899 research outputs found
Modelling concurrent systems specified in a temporal concurrent constraint language -I
In this paper we present an approach to model concurrent systems specified in a temporal concurrent constraint language. Our goal is to construct a framework in which it is possible to apply the Model Checking technique to programs specified in such language. This work is the first step to the framework construction. We present a formalism to transform a specification into a tcc Structure. This structure is a graph representation of the program behavior. Our basic tool is the Timed Concurrent Constraint Programming (tcc) framework defined by Saraswat et al. to describe reactive systems. With this language we take advantage of both the natural properties of the declarative paradigm and of the fact that the notion of time is built into the semantics of the programming language. In fact, on this ground it becomes reasonable to introduce the idea of applying the technique of Model Checking to a finite time interval (introduced by the user). With this restriction we naturally force the space representing the behavior of the program to be finite and hence Model Checking algorithms to be applicable. The graph construction is a completely automatic process that takes as input the tcc specification
The new species Neoceroplatus betaryiensis nov. sp. (Diptera: Keroplatidae) from Neotropical Region
The species Neoceroplatus betaryiensis sp. nov. is presented here with the diagnosis of the species with indication of the ZooBank number, making this publication the valid description of the species
Influence of bulla volume on postbullectomy outcome
Objective: To quantify the contribution of the resected volume and the presence of associated, functionally significant emphysema to the postoperative improvement of pulmonary function after resection of giant lung bullae. Design: Patients undergoing elective surgery for giant bullae who had complete pulmonary function and radiographic studies performed were reviewed retrospectively. Setting: All 25 patients underwent surgery at the thoracic surgery unit of the University of Pisa, Pisa, Italy. Methods: Pulmonary function was assessed before and 12 months after surgery. On the chest radiograph, the location of bullae, and the signs of compression and emphysema were evaluated. The radiographic total lung capacity (TLCX-ray) and the volume of bullae were measured according to the ellipse method. Postoperatively, functional and radiographic changes were analyzed. The percentage change in forced expiratory volume in 1 s(ΔFEV1%) after surgery was the main outcome measure. The influence of factors related to emphysema and bulla volume on the functional improvement postbullectomy was assessed by stepwise multiple regression. Results: Before surgery, the TLCx-ray overestimated the TLC measured by nitrogen washout, with a mean difference between the two measurements of 1.095 L. A close relationship was found between the TLCx-ray and the plethysmographic TLC (n=6; r=0.95). After surgery, dyspnea lessened (P<0.05) and FEV1 increased (P<0.01). Statistically, the radiographic bulla volume was the single most important factor determining the ΔFEV1% (r=0.80, P<0.0001). Conclusions: These findings suggest that the preoperative size of bullae is the most important contributor to the improvement in ventilatory capacity after bullectomy, and that it is possible to predict the expected increase of postoperative FEV1 from preoperative bulla volume
Validation of digital elevation models in the Central Andes of Chile
Este estudio validĂł la precisiĂłn y exactitud vertical de siete modelos de elevaciĂłn digital DEM (SRTM X-SAR, SRTMv3 void filled 1 arcsec, SRTMv3 void filled 3 arcsec, SRTM GL1 Ellip, Aster GlobalDEM v3 2019/08. Alos World 3D 30m v21 2018/04, TamDEMx), a escalas regional y local en zonas de media y alta montaña de los Andes centrales de Chile. La precisiĂłn fue determinada utilizando pruebas estadĂsticas compiladas por el Instituto Nacional de NormalizaciĂłn (INN), las que consideraron datos de elevaciĂłn de 149 puntos de control terrestre con mediciones GNSS y 1825 PCT de la misiĂłn IceSat-2. A escala regional, los resultados del error entre el valor observado y el valor estimado, indican que el DEM SRTM X-SAR es el de mayor exactitud y precisiĂłn vertical (exactitud= 21,3 m equivalente al 85%; RMSEz=21,7 m equivalente al 86,8% de precisiĂłn). Sin embargo, su configuraciĂłn en bandas cruzadas no permite cálculos que aseguren la completitud de un área mayor a 2.500 km2 . Entonces, la siguiente opciĂłn es el DEM Alos World 3D 30m v21 2018/04 con exactitud de 22,5 m equivalente al 90%; RMSEz=23 m equivalente al 92%). A escala local y, considerando primero toda el área y todos los datos IceSat-2 y luego solo aquellas mediciones en zonas estables, el DEM Alos World 3d es el de mayor precisiĂłn y exactitud vertical, seguido del DEM AsterGDEMv3 19/08. En Ăşltimo lugar se ubica el DEM TamDEMx.This study validated the vertical exactitude and accuracy of seven digital elevation models DEM (SRTM X-SAR, SRTMv3 void voided 1 arcsec, SRTMv3 void filled 3 arcsec, SRTM GL1 Ellip, Aster GlobalDEM v3 2019/08. Alos World 3D 30m v21 2018/04, TamDEMx), considering both regional and local scale in middle/ higher mountain areas of the central Andes of Chile. Exactitude and Accuracy were determined using metrics and/or statistical tests reviewed by the National Institute of Standardization (INN), tests that considered the elevation data of 149 ground control acquired through several GNSS surveys, and 1825 gcp provided by IceSat-2 mission records. At the regional scale, the results of the error estimation between the observed and the predicted value indicate that the DEM SRTM X-SAR is the most precise and vertically accurate set (21,3 m of exactness equivalent to 85% of exactitude; RMSEz = 21,7 m of precision equivalent to 86.8% of accurate). However, the band layout does not allow calculations that ensure the completeness of an area greater than 2500 sqkm. Then, the next option is the DEM Alos World 3D 30m v21 2018/04 (22,5 m of exactness representing 90% of exactitude; RMSEz = 23 m equivalent to 92% of accurate). Locally, and first considering the entire area and all IceSat-2 data, and then only those measurements in stable zones, in both cases the Alos World 3d is the most exactly and vertically accurately DEM, followed by the DEM AsterGDEMv3 19/08. The poorest indicators belong to the DEM TamDEMx.Fil: Soza, Diego A.. No especifĂca;Fil: Falaschi, Daniel. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - Mendoza. Instituto Argentino de NivologĂa, GlaciologĂa y Ciencias Ambientales. Provincia de Mendoza. Instituto Argentino de NivologĂa, GlaciologĂa y Ciencias Ambientales. Universidad Nacional de Cuyo. Instituto Argentino de NivologĂa, GlaciologĂa y Ciencias Ambientales; Argentin
Do Salamanders Limit the Abundance of Groundwater Invertebrates in Subterranean Habitats?
