Effect of Vanadium Oxide on the Crystallization of CaO-Al2O3-SiO2 Glass.

This study investigated the effect of vanadium oxide on the crystallization of CaO-Al2O3-SiO2 (CAS) glass. Specifically, this study subjected CAS glass-ceramics (GCs) with precipitated hexagonal platy particles of metastable CaAl2Si2O8 (CAS GC-H), a layered crystal, that was prepared using metallic molybdenum (Mo) particles as nucleation agents. When the parent glass of CAS GC-H was crystallized with the addition of vanadium oxide in the 0.052-0.21 wt % range, the obtained platy particles of metastable CaAl2Si2O8 displayed an increase in the aspect ratio from 20 to 15 compared with conventional CAS GC-Hs. In addition, no crystallization occurred in the CAS glass with vanadium oxide in the 0.052-0.21 wt % range in the absence of metallic Mo particles. Meanwhile, a CAS glass containing 1.0 wt % vanadium oxide without the addition of metallic Mo particles showed the precipitation of metastable CaAl2Si2O8. Therefore, these results indicated that the aspect ratio of layered crystals in glass was controlled by the addition of a relatively small content of vanadium oxide, and a new nucleation agent for the precipitation of metastable CaAl2Si2O8 in CAS glass using a relatively high content of vanadium oxide was developed.

Effect of carbon on the co-presence of metallic tungsten as a nucleation agent and Eu2+ in glass: crystallization of CaO-Al2O3-SiO2 glass probed with Eu2+ luminescence.

This study demonstrated simple redox control in glasses by improving the method used to added glass raw materials. Specifically, the effect of carbon on the co-presence of metallic tungsten (W) particles as nucleation agents and Eu2+ ions in CaO-Al2O3-SiO2 (CAS) glass was investigated via their crystallization to form CAS glass-ceramics (GCs). In this study, the glass specimens were prepared by mixing glass cullet containing metallic W particles and Eu2+ ions, respectively, with a glass batch containing carbon. Whereas the glass specimen was yellowish because of the presence of Eu2+ when carbon was not added during the remelting process, the glass specimen prepared with carbon was black because of the presence of metallic W particles. In addition, this specimen displayed the 470 nm emission band in its fluorescence spectrum recorded under 393 nm excitation, which was attributed to the presence of Eu2+. According to the fluorescence and transmission spectra, the glass specimen showed a darker coloration and more intense 470 nm emission band compared with the specimen prepared by the conventional melting method that included a remelting process. These results indicated that metallic W and Eu2+ were reduced with greater efficiency by the melting method that involved mixing the glass cullet and batch. In addition, the heat-treated glass specimen prepared by the aforementioned mixing method contained a greater amount of metastable CaAl2Si2O8 with increasing heat treatment time as revealed by X-ray diffraction analysis and scanning electron microscopy observation. The intensity of the 470 nm emission band decreased with increasing intensity of the band at 420 nm because of the incorporation of Eu2+ into the crystalline phase, and the increase in intensity of the 420 nm band was lineally proportional to the volume fraction of the crystallized glass specimens. The results therefore indicated that the co-presence of metallic W particles as nucleation agents and Eu2+ as a probe for tracking the crystallization process was achieved by the addition of carbon during the remelting process of mixed cullet containing W and Eu2+ through crystallization of the CAS glass. The results thus demonstrate the importance of improving the method used to added glass raw materials.

Microstructural Control of CaO-Al2O3-SiO2 Glass Ceramics by Oxidation and Mixing with Nucleation Agents.

Microstructural control of CaO-Al2O3-SiO2 (CAS) glass ceramics (GCs) was achieved by oxidation and mixing with nucleation agents. CAS GCs were precipitated with hexagonal platy particles of metastable CaAl2Si2O8 layered crystals (CAS GC-H), which are typically prepared under a reductive atmosphere that forms metallic Mo or W particles as nucleation agents. The average particle size of crystals decreased significantly from 50 to 11 µm when the CAS GC-H containing metallic W particles was prepared under an oxidative atmosphere. Compared to this CAS-GC-H, the crystal particle size increased from 8-20 to 10-30 µm when the CAS GC-H was prepared by mixing glass cullet containing metallic Mo and that containing metallic W particles. These results indicate that one microstructure of CAS GC-H is controlled on the micrometer scale from a parent glass with one composition by varying the experimental conditions related to the glass melting state.

