Assessing the impact of seasonal-rainfall anomalies on catchment-scale water balance components

Abstract. Although water balance components at the catchment scale are strongly related to annual rainfall, the availability of water resources in Mediterranean catchments also depends on rainfall seasonality. Observed seasonal anomalies in historical records are fairly episodic, but an increase in their frequency might exacerbate water deficit or water excess if the rainy season shortens or extends its duration, e.g., due to climate change. This study evaluates the sensitivity of water yield, evapotranspiration, and groundwater recharge to changes in rainfall seasonality by using the Soil Water Assessment Tool (SWAT) model applied to the upper Alento River catchment (UARC) in southern Italy, where a long time series of daily rainfall is available from 1920 to 2018. We compare two distinct approaches: (i) a "static" approach, where three seasonal features (namely rainy, dry, and transition fixed-duration 4-month seasons) are identified through the standardized precipitation index (SPI) and (ii) a "dynamic" approach based on a stochastic framework, where the duration of two seasons (rainy and dry seasons) varies from year to year according to a probability distribution. Seasonal anomalies occur when the transition season is replaced by the rainy or dry season in the first approach and when season duration occurs in the tails of its normal distribution in the second approach. Results are presented within a probabilistic framework. We also show that the Budyko curve is sensitive to the rainfall seasonality regime in UARC by questioning the implicit assumption of a temporal steady state between annual average dryness and the evaporative index. Although the duration of the rainy season does not exert a major control on water balance, we were able to identify season-dependent regression equations linking water yield to the dryness index in the rainy season

Two years of monitoring Supergiant Fast X-ray Transients with Swift

We present two years of intense Swift monitoring of three SFXTs, IGR J16479-4514, XTE J1739-302, and IGR J17544-2619 (since October 2007). Out-of-outburst intensity-based X-ray (0.3-10keV) spectroscopy yields absorbed power laws with by hard photon indices (G~1-2). Their outburst broad-band (0.3-150 keV) spectra can be fit well with models typically used to describe the X-ray emission from accreting NSs in HMXBs. We assess how long each source spends in each state using a systematic monitoring with a sensitive instrument. These sources spend 3-5% of the total in bright outbursts. The most probable flux is 1-2E-11 erg cm^{-2} s^{-1} (2-10 keV, unabsorbed), corresponding to luminosities in the order of a few 10^{33} to 10^{34} erg s^{-1} (two orders of magnitude lower than the bright outbursts). The duty-cycle of inactivity is 19, 39, 55%, for IGR J16479-4514, XTE J1739-302, and IGR J17544-2619, respectively. We present a complete list of BAT on-board detections further confirming the continued activity of these sources. This demonstrates that true quiescence is a rare state, and that these transients accrete matter throughout their life at different rates. X-ray variability is observed at all timescales and intensities we can probe. Superimposed on the day-to-day variability is intra-day flaring which involves variations up to one order of magnitude that can occur down to timescales as short as ~1ks, and whichcan be explained by the accretion of single clumps composing the donor wind with masses M_cl~0.3-2x10^{19} g. (Abridged)Comment: Accepted for publication in MNRAS. 17 pages, 11 figures, 8 table

Patrones de actividad y abundancias estacionales del Flamenco Andino (Phoe-nicoparrus andinus) en dos humedales contrastantes en Argentina

