Geo-climatic Zones Research Articles

Scale dependence of the benefits and efficiency of green and cool roofs

Cool and green roofs are widely adopted measures for curtailing summertime urban heat islands. Existing numerical studies to assess their effectiveness and cooling benefits usually assume an unrealistic 100% coverage across the entire metropolis. This study investigates the scale dependence of the absolute cooling benefits and efficiency (cooling per adapted roof area) of cool and green roofs in a typical summer when they are installed over 25% of building rooftops at local, city, or regional scales. Six major U.S. cities with active climate action plans in different geoclimatic zones are compared through high-resolution simulations using the Weather Research and Forecasting model. The results reveal that reductions in 2-m air temperature over the urban core increase non-linearly with the intervention area, and the benefits of both roof types scale similarly. This scale-dependence of urban core cooling is not universal, but is rather controlled by the shape of metropolitan areas and wind pattern. The siting of mitigation measures hence plays an important role especially under windy conditions, and some urban cores are not able to achieve a noticeable and consistent cooling by retrofitting their own rooftops. Regional-scale deployments of mitigation strategies, on the other hand, yield a more substantial temperature reduction but with a lower efficiency. The scale-dependence of regional cooling efficiency showed remarkable similarity across studied cities, yielding a potentially generalizable power law. The successful resiliency plans for cities should account for the scale dependence and geoclimatic determinants of the achievable cooling, and identify the target neighborhoods of most interest.

Canine Monocytic Ehrlichiosis among working dogs of organised kennels in India: A comprehensive analyses of clinico-pathology, serological and molecular epidemiological approach

Canine Monocytic Ehrlichiosis (CME) is a serious tick-borne rickettsial disease affecting canine populations globally. Besides few reports from stray and pet dogs from localised geographical regions (cities/towns/small states), a comprehensive study on prevalence of Ehrlichia canis (E. canis) among working dogs from different geo-climatic zones of India was pertinently lacking. Study of CME among these dog populations was thus carried out, encompassing clinical aspects and different diagnostic methodologies viz., microscopy, serology and molecular biology. During the two-year study period, clinical specimens from 225 cases suspected of canine ehrlichiosis were examined for clinical pathology and presence of the haemoparasites. Overall prevalence of ehrlichiosis by microscopic examination, commercial dot-ELISA kit and nested PCR assay was estimated to be 1.3%, 19.1% and 5.8%, respectively, which were found to be statistically significant by McNemar Chi squared test (p<0.05). It was also observed that possibly due to widespread use of doxycycline therapy in field, CME presently does not remain a potential threat which it uses to pose earlier. However, concurrent infections of E. canis and Babesia gibsoni were found to be mostly fatal. Keeping in view of high number of apparently healthy dogs (24) out of total positive cases (46) observed during the study, it is recommended that prevalence studies on CME should also involve screening of apparently healthy dogs. Phylogenetic analysis carried on partial sequencing of 16S rRNA of E. canis strains revealed that all of the Indian strains clustered in a single clade with other E. canis species from India and rest of the world. Molecular divergence was observed among the sequences of Brazilian and American isolates which were also included in the present study. These findings have thus opened a new paradigm for planning of pragmatic control strategies against CME.

Bovine fascioliasis risk factors and space-time clusters in Mymensingh, Bangladesh.

