Effect of high ambient temperature on behavior of sheep under semi-arid tropical environment.

Science.gov (United States)

De, Kalyan; Kumar, Davendra; Saxena, Vijay Kumar; Thirumurugan, Palanisamy; Naqvi, Syed Mohammed Khursheed

2017-07-01

High environmental temperature is a major constraint in sheep production under semi-arid tropical environment. Behavior is the earliest indicator of animal's adaptation and responses to the environmental alteration. Therefore, the objective of this study was to assess the effects of high ambient temperature on the behavior of sheep under a semi-arid tropical environment. The experiment was conducted for 6 weeks on 16 Malpura cross (Garole × Malpura × Malpura (GMM)) rams. The rams were divided equally into two groups, designated as C and T. The rams of C were kept in comfortable environmental conditions served as control. The rams of T were exposed to a different temperature at different hours of the day in a climatic chamber, to simulate a high environmental temperature of summer in semi-arid tropic. The behavioral observations were taken by direct instantaneous observation at 15-min intervals for each animal individually. The feeding, ruminating, standing, and lying behaviors were recorded twice a week from morning (0800 hours) to afternoon (1700 hours) for 6 weeks. Exposure of rams to high temperature (T) significantly (P behavior of sheep which is directed to circumvent the effect of the stressor.

Effect of high ambient temperature on behavior of sheep under semi-arid tropical environment

Science.gov (United States)

De, Kalyan; Kumar, Davendra; Saxena, Vijay Kumar; Thirumurugan, Palanisamy; Naqvi, Syed Mohammed Khursheed

2017-07-01

High environmental temperature is a major constraint in sheep production under semi-arid tropical environment. Behavior is the earliest indicator of animal's adaptation and responses to the environmental alteration. Therefore, the objective of this study was to assess the effects of high ambient temperature on the behavior of sheep under a semi-arid tropical environment. The experiment was conducted for 6 weeks on 16 Malpura cross (Garole × Malpura × Malpura (GMM)) rams. The rams were divided equally into two groups, designated as C and T. The rams of C were kept in comfortable environmental conditions served as control. The rams of T were exposed to a different temperature at different hours of the day in a climatic chamber, to simulate a high environmental temperature of summer in semi-arid tropic. The behavioral observations were taken by direct instantaneous observation at 15-min intervals for each animal individually. The feeding, ruminating, standing, and lying behaviors were recorded twice a week from morning (0800 hours) to afternoon (1700 hours) for 6 weeks. Exposure of rams to high temperature (T) significantly ( P animals of T spent significantly ( P behavior of sheep which is directed to circumvent the effect of the stressor.

Tropical Rainforests.

Science.gov (United States)

Nigh, Ronald B.; Nations, James D.

1980-01-01

Presented is a summary of scientific knowledge about the rainforest environment, a tropical ecosystem in danger of extermination. Topics include the current state of tropical rainforests, the causes of rainforest destruction, and alternatives of rainforest destruction. (BT)

Classroom Environment, Achievement Goals and Maths Performance: Gender Differences

Science.gov (United States)

Gherasim, Loredana Ruxandra; Butnaru, Simona; Mairean, Cornelia

2013-01-01

This study investigated how gender shapes the relationships between classroom environment, achievement goals and maths performance. Seventh-grade students ("N"?=?498) from five urban secondary schools filled in achievement goal orientations and classroom environment scales at the beginning of the second semester. Maths performance was…

The Next-Generation Goddard Convective-Stratiform Heating Algorithm: New Retrievals for Tropical and Extra-tropical Environments

Science.gov (United States)

Lang, S. E.; Tao, W. K.; Iguchi, T.

2017-12-01

The Goddard Convective-Stratiform Heating (or CSH) algorithm has been used to estimate cloud heating over the global Tropics using TRMM rainfall data and a set of look-up-tables (LUTs) derived from a series of multi-week cloud-resolving model (CRM) simulations using the Goddard Cumulus Ensemble model (GCE). These simulations link satellite observables (i.e., surface rainfall and stratiform fraction) with cloud heating profiles, which are not directly observable. However, with the launch of GPM in 2014, the range over which such algorithms can be applied has been extended from the Tropics into higher latitudes, including cold season and synoptic weather systems. In response, the CSH algorithm and its LUTs have been revised both to improve the retrievals in the Tropics as well as expand retrievals to higher latitudes. For the Tropics, the GCE simulations used to build the LUTs were upgraded using larger 2D model domains (512 vs 256 km) and a new, improved Goddard 4-ice scheme as well as expanded with additional cases (4 land and 6 ocean in total). The new tropical LUTs are also re-built using additional metrics. Besides surface type, conditional rain intensity and stratiform fraction, the new LUTs incorporate echo top heights and low-level (0-2 km) vertical reflectivity gradients. CSH retrievals in the Tropics based on the new LUTs show significant differences from previous iterations using TRMM data or the old LUT metrics. For the Extra-tropics, 6 NU-WRF simulations of synoptic events (3 East Coast and 3 West Coast), including snow, were used to build new extra-tropical CSH LUTs. The LUT metrics for the extra-tropics are based on radar characteristics and freezing level height. The extra-tropical retrievals are evaluated with a self-consistency check approach using the model heating as `truth,' and freezing level height is used to transition CSH retrievals from the Tropics to Extra-tropics. Retrieved zonal average heating structures in the Extra-tropics are

REGIONAL GEOLGICAL MAPPING IN TROPICAL ENVIRONMENTS USING LANDSAT TM AND SRTM REMOTE SENSING DATA

Directory of Open Access Journals (Sweden)

A. Beiranvand Pour

2015-10-01

Full Text Available Landsat Thematic Mapper (TM and Shuttle Radar Topography Mission (SRTM data were used to produce geological maps in tropical environments. Lineament, lithology and landform maps were produced for all states in peninsular Malaysia in this study. Kedah, Perak and Terengganu states have been selected as case studies to demonstrate the results of the data and techniques used. Directional filtering technique was applied to Landsat TM bands 4, 5 and 3 for lineament mapping. The lithology map was produced using Landsat TM bands combination consist of bands 4, 3 and 2. Digital elevation model and landform map were produced using SRTM data in 3 Dimension (3D and 2 Dimension (2D perspective views, respectively. The produced geological maps and the remote sensing data and methods applied in this study are mostly appropriate for hazard risk mapping applications and mineral exploration projects in the peninsular Malaysia and tropical environments.

Particular characteristics of atopic eczema in tropical environments. The Tropical Environment Control for Chronic Eczema and Molecular Assessment (TECCEMA) cohort study

OpenAIRE

Sánchez, Jorge; Sánchez, Andrés; Cardona, Ricardo

2017-01-01

Abstract: Background: Atopic dermatitis is a prevalent health problem in the world. Allergic sensitization is an important risk factor, but the roles of other factors, inherent in tropic region, are unknown. Objective: A cohort study was designed in a tropical city to investigate molecular and environmental risk factors for eczema, considering as particular features perennial exposure to mites, poor living conditions and others tropical characteristics. Methods: 433 patients were included ...

'Nikkei Global Environment Technology Prize' awarded to the joint research group on regeneration of tropical forest; Nettairin saisei kyodo kenkyu ga 'Nikkei chikyu kankyo gijutsusho' wo jusho

Energy Technology Data Exchange (ETDEWEB)

Watanabe, T. [Kansai Electric Power Co. Inc., Osaka (Japan)

1998-11-10

The tropical forest regeneration technology research group of Kansai Electric Power Company and Kansai Environment Center has been performing the research and development of tropical forest regeneration technology jointly with Indonesia since fiscal 1992. The group was awarded with the Global Environment Technology Prize from Nihon Keizai Shimbun, Inc. As a result of stringent examination on 97 applications, being two times as many as in usual years, the group received high evaluation on the originality, reality and possibility of proliferation of its research, and impacts given to the societies. Two other groups were also selected. The achievements were reported by the representative of the group in the award commemoration lecture at the global environment economist summit held by the Nikkei press the same day. Conventionally, afforestation done with considerable efforts has often been lost by forest fires and slash-and-burn farming, whereas the present research aims at establishing a comprehensive afforestation technology considering social and economic aspects, and CO2 fixation. As one of the choices of flexible measures as a result of the effect of forests having been recognized in COP3, frameworks for utilizing the mechanisms of joint implementation and clean resource development were introduced. Ever increasing expectations are placed on the achievements of the present research works. (NEDO)

Change in ocean subsurface environment to suppress tropical cyclone intensification under global warming

Science.gov (United States)

Huang, Ping; Lin, I. -I; Chou, Chia; Huang, Rong-Hui

2015-01-01

Tropical cyclones (TCs) are hazardous natural disasters. Because TC intensification is significantly controlled by atmosphere and ocean environments, changes in these environments may cause changes in TC intensity. Changes in surface and subsurface ocean conditions can both influence a TC's intensification. Regarding global warming, minimal exploration of the subsurface ocean has been undertaken. Here we investigate future subsurface ocean environment changes projected by 22 state-of-the-art climate models and suggest a suppressive effect of subsurface oceans on the intensification of future TCs. Under global warming, the subsurface vertical temperature profile can be sharpened in important TC regions, which may contribute to a stronger ocean coupling (cooling) effect during the intensification of future TCs. Regarding a TC, future subsurface ocean environments may be more suppressive than the existing subsurface ocean environments. This suppressive effect is not spatially uniform and may be weak in certain local areas. PMID:25982028

Estimation of some comfort parameters for sleeping environments in dry-tropical sub-Saharan Africa region

International Nuclear Information System (INIS)

Djongyang, Noël; Tchinda, René; Njomo, Donatien

2012-01-01

Highlights: ► Thermal comfort in sleeping environments in the sub-Saharan Africa is presented. ► Comfort charts for the dry-tropical regions were established. ► Total insulation values for bedding systems range between 0.81 clo and 0.94 clo. ► Thermoneutral operative temperature ranges between 29.5 °C and 31.7 °C. ► Thermoneutral air temperature ranges between 27.1 °C and 29.6 °C. - Abstract: A human being spends approximately one-third of his/her life in sleep. For an efficient and peaceful rest, he/she therefore needs some level of comfort. This includes acceptable environmental parameters as well as suitable bedding systems. While the theories of thermal comfort in workplaces at daytime are currently well established, research on thermal comfort for sleeping environment at night is limited. Further studies in relation with sleep are needed. This paper presents an investigation on thermal comfort in sleeping environments in the sub-Saharan Africa region. The comfort equation used is based on the energy balance of the human body derived from Fanger’s comfort model. Comfort charts for the dry-tropical sub-Saharan Africa region were established using indoor climatic conditions collected over five years in Ouagadougou (12°22′N, 1°32′W). Results obtained show that the suitable monthly total insulation values for bedding systems in the dry-tropical regions range between 0.81 clo and 0.94 clo. The thermoneutral operative temperature range between 29 °C and 32 °C, while the thermoneutral air temperature range between 27 °C and 30 °C.

Analysis of the environments of seven Mediterranean tropical-like storms using an axisymmetric, nonhydrostatic, cloud resolving model

Directory of Open Access Journals (Sweden)

L. Fita

2007-01-01

Full Text Available Tropical-like storms on the Mediterranean Sea are occasionally observed on satellite images, often with a clear eye surrounded by an axysimmetric cloud structure. These storms sometimes attain hurricane intensity and can severely affect coastal lands. A deep, cut-off, cold-core low is usually observed at mid-upper tropospheric levels in association with the development of these tropical-like systems. In this study we attempt to apply some tools previously used in studies of tropical hurricanes to characterise the environments in which seven known Mediterranean events developed. In particular, an axisymmetric, nonhydrostatic, cloud resolving model is applied to simulate the tropical-like storm genesis and evolution. Results are compared to surface observations when landfall occurred and with satellite microwave derived wind speed measurements over the sea. Finally, sensitivities of the numerical simulations to different factors (e.g. sea surface temperature, vertical humidity profile and size of the initial precursor of the storm are examined.

Bioindicators in the tropical forest of Kaiga environment

International Nuclear Information System (INIS)

Somashekarappa, H.M.; Narayana, Y.; Radhakrishna, A.P.; Karunakara, N.; Balakrishna, K.M.; Siddappa, K.

1996-01-01

Investigations on the natural and artificial fallout radionuclides 210 Po and 137 Cs and the primordial radionuclide 40 K in the prominent tree species of Western Ghat tropical forests near Kaiga have been carried out as a part of baseline background radiation studies in the environment of Kaiga where nuclear power reactors are being installed. The prominent tree species of the region Tectona grandis L.f. and Terminalia paniculata Roth., and the commonly available epiphytic plant species Pterobryopsis tumida (Hook.) Dix. and Cymbidium aliofolium (Lo) Swartz. were chosen and concentrations of 40 K, 210 Po and 137 Cs were measured employing well-established nuclear techniques. The different parts of Cumbidium aloifolium (Lo) Swartz. such as leaves, stem, etc. were analysed to understand the absorption mechanism of fallout radionuclides. From a careful analysis of the results, the epiphytic plant species are identified as bioindicators to monitor fallout radionuclides. (Author)

Daily variations in pathogenic bacterial populations in a monsoon influenced tropical environment

Digital Repository Service at National Institute of Oceanography (India)

Khandeparker, L.; Anil, A.C.; Naik, S.D.; Gaonkar, C.C.

and an assessment of the health of such an ecosystem benefits from high resolution observations. Virulent pathogenic Vibrio species are expected more frequently in tropical marine environments, since the virulence gene expression seems to increase at elevated... cells ml−1 (July 2009) to 5.9 x 107 cells ml−1 (February 2011) (Fig. 2b). Inter annual variations point out that the total bacterial abundance increased 5 from 2009 to 2011, while the viable bacterial numbers decreased. Complex physical, chemical...

Genetic by environment interaction for post weaning growth traits in tropical cattle

OpenAIRE

Navès, Michel; Menendez Buxadera, Alberto; Farant, Alain; Mandonnet, Nathalie

2006-01-01

Genetic by environment interactions for post weaning traits were studied in a local breed of cattle, well adapted to tropical conditions. After weaning, 444 beef calves of both sexes were separated within two management systems, either in intensive fattening or at pasture. The traits analysed included weights at standard age, of 365 days (W12), 455 days (W15) and 545 days (W18), and post weaning growth rates from weaning until 15 months (PWG15) or 18 months (PWG18). (Co)varianc...

Oilfield development and protection of natural resources within the tropical marine environment of the Rowley shelf, northwest Australia

International Nuclear Information System (INIS)

LeProvost, M.I.; Gordon, D.M.

1991-01-01

In recent years a number of oilfields have been developed in tropical waters of the Rowley Shelf, north-west Australia. Along with Bass Strait and the Timor Sea, this region is the focus for Australia's current oil exploration and production. It supports major coral and mangrove habitats and fishing grounds sensitive to the effects of oil pollution. This paper provides a synthesis of the Rowley Shelf marine environment and reviews procedures protecting the marine resources of the region from the effects of oil spills. Recent government and industry initiatives for improving the protection of the environment are outlined and discussed on the basis of the improved understanding of the marine resources and experience being gained in oil spill contingency planning. The tropical habitats of the Rowley Shelf occur within the Indo-Pacific Zoogeographic Region, therefore experience gained in Western Australia is applicable to similar environments in the South East Asian region

Tropical Rainforests: A Case Study of UK, 13-Year-Olds' Knowledge and Understanding of These Environments

Science.gov (United States)

Dove, Jane

2012-01-01

Tropical rainforests are biologically rich ecosystems, which are threatened by a variety of different human activities. This study focuses on students' knowledge and understanding of rainforest locations, their reasons for protecting these environments and their familiarity with selected concepts about rainforest vegetation and soil. These…

Emerging and Reemerging Neglected Tropical Diseases: a Review of Key Characteristics, Risk Factors, and the Policy and Innovation Environment

Science.gov (United States)

Liang, Bryan A.; Cuomo, Raphael; Hafen, Ryan; Brouwer, Kimberly C.; Lee, Daniel E.

2014-01-01

SUMMARY In global health, critical challenges have arisen from infectious diseases, including the emergence and reemergence of old and new infectious diseases. Emergence and reemergence are accelerated by rapid human development, including numerous changes in demographics, populations, and the environment. This has also led to zoonoses in the changing human-animal ecosystem, which are impacted by a growing globalized society where pathogens do not recognize geopolitical borders. Within this context, neglected tropical infectious diseases have historically lacked adequate attention in international public health efforts, leading to insufficient prevention and treatment options. This subset of 17 infectious tropical diseases disproportionately impacts the world's poorest, represents a significant and underappreciated global disease burden, and is a major barrier to development efforts to alleviate poverty and improve human health. Neglected tropical diseases that are also categorized as emerging or reemerging infectious diseases are an even more serious threat and have not been adequately examined or discussed in terms of their unique risk characteristics. This review sets out to identify emerging and reemerging neglected tropical diseases and explore the policy and innovation environment that could hamper or enable control efforts. Through this examination, we hope to raise awareness and guide potential approaches to addressing this global health concern. PMID:25278579

The relative stability of prehistorical geographic environment in China's tropics on the basis of archaeology

Institute of Scientific and Technical Information of China (English)

无

2002-01-01

According to archaeological data from about sixty samples the relative stability ofphysical and human geographical environment in the tropical zone of China is discussed in thispaper. Because of the superior natural environment, sufficient food resources and a sparsepopulation resulting in the absence of social requirement to transform the productive forces, theadvancement of economy and society was stagnated during prehistorical period in China's tropics.Compared with northern China, the appearance of ground stone tool stagnated about 3,000 years,the beginning of Bronze Age, about 1,000 years, and the agriculture, 2,500-3,000 years. The noceramics age continued till the early Neolithic Age and the appearance of colour or white ceramicswas 2,000 years later than that in northern China. The life form of migration to gather and to huntcontinued till the middle Neolithic Age, and the fixed settlement based on agriculture 1,000-2,000years stagnated. The clan commune just appeared at the end of the Neolithic Age which was 2,000-3,000 years later than that in northern China.

Impact of foliage on LoRa 433MHz propagation in tropical environment

Science.gov (United States)

Ahmad, Khairol Amali; Salleh, Mohd Sharil; Segaran, Jivitraa Devi; Hashim, Fakroul Ridzuan

2018-02-01

LoRa is being considered as one of the promising system for Low-Power-Wide-Area-Network (LPWAN) to support the growth of Internet of Things (IoT) applications. Designed to operate in the industrial, scientific and medical (ISM) bands, LoRa had been tested and evaluated mainly in Europe and US in the 868 MHz and 915 MHz modulation bands. Using chirp spread spectrum technology, LoRa is expected to be robust against degredation. This paper provides some early results in the performance of LoRa signal propagation of 433 MHz modulation in tropical foliage environments.

A critical assessment of the JULES land surface model hydrology for humid tropical environments

Science.gov (United States)

Zulkafli, Z.; Buytaert, W.; Onof, C.; Lavado, W.; Guyot, J. L.

2013-03-01

Global land surface models (LSMs) such as the Joint UK Land Environment Simulator (JULES) are originally developed to provide surface boundary conditions for climate models. They are increasingly used for hydrological simulation, for instance to simulate the impacts of land use changes and other perturbations on the water cycle. This study investigates how well such models represent the major hydrological fluxes at the relevant spatial and temporal scales - an important question for reliable model applications in poorly understood, data-scarce environments. The JULES-LSM is implemented in a 360 000 km2 humid tropical mountain basin of the Peruvian Andes-Amazon at 12-km grid resolution, forced with daily satellite and climate reanalysis data. The simulations are evaluated using conventional discharge-based evaluation methods, and by further comparing the magnitude and internal variability of the basin surface fluxes such as evapotranspiration, throughfall, and surface and subsurface runoff of the model with those observed in similar environments elsewhere. We find reasonably positive model efficiencies and high correlations between the simulated and observed streamflows, but high root-mean-square errors affecting the performance in smaller, upper sub-basins. We attribute this to errors in the water balance and JULES-LSM's inability to model baseflow. We also found a tendency to under-represent the high evapotranspiration rates of the region. We conclude that strategies to improve the representation of tropical systems to be (1) addressing errors in the forcing and (2) incorporating local wetland and regional floodplain in the subsurface representation.

Analysis agriculture's impact in a system of lakes on a karst environment with tropical climate.

Science.gov (United States)

Olea Olea, Selene; Escolero Fuentes, Oscar

2015-04-01

This paper has as main object to analyze the impact of agriculture in the water quality of the "Lagos de Montebello" area; which is located in the Southeast of Mexico. This area is prominent by its tropical climate and a karstic environment. The issue arises in a lake system affected by pollution in the later years, which has turned its former clear water into a highly sedimented muddy water in the topographically lower terrains while no polluted on the higher ones; therefore it is intended to determine if the rise in agricultural activity in the lower terrains has induced this phenomenon. The impact of agriculture has been historically studied in temperate climates with karstic environments; nevertheless it has not been very well studied in tropical climates; which are the reason of this proposal to perform a study to analyze the impact of the intensive agriculture running in the area. To develop this project we studied the area regarding to the types of crops that has being established in the zone, being mostly tomato, corn, and bean; and the fertilizers and pesticides applied to them. A groundwater monitoring plan was designed with a variety of phases such as: piezometers building, measurement of groundwater levels, measurement of field parameters, with a two months intervals (Ph, temperature, electric conductivity, total dissolved solids), and water samplings for laboratory analysis (major ions, nutrients, total organic carbon, pesticides) at twice a year, once during rainy season and then on drought. The rates of pollution agents infiltration depends on the type of soil retention and volume of water. The materials found in the soil by the piezometers are clay, silt, sand and variations between them. We determined that the geochemical qualities of the groundwater vary from calcic bicarbonate to calcic sulfated. The results reached with this monitoring provides a preliminary diagnosis on the possible causes and other implications that intensive agriculture in a

A novel bioassay using the barnacle Amphibalanus amphitrite to evaluate chronic effects of aluminium, gallium and molybdenum in tropical marine receiving environments.

Science.gov (United States)

van Dam, Joost W; Trenfield, Melanie A; Harries, Simon J; Streten, Claire; Harford, Andrew J; Parry, David; van Dam, Rick A

2016-11-15

A need exists for appropriate tools to evaluate risk and monitor potential effects of contaminants in tropical marine environments, as currently impact assessments are conducted by non-representative approaches. Here, a novel bioassay is presented that allows for the estimation of the chronic toxicity of contaminants in receiving tropical marine environments. The bioassay is conducted using planktonic larvae of the barnacle Amphibalanus amphitrite and is targeted at generating environmentally relevant, chronic toxicity data for water quality guideline derivation or compliance testing. The developmental endpoint demonstrated a consistently high control performance, validated through the use of copper as a reference toxicant. In addition, the biological effects of aluminium, gallium and molybdenum were assessed. The endpoint expressed high sensitivity to copper and moderate sensitivity to aluminium, whereas gallium and molybdenum exhibited no discernible effects, even at high concentrations, providing valuable information on the toxicity of these elements in tropical marine waters. Crown Copyright © 2016. Published by Elsevier Ltd. All rights reserved.

Achievements and lessons learned from the Benguela Environment ...

African Journals Online (AJOL)

The founding of BENEFIT, its organisational structures, and the way in which the projects were planned, formulated and executed through these structures are outlined. The major findings and other achievements of the research on fish resources, the environment and the linkages between them are discussed under these ...

Learning Environment Facilitating Educational Achievements of Teenagers

OpenAIRE

Šūmane, Ilze

2012-01-01

ABSTRACT. The doctoral thesis of Ilze Šūmane in pedagogy science, school pedagogy sub-discipline ”Learning environment facilitating educational achievements of teenagers” was worked out in the Department of Pedagogy, Faculty of Pedagogy, Psychology and Arts, University of Latvia, under the supervision of Dr.paed., professor Rudīte Andersone from2001 till 2011. The topicality of the research determined by the necessity to improve quality learning and education. During an effective study ...

The effects of different learning environments on students' motivation for learning and their achievement.

Science.gov (United States)

Baeten, Marlies; Dochy, Filip; Struyven, Katrien

2013-09-01

Research in higher education on the effects of student-centred versus lecture-based learning environments generally does not take into account the psychological need support provided in these learning environments. From a self-determination theory perspective, need support is important to study because it has been associated with benefits such as autonomous motivation and achievement. The purpose of the study is to investigate the effects of different learning environments on students' motivation for learning and achievement, while taking into account the perceived need support. First-year student teachers (N= 1,098) studying a child development course completed questionnaires assessing motivation and perceived need support. In addition, a prior knowledge test and case-based assessment were administered. A quasi-experimental pre-test/post-test design was set up consisting of four learning environments: (1) lectures, (2) case-based learning (CBL), (3) alternation of lectures and CBL, and (4) gradual implementation with lectures making way for CBL. Autonomous motivation and achievement were higher in the gradually implemented CBL environment, compared to the CBL environment. Concerning achievement, two additional effects were found; students in the lecture-based learning environment scored higher than students in the CBL environment, and students in the gradually implemented CBL environment scored higher than students in the alternated learning environment. Additionally, perceived need support was positively related to autonomous motivation, and negatively to controlled motivation. The study shows the importance of gradually introducing students to CBL, in terms of their autonomous motivation and achievement. Moreover, the study emphasizes the importance of perceived need support for students' motivation. © 2012 The British Psychological Society.

Comparison of methods for generating typical meteorological year using meteorological data from a tropical environment

Energy Technology Data Exchange (ETDEWEB)

Janjai, S.; Deeyai, P. [Laboratory of Tropical Atmospheric Physics, Department of Physics, Faculty of Science, Silpakorn University, Nakhon Pathom 73000 (Thailand)

2009-04-15

This paper presents the comparison of methods for generating typical meteorological year (TMY) data set using a 10-year period of meteorological data from four stations in a tropical environment of Thailand. These methods are the Sadia National Laboratory method, the Danish method and the Festa and Ratto method. In investigating their performance, these methods were employed to generate TMYs for each station. For all parameters of the TMYs and the stations, statistical test indicates that there is no significant difference between the 10-year average values of these parameters and the corresponding average values from TMY generated from each method. The TMY obtained from each method was also used as input data to simulate two solar water heating systems and two photovoltaic systems with different sizes at the four stations by using the TRNSYS simulation program. Solar fractions and electrical output calculated using TMYs are in good agreement with those computed employing the 10-year period hourly meteorological data. It is concluded that the performance of the three methods has no significant difference for all stations under this investigation. Due to its simplicity, the method of Sandia National Laboratories is recommended for the generation of TMY for this tropical environment. The TMYs developed in this work can be used for solar energy and energy conservation applications at the four locations in Thailand. (author)

Teaching science in a technology rich environment: Probeware's effect on student attitude and achievement

Science.gov (United States)

Zelmanowicz, Marc

Purpose The use of technology in the science classroom has been a major part of the initiative toward increasing student attitude and achievement in Science, Technology, Education and Math [STEM] education in the United States. The purpose of this study was to determine the extent to which the use of probeware in a high school science living environment classroom impacts student attitude towards science and/or student achievement on standards-based assessments. This study sought to answer the following quantitative questions with a qualitative component: To what extent does the use of probeware in a high school level living environment course influence student attitudes toward science compared to students who are not using probeware? What is the impact, if any, on student achievement in a living environment course, as measured by New York State Living Environment Regents [NYSLER] exam grades, between students who use probeware and students who do not? Is there a significant difference between the two groups with regard to achieving mastery on the NYSLER exam? Sample The participants in the study were Living Environment students of a suburban high school outside of New York City. Methods The quasiexperimental study examined the effects of the replacement of traditional scientific equipment with probeware on student attitude and achievement in a living environment classroom. Student attitude was measured by the modified Attitude Toward Science Inventory [mATSI] and student achievement was measured by the New York State Living Environment Regents [NSLER] Exam. Descriptive statistics, ANCOVA and hierarchical regression analysis were conducted to answer the research questions in this study. A qualitative component was included to enhance the understanding of the quantitative analysis. Major Findings Through this study, results demonstrated a statistically significant impact of probeware on student attitude, but did not show a statistically significant impact of

Precipitation patterns and moisture fluxes in a sandy, tropical environment with a shallow water table

Science.gov (United States)

Minihane, M. R.; Freyberg, D. L.

2011-08-01

Identifying the dominant mechanisms controlling recharge in shallow sandy soils in tropical climates has received relatively little attention. Given the expansion of coastal fill using marine sands and the growth of coastal populations throughout the tropics, there is a need to better understand the nature of water balances in these settings. We use time series of field observations at a coastal landfill in Singapore coupled with numerical modeling using the Richards' equation to examine the impact of precipitation patterns on soil moisture dynamics, including percolation past the root zone and recharge, in such an environment. A threshold in total precipitation event depth, much more so than peak precipitation intensity, is the strongest event control on recharge. However, shallow antecedent moisture, and therefore the timing between events along with the seasonal depth to water table, also play significant roles in determining recharge amounts. For example, at our field site, precipitation events of less than 3 mm per event yield little to no direct recharge, but for larger events, moisture content changes below the root zone are linearly correlated to the product of the average antecedent moisture content and the total event precipitation. Therefore, water resources planners need to consider identifying threshold precipitation volumes, along with the multiple time scales that capture variability in event antecedent conditions and storm frequency in assessing the role of recharge in coastal water balances in tropical settings.

Relationships among constructivist learning environment perceptions, motivational beliefs, self-regulation and science achievement

Science.gov (United States)

Kingir, Sevgi; Tas, Yasemin; Gok, Gulsum; Sungur Vural, Semra

2013-11-01

Background. There are attempts to integrate learning environment research with motivation and self-regulation research that considers social context influences an individual's motivation, self-regulation and, in turn, academic performance. Purpose. This study explored the relationships among constructivist learning environment perception variables (personal relevance, uncertainty, shared control, critical voice, student negotiation), motivational beliefs (self-efficacy, intrinsic interest, goal orientation), self-regulation, and science achievement. Sample. The sample for this study comprised 802 Grade 8 students from 14 public middle schools in a district of Ankara in Turkey. Design and methods. Students were administered 4 instruments: Constructivist Learning Environment Survey, Goal Achievement Questionnaire, Motivated Strategies for Learning Questionnaire, and Science Achievement Test. LISREL 8.7 program with SIMPLIS programming language was used to test the conceptual model. Providing appropriate fit indices for the proposed model, the standardized path coefficients for direct effects were examined. Results. At least one dimension of the constructivist learning environment was associated with students' intrinsic interest, goal orientation, self-efficacy, self-regulation, and science achievement. Self-efficacy emerged as the strongest predictor of both mastery and performance avoidance goals rather than the approach goals. Intrinsic value was found to be significantly linked to science achievement through its effect on self-regulation. The relationships between self-efficacy and self-regulation and between goal orientation and science achievement were not significant. Conclusion. In a classroom environment supporting student autonomy and control, students tend to develop higher interest in tasks, use more self-regulatory strategies, and demonstrate higher academic performance. Science teachers are highly recommended to consider these findings when designing

DETERMINATION OF OPTIMUM THREONINE REQUIREMENTS OF JAPANESE QUAIL (Coturnix coturnix japonica CHICKS REARED UNDER TROPICAL ENVIRONMENT

Directory of Open Access Journals (Sweden)

Isaac Samuel

2017-12-01

Full Text Available Threonine, like most amino acids, is traditionally noted for its role in protein synthesis. However, dietary threonine concentration required for the maximum performance of Japanese quails is yet to be determined, therefore, a study was conducted to determine the optimum threonine requirement of Japanese quail chicks in the tropical environment. A total of four hundred and fifty, two weeks old quail chicks (mixed sexes were randomly allocated to five dietary treatments (0.67, 0.81, 0.95, 1.08 and 1.22 % total threonine and replicated thrice in a completely randomized design (CRD. There were no significant differences (P>0.05 in average weight gain, average feed intake, feed conversion ratio and age at first lay of quails fed the dietary treatments. Weight of first egg laid was significantly (P0.05 similar for all treatments. There were significant differences (P0.05. It was concluded that the performance of birds were not influenced by the dietary treatments up to the highest dietary level of threonine studied (1.22%. Therefore, it is possible that the optimum dietary level of threonine may be above 1.22 %. Further studies will be necessary to establish higher doses of dietary threonine requirement of Japanese quails reared under tropical climatic environment.

Ethiopia and its steps to mobilize resources to achieve 2020 elimination and control goals for neglected tropical diseases webs joined can tie a lion.

Science.gov (United States)

Mengitsu, Belete; Shafi, Oumer; Kebede, Biruck; Kebede, Fikreab; Worku, Dagemlidet T; Herero, Merce; French, Michael; Kebede, Biruk; Mackenzie, Charles; Martindale, Sarah; Kebede, Zeyede; Hirpa, Tigist; Frawley, Hannah; Crowley, Kathryn; O'Neil, Maggie; McPherson, Scott

2016-03-01

In June 2013, at the launch of its National Neglected Tropical Disease (NTD) Master Plan, the Ethiopian government pledged to achieve WHO NTD elimination and control targets by 2020. With an estimated 80 million people living in areas where one or more NTDs are endemic, this goal presented an enormous challenge for the Federal Ministry of Health. However, as of September 2015, the Federal Ministry of Health has managed to mobilize support to implement mass drug administration in 84% of the trachoma endemic districts and 100% of the endemic districts for onchocerciasis, lymphatic filariasis, soil-transmitted helminthes and schistosomiasis. The national program still is facing large gaps in its podoconiosis and leishmaniasis programs, and it faces significant other challenges to stay on track for 2020 targets. However, this unprecedented scale-up in support was achieved through significant government investment in NTD interventions and creative coordination between donors and implementing partners, which may provide valuable lessons for other national NTD programs trying to achieve nationwide coverage. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Prospects and Challenges in tropical isotope dendroclimatology

Science.gov (United States)

Evans, M. N.; Anchukaitis, K. J.; White, S. R.; Ektvedt, T. M.; Penniston, R. C.; Rheaume, M. M.; Bowman, D. M.

2008-12-01

We review a stable isotope-based approach to the development, modeling, interpretation, and analysis of hydrometeorological estimates from tropical trees. The strategy overcomes the common problem of missing, intermittent or non-annual ring structure in tropical trees by relying instead on the observation of the annual wet-dry seasonality typical to tropical environments as mirrored in the oxygen isotopic composition of wood-derived α-cellulose. We explore regions for which forward modeling of the proxy system would expect us to resolve hydrometeorological variations associated with the El Niño-Southern Oscillation (ENSO) phenomenon, rather than being limited to regions with tree species or environments producing verifiable annual ring chronologies. A modified protocol allows for rapid, simple and non-toxic micro-extraction of pure α-cellulose, which is isotopically indistinguishable from that produced by more classical means. We describe a new reactor for the pyrolysis of α-cellulose in an induction heater, which permits isotopic analysis of α-cellulose samples as small as 30μg, and as many as 100 automated sample analyses per day. A forward model adapted for tropical environments can be used to test and refine the interpretation of the isotopic data, and to predict locales for which we should be able to maximize the paleoclimatic potential of future sample collections. We have found the modeled isotopic chronometer and raingage in agreement with independent chronological controls in a variety of environments and tree species in Costa Rica, Indonesia, Brazil, Peru and Australia. Development of long hydrometeorological records from the terrestrial tropics is underway not only by our group, but by a growing number of collaborators and colleagues. Together we should be able to build a network of paleoprecipitation records and better understand the linkages between tropical surface ocean temperatures and large-scale drought.

Atmospheric Corrosion Behavior of 2A12 Aluminum Alloy in a Tropical Marine Environment

Directory of Open Access Journals (Sweden)

Zhongyu Cui

2015-01-01

Full Text Available Atmospheric corrosion behavior of 2A12 aluminum alloy exposed to a tropical marine environment for 4 years was investigated. Weight loss of 2A12 alloy in the log-log coordinates can be well fitted with two linear segments, attributing to the evolution of the corrosion products. EIS results indicate that the corrosion product layer formed on the specimens exposed for 12 months or longer presents a good barrier effect. Corrosion morphology changes from pitting corrosion to severe intergranular corrosion with the extension of exposure time, resulting in the reduction of the mechanical properties.

Atmospheric Corrosion Behavior and Mechanism of a Ni-Advanced Weathering Steel in Simulated Tropical Marine Environment

Science.gov (United States)

Wu, Wei; Zeng, Zhongping; Cheng, Xuequn; Li, Xiaogang; Liu, Bo

2017-12-01

Corrosion behavior of Ni-advanced weathering steel, as well as carbon steel and conventional weathering steel, in a simulated tropical marine atmosphere was studied by field exposure and indoor simulation tests. Meanwhile, morphology and composition of corrosion products formed on the exposed steels were surveyed through scanning electron microscopy, energy-dispersive x-ray spectroscopy and x-ray diffraction. Results indicated that the additive Ni in weathering steel played an important role during the corrosion process, which took part in the formation of corrosion products, enriched in the inner rust layer and promoted the transformation from loose γ-FeOOH to dense α-FeOOH. As a result, the main aggressive ion, i.e., Cl-, was effectively separated in the outer rust layer which leads to the lowest corrosion rate among these tested steels. Thus, the resistance of Ni-advanced weathering steel to atmospheric corrosion was significantly improved in a simulated tropical marine environment.

Preliminary comparison of different immune and production components in local and imported Saanen goats reared under a sub-tropical environment.

Science.gov (United States)

Barbour, Elie K; Itani, Houssam H; Sleiman, Fawwak T; Saade, Maya F; Harakeh, Steve; Nour, Afif M Abdel; Shaib, Houssam A

2012-01-01

Three objectives were included in this research work. The first objective compared different immune components in healthy mature males, mature females, and female kids of local and imported Saanen goats, reared under a sub-tropical environment. The significantly differing immune components were the blood monocyte percent, blood CD8 count, and the total white blood cell count. The second objective compared the performance of Saanen versus local does. The means of the milk yield and prolificacy of the imported Saanen does were significantly higher than those of the local does (pgoats on protection potential against prevalent diseases in the sub-tropical zone of the eastern Mediterranean countries is discussed.

Influence of season and sex on hemato-biochemical traits in adult turkeys under arid tropical environment

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Anil Gattani

2016-05-01

Full Text Available Aim: The objective of this study was to evaluate the effect of season and sex on hemato-biochemical parameters of turkey (Meleagris gallopavo in the arid tropical environment. Materials and Methods: The experiment was conducted on 20-week old turkeys consisting of 20 males and 20 females. Blood was collected from all turkeys during January and May. Hemoglobin (Hb, red blood cell (RBC, packed cell volume (PCV, mean corpuscular volume (MCV, mean corpuscular hemoglobin (MCH, and mean corpuscular hemoglobin concentration (MCHC were estimated in whole blood and glucose, protein, albumin, globulin, A/G ratio, calcium, phosphorus, alanine aminotransferase (ALT, and aspartate aminotransferase (AST in serum. Result: Season has significant (p<0.05 effect on Hb concentration, RBC, and PCV in both male and female. Male has significantly higher (p<0.05 Hb concentration, RBC, and PCV. There is no significant effect of sex, and season was observed on MCV, MCH, and MCHC. Glucose, protein, albumin, globulin, and A/G ratio were significantly (p<0.05 affected by season and sex. AST and ALT were significantly (p<0.05 affected by season in both sexes. There is no significant difference was recorded on calcium, phosphorus due to season and sex. Conclusion: Under arid tropical environment, turkey hemato-biochemical parameters are influenced by both sex and season.

The Next-Generation Goddard Convective-Stratiform Heating Algorithm: New Model Simulations for Tropical and Continental Summertime Environments

Science.gov (United States)

Lang, S. E.; Tao, W. K.; Wu, D.

2016-12-01

The Goddard Convective-Stratiform Heating (or CSH) algorithm is used to retrieve estimates of cloud heating over the global Tropics using TRMM rainfall data and a set of look-up-tables (LUTs) derived from a series of multi-week cloud-resolving model (CRM) simulations using the Goddard Cumulus Ensemble model (or GCE). These simulations link satellite observables (i.e., surface rainfall and stratiform fraction) with cloud heating profiles, which are not directly observable. The strength of the algorithm relies in part on the representativeness of the simulations; more realistic simulations provide a stronger link between the observables and simulated heating profiles. The current "TRMM" version of the CSH algorithm relies on 2D GCE simulations using an improved version of the Goddard 3-class ice scheme (3ICE), a moderate-sized domain, and 1-km horizontal resolution. Updating the LUTs, which are suitable for tropical and continental summertime environments requires new, more realistic GCE simulations. New simulations are performed using a new, improved 4-class ice scheme, which has been shown to outperform the 3ICE scheme, especially for intense convection. Additional grid configurations are also tested and evaluated to find the best overall setup to for re-deriving and updating the CSH tropical/summertime LUTs.

Estimation of leaf area in tropical maize

NARCIS (Netherlands)

Elings, A.

2000-01-01

Leaf area development of six tropical maize cultivars grown in 1995 and 1996 in several tropical environments in Mexico (both favourable and moisture-and N-limited) was observed and analysed. First, the validity of a bell-shaped curve describing the area of individual leaves as a function of leaf

Ability of crassulacean acid metabolism plants to overcome interacting stresses in tropical environments.

Science.gov (United States)

Lüttge, Ulrich

2010-01-01

Single stressors such as scarcity of water and extreme temperatures dominate the struggle for life in severely dry desert ecosystems or cold polar regions and at high elevations. In contrast, stress in the tropics typically arises from a dynamic network of interacting stressors, such as availability of water, CO(2), light and nutrients, temperature and salinity. This requires more plastic spatio-temporal responsiveness and versatility in the acquisition and defence of ecological niches. The mode of photosynthesis of crassulacean acid metabolism (CAM) is described and its flexible expression endows plants with powerful strategies for both acclimation and adaptation. Thus, CAM plants are able to inhabit many diverse habitats in the tropics and are not, as commonly thought, successful predominantly in dry, high-insolation habitats. Typical tropical CAM habitats or ecosystems include exposed lava fields, rock outcrops of inselbergs, salinas, savannas, restingas, high-altitude páramos, dry forests and moist forests. Morphotypical and physiotypical plasticity of CAM phenotypes allow a wide ecophysiological amplitude of niche occupation in the tropics. Physiological and biochemical plasticity appear more responsive by having more readily reversible variations in performance than do morphological adaptations. This makes CAM plants particularly fit for the multi-factor stressor networks of tropical forests. Thus, while the physiognomy of semi-deserts outside the tropics is often determined by tall succulent CAM plants, tropical forests house many more CAM plants in terms of quantity (biomass) and quality (species diversity).

Spatial Distributions of Tropical Cyclone Tornadoes by Intensity and Size Characteristics

OpenAIRE

Todd W. Moore; Nicholas J. Sokol; Robert A. Blume

2017-01-01

Tropical cyclones that make landfall often spawn tornadoes. Previous studies have shown that these tornadoes are not uniformly distributed in the United States or in the tropical cyclone environment. They show that tornadoes tend to occur relatively close to the coastline and that they tend to cluster to the east-of-center in the tropical cyclone environment, particularly in the northeast and east-of-center quadrants. This study contributes to these studies by analyzing the spatial distributi...

The Scientific Development of the Physiology of Plants in the American Tropics

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Marco V. Gutiérrez

2002-06-01

Full Text Available This paper is a research and journalistic work that summarizes and synthesizes the scientific development of the physiology of plants in the American tropics, also known as the Neotropics. It contains the contributions of numerous biologists interested in the physiology of tropical plants. The fabulous structural and functional diversity of tropical forests is still the major driver of research in this field. Classical physiological work involving tropical plants, such as the discovery of C4 photosynthesis in sugarcane, is invoked to exemplify the historical and current importance of physiological research in the tropics, and its applications in agriculture, forestry and conservation. An historical background describing the early and more recent development of a tradition on the physiological study of tropical plants is followed by a summary of the research conducted on the physiology of tropical crops. Common areas of interest and influence between the fields of crop physiology and plant ecophysiology are identified and exemplified with problems on the environmental physiology of crops like coffee and cassava. The physiology of tropical forest plants is discussed in terms of its contributions to general plant physiological knowledge in areas such as photosynthetic metabolism and plant water relations. Despite the impressive technical advances achieved during the past decade, the importance of continuous development of appropriate instrumentation to study and measure the physiology of plants in situ is stressed. Although the basic metabolic processes that underlie the mechanisms of plant responses to the environment are probably highly conserved and qualitatively similar among tropical and temperate plants, it is also apparent that tropical plants exhibit metabolic peculiarities. These include aspects of photosynthetic metabolism, phloem transport physiology, sensitivity to low temperatures, reproduction, responses to climatic seasonality, and a

Single-Sex versus Coeducational Environment and Achievement in Adolescent Females.

Science.gov (United States)

Monaco, Nanci M.; Gaier, Eugene L.

1992-01-01

Suggests that, if high school environment reduces discrepancy between conflicting roles, adolescent females may place greater emphasis on achievement. Within this context, explores differential benefits of single-sex and coeducational schooling. Issue explored is not whether one is preferable for females; rather, the concern is how each of these…

The Role of Soil Amendment on Tropical Post Tin Mining Area in Bangka Island Indonesia for Dignified and Sustainable Environment and Life

Science.gov (United States)

Agus, C.; Wulandari, D.; Primananda, E.; Hendryan, A.; Harianja, V.

2017-08-01

Openly tropical tin mining in Bangka Island Indonesia expose heavy metal that had been buried became a part of our environment and life. This has become a major cause of land degradation and severe local-global environmental damages. This study aims to accelerate reconsolidation of degraded ecosystems on the former tin mine land, to increase land productivity and dignified environment through appropriate rehabilitation technology on marginal land that is inexpensive, environmentally friendly and sustainable. This study is a part of a roadmap research activities on the rehabilitation of degraded land in tropical ecosystem, that consist of (a) characterization of degraded tin mining lands through the determination of chemistry, physics, biology and mineral soil properties, (b) introducing multi-function pioneers plant for acceleration of peak pioneer plant in the reestablishment of degraded tin mining ecosystem (c) management of natural soil amendment (volcanic ash, organic waste materials and legume cover crop as a material for soil amelioration to increase land productivity, (d) role of biotechnology through the application of local bio-fertilizer (mycorrhizae, phosphate soluble bacteria, rhizobium). Soil from post tropical tin mining acid soil (pH 4.97) that dominated by sand particles (88%) with very low cation exchange capacity, very low nutrient contents (available and total-N, P, K, Ca, Mg) and high toxicity of Zn, Cu, B, Cd and Ti, but still have low toxicity of Al, Fe, Mn, Mo, Pb, As. Soil amendment of biogas and volcanic ash could improve soil quality by increasing of better pH, high available-P and cation exchange capacity and maintained their low toxicity. The growth (high, diameter, biomass, top-root ratio) of exotic pioneer plant of Kemiri sunan (Reutealis trisperma) increased in the better soil quality that caused by application of proper soil amendment. The grand concept and appropriate technology for rehabilitation of degraded tin-mining land

PAIR INFLUENCE OF WIND SPEED AND MEAN RADIANT TEMPERATURE ON OUTDOOR THERMAL COMFORT OF HUMID TROPICAL ENVIRONMENT

Directory of Open Access Journals (Sweden)

Sangkertadi Sangkertadi

2016-01-01

Full Text Available The purposes of this article is to explore knowledge of outdoor thermal comfort in humid tropical environment for urban activities especially for people in walking activity, and those who stationary/seated with moderate action. It will be characterized the pair influence of wind speed and radiant temperature on the outdoor thermal comfort. Many of researchers stated that those two microclimate variables give significant role on outdoor thermal comfort in tropical humid area. Outdoor Tropical Comfort (OTC model was used for simulation in this study. The model output is comfort scale that refers on ASHRAE definition. The model consists of two regression equations with variables of air temperature, globe temperature, wind speed, humidity and body posture, for two types of activity: walking and seated. From the results it can be stated that there is significant role of wind speed to reduce mean radiant temperature and globe temperature, when the velocity is elevated from 0.5 m/s to 2 m/s. However, the wind has not play significant role when the speed is changed from 2 m/s to 3.5 m/s. The results of the study may inspire us to implement effectiveness of electrical-fan equipment for outdoor space in order to get optimum wind speed, coupled with optimum design of shading devices to minimize radiant temperature for thermal comfort.

Tropical Agro-Sciences

International Nuclear Information System (INIS)

Anon.

1977-01-01

The Tropical Agro-Sciences Division has two functions: conduct research on the impact of air pollution on tropical agricultural and to provide training to UPR graduate students and visiting scientists. Since the reorientation of the Center's interests under ERDA, the Division has directed its research activities, with particular emphasis on the effects of atmospheric pollution on tropical agriculture in the Guayanilla-Penuelas region, which has a fossil-fuel power plant, petroleum refineries, and associated industries. This new area of research is important to ERDA because the knowledge gained regarding the effects of air pollution related to energy technology on the agricultural environment and productivity will be useful in planning future energy developments. Information about the potential harm of air pollutants to man through the food chain and about ways of alleviating their impact on agriculture are of practical importance. Studies of the mechanisms involved in pollution injury, protection, and tolerance are of basic significance

Methane Dynamics in a Tropical Serpentinizing Environment: The Santa Elena Ophiolite, Costa Rica

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Melitza Crespo-Medina

2017-05-01

Full Text Available Uplifted ultramafic rocks represent an important vector for the transfer of carbon and reducing power from the deep subsurface into the biosphere and potentially support microbial life through serpentinization. This process has a strong influence upon the production of hydrogen and methane, which can be subsequently consumed by microbial communities. The Santa Elena Ophiolite (SEO on the northwestern Pacific coast of Costa Rica comprises ~250 km2 of ultramafic rocks and mafic associations. The climatic conditions, consisting of strongly contrasting wet and dry seasons, make the SEO a unique hydrogeological setting, where water-rock reactions are enhanced by large storm events (up to 200 mm in a single storm. Previous work on hyperalkaline spring fluids collected within the SEO has identified the presence of microorganisms potentially involved in hydrogen, methane, and methanol oxidation (such as Hydrogenophaga, Methylobacterium, and Methylibium spp., respectively, as well as the presence of methanogenic Archaea (such as Methanobacterium. Similar organisms have also been documented at other serpentinizing sites, however their functions have not been confirmed. SEO's hyperalkaline springs have elevated methane concentrations, ranging from 145 to 900 μM, in comparison to the background concentrations (<0.3 μM. The presence and potential activity of microorganisms involved in methane cycling in serpentinization-influenced fluids from different sites within the SEO were investigated using molecular, geochemical, and modeling approaches. These results were combined to elucidate the bioenergetically favorable methane production and/or oxidation reactions in this tropical serpentinizing environment. The hyperalkaline springs at SEO contain a greater proportion of Archaea and methanogens than has been detected in any terrestrial serpentinizing system. Archaea involved in methanogenesis and anaerobic methane oxidation accounted from 40 to 90% of total

Parenting Environment and Scholastic Achievement during Adolescence: A Retrospective Study.

Science.gov (United States)

Taris, Toon W.; Bok, Inge A.

1996-01-01

This study examined the effects of perceived parenting style (overly protective versus a warm and loving environment) on the scholastic achievement of 986 Dutch adults age 18-30 years. Retrospective and longitudinal data suggested that respondents with overprotective parents drop out more frequently and have a lower level of educational attainment…

The geology, botany and chemistry of selected peat-forming environments from temperate and tropical latitudes

Science.gov (United States)

Cameron, C.C.; Esterle, J.S.; Palmer, C.A.

1989-01-01

Peat has been studied in several geologic settings: (1) glaciated terrain in cold temperate Maine and Minnesota, U.S.A.; (2) an island in the Atlantic Ocean off the coast of Maine, where sea level is rising; (3) the warm temperate U.S. Atlantic and Gulf Coastal Plains, where sea level has changed often; and (4) the tropical coast of Sarawak, Malaysia, and the tropical delta of the Batang Hari River, Sumatra, Indonesia. Most of these deposits are domed (ombrotrophic or partly ombrotrophic) bogs in which peat accumulation continued above the surface of the surrounding soil. However, the bogs of the U.S. Atlantic and Gulf Coastal Plains are comparatively not as domed, and many have almost level surfaces. In some bogs, aquatic or semi-aquatic plant materials accumulated, replaced water in the depressions, and formed a surface on which marsh or swamp vegetation could subsequently live, die, and accumulate. In others, the plant materials accumulated initially on level silt or sand surfaces supporting marshes or swamps. As the peat dome formed, plants growing on it changed from luxuriant ones near the base of the dome, where nutrients were brought into the bog by surface and ground water, to stunted ones at the top of the dome, where the raised bogs are fed by nutrient-poor precipitation. The physical and chemical changes that take place in the sequence of environments from the pond stage of deposit development, through the grassy marsh stage, through the forested swamp stage, and finally through the heath dome stage can be measured in terms of acidity and ash, volatile matter, carbon, hydrogen, nitrogen, sulfur and oxygen contents, as well as in the kind and distribution of trace elements. The organic and inorganic contents of the deposits relate to geomorphology, and geomorphology relates to their settings. As models of coal formation, some domed peat deposits may help in solving problems of distribution and character of ancient coal beds. But clearly not all peat

Is the poleward migration of tropical cyclone maximum intensity associated with a poleward migration of tropical cyclone genesis?

Science.gov (United States)

Daloz, Anne Sophie; Camargo, Suzana J.

2018-01-01

A recent study showed that the global average latitude where tropical cyclones achieve their lifetime-maximum intensity has been migrating poleward at a rate of about one-half degree of latitude per decade over the last 30 years in each hemisphere. However, it does not answer a critical question: is the poleward migration of tropical cyclone lifetime-maximum intensity associated with a poleward migration of tropical cyclone genesis? In this study we will examine this question. First we analyze changes in the environmental variables associated with tropical cyclone genesis, namely entropy deficit, potential intensity, vertical wind shear, vorticity, skin temperature and specific humidity at 500 hPa in reanalysis datasets between 1980 and 2013. Then, a selection of these variables is combined into two tropical cyclone genesis indices that empirically relate tropical cyclone genesis to large-scale variables. We find a shift toward greater (smaller) average potential number of genesis at higher (lower) latitudes over most regions of the Pacific Ocean, which is consistent with a migration of tropical cyclone genesis towards higher latitudes. We then examine the global best track archive and find coherent and significant poleward shifts in mean genesis position over the Pacific Ocean basins.

Internet Self-Efficacy Preferences of Internet Based Environments and Achievement of Prospective Teachers

Science.gov (United States)

Ozyalcin Oskay, Ozge

2011-01-01

The aims of this study are to determine prospective chemistry teachers' internet self-efficacy and preferences of constructivist internet-assisted environments and to examine the relationship between their internet self-efficacy and their preferences for constructivist internet-assisted environments, the relationship between their achievement in…

Monitoring coastal wetlands in a highly dynamic tropical environment

International Nuclear Information System (INIS)

Saynor, M.J.; Finlayson, C.M.; Spiers, A.; Eliot, I.

2001-01-01

The Alligator Rivers Region in the wet-dry tropics of northern Australia has been selected by government and collaborating agencies as a key study area for the monitoring of natural and human-induced coastal change. The Region contains the floodplain wetlands of Kakadu National Park which have been recognised internationally for their natural and cultural heritage value. A coastal monitoring program for assessing and monitoring environmental change in the Alligator Rivers Region has been established at the Environmental Research Institute of the Supervising Scientist. This program has developed a regional capacity to measure and assess change on the wetlands, floodplains and coastline within the region. Field assessment and monitoring procedures have been developed for the program. The assessment procedures require use of georeferencing and data handling techniques to facilitate comparison and relational overlay of a wide variety of information. Monitoring includes regular survey of biophysical and cultural processes on the floodplains; such as the extension of tidal creeks and mangroves, shoreline movement, dieback in Melaleuca wetlands, and weed invasion of freshwater wetlands. A differential Global Positioning System is used to accurately georeference spatial data and a Geographic Information System is then used to store and assess information. The assessment and monitoring procedures can be applied to the wet-dry tropics in general. These studies are all particularly pertinent with the possibility of greenhouse gases causing global warming and potential sea-level rise, a major possible threat to the valued wetlands of Kakadu National Park, and across the wet-dry tropics in general

Career Aspirations of Adolescent Girls: Effects of Achievement Level, Grade, and Single-Sex School Environment.

Science.gov (United States)

Watson, Cary M.; Quatman, Teri; Edler, Erik

2002-01-01

Compared high achieving adolescent girls' ideal and real career aspirations to adolescent boys' aspirations, examining the influence of grade level, achievement level, and an all-girls school environment. At all achievement levels, girls were commensurate with boys in ideal and realistic career aspirations. High achieving girls exceeded the…

Single-sex versus coeducational environment and achievement in adolescent females.

Science.gov (United States)

Monaco, N M; Gaier, E L

1992-01-01

For women, the nature and range of experiences during the high school years take on special significance, since it is during this period that they usually weigh their various roles and adjust their levels of aspirations accordingly. If the high school environment is successful in reducing the discrepancy between what are often viewed as conflicting roles, adolescent females may place greater emphasis on achievement. It is within this context that the present paper explored the differential benefits of single-sex and coeducational schooling. The issue explored is not whether one is preferable for females; rather, the concern here is how each of these settings influences both achievement and personal fulfillment.

The Upshear Environment-Outflow Interface of a Sheared, Rapidly Intensifying Tropical Cyclone

Science.gov (United States)

Ryglicki, D.; Doyle, J. D.; Jin, Y.; Hodyss, D.; Viner, K.

2017-12-01

An idealized, simulated tropical cyclone (TC) which undergoes rapid intensification in moderate vertical wind shear is shown to exhibit structural similarities to observed TCs of this class. Due to a complex vortex tilt evolution, enhanced convection causes enhanced outflow from the TC which subsequently serves to block and to divert environmental flow around the TC. This allows for the TC to come back into vertical alignment and undergo rapid intensification. A trajectory analysis indicates that blocking is limited to a narrow range of heights, indicating that the vertical profile of environmental winds is a key factor for permitting this evolution. Satellite observations indicate the presence of upper-level arcs extending upshear beyond the TC. Synthetic satellite imagery of the simulated TC indicates this is the termination of the outflow. Using a Helmholtz decomposition, it is found that the divergent component of the outflow extends 1000 km upshear into the environment, potentially explaining the 1000-km clearing seen in satellite observations.

Maize, tropical (Zea mays L.).

Science.gov (United States)

Assem, Shireen K

2015-01-01

Maize (Zea mays L.) is the third most important food crop globally after wheat and rice. In sub-Saharan Africa, tropical maize has traditionally been the main staple of the diet; 95 % of the maize grown is consumed directly as human food and as an important source of income for the resource-poor rural population. The biotechnological approach to engineer biotic and abiotic traits implies the availability of an efficient plant transformation method. The production of genetically transformed plants depends both on the ability to integrate foreign genes into target cells and the efficiency with which plants are regenerated. Maize transformation and regeneration through immature embryo culture is the most efficient system to regenerate normal transgenic plants. However, this system is highly genotype dependent. Genotypes adapted to tropic areas are difficult to regenerate. Therefore, transformation methods used with model genotypes adapted to temperate areas are not necessarily efficient with tropical lines. Agrobacterium-mediated transformation is the method of choice since it has been first achieved in 1996. In this report, we describe a transformation method used successfully with several tropical maize lines. All the steps of transformation and regeneration are described in details. This protocol can be used with a wide variety of tropical lines. However, some modifications may be needed with recalcitrant lines.

The Family Environment and Achievement of Deaf Students: A Discriminant Analysis.

Science.gov (United States)

Bodner-Johnson, Barbara

1986-01-01

Parental responses (N=125) to scaled items in home interviews were factor analyzed and family environment dimensions were employed as predictor variables. Parents of proficient readers were characterized as adapted to their children's deafness, involved in the deaf community, and permissive rather than overprotective. High achievers had parents…

Effects of using phenotypic means and genotypic values in GGE biplot analyses on genotype by environment studies on tropical maize (Zea mays).

Science.gov (United States)

Granato, I S C; Fritsche-Neto, R; Resende, M D V; Silva, F F

2016-10-05

The objective of this study was to examine the effects of the type and intensity of nutritional stress, and of the statistical treatment of the data, on the genotype x environment (G x E) interaction for tropical maize (Zea mays). For this purpose, 39 hybrid combinations were evaluated under low- and high-nitrogen and -phosphorus availability. The plants were harvested at the V6 stage, and the shoot dry mass was estimated. The variance components and genetic values were assessed using the restricted maximum likelihood/best linear unbiased prediction method, and subsequently analyzed using the GGE biplot method. We observed differences in the performances of the hybrids depending on both the type and intensity of nutritional stress. The results of relationship between environments depended on whether genotypic values or phenotypic means were used. The selection of tropical maize genotypes against nutritional stress should be performed for each nutrient availability level within each type of nutritional stress. The use of phenotypic means for this purpose provides greater reliability than do genotypic values for the analysis of the G x E interaction using GGE biplot.

Multi-Temporal Interferometry to Investigate Landslide Dynamics in a Tropical Urban Environment: Focus on Bukavu (DR Congo)

Science.gov (United States)

Monsieurs, E.; Dille, A.; Nobile, A.; d'Oreye, N.; Kervyn, F.; Dewitte, O.

2017-12-01

Landslides can lead to high impacts in less developed countries, particularly in some urban tropical environments where a combination of intense rainfall, active tectonics, steep topography and high population density can be found. However, the processes controlling landslides initiation and their evolution through time remains poorly understood. Here we show the relevance of the use of multi-temporal differential SAR interferometry (DInSAR) to characterize ground deformations associated to landslides in the rapidly expanding city of Bukavu (DR Congo). A series of 70 COSMO-SkyMed SAR images acquired between March 2015 and April 2016 with a mean revisiting time of 8 days were used to produce displacement rate maps and ground deformation time series using the Small Baseline Subset approach. Results show that various landslide processes of different ages, mechanisms and state of activity can be identified across Bukavu city. InSAR ground deformation maps reveal for instance the complexity of a large (1.5 km²) active slide affecting a densely inhabited slum neighbourhood and characterized by the presence of sectors moving at different rates (ranging from 10 mm/yr up to 75 mm/yr in LOS direction). The evaluation of the ground deformations captured by DInSAR through a two-step validation procedure combining Differential GPS measurements and field observations attested the reliability of the measurements as well as the capability of the technique to grasp the deformation pattern affecting this complex tropical-urban environment. However, longer time series will be needed to infer landside response to climate, seismic and anthropogenic activities.

Interactions between sire family and production environment (temperate vs. tropical) on performance and thermoregulation responses in growing pigs.

Science.gov (United States)

Rosé, R; Gilbert, H; Loyau, T; Giorgi, M; Billon, Y; Riquet, J; Renaudeau, D; Gourdine, J-L

2017-11-01

The aim of this study was to evaluate the effect of 2 climatic environments (temperate [TEMP] vs. tropical humid [TROP]) on production and thermoregulation traits in growing pigs. A backcross design involving Large White (LW; heat sensitive) and Creole (CR; heat tolerant) pigs was studied. The same 10 F LW × CR boars were mated with related LW sows in each environment. A total of 1,298 backcross pigs ( = 634 pigs from 11 batches for the TEMP environment and = 664 pigs from 12 batches for the TROP environment) were phenotyped on BW (every 15 d from wk 11 to 23 of age), voluntary feed intake (ADFI, from wk 11 to 23), backfat thickness (BFT; at wk 19 and 23), skin temperature (ST; at wk 19 and 23), and rectal temperature (RT; at wk 19, 21, and 23). The feed conversion ratio was computed for the whole test period (11 to 23 wk). The calculation of the temperature-humidity index showed an average difference of 2.4°C between the TEMP and TROP environments. The ADG and ADFI were higher in the TEMP environment than in the TROP environment (834 vs. 754 g/d and 2.20 vs. 1.80 kg/d, respectively; environment than in the TEMP environment (35.9 vs. 34.8°C for ST and 39.5 vs. 39.3°C for RT, respectively; environment interactions ( environment interaction and to detect QTL related to heat tolerance.

