992 resultados para 107-655B
Resumo:
Heliothine moths (Lepidoptera: Heliothinae) include some of the world's most devastating pest species. Whereas the majority of nonpest heliothinae specialize on a single plant family, genus, or species, pest species are highly polyphagous, with populations often escalating in size as they move from one crop species to another. Here, we examine the current literature on heliothine host-selection behavior with the aim of providing a knowledge base for research scientists and pest managers. We review the host relations of pest heliothines, with a particular focus on Helicoverpa armigera (Hubner), the most economically damaging of all heliothine species. We then consider the important question of what constitutes a host plant in these moths, and some of the problems that arise when trying to determine host plant status from empirical studies on host use. The top six host plant families in the two main Australian pest species (H. armigera and Helicoverpa punctigera Wallengren) are the same and the top three (Asteraceae, Fabaceae, and Malvaceae) are ranked the same (in terms of the number of host species on which eggs or larvae have been identified), suggesting that these species may use similar cues to identify their hosts. In contrast, for the two key pest heliothines in the Americas, the Fabaceae contains approximate to 1/3 of hosts for both. For Helicoverpa zea (Boddie), the remaining hosts are more evenly distributed, with Solanaceae next, followed by Poaceae, Asteraceae, Malvaceae, and Rosaceae. For Heliothis virescens (F.), the next highest five families are Malvaceae, Asteraceae, Solanaceae, Convolvulaceae, and Scrophulariaceae. Again there is considerable overlap in host use at generic and even species level. H. armigera is the most widely distributed and recorded from 68 plant families worldwide, but only 14 families are recorded as a containing a host in all geographic areas. A few crop hosts are used throughout the range as expected, but in some cases there are anomalies, perhaps because host plant relation studies are not comparable. Studies on the attraction of heliothines to plant odors are examined in the context of our current understanding of insect olfaction, with the aim of better understanding the connection between odor perception and host choice. Finally, we discuss research into sustainable management of pest heliothines using knowledge of heliothine behavior and ecology. A coordinated international research effort is needed to advance our knowledge on host relations in widely distributed polyphagous species instead of the localized, piecemeal approaches to understanding these insects that has been the norm to date.
Resumo:
Urinary tract infections (UTI) are among the most common infectious diseases of humans and are the most common nosocomial infections in the developed world. It is estimated that 40–50% of women and 5% of men will develop a UTI in their lifetime, and UTI accounts for more than 1 million hospitalizations and $1.6 billion in medical expenses each year in the USA. Uropathogenic Escherichia coli (UPEC) is the primary cause of UTI. This review presents an overview of recent discoveries related to the primary virulence factors of UPEC and major innate immune responses to infection of the lower urinary tract. New and emerging themes in UPEC research are discussed in the context of the interface between host and pathogen.
Resumo:
Glutathione transferases are known to be important enzymes in the metabolism of xenobiotics. In humans genetic polymorphisms have been reported for the hGSTM1 and hGSTT1 genes leading to individual differences in susceptibility towards toxic effects, such as cancer. This study describes the distribution of the two polymorphisms of hGSTT1 and hGSTM1 in the normal Chinese population of Shanghai. Out of 219 healthy individuals having been genotyped for GSTTI and GSTMI, 108 (49%) were identified to be homozygously deficient for the GSTT1 gene and 107 (49%) for the GSTM1 gene.
Resumo:
XRF spectrometry was applied to provenance studies of Iron Age pottery specimens that originated from the Mngeni river area in South Africa. Ten transition metals (Sc to Zn) mere determined in 107 potsherds, excavated from four different sites. The data were subjected to a computerized mathematical technique (correspondence analysis), which was used to group the samples according to the similarity of their elemental distributions. The groupings were interpreted in terms of social or cultural interaction between the sites. (C) 1997 by John Wiley & Sons, Ltd.
Resumo:
Provenance studies of iron-age pottery specimens originating from the Mngeni river area in South Africa was carried out by applying XRF spectrometry. A total of sixteen major and trace elements were analysed in a batch of 107 potsherds, excavated from four different archaeological sites in the aforementioned area. A multivariate statistical programme Correspondence Analysis was used in this study to obtain the relevant clustering patterns according to the similarity of the elemental distributions. Differences and similarities in the clusters obtained for the majors and trace elements are discussed.
