Head Tail Research Articles

Focus on centrin in normal and altered human spermatozoa

This review provides details on the role of centrin in human spermatozoa and in various forms of male infertility. Centrin is a calcium (Ca2+)-binding phosphoprotein that is located in the centrioles – which are typical structures of the sperm connecting piece and play a key role in centrosome dynamics during sperm morphogenesis – as well as in zygotes and early embryos during spindle assembly. In humans, three different centrin genes encoding three isoforms have been discovered. Centrin 1, the only one expressed in spermatozoa, seems to be lost inside the oocyte after fertilization. The sperm connecting piece is characterized by the presence of numerous proteins including centrin, that deserves particular attention because, in humans, it is enriched during maturation of the centrioles. In normal sperm, centrin 1 is visible as two distinct spots in the head–tail junction; however, in some defective spermatozoa, centrin 1 distribution is altered. Centrin has been studied in humans and animal models. Its mutations may lead to several structural alterations, such as serious defects in the connective piece and, subsequently, fertilization failure or incomplete embryonic development. However, the effects of these abnormalities on male fertility have not been fully studied. Because the presence and the function of centrin in the sperm connecting piece appears important for reproductive success, additional studies are needed to bring medical benefits in resolving some cases of idiopathic infertility.

Design, Fabrication, and Characterization of a Helical Adaptive Multi-Material MicroRobot (HAMMR)

Adaptive locomotion is an advanced function of microrobots that can be achieved using smart materials. In this letter, a responsive hydrogel is utilized as a smart material and used to fabricate Helical Adaptive Multi-material MicroRobots (HAMMRs) with deformable tails to achieve adaptive locomotion capabilities. Moreover, a novel fabrication method is proposed to realize these types of helical microrobots with enhanced swimming performances by taking advantage of a strong magnetic head and deformable tail. The deformations of different tail designs and the fabricated microrobots are tested in different solvents. The swimming performances of the swimming microrobots are investigated experimentally under a rotating magnetic field and verified with theoretical calculations. The HAMMRs show significant deformations upon stimulation and changes in swimming performance which are in agreement with the scaled calculation result. Finally, the HAMMRs present an enhanced mobility with a highest published translational velocity for an adaptive swimming microrobot of 8.1 body length per second.

A new catalog of head–tail radio galaxies from LoTSS DR1

The unique morphology of head-tail (HT) radio galaxies suggests that radio jets and their intra-cluster medium interact strongly. We conducted a systematic search for HT radio galaxies using the LOFAR Two-metre Sky Survey first data release (LoTSS DR1) at 144 MHz. In this paper, a catalogue of fifty-five new HT radio galaxies is presented, ten of which are narrow-angle tailed sources (NATs) and forty-five of which are wide-angle tailed sources (WATs). NATs are characterised by tails that are bent like a narrow `V' shape with a less than 90 degree opening angle. The opening angle between jets in WAT radio galaxies is greater than ninety degrees, exhibiting wide `C'-like morphologies. We found that thirty out of fifty-five HT radio galaxies reported in this article are associated with known galaxy clusters. Most of the sources presented in the current paper have redshifts $<$ 0.5. The various physical properties and statistical studies of these HT radio galaxies are presented.

Isolation and phenotypic characterization of bacteriophage SA14 with lytic- and anti-biofilm activity against multidrug-resistant Enterococcus faecalis

BackgroundAntimicrobial resistance is a growing global health concern demanding more attention and action at the international-, national- and regional levels. In the present study, bacteriophage was sought as a potential alternative to traditional antibiotics.ResultsVancomycin-resistant Enterococcus faecalis was isolated from a urine sample. Partial 16S rRNA-gene sequencing and VITEK®2 system were employed for its identification, biochemical characterization, and antibiotic susceptibility testing. The isolate was resistant to eight antibiotics (out of 11): vancomycin, gentamicin (high-level synergy), streptomycin (high-level synergy), ciprofloxacin, levofloxacin, erythromycin, quinupristin/dalfopristin, and tetracycline. Bacteriophage SA14 was isolated from sewage water using the multidrug-resistant isolate as a host. Transmission electron micrographs revealed that phage SA14 is a member of the Siphoviridae family displaying the typical circular head and long non-contractile tail. The phage showed characteristic stability to a wide range of solution pH and temperatures, with optimal stability at pH 7.4 and 4 °C, while showing high specificity toward their host. Based on the one-step growth curve, the phage's latent period was 25 min, and the burst size was 20 PFU/ml. The lytic activity of phage SA14 was evaluated at various multiplicities of infection (MOI), all considerably suppressed the growth of the host organism. Moreover, phage SA14 displayed a characteristic anti-biofilm activity as observed by the reduction in adhered biomass and -viable cells in the pre-formed biofilm by 19.1-fold and 2.5-fold, respectively.ConclusionPhage therapy can be a valuable alternative to antibiotics against multi-drug resistant microorganisms.

