• Title/Summary/Keyword: Tropical conditions

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Effect of Naked Neck Gene on Immune Competence, Serum Biochemical and Carcass Traits in Chickens under a Tropical Climate

  • Rajkumar, U.;Reddy, B.L.N.;Rajaravindra, K.S.;Niranjan, M.;Bhattacharya, T.K.;Chatterjee, R.N.;Panda, A.K.;Reddy, M.R.;Sharma, R.P.
    • Asian-Australasian Journal of Animal Sciences
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    • v.23 no.7
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    • pp.867-872
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    • 2010
  • A comprehensive study was undertaken to evaluate the effect of naked neck (Na) gene on immune competence, serum biochemical parameters and carcass quality traits in three genotypes (NaNa, Nana and nana) of the naked neck chicken under a tropical climate (Southern India). Sixty day-old chicks (20 from each genotype) were selected randomly and reared under similar environmental conditions up to eight weeks of age. The cell mediated immune (CMI) response to phytohaemoagglutinin-P (PHA-P) was significantly higher ($p{\lgq}0.01$) in NaNa and Nana genotypes compared to nana birds. The humoral response as measured by antibody titre to sheep red blood cells (SRBC) was also significantly higher in NaNa. The total cholesterol, LDL and VLDL cholesterol levels were significantly ($p{\leq}0.01$) lower whereas HDL cholesterol level was significantly higher in NaNa and Nana compared to nana genotype. The presence of Na allele significantly increased the live weight and dressing yield, and decreased the feather cover and abdominal fat. The naked neck genotypes (NaNa/Nana) performed better than the normal (nana) siblings for almost all the traits studied.

Case Study of Variations in the Tropical Atmospheric Boundary Layer According to the Surface Conditions (지표 조건에 따른 열대 대기경계층 변화의 사례 연구)

  • Byoung-Hyuk Kwon
    • Journal of Environmental Science International
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    • v.10 no.5
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    • pp.337-342
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    • 2001
  • The Rondonia Boundary Layer Experiment (RBLE-II) was conceived to collect data the atmospheric boundary layer over two representative surface in the Amazon region of Brazil; tropical forest and a deforested, pasture area. The present study deals with the observations of atmospheric boundary layer growth and decay. Although the atmospheric boundary layer measurements made in RBLE-II were not made simultaneously over the two different surface types, some insights can be gained from analysing and comparing with their structure. The greater depth of the nocturnal boundary layer at the forest site may be due to influence of mechanical turbulence. The pasture site is aerodynamically smoother and so the downward turbulent diffusion will be much pasture than over the forest. The development of the convective boundary layer is stronger over the pasture than over the forest. The influence of the sensible heat flux is important but may be not enough to explain the difference completely. It seems that energy advection may occur from the wet and colder(forest) to the dry and warmer area(pasture), rapidly breaking up the nocturnal inversion. Such advection can explain the abrupt growth of the convective boundary layer at the pasture site during the early morning.

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Root System Development of Rice in Different Soil Moisture Conditions in Uganda Field.

  • Hatanaka, Keisuke;Shin, Yabuta;Minoru, Yoshino;Miyamoto, Kisho;Jun-Ichi, Sakagami
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2019.09a
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    • pp.21-21
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    • 2019
  • Approximately 80% of rice field in Africa conducts in rainfed (Nishimaki 2017). The rice is damaged by water stress because fields like rainfed lowland repeat drying and humidity of soil because of impossible water control. Then water stress is one of the major limiting factors for decreasing rice yield. So, in initial growth stage, quick and efficient root development is useful way to avoid drought stress by getting water from deeper soil layer with roots elongation as the hypothesis. Daniel et al (2016) reported that NERICA1 and NERICA4 show different patterns of root plasticity for drought stress. NERICA1 has greater development of lateral root in shallow soil layer, while NERICA4 has greater development in deep root elongation to underground. This study was aimed to evaluate the effect of root development in initial growth stage on growing NERICA1 and NERICA4 under different soil moisture condition in rainfed lowland rice field. They were grown in same water condition until 35 days after sowing (35DAS), and after that each varieties were separated in dry and wet condition. The rice plants were grown until 60DAS. The results of soil moisture, the root extension angle, shoot dry weight and bleeding ratio showed that NERICA4 can mitigate dry stress from surface soil compered to NERICA1.

