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Subtropical Areas (subtropical + area)
Selected AbstractsConserving the Richmond Birdwing Butterfly over two decades: Where to next?ECOLOGICAL MANAGEMENT & RESTORATION, Issue 1 2008Don Sands Summary The Richmond Birdwing Butterfly, restricted to subtropical areas of Australia, is threatened with extinction in the Queensland part of its range because of clearing and fragmenting rainforests containing its larval food vines. Habitat fragmentation and drought have exacerbated risks of inbreeding depression and a range of other threats exist, including invasions of the exotic Dutchmans Pipe Vine which is toxic to Richmond Birdwing larvae. This article outlines the Richmond Birdwing Butterfly project from its beginnings in the Double Helix Club project and recently the Richmond Birdwing Recovery Network. It provides details of the biology of the butterfy and its food vines, as well as discussing elements for consideration in a future recovery plan including (i) protecting the remaining breeding sites; and, for the shorter term (ii) continuing to propagate and plant food plants at appropriate localities that previously supported the butterfly. [source] The role of macroinvertebrates and fish in regulating the provision by macrophytes of refugia for zooplankton in a warm temperate shallow lakeFRESHWATER BIOLOGY, Issue 10 2010MARÍA de los ÁNGELES GONZÁLEZ SAGRARIO Summary 1.,The zooplankton often undergoes diel horizontal migration (DHM) from the open water to the littoral of shallow lakes, thus avoiding predators in the former. This behaviour has functional impacts within the lake, as it enhances zooplankton survival, increases their control of phytoplankton and tends to stabilise the clear water state. However, most of the evidence supporting this migration pattern comes from cold north temperate lakes, and more evidence from tropical and subtropical areas, as well as from southern temperate areas, is needed. 2.,We conducted a field study of the diel horizontal and vertical migration of zooplankton, and the horizontal distribution of potential predatory macroinvertebrates and fish, over two consecutive days in the summer in a temperate lake in the southern hemisphere. We took zooplankton samples at two depths, at three sampling stations (inside beds of aquatic macrophytes, at their edge and in open water) along three transects running from the centre of a bed of Ceratophyllum demersum to open water. At each sampling station, we also took samples of macroinvertebrates and fish and measured physical and chemical environmental variables. 3.,Zooplankton (pelagic cladocerans, calanoid copepods and rotifers) avoided the shore, probably because of the greater risk from predators there. Larger and more vulnerable cladocerans, such as Diaphanosoma brachyurum and Moina micrura, were two to four times more abundant in open water than at the edge of or inside beds of macrophytes, respectively, by both day and night. Less vulnerable zooplankton [i.e. of medium body size (Ceriodaphnia dubia) or with the ability to swim fast (calanoid copepods)] were distributed evenly between open water and the edge of the plant beds. Small zooplankton, Bosmina huaronensis and pelagic rotifers, showed an even distribution among the three sampling stations. Accordingly, no DHM of zooplankton occurred, although larger organisms migrated vertically inside C. demersum stands. 4.,Macrophytes contained high densities of predatory macroinvertebrates and fish. The predator assemblage, composed of large-bodied macroinvertebrates (including odonates and shrimps) and small littoral fish, was permanently associated with submerged macrophytes. None of these groups moved outside the plant beds or changed their population structure (fish) over the diel cycle. 5.,Submerged macrophyte beds do not represent a refuge for zooplankton in lakes where predators are numerous among the plants, implying a weaker top-down control of phytoplankton biomass by zooplankton and, consequently, a more turbid lake. The effectiveness of macrophytes as a refuge for zooplankton depends on the associated assemblage of predatory macroinvertebrates and fish among the plants. [source] New media for the semiselective isolation and enumeration of Xanthomonas campestris pv. mangiferaeindicae, the causal agent of mango bacterial black spotJOURNAL OF APPLIED MICROBIOLOGY, Issue 4 2005O. Pruvost Abstract Aims:, Mango bacterial black spot, caused by Xanthomonas campestris pv. mangiferaeindicae, is a potentially severe disease in several tropical and subtropical areas. Data