Nuclear Effects on the UHE Neutrino-Nucleon Deep Inelastic Scattering Cross Section

Using a recent parametrization of nuclear effects in parton distribution functions we calculate the neutrino-nucleon cross section at energies relevant for ultra high energy neutrino telescopes. The modification of the cross section in comparison with the calculation using parton densities in free nucleons is of the order of few per cent for the parameter range of interest in neutrino telescopes (A=10 and E=10$^6$ GeV) and it reaches 20 % at the highest energies (E=10$^{12}$ GeV) and for the largest nuclear size (A=190) considered.Comment: 7 pages, Latex, figures as 3 postscript file

Measuring the BFKL Pomeron in Neutrino Telescopes

We present a new method for obtaining information on the small x behavior of the structure function F2 outside the kinematic range of present acelerators from the mean inelasticity parameter in UHE neutrino-nucleon DIS interactions which could be measured in neutrino telescopes.Comment: 12 pages, Latex, figures as 7 postscript file

Dataset of endometrial blood flow from pregnant and non-pregnant mares on day 7 and 8 post-ovulation

This article provides the dataset for the use of power Doppler ultrasound to assess the equine uterus from the recent research article titled “Power Doppler can detect the presence of 7-8 days conceptuses prior to flushing in an equine embryo transfer program”(1). The vascularization of the endometrium was objectively assessed in mares by quantification of pixels in bitmap format (BMP) using computer assisted analysis of images. Fifty-two mares were examined on days 7 (26 mares) and 8 (26 mares) post-ovulation prior to performing flushing procedures for embryo recovery. Receiver operating characteristic (ROC) curves and Youden's J statistics were used to evaluate the value of the suggested variable in terms of its diagnostic value for identification of early pregnancy and to establish cut-off values allowing differentiation between pregnant and non-pregnant mares on days 7 and 8 post-ovulation

Power Doppler can detect the presence of 7–8 day conceptuses prior to flushing in an equine embryo transfer program

In order to determine whether differences in uterine blood flow between pregnant and non-pregnant mares can be used to predict the presence of the equine embryo prior to flushing in an embryo transfer program, power Doppler ultrasonography was used on a total of 52 mares on days 7 or 8 post-ovulation. Computer analysis of Doppler images was subsequently performed using ImageJ v1.48 software. Vascular perfusion of the endometrium was analyzed using spot meter techniques, measuring mean pixel intensity and area of blood flow. Mares with positive flushings presented a higher uterine blood flow area (one embryo: 54.01 ± 2.27 mm2 or two embryos: 61.01 ± 6.73 mm2) prior to embryo recovery compared to barren mares (21.77 ± 2.22 mm2) (p ≤ 0.05). However, significant differences in vascular perfusion were not detected between single or twin pregnancies. Blood flow area appears to be a good predictor for differentiation between pregnant and non-pregnant mares with an AUC: 0.869; p ≤ 0.001 and an optimal cut-off value of 37.21 mm2. Both the mare's age and day of embryo recovery caused effects on uterine vascular perfusion. According to Youden's J statistics the uterine blood flow area of young pregnant mares was greater than 25.4 mm2 on day 7 (with a sensitivity of 75% and a specificity of 87.5%) and greater than 21.02 mm2 on day 8 post-ovulation (with a sensitivity of 93.8% and a specificity of 100%). The uterine blood flow area in adult pregnant mares was greater than 41.4 mm2 on day 7 (with a sensitivity of 80% and a specificity of 85.5%) and greater than 35.55 mm2 on day 8 after ovulation (with a sensitivity of 97.2% and a specificity of 85.7%). Evaluation on day 8 is therefore considered to be more reliable. Older and middle aged pregnant mares (5–18 years old) had increased uterine vascularization compared to young pregnant mares (2–5 years old) (p ≤ 0.001). Conversely, older barren mares showed higher endometrial vascularity (35.06 ± 2.56 mm2) than young (17.21 ± 1.26 mm2) and middle aged non-pregnant mares (23.84 ± 1.50 mm2) (p ≤ 0.05). We hypothesized that the higher blood flow area seen in older barren mares may be a consequence of a subclinical endometritis due to repeated flushing for embryo recovery. The results of the present study indicate that power Doppler ultrasound combined with computer assisted analysis of images are reliable techniques to detect early pregnancy prior to embryo recovery

An integrated overview on the regulation of sperm metabolism (glycolysis-Krebs cycle-oxidative phosphorylation)

