Space tether systems uniform rotations of a Dumbbell-like System

In this dissertation, a dumbbell-like system is analyzed, considering two mass points connected by a massless and rigid tether with variable length; its center of mass moves along an elliptic Keplerian orbit. This kind of a system, in a certain type of configurations, is a simple conceptualization of a space elevator. The system motion is obtained using the Lagrangian formulation in a central gravitational field. The laws of control are considered for the system’s rotation around its center of mass; those include the uniform rotations or permanent orientation with respect to the local vertical. The stability conditions are obtained for the first case, analyzing the equation in variations and using the Floquet theory. The results show that there are regions of eccentricities where stability is found. Lastly, a dynamic numerical simulator is created, where the implementation of the results can be tested.Nesta dissertação, um sistema tipo halteres é analisado, considerando dois pontos de massa conectados com um cabo rígido, sem massa e com variações do comprimento, e com o centro de massa movendo-se segundo uma órbita Kepleriana. Este tipo de sistema, num certo tipo de configuração, é uma simples conceptualização do elevador espacial. O movimento do sistema é obtido com recurso à Formulação Lagrangiana num Campo Gravitacional Central. As leis de controlo são consideradas para uma rotação do sistema à volta do seu centro de massa. Essas incluem rotações uniformes e uma orientação permanente. As condições de estabilidade para o primeiro caso foram obtidas, analisando a respectiva equação em variações e utilizando a Teoria de Floquet. Os resultados mostraram que existem intervalos dos valores de excentricidade onde a estabilidade é encontrada. Por último, um simulador numérico e dinâmico foi criado, para se testar a implementação destes resultados

A Geo-historical Analysis of Expanding Soybean Frontiers in the Brazilian Cerrado

Until the 1970s, the Brazilian Cerrado was considered an unsuitable agricultural territory. Logistic and infrastructural issues, combined with soil acidity, made the Cerrado a marginal biome for crop production. However, since the Brazilian Agricultural Research Corporation (Embrapa) was created in 1973, the Cerrado has become a national and international hotspot for the food industry. Such a transformation turned this savannah biome into a landmark for the tropical expansion of commodity frontiers, especially in soy production. This research seeks to analyze data on the historical development of soy production volumes and productivity in the Cerrado, considering the complex interrelations between commodity frontier dynamics and its interface within different Brazilian biomes. Comparing data from the Cerrado and other biomes, our results indicate a rapid expansion of the soybean frontier in most Brazilian biogeographic regions. Moreover, it demonstrates how the growth of soy farming in the Brazilian Cerrado is also affecting other biomes such as the Amazon, influencing local and national policies of agrarian expansion and environmental conservation.Until the 1970s, the Brazilian Cerrado was considered an unsuitable agricultural territory. Logistic and infrastructural issues, combined with soil acidity, made the Cerrado a marginal biome for crop production. However, since the Brazilian Agricultural Research Corporation (Embrapa) was created in 1973, the Cerrado has become a national and international hotspot for the food industry. Such a transformation turned this savannah biome into a landmark for the tropical expansion of commodity frontiers, especially in soy production. This research seeks to analyze data on the historical development of soy production volumes and productivity in the Cerrado, considering the complex interrelations between commodity frontier dynamics and its interface within different Brazilian biomes. Comparing data from the Cerrado and other biomes, our results indicate a rapid expansion of the soybean frontier in most Brazilian biogeographic regions. Moreover, it demonstrates how the growth of soy farming in the Brazilian Cerrado is also affecting other biomes such as the Amazon, influencing local and national policies of agrarian expansion and environmental conservation.Until the 1970s, the Brazilian Cerrado was considered an unsuitable agricultural territory. Logistic and infrastructural issues, combined with soil acidity, made the Cerrado a marginal biome for crop production. However, since the Brazilian Agricultural Research Corporation (Embrapa) was created in 1973, the Cerrado has become a national and international hotspot for the food industry. Such a transformation turned this savannah biome into a landmark for the tropical expansion of commodity frontiers, especially in soy production. This research seeks to analyze data on the historical development of soy production volumes and productivity in the Cerrado, considering the complex interrelations between commodity frontier dynamics and its interface within different Brazilian biomes. Comparing data from the Cerrado and other biomes, our results indicate a rapid expansion of the soybean frontier in most Brazilian biogeographic regions. Moreover, it demonstrates how the growth of soy farming in the Brazilian Cerrado is also affecting other biomes such as the Amazon, influencing local and national policies of agrarian expansion and environmental conservation

