KATP通道基因在大鼠组织中的表达

为检测大鼠肺动脉平滑肌及支气管平滑肌中KATP．通道亚基的表达情况,应用RT-PCR技术．从原代培养的Wistar大鼠肺动脉平滑肌及支气管平滑肌细胞第3—5代提取总RNA,逆转录．并进行PCR扩增鉴定．发现肺动脉平滑肌细胞有Kir6.1、SUR1和SUR2B的表达,其中SUR1表达量较弱,支气管平滑肌细胞有Kir6.1和SUR2B的表达。     

连作对丹参生长的障碍效应

通过对1～4年不同连作年限地块丹参生长发育情况进行的连续调查分析,结果表明,连作严重危害丹参生长,主要表现在6～9月,丹参生长期的枯苗率大幅度上升,地上、地下部生长量下降,根系数量、直径和长度减小,产世降低。同时由于有效成分含量降低,根系外观畸形,造成商品率下降,从而影响丹参质量。通过对土壤pH测定发现．丹参连作障碍可能与土壤酸性增加有关。     

High‐Sensitivity C‐Reactive Protein in Japanese Patients with Type 2 Diabetes

Objective: To assess the relationship between high‐sensitivity (HS) C‐reactive protein (CRP) and metabolic syndrome (MetS) or atherosclerosis and to assess effects of strict metabolic control on the degree of inflammation and MetS in patients with type 2 diabetes. Research Methods and Procedures: Four hundred thirteen patients with diabetes were enrolled in the cross‐sectional study. Of these 413 patients, 161 patients were further admitted for 2.4 ± 0.4 weeks (mean ± SD) to investigate the change in HS‐CRP or other parameters under strict metabolic control. Results: Log‐transformed HS‐CRP value (log HS‐CRP) was strongly correlated with BMI (r = 0.448, p < 0.01). Log HS‐CRP was also correlated with the presence of MetS or each component of MetS. Furthermore, a positive significant trend in HS‐CRP levels was shown with an increasing number of MetS components (p < 0.05). Log HS‐CRP showed a significant positive correlation with carotid artery intima‐media thickness (IMT) (r = 0.152, p < 0.01). In multiple step‐wise regression analysis, BMI, hemoglobin A_1c, right IMT, duration of diabetes, and triglyceride were selected as explanatory variables for log HS‐CRP (R² = 0.412). Under strict metabolic control, HS‐CRP was significantly (p < 0.01) lower, together with lower levels of other markers for MetS. The change in HS‐CRP was significantly correlated with the change in BMI (r = 0.161, p = 0.04). Discussion: In subjects with type 2 diabetes, HS‐CRP levels are related to MetS and subclinical atherosclerosis. Strict weight management and metabolic control were associated with a reduction in HS‐CRP levels, and changes in HS‐CRP were related to changes in weight, supporting the hypothesis that lifestyle modification reduces inflammation and the risk of CHD.     

Change in Vascular Adhesion Protein‐1 and Metabolic Phenotypes after Vertical Banded Gastroplasty for Morbid Obesity

Objective: The association between circulating vascular adhesion protein‐1 (VAP‐1) and metabolic phenotypes has been shown to be inconsistent. The current study explored whether the changes in serum VAP‐1 levels correlate with the changes in metabolic phenotypes after weight reduction surgery. Research Methods and Procedures: Clinical characteristics and serum VAP‐1 levels in 20 morbidly obese subjects (mean BMI 38.84 kg/m²) were measured before and after vertical banded gastroplasty. Results: Before surgery, serum VAP‐1 levels correlated positively with fasting plasma glucose (γ = 0.56, p = 0.01) and negatively with insulin levels (γ = ?0.51, p = 0.021). After surgery, the changes in serum VAP‐1 levels were negatively correlated with the changes in waist circumference (γ = ?0.57, p = 0.011), diastolic blood pressure (DBP) (γ = ?0.56, p = 0.015), and mean arterial pressure (γ = ?0.46, p = 0.055). In multivariate regression, serum VAP‐1 levels were negatively correlated with waist circumference (β = ?2.36, p = 0.014) and DBP (β = ?3.02, p = 0.017) after adjusting for age and gender. The change in DBP was negatively correlated with the change in VAP‐1 levels after adjusting for age, gender, and steady‐state plasma glucose. Discussion: The results suggest that VAP‐1 levels are correlated with fasting glucose and insulin levels in morbidly obese subjects. After surgery, the changes in VAP‐1 levels were associated with changes in visceral adiposity and DBP. Serum VAP‐1 might modulate DBP independently from the changes in insulin resistance in morbidly obese people.     

Niche-based modelling as a tool for predicting the risk of alien plant invasions at a global scale

Predicting the probability of successful establishment of plant species by matching climatic variables has considerable potential for incorporation in early warning systems for the management of biological invasions. We select South Africa as a model source area of invasions worldwide because it is an important exporter of plant species to other parts of the world because of the huge international demand for indigenous flora from this biodiversity hotspot. We first mapped the five ecoregions that occur both in South Africa and other parts of the world, but the very coarse definition of the ecoregions led to unreliable results in terms of predicting invasible areas. We then determined the bioclimatic features of South Africa's major terrestrial biomes and projected the potential distribution of analogous areas throughout the world. This approach is much more powerful, but depends strongly on how particular biomes are defined in donor countries. Finally, we developed bioclimatic niche models for 96 plant taxa (species and subspecies) endemic to South Africa and invasive elsewhere, and projected these globally after successfully evaluating model projections specifically for three well‐known invasive species (Carpobrotus edulis, Senecio glastifolius, Vellereophyton dealbatum) in different target areas. Cumulative probabilities of climatic suitability show that high‐risk regions are spatially limited globally but that these closely match hotspots of plant biodiversity. These probabilities are significantly correlated with the number of recorded invasive species from South Africa in natural areas, emphasizing the pivotal role of climate in defining invasion potential. Accounting for potential transfer vectors (trade and tourism) significantly adds to the explanatory power of climate suitability as an index of invasibility. The close match that we found between the climatic component of the ecological habitat suitability and the current pattern of occurrence of South Africa alien species in other parts of the world is encouraging. If species' distribution data in the donor country are available, climatic niche modelling offers a powerful tool for efficient and unbiased first‐step screening. Given that eradication of an established invasive species is extremely difficult and expensive, areas identified as potential new sites should be monitored and quarantine measures should be adopted.     