A Novel Surfactant with Short Hydrophobic Head and Long Hydrophilic Tail Generates Vesicles with Unique Structural Feature.

Surfactant molecules typically have a long hydrophobic tail and a short hydrophilic head group. It remains unexplored if surfactants can have a short hydrophobic head group and a long hydrophilic tail. Designing such surfactants is a challenge as a lengthy hydrophilic tail would completely solubilize the molecules. In this context, herein, the Fmoc-functionalized Gly-Pro-Hyp (GPO) tripeptide repeat-based molecule (Fm-GPO) with fluorenyl moiety as a short hydrophobic head and peptide as a long hydrophilic tail is demonstrated as a reverse surfactant at physiological pH, for the first time. π-π stacking of the fluorenyl moieties and intermolecular hydrogen bonding between the peptide chains with extended polyproline-II structure promoted the self-assembly into spherical vesicles with a unique feature of a large hydrophilic area in the interior and exterior of the bilayer. The current Fm-GPO system offers a new class of surfactants with unique features that can aid in the design of drug-loaded vehicles, which can be target-specific as the peptide chain can be manipulated with different functional ultra-short peptide sequences.

Sustained and Targeted Delivery of Self-Assembled Doxorubicin Nonapeptides Using pH-Responsive Hydrogels for Osteosarcoma Chemotherapy

While chemotherapeutic agents have particularly potent effects in many types of cancer, their clinical applications are still far from satisfactory due to off-target drug exposure, chemotherapy resistance, and adverse effects, especially in osteosarcoma. Therefore, it is clinically promising to construct a novel tumor-targeted drug delivery system to control drug release and alleviate side effects. In this study, a pH-responsive nonapeptide hydrogel was designed and fabricated for the tumor-targeted drug delivery of doxorubicin (DOX). Using a solid-phase synthesis method, a nonapeptide named P1 peptide that is structurally akin to surfactant-like peptides (SLPs) due to its hydrophobic tail and hydrophilic head was synthesized. The physicochemical properties of the P1 hydrogel were characterized via encapsulation capacity, transmission electron microscopy (TEM), circular dichroism (CD), zeta potential, rheological analysis, and drug release studies. We also used in vitro and in vivo experiments to investigate the cytocompatibility and tumor inhibitory efficacy of the drug-loaded peptide hydrogel. The P1 peptide could self-assemble into biodegradable hydrogels under neutral conditions, and the prepared drug-loaded hydrogels exhibited good injectability and biocompatibility. The in vitro drug release studies showed that DOX-P1 hydrogels had high sensitivity to acidic conditions (pH 5.8 versus 7.4, up to 3.6-fold). Furthermore, the in vivo experiments demonstrated that the DOX-P1 hydrogel could not only amplify the therapeutic effect but also increase DOX accumulation at the tumor site. Our study proposes a promising approach to designing a pH-responsive hydrogel with controlled doxorubicin-release action based on self-assembled nonapeptides for targeted chemotherapy.

