Tropical Climate Research Papers - Academia.edu (original) (raw)

The objective of this study was to estimate the prevalence of and risk factors for pathological conditions of the reproductive organs in stray dogs under tropical conditions. Three hundred and eighteen dogs were examined post-mortem in the period from 1 July 2002 to 30 June 2003. Before killing, a blood sample (from the cephalic vein) for testosterone assay was taken. Pathological conditions of the reproductive organs were found in 135 of the dogs (42.5%) and in 175 of the testes (64.8%). The most frequent pathologies found were testicular degeneration, cryptorchidism, testicular hypoplasia and testicular tumours (in 15.1%, 6.6%, 6.6% and 5.4% of the dogs and 15.1, 4.6, 6.0 and 3.5 of the testes, respectively). Transmissible venereal tumour (TVT) was seen in 5.4% of the dogs. Testicular degeneration was more common in old dogs and underweight dogs (p < 0.05). Testicular tumours were 14.3 times more common in cryptorchid dogs. Age was another important factor for the development of testicular tumours (p < 0.05). Lower levels of testosterone concentration (p < 0.05) were observed in dogs with advanced testicular degeneration (0.7 +/- 0.8 nM), dogs with hypoplastic testicles (0.8 +/- 0.9 nM) and dogs with one degenerated and one retained testis or with bilateral cryptorchidism (1.2 +/- 0.9 nM) compared to dogs with one or two normal testes (7.0 +/- 5.5 nM). Testicular volume and weight were significantly lower in degenerated, hypoplastic and retained testes compared with the contralateral normal testis. Some spermatogenic activity was found in three of the retained testes, producing oligozoospermic smears with a high percentage of sperm abnormalities. No comparable epidemiological data about male pathological conditions of the reproductive organs in the dog is available. The prevalence found in this study, yet, appears high.

- by and +2
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- Reproduction, Mexico, Biological Sciences, Dogs
- by Forrest Brem
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- Population Dynamics, Biodiversity, Multidisciplinary, Panama

El método FAO Penman (PM), es el más confiable para estimar la evapotranspiración de referencia (ETo) y es recomendado por la FAO como estándar para verificar otros métodos empíricos. En su utilización es necesaria información de cuatro parámetros meteorológicos: temperatura del aire, humedad relativa, velocidad del viento y radiación neta. La poca disponibilidad de estos parámetros limita el uso del método en muchos lugares; por lo que los modelos Thornthwaite (TM) y Hargreaves (HM) son usados con frecuencia, ya que únicamente se basan en medidas de temperatura del aire, medidas comunes en muchas estaciones meteorológicas en todo el mundo, por lo que son una opción para estimar la ETo. Sin embargo, con el objetivo de obtener resultados apropiados de ETo, los modelos HM y TM deben ser calibrados de acuerdo con las condiciones locales. En el presente estudio, los coeficientes originales de TM y HM son modificados para una calibración local en climas semi-áridos y tropicales sub-húmedos del estado de Yucatán, México, usando como estándar la ecuación Penman-de FAO. Se usaron datos meteorológicos de dos estaciones en el estado de Yucatán, México que corresponden a un clima costero semi-árido (Progreso) y a un clima tropical sub-húmedo tierra adentro (Mérida). En la comparación se analizaron los índices de concordancia (D), confianza (C), correlación (R) y regresión (R 2 ), así como indicadores del sesgo medio del error (MBE), raíz cuadrada media del error (RMSE), error relativo (RE) y el cociente entre ambas estimaciones promedio de ETo ( r). Usando HM sin ajuste se obtuvieron buenas estimaciones de ETo en Mérida y Progreso, con valores de C de 0.825 y 0.816, respectivamente. No se recomienda el uso de TM sin ajuste en ninguna de las estaciones meteorológicas estudiadas. Sin embargo, en ambas estaciones, el modelo TM estima mejor la Eto durante los meses lluviosos (de junio a octubre). En ambas estaciones meteorológicas, costera y de tierra adentro, se obtuvieron mejores estimaciones anuales de ETo con el uso de HM sin ajuste (valores de C de 0.906 y 0.917, respectivamente).

and aggression during the breeding season. However, the role of T in year-round territorial birds is still enigmatic, especially in tropical birds. Spotted antbirds (Hylophylax n. naevioides) defend territories in the Panamanian rainforest year-round but have low plasma T levels (0.1-0.2 ng/ml), except during brief periods of social challenges. We manipulated T action in captive male Spotted antbirds to test whether this hormone is involved in the regulation of song and aggression. Timplants increased plasma androgen levels (T and dihydrotestosterone) and enhanced song in nonbreeding males. During a staged male-male encounter, T-implanted males sang more and were more aggressive than controls. In a second experiment, we blocked the two known T actions: its binding to androgen receptors and its conversion into estradiol by the enzyme aromatase. For this, we administered the androgen receptor antagonist flutamide (Flut) in combination with the aromatase inhibitor 1-4-6 androstatrien-3,17-dione (ATD) to birds in breeding condition. ATD ؉ Flut treatment significantly elevated plasma levels of luteinizing hormone, presumably via the lack of T feedback from its receptors. ATD ؉ Flut-treated birds gave fewer spontaneous songs than control-implanted males. During staged male-male encounters, ATD ؉ Flut-treated males did not sing at all and showed reduced aggressive behavior. Our data indicate that T can regulate aggressive behavior in these tropical birds. Although plasma T levels can be low year-round, Spotted antbirds may use T either by secreting it briefly during social challenges, by having a high sensitivity to T action, or by enzymatically converting circulating T precursors directly at the site of action. We hypothesize that plasma T levels are kept low in these year-round territorial birds to avoid potentially detrimental effects of tonically elevated T. Future treatment of nonbreeding birds with ATD ؉ Flut will reveal whether T is indeed involved year-round in regulating aggressive behavior.

