Species identification and tree-ring dating of wood boxes excavated from the Shinan shipwreck,Korea

The Shinan shipwreck, which was excavated in the southwestern sea of Korea in the 1970s, was a Chinese trade ship from the Yuan Dynasty, traveling from China to Japan in the early 14th century (A.D. 1323). Anatomical examination indicated that the wood boxes carrying thousands of Chinese porcelain pieces on the Shinan shipwreck were made of either Cryptomeria japonica or Cunninghamia spp. The former grows in South China and Japan, and the latter in China and Taiwan. Therefore, we could not confine the origin of the wood to a single country by wood identification. However, we could date 21 wood boxes using tree-ring chronologies of C. japonica from western Japan. The outermost ring with sapwood was dated to A.D. 1316. The results from the tree-ring dating indicated that the wood boxes on the Shinan shipwreck were of Japanese rather than Chinese origin.     

Climate change and livestock parasites: integrated management of sheep blowfly strike in a warmer environment

The incidence of parasite‐mediated livestock disease is the result of a complex interaction of factors such as parasite and host abundance, host susceptibility, climate and, critically, farmer husbandry and intervention strategies, all of which change seasonally in space and time. Given the complexity of the interacting factors, the effects of environment changes on disease incidence are hard to predict, as accordingly are the optimal husbandry responses required to ameliorate any effects. Here a model system is used to explore these issues. Cutaneous myiasis (blowfly strike) is common disease of livestock and would be expected to be highly sensitive to even small changes in climate; it provides a good model for highlighting the problems inherent in attempting to predict the effect of climate change on livestock disease incidence. For this, a stochastic simulation model is used to examine the changes in the seasonal incidence of ovine cutaneous myiasis on farms in the United Kingdom and the likely effects of changes in husbandry and control strategies. The simulations show that the range of elevated temperatures predicted by current climate change scenarios result in an elongated blowfly season with earlier spring emergence and a higher cumulative incidence of strike. Overall, higher temperatures increased strike incidence disproportionately in ewes in early summer, but had relatively less direct effect on the pattern of lamb strike incidence; a +3 °C increase in average temperature approximately doubles the cumulative incidence of strike in lambs but results in four times more strikes in ewes. A range of strike management options is examined and the models show that changes in husbandry practices are also likely to have an important effect in reducing early season ewe strike incidences. The simulations suggest that integrated changes in husbandry practices are likely to be able to manage expected increases in strike, given the range of climate changes currently predicted.     

Evidence that ship noise increases stress in right whales

Baleen whales (Mysticeti) communicate using low-frequency acoustic signals. These long-wavelength sounds can be detected over hundreds of kilometres, potentially allowing contact over large distances. Low-frequency noise from large ships (20-200 Hz) overlaps acoustic signals used by baleen whales, and increased levels of underwater noise have been documented in areas with high shipping traffic. Reported responses of whales to increased noise include: habitat displacement, behavioural changes and alterations in the intensity, frequency and intervals of calls. However, it has been unclear whether exposure to noise results in physiological responses that may lead to significant consequences for individuals or populations. Here, we show that reduced ship traffic in the Bay of Fundy, Canada, following the events of 11 September 2001, resulted in a 6 dB decrease in underwater noise with a significant reduction below 150 Hz. This noise reduction was associated with decreased baseline levels of stress-related faecal hormone metabolites (glucocorticoids) in North Atlantic right whales (Eubalaena glacialis). This is the first evidence that exposure to low-frequency ship noise may be associated with chronic stress in whales, and has implications for all baleen whales in heavy ship traffic areas, and for recovery of this endangered right whale population.     

