Effect of fast-, medium- and slow-growing strains on meat quality of chickens reared under the organic farming method

The characteristics of meat quality, chemical and fatty acid composition, from fast-growing (FG) and medium-growing (MG) meat-type and slow-growing (SG) egg-type chickens reared under organic conditions were compared. Three-hundred and sixty 1-day-old male chicks, equally divided into three experimental groups represented by strains (FG: Cobb 700, MG: Naked neck Kabir and SG: Brown Classic Lohman) were housed into three poultry houses with outdoor pasture availability of 10 m(2)/bird located in the same Research Centre of the University of Perugia. All the birds were fed ad libitum the same diets formulated according to the European Union (EU) Regulations by using organic raw materials. Birds from the FG and MG groups were raised until 81 days, whereas birds from the SG group were raised until 96 days in order to achieve an acceptable market live weight. SG birds showed significantly (P < 0.01) higher breast meat drip and cook losses, Allo-Kramer shear values and collagen content. In comparison with FG and SG, MG exhibited a higher breast meat pH (5.86% v. 5.79% and 5.78%, respectively; P < 0.01) and a lower lightness (54.88% v. 57.81% and 56.98%, respectively; P < 0.05). Genotype dramatically affected the lipid content as well as the fatty acid composition of both breast and thigh meat. SG exhibited the lowest content of lipid, both in breast and in thigh meat, the lowest proportions of monounsaturated fatty acids (MUFA) and the highest proportions of polyunsaturated fatty acids (PUFA). The total n-3 PUFA of SG breast meat was double that of FG meat and intermediate with respect to MG birds (8.07% v. 4.07% v. 5.14% total fatty acids; P < 0.01). The fatty acid composition of thigh meat is similar to that of breast meat, but the differences among genotypes are less pronounced. Total saturated fatty acids were not affected by the genotype. In conclusion, meat functional properties of FG and MG strains appeared much more attractive both for industry and consumer (lower drip and cook losses and higher tenderness), whereas from a nutritional point of view, meat from SG appeared healthier (less fat and higher content of n-3 PUFA) and thus might better fit with the consumer's expectations of organic products.     

Conformational Changes and Ligand Recognition of Escherichia colid-Xylose Binding Protein Revealed

ATP binding cassette transport systems account for most import of necessary nutrients in bacteria. The periplasmic binding component (or an equivalent membrane-anchored protein) is critical to recognizing cognate ligand and directing it to the appropriate membrane permease. Here we report the X-ray structures of d-xylose binding protein from Escherichia coli in ligand-free open form, ligand-bound open form, and ligand-bound closed form at 2.15 Å, 2.2 Å, and 2.2 Å resolutions, respectively. The ligand-bound open form is the first such structure to be reported at high resolution; the combination of the three different forms from the same protein furthermore gives unprecedented details concerning the conformational changes involved in binding protein function. As is typical of the structural family, the protein has two similar globular domains, which are connected by a three-stranded hinge region. The open liganded structure shows that xylose binds first to the C-terminal domain, with only very small conformational changes resulting. After a 34° closing motion, additional interactions are formed with the N-terminal domain; changes in this domain are larger and serve to make the structure more ordered near the ligand. An analysis of the interactions suggests why xylose is the preferred ligand. Furthermore, a comparison with the most closely related proteins in the structural family shows that the conformational changes are distinct in each type of binding protein, which may have implications for how the individual proteins act in concert with their respective membrane permeases.     

宽恕与睡眠质量关系的研究进展

近年来,国内外对宽恕的研究逐渐增多,但宽恕与睡眠质量关系的研究较少,本文通过综述现有的一些研究资料,分析二者之间的关系。分析表明,人际侵犯事件是影响宽恕的外部因素,其严重程度直接影响受害者的宽恕水平及睡眠质量;宽恕能够降低受害者的生理唤醒、情绪唤醒、及认知唤醒,从而改善睡眠质量,但之间的相互作用及具体的内在影响机制并不明确。同时,影响宽恕水平的宜人性、外倾等人格特质也会影响睡眠质量。最后分析了目前研究中存在的缺陷,并对宽恕与睡眠质量关系的研究前景进行了展望。     

Changes in diatom-dominated biofilms during simulated improvements in water quality: implications for diatom-based monitoring in rivers