- by Kiran Soma
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- Physiology, Zoology, Animal Behavior, Reproduction

Re-establishing connectivity between protected areas isolated by habitat clearing is a key conservation goal in the humid tropics. In northeastern Costa Rica, payments for environmental services (PES) and a government ban on deforestation have subsidized forest protection and reforestation in the San Juan-La Selva Biological Corridor (SJLSBC), resulting in a decline in mature forest loss and the expansion of tree plantations. We use field studies and graph models to assess how conservation efforts have altered functional connectivity over the last 25 years for four species of insectivorous understory birds. Field playback studies assessed how reforestation habitat quality affected the willingness of Myrmeciza exsul, Henicorhina leucosticta, Thamnophilus atrinucha, and Glyphorynchus spirurus to travel outside forest habitat for territorial defense. Observed travel distances were greatest in nonnative and native tree plantations with high understory stem density, regardless of overstory composition. In contrast, tree plantations with low stem density had travel responses comparable to open pasture for three of the four bird species. We modeled landscape connectivity for each species using graph models based on varying possible travel distances in tree plantations, gallery forests, and pastures. From 1986 to 2011, connectivity for all species declined in the SJLSBC landscape (5825 km 2) by 14% to 21% despite only a 4.9% net loss in forest area and the rapid expansion of tree plantations over 2% of the landscape. Plantation placement in the landscape limited their potential facilitation of connectivity because they were located either far from forest cover or within already contiguous forest areas. We mapped current connectivity bottlenecks and identified priority areas for future reforestation. We estimate that reforestation of priority areas could improve connectivity by 2% with only a 1% gain in forest cover, an impressive gain given the small area reforested. Results indicate key locations where spatial targeting of PES within the SJLSBC study region would protect existing forest connectivity and enhance the connectivity benefits of reforestation.

- by Steven Sesnie
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- Costa Rica, Biological Sciences, Environmental Sciences, Birds

Epidermal changes caused by a chytridiomycete fungus (Chytridiomycota; Chytridiales) were found in sick and dead adult anurans collected from montane rain forests in Queensland (Australia) and Panama during mass mortality events associated with significant population declines. We also have found this new disease associated with morbidity and mortality in wild and captive anurans from additional locations in Australia and Central America. This is the first report of parasitism of a vertebrate by a member of the phylum Chytridiomycota. Experimental data support the conclusion that cutaneous chytridiomycosis is a fatal disease of anurans, and we hypothesize that it is the proximate cause of these recent amphibian declines.

- by dip putradi
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- Tropical Ecology, Australia, Scanning Electron Microscopy, Population Dynamics

Stable isotope analyses are widely used to determine trophic levels in ecological studies. We have investigated the effects of carbonate removal via acidification on the stable carbon and nitrogen isotopic composition of 33 species of tropical benthic macrofauna, and we report guidelines for standardizing this procedure for higher taxa in tropical coral reef ecosystems. Many tropical benthic invertebrates are small in size, and therefore body tissue isolation (separating organic carbon from inorganic structures) is difficult and time-consuming. Literature reviews of invertebrate studies show a lack of consistent procedures and guidelines for preparation techniques, especially for carbonate removal via acidification of whole individuals. We find that acidification decreases the δ13C values of samples containing carbonate, with shifts ranging from 0.21 to 3.20‰, which can be related to CaCO3 content (assessed by a carbonate proxy), justifying acid pre-treatment. Carbonate-containing taxa benefiting from acidification included Amphinomida, Terebellida (Annelida), Anomura, Brachyura, Caridea, Amphipoda, Tanaidacea (Arthropoda) and Edwardsiida (Cnidaria). The δ13C shifts of samples containing no carbonate varied up to 0.02 ± 0.20‰. As this induced δ13C shift was lower than the range of an average trophic level shift (0.5 to 1‰), we conclude that acid pre-treatment is unnecessary. Carbonate-free taxa consisted of Eunicida, Phyllodocida (Annelida) and Mollusca. We note minimal impact of acidification on δ15N values except for Brachyura, which showed a shift of 0.83 ± 0.46‰, which is still lower than a single trophic level shift (2.9–3.8‰). We conclude that for trophic level studies, both the δ13C and the δ15N of carbonate-rich macrofauna can be determined from the same acidified sample. Copyright © 2008 John Wiley & Sons, Ltd.

- by Karyne Rogers
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- Earth Sciences, Mass Spectrometry, Biological Sciences, Anthozoa
- by Sharon Doty
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- Water, Groundwater Contamination, Multidisciplinary, Tropical trees
- by Ángel Benítez
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- Biology, Ecuador, Biodiversity, Medicine

