Mathematical Genesis of the Spatio-Temporal Covariance Functions

Obtaining new and flexible classes of nonseparable spatio-temporal covariances have resulted in a key point of research in the last years within the context of spatiotemporal Geostatistics. Approach: In general, the literature has focused on the problem of full symmetry and the problem of anisotropy has been overcome. Results: By exploring mathematical properties of positive definite functions and their close connection to covariance functions we are able to develop new spatio-temporal covariance models taking into account the problem of spatial anisotropy. Conclusion/Recommendations: The resulting structures are proved to have certain interesting mathematical properties, together with a considerable applicability.Spatial anisotropy, bernstein and complete monotone functions, spatio-temporal geostatistics, positive definite functions, space-time modeling, spatio-temporal data

The nucleon spin and momentum decomposition using lattice QCD simulations

We determine within lattice QCD, the nucleon spin carried by valence and sea quarks, and gluons. The calculation is performed using an ensemble of gauge configurations with two degenerate light quarks with mass fixed to approximately reproduce the physical pion mass. We find that the total angular momentum carried by the quarks in the nucleon is $J_{u+d+s}{=}0.408(61)_{\rm stat.}(48)_{\rm syst.}$ and the gluon contribution is $J_g {=}0.133(11)_{\rm stat.}(14)_{\rm syst.}$ giving a total of $J_N{=}0.54(6)_{\rm stat.}(5)_{\rm syst.}$ consistent with the spin sum. For the quark intrinsic spin contribution we obtain $\frac{1}{2}\Delta \Sigma_{u+d+s}{=}0.201(17)_{\rm stat.}(5)_{\rm syst.}$. All quantities are given in the $\overline{\textrm{MS}}$ scheme at 2~GeV. The quark and gluon momentum fractions are also computed and add up to $\langle x\rangle_{u+d+s}+\langle x\rangle_g{=}0.804(121)_{\rm stat.}(95)_{\rm syst.}+0.267(12)_{\rm stat.}(10)_{\rm syst.}{=}1.07(12)_{\rm stat.}(10)_{\rm syst.}$ satisfying the momentum sum.Comment: Version published in PR

Museum libraries in Spain: A case study at state level

Special libraries are essential information and documentation centres for university teachers and researchers due to the quality and richness of their collections. In Spain, it is estimated that there are 2456 special libraries, although many are unknown either generally or among information professionals. These include museum libraries, which are important centres with valuable collections of bibliographic heritage for the area of Humanities and Social Sciences. The aim of this research is to gain an understanding of the real state of these information units and promote the social value of museum libraries in Spain. To do this, a survey was sent to the libraries of state-owned and -managed museums under the General Directorate of Fine Arts and Cultural Property (Ministry of Culture and Sports) of the Government of Spain. This general objective will be accompanied by a review of the scientific literature on various aspects of museum libraries at national and international level. After addressing the research methodology, the results obtained will be discussed and will include the following topics: collection management, library services and staff, economic and technological resources and finally, library management. Conclusions include recommendations for museum librarians and reveal that institutional cooperation is a strategic issue to improve both museum libraries visibility and their social recognition as cultural and research centre

Spicule jets in the solar atmosphere modeled with resistive MHD and thermal conduction

Using numerical simulations, we study the effects of magnetic resistivity and thermal conductivity in the dynamics and properties of solar jets with characteristics of Type II spicules and cool coronal jets. The dynamic evolution of the jets is governed by the resistive MHD equations with thermal conduction along the magnetic field lines on a 2.5D slice. The magnetic field configuration consists of two symmetric neighboring loops with opposite polarity, used to support reconnection and followed by the plasma jet formation. In total, 10 simulations were carried out with different values of resistivity and thermal conductivity that produce jets with different morphological and thermal properties we quantify. We find that an increase in magnetic resistivity does not produce significant effects on the morphology, velocity, and temperature of the jets. However, thermal conductivity affects both temperature and morphology of the jets. In particular, thermal conductivity causes jets to reach greater heights and increases the temperature of the jet-apex. Also, heat flux maps indicate the jet-apex and corona interchange energy more efficiently than the body of the jet. These results could potentially open a new avenue for plasma diagnostics in the Sun's atmosphere

The Role of Intra-Clutch Variation of Magpie Clutches in Foreign Egg Rejection Depends on the Egg Trait Considered.

