Structure,development and function of the branchial sieve of the common bream,Abramis brama,white bream,Blicca bjoerkna and roach,Rutilus rutilus

Synopsis The filter feeding organ of cyprinid fishes is the branchial sieve, which consists of a mesh formed by gill rakers and tiny channels on the gill arches. In order to establish its possible role during growth we measured the following morphological gill raker parameters over a range of sizes in three cyprinid fishes, bream, white bream and roach: inter raker distance, bony raker length, raker width, cushion length and channel width. At any given standard length common bream has the largest inter raker distance, roach the lowest and white bream is intermediate. In the comb model of filter feeding the inter raker distance is considered to be a direct measure of the mesh size and retention ability (= minimal size of prey that can be retained) of a filter. For the three species under study there is a conflict between the comb model and experimental data on particle retention. Lammens et al. (1987) found that common bream has a large retention ability whereas roach and white bream have a much smaller one. A new model, the channel model (Hoogenboezem et al. 1991) has been developed for common bream; in this model the lateral gill rakers can regulate the mesh size of the medial channels on the other side of the gill slit. The present data indicate that this model is not appropriate for white bream and roach. At any given standard length white bream and roach only reach 70% of the raker length of common bream, which means that in this model the gill slits should to be very narrow during filter feeding. The gill rakers consist of a bony raker and a fleshy cushion. The bony rakers have a rather long needle-like part outside the cushion in bream, but not in white bream and roach which have blunt gill rakers. Blunt gill rakers are not suited to reduce the diameter of the medial channels. The comb model seems more appropriate for white bream and roach, but doubts about the validity of this simple model remain. The sum of the areas of the medial channels is an approximation of the area through which water flows in the filter. This channel area therefore gives an impression of the capacity or flow rate of the filter. With this capacity estimation and an estimation of energy consumption we calculated an energy ratio of filter feeding. The energy ratio decreases with increasing standard length with an exponent close to the expected exponent of -0.40. The energy ratio is highest in bream, intermediate in white bream and lowest in roach.     

A statistical model of the competition curve

1. A theoretical model for the competition curve, which stands on a few simple assumptions, was proposed.
2. Some applications were done to actual data, and during these applications the validity of the present model and its assumptions was discussed.
3. From the present model it can be expected that there is a discrete competition mechanism even in the appearently continuous medium.

     

基于生态供给-消耗平衡关系的中尼廊道地区生态承载力研究

中尼廊道地区作为南亚通道建设的关键环节,具有生态环境脆弱且对生态资源依赖性强的基本特征,中尼廊道建设占用生态空间,将增加生态系统对农牧业生产活动的承载压力;因此,开展中尼廊道生态承载力研究对青藏高原生态保护和南亚通道建设具有重要的实践价值和指导意义。本文基于生态供给与消耗平衡关系,通过计算农牧业生产对生态系统净初级生产力的消耗,评估中尼廊道地区的生态承载力,结果表明：（1）中尼廊道地区生态承载力处于富富有余状态,2015年有7个县域生态承载力处于临界超载或平衡有余状态;整体上生态系统尚有较大的生态空间来支撑中尼廊道建设,但建设可能給局部县域带来超载风险。（2）中尼廊道地区生态系统供给量处于稳定波动状态,畜牧业生态消耗在生态消耗中占主导地位（占比超80%）;得益于2005年起实施的草畜平衡政策,中尼廊道地区及其24个县域生态消耗量呈下降趋势,农牧业生产活动对生态系统造成的压力降低,生态承载状态向优发展;但地处粮食主产区、口岸区、城市化辐射区的7个县域,在本地及周边地区日益增长的对农牧业产品的生活需求驱动下生态消耗量处于增加态势。（3）若以实现生物多样性公约所倡导的50%生态资源得到保护为生态保护目标,目前中尼廊道农牧业生产模式产生的生态消耗将超出其可利用供给,区域可持续发展需要关注如何通过中尼廊道建设带动当地产业结构调整以缓解农牧业生产对生态系统的压力。     

Transferrin Modifications and Lipid Peroxidation: Implications in Diabetes Mellitus