The Distribution of Grazing Pressure in Relation to Vegetation Resources in Semi-arid West Africa: The Role of Herding

In semi-arid West Africa, livestock are increasingly managed by sedentary producers in close proximity to expanding cropped lands. To evaluate the agricultural and environmental implications of this trend, a study was conducted to investigate the effect of grazing management on the spatial distribution of grazing pressure, the forage provided animals during the grazing period, and local herd-forage ratios across three agropastoral landscapes characterized by varying cultivation pressure. During the 19-month study period, data on herbaceous vegetation, livestock populations, and grazing itineraries were collected. These data were referenced to land units averaging 70 ha in area. Using this approach, each of 3,819 grazing itineraries was characterized as to: 1. the sum of the products of the palatable forage mass of a particular land unit and the time spent grazing by the herd within that unit (FAT, expressed in kg-hours ha⁻¹); and 2. the average palatable herbaceous forage mass encountered by livestock across the itinerary weighted by the time spent in the land units crossed (FA, expressed in kg ha⁻¹). The spatial dispersion of livestock grazing around human settlements was found to decline with a reduction in herding labor investment (herded>herd-release>free pasture). Multiple regression analyses of itinerary data demonstrate that both FAT and FA also decline with a reduction in herding labor investment. Herded and herd-release managed livestock were offered more palatable forage and grazed areas of higher forage availability than free-pastured animals. This supports arguments that as the investment of time and effort into herding declines, feed supply to livestock will decline and the potential for grazing-induced environmental change will increase.     

The secret life of the giant Australian cuttlefish Sepia apama (Cephalopoda): Behaviour and energetics in nature revealed through radio acoustic positioning and telemetry (RAPT)

Sepia apama were tagged with acoustic transmitters and monitored on their native House Reef, Boston Bay, South Australia, with a radio acoustic positioning telemetry (RAPT) system. Cuttlefish were tagged with position-only and intra-mantle jet pressure transmitters. New data analyses were developed to handle problem data that arise with an uneven reef environment. Maximum range for the cuttlefish varied from 90 m to 550 m. Cuttlefish home range was between 5300 m² and 23,700 m². S. apama were found to be diurnal as average distance travelled was higher in the day than at night, and cuttlefish were active for 32 days, but only 18 nights. After the cuttlefish settled into reef crevices, activity spectrum and positioning analysis showed foraging behaviour at only 3.7% per day and 2.1% per night. Cuttlefish were found to spend more than 95% of the day resting, which suggests that their bioenergetics are more akin to those of octopus than of squid. The cuttlefish combination of predator avoidance, efficient foraging and quiescent lifestyle allows energy to be channelled into growth and fulfillment of the live-fast-die-young cephalopod philosophy.     

Alfred Russel Wallace, past and future

The naturalist Alfred Russel Wallace (1823–1913) has for many years been standing in the shadow of his more famed co‐discoverer of the principle of natural selection, Charles Darwin. Despite outward similarities between the two men's formulation of the principle, Wallace had fit his appreciation of natural selection into views on evolution that were quite different from Darwin's. A closer examination of what Wallace had in mind suggests a model of process in which natural selection per se acts as the negative feedback mechanism (actually, a ‘state‐space’) in the relation between population and environment, and environmental engagement as made possible by the resulting selection of traits acts as the positive feedback part of the cycle. Thus, it may be better to contextualize adaptive structures as entropy‐relaying biogeochemical facilitators that only ‘generate a potential for evolution’ than to portray them as the end results of evolution. This systems point of view better lends itself to appreciations of the biogeographical context of evolution than does the tree‐thinking of a more conventional style of speciation‐focused Darwinism, which sometimes confuses process with result.     

Seed yield of soybeans with daytime or continuous elevation of carbon dioxide under field conditions

Some studies of responses of plants to elevated concentrations of carbon dioxide (EC) added CO₂ only in the daytime, while others supplied CO₂ continuously. I tested whether these two methods of EC treatments produced differences in the seed yield of soybeans. Tests were conducted for four growing seasons, using open top chambers, with soybeans rooted in the ground in field plots. One third of the chambers were flushed with air at the current ambient [CO₂] (AC), one third had [CO₂] 350 μmol mol⁻¹ above ambient during the daytime (EC_d), while one third had [CO₂] 350 μmol mol⁻¹ above ambient for 24 h per day (EC_dn). EC_dn increased seed yield by an average of 62 % over the four years compared with the AC treatment, while EC_d increased seed yield by 34 %. Higher seed yield for EC_dn compared with EC_d occurred each year. In comparing years, the relative yield disadvantage of EC_d decreased with increasing overall seed yield. On days with high water vapor pressure deficits, soybean canopies with EC_d had smaller midday extinction coefficients for photosynthetically active radiation than canopies with EC_dn, because of a more vertical leaf orientation. Hence the seed yield of soybean at EC varied depending on whether EC was also provided at night, with much greater yield stimulation for EC_dn than for EC_d in some years.