High resolution study of associated C IV absorption systems in NGC 5548

We present the results of a careful analysis of associated absorption systems toward NGC 5548. Most of the well resolved narrow components in the associated system, defined by the Lyman alpha, C IV and N V profiles, show velocity separation similar (to within 10~\kms) to the C IV doublet splitting. We estimate the chance probability of occurrence of such pairs with velocity separation equal to C IV doublet splitting to be $6\times10^{-3}$. Thus it is more likely that most of the narrow components are line-locked with C IV doublet splitting. This will mean that the radiative acceleration plays an important role in the kinematics of the absorbing clouds. We build grids of photoionization models and estimate the radiative acceleration due to all possible bound-bound transitions. We show that the clouds producing absorption have densities less than $10^9 cm^{-3}$, and are in the outer regions of the broad emission line region (BLR). We note that the clouds which are line-locked cannot produce appreciable optical depths of O VII and O VIII, and hence cannot be responsible for the observed ionized edges, in the soft X-ray. We discuss the implications of the presence of optically thin clouds in the outer regions of the BLR to the models of broad emission lines.Comment: 21 pages, latex (aasms4 style), incluedes 4 ps figures. To appear in Astrophysical Journa

Dipolar ordering in Fe8?

We show that the low-temperature physics of molecular nanomagnets, contrary to the prevailing one-molecule picture, must be determined by the long-range magnetic ordering due to many-body dipolar interactions. The calculations here performed, using Ewald's summation, suggest a ferromagnetic ground state with a Curie temperature of about 130 mK. The energy of this state is quite close to those of an antiferromagnetic state and to a glass of frozen spin chains. The latter may be realized at finite temperature due to its high entropy.Comment: 7 pages, no figures, submitted to EP

External Parasites Attacking Swine in Texas.

2 p

How is Binary Radio-Pulsars with Black Holes Population Rich?

Using "Scenario Machine" we have carried out population synthesis of radio pulsar with black hole binaries (BH+Psr) in context of the most wide assumptions about star mass loss during evolution, binary stars mass ratio distribution, kick velocity and envelope mass lost during collapse. Our purpose is to display that under any suppositional parameters of evolution scenario BH+Psr population have to be abundant in Galaxy. It is shown that in the all models including models evolved by Heger et al. (2002), Woosley et al. (2002), Heger et al. (2003) expected number of the black holes paired with radio pulsars is sufficient enough to discover such systems within the next few years.Comment: 8 pages, 4 figures, accepted to MNRA

Regional simulation of bootstrap efficiency of broiler production in Peninsular Malaysia

Bootstrapping the DEA is one of the current methods of measuring robust efficiency by constructing a confidence interval and measuring the noise (bias) in production. In this study, two estimators: the conventional Data Envelopment Analysis (DEA) and bootstrap simulation with 2,000 bootstrap iterations were applied on a cross sectional data of 296 broiler farms in Peninsular Malaysia. The objective of the study was to measure the robust technical efficiency, production bias and factors motivating technical efficiency in the Northern, Southern, and East-central regions of Peninsular Malaysia. As a regional approach, the study found the existence of both inefficiency and noise in broiler farms across regions of Peninsular Malaysia. Findings show disease infestation and unfavorable temperature as components of noise or exogenous factors or factors beyond farmers’ control in broiler production. The study identified age (+), education (+), experience (+), production system (-), number of poultry farms owne d (-), business status (+) and land tenure status (-) as statistically significant in a meliorating efficiency in broiler production. Result also show that strong statistically significant differences exist in the magnitude of technical efficiency scores between the two estimators across the regions. The study advocate for increase in scale of production as majority of the farmers produce at increasing returns to scale

