Intra-Group Competition and Inter-Group Conflict: An Application to Northern Ireland

This paper reviews four economic theories of leadership selection in conflictual settings. The first of these by Cukierman and Tomassi (1998) labeled the ‘information rationale’, argues that hawks may actually be necessary to initiate peace agreements. The second labeled the ‘bargaining rationale’ borrowing from Hamlin and Jennings (2007) agrees with the conventional wisdom that doves are more likely to secure peace, but post-conflict there are good reasons for hawks to be rationally selected. The third found in Jennings and Roelfsema (2008) is labeled the social psychological rationale. This captures the idea of a competition over which group can form the strongest identity, so can apply to group choices which do not impinge upon bargaining power. As in the bargaining rationale, dove selection can be predicted during conflict, but hawk selection post-conflict. Finally, the expressive rationale is discussed which predicts that regardless of the underlying structure of the game (informational, bargaining, psychological) the large group nature of decision-making by making individual decision makers non-decisive in determining the outcome of elections may cause them to make choices based primarily on emotions which may be invariant with the mode of group interaction, be it conflictual or peaceful. Finally, the paper analyses the extent to which the theories can throw light on Northern Ireland electoral history over the last 25 years.

Seasonal distribution and diel biting patterns of culicine mosquitoes in Costa Marques, Rondônia, Brazil

A study of peridomestic man-biting culicines in the Amazon Basin was conducted from January through December, 1987. Fifteen species of mosquitoes from six genera were collected by volunters in all-night human-bait indoor and outdoor collections at five hoses in and near the town of Costa Marques, Rondônia, Brazil. Culex quinquefasciatus and members of the Mansonia titillans/indubitans Group comprised 61 and 33%, respectively, of all culcines collected from human-bait outside houses and 62 and 35%, respectively, of those collected from volunteers inside houses in the town. In rural areas, Cx. quinquefasciatus was less abundant and only comprised 2 and 5% of the culcines, respectively, collected inside and outside houses. Mansonia titillans/indubitans Group comprised 75% and 86% of the culicines collected inside and outside houses, respectively, from rural residences. Culex quinquefasciatus and members of Mn. titillans/indubitans Group were more endophilic than other culcines collected. Nocturnal and seasonal biting rhythms for the more common culcines are described

Kinetics of antigen specific and non-specific polyclonal B-cell responses during lethal Plasmodium yoelii malaria

In order to study the kinetics and composition of the polyclonal B-cell activation associated to malaria infection, antigen-specific and non-specific B-cell responses were evaluated in the spleens of mice infected with Plasmodium yoelii 17 XL or injected with lysed erythrocytes or plasma from P. yoelii infected mice or with P. falciparum culture supernatants. Spleen/body weigth ratio, numbers of nucleated spleen cells and Immunoglobulin-containing and Immunoglobulin-secreting cells increased progressively during the course of infection,in parallel to the parasitemia. A different pattern of kinetics was observed when anti-sheep red blood cell and anti-trinitrophenylated-sheep red blood cell plaque forming cells response were studied: maximum values were observed at early stages of infection, whereas the number of total Immunoglobulin-containing and Immunoglobulin-secreting cells were not yet altered. Conversely, at the end of infection, when these latter values reached their maximum, the anti-sheep red blood cell and anti-trinitrophenylated-sheep red blood cell specific responses were normal or even infranormal. In mice injected with Plasmodium-derived material, a higher increase in antigen-specific PFC was observed, as compared to the increase of Immunoglobulin-containing and Immunoglobulin-secreting cell numbers. This suggested a "preferential" (antigen-plus mitogen-induced) stimulation of antigen-specific cells rather than a generalized non-specific (mitogen-induced) triggering of B-lymphocytes. On the basis of these and previous results, it is suggested that polyclonal B-cell activation that takes place during the course of infection appears as a result of successive waves of antigen-specific B-cell activation.

