1,077 research outputs found
Spectral Target Detecting Using Schroedinger Eigenmaps
Applications of optical remote sensing processes include environmental monitoring, military monitoring, meteorology, mapping, surveillance, etc. Many of these tasks include the detection of specific objects or materials, usually few or small, which are surrounded by other materials that clutter the scene and hide the relevant information. This target detection process has been boosted lately by the use of hyperspectral imagery (HSI) since its high spectral dimension provides more detailed spectral information that is desirable in data exploitation. Typical spectral target detectors rely on statistical or geometric models to characterize the spectral variability of the data. However, in many cases these parametric models do not fit well HSI data that impacts the detection performance.
On the other hand, non-linear transformation methods, mainly based on manifold learning algorithms, have shown a potential use in HSI transformation, dimensionality reduction and classification. In target detection, non-linear transformation algorithms are used as preprocessing techniques that transform the data to a more suitable lower dimensional space, where the statistical or geometric detectors are applied. One of these non-linear manifold methods is the Schroedinger Eigenmaps (SE) algorithm that has been introduced as a technique for semi-supervised classification. The core tool of the SE algorithm is the Schroedinger operator that includes a potential term that encodes prior information about the materials present in a scene, and enables the embedding to be steered in some convenient directions in order to cluster similar pixels together.
A completely novel target detection methodology based on SE algorithm is proposed for the first time in this thesis. The proposed methodology does not just include the transformation of the data to a lower dimensional space but also includes the definition of a detector that capitalizes on the theory behind SE. The fact that target pixels and those similar pixels are clustered in a predictable region of the low-dimensional representation is used to define a decision rule that allows one to identify target pixels over the rest of pixels in a given image. In addition, a knowledge propagation scheme is used to combine spectral and spatial information as a means to propagate the \potential constraints to nearby points. The propagation scheme is introduced to reinforce weak connections and improve the separability between most of the target pixels and the background. Experiments using different HSI data sets are carried out in order to test the proposed methodology. The assessment is performed from a quantitative and qualitative point of view, and by comparing the SE-based methodology against two other detection methodologies that use linear/non-linear algorithms as transformations and the well-known Adaptive Coherence/Cosine Estimator (ACE) detector. Overall results show that the SE-based detector outperforms the other two detection methodologies, which indicates the usefulness of the SE transformation in spectral target detection problems
Relationship of Knowledge on Healthy Lifestyle to Dietary Practices and Physical Activity as Moderated by Age
Lifestyle – related diseases remained to be on the top ten killer according to the World HealthOrganization. Literature indicates that diseases are highly related to lifestyle practices. Onthe other hand, optimal health is a perceived goal of the greater population, however, puttingit into practice is a challenge. The study determined the following: 1) the level of knowledgeon healthy lifestyle, dietary practices and physical activity; 2) the relationship of knowledgeon healthy lifestyle to dietary practices and physical activities, and 3) the relationship ofknowledge to dietary practice and relationship of knowledge to physical activities accordingto age group. A Descriptive-correlational design was employed. The data were gatheredamong 66 randomly selected university students staying in the dormitories; who are at least18 years of age, in which 24 are males and 42 are females, and 40 have earned at most abachelor’s degree and 26 have at least earned units in a master’s program. Utilizing adaptedinstruments, respondents were scored on a 12-item instrument in knowledge where in eachcorrect answer correspond to one point, 27-item instrument on healthy lifestyle in terms ofdiet where in each appropriate response correspond to one point, and 4-item instrument onhealthy lifestyle in terms of physical activities. In turn, the highest possible score ofknowledge, diet, and physical activities are 12, 27, and 4, respectively. Descriptive resultsrevealed that respondents have high knowledge on healthy lifestyle, have fair dietarypractices and moderate practice of physical activities. Furthermore, knowledge on healthylifestyle is not significantly correlated to dietary practices physical activities. However, asignificant relationship was found when respondents were grouped according to age; onlythose 24 years old and above were found to have significant results. Hence, arecommendation to increase the accessibility and reinforcement values of exercise andphysical activity that will have immediate and long term health benefits for college students
Relationship of Knowledge on Healthy Lifestyle to Dietary Practices and Physical Activity as Moderated by Age
Lifestyle – related diseases remained to be on the top ten killer according to the World HealthOrganization. Literature indicates that diseases are highly related to lifestyle practices. On theother hand, optimal health is a perceived goal of the greater population, however, putting it intopractice is a challenge. The study determined the following: 1) the level of knowledge onhealthy lifestyle, dietary practices and physical activity; 2) the relationship of knowledge onhealthy lifestyle to dietary practices and physical activities, and 3) the relationship ofknowledge to dietary practice and relationship of knowledge to physical activities according toage group. A Descriptive-correlational design was employed. The data were gathered among66 randomly selected university students staying in the dormitories; who are at least 18 yearsof age, in which 24 are males and 42 are females, and 40 have earned at most a bachelor’sdegree and 26 have at least earned units in a master’s program. Utilizing adapted instruments,respondents were scored on a 12-item instrument in knowledge where in each correct answercorrespond to one point, 27-item instrument on healthy lifestyle in terms of diet where in eachappropriate response correspond to one point, and 4-item instrument on healthy lifestyle interms of physical activities. In turn, the highest possible score of knowledge, diet, and physicalactivities are 12, 27, and 4, respectively. Descriptive results revealed that respondents havehigh knowledge on healthy lifestyle, have fair dietary practices and moderate practice ofphysical activities. Furthermore, knowledge on healthy lifestyle is not significantly correlatedto dietary practices physical activities. However, a significant relationship was found whenrespondents were grouped according to age; only those 24 years old and above were found tohave significant results. Hence, a recommendation to increase the accessibility andreinforcement values of exercise and physical activity that will have immediate and long termhealth benefits for college students
