98 research outputs found
Limb bone scaling in hopping diprotodonts and quadrupedal artiodactyls
Bone adaptation is modulated by the timing, direction, rate, and magnitude of mechanical loads. To investigate whether frequent slow, or infrequent fast, gaits could dominate bone adaptation to load, we compared scaling of the limb bones from two mammalian herbivore clades that use radically different high-speed gaits, bipedal hopping and quadrupedal galloping. Forelimb and hindlimb bones were collected from 20 artiodactyl and 15 diprotodont species (body mass M 1.05 - 1536 kg) and scanned in clinical computed tomography or X-ray microtomography. Second moment of area (Imax) and bone length (l) were measured. Scaling relations (y = axb) were calculated for l vs M for each bone and for Imax vs M and Imax vs l for every 5% of length. Imax vs M scaling relationships were broadly similar between clades despite the diprotodont forelimb being nearly unloaded, and the hindlimb highly loaded, during bipedal hopping. Imax vs l and l vs M scaling were related to locomotor and behavioural specialisations. Low-intensity loads may be sufficient to maintain bone mass across a wide range of species. Occasional high-intensity gaits might not break through the load sensitivity saturation engendered by frequent low-intensity gaits
E-Zn inelastic scattering at 80 eV
© Published under licence by IOP Publishing Ltd. Stokes and Electron Impact Coherence Parameters (EICPs) for electronic excitation of 41P1 state of zinc atoms have been measured for incident electron energy of 80 eV. The experimental data are presented together with Convergent Close Coupling (CCC) theoretical predictions. Our results are compared with recently published Relativistic Distorted-Wave Approximation (RDWA) calculations
Limb bone scaling in hopping macropods and quadrupedal artiodactyls
Bone adaptation is modulated by the timing, direction, rate and magnitude of mechanical loads. To investigate whether frequent slow, or infrequent fast, gaits could dominate bone adaptation to load, we compared scaling of the limb bones from two mammalian herbivore clades that use radically different high-speed gaits, bipedal hopping (suborder Macropodiformes; kangaroos and kin) and quadrupedal galloping (order Artiodactyla; goats, deer and kin). Forelimb and hindlimb bones were collected from 20 artiodactyl and 15 macropod species (body mass M 1.05–1536 kg) and scanned in computed tomography or X-ray microtomography. Second moment of area (Imax) and bone length (l) were measured. Scaling relations (y = axb) were calculated for l versus M for each bone and for Imax versus M and Imax versus l for every 5% of length. Imax versus M scaling relationships were broadly similar between clades despite the macropod forelimb being nearly unloaded, and the hindlimb highly loaded, during bipedal hopping. Imax versus l and l versus M scaling were related to locomotor and behavioural specializations. Low-intensity loads may be sufficient to maintain bone mass across a wide range of species. Occasional high-intensity gaits might not break through the load sensitivity saturation engendered by frequent low-intensity gaits
Reconstruction of ovine axonal cytoarchitecture enables more accurate models of brain biomechanics
There is an increased need and focus to understand how local brain microstructure affects the transport of drug molecules directly administered to the brain tissue, for example in convection-enhanced delivery procedures. This study reports a systematic attempt to characterize the cytoarchitecture of commissural, long association and projection fibres, namely the corpus callosum, the fornix and the corona radiata, with the specific aim to map different regions of the tissue and provide essential information for the development of accurate models of brain biomechanics. Ovine samples are imaged using scanning electron microscopy combined with focused ion beam milling to generate 3D volume reconstructions of the tissue at subcellular spatial resolution. Focus is placed on the characteristic cytological feature of the white matter: the axons and their alignment in the tissue. For each tract, a 3D reconstruction of relatively large volumes, including a significant number of axons, is performed and outer axonal ellipticity, outer axonal cross-sectional area and their relative perimeter are measured. The study of well-resolved microstructural features provides useful insight into the fibrous organization of the tissue, whose micromechanical behaviour is that of a composite material presenting elliptical tortuous tubular axonal structures embedded in the extra-cellular matrix. Drug flow can be captured through microstructurally-based models using 3D volumes, either reconstructed directly from images or generated in silico using parameters extracted from the database of images, leading to a workflow to enable physically-accurate simulations of drug delivery to the targeted tissue
Addition to "Nanostars carrying multifunctional neurotrophic dendrimers protect neurons in preclinical in vitro models of neurodegenerative disorders".