Female- and male-specific signals of quality in the barn owl

Most bird studies of female signalling have been confined to species in which females display a male-ornament in a vestigial form. However, a great deal of benefit may be gained from considering phenotypic traits that are specific to females. This is because (1) sex-specific traits may signal sex-specific qualities and (2) females may develop a male-ornament not because they are selected to do so, but because fathers transmit to daughters the underlying genes for its expression (genetic correlation between the sexes). We investigated these two propositions in the barn owl Tyto alba, a species in which male plumage is lighter in colour and less marked with black spots than that of females. Firstly, we present published evidence that female plumage spottiness reflects parasite resistance ability. We also show that male plumage coloration is correlated with reproductive success, male feeding rate and heart mass. Secondly, cross-fostering experiments demonstrate that plumage coloration and spottiness are genetically correlated between the sexes. This implies that if a given trait value is selected in one sex, the other sex will indirectly evolve towards a similar value. This prediction is supported by the observation that female plumage coloration and spottiness resembled that of males, in comparisons at the level of Tyto alba alba populations, Tyto alba subspecies and Tyto species. Our results therefore support the hypothesis that sex-specific traits signal sex-specific qualities and that a gene for a sex-specific trait can be expressed in the other sex as the consequence of a genetic correlation between the sexes.

Species and Strain-specific Typing of Cryptosporidium Parasites in Clinical and Environmental Samples

Cryptosporidiosis has recently attracted attention as an emerging waterborne and foodborne disease as well as an opportunistic infection in HIV infected individuals. The lack of genetic information, however, has resulted in confusion in the taxonomy of Cryptosporidium parasites and in the development of molecular tools for the identification and typing of oocysts in environmental samples. Phylogenetic analysis of the small subunit ribosomal RNA (SSU rRNA) gene has shown that the genus Cryptosporidium is comprised of several distinct species. Our data show the presence of at least four species: C. parvum, C. muris, C. baileyi and C. serpentis (C. meleagridis, C. nasorum and C. felis were not studied). Within each species, there is some sequence variation. Thus, various genotypes (genotype 1, genotype 2, guinea pig genotype, monkey genotype and koala genotype, etc.) of C. parvum differ from each other in six regions of the SSU rRNA gene. Information on polymorphism in Cryptosporidium parasites has been used in the development of species and strain-specific diagnostic tools. Use of these tools in the characterization of oocysts various samples indicates that C. parvum genotype 1 is the strain responsible for most human Cryptosporidium infections. In contrast, genotype 2 is probably the major source for environmental contamination of environment, and has been found in most oysters examined from Chesapeake Bay that serve as biologic monitors of surface water. Parasites of Cryptosporidium species other than C. parvum have not been detected in HIV+ individuals, indicating that the disease in humans is caused only by C. parvum.

Age-related worm load and worm fecundity patterns in human populations, as indicated by schistosome circulating antigens

Recently, our group determined the relationship between serum CAA levels and fecal egg counts in two foci with very intense Schistosoma mansoni transmission: Maniema (Zaire), an area endemic for S. mansoni since several decades, and Ndombo (Senegal), where transmission has only been established since a few years. The objective was to study and compare age-related worm load and worm fecundity patterns in these two different endemic settings. Here, we will summarize the most important findings and conclusions of this study.

Novel H3K4me3 marks are enriched at human- and chimpanzee-specific cytogenetic structures.

Human and chimpanzee genomes are 98.8% identical within comparable sequences. However, they differ structurally in nine pericentric inversions, one fusion that originated human chromosome 2, and content and localization of heterochromatin and lineage-specific segmental duplications. The possible functional consequences of these cytogenetic and structural differences are not fully understood and their possible involvement in speciation remains unclear. We show that subtelomeric regions-regions that have a species-specific organization, are more divergent in sequence, and are enriched in genes and recombination hotspots-are significantly enriched for species-specific histone modifications that decorate transcription start sites in different tissues in both human and chimpanzee. The human lineage-specific chromosome 2 fusion point and ancestral centromere locus as well as chromosome 1 and 18 pericentric inversion breakpoints showed enrichment of human-specific H3K4me3 peaks in the prefrontal cortex. Our results reveal an association between plastic regions and potential novel regulatory elements.

