Probabilistic Inference from Arbitrary Uncertainty using Mixtures of Factorized Generalized Gaussians

This paper presents a general and efficient framework for probabilistic inference and learning from arbitrary uncertain information. It exploits the calculation properties of finite mixture models, conjugate families and factorization. Both the joint probability density of the variables and the likelihood function of the (objective or subjective) observation are approximated by a special mixture model, in such a way that any desired conditional distribution can be directly obtained without numerical integration. We have developed an extended version of the expectation maximization (EM) algorithm to estimate the parameters of mixture models from uncertain training examples (indirect observations). As a consequence, any piece of exact or uncertain information about both input and output values is consistently handled in the inference and learning stages. This ability, extremely useful in certain situations, is not found in most alternative methods. The proposed framework is formally justified from standard probabilistic principles and illustrative examples are provided in the fields of nonparametric pattern classification, nonlinear regression and pattern completion. Finally, experiments on a real application and comparative results over standard databases provide empirical evidence of the utility of the method in a wide range of applications

Stand Density in South Florida Tropical Forests: Implications for the Function and Management of Everglades Tree Islands

Within the continental US, the broadleaved forests of south Florida are exceptional in the abundance and diversity of tree species of tropical origin. Dry tropical forests are regionally most extensive in the upper Florida Keys, but are also represented on the mainland as fragments on limestone rocklands, and as “tree islands” embedded in the Everglades marsh. The exposed Everglades tree islands have a history of human use reaching back thousands of years, and are subject to frequent disturbance from tropical storms and hurricanes. They are sensitive to the hydrology of the surrounding marsh, which can lead to gradual changes in species composition or stand structure, or to the sudden loss of the woody component entirely, especially when low water tables are precursors to damaging fires. Tree islands serve as local hotspots of biodiversity, and as concentrators of phosphorus in a landscape defined by P-limitation. The mechanisms by which P reaches the tree islands and is sequestered there are complex and not completely understood, but may depend in part on transpiration and resupply of water from the adjacent wetlands. Since transpiration is a direct function of the transpiring leaf surface, which itself is expected to vary with stocking, we examined the relationship between leaf area index and stand density in 16 Everglades tree islands. To determine maximum stocking levels for such forests, we also calculated stand density for tropical forests throughout south Florida, using a protocol modified slightly from Woodard et al. 2003. Our results suggest that (1) stand density in many Everglades tree islands is well below the expressed potential of similar tropical assemblages, (2) low site occupancy may prevent such under-stocked forests from performing several ecosystem functions, and (3) stand density can serve as an effective metric of forest condition for management or restoration purposes

An identification procedure for woolly soft-flesh peaches by instrumental assessment

Woolliness in peaches, a negative attribute of sensory texture characterized by the lack of crispness and juiciness, also known as mealiness in other fruits, has been identified fruit-by fruit by instrumental means. The use of a non-supervised clustering data analysis procedure, studying crispness and juiciness, enables four instrumental degrees of texture degradation to be defined, of which woolliness appears to be the last stage. This procedure also provides some information on several experimental factors (ripeness stages, storage time and storage temperature) with regard to the onset of woolliness. It is confirmed through this study that, in Maycrest peaches, woolliness starts to appear after 2 weeks of storage at 5°C. Fruits classified at harvest in 'first' and 'second' ripeness stages are more susceptible to woolliness than those in the third ripeness stage. This clustering procedure may also be effective for studying other species, varieties and quality attributes of fruit

Exact Cross Sections for the Neutralino WIMP Pair-Annihilation

We derive a full set of exact, analytic expressions for the annihilation of the lightest neutralino pairs into all two-body tree-level final states in the framework of minimal supersymmetry. We make no simplifying assumptions about the neutralino nor about sfermion masses and mixings other than the absence of explicit CP--violating terms. The expressions should be particularly useful in computing the neutralino WIMP relic abundance without the usual approximation of partial wave expansion.Comment: LaTeX, 46 pages, no figures. Several minor typographical errors correcte

Responses of a native and a recent invader snail to warming and dry conditions: the case of the lower Ebro River

Aquatic habitats have been highly modified by human actions that reduce their native diversity and create conditions suitable for tolerant alien species. Pomacea maculata was detected in 2009 in both the alluvial plain and the final stretch of the Ebro River. Since then, a permanent population has stabilized in the littoral area of the river where the water level fluctuates according to the river discharge. Melanopsis tricarinata is an endemic snail species highly affected by the reduction in its natural habitat. Currently, the two species do not share the same reaches in the river, but the possibility exists, as the distribution of the P. maculata is constantly increasing. This study aims to analyse the diets and to assess the responses of both snails to global change. The diet of both species was analysed in the field and their responses to water warming and dryness compared under laboratory conditions. This study includes the calculation of future river water temperatures based on air temperature projections. In addition, based on water discharge management scenarios, the study estimated the increase in dry river bed area. The diet of both snail species was similar and based on Cladophora. P. maculata better resisted high temperatures and dry conditions than M. tricarinata. The projections of water temperatures showed an increase in daily temperatures, especially in summer. The hydraulic model suggested that a relevant increase in dry river bed areas will occur. Overall, these results provide insight into the global change factors that could favour P. maculata spread in the river and the reduction in suitable habitat for M. tricarinata and will be useful for future decisions of water discharge management