Evaluation of Service Life of Polystyrene in Tropical Marine Environment by Principal Component Analysis

Directory of Open Access Journals (Sweden)

Dongdong Song

2015-01-01

Full Text Available To predict the service life of polystyrene (PS under an aggressive environment, the nondimensional expression Z was established from a data set of multiple properties of PS by principal component analysis (PCA. In this study, PS specimens were exposed to the tropical environment on Xisha Islands in China for two years. Chromatic aberration, gloss, tensile strength, elongation at break, flexural strength, and impact strength were tested to evaluate the aging behavior of PS. Based on different needs of industries, each of the multiple properties could be used to evaluate the service life of PS. However, selecting a single performance variation will inevitably hide some information about the entire aging process. Therefore, finding a comprehensive measure representing the overall aging performance of PS can be highly significant. Herein, PCA was applied to obtain a specific property (Z which can represent all properties of PS. Z of PS degradation showed a slight decrease for the initial two months of exposure after which it increased rapidly in the next eight months. Subsequently, a slower increase of Z value was observed. From the three different stages shown as Z value increases, three stages have been identified for PS service life.

Ideal proportion of roughage and concentrate for Malpura ewes to adapt and reproduce in a semi-arid tropical environment.

Science.gov (United States)

Indu, Shekhawat; Sejian, Veerasamy; Kumar, Davendra; Pareek, Arvind; Naqvi, Syed Mohammad Krusheed

2015-12-01

The study was designed to identify the most appropriate roughage to concentrate ratio for Malpura ewes under semi-arid tropical environments. The study was conducted for a period of 35 days and included 30 (2 years old) non-pregnant Malpura ewes weighing between 30 and 35 kg. Estrus synchronization was carried out in all the animals using indigenously developed intravaginal sponges impregnated with progesterone. The ewes were randomly divided into three groups (n = 10/group) namely R50 (n = 10; roughage to concentrate, 50:50), R60 (n = 10; roughage to concentrate, 60:40), and R70 (n = 10; roughage to concentrate, 70:30). Individual feed and water intake was recorded on a daily basis throughout the course of the study. Growth variables, physiological responses, blood metabolites, and endocrine responses were estimated at weekly intervals. Results of the study indicated that nutritional treatment significantly influenced growth variables including body weight (p progesterone, PCV, total cholesterol, total protein, albumin, estrus%, and estrus cycle length. Since the additional concentrate supplementation in R50 and R60 did not improve the production variables, it can be concluded that providing 70 % roughage and 30 % concentrate could be a more appropriate and economically feasible ration composition for Malpura ewes reared in semi-arid tropical environments.

Temporal Patterns in Seawater Quality from Dredging in Tropical Environments.

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Ross Jones

Full Text Available Maintenance and capital dredging represents a potential risk to tropical environments, especially in turbidity-sensitive environments such as coral reefs. There is little detailed, published observational time-series data that quantifies how dredging affects seawater quality conditions temporally and spatially. This information is needed to test realistic exposure scenarios to better understand the seawater-quality implications of dredging and ultimately to better predict and manage impacts of future projects. Using data from three recent major capital dredging programs in North Western Australia, the extent and duration of natural (baseline and dredging-related turbidity events are described over periods ranging from hours to weeks. Very close to dredging i.e. <500 m distance, a characteristic features of these particular case studies was high temporal variability. Over several hours suspended sediment concentrations (SSCs can range from 100-500 mg L-1. Less turbid conditions (10-80 mg L-1 can persist over several days but over longer periods (weeks to months averages were <10 mg L-1. During turbidity events all benthic light was sometimes extinguished, even in the shallow reefal environment, however a much more common feature was very low light 'caliginous' or daytime twilight periods. Compared to pre-dredging conditions, dredging increased the intensity, duration and frequency of the turbidity events by 10-, 5- and 3-fold respectively (at sites <500 m from dredging. However, when averaged across the entire dredging period of 80-180 weeks, turbidity values only increased by 2-3 fold above pre-dredging levels. Similarly, the upper percentile values (e.g., P99, P95 of seawater quality parameters can be highly elevated over short periods, but converge to values only marginally above baseline states over longer periods. Dredging in these studies altered the overall probability density distribution, increasing the frequency of extreme values. As

Comprehensive overview of FPL field testing conducted in the tropics (1945-2005)

Science.gov (United States)

Grant T. Kirker; Stan L. Lebow; Mark E. Mankowski

2016-01-01

Tropical exposure often represents a more severe environment for treated wood and wood based products. Accelerated tropical decay rates are typically attributed to higher mean rainfall and temperatures. The Forest Products Laboratory (FPL) in Madison, WI has been conducting tropical field tests in a variety of locations since the early 1940’s. This paper summarizes FPL...

Nitrogenous nutrients and primary production in a tropical oceanic environment

Digital Repository Service at National Institute of Oceanography (India)

Wafar, M.V.M.; Wafar, S.; Devassy, V.P.

Measurements of the concentrations of nitrogenous nutrients and primary production were made at 10 stations along 8 degrees N and 10 degrees N in the tropical oceanic Lakshadweep waters Inorganic nitrogen (NO3, NO2 and NH4) accounted for less than...

Personal Learning Environments (PLE) in the Academic Achievement of University Students

Science.gov (United States)

Gallego, Maria Jesus; Gamiz, Vanesa Maria

2014-01-01

The main purpose of this research is to analyze the elements that compose the PLE of pre-service teachers and to determine whether the composition of these environments is related to academic achievement in a course on Information and Communication Technologies in Education. The hypothesis is that a PLE with more components is related to a higher…

The future of reforestation programs in the tropical developing countries: insights from the Philippines

Science.gov (United States)

Mukul, S. A.; Herbohn, J. L.

2013-12-01

Reforestation against the rapid rate of deforestation and forest degradation is common in most tropical developing countries. The main objective of reforestation programs is to restore and/or enhance the degraded landscapes depreciated in environmental value. However due to changing socio-political contexts and increasing awareness on sustainable development and environmental issues such programs are becoming more challenging, particularly in the developing tropics. Like most tropical developing countries substantial deforestation has occurred in the Philippines followed by massive logging and slash-and-burn agriculture, resulting in severe social and environmental problems. The country is also one of the pioneer countries that introduces reforestation program to restore its degraded forests. Most recently the government of the Philippines has launched the National Greening Program (NGP), one of the largest reforestation projects so far, with an aim to reforest 1.5 million hectares of degraded forest in critical watersheds over a five year time period. This paper highlights the key challenges that might hinder the success of the reforestation program through National Greening Program. We found that it is unlikely to achieve the desired project goals if rural communities dependent on upland landscapes are excluded from the reforestation program through plantation establishment. Bringing larger amount of areas and greater number of people under community based forest management (CBFM) initiatives for reforestation programs, with clearly defined rights and responsibilities, as well as securing timely access to timber harvesting permits to the communities involved in maintaining the plantations could enhance the long term reforestation success in the country. The paper also tries to provide a critical review of the past reforestation efforts in the Philippines, and direction of possible research and development in order to achieve a win-win situation that will benefits

Diversity and carbon storage across the tropical forest biome

Science.gov (United States)

Sullivan, Martin J. P.; Talbot, Joey; Lewis, Simon L.; Phillips, Oliver L.; Qie, Lan; Begne, Serge K.; Chave, Jerôme; Cuni-Sanchez, Aida; Hubau, Wannes; Lopez-Gonzalez, Gabriela; Miles, Lera; Monteagudo-Mendoza, Abel; Sonké, Bonaventure; Sunderland, Terry; Ter Steege, Hans; White, Lee J. T.; Affum-Baffoe, Kofi; Aiba, Shin-Ichiro; de Almeida, Everton Cristo; de Oliveira, Edmar Almeida; Alvarez-Loayza, Patricia; Dávila, Esteban Álvarez; Andrade, Ana; Aragão, Luiz E. O. C.; Ashton, Peter; Aymard C., Gerardo A.; Baker, Timothy R.; Balinga, Michael; Banin, Lindsay F.; Baraloto, Christopher; Bastin, Jean-Francois; Berry, Nicholas; Bogaert, Jan; Bonal, Damien; Bongers, Frans; Brienen, Roel; Camargo, José Luís C.; Cerón, Carlos; Moscoso, Victor Chama; Chezeaux, Eric; Clark, Connie J.; Pacheco, Álvaro Cogollo; Comiskey, James A.; Valverde, Fernando Cornejo; Coronado, Eurídice N. Honorio; Dargie, Greta; Davies, Stuart J.; de Canniere, Charles; Djuikouo K., Marie Noel; Doucet, Jean-Louis; Erwin, Terry L.; Espejo, Javier Silva; Ewango, Corneille E. N.; Fauset, Sophie; Feldpausch, Ted R.; Herrera, Rafael; Gilpin, Martin; Gloor, Emanuel; Hall, Jefferson S.; Harris, David J.; Hart, Terese B.; Kartawinata, Kuswata; Kho, Lip Khoon; Kitayama, Kanehiro; Laurance, Susan G. W.; Laurance, William F.; Leal, Miguel E.; Lovejoy, Thomas; Lovett, Jon C.; Lukasu, Faustin Mpanya; Makana, Jean-Remy; Malhi, Yadvinder; Maracahipes, Leandro; Marimon, Beatriz S.; Junior, Ben Hur Marimon; Marshall, Andrew R.; Morandi, Paulo S.; Mukendi, John Tshibamba; Mukinzi, Jaques; Nilus, Reuben; Vargas, Percy Núñez; Camacho, Nadir C. Pallqui; Pardo, Guido; Peña-Claros, Marielos; Pétronelli, Pascal; Pickavance, Georgia C.; Poulsen, Axel Dalberg; Poulsen, John R.; Primack, Richard B.; Priyadi, Hari; Quesada, Carlos A.; Reitsma, Jan; Réjou-Méchain, Maxime; Restrepo, Zorayda; Rutishauser, Ervan; Salim, Kamariah Abu; Salomão, Rafael P.; Samsoedin, Ismayadi; Sheil, Douglas; Sierra, Rodrigo; Silveira, Marcos; Slik, J. W. Ferry; Steel, Lisa; Taedoumg, Hermann; Tan, Sylvester; Terborgh, John W.; Thomas, Sean C.; Toledo, Marisol; Umunay, Peter M.; Gamarra, Luis Valenzuela; Vieira, Ima Célia Guimarães; Vos, Vincent A.; Wang, Ophelia; Willcock, Simon; Zemagho, Lise

2017-01-01

Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these two functions depend critically on the tropical forest tree diversity-carbon storage relationship. Assessing this relationship is challenging due to the scarcity of inventories where carbon stocks in aboveground biomass and species identifications have been simultaneously and robustly quantified. Here, we compile a unique pan-tropical dataset of 360 plots located in structurally intact old-growth closed-canopy forest, surveyed using standardised methods, allowing a multi-scale evaluation of diversity-carbon relationships in tropical forests. Diversity-carbon relationships among all plots at 1 ha scale across the tropics are absent, and within continents are either weak (Asia) or absent (Amazonia, Africa). A weak positive relationship is detectable within 1 ha plots, indicating that diversity effects in tropical forests may be scale dependent. The absence of clear diversity-carbon relationships at scales relevant to conservation planning means that carbon-centred conservation strategies will inevitably miss many high diversity ecosystems. As tropical forests can have any combination of tree diversity and carbon stocks both require explicit consideration when optimising policies to manage tropical carbon and biodiversity.

Diversity and carbon storage across the tropical forest biome.

Science.gov (United States)

Sullivan, Martin J P; Talbot, Joey; Lewis, Simon L; Phillips, Oliver L; Qie, Lan; Begne, Serge K; Chave, Jerôme; Cuni-Sanchez, Aida; Hubau, Wannes; Lopez-Gonzalez, Gabriela; Miles, Lera; Monteagudo-Mendoza, Abel; Sonké, Bonaventure; Sunderland, Terry; Ter Steege, Hans; White, Lee J T; Affum-Baffoe, Kofi; Aiba, Shin-Ichiro; de Almeida, Everton Cristo; de Oliveira, Edmar Almeida; Alvarez-Loayza, Patricia; Dávila, Esteban Álvarez; Andrade, Ana; Aragão, Luiz E O C; Ashton, Peter; Aymard C, Gerardo A; Baker, Timothy R; Balinga, Michael; Banin, Lindsay F; Baraloto, Christopher; Bastin, Jean-Francois; Berry, Nicholas; Bogaert, Jan; Bonal, Damien; Bongers, Frans; Brienen, Roel; Camargo, José Luís C; Cerón, Carlos; Moscoso, Victor Chama; Chezeaux, Eric; Clark, Connie J; Pacheco, Álvaro Cogollo; Comiskey, James A; Valverde, Fernando Cornejo; Coronado, Eurídice N Honorio; Dargie, Greta; Davies, Stuart J; De Canniere, Charles; Djuikouo K, Marie Noel; Doucet, Jean-Louis; Erwin, Terry L; Espejo, Javier Silva; Ewango, Corneille E N; Fauset, Sophie; Feldpausch, Ted R; Herrera, Rafael; Gilpin, Martin; Gloor, Emanuel; Hall, Jefferson S; Harris, David J; Hart, Terese B; Kartawinata, Kuswata; Kho, Lip Khoon; Kitayama, Kanehiro; Laurance, Susan G W; Laurance, William F; Leal, Miguel E; Lovejoy, Thomas; Lovett, Jon C; Lukasu, Faustin Mpanya; Makana, Jean-Remy; Malhi, Yadvinder; Maracahipes, Leandro; Marimon, Beatriz S; Junior, Ben Hur Marimon; Marshall, Andrew R; Morandi, Paulo S; Mukendi, John Tshibamba; Mukinzi, Jaques; Nilus, Reuben; Vargas, Percy Núñez; Camacho, Nadir C Pallqui; Pardo, Guido; Peña-Claros, Marielos; Pétronelli, Pascal; Pickavance, Georgia C; Poulsen, Axel Dalberg; Poulsen, John R; Primack, Richard B; Priyadi, Hari; Quesada, Carlos A; Reitsma, Jan; Réjou-Méchain, Maxime; Restrepo, Zorayda; Rutishauser, Ervan; Salim, Kamariah Abu; Salomão, Rafael P; Samsoedin, Ismayadi; Sheil, Douglas; Sierra, Rodrigo; Silveira, Marcos; Slik, J W Ferry; Steel, Lisa; Taedoumg, Hermann; Tan, Sylvester; Terborgh, John W; Thomas, Sean C; Toledo, Marisol; Umunay, Peter M; Gamarra, Luis Valenzuela; Vieira, Ima Célia Guimarães; Vos, Vincent A; Wang, Ophelia; Willcock, Simon; Zemagho, Lise

2017-01-17

Tropical forests are global centres of biodiversity and carbon storage. Many tropical countries aspire to protect forest to fulfil biodiversity and climate mitigation policy targets, but the conservation strategies needed to achieve these two functions depend critically on the tropical forest tree diversity-carbon storage relationship. Assessing this relationship is challenging due to the scarcity of inventories where carbon stocks in aboveground biomass and species identifications have been simultaneously and robustly quantified. Here, we compile a unique pan-tropical dataset of 360 plots located in structurally intact old-growth closed-canopy forest, surveyed using standardised methods, allowing a multi-scale evaluation of diversity-carbon relationships in tropical forests. Diversity-carbon relationships among all plots at 1 ha scale across the tropics are absent, and within continents are either weak (Asia) or absent (Amazonia, Africa). A weak positive relationship is detectable within 1 ha plots, indicating that diversity effects in tropical forests may be scale dependent. The absence of clear diversity-carbon relationships at scales relevant to conservation planning means that carbon-centred conservation strategies will inevitably miss many high diversity ecosystems. As tropical forests can have any combination of tree diversity and carbon stocks both require explicit consideration when optimising policies to manage tropical carbon and biodiversity.

The transfer of radionuclides in the terrestrial environments. Recent research results in monsoon tropical condition of Vietnam

International Nuclear Information System (INIS)

Binh, Nguyen Thanh; Y, Truong; Sieu, Le Nhu; Ngo, Nguyen Trong; Phuc, Nguyen Van; Huong, Mai Thi; Quang, Nguyen Hao; Nhan, Dang Duc

2003-01-01

The data on Radionuclide transfer parameters in the environments, which are used in radioecological models, are very necessary for setting release limits of radioactive effluent and assessing the radiation dose to Man related to the releases of radionuclides from nuclear facilities. They strongly depend on climatic, geographic, environmental and pedological conditions. For temperate environments, they are abundant and have been established fairly well. Meanwhile the literature data are still scare and dispersal for Tropical and Sub-tropical zones. Besides, the improvement of Environmental Transfer Models and Parameters is an important problem so that they may be adapted for Southeast Asian countries including Japan as environmental conditions and foodstuffs in this Region are significantly different from those in Europe and North America. The paper presents measurements results of the dry deposition velocities of atmospheric aerosols carrying 7 Be, 137 Cs radionuclides and measurements results of soil to plant transfer factors (TF) for 60 Co, 65 Zn, 85 ASr and 134 Cs resulted from the out door radiotracer experiments with large pots. The selected soil types (Podzolic, Ferralitic, Ferralic Acrisols, Eutric Fluvisols and Orthi-thionic Fluvisols soil) and the plants (rice, black bean, cabbage, lettuce, tomato, cucumber, carrot, white radish, potato) used for the research are the most common in Vietnam. The measured Vg values (cm/s) are in the range of 0.01 - 1.84 for 7 Be and 1.95 - 49.77 for 137 Cs. An analysis of the associated meteorological parameters showed some correlations between 7 Be Vg with humidity and 137 Cs Vg with wind velocity. More than 400 TF (edible part) values were determined and their dependences on some soil parameters have been shown. (author)

Using software interoperability to achieve a virtual design environment

Science.gov (United States)

Gregory, G. Groot; Koshel, R. John

2005-09-01

A variety of simulation tools, including optical design and analysis, have benefited by many years of evolution in software functionality and computing power, thus making the notion of virtual design environments a reality. To simulate the optical characteristics of a system, one needs to include optical performance, mechanical design and manufacturing aspects simultaneously. To date, no single software program offers a universal solution. One approach to achieve an integrated environment is to select tools that offer a high degree of interoperability. This allows the selection of the best tools for each aspect of the design working in concert to solve the problem. This paper discusses the issues of how to assemble a design environment and provides an example of a combination of tools for illumination design. We begin by offering a broad definition of interoperability from an optical analysis perspective. This definition includes aspects of file interchange formats, software communications protocols and customized applications. One example solution is proposed by combining SolidWorks1 for computer-aided design (CAD), TracePro2 for optical analysis and MATLAB3 as the mathematical engine for tolerance analysis. The resulting virtual tool will be applied to a lightpipe design task to illustrate how such a system can be used.

Spatial Distributions of Tropical Cyclone Tornadoes by Intensity and Size Characteristics

Directory of Open Access Journals (Sweden)

Todd W. Moore

2017-08-01

Full Text Available Tropical cyclones that make landfall often spawn tornadoes. Previous studies have shown that these tornadoes are not uniformly distributed in the United States or in the tropical cyclone environment. They show that tornadoes tend to occur relatively close to the coastline and that they tend to cluster to the east-of-center in the tropical cyclone environment, particularly in the northeast and east-of-center quadrants. This study contributes to these studies by analyzing the spatial distributions of tropical cyclone tornadoes by intensity, path length, path width, and the damage potential index. The analyses confirm that most tornadoes occur relatively close to the coastline, but show that stronger tornadoes with larger paths are disproportionately common farther inland. They also confirm that the highest amount of activity is located within the northeast and east-of-center quadrants and show that the most potentially damaging tornadoes cluster in a sub region near the intersection of these two quadrants.

Disaggregating Tropical Disease Prevalence by Climatic and Vegetative Zones within Tropical West Africa.

Science.gov (United States)

Beckley, Carl S; Shaban, Salisu; Palmer, Guy H; Hudak, Andrew T; Noh, Susan M; Futse, James E

2016-01-01

. These findings support the utility of environmental data for understanding vector-borne disease epidemiology on a regional level within a tropical environment.

Disaggregating Tropical Disease Prevalence by Climatic and Vegetative Zones within Tropical West Africa.

Directory of Open Access Journals (Sweden)

Carl S Beckley

. bigemina prevalence. These findings support the utility of environmental data for understanding vector-borne disease epidemiology on a regional level within a tropical environment.

Studies on growth and age of bivalves from temperate and tropical estuarine ecosystems

Digital Repository Service at National Institute of Oceanography (India)

Parulekar, A.H.

Comparison of growth progression and age composition of Abra alba and Nuculana minuta from temperate estuarine ecosystem with Meretrix casta and Paphia malabarica from tropical estuarine environment, revealed that the annual growth rate in tropical...

Agricultural expansion and its impacts on tropical nature.

Science.gov (United States)

Laurance, William F; Sayer, Jeffrey; Cassman, Kenneth G

2014-02-01

The human population is projected to reach 11 billion this century, with the greatest increases in tropical developing nations. This growth, in concert with rising per-capita consumption, will require large increases in food and biofuel production. How will these megatrends affect tropical terrestrial and aquatic ecosystems and biodiversity? We foresee (i) major expansion and intensification of tropical agriculture, especially in Sub-Saharan Africa and South America; (ii) continuing rapid loss and alteration of tropical old-growth forests, woodlands, and semi-arid environments; (iii) a pivotal role for new roadways in determining the spatial extent of agriculture; and (iv) intensified conflicts between food production and nature conservation. Key priorities are to improve technologies and policies that promote more ecologically efficient food production while optimizing the allocation of lands to conservation and agriculture. Copyright © 2013 Elsevier Ltd. All rights reserved.

Learning Environments as Basis for Cognitive Achievements of Students in Basic Science Classrooms in Nigeria

Science.gov (United States)

Atomatofa, Rachel; Okoye, Nnamdi; Igwebuike, Thomas

2016-01-01

The nature of classroom learning environments created by teachers had been considered very important for learning to take place effectively. This study investigated the effect of creating constructivist and transmissive learning environments on achievements of science students of different ability levels. 243 students formed the entire study…

High-throughput biodiversity analysis: Rapid assessment of species richness and ecological interactions of Chrysomelidae (Coleoptera) in the tropics.

Science.gov (United States)

Gómez-Zurita, Jesús; Cardoso, Anabela; Coronado, Indiana; De la Cadena, Gissela; Jurado-Rivera, José A; Maes, Jean-Michel; Montelongo, Tinguaro; Nguyen, Dinh Thi; Papadopoulou, Anna

2016-01-01

Biodiversity assessment has been the focus of intense debate and conceptual and methodological advances in recent years. The cultural, academic and aesthetic impulses to recognise and catalogue the diversity in our surroundings, in this case of living objects, is furthermore propelled by the urgency of understanding that we may be responsible for a dramatic reduction of biodiversity, comparable in magnitude to geological mass extinctions. One of the most important advances in this attempt to characterise biodiversity has been incorporating DNA-based characters and molecular taxonomy tools to achieve faster and more efficient species delimitation and identification, even in hyperdiverse tropical biomes. In this assay we advocate for a broad understanding of Biodiversity as the inventory of species in a given environment, but also the diversity of their interactions, with both aspects being attainable using molecular markers and phylogenetic approaches. We exemplify the suitability and utility of this framework for large-scale biodiversity assessment with the results of our ongoing projects trying to characterise the communities of leaf beetles and their host plants in several tropical setups. Moreover, we propose that approaches similar to ours, establishing the inventories of two ecologically inter-related and species-rich groups of organisms, such as insect herbivores and their angiosperm host-plants, can serve as the foundational stone to anchor a comprehensive assessment of diversity, also in tropical environments, by subsequent addition of trophic levels.

Tropical forage legumes for environmental benefits: An overview

Directory of Open Access Journals (Sweden)

Rainer Schultze-Kraft

2018-01-01

Full Text Available Ruminant livestock production in the tropics, particularly when based on pastures, is frequently blamed for being detrimental to the environment, allegedly contributing to: (1 degradation and destruction of ecosystems, including degradation and loss of soil, water and biodiversity; and (2 climate change (global warming. In this paper we argue that, rather than being detrimental, tropical forage legumes can have a positive impact on the environment, mainly due to key attributes that characterize the Leguminosae (Fabaceae family: (1 symbiotic nitrogen fixation; (2 high nutritive value; (3 deep-reaching tap-root system; (4 wide taxonomic and genetic diversity; and (5 presence of particular secondary metabolites. Although there are also potential negative aspects, such as soil acidification and the risks of introduced legumes becoming invasive weeds, we submit that legumes have potential to contribute significantly to sustainable intensification of livestock production in the tropics, along with the provision of ecosystem services. To further assess, document and realize this potential, research for development needs in a range of areas are indicated.

An attempt to define the sodium requirements of lactating dairy cows in a tropical environment

NARCIS (Netherlands)

Thiangtum, W.; Yawongsa, A.; Schonewille, J.T.; Rukkwamsuk, T.; Yuangklang, C.; Verstegen, M.W.A.; Hendriks, W.H.

2011-01-01

BACKGROUND: Lactating dairy cattle in the tropics may require more sodium (Na) owing to the hot and humid climatic conditions. It is unknown whether the current recommendations on Na for lactating cows can be quantitatively used in tropical countries. This study attempted to define the Na

Tropical Cyclone Information System

Science.gov (United States)

Li, P. Peggy; Knosp, Brian W.; Vu, Quoc A.; Yi, Chao; Hristova-Veleva, Svetla M.

2009-01-01

The JPL Tropical Cyclone Infor ma tion System (TCIS) is a Web portal (http://tropicalcyclone.jpl.nasa.gov) that provides researchers with an extensive set of observed hurricane parameters together with large-scale and convection resolving model outputs. It provides a comprehensive set of high-resolution satellite (see figure), airborne, and in-situ observations in both image and data formats. Large-scale datasets depict the surrounding environmental parameters such as SST (Sea Surface Temperature) and aerosol loading. Model outputs and analysis tools are provided to evaluate model performance and compare observations from different platforms. The system pertains to the thermodynamic and microphysical structure of the storm, the air-sea interaction processes, and the larger-scale environment as depicted by ocean heat content and the aerosol loading of the environment. Currently, the TCIS is populated with satellite observations of all tropical cyclones observed globally during 2005. There is a plan to extend the database both forward in time till present as well as backward to 1998. The portal is powered by a MySQL database and an Apache/Tomcat Web server on a Linux system. The interactive graphic user interface is provided by Google Map.

Antibiotic resistant Pseudomonas spp. in the aquatic environment: A prevalence study under tropical and temperate climate conditions.

Science.gov (United States)

Devarajan, Naresh; Köhler, Thilo; Sivalingam, Periyasamy; van Delden, Christian; Mulaji, Crispin K; Mpiana, Pius T; Ibelings, Bastiaan W; Poté, John

2017-05-15

Microbial populations which are resistant to antibiotics are an emerging environmental concern with potentially serious implications for public health. Thus, there is a growing concern in exploring the occurrence of antibiotic resistance in the environment with no limitations to the factors that contribute to their emergence. The aquatic environment is considered to be a hot-spot for the acquisition and spread of antibiotic resistance due to pollution with emerging contaminants derived from anthropogenic activities. In this study, we report on the isolation and characterization of 141 Pseudomonas spp. from aquatic sediments receiving partially (un)treated hospital and communal effluents from three distinct geographical locations: Democratic Republic of the Congo (DRC), India (IN), and Switzerland (CH). P. putida (42%) and P. aeruginosa (39%) were the dominant Pseudomonas species. The highest frequency of antibiotic resistance against eight anti-pseudomonas agents was found among IN isolates (35-60%), followed by DRC (18-50%) and CH (12-54%). CTX-M was the most frequent β-lactamase found in CH (47% of isolates), while VIM-1 was dominant in isolates from DRC (61%) and IN (29%). NDM-1 was found in 29% of the total IN isolates and surprisingly also in 6% of CH isolates. Chromosomally-encoded efflux mechanisms were overexpressed in P. aeruginosa isolates from all three geographic locations. In vitro conjugative transfers of antibiotic resistance plasmids occurred more frequently under tropical temperatures (30 and 37 °C) than under temperate conditions (10 °C). The presence of Extended Spectrum β-lactamases (ESBLs) and Metallo β-lactamases (MBLs) in the isolates from environmental samples has important implications for humans who depend on public water supply and sanitation facilities. To our knowledge, this is the first study to demonstrate a comparison between treated/untreated effluents from urban and hospital settings as a source of microbial resistance

Impacts of tropical cyclones on Fiji and Samoa

Science.gov (United States)

Kuleshov, Yuriy; Prakash, Bipendra; Atalifo, Terry; Waqaicelua, Alipate; Seuseu, Sunny; Ausetalia Titimaea, Mulipola

2013-04-01

on Samoa totalled to US130 million. Cyclone Val caused damage and destruction to 95% of houses in Samoa and severe crop damage; total damage was estimated as US200 million. Recently, severe tropical cyclone Evan affected Samoa and Fiji (December 2012). Significant progress in operational tropical cyclone forecasting has been achieved over the past few decades which resulted in improving early warning system but death toll attributed to cyclones is still high - at least 14 deaths in Samoa are related to cyclone Evan (luckily, no death reports in Fiji). Cyclone-related economic losses also remain very high making significant negative impact on economies of the countries. Preliminary assessment of damage caused by cyclone Evan in Fiji indicates loses of about 75.29 million. By the end of this century projections suggest decreasing numbers of tropical cyclones but a possible shift towards more intense categories. In addition, geographic shifts in distribution of tropical cyclone occurrences caused by warming of the atmospheric and oceanic environment are possible. This should be taken in consideration by authorities of the Pacific Island Countries when developing adaptation strategies to increasing tropical cyclone risk due to climate change.

Determination of soil-to-plant transfer factors of {sup 137}Cs and {sup 90}Sr in the tropical environment of Bangladesh

Energy Technology Data Exchange (ETDEWEB)

Mollah, A.S.; Begum, A. [Atomic Energy Research Establishment (AERE), Savar, Dacca (Bangladesh); Ullah, S.M. [University of Dhaka (Bangladesh). Department of Soil Science

1998-07-01

Soil-to-plant transfer factors (TF) of {sup 137}Cs and {sup 90}Sr have been determined for different plants/crops, such as rice, beans, peanuts, pineapple, cabbage, tomato, spinach and grass. They were obtained from radioisotope experiments on plants grown in pots under outdoor ambient tropical conditions for three growing seasons (1994-1996). In the case of {sup 137}Cs and concerning the above mentioned plants/crops, the average TFs were found to be 0.28, 0.25, 0.77, 0.19, 0.23, 0.28, 0.59 and 0.18, respectively. In the case of {sup 90}Sr, the average TFs were found to be 0.82, 0.51, 0.20, 0.82, 0.69, 0.59, 0.91 and 0.84, respectively. A minor seasonal variation was observed. This study provides a database of TFs for tropical environments to be used, e.g., for radiological safety assessment models. (orig.) With 1 fig., 3 tabs., 12 refs.

Learning Environment, Attitudes and Achievement among Middle-School Science Students Using Inquiry-Based Laboratory Activities

Science.gov (United States)

Wolf, Stephen J.; Fraser, Barry J.

2008-01-01

This study compared inquiry and non-inquiry laboratory teaching in terms of students' perceptions of the classroom learning environment, attitudes toward science, and achievement among middle-school physical science students. Learning environment and attitude scales were found to be valid and related to each other for a sample of 1,434 students in…

The Socioeconomic Benefit to Individuals of Achieving the 2020 Targets for Five Preventive Chemotherapy Neglected Tropical Diseases.

Directory of Open Access Journals (Sweden)

William K Redekop

2017-01-01

Full Text Available Lymphatic filariasis (LF, onchocerciasis, schistosomiasis, soil-transmitted helminths (STH and trachoma represent the five most prevalent neglected tropical diseases (NTDs. They can be controlled or eliminated by means of safe and cost-effective interventions delivered through programs of Mass Drug Administration (MDA-also named Preventive Chemotherapy (PCT. The WHO defined targets for NTD control/elimination by 2020, reinforced by the 2012 London Declaration, which, if achieved, would result in dramatic health gains. We estimated the potential economic benefit of achieving these targets, focusing specifically on productivity and out-of-pocket payments.Productivity loss was calculated by combining disease frequency with productivity loss from the disease, from the perspective of affected individuals. Productivity gain was calculated by deducting the total loss expected in the target achievement scenario from the loss in a counterfactual scenario where it was assumed the pre-intervention situation in 1990 regarding NTDs would continue unabated until 2030. Economic benefits from out-of-pocket payments (OPPs were calculated similarly. Benefits are reported in 2005 US$ (purchasing power parity-adjusted and discounted at 3% per annum from 2010. Sensitivity analyses were used to assess the influence of changes in input parameters.The economic benefit from productivity gain was estimated to be I$251 billion in 2011-2020 and I$313 billion in 2021-2030, considerably greater than the total OPPs averted of I$0.72 billion and I$0.96 billion in the same periods. The net benefit is expected to be US$ 27.4 and US$ 42.8 for every dollar invested during the same periods. Impact varies between NTDs and regions, since it is determined by disease prevalence and extent of disease-related productivity loss.Achieving the PCT-NTD targets for 2020 will yield significant economic benefits to affected individuals. Despite large uncertainty, these benefits far exceed the

The Socioeconomic Benefit to Individuals of Achieving the 2020 Targets for Five Preventive Chemotherapy Neglected Tropical Diseases.

Science.gov (United States)

Redekop, William K; Lenk, Edeltraud J; Luyendijk, Marianne; Fitzpatrick, Christopher; Niessen, Louis; Stolk, Wilma A; Tediosi, Fabrizio; Rijnsburger, Adriana J; Bakker, Roel; Hontelez, Jan A C; Richardus, Jan H; Jacobson, Julie; de Vlas, Sake J; Severens, Johan L

2017-01-01

Lymphatic filariasis (LF), onchocerciasis, schistosomiasis, soil-transmitted helminths (STH) and trachoma represent the five most prevalent neglected tropical diseases (NTDs). They can be controlled or eliminated by means of safe and cost-effective interventions delivered through programs of Mass Drug Administration (MDA)-also named Preventive Chemotherapy (PCT). The WHO defined targets for NTD control/elimination by 2020, reinforced by the 2012 London Declaration, which, if achieved, would result in dramatic health gains. We estimated the potential economic benefit of achieving these targets, focusing specifically on productivity and out-of-pocket payments. Productivity loss was calculated by combining disease frequency with productivity loss from the disease, from the perspective of affected individuals. Productivity gain was calculated by deducting the total loss expected in the target achievement scenario from the loss in a counterfactual scenario where it was assumed the pre-intervention situation in 1990 regarding NTDs would continue unabated until 2030. Economic benefits from out-of-pocket payments (OPPs) were calculated similarly. Benefits are reported in 2005 US$ (purchasing power parity-adjusted and discounted at 3% per annum from 2010). Sensitivity analyses were used to assess the influence of changes in input parameters. The economic benefit from productivity gain was estimated to be I$251 billion in 2011-2020 and I$313 billion in 2021-2030, considerably greater than the total OPPs averted of I$0.72 billion and I$0.96 billion in the same periods. The net benefit is expected to be US$ 27.4 and US$ 42.8 for every dollar invested during the same periods. Impact varies between NTDs and regions, since it is determined by disease prevalence and extent of disease-related productivity loss. Achieving the PCT-NTD targets for 2020 will yield significant economic benefits to affected individuals. Despite large uncertainty, these benefits far exceed the investment

The family environment predicts long-term academic achievement and classroom behavior following traumatic brain injury in early childhood.

Science.gov (United States)

Durber, Chelsea M; Yeates, Keith Owen; Taylor, H Gerry; Walz, Nicolay Chertkoff; Stancin, Terry; Wade, Shari L

2017-07-01

This study examined how the family environment predicts long-term academic and behavioral functioning in school following traumatic brain injury (TBI) in early childhood. Using a concurrent cohort, prospective design, 15 children with severe TBI, 39 with moderate TBI, and 70 with orthopedic injury (OI) who were injured when they were 3-7 years of age were compared on tests of academic achievement and parent and teacher ratings of school performance and behavior on average 6.83 years postinjury. Soon after injury and at the longer term follow-up, families completed measures of parental psychological distress, family functioning, and quality of the home environment. Hierarchical linear regression analyses examined group differences in academic outcomes and their associations with measures of the early and later family environment. The severe TBI group, but not the moderate TBI group, performed worse than did the OI group on all achievement tests, parent ratings of academic performance, and teacher ratings of internalizing problems. Higher quality early and late home environments predicted stronger academic skills and better classroom behavior for children with both TBI and OI. The early family environment more consistently predicted academic achievement, whereas the later family environment more consistently predicted classroom functioning. The quality of the home environment predicted academic outcomes more strongly than did parental psychological distress or family functioning. TBI in early childhood has long-term consequences for academic achievement and school performance and behavior. Higher quality early and later home environments predict better school outcomes for both children with TBI and children with OI. (PsycINFO Database Record (c) 2017 APA, all rights reserved).

Can carbon emissions from tropical deforestation drop by 50% in 5 years?

Science.gov (United States)

Zarin, Daniel J; Harris, Nancy L; Baccini, Alessandro; Aksenov, Dmitry; Hansen, Matthew C; Azevedo-Ramos, Claudia; Azevedo, Tasso; Margono, Belinda A; Alencar, Ane C; Gabris, Chris; Allegretti, Adrienne; Potapov, Peter; Farina, Mary; Walker, Wayne S; Shevade, Varada S; Loboda, Tatiana V; Turubanova, Svetlana; Tyukavina, Alexandra

2016-04-01

Halving carbon emissions from tropical deforestation by 2020 could help bring the international community closer to the agreed goal of deforestation at 2.270 Gt CO2 yr(-1). Brazil did not sign the NYDF, yet from 2001 to 2013, Brazil ranks first for both carbon emissions from gross tropical deforestation and reductions in those emissions - its share of the total declined from a peak of 69% in 2003 to a low of 20% in 2012. Indonesia, an NYDF signatory, is the second highest emitter, peaking in 2012 at 0.362 Gt CO2 yr(-1) before declining to 0.205 Gt CO2 yr(-1) in 2013. The other 14 NYDF tropical country signatories were responsible for a combined average of 0.317 Gt CO2 yr(-1) , while the other 86 tropical country non-signatories were responsible for a combined average of 0.688 Gt CO2 yr(-1). We outline two scenarios for achieving the 50% emission reduction target by 2020, both emphasizing the critical role of Brazil and the need to reverse the trends of increasing carbon emissions from gross tropical deforestation in many other tropical countries that, from 2001 to 2013, have largely offset Brazil's reductions. Achieving the target will therefore be challenging, even though it is in the self-interest of the international community. Conserving rather than cutting down tropical forests requires shifting economic development away from a dependence on natural resource depletion toward recognition of the dependence of human societies on the natural capital that tropical forests represent and the goods and services they provide. © 2015 The Authors. Global Change Biology Published by John Wiley & Sons Ltd.

Environment and Development

International Nuclear Information System (INIS)

Wandiga, S.O.; Abuodha, N.L.; Abuodha, N.L.; Beigutt, K.S.A.

1996-01-01

It contains research papers presented at Kenya Academy of Sciecnes on the theme 'Envoronment and Development' whose objectives are: to highlight levels of achievement and endeavour in scientific research in environment, it's management and related areas, provide a forum debate and exchange of ideas between researchers, policy makers, and the general public on environmental issues and their effect on society, identify gaps in environmental knowledge as a basis for further research. The following titles of the following papers summarizes the details of the presentations; Kenya Eco-systems and global climate change, Integrated Coastal Zone Management related to the Kenyan Coast, Global Climate Change:Implications of the low lying area coastal parts of Kenya, Organochlorine Pesticides:Curse or blessings of the Tropical Environment, Environmental Degradation and Health in Kenya, Urban Environment and City Health Crisis in Kenya: The planning and Resource Allocation Question, Women and Food Security, Food Production and Village based Food Processing Industries of selected plants, Impact of Earthquakes, volcanic Eruptions on the Environment and Human Induced Climate Changes,Myth or reality and The Practice and Principles in Environmental Law for Kenya. this an 'Analytic' record describing research paper presented at the proceedings and published on page 157-168

Tropical Glaciers

Science.gov (United States)

Fountain, Andrew

The term "tropical glacier" calls to mind balmy nights and palm trees on one hand and cold, blue ice on the other. Certainly author Gabriel Garcia Marqez exploited this contrast in One Hundred Years of Solitude. We know that tropical fish live in warm, Sun-kissed waters and tropical plants provide lush, dense foliage populated by colorful tropical birds. So how do tropical glaciers fit into this scene? Like glaciers everywhere, tropical glaciers form where mass accumulation—usually winter snow—exceeds mass loss, which is generally summer melt. Thus, tropical glaciers exist at high elevations where precipitation can occur as snowfall exceeds melt and sublimation losses, such as the Rwenzori Mountains in east Africa and the Maoke Range of Irian Jaya.

Rapid Cycling Genomic Selection in a Multiparental Tropical Maize Population.

Science.gov (United States)

Zhang, Xuecai; Pérez-Rodríguez, Paulino; Burgueño, Juan; Olsen, Michael; Buckler, Edward; Atlin, Gary; Prasanna, Boddupalli M; Vargas, Mateo; San Vicente, Félix; Crossa, José

2017-07-05

Genomic selection (GS) increases genetic gain by reducing the length of the selection cycle, as has been exemplified in maize using rapid cycling recombination of biparental populations. However, no results of GS applied to maize multi-parental populations have been reported so far. This study is the first to show realized genetic gains of rapid cycling genomic selection (RCGS) for four recombination cycles in a multi-parental tropical maize population. Eighteen elite tropical maize lines were intercrossed twice, and self-pollinated once, to form the cycle 0 (C 0 ) training population. A total of 1000 ear-to-row C 0 families was genotyped with 955,690 genotyping-by-sequencing SNP markers; their testcrosses were phenotyped at four optimal locations in Mexico to form the training population. Individuals from families with the best plant types, maturity, and grain yield were selected and intermated to form RCGS cycle 1 (C 1 ). Predictions of the genotyped individuals forming cycle C 1 were made, and the best predicted grain yielders were selected as parents of C 2 ; this was repeated for more cycles (C 2 , C 3 , and C 4 ), thereby achieving two cycles per year. Multi-environment trials of individuals from populations C 0, C 1 , C 2 , C 3 , and C 4 , together with four benchmark checks were evaluated at two locations in Mexico. Results indicated that realized grain yield from C 1 to C 4 reached 0.225 ton ha -1 per cycle, which is equivalent to 0.100 ton ha -1  yr -1 over a 4.5-yr breeding period from the initial cross to the last cycle. Compared with the original 18 parents used to form cycle 0 (C 0 ), genetic diversity narrowed only slightly during the last GS cycles (C 3 and C 4 ). Results indicate that, in tropical maize multi-parental breeding populations, RCGS can be an effective breeding strategy for simultaneously conserving genetic diversity and achieving high genetic gains in a short period of time. Copyright © 2017 Zhang et al.

Genotype-environment interaction of maternal influence characteristics in Nellore cattle bred in the Brazilian humid tropical regions by reaction norm

Directory of Open Access Journals (Sweden)

Jorge Luís Ferreira

2015-08-01

Full Text Available Reaction Norm (RN is the study of genotype-environment interaction (GxE that complies with alternative ways of genotypes within different environments. This study was carried out to verify GxE by a reaction norm model of weights at 120 (W120 and 210 (W210 days of age in Nellore cattle raised in the Humid Tropical Regions of Brazil. Environmental gradients were obtained by solutions of contemporary groups which were fitted as co-variables in the random regression model via reaction norms. Mean weight at 120 days of age was 127.97 kg, and environmental gradients ranged between -27 and +26 kg. Average was 185.60 kg at 210 days of age and gradients ranged from -54 to +55 kg. Scale changes in the breeding values and heritability estimates occurred along the gradients for the two weights; the genetic correlations between breeding value breeding values were also similar for both weights. These correlations were high between the close gradients, and low to even negative between extreme environments. Slopes representing the environmental sensitivity were high, with changes of scale and changes in classification of ten bulls with a great numbers of calves for the two traits. When regression slopes of the ten bulls with the highest breeding value breeding values were evaluated, these values were different in W120 from those in W210, perhaps due to the greater influence of maternal effect on W120. These results characterize the influence of GxE on the pre-weaning weights of animals in the humid tropical regions of Brazil. Due to this, it is possible to get greater precision on the predictions of the animals breeding values breeding value. A less biased selection and a greater genetic progress occurred.

Basal metabolism in tropical birds: Latitude, altitude, and the 'pace of life'

OpenAIRE

Londoño, GA; Chappell, MA; Castañeda, MDR; Jankowski, JE; Robinson, SK

2015-01-01

© 2014 The Authors. Life history varies across latitudes, with the 'pace of life' being 'slower' in tropical regions. Because life history is coupled to energy metabolism via allocation tradeoffs and links between performance capacity and energy use, low metabolic intensity is expected in tropical animals. Low metabolism has been reported for lowland tropical birds, but it is unclear if this is due to 'slow' life history or to a warm, stable environment. We measured basal metabolic rates (BMR...

Ecological restoration success is higher for natural regeneration than for active restoration in tropical forests

OpenAIRE

Crouzeilles, Renato; Ferreira, Mariana S.; Chazdon, Robin L.; Lindenmayer, David B.; Sansevero, Jerônimo B. B.; Monteiro, Lara; Iribarrem, Alvaro; Latawiec, Agnieszka E.; Strassburg, Bernardo B. N.

2017-01-01

Is active restoration the best approach to achieve ecological restoration success (the return to a reference condition, that is, old-growth forest) when compared to natural regeneration in tropical forests? Our meta-analysis of 133 studies demonstrated that natural regeneration surpasses active restoration in achieving tropical forest restoration success for all three biodiversity groups (plants, birds, and invertebrates) and five measures of vegetation structure (cover, density, litter, biom...

THE BLENDED LEARNING ENVIRONMENT ON THE FOREIGN LANGUAGE LEARNING PROCESS: A Balance for Motivation and Achievement

Directory of Open Access Journals (Sweden)

Bahar ISIGUZEL

2014-07-01

Full Text Available The purpose of this study is to determine the effects on motivation and success within the application of blended learning environments in the foreign language class. The research sample is formed by third grade students studying in the tourism and hotel management programs of the faculty for tourism and the faculty of economics and administrative sciences at the Nevsehir Hacı Bektas Veli University (Turkey in fall semester of the 2012-2013 academic year. The research group consists of 62 students and there of 35 students belong to the experimental group and the other 27 persons belong to the control group. While the experimental group was subject to 14 hours online and 6 hours traditional face to face learning, the control group was subject to only 6 hours traditional face to face learning. The research has been completed after a 10 week application. The data on the research have been collected with German course achievement tests via the German Language Learning Motivation Scale. The results reveal that the experimental group of students attending the German classes in blended learning environments has more success and higher motivation compared to the control group attending German language classes in the traditional learning environment. Even if the learners achieve certain success and motivation findings in the classroom and face to face environments performed along with teaching-learning activities mainly in control of the instructor, the success and motivation effect of the blended learning environment could not be achieved.

High-throughput biodiversity analysis: Rapid assessment of species richness and ecological interactions of Chrysomelidae (Coleoptera) in the tropics

Science.gov (United States)

Gómez-Zurita, Jesús; Cardoso, Anabela; Coronado, Indiana; De la Cadena, Gissela; Jurado-Rivera, José A.; Maes, Jean-Michel; Montelongo, Tinguaro; Nguyen, Dinh Thi; Papadopoulou, Anna

2016-01-01

Abstract Biodiversity assessment has been the focus of intense debate and conceptual and methodological advances in recent years. The cultural, academic and aesthetic impulses to recognise and catalogue the diversity in our surroundings, in this case of living objects, is furthermore propelled by the urgency of understanding that we may be responsible for a dramatic reduction of biodiversity, comparable in magnitude to geological mass extinctions. One of the most important advances in this attempt to characterise biodiversity has been incorporating DNA-based characters and molecular taxonomy tools to achieve faster and more efficient species delimitation and identification, even in hyperdiverse tropical biomes. In this assay we advocate for a broad understanding of Biodiversity as the inventory of species in a given environment, but also the diversity of their interactions, with both aspects being attainable using molecular markers and phylogenetic approaches. We exemplify the suitability and utility of this framework for large-scale biodiversity assessment with the results of our ongoing projects trying to characterise the communities of leaf beetles and their host plants in several tropical setups. Moreover, we propose that approaches similar to ours, establishing the inventories of two ecologically inter-related and species-rich groups of organisms, such as insect herbivores and their angiosperm host-plants, can serve as the foundational stone to anchor a comprehensive assessment of diversity, also in tropical environments, by subsequent addition of trophic levels. PMID:27408583

Complex carbon cycling processes and pathways in a tropical coastal marine environment (Saco do Mamangua, RJ - Brazil)

Science.gov (United States)

Giorgioni, M.; Jovane, L.; Millo, C.; Sawakuchi, H. O.; Bertassoli, D. J., Jr.; Gamba Romano, R.; Pellizari, V.; Castillo Franco, D.; Krusche, A. V.

2016-12-01

The Saco do Mamangua is a narrow and elongated gulf located along the southeastern coast of Brazil, in the state of Rio de Janeiro (RJ). It is surrounded by high relieves, which form a peculiar environment called riá, with little river input and limited water exchange with the Atlantic Ocean. These features make the Saco do Mamangua an ideal environment to study sedimentary carbon cycling under well-constrained boundary conditions in order to investigate if tropical coastal environments serve dominantly as potential carbon sinks or sources. In this work we integrate geochemical data from marine sediments and pore waters in the Saco do Mamangua with mapping of benthic microbial communities, in order to unravel the biogeochemical carbon cycling linked to the production of biogenic methane. Our results reveal that carbon cycling occurs in two parallel pathways. The Saco do Mamangua receives organic carbon both by surface runoff and by primary production in the water column. A large part of this organic carbon is buried within the sediment resulting in the production of biogenic methane, which gives rise to methane seepages at the sea floor. These methane seeps sustain methanotrophic microbial communities in the sediment pore water, but also escapes into the atmosphere by ebullition. Consequently, the sediments of Saco do Mamangua acts simultaneously as carbon sink and carbon source. Future work will allow us to accurately quantify the actual carbon fluxes and calculate the net carbon balance in the local environment.

Intelligent Buildings: Key to Achieving Total Sustainability in the Built Environment

Directory of Open Access Journals (Sweden)

Tulika Gadakari

2014-01-01

Full Text Available ‘Are intelligent buildings a pragmatic approach towards achieving a sustainable built environment?’ is the research question that this review article aims to answer. It has been argued that there is a serious need for intelligent buildings to be evaluated against the parameters of total sustainability (environmental, economic and social so as to help the agenda of living in a technologically advanced, healthy and comfortable world. This paper reviews existing theoretical concepts of intelligence and sustainability in the built environment, through an exploration of various scientific literature and U.S Green Building Council’s LEED (Leadership in Energy and Environmental Design databases. A systematic qualitative review approach has been employed to select an appropriate definition of sustainable development and use it as a theoretical framework to assess the technological impact of intelligent buildings on the environmental, economic and social front. Subsequently five case study buildings from around the world, which exemplify the use of intelligent technologies to achieve sustainable gains were chosen and analyzed to further validate the literature findings. Outputs from the study highlight the various benefits of intelligent buildings, which include decrease in energy and water consumption, operational costs, as well as increase in productivity and investments. Additionally the analysis of the case studies revealed that the use of intelligent building technologies has contributed significantly towards a higher sustainability rating on the LEED rating scale. Moreover, the comparison of the attributes of intelligent buildings and sustainable practices in buildings, illustrates the fact that there is a considerable overlap between the two and intelligence can aid sustainability in the built environment. Thus the research suggests that green technologies and intelligence in combination may be a pragmatic approach towards the sustainability

Gigantic Jets and the Tropical Paradigm: A Satellite Perspective

Science.gov (United States)

Lazarus, S. M.; Splitt, M. E.

2017-12-01

While not exclusively oceanic, gigantic jets (GJ) appear to have a preference for the tropical environment. In particular, a number of GJs have been observed in conjunction with tropical disturbances (i.e., weak tropical storms, depressions, and remnant lows). Given the remote aspect of TC convection and general lack of radar coverage, we explore this subset of events via analysis of their infrared and water vapor satellite presentations. The satellite perspective is relevant given that storm top mixing (dilution) of charge associated with storm-scale turbulence in this portion of the storm is thought to be connected to GJs. The thunderstorm overshoot, upper level divergence / outflow are examined in an effort to better understand the tropical paradigm. Specifically, an analysis of cloud top temperature, anvil expansion rates and asymmetries as well as placement of the GJ events with respect to the large (storm) scale circulation will be conducted.

Land use history, environment, and tree composition in a tropical forest

Science.gov (United States)

Jill Thompson; Nicholas Brokaw; Jess K. Zimmerman; Robert B. Waide; Edwin M. III Everham; D. Jean Lodge; Charlotte M. Taylor; Diana Garcia-Montiel; Marcheterre Fluet

2002-01-01

The effects of historical land use on tropical forest must be examined to understand present forest characteristics and to plan conservation strategies. We compared the effects of past land use, topography, soil type, and other environmental variables on tree species composition in a subtropical wet forest in the Luquillo Mountains, Puerto Rico. The study involved...

Genomic-based-breeding tools for tropical maize improvement.

Science.gov (United States)

Chakradhar, Thammineni; Hindu, Vemuri; Reddy, Palakolanu Sudhakar

2017-12-01

Maize has traditionally been the main staple diet in the Southern Asia and Sub-Saharan Africa and widely grown by millions of resource poor small scale farmers. Approximately, 35.4 million hectares are sown to tropical maize, constituting around 59% of the developing worlds. Tropical maize encounters tremendous challenges besides poor agro-climatic situations with average yields recorded <3 tones/hectare that is far less than the average of developed countries. On the contrary to poor yields, the demand for maize as food, feed, and fuel is continuously increasing in these regions. Heterosis breeding introduced in early 90 s improved maize yields significantly, but genetic gains is still a mirage, particularly for crop growing under marginal environments. Application of molecular markers has accelerated the pace of maize breeding to some extent. The availability of array of sequencing and genotyping technologies offers unrivalled service to improve precision in maize-breeding programs through modern approaches such as genomic selection, genome-wide association studies, bulk segregant analysis-based sequencing approaches, etc. Superior alleles underlying complex traits can easily be identified and introgressed efficiently using these sequence-based approaches. Integration of genomic tools and techniques with advanced genetic resources such as nested association mapping and backcross nested association mapping could certainly address the genetic issues in maize improvement programs in developing countries. Huge diversity in tropical maize and its inherent capacity for doubled haploid technology offers advantage to apply the next generation genomic tools for accelerating production in marginal environments of tropical and subtropical world. Precision in phenotyping is the key for success of any molecular-breeding approach. This article reviews genomic technologies and their application to improve agronomic traits in tropical maize breeding has been reviewed in

The new research centre of the Brazilian Petroleum Company in Rio de Janeiro, Brazil: The achievements in the thermal performance of air-conditioned buildings in the tropics

Energy Technology Data Exchange (ETDEWEB)

Brandao, Rafael; Marcondes, Monica Pereira; De Benedetto, Gisele S.; Goncalves, Joana Carla Soares; Duarte, Denise Helena Silva; Ramos, Jose Ovidio [Laboratorio de Conforto Ambiental e Eficiencia Energetica (LABAUT), Departamento de Tecnologia da Arquitetura (AUT), Faculdade de Arquitetura e Urbanismo, Universidade de Sao Paulo (FAUUSP), Sao Paulo, Brasil, Rua do Lago, 876, Cidade Universitaria, 05508-900 Sao Paulo, SP (Brazil)

2008-07-01

The study on the thermal performance of the air-conditioned buildings of the new research centre of the Brazilian Petroleum Company, in the tropical climate of Rio de Janeiro, was part of a bigger research and consultancy project involving environmental issues. The architectural design was the subject of a national competition in 2004, encompassing over 100,000 m{sup 2}. According to the design brief, out of the 10 buildings of the new research centre, 7 have to be either completely or partially air-conditioned, due to specific occupation requirements. The challenge for better thermal performance was related to systems' energy efficiency, to the introduction of natural ventilation and to the notion of adaptive comfort, which were verified with the support of thermal dynamic simulations. At the early stages of the assessments, the potential for natural ventilation in the working spaces considering the mixed-mode strategy achieved 30% of occupation hours. However, the development of the design project led to fully air-conditioned working spaces, due to users' references regarding the conventional culture of the office environment. Nevertheless, the overall architectural approach in accordance to the climatic conditions still showed a contribution to the buildings' energy efficiency. (author)

Multi-Scale Aspects of Tropical Cyclone Predictability

Science.gov (United States)

Doyle, J. D.; Moskaitis, J.; Black, P. G.; Hendricks, E. A.; Reinecke, A.; Amerault, C. M.

2014-12-01

The intensification of tropical cyclones (TCs) may be sensitive to aspects of large-scale forcing, as well as internal mesoscale dynamics. In this presentation, the degree to which tropical cyclone intensity and structure is sensitive to small perturbations to the basic properties of the synoptic-scale environment, as well as in the immediate vicinity of the storm, is explored using both adjoint- and ensemble-based approaches. In particular, we explore the relationship between tropical cyclone intensity changes and upper-level outflow. We make use of observations from two recent field campaigns: i) the NASA Hurricane and Severe Storms Sentinel (HS3), which featured two fully instrumented Global Hawk unmanned aerial systems, and ii) the ONR Tropical Cyclone Intensity (TCI-14) experiment that utilized the NASA WB-57. We make use of the Navy's high-resolution tropical cyclone prediction system COAMPS-TC to provide ensemble forecasts, numerical experiments with and without the assimilation of specific observation types (e.g., satellite, dropsondes, high-frequency radiosonde), as well as mesoscale nested adjoint sensitivity and observation impact calculations, all of which provide insight into the initial state sensitivity and predictability issues. We assess the impact of observations in sensitive regions in the TC environment (including outflow regions away from the TC inner core) on predictions of TC intensity and structure. Overall the results underscore the importance of multiple scales that influence the predictability of TC intensification. During HS3, the assimilation of Global Hawk dropsondes has been shown to reduce the maximum wind error from 15 knots to less than 10 knots at 48 h for Hurricane Nadine (2012). In this particular case, the adjoint model shows strong sensitivity in the TC outflow near the entrance region of an upper-level jet. The impact of dropsondes from data denial experiments and adjoint-based observation impact calculations will be

Basal metabolism in tropical birds: latitude, altitude, and the ‘pace of life’

OpenAIRE

Londoño, Gustavo Adolfo

2015-01-01

Life history varies across latitudes, with the ‘pace of life’ being ‘slower’ in tropical regions. Because life history is coupled to energy metabolism via allocation tradeoffs and links between performance capacity and energy use, low metabolic intensity is expected in tropical animals. Low metabolism has been reported for lowland tropical birds, but it is unclear if this is due to ‘slow’ life history or to a warm, stable environment. We measured basal metabolic rates (BMR) of 253 bird spe...

Are Mixed Tropical Tree Plantations More Resistant to Drought than Monocultures?

Directory of Open Access Journals (Sweden)

Norbert Kunert

2015-06-01

Full Text Available Tropical tree plantations usually consist of a single exotic fast growing species, but recent research describes positive effects on ecosystem functions from mixed tropical tree plantations. In this review, we present the current knowledge of drought resistance of tropical mixed species plantations and summarize preliminary evidence from a tree biodiversity experiment in Panama. Converting mono-specific stands into mixed ones may improve stand stability and might reduce increasing abiotic and biotic disturbances due to climate change. However, little is known about the extent to which tropical tree species or tropical tree communities can resist increasing disturbances in the short term, e.g., water limitations due to increasing dry season intensity or length, or about their resilience after such disturbances and their capacity to adapt to changing conditions in the long term. Studies relating drought resistance and resilience to community diversity are missing. Further, we highlight the urgent need for a multifactorial manipulative throughfall reduction experiment in tropical environments. The outcome of such studies would greatly assist the forestry sector in tropical regions to maintain highly productive and ecologically sound forest plantations in a changing climate.

Tropical Cyclone Signatures in Atmospheric Convective Available Potential Energy

Science.gov (United States)

Studholme, Joshua; Gulev, Sergey

2016-04-01

Tropical cyclones play an important role in the climate system providing transports of energy and water vapor, forcing the ocean, and also affecting mid-latitude circulation phenomena. Tropical cyclone tracks experience strong interannual variability and in addition, longer term trend-like changes in all ocean basins. Analysis of recent historical data reveal a poleward shift in the locations of tropical cyclone tracks in both the Northern and Southern Hemispheres (Kossin et al. 2014, Nature, 509, 349-352). The physical consequences of these alterations are largely unconstrained. For example, the increasing encroachment of tropical cyclone activity into the extra-tropical environment presents a novel and still poorly understood paradigm for tropical-extratropical interactions. In this respect, the role that the atmospheric convective available potential energy (CAPE) plays in the dynamics of tropical cyclones is highly interesting. The two characteristic global-scale spatial patterns in CAPE are identified using EOF analysis. The first pattern shows an abundance of CAPE in the centre of the Pacific and corresponds to the El Nino Southern Oscillation. The second one is capturing positive CAPE anomalies in the oceanic tropics and negative anomalies over equatorial Africa. Associated with these buoyancy patterns, alterations in tropical cyclone activity occur in all basins forming both zonal and meridional patterns. Atmospheric buoyancy is the trigger for deep convection, and subsequently cyclone genesis. This is the mechanism of impact upon location at the start of cyclone tracks. It is found to have less impact upon where cyclones subsequently move, whether or not they undergo extratropical transition and when and where they experience lysis. It is shown that CAPE plays a critical role in the general circulation in the tropics which in turn is the larger steering context for embedded systems within the Walker and Hadley cells. So this lack of `latter life' impact

A biogeographical study on tropical flora of southern China.

Science.gov (United States)

Zhu, Hua

2017-12-01

The tropical climate in China exists in southeastern Xizang (Tibet), southwestern to southeastern Yunnan, southwestern Guangxi, southern Guangdon, southern Taiwan, and Hainan, and these southern Chinese areas contain tropical floras. I checked and synonymized native seed plants from these tropical areas in China and recognized 12,844 species of seed plants included in 2,181 genera and 227 families. In the tropical flora of southern China, the families are mainly distributed in tropical areas and extend into temperate zones and contribute to the majority of the taxa present. The genera with tropical distributions also make up the most of the total flora. In terms of geographical elements, the genera with tropical Asian distribution constitute the highest proportion, which implies tropical Asian or Indo-Malaysia affinity. Floristic composition and geographical elements are conspicuous from region to region due to different geological history and ecological environments, although floristic similarities from these regions are more than 90% and 64% at the family and generic levels, respectively, but lower than 50% at specific level. These differences in the regional floras could be influenced by historical events associated with the uplift of the Himalayas, such as the southeastward extrusion of the Indochina geoblock, clockwise rotation and southeastward movement of Lanping-Simao geoblock, and southeastward movement of Hainan Island. The similarity coefficients between the flora of southern China and those of Indochina countries are more than 96% and 80% at family and generic levels, indicating their close floristic affinity and inclusion in the same biogeographically floristic unit.

