Generalized conductance sum rule in atomic break junctions

When an atomic-size break junction is mechanically stretched, the total conductance of the contact remains approximately constant over a wide range of elongations, although at the same time the transmissions of the individual channels (valence orbitals of the junction atom) undergo strong variations. We propose a microscopic explanation of this phenomenon, based on Coulomb correlation effects between electrons in valence orbitals of the junction atom. The resulting approximate conductance quantization is closely related to the Friedel sum rule.Comment: 4 pages, 1 figure, appears in Proceedings of the NATO Advanced Research Workshop ``Size dependent magnetic scattering'', Pecs, Hungary, May 28 - June 1, 200

Ecological, evolutionary and human-mediated determinants of poeciliid species richness on Caribbean islands

Aim: The theory of island biogeography provides a predictive framework relating species richness to island size and distance from the mainland. However, the theory as originally formulated does not necessarily scale to large islands and continental landmasses that are capable of generating species through in situ speciation (rather than entirely by colonization), nor does it necessarily account for how human introduction of species alters traditional biogeographical patterns. Here, we examine the ecological (colonization and extinction), evolutionary (in situ speciation) and human-mediated (deliberate introductions) determinants of species richness in a taxonomic group that has undergone a radiation on Caribbean islands: live-bearing fishes of the family Poeciliidae. Location: The Caribbean. Methods: We created a database of both native and introduced poeciliid species occurrence on Caribbean islands through literature review, and estimated the number of colonizations versus speciation events on each island using a molecular phylogeny. Linear regression and other statistical tests were used to explore species–area and species–isolation relationships. Results: Species richness on small islands results entirely from colonization and does not significantly increase with island area, whereas on larger islands species richness increases dramatically as a function of area due primarily to in situ speciation. Poeciliid fishes have been introduced widely, both as a by-product of their popularity in the aquarium hobby and as a means of mosquito control. We show that such establishments have occurred disproportionately on islands depauperate in native species, and that introduced species richness is positively correlated with economic interconnectedness (shipping traffic) and human population size. Main conclusions: On large Caribbean islands in situ speciation has elevated the number of poeciliid species beyond that predicted from ecological processes alone. Introduced species significantly alter biogeographical patterns

MRSA eradication of newly acquired lower respiratory tract infection in cystic fibrosis

UK cystic fibrosis (CF) guidelines recommend eradication of methicillin-resistant Staphylococcus aureus (MRSA) when cultured from respiratory samples. As there is no clear consensus as to which eradication regimen is most effective, we determined the efficacy of eradication regimens used in our CF centre and long-term clinical outcome. All new MRSA positive sputum cultures (n=37) that occurred between 2000 and 2014 were reviewed. Eradication regimen characteristics and clinical, microbiological and long-term outcome data were collected. Rifampicin plus fusidic acid was the most frequently used regimen (24 (65%) out of 37 patients), with an overall success rate of 79% (19 out of 24 patients). Eradication failure was more likely in patients with an additional MRSA-positive peripheral screening swab (p=0.03) and was associated with worse survival (p=0.04). Our results demonstrate the feasibility and clinical benefits of MRSA eradication. As peripheral colonisation was associated with lower eradication success, strategies combining systemic and topical treatments should be considered to optimise outcomes in CF patients

Origin of Frontal Lobe Spikes in the Early Onset Benign Occipital Lobe Epilepsy (Panayiotopoulos Syndrome)

Objective: Early onset benign occipital lobe epilepsy (Panayiotopoulos syndrome [PS]) is a common and easily recognizable epilepsy. Interictal EEG spike activity is often multifocal but most frequently localized in the occipital lobes. The origin and clinical significance of the extra-occipital spikes remain poorly understood. Methods: Three patients with the PS and interictal EEG spikes with frontal lobe topography were studied using high-resolution EEG. Independent component analysis (ICA) was used to decompose the spikes in components with distinct temporal dynamics. The components were mapped in the scalp with a spline-laplacian algorithm. Results: The change in scalp potential topography from spike onset to peak, suggests the contribution of several intracranial generators, with different kinetics of activation and significant overlap. ICA was able to separate the major contributors to frontal spikes and consistently revealed an early activating group of components over the occipital areas in all the patients. The local origin of these early potentials was established by the spline-laplacian montage. Conclusions: Frontal spikes in PS are consistently associated with early and unilateral occipital lobe activation, suggesting a posteroanterior spike propagation. Significance: Frontal spikes in the PS represent a secondary activation triggered by occipital interictal discharges and do not represent an independent focus