Hair sheep ewes (St. Croix White and Barbados Blackbelly) were used to evaluate 3 methods of estrus synchronization for use with transcervical artificial insemination (TAI). To synchronize estrus, ewes (n = 18) were treated with PGF2¢ (15 mg, im) 10 d apart, with controlled internal drug release (CIDR) devices containing 300 mg progesterone for 12 d (n = 18), or with intravaginal sponges containing 500 mg progesterone for 12 d (n = 18). On the day of the second PGF2a injection or at CIDR or sponge removal, sterile rams were placed with the ewes. jugular blood samples were collected from the ewes at 6-h intervals until the time of ovulation, and daily for 16 d after estrus (Day 0). Plasma was harvested and stored at-20°C until LH, and progesterone concentrations were determined by RIA. There was no difference (P > 0.10) in time to estrus among the CIDR-, PGF2c¢-or sponge-treated ewes. All of the ewes in the CIDR group and 94.4% of the sponge treated ewes exhibited estrus by 36 h after ram introduction, while only 72.2% of PGF2a-treated ewes showed signs of estrus by this time (P < 0.06). The time from ram introduction to ovulation was not different (P > 0.10) among the CIDR-, PGF2c¢-or sponge-treated ewes. The time to the preovulatory LH surge was similar (P > 0.10) among CIDR, PGF2c¢ and sponge treated ewes. Progesterone levels through Day 16 after the synchronized estrus were not different (P > 0.10) among treatment groups. Hair sheep ewes (n = 23) were synchronized using PGF2c¢ and bred by TAI using frozenthawed semen 48 h after the second injection. The conception rate to TAI was 2/23 (8.7%) and produced 3 ram lambs. In a subsequent trial, 17 ewes were synchronized with CIDR devices and bred by TAI using frozen-thawed semen 48 h after CIDR removal, resulting in a conception rate of 52.9 % (9/17). It is possible to synchronize estrus in hair sheep using either CIDRs, sponges or PGF2c¢. Even though there were no significant differences in the timing of ovulation Or the LH surge among the treatment groups, a higher conception rate was achieved in ewes synchronized with CIDR devices during the second trial. This may reflect an increase in the skill level of the TAI technidan.

- by Ramiro Valentim
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- Theriogenology, Biological Sciences, Progesterone, Sheep

Social wasps from temperate zones have clear annual colony cycles, and the young queens hibernate during winter. In the subtropics, the only previously reported evidence for the existence of “hibernation” is the facultative winter aggregations of females during harsh climate conditions. As in temperate-zone species analyzed so far, we show in this study that in the paper wasp, Polistes versicolor, a subtropical species, body size increases as an unfavorable season approaches. Our morphological studies indicate that larger females come from winter aggregations—that is, they are new queens. Multivariate analyses indicate that size is the only variable analyzed that shows a relationship to the differences. Given the absence of a harsh climate, we suggest that the occurrence of winter aggregations in tropical P. versicolor functions to allow some females to wait for better environmental conditions to start a new nest, rather than all being obliged to start a new nest as soon as they emerge.

- by Marcelo Penna
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- Brazil, Multidisciplinary, Seasonality, Wasps

We hypothesize that floating debris leaving polluted coastal bays accumulate on nearby pristine beaches. We examined composition, quantities and distribution of marine debris along ∼150 km of relatively undeveloped, tropical beaches in Costa do Dendê (Bahia, Brazil). The study site is located south of Salvador City, the largest urban settlement from NE Brazil. Strong spatial variations were observed. Plastics accounted for 76% of the sampled items, followed by styrofoam (14%). Small plastic fragments resultant from the breakdown of larger items are ubiquitous all over the area. Because the dominant littoral drift in Bahia is southward, average beach debris densities (9.1 items/m) along Costa do Dendê were threefold higher than densities previously observed north of Salvador City. River-dominated and stable beaches had higher debris quantities than unstable, erosional beaches. Areas immediately south of the major regional embayments (Camamu and Todos os Santos) were the preferential accumulation sites, indicating that rivers draining populous areas are the major source of debris to the study site. Our results provide baseline information for future assessments. Management actions should focus on input prevention at the hydrographic basin level rather than on cleaning services on beaches.

- by isaac santos
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- Brazil, Environmental Monitoring, Multidisciplinary, Solid waste

Since the 1990s, rising commodity prices and declining per capita cultivated area have led to decreases in food production, eroding food security in many communities (2). Many regions that lack food security rely on local agricultural... more

- by Chris Funk
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- Poverty, Science, Forecasting, Developing Countries

Application of the thermal sum concept was developed to determine the optimal harvesting stage of new banana hybrids to be grown for export. It was tested on two triploid hybrid bananas, FlhorBan 916 (F916) and FlhorBan 918 (F918), created by CIRAD's banana breeding programme, using two different approaches. The first approach was used with F916 and involved calculating the base temperature of bunches sampled at two sites at the ripening stage, and then determining the thermal sum at which the stage of maturity would be identical to that of the control Cavendish export banana. The second approach was used to assess the harvest stage of F918 and involved calculating the two thermal parameters directly, but using more plants and a longer period. Using the linear regression model, the estimated thermal parameters were a thermal sum of 680 degree-days (dd) at a base temperature of 17.0 • C for cv. F916, and 970 dd at 13.9 • C for cv. F918. This easy-to-use method provides quick and reliable calculations of the two thermal parameters required at a specific harvesting stage for a given banana variety in tropical climate conditions. Determining these two values is an essential step for gaining insight into the agronomic features of a new variety and its potential for export.

- by Olivier Hubert
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- Horticulture, Hybrid, Exportation, Temperature

The objective of this study was to describe the sexual characteristics of domestic queens kept under natural equatorial photoperiod conditions without mating. Estrous signs were detected in 25 pubertal queens by manual stimulation and by exposure to a tomcat twice daily for 6 months (January to June). The signs observed were tail deflection, spinal flexion, rubbing or rolling, vaginal discharge, vocalization, treading of the hind legs, body or tail tremor and rigidity, blow or scratches, and discomfort on manipulation. The queen was considered in estrous when neck grip, tail deflection and attempted penile intromission by the male were allowed after mounting. From 187 cycles, there were (mean AE S.E.M.) 7.5 AE 0.7 cycles detected per queen; the duration of the cycle, estrus and non-acceptance were 18.1 AE 0.9, 7.9 AE 0.5, and 10.3 AE 0.9 d, respectively. Queens always maintained some signs of sexual behaviour; they remained ambivalent for no more than 24 h at a time. It was noted that 85.3% of the observations of body or tail tremor and rigidity were made during estrus; therefore, these signs were considered characteristic of sexual receptivity. There was no evidence of prolonged anestrus or of a circannual pattern to estrus cyclicity. #

