国际水稻研究所中期规划(2002-2004年)(接上期)

8　项目 8 :雨育低地和旱地水稻生态系统的自然资源管理8 1　基本原理雨育低地和旱地水稻生态系统与其在地形系列中的位置有关 ,并根据水制度状况加以界定。低地包括易旱易涝等两种生态系统。可能会形成水塘和出现土壤被淹现象 ,虽然可以选择旱播方法 ,但是通常采用最多的还是移栽的方法。旱地土壤在整个季节保持通气状态 ,种稻采用旱播的方法。土壤条件和作物形成方法对作物营养供应与管理、杂草竞争、土壤水分的抽出和水稻植株健壮成长所需要采用的相应方法有着巨大影响。水的多寡经常是水稻高产、稳产的主要限制因素。水的多寡在时间、周…     

One-third of reef-building corals face elevated extinction risk from climate change and local impacts

The conservation status of 845 zooxanthellate reef-building coral species was assessed by using International Union for Conservation of Nature Red List Criteria. Of the 704 species that could be assigned conservation status, 32.8% are in categories with elevated risk of extinction. Declines in abundance are associated with bleaching and diseases driven by elevated sea surface temperatures, with extinction risk further exacerbated by local-scale anthropogenic disturbances. The proportion of corals threatened with extinction has increased dramatically in recent decades and exceeds that of most terrestrial groups. The Caribbean has the largest proportion of corals in high extinction risk categories, whereas the Coral Triangle (western Pacific) has the highest proportion of species in all categories of elevated extinction risk. Our results emphasize the widespread plight of coral reefs and the urgent need to enact conservation measures.     

Use of ionic liquids for pi-conjugated polymer electrochemical devices

pi-Conjugated polymers that are electrochemically cycled in ionic liquids have enhanced lifetimes without failure (up to 1 million cycles) and fast cycle switching speeds (100 ms). We report results for electrochemical mechanical actuators, electrochromic windows, and numeric displays made from three types of pi-conjugated polymers: polyaniline, polypyrrole, and polythiophene. Experiments were performed under ambient conditions, yet the polymers showed negligible loss in electroactivity. These performance advantages were obtained by using environmentally stable, room-temperature ionic liquids composed of 1-butyl-3-methyl imidazolium cations together with anions such as tetrafluoroborate or hexafluorophosphate.     

Cataracts in the Bichon Frise

Purpose To determine the clinical characteristics of possible inherited cataract in the Bichon Frise breed. These characteristics include the relative frequency, gender effects, site of first cataract formation, age of onset, relationship of age to cataract maturity, and other concurrent pre‐ and postoperative ophthalmic diseases. Methods Four different populations of Bichon Frise were examined. They included: (1) referred patients of the University of Florida (VMTH; 1990–2000); (2) patients from other universities and large institutions (VMDB; 1970–2000); (3) patients from the Canine Eye Registry Foundation (CERF; 1970–2000); and (4) special patients recruited from eye clinics and ACVO specialty practices (1995–2001). Blood samples were obtained from many patients for future DNA analyzes. Statistical comparisons between groups were by general linear and anova analyzes, and P < 0.05 was considered significant. Results The four populations of cataractous and total Bichon Frise dogs included: (1) UF‐VMTH: 57 cataractous dogs; (2) VMDB: 406 dogs (28%) with cataracts; total dogs ? 1407; (3) CERF: 505 cataractous dogs (6%); total dogs ? 8222; and (4) ACVO: 223 cataractous dogs (57%); total dogs ? 391. In each population group, gender did not affect cataract distribution. Dogs between 2 and 8 years of age were most frequently affected, and initial cataract involvement affected equally the anterior and posterior cortices. Immature cataracts occurred more often in younger dogs, and hypermature cataracts were more frequently diagnosed in older dogs. Dogs with early cataracts were encountered more frequently in the CERF population. Pre‐ and postoperative retinal detachments (RD) were not infrequently diagnosed in the UF‐VMTH and VMDB groups. RD in the UF‐VMTH and VMDB groups occurred in 33% and 13% of the patients, respectively. Conclusions Cataracts were first encountered in CERF and VMDB data between 1975 and 1979 and have increased since this time. As expected, both similarities and differences between the four different populations of Bichon Frise were encountered. Both sexes of dogs are equally affected. The anterior and posterior cortical areas of the lens were first involved and dogs 2–8 years of age are most frequently affected. Cataracts affected younger dogs in the CERF group and older cataractous dogs in the other populations. Cataract formation appears to be inherited in the Bichon Frise dog. The frequency of pre‐ and postoperative retinal detachments present higher risks for cataract surgery in this breed.     

Velocity of spread of wheat stripe rust epidemics

ABSTRACT Controversy has long existed over whether plant disease epidemics spread with constant or with increasing velocity. We conducted largescale field experiments with wheat stripe rust at Madras and Hermiston, Oregon, where natural stripe rust epidemics were rare, to test these competing models. Data from three location-years were available for analysis. A susceptible winter wheat cultivar was planted in pure stand and also in a 1:4 or 1:1 mixture with a cultivar immune to the stripe rust race utilized in the experiments. Plots were 6.1 m wide and varied from 73 to 171 m in length. A 1.5 by 1.5-m focus was inoculated in either the center (2001) or upwind of the center (2002 and 2003) of each plot. Disease severity was evaluated weekly throughout the epidemics in each plot at the same points along a transect running upwind and downwind from the focus. Velocity of spread was calculated from the severity data and regressed separately on time and on distance from the focus. In all location-years and treatments, and at all levels of disease severity, velocity consistently increased linearly with distance, at an average rate of 0.59 m/week per m, and exponentially with time. Further, across epidemics there was a significant positive relationship between the apparent infection rate, r, and the rate of velocity increase in both space and time. These findings have important implications for plant diseases with a focal or partially focal character, and in particular for the effectiveness of ratereducing disease management strategies at different spatial scales.     

Age-related differences in parameters of feline immune status

In order to assess age-related differences in feline immune status, 101 domestic short haired cats were assigned to two groups, adult (2-5 years, n=50) and senior (10-14 years, n=51). Analyses of leucocyte populations, lymphocyte subsets, complement activity, serum immunoglobulins and acute-phase proteins were undertaken and revealed significant differences between the two groups. The senior group had significantly lower WBC, lymphocyte and eosinophil counts than the adult group. Neutrophil, monocyte and basophil counts did not differ between the groups. Flow cytometry analysis, in combination with differential WBC data, revealed that the absolute values (cells/l) of T-cells, B-cells and natural killer (NK) cells were significantly lower in the older animals. While serum immunoglobulins IgA and IgM were higher in the senior group when compared with the adult group, no significant differences were observed in complement activity or in serum acute-phase proteins. Our findings suggest that age-related changes to parameters of immune status in the feline model are likely to follow a similar pattern to those observed in other long-lived mammalian species.