Drivers of megaherbivore demographic fluctuations: inference from elephants

Environmentally induced variation in survival and fecundity generates demographic fluctuations that affect population growth rate. However, a general pattern of the comparative influence of variation in fecundity and juvenile survival on elephant population dynamics has not been investigated at a broad scale. We evaluated the relative importance of conception, gestation, first year survival and subsequent survivorship for controlling demographic variation by exploring the relationship between past environmental conditions determined by integrated normalized difference vegetation index (INDVI) and the shape of age distributions at 17 sites across Africa. We showed that, generally, INDVI during gestation best explained anomalies in age structure. However, in areas with low mean annual rainfall, INDVI during the first year of life was critical. The results challenge Eberhardt's paradigm for population analysis that suggests that populations respond to limited resource availability through a sequential decrease in juvenile survival, reproductive rate and adult survival. Contrastingly, elephants appear to respond first through a reduction in reproductive rate. We conclude that this discrepancy is likely due to the evolutionary significance of extremely large body size – an adaptation that increases survival rate but decreases reproductive potential. Other megaherbivores may respond similarly to resource limitation due to similarities in population dynamics. Knowing how vital rates vary with changing environmental conditions will permit better forecasts of the trajectories of megaherbivore populations.     

The dependence of the growth rate and meat content of young boars on semen parameters and conception rate

Boars have a decisive impact on the progress in pig production, however, there is no recent information about the optimal growth parameters during the rearing period for modern breed later used in artificial insemination (AI) stations. Therefore, the objective of the research was to conduct semen parameter and conception rate analyses on the basis of growth rate and meat content assessments made during the rearing of AI boars of different genotypes. The study was carried out between 2010 and 2014 and included 184 boars in five breed combinations: 46 Polish Large White, 50 Polish Landrace, 27 Pietrain, 36 Duroc×Pietrain and 25 Hampshire×Pietrain. Boars were qualified by daily gains and meat content assessment (between 170 and 210 days of life). A total number of 38 272 ejaculates were examined (semen volume (ml), spermatozoa concentration (×10⁶ ml⁻¹), total number of spermatozoa (×10⁹) and number of insemination doses from one ejaculate (n)). The fertility was determined by the conception rate (%). Semen volume, spermatozoa concentration and conception rate (P<0.01), followed by the total number of spermatozoa and insemination doses (P<0.05) were characterized by the highest variability in relation to breed of boars. The effect of daily gains was reported for spermatozoa concentration, number of insemination doses, conception rate (all P<0.01) and total number of spermatozoa (P<0.05). The peak of growth for spermatozoa concentration, total number of spermatozoa, insemination doses and conception rate was achieved for 800 to 850 g gains. Meat content affected semen volume, number of insemination doses and conception rate (P<0.05). Rearing boars while maintaining daily gains at the 800 to 850 g level and 62.5% to 65% meat content helps AI stations to increase the efficiency and economic profitability, and the number of insemination doses to increase by up to 300 doses/boar within a year. The analyses of growth parameters may help increase the efficiency and economic viability of AI stations.     

输卵管性不孕患者IVF助孕后自然妊娠--附13例临床分析

目的:探讨输卵管性不孕患者进行体外受精-胚胎移植(IVF-ET)后自然妊娠的可能性以及与发生自然妊娠相关的临床条件。方法:对1999年11月至2007年6月于本院生殖中心因输卵管因素不孕进行IVF的患者进行随访,回顾性分析IVF后发生自然妊娠的13例患者的临床特征、IVF助孕情况和自然妊娠情况。结果:13例输卵管因素不孕患者行IVF治疗时的年龄为31.8±4岁(27-41岁),不孕年限5.2±2.2年(2-8年)。行IVF治疗发生生化妊娠1例,流产1例,单胎足月分娩1例。11例患者在IVF后6月内发生自然妊娠,另2例分别在IVF后2年和8年发生自然妊娠。其中,2例有异位妊娠史的患者发生对侧输卵管妊娠,1例发生流产,7例已生育健康后代,3例正处于中孕期。结论:输卵管因素不孕患者行IVF后仍有可能发生自然妊娠,尤其是年轻(<35岁)患者。IVF失败或放弃IVF治疗后患者心理状态的变化,也可能有助于激发其生育潜能,促成自然妊娠的发生。     

关于害虫生态防治若干概念的讨论

讨论有关害虫生态防治策略的若干基本概念,包括产生背景,含义,与综合防治等的关系以及实施等。综合防治遇到的一些问题使得人们寻找新的策略,而生态学,计算机,信息科学及分子生物学的知识与技术的普及则催产了生态防治策略。该策略的要义是强调系统观点和经济生态学原则,运用任何适宜的措施调控害虫种群,不断改善农业生态系统功能,实现环境安全,经济高效,生态协调,持续发展的目标,生态防治的定义与综合防治十分接近,实践中难以区分。生态防治策略及措施具有不同的发展阶段,且随国家和地区的条件不同而变化。与综合防治一样,生态防治的实施需要适宜的社会组织,包含社会组织的统一防治2将有助于生态防治的实施。     

An attack of Ips amitinus (Coleoptera: Curculionidae: Scolytinae) on arboretum in West Siberia: New host of invasive bark beetle among exotic conifers