Although benthic diatoms are used to assess river water quality, there are few data on the rate at which diatom assemblages react to changes in water quality. The aim of this study was to assess the reaction time of diatoms and to discuss the changes occurring during water quality improvement on the basis of their autecological characteristics. In order to simulate this improvement, diatom-dominated biofilms grown on artificial sandstone substrata were transferred from several polluted rivers to an unpolluted river. They were sampled three times: before transfer and 1 and 2 months after transfer. The ecology and growth-forms of the taxa explained most of the changes in species composition observed during the experiment. Adnate diatoms gradually replaced motile and stalked taxa. Gomphonema parvulum, a stalked diatom positioned vertically in the biofilm, is adapted for light and space competition in high-density algal biofilms. When transferred to an unpolluted site, this growth-form is less competitive and does not tolerate the high grazing pressure. Fistulifera saprophila is a single celled motile diatom, living in organic matrices. When the artificial substrata were transferred to the unpolluted site, this particular ecological niche disappeared quickly. On the other hand, Achnanthidium minutissimum, which is considered to be cosmopolitan and an early colonizer, increased during the first month of transfer and then decreased. It was gradually replaced by A. biasolettianum, which was the taxon best suited to this pristine stream. The changes observed differed between treatments depending on the species composition and architecture of the biofilms. In particular, biofilms dominated by stalked and motile diatoms were more quickly modified than those dominated by small motile diatoms. The diatom index reflects these changes, and its values showed that about 60 days following a water quality improvement were necessary for transferred diatom assemblages to reach diatom index values similar as those at the unpolluted river.     

复合菌剂M5对红螯螯虾(Cherax quadricarinatus)高密度养殖系统水质及其肠道微生物群落影响的初步研究

应用自制复合菌剂M5于红螯螯虾(Cherax quadricarinatus)的高密度养殖系统中,通过分析肠道菌群并监测养殖水质,研究了复合菌剂作用的效果及潜在的机理。结果显示,复合菌剂M5的使用可显著降低养殖水环境的pH值,降低污染物NH⁺₄、NO^-₂和COD的浓度,抑制弧菌属（Vibrio）中某些条件致病菌的生长。基于PICRUSt与KEGG数据库的功能预测及肠道菌群的群落分析,复合菌剂既可作为额外的营养补充物,缓解肠道群落之间对营养源的竞争,又可提高虾的消化能力、免疫力。新型复合菌剂M5可显著改善养殖水质并影响肠道菌群的组成与功能,从而提高养殖存活率。     

基于MuSIASEM理论的大连经济技术开发区可持续发展评价

基于社会生态系统代谢多尺度综合评估（MuSIASEM）理论,对2000-2007年大连经济技术开发区人类活动时间、体外能投入量和增加值进行综合评价.结果表明：2000-2007年,大连开发区居民生活水平逐年提高;农业逐渐萎缩;第二产业仍为区域支柱产业,能耗较大;第三产业发展落后于第二产业;区域整体和各个产业的体外能代谢率明显提高,能源密度不断下降;人类活动时间与体外能投入量不断减少的情况下,经济增加值稳步增长,区域整体发展呈可持续态势.     

新疆罗布麻生态类型及其纤维品质研究

新疆塔里木河及叶尔羌河流域是我国能够提供商品精干罗布麻的主要地区。由于野生罗布麻生长高矮不一,形态各异,与其纤维品质的相关性较大。通过40个株号的罗布麻植株形态和纤维长度等的的测定,分析各类型罗布麻的纤维长度和罗布麻植株各部分纤维长度情况。研究结果表明：罗布红麻高杆类型主茎纤维最长,罗布麻放牧类型纤维最短。罗布麻植株各部分纤维长度是主茎上的大于分枝,主茎中部的最长,基部和梢部最短。为野生罗布麻资源开发利用提科学依据。     

