bluuebunny/crossref_metadata_2025 huggingface dataset:
Informality and Openness to Trade: Insights from Cross-sectional and Panel Analyses
Authors: Fiess Norbert , Fugazza Marco
Published: May 2012

The relationship between trade liberalisation and informal activity has received little theoretical and empirical attention. The conventional view poses that trade liberalisation would cause a rise in the share of informal production and a rise in informal employment. This article uses three different datasets to assess econometrically the sign of these relationships. Empirical results suggest that while informal output increases with deeper openness to trade, informal employment falls.

JEL Classification: F13, F16, O17, C23
UNIFIES - a model to aid in the successful introduction of infection prevention and control innovations and improvements
Authors: Jeanes Annette
Published: May 2012

A model was developed by an infection control department to assist in the delivery of change and innovations in a challenging and complex organisation. It was entitled UNIFIES and was based on the experience gained on previous projects to introduce and sustain changes in practice. The methodology and application included lean systems and social marketing principles. The model takes into account the requirement for leadership, teamwork and time to participate. The use of metrics to determine progress, success, failure and lessons learnt are a keys aspect of the model.
IgG opsonization of bacteria promotes Th17 responses via synergy between TLRs and FcγRIIa in human dendritic cells
Authors: den Dunnen Jeroen , Vogelpoel Lisa T. C. , Wypych Tomasz , Muller Femke J. M. , de Boer Leonie , Kuijpers Taco W. , Zaat Sebastiaan A. J. , Kapsenberg Martien L. , de Jong Esther C.
Published: May 2012

Dendritic cells (DCs) are essential in inducing adaptive immune responses against bacteria by expressing cytokines that skew T-cell responses toward protective Th17 cells. Although it is widely recognized that induction of these cytokines by DCs involves activation of multiple receptors, it is still incompletely characterized which combination of receptors specifically skews Th17-cell responses. Here we have identified a novel role for FcγRIIa in promoting human Th17 cells. Activation of DCs by bacteria opsonized by serum IgG strongly promoted Th17 responses, which was FcγRIIa-dependent and coincided with enhanced production of selected cytokines by DCs, including Th17-promoting IL-1β and IL-23. Notably, FcγRIIa stimulation on DCs did not induce cytokine production when stimulated individually, but selectively amplified cytokine responses through synergy with TLR2, 4, or 5. Importantly, this synergy is mediated at 2 different levels. First, TLR-FcγRIIa costimulation strongly increased transcription of pro-IL-1β and IL-23p19. Second, FcγRIIa triggering induced activation of caspase-1, which cleaves pro-IL-1β into its bioactive form and thereby enhanced IL-1β secretion. Taken together, these data identified cross-talk between TLRs and FcγRIIa as a novel mechanism by which DCs promote protective effector Th17-cell responses against bacteria.
From famine to feast: sending out the clones
Authors: Glaubach Taly , Corey Seth J.
Published: May 2012

In this issue of Blood, Beekman et al provide compelling evidence for the multistep evolution of acute myeloid leukemia (AML) from severe congenital neutropenia (SCN) over a 17-year period. Moreover, they found that 5 different gain-of-function mutations in the granulocyte colony-stimulating factor receptor (GCSFR) arose during this transformation, suggesting that 2 mutations behaved as drivers for clonal outgrowth, while 3 others did not.1
“Burden of osteoporotic fractures in primary health care in Catalonia (Spain): a population-based study”
Authors: Pagès-Castellà Aina , Carbonell-Abella Cristina , Avilés Francesc Fina , Alzamora Maite , Baena-Díez Jose Miguel , Laguna Daniel Martínez , Nogués Xavier , Díez-Pérez Adolfo , Prieto-Alhambra Daniel
Published: May 2012

Background

Knowledge on the epidemiology of non-hip fractures in Spain is limited and somewhat outdated. Using computerized primary care records from the SIDIAP database, we derived age and sex-specific fracture incidence rates for the region of Catalonia during the year 2009.

Methods

The SIDIAP database contains quality-checked clinical information from computerized medical records of a representative sample of >5,800,000 patients (80% of the population of Catalonia). We conducted a retrospective cohort study including all patients aged ≥50 years, and followed them from January 1 to December 31, 2009. Major osteoporotic fractures registered in SIDIAP were ascertained using ICD-10 codes and validated by comparing data to hospital admission and patient-reported fractures records. Incidence rates and 95% confidence intervals were calculated.

Results

In total, 2,011,430 subjects were studied (54.6% women). Overall fracture rates were 10.91/1,000 person-years (py) [95%CI 10.89–10.92]: 15.18/1,000 py [15.15–15.21] in women and 5.78/1,000 py [5.76–5.79] in men. The most common fracture among women was wrist/forearm (3.86/1,000 py [3.74–3.98]), while among men it was clinical spine (1.25/1,000 py [1.18–1.33]). All fracture rates increased with age, but varying patterns were observed: while most of the fractures (hip, proximal humerus, clinical spine and pelvis) increased continuously with age, wrist and multiple rib fractures peaked at age 75–80 and then reached a plateau.