Assessment of the Crystallization Process of CaO-Al2O3-SiO2 Glass Probed with Tb3+ Luminescence.

The ratio of the intensity of Tb3+ fluorescence at 543 nm because of an electric dipole transition (5D4-7F5) relative to that at 437 nm due to a magnetic dipole transition (5D3-7F4) was determined to be proportional to the amount of metastable CaAl2Si2O8 crystals precipitated in CaO-Al2O3-SiO2 glass. The present results indicate that Tb3+ luminescence can be used as a probe to evaluate the crystallization of glass.

Morphology of subsurface cracks in glass-ceramics induced by Vickers indentation observed by synchrotron X-ray multiscale tomography.

The characterization of subsurface cracks induced by indentation is a challenge for understanding contact damage, impact, wear, erosion, and abrasion of brittle materials, because the crack pattern observable on the surface is only a part of the total crack system. Here we applied synchrotron X-ray multiscale tomography to observe the morphology of subsurface cracks produced by Vickers indentation in a novel CaO-Al2O3-SiO2 glass-ceramic with plate-like crystals forming a house-of-cards microstructure. It revealed a diverse type of crack systems around the semispherical microcrack zone beneath the indent, including a new mode II inclined lateral crack driven by the maximum shear stress. Tomography images provided knowledge on how the heterogeneous microstructure affected the toughening processes such as crack deflection, crack bridging, and microcracking.

[Anomalous Origin of the Right Coronary Artery from the Pulmonary Artery Treated with Fistula Closure and Coronary Artery Bypass Grafting:Report of a Case].

An anomalous origin of the right coronary artery from the pulmonary artery (ARCAPA) is a rare congenital disease, and it sometimes remains unnoticed until cardiac symptoms appear in adulthood. We report an adult case of surgically treated ARCAPA. A 72-year-old male was diagnosed with ARCAPA by examination for heart failure. The origin of the right coronary artery (RCA) was dilated, and ischemic change was found in the RCA area by myocardial scintigraphy. Therefore, coronary artery bypass grafting to distal RCA was performed at first, then the fistula was closed using an autologous pericardial patch, and the dilated origin of RCA was resected. Postoperative scintigraphy showed disappearance of the ischemic pattern, and the patient was discharged without any symptom of heart failure.

Testosterone regulation on quiescin sulfhydryl oxidase 2 synthesis in the epididymis.

The epididymis is an androgen-responsive organ, whose structure and functions are modulated by the coordination between androgen and epididymal cues. Highly regulated molecular interaction within the epididymis is required to support viable sperm development necessary for subsequent fertilization. In the present study, we extended our earlier findings on a promising epididymal protein, quiescin sulfhydryl oxidase 2 (QSOX2), and demonstrated a positive correlation between testosterone and QSOX2 protein synthesis through the use of loss- and restore-of-function animal models. Moreover, based on transcriptomic analyses and 2D culture system, we determined that an additional polarized effect of glutamate is indispensable for the regulatory action of testosterone on QSOX2 synthesis. In conclusion, we propose noncanonical testosterone signaling supports epididymal QSOX2 protein synthesis, providing a novel perspective on the regulation of sperm maturation within the epididymis.

Long-term effects of school barefoot running program on sprinting biomechanics in children: A case-control study.

