Effectiveness of highly active antiretroviral therapy in HIV-positive children: evaluation at 12 months in a routine program in Cambodia.

OBJECTIVE: Increasing access to highly active antiretroviral therapy to reach all those in need in developing countries (scale up) is slowly expanding to HIV-positive children, but documented experience remains limited. We aimed to describe the clinical, immunologic, and virologic outcomes of pediatric patients with >12 months of highly active antiretroviral therapy in 2 routine programs in Cambodia. METHODS: Between June 2003 and March 2005, 212 children who were younger than 13 years started highly active antiretroviral therapy. Most patients started a standard first-line regimen of lamivudine, stavudine, and nevirapine, using split adult fixed-dosage combinations. CD4 percentage and body weight were monitored routinely. A cross-sectional virologic analysis was conducted in January 2006; genotype resistance testing was performed for patients with a detectable viral load. RESULTS: Mean age of the subjects was 6 years. Median CD4 percentage at baseline was 6. Survival was 92% at 12 months and 91% at 24 months; 13 patients died, and 4 were lost to follow-up. A total of 81% of all patients had an undetectable viral load. Among the patients with a detectable viral load, most mutations were associated with resistance to lamivudine and non-nucleoside reverse-transcriptase inhibitor drugs. Five patients had developed extensive antiretroviral resistance. Being an orphan was found to be a predictor of virologic failure. CONCLUSIONS: This study provides additional evidence of the effectiveness of integrating HIV/AIDS care with highly active antiretroviral therapy for children in a routine setting, with good virologic suppression and immunologic recovery achieved by using split adult fixed-dosage combinations. Viral load monitoring and HIV genotyping are valuable tools for the clinical follow-up of the patients. Orphans should receive careful follow-up and extra support

Influence of weather and endogenous cycles on spatiotemporal yield variation in oil palm

Oil palm is the major source of vegetable oil in the world and Indonesia is the main palm oil producing country. There is limited knowledge on the factors accounting for spatial and temporal variation in fresh fruit bunches (FFB) yield. Here we investigated relationships between weather and endogenous factors with FFB yield and its components (bunch number and individual bunch weight) using data collected from well-managed plantations in Indonesia. The database included many sites and years (total of 136 block-years observations), portraying a wide range of FFB yield and environmental conditions. We used average annual values to detect spatial variations in yield associated with weather, and monthly values to detect temporal yield variations in yield associated with weather and endogenous cycles. We found that water stress was the key factor accounting for the spatial and/or temporal variation in FFB yield. Our analysis also highlights the importance of vapor pressure deficit (VPD) as a stress factor in oil palm, with this study being the first to demonstrate the negative relationship between yield and VPD and yield and water-use efficiency at the block level. Meteorological anomalies during the bunch failure, anthesis, and sex differentiation periods had the largest impact on yield. Besides climate factors, we confirmed the existence of endogenous yield cycles, with high-yield cycles typically followed by low-yield cycles and vice versa. Our findings extend current knowledge about sources of variation in oil palm yield, providing useful information to describe oil palm production environments and improve oil palm modeling and yield forecasting.Fil: Monzon, Juan Pablo. Universidad de Nebraska - Lincoln; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Jabloun, Mohamed. University of Agriculture Wageningen; Países BajosFil: Cock, James. Centro Internacional de Agricultura Tropical; ColombiaFil: Caliman, Jean Pierre. Smart Research Institute; IndonesiaFil: Couëdel, Antoine. Universidad de Nebraska - Lincoln; Estados UnidosFil: Donough, Christopher R.. Universidad de Nebraska - Lincoln; Estados UnidosFil: Vui, Philip Ho Vun. Wilmar International; IndonesiaFil: Lim, Ya Li. Universidad de Nebraska - Lincoln; Estados UnidosFil: Mathews, Joshua. Research Centre Pt Bumitama Gunajaya Agro; IndonesiaFil: Oberthür, Thomas. Mohammed Vi Polytechnic University; MarruecosFil: Prabowo, Noto E.. Jln. A. Yani No. 2; IndonesiaFil: Rattalino Edreira, Juan Ignacio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentina. Universidad de Nebraska - Lincoln; Estados UnidosFil: Sidhu, Manjit. Tebing Tinggi Deli; IndonesiaFil: Slingerland, Maja A.. University of Agriculture Wageningen; Países BajosFil: Sugianto, Hendra. Universidad de Nebraska - Lincoln; Estados UnidosFil: Grassini, Patricio. Universidad de Nebraska - Lincoln; Estados Unido

Soil physico-chemical properties in a selectively logged forest at Gunung Rara Forest Reserve, Sabah, Malaysia