Invasive populations of small spruce bark beetle Ips amitinus were first registered in 2019 in the southeast of Western Siberia. In natural stands of Siberian pine (Pinus sibirica Du Tour), several hundred hectares of outbreak foci of the alien bark beetle were identified. In 2020, a local focus of the bark beetle was found in the conifer collection in the arboretum “Kedr” of the Institute of Monitoring Climatic and Ecological Systems SB RAS, 30 km from Tomsk. The bark beetle caused the main damage to the collection of pines. I. amitinus colonized both host plants Scotch pine (Pinus sylvestris L.) and mountain pine (Pinus mugo Turra), which were previously known to it in the native range in Europe, and the local Siberian species Siberian pine (Pinus sibirica Du Tour), Siberian spruce (Picea obovata Ledeb.) and introduced Far Eastern Korean pine (Pinus koraiensis Sieb. et Zucc.). Demographic characteristics of I. amitinus studied on damaged trees indicate its high reproduction potential in Siberia. The bark beetle outbreak focus was suppressed; however, this plantation requires further annual monitoring of pest abundance and distribution, both to preserve the scientific dendroecological field station and to study the implementation of sential plant conception in relation to the invasion of I. amitinus.     

爱心饲养对大熊猫心理健康及配种受孕率的影响

大熊猫在人工饲养条件下,单调、狭小的生存空间和伸手即来的食物使大熊猫的生活也变得单调而枯燥,不少饲养大熊猫的单位都存在较严重的种群健康下降问题.     

Parent's expectations and experiences of resemblance through donor conception

In the field of donor conception, matching is a practice that involves choosing gametes or embryos in such a way as to minimize physical differences between the donor and the recipients. This practice serves to create resemblance between child and social parent/s, to meet the societal norm of biological relationship and legitimize the family form.

This study focused on parents’ experiences and expectations of the clinical practice of matching and (non)resemblance with their donor-offspring. Results are based on accounts of 18 heterosexual donor-conceiving parents (11 couples) with a donor-offspring between 8 and 32 years old.

Findings suggest that resemblance is more than just a strategy to achieve social legitimization of the donor-conceived family. Resemblance also plays a role in the creation of family bonds and kinship. This suggests that the social reasoning behind matching should at least be complemented by a psychological understanding of relatedness and connectedness.     

Ethical issues in the diagnostic genetic testing process

The diagnostic genetic testing process has certain unique ethical features and deserves special consideration. The purpose of this study was to determine through empirical research, using focussed interview, what ethical issues are involved in the diagnostic genetic testing process. This article describes views and perceptions of adult patients, parents of child patients and various personnel groups (n = 30). The ethical issues were analysed classified into three main categories: a) personnel characteristics, including personality, professional skills, morals and values; b) realization of ethical principles in the examination process, with subcategories of knowledge, autonomy, data protection and equity; and c) consequences of genetic testing, including patients' control over their own lives, manifestation of heterogeneity and outlook on the world. Problematic ethical issues in all three main categories were described in a more many‐sided way by parents and personnel than by adult patients. In the future, attention should be paid to the content areas highlighted by the study, in both clinical practice and further studies.     

Efficacy of decreasing the dose of GnRH used in a protocol for synchronization of ovulation and timed AI in lactating dairy cows

To determine the efficacy of reducing the dosage of GnRH used in a protocol for synchronization of ovulation and timed AI, primiparous and multiparous lactating Holstein cows (n=237) were randomly assigned to 1 of 2 treatment groups. Ovulation was synchronized for cows in the first group using intramuscular injections of GnRH and PGF₂ as follows: Day 0, 100 μg GnRH; Day 7, 25 mg PGF₂; Day 9, 100 μg GnRH. Ovulation was synchronized in the second group of cows using the same injection schedule and dosage of PGF₂ but only 50 μg GnRH per injection. All cows underwent a timed AI at 12 to 18 h after the second GnRH injection. The proportion of cows ovulating in response to the second GnRH injection (synchronization rate) and pregnancy status at 28 and 56 d post AI were determined using transrectal ultrasonography. The synchronization rate, double-ovulation rate, conception rate at 28 and 56 d post AI, and pregnancy loss from 28 to 56 d post AI did not differ statistically between treatment groups. For all cows, synchronization rate was 84.0%, and double-ovulation rate was 14.1%. Conception rates calculated using all cows receiving synchronization of ovulation were 41.1% at 28 d and 34.4% at 56 d post AI. Conception rates calculated for only synchronized cows were 47.6% at 28 d and 40.1% at 56 d post AI. For all cows, pregnancy loss from 28 to 56 d post AI was 13.5%, with an attrition rate of 0.5% per day. Estimated savings in hormone costs using 50 rather than 100 μg GnRH per injection for synchronizing ovulation were $6.40 per cow and $20.27 per pregnancy. Thus, decreasing the dosage of GnRH used for synchronization of ovulation and timed AI in lactating dairy cows reduces synchronization costs per cow and per pregnancy without compromising the efficacy of the synchronization protocol.     

The Rapan Theory of Conception

People in Rapa, French Polynesia, attempt to limit their families by abstaining from intercourse during the time they think the woman is most likely to conceive. They have little success with this method of contraception, largely because they believe conception occurs during the three or four days immediately following menstruation. This placement of the fertile period is based on a theory of reproduction quite different from that currently prevailing in the West. The Rapan theory is explained, and other societies holding similar ideas concerning the fertile period are indicated.