describing the life cycle of the pathogen are needed for improving integrated pest management strategies. Because of the important bacterial microflora associated with mango leaves, isolation of the pathogen is often difficult using nonselective agar media. Methods and Results:, A previously developed medium, BVGA, failed to inhibit several Gram-negative saprophytic bacteria, especially those belonging to Enterobacteriaceae. Two new semiselective media were developed. The selectivity of KC and NCTM3 media was achieved using cephalexin 40 mg l,1, kasugamycin 20 mg l,1 and neomycin 1 mg l,1, cephalexin 100 mg l,1, trimethoprime 5 mg l,1, pivmecillinam 100 mg l,1 respectively. Plating efficiencies ranged from 76 to 104% and from 78 to 132% for KC and NCTM3 respectively. Conclusions:, The new media allowed the growth of X. campestris pv. mangiferaeindicae whatever its country of isolation. The pathogen was repeatedly isolated with these media from asymptomatic leaves sampled in growth chamber experiments. Significance and Impact of the Study:, This work provides a description of new semiselective media, which should be valuable tools to study the ecology and epidemiology of X. campestris pv. mangiferaeindicae. [source] Richness and diversity of helminth communities in tropical freshwater fishes: empirical evidenceJOURNAL OF BIOGEOGRAPHY, Issue 4 2000Anindo Choudhury Abstract Aim Published information on the richness and diversity of helminth parasite communities in tropical freshwater fishes is reviewed in response to expectations of species-rich parasite communities in tropical regions. Location Areas covered include the tropics and some subtropical areas. In addition, the north temperate area of the nearctic zone is included for comparison. Methods Data from 159 communities in 118 species of tropical freshwater fish, summarized from 46 published studies, were used for this review. Parasite community descriptors used in the analyses included component community richness and calculated mean species richness. Data from 130 communities in 47 species of nearctic north temperate freshwater fish were summarized from 31 studies and used for comparison. Results The component helminth communities of many tropical freshwater fish are species-poor, and considerable proportions of fish from certain parts of the tropics, e.g. West African drainages, are uninfected or lightly infected. Mean helminth species richness was low and equaled or exceeded 2.0 in only 22 of 114 communities. No single group of helminths was identified as a dominant component of the fauna and species composition was variable among and within broader geographical areas. The richest enteric helminth assemblages were found in mochokid and clariid catfish with a mixed carnivorous diet, whereas algal feeders, herbivores and detritivores generally had species-poor gut helminth communities. Comparisons indicated that certain areas in the north temperate region had higher helminth species richness in fishes than areas in the tropics. Main conclusions Expectations of high species richness in helminth communities of tropical freshwater fishes are not fulfilled by the data. Direct comparisons of infracommunities and component communities in host species across widely separated phylogenetic and geographical lines are inappropriate. Examination of latitudinal differences in richness of monophyletic parasite groups or of compound communities may uncover patterns different from those found in this study. Richness of helminth communities may be ultimately determined not by the number of host species present but by the degree of divergence of host lineages and by their diversification modes. A phylogenetic framework for hosts and parasites will reveal if increased host species richness within host clades, when host speciation is accompanied by habitat or diet specialization, or both, leads to lower helminth diversity in host species by fragmentation of a core helminth fauna characteristic or specific of the larger host clade. This pattern may be analysed in the context of cospeciation and acquisition from other unrelated hosts (host-sharing or host-switching). [source] A Dengue Outbreak among Camp Participants in a Caribbean Island, 1995JOURNAL OF TRAVEL MEDICINE, Issue 2 2000Rob Lyerla Background: Dengue, a mosquito-transmitted viral disease, is a risk for visitors in tropical and subtropical areas. Several participants in a community-assistance program in Tortola, British Virgin Islands, in August, 1995, reported dengue-like symptoms either before or soon after leaving the island. Methods: We conducted a