自动测序仪的发明者--记科学家胡德

DNA自动测序仪的发明实现了DNA测序的自动化,从而大大促进了基因测序的进程．对于人类基因组计划的实施具有极大的推动作用,今天DNA自动测序仪G成为分子生物学研究中不可缺少的仪器,对于生命科学的蓬勃发展做出了巨大贡献。简要介绍自动测序仪的发明者胡德教授的生平,了解这位科学家的贡献和测序仪的发明过程。     

The Phylogeny of Little Red Riding Hood

Researchers have long been fascinated by the strong continuities evident in the oral traditions associated with different cultures. According to the ‘historic-geographic’ school, it is possible to classify similar tales into “international types” and trace them back to their original archetypes. However, critics argue that folktale traditions are fundamentally fluid, and that most international types are artificial constructs. Here, these issues are addressed using phylogenetic methods that were originally developed to reconstruct evolutionary relationships among biological species, and which have been recently applied to a range of cultural phenomena. The study focuses on one of the most debated international types in the literature: ATU 333, ‘Little Red Riding Hood’. A number of variants of ATU 333 have been recorded in European oral traditions, and it has been suggested that the group may include tales from other regions, including Africa and East Asia. However, in many of these cases, it is difficult to differentiate ATU 333 from another widespread international folktale, ATU 123, ‘The Wolf and the Kids’. To shed more light on these relationships, data on 58 folktales were analysed using cladistic, Bayesian and phylogenetic network-based methods. The results demonstrate that, contrary to the claims made by critics of the historic-geographic approach, it is possible to identify ATU 333 and ATU 123 as distinct international types. They further suggest that most of the African tales can be classified as variants of ATU 123, while the East Asian tales probably evolved by blending together elements of both ATU 333 and ATU 123. These findings demonstrate that phylogenetic methods provide a powerful set of tools for testing hypotheses about cross-cultural relationships among folktales, and point towards exciting new directions for research into the transmission and evolution of oral narratives.     

Evaluation of the Edgegard Laminar Flow Hood

In a horizontal back-to-front flow high-efficiency particulate air-filtered laminar hood, it is shown that a Blake bottle obstruction to the air flow causes a downstream cone of turbulent air which can draw microbial contamination into the work area of the hood. In controlled experiments, contamination with T3 coliphage was reduced by a series of perforations around the open edge of the hood which eliminates the cone of turbulent air. The average reduction in phage counts was 90.75, 86.79, 91.12, and 98.92%, depending upon the site of nebulization. The phage counts were reduced in 48 of the 51 tests.     

Biohazard Hood to Prevent Infection During Microbiological Procedures

A microbiological hood was designed to reduce the danger of airborne infection of laboratory workers. The hood uses absolute filters to deliver sterile air in a laminar flow to the work area. An air curtain across the hood opening permits easy access but separates the worker from aerosols produced in the hood, and protects material inside the hood from contamination by room air. Tests with bacterial and viral aerosols showed that the air curtain is at least 99.96% effective in preventing airborne particles from entering the work area.     

Nitric Oxide Administration Using an Oxygen Hood: A Pilot Trial

Background

We have shown earlier that inhaled nitric oxide (iNO) administered by oxygen hood reduces pulmonary hypertension in an animal model (J Perinatol 2002; 22:50-6). Our objective in this study was to determine feasibility of iNO by oxygen hood in neonates with elevated alveolar-arterial oxygen gradients (A-aDO₂).

Methods/Principal Findings

Masked randomized controlled pilot trial. Inclusion criteria were: gestation≥34 weeks, age<7 days, with post-ductal arterial line, and A-aDO₂ 400–600. Infants were randomized to study gas (iNO 20 ppm or equivalent O₂ flow) for 1 hr which was then weaned over the next 4 hours. Primary outcome was PaO₂ one hour post-randomization. Four infants each were randomized to iNO or O₂ (controls). Two of the four infants given iNO had an increase in PaO₂ of >100 torr, while oxygenation was unchanged in the controls. Methemoglobinemia and other adverse effects were not noted in any infant. Environmental levels of NO and NO₂ were minimal (<1 ppm) at >0.3 m from the hood.

