Supernova--remnant origin of cosmic rays?

It is thought that Galactic cosmic-ray nuclei are gradually accelerated to high energies (up to about 300 TeV per nucleon, where 1 TeV is 10(12) eV) in the expanding shock waves connected with the remnants of powerful supernova explosions. However, this conjecture has eluded direct observational confirmation since it was first proposed in 1953 (ref. 3). Enomoto et al. claim to have finally found definitive evidence that corroborates this model, proposing that very-high-energy, TeV-range, gamma-rays from the supernova remnant (SNR) RX J1713.7-3946 are due to the interactions of energetic nuclei in this region. Here we argue that their claim is not supported by the existing multiwavelength spectrum of this source. The search for the origin(s) of Galactic cosmic-ray nuclei may be closing in on the long-suspected supernova-remnant sources, but it is not yet over.     

The male of Culicoides reevesi Wirth, with a redescription of the female and new seasonal activity, distribution, and biting records (Diptera: Ceratopogonidae)

The previously unknown male of the biting midge, Culicoides reevesi Wirth, is described and illustrated; the female is also redescribed and this species is reassigned to the leoni group. Previously known from California, Arizona, and New Mexico, C. reevesi is recorded for the 1st time from Utah ( new record ). Females of this aggressive, hematophagous species were collected while biting humans during evening crepuscular periods in California. Females exhibited a strong attraction to CO 2 traps, and seasonal surveillance demonstrated that host-seeking occurred from late May until mid-October in both California and Utah. Small numbers of males were also collected in CO 2 traps; however, both sexes showed little attraction to ultraviolet and incandescent light traps.     

Multiple discoveries,inevitability, and scientific realism

When two or more (groups of) researchers independently investigating the same domain arrive at the same result, a multiple discovery occurs. The pervasiveness of multiple discoveries in science suggests the intuition that they are in some sense inevitable—that one should view them as results that force themselves upon us, so to speak. We argue that, despite the intuitive force of such an “inevitabilist insight,” one should reject it. More specifically, we distinguish two facets of the insight and argue that: (a) the profusion of multiple discoveries in scientific practice does not support the inevitabilist side of the inevitability/contingency of science controversy; and (b) the crucial role of background knowledge in scientific inquiry complicates the attempt to interpret the pervasiveness of multiple discoveries in realist terms.     

Outline of a Theory of Scientific Aesthetics

I offer a theory of art that is based on science. I maintain that, as any other human activity, art can be studied with the tools of science. This does not mean that art is scientific, but aesthetics, the theory of art, can be formulated in accord with our scientific knowledge. I present elucidations of the concepts of aesthetic experience, art, work of art, artistic movement, and I discuss the ontological status of artworks from the point of view of scientific philosophy.     

Adversus Singularitates: The Ontology of Space–Time Singularities

I argue that there are no physical singularities in space–time. Singular space–time models do not belong to the ontology of the world, because of a simple reason: they are concepts, defective solutions of Einstein’s field equations. I discuss the actual implication of the so-called singularity theorems. In remarking the confusion and fog that emerge from the reification of singularities I hope to contribute to a better understanding of the possibilities and limits of the theory of general relativity.     

Traditional versus unobserved components methods to forecast quarterly national account aggregates

We aim to assess the ability of two alternative forecasting procedures to predict quarterly national account (QNA) aggregates. The application of Box–Jenkins techniques to observed data constitutes the basis of traditional ARIMA and transfer function methods (BJ methods). The alternative procedure exploits the information of unobserved high‐ and low‐frequency components of time series (UC methods). An informal examination of empirical evidence suggests that the relationships between QNA aggregates and coincident indicators are often clearly different for diverse frequencies. Under these circumstances, a Monte Carlo experiment shows that UC methods significantly improve the forecasting accuracy of BJ procedures if coincident indicators play an important role in such predictions. Otherwise (i.e., under univariate procedures), BJ methods tend to be more accurate than the UC alternative, although the differences are small. We illustrate these findings with several applications from the Spanish economy with regard to industrial production, private consumption, business investment and exports. Copyright © 2007 John Wiley & Sons, Ltd.     

A revision of the Patagonian predaceous midges of the subgenus Acanthohelea of Stilobezzia excluding the S. (A.) edwardsi group (Diptera: Ceratopogonidae)

In this revision of the Patagonian predaceous midges of Stilobezzia (Acanthohelea) (Diptera: Ceratopogonidae), the seven previously known species, Stilobezzia bicinctipes Ingram and Macfie, S. hirsuta I. and M, S. ornaticrus I. and M, S. patagonica I. and M, S. rava I. and M, S. succinea I. and M. and S. varia I. and M. are redescribed, illustrated and their distributions are expanded. Diagnoses are provided for Stilobezzia curvistyla Cazorla and Spinelli, S. longisternalis Cazorla and Spinelli and S. nigerrima I. and M, and the male of S. bicinctipes and the female of S. ornaticrus are described for the first time. Seven new species are described with photographs: S. estepae, S. mapuche, S. megatheca, S. monomorphica, S. pabloi, S. spinosa and S. tridentis. The species are illustrated by photographs, and a key to males and females is provided as well as distributional maps for all species.

http://zoobank.org/urn:lsid:zoobank.org:pub:CCEB2CB7-2FB3-4ABF-BCD4-75021AD6C338     

Composition and distribution patterns of chewing lice of two neotropical species of Turdus

We analyzed the prevalence and intensity of chewing lice on two neotropical species of Turdus and identified morphological parameters of birds influencing louse population dynamics. The study was conducted in southernmost Rio Grande do Sul state (RS), Brazil, between July 2009 and June 2010. Chewing lice were collected by dust-ruffling. The prevalence of chewing lice on both species of Turdus was high. Chewing lice from both species of Turdus exhibit similar composition and distribution patterns. However, chewing lice were more abundant on Turdus rufiventris, whereas species richness was higher on Turdus amaurochalinus. Myrsidea and Brueelia were the most prevalent and abundant genera on both host species in all seasons of the year. A predominance of chewing louse females and adults was observed. Aggregated distributions were observed. Body length was the only morphological parameter correlated with louse abundance, suggesting that specimens with a larger body have a higher abundance of lice.