Free iron is capable of stimulating the production of free radicals which cause oxidative damage such as lipid peroxidation. One of the most important mechanisms of antioxidant defense is thus the sequestration of iron in a redox-inactive form by transferrin. In diabetes mellitus, increased oxidative stress and lipid peroxidation contribute to chronic complications but it is not known if this is related to abnormalities in transferrin function. In this study we investigated the role of transferrin concentration and glycation. The antioxidant capacity of apotransferrin to inhibit lipid peroxidation by iron-binding decreased in a concentration-dependent manner from 89% at <formula>≥2 mg/ml</formula> to 42% at 0.5 mg/ml. Pre-incubation of apotransferrin with glucose for 14 days resulted in a concentration-dependent increase of glycation: 1, 5 and 13 μmol fructosamine/g transferrin at 0, 5.6 and 33.3 mmol/l glucose respectively, p<0.001. This was accompanied by a decrease in the iron-binding antioxidant capacity of apotransferrin. In contrast, transferrin glycation by up to 33.3 mmol/l glucose did not affect chemiluminescence-quenching antioxidant capacity, which is iron-independent. Colorimetric evaluation of total iron binding capacity in the presence of an excess of iron (iron/transferrin molar ratio=2.4) also decreased from 0.726 to 0.696 and 0.585 mg/g transferrin after 0, 5.6 and 33.3 mmol/l glucose, respectively, p<0.01. In conclusion, these results suggest that lower transferrin concentration and its glycation can, by enhancing the pro-oxidant effects of iron, contribute to the increased lipid peroxidation observed in diabetes.     

Current capacity,bottlenecks, and future projections for offsetting habitat loss using Mitigation and Conservation banking in the United States

Habitat banking in its many iterations is an established and popular mechanism to deliver environmental offsets. The United States can look back at over 30 years of banking experience with the underlying framework and policies being consistently updated and improved. Given the increased demand in habitat banking, we provide insights into how bank area capacity is distributed across the United States for four different bank targets (wetlands, streams, multiple ecosystems, species) based on information extracted from the Regulatory In-lieu Fee and Bank Information Tracking System, as well as, estimating future capacities and area reserves through a predictive modeling approach based on data from the past 26 years. Future predictions indicate a decrease in available reserves for banks targeting wetlands or multiple ecosystems, with potential bottlenecks relating to large reserves being limited to the southeast and release schedules not catching up to the current and anticipated demand. Banks targeting species or streams are predicted to meet future demand, with species banks (conservation banks) following a different legislative and operational approach based on the listing of endangered species and pro-active approaches with anticipated future demand. Most current reserves for all four bank types are restricted to very few service areas with around one-third of all bank areas still awaiting release, limiting their availability on a broader scale. Strategic planning networks are necessary to meet future demand on a national scale and to identify areas suitable for banking or likely to experience future environmental or developmental stress.     

The contribution of small individuals to density-body size relationships: examination of energetic equivalence in reef fishes

A key relationship in ecology is that between density and body size, with the emphasis placed on energetic rules constraining the abundance of larger organisms below that of smaller organisms. Most studies have focused upon the density-body size relationship at the species level. However, energy is gathered at an individual level. We therefore examined this relationship in a coral reef fish assemblage, focusing on individuals. Using a comprehensive data set, with over 14,000 observations we found that the relationship between local density and adult body size differs from the linear relationship predicted by the energetic equivalence rule. However, excluding the smallest size classes, the relationship between body size and individual abundance for intermediate to larger fish did not depart from the predicted –0.75. Unlike plants and intermediate to large reef fishes, the smallest fishes appear to have constraints that may reflect different patterns of resource acquisition.     

Public vaccine manufacturing capacity in the Latin American and Caribbean region: Current status and perspectives

The vaccine global market is currently growing at a rate of 16.52%. Nowadays the vaccine manufacturing industry is limited in the sense that not all vaccine manufacturers have the capacity to execute all the steps necessary to produce a successful product. The biological variation inherent to vaccine manufacturing and the initial investment required to bring a vaccine to the market are some of the factors that discourage vaccine manufacturing initiatives.Given the current global context in vaccine innovation and production, and the increasing participation of vaccine manufacturers from developing countries in global markets, this paper aims to review vaccine manufacturing capacity in Latin American and Caribbean (LAC) countries with specific focus on trends in national or public sector manufacturing, presenting current challenges and future opportunities for the sector in meeting national and regional (LAC) needs.Despite the overall low vaccine manufacturing capacity reported within the LAC region within this paper, it is considered that the relatively high and concentrated capacity that exists within a number of countries, combined with political commitment of all countries within the Region, can provide the necessary platform for the continued development of capacity in vaccine development and manufacture within LAC.     

