月季花瓣数量遗传分析

以‘窄叶藤本月季花’( Rosa chinensis ‘Zhaiye Tengben Yuejihua’)ב月月粉’( R. chinensis ‘Old Blush’)杂交群体为材料, 分析其花瓣数量的分离特点, 对单瓣花与重瓣花的花芽分化过程进行观察, 并对花瓣、雄蕊及瓣化雄蕊进行表皮细胞超微结构的观察.结果显示...     

采用数据挖掘技术对湖北省人类狂犬病开展生物信息学研究

狂犬病作为一种急性人畜共患疾病,其致死率接近100％.而湖北省作为我国中部狂犬病高发地之一,开展该省狂犬病的流行病学调查不仅有助于了解我国当前面临的狂犬病疫情风险,还能为当地及全国狂犬病防控工作提供有效的参考意见.首先运用描述性分析发现湖北省狂犬病发病人数随时间呈下降趋势,而狂犬病暴露人数则呈上升趋势,且近年来中西部地...     

Knowledge,attitudes, and practices regarding schistosomiasis infection and prevention: A mixed-methods study among endemic communities of western Uganda

IntroductionIn Uganda, schistosomiasis (re)infections have continued to remain high despite the implementation of mass drug administration and sensitization campaigns aimed at controlling the disease. This could imply that there are some barriers to the implemented preventive measures. We conducted a mixed-methods study in Kagadi and Ntoroko districts around Lake Albert to assess knowledge, attitudes, and practices regarding schistosomiasis and to explore and understand perspectives regarding the disease.Materials and methodsSemi-structured survey questionnaires were administered to 337 household adults selected through systematic random sampling. We also interviewed 12 participants and held 28 focus-group discussion sessions with 251 individuals respectively. Quantitative data was analysed using frequencies, percentages, and chi-square tests for associations, while themes and sub-themes were used to analyse qualitative data respectively.FindingsA total of 98.5%, 81.3%, and 78.5% had heard about schistosomiasis, and knew the main transmission modes and symptoms, respectively. The majority (75.8%) said avoiding contact with water was a preventative way, while 67.5% said observing signs and symptoms was a form of diagnosis. Furthermore, 98.4% and 73.4% said it was important to defecate in latrines and to avoid contact with contaminated water respectively. However, it is difficult to avoid contact with lake water because it is the only source of livelihood, especially for fisher communities. Open defecation is commonly practiced along the lake due to insufficient space and difficulties in the construction of latrines. Myths and misconceptions reported include; lake water is safe, gassing in water causes transmission, fetching water early in the morning and from deep water is safe, and feces in the lake water act as a bait for catching fish.Conclusions and recommendationsDespite adequate knowledge of schistosomiasis and a positive attitude towards its prevention, existing myths and misconceptions, coupled with persistent risky water, sanitation, and hygiene practices still pose a challenge. A more robust community-based awareness intervention using bottom-up participatory approaches, accompanied by the provision of clean and safe water sources and increasing latrine coverage, could provide lasting solutions to these barriers.     

The group size effect and synchronization of vigilance in the Tibetan wild ass

Vigilance behavior is considered as an effective strategy for prey species to detect predators.An individual benefits from living in a group by reducing the time spent being vigilant without affecting the probability of detecting a predator.However,the mechanism producing a decrease in vigilance with increasing group size is unclear.Many models of vigilance assume that group members scan independently of one another.Yet in recent studies,the other 2 patterns of vigilance,coordination and synchronization,were reported in some species.In 2 summers(2018 and 2019),we studied the group-size effect on vigilance and foraging of Tibetan wild ass in Chang Tang Nature Reserve of Tibet.We also tested whether individuals scan the environment independently,tend to coordinate their scans,or tend to synchronize their vigilance.The results showed that individuals decreased the time spent on vigilance with increasing group size,while increased the time spent foraging.Group members scanned the environment at the same time more frequently and there was a positive correlation between group members'behaviors,indicating that Tibetan wild asses tend to synchronize their vigilance.     

Simulated Microgravity Induces the Proliferative Inhibition and Morphological Changes in Porcine Granulosa Cells

Astronauts are always faced with serious health problems during prolonged spaceflights. Previous studies have shown that weightlessness significantly affects the physiological function of female astronauts, including a change in reproductive hormones and ovarian cells, such as granulosa and theca cells. However, the effects of microgravity on these cells have not been well characterized, especially in granulosa cells. This study aimed to investigate the effects of simulated microgravity (SMG) on the proliferation and morphology of porcine granulosa cells (pGCs). pGC proliferation from the SMG group was inhibited, demonstrated by the reduced O.D. value and cell density in the WST-1 assay and cell number counting. SMG-induced pGCs exhibited an increased ratio of cells in the G0/G1 phase and a decreased ratio of cells in the S and G2/M phase. Western blot analysis indicated a down-regulation of cyclin D1, cyclin-dependent kinase 4 (cdk4), and cyclin-dependent kinase 6 (cdk6), leading to the prevention of the G1-S transition and inducing the arrest phase. pGCs under the SMG condition showed an increase in nuclear area. This caused a reduction in nuclear shape value in pGCs under the SMG condition. SMG-induced pGCs exhibited different morphologies, including fibroblast-like shape, rhomboid shape, and pebble-like shape. These results revealed that SMG inhibited proliferation and induced morphological changes in pGCs.     

RNA pseudoknots downstream of the frameshift sites of retroviruses.

RNA pseudoknot structural motifs could have implications for a wide range of biological processes of RNAs. In this study, the potential RNA pseudoknots just downstream from the known and suspected retroviral frame-shift sites were predicted in the Rous sarcoma virus, primate immunodeficiency viruses (HIV-1, HIV-2, and SIV), equine infectious anemia virus, visna virus, bovine leukemia virus, human T-cell leukemia virus (types I and II), mouse mammary tumor virus, Mason-Pfizer monkey virus, and simian SRV-1 type-D retrovirus. Also, the putative RNA pseudoknots were detected in the gag-pol overlaps of two retrotransposons of Drosophila, 17.6 and gypsy, and the mouse intracisternal A particle. For each sequence, the thermodynamic stability and statistical significance of the secondary structure involved in the predicted tertiary structure were assessed and compared. Our results show that the stem-loop structures in the pseudoknots are both thermodynamically highly stable and statistically significant relative to other such configurations that potentially occur in the gag-pol or gag-pro and pro-pol junction domains of these viruses (300 nucleotides upstream and downstream from the possible frameshift sites are included). Moreover, the structural features of the predicted pseudoknots following the frameshift site of pro-pol overlaps of the HTLV-1 and HTLV-2 retroviruses are structurally well conserved. The occurrence of eight compensatory base changes in the tertiary interaction of the two related sequences allow the conservation of their tertiary structures in spite of the sequence divergence. The results support the possible control mechanism for frameshifting proposed by Brierley et al. and Jacks et al.