Coupled forest growth-hydrology modelling as an instrument for the assessment of effects of forest management on hydrology in forested catchments

Abstract. The type and intensity of forest management directly influences regional catchment hydrology. Future forest management must optimise the effects of its practices to achieve sustainable management. With scenario analysis of forestry practices, the effects of different forest utilisation strategies on the hydrology of forested catchments can be temporally and spatially quantified. The approach adopted in this study necessitated the development of an interactive system for the spatially distributed modelling of hydrology in relation to forest stand development. Consequently, a forest growth model was used to simulate stand development assuming various forest management activities. Selected simulated forest growth parameters were entered into the hydrological model to simulate water fluxes under different conditions of forest structure. The approach enables the spatially differentiated quantification of changes in the water regime (e.g. increased evapotranspiration). The results of hydrological simulations in the study area, the Oker catchment (northern Harz Mountains), show that forests contribute to the protection of water systems because they have a balancing effect on the hydrological regime. As scenario simulations also suggest, however, forestry practices can also lead to substantial changes in water budgets of forested catchments. The preservation of the hydrological services of forests requires a sustainable and long-term forest conversion on the basis of current management directives for near natural silviculture. Management strategies on basis of moderate harvesting regimes are preferred because of their limited impact on the water budget

HIV prevalence among female sex workers, drug users and men who have sex with men in Brazil: A Systematic Review and Meta-analysis

<p>Abstract</p> <p>Background</p> <p>The Brazilian response towards AIDS epidemic is well known, but the absence of a systematic review of vulnerable populations ─ men who have sex with men (MSM), female sex workers (FSW), and drug users (DU) remains a main gap in the available literature. Our goal was to conduct a systematic review and meta-analysis of studies assessing HIV prevalence among MSM, FSW and DU, calculating a combined pooled prevalence and summarizing factors associated the pooled prevalence for each group.</p> <p>Methods</p> <p>Nine electronic databases (MEDLINE via PubMed, EMBASE, Cochrane CENTRAL, AIDSLINE, AMED, CINAHL, TOXNET, SciELO, and ISI-Web of Science) were searched for peer-reviewed papers published in English, French, Spanish or Portuguese, from 1999 to 2009. To be included in the review, studies had to measure HIV prevalence and/or incidence as the primary outcome among at least one specific population under analysis.</p> <p>Results</p> <p>The studies targeting the three populations analyzed mostly young participants aged 30 years or less. Among FSW, eight studies were selected (3,625 participants), consistently identifying higher condom use with sexual clients than with occasional and stable partners. The combined HIV prevalence for FSW was 6.2 (95% CI: 4.4-8.3). Ten studies targeting MSM were identified (6,475 participants). Unprotected anal intercourse was commonly reported on those studies, but with great variability according to the nature of the relationship - stable vs. occasional sex partners - and sexual practice - receptive vs. insertive anal sex. Pooled HIV prevalence for MSM was 13.6 (95% CI: 8.2-20.2). Twenty nine studies targeting DU were identified (13,063 participants). Those studies consistently identified injection drug use and syringe/needle sharing as key predictors of HIV-infection, as well as engagement in sex work and male-to-male sex. The combined HIV prevalence across studies targeting DU was 23.1 (95% CI: 16.7-30.2).</p> <p>Conclusions</p> <p>FSW, MSM and DU from Brazil have a much risk of acquiring HIV infection compared to the general population, among which HIV prevalence has been relatively low (~0.6%). Those vulnerable populations should be targeted by focused prevention strategies that provide accurate information, counseling and testing, as well as concrete means to foster behavior change (e.g. access to condoms, drug abuse treatment, and clean syringes in the case of active injecting drug users), tailored to gender and culture-specific needs. Programs that provide these services need to be implemented on public health services throughout the country, in order to decrease the vulnerability of those populations to HIV infection.</p

Erfahrungen mit fasziokutanen Lappen vs. Muskellappen als Defektdeckung an der Fußsohle: Analyse der klinischen und funktionellen Langzeitergebnisse

