Análise conjunta de regressões : ajustamento e zonagem agrícola

A Análise conjunta de regressões, ACR, é uma técnica utitilizada para estudar a interação gentipo x ambiente baseada em regressões. Nesta técnica ajusta-se uma regressão linear por cultivar. Nestas regressões a variável controlada é o índice ambiental que mede a produtividade dos vários ambientes. Nas culturas anuais, os ambientes compreendem aos pares (local, ano). Os valores dos índices ambientais e dos coeficientes das regressões são ajustados simultaneamente. Até agora a ACR tem sido aplicada a uma única cultura de cada vez. Neste trabalho vamos procurar ultrapassar essa limitação através da modelação dos logaritmos dos índices ambientais tendo-se desenvolvido um modelo da forma: zi, j  v  l j  j , i  1,...,n, J  1,...,n onde zi , j é o logaritmo do índice ambiental para o i-essimo ambiente na j  essima cultura , v um valor médio geral , li j  essimo cultivar. o efeito do i  essimo local e  j o efeito do Ao utilizar esta modelação, os locais corresponderão a estações experimentais de forma a poder-se ter várias culturas no mesmo local. Ora, as estações experimentais são escolhidas por forma a serem representativas das regiões onde estão implantadas. Assim, os índices ambientais correspondentes às várias estações experimentais e, consequentemente, às respetivas regiões, pudesse ser utilizados para agrupar regiões contíguas com índices semelhantes obtendo-se assim, um elemento interessante para a Zonagem agrícola no que diz respeito às culturas que se trabalha. Pode-se ainda procurar uma Zonagem para grupos de cultivares. Por exemplo, adiante trabalharemos com dados da cevada e trigo os quais são cereais. ABSTRACT: Joint Regression Analysis, JRA, is one of the techniques for the study of genotypeXenvironment interaction based on the use of regressions .In JRA a linear regression of the yields of each cultivar on a controlled variable, the environment index ,is adjusted .The index miss erasures the productivity of each environment .In yearly cultures the environments correspond to the pairs (location ,years) .These indexes and the correlation coefficients are adjusted simultaneously. Up to now JRA has been applied to single crops .Now we try to overcome this restriction through modeling of the logarithms of the environmental indexes .We developed a model τ i , j = v + l j +λ j , i = 1,..., b, J = 1,...J where τ i , j is the logarithm of the environmental index for the i-th environment and the j-th crop , v is the general mean , li is the effect of the i-th environment and λ j is the effect of the j-th crop . When applying this model the location will correspond to experimental situations in order to have several crops in the same locations .Now experimental stations are chosen to be representative of the regions in which they are located .Then the l1 ,..., lb can be used to group contiguous regions with similar location effects .We thus get an useful tool for Agricultural Zoning for the crops we used or, even, for the group to which those crops belong . For instance we worked with barley and wheat that are cereals.

Comportamento alimentar e excesso de peso em profissionais do sector da saúde

A prevalência da obesidade está a aumentar nos países desenvolvidos e Portugal não é excepção. O presente trabalho teve como principal objectivo caracterizar a situação relativamente aos parâmetros antropométricos e hábitos alimentares de várias categorias profissionais do sector da saúde de uma instituição hospitalar do distrito de Lisboa. Com efeito, verificou-se que existem diferenças ao nível do Índice de Massa Corporal (IMC), da massa gorda e muscular e do perímetro de cintura entre as profissões estudadas (assistentes operacionais, enfermeiros, médicos e técnicos de diagnóstico e terapêutica). De acordo com a classificação do IMC, o grupo estudado situou-se no cut-off superior do ‘peso normal’ (IMC de 24,9 kg/m2). A obesidade esteve presente em 29% dos assistentes operacionais, 9% nos médicos e 5% nos enfermeiros e técnicos de diagnóstico e terapêutica. Também se observaram diferenças entre os géneros feminino e masculino, já que neste último o IMC foi de 26,5 kg/m2 e no primeiro foi de 24,6 kg/m2. Quanto aos hábitos alimentares, através do questionário de frequência alimentar (QFA) e após comparar com as recomendações da pirâmide dos alimentos mediterrânica e com a roda dos alimentos, foi notório o desvio do padrão alimentar face ao que é preconizado por estas representações. Assim, a maioria dos indivíduos não ingere produtos lácteos, pão, cereais e derivados com a frequência que seria adequada. Também se observaram diferenças no reporte de ingestão dos mesmos alimentos entre as categorias profissionais, salientando que todas estas apresentam padrões de ingestão desviantes das recomendações defendidas pela pirâmide dos alimentos mediterrânica e pela roda dos alimentos. Na sociedade actual, o local de trabalho é cada vez mais obesogénico devido quer à mudança na natureza do trabalho, quer às condições em que este decorre. Face aos resultados obtidos foi elaborado um plano de intervenção sócio- organizacional que visa promover hábitos alimentares e estilos de vida saudáveis. /ABSTRACT: Obesity prevalence is increasing all over developed countries, and Portugal is no exception. The present study had as major objective to describe the situation relative to anthropometric measures and dietary habits of several job strains operating in the health sector of a Lisbon district’s central hospital. Indeed, it has been verified that there are differences as concern to Body Mass Index (BMI), fat and muscle mass and waist circumference among the job strains studied (operational assistants, nurses, physicians and diagnostic and therapeutic technicians). According to BMI classification, the sample showed to be lined up with the superior BMI cut-off value for “normal weight” (BMI of 24,9 kg/m2). Obesity was present in 29% of operational assistants, 9% in physicians, 5% in nurses and diagnostic and therapeutic technicians. There were differences in both feminine and masculine genders, as in the latter the BMI was 26,5 kg/m2 and in the first, 24,6 kg/m2. As concern to dietary habits, through the application of the food frequency questionnaire (FFQ), after comparing with mediterranean food pyramid and wheel of foods it was notorious the deviation of dietary habits from these representations. Thus, most individuals do not consume dairy products, bread, cereals and derivates with an appropriate eating frequency. There were also differences in eating reporting of the same foods between job strains, focusing that all of these show eating patterns that deviates from the recommendations argued by mediterranean food pyramid and wheel of foods. In the present societies, workplace appears to be obesogenic due to the changes in labour’s nature and to the conditions that this one takes place. Towards the results obtained, it was developed a social and organizational intervention which entails to promote healthy eating habits and lifestyles.