Conclusions

Our study provides local estimates of age, sex and site-specific fracture burden in primary health care, which will be helpful for health-care planning and delivery. A proportion of fractures are not reported in primary care records, leading to underestimation of fracture incidence rates in these data.
Aboriginal Health Workers experience multilevel barriers to quitting smoking: a qualitative study
Authors: Dawson Anna P , Cargo Margaret , Stewart Harold , Chong Alwin , Daniel Mark
Published: May 2012

Introduction

Long-term measures to reduce tobacco consumption in Australia have had differential effects in the population. The prevalence of smoking in Aboriginal peoples is currently more than double that of the non-Aboriginal population. Aboriginal Health Workers are responsible for providing primary health care to Aboriginal clients including smoking cessation programs. However, Aboriginal Health Workers are frequently smokers themselves, and their smoking undermines the smoking cessation services they deliver to Aboriginal clients. An understanding of the barriers to quitting smoking experienced by Aboriginal Health Workers is needed to design culturally relevant smoking cessation programs. Once smoking is reduced in Aboriginal Health Workers, they may then be able to support Aboriginal clients to quit smoking.

Methods

We undertook a fundamental qualitative description study underpinned by social ecological theory. The research was participatory, and academic researchers worked in partnership with personnel from the local Aboriginal health council. The barriers Aboriginal Health Workers experience in relation to quitting smoking were explored in 34 semi-structured interviews (with 23 Aboriginal Health Workers and 11 other health staff) and 3 focus groups (n = 17 participants) with key informants. Content analysis was performed on transcribed text and interview notes.

Results

Aboriginal Health Workers spoke of burdensome stress and grief which made them unable to prioritise quitting smoking. They lacked knowledge about quitting and access to culturally relevant quitting resources. Interpersonal obstacles included a social pressure to smoke, social exclusion when quitting, and few role models. In many workplaces, smoking was part of organisational culture and there were challenges to implementation of Smokefree policy. Respondents identified inadequate funding of tobacco programs and a lack of Smokefree public spaces as policy level barriers. The normalisation of smoking in Aboriginal society was an overarching challenge to quitting.

Conclusions

Aboriginal Health Workers experience multilevel barriers to quitting smoking that include personal, social, cultural and environmental factors. Multidimensional smoking cessation programs are needed that reduce the stress and burden for Aboriginal Health Workers; provide access to culturally relevant quitting resources; and address the prevailing normalisation of smoking in the family, workplace and community.
Group I mGluR antagonist rescues the deficit of D1-induced LTP in a mouse model of fragile X syndrome
Authors: Xu Zhao-Hui , Yang Qi , Feng Bin , Liu Shui-bing , Zhang Nan , Xing Jiang-hao , Li Xiao-Qiang , Wu Yu-mei , Gao Guo-Dong , Zhao Ming-Gao
Published: May 2012

Background

Fragile X syndrome (FXS) is caused by the absence of the mRNA-binding protein Fragile X mental retardation protein (FMRP), encoded by the Fmr1 gene. Overactive signaling by group 1 metabotropic glutamate receptor (Grp1 mGluR) could contribute to slowed synaptic development and other symptoms of FXS. Our previous study has identified that facilitation of synaptic long-term potentiation (LTP) by D1 receptor is impaired in Fmr1 knockout (KO) mice. However, the contribution of Grp1 mGluR to the facilitation of synaptic plasticity by D1 receptor stimulation in the prefrontal cortex has been less extensively studied.

Results

Here we demonstrated that DL-AP3, a Grp1 mGluR antagonist, rescued LTP facilitation by D1 receptor agonist SKF81297 in Fmr1KO mice. Grp1 mGluR inhibition restored the GluR1-subtype AMPA receptors surface insertion by D1 activation in the cultured Fmr1KO neurons. Simultaneous treatment of Grp1 mGluR antagonist with D1 agonist recovered the D1 receptor signaling by reversing the subcellular redistribution of G protein-coupled receptor kinase 2 (GRK2) in the Fmr1KO neurons. Treatment of SKF81297 alone failed to increase the phosphorylation of NR2B-containing N-methyl D-aspartate receptors (NMDARs) at Tyr-1472 (p-NR2B-Tyr1472) in the cultures from KO mice. However, simultaneous treatment of DL-AP3 could rescue the level of p-NR2B-Tyr1472 by SKF81297 in the cultures from KO mice. Furthermore, behavioral tests indicated that simultaneous treatment of Grp1 mGluR antagonist with D1 agonist inhibited hyperactivity and improved the learning ability in the Fmr1KO mice.

Conclusion

The findings demonstrate that mGluR1 inhibition is a useful strategy to recover D1 receptor signaling in the Fmr1KO mice, and combination of Grp1 mGluR antagonist and D1 agonist is a potential drug therapy for the FXS.
Peripheral blood lymphocytes from low-grade squamous intraepithelial lesions patients recognize vaccine antigens in the presence of activated dendritic cells, and produced high levels of CD8 + IFNγ + T cells and low levels of IL-2 when induced to proliferate
Authors: Hernández-Montes Jorge , Rocha-Zavaleta Leticia , Monroy-García Alberto , Weiss-Steider Benny , Zaragoza-Ortega María del Carmen , Cruz-Talonia Fernando , Cruz Omar Cruz y , Bonifaz-Alfonso Laura , Chávez-Rueda Adriana Karina , Rojo-Aguilar Martha Patricia , Legorreta-Haquet María Victoria , Mora-García María de Lourdes
Published: May 2012

Background

Most infections with human papillomavirus (HPV) are resolved without clinical intervention, but a minority evolves into chronic lesions of distinct grades, including cervical-uterine cancer. It is known that in most cases the immune system mediates elimination of HPV infection. However, the mechanism of immune evasion leading to HPV persistence and development of early cervical lesions is not fully understood. The aim of the present work was to evaluate the potential of peripheral blood leukocytes (PBL) from low-grade squamous intraepithelial lesions (LSIL) patients to be activated ex-vivo by vaccine antigens, the participation of cytotoxic lymphocytes and regulatory T cells, and to determine the secretion of Th1 and Th2 cytokines mediated by stimulation of T cell receptors.

