• Title/Summary/Keyword: Tropical conditions

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Effect of rearing season, host plants and their interaction on economical traits of tropical tasar silkworm, Antheraea mylitta Drury- an overview

  • Bhatia, Narendra Kumar;Yousuf, Mohammad
    • International Journal of Industrial Entomology and Biomaterials
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    • v.29 no.1
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    • pp.93-119
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    • 2014
  • Tropical tasar silkworm, Antheraea mylitta (Lepidoptera: Saturniidae) is a polyphagous silk producing forest silkworm of commercial importance in India. Forest dependent people rear its larvae on different forestry host plants twice or thrice in a year for small household income. Larvae of A. mylitta feeds on many forest tree species, but always show a great degree of selectivity as a function of its behavioural responses to physical structure and chemical features of the host plants. Cocoon crop of A. mylitta is influenced by heterogeneity of tasar food plants and climatic conditions of the habitat. The role of host plants, temperature, humidity, rainfall, photoperiod and climatic variables on the growth and development of insects have clearly been demonstrated. This article entails an in-depth analysis on ecological and nutritional aspects of A. mylitta, which may provide selective information to researcher and forest managers, who are particularly associated with livelihood improvement of the poor people in forested area through location specific forest insect industry.

In vitro culture of Cryptosporidium muris in a human stomach adenocarcinoma cell line

  • Choi, Min-Ho;Hong, Sung-Tae;Chai, Jong-Yil;Park, Woo-Yoon;Yu, Jae-Ran
    • Parasites, Hosts and Diseases
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    • v.42 no.1
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    • pp.27-34
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    • 2004
  • We investigated the optimal culture conditions for Cryptosporidium muris in a human stomach adenocarcinoma (AGS) cell line by determining the effects of medium pH and of selected supplements on the development of C. muris. The optimum pH of the culture medium required for the development of C. muris was determined to be 6.6. The number of parasites significantly increased during cultivation for 72 hr (p < 0.05) at this level. On the other hand, numbers decreased linearly after 24 hr of incubation at pH 7.5. When cultured in different concentrations of serum, C. muris in media containing 5% FBS induced 4-7 times more parasites than in 1% or 10% serum. Of the six medium supplements examined, only 1 mM pyruvate enhanced the number of C. muris in vitro. Transmission electron microscopic observation showed the developmental stages of C. muris in the cytoplasm of the cells, not in an extracytoplasmic location. The growth of C. muris in AGS cells provides a means of investigating its biological characteristics and of testing its response to therapeutic agents. However, a more optimized culture system is needed for the recovery of oocysts on a large scale in vitro.

A coupled model simulation of the Last Glacial Maximum

  • Kim, Seong-Jung
    • Proceedings of the Korean Quaternary Association Conference
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    • 2004.11a
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    • pp.37-43
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    • 2004
  • The response of the CCCma coupled climate model to the imposition of LGM conditions is investigated. The global mean SAT and SST decrease by about $10^{\circ}C$ and $5.6^{\circ}C$ in the coupled model. Tropical SST decreases by $6.5^{\circ}C$, whereas CLIMAP reconstructions suggest that the tropics cool by only about $1.7^{\circ}C$, although the larger tropical cooling is consistent with the more recent proxy estimates. With the incorporation of a full ocean component, the coupled model gives a realistic spatial SST pattern, capturing features associated with ocean dynamics that are seen in the CLIMAP reconstructions. The larger decrease of the surface temperature in the model is associated with a reduction in global precipitation rate (about 15%). The tropical Pacific warm pool retreats to the west and a mean La $Ni\tilde{n}a$-like response is simulated with less precipitation over the central Pacific and more in the western tropical Pacific. The more arid ocean climate in the LGM results in an increase in SSS almost everywhere. This is particularly the case in the Arctic Ocean where large SSS increase is due to a decrease in river discharge to the Arctic Ocean associated with the accumulation of snow over the ice sheet, but in the North Atlantic by contrast SSS decreases markedly. This remarkable reduction of SSS in the North Atlantic is attributed to an increase in fresh water supply by an increase in discharges from the Mississippi and Amazon rivers and an increase in P-E over the North Atlantic ocean itself. The discharges increase in association with the wetter LGM climate south of the Laurentide ice sheet and in South America. The fresh water capping of the northern North Atlantic results in a marked reduction of deep convection and consequently a marked weakening of the North Atlantic overturning circulation. In the LGM, the maximum overturning stream function associated with the NADW formation decreases by about 60% relative to the control run, while in the Southern Ocean, oceanic convection is stronger in the LGM due to reduced stratification associated with an increase in SSS and a decrease in SST and the overturning stream function associated with the formation of AABW and the outflow increases substantially.