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Wind profiles of tropical cyclones as observed by Doppler wind profiler and anemometer

  • He, Y.C.;Chan, P.W.;Li, Q.S.
    • Wind and Structures
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    • v.17 no.4
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    • pp.419-433
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    • 2013
  • This paper investigates the vertical profiles of horizontal mean wind speed and direction based on the synchronized measurements from a Doppler radar profiler and an anemometer during 16 tropical cyclones at a coastal site in Hong Kong. The speed profiles with both open sea and hilly exposures were found to follow the log-law below a height of 500 m. Above this height, there was an additional wind speed shear in the profile for hilly upwind terrain. The fitting parameters with both the power-law and the log-law varied with wind strength. The direction profiles were also sensitive to local terrain setups and surrounding topographic features. For a uniform open sea terrain, wind direction veered logarithmically with height from the surface level up to the free atmospheric altitude of about 1200 m. The accumulated veering angle within the whole boundary layer was observed to be $30^{\circ}$. Mean wind direction under other terrain conditions also increased logarithmically with height above 500 m with a trend of rougher exposures corresponding to lager veering angles. A number of empirical parameters for engineering applications were presented, including the speed adjustment factors, power exponents of speed profiles, and veering angle, etc. The objective of this study aims to provide useful information on boundary layer wind characteristics for wind-resistant design of high-rise structures in coastal areas.

Observations on Normal Body Temperatures in Differently Climate Conditions

  • Nguyen, My-Hang;Hiromi Tokura
    • Journal of Photoscience
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    • v.9 no.2
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    • pp.406-408
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    • 2002
  • In order to know the characteristics of circadian rhythms in core temperature in tropical inhabitants, we measured rectal temperatures every 10 min for 24 hrs in 6 Vietnamese, 20 - 22 yrs (5 males and I females) under natural conditions. Average light intensity was 16000 lx. Ambient temperatures ranged from 33 to 36 oC. These data obtained were compared with those in Japanese setters and the Polish inhabitants. The participants were sitting mostly during wakefulness and lying in bed during sleep. The results obtained are summarized as follows: I) The average maximum value was 37.7 oC, which was significantly higher than in the Japanese and Polish as well. 2) The average minimum value was 36.4 oC, which was also lower. 3) A range of oscillation was 1.3 oC, which was clearly greater than in the people living in the temperate areas. The higher maximum value of core temperature, which was actively regulated under warm temperature, seemed of adaptive significance in order to reduce water consumption. A greater rage of oscillation in tropical Vietnamese people might have ecological significance for efficient acclimatization in the environment with strong light intensity and high ambient temperature, suggesting that the setpoint of core temperature could show a greater range of oscillation.

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Comparative Performance of Three Tropical Turfgrasses Digitaria longiflora, Axonopus compressus and St. Augustinegrass under Simulated Shade Conditions

  • Chin, Siew-Wai
    • Weed & Turfgrass Science
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    • v.6 no.1
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    • pp.55-60
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    • 2017
  • Shade affects turf quality by reducing light for photosynthesis. The shade tolerance of the tropical grasses, Digitaria longiflora and Axonopus compressus were evaluated against Stenotaphrum secundatum (St. Augustinegrass). The grasses were established under shade structures that provide 0%, 50%, 75% or 90% shade level for 30 days. A suite of leaf traits, recorded from similar leaf developmental stage, displayed distinct responses to shade conditions. Leaf length, relative to control, increased in all three species as shade level increased. The mean leaf extension rate was lowest in St. Augustinegrass (80.42%) followed by A. compressus (84.62%) and D. longiflora (90.78%). The higher leaf extension rate in D. longiflora implied its poor shade tolerance. Specific leaf area (SLA) increased in all species with highest mean SLA increase in D. longiflora ($348.55cm^2mg^{-1}$)followed by A. compressus ($286.88cm^2mg^{-1}$) and St. Augustinegrass ($276.28cm^2mg^{-1}$). The highest SLA increase in D. longiflora suggested its lowest performance under shade. The percent green cover, as estimated by digital image analysis, was lowest in D. longiflora (53%) under 90% shade level compared to both species. The relative shade tolerance of the three turfgrasses could be ranked as St. Augustinegrass > A. compressus > D. longiflora.