The Epidemiological features of lymphoid malignancies in Benin City, Nigeria: a 15 years study

Introduction: Lymphoid malignancies compose a wide spectrum of different morphologic and clinical syndromes known to vary widely throughout the world. The purpose of this study is to determine the prevalence and time trends of lymphoid malignancies. Methods: A 15 (May 1st 1996-April 30th 2010) years study of all patients who had lymph node biopsy at the Department of Haematology and Pathology, University of Benin Teaching Hospital, Benin City, Nigeria. Results: The 391 patients had a male preponderance (M:F; 1.6:1). An increase in the lymphoid malignant cases was noted from 95 cases in the first 5-year interval (1996-2000) to 179 cases in the last 5-year interval (2006-2010) giving an average increase of 84.0%. Non-Hodgkins lymphoma (61.1%) and chronic lymphocytic leukaemia (18.2%) were the most frequent followed by Hodgkin’s lymphoma and myeloma with equal proportions of 9.0% each. A positive correlation with a significant linear trends was obtained (r=0.1949, p<0.0001). Geographic areas at risk were found mainly in patients residing in Delta State (67.0%) which is a major oil producing state and Edo State (30.4%) where the hospital is located, both in the Niger Delta Region of Nigeria. Conclusion: Future research into environmental agents and genetic makeup/HLA typing of patients can be carried out

Overshoot inwards from the bottom of the intershell convective zone in (S)AGB stars

We estimate the extent of overshooting inwards from the bottom of the intershell convective zone in thermal pulses in (S)AGB stars. We find that the buoyancy is so strong that any overshooting should be negligible. The temperature inversion at the bottom of the convective zone adds to the stability of the region. Any mixing that occurs in this region is highly unlikely to be due to convective overshooting, and so must be due to another process

Kidney Function Status in Nigerian Human Malaria Patients

Malaria is now known to affect over 500 million persons worldwide, killing about 1 to 3 million of them annually. Plasmodium falciparum is the  species mostly implicated in the causation of severe malaria. This study was carried out to investigate the kidney function status of malaria patients in Benin metropolis, Southern Nigeria, to ascertain if there is renal  dysfunction/impairment in them. Plasma levels of sodium, potassium,  bicarbonate, urea, creatinine and blood urea nitrogen (BUN) were assayed in a total of 152 subjects (112 malaria patients infected with Plasmodium falciparum and 40 controls) of both sexes, with their age ranging from 8 to 42 years. The results observed irrespective of age or sex, reveal a  statistically significant (p<0.05) increase in plasma levels of potassium, urea, BUN and creatinine (4.49±0.95 mmol/L;5.88±0.13mmol /L;16.39±0.36mg/dl and 135.05±2.69ìmol/L) when compared to their controls (4.05±0.34mmol/L;3.73±0.12mmol/L;10.34±0.36mg/dl and  80.71±1.69ìmol/L, respectively) and also a statistically significant (P<0.05) reduction in plasma levels of Na+ and HC03- (128.50±0.77 and  19.98±0.28mmol/L) when compared to their controls (l38.58±0.29 and 24.70±0.36mmol/L, respectively). The hyponatraemia and metabolic acidosis observed in the malaria patients are negatively correlated with the degree of parasitaemia (r=-0.241 and r=-0.019, respectively), while the elevated plasma potassium and creatinine levels are positively correlated with the degree of parasitaemia (r=0.153 and r=0.407, respectively). The elevated plasma Urea and BUN levels are also positively correlated with the degree of parasitaemia (r=0.371 and r=0.375, respectively). The results of this study indicate that there is significant renal dysfunction/impairment in patients in southern Nigeria infected with plasmodium falciparum.Keywords: Malaria infection, Kidney function status

Erlotinib as salvage treatment after failure to first-line Gefitinib in non-small cell lung cancer

