Differential association between circulating testosterone and infection risk by several viruses in natural cat populations: a behavioural-mediated effect?

Testosterone is involved in the development and expression of physiological, morphological and behavioural traits. High levels are often associated with high infection risk and/or intensity, suggesting a trade-off between sexual traits and immunity. Classically invoked mechanisms are immunological or behavioural, i.e., testosterone increases susceptibility or resistance to parasites via an impact on immunity or modulates behaviours involved in parasite transmission. However, studies report contrasted patterns. Given its modes of action and the diversity of host-parasite interactions, testosterone should not act similarly on all interactions. To reduce host and context diversity, we studied 3 viruses in the same cat population: the aggressively transmitted Feline Immunodeficiency virus (FIV), and the Feline Calicivirus (FCV) and Herpesvirus (FHV) both transmitted during friendly contacts. Testosterone had a strong effect on the probability of being positive to FIV whereas its effect was significantly weaker on FCV and FHV. These findings demonstrate that testosterone can be differentially associated with parasites of the same type (viruses). The difference we observed was consistent with a behavioural-mediated effect (increased aggressiveness), supporting the idea that the testosterone effect on infection risk is at least partially driven by behavioural mechanisms in our system. Further investigations (e.g., individual immunity measures) are required to confirm this hypothesis.

Chaos-assisted tunneling with cold atoms.

In the context of quantum chaos, both theory and numerical analysis predict large fluctuations of the tunneling transition probabilities when irregular dynamics is present at the classical level. Here we consider the nondissipative quantum evolution of cold atoms trapped in a time-dependent modulated periodic potential generated by two laser beams. We give some precise guidelines for the observation of chaos-assisted tunneling between invariant phase space structures paired by time-reversal symmetry.

The posterior arm free flap.

A new cutaneous free flap is described on the posterior side of the arm. This flap is supplied by an unnamed artery from the humeral artery or the deep humeral artery. It is drained by the accompanying venae comitantes. Its nerve supply is from the radial nerve. Its advantage is a flexible skin and a primary closure of the donor site if the flap does not exceed 7 cm in width. The principal disadvantage is its modest measurements. This flap has been employed in five cases for reconstruction of hand and foot. All flaps survived despite a necessary revision of an arterial anastomosis in one case and a partial necrosis in another case. Results are satisfactory, especially in restoration of weight-bearing areas of the foot.

[Blount's disease in the Antilles. Apropos of 26 cases]. / La maladie de Blount aux Antilles. A propos de 26 observations.

Blount's disease is associated with agenesis of the medial tibial plateau leading to tibia vara. It appears to be more frequent in Scandinavian countries and in black populations. Twenty-six cases had been seen in Martinique (Antilles) of whom twenty were children. A classification into six stages was described. Stage IV is a critical one. Before it, corrective osteotomy will often lead to complete healing. After stage IV, lateral epiphysiodesis must be added to avoid recurrence of deformity. The technique of osteotomy was variable according to the age of the child and the obliquity of the joint line. In young children, a subtraction closing wedge osteotomy is suitable. In older children a "V" shaped osteotomy is recommended to lessen the amount of shortening. At the end of the growth period, a medial opening wedge osteotomy is advisable. In adults (six cases) whose deformity can reach as much as 50 degrees with considerable ligamentous laxity, reefing of the ligament must be added to the osteotomy. The problem of the opposite knee is discussed. Even when the disease is not bilateral, it can tend to develop towards arthrosis.

[Surgical methods in non-traumatic perforations of the colon into the free peritoneum (36 cases)]. / Tactique opératoire dans les perforations non traumatiques du côlon en péritoine libre. (36 observations)

When operating as an emergency for a perforation of the colon should one carry out a by-pass operation, colostomy or restore intestinal continuity? 36 colonic perforations are reported here, as a complication of cancer in 50 p. 100 of cases, or sigmoiditis in 38 p. 100 of cases. The perforation was situated on the sigmoid in 77 p. 100 of cases. 13 by-pass operations were carried out with a 23 p. 100 mortality, 12 colectomies without anastomosis with a 50 p. 100 mortality, and 2 colectomies with restoration of continuity, 9 p. 100 mortality. The overall mortality was 27.7 p. 100 much less than reported by other authors but, nevertheless partly due to the severity of peritonitis due to the presence of feces and, partly due to the operation adopted. The present attitude of the authors depends on the merits of each case. A large incision is made and the peritoneum thoroughly cleaned. If the surgeon is experienced, colonic resection is advisable for perforated cnacer and certain cases of sigmoiditis. Restoration of continuity depends, above all, on the anatomical condition of the colon above the lesion. Hartmann's resections or by-pass operations thus still have indications.

Deepwater formation in the North Pacific during the Last Glacial Termination.

Between approximately 17,500 and 15,000 years ago, the Atlantic meridional overturning circulation weakened substantially in response to meltwater discharges from disintegrating Northern Hemispheric glacial ice sheets. The global effects of this reorganization of poleward heat flow in the North Atlantic extended to Antarctica and the North Pacific. Here we present evidence from North Pacific paleo surface proxy data, a compilation of marine radiocarbon age ventilation records, and global climate model simulations to suggest that during the early stages of the Last Glacial Termination, deep water extending to a depth of approximately 2500 to 3000 meters was formed in the North Pacific. A switch of deepwater formation between the North Atlantic and the North Pacific played a key role in regulating poleward oceanic heat transport during the Last Glacial Termination.