Quality of seminal fluids varies with type of stimulus at ejaculation.

The theory of ejaculate economics was mainly built around different sperm competition scenarios but also predicts that investments into ejaculates depend on female fecundity. Previous tests of this prediction focused on invertebrates and lower vertebrate, and on species with high female reproductive potential. It remains unclear whether the prediction also holds for polygynous mammals with low female reproductive potential (due to low litter size and long inter-birth intervals). We used horses (Equus caballus) to experimentally test whether semen characteristics are adjusted to the oestrous cycle of the mare a stallion is exposed to during few moments before ejaculation. We analysed 122 weekly semen samples collected from 16 stallions during exposure to either an oestrous or a dioestrous mare. Semen volume and the rate of motile sperm were higher when stallions were exposed to an oestrous than to a diestrous mare, while total sperm counts and sperm velocity remained unchanged. Sperm collected after exposure to an oestrous mare also showed reduced oxidative degeneration of cell membranes over a period of 48 hours. We conclude that stallions invest more into their seminal fluids when the chance of fertilization is elevated, and that this adjustment of ejaculate quality can happen very quickly

Embryo survival in the oviduct not significantly influenced by major histocompatibility complex social signaling in the horse.

The major histocompatibility complex (MHC) influences sexual selection in various vertebrates. Recently, MHC-linked social signaling was also shown to influence female fertility in horses (Equus caballus) diagnosed 17 days after fertilization. However, it remained unclear at which stage the pregnancy was terminated. Here we test if MHC-linked cryptic female choice in horses happens during the first days of pregnancy, i.e., until shortly after embryonic entrance into the uterus and before fixation in the endometrium. We exposed estrous mares to one of several unrelated stallions, instrumentally inseminated them with semen of another stallion, and flushed the uterus 8 days later to test for the presence of embryos. In total 68 embryos could be collected from 97 experimental trials. This success rate of 70.1% was significantly different from the mean pregnancy rate of 45.7% observed 17 days after fertilization using the same experimental protocol but without embryo flushing. Embryo recovery rate was not significantly dependent on whether the mares had been socially exposed to an MHC-dissimilar or an MHC-similar stallion. These observations suggest that MHC-linked maternal strategies affect embryo survival mainly (or only) during the time of fixation in the uterus

Calibration of parallel kinematics machine-tools using small displacement torsors

The accuracy of a machine-tool depends on manufacturing and assembly errors, backlash in the structure and the links, thermal variations, vibrations, and others. The method presented in this paper deals with manufacturing and assembly errors but it can be adapted to other sources of errors. This method uses the concept of Small Displacement Torsors (SDT) to the calibration of parallel kinematics machine-tools. The following hypothesis is made: the defaults of the structure can be modelled by a combination of small displacements of the surfaces in contact. The method consists first of all in modelling each link by a SDT expressed in the local frame of the link (n parameters characterize the defaults of the structure). Then each torsor is written in the frame of the structure where measurements are done. The value of the components of the torsors depends on the pose (position and orientation) of the tool. The relations between the torsors and the tool pose are calculated (N equations connect the parameters to the pose of the tool). Then the pose error is measured in m correctly selected points, so that the n parameters can be identified solving the equation : E=M.D, where E is the vector containing the measured pose errors ; M is the invertible matrix formed with the relations between the torsors and the tool pose ; D is the vector containing the parameters of the torsors. After the identification of vector D, the hypothesis of small displacement must be verified. Finally the pose error of the tool can be calculated in all the working volume. This paper presents the general method based on the Small Displacement Torsors. The links used in machine-tools is modelled by SDT. Then this method is applied to the calibration of the Hita-STT machine-tool, an industrial prototype. The objective is to reach an absolute accuracy of less than 10 microns with a relative accuracy of 5 microns, considering manufacturing and assembly errors in the first calibration phase

IUPAC specification for the FAIR management of spectroscopic data in chemistry (IUPAC FAIRSpec) - guiding principles

set of guiding principles for the development of a standard for FAIR management of spectroscopic data are outlined and discussed. The principles form the basis for future recommendations of IUPAC Project 2019-031-1-024 specifying a detailed data model and metadata schema for describing the contents of an “IUPAC FAIRData Collection” and the organization of digital objects within that collection. Foremost among the recommendations will be a specification for an “IUPAC FAIRData Finding Aid” that describes the collection in such a way as to optimize the findability, accessibility, interoperability, and reusability of its contents. Results of an analysis of data provided by an American Chemical Society Publications pilot study are discussed in relation to potential workflows that might be used in implementing the “IUPAC FAIRSpec” standard based on these principles

NMReDATA, a standard to report the NMR assignment and parameters of organic compounds

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link. Open access articleEven though NMR has found countless applications in the field of small molecule characterization, there is no standard file for the NMR data relevant to structure characterization of small molecules. A file format is introduced to associate the NMR parameters extracted from 1D and 2D spectra of organic compounds to the assigned chemical structure. These NMR parameters, which we shall call NMReDATA, include chemical shift values, signal integrals, intensities, multiplicities, scalar coupling constants, lists of 2D correlations, relaxation times and diffusion rates. The file format is an extension of the existing SDF (Structure Data Format), which is compatible with the commonly used MOL format. The association of an NMReDATA file with the raw and spectral data from which it originates constitutes an NMR record. This format is easily readable by humans and computers and provides a simple and efficient way for disseminating results of structural chemistry investigations, automating the verification of published result, and for assisting the constitution of highly needed open-source structural databases