Methylglyoxal-mediated growth inhibition in an Escherichia coli cAMP receptor protein mutant

Under certain growth conditions, some strains of Escherichia coli accumulate toxic levels of methylglyoxal. This report characterizes a strain which synthesizes a mutant cAMP receptor protein in an adenylate cyclase deletion background. When cultured in glucose 6-phosphate minimal medium, this strain (222) was prematurely growth arrested due to methylglyoxal production; growth inhibition did not occur when the strain was grown in glucose minimal medium. A comparison of a variety of enzyme and cofactor levels in the related strains 222 (mutant) and 225 (wild-type) grown on either glucose or glucose 6-phosphate medium was carried out. The only difference found that might explain an increase in methylglyoxal accumulation was an elevated level of phosphofructokinase in strain 222 grown on glucose 6-phosphate. Since this enzyme activity probably limits hexose phosphate metabolism, it is suggested that growth inhibition in strain 222 may be due to increased production of triose phosphate, some of which is converted to methylglyoxal.     

Effects of habitat loss and limitation on effective population size and inbreeding rates of Walia ibex (Capra walie) in Ethiopia

The effects of habitat loss and limitation on effective population size and inbreeding rates of Walia ibex (Capra walie) were assessed at Simien Mountains National Park. Total direct census was conducted in 2009. Historical data were obtained from park offices and literatures. Effective population sizes (N_e), inbreeding rates (ΔF) and heterozygosity losses to the whole and subdivided population per habitat were estimated. Correlations (r) between the two repeated direct censuses were positive (r = 0.99, P < 0.01). The mean N_e and ΔF (%/year) per study sites were 65.34 ± 59.45 and 0.0286 ± 0.032, respectively. The ΔF of the whole population of C. walie was 0.228 ± 0.011. The ΔF was negatively correlated with N_e (r = ?0.799, P < 0.05). The mean ΔF per fragmented habitat ranged from 0.3 (Cheneck) to 7.7% (Buait ras). The highest ΔFs per year were observed in Buait ras (7.7%), Adarmaz (7.4%) and Sankaber (4.5%). The mean heterozygosity loss per total population was 0.235 ± 0.42, which was about 23.5%. The differences in N_e and ΔF among the population per habitat were the results of habitat limitation, which in turn reduce the genetic variability and foster losses of heterozygosity.     

Species Diversity and Altitudinal Gradient Patterns of Evergreen Broad leaved Forest in MeihuashanNational Natural Reserve,Fujian Province

In China, evergreen broad leaved forests (EBLFs) is one of the most important vegetation types which was widly distributed in subtropical area, and it plays a very important role in the global biological diversity and natural environment conservation also. In order to reveal species diversity and altitudinal gradient patterns of evergreen broad leaved forest in Meihuashan National Natural Reserve, Fujian Province. Five altitude transects were set up at a vertical interval of 200m between 375m and 1300m above sea level in the EBLFs distribution areas, and twenty four quadrats(14400m2) had been surveyed. Species richness(S), species richness index (dGl), Simpson index (D), Shannon Wiener index (H′), Pielou evenness index (J) had been used for analysis of species diversity and altitudinal gradient pattern of EBLFs. The average value of S, dGl, H′,J and D were 64.42, 10.75, 5.75, 3.50, 0.58 respectively. The difference of community species diversity index(S, dGl, D, H′, and J) was extremely significant between transects, and the altitudinal gradient patterns of species diversity presented the unimodal variable trend, with a peak in the mid altitude(700m-900m). The species richness and Shannon Wiener index of different layer were ranked as shrub layer (include young tree and the plants between layers)>arbor layer>herb layer. The species richness of tree and shrub layer, and Shannon Wiener index of tree layer were significantly different between at transects, and trends of altitude gradient was similar to community. The Shannon Wiener index of shrub layer and herb layer, and the species richness of herb layer did not change significantly along elevation gradient. Therefore, plant species diversity distribution pattern presented a unimodal variable trend along an elevation gradient, and supported “mid domain model” in EBLFs of Meihuashan National Nature Reserve.     