Results

We found that PBL from LSIL patients showed a significantly lower proliferation rate to vaccine antigens as compared to that of healthy donors, even though there was not a difference in the presence of antibodies to those antigens in sera from both groups. We did not find differences in either the frequency of CD4 + CD25 + FoxP3+ in PBL, or the levels of IL-4, IL-5 and IL-10 in plasma or conditioned media from PBL incubated with TcR agonists in vitro, between the two groups. However, we detected a lower production of IL-2 and a higher proportion of CD8 + IFNγ + cells in PBL from LSIL patients as compared with PBL from normal donors. We also observed that PBL from patients infected by HPV-16 and −18 were not able to proliferate in the presence of soluble HPV antigens added to the culture; however, a high level of proliferation was attained when these antigens were presented by activated dendritic cells.

Conclusions

Our results suggest that the immunodeficiency reported in LSIL patients could be due to the inability of specific cytotoxic T lymphocytes that for some unknown reason are present but unable to mount a response when challenged with their antigens, probably related to an in situ IL-2 production deficiency.
Elevated serum leptin levels in patients with acute myocardial infarction; correlation with coronary angiographic and echocardiographic findings
Authors: Khafaji Hadi AR Hadi , Bener Abdul Bari , Rizk Nasser M , Al Suwaidi Jassim
Published: May 2012

Background

To assess the relationship between serial serum leptin levels in patients with acute myocardial infarction (AMI) who received thrombolysis and the degree of coronary atherosclerosis, coronary reperfusion, echocardiographic findings, and clinical outcome. 51 consecutive patients presenting with AMI were studied. Clinical characteristics including age, sex, body mass index (BMI) and cardiovascular risk factors were recorded. Serial serum leptin levels at the time of admission and subsequently at 0, 6, 12, 24, 36, 60 hours afterwards were obtained. Coronary angiography was performed in 34 patients; the relation between serum leptin levels and evidence of coronary reperfusion as well as the extent of coronary atherosclerosis according to the coronary artery surgery study classification (CASS) were evaluated. Echocardiographic evaluation was performed in all patients. 36 matched patients were enrolled as control group who had serum leptin level 9.4 ± 6.5 ng/ml.

Results

The patients mean age was 50.5 ± 10.6 years. There were 47 males and 3 females. 37.1% were diabetics, 23.5% were hypertensive, 21.6% were dyslipidemic and 22.7% were obese (BMI ≥ 30). Leptin concentrations (ng/ml) increased and peaked at the 4th sample (36 hrs) after admission (mean ± SD) sample (1) =9.55 ± 7.4, sample (2) =12.9 ± 8.4, sample (3) =13.8 ± 10.4, sample (4) =18.9 ± 18.1, sample (5) =11.4 ± 6.5, sample (6) =10.8 ± 8.9 ng/ml. There was a significant correlation between serum leptin and BMI (r = 0.342; p = 0.03). Leptin levels correlated significantly to creatine kinase level on the second day (r = 0.43, p ≤ 0.01). Significant correlation of mean serum leptin with the ejection fraction (P < 0.05) was found. No difference in timing of peak serum leptin between patients who achieved coronary reperfusion vs. those who did not (p = 0.8). There was a trend for an increase in the mean serum leptin levels with increasing number of diseased vessels. There was no correlation between serum leptin levels and outcome neither during the hospitalization nor at 9 months follow up.

Conclusion

Serum leptin levels increase after myocardial infarction. Serum leptin level may be a predictor of the left ventricular ejection fraction and the degree of atherosclerosis but not of coronary reperfusion.
Erratum to: A whole genome association study of mother-to-child transmission of HIV in Malawi
Authors: Joubert Bonnie R , Lange Ethan M , Franceschini Nora , Mwapasa Victor , North Kari E , Meshnick Steven R ,   the NIAID Center for HIV/AIDS Vaccine Immunology
Published: May 2012

A correction to: Bonnie R Joubert, Ethan M Lange, Nora Franceschini, Victor Mwapasa, Kari E North, Steven R Meshnick andthe NIAID Center for HIV/AIDS Vaccine Immunology. A whole genome association study of mother-to-child transmission of HIV in Malawi. Genome Medicine 2010, 2:17.
Laser-Induced Acoustic Desorption Mass Spectrometry
Authors: Dow Alex R. , Wittrig Ashley M. , Kenttämaa Hilkka I.
Published: May 2012