Inovação na Pequena Empresa - Um Estudo de Caso na Tropical Brasil

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Fernando Ribeiro Serra

2007-06-01

Full Text Available Title: INNOVATION IN SMALL BUSINESS – TROPICAL BRASIL CASE STUDY Innovation is remarked by several authors as a strategy and need for companies survival on a changing environment. The adoption of an innovation culture is not an easy task. Innovation comes from the change and requires an adequate organizational environment. The organization environment must allow and incentive creativity and trial errors acceptance. This article discusses and characterizes the innovation in a small company environment: Tropical Brasil. Company analysis is based in working papers and previous researches. It suggests that an innovation culture is related to the entrepreneur, its goals and beliefs. To the way he manage the business “infecting” all people with his will and anxiety for doing better.

Trade, tropical deforestation and policy interventions

International Nuclear Information System (INIS)

Barbier, E.B.; Rauscher, M.

1992-01-01

This paper examines several aspects of the links between the trade in tropical timber and deforestation from the perspective of an exporting country. The various versions of the model developed here have highlighted a number of important features of this linkage. First, if the producer country values its tropical forest solely as a source of timber export earnings then it will aim for a smaller forest stock in the long run than if it also considers the other values provided by the forest. Second, if importing nations want the exporting countries to conserve more of their forests, trade interventions appear to be second-best way of achieving this result. Third, increased market power by a large country exporter or group of exporters may actually lead to greater forest conservation. Finally, the existence of a foreign capital market may further ensure that the tropical timber country may conserve its forest stock in the long run. Several recent reviews of global forest sector policies have discussed implications similar to those analyzed theoretically in our model. Generally, the same conclusions have been reached. However, what is of increasing concern is that domestic market and policy failures within tropical forest countries continue to distort the incentives for more sustainable management of timber production and efficient development of processing capacity, while at the same time the international community increasingly contemplates the use of bans, tariffs and other trade measures to discourage 'unsustainable' tropical timber exploitation. As our paper has attempted to show, sometimes the more simple solutions lead neither to a straightforward, nor to the desired, results. 18 refs, 1 fig

Indoor Thermal Environment in Tropical Climate Residential Building

Directory of Open Access Journals (Sweden)

Jamaludin Nazhatulzalkis

2014-01-01

Full Text Available Indoor thermal environment is one of the criteria in sustainable building. This criterion is important in ensuring a healthy indoor environment for the occupants. The consideration of environmental concerns at the early design stage would effectively integrate the sustainability of the building environment. Global climate changes such as global warming do affect human comfort since people spend most of their time and activities in the building. The increasing of urban population required additional housing for households, as well as places to shop, office and other facilities. Occupants are now more conscious the importance of sustainability for a better quality of life. Good thermal environment is essential for human wellness and comfort. A residential environment will influence residents’ health and safety. The global warming increase the earth’s temperature and greenhouse emission to the atmosphere cause adverse effects to the outdoor environment. Residential developments modify the materials, structure and energy balance in urban climate effects of human economic activities. As an indoor environment is influenced by the outdoor condition, the factors affecting indoor thermal environment are crucial in improving a comfortable and healthy environment in residential building. The microclimatic of a site such as temperature and relative humidity, and wind movement led to the variation of indoor thermal environment in the building.

Nurture net of nature: Re-evaluating the role of shared environments in academic achievement and verbal intelligence.

Science.gov (United States)

Daw, Jonathan; Guo, Guang; Harris, Kathie Mullan

2015-07-01

Prominent authors in the behavioral genetics tradition have long argued that shared environments do not meaningfully shape intelligence and academic achievement. However, we argue that these conclusions are erroneous due to large violations of the additivity assumption underlying behavioral genetics methods - that sources of genetic and shared and nonshared environmental variance are independent and non-interactive. This is compounded in some cases by the theoretical equation of the effective and objective environments, where the former is defined by whether siblings are made more or less similar, and the latter by whether siblings are equally subject to the environmental characteristic in question. Using monozygotic twin fixed effects models, which compare outcomes among genetically identical pairs, we show that many characteristics of objectively shared environments significantly moderate the effects of nonshared environments on adolescent academic achievement and verbal intelligence, violating the additivity assumption of behavioral genetic methods. Importantly, these effects would be categorized as nonshared environmental influences in standard twin models despite their roots in shared environments. These findings should encourage caution among those who claim that the frequently trivial variance attributed to shared environments in behavioral genetic models means that families, schools, and neighborhoods do not meaningfully influence these outcomes. Copyright © 2015. Published by Elsevier Inc.

Increasing carbon storage in intact African tropical forests

NARCIS (Netherlands)

Lewis, S.L.; Lopez-Gonzalez, G.; Sonké, B.; Affum-Baffoe, K.; Ewango, C.E.N.

2009-01-01

The response of terrestrial vegetation to a globally changing environment is central to predictions of future levels of atmospheric carbon dioxide1, 2. The role of tropical forests is critical because they are carbon-dense and highly productive3, 4. Inventory plots across Amazonia show that

The effect of Scratch environment on student’s achievement in teaching algorithm

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Mehmet Tekerek

2014-08-01

Full Text Available In this study, the effect of Scratch environment in teaching algorithm in elementary school 6th grade Information and Communication Technologies course was examined. The research method was experimental method. Control group, pretest-posttest design of experimental research method and a convenience sample consisting of 60 6th grade students were used. The research instrument was achievement test to determine the effect of Scratch on learning algorithm. During the implementation process experiment group studied using Scratch and control group studied with traditional methods. The data was analyzed using independent-samples t-test, paired-samples t-test and ANCOVA statistics. According to findings there is no statically significant difference between posttest achievement scores of experiment and control groups. Similarly, In terms of gender there isn’t a statically significant difference between posttest scores of experiment and control groups.

The geology of selected peat-forming environments in temperate and tropical latitudes

Science.gov (United States)

Cameron, C.C.; Palmer, C.A.; Esterle, J.S.

1990-01-01

We studied peat in several geologic and climatic settings: (1) a glaciated terrain in cold-temperate Maine and Minnesota, U.S.A.; (2) an island in a temperate maritime climate in the Atlantic Ocean off the coast of Maine, U.S.A., where sea level is rising rapidly and changing the environment of peat accumulation; (3) swamps along the warm-temperate U.S. Atlantic and Gulf Coastal Plains, where sea level has changed often, thus creating sites for accumulation; and (4) in a tropical climate along the coast of Sarawak, Malaysia, and the delta of the Batang Hari River, Sumatra, Indonesia (Figs. 1 and 2). With the exception of the deposits on the Atlantic and Gulf Coastal Plains, most of the deposits described are domed bogs in which peat accumulation continued above the surface of the surrounding soil. The bogs of the U.S. Atlantic and Gulf Coastal Plains have almost level surfaces. All domed bogs are not entirely ombrotrophic (watered only from precipitation); multidomed bogs that rise from irregular or hilly surfaces may be crossed by streams that supply water to the bogs. The geologic processes or organic sedimentation, namely terrestrialization and paludification, are similar in all peat deposits considered here. Differences in geomorphology affecting the quantity and that quality of peat that has ash contents of less than 25%, which are desirable for commercial purposes, depend chiefly on: (1) high humidity, which is favorable to luxuriant growth of peat-forming vegetation; (2) a depositional setting that permits extensive accumulation relatively free from inorganic contamination from sea water and streams and from dust and volcanic ash; and (3) a stable regional water table that controls the rate of decomposition under aerobic conditions and protects the deposit against the ravages of fire. Differences in peat textures are due to the type of vegetation and to the degree of decomposition. The rate of decomposition is largely the result of the amount of oxidation

Mapping informal small-scale mining features in a data-sparse tropical environment with a small UAS

Science.gov (United States)

Chirico, Peter G.; Dewitt, Jessica D.

2017-01-01

This study evaluates the use of a small unmanned aerial system (UAS) to collect imagery over artisanal mining sites in West Africa. The purpose of this study is to consider how very high-resolution imagery and digital surface models (DSMs) derived from structure-from-motion (SfM) photogrammetric techniques from a small UAS can fill the gap in geospatial data collection between satellite imagery and data gathered during field work to map and monitor informal mining sites in tropical environments. The study compares both wide-angle and narrow field of view camera systems in the collection and analysis of high-resolution orthoimages and DSMs of artisanal mining pits. The results of the study indicate that UAS imagery and SfM photogrammetric techniques permit DSMs to be produced with a high degree of precision and relative accuracy, but highlight the challenges of mapping small artisanal mining pits in remote and data sparse terrain.

The Relationship Among Socioeconomic Status, Home Environment, Parent Involvement, Child Self Concept and Child Achievement.

Science.gov (United States)

Revicki, Dennis A.

The relationship among socio-economic status, sibling variables, social-psychological home environment, parent involvement in intervention programs, and child self-concept and achievement were empirically investigated to determine the importance and kind of parent participation most closely related to childrens' cognitive and affective…

Achieving behavioral control with millisecond resolution in a high-level programming environment.

Science.gov (United States)

Asaad, Wael F; Eskandar, Emad N

2008-08-30

The creation of psychophysical tasks for the behavioral neurosciences has generally relied upon low-level software running on a limited range of hardware. Despite the availability of software that allows the coding of behavioral tasks in high-level programming environments, many researchers are still reluctant to trust the temporal accuracy and resolution of programs running in such environments, especially when they run atop non-real-time operating systems. Thus, the creation of behavioral paradigms has been slowed by the intricacy of the coding required and their dissemination across labs has been hampered by the various types of hardware needed. However, we demonstrate here that, when proper measures are taken to handle the various sources of temporal error, accuracy can be achieved at the 1 ms time-scale that is relevant for the alignment of behavioral and neural events.

An innovative roofing system for tropical building interiors: Separating heat from useful visible light

Energy Technology Data Exchange (ETDEWEB)

Al-Obaidi, K.M.; Ismail, M.; Abdul Rahman, A.M. [School of Housing, Building and Planning, Universiti Sains Malaysia, 11800, Minden, Pulau Pinang (Malaysia)

2013-07-01

Generally it has been known that energy consumption costs are high in temperate countries. In buildings, room spaces are normally designed so as to consume less energy for thermal comfort especially in winter. Passive strategies such large double-glazing windows are to contain heat indoors and also for maximum daylight to reduce dependence on artificial lighting. Thus roof lights are popular building design elements in cold and temperate countries. Unlike in the tropics where it has high temperatures and humidity throughout the year, achieving indoor comfort is a challenge especially with plenty of sunshine and unpredictable wind conditions. This paper explores the possibility of roof light for indoor comfort to be considered as a tropical design element. Initial simulation was carried out before any attempt to do life-sized model for empirical data. By simulation, the hypothesis has been achieved but several factors have to be considered. The solution is not as simple as those achieved in the temperate countries. Comfort can be achieved but permutations of several design factors such as dimensions of room, glazing, reflective materials, blackbody concept and building materials need adjustment to meet the Malaysian Comfort Temperature. With this finding the Tropical Architecture would then be redefined with the introduction of this Innovative Roofing System (IRS) as named by the author.

Isolation of a novel strain of Planomicrobium chinense from diesel contaminated soil of tropical environment.

Science.gov (United States)

Das, Reena; Tiwary, Bhupendra N

2013-09-01

A novel bacterial strain (B6) degrading high concentration of diesel oil [up to 2.5% (v/v)] was isolated from a site contaminated with petroleum hydrocarbons in the state of Chhattisgarh, India. The strain demonstrated efficient degradation for diesel oil range alkanes (C14 to C36 i.e., mostly linear chain alkanes). It was identified to be 99% similar to Planomicrobium chinense on the basis of partial 16S rRNA gene sequencing and biochemical characteristics. The efficiency of degradation was optimized at pH 7.2 and temperature at 32 °C. GC analysis demonstrated complete mineralization of higher chain alkanes into lower chain alkanes within 96 h. The organism also displayed surface tension reduction by producing stable emulsification on the onset of stationary phase. A multidimensional characteristics of the strain to grow at a high temperature range, resistance to various heavy metals as well as tolerance to moderate concentration of NaCl makes it suitable for bioremediation of soil contaminated with diesel oil in tropical environment. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interpretations of education about gene-environment influences on health in rural Ethiopia: the context of a neglected tropical disease.

Science.gov (United States)

Tora, Abebayehu; Ayode, Desta; Tadele, Getnet; Farrell, David; Davey, Gail; McBride, Colleen M

2016-07-01

Misunderstandings of the role of genetics in disease development are associated with stigmatizing behaviors and fatalistic attitudes about prevention. This report describes an evaluation of community understanding of an educational module about genetic and environmental influences on the development of podoconiosis, a neglected tropical disease endemic in highland Ethiopia. A qualitative process assessment was conducted as part of a large prospective intervention trial in August 2013, in Wolaita Zone, southern Ethiopia. Sixty five participants were purposively selected from 600 households randomized to receive the inherited susceptibility module. The educational module used pictorial representations and oral explanations of the interaction of inherited sensitivity and soil exposure and was delivered by lay health educators in participants' homes. Data were collected using semi-structured individual interviews (IDIs) or focus group discussions (FGDs). Qualitative analyses showed that most participants improved their understanding of inherited soil sensitivity and susceptibility to podoconiosis. Participants linked their new understanding to decreased stigma-related attitudes. The module also corrected misconceptions that the condition was contagious, again diminishing stigmatizing attitudes. Lastly, these improvements in understanding increased the perceived value of foot protection. Taken together, these improvements support the acceptability, feasibility and potential benefits of implementing gene-environment education in low and middle income countries. © The Author 2016. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.

Remote Sensing Tropical Coral Reefs: The View from Above

Science.gov (United States)

Purkis, Sam J.

2018-01-01

Carbonate precipitation has been a common life strategy for marine organisms for 3.7 billion years, as, therefore, has their construction of reefs. As favored by modern corals, reef-forming organisms have typically adopted a niche in warm, shallow, well-lit, tropical marine waters, where they are capable of building vast carbonate edifices. Because fossil reefs form water aquifers and hydrocarbon reservoirs, considerable effort has been dedicated to understanding their anatomy and morphology. Remote sensing has a particular role to play here. Interpretation of satellite images has done much to reveal the grand spatial and temporal tapestry of tropical reefs. Comparative sedimentology, whereby modern environments are contrasted with the rock record to improve interpretation, has been particularly transformed by observations made from orbit. Satellite mapping has also become a keystone technology to quantify the coral reef crisis—it can be deployed not only directly to quantify the distribution of coral communities, but also indirectly to establish a climatology for their physical environment. This article reviews the application of remote sensing to tropical coralgal reefs in order to communicate how this fast-growing technology might be central to addressing the coral reef crisis and to look ahead at future developments in the science.

Remote Sensing Tropical Coral Reefs: The View from Above.

Science.gov (United States)

Purkis, Sam J

2018-01-03

Carbonate precipitation has been a common life strategy for marine organisms for 3.7 billion years, as, therefore, has their construction of reefs. As favored by modern corals, reef-forming organisms have typically adopted a niche in warm, shallow, well-lit, tropical marine waters, where they are capable of building vast carbonate edifices. Because fossil reefs form water aquifers and hydrocarbon reservoirs, considerable effort has been dedicated to understanding their anatomy and morphology. Remote sensing has a particular role to play here. Interpretation of satellite images has done much to reveal the grand spatial and temporal tapestry of tropical reefs. Comparative sedimentology, whereby modern environments are contrasted with the rock record to improve interpretation, has been particularly transformed by observations made from orbit. Satellite mapping has also become a keystone technology to quantify the coral reef crisis-it can be deployed not only directly to quantify the distribution of coral communities, but also indirectly to establish a climatology for their physical environment. This article reviews the application of remote sensing to tropical coralgal reefs in order to communicate how this fast-growing technology might be central to addressing the coral reef crisis and to look ahead at future developments in the science.

Why tropical forest lizards are vulnerable to climate warming

Science.gov (United States)

Huey, Raymond B.; Deutsch, Curtis A.; Tewksbury, Joshua J.; Vitt, Laurie J.; Hertz, Paul E.; Álvarez Pérez, Héctor J.; Garland, Theodore

2009-01-01

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. PMID:19324762

Determinants of radiological dose from Sr and Cs accumulated by tropical freshwater fish

International Nuclear Information System (INIS)

Twining, J.R.; Markich, S.J.; Ferris, J.M.

1998-01-01

Recent studies of the bioaccumulation of strontium and caesium by tropical freshwater fish were in some ways consistent with temperate data. For example, biodistribution of radionuclides and the influence of chemical analogues Ca and K were in general agreement with earlier data. However, in other matters there were systematic inconsistencies when compared with the standard IAEA models. These differences gave rise to transfer (concentration) factors for both Cs and Sr that were approximately an order of magnitude below the expected values based on temperate data (e.g. 13 and 0.7 compared with 440 and 4.7 respectively). Compatible results were found for a range of tropical species studied by different investigators. In this presentation, some of the factors believed to influence bioaccumulation, and hence radiological dose, in tropical environments are discussed in relation to the above findings. These factors include: water physico-chemistry, temperature, fish size and physiology, whether or not the data were acquired from field or laboratory studies, and how the studies were carried out. Critical group exposure pathways in tropical environments and the benefits and shortcomings of applying default temperate models of Cs and Sr accumulation by freshwater fish are also discussed. (author)

Field study of thermal comfort in non-air-conditioned buildings in a tropical island climate.

Science.gov (United States)

Lu, Shilei; Pang, Bo; Qi, Yunfang; Fang, Kun

2018-01-01

The unique geographical location of Hainan makes its climate characteristics different from inland areas in China. The thermal comfort of Hainan also owes its uniqueness to its tropical island climate. In the past decades, there have been very few studies on thermal comfort of the residents in tropical island areas in China. A thermal environment test for different types of buildings in Hainan and a thermal comfort field investigation of 1944 subjects were conducted over a period of about two months. The results of the survey data show that a high humidity environment did not have a significant impact on human comfort. The neutral temperature for the residents in tropical island areas was 26.1 °C, and the acceptable temperature range of thermal comfort was from 23.1 °C to 29.1 °C. Residents living in tropical island areas showed higher heat resistance capacity, but lower cold tolerance than predicted. The neutral temperature for females (26.3 °C) was higher than for males (25.8 °C). Additionally, females were more sensitive to air temperature than males. The research conclusions can play a guiding role in the thermal environment design of green buildings in Hainan Province. Copyright © 2017 Elsevier Ltd. All rights reserved.

Tritium behavior pattern in some soil-plant systems in a tropical environment

International Nuclear Information System (INIS)

Soman, S.D.; Iyengar, T.S.; Sadarangani, S.H.; Vaze, P.K.

1975-01-01

A study of the distribution pattern of tritium in the soil/plant environment gives valuable ecological information on the natural water balance. The results of such a study for the conditions obtaining in India are given in this paper. Field studies are carried out by injection of tritium into some soil/plant systems and following the transfer pathways. The method of extraction for tissue-free-water-tritium (TFWT) is based on the vacuum freeze-drying technique while the tissue-bound-tritium (TBT) is estimated by a modified version of the Shoniger method. The determination of residence time of tritium in aqueous and organic phase in a number of tropical trees has been carried out both for stem-injection as well as intake from the soil. From the results of this study the tree biomass and transpiration rates have been determined. The tritium profile over time, for an acute exposure in certain trees such as Morinda Tinetoria, Achras Sapota etc. shows significantly different patterns compared to the normal pattern shown by Mangifera Indica, Terminalia Catappa, Ficus Glomerata etc. The period of investigation in each case varied from 400 to 1000 h. In most of the cases, the TBT fractions were very low compared to TFWT fractions in the initial stages. The tritium behavior in the tree reflects significant characteristics of the tritium behavior in the soil system. The authors have found that the leaf sampling can be used as an indicator of total environmental tritium behavior. (author)

Impacts of Particulate Matter on Gulf of Mexico Tropical Cyclones

Science.gov (United States)

Cao, W.; Rohli, R. V.

2017-12-01

The purpose of this project is to analyze the relationship between tropical cyclones of the Gulf of Mexico-Atlantic basin and fine particulate matter (PM2.5). The daily mean PM2.5 concentration values were collected from United States Environmental Protection Agency (EPA). Tropical cyclone data were collected from Tropical Prediction Center Best Track Reanalysis in Unisys Weather®. The GRIdded Binary (GRIB-formatted) data were downloaded from the Data Support Section of the Computational and Information Systems Laboratory at the National Center for Atmospheric Research (NCAR). Through ArcGIS®, the tropical cyclone tracks were compared with the interpolated daily mean PM2.5 concentration value. Results suggest that the tracks tend to avoid areas with higher PM2.5 concentrations, and the intensity was weakened significantly after passing the PM2.5-rich area. Through simulation using the Weather Research and Forecasting (WRF) model, the pressure and vertical structure of Hurricane Lili were weakened after passing the most PM2.5-rich area in Louisiana. Also, little evidence is found for the possibility of precipitation generated by the approaching tropical cyclone to cleanse the atmosphere of PM2.5 before storm passage. These results have important implications for tropical cyclone prediction as storms approach polluted areas or other places where PM2.5 particles are abundant, not only including urban environments but also in coastal areas where proscribed burns take place during tropical cyclone season, such as during sugarcane harvesting in southern Louisiana.

Assessing atmospheric particulate matter distribution based on Saturation Isothermal Remanent Magnetization of herbaceous and tree leaves in a tropical urban environment.

Science.gov (United States)

Barima, Yao Sadaiou Sabas; Angaman, Djédoux Maxime; N'gouran, Kobenan Pierre; Koffi, N'guessan Achille; Kardel, Fatemeh; De Cannière, Charles; Samson, Roeland

2014-02-01

Particulate matter (PM) emissions, and the associated human health risks, are likely to continue increasing in urban environments of developing countries like Abidjan (Ivory Cost). This study evaluated the potential of leaves of several herbaceous and tree species as bioindicators of urban particulate matter pollution, and its variation over different land use classes, in a tropical area. Four species well distributed (presence frequencies >90%) over all land use classes, easy to harvest and whose leaves are wide enough to be easily scanned were selected, i.e.: Amaranthus spinosus (Amaranthaceae), Eleusine indica (Poaceae), Panicum maximum (Poaceae) and Ficus benjamina (Moraceae). Leaf sampling of these species was carried out at 3 distances from the road and at 3 height levels. Traffic density was also noted and finally biomagnetic parameters of these leaves were determined. Results showed that Saturation Isothermal Remanent Magnetization (SIRM) of leaves was at least 4 times higher (27.5×10(-6)A) in the vicinity of main roads and industrial areas than in parks and residential areas. The main potential sources of PM pollution were motor vehicles and industries. The slightly hairy leaves of the herbaceous plant A. spinosus and the waxy leaves of the tree F. benjamina showed the highest SIRM (25×10(-6)A). Leaf SIRM increased with distance to road (R(2)>0.40) and declined with sampling height (R(2)=0.17). The distance between 0 and 5m from the road seemed to be the most vulnerable in terms of PM pollution. This study has showed that leaf SIRM of herbaceous and tree species can be used to assess PM exposure in tropical urban environments. © 2013.

Analysis and evaluation of tillage on an alfisol in a semi-arid tropical region of India

NARCIS (Netherlands)

Klaij, M.C.

1983-01-01

Tillage field experiments were conducted on Alfisols in a semi-arid tropical environment in India. The research was conducted within the framework of the Farming Systems Research Program of the International Crops Research Institute for the Semi-Arid Tropics (ICRISAT).

To put the

Effects of the genotype and environment interaction on sugar accumulation in sweet sorghum varieties (Sorghum bicolor -{L.}- Moench grown in the lowland tropics of Colombia

Directory of Open Access Journals (Sweden)

Jaime Humberto Bernal

2014-12-01

Full Text Available Sugar production in sweet sorghums is affected by the environment. Therefore, in this study on the effects of the genotype x environment interaction on sugar accumulation, plant traits associated with the sugar content in the stem were evaluated in ten sorghum genotypes grown in six contrasting environments. The results indicated that the stem dry weight, juice sugar concentration (°Brix, stem sugar content and juice volume were controlled by the genetic constitution of the genotype, with a large environmental contribution to their expression. The results allowed for the identification of the sweet sorghum genotypes that have a high potential for the biofuel agroindustry due to their high sugar contents in the environmental conditions of Palmira, Espinal, Cerete and Codazzi. Humid tropical environments such as Gaitan and Villavicencio were less favorable for the competitive production of sweet sorghums for bioethanol due to their low levels of solar radiation and soil fertility.

Addressing the social determinants of neglected tropical diseases to ...

African Journals Online (AJOL)

... work brings to focus the determinants, which have been found to be particularly important for the perpetuation of Neglected Tropical Diseases (NTDs) in endemic communities: water and sanitation, housing and clustering, environment, migration, disasters and conflicts, socio-cultural factors and gender, and finally poverty.

Latest Achievements on Climate Change and Forest Interactions in a Polluted Environment

DEFF Research Database (Denmark)

Carriero, Giulia; Tuovinen, Juha-Pekka; Clarke, Nicholas

2014-01-01

the information from European forest research/monitoring networks; the development of a new concept of forest sites for research and monitoring (Supersites); the identification of the main knowledge gaps; and the definition of priorities for forest adaptation to climate change in a polluted environment...... pollution dynamics into prospects for forest research and monitoring, with focus on the carbon, ozone, nitrogen and water budgets. The aim of this paper is to summarize scientific activities and achievements of MAFor: the creation of a meta-database for highlighting the available data and integrating...

Why do forest products become less available? A pan-tropical comparison of drivers of forest-resource degradation

OpenAIRE

Hermans, Kathleen; Gerstner, Katharina; Geijzendorffer, Ilse R.; Herold, Martin; Seppelt, Ralf; Wunder, Sven

2016-01-01

Forest products provide an important source of income and wellbeing for rural smallholder communities across the tropics. Although tropical forest products frequently become over-exploited, only few studies explicitly address the dynamics of degradation in response to socio-economic drivers. Our study addresses this gap by analyzing the factors driving changes in tropical forest products in the perception of rural smallholder communities. Using the poverty and environment network global datas...

Violence, bullying and academic achievement: a study of 15-year-old adolescents and their school environment.

Science.gov (United States)

Strøm, Ida Frugård; Thoresen, Siri; Wentzel-Larsen, Tore; Dyb, Grete

2013-04-01

This study investigated academic achievement among adolescents exposed to violence, sexual abuse and bullying. Moreover, we sought to determine the individual and contextual influence of the adolescents' school environment in terms of bullying, classmate relationships and teacher support on academic achievement. Finally, we wished to assess whether school-level influence is different for the adolescents exposed to violence and sexual abuse versus the adolescents not exposed to these forms of abuse. This is a cross-sectional study of a sample of 7,343 adolescents between the ages of 15 and 16 from 56 schools in Oslo, Norway. We investigated associations between violence, sexual abuse, bullying, classmate relationships, teacher support and academic achievement. Linear regression was used to investigate associations on the individual level. Multilevel analyses were conducted to test for school level differences while controlling for both individual and contextual factors. On the individual level, all combinations of violence and sexual abuse categories were significantly associated with lower grades. This was also true for bullying, while teacher support resulted in better grades. At the school level, the analysis showed that students in schools with higher levels of bullying performed worse academically. Each unit of increment in bullying in school corresponded to an average 0.98 point decrease in grades (pschool environment and adolescent exposure to violence, indicating that the school environment affects all students. Factors on both levels can contribute to reduced grades. This stresses the need to investigate individual and contextual factors simultaneously when examining academic achievement. Our results indicated that students attending schools with higher levels of bullying may show poorer school performance. This was true for all students regardless of previous exposure to violence and sexual abuse. This emphasizes the need for preventive efforts that focus

The potential sensitivity of tropical plants to increased ultraviolet-B radiation

International Nuclear Information System (INIS)

Ziska, L.H.

1996-01-01

Little is known concerning the impact of stratospheric ozone depletion and increasing ultraviolet (UV)-B radiation on the phenology and growth of tropical plants. This is because, ostensibly, tropical plants are already exposed to relatively high levels of UV-B radiation (relative to a temperate environment) and should, therefore, possess a greater degree of tolerance to increased UV-B radiation. In this brief review I hope to show that, potentially, direct and indirect effects on photosynthesis, assimilate partitioning, phenology and biomass could occur in both tropical crops (e.g. cassava, rice) and native species (e.g. Cecropia obtusifolia (Bertol. Fl)., Tetramolopium humile (Gray), Nana sandwicensis L.). However, it should be noted that differences in sensitivity to UV-B radiation can be related to experimental conditions, and care should be taken to ensure that the quantity and quality of background solar radiation remains at near ambient conditions. Nevertheless, by integrating current and past studies on the impact of UV-B radiation on tropical species, I hope to be able to demonstrate that photosynthesis, morphology and growth in tropical plants could be directly affected by UV-B radiation and that UV-B radiation may be a factor in species and community dynamics in natural plant populations in the tropics

Response of marine copepods to a changing tropical environment: winners, losers and implications.

Science.gov (United States)

Chew, Li Lee; Chong, Ving Ching

2016-01-01

Background. Climate change concurrent with anthropogenic disturbances can initiate serial changes that reverberate up the food chain with repercussions for fisheries. To date, there is no information available concerning the combined effects of global warming and human impacts on tropical marine food webs. While temperate copepods respond differently to warming and environmental stressors, the extent to which tropical copepods can adapt to rising temperature of already warm waters remains unknown. We hypothesize that sea warming and other anthropogenic disturbances over the long term will have the greatest impact on the copepod community in nearshore waters where their effects are accentuated, and therefore vulnerable and resilient species could be identified. Methods. Zooplankton samples were collected during two time periods (1985-86 and 2014-15) interposed by marked anthropogenic disturbances, and at the same five stations located progressively from inshore to offshore in Klang Strait, Malaysia, following the asymmetrical before-after-control-impact (BACI) design. Copepods were identified to species, and results were interpreted by univariate (ANOVA) and multivariate (PERMANOVA, PCO) analyses of the computed species abundance and diversity measures. Results. Copepod total abundance was not significantly different among stations but higher after disturbance than before disturbance. However, changes in the abundance of particular species and the community structure between time periods were dramatic. Coastal large-bodied calanoid species (e.g., Acartia spinicauda, Calanopia thompsoni, Pseudodiaptomus bowmani and Tortanus forcipatus) were the most vulnerable group to disturbance. This however favored the opportunistic species (e.g., Oithona simplex, O. attenuata, Hemicyclops sp., Pseudomacrochiron sp. and Microsetella norvegica). Small-bodied copepods (e.g., Paracalanus sp., Parvocalanus crassirostris and Euterpina acutifrons) were unaffected. Centropages

Response of marine copepods to a changing tropical environment: winners, losers and implications

Directory of Open Access Journals (Sweden)

Li Lee Chew

2016-05-01

Full Text Available Background. Climate change concurrent with anthropogenic disturbances can initiate serial changes that reverberate up the food chain with repercussions for fisheries. To date, there is no information available concerning the combined effects of global warming and human impacts on tropical marine food webs. While temperate copepods respond differently to warming and environmental stressors, the extent to which tropical copepods can adapt to rising temperature of already warm waters remains unknown. We hypothesize that sea warming and other anthropogenic disturbances over the long term will have the greatest impact on the copepod community in nearshore waters where their effects are accentuated, and therefore vulnerable and resilient species could be identified. Methods. Zooplankton samples were collected during two time periods (1985–86 and 2014–15 interposed by marked anthropogenic disturbances, and at the same five stations located progressively from inshore to offshore in Klang Strait, Malaysia, following the asymmetrical before-after-control-impact (BACI design. Copepods were identified to species, and results were interpreted by univariate (ANOVA and multivariate (PERMANOVA, PCO analyses of the computed species abundance and diversity measures. Results. Copepod total abundance was not significantly different among stations but higher after disturbance than before disturbance. However, changes in the abundance of particular species and the community structure between time periods were dramatic. Coastal large-bodied calanoid species (e.g., Acartia spinicauda, Calanopia thompsoni, Pseudodiaptomus bowmani and Tortanus forcipatus were the most vulnerable group to disturbance. This however favored the opportunistic species (e.g., Oithona simplex, O. attenuata, Hemicyclops sp., Pseudomacrochiron sp. and Microsetella norvegica. Small-bodied copepods (e.g., Paracalanus sp., Parvocalanus crassirostris and Euterpina acutifrons were unaffected

Response of marine copepods to a changing tropical environment: winners, losers and implications

Science.gov (United States)

Chew, Li Lee

2016-01-01

Background. Climate change concurrent with anthropogenic disturbances can initiate serial changes that reverberate up the food chain with repercussions for fisheries. To date, there is no information available concerning the combined effects of global warming and human impacts on tropical marine food webs. While temperate copepods respond differently to warming and environmental stressors, the extent to which tropical copepods can adapt to rising temperature of already warm waters remains unknown. We hypothesize that sea warming and other anthropogenic disturbances over the long term will have the greatest impact on the copepod community in nearshore waters where their effects are accentuated, and therefore vulnerable and resilient species could be identified. Methods. Zooplankton samples were collected during two time periods (1985–86 and 2014–15) interposed by marked anthropogenic disturbances, and at the same five stations located progressively from inshore to offshore in Klang Strait, Malaysia, following the asymmetrical before-after-control-impact (BACI) design. Copepods were identified to species, and results were interpreted by univariate (ANOVA) and multivariate (PERMANOVA, PCO) analyses of the computed species abundance and diversity measures. Results. Copepod total abundance was not significantly different among stations but higher after disturbance than before disturbance. However, changes in the abundance of particular species and the community structure between time periods were dramatic. Coastal large-bodied calanoid species (e.g., Acartia spinicauda, Calanopia thompsoni, Pseudodiaptomus bowmani and Tortanus forcipatus) were the most vulnerable group to disturbance. This however favored the opportunistic species (e.g., Oithona simplex, O. attenuata, Hemicyclops sp., Pseudomacrochiron sp. and Microsetella norvegica). Small-bodied copepods (e.g., Paracalanus sp., Parvocalanus crassirostris and Euterpina acutifrons) were unaffected. Centropages

Effect of Motivational Scaffolding on E-Learning Environments: Self-Efficacy, Learning Achievement, and Cognitive Style

Science.gov (United States)

Valencia-Vallejo, Nilson; López-Vargas, Omar; Sanabria-Rodríguez, Luis

2018-01-01

The present research studies the effects of motivational scaffolding that favor self-efficacy and improve learning achievement in students with different cognitive styles in the Field Dependence/Independence (FDI) dimension, when they interact in an e-learning environment on mathematics. The research has an experimental design with two groups and…

The relationship between environment, efficacy beliefs, and academic achievement of low-income African American children in special education.

Science.gov (United States)

Bean, Kristen F; Sidora-Arcoleo, Kimberly

2012-01-01

African American students are overrepresented in special education. Ecological systems theory, social cognitive theory, and a literature review demonstrate that children's environments, particularly school, and self-efficacy impact the educational outcomes of African American children. Interventions have aimed to improve children's environmental resources and efficacy. The aim of this study was to assess the impact of environment, efficacy beliefs, and the Nurse-Family Partnership intervention on the educational achievements of African American children in special education. A secondary data analysis of 126 African American children in special education found that self-efficacy and the number of hours spent in special education were associated with their academic achievement.

Tropical Soil Chemistry

DEFF Research Database (Denmark)

Borggaard, Ole K.

and environmental protection. Tropical Soil Chemistry by Ole K. Borggaard provides an overview of the composition, occurrence, properties, processes, formation, and environmental vulnerability of various tropical soil types (using American Soil Taxonomy for classification). The processes and the external factors...... soil chemical issues are also presented to assess when, why, and how tropical soils differ from soils in other regions. This knowledge can help agricultural specialists in the tropics establish sustainable crop production. Readers are assumed to be familiar with basic chemistry, physics...

Predictors of death and production performance of layer chickens in opened and sealed pens in a tropical savannah environment.

Science.gov (United States)

Shittu, Aminu; Raji, Abdullahi Abdullahi; Madugu, Shuaibu A; Hassan, Akinola Waheed; Fasina, Folorunso Oludayo

2014-09-12

Layer chickens are exposed to high risks of production losses and mortality with impact on farm profitability. The harsh tropical climate and severe disease outbreaks, poor biosecurity, sub-minimal vaccination and treatment protocols, poor management practices, poor chick quality, feed-associated causes, and unintended accidents oftentimes aggravate mortality and negatively affect egg production. The objectives of this study were to estimate the probability of survival and evaluate risk factors for death under different intensive housing conditions in a tropical climate, and to assess the production performance in the housing systems. Daily mean mortality percentages and egg production figures were significantly lower and higher in the sealed pens and open houses (P ratio for mortality of layers raised in sealed pens was 0.568 (56.8%). Reasons for spiked mortality in layer chickens may not always be associated with disease. Hot-dry climatic environment is associated with heat stress, waning immunity and inefficient feed usage and increase probability of death with reduced egg production; usage of environmentally controlled building in conditions where environmental temperature may rise significantly above 25°C will reduce this impact. Since younger birds (19-38 weeks) are at higher risk of death due to stress of coming into production, management changes and diseases, critical implementation of protocols that will reduce death at this precarious period becomes mandatory. Whether older chickens' better protection from death is associated with many prophylactic and metaphylactic regimen of medications/vaccination will need further investigation.

Maximum covariance analysis to identify intraseasonal oscillations over tropical Brazil

Science.gov (United States)

Barreto, Naurinete J. C.; Mesquita, Michel d. S.; Mendes, David; Spyrides, Maria H. C.; Pedra, George U.; Lucio, Paulo S.

2017-09-01

A reliable prognosis of extreme precipitation events in the tropics is arguably challenging to obtain due to the interaction of meteorological systems at various time scales. A pivotal component of the global climate variability is the so-called intraseasonal oscillations, phenomena that occur between 20 and 100 days. The Madden-Julian Oscillation (MJO), which is directly related to the modulation of convective precipitation in the equatorial belt, is considered the primary oscillation in the tropical region. The aim of this study is to diagnose the connection between the MJO signal and the regional intraseasonal rainfall variability over tropical Brazil. This is achieved through the development of an index called Multivariate Intraseasonal Index for Tropical Brazil (MITB). This index is based on Maximum Covariance Analysis (MCA) applied to the filtered daily anomalies of rainfall data over tropical Brazil against a group of covariates consisting of: outgoing longwave radiation and the zonal component u of the wind at 850 and 200 hPa. The first two MCA modes, which were used to create the { MITB}_1 and { MITB}_2 indices, represent 65 and 16 % of the explained variance, respectively. The combined multivariate index was able to satisfactorily represent the pattern of intraseasonal variability over tropical Brazil, showing that there are periods of activation and inhibition of precipitation connected with the pattern of MJO propagation. The MITB index could potentially be used as a diagnostic tool for intraseasonal forecasting.

Urban UV environment in a sub-tropical megacity – A measurement and modelling study

Directory of Open Access Journals (Sweden)

Ka-Ming Wai

Full Text Available The variations of solar total UV (UVA + UVB exposure rates in a megacity featured with high-rise buildings during summer months were measured and relevant model predictions were evaluated. The maximum pedestrian-level total solar UV exposure rate was less than the un-obstructed exposure rate at any time, attributing to the prevailing reduction in the diffuse solar radiation due to the obstruction effects of distant buildings. Comparing with the measurements, our coupled model well captured the spatial and temporal variations of the reduction of UV exposure rates. By measurements, large reduction in the solar total UV exposure rate down to 12% of un-obstructed exposure rate due to the building obstruction effects was found, agreeing with our previous simulation results and results from an Australian megacity. On the other hand, building reflection from reflective curtain walls could reach 23% of the un-obstructed solar total UV exposure rate at the ground level. This implied improper building design creating additional harmful effects of solar UV radiation on the environment. The coupled model was also applied to predict the urban UV exposure rates during a tropical-cyclone induced aerosol episode. A well-evaluated urban solar UV model is an important tool for sustainable urban design.

Macrofouling community development at tropical coastal environment (New Mangalore Port, West Coast of India)

Digital Repository Service at National Institute of Oceanography (India)

Venkat, K.; Anil, A.C.; Wagh, A.B.

Recruitment of macrofouling community in tropical waters is generalised as an year round phenomenon. Of course localities which are influenced by seasonal variation in fresh water run-off, mainly during monsoon could be exceptions. In order...

Tropical Freshwater Biology

African Journals Online (AJOL)

Tropical Freshwater Biology promotes the publication of scientific contributions in the field of freshwater biology in the tropical and subtropical regions of the world. One issue is published annually but this number may be increased. Original research papers and short communications on any aspect of tropical freshwater ...

Quantifying tropical peatland dissolved organic carbon (DOC) using UV-visible spectroscopy.

Science.gov (United States)

Cook, Sarah; Peacock, Mike; Evans, Chris D; Page, Susan E; Whelan, Mick J; Gauci, Vincent; Kho, Lip Khoon

2017-05-15

UV-visible spectroscopy has been shown to be a useful technique for determining dissolved organic carbon (DOC) concentrations. However, at present we are unaware of any studies in the literature that have investigated the suitability of this approach for tropical DOC water samples from any tropical peatlands, although some work has been performed in other tropical environments. We used water samples from two oil palm estates in Sarawak, Malaysia to: i) investigate the suitability of both single and two-wavelength proxies for tropical DOC determination; ii) develop a calibration dataset and set of parameters to calculate DOC concentrations indirectly; iii) provide tropical researchers with guidance on the best spectrophotometric approaches to use in future analyses of DOC. Both single and two-wavelength model approaches performed well with no one model significantly outperforming the other. The predictive ability of the models suggests that UV-visible spectroscopy is both a viable and low cost method for rapidly analyzing DOC in water samples immediately post-collection, which can be important when working at remote field sites with access to only basic laboratory facilities. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.

Palaeo-precipitation is a major determinant of palm species richness patterns across Madagascar: a tropical biodiversity hotspot

Science.gov (United States)

Rakotoarinivo, Mijoro; Blach-Overgaard, Anne; Baker, William J.; Dransfield, John; Moat, Justin; Svenning, Jens-Christian

2013-01-01

The distribution of rainforest in many regions across the Earth was strongly affected by Pleistocene ice ages. However, the extent to which these dynamics are still important for modern-day biodiversity patterns within tropical biodiversity hotspots has not been assessed. We employ a comprehensive dataset of Madagascan palms (Arecaceae) and climate reconstructions from the last glacial maximum (LGM; 21 000 years ago) to assess the relative role of modern environment and LGM climate in explaining geographical species richness patterns in this major tropical biodiversity hotspot. We found that palaeoclimate exerted a strong influence on palm species richness patterns, with richness peaking in areas with higher LGM precipitation relative to present-day even after controlling for modern environment, in particular in northeastern Madagascar, consistent with the persistence of tropical rainforest during the LGM primarily in this region. Our results provide evidence that diversity patterns in the World's most biodiverse regions may be shaped by long-term climate history as well as contemporary environment. PMID:23427173

Assessing diversity and phytoremediation potential of seagrass in tropical region

Science.gov (United States)

Seagrass ecosystem is one of the most important resources in the coastal areas. Seagrasses support and provide habitats for many coastal organisms in tropical region. Seagrasses are specialized marine flowering plants that have adapted to the nearshore environment with heterogeneous landscape struct...

Applications of NASA TROPICS Data for Tropical Cyclone Analysis, Nowcasting, and Impacts

Science.gov (United States)

Zavodsky, B.; Dunion, J. P.; Blackwell, W. J.; Braun, S. A.; Green, D. S.; Velden, C.; Adler, R. F.; Cossuth, J.; Murray, J. J.; Brennan, M. J.

2017-12-01

The National Aeronautics and Space Administration (NASA) Time-Resolved Observations of Precipitation structure and storm Intensity with a Constellation of Smallsats (TROPICS) mission is a constellation of state-of-the-science observing platforms that will measure temperature and humidity soundings and precipitation with spatial resolution comparable to current operational passive microwave sounders but with unprecedented temporal resolution. TROPICS is a cost-capped ($30M) Venture-class mission funded by the NASA Earth Science Division. The mission is comprised of a constellation of 3 unit (3U) SmallSats, each hosting a 12-channel passive microwave spectrometer based on the Micro-sized Microwave Atmospheric Satellite 2 (MicroMAS-2) developed at MIT LL. TROPICS will provide imagery near 91 and 205 GHz, temperature sounding near 118 GHz, and moisture sounding near 183 GHz. Spatial resolution at nadir will be around 27 km for temperature and 17 km for moisture and precipitation. The swath width is approximately 2000 km. TROPICS enables temporal resolution similar to geostationary orbit but at a much lower cost, demonstrating a technology that could impact the design of future Earth-observing missions. The TROPICS satellites for the mission are slated for delivery to NASA in 2019 with potential launch opportunities in 2020. The primary mission objective of TROPICS is to relate temperature, humidity, and precipitation structure to the evolution of tropical cyclone (TC) intensity. This abstract summarizes the outcomes of the 1st TROPICS Applications Workshop, held from May 8-10, 2017 at the University of Miami. At this meeting, a series of presentations and breakout discussions in the topical areas of Tropical Cyclone Dynamics, Tropical Cyclone Analysis and Nowcasting, Tropical Cyclone Modeling and Data Assimilation, and Terrestrial Impacts were convened to identify applications of the mission data and to begin to establish a community of end-users who will be able to

Whole-ecosystem experimental manipulations of tropical forests

OpenAIRE

Fayle, Tom M; Turner, Edgar Clive; Basset, Yves; Ewers, Robert M; Reynolds, Glen; Novotny, Vojtech

2015-01-01

Tropical forests are highly diverse systems involving extraordinary numbers of interactions between species, with each species responding in a different way to the abiotic environment. Understanding how these systems function and predicting how they respond to anthropogenic global change is extremely challenging. We argue for the necessity of ‘whole-ecosystem’ experimental manipulations, in which the entire ecosystem is targeted, either to reveal the functioning of the...

Students' Perceptions of Computer-Based Learning Environments, Their Attitude towards Business Statistics, and Their Academic Achievement: Implications from a UK University

Science.gov (United States)

Nguyen, ThuyUyen H.; Charity, Ian; Robson, Andrew

2016-01-01

This study investigates students' perceptions of computer-based learning environments, their attitude towards business statistics, and their academic achievement in higher education. Guided by learning environments concepts and attitudinal theory, a theoretical model was proposed with two instruments, one for measuring the learning environment and…

Neglected tropical diseases

Directory of Open Access Journals (Sweden)

David Molyneux

2013-08-01

Full Text Available Seventeen neglected tropical diseases (NTDs have been identified by the World Health Organization (WHO. It is estimated that over 1 billion people are infected with NTDs, with a further 1 billion at risk. The majority of NTDs occur in the tropics and sub-tropics and have particular characteristics in common.

Factors Affecting Study-Related Burnout among Finnish University Students: Teaching-Learning Environment, Achievement Motivation and the Meaning of Life

Science.gov (United States)

Meriläinen, Matti

2014-01-01

This study of a large sample (n = 3035) examined relationships between study-related burnout and components of the teaching-learning environment, achievement motivation and the perceived meaning of life. The overall model, tested with structural equation modelling, revealed that the factor of the teaching-learning environment correlated with both…

210Pb sediment dating in coastal transition zones: tropical saltmarshes.

Science.gov (United States)

Ruiz-Fernandez, A. C.; Sanchez-Cabeza, J. A.; Carnero-Bravo, V.; Perez-Bernal, L. H.

2016-12-01

Sea level rise (SLR) is one of the climate change effects expected to have the largest impact on coastal environments. SLR rates are not uniform around the planet and, therefore, local and regional data and trends are needed for proper adaptation plans. As long term monitoring stations of SLR are very scarce in most of the world, SLR trends obtained from 210Pb-dated sediment cores from tropical saltmarshes have become a practical alternative to obtain SLR trends within the past century, under the assumption that these ecosystems accrete at a similar rate to SLR. However, tropical saltmarshes are challenging environments for 210Pb dating: they are regularly dry, intermittently covered by seawater only during the highest tides, and sedimentary records often reflect the transition between terrestrial and marine environments (e.g. changes in grain size distribution, organic matter content and elemental composition) with all these factors contributing for atypical 210Pb depth profiles. In addition, 137Cs, the chronostratigraphic marker most commonly used to corroborate 210Pb dating, fails to be preserved in the sedimentary record in tropical areas, owing to its solubility in marine waters, if at all detectable. The present study describes the challenges and proposed solutions for 210Pb dating saltmarsh sediment cores from two saltmarsh areas (southern Gulf of California and Yucatan Peninsula) including the use of plutonium isotopes for corroboration purposes. Acknowledgements: projects CONACYT CB2010/153492 and PDCPN201301/214349; UNAM PAPIIT-IN203313 and the PRODEP network "Aquatic contamination: levels and effects" (year 3).

Características do pelame de vacas Holandesas em ambiente tropical: um estudo genético e adaptativo Haircoat traits in Holstein cows in tropical environments: a genetic and adaptative study

Directory of Open Access Journals (Sweden)

Alex Sandro Campos Maia

2003-08-01

. These traits were measured in an area 20cm below the dorsal line in the center of the thorax, for the black as for the white haircoat. Hair samplings were performed with adapted pliers. The method of Restricted Maximum Likelihood (REML was used to estimate the variance and covariance components under the Animal model, the program used being the MTDFREML. The results showed that traits of black haircoat were different from that of the white haircoat, when the animals are breed in a tropical environment. Black haircoat was less dense, with shorter and ticker hair fibres in order to ease the heat dissipation, while the white haircoat was denser with longer hairs, which favored protection against direct solar radiation. The selection of predominantly black cows would be a good choice under the strong solar radiation in tropical environment, because the pigmented skin under this type coat. Such a selection could be easily performed considering the high heritability (h²=0.75 of the proportion of black coat, and must consider a less dense haircoat with short and tick hairs to help the dissipation sensible and latent heat.

Control of neglected tropical diseases needs a long-term commitment

Directory of Open Access Journals (Sweden)

Mubila Likezo

2010-10-01

Full Text Available Abstract Background Neglected tropical diseases are widespread, particularly in sub-Saharan Africa, affecting over 2 billion individuals. Control of these diseases has gathered pace in recent years, with increased levels of funding from a number of governmental or non-governmental donors. Focus has currently been on five major 'tool-ready' neglected tropical diseases (lymphatic filariasis, onchocerciasis, schistosomiasis, soil-transmitted helminthiasis and trachoma, using a package of integrated drug delivery according to the World Health Organization guidelines for preventive chemotherapy. Discussion Success in controlling these neglected tropical diseases has been achieved in a number of countries in recent history. Experience from these successes suggests that long-term sustainable control of these diseases requires: (1 a long-term commitment from a wider range of donors and from governments of endemic countries; (2 close partnerships of donors, World Health Organization, pharmaceutical industries, governments of endemic countries, communities, and non-governmental developmental organisations; (3 concerted action from more donor countries to provide the necessary funds, and from the endemic countries to work together to prevent cross-border disease transmission; (4 comprehensive control measures for certain diseases; and (5 strengthened primary healthcare systems as platforms for the national control programmes and capacity building through implementation of the programmes. Conclusions The current level of funding for the control of neglected tropical diseases has never been seen before, but it is still not enough to scale up to the 2 billion people in all endemic countries. While more donors are sought, the stakeholders must work in a coordinated and harmonised way to identify the priority areas and the best delivery approaches to use the current funds to the maximum effect. Case management and other necessary control measures should be

The ameliorative effect of ascorbic acid on the oxidative status, live weight and recovery rate in road transport stressed goats in a hot humid tropical environment.

Science.gov (United States)

Nwunuji, Tanko Polycarp; Mayowa, Opeyemi Onilude; Yusoff, Sabri Mohd; Bejo, Siti-Khairani; Salisi, Shahrom; Mohd, Effendy Abd Wahid

2014-05-01

The ameliorative effect of ascorbic acid (AA) on live weight following transportation is vital in animal husbandry. This study investigated the influence of AA on live weight, rectal temperature (rt), and oxidative status of transport stressed goats in a hot humid tropical environment. Twenty-four goats were divided into four groups, A, B, C and D of six animals each. Group A were administered AA 100 mg/kg intramuscularly 30 min prior to 3.5 h transportation. Group B was administered AA following transportation. Group C were transported but not administered AA as positive controls while group D were not transported but were administered normal saline as negative controls. Live weight, rt and blood samples were collected before, immediately post-transport (pt), 24 h, 3 days, 7 days and 10 days pt. Plasma was used for malondialdehyde (MDA) analysis while hemolysates were used for superoxide dismutase (SOD) analysis. There was minimal live weight loss in group A compared to groups B and C. Group A recorded reduced MDA activities and increased SOD activities compared to groups B and C which recorded significantly high MDA activities. This study revealed that AA administration ameliorated the stress responses induced by transportation in animals in hot humid tropical environments. The administration of AA to goats prior to transportation could ameliorate stress and enhance productivity. © 2014 Japanese Society of Animal Science.

Tweeting badges: user motivations for displaying achievement in publicly networked environments.

Science.gov (United States)

Kwon, K Hazel; Halavais, Alexander; Havener, Shannon

2015-02-01

Badge systems, a common mechanism for gamification on social media platforms, provide a way for users to present their knowledge or experience to others. This study aims to contribute to the understanding of why social media users publicize their achievements in the form of online badges. Five motivational factors for badge display in public networked environments are distinguished-self-efficacy, social incentives, networked support, passing time, and inattentive sharing-and it is suggested that different badge types are associated with different motivations. System developers are advised to consider these components in their designs, applying the elements most appropriate to the communities they serve. Comparing user motivations associated with badges shared across boundaries provides a better understanding of how online badges relate to the larger social media ecosystem.

Variability of radiatively forced diurnal cycle of intense convection in the tropical west pacific

Energy Technology Data Exchange (ETDEWEB)

Gray, W.M.; Sheaffer, J.D.; Thorson, W.B. [Colorado State Univ., Fort Collins, CO (United States)

1996-04-01

Strong differences occur in daytime versus nighttime (DVN) net radiative cooling in clear versus cloudy areas of the tropical atmosphere. Daytime average cooling is approximately -0.7{degrees}C/day, whereas nighttime net tropospheric cooling rates are about -1.5{degrees}C/day, an approximately two-to-one difference. The comparatively strong nocturnal cooling in clear areas gives rise to a diurnally varying vertical circulation and horizontal convergence cycle. Various manifestations of this cyclic process include the observed early morning heavy rainfall maxima over the tropical oceans. The radiatively driven DVN circulation appears to strongly modulate the resulting diurnal cycle of intense convection which creates the highest, coldest cloudiness over maritime tropical areas and is likely a fundamental mechanism governing both small and large scale dynamics over much of the tropical environment.

The impact of environmental inertial stability on the secondary circulation of axisymmetric tropical cyclones

Science.gov (United States)

O'Neill, M. E.; Chavas, D. R.

2017-12-01

In f-plane numerical simulations and analytical theory, tropical cyclones completely recycle their exhausted outflow air back into the boundary layer. This low-angular momentum air must experience cyclonic torque at the sea surface for cyclone to reach equilibrium. On Earth, however, it is not clear that tropical cyclones recycle all of the outflow air in a closed secondary circulation, and strong asymmetric outflow-jet interactions suggest that much of the air may be permanently evacuated from the storm over its lifetime. The fraction of outflow air that is returned to the near-storm boundary layer is in part a function of the environmental inertial stability, which controls the size and strength of the upper anticyclone. We run a suite of idealized axisymmetric tropical cyclone simulations at constant latitude while varying the outer domain's inertial stability profile. Fixing the latitude allows the gradient wind balance of the storm core to remain constant except for changes due to the far environment. By varying both the outer inertial stability and its location with respect to the Rossby radius of deformation, we show how the tropical cyclone's area-of-influence is controlled by the nature and strength of the upper anticyclone. Parcel tracking additionally demonstrates the likelihood of outflow air parcels to be quickly re-consumed by the secondary circulation as a function of inertial stability. These experiments demonstrate the sensitivity of the tropical cyclone's secondary circulation, typically assumed to be closed, to the dynamics of the far environment.

Adoption of Agroforestry Innovations in the Tropics: A Review

Science.gov (United States)

D. Evan Mercer

2004-01-01

The period since the early 1990s has witnessed an explosion of research on the adoption of agroforestry innovations in the tropics. Much of this work was motivated by a perceived gap between advances in agroforestry science and the success of agroforestry-based development programs and projects. Achieving the full promise of agroforestry requires a fundamental...

The Multiple Use of Tropical Forests by Indigenous Peoples in Mexico: a Case of Adaptive Management

Directory of Open Access Journals (Sweden)

Víctor M. Toledo

2003-12-01

Full Text Available The quest for an appropriate system of management for tropical ecosystems necessitates that ecologists consider the accumulated experiences of indigenous peoples in their long-term management of local resources, a subject of current ethnoecology. This paper provides data and empirical evidence of an indigenous multiple-use strategy (MUS of tropical forest management existing in Mexico, that can be considered a case of adaptive management. This conclusion is based on the observation that some indigenous communities avoid common modernization routes toward specialized, unsustainable, and ecologically disruptive systems of production, and yet probably achieve the most successful tropical forest utilization design, in terms of biodiversity conservation, resilience, and sustainability. This analysis relies on an exhaustive review of the literature and the authors' field research. Apparently, this MUS represents an endogenous reaction of indigenous communities to the intensification of natural resource use, responding to technological, demographic, cultural, and economic changes in the contemporary world. This transforms traditional shifting cultivators into multiple-use strategists. Based on a case study, three main features (biodiversity, resilience, and permanence considered relevant to achieving adaptive and sustainable management of tropical ecosystems are discussed.

Modelling nutrient management in tropical cropping systems

OpenAIRE

Delve, R. (ed.); Probert, M. (ed.)

2004-01-01

Metadata only record In tropical regions, organic materials are often more important than fertilizers in maintaining soil fertility, yet fertilizer recommendations and most crop models are unable to take account of the level and quality of organic inputs that farmers use. Computer simulation models, such as the Agricultural Production Systems Simulator (APSIM) developed by CSIRO and the Queensland Department of Primary Industries, have proven their value in many cropping environments. Thes...

The tropical lapse rate steepened during the Last Glacial Maximum

NARCIS (Netherlands)

Loomis, Shannon E; Russell, James M; Verschuren, Dirk; Morrill, Carrie; De Cort, Gijs; Sinninghe Damsté, Jaap S; Olago, Daniel; Eggermont, Hilde; Street-Perrott, F Alayne; Kelly, Meredith A

The gradient of air temperature with elevation (the temperature lapse rate) in the tropics is predicted to become less steep during the coming century as surface temperature rises, enhancing the threat of warming in high-mountain environments. However, the sensitivity of the lapse rate to climate

Impacts of energy utilization in a tropical environment

International Nuclear Information System (INIS)

Kleemann, M.; Penner, K.; Seele, U.

1992-01-01

The purpose of this paper is to present the approach and the interim results of the Indonesian-German scientific co-operation on environmental impacts of future energy utilization in Indonesia. The aim of the planning study is to provide decision support for Indonesian authorities in order to develop environmentally compatible energy supply strategies. The environmental problems will focus on the island of Java with a population density of more than 800 inhabitants/km 2 which might reach 1200 within the next 25 years. Due to the further economic growth and the population increase the energy consumption of the industry, the traffic, and the household sector will increase significantly. In particular the polluting coal utilization will grow overproportionally because of declining oil reserves. Additionally, the industrial development is concentrated on the island of Java which covers only 8% of the land area of the country. A serious pollution of the sensitive tropical ecosystems in the future would be the consequence of this unbalanced developments if no efforts are made to reduce the pollutant emissions. Even today the air quality has already reached critical levels in many parts of Java. 3 figs., 3 tabs

Evaluation of protective measures for tropical environments

International Nuclear Information System (INIS)

Silva, D. N. G.; Rochedo, E. R. R.; Wasserman, M. A. V.; Conti, L. F. C.

2012-01-01

Nuclear and radiological accidents have demonstrated the need for prior planning for exposure assessment as well as guidelines for the implementation of protection and remediation measures of contaminated areas. Typically, the description of the efficiency of the measures in the literature is associated with the reduction of the concentration of the environmental media where they are applied. In order to verify the efficiency related to the reduction in doses, some basic scenarios were established, taking into account aspects of a typical tropical climate, such as building materials (urban areas) and types of crops and farming practices, considering the seasonality and soil type typical of the southeastern region of Brazil. The Integrated System for Emergency (SIEM) program was used to perform the simulations. The results indicate that decision-making processes must be made in accordance with the actual conditions of contamination and use of the affected area. For rural areas, the effectiveness of measures depends on many factors specific to each site, such as seasonality, produced crops, diet habits and degree of subsistence on the items in the diet, which make it unfeasible to develop generic predefined scenarios. The criteria for classification of measurements were defined as: (i) the efficiency in reducing the doses in the first year, in which largest dose rates are observed; (ii) the efficiency in reducing the long-term dose, considering 50 y for adults and (iii) the effect of delay in implementation of the measures on the reduction of doses. (authors)

Evaluation of the results of the IAEA/FAO CRP on tropical transfer factors

International Nuclear Information System (INIS)

Twining, J.

1998-01-01

Future development of tropical countries will include nuclear power. This is particularly true following the recent attention given to the urgent need to reduce greenhouse gas emissions. From this, it is apparent that there is a need to have the ability to undertake dose assessments within tropical and sub-tropical regions. This includes knowledge of appropriate biological transfer factors for the region. However, most previous transfer factor studies were undertaken within temperate regions, predominantly in the Northern Hemisphere. Following a preliminary data survey, there was thus found to be a paucity of data for tropical and sub-tropical regions (excluding marine ecosystems). In an attempt to rectify this situation, the IAEA and FAO instigated a cooperative research program (CRP) entitled 'Transfer of radionuclides from air, soil and freshwater to the food chain of man in tropical and subtropical environments.' This paper is a synopsis of the findings of the three year CRP project. It is important to recognize that the data used in this presentation are derived from contributors and their colleagues in several countries. A list of chief investigators is given. Dr Martin Frissel, Secretary, European IUR, deserves a special mention for his collation of the CRP data. Some of his figures were used in the presentation or reproduced in this synopsis. The participants undertook regional literature and data surveys, field sampling and experimental investigations. The experimental studies were run by following, as closely as practicable, a suite of standard protocols that helped to reduce variability and errors. The experimental studies comprised two main groups: soil to plant, and: freshwater to fish. Quality assurance on analytical work was performed using intercomparison tests with standard reference materials. The reporting of data was also standardised to facilitate collation and subsequent multivariate statistical analysis. The statistical analysis of the entire

INTEGRATION OF PALSAR AND ASTER SATELLITE DATA FOR GEOLOGICAL MAPPING IN TROPICS

Directory of Open Access Journals (Sweden)

A. Beiranvand Pour

2015-10-01

Full Text Available This research investigates the integration of the Phased Array type L-band Synthetic Aperture Radar (PALSAR and the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER satellite data for geological mapping applications in tropical environments. The eastern part of the central belt of peninsular Malaysia has been investigated to identify structural features and mineral mapping using PALSAR and ASTER data. Adaptive local sigma and directional filters were applied to PALSAR data for detecting geological structure elements in the study area. The vegetation, mineralogic and lithologic indices for ASTER bands were tested in tropical climate. Lineaments (fault and fractures and curvilinear (anticline or syncline were detected using PALSAR fused image of directional filters (N-S, NE-SW, and NW-SE.Vegetation index image map show vegetation cover by fusing ASTER VNIR bands. High concentration of clay minerals zone was detected using fused image map derived from ASTER SWIR bands. Fusion of ASTER TIR bands produced image map of the lithological units. Results indicate that data integration and data fusion from PALSAR and ASTER sources enhanced information extraction for geological mapping in tropical environments.