In the original version of this article (p. 47457), some acknowledgments were not included. In the revised Acknowledgments section provided below, we additionally provide The REC reference for the ethical approval of the human astrocyte isolation, an acknowledgment to Dr. Alize Proust at the Francis Crick Institute for establishing the triple coculture BBB model used in this study, and the reference and the grant number for the source of the human fetal material. This does not affect the results or conclusions of our work
Analysis of the environmental adequacy and management of dejections on swine buildings in farms in the west region of the State of Paran?, Southern Brazil
Os dejetos de su?nos s?o res?duos altamente poluidores, que prejudicam o meio ambiente, em especial a qualidade da ?gua e o desenvolvimento de peixes e outros organismos aqu?ticos. Com isso, o objetivo deste trabalho foi verificar o perfil da suinocultura, a an?lise da adequa??o das instala??es, os sistemas de manejo dos dejetos, bem como a adequa??o ? legisla??o ambiental das propriedades agr?colas localizadas na microbacia do C?rrego Ajuricaba, selecionada e localizada na bacia hidrogr?fica do Rio S?o Francisco Verdadeiro, na regi?o Oeste do Paran?. Os resultados apresentados neste trabalho referem-se a dez propriedades das 110 analisadas. O perfil da suinocultura ? de 80% dos suinocultores com sistema de cria??o em termina??o e 20% em ciclo completo; nenhuma das instala??es possui o sistema de l?mina d ?gua; todas as instala??es utilizam o sistema de limpeza por raspagem; a freq??ncia de limpeza das baias nas instala??es ? di?ria e, em 90% das instala??es, n?o foi observado desperd?cio de ra??o. O principal problema detectado nas constru??es foi o acesso das ?guas da chuva nas canaletas. No aspecto da legisla??o ambiental, constatou-se que todas as propriedades da microbacia analisada possuem problemas com a mata ciliar.Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG)Empresa de Pesquisa Agropecu?ria de Minas Gerais (EPAMIG)Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)The swine dejections are polluting residues that harm the environment, in special the water quality and the development of fish and other aquatic organisms. The objective of this work was to verify the profile of the swine raise, analysis of the adequacy of the installations, the systems of the dejection handling, as well as the adequacy to the environmental legislation of the agricultural properties located in the microatchment of Ajuricaba stream, selected and located in the hydrographical basin of the S?o Francisco Verdadeiro River, in the western region of Paran?. The results presented in this work mention ten properties of 110 analyzed. The profile of the swine raise is of 80% of the swine breeder with handling system in termination and 20% in complete cycle; none of the buildings have the thin layer water system; all the installations uses the system of scraping cleanness; the frequency of the cleanness of the bay in the installations is daily; wastefulness of ration in 90% of the evaluated installations was not observed; the main problem of the installations is the access of rain water in the narrow channels and all the properties of the microatchment of the Ajuricaba stream have problems with the clear forest
Aduba??o nitrogenada na forma de cama sobreposta de su?no e seus efeitos nos atributos de um Neossolo Quartzar?nico
Objetivou-se com o presente trabalho avaliar os efeitos da aduba??o nitrogenada na forma de cama sobreposta de su?no sobre os atributos de um Neossolo Quartzar?nico. O composto org?nico utilizado foi a cama sobreposta, feita com casca-de-arroz, proveniente de uma granja comercial de su?nos em sistema de termina??o. As amostras de cama sobreposta foram retiradas em v?rios pontos da instala??o, visando a obter-se amostra composta representativa, ap?s o que foi fracionada em peneira de 2,0 mm e submetida a uma compostagem adicional de 50 dias. Na sequ?ncia, foram realizadas an?lises de valor agron?mico. O delineamento experimental foi o inteiramente casualizado. Os tratamentos constitu?ram-se das dosagens de 0; 75; 150 e 300 mg dm-3 de N na forma de cama sobreposta, bem como um tratamento adicional com sulfato de am?nio na dose de 150 mg dm-3 de N. O per?odo experimental em casa de vegeta??o foi de 45 dias, onde se cultivou o solo com milho. Finalizado o experimento, procedeu-se a nova an?lise dos atributos do solo. Pelos resultados obtidos, notou-se que a aduba??o org?nica com cama sobreposta proporcionou aumentos significativos nos teores de pot?ssio, na soma de bases, na CTC efetiva, na CTC a pH 7,0 e na porcentagem de satura??o por bases.Funda??o de Amparo ? Pesquisa do Estado de Minas Gerais (FAPEMIG)Empresa de Pesquisa Agropecu?ria de Minas Gerais (EPAMIG)Conselho Nacional de Desenvolvimento Cient?fico e Tecnol?gico (CNPq)Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES)The objective of this study was to evaluate the effects of the nitrogen fertilization in the form of swine deep bed in the properties of a quartz-sand neosol. The organic compound used was the deep bed made with rice hulls, from a commercial swine finishing system farm. Deep bed samples have been collected at various points in the installation in order to obtain a representative composite sample which has been fractionated in a 2.0 mm sieve and submitted to a 50-day maturation period. Then, agronomic value analyses were done. The experimental design was completely randomized. The treatments consisted of 0; 75; 150 and 300 mg dm-3 of N doses of deep bed as well as an additional treatment with ammonium sulfate at a 150 mg dm-3 of N. The experimental period in the greenhouse was 45 days, where the soil was cultivated with maize. After the experiment completion, further soil properties analyses were done. From the results, it was noted that the organic fertilization with deep bed provided a significant increase in the levels of potassium, in the sum of the bases, in the effective CEC, in the CEC at pH 7.0 and in the percentage of saturation
Characteristics of fine and ultrafine aerosols in the London underground
\ua9 2022 The Authors. Underground railway systems are recognised spaces of increased personal pollution exposure. We studied the number-size distribution and physico-chemical characteristics of ultrafine (PM0.1), fine (PM0.1–2.5) and coarse (PM2.5–10) particles collected on a London underground platform. Particle number concentrations gradually increased throughout the day, with a maximum concentration between 18:00 h and 21:00 h (local time). There was a maximum decrease in mass for the PM2.5, PM2.5–10 and black carbon of 3.9, 4.5 and ~ 21-times, respectively, between operable (OpHrs) and non-operable (N-OpHrs) hours. Average PM10 (52 μg m−3) and PM2.5 (34 μg m−3) concentrations over the full data showed levels above the World Health Organization Air Quality Guidelines. Respiratory deposition doses of particle number and mass concentrations were calculated and found to be two- and four-times higher during OpHrs compared with N-OpHrs, reflecting events such as train arrival/departure during OpHrs. Organic compounds were composed of aromatic hydrocarbons and polycyclic aromatic hydrocarbons (PAHs) which are known to be harmful to health. Specific ratios of PAHs were identified for underground transport that may reflect an interaction between PAHs and fine particles. Scanning transmission electron microscopy (STEM) chemical maps of fine and ultrafine fractions show they are composed of Fe and O in the form of magnetite and nanosized mixtures of metals including Cr, Al, Ni and Mn. These findings, and the low air change rate (0.17 to 0.46 h−1), highlight the need to improve the ventilation conditions
Microclima e índices de conforto térmico em sistemas de integração lavoura-pecuária-floresta no município de Campo Grande, Mato Grosso do Sul.
O objetivo deste trabalho foi avaliar índices de conforto térmico em sistemas de integração lavoura-pecuária-floresta, com eucalipto em arranjos de 14x2m (ILPF-1) e de 22x2m (ILPF-2) e árvores nativas dispersas com 5 árvores/ha-1 (ILPF-3), no Município de Campo Grande, Mato Grosso do Sul. O experimento foi conduzido na Embrapa Gado de Corte, em Campo Grande, MS, de julho a setembro de 2013. As avaliações foram realizadas mensalmente, em quatro dias consecutivos, em três horários (09h00, 12h00 e 15h00; GMT -04h00). Foram determinadas a temperatura do ar (°C), temperatura de globo negro (°C), temperatura de bulbo úmido (°C), umidade relativa do ar (%) e velocidade do vento (m s-1). Foram calculados o Índice de Temperatura e Umidade (ITU), Índice de Temperatura de Globo e Umidade (ITGU) e a Carga Térmica de Radiação (CTR). Em todos os sistemas, os maiores valores dos índices foram observados a pleno sol, às 12h00, resultando em ITU de 81 e ITGU de 88. À sombra, houve maior conforto térmico (ITU = 78 e ITGU = 79), e redução da Carga Térmica de Radiação de até 224,4 W.m-2. Conclui--se, assim, que a presença de árvores altera positivamente o ambiente e as mesmas são fundamentais para a melhoria do conforto térmico de animais criados em pastagens de regiões com clima quente.bitstream/item/158137/1/Microclima-e-indices-de-conforto.pd
The effect of extreme weather events on breeding parameters of the White Stork Ciconia ciconia
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