Anteversion versus torsion of the femoral neck.

The usual term 'torsion angle of the femur' denotes the 'anteversion' of the neck of the femur as a whole, caused by the twist in the shaft of the femur rather than the twist in the neck. This has been differentiated from the twist in the neck of the femur around its own axis, termed 'torsion neck' and the values of both have been measured. To differentiate these two different phenomena, the term 'anteversion' is used to denote the usual angel described, while 'torsion neck' is sued to denote the twist in the neck around its own axis measured in this work. 1,000 femora from 21 cites in different parts of the country have been measured and the average anteversion angle calculated. The Indian average works out to be 12 degrees with a significantly (double) high value for females. The incidence of negative angle is 7% in the normal femora. All fractured femora invariably show a negative angle. The above information should be of great significance on orthopaedic surgery of the neck of the femur in these bones. The 'torsion neck' has been measured by tracing and its average reported as 30 degrees.     

Initiation of Purinergic Signaling by Exocytosis of ATP-containing Vesicles in Liver Epithelium

Extracellular ATP represents an important autocrine/paracrine signaling molecule within the liver. The mechanisms responsible for ATP release are unknown, and alternative pathways have been proposed, including either conductive ATP movement through channels or exocytosis of ATP-enriched vesicles, although direct evidence from liver cells has been lacking. Utilizing dynamic imaging modalities (confocal and total internal reflection fluorescence microscopy and luminescence detection utilizing a high sensitivity CCD camera) at different scales, including confluent cell populations, single cells, and the intracellular submembrane space, we have demonstrated in a model liver cell line that (i) ATP release is not uniform but reflects point source release by a defined subset of cells; (ii) ATP within cells is localized to discrete zones of high intensity that are ∼1 μm in diameter, suggesting a vesicular localization; (iii) these vesicles originate from a bafilomycin A₁-sensitive pool, are depleted by hypotonic exposure, and are not rapidly replenished from recycling of endocytic vesicles; and (iv) exocytosis of vesicles in response to cell volume changes depends upon a complex series of signaling events that requires intact microtubules as well as phosphoinositide 3-kinase and protein kinase C. Collectively, these findings are most consistent with an essential role for exocytosis in regulated release of ATP and initiation of purinergic signaling in liver cells.     

Latitudinal variation in blue tit and great tit nest characteristics indicates environmental adjustment

Aim The laying of eggs and the building of a nest structure to accommodate them are two of the defining characteristics of members of the class Aves. Nest structures vary considerably across avian taxa and for many species the structure of the completed nest can have important consequences both for parents and their offspring. While nest characteristics are expected to vary adaptively in response to environmental conditions, large‐scale spatial variation in nest characteristics has been largely overlooked. Here, we examine the effects of latitudinal variation in spring temperatures on nest characteristics, including insulatory properties, and reproductive success of blue tits, Cyanistes caeruleus, and great tits, Parus major. Location Great Britain. Methods Nests and reproductive data were collected from seven study sites, spread over 5° of latitude. The nest insulatory properties were then determined before the nests were separated into nest base material and cup lining material. Results As spring temperatures increased with decreasing latitude, the mass of the nest base material did not vary in either species, while the mass of the cup lining material and nest insulatory properties decreased in both species. This suggests that in response to increasing temperatures the breeding female reduces the mass of the cup lining material, thereby maintaining an appropriate microclimate for incubating and brooding. The mean first egg date of both species advanced with decreasing latitude and increasing spring temperatures, although clutch size and brood size at hatching and fledging did not vary. Main conclusions This is the first study to demonstrate that the nest‐construction behaviour of birds varies in response to large‐scale spatial variation in ambient temperatures. Therefore, nest composition reliably indicates environmental conditions and we suggest that studies of nest structure may be sentinels for the early signs of rapid climate change.