288 research outputs found
Seasonal variations of sexual activity of local bucks in western Algeria
The aim of the present study was to evaluate the seasonal variation of sexual activity among bucks of local breed (Arbia) in western Algeria. The experiment was carried out using eight bucks aged between 4 and 6 years, a group of males in their pre-puberty age (4 to 6 months) and two females. Animals were kept in a building during one year and fed with a constant ration of wheat and hay with free access to water. Sexual activity was evaluated by scrotal circumference and sexual behaviour analysis. Results showed that the monthly average of scrotal circumference was high during August and September (27.58 ± 0.16 and 27.67 ± 0.17 cm, respectively) and low during April and May (25.18 ± 0.11 and 25.25 ±0.17 cm, respectively). Monthly averages of sexual behaviour followed similar evolution. When the season of the year is considered, sexual behaviour and scrotal circumference presented significant variations. The two parameters are maximal during autumn (7.96 ± 1.28 and 26.89 ± 0.55 cm, respectively) and go down during winter (6.09 ± 1.25 and 25.65 ± 0.27 cm, respectively) to reach minimal values during spring (4.89 ± 1.66 and 25.41 ± 0.37 cm, respectively) then they go up during summer. Inconclusion, bucks of local breed in western Algeria have seasonal variations of sexual activity in relation to annual photoperiod variation; short days stimulate the sexual activity whereas long days inhibit it
Study of seasonal sexual activity variations in Algerian rams: Sexual behaviour, testosterone concentration control and environmental factors
This study focuses on the determination of seasonal effect on two main andrological sexual activity parameters within young and adults rams of Rembi breed from Algeria for a period of one year. The experiment involved a weekly evaluation of males’ sexual behaviour and a monthly measurement of serum testosterone concentration in order to know the main testicular endocrine activity. The purpose of this experiment was to assess better the characteristics of the reproductive activity between two categories of rams age-wise and to define the variations and interactions between the two parameters during each season. Data shows no statistically significant effect of age on the testosterone concentration but showed a highly significant difference between age groups in terms of sexual behaviour. Seasonal variations of the studied parameters were statistically significant in both ram ages with higher values during spring and autumn and lower values during summer and winter.Keywords: Rembi, ram, testosterone, sexual activity, season, age.African Journal of Biotechnology Vol. 12(41), pp. 6042-604
In Vitro Anticoccidial Activity of Olive Pulp (Olea europaea L. var. Chemlal) Extract Against Eimeria Oocysts in Broiler Chickens
Aim: The objective of the present study was to investigate in vitro anticoccidial effect of olive pulp (Olea europaea L var. Chemlal) extract on the destruction of Eimeria spp. oocysts isolated from infected chickens naturally. Materials and methods: The olive pulp (OP) powder was stirred manually in aqueous ethanol in preparation for extraction using the microwave-assisted extraction system. The identification of the phenolic compounds was obtained by ultra-high-performance liquid chromatography–mass spectrometry with electrospray ionisation (HPLC–ESI–MS). The treatment of Eimeria oocyst with OP extract and standard compounds (quercetin and oleuropein) leads to their lysis as shown by the release of substances absorbing at 273 nm. Results: Our results showed that the maximum number of reduced oocysts was recorded after 8 h of incubation of optimum OP extract, quercetin and oleuropein for different periods of time. Also, the number of Eimeria oocysts decreased considerably with increase concentrations after adding the optimum of OP extract in concentration ranging from 0.023 to 0.371 mg/ml. Positive correlation between the optimum OP extract concentrations and the number of Eimeria oocysts reduced was R2 = 0.959. From this in vitro experiment, it can be concluded that the OP extract possesses an anti-Eimeria spp activity. Conclusion: To our knowledge, this is the first time that quercetin and oleuropein were tested to evaluate their anticoccidial activity. The findings of this study showed that phenolic compound of OP extract tested separately possesses anti-Eimeria spp. effect. Further studies should be carried out to test its in vivo efficacy of the OP bioactive compounds in broiler chickens