An overview of the sperm metabolism is presented; using the stallion as a model we review glycolysis, Krebs Cycle and oxidative phosphorylation, paying special attention to the interactions among them. In addition, metabolism implies a series of coordinated oxidation-reduction reactions and in the course of these reactions reactive oxygen species (ROS) and reactive oxoaldehydes are produced ; the electron transport chain (ETC) in the mitochondria is the main source of the anion superoxide and hydrogen peroxide, while glycolysis produces 2-oxoaldehydes such as methylglyoxal as byproducts; due to the adjacent carbonyl groups are strong electrophiles (steal electrons oxidizing other compounds). Sophisticated mechanisms exist to maintain redox homeostasis, because ROS under controlled production also have important regulatory functions in the spermatozoa. The interactions between metabolism and production of reactive oxygen species are essential for proper sperm function, and deregulation of these processes rapidly leads to sperm malfunction and finally death. Lastly, we briefly describe two techniques that will expand our knowledge on sperm metabolism in the coming decades, metabolic flow cytometry and the use of the “omics” technologies, proteomics and metabolomics, specifically the micro and nano proteomics/metabolomics. A better understanding of the metabolism of the spermatozoa will lead to big improvements in sperm technologies and the diagnosis and treatment of male factor infertility

MicroRNA-24 regulates vascularity after myocardial infarction

BACKGROUND: Myocardial infarction leads to cardiac remodeling and development of heart failure. Insufficient myocardial capillary density after myocardial infarction has been identified as a critical event in this process, although the underlying mechanisms of cardiac angiogenesis are mechanistically not well understood. METHODS AND RESULTS: Here, we show that the small noncoding RNA microRNA-24 (miR-24) is enriched in cardiac endothelial cells and considerably upregulated after cardiac ischemia. MiR-24 induces endothelial cell apoptosis, abolishes endothelial capillary network formation on Matrigel, and inhibits cell sprouting from endothelial spheroids. These effects are mediated through targeting of the endothelium-enriched transcription factor GATA2 and the p21-activated kinase PAK4, which were identified by bioinformatic predictions and validated by luciferase gene reporter assays. Respective downstream signaling cascades involving phosphorylated BAD (Bcl-XL/Bcl-2-associated death promoter) and Sirtuin1 were identified by transcriptome, protein arrays, and chromatin immunoprecipitation analyses. Overexpression of miR-24 or silencing of its targets significantly impaired angiogenesis in zebrafish embryos. Blocking of endothelial miR-24 limited myocardial infarct size of mice via prevention of endothelial apoptosis and enhancement of vascularity, which led to preserved cardiac function and survival. CONCLUSIONS: Our findings indicate that miR-24 acts as a critical regulator of endothelial cell apoptosis and angiogenesis and is suitable for therapeutic intervention in the setting of ischemic heart disease. [KEYWORDS: Animals, Apoptosis/drug effects, Arterioles/pathology, Capillaries/pathology, Cell Hypoxia, Cells, Cultured/drug effects/metabolism, Collagen, Drug Combinations, Drug Evaluation, Preclinical, Endothelial Cells/ metabolism/pathology, GATA2 Transcription Factor/biosynthesis/genetics, Gene Expression Profiling, Heart Failure/etiology, Heme Oxygenase-1/biosynthesis/genetics, Laminin, Male, Mice, Mice, Inbred C57BL, MicroRNAs/antagonists & inhibitors/genetics/ physiology, Myocardial Infarc

The Stallion Spermatozoa: A Valuable Model to Help Understand the Interplay between Metabolism and Redox (De)regulation in Sperm Cells

Significance: Proper functionality of the spermatozoa depends on the tight regulation of their redox status; at the same time these cells are highly energy demanding and in the energetic metabolism, principally in the electron transport chain in the mitochondria, reactive oxygen species are continuously produced, in addition to that observed in the Krebs cycle and during the β-oxidation of fatty acids. Recent Advances: In addition, in glycolysis, elimination of phosphate groups from glyceraldehyde 3-phosphate and dihydroxyacetone phosphate results in the byproducts glyoxal (G) and methylglyoxal (MG); these products are 2-oxoaldehydes. The presence of adjacent carbonyl groups makes them strong electrophiles that react with nucleophiles in proteins, lipids, and DNA, forming advanced glycation end products. Critical Issues: This mechanism is behind subfertility in diabetic patients; in the animal breeding industry, commercial extenders for stallion semen contain a supraphysiological concentration of glucose that promotes MG production, constituting a potential model of interest. Future Directions: Increasing our knowledge of sperm metabolism and its interactions with redox regulation may improve current sperm technologies in use, and shall provide new clues to understanding infertility in males. Moreover, stallion spermatozoa due to its accessibility, intense metabolism, and suitability for proteomics/metabolomic studies may constitute a suitable model for studying regulation of metabolism and interactions between metabolism and redox homeostasis. Antioxid. Redox Signal. 37, 521-537

A Novel Typing Method for Streptococcus pneumoniae Using Selected Surface Proteins