- by Daniel Uchoa
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- Sexual Behaviour, Brazil, Cats, Theriogenology

Leaf-cutting ants (Atta spp.) are known for their extensive defoliation in neo-tropical forests and savannahs. Debate about the costs and benefits of their activities has been largely dominated by their detrimental effects on agriculture and agroforestry. However, the large accumulation of nutrients and changes in soil properties near their nests might benefit plants growing near them. Here, we test whether trees use nutrients that accumulate in debris piles near, or refuse chambers within, leaf-cutting ant nests. At two tropical sites (a moist tropical forest site in Panama and a savannah site in Brazil), we fed leaves labelled with the stable isotope 15N to two species of leaf-cutting ants (Atta colombica and Atta laevigata) and traced the stable isotope label in plants surrounding the two nests. Thus, we show that plants in both sites access resources associated with Atta nests. In addition, leaf tissue of trees near the nests labelled with 15N had significantly higher calcium co...

- by Marcelo Moreira
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- Soil, Brazil, Panama, Biological Sciences

The evolution of industrial-era warming across the continents and oceans provides a context for future climate change and is important for determining climate sensitivity and the processes that control regional warming. Here we use post-ad 1500 palaeoclimate records to show that sustained industrial-era warming of the tropical oceans first developed during the mid-nineteenth century and was nearly synchronous with Northern Hemisphere continental warming. The early onset of sustained, significant warming in palaeoclimate records and model simulations suggests that greenhouse forcing of industrial-era warming commenced as early as the mid-nineteenth century and included an enhanced equatorial ocean response mechanism. The development of Southern Hemisphere warming is delayed in reconstructions, but this apparent delay is not reproduced in climate simulations. Our findings imply that instrumental records are too short to comprehensively assess anthropogenic climate change and that, in ...

- by Belen Martrat
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- Geography, Environmental Science, Medicine, Multidisciplinary

Summary: Purpose: Cerebral malaria (CM) is suspected to be a potential cause of epilepsy in tropical areas, but little information is available. The purpose of this study was to evaluate the role of CM in epilepsy among children in Mali. Methods: An exposed–nonexposed study was performed to identify children who had epilepsy after malaria in the 0- to 15-year age group. The exposure factor was CM defined according to World Health Organization (WHO) criteria, and the nonexposure factor was symptomatic malaria without the characteristics of CM (NCM). All the children underwent a screening questionnaire and were examined by a medical physician. After the screening phase, a specialist in neuropediatrics examined the children suspected to have epilepsy. EEG and computed tomography (CT) scans were performed in some of these patients. Results: In total, 101 subjects who had had CM and 222 who had had NCM were included. Fifty-four children (CM, 34; NCM, 20) were suspected to have epilepsy, and six were confirmed (CM, five; NCM, one). The incidence rate was 17.0 per 1000 person-years in the CM group and 1.8 per 1000 person-year in the NCM group; thus the relative risk (RR) was 9.4 [95% confidence interval (CI), 1.3–80.3; p = 0.02]. After adjustment on age and duration of follow-up, the RR was 14.3 (95% CI, 1.6–132.0; p = 0.01). Conclusions: The risk of sequelar epilepsy is significantly higher in the CM group compared with the NCM group. A reevaluation of this cohort should be carried out later to search for temporal epilepsy that appeared after age 10 years.

- by Alassane Dicko
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- West Africa, Epilepsy, Mali, Child

Solar cooling applied to buildings is without a doubt an interesting alternative for reducing energy consumption in traditional mechanical steam compression air conditioning systems. The study of these systems should have a closely purely fundamental approach including the development of numerical models in order to predict the overall installation performance. The final objective is to estimate cooling capacity, power consumption, and overall installation performance with relation to outside factors (solar irradiation, outside temperature.). The first stage in this work consists of estimating the primary energy produced by the solar collector field. The estimation of this primary energy is crucial to ensure the evaluation of the cooling capacity and therefore the cooling distribution and thermal comfort in the building. Indeed, the absorption chiller performance is directly related to its heat source. This study presents dynamic models for double glazing solar collectors and compares the results of the simulation with experimental results taken from our test bench (two collectors). In the second part, we present an extensive collector field model (36 collectors) from our solar cooling installation at The University Institute of Technology in St Pierre, Reunion Island as well as our stratified tank storage model. A comparison of the simulation results with real scale solar experimental data taken from our installation enables validation of the double glazing solar collector and stratified tank dynamic models.

- by Jean Philippe Praene
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- Mechanical Engineering, Modeling, Performance, Energy Consumption

We evaluated three spatially explicit land use and cover change (LUCC) models to project deforestation from 2005-2020 in the carbon-rich peat swamp forests (PSF) of Central Kalimantan, Indonesia. Such models are increasingly used to evaluate the impact of deforestation on carbon fluxes between the biosphere and the atmosphere. We considered both business-as-usual (BAU) and a forest protection scenario to evaluate each model's accuracy, sensitivity, and total projected deforestation and landscapelevel fragmentation patterns. The three models, Dinamica EGO (DE), GEOMOD and the Land Change Modeler (LCM), projected similar total deforestation amounts by 2020 with a mean of 1.01 million ha (Mha) and standard deviation of 0.17 Mha. The inclusion of a 0.54 Mha strict protected area in the LCM simulations reduced projected loss to 0.77 Mha over 15 years. Calibrated parameterizations of the models using nearly identical input drivers produced very different landscape properties, as measured by the number of forest patches, mean patch area, contagion, and Euclidean nearest neighbor determined using Fragstats software. The average BAU outputs of the models suggests that Central Kalimantan may lose slightly less than half (45.1%) of its 2005 PSF by 2020 if measures are not taken to reduce deforestation there. The relatively small reduction of 0.24 Mha in deforestation found in the 0.54 Mha protection scenario suggests that these models can identify potential leakage effects in which deforestation is forced to occur elsewhere in response to a policy intervention.