BACKGROUND: The acute changes of running biomechanics in habitually shod children when running barefoot have been demonstrated. However, the long-term effects of barefoot running on sprinting biomechanics in children is not well understood. RESEARCH QUESTION: How does four years of participation in a daily school barefoot running program influence sprint biomechanics and stretch-shortening cycle jump ability in children? METHODS: One hundred and one children from barefoot education school (age, 11.2 ±â€¯0.7 years-old) and 93 children from a control school (age, 11.1 ±â€¯0.7 years-old) performed 50 m maximal shod and barefoot sprints and counter movement jump and five repeated-rebound jumping. To analyse sprint kinematics, a high-speed camera (240 fps) was used. In addition, foot strike patterns were evaluated by using three high-speed cameras (300 fps). Jump heights for both jump types and the contact times for the rebound jump were measured using a contact mat system. Two-way mixed ANOVA was used to examine the effect of school factor (barefoot education school vs control school) and footwear factor (barefoot vs shod) on the sprinting biomechanics. RESULTS: Sprinting biomechanics in barefoot education school children was characterised by significantly shorter contact times (p = 0.003) and longer flight times (p = 0.005) compared to control school children regardless of footwear condition. In shod sprinting, a greater proportion of barefoot education school children sprinted with a fore-foot or mid-foot strike compared to control school children (p < 0.001). Barefoot education school children also had a significantly higher rebound jump height (p = 0.002) and shorter contact time than control school children (p = 0.001). SIGNIFICANCE: The results suggest that school-based barefoot running programs may improve aspects of sprint biomechanics and develop the fast stretch-shortening cycle ability in children. In order to confirm this viewpoint, adequately powered randomised controlled trials should be conducted.

Disclosing crystal nucleation mechanism in lithium disilicate glass through molecular dynamics simulations and free-energy calculations.

Unraveling detailed mechanism of crystal nucleation from amorphous materials is challenging for both experimental and theoretical approaches. In this study, we have examined two methods to understand the initial stage of crystal precipitation from lithium disilicate glasses using molecular dynamics simulations. One of the methods is a modified exploring method to find structurally similar crystalline clusters in the glass models, enabling us to find three different embryos, such as Li2Si2O5 (LS2), Li2SiO3 (LS) and Li3PO4 (LP), in the 33Li2O·66SiO2·1P2O5 glass (LS2P1), in which P2O5 is added as a nucleating agent. Interestingly, LS2 and LP crystals were found inside the LS2P1 glass while LS crystal appeared on the glass surface, which agrees with experimental observations. The other method is free energy calculation using a subnano-scale spherical crystal embedded in the glass model. This method, which we called Free-Energy Seeding Method (FESM), allows us to evaluate free energy change as a function of crystal radius and to identify critical size of the crystal precipitation. The free energy profiles for LS and LS2 crystal nuclei in the LS2 glass models possess maximum energy at a critical radius as expected by classical nucleation theory. Furthermore, the critical radius and the energy barrier height agree well with recent experimental investigation, proving the applicability of this method to design glass-ceramics by atomistic modeling.

Mating-induced increase in Kiss1 mRNA expression in the anteroventral periventricular nucleus prior to an increase in LH and testosterone release in male rats.

Kisspeptin has an indispensable role in gonadotropin-releasing hormone/gonadotropin secretion in mammals. In rodents, kisspeptin neurons are located in distinct brain regions, namely the anteroventral periventricular nucleus-periventricular nucleus continuum (AVPV/PeN), arcuate nucleus (ARC), and medial amygdala (MeA). Among them, the physiological role of AVPV/PeN kisspeptin neurons in males has not been clarified yet. The present study aims to investigate the acute effects of the olfactory and/or mating stimulus with a female rat on hypothalamic and MeA Kiss1 mRNA expression, plasma luteinizing hormone (LH) and testosterone levels in male rats. Intact male rats were exposed to the following stimuli: exposure to clean bedding; exposure to female-soiled bedding as a female-olfactory stimulus; exposure to female-soiled bedding and mating stimulus with a female rat. The mating stimulus significantly increased the number of the AVPV/PeN Kiss1 mRNA-expressing cells in males within 5 minutes after the exposure, and significantly increased LH and testosterone levels, followed by an increase in male sexual behavior. Whereas, the males exposed to female-soiled bedding showed a moderate increase in LH levels and no significant change in testosterone levels and the number of the AVPV/PeN Kiss1 mRNA-expressing cells. Importantly, none of the stimuli affected the number of Kiss1 mRNA-expressing cells in the ARC and MeA. These results suggest that the mating-induced increase in AVPV/PeN Kiss1 mRNA expression may be, at least partly, involved in stimulating LH and testosterone release, and might consequently ensure male mating behavior. This study would be the first report suggesting that the AVPV/PeN kisspeptin neurons in males may play a physiological role in ensuring male reproductive performance.