A hospital-based case-control study was undertaken to identify risk factors for - and space-time clusters of - bovine fascioliasis in Mymensingh, Bangladesh. Fascioliasis cases diagnosed using fecal sample test between January 2006 and December 2015 (n=593) at the Bangladesh Agricultural University Veterinary Teaching Hospital (BAUVTH) and three controls per case (n=1563) were selected. Data on date of report, location, age, breed, sex and body weight were extracted from the hospital records. A mixed multivariable logistic regression model with location as a random effect was built to identify risk factors for fascioliasis. The scan statistic (Bernoulli model) was used to identify space-time clusters. Compared to cattle ≤1year of age, the odds of fascioliasis were 5.2- (95% confidence interval [CI]: 3.6-7.4), 6.1- (95% CI: 4.2-8.7) and 10.7-times (95% CI: 6.9-16.6) greater in cattle aged >1-3, >3-8 and >8years, respectively. The odds of fascioliasis were 1.4- (95% CI: 1.03-1.99) and 1.5-times (95% CI: 1.13-2.11) greater in post-monsoon and monsoon seasons, respectively, compared to winter. Five significant (P<0.05) clusters (7-13 locations each) were identified, lasting from six months to 5years. Six locations - Bhangnamari, Deuhakhola, Gauripur, Ishwarganj, Nandail and Rasulpur - appeared to be at more risk for fascioliasis: these locations were part of at least 3 significant clusters. Anthelmintic treatment should focus on high risk age groups (>1year, especially those >8years). Importantly, we have demonstrated high-risk periods (monsoon and post-monsoon) and disease hotspots of bovine fascioliasis. Focusing disease control efforts in time and space offers an opportunity to more effectively control bovine fascioliasis in Bangladesh and in other similar geo-climatic zones throughout the world.

Fascioliasis risk factors and space-time clusters in domestic ruminants in Bangladesh

BackgroundA retrospective observational study was conducted to identify fascioliasis hotspots, clusters, potential risk factors and to map fascioliasis risk in domestic ruminants in Bangladesh. Cases of fascioliasis in cattle, buffalo, sheep and goats from all districts in Bangladesh between 2011 and 2013 were identified via secondary surveillance data from the Department of Livestock Services’ Epidemiology Unit. From each case report, date of report, species affected and district data were extracted. The total number of domestic ruminants in each district was used to calculate fascioliasis cases per ten thousand animals at risk per district, and this was used for cluster and hotspot analysis. Clustering was assessed with Moran’s spatial autocorrelation statistic, hotspots with the local indicator of spatial association (LISA) statistic and space-time clusters with the scan statistic (Poisson model). The association between district fascioliasis prevalence and climate (temperature, precipitation), elevation, land cover and water bodies was investigated using a spatial regression model.ResultsA total of 1,723,971 cases of fascioliasis were reported in the three-year study period in cattle (1,164,560), goats (424,314), buffalo (88,924) and sheep (46,173). A total of nine hotspots were identified; one of these persisted in each of the three years. Only two local clusters were found. Five space-time clusters located within 22 districts were also identified. Annual risk maps of fascioliasis cases correlated with the hotspots and clusters detected. Cultivated and managed (P < 0.001) and artificial surface (P = 0.04) land cover areas, and elevation (P = 0.003) were positively and negatively associated with fascioliasis in Bangladesh, respectively.ConclusionsResults indicate that due to land use characteristics some areas of Bangladesh are at greater risk of fascioliasis. The potential risk factors, hot spots and clusters identified in this study can be used to guide science-based treatment and control decisions for fascioliasis in Bangladesh and in other similar geo-climatic zones throughout the world.

Criteria and indicator approach of global sustainability assessment system for sustainable landscaping using native plants in Qatar

The present study focuses on the importance and need to identify criteria and indicators (C&I) for sustainable landscaping using native plants in Qatar. The conditions for operationalizing the criteria and indicators approach are being incorporated into sustainable development practices and management planning in Qatar. This paper aims to develop criteria and related indicators for strengthening the global sustainability assessment system (GSAS) in order to provide a holistic approach for sustainable environmental assessment and the enhancement of ecosystem services. A total of 50 potentially native plant species were prioritized and categorized based on the following different parameters: weather conditions tolerated (temperature, humidity, and rainfall), multiple use value (ecological, economical, and medicinal), standard crown size (≤50cm and ≥50cm) and water requirement (moist, moderate, and dry). Diverse local stakeholders as well as international experts were consulted to rank the plant species, and concluded that these prioritized native species are fit for sustainable landscaping as opposed to the exotic plant species which are imported from different geo-climatic zones. Environmental, social, economic, human, and policy sustainability aspects were considered, along with 12 criteria and 49 related indicators which were identified by promoting the use of potential native plants for sustainable landscaping in Qatar.

