The conjecturing process: perspectives in theory and implications in practice

[Abstract]: In this paper we analyze different types and stages of the conjecturing process. A classification of conjectures is discussed. A variety of problems that could lead to conjectures are considered from the didactical point of view. Results from a number of research studies are used to identify and investigate a number of questions related to the theoretical background of conjecturing as well as practical implications in the learning process

Understanding the management logic of private forest owners: a new approach

Recently, several typologies of non-industrial private forest owners were established in order to assess their objectives and attitudes toward forests. However, current management practices and work organization have usually not been explicitly addressed in these empirically based typologies. In a context of increasing outsourcing and decreasing family work in forests, it is important to know the forest practices, who carries them out, and with whose labour and equipment. The interrelated knowledge of these variables sheds light on the constraints faced by different forest owners and about the agents caring for their forests. Such knowledge can also improve the understanding of forest owners' behaviour and, therefore, be useful for the design and implementation of forest policies. The work models of Portuguese non-industrial private forest were identified with these goals in mind. A cluster analysis, using a representative nationwide sample and an empirically based set of variables, was instrumental in identifying six work models. The interrelation amongst these models and other variables such as landholding attributes (e.g. forest size and dominant species), owners' social profile, and their economic goals was also assessed. Finally, the main dynamics of private owners' forest management are outlined

Disentangling the influence of environmental and anthropogenic factors on the distribution of endemic vascular plants in Sardinia

Due to the impelling urgency of plant conservation and the increasing availability of high resolution spatially interpolated (e.g. climate variables) and categorical data (e.g. land cover and vegetation type), many recent studies have examined relationships among plant species distributions and a diversified set of explanatory factors; nevertheless, global and regional patterns of endemic plant richness remain in many cases unexplained. One such pattern is the 294 endemic vascular plant taxa recorded on a 1 km resolution grid on the environmentally heterogeneous island of Sardinia. Sixteen predictors, including topographic, geological, climatic and anthropogenic factors, were used to model local (number of taxa inside each 1 km grid cell) Endemic Vascular Plant Richness (EVPR). Generalized Linear Models were used to evaluate how each factor affected the distribution of local EVPR. Significant relationships with local EVPR and topographic, geological, climatic and anthropogenic factors were found. In particular, elevation explained the larger fraction of variation in endemic richness but other environmental factors (e.g. precipitation seasonality and slope) and human-related factors (e.g. the Human Influence Index (HII) and the proportion of anthropogenic land uses) were, respectively, positively and negatively correlated with local EVPR. Regional EVPR (number of endemic taxa inside each 100 m elevation interval) was also measured to compare local and regional EVPR patterns along the elevation gradient. In contrast to local, regional EVPR tended to decrease with altitude partly due to the decreasing area covered along altitude. The contrasting results between local and regional patterns suggest that local richness increases as a result of increased interspecific aggregation along altitude, whereas regional richness may depend on the interaction between area and altitude. This suggests that the shape and magnitude of the species-area relationship might vary with elevation. This work providesâ\u80\u94for the first time in Sardiniaâ\u80\u94a comprehensive analysis of the influence of environmental factors on the pattern of EVPR in the entire territory, from sea level to the highest peaks. Elevation, as well as other environmental and human-related variables, were confirmed to be influencing factors. In addition, variations of EVPR patterns at regional-to-local spatial scales inspire next investigations on the possible interaction between elevation and area in explaining patterns of plant species richness

Promoting Landscape-Level Forest Management in Fire-Prone Areas: Delegate Management to a Multi-Owner Collaborative, Rent the Land, or Just Sell It?

Forest management at the landscape level is a requirement for reducing wildfire hazard. In contexts where non-industrial private forest ownership prevails, the collaboration among multiple owners has been proposed as the way forward to reach consistent fuel management at that level. The current literature has been focused on identifying the factors that lead to collaboration among owners. In this study we explored other ways to reach landscape-level management in addition to the collaborative way, such as those that may be promoted through land renting or selling. Different contexts and owner types may require different solutions. Thus, we explicitly asked which alternative would be chosen by a given forest owner, from the following set: keeping individual management, entering a multi-owner collaborative arrangement where they delegate management, renting to a pulp company; or selling the land. In a context of small-scale ownership and high recurrence of wildfires in Portugal, a face-to-face survey was carried out to a sample of landowners. Our results suggest that there is not an a priori generalized unwillingness of owners to delegate management, rent or sell the land and thus they seem prone to align themselves with policy strategies to promote management at the landscape level. Multinomial logit regression modelling allowed us to explain and predict owners’ choices among the aforementioned set of alternative management options. We found that choosing multi-ownership collaboration, as opposed to keeping current individual management, is associated with passive management under harsher conditions, by non-residents without bonding capital. The identified factors of owners’ choices show the limited scope of tenancy and land-market mechanisms to promote landscape-level management. The best policy option was found to depend on the owner profiles prevailing in the target area. This suggests that studying the existing context and owner types is required to design effective policiesinfo:eu-repo/semantics/publishedVersio

