Hair cortisol concentrations correlate negatively with survival in a wild primate population

Background

Glucocorticoid hormones are known to play a key role in mediating a cascade of physiological responses to social and ecological stressors and can therefore influence animals’ behaviour and ultimately fitness. Yet, how glucocorticoid levels are associated with reproductive success or survival in a natural setting has received little empirical attention so far. Here, we examined links between survival and levels of glucocorticoid in a small, short-lived primate, the grey mouse lemur (Microcebus murinus), using for the first time an indicator of long-term stress load (hair cortisol concentration). Using a capture-mark-recapture modelling approach, we assessed the effect of stress on survival in a broad context (semi-annual rates), but also under a specific period of high energetic demands during the reproductive season. We further assessed the power of other commonly used health indicators (body condition and parasitism) in predicting survival outcomes relative to the effect of long-term stress.

Results

We found that high levels of hair cortisol were associated with reduced survival probabilities both at the semi-annual scale and over the reproductive season. Additionally, very good body condition (measured as scaled mass index) was related to increased survival at the semi-annual scale, but not during the breeding season. In contrast, variation in parasitism failed to predict survival.

Conclusion

Altogether, our results indicate that long-term increased glucocorticoid levels can be related to survival and hence population dynamics, and suggest differential strength of selection acting on glucocorticoids, body condition, and parasite infection.

     

Development,and genetic and metabolic characterization of new tomato mutants with enhanced and deficient carotenoid content

Tomato (Solanum lycopersicum) is a valuable vegetable crop rich in health-protective carotenoids, but breeding improvements are limited by its narrow genetic diversity. New mutants with enhanced and deficient carotenoid content in a single genetic background of tomato cv. MicroTom were developed via chemical mutagenesis. Genetic and metabolic analyses showed that mutant DC260, which exhibited fruit color alteration from red to deep red interlaced with orange color, had significant (P < 0.05) increases of lycopene (up to 42.8%) and ß-carotene (up to 61.5%) compared with control plants. Pearson correlation analysis of M1 and M2 generations in DC260 revealed that fruit color alteration was significantly (P < 0.05) correlated with lycopene (coefficient = 0.55) and ß-carotene content (coefficient = 0.63). The fruit color alteration of DC260 was controlled by a single gene at a heterozygous locus. In contrast, mutant DC107 and DC624, which exhibited fruit color alteration from red to orange-yellow, was significantly (P < 0.05) carotenoid-deficient with up to 346.3-, 10.8-, and 185.2- fold reductions of lycopene, ß-carotene, and total carotenoids, respectively, compared with the control plants. Carotenoid deficiency in DC170 and DC624 was responsible for the fruit color alteration and was controlled by a dominant gene at a homozygous locus.     

远程培训助推新农村建设的成效及问题分析——基于闽南农村实用技术远程培训状况的调研

农民是将农业科学技术转化为生产力的最终应用者,农村实用技术远程培训可以提高农民应用农业科学技术的效率。对闽南农村实用技术远程培训的现状及成效进行调研后,笔者叙述了农村实用技术远程培训对促进特色农业产业、无公害蔬菜产业、沼气技术产业发展,对促进新农村建设、农村劳动力转移、农民增收致富产生的显著作用,并分析了远程培训存在的亟待解决的问题,提出了采用多渠道弥补远程培训的不足之处,开展区域特色农业远程培训,分层次进行远程培训以满足不同文化水平农民的技术需求、开阔农民的视野、转变农民的观念的对策与建议。     

Dielectric spectroscopy of Scots pine

Dielectric properties of Scots pine (42 trees) were compared with density, moisture content (MC), and resin acid content (RAC) (of heartwood). The samples were measured in frozen, green, conditioned and non-conditioned dry moisture states to evaluate the potential of dielectric spectroscopy in determining the wood characteristics at different stages of wood processing. Heartwood and sapwood parts of each sample were measured separately, and through-transmission measurement was conducted in longitudinal and tangential direction at frequencies from 1 MHz to 1 GHz. The MC and density correlated significantly with the dielectric parameters in both measurement directions but especially in longitudinal direction. The RAC of the heartwood correlated significantly with tanδ and ε″/(ε′ ? 1) of the green samples measured in the tangential direction at frequencies above 200 MHz. The correlation at 1 GHz was ?0.56 for green samples, ?0.66 for conditioned samples and ?0.61 for non-conditioned samples (P < 0.001, for all). The study suggests that the extractives also affect radio-frequency dielectric responses, which might be used for extractive analyses of pine heartwood.     

The effect of brown-rot decay on water adsorption and chemical composition of Scots pine heartwood

? The effect of brown-rot (Coniophora puteana) decay on the water adsorption capacity and concentration of extractives of Scots pine (Pinus sylvestris L.) heartwood were studied by comparing corresponding properties of decayed and undecayed wood samples.

