Larval and early juvenile development of Lithodes santolla (Molina, 1782) (Decapoda: Anomura: Lithodidae) reared at different temperatures in the laboratory

The southern king crab, Lithodes santolla Molina, is distributed in cold-temperate and subantarctic waters ranging from the southeastern Pacific island of Chiloé (Chile) and the deep Atlantic waters off Uruguay, south to the Beagle Channel (Tierra del Fuego, Argentina/Chile). Recent investigations have shown that its complete larval development from hatching to metamorphosis, comprising three zoeal stages and a megalopa, is fully lecithotrophic, i.e. independent of food. In the present study, larvae were individually reared in the laboratory at seven constant temperatures ranging from 1 to 18 °C, and rates of survival and development through successive larval and early juvenile stages were monitored throughout a period of 1 year. The highest temperature (18 °C) caused complete mortality within 1 week; only a single individual moulted under this condition, 2 days after hatching, to the second zoeal stage, while all other larvae died later in the zoea I stage. At the coldest condition (1 °C), 71% of the larvae reached the zoea III stage, but none of these moulted successfully to a megalopa. A temperature of 3 °C allowed for some survival to the megalopa stage (17-33% in larvae obtained from two different females), but only a single individual passed successfully, 129 days after hatching, through metamorphosis to the first juvenile crab instar. At all other experimental conditions (6, 9, 12 and 15 °C), survival through metamorphosis varied among temperatures and two hatches from 29% to 90% without showing a consistent trend. The time of nonfeeding development from hatching to metamorphosis lasted, on average, from 19 days at 15 °C to 65 days at 6 °C. The relationship between the time of development through individual larval or juvenile stages (D) and temperature (T) was described as a power function (D=aT^b, or log[D]=log[a]blog[T]). The same model was also used to describe the temperature dependence of cumulative periods of development from hatching to later larval or juvenile stages. One year after hatching, the 7th (6 °C) to 9th (15 °C) crab instar was reached. Under natural temperature conditions in the region of origin of our material (Beagle Channel, Argentina), L. santolla should reach metamorphosis in October-December, i.e. ca. 2 months after hatching (taking place in winter and early spring). Within 1 year from hatching, the crabs should grow approximately to juvenile instars VII-VIII. Our results indicate that the early life-history stages of L. santolla tolerate moderate cold stress as well as planktonic food-limitation in winter, implying that this species is well adapted to subantarctic environments with low temperatures and a short seasonal plankton production.     

Rhizogenic Fe–C redox cycling: a hypothetical biogeochemical mechanism that drives crustal weathering in upland soils

Field-scale observations of two upland soils derived from contrasting granite and basalt bedrocks are presented to hypothesize that redox activity of rhizospheres exerts substantial effects on mineral dissolution and colloidal translocation in many upland soils. Rhizospheres are redox-active microsites and in the absence of O₂, oxidation of rhizodeposits can be coupled by reduction of redox-active species such as Fe, a biogenic reduction that leads to Fe translocation and oxidation, accompanied by substantial proton flux. Not only do rhizogenic Fe–C redox cycles demonstrate a process by which the rhizosphere affects an environment well outside the near-root zone, but these redox processes are also hypothesized to be potent weathering systems, such that rhizogenic redox-reactions complement acid- and ligand-promoted reactions as major biogeochemical processes that control crustal weathering. The potential significance of Fe–C redox cycling is underscored by the deep and extensive rooting and mottling of upland subsoils across a wide range of plant communities, lithologies, and soil-moisture and temperature regimes.     

Silent ovulation, based on walking activity and milk progesterone concentrations, in Holstein cows housed in a free-stall barn

The objectives of the current study were to determine the incidence of silent ovulation (based on walking activity and milk progesterone profiles), identify risk factors for silent ovulation, and investigate its impact on reproductive performance in high-yielding dairy cows in free-stall housing. Overall, 277 lactations in 161 Holstein Friesian cows from a commercial dairy herd in northern Japan were studied. Walking activity (measured with pedometers) >80% above the mean for the preceding 2 d was defined as estrus, whereas day of ovulation was estimated using milk progesterone concentrations. Ovulation not preceded by increased walking activity was considered silent ovulation; the incidence was 55.2%, 23.8%, 21.3%, and 10.5% at the first, second, third, and fourth ovulations postpartum, respectively. Moderate and high milk yield significantly increased the risk of silent ovulation at second (odds ratio [OR] = 2.7 and 1.2; P = 0.04) and third and/or fourth ovulations (OR = 6.7 and 12.9; P = 0.03). Based on survival analysis, silent ovulations at the first, second, third, and/or fourth ovulations were associated with 28% (hazard ratio [HR] = 0.72), 55% (HR = 0.45), and 47% (HR = 0.53) reductions in pregnancy rate, respectively, and 41% (HR = 0.59), 66% (HR = 0.34), and 65% (HR = 0.35) reductions in artificial insemination (AI) submission rate. Cows with at least one silent ovulation (with the exception of the first ovulation) had a longer interval from calving to first AI (72 vs. 54 d, P < 0.001) and to achievement of pregnancy (133 vs. 80 d, P < 0.001). In conclusion, approximately one third of the ovulations (based on milk progesterone concentrations) in Holstein cows within 90 d postpartum were silent. Silent ovulations at the second to fourth ovulations were associated with high milk yields and at all ovulations were associated with impaired reproductive performance.     

