Segregation in the African wintering ranges of English and Swiss Swallow Hirundo rustica populations: a stable isotope study

Capsule Stable isotope analysis of Swallow feathers, grown in Africa, revealed significant differences between populations breeding in Switzerland and England.

Aims To investigate the extent to which Swallow populations breeding in Switzerland and England are separated on their African wintering grounds.

Methods Swallows were caught at breeding colonies, biometric measurements were taken and feathers, grown in Africa, were collected. Feathers were combusted in a Carlo Erba C/N/S analyser and the δ¹³C and δ¹⁵N signatures were measured using a mass spectrometer.

Results The δ¹³C signatures of Swiss birds were significantly more depleted than those of birds from England. The δ¹⁵N signatures did not differ between the two populations.

Conclusion Birds from Switzerland and England probably winter in geographically distinct parts of Africa. The Swiss birds probably feed on prey that are more reliant on C₃ vegetation, from woodlands, than the prey of English birds, which are more reliant on C₄ vegetation, from grasslands.     

Effect of Birth Season on Circadian Typology Appearing in Japanese Young Children Aged 2 to 12 Years Disappears in Older Students Aged 18 to 25 Years

Several studies suggest that season of birth differentially affects the physiological characteristics of humans. Those living at relatively high latitude, such as Canada, Spain, and Italy (44°N–45°N), and born in the fall tended to be “morning-type” persons in comparison to those born in other seasons. There are relatively little data on the affect of season of birth on people residing at low latitude. Here the authors show that at low latitude, Kochi, Japan (33°N), the effect of season of birth on the morningness chronotype is confined to young children aged 1–12 yrs, disappearing in elderly persons. Only female participants aged 2–12 yrs born in the fall, especially in November, were significantly morning-typed (p < .001) in comparison to those born in the other seasons, whereas there were no such significant season-of-birth differences in morningness-eveningness preference among male participants. Moreover, both female and male participants aged 13–25 yrs showed no significant seasonal differences in morningness-eveningness preference. The small effects detected in this study might be due to smaller seasonal change in day length at the relatively lower latitude of Kochi. (Author correspondence: haratets@kochi-u.ac.jp)     

Bipolar Disorder with Seasonal Pattern: Clinical Characteristics and Gender Influences

Bipolar disorder (BD) has a multifactorial etiology with heterogeneous clinical presentations. Around 25% of BD patients may present with a depressive seasonal pattern (SP). However, there are limited scientific data on the prevalence of SP, its clinical manifestations, and any gender influence. Four hundred and fifty-two BD I and II cases (62% female), recruited from three French university-affiliated psychiatric departments, were assessed for SP. Clinical, treatment, and sociodemographic variables were obtained from structured interviews. One hundred and two (23%) cases met DSM-IV (Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition) criteria for SP, with similar frequency according to gender. Multivariate analysis showed a significant association between SP and BD II (odds ratio [OR]?=?1.99, p?=?0.01), lifetime history of rapid cycling (OR?=?2.05, p?=?0.02), eating disorders (OR?=?2.94, p?=?0.003), and total number of depressive episodes (OR?=?1.13, p?=?0.002). Seventy-one percent of cases were correctly classified by this analysis. However, when stratifying the analyses by gender, SP was associated with BD II subtype (OR?=?2.89, p?=?0.017) and total number of depressive episodes (OR?=?1.21, p?=?0.0018) in males but with rapid cycling (OR?=?3.02, p?=?0.0027) and eating disorders (OR?=?2.60, p?=?0.016) in females. This is the first study to identify different associations between SP and clinical characteristics of BD according to gender. The authors suggest that SP represents a potentially important specifier of BD. These findings indicate that seasonality may reflect increased severity or complexity of disorder.     

Post-parturial reproduction in terrestrial isopods: a partial review

This review deals with some aspects of terrestrial isopod reproduction including breeding season, breeding periods, patterns and strategies, parturition, number and size of broods and mancae. Reproductive period is described by the exact dates (i.e. season) marsupial females were collected in the field, and the duration of the breeding period. The information for both aspects was generally obtained through field work by observing marsupial females. Two reproductive patterns are used by terrestrial isopods, either a discrete (i.e. seasonal) or a continuous (i.e. non-seasonal) pattern. The discrete pattern can be either annual when females breed once a year, or they can breed biannually or multi-annually (two or more times during the year). This conclusion is based generally on observing marsupial females in the field. Therefore, this information does not apply to the reproductive pattern of the individual female since a female may use either or both patterns, i.e. seasonal and continuous. Only by raising individual females singly (with a male) can this point be clarified. This way, the breeding strategy of the same individual female can be studied. The subject is discussed and reviewed based on my research data.     