Longitudinal inspiratory capacity changes in chronic obstructive pulmonary disease

Background

The changes in inspiratory capacity (IC) over time in chronic obstructive pulmonary disease (COPD) patients are unknown. The Understanding Potential Long-term Impacts on Function with Tiotropium (UPLIFT®) trial included IC measurements.

Methods

IC analysis from UPLIFT® (N = 5992) was performed at 1 and 6 months, and every 6 months through 4 years. Annualized rate of decline in pre- and post-bronchodilator IC and mean differences at each time point were analyzed by mixed-effects models. The relationships between baseline IC and exacerbation rate and mortality were explored using Cox regression analysis.

Results

Baseline characteristics: age, 65 years; 75% men; post-bronchodilator forced expiratory volume in 1 second, 1.32 L (48% predicted); pre- and post-bronchodilator IC, 2.03 and 2.33 L. Mean IC rate of decline (mL/year) was 34 ± 2 (1.7% of baseline) and 50 ± 3 (2.1% of baseline) pre- and post-bronchodilator, respectively, without significant between-group differences. Morning pre-bronchodilator (trough) IC improved with tiotropium versus placebo: 124 mL (1 month), 103 mL (1 year), 107 mL (2 years), 98 mL (3 years), and 97 mL (4 years) (all p < 0.001). Post-bronchodilator improvements were similar between treatment groups. Lower baseline IC values were associated with reduced time to first exacerbation. For the lowest quartile (n = 1413) the values in months were 14.3 (11.7–17.0) for tiotropium and 10.3 (8.8–11.7) for controls (p < 0.01).

Conclusion

IC declines from approximately 34 to 50 mL/year in patients with stage II to IV COPD. Tiotropium treatment does not change the IC decline rate but provides 24-hour improvements in IC sustained over the long term. Trough IC differences suggest that tiotropium provides sustained decrease in end-expiratory lung volume.     

冷驯化对中缅树能量代谢的影响

在 5± 1℃条件下对中缅树鼠句进行冷驯化处理 ,测定其能量代谢。冷驯化 2 8d后 ,体重比对照组显著增加 7 3 3 % ;整体能值达到 3 0 47± 0 46kJ/g (N =8) ,比对照组增加4 98% ;摄入能比对照组增加 3 6 1 7% ;同化能比对照组增加 6 6 2 % ;生长能达到 6 98±0 5 3kJ/1 0 0g (N =7)体重·天 ,是对照组的 4 85倍 ;维持能比对照组增加 6 4 0 % ,达到3 5 2 96± 2 8 3 4kJ/1 0 0g体重·天 (N =7)。以上结果表明中缅树鼠句在冷胁迫影响下 ,以增加能量摄入、能量储存和维持能和降低排泄能量的生理机制来维持能量代谢平衡 ,以此对策来提高低温环境适应能力     

Enhancement of Enzymatic Adipyl-7-ADCA Hydrolysis

We studied enzymatic adipyl-7-ADCA hydrolysis as a new process for the production of 7-aminodeacetoxycephalosporanic acid (7-ADCA), one of the building blocks for cephalosporin antibiotics like cephalexin and cefadroxil. Adipyl-7-ADCA hydrolysis carried out with immobilised glutaryl acylase was considerably enhanced by addition of phenylglycine amide, the side-chain donor used for cephalexin synthesis; unlike reactions carried out with free enzyme. The rate enhancing effect was not specifically related to phenylglycine amide; we found a linear relationship between the reaction rate and the buffering capacity of the added substance. These observations can be explained by a pH-gradient in the immobilised enzyme, the pH inside the particle being lower (corresponding to low enzyme activity) than outside. It was concluded that the buffer reduced the pH-gradient inside the biocatalyst, and therewith, caused the reaction rate enhancing effects. Further, chloride ions decreased the reaction rate strongly, while sodium, magnesium, sulphate, and potassium did not influence the reaction rate much. For an actual process, it is important to use a buffer that is appropriate for the reaction-pH. In that way the amount of enzyme required in a process can be reduced considerably, in our case a factor of three was found.