Vaccines to combat the neglected tropical diseases

Science.gov (United States)

Bethony, Jeffrey M.; Cole, Rhea N.; Guo, Xiaoti; Kamhawi, Shaden; Lightowlers, Marshall W.; Loukas, Alex; Petri, William; Reed, Steven; Valenzuela, Jesus G.; Hotez, Peter J.

2012-01-01

Summary The neglected tropical diseases (NTDs) represent a group of parasitic and related infectious diseases such as amebiasis, Chagas disease, cysticercosis, echinococcosis, hookworm, leishmaniasis, and schistosomiasis. Together, these conditions are considered the most common infections in low- and middle-income countries, where they produce a level of global disability and human suffering equivalent to better known conditions such as human immunodeficiency virus/acquired immunodeficiency syndrome and malaria. Despite their global public health importance, progress on developing vaccines for NTD pathogens has lagged because of some key technical hurdles and the fact that these infections occur almost exclusively in the world’s poorest people living below the World Bank poverty line. In the absence of financial incentives for new products, the multinational pharmaceutical companies have not embarked on substantive research and development programs for the neglected tropical disease vaccines. Here, we review the current status of scientific and technical progress in the development of new neglected tropical disease vaccines, highlighting the successes that have been achieved (cysticercosis and echinococcosis) and identifying the challenges and opportunities for development of new vaccines for NTDs. Also highlighted are the contributions being made by non-profit product development partnerships that are working to overcome some of the economic challenges in vaccine manufacture, clinical testing, and global access. PMID:21198676

Sorption of pesticides in tropical and temperate soils from Australia and the Philippines.

Science.gov (United States)

Oliver, Danielle P; Kookana, Rai S; Quintana, Belen

2005-08-10

The sorption behavior of diuron, imidacloprid, and thiacloprid was investigated using 22 soils collected in triplicate from temperate environments in Australia and tropical environments in Australia and the Philippines. Within the temperate environment in Australia, the soils were selected from a range of land uses. The average KOC values (L/kg) for imidacloprid were 326, 322, and 336; for thiacloprid, the values were 915, 743, and 842; and for diuron, the values were 579, 536, and 618 for the Ord (tropical), Mt. Lofty (temperate), and Philippines (tropical) soils, respectively. For all soils, the sorption coefficients decreased in the following order: thiacloprid > diuron > imidacloprid. There were no significant differences in sorption behavior between the tropical soils from the Philippines and the temperate soils from Australia. Sorption was also not significantly related with soil characteristics, namely, organic carbon (OC) content, clay content, and pH, for any of the three chemicals studied. When the data were sorted into separate land uses, the sorption of all three chemicals was highly correlated (P soils from the Philippines. Sorption coefficients for all three chemicals were highly correlated with OC in temperate, native soils only when one extreme value was removed. The relationships between sorption of all three chemicals and OC in temperate, pasture soils were best described by a polynomial. Sorption coefficients for imidacloprid and thiacloprid determined in the temperate pasture soils remained fairly consistent as the OC content increased from 3.3 to 5.3%, indicating that, although the total OC in the pasture soils was increasing, the component of OC involved with sorption of these two compounds may have been remaining constant. This study demonstrated that the origin of the soils (i.e., temperate vs tropical) had no significant effect on the sorption behavior, but in some cases, land use significantly affected the sorption behavior of the three

Socializing the coast: Engaging the social science of tropical coastal research

Science.gov (United States)

Spalding, Ana K.; Biedenweg, Kelly

2017-03-01

The broad scale and rapid rate of change in the global environment is causing some of the world's most challenging problems, such as habitat degradation, loss of biodiversity, and food insecurity. These problems are especially pressing in coastal environments in the tropics, resulting in significant impacts on human wellbeing and ecological systems across the globe. The underlying causes of marine and coastal environmental change are both anthropogenic and natural; and, while it is difficult to parse out causal linkages as either exclusively human or naturally occurring, feedbacks between drivers only exacerbate the issues. Increasingly, scholars are turning to integrated research efforts, whereby multiple disciplines are used to answer pressing questions about and find solutions for the sustainability of human life and natural ecosystems across the coastal tropics. This article leverages the recent wave of interdisciplinary research to explore the various ways in which the social sciences have successfully contributed to a more complete understanding of coastal systems across the tropics. It also identifies opportunities for research that move beyond single disciplinary approaches to coastal science. The concluding discussion suggests social science knowledge areas that are underutilized in coastal research and provides suggestions for increasing the incorporation of social science in coastal research programs.

Multiple antibiotic resistant Escherichia coli from a tropical rain forest stream

Energy Technology Data Exchange (ETDEWEB)

Carrasco, C.E.; Alvarez, H.J.; Ortiz, N.; Bisbal, M.; Arias, W.; Baerga, C. [Univ. of Puerto Rico, Rio Piedras (Puerto Rico). Dept. of Biology; Hazen, T.C. [E.I. DuPont de Nemours and Co., Aiken, SC (United States). Savannah River Lab.

1988-12-31

High densities of fecal coliforms were obtained from a pristine site and sewage contaminated site in a tropical rain forest watershed in Puerto Rico. Confirmation of fecal coliform isolates as Escherichia coli was significantly lower than for temperate waters. Antibiotic resistance and multiple antibiotic resistance were common for isolates at both sites; however, the site receiving sewage effluent had a greater proportion of multiple antibiotic resistant isolates. R. plasmids were recovered from 4 MAR isolates, 2 from each site. All recovered plasmids were approximately 1 kilobase. The recovered plasmid were also capable of transforming E. coli HB101 in vitro. The high concentrations of enterobacteriaceae, small R-plasmid size, R-plasmid transformability, and long term survival of fecal origin bacteria in tropical freshwater environments give increasing importance to adequate sewage treatment, and better indicator monitoring methods for tropical areas.

Aboveground tree growth varies with belowground carbon allocation in a tropical rainforest environment

Science.gov (United States)

J.W. Raich; D.A. Clark; L. Schwendenmann; Tana Wood

2014-01-01

Young secondary forests and plantations in the moist tropics often have rapid rates of biomass accumulation and thus sequester large amounts of carbon. Here, we compare results from mature forest and nearby 15–20 year old tree plantations in lowland Costa Rica to evaluate differences in allocation of carbon to aboveground production and root systems. We found that the...

Upscaling species richness and abundances in tropical forests.

Science.gov (United States)

Tovo, Anna; Suweis, Samir; Formentin, Marco; Favretti, Marco; Volkov, Igor; Banavar, Jayanth R; Azaele, Sandro; Maritan, Amos

2017-10-01

The quantification of tropical tree biodiversity worldwide remains an open and challenging problem. More than two-fifths of the number of worldwide trees can be found either in tropical or in subtropical forests, but only ≈0.000067% of species identities are known. We introduce an analytical framework that provides robust and accurate estimates of species richness and abundances in biodiversity-rich ecosystems, as confirmed by tests performed on both in silico-generated and real forests. Our analysis shows that the approach outperforms other methods. In particular, we find that upscaling methods based on the log-series species distribution systematically overestimate the number of species and abundances of the rare species. We finally apply our new framework on 15 empirical tropical forest plots and quantify the minimum percentage cover that should be sampled to achieve a given average confidence interval in the upscaled estimate of biodiversity. Our theoretical framework confirms that the forests studied are comprised of a large number of rare or hyper-rare species. This is a signature of critical-like behavior of species-rich ecosystems and can provide a buffer against extinction.

Development of a modular streamflow model to quantify runoff contributions from different land uses in tropical urban environments using Genetic Programming

Science.gov (United States)

Meshgi, Ali; Schmitter, Petra; Chui, Ting Fong May; Babovic, Vladan

2015-06-01

The decrease of pervious areas during urbanization has severely altered the hydrological cycle, diminishing infiltration and therefore sub-surface flows during rainfall events, and further increasing peak discharges in urban drainage infrastructure. Designing appropriate waster sensitive infrastructure that reduces peak discharges requires a better understanding of land use specific contributions towards surface and sub-surface processes. However, to date, such understanding in tropical urban environments is still limited. On the other hand, the rainfall-runoff process in tropical urban systems experiences a high degree of non-linearity and heterogeneity. Therefore, this study used Genetic Programming to establish a physically interpretable modular model consisting of two sub-models: (i) a baseflow module and (ii) a quick flow module to simulate the two hydrograph flow components. The relationship between the input variables in the model (i.e. meteorological data and catchment initial conditions) and its overall structure can be explained in terms of catchment hydrological processes. Therefore, the model is a partial greying of what is often a black-box approach in catchment modelling. The model was further generalized to the sub-catchments of the main catchment, extending the potential for more widespread applications. Subsequently, this study used the modular model to predict both flow components of events as well as time series, and applied optimization techniques to estimate the contributions of various land uses (i.e. impervious, steep grassland, grassland on mild slope, mixed grasses and trees and relatively natural vegetation) towards baseflow and quickflow in tropical urban systems. The sub-catchment containing the highest portion of impervious surfaces (40% of the area) contributed the least towards the baseflow (6.3%) while the sub-catchment covered with 87% of relatively natural vegetation contributed the most (34.9%). The results from the quickflow

Desorption isotherms of heavy (AZOBE, EBONY) and light heavyweight tropical woods (IROKO, SAPELLI) of Cameroon

Science.gov (United States)

Nsouandélé, J. L.; Tamba, J. G.; Bonoma, B.

2018-04-01

This work is centered on the study of the desorption isotherms of heavy (Azobe, Ebony) and heavyweight (Iroko, Sapelli) tropical woods, which contribute in the determination of drying and storage of tropical plank woods. Desorption isotherms of tropical woods were experimentally determined under different temperatures in this study using the gravimetric method. The determination of Henderson's model isotherms parameters of desorption were obtained for temperatures of 20 °C, 30 °C, 40 °C, and 50 °C. The mean relative deviation between theoretical and experimental moisture contents was calculated and fitted well with the desorption models of tropical woods. We noticed that Henderson models fitted much better with experimental ones for 95% of relative humidity. The sigmoid shapes of results are satisfactory. Hysteresis phenomenon was observed for desorption isotherms of heavy (Azobe, Ebony) and heavyweight (Iroko, Sapelli) tropical woods. Results showed the difference between the stability and use of heavy and heavyweight tropical wood. These results help in the estimation of water content at equilibrium of tropical woods in relative humidity from experimented ones. Hygroscopic equilibrium humidity of heavy tropical woods varied between 0% and 50% while those of heavyweight varied between 0% and 25%. Therefore, these woods can be used in an opened environment; woodwork and decoration.

Evolution of the Tropical Cyclone Integrated Data Exchange And Analysis System (TC-IDEAS)

Science.gov (United States)

Turk, J.; Chao, Y.; Haddad, Z.; Hristova-Veleva, S.; Knosp, B.; Lambrigtsen, B.; Li, P.; Licata, S.; Poulsen, W.; Su, H.;

A Study of the Relationship between Academic Achievement Motivation and Home Environment among Standard Eight Pupils

Science.gov (United States)

Muola, J. M.

2010-01-01

The objective of this study was to investigate the relationship between academic achievement motivation and home environment among standard eight pupils. The study was carried out on 235 standard eight Kenyan pupils from six urban and rural primary schools randomly selected from Machakos district. Their age ranged between 13 and 17 years. Two…

[Biomedical research in Revista de Biologia Tropical].

Science.gov (United States)

Gutiérrez, José María

2002-01-01

The contributions published in Revista de Biología Tropical in the area of Biomedical Sciences are reviewed in terms of number of contributions and scope of research subjects. Biomedical Sciences, particularly Parasitology and Microbiology, constituted the predominant subject in the Revista during the first decade, reflecting the intense research environment at the School of Microbiology of the University of Costa Rica and at Hospital San Juan de Dios. The relative weight of Biomedicine in the following decades diminished, due to the outstanding increment in publications in Biological Sciences; however, the absolute number of contributions in Biomedical Sciences remained constant throughout the last decades, with around 80 contributions per decade. In spite of the predominance of Parasitology as the main biomedical subject, the last decades have witnessed the emergence of new areas of interest in the Revista, such as Pharmacology of natural products, Toxinology, especially related to snake venoms, and Human Genetics. This retrospective analysis evidences that Biomedical Sciences, particularly those related to Tropical Medicine, were a fundamental component during the first years of Revista de Biología Tropical, and have maintained a significant presence in the scientific output of this journal, the most relevant scientific publication in biological sciences in Central America.

The effect of β-FeOOH on the corrosion behavior of low carbon steel exposed in tropic marine environment

International Nuclear Information System (INIS)

Ma Yuantai; Li Ying; Wang Fuhui

2008-01-01

The atmospheric corrosion performance of carbon steel exposed in Wanning area, which located in the south part of China with tropic marine environment characters, was studied at different exposure periods (up to 2 years). To investigate the effect of β-FeOOH on the corrosion behavior of carbon steel in high chloride ion environment, rust layer was analyzed by using infrared spectroscopy, scanning electron microscope, X-ray diffraction, and the rusted steel was measured by electrochemical impedance spectroscopy method. The weight loss test indicated that the corrosion rate of carbon steel sharply increased during 6 months' exposure and gradually reduced after longer exposure. The results of rust analysis revealed that the underlying corrosion performance of the carbon steel was dependent on the inherent properties of the rust layers formed under different conditions such as composition and structure. Among all the iron oxide, β-FeOOH exerted significant influence. The presence of a monolayer of the rust as well as β-FeOOH accelerated the corrosion process during the initial exposure stage. EIS data implied that β-FeOOH in the inner layer was gradually consumed and transformed to γ-Fe 2 O 3 in the wet-dry cycle, which was beneficial to protect the substrate and reduced the corrosion rate

The Effect of Integrating Movement into the Learning Environment of Kindergarten Children on Their Academic Achievements

Science.gov (United States)

Shoval, Ella; Sharir, Tal; Arnon, Michal; Tenenbaum, Gershon

2018-01-01

The aim of this study was to test the notion that integrating movement into the learning environment contributes to the academic achievements of kindergarten students. One hundred and sixty 4-6 year-old kindergarten students participated in the study for 145 days, which included pre- and post-intervention tests in language, mathematics, and…

World bank and the environment. Progress report

International Nuclear Information System (INIS)

1991-01-01

The second annual report describes specific environmental strategies and environmental lending in the Bank's four operational regions: Africa; Asia; Europe, Middle East, and North Africa; and Latin America and the Caribbean. It details the Bank's progress in eight environmental categories: energy and the environment, pollution, urban environment, water resources management, forest and land management, social and cultural, environmental economics, and the global environment. One chapter is devoted exclusively to tropical forests, studying ways in which the Bank is dealing with deforestation as a part of the constant review of its forest policies. Suggestions are made for decreasing the degradation of tropical forests while meeting demands for forest products. This chapter reflects a shift in Bank emphasis from commercial ventures to conservation measures. The publication reports on other initiatives by the Bank during fiscal 1991, including the launching of the Global Environment Facility (GEF)--a pilot program to oversee reduction of global warming, preservation of biological diversity, protection of international waters, and prevention of ozone depletion

Involvement of Student Teachers and Pupils in Designing and Manipulating Virtual Learning Environments Impacts Reading Achievements

Directory of Open Access Journals (Sweden)

Esther Zaretsky

2012-04-01

Full Text Available The research is aimed at investigating the involvement of student teachers and pupils in designing and manipulating virtual learning environment and its impact on reading achievements through action research. In order to understand the connection between the real and virtual worlds, the design of such simulations is based on applying the virtual environment to the real world as much as possible. The objects were taken from the pupils’ everyday environment and unique motivation. The researcher taught the method to 30 student teachers. Such procedures were held among different populations. The findings showed that as the student teachers practiced the simulation design through the PowerPoint Software, it became clear to them how the computer can be implemented in their practical work. Consequently, their presentations became highly animated, and applied to the pupils

Rural Junior Secondary School Students' Perceptions of Classroom Learning Environments and Their Attitude and Achievement in Mathematics in West China

Science.gov (United States)

Yang, Xinrong

2015-01-01

This paper reports findings from a survey of how rural junior secondary school students in the western part of China perceive their mathematics classroom learning environments and associations of learning environment with their attitudes toward mathematics and mathematics achievement. Using adaptations of the widely-used What Is Happening In this…

The remote, the mouse, and the no. 2 pencil: the household media environment and academic achievement among third grade students.

Science.gov (United States)

Borzekowski, Dina L G; Robinson, Thomas N

2005-07-01

Media can influence aspects of a child's physical, social, and cognitive development; however, the associations between a child's household media environment, media use, and academic achievement have yet to be determined. To examine relationships among a child's household media environment, media use, and academic achievement. During a single academic year, data were collected through classroom surveys and telephone interviews from an ethnically diverse sample of third grade students and their parents from 6 northern California public elementary schools. The majority of our analyses derive from spring 2000 data, including academic achievement assessed through the mathematics, reading, and language arts sections of the Stanford Achievement Test. We fit linear regression models to determine the associations between variations in household media and performance on the standardized tests, adjusting for demographic and media use variables. The household media environment is significantly associated with students' performance on the standardized tests. It was found that having a bedroom television set was significantly and negatively associated with students' test scores, while home computer access and use were positively associated with the scores. Regression models significantly predicted up to 24% of the variation in the scores. Absence of a bedroom television combined with access to a home computer was consistently associated with the highest standardized test scores. This study adds to the growing literature reporting that having a bedroom television set may be detrimental to young elementary school children. It also suggests that having and using a home computer may be associated with better academic achievement.

The Effects of Digital Storytelling on Student Achievement, Social Presence, and Attitude in Online Collaborative Learning Environments

Science.gov (United States)

Nam, Chang Woo

2017-01-01

This study investigated the effects of digital storytelling on student achievement, social presence, and attitude in online collaborative learning environments. Students in one middle school course were randomly assigned to one of the two treatment groups after they received initial general instruction regarding teamwork skills. The "digital…

Hygroscopical behaviour of basic electrodes in a tropical humid climate. Comportamiento microscopico de ciertos electrodos revistidos de caracter basico en clima tropical humedo

Energy Technology Data Exchange (ETDEWEB)

Valencia, E.; Galeano, N.J.

1993-01-01

The study of the wetting kynetics of basic electrodes in a tropical humid climate is very important since the water contained in them is the main source for the atomic hydrogen absorbed by the fused metal during electric arc welding. It is also the origin of multiple defects in the added metal. A calculating method is established for evaluating the kynetics of wetness incorporation to the coating of basic electrodes exposed to a humid tropical climate. The method is based on the Fick's diffusion equation for both adequate system geometry and boundary conditions, which allows the evaluation of the effective diffusion coefficient and critical times of exposure to the different environments, along with the packing and storage conditions of electrodes. (Author)

Hygroscopical behaviour of basic electrodes in a tropical humid climate. Comportamiento microscopico de ciertos electrodos revistidos de caracter basico en clima tropical humedo

Energy Technology Data Exchange (ETDEWEB)

Valencia, E; Galeano, N J

1993-01-01

The study of the wetting kynetics of basic electrodes in a tropical humid climate is very important since the water contained in them is the main source for the atomic hydrogen absorbed by the fused metal during electric arc welding. It is also the origin of multiple defects in the added metal. A calculating method is established for evaluating the kynetics of wetness incorporation to the coating of basic electrodes exposed to a humid tropical climate. The method is based on the Fick's diffusion equation for both adequate system geometry and boundary conditions, which allows the evaluation of the effective diffusion coefficient and critical times of exposure to the different environments, along with the packing and storage conditions of electrodes. (Author)

Temperate radiations and dying embers of a tropical past: the diversification of Viburnum.

Science.gov (United States)

Spriggs, Elizabeth L; Clement, Wendy L; Sweeney, Patrick W; Madriñán, Santiago; Edwards, Erika J; Donoghue, Michael J

2015-07-01

We used a near-complete phylogeny for the angiosperm clade Viburnum to assess lineage diversification rates, and to examine possible morphological and ecological factors driving radiations. Maximum-likelihood and Bayesian approaches identified shifts in diversification rate and possible links to character evolution. We inferred the ancestral environment for Viburnum and changes in diversification dynamics associated with subsequent biome shifts. Viburnum probably diversified in tropical forests of Southeast Asia in the Eocene, with three subsequent radiations in temperate clades during the Miocene. Four traits (purple fruits, extrafloral nectaries, bud scales and toothed leaves) were statistically associated with higher rates of diversification. However, we argue that these traits are unlikely to be driving diversification directly. Instead, two radiations were associated with the occupation of mountainous regions and a third with repeated shifts between colder and warmer temperate forests. Early-branching depauperate lineages imply that the rare lowland tropical species are 'dying embers' of once more diverse lineages; net diversification rates in Viburnum likely decreased in these tropical environments after the Oligocene. We suggest that 'taxon pulse' dynamics might characterize other temperate plant lineages. © 2015 The Authors. New Phytologist © 2015 New Phytologist Trust.

Modelling of Box Type Solar Cooker Performance in a Tropical ...

African Journals Online (AJOL)

Thermal performance model of box type solar cooker with loaded water is presented. The model was developed using the method of Funk to estimate cooking power in terms of climatic and design parameters for box type solar cooker in a tropical environment. Coefficients for each term used in the model were determined ...

Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.

Science.gov (United States)

Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B

2014-01-01

In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species.

Cellular metabolic rate is influenced by life-history traits in tropical and temperate birds.

Directory of Open Access Journals (Sweden)

Ana Gabriela Jimenez

Full Text Available In general, tropical birds have a "slow pace of life," lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR, proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR], using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal's life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species.

Spatial Patterns in Water Quality Changes during Dredging in Tropical Environments

Science.gov (United States)

Fisher, Rebecca; Stark, Clair; Ridd, Peter; Jones, Ross

2015-01-01

Dredging poses a potential risk to tropical ecosystems, especially in turbidity-sensitive environments such as coral reefs, filter feeding communities and seagrasses. There is little detailed observational time-series data on the spatial effects of dredging on turbidity and light and defining likely footprints is a fundamental task for impact prediction, the EIA process, and for designing monitoring projects when dredging is underway. It is also important for public perception of risks associated with dredging. Using an extensive collection of in situ water quality data (73 sites) from three recent large scale capital dredging programs in Australia, and which included extensive pre-dredging baseline data, we describe relationships with distance from dredging for a range of water quality metrics. Using a criterion to define a zone of potential impact of where the water quality value exceeds the 80th percentile of the baseline value for turbidity-based metrics or the 20th percentile for the light based metrics, effects were observed predominantly up to three km from dredging, but in one instance up to nearly 20 km. This upper (~20 km) limit was unusual and caused by a local oceanographic feature of consistent unidirectional flow during the project. Water quality loggers were located along the principal axis of this flow (from 200 m to 30 km) and provided the opportunity to develop a matrix of exposure based on running means calculated across multiple time periods (from hours to one month) and distance from the dredging, and summarized across a broad range of percentile values. This information can be used to more formally develop water quality thresholds for benthic organisms, such as corals, filter-feeders (e.g. sponges) and seagrasses in future laboratory- and field-based studies using environmentally realistic and relevant exposure scenarios, that may be used to further refine distance based analyses of impact, potentially further reducing the size of the dredging

Spatial Patterns in Water Quality Changes during Dredging in Tropical Environments.

Science.gov (United States)

Fisher, Rebecca; Stark, Clair; Ridd, Peter; Jones, Ross

2015-01-01

Dredging poses a potential risk to tropical ecosystems, especially in turbidity-sensitive environments such as coral reefs, filter feeding communities and seagrasses. There is little detailed observational time-series data on the spatial effects of dredging on turbidity and light and defining likely footprints is a fundamental task for impact prediction, the EIA process, and for designing monitoring projects when dredging is underway. It is also important for public perception of risks associated with dredging. Using an extensive collection of in situ water quality data (73 sites) from three recent large scale capital dredging programs in Australia, and which included extensive pre-dredging baseline data, we describe relationships with distance from dredging for a range of water quality metrics. Using a criterion to define a zone of potential impact of where the water quality value exceeds the 80th percentile of the baseline value for turbidity-based metrics or the 20th percentile for the light based metrics, effects were observed predominantly up to three km from dredging, but in one instance up to nearly 20 km. This upper (~20 km) limit was unusual and caused by a local oceanographic feature of consistent unidirectional flow during the project. Water quality loggers were located along the principal axis of this flow (from 200 m to 30 km) and provided the opportunity to develop a matrix of exposure based on running means calculated across multiple time periods (from hours to one month) and distance from the dredging, and summarized across a broad range of percentile values. This information can be used to more formally develop water quality thresholds for benthic organisms, such as corals, filter-feeders (e.g. sponges) and seagrasses in future laboratory- and field-based studies using environmentally realistic and relevant exposure scenarios, that may be used to further refine distance based analyses of impact, potentially further reducing the size of the dredging

Tropical coral reef habitat in a geoengineered, high-CO2 world

Science.gov (United States)

Couce, E.; Irvine, P. J.; Gregorie, L. J.; Ridgwell, A.; Hendy, E. J.

2013-05-01

Continued anthropogenic CO2 emissions are expected to impact tropical coral reefs by further raising sea surface temperatures (SST) and intensifying ocean acidification (OA). Although geoengineering by means of solar radiation management (SRM) may mitigate temperature increases, OA will persist, raising important questions regarding the impact of different stressor combinations. We apply statistical Bioclimatic Envelope Models to project changes in shallow water tropical coral reef habitat as a single niche (without resolving biodiversity or community composition) under various representative concentration pathway and SRM scenarios, until 2070. We predict substantial reductions in habitat suitability centered on the Indo-Pacific Warm Pool under net anthropogenic radiative forcing of ≥3.0 W/m2. The near-term dominant risk to coral reefs is increasing SSTs; below 3 W/m2 reasonably favorable conditions are maintained, even when achieved by SRM with persisting OA. "Optimal" mitigation occurs at 1.5 W/m2 because tropical SSTs overcool in a fully geoengineered (i.e., preindustrial global mean temperature) world.

A Review of Heat Transfer in Terraced Houses of Tropical Climate

Directory of Open Access Journals (Sweden)

Azzmi Norazura Mizal

2014-01-01

Full Text Available Heat is the process of energy circulation and replacement of air from hot to cold. In tropical climates, more heat is received because of the location of Malaysia of the equatorial line. Excessive heat in buildings causes discomfort to the occupants in tropical climate. Tropical rainforest climate receives higher solar radiation and terrestrial radiation reaching the building envelopes contributes to this problem. The design of the building should be more concern on reducing this heat. This paper provides a review of heat contribution in a terraced house indoor environment for tropical climate. A good comfortable home is part of the sustainable development agenda to improve the quality of life. Terraced houses are the most living quarters in mass living scheme for urban areas. The incoming solar energy from the sun into the building surface cannot be changed, therefore a consideration of passive building design need to be applied in terraced house design. Data collection gathered from this literature survey will assist to identify problems of discomfort occupant. This strategy would assist in improving the building industry in promoting sustainable development in Malaysia.

Home Environment, Self-Concept and Urban Student Achievement: A Bibliography and Review of Research. NJ Urban Education Research Reports No. 5.

Science.gov (United States)

Shapiro, Carol; Bloom, Joel S.

This review analyzes recent research on student personality, social and home environment, and the influence of these factors on academic achievement, particularly among minority and disadvantaged students. Several factors which purportedly affect student achievement and which are examined in the review include: (1) socioeconomic status and its…

Proxies of Tropical Cyclone Isotope Spikes in Precipitation: Landfall Site Selection

Science.gov (United States)

Lawrence, J. R.; Maddocks, R.

2011-12-01

The human experience of climate change is not one of gradual changes in seasonal or yearly changes in temperature or rainfall. Despite that most paleoclimatic reconstructions attempt to provide just such information. Humans experience climate change on much shorter time scales. We remember hurricanes, weeks of drought or overwhelming rainy periods. Tropical cyclones produce very low isotope ratios in both rainfall and in atmospheric water vapor. Thus, climate proxies that potentially record these low isotope ratios offer the most concrete record of climate change to which humans can relate. The oxygen isotopic composition of tropical cyclone rainfall has the potential to be recorded in fresh water carbonate fossil material, cave deposits and corals. The hydrogen isotopic composition of tropical cyclone rainfall has the potential to be recorded in tree ring cellulose and organic matter in fresh water bodies. The Class of carbonate organisms known as Ostracoda form their carapaces very rapidly. Thus fresh water ephemeral ponds in the subtropics are ideal locations for isotopic studies because they commonly are totally dry when tropical cyclones make landfall. The other proxies suffer primarily from a dilution effect. The water from tropical cyclones is mixed with pre-existing water. In cave deposits tropical cyclone rains mix with soil and ground waters. In the near shore coral environment the rain mixes with seawater. For tree rings there are three sources of water: soil water, atmospheric water vapor that exchanges with leaf water and tropical cyclone rain. In lakes because of their large size rainfall runoff mixes with ground water and preexisting water in the lake. A region that shows considerable promise is Texas / Northeast Mexico. In a study of surface waters that developed from the passage of Tropical Storm Allison (2001) in SE Texas both the pond water and Ostracoda that bloomed recorded the low oxygen isotope signal of that storm (Lawrence et al, 2008). In

Isolation of naphthalene-degrading bacteria from tropical marine sediments

International Nuclear Information System (INIS)

Zhuang, W.-Q.; Tay, J.-H.; Maszenan, A.M.; Tay, S.T.-L.

2003-01-01

Oil pollution is a major environmental concern in many countries, and this has led to a concerted effort in studying the feasibility of using oil-degrading bacteria for bioremediation. Although many oil-degrading bacteria have been isolated from different environments, environmental conditions can impose a selection pressure on the types of bacteria that can reside in a particular environment. This study reports the successful isolation of two indigenous naphthalene-degrading bacteria from oil-contaminated tropical marine sediments by enrichment culture. Strains MN-005 and MN-006 were characterized using an extensive range of biochemical tests. The 16S ribosomal deoxyribonucleic acid (rDNA) sequence analysis was also performed for the two strains. Their naphthalene degradation capabilities were determined using gas chromatography and DAPI counting of bacterial cells. Strains MN-005 and MN-006 are phenotypically and phylogenetically different from each other, and belong to the genera Staphylococcus and Micrococcus, respectively. Strains MN-005 and MN-006 has maximal specific growth rates (μ max ) of 0.082±0.008 and 0.30±0.02 per hour, respectively, and half-saturation constants (K s ) of 0.79±0.10 and 2.52±0.32 mg per litre, respectively. These physiological and growth studies are useful in assessing the potential of these indigenous isolates for in situ or ex situ naphthalene pollutant bioremediation in tropical marine environments. (author)

The tropical diabetic hand syndrome: a surgical perspective.

Science.gov (United States)

Nthumba, Peter; Cavadas, Pedro C; Landin, Luis

2013-01-01

Tropical diabetic hand syndrome (TDHS) is an aggressive type of hand sepsis that results in significant morbidity and mortality among patients with diabetes in the tropics. This study set out to establish a protocol for the holistic management of TDHS to improve digit/hand salvage and function at AIC Kijabe Hospital. This prospective study examined the following demographics of patients presenting to the authors institution between October 2009 and September 2010 with TDHS: their sex, age, comorbidities, length of in-hospital stay, surgical and medical treatment, total cost of treatment, and immediate postdischarge outcomes. A total of 10 patients (3 men and 7 women) were presented with TDHS during the study period. Surgical procedures included a thorough debridement of the hand at initial presentation, followed by procedures aimed at preserving length and hand function, with digit or hand amputation when there was no possibility of salvage. Three hands were salvaged, without the need for an amputation; 2 of these, however, developed severe stiffness with resultant poor function. Fifty percent of the patients developed considerable disability; 3 of these patients had disabilities of the arm, shoulder, and hand, (DASH) scores of >90 at 6 months after treatment. TDHS appears to be more aggressive in some patients than in others; a multidisciplinary approach, with early involvement of the surgical team, and a radical surgical debridement are essential to improved outcomes. Although the goal of medical treatment (ie, glycemic control) is simple and easily achieved, surgical goals (salvage of limb or life, preservation of hand function) are more complex, costly, and difficult to achieve. Educating health care workers, diabetic patients, and their relatives on hand care is an important preventive measure. Diligence in taking antidiabetic medicine, early presentation, and appropriate care of TDHS are required for meaningful improvement in outcomes of patients with

Tropical Peatland Geomorphology and Hydrology

Science.gov (United States)

Cobb, A.; Harvey, C. F.

2017-12-01

Tropical peatlands cover many low-lying areas in the tropics. In tropical peatlands, a feedback between hydrology, landscape morphology, and carbon storage causes waterlogged organic matter to accumulate into gently mounded land forms called peat domes over thousands of years. Peat domes have a stable morphology in which peat production is balanced by loss and net precipitation is balanced by lateral flow, creating a link between peatland morphology, rainfall patterns and drainage networks. We show how landscape morphology can be used to make inferences about hydrologic processes in tropical peatlands. In particular, we show that approaches using simple storage-discharge relationships for catchments are especially well suited to tropical peatlands, allowing river forecasting based on peatland morphology in catchments with tropical peatland subcatchments.

Conceptual differences between the bioclimatic urbanism for Europe and for the tropical humid climate

Energy Technology Data Exchange (ETDEWEB)

Corbella, O.D.; Magalhaes, M.A.A.A. [Faculdade de Arquitetura e Urbanismo, Universidade Federal do Rio de Janeiro, Rio de Janeiro (Brazil)

2008-05-15

This article makes part of a series of conceptual papers to continue the discussion about how architecture and urbanism interact with climate, in tropical regions. Students engaged in normal courses of architecture in tropical regions, particularly in South America, develop their knowledge based on concepts generated in the developed countries - usually related to cold environments. Consequently, these students acquire wrong ideas about urban design of open spaces. Integrating urbanism and climate in tropical countries is still very incipient as an approach and many lecturers reject it, since they prefer to continue with a more formal one, dictated by most of the dominant countries. The herein paper underlines several different concepts and perspectives that separate the two conceptions, leading to a reflection about the subject. (author)

Inter-cohort growth for three tropical resources: tilapia, octopus and lobster.

Science.gov (United States)

Velázquez-Abunader, Iván; Gómez-Muñoz, Victor Manuel; Salas, Silvia; Ruiz-Velazco, Javier M J

2015-09-01

Growth parameters are an important component for the stock assessment of exploited aquatic species. However, it is often difficult to apply direct methods to estimate growth and to analyse the differences between males and females, particularly in tropical areas. The objective of this study was to analyse the inter-cohort growth of three tropical resources and discuss the possible fisheries management implications. A simple method was used to compare individual growth curves obtained from length frequency distribution analysis, illustrated by case studies of three tropical species from different aquatic environments: tilapia (Oreochromis aureus), red octopus (Octopus maya) and the Caribbean spiny lobster (Panulirus argus). The analysis undertaken compared the size distribution of males and females of a given cohort through modal progression analysis. The technique used proved to be useful for highlighting the differences in growth between females and males of a specific cohort. The potential effect of extrinsic and intrinsic factors on the organism's development as reflected in the size distribution of the cohorts is discussed.

Tropical myeloneuropathies: the hidden endemias.

Science.gov (United States)

Román, G C; Spencer, P S; Schoenberg, B S

1985-08-01

Tropical myeloneuropathies include tropical ataxic neuropathy and tropical spastic paraparesis. These disorders occur in geographic isolates in several developing countries and are associated with malnutrition, cyanide intoxication from cassava consumption, tropical malabsorption (TM), vegetarian diets, and lathyrism. TM-malnutrition was a probable cause of myeloneuropathies among Far East prisoners of war in World War II. Clusters of unknown etiology occur in India, Africa, the Seychelles, several Caribbean islands, Jamaica, and Colombia. Treponemal infection (yaws) could be an etiologic factor in the last two. Tropical myeloneuropathies, a serious health problem, are multifactorial conditions that provide unsurpassed opportunities for international cooperation and neurologic research.

Ecological restoration success is higher for natural regeneration than for active restoration in tropical forests.

Science.gov (United States)

Crouzeilles, Renato; Ferreira, Mariana S; Chazdon, Robin L; Lindenmayer, David B; Sansevero, Jerônimo B B; Monteiro, Lara; Iribarrem, Alvaro; Latawiec, Agnieszka E; Strassburg, Bernardo B N

2017-11-01

Is active restoration the best approach to achieve ecological restoration success (the return to a reference condition, that is, old-growth forest) when compared to natural regeneration in tropical forests? Our meta-analysis of 133 studies demonstrated that natural regeneration surpasses active restoration in achieving tropical forest restoration success for all three biodiversity groups (plants, birds, and invertebrates) and five measures of vegetation structure (cover, density, litter, biomass, and height) tested. Restoration success for biodiversity and vegetation structure was 34 to 56% and 19 to 56% higher in natural regeneration than in active restoration systems, respectively, after controlling for key biotic and abiotic factors (forest cover, precipitation, time elapsed since restoration started, and past disturbance). Biodiversity responses were based primarily on ecological metrics of abundance and species richness (74%), both of which take far less time to achieve restoration success than similarity and composition. This finding challenges the widely held notion that natural forest regeneration has limited conservation value and that active restoration should be the default ecological restoration strategy. The proposition that active restoration achieves greater restoration success than natural regeneration may have arisen because previous comparisons lacked controls for biotic and abiotic factors; we also did not find any difference between active restoration and natural regeneration outcomes for vegetation structure when we did not control for these factors. Future policy priorities should align the identified patterns of biophysical and ecological conditions where each or both restoration approaches are more successful, cost-effective, and compatible with socioeconomic incentives for tropical forest restoration.

Quality maintenance Tropical Plants

Directory of Open Access Journals (Sweden)

Gláucia Moraes Dias

2016-11-01

Full Text Available The climatic characteristics of the country favor the cultivation of tropical flowers. The continued expansion of this market is due the beauty, exoticit nature and postharvest longevity of flower. However, little is known about the postharvest of tropical plants. Therefore, this paper provides information on harvest, handling and storage of cut tropical plantspostharvest, storage temperature, conditioning solution.

Asian American women in science, engineering, and mathematics: Background contextual and college environment influences on self-efficacy and academic achievement

Science.gov (United States)

Vogt, Kristen E.

2005-07-01

The purpose of this research study was to examine, for undergraduate women of various Asian American ethnic backgrounds, the influence of background contextual and college environment factors on their sense of academic self-efficacy and achievement in science, technology, engineering, and mathematics (STEM) majors. Social cognitive career theory and its critiques provided a theoretical foundation for relationships from past performance, socioeconomic status, acculturation, and college environment variables (compositional diversity, racial climate, gendered climate, academic peer support), to academic self-efficacy and achievement. Data were collected through an online survey. Instrumentation included the scales of Language, Identity, and Behavioral Acculturation; Gender Discrimination; Faculty and Classroom Behavior; Interactions with Peers; and Academic Milestones Self-efficacy. The participants were 228 Asian American undergraduate women in STEM at a large public, doctoral research extensive university on the east coast; the response rate was 51%. In three MANOVAs for nine social cognitive career variables, four ethnic groups (East, South, Southeast, and Multi-ethnic Asian American) significantly differed only on socioeconomic status. In path analysis, the initial model was not a good fit and was rejected. The model was respecified through statistical and theoretical evaluation, tested in exploratory analysis, and considered a good fit. The respecified model explained 36% of semester GPA (achievement) and 28% of academic self-efficacy. The academic achievement of Asian American women in STEM was related to past performance, background contextual factors, academic self-efficacy, academic peer support, and gendered climate. The strongest direct influence on achievement was academic self-efficacy followed by past performance. The total effect of Asian acculturation on achievement was negative and the total effect of American acculturation on achievement was not

Pathways, mechanisms and predictability of vegetation change during tropical dry forest succession

NARCIS (Netherlands)

Lebrija Trejos, E.E.; Meave, J.; Poorter, L.; Pérez- García, E.A.; Bongers, F.

2010-01-01

The development of forest succession theory has been based on studies in temperate and tropical wet forests. As rates and pathways of succession vary with the environment, advances in successional theory and study approaches are challenged by controversies derived from such variation and by the

The world bank and the environment. Progress report

International Nuclear Information System (INIS)

1991-01-01

The second annual report describes specific environmental strategies and environmental lending in the Bank's four operational regions: Africa; Asia; Europe, Middle East, and North Africa; and Latin America and the Caribbean. It details the Bank's progress in eight environmental categories: energy and the environment, pollution, urban environment, water resources management, forest and land management, social and cultural, environmental economics, and the global environment. One chapter is devoted exclusively to tropical forests, studying ways in which the Bank is dealing with deforestation as a part of the constant review of its forest policies. Suggestions are made for decreasing the degradation of tropical forests while meeting demands for forest products. This chapter reflects a shift in Bank emphasis from commercial ventures to conservation measures. The publication reports on other initiatives by the Bank during fiscal 1991, including the launching of the Global Environment Facility (GEF)--a pilot program to oversee reduction of global warming, preservation of biological diversity, protection of international waters, and prevention of ozone depletion

Cellular Metabolic Rate Is Influenced by Life-History Traits in Tropical and Temperate Birds

Science.gov (United States)

Jimenez, Ana Gabriela; Van Brocklyn, James; Wortman, Matthew; Williams, Joseph B.

2014-01-01

In general, tropical birds have a “slow pace of life,” lower rates of whole-animal metabolism and higher survival rates, than temperate species. A fundamental challenge facing physiological ecologists is the understanding of how variation in life-history at the whole-organism level might be linked to cellular function. Because tropical birds have lower rates of whole-animal metabolism, we hypothesized that cells from tropical species would also have lower rates of cellular metabolism than cells from temperate species of similar body size and common phylogenetic history. We cultured primary dermal fibroblasts from 17 tropical and 17 temperate phylogenetically-paired species of birds in a common nutritive and thermal environment and then examined basal, uncoupled, and non-mitochondrial cellular O2 consumption (OCR), proton leak, and anaerobic glycolysis (extracellular acidification rates [ECAR]), using an XF24 Seahorse Analyzer. We found that multiple measures of metabolism in cells from tropical birds were significantly lower than their temperate counterparts. Basal and uncoupled cellular metabolism were 29% and 35% lower in cells from tropical birds, respectively, a decrease closely aligned with differences in whole-animal metabolism between tropical and temperate birds. Proton leak was significantly lower in cells from tropical birds compared with cells from temperate birds. Our results offer compelling evidence that whole-animal metabolism is linked to cellular respiration as a function of an animal’s life-history evolution. These findings are consistent with the idea that natural selection has uniquely fashioned cells of long-lived tropical bird species to have lower rates of metabolism than cells from shorter-lived temperate species. PMID:24498080

Plant biodiversity changes in Carboniferous tropical wetlands

DEFF Research Database (Denmark)

Cleal, C. J.; Uhl, D.; Cascales-Miñana, B.

2012-01-01

and Sydney coal basins. In all cases, species richness expansion followed an essentially logistic curve typical of that associated with ecologically closed habitats, with niche saturation being achieved in about three million years. The resulting steady-state (“climax”) coal swamp vegetation had a local......Using a combination of species richness, polycohort and constrained cluster analyses, the plant biodiversity of Pennsylvanian (late Carboniferous) tropical wetlands (“coal swamps”) has been investigated in five areas in Western Europe and eastern North America: South Wales, Pennines, Ruhr, Saarland...

Pneumonia in the tropics.

Science.gov (United States)

Lim, Tow Keang; Siow, Wen Ting

2018-01-01

Pneumonia in the tropics poses a heavy disease burden. The complex interplay of climate change, human migration influences and socio-economic factors lead to changing patterns of respiratory infections in tropical climate but also increasingly in temperate countries. Tropical and poorer countries, especially South East Asia, also bear the brunt of the global tuberculosis (TB) pandemic, accounting for almost one-third of the burden. But, as human migration patterns evolve, we expect to see more TB cases in higher income as well as temperate countries, and rise in infections like scrub typhus from ecotourism activities. Fuelled by the ease of air travel, novel zoonotic infections originating from the tropics have led to global respiratory pandemics. As such, clinicians worldwide should be aware of these new conditions as well as classical tropical bacterial pneumonias such as melioidosis. Rarer entities such as co-infections of leptospirosis and chikungunya or dengue will need careful consideration as well. In this review, we highlight aetiologies of pneumonia seen more commonly in the tropics compared with temperate regions, their disease burden, variable clinical presentations as well as impact on healthcare delivery. © 2017 Asian Pacific Society of Respirology.

Tropical Veterinarian: Submissions

African Journals Online (AJOL)

Author Guidelines. 2012 Author Guidelines: Instructions to Authors: TROPICAL VETERINARIAN welcomes original work on all aspects of veterinary science as practiced in the Tropics, including livestock production and management, animal disease (domestic and wild), various aspects of preventive medicine and public ...

Hygroscopical behaviour of basic electrodes in a tropical humid climate

International Nuclear Information System (INIS)

Valencia, E.; Galeano, N.J.

1993-01-01

The study of the wetting kynetics of basic electrodes in a tropical humid climate is very important since the water contained in them is the main source for the atomic hydrogen absorbed by the fused metal during electric arc welding. It is also the origin of multiple defects in the added metal. A calculating method is established for evaluating the kynetics of wetness incorporation to the coating of basic electrodes exposed to a humid tropical climate. The method is based on the Fick's diffusion equation for both adequate system geometry and boundary conditions, which allows the evaluation of the effective diffusion coefficient and critical times of exposure to the different environments, along with the packing and storage conditions of electrodes. (Author)

Tropical Cyclone Propagation

National Research Council Canada - National Science Library

Gray, William

1994-01-01

This paper discusses the question of tropical cyclone propagation or why the average tropical cyclone moves 1-2 m/s faster and usually 10-20 deg to the left of its surrounding (or 5-7 deg radius) deep layer (850-300 mb) steering current...

Neglected tropical diseases outside the tropics.

Directory of Open Access Journals (Sweden)

Francesca F Norman

Full Text Available BACKGROUND: The neglected tropical diseases (NTDs cause significant morbidity and mortality worldwide. Due to the growth in international travel and immigration, NTDs may be diagnosed in countries of the western world, but there has been no specific focus in the literature on imported NTDs. METHODS: Retrospective study of a cohort of immigrants and travelers diagnosed with one of the 13 core NTDs at a Tropical Medicine Referral Unit in Spain during the period April 1989-December 2007. Area of origin or travel was recorded and analyzed. RESULTS: There were 6168 patients (2634 immigrants, 3277 travelers and 257 VFR travelers in the cohort. NTDs occurred more frequently in immigrants, followed by VFR travelers and then by other travelers (p<0.001 for trend. The main NTDs diagnosed in immigrants were onchocerciasis (n = 240, 9.1% acquired mainly in sub-Saharan Africa, Chagas disease (n = 95, 3.6% in immigrants from South America, and ascariasis (n = 86, 3.3% found mainly in immigrants from sub-Saharan Africa. Most frequent NTDs in travelers were: schistosomiasis (n = 43, 1.3%, onchocerciasis (n = 17, 0.5% and ascariasis (n = 16, 0.5%, and all were mainly acquired in sub-Saharan Africa. The main NTDs diagnosed in VFR travelers were onchocerciasis (n = 14, 5.4%, and schistosomiasis (n = 2, 0.8%. CONCLUSIONS: The concept of imported NTDs is emerging as these infections acquire a more public profile. Specific issues such as the possibility of non-vectorial transmission outside endemic areas and how some eradication programmes in endemic countries may have an impact even in non-tropical western countries are addressed. Recognising NTDs even outside tropical settings would allow specific prevention and control measures to be implemented and may create unique opportunities for research in future.

Causes of postpartum anoestrus in cattle in the tropics

International Nuclear Information System (INIS)

Hansel, W.; Alila, H.W.

1984-01-01

Prolonged postpartum anoestrus is a major cause of economic losses in cattle in most tropical countries. The length of the period from parturition to first oestrus varies greatly in cattle in the tropics and is influenced by many factors, including endocrine events, management, nutrition, heat and humidity, genetic-environmental interactions, diseases and internal and external parasites. Results of recent research on endocrinology of the postpartum cow are particularly relevant to the problem in tropical cattle. Development of a pulsatile pattern of pituitary luteinizing hormone (LH) secretion is necessary for induction of the first postpartum oestrus, and many cows undergo a short episode of elevated plasma progesterone levels immediately before the first oestrus. Adrenal corticosteroids inhibit development of the pulsatile pattern of LH secretion. The concept is developed that elevated levels of cortisol, resulting from the stresses of heat, high humidity, malnutrition, parasites and diseases to which tropical cattle are often exposed, contribute to anoestrus. Techniques developed for oestrous cycle synchronization of cyclic cattle have been found to induce first oestrus and a fertile ovulation in a significant percentage of anoestrous lactating beef cattle. These treatments involve short-term (6-7 day) progesterone treatments, followed by single injections of prostaglandin Fsub(2α) and insemination 80 hours later. Some success has also been achieved in shortening the postpartum interval by pulsatile administration of gonadotropin-releasing hormone which, in turn, causes pulsatile release of LH, and by administering progestational compounds for short periods of time. Improved management, particularly oestrus detection and insemination at the optimum time, could contribute greatly to reducing the postpartum interval in tropical cattle. Nutritional factors that result in reduced haemoglobin levels (trace mineral deficiencies and parasite infestations) also cause

Tropical Cyclogenesis in a Tropical Wave Critical Layer: Easterly Waves

Science.gov (United States)

Dunkerton, T. J.; Montgomery, M. T.; Wang, Z.

2009-01-01

The development of tropical depressions within tropical waves over the Atlantic and eastern Pacific is usually preceded by a "surface low along the wave" as if to suggest a hybrid wave-vortex structure in which flow streamlines not only undulate with the waves, but form a closed circulation in the lower troposphere surrounding the low. This structure, equatorward of the easterly jet axis, is identified herein as the familiar critical layer of waves in shear flow, a flow configuration which arguably provides the simplest conceptual framework for tropical cyclogenesis resulting from tropical waves, their interaction with the mean flow, and with diabatic processes associated with deep moist convection. The recirculating Kelvin cat's eye within the critical layer represents a sweet spot for tropical cyclogenesis in which a proto-vortex may form and grow within its parent wave. A common location for storm development is given by the intersection of the wave's critical latitude and trough axis at the center of the cat's eye, with analyzed vorticity centroid nearby. The wave and vortex live together for a time, and initially propagate at approximately the same speed. In most cases this coupled propagation continues for a few days after a tropical depression is identified. For easterly waves, as the name suggests, the propagation is westward. It is shown that in order to visualize optimally the associated Lagrangian motions, one should view the flow streamlines, or stream function, in a frame of reference translating horizontally with the phase propagation of the parent wave. In this co-moving frame, streamlines are approximately equivalent to particle trajectories. The closed circulation is quasi-stationary, and a dividing streamline separates air within the cat's eye from air outside.

Introduction to tropical geometry

CERN Document Server

Maclagan, Diane

2015-01-01

Tropical geometry is a combinatorial shadow of algebraic geometry, offering new polyhedral tools to compute invariants of algebraic varieties. It is based on tropical algebra, where the sum of two numbers is their minimum and the product is their sum. This turns polynomials into piecewise-linear functions, and their zero sets into polyhedral complexes. These tropical varieties retain a surprising amount of information about their classical counterparts. Tropical geometry is a young subject that has undergone a rapid development since the beginning of the 21st century. While establishing itself as an area in its own right, deep connections have been made to many branches of pure and applied mathematics. This book offers a self-contained introduction to tropical geometry, suitable as a course text for beginning graduate students. Proofs are provided for the main results, such as the Fundamental Theorem and the Structure Theorem. Numerous examples and explicit computations illustrate the main concepts. Each of t...

Specificity for field enumeration of Escherichia coli in tropical surface waters

DEFF Research Database (Denmark)

Jensen, Peter Kjær Mackie; Aalbaek, B; Aslam, R

2001-01-01

In remote rural areas in developing countries, bacteriological monitoring often depends on the use of commercial field media. This paper evaluates a commercial field medium used for the enumeration of Escherichia coli in different surface waters under primitive field conditions in rural Pakistan....... In order to verify the field kit, 117 presumptive E. coli isolates have been tested, finding a specificity of only 40%. By excluding some strains based on colony colours, the calculated specificity could be increased to 65%. Thus, it is suggested that prior to use in a tropical environment, the specificity...... of any commercial medium used should be tested with representative tropical isolates, in order to increase the specificity....

Computing Tropical Varieties

DEFF Research Database (Denmark)

Speyer, D.; Jensen, Anders Nedergaard; Bogart, T.

2005-01-01

The tropical variety of a d-dimensional prime ideal in a polynomial ring with complex coefficients is a pure d-dimensional polyhedral fan. This fan is shown to be connected in codimension one. We present algorithmic tools for computing the tropical variety, and we discuss our implementation...

A short review of fecal indicator bacteria in tropical aquatic ecosystems: knowledge gaps and future directions

Directory of Open Access Journals (Sweden)

Emma Jane Rochelle-Newall

2015-04-01

Full Text Available Given the high numbers of deaths and the debilitating nature of diseases caused by the use of unclean water it is imperative that we have an understanding of the factors that control the dispersion of water borne pathogens and their respective indicators. This is all the more important in developing countries where significant proportions of the population often have little or no access to clean drinking water supplies. Moreover, and notwithstanding the importance of these bacteria in terms of public health, at present little work exists on the persistence, transfer and proliferation of these pathogens and their respective indicator organisms e.g. fecal indicator bacteria (FIB such as Escherichia coli and fecal coliforms in humid tropical systems, such as are found in South East Asia or in the tropical regions of Africa. Both FIB and the waterborne pathogens they are supposed to indicate are particularly susceptible to shifts in water flow and quality and the predicted increases in rainfall and floods due to climate change will only exacerbate the problems of contamination. This will be furthermore compounded by the increasing urbanization and agricultural intensification that developing regions are experiencing. Therefore, recognizing and understanding the link between human activities, natural process and microbial functioning and their ultimate impacts on human health are prerequisites for reducing the risks to the exposed populations. Most of the existing work in tropical systems has been based on the application of temperate indicator organisms, models and mechanisms regardless of their applicability or appropriateness for tropical environments. Here we present a short review on the factors that control FIB dynamics in temperate systems and discuss their applicability to tropical environments. We then highlight some of the knowledge gaps in order to stimulate future research in this field in the tropics.

A short review of fecal indicator bacteria in tropical aquatic ecosystems: knowledge gaps and future directions.

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Rochelle-Newall, Emma; Nguyen, Thi Mai Huong; Le, Thi Phuong Quynh; Sengtaheuanghoung, Oloth; Ribolzi, Olivier

2015-01-01

Given the high numbers of deaths and the debilitating nature of diseases caused by the use of unclean water it is imperative that we have an understanding of the factors that control the dispersion of water borne pathogens and their respective indicators. This is all the more important in developing countries where significant proportions of the population often have little or no access to clean drinking water supplies. Moreover, and notwithstanding the importance of these bacteria in terms of public health, at present little work exists on the persistence, transfer and proliferation of these pathogens and their respective indicator organisms, e.g., fecal indicator bacteria (FIB) such as Escherichia coli and fecal coliforms in humid tropical systems, such as are found in South East Asia or in the tropical regions of Africa. Both FIB and the waterborne pathogens they are supposed to indicate are particularly susceptible to shifts in water flow and quality and the predicted increases in rainfall and floods due to climate change will only exacerbate the problems of contamination. This will be furthermore compounded by the increasing urbanization and agricultural intensification that developing regions are experiencing. Therefore, recognizing and understanding the link between human activities, natural process and microbial functioning and their ultimate impacts on human health are prerequisites for reducing the risks to the exposed populations. Most of the existing work in tropical systems has been based on the application of temperate indicator organisms, models and mechanisms regardless of their applicability or appropriateness for tropical environments. Here, we present a short review on the factors that control FIB dynamics in temperate systems and discuss their applicability to tropical environments. We then highlight some of the knowledge gaps in order to stimulate future research in this field in the tropics.

Tropical varieties, maps and gossip

NARCIS (Netherlands)

Frenk, B.J.

2013-01-01

Tropical geometry is a relatively new field of mathematics that studies the tropicalization map: a map that assigns a certain type of polyhedral complex, called a tropical variety, to an embedded algebraic variety. In a sense, it translates algebraic geometric statements into combinatorial ones. An

Accelerated evolutionary rates in tropical and oceanic parmelioid lichens (Ascomycota

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Blanco Oscar

2008-09-01

Full Text Available Abstract Background The rate of nucleotide substitutions is not constant across the Tree of Life, and departures from a molecular clock have been commonly reported. Within parmelioid lichens, the largest group of macrolichens, large discrepancies in branch lengths between clades were found in previous studies. Using an extended taxon sampling, we test for presence of significant rate discrepancies within and between these clades and test our a priori hypothesis that such rate discrepancies may be explained by shifts in moisture regime or other environmental conditions. Results In this paper, the first statistical evidence for accelerated evolutionary rate in lichenized ascomycetes is presented. Our results give clear evidence for a faster rate of evolution in two Hypotrachyna clades that includes species occurring in tropical and oceanic habitats in comparison with clades consisting of species occurring in semi-arid and temperate habitats. Further we explore potential links between evolutionary rates and shifts in habitat by comparing alternative Ornstein-Uhlenbeck models. Conclusion Although there was only weak support for a shift at the base of a second tropical clade, where the observed nucleotide substitution rate is high, overall support for a shift in environmental conditions at cladogenesis is very strong. This suggests that speciation in some lichen clades has proceeded by dispersal into a novel environment, followed by radiation within that environment. We found moderate support for a shift in moisture regime at the base of one tropical clade and a clade occurring in semi-arid regions and a shift in minimum temperature at the base of a boreal-temperate clade.

Stratified coastal ocean interactions with tropical cyclones

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Glenn, S. M.; Miles, T. N.; Seroka, G. N.; Xu, Y.; Forney, R. K.; Yu, F.; Roarty, H.; Schofield, O.; Kohut, J.

2016-01-01

Hurricane-intensity forecast improvements currently lag the progress achieved for hurricane tracks. Integrated ocean observations and simulations during hurricane Irene (2011) reveal that the wind-forced two-layer circulation of the stratified coastal ocean, and resultant shear-induced mixing, led to significant and rapid ahead-of-eye-centre cooling (at least 6 °C and up to 11 °C) over a wide swath of the continental shelf. Atmospheric simulations establish this cooling as the missing contribution required to reproduce Irene's accelerated intensity reduction. Historical buoys from 1985 to 2015 show that ahead-of-eye-centre cooling occurred beneath all 11 tropical cyclones that traversed the Mid-Atlantic Bight continental shelf during stratified summer conditions. A Yellow Sea buoy similarly revealed significant and rapid ahead-of-eye-centre cooling during Typhoon Muifa (2011). These findings establish that including realistic coastal baroclinic processes in forecasts of storm intensity and impacts will be increasingly critical to mid-latitude population centres as sea levels rise and tropical cyclone maximum intensities migrate poleward. PMID:26953963

The Effects of Cooperative and Collaborative Strategies on Student Achievement and Satisfaction in Blended and Online Learning Environments

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Nickel, Christine E.

2010-01-01

The purpose of this study was to examine whether cooperative versus collaborative strategies used for a group project had differential effects on students' achievement, process and solution satisfaction, value and preference for collaboration, and perceptions of community of inquiry in online and blended environments. The study sample consisted of…

Wet tropical climate in SE Tibet during the Late Eocene.

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Sorrel, Philippe; Eymard, Ines; Leloup, Philippe-Herve; Maheo, Gweltaz; Olivier, Nicolas; Sterb, Mary; Gourbet, Loraine; Wang, Guocan; Jing, Wu; Lu, Haijian; Li, Haibing; Yadong, Xu; Zhang, Kexin; Cao, Kai; Chevalier, Marie-Luce; Replumaz, Anne

2017-08-10

Cenozoic climate cooling at the advent of the Eocene-Oligocene transition (EOT), ~33.7 Ma ago, was stamped in the ocean by a series of climatic events albeit the impact of this global climatic transition on terrestrial environments is still fragmentary. Yet archival constraints on Late Eocene atmospheric circulation are scarce in (tropical) monsoonal Asia, and the paucity of terrestrial records hampers a meaningful comparison of the long-term climatic trends between oceanic and continental realms. Here we report new sedimentological data from the Jianchuan basin (SE Tibet) arguing for wetter climatic conditions in monsoonal Asia at ~35.5 Ma almost coevally to the aridification recognized northwards in the Xining basin. We show that the occurrence of flash-flood events in semi-arid to sub-humid palustrine-sublacustrine settings preceded the development of coal-bearing deposits in swampy-like environments, thus paving the way to a more humid climate in SE Tibet ahead from the EOT. We suggest that this moisture redistribution possibly reflects more northern and intensified ITCZ-induced tropical rainfall in monsoonal Asia around 35.5 Ma, in accordance with recent sea-surface temperature reconstructions from equatorial oceanic records. Our findings thus highlight an important period of climatic upheaval in terrestrial Asian environments ~2-4 millions years prior to the EOT.