川西亚高山不同海拔森林土壤活性氮库及净氮矿化的季节动态

研究了川西理县毕棚沟不同海拔梯度(3600 m、3300 m和3000 m)森林群落土壤活性氮库及土壤净氮矿化速率的季节动态.结果表明: 研究区森林土壤活性氮库(铵态氮、硝态氮、微生物生物量氮和可溶性有机氮)及净氮矿化速率存在明显的季节变化,但不同形态土壤活性氮库的季节动态有一定差异.4个采样时期(非生长季与生长季初期、中期及末期)各海拔土壤硝态氮浓度(8.38～89.60 mg·kg^-1)均显著高于铵态氮浓度(0.44～8.43 mg·kg^-1).生长季初期各海拔梯度的土壤净氮矿化速率均表现为负值(-0.77～-0.56 mg·kg^-1·d^-1),而非生长季、生长季中期和末期均为正值.除硝态氮外,不同海拔的土壤铵态氮、微生物生物量氮和可溶性有机氮浓度的差异极显著,海拔对它们的影响与季节变化有关.该区土壤净氮矿化以硝化为主,且氮矿化过程不受海拔梯度的影响.冬季土壤净氮矿化明显(0.42～099 mg·kg^-1·d^-1),早春高的土壤无机氮可能为植物生长提供基础养分,也可能通过淋溶方式从系统中丢失.     

性别、季节和体型大小对吐鲁番沙虎巢域的影响

2008年6月份至2009年5月份对吐鲁番沙虎的巢域进行调查:2008年6月份至2008年8月份为繁殖季节(RS),2008年9月份至2009年5月份(冬眠期除外)为非繁殖季节(NRS)。利用截趾标志重捕法研究吐鲁番沙虎的巢域,共标记283只吐鲁番沙虎,累计繁殖季节24只,非繁殖季节43只重捕超过3次(其中13只个体在繁殖季节和非繁殖季节均够3次以上捕捉次数,为重复个体),可以用于计算个体巢域面积数据。利用软件MapGis计算最小凸多边形法(MCP)巢域面积,并分析性别、体型大小、季节等因素对巢域的影响。结果表明:吐鲁番沙虎非繁殖季节雄性、雌性与幼体各组间的巢域面积差异均显著,繁殖季节巢域面积差异不显著;雌雄个体不同季节或全年合并比较巢域面积差异性均不显著;非繁殖季节面积与吻肛长(SVL)显著相关、全年成体组的巢域面积与吻肛长显著相关;成体巢域面积季节差异显著(U=41,P=0.046),幼体则没有季节差异(U=159,P=0.537)。因而,吐鲁番沙虎的巢域大小受性别因素影响不大,体型大小对巢域面积有显著影响,由于繁殖、食物资源等的季节变化是影响吐鲁番沙虎巢域最重要的因素。     

东海竹筴鱼的食性

以2008年5月、8月、11月和2009年2月东海灯光围网采集到的453条东海竹筴鱼为研究对象,对其胃含物进行分析,应用K-W非参数检验、卡方检验、聚类分析等方法,对不同季节和发育阶段条件下东海竹筴鱼的食性进行研究.结果表明: 东海竹筴鱼的饵料生物有124种(包括未鉴定种),浮游甲壳类和小型鱼类为其主要饵料类群.优势饵料生物依次是麦氏犀鳕(IRI%=39.2%)、长尾类糠虾幼体(IRI%=18.4%)、短尾类大眼幼体(IRI%=7.6%)和太平洋磷虾(IRI%=6.6%)等.季节和叉长对东海竹筴鱼的摄食强度均有显著影响(P<0.01),东海竹筴鱼春季摄食强度最高,而冬季最低;叉长140～159 mm的竹筴鱼摄食强度最高,叉长45~99 mm的幼鱼的摄食强度较高,其余叉长的鱼摄食强度相对较低.聚类分析结果表明,叉长100 mm是东海竹筴鱼摄食取向的拐点.东海竹筴鱼四季的平均营养级为3.51,属于低级肉食性鱼类.     

Influence of housing and season on pubertal development,boar taint compounds and skin lesions of male pigs

