extinct in the near future. Sexual reproduction is the process that allows the formation of a new individual and is underpinned by gamete quality defined as the ability of spermatozoa and oocytes to interact during fertilization leading to the creation and development of a normal embryo.This review aimed to provide the current state of knowledge regarding the impact of a broad spectrum of environmental stressors on diverse parameters used to estimate and evaluate gamete quality in humans and in canonical animal models used for experimental research.Effects of metals, biocides, herbicides, nanoparticles, plastics, temperature rise, ocean acidification, air pollution and lifestyle on the physiological parameters that underlie gamete fertilization competence are described supporting the concept that environmental stressors represent a serious hazard to gamete quality with reproductive disorders and living organism failure. Although clear evidence is still limited, gamete capacity to maintain and/or recover physiological conditions is recently demonstrated providing further clues about the plasticity of organisms and their tolerance to the pressures of pollution that may facilitate the reproduction and the persistence of species within the scenario of global change.Changes in the global environment must be urgently placed at the forefront of public attention, with a massive effort invested in further studies aimed towards implementing current knowledge and identifying new methodologies and markers to predict impairment of gamete quality. Keywords: Gamete quality, Environmental stress, Fertilization, Xenobiotic, Climate change, Life styl

Developmental Potential in Bovine Oocytes Is Related to Cumulus-Oocyte Complex Grade, Calcium Current Activity, and Calcium Stores

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Heat stress affects reproductive performance of high producing dairy cows bred in an area of southern Apennines

A 5-year retrospective (from 2008 to 2012) survey was carried out by analyzing data of high producing dairy cows reared in farms located in an area of southern Apennines. The indicators of fertility obtained were related to either season variations or the temperature-humidity index (THI). A significant lower number of conceptions evaluated per month on an annual basis (NCY), i.e., a parameter obtained by subtracting gestation length to the calving date, was found during the summer months; furthermore, this parameter decreased along with THI increase. The number of heats detected varied equally to NCY and represented the main cause of the lower fertility consequent to heat stress (HS). The age at first calving was not significantly affected by either the season or the THI. The mean number of AI/pregnancy in relation to the calving time was significantly affected by the season but it was not related to THI. The number of days open was significantly larger in the animals calved from January to July than from August to December (163±33 vs 123±36 days; P< 0.001); this causes an annual economic loss of several thousand euro in each farm analyzed. In conclusion, HS causes severe economic losses in dairy farms located in southern Apennines that are mainly due to a lower number of heats detected as well as a larger number of days open and semen doses used

Analytical Validation of Two Assays for Equine Ceruloplasmin Ferroxidase Activity Assessment

: Ceruloplasmin (Cp) assessment in biological samples exploits the oxidase activity of this enzyme against several substrates, such as p-phenylenediamine (p-P), o-dianisidine (o-D) and, most recently, ammonium iron(II) sulfate (AIS). Once developed in humans, these assays are often used in veterinary medicine without appropriately optimizing in the animal species of interest. In this study, two assays using AIS and o-D as substrates have been compared and validated for Cp oxidase activity assessment in horse's plasma. The optimization of the assays was performed mainly by varying the buffer pH as well as the buffer and the substrate molar concentration. Under the best analytical conditions obtained, the horse blood serum samples were treated with sodium azide, a potent Cp inhibitor. In the o-D assay, 500 µM sodium azide treatment completely inhibits the enzymatic activity of Cp, whereas, using the AIS assay, a residual analytical signal was still present even at the highest (2000 µM) sodium azide concentration. Even though the analytical values obtained from these methods are well correlated, the enzymatic activity values significantly differ when expressed in Units L-1. A disagreement between these assays has also been detected with the Bland-Altman plot, showing a progressive discrepancy between methods with increasing analytical values