Management of the coastal biophysical environment in tropical Queensland under conditions of heavy developmental pressure: the case of tourist resorts and acid sulphate soils

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Patricia Erfurt-Haupt

2008-09-01

Full Text Available La côte tropicale du Queensland est confrontée à un accroissement rapide de la population. Les fortes pressions anthropiques pèsent sur le milieu biophysique, qui comprend notamment a plus grande île de sable du monde, un site classé Patrimoine de l’Humanité, Port Hinchinbrook et Fraser Island.  Malgré l’existence d’une législation nationale orientée vers la préservation de l’environnement, il est manifeste que peu d’attention est accordée aux effets à long terme des sites touristiques et du développement de l’urbanisation sur ces franges côtières sensibles. L’aspect massif des flux de visiteurs et leurs impacts sur le milieu naturel a été identifié comme un sujet d’inquiétude particulier dans certaines régions. La connaissance des impacts sur la géomorphologie côtière souterraine est très réduite et les choix de développement sont souvent faits dans l’ignorance ou au mépris de la présence répandue de terrains de sulfate d’acide dans ce milieu côtier. Des sols réactifs comme ceux-là peuvent affecter, et affectent, grandement les résultats géophysiques d’un développement lorsqu’ils sont connus. Des études de cas sur le problème des sols de sulfate d’acide suggèrent qu’une partie de la solution pour le gouvernement de l’Etat du Queensland est d’imposer des normes obligatoires pour le développement du tourisme dans la zone côtière.The tropical coast of Queensland, Australia is experiencing rapid population and tourism growth. Heavy development pressure is being placed on the biophysical environment, which includes the largest sand island in the world (World Heritage listed, Fraser Island. Despite the existence of State planning legislation oriented towards environmental sustainability, it is apparent that little, if any, regard is being paid to the long-term effects of resort and canal-estate development on the underlying biophysical environment of the coast and islands. �

Biodegradation of di(2-ethylhexyl)phthalate in a typical tropical soil

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Castelo de Moura Carrara, Silvia Marta; Morita, Dione Mari [Polytechnic School, University of Sao Paulo (Brazil); Boscov, Maria Eugenia Gimenez, E-mail: meboscov@usp.br [Polytechnic School, University of Sao Paulo (Brazil)

2011-12-15

Highlights: Black-Right-Pointing-Pointer Scarce literature on contamination of tropical soils by phthalates. Black-Right-Pointing-Pointer Investigation of mobility of DEHP in a tropical soil by infiltration tests showed that DEHP is retained in the upper layer of the soil. Black-Right-Pointing-Pointer Low air and water permeability indicate that in situ bioremediation is not feasible for this soil. Black-Right-Pointing-Pointer Respirometric tests were inadequate to investigate biodegradation because tropical soils are acidic. Black-Right-Pointing-Pointer Slurry-phase reactor with cement mixer provided significant biodegradation (99% in 49 days). - Abstract: The aim of this research was to evaluate the possibility of biodegradation of di(2-ethylhexyl)phthalate (DEHP), widely used as an industrial plasticizer and considered an endocrine-disrupting chemical included in the U.S. Environmental Protection Agency priority list, in a Brazilian tropical soil, which has not been previously reported in the literature, despite the geographic importance of tropical soils. Preliminary laboratory testing comprised respirometric, air and water permeability, and pilot scale infiltration tests. Standard respirometric tests were found inadequate for studying biodegradation in tropical contaminated soils, due to the effect of the addition of significant amounts of calcium carbonate, necessary to adjust soil pH. Pilot scale infiltration tests performed for 5 months indicated that DEHP was retained in the superficial layer of the soil, barely migrating downwards, whereas air and water permeability tests discarded in situ bioremediation. However, ex situ bioremediation was possible, using a slurry-phase reactor with acclimated microorganisms, in pilot scale tests conducted to remediate a total mass of 150 kg of contaminated soil with 100 mg DEHP/kg. The removal of DEHP in the slurry-phase reactor achieved the percentage of 99% in 49 days, with biodegradation following a first

Interannual Weakening of the Tropical Pacific Walker Circulation Due to Strong Tropical Volcanism

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Miao, Jiapeng; Wang, Tao; Wang, Huijun; Sun, Jianqi

2018-06-01

In order to examine the response of the tropical Pacific Walker circulation (PWC) to strong tropical volcanic eruptions (SVEs), we analyzed a three-member long-term simulation performed with HadCM3, and carried out four additional CAM4 experiments. We found that the PWC shows a significant interannual weakening after SVEs. The cooling effect from SVEs is able to cool the entire tropics. However, cooling over the Maritime Continent is stronger than that over the central-eastern tropical Pacific. Thus, non-uniform zonal temperature anomalies can be seen following SVEs. As a result, the sea level pressure gradient between the tropical Pacific and the Maritime Continent is reduced, which weakens trade winds over the tropical Pacific. Therefore, the PWC is weakened during this period. At the same time, due to the cooling subtropical and midlatitude Pacific, the Intertropical Convergence Zone (ITCZ) and South Pacific convergence zone (SPCZ) are weakened and shift to the equator. These changes also contribute to the weakened PWC. Meanwhile, through the positive Bjerknes feedback, weakened trade winds cause El Niño-like SST anomalies over the tropical Pacific, which in turn further influence the PWC. Therefore, the PWC significantly weakens after SVEs. The CAM4 experiments further confirm the influences from surface cooling over the Maritime Continent and subtropical/midlatitude Pacific on the PWC. Moreover, they indicate that the stronger cooling over the Maritime Continent plays a dominant role in weakening the PWC after SVEs. In the observations, a weakened PWC and a related El Niño-like SST pattern can be found following SVEs.

Macroecology of parental care in arthropods: higher mortality risk leads to higher benefits of offspring protection in tropical climates.

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Santos, Eduardo S A; Bueno, Pedro P; Gilbert, James D J; Machado, Glauco

2017-08-01

The intensity of biotic interactions varies around the world, in such a way that mortality risk imposed by natural enemies is usually higher in the tropics. A major role of offspring attendance is protection against natural enemies, so the benefits of this behaviour should be higher in tropical regions. We tested this macroecological prediction with a meta-regression of field experiments in which the mortality of guarded and unguarded broods was compared in arthropods. Mortality of unguarded broods was higher, and parental care was more beneficial, in warmer, less seasonal environments. Moreover, in these same environments, additional lines of defence further reduced offspring mortality, implying that offspring attendance alone is not enough to deter natural enemies in tropical regions. These results help to explain the high frequency of parental care among tropical species and how biotic interactions influence the occurrence of parental care over large geographic scales. Finally, our findings reveal that additional lines of defences - an oftentimes neglected component of parental care - have an important effect on the covariation between the benefits of parental care and the climate-mediated mortality risk imposed by natural enemies. © 2016 Cambridge Philosophical Society.

European cloth and "tropical" skin: clothing material and British ideas of health and hygiene in tropical climates.

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Johnson, Ryan

2009-01-01

As Britain's imperial and colonial ambitions intensified toward the end of the nineteenth century, the preservation of white European health in tropical climates became an increasingly important concern. Since at least the seventeenth century, the "tropics" had been seen as spaces holding vast potential wealth but also death and disease. To combat these deadly but desirable landscapes, the British built a considerable commodity culture around the preservation of white European health, and for many, tropical clothing was one of the most important and essential items in their "kits." This article investigates the composition and use of such clothing in relation to British ideas of health and hygiene in tropical climates. First, it considers debates that ensued over the best material--wool, cotton, linen, silk, or a combination of these materials--and the role of "black" skin and local practice in the development of tropical clothing. Second, it demonstrates the importance of location in any discussion of tropical medicine and hygiene, and the tension and ambiguity that still surrounded British ideas of health and hygiene in the tropical colonies. Third, it argues that tropical clothing was important in the maintenance of climatic etiologies despite advances in parasitology and sanitary science. Finally, it considers the relationship of tropical clothing to the formation of a unique colonial identity. To British men and women embarking for any number of tropical destinations, proper clothing was not a banal and mundane component of their outfitting. For many, the clothing signified a departure from the safe and "civil" climes of Britain for adventure in the expanding tropical empire.

Climate change in Australian tropical rainforests: an impending environmental catastrophe.

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Williams, Stephen E; Bolitho, Elizabeth E; Fox, Samantha

2003-01-01

It is now widely accepted that global climate change is affecting many ecosystems around the globe and that its impact is increasing rapidly. Many studies predict that impacts will consist largely of shifts in latitudinal and altitudinal distributions. However, we demonstrate that the impacts of global climate change in the tropical rainforests of northeastern Australia have the potential to result in many extinctions. We develop bioclimatic models of spatial distribution for the regionally endemic rainforest vertebrates and use these models to predict the effects of climate warming on species distributions. Increasing temperature is predicted to result in significant reduction or complete loss of the core environment of all regionally endemic vertebrates. Extinction rates caused by the complete loss of core environments are likely to be severe, nonlinear, with losses increasing rapidly beyond an increase of 2 degrees C, and compounded by other climate-related impacts. Mountain ecosystems around the world, such as the Australian Wet Tropics bioregion, are very diverse, often with high levels of restricted endemism, and are therefore important areas of biodiversity. The results presented here suggest that these systems are severely threatened by climate change. PMID:14561301

FAQ HURRICANES, TYPHOONS, AND TROPICAL CYCLONES

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? A6) What is a sub-tropical cyclone? A7) What is an extratropical cyclone ? A8) What is storm surge easterly wave and what causes them? A5) What is a tropical disturbance, tropical depression, tropical storm and how is it different from storm tide ? A9) What is a "CDO" ? A10) What is a TUTT ? A11

Inter-cohort growth for three tropical resources: tilapia, octopus and lobster

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Iván Velázquez-Abunader

2015-09-01

Full Text Available Growth parameters are an important component for the stock assessment of exploited aquatic species. However, it is often difficult to apply direct methods to estimate growth and to analyse the differences between males and females, particularly in tropical areas. The objective of this study was to analyse the inter-cohort growth of three tropical resources and discuss the possible fisheries management implications. A simple method was used to compare individual growth curves obtained from length frequency distribution analysis, illustrated by case studies of three tropical species from different aquatic environments: tilapia (Oreochromis aureus,red octopus (Octopus mayaand the Caribbean spiny lobster (Panulirus argus.The analysis undertaken compared the size distribution of males and females of a given cohort through modal progression analysis. The technique used proved to be useful for highlighting the differences in growth between females and males of a specific cohort. The potential effect of extrinsic and intrinsic factors on the organism's development as reflected in the size distribution of the cohorts is discussed.

Modelling the impact of rural migration on tropical deforestation in South-West Ethiopia

NARCIS (Netherlands)

Van Rompaey, Anton; Debonne, N.; Vanmaercke, Matthias

2016-01-01

A major driver of tropical deforestation is rural frontier migration. In this paper an attempt is made to formally describe the human-environment interactions that are manifested in a forested system experiencing a large influx of rural migrants. The Guraferda district in South-West Ethiopia was

Termites as ecological indicators of mine-land rehabilitation in tropical Australia

International Nuclear Information System (INIS)

Hinz, D.A.

2001-01-01

This paper presents examples from field research of termites as indicators of rehabilitation success in the wet-dry tropics at Nabalco's bauxite mine, Gove, Australia and in Sierra Leone, West Africa. Field studies indicate that soil-plant-animal interactions are crucial in determining the recovery of disturbed land and that termites play an over-riding role in the process. Termites are seen as ecological indicators for successful soil and vegetation development in humid tropical environments. In land rehabilitation, termites help to create healthy, self-regulated vegetation systems that integrate with the surrounding landscapes and build structures and functions equal to those of the pre-disturbed system. They are reliable in signaling the health and stress factors of a system and provide a predictable response

Gigantic Jet Environments: A Meteorological Evaluation Using Reanalysis Data Sets

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Splitt, M. E.; Lazarus, S. M.

2017-12-01

The meteorological conditions of gigantic jet (GJ) producing thunderstorms tend to be connected to maritime tropical environments. In particular, they have an affinity toward tropical disturbances including those with moderate values of upper tropospheric environmental wind shear. Wind shear related effects (including turbulence) in association with deep convection in these environments have been proposed as mechanisms for the arrangement of GJ favorable charge structures. This study focuses on a climatological evaluation in an effort to assess whether the proposed ingredients are consistent with observed GJ event regions. The Climate System Forecast System - Version 2 (CFSR V2) is used here to test for the proposed GJ conditions.

Sub-tropical urban environment affecting content and composition of non-structural carbohydrates of Lolium multiflorum ssp. italicum cv. Lema

International Nuclear Information System (INIS)

Sandrin, Carla Zuliani; Figueiredo-Ribeiro, Rita de Cassia Leone; Carvalho, Maria Angela Machado de; Carvalho Delitti, Welington Braz; Domingos, Marisa

2008-01-01

This study analyzed the relationship between environmental factors, especially air pollution and climatic conditions, and non-structural carbohydrates (NSC) in plants of Lolium multiflorum exposed during 10 consecutive periods of 28 days at a polluted site (Congonhas) and at a reference site in Sao Paulo city (Brazil). After exposure, NSC composition and leaf concentrations of Al, Fe, Cu, Zn, Pb and Cd were measured. The seasonal pattern of NSC accumulation was quite similar in both sites, but plants at Congonhas showed higher concentrations of these compounds, especially fructans of low and medium degree of polymerization. Regression analysis showed that NSC in plants growing at the polluted site were explained by variations on temperature and leaf concentration of Fe (positive effect), as well as relative humidity and particulate material (negative effect). NSC in the standardized grass culture, in addition to heavy metal accumulation, may indicate stressing conditions in a sub-tropical polluted environment. - Particulate matter and air temperature increased non-structural carbohydrates in the standardized biomonitor grass in Sao Paulo

Sub-tropical urban environment affecting content and composition of non-structural carbohydrates of Lolium multiflorum ssp. italicum cv. Lema

Energy Technology Data Exchange (ETDEWEB)

Sandrin, Carla Zuliani; Figueiredo-Ribeiro, Rita de Cassia Leone; Carvalho, Maria Angela Machado de [Instituto de Botanica, Caixa Postal 3005, 01061-970 Sao Paulo, SP (Brazil); Carvalho Delitti, Welington Braz [Instituto de Biociencias, Universidade de Sao Paulo, Departamento de Ecologia, Caixa Postal 11461, 05422-970 Sao Paulo, SP (Brazil); Domingos, Marisa [Instituto de Botanica, Caixa Postal 3005, 01061-970 Sao Paulo, SP (Brazil)], E-mail: mmingos@superig.com.br

2008-12-15

This study analyzed the relationship between environmental factors, especially air pollution and climatic conditions, and non-structural carbohydrates (NSC) in plants of Lolium multiflorum exposed during 10 consecutive periods of 28 days at a polluted site (Congonhas) and at a reference site in Sao Paulo city (Brazil). After exposure, NSC composition and leaf concentrations of Al, Fe, Cu, Zn, Pb and Cd were measured. The seasonal pattern of NSC accumulation was quite similar in both sites, but plants at Congonhas showed higher concentrations of these compounds, especially fructans of low and medium degree of polymerization. Regression analysis showed that NSC in plants growing at the polluted site were explained by variations on temperature and leaf concentration of Fe (positive effect), as well as relative humidity and particulate material (negative effect). NSC in the standardized grass culture, in addition to heavy metal accumulation, may indicate stressing conditions in a sub-tropical polluted environment. - Particulate matter and air temperature increased non-structural carbohydrates in the standardized biomonitor grass in Sao Paulo.

Influence of tropical environmental and climatic factors on the daily urinary excretion in Nigeria

International Nuclear Information System (INIS)

Arogunjo, A.M.; Giussani, Augusto

2008-01-01

Full text: The daily urinary volume excreted is very crucial in order to accurately determine the excretion rate of substance needed for bioassay monitoring purposes. The International Commission on Radiological Protection (ICRP) Publication 89 reported a worldwide reference value of daily urinary volume based on the data from the temperate environment. However, in order to gain global acceptance, it is necessary to incorporate data from all parts of the world. To the best of our knowledge the present value did not include contribution from the tropical Africa. Daily dietary habits and level of exercise are considered to contribute significantly to the daily urinary excretion in normal human subject. In addition, environmental factors such as air temperature, pressure and humidity seem to play a major contributing role in tropical environments as indicated in a preliminary work conducted with a limited number of volunteers. In order to improve the statistical significance of the study, twenty four hours urine collection from large number (> 500) of subjects was conducted. The results of the study, intra- and inter variability of urine excretion, the dependence on age, gender, working habits, and the possible influence of tropical environmental conditions on the daily urine volume will be presented and discussed. (author)

Impact of tropical cyclone Matmo on mixed zone of the Yellow and Bohai seas

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Guo, Jie; Ji, Diansheng; Hou, Chawei; Guo, Kai; Ji, Ling

2017-12-01

The Bohai Sea is a low-lying semi-enclosed sea area that is linked to the Yellow Sea via the Bohai straits (mixed zone). Its off shore seabed is shallow, which makes it vulnerable to serious marine meteorological disasters associated with the northward passage of Pacifi c tropical cyclones. Analyses on data of remote sensing and buoy of the mixed zone of the Yellow and Bohai seas indicate that all the wind speed, signifi cant wave height, and salinity (SAL) increased, sea surface temperature decreased, and wind energy density changed considerably during the passage of tropical cyclone Matmo on July 25, 2014. It was found that the SAL inversion layer in the mixed zone of the Yellow and Bohai Seas was caused by the tropical cyclone. Furthermore, it was found that the tropical cyclone transported the northern Yellow Sea cold water mass (NYSCWM) into the mixed zone of the Yellow and Bohai Seas. The NYSCWM has direct infl uence on both the aquaculture and the ecological environment of the region. Therefore, further research is needed to establish the mechanism behind the formation of the SAL inversion layer in the mixed zone, and to determine the infl uence of tropical cyclones on the NYSCWM.

Global analysis of threat status reveals higher extinction risk in tropical than in temperate bird sister species

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Reif Jiří

2016-06-01

Full Text Available Given increasing pressures upon biodiversity, identification of species’ traits related to elevated extinction risk is useful for more efficient allocation of limited resources for nature conservation. Despite its need, such a global analysis was lacking in the case of birds. Therefore, we performed this exercise for avian sister species using information about their global extinction risk from IUCN Red List. We focused on 113 pairs of sister species, each containing a threatened and an unthreatened species to factor out the effects of common evolutionary history on the revealed relationship. We collected data on five traits with expected relationships to species’ extinction risk based on previous studies performed at regional or national levels: breeding habitat (recognizing forest, grassland, wetland and oceanic species, latitudinal range position (temperate and tropics species, migration strategy (migratory and resident species, diet (carnivorous, insectivorous, herbivorous and omnivorous species and body mass. We related the extinction risk using IUCN threat level categories to species’ traits using generalised linear mixed effects models expecting lower risk for forest, temperate, omnivorous and smaller-bodied species. Our expectation was confirmed only in the case of latitudinal range position, as we revealed higher threat level for tropical than for temperate species. This relationship was robust to different methods of threat level expression and cannot be explained by a simple association of high bird species richness with the tropical zone. Instead, it seems that tropical species are more threatened because of their intrinsic characteristics such as slow life histories, adaptations to stable environments and small geographic ranges. These characteristics are obviously disadvantageous in conditions of current human-induced environmental perturbations. Moreover, given the absence of habitat effects, our study indicates that such

Accuracy and simultaneous selection gains for N-stress tolerance and N-use efficiency in maize tropical lines

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Leandro de Freitas Mendonça

Full Text Available ABSTRACT Maize plants can be N-use efficient or N-stress tolerant. The first have high yields in favorable environments but is drastically affected under stress conditions; whereas the second show satisfactory yields in stressful environments but only moderate ones under optimal conditions. In this context, our aim was to assess the possibility of selecting tropical maize lines that are simultaneously N-stress tolerant and N-use efficient and check for differences between simultaneous selection statistical methods. Sixty-four tropical maize lines were evaluated for Nitrogen Agronomic Efficiency (NAE and Low Nitrogen Tolerance (LNTI response indices and two per se selection indices, Low Nitrogen Agronomic Efficiency (LNAE and Harmonic Mean of Relative Performance (HMRP. We performed eight selection scenarios: LNAE; HMRP; Additive index; Mulamba-Mock index; and Independent culling levels. The last three was predicted by REML/BLUP single-trait and multi-trait using genotypic values of NAE and LNTI. The REML/BLUP multi-trait analysis was superior to the single-trait analysis due to high unfavorable correlation between NAE and LNTI. However, the accuracy and genotypic determination coefficient of NAE and LNTI were too low. Thus, neither single- nor multi-trait analysis achieved a good result for simultaneous selection nor N-use efficiency nor N-stress tolerance. LNAE obtained satisfactorily accurate values and genotypic determination coefficient, but its performance in selection gain was worse than HMRP, particularly in terms of N-use efficiency. Therefore, because of the superior performance in accuracy, genotypic determination coefficient and selection, HMRP was considered the best simultaneous selection methodology of the scenarios tested for N-use efficiency and N-stress tolerance.

Intensity of Urban Heat Islands in Tropical and Temperate Climates

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Margarete Cristiane de Costa Trindade Amorim

2017-12-01

Full Text Available Nowadays, most of the Earth’s population lives in urban areas. The replacement of vegetation by buildings and the general soil sealing, associated with human activity, lead to a rise in cities temperature, resulting in the formation of urban heat islands. This article aims to evaluate the intensity and the hourly maintenance of the atmospheric heat islands in two climates: one tropical (Presidente Prudente, Brazil and one temperate (Rennes, France throughout 2016. For this, air temperature and hourly averages were measured and calculated using both a HOBO datalogger (U23-002—protected under the same RS3 brand and weather stations Davis Vantage PRO 2. The daily evolution of the heat islands presented characteristics that varied according to the hours and seasons of the year. For both Rennes and Presidente Prudente, the largest magnitudes occurred overnight, being more greatly expressed in the tropical environment and during the driest months (winter in the tropical city and summer in the temperate one. The variability of synoptic conditions from one month to another also leads to a great heterogeneity of UHI intensity throughout the year.

Harnessing Big Data for Communicable Tropical and Sub-Tropical Disorders: Implications From a Systematic Review of the Literature

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Vincenza Gianfredi

2018-03-01

Full Text Available AimAccording to the World Health Organization (WHO, communicable tropical and sub-tropical diseases occur solely, or mainly in the tropics, thriving in hot, and humid conditions. Some of these disorders termed as neglected tropical diseases are particularly overlooked. Communicable tropical/sub-tropical diseases represent a diverse group of communicable disorders occurring in 149 countries, favored by tropical and sub-tropical conditions, affecting more than one billion people and imposing a dramatic societal and economic burden.MethodsA systematic review of the extant scholarly literature was carried out, searching in PubMed/MEDLINE and Scopus. The search string used included proper keywords, like big data, nontraditional data sources, social media, social networks, infodemiology, infoveillance, novel data streams (NDS, digital epidemiology, digital behavior, Google Trends, Twitter, Facebook, YouTube, Instagram, Pinterest, Ebola, Zika, dengue, Chikungunya, Chagas, and the other neglected tropical diseases.Results47 original, observational studies were included in the current systematic review: 1 focused on Chikungunya, 6 on dengue, 19 on Ebola, 2 on Malaria, 1 on Mayaro virus, 2 on West Nile virus, and 16 on Zika. Fifteen were dedicated on developing and validating forecasting techniques for real-time monitoring of neglected tropical diseases, while the remaining studies investigated public reaction to infectious outbreaks. Most studies explored a single nontraditional data source, with Twitter being the most exploited tool (25 studies.ConclusionEven though some studies have shown the feasibility of utilizing NDS as an effective tool for predicting epidemic outbreaks and disseminating accurate, high-quality information concerning neglected tropical diseases, some gaps should be properly underlined. Out of the 47 articles included, only 7 were focusing on neglected tropical diseases, while all the other covered communicable tropical/sub-tropical

Harnessing Big Data for Communicable Tropical and Sub-Tropical Disorders: Implications From a Systematic Review of the Literature.

Science.gov (United States)

Gianfredi, Vincenza; Bragazzi, Nicola Luigi; Nucci, Daniele; Martini, Mariano; Rosselli, Roberto; Minelli, Liliana; Moretti, Massimo

2018-01-01

According to the World Health Organization (WHO), communicable tropical and sub-tropical diseases occur solely, or mainly in the tropics, thriving in hot, and humid conditions. Some of these disorders termed as neglected tropical diseases are particularly overlooked. Communicable tropical/sub-tropical diseases represent a diverse group of communicable disorders occurring in 149 countries, favored by tropical and sub-tropical conditions, affecting more than one billion people and imposing a dramatic societal and economic burden. A systematic review of the extant scholarly literature was carried out, searching in PubMed/MEDLINE and Scopus. The search string used included proper keywords, like big data, nontraditional data sources, social media, social networks, infodemiology, infoveillance, novel data streams (NDS), digital epidemiology, digital behavior, Google Trends, Twitter, Facebook, YouTube, Instagram, Pinterest, Ebola, Zika, dengue, Chikungunya, Chagas, and the other neglected tropical diseases. 47 original, observational studies were included in the current systematic review: 1 focused on Chikungunya, 6 on dengue, 19 on Ebola, 2 on Malaria, 1 on Mayaro virus, 2 on West Nile virus, and 16 on Zika. Fifteen were dedicated on developing and validating forecasting techniques for real-time monitoring of neglected tropical diseases, while the remaining studies investigated public reaction to infectious outbreaks. Most studies explored a single nontraditional data source, with Twitter being the most exploited tool (25 studies). Even though some studies have shown the feasibility of utilizing NDS as an effective tool for predicting epidemic outbreaks and disseminating accurate, high-quality information concerning neglected tropical diseases, some gaps should be properly underlined. Out of the 47 articles included, only 7 were focusing on neglected tropical diseases, while all the other covered communicable tropical/sub-tropical diseases, and the main determinant of

Parks versus payments: reconciling divergent policy responses to biodiversity loss and climate change from tropical deforestation

International Nuclear Information System (INIS)

Busch, Jonah; Grantham, Hedley S

2013-01-01

Biodiversity loss and climate change both result from tropical deforestation, yet strategies to address biodiversity loss have focused primarily on protected areas while strategies to address climate change have focused primarily on carbon payments. Conservation planning research has focused largely on where to prioritize protected areas to achieve the greatest representation of species at viable levels. Meanwhile research on reducing emissions from deforestation and forest degradation (REDD+) has focused largely on how to design payments to achieve the greatest additional reduction in greenhouse gases relative to baseline rates. This divergence of strategies and research agendas may be attributed to four factors: rare species are more heterogeneously distributed than carbon; species are more difficult to measure and monitor than carbon; species are more sensitive to ecological processes and human disturbance than carbon; and people’s value for species diminishes beyond a threshold while their value for carbon storage does not. Conservation planning can achieve greater biodiversity benefits by adopting the concept of additionality from REDD+. REDD+ can achieve greater climate benefits by incorporating spatial prioritization from conservation planning. Climate and biodiversity benefits can best be jointly achieved from tropical forests by targeting the most additional actions to the most important places. These concepts are illustrated using data from the forests of Indonesia. (letter)

Atmospheric mixing ratios of methyl ethyl ketone (2-butanone in tropical, boreal, temperate and marine environments

Directory of Open Access Journals (Sweden)

A. M. Yáñez-Serrano

2016-09-01

Full Text Available Methyl ethyl ketone (MEK enters the atmosphere following direct emission from vegetation and anthropogenic activities, as well as being produced by the gas-phase oxidation of volatile organic compounds (VOCs such as n-butane. This study presents the first overview of ambient MEK measurements at six different locations, characteristic of forested, urban and marine environments. In order to understand better the occurrence and behaviour of MEK in the atmosphere, we analyse diel cycles of MEK mixing ratios, vertical profiles, ecosystem flux data, and HYSPLIT back trajectories, and compare with co-measured VOCs. MEK measurements were primarily conducted with proton-transfer-reaction mass spectrometer (PTR-MS instruments. Results from the sites under biogenic influence demonstrate that vegetation is an important source of MEK. The diel cycle of MEK follows that of ambient temperature and the forest structure plays an important role in air mixing. At such sites, a high correlation of MEK with acetone was observed (e.g. r2 = 0.96 for the SMEAR Estonia site in a remote hemiboreal forest in Tartumaa, Estonia, and r2 = 0.89 at the ATTO pristine tropical rainforest site in central Amazonia. Under polluted conditions, we observed strongly enhanced MEK mixing ratios. Overall, the MEK mixing ratios and flux data presented here indicate that both biogenic and anthropogenic sources contribute to its occurrence in the global atmosphere.

The Effect of Inquiry-Based Explorations in a Dynamic Geometry Environment on Sixth Grade Students' Achievements in Polygons

Science.gov (United States)

Erbas, Ayhan Kursat; Yenmez, Arzu Aydogan

2011-01-01

The purpose of this study was to investigate the effects of using a dynamic geometry environment (DGE) together with inquiry-based explorations on the sixth grade students' achievements in polygons and congruency and similarity of polygons. Two groups of sixth grade students were selected for this study: an experimental group composed of 66…

CDOM fluorescence as a proxy of DOC concentration in natural waters : a comparison of four contrasting tropical systems

OpenAIRE

Rochelle Newall, Emma; Hulot, F. D.; Janeau, Jean-Louis; Merroune, A.

2014-01-01

Chromophoric dissolved organic matter (CDOM) fluorescence or absorption is often proposed as a rapid alternative to chemical methods for the estimation of bulk dissolved organic carbon (DOC) concentration in natural waters. However, the robustness of this method across a wide range of systems remains to be shown. We measured CDOM fluorescence and DOC concentration in four tropical freshwater and coastal environments (estuary and coastal, tropical shallow lakes, water from the freshwater lens ...

Isotopes in tropical agriculture

Energy Technology Data Exchange (ETDEWEB)

NONE

1962-04-15

Ways in which the use of radioisotopes and radiation can help to improve the agriculture of tropical Africa were discussed by a panel of experts. The panel included scientists from Africa, Europe, and the United States, most of whom had had actual experience dealing with agricultural problems in various parts of tropical Africa. The experts agreed that radioisotopes and radiation might now be employed to particular advantage in tropical Africa to improve crop nutrition and combat insect pests. Other applications discussed were in the fields of hydrology, plant breeding and food preservation

Isotopes in tropical agriculture

International Nuclear Information System (INIS)

1962-01-01

Ways in which the use of radioisotopes and radiation can help to improve the agriculture of tropical Africa were discussed by a panel of experts. The panel included scientists from Africa, Europe, and the United States, most of whom had had actual experience dealing with agricultural problems in various parts of tropical Africa. The experts agreed that radioisotopes and radiation might now be employed to particular advantage in tropical Africa to improve crop nutrition and combat insect pests. Other applications discussed were in the fields of hydrology, plant breeding and food preservation

Riparian indicators of flow frequency in a tropical montante stream network

Science.gov (United States)

Andrew S. Pike; Frederick N. Scatena

2010-01-01

Many field indicators have been used to approximate the magnitude and frequency of flows in a variety of streams and rivers, yet due to a scarcity of long-term flow records in tropical mountain streams, little to no work has been done to establish such relationships between field features and the flow regime in these environments. Furthermore, the transition between...

Drifting algae and fish: Implications of tropical Sargassum invasion due to ocean warming in western Japan

Science.gov (United States)

Yamasaki, Mami; Aono, Mikina; Ogawa, Naoto; Tanaka, Koichiro; Imoto, Zenji; Nakamura, Yohei

2014-06-01

Evidence is accumulating that the invasion and extinction of habitat-forming seaweed species alters coastal community structure and ecological services, but their effects on the pelagic environment have been largely ignored. Thus, we examined the seasonal occurrence patterns of indigenous temperate and invasive tropical drifting algae and associated fish species every month for 2 years (2009-2011) in western Japan (Tosa Bay), where a rapid shift from temperate to tropical Sargassum species has been occurring in the coastal area since the late 1980s due to rising seawater temperatures. Of the 19 Sargassum species (31.6%) in drifting algae, we found that six were tropical species, whereas a study in the early 1980s found only one tropical species among 12 species (8.3%), thereby suggesting an increase in the proportion of tropical Sargassum species in drifting algae during the last 30 years. Drifting temperate algae were abundantly present from late winter to summer, whereas tropical algal clumps occurred primarily during summer. In the warm season, fish assemblages did not differ significantly between drifting temperate and tropical algae, suggesting the low host-algal specificity of most fishes. We also found that yellowtail juveniles frequently aggregated with drifting temperate algae from late winter to spring when drifting tropical algae were unavailable. Local fishermen collect these juveniles for use as aquaculture seed stock; therefore, the occurrence of drifting temperate algae in early spring is important for local fisheries. These results suggest that the further extinction of temperate Sargassum spp. may have negative impacts on the pelagic ecosystem and associated regional fisheries.

Limited carbon and biodiversity co-benefits for tropical forest mammals and birds.

Science.gov (United States)

Beaudrot, Lydia; Kroetz, Kailin; Alvarez-Loayza, Patricia; Amaral, Eda; Breuer, Thomas; Fletcher, Christine; Jansen, Patrick A; Kenfack, David; Lima, Marcela Guimarães Moreira; Marshall, Andrew R; Martin, Emanuel H; Ndoundou-Hockemba, Mireille; O'Brien, Timothy; Razafimahaimodison, Jean Claude; Romero-Saltos, Hugo; Rovero, Francesco; Roy, Cisquet Hector; Sheil, Douglas; Silva, Carlos E F; Spironello, Wilson Roberto; Valencia, Renato; Zvoleff, Alex; Ahumada, Jorge; Andelman, Sandy

2016-06-01

The conservation of tropical forest carbon stocks offers the opportunity to curb climate change by reducing greenhouse gas emissions from deforestation and simultaneously conserve biodiversity. However, there has been considerable debate about the extent to which carbon stock conservation will provide benefits to biodiversity in part because whether forests that contain high carbon density in their aboveground biomass also contain high animal diversity is unknown. Here, we empirically examined medium to large bodied ground-dwelling mammal and bird (hereafter "wildlife") diversity and carbon stock levels within the tropics using camera trap and vegetation data from a pantropical network of sites. Specifically, we tested whether tropical forests that stored more carbon contained higher wildlife species richness, taxonomic diversity, and trait diversity. We found that carbon stocks were not a significant predictor for any of these three measures of diversity, which suggests that benefits for wildlife diversity will not be maximized unless wildlife diversity is explicitly taken into account; prioritizing carbon stocks alone will not necessarily meet biodiversity conservation goals. We recommend conservation planning that considers both objectives because there is the potential for more wildlife diversity and carbon stock conservation to be achieved for the same total budget if both objectives are pursued in tandem rather than independently. Tropical forests with low elevation variability and low tree density supported significantly higher wildlife diversity. These tropical forest characteristics may provide more affordable proxies of wildlife diversity for future multi-objective conservation planning when fine scale data on wildlife are lacking.

Tropical cyclogenesis in a tropical wave critical layer: easterly waves

Directory of Open Access Journals (Sweden)

T. J. Dunkerton

2009-08-01

Full Text Available The development of tropical depressions within tropical waves over the Atlantic and eastern Pacific is usually preceded by a "surface low along the wave" as if to suggest a hybrid wave-vortex structure in which flow streamlines not only undulate with the waves, but form a closed circulation in the lower troposphere surrounding the low. This structure, equatorward of the easterly jet axis, is identified herein as the familiar critical layer of waves in shear flow, a flow configuration which arguably provides the simplest conceptual framework for tropical cyclogenesis resulting from tropical waves, their interaction with the mean flow, and with diabatic processes associated with deep moist convection. The recirculating Kelvin cat's eye within the critical layer represents a sweet spot for tropical cyclogenesis in which a proto-vortex may form and grow within its parent wave. A common location for storm development is given by the intersection of the wave's critical latitude and trough axis at the center of the cat's eye, with analyzed vorticity centroid nearby. The wave and vortex live together for a time, and initially propagate at approximately the same speed. In most cases this coupled propagation continues for a few days after a tropical depression is identified. For easterly waves, as the name suggests, the propagation is westward. It is shown that in order to visualize optimally the associated Lagrangian motions, one should view the flow streamlines, or stream function, in a frame of reference translating horizontally with the phase propagation of the parent wave. In this co-moving frame, streamlines are approximately equivalent to particle trajectories. The closed circulation is quasi-stationary, and a dividing streamline separates air within the cat's eye from air outside. The critical layer equatorward of the easterly jet axis is important to tropical cyclogenesis because its cat's eye provides (i a region of

Spatio-temporal variability of aerosols in the tropics relationship with atmospheric and oceanic environments

Science.gov (United States)

Zuluaga-Arias, Manuel D.

2011-12-01

of surface temperature, atmospheric wind, geopotential height, outgoing longwave radiation, water vapor and precipitation together with the climatology of aerosols provide insight on how the variables interact. Different modes of variability, especially in intraseasonal time scales appear as strong modulators of the aerosol distribution. In particular, we investigate how two modes of variability related to the westward propagating synoptic African Easterly Waves of the Tropical Atlantic Ocean affect the horizontal and vertical structure of the environment. The statistical significance of these two modes is tested with the use of two different spectral techniques. The pattern of propagation of aerosol load shows good correspondence with the progression of the atmospheric and oceanic conditions suitable for dust mobilization over the Atlantic Ocean. We present extensions to previous studies related with dust variability over the Atlantic region by evaluating the performance of the long period satellite aerosol retrievals in determining modes of aerosol variability. Results of the covariability between aerosols-environment motivate the use of statistical regression models to test the significance of the forecasting skill of daily AOD time series. The regression models are calibrated using atmospheric variables as predictors from the reanalysis variables. The results show poor forecasting skill with significant error growing after the 3 rd day of the prediction. It is hypothesized that the simplicity of linear models results in an inability to provide a useful forecast.

Evolution of a Planktonic Foraminifer during Environmental Changes in the Tropical Oceans.

Science.gov (United States)

Ujiié, Yurika; Ishitani, Yoshiyuki

2016-01-01

Ecological adaptation to environmental changes is a strong driver of evolution, enabling speciation of pelagic plankton in the open ocean without the presence of effective physical barriers to gene flow. The tropical ocean environment, which plays an important role in shaping marine biodiversity, has drastically and frequently changed since the Pliocene. Nevertheless, the evolutionary history of tropical pelagic plankton has been poorly understood, as phylogeographic investigations are still in the developing state and paleontological approaches are insufficient to obtain a sequential record from the deep-sea sediments. The planktonic foraminifer Pulleniatina obliquiloculata is widely distributed in the tropical area throughout the world's oceans, and its phylogeography is well established. It is thus one of the best candidates to examine how past environmental changes may have shifted the spatial distribution and affected the diversification of tropical pelagic plankton. Such an examination requires the divergence history of the planktonic foraminifers, yet the gene marker (partial small subunit (SSU) rDNA) previously used for phylogeographic studies was not powerful enough to achieve a high accuracy in estimating the divergence times. The present study focuses on improving the precision of divergence time estimates for the splits between sibling species (genetic types) of planktonic foraminifers by increasing the number of genes as well as the number of nucleotide bases used for molecular clock estimates. We have amplified the entire coding regions of two ribosomal RNA genes (SSU rDNA and large subunit (LSU) rDNA) of three genetic types of P. obliquiloculata and two closely related species for the first time and applied them to the Bayesian relaxed clock method. The comparison of the credible intervals of the four datasets consisting either of sequences of the partial SSU rDNA, the complete SSU rDNA, LSU rDNA, or a combination of both genes (SSU+LSU) clearly

Sensitivity of South American tropical climate to Last Glacial Maximum boundary conditions: focus on teleconnections with tropics and extratropics (Invited)

Science.gov (United States)

Khodri, M.; Kageyama, M.; Roche, D. M.

2009-12-01

Proxy data over tropical latitudes for the Last Glacial Maximum (LGM) has been interpreted as a southward shift of the Inter Tropical Convergence Zone (ITCZ) and so far linked to a mechanism analogous to the modern day “meridional-mode” in the Atlantic Ocean. Here we have explored alternative mechanisms, related to the direct impact of the LGM global changes in the dry static stability on tropical moist deep convection. We have used a coupled ocean-atmosphere model capable of capturing the thermodynamical structure of the atmosphere and the tropical component of the Hadley and Walker circulations. In each experiment, we have applied either all the LGM forcings, or the individual contributions of greenhouse gases (GHG) concentrations, ice sheet topography and/or albedo to explore the hydrological response over tropical latitudes with a focus on South America. The dominant forcing for the LGM tropical temperature and precipitation changes is found to be due to the reduced GHG, through the direct effect of reduced radiative heating (Clausius-Clapeyron relationship). The LGM GHG is also responsible for increased extra-tropical static stability which strengthens the Hadley Cell. Stronger subsidence over northern tropics then produces an amplification of the northern tropics drying initially due to the direct cooling effect. The land ice sheet is also able to promote the Hadley cell feedback mostly via the topographic effect on the extra-tropical dry static stability and on the position of the subtropical jets. Our results therefore suggest that the communication between the extratropics and the tropics is tighter during LGM and does not necessarily rely on the “meridional-mode” mechanism. The Hadley cell response is constrained by the requirement that diabatic heating in the tropics balances cooling in subtropics. We show that such extratropics-tropics dependence is stronger at the LGM because of the stronger perturbation of northern extra tropical thermal and

Erodibility of cement-stabilized tropical soils in highway engineering in Togo

International Nuclear Information System (INIS)

Eklu-Natey, T.E.D.

1992-01-01

This work contains a methodical study on the suceptibility to weather of cement-stabilized tropical soils of Togo by simulating on the one hand the climatic conditions of the original surroundings and on the other hand the variations occuring in situ of the degree of saturation and compaction. The chosen tests ensure for the first time a simple execution and at the same time reproducible numerical values of the results achieved. From results of the slaking, erosion, adhesion, durability and swelling tests clear parameters and classification criteria were derived which help to forecast the susceptibility to weather of soils in tropical climates. A method for the determination of the reaction to water of soils is proposed consisting of a particular process of derivation and interpretation of the consistency value for a given swelling rate. Moreover a possibility is recommended with which the time-consuming and expensive mineralogical analyses which were frequently used in the past for torpical soils can be avoided. The proposed evaluation criteria provides civil engineers working in permanently moist, arid or intermittently moist tropical regions with practical and theoretical bases for the estimation of the erodibility of soils. (orig./BBR) [de

Animal Health in the Tropics

Directory of Open Access Journals (Sweden)

M.R. Jainudeen

1996-01-01

Full Text Available Most developing countries in Africa and Asia are located in the tropics (23° north and south of the equator. The poor productivity of ruminants in these countries is mostly due to inadequate nutrition, infectious diseases, low rates of reproduction, poor genotype, high ambient temperatures and socioeconomic constraints. In addition to infectious diseases which have long since been eradicated or brought under control in developed countries, there are diseases unique to the tropical environment. In the past, the diagnosis of most diseases was based on serological tests. The enzyme-linked immunosorbent assay (ELISA, a rapid method of identifying viral and bacterial infections, is contributing to the eradication or control of most epidemic diseases which inflict high mortality. Less attention has; however, been given to subclinical diseases which adversely affect reproduction, growrh rates and reduced performance (draught power, milk and meat. The interaction of veterinary epidemiology and agricultural economics has helped epidemiologists and veterinarians to focus on the economic importance of animal diseases. The emerging trends in animal health include new diagnostic methods using DNA probes, new vaccines, sustainable parasite control schemes and herd health monitoring. The study of infectious diseases of veterinary importance will continue to he supported by modern techniques of molecular biology. Veterinary curricula should emphasis both animal health and production in the context of current national development occurring in the livestock sector.

Old tropical botanical collections

DEFF Research Database (Denmark)

Friis, Ib

2017-01-01

The early history of botanical collections is reviewed, with particular emphasis on old collections from the tropics. The information available about older and newer botanical collections from the tropics was much improved after World War Two, including better lists of validly published names, more...

Principals' Perceptions of Social Networking Access, Its Relationship to Cyberbullying, the Importance of Student Achievement, and the School Environment

Science.gov (United States)

Townsel, Andrae

2015-01-01

The purpose of this study was to examine the principals' perceptions of social networking access and its relationship to cyberbullying, the importance of student achievement, and the school environment across the United States. This research provides some evidence on how principals perceive and understand the threat of cyberbullying and its…

Possible climatic impact of tropical deforestation

Energy Technology Data Exchange (ETDEWEB)

Potter, G L; Ellsaesser, H W; MacCracken, M C; Luther, F M

1975-12-25

A computer model of climate changes resulting from removal of tropical rain forests to increase arable acreage is described. A chain of consequences is deduced from the model which begins with deforestation and ends with overall global cooling and a reduction in precipitation. A model of the global water budget shows that the reduction in precipitation is accompanied by cooling in the upper tropical troposphere, a lowering of the tropical tropopause, and a warming of the lower tropical stratosphere. (HLW)

Tropical forests. Nettai no shinrin

Energy Technology Data Exchange (ETDEWEB)

Yamada, I [Kyoto Univ., Kyoto (Japan)

1991-11-05

It was in 1950s when felling of tropical forests started in earnest, in 1970s felling of forest trees in Southeast Asia reached its peak and the destnation of exportation of most of them was Japan. Besides, among the present overseas development assistance projects (ODA) of Japan, her role to be played in connection with tropical forests is not small and its funds, which surpass by far the budget for forestry of the United Nations Food and Agriculture Organization (FAO), are aiding cooperation projects on forestry in many places in the world. Nevertheless, in Japan, the understanding of tropical forests is insufficient and its realities have not been known. In this article, based on the experience and knowledge of the author who stayed in Kalimantan, various kinds of problems concerning tropical forests are explained, the realities are introduced on information, well trained people, funds and philosophy which are far short in pursuance of the problems of tropical forests. Furthermore, as the issues hereafter, such proposals on tropical forests are made as protection of natural forests, planned operation in respecting self renewal ability of the secondary forests and afforestation of alang-alang grassy plains resulted from the failure of burning felled trees and grasses for making the land arable. 1 ref..

Volatile sulfur compounds in tropical fruits

Directory of Open Access Journals (Sweden)

Robert J. Cannon

2018-04-01

Full Text Available Global production and demand for tropical fruits continues to grow each year as consumers are enticed by the exotic flavors and potential health benefits that these fruits possess. Volatile sulfur compounds (VSCs are often responsible for the juicy, fresh aroma of tropical fruits. This poses a challenge for analytical chemists to identify these compounds as most often VSCs are found at low concentrations in most tropical fruits. The aim of this review is to discuss the extraction methods, enrichment techniques, and instrumentation utilized to identify and quantify VSCs in natural products. This will be followed by a discussion of the VSCs reported in tropical and subtropical fruits, with particular attention to the odor and taste attributes of each compound. Finally, the biogenesis and enzymatic formation of specific VSCs in tropical fruits will be highlighted along with the contribution each possesses to the aroma of their respective fruit. Keywords: Tropical fruits, Volatile sulfur compounds, Extraction methods

[Tropical sprue (author's transl)].

Science.gov (United States)

Gras, C; Chapoy, P; Aubry, P

1981-01-01

Tropical sprue is a disease of the small intestine characterized by a malabsorption syndrome with a subtotal or partial mucosal atrophy. It is observed in Asia and Central America. It appears to be rare in Africa but its real frequency is unknown as small bowel biopsys are not routinely done. Bacterial overgrowth as well as giardiasis may be trigger factors of the disease the pathogenesis of which is still incompletely understood. The disease beginning as chronic diarrhea is later on characterized by an aphtoïd stomatitis and a macrocytic anemia. Treatment with antibiotics and folic acid is efficient and has a diagnostic value. If treatment is started lately, vitamin B 12 is then also necessary. In any intestinal syndrome observed in tropical areas without an ascertained etiologic diagnosis, peroral biopsie of the small intestine is requested. However, with the use of pediatric endoscope it will be possible to appreciate the respective incidence of tropical sprue and asymptomatic tropical sprue in Africa South of the Sahara.

Securing tropical forest carbon

DEFF Research Database (Denmark)

Scharlemann, Jörn P. W.; Kapos, Valerie; Campbell, Alison

2010-01-01

Forest loss and degradation in the tropics contribute 6-17% of all greenhouse gas emissions. Protected areas cover 217.2 million ha (19.6%) of the world's humid tropical forests and contain c. 70.3 petagrams of carbon (Pg C) in biomass and soil to 1 m depth. Between 2000 and 2005, we estimate...... that 1.75 million ha of forest were lost from protected areas in humid tropical forests, causing the emission of 0.25-0.33 Pg C. Protected areas lost about half as much carbon as the same area of unprotected forest. We estimate that the reduction of these carbon emissions from ongoing deforestation...... in protected sites in humid tropical forests could be valued at USD 6,200-7,400 million depending on the land use after clearance. This is >1.5 times the estimated spending on protected area management in these regions. Improving management of protected areas to retain forest cover better may be an important...

Predicting Intra-Individual Academic Achievement Trajectories of Adolescents Nested in Class Environment: Influence of motivation, implicit theory of intelligence, self-esteem and parenting

Directory of Open Access Journals (Sweden)

Isabelle Roskam

2007-05-01

Full Text Available In a longitudinal study conducted on 1130 adolescents (557 male and 573 female in the 1st-6th grades from Belgian secondary schools, we tested the influence of individual factors (motivational constructs, implicit theory of intelligence and self-esteem and environmental determinants (parenting and class environment of academic achievement (grades in mathematics, language arts and GPA at three points in time. Using hierarchical linear models, we observed a decrease of grade over the course of the study, reciprocal relations between motivational constructs, self-esteem and academic achievement, a strong positive impact of supportive parenting and a moderate influence of class environment.

The correlation of urban heat island in tropical middle-class housing

Science.gov (United States)

Wazir, Zuber Angkasa

2017-11-01

A very limited number of green and sustainable construction studies have explored factors related to Urban Heat Island (UHI) in tropical middle-class housing. This paper aimed to investigate the correlation of Urban Heat Island in tropical middle-class housing in three urban housing for middle-class residents of Palembang, which were Taman Sari Kenten, TOP Jakabaring, and Talang Kelapa. Samples consisted of 125 Taman Sari Kenten housing, 27 Talang Kelapa housing, and 12 TOP Jakabaring housing. Independent variables were the resident density, socioeconomic status, house location, roof type, green area ratio, weather, time, air conditioner, pro-environment institution, and NEP scale. The Analytic method included correlation and regression. We identified that all housing had different UHI profiles where Taman Sari Kenten had the highest UHI (4.17 K), followed by Talang Kelapa (2.66 K) and TOP Jakabaring (0.66 K) against temperature in measuring station nearby, owned by BMKG (National Meteorological Station). UHI correlated with the resident density, roof type, green area ratio, weather, time, and air conditioner. The results should add to the design of ideal housing in the tropical climate for middle-class residents, focusing on its ability to mitigate Urban Heat Island.

Healthy Eating and Academic Achievement

Centers for Disease Control (CDC) Podcasts

This podcast highlights the evidence that supports the link between healthy eating and improved academic achievement. It also identifies a few actions to support a healthy school nutrition environment to improve academic achievement.

Potential impacts of global warming on Australia's unique tropical biodiversity and implications for tropical biodiversity in general

International Nuclear Information System (INIS)

Hilbert, David W

2007-01-01

Full text: Full text: Globally, forest clearing is often thought to be the greatest threat to biodiversity in the tropics, and rates of clearing are certainly highest there, particularly in tropical South-East Asia. Climate change in the tropics has been less studied in tropical regions than in temperate, boreal or arctic ecosystems. However, modelling studies in Australian rainforests indicate that climate change may be a particularly significant threat to the long-term preservation of the biodiversity of tropical, rainforest biodiversity. Our research has shown that global warming can have a particularly strong impact on the biodiversity of mountainous tropical regions, including the Wet Tropics of north-east Queensland. Here, the mountain tops and higher tablelands are relatively cool islands in a sea of warmer climates. These species-rich islands, mostly limited in their biodiversity by warm interglacial periods, are separated from each other by the warmer valleys and form a scattered archipelago of habitat for organisms that are unable to survive and reproduce in warmer climates. Many of the endemic Australian Wet Tropics species live only in these cooler regions. Similar situations occur throughout south-east Asia and in the highlands of the Neotropics. Unfortunately, these upland and highland areas represent the majority of biodiversity conservation areas because they are less suitable for clearing for agriculture. This presentation will summarise research about the potential impacts of climate change on the biodiversity in Australia's rainforests, the potential implications for tropical biodiversity in general and discuss the limitations of these projections and the need for further research that could reduce uncertainties and inform effective adaptation strategies

Distribution and fate of HCH isomers and DDT metabolites in a tropical environment-case study Cameron Highlands-Malaysia.

Science.gov (United States)

Saadati, Naghmeh; Abdullah, Md Pauzi; Zakaria, Zuriati; Rezayi, Majid; Hosseinizare, Nader

2012-11-07

The serious impact effects of persistent organic pollutants such as organochlorine pesticides, especially dichlorodiphenyltrichloroethane family (DDTs) and hexachlorocyclohexane isomers (HCHs) have been causing widespread concern, despite effective control on their manufacturing, agricultural and vector practices. In that, in addition to the previous global limitations on DDTs usage, α-HCH, β-HCH and lindane have also became an on-going topic of global relevance based on the latest Stockholm Convention list on 10th of May 2009. Concentrations of dichlorodiphenyltrichloroethane family (DDTs) and hexachlorocyclohexane isomers (HCHs) were determined by GC-ECD in Cameron Highlands, the main vegetables and flowers farming area in Malaysia as an agricultural tropical environment. A total of 112 surface water and sediment samples at eight points were collected along the main rivers in the area namely Telom and Bertam in the dry and wet seasons of 2011. Total concentration of HCH isomers ranged from not detected to 25.03 ng/L in the water (mean of 5.55 ±6.0 ng/L), while, it ranged from 0.002 to 59.17 ng/g (mean of 8.06±9.39 ng/g) in the sediment. Total concentration of DDT and its metabolites in the water samples varied from not detected to 8.0 ng/L (mean of 0.90±1.66 ng/g), whereas, it was in the range of 0.025 to 23.24 ng/g (mean of 2.55±4.0 ng/g) in the surface sediment samples. The ratio of HCHs and DDTs composition indicated an obvious historical usage and new inputs of these pesticides. Among alpha, beta, gamma and delta isomers of HCH, gamma was the most dominant component in the sediment and water as well. Some seasonal variations in the level of selected pesticides were noted. The results illustrate distribution, behaviour and fate of HCHs, and DDTs have closely connected with topological and meteorological properties of the area beyond their chemical characterizations. The features of environmental circumstances exceed one or more of these characters in

pH dominates variation in tropical soil archaeal diversity and community structure.

Science.gov (United States)

Tripathi, Binu M; Kim, Mincheol; Lai-Hoe, Ang; Shukor, Nor A A; Rahim, Raha A; Go, Rusea; Adams, Jonathan M

2013-11-01

Little is known of the factors influencing soil archaeal community diversity and composition in the tropics. We sampled soils across a range of forest and nonforest environments in the equatorial tropics of Malaysia, covering a wide range of pH values. DNA was PCR-amplified for the V1-V3 region of the 16S rRNA gene, and 454-pyrosequenced. Soil pH was the best predictor of diversity and community composition of Archaea, being a stronger predictor than land use. Archaeal OTU richness was highest in the most acidic soils. Overall archaeal abundance in tropical soils (determined by qPCR) also decreased at higher pH. This contrasts with the opposite trend previously found in temperate soils. Thaumarcheota group 1.1b was more abundant in alkaline soils, whereas group 1.1c was only detected in acidic soils. These results parallel those found in previous studies in cooler climates, emphasizing niche conservatism among broad archaeal groups. Among the most abundant operational taxonomic units (OTUs), there was clear evidence of niche partitioning by pH. No individual OTU occurred across the entire range of pH values. Overall, the results of this study show that pH plays a major role in structuring tropical soil archaeal communities. © 2013 Federation of European Microbiological Societies. Published by John Wiley & Sons Ltd. All rights reserved.

Introduction: Environment and Society in Contemporary Latin America

NARCIS (Netherlands)

de Castro, F.; Hogenboom, B.; Baud, M.; de Castro, F.; Hogenboom, B.; Baud, M.

2016-01-01

Societal change in Latin America is intimately related to nature and natural resources. In this resource-rich region, nature–society relations provide both opportunities and challenges in achieving more fair, equitable and sustainable development. Nearly half of the world’s tropical forests are

Influence of upwelling and tropical environments on the breeding development of the intertidal barnacle Tetraclita stalactifera (Lamarck, 1818

Directory of Open Access Journals (Sweden)

Luis Felipe Skinner

2011-12-01

Full Text Available Cabo Frio, with its unique oceanographic conditions, is an important biogeographical transitional region between tropical and sub-tropical waters. This is due to the presence of upwelling from the Central Water of the South Atlantic (CWSA, and the presence of tropical waters from the Brazilian Current (BC and Coastal Water (CW. The intertidal barnacle, Tetraclita stalactifera, and its brooding stages were analyzed to correlate environmental conditions with reproductive development. Two thermal contrasting sites were chosen: Ponta da Cabeça (PC, which is under the influence of seasonal upwelling, and Ponta da Fortaleza (PF which experiences tropical influences. At each site, T. stalactifera specimens were collected monthly and their egg lamellae conditions classified into stages from 0 (empty to IV (ready to release. Our results show a seasonal effect on brooding at the PC site and a continuous development at the PF site. Nauplii larval availability also followed this trend. Differences between the sites could be due to ecological differences related to water temperature and the ecological-physiological response of the barnacles to these differences.Cabo Frio, devido suas características oceanográficas, causado pela é uma importante região biogeográfica transicional entre águas tropicais e sub-tropicais. Isto é ressurgência da Água Central do Atlântico Sul (ACAS e a presença de águas tropicais da Corrente do Brasil (CB e de Água Costeira (AC. A craca do mediolitoral Tetraclita stalactifera e seus estágios de maturação larval foram analisados a fim de serem correlacionados às condições ambientais. Dois locais com características termais contrastantes foram escolhidos: a Ponta da Cabeça (PC, que está sobre influência sazonal da ressurgência e a Ponta da Fortaleza (PF, sob influência da água tropical. Em cada local, indivíduos de T. stalactifera foram coletados mensalmente e a condição de suas lamellas ovígeras aferida

Soil organic carbon dynamics in pastures established after deforestation in the humid tropics of Costa Rica

NARCIS (Netherlands)

Veldkamp, E.

1993-01-01

Currently, rates of deforestation in the tropics are probably higher than ever before in the past. As a consequence, changes in the earth's physical and chemical environments are proceeding at unprecedented rates. Increasing atmospheric concentrations of CO

Pan-tropical monitoring of deforestation

International Nuclear Information System (INIS)

Achard, F; DeFries, R; Eva, H; Hansen, M; Mayaux, P; Stibig, H-J

2007-01-01

This paper reviews the technical capabilities for monitoring deforestation from a pan-tropical perspective in response to the United Nations Framework Convention on Climate Change (UNFCCC) process, which is studying the technical issues surrounding the ability to reduce greenhouse gas emissions from deforestation in developing countries. The successful implementation of such policies requires effective forest monitoring systems that are reproducible, provide consistent results, meet standards for mapping accuracy, and can be implemented from national to pan-tropical levels. Remotely sensed data, supported by ground observations, are crucial to such efforts. Recent developments in global to regional monitoring of forests can contribute to reducing the uncertainties in estimates of emissions from deforestation. Monitoring systems at national levels in developing countries can also benefit from pan-tropical and regional observations, mainly by identifying hot spots of change and prioritizing areas for monitoring at finer spatial scales. A pan-tropical perspective is also required to ensure consistency between different national monitoring systems. Data sources already exist to determine baseline periods in the 1990s as historical reference points. Key requirements for implementing such monitoring programs, both at pan-tropical and at national scales, are international commitment of resources to increase capacity, coordination of observations to ensure pan-tropical coverage, access to free or low-cost data, and standardized, consensus protocols for data interpretation and analysis

Use of remote sensing for monitoring deforestation in tropical and subtropical latitudes

Science.gov (United States)

Talbot, J. J.; Pettinger, Lawrence R.

1981-01-01

Of the three types of remotely sensed data discussed here, Landsat data offers the greatest potential for monitoring broad changes in extensive tropical forest environments because of its low-cost, synoptic, repetitive coverage. Scientists from developing countries can choose from a variety of Landsat data classification techniques, thus enabling each country to satisfy limitations on available funding, trained personnel, and equipment.

How the redox state of tobacco 'Bel-W3' is modified in response to ozone and other environmental factors in a sub-tropical area?

International Nuclear Information System (INIS)

Dias, Ana P.L.; Dafre, Marcelle; Rinaldi, Mirian C.S.; Domingos, Marisa

2011-01-01

This study intended to determine whether the redox state in plants of Nicotiana tabacum 'Bel-W3' fluctuates in response to the environmental factors in a sub-tropical area contaminated by ozone (Sao Paulo, SE - Brazil) and which environmental factors are related to this fluctuation, discussing their biomonitoring efficiency. We comparatively evaluated the indicators of redox state (ascorbic acid, glutathione, superoxide dismutase, ascorbate peroxidase, and glutathione reductase) and leaf injury in 17 field experiments performed in 2008. The redox state was explained by the combined effects of chronic levels of O 3 and meteorological variables 4-6 days prior to the plant sampling. Moderate leaf injury was observed in most cases. The redox state of tobacco decreases few days after their placement in the sub-tropical environment, causing them to become susceptible to oxidative stress imposed by chronic doses of O 3 . Its bioindicator efficiency would not be diminished in such levels of atmospheric contamination. - Research highlights: → Nicotiana tabacum 'Bel-W3' is potentially a bioindicator of O 3 in the sub-tropics. → However, it is unknown if its redox state would affect its bioindicator performance under sub-tropical environmental conditions. → This study revealed that the redox state of tobacco decreases few days after their placement in the sub-tropical environment, causing them to become susceptible to oxidative stress imposed by chronic doses of O 3 . → Therefore, its bioindicator efficiency would not be diminished in such levels of atmospheric contamination. → However, the bioindicator efficiency N. tabacum 'Bel-W3' for biomonitoring O 3 should be regionally modeled in the sub-tropics, based on both its redox state and on the flux of O 3 through stomata, in response to the varying micro-meteorological conditions that govern both physiological processes. - The bioindicator efficiency of tobacco plants is not restrained under chronic doses of O 3 in

Tropical forest-transition landscapes: a portfolio for studying people, tree crops and agro-ecological change in context

NARCIS (Netherlands)

Dewi, S.; Noordwijk, van M.; Zulkarnain, Muhammad Thoha; Dwiputra, Adrian; Hyman, Glenn; Prabhu, R.; Gitz, V.; Nasi, Robert

2017-01-01

Nudging the development trajectory of tropical landscapes towards sustainability requires a global commitment and policies that take diverse contexts and forest transitions into account. Out-scaling and upscaling landscape-level actions to achieve sustainable development goals globally need to be

Comparisons of urban and rural heat stress conditions in a hot–humid tropical city

Directory of Open Access Journals (Sweden)

Ahmed A. Balogun

2010-11-01

Full Text Available Background: In recent years the developing world, much of which is located in the tropical countries, has seen dramatic growth of its urban population associated with serious degradation of environmental quality. Climate change is producing major impacts including increasing temperatures in these countries that are considered to be most vulnerable to the impact of climate change due to inadequate public health infrastructure and low income status. However, relevant information and data for informed decision making on human health and comfort are lacking in these countries. Objective: The aim of this paper is to study and compare heat stress conditions in an urban (city centre and rural (airport environments in Akure, a medium-sized tropical city in south-western Nigeria during the dry harmattan season (January–March of 2009. Materials and methods: We analysed heat stress conditions in terms of the mean hourly values of the thermohygrometric index (THI, defined by simultaneous in situ air temperature and relative humidity measurements at both sites. Results: The urban heat island (UHI exists in Akure as the city centre is warmer than the rural airport throughout the day. However, the maximum UHI intensity occurs at night between 1900 and 2200 hours local time. Hot conditions were predominant at both sites, comfortable conditions were only experienced in the morning and evenings of January at both sites, but the rural area has more pleasant morning and evenings and less of very hot and torrid conditions. January has the lowest frequency of hot and torrid conditions at both sites, while March and February has the highest at the city centre and the airport, respectively. The higher frequencies of high temperatures in the city centre suggest a significant heat stress and health risk in this hot humid environment of Akure. Conclusions: More research is needed to achieve better understanding of the seasonal variation of indoor and outdoor heat stress

Potential of airborne radar to support the assessment of land cover in a tropical rain forest environment

NARCIS (Netherlands)

Sanden, van der J.J.; Hoekman, D.H.