Segregation in a mycorrhizal fungus alters rice growth and symbiosis-specific gene transcription

Arbuscular mycorrhizal fungi (AMF) form symbioses with the majority of plants, improving plant nutrition and diversity. Evidence exists suggesting that AMF contain populations of genetically different nucleotypes coexisting in a common cytoplasm. This potentially has two important consequences for their genetics. First, by random distribution of nuclei at spore formation, new offspring of an AMF could receive different complements of nucleotypes compared to the parent or siblings-we consider this as segregation. Second, genetic exchange between AMF would allow the mixing of nuclei, altering nucleotype diversity in new spores. Because segregation was assumed not to occur and genetic exchange has only recently been demonstrated, no attempts have been made to test whether this affects the symbiosis with plants. Here, we show that segregation occurs in the AMF Glomus intraradices and can enhance the growth of rice up to five times, even though neither parental nor crossed AMF lines induced a positive growth response. This process also resulted in an alteration of symbiosis-specific gene transcription in rice. Our results demonstrate that manipulation of AMF genetics has important consequences for the symbiotic effects on plants and could be used to enhance the growth of globally important crops.

Routes of administration of cannabis used for nonmedical purposes and associations with patterns of drug use.

PURPOSE: Little is known regarding cannabis administration routes for nonmedical use-that is, its delivery methods (e.g., joints, water pipe, food). Therefore, we examined the prevalence rates of different cannabis delivery methods and assessed the relationship of the distinct administration routes with problematic drug use. Subgroups of cannabis users were also investigated (i.e., "pure" cannabis users, previously described as employing a harmless route of administration, and water pipe users, previously described as using a harmful route of administration). METHODS: As part of the Cohort Study on Substance Use Risk Factors, 1,763 cannabis users answered questions concerning their drug use (i.e., routes of administration, problematic cannabis use, other illicit drug use). Descriptive statistics, latent class analysis, correlations and t-tests were assessed. RESULTS: The main administration route was "joints with tobacco"; other routes of administration had prevalence rates from 23.99% to 38.23%. In addition, increasing the number of administration routes was associated with more problematic cannabis use, as well as heavier illicit drug use. Water pipes without tobacco were especially linked to heavy drug use patterns, whereas "pure" cannabis use seemed less harmful. CONCLUSIONS: Our findings highlighted that diversification in routes of administration can be associated with heavier illicit drug use. This was especially true for water pipe users, whereas "pure" cannabis users, who did not mix cannabis with tobacco, were an exception. Indeed, these results may be useful for future preventive programs, which may need to focus on those who have diversified routes of administration for cannabis.

Quantifying network properties in multi-electrode recordings: spatiotemporal characterization and inter-trial variation of evoked gamma oscillations in mouse somatosensory cortex in vitro.

Linking the structural connectivity of brain circuits to their cooperative dynamics and emergent functions is a central aim of neuroscience research. Graph theory has recently been applied to study the structure-function relationship of networks, where dynamical similarity of different nodes has been turned into a "static" functional connection. However, the capability of the brain to adapt, learn and process external stimuli requires a constant dynamical functional rewiring between circuitries and cell assemblies. Hence, we must capture the changes of network functional connectivity over time. Multi-electrode array data present a unique challenge within this framework. We study the dynamics of gamma oscillations in acute slices of the somatosensory cortex from juvenile mice recorded by planar multi-electrode arrays. Bursts of gamma oscillatory activity lasting a few hundred milliseconds could be initiated only by brief trains of electrical stimulations applied at the deepest cortical layers and simultaneously delivered at multiple locations. Local field potentials were used to study the spatio-temporal properties and the instantaneous synchronization profile of the gamma oscillatory activity, combined with current source density (CSD) analysis. Pair-wise differences in the oscillation phase were used to determine the presence of instantaneous synchronization between the different sites of the circuitry during the oscillatory period. Despite variation in the duration of the oscillatory response over successive trials, they showed a constant average power, suggesting that the rate of expenditure of energy during the gamma bursts is consistent across repeated stimulations. Within each gamma burst, the functional connectivity map reflected the columnar organization of the neocortex. Over successive trials, an apparently random rearrangement of the functional connectivity was observed, with a more stable columnar than horizontal organization. This work reveals new features of evoked gamma oscillations in developing cortex.