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Exploratory Research : Home Aquaponics of Tropical Fish Using IoT (IoT를 활용한 가정용 열대어 아쿠아포닉스에 관한 탐색적 연구)

  • Kim, Gyeong-Hyeon;Han, Dong-Wook
    • The Journal of the Korea Contents Association
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    • v.21 no.4
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    • pp.424-433
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    • 2021
  • The aim of this study is to explores the possibility of applying new aquaponics using guppies, a tropical fish breeding as companion fish at home, different from the aquaponics system using fish species such as loach, carp, and catfish for commercial purposes. To facilitate the application of Aquaponics at home, a system was established by connecting a water tank, water plants, hydroponic pots, plant growth LEDs, and Arduino sensors using Internet of Things(IoT) technology. As a hydroponic crops, lettuce that can be easily obtained and consumed at home was selected. In order to confirm the applicability of aquaponics using tropical fish, the growth rates of hydroponic crops in the same environment were compared as a control. The growth rate of aquaponics crops using tropical fish was about 77.4% of that of hydroponic crops. This will produce the same effect as hydroponic cultivation if conditions correspond with enough fish quantity to feed plant and appropriate pH control for growth are met. It can be seen that, and in the future, it can be used to develop an Aquaphonics standard system applicable at home.

Studies on the Cackroach Distribution from the House in Seoul City Area (서울시내(市內) 가주성(家住性) "바퀴"의 분포(分布)에 관(關)한 조사(調査))

  • Cha, C.W.;Ham, K.S.;Ahn, S.K.;Park, D.W.;Koo, S.H.;Han, Y.I.
    • Journal of Preventive Medicine and Public Health
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    • v.2 no.1
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    • pp.77-80
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    • 1969
  • In the cities nowadays, the dwelling conditions of Cackroach are provided by use of various kinds of construction material, installation of heating and cooling facilities that maintain moderate temperature, filthy sanitation, and lack of knowledge about insect as mechanical Vector. Cakroach is infectious disease Vector, and it proves to be of much importance in the public health. Considering such importance, the author has surveyed the distribution of Cackroach in the housing areas of Seoul City from May 1969 to the end of August 1969, and has come to the following conclusion: 1. House dwelling Cackroach collected in the City of Seoul are of two species, i. e. Blatella Germanica Linneaus and Periplaneta Japonica Karny. 2. Most of cackroach collected in Seoul are Blatella Germanica Linneaus and they are distributed in whole area of Seoul while that of Periplaneta Japonica Karny is distributed only in the limited area. 3. Dwelling places of Blatella Germanica Lineaus are in grog shop, Korean food restaurants, bakery shops, and patient rooms in hospitals. Many of them are found in tile kitchens and dining rooms of restaurants, and tearooms. They live in groups at older houses with much crack, warm and humid places. 4. For method of collection, the hand collection was the most effective. In trap collection during the day time, when the trap is placed at the narrow corners off the ground after confirming the dwelling places of cackroach, the match trap was more effective than the flask trap in collecting. In case of collecting during the night time, the flask trap was much more effective method than the match trap.

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Studies on the High Temperature Induced Stress on the Biochemical Profile and Fecundity of Daba and Laria Ecoraces of Tropical Tasar Silkworm Antheraea mylitta Drury (Lepidoptera: Saturniidae)

  • Lokesh, G.;Kar, P.K.;Srivastava, A.K.;Swaroopa, Saloni;Sinha, M.K.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.24 no.2
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    • pp.69-74
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    • 2012
  • Tropical tasar silkworm Antheraea mylitta Drury experiences extreme temperature stress conditions during its life cycle particularly during diapauses and first crop. The present study witnessed the impact of high temperature on some biochemical profiles and egg production (fecundity) of semi-domesticated Daba and Shorea robusta (Sal) based wild ecorace Laria during seed cocoon (pupa) preservation. Cocoons of Daba and Laria were treated with high temperature at $40^{\circ}C$ for 10 days in a BOD incubator. The protein profile and carbohydrate content in the hemolymph and fat body and total haemocyte count (THC) in the hemolymph of pupa were investigated. Further, the fecundity and fertility of egg was assessed. Significant increase in the protein concentration was observed in the hemolymph with reduction in the fat body (p<0.05). The difference in protein concentration was highly significant between the semidomesticated Daba and wild ecorace Laria (p<0.05). High pupal mortality (20%) and reduced fecundity (10-15%) in Daba was noticed compared to wild Laria. Also an increased THC (>28000) was recorded in Laria. The study infers the potentials of wild ecoraces in sustaining the extreme temperature conditions and need of adopting suitable package of practices for the preservation of diapause seed cocoons during extreme summer conditions. There is possibility to introgression thermal stress resistant traits in the semi-domesticated races of tasar silkworm by resorting to conventional breeding plans with wild races and keeping the thermal stress induced response as markers.