Resumo:
A straightforward procedure for the acid digestion of geological samples with SiO2 concentrations ranging between about 40 to 80%, is described. A powdered sample (200 mesh) of 500 mg was used and fused with 1000 mg spectroflux at about 1000 degreesC in a platinum crucible. The molten was subsequently digested in an aqueous solution of HNO3 at 100 degreesC. Several systematic digestion procedures were followed using various concentrations of HNO3. It was found that a relationship could be established between the dissolution-time and acid concentration. For an acid concentration of 15% an optimum dissolution-time of under 4 min was recorded. To verify that the dissolutions were complete, they were subjected to rigorous quality control tests. The turbidity and viscosity were examined at different intervals and the results were compared with that of deionised water. No significant change in either parameter was observed. The shelf-life of each solution lasted for several months, after which time polymeric silicic acid formed in some solutions, resulting in the presence of a gelatinous solid. The method is cost effective and is clearly well suited for routine applications on a small scale, especially in laboratories in developing countries. ICP-MS was applied to the determination of 13 Rare Earth Elements and Hf in a set of 107 archaeological samples subjected to the above digestion procedure. The distribution of these elements was examined and the possibility of using the REE's for provenance studies is discussed.
Resumo:
In current practice, urban-rural development has been regarded as one of the key pillars in driving regenerative development that includes economic, social, and environmental balance. In association with rapid urbanization, an important contemporary issue in China is that its rural areas are increasingly lagging behind urban areas in their development and a coordinated provision of public facilities in rural areas is necessary to achieve a better balance. A model is therefore introduced for quantifying the effect of individual infrastructure projects on urban-rural balance (e-UR) by focusing on two attributes, namely, efficiency and equity. The model is demonstrated through a multi-criteria model, developed with data collected from infrastructure projects in Chongqing, with the criteria values for each project being scored by comparing data collected from the project involved with e-UR neutral “benchmark” values derived from a survey of experts in the field. The model helps evaluate the contribution of the projects to improving rural-urban balance and hence enable government decision-makers for the first time to prioritize future projects rigorously in terms of their likely contribution too.
Resumo:
Knowledge-based urban development (KBUD) has become a popular pursuit for cities especially from the developing countries to fast track the catching up process with their developed nation counterparts. Nevertheless, the KBUD progress for these cities is highly daunting and full of confronts. This paper aims to shed light on the major KBUD challenges of emerging local economies by undertaking an in-depth empirical investigation in one of these cities. The paper scrutinizes the prospects and constraints of Istanbul in her KBUD journey through comparative performance and policy context analyses. The findings reveal invaluable insights not only for Istanbul to reshape the policy context and better align the development with contemporary KBUD perspectives, but also for other emerging local economies to learn from these experiences.
Resumo:
Purpose To examine the implementation of quality management systems (QMSs) of Grade 7 (G-7) Indonesian construction companies. This includes the initial motives that have driven the development of QMSs, barriers to effective QMS implementation, the current practice and integration of QMS-ISO 9001 principles and elements, and the performance of contractors implementing such QMSs. Design/methodology/approach A survey was conducted involving 403 respondents (Quality Management Representatives, Managers, and Project and Site Engineers) from 77 G-7 as well as ISO 9001 certified Indonesian construction companies. Findings The main motive for G-7 contractors in establishing and implementing ISO 9001 based QMSs are identified as being to effectively and efficiently control project activities. Respondents apparently do not often experience problems related to QMS implementation. However, issues of management attitude and purpose are identified as barriers that may affect effective QMS implementation. The study highlights the ISO 9001 principles and elements that still require to be more critically applied by G-7 contractors in order to fully implement and improve their current QMS effectiveness. The findings also suggest that, although certified, many G-7 contractors have not yet achieved a satisfactory level of performance to be truly competitive in global markets outside Indonesia. Originality/value To date, only limited research has been conducted into the application of ISO 9001 in the Indonesian construction industry. The research findings reinforced the value of pursuing more effective QMS implementation. They also support current attempts to introduce ISO 9001 QMSs to a much wider base of Indonesian construction companies, particularly small and medium sized contractors and builders.
Resumo:
In this paper, the axial performance of two heavily instrumented barrette piles, with and without grouting, socket into gravel layer in Taipei are evaluated based on the results of pile load tests. Both piles are 44 m long with the same dimension of 0.8 by 2.7 m, installed by hydraulic long bucket. One of the piles with toe grouting was socket 6 m into gravel layer and the other pile without toe grouting was socket 3 m into gravel layer. The load versus displacement relationships at pile head, the t-z curves of upper soil layers and of bottom gravel layer, and the tip resistance versus displacement relationships are important concerns and are presented in the paper. The t-z curves interpreted from the measured data along depth are also simulated by the hyperbolic model.
