Effect of climate change on breeding phenology,clutch size and chick survival of an upland bird

Upland birds are predicted to be particularly vulnerable to the effects of climate change, yet few studies have examined these effects on their breeding phenology and productivity. Laying dates of Red Grouse Lagopus lagopus scotica in the Scottish Highlands advanced by 0.5 days/year between 1992 and 2011 and were inversely correlated with pre‐laying temperature, with a near‐significant increase in temperature over this period. Earlier clutches were larger and chick survival was greater in earlier nesting attempts. However, chick survival was also higher in years with lower May temperatures and lower August temperatures in the previous year, the latter probably related to prey abundance in the subsequent breeding season. Although laying dates are advancing, climate change does not currently appear to be having an overall effect on chick survival of Red Grouse within the climate range recorded in this study.     

Observation of the helical structure of the bacterial polysaccharide acetan by atomic force microscopy.

A method has been developed that has been found to give reproducible images of uncoated polysaccharides by Atomic Force Microscopy (AFM). Aqueous solutions of the polysaccharide are deposited as drops onto freshly cleaved mica surfaces, air dried, and then imaged under butanol. The method has been used to obtain images of the bacterial polysaccharide acetan. In regions within the deposited sample, where the molecules are aligned side-by-side, it has been possible to observe a periodic structure along the polysaccharide chain, attributable to the helical structure of acetan.     

Pathogenicity of mouse hepatitis virus for preimplantation mouse embryos

Mouse embryos which were hatched from the zona pellucida in vitro in the presence of mouse hepatitis virus (MHV) or outgrown on coverslips and then exposed to MHV were shown by immunohistochemical staining to have virally infected trophoblast cells. Zona-intact embryos incubated with MHV for 48 h (2-cell embryos) or 1.5 h (blastocysts) were resistant to infection. Morulae and early blastocysts collected from donor mice experimentally infected with MHV were not infected, but the medium in which they were flushed from the uterine horns was contaminated with virus. No virus was detected after embryos were washed through three changes of uncontaminated medium. MHV was transmitted to foster mothers when embryos were transferred in medium contaminated with the virus. Fetal and decidual tissues were not infected. We suggest that embryo transfer is an effective and simple alternative to Caesarian rederivation of MHV-contaminated mice.     

Patient choice significantly affects mastectomy rates in the treatment of breast cancer

Mastectomy rates may be affected by patient choice. 203 patients who had a Total Mastectomy for breast cancer were invited to complete questionnaires at routine follow up clinics to ascertain if they had been offered a choice of Breast Conserving Surgery (BCS), and to establish the reasons for their preference. Questionnaires were checked against medical and nursing records to confirm the reasons for the patients' choice of mastectomy. 130 patients (64%) chose to have a mastectomy, reporting that they felt safer (n = 119); wanted to decrease the risk of further surgery (n = 87) and/or wished to avoid radiotherapy (n = 34). Some were advised not to have BCS if they had a large tumour size, central or multifocal tumours and/or associated extensive microcalcification on mammography (n = 29). 24 patients had BCS as first operation but had repeat surgery for involved or narrow excision margins. Despite being advised that there is no difference between survival rates of this and breast conserving surgery, many patients still feel safer with mastectomy.     

Mechanism of estrogen-mediated intestinal protection following trauma-hemorrhage: p38 MAPK-dependent upregulation of HO-1