EXPERIENCE OF THE MATERNAL WEANING PROCESS AMONG PRIMIPAROUS WOMEN: QUALITATIVE STUDY

Objective: To understand the experience of the weaning process for primiparous mothers in a municipality in the interior of Ceará, Brazil.Method: Using semi-structured interviews, a descriptive, qualitative study was conducted with eight women. Data collection from August 2022 to March 2023 in Primary Health Care, using Bardin's content analysis.Results: three thematic categories emerged: reasons for the mother's decision to wean, strategies employed by the mother to wean, and the consequences of weaning for the mother and child. Maternal perceptions of the motivation for weaning were related to behavioral aspects of the child and maternal needs. Various strategies were classified as gradual or abrupt weaning, which generated changes in the children's behavior and contradictory feelings in the mothers.Final considerations: weaning is experienced unpleasantly, generating suffering. It reveals the lack of professional assistance and the need to expand studies

Exposição Acidental a Picada de Agulha. Protocolo de Actuação

A picada acidental por agulha em crianças e adolescentes provoca grande ansiedade aos pais e é causa de recurso aos serviços de urgência.A exposição acidental inclui a picada por agulha de seringa encontrada na comunidade. O risco de transmissão do vírus da hepatite B (VHB), C (VHC), vírus da imunodeficiência humana (VIH) e outros agentes é habitualmente baixo, no entanto é da responsabilidade do clínico informar e minimizar a possibilidade de ocorrer doença.As recomendações atuais referentes à profilaxia em crianças são baseadas no risco de transmissão e seroconversão após exposição ocupacional em adultos. No entanto, e apesar da escassez de dados, a exposição acidental a picada de agulha na idade pediátrica merece uma avaliação particular.Com o objetivo de definir uma política comum a todos os hospitais e garantir acesso a cuidados mais adequados a todas as crianças, os autores apresentam um protocolo de profilaxia após exposição acidental a picada de agulha em idade pediátrica

Modelling the habitat preferences of the NE-Atlantic Sea cucumber Holothuria forskali : demographics and abundance

This work was funded by the Operational Program Mar2020 MAR-02.01.01-FEAMP-0052 “Newcumber - Avanços para o cultivo sustentável de pepinos do mar”. This work was also supported by national funds through FCT - Fundação para a Ciência e a Tecnologia, I.P., within the scope of the projects (https://doi.org/10.54499/UIDB/04292/2020, and https://doi.org/10.54499/UIDB/00006/2020) and the Associate Laboratory ARNET (https://doi.org/10.54499/LA/P/0069/2020), A.C. Brito with the Scientific Stimulus Program – CEECIND/00095/2017, A.P. with the under the Scientific Employment Stimulus - Institutional Call - CEECINST/00051/2018 and Francisco Azevedo e Silva and João Trigo de Sousa through the individual grants (SFRH/BD/09563/2020 and SFRH/BDANA/02949/2023).Sea cucumbers' historical demand, together with the depletion of several traditional species in the market, has popularized new target species from new fishing grounds. Holothuria forskali is one of those emergent species in the trade market. However, it is a species for which there is no relevant information to allow sustainable stock management. Fundamental knowledge of the populations' structure and habitat preferences are key elements without which any measure is inconsequent. This work aims to fill that gap by modelling temporal and spatial patterns of abundance and demographic structure of this species in a NE-Atlantic area, as a function of environmental features. For a period of 15 months, nine regular sampling campaigns collected data on density, individual length, individual conditions of occurrence (e.g. sheltered, on sand, on algae cover) and environmental parameters (water column, sediment, substrate cover and type), using random transects throughout a costal rocky-reef, considering habitat heterogeneity and substrate types. To determine the species' habitat preferences Generalized Linear Models were used to model density and demographic structure of the species as a function of environmental conditions. The models revealed that the main drivers shaping the distribution of H. forskali are neither abiotic nor biotic parameters of the water column, but physical stressors, like current intensity and depth, and substrate type in a patchy distribution pattern. Estuarine conditions are generally avoided, although with a size-dependent opportunistic strategy. Larger individuals show temporal and spatial displacement patterns towards suitable reproductive conditions (pre-breeding aggregation) and favourable feeding grounds and smaller size-classes tend to aggregate in higher numbers in more stable environments. Sustainable sources for market supply, like aquaculture, are still a long way from commercial production. So, these results are fundamental to support effective conservation measures for stock management of H. forskaliPublisher PDFPeer reviewe

Allometric relationships to assess ontogenetic adaptative changes in three NE Atlantic commercial sea cucumbers (Echinodermata, Holothuroidea)

