Search Results (58)

This paper introduces a new class of multiple-objective control models driven by path-independent curvilinear integrals involving the partial derivatives of the control variable. We investigate its solution set by considering a dual problem. Various duality results are formulated and proved in order to study and investigate the relationships between the set of solutions for these two variational control problems. Specifically, first, we establish that the value of the cost functional associated with the primal model cannot be greater than the value of the cost functional associated with the dual model. Secondly, the following two results present a strong-type duality between the variational models considered. At the end, we illustrate the main findings of the current paper with a numerical example. Full article

This study aimed to investigate the effects of adding different levels of punicalagin or oleuropein to TRIS diluent on the quality of frozen–thawed semen from Najdi rams. Semen was diluted using TRIS-based diluter with 15% egg yolk (control group); supplemented with 0.1, 0.5, or 1 mg/100 mL punicalagin (in Experiment 1); or supplemented with 1, 2.5, or 5 mg/100 mL oleuropein (in Experiment 2). The collected semen was evaluated and cryopreserved, with the motility and concentration of sperm assessed using a CASA system. The results showed that the total motile spermatozoa (TMS), percentage of progressive motile spermatozoa (PMS), curvilinear velocity (VCL), rectilinear velocity, average path velocity (VAP), linearity coefficient, straightness index, minor defects, and sperm vitality were higher in the 0.1 mg/100 mL punicalagin group (p < 0.05) than in other groups. HOST% post-thawing was significantly higher in all punicalagin groups compared to the control group (p < 0.001). The percentages of PMS, TMS, VCL, minor defects, and sperm vitality were higher in the 1 mg/100 mL oleuropein group (p < 0.05) than in other groups. Oleuropein supplementation at 5 mg/100 mL decreased VAP in cooled sperms, while all levels increased VAP post-thawing. HOST-positive sperms% post-thawing was higher in all oleuropein-treated groups than the control group (p < 0.001). Moreover, oleuropein nonsignificantly increased the acrosome integrity in cooled sperms, while higher studied concentrations of oleuropein (2.5 and 5 mg/100 mL) decreased the acrosome integrity in frozen sperms. In conclusion, adding punicalagin (0.1 mg/100 mL) or oleuropein (1 mg/100 mL) to TRIS diluent improved the quality of frozen–thawed semen from rams. Full article

The aim of this study was to investigate the effect of season (breeding vs. non-breeding) on the characteristics of warmblood stallion spermatozoa during liquid storage. Ejaculates were collected from eight stallions during the breeding and non-breeding seasons (March–July and September–December, respectively) and were diluted in an EquiPro extender. Semen was stored for up to 96 h at 5 °C. Analysis of stored sperm included the assessment of motility (CASA system), acrosomes with normal apical ridges (NAR), plasma membrane integrity (PMI), mitochondrial membrane potential (MMP), and adenosine triphosphate (ATP) content. In sperm stored for up to 24 h, the values of the following parameters were higher (p ≤ 0.05) in March-July than in September–December: progressive motility (PMOT), PMI, MMP, beat cross frequency (BCF), and linearity (LIN). The values of the studied parameters decreased during storage, and the observed changes were affected by season. The values of NAR, PMI and MMP, average path velocity (VAP), straight line velocity (VSL), and curvilinear velocity (VCL) decreased (p ≤ 0.05) after 24 h of storage during the breeding season, whereas a significant decrease in these parameters was observed after prolonged storage (48 h or longer) during the non-breeding seasons. Cooled sperm of warmblood stallions collected during the breeding season was characterized by higher initial quality than the sperm collected during the non-breeding season. However, sperm sampled during the non-breeding season appeared to be more resistant to cold shock, which increases their suitability for cold storage at 5 °C. Stallion sperm sampled in both seasons were characterized by similar suitability for liquid storage. Further research is needed to assess the fertilizing capacity of stored sperm. Full article