Cardiorespiratory responses during running and sport-specific exercises in handball players

To determine whether a 4-a-side handball (HB) game is an appropriate aerobic stimulus to reach and potentially enhance maximal oxygen uptake (V O(2)max), and whether heart rate (HR) is a valid index of V O(2) during a handball game. Nine skilled players (21.0+/-2.9 yr) underwent a graded maximal aerobic test (GT) where V O(2)max and HR-V O(2) relationship were determined. V O(2), HR and blood lactate ([La](b)) were recorded during a 2 x 225 s (interspersed with 30s rest) 4-a-side handball game and were compared to those measured during an 480-s running intermittent exercise (IE). Mean V O(2) tended to be higher in handball compared to IE (93.9+/-8.5 vs. 87.6+/-7.4% O(2)max, p=0.06), whereas HR was similar (92.3+/-4.9 vs. 93.9+/-3.9% of the peak of HR, p=0.10). [La](b) was lower for handball than for IE (8.9+/-3.5 vs. 11.6+/-2.1 mmol l(-1), p=0.04). Time spent over 90% of V O(2)max was higher for handball than for IE (336.1+/-139.6s vs. 216.1+/-124.7s; p=0.03). The HR-V O(2) relationship during GT was high (r(2)=0.96, p<0.001) but estimated V O(2) from HR was lower to that measured (p=0.03) in handball, whereas there was no difference in IE. 4-a-side handball game can be used as a specific alternative to IE for enhancing aerobic fitness in handball players. Nevertheless, the accuracy of HR measures for estimating V O(2) during handball is poor.

Serogroups, K1 antigen, and antimicrobial resistance patterns of Aeromonas spp. strains isolated from different sources in Mexico

A total of 221 strains of Aeromonas species isolated in Mexico from clinical (161), environmental (40), and food (20) samples were identified using the automated system bioMérieux-Vitek®. Antisera for serogroups O1 to 044 were tested using the Shimada and Sakazaki scheme. The K1 antigen was examined using as antiserum the O7:K1C of Escherichia coli. Besides, we studied the antimicrobial patterns according to Vitek AutoMicrobic system. Among the 161 clinical strains 60% were identified as A. hydrophila, 20.4% as A. caviae, and 19.25% as A. veronii biovar sobria. Only A. hydrophila and A. veronii biovar sobria were found in food (55 and 90% respectively) and environmental sources (45 and 10% respectively). Using "O" antisera, only 42.5% (94/221) of the strains were serologically identified, 55% (121/221) were non-typable, and 2.5% (6/221) were rough strains. Twenty-two different serogroups were found, O14, O16, O19, O22, and O34 represented 60% of the serotyped strains. More than 50% of Aeromonas strain examined (112/221) expressed K1 encapsulating antigen; this characteristic was predominant among Aeromonas strains of clinical origin. Resistance to ampicillin/sulbactam and cephazolin was detected in 100 and 67% of Aeromonas strain tested for their susceptibility to antibiotics. In conclusion, antibiotic-resistant Aeromonas species that possess the K1 encapsulating antigen and represent serogroups associated with clinical syndrome in man are not uncommon among Aeromonas strains isolated from clinical, food and environmental sources in Mexico.

Association of socioeconomic status with overall and cause specific mortality in the republic of seychelles : results from a cohort study in the african region

BACKGROUND: Low socioeconomic status (SES) is consistently associated with higher mortality in high income countries. Only few studies have assessed this association in low and middle income countries, mainly because of sparse reliable mortality data. This study explores SES differences in overall and cause-specific mortality in the Seychelles, a rapidly developing small island state in the African region. METHODS: All deaths have been medically certified over more than two decades. SES and other lifestyle-related risk factors were assessed in a total of 3246 participants from three independent population-based surveys conducted in 1989, 1994 and 2004. Vital status was ascertained using linkage with vital statistics. Occupational position was the indicator of SES used in this study and was assessed with the same questions in the three surveys. RESULTS: During a mean follow-up of 15.0 years (range 0-23 years), 523 participants died (overall mortality rate 10.8 per 1000 person-years). The main causes of death were cardiovascular disease (CVD) (219 deaths) and cancer (142 deaths). Participants in the low SES group had a higher mortality risk for overall (HR = 1.80; 95% CI: 1.24-2.62), CVD (HR = 1.95; 1.04-3.65) and non-cancer/non-CVD (HR = 2.14; 1.10-4.16) mortality compared to participants in the high SES group. Cancer mortality also tended to be patterned by SES (HR = 1.44; 0.76-2.75). Major lifestyle-related risk factors (smoking, heavy drinking, obesity, diabetes, hypertension, hypercholesterolemia) explained a small proportion of the associations between low SES and all-cause, CVD, and non-cancer/non-CVD mortality. CONCLUSIONS: In this population-based study assessing social inequalities in mortality in a country of the African region, low SES (as measured by occupational position) was strongly associated with overall, CVD and non-cancer/non-CVD mortality. Our findings support the view that the burden of non-communicable diseases may disproportionally affect people with low SES in low and middle income countries.