Peripheral administration of SB223412, a selective neurokinin-3 receptor antagonist, suppresses pulsatile luteinizing hormone secretion by acting on the gonadotropin-releasing hormone pulse generator in estrogen-treated ovariectomized female goats.

Accumulating evidence suggests that KNDy neurons located in the hypothalamic arcuate nucleus (ARC), which are reported to express kisspeptin, neurokinin B, and dynorphin A, are indispensable for the gonadotropin-releasing hormone (GnRH) pulse generation that results in rhythmic GnRH secretion. The aims of the present study were to investigate the effects of peripheral administration of the neurokinin 3 receptor (NK3R/TACR3, a receptor for neurokinin B) antagonist, SB223412, on GnRH pulse-generating activity and pulsatile luteinizing hormone (LH) secretion in ovariectomized Shiba goats treated with luteal phase levels of estrogen. The NK3R antagonist was infused intravenously for 4 h {0.16 or 1.6 mg/(kg body weight [BW]·4 h)} during which multiple unit activity (MUA) in the ARC was recorded, an electrophysiological technique commonly employed to monitor GnRH pulse generator activity. In a separate experiment, the NK3R antagonist (40 or 200 mg/[kg BW·day]) was administered orally for 7 days to determine whether the NK3R antagonist could modulate pulsatile LH secretion when administered via the oral route. Intravenous infusion of the NK3R antagonist significantly increased the interval of episodic bursts of MUA compared with that of the controls. Oral administration of the antagonist for 7 days also significantly prolonged the interpulse interval of LH pulses. The results of this study demonstrate that peripheral administration of an NK3R antagonist suppresses pulsatile LH secretion by acting on the GnRH pulse generator, suggesting that NK3R antagonist administration could be used to modulate reproductive functions in ruminants.

Conditional kisspeptin neuron-specific Kiss1 knockout with newly generated Kiss1-floxed and Kiss1-Cre mice replicates a hypogonadal phenotype of global Kiss1 knockout mice.

The present study aimed to evaluate whether novel conditional kisspeptin neuron-specific Kiss1 knockout (KO) mice utilizing the Cre-loxP system could recapitulate the infertility of global Kiss1 KO models, thereby providing further evidence for the fundamental role of hypothalamic kisspeptin neurons in regulating mammalian reproduction. We generated Kiss1-floxed mice and hypothalamic kisspeptin neuron-specific Cre-expressing transgenic mice and then crossed these two lines. The conditional Kiss1 KO mice showed pubertal failure along with a suppression of gonadotropin secretion and ovarian atrophy. These results indicate that newly-created hypothalamic Kiss1 KO mice obtained by the Cre-loxP system recapitulated the infertility of global Kiss1 KO models, suggesting that hypothalamic kisspeptin, but not peripheral kisspeptin, is critical for reproduction. Importantly, these Kiss1-floxed mice are now available and will be a valuable tool for detailed analyses of roles of each population of kisspeptin neurons in the brain and peripheral kisspeptin-producing cells by the spatiotemporal-specific manipulation of Cre expression.

Inducible Kiss1 knockdown in the hypothalamic arcuate nucleus suppressed pulsatile secretion of luteinizing hormone in male mice.

Accumulating evidence suggests that kisspeptin-GPR54 signaling is indispensable for gonadotropin-releasing hormone (GnRH)/gonadotropin secretion and consequent reproductive functions in mammals. Conventional Kiss1 knockout (KO) mice and rats are reported to be infertile. To date, however, no study has investigated the effect of inducible central Kiss1 KO/knockdown on pulsatile gonadotropin release in male mammals. Here we report an in vivo analysis of inducible conditional Kiss1 knockdown male mice. The mice were generated by a bilateral injections of either adeno-associated virus (AAV) vectors driving Cre recombinase (AAV-Cre) or AAV vectors driving GFP (AAV-GFP, control) into the hypothalamic arcuate nucleus (ARC) of Kiss1-floxed male mice, in which exon 3 of the Kiss1 gene were floxed with loxP sites. Four weeks after the AAV-Cre injection, the mice showed a profound decrease in the both number of ARC Kiss1-expressing cells and the luteinizing hormone (LH) pulse frequency. Interestingly, pulsatile LH secretion was apparent 8 weeks after the AAV-Cre injection despite the suppression of ARC Kiss1 expression. The control Kiss1-floxed mice infected with AAV-GFP showed apparent LH pulses and Kiss1 expression in the ARC at both 4 and 8 weeks after the AAV-GFP injection. These results with an inducible conditional Kiss1 knockdown in the ARC of male mice suggest that ARC kisspeptin neurons are responsible for pulsatile LH secretion in male mice, and indicate the possibility of a compensatory mechanism that restores GnRH/LH pulse generation.