p38 MAPK has been reported to regulate the inflammatory response in various cell types via extracellular stimuli. p38 MAPK activation also results in the induction of heme oxygenase (HO)-1, which exerts potent anti-inflammatory effects. Although studies have shown that 17beta-estradiol (E(2)) prevented organ dysfunction following trauma-hemorrhage, it remains unknown whether p38 MAPK/HO-1 plays any role in E(2)-mediated attenuation of intestinal injury under those conditions. To study this, male rats underwent trauma-hemorrhage (mean blood pressure approximately 40 mmHg for 90 min) followed by fluid resuscitation. At the onset of resuscitation, rats were treated with vehicle, E(2) (1 mg/kg body wt), the p38 MAPK inhibitor SB-203580 (2 mg/kg body wt) or E(2) plus SB-203580. Two hours thereafter, intestinal myeloperoxidase (MPO) activity and lactate, TNF-alpha, IL-6, ICAM-1, cytokine-induced neutrophil chemoattractant (CINC)-1, and macrophage inflammatory protein (MIP)-2 levels were measured. Intestinal p38 MAPK and HO-1 protein levels were also determined. Trauma-hemorrhage led to an increase in intestinal MPO activity and lactate, TNF-alpha, IL-6, ICAM-1, CINC-1, and MIP-2 levels. This was accompanied with a decrease in intestinal p38 MAPK activity and increase in HO-1 expression. Administration of E(2) normalized all the above parameters except HO-1, which was further increased following trauma-hemorrhage. Administration of SB-203580 with E(2) abolished the E(2)-mediated restoration of the above parameters as well as the increase in intestinal HO-1 expression following trauma-hemorrhage. These results suggest that the p38 MAPK/HO-1 pathway plays a critical role in mediating the salutary effects of E(2) on shock-induced intestinal injury.     

Responses of adult mosquitoes of two sibling species, Anopheles arabiensis and A. gambiae s.s. (Diptera: Culicidae), to high temperatures

It is well known that amongst the sibling species of the Anopheles gambiae complex, A. arabiensis Patton predominates over A. gambiae sensu stricto Giles in hotter, drier parts of Africa. Here it was investigated whether A. arabiensis is better adapted to higher temperatures than A. gambiae s.s. at the microclimatic level. Bioassays were used to assess behavioural avoidance activity of adult mosquitoes in the presence of increasing temperature. Female mosquitoes were introduced into a holding tube from which they could escape into a cage through a one-way funnel. From a starting temperature of 28 degrees C they were exposed to a 2 degrees C rise in temperature every 30 min until all mosquitoes had escaped or been knocked down. As temperature increased, A. arabiensis left the holding tube at higher temperatures than A. gambiae s.s. (A. arabiensis mean activation temperature = 35.7 degrees C, 95% CIs = 35.4-36.1 degrees C; A. gambiae s.s. = 33.0 degrees C, 32.5-33.5 degrees C). To determine the relative ability of both species to survive at extremely high temperatures, batches of insects were exposed to 40 degrees C for different periods. It took considerably longer to kill 50% of A. arabiensis at 40 degrees C than it did A. gambiae s.s. (112 min vs. 67 min). These data show that adult A. arabiensis are better adapted to hotter conditions than A. gambiae s.s., a characteristic that is reflected in their spatial and temporal distribution in Africa.     

CheY-dependent methylation of the asparagine receptor, McpB, during chemotaxis in Bacillus subtilis

For the Gram-positive organism Bacillus subtilis, chemotaxis to the attractant asparagine is mediated by the chemoreceptor McpB. In this study, we show that rapid net demethylation of B. subtilis McpB results in the immediate production of methanol, presumably due to the action of CheB. We also show that net demethylation of McpB occurs upon both addition and removal of asparagine. After each demethylation event, McpB is remethylated to nearly prestimulus levels. Both remethylation events are attributable to CheR using S-adenosylmethionine as a substrate. Therefore, no methyl transfer to an intermediate carrier need be postulated to occur during chemotaxis in B. subtilis as was previously suggested. Furthermore, we show that the remethylation of asparagine-bound McpB requires the response regulator, CheY-P, suggesting that CheY-P acts in a feedback mechanism to facilitate adaptation to positive stimuli during chemotaxis in B. subtilis. This hypothesis is supported by two observations: a cheRBCD mutant is capable of transient excitation and subsequent oscillations that bring the flagellar rotational bias below the prestimulus value in the tethered cell assay, and the cheRBCD mutant is capable of swarming in a Tryptone swarm plate.