The diverse pneumococcal diseases are associated with different pneumococcal lineages, or clonal complexes. Nevertheless, intra-clonal genomic variability, which influences pathogenicity, has been reported for surface virulence factors. These factors constitute the communication interface between the pathogen and its host and their corresponding genes are subjected to strong selective pressures affecting functionality and immunogenicity. First, the presence and allelic dispersion of 97 outer protein families were screened in 19 complete pneumococcal genomes. Seventeen families were deemed variable and were then examined in 216 draft genomes. This procedure allowed the generation of binary vectors with 17 positions and the classification of strains into surfotypes. They represent the outer protein subsets with the highest inter-strain discriminative power. A total of 116 non-redundant surfotypes were identified. Those sharing a critical number of common protein features were hierarchically clustered into 18 surfogroups. Most clonal complexes with comparable epidemiological characteristics belonged to the same or similar surfogroups. However, the very large CC156 clonal complex was dispersed over several surfogroups. In order to establish a relationship between surfogroup and pathogenicity, the surfotypes of 95 clinical isolates with different serogroup/serotype combinations were analyzed. We found a significant correlation between surfogroup and type of pathogenic behavior (primary invasive, opportunistic invasive, and non-invasive). We conclude that the virulent behavior of S. pneurnoniae is related to the activity of collections of, rather than individual, surface virulence factors. Since surfotypes evolve faster than MLSTs and directly reflect virulence potential, this novel typing protocol is appropriate for the identification of emerging clones

Differences in the proteome of stallion spermatozoa explain stallion-to-stallion variability in sperm quality post-thaw†

The identification of stallions and or ejaculates that will provide commercially acceptable quality post-thaw before cryopreservation is of great interest, avoiding wasting time and resources freezing ejaculates that will not achieve sufficient quality to be marketed. Our hypothesis was that after bioinformatic analysis, the study of the stallion sperm proteome can provide discriminant variables able to predict the post-thaw quality of the ejaculate. At least three ejaculates from 10 different stallions were frozen following a split sample design. Half of the ejaculate was analyzed as a fresh aliquot and the other half was frozen and then analyzed as a frozen-thawed aliquot. Computer-assisted sperm analysis and flow cytometry were used to analyze sperm quality. Detailed proteomic analysis was performed on fresh and frozen and thawed aliquots, and bioinformatic analysis was used to identify discriminant variables in fresh samples able to predict the outcome of cryopreservation. Those with a fold change > 3, a P = 8.2e-04, and a q = 0.074 (equivalent to False discovery rate (FDR)) were selected, and the following proteins were identified in fresh samples as discriminant variables of good motility post-thaw: F6YTG8, K9K273, A0A3Q2I7V9, F7CE45, F6YU15, and F6SKR3. Other discriminant variables were also identified as predictors of good mitochondrial membrane potential and viability post-thaw. We concluded that proteomic approaches are a powerful tool to improve current sperm biotechnologies

Low glucose and high pyruvate reduce the production of 2-oxoaldehydes, improving mitochondrial efficiency, redox regulation, and stallion sperm function

Energy metabolism in spermatozoa is complex and involves the metabolism of carbohydrate fatty acids and amino acids. The ATP produced in the electron transport chain in the mitochondria appears to be crucial for both sperm motility and maintaining viability, whereas glycolytic enzymes in the flagella may contribute to ATP production to sustain motility and velocity. Stallion spermatozoa seemingly use diverse metabolic strategies, and in this regard, a study of the metabolic proteome showed that Gene Ontology terms and Reactome pathways related to pyruvate metabolism and the Krebs cycle were predominant. Following this, the hypothesis that low glucose concentrations can provide sufficient support for motility and velocity, and thus glucose concentration can be significantly reduced in the medium, was tested. Aliquots of stallion semen in four different media were stored for 48 h at 18°C; a commercial extender containing 67 mM glucose was used as a control. Stallion spermatozoa stored in media with low glucose (1 mM) and high pyruvate (10 mM) (LG-HP) sustained better motility and velocities than those stored in the commercial extender formulated with very high glucose (61.7 ± 1.2% in INRA 96 vs 76.2 ± 1.0% in LG-HP media after 48 h of incubation at 18°C; P < 0.0001). Moreover, mitochondrial activity was superior in LG-HP extenders (24.1 ± 1.8% in INRA 96 vs 51.1 ± 0.7% in LG-HP of spermatozoa with active mitochondria after 48 h of storage at 18°C; P < 0.0001). Low glucose concentrations may permit more efficient sperm metabolism and redox regulation when substrates for an efficient tricarboxylic acid cycle are provided. The improvement seen using low glucose extenders is due to reductions in the levels of glyoxal and methylglyoxal, 2-oxoaldehydes formed during glycolysis; these compounds are potent electrophiles able to react with proteins, lipids, and DNA, causing sperm damage