The low resistance of boar sperm to cryopreservation dictates that adding antioxidants and energetic substances to the diluent to improve sperm quality is necessary. This study is designed to assess the impact of various concentrations of safflower polysaccharides (SPSs; 0, 0.5, 1.0, 1.5, and 2.0 g/L) on the quality of boar sperm following freezing and thawing. The results of the study showed that the supplementation of 1.5 g/L SPS significantly enhanced the motility, average path velocity, straight-line velocity, curvilinear velocity, beat cross frequency, acrosome integrity, plasma membrane integrity, mitochondrial activity, and DNA integrity compared with the control group (p < 0.05). In addition, the supplementation of 1.5 g/L SPS significantly enhanced the total antioxidant capacity, superoxide dismutase activity, glutathione peroxidase activity, and catalase activity while significantly decreasing malondialdehyde and hydrogen peroxide content (p < 0.05). Therefore, the supplement SPS has potentially positive implications for improving the quality of cryopreserved boar sperm, and the recommended concentration is 1.5 g/L SPS. Full article

The ecological governance system has made significant progress in information technology construction, and digitization has become an important driving force in the construction of this system. This article delves into the digital construction path of ecosystem governance and elaborates on the practical application effectiveness of digitalization in the ecological governance system through two specific cases: intelligent water management and air pollution warning digital models. Furthermore, we adopt the TOE (Technology–Organization–Environment) model to integrate a collaborative theory with the concept of multi-center governance and innovatively propose a new model for nearshore ecological environment protection management. On this basis, we constructed an evaluation index system and established a theoretical model of the impact of environmental regulations on nearshore ecological efficiency. After empirical analysis, we found that the impact of environmental regulations on ecological efficiency in coastal areas presents a curvilinear characteristic. In the modern ecological governance system, organizational factors and technological factors are the two modules that have the greatest impact on system construction, accounting for 49% and 31% of the weight of the indicator system, respectively, followed by technological advantages and the urgency and feasibility of construction. Gender factors indicate that technology and organization are necessary factors that constrain institutional development. Full article

In this paper, a class of controlled variational control models is studied by considering the notion of $(q,w)-\pi$-invexity. Our aim is to investigate a solution set in the considered interval-valued controlled models. To achieve this, we establish some characterization results of solutions in the controlled interval-valued variational models. More precisely, necessary and sufficient conditions of optimality are highlighted as part of a feasible solution. To prove that the optimality conditions are sufficient, we impose generalized invariant convexity hypotheses for the involved multiple integral functionals. Finally, a duality result is provided in order to better describe the problem under study. The methodology used in this paper is a combination of techniques from the Lagrange–Hamilton theory, calculus of variations, and control theory. This study could be immediately improved by including an analysis of this class of optimization problems by using curvilinear integrals instead of multiple integrals. The independence of path imposed to these functionals and their physical significance would increase the applicability and importance of the paper. Full article

This study aimed to investigate the selective effect of the reproductive tract mucus in cows that have consistently produced offspring of a single sex on X/Y spermatozoa. We collected mucus from the reproductive tract of cows that had given calvings to offspring of the same sex, or alternated between sexes, for more than five consecutive calvings. We evaluated the pH of reproductive tract mucus. Subsequently, we conducted a spermatozoa penetration assay; the proportions of X and Y spermatozoa after penetration were then identified by dual TaqMan qPCR and flow cytometry. This was followed by in vitro fertilization and embryo sex determination experiments. Immediately afterwards, computer-aided spermatozoa analysis was employed to analyze the spermatozoa that had penetrated through different types of mucus in the reproductive tract. The analysis indicated that the reproductive tract mucus of cows consistently producing male or female calves exhibited selectivity towards X/Y spermatozoa. The differences in the pH values of the reproductive tract mucus among cows continuously producing male calves, those continuously producing female calves, and those alternately giving birth to male and female calves were not significant (p ≥ 0.05). The outcome of dual TaqMan qPCR for cows consistently producing male calves was Y: 79.29 ± 4.28% vs. X: 21.67 ± 4.53%; for cows consistently producing female calves, the equation was Y: 25.05 ± 4.88% vs. X: 75.34 ± 5.13%. The results of flow cytometry processing revealed the following proportions: for cows consistently producing male calves: Y: 83.33 ± 5.52% vs. X: 17.23 ± 4.74%; for cows consistently producing female calves: Y: 24.81 ± 4.13% vs. X: 76.64 ± 4.21%. The outcomes of embryo sex determination for cows consistently producing male calves were as follows: male embryos vs. female embryos (79.60 ± 2.87% vs. 21.07 ± 2.51%); for cows consistently producing female calves, the outcomes for male embryos vs. female embryos were 25.58 ± 3.96% vs. 75.63 ± 3.55%. Computer-aided analysis revealed that the concentration of spermatozoa penetrating the reproductive tract mucus in cows alternating between male and female calves (9.09 ± 0.72 million/mL) was significantly higher than that in cows consistently producing male calves (6.01 ± 1.19 million/mL) and cows consistently producing female calves (5.61 ± 0.60 million/mL). There were no significant differences in spermatozoa motility, the proportion of progressive motile spermatozoa, and curvilinear, straight-line, and average path velocities. Collectively, these findings indicate that the reproductive tract mucus of cows consistently producing offspring of a single sex exhibits selectivity towards either X or Y spermatozoa. This finding is of great significance for studying the impact of maternal factors on offspring sex. Full article