NLS ground states on a hybrid plane

We study the existence, the nonexistence, and the shape of the ground states of a Nonlinear Schr\"odinger Equation on a manifold called hybrid plane, that consists of a half-line whose origin is connected to a plane. The nonlinearity is of power type, focusing and subcritical. The energy is the sum of the Nonlinear Schr\"odinger energies with a contact interaction on the half-line and on the plane with an additional quadratic term that couples the two components. By ground state we mean every minimizer of the energy at a fixed mass. As a first result, we single out the following rule: a ground state exists if and only if the confinement near the junction is energetically more convenient than escaping at infinity along the halfline, while escaping through the plane is shown to be never convenient. The problem of existence reduces then to a competition with the one-dimensional solitons. By this criterion, we prove existence of ground states for large and small values of the mass. Moreover, we show that at given mass a ground state exists if one of the following conditions is satisfied: the interaction at the origin of the half-line is not too repulsive; the interaction at the origin of the plane is sufficiently attractive; the coupling between the half-line and the plane is strong enough. On the other hand, nonexistence holds if the contact interactions on the half-line and on the plane are repulsive enough and the coupling is not too strong. Finally, we provide qualitative features of ground states. In particular, we show that in the presence of coupling every ground state is supported both on the half-line and on the plane and each component has the shape of a ground state at its mass for the related Nonlinear Schr\"odinger energy with a suitable contact interaction. These are the first results for the Nonlinear Schr\"odinger Equation on a manifold of mixed dimensionality.Comment: 31 pages, 1 figure. Keywords: hybrids, standing waves, nonlinear Schr\"odinger, ground states, delta interaction, radially symmetric solutions, rearrangement

The search for NLS ground states on a hybrid domain: Motivations, methods, and results

We discuss the problem of establishing the existence of the Ground States for the subcritical focusing Nonlinear Schrödinger energy on a domain made of a line and a plane intersecting at a point. The problem is physically motivated by the experimental realization of hybrid traps for Bose-Einstein Condensates, that are able to concentrate the system on structures close to the domain we consider. In fact, such a domain approximates the trap as the temperature approaches the absolute zero. The spirit of the paper is mainly pedagogical, so we focus on the formulation of the problem and on the explanation of the result, giving references for the technical points and for the proofs

NLS Ground States on a Hybrid Plane

We study the existence, the nonexistence, and the shape of the ground states of a Nonlinear Schrödinger Equation on a manifold called hybrid plane, that consists of a half-line whose origin is connected to a plane. The nonlinearity is of power type, focusing and subcritical. The energy is the sum of the Nonlinear Schrödinger energies with a contact interaction on the half-line and on the plane with an additional quadratic term that couples the two components. By ground state we mean every minimizer of the energy at a fixed mass. As a first result, we single out the following rule: a ground state exists if and only if the confinement near the junction is energetically more convenient than escaping at infinity along the halfline, while escaping through the plane is shown to be never convenient. The problem of existence reduces then to a competition with the one-dimensional solitons. By this criterion, we prove existence of ground states for large and small values of the mass. Moreover, we show that at given mass a ground state exists if one of the following conditions is satisfied: the interaction at the origin of the half-line is not too repulsive; the interaction at the origin of the plane is sufficiently attractive; the coupling between the half-line and the plane is strong enough. On the other hand, nonexistence holds if the contact interactions on the half-line and on the plane are repulsive enough and the coupling is not too strong. Finally, we provide qualitative features of ground states. In particular, we show that in the presence of coupling every ground state is supported both on the half-line and on the plane and each component has the shape of a ground state at its mass for the related Nonlinear Schrödinger energy with a suitable contact interaction. These are the first results for the Nonlinear Schrödinger Equation on a manifold of mixed dimensionality

Meiosis progression and donor age affect expression profile of DNA repair genes in bovine oocytes

Several genetic and physiological factors increase the risk of DNA damage in mammalian oocytes. Two critical events are meiosis progression, from maturation to fertilization, due to the extensive chromatin remodelling during genome decondensation and aging which is associated to a progressive oxidative stress. In this work, we studied the transcriptional patterns of three genes, RAD51, APEX-1 and MLH1, involved in DNA repair mechanisms. The analyses were performed by Real-Time quantitative PCR (RT-qPCR) in immature and in vitro matured oocytes collected from 17 ± 3 mo old heifers and 94 ± 20 mo old cows. Batches of 30-50 oocytes for each group (three replicates) were collected from ovarian follicles of slaughtered animals. The oocytes were freed from cumulus cells at the time of follicle removal, or after IVM carried out in M199 supplemented with 10% foetal calf serum, 10 IU LH /ml, 0.1 IU FSH /ml and 1 µg 17β-oestradiol/ml. Total RNA was extracted by Trizol method. The expression of bovine GAPDH gene was used as internal standard, while primers for bovine RAD51, APEX-1 and MLH1 genes were designed from DNA sequences retrieved from GeneBank. Results obtained indicate a clear up-regulation of RAD51, APEX-1 and MLH1 genes after IVM ranging between 2- and 4-fold compared to GV oocytes. However, only RAD51 showed a significant transcript increase between the immature oocytes collected from young and old individuals. This finding candidates RAD51 as gene marker for discriminating bovine immature oocytes in relation to the donor age