瑞芬太尼靶控输注对宫颈癌根治术患者麻醉苏醒质量、应激反应及Th1/Th2免疫平衡的影响

摘要 目的：观察瑞芬太尼靶控输注对宫颈癌根治术患者麻醉苏醒质量、应激反应及辅助T细胞（Th）1/Th2免疫平衡的影响。方法：按照随机数字表法将2023年1月到2023年6月期间我院接受的120例宫颈癌根治术患者分为舒芬太尼组（n=60,舒芬太尼麻醉）和瑞芬太尼组（n=60,瑞芬太尼麻醉）。对比两组的麻醉苏醒质量、应激反应指标[皮质醇（Cor）、去甲肾上腺素（NE）、血管紧张素1（Ang-1）、血管紧张素2（Ang-2）]、Th1/Th2免疫平衡指标[包括Th1、Th2及调节性T细胞（Treg）、Th1/Th2比值],术后记录不良反应发生情况。结果：与舒芬太尼组相比,瑞芬太尼组的应激呼吸恢复时间、睁眼时间、拔管时间更短（P<0.05）。术后1 d,两组Cor、NE、Ang-1、Ang-2升高,但瑞芬太尼组低于舒芬太尼组（P<0.05）。术后1 d,两组Th1、Treg、Th1/Th2升高,但瑞芬太尼组低于舒芬太尼组;Th2下降,但瑞芬太尼组高于舒芬太尼组（P<0.05）。两组不良反应发生率组间对比未见差异（P>0.05）。结论：瑞芬太尼靶控输注用于宫颈癌根治术患者,可改善麻醉苏醒质量,减轻应激反应,调节Th1/Th2免疫平衡,且不增加不良反应的发生率,效果较好。     

Sperm quality, secondary sexual characters and parasitism in roach (Rutilus rutilus L.)

According to sperm competition models, a male spawning in a disfavoured role should have spermatozoa with higher velocity but shorter longevity compared with a male spawning in a favoured role. Moreover, immunosuppressive androgens are needed to produce both secondary sexual characters and sperm cells. The 'sperm protection' hypothesis suggests that the immunosuppressive action of androgens has evolved to protect haploid spermatozoa, which are antigenic, from autoimmune attacks. Therefore, a male with high sexual ornamentation may be more susceptible to diseases but may possess better quality ejaculate than his less ornamented rival. We studied sexual ornamentation (breeding tubercles), ejaculation quality (sperm concentration, longevity and spermatozoal velocity) and intensity of parasitism in the cyprinid, Rutilus rutilus . Sperm longevity and spermatozoal velocity were positively correlated. Males having elaborated sexual ornamentation had longer-lived sperm and more Myxobolus mülleri parasites in the liver compared with males with low ornamentation. However, no difference was found between males with different degrees of ornamentation with respect to sperm concentration, spermatozoal velocity or other parasites. Since the highly ornamented males had higher sperm longevity, the present results are partly consistent with the predictions of the sperm competition models and the 'sperm protection' hypothesis.  © 2004 The Linnean Society of London, Biological Journal of the Linnean Society , 2004, 81 , 111–117.     

Rapid pre-screening of cervical smears as a method of internal quality control in a cervical screening programme

Objective:  To evaluate the performance of rapid pre-screening (RPS) as a method of internal quality control in the cytopathological examination of cervical smears for cervical cancer screening.
Methods:  The sample consisted of 6135 cervical smears submitted to RPS and routine screening (RS) methods. The smears classified as negative in RPS and RS were considered final diagnoses, and were not, therefore, submitted to any additional review. The smears identified as suspect or unsatisfactory according to RPS were analysed separately by two different cytologists irrespective of the diagnosis reached in RS. Smears considered abnormal or unsatisfactory at RS were also reviewed. When both cytologists issued concordant diagnoses, this was considered the final diagnosis. Discordant results were analysed by a third cytologist and a consensus meeting was held to define the final diagnosis.
Results:  Taking abnormalities detected by RS as the denominator, RPS had a sensitivity of 63.0% for the detection of all abnormal smears and 96.7% for high grade squamous intraepithelial lesion (HSIL). When compared with the final diagnosis, sensitivity of RPS for all abnormal smears was 74.9% and for HSIL 95.0%. Of the 529 abnormal smears confirmed in the final diagnosis, 2.15% were detected only by the RPS.
Conclusion:  RPS is an effective alternative method of internal quality control with high sensitivity for the detection of more severe lesions. It also permits monitoring of the laboratory rate of false-negative results, and allows constant evaluation of the performance both of the pre-screening and RS cytologists.