The developing reproductive 'sink' induces oxidative stress to mediate nitrogen mobilization during monocarpic senescence in wheat

Removal of reproductive 'sink,' i.e., spikelets from wheat, after anthesis delays the rate of flag leaf senescence. Oxidative stress and the oxidative damage to proteins were studied in relation to nitrogen mobilization in wheat plants showing normal and delayed senescence. Wheat plants lacking a reproductive sink showed decreased oxidative stress, lower lipid peroxidation and maintained higher protein, oxidatively damaged proteins, and nitrogen levels as compared to plants with reproductive sink during monocarpic senescence. Oxidative damage to the proteins when not followed by high proteolytic activities led to a slower nitrogen mobilization in wheat plants lacking a reproductive sink. Thus, the influence of the reproductive sink was due to its ability to drive forward the nitrogen mobilization process through high ROS levels which mediated both damage to the proteins and influenced proteolytic activities.     

非人灵长类个体的迁移与扩散

迁移现象在群居动物中普遍存在、在非人灵长类中尤为突出。在非人灵长类中,大多数的迁移表现出强烈的雄性偏向性和雌性不进行迁移的形式。在一些少数的物种中,也存在雌雄双方都进行迁移以及雌性偏向性迁移而雄性不迁移的形式。群居种类、一夫一妻制种类、独居种类的迁移模式上各有特色且不尽相同,这是动物社群结构多样性的体现。驱赶和异性的吸引是推动个体迁移的两大动力,驱赶多发生在一雄多雌的社群中,异性吸引多发生在无亲缘关系的个体之间。个体迁移过程,是个体付出与收益的平衡。迁移不仅是非人灵长类动物生活史中的一个重要环节,同时在不同种群间个体基因交流上也有明显的作用。     

圈养马麝的胆量个性及与麝香分泌和繁殖成效的关系

采用新异物刺激的方式,建立马麝惊扰反应强度指数,通过马麝惊扰后的状态量化其胆量水平,对甘肃兴隆山麝场圈养马麝交配季节和非交配季节胆量(Boldness)进行行为学研究。结合泌香量和产仔量数据,分析胆量对麝香分泌、繁殖成效的效应;同时分析了圈区环境、性别、年龄与马麝胆量之间的关系,以及交配季节与非交配季节间胆量的相关性。结果表明:圈区环境对个体胆量无显著影响(交配季节P = 0.799;非交配季节P =0.152),性别对个体胆量也无显著影响(交配季节P = 0.144;非交配季节P = 0.733),而年龄对个体胆量存在显著影响(交配季节P = 0.012;非交配季节P =0.009),个体年龄越大,胆量越大;交配季节与非交配季节之间胆量呈显著正相关(r =0.592,P < 0.001),但并无明显差异(P =0.095);雄麝泌香量与非交配季节胆量之间存在显著负相关(r = - 0.607,P = 0.016),雌麝繁殖成效与交配季节胆量之间存在显著正相关(r =0.362,P = 0.045)。圈养马麝胆量个性受年龄因素的影响,并在交配季节与非交配季节之间存在一致性,非交配季节胆量更高的雄麝泌香量趋于更少,交配季节胆量更高的雌麝产仔数趋于更多。     

代谢综合征与非酒精性脂肪肝临床特征的关系

目的:探讨代谢综合征(metabolic syndrome,MS)与非酒精性脂肪肝(non-alcoholic fatty liver disease,NAFLD)临床特征之间的相关性。方法:从我院2012年1月-2014年2月健康体检资料中抽选326例经超声确诊为NAFLD的患者,作为NAFLD组,并随机抽选335例无脂肪肝患者作为对照组;观察两组患者间的临床特征,并采用Logistic回归分析MS与NAFLD临床特征之间的相关性。结果:NAFLD组患者体重指数(BMI)、血压、丙氨酸氨基转移酶(ALT)、空腹血糖(FBG)、血尿酸(UA)、高密度脂蛋白(HDL-C)、甘油三酯(TG)、天冬氨酸氨基转移酶(AST)水平显著高于对照组(P0.05):两组间低密度脂蛋白(LDL-C)、总胆固醇(TC)比较无显著性(P0.05)。NAFLD组中MS、血脂及糖代谢异常、肥胖以及高血压的检出率明显高于对照组(P0.05)。经Logistic回归分析显示,NAFLD、BMI、TG、HDL-C、高血压及血糖是MS的独立危险因素。结论:NAFLD患者中存在MS的各种组分聚集特征,MS患病率明显升高,NAFLD是MS的独立危险因素之一,因此MS与NAFLD关系密切。     