Software público, libre, abierto, gratuito, privativo y comercial para la innovación y mejora de la calidad en la docencia, investigación, gestión y asistencia
The public free software (now renamed as open software) is the basis of the open source software (OSS) project. This initiative promotes the use of open standards and platform-independent accessibility. Many OSS products are free or low cost, which allows their deployment even in the absence of large economic resources (developing countries, schools, etc.). Besides, their source code can be modified, adapted and optimized by anyone, since it is public. Nevertheless, the OSS may also have drawbacks. Thus, its development may not be as orderly and hierarchical as the privative software is, and may not have an appropriate funding. This may jeopardize the ease of use and coherence of the final product, increasing the transition, training and technical support costs. Besides, it must be taken into account that there is also commercial open software, as well as free privative software. In any case, the excellence of the software may be independent of such variables. Thus, the best strategy is the coexistence and free competition of all kinds of software. This will allow a quality improvement and an innovation enhancement, which will benefit the education, research, management and assistance at the university in particular and at the whole society in general.El software público libre es el fundamento del movimiento de software de fuente abierta (OSS). Éste puede facilitar el uso de estándares abiertos, con accesibilidad independiente de plataforma informática. El bajo coste o gratuidad de muchos productos OSS permite su implantación cuando los recursos económicos son escasos (países en desarrollo, escuelas, etc.). Además, su código se puede modificar, adaptar y mejorar por cualquiera, ya que es público. No obstante, el OSS también puede presentar inconvenientes. Así, su desarrollo puede no ser tan ordenado y jerárquico como el del software privativo y puede no tener una financiación apropiada. De este modo, puede verse comprometida la facilidad de uso y coherencia del producto final. Ello puede incrementar los costes de transición, entrenamiento y soporte técnico. Por otra parte, conviene recordar que existe software libre comercial y software privativo gratuito. En cualquier caso, la excelencia del software puede ser independiente de dichas variables. Por tanto, la mejor estrategia es la coexistencia y libre competencia de todo tipo de software. Así se puede conseguir una mejora de calidad y una potenciación de la innovación, que beneficie a la docencia, investigación, gestión y asistencia universitarias en particular, así como a la sociedad en general
Structural insight into the TRIAP1/PRELI-like domain family of mitochondrial phospholipid transfer complexes
The composition of the mitochondrial membrane is important for its architecture and proper function. Mitochondria depend on a tightly regulated supply of phospholipid via intra-mitochondrial synthesis and by direct import from the endoplasmic reticulum. The Ups1/PRELI-like family together with its mitochondrial chaperones (TRIAP1/Mdm35) represent a unique heterodimeric lipid transfer system that is evolutionary conserved from yeast to man. Work presented here provides new atomic resolution insight into the function of a human member of this system. Crystal structures of free TRIAP1 and the TRIAP1–SLMO1 complex reveal how the PRELI domain is chaperoned during import into the intermembrane mitochondrial space. The structural resemblance of PRELI-like domain of SLMO1 with that of mammalian phoshatidylinositol transfer proteins (PITPs) suggest that they share similar lipid transfer mechanisms, in which access to a buried phospholipid-binding cavity is regulated by conformationally adaptable loops
Extreme climatic events affect populations of Asian chestnut gall wasps, Dryocosmus kuriphilus, but do not stop the spread
[EN] Global climate change affects the frequency of extreme weather events that can influence plant–insect interactions. We evaluated how the late-spring frost and severe drought that occurred in Spain in 2017 affected interactions between the invasive gall insect, Dryocosmus kuriphilus, and the native tree, Castanea sativa. We assessed effects on insect survival, fertility, population growth, and effects through changes in tree palatability and in other pests and pathogens. Late-spring frost reduced D. kuriphilus to 25–40% of previous abundance. Wasp populations recovered rapidly (>7-fold in 3 years), consistent with density-dependence in population dynamics. Larvae affected by freeze or drought were smaller. Female fecundity was affected by the freeze 1 year later. Late-spring frosts and severe drought affected leaf size and physiology. Water content was higher within galls, but nitrogen was higher within galls in non-freeze plots after weather conditions improved. Freezing also influenced the secondary chemistry of leaves. Phenol concentrations were lower, and terpenes higher, in frozen plots, while condensed tannins remained the same. Condensed tannins were reduced to half in the drought year. Freezing had limited effects on damage from other pests and pathogens. Our work expands understanding of how climate and weather affects forest pestsSIThis work was supported by FEDER/Spanish Ministry of Economy and Competitiveness Research (Grant AGL2016-76262-R). Diana Blanco, Elva Rico, and Naidu Lombardero provided assistance in the field and in the lab. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this pape
Extreme climatic events affect populations of Asian chestnut gall wasps, Dryocosmus kuriphilus, but do not stop the spread