Mobilizing Greater Crop and Land Potentials Sustainably

The supply side of the food security engine is the way we farm. The current engine of conventional tillage farming is faltering and needs to be replaced. This presentation will address supply side issues of agriculture to meet future agricultural demands for food and industry using the alternate no-till Conservation Agriculture (CA) paradigm (involving no-till farming with mulch soil cover and diversified cropping) that is able to raise productivity sustainably and efficiently, reduce inputs, regenerate degraded land, minimise soil erosion, and harness the flow of ecosystem services. CA is an ecosystems approach to farming capable of enhancing not only the economic and environmental performance of crop production and land management, but also promotes a mindset change for producing ‘more from less’, the key attitude towards sustainable production intensification. CA is now spreading globally in all continents at an annual rate of 10 Mha and covers some 157 Mha of cropland. Today global agriculture produces enough food to feed three times the current population of 7.21 billion. In 1976, when the world population was 4.15 billion, world food production far exceeded the amount necessary to feed that population. However, our urban and industrialised lifestyle leads to wastage of food of some 30%-40%, as well as waste of enormous amount of energy and protein while transforming crop-based food into animal-derived food; we have a higher proportion of people than ever before who are obese; we continue to degrade our ecosystems including much of our agricultural land of which some 400 Mha is reported to be abandoned due to severe soil and land degradation; and yields of staple cereals appear to have stagnated. These are signs of unsustainability at the structural level in the society, and it is at the structural level, for both supply side and demand side, that we need transformed mind sets about production, consumption and distribution. CA not only provides the possibility of increased crop yields for the low input smallholder farmer, it also provides a pro-poor rural and agricultural development model to support agricultural intensification in an affordable manner. For the high output farmer, it offers greater efficiency (productivity) and profit, resilience and stewardship. For farming anywhere, it addresses the root causes of agricultural land degradation, sub-optimal ecological crop and land potentials or yield ceilings, and poor crop phenotypic expressions or yield gaps. As national economies expand and diversify, more people become integrated into the economy and are able to access food. However, for those whose livelihoods continue to depend on agriculture to feed themselves and the rest of the world population, the challenge is for agriculture to produce the needed food and raw material for industry with minimum harm to the environment and the society, and to produce it with maximum efficiency and resilience against abiotic and biotic stresses, including those arising from climate change. There is growing empirical and scientific evidence worldwide that the future global supplies of food and agricultural raw materials can be assured sustainably at much lower environmental and economic cost by shifting away from conventional tillage-based food and agriculture systems to no-till CA-based food and agriculture systems. To achieve this goal will require effective national and global policy and institutional support (including research and education).

Oral food perception and polyphenol-rich foods acceptance - the importance of knowing individuals saliva characteristics for promoting consumption

Polyphenols are widely present in fruits, vegetables, cereals and beverages. Their study gained scientific interest because of their beneficial effects on health. Although there is currently no official dietary recommendation for polyphenol intake, health professionals recommend the consumption of 5-8 daily portions of fruits and vegetables. This is not always achieved and, despite possible causes associated to practical schedule difficulties, the aversive bitter and astringent sensations associated to polyphenols may also lead to avoidance. As such, a better understanding on mechanisms responsible for differences among people, in polyphenol oral perception, is needed for promoting healthier choices. Saliva has been linked to polyphenol consumption. We have previously observed, in animal models, changes in salivary proteome induced by tannin-enriched diets. Moreover, differences in astringency perception were attributed to differences in salivary protein composition. In a recent experiment, we observed differences among individuals with dissimilar tannic-acid perception: people with high sensitivity for the oral sensations elicited by tannins have higher amounts of salivary cystatins and lower capacity to maintain their levels after tannic-acid ingestion. Additionally, and similarly to previous studies, salivary amylase was observed to be involved in tannin perception. In this presentation, oral cavity characteristics influencing the perception of polyphenol-containing foods will be discussed.