Understanding air release through air valves

[EN] Water transients with entrapped air can originate large pressure peaks that can severely damage distribution networks. Entrapped air can have a damping or amplifying effect on these undesirable pressure peaks. Unfortunately, the complexity of the phenomenon too often makes it difficult to obtain a fully reliable prediction about when air pockets will mitigate or accentuate water transients. Furthermore, the value of some of the parameters involved in the conventional numerical models cannot be calculated or measured and need to be determined through a calibration process. With the aim of overcoming most of the aforementioned uncertainties, this paper summarizes a complete set of tests conducted at WL | Delft Hydraulics. These tests were simulated by means of a tailored numerical model that includes a set of parameters whose values were determined by means of a calibration process. The experimental setup, a large-scale facility, consisted of a single steep pipeline with an air valve installed at its top end. Air release through different air valves was tested under different conditions. © 2011 American Society of Civil Engineers.This research has been possible thanks to the European Community Programme "Access to Major Research Infrastructure" under the Fifth Framework Growth Programme (Contract No. GIRT-CT-2002-05069).Carlos Alberola, MDM.; Arregui De La Cruz, F.; Cabrera Marcet, E.; Palau, C. (2011). Understanding air release through air valves. Journal of Urban Planning and Development. 137(4):461-469. doi:10.1061/(ASCE)HY.1943-7900.0000324S461469137

Uptake and transport of novel amphiphilic polyelectrolyte-insulin nanocomplexes by caco-2 cells - towards oral insulin

“The original publication is available at www.springerlink.com”. Copyright SpringerPurpose: The influence of polymer architecture on cellular uptake and transport across Caco-2 cells of novel amphiphilic polyelectrolyte-insulin nanocomplexes was investigated. Method: Polyallylamine (PAA) (15 kDa) was grafted with palmitoyl chains (Pa) and subsequently modified with quaternary ammonium moieties (QPa). These two amphiphilic polyelectrolytes (APs) were tagged with rhodamine and their uptake by Caco-2 cells or their polyelectrolyte complexes (PECs) with fluorescein isothiocyanate-insulin (FITC-insulin) uptake were investigated using fluorescence microscopy. The integrity of the monolayer was determined by measurement of transepithelial electrical resistance (TEER). Insulin transport through Caco-2 monolayers was determined during TEER experiments. Result: Pa and insulin were co-localised in the cell membranes while QPa complexes were found within the cytoplasm. QPa complex uptake was not affected by calcium, cytochalasin D or nocodazole. Uptake was reduced by co-incubation with sodium azide, an active transport inhibitor. Both polymers opened tight junctions reversibly where the TEER values fell by up to 35 % within 30 minutes incubation with Caco-2 cells. Insulin transport through monolayers increased when QPa was used (0.27 ngmL-1 of insulin in basal compartment) compared to Pa (0.14 ngmL-1 of insulin in basal compartment) after 2 hours. Conclusion: These APs have been shown to be taken up by Caco-2 cells and reversibly open tight cell junctions. Further work is required to optimise these formulations with a view to maximising their potential to facilitate oral delivery of insulin.Peer reviewe

A Spectroscopic Study of a Large Sample of Wolf-Rayet Galaxies

We analyze long-slit spectral observations of 39 Wolf-Rayet (WR) galaxies with heavy element mass fraction ranging over 2 orders of magnitude, from Zsun/50 to 2Zsun. Nearly all galaxies in our sample show broad WR emission in the blue region of the spectrum (the blue bump) consisting of an unresolved blend of N III 4640, C III 4650, C IV 4658 and He II 4686 emission lines. Broad C IV 5808 emission (the red bump) is detected in 30 galaxies. Additionally, weaker WR emission lines are identified, most often the N III 4512 and Si III 4565 lines, which have very rarely or never been seen and discussed before in WR galaxies. These emission features are characteristic of WN7-WN8 and WN9-WN11 stars respectively. We derive the numbers of early WC (WCE) and late WN (WNL) stars from the luminosities of the red and blue bumps, and the number of O stars from the luminosity of the Hbeta emission line. Additionally, we propose a new technique for deriving the numbers of WNL stars from the N III 4512 and Si III 4565 emission lines. This technique is potentially more precise than the blue bump method because it does not suffer from contamination of WCE and early WN (WNE) stars and nebular gaseous emission. The N(WR)/N(O+WR) ratio decreases with decreasing metallicity, in agreement with predictions of evolutionary synthesis models. The N(WC)/N(WN) ratios and the equivalent widths of the blue bump EW(4650) and of the red bump EW(5808) derived from observations are also in satisfactory agreement with theoretical predictions.Comment: 49 pages, 9 figures, to appear in Astrophys.