Sequential use of ammonium and leucine as nitrogen sources during growth of Geotrichum candidum on a glucose based medium
Geotrichum candidum growth on ammonium and leucine as nitrogen
sources and glucose as a carbon source was examined. A clear preference
of G. candidum for ammonium over leucine as a nitrogen source was
shown. Indeed, ammonium was completely exhausted at the end of
exponential growth after less than 35 hrs of culture; in contrast only
5% of leucine was concomitantly assimilated. Growth continued at slower
rates on glucose and leucine as carbon and nitrogen sources
respectively, and at the end of culture (185 hrs), leucine was
completely exhausted
Seasonal variation of plasma testosterone levels in Algerian male Arabia goats
The aim of the present work was to evaluate the general monthly averages of the testosterone hormone and the influence of season and photoperiod on plasma testosterone levels in Arabia bucks of Algeria. Testosterone concentrations were determined throughout one year in blood samples collected every fortnight of the month from nine males of Arabia goat breeds, fed a constant diet, maintained without interactions with female goat. Plasma testosterone level was measured by radioimmunoassay. Analyses performed show that the monthly averages of the testosterone hormone vary during the year; higher levels were recorded during August (T=8.57±6.72, P=0.00***) however, bucks displayed the same change tendency during the same period (P=0.79). Plasma testosterone concentrations vary significantly between seasons (P=0.00***) being higher during autumn (6.15±3.81ng/ml) compared with spring (0.90 ± 1.27ng/ml) when hormone synthesis reaches its lowest levels. In conclusion, Arabia bucks of Algeria displayed a clear seasonality of plasma testosterone concentration with very low levels in winter and spring (from January to May) and high levels in summer and autumn (from July to November).Keywords: Arabia bucks, testosterone, season, photoperiod
Enhancing Hygrothermal Performance in Multi-Zone Constructions through Phase Change Material Integration
\ua9 2024, Tech Science Press. All rights reserved.As buildings evolve to meet the challenges of energy efficiency and indoor comfort, phase change materials (PCM) emerge as a promising solution due to their ability to store and release latent heat. This paper explores the transformative impact of incorporating PCM on the hygrothermal dynamics of multi-zone constructions. The study focuses on analyzing heat transfer, particularly through thermal conduction, in a wall containing PCM. A novel approach was proposed, wherein the studied system (sensitive balance) interacts directly with a latent balance to realistically define the behavior of specific humidity and mass flow rates. In addition, a numerical model implemented in MATLAB software has been developed to investigate the effect of integrating PCM on the hygrothermal balances inside the building. The obtained results indicate a consistent response in internal temperatures, specific humidity, and mass flow rates, with temperature differences ranging from 5\ub0C to 13\ub0C and a maximum phase shift of 13 h. In addition, the findings provided valuable insights into optimizing the design and performance of multi-zone constructions, offering a sustainable pathway for enhancing building resilience and occupant well-being
The Enhanced Adsorption Capacity of <em>Ziziphus jujuba</em> Stones Modified with Ortho-Phosphoric Acid for Organic Dye Removal: A Gaussian Process Regression Approach
\ua9 2024 by the authors. Here, the chemical modification of Ziziphus jujuba stones (ZJS) treated with ortho-phosphoric acid (ZJS-H3PO4) is investigated to enhance its adsorption properties for organic dyes. The physicochemical properties of ZJS-H3PO4 reveal increased porosity (87.29%), slightly higher bulk density (0.034 g mL−1), and enhanced acidity (31.42 m eq g g−1) compared to untreated ZJS. XRF analysis confirms the successful incorporation of orthophosphoric acid during treatment due to a significant increase in phosphorus content. The maximum adsorption capacity of methylene blue on ZJS-H3PO4 is found to be 179.83 mg g−1, demonstrating its efficacy as a potential adsorbent