Assessment of vegetation structure and human impacts in the protected area of Alédjo (Togo)

Protected areas constitute strategy for biodiversity conservation. Unfortunately, these sanctuaries of biodiversity are submitted to a high human pressure in Togo. This study carried out in the Alédjo protected area, aimed to make an analysis of various forms of human footprints and their impact on its plant resources. Methodological approach was based on forest inventory completed by inquiries. Ninety‐four wooded species belonging to 35 families were counted. Floristic data analysis showed that seven species: Isoberlinia doka Craib & Stapf, Daniellia oliveri (Rolfe) Hutch. & Dalz., Berlinia grandiflora (Vahl) Hutch. & Dalz., Pterocarpus erinaceus Poir., Zanha golungensis Hiern, Khaya senegalensis (Desv.) A. Juss., Pentadesma butyracea Sabine was prominent. Five vegetation types were identified: riparian forests, dry forests, open forests, savanna woodlands, tree/shrub savannas with variable structural characteristics. The diversity indices in these plant communities are well significant and indicate a good distribution of species in the area. Several human activities such as fuel wood, fruits and medicinal plants gathering, carbonization, pasture were found within the protected area. Local authorities and associations are involved in the management of the protected area, but the participation of local populations needs to be improved.     

The ecological-evolutionary interplay: density-dependent sexual selection in a migratory songbird

Little is understood about how environmental heterogeneity influences the spatial dynamics of sexual selection. Within human-dominated systems, habitat modification creates environmental heterogeneity that could influence the adaptive value of individual phenotypes. Here, we used the gray catbird to examine if the ecological conditions experienced in the suburban matrix (SM) and embedded suburban parks (SP) influence reproductive strategies and the strength of sexual selection. Our results show that these habitats varied in a key ecological factor, breeding density. Moreover, this ecological factor was closely tied to reproductive strategies such that local breeding density predicted the probability that a nest would contain extra-pair offspring. Partitioning reproductive variance showed that while within-pair success was more important in both habitats, extra-pair success increased the opportunity for sexual selection by 39% at higher breeding densities. Body size was a strong predictor of relative reproductive success and was under directional selection in both habitats. Importantly, our results show that the strength of sexual selection did not differ among habitats at the landscape scale but rather that fine-scale variation in an ecological factor, breeding density, influenced sexual selection on male phenotypes. Here, we document density-dependent sexual selection in a migratory bird and hypothesize that coarse-scale environmental heterogeneity, in this case generated by anthropogenic habitat modification, changed the fine-scale ecological conditions that drove the spatial dynamics of sexual selection.     

Trends in Asthma-Related Direct Medical Costs from 2002 to 2007 in British Columbia,Canada: A Population Based-Cohort Study

Background

Asthma-related health resource use and costs may be influenced by increasing asthma prevalence, changes to asthma management guidelines, and new medications over the last decade. The objective of this work was to analyze direct asthma-related medical costs, and trends in total and per-patient costs of hospitalizations, physician visits, and medications.

Methods

A cohort of asthma patients from British Columbia (BC), Canada, was created. Asthma patients were identified using a validated case definition. Costs for hospitalizations, physician visits, and medications were calculated from billing records (in 2008 Canadian dollars). Trends in total and per-patient costs over the study period were analyzed using Generalized Linear Models.

Results

398,235 patients satisfied the asthma case definition (mid-point prevalence 8.0%). Patients consumed $315.9 million (M) in direct asthma-related health resources between 2002 and 2007. Hospitalizations, physician visits, and medication costs accounted for 16.0%, 15.7% and 68.2% of total costs, respectively. Cost of asthma increased from $49.4 M in 2002 to $54.7 M in 2007. Total annual costs attributable to hospitalizations and physician visits decreased (−39.8% and −25.5%, respectively; p<0.001), while medication costs increased (+38.7%; p<0.001).