- by Martin Hardiono
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- Soil, Wetlands, Carbon, Environmental Management

International regulation of organotin compounds for use in antifouling paints has led to the development and increased use of replacement compounds, notably the s-triazine herbicide Irgarol 1051. Little is known about the distribution of Irgarol 1051 in tropical waters. Nor has the potential impact of this triazine upon photosynthesis of endosymbiotic microalgae (zooxanthellae) in corals been assessed. In this study Irgarol 1051 was detected in marinas, harbours and coastal waters of the Florida Keys, Bermuda and St. Croix, with concentrations ranging between 3 and 294 ng l À1 . 14 C incubation experiments with isolated zooxanthellae from the common inshore coral Madracis mirabilis showed no incorporation of H 14 CO À 3 from the sea water medium after 4-8 h exposure to Irgarol 1051 concentrations as low as 63 ng l À1 . Reduction in net photosynthesis of intact corals was found at concentrations of 100 ng l À1 with little or no photosynthesis at concentrations exceeding 1000 ng l À1 after 2-8 h exposure at all irradiances. The data suggest Irgarol 1051 to be both prevalent in tropical marine ecosystems and a potent inhibitor of coral photosynthesis at environmentally relevant concentrations. Ó

- by Anthony Knap
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- Photosynthesis, Multidisciplinary, Anthozoa, Ecosystem

Background: After many years of general neglect, interest has grown and efforts came under way for the mapping, control, surveillance, and eventual elimination of neglected tropical diseases (NTDs). Disease risk estimates are a key feature to target control interventions, and serve as a benchmark for monitoring and evaluation. What is currently missing is a georeferenced global database for NTDs providing open-access to the available survey data that is constantly updated and can be utilized by researchers and disease control managers to support other relevant stakeholders. We describe the steps taken toward the development of such a database that can be employed for spatial disease risk modeling and control of NTDs.

- by Uwem F Ekpo
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- Open Access, Monitoring And Evaluation, Africa, Global Health
- by Mateus Batistella and +3
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- Landscape Ecology, Forestry, Research Design, Conservation Biology
- by Retneswari Masilamani
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- Malaysia, Vibration, Construction Industry, Young Adult
- by grace iyeghe-erakpotobor
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- Physiology, Reproduction, Biology, Lactation

The genomic era facilitates the understanding of how transcriptional networks are interconnected to program seed development and filling. However, to date, little information is available regarding dicot seeds with a transient perisperm and a persistent, copious endosperm. Coffea arabica is the subject of increasing genomic research and is a model for nonorthodox albuminous dicot seeds of tropical origin.The aim of this study was to reconstruct the metabolic pathways involved in the biosynthesis of the main coffee seed storage compounds, namely cell wall polysaccharides, triacylglycerols, sucrose, and chlorogenic acids. For this purpose, we integrated transcriptomic and metabolite analyses, combining real-time RT-PCR performed on 137 selected genes (of which 79 were uncharacterized in Coffea) and metabolite profiling.Our map-drawing approach derived from model plants enabled us to propose a rationale for the peculiar traits of the coffee endosperm, such as its unusual fatty acid composition, remarkable accumulation of chlorogenic acid and cell wall polysaccharides.Comparison with the developmental features of exalbuminous seeds described in the literature revealed that the two seed types share important regulatory mechanisms for reserve biosynthesis, independent of the origin and ploidy level of the storage tissue.

- by Jordi Salmona
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- Metabolism, Starch, Gene expression, Biological Sciences

Biological impacts of climate warming are predicted to increase with latitude, paralleling increases in warming. However, the magnitude of impacts depends not only on the degree of warming but also on the number of species at risk, their physiological sensitivity to warming and their options for behavioural and physiological compensation. Lizards are useful for evaluating risks of warming because their thermal biology is well studied. We conducted macrophysiological analyses of diurnal lizards from diverse latitudes plus focal species analyses of Puerto Rican Anolis and Sphaerodactyus. Although tropical lowland lizards live in environments that are warm all year, macrophysiological analyses indicate that some tropical lineages (thermoconformers that live in forests) are active at low body temperature and are intolerant of warm temperatures. Focal species analyses show that some tropical forest lizards were already experiencing stressful body temperatures in summer when studied several decades ago. Simulations suggest that warming will not only further depress their physiological performance in summer, but will also enable warm-adapted, open-habitat competitors and predators to invade forests. Forest lizards are key components of tropical ecosystems, but appear vulnerable to the cascading physiological and ecological effects of climate warming, even though rates of tropical warming may be relatively low.

- by Ray Hue
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- Geography, Puerto Rico, Biological Sciences, Phylogeny

Seed desiccation sensitivity limits the ex situ conservation of up to 47 % of plant species, dependent on habitat. Whilst desirable, empirically determining desiccation tolerance levels in seeds of all species is unrealistic. A probabilistic model for the rapid identification of woody species at high risk of displaying seed desiccation sensitivity is presented. The model was developed using binary logistic regression on seed trait data [seed mass, moisture content, seed coat ratio (SCR) and rainfall in the month of seed dispersal] for 104 species from 37 families from a semi-deciduous tropical forest in Panamá. For the Panamanian species, only seed mass and SCR were significantly related to the response to desiccation, with the desiccation-sensitive seeds being large and having a relatively low SCR (i.e. thin 'seed' coats). Application of this model to a further 38 species, of known seed storage behaviour, from two additional continents and differing vegetation types (drylan...