Produzione, mercato e consumi della cerasicoltura spagnola

La crisi di sovrapproduzione di alcune specie tradizionali sta favorendo la crescita del ciliegio, che mostra un costante incremento delle superfici, favorito dal rinnovamento varietale, dall’aumento dei consumi, dal miglioramento delle tecnologie di produzione e dalla precocità di maturazione. Tutti fattori che garantiscono alla Spagna elevata competitività nelle esportazioni verso i Paesi dell’Ue.Colaboración en el blog: Rivista di frutticoltura e di ortofloricoltura. Disponible: http://www.rivistafrutticoltura.it

Bycatch of the European purse-seine tuna fishery in the Atlantic Ocean for the period 2010-2016

This paper presents an update for the period 2010-2016 of the bycatch estimations for the European tuna purse seine fishery operating in the Atlantic Ocean. Bycatch data were collected by observers onboard. Observer coverage increased progressively from 15 trips in 2010, to 114 and 107 trips in 2015 and 2016 respectively. Bycatch data, as collected by the observers, were stratified by quarter and fishing mode (free school and floating object sets). The ratio of total to observed catches of the target species (skipjack, bigeye and yellowfin tunas) in each stratum was then used as raising factor. The average of the annual total bycatch estimated for the studied period was 9,515 t. Tunas (neritic tunas and small size tunas) represent the major part of the bycatch, followed by fin fish, sharks, billfishes, rays and turtles.En prens

The Burst Cluster: Dark Matter in a Cluster Merger Associated with the Short Gamma Ray Burst, GRB 050509B

We have identified a merging galaxy cluster with evidence of two distinct sub-clusters. The X-ray and optical data suggest that the subclusters are moving away from each other after closest approach. This cluster merger was discovered from observations of the well localized short-duration gamma-ray burst (GRB), GRB 050509B. The Swift/Burst Alert Telescope (BAT) source position is coincident with a cluster of galaxies ZwCl 1234.0+02916. The subsequent Swift/X-Ray Telescope (XRT) localization of the X-ray afterglow found the GRB coincident with 2MASX J12361286+2858580, a giant red elliptical galaxy in the cluster. Deep multi-epoch optical images were obtained to constrain the evolution of the GRB afterglow, including a 27480s exposure in the F814W band with Hubble Space Telescope Advanced Camera for Surveys (ACS), among the deepest imaging ever obtained towards a known galaxy cluster in a single passband. We perform a weak gravitational lensing analysis, including mapping the total mass distribution of the merger system. Combined with Chandra X-ray Observatory and Swift/XRT observations, we investigate the dynamical state of the merger to probe the nature of the dark matter component. Our weak gravitational lensing measurements reveal a separation of the X-ray centroid of the western subcluster from the center of the mass and galaxy light distributions, similar to that of the famous "Bullet cluster". We conclude that the "Burst cluster" is another candidate merger system for determining the nature of dark matter and for studying the environment of short GRBs. We discuss connections between the cluster dynamical state and/or matter composition and compact object mergers, the leading model for the origin of short GRBs. Finally, we present results from a weak lensing survey based on archival Very Large Telescope (VLT) images in the areas of 5 other short GRBs.Comment: 17 pages, 7 figures, accepted by Ap

PHOTOMATCH: AN OPEN-SOURCE MULTI-VIEW and MULTI-MODAL FEATURE MATCHING TOOL for PHOTOGRAMMETRIC APPLICATIONS

Automatic feature matching is a crucial step in Structure-from-Motion (SfM) applications for 3D reconstruction purposes. From an historical perspective we can say now that SIFT was the enabling technology that made SfM a successful and fully automated pipeline. SIFT was the ancestor of a wealth of detector/descriptor methods that are now available. Various research activities have tried to benchmark detector/descriptors operators, but a clear outcome is difficult to be drawn. This paper presents an ISPRS Scientific Initiative aimed at providing the community with an educational open-source tool (called PhotoMatch) for tie point extractions and image matching. Several enhancement and decolorization methods can be initially applied to an image dataset in order to improve the successive feature extraction steps. Then different detector/descriptor combinations are possible, coupled with different matching strategies and quality control metrics. Examples and results show the implemented functionality of PhotoMatch which has also a tutorial for shortly explaining the implemented methods