Rearing entire pigs may lead to meat quality and welfare problems in relation to pubertal development. A better knowledge of the sources of variation of pubertal development, behaviour and boar taint is needed before generalizing entire male pigs. From 84 days of age, entire male pigs were reared in groups of 10 either in a conventional (C, 1 m²/animal, slatted floor) or an enriched (E, 2.5 m²/animal, straw bedding, outdoor run) housing during spring or autumn and fed ad libitum (n=10/housing/season). Mounting behaviour was observed for 3 h during the third (M3), fourth (M4) and fifth (M5) months of age. The total number of skin lesions was counted on both sides of the pigs 1 day before the behavioural recordings. The time spent in the outdoor run was also recorded during 3 days per month. The animals were slaughtered at 161±1 days of age (122±9 kg live weight). Blood samples were collected at 89 (M3), 119 (M4) and 152 (M5) days of age and at slaughter for the testosterone and oestradiol measurements. The testes were collected at slaughter, freed from the surrounding tissues and weighed. The fat samples were collected for the androstenone and skatole concentration measurement. Plasma testosterone and oestradiol-17β (oestradiol), fat androstenone and skatole and weight of the testes did not differ between the housing systems. Plasma testosterone (8.3 v. 3.9 nmol/l, P<0.05) and oestradiol (12.0 v. 9.2 pmol/l, P<0.1) at M3, fat skatole (0.124 v. 0.043, P<0.03) and weight of the testes (587 v. 512 g, P<0.05) were higher in the autumn than in the spring trial, suggesting that the pubertal development was accelerated. The number of received mounting behaviours was slightly higher in the autumn (P=0.08) trial and was markedly higher in the E than in the C environment (P<0.003). Skin lesions were more numerous in the C than in the E housing at M4 and M5 and in the spring than in the autumn trial at M3 and M4 (P<0.05). Fat androstenone and the number of performed mounting behaviours were significantly correlated between each other and with numerous indicators of the pubertal development (P<0.05). The number of skin lesions was correlated with plasma testosterone and live weight (P<0.05). Overall, this study suggests the effect of season on sexual development, the effect of the housing system on behaviour, and demonstrates the links between sexual hormones, behaviour and boar taint.     

Association between age at first calving,year and season of first calving and milk production in Holstein cows

The effects of first calving (FC) in Holstein heifers on their first lactation, second lactation and lifetime milk production were examined from an initial database of 459 743 animals that first calved between 1 January 1990 and 31 July 2010 in Wallonia, Belgium. The FC age class (18 to 22, 22 to 26, 26 to 30, 30 to 34, 34 to 38 and 38 to 42 months), the FC season and FC year class (1990 to 1994, 1995 to 1999, 2000 to 2004 and 2005 to 2010) were considered when analysing the first and second lactation data. Lifetime data were similarly analysed, but did not include animals that calved after 2005 because many of them were still lactating. Only 24% of animals had their FC before 26 months of age. Animals that first calved between 22 and 26 months of age had more lactations and productive days during their life. They also had higher first and second lactation milk production and lifetime milk production. Summer or autumn FC improved first lactation, second lactation and lifetime milk production, as well as production per day of lactation, compared with winter or spring FC. Compared with animals that calved for the first time in 1990 to 1994, animals with a FC in 2000 to 2004 had a longer calving interval (0.5 months), fewer lactations per animal (−0.6) and fewer days in their lifetime lactation (a reduction of 144 days). As a result, the animals’ lifetime production did not increase between 1990 to 1994 and 2000 to 2004, although milk production per day of lactation (22.85v. 20.49 l/day) and per day of life (11.49v. 10.78 l/day) improved. Milk fat content was lower in 2000 to 2004 than in 1990 to 1994, but protein content remained relatively constant, probably because of the cows’ higher production level and increased dietary concentrate supplementation.     

The relationship between consumption of tyrosine and phenylalanine as precursors of catecholamine at breakfast and the circadian typology and mental health in Japanese infants aged 2 to 5 years

Background

This study aims to examine the relationship between tyrosine and phenylalanine intake at breakfast as precursors of dopamine, and scores on the Torsvall-Åkerstedt Diurnal Type Scale and of mental health in Japanese infants aged 2 to 5 years.

Results

An integrated questionnaire was administered to parents of 1,367 infants attending one of ten nursery schools governed by Kochi City or a kindergarten affiliated with the Faculty of Education at Kochi University (775 answers for analysis: 56.7%) in May and June 2008. Questionnaires included the Torsvall-Åkerstedt Diurnal Type Scale and questions on sleep habits (onset, offset, quality, quantity, and so on), meal habits (content and regularity of timing), and mental health (depressive states). Amount of tyrosine and phenylalanine intake was calculated based on a breakfast content questionnaire and data on the components of amino acids in foods. Infants who ingested more than 800 mg of tyrosine or phenylalanine at breakfast per meal were more morning-type than those who ingested less than 800 mg (ANOVA: P= 0.005). However, this relationship disappeared in the ANCOVA analysis (with the covariance of tryptophan intake, P= 0.894). Infants who ingested more than 800 mg of the two amino acids at breakfast showed significantly higher mental health scores (lower frequency of depressive states) than those who ingested less than 800 mg (ANOVA: P = 0.004). This relationship remained significant when ANCOVA analysis was performed with the covariance of tryptophan (ANCOVA: P= 0.017).

Conclusions

These results suggest that tyrosine and phenylalanine ingested at breakfast are not related with circadian phase, but are relate with mental health in infants.