Interpretation

This population-based analysis shows that the total direct cost of asthma in BC has increased since 2002, mainly due to a rise in asthma prevalence and cost of medication. Combination therapy with inhaled corticosteroids/long-acting beta-agonists has become a significant component of the cost of asthma. Although billing records capture only a fraction of the true burden of asthma, the simultaneous increase in medication costs and reductions in hospitalization and physician visit costs provides valuable insight for policy makers into the shifts in asthma-related resource use.     

Future Impact of Various Interventions on the Burden of COPD in Canada: A Dynamic Population Model

Background

Chronic obstructive pulmonary disease (COPD) is a growing economic burden worldwide. Smoking cessation is thought to be the single most effective way of reducing the economic burden of COPD. The impact of other strategies such as interventions that predict risk of disease, reduce progression of disease, or reduce exacerbations has not been systematically studied.

Objectives

We estimated the economic and clinical burden of COPD over the next 25 years in Canada and the impact of three potential interventions (screening test for predisposition to COPD, new drugs to avoid progression into more severe disease stages, and predictive test for exacerbations) on COPD burden.

Methods

Using a dynamic simulation model, we projected the total burden of COPD (cost, morbidity, and mortality) from 2011 to 2035 using the population of Canada as a case study. The model stratified population based on sex, age, smoking status, respiratory symptoms, and their COPD stage. The cost and quality adjusted life years (QALYs) associated with each intervention were estimated.

Results

The model indicates that annual societal cost of COPD is $4.52 billion (B) Canadian dollars in 2011 and will reach $3.61B ($7.33B undiscounted) per year in 2035. Over the next 25 years, COPD will be responsible for approximately $101.4B in societal costs ($147.5B undiscounted) and 12.9 million QALYs lost (19.0 million undiscounted). Our results suggested that the best strategy to reduce the financial burden of COPD is by reducing exacerbations. Smoking cessation, while it is the cornerstone of COPD prevention, has only a modest effect in attenuating the financial burden of COPD over the next 25 years in Western countries such as Canada.

Conclusion

Our data suggest that any intervention that can reduce the number of exacerbations has a substantial impact on morbidity and costs of COPD and should be considered in conjunction with the ongoing efforts to reduce smoking rates.     

Phylogeography of a widespread North American migratory songbird (Setophaga ruticilla)

Genetic analyses for many widespread North American species have revealed significant east-west differentiation, indicating that many survived through the Pleistocene in 2 glacial refugia-1 in the eastern and 1 in the western part of the continent. It remains unclear, however, whether other areas may have served as important glacial refugia. Moreover, many such species exhibit widespread genetic similarity within eastern and western regions because of recent expansion from small refugial populations, making it difficult to evaluate current-day levels of gene flow. In this study, we used mitochondrial DNA (mtDNA) control region sequence and amplified fragment length polymorphism markers to survey genetic variation in a widespread migratory bird, the American redstart (Setophaga ruticilla). mtDNA analyses revealed a pattern that contrasts with that found for most other widespread species studied to date: most redstart populations across North America appear to have spread out from a single glacial refugium, possibly located in the southeastern United States, whereas populations in far-eastern Canada may have survived in a second glacial refugium located on the now-submerged Atlantic coastal shelf off the coast of Newfoundland. A pattern of isolation by distance in mtDNA suggested some constraints on current-day gene flow among extant redstart populations. This study thus reveals a recent evolutionary history for this species that differs from that of most other widespread North American passerines and provides evidence for limited gene flow in a species with potentially large dispersal distances.     

Myofibroblast - like cells and liver fibrogenesis: Emerging concepts in a rapidly moving scenario

Fibrotic progression of chronic liver diseases of different aetiology to the common advanced-stage of cirrhosis can be envisaged as a dynamic and highly integrated cellular response to chronic liver injury. Liver fibrosis is accompanied by perpetuation of liver injury, chronic hepatitis and persisting activation of tissue repair mechanisms, leading eventually to excess deposition of ECM components. Liver fibrogenesis (i.e., the process) is sustained by populations of highly proliferative, pro-fibrogenic and contractile MFs that, according to current literature, originate by a process of activation involving perisinusoidal HSC, portal fibroblasts and even bone marrow-derived MSC. In this short review emerging concepts in hepatic fibrogenesis and related molecular mechanisms, as provided by recent experimental and clinical studies, are presented.     