西双版纳勐养自然保护区土地利用对自然景观的影响

使用ARC/INFO和ARC/VIEW地理信息系统,对以1995年3月的卫星影像图、相关图件及数据为基础的图形数据库进行分析,研究了土地利用对勐养自然保护区自然景观的影响.结果表明,土地利用使季节雨林生境的异质性最高(多样性指数H为2.1759,优势度指数D为1.2831),季风常绿阔叶林异质性最小(H为1.2531,D为2.3318).该保护区总的人为干扰强度指数(HD)为0.1287,其中季节雨林生境受干扰最强烈,HD达0.8809.季风常绿阔叶林是保护区的优势植被(占总面积的78%),土地利用使其约12.36%(或10895hm₂)的面积被损坏.热带雨林(季节雨林、山地雨林和季雨林,占总面积的12%)是重点保护对象,土地利用使其损失了约19%(2557hm₂),是受到严重干扰的生境组分.耕地的斑块数量最多(占斑块总数的25.86%)而面积却很小(占总面积的2.2%),呈小块状散布在保护区里.人们因经营耕地而活动在保护区里,构成了大面积的干扰,使灌丛草地基本随着耕地散布在保护区里.要保护好西双版纳勐养自然保护区,必须以改善土地利用方式来控制耕地的扩散.     

Ability of the endangered species Papaver fauriei to produce hybrids with a cultivated poppy (Papaver sp.)

Papaver fauriei is an endemic and endangered species that grows only on the gravelly alpine slopes of Mt. Rishiri, Japan. Cultivated poppy (Papaver sp.), the species name of which is unknown, has been introduced to the natural habitats of P. fauriei through human activities. Because the appearance and internal transcribed spacer (ITS) sequences of these two poppies are highly similar, it is of concern that they could produce hybrids in their natural habitats. Thus, first, the ability of these two poppies to produce hybrids was analyzed by artificial fertilization in this study. A large number of seeds were produced by reciprocal crosses between P. fauriei and the cultivated poppy, comparable with the number of seeds obtained by self‐ or cross‐fertilization of P. fauriei or the cultivated poppy. In addition, high germination was observed for seeds obtained from crosses between the two poppies, and deleterious phenotypes, such as albinism and dwarfism, were not detected in the F₁ generation. These results indicate that after pollination, there is no reproductive isolation between the two poppies. Second, we sequenced the internal transcribed spacer (ITS) region of 240 poppy individuals collected from the gravelly alpine slopes of Mt. Rishiri, and 66 showed the sequence of P. fauriei, whereas 174 showed the sequence of the cultivated poppy. However, the ITS sequence that confirms hybridism between the two poppies was not detected in these individuals, indicating that hybridization of P. fauriei and the cultivated poppy rarely occurs under natural conditions. Unknown mechanism(s) appear to prevent cross‐pollination between the two poppies.     

鄂西南后河自然保护区植物区系研究

后河自然保护区共人维管植物１４１６种,尿属５６８属１６０科。其中蕨类、拟蕨类４１种２８属２０科;裸子植物１８种１１属６科;被子植物１３５７种５２９属１３４科。在科、属、种不同水平上对后河自然保护区植物区系特点进行了较深入的统计和分析。结果显示了该区系的丰富性。复杂性。古老、遗、原始性、温带成分的集中性,古特珍稀危植物群落繁荣的特殊性等特点。因此有理由认为后河植物区系对湖北乃至华中植物区系具有典型的     

The ecology of a beech forest on Mt. Sanpoiwadake,Hakusan National Park,Japan I. Braun-Blanquet,TWINSPAN and DCA analysis

The Lindero membranaceae-Fagetum crenatae association on Mt. Sanpoiwadake, Hakusan National Park, Japan, has been classified using traditional Braun-Blanquet methods. The association was floristically sub-divided into six communities, all of which had been included as four subassociations by Hukusima (1982). The resulting table was compared with an analogous community table derived using computer-based TWINSPAN analysis. This dual approach was shown to provide a fully objective classification by method, the subjective element in the Braun-Blanquet method thus being substantiated TWINSPAN. Subsequent ordination of the data using DCA then provided a further degree of objective evaluation allowing any misclassified stand or species to be re-examined, and at the same time displaying the detailed inter-relationships between all species or stands.     