- by Hugh Pritchard
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- Decision Making, Water, Africa, Plant Biology

Screening of aerobic culturable hydrocarbon (HC)-degrading microorganisms isolated from petroleum-polluted soils and cyanobacterial mats from Indonesia resulted in the collection of 33 distinct species. Eight bacteria, 21 fungi and 4 yeasts were identified to the specific level by molecular and phenotypic techniques. Bacterial strains belonged to the genera Gordonia, Brevibacterium, Aeromicrobium, Dietzia, Burkholderia and Mycobacterium. Four species are new and not yet described. Fungi belonged to Aspergillus, Penicillium, Fusarium, Amorphoteca, Neosartorya, Paecilomyces, Talaromyces and Graphium. Yeasts were Candida, Yarrowia and Pichia. All strains were cultivated axenically in synthetic liquid media with crude oil as sole carbon and energy source. After incubation, the detailed chemical composition of the residual oil was studied by gravimetric and gas-chromatographic techniques. Thirteen parameters for assessing the biodegradation potential were defined and computed for each strain. Maximum degradation was observed on the saturated HCs (n-and isoalkanes, isoprenoids), whereas aromatic HC degradation was lower and was related to the structural composition of the molecules. A principal components analysis (PCA) permitted grouping and classifying the strains as a function of their degradative capacities. It was shown that the most active strains produced polar metabolites which accumulated in the resins and asphaltene fractions. These fractions are highly resistant to microbial metabolism. No taxonomic trend could be defined between microbial phyla in terms of HC biodegradation activity.

- by Patrick Grimont
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- Microbiology, Principal Component Analysis, Medical Microbiology, Fungi

In addition to repeated reexperiencing of the event, the delayed effects of severe psychological trauma, i.e., post traumatic stress disorder (PTSD), present a paradoxical mix of symptoms. There is enhancement of the self-preservative catecholamine states; anger and fear with a contrasting sense of meaninglessness and a blunting of the emotional responses of the attachment behavior so critical for species preservation. Hormonally, there is a striking separation of the catecholamine response, which stays elevated and that of the hypothalamo-pituitary-adrenal (HPA) axis, which may remain at normal levels. Pathophysiologically, the reexperiencing of the trauma and the arousal may be associated with dysfunction of the locus coeruleus, amygdala and hippocampal systems. This article explores the consequences of an additional dysfunction: a dissociation of the hemispheres that appears to be responsible for the alexithymic avoidance and failure of the cortisol response that so often follow severe psychological trauma. There is neurophysiological evidence that the left and right hemispheres subserve different emotional sets that correspond to “control” and “appraisal,” i.e., very approximately to the self and species preservative behavioral complexes, respectively. Several studies point to physiological dissociation of hemispheric functions during alexithymia. This raises the question: What has been lost if in this condition the right side no longer fully contributes to integrated cerebral function? Right hemispheric damaged children lose critical social skills and in adults the related sense of familiarity critical for bonding is lost. Such losses of social sensibilities may account for the lack of empathy and difficulties with bonding found in sociopathy and borderline personality: conditions now believed to result from repeated psychological trauma during development. On the other hand, systems that promote right hemispheric contributions provide solacing access to a “Higher Power.” They also appear to protect against socially disordered behavior, substance abuse, the failure of the HPA axis and some aspects of the pathophysiology of chronic disease.

- by James Henry
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- Psychology, Cognitive Science, Pediatric Psychology, Attention

A field experiment was conducted in the farm of Mr Jayanthilal Sachdev, a progressive farmer on a red clay loam soil in the semi-arid tropical climate of South India, to study the influence of planting cornmint (Mentha ar6ensis L. f. piperascens Malinvaud ex Holmes, family: Lamiaceae) in different months on its biomass and essential oil yields. In this climate, cornmint was harvested six-seven times in a period of 17 -18 months. August (rainy), November (autumn), and December (winter) planted crop produced significantly superior total biomass and essential oil yields compared to September and January planted cornmint. The results indicated the feasibility of intercropping cornmint with tomato (6.3 t/ha) during the first harvest period. The quality of the essential oil with 73.0% menthol, 9.6% menthone, 4.0% isomenthone, and 4.0% menthyl acetate was found to be good and readily accepted in the market. This investigation in a farmer's field with 42.5-63.5 t/ha total biomass yield and 196.3 -271.5 kg/ha total essential oil yield, clearly demonstrated the economic feasibility of cultivating cornmint in semi-arid tropical climate. It has also shown the possibility of planting the crop during different seasons and growing it as a biennial.

- by Maria Arraiza
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- South India, Essential Oil, Seasonality, Field Experiment

This study suggests that indoor air-related respiratory symptoms are a matter of concern in places with hot and humid climate. The regression models were adjusted by confounders that could be used in further reanalysis of indoor air... more

- by Jorge Kalil
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- Engineering, Earth Sciences, Brazil, Air Conditioning

The current scale of deforestation in tropical regions and the large areas of degraded lands now present underscore the urgent need for interventions to restore biodiversity, ecological functioning, and the supply of goods and ecological services previously used by poor rural communities. Traditional timber plantations have supplied some goods but have made only minor contributions to fulfilling most of these other objectives. New approaches to reforestation are now emerging, with potential for both overcoming forest degradation and addressing rural poverty.