Hexamethylenetetramine additive with zincophilic head and hydrophobic tail for realizing ultra-stable Zn anode

Aqueous zinc batteries are regarded as one of the promising next-generation energy storage batteries due to their high safety and low cost, however, one of the most important problems limiting their commercialization is the cyclic stability of the zinc anode. Therefore, in this work, we first employed hexamethylenetetramine (HMT) as the electrolyte additive to in-situ construct a Zn-HMT complex film to stabilize the zinc anode. After adding the HMT, its zincophilic head will be prior to adsorbing on the zinc foil to form Zn-HMT complex film and then introduce uniform zinc deposition, and simultaneously the formed Zn-HMT complex with hydrophobic alkyl tail will repel the H2O from combining with Zn2+ to form Zn4SO4(OH)6·nH2O by-product as well as the hydrogen evolution reaction (HER). As a result, the HMT-based electrolyte promotes ultra-stable zinc anode cycling for as long as 2000 h with extremely high average Coulombic efficiency (99.51 %). When applied in the Zn-V2O5 full cell, it also demonstrates outstanding electrochemical performances with a reversible capacity as high as 197.8 mAh/g after 500 cycles. This work provides a simple and effective method for the implementation of high-safety and high-stable aqueous zinc-ion batteries.

Hydroacoustic survey on fish spatial distribution in the early impoundment stage of Yuwanghe Reservoir in southwest China

Understanding the fish community structure and spatial distribution characteristics is essential for appropriate reservoir fishery management, especially in the early impoundment stage of the reservoir, which could help in obtaining basic data and performing artificial adjustments to biological communities. On the basis of this concept, we conducted a survey of the fish community and distribution at the newly constructed reservoir in southwest China by using a combination of methods, including hydroacoustic survey and fish sampling. Fish sampling showed a single fish community structure (six species belonging to four families) assembled in the reservoir, and the dominant species was Pseudorasbora parva which accounted for 98.79% of the fish population. In the hydroacoustic survey, the average fish density was 318.7 ± 256.1 individuals/1,000 m2. Irregular distribution of the fish was observed in the horizontal direction. The fish densities in the head area, middle area, and tail area of the reservoir were 168.5 ± 60.1, 306.8 ± 124.7, and 696.4 ± 288.9 individuals/1,000 m2, respectively, which showed a trend of increase in fish density with an increase in distance from the dam. More than 97.3% of the fish in the vertical direction were distributed in the water layer of depth 0 to 12 m. The average total length of fish was 75.4 mm, and the mean fish biomass in the reservoir was approximately 984.8 g/1,000 m2. According to Pearson correlation analysis, the main factors affecting the spatial distribution of fish were water depth, water temperature, dissolved oxygen, total nitrogen, and plankton density. Our results suggested that the fish community structure should be adjusted by releasing native carnivorous fish to control the abundance of small fish. Moreover, filter-feeding fish such as silver carp and bighead carp should be released in the reservoir to control the plankton community; this will enable the maintenance of the reservoir ecosystem in a healthy state while increasing the economic benefits to the local area.

Elucidation of the cytogenotoxic potential of vigabatrin and its in silico computer-assisted DNA interaction

Vigabatrin (VGB) is a gammaaminobutyric acid-ergic (GABA-ergic) antiepileptic drug (AED) and is one of 2 approved drugs available to treat infantile spasms (IS). The aim of this study is to elucidate conflicting data on the toxic effects of VGB and to obtain detailed information about its possible cytogenotoxic effects in human lymphocytes. For this purpose, in vitro Chromosomal Aberration (CA), Sister Chromatid Exchange (SCE), Micronucleus (MN) tests, and Comet Assay were performed to determine possible genotoxic and cytotoxic effects of VGB. In addition, the binding energy level of VGB to DNA was determined in silico by molecular docking. The highest concentration (80 μg/ml) of VGB increased the SCE, CA, MN and micronucleated binuclear cell (BNMN) frequency significantly compared to the control after 24 and 48 hours of treatment. In the tail density and tail length parameters, the dose-dependent increase was found to be statistically significant compared to the control. At the 40 and 80 μg/ml concentrations of VGB for 48 hours caused a statistically significant increase in both CA/Cell and AC percentages, while MI and NDI decreased only significantly at the highest concentration (80 µg/ml) causing. In the Comet Assay head density, tail density and tail length parameters, the dose-dependent increase was found to be statistically significant compared to the control. Also, the in silico molecular docking analysis showed that VGB interacts with B-DNA close to the threshold binding energy. The lowest negative free binding energy (ΔG binding) was found as −5.13 kcal/mol. In conclusion, all results are evaluated together, it has been determined that VGB has cytogenotoxic effects in vitro and binds to DNA in silico with significant free binding energy.

