Individual tree and stand-level carbon and nutrient contents across one rotation of loblolly pine plantations on a reclaimed surface mine

While reclaimed loblolly pine (Pinus taeda L.) plantations in east Texas, USA have demonstrated similar aboveground productivity levels relative to unmined forests, there is interest in assessing carbon (C) and nutrients in aboveground components of reclaimed trees. Numerous studies have previously documented aboveground biomass, C, and nutrient contents in loblolly pine plantations; however, similar data have not been collected on mined lands. We investigated C, N, P, K, Ca, and Mg aboveground contents for first-rotation loblolly pine growing on reclaimed mined lands in the Gulf Coastal Plain over a 32-year chronosequence and correlated elemental rates to stand age, stem growth, and similar data for unmined lands. At the individual tree level, we evaluated elemental contents in aboveground biomass components using tree size, age, and site index as predictor variables. At the stand-level, we then scaled individual tree C and nutrients and fit a model to determine the sensitivity of aboveground elemental contents to stand age and site index. Our data suggest that aboveground C and nutrients in loblolly pine on mined lands exceed or follow similar trends to data for unmined pine plantations derived from the literature. Diameter and height were the best predictors of individual tree stem C and nutrient contents (R ≥ 0.9473 and 0.9280, respectively) followed by stand age (R ≥ 0.8660). Foliage produced weaker relationships across all predictor variables compared to stem, though still significant (P ≤ 0.05). The model for estimating stand-level C and nutrients using stand age provided a good fit, indicating that contents aggrade over time predictably. Results of this study show successful modelling of reclaimed loblolly pine aboveground C and nutrients, and suggest elemental cycling is comparable to unmined lands, thus providing applicability of our model to related systems

Treatment of Acne Keloidalis Nuchae: A Systematic Review of the Literature

Acne keloidalis nuchae (AKN) is a chronic inflammatory condition that leads to fibrotic plaques, papules and alopecia on the occiput and/or nape of the neck. Traditional medical management focuses on prevention, utilization of oral and topical antibiotics, and intralesional steroids in order to decrease inflammation and secondary infections. Unfortunately, therapy may require months of treatment to achieve incomplete results and recurrences are common. Surgical approach to treatment of lesions is invasive, may require general anesthesia and requires more time to recover. Light and laser therapies offer an alternative treatment for AKN. The present study systematically reviews the currently available literature on the treatment of AKN. While all modalities are discussed, light and laser therapy is emphasized due to its relatively unknown role in clinical management of AKN. The most studied modalities in the literature were the 1064-nm neodymium-doped yttrium aluminum garnet laser, 810-nm diode laser, and CO(2) laser, which allow for 82–95% improvement in 1–5 sessions. Moreover, side effects were minimal with transient erythema and mild burning being the most common. Overall, further larger-scale randomized head to head control trials are needed to determine optimal treatments

Spatial and temporal patterns of root distribution in developing stands of four woody crop species grown with drip irrigation and fertilization.

Abstract In forest trees, roots mediate such significant carbon fluxes as primary production and soil C02 efflux. Despite the central role of roots in these critical processes, information on root distribution during stand establishment is limited, yet must be described to accurately predict how various forest types, which are growing with a range of resource limitations, might respond to environmental change. This study reports root length density and biomass development in young stands of eastern cottonwood (Populus deltoidies Bartr.) and American sycamore (Platanus occidentalis L.) that have narrow, high resource site requirements, and compares them with sweetgum (Liquidambar styraczj7ua L.) and loblolly pine (Pinus taeda L.), which have more robust site requirements. Fine roots (5 mm) were sampled to determine spatial distribu-tion in response to fertilizer and irrigation treatments delivered through drip irrigation tubes. Root length density and biomass were predominately controlled by stand development, depth and proximity to drip tubes. After accounting for this spatial and temporal variation, there was a significant increase in RLD with fertilization and irrigation for all genotypes. The response to fertilization was greater than that of irrigation. Both fine and coarse roots responded positively to resources delivered through the drip tube, indicating a wholeroot- system response to resource enrichment and not just a feeder root response. The plastic response to drip tube water and nutrient enrichment demonstmte the capability of root systems to respond to supply heterogeneity by increasing acquisition surface. Fineroot biomass, root density and specific root length were greater for broadleaved species than pine. Roots of all genotypes explored the rooting volume within 2 years, but this occurred faster and to higher root length densities in broadleaved species, indicating they had greater initial opportunity for resource acquisition than pine. Sweetgum's root characteristics and its response to resource availability were similar to the other broadleaved species, despite its hnctional resemblance to pine regarding robust site requirements. It was concluded that genotypes, irrigation arid fertilization significantly influenced tree root system development, which varied spatially in response to resource-supply heterogeneity created by dnp tubes. Knowledge of spatial and temporal patterns of root distribution in these stands will be used to interpret nutrient acquisition and soil respiration measurements

Depistage clinique des infections sexuellement transmissibles chez les personnes vivant avec le VIH suivies au Centre de Traitement Ambulatoire du Centre National Hospitalier Universitaire Hubert Koutoukou Maga de Cotonou

