Effects of brood size manipulation and common origin on phenotype and telomere length in nestling collared flycatchers.

BACKGROUND: Evidence is accumulating that telomere length is a good predictor of life expectancy, especially early in life, thus calling for determining the factors that affect telomere length at this stage. Here, we investigated the relative influence of early growth conditions and origin (genetics and early maternal effects) on telomere length of collared flycatchers (Ficedula albicollis) at fledging. We experimentally transferred hatchlings among brood triplets to create reduced, control (i.e. unchanged final nestling number) and enlarged broods. RESULTS: Although our treatment significantly affected body mass at fledging, we found no evidence that increased sibling competition affected nestling tarsus length and telomere length. However, mixed models showed that brood triplets explained a significant part of the variance in body mass (18%) and telomere length (19%), but not tarsus length (13%), emphasizing that unmanipulated early environmental factors influenced telomere length. These models also revealed low, but significant, heritability of telomere length (h(2) = 0.09). For comparison, the heritability of nestling body mass and tarsus length was 0.36 and 0.39, respectively, which was in the range of previously published estimates for those two traits in this species. CONCLUSION: Those findings in a wild bird population demonstrate that telomere length at the end of the growth period is weakly, but significantly, determined by genetic and/or maternal factors taking place before hatching. However, we found no evidence that the brood size manipulation experiment, and by extension the early growth conditions, influenced nestling telomere length. The weak heritability of telomere length suggests a close association with fitness in natural populations.

Age Related Outcome in Acute Subdural Haematoma Following Traumatic Head Injury

Acute subdural haematoma (ASDH) is one of the conditions most strongly associated with severe brain injury. Reports prior to 1980 describe overall mortality rates for acute subdural haematomas (SDH's) ranging from 40% to 90% with poor outcomes observed in all age groups. Recently, improved results have been reported with rapid diagnosis and surgical treatment. The elderly are predisposed to bleeding due to normal cerebral atrophy related to aging, stretching the bridging veins from the dura. Prognosis in ASDH is associated with age, time from injury to treatment, presence of pupillary abnormalities, Glasgow Coma Score (GCS) or motor score on admission, immediate coma or lucid interval, computerized tomography findings (haematoma volume, degree of midline shift, associated intradural lesion, compression of basal cisterns), post-operative intracranial pressure and type of surgery. Advancing age is known to be a determinant of outcome in head injury. The authors present the results of a retrospective study carried out in Beaumont Hospital, Dublin, Ireland's national neurosurgical centre. The aim of this study was to examine the impact of age on outcome in patients with ASDH following severe head injury. Only cases with acute subdural haematoma requiring surgical evacuation were recruited.

Morphometric analysis of Triatoma dimidiata populations (Reduviidae:Triatominae) from Mexico and Northern Guatemala

Triatoma dimidiata is one of the major vectors of Chagas disease in Latin America. Its range includes Mexico, all countries of Central America, Colombia, and Ecuador. In light of recent genetic analysis suggesting that the possible origin of this species is the Yucatan peninsula, we have analyzed populations from the state of Yucatan, San Luis Potosi, and Veracruz in Mexico, and a population from the southern region of the Yucatan peninsula located in Northern Guatemala, the region of El Peten. Classical morphometry including principal component, discriminant, sexual dimorphism, and wing asymmetry was analyzed. San Luis Potosi and Veracruz populations were indistinguishable while clearly separate from Yucatan and Peten populations. Despite important genetic differences, Yucatan and Peten populations were highly similar. Yucatan specimens were the smallest in size, while females were larger than males in all populations. Only head characters were necessary to distinguish population level differences, although wing fluctuating asymmetry was present in all populations. These results are discussed in light of recent findings suggesting genetic polymorphism in most populations of Triatoma dimidiata south of Chiapas to Ecuador.

Dexamethasone therapy and cortisol excretion in severe pediatric head injury.

