241 research outputs found
Biomassa e estoques de nutrientes em vegetação de pousio sob diferentes manejos em sistema agroflorestal seqüencial de corte-e-trituração na Amazônia Oriental.
O manejo da vegetação de pousio é importante para manutenção da produtividade em sistemas agroflorestais seqüenciais. Durante o período de pousio, o sistema acumula nutrientes para as culturas agrícolas subseqüentes. A introdução de espécies leguminosas associadas à adubação fosfatada de baixa solubilidade pode promover o acúmulo de biomassa e os estoques de nutrientes influenciando positivamente na produtividade das culturas agrícolas. O estudo da biomassa e dos estoques de nutrientes nesses agroecossistemas pode fornecer subsídios para o seu manejo. Este artigo compara estimativas da biomassa e estoques de nutrientes de três vegetações de pousio submetidos a diferentes tratamentos: (1) pousio espontâneo; (2) pousio enriquecido com leguminosas arbóreas (Sclerolobium paniculatum Vogel e Inga edulis Mart.), e (3) pousio enriquecido com leguminosas arbóreas submetidas à adubação fosfatada de baixa solubilidade. O experimento foi conduzido por 23 meses, em um sistema agroflorestal seqüencial de corte-e-trituração no município de Marapanim, Amazônia Oriental. Os resultados mostraram que o sistema de pousio enriquecido com leguminosas arbóreas, submetidas ou não à adubação fosfatada de baixa solubilidade, acumula maiores massas secas e estoques de nutrientes que o sistema com pousio espontâneoEditores técnicos: Roberto Porro, Milton Kanashiro, Maria do Socorro Gonçalves Ferreira, Leila Sobral Sampaio e Gladys Ferreira de Sousa
Changing depositional environments in an Upper Ordovician stratigraphic sequence, Ashlock Formation, Madison County, Kentucky
We investigate the sedimentology, stratigraphy, and depositional environments of a 7-meter, Upper Ordovician limestone sequence cropping out in Richmond, Madison County, Kentucky. The stratigraphic section lies within the Ashlock Formation with good lateral exposure stretching along 200 meters of a highway roadcut. We took approximately 20 samples from the measured section, focusing on representative samples and lithologic transitions. We use standard laboratory procedures in slabbing rock samples and making thin sections.
The Ashlock Formation here consists of alternating layers of limey mudstone and limestone (field units A through F). Megafossils - brachiopods, bryozoans, trilobites, gastropods, ostracodes, coralline algae, and bivalves - are abundant in limestone units. These observations are consistent with depositional environments representing marine, shallow-water deposits. The contact between units F and G contains beads of weathered pyrite perhaps representing an omission surface. Field units G through J contain more terrigeneous mud. The observed transition from limestones to lithologies with more terrigenous mud suggests any combination of: (1) increase in water depth; (2) climatic change resulting in more runoff; or (3) tectonic activity delivering more mud to the basin. The stratigraphic section is capped by fossiliferous limestone (unit K), which again represents shallow, marine conditions without terrigenous input
Changing Depositional Environments in an Upper Ordovician Stratigraphic Sequence, Ashlock Formation, Madison County, Kentucky
We investigate the sedimentology, stratigraphy, and depositional environments of a 7-meter, Upper Ordovician limestone sequence cropping out in Richmond, Kentucky. The stratigraphic section lies within the Ashlock Formation with good lateral exposure stretching along 200 meters of a highway roadcut. We took approximately 20 samples from the measured section, focusing on representative samples and lithologic transitions. We use standard laboratory procedures in slabbing rock samples and making thin sections.
The Ashlock Formation at this locality consists of alternating layers of limey mudstone and limestone. Megafossils - brachiopods, bryozoans, trilobites, gastropods, ostracodes, coralline algae, and bivalves - are abundant in various limestone units. The observed transitions from limestones and limy muds to lithologies with more terrigenous mud suggests any combination of: (1) migration of depositional environment with a slight increase in water depth; (2) climatic change resulting in more runoff; or (3) tectonic activity delivering more mud to the basin. These shallow water environments change to glauconitic mudstone and laminated shales, which we interpret as deeper shelf deposits. The measured section is capped by shaley limestones and mudstones that signal a return to shallow subtidal environments
Changing depositional environments in an Upper Ordovician stratigraphic sequence, Ashlock Formation, Madison County, Kentucky
We investigate the sedimentology, stratigraphy, and depositional environments of a 7-meter, Upper Ordovician limestone sequence cropping out in Richmond, Kentucky. The stratigraphic section lies within the Ashlock Formation with good lateral exposure stretching along 200 meters of a highway roadcut. We took approximately 20 samples from the measured section, focusing on representative samples and lithologic transitions. We use standard laboratory procedures in slabbing rock samples and making thin sections.