Conclusions

Administration of iNO by oxygen hood is feasible. Larger randomized controlled trials are required to measure the efficacy and determine an appropriate target population for this technique.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00041548","term_id":"NCT00041548"}}NCT00041548     

透明帽辅助结肠镜单人操作在老年患者检查中的临床应用

目的:探讨透明帽辅助结肠镜单人操作在老年患者检查中的临床应用.方法:对2009年8月至12月来我院消化内镜中心进行检查的408例年龄大于60岁的患者,随机分成A组(204例)和B组(204例),全部检查均在非麻醉状态下操作.A组予以透明帽辅助结肠镜检查,B组行常规结肠镜检查.对两种方法的成功率、平均插镜时间、平均疼痛评分、息肉检出率等指标进行比较.针对性别、年龄、腹部或盆腔手术史、长期便秘、肠道憩室等指标分析插镜时间的影响因素.结果:A组和B组结肠镜检查的成功率分别为99.1%和98.5%.平均插镜时间分别为6.4 min和10.8 min(P＜0.05).平均疼痛分数分别为5.8分和5.1分.息肉检出率分别为70.6%和49.5%(P＜0.05).全部检查无并发症发生.在插镜时间的影响因素中,女性、年龄＞80岁、腹部或盆腔手术史、长期便秘等因素有显著差异(P＜0.05).结论:透明帽辅助结肠镜单人操作对于老年患者是一种安全、插镜时间较短、息肉检出率较高的检查方法,年龄超过80岁的老年女性、有腹部或盆腔手术史、长期便秘是导致插镜时间延长的相关因素.     

短时低温对茶黄蓟马发育与繁殖的影响

蓟马是芒果的重要害虫,为探明短时低温对蓟马发育与繁殖的影响,以为害芒果的蓟马优势种茶黄蓟马Scirtothrips dorsalis为对象,将其放置于8℃和12℃(RH 75%±10%, 12 L∶12 D)人工气候箱内,分别处理6 h、12 h及24 h,观察若虫的存活率、发育历期及成虫寿命和繁殖力。结果表明：短时低温暴露对茶黄蓟马若虫的发育历期有一定的影响,不同龄期对低温的响应有所不同,若虫期经历短时低温会显著降低成虫寿命;短时低温暴露对所处理龄期及世代的存活能力均造成显著影响,处理温度越低时间越长,存活率下降越显著,其中2龄若虫在8℃下处理24 h,若虫期的累计存活率最低,仅6.86%。结果说明短时低温暴露后对成虫寿命和产卵量均产生不利的影响,处理温度越低时间越长,影响越大。     

Haul-out behavior of harbor seals (Phoca vitulina) in Hood Canal, Washington

The goal of this study was to model haul-out behavior of harbor seals (Phoca vitulina) in the Hood Canal region of Washington State with respect to changes in physiological, environmental, and temporal covariates. Previous research has provided a solid understanding of seal haul-out behavior. Here, we expand on that work using a generalized linear mixed model (GLMM) with temporal autocorrelation and a large dataset. Our dataset included behavioral haul-out records from archival and VHF radio tag deployments on 25 individual seals representing 61,430 seal hours. A novel application for increased computational efficiency allowed us to examine this large dataset with a GLMM that appropriately accounts for temporal autocorellation. We found significant relationships with the covariates hour of day, day of year, minutes from high tide and year. Additionally, there was a significant effect of the interaction term hour of day : day of year. This interaction term demonstrated that seals are more likely to haul out during nighttime hours in August and September, but then switch to predominantly daylight haul-out patterns in October and November. We attribute this change in behavior to an effect of human disturbance levels. This study also examined a unique ecological event to determine the role of increased killer whale (Orcinus orca) predation on haul-out behavior. In 2003 and 2005 these harbor seals were exposed to unprecedented levels of killer whale predation and results show an overall increase in haul-out probability after exposure to killer whales. The outcome of this study will be integral to understanding any changes in population abundance as a result of increased killer whale predation.     

Distribution,abundance, and density of harbor porpoises in Hood Canal,Washington

Harbor porpoises (Phocoena phocoena) are the only cetaceans routinely sighted in Hood Canal, a narrow fjord that comprises the western edge of Puget Sound, Washington, USA. Harbor porpoises are sensitive to anthropogenic sounds, including noise from recreational and commercial vessel traffic, and the United States Navy, which conducts military training and testing within Hood Canal that can include underwater sound sources. This study was funded as part of the Navy monitoring program to assess potential impacts of naval activities on cetaceans. We conducted vessel-based line-transect surveys for harbor porpoises in Hood Canal in 2022–2023 to derive seasonal estimates of abundance and density. We carried out surveys over 37 days and surveyed the entire canal twice per season totaling 2,176 km of on-effort track line. We recorded 809 on-effort harbor porpoise groups and 1,385 individuals. Seasonal abundance estimates were lowest in winter (308 animals, 95% CI = 189–503) and gradually increased through spring and summer to a peak of 1,336 animals (95% CI = 826–2,160) in fall. Overall porpoise density was highest in central Hood Canal, an area that includes a designated United States Navy training range, though porpoise sightings were notably absent in a 21-km² area adjacent to the naval submarine base within this otherwise high-density region. Though we collected only a single year of data, these results suggest that harbor porpoise abundance in Hood Canal increased significantly since it was last estimated (2013–2015). The notable seasonal fluctuation of harbor porpoise abundance suggests Hood Canal may host a larger percentage of the overall Washington Inland Waters stock during the fall season, raising important management considerations.     