Isolation and characterization of a lytic Salmonella Typhimurium-specific phage as a potential biofilm control agent

This study aimed to characterize a lytic Salmonella Typhimurium-specific (ST) phage and its biofilm control capability against S. Typhimurium biofilm on polypropylene surface. ST phage was isolated, propagated, and purified from water used in a slaughterhouse. The morphology of ST phage was observed via transmission electron microscopy. Its bactericidal effect was evaluated by determining bacterial concentrations after the phage treatment at various multiplicities of infection (MOIs) of 0.01, 1.0, and 100. Once the biofilm was formed on the polypropylene tube after incubation at 37°C for 48 h, the phage was treated and its antibiofilm capability was determined using crystal violet staining and plate count method. The phage was isolated and purified at a final concentration of ∼11 log PFU/mL. It was identified as a myophage with an icosahedral head (∼104 nm) and contractile tail (∼90-115 nm). ST phage could significantly decrease S. Typhimurium population by ∼2.8 log CFU/mL at an MOI of 100. After incubation for 48 h, biofilm formation on polypropylene surface was confirmed with a bacterial population of ∼6.9 log CFU/cm2. After 1 h treatment with ST phage, the bacterial population in the biofilm was reduced by 2.8 log CFU/cm2. Therefore, these results suggest that lytic ST phage as a promising biofilm control agent for eradicating S. Typhimurium biofilm formed on food contact surfaces.

Research on Tracking and Identification of Typical Protective Behavior of Cows Based on DeepLabCut

In recent years, traditional farming methods have been increasingly replaced by more modern, intelligent farming techniques. This shift towards information and intelligence in farming is becoming a trend. When they are bitten by dinoflagellates, cows display stress behaviors, including tail wagging, head tossing, leg kicking, ear flapping, and skin fluttering. The study of cow protective behavior can indirectly reveal the health status of cows and their living patterns under different environmental conditions, allowing for the evaluation of the breeding environment and animal welfare status. In this study, we generated key point feature marker information using the DeepLabCut target detection algorithm and constructed the spatial relationship of cow feature marker points to detect the cow’s protective behavior based on the change in key elements of the cow’s head swinging and walking performance. The algorithm can detect the protective behavior of cows, with the detection accuracy reaching the level of manual detection. The next step in the research focuses on analyzing the differences in protective behaviors of cows in different environments, which can help in cow breed selection. It is an important guide for diagnosing the health status of cows and improving milk production in a practical setting.

A Clinical Trial on the Welfare Effects of Administering Meloxicam to 10-21 Day Dairy Calves Following Caustic Paste Disbudding.

Caustic paste disbudding (CPD) is widely utilized for calves, which has been known to result in adverse effects on the calves and ethical concerns related to animal welfare, despite the use of local anesthetics. The administration of meloxicam has been demonstrated to provide benefits in alleviating pain and inflammation in juvenile calves under nine days old and subjected to CPD. Nonetheless, there is a scarcity of literature documenting the beneficial impact of meloxicam in alleviating pain in calves aged over nine days that have undergone CPD. Therefore, the objective of this clinical trial was to evaluate the efficacy of administering meloxicam and lidocaine for cornual nerve block together in mitigating the deleterious effects of CPD, as opposed to using lidocaine alone in calves older than nine days. Thirty Holstein calves, aged between 10 and 21 days, were enrolled and randomly assigned to 1 of 2 treatments: lidocaine alone (Placebo), lidocaine and normal saline treatment before CPD, and lidocaine plus meloxicam (MX), lidocaine and 0.5mg/kg of meloxicam treatment prior to CPD. The researchers were blind to the treatment of calves to control the subjective error. The occurrences of actions associated with pain, which included head shaking, head rubbing, ear flicking, tail flicking, kicking, and head passing through the fence, were recorded. Physiological performance, including the respiration rate, heart rate, rectal temperature, mechanical nociceptive threshold (MNT), food intake, and daily activity level, was monitored. Hematological conditions were ascertained through the use of routine blood tests and enzyme-linked immunosorbent assay. The generalized linear mixed model (GLMM) was employed to analyze the data. The research findings revealed that applying the CPD procedure significantly elevated the frequencies of tail flicking, head shaking, and kicking, resulted in increases in respiratory rate, heart rate, daily active steps, and food intake and a decrease in MNT, and led to alterations in hematological markers, including platelet counts, mean platelet volume, prostaglandin E2, constitutive nitric oxide synthase, and hydroxyl radical. Considerable benefits, such as lower heart rates, higher food intake, and MNTs, as well as lower levels of white blood cell counts, lymphocyte counts, hemoglobin, mean platelet volume, prostaglandin E2, tumor necrosis factor-α, constitutive nitric oxide synthase, malondialdehyde, and hydroxyl radical, were observed in the calves that received meloxicam treatment in response to CPD. The findings of the study indicate that the co-administration of lidocaine and meloxicam provides obvious benefits in mitigating pain, inflammation, and oxidative stress in calves aged over nine days and undergoing CPD. This endorses the use of meloxicam during the disbudding and dehorning procedures of calves.

