OH 1720 MHz Masers in Supernova Remnants --- C-Shock Indicators

Recent observations show that the OH 1720 MHz maser is a powerful probe of the shocked region where a supernova remnant strikes a molecular cloud. We perform a thorough study of the pumping of this maser and find tight constraints on the physical conditions needed for its production. The presence of the maser implies moderate temperatures (50 -- 125 K) and densities ($\sim 10^5 cm^{-3}$), and OH column densities of order $10^{16} cm^{-2}$. We show that these conditions can exist only if the shocks are of C-type. J-shocks fail by such a wide margin that the presence of this maser could become the most powerful indicator of C-shocks. These conditions also mean that the 1720 MHz maser will be inherently weak compared to the other ground state OH masers. All the model predictions are in good agreement with the observations.Comment: 16 pages, 5 Postscript figures (included), uses aaspp4.sty. To appear in the Astrophysical Journa

Selective Precipitation and Purification of Monovalent Proteins Using Oligovalent Ligands and Ammonium Sulfate

This paper describes a method for the selective precipitation and purification of a monovalent protein (carbonic anhydrase is used as a demonstration) from cellular lysate using ammonium sulfate and oligovalent ligands. The oligovalent ligands induce the formation of protein–ligand aggregates, and at an appropriate concentration of dissolved ammonium sulfate, these complexes precipitate. The purification involves three steps: (i) the removal of high-molecular-weight impurities through the addition of ammonium sulfate to the crude cell lysate; (ii) the introduction of an oligovalent ligand and the selective precipitation of the target protein–ligand aggregates from solution; and (iii) the removal of the oligovalent ligand from the precipitate by dialysis to release the target protein. The increase of mass and volume of the proteins upon aggregate formation reduces their solubility, and results in the selective precipitation of these aggregates. We recovered human carbonic anhydrase, from crude cellular lysate, in 82% yield and 95% purity with a trivalent benzene sulfonamide ligand. This method provides a chromatography-free strategy of purifying monovalent proteins—for which appropriate oligovalent ligands can be synthesized—and combines the selectivity of affinity-based purification with the convenience of salt-induced precipitation.Chemistry and Chemical Biolog

An evaluation of Bradfordizing effects

The purpose of this paper is to apply and evaluate the bibliometric method Bradfordizing for information retrieval (IR) experiments. Bradfordizing is used for generating core document sets for subject-specific questions and to reorder result sets from distributed searches. The method will be applied and tested in a controlled scenario of scientific literature databases from social and political sciences, economics, psychology and medical science (SOLIS, SoLit, USB Köln Opac, CSA Sociological Abstracts, World Affairs Online, Psyndex and Medline) and 164 standardized topics. An evaluation of the method and its effects is carried out in two laboratory-based information retrieval experiments (CLEF and KoMoHe) using a controlled document corpus and human relevance assessments. The results show that Bradfordizing is a very robust method for re-ranking the main document types (journal articles and monographs) in today’s digital libraries (DL). The IR tests show that relevance distributions after re-ranking improve at a significant level if articles in the core are compared with articles in the succeeding zones. The items in the core are significantly more often assessed as relevant, than items in zone 2 (z2) or zone 3 (z3). The improvements between the zones are statistically significant based on the Wilcoxon signed-rank test and the paired T-Test

Thermoelastic Damping in Micro- and Nano-Mechanical Systems

The importance of thermoelastic damping as a fundamental dissipation mechanism for small-scale mechanical resonators is evaluated in light of recent efforts to design high-Q micrometer- and nanometer-scale electro-mechanical systems (MEMS and NEMS). The equations of linear thermoelasticity are used to give a simple derivation for thermoelastic damping of small flexural vibrations in thin beams. It is shown that Zener's well-known approximation by a Lorentzian with a single thermal relaxation time slightly deviates from the exact expression.Comment: 10 pages. Submitted to Phys. Rev.

Poliartritis asociada a leishmaniasis en un canino del nordeste argentino

<p In one of the stages of leishmaniasis an immune-mediated reaction occurs, with formation of immune complexes that are deposited at the joint level, among other places. The objective of the present work was to report the radiological findings observed in a canine, female, mixed, with a positive diagnosis of leishmaniasis and signs of joint disease. Radiologically, erosive alterations were observed in the joints of both sides of the carpus and tarsus. The northeastern region of Argentina is considered as a moderate to intense transmission area of leishmaniasis, the infrequent presentation signs of osteoarticular disease must be taken into account. The importance of these radiological manifestations relies in the fact that they reflect the macroscopic pathological anatomy of the disease and allows to identify the stage in which the lesion is located at the articular level, making it possible to carry out a differential diagnosis with other arthropathies. p> En una de las etapas de la leishmaniasis se produce una reacción inmunomediada, con formación de complejos inmunes que se depositan -entre otros lugares- a nivel articular. El objetivo del presente trabajo fue reportar los hallazgos radiológicos observados en un canino hembra, mestizo, con diagnóstico positivo de leishmaniasis y signos de enfermedad articular, entre otros propios de la infección. Radiológicamente se observaron alteraciones erosivas en las articulaciones de ambos lados del carpo y del tarso. El nordeste argentino es considerado como un área de transmisión moderada a intensa de leishmaniasis, razón por la cual los infrecuentes signos de presentación de patologías osteoarticulares deben ser tenidos en cuenta en esta enfermedad. La importancia de las manifestaciones radiológicas reside en el hecho de que reflejan la anatomía patológica macroscópica de la enfermedad y permiten identificar la etapa en la que se encuentra la lesión a nivel articular, posibilitando la realización un diagnóstico diferencial con otras artropatías.