- by Laysa Beretta
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- Geography, Forestry, Science, Agriculture
- by Angel Solis
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- Bioinformatics, Biomass, Life Sciences, Biodiversity
- by Rajesh Patel
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- Applied Ergonomics, Medical Physiology, Tropical Climate

The present study has demonstrated the expression of HSP60, HSP70, HSP90, and UBQ in peripheral blood mononuclear cells (PBMCs) during different seasons in three different age groups (Groups I, II, and III with age of 0-2, 2-5, and >5 years, respectively) of goats of tropical and temperate regions. Real-time polymerase chain reaction was applied to investigate mRNA expression of examined factors. Specificity of the desired products was documented using analysis of the melting temperature and highresolution gel electrophoresis to verify that the transcripts are of the exact molecular size predicted. The mRNA expression of HSP60, HSP90, and UBQ was significantly higher (P<0.05) in all age groups during peak summer season as compared with peak winter season in both tropical and temperate region goats. HSP70 mRNA expression was significantly higher (P< 0.05) during summer season as compared with winter season in tropical region goats. However, in the temperate region, in goats from all the three age groups studied, a non-significant difference of HSP70 expression between summer and winter seasons was noticed.

- by BIKASH DAS
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- Ubiquitin, Goats, Age Factors, Heat Shock Proteins

and the umbrella motion of CD 3 , resulting in the vibrational anticorrelation of the two receding products. The result presented in Table 1 suggests that the intramolecular energy transfer induced by the chattering motion of D atoms in the transition-state region occurs as a way of conserving the combined energy of the two vibrators. This notable aspect can be regarded as an extension of the dynamics trait of conservation of vibration action found previously for a typical heavy-light-heavy, three-atom reaction (28).

- by Tock Chua and +1
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- Science, Symbiosis, Peru, Multidisciplinary

The objective of this study is to determine the influence of radiant barriers on conductive and radiative heat transfers when they are integrated to a building envelope and to compare their efficiency to traditional insulation material (mineral wools, polystyrene). It is also about determining which insulation material and process can lead to a better heat flux reduction through a building roof. For this study four identical small-scale test cells were used. Their respective roof was equipped with the insulation material to be tested: One with polystyrene, the second with a radiant barrier the third one with fibber glass and the last one with no insulation material was considered as the reference cell. Different test were performed with a view to evaluate the influence of parameters such as roof absorptivity and roof air layer ventilation on the heat flux reduction through the roof. With the measured temperature, the conductive and radiative heat fluxes were calculated. With a white corrugated iron roof top the heat flux reduction provided by the radiant barrier is 37%. With a black one this material allows a reduction of 33%. It is shown that whatever the roof absorptivity value, the radiative heat flux is predominant over the conductive one. With no ventilation, the radiant barrier is comparable to polystyrene and fiber glass; when the airspace is ventilated the radiant barrier provides a better insulation.

- by Ted SOUBDHAN
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- Engineering, Heat Transfer, Solar Energy, Iron

The English publication was issued by the International Council on Archives, The National Archives of the Republic of Indonesia and the National Archives of the Netherlands on the occasion of the international conference The Preservation of Archives in Tropical Climates, which was held in Jakarta 5-8 November 2001. It contains an extensive overview of currently available resources on issues in relation to preservation and conservation in tropical climates, focusing on books and writing materials, building and storage facilities, disaster preparedness and integrated pest management. The second part of the book consists over 1400 literature references.

- by Rene Teijgeler
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- Library Science, Conservation, Sustainable Building Design, Archives

Primary tropical forests are renowned for their high biodiversity and carbon storage, and considerable research has documented both species and carbon losses with deforestation and agricultural land uses. Economic drivers are now leading to the abandonment of agricultural lands, and the area in secondary forests is increasing. We know little about how long it takes for these ecosystems to achieve the structural and compositional characteristics of primary forests. In this study, we examine changes in plant species composition and aboveground biomass during eight decades of tropical secondary succession in Puerto Rico, and compare these patterns with primary forests. Using a well-replicated chronosequence approach, we sampled primary forests and secondary forests established 10, 20, 30, 60, and 80 years ago on abandoned pastures. Tree species composition in all secondary forests was different from that of primary forests and could be divided into early (10-, 20-, and 30-year) vs. late (60-and 80-year) successional phases. The highest rates of aboveground biomass accumulation occurred in the first 20 years, with rates of C sequestration peaking at 6.7 6 0.5 Mg CÁha À1 Áyr À1 . Reforestation of pastures resulted in an accumulation of 125 Mg C/ha in aboveground standing live biomass over 80 years. The 80 year-old secondary forests had greater biomass than the primary forests, due to the replacement of woody species by palms in the primary forests. Our results show that these new ecosystems have different species composition, but similar species richness, and significant potential for carbon sequestration, compared to remnant primary forests.

- by Rebecca Ostertag
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- Carbon, Biomass, Carbon Sequestration, Puerto Rico

Assessing Creepy Crawlies Arthropods are the most diverse group of terrestrial animal species, yet estimates of the total number of arthropod species have varied widely, especially for tropical forests. Basset et al. (p. 1481 , see the cover) now provide more reliable estimates of total arthropod species richness in a tropical rainforest in Panama. Intensive sampling of a half hectare of forest yielded just over 6000 arthropod species. Scaling up this result to the whole forest suggests that the total species diversity lies between 17,000 and 40,000 species.

- by marc pollet
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- Botany, Landscape Ecology, Conservation Biology, Science

