Estudio socio-territorial de la actividad hortícola en el partido de La Plata 1998-2002

El presente trabajo se propone identificar y caracterizar las unidades de análisis espacio-territorial (fracciones censales) de la actividad primaria intensiva, específicamente hortícola, y examinar el peso relativo de la actividad del Partido de La Plata en el contexto provincial y nacional. Se analizan las variables sobre mano de obra, superficie total, superficie cultivada a campo y bajo cubierta, régimen de tenencia de la tierra y componentes tecnológicos. Se examinan y comparan los censos hortícola de la Provincia de Buenos Aires 1998 y Nacional Agropecuario 2002 (CNA02). Los resultados son presentados en tablas, gráficos y mapas temáticos procesados en SIG ArcView.

Estudio socio-territorial de la actividad hortícola en el partido de La Plata 1998-2002

El presente trabajo se propone identificar y caracterizar las unidades de análisis espacio-territorial (fracciones censales) de la actividad primaria intensiva, específicamente hortícola, y examinar el peso relativo de la actividad del Partido de La Plata en el contexto provincial y nacional. Se analizan las variables sobre mano de obra, superficie total, superficie cultivada a campo y bajo cubierta, régimen de tenencia de la tierra y componentes tecnológicos. Se examinan y comparan los censos hortícola de la Provincia de Buenos Aires 1998 y Nacional Agropecuario 2002 (CNA02). Los resultados son presentados en tablas, gráficos y mapas temáticos procesados en SIG ArcView.

Estudio socio-territorial de la actividad hortícola en el partido de La Plata 1998-2002

El presente trabajo se propone identificar y caracterizar las unidades de análisis espacio-territorial (fracciones censales) de la actividad primaria intensiva, específicamente hortícola, y examinar el peso relativo de la actividad del Partido de La Plata en el contexto provincial y nacional. Se analizan las variables sobre mano de obra, superficie total, superficie cultivada a campo y bajo cubierta, régimen de tenencia de la tierra y componentes tecnológicos. Se examinan y comparan los censos hortícola de la Provincia de Buenos Aires 1998 y Nacional Agropecuario 2002 (CNA02). Los resultados son presentados en tablas, gráficos y mapas temáticos procesados en SIG ArcView.

Integrating concrete and virtual materials in an elementary mathematics classroom : a case study of success with fractions

This paper describes an approach to introducing fraction concepts using generic software tools such as Microsoft Office's PowerPoint to create "virtual" materials for mathematics teaching and learning. This approach replicates existing concrete materials and integrates virtual materials with current non-computer methods of teaching primary students about fractions. The paper reports a case study of a 12-year-old student, Frank, who had an extremely limited understanding of fractions. Frank also lacked motivation for learning mathematics in general and interacted with his peers in a negative way during mathematics lessons. In just one classroom session involving the seamless integration of off-computer and on-computer activities, Frank acquired a basic understanding of simple common equivalent fractions. Further, he was observed as the session progressed to be an enthusiastic learner who offered to share his learning with his peers. The study's "virtual replication" approach for fractions involves the manipulation of concrete materials (folding paper regions) alongside the manipulation of their virtual equivalent (shading screen regions). As researchers have pointed out, the emergence of new technologies does not mean old technologies become redundant. Learning technologies have not replaced print and oral language or basic mathematical understanding. Instead, they are modifying, reshaping, and blending the ways in which humankind speaks, reads, writes, and works mathematically. Constructivist theories of learning and teaching argue that mathematics understanding is developed from concrete to pictorial to abstract and that, ultimately, mathematics learning and teaching is about refinement and expression of ideas and concepts. Therefore, by seamlessly integrating the use of concrete materials and virtual materials generated by computer software applications, an opportunity arises to enhance the teaching and learning value of both materials.

The status of Australian nurse practitioners : the first national census

A five-section questionnaire was mailed to all 234 authorised Australian nurse practitioners in late 2007. An 85% response rate was achieved (202 responses). Respondents had a mean age of 47.0 years and 84.2% were women. Only 145 nurse practitioners (72% of respondents) reported being employed in Australia at the time of the census. Emergency nurse practitioners were the most commonly employed nationally (26.9%). Nearly one third of employed nurse practitioners reported that they were still awaiting approval to prescribe medications despite this being a core legislated skill. Over 70% stated that lack of Medicare provider numbers and lack of authority to prescribe through the Pharmaceut ical Benef its Scheme was extremely limiting to their practice. These findings are consistent with the international literature describing establishment of reformative

Mixing colours: An ICT tool based on a semiotic framework for mathematical meaning-makng about ratio and fractions

This paper reports on the research and development of an ICT tool to facilitate the learning of ratio and fractions by adult prisoners. The design of the ICT tool was informed by a semiotic framework for mathematical meaning-making. The ICT tool thus employed multiple semiotic resources including topological, typological, and social-actional resources. The results showed that individual semiotic resource could only represent part of the mathematical concept, while at the same time it might signify something else to create a misconception. When multiple semiotic resources were utilised the mathematical ideas could be better learnt.

