神经鞘磷脂合成酶2缺乏对小鼠学习记忆能力的影响

目的：探讨神经鞘磷脂合成酶2缺乏对小鼠学习记忆能力的影响,方法：实验采用雄性的野生型小鼠（WT）和神经鞘磷脂酶合成酶2缺乏小鼠（KO）,每组10只,采用Morris水迷宫实验进行7 d的定位航行试验检测,之后进行空间探索试验,以检测小鼠的学习记忆能力。结果：定位航行试验检测结果显示,两组小鼠找到平台的潜伏期、游泳距离均无显著性差异（P > 0.05）;空间探索试验检测结果显示,两组小鼠的目标象限滞留时间占总时间的百分比和小鼠穿越平台区的次数也无显著性差异（P > 0.05）;但野生型小鼠的搜索策略优于神经鞘磷脂合成酶2缺乏小鼠（P < 0.05）。结论：神经鞘磷脂合成酶2缺乏影响小鼠的搜索策略,但不影响小鼠的空间学习记忆能力。     

Individuality of distress and discomfort calls in neonates with bass voices: Wild‐living goitred gazelles (Gazella subgutturosa) and saiga antelopes (Saiga tatarica)

Neonate ruminants produce distress calls when captured by a predator and discomfort milk begging calls when hungry. In many neonate ruminants, the distress and discomfort calls are high‐frequency vocalizations, in which the fundamental frequency is the key variable for recognition of their emotional arousal by caregivers. In contrast, in this study, we examine the low‐frequency open‐mouth distress and discomfort calls in the neonates of two species of wild‐living ungulates, which clearly highlight vocal tract resonances (formants). In the goitred gazelle (Gazella subgutturosa), the distress calls were higher in fundamental frequency (f0) and in the first and third formants than the discomfort calls. The accuracy of classifying individuals by variables of distress calls with discriminant function analysis (67%) was significantly lower than that of discomfort calls (85%). In the saiga (Saiga tatarica), only the third formant was higher in the distress calls than in the discomfort calls. The accuracy of classifying individuals by variables of distress calls (89%) did not differ significantly from that of discomfort calls (94%). Thus, the use of acoustic cues to vocal identity and to the degree of arousal differs between the two species. Calls were significantly more individualistic in the saiga, probably because this species lives in large herds and neonates use a ‘following’ antipredatory strategy, in which vocal individuality is crucial for mother–offspring communication. In contrast, goitred gazelles live in smaller groups and neonates use a ‘hiding’ antipredatory strategy. Accordingly, mothers can rely on additional environmental cues for spotting their young and this may decrease the necessity for individualization of the calls of neonates.     

Stoichiometric and nutrient resorption characteristics of dominant tree species in subtropical Chinese forests

This study investigated seasonal patterns in stoichiometric ratios, nutrient resorption characteristics, and nutrient use strategies of dominant tree species at three successional stages in subtropical China, which have not been fully understood. Fresh leaf and leaf litterfall samples were collected in growing and nongrowing seasons for determining the concentrations of carbon (C), nitrogen (N), and phosphorus (P). Then, stoichiometric ratios (i.e., C:N, C:P, N:P, and C:N:P) and resorption parameters were calculated. Our results found that there was no consistent variation in leaf C:N and C:P ratios among different species. However, leaf N:P ratios in late‐successional species became significantly higher, indicating that P limitation increases during successional development. Due to the P limitation in this study area, P resorption efficiency and proficiency were higher than corresponding N resorption parameters. Dominant tree species at early‐successional stage adopted “conservative consumption” nutrient use strategy, whereas the species at late‐successional stage inclined to adopt “resource spending” strategy.     

The best strategy of blood transfusion in patients with Rhnull syndrome

Rh_null syndrome is a very rare disease. Patients with this syndrome present with negative serological Rh typing of E, e, C, c, and D antigens. Only one study has previously discussed Rh_null syndrome in Chinese individuals. We experienced two patients with Rh_null syndrome in China, Rh genotypes being CcDEe in the first patient and CCDee in the second patient. The first patient was a pregnant woman (gravida 2, para 1) with a negative red blood cell (RBC) antibody screen test. The second patient was a middle-aged man, transfused with ccdee, ccdEe, and ccdee RBC products, the pre-transfusion specimen was negative and post-transfusion specimen was anti-c,e, respectively. The hemoglobin level continued to increase in the second patient after being transfused with ccdEe RBC products. In the first patient, the result of the antibody screen test was still negative after artificial abortion. In patients with Rh_null syndrome, RBC products that have the same Rh genotype as the patient can be safely transfused.     

Industrial Symbiosis Dynamics and the Problem of Equivalence: Proposal for a Comparative Framework

Industrial symbiosis (IS), one of the founding notions within the field of industrial ecology, has diffused throughout significant parts of the world as a practice that can reduce the ecological impact of the industrial processes of groups of firms. In this article, we propose a fresh look at this research topic, building on the considerable advances that have been made in the last 15 years in understanding how IS comes about. We propose a conceptual and theoretical framework for taking on the challenge of comparative analysis at a global level. This requires developing an approach to address a solution to the problem of equivalence: the difficulty of comparing instances of IS across different institutional contexts. The proposed framework emphasizes IS as a process and attempts to address the obstacles to comparative study by (1) identifying terminology to examine IS variants, (2) providing a typology of IS dynamics, and (3) formulating key research questions to illuminate a way forward. In developing our argument, we build on the collective experiences of collaborative research efforts in North America, Europe, and Asia as evidenced in recent overviews of the literature.     

Life history strategy and human cooperation in economic games

Across five studies using samples from both Japan and United States (N = 2345), we take a multi-method approach to test the prediction from life history theory that a slow, compared to fast, life history strategy promotes investment in cooperative relationships. Studies 1 and 2 examined how different measures as proxies for life history strategy (i.e., Mini-K and High-K Strategy Scale) relate to cooperation in various economic games. Studies 3 to 5 measured early childhood environments (i.e., childhood harshness and unpredictability), manipulated resource scarcity using previously validated methods, and then measured cooperation. Across our studies, we also examined four hypothesized psychological mechanisms that could explain the relation between life history strategy and cooperation: temporal discounting, concern for reputation, social value orientation, and trust in others. Overall, we found no support for the hypothesis that life history strategy predicts cooperation or that early childhood environments interact with current resource scarcity to predict cooperation. Thus, our initial findings imply that life history theory may not account for individual variation in cooperation with unknown others.     

Life history strategies and psychopathology: the faster the life strategies,the more symptoms of psychopathology

There is little extant empirical literature examining the associations between life history strategies and symptoms of psychopathology. The current study (N = 138) investigated the associations between life history strategies, symptoms of psychopathology, aggression, incidence of self-harm behaviour, and attachment (perceived parental support) in sample drawn from the general population and community mental health service providers. The results from the study indicate those with a faster life strategy report greater levels of aggression and symptoms of psychopathology. Further, perceptions of poorer parental support were associated with a faster life history strategy. Implications for life history theory, conceptualising psychopathology, and future research directions are discussed.     

微生物辅因子平衡的代谢调控

辅因子平衡对于酶制剂、药品和化学品的生产具有重要的作用。为了满足工业化生产的需求,维持辅因子长期有效的平衡是实现代谢流高效化导向目标代谢产物的必要手段。本文在总结辅因子生理功能的基础上,从生化工程和代谢工程两方面分析归纳了辅因子的代谢调控策略,并展望了辅因子进一步精深调控的发展方向。