The basic reproduction quotient (Q0) as a potential spatial predictor of the seasonality of ovine haemonchosis.

Haemonchus contortus is a gastrointestinal nematode parasite of small ruminants, which feeds on blood and causes significant disease and production loss in sheep and goats, especially in warmer parts of the world. The life cycle includes free-living immature stages, which are subject to climatic influences on development, survival and availability, and this species therefore exhibits spatio-temporal heterogeneity in its infection pressure based on the prevailing climate. Models that better explain this heterogeneity could predict future epidemiological changes. The basic reproduction quotient (Q0) was used as a simple process-based model to predict climate-driven changes in the potential transmission of H. contortus across widely different geo-climatic zones, and showed good agreement with the observed frequency of this species in the gastrointestinal nematode fauna of sheep (r = 0.81, P &lt;0.01). Averaged monthly Q0 output was further used within a geographical information system (GIS) to produce preliminary haemonchosis risk maps for the United Kingdom (UK) over a four-year historical span and under future climate change scenarios. Prolonged transmission seasons throughout the UK are predicted, especially in the south although with restricted transmission in peak summer due to rainfall limitation. Additional predictive ability might be achieved if information such as host density and distribution, grazing pattern and edaphic conditions were included as risk layers in the GIS-based risk map. However, validation of such risk maps presents a significant challenge, with georeferenced observed data of sufficient spatial and temporal resolution rarely available and difficult to obtain.

Managing fertiliser nitrogen to reduce nitrous oxide emissions and emission intensities from a cultivated Cambisol in Scotland

Emissions of nitrous oxide (N2O) were measured from an arable site in south east Scotland for twelve months during 2011–2012 using an intensive sampling strategy. This fully replicated and blocked field experiment aimed to provide accurate measurements of N2O emissions from one of the UK's principle geoclimatic zones supporting agricultural production and to produce robust N2O emission factors (EFs). Calculated EFs were compared to the IPCC's default Tier 1 EF of 1.25%, and the new value of 1%, to assess their suitability for use in locations throughout the UK. Emissions from ten treatments fertilised with either ammonium nitrate or urea at rates of 0kgNha−1 to 200kgNha−1, and sown with spring barley, were measured using the static closed chamber technique. Potential N2O mitigation options were investigated; these included the use of a nitrification inhibitor (NI), split fertiliser applications and variations in the form and quantity of fertiliser applied. Crop yields were measured to enable calculation of N2O emission intensities for each treatment; this is an important factor to consider when assessing N2O mitigation options due to the need to maintain crop yields. Cumulative N2O emissions varied between 1.32kg N2O-Nha−1 and 3.82kg N2O-Nha−1 with a mean 42% decrease in emissions associated with the use of the NI. Increases in crop yield were associated with increases in N fertiliser application, and the amendment of treatments with a NI and the use of a split fertiliser application significantly decreased crop yields by approximately 10% and 5% respectively. Annual EFs ranged between −0.28% to 1.35%. Emission intensities decreased with increasing fertiliser application at low N application rates, and the optimum fertiliser application rate to obtain minimum emissions but maximum crop yield was 160kgNha−1.