retrospective cohort study to determine the extent of the outbreak, risk factors for illness, and the proportion of inapparent infections. Program participants were interviewed by telephone or mail, and asked to submit a serum sample for dengue diagnosis. A clinically-diagnosed case of dengue was defined as a person with fever and two or more of the following: headache, retro-orbital pain, myalgia, arthralgia, rash, or hemorrhagic manifestations. Serum specimens were tested for virus isolation, polymerase chain reaction (PCR), plaque-reduction neutralization (PRNT) or anti-dengue IgM and IgG antibody. Results: Thirty-two (97%) of the 33 program participants responded; 21 of the 32 (66%) provided at least one serum sample for study. The median age was 17 years; 20 (62%) were women. Of 32 respondents, 22 (69%) met the clinical case definition for dengue: 15 of them (68%) had a positive IgM antibody response and 7 did not submit a serum sample. Dengue 1 virus (DEN-1) was identified by PCR in one case and all 11 positive PRNT results. No asymptomatic infections were identified. No respondent used effective mosquito repellent, and only 2 (6%) used bednets. Conclusion: A DEN-1 outbreak with a high attack rate (69%) occurred in a group of young short-term community aid workers. There were no asymptomatic infections documented. Participants' rare use of bednets or effective mosquito repellent highlights the importance of providing travelers to tropical areas with information about dengue fever and the recommended precautions to protect against infection. [source] Antigen selection for future anti- Trichuris vaccines: a comparison of cytokine and antibody responses to larval and adult antigen in a primary infectionPARASITE IMMUNOLOGY, Issue 9 2008H. DIXON SUMMARY Trichuriasis, caused by the whipworm Trichuris trichiura, is endemic in tropical and subtropical areas, affecting approximately 1 billion people. Child anthelminthic treatment programmes are being implemented but repeated treatments are costly, may prevent the development of acquired immunity and can lead to the development of drug resistant parasites. Thus, the development of a vaccine which would lead to the acquisition of immunity at an earlier age and reduce community faecal egg output would be beneficial. Development of subunit vaccines requires the identification of protective antigens and their formulation in a suitable adjuvant. Trichuris muris is an antigenically similar laboratory model for T. trichiura. Subcutaneous vaccination with adult excretory,secretory products (ES) protects susceptible mouse strains from T. muris. Larval stages may contain novel and more relevant antigens which when incorporated in a vaccine induce worm expulsion earlier in infection than the adult worm products. This study finds negligible difference in the cellular and humoral immune response to T. muris adult and third stage larva(e) (L3) ES during a primary T. muris infection, but identifies high molecular weight proteins in both adult and L3 ES as potential vaccine candidates. [source] Photoperiod and temperature affect the life cycle of a subtropical cockroach, Opisoplatia orientalis: seasonal pattern shaped by winter mortalityPHYSIOLOGICAL ENTOMOLOGY, Issue 1 2004Dao-Hong Zhu Abstract.,Opisoplatia orientalis is an ovoviviparous cockroach living in the subtropical areas in Japan. Both adults and nymphs overwinter on Hachijo Island (33°N). The nymphs sampled before and after overwintering showed a similar pattern in frequency distribution of head widths with a definite peak of fifth instars. The present study was conducted to determine how this pattern was formed by investigating the effects of photoperiod and temperature on development and reproduction. Photoperiod influenced the number of nymphal instars, resulting in a longer duration of nymphal development at LD 12 : 12 h than at LD 16 : 8 h. However, the rate of development at each instar was only affected to a small extent by photoperiod and no sign of diapause was detected. It was suggested that the photoperiodic response controlling the number of nymphal instars might have evolved to adjust the timing of adult emergence and reproduction to the favourable season. The prereproductive period and time intervals between nymph depositions were prolonged as temperature declined, but there was no evidence for diapause in adults. Mortality occurred in eggs and embryos inside of the body of the females during winter. Thus, it was inferred that female adults would reset ovarian development in spring and deposit nymphs in summer simultaneously, and these nymphs