1999-01-01

The potential of airborne radar systems as tools for collecting information in support of the assessment of tropical primary forests and derived cover types was examined. SAR systems operating with high spatial resolutions and different wavelengths (i.e., X-, C-, L- and P-band) acquired data in

Agro-Science Journal of Tropical Agriculture, Food, Environment ...

African Journals Online (AJOL)

PC USER

through chemical means apart from being expensive sometimes result in the poisoning of cowpea and environmental toxicity (Olakojo et al., 2007). This suggests the need for alternative management method that would protect the crop and also the environment (Oluwafemi et al. 2013). It is in this direction that this research.

Bovine reproduction in tropical environment

International Nuclear Information System (INIS)

Jimenez Lopez, J.

2001-01-01

In this document it has met relating data to the reproduction of bovine and their handling for the man that it can serve as norms to judge reproductive efficiency but always view in the aspect of the nutritious, climatic circumstances and of handling under which met. Under the previous description one can say that the fertility is the resultant of the interaction among the inheritance, the means and the handling, they vary in particular for each region and property. The fertility can be good, regulate or bad in the measure in that the factors that intervene. The environmental effect on the reproductive processes of the cow represents 80 percent of the variation factors and they include climate, effect of the light, effect of the temperature, effect of the nutritious contribution, effect of psychological factors: the loss of the tendency to the seasonal reproduction is in fact an answer from the animals to its association with the man. The influence of the environment and the feeding of the animals are more intense in the females than in the males, being evidenced that the reproduction control is under the influence hormonal joint with the nutrition. An appropriate nutrition is prerequisite for the beginning of the sexual maturation with an appropriate weight and corporal condition. It is also described the effect and the relationship of the energy contribution about the fertility, the restart of the ovarian activity, its cause of the continuation of the interval childbirth-conception, silent ovulation, organic ancestry and interval among childbirths

Parvalbumin--the major tropical fish allergen.

Science.gov (United States)

Lim, Dawn Li-Chern; Neo, Keng Hwee; Yi, Fong Cheng; Chua, Kaw Yan; Goh, Denise Li-Meng; Shek, Lynette Pei-Chi; Giam, Yoke Chin; Van Bever, Hugo P S; Lee, Bee Wah

2008-08-01

Fish allergy is common in countries where consumption is high. Asian nations are amongst the world's largest consumers of fish but the allergen profiles of tropical fish are unknown. This study sought to evaluate the allergenicity of four commonly consumed tropical fish, the threadfin (Polynemus indicus), Indian anchovy (Stolephorus indicus), pomfret (Pampus chinensis) and tengirri (Scomberomorus guttatus). Immunoglobulin E (IgE) cross-reactivity with parvalbumin of cod fish (Gad c 1), the major fish allergen, was also studied. Detection of tropical fish and cod specific-IgE was performed by UniCap assay, and skin prick tests were also carried out. The IgE-binding components of tropical fish were identified using IgE immunoblot techniques, and cross-reactivity with Gad c 1 was assessed by ELISA inhibition and IgE immunoblot inhibition. Clinically, nine of 10 patients studied were allergic to multiple fish. All patients exhibited detectable specific-IgE to cod fish (10 of 10 skin prick test positive, eight of 10 UniCap assay positive) despite lack of previous exposure. The major allergen of the four tropical fish was the 12-kDa parvalbumin. IgE cross-reactivity of these allergens to Gad c 1 was observed to be moderate to high in the tropical fish studied. Parvalbumins are the major allergens in commonly consumed tropical fish. They are cross-reactive with each other as well as with Gad c 1. Commercial tests for cod fish appear to be sufficient for the detection of tropical fish specific-IgE.

Phylogenetic structure in tropical hummingbird communities

DEFF Research Database (Denmark)

Graham, Catherine H; Parra, Juan L; Rahbek, Carsten

2009-01-01

How biotic interactions, current and historical environment, and biogeographic barriers determine community structure is a fundamental question in ecology and evolution, especially in diverse tropical regions. To evaluate patterns of local and regional diversity, we quantified the phylogenetic...... composition of 189 hummingbird communities in Ecuador. We assessed how species and phylogenetic composition changed along environmental gradients and across biogeographic barriers. We show that humid, low-elevation communities are phylogenetically overdispersed (coexistence of distant relatives), a pattern...... that is consistent with the idea that competition influences the local composition of hummingbirds. At higher elevations communities are phylogenetically clustered (coexistence of close relatives), consistent with the expectation of environmental filtering, which may result from the challenge of sustaining...

2011 and 2012 Early Careers Achievement Awards: Placental programming: how the maternal environment can impact placental function.

Science.gov (United States)

Vonnahme, K A; Lemley, C O; Shukla, P; O'Rourke, S T

2013-06-01

Proper establishment of the placenta is important for fetal survival; however, placental adaptations to inadequate maternal nutrition or other stressors are imperative for fetal growth to be optimal. The effects of maternal nutritional status and activity level on placental vascular function and uteroplacental blood flows are important to understand as improper placental function leads to reduced growth of the fetus. In environments where fetal growth can be compromised, potential therapeutics may augment placental function and delivery of nutrients to improve offspring performance during postnatal life. Factors that could enhance placental function include supplementation of specific nutrients, such as protein, hormone supplements, such as indolamines, and increased activity levels of the dam. To understand the mechanism of how the maternal environment can impact uterine or umbilical blood flows, assessment of placental vascular reactivity has been studied in several large animal models. As we begin to understand how the maternal environment impacts uterine and umbilical blood flows and other uteroplacental hemodynamic parameters, development of management methods and therapeutics for proper fetal growth can be achieved.

Integrating Green Building Criteria Into Housing Design Processes Case Study: Tropical Apartment At Kebon Melati, Jakarta

Science.gov (United States)

Farid, V. L.; Wonorahardjo, S.

2018-05-01

The implementation of Green Building criteria is relatively new in architectural practice, especially in Indonesia. Consequently, the integration of these criteria into design process has the potential to change the design process itself. The implementation of the green building criteria into the conventional design process will be discussed in this paper. The concept of this project is to design a residential unit with a natural air-conditioning system. To achieve this purpose, the Green Building criteria has been implemented since the beginning of the design process until the detailing process on the end of the project. Several studies was performed throughout the design process, such as: (1) Conceptual review, where several professionally proved theories related to Tropical Architecture and passive design are used for a reference, and (2) Computer simulations, such as Computational Fluid Dynamics (CFD) and wind tunnel simulation, used to represent the dynamic response of the surrounding environment towards the building. Hopefully this paper may become a reference for designing a green residential building.

1997 Annual Tropical Cyclone Report

National Research Council Canada - National Science Library

Dillon, C

1997-01-01

.... Separate bulletins are issued for the Western Pacific and the Indian Ocean. TROPICAL CYCLONE FORMATION ALERT - Defines a specific area when synoptic, satellite, or other germane data indicate development of a significant tropical cyclone (TC...

Test Operations Procedure (TOP) 01-1-020 Tropical Regions Environmental Considerations

Science.gov (United States)

2013-02-08

to exude tannins , sugars, and other natural plant products, which may support microbial growth and corrosion processes. 2.2 Test Site Severity...Containers in Humid Environments, US Army Tropic Test Center, TECOM Project No. 7-C0-PB5-TT1-004, 1978. 16. A Technical Analysis to Identify Ideal...1973. 37. MIL-STD-810G, Test Method Standard, Environmental Engineering Considerations and Laboratory Tests, 2008. 38. A Technical Analysis

A comparative assessment of heavy metal accumulation in soft parts and byssus of mussels from subarctic, temperate, subtropical and tropical marine environments

International Nuclear Information System (INIS)

Szefer, P.; Fowler, S.W.; Ikuta, K.; Osuna, F. Paez; Ali, A.A.; Kim, B.-S.; Fernandes, H.M.; Belzunce, M.-J.; Guterstam, B.; Kunzendorf, H.; Wolowicz, M.; Hummel, H.; Deslous-Paoli, M.

2006-01-01

Existing data on metal concentrations in mussels from subarctic, temperate, subtropical and tropical waters were analyzed using multivariate statistics in order to assess regional variations in metal contamination. Potential errors were reduced by only analyzing data from surveys that employed the same protocols, analytical methodologies and analysts. Factor analysis demonstrated that mussels inhabiting extremely contaminated areas (e.g. from Japanese and Swedish metallurgy sources) could be separated from mussels from other contaminated areas, and that metals such as Cd, Pb, Cu and Zn could be used to identify heavily contaminated samples while Co, Fe, Cr and Ni concentrations were good markers for exposure to inputs from different industrial sources. Furthermore byssus, like soft tissue, selectively and sensitively reflects variations of certain metal concentrations in ambient waters and thus serves as a reliable biomonitor for these contaminants in a variety of coastal and estuarine areas. - Byssus of mytilids, like soft tissues can be used as efficient biomonitor for heavy metals in the marine environment

A comparative assessment of heavy metal accumulation in soft parts and byssus of mussels from subarctic, temperate, subtropical and tropical marine environments

Energy Technology Data Exchange (ETDEWEB)

Szefer, P. [Department of Food Sciences, Medical University of Gdansk, Al. Gen. J. Hallera 107, PL 80-416 Gdansk (Poland)]. E-mail: pszef@amg.gda.pl; Fowler, S.W. [IAEA Marine Environment Laboratory, 4 Quai Antoine 1er, MC-98000 (Monaco); Ikuta, K. [Laboratory of Aquatic Environment and Ecology, Department of Fisheries, Faculty of Agriculture, Miyazaki University, 889-21 Miyazaki (Japan); Osuna, F. Paez [Institute of Marine Sciences and Limnology, Mazatlan Station, National Autonomous University of Mexico, Mazatlan 82000, Sinaloa (Mexico); Ali, A.A. [Faculty of Science, Arts and Education, University of Aden, PO Box 6014, Khormaksar, Aden (Yemen); Kim, B.-S. [School of Earth and Environmental Science, Seoul National University, 56-1 Shillimdong, 151-742 (Korea, Republic of); Fernandes, H.M. [Instituto de Radioprotecao e Dosimetria, Cz. Postal 37 750 - CEP: 22642-970, Rio de Janeiro (Brazil); Belzunce, M.-J. [Instituto Tecnnologico Pesquero y Alimentario, Dpto de Oceanografia y Medio Ambiente Marino, Herrera Kaia, Portualdea z/g, 20110 Pasaia (Gipuzkoa) (Spain); Guterstam, B. [Stensund Ecological Center, 61991 Trosa, Sweden and Global Water Partnership Secretariat, Hantverkargatan 5, SE-112 21 Stockholm (Sweden); Kunzendorf, H. [Gamma Dating Center (GDC), Institute of Geography, University of Copenhagen, Oster Voldgage 10 DK-1350 Copenhagen K (Denmark); Wolowicz, M. [Laboratory of Estuarine Ecology, Institute of Oceanography, University of Gdansk, Al. Pilsudskiego 46, 81-378, Gdynia (Poland); Hummel, H. [Centre for Estuarine and Marine Ecology, Netherlands Institute of Ecology, Korringaweg 7, 4401 NT Yerseke (Netherlands); Deslous-Paoli, M. [IFREMER, Unite Ecologie Conchylicole, 1, rue Jean Vilar, 34200 Sete (France)

2006-01-15

Existing data on metal concentrations in mussels from subarctic, temperate, subtropical and tropical waters were analyzed using multivariate statistics in order to assess regional variations in metal contamination. Potential errors were reduced by only analyzing data from surveys that employed the same protocols, analytical methodologies and analysts. Factor analysis demonstrated that mussels inhabiting extremely contaminated areas (e.g. from Japanese and Swedish metallurgy sources) could be separated from mussels from other contaminated areas, and that metals such as Cd, Pb, Cu and Zn could be used to identify heavily contaminated samples while Co, Fe, Cr and Ni concentrations were good markers for exposure to inputs from different industrial sources. Furthermore byssus, like soft tissue, selectively and sensitively reflects variations of certain metal concentrations in ambient waters and thus serves as a reliable biomonitor for these contaminants in a variety of coastal and estuarine areas. - Byssus of mytilids, like soft tissues can be used as efficient biomonitor for heavy metals in the marine environment.

Corrosion study of steels exposed over five years to the humid tropical atmosphere of Panama

Energy Technology Data Exchange (ETDEWEB)

Jaén, Juan A., E-mail: juan.jaen@up.ac.pa [Departamento de Química Física, Edificio de Laboratorios Científicos-VIP (Panama); Iglesias, Josefina [Laboratorio de Análisis Industriales y Ciencias Ambientales (Panama)

2017-11-15

The results of assessing five-year corrosion of low-carbon and conventional weathering steels exposed to the Panamanian tropical atmosphere is presented. Two different test sites, one in Panama City: 5 km from the shoreline of the Pacific Ocean, and another in the marine environment of Fort Sherman, Caribbean coast of Panama; namely, Fort Sherman Coastal site: 100 m from coastline. The corrosion products, formed in the skyward and earthward faces in the studied tropical environment, were mainly identified using room temperature and low temperature (15 K) Mössbauer spectroscopy, and ATR-FTIR. In all samples, lepidocrocite (γ-FeOOH) and goethite (α-FeOOH) were the main constituents. Some maghemite (γ-Fe{sub 2}O{sub 3}), was also identified in Tocumen by Mössbauer spectroscopy and traces of feroxyhyte (δ-FeOOH) using ATR-FTIR. The corrosion rate values obtained are discussed in light of the atmospheric exposure conditions and atmospheric pollutants.

Diversity of Ammonia Oxidizing Archaea in Tropical Compost Systems

Directory of Open Access Journals (Sweden)

Vidya eDe Gannes

2012-07-01

Full Text Available Composting is widely used to transform waste materials into valuable agricultural products. In the tropics, large quantities of agricultural wastes could be potentially useful in agriculture after composting. However, while microbiological processes of composts in general are well established, relatively little is known about microbial communities that may be unique to these in tropical systems, particularly nitrifiers. The recent discovery of ammonia oxidizing archaea (AOA has changed the paradigm of nitrification being initiated solely by ammonia oxidizing bacteria. In the present study, AOA abundance and diversity was examined in composts produced from combinations of plant waste materials common in tropical agriculture (rice straw, sugar cane bagasse, coffee hulls, which were mixed with either cow- or sheep-manure. The objective was to determine how AOA abundance and diversity varied as a function of compost system and time, the latter being a contrast between the start of the compost process (mesophilic phase and the finished product (mature phase. The results showed that AOA were relatively abundant in composts of tropical agricultural wastes, and significantly more so than were the ammonia-oxidizing bacteria. Furthermore, while the AOA communities in the composts were predominatly group I.1b, the communities were diverse and exhibited structures that diverged between compost types and phases. These patterns could be taken as indicators of the ecophysiological diversity in the soil AOA (groub I.1b, in that significantly different AOA communties developed when exposed to varying physico-chemical environments. Nitrification patterns and levels differed in the composts which, for the mature material, could have signifcant effects on its performanc as a plant growth medium. Thus, it will also be important to determine the association of AOA (and diversity in their communities with nitrification in these systems.

Carbon stock corridors to mitigate climate change and promote biodiversity in the tropics

Science.gov (United States)

Jantz, Patrick; Goetz, Scott; Laporte, Nadine

2014-02-01

A key issue in global conservation is how biodiversity co-benefits can be incorporated into land use and climate change mitigation activities, particularly those being negotiated under the United Nations to reduce emissions from tropical deforestation and forest degradation. Protected areas have been the dominant strategy for tropical forest conservation and they have increased substantially in recent decades. Avoiding deforestation by preserving carbon stored in vegetation between protected areas provides an opportunity to mitigate the effects of land use and climate change on biodiversity by maintaining habitat connectivity across landscapes. Here we use a high-resolution data set of vegetation carbon stock to map corridors traversing areas of highest biomass between protected areas in the tropics. The derived corridors contain 15% of the total unprotected aboveground carbon in the tropical region. A large number of corridors have carbon densities that approach or exceed those of the protected areas they connect, suggesting these are suitable areas for achieving both habitat connectivity and climate change mitigation benefits. To further illustrate how economic and biological information can be used for corridor prioritization on a regional scale, we conducted a multicriteria analysis of corridors in the Legal Amazon, identifying corridors with high carbon, high species richness and endemism, and low economic opportunity costs. We also assessed the vulnerability of corridors to future deforestation threat.

Disease ecology, health and the environment: a framework to account for ecological and socio-economic drivers in the control of neglected tropical diseases.

Science.gov (United States)

Garchitorena, A; Sokolow, S H; Roche, B; Ngonghala, C N; Jocque, M; Lund, A; Barry, M; Mordecai, E A; Daily, G C; Jones, J H; Andrews, J R; Bendavid, E; Luby, S P; LaBeaud, A D; Seetah, K; Guégan, J F; Bonds, M H; De Leo, G A

2017-06-05

Reducing the burden of neglected tropical diseases (NTDs) is one of the key strategic targets advanced by the Sustainable Development Goals. Despite the unprecedented effort deployed for NTD elimination in the past decade, their control, mainly through drug administration, remains particularly challenging: persistent poverty and repeated exposure to pathogens embedded in the environment limit the efficacy of strategies focused exclusively on human treatment or medical care. Here, we present a simple modelling framework to illustrate the relative role of ecological and socio-economic drivers of environmentally transmitted parasites and pathogens. Through the analysis of system dynamics, we show that periodic drug treatments that lead to the elimination of directly transmitted diseases may fail to do so in the case of human pathogens with an environmental reservoir. Control of environmentally transmitted diseases can be more effective when human treatment is complemented with interventions targeting the environmental reservoir of the pathogen. We present mechanisms through which the environment can influence the dynamics of poverty via disease feedbacks. For illustration, we present the case studies of Buruli ulcer and schistosomiasis, two devastating waterborne NTDs for which control is particularly challenging.This article is part of the themed issue 'Conservation, biodiversity and infectious disease: scientific evidence and policy implications'. © 2017 The Author(s).

Electrochemical behaviour of aluminum alloy containing various stanum concentration tested in tropical seawater

International Nuclear Information System (INIS)

Siti Radiah Mohd Kamarudin; Muhamad Daud; Mohd Shariff Satar

2004-01-01

A study has been carried out to investigate the electrochemical behaviour of sacrificial anodes with different Sh concentration in tropical seawater environment. In this work, samples of Aluminum alloy with the addition of Sn in a range of 1. 0% - 1. 7% were tested in tropical seawater at room temperature. Tafel technique was used to produce a graph of the measured current versus potential for each different Sh concentration of aluminum alloy. The results show that the variation in alloy compositions affected the values of corrosion rate, corrosion current density and potential compared to alloy without Sn content. Furthermore, it was found that small addition of Sn successfully increased aluminum ion dissolution into seawater by producing a higher value of corrosion current density and corrosion rate. (Author)

Teleconnections of the tropical Atlantic to the tropical Indian and Pacific Oceans. A review of recent findings

Energy Technology Data Exchange (ETDEWEB)

Wang Chunzai [NOAA Atlantic Oceanographic and Meteorological Lab., Miami, FL (United States); Kucharski, Fred; Barimalala, Rondrotiana [The Abdus Salam International Centre for Theoretical Physics, Earth System Physics, Section Trieste (Italy); Bracco, Annalisa [School of Earth and Atmospheric Sciences Georgia, Inst. of Tech., Atlanta, GA (United States)

2009-08-15

Recent studies found that tropical Atlantic variability may affect the climate in both the tropical Pacific and Indian Ocean basins, possibly modulating the Indian summer monsoon and Pacific ENSO events. A warm tropical Atlantic Ocean forces a Gill-Matsuno-type quadrupole response with a low-level anticyclone located over India that weakens the Indian monsoon circulation, and vice versa for a cold tropical Atlantic Ocean. The tropical Atlantic Ocean can also induce changes in the Indian Ocean sea surface temperatures (SSTs). especially along the coast of Africa and in the western side of the Indian basin. Additionally, it can influence the tropical Pacific Ocean via an atmospheric teleconnection that is associated with the Atlantic Walker circulation. Although the Pacific El Nino does not contemporaneously correlate with the Atlantic Nino, anomalous warming or cooling of the two equatorial oceans can form an inter-basin SST gradient that induces surface zonal wind anomalies over equatorial South America and other regions in both ocean basins. The zonal wind anomalies act as a bridge linking the two ocean basins, and in turn reinforce the inter-basin SST gradient through the atmospheric Walker circulation and oceanic processes. Thus, a positive feedback seems to exist for climate variability of the tropical Pacific-Atlantic Oceans and atmospheric system, in which the inter-basin SST gradient is coupled to the overlying atmospheric wind. (orig.)

Ocean barrier layers' effect on tropical cyclone intensification.

Science.gov (United States)

Balaguru, Karthik; Chang, Ping; Saravanan, R; Leung, L Ruby; Xu, Zhao; Li, Mingkui; Hsieh, Jen-Shan

2012-09-04

Improving a tropical cyclone's forecast and mitigating its destructive potential requires knowledge of various environmental factors that influence the cyclone's path and intensity. Herein, using a combination of observations and model simulations, we systematically demonstrate that tropical cyclone intensification is significantly affected by salinity-induced barrier layers, which are "quasi-permanent" features in the upper tropical oceans. When tropical cyclones pass over regions with barrier layers, the increased stratification and stability within the layer reduce storm-induced vertical mixing and sea surface temperature cooling. This causes an increase in enthalpy flux from the ocean to the atmosphere and, consequently, an intensification of tropical cyclones. On average, the tropical cyclone intensification rate is nearly 50% higher over regions with barrier layers, compared to regions without. Our finding, which underscores the importance of observing not only the upper-ocean thermal structure but also the salinity structure in deep tropical barrier layer regions, may be a key to more skillful predictions of tropical cyclone intensities through improved ocean state estimates and simulations of barrier layer processes. As the hydrological cycle responds to global warming, any associated changes in the barrier layer distribution must be considered in projecting future tropical cyclone activity.

Mycorrhizas and tropical soil fertility

NARCIS (Netherlands)

Cardoso, I.M.; Kuyper, T.W.

2006-01-01

Major factors that constrain tropical soil fertility and sustainable agriculture are low nutrient capital, moisture stress, erosion, high P fixation, high acidity with aluminium toxicity, and low soil biodiversity. The fragility of many tropical soils limits food production in annual cropping

Pan tropical biomass equations for Mexico's dry forests

Directory of Open Access Journals (Sweden)

José Návar

2014-12-01

Full Text Available This study reports a set of robust regional M-tree allometric equations for Mexico's tropical dry forests and their application to a forest inventory dataset for the States of Durango and Sinaloa, Mexico. Calculated M data from 15 reported equations were fitted, applied and validated for regional and global models. Proposed theoretical models, empirically derived equations, as well as global and local reported equations were fitted and applied to calculated M-tree data using wood specific gravity, diameter at breast height, and top height as exogenous variables. Empirically-derived, computer-based equations assessed the M-tree evaluations slightly better than the theoretical, the global and the local models. However, the theoretical models projected compatible M-tree values and deserve further attention once wood specific gravity data are collected in the field. Using the best fit equation, mean M plot density values of 30, 41 and 35 Mg ha-1 were estimated from 57 plots (1,600 m² each, 217 plots (1,000 m² each and 166 plots (1,000 m² each in the tropical dry forests of the States of Durango, Tiniaquis and Vado Hondo (Sinaloa, respectively. The large sample size, the richness of the tested allometric models, the economic and ecological importance of this data-source, and the spatial coverage of these equations made this dataset uniquely useful for biomass, charcoal, and other bio-energy estimations, as well as for understanding the inherent heterogeneity of the stand-structure in dynamic tropical forest environments.

Tropical vegetation evidence for rapid sea level changes associated with Heinrich Events

Energy Technology Data Exchange (ETDEWEB)

Gonzalez, Catalina; Dupont, Lydie M, E-mail: catalina@uni-bremen.d, E-mail: dupont@uni-bremen.d [MARUM - Centre for Marine Environmental Sciences, University of Bremen, Leobener Strasse, D-28359 Germany (Germany)

2010-03-15

A Cariaco Basin pollen record shows the development of tropical salt marshes during marine isotope stage 3. Rapid and abrupt expansions of salt marsh vegetation in tropical South America are associated with north Atlantic Heinrich Events stadials (HE-stadials). Intervals of salt marsh expansion have an internal structure, which consists of a recurrent alternation of species that starts with pollen increments of Chenopodiaceae, that are followed by increments of grasses, and subsequently by increments of Cyperaceae. This pattern suggests a successional process that is determined by the close relationship between sea-level and plant community dynamics. The salt tolerant Chenopodiaceae, indicate hypersaline intertidal environments, which were most likely promoted by extremely dry atmospheric conditions. Rapid sea-level rise characterizes the onset of HE-stadials, causing the continued recruitment of pioneer species, which are the only ones tolerating rapid rates of disturbance. Once sea-level rise decelerates, marsh plants are able to trap and stabilize sediments, favouring the establishment of more competitive species. These results add to the scarce knowledge on the dynamics of tropical salt marsh ecosystems, and provide independent paleoclimatic evidence on sea-level changes following Antarctic climate variability.

Current status of tropical fruit breeding and genetics for three tropical fruit species cultivated in Japan: pineapple, mango, and papaya

Science.gov (United States)

Ogata, Tatsushi; Yamanaka, Shinsuke; Shoda, Moriyuki; Urasaki, Naoya; Yamamoto, Toshiya

2016-01-01

Tropical fruit crops are predominantly produced in tropical and subtropical developing countries, but some are now grown in southern Japan. Pineapple (Ananas comosus), mango (Mangifera indica) and papaya (Carica papaya) are major tropical fruits cultivated in Japan. Modern, well-organized breeding systems have not yet been developed for most tropical fruit species. Most parts of Japan are in the temperate climate zone, but some southern areas such as the Ryukyu Islands, which stretch from Kyushu to Taiwan, are at the northern limits for tropical fruit production without artificial heating. In this review, we describe the current status of tropical fruit breeding, genetics, genomics, and biotechnology of three main tropical fruits (pineapple, mango, and papaya) that are cultivated and consumed in Japan. More than ten new elite cultivars of pineapple have been released with improved fruit quality and suitability for consumption as fresh fruit. New challenges and perspectives for obtaining high fruit quality are discussed in the context of breeding programs for pineapple. PMID:27069392

Design of autonomous sensor nodes for remote soil monitoring in tropical banana plantation

Science.gov (United States)

Tiausas, Francis Jerome G.; Co, Jerelyn; Macalinao, Marc Joseph M.; Guico, Maria Leonora; Monje, Jose Claro; Oppus, Carlos

2017-09-01

Determining the effect of Fusarium oxysporum f. sp. cubense Tropical Race 4 on various soil parameters is essential in modeling and predicting its occurrence in banana plantations. One way to fulfill this is through a sensor network that will continuously and automatically monitor environmental conditions at suspect locations for an extended period of time. A wireless sensor network was developed specifically for this purpose. This sensor network is capable of measuring soil acidity, moisture, temperature, and conductivity. The designed prototype made use of off-the-shelf Parrot Flower Power soil sensor, pH sensor, Bluno Beetle, battery, and 3D-printed materials, catering specifically to the conditions of tropical banana plantations with consideration for sensor node size, communication, and power. Sensor nodes were tested on both simulated tropical environments and on an actual banana plantation in San Jose, General Santos City, Philippines. Challenges were resolved through iterative design and development of prototypes. Several tests including temperature and weather resilience, and structural stress tests were done to validate the design. Findings showed that the WSN nodes developed for this purpose are resilient to high tropical temperatures for up to 12 hours of continuous exposure, are able to withstand compressive forces of up to 8880.6 N, and can reliably collect data automatically from the area 47.96% of the time at an hourly frequency under actual field conditions.

Indian deepsea environment experiment (index): Achievements and applications

Digital Repository Service at National Institute of Oceanography (India)

Sharma, R.

impact experiment. Evaluation of impact of simulated disturbance in the benthic environment shows vertical mixing of sediment, lateral distribution of particles, changes in geochemical and biochemical conditions as well as reduction in biomass...

Um modelo para a determinação do equilíbrio térmico de bovinos em ambientes tropicais A heat balance model for cattle in tropical environments

Directory of Open Access Journals (Sweden)

Roberto Gomes da Silva

2000-08-01

Full Text Available Uma equação com base na teoria da transferência térmica foi apresentada para estimativa da termólise em bovinos expostos a um ambiente tropical especificado por temperatura e umidade do ar, radiação solar e vento. As variáveis do animal (taxa de sudação, temperatura retal, frequência respiratória, temperatura da superfície cutânea, coloração do pelame e peso corporal foram consideradas em conjunto com as variáveis ambientais (temperatura do ar e umidade, radiação solar, velocidade do vento e temperatura do globo. A equação permite a predição de: (1 o nível de termogênese metabólica necessária para equilibrar as perdas térmicas sob condições ambientais especificadas; (2 a combinação de fatores ambientais que proporcionam determinado fluxo de calor entre um dado animal e o seu ambiente.An equation based on heat transfer theory was presented to estimate the rate of heat loss from cattle exposed to a tropical environment, specified by the air temperature, humidity, solar radiation, and wind speed. The animals' variables (sweating rate, rectal temperature, respiratory rate, surface temperature, haircoat color, and body weight were considered together with environmental variables (air temperature and humidity, solar radiation, wind speed, and globe temperature. The equation allows the prediction of (a the metabolic heat production level necessary to balance heat losses under specified environmental conditions; (b the combination of environmental factors that provide a determined heat flux between a given animal and its environment.

Mineralogic maturity of modern sand along a high-energy tropical coast: Baixada de Jacarepaguá, Rio de Janeiro, Brazil

Science.gov (United States)

Savage, K. M.; de Cesero, P.; Potter, P. E.

Quarts arenites overlying crystalline basement are fairly common in the geologic record. A modern analog is provided in coastal Brazil where a small tropical lowland is bordered by abrupt, Precambrian granitic and gneissic mountains of the Serra do Mar. Nine different sedimentary environments were sampled, 57 sands were studied petrographically, and 8 complete chemical analyses were made. Here, arkosic river sands pass seaward into well defined, quartz-rich, stranded beach ridges and pure quartz arenites of the modern beach and shelf. Strong inshore wave power combined with tropical weathering seem to be the principal factors for this change. Tropical weathering also converted surface samples of arkosic Pliocene fan deposits into residual quartz arenites. Implications for the paleotectonic and paleoclimatic interpretation of ancient sandstones are also discussed.

Interactive Effects of Temperature and UV Radiation on Photosynthesis of Chlorella Strains from Polar, Temperate and Tropical Environments: Differential Impacts on Damage and Repair

Science.gov (United States)

Wong, Chiew-Yen; Teoh, Ming-Li; Phang, Siew-Moi; Lim, Phaik-Eem; Beardall, John

2015-01-01

Global warming and ozone depletion, and the resulting increase of ultraviolet radiation (UVR), have far-reaching impacts on biota, especially affecting the algae that form the basis of the food webs in aquatic ecosystems. The aim of the present study was to investigate the interactive effects of temperature and UVR by comparing the photosynthetic responses of similar taxa of Chlorella from Antarctic (Chlorella UMACC 237), temperate (Chlorella vulgaris UMACC 248) and tropical (Chlorella vulgaris UMACC 001) environments. The cultures were exposed to three different treatments: photosynthetically active radiation (PAR; 400–700 nm), PAR plus ultraviolet-A (320–400 nm) radiation (PAR + UV-A) and PAR plus UV-A and ultraviolet-B (280–320 nm) radiation (PAR + UV-A + UV-B) for one hour in incubators set at different temperatures. The Antarctic Chlorella was exposed to 4, 14 and 20°C. The temperate Chlorella was exposed to 11, 18 and 25°C while the tropical Chlorella was exposed to 24, 28 and 30°C. A pulse-amplitude modulated (PAM) fluorometer was used to assess the photosynthetic response of microalgae. Parameters such as the photoadaptive index (Ek) and light harvesting efficiency (α) were determined from rapid light curves. The damage (k) and repair (r) rates were calculated from the decrease in ΦPSIIeff over time during exposure response curves where cells were exposed to the various combinations of PAR and UVR, and fitting the data to the Kok model. The results showed that UV-A caused much lower inhibition than UV-B in photosynthesis in all Chlorella isolates. The three isolates of Chlorella from different regions showed different trends in their photosynthesis responses under the combined effects of UVR (PAR + UV-A + UV-B) and temperature. In accordance with the noted strain-specific characteristics, we can conclude that the repair (r) mechanisms at higher temperatures were not sufficient to overcome damage caused by UVR in the Antarctic Chlorella strain

Interactive Effects of Temperature and UV Radiation on Photosynthesis of Chlorella Strains from Polar, Temperate and Tropical Environments: Differential Impacts on Damage and Repair.

Directory of Open Access Journals (Sweden)

Chiew-Yen Wong

Full Text Available Global warming and ozone depletion, and the resulting increase of ultraviolet radiation (UVR, have far-reaching impacts on biota, especially affecting the algae that form the basis of the food webs in aquatic ecosystems. The aim of the present study was to investigate the interactive effects of temperature and UVR by comparing the photosynthetic responses of similar taxa of Chlorella from Antarctic (Chlorella UMACC 237, temperate (Chlorella vulgaris UMACC 248 and tropical (Chlorella vulgaris UMACC 001 environments. The cultures were exposed to three different treatments: photosynthetically active radiation (PAR; 400-700 nm, PAR plus ultraviolet-A (320-400 nm radiation (PAR + UV-A and PAR plus UV-A and ultraviolet-B (280-320 nm radiation (PAR + UV-A + UV-B for one hour in incubators set at different temperatures. The Antarctic Chlorella was exposed to 4, 14 and 20°C. The temperate Chlorella was exposed to 11, 18 and 25°C while the tropical Chlorella was exposed to 24, 28 and 30°C. A pulse-amplitude modulated (PAM fluorometer was used to assess the photosynthetic response of microalgae. Parameters such as the photoadaptive index (Ek and light harvesting efficiency (α were determined from rapid light curves. The damage (k and repair (r rates were calculated from the decrease in ΦPSIIeff over time during exposure response curves where cells were exposed to the various combinations of PAR and UVR, and fitting the data to the Kok model. The results showed that UV-A caused much lower inhibition than UV-B in photosynthesis in all Chlorella isolates. The three isolates of Chlorella from different regions showed different trends in their photosynthesis responses under the combined effects of UVR (PAR + UV-A + UV-B and temperature. In accordance with the noted strain-specific characteristics, we can conclude that the repair (r mechanisms at higher temperatures were not sufficient to overcome damage caused by UVR in the Antarctic Chlorella strain

Unprecedented drought over tropical South America in 2016: significantly under-predicted by tropical SST.

Science.gov (United States)

Erfanian, Amir; Wang, Guiling; Fomenko, Lori

2017-07-19

Tropical and sub-tropical South America are highly susceptible to extreme droughts. Recent events include two droughts (2005 and 2010) exceeding the 100-year return value in the Amazon and recurrent extreme droughts in the Nordeste region, with profound eco-hydrological and socioeconomic impacts. In 2015-2016, both regions were hit by another drought. Here, we show that the severity of the 2015-2016 drought ("2016 drought" hereafter) is unprecedented based on multiple precipitation products (since 1900), satellite-derived data on terrestrial water storage (since 2002) and two vegetation indices (since 2004). The ecohydrological consequences from the 2016 drought are more severe and extensive than the 2005 and 2010 droughts. Empirical relationships between rainfall and sea surface temperatures (SSTs) over the tropical Pacific and Atlantic are used to assess the role of tropical oceanic variability in the observed precipitation anomalies. Our results indicate that warmer-than-usual SSTs in the Tropical Pacific (including El Niño events) and Atlantic were the main drivers of extreme droughts in South America, but are unable to explain the severity of the 2016 observed rainfall deficits for a substantial portion of the Amazonia and Nordeste regions. This strongly suggests potential contribution of non-oceanic factors (e.g., land cover change and CO2-induced warming) to the 2016 drought.

Anaerobic decomposition of switchgrass by tropical soil-derived feedstock-adapted consortia.

Science.gov (United States)

DeAngelis, Kristen M; Fortney, Julian L; Borglin, Sharon; Silver, Whendee L; Simmons, Blake A; Hazen, Terry C

2012-01-01

Tropical forest soils decompose litter rapidly with frequent episodes of anoxic conditions, making it likely that bacteria using alternate terminal electron acceptors (TEAs) play a large role in decomposition. This makes these soils useful templates for improving biofuel production. To investigate how TEAs affect decomposition, we cultivated feedstock-adapted consortia (FACs) derived from two tropical forest soils collected from the ends of a rainfall gradient: organic matter-rich tropical cloud forest (CF) soils, which experience sustained low redox, and iron-rich tropical rain forest (RF) soils, which experience rapidly fluctuating redox. Communities were anaerobically passed through three transfers of 10 weeks each with switchgrass as a sole carbon (C) source; FACs were then amended with nitrate, sulfate, or iron oxide. C mineralization and cellulase activities were higher in CF-FACs than in RF-FACs. Pyrosequencing of the small-subunit rRNA revealed members of the Firmicutes, Bacteroidetes, and Alphaproteobacteria as dominant. RF- and CF-FAC communities were not different in microbial diversity or biomass. The RF-FACs, derived from fluctuating redox soils, were the most responsive to the addition of TEAs, while the CF-FACs were overall more efficient and productive, both on a per-gram switchgrass and a per-cell biomass basis. These results suggest that decomposing microbial communities in fluctuating redox environments are adapted to the presence of a diversity of TEAs and ready to take advantage of them. More importantly, these data highlight the role of local environmental conditions in shaping microbial community function that may be separate from phylogenetic structure. After multiple transfers, we established microbial consortia derived from two tropical forest soils with different native redox conditions. Communities derived from the rapidly fluctuating redox environment maintained a capacity to use added terminal electron acceptors (TEAs) after multiple

How the redox state of tobacco 'Bel-W3' is modified in response to ozone and other environmental factors in a sub-tropical area?

Energy Technology Data Exchange (ETDEWEB)

Dias, Ana P.L.; Dafre, Marcelle; Rinaldi, Mirian C.S. [Instituto de Botanica, Caixa Postal 3005, 01061-970 Sao Paulo, SP (Brazil); Domingos, Marisa, E-mail: mmingos@superig.com.b [Instituto de Botanica, Caixa Postal 3005, 01061-970 Sao Paulo, SP (Brazil)

2011-02-15

This study intended to determine whether the redox state in plants of Nicotiana tabacum 'Bel-W3' fluctuates in response to the environmental factors in a sub-tropical area contaminated by ozone (Sao Paulo, SE - Brazil) and which environmental factors are related to this fluctuation, discussing their biomonitoring efficiency. We comparatively evaluated the indicators of redox state (ascorbic acid, glutathione, superoxide dismutase, ascorbate peroxidase, and glutathione reductase) and leaf injury in 17 field experiments performed in 2008. The redox state was explained by the combined effects of chronic levels of O{sub 3} and meteorological variables 4-6 days prior to the plant sampling. Moderate leaf injury was observed in most cases. The redox state of tobacco decreases few days after their placement in the sub-tropical environment, causing them to become susceptible to oxidative stress imposed by chronic doses of O{sub 3}. Its bioindicator efficiency would not be diminished in such levels of atmospheric contamination. - Research highlights: Nicotiana tabacum 'Bel-W3' is potentially a bioindicator of O{sub 3} in the sub-tropics. However, it is unknown if its redox state would affect its bioindicator performance under sub-tropical environmental conditions. This study revealed that the redox state of tobacco decreases few days after their placement in the sub-tropical environment, causing them to become susceptible to oxidative stress imposed by chronic doses of O{sub 3}. Therefore, its bioindicator efficiency would not be diminished in such levels of atmospheric contamination. However, the bioindicator efficiency N. tabacum 'Bel-W3' for biomonitoring O{sub 3} should be regionally modeled in the sub-tropics, based on both its redox state and on the flux of O{sub 3} through stomata, in response to the varying micro-meteorological conditions that govern both physiological processes. - The bioindicator efficiency of tobacco plants is not

Induced mutation in tropical fruit trees

Energy Technology Data Exchange (ETDEWEB)

NONE

2009-05-15

This publication is based on an FAO/IAEA coordinated research project (CRP) and provides insight into the application of induced mutation and in vitro techniques for the improvement of well known fruit trees such as citrus, mango, avocado and papaya, as well as more exotic fruit trees such as litchi, annona, jujube, carambola, pitanga and jaboticaba. The latter are of particular importance due to their adaptation to harsh environments and their high potential as basic food and micronutrient providers for populations in poorer and more remote regions. The findings of the CRP show that application of radiation induced mutation techniques in tropical and subtropical fruit trees can contribute to improving nutritional balance food security, and to enhancing the economic status of growers.

Induced mutation in tropical fruit trees

International Nuclear Information System (INIS)

2009-05-01

This publication is based on an FAO/IAEA coordinated research project (CRP) and provides insight into the application of induced mutation and in vitro techniques for the improvement of well known fruit trees such as citrus, mango, avocado and papaya, as well as more exotic fruit trees such as litchi, annona, jujube, carambola, pitanga and jaboticaba. The latter are of particular importance due to their adaptation to harsh environments and their high potential as basic food and micronutrient providers for populations in poorer and more remote regions. The findings of the CRP show that application of radiation induced mutation techniques in tropical and subtropical fruit trees can contribute to improving nutritional balance food security, and to enhancing the economic status of growers

Spoil characteristics and vegetation development of an age series of mine spoils in a dry tropical environment

Energy Technology Data Exchange (ETDEWEB)

Jha, A K; Singh, J S [Banaras Hindu University, Varanasi (India). Dept. of Botany

1991-12-01

A series of coal mine spoils (5,10,12,16 and 20-yr old) in a dry tropical environment was sampled to assess the changes with time in spoil characteristics, species composition and plant biomass. Coarse fragments ({gt} 2 mm) decreased with age of mine spoil while the proportion of 0.2-0.1 mm particles increased. Total soil N, mineral N, NaHCO{sub 3}-extractable P, and exchangeable K increased with age of mine spoil and these parameters were lower in mine spoils than native forest soil even after 20 years of succession. Exchangeable Na decreased with age of mine spoil and in 20-yr old spoil it was higher than native forest soil. Plant community composition changed with age. Only a few species participated in community formation. Species richness increased with age, while evenness and species diversity declined from 5-yr old to 16-yr old community with an increase in the 20-yr old community. A reverse trend occurred for concentration of dominance. Area-weighted shoot and root biomass of other species increased with the age of the mine spoil while that of Xanthium strumarium patches declined with age. Data collection on spoil features, microbial C, N and P,and shoot and root biomass when subjected to Discriminant Analysis indicated a continued profound effect of age. 10 and 12-yr old mine spoils were closer to each other and 5 and 20-yr old spoils were farthest apart.

Spoil characteristics and vegetation development of an age series of mine spoils in a dry tropical environment

International Nuclear Information System (INIS)

Jha, A.K.; Singh, J.S.

1991-01-01

A series of coal mine spoils (5,10,12,16 and 20-yr old) in a dry tropical environment was sampled to assess the changes with time in spoil characteristics, species composition and plant biomass. Coarse fragments (> 2 mm) decreased with age of mine spoil while the proportion of 0.2-0.1 mm particles increased. Total soil N, mineral N, NaHCO 3 -extractable P, and exchangeable K increased with age of mine spoil and these parameters were lower in mine spoils than native forest soil even after 20 years of succession. Exchangeable Na decreased with age of mine spoil and in 20-yr old spoil it was higher than native forest soil. Plant community composition changed with age. Only a few species participated in community formation. Species richness increased with age, while evenness and species diversity declined from 5-yr old to 16-yr old community with an increase in the 20-yr old community. A reverse trend occurred for concentration of dominance. Area-weighted shoot and root biomass of other species increased with the age of the mine spoil while that of Xanthium strumarium patches declined with age. Data collection on spoil features, microbial C, N and P,and shoot and root biomass when subjected to Discriminant Analysis indicated a continued profound effect of age. 10 and 12-yr old mine spoils were closer to each other and 5 and 20-yr old spoils were farthest apart

Tropical rain forest: a wider perspective

National Research Council Canada - National Science Library

Goldsmith, F. B

1998-01-01

.... Barbier -- Can non-market values save the tropical forests? / D. Pearce -- The role of policy and institutions / James Mayers and Stephen Bass -- Modelling tropical land use change and deforestation...

Virus tropical: Presencia y relevancia del personaje autobiográfico femenino en la novela gráfica colombiana

Directory of Open Access Journals (Sweden)

Felipe Gómez Gutiérrez

2015-04-01

Abstract Here I analyze Virus Tropical (Colombia, 2009, a graphic novel by PowerPaola. Despite having achieved great popularity for a Latin American graphic novel –with national and international publications in both print and electronic formats–, it still has not been properly considered or analyzed in traditional academic media; particularly in Latin America where the study of comics is considered a matter of minor importance, and therefore discussions about Virus Tropical were relegated to alternative, communitarian spaces, such as public libraries or bookstores. Because Virus Tropical poses a challenge to the notion of the male comic book creator, because of its use of visual language to defy stereotypical female characters, and because of the way it engages issues of contemporary comic production, in this article I argue for a sound academic engagement with comics like this one.

What was tropical about tropical neurasthenia? The utility of the diagnosis in the management of British East Africa.

Science.gov (United States)

Crozier, Anna

2009-10-01

During the first quarter of the twentieth century, tropical neurasthenia was a popular diagnosis for a nervous condition experienced by Europeans in the topics. Tropical neurasthenia was not psychosis or madness, but was rather an ennui or loss of "edge" brought about by the strains of tropical life, especially the unfamiliar, hot climate. A catch-all for a wide range of symptoms, many missionaries, colonial staff, and settlers throughout Empire were repatriated because of it, although this article concentrates on Colonial Service employees working in British East Africa. While histories of tropical neurasthenia have usefully (and correctly) explained this diagnosis as an expression of the anxieties of the colonial regime, this article adds a new dimension to the historiography by arguing that tropical neurasthenia can only be properly understood as a hybrid form, dependent not only upon the peculiarities of the colonial situation, but also descended from British and American clinical understandings of neurasthenia. Moreover, once tropical neurasthenia is properly acknowledged as being typical of clinical understandings of the time, other reasons for its comparatively long endurance in the colonial situation emerge. This article shows that tropical neurasthenia remained a popular diagnosis in East Africa not only because (as historians have argued previously) it dovetailed with prevalent ideas of colonial acclimatization, but also because it was a practically useful tool in the management and regulation of colonial personnel.

Remote-Sensing Hydraulic Characterization of Channel Habitat Units in a Tropical Montane River: Bladen River, Belize

Directory of Open Access Journals (Sweden)

Sarah Praskievicz

2017-12-01

Full Text Available The physical characteristics of river systems exert significant control on the habitat for aquatic species, including the distribution of in-stream channel habitat units. Most previous studies on channel habitat units have focused on midlatitude rivers, which differ in several substantive ways from tropical rivers. Field delineation of channel habitat units is especially challenging in tropical rivers, many of which are remote and difficult to access. Here, we developed an approach for delineating channel habitat units based on a combination of field measurements, remote sensing, and hydraulic modeling, and applied it to a 4.1-km segment of the Bladen River in southern Belize. We found that the most prevalent channel habitat unit on the study segment was runs, followed by pools and riffles. Average spacing of channel habitat units was up to twice as high on the study segment than the typical values reported for midlatitude rivers, possibly because of high erosion rates in the tropical environment. The approach developed here can be applied to other rivers to build understanding of the controls on and spatial distribution of channel habitat units on tropical rivers and to support river management and conservation goals.

Archives: Tropical Journal of Pharmaceutical Research

African Journals Online (AJOL)

Items 1 - 50 of 97 ... Archives: Tropical Journal of Pharmaceutical Research. Journal Home > Archives: Tropical Journal of Pharmaceutical Research. Log in or Register to get access to full text downloads.

Tree height and tropical forest biomass estimation

Science.gov (United States)

M.O. Hunter; M. Keller; D. Vitoria; D.C. Morton

2013-01-01

Tropical forests account for approximately half of above-ground carbon stored in global vegetation. However, uncertainties in tropical forest carbon stocks remain high because it is costly and laborious to quantify standing carbon stocks. Carbon stocks of tropical forests are determined using allometric relations between tree stem diameter and height and biomass....

The design and application of a radiological consequence model for tropical and subtropical regions

International Nuclear Information System (INIS)

Domel, R.U.; Harris, F.F.; Crawford, J.

1997-01-01

The post Chernobyl era has seen the development of a plethora of radiological consequence models. At ANSTO, a model is being developed with a user-friendly interface which will assess the radiological consequences, after an incident, in tropical and sub-tropical climates. The model combines specific regional dispersion and deposition data to determine the dose to man via the major pathways of external and internal irradiation. The external irradiation data will need to include lifestyle information such as time spent L indoors/outdoors, the high/low activity times of the different groups of people (especially critical groups) and shielding factors for housing. The internal irradiation data requires food consumption values, effect of food processing and transfer parameters (soil to plant, plant to animal) to be obtained for tropical and sub-tropical regions. The model allows the user to specify the radionuclide of interest, the age of the person receiving l the dose, race, dietary components and lifestyle. The operator may use a number of default categories, but regional information may also be entered and incorporated into the radiological model allowing assessment of dose to critical groups using site specific data. Initially, the model will deal with the South East Asian region but flexibility has been incorporated into the design to allow application in other regions. A geographic information system is used for display of all input and output data allowing quick access to not only the results but also the underlying assumptions. The model also has portability across computer platforms. The model has been developed to provide a tool for directing future research, has application as a planing tool for emergency response operations but its priority lies in understanding the behaviour of radionuclides in the tropical and sub-tropical environments and their effect on humankind

[Profile of tropical diseases in Portugal].

Science.gov (United States)

Ventura, F A

1996-01-01

The increased incidence of Imported Tropical Diseases in Portugal is correlated to a recent higher standard of living, influence of media and a consequent expansion of tourism, and above all to the close relationship existing between Portugal and Africa. The number and pathology (parasitic diarrhoeas, protozoal and helminthic infections) of in-patients with Tropical Diseases at the Unidade de Doenças Infecciosas, Parasitárias e de Medicina Tropical (UDIP-MT) were described, with special emphasis on Malaria (155 in-patients during the period from 1989 to 1993) and on Sleeping Sickness, where Eflornitin (DFMO) was for the first time used in Portugal. Finally, the impact of HIV epidemic on incidence and different clinical presentations of parasitic and other tropical pathology was also evaluated.

[Tropical chronic pancreatitis in a young patient].

Science.gov (United States)

Reyes, J; Ginard, D; Barranco, L; Riera, J; Obrador, A

2001-11-01

Tropical chronic pancreatitis is a form of idiopathic chronic pancreatitis that has not previously been described in Spain. Typically it is related to dietary factors and malnutrition, although genetic factors may also play a significant role in the development of the disease. We report a case of chronic tropical pancreatitis in a 27-year-old woman from the Dominican Republic domiciled in Spain since 1992. The patient was admitted to our hospital for acute pancreatitis that fulfilled the diagnostic criteria (clinical and radiological) for chronic tropical pancreatitis. This case has led us to review this uncommon entity. Because of the increasing number of immigrants from tropical countries, chronic tropical pancreatitis will probably need to be taken into account in the differential diagnosis of chronic pancreatitis in our patients.

Multiscaling properties of tropical rainfall: Analysis of rain gauge datasets in Lesser Antilles island environment

Science.gov (United States)

Bernard, Didier C.; Pasquier, Raphaël; Cécé, Raphaël; Dorville, Jean-François

2014-05-01

Changes in rainfall seem to be the main impact of climate change in the Caribbean area. The last conclusions of IPCC (2013), indicate that the end of this century will be marked by a rise of extreme rainfalls in tropical areas, linked with increase of the mean surface temperature. Moreover, most of the Lesser Antilles islands are characterized by a complex topography which tends to enhance the rainfall from synoptic disturbances by orographic effects. In the past five years, out of hurricanes passage, several extreme rainy events (approx. 16 mm in 6 minutes), including fatal cases, occurred in the Lesser Antilles Arc: in Guadeloupe (January 2011, May 2012 and 2013), in Martinique (May 2009, April 2011 and 2013), in Saint-Lucia (December 2013). These phenomena inducing floods, loss of life and material damages (agriculture sector and public infrastructures), inhibit the development of the islands. At this time, numerical weather prediction models as WRF, which are based on the equations of the atmospheric physics, do not show great results in the focused area (Bernard et al., 2013). Statistical methods may be used to examine explicitly local rainy updrafts, thermally and orographically induced at micro-scale. The main goal of the present insular tropical study is to characterize the multifractal symmetries occurring in the 6-min rainfall time series, registered since 2006 by the French Met. Office network weather stations. The universal multifractal model (Schertzer and Lovejoy, 1991) is used to define the statistical properties of measured rainfalls at meso-scale and micro-scale. This model is parametrized by a fundamental exponents set (H,a,C1,q) which are determined and compared with values found in the literature. The first three parameters characterize the mean pattern and the last parameter q, the extreme pattern. The occurrence ranges of multifractal regime are examined. The suggested links between the internal variability of the tropical rainy events and the

Using high resolution satellite multi-temporal interferometry for landslide hazard detection in tropical environments: the case of Haiti

Science.gov (United States)

Wasowski, Janusz; Nutricato, Raffaele; Nitti, Davide Oscar; Bovenga, Fabio; Chiaradia, Maria Teresa; Piard, Boby Emmanuel; Mondesir, Philemon

2015-04-01

Synthetic aperture radar (SAR) multi-temporal interferometry (MTI) is one of the most promising satellite-based remote sensing techniques for fostering new opportunities in landslide hazard detection and assessment. MTI is attractive because it can provide very precise quantitative information on slow slope displacements of the ground surface over huge areas with limited vegetation cover. Although MTI is a mature technique, we are only beginning to realize the benefits of the high-resolution imagery that is currently acquired by the new generation radar satellites (e.g., COSMO-SkyMed, TerraSAR-X). In this work we demonstrate the potential of high resolution X-band MTI for wide-area detection of slope instability hazards even in tropical environments that are typically very harsh (eg. coherence loss) for differential interferometry applications. This is done by presenting an example from the island of Haiti, a tropical region characterized by dense and rapidly growing vegetation, as well as by significant climatic variability (two rainy seasons) with intense precipitation events. Despite the unfavorable setting, MTI processing of nearly 100 COSMO-SkyMed (CSK) mages (2011-2013) resulted in the identification of numerous radar targets even in some rural (inhabited) areas thanks to the high resolution (3 m) of CSK radar imagery, the adoption of a patch wise processing SPINUA approach and the presence of many man-made structures dispersed in heavily vegetated terrain. In particular, the density of the targets resulted suitable for the detection of some deep-seated and shallower landslides, as well as localized, very slow slope deformations. The interpretation and widespread exploitation of high resolution MTI data was facilitated by Google EarthTM tools with the associated high resolution optical imagery. Furthermore, our reconnaissance in situ checks confirmed that MTI results provided useful information on landslides and marginally stable slopes that can represent a

Natural and near natural tropical forest values

Science.gov (United States)

Daniel H. Henning

2011-01-01

This paper identifies and describes some of the values associated with tropical rain forests in their natural and near-natural conditions. Tropical rain forests are moist forests in the humid tropics where temperature and rainfall are high and the dry season is short. These closed (non-logged) and broad-leaved forests are a global resource. Located almost entirely in...

Height-diameter allometry of tropical forest trees

Science.gov (United States)

T.R. Feldpausch; L. Banin; O.L. Phillips; T.R. Baker; S.L. Lewis; C.A. Quesada; K. Affum-Baffoe; E.J.M.M. Arets; N.J. Berry; M. Bird; E.S. Brondizio; P de Camargo; J. Chave; G. Djagbletey; T.F. Domingues; M. Drescher; P.M. Fearnside; M.B. Franca; N.M. Fyllas; G. Lopez-Gonzalez; A. Hladik; N. Higuchi; M.O. Hunter; Y. Iida; K.A. Salim; A.R. Kassim; M. Keller; J. Kemp; D.A. King; J.C. Lovett; B.S. Marimon; B.H. Marimon-Junior; E. Lenza; A.R. Marshall; D.J. Metcalfe; E.T.A. Mitchard; E.F. Moran; B.W. Nelson; R. Nilus; E.M. Nogueira; M. Palace; S. Patiño; K.S.-H. Peh; M.T. Raventos; J.M. Reitsma; G. Saiz; F. Schrodt; B. Sonke; H.E. Taedoumg; S. Tan; L. White; H. Woll; J. Lloyd

2011-01-01

Tropical tree height-diameter (H:D) relationships may vary by forest type and region making large-scale estimates of above-ground biomass subject to bias if they ignore these differences in stem allometry. We have therefore developed a new global tropical forest database consisting of 39 955 concurrent H and D measurements encompassing 283 sites in 22 tropical...

Fine particulate matter in the tropical environment: monsoonal effects, source apportionment, and health risk assessment

OpenAIRE

M. F. Khan; M. F. Khan; M. T. Latif; M. T. Latif; W. H. Saw; N. Amil; N. Amil; M. S. M. Nadzir; M. S. M. Nadzir; M. Sahani; N. M. Tahir; N. M. Tahir; J. X. Chung

2016-01-01

The health implications of PM2.5 in the tropical region of Southeast Asia (SEA) are significant as PM2.5 can pose serious health concerns. PM2.5 concentration and sources here are strongly influenced by changes in the monsoon regime from the south-west quadrant to the north-east quadrant in the region. In this work, PM2.5 samples were collected at a semi-urban area using a high-volume air sampler at different seasons on 24 h basis. Analysis of trace elements and water-sol...

Thermal adaptation and diversity in tropical ecosystems: evidence from cicadas (Hemiptera, Cicadidae.

Directory of Open Access Journals (Sweden)

Allen F Sanborn

Full Text Available The latitudinal gradient in species diversity is a central problem in ecology. Expeditions covering approximately 16°54' of longitude and 21°4' of latitude and eight Argentine phytogeographic regions provided thermal adaptation data for 64 species of cicadas. We test whether species diversity relates to the diversity of thermal environments within a habitat. There are general patterns of the thermal response values decreasing in cooler floristic provinces and decreasing maximum potential temperature within a habitat except in tropical forest ecosystems. Vertical stratification of the plant communities leads to stratification in species using specific layers of the habitat. There is a decrease in thermal tolerances in species from the understory communities in comparison to middle level or canopy fauna. The understory Herrera umbraphila Sanborn & Heath is the first diurnally active cicada identified as a thermoconforming species. The body temperature for activity in H. umbraphila is less than and significantly different from active body temperatures of all other studied species regardless of habitat affiliation. These data suggest that variability in thermal niches within the heterogeneous plant community of the tropical forest environments permits species diversification as species adapt their physiology to function more efficiently at temperatures different from their potential competitors.

Thermal adaptation and diversity in tropical ecosystems: evidence from cicadas (Hemiptera, Cicadidae).

Science.gov (United States)

Sanborn, Allen F; Heath, James E; Phillips, Polly K; Heath, Maxine S; Noriega, Fernando G

2011-01-01

The latitudinal gradient in species diversity is a central problem in ecology. Expeditions covering approximately 16°54' of longitude and 21°4' of latitude and eight Argentine phytogeographic regions provided thermal adaptation data for 64 species of cicadas. We test whether species diversity relates to the diversity of thermal environments within a habitat. There are general patterns of the thermal response values decreasing in cooler floristic provinces and decreasing maximum potential temperature within a habitat except in tropical forest ecosystems. Vertical stratification of the plant communities leads to stratification in species using specific layers of the habitat. There is a decrease in thermal tolerances in species from the understory communities in comparison to middle level or canopy fauna. The understory Herrera umbraphila Sanborn & Heath is the first diurnally active cicada identified as a thermoconforming species. The body temperature for activity in H. umbraphila is less than and significantly different from active body temperatures of all other studied species regardless of habitat affiliation. These data suggest that variability in thermal niches within the heterogeneous plant community of the tropical forest environments permits species diversification as species adapt their physiology to function more efficiently at temperatures different from their potential competitors.

Tropical Rainforest Education. ERIC Digest.

Science.gov (United States)

Rillero, Peter

This digest provides four guideposts for tropical rainforest education: (1) structure; (2) location and climate; (3) importance; and (4) conservation of resources. Research is cited and background information provided about the layers of life and the adaptations of life within the tropical rain forest. Aspects of life within and near rain forests…

Global Warming Attenuates the Tropical Atlantic-Pacific Teleconnection

Science.gov (United States)

Jia, Fan; Wu, Lixin; Gan, Bolan; Cai, Wenju

2016-01-01

Changes in global sea surface temperature (SST) since the end of last century display a pattern of widespread warming intercepted by cooling in the eastern equatorial Pacific and western coasts of the American continent. Studies have suggested that the cooling in the eastern equatorial Pacific may be partly induced by warming in the North Atlantic. However, it remains unknown how stable this inter-tropical teleconnection will be under global warming. Here we show that the inter-tropical teleconnection from the tropical Atlantic to Pacific weakens substantially as the CO2 concentration increases. This reduced impact is related to the El Niño-like warming of the tropical Pacific mean state, which leads to limited seasonal migration of the Pacific inter-tropical convergence zone (ITCZ) and weakened ocean heat transport. A fast decay of the tropical Atlantic SST anomalies in a warmer climate also contributes to the weakened teleconnection. Our study suggests that as greenhouse warming continues, the trend in the tropical Pacific as well as the development of ENSO will be less frequently interrupted by the Atlantic because of this attenuation. The weakened teleconnection is also supported by CMIP5 models, although only a few of these models can capture this inter-tropical teleconnection. PMID:26838053

Global Warming Attenuates the Tropical Atlantic-Pacific Teleconnection.

Science.gov (United States)

Jia, Fan; Wu, Lixin; Gan, Bolan; Cai, Wenju

2016-02-03

Changes in global sea surface temperature (SST) since the end of last century display a pattern of widespread warming intercepted by cooling in the eastern equatorial Pacific and western coasts of the American continent. Studies have suggested that the cooling in the eastern equatorial Pacific may be partly induced by warming in the North Atlantic. However, it remains unknown how stable this inter-tropical teleconnection will be under global warming. Here we show that the inter-tropical teleconnection from the tropical Atlantic to Pacific weakens substantially as the CO2 concentration increases. This reduced impact is related to the El Niño-like warming of the tropical Pacific mean state, which leads to limited seasonal migration of the Pacific inter-tropical convergence zone (ITCZ) and weakened ocean heat transport. A fast decay of the tropical Atlantic SST anomalies in a warmer climate also contributes to the weakened teleconnection. Our study suggests that as greenhouse warming continues, the trend in the tropical Pacific as well as the development of ENSO will be less frequently interrupted by the Atlantic because of this attenuation. The weakened teleconnection is also supported by CMIP5 models, although only a few of these models can capture this inter-tropical teleconnection.

Mid-Cretaceous amber fossils illuminate the past diversity of tropical lizards

Science.gov (United States)

Daza, Juan D.; Stanley, Edward L.; Wagner, Philipp; Bauer, Aaron M.; Grimaldi, David A.