What is natural? The scale of cryptogenesis in the North Atlantic Ocean

Aim Cryptogenic species may include those taxa that were historically introduced and are now falsely viewed as native. Investigated here is the scale of cryptogenesis in the North Atlantic Ocean by examining disjunct distributions, defined as temperate species occurring only on both sides of the North Atlantic. Disjunct distributions can be explained by four scenarios: glacial relicts, taxonomic artefacts, natural trans‐oceanic dispersal and human‐mediated introduction. Location North Atlantic Ocean. Methods Model taxa included ascidians, bivalves and hydrozoans. Biogeographic status (native, introduced or cryptogenic) was assigned to all species exhibiting a disjunct distribution, based upon multiple criteria. Results Of 1030 species, 60 have a strictly disjunct distribution. Of these disjunct species, for five species there is no reason to doubt their native status, and 55 species are cryptogenic or introduced. Groups with high relative dispersal capacities do not have disjunct distributions more often. Infaunal bivalves have the lowest relative number of disjunct species; none are cryptogenic or naturally disjunct. This supports the concept that glaciations are unlikely to cause disjunct distributions: there are no studies that provide conclusive evidence for the glacial relict model. Hydrozoa have the highest relative number of disjunct species, which, while historically explained by undocumented rafting, may more likely be the result of dispersal by ships, which travel relatively fast, are independent of currents and provide greater surface area. Main conclusions This reanalysis of the historical biogeography of the North Atlantic marine biota reveals that far more species may have been introduced than previously recognized, potentially significantly altering our fundamental understanding of community evolution and ecology. Species that have been present for centuries and can be important ecological engineers who have shaped contemporary communities are possibly falsely viewed as native: they may in fact be the unrecognized introductions of historical times.     

A comparative study of the mechanics of the pectoralis muscle of the red‐tailed hawk and the barred owl

A comparison of the isometric forces and levers of the pectoralis muscle in red‐tailed hawks (Buteo jamaicensis) and barred owls (Strix varia) was done to identify differences that may correlate with their different flight styles. The pectoralis consists of two heads, the anterior m. sternobrachialis (SB) and the posterior m. thoracobrachialis (TB). These are joined at an intramuscular tendon and are supplied by separate primary nerve branches. As in other birds, the two heads have distinct fiber orientations in red‐tailed hawks and barred owls. SB's fiber orientation (posterolateral and mediolateral from origin to insertion) provides pronation and protraction of the humerus during adduction. Electromyographic studies in pigeons show that it is active in early downstroke and during level flight. TB is more active during take‐off and landing in pigeons. The anterolateral orientation (from origin to insertion) of its fibers provides a retractive component to humeral adduction used to control the wing during landing. In our study, the maximum isometric force produced by the combined pectoralis heads did not differ significantly between the hawk and owl, however, the forces were distributed differently between the two muscle heads. In the owl, SB and TB were capable of producing equal amounts of force, but in the hawk, SB produced significantly less force than did TB. This may reflect the need for a large TB to control landing in both birds during prey‐strike, with the owl maintaining both protractive (using SB) and retractive (using TB) abilities. Pronation and protraction may be less important in the flight behavior of the hawk, but its prey‐strike behavior may require the maintenance of a substantial TB for braking and controlled stalling, as it initiates strike behavior. J. Morphol. 2012. © 2011 Wiley Periodicals, Inc.     

Actual and perceived collision risk for bird strikes at Namibian airports

At Namibia’s two major airports, Hosea Kutako International and Eros (domestic), 117 bird strike collision incidents were recorded between 2006 and 2010. A risk assessment, which included a proposed risk weighting methodology, was conducted at Hosea Kutako and Eros airports, which estimated the probability of an accident/collision as well as the consequence of such a collision. The assessment included surveys of bird occurrence frequencies as well as pilot interviews. The results of the risk assessments were compared with actual bird strike incidences for each species, frequency of occurrence of birds and pilot perceptions of species risk, in order to find whether risk assessment and pilot perception are reliable measures of potential bird strike incidence. White-backed Vulture Gyps africanus and Helmeted Guineafowl Numida meleagris were the highest risk species at both airports. They were also, after Crowned Lapwing Vanellus coronatus, the species most often observed by pilots. Bird strike records showed that Crowned Lapwing and Helmeted Guineafowl were also the most frequently struck birds at both airports. The study illustrates how combining risk assessment, pilot perception and bird strike history can benefit bird strike minimisation plans at airports through the rapid identification of priority bird species.     