for organic dyes. These findings suggest that modifying ZJS with orthophosphoric acid could be a promising strategy to enhance its adsorption performance in various environmental applications. Furthermore, Gaussian process regression (GPR) is employed to model MB adsorption by ZJS-H3PO4. Optimization of the GPR model involves evaluating different kernel functions and meticulously adjusting parameters to maximize its ability to capture complex relationships in the data. The obtained GPR model demonstrates remarkable performance with high correlation coefficients (R) and low root mean square errors (RMSEs) across all study phases. Model validation is performed through residual analysis, confirming its effectiveness and accuracy in predicting MB adsorption. Finally, a user-friendly interface is developed to facilitate the usage of the GPR model in future applications, representing a significant advancement in environmental process modeling and ecosystem management
Advanced green peel utilization for efficient methylene blue removal: Integrated analysis and predictive modeling
This study explores the adsorption of Methylene Blue (MB) onto Green Peel (GP) material, utilizing advanced analytical techniques and modeling approaches. Fourier-transform infrared spectroscopy (FT-IR) confirms GP\u27s effectiveness as an adsorbent. The study systematically examines the influence of key factors such as adsorbent dose, pH, MB concentration, and temperature on adsorption efficiency. Among the isotherm models analyzed, the monolayer with double energy (M2) model is identified as the most accurate for describing MB adsorption onto GP. Steric parameters provide insights into the adsorption mechanism, revealing temperature-dependent changes. Thermodynamic analysis indicates an exothermic adsorption process, with a decrease in adsorption capacity at elevated temperatures. Density Function Theory (DFT) analysis highlights the potential for electron transfer during adsorption, contributing to a deeper understanding of the process. Molecular Dynamic Simulation (MDS) uncovers stable adsorption configurations and reveals the significance of chemical interactions and Van der Waals forces. Gaussian Process Regression with L\ue9vy Flight Distribution (GPR_LFD) demonstrates exceptional predictive accuracy, closely aligning experimental and predicted MB uptake values. Optimal adsorption conditions (30 minutes contact time, 0.6 g adsorbent dose, 400 mg/L initial MB concentration, pH 6.6, and 10\ub0C) yield an adsorption capacity of 207.90 mg/g. The integration of LFD optimization and GPR prediction through a MATLAB interface further enhances the practical application of these findings. This comprehensive investigation not only advances the understanding of MB adsorption onto GP but also highlights GP\u27s potential as an efficient, reusable adsorbent
The Effect of the Stationary Phase on Resolution in the HPLC-Based Separation of Racemic Mixtures Using Vancomycin as a Chiral Selector: A Case Study with Profen Nonsteroidal Anti-Inflammatory Drugs
\ua9 2023 by the authors.Chiral resolution is a technique of choice, making it possible to obtain asymmetric and enantiomerically pure compounds from a racemic mixture. This study investigated the behavior of vancomycin when used as a chiral additive in high-performance liquid chromatography (HPLC) to separate enantiomers of nonsteroidal anti-inflammatory drugs (NSAIDs), including ketoprofen, ibuprofen, flurbiprofen, and naproxen enantiomeric impurities. We compared two achiral stationary phases (C18 and NH2) to assess the impact of mobile phase composition and stationary phase on the vancomycin retention time in the racemic resolution of drug enantiomers. Our results demonstrated the successful enantioseparation of all drugs using vancomycin in the mobile phase (phosphate buffer 0.05 M/2-propanol, 50/50) with an NH2 column. This enhanced separation on the NH2 column resulted from the chromatography system’s efficiency and vancomycin dimers’ stereoselective interaction on the NH2 surface. This study underscores the importance of stationary phase selection in the chiral resolution of NSAIDs with vancomycin as a chiral additive. It offers valuable insights for future research and development of NSAID chiral separation methods, highlighting potential vancomycin applications in this context
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