This study investigates the impact of nutritional supplementation on semen quality, epigenetic-related gene expression, and oxidative status in boars. Thirty boars were divided into a control group and a treatment group receiving Espermaplus (a supplement containing various vitamins, amino acids, omega-3 fatty acids, and trace elements with antioxidant properties). The experiment was performed for 12 weeks. Semen samples were collected at four moments: before starting the supplementation and after 3 weeks, 8 weeks, and 12 weeks. Spermatozoa concentration, motility, and kinematics were assessed using the CASA system. The measured parameters included curvilinear velocity—VCL; straight-line velocity—VSL; average path velocity—VAP; curvilinear distance—DCL; straight line distance—DSL; distance of average path—DAP; amplitude of lateral head displacement—ALH; beat-cross frequency—BCF; and head activity—HAC. Moreover, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity in seminal plasma, as well as the concentration of thiobarbituric acid reactive substances (TBARS), were measured to assess oxidative stress levels in boar’s seminal plasma. The expression of epigenetic-related genes such as Protamine 1 (Prm1), Protamine 2 (Prm2), and DNA-methyltransferase 3 alpha (Dnmt3a) were evaluated using real-time PCR. The treated group showed a significant increase in spermatozoa concentration (p = 0.003), total motility (p = 0.001), and progressive motility (p = 0.002) after 12 weeks compared to the control group. Kinematic parameters such as VCL, VSL, and VAP were also significantly higher (p < 0.001; p = 0.028; p < 0.001, respectively) in the treated group by the end of the experiment. SOD and GPx activities were consistently higher (p < 0.01; p < 0.001, respectively) in the treated group, indicating enhanced antioxidative capacity. TBARS levels as an indicator of lipid peroxidation and oxidative damage were significantly lower (p < 0.01) in the treated group by the end of the study. Significant changes were observed in the expression of epigenetic-related genes. The supplementation of boar diets with Espermaplus significantly improved semen quality, reduced oxidative stress, and had an impact on the expression levels of certain epigenetic-related genes, suggesting that dietary antioxidants and bioactive compounds can enhance boar semen. Full article

The Chinese rare minnow (Gobiocypris rarus), an important model fish in China, faces endangerment in the wild. Sperm cryopreservation facilitates the development of new strains and germplasm conservation, but the quality of its cryopreserved sperm remains low. This study evaluates the protective effects of different concentrations of antifreeze proteins (AFP I and AFP III) on the cryopreservation of Chinese rare minnow sperm. Cryopreserved sperm showed significant declines in progressive motility, curvilinear velocity (VCL), average path velocity (VAP), and lifespan compared to fresh sperm, except for straight-line velocity (VSL). The cryomedium containing 10 μg/mL AFP I improved these parameters to their highest levels. However, no significant difference was found in progressive motility and kinetic parameters between cryopreserved sperm with and without AFPs. Cryopreserved sperm with 10 μg/mL AFP I showed the highest plasma membrane integrity, mitochondrial activity, and DNA integrity, significantly better than without AFPs; importantly, the fertilization rate of cryopreserved sperm with 10 μg/mL AFP I was not significantly different from that of fresh sperm. These results indicate that the addition of 10 μg/mL AFP I to the cryomedium for Chinese rare minnow sperm does not improve kinetic parameters but significantly enhances sperm quality, aiding in its new strain development and germplasm conservation. Full article