Retinoblastoma binding protein 7 is involved in Kiss1 mRNA upregulation in rodents.

Kisspeptin, encoded by Kiss1, is essential for reproduction in mammals. Kiss1 expression is regulated by estrogen via histone acetylation in the Kiss1 promotor region. Thus, elucidation of histone modification factor(s) involved in the regulation of Kiss1 expression is required to gain further understanding of the mechanisms of its control. The RNA-seq analysis of isolated kisspeptin neurons, obtained from the arcuate nucleus (ARC) of female rats, revealed that Rbbp7, encoding retinoblastoma binding protein 7 (RBBP7), a member of histone modification and chromatin remodeling complexes, is highly expressed in the ARC kisspeptin neurons. Thus, the present study aimed to investigate whether RBBP7 is involved in Kiss1 expression. Histological analysis using in situ hybridization (ISH) revealed that Rbbp7 expression was located in several hypothalamic nuclei, including the ARC and the anteroventral periventricular nucleus (AVPV), where kisspeptin neurons are located. Double ISH for Rbbp7 and Kiss1 showed that a majority of kisspeptin neurons (more than 85%) expressed Rbbp7 mRNA in both the ARC and the AVPV of female rats. Further, Rbbp7 mRNA knockdown significantly decreased in vitro expression of Kiss1 in a mouse immortalized kisspeptin neuronal cell line (mHypoA-55). Estrogen treatment significantly decreased and increased Kiss1 mRNA levels in the ARC and AVPV of ovariectomized female rats, respectively, but failed to affect Rbbp7 mRNA levels in both the nuclei. Taken together, these findings suggest that RBBP7 is involved in the upregulation of Kiss1 expression in kisspeptin neurons of rodents in an estrogen-independent manner.

Morphological analysis for neuronal pathway from the hindbrain ependymocytes to the hypothalamic kisspeptin neurons.

Hindbrain ependymocytes are postulated to have a glucose-sensing role in regulating gonadal functions. Previous studies have suggested that malnutrition-induced suppression of gonadotropin secretion is mediated by noradrenergic inputs from the A2 region in the solitary tract nucleus to the paraventricular nucleus (PVN), and by corticotropin-releasing hormone (CRH) release in the hypothalamus. However, no morphological evidence to indicate the neural pathway from the hindbrain ependymocytes to hypothalamic kisspeptin neurons, a center for reproductive function in mammals, currently exists. The present study aimed to examine the existence of a neuronal pathway from the hindbrain ependymocytes to kisspeptin neurons in the arcuate nucleus (ARC) and anteroventral periventricular nucleus (AVPV). To determine this, wheat-germ agglutinin (WGA), a trans-synaptic tracer, was injected into the fourth ventricle (4V) in heterozygous Kiss1-tandem dimer Tomato (tdTomato) rats, where kisspeptin neurons were visualized by tdTomato fluorescence. 48 h after the WGA injection, brain sections were taken from the forebrain, midbrain and hindbrain and subjected to double immunohistochemistry for WGA and dopamine ß-hydroxylase (DBH) or CRH. WGA immunoreactivities were found in vimentin-immunopositive ependymocytes of the 4V and the central canal (CC), but not in the third ventricle. The WGA immunoreactivities were detected in some tdTomato-expressing cells in the ARC and AVPV, DBH-immunopositive cells in the A1-A7 noradrenergic nuclei, and CRH-immunopositive cells in the PVN. These results suggest that the hindbrain ependymocytes have neuronal connections with the kisspeptin neurons, most probably via hindbrain noradrenergic and CRH neurons to relay low energetic signals for regulation of reproduction.