Variation in the Early Marine Survival and Behavior of Natural and Hatchery-Reared Hood Canal Steelhead

Background

Hatchery-induced selection and direct effects of the culture environment can both cause captively bred fish populations to survive at low rates and behave unnaturally in the wild. New approaches to fish rearing in conservation hatcheries seek to reduce hatchery-induced selection, maintain genetic resources, and improve the survival of released fish.

Methodology/Principal Findings

This study used acoustic telemetry to compare three years of early marine survival estimates for two wild steelhead populations to survival of two populations raised at two different conservation hatcheries located within the Hood Canal watershed. Steelhead smolts from one conservation hatchery survived with probabilities similar to the two wild populations (freshwater: 95.8–96.9%, early marine: 10.0–15.9%), while smolts from the other conservation hatchery exhibited reduced freshwater and early marine survival (freshwater: 50.2–58.7%, early marine: 2.6–5.1%). Freshwater and marine travel rates did not differ significantly between wild and hatchery individuals from the same stock, though hatchery smolts did display reduced migration ranges within Hood Canal. Between-hatchery differences in rearing density and vessel geometry likely affected survival and behavior after release and contributed to greater variation between hatcheries than between wild populations.

Conclusions/Significance

Our results suggest that hatchery-reared smolts can achieve early marine survival rates similar to wild smolt survival rates, and that migration performance of hatchery-reared steelhead can vary substantially depending on the environmental conditions and practices employed during captivity.     

The Robin Hood Narrative: A Discussion of Empirical and Ethical Legitimizations of Somali Pirates

The pirates of Somalia pose a major challenge for the international community, both economically and morally. Somali pirates try to legitimize their actions by reference to a number of arguments that appeal to the international community. Allegedly, the illegal fishing and waste dumping in Somali waters were the triggers for piracy. Hence, the pirates want to protect their coasts. These various strands form the so-called legitimacy Robin Hood narrative. In this article, this narrative is critically examined. The analysis includes a discussion of justice theories and related claims based on the works of John Rawls and Thomas Pogge. This is followed by a discussion of the justification of violence using Nicholas Fotion's irregular just war theory.     

Reduced insecticide susceptibility among populations of Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) in strawberry production

Chilli thrips, Scirtothrips dorsalis Hood (Thysanoptera: Thripidae) is a major, economically important, and recent invasive pest of strawberries and other horticultural crops in United States. Several conventional insecticides are used for S. dorsalis management, and resistance development threatens loss of few available tools. Hence, our objectives were to: (1) determine the susceptibility of S. dorsalis to commonly used conventional insecticides: spinetoram, acetamiprid, cyantraniliprole and bifenthrin, and (2) establish LC₅₀ and LC₉₀ dosages for spinetoram against S. dorsalis. Sampling of S. dorsalis populations was conducted twice in seven strawberry fields in Florida during the strawberry field season between 2019 and 2020. Leaf-disc bioassays were performed with field collected populations along with a susceptible 2-year-old laboratory culture of S. dorsalis. Overall, at highest recommended rate the percent mortality of late season S. dorsalis populations from five out of seven collection sites was lower (~41%) than average mortality observed with early season populations (~72%). Populations from at least four out of seven sampling sites exhibited significantly lower mortality than the laboratory susceptible culture in late season. The LC₅₀ and LC₉₀ values for spinetoram for the susceptible laboratory population were 0.026 and 8.64 ppm, respectively. On the other hand, LC₅₀ values of field collected populations to spinetoram varied with resistance ratios ranging from 6 to 269 fold as compared against the laboratory strain. Our results suggest that susceptibility of S. dorsalis to commonly used insecticides in strawberries varies significantly between early and late season populations within the same crop season. The efficacy of bifenthrin against S. dorsalis was particularly low (~ reduced to half in late season), especially among field collected populations. Our results indicate an urgent need to incorporate other pest management strategies, as well as effective rotation programs to reduce selection for resistance among populations of S. dorsalis in strawberry production.