1 Global climate change affects the frequency of extreme weather events that can influence plant–insect interactions.
2 We evaluated how the late-spring frost and severe drought that occurred in Spain in 2017 affected interactions between the invasive gall insect, Dryocosmus kuriphilus, and the native tree, Castanea sativa. We assessed effects on insect survival, fertility, population growth, and effects through changes in tree palatability and in other pests and pathogens.
3 Late-spring frost reduced D. kuriphilus to 25–40% of previous abundance. Wasp populations recovered rapidly (>7-fold in 3 years), consistent with density-dependence in population dynamics.
4 Larvae affected by freeze or drought were smaller. Female fecundity was affected by the freeze 1 year later.
5 Late-spring frosts and severe drought affected leaf size and physiology.Water content was higher within galls, but nitrogen was higher within galls in non-freeze plots after weather conditions improved.
6 Freezing also influenced the secondary chemistry of leaves. Phenol concentrations were lower, and terpenes higher, in frozen plots, while condensed tannins remained the same. Condensed tannins were reduced to half in the drought year.
7 Freezing had limited effects on damage from other pests and pathogens.
8 Our work expands understanding of how climate and weather affects forest pestsThis work was supported by FEDER/Spanish Ministry of Economy and Competitiveness Research (Grant AGL2016-76262-R)S
Defensive patterns of chestnut genotypes (Castanea spp.) against the gall wasp, Dryocosmus kuriphilus
Plants draw from various genetically controlled defenses to protect against herbivores and pathogens. The efficacy of alternative defenses can vary with the biology and phylogeny of the enemy. Dryocosmus kuriphilus, an invasive gall maker native to China, has become one of the main pests of chestnut trees around the world. We studied genetic variation in resistance and susceptibility to D. kuriphilus within a replicated blocked planting of 12 chestnut genotypes established in Galicia, Spain in 2004. We found very high genetic variation in susceptibility to D. kuriphilus. We evaluated if the variation was due to host selection by the wasp, differential efficacy of inducible defenses in the trees, or variability in susceptibility of the plant to manipulation by the gallmaker. We assessed host selection by counting number of eggs laid by females in tree buds and comparing preferences with phytochemistry. We also measured inducible changes in phytochemistry within and around galls, gall physical characteristics, parasitism, and insect fitness. The effective defense mechanisms in resistant genotypes involved (1) hypersensitive reactions to eggs or neonates within buds and (2) early precise abscission of nascent galls from expanding leaves. Surprisingly, the genetic resistance to D. kuriphilus of the chestnut genotypes we tested was not related to phenols, terpenes, and primary nutritionSIThis work was supported by FEDER/Spanish Ministry of Economy and Competitiveness (Research Grant AGL2016-76262-R)
Phenological mismatches and the demography of solitary bees
Species respond idiosyncratically to environmental variation, which may generate phenological mismatches. We assess the consequences of such mismatches for solitary bees. During 9 years, we studied flowering phenology and nesting phenology and demography of five wood-nesting solitary bee species representing a broad gradient of specialization/generalization in the use of floral resources. We found that the reproductive performance and population growth rate of bees tended to be lower with increasing nesting-flowering mismatches, except for the most generalized bee species. Our findings help elucidate the role of phenological mismatches for the demography of wild pollinators, which perform key ecosystem functions and provide important services for humanity. Furthermore, if climate change increases phenological mismatches in this system, we expect negative consequences of climate change for specialist bees.Fil: Vazquez, Diego P.. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina. Albert Ludwigs University of Freiburg; AlemaniaFil: Vitale, Nydia Luciana. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; ArgentinaFil: Dorado, Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Amico, Georgina. Universidad Nacional de Cuyo; ArgentinaFil: Stevani, Erica Lujan. Universidad Nacional de Cuyo; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Provincia de Mendoza. Instituto Argentino de Investigaciones de las Zonas Áridas. Universidad Nacional de Cuyo. Instituto Argentino de Investigaciones de las Zonas Áridas; Argentin
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