El Flamenco Andino utilizade forma complementaria y alternativa humedales altoandinos de Argentina, Bolivia, Chile y Perú,además de humedales en las tierras bajas de Argentina. Estudios previos se enfocaron en su com-portamiento en sitios andinos, pero no existen al momento estudios de este tipo en sitios de tierrasbajas. Debido a esto, el objetivo del estudio fue analizar los patrones de actividad, de despliegues decortejo y abundancias de esta especie de flamenco en dos humedales contrastantes. Los sitios de es-tudio fueron: la Laguna de Vilama, en el noroeste de Argentina y a 4500 m s.n.m., la cual es utilizadaen el verano durante el período reproductivo; y la Laguna Melincué, en la planicie del centro-este deArgentina y a 84 m s.n.m., que es utilizada durante el período no reproductivo invernal. Entre sitios yentre años hubo marcadas diferencias en la abundancia y en los patrones de actividad. En la Lagunade Vilama, los flamencos se alimentaron durante la mayor parte del tiempo (95%), mientras que enla Laguna Melincué, los flamencos mostraron un rango más amplio de comportamientos, destinandosólo el 60% del tiempo a alimentarse. No registramos despliegues nupciales (marchas) en la Lagunade Vilama, mientras que en la Laguna Melincué sí registramos marchas, las cuales fueron másfrecuentes y de mayor duración en aquellos años con mayores abundancias de flamencos. Las dife-rencias en actividades entre los sitios estarían asociadas a la calidad y disponibilidad de recursos yal momento del ciclo reproductivo, donde los sitios de tierras bajas proveen hábitats críticos paralas actividades de cortejo que finalmente influyen el éxito reproductivo en los humedales de los AltosAndes.The Andean Flamingo (Phoenicoparrus andinus), one of three flamingo species in southernSouth America makes complementary and alternative use of high Andean wetlands in Argentina, Bolivia,Chile and Peru, and lowland wetlands in Argentina over its life cycle. Previous studies have focused onits behavior in Andean sites, but there are no such studies in lowland sites. Therefore, we analyzed theactivity patterns, courtship displays, and individual abundance of this flamingo species at two contrastingwetland sites, Laguna de Vilama, located at 4500 m a.s.l. in northwestern Argentina and used in summerduring the breeding season, and Laguna Melincué, a lowland wetland located at 84 m a.s.l. in the plainsof central east Argentina and used in winter during the non-breeding season. There were marked differ-ences in flamingo abundance and activity patterns between sites and years. In Laguna de Vilama, fla-mingos were feeding most of the time (95%), whereas at Laguna Melincué, flamingos showed a broaderrange of behaviors, with only a 60% of time spent feeding. We did not record marching displays atLaguna de Vilama, whereas at Laguna Melincué we recorded marching events in each of the three studyyears, being more frequent and lasting longer in the year with higher flamingo abundance. The differ-ences in behaviors at these sites are associated with resource quality and availability and with timing ofthe reproductive cycle, with lowland wetlands providing critical habitats for courtship displays that influ-ence reproductive success of this species breeding colonies in high Andean wetlands. Accepted 1 Octo-ber 2014Fil: Derlindati, Enrique Javier. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto Geonorte; Argentina. Grupo de Conservación Flamencos Altoandinos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Romano, Marcelo C. Grupo de Conservación Flamencos Altoandinos; Argentina. Centro de Investigaciones en Biodiversidad y Ambiente. Rosario; ArgentinaFil: Cruz, Nancy N.. Grupo de Conservación Flamencos Altoandinos; Argentina. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto Geonorte; ArgentinaFil: Barisón, Caterina. Grupo de Conservación Flamencos Altoandinos; Argentina. Universidad Nacional del Litoral. Facultad de Humanidades y Ciencias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Arengo, Felicity. Grupo de Conservación Flamencos Altoandinos; Argentina. American Museum Of Natural History; Estados UnidosFil: Barberis, Ignacio Martín. Grupo de Conservación Flamencos Altoandinos; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

An inter model distance for clustering utility function

Conjoint Analysis is one of the most widely used techniques in the assessment of the consumer’s behaviors. This method allows to estimate the partial utility coefficients according to a statistical model linking the overall note of preference with the attribute levels describing the stimuli. Conjoint analysis results are useful in new-product positioning and market segmentation. In this paper a cluster-based segmentation strategy based on a new metric has been proposed. The introduced distance is based on a convex linear combination of two Euclidean distances em bedding information both on the estimated parameters and on the model fitting. Market segments can be then defined according to the proximity of the part-worth coecients and to the explicative power of the estimated models

Corrections to the apparent value of the cosmological constant due to local inhomogeneities