2016-01-01

Modern tropical forests harbor an enormous diversity of squamates, but fossilization in such environments is uncommon and little is known about tropical lizard assemblages of the Mesozoic. We report the oldest lizard assemblage preserved in amber, providing insight into the poorly preserved but potentially diverse mid-Cretaceous paleotropics. Twelve specimens from the Albian-Cenomanian boundary of Myanmar (99 Ma) preserve fine details of soft tissue and osteology, and high-resolution x-ray computed tomography permits detailed comparisons to extant and extinct lizards. The extraordinary preservation allows several specimens to be confidently assigned to groups including stem Gekkota and stem Chamaleonidae. Other taxa are assignable to crown clades on the basis of similar traits. The detailed preservation of osteological and soft tissue characters in these specimens may facilitate their precise phylogenetic placement, making them useful calibration points for molecular divergence time estimates and potential keys for resolving conflicts in higher-order squamate relationships. PMID:26973870

Japan and the global environment

International Nuclear Information System (INIS)

Miller, A.S.; Moore, C.

1993-01-01

In many areas, the word most often used to describe Japanese policy is open-quotes enigma.close quotes In some ways, Japan's record on environmental policy also has elements of mystery and contradiction. On the one hand, Japan's history and culture often are associated with a reverence for nature. Indeed, Japan does lead the world in certain environmental areas, such as reduction of conventional air pollutants and compensation of air pollution victims. On the other hand, Japan has been widely criticized for its poor record in preserving its domestic environment, contribution to tropical deforestation, and unwillingness to protect endangered species. Today, the international community clamors for Japan to take its share of responsibility, as an economic superpower, for the global environment. To secure its place in world affairs, Japan slowly has begun to respond to this pressure on issues ranging from ivory importation to reduction of CFC emissions. There is some hope that the government's particular willingness to address global warming may be a sign of significant changes to come in Japanese environmental policy. However, international pressure remains on the many environmental issues Japan has yet to resolve, including tropical deforestation and financing of Third World development projects that harm the environment. Japan's environmental policy is most effective when government and industry cooperate to find technical solutions to environmental problems. Although in recent years Japan's energy consumption has risen sharply, the Japanese have developed numerous technologies to reduce pollution and increase economic growth by improving energy efficiency. It is in these technologies that Japan has made the greatest strides and has the most to offer the global environment

Environment factors to achieve strategic objectives in companies

Directory of Open Access Journals (Sweden)

Guga, L.

2010-12-01

Full Text Available Strategic management begins with an evaluation of the organization’s mission, goals, and strategy. This is followed by situation analysis (sometimes called SWOT analysis which examines opportunities and threats in the external environment as well as strengths and weaknesses within the organization. Situation analysis leads to the formulation of explicit strategic plans, which then must be implemented.This planning usually takes place in for-profit business organizations and pertains to competitive actions on the market. Although some companies hire strategic planning experts, the responsibility for strategic planning rests with line managers. Seniors executives of companies want middle and lower-level line managers to think strategically. Strategic thinking means to take the long-term view and to see the big picture, including the organization and the competitive environment and consider how they fit together. Understanding the strategy concept, the levels of strategy, and strategy formulations versus implementation is an important start towards strategic thinking.

Physical and meteorological data from the Tropical Atmosphere Ocean (TAO) array in the tropical Pacific Ocean

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Tropical Atmosphere Ocean (TAO) Array of 55 moored buoys spans the tropical Pacific from longitudes 165°E to 95°W between latitudes of approximately 8°S and...

Isotopic composition of nitrate in the central Arabian Sea and eastern tropical North Pacific: A tracer for mixing and nitrogen cycles

Digital Repository Service at National Institute of Oceanography (India)

Brandes, J.A.; Devol, A.H.; Yoshinari, T.; Jayakumar, D.A.; Naqvi, S.W.A.

Trench. Ph.D. Thesis, Univ. of Cali- fornia, Los Angeles. -. AND I. R. KAPLAN. 1975. Isotopic fractionation of dissolved nitrate during denitrification in the eastern tropical North Pa- cific. Mar. Chem. 3: 271-299. CODISPOTI, L. A., AND J. P....-K. 1979. Geochemistry of inorganic nitrogen compounds in two marine environments: The Santa Barbara basin and the ocean off Peru. Ph.D. Thesis, Univ. of California, Los Angeles. -, AND I. R. KAPLAN. 1989. The eastern tropical Pacific as a source of 15N...

Multiple successional pathways in human-modified tropical landscapes

NARCIS (Netherlands)

Arroyo-Rodríguez, Víctor; Melo, Felipe P.L.; Martínez-Ramos, Miguel; Bongers, Frans; Chazdon, Robin L.; Meave, Jorge A.; Norden, Natalia; Santos, Bráulio A.; Leal, Inara R.; Tabarelli, Marcelo

2017-01-01

Old-growth tropical forests are being extensively deforested and fragmented worldwide. Yet forest recovery through succession has led to an expansion of secondary forests in human-modified tropical landscapes (HMTLs). Secondary forests thus emerge as a potential repository for tropical

Role of the Convective Scheme in Modeling Initiation and Intensification of Tropical Depressions over the North Atlantic

Science.gov (United States)

Duvel, Jean Philippe; Camargo, Suzana; Sobel, Adam

2016-04-01

Modifications of the large-scale environment related to intraseasonal (MJO) and interannual (ENSO) time-scale variability or to global climate warming may have important impacts on the tropical cyclonic activity. This sensitivity of tropical cyclones (TC) on environmental changes can now be studied using General Circulation Models (GCM). Before doing sensitivity studies with a GCM, it is interesting to assess the representation of the TC activity for different configurations (resolution, parameterization) of the GCM in present climate conditions and to trace possible causes of bias in TC number, location or strength. A possible approach to do this assessment is to separate initiation and intensification processes. By using either GCM output, or meteorological analysis combined to TC observation databases, it is possible to study the condition of formation of tropical depressions vortices (TDV) at an early stage and their possible intensification into a TC (say the Tropical Storm stage). We use the LMDZ GCM to study the sensitivity of TDV characteristics to different entrainment and closure formulations of the convective scheme. The study focuses on the Tropical North Atlantic using the "zoom" capability of the LMDZ GCM. The horizontal resolution of the model is set to 0.75° over a large region of the North Atlantic and West Africa. The GCM is free to run in this region and is tied to ERA-Interim reanalysis outside that region, with intermediate relaxation times in-between. We use the Tiedtke convective scheme with entrainment and closure based on the moisture convergence, or with an entrainment based on the relative humidity of the environment, and additionally a closure based on CAPE. Each configuration is run for 10 years between 2000 and 2009 with prescribed SST. In summary, the convective entrainment based on the relative humidity in the environment deepens the TDV in LMDZ, resulting in more TDV and TC. The convective closure mitigates this tendency and

Economic, Socio-Political and Environmental Risks of Road Development in the Tropics.

Science.gov (United States)

Alamgir, Mohammed; Campbell, Mason J; Sloan, Sean; Goosem, Miriam; Clements, Gopalasamy Reuben; Mahmoud, Mahmoud I; Laurance, William F

2017-10-23

It is projected that 25 million km of new paved roads will be developed globally by 2050 - enough to encircle the planet more than 600 times. Roughly 90% of new roads will be built in developing nations, frequently in tropical and subtropical regions with high biodiversity and environmental values. Many developing nations are borrowing from international lenders or negotiating access to their natural resources in order to expand their transportation infrastructure. Given the unprecedented pace and extent of these initiatives, it is vital to thoroughly assess the potential consequences of large-scale road and highway projects. In appropriate contexts and locales, new roads can promote sizeable economic and social benefits. If poorly planned or implemented, however, new roads can provoke serious cost overruns, corruption and environmental impacts, while generating sparse economic benefits and intense social and political conflict. Using examples from developing nations, we identify risks that can hinder road projects in wet and dry tropical environments. Such risks, we assert, are often inadequately considered by project proponents, evaluators and the general public, creating a systematic tendency to overestimate project benefits while understating project risks. A more precautionary approach is needed to reduce risks while maximizing benefits of new road projects in the tropics. Copyright © 2017 Elsevier Ltd. All rights reserved.

The influence of production conditions, starting material and deposition environment on charcoal alteration in a tropical biome.

Science.gov (United States)

Ascough, Philippa; Bird, Michael; Meredith, Will; Large, David; Snape, Colin; Manion, Corinne

2014-05-01

Natural and anthropogenic burning events are a key link in the global carbon cycle, substantially influencing atmospheric CO2 levels, and consuming c.8700 teragrams yr-1 of dry biomass [1,2,3]. An important result of this process is charcoal, when lignocellulosic structures in biomass (e.g. wood) are converted to aromatic domains with high chemical stability. Charcoal is therefore not readily re-oxidized to CO2, with estimates of 5-7 ky for the half-life of charcoal carbon in soils [3,4]. Charcoal's high carbon content coupled with high environmental resistance has led to the concept of biochar as a valuable means of global carbon sequestration, capable of carbon offsets comparable to annual anthropogenic fuel emissions [5,6,7]. Charcoal is not, however, an environmentally inert substance, and at least some components of charcoal are susceptible to alteration in depositional environments. Despite the importance of charcoal in global carbon cycling, the mechanisms by which charcoal is altered in the environment remain, as yet, poorly understood. This fact limits our ability to properly incorporate both natural environmental charcoal and biochar into global carbon budgets. This study aimed to improve understanding of charcoal alteration in the environment by examining the influence of production conditions, starting material and deposition environment on the physical and chemical characteristics of charcoal at a field site in the Daintree rainforest. These factors have been identified as critical in determining the dynamics of charcoal in depositional environments [8,9] and climatic conditions at the field site (in Tropical Queensland, Australia) are likely to result in extensive alteration of charcoal. Charcoal from wood (Nothofagus spp.), algae (Enteromorpha spp.), and sugarcane (Saccharum spp.) biomass was produced at temperatures over 300-500°C and exposed to conditions of varying pH and vegetation cover. The effect of these variables on charcoal chemistry

Restoring degraded tropical forests for carbon and biodiversity

International Nuclear Information System (INIS)

Budiharta, Sugeng; Meijaard, Erik; Wilson, Kerrie A; Erskine, Peter D; Rondinini, Carlo; Pacifici, Michela

2014-01-01

The extensive deforestation and degradation of tropical forests is a significant contributor to the loss of biodiversity and to global warming. Restoration could potentially mitigate the impacts of deforestation, yet knowledge on how to efficiently allocate funding for restoration is still in its infancy. We systematically prioritize investments in restoration in the tropical landscape of East Kalimantan, Indonesia, and through this application demonstrate the capacity to account for a diverse suite of restoration techniques and forests of varying condition. To achieve this we develop a map of forest degradation for the region, characterized on the basis of aboveground biomass and differentiated by broad forest types. We estimate the costs of restoration as well as the benefits in terms of carbon sequestration and improving the suitability of habitat for threatened mammals through time. When the objective is solely to enhance carbon stocks, then restoration of highly degraded lowland forest is the most cost-effective activity. However, if the objective is to improve the habitat of threatened species, multiple forest types should be restored and this reduces the accumulated carbon by up to 24%. Our analysis framework provides a transparent method for prioritizing where and how restoration should occur in heterogeneous landscapes in order to maximize the benefits for carbon and biodiversity. (letter)

Restoring degraded tropical forests for carbon and biodiversity

Science.gov (United States)

Budiharta, Sugeng; Meijaard, Erik; Erskine, Peter D.; Rondinini, Carlo; Pacifici, Michela; Wilson, Kerrie A.

2014-11-01

The extensive deforestation and degradation of tropical forests is a significant contributor to the loss of biodiversity and to global warming. Restoration could potentially mitigate the impacts of deforestation, yet knowledge on how to efficiently allocate funding for restoration is still in its infancy. We systematically prioritize investments in restoration in the tropical landscape of East Kalimantan, Indonesia, and through this application demonstrate the capacity to account for a diverse suite of restoration techniques and forests of varying condition. To achieve this we develop a map of forest degradation for the region, characterized on the basis of aboveground biomass and differentiated by broad forest types. We estimate the costs of restoration as well as the benefits in terms of carbon sequestration and improving the suitability of habitat for threatened mammals through time. When the objective is solely to enhance carbon stocks, then restoration of highly degraded lowland forest is the most cost-effective activity. However, if the objective is to improve the habitat of threatened species, multiple forest types should be restored and this reduces the accumulated carbon by up to 24%. Our analysis framework provides a transparent method for prioritizing where and how restoration should occur in heterogeneous landscapes in order to maximize the benefits for carbon and biodiversity.

Which statistics should tropical biologists learn?

Science.gov (United States)

Loaiza Velásquez, Natalia; González Lutz, María Isabel; Monge-Nájera, Julián

2011-09-01

Tropical biologists study the richest and most endangered biodiversity in the planet, and in these times of climate change and mega-extinctions, the need for efficient, good quality research is more pressing than in the past. However, the statistical component in research published by tropical authors sometimes suffers from poor quality in data collection; mediocre or bad experimental design and a rigid and outdated view of data analysis. To suggest improvements in their statistical education, we listed all the statistical tests and other quantitative analyses used in two leading tropical journals, the Revista de Biología Tropical and Biotropica, during a year. The 12 most frequent tests in the articles were: Analysis of Variance (ANOVA), Chi-Square Test, Student's T Test, Linear Regression, Pearson's Correlation Coefficient, Mann-Whitney U Test, Kruskal-Wallis Test, Shannon's Diversity Index, Tukey's Test, Cluster Analysis, Spearman's Rank Correlation Test and Principal Component Analysis. We conclude that statistical education for tropical biologists must abandon the old syllabus based on the mathematical side of statistics and concentrate on the correct selection of these and other procedures and tests, on their biological interpretation and on the use of reliable and friendly freeware. We think that their time will be better spent understanding and protecting tropical ecosystems than trying to learn the mathematical foundations of statistics: in most cases, a well designed one-semester course should be enough for their basic requirements.

Estimativa do balanço térmico por radiação em vacas Holandesas expostas ao sol e à sombra em ambiente tropical Estimate of radiation heat balance of Holstein cows in the sun and under the shade in a tropical environment

Directory of Open Access Journals (Sweden)

Roberto Gomes da Silva

1999-01-01

Full Text Available É apresentado um método para a estimativa do balanço térmico por radiação em vacas da raça Holandesa expostas ao sol e sob a sombra em uma pastagem, com o objetivo de estabelecer um padrão morfológico mais adequado para esses animais em região tropical. O método envolve a determinação das características do pelame (área de superfície de malhas negras, espessura da capa, comprimento e diâmetro dos pêlos, número de pêlos por unidade de área, temperatura da superfície da capa e da epiderme e variáveis ambientais (irradiância solar, temperatura do ar e de globo, vento. Foi determinada a quantidade de radiação de ondas curtas efetivamente transmitida através do pelame e que atinge as camadas profundas da epiderme. Demonstrou-se, por intermédio de um exemplo prático, que as áreas de pelame negro apresentaram balanço radiante mais elevado que as áreas brancas, mas estas últimas possuiam maior transmissividade para a radiação de ondas curtas. Animais predominantemente negros foram melhor protegidos contra a radiação de ondas curtas que os predominantemente brancos, especialmente quando a capa de pelame é pouco espessa (até 4 a 7 mm, mais adequada para ambientes tropicais.A method is presented to estimate the radiation heat balance of Holstein cows exposed to sun and under shade of a pasture, to contribute with a morphological characteristics better adequate for these animals in a tropical environment. The methods involved the haircoat characteristics (surface area of black spots, coat thickness, hair length, hair diameter, number of hairs per unit of area, skin and coat surface temperatures and environmental variables (solar irradiance, wind speed, air and globe temperatures. The amount of shortwave energy which effectively is transmitted through the haircoat and that reach deply the epiderms layers was obtained. It was demonstrated by a practical example that the black areas of the coat presented higher radiation

The evolution of dwarf shrubs in alpine environments: a case study of Alchemilla in Africa.

Science.gov (United States)

Gehrke, Berit; Kandziora, Martha; Pirie, Michael D

2016-01-01

Alpine and arctic environments worldwide, including high mountains, are dominated by short-stature woody plants (dwarf shrubs). This conspicuous life form asserts considerable influence on local environmental conditions above the treeline, creating its own microhabitat. This study reconstructs the evolution of dwarf shrubs in Alchemilla in the African tropical alpine environment, where they represent one of the largest clades and are among the most common and abundant plants. Different phylogenetic inference methods were used with plastid and nuclear DNA sequence markers, molecular dating (BEAST and RelTime), analyses of diversification rate shifts (MEDUSA and BAMM) and ancestral character and area reconstructions (Mesquite). It is inferred that African Alchemilla species originated following long-distance dispersal to tropical East Africa, but that the evolution of dwarf shrubs occurred in Ethiopia and in tropical East Africa independently. Establishing a timeframe is challenging given inconsistencies in age estimates, but it seems likely that they originated in the Pleistocene, or at the earliest in the late Miocene. The adaptation to alpine-like environments in the form of dwarf shrubs has apparently not led to enhanced diversification rates. Ancestral reconstructions indicate reversals in Alchemilla from plants with a woody base to entirely herbaceous forms, a transition that is rarely reported in angiosperms. Alchemilla is a clear example of in situ tropical alpine speciation. The dwarf shrub life form typical of African Alchemilla has evolved twice independently, further indicating its selective advantage in these harsh environments. However, it has not influenced diversification, which, although recent, was not rapid. © The Author 2015. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Growth response and acclimation of CO2 exchange characteristics to elevated temperatures in tropical tree seedlings.

Science.gov (United States)

Cheesman, Alexander W; Winter, Klaus

2013-09-01

Predictions of how tropical forests will respond to future climate change are constrained by the paucity of data on the performance of tropical species under elevated growth temperatures. In particular, little is known about the potential of tropical species to acclimate physiologically to future increases in temperature. Seedlings of 10 neo-tropical tree species from different functional groups were cultivated in controlled-environment chambers under four day/night temperature regimes between 30/22 °C and 39/31 °C. Under well-watered conditions, all species showed optimal growth at temperatures above those currently found in their native range. While non-pioneer species experienced catastrophic failure or a substantially reduced growth rate under the highest temperature regime employed (i.e. daily average of 35 °C), growth in three lowland pioneers showed only a marginal reduction. In a subsequent experiment, three species (Ficus insipida, Ormosia macrocalyx, and Ochroma pyramidale) were cultivated at two temperatures determined as sub- and superoptimal for growth, but which resulted in similar biomass accumulation despite a 6°C difference in growth temperature. Through reciprocal transfer and temperature adjustment, the role of thermal acclimation in photosynthesis and respiration was investigated. Acclimation potential varied among species, with two distinct patterns of respiration acclimation identified. The study highlights the role of both inherent temperature tolerance and thermal acclimation in determining the ability of tropical tree species to cope with enhanced temperatures.

Black carbon concentrations and sources in the marine boundary layer of the tropical Atlantic Ocean using four methodologies

Science.gov (United States)

Combustion-derived aerosols in the marine boundary layer have been poorly studied, especially in remote environments such as the open Atlantic Ocean. The tropical Atlantic has the potential to contain a high concentration of aerosols, such as black carbon, due to the African emis...

'Combating' tropical diseases in the German colonial press.

Science.gov (United States)

Correa, Sílvio Marcus de Souza

2013-03-01

This article shows how much certain German language newspapers were a vehicule for reporting to the lay public on 'combating' tropical diseases. Through the press, immigrants and their descendents in Brazil were informed not only about the diseases which afflicted German colonists in Africa, but also about measures concerning sanitation, prophylaxis and experiments with tropical medicine, etc. Based on hemerographic sources, it shows how successful the overseas German communities were in sharing their experiences regarding health in tropical and/or sub-tropical regions.

Tropical Fruit Irradiation-From Research to Commercial Application

International Nuclear Information System (INIS)

Moy, James H.

2005-09-01

Food irradiation is an emerging technology for the 21st century. Extensive research and development worldwide in the past 40 years have proved the versatility and efficacy. With low, medium to high dose, and using either a gamma, electrons, or x-ray source, radiation can: 1) disinfest plant products and spices; 2) extend shelf life of tubers, bulbs, and selected tropical fruits; 3) decontaminate meats and seafood; 4) sterilize spices and special meals; and 5) improve product utilization. Criteria for testing its efficacy include effectiveness, efficiency, and the ability to retain product quality. The use of irradiation as a quarantine treatment of tropical fruits is potentially attractive to countries growing these fruits. A two-prong research plan should aim at proving radiation's effectiveness in preventing emergence of all insect pests that might be on a fruit, and determining that all quality attributes of a host fruit are retained after irradiation, subsequent storage and shipment. ommercial application involves conducting an economical feasibility study; market research and testing; selection of radiation source and irradiator type; training of personnel for plant operations, radiation safety and dosimetry monitoring; designing of packages and choosing the most cost-effective means of transporting treated fruits to market destinations. When all of hese are achieved, it should lead to a continuous and profitable operation. Researchers at the University of Hawaii using a gamma irradiator from the mid-1960s to early 2000s had amassed a volume of data to prove the efficacy of radiation disinfestations. And installation of a commercial x-ray irradiator in 2000 on the Island of Hawaii has enabled fruit farmers and packers to use this technology for exporting tropical fruits to distant markets

Isolation and characterization of oxalotrophic bacteria from tropical soils.

Science.gov (United States)

Bravo, Daniel; Braissant, Olivier; Cailleau, Guillaume; Verrecchia, Eric; Junier, Pilar

2015-01-01

The oxalate-carbonate pathway (OCP) is a biogeochemical set of reactions that involves the conversion of atmospheric CO2 fixed by plants into biomass and, after the biological recycling of calcium oxalate by fungi and bacteria, into calcium carbonate in terrestrial environments. Oxalotrophic bacteria are a key element of this process because of their ability to oxidize calcium oxalate. However, the diversity and alternative carbon sources of oxalotrophs participating to this pathway are unknown. Therefore, the aim of this study was to characterize oxalotrophic bacteria in tropical OCP systems from Bolivia, India, and Cameroon. Ninety-five oxalotrophic strains were isolated and identified by sequencing of the 16S rRNA gene. Four genera corresponded to newly reported oxalotrophs (Afipia, Polaromonas, Humihabitans, and Psychrobacillus). Ten strains were selected to perform a more detailed characterization. Kinetic curves and microcalorimetry analyses showed that Variovorax soli C18 has the highest oxalate consumption rate with 0.240 µM h(-1). Moreover, Streptomyces achromogenes A9 displays the highest metabolic plasticity. This study highlights the phylogenetic and physiological diversity of oxalotrophic bacteria in tropical soils under the influence of the oxalate-carbonate pathway.

International Journal of Malaria and Tropical Diseases (IJMTD)

African Journals Online (AJOL)

The International Journal of Malaria and Tropical Diseases (IJMTD) (formally known was the Journal of Malaria in Africa and the Tropics (JMAT) is a publication of the malariologists and researchers in tropical diseases. Its aim is to educate, improved the practice of malaria treatment, stimulate research, encourage academic ...

Homological mirror symmetry and tropical geometry

CERN Document Server

Catanese, Fabrizio; Kontsevich, Maxim; Pantev, Tony; Soibelman, Yan; Zharkov, Ilia

2014-01-01

The relationship between Tropical Geometry and Mirror Symmetry goes back to the work of Kontsevich and Y. Soibelman (2000), who applied methods of non-archimedean geometry (in particular, tropical curves) to Homological Mirror Symmetry. In combination with the subsequent work of Mikhalkin on the “tropical” approach to Gromov-Witten theory, and the work of Gross and Siebert, Tropical Geometry has now become a powerful tool. Homological Mirror Symmetry is the area of mathematics concentrated around several categorical equivalences connecting symplectic and holomorphic (or algebraic) geometry. The central ideas first appeared in the work of Maxim Kontsevich (1993). Roughly speaking, the subject can be approached in two ways: either one uses Lagrangian torus fibrations of Calabi-Yau manifolds (the so-called Strominger-Yau-Zaslow picture, further developed by Kontsevich and Soibelman) or one uses Lefschetz fibrations of symplectic manifolds (suggested by Kontsevich and further developed by Seidel). Tropical Ge...

Healthy Eating and Academic Achievement

Centers for Disease Control (CDC) Podcasts

2014-12-09

This podcast highlights the evidence that supports the link between healthy eating and improved academic achievement. It also identifies a few actions to support a healthy school nutrition environment to improve academic achievement.  Created: 12/9/2014 by National Center for Chronic Disease Prevention and Health Promotion (NCCDPHP).   Date Released: 12/9/2014.

Seagrasses in tropical Australia, productive and abundant for decades decimated overnight.

Science.gov (United States)

Pollard, Peter C; Greenway, Margaret

2013-03-01

Seagrass ecosystems provide unique coastal habitats critical to the life cycle of many species. Seagrasses are a major store of organic carbon. While seagrasses are globally threatened and in decline, in Cairns Harbour, Queensland, on the tropical east coast of Australia, they have flourished. We assessed seagrass distribution in Cairns Harbour between 1953 and 2012 from historical aerial photographs, Google map satellite images, existing reports and our own surveys of their distribution. Seasonal seagrass physiology was assessed through gross primary production, respiration and photosynthetic characteristics of three seagrass species, Cymodocea serrulata, Thalassia hemprichii and Zostera muelleri. At the higher water temperatures of summer, respiration rates increased in all three species, as did their maximum rates of photosynthesis. All three seagrasses achieved maximum rates of photosynthesis at low tide and when they were exposed. For nearly six decades there was little change in seagrass distribution in Cairns Harbour. This was most likely because the seagrasses were able to achieve sufficient light for growth during intertidal and low tide periods. With historical data of seagrass distribution and measures of species production and respiration, could seagrass survival in a changing climate be predicted? Based on physiology, our results predicted the continued maintenance of the Cairns Harbour seagrasses, although one species was more susceptible to thermal disturbance. However, in 2011 an unforeseen episodic disturbance - Tropical Cyclone Yasi - and associated floods lead to the complete and catastrophic loss of all the seagrasses in Cairns Harbour.

Cultural development and environment: a necessity to achieve sustainable development

International Nuclear Information System (INIS)

Azhari, A.

2003-01-01

This paper stresses on the important role of cultural development and protection of environment as the main pillars of sustainable development. one of the article's goals to make link among culture, protection of environment and sustainable development. according to the article, part of our commitment to sustainable development is to keep balance among different dimensions of development (cultural/ economic/ political/ social) considering environmental ethics

The Relation between Finnish University Students' Perceived Level of Study-Related Burnout, Perceptions of the Teaching-Learning Environment and Perceived Achievement Motivation

Science.gov (United States)

Meriläinen, Matti; Kuittinen, Matti

2014-01-01

This study examined the relation between university students' perceived level of study-related burnout (SRB) and their perceptions of the teaching-learning environment (TLE), as well as their perceived achievement motivation (AM). The data are based on a survey of nine Finnish universities in the spring of 2009. Altogether, 3035 university…

Lightning and 85-GHz MCSs in the Global Tropics

Science.gov (United States)

Toracinta, E. Richard; Zipser, E. J.

1999-01-01

Numerous observations of tropical convection show that tropical continental mesoscale convective systems (MCSs) are much more prolific lightning producers than their oceanic counterparts. Satellite-based climatologies using 85-GHz passive microwave ice-scattering signatures from the Special Sensor Microwave/Imager (SSM/I) indicate that MCSs of various size and intensity are found throughout the global tropics. In contrast, global lightning distributions show a strong land bias with an order of magnitude difference between land and ocean lightning. This is somewhat puzzling, since 85-GHz ice-scattering and the charge separation processes that lead to lightning are both thought to depend upon the existence of large graupel particles. The fact that low 85-GHz brightness temperatures are observed in tropical oceanic MCSs containing virtually no lightning leads to the postulate that tropical oceanic and tropical continental MCSs have fundamentally different hydrometeor profiles through the mixed phase region of the cloud (0 C Lightning Imaging Sensor (LIS), and the first space-borne radar, facilitates high-resolution case studies of MCS structure throughout the global tropics. An important precursor, however, is to better understand the distribution of MCSs and lightning in the tropics. With that objective in mind, this research undertakes a systematic comparison of 85-GHz-defined MCSs and lightning over the global tropics for a full year, as an initial step toward quantifying differences between land and ocean convective systems.

Tropical Agroecosystems: These habitats are misunderstood by the temperate zones, mismanaged by the tropics.

Science.gov (United States)

Janzen, D H

1973-12-21

I have listed some of the ways in which the lowland tropics are not such a warm and wonderful place for the farmer, some of the reasons why it may be unreasonable to expect him to cope with the problems, and some of the ways in which the temperate zones make his task more difficult. The tropics are very close to being a tragedy of the commons on a global scale (69, 103), and it is the temperate zone's shepherds and sheep who are among the greatest offenders (31). Given that the temperate zones have some limited amount of resources with which they are willing to repay the tropics, how can these resources best be spent? The first answer, without doubt, is education, and the incorporation of what is already known about the tropics into that education. Second should be the generation of secure psychological and physical resources for governments that show they are enthusiastic about the development of an SYTA. Third should be support of intensive research needed to generate the set of site-specific rules for specific, clearly identified SYTA's. The subject matter of youths' cultural programming is presumably determined by what they will need during the rest of their lives. A major component of this programming should be the teaching of the socioeconomic rules of a sustained-yield, nonexpanding economy, tuned to the concept of living within the carrying capacity of the country's or region's resources. Incorporating such a process into tropical school systems will cause a major upheaval, if for no other reason than that it will involve an evaluation of the country's resources, what standard of living is to be accepted by those living on them, and who is presently harvesting them. Of even greater impact, it will have to evaluate resources in terms of their ability to raise the standard of living by Y amount for X proportion of the people in the region, rather than in terms of their cash value on the world market. For such a change to be technologically successful, it will

Particular characteristics of allergic symptoms in tropical environments: follow up to 24 months in the FRAAT birth cohort study

Directory of Open Access Journals (Sweden)

Acevedo Nathalie

2012-03-01

countries. This cohort is representative of socially deprived urban areas of underdeveloped tropical countries. The collection of biological samples, data on exposure and defined phenotypes, will contribute to understand the gene/environment interactions leading to allergy inception and evolution.

Diversity and abundance of ammonia oxidizing archaea in tropical compost systems.

Science.gov (United States)

de Gannes, Vidya; Eudoxie, Gaius; Dyer, David H; Hickey, William J

2012-01-01

Composting is widely used to transform waste materials into valuable agricultural products. In the tropics, large quantities of agricultural wastes could be potentially useful in agriculture after composting. However, while microbiological processes of composts in general are well established, relatively little is known about microbial communities that may be unique to these in tropical systems, particularly nitrifiers. The recent discovery of ammonia oxidizing archaea (AOA) has changed the paradigm of nitrification being initiated solely by ammonia oxidizing bacteria. In the present study, AOA abundance and diversity was examined in composts produced from combinations of plant waste materials common in tropical agriculture (rice straw, sugar cane bagasse, and coffee hulls), which were mixed with either cow- or sheep-manure. The objective was to determine how AOA abundance and diversity varied as a function of compost system and time, the latter being a contrast between the start of the compost process (mesophilic phase) and the finished product (mature phase). The results showed that AOA were relatively abundant in composts of tropical agricultural wastes, and significantly more so than were the ammonia-oxidizing bacteria. Furthermore, while the AOA communities in the composts were predominatly group I.1b, the communities were diverse and exhibited structures that diverged between compost types and phases. These patterns could be taken as indicators of the ecophysiological diversity in the soil AOA (group I.1b), in that significantly different AOA communties developed when exposed to varying physico-chemical environments. Nitrification patterns and levels differed in the composts which, for the mature material, could have significant effects on its performance as a plant growth medium. Thus, it will also be important to determine the association of AOA (and diversity in their communities) with nitrification in these systems.

Home and School Environmental Determinants of Science Achievement of South African Students

Science.gov (United States)

Juan, Andrea; Visser, Mariette

2017-01-01

Determinants of educational achievement extend beyond the school environment to include the home environment. Both environments provide tangible and intangible resources to students that can influence science achievement. South Africa provides a context where inequalities in socio-economic status are vast, thus the environments from whence…

Tropical Deforestation.

Science.gov (United States)

Raven, Peter H.

1988-01-01

Outlines the deforestation problem and some efforts for solving the problem. Considers the impact of population growth, poverty, and ignorance. Includes a discussion of the current rapid decline in tropical forests, the consequences of destruction, and an outlook for the future. (YP)

Airborne Measurements of BrO and the Sum of HOBr and Br2 over the Tropical West Pacific from 1 to 15 Km During the CONvective TRansport of Active Species in the Tropics (CONTRAST) Experiment

Science.gov (United States)

Chen, Dexian; Huey, L. Gregory; Tanner, David J.; Salawitch, Ross J.; Anderson, Daniel C.; Wales, Pamela A.; Pan, Laura L.; Atlas, Elliot L.; Hornbrook, Rebecca S.; Apel, Eric C.;

Wave ensemble forecast system for tropical cyclones in the Australian region

Science.gov (United States)

Zieger, Stefan; Greenslade, Diana; Kepert, Jeffrey D.

2018-05-01

Forecasting of waves under extreme conditions such as tropical cyclones is vitally important for many offshore industries, but there remain many challenges. For Northwest Western Australia (NW WA), wave forecasts issued by the Australian Bureau of Meteorology have previously been limited to products from deterministic operational wave models forced by deterministic atmospheric models. The wave models are run over global (resolution 1/4∘) and regional (resolution 1/10∘) domains with forecast ranges of + 7 and + 3 day respectively. Because of this relatively coarse resolution (both in the wave models and in the forcing fields), the accuracy of these products is limited under tropical cyclone conditions. Given this limited accuracy, a new ensemble-based wave forecasting system for the NW WA region has been developed. To achieve this, a new dedicated 8-km resolution grid was nested in the global wave model. Over this grid, the wave model is forced with winds from a bias-corrected European Centre for Medium Range Weather Forecast atmospheric ensemble that comprises 51 ensemble members to take into account the uncertainties in location, intensity and structure of a tropical cyclone system. A unique technique is used to select restart files for each wave ensemble member. The system is designed to operate in real time during the cyclone season providing + 10-day forecasts. This paper will describe the wave forecast components of this system and present the verification metrics and skill for specific events.

Journal of Tropical Microbiology and Biotechnology

African Journals Online (AJOL)

The Journal of Tropical Microbiology and Biotechnology (JTMB) formerly Journal of Tropical Microbiology gives preeminence to the central role of modern biotechnology and microorganisms as tools and targets in current research, which is largely multidisciplinary. JTMB covers a broad range of topics, such as disease ...

The Role of the Tropics in Abrupt Climate Changes

Energy Technology Data Exchange (ETDEWEB)

Fedorov, Alexey [Yale University

2013-12-07

Topics addressed include: abrupt climate changes and ocean circulation in the tropics; what controls the ocean thermal structure in the tropics; a permanent El Niño in paleoclimates; the energetics of the tropical ocean.

Urgent need for warming experiments in tropical forests

Science.gov (United States)

Calaveri, Molly A.; Reed, Sasha C.; Smith, W. Kolby; Wood, Tana E.

2015-01-01

Although tropical forests account for only a fraction of the planet's terrestrial surface, they exchange more carbon dioxide with the atmosphere than any other biome on Earth, and thus play a disproportionate role in the global climate. In the next 20 years, the tropics will experience unprecedented warming, yet there is exceedingly high uncertainty about their potential responses to this imminent climatic change. Here, we prioritize research approaches given both funding and logistical constraints in order to resolve major uncertainties about how tropical forests function and also to improve predictive capacity of earth system models. We investigate overall model uncertainty of tropical latitudes and explore the scientific benefits and inevitable trade-offs inherent in large-scale manipulative field experiments. With a Coupled Model Intercomparison Project Phase 5 analysis, we found that model variability in projected net ecosystem production was nearly 3 times greater in the tropics than for any other latitude. Through a review of the most current literature, we concluded that manipulative warming experiments are vital to accurately predict future tropical forest carbon balance, and we further recommend the establishment of a network of comparable studies spanning gradients of precipitation, edaphic qualities, plant types, and/or land use change. We provide arguments for long-term, single-factor warming experiments that incorporate warming of the most biogeochemically active ecosystem components (i.e. leaves, roots, soil microbes). Hypothesis testing of underlying mechanisms should be a priority, along with improving model parameterization and constraints. No single tropical forest is representative of all tropical forests; therefore logistical feasibility should be the most important consideration for locating large-scale manipulative experiments. Above all, we advocate for multi-faceted research programs, and we offer arguments for what we consider the most

Scavenger removal: Bird and bat carcass persistence in a tropical wind farm

Science.gov (United States)

Villegas-Patraca, Rafael; Macías-Sánchez, Samuel; MacGregor-Fors, Ian; Muñoz-Robles, Carlos

2012-08-01

Energy produced by wind farms has diverse positive environmental effects, but can also be related to negative impacts, including wildlife mortality through collisions with wind turbines. Bird and bat mortality caused by collisions with wind turbines can be estimated indirectly by counting carcasses within wind farms. However, carcass removal by scavengers often biases such measurements. In this study, we identified the main scavengers removing bird and bat carcasses in a tropical wind farm. A known fate analysis was done to assess the effect of carcass type (i.e., small bird, large bird, bat), vegetation type (i.e., secondary vegetation, croplands) and season (dry and rainy seasons of 2009) on carcass persistence rates. We identified three main scavenger groups, with mammals being the most abundant group. Our results show high rates of carcass removal relative to previous studies, especially for bats; there were fewer remaining carcasses after 20 days in our tropical site than in non-tropical environments reported elsewhere. We found a higher carcass persistence rate during the rainy season than in the dry season, possibly due to a greater abundance of food resources for scavenger organisms in the rainy season. Although we found some evidence for higher persistence rates for large bird carcasses than for small bird and bat carcasses during the rainy season, overall carcass type was not a strong predictor of persistence rates. Similarly, we did not find a strong effect of vegetation type on carcass persistence rates. Results suggest that in order to estimate accurate bird and bat mortality in tropical wind farm areas, seasonality should be incorporated to correction factors of carcass removal rates.

Mapping Clearances in Tropical Dry Forests Using Breakpoints, Trend, and Seasonal Components from MODIS Time Series: Does Forest Type Matter?

NARCIS (Netherlands)

Grogan, Kenneth; Pflugmacher, Dirk; Hostert, Patrick; Verbesselt, Jan; Fensholt, Rasmus

2016-01-01

Tropical environments present a unique challenge for optical time series analysis, primarily owing to fragmented data availability, persistent cloud cover and atmospheric aerosols. Additionally, little is known of whether the performance of time series change detection is affected by diverse forest

Abiotic factors influencing tropical dry forests regeneration

Directory of Open Access Journals (Sweden)

Ceccon Eliane

2006-01-01

Full Text Available Tropical dry forests represent nearly half the tropical forests in the world and are the ecosystems registering the greatest deterioration from the anthropogenic exploitation of the land. This paper presents a review on the dynamics of tropical dry forests regeneration and the main abiotic factors influencing this regeneration, such as seasonal nature, soil fertility and humidity, and natural and anthropic disturbances. The main purpose is to clearly understand an important part of TDF succession dynamics.

Controls of Sediment Nitrogen Dynamics in Tropical Coastal Lagoons

Science.gov (United States)

Enrich-Prast, Alex; Figueiredo, Viviane; Esteves, Francisco de Assis; Nielsen, Lars Peter

2016-01-01

Sediment denitrification rates seem to be lower in tropical environments than in temperate environments. Using the isotope pairing technique, we measured actual denitrification rates in the sediment of tropical coastal lagoons. To explain the low denitrification rates observed at all study sites (<5 μmol N2 m-2 h-1), we also evaluated potential oxygen (O2) consumption, potential nitrification, potential denitrification, potential anammox, and estimated dissimilatory nitrate (NO3-) reduction to ammonium (NH4+; DNRA) in the sediment. 15NO3- and 15NH4+ conversion was measured in oxic and anoxic slurries from the sediment surface. Sediment potential O2 consumption was used as a proxy for overall mineralization activity. Actual denitrification rates and different potential nitrogen (N) oxidation and reduction processes were significantly correlated with potential O2 consumption. The contribution of potential nitrification to total O2 consumption decreased from contributing 9% at sites with the lowest sediment mineralization rates to less than 0.1% at sites with the highest rates. NO3- reduction switched completely from potential denitrification to estimated DNRA. Ammonium oxidation and nitrite (NO2-) reduction by potential anammox contributed up to 3% in sediments with the lowest sediment mineralization rates. The majority of these patterns could be explained by variations in the microbial environments from stable and largely oxic conditions at low sediment mineralization sites to more variable conditions and the prevalences of anaerobic microorganisms at high sediment mineralization sites. Furthermore, the presence of algal and microbial mats on the sediment had a significant effect on all studied processes. We propose a theoretical model based on low and high sediment mineralization rates to explain the growth, activity, and distribution of microorganisms carrying out denitrification and DNRA in sediments that can explain the dominance or coexistence of DNRA and

Optical Algorithms at Satellite Wavelengths for Total Suspended Matter in Tropical Coastal Waters

OpenAIRE

Ouillon, Sylvain; Douillet, Pascal; Petrenko, Anne; Neveux, Jacques; Dupouy, C?cile; Froidefond, Jean-Marie; Andr?fou?t, Serge; Mu?oz-Caravaca, Alain

2008-01-01

Is it possible to derive accurately Total Suspended Matter concentration or its proxy, turbidity, from remote sensing data in tropical coastal lagoon waters? To investigate this question, hyperspectral remote sensing reflectance, turbidity and chlorophyll pigment concentration were measured in three coral reef lagoons. The three sites enabled us to get data over very diverse environments: oligotrophic and sediment-poor waters in the southwest lagoon of New Caledonia, eutrophic waters in the C...

On the potential of long wavelength imaging radars for mapping vegetation types and woody biomass in tropical rain forests

Science.gov (United States)

Rignot, Eric J.; Zimmermann, Reiner; Oren, Ram

1995-01-01

In the tropical rain forests of Manu, in Peru, where forest biomass ranges from 4 kg/sq m in young forest succession up to 100 kg/sq m in old, undisturbed floodplain stands, the P-band polarimetric radar data gathered in June of 1993 by the AIRSAR (Airborne Synthetic Aperture Radar) instrument separate most major vegetation formations and also perform better than expected in estimating woody biomass. The worldwide need for large scale, updated biomass estimates, achieved with a uniformly applied method, as well as reliable maps of land cover, justifies a more in-depth exploration of long wavelength imaging radar applications for tropical forests inventories.

A record of aerobic methane oxidation in tropical Africa over the last 2.5 Ma

Science.gov (United States)

Spencer-Jones, Charlotte L.; Wagner, Thomas; Talbot, Helen M.

2017-12-01

Methane and CO2 are climatically active greenhouse gases (GHG) and are powerful drivers of rapid global warming. Comparable to the Arctic, the tropics store large volumes of labile sedimentary carbon that is vulnerable to climate change. However, little is known about this labile carbon reservoir, in particular the behaviour of high methane-producing environments (e.g. wetlands), and their role in driving or responding to past periods of global climate change. In this study, we use a microbial biomarker approach that traces continental aerobic methane oxidation (AMO) from sedimentary organic matter in deep-sea fan sediments off the Congo River to reconstruct the link between central African methane cycling and continental export during key periods of global Pleistocene warmth. We use 35-amino bacteriohopanepolyols (BHPs), specifically aminobacteriohopane-31,32,33,34-tetrol (aminotetrol) and 35-aminobacteriohopane-30,31,32,33,34-pentol (aminopentol) as diagnostic molecular markers for AMO (CH4 oxidation markers) and the prevalence of continental wetland environments. BHPs were analysed in sediments from the Congo fan (ODP 1075) dated to 2.5 Ma. High resolution studies of key warm marine isotope stages (MIS) 5, 11 and 13 are included to test the relationship between CH4 oxidation markers in sediments at different levels of elevated global atmospheric GHG. This study presents the oldest reported occurrence, to date, of 35-amino BHPs up to 200 m below sea floor (∼2.5 Ma) with no strong degradation signature observed. Low concentrations of CH4 oxidation markers identified between 1.7 Ma and 1 Ma suggest a reduction in wetland extent in tropical Africa in response to more arid environmental conditions. Correlation of high resolution CH4 oxidation marker signatures with global atmospheric GHG concentrations during MIS 5, 11 and 13 further emphasize periods of enhanced tropical C cycling. However, subsequent analysis would be required to further extrapolate the relative

Introverts, Extroverts, and Achievement in a Distance Learning Environment

Science.gov (United States)

Offir, Baruch; Bezalel, Rachel; Barth, Ingrid

2007-01-01

Although difficulties that characterize distance learning (DL) clearly have differential effects on different learners, links between barrier research and individual differences remain relatively unexplored. This study examined the relationship between cognitive style, based on Jung's (1971) theory, and achievement levels among 77 university…

Propagation Measurement on Earth-Sky Signal Effects for High Speed Train Satellite Channel in Tropical Region at Ku-Band

Directory of Open Access Journals (Sweden)

Abdulmajeed H. J. Al-Jumaily

2015-01-01

Full Text Available Recent advances in satellite communication technologies in the tropical regions have led to significant increase in the demand for services and applications that require high channel quality for mobile satellite terminals. Determination and quantification of these requirements are important to optimize service quality, particularly in the Malaysian region. Moreover, the tests on current satellite propagation models were carried out at temperate regions whose environmental characteristics are much different from those in Malaysia. This difference renders these propagation models inapplicable and irrelevant to tropical regions in general. This paper presents the link characteristics observations and performance analysis with propagation measurements done in tropical region to provide an accurate database regarding rain and power arches supply (PAs attenuations in the tropics for mobile scenarios. Hence, an extension for improving the performance assessment and analysis of satellite/transmission has been achieved. The Malaysia propagation measurement for mobile scenario (Malaysia-PMMS enables first-hand coarse estimation and attenuation analysis, because the attenuation resulting from rain and PAs becomes easily amenable for measurement. Parallel to that, the measured attenuation has been compared with that of the simulated output at noise floor level. The underlying analytical tool is validated by measurements specific at tropical region, for dynamic model of mobile satellite links operating at higher than 10 GHz.

Zooplankton resting egg banks in permanent and temporary tropical aquatic systems

Directory of Open Access Journals (Sweden)

Luciana Rabelo Araújo

Full Text Available AIM: We evaluated zooplankton resting egg banks and active communities in five coastal lagoons and in five temporary pools, aiming to compare the active and the dormant communities in such environments. As they differ in hydroperiod, we expected that pools present richer resting egg banks in comparison to those found in lagoons. METHODS: Zooplankton community was sampled twice in 2006 (lagoons and in 2010 (pools and resting egg banks were sampled once in December 2007 (lagoons and in May 2010 (pools. Resting eggs were isolated from the sediment by applying the sugar flotation method. RESULTS: In opposition to our expectation, species richness in the resting egg banks of pools did not differ from those of lagoons. Additionally, no difference was found between the active and the dormant zooplankton communities in each water body for both temporary and permanent environments. However, similarity between active and dormant communities was greater in permanent environments than it was in temporary environments. CONCLUSIONS: It seems that the diapause strategy observed in certain tropical zooplankton populations cannot be predicted based on the awareness of the environment type (permanent or temporary, since hatching cues may be species-specific.

The role of tropical cyclones in precipitation over the tropical and subtropical North America

Science.gov (United States)

Dominguez, Christian; Magaña, Victor

2018-03-01

Tropical cyclones (TCs) are essential elements of the hydrological cycle in tropical and subtropical regions. In the present study, the contribution of TCs to seasonal precipitation around the tropical and subtropical North America is examined. When TC activity over the tropical eastern Pacific (TEP) or the Intra Americas Seas (IAS) is below (above-normal), regional precipitation may be below (above-normal). However, it is not only the number of TCs what may change seasonal precipitation, but the trajectory of the systems. TCs induce intense precipitation over continental regions if they are close enough to shorelines, for instance, if the TC center is located, on average, less than 500 km-distant from the coast. However, if TCs are more remote than this threshold distance, the chances of rain over continental regions decrease, particularly in arid and semi-arid regions. In addition, a distant TC may induce subsidence or produce moisture divergence that inhibits, at least for a few days, convective activity farther away than the threshold distance. An analysis of interannual variability in the TCs that produce precipitation over the tropical and subtropical North America shows that some regions in northern Mexico, which mostly depend on this effect to undergo wet years, may experience seasonal negative anomalies in precipitation if TCs trajectories are remote. Therefore, TCs (activity and trajectories) are important modulators of climate variability on various time scales, either by producing intense rainfall or by inhibiting convection at distant regions from their trajectory. The impact of such variations on water availability in northern Mexico may be relevant, since water availability in dams recovers under the effects of TC rainfall. Seasonal precipitation forecasts or climate change scenarios for these regions should take into account the effect of TCs, if regional adaptation strategies are implemented.

Upper temperature limits of tropical marine ectotherms: global warming implications.

Directory of Open Access Journals (Sweden)

Khanh Dung T Nguyen

Full Text Available Animal physiology, ecology and evolution are affected by temperature and it is expected that community structure will be strongly influenced by global warming. This is particularly relevant in the tropics, where organisms are already living close to their upper temperature limits and hence are highly vulnerable to rising temperature. Here we present data on upper temperature limits of 34 tropical marine ectotherm species from seven phyla living in intertidal and subtidal habitats. Short term thermal tolerances and vertical distributions were correlated, i.e., upper shore animals have higher thermal tolerance than lower shore and subtidal animals; however, animals, despite their respective tidal height, were susceptible to the same temperature in the long term. When temperatures were raised by 1°C hour(-1, the upper lethal temperature range of intertidal ectotherms was 41-52°C, but this range was narrower and reduced to 37-41°C in subtidal animals. The rate of temperature change, however, affected intertidal and subtidal animals differently. In chronic heating experiments when temperature was raised weekly or monthly instead of every hour, upper temperature limits of subtidal species decreased from 40°C to 35.4°C, while the decrease was more than 10°C in high shore organisms. Hence in the long term, activity and survival of tropical marine organisms could be compromised just 2-3°C above present seawater temperatures. Differences between animals from environments that experience different levels of temperature variability suggest that the physiological mechanisms underlying thermal sensitivity may vary at different rates of warming.

Coordinated Airborne Studies in the Tropics (CAST) Field Campaign Report

Energy Technology Data Exchange (ETDEWEB)

Vaughan, Geraint [Univ. of Manchester (United Kingdom)

2016-05-01

The last field campaign held at the U.S. Department of Energy (DOE) Atmospheric Radiation Measurement (ARM) Climate Research Facility site on Manus Island, Papua New Guinea (PNG), was conducted in February 2014 as part of the Co-ordinated Airborne Studies in the Tropics (CAST) campaign. This campaign was a collaboration between the National Aeronautics and Space Administration (NASA), National Center for Atmospheric Research (NCAR), and the United Kingdom’s (UK) Natural Environment Research Council (NERC) to study the composition of the Tropical Tropopause Layer (TTL) and the impact of deep convection on this composition. There are three main areas of interest: i) transport of trace gases in the tropical atmosphere (especially short-lived halogenated compounds that can be lifted rapidly into the TTL, where they augment the stratospheric loading of these species); ii) formation of cirrus and its impact on the TTL; and iii) the upper-atmosphere water vapor budget. Overall, the aim was to improve understanding of the dynamical, radiative, and chemical role of the TTL. The Manus operation was a joint experiment between the Universities of Manchester and Cambridge and the UK National Centre for Atmospheric Science (NCAS). It consisted of two elements: an ozonesonde campaign to measure ozone vertical profiles through the TTL, and ground-based monitoring of ozone, halogenated hydrocarbons, and greenhouse gases to determine the composition of lower-boundary-layer air in the Warm Pool region. Thanks to the support from the ARM Climate Research Facility and the exemplary collaboration of ARM staff in the region, the campaign was very successful.

Insight into the product film formed on Ni-advanced weathering steel in a tropical marine atmosphere

Science.gov (United States)

Wu, Wei; Cheng, Xuequn; Hou, Huaxing; Liu, Bo; Li, Xiaogang

2018-04-01

The product film formed on Ni-advanced weathering steel in a tropical marine environment was investigated in detail through outdoor exposure by using diverse surface analysis techniques combined with electrochemical impedance spectroscopy and scanning kelvin probe measurements. The results showed that the product film was mainly composed of nanophasic goethite in the inner layer and maghemite, akaganeite, and hematite in the outer layer. Moreover, the resistance to atmospheric corrosion gradually increased from the outermost product film to the innermost film. Ni was significantly enriched in the inner layer in the form of the spinel phase NiFe2O4, which transformed lepidocrocite to fine-grained goethite, withstood the invasion of chloridion, and improved the corrosion potential of the product film in a tropical marine atmosphere.

Strategies for Improving Enterprise Standardization Management of Tropical Crop Machinery

Institute of Scientific and Technical Information of China (English)

无

2007-01-01

@@ There are two categories of tropical crop machinery. One comprises operation machinery that is used for planting, managing and harvesting tropical crops, while the other comprises process machinery for processing tropical crops. Tropical crop machinery is distinguished from other agricultural machinery by the special crops that such machinery cultivates and processes.

Air-sea interaction in the tropical Pacific Ocean

Science.gov (United States)

Allison, L. J.; Steranka, J.; Holub, R. J.; Hansen, J.; Godshall, F. A.; Prabhakara, C.

1972-01-01

Charts of 3-month sea surface temperature (SST) anomalies in the eastern tropical Pacific Ocean were produced for the period 1949 to 1970. The anomalies along the United States and South American west coasts and in the eastern tropical Pacific appeared to be oscillating in phase during this period. Similarly, the satellite-derived cloudiness for each of four quadrants of the Pacific Ocean (130 deg E to 100 deg W, 30 deg N to 25 deg S) appeared to be oscillating in phase. In addition, a global tropical cloudiness oscillation from 30 deg N to 30 deg S was noted from 1965 to 1970, by using monthly satellite television nephanalyses. The SST anomalies were found to have a good degree of correlation both positive and negative with the following monthly geophysical parameters: (1) satellite-derived cloudiness, (2) strength of the North and South Pacific semipermanent anticyclones, (3) tropical Pacific island rainfall, and (4) Darwin surface pressure. Several strong direct local and crossequatorial relationships were noted. In particular, the high degree of correlation between the tropical island rainfall and the SST anomalies (r = +0.93) permitted the derivation of SST's for the tropical Pacific back to 1905. The close occurrence of cold tropical SST and North Pacific 700-mb positive height anomalies with central United States drought conditions was noted.

The Influence of Teaching Methods and Learning Environment to the Student's Learning Achievement of Craft and Entrepreneurship Subjects at Vocational High School

Science.gov (United States)

Munawaroh

2017-01-01

This research aims to explain the influence of teacher's teaching methods and learning environment to the learning achievement in class XI with the competency of accounting expertise to the subjects of craft and entrepreneurship, according to the students, the subject was very heavy and dull. The population in this research are students in class…

Exploring Causal Models of Educational Achievement.

Science.gov (United States)

Parkerson, Jo Ann; And Others

1984-01-01

This article evaluates five causal model of educational productivity applied to learning science in a sample of 882 fifth through eighth graders. Each model explores the relationship between achievement and a combination of eight constructs: home environment, peer group, media, ability, social environment, time on task, motivation, and…

Phylogenetic classification of the world’s tropical forests

OpenAIRE

Slik, J. W. Ferry; Franklin, Janet; Arroyo-Rodríguez, Víctor; Field, Richard; Aguilar, Salomon; Aguirre, Nikolay; Ahumada, Jorge; Aiba, Shin-Ichiro; Alves, Luciana F.; K, Anitha; Avella, Andres; Mora, Francisco; Aymard C., Gerardo A.; Báez, Selene; Balvanera, Patricia

2018-01-01

Identifying and explaining regional differences in tropical forest dynamics, structure, diversity, and composition are critical for anticipating region-specific responses to global environmental change. Floristic classifications are of fundamental importance for these efforts. Here we provide a global tropical forest classification that is explicitly based on community evolutionary similarity, resulting in identification of five major tropical forest regions and their relationships: (i) Indo-...

Trees and light : tree development and morphology in relation to light availability in a tropical rain forest in French Guiana

NARCIS (Netherlands)

Sterck, F.J.

1997-01-01

Tropical rain forest trees spend their life in a heterogeneous light environment. During their life history, they may change their growth in relation to different levels of light availability. Some of their physiological processes (e.g. photosynthesis, carbon allocation, and meristern

Year 2001 Tropical Cyclones of the World

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Year 2001 Tropical Cyclones of the World poster. During calendar year 2001, fifty tropical cyclones with sustained surface winds of at least 64 knots were observed...

Year 2000 Tropical Cyclones of the World

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — Year 2000 Tropical Cyclones of the World poster. During calendar year 2000, forty-five tropical cyclones with sustained surface winds of at least 64 knots were...

How can tropical cyclones survive?

Science.gov (United States)

Smedman, Ann-Sofi

2013-04-01

How can tropical cyclones survive? It is important for understanding the development of tropical cyclones to be able to quantify the exchange of enthalpy and momentum between air and water. Air-sea fluxes are often formulated as drag CD and enthalpy CK exchange coefficients. Emanuel, 1986, derived an expression for potential intensity that depends on local environment parameters and is proportional to the ratio of enthalpy and drag coefficients. This ratio should be larger than 0.75 for a cyclone to develop. There are no direct surface measurements of CK/ CD under hurricane conditions and extrapolation from most open-ocean measurements at 25 m/s gives values of CK/ CD0.75 is in accordance with Emanuel's prediction. The high CK values are observed during situations when there is a regime shift of the structure of turbulence in the boundary layer. From spectral analysis it was found that as the boundary layer approaches neutral stratification, smaller-scale eddies become increasingly important in the turbulent transport of humidity and sensible heat and thus enhance the exchange coefficient CK. This turbulence regime is called the UVCN regime and require high wind speed, small temperature difference between air and water, sufficiently strong wind gradients and growing sea condition ( Smedman et al., 2007, Sahlee et al., 2008). What is the difference between world oceans and enclosed seas? The answer is the waves. The wave field over the open oceans is swell dominated but in enclosed seas and coastal areas swell is restricted mainly to low wind speed conditions, and swell is short lived because of short distances to the shores. When swell is present the MABL will be dominated by large eddies of zi size creating weak gradients of wind, temperature and humidity and thus small scale eddies cannot be formed leading to reduced CK-values. However, during hurricane condition the waves are expected to be young, stratification is close to neutral and gradients are sufficiently

Global demand for gold is another threat for tropical forests

International Nuclear Information System (INIS)

Alvarez-Berríos, Nora L; Mitchell Aide, T

2015-01-01

The current global gold rush, driven by increasing consumption in developing countries and uncertainty in financial markets, is an increasing threat for tropical ecosystems. Gold mining causes significant alteration to the environment, yet mining is often overlooked in deforestation analyses because it occupies relatively small areas. As a result, we lack a comprehensive assessment of the spatial extent of gold mining impacts on tropical forests. In this study, we provide a regional assessment of gold mining deforestation in the tropical moist forest biome of South America. Specifically, we analyzed the patterns of forest change in gold mining sites between 2001 and 2013, and evaluated the proximity of gold mining deforestation to protected areas (PAs). The forest cover maps were produced using the Land Mapper web application and images from the MODIS satellite MOD13Q1 vegetation indices 250 m product. Annual maps of forest cover were used to model the incremental change in forest in ∼1600 potential gold mining sites between 2001–2006 and 2007–2013. Approximately 1680 km 2 of tropical moist forest was lost in these mining sites between 2001 and 2013. Deforestation was significantly higher during the 2007–2013 period, and this was associated with the increase in global demand for gold after the international financial crisis. More than 90% of the deforestation occurred in four major hotspots: Guianan moist forest ecoregion (41%), Southwest Amazon moist forest ecoregion (28%), Tapajós–Xingú moist forest ecoregion (11%), and Magdalena Valley montane forest and Magdalena–Urabá moist forest ecoregions (9%). In addition, some of the more active zones of gold mining deforestation occurred inside or within 10 km of ∼32 PAs. There is an urgent need to understand the ecological and social impacts of gold mining because it is an important cause of deforestation in the most remote forests in South America, and the impacts, particularly in aquatic systems

Forests to fields. Restoring tropical lands to agriculture.

Science.gov (United States)

Wood, D

1993-04-01

In discussing land use in tropical forest regions, there is an emphasis on the following topics: the need for the expansion of cropping areas, the precedent for use of the tropical forest for cropping based on past use patterns, the pressure from conservationists against cropping, debunking the mythology that forests are "natural" and refuting the claims that forest clearance is not reversible, the archeological evidence of past forest use for agricultural purposes, abandonment of tropical land to forest, and rotation of forest and field. The assumption is that the way to stop food importation is to increase crop production in the tropics. Crop production can be increased through 1) land intensification or clearing new land, 2) output per unit of land increases, or 3) reallocation to agriculture land previously cleared and overgrown with tropical forest. "Temporary" reuse of land, which reverted back to tropical forest, is recommended. This reuse would ease population pressure, and benefit bioconservation, while populations stabilize and further progress is made in international plant breeding. The land would eventually be returned to a forest state. Conservation of tropical forest areas should be accomplished, after an assessment has been made of its former uses. Primary forests need to identified and conversion to farming ceased. Research needs to be directed to understanding the process of past forest regeneration, and to devising cropping systems with longterm viability. The green revolution is unsuitable for traditional cropping systems, is contrary to demands of international funding agencies for sustainability, and is not affordable by most poor farmers. Only .48 million sq. km of closed forest loss was in tropical rainforests; 6.53 million sq. km was lost from temperate forests cleared for intensive small-scale peasant farming. The use of tropical forest land for farming has some benefits; crops in the wetter tropics are perennial, which would "reduce

Glutamine and glutamic acid supplementation enhances performance of broiler chickens under the hot and humid tropical condition

Directory of Open Access Journals (Sweden)

Joshua O. Olubodun

2015-02-01

Full Text Available Day-old (day 1 commercial broiler chickens were fed i basal diet (control, ii basal diet +0.5% AminoGut (AG, or iii basal diet +1% AG from 1 to 42 d of age under the hot and humid tropical environment. AminoGut is a commercial dietary supplement containing a mixture of L-glutamine (Gln and L-glutamic (Glu acid. Weight gain and feed conversion ratio during the starter (1 to 21 d and overall (1 to 42 d periods improved linearly and quadratically with AG supplementation when compared to control. Supplementing birds with AG significantly reduced overall mortality rate. At 21 and 42 d of age, intestinal (duodenum and ileum villi height and crypt depth showed both linear and quadratic positive responses to AG supplementation. Intestinal amylase activity increased linearly and quadratically on d 21, and linearly only on d 42. In conclusion, Gln and Glu supplementation was beneficial in improving the growth performance and survivability of broiler chickens under the hot and humid tropical environment.

Effects of the thermal environment on animal production in the tropics

International Nuclear Information System (INIS)

Robertshaw, D.

1986-01-01

The problems of heat stress in animal production can be solved by an interdisciplinary approach whereby the engineer, animal scientist and animal physiologist can all interact. By understanding the principles associated with heat flow between an animal and its environment it is possible to predict the potential success of an animal production system. This review analyses the nature of the thermal environment and the way in which it can affect production. Methods for alleviating heat stress are also described. (author)

Distribution of tropical tropospheric water vapor

Science.gov (United States)

Sun, De-Zheng; Lindzen, Richard S.