Resumo:
Background Up-to-date evidence on levels and trends for age-sex-specific all-cause and cause-specific mortality is essential for the formation of global, regional, and national health policies. In the Global Burden of Disease Study 2013 (GBD 2013) we estimated yearly deaths for 188 countries between 1990, and 2013. We used the results to assess whether there is epidemiological convergence across countries. Methods We estimated age-sex-specific all-cause mortality using the GBD 2010 methods with some refinements to improve accuracy applied to an updated database of vital registration, survey, and census data. We generally estimated cause of death as in the GBD 2010. Key improvements included the addition of more recent vital registration data for 72 countries, an updated verbal autopsy literature review, two new and detailed data systems for China, and more detail for Mexico, UK, Turkey, and Russia. We improved statistical models for garbage code redistribution. We used six different modelling strategies across the 240 causes; cause of death ensemble modelling (CODEm) was the dominant strategy for causes with sufficient information. Trends for Alzheimer's disease and other dementias were informed by meta-regression of prevalence studies. For pathogen-specific causes of diarrhoea and lower respiratory infections we used a counterfactual approach. We computed two measures of convergence (inequality) across countries: the average relative difference across all pairs of countries (Gini coefficient) and the average absolute difference across countries. To summarise broad findings, we used multiple decrement life-tables to decompose probabilities of death from birth to exact age 15 years, from exact age 15 years to exact age 50 years, and from exact age 50 years to exact age 75 years, and life expectancy at birth into major causes. For all quantities reported, we computed 95% uncertainty intervals (UIs). We constrained cause-specific fractions within each age-sex-country-year group to sum to all-cause mortality based on draws from the uncertainty distributions. Findings Global life expectancy for both sexes increased from 65·3 years (UI 65·0–65·6) in 1990, to 71·5 years (UI 71·0–71·9) in 2013, while the number of deaths increased from 47·5 million (UI 46·8–48·2) to 54·9 million (UI 53·6–56·3) over the same interval. Global progress masked variation by age and sex: for children, average absolute differences between countries decreased but relative differences increased. For women aged 25–39 years and older than 75 years and for men aged 20–49 years and 65 years and older, both absolute and relative differences increased. Decomposition of global and regional life expectancy showed the prominent role of reductions in age-standardised death rates for cardiovascular diseases and cancers in high-income regions, and reductions in child deaths from diarrhoea, lower respiratory infections, and neonatal causes in low-income regions. HIV/AIDS reduced life expectancy in southern sub-Saharan Africa. For most communicable causes of death both numbers of deaths and age-standardised death rates fell whereas for most non-communicable causes, demographic shifts have increased numbers of deaths but decreased age-standardised death rates. Global deaths from injury increased by 10·7%, from 4·3 million deaths in 1990 to 4·8 million in 2013; but age-standardised rates declined over the same period by 21%. For some causes of more than 100 000 deaths per year in 2013, age-standardised death rates increased between 1990 and 2013, including HIV/AIDS, pancreatic cancer, atrial fibrillation and flutter, drug use disorders, diabetes, chronic kidney disease, and sickle-cell anaemias. Diarrhoeal diseases, lower respiratory infections, neonatal causes, and malaria are still in the top five causes of death in children younger than 5 years. The most important pathogens are rotavirus for diarrhoea and pneumococcus for lower respiratory infections. Country-specific probabilities of death over three phases of life were substantially varied between and within regions. Interpretation For most countries, the general pattern of reductions in age-sex specific mortality has been associated with a progressive shift towards a larger share of the remaining deaths caused by non-communicable disease and injuries. Assessing epidemiological convergence across countries depends on whether an absolute or relative measure of inequality is used. Nevertheless, age-standardised death rates for seven substantial causes are increasing, suggesting the potential for reversals in some countries. Important gaps exist in the empirical data for cause of death estimates for some countries; for example, no national data for India are available for the past decade.
Resumo:
The use of GNSS tracked Lagrangian drifters allows more realistic quantification of fluid motion and dispersion coefficients than Eulerian techniques because such drifters are analogues of particles that are relevant to flow field characterisation and pollutant dispersion. Using the fast growing Real Time Kinematic (RTK) positioning technique derived from Global Satellite Navigation Systems (GNSS), drifters are developed for high frequency (10 Hz) sampling with position estimates to centimetre accuracy. The drifters are designed with small size and less direct wind drag to follow the sub-surface flow which characterizes dispersion in shallow waters. An analysis of position error from stationary observation indicates that the drifter can efficiently resolve motion up to 1 Hz. The result of the field deployments of the drifter in conjunction with acoustic Eulerian devices shows higher estimate of the drifter streamwise velocities. Single particle statistical analysis of field deployments in a shallow estuarine zone yielded dispersion coefficients estimate comparable to those of dye tracer studies. The drifters capture the tidal elevation during field studies in a tidal estuary.