Incidence and mortality of pancreatic cancer on a rapid rise in Taiwan, 1999–2012

BackgroundAccumulating data has revealed a rapidly rising incidence of pancreatic cancer in Western countries, but convincing evidence from the East remains sparse. We aimed to quantify how the incidence and mortality rates of pancreatic malignancy changed over time in Taiwan, and to develop future projection for the next decade.MethodsThis nationwide population-based study analyzed the Taiwan National Cancer Registry and the National Cause of Death Registry to calculate the annual incidence and mortality rates of pancreatic malignancy from 1999 to 2012 in this country. The secular trend of the incidence was also examined by data from the National Health Insurance Research Database.ResultsA total of 21,986 incident cases of pancreatic cancer and 20,720 related deaths occurred during the study period. The age-standardized incidence rate increased from 3.7 per 100,000 in 1999 to 5.0 per 100,000 in 2012, with a significant rising trend (P < 0.01). The increase was nationwide, consistently across subgroups stratified by age, gender, geographic region, and urbanization. Data from the National Health Insurance Research Database corroborated the rise of incident pancreatic cancer. Mortality also increased with time, with the age-standardized rate rising from 3.5 per 100,000 in 1999 to 4.1 per 100,000 in 2012 (P < 0.01). In accordance with the incidence, the mortality trend was consistent in all subgroups. Both the incidence and mortality were projected to further increase by approximately 20% from 2012 to 2027.ConclusionThe incidence and mortality of pancreatic cancer have been rapidly rising and presumably will continue to rise in Taiwan.     

Seismic Survey Design and Effects on Maternal Polar Bear Dens

Large-scale industrial activities can have negative effects on wildlife populations. Some of these effects, however, could be reduced with effective planning prior to development. The Coastal Plain of the Arctic National Wildlife Refuge, in northeastern Alaska, USA, is an important maternal denning area for polar bears (Ursus maritimus). Recent legislation has opened the area for potential oil and gas development. As a result, there is interest in conducting winter seismic surveys across the area that could disturb denning female polar bears and lead to decreased cub survival. We sought to demonstrate how different seismic survey designs, with and without aerial den detection surveys, could affect the level of potential effect on denning polar bears during spring (Feb–Apr). We developed 5 hypothetical seismic survey designs for a portion of the Coastal Plain ranging from no spatial or temporal restrictions on activities to explicit consideration of when and where operations can occur. We evaluated how many dens might be disturbed by seismic surveys and the average distance activity came within simulated polar bear dens. Survey design had a large effect on the estimated number of dens that could be disturbed; the scenario with the highest spatial and temporal specificity reduced the number of dens disturbed by >90% compared to the scenario with no restrictions on when and where activity could occur. The use of an aerial den detection survey prior to seismic activity further reduced the number of dens disturbed by 68% across all scenarios. The scenario with the highest spatial and temporal specificity always had the lowest level of disturbance for all scenarios with and without the aerial survey included. Our study suggests that large reductions in the probability of disturbance can occur through careful planning on the timing and distribution of proposed activities even when surveys are planned in areas with a high density of polar bear dens. Published 2019. This article is a U.S. Government work and is in the public domain in the USA. The Journal of Wildlife Management published by Wiley Periodicals, Inc. on behalf of The Wildlife Society.     

Changes in colorectal cancer treatment during the COVID-19 pandemic in Japan: Interrupted time-series analysis using the National Database of Japan

BackgroundThe coronavirus disease 2019 (COVID-19) pandemic forced us to accept changes in our usual diagnostic procedures and treatments for colorectal cancer. This study aimed to determine the impact of the pandemic on colorectal cancer treatment in Japan.MethodsThe number of colorectal surgeries, stoma constructions, stent placements or long tube insertions, and neoadjuvant chemoradiotherapies were determined each month using sampling datasets from the National Database of Health Insurance Claims and Specific Health Checkups of Japan. The observation periods before and during the pandemic were January 2015 to January 2020 and April 2020 to January 2021, respectively. An interrupted time-series analysis was used to estimate the changes in the number of procedures during the pandemic.ResultsThe number of endoscopic surgeries for colon cancer significantly decreased in April and July 2020 and for rectal cancer in April 2020. Additionally, the number of laparoscopic and open surgeries for colon cancer significantly decreased in July 2020 and October 2020, respectively. The number of stoma constructions and stent placements or long tube insertions did not increase during the observation period. Neoadjuvant chemoradiotherapy for rectal cancer significantly increased in April 2020 but levels returned shortly thereafter. These results suggest that the recommendations to overcome the pandemic proposed by expert committees, including the replacement of laparoscopic surgery with open surgery, stoma construction to avoid anastomotic leak, and replacement of surgery on the ileus with stent placement, were not widely implemented in Japan. However, as an exception, neoadjuvant chemoradiotherapy for rectal cancer was performed as an alternative treatment to delay surgery in small quantities.ConclusionA declining number of surgeries raises concerns about cancer stage progression; however, we found no evidence to suggest cancer progression from the trajectory of the number of stoma constructions and stent placements. In Japan, even during the pandemic, conventional treatments were performed.