Impact of Seasonal Variations on Semen Parameters: A Retrospective Analysis of Data from Subjects Attending a Tertiary Care Fertility Centre.

Seasonal variations in semen parameters have been detected in many previous studies, mostly conducted in the West and Mediterranean countries. Located in a tropical region, we have only three seasons - summer, winter and rainy season. Literature search did not reveal studies from Indian subcontinent. Our objective was to find if our climate produced seasonal variations in semen parameters such as sperm concentration (SC), total motile SC, morphology and vitality, which may have implications in fertility management. This is a descriptive study, conducted at a tertiary level hospital. Semen analysis reports of male partners of all infertile couples during the 4-year period from 2019 to 2022 were analysed. The data were collected from records of all infertile couples registered for the treatment in the department during the study period. Semen analysis reports of male partners of all infertile couples attending outpatient department of the Reproductive Medicine Department during the 4-year period from January 2019 to December 2022 were collected. The data of azoospermic and severe oligospermic (<5 million/mL) men and those receiving hormone treatment were excluded. Data were analysed using SPSS 23 and variables expressed as mean and standard deviation. Changes in mean values over years and over seasons were evaluated using F-test. Post hoc analysis was done using Sidak method. P < 5% was considered statistically significant. The data of 2326 patients were analysed. SC was lowest during summer but was not statistically significant. Sluggishly motile sperm per cent was maximum in rainy season (P = 0.002). Post hoc analysis showed significant variations in summer samples compared to both rainy and winter seasons. Head defect (HD) and tail defects showed a significant seasonal variation (P = 0.011 and P = 0.024, respectively), lowest HD seen in rainy season. Semen parameters showed seasonal variations, with favourable features in colder climates, and may need to be considered in infertility management, especially if the male is oligospermic.

Knowledge graph embedding by fusing multimodal content via cross-modal learning.

Knowledge graph embedding aims to learn representation vectors for the entities and relations. Most of the existing approaches learn the representation from the structural information in the triples, which neglects the content related to the entity and relation. Though there are some approaches proposed to exploit the related multimodal content to improve knowledge graph embedding, such as the text description and images associated with the entities, they are not effective to address the heterogeneity and cross-modal correlation constraint of different types of content and network structure. In this paper, we propose a multi-modal content fusion model (MMCF) for knowledge graph embedding. To effectively fuse the heterogenous data for knowledge graph embedding, such as text description, related images and structural information, a cross-modal correlation learning component is proposed. It first learns the intra-modal and inter-modal correlation to fuse the multimodal content of each entity, and then they are fused with the structure features by a gating network. Meanwhile, to enhance the features of relation, the features of the associated head entity and tail entity are fused to learn relation embedding. To effectively evaluate the proposed model, we compare it with other baselines in three datasets, i.e., FB-IMG, WN18RR and FB15k-237. Experiment result of link prediction demonstrates that our model outperforms the state-of-the-art in most of the metrics significantly, implying the superiority of the proposed method.

