bluuebunny/crossref_metadata_2025 huggingface dataset:
Disulfide Rearrangement Triggered by Translocon Assembly Controls Lipopolysaccharide Export
Authors: Chng Shu-Sin , Xue Mingyu , Garner Ronald A. , Kadokura Hiroshi , Boyd Dana , Beckwith Jonathan , Kahne Daniel
Published: September 2012

Get Ready, Assemble, Fold

The outer membrane protein complex LptD/E is responsible for lipopolysaccharide export to the cell surface of
Escherichia coli.
LptD is an essential β-barrel protein that contains two disulfide bonds between nonconsecutive cysteines.

Chng
et al.

(p.
1665
, published online 30 August) describe the characterization of the oxidative folding and assembly pathway of LptD/E in living cells. A combination of steady-state and pulse-chase measurements was used to identify seven intermediates with different disulfide-bonded states, along the oxidative folding pathway. During folding and assembly, a non-native disulfide-bonded LptD intermediate accumulated and, triggered by β-barrel assembly and association with the lipoprotein LptE, rearranged to the native disulfide-bonded state required for lipopolysaccharide export. Thus, disulfide bond–dependent protein folding can involve the proper assembly of a two-protein complex in order to promote disulfide bond rearrangement.
Antimicrobial Susceptibility of Bacillus Strains Isolated from Primary Starters for African Traditional Bread Production and Characterization of the Bacitracin Operon and Bacitracin Biosynthesis
Authors: Adimpong David B. , Sørensen Kim I. , Thorsen Line , Stuer-Lauridsen Birgitte , Abdelgadir Warda S. , Nielsen Dennis S. , Derkx Patrick M. F. , Jespersen Lene
Published: September 2012

Bacillus
spp. are widely used as feed additives and probiotics. However, there is limited information on their resistance to various antibiotics, and there is a growing concern over the transfer of antibiotic resistance genes. The MIC for 8 antibiotics was determined for 85
Bacillus
species strains,
Bacillus subtilis
subsp.
subtilis
(
n
= 29),
Bacillus licheniformis
(
n
= 38), and
Bacillus sonorensis
(
n
= 18), all of which were isolated from starters for Sudanese bread production. All the strains were sensitive to tetracycline (8.0 mg/liter), vancomycin (4.0 mg/liter), and gentamicin (4.0 mg/liter) but resistant to streptomycin. Sensitivity to clindamycin, chloramphenicol, and kanamycin was species specific. The erythromycin resistance genes
ermD
and
ermK
were detected by PCR in all of the erythromycin-resistant (MIC, ≥16.0 mg/liter)
B. licheniformis
strains and one erythromycin-sensitive (MIC, 4.0 mg/liter)
B. licheniformis
strain. Several amino acid changes were present in the translated
ermD
and
ermK
nucleotide sequences of the erythromycin-sensitive strain, which could indicate ErmD and ErmK protein functionalities different from those of the resistance strains. The
ermD
and
ermK
genes were localized on an 11.4-kbp plasmid. All of the
B. sonorensis
strains harbored the bacitracin synthetase gene,
bacA
, and the transporter gene
bcrA
, which correlated with their observed resistance to bacitracin. Bacitracin was produced by all the investigated species strains (28%), as determined by ultra-high-definition quadrupole time-of-flight liquid chromatography-mass spectrometry (UHD-QTOF LC/MS). The present study has revealed species-specific variations in the antimicrobial susceptibilities of
Bacillus
spp. and provides new information on MIC values, as well as the occurrence of resistance genes in
Bacillus
spp., including the newly described species
B. sonorensis
.
Evaluation of Sample Recovery Efficiency for Bacteriophage P22 on Fomites
Authors: Herzog Amanda B. , Pandey Alok K. , Reyes-Gastelum David , Gerba Charles P. , Rose Joan B. , Hashsham Syed A.
Published: September 2012