Large thermally labile molecules were not amenable to mass spectrometric analysis until the development of atmospheric pressure evaporation/ionization methods, such as electrospray ionization (ESI) and matrix-assisted laser desorption/ionization (MALDI), since attempts to evaporate these molecules by heating induces degradation of the sample. While ESI and MALDI are relatively soft desorption/ionization techniques, they are both limited to preferential ionization of acidic and basic analytes. This limitation has been the driving force for the development of other soft desorption/ionization techniques. One such method employs laser-induced acoustic desorption (LIAD) to evaporate neutral sample molecules into mass spectrometers. LIAD utilizes acoustic waves generated by a laser pulse in a thin metal foil. The acoustic waves travel through the foil and cause desorption of neutral molecules that have been deposited on the opposite side of the foil. One of the advantages of LIAD is that it desorbs low-energy molecules that can be ionized by a variety of methods, thus allowing the analysis of large molecules that are not amenable to ESI and MALDI. This review covers the generation of acoustic waves in foils via a laser pulse, the parameters affecting the generation of acoustic waves, possible mechanisms for desorption of neutral molecules, as well as the various uses of LIAD by mass spectrometrists. The conditions used to generate acoustic or stress waves in solid materials consist of three regimes: thermal, ablative and constrained. Each regime is discussed, in addition to the mechanisms that lead to the ablation of the metal from the foil and generation of acoustic waves for two of the regimes. Previously proposed desorption mechanisms for LIAD are presented, along with the flaws associated with some of them. Various experimental parameters, such as the exact characteristics of the laser pulse and foil used, are discussed. The internal energy and velocities of the neutral desorbed molecules are also considered. Our research group has been instrumental in the development and use of LIAD. For example, we have systematically examined the influence of many parameters, such as the type of the foil and its thickness, as well as the thickness of the analyte layer, on the efficiency of desorption of neutral molecules. The coupling of LIAD with different instruments and ionization techniques allows for broad use of LIAD in our research laboratories. The most important applications involve analytes that cannot be analyzed by using other mass spectrometric methods, such as large saturated hydrocarbons and heavy hydrocarbon fractions of petroleum. We also use LIAD to characterize lipids, peptides and oligonucleotides. Fundamental research on the reactions of charged mono-, bi- and polyradicals with biopolymers, especially oligonucleotides, also requires the use of LIAD, as well as thermochemical measurements for neutral biopolymers. These are but a few of the uses of LIAD in our research group.
Concomitant Hydride and Proton Transfer: An Essay on Competing and Consecutive Key Reactions Occurring in Gaseous Ion/Neutral Complexes
Authors: Kuck Dietmar
Published: May 2012

The interplay of proton transfer and hydride transfer reactions in alkylbenzenium ions and related protonated di- and oligophenylalkanes is presented and discussed. While intra- and inter-annular proton exchange has been recognised to be a ubiquitous feature in protonated arenes, hydride abstraction is much less obvious but can become a dominating fragmentation channel in metastable ions of tert-butyl-substituted alkylbenzenium ions and related carbocations. In such cases, proton-induced release of the tert-butyl cation gives rise to ion/neutral complexes as reactive intermediates, for example, [(CH3)3C+ ṫ arylCH2α(CH2) nCH2ωaryl ′] with n ⩾ 0 and highly regioselective intra-complex hydride transfer occurs from all of the benzylic methylene hydride ion donor groups (α-CH2 and ω-CH2) to the tert-butyl cation acting as a Lewis acid. Substituent effects on the individual contributions to the overall hydride transfer from different donor sites, including ortho-methyl groups, in particular, and the concomitant intra-complex proton transfer from the tert-butyl cation to the neutral diarylalkane constituent corroborate the view of “bisolvated” complexes as the central intermediates, in which the carbenium ion is coordinated to both of the aromatic π-electron systems. The role of cyclisation processes, converting the benzylic [M – H]+-type ions into the isomeric benzenium, [M + H]+-type ions prior to fragmentation, is demonstrated for several cases. This overall scenario, consisting of consecutive and/or competing intra-complex hydride abstraction and proton transfer, intra-annular proton shifts (H+ ring walk) and interannular proton transfer, hydrogen exchange (“scrambling”) processes, and cyclisation and other electrophilic substitution reactions, is of general importance in this field of gas-phase ion chemistry and more recent examples concerning protonated ethers, benzylpyridinium and benzylammmonium ions are discussed in which these recurring features play central and concerted mechanistic roles as well.
High-resolution computed tomography findings of swine-origin influenza A (H1N1) virus (S-OIV) infection: comparison with scrub typhus
Authors: Jo Bang Sil , Lee In Jae , Im Hyoung June , Lee Kwanseop
Published: May 2012

Background

Swine-origin influenza A (H1N1) virus (S-OIV) infection and scrub typhus, also known as tsutsugamushi disease can manifest as acute respiratory illnesses, particularly during the late fall or early winter, with similar radiographic findings, such as a predominance of ground-glass opacity (GGO).

Purpose

To differentiate S-OIV infection from scrub typhus using high-resolution computed tomography (HRCT).

Material and Methods

We retrospectively reviewed the HRCT findings of 14 patients with S-OIV infection and 10 patients with scrub typhus. We assessed the location, cross-sectional distribution, and the presence of a peribronchovascular distribution of GGO and consolidations on HRCT. We also assessed the presence of interlobular septal thickening, bronchial wall thickening, pneumothorax, pneumomediastinum, pleural effusion, and mediastinal or axillary lymph node enlargement.

Results

Scrub typhus was more common than S-OIV in elderly patients ( P < 0.001). The monthly incidences of S-OIV and scrub typhus infection reached a peak between October and November. About 86% of S-OIV patients and 80% of scrub typhus patients presented with GGO. About 67% of the GGO lesions in S-OIV had a peribronchovascular distribution, but this was absent in scrub typhus ( P = 0.005). Consolidation (93% vs. 10%, P < 0.001) and bronchial wall thickening (43% vs. 0%, P = 0.024) were more frequent in S-OIV infection than scrub typhus. Interlobular septal thickening (90% vs. 36%, P = 0.013) and axillary lymphadenopathy (90% vs. 0%, P < 0.001) were more common in scrub typhus than S-OIV infection.