A farming systems approach to linking agricultural policies with biodiversity and ecosystem services

Concepts and QuestionsMany countries are reshaping their agricultural policies to better enhance biodiversity and ecosystem services (BES) in farmlands, but measuring the effectiveness of policy instruments in BES delivery is challenging. Using the European Agricultural Policy as an example, we propose the application of a farming systems (FS) approach as a cost-effective tool for linking policy design and expected BES outcomes. On the basis of available data from subsidy payment agencies, such an approach can identify groups of farms that share similar management practices as well as the associations between FS and corresponding BES potential, and improve modeled outputs of farm management responses to policies and other drivers of change. We describe how this relatively unexplored source of information can help to support applied ecological research and relevant policy, and call for these data to be made available across Europe and elsewhereN/

A short review of the distribution of short-beaked common dolphins (Delphinus delphis) in the central and eastern North Atlantic with an abundance estimate for part of this area

This paper uses data from 3 programmes: (1) the North Atlantic Sightings Surveys (NASS) surveys undertaken throughout much of the central and eastern North Atlantic north of about 40° N in 1987, 1989, 1995 and 2001; (2) the MICA-93 programme; and (3) the north eastern Atlantic segment of the Small Cetacean Abundance in the North Sea (SCANS) survey in 1994. The data from all surveys were used to examine the distribution of common dolphins in the NE Atlantic. No sightings were made north of 57° N. An initial attempt to examine distribution against 4 potential non biological explanatory variables was made. A simple interpretation of the preliminary analyses presented here is that the primary areas for groups of common dolphins were in waters over 15° C and depths of 400-1,000 m (there does appear a link with shelf features), between around 49°-55° N especially between 20°-30°W. An illustrative example of spatial modelling is presented. Only for 1 year (and part of the total survey area) were there sufficient data to attempt to estimate abundance: 1995. The estimated abundance in the W Block of the NASS-95 Faroese survey was 273,159 (cv=0.26; 95% CI=153,392-435,104) short-beaked common dolphins. This estimate is corrected for animals missed on the trackline (g(0)) and for responsive movement.Publisher PDFPeer reviewe

Vet-OncoNet: Malignancy Analysis of Neoplasms in Dogs and Cats

Analysis of canine and feline tumor malignancy data can help clinicians identify high-risk patients and make more accurate decisions. Based on a sample of 16,272 cancer records, including 3266 cats and 13,006 dogs, collected from January 2019 to December 2021 in the Vet-OncoNet Network database, this study aimed to compare the tumor malignancy profile between cats and dogs, considering animal-related factors (sex, age, and breed), topography, and geographic location using a mixed-effects logistic regression model. Cats had a higher proportion of malignant tumors (78.7%) than dogs (46.2%), and the malignancy profile was very different regarding tumors’ topographies.The mean age of malignant tumors occurred eight months later than benign ones (9.1, SD = 3.4; 9.8,SD = 3.2), in general. Species (OR = 3.96, 95%CI 3.57: 4.39) and topography (MOR = 4.10) were the two most important determinants of malignancy risk. Female dogs had a higher risk than male dogs (OR = 1.19, 95%CI 1.08: 1.31), which does not appear to be the case in cats (OR = 0.98, 95%CI0.77: 1.23). Breed contributed significantly to differences in malignancy risk in dogs (MOR = 1.56), particularly in pit bulls and boxers. District of residence was not so relevant in predicting malignancy risk (MOR = 1.14). In both species, the risk of malignancy increased by approximately 20% every three years. It could be hypothesized that species differences in genetic structure may contribute to tumor malignancy

Assessment of social and economic influences on blood pressure of adolescents in public and private schools: an epidemiological study