Holştayn ve Simmental İneklerinde Barınak ve Hayvan Hijyeninin Süt Verimi, Süt Bileşimi ve Mastitis ile İlişkisi

This study was conducted to determine the effect of barn hygiene on animal hygiene in Holstein and Simmental cows and the relationship between animal hygiene and milk yield, milk composition and somatic cell count (SCC). In the study, some hygiene traits of four different barns with 40 heads of Holstein and Simmental cows in the early and middle lactation period, the degree of cleanliness of the upper rear leg, lower rear leg, abdomen, udder and tail head of cows, the milk yield and composition of animals, and the SCC were determined. In the study, it was determined that bedding was more dirtiness in Holstein barns than Simmental barns. In terms of body hygiene, breed and breed X lactation period interaction were determined to be effective (P

The first peptide derivatives of dioxybiphenyl-bridged spiro cyclotriphosphazenes: In vitro cytotoxicity activities and DNA damage studies

In this study, we aimed to synthesize new peptide-substituted cyclotriphosphazenes from a series of tyrosine-based peptides and dioxyphenyl-substituted spirocyclotriphosphazenes, and to evaluate their in vitro cytotoxicity and genotoxicity activities. Genotoxicity studies were conducted to understand whether the cytotoxic compounds cause cell death through DNA damage. The structures of the novel series of phosphazenes were characterized by FT-IR, elemental analysis, MS, 1D (31P, 1H, and 13C-APT NMR), and 2D (HETCOR) NMR spectroscopic techniques. In vitro cytotoxic activities were carried out against human breast (MCF-7), ovarian (A2780), prostate (PC-3), colon (Caco-2) cancer cell lines and human normal epithelial cell line (MCF-10A) at different concentrations by using an MTT assay. The compounds showed considerable reductions in cell viability against all human cancer cell lines. Especially, the compounds exhibited notable effects in A2780 cell lines (p < 0.05). The IC50 values of the compounds in the A2780 cell line were calculated to be 1.914 µM for TG, 20.21 µM for TV, 20.45 µM for TA, 4.643 µM for TP, 5.615 µM for BTG, 1.047 µM for BTV, 27.02 µM for BTA, 0.7734 µM for BTP, 21.5 µM for DTG, 1.65 µM for DTV, 2.89 µM for DTA and 4.599 µM for DTP. DNA damage studies of the compounds were conducted by the comet assay method using tail length, tail density, olive tail moment, head length, and head density parameters, and the results showed that the cell death occurred through DNA damage mechanism. In a nutshell, these compounds show promising cytotoxic effects and can be considered powerful candidate molecules for pharmaceutical applications.

Diffuse radio source candidate in CIZA J1358.9−4750

AbstractWe report on results of our upgraded Giant Metrewave Radio Telescope (uGMRT) observations for an early-stage merging galaxy cluster, CIZA J1358.9−4750 (CIZA1359), in Band-3 (300–500 MHz). We achieved the image dynamic range of ∼38000 using the direction dependent calibration and found a candidate of diffuse radio emission at 4σrms significance. The flux density of the candidate at 400 MHz, 24.04 ± 2.48 mJy, is significantly positive compared to noise, where its radio power, 2.40 × 1024 W Hz−1, is consistent with those of typical diffuse radio sources of galaxy clusters. The candidate is associated with a part of the X-ray shock front at which the Mach number reaches its maximum value of $\mathcal {M}\sim 1.7$. The spectral index (Fν ∝ να) of the candidate, α = −1.22 ± 0.33, is in agreement with an expected value derived from the standard diffusive shock acceleration (DSA) model. However, such a low Mach number with a short acceleration time would require seed cosmic rays supplied from active galactic nucleus (AGN) activities of member galaxies, as suggested in some other clusters. Indeed, we found seven AGN candidates inside the diffuse source candidate. Assuming the energy equipartition between magnetic fields and cosmic rays, the magnetic field strength of the candidate was estimated to be 2.1 μG. We also find head–tail galaxies and radio phoenixes or fossils near CIZA1359.