半乳糖凝集素-3与程序性死亡受体-1在宫颈鳞癌组织中的表达及其临床意义

目的:探讨半乳糖凝集素-3(Gal-3)和程序性死亡受体-1(PD-1)在宫颈鳞癌组织中的表达及其临床意义。方法:选择2016年1月-2017年12月期间我院收治的宫颈鳞癌患者80例纳入观察组,宫颈上皮内瘤变(CIN)患者60例纳入CIN组,取同期在我院进行治疗的宫颈炎患者50例纳入对照组。采集三组患者的宫颈组织标本,采用免疫组化SP法对各组织标本中的Gal-3、PD-1的阳性率、表达水平进行检测,并分析Gal-3、PD-1与宫颈鳞癌临床病理特征的关系以及各指标表达水平的相关性。结果:观察组、CIN组的Gal-3、PD-1的阳性表达率、表达水平均高于对照组,且观察组高于CIN组(P0.05)。Gal-3、PD-1的表达与宫颈鳞癌患者的年龄、病灶大小、分化程度无关(P0.05),而与宫颈鳞癌肿瘤的分期、淋巴结转移有关(P0.05)。经Spearman相关性分析显示,宫颈鳞癌组织中Gal-3与PD-1间表达水平呈正相关性(r=0.496,P=0.000)。结论:Gal-3、PD-1的表达水平与宫颈鳞癌的发生、发展有密切关联,并且两种指标间呈明显正相关。     

麋鹿繁殖行为和粪样激素水平变化的关系

１９９７年７－９月和１９９８年３－７月间,在江苏大麋鹿保护区共观察到麋鹿的２７种繁殖行为,雄鹿有１７种,雌鹿有１０种,在１９９８年３－７月间,利用放射免疫分析法（ＲＩＡ）测定了鹿麋样中的性激素水平,包括雄鹿的睾酮,雌鹿的酮,雌鹿的孕酮、雌二醇和雌三醇。实验结果表明：１许多繁殖行为的发生频次和持续时间表现出明显的季节变化（Ｐ〈０．０５）,如雄鹿的求偶行为、标记行为和性行为及雌鹿的性行为等在发情期有一     

血清肿瘤标志物与宫颈癌病理特征的关系及对术后复发的预测研究

摘要 目的：探讨血清肿瘤标志物与宫颈癌病理特征的关系及对术后复发的预测研究。方法：选择2015年1月至2017年12月来我院诊治的宫颈癌患者82例作为观察组,选择同期来我院体检的健康女性者50例,两组均使用电化学发光免疫分析法检测血清中的CA125、CA153、CA199、CEA水平,观察组患者随访时间截至2022年12月。对比两组血清CA125、CA153、CA199、CEA水平,分析观察组患者血清CA125、CA153、CA199、CEA水平与临床病理特征的关系,分析观察组患者术后随访复发情况,宫颈癌根治术后患者复发的单因素与多因素Cox回归结果,血清CA125、CA153、CA199、CEA水平对宫颈癌根治术后复发的预测价值。结果：观察组的血清CA125、CA153、CA199、CEA水平明显较对照组高（P<0.05）。宫颈癌患者不同FIGO分期、间质浸润深度及是否存在淋巴结转移间血清CA125、CA153、CA199、CEA水平对比有统计学意义（P<0.05）。82例患者随访时间为13~60个月,中位生存时间为39个月,截止2022年12月末次随访,82例患者术后复发18例（21.95%）。单因素及多因素Cox回归分析表明,FIGO分期在ⅡA期、间质浸润深度≥1/2、有淋巴结转移、CA125≥307.41 U/mL、CA153≥185.89 U/mL、CA199≥153.23 U/mL、CEA≥30.15 ng/mL是影响宫颈癌术后复发的独立危险因素。ROC曲线显示,CA125+CA153+CA199+CEA预测宫颈癌术后复发的AUC明显较CA125、CA153、CA199、CEA单独指标预测价值高（P<0.05）。结论：宫颈癌患者血清CA125、CA153、CA199、CEA高表达,其与间质浸润深度、FIGO 分期、淋巴结转移、术后复发有关,四者联合可作为宫颈癌术后复发的预测指标。