would reach the fifth instar before winter comes. This winter mortality hypothesis was supported by experiments in which reproductive activity and mortality were monitored for field-collected adults under either constant or changing temperature conditions simulating those in the field. [source] The development of artemisinin resistance in malaria: reasons and solutionsPHYTOTHERAPY RESEARCH, Issue 7 2010Cosima Chrubasik Abstract Despite world-wide efforts in fighting malaria, this mosquito-borne infectious disease is a huge burden for the population, especially in tropical and subtropical areas. The WHO recommends artemisinin-based combination therapy for the treatment of uncomplicated Plasmodium falciparum malaria. However, artemisinin resistance cannot now be ignored. Factors affecting the development of artemisinin resistance include uncontrolled use of artemisinin-based combination therapy (ACT), mobile populations and migrants, artemisinin monotherapy, the use of subtherapeutic levels of artesiminin, substandard and counterfeit drugs, high treatment cost, and co-use of artemisinin derivates as prophylactic agents. Promising herbal alternatives are already in the pipeline, but the only long-term solution for eradicating malaria would be the development of a successful vaccination. Copyright © 2010 John Wiley & Sons, Ltd. [source] Sources of water vapour contributing to the Elbe flood in August 2002,A tagging study in a mesoscale modelTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 638 2009H. Sodemann Abstract In this study we investigate the contribution of various moisture sources to the Elbe flood that occurred in Central Europe during August 2002. An 8-day simulation with the mesoscale numerical weather prediction model CHRM, including newly implemented water vapour tracers, has been performed. According to the simulation, rather than drawing moisture from one single dominant source region, water vapour from widely separated moisture sources contributed to the extreme precipitation in the most affected area, notably at distinct, subsequent periods of time, and each in significant amounts. These moisture sources include the Atlantic and Mediterranean ocean areas inside the model domain, evapotranspiration from land areas, and long-range advection from subtropical areas outside the model domain. The results highlight the importance of the concurrent upper-level circulation and the mesoscale flow structures associated with the cyclone for producing extreme precipitation in parts of Germany, Austria, and the Czech Republic during that period. Furthermore, the numerical and technical problems of implementing water vapour tracers into a limited-area model are discussed, including conservative tracer advection, initialization, boundary treatment, and the handling of precipitation parametrizations. An evaluation of the consistency of the method in terms of water vapour, cloud water, and precipitation is provided, with generally satisfying results. The model with its detailed water vapour tracer implementation can now be used for further case-studies and climatological simulations, and serve as a reference for evaluating the performance of other moisture tracking methods, such as those based on backward trajectories. Copyright © 2009 Royal Meteorological Society [source] Precocious sex change and spermatogenesis in the underyearling Malabar grouper Epinephelus malabaricus by androgen treatmentAQUACULTURE RESEARCH, Issue 2 2010Ryosuke Murata Abstract The Malabar grouper Epinephelus malabaricus is an important candidate species for commercial aquaculture in tropical and subtropical areas. In nature, this species requires more than 10 years to change sex from female to male and have active spermatogenic tissues in the testis. Thus, it is essential to find a means of producing sperm for seed production. This is the first report of artificial sex change in underyearling E. malabaricus. Female E. malabaricus with immature ovaries at 144 days post-hatch (DPH) were fed a diet with 17,-methyltestosterone (MT) at 50 ,g g,1 diet for 6 months. Sex change occurred in most of the treated fish, which had testis with all stages of spermatogenic germ cells including spermatozoa. In contrast, most of the control fish had immature ovaries. These results, which reveal that germ cells in the underyearling grouper have the ability to produce spermatozoa in response to exogenous androgen, demonstrate that sex change can be artificially induced during ovarian development. [source] Cold tolerance of the banana prawn Penaeus merguiensis de Man and its growth at