Introduction: Depuis l’avènement de l’infection à VIH/SIDA, les IST ont connu un regain d’intérêt parce qu’elles constituent des cofacteurs de celle-ci. Cette étude avait pour but de faire le point sur les différentes IST observées chez les PVVIH au Bénin, en se basant uniquement sur les signes et symptômes cohérents.Matériel et méthodes: Il s’agissait d’une étude transversale descriptive qui s’était déroulée au Centre de Traitement Ambulatoire (CTA) des PVVIH du Centre National Hospitalier et Universitaire Hubert Koutoukou MAGA (CNHU/HKM) de Cotonou durant une période de quatre mois. Etaient inclues toutes les PV VIH adultes vues pendant la période de collecte des données, et qui avaient donné leur accord de participation à l’étude.Résultats: Six cent-dix patients avaient été examinés ; l’âge moyen des PVVIH était de 38 ans, avec une sex-ratio H/F égale à 0,55. La prévalence des IST était de 20,33%. Les IST retrouvées chez les patients étaient par ordre décroissant les écoulements urétraux, les écoulements vaginaux, les ulcérations génitales et les condylomes.Conclusion: Les PVVIH suivies au CTA du CNHU-HKM de Cotonou avaient un faible niveau de connaissance sur les IST du fait de leur analphabétisme, leur bas niveau d’instruction et du fait d’un défaut de sensibilisation.Mots clés: Dépistage clinique, IST, VIH/SIDA, BéninEnglish Title: Clinical screening of sexually transmitted infections in people living with HIV at the Ambulatory Treatment Center of the National University Hospital Center Hubert Koutoukou Maga of CotonouEnglish AbstractIntroduction: Since the advent of HIV / AIDS, STIs have become more interesting because they are cofactors of HIV/AIDS. The aim of this study was to take stock of the different STIs observed in PLHIV in Benin, based solely on coherent signs and symptoms.Material and methods: This was a descriptive cross-sectional study that took place at the Ambulatory Treatment Center (ATC) of the PLHIV of the National University Hospital Center of Hubert Koutoukou MAGA (NUHC-HKM) in Cotonou during a period of four months. Included were all HIV-positive adults seen during the data collection period and who had agreed to participate in the study.Results: Six hundred and ten patients had been examined; mean age was 38 years and the sex-ratio 0.55. The prevalence of STI was 20.33%. STIs found in patients were in decreasing order of urethral discharge, vaginal discharge, genital ulceration and condyloma.Conclusion: PLHIVs attending the ATC at the NUHC-HKM in Cotonou had a low level of knowledge about STIs due to illiteracy, low educational attainment and lack of awareness.Keywords: Clinical screening, STI, HIV/AIDS, Beni

Psoriasis sur peau noire : Aspects epidemiologiques et cliniques en dermatologie a Cotonou (Benin)

Introduction : L’objectif de notre étude était de décrire le profil épidémiologique et clinique du psoriasis sur peau pigmentée en Dermatologie à Cotonou. Méthodes : Une étude rétrospective et descriptive a été réalisée sur 10 ans dans le service de dermatologie du Centre National Hospitalier et Universitaire Hubert Koutoukou Maga de Cotonou. Nous avons inclus tous les patients chez qui le diagnostic de psoriasis était retenu sur la base d’arguments cliniques. Les données ont été saisies et analysées avec le logiciel EPI-Info 7. Résultats : La prévalence du psoriasis était de 0,8% (84/10792). La sex-ratio était de 1,8. La moyenne d’âge était de 37,9 ans +/- 19,2. La tranche d’âge la plus représentée était celle des 18-40 ans, soit 46,4%. Les topographies fréquemment retrouvées étaient : cuir chevelu (39,3%), grands plis (38,1%), coudes (32,1%), genoux (29,8%), jambes (27,4%), thorax et organes génitaux externes (25%). Les formes morphologiques étaient dominées par le psoriasis en plaques (45,2%). Les formes topographiques étaient en majorité le psoriasis du cuir chevelu (16,7%), le psoriasis inversé (11,9%) et le psoriasis palmo-plantaire (10,7%). Les formes graves à type de psoriasis érythrodermique et de rhumatisme psoriasique ont été retrouvées dans des proportions respectives de 14,3% et 9,5%. Conclusion : Le psoriasis était rare dans le service de dermatologie à Cotonou. Il atteignait en majorité les adolescents et adultes jeunes de sexe masculin. Le psoriasis en plaques, le psoriasis du cuir chevelu et le psoriasis inversé étaient les formes cliniques les plus fréquentes. Mots clés : psoriasis, rhumatisme psoriasique, dermatose inflammatoire, peau pigmentée, Bénin English Abstract: Psoriasis on pigmented skin: Epidemiology and clinical features in dermatology in Cotonou (Benin) Introduction: The aim of our study was to describe the epidemiological and clinical features of psoriasis on pigmented skin in Dermatology in Cotonou. Methods: A retrospective and descriptive study was carried out in the dermatology department of Cotonou National and Teaching Hospital over 10 years. It included all patients for whom the clinical diagnosis of psoriasis was retained. Data were entered and analyzed with EPI-Info 7 software. Results: The prevalence of psoriasis was 0.8% (84/10792). The sex ratio was 1.8. The average age was 37.9 years +/- 19.2. The most represented age group was 18-40 years old, or 46. 4%. The topographies frequently found were: scalp (39.3%), folds (38.1%), elbows (32.1%), knees (29.8%), legs (27.4%), thorax and external genitalia (25%). The morphological forms were dominated by plaque psoriasis (45.2%). The topographic forms were mostly scalp psoriasis (16.7%), flexural psoriasis (11.9%) and palmoplantar psoriasis (10.7%). The severe forms of erythrodermic psoriasis and psoriatic arthritis were found in respective proportions of 14.3% and 9.5%. Conclusion: Psoriasis was rare in the dermatology department in Cotonou. It mainly reached adolescents and young adults of the male sex. Plaque psoriasis, scalp psoriasis and flexural psoriasis were the most common clinical forms. Keywords: psoriasis, psoriatic arthritis, inflammatory dermatosis, pigmented skin, Beni