Vegetation geo-climatic zonation in the rocky mountains, Northern Utah, USA

We developed a vegetation geo-climatic zonation incorporating the zonal concept, gradient and discriminant analysis in Wasatch Range, northern Utah, USA. Mountainous forest ecosystems were sampled and described by vegetation, physiographic features and soil properties. The Snowpack Telemetry and National Weather Service Cooperative Observer Program weather station networks were used to approximate the climate of sample plots. We analysed vegetation and environmental data using clustering, ordination, classification, and ANOVA techniques to reveal environmental gradients affecting a broad vegetation pattern and discriminate these gradients. The specific objective was to assess and classify the response of the complex vegetation to those environmental factors operating at a coarse-scale climatic level. Ordination revealed the dominant role of regional, altitude-based climate in the area. Based on vegetation physiognomy, represented by five tree species, climatic data and taxonomic classification of zonal soils, we identified two vegetation geo-climatic zones: (1) a montane zone, with Rocky Mountain juniper and Douglas-fir; and (2) a subalpine zone, with Engelmann spruce and subalpine fir as climatic climax species. Aspen was excluded from the zonation due to its great ecological amplitude. We found significant differences between the zones in regional climate and landform geomorphology/soils. Regional climate was represented by elevation, precipitation, and air and soil temperatures; and geomorphology by soil types. This coarse-scale vegetation geo-climatic zonation provides a framework for a comprehensive ecosystem survey, which is missing in the central Rocky Mountains of the United States. The vegetation-geo-climatic zonation represents a conceptual improvement on earlier classifications. This framework explicitly accounts for the influence of the physical environment on the distribution of vegetation within a complex landscape typical of the central Rocky Mountains and in mountain ranges elsewhere.

ECOENVELOPES R&amp;D. Passive architectural envelopes high thermal performance and low environmental impact for tropical geoclimatic zones

“Ecoenvelopes” is about the development of building envelope solutions for tropical humid climates involving passive control of thermal gains on their surfaces, allowing for better internal conditions and comfort without the use of thermal machines. Environmental principles, design, and technological aspects are specifically defined based on the peculiar conditions (geo-climatic, technological, of biodiversity, economic and anthropic) present in the Colombian low altitude regions, marked by constant high temperatures. Thermal and CFD simulations orient the process of experimental verification in a permanent laboratory counting on partnerships and available know-how.

Characterization of three novel isoprenyl diphosphate synthases from the terpenoid rich mango fruit

Mango (cv. Alphonso) is popular due to its highly attractive, terpenoid-rich flavor. Although Alphonso is clonally propagated, its fruit-flavor composition varies when plants are grown in different geo-climatic zones. Isoprenyl diphosphate synthases catalyze important branch-point reactions in terpenoid biosynthesis, providing precursors for common terpenoids such as volatile terpenes, sterols and carotenoids. Two geranyl diphosphate synthases and a farnesyl diphosphate synthase were isolated from Alphonso fruits, cloned for recombinant expression and found to produce the respective products. Although, one of the geranyl diphosphate synthases showed high sequence similarity to the geranylgeranyl diphosphate synthases, it did not exhibit geranylgeranyl diphosphate synthesizing activity. When modeled, this geranyl diphosphate synthase and farnesyl diphosphate synthase structures were found to be homologous with the reference structures, having all the catalytic side chains appropriately oriented. The optimum temperature for both the geranyl diphosphate synthases was 40 °C and that for farnesyl diphosphate synthase was 25 °C. This finding correlated well with the dominance of monoterpenes in comparison to sesquiterpenes in the fruits of Alphonso mango in which the mesocarp temperature is higher during ripening than development. The absence of activity of these enzymes with the divalent metal ion other than Mg(2+) indicated their adaptation to the Mg(2+) rich mesocarp. The typical expression pattern of these genes through the ripening stages of fruits from different cultivation localities depicting the highest transcript levels of these genes in the stage preceding the maximum terpene accumulation indicated the involvement of these genes in the biosynthesis of volatile terpenes.