Conclusion

There was considerable overlap in HRCT findings between S-OIV infection and scrub typhus. However, S-OIV showed a distinctive peribronchovascular distribution of GGO lesions. Consolidation and bronchial wall thickening were seen more frequently in S-OIV infection, whereas interlobular septal thickening and axillary lymphadenopathy were more common in scrub typhus. Thus, CT could be helpful for differential diagnosis between S-OIV infection and scrub typhus.
Prevalence of extravertebral cement leakage after vertebroplasty: procedural documentation versus CT detection
Authors: Martin Douglas J , Rad Arash Ehteshami , Kallmes David F
Published: May 2012

Background

Reported incidence of extravertebral cement leakage after vertebroplasty varies widely across studies.

Purpose

To retrospectively compare the relative detection rates of extravertebral leakage noted under intra-procedural fluoroscopic surveillance, postprocedure plain radiographs, and postprocedure computed tomography (CT) in a cohort of patients undergoing vertebroplasty.

Material and Methods

With IRB approval, we retrospectively identified 181 patients with 277 levels treated with percutaneous vertebroplasty among a total of 1255 patients undergoing vertebroplasty between 1999 and 2010 who had subsequently undergone a CT examination that included the treated level(s). Categories of leakage were paravertebral, end plate, epidural, and prevertebral venous leakage. CT-detected leak rates were then compared to those noted on the vertebroplasty procedure reports and the archived fluoroscopic images for this same cohort using Pearson's χ2 test.

Results

One hundred and forty-nine (82%, 95% CI 76–87%) of 181 patients demonstrated evidence of some type of leakage on CT at one or more treated levels. Sixty-two (34%, 95% CI 28–42%) and seventy-seven (50%, 95% CI 43–57%) of 149 CT-detected leaks were reported in the procedural dictation or detected on plain radiography ( P = 0.01 and 0.006, respectively). The most common type of leakage noted on CT was end plate ( n = 81, 45%, 95% CI 38–52%), followed by paravertebral ( n = 64, 35%, 95% CI 29–43%), epidural ( n = 36, 20%, 95% CI 15–26%), and prevertebral venous ( n = 32, 18%, 95% CI 13–24%).

Conclusion

Cement leakage after vertebroplasty is common and is often not reported by operators in procedural dictations. CT detects substantially more leaks than plain radiography.
The Spread of the Sooro
Authors: Delancey Mark D.
Published: May 2012

The Sooro, the pillared entrance hall to the majority of palaces now existing in northern Cameroon, is an important index of political change in this region. The Spread of the Sooro: Symbols of Power in the Sokoto Caliphate traces the proliferation of sooroji from the time that Fulbe conquerors incorporated this region within the Sokoto caliphate in the early nineteenth century until Cameroon’s independence in 1960. The status of Fulbe rulers who conquered the region was not high enough to employ the political symbolism of the sooro, but the use of this building type spread quickly after German colonial borders separated northern Cameroon from the rest of the caliphate in 1901. Eventually the form expanded beyond the boundaries of the Fulbe and spread among non-Fulbe rulers. By explaining the changes in the form and political symbolism of the sooro, Mark DeLancey argues that it was a symbol of power spread in direct relation to the loss of real political power of rulers in colonial northern Cameroon.
Fluctuations of Fitness Distributions and the Rate of Muller’s Ratchet
Authors: Neher Richard A , Shraiman Boris I
Published: May 2012

The accumulation of deleterious mutations is driven by rare fluctuations that lead to the loss of all mutation free individuals, a process known as Muller’s ratchet. Even though Muller’s ratchet is a paradigmatic process in population genetics, a quantitative understanding of its rate is still lacking. The difficulty lies in the nontrivial nature of fluctuations in the fitness distribution, which control the rate of extinction of the fittest genotype. We address this problem using the simple but classic model of mutation selection balance with deleterious mutations all having the same effect on fitness. We show analytically how fluctuations among the fittest individuals propagate to individuals of lower fitness and have dramatically amplified effects on the bulk of the population at a later time. If a reduction in the size of the fittest class reduces the mean fitness only after a delay, selection opposing this reduction is also delayed. This delayed restoring force speeds up Muller’s ratchet. We show how the delayed response can be accounted for using a path-integral formulation of the stochastic dynamics and provide an expression for the rate of the ratchet that is accurate across a broad range of parameters.
Simulation of space charge limited organic non volatile memory elements
Authors: Santoni Francesco , Gagliardi Alessio , Di Carlo Aldo
Published: May 2012

We present a model for organic bistable devices (OBDs) embedded with metallic nanoparticles. In particular, two device architectures have been studied: a single layer device with metallic nanoparticles dispersed in a organic material matrix and a three layer device where two organic material regions are separated by a layer of heavy packed nanoparticles. The model describes the different behavior, the internal charge and potential distributions in the ON-OFF states. The OFF state is represented by charged nanoparticles forming a space charge layer which limits the current. The ON state occurs with neutral nanoparticles.
Resistive Switching Memory Based on Ferroelectric Polarization Reversal at Schottky-like BiFeO3 Interfaces
Authors: Tsurumaki-Fukuchi Atsushi , Yamada Hiroyuki , Sawa Akihito
Published: May 2012