In this paper, we investigate and characterize a family of optimization problems introduced by interval-valued functionals that are determined by curvilinear integrals. To this end, we first state the path independence and (strictly) $LU$ convexity properties of the considered functionals. Thereafter, we formulate the corresponding controlled variational inequalities. The main results of this paper provide some connections for the above-mentioned variational models. Since the objective functionals have a physical importance, an illustrative application is considered and studied by using the theoretical elements obtained in this study. Full article

The purpose of this study was to investigate the effects of different diluents and freezing methods on the quality of thawed sperm after cryopreservation and find an inexpensive and practical method for freezing Hu ram semen for use in inseminations under farm conditions. Ejaculates were collected from five Hu rams. In experiment I, ejaculates were diluted with eight different freezing diluents (basic diluents A, B, C, D, E, F, G, and H). After dilution and cooling, the samples were loaded into 0.25 mL straws and frozen using the liquid nitrogen fumigation method. In experiment II, diluent C was used as the basic diluent and the semen was frozen using liquid nitrogen fumigation and two program-controlled cooling methods. For analysis, frozen samples were evaluated in terms of motility parameters (total motility (TM), progressive motility (PM)), biokinetic characteristics (straight-line velocity (VSL), average path velocity (VAP), curvilinear velocity (VCL), amplitude of lateral head displacement (ALH), wobble movement coefficient (WOB), average motion degree (MAD)), reactive oxygen species (ROS) level, and membrane and acrosome integrity. In experiment I, diluent C had higher TM, PM, and acrosome and membrane integrity and lower ROS compared to other extenders (p < 0.05) except diluent A. Diluent C exhibited higher (p < 0.05) VCL, VAP, ALH, WOB, and MAD compared to diluents B, D, E, and F. In experiment II, TM and all biokinetic characteristics did not show significant differences (p > 0.05) amongst the three freezing methods. Liquid nitrogen fumigation resulted in higher (p < 0.05) PM, membrane integrity, acrosome integrity, and lower ROS level compared to the program. In conclusion, the thawed semen diluted with diluent C had higher quality compared to other diluents. The liquid nitrogen fumigation demonstrated superior semen cryopreservation effects compared to the program-controlled cooling method using diluent C. Full article

Sperm cryopreservation is a valuable tool for breeding, conservation, and genetic improvement in aquatic resources, while oxidative damage will cause a decline in sperm quality during this progress. Melatonin (MT), a natural antioxidant hormone, is used as an additive in sperm cryopreservation to reduce cellular damage from oxidative stress. Here, we aimed to investigate the effect of adding MT to the freezing medium in sperm cryopreservation of brown-marbled grouper (Epinephelus fuscoguttatus). Different concentrations of MT (0, 0.1, 0.25, and 0.5 mg/mL) were tested. We evaluated sperm motility, viability, apoptosis, mitochondrial membrane potential (MMP), and fertilization ability to assess the effects of MT supplementation. Our results demonstrated that the addition of MT to the extender improved the post-thaw motility, MMP, and fertilization ability of brown-marbled grouper sperm. The total motility, curvilinear velocity, straight linear velocity, and average path velocity in MT-treated groups (0.1 and 0.25 mg/mL) exhibited significantly higher values than that of the control group. A higher MMP (p < 0.05) was observed in the group treated with 0.25 mg/mL MT, suggesting that supplementation of MT in the extender might be able to protect mitochondrial membrane integrity effectively. Regarding fertilizing ability, 0.25 mg/mL MT yielded a significantly higher hatching rate than the control. An adverse effect was found with the concentration of MT up to 0.5 mg/mL, suggesting the possible toxicity of a high-dose addition. In this study, we optimized the sperm cryopreservation protocol of brown-marbled grouper, which might be valuable for sperm cryopreservation and sample commercialization of groupers and other fish. Full article