Inhibition of the cholesterol transporter ABCA1 by probucol decreases capacitation and tyrosine phosphorylation of dog spermatozoa, and is dose dependent

The ATP binding cassette (ABC) transporter molecule ABCA1 participates in the cholesterol transport within and through cell membranes. We recently demonstrated that in dog spermatozoa, capacitation could be decreased with probucol (PRO), an ABCA1 specific antagonist. In this study, a dose-effect relationship of PRO on dog sperm capacitation, tyrosine phosphorylation and cholesterol efflux from the sperm plasma membrane was investigated. A total of 16 ejaculates from dogs of different breeds, aged 2–4 years were used. Sperm motility and membrane integrity in the main fraction was determined by CASA. Samples were stained with a boron dipyrromethene difluoride (BODIPY) fluorophore (P9672, Sigma- Aldrich, A) diluted in DMSO at a final concentration of 0.4 μM. All samples were divided into 5 aliquots, with 0, 100, 250, 500 and 1000 μM of PRO. After incubation at 37 °C for 2 h, PI was added and flow cytometry performed. All aliquots were examined for capacitation and acrosome reaction by using the CTC assay and tyrosine phosphorylation (TP). Membrane integrity was measured in all aliquots to investigate the effect of PRO on cell membranes. Membrane integrity did not differ between controls (0 μM), and 100, 250 and 500 μM PRO, but decreased with 1000 μM PRO (p < 0.05). Increasing PRO concentration decreased the percentage alive cells with cholesterol efflux per PRO group (0 μM: 77.8 ± 10.6%, 100 μM: 63.7 ± 11.7%, 250 μM: 52.1 ± 12.9%, 500 μM: 37.7 ± 11.6%, 1000 μM: 33.1 ± 14.4%; p < 0.05), decreased head and entire tail phosphorylated cells (0 μM: 34.6%, 1000 μM: 5.1% p < 0.05); and decreased the percentage capacitated cells (maximum with PRO 500 μM: capacitated vs. control: 54.2 ± 17% vs 25 ± 7.7%, p < 0.05). Conclusion: PRO decreased the cholesterol efflux, and decreased tyrosine phosphorylation and capacitation in a dose-dependent manner. This suggests a strong involvement of the ABCA1 transporter in different functional aspects of sperm capacitation in dogs.

Hubble Space Telescope Observations of Tadpole Galaxies Kiso3867, SBS0, SBS1, and UM461

Tadpole galaxies are metal-poor dwarfs with typically one dominant star-forming region, giving them a head–tail structure when inclined. A metallicity drop in the head suggests that gas accretion with even lower metallicity stimulated the star formation. Here we present multiband Hubble Space Telescope WFC3 and Advanced Camera for Surveys images of four nearby (<25 Mpc) tadpoles, SBS0, SBS1, Kiso3867, and UM461, selected for their clear metallicity drops shown in previous spectroscopic studies. The properties of the star complexes and compact clusters are measured. Each galaxy contains from three to 10 young stellar complexes with 103–105 M ⊙ of stars ∼3–10 Myr old. Between the complexes, the disk has a typical age of ∼3 Gyr. Numerous star clusters cover the galaxies, both inside and outside the complexes. The combined cluster mass function, made by normalizing the masses and counts before stacking, is a power law with a slope of −1.12 ± 0.14 on a log–log plot and the combined distribution function of cluster lifetime decays with age as t −0.65±0.24. A comparison between the summed theoretical Lyman continuum (LyC) emission from all the clusters, given their masses and ages, is comparable to or exceeds the LyC needed to excite the observed Hα in some galaxies, suggesting LyC absorption by dust or undetected gas in the halo, or perhaps galaxy escape.

Taxonomy-Aware Prototypical Network for Few-Shot Relation Extraction

Relation extraction aims to predict the relation triple between the tail entity and head entity in a given text. A large body of works adopt meta-learning to address the few-shot issue faced by relation extraction, where each relation category only contains few labeled data for demonstration. Despite promising results achieved by existing meta-learning methods, these methods still struggle to distinguish the subtle differences between different relations with similar expressions. We argue this is largely owing to that these methods cannot capture unbiased and discriminative features in the very few-shot scenario. For alleviating the above problems, we propose a taxonomy-aware prototype network, which consists of a category-aware calibration module and a task-aware training strategy module. The former implicitly and explicitly calibrates the representation of prototype to become sufficiently unbiased and discriminative. The latter balances the weight between easy and hard instances, which enables our proposal to focus on data with more information during the training stage. Finally, comprehensive experiments are conducted on four typical meta tasks. Furthermore, our proposal presents superiority over the competitive baselines with an improvement of 3.30% in terms of average accuracy.