We have fabricated a ferroelectric resistive switching device of Pt/Bi1-δFeO3 (BFO)/SrRuO3 (SRO) in which the conductivity of BFO layer was controlled by changing the Bi-deficiency concentration. The devices showed a bipolar-type resistive switching effect, i.e., zero-crossing hysteretic current–voltage (I–V) characteristics. In addition, the I–V characteristics in both high and low resistance states are nonlinear, which can avoid a read-error problem in a passive crossbar memory array. Resistive switching characteristics measured in pulse-voltage mode revealed that the resistance values in low resistance states vary with the amplitude and duration time of the pulsed-voltage stresses, indicating possibility of multilevel switching. On the basis of the experimental results, we discuss the potential of the Pt/BFO/SRO device for application in a large-capacity nonvolatile memory.
Anti-Parallel Circuit of Resistive Cu/TaOx/Pt Switches
Authors: Liu Tong , Kang Yuhong , Verma Mohini , Orlowski Marius
Published: May 2012

Resistive switches are being explored as a candidate for ultra-dense memory as well as logic circuits. The advantages of the resistive switches include high switching speed and excellent scaling potential. Here, we report for the first time the switching behavior of anti-parallel connected resistive switches (APS), which is a composite device exhibiting bi-directional switching properties. Under the opposite voltage biases, the two anti-parallel cells are alternatively set and reset, rendering the APS switched in both directions. For appropriate ON resistance values and set and reset voltages the two anti-parallel switches can be both set in conductive states. An APS device can be realized in a single switch by two coexisting Cu and oxygen vacancy nanofilaments which are formed and ruptured under opposite voltage polarities. The described APS behavior is of interest to logic applications and in neural networks.
Ab-Initio Modeling of the Resistance Switching Mechanism in RRAM Devices: Case Study of Hafnium Oxide (HfO2)
Authors: Duncan Dan , Magyari-Kope Blanka , Nishi Yoshio
Published: May 2012

The structures and energies of stoichiometric and oxygen-deficient monoclinic HfO2 were calculated using density functional theory. The electronic interactions in HfO2 were calculated using the LDA+U and GGA+U formalisms, where on-site Coulomb corrections were applied to the 5d electrons of hafnium (Ud) and the 2p electrons of oxygen (Up). Properties calculated using these techniques are compared to results obtained from LDA, GGA, hybrid functionals, and experiment. Ultimately, we show that LDA+Ud+Up and GGA+Ud+Up calculations of HfO2’s electronic and structural properties achieve a level of accuracy on par with much more computationally demanding hybrid functional techniques, such as PBE0 and HSE06.
Development of an Advisory System Based on Bayesian Network to Minimize Corrosion Problems in Underbalanced Drilling
Authors: Al-Yami Abdullah S. , Schubert Jerome
Published: May 2012

In underbalanced drilling the use of air as an injected gas sets up the potential for oxygen corrosion. Membrane nitrogen with about 5% oxygen eliminates the chance for fire or explosion, but does not solve the corrosion problem. Natural gas or cryogenic nitrogen eliminates the chance for oxygen corrosion, but does not always eliminate the chance of corrosion from other down hole acid gasses (Hydrogen Sulfide, H2S, Carbon Dioxide, and CO2). Any corrosion that occurs while drilling will be forced by some drilling fluid or drilling operational procedure such as KCl fluids, aerated mud, or floating mud cap operations.

The objective of this study is to identify some of the practical elements of corrosion encountered with underbalanced drilling and their optimum solution by development of an advisory system based on field cases and expert opinions. This advisory system is intended to be a field guide for the drilling engineer or rig supervisor. Corrosion is a matter of concern to the drilling contractor because of pitting or loss of steel in the drill pipe.

The advisory system is developed by proposing a set of guidelines for the optimal practices to minimize corrosion in underbalanced drilling operations. The optimum practices collected from data and experts' opinions, are integrated into a Bayesian Network BN to simulate likely scenarios of its use that will honor efficient practices when dictated by varying certain parameters. These parameters are measuring corrosion, identifying corrosion types, drill pipe and corrosion, treatment methods for H2S corrosion, CO2 sources and treatment, different methods to test for corrosion, general corrosion prevention and treatment, treatment methods for formation water and makeup water, and recommended practices to minimize corrosion in underbalanced drilling operations.

To the best of the authors' knowledge, this paper is the first study to develop an advisory system for minimizing corrosion problems. The developed software solutions on corrosion will be demonstrated such as using mechanical means to reduce O2 concentration and inhibitors for pipe coating. Finally, the advisory system list recommendations for all types of underbalanced drilling (flow, aerated, foam and mist) to minimize corrosion problems.
Corrosion Monitoring, Root Cause Analysis and Selection Criteria for Future Well Completion Design in Deep HPHT Sour Wells
Authors: Al-Saeed Abdulla , Chandra Ravi , Al-Mai Noura , Al-Awadi Mishari , Dashti Qasem
Published: May 2012

In high pressure high temperature (HPHT), deep sour gas condensate and volatile oil fields, in which the wells contains approximately 2 – 8 % H2S and 1 – 2.5% CO2 it is necessary to evaluate the corrosion rates for the downhole completion string. As it is well known that, corrosion leads to several major problems which affect the well integrity and the production sustainability through the production string failures and tubing casing pressure communication.

The purpose of this paper is to illustrate an initial monitoring plan to extend the life of a completion string, reduce the number of well interventions and workovers due to corrosion and scale deposition. This systematic approach will improve the future tubing selection criteria and evaluate the need for CRA material also enhancing the downhole inhibition system with reference to KOC safety regulations from operational and economical prospective.