This study was financed by the Operational Program Mar2020 nº MAR-02.01.01-FEAMP-0052 “Newcumber—Avanços para o cultivo sustentável de pepinos-do-mar”. It received further financial support from Fundação para a Ciência e a Tecnologia with project UIDB/04292/2020; A.C. Brito and A. Pombo through the Scientific Employment Stimulus Programmes (CEECIND/00095/2017 and CEECINST/00051/2018); and Francisco Azevedo e Silva through the individual research Grant 2020.09563.BD; Also, T. A. Marques and C. Rocha thank partial support by CEAUL (funded by FCT—Fundação para a Ciência e a Tecnologia, Portugal, through the project UIDB/00006/2020).Holothuria arguinensis, Holothuria mammata and Holothuria forskali are three common sea cucumber species found in the NE Atlantic, traded in international markets and susceptible to capture. Allometric relationships reveal if the scaling relationships between biometric characters are proportional with growth, being a useful tool to understand species growth strategies. Allometric relationships of the three species were estimated and compared between them and with populations from different regions. These allometric relationships revealed that the three species have negative allometric growth. However, they have different growth strategies between them and reveal different regional intra-specific growth strategies when compared to other populations, suggesting ontogenetic adaptation as a consequence of external factors. PostprintPeer reviewe

An integer programming approach for sensor location in a forest fire monitoring system

Forests worldwide have been devastated by fires. Forest fires cause incalculable damage to fauna and flora. In addition, a forest fire can lead to the death of people and financial damage in general, among other problems. To avoid wildfire catastrophes is fundamental to detect fire ignitions in the early stages, which can be achieved by monitoring ignitions through sensors. This work presents an integer programming approach to decide where to locate such sensors to maximize the coverage provided by them, taking into account different types of sensors, fire hazards, and technological and budget constraints. We tested the proposed approach in a real-world forest with around 7500 locations to be covered and about 1500 potential locations for sensors, showing that it allows obtaining optimal solutions in less than 20 min.This work has been supported by FCT Fundação para a Ciência e Tecnologia within the R&D Units Project Scope UIDB/00319/2020 and within project PCIF/GRF/0141/2019 “O3F - An Optimization Framework to reduce Forest Fire” and also the project UIDB/05757/2020 and Forest Alert Monitoring System (SAFe) Project through PROMOVE - Funda¸c˜ao La Caixa. Beatriz Flamia Azevedo is supported by FCT Grant Reference SFRH/BD/07427/2021, Thadeu Brito was supported by FCT PhD grant SFRH/BD/08598/2020

Grau de acamamento e tipo de porte de linhagens de feijão-caupi do grupo ereto e semi-ereto, no Norte de Minas Gerais.

Objetivou-se avaliar o grau de acamamento e o tipo de porte de linhagens de feijão-caupi de porte ereto e semi-ereto, nas condições de cultivo do Norte de Minas Gerais. O experimento foi composto por 20 tratamentos, referentes a dezesseis linhagens selecionadas no Ensaio Preliminar de Rendimento conduzido pela Embrapa Meio Norte, mais quatro cultivares comerciais, que juntas compõem o ensaio de Valor de Cultivo e Uso (VCU) de porte ereto e semi-ereto. O experimento foi conduzido na Fazenda Experimental da UNIMONTES, em Janaúba-MG. As parcelas foram compostas por quatro fileiras de plantas espaçadas de 0,5 m entre si, com cerca de 10 plantas por metro. As avaliações para classificação do grau de acamamento e do tipo de porte foram realizadas na fase de maturação de vagens, com base em escalas de notas visuais pré-determinadasAs avaliações de porte e acamamento ocorreram quando as vagens atingiram a maturidade, avaliando-se todas as plantas da parcela por meio de uma escala de notas visuais de 1 a 5. Os dados obtidos foram submetidos à análise de variância, sendo os efeitos das linhagens estudados por meio do teste de Scott-knott a 5 % de significância. As linhagens MNCO3-737F-5-9, MNCO3-737F-5-10, MNCO-737F-5-1, MNCO3-737F-5-4, MNCO2-682F-2-6, MNCO2-675F-9-2 e MNCO2-684F-5-6 apresentam menor grau de acamamento, não diferenciando-se estatisticamente das cultivares comerciais BRS-CAUAMÉ e BRS-ITAIM, nas condições de cultivo do Norte de Minas Gerais. Em relação ao porte das plantas, não houve efeito significativo de linhagens e cultivares.CONAC 2012. Disponível em: http://www.conac2012.org/resumos/pdf/138c.pdf. Acesso em: 23 jul. 2013