Severe incomplete fusion of the Müllerian ducts influences reproduction in Holstein cattle.

Fusion failure of the Müllerian ducts is thought to occur congenitally in cattle. We aimed to elucidate the contribution of incomplete fusion of the Müllerian ducts to reproductive difficulties in dairy cattle. We observed the vaginas of Holstein cattle to classify the anomalies into mild and severe types, based on severity of incomplete fusion, and recorded information about the cattle at the time of artificial insemination (AI) or embryo transfer. Of the 1054 Holstein cattle examined, 22 (2.09%) individuals showed incomplete fusion of the Müllerian ducts. Among them, 17 (77.3%) had mild type and 5 (22.7%) had severe type incomplete fusion. We analyzed the changes in the prevalence of these anomalies in previous studies and the present study. The prevalence of incomplete fusion of the Müllerian ducts varied from 0% to 6.98% by dairy breed or region. Linear regression analysis showed that the change in the prevalence over time was not statistically significant, with a regression coefficient of -0.04% per year (r2 = 0.27; P = 0.07). The effect of incomplete fusion of the Müllerian ducts on reproductive performance was evaluated by univariate analysis: first service pregnancy rate, number of services, and days from first service to pregnancy were significantly affected in the heifers with the severe types. We next analyzed the effect of incomplete fusion of the Müllerian ducts on conception, using logistic regression analysis. Mild and severe types of incomplete fusion of the Müllerian ducts were selected as explanatory variables, along with heat stress, parity, the number of previous services, AI after ovulation, and sex-sorted semen. The severe types (OR = 0.24, P = 0.03), but not the mild types (OR = 1.01, P = 0.98), were significantly associated with conception. In the present study, we divided the incomplete fusion of the Müllerian ducts by severity and demonstrated that the severe types had a significant effect on poor conception in Holstein cattle. Since the adjusted odds of conception of the severe types of incomplete fusion of the Müllerian ducts were approximately 4 times lower than those of the normal cattle, it is important to determine severe incomplete fusion of the Müllerian ducts prior to service.

The roles of kisspeptin in the mechanism underlying reproductive functions in mammals.

Kisspeptin, identified as a natural ligand of GPR54 in 2001, is now considered as a master regulator of puberty and subsequent reproductive functions in mammals. Our previous studies using Kiss1 knockout (KO) rats clearly demonstrated the indispensable role of kisspeptin in gonadotropin-releasing hormone (GnRH)/gonadotropin secretion. In addition, behavioral analyses of Kiss1 KO rats revealed an organizational effect of kisspeptin on neural circuits controlling sexual behaviors. Our studies using transgenic mice carrying a region-specific Kiss1 enhancer-driven reporter gene provided a clue as to the mechanism by which estrogen regulates Kiss1 expression in hypothalamic kisspeptin neurons. Analyses of Kiss1 expression and gonadotropin secretion during the pubertal transition shed light on the mechanism triggering GnRH/gonadotropin secretion at the onset of puberty in rats. Here, we summarize data obtained from the aforementioned studies and revisit the physiological roles of kisspeptin in the mechanism underlying reproductive functions in mammals.

Kinematic characteristics of barefoot sprinting in habitually shod children.