The conclusions of the above will be based on data collected from 13 wells to investigate the key factors which accelerate the corrosion occurrence and rate. As such, a detailed analysis was constructed by using the baseline corrosion logs and their outputs such as time lapse, pitting, and fluid properties vs. metallurgy.
Corrosion and Scales Problems in a Mature Oil Field under Waterflooding; From the Dagnostic to the Integrity Management; Casabe Field, Colombia
Authors: Peralta-Vargas J. , Gonzalez V. , Bravo L. , Gandolfo J. Martin , Caicedo J. , Valera M.
Published: May 2012

Inorganic scales are new identified phenomena in Casabe field while corrosion has started to increase to alert the field operations. The field has been under waterflooding since 1985 with no much success due to lack of vertical selectivity. It was resumed in 2004 and boosted from 25000 BWIPD to 110000 BWIPD, and in consequence, some injection related problems which had never been recognized in the field turned out to be an issue from wellbores to surface facilities. Failures in tubings, casing and flowline integrity and storage facilities with evidences of corrosion, lighted on the alarms regarding the corrosion processes in the field.

Diagnostic process started in 2010, revising the fluids being injected and the produced fluids from the wells, knowing that injected water is fresh and formation water has salinities up to 50000 ppm. Water samples were collected and analyzed to establish a current field wide corrosion baseline and evaluating the impact of the water injection process from the water source, injection lines and down into the injection wells and the reservoir, likewise the back to the producing wells x-mas trees.

Chemical treatment is being applied upfront in the injection system, and corrective treatments have been implemented in some wells to reduce corrosion downhole. Simultaneously, a surface flowline integrity survey, maintenance and replacement by new materials were initiated to avoid spills or unexpected failures in the gathering system.

Nevertheless, the current scenario is regularly under control, continuing monitoring is required in throughout the field. A new integrity management plan for the asset is under preparation since produced water is planned to be re-injected in the reservoir as primary source for the waterflooding. Whilst re-injection starts up, potential problems for corrosion could come up including scaling as it is indicated by Langelier Saturation index in the produced water.
Structural Integrity Management: Painting Predictive Control
Authors: Witte Carlos C. , Ribeiro Duperron M.
Published: May 2012

Predictive maintenance (PdM) helps to determine the optimal time and date when repairs should be performed, offering cost savings over routine or preventive maintenance. PdM is frequently used for constant condition monitoring and equipment evaluation. The main goal is, by statistical process control, to determine when future maintenance will be more appropriate according to the structure condition. Our purpose is to introduce a new PdM concept and technique, avoiding corrective maintenance high costs by undertaking an effective painting control. It has been proven efficient on field, when tools are used such as integrity maintenance management software along with 3D modeling.

Structure integrity PdM techniques may be applied on critical structures such as offshore structures, port equipment, refineries, bridges or any structure located on aggressive weather conditions. A new painting control method can be found on integrity maintenance management software. This procedure is used to predict painting corrosion rates and optimize maintenance. It consists on simulating painting schemes using 3D models and doing assessments with image analysis tools on visual inspection, such as corroded area pictures taken on the timeline.

This predictive maintenance technique affects the traditional procedures; it may require some time investment to adapt to this new practice. The method implies in innumerous benefits since all the corrosion treatment is done before major interventions are needed. Therefore a corrosion coating monitoring means a low-cost maintenance, it extends the structure life integrity and lowers repairs frequency.
Epigenetic epidemiology in psychiatry: A translational neuroscience perspective
Authors: Pishva Ehsan , Kenis Gunter , Lesch Klaus , Prickaerts Jos , Steinbusch Harry , Hove Daniel , Os Jim , Rutten Bart
Published: May 2012

Accumulating evidence from the field of neuroscience indicates a crucial role for epigenetic regulation of gene expression in development and aging of nervous system and suggests that aberrations in the epigenetic machinery are involved in the etiology of psychiatric disorders. Epidemiologic evidence on epigenetics in psychiatry, however, is currently very sparsely available, but is consistent with a mediating role for epigenetic mechanisms in bringing together inherited and acquired risk factors into a neurodevelopmental etiological model of psychiatric disorders. Here, we review evidence from the epidemiological and neuroscience literature, and aim to converge the evidence into an etiological model of psychiatric disorders that encompasses environmental, genetic and epigenetic contributions. Given the dynamic nature of the epigenetic machinery and the potential reversibility of epigenetic modifications, future well-designed interdisciplinary and translational studies will be of key importance in order to identify new targets for prevention and therapeutic strategies.
Development of slide agglutination test for the rapid diagnosis of Mycoplasma infection in the chicken
Authors: Arefin M. , Begum J. A. , Parvin R. , Rahman M. M. , Khan M. A. H. N. A. , Chowdhury E. H.
Published: May 2012

Mycoplasma gallisepticum is considered to be the most important pathogenic Mycoplasma sp. and occurs world-wide. For effective control of mycoplasmosis, early diagnosis is the cornerstone, but the cultural method is laborious, expensive and timeconsuming, whereas agglutination test is easy to perform in field conditions and cheaper. Mycoplasma gallisepticum was isolated and two types of stained antigen produced. The antigen produced distinct tiny clumps with positive antisera of Mycoplasma spp. The slide agglutination system was sensitive, reliable and cheap. This method may be used to screen Mycoplasma infections in poultry farms.DOI: http://dx.doi.org/10.3329/bvet.v28i2.10688Bangl. vet. 2011. Vol. 28, No. 2, 80  84
Fear and Nostalgia in Times of Crisis: The Paradoxes of Globalization in Oliver Stone’s Money Never Sleeps (2010)
Authors: Oliete-Aldea Elena
Published: May 2012