酚类抑制剂抗5-脂氧合酶的分子对接研究

目的:研究抗5-脂氧合酶酚类抑制剂的结构活性关系及作用机制。方法:构建7个抗5-脂氧合酶阳性酚类抑制剂分子库,利用Autodock 4.2和iGEMDOCK 2.1软件包对受体与抑制剂进行模拟对接研究并计算结合自由能。结果:用Autodock 4.2、iGEMDOCK 2.1计算得到的结合自由能与抑制剂的抑制活性之间都存在良好的相关性,它们的决定系数(R2)依次为0.856 64和0.784 41,标准误差(SD)分别为0.430 92和5.323 35,P值分别为0.002 79和0.007 98;配体与受体之间形成的氢键在决定配体在受体活性部位的构象及定位中起重要作用,但两者结合的主要驱动力为范德华作用力;具有碳氧双键及与该双键共轭的碳碳双键的多环酚类化合物有较强的抗5-脂氧合酶活性。结论:Autodock 4.2比iGEMDOCK 2.1预测抗5-脂氧合酶酚类抑制剂的能力强;具有碳氧双键及与该双键共轭的碳碳双键的多环酚类化合物有较强的抗5-脂氧合酶活性。     

Pre-adult mortality in the blowfly Lucilia sericata

Populations of the blowfly, Lucilia sericata (Meigen) (Diptera: Calliphoridae), have a considerable potential for rapid increase; the lifetime reproductive output of each adult female has been estimated to be between 130 and 172 eggs. Nevertheless, in the field, absolute population densities of this species are relatively low. To account for this difference, the levels of mortality affecting the eggs, feeding and wandering larvae and pupae of L. sericata were assessed in the field and laboratory. Percentage egg hatch was dependent on relative humidity with no egg eclosion at humidities below 50%; there was no significant effect of temperature on egg hatch. On infested sheep, the mean mortality of feeding larvae was 53%, but this ranged widely from 0% to 96%. There was no effect of atmospheric temperature or humidity on the mortality of feeding larvae in vivo. In the laboratory, only 10% of wandering larvae pupariated at 10 degrees C. At above 20 degrees C pupariation was consistently almost 100%. Percentage emergence increased from 0% at 10 degrees C to about 80% between 20 and 30 degrees C. The upper lethal temperature for pupae was approached at 35 degrees C. Analysis of the predation of pupae in the field revealed a weak, but significant curvilinear relationship between temperature and proportionate mortality and a median mortality of 0.49% per 24 h exposure (interquartile range = 5.2%). There was no evidence of density dependence in pupal predation. Overall, it is estimated that pre-adult mortality accounts for losses of approximately 97% of each generation, but this figure is subject to considerable variation depending on factors such as climate, time of year and host susceptibility.     

Ultrasound elastographic assessment of plantar fascia in runners using rearfoot strike and forefoot strike

Forefoot strike is increasingly being adopted by runners because it can better attenuate impact than rearfoot strike. However, forefoot strike may overload the plantar fascia and alter the plantar fascia elasticity. This study aimed to use ultrasound elastography to investigate and compare shear wave elasticity of the plantar fascia between rearfoot strikers and forefoot strikers. A total of 35 participants (21 rearfoot strikers and 14 forefoot strikers), who were free of lower limb injuries and diseases, were recruited from a local running club. Individual foot strike patterns were identified through the measured plantar pressure during treadmill running. The B-Mode ultrasound images and shear wave elastographic images of the plantar fascia were collected from each runner. Two independent investigators reviewed the images and examined the plantar fascia qualitatively and quantitatively. The results demonstrated an overall good agreement between the investigators in the image review outcomes (ICC:0.96–0.98, κ: 0.89). There were no significant differences in the fascial thickness (p = 0.50) and hypoechogenicity on the gray-scale images (p = 0.54) between the two groups. Shear wave elastography showed that forefoot strikers exhibited reduced plantar fascia elasticity compared to rearfoot strikers (p = 0.01, Cohen’s d = 0.91). A less elastic fascial tissue was more easily strained under loading. Tissue overstrain is frequently related to the incidence of plantar fasciitis. While further study is needed for firm conclusions, runners using forefoot strike were encouraged to enhance their foot strength for better protection of the plantar fascia.