Significant Factors Influencing the Quality and Success of Supervised Farming Programs of Vocational Agriculture Students in Seven Schools of East Tennessee

(From the Introduction) This is a study of significant factors influencing the quality and success of supervised farming programs of vocational agricultural students in seven schools of East Tennessee. This study embodies the elements of the home, farm and school planning

Greenhouse gas emissions from soils under organic management

This report was presented at the UK Organic Research 2002 Conference. Land emissions of N2O, CO2 and NH3 have been subject to little study under organic systems, yet form important aspects of sustainability of such systems. We describe innovative methods developed at SAC to assess trace gas emission using both automatic closed chamber systems (intensive, short term monitoring) and manually-operated closed chamber systems (occasional, long term monitoring). Long-term data were collected from organic ley-arable rotation trials in North-east of Scotland. Short term data were collected to show the effect of timing and depth of ploughing-out of the ley phase on gas emissions. Ploughing gave a shortterm stimulation of CO2 and, more markedly, of N2O emission. Emissions of N2O from organic grass-clover leys were considerably lower than from conventional grass. However, some N2O emissions from organic arable are higher than from conventional systems, particularly in the first year after ploughing out ley. Ammonia emissions after spreading manure on grass were significant in the summer, though only short-lived

Comparative population structure of <i>Plasmodium malariae</i> and <i>Plasmodium falciparum</i> under different transmission settings in Malawi

&lt;b&gt;Background:&lt;/b&gt; Described here is the first population genetic study of Plasmodium malariae, the causative agent of quartan malaria. Although not as deadly as Plasmodium falciparum, P. malariae is more common than previously thought, and is frequently in sympatry and co-infection with P. falciparum, making its study increasingly important. This study compares the population parameters of the two species in two districts of Malawi with different malaria transmission patterns - one seasonal, one perennial - to explore the effects of transmission on population structures. &lt;BR/&gt; &lt;b&gt;Methods:&lt;/b&gt; Six species-specific microsatellite markers were used to analyse 257 P. malariae samples and 257 P. falciparum samples matched for age, gender and village of residence. Allele sizes were scored to within 2 bp for each locus and haplotypes were constructed from dominant alleles in multiple infections. Analysis of multiplicity of infection (MOI), population differentiation, clustering of haplotypes and linkage disequilibrium was performed for both species. Regression analyses were used to determine association of MOI measurements with clinical malaria parameters. &lt;BR/&gt; &lt;b&gt;Results:&lt;/b&gt; Multiple-genotype infections within each species were common in both districts, accounting for 86.0% of P. falciparum and 73.2% of P. malariae infections and did not differ significantly with transmission setting. Mean MOI of P. falciparum was increased under perennial transmission compared with seasonal (3.14 vs 2.59, p = 0.008) and was greater in children compared with adults. In contrast, P. malariae mean MOI was similar between transmission settings (2.12 vs 2.11) and there was no difference between children and adults. Population differentiation showed no significant differences between villages or districts for either species. There was no evidence of geographical clustering of haplotypes. Linkage disequilibrium amongst loci was found only for P. falciparum samples from the seasonal transmission setting. &lt;BR/&gt; &lt;b&gt;Conclusions:&lt;/b&gt; The extent of similarity between P. falciparum and P. malariae population structure described by the high level of multiple infection, the lack of significant population differentiation or haplotype clustering and lack of linkage disequilibrium is surprising given the differences in the biological features of these species that suggest a reduced potential for out-crossing and transmission in P. malariae. The absence of a rise in P. malariae MOI with increased transmission or a reduction in MOI with age could be explained by differences in the duration of infection or degree of immunity compared to P. falciparum

La réussite scolaire des élèves issus de l’immigration : une question de classe sociale, de langue ou de culture?