In order to investigate the rational utilization of energy in the fluid jet process, a free dual jet of parallel air is used as a research object. Simulation of turbulence was carried out based on the realizable k-epsilon equations with pressure-velocity coupling, PISO method, discrete method with second-order windward format, and first-order implicit transient solution. The energy separation phenomenon within the jet shear layer and its influencing factors were investigated under dual-jet Reynolds number differences of 12,800, 19,200, 25,600, 32,000, 41,500, and 51,100, respectively. The simulation is in transient format and the jet inlet velocity is given by udf. Calculations show that the pressure perturbation in the air shear layer, which gives rise to the pressure work exchange between the jet and the surroundings, is the main reason for the coexistence of high- and low-temperature regions formed within the jet shear layer, and the larger the Reynolds number, the stronger the energy separation effect. The center streamline path of a parallel air free dual jet can be fitted by a circular arc, whose radius of curvature increases with the Reynolds number, and the curvilinear development path of the dual jet can offset the energy separation effect to some extent. This paper confirms the existence of energy separation in the shear layer of a parallel air free double jet, reveals the mechanism of energy separation in the fluid domain, and explores the flow characteristics of two parallel jets. Full article

Semen preservation involves lengthening sperm’s fertile lifespan without any detrimental effects on its biochemical, functional, and ultrastructural properties. Liquid storage at 4 °C is a ram sperm preservation method. However, this method of storage causes irreversible damage due to cold shocks, osmotic stresses, oxidative stresses, and reductions in sperm metabolism. The present study aims to investigate whether the supplementation of mitochonic acid 5 (MA-5) in a sperm extender could improve chilled ram sperm quality and elucidate its mechanism of action. Ram sperm were diluted with a tris-citrate-glucose extender containing different concentrations of MA-5 (0, 0.1, 1, 10, and 100 nM) and stored at 4 °C for up to 48 h. Sperm motility, membrane integrity, acrosome integrity, mitochondrial membrane potential, reactive oxygen species (ROS) level, ATP content, and the expression of NADPH dehydrogenase subunits 1 (MT-ND1) and NADPH dehydrogenase subunits 6 (MT-ND6) were evaluated. It was observed that compared to the control, the 10 nM MA-5 treatment significantly (p < 0.05) increased total motility (82 ± 3.5% vs. 76 ± 5.9%), progressive motility (67.6 ± 8.2% vs. 51 ± 8.3%), and other parameters (straight-line velocity (VSL), average path velocity (VAP), and curvilinear velocity (VCL)). In addition, 10 nM MA-5 supplementation also improved ram sperm membrane integrity and acrosomal integrity as well increased mitochondrial membrane potential (51.1 ± 0.7% vs. 37.7 ± 1.3%), reduced ROS levels, and elevated adenosine triphosphate (ATP) contents. Furthermore, a Western blot analysis demonstrated that the addition of MA-5 significantly (p < 0.05) increased the expression of MT-ND1 and MT-ND6 proteins in ram sperm, with the 10 nM MA-5 treatment resulting in the highest expression level. These results suggest that MA-5 improves ram sperm quality by maintaining high sperm mitochondrial function during liquid storage at 4 °C. Full article

This study aimed to investigate and compare the vertical Ground Reaction Forces (vGRFs) of patients with Parkinson’s Disease (PwPD) and healthy subjects (HS) when the confounding effect of walking speed was absent. Therefore, eighteen PwPD and eighteen age- and linear walking speed-matched HS were recruited. Using plantar pressure insoles, participants walked along linear and curvilinear paths at self-selected speeds. Interestingly, PwPD exhibited similar walking speed to HS during curvilinear trajectories (p = 0.48) and similar vGRF during both linear and curvilinear paths. In both groups, vGRF at initial contact and terminal stance was higher during linear walking, while vGRF at mid-stance was higher in curvilinear trajectories. Similarly, the time to peak vGRF at each phase showed no significant group differences. The vGRF timing variability was different between the two groups, particularly at terminal stance (p < 0.001). In conclusion, PwPD and HS showed similar modifications in vGRF and a similar reduction in gait speed during curvilinear paths when matched for linear walking speed. This emphasized the importance of considering walking speed when assessing gait dynamics in PwPD. This study also suggests the possibility of the variability of specific temporal measures in differentiating the gait patterns of PwPD versus those of HS, even in the early stages of the disease. Full article