Brief Report: Ultraviolet Radiation Exposure Is Associated With Clinical and Autoantibody Phenotypes in Juvenile Myositis

Genetic and environmental factors may contribute to the etiology of the juvenile idiopathic inflammatory myopathies (IIMs), which are systemic autoimmune diseases that are characterized by muscle and skin inflammation. We undertook this study to investigate the association between ultraviolet radiation (UVR) exposure and the clinical and autoantibody expression of juvenile IIM. The relationship between UVR exposure in the month before symptom onset and the prevalence of juvenile dermatomyositis (DM), compared to juvenile polymyositis (PM), was assessed in 298 juvenile IIM patients. Among the patients with juvenile DM, the association between UVR exposure and presence of myositis autoantibodies was assessed. Regression models were stratified by sex and race. The association between the regional UV index in US geoclimatic zones and the clinical and autoantibody subgroups was examined by weighted least squares regression analysis. Among girls in this population, the odds of having juvenile DM, compared to juvenile PM, increased per unit increase in the patients' highest UV index in the month before symptom onset (odds ratio [OR] 1.18, 95% confidence interval 1.00-1.40). Moreover, both the mean and highest UV indices were associated with increasing odds of having anti-p155/140 autoantibodies, with the strongest odds in white males (ORs of 1.30 and 1.23, respectively). No association was observed between the UV index and presence of anti-MJ autoantibodies or lack of any myositis autoantibodies. Across all 9 US geoclimatic regions, the mean UV index was associated with increasing odds of having juvenile DM and anti-p155/140 autoantibodies, but decreasing odds of having anti-MJ autoantibodies. Short-term UVR exposure prior to illness onset may have a role in the clinical and serologic expression of juvenile myositis. Further research examining the mechanisms of action of UVR in the pathogenesis of juvenile IIM is suggested from these findings.

Environmental Escherichia coli occur as natural plant growth-promoting soil bacterium

Currently, it is presumed that Escherichia coli is not a normal inhabitant of the soil. Soilborne E. coli strains were isolated from broad range of 7 geoclimatic zones of India, indicating that E. coli can survive and thrive under different extreme soil conditions. Diversity among E. coli strains from widely separated geographic regions using enterobacterial repetitive intergenic consensus (ERIC)-PCR did not reveal any relationships between the genotypes and the source of isolation. Inoculation of maize (Zea mays cv. Arkil) seeds with E. coli NBRIAR3 (NBRIAR3) significantly enhanced (P < 0.05) plant growth and nutrient uptake, when compared with uninoculated control. Presence or absence of NBRIAR3 did not affect significantly (P < 0.05) diversity indexes, using substrate utilization patterns on the Biolog Eco plates. Clone libraries based on 16S rRNA gene from rhizosphere of maize plants demonstrated rather similar phylotype diversity from the uninoculated control and NBRIAR3-treated rhizosphere soil, which further indicated that NBRIAR3 did not exert a major influence on the overall bacterial diversity. The methodological approach described in this study supports the idea that E. coli should be treated as native soil bacterium instead of as an "indicator" of the possible presence of other fecal coliform bacteria. The online version of this article (doi:10.1007/s00203-010-0544-1) contains supplementary material, which is available to authorized users.

The epidemiology of fasciolosis in ruminants in different geo-climatic regions of north India

Epidemiological studies were conducted on Fasciola giagntica infection in different geo-climatic zones (hills, tarai and plains) in six states of north India during January 2001 to December 2004. Prevalence rates of 10.79, 13.90, 2.78 and 2.35 percent were recorded in cattle, buffaloes, sheep and goats, respectively. Animals in the tarai had the highest prevalence of fasciolosis followed by those in the hills and plains, respectively. The prevalence of infection in cattle and buffaloes was highest during the winters (11.84% cattle, 15.57% buffaloes) followed by summers and rains, respectively. However, the seasonal trends in sheep and goats were the reverse, with the peak prevalence during the rains (4.60% sheep, 2.71% goats). Abattoir studies revealed a higher prevalence in buffaloes (31.14%) than in sheep and goats. Screening of Lymnaea auricularia snails revealed that 5.48% of the snails harboured larval stages of F. gigantica. Also, the snails in the tarai had a higher prevalence (7.28%) of infection compared to those in the plains (1.57%). The results of the present study may help to devise an effective control strategy against fasciolosis in north India.