Glucocorticoids are used in an attempt to reduce brain edema secondary to head injury. Nevertheless, their usefulness remains uncertain and contradictory. In a randomized study of 24 children with severe head injury, urinary free cortisol was measured by radioimmunoassay. Twelve patients (group 1) received dexamethasone and 12 (group 2) did not. All patients were treated with a standardized regimen. In group 1 there was complete suppression of endogenous cortisol production. In group 2 free cortisol was up to 20-fold higher than under basal conditions and reached maximum values on days 1-3. Since the excretion of cortisol in urine reflects the production rate closely and is not influenced by liver function and barbiturates, the results in group 2 show that the endogenous production of steroids is an adequate reaction to severe head injury. Exogenous glucocorticoids are thus unlikely to have any more beneficial effects than endogenous cortisol.

The Size of the Problem: NAO Report - Tackling Obesity in England

Powerpoint presentation by Rob Pridequx from the National Audit office

Genetic structure of Triatoma venosa (Hemiptera: Reduviidae): molecular and morphometric evidence

Triatoma venosa presents a restricted geographical distribution in America and is considered as a secondary vector of Chagas disease in Colombia and Ecuador. A total of 120 adult insects were collected in domestic and peridomestic habitats in an endemic area of the department of Boyacá, Colombia, in order to determine their genetic structure through morphometric and molecular techniques. The head and wings of each specimen were used for the analyses of size, shape, and sexual dimorphism. A significant sexual dimorphism was found, although no differences in size among the studied groups were detected. Differences were found in the analyzed structures except for male heads. DNA was extracted from the legs in order to carry out the internal transcriber space-2 (ITS-2) amplification and the randon amplified polymorphic DNA (RAPD) analyses. Length polymorphisms were not detected in the ITS-2. Fst and Nm values were estimated (0.047 and 3.4, respectively). The high genetic flow found among the insects captured in the domicile and peridomiciliary environment does not permit a genetic differentiation, thus establishing the peridomicile as an important place for epidemiological surveillance.

High constant incidence rates of second primary cancers of the head and neck: a pooled analysis of 13 cancer registries.

Scanty data are available on the incidence (i.e., the absolute risk) of second cancers of the head and neck (HN) and its pattern with age. We investigated this issue using data from a multicentric study of 13 population-based cancer registries from Europe, Canada, Australia and Singapore for the years 1943-2000. A total of 99,257 patients had a first primary HN cancer (15,985 tongue, 22,378 mouth, 20,758 pharyngeal, and 40,190 laryngeal cancer), contributing to 489,855 person-years of follow-up. A total of 1,294 of the patients (1.3%) were diagnosed with second HN cancers (342 tongue, 345 mouth, 418 pharynx and 189 larynx). Male incidence rates of first HN cancer steeply increased from 0.68/100,000 at age 30-34 to 46.2/100,000 at age 70-74, and leveled off at older age; female incidence increased from 0.50/100,000 at age 30-34 to 16.5/100,000 at age 80-84. However, age-specific incidence of second HN cancers after a first HN cancer in men was around 200-300/100,000 between age 40-44 and age 70-74 and tended to decline at subsequent ages (150/100,000 at age 80-84); in women, incidence of second HN cancers was around 200-300/100,000 between age 45-49 and 80-84. The patterns of age-specific incidence were consistent for different subsites of second HN cancer and sexes; moreover, they were similar for age-specific incidence of first primary HN cancer in patients who subsequently developed a second HN cancer. The incidence of second HN cancers does not increase with age, but remains constant, or if anything, decreases with advancing age.

Coevolution of adaptive technology, maladaptive culture and population size in a producer-scrounger game.

Technology (i.e. tools, methods of cultivation and domestication, systems of construction and appropriation, machines) has increased the vital rates of humans, and is one of the defining features of the transition from Malthusian ecological stagnation to a potentially perpetual rising population growth. Maladaptations, on the other hand, encompass behaviours, customs and practices that decrease the vital rates of individuals. Technology and maladaptations are part of the total stock of culture carried by the individuals in a population. Here, we develop a quantitative model for the coevolution of cumulative adaptive technology and maladaptive culture in a 'producer-scrounger' game, which can also usefully be interpreted as an 'individual-social' learner interaction. Producers (individual learners) are assumed to invent new adaptations and maladaptations by trial-and-error learning, insight or deduction, and they pay the cost of innovation. Scroungers (social learners) are assumed to copy or imitate (cultural transmission) both the adaptations and maladaptations generated by producers. We show that the coevolutionary dynamics of producers and scroungers in the presence of cultural transmission can have a variety of effects on population carrying capacity. From stable polymorphism, where scroungers bring an advantage to the population (increase in carrying capacity), to periodic cycling, where scroungers decrease carrying capacity, we find that selection-driven cultural innovation and transmission may send a population on the path of indefinite growth or to extinction.