Dans cet article, les auteurs présentent successivement deux études de cas basées sur une utilisation originale des banques de données administratives produites par les ministères de l’Éducation de la Colombie-Britannique et du Québec. Les deux études sont différentes, tant en ce qui concerne l’indicateur retenu (la performance scolaire aux examens versus la diplomation au secondaire) que la définition du groupe cible (les élèves allophones versus les élèves noirs). Toutefois, une lecture croisée de leurs résultats révèle des tendances largement convergentes en ce qui concerne l’importance des différences intergroupes en matière de réussite scolaire ainsi que les facteurs qui l’influencent. À cet égard, l’origine des élèves et leur maîtrise de la langue s’avèrent plus significatives que leur appartenance socio-économique. De plus, certains facteurs jouent différemment de chez l’ensemble de la population : le déficit des garçons et des élèves arrivés en retard au secondaire est, en effet, moins important.In this article, the authors successively present two case studies based on an original use of administrative data banks produced by the Québec and British Columbia Departments of Education. The studies differ both in terms of the indicator used (school performance in exams versus the high school graduation rate), and the definition of the target group (allophone students versus black students). However, a comparison of their results reveals largely converging trends on school success and factors that influence it in relation to the importance of inter-group differences. In this respect, the students’ origins and their mastery of the language is more significant than their socio-economic group. Certain factors have a different effect than for the overall population. The boys’ deficit and arriving at secondary school late are, in fact, less important.En este artículo, los autores presentan sucesivamente dos estudios de caso basados en la utilización original de bancos de datos administrativos hechos por los ministerios de la Educación de Colombia Británica y de Quebec. Se trata de dos estudios diferentes, tanto en lo que concierne al indicador retenido (el resultado escolar en los exámenes versus la obtención del diploma en secundaria) que la definición del grupo seleccionado (los alumnos alófonos versus los alumnos negros). Sin embargo, una lectura comparada de los resultados muestra tendencias ampliamente convergentes en lo que concierne la importancia de diferencias entre los grupos en materia de logro escolar así como en los factores que lo influencian. Al respecto, el origen de los alumnos y su dominio de la lengua aparecen más significativos que su pertenencia socioeconómica. Además, ciertos factores actúan de manera diferente al conjunto de la población: el déficit de los jóvenes y de los alumnos que ingresaron tardíamente en secundaria es, efectivamente, menos importante

Aberrant crypt foci and microadenoma as markers for colon cancer.

Foci of aberrant crypts similar to those seen in experimental animals exposed to colon carcinogens have been identified and quantified on the mucosal surface of fixed resections of human colon after methylene blue staining. Many of the foci in humans showed dysplasia on histologic examination and were considered to be microadenoma (MA). These lesions may be precursors for adenomatous polyps and colorectal cancer. Rats and mice initiated with azoxymethane, then fed diets containing sucrose or casein heated at 180 degrees C to stimulate normal cooking conditions, had three to five times more large MA after 100 days than controls. Thus, cooked sugar and protein contain promoters of the growth of colonic MA. 5-Hydroxymethylfuraldehyde was identified as a promoter in cooked sugar

The Plasmodium falciparum, Nima-related kinase Pfnek-4: a marker for asexual parasites committed to sexual differentiation

&lt;b&gt;Background&lt;/b&gt; Malaria parasites undergo, in the vertebrate host, a developmental switch from asexual replication to sexual differentiation leading to the formation of gametocytes, the only form able to survive in the mosquito vector. Regulation of the onset of the sexual phase remains largely unknown and represents an important gap in the understanding of the parasite's complex biology. &lt;b&gt;Methods:&lt;/b&gt; The expression and function of the Nima-related kinase Pfnek-4 during the early sexual development of the human malaria parasite Plasmodium falciparum were investigated, using three types of transgenic Plasmodium falciparum 3D7 lines: (i) episomally expressing a Pfnek-4-GFP fusion protein under the control of its cognate pfnek-4 promoter; (ii) episomally expressing negative or positive selectable markers, yeast cytosine deaminase-uridyl phosphoribosyl transferase, or human dihydrofolate reductase, under the control of the pfnek-4 promoter; and (iii) lacking a functional pfnek-4 gene. Parasite transfectants were analysed by fluorescence microscopy and flow cytometry. In vitro growth rate and gametocyte formation were determined by Giemsa-stained blood smears. &lt;b&gt;Results:&lt;/b&gt; The Pfnek-4-GFP protein was found to be expressed in stage II to V gametocytes and, unexpectedly, in a subset of asexual-stage parasites undergoing schizogony. Culture conditions stimulating gametocyte formation resulted in significant increase of this schizont subpopulation. Moreover, sorted asexual parasites expressing the Pfnek-4-GFP protein displayed elevated gametocyte formation when returned to in vitro culture in presence of fresh red blood cells, when compared to GFP- parasites from the same initial population. Negative selection of asexual parasites expressing pfnek-4 showed a marginal reduction in growth rate, whereas positive selection caused a marked reduction in parasitaemia, but was not sufficient to completely abolish proliferation. Pfnek-4- clones are not affected in their asexual growth and produced normal numbers of stage V gametocytes. &lt;b&gt;Conclusions:&lt;/b&gt; The results indicate that Pfnek-4 is not strictly gametocyte-specific, and is expressed in a small subset of asexual parasites displaying high rate conversion to sexual development. Pfnek-4 is not required for erythrocytic schizogony and gametocytogenesis. This is the first study to report the use of a molecular marker for the sorting of sexually-committed schizont stage P. falciparum parasites, which opens the way to molecular characterization of this pre-differentiated subpopulation