Fomites are known to play a role in the transmission of pathogens. Quantitative analysis of the parameters that affect sample recovery efficiency (SRE) at the limit of detection of viruses on fomites will aid in improving quantitative microbial risk assessment (QMRA) and infection control. The variability in SRE as a function of fomite type, fomite surface area, sampling time, application media, relative humidity (rH), and wetting agent was evaluated. To quantify the SRE, bacteriophage P22 was applied onto fomites at average surface densities of 0.4 ± 0.2 and 4 ± 2 PFU/cm
2
. Surface areas of 100 and 1,000 cm
2
of nonporous fomites found in indoor environments (acrylic, galvanized steel, and laminate) were evaluated with premoistened antistatic wipes. The parameters with the most effects on the SRE were sampling time, fomite surface area, wetting agent, and rH. At time zero (the initial application of bacteriophage P22), the SRE for the 1,000-cm
2
fomite surface area was, on average, 40% lower than that for the 100-cm
2
fomite surface area. For both fomite surface areas, the application medium Trypticase soy broth (TSB) and/or the laminate fomite predominantly resulted in a higher SRE. After the applied samples dried on the fomites (20 min), the average SRE was less than 3%. A TSB wetting agent applied on the fomite improved the SRE for all samples at 20 min. In addition, an rH greater than 28% generally resulted in a higher SRE than an rH less than 28%. The parameters impacting SRE at the limit of detection have the potential to enhance sampling strategies and data collection for QMRA models.
Carbohydrate Hydrolysis and Transport in the Extreme Thermoacidophile Sulfolobus solfataricus
Authors: Lalithambika Sreedevi , Peterson Landon , Dana Karl , Blum Paul
Published: September 2012

Extremely thermoacidophilic microbes, such asSulfolobus solfataricus, are strict chemoheterotrophs despite their geologic niche. To clarify their ecophysiology, the overlapping roles of endoglucanases and carbohydrate transporters were examined during growth on soluble cellodextrins as the sole carbon and energy source. Strain-specific differences in genome structure implied a unique role for one of three endogenous endoglucanases. Plasmid-based endoglucanase expression promoted the consumption of oligosaccharides, including cellohexaose (G6) through cellonanaose (G9). Protein transporters required for cellodextrin uptake were identified through mutagenesis and complementation of an ABC transporter cassette, including a putative oligosaccharide binding protein. In addition, ablation of the binding protein compromised growth on glucose and alpha-linked oligosaccharides while inactivation of a previously described glucose transporter had no apparent impact. These data demonstrate thatS. solfataricusemploys a redundant mechanism for soluble cellodextrin catabolism having both substrate uptake and extracytoplasmic hydrolytic components.
Characterization of an Endo-Processive-Type Xyloglucanase Having a β-1,4-Glucan-Binding Module and an Endo-Type Xyloglucanase from Streptomyces avermitilis
Authors: Ichinose Hitomi , Araki Yuko , Michikawa Mari , Harazono Koichi , Yaoi Katsuro , Karita Shuichi , Kaneko Satoshi
Published: September 2012

We cloned two glycoside hydrolase family 74 genes, the
sav_1856
gene and the
sav_2574
gene, from
Streptomyces avermitilis
NBRC14893 and characterized the resultant recombinant proteins. The
sav_1856
gene product (SaGH74A) consisted of a catalytic domain and a family 2 carbohydrate-binding module at the C terminus, while the
sav_2574
gene product (SaGH74B) consisted of only a catalytic domain. SaGH74A and SaGH74B were expressed successfully and had molecular masses of 92 and 78 kDa, respectively. Both recombinant proteins were xyloglucanases. SaGH74A had optimal activity at 60°C and pH 5.5, while SaGH74B had optimal activity at 55°C and pH 6.0. SaGH74A was stable over a broad pH range (pH 4.5 to 9.0), whereas SaGH74B was stable over a relatively narrow pH range (pH 6.0 to 6.5). Analysis of the hydrolysis products of tamarind xyloglucan and xyloglucan-derived oligosaccharides indicated that SaGH74A was endo-processive, while SaGH74B was a typical endo-enzyme. The C terminus of SaGH74A, which was annotated as a carbohydrate-binding module, bound to β-1,4-linked glucan-containing soluble polysaccharides such as hydroxyethyl cellulose, barley glucan, and xyloglucan.
Microbial Community Dynamics of an Urban Drinking Water Distribution System Subjected to Phases of Chloramination and Chlorination Treatments
Authors: Hwang Chiachi , Ling Fangqiong , Andersen Gary L. , LeChevallier Mark W. , Liu Wen-Tso
Published: September 2012