Several species of surface salamanders exploit underground environments; in Europe, one of the most common is the fire salamander (Salamandra salamandra). In this study, we investigated if fire salamander larvae occurring in groundwater habitats can affect the abundance of some cave-adapted species. We analyzed the data of abundance of three target taxa (genera Niphargus (Amphipoda; Niphargidae), Monolistra (Isopoda; Sphaeromatidae) and Dendrocoelum (Tricladida; Dedrocoelidae)) collected in 386 surveys performed on 117 sites (pools and distinct subterranean stream sectors), within 17 natural and 24 artificial subterranean habitats, between 2012 and 2019. Generalized linear mixed models were used to assess the relationship between target taxa abundance, fire salamander larvae occurrence, and environmental features. The presence of salamander larvae negatively affected the abundance of all the target taxa. Monolistra abundance was positively related with the distance from the cave entrance of the sites and by their surface. Our study revealed that surface salamanders may have a negative effect on the abundance of cave-adapted animals, and highlited the importance of further investigations on the diet and on the top-down effects of salamanders on the subterranean communities
Mirrored images but not silicone models trigger aggressive responses in male common wall lizards
Disentangling the effects of single releasers in animal communication is a demanding task because a releaser often consists of a combination of different key stimuli. Territorial communication in reptiles usually depends on visual, chemical, and acoustic stimuli, but the role of each of them depends on phylogeny. Lacertids are modern lizards that rely mainly on chemical cues for their communication, but they also use aggressive displays based on visual recognition. We experimentally tested the visual stimuli that release an aggressive response in the males of a typical lacertid, the common wall lizard (Podarcis muralis), testing the effects of silicone models and mirrored images in captivity. The response to models and control (a blank sheet) was not significantly different and these stimuli did not release any aggressive behaviour. On the contrary, the reflected image in a mirror caused overt aggression (i.e., bites against it) in 63% of tested individuals. The results clearly demonstrate the role of visual stimuli in territorial communication, but only as a combined effect of shape and motion, differently from other lizard families for which shape is enough to stimulate aggre sive responses. Mirrors can be useful tools to investigate aggression related to physiological and morphological aspects in lacertid lizards
Annual to seasonal glacier mass balance in High Mountain Asia derived from Pl\ue9iades stereo images: examples from the Pamir and the Tibetan Plateau
\ua9 Copyright: Glaciers are crucial sources of freshwater in particular for the arid lowlands surrounding High Mountain Asia. To better constrain glacio-hydrological models, annual, or even better, seasonal information about glacier mass changes is highly beneficial. In this study, we evaluate the suitability of very-high-resolution Pl\ue9iades digital elevation models (DEMs) to measure glacier mass balance at annual and seasonal scales in two regions of High Mountain Asia (Muztagh Ata in Eastern Pamirs and parts of western Nyainq\ueantanglha, south-central Tibetan Plateau), where recent estimates have shown contrasting glacier behaviour. The average annual mass balance in Muztagh Ata between 2019 and 2022 was -0.07ĝ€\uaf\ub1ĝ€\uaf0.20ĝ€\uafmĝ€\uafw.e.ĝ€\uafa-1, suggesting the continuation of a recent phase of slight mass loss following a prolonged period of balanced mass budgets previously observed. The mean annual mass balance in western Nyainq\ueantanglha was highly negative for the same period (-0.60ĝ€\uaf\ub1ĝ€\uaf0.15ĝ€\uafmĝ€\uafw.e.ĝ€\uafa-1), suggesting increased mass loss rates compared to the approximately previous 5 decades. The 2022 winter (+0.13ĝ€\uaf\ub1ĝ€\uaf0.24ĝ€\uafmĝ€\uafw.e.) and summer (-0.35ĝ€\uaf\ub1ĝ€\uaf0.15ĝ€\uafmĝ€\uafw.e.) mass budgets in Muztagh Ata and western Nyainq\ueantanglha (-0.03ĝ€\uaf\ub1ĝ€\uaf0.27ĝ€\uafmĝ€\uafw.e. in winter; -0.63ĝ€\uaf\ub1ĝ€\uaf0.07ĝ€\uafmĝ€\uafw.e. in summer) suggest winter- and summer-accumulation-type regimes, respectively. We support our findings by implementing the Sentinel-1-based Glacier Index to identify the firn and wet-snow areas on glaciers and characterize the accumulation type. The good match between the geodetic and Glacier Index results supports the potential of very-high-resolution Pl\ue9iades data to monitor mass balance at short timescales and improves our understanding of glacier accumulation regimes across High Mountain Asia
- …