Satellite remote sensing,biodiversity research and conservation of the future

Assessing and predicting ecosystem responses to global environmental change and its impacts on human well-being are high priority targets for the scientific community. The potential for synergies between remote sensing science and ecology, especially satellite remote sensing and conservation biology, has been highlighted by many in the past. Yet, the two research communities have only recently begun to coordinate their agendas. Such synchronization is the key to improving the potential for satellite data effectively to support future environmental management decision-making processes. With this themed issue, we aim to illustrate how integrating remote sensing into ecological research promotes a better understanding of the mechanisms shaping current changes in biodiversity patterns and improves conservation efforts. Added benefits include fostering innovation, generating new research directions in both disciplines and the development of new satellite remote sensing products.     

放线菌结瘤植物根与根瘤中有机氮化物的组分及其上运形式

杨梅、沙棘和赤杨三种放线菌结瘤植物根瘤、根部有机氮化物的组分中,都含有占总有机氮化物50％以上的尿囊酸,说明在它们的根瘤中合成了大量的酰脲;同时,三种植物结瘤植株的茎木质部提取物中也含有大量的尿囊酸,表明根瘤将其合成的酰脲向植物地上部位运送。三种植物的根瘤还将其合成的特定的氨基酸及酰胺向地上部位转运,其中杨梅根瘤将固定的氮素以Asn和Gln的形式输出,而根部则以Arg的形式向上转运;沙棘根瘤以Ash,Gln及Ser,赤杨根瘤以Cit的形式合成并转运固定的氮素;后两种植物的无根瘤植株,以NH_4~+为氮源时,在转运的氨基酸组分中Arg的比例明显提高。     

Development trends in taxonomy,with special reference to fungi

Taxonomy is a traditional subject, but it still receives attention and has become a topic of much discussion in recent years. Many of these discussions have raised concerns about the future of taxonomy, especially with regard to the workforce responsible for the discovery of new species in the context of declining biodiversity. Previous discussions were based on the taxonomic data of plants and animals, but the status of fungal taxonomy has not been mentioned. Fungi have one of the highest levels of biodiversity among all living organisms, second only to insects. The discussion of the future of taxonomy without the inclusion of fungal data is incomplete. Here, we present the results of analyses based on all new fungal taxa published since 1753. Fungal taxonomy is an ever‐growing area of study with increasing numbers of new taxa being described and growing numbers of fungal taxonomists. Compared with plants and most animal groups, there has been a much sharper increase in the rate at which new fungal taxa are being described. Furthermore, the number of taxonomists studying fungi has increased at a faster speed than those studying plants or animals. This indicates that fungal taxonomy is a prosperous subject and a dynamic area for scientific studies, and that it deserves much more attention and support. The study of fungal taxonomy will deepen our understanding of the biodiversity of our planet.     

不同功率递增速率对正常人心肺运动试验整体功能的影响Ⅱ—亚极限运动相关指标的影响*

目的: 观察健康志愿者不同功率递增速率完成症状限制性极限心肺运动试验（CPET）对CPET亚极限运动相关核心指标的影响。方法: 选择12名健康志愿者在一周内不同工作天随机完成中等适度程度（30 W/min）及比较低（10 W/min）和比较高（60 W/min）3种不同功率递增速率CPET。按标准方法比较12名志愿者CPET亚极限运动相关核心指标：无氧阈（AT）、单位功率摄氧量（ΔVO₂/ΔWR）、摄氧通气有效性峰值平台（OUEP）、二氧化碳通气当量平均90 s最低值（Lowest VE/ VCO₂）、二氧化碳通气当量斜率（VE/ VCO₂ Slope）及截距（intercept）和无氧阈时的摄氧通气效率值（VO₂/ VE@AT）和无氧阈时的二氧化碳通气当量值（VE/ VCO₂@AT）。对三组不同功率递增速率下各个指标的差异组间两两比较。结果: 中等适度功率递增速率组与比较低和比较高功率递增速率组相比摄氧通气有效性峰值平台（42.22±4.76 vs 39.54±3.30 vs 39.29±4.29）和二氧化碳通气当量平均90 s最小值（24.13±2.88 vs 25.60±2.08 vs 26.06±3.05）明显好,差异有统计学意义（P<0.05）;比较低、比较高功率递增速率组与中等适度功率递增速率组相比,单位功率摄氧量显著升高和降低（（8.45±0.66 vs 10.04±0.58 vs 7.16±0.60）ml/（min·kg））,差异有统计学意义（P<0.05）;无氧阈值没有发生明显改变（（0.87±0.19 vs 0.87±0.19 vs 0.89±0.19）L/min）,差异无统计学意义（P>0.05）;结论: 比较低、比较高功率递增速率可以明显改变摄氧通气有效性、二氧化碳排出通气有效性、单位功率摄氧量等CPET亚极限运动相关指标;选择比较低和比较高的功率递增速率和适度功率递增速率CPET相比明显降低了健康个体的摄氧通气有效性和二氧化碳排出通气有效性。CPET规范化操作要求选择适合受试者的功率递增速率,这样得到的CPET亚极限相关指标才最能反应受试者的真实功能状态。     

社会工作理念与医患冲突调解机制的建立

社会工作作为一种综合性专业性的助人活动,其理念应用于医疗实践能以专业的价值观和科学的方法,通过提供各种辅导和服务,协助患者及其家属与医方进行有效的沟通,促使医疗技术和服务更人性化地满足患者的需要,从而构建和谐的医患关系。在此过程中,社会工作者针对医患关系发展的不同阶段,分别拓展出不同的工作策略,扮演不同的服务角色。     