Ab-initio density-functional lattice-dynamics studies of ice

We present the results of first-principles computational studies of the dynamical properties of hexagonal ice using both the ab-initio pseudopotential method and the full-potential augmented plane-wave method. Properties obtained using both the generalized gradient approximation (GGA) and the meta-GGA in density-functional theory are compared. The lattice-dynamical properties of the structures are obtained using a finite-difference evaluation of the dynamical matrix and force-constant matrix from atomic forces. Phonon dispersion is evaluated by the direct determination of the force-constant matrix in supercells derived from the primitive molecule unit cells with the assumption that force constants are zero beyond the second molecular nearest neighbors. The k-dependent phonon frequencies are then obtained from the force-constant matrix and dispersion relations, and the Brillouin-zone integrated density of states is evaluated. The importance of phonon dispersion in the various regions of the phonon spectra is then assessed and compared to existing neutron-scattering data. Frozen-phonon calculations are used to compare phonon frequencies evaluated in both the GGA and meta-GGA

Ankle brachial index combined with Framingham risk score to predict cardiovascular events and mortality - A meta-analysis

CONTEXT: Prediction models to identify healthy individuals at high risk of cardiovascular disease have limited accuracy. A low ankle brachial index (ABI) is an indicator of atherosclerosis and has the potential to improve prediction. OBJECTIVE: To determine if the ABI provides information on the risk of cardiovascular events and mortality independently of the Framingham risk score (FRS) and can improve risk prediction. DATA SOURCES: Relevant studies were identified. A search of MEDLINE (1950 to February 2008) and EMBASE (1980 to February 2008) was conducted using common text words for the term ankle brachial index combined with text words and Medical Subject Headings to capture prospective cohort designs. Review of reference lists and conference proceedings, and correspondence with experts was conducted to identify additional published and unpublished studies. STUDY SELECTION: Studies were included if participants were derived from a general population, ABI was measured at baseline, and individuals were followed up to detect total and cardiovascular mortality. DATA EXTRACTION: Prespecified data on individuals in each selected study were extracted into a combined data set and an individual participant data meta-analysis was conducted on individuals who had no previous history of coronary heart disease. RESULTS: Sixteen population cohort studies fulfilling the inclusion criteria were included. During 480,325 person-years of follow-up of 24,955 men and 23,339 women, the risk of death by ABI had a reverse J-shaped distribution with a normal (low risk) ABI of 1.11 to 1.40. The 10-year cardiovascular mortality in men with a low ABI (< or = 0.90) was 18.7% (95% confidence interval [CI], 13.3%-24.1%) and with normal ABI (1.11-1.40) was 4.4% (95% CI, 3.2%-5.7%) (hazard ratio [HR], 4.2; 95% CI, 3.3-5.4). Corresponding mortalities in women were 12.6% (95% CI, 6.2%-19.0%) and 4.1% (95% CI, 2.2%-6.1%) (HR, 3.5; 95% CI, 2.4-5.1). The HRs remained elevated after adjusting for FRS (2.9 [95% CI, 2.3-3.7] for men vs 3.0 [95% CI, 2.0-4.4] for women). A low ABI (< or = 0.90) was associated with approximately twice the 10-year total mortality, cardiovascular mortality, and major coronary event rate compared with the overall rate in each FRS category. Inclusion of the ABI in cardiovascular risk stratification using the FRS would result in reclassification of the risk category and modification of treatment recommendations in approximately 19% of men and 36% of women. CONCLUSION: Measurement of the ABI may improve the accuracy of cardiovascular risk prediction beyond the FRS