Influence of two different geo-climatic zones on the prevalence and time trends of asthma symptoms among Spanish adolescents and schoolchildren

Few studies have focused on the long-term influence of the climate on the prevalence of asthma. The aim of this study is to establish the influence of geo-climatic conditions on the prevalence of asthma symptoms both in adolescents and schoolchildren, and to discover if this influence is associated with their time trends. Eight centres in Spain performed both ISAAC phases I (1994) and III (2002) in children 13-14 years old. Six of them also surveyed children 6-7 years old. For each age group and phase, about 3,000 children were surveyed per centre. This study examines the prevalence of current wheeze and severe current wheeze in two different geo-climatic zones, coast and plateau, considering their relative humidity and temperature range. In both age groups, the mean asthma prevalence on the coast, for phase I and III, was significantly higher than on the plateau. Living on the plateau was an independent protective factor for current wheeze and severe current wheeze for the two age groups. Within the coastal centres, the increase of the annual relative humidity was a statistical significant risk factor for current wheeze, the same trend existing for current severe wheeze. These effects were independent of the sex and of the phase of the study. The prevalence of asthma and severe asthma symptoms is more frequent on the coast of Spain as compared to the inner plateau. This finding was repeated both in 1994 and in 2002.

Applying Natural Sciences to Studying History: Regarding the Example of England and the Industrial Revolution Part II

In the first two articles of this series we introduced a model of evolutionary history, based on biological concepts, such as coenosis, geo-climatic zone, feeding chains etc. We showed that, historically, civilization evolved by gradually domesticating 6 distinct geo-climatic zones – corresponding to 6 traditional historic eras: from the first civilizations to the mass society of the 20th Century. We conclude the series with the study of economics within a zone. We show that each specific historic society evolved in order to take the best advantage of its unique resource, such as light loess soil of the first civilizations or oil of our days. The necessity of building a specific resource-dependent infrastructure, such as canals of antiquity, railways of the 19th century or highways of the 20th century, influenced every facet of life of the related society, from its leading technological style to the dominant form of ownership. The switch to a new resource was usually violent and could start well before the physical exhaustion of the older one – the latter’s growing scarcity and rising price generated a flurry of substitutes. In fierce competition between contenders the victory came on the basis of resource superiority. We show that the regular rhythms of K-waves, first noticed by Kondratieff on the example of prices in the 19th and the early 20th Centuries, correspond to the lifecycle of a resource-dependent infrastructure of an era. Â

Applying Natural Sciences to Studying History: Regarding the Example of England and the Industrial Revolution Part II

In this work we outline a bio-ecological approach to studying history. We show that human societies from the first civilizations to our days are techno-ecosystems and do not differ much from the natural ecosystems of a lake or a forest that are also restricted by their supplies of food. Below we call them coenoses (sing. coenosis) – this word from Greek is used in biology to denote a mutually dependent community of life-forms. Historically, a succession of distinctive nestled geo-climatic zones was domesticated as the older ones became exhausted due to growing demographic pressures. In this context, evolution is not synonymous with competition. Cooperation of mutually dependent species is crucial for domesticating a new ecosystem. At specific moments in its lifecycle, competition intensifies, leading to speciation. The dominant technology of each growing society serves as its unique adaptation to its geo-climatic zone. Using it, a particular society, just like a biological species, gains an evolutionary advantage over its neighbors by opening access to a new, previously inaccessible resource or, in plain English, a new source of food. For example, thermoregulation of warm blooded animals opened up colder habitats. Or, the use of canals in the uninhabited swamps of Mesopotamia paved the way to the irrigation agriculture of the great rivers’ deltas circa the V Millennium BC. It enormously increased both the grain yields and the population densities. The feeding chains that grew around the abundant grain evolved into the ancient egalitarian society, perfectly attuned to using mass labor. The 20th century, quite dissimilar in its technologies, customs, etc, unfolded according to the same master design. Oil deposits that, for millennia, sat around the world idly, turned into the foundation of the affluent consumer society, based on democracy. The car, along with the highways, suburbia and supermarkets became the symbol of modernity. Today, the amount of available food supplies is restricted by a single factor only, namely, the price of oil. Below, using an example from the Industrial Revolution, we will show that the process of utilizing a newfound resource by building a society around it is essentially cyclical. Social organisms evolve in regular and recurring patterns, not unlike birth, youth, maturity and death of biological beings. Each of these steps has its own functionality and must be lived through, much like the fact that one can’t mother children until she reaches puberty. That is why this approach possesses significant predictive capabilities.

