On the Role of Large-Scale Solar Photospheric Motions in the Cosmic-Ray 1.68-YR Intensity Variation

Analysis of cosmic-ray intensity time evolution has led to the identification of intensity variations with several periodicities, most of them correlated with one or another phenomenon of the Sun. Recently Valdés-Galicia, Pérez-Enriquez, and Otaola (1996) reported on a newly-found 1.68-yr variation, which seems to be correlated with periodicities in X-ray long-duration events and low-latitude coronal hole area variations. As those phenomena are related with magnetic flux emergence and transport, in this paper we investigate the possible relationship of the referred cosmic-ray variation with characteristic times of different tracers of meridional circulation. Our results indicate that several of the calculated times might be related to the 1.68-yr cosmic-ray variation. A physical mechanism through which this connection may operate is discussed.     

Sociological Profile of Astronomers in Spain

In this paper the main findings are presented of a recent study made by a team of sociologists from the University of Granada on the professional astronomers currently working in Spain. Despite the peculiarities of this group – its youth, twentyfold increase in size over the last 20 years, and extremely high rate of specialization abroad – in comparison with other Spanish professionals, this is the first time that the sociological characteristics of the group have been studied discretely. The most significant results of the study are presented in the following sections. Section 1 gives a brief historical background of the development of Astronomy in Spain. Section 2 analyzes the socio-demographic profile of Spanish Astronomy professionals (sex, age, marital status, etc.). Sections 3–5 are devoted to the college education and study programs followed by Spanish astronomers, focusing on the features and evaluations of the training received, and pre- and postdoctoral study trips made to research centers abroad. The results for the latter clearly show the importance that Spanish astronomers place on having experience abroad. Special attention is paid to scientific papers published as a result of joint research projects carried out with colleagues from centers abroad as a result of these study trips. Section 6 describes the situation of Astronomy professionals within the Spanish job market, the different positions available and the time taken to find a job after graduation. Section 7 examines Astronomy as a discipline in Spain, including the astronomers' own opinions of the social status of the discipline within Spanish society. Particular attention is paid to how Spanish astronomers view the status of Astronomy in Spain in comparison with that of other European countries. This revised version was published online in July 2006 with corrections to the Cover Date.     

Vertical deformation partitioning across a collapsing large and hot orogen

Featuring 3 000-km-long large and hot orogen, the Mantiqueira Province provides a rare opportunity to study the process of gravitational collapse at mid to deep crustal levels. Distinct but contemporary (~500 Ma) post-collisional intrusions show structures and anisotropy of magnetic susceptibility (AMS) fabrics related to their emplacements, recording different flow patterns. In southern deep-seated intrusions, ellipsoidal-shaped roots with gabbroic-to-hybrid cores surrounded by granitic rocks show concentric patterns of AMS fabrics that cut across the NE-trending regional foliation. In contrast, northern intrusions, exposed as the upper sections of batholith-size bodies of coarse-grained granite emplaced at the shallow to mid-crust, show general NS-trending magnetic fabrics roughly parallel to strike of the orogen and the regional foliation of host rocks. These contrasting magnetic patterns from shallow to deeper crust suggest vertical magma migration from the overthickened orogenic core to be emplaced across its thinner stretched flanks during the gravitational collapse of the orogenic edifice.     

The Berduc L6 chondrite fall: Meteorite characterization,trajectory, and orbital elements

Abstract– The fall of the Berduc meteorite took place on April 7, 2008, at 01 h 02 min 28 s ± 1 s UTC. A daylight fireball was witnessed by hundreds of people from Argentina and Uruguay, and also recorded by an infrasound array in Paraguay. From the available data, the fireball trajectory and radiant have been reconstructed with moderate accuracy. The modeled trajectory was tested to fit the infrasound and strewn field data. From the computed apparent radiant α = 87 ± 2° and δ = ?11 ± 2° and taking into account a range of plausible initial velocities, we obtained a range of orbital solutions. All of them suggest that the progenitor meteoroid originated from the main asteroid belt and followed an orbit of low inclination. Based on petrography, mineral chemistry, magnetic susceptibility, and bulk chemistry, the Berduc meteorite is classified as an L6 ordinary chondrite.     

Some statistical properties of Ellerman bombs

One hundred seventy-eight Ellerman bombs were identified and studied with on- and off-band H filtergrams of two active centers, one near disk center and the other near the east limb. The photographs, taken through a 1/4 Å bandpass filter, occasionally attained resolution as fine as 0.3. The mean duration of bombs at H-2 Å was about 13 min near disk center and 11 min near the limb; these times increase slightly when we observe closer to the core of H. Eighty-six percent of the bombs in the near-limb region and 56% in the disk-center region were seen to be accompanied by ejections of dark material; the ejections were 3–30 long. The ejection length appears to be proportional to the bomb size times the bomb lifetime.     

Understanding how environmental heterogeneity and elevation drives the distribution of woody communities across vegetation types within the campo rupestre in South America

The campo rupestre sensu lato is a vegetation type that occurs in South American mountains, supports a distinctive flora characterized by high rates of endemism, high herbaceous species richness and often-neglected but also species-rich of the arboreal stratum. We aimed to investigate how environmental factors and elevation are associated with the distribution and diversity of woody species in different rupestrian vegetation types across South America. Using a database of 2,049 woody species from 185 sites across four vegetation types within the campo rupestre, we assessed how the vegetation types were grouped according to their floristic composition and number of shared indicator species, as well as by using different beta diversity indices. The most important variables from a set of 27 variables(e.g. altitude, geo-edaphic and climatic) explaining species distribution were identified using redundancy analysis(RDA) and variation partitioning methods. The distribution of vegetation types was related to both environmental and spatial fractions, with a set of 17 variables retained(e.g. rockiness, grass cover and temperature seasonality as the most important variables). There was an association between the floristic composition of each vegetation type and the elevation range. Although the identified vegetation types are floristically related, they are distinguished by exclusive and habitat-specialist woody species. This uniqueness of vegetation types should be considered in terms of complementarity for the conservation of campos rupestres.