Mixing colours : an ICT tool based on a semiotic framework for mathematical meaning-making about ratio and fractions

This paper reports on the research and development of an ICT tool to facilitate the learning of ratio and fractions by adult prisoners. The design of the ICT tool was informed by a semiotic framework for mathematical meaning-making. The ICT tool thus employed multiple semiotic resources including topological, typological, and social-actional resources. The results showed that individual semiotic resource could only represent part of the mathematical concept, while at the same time it might signify something else to create a misconception. When multiple semiotic resources were utilised the mathematical ideas could be better learnt.

Fractions, reunitisation and the number-line representation

Centre for Mathematics and Science Education, QUT, Brisbane, Australia This paper reports on a study in which Years 6 and 10 students were individually interviewed to determine their ability to unitise and reunitise number lines used to represent mixed numbers and improper fractions. Only 16.7% of the students (all Year 6) were successful on all three tasks and, in general, Year 6 students outperformed Year 8 students. The interviews revealed that the remaining students had incomplete, fragmented or non-existent structural knowledge of mixed numbers and improper fractions, and were unable to unitise or reunitise number lines. The implication for teaching is that instruction should focus on providing students with a variety of fraction representations in order to develop rich and flexible schema for all fraction types (mixed numbers, and proper and improper fractions).

What's your other job : a census analysis of arts employment in Australia

This report applies CCI’s creative trident methodology with the definition of the arts as established by the Australia Council for the Arts to data sourced from Australia’s national census data (from 1996, 2001 and the most recent one in 2006). Analysis has been conducted on employment, income, gender, age and the nature of employment for artists and arts related workers within and beyond the arts industries, as well as other support workers in the arts industries.

The first Australian nurse practitioner census : a protocol to guide standardized collection of information about an emergent professional group

Internationally, collection of reliable data on new and evolving health-care roles is crucial. We describe a protocol for design and administration of a national census of an emergent health-care role, namely nurse practitioners in Australia using databases held by regulatory authorities. A questionnaire was developed to obtain data on the role and scope of practice of Australian nurse practitioners. Our tool comprised five sections and included a total of 56 questions, using 28 existing items from the National Nursing and Midwifery Labour Force Census and nine items recommended in the Nurse Practitioner Workforce Planning Minimum Data Set. Australian Nurse Registering Authorities (n = 6) distributed the survey on our behalf. This paper outlines our instrument and methods. The survey was administered to 238 authorized Australian nurse practitioners (85% response rate). Rigorous collection of standardized items will ensure health policy is informed by reliable and valid data. We will re-administer the survey 2 years following the first survey to measure change over time.

Soil management effects on organic carbon in isolated fractions of a Gray Luvisol

Agricultural management affects soil organic matter, which is important for sustainable crop production and as a greenhouse gas sink. Our objective was to determine how tillage, residue management and N fertilization affect organic C in unprotected, and physically, chemically and biochemically protected soil C pools. Samples from Breton, Alberta were fractionated and analysed for organic C content. As in previous report, N fertilization had a positive effect, tillage had a minimal effect, and straw management had no effect on whole-soil organic C. Tillage and straw management did not alter organic C concentrations in the isolated C pools, while N fertilization increased C concentrations in all pools. Compared with a woodlot soil, the cultivated plots had lower total organic C, and the C was redistributed among isolated pools. The free light fraction and coarse particulate organic matter responded positively to C inputs, suggesting that much of the accumulated organic C occurred in an unprotected pool. The easily dispersed silt-sized fraction was the mineral-associated pool most responsive to changes in C inputs, whereas the microaggregate-derived silt-sized fraction best preserved C upon cultivation. These findings suggest that the silt-sized fraction is important for the long-term stabilization of organic matter through both physical occlusion in microaggregates and chemical protection by mineral association.

Acid hydrolysis of easily dispersed and microaggregate-derived silt- and clay-sized fractions to isolate resistant soil organic matter

The current paradigm in soil organic matter (SOM) dynamics is that the proportion of biologically resistant SOM will increase when total SOM decreases. Recently, several studies have focused on identifying functional pools of resistant SOM consistent with expected behaviours. Our objective was to combine physical and chemical approaches to isolate and quantify biologically resistant SOM by applying acid hydrolysis treatments to physically isolated silt- and clay-sized soil fractions. Microaggegrate-derived and easily dispersed silt- and clay-sized fractions were isolated from surface soil samples collected from six long-term agricultural experiment sites across North America. These fractions were hydrolysed to quantify the non-hydrolysable fraction, which was hypothesized to represent a functional pool of resistant SOM. Organic C and total N concentrations in the four isolated fractions decreased in the order: native > no-till > conventional-till at all sites. Concentrations of non-hydrolysable C (NHC) and N (NHN) were strongly correlated with initial concentrations, and C hydrolysability was found to be invariant with management treatment. Organic C was less hydrolysable than N, and overall, resistance to acid hydrolysis was greater in the silt-sized fractions compared with the clay-sized fractions. The acid hydrolysis results are inconsistent with the current behaviour of increasing recalcitrance with decreasing SOM content: while %NHN was greater in cultivated soils compared with their native analogues, %NHC did not increase with decreasing total organic C concentrations. The analyses revealed an interaction between biochemical and physical protection mechanisms that acts to preserve SOM in fine mineral fractions, but the inconsistency of the pool size with expected behaviour remains to be fully explained.