Influence of fly ash and GGBFS on the pH value of cement mortar in different curing conditions

  • Shafigh, Payam;Yousuf, Sumra;Ibrahim, Zainah;Alsubari, Belal;Asadi, Iman
    • Advances in concrete construction
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    • v.11 no.5
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    • pp.419-428
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    • 2021
  • The pH of cement-based materials (CBMs) is an important factor for their durability, sustainability, and long service life. Currently, the use of supplementary cementitious materials (SCMs) is becoming mandatory due to economic, environmental, and sustainable issues. There is a decreasing trend in pH of CBMs due to incorporation of SCMs. The determination of numerical values of pH is very important for various low and high volume SCMs blended cement mortars for the better understanding of different defects and durability issues during their service life. In addition, the effect of cement hydration and pozzolanic reaction of SCMs on the pH should be determined at initial and later ages. In this study, the effect of low and high-volume fly ash (FA) and ground granulated ballast furnace slag (GGBFS) cement mortars in different curing conditions on their pH values has been determined. Thermal gravimetric analysis (TGA) was carried out to support the findings from pH measurements. In addition, thermal conductivity (k-value) and strength activity indices of these cement mortars were discussed. The results showed that pH values of all blended cement mortars were less than ordinary Portland cement (OPC) mortar in all curing conditions used. There was a decreasing tendency in pH of all mortars with passage of time. In addition, the pH of cement mortars was not only dependent on the quantity of Ca(OH)2. The effect of adding SCMs on the pH value of cement mortar should be monitored and measured for both short and long terms.

A Study on the Safe Operations of Ships under Heavy Weather Conditions in the North Pacific(I) (북태평양의 악기상조건과 선박의 안전운항에 관한 연구(I))

  • 민병언
    • Journal of the Korean Institute of Navigation
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    • v.11 no.1
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    • pp.107-144
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    • 1987
  • In cold season, ice accretion on ship, drift ice, NW winter monsoon, developed extratropical cyclones and associated cold fronts, in warm season, tropical cyclones and dense sea fogs, are encountered very frequently in the North Pacific, especially in the northwest part of it. The two areas, namely, the northwest part of the North Pacific and Burmuda Triangle in the North Atlantic are generally known as most dangerous areas in the world because its high incidence of sea cascualities. In recent years, the small fisherboats operating in the northern seas were frequently sunk in a group as they encountered ice accretion or drift ice. And ocean going vessels were also sunk frequently due to strong winds and very high seas in winter monsoon or developed cyclones and cold fronts. The purpose of this paper is to analyze the real state of heavy weather conditions such as ice accretion on ship drift, ice, typhoons and sea fogs, and also to analyse the effect of these heavy weather phenomena on the vessels at sea, thus helping mariners operate in such heavy weather conditions.

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Shrinkages of Prefrozen or Presteamed Wood (전처리(前處理) 목재(木材)의 수축율(收縮率) 변화(變化))

  • Kang, Ho-Yang
    • Journal of the Korean Wood Science and Technology
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    • v.22 no.1
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    • pp.66-71
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    • 1994
  • To increase drying rate and reduce drying degradation, pretreatments such as prefreezing and presteaming have been widely used in wood industries. Presteaming lumbers prior to kiln drying is known positively to improve its permeability, to increase diffusion coefficient and to reduce discoloration, but negatively to increase collapse. Prefreezing lumbers prior to kiln drying is also known to reduce significantly its drying defects and its shrinkages. Thus it is no doubt that the pretreated lumbers shrink diversely from the untreated. In this study the shrinkage behaviors of the pretreated specimens are investigated by drying two tropical hardwoods (Apitong and Taun) in three different dying conditions: high temperature and slow drying rate (drying in a closed cylinder), high temperature and rapid drying rate (drying in an oven) and low temperature and slow drying rate(drying at room temperature). The prefrozen specimens show the least volumetric shrinkages in most drying conditions. The specimens dried in cylinders shrink most among all drying conditions. In general the pretreated specimens reached the 30 % moisture content faster than the untreated by about 30 %.

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On the Breeding of Dumbbell Bivoltine Silkworm Breeds of Bombyx mori L. Tolerant to High Temperature and High Humidity Conditions of the Tropics

  • Singh, Harjeet;Kumar, Nair Suresh
    • International Journal of Industrial Entomology and Biomaterials
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    • v.20 no.2
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    • pp.45-59
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    • 2010
  • It is well established fact that under tropical condition, unlike polyvoltines, bivoltines are more vulnerable to various stresses i.e. hot climatic conditions of tropics, poor leaf quality and improper management during summer which are not conducive for bivoltine rearing. Therefore, attempt has been made in this study to develop promising bivoltine breeds tolerant to high temperature and high humidity conditions of the tropics. In the present study, by utilizing temperature tolerant breeds six breeding lines were made and at every generation the 5th instar larvae were exposed to high temperature and high humidity and the survived ones were back crossed with the breeds moderately tolerant to diseases were made to improve the quantitative traits. From F6 generations, alternate rearing in normal temperature and high temperature were conducted. At the end of F12 generation, it was possible to isolate three dumbbell breeds viz., HH8, HH10 and HH12 with improvement in quantitative traits. The methodologies followed for the development are discussed.