MM-M and JA conceived the idea and analyzed the data. MM-M led the writing of the manuscript. MP and JGM performed the experiment in the field work. JG and GL-C carried out the images processing and performed the analyzes related to fractal dimension. All authors contributed critically to the drafts and gave final approval for publication.We thank Brian Peer for inviting us to contribute to this special issue. We are also indebted to Daniel Hanley and Vanina Dafne Fiorini for comments that greatly improved the manuscript.The existence of a coevolutionary process between avian brood parasites and their hosts predicts a lower intra-clutch variation in egg appearance of host eggs among rejecters as this would favor egg discrimination of parasite eggs by hosts once parasitic egg mimicry had evolved. So far empirical tests of this prediction have ignored the fact that different aspects of host egg phenotypes may differ in the relative role of environmental vs. genetic determination, and hence that the role of intra-clutch variation in egg rejection within a population cannot be invariant. Here, we estimated whether the intra-clutch variation in several aspects of host eggshell features is consistently associated to rejection of parasitic foreign eggs across years in a magpie host population parasitized by great spotted cuckoos. We innovatively estimated spottiness by means of the fractal dimension of eggs, which considers the homogeneity of spot pattern complexity in eggshells. Our results show that low intra-clutch variation in the blue-green coloration at the middle area of the eggs associated with a high chance of rejection, but only in one of the 3 years we conducted the study. In addition, females that rejected foreign eggs presented more homogenous spot patterns in their clutches as estimated by their fractal dimension than females that accepted experimental eggs, independently of the year of study. Finally, intra-clutch variation in egg volume of host eggs was not associated to rejection. Analyses at the individual level revealed that the relative role of genetic vs. environmental factors that determine egg phenotype would be feature-specific in magpies, females having a characteristic spottiness, but not color or volume, pattern. Our work stresses the importance of considering a holistic approach including several aspects of variation in host egg phenotype (size, color, and homogeneity of spot pattern), as some aspects might be more susceptible to selection through egg rejection than others, presumably because they are less influenced by variation in the environmental conditions. Moreover, our study highlights the importance of replication in studies on the adaptive value of host traits in egg rejection.This study was made possible through funding by the Spanish Ministry of Science through different projects (CGL2011-27561 and CGL2014-55362-P), a grant (BES-2015-075675), the Juan de la Cierva–Incorporación Fellowship (IJC2018-036411-I), and the Junta de Andalucía through a project (P06-RNM-01862)

Dengue reemergence in Argentina.

Aedes aegypti, eradicated from Argentina in 1963, has now reinfested the country as far south as Buenos Aires. In 1997, four persons with travel histories to Brazil, Ecuador, or Venezuela had confirmed dengue, and surveillance for indigenous transmission allowed the detection of 19 dengue cases in Salta Province. These cases of dengue are the first in Argentina since 1916 and represent a new southern extension of dengue virus

Intake and Yield of \u3ci\u3eCynodon nlemfuensis\u3c/i\u3e Alone and Associated with \u3ci\u3eLeucaena leucocephala\u3c/i\u3e Grazed by Sheep

The objective of the present study was to determine dry matter intake (DMI) and the forage yield of green dry matter (GDM) of star grass (Cynodon nlemfuensis) alone and associated with Leucaena leucocephala cv. Perú grazed by sheep. The experimental treatments were: Systems T1) Star grass alone, and T2) Star grass + L. leucocephala. These treatments were evaluated during three seasons (i.e. Late-rainy, Dry and Rainy seasons). The availability of forage was lower (P \u3c 0.0001) in T1, 2543 kg GDM/ha, than with T2, 3092 kg GDM/ha. Green dry matter in the rainy season was greater (P \u3c 0.0001), with 3910 kg GDM/ha, than in the late-rainy and dry seasons, 2492 and 2052 kg GDM/ha, respectively. DMI was 5.9 and 7.6 g DM/kg of LW 0.75/hour for the T1 and T2, respectively (P \u3c 0.0001). DMI during the rainy season was lower (P \u3c 0.01) than that of the dry and late-rainy seasons, 6.2, 6.4 and 7.5 g DM/kg LW0.75/hour, respectively. The association C. nlemfuensis-L. leucocephala increased the availability of forage and the voluntary intake