different temperaturesAQUACULTURE RESEARCH, Issue 1 2002Tung Hoang Abstract Critical thermal minima (CTMin) were determined for subadults of Penaeus merguiensis acclimated at 15, 18, 21 and 24 °C for 3 weeks. The effect of cooling rate on CTMin was also investigated. The CTMin of prawns from these respective acclimation groups were 5.3, 6.0, 7.4, 9.0 and 4.7, 5.4, 6.0, 7.3 °C at the cooling rate of 1 °C h,1 and 3 °C h,1 respectively. Both acclimation temperature and cooling rate had a significant effect (P < 0.01) on the CTMin. Observation during the acclimation period showed that the growth rate of prawns acclimated at 24 °C was much higher than those acclimated at 21, 18 and 15 °C. The results indicate that P. merguiensis can overwinter in aquaculture ponds in south-east Queensland, Australia, or other subtropical areas and attain good growth if simple overwintering facilities are available. [source] Four new species of the myrmecophile Diplocotes Westwood (Coleoptera: Ptinidae) from Queensland and South AustraliaAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 2 2008Karen L Bell Abstract, Four new species of the Australian ptinid genus Diplocotes are described. Two of these species are from the dry tropical and subtropical areas of northern and central Queensland, while the other two are from the arid areas of South Australia. While the four new species described here have not been observed with ants in the field, the species of this genus are known to be myrmecophilous, and similar interactions may occur between the new species and their host ants. Additionally, many characters are shared with other unrelated myrmecophilous species, and may be convergent adaptations to the ant-associated lifestyle. [source] Potential distribution of the Asian disease vector Culex gelidus Theobald (Diptera: Culicidae) in Australia and New Zealand: a prediction based on climate suitabilityAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 4 2005Craig R Williams Abstract,Culex gelidus has a wide distribution throughout Asia, where it is a vector of Japanese encephalitis. It was first detected in Australia in 1999, with archived material revealing an introduction sometime prior to 1994. It is currently widely distributed throughout northern and particularly north-eastern Australia. Using climate matching software (CLIMEX Version 1.1) and the known distribution of Cx. gelidus throughout Asia, a predicted distribution for Australasia based on current climate was developed. A potentially wide distribution throughout coastal Australia, particularly in tropical and subtropical areas, was revealed. Few inland locations were suitable, except in tropical areas of the Northern Territory and Queensland. The predicted distribution presented here is concordant with most recent collection records of Cx. gelidus in Australasia. However, there are a small number of exceptions which highlight some of the limitations of this approach for predicting mosquito distributions. The presence of Cx. gelidus in a large artificial swamp in Alice Springs is one such example. The predicted Cx. gelidus distribution incorporates highly populated areas, in which people may experience an increased risk of mosquito-borne viral encephalitis should this mosquito spread throughout its entire predicted range. [source] A preliminary X-ray study of d,d -heptose-1,7-bisphosphate phosphatase from Burkholderia thailandensis E264ACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 2 2010Mi-Sun Kim d,d -Heptose-1,7-bisphosphate phosphatase (GmhB), which is involved in the third step of the NDP-heptose biosynthesis pathway, converts d,d -heptose-1,7-bisphosphate to d,d -heptose-1-phosphate. This biosynthesis pathway is a target for new antibiotics or antibiotic adjuvants for Gram-negative pathogens. Burkholderia thailandensis is a useful surrogate organism for studying the pathogenicity of melioidosis owing to its extensive genomic similarity to B. pseudomallei. Melioidosis caused by B. pseudomallei is a serious invasive disease of animals and humans in tropical and subtropical areas. In this study, GmhB has been cloned, expressed, purified and crystallized. X-ray data have also been collected to 2.50,Å resolution using synchrotron radiation. The crystal belonged to space group P6, with unit-cell parameters a = 243.2, b = 243.2, c = 41.1,Å. [source] A preliminary X-ray study of sedoheptulose-7-phosphate isomerase from Burkholderia pseudomalleiACTA CRYSTALLOGRAPHICA SECTION F (ELECTRONIC), Issue 11 2009Mi-Sun Kim Sedoheptulose-7-phosphate isomerase (GmhA) converts d -sedoheptulose 7-phosphate to