? The samples derived from 39 felled trees having a large between-tree variation in the extractive concentrations, and subsequently in the mass loss in the decay test. The water adsorption capacity, expressed as equilibrium moisture content (EMC), was measured at a high relative humidity (RH ～100%, 21 °C).

? In contrast to the widely held belief, the water adsorption capacity of brow-rotted heartwood appeared to be significantly higher than that of undecayed heartwood.

? The chemical composition of heartwood was changed radically by the fungus: the concentration of stilbenes, resin acids and free fatty acids decreased, while the concentration of soluble sugars increased as a result of decay. In addition, fungal sugars were found in the decayed samples. The concentration of total phenolics increased, which obviously reflected chemical changes in cell wall constituents other than extractives.

? As a conclusion, the information concerning the hygroscopicity of brown-rotted wood might be valuable e.g. when carrying out repairs on buildings damaged by advanced decay.

     

3种免疫增强剂对猪伪狂犬灭活疫苗的免疫效果评价

【目的】评价盐酸左旋咪唑(LH)、刀豆素(ConA)和胞壁酰二肽(MDP)3种免疫增强剂对猪伪狂犬病毒(PRV)灭活疫苗的免疫增强作用。【方法】将免疫增强剂混入灭活的PRV水相,和油相乳化后制成相应含有免疫增强剂的灭活疫苗,使各免疫增强剂终剂量为:LH 7.5 mg·mL~(–1)、ConA 25.0 mg·mL~(–1)、MDP 150.0 mg·mL~(–1)。首次免疫后14 d进行二次免疫,首次免疫后14 d、二次免疫后7和14 d采取小鼠血清,检测相关的细胞因子和特异性抗体水平,并在二次免疫后14 d攻毒,计算最终的攻毒保护率。【结果】相对于白油组,ConA组和MDP组在二次免疫后14 d对小鼠白介素2(IL-2)含量提升效果极显著;LH组在首次免疫后14 d、MDP组在二次免疫后14 d对白介素4(IL-4)含量提升效果显著;3种免疫增强剂分别在二次免疫后14和7 d对干扰素(IFN-γ)和特异性抗体含量提升效果极显著,并提高了攻毒保护率,LH组和ConA组存活率为20%,MDP组存活率为60%。【结论】3种免疫增强剂使用试验剂量均能不同程度地提升猪伪狂犬灭活疫苗的免疫效果,具有较好的应用前景。本研究结果为后续复合免疫增强剂筛选打下了基础。     

泵站水力瞬变的二阶Godunov格式模型构建

为了提高复杂泵站系统水力瞬变数值模拟的高效性和稳定性,该研究基于泵站系统水力瞬变问题,建立有限体积法Godunov格式的数学模型,对简单管道系统和复杂泵站系统进行模拟研究。与常用的特征线法求解泵站水力模型方程不同,该模型引进有限体积法二阶Godunov格式对模型进行离散,用Riemann求解器对离散通量进行求解。使用MUSCL-Hancock方法进行界面数值重构,采用MINMOD斜率限制器避免虚假震荡。提出双虚拟单元边界处理方法,实现计算区域与边界同时达到二阶精度。将所建模型计算结果与精确解、经典算例数据进行对比,并针对库朗数取值和计算网格数进行敏感性分析。结果表明：所建模型模拟结果与精确解、经典算例数据吻合较好;与特征线法相比,二阶Godunov格式更加准确、稳定且高效。对于简单管道系统,特征线法计算耗时0.227 s,二阶Godunov格式计算耗时0.017 s。对于实际泵站系统,由于存在多特性的管道结构,二阶Godunov格式模拟时需稍微降低库朗数。而采用特征线法进行泵站水力过渡过程计算时,若不调整管道长度或者波速,管道中库朗数会小于1,在本文算例中,库朗数为0.72～0.76,模拟计算结果偏差很大。所以需要调整局部管道长度或波速,以达到库朗数为1的条件,这样处理因改变管道特性而引入计算误差。综上,二阶Godunov格式模拟方法可以更有效提高传统泵站系统水力瞬变模拟的高效性、稳定性以及准确性。     

Relationship between postnatal piglet mortality,environmental factors and management around farrowing in herds with loose-housed,lactating sows

Abstract

The objective of this study was to investigate management routines and environmental factors influencing postnatal piglet mortality in commercial herds with individually loose-housed sows. Last year production records from 39 herds were used. We gathered information on specific routines as well as environmental factors by visiting every farm once. Herds practising moderate roughage feeding during pregnancy tended to have lower piglet mortality (p=0.06). Use of farrowing rails along all the sides of the pen resulted in lower piglet mortality than when no rails were present (p<0.01). Herds that hardly used any litter in the sow area at the time of farrowing had significantly higher piglet mortality than herds that used a moderate or large amount (p<0.05). Helping the piglets to obtain colostrum immediately after birth also reduced mortality (p<0.05), whereas other routines such as shutting the piglets inside the creep area while feeding the sow did not have any significant effect.