Genome size rather than content might affect call properties in toads of three ploidy levels (Anura: Bufonidae: Bufo viridis subgroup).

In vertebrates, genome size has been shown to correlate with nuclear and cell sizes, and influences phenotypic features, such as brain complexity. In three different anuran families, advertisement calls of polyploids exhibit longer notes and intervals than diploids, and difference in cellular dimensions have been hypothesized to cause these modifications. We investigated this phenomenon in green toads (Bufo viridis subgroup) of three ploidy levels, in a different call type (release calls) that may evolve independently from advertisement calls, examining 1205 calls, from ten species, subspecies, and hybrid forms. Significant differences between pulse rates of six diploid and four polyploid (3n, 4n) green toad forms across a range of temperatures from 7 to 27 °C were found. Laboratory data supported differences in pulse rates of triploids vs. tetraploids, but failed to reach significance when including field recordings. This study supports the idea that genome size, irrespective of call type, phylogenetic context, and geographical background, might affect call properties in anurans and suggests a common principle governing this relationship. The nuclear-cell size ratio, affected by genome size, seems the most plausible explanation. However, we cannot rule out hypotheses under which call-influencing genes from an unexamined diploid ancestral species might also affect call properties in the hybrid-origin polyploids.

The pocket guide to minding your head

This pocket-sized leaflet advises young men on the steps they can take to promote good mental health, such as keeping active, talking through problems and taking time to relax.�

Mind your head, a student guide to mental health

This booklet is full of practical tips and information on managing stress and achieving and maintaining positive mental health and emotional wellbeing. It also contains a comprehensive list of helpful local organisations and websites. The booklet targets first year students at university and further and higher education colleges as the transition from school to further education can be a very stressful time. It��'s distributed at universities and colleges during freshers week and is also available on request from student services or the students union at many campuses.

Description of a new phlebotomine species, Evandromyia gaucha sp. nov. (Diptera: Psychodidae: Phlebotominae), from Rio Grande do Sul, Brazil

The present paper describes a new phlebotomine species, Evandromyia gaucha sp. nov., based on seven females found in the municipality of Caçapava do Sul, state of Rio Grande do Sul, Brazil. The new species belong to rupicola series and differs from other sand flies of the genus Evandromyia due to the presence of a rounded spermatheca head with its size very close to that of the spermatheca body.

Cessation of alcohol drinking, tobacco smoking and the reversal of head and neck cancer risk.

BACKGROUND: Quitting tobacco or alcohol use has been reported to reduce the head and neck cancer risk in previous studies. However, it is unclear how many years must pass following cessation of these habits before the risk is reduced, and whether the risk ultimately declines to the level of never smokers or never drinkers. METHODS: We pooled individual-level data from case-control studies in the International Head and Neck Cancer Epidemiology Consortium. Data were available from 13 studies on drinking cessation (9167 cases and 12 593 controls), and from 17 studies on smoking cessation (12 040 cases and 16 884 controls). We estimated the effect of quitting smoking and drinking on the risk of head and neck cancer and its subsites, by calculating odds ratios (ORs) using logistic regression models. RESULTS: Quitting tobacco smoking for 1-4 years resulted in a head and neck cancer risk reduction [OR 0.70, confidence interval (CI) 0.61-0.81 compared with current smoking], with the risk reduction due to smoking cessation after >/=20 years (OR 0.23, CI 0.18-0.31), reaching the level of never smokers. For alcohol use, a beneficial effect on the risk of head and neck cancer was only observed after >/=20 years of quitting (OR 0.60, CI 0.40-0.89 compared with current drinking), reaching the level of never drinkers. CONCLUSIONS: Our results support that cessation of tobacco smoking and cessation of alcohol drinking protect against the development of head and neck cancer.