Use of a dual reporter plasmid to demonstrate bactofection with an attenuated aroa- derivative of Pasteurella multocida b:2

A reporter plasmid pSRG has been developed which expresses red fluorescent protein (RFP) from a constitutive prokaryotic promoter within Pasteurella multocida B:2 and green fluorescent protein (GFP) from a constitutive eukaryotic promoter within mammalian cells. This construct has been used to determine the location and viability of the bacteria when moving from the extracellular environment into the intracellular compartment of mammalian cells. Invasion assays with embryonic bovine lung (EBL) cells and an attenuated AroA- derivative of Pasteurella multocida B:2 (strain JRMT12), harbouring the plasmid pSRG, showed that RFP-expressing bacteria could be detected intracellularly at 3 h post-invasion. At this stage, some EBL cells harbouring RFP-expressing bacteria were observed to express GFP simultaneously, indicating release of the plasmid into the intracellular environment. At 5 h post-invasion, more EBL cells were expressing GFP, while still harbouring RFP-expressing bacteria. Concurrently, some EBL cells were shown to express only GFP, indicating loss of viable bacteria within these cells. These experiments proved the functionality of the pSRG dual reporter system and the potential of P. multocida B:2 JRMT12 for bactofection and delivery of a DNA vaccine

Quality and effectiveness of different approaches to primary care delivery in Brazil

BACKGROUND: Since 1994, Brazil has developed a primary care system based on multidisciplinary teams which include not only a physician and a nurse, but also 4–6 lay community health workers. This system now consists of 26,650 teams, covering 46% of the Brazilian population. Yet relatively few investigations have examined its effectiveness, especially in contrast with that of the traditional multi-specialty physician team approach it is replacing, or that of other existing family medicine approaches placing less emphasis on lay community health workers. Primary health care can be defined through its domains of access to first contact, continuity, coordination, comprehensiveness, community orientation and family orientation. These attributes can be ascertained via instruments such as the Primary Care Assessment Tool (PCATool), and correlated with the effectiveness of care. The objectives of our study are to validate the adult version of this instrument in Portuguese, identify the extent (quality) of primary care present in different models of primary care services, and correlate this extent with measures of process and outcomes in patients with diabetes, hypertension and coronary heart disease (CHD). METHODS/DESIGN: We are conducting a population-based cross-sectional study of primary care in the municipality of Porto Alegre. We will interview a random sample totaling 3000 adults residing in geographic areas covered by four distinct models of primary care of the Brazilian national health system or, alternatively, by one nationally prominent complementary health care service, as well as the physicians and nurses of the health teams of these services. Interviews query perceived quality of care (PCATool-Adult Version), patient satisfaction, and process indicators of management of diabetes, hypertension and known CHD. We are measuring blood pressure, anthropometrics and, in adults with known diabetes, glycated hemoglobin. DISCUSSION: We hope to contribute not only by validating the PCATool-Adult Version for use in Brazil, but also by furnishing ample data concerning the appropriate mix of health care professionals in the primary care team, a question of international import. Once validated, future use of this instrument should help direct advances aiming at improving the quality of primary care in Brazil

Merozoite surface protein-3α is a reliable marker for population genetic analysis of Plasmodium vivax

BACKGROUND: The knowledge on population structure of the parasite isolates has contributed greatly to understanding the dynamics of the disease transmission for designing and evaluating malaria vaccines as well as for drug applications. msp-1 and msp-3α genes have been used as a genetic marker in population studies of Plasmodium vivax isolates. In this study, msp-3α was compared and assessed with msp-1 marker in order to find whether msp-3α is a reliable genetic marker for P. vivax population studies. METHODS: This comparative study was designed and carried out as the first assessment of diversity in Pvmsp-3α gene by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in the 50 northern and 94 southern P. vivax isolates from Iran, which had been analysed before for msp-1 gene. RESULTS: Three allele size as, Type A (1.8 kb), Type B (1.5 kb) and Type C (1.2 kb) have been detected among both northern and southern isolates based on PCR results. Type C (70%) and Type A (68.7%) were the predominant fragments among northern and southern parasites, respectively. 99 distinct Pvmsp-3α fragments defined by the size were detected in the 94 southern samples by PCR analysis. However, no mixed genotype infections have been detected among northern isolates. Based on restriction pattern from digestion with Hha I and Alu I 12 and 49 distinct allelic variants have been detected among 50 northern and 94 southern isolates. However, based on msp-1 gene, 30 distinct variants identified in all 146-sequenced Iranian P. vivax isolate. CONCLUSION: The results suggested that PCR-RFLP on msp-3α gene is an adequate, applicable and easily used technique for molecular epidemiology studies of P. vivax isolates without the need for further sequencing analysis