Postprandial Metabolic Profiles Following Meals and Snacks Eaten during Simulated Night and Day Shift Work

Shift workers are known to have an increased risk of developing cardiovascular disease (CVD) compared with day workers. An important factor contributing to this increased risk could be the increased incidence of postprandial metabolic risk factors for CVD among shift workers, as a consequence of the maladaptation of endogenous circadian rhythms to abrupt changes in shift times. We have previously shown that both simulated and real shift workers showed relatively impaired glucose and lipid tolerance if a single test meal was consumed between 00:00–02:00 h (night shift) compared with 12:00–14:00 h (day shift). The objective of the present study was to extend these observations to compare the cumulative metabolic effect of consecutive snacks/meals, as might normally be consumed throughout a period of night or day shift work. In a randomized crossover study, eight healthy nonobese men (20–33 yrs, BMI 20–25 kg/m²) consumed a combination of two meals and a snack on two occasions following a standardized prestudy meal, simulating night and day shift working (total energy 2500 kcal: 40% fat, 50% carbohydrate, 10% protein). Meals were consumed at 01:00/13:00 h and 07:00/19:00 h, and the snack at 04:00/16:00 h. Blood was taken after an overnight fast, and for 8 h following the first meal on each occasion, for the measurement of glucose, insulin, triacylglycerol (TAG), and nonesterified fatty acids (NEFA). RM-ANOVA (factors time and shift) showed a significant effect of shift for plasma TAG, with higher levels on simulated night compared to day shift (p < 0.05). There was a trend toward an effect of shift for plasma glucose, with higher plasma glucose at night (p = 0.08), and there was a time-shift interaction for plasma insulin levels (p < 0.01). NEFA levels were unaffected by shift. Inspection of the area under the plasma response curve (AUC) following each meal and snack revealed that the differences in lipid tolerance occurred throughout the study, with greatest differences occurring following the mid-shift snack. In contrast, glucose tolerance was relatively impaired following the first night-time meal, with no differences observed following the second meal. Plasma insulin levels were significantly lower following the first meal (p < 0.05), but significantly higher following the second meal (p < 0.01) on the simulated night shift. These findings confirm our previous observations of raised postprandial TAG and glucose at night, and show that sequential meal ingestion has a more pronounced effect on subsequent lipid than carbohydrate tolerance.     

Effects of visually demanding near work on trapezius muscle activity

Poor visual ergonomics is associated with visual and neck/shoulder discomfort, but the relation between visual demands and neck/shoulder muscle activity is unclear. The aims of this study were to investigate whether trapezius muscle activity was affected by: (i) eye-lens accommodation; (ii) incongruence between accommodation and convergence; and (iii) presence of neck/shoulder discomfort. Sixty-six participants (33 controls and 33 with neck pain) performed visually demanding near work under four different trial-lens conditions. Results showed that eye-lens accommodation per se did not affect trapezius muscle activity significantly. However, when incongruence between accommodation and convergence was present, a significant positive relationship between eye-lens accommodation and trapezius muscle activity was found. There were no significant group-differences. It was concluded that incongruence between accommodation and convergence is an important factor in the relation between visually demanding near work and trapezius muscle activity. The relatively low demands on accommodation and convergence in the present study imply that visually demanding near work may contribute to increased muscle activity, and over time to the development of near work related neck/shoulder discomfort.     

Energy cost and running mechanics during a treadmill run to voluntary exhaustion in humans

The aim of the present study was to examine the physiological and mechanical factors which may be concerned in the increase in energy cost during running in a fatigued state. A group of 15 trained triathletes ran on a treadmill at velocities corresponding to their personal records over 3000m [mean 4.53 (SD 0.28) m · s⁻¹] until they felt exhausted. The energy cost of running (C _R) was quantified from the net O₂ uptake and the elevation of blood lactate concentration. Gas exchange was measured over 1 min firstly during the 3rd–4th min and secondly during the last minute of the run. Blood samples were collected before and after the completion of the run. Mechanical changes of the centre of mass were quantified using a kinematic arm. A significant mean increase [6.9 (SD 3.5)%, P < 0.001] in C _R from a mean of 4.4 (SD 0.4) J · kg⁻¹ · m⁻¹ to a mean of 4.7 (SD 0.4) J · kg⁻¹ · m⁻¹ was observed. The increase in the O₂ demand of the respiratory muscles estimated from the increase in ventilation accounted for a considerable proportion [mean 25.2 (SD 10.4)%] of the increase in C_R. A mean increase [17.0 (SD 26.0)%, P < 0.05] in the mechanical cost (C _M) from a mean of 2.36 (SD 0.23) J · kg⁻¹ · m⁻¹ to a mean of 2.74 (SD 0.55) J · kg⁻¹ · m⁻¹ was also noted. A significant correlation was found between C _R and C _M in the non-fatigued state (r = 0.68, P < 0.01), but not in the fatigued state (r = 0.25, NS). Furthermore, no correlations were found between the changes (from non-fatigued to fatigued state) in C _R and the changes in C _M suggesting that the increase in C _R is not solely dependent on the external work done per unit of distance. Since step frequency decreased slightly in the fatigued state, the internal work would have tended to decrease slightly which would not be compatible with an increase in C _R. A stepwise regressions showed that the changes in C _R were linked (r = 0.77, P < 0.01) to the changes in the variability of step frequency and in the variability of potential cost suggesting that a large proportion of the increase in C _R was due to an increase in the step variability. The underlying mechanisms of the relationship between C _R and step variability remains unclear. Accepted: 15 September 1997