Water utilities in parts of the U.S. control microbial regrowth in drinking water distribution systems (DWDS) by alternating postdisinfection methods between chlorination and chloramination. To examine how this strategy influences drinking water microbial communities, an urban DWDS (population ≅ 40,000) with groundwater as the source water was studied for approximately 2 years. Water samples were collected at five locations in the network at different seasons and analyzed for their chemical and physical characteristics and for their microbial community composition and structure by examining the 16S rRNA gene via terminal restriction fragment length polymorphism and DNA pyrosequencing technology. Nonmetric multidimension scaling and canonical correspondence analysis of microbial community profiles could explain >57% of the variation. Clustering of samples based on disinfection types (free chlorine versus combined chlorine) and sampling time was observed to correlate to the shifts in microbial communities. Sampling location and water age (<21.2 h) had no apparent effects on the microbial compositions of samples from most time points. Microbial community analysis revealed that among major core populations,
Cyanobacteria
,
Methylobacteriaceae
,
Sphingomonadaceae
, and
Xanthomonadaceae
were more abundant in chlorinated water, and
Methylophilaceae
,
Methylococcaceae
, and
Pseudomonadaceae
were more abundant in chloraminated water. No correlation was observed with minor populations that were detected frequently (<0.1% of total pyrosequences), which were likely present in source water and survived through the treatment process. Transient microbial populations including
Flavobacteriaceae
and
Clostridiaceae
were also observed. Overall, reversible shifts in microbial communities were especially pronounced with chloramination, suggesting stronger selection of microbial populations from chloramines than chlorine.
Autotrophic Production of Stable-Isotope-Labeled Arginine in Ralstonia eutropha Strain H16
Authors: Lütte Steffen , Pohlmann Anne , Zaychikov Evgeny , Schwartz Edward , Becher Johannes R. , Heumann Hermann , Friedrich Bärbel
Published: September 2012

With the aim of improving industrial-scale production of stable-isotope (SI)-labeled arginine, we have developed a system for the heterologous production of the arginine-containing polymer cyanophycin in recombinant strains of
Ralstonia eutropha
under lithoautotrophic growth conditions. We constructed an expression plasmid based on the cyanophycin synthetase gene (
cphA
) of
Synechocystis
sp. strain PCC6308 under the control of the strong P

cbbL

promoter of the
R. eutropha
H16

cbb
c

operon (coding for autotrophic CO
2
fixation). In batch cultures growing on H
2
and CO
2
as sole sources of energy and carbon, respectively, the cyanophycin content of cells reached 5.5% of cell dry weight (CDW). However, in the absence of selection (i.e., in antibiotic-free medium), plasmid loss led to a substantial reduction in yield. We therefore designed a novel addiction system suitable for use under lithoautotrophic conditions. Based on the hydrogenase transcription factor HoxA, this system mediated stabilized expression of
cphA
during lithoautotrophic cultivation without the need for antibiotics. The maximum yield of cyanophycin was 7.1% of CDW. To test the labeling efficiency of our expression system under actual production conditions, cells were grown in 10-liter-scale fermentations fed with
13
CO
2
and
15
NH
4
Cl, and the
13
C/
15
N-labeled cyanophycin was subsequently extracted by treatment with 0.1 M HCl; 2.5 to 5 g of [
13
C/
15
N]arginine was obtained per fed-batch fermentation, corresponding to isotope enrichments of 98.8% to 99.4%.
Residual Viral and Bacterial Contamination of Surfaces after Cleaning and Disinfection
Authors: Tuladhar Era , Hazeleger Wilma C. , Koopmans Marion , Zwietering Marcel H. , Beumer Rijkelt R. , Duizer Erwin
Published: September 2012