INTRODUCTION: The high prevalence of hypertension in high school students in Sorocaba, São Paulo, Brazil, has already been described. In this study, within a new sample of high school students from public and private schools, we evaluated if socioeconomic and lifestyle influence on blood pressure values. METHODS: This is an epidemiological study, which is part of the activities of a community-based work conducted by medical students. They give speeches to high school students aiming at stimulating a healthy lifestyle and primary prevention of hypertension. In a random sample of 410 students in junior high school (209 from public schools and 201 from private schools), we determined the weight, height, and blood pressure, furthermore, a questionnaire identifying epidemiological and socioeconomic status was applied. RESULTS: No statistical differences were found among students from public and private schools regarding the distribution of gender, body mass index (BMI), systolic and diastolic blood pressure, prevalence of hypertension (16.3%), percentage of smokers (5.9%), regular physical activity, and family history of hypertension. In public schools, there is a higher percentage of African descendents students and a higher percentage of students who also work due to low family income. Men from public and private schools have higher prevalence of hypertension, and their mean blood pressure is higher than in women. BMI has a positive correlation with systolic and diastolic blood pressure. CONCLUSIONS: Hypertension and other cardiovascular risk factors have an early beginning and require educational interventions for primary prevention. Socioeconomic factors do not affect blood pressure in adolescence.INTRODUÇÃO: Anteriormente, a alta prevalência de hipertensão arterial em alunos do Ensino Médio de Sorocaba, em São Paulo, foi descrita. Neste estudo, em nova amostra de alunos da mesma faixa etária, oriundos de escolas públicas e privadas, foi avaliado se as diferenças socioeconômicas e o modo de vida podem influenciar os valores da pressão arterial. MÉTODOS: Trata-se de um estudo epidemiológico, inserido entre as atividades de um trabalho comunitário, em que estudantes de Medicina fazem palestras para alunos do Ensino Médio, objetivando estimular hábitos de vida saudáveis e a prevenção primária da hipertensão arterial. Em amostra aleatória de 410 alunos do segundo ano do Ensino Médio (209 de escolas públicas e 201 de escolas privadas), foram determinados o peso, a altura e a pressão arterial, e foi aplicado um questionário epidemiológico e socioeconômico. RESULTADOS: Não há diferenças estatísticas entre os alunos das escolas públicas e privadas quanto à distribuição de sexo, ao índice de massa corporal (IMC), à pressão arterial sistólica e diastólica, à prevalência de hipertensão arterial (16,3%), à porcentagem de fumantes (5,9%), à atividade física regular e aos antecedentes familiares de hipertensão arterial. Nas escolas públicas há maior porcentagem de afro-descendentes, os alunos trabalham fora de casa com maior frequência e têm menor renda familiar. Nas escolas públicas e privadas, os homens têm maior prevalência de hipertensão arterial e a média da pressão arterial é maior que nas mulheres. O IMC tem correlação positiva com a pressão arterial sistólica e diastólica. CONCLUSÕES: A hipertensão arterial e outros fatores de risco cardiovasculares têm início precoce e necessitam de intervenções educativas para a prevenção primária. Fatores socioeconômicos não influenciam a pressão arterial na adolescência.Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Cornell University Medical CollegePontifícia Universidade Católica de São Paulo Faculdade de Ciências Médicas e da SaúdeUniversidade Federal de São Paulo (UNIFESP)UNIFESPSciEL

Tratamento medicamentoso dos tumores hipofisários. Parte II : adenomas secretores de ACTH, TSH e adenomas clinicamente não-funcionantes

Este artigo revisa o potencial papel do tratamento medicamentoso para os adenomas hipofisários secretores de ACTH, TSH e aqueles clinicamente não-funcionantes (ACNF), Metirapona, mitotano e cetoconazol (preferível por causar menos efeitos colaterais) são as drogas mais eficazes no controle do hipercortisolismo, mas nenhuma delas supera a eficácia da cirurgia transesfenoidal (TSA). O tratamento medicamentoso da doença de Cushing está, portanto, melhor indicado para pacientes aguardando o efeito pleno da radioterapia ou, como alternativa para esta última, em casos de hipercortisolismo persistente após TSA, e para pacientes com rejeição ou limitações clínicas para a cirurgia. Outra indicação potencial seria em idosos com microadenomas ou pequenos macroadenomas, ou em casos associados a sela vazia. No que se refere aos adenomas secretores de TSH, os análogos somatostatínicos (SRIFa) proporcionam normalização dos hormônios tiroideanos em até 95% dos casos. Assim, eles podem se mostrar úteis em casos de insucesso da cirurgia ou como terapia primária de casos selecionados. Ocasionalmente, agonistas dopaminérgicos (DA), sobretudo a cabergolina, também podem ser eficazes. Em contraste, DA e SRIFa raramente induzem uma significante redução das dimensões dos ACNFs. Por isso, em pacientes com tais tumores, essas drogas devem ser principalmente consideradas diante de contra-indicações ou limitações clínicas para a cirurgia ou quando a cirurgia e a radioterapia tenham sido mal-sucedidas.This article reviews the potencial role of medical treatment for both ACTH and TSH secreting pituitary adenomas, as well as for clinically non-functionning pituitary adenomas (CNFPA). Metyrapone, mitotane and ketoconazole (preferable for causing less side-effects) are the most effective drugs for the control of hypercortisolism but none of them surpasses the efficacy of transsphenoidal surgery (TSA). Drug therapy in Cushing's disease is therefore better indicated for patients waiting for the full effect of radiotherapy or, as an alternative to radiotherapy, for cases of TSA failure as well as patients that refuse or have clinical limitations to surgery. Other potential indications for medical treatment in Cushing's disease include elderly patients with microadenomas or small macroadenomas, as well as cases associated to an empty sella. Concerning TSH-secreting adenomas, somatostatin analogues (SRIFa) lead to normalization of thyroid hormones in up to 95% of treated patients. Therefore they may represent an useful tool for long-term treatment of such rare tumors in case of surgery failure or as primary therapy for selected cases. Occasionaly, dopamine agonists (DA), especially cabergoline, may also be efficacious in normalizing hormone levels. In contrast, DA and SRIFa rarely induce significant tumor shrinkage in patients with CNFPA. Thus, these drugs should be considered particularly for patients who are poor candidates for surgery or in whom surgery and radiotherapy have failed to control the disease