Identification of Potential Crossbreeds of Mulberry Silkworm, Bombyx mori L. and Their Performance Under Tropical Stress

  • Seshagiri, SureVenkata;Naik, S. Sankar;Goel, Ajay Kumar;Raju, P.J.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.22 no.2
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    • pp.45-49
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    • 2011
  • The performance of five newly evolved cross breeds were evaluated across seasons to understand the genotype and environment interactions and their stability under fluctuating tropical environmental conditions along with control hybrids $PM{\times}CSR2$ and $APM1{\times}APS8$. The data was collected on eight economic traits namely fecundity, yield per 10,000 larvae by number, yield per 10,000 larvae by weight, survival rate, cocoon weight, cocoon shell weight, cocoon shell ratio and filament length. The data was subjected for Analysis of Variance (ANOVA) and relevant statistical methods. The performance data obtained was further subjected for multiple trait evaluation index method. The ranks were adjudicated based on the index values. The two hybrids viz., $MSO3{\times}APS45$ and $MSO1{\times}APS12$ performed well under diversified environmental conditions indicating their overall stability and superiority. These hybrids revealed highly significant (p < 0.01) improvement for the majority of the traits over the control hybrids.

Prevention of Diapause in Bivoltine Eggs of the Silkworm, Bombyx mori, L., through a Cross with the Race KS-10 as Male Parent

  • Mundkur, Rajendra;Murthy, Mallesha;Mahadevappa;Raghuraman, R.;Bongale, U.D.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.9 no.1
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    • pp.107-109
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    • 2004
  • The present investigation reports a phenomenon hitherto unknown in tropical sericulture, wherein dia-pause nature of bivoltine eggs is overcome through a cross with a non-diapausing race of silkworm, Bombyx mori, L. Eggs of bivoltine silkworm Bombyx mori, L. generally do not hatch under tropical conditions. To prevent diapause, they are subjected to acid treatment or low temperature hibernation scheduled. A race developed at KSSRDI is found to prevent the diapause nature of bivoltine eggs when crossed as male parent, without any acid treatment or hibernation schedule. This phenomenon is reported for the first time, being unique, opens up interesting area of research in silkworm genetics of commercial implications in the industry.

THE APPLICATION OF AUSTRALIAN TROPICAL PASTURE TECHNOLOGY TO ASIA AND THE PACIFIC - Review -

  • Ayres, J.F.
    • Asian-Australasian Journal of Animal Sciences
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    • v.6 no.2
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    • pp.169-186
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    • 1993
  • The grassland regions of Australia, the Pacific and Asia share common latitudes albeit in opposing hemispheres. However, the environmental and socio-cultural context of pasture development in the subtropical and tropical regions of Australia, the Pacific Islands and Asia differ greatly. Successful technology transfer for improved productivity of grazing livestock is beset by three broad challenges; technical, logistical and socio-cultural. The technical challenge of defining the grassland environment and adapting known technology to local conditions can be successfully addressed by local technicians supported by a reservoir of appropriate international expertise. Logistical difficulties that impede provision of infrastructure and continuity of support services are the responsibility of indigenous organizations. Socio-cultural factors are fundamentally pervasive. These challenges, though outwardly obvious, require careful consideration by both donors and recipients of pasture technology to ensure success with pasture development for viable grazing industries.

Phosphagen Kinases of Parasites: Unexplored Chemotherapeutic Targets

  • Jarilla, Blanca R.;Agatsuma, Takeshi
    • Parasites, Hosts and Diseases
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    • v.48 no.4
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    • pp.281-284
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    • 2010
  • Due to the possible emergence of resistance and safety concerns on certain treatments, development of new drugs against parasites is essential for the effective control and subsequent eradication of parasitic infections. Several drug targets have been identified which are either genes or proteins essential for the parasite survival and distinct from the hosts. These include the phosphagen kinases (PKs) which are enzymes that playa key role in maintenance of homeostasis in cells exhibiting high or variable rates of energy turnover by catalizing the reversible transfer of a phosphate between ATP and naturally occurring guanidine compounds. PKs have been identified in a number of important human and animal parasites and were also shown to be significant in survival and adaptation to stress conditions. The potential of parasite PKs as novel chemotherapeutic targets remains to be explored.