Renealmia L.f. (Zingiberaceae) is one of the few tropical plant genera with numerous species in both Africa and South America but not in Asia. Based on phylogenetic analysis of nuclear ribosomal internal transcribed spacer (ITS) and chloroplast trnL-F DNA, Renealmia is shown to be monophyletic with high branch support. Low sequence divergence found in the two genome regions (ITS: 0-2.4%; trnL-F: 0-1.9%) suggests recent diversification within the genus. Molecular divergence age estimates give further support to the recent origin of the genus and show that Renealmia has attained its amphi-Atlantic distribution by an oceanic long-distance dispersal event from Africa to South America during the Miocene or Pliocene (15.8-2.7 My ago). Some support is found for the hypothesis that speciation in neotropical Renealmia was influenced by the Andean orogeny. Speciation has been approximately simultaneous on both sides of the Atlantic, but increased taxon sampling is required to compare the speciation rates between the New World and Old World tropics. (T.E. Särkinen). www.elsevier.com/locate/ympev Molecular Phylogenetics and Evolution 44 (2007) 968-980 R. concinna (2) Panama R. helenae Panama R. concinna (1) Costa Rica R. thyrsoidea (2) Peru R. lucida Panama R. cernua (1) Costa Rica R. pyramidalis Guadeloupe R. alpinia (7) Ecuador R. breviscapa (2) Ecuador R. breviscapa (1) Brazil R. cernua (2) Panama R. pluriplicata Costa Rica R. foliifera Panama R. congesta Costa Rica R. aromatica (3) Venezuela R. aromatica (1) DR R. monosperma Surinam R. alpinia (1) Brazil R. aromatica (2) Peru R. alpinia (7) Ecuador R. dermatopetala Brazil R. alpinia (6) Costa Rica R. alpinia (4) Bolivia R. alpinia (3) Brazil R. alpinia (2) Surinam R. alpinia (5) Costa

- by Michelle L Hart
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- Evolutionary Biology, Genetics, Zoology, Speciation
- by Mercedes Bustamante
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- Brazil, Biological Sciences, Light, Trees

This study focuses on using remote sensing for comparative assessment of surface urban heat island (UHI) in 18 mega cities in both temperate and tropical climate regions. Least-clouded day-and night-scenes of TERRA/MODIS acquired between 2001 and 2003 were selected to generate land-surface temperature (LST) maps. Spatial patterns of UHIs for each city were examined over its diurnal cycle and seasonal variations. A Gaussian approximation was applied in order to quantify spatial extents and magnitude of individual UHIs for inter-city comparison. To reveal relationship of UHIs with surface properties, UHI patterns were analyzed in association with urban vegetation covers and surface energy fluxes derived from high-resolution Landsat ETM+ data. This study provides a generalized picture on the UHI phenomena in the Asian region and the findings can be used to guide further study integrating satellite high-resolution thermal data with land-surface modeling and meso-scale climatic modeling in order to understand impacts of urbanization on local climate in Asia. #

- by Hung Tran
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- Remote Sensing, Energy, Satellite remote sensing, Climate

In vitro production of cellulase and xylanase was common among diverse freshwater ascomycetes and their hyphomycetous anamorphs. Production of enzymes involved in lignin degradation was rare. Most isolates were capable of causing mass loss in angiosperm wood, although values were low, at 10% during a 24-week period. A few isolates caused higher mass loss of up to 26.5%, and five of these were shown to solubilize significant amounts of lignin. This is the first report of lignin solubilization by freshwater fungi. Torula herbarum (hyphomycete) and Ophioceras dolichostomum (ascomycete) produced indices of lignin solubilization equivalent to those of terrestrial white-rot basidiomycetes. In all cases wood decay was 2.2-to 3-fold higher in exposed rather than submerged conditions.

- by Stephen Pointing
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- Microbiology, Microbial Ecology, Ecology, Fungi

The question posed in this paper is whether traditional Thai houses perform better than a typical contemporary Thai house in creating comfortable internal conditions. And if they do how is it possible for the contemporary house to benefit from the advantages presented in the design of the traditional house in terms of thermal performance while maintaining thermal comfort conditions for its occupants. The thermal performance of both types of buildings is therefore investigated, using a simulation model and based on a selection of thermal performance criteria of local traditional and contemporary house models in Thailand.

- by elena douvlou
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- Architectural Design, Thermal comfort, Thermal Performance, Regional Variation

The relative influence of habitat loss vs. habitat fragmentation per se (the breaking apart of habitat) on species distribution and abundance is a topic of debate. Although some theoretical studies predict a strong negative effect of fragmentation, consensus from empirical studies is that habitat fragmentation has weak effects compared with habitat loss and that these effects are as likely to be positive as negative. However, few empirical investigations of this issue have been conducted on tropical or wide-ranging species that may be strongly influenced by changes in patch size and edge that occur with increasing fragmentation. We tested the relative influence of habitat loss and fragmentation by examining occupancy of forest patches by 20 mid-and large-sized Neotropical mammal species in a fragmented landscape of northern Guatemala. We related patch occupancy of mammals to measures of habitat loss and fragmentation and compared the influence of these two factors while controlling for patch-level variables. Species responded strongly to both fragmentation and loss, and response to fragmentation generally was negative. Our findings support previous assumptions that conservation of large mammals in the tropics will require conservation strategies that go beyond prevention of habitat loss to also consider forest cohesion or other aspects of landscape configuration.

- by Lyn Branch
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- Demography, Mammals, Biological Sciences, Environmental Sciences

A review of the literature since 2009 reveals a staggering health and economic burden resulting from neglected tropical diseases in Panama and the six countries of Central America (referred to collectively here as 'Central America'). Particularly at risk are the 10.2million people in the region who live on less than $2 per day, mostly in Guatemala, Honduras, Nicaragua and El Salvador. Indigenous populations are especially vulnerable to neglected tropical diseases. Currently, more than 8million Central American children require mass drug treatments annually (or more frequently) for their intestinal helminth infections, while vector-borne diseases are widespread. Among the vector-borne parasitic infections, almost 40% of the population is at risk for malaria (mostly Plasmodium vivax infection), more than 800,000 people live with Chagas disease, and up to 39,000 people have cutaneous leishmaniasis. In contrast, an important recent success story is the elimination of onchocercia...

- by Maria Bottazzi
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- Microbiology, Zoology, Poverty, Central America
- by Arun Agrawal
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- Forestry, Ecosystem Services, Community Engagement & Participation, Tropical Ecology