Environmental surfaces contaminated with pathogens can be sources of indirect transmission, and cleaning and disinfection are common interventions focused on reducing contamination levels. We determined the efficacy of cleaning and disinfection procedures for reducing contamination by noroviruses, rotavirus, poliovirus, parechovirus, adenovirus, influenza virus,
Staphylococcus aureus
, and
Salmonella enterica
from artificially contaminated stainless steel surfaces. After a single wipe with water, liquid soap, or 250-ppm free chlorine solution, the numbers of infective viruses and bacteria were reduced by 1 log
10
for poliovirus and close to 4 log
10
for influenza virus. There was no significant difference in residual contamination levels after wiping with water, liquid soap, or 250-ppm chlorine solution. When a single wipe with liquid soap was followed by a second wipe using 250- or 1,000-ppm chlorine, an extra 1- to 3-log
10
reduction was achieved, and except for rotavirus and norovirus genogroup I, no significant additional effect of 1,000 ppm compared to 250 ppm was found. A reduced correlation between reduction in PCR units (PCRU) and reduction in infectious particles suggests that at least part of the reduction achieved in the second step is due to inactivation instead of removal alone. We used data on infectious doses and transfer efficiencies to estimate a target level to which the residual contamination should be reduced and found that a single wipe with liquid soap followed by a wipe with 250-ppm free chlorine solution was sufficient to reduce the residual contamination to below the target level for most of the pathogens tested.
“Remake” by High-Throughput Sequencing of the Microbiota Involved in the Production of Water Buffalo Mozzarella Cheese
Authors: Ercolini Danilo , De Filippis Francesca , La Storia Antonietta , Iacono Michele
Published: September 2012

Intermediates of production of two batches of traditional mozzarella cheese were analyzed by culture-independent pyrosequencing. The quantitative distribution of taxa within the samples suggested that thermophilic lactic acid bacteria from the natural starter were mainly responsible for the fermentation, while microorganisms found in raw milk did not develop during fermentation.
Epigallocatechin Gallate Induces Upregulation of the Two-Component VraSR System by Evoking a Cell Wall Stress Response in Staphylococcus aureus
Authors: Levinger Oren , Bikels-Goshen Tamar , Landau Elad , Fichman Merav , Shapira Roni
Published: September 2012

We previously found that a short exposure of
Staphylococcus aureus
to subinhibitory (SI) doses of epigallocatechin gallate (EGCG) results in increased cell wall thickness, adaptation, and enhanced tolerance to cell-wall-targeted antibiotics. In this study, the response to EGCG of
sigB
and
vraSR
transcription factor mutants was characterized. We show that in contrast to the results observed for wild-type (WT) strains, an
S. aureus
315
vraSR
null mutant exposed to SI doses of EGCG did not exhibit increased tolerance to EGCG and oxacillin. A diminished increase in tolerance to ampicillin (from 16-fold to 4-fold) and no change in the magnitude of resistance to vancomycin were observed. Preexposure to EGCG enhanced the tolerance of wild-type and
sigB
null mutant cells to lysostaphin, but this enhancement was much weaker in the
vraSR
null mutant. Marked upregulation (about 60-fold) of
vraR
and upregulation of the peptidoglycan biosynthesis-associated genes
murA
,
murF
, and
pbp2
(2-, 5-, and 6-fold, respectively) in response to SI doses of EGCG were determined by quantitative reverse transcription-PCR (qRT-PCR). EGCG also induced the promoter of
sas016
(encoding a cell wall stress protein of unknown function which is not induced in
vraSR
null mutants) in a concentration-dependent manner, showing kinetics comparable to those of cell-wall-targeting antibiotics. Taken together, our results suggest that the two-component VraSR system is involved in modulating the cell response to SI doses of EGCG.
Phe317 Is Essential for Rubber Oxygenase RoxA Activity
Authors: Birke Jakob , Hambsch Nadja , Schmitt Georg , Altenbuchner Josef , Jendrossek Dieter
Published: September 2012

