饲粮中主要谷物与谷物颗粒大小对早期罗曼褐壳蛋鸡生产性能和蛋品质的影响

试验旨在研究饲粮中主要谷物和谷物的几何平均粒径（GMD）对20～48周龄罗曼褐壳蛋鸡生产性能与蛋品质的影响。试验选择960只罗曼褐壳蛋鸡,采用完全随机设计为6×2×3,共分6个处理组．谷物饲粮分别为玉米和小麦,谷物粉碎粒度分别为6、8、10mm。每个处理设8个重复,每个重复20只。所有的饲粮配方设计中包含50％的玉米或小麦。每4周记录生产性能结果,第48周龄时测量蛋品质。试验结果表明,GMD为10mm时鸡采食量显著高于GMD为6和8mm时（P〈0.05）,说明粗糙的谷物粉碎粒度一定程度上有助于提高蛋鸡的采食量,而对蛋品质参数均没有显著影响。可以得出结论,谷物类型与谷物GMD除了影响早期罗曼褐壳蛋鸡采食量随谷物粉碎粒度的增加而增加外,其生产性能和蛋品质指标变化均不显著。     

Competitive Removal of Heavy Metals from Aqueous Solutions by Montmorillonitic and Calcareous Clays

A batch sorption method was used to study the removal of few toxic metals onto the Late Cretaceous clays of Aleg formation (Coniacian–Lower Campanian system), Tunisia, in single, binary and multi-component systems. The collected clay samples were used as adsorbents for the removal of Pb(II), Cd(II), Cu(II) and Zn(II) from aqueous solutions. Results show that the natural clay samples were mainly composed of silica, alumina, iron and magnesium oxides. N₂-adsorption measurements indicated mesoporous materials with modest specific surface area of <71 m²/g. Carbonate minerals were the most influencing parameters for heavy metal removal by natural clays in both single and multi-element systems. The affinity sequence was Pb(II)>Cu(II)>Zn(II)>Cd(II) due to the variable physical properties of the studied metals. The maximum adsorption capacity reached 131.58 mg/g in single systems, but decreased to <50.10 mg/g in mixed systems. In single, binary and muti-element systems, the studied clay samples removed substantial amounts of heavy metals, showing better effectiveness than the relevant previous studies. These results suggest that the studied clay samples of the Late Cretaceous clays from Tunisia can be effectively used as natural adsorbents for the removal of toxic heavy metals in aqueous systems.     

Seasonal Variations in Proximate and Fatty Acid Composition of Viscera of Sardinella aurita,Sarpa salpa,and Sepia officinalis from Tunisia

Seasonal variations of the proximate composition and fatty acid profiles in viscera from Sardinella aurita, Sarpa salpa, and Sepia officinalis were studied. Significant seasonal variations were observed in the amounts of moisture, lipid, protein, and ash between species. Viscera protein content undergoes large fluctuations. This tendency is different from results observed for the edible parts or for the whole body of many marine species. Ash content also showed significant differences. Lipid contents varied with seasons, in a proportionally inverse manner to water contents. Fatty acid composition showed significant differences from October to December. Interestingly, the highest total omega-3 contents were comparable to many commercial marine fish oils.     

巴基斯坦波特瓦尔高原土壤侵蚀调查报告

[目的]开展巴基斯坦的土壤侵蚀调查与典型单元的定量评价研究,旨在为巴基斯坦土壤侵蚀防治和了解泛第三极生态环境现状提供科学依据。[方法]在巴基斯坦北部的波特瓦尔高原,沿着穆里—伊斯兰堡—拉瓦尔品第—古杰尔汗—杰格瓦尔—保恩路线,选择了15个调查单元(12个小流域,3个矩形区),于2019年4月16—20日,对调查单元内的土壤侵蚀类型与特征、土地利用类型和水土保持措施等进行了调查。[结果]波特瓦尔高原的林地、草地整体土壤侵蚀较轻,以片蚀为主;土壤侵蚀主要发生在建设用地,开挖边坡、排土边坡、土路边坡和砖厂平台等人为形成的边坡和裸露平台在降雨和径流的作用下产生沟蚀;部分自然山坡因过度放牧,发生重力侵蚀和沟蚀。15个调查单元的平均土壤侵蚀速率平均值介于51.40～1 338.91 t/(km~2·a)之间。[结论]波特瓦尔高原的土壤侵蚀主要发生在建设用地,应对生产建设项目引起的土壤侵蚀进行监督治理,同时通过试验开发匹配的土壤侵蚀防治措施;北部穆里地区是巴基斯坦重要的水源涵养地,需要对该地区大量的建设项目进行合理的规划与审批,防止土壤侵蚀加剧,引起水质和生态环境恶化;应加强沟壑区溯源侵蚀的研究与防控,以保护农田,确保粮食安全;需加强对该区土壤侵蚀基础数据的采集,并对不同尺度的土壤侵蚀发生机理与过程进行研究,切实保障巴基斯坦土地资源。     