ALTERED MARKERS OF TONIC INHIBITION IN THE DORSOLATERAL PREFRONTAL CORTEX OF SUBJECTS WITH SCHIZOPHRENIA

Alterations in the inhibitory circuitry of the dorsolateral prefrontal cortex (DLPFC) appear to contribute to the impairments in working memory observed in individuals with schizophrenia. Consistent with this idea, a microarray study indicated that the mRNA levels of GABAA receptor α4 and δ subunits were lower in the DLPFC of subjects with schizophrenia. However, although α4 and δ subunits co-assemble to form functional receptors, the differences in α4 and δ mRNA expression in schizophrenia were not correlated. We assessed the mRNA levels of α4 and δ in the DLPFC of 23 subjects with schizophrenia matched to control subjects by in situ hybridization. The level of α4 mRNA was lower only in subjects with schizophrenia receiving medications at the time of death, whereas the level of δ mRNA was significantly lower in schizophrenia, regardless of the medications used at the time of death. We also found that across postnatal development of monkey DLPFC the level of α4 mRNA decreased with age, whereas that of δ mRNA increased in a manner similar to that previously observed for the α1 subunit. Given that α1 mRNA levels are lower in schizophrenia and α1 subunits can co-assemble with δ subunits, lower δ mRNA in schizophrenia could represent lower GABAA α1βxδ rather than α4βxδ receptors. Studies suggest that reduced signaling through excitatory synapses, as hypothesized to be present in schizophrenia, give rise to decreased expression of δ subunit mRNA. To test this hypothesis, we measured the levels of δ subunit mRNA in the prefrontal cortex of four rodentmodels of reduced cortical excitatory drive: 1) NMDAR NR1 hypomorphic mice, 2) rats with adult mediodorsal thalamic nuclei lesions, 3) rats with neonatal ventral hippocampal lesions and 4) TrkB hypomorphic mice reported to have decreased dendritic arborization. However, the mRNA levels of δ subunit were unchanged in the PFC of any of the animal models analyzed. Thus, although reduced signaling through excitatory synapses might be a pathogenetic mechanism for other abnormalities in schizophrenia, the convergence of the findings from this study do not support the hypothesis that it accounts for the lower expression of GABAA receptor δ subunit mRNA

USO DEL GOOGLE EARTH™ PARA EVALUAR LA PÉRDIDA DE CUBIERTA VEGETAL EN CHINÁ, CAMPECHE, MÉXICO

Through the use of the geographic information system, Google Earth™, the loss of plant cover in the ejido of Chiná, Campeche, was measured for the period of 2003-2015, showing their trends, at the same time that the pertinence of the use of this tool by scholars and authorities to save in expenses was analyzed. The results show that deforestation has increased in the last 12 years with average losses of almost one hectare per year; 21 polygons of different sizes were identified between the years 2003, 2006, 2010, 2012, 2014 and 2015; of these, seven were present every year, the remaining 14 were intermittent, but with higher presence in 2012 to 2015. In average an increase was observed in the accumulated loss of cover of 235.36% between 2003 and 2015. The variance analysis (95 %) did not show significant differences between the years studied for the loss of plant cover.Mediante el uso del sistema de información geográfica Google Earth™, se midió la pérdida de cubierta vegetal en el ejido de Chiná, Campeche para el período de 2003-2015, mostrando sus tendencias, al mismo tiempo que se analizó la pertinencia del uso de esta herramienta para el ahorro de gastos por parte de los académicos y autoridades. Los resultados muestran que la deforestación ha incrementado en los últimos 12 años con pérdidas promedio de casi una hectárea por año; se identificaron 21 polígonos de tamaños diversos entre los años 2003, 2006, 2010, 2012, 2014 y 2015; de los cuales siete estuvieron presentes todos los años, los restantes 14 fueron intermitentes, pero con mayor presencia en 2012 al 2015. En promedio se observó aumento de la pérdida acumulada de cubierta del 235.36% entre2003 y 2015. El análisis de varianza (95%) no mostró diferencias significativas entre los años estudiados para la pérdida de cubierta vegeta

I. Jet Formation and Evolution due to 3D Magnetic Reconnection

Using simulated data-driven three-dimensional resistive MHD simulations of the solar atmosphere, we show that magnetic reconnection can be responsible of the formation of jets with characteristic of Type II spicules. For this, we numerically model the photosphere-corona region using the C7 equilibrium atmosphere model. The initial magnetic configuration is a 3D potential magnetic field, extrapolated up to the solar corona region from a dynamic realistic simulation of solar photospheric magnetoconvection model which is mimicking quiet-Sun. In this case we consider a uniform and constant value of the magnetic resistivity of 12.56 Ω m. We have found that formation of the jets depends on the Lorentz force, which helps to accelerate the plasma upwards. Analyzing various properties of the jet dynamics, we found that the jet structure shows Doppler shift near to regions with high vorticity. The morphology, upward velocity, covering a range up to 100 km s−1, and life-time of the estructure, bigger than 100 s, are similar to those expected for Type II spicules