BACKGROUND: Anecdotally, a wide variety of benefits of barefoot running have been advocated by numerous individuals. The influence of the alterations in the properties of the shoe on the running movement has been demonstrated in adults at submaximal jogging speeds. However, the biomechanical differences between shod and barefoot running in children at sprinting speeds and the potential developmental implications of these differences are still less examined. The purpose was to determine the potential differences in habitually shod children's sprint kinematics between shod and barefoot conditions. METHODS: Ninety-four children (51 boys and 43 girls; 6-12 years-old; height, 135.0 ± 0.12 m; body mass, 29.0 ± 6.9 kg) performed 30 m maximal sprints from standing position for each of two conditions (shod and barefoot). To analyze sprint kinematics within sagittal plane sprint kinematics, a high-speed camera (300 fps) was set perpendicular to the runway. In addition, sagittal foot landing and take-off images were recorded for multiple angles by using five high-speed cameras (300 fps). Spatio-temporal variables, the kinematics of the right leg (support leg) and the left leg (recovery leg), and foot strike patterns: rear-foot strike (RFS), mid-foot strike (MFS), and fore-foot strike (FFS) were investigated. The paired t-test was used to test difference between shod and barefoot condition. RESULTS: Barefoot sprinting in habitually shod children was mainly characterized by significantly lower sprint speed, higher step frequency, shorter step length and stance time. In shod running, 82% of children showed RFS, whereas it decreased to 29% in barefoot condition. The touch down state and the subsequent joint movements of both support and recovery legs during stance phase were significantly altered when running in condition with barefoot. DISCUSSION: The acute effects of barefoot sprinting was demonstrated by significantly slower sprinting speeds that appear to reflect changes in a variety of spatiotemporal parameters as well as lower limb kinematics. It is currently unknown whether such differences would be observed in children who typically run in bare feet and what developmental benefits and risks may emerge from increasing the proportion of barefoot running and sprinting in children. Future research should therefore investigate potential benefits that barefoot sprinting may have on the development of key physical fitness such as nerve conduction velocity, muscular speed, power, and sprinting technique and on ways to minimize the risk of any acute or chronic injuries associated with this activity.

Mouse quiescin sulfhydryl oxidases exhibit distinct epididymal luminal distribution with segment-specific sperm surface associations.

Sulfhydryl oxidation is part of the sperm maturation process essential for the acquisition of sperm fertilization competency and its structural stabilization; however, the specific sulfhydryl oxidases that fulfill these roles have yet to be identified. In this study, we investigate the potential involvement of one atypical thiol oxidase family called quiescin Q6/sulfhydryl oxidase (QSOX) using the mouse epididymis as our model system. With multidisciplinary approaches, we show that QSOX isoform 1 and 2 exhibit complementary distribution throughout the epididymal duct, but that each variant possesses distinct subcellular localization within the epididymal principal cells. While QSOX2 was exclusively present in the Golgi apparatus of the caput and corpus epididymis, QSOX1c, the most profusely express QSOX1 variant, was abundantly present in the cauda luminal fluids. Moreover, immunohistochemistry studies together with proteomic identification in isolated epididymosomes provided evidence substantiating the release of QSOX2, but not QSOX1c, via an apocrine secretory pathway. Furthermore, we demonstrate for the first time, distinct association of QSOX1c and QSOX2 with the sperm acrosome and implantation fossa, during different stages of their epididymal maturation. In conclusion, our study provides the first comprehensive comparisons between QSOX1 and QSOX2 in the mouse epididymis, revealing their distinct epididymal distribution, cellular localization, mechanisms of secretion and sperm membrane association. Together, these data suggest that QSOX1 and QSOX2 have discrete biological functions in male germ cell development.

Structure and zonal expression of olfactory receptors in the olfactory epithelium of the goat, Capra hircus.

The mammalian olfactory system employs sophisticated mechanisms to detect and recognize an extensive range of smells. In rodents, the olfactory epithelium (OE), situated within the nasal cavity, mainly comprises four defined endoturbinates and several ectoturbinates. Olfactory receptors (ORs) belong to a large family, comprising over 1,000 genes in rodents, which are expressed in olfactory sensory neurons in the OE that detect odor molecules. The rodent OE is divided into four topographically distinct zones, defined by individual OR distribution. However, although the structural complexity and the zonal organization of mammalian OE may contribute to successfully interpreting olfactory information, it remains poorly understood. In this study, we investigated the nasal cavity structure and zonal organization of the OE in goats. Morphological observations revealed that the goat nasal cavity possessed well-developed endoturbinates and ectoturbinates and had a structure similar to that of rodents and sheep, previously reported in other studies. In situ hybridization was used to analyze the expression pattern of ORs, NADPH:quinone oxidoreductase 1, and olfactory cell adhesion molecules as markers of zonal organization in the goat OE. Based on the expression patterns of these genes, we concluded that the goat OE was divided into four zones. The well-developed structure of the nasal cavity and distribution of each OR in the OE were similar to those found in rodents, suggesting that these features were highly conserved between mammals and may have fundamental roles in discriminating among numerous odor molecules in the environment.