The intense interconnectedness of 21st century globalization has provoked continuous re-definitions of the political, cultural, economic and social frontiers. The imminent consequence of these constant changes is an increasing feeling of instability and uncertainty in the postmodern individual, ultimately leading to vulnerability and fear. This anxiety has provoked a nostalgic search for the shelter of a community, symbolically represented by the ’home’: the place where human bonds could make up for the unpredictable border-crossing forces of globalization. The question that remains is whether this ’home’ is real or just a reflection of memories of imagined past securities.

After a brief analysis of the contemporary processes of globalization in the light of the 2008 economic crisis, my aim in this paper is to study how the crossborder movements, which had optimistically facilitated the liberalization of global economies, have now become a source of threat and fear for U.S. American individuals. More concretely, I propose to focus on Oliver Stone’s film Wall Street, Money Never Sleeps (2010), as I believe that both this cinematographic production reflects and questions the anxieties and social contradictions that the crossing of political, cultural and economic frontiers has provoked in the context of the contemporary financial crisis.
Outcome of Acute Peritoneal Dialysis in Northern Tanzania
Authors: Kilonzo Kajiru Gad , Ghosh Sudakshina , Temu Siya Anaeli , Maro Venance , Callegari John , Carter Mary , Handelman Garry , Finkelstein Fredric O. , Levin Nathan , Yeates Karen
Published: May 2012

Data on the burden of acute kidney injury (AKI) in resource-poor countries such as Tanzania are minimal because of a lack of nephrology services and an inability to recognize and diagnose AKI with any certainty. In the few published studies, high morbidity and mortality are reported. Improved nephrology care and dialysis may lower the mortality from AKI in these settings. Hemodialysis is expensive and technically challenging in resource-limited settings. The technical simplicity of peritoneal dialysis and the potential to reduce costs if consumables can be made locally, present an opportunity to establish cost-effective programs for managing AKI. Here, we document patient outcomes in a pilot peritoneal dialysis program established in 2009 at a referral hospital in Northern Tanzania.
Did Sîn-uballiṭ return his loans or not? Methods of archiving and pledging slave women by reason of a Neo-Babylonian archive
Authors: Cseke Henrietta
Published: May 2012

Résumé Jusque là on a étudié les textes des archives “ Sîn-uballiṭ ” surtout afin de pouvoir mieux reconstruire la chronologie des événements du début de l’empire néo-babylonien. Même si quelques chercheurs ont déjà essayé d’interpréter ces archives, il n’y a aucune analyse approfondie consacrée exclusivement à ces textes. Dans cette étude nous analysons de près un problème de détail concernant les emprunts contractés par Sîn-uballiṭ . Nous essayons de voir si il a remboursé ses emprunts ou non. En effet les différentes méthodes archivistiques de ces textes ne peuvent pas répondre à cette question, mais l’examen de la mise en gage des esclaves peut éclairer les points douteux. A partir de ses informations – complétées par celles que nous trouvons dans les lettres issues des archives – nous pouvons nous faire une idée plus précise des emprunts de Sîn-uballiṭ .
Financial Data Modeling using a Hybrid Bayesian Network Structured Learning Algorithm
Authors: Li Shun , Shi Da , Tan Shaohua
Published: May 2012

In this paper, a group of hybrid incremental learning algorithms for Bayesian network structures are proposed. The central idea of these hybrid algorithms is to use the polynomial-time constraint-based technique to build a candidate parent set for each domain variable, followed by the hill climbing search procedure to refine the current network structure under the guidance of the candidate parent sets. Experimental results show that, the authors’ hybrid incremental algorithms offer considerable computational complexity savings while obtaining better model accuracy compared to the existing incremental algorithms. One of their hybrid algorithms is also used to model financial data generated from American stock exchange markets. It finds out the predictors of the stock return among hundreds of financial variables and, at the same time, the authors’ algorithm also can recover the movement trend of the stock return.
An Early Robot Architecture for Cancer Healing
Authors: Abbas Mohamed Abdelhamid
Published: May 2012

Treating cancer tumors is a main goal of cancer research. The author of this paper identify a new manner to treat cancer tumors more effectively using a recommended architecture of a nanorobot called CANBOT. It contains a number of nano-components: an actuator, temperature sensor, chemical sensor, and microcontroller. CANBOT starts its role by moving toward the tumor cells using the actuator. It senses the tumor cell by capturing its image and sensing its chemicals by the chemical sensor. When CANBOT distinguishes the tumor, it verifies the survival of the tumor cells by its temperature sensor. CANBOT increases the temperature of the tumor cell through the warmer. Sensing of the cancer chemicals starts over to detect the remaining existence of cancer cells. The suggested nanorobot injects the cell with the drug from a tiny tank throughout a nano pump with a small pine needle. A nano-microcontroller controls the mechanism of CANBOT formative the role of each one and the appropriate sequences. The position of the proposed nanorobot is simulated with reference to the position of the tumor using an analytical model. The conclusion is drawn that destroying the tumor requires instilling the robot into the cancer tumor directly for effective treatment.