Catalase T and Cu,Zn-superoxide dismutase in the acetic acid-induced programmed cell death in Saccharomyces cerevisiae

To investigate the role of catalase and superoxide dismutase (SOD) in the acetic acid (AA) induced yeast programmed cell death (AA-PCD), we compared Saccharomyces cerevisiae cells (C-Y) and cells individually over-expressing catalase T (CTT1-Y) and Cu,Zn-SOD (SOD1-Y) with respect to cell survival, hydrogen peroxide (H2O2) levels and enzyme activity as measured up to 200 min after AA treatment. AA-PCD does not occur in CTT1-Y, where H2O2 levels were lower than in C-Y and the over-expressed catalase activity decreased with time. In SOD1-Y, AA-PCD was exacerbated; high H2O2 levels were found, SOD activity increased early, remaining constant en route to AA-PCD, but catalase activity was strongly reduced.     

Bovine serum amine oxidase and spm potentiate docetaxel and interferon-alpha effects in inducing apoptosis on human cancer cells through the generation of oxidative stress

It was previously demonstrated that bovine serum amine-oxidase (BSAO) and SPM (SPM) addition to cancer cells induces cell growth inhibition and over-run the multi-drug resistance (MDR) phenotype through the oxidative stress caused by polyamine metabolites. In this study, it is reported that BSAO/SPM enzymatic system antagonizes the survival pathway induced by either docetaxel (DTX) or interferon alpha (IFNalpha) in human epidermoid cancer KB cells. The combination of BSAO/SPM with either DTX or IFNalpha had a synergistic effect on cell growth inhibition through apoptosis in both human epidermoid KB and breast cancer MCF-7 cell lines. The effects of the BSAO/SPM-DTX combination on apoptosis were caspase 3 and 9-dependent and were paralleled by the enhancement of intracellular O(2-), nitric oxide levels and of lipo-oxidation. The scavenger moiety N-acetyl-cysteine antagonized the effects on apoptosis and cell growth inhibition induced by the combination suggesting a role of the oxidative products of SPM. These effects occurred together with a decrease of the physiological scavenger MnSOD and an increase of both p38 kinase activity and DNA damage. The results suggest that DTX and IFNalpha could sensitize tumour cells to the oxidative stress and apoptosis induced by BSAO/SPM through the induction of a survival ras-dependent pathway and the consequent elevation of the intracellular polyamine pool. These data allow the design of new therapeutic strategy based on the use of this combination in human neoplasms.     

The HL-60 model for the interaction of human macrophages with the Legionnaires' disease bacterium

The facultative intracellular pathogen, Legionella pneumophila, multiplies within and kills human monocytes and alveolar macrophages. We show that L. pneumophila strain Philadelphia-1 infects, multiplies within and kills the promyelocyte HL-60 cell line after its differentiation into macrophage-like cells. The characteristics of the interaction between L. pneumophila and differentiated HL-60 cells closely resemble those between L. pneumophila and human peripheral blood monocytes. With both cell types, C receptors and serum C mediate attachment of L. pneumophila, which are taken up by coiling phagocytosis. The replicative phagosome is lined with ribosomes; intracellular multiplication is iron-dependent; and replicating bacteria ultimately destroy the host cell. As in human monocytes, an avirulent mutant derivative of L. pneumophila Philadelphia-1, 25D, does not replicate in and is not cytopathic for differentiated HL-60 cells. Differentiated HL-60 cells therefore provide a convenient and faithful model for the study of L. pneumophila-mononuclear phagocyte interaction.