Phonon-assisted optical absorption in silicon from first principles

The phonon-assisted interband optical absorption spectrum of silicon is calculated at the quasiparticle level entirely from first principles. We make use of the Wannier interpolation formalism to determine the quasiparticle energies, as well as the optical transition and electron-phonon coupling matrix elements, on fine grids in the Brillouin zone. The calculated spectrum near the onset of indirect absorption is in very good agreement with experimental measurements for a range of temperatures. Moreover, our method can accurately determine the optical absorption spectrum of silicon in the visible range, an important process for optoelectronic and photovoltaic applications that cannot be addressed with simple models. The computational formalism is quite general and can be used to understand the phonon-assisted absorption processes in general

Isolated diaphragm weakness and the diagnostic value of phrenic nerve stimulation

Acute onset, atraumatic, bilateral diaphragm paralysis due to isolated bilateral phrenic neuropathy is uncommon. Respiratory physicians should be alert to this disorder because it is associated with considerable morbidity and diagnosis is often delayed. These case reports highlight important aspects of the presentation, investigations and management of this disorder

Effect of K Doping on Phonons in Ba1-xKxFe2As2

The lattice dynamics of Ba1-xKxFe2As2 (x = 0.00, 0.27) have been studied by inelastic X-ray scattering measurement at room temperature. K doping induces the softening and broadening of phonon modes in the energy range E = 10-15 meV. Analysis with a Born-von Karman force-constant model indicates that the softening results from reduced interatomic force constants around (Ba,K) sites following the displacement of divalent Ba by monovalent K. The phonon broadening may be explained by the local distortions induced by the K substitution. Extra phonon modes are observed around the wave vector q = (0.5,0,0) at E = 16.5 meV for the x = 0.27 sample. These modes may arise either from the local disorder induced by K doping or from electron-phonon coupling.Comment: J. Phys. Soc. Jpn. (in press

Mapping Fusarium solani and Aphanomyces euteiches Root Rot Resistance and Root Architecture Quantitative Trait Loci in Common Bean

Root rot diseases of bean (Phaseolus vulgaris L.) are a constraint to dry and snap bean production. We developed the RR138 RI mapping population from the cross of OSU5446, a susceptible line that meets current snap bean processing industry standards, and RR6950, a root rot resistant dry bean with small brown seeds. We evaluated the RR138 RI population beginning in the F₆ generation for resistance to Fusarium solani f. sp. phaseoli (Burk.) root rot in Oregon and Aphanomyces euteiches (Drechsler) root rot in Wisconsin. The population was evaluated for a set of root architecture traits at the Oregon location. Fusarium solani root rot resistance was evaluated in three seasons, whereas A. euteiches resistance was evaluated in two seasons. For each disease, RR6950 was resistant and OSU 5446 was susceptible. The recombinant inbred (RI) population was normally distributed for reaction to both diseases. We assembled a high-density linkage map using 1689 single-nucleotide polymorphisms (SNPs) from an Illumina 6000-SNP BARCbean6K_3 Beadchip. The map spanned 1196 cM over 11 linkage groups at a density of one SNP per 1.4 cM. Three quantitative trait loci (QTL) associated with A. euteiches were identified, each accounting for 5 to 15% of the total genetic variation, and two QTL associated with F. solani resistance accounted for 9 and 22% of the total genetic variation. A QTL for taproot diameter (TD) and one QTL for basal root angle were identified. The QTL for resistance to the two diseases mapped to different genome locations indicating a different genetic control