Supernovae observations strongly support the presence of a cosmological constant, but its value, which we will call apparent, is normally determined assuming that the Universe can be accurately described by a homogeneous model. Even in the presence of a cosmological constant we cannot exclude nevertheless the presence of a small local inhomogeneity which could affect the apparent value of the cosmological constant. Neglecting the presence of the inhomogeneity can in fact introduce a systematic misinterpretation of cosmological data, leading to the distinction between an apparent and true value of the cosmological constant. We establish the theoretical framework to calculate the corrections to the apparent value of the cosmological constant by modeling the local inhomogeneity with a $\Lambda LTB$ solution. Our assumption to be at the center of a spherically symmetric inhomogeneous matter distribution correspond to effectively calculate the monopole contribution of the large scale inhomogeneities surrounding us, which we expect to be the dominant one, because of other observations supporting a high level of isotropy of the Universe around us. By performing a local Taylor expansion we analyze the number of independent degrees of freedom which determine the local shape of the inhomogeneity, and consider the issue of central smoothness, showing how the same correction can correspond to different inhomogeneity profiles. Contrary to previous attempts to fit data using large void models our approach is quite general. The correction to the apparent value of the cosmological constant is in fact present for local inhomogeneities of any size, and should always be taken appropriately into account both theoretically and observationally.Comment: 16 pages,new sections added analyzing central smoothness and accuracy of the Taylor expansion approach, Accepted for publication by JCAP. An essay based on this paper received honorable mention in the 2011 Essay Context of the Gravity Research Foundatio

Can the cosmological constant be mimicked by smooth large-scale inhomogeneities for more than one observable?

As an alternative to dark energy it has been suggested that we may be at the center of an inhomogeneous isotropic universe described by a Lemaitre-Tolman-Bondi (LTB) solution of Einstein's field equations. In order to test such an hypothesis we calculate the low redshift expansion of the luminosity distance $D_L(z)$ and the redshift spherical shell mass density $mn(z)$ for a central observer in a LTB space without cosmological constant and show how they cannot fit the observations implied by a $\Lambda CDM$ model if the conditions to avoid a weak central singularity are imposed, i.e. if the matter distribution is smooth everywhere. Our conclusions are valid for any value of the cosmological constant, not only for $\Omega_{\Lambda}>1/3$ as implied by previous proofs that $q^{app}_0$ has to be positive in a smooth LTB space, based on considering only the luminosity distance. The observational signatures of smooth LTB matter dominated models are fundamentally different from the ones of $\Lambda CDM$ models not only because it is not possible to reproduce a negative apparent central deceleration $q^{app}_0$, but because of deeper differences in their space-time geometry which make impossible the inversion problem when more than one observable is considered, and emerge at any redshift, not only for $z=0$.Comment: 18 pages, corrected a typo in the definition of the energy density which doesn't change the conclusion, references adde

Replicase mediated resistance against Potato Leafroll Virus in potato Desirée plants.

Potato leafroll virus (PLRV) is a major menace for the potato production all over the world. PLRV is transmitted by aphids, and until now, the only strategy available to control this pest has been to use large amounts of insecticides. Transgenic approaches involving the expression of viral replicases are being developed to provide protection for plants against viral diseases. The purpose of this study was to compare the protection afforded by the differential expression of PLRV replicase transgene in potato plants cv. Desirée. Plants were genetically modified to express the complete sense PLRV replicase gene. Two constructions were used, one containing the constitutive 35SCaMV promoter and the other the phloem-specific RolA promoter from Agrobacterium rhizogenes. Transgenic plants were infected with PLRV in vitro, using infested aphids. In plants in which 35SCaMV controlled the expression of the PLRV replicase gene, signs of infection were initially detected, although most plants later developed a recovery phenotype showing undetectable virus levels 40 days after infection. In turn, those plants with the RolA promoter displayed an initial resistance that was later overcome. Different molecular mechanisms are likely to participate in the response to PLRV infection of these two types of transgenic plants

8Li+alpha decay of 12B and its possible astrophysical implications

The 12B excitation energy spectrum has been obtained from coincidence measurements of the 9Be+7Li -> 2alpha+8Li reaction at E{0}=52 MeV. The decay of the states at excitations between 10 and 16 Mev into alpha$+8Li has been observed for the first time. Observed alpha-decay indicates possible cluster structure of the 12B excited states. The influence of these states on the cross section of the astrophysically important 8Li(alpha,n)11B and 9Be+t reactions is discussed and the results are compared with existing results.Comment: accepted for publication in Europhysics Letter