1993-01-01

Utilizing a conceptual model for tropical convection and observational data for water vapor, the maintenance of the vertical distribution of the tropical tropospheric water vapor is discussed. While deep convection induces large-scale subsidence that constrains the turbulent downgradient mixing to within the convective boundary layer and effectively dries the troposphere through downward advection, it also pumps hydrometeors into the upper troposphere, whose subsequent evaporation appears to be the major source of moisture for the large-scale subsiding motion. The development of upper-level clouds and precipitation from these clouds may also act to dry the outflow, thus explaining the low relative humidity near the tropopause. A one-dimensional model is developed to simulate the mean vertical structure of water vapor in the tropical troposphere. It is also shown that the horizontal variation of water vapor in the tropical troposphere above the trade-wind boundary layer can be explained by the variation of a moisture source that is proportional to the amount of upper-level clouds. Implications for the nature of water vapor feedback in global warming are discussed.

Mediterranean climate and some tropical teleconnections

International Nuclear Information System (INIS)

Alpert, P.; Price, C.; Krichak, S.; Saaroni, H.; Osetinsky, I.; Barkan, J.; Kishcha, P.; Ziv, B.

2006-01-01

Some strong natural fluctuations of climate in the Eastern Mediterranean (EM) region are shown to be connected to the major tropical systems, e.g., El Ni no Southern Oscillation, South Asian Monsoon and hurricanes. Modelling of the severe floods suggests a relation to tropical hurricanes. For a specific event, high-resolution modelling of the severe flood on December 3-5, 2001 in Israel suggests a relation to hurricane Olga. In order to understand the factors governing the Eastern Mediterranean climate variability in the summer season, the relationship between extreme summer temperatures and the South Asian Monsoon was examined. Other tropical factors, like the Red Sea Trough system and the Saharan dust, also contribute to the Mediterranean climate variability

Biohydrogen Production from Hydrolysates of Selected Tropical Biomass Wastes with Clostridium Butyricum

Science.gov (United States)

Dan Jiang; Fang, Zhen; Chin, Siew-Xian; Tian, Xiao-Fei; Su, Tong-Chao

2016-06-01

Biohydrogen production has received widespread attention from researchers in industry and academic fields. Response surface methodology (RSM) was applied to evaluate the effects of several key variables in anaerobic fermentation of glucose with Clostridium butyrium, and achieved the highest production rate and yield of hydrogen. Highest H2 yield of 2.02 mol H2/mol-glucose was achieved from 24 h bottle fermentation of glucose at 35 °C, while the composition of medium was (g/L): 15.66 glucose, 6.04 yeast extract, 4 tryptone, 3 K2HPO4, 3 KH2PO4, 0.05 L-cysteine, 0.05 MgSO4·7H2O, 0.1 MnSO4·H2O and 0.3 FeSO4·7H2O, which was very different from that for cell growth. Sugarcane bagasse and Jatropha hulls were selected as typical tropical biomass wastes to produce sugars via a two-step acid hydrolysis for hydrogen production. Under the optimized fermentation conditions, H2 yield (mol H2/mol-total reducing sugar) was 2.15 for glucose, 2.06 for bagasse hydrolysate and 1.95 for Jatropha hull hydrolysate in a 3L fermenter for 24 h at 35 °C, with H2 purity of 49.7-64.34%. The results provide useful information and basic data for practical use of tropical plant wastes to produce hydrogen.

Biodiversity can help prevent malaria outbreaks in tropical forests.

Directory of Open Access Journals (Sweden)

Gabriel Zorello Laporta

Full Text Available BACKGROUND: Plasmodium vivax is a widely distributed, neglected parasite that can cause malaria and death in tropical areas. It is associated with an estimated 80-300 million cases of malaria worldwide. Brazilian tropical rain forests encompass host- and vector-rich communities, in which two hypothetical mechanisms could play a role in the dynamics of malaria transmission. The first mechanism is the dilution effect caused by presence of wild warm-blooded animals, which can act as dead-end hosts to Plasmodium parasites. The second is diffuse mosquito vector competition, in which vector and non-vector mosquito species compete for blood feeding upon a defensive host. Considering that the World Health Organization Malaria Eradication Research Agenda calls for novel strategies to eliminate malaria transmission locally, we used mathematical modeling to assess those two mechanisms in a pristine tropical rain forest, where the primary vector is present but malaria is absent. METHODOLOGY/PRINCIPAL FINDINGS: The Ross-Macdonald model and a biodiversity-oriented model were parameterized using newly collected data and data from the literature. The basic reproduction number ([Formula: see text] estimated employing Ross-Macdonald model indicated that malaria cases occur in the study location. However, no malaria cases have been reported since 1980. In contrast, the biodiversity-oriented model corroborated the absence of malaria transmission. In addition, the diffuse competition mechanism was negatively correlated with the risk of malaria transmission, which suggests a protective effect provided by the forest ecosystem. There is a non-linear, unimodal correlation between the mechanism of dead-end transmission of parasites and the risk of malaria transmission, suggesting a protective effect only under certain circumstances (e.g., a high abundance of wild warm-blooded animals. CONCLUSIONS/SIGNIFICANCE: To achieve biological conservation and to eliminate

Effects of Gender, Mathematics Anxiety and Achievement Motivation on College Students’ Achievement in Mathematics

Directory of Open Access Journals (Sweden)

Ajogbeje Oke James

2013-07-01

Full Text Available The urge to excel or perform maximally in mathematics varies from individual to individual because achievement motivation is often developed or learnt during socialization and learning experiences. The study examined the relationship between College of Education students’ achievement motivation and mathematics achievement, correlation coefficient between mathematics anxiety and college students’ achievement motivation as well as mathematics anxiety and mathematics achievement. The sample, 268 College of Education students offering mathematics as one of their subject combination, was selected using purposive sampling techniques. Three research instruments namely: Mathematics Anxiety Scale (MAS, Achievement Motivation Scale (AMS and Mathematics Achievement Test (MAT were used to collect data for the study. Data collected for the study were analyzed using correlational analysis and ANOVA. The results showed that a significantly low negative correlation coefficient existed between mathematics anxiety and mathematics achievement. There is a negative and significant correlation coefficient between mathematics anxiety and achievement motivation. Similarly, a positive and significant correlation coefficient also exists between achievement motivation and mathematics achievement. Based on the findings of the study, it was recommended that mathematics teachers should adopt activity based strategies and conducive learning environment in order to reduce college students’ anxieties in mathematics learning.

Tropical Pacific Observing for the Next Decade

Science.gov (United States)

Legler, David M.; Hill, Katherine

2014-06-01

More than 60 scientists and program officials from 13 countries met at the Scripps Institution of Oceanography for the Tropical Pacific Observing System (TPOS) 2020 Workshop. The workshop, although motivated in part by the dramatic decline of NOAA's Tropical Atmosphere Ocean (TAO) buoy reporting from mid-2012 to early 2014 (see http://www.bloomberg.com/news/2014-03-07/aging-el-nino-buoys-getting-fixed-as-weather-forecasts-at-risk.html), evaluated the needs for tropical Pacific observing and initiated efforts to develop a more resilient and integrative observing system for the future.

Is voluntary certification of tropical agricultural commodities achieving sustainability goals for small-scale producers? A review of the evidence

Science.gov (United States)

DeFries, Ruth S.; Fanzo, Jessica; Mondal, Pinki; Remans, Roseline; Wood, Stephen A.

2017-03-01

Over the last several decades, voluntary certification programs have become a key approach to promote sustainable supply chains for agricultural commodities. These programs provide premiums and other benefits to producers for adhering to environmental and labor practices established by the certifying entities. Following the principles of Cochrane Reviews used in health sciences, we assess evidence to evaluate whether voluntary certification of tropical agricultural commodities (bananas, cocoa, coffee, oil palm, and tea) has achieved environmental benefits and improved economic and social outcomes for small-scale producers at the level of the farm household. We reviewed over 2600 papers in the peer-review literature and identified 24 cases of unique combinations of study area, certification program, and commodity in 16 papers that rigorously analyzed differences between treatment (certified households) and control groups (uncertified households) for a wide range of response variables. Based on analysis of 347 response variables reported in these papers, we conclude that certification is associated on average with positive outcomes for 34% of response variables, no significant difference for 58% of variables, and negative outcomes for 8% of variables. No significant differences were observed for different categories of responses (environmental, economic and social) or for different commodities (banana, coffee and tea), except negative outcomes were significantly less for environmental than other outcome categories (p = 0.01). Most cases (20 out of 24) investigated coffee certification and response variables were inconsistent across cases, indicating the paucity of studies to conduct a conclusive meta-analysis. The somewhat positive results indicate that voluntary certification programs can sometimes play a role in meeting sustainable development goals and do not support the view that such programs are merely greenwashing. However, results also indicate that

The Geological Trace Of The 1932 Tsunamis In The Tropical Jalisco-Colima Coast, Mexico

Science.gov (United States)

Ramirez-Herrera, M.; Blecher, L.; Goff, J. R.; Corona, N.; Chague-Goff, C.; Lagos, M.; Hutchinson, I.; Aguilar, B.; Goguitchaichrili, A.; Machain-Castillo, M. L.; Rangel, V.; Zawadzki, A.; Jacobsen, G.

2013-05-01

The study and preservation of tsunami deposits have being challenging in humid tropical environments. While tsunami deposits have been widely studied at temperate latitudes, few studies assess this problem in tropical environments due to the difficulties intrinsic to these places (e.g. tsunami deposit preservation, post-burial changes in a tropical environment, mangrove vegetation, difficult access, wildlife, among others). Here we assess the problem of tsunami-deposits preservation on the Jalisco-Colima tropical coast of Mexico, which parallels the more than 1000-km long Mexican subduction, where historical accounts indicate the occurrence of two significant tsunamis on June 3 and 22, 1932 (Corona and Ramírez-Herrera, 2012a, Valdivia et al., 2012). However, up to date, no geological evidence of these events has been reported. We present geological evidence of two large tsunamis related to the June 3, M 8.2 earthquake, and the June 22, Ms 6.9 landslide-triggering event of 1932 (Corona and Ramírez-Herrera, 2012a, b). A multiproxy approach was applied to unravel the nature of anomalous sand units and sharp basal contacts in the stratigraphy of a number of sites at Palo Verde estuary, El Tecuán swales and marsh, and La Manzanilla swales, on the Jalisco-Colima coast. Lines of evidence including historical, geomorphological, stratigraphic, grain size, organic matter content, microfossils (diatoms and foraminifera), geochemical content, magnetic susceptibility and AMS analyses, together with dating (210Pb and 14C), and modeling, corroborate the presence of tsunami deposits of both the 3 June 1932 tsunami at El Tecuán and La Manzanilla, and the 22 June 1932 tsunami at Palo Verde. Further evidence of earlier tsunamis, at least four events, is also evident in the stratigraphy. Work in progress should reveal the chronology of the earliest tsunamis and their origin. Corona, N., M.T. Ramirez-Herrera. (2012a) Mapping and historical reconstruction of the great Mexican 1932

Compendium of NASA Data Base for the Global Tropospheric Experiment's Pacific Exploratory Mission-Tropics B (PEM-Tropics B). Volume 1; DC-8

Science.gov (United States)

Scott, A. Donald, Jr.; Kleb, Mary M.; Raper, James L.

2000-01-01

This report provides a compendium of NASA aircraft data that are available from NASA's Global Tropospheric Experiment's (GTE) Pacific Exploratory Mission-Tropics B (PEM-Tropics B) conducted in March and April 1999. PEM-Tropics B was conducted during the southern-tropical wet season when the influence from biomass burning observed in PEM-Tropics A was minimal. Major deployment sites were Hawaii, Kiritimati (Christmas Island), Tahiti, Fiji, and Easter Island. The broad goals of PEM-Tropics B were to improved understanding of the oxidizing power of the atmosphere and the processes controlling sulfur aerosol formation and to establish baseline values for chemical species that are directly coupled to the oxidizing power and aerosol loading of the troposphere. The purpose of this document is to provide a representation of aircraft data that will be available in archived format via NASA Langley's Distributed Active Archive Center (DAAC) or are available through the GTE Project Office archive. The data format is not intended to support original research/analysis, but to assist the reader in identifying data that are of interest.

Sediment transport dynamics in steep, tropical volcanic catchments

Science.gov (United States)

Birkel, Christian; Solano Rivera, Vanessa; Granados Bolaños, Sebastian; Brenes Cambronero, Liz; Sánchez Murillo, Ricardo; Geris, Josie

2017-04-01

material (> 100m3 per year) to the stream network, (ii) rainfall events that exceed a threshold of around 30mm/h rain intensity activate superficial flow pathways with associated mobilization of sediments (laminar erosion). However, the erosion processes are spatially very heterogeneous and mostly linked to finer material properties of the soils that mostly developed on more highly weathered bedrock. (iii) extreme events (return period > 50 years) mainly erode the streambed and banks cutting deeper into the bedrock and re-distribute massive amounts of material in the form of removed old alluvial deposits and new deposits created elsewhere, (iv) recovery after such extreme events in the form of fine material transport even during low intensity rainfall towards pre-event rainfall intensity thresholds takes only about two to three months. We conclude that the study catchment geomorphologically represents a low-resistance, but highly resilient catchment that quickly recovers after the impact of extreme rainfall-runoff events. The latter was indicated by a different pre and post-event hysteretic pattern of sediment-runoff dynamics and associated different material properties. The combined use of high-temporal resolution monitoring with spatially distributed surveys provided new insights into the fluvial geomorphology of steep, volcanic headwater catchments with potential to establish more complete sediment budgets and time-scales of land-forming processes of such highly dynamic environments in the humid tropics.

Spatial and temporal distribution of tropical biomass burning

Science.gov (United States)

Hao, Wei Min; Liu, Mei-Huey

1994-12-01

A database for the spatial and temporal distribution of the amount of biomass burned in tropical America, Africa, and Asia during the late 1970s is presented with a resolution of 5° latitude × 5° longitude. The sources of burning in each grid cell have been quantified. Savanna fires, shifting cultivation, deforestation, fuel wood use, and burning of agricultural residues contribute about 50, 24, 10, 11, and 5%, respectively, of total biomass burned in the tropics. Savanna fires dominate in tropical Africa, and forest fires dominate in tropical Asia. A similar amount of biomass is burned from forest and savanna fires in tropical America. The distribution of biomass burned monthly during the dry season has been derived for each grid cell using the seasonal cycles of surface ozone concentrations. Land use changes during the last decade could have a profound impact on the amount of biomass burned and the amount of trace gases and aerosol particles emitted.

Studies on the growth and reproduction of cattle in the tropics

International Nuclear Information System (INIS)

Frisch, J.E.

1990-01-01

The results of a number of studies that had the long term aim of increasing the productivity of cattle in the tropics are reported. The studies were conducted on the B (Brahman), HS (interbred Hereford x Shorthorn), F 1 BX (first cross B x HS) and F n BX (interbred B x HS) lines. These breeds were used to demonstrate the origins of the heterosis that occurs in both the realized growth and the reproductive rate of Bos indicus x Bos taurus. Genetic and environmental factors that limit the realized reproductive rates were also investigated. The reproductive rate of cows of each breed that differed in lactation status during the breeding season was compared in contrasting environments. It was shown that the main limitation to HS achieving high realized reproductive rates was of environmental origin. For B cows, the main limitation was associated with the stress of lactation. Unsuccessful attempts were made to overcome this limitation by using progesterone releasing intravaginal devices alone or in combination with temporary calf weaning to try to induce a fertile oestrus. Improvement of the realized reproductive rates in the HS line was achieved by increasing their resistance to environmental stresses. The prospects for increasing the realized reproductive rate of maiden heifers by increasing their live weight at the start of their first breeding season were also investigated. About half of the heifers of each breed were implanted with the synthetic growth promotant Synovex 'H' on three occasions before the start of the breeding season. Although the live weight of all breeds increased in response to Synovex 'H', the magnitude of the response was dependent on the presence or absence of parasite control. Previously implanted heifers had a lower pregnancy rate than non-implanted heifers. 4 refs, 6 tabs

Extinction risk escalates in the tropics.

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Jana C Vamosi

Full Text Available The latitudinal biodiversity gradient remains one of the most widely recognized yet puzzling patterns in nature. Presently, the high level of extinction of tropical species, referred to as the "tropical biodiversity crisis", has the potential to erode this pattern. While the connection between species richness, extinction, and speciation has long intrigued biologists, these interactions have experienced increased poignancy due to their relevancy to where we should concentrate our conservation efforts. Natural extinction is a phenomenon thought to have its own latitudinal gradient, with lower extinction rates in the tropics being reported in beetles, birds, mammals, and bivalves. Processes that have buffered ecosystems from high extinction rates in the past may also buffer ecosystems against disturbance of anthropogenic origin. While potential parallels between historical and present-day extinction patterns have been acknowledged, they remain only superficially explored and plant extinction patterns have been particularly neglected. Studies on the disappearances of animal species have reached conflicting conclusions, with the rate of extinction appearing either higher or lower in species richness hotspots. Our global study of extinction risk in vascular plants finds disproportionately higher extinction risk in tropical countries, even when indicators of human pressure (GDP, population density, forest cover change are taken into account. Our results are at odds with the notion that the tropics represent a museum of plant biodiversity (places of historically lowered extinction and we discuss mechanisms that may reconcile this apparent contradiction.

Extinction risk escalates in the tropics.

Science.gov (United States)

Vamosi, Jana C; Vamosi, Steven M

2008-01-01

The latitudinal biodiversity gradient remains one of the most widely recognized yet puzzling patterns in nature. Presently, the high level of extinction of tropical species, referred to as the "tropical biodiversity crisis", has the potential to erode this pattern. While the connection between species richness, extinction, and speciation has long intrigued biologists, these interactions have experienced increased poignancy due to their relevancy to where we should concentrate our conservation efforts. Natural extinction is a phenomenon thought to have its own latitudinal gradient, with lower extinction rates in the tropics being reported in beetles, birds, mammals, and bivalves. Processes that have buffered ecosystems from high extinction rates in the past may also buffer ecosystems against disturbance of anthropogenic origin. While potential parallels between historical and present-day extinction patterns have been acknowledged, they remain only superficially explored and plant extinction patterns have been particularly neglected. Studies on the disappearances of animal species have reached conflicting conclusions, with the rate of extinction appearing either higher or lower in species richness hotspots. Our global study of extinction risk in vascular plants finds disproportionately higher extinction risk in tropical countries, even when indicators of human pressure (GDP, population density, forest cover change) are taken into account. Our results are at odds with the notion that the tropics represent a museum of plant biodiversity (places of historically lowered extinction) and we discuss mechanisms that may reconcile this apparent contradiction.

Design of Tropical Flowers Environmental Parameters Wireless Monitoring System Based on MSP430

Directory of Open Access Journals (Sweden)

Huang Jian-Qing

2016-01-01

Full Text Available Considering the importance of real-time monitoring tropical flower environment parameters, the paper designs a wireless monitoring system based on MSP430F149 for tropical flower growing parameters. The proposed system uses sensor nodes to obtain data of temperature, humidity and light intensity, sink node to collect data from sensor nodes through wireless sensor network, and monitoring center to process data downloaded from the sink node through RS232 serial port. The node hardware platform is composed of a MSP430F149 processor, AM2306 and NHZD10AI sensors used to adopt temperature, humidity and light intensity data, and an nRF905 RF chip used to receive and send data. The node software, operated in IAR Embedded Workbench, adopts C Language to do node data collection and process, wireless transmission and serial port communication. The software of monitoring center develops in VB6.0, which can provide vivid and explicit real-time monitoring platform for flower farmers.

Optimum Tilt Angle at Tropical Region

Directory of Open Access Journals (Sweden)

S Soulayman

2015-02-01

Full Text Available : One of the important parameters that affect the performance of a solar collector is its tilt angle with the horizon. This is because of the variation of tilt angle changes the amount of solar radiation reaching the collector surface. Meanwhile, is the rule of thumb, which says that solar collector Equator facing position is the best, is valid for tropical region? Thus, it is required to determine the optimum tilt as for Equator facing and for Pole oriented collectors. In addition, the question that may arise: how many times is reasonable for adjusting collector tilt angle for a definite value of surface azimuth angle? A mathematical model was used for estimating the solar radiation on a tilted surface, and to determine the optimum tilt angle and orientation (surface azimuth angle for the solar collector at any latitude. This model was applied for determining optimum tilt angle and orientation in the tropical zones, on a daily basis, as well as for a specific period. The optimum angle was computed by searching for the values for which the radiation on the collector surface is a maximum for a particular day or a specific period. The results reveal that changing the tilt angle 12 times in a year (i.e. using the monthly optimum tilt angle maintains approximately the total amount of solar radiation near the maximum value that is found by changing the tilt angle daily to its optimum value. This achieves a yearly gain in solar radiation of 11% to 18% more than the case of a solar collector fixed on a horizontal surface.

The Role of Herbivory in Structuring Tropical Seagrass Ecosystem Service Delivery

Science.gov (United States)

Scott, Abigail L.; York, Paul H.; Duncan, Clare; Macreadie, Peter I.; Connolly, Rod M.; Ellis, Megan T.; Jarvis, Jessie C.; Jinks, Kristin I.; Marsh, Helene; Rasheed, Michael A.

2018-01-01

Seagrass meadows support key ecosystem services, via provision of food directly for herbivores, and indirectly to their predators. The importance of herbivores in seagrass meadows has been well-documented, but the links between food webs and ecosystem services in seagrass meadows have not previously been made explicit. Herbivores interact with ecosystem services – including carbon sequestration, cultural values, and coastal protection. Interactions can be positive or negative and depend on a range of factors including the herbivore identity and the grazing type and intensity. There can be unintended consequences from management actions based on a poor understanding of trade-offs that occur with complex seagrass-herbivore interactions. Tropical seagrass meadows support a diversity of grazers spanning the meso-, macro-, and megaherbivore scales. We present a conceptual model to describe how multiple ecosystem services are influenced by herbivore pressure in tropical seagrass meadows. Our model suggests that a balanced ecosystem, incorporating both seagrass and herbivore diversity, is likely to sustain the broadest range of ecosystem services. Our framework suggests the pathway to achieve desired ecosystem services outcomes requires knowledge on four key areas: (1) how size classes of herbivores interact to structure seagrass; (2) desired community and management values; (3) seagrass responses to top–down and bottom–up controls; (4) the pathway from intermediate to final ecosystem services and human benefits. We suggest research should be directed to these areas. Herbivory is a major structuring influence in tropical seagrass systems and needs to be considered for effective management of these critical habitats and their services. PMID:29487606

Progress in tropical isotope dendroclimatology

Science.gov (United States)

Evans, M. N.; Schrag, D. P.; Poussart, P. F.; Anchukaitis, K. J.

2005-12-01

The terrestrial tropics remain an important gap in the growing high resolution proxy network used to characterize the mean state and variability of the hydrological cycle. Here we review early efforts to develop a new class of proxy paleorainfall/humidity indicators using intraseasonal to interannual-resolution stable isotope data from tropical trees. The approach invokes a recently published model of oxygen isotopic composition of alpha-cellulose, rapid methods for cellulose extraction from raw wood, and continuous flow isotope ratio mass spectrometry to develop proxy chronological, rainfall and growth rate estimates from tropical trees, even those lacking annual rings. Isotopically-derived age models may be confirmed for modern intervals using trees of known age, radiocarbon measurements, direct measurements of tree diameter, and time series replication. Studies are now underway at a number of laboratories on samples from Costa Rica, northwestern coastal Peru, Indonesia, Thailand, New Guinea, Paraguay, Brazil, India, and the South American Altiplano. Improved sample extraction chemistry and online pyrolysis techniques should increase sample throughput, precision, and time series replication. Statistical calibration together with simple forward modeling based on the well-observed modern period can provide for objective interpretation of the data. Ultimately, replicated data series with well-defined uncertainties can be entered into multiproxy efforts to define aspects of tropical hydrological variability associated with ENSO, the meridional overturning circulation, and the monsoon systems.

The future of tropical forests.

Science.gov (United States)

Wright, S Joseph

2010-05-01

Five anthropogenic drivers--land use change, wood extraction, hunting, atmospheric change, climate change--will largely determine the future of tropical forests. The geographic scope and intensity of these five drivers are in flux. Contemporary land use change includes deforestation (approximately 64,000 km(2) yr(-1) for the entire tropical forest biome) and natural forests regenerating on abandoned land (approximately 21,500 km(2) yr(-1) with just 29% of the biome evaluated). Commercial logging is shifting rapidly from Southeast Asia to Africa and South America, but local fuelwood consumption continues to constitute 71% of all wood production. Pantropical rates of net deforestation are declining even as secondary and logged forests increasingly replace old-growth forests. Hunters reduce frugivore, granivore and browser abundances in most forests. This alters seed dispersal, seed and seedling survival, and hence the species composition and spatial template of plant regeneration. Tropical governments have responded to these local threats by protecting 7% of all land for the strict conservation of nature--a commitment that is only matched poleward of 40 degrees S and 70 degrees N. Protected status often fails to stop hunters and is impotent against atmospheric and climate change. There are increasing reports of stark changes in the structure and dynamics of protected tropical forests. Four broad classes of mechanisms might contribute to these changes. Predictions are developed to distinguish among these mechanisms.

Ecological impacts of tropical forest fragmentation: how consistent are patterns in species richness and nestedness?

Science.gov (United States)

Hill, Jane K; Gray, Michael A; Khen, Chey Vun; Benedick, Suzan; Tawatao, Noel; Hamer, Keith C

2011-11-27

Large areas of tropical forest now exist as remnants scattered across agricultural landscapes, and so understanding the impacts of forest fragmentation is important for biodiversity conservation. We examined species richness and nestedness among tropical forest remnants in birds (meta-analysis of published studies) and insects (field data for fruit-feeding Lepidoptera (butterflies and moths) and ants). Species-area relationships were evident in all four taxa, and avian and insect assemblages in remnants typically were nested subsets of those in larger areas. Avian carnivores and nectarivores and predatory ants were more nested than other guilds, implying that the sequential loss of species was more predictable in these groups, and that fragmentation alters the trophic organization of communities. For butterflies, the ordering of fragments to achieve maximum nestedness was by fragment area, suggesting that differences among fragments were driven mainly by extinction. In contrast for moths, maximum nestedness was achieved by ordering species by wing length; species with longer wings (implying better dispersal) were more likely to occur at all sites, including low diversity sites, suggesting that differences among fragments were driven more strongly by colonization. Although all four taxa exhibited high levels of nestedness, patterns of species turnover were also idiosyncratic, and thus even species-poor sites contributed to landscape-scale biodiversity, particularly for insects.

Ocean cleaning stations under a changing climate: biological responses of tropical and temperate fish-cleaner shrimp to global warming.

Science.gov (United States)

Rosa, Rui; Lopes, Ana Rita; Pimentel, Marta; Faleiro, Filipa; Baptista, Miguel; Trübenbach, Katja; Narciso, Luis; Dionísio, Gisela; Pegado, Maria Rita; Repolho, Tiago; Calado, Ricardo; Diniz, Mário

2014-10-01

Cleaning symbioses play an important role in the health of certain coastal marine communities. These interspecific associations often occur at specific sites (cleaning stations) where a cleaner organism (commonly a fish or shrimp) removes ectoparasites/damaged tissue from a 'client' (a larger cooperating fish). At present, the potential impact of climate change on the fitness of cleaner organisms remains unknown. This study investigated the physiological and biochemical responses of tropical (Lysmata amboinensis) and temperate (L. seticaudata) cleaner shrimp to global warming. Specifically, thermal limits (CTMax), metabolic rates, thermal sensitivity, heat shock response (HSR), lipid peroxidation [malondialdehyde (MDA) concentration], lactate levels, antioxidant (GST, SOD and catalase) and digestive enzyme activities (trypsin and alkaline phosphatase) at current and warming (+3 °C) temperature conditions. In contrast to the temperate species, CTMax values decreased significantly from current (24-27 °C) to warming temperature conditions (30 °C) for the tropical shrimp, where metabolic thermal sensitivity was affected and the HSR was significantly reduced. MDA levels in tropical shrimp increased dramatically, indicating extreme cellular lipid peroxidation, which was not observed in the temperate shrimp. Lactate levels, GST and SOD activities were significantly enhanced within the muscle tissue of the tropical species. Digestive enzyme activities in the hepatopancreas of both species were significantly decreased by warmer temperatures. Our data suggest that the tropical cleaner shrimp will be more vulnerable to global warming than the temperate Lysmata seticaudata; the latter evolved in a relatively unstable environment with seasonal thermal variations that may have conferred greater adaptive plasticity. Thus, tropical cleaning symbioses may be challenged at a greater degree by warming-related anthropogenic forcing, with potential cascading effects on the health

Environmental dynamics and carbon accumulation rate of a tropical peatland in Central Sumatra, Indonesia

Science.gov (United States)

Hapsari, Kartika Anggi; Biagioni, Siria; Jennerjahn, Tim C.; Reimer, Peter Meyer; Saad, Asmadi; Achnopha, Yudhi; Sabiham, Supiandi; Behling, Hermann

2017-08-01

Tropical peatlands are important for the global carbon cycle as they store 18% of the total global peat carbon. As they are vulnerable to changes in temperature and precipitation, a rapidly changing environment endangers peatlands and their carbon storage potential. Understanding the mechanisms of peatland carbon accumulation from studying past developments may, therefore, help to assess the future role of tropical peatlands. Using a multi-proxy palaeoecological approach, a peat core taken from the Sungai Buluh peatland in Central Sumatra has been analyzed for its pollen and spore, macro charcoal and biogeochemical composition. The result suggests that peat and C accumulation rates were driven mainly by sea level change, river water level, climatic variability and anthropogenic activities. It is also suggested that peat C accumulation in Sungai Buluh is correlated to the abundance of Freycinetia, Myrtaceae, Calophyllum, Stemonuraceae, Ficus and Euphorbiaceae. Sungai Buluh has reasonable potential for being a future global tropical peat C sinks. However, considering the impact of rapid global climate change in addition to land-use change following rapid economic growth in Indonesia, such potential may be lost. Taking advantage of available palaeoecological records and advances made in Quaternary studies, some considerations for management practice such as identification of priority taxa and conservation sites are suggested.

Coexistence of Dunes and Humid Conditions at Titan's Tropics

Science.gov (United States)

Radebaugh, Jani; Lorenz, R. D.; Lunine, J. I.; Kirk, R. L.; Ori, G. G.; Farr, T. G.; Malaska, M.; Le Gall, A.; Liu, Z. Y. C.; Encrenaz, P. J.; Paillou, P.; Hayes, A.; Lopes, R. M. C.; Turtle, E. P.; Wall, S. D.; Stofan, E. R.; Wood, C. A.; Cassini RADAR Team

2012-10-01

At Titan's equatorial latitudes there are tens of thousands of dunes, a landform typical of desert environments where sand does not become anchored by vegetation or fluids. Model climate simulations predict generally dry conditions at the equator and humid conditions near the poles of Titan, where lakes of methane/ethane are found. However, moderate relative methane humidity was observed at the Huygens landing site, recent rainfall was seen by Cassini ISS near the Belet Sand Sea, and a putative transient lake in Shangri-La was observed by Cassini VIMS, all of which indicate abundant fluids may be present, at least periodically, at Titan's equatorial latitudes. Terrestrial observations and studies demonstrate dunes can exist and migrate in conditions of high humidity. Active dunes are found in humid climates, indicating the movement of sand is not always prohibited by the presence of fluids. Sand mobility is related to precipitation, evaporation and wind speed and direction. If dune surfaces become wetted by rainfall or rising subsurface fluids, they can become immobilized. However, winds can act to dry the uppermost layers, freeing sands for saltation and enabling dune migration in wet conditions. Active dunes are found in tropical NE Brazil and NE Australia, where there are alternating dry and wet periods, a condition possible for Titan's tropics. Rising and falling water levels lead to the alteration of dune forms, mainly from being anchored by vegetation, but also from cementation by carbonates or clays. Studies of Titan's dunes, which could undergo anchoring of organic sediments by hydrocarbon fluids, could inform the relative strength of vegetation vs. cementation at humid dune regions on Earth. Furthermore, a comprehensive survey of dune morphologies near regions deemed low by SARTopo and stereo, where liquids may collect in wet conditions, could reveal if bodies of liquid have recently existed at Titan's tropics.

Marine bioinvasions: Differences in tropical copepod communities between inside and outside a port

Science.gov (United States)

Soares, Marcelo de Oliveira; Campos, Carolina Coelho; Santos, Nívia Maria Oliveira; Barroso, Hortência de Sousa; Mota, Erika Maria Targino; Menezes, Maria Ozilea Bezerra de; Rossi, Sergio; Garcia, Tatiane Martins

2018-04-01

The difficulty of detecting non-indigenous species (NIS) in marine environments is an "invisible problem" in areas where plankton monitoring does not occur. In this study, we investigated the dominance of the NIS Temora turbinata and copepod community structure in two tropical marine habitats: inside an offshore port, which had turbid and calm waters, and outside the port, which was more hydrodynamic. Our study area was on the northeast coast of Brazil. We found 17 taxa of Copepoda, which were dominated by T. turbinata and the congener, T. stylifera. The high average density of the NIS (21.03 ind./m3) was in stark contrast with that of the native copepods (0.01-3.27 ind./m3). The NIS density was negatively correlated with the species richness and evenness of the native community, was significantly higher inside the port than outside, and was positively correlated with phytoplankton density. A multivariate analysis revealed that there was a significant difference in copepod community structure between inside and outside the port; outside the port, the community was more diverse, and the native T. stylifera was more abundant. We found that tropical copepod communities inside an offshore port have low diversity, and probably have little biotic resistance against NIS invasions. Our results, combined with those previously obtained, highlight the need to study the spatial distributions of NIS and native species in pelagic environments.

Floristics and biogeography of vegetation in seasonally dry tropical regions

DEFF Research Database (Denmark)

Dexter, K.G.; Smart, B.; Baldauf, C.

2015-01-01

To provide an inter-continental overview of the floristics and biogeography of drought-adapted tropical vegetation formations, we compiled a dataset of inventory plots in South America (n=93), Africa (n=84), and Asia (n=92) from savannas (subject to fire), seasonally dry tropical forests (not...... similar vegetation formations (e.g. savannas) are floristically highly dissimilar. Neotropical moist forest, savanna and seasonally dry tropical forest are floristically distinct, but elsewhere there is no clear floristic division of savanna and seasonally dry tropical forest, though moist and dry...... of the ecology, biology and conservation of savannas and seasonally dry tropical forests may be difficult....

Development of Tropical Lowland Peat Forest Phasic Community Zonations in the Kota Samarahan-Asajaya area, West Sarawak, Malaysia

Directory of Open Access Journals (Sweden)

Mohamad Tarmizi Mohamad

2016-01-01

Full Text Available Logging observations of auger profiles (Tarmizi, 2014 indicate a vertical, downwards, general decrease of peat humification levels with depth in a tropical lowland peat forest in the Kota Samarahan-Asajaya area in the region of West Sarawak (Malaysia. Based on pollen analyses and field observations, the studied peat profiles can be interpreted as part of a progradation deltaic succession. Continued regression of sea levels, gave rise to the development of peat in a transitional mangrove to floodplain/floodbasin environment, followed by a shallow, topogenic peat depositional environment with riparian influence at approximately 2420 ± 30 years B.P. (until present time. The inferred peat vegetational succession reached Phasic Community I at approximately 2380 ± 30 years B.P. and followed by Phasic Community II at approximately 1780 ± 30 years B.P., towards the upper part of the present, ombrogenic, peat profile. Observations of the presence of large, hollow, Shorea type trees, supports that successive vegetational zonation of the tropical lowland peat dome may have reached Phasic Community II. Some pollen types were found that are also known to occur in the inferred vegetational zonation of Phasic Community III and IV or higher. Pollen analyses indicate that estuarine and deltaic, brackish to saline water influence may have gradually ceased at approximately 0.5 m below the lithological boundary between peat and underlying soil (floodplain deposit in the tropical lowland peat basin.

Evolution of body size, vision, and biodiversity of coral-associated organisms: evidence from fossil crustaceans in cold-water coral and tropical coral ecosystems.

Science.gov (United States)

Klompmaker, Adiël A; Jakobsen, Sten L; Lauridsen, Bodil W

2016-06-16

Modern cold-water coral and tropical coral environments harbor a highly diverse and ecologically important macrofauna of crustaceans that face elevated extinction risks due to reef decline. The effect of environmental conditions acting on decapod crustaceans comparing these two habitats is poorly understood today and in deep time. Here, we compare the biodiversity, eye socket height as a proxy for eye size, and body size of decapods in fossil cold-water and tropical reefs that formed prior to human disturbance. We show that decapod biodiversity is higher in fossil tropical reefs from The Netherlands, Italy, and Spain compared to that of the exceptionally well-preserved Paleocene (Danian) cold-water reef/mound ecosystem from Faxe (Denmark), where decapod diversity is highest in a more heterogeneous, mixed bryozoan-coral habitat instead of in coral and bryozoan-dominated facies. The relatively low diversity at Faxe was not influenced substantially by the preceding Cretaceous/Paleogene extinction event that is not apparent in the standing diversity of decapods in our analyses, or by sampling, preservation, and/or a latitudinal diversity gradient. Instead, the lower availability of food and fewer hiding places for decapods may explain this low diversity. Furthermore, decapods from Faxe are larger than those from tropical waters for half of the comparisons, which may be caused by a lower number of predators, the delayed maturity, and the increased life span of crustaceans in deeper, colder waters. Finally, deep-water specimens of the benthic crab Caloxanthus from Faxe exhibit a larger eye socket size compared to congeneric specimens from tropical reefs, suggesting that dim light conditions favored the evolution of relatively large eyes. The results suggest a strong habitat control on the biodiversity of crustaceans in coral-associated environments and that the diversity difference between deep, cold-water reefs and tropical reefs evolved at least ~63 million years ago

Tropical Journal of Pharmaceutical Research: About this journal

African Journals Online (AJOL)

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An empirical framework for tropical cyclone climatology

Energy Technology Data Exchange (ETDEWEB)

Kang, Nam-Young [Korea Meteorological Administration, Seoul (Korea, Republic of); Florida State University, Tallahassee, FL (United States); Elsner, James B. [Florida State University, Tallahassee, FL (United States)

2012-08-15

An empirical approach for analyzing tropical cyclone climate is presented. The approach uses lifetime-maximum wind speed and cyclone frequency to induce two orthogonal variables labeled ''activity'' and ''efficiency of intensity''. The paired variations of activity and efficiency of intensity along with the opponent variations of frequency and intensity configure a framework for evaluating tropical cyclone climate. Although cyclone activity as defined in this framework is highly correlated with the commonly used exponent indices like accumulated cyclone energy, it does not contain cyclone duration. Empirical quantiles are used to determine threshold intensity levels, and variant year ranges are used to find consistent trends in tropical cyclone climatology. In the western North Pacific, cyclone activity is decreasing despite increases in lifetime-maximum intensity. This is due to overwhelming decreases in cyclone frequency. These changes are also explained by an increasing efficiency of intensity. The North Atlantic shows different behavior. Cyclone activity is increasing due to increasing frequency and, to a lesser extent, increasing intensity. These changes are also explained by a decreasing efficiency of intensity. Tropical cyclone trends over the North Atlantic basin are more consistent over different year ranges than tropical cyclone trends over the western North Pacific. (orig.)

7 CFR 1437.505 - Application for payment for the tropical region.

Science.gov (United States)

2010-01-01

... 7 Agriculture 10 2010-01-01 2010-01-01 false Application for payment for the tropical region. 1437... DISASTER ASSISTANCE PROGRAM Determining Coverage in the Tropical Region § 1437.505 Application for payment for the tropical region. (a) For producers of covered tropical crops in Guam, Virgin Islands, American...

Chapter 50: history of tropical neurology.

Science.gov (United States)

Ogunniyi, Adesola

2010-01-01

Tropical neurology began less than two centuries ago. Consumption of dietary toxins predominated at the beginning and gave birth to the geographic entity. The story moved from lathyrism through Jamaican neuropathy to cassava-induced epidemic neuropathy, which was contrasted with Konzo, also associated with cassava. Other tropical diseases enumerated with chronological details include: Chaga's diseases, kwashiorkor, Madras type of motor neuron disease, atlanto-axial dislocation, Burkitt's lymphoma and Kuru, associated with cannibalism among the Fore linguistic group in New Guinea. More recent documentation includes the Cuban neuropathy in 1991 with an epidemic of visual loss and neuropathy, Anaphe venata entomophagy in Nigeria presenting as seasonal ataxia, and neurological aspects of the human immunodeficiency virus infection complete the picture. With time, professional associations were formed and the pioneers were given prominence. The World Federation of Neurology featured Geographic Neurology as a theme in 1977 and Tropical Neurology was given prominence at its 1989 meeting in New Delhi, India. The situation remains unchanged with regards to rare diseases like Meniere's, multiple sclerosis, hereditary disorders. However, with westernization and continued urbanization, changing disease patterns are being observed and tropical neurology may depart from dietary toxins to more western world-type disorders.

Tropics accelerate the evolution of hybrid male sterility in Drosophila.

Science.gov (United States)

Yukilevich, Roman

2013-06-01

Understanding the evolutionary mechanisms that facilitate speciation and explain global patterns of species diversity has remained a challenge for decades. The most general pattern of species biodiversity is the latitudinal gradient, whereby species richness increases toward the tropics. Although such a global pattern probably has a multitude of causes, recent attention has focused on the hypothesis that speciation and the evolution of reproductive isolation occur faster in the tropics. Here, I tested this prediction using a dataset on premating and postzygotic isolation between recently diverged Drosophila species. Results showed that while the evolution of premating isolation was not greater between tropical Drosophila relative to nontropical species, postzygotic isolation evolved faster in the tropics. In particular, hybrid male sterility was much greater among tropical Drosophila compared to nontropical species pairs of similar genetic age. Several testable explanations for the novel pattern are discussed, including greater role for sterility-inducing bacterial endosymbionts in the tropics and more intense sperm-sperm competition or sperm-egg sexual conflict in the tropics. The results imply that processes of speciation in the tropics may evolve at different rates or may even be somewhat different from those at higher latitudes. © 2013 The Author(s). Evolution © 2013 The Society for the Study of Evolution.

Alkali-resistant glass fiber reinforced high strength concrete in simulated aggressive environment

International Nuclear Information System (INIS)

Kwan, W.H.; Cheah, C.B.; Ramli, M.; Chang, K.Y.

2018-01-01

The durability of the alkali-resistant (AR) glass fiber reinforced concrete (GFRC) in three simulated aggresive environments, namely tropical climate, cyclic air and seawater and seawater immersion was investigated. Durability examinations include chloride diffusion, gas permeability, X-ray diffraction (XRD) and scanning electron microscopy examination (SEM). The fiber content is in the range of 0.6 % to 2.4 %. Results reveal that the specimen containing highest AR glass fiber content suffered severe strength loss in seawater environment and relatively milder strength loss under cyclic conditions. The permeability property was found to be more inferior with the increase in the fiber content of the concrete. This suggests that the AR glass fiber is not suitable for use as the fiber reinforcement in concrete is exposed to seawater. However, in both the tropical climate and cyclic wetting and drying, the incorporation of AR glass fiber prevents a drastic increase in permeability. [es

Biogenic VOC Emissions from Tropical Landscapes

Science.gov (United States)

Guenther, A.; Greenberg, J.; Harley, P.; Otter, L.; Vanni Gatti, L.; Baker, B.

2003-04-01

Biogenic VOC have an important role in determining the chemical composition of atmosphere. As a result, these compounds are important for visibility, biogeochemical cycling, climate and radiative forcing, and the health of the biosphere. Tropical landscapes are estimated to release about 80% of total global biogenic VOC emissions but have been investigated to lesser extent than temperate regions. Tropical VOC emissions are particularly important due to the strong vertical transport and the rapid landuse change that is occurring there. This presentation will provide an overview of field measurements of biogenic VOC emissions from tropical landscapes in Amazonia (Large-scale Biosphere-atmosphere experiment in Amazonia, LBA) Central (EXPRESSO) and Southern (SAFARI 2000) Africa, Asia and Central America. Flux measurement methods include leaf-scale (enclosure measurements), canopy-scale (above canopy tower measurements), landscape-scale (tethered balloon), and regional-scale (aircraft measurements) observations. Typical midday isoprene emission rates for different landscapes vary by more than a factor of 20 with the lowest emissions observed from degraded forests. Emissions of alpha-pinene vary by a similar amount with the highest emissions associated with landscapes dominated by light dependent monoterpene emitting plants. Isoprene emissions tend to be higher for neotropical forests (Amazon and Costa Rica) in comparison to Africa and Asian tropical forests but considerable differences are observed within regions. Strong seasonal variations were observed in both the Congo and the Amazon rainforests with peak emissions during the dry seasons. Substantial emissions of light dependent monoterpenes, methanol and acetone are characteristic of at least some tropical landscapes.

Compendium of NASA Data Base for the Global Tropospheric Experiment's Pacific Exploratory Mission - Tropics B (PEM-Tropics B). Volume 2; P-3B

Science.gov (United States)

Scott, A. Donald, Jr.; Kleb, Mary M.; Raper, James L.

2000-01-01

This report provides a compendium of NASA aircraft data that are available from NASA's Global Tropospheric Experiment's (GTE) Pacific Exploratory Mission-Tropics B (PEM-Tropics B) conducted in March and April 1999. PEM-Tropics B was conducted during the southern-tropical wet season when the influence from biomass burning observed in PEM-Tropics A was minimal. Major deployment sites were Hawaii, Kiritimati (Christmas Island), Tahiti, Fiji, and Easter Island. The broad goals of PEM-Tropics B were to improved understanding of the oxidizing power of the atmosphere and the processes controlling sulfur aerosol formation and to establish baseline values for chemical species that are directly coupled to the oxidizing power and aerosol loading of the troposphere. The purpose of this document is to provide a representation of aircraft data that will be available in archived format via NASA Langley's Distributed Active Archive Center (DAAC) or are available through the GTE Project Office archive. The data format is not intended to support original research/analysis, but to assist the reader in identifying data that are of interest.

Tropical Rainfall Measuring Mission: Monitoring the Global Tropics for 3 Years and Beyond. 1.1

Science.gov (United States)

Shepherd, Marshall; Starr, David OC. (Technical Monitor)

2001-01-01

The Tropical Rainfall Measuring Mission (TRMM) was launched in November 1997 as a joint U.S.-Japanese mission to advance understanding of the global energy and water cycle by providing distributions of rainfall and latent heating over the global tropics. As a part of NASA's Earth System Enterprise, TRMM seeks to understand the mechanisms through which changes in tropical rainfall influence global circulation. Additionally, a goal is to improve the ability to model these processes in order to predict global circulations and rainfall variability at monthly and longer time scales. Such understanding has implications for assessing climate processes related to El Nino/La Nina and Global Warming. TRMM has also provided unexpected and exciting new knowledge and applications in areas related to hurricane monitoring, lightning, pollution, hydrology, and other areas. This CD-ROM includes a self-contained PowerPoint presentation that provides an overview of TRMM and significant science results; a set of data movies or animation; and listings of current TRMM-related publications in the literature.

Design basis tropical cyclone for nuclear power plants

International Nuclear Information System (INIS)

1984-01-01

The general characteristics of tropical cyclones are discussed in this Safety Guide, with particular emphasis on their pressure and wind structures in the light of available data. General methods are given for the evaluation of the relevant parameters of a Probable Maximum Tropical Cyclone (PMTC), which can be used as the Design Basis Tropical Cyclone (DBTC); these parameters then serve as inputs for the derivation of a design basis surge and a design basis wind. A possible method is also given for the evaluation of the PMTC pressure and wind field based on an approach valid primarily for a particular region. This method depends on the results of a theoretical study on the tropical cyclone structure and makes use of a large amount of data, including aircraft reconnaissance observations for 170 most intense tropical cyclones near the coast of Japan, Taiwan and the Philippines for the period 1960-1974, as well as detailed analyses of all the extreme storms along the Gulf of Mexico and the east coast of the USA during 1900-1978, for the determination of the necessary parameters

Effect of nitrogen on partitioning and yield in grain sorghum under differing environmental conditions in the semi-arid tropics

International Nuclear Information System (INIS)

Muchow, R.C.

1990-01-01

The effect of nitrogen (N) supply on the relative contributions of pre- and post-anthesis net above-ground biomass accumulation and N uptake to grain-yield and grain N concentration was examined in four contrasting environments in semi-arid tropical Australia. The four environments had different radiation and temperature regimes, and varying levels of water deficit. The grain-yield achieved under high N supply ranged from 156 to 621 g m −2 (on an oven-dry basis). In all but the lowest-yielding environment, there was substantial biomass accumulation during grain-filling and it increased with N application. Only in the lowest-yielding environment was there substantial mobilization of pre-anthesis biomass to grain. Biomass mobilization was not affected by N application. Nitrogen uptake during grain-filling was unresponsive to N application, and was small relative to total N uptake during the life-cycle. Mobilization of pre-anthesis N to the grain was much more significant. In all but the lowest-yielding environment, N mobilization increased with N application. Grain-yield under variable N supply and differing environmental conditions was not dependent on the proportions of pre- and post-anthesis growth. However, grain-yield was proportional to biomass at maturity over the entire yield range in this study and variability in biomass accounted for 95% of the variance in grain-yield. Similarly, grain N concentration was not related to the proportions of pre- and post-anthesis N uptake, but variability in total N uptake accounted for 92% of the variance in grain N accumulation. Consequently, there was no differential effect of N supply or environmental factors on yield physiology that could not be explained by their effect on biomass and N uptake. (author)

Refuge behaviour from outdoor thermal environmental stress and seasonal differences of thermal sense in tropical urban climate

Science.gov (United States)

Kurazumi, Y.; Ishii, J.; Fukagawa, K.; Kondo, E.; Aruninta, A.

2017-12-01

Thermal sensation affects body temperature regulation. As a starting point for behavioral body temperature regulation taken to improve from a poor thermal environment to a more pleasant environment, thermal sense of thermal environment stimulus is important. The poupose of this sutudy is to use the outdoor thermal environment evaluation index ETFe to quantify effects on thermal sensations of the human body of a tropical region climate with small annual temperature differences, and to examine seasonal differences in thermal sensation. It was found temperature preferences were lower in the winter season than in the dry season, and that a tolerance for higher temperatures in the dry season than in the winter season. It was found effects of seasonal differences of the thermal environment appear in quantitative changes in thermal sensations. It was found that effects of seasonal differences of the thermal environment do not greatly affect quantitative changes in thermal comfort.

Contaminants in tropical island streams and their biota.

Science.gov (United States)

Buttermore, Elissa N; Cope, W Gregory; Kwak, Thomas J; Cooney, Patrick B; Shea, Damian; Lazaro, Peter R

2018-02-01

Environmental contamination is problematic for tropical islands due to their typically dense human populations and competing land and water uses. The Caribbean island of Puerto Rico (USA) has a long history of anthropogenic chemical use, and its human population density is among the highest globally, providing a model environment to study contaminant impacts on tropical island stream ecosystems. Polycyclic Aromatic Hydrocarbons, historic-use chlorinated pesticides, current-use pesticides, Polychlorinated Biphenyls (PCBs), and metals (mercury, cadmium, copper, lead, nickel, zinc, and selenium) were quantified in the habitat and biota of Puerto Rico streams and assessed in relation to land-use patterns and toxicological thresholds. Water, sediment, and native fish and shrimp species were sampled in 13 rivers spanning broad watershed land-use characteristics during 2009-2010. Contrary to expectations, freshwater stream ecosystems in Puerto Rico were not severely polluted, likely due to frequent flushing flows and reduced deposition associated with recurring flood events. Notable exceptions of contamination were nickel in sediment within three agricultural watersheds (range 123-336ppm dry weight) and organic contaminants (PCBs, organochlorine pesticides) and mercury in urban landscapes. At an urban site, PCBs in several fish species (Mountain Mullet Agonostomus monticola [range 0.019-0.030ppm wet weight] and American Eel Anguilla rostrata [0.019-0.031ppm wet weight]) may pose human health hazards, with concentrations exceeding the U.S. Environmental Protection Agency (EPA) consumption limit for 1 meal/month. American Eel at the urban site also contained dieldrin (range island-wide; only mercury at one site (an urban location) exceeded EPA's consumption limit of 3 meals/month for this species. These results comprise the first comprehensive island-wide contaminant assessment of Puerto Rico streams and biota and provide natural resource and public health agencies here and

Contaminants in tropical island streams and their biota

Science.gov (United States)

Buttermore, Elissa N.; Cope, W. Gregory; Kwak, Thomas J.; Cooney, Patrick B.; Shea, Damian; Lazaro, Peter R.

2018-01-01

Environmental contamination is problematic for tropical islands due to their typically dense human populations and competing land and water uses. The Caribbean island of Puerto Rico (USA) has a long history of anthropogenic chemical use, and its human population density is among the highest globally, providing a model environment to study contaminant impacts on tropical island stream ecosystems. Polycyclic Aromatic Hydrocarbons, historic-use chlorinated pesticides, current-use pesticides, Polychlorinated Biphenyls (PCBs), and metals (mercury, cadmium, copper, lead, nickel, zinc, and selenium) were quantified in the habitat and biota of Puerto Rico streams and assessed in relation to land-use patterns and toxicological thresholds. Water, sediment, and native fish and shrimp species were sampled in 13 rivers spanning broad watershed land-use characteristics during 2009–2010. Contrary to expectations, freshwater stream ecosystems in Puerto Rico were not severely polluted, likely due to frequent flushing flows and reduced deposition associated with recurring flood events. Notable exceptions of contamination were nickel in sediment within three agricultural watersheds (range 123–336 ppm dry weight) and organic contaminants (PCBs, organochlorine pesticides) and mercury in urban landscapes. At an urban site, PCBs in several fish species (Mountain Mullet Agonostomus monticola [range 0.019–0.030 ppm wet weight] and American Eel Anguilla rostrata [0.019–0.031 ppm wet weight]) may pose human health hazards, with concentrations exceeding the U.S. Environmental Protection Agency (EPA) consumption limit for 1 meal/month. American Eel at the urban site also contained dieldrin (range lipid content) and may be most suitable for human consumption island-wide; only mercury at one site (an urban location) exceeded EPA's consumption limit of 3 meals/month for this species. These results comprise the first comprehensive island-wide contaminant assessment of Puerto Rico

Where are the tropical plants? A call for better inclusion of tropical plants in studies investigating and predicting the effects of climate change

Directory of Open Access Journals (Sweden)

Kenneth J Feeley

2016-01-01

Full Text Available Tropical plant species are systematically underrepresented in large-scale analyses or synthesis looking at the potential effects of global climate change.  The reason being that we simply don’t know enough about the distributions and ecologies of most tropical plant species to predict their fate under climate change. This gaping hole in our knowledge is extremely worrisome given the high diversity of tropical plants, the crucial roles that they play in supporting global diversity and ecosystem function, and the elevated threats that climate change may pose to tropical species in general.  

Achieving High Resolution Timer Events in Virtualized Environment.

Science.gov (United States)

Adamczyk, Blazej; Chydzinski, Andrzej

2015-01-01

Virtual Machine Monitors (VMM) have become popular in different application areas. Some applications may require to generate the timer events with high resolution and precision. This however may be challenging due to the complexity of VMMs. In this paper we focus on the timer functionality provided by five different VMMs-Xen, KVM, Qemu, VirtualBox and VMWare. Firstly, we evaluate resolutions and precisions of their timer events. Apparently, provided resolutions and precisions are far too low for some applications (e.g. networking applications with the quality of service). Then, using Xen virtualization we demonstrate the improved timer design that greatly enhances both the resolution and precision of achieved timer events.

Logistic Regression and Path Analysis Method to Analyze Factors influencing Students’ Achievement

Science.gov (United States)

Noeryanti, N.; Suryowati, K.; Setyawan, Y.; Aulia, R. R.

2018-04-01

Students' academic achievement cannot be separated from the influence of two factors namely internal and external factors. The first factors of the student (internal factors) consist of intelligence (X1), health (X2), interest (X3), and motivation of students (X4). The external factors consist of family environment (X5), school environment (X6), and society environment (X7). The objects of this research are eighth grade students of the school year 2016/2017 at SMPN 1 Jiwan Madiun sampled by using simple random sampling. Primary data are obtained by distributing questionnaires. The method used in this study is binary logistic regression analysis that aims to identify internal and external factors that affect student’s achievement and how the trends of them. Path Analysis was used to determine the factors that influence directly, indirectly or totally on student’s achievement. Based on the results of binary logistic regression, variables that affect student’s achievement are interest and motivation. And based on the results obtained by path analysis, factors that have a direct impact on student’s achievement are students’ interest (59%) and students’ motivation (27%). While the factors that have indirect influences on students’ achievement, are family environment (97%) and school environment (37).

Tropical wetlands, climate, and land-use change: adaptation and mitigation opportunities

Science.gov (United States)

Randy Kolka; D. Murdiyarso; J. B. Kauffman; Richard Birdsey

2016-01-01

Tropical wetland ecosystems, especially mangroves and peatlands, are carbon (C) rich ecosystems. Globally, tropical mangroves store about 20 PgC, however, deforestation has contributed 10 % of the total global emissions from tropical deforestation, even though mangroves account for only about 0.7 % of the world’s tropical forest area (Donato et al. 2011). Meanwhile,...

A Late Holocene Record of Human Impact in the Tropical Lowlands of the Mexican Gulf Coast: Lago Verde.

Science.gov (United States)

Socorro, L.; Sosa, S.; Caballero, M.; Rodriguez, A.; Ortega, B.

2005-05-01

Lago Verde is a maar lake (18 36 43 N; 95 20 52 W) located on the Gulf Coast of Mexico in "Los Tuxtlas" region. The area was cover by tropical rain forest and is part of the core area of the earliest Mesoamerican cultures. A 6 m sediment core was obtained in order to document vegetation and lake level history of this area. Lago Verde is a shallow, eutrophic lake (max. 4 m), the natural vegetation has been removed and grasslands with some tropical trees such Bursera grows around the lake. According with the radiocarbon chronology the sequence covers the last 2500 yr BP. At the base of the sequence low abundance of tropical trees is record, with intermediate lake levels. A sudden change in the pollen stratigraphy occurs at ca. 2000 yr BP, with important presence of Poaceae, Ambrosia and Cheno.-Am. along with Zea mays indicating human activity in the area. This is associated with a change in limnological conditions, recording turbid, shallow environments. This pollen signals correlates with dry phases in Yucatan, suggesting that this dry climatic signal probably had effect on an ample area of Mexico. However, at 1200 yr BP, no more Zea mays pollen is recovered suggesting the abandonment of the area. Lake levels recover as well as the tropical forest. The last 150 yr BP is characterized by the reduction in the pollen of tropical forest trees, presence of Zea mays, increased erosion rates, turbidity and eutrophication in the lake, all related to deforestation.

Application of Polar Organic Chemical Integrative Sampler (POCIS) to monitor emerging contaminants in tropical waters.

Science.gov (United States)

Bayen, Stéphane; Segovia, Elvagris; Loh, Lay Leng; Burger, David F; Eikaas, Hans S; Kelly, Barry C

2014-06-01

Tools specifically validated for tropical environments are needed to accurately describe the behavior of chemical contaminants in tropical ecosystems. In the present study, sampling rates (Rs) were determined for the commercial pharmaceutical-type Polar Organic Chemical Integrative Sampler (POCIS) with a 45.8cm(2) exposure surface for 35 Pharmaceutically Active Compounds (PhACs) and Endocrine Disrupting Compounds (EDCs), of which eight compounds (albuterol, atorvastatin, diltiazem, dilantin, enalapril, norfluoxetine, risperidone and warfarin) were reported for the first time. These sampling rates were measured in an outdoor laboratory calibration setup to best capture diurnal tropical temperature variations (29±3°C). The effect of stirring and salinity was investigated. For all compounds, the sampling rates were higher under stirred conditions as compared to quiescent conditions. Calibration results in the presence of 30g sodium chloride support that the effects of salinity on POCIS sampling rates are compound-specific. Comparisons between Time-Weight Average (TWA) water concentrations using POCIS and spot sample levels in the field (2 lake and 1 mangrove estuary sites) are presented. Results showed that POCIS TWA concentrations were in agreement with spot sample concentrations for these aquatic systems. Results indicate that POCIS can be used to effectively measure the TWA concentration for a range of PhACs and EDCs in tropical waters. However, based on the results from mass balance and field deployments, POCIS did not appear suitable for compounds with a low mass balance recovery during calibration (e.g. triclosan and linuron in this study). Copyright © 2014 Elsevier B.V. All rights reserved.

Exploration for uranium in a tropical country: a case history in the Central African Republic

International Nuclear Information System (INIS)

Molina, P.

1983-01-01

A total-count aerial radiometric survey carried out in the Central African Republic, in a wet tropical environment, led to the discovery of several anomalies, which were found to be bound to laterites overlying in Archean, quarzite-micaschist metamorphic series. Ground verification included several techniques: regional photogeology, radiometry and stream sediment geochemistry. Each anomalous spot was studied in detail by radiometric and geochemical grids, local topographic study and trenching through the lateritic profile. (author)

Topic 2.0: Tropical cyclone formation and extratropical transition

OpenAIRE

Harr, Patrick A.

2010-01-01

Approved for public release; distribution is unlimited In this section, progress since ITWC-VI on research, observations and forecasting of tropical cyclone formation and extratropical transition is summarized. While tropical cyclone formation and extratropical transition are stages at opposite ends of the tropical cyclone lifecycle, significant lack of understanding remains in relation to processes associated with each stage. Formation and extratropical transition involve interactions a...

Prey type and foraging ecology of Sanderlings Calidris alba in different climate zones: are tropical areas more favourable than temperate sites?

Directory of Open Access Journals (Sweden)

Kirsten Grond

2015-08-01

Full Text Available Sanderlings (Calidris alba are long-distance migratory shorebirds with a non-breeding range that spans temperate and tropical coastal habitats. Breeding in the High Arctic combined with non-breeding seasons in the tropics necessitate long migrations, which are energetically demanding. On an annual basis, the higher energy expenditures during migration might pay off if food availability in the tropics is higher than at temperate latitudes. We compared foraging behaviour of birds at a north temperate and a tropical non-breeding site in the Netherlands and Ghana, respectively. In both cases the birds used similar habitats (open beaches, and experienced similar periods of daylight, which enabled us to compare food abundance and availability, and behavioural time budgets and food intake. During the non-breeding season, Sanderlings in the Netherlands spent 79% of their day foraging; in Ghana birds spent only 38% of the daytime period foraging and the largest proportion of their time resting (58%. The main prey item in the Netherlands was the soft-bodied polychaete Scolelepis squamata, while Sanderlings in Ghana fed almost exclusively on the bivalve Donax pulchellus, which they swallowed whole and crushed internally. Average availability of polychaete worms in the Netherlands was 7.4 g ash free dry mass (AFDM m−2, which was one tenth of the 77.1 g AFDM m−2 estimated for the beach in Ghana. In the tropical environment of Ghana the Sanderlings combined relatively low energy requirements with high prey intake rates (1.64 mg opposed to 0.13 mg AFDM s−1 for Ghana and the Netherlands respectively. Although this may suggest that the Ghana beaches are the most favourable environment, processing the hard-shelled bivalve (D. pulchellus which is the staple food could be costly. The large amount of daytime spent resting in Ghana may be indicative of the time needed to process the shell fragments, rather than indicate rest.