d,d -heptose 7-phosphate. This is the first step in the biosynthesis pathway of NDP-heptose, which is responsible for the pleiotropic phenotype. This biosynthesis pathway is the target of inhibitors to increase the membrane permeability of Gram-negative pathogens or of adjuvants working synergistically with known antibiotics. Burkholderia pseudomallei is the causative agent of melioidosis, a seriously invasive disease in animals and humans in tropical and subtropical areas. GmhA from B. pseudomallei is one of the targets of antibiotic adjuvants for melioidosis. In this study, GmhA has been cloned, expressed, purified and crystallized. Synchrotron X-ray data were also collected to 1.9,Å resolution. The crystal belonged to the primitive orthorhombic space group P212121, with unit-cell parameters a = 61.3, b = 84.2, c = 142.3,Å. A full structural determination is under way in order to provide insights into the structure,function relationships of this protein. [source] Emerging and poorly known viral inflammatory eye diseasesACTA OPHTHALMOLOGICA, Issue 2009M KHAIRALLAH Arthropod vector borne diseases are among the most important emergent infections. They include a wide variety of bacterial, viral, and parasitic diseases that are transmitted to humans by the bite of mosquito, tick, or other arthropod. Most of them are prevalent in tropical and subtropical areas, but they tend to spread into new regions mainly due to increasing temperatures worldwide, movement of people, increasing human population densities, wider dispersal of competent vectors, and transportation of goods and animals. Numerous arthropod vector borne diseases have been associated with uveitis. Among them, specific viral diseases recently emerged as important causes of uveitis in the developing and developed world. They include West Nile virus (WNV) infection, Rift Valley fever (RVF) , dengue fever (DF), and Chikungunya. These viral diseases have been recently associated with an array of ocular manifestations, including anterior uveitis, retinitis, chorioretinitis, retinal vaculitis, and optic nerve involvement. Proper clinical diagnosis of any of these infectious diseases is based on epidemiological data, history, systemic symptoms and signs, and the pattern of uveitis. The diagnosis is usually confirmed by detection of specific antibody in serum. A systematic ocular examination, showing fairly typical findings, can help establish an early clinical diagnosis of a specific systemic viral infection while serologic testing is pending. Prevention remains the mainstay for control of arthropod vector borne viral diseases. [source] Nutritional Value of Cassava for Use as a Staple Food and Recent Advances for ImprovementCOMPREHENSIVE REVIEWS IN FOOD SCIENCE AND FOOD SAFETY, Issue 3 2009Julie A. Montagnac ABSTRACT:, Cassava is a drought-tolerant, staple food crop grown in tropical and subtropical areas where many people are afflicted with undernutrition, making it a potentially valuable food source for developing countries. Cassava roots are a good source of energy while the leaves provide protein, vitamins, and minerals. However, cassava roots and leaves are deficient in sulfur-containing amino acids (methionine and cysteine) and some nutrients are not optimally distributed within the plant. Cassava also contains antinutrients that can have either positive or adverse effects on health depending upon the amount ingested. Although some of these compounds act as antioxidants and anticarcinogens, they can interfere with nutrient absorption and utilization and may have toxic side effects. Efforts to add nutritional value to cassava (biofortification) by increasing the contents of protein, minerals, starch, and ,-carotene are underway. The transfer of a 284 bp synthetic gene coding for a storage protein rich in essential amino acids and the crossbreeding of wild-type cassava varieties with Manihot dichotoma or Manihot oligantha have shown promising results regarding cassava protein content. Enhancing ADP glucose pyrophosphorylase activity in cassava roots or adding amylase to cassava gruels increases cassava energy density. Moreover, carotenoid-rich yellow and orange cassava may be a foodstuff for delivering provitamin A to vitamin A,depleted populations. Researchers are currently investigating the effects of cassava processing techniques on carotenoid stability and isomerization, as well as the vitamin A value of different varieties of cassava. Biofortified cassava could alleviate some aspects of food insecurity in developing countries if widely adopted. [source] | |||||||||||||||||||||||||||||||