Severing Red Alder: Timing the Cut to Achieve the Best Mortality

Abstract The best time to cut red alder varies. Mortality shifts across regional zones. The most effective time to cut is not determined by calendar date, but instead depends on environmental, biological, and physical factors that affect initial budbreak and potential mortality. Several trials and continuing observations lead the author to believe air temperature and seasonal moisture, along with carbohydrate reserve, are the more potent influences. These influences affect the time to begin cutting, how long cutting can continue, when cutting should stop, and the degree of mortality. Monitoring budbreak date and moisture patterns can be used to determine a favorable window of opportunity that will produce 50% or higher mortality on the cut red alder. The cutting window can be used across wide geoclimatic zones with good success. West. J. Appl. For. 18(3):199–201.

Capillary Gas Chromatographic Analysis of Eucalyptus globulus from Different Geoclimatic Zones in India

Eucalyptus globulus oils from four different geoclimatic zones in India were analyzed by gas chromatography for quality evaluation. Nineteen components were identified with the help of retention indices and co-injection technique. Among the four samples the oil from Bangalore was found to be of superior quality, containing highest percentage of 1,8-cineole

Mapping of Equipotential Zones for Cultivar Yield Pattern Evaluation

AbstractUsing data from a triticale advanced line yield trial network, we attempt to define the zones, in Portugal, within which the joint regression can be established with enough accuracy and precision to be of practical value.The procedure comprises the following steps: adjustment of the joint regressions for the whole area; evaluation of the residuals in each trial; previous identification of geoclimatic zones; comparison of these zones with the residuals; adjustment of the regressions for the zones confirmed in the previous analysis, and testing the differences between the regressions for each zone.The experimental conditions allowed the differentiation of two main zones: “Nordeste Transmontano” and “Sul de Montejunto‐Estrela”, however, another zone, included in the latter and designated “Alentejo Litoral e Algarve”, is suggested though further experimental data are needed for sound conclusions.

Serological survey for Toxoplasma infections in sheep.

A factorial-design survey was performed to determine the prevalence of specific antibody against Toxoplasma in young and adult sheep from 6 areas in 3 different geoclimatic zones in South Australia. Serum samples obtained from 1,159 sheep belonging to 59 flocks were tested by a conventional indirect haemagglutination test (IHAT) as well as by an enzyme-linked immunosorbent assay (ELISA) which used class-specific conjugates to detect both IgG and IgM against Toxoplasma. Titres greater than 64 were detected in 7.4%, 9.2% and 25.2% of the sheep by the IHAT, IgG-ELISA and IgM-ELISA respectively. A significant positive correlation was found between the results of the IgG-ELISA and the IHAT with identical results obtained for 1,050 samples. Antibody detected by all 3 tests was more prevalent and higher in titre in adult sheep than in lambs as well as in sheep from Kangaroo Island than in those from mainland South Australia. Although the regional differences in prevalence suggested a relationship with climate, no significant correlations were detected between the prevalence results and any single climatic factor; namely, average annual rainfall, average annual evaporation or mean temperature range.