Alteration of chemical composition and the oxidative stability of bleached pomace-olive oil on activated clays

This work is a contribution to the study of the bleaching process, which is a very important stage in the refining process of vegetable oils and used to reduce or convert undesired constituents to harmless ones from fats and oils. The virgin olive oil, taken as reference, and the pomace-olive oil were bleached in the optimal conditions using Tunisian bleaching earths (South of Tunisia) which were activated in our laboratory and compared with commercial clays. It was shown that activated Tunisian clays are characterized by a very important adsorptive capacity, comparable to that of commercial clays. Also, the physicochemical stability of bleached oils was studied. The fatty acid composition (GC), the triacylglycerol composition (HPLC), and the oxidative stability (UV spectrometry) allowed us to conclude that oils, bleached with the Tunisian activated clays, do not undergo considerable physicochemical alterations and remain corresponding to the international standards for refined oils for human consumption.     

The study of developmental capacity of vitrified mouse blastocysts in different straws after transfer to mouse pseudo pregnant

Vitrification is the commonly used method for long-term storage of pre-implantation mammalian embryos. It is an essential part of assisted reproductive technologies. The re-expansion rate, pregnancy and birth rate of vitrified blastocysts using CPS were compared with OPS and Conventional Straw. Female NMRI mice were injected with Gonadotrophins in order induce them for super ovulation. At that time the mice were sacrified by cervical dislocation and dissected of mouse abdomen. The uterine horns were existed blastocysts were collected in PBS and randomly allocated to four groups: vitrification in CPS, conventional straw, OPS and untreated controls. The vitrification solution was EFS40%. After storage for 1 month in liquid nitrogen, the blastocysts were thawed in 0.5 M sucrose for in vitro culture in M16 medium. After 6 h of culture, the numbers of expanded blastocysts was recorded and ready for transfer to uterus of pseudo pregnant mouse. The re-expansion rate of the CPS group (72.1%) was significantly higher (p < 0.05) than OPS (52.55) and C.S. (38.6%) groups. The pregnancy (70%) and birth rate (45%) of blastocysts in CPS were similar to those of fresh blastocysts (80% and 45.5%) and the pregnancy (10%) and birth rate (5.1%) in Conventional Straws lower than OPS (20 and 7.5%), but were not significantly different. Mouse blastocysts vitrified using CPS had a better result compared with OPS and Conventional Straw. The value of CPS for vitrification of blastocysts may also merit investigation.     

Comparative effectiveness of different infiltration models in estimation of watershed flood hydrograph

The present study aims to evaluate performance of different infiltration models, namely initial and constant rate, soil conservation service (SCS) curve number and Green–Ampt in simulation of flood hydrographs for the small-sized Amameh Watershed, Iran. To achieve the study purpose, the infiltration rates were measured using rainfall simulator in work units acquired through overlaying topography, land use, drainage network and soil hydrologic group maps. All parameters of the study infiltration models were determined with the help of the Infilt. software package. The performances of the models in simulation of the observed output hydrographs from the entire watershed were ultimately evaluated for 28 rainfall–runoff events in the HEC-HMS environment. The different components of the observed and estimated hydrographs including time to peak, runoff volume, peak discharge, discharge values and peak time deviation were compared using relative error (RE), coefficient of determination (R²), peak-weighted root mean square error (PWRMSE) and Nash–Sutcliffe (NS) criteria. The general performance of estimations was also qualitatively assessed using scatter plot and distribution of study variables around standard lines of 1:1 slope. The results revealed that the SCS infiltration model with PWRMSE = 0.61 m³ s^?1 and NS = 0.53 performed better than initial and constant rate model with PWRMSE = 1.1 m³ s^?1 and NS = 0.54, and Green Ampt model with PWRMSE = 1.35 m³ s^?1 and NS = 0.29 in estimation of flood hydrograph for the Amameh Watershed.