The impact of fossils on the Evolutionary Distinctiveness and conservation status of the Australian lungfish

The recognition of phylogenetic information for evaluating conservation priorities has stressed the importance of basal taxa. The “Evolutionary Distinctiveness” index (ED) is a species-specific index that includes branch length expressed as an absolute value measured in millions of years that can be applied to a single terminal taxon in a phylogeny. The ED depends on the tree pattern, i.e. of a cladogram included into a time-scale. When calculated for the Australian lungfish (Neoceratodusforsteri), a threatened dipnoan that occurs naturally only in southeast Queensland, the ED index shows variable value according to the chosen tree. On the basis of a recently proposed phylogeny including a new fossil find from the Early Cretaceous of Thailand, the ED value reaches the highest value for piscine sarcopterygians, and for all vertebrates, and thus reinforces the “originality” of this fish. This example points out the importance of fossils in the resolution of phylogenies and beyond, in the calculation of indexes supporting conservation decisions.     

Effect of street trees on microclimate and air pollution in a tropical city

One of the fastest growing cities in India, Bangalore is facing challenges of urban microclimate change and increasing levels of air pollution. This paper assesses the impact of street trees in mitigating these issues. At twenty locations in the city, we compare segments of roads with and without trees, assessing the relationship of environmental differences with the presence or absence of street tree cover. Street segments with trees had on average lower temperature, humidity and pollution, with afternoon ambient air temperatures lower by as much as 5.6 °C, road surface temperatures lower by as much as 27.5 °C, and SO₂ levels reduced by as much as 65%. Suspended Particulate Matter (SPM) levels were very high on exposed roads, with 50% of the roads showing levels approaching twice the permissible limits, while 80% of the street segments with trees had SPM levels within prescribed limits. In an era of exacerbated urbanization and climate change, tropical cities such as Bangalore will have to face some of the worst impacts including air pollution and microclimatic alterations. The information generated in this study can help appropriately assess the environmental benefits provided by urban trees, providing useful inputs for urban planners.     

奶牛的饮水行为和饮水需要

阐述了奶牛饮水理论的基本知识：水在奶牛体内的代谢特征,奶牛对水的数量和质量的需求,奶牛饮水量的预测,奶牛的饮水习惯和关于水质的内容.总结了大量的奶牛饲养当中有关饮水管理的实践经验和理论研究结果.     

Increased drug concentration and repeated eye drop administration as strategies to optimize topical drug delivery: A fluorophotometric study in healthy dogs

Objectives

Determine tear film kinetics with different fluorescein concentrations and repeated eye drop administration at various time intervals.

Animals Studied

Six healthy Beagles.

Procedures

Six experiments were conducted on separate days: single eye drop administration (control) or two separate eye drops administered at 30 s, 1, 2, 5, and 10 min intervals. For each experiment, one eye received 0.3% fluorescein solution while the other eye received 1% fluorescein solution, and tear fluid was collected with capillary tubes at 0, 1, 5, 10, 20, 30, 40, 50, 60, 90, 120, and 180 min. Fluorescein concentrations were measured using automated fluorophotometry.

Results

Compared with 0.3% solution, eyes receiving 1% fluorescein solution had significantly higher tear film concentrations (p ≤ .046) and the area-under-the-fluorescein-time curve was twofold greater (p = .005). Compared with control: (i) Tear film concentrations were significantly higher for up to 20 min when repeating administration 30 s to 5 min after the first drop (p ≤ .006); (ii) The highest increase in area-under-the-curve was obtained with 2 and 5 min intervals for 0.3% (+109%–130%) and 1% solutions (+153%–157%); (iii) The highest increase in median precorneal retention time (defined as tear film concentration < 5% from baseline values) was obtained with 5 min intervals for 0.3% (55 min vs. 15 min in control) and 2–5 min intervals for 1% solutions (50 min vs. 25 min in control).

Conclusions

Drug delivery to the ocular surface can be enhanced by using more concentrated formulations and/or by repeating eye drop administration 2–5 min after the first dose.     

The regulation of apoplastic calcium in relation to intracellular signalling in stomatal guard cells

It is now well established that calcium has a substantive role in intracellular signalling in stomatal guard cells. Much less attention has, however, been paid to the importance of maintaining an apoplastic calcium concentration which permits this mechanism to operate. Data are presented for the calcicole Leontodon hispidus, in which the xylem sap may contain over 16 mM free calcium, showing that the concentration of calcium in the guard cell apoplast may be as low as 0.10 mM. This appears to be achieved by the deposition of considerable amounts of calcium oxalate in the mesophyll, particularly in the palisade tissue. Of the calcium delivered directly into the epidermis by the transpiration stream, a large proportion is diverted into the trichomes. It seems unlikely that stomatal regulation over long distances (e.g. from root to shoot) is accomplished via apoplastic calcium, but over shorter distances (the span of a few cells in the epidermis) signalling via calcium in the apoplast is entirely feasible and it is worthy of further investigation.