Lifetime alcohol use and overall and cause-specific mortality in the European Prospective Investigation into Cancer and nutrition (EPIC) study.

OBJECTIVES To investigate the role of factors that modulate the association between alcohol and mortality, and to provide estimates of absolute risk of death. DESIGN The European Prospective Investigation into Cancer and nutrition (EPIC). SETTING 23 centres in 10 countries. PARTICIPANTS 380 395 men and women, free of cancer, diabetes, heart attack or stroke at enrolment, followed up for 12.6 years on average. MAIN OUTCOME MEASURES 20 453 fatal events, of which 2053 alcohol-related cancers (ARC, including cancers of upper aerodigestive tract, liver, colorectal and female breast), 4187 cardiovascular diseases/coronary heart disease (CVD/CHD), 856 violent deaths and injuries. Lifetime alcohol use was assessed at recruitment. RESULTS HRs comparing extreme drinkers (≥30 g/day in women and ≥60 g/day in men) to moderate drinkers (0.1-4.9 g/day) were 1.27 (95% CI 1.13 to 1.43) in women and 1.53 (1.39 to 1.68) in men. Strong associations were observed for ARC mortality, in men particularly, and for violent deaths and injuries, in men only. No associations were observed for CVD/CHD mortality among drinkers, whereby HRs were higher in never compared to moderate drinkers. Overall mortality seemed to be more strongly related to beer than wine use, particularly in men. The 10-year risks of overall death for women aged 60 years, drinking more than 30 g/day was 5% and 7%, for never and current smokers, respectively. Corresponding figures in men consuming more than 60 g/day were 11% and 18%, in never and current smokers, respectively. In competing risks analyses, mortality due to CVD/CHD was more pronounced than ARC in men, while CVD/CHD and ARC mortality were of similar magnitude in women. CONCLUSIONS In this large European cohort, alcohol use was positively associated with overall mortality, ARC and violent death and injuries, but marginally to CVD/CHD. Absolute risks of death observed in EPIC suggest that alcohol is an important determinant of total mortality.

HIV-1 coreceptor usage and CXCR4-specific viral load predict clinical disease progression during combination antiretroviral therapy

Background: Although combination antiretroviral therapy (cART) dramatically reduces rates of AIDS and death, a minority of patients experience clinical disease progression during treatment. <p>Objective: To investigate whether detection of CXCR4(X4)-specific strains or quantification of X4-specific HIV-1 load predict clinical outcome. Methods: From the Swiss HIV Cohort Study, 96 participants who initiated cART yet subsequently progressed to AIDS or death were compared with 84 contemporaneous, treated nonprogressors. A sensitive heteroduplex tracking assay was developed to quantify plasma X4 and CCR5 variants and resolve HIV-1 load into coreceptor-specific components. Measurements were analyzed as cofactors of progression in multivariable Cox models adjusted for concurrent CD4 cell count and total viral load, applying inverse probability weights to adjust for sampling bias. Results: Patients with X4 variants at baseline displayed reduced CD4 cell responses compared with those without X4 strains (40 versus 82 cells/mu l; P= 0.012). The adjusted multivariable hazard ratio (HR) for clinical progression was 4.8 [95% confidence interval (Cl) 2.3-10.0] for those demonstrating X4 strains at baseline. The X4-specific HIV-1 load was a similarly independent predictor, with HR values of 3.7(95%Cl, 1.2-11.3) and 5.9 (95% Cl, 2.2-15.0) for baseline loads of 2.2-4.3 and > 4.3 log(10)copies/ml, respectively, compared with < 2.2 log(10)copies/ml. Conclusions: HIV-1 coreceptor usage and X4-specific viral loads strongly predicted disease progression during cART, independent of and in addition to CD4 cell count or total viral load. Detection and quantification of X4 strains promise to be clinically useful biomarkers to guide patient management and study HIV-1 pathogenesis.