State-of-the-art in product service-systems

A Product Service-System (PSS) is an integrated combination of products and services. This western concept embraces a service-led competitive strategy, environmental sustainability, and the basis to differentiate from competitors who simply offer lower priced products. This paper aims to report the state-of-the-art of PSS research by presenting a clinical review of literature currently available on this topic. The literature is classified and the major outcomes of each study are addressed and analysed. On this basis, this paper defines the PSS concept, reports on its origin and features, gives examples of applications along with potential benefits and barriers to adoption, summarises available tools and methodologies, and identifies future research challenges

Comparación entre las técnicas de aproximación crushing y no–crushing para la sutura del intestino delgado del perro

Las ventajas y eventuales secuelas de las distintas técnicas de sutura intestinal aplicables al canino aún son controversiales. El objetivo de este trabajo fue determinar, dentro de las técnicas de aproximación (aposicionales), el patrón de sutura más adecuado para el intestino delgado de esta especie, teniendo en cuenta la eficiencia oclusiva anatómica (impermeabilidad) y la evolución del proceso cicatrizal desde el punto de vista histopatológico. Treinta perros fueron divididos en cinco grupos de igual número de ejemplares. A cada uno de ellos se les practicaron dos incisiones longitudinales de 2 cm de longitud (distanciadas 10 cm entre sí) en el segmento terminal del íleon. Una de las incisiones fue suturada por técnica crushing y la otra por no–crushing. Los caninos fueron sometidos a una segunda cirugía, realizada (según el grupo) a las 24, 48 y 96 h, así como a los 7 y 14 días, para efectuar una resección del segmento intestinal conteniendo ambas incisiones suturadas, a efectos de evaluar macro y microscópicamente los resultados de cada técnica. Las características macroscópicas fueron valoradas de visu. Las variables histopatológicas se categorizaron según los grados de hemorragia, edema, necrosis, inflamación, neovascularización y organización de tejido conectivo joven, analizándose mediante estadísticas no paramétricas (Kruskal–Wallis). Si bien no hubo diferencias finales significativas entre ambos tipos de sutura (p < 0,05), debe destacarse que a las 96 horas las lesiones con sutura no–crushing mostraban signos de inflamación exudativa, que no fueron observados en las incisiones suturadas por técnica crushing. Tal circunstancia, aunada al hecho que en las suturas no–crushing se hallaron cicatrices más exuberantes a nivel de la serosa, así como presencia de glándulas de la mucosa en la túnica muscular (indicando inadecuado afrontamiento aposicional), aconsejan la utilización de la técnica crushing para suturar el intestino delgado del perro

SRAO CO Observation of 11 Supernova Remnants in l = 70 to 190 deg

We present the results of 12CO J = 1-0 line observations of eleven Galactic supernova remnants (SNRs) obtained using the Seoul Radio Astronomy Observatory (SRAO) 6-m radio telescope. The observation was made as a part of the SRAO CO survey of SNRs between l = 70 and 190 deg, which is intended to identify SNRs interacting with molecular clouds. The mapping areas for the individual SNRs are determined to cover their full extent in the radio continuum. We used halfbeam grid spacing (60") for 9 SNRs and full-beam grid spacing (120") for the rest. We detected CO emission towards most of the remnants. In six SNRs, molecular clouds showed a good spatial relation with their radio morphology, although no direct evidence for the interaction was detected. Two SNRs are particularly interesting: G85.4+0.7, where there is a filamentary molecular cloud along the radio shell, and 3C434.1, where a large molecular cloud appears to block the western half of the remnant. We briefly summarize the results obtained for individual SNRs.Comment: Accepted for publication in Astrophysics & Space Science. 12 pages, 12 figures, and 3 table

Religion, Partisanship, and Attitudes Toward Science Policy

We examine issues involving science which have been contested in recent public debate. These “contested science” issues include human evolution, stem-cell research, and climate change. We find that few respondents evince consistently skeptical attitudes toward science issues, and that religious variables are generally strong predictors of attitudes toward individual issues. Furthermore, and contrary to analyses of elite discourse, partisan identification is not generally predictive of attitudes toward contested scientific issues