The growth pattern of transplanted normal and nodular hepatocytes

Overt neoplasia is often the end result of a long biological process beginning with the appearance of focal lesions of altered tissue morphology. While the putative clonal nature of focal lesions has often been emphasized, increasing attention is being devoted to the possible role of an altered growth pattern in the evolution of carcinogenesis. Here we compare the growth patterns of normal and nodular hepatocytes in a transplantation system that allows their selective clonal proliferation in vivo. Rats were pre-treated with retrorsine, which blocks the growth of resident hepatocytes, and were then transplanted with hepatocytes isolated from either normal liver or hepatocyte nodules. Both cell types were able to proliferate extensively in the recipient liver, as expected. However, their growth pattern was remarkably different. Clusters of normal hepatocytes integrated in the host liver, displaying a normal histology; however, transplanted nodular hepatocytes formed new hepatocyte nodules, with altered morphology and sharp demarcation from surrounding host liver. Both the expression and distribution of proteins involved in cell polarity, cell communication, and cell adhesion, including connexin 32, E-cadherin, and matrix metalloproteinase-2, were altered in clusters of nodular hepatocytes. Furthermore, we were able to show that down-regulation of connexin 32 and E-cadherin in nodular hepatocyte clusters was independent of growth rate. These results support the concept that a dominant pathway towards neoplastic disease in several organs involves defect(s) in tissue pattern formation

The influence of contextual information regarding the breakdown of relationships and perpetrator-target sex composition on perceptions of relational stalking

The present study examines the influence of prior relationship (with contextual information regarding the breakdown of the relationship) and perpetrator-target sex composition on perceptions of relational stalking. The study employed an experimental 7 × 2 independent measures design, and the sample comprised 1,260 members of the community residing in Australia, the United Kingdom and the United States. Participants received one of 14 versions of a hypothetical scenario and responded to scale items concerning the situation described. The situation was perceived to be most serious when the perpetrator was a stranger or a physically violent ex-partner and least serious when the perpetrator was an ex-partner of an unfaithful target. Scenarios involving a male perpetrator and a female victim were also perceived to be more serious than scenarios involving a female perpetrator and a male target. It is apparent therefore that the context of the relationship breakdown and the sex of the perpetrator and target significantly influence perceptions of relational stalking

Annex to Quirke et al. Quality assurance in pathology in colorectal cancer screening and diagnosis: annotations of colorectal lesions

Multidisciplinary, evidence-based European Guidelines for quality assurance in colorectal cancer screening and diagnosis have recently been developed by experts in a pan-European project coordinated by the International Agency for Research on Cancer. The full guideline document includes a chapter on pathology with pan-European recommendations which take into account the diversity and heterogeneity of health care systems across the EU. The present paper is based on the annex to the pathology chapter which attempts to describe in greater depth some of the issues raised in the chapter in greater depth, particularly details of special interest to pathologists. It is presented here to make the relevant discussion known to a wider scientific audience

Human papillomavirus detected in female breast carcinomas in Japan

To investigate the aetiological role of human papillomavirus (HPV) in breast cancer, we examined the presence, genotype, viral load, and physical status of HPV in 124 Japanese female patients with breast carcinoma. Human papillomavirus presence was examined by PCR using SPF10 primers, and primer sets targeting the E6 region of HPV-16, -18, and -33. The INNO-LiPA HPV genotyping kit was used to determine genotype. Human papillomavirus DNA was detected in 26 (21%) breast carcinomas. The most frequently detected HPV genotype was HPV-16 (92%), followed by HPV-6 (46%), HPV-18 (12%), and HPV-33 (4%). In 11 normal epithelium specimens adjacent to 11 HPV-16-positive carcinomas, 7 were HPV-16-positive. However, none of the normal breast tissue specimens adjacent to HPV-negative breast carcinomas were HPV-positive. The real-time PCR analysis suggested the presence of integrated form of viral DNA in all HPV-16-positive samples, and estimated viral load was low with a geometric mean of 5.4 copies per 104 cells. In conclusion, although HPV DNA was detected in 26 (21%) breast carcinomas and, in all HPV-16-positive cases, the HPV genome was considered integrated into the host genome, their low viral loads suggest it is unlikely that integrated HPV is aetiologically involved in the development of Japanese breast carcinomas that we examined