The tropical rainforest has various lists of crucial functions in forest productivity. However, unsustainable logging method has led to the decline of soil fertility in the forest. This study aimed to investigate the impacts of different logging methods on the soil’s physical and chemical properties at Gunung Rara Forest Reserve, Sabah, Malaysia. The logging treatments were supervised logging with climber cutting (SLCC) and conventional logging (CL), and a virgin forest (VF) was used as the control plot. The size for each plot was one hectare and each was replicated into four plots making the total plots 12. Soil sampling was done at four depths (0–10 cm, 10–20 cm, 20–50 cm, and 50–100 cm) for soil analysis and bulk density. The finding shows that the soil properties in the treatment plots were not significantly different from the untreated plot. The soil organic matter, total nitrogen, and total carbon decreased with soil depths. The soil in all study areas was found acidic, ranging from 4.12 to 4.46. The soil textures were clay, sandy clay loam, and sandy loam. The SLCC plot recorded a higher mean of soil organic matter (5.93–7.40%), total phosphorus (0.08–0.09 meq/100 g), and cation exchange capacity (5.69–7.05 meq/100 g) compared to other plots. This study highlights the importance of analysing the impact of different logging methods on the soil’s physicochemical properties

Influence of weather and endogenous cycles on spatiotemporal yield variation in oil palm

Oil palm is the major source of vegetable oil in the world and Indonesia is the main palm oil producing country. There is limited knowledge on the factors accounting for spatial and temporal variation in fresh fruit bunches (FFB) yield. Here we investigated relationships between weather and endogenous factors with FFB yield and its components (bunch number and individual bunch weight) using data collected from well-managed plantations in Indonesia. The database included many sites and years (total of 136 block-years observations), portraying a wide range of FFB yield and environmental conditions. We used average annual values to detect spatial variations in yield associated with weather, and monthly values to detect temporal yield variations in yield associated with weather and endogenous cycles. We found that water stress was the key factor accounting for the spatial and/or temporal variation in FFB yield. Our analysis also highlights the importance of vapor pressure deficit (VPD) as a stress factor in oil palm, with this study being the first to demonstrate the negative relationship between yield and VPD and yield and water-use efficiency at the block level. Meteorological anomalies during the bunch failure, anthesis, and sex differentiation periods had the largest impact on yield. Besides climate factors, we confirmed the existence of endogenous yield cycles, with high-yield cycles typically followed by low-yield cycles and vice versa. Our findings extend current knowledge about sources of variation in oil palm yield, providing useful information to describe oil palm production environments and improve oil palm modeling and yield forecasting

Variable responses of individual species to tropical forest degradation

The functional stability of ecosystems depends greatly on interspecific differences in responses to environmental perturbation. However, responses to perturbation are not necessarily invariant among populations of the same species, so intraspecific variation in responses might also contribute. Such inter-population response diversity has recently been shown to occur spatially across species ranges, but we lack estimates of the extent to which individual populations across an entire community might have perturbation responses that vary through time. We assess this using 524 taxa that have been repeatedly surveyed for the effects of tropical forest logging at a focal landscape in Sabah, Malaysia. Just 39 % of taxa – all with non-significant responses to forest degradation – had invariant responses. All other taxa (61 %) showed significantly different responses to the same forest degradation gradient across surveys, with 6 % of taxa responding to forest degradation in opposite directions across multiple surveys. Individual surveys had low power (< 80 %) to determine the correct direction of response to forest degradation for one-fifth of all taxa. Recurrent rounds of logging disturbance increased the prevalence of intra-population response diversity, while uncontrollable environmental variation and/or turnover of intraspecific phenotypes generated variable responses in at least 44 % of taxa. Our results show that the responses of individual species to local environmental perturbations are remarkably flexible, likely providing an unrealised boost to the stability of disturbed habitats such as logged tropical forests

Is Malaysia’s banded langur, Presbytis femoralis femoralis, actually Presbytis neglectus neglectus? Taxonomic revision with new insights on the radiation history of the Presbytis species group in Southeast Asia

The disjunct distribution of Presbytis femoralis subspecies across Sumatra (P. f. percura), southern (P. f. femoralis) and northern (P. f. robinsoni) Peninsular Malaysia marks the unique vicariance events in the Sunda Shelf. However, the taxonomic positions and evolutionary history of P. f. femoralis are unresolved after decades of research. To elucidate this evolutionary history, we analyzed 501 base pairs of the mitochondrial HVSI gene from 25 individuals representing Malaysia’s banded langur, with the addition of 29 sequences of Asian Presbytis from Genbank. Our results revealed closer affinity of P. f. femoralis to P. m. mitrata and P. m. sumatrana while maintaining the monophyletic state of P. f. femoralis as compared to P. f. robinsoni. Two central theses were inferred from the results; (1) P. f. femoralis does not belong in the same species classification as P. f. robinsoni, and (2) P. f. femoralis is the basal lineage of the Presbytis in Peninsular Malaysia. Proving the first hypothesis through genetic analysis, we reassigned P. f. femoralis of Malaysia to Presbytis neglectus (Schlegel’s banded langur) (Schlegel in Revue Methodique, Museum d’Histoire Naturelle des Pays-Bas 7:1, 1876) following the International Code of Zoological Nomenclature (article 23.3). The ancestors of P. neglectus are hypothesized to have reached southern Peninsular Malaysia during the Pleistocene and survived in refugium along the western coast. Consequently, they radiated upward, forming P. f. robinsoni and P. siamensis resulting in the highly allopatric distribution in Peninsular Malaysia. This study has successfully resolved the taxonomic position of P. neglectus in Peninsular Malaysia while providing an alternative biogeographic theory for the Asian Presbytis