The Ashlock Formation at this locality consists of alternating layers of limey mudstone and limestone. Megafossils - brachiopods, bryozoans, trilobites, gastropods, ostracodes, coralline algae, and bivalves - are abundant in various limestone units. The observed transitions from limestones and limy muds to lithologies with more terrigenous mud suggests any combination of: (1) migration of depositional environment with a slight increase in water depth; (2) climatic change resulting in more runoff; or (3) tectonic activity delivering more mud to the basin. These shallow water environments change to glauconitic mudstone and laminated shales, which we interpret as deeper shelf deposits. The measured section is capped by shaley limestones and mudstones that signal a return to shallow subtidal environments
The interaction between the proliferating macroalga Asparagopsis taxiformis and the coral Astroides calycularis induces changes in microbiome and metabolomic fingerprints
Mediterranean Sea ecosystems are considered as hotspots of biological introductions, exposed to possible negative effects of non-indigenous species. In such temperate marine ecosystems, macroalgae may be dominant, with a great percentage of their diversity represented by introduced species. Their interaction with temperate indigenous benthic organisms have been poorly investigated. To provide new insights, we performed an experimental study on the interaction between the introduced proliferative red alga Asparagopsis taxiformis and the indigenous Mediterranean coral Astroides calycularis. The biological response measurements included meta-barcoding of the associated microbial communities and metabolomic fingerprinting of both species. Significant changes were detected among both associated microbial communities, the interspecific differences decreasing with stronger host interaction. No short term effects of the macroalga on the coral health, neither on its polyp activity or its metabolism, were detected. In contrast, the contact interaction with the coral induced a change in the macroalgal metabolomic fingerprint with a significant increase of its bioactivity against the marine bacteria Aliivibrio fischeri. This induction was related to the expression of bioactive metabolites located on the macroalgal surface, a phenomenon which might represent an immediate defensive response of the macroalga or an allelopathic offense against coral.ERA-NET Biome project "SEAPROLIF"; CNRS; Provence Alpes Cote d'Azur Region; TOTAL Fundation; Fundacao para a Ciencia e a Tecnologia (FCT) [Netbiome/0002/2011]; FCT fellowships [SFRH/BPD/63703/2009, SFRH/BPD/107878/2015]info:eu-repo/semantics/publishedVersio
Sensitivity of Slot-Based Object-Centric Models to their Number of Slots
Self-supervised methods for learning object-centric representations have
recently been applied successfully to various datasets. This progress is
largely fueled by slot-based methods, whose ability to cluster visual scenes
into meaningful objects holds great promise for compositional generalization
and downstream learning. In these methods, the number of slots (clusters)
is typically chosen to match the number of ground-truth objects in the data,
even though this quantity is unknown in real-world settings. Indeed, the
sensitivity of slot-based methods to , and how this affects their learned
correspondence to objects in the data has largely been ignored in the
literature. In this work, we address this issue through a systematic study of
slot-based methods. We propose using analogs to precision and recall based on
the Adjusted Rand Index to accurately quantify model behavior over a large
range of . We find that, especially during training, incorrect choices of
do not yield the desired object decomposition and, in fact, cause
substantial oversegmentation or merging of separate objects
(undersegmentation). We demonstrate that the choice of the objective function
and incorporating instance-level annotations can moderately mitigate this
behavior while still falling short of fully resolving this issue. Indeed, we
show how this issue persists across multiple methods and datasets and stress
its importance for future slot-based models
DyST: Towards Dynamic Neural Scene Representations on Real-World Videos
Visual understanding of the world goes beyond the semantics and flat
structure of individual images. In this work, we aim to capture both the 3D
structure and dynamics of real-world scenes from monocular real-world videos.
Our Dynamic Scene Transformer (DyST) model leverages recent work in neural
scene representation to learn a latent decomposition of monocular real-world
videos into scene content, per-view scene dynamics, and camera pose. This
separation is achieved through a novel co-training scheme on monocular videos
and our new synthetic dataset DySO. DyST learns tangible latent representations
for dynamic scenes that enable view generation with separate control over the
camera and the content of the scene.Comment: Project website: https://dyst-paper.github.io
Working with argan cake: a new etiology for hypersensitivity pneumonitis
International audienceAbstractBackgroundArgan is now used worldwide in numerous cosmetic products. Nine workers from a cosmetic factory were examined in our occupational medicine department, following the diagnosis of a case of hypersensitivity pneumonitis (HP) related to handling of argan cakes.MethodsOperators were exposed to three forms of argan (crude granulates, powder or liquid) depending on the step of the process. All workers systematically completed standardized questionnaires on occupational and medical history, followed by medical investigations, comprising, in particular, physical examination and chest X-rays, total IgE and a systematic screening for specific serum antibodies directed against the usual microbial agents of domestic and farmer’s HP and antigens derived from microbiological culture and extracts of various argan products. Subjects with episodes of flu-like syndrome several hours after handling argan cakes, were submitted to a one-hour challenge to argan cakes followed by physical examination, determination of Carbon Monoxide Diffusing Capacity (DLCO) and chest CT-scan on day 2, and, when necessary, bronchoalveolar lavage on day 4.ResultsSix of the nine workers experienced flu-like symptoms within 8 hours after argan handling. After challenge, two subjects presented a significant decrease of DLCO and alveolitis with mild lymphocytosis, and one presented ground glass opacities. These two patients and another patient presented significant arcs to both granulates and non-sterile powder. No reactivity was observed to sterile argan finished product, antigens derived from argan cultures (various species of Bacillus) and Streptomyces marokkonensis (reported in the literature to contaminate argan roots).ConclusionsWe report the first evidence of hypersensitivity pneumonitis related to argan powder in two patients. This implies preventive measures to reduce their exposure and clinical survey to diagnose early symptoms. As exposure routes are different and antibodies were observed against argan powder and not the sterile form, consumers using argan-based cosmetics should not be concerned
Thermoelectric Characterization of IGBT Power Modules: An Approach by Static and Dynamic Methods
This study evaluates IGBT modules with a focus on efficiently measuring their thermal impedance, a critical factor in reliability assessments. The research employs the Thermo Electric Sensitive Parameter method to measure the Virtual Junction Temperature and obtain the Thermal Impedance curve. These experimental results are compared with datasheet values, using power modules without a baseplate. Two methodologies, dynamic and static, are utilized, both demonstrating consistent performance in evaluating thermal characteristics. The study also addresses the importance of accounting for non-linearity in thermal conductance due to temperature dependency, which is essential for accurate thermal characterization. Additionally, it explores the potential for measuring the Thermal Impedance between Junction and Case in power modules without a baseplate, offering a comprehensive understanding of thermal performance
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