Purpose Chemotherapy is the mainstay treatment for advanced non-small cell lung cancer (NSCLC). Gefitinib, an epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI), has been recently shown to be effective as a first-line treatment in Asian patients with advanced NSCLC, especially for those with favourable clinical features such as female, non-smoker and adenocarcinoma. However, resistance to gefitinib ensues invariably and there is little evidence as for the effectiveness of subsequent salvage treatment. The purpose of this study is to evaluate the efficacy of erlotinib, another EGFR-TKI, after failed first-line use of gefitinib. Method Retrospective review of NSCLC patients with favourable clinical features who received gefitinib as firstline treatment and subsequent salvage treatment with erlotinib. Results A total of 21 patients with NSCLC were included in the study. Among them, 18 (85.7%) patients had disease control with gefitinib and 12 (57.1%) patients with salvage erlotinib. There was an association between the disease control with gefitinib and erlotinib (p = 0.031). The disease control rate of erlotinib was independent of the chemotherapy use between the two EGFR-TKIs. Conclusion For NSCLC patients with favourable clinical features, erlotinib was effective in those who had prior disease control with first-line gefitinib. © Springer-Verlag 2009.published_or_final_versionSpringer Open Choice, 01 Dec 201

Relationship between tissue retention efficiency and production traits in a slow-growing broiler population

An experiment was conducted using 96 individually caged male broilers between 49 and 77 d of age. One objective was to establish phenotypic relationships between some production traits [feed conversion ratio (FCR), feed consumption, residual feed consumption (RFC), relative weight gain (RWG), weight gain (WG) and live weight (LW)] and “tissue retention efficiency” (TRE) traits in a slow-growing broiler population. The other objective was the characterization of Campero-INTA broilers for TRE traits. Weight and feed consumption were recorded weekly. Forty four broilers were slaughtered at 44 d of age to estimate initial body composition while the remaining birds were slaughtered at 79 d of age. Ether extract and crude protein content of the carcasses were used to estimate TRE traits: Energy retained as protein (ERP), energy retained as fat (ERF), ERP/(ERP+ERF), ERF/(ERP+ERF), protein retention efficiency and lipid-protein ratio. Correlation coefficients between traits were obtained and regression analyses were done for the evaluation of the influence of production traits on TRE traits. The independent variable that best explained ERF was WG (R2 = 0.49). Inclusion of final LW and RWG raised the R2 to 0.58 and decreased the error term. The ERP was best explained by RWG (R2 = 0.37); lipid-protein ratio by final LW (R2 = 0.49); protein retention efficiency by FCR (R2 = 0.34) and fraction of retained energy (ERF-ERP/ERP+ERF) by WG (R2 = 0.29). The TRE traits were not well predicted by the measured production traits. The high phenotypic variability observed in some of the TRE traits suggested a need for further studies on these characteristics. Keywords: Broiler; tissue retention; efficiency; slow-growing stock South African Journal of Animal Science Vol. 37 (3) 2007: pp.164-16

Podoplanin-positive cancer cells at the edge of esophageal squamous cell carcinomas are involved in invasion

Podoplanin (PDPN) is a well established lymphatic endothelial marker and has frequently been observed in cancer cells at the edge of cancer masses. Previous studies investigating the association between PDPN expression and patient prognosis have had contradictory results. In the present study, it was hypothesized that the different locations of PDPNpositive cells may explain these varying results. The present study aimed to focus on PDPN expression at the edge of esophageal cancer cell nests. In order to analyze the clinical significance of this PDPN expression, immunohistochemistry was performed using esophageal cancer tissue microarrays. PDPN expression at the edge of the cancer cell nest was found to be significantly associated with invasion (P<0.05) and poor prognosis (P<0.001) in patients with cancer. To further investigate the role of PDPN expression in cancer cells, the PDPN gene was cloned and transfected into esophageal squamous cell carcinoma (ESCC) cell lines. PDPN expression was also knocked down using small interfering RNA. PDPNpositive cancer cells were found to exhibit invasion characteristics. Thus, PDPN expression at the edge of a cancer cell nest may indicate invasion and represent a poor prognostic factor for ESCCs.published_or_final_versio