Introduction: Reconstructing foot defects is a great challenge for plastic surgeons. The clinical and functional results (proprioceptive and exteroceptive) have been inconsistent for defect reconstructions on the weight-bearing and non-weight-bearing area of the foot. Moreover, no final conclusion has been reached about the best type of flap to cover the defect on the weight-bearing area of the sole of the foot. It would be desirable to know whether the clinical and functional results and proprioceptive and exteroceptive qualities on the reconstructed foot provide a reliable indication of the long-term results after reconstruction of defects in the soft tissues in the loaded and unloaded foot.Methods: This retrospective study contains the results from 23 of 39 patients who were operated on between 2001 and 2010. The mean follow-up period was 46.6 months. In 10 patients with a defect cover on the loaded sole of the foot, the clinical and functional parameters were compared for different flap plasties (muscle flap vs. fasciocutaneous flap). In addition, we examined the ability of all 23 patients to differentiate two points, hot and cold, and sharp and blunt, as well as vibration sensitivity in the reconstructed flap area. Results: Nineteen (19) of the 23 patients (82.6%) could be reintegrated in their original occupations. The group of patients with a muscle flap on the loaded sole of the foot (Group 1) were kept in hospital for a much longer period (67.6 days for Group 1 versus 22.2 days for Group 2 with a fascio-cutaneous flap to the loaded sole of the foot). In addition, the operation time was much longer in Group 1 than in Group 2 (485.3 min for Group 1 versus 296.6 min for Group 2). The rate of revision was 66.7% in Group 1 and 28.6% in Group 2. A single patient suffered ulceration in each of the two groups. The proprioceptive and exteroceptive qualities were independent of the type of flap and were essentially the same in the two groups.Discussion: Even though the perioperative parameters (operation-time, hospital-stay, rate of revision) were better in the group of patients with a fasciocutaneous flap to the weight-bearing area of the foot there was no evidence from our data for a clear correlation between ulceration and a loss of sensitivity to vibration. The long-term clinical and neurological results after covering a soft tissue defect in the foot are rather inconsistent, most of our patients (82.6%) could be reintegrated into their original occupations. What is decisive for optimal functional analysis after reconstruction of a soft tissue defect in the foot is not the clinical, perioperative and neurological investigation, but an analysis of the walking cycle with insole-pedobarography.Einleitung: Die Defektrekonstruktion am Fuß ist für den Plastischen Chirurgen eine große Herausforderung. Die Wertigkeit der klinisch-funktionellen Ergebnisse (proprio- und exterozeptiv) zur Beurteilung von Defektrekonstruktionen am belasteten und unbelasteten Fuß ist uneinheitlich. Auch die Frage nach der besten Lappenart zur Defektdeckung an der belasteten Fußsohle ist nicht abschließend geklärt. Welche Aussagekraft in Bezug auf das Langzeitergebnis nach einer Defektrekonstruktion der Fußweichteile im belasteten und unbelasteten Fuß haben klinisch-funktionelle Ergebnisse und proprio- und exterozeptive Qualitäten am rekonstruierten Fuß?Methoden: Die retrospektive Studie beinhaltet die Ergebnisse von 23 aus 39 Patienten, die in den Jahren 2001-2010 operiert worden sind. Die Nachuntersuchungszeit betrug im Durchschnitt 46,6 Monate. Bei 10 Patienten mit einer Defektdeckung zur belasteten Fußsohle wurden klinisch-funktionelle Parameter vergleichend untersucht in Abhängigkeit von der gewählten Lappenplastik. Darüber hinaus haben wir die 2-Punktunterscheidungsfähigkeit, die Warm-Kalt- und die Spitz-Stumpf-Unterscheidungsfähigkeit und das Vibrationsempfinden bei allen 23 Patienten im rekonstruierten Lappenareal untersucht.Ergebnis: 19 von den 23 Patienten (82,6%) konnten in den ursprünglichen Beruf integriert werden. Die Gruppe der Patienten mit einem Muskellappen zur belasteten Fußsohle (Gruppe 1) hatte eine deutlich längere Krankenhausaufenthaltsdauer (67,6 Tage Gruppe 1 vs. 22,2 Tage Gruppe 2 fasziokutaner Lappen zur belasteten Fußsohle). Auch die Operationsdauer war in der Gruppe 1 deutlich länger als in Gruppe 2 (485,3 Minuten Gruppe 1 vs. 296,6 Minuten Gruppe 2). Die Revisionsrate in Gruppe 1 betrug 66,7% und in Gruppe 2 28,6%. Sowohl in der fasziokutanen als auch in der Muskellappengruppe trat bei jeweils einem Patient eine Ulzeration auf. Die Proprio- und exterozeptiven Qualitäten waren unabhängig von der gewählten Lappenart und zeigten weder in der fasziokutanen noch in der Muskellappen-Gruppe eindeutig bessere Ergebnisse.Diskussion: Obwohl die perioperativen Parameter (Operationsdauer, Krankenhausaufenthaltsdauer, Revisionsrate) in der Gruppe der Patienten mit einem fasziokutanen Lappen zur belasteten Fußsohle besser waren, konnten wir eine klare Korrelation zwischen Ulzeration und aufgehobenem Vibrationsempfinden anhand unserer Daten nicht feststellen. Trotz dieser eher uneinheitlichen Ergebnisse in Bezug auf die klinisch-neurologischen Langzeitergebnisse nach einer Weichteildefektdeckung am Fuß zeigte sich, dass ein Großteil unserer Patienten wieder in den ursprünglichen Beruf integriert werden konnte (82,6%). Entscheidend für eine optimierte Funktionsanalyse nach einer Rekonstruktion eines Weichteildefektes am Fuß ist nicht die klinisch-neurologische Untersuchung sondern eine Analyse des Gangzyklus mit insole-Pedobarographie