RoxA is an extracellular
c
-type diheme cytochrome secreted by
Xanthomonas sp.
strain 35Y during growth on rubber. RoxA cleaves poly(
cis
-1,4-isoprene) to 12-oxo-4,8-dimethyltrideca-4,8-diene-1-al (ODTD). Analysis of the RoxA structure revealed that Phe317 is located in close proximity (≈5 Å) to the N-terminal heme that presumably represents the active site. To find evidence of whether Phe317 is important for catalysis, we changed it to tyrosine, tryptophan, leucine, histidine, or alanine. All five RoxA muteins were expressed after integration of the respective gene into the chromosome of a
Xanthomonas sp.
ΔroxA
strain. Residual clearing zone formation on opaque latex agar was found for
Xanthomonas sp.
strains expressing the Phe317Leu, Phe317Ala, or Phe317His variant (wild type > Leu > Ala > His). Strains in which Phe317 was changed to tyrosine or tryptophan were inactive. Phe317Ala and Phe312Leu RoxA muteins were purified, and polyisoprene cleavage activities were reduced to ≈3% and 10%, respectively. UV-visible spectroscopy of RoxA muteins confirmed that both heme groups were present in an oxidized form, but spectral responses to the addition of low-molecular-weight (inhibitory) ligand molecules such as imidazole and pyridine were different from those of wild-type RoxA. Our results show that residue 317 is involved in interaction with substrates. This is the first report on structure-function analysis of a polyisoprene-cleaving enzyme and on the identification of an amino acid that is essential for polyisoprene cleavage activity.
Colony Organization in the Green Alga Botryococcus braunii (Race B) Is Specified by a Complex Extracellular Matrix
Authors: Weiss Taylor L. , Roth Robyn , Goodson Carrie , Vitha Stanislav , Black Ian , Azadi Parastoo , Rusch Jannette , Holzenburg Andreas , Devarenne Timothy P. , Goodenough Ursula
Published: September 2012

Botryococcus braunii
is a colonial green alga whose cells associate via a complex extracellular matrix (ECM) and produce prodigious amounts of liquid hydrocarbons that can be readily converted into conventional combustion engine fuels. We used quick-freeze deep-etch electron microscopy and biochemical/histochemical analysis to elucidate many new features of
B. braunii
cell/colony organization and composition. Intracellular lipid bodies associate with the chloroplast and endoplasmic reticulum (ER) but show no evidence of being secreted. The ER displays striking fenestrations and forms a continuous subcortical system in direct contact with the cell membrane. The ECM has three distinct components. (i) Each cell is surrounded by a fibrous β-1, 4- and/or β-1, 3-glucan-containing cell wall. (ii) The intracolonial ECM space is filled with a cross-linked hydrocarbon network permeated with liquid hydrocarbons. (iii) Colonies are enclosed in a retaining wall festooned with a fibrillar sheath dominated by arabinose-galactose polysaccharides, which sequesters ECM liquid hydrocarbons. Each cell apex associates with the retaining wall and contributes to its synthesis. Retaining-wall domains also form “drapes” between cells, with some folding in on themselves and penetrating the hydrocarbon interior of a mother colony, partitioning it into daughter colonies. We propose that retaining-wall components are synthesized in the apical Golgi apparatus, delivered to apical ER fenestrations, and assembled on the surfaces of apical cell walls, where a proteinaceous granular layer apparently participates in fibril morphogenesis. We further propose that hydrocarbons are produced by the nonapical ER, directly delivered to the contiguous cell membrane, and pass across the nonapical cell wall into the hydrocarbon-based ECM.
Structure and Interactions of the Cytoplasmic Domain of the Yersinia Type III Secretion Protein YscD
Authors: Gamez Alicia , Mukerjea Romila , Alayyoubi Maher , Ghassemian Majid , Ghosh Partho
Published: September 2012

The virulence of a large number of Gram-negative bacterial pathogens depends on the type III secretion (T3S) system, which transports select bacterial proteins into host cells. An essential component of theYersiniaT3S system is YscD, a single-pass inner membrane protein. We report here the 2.52-Å resolution structure of the cytoplasmic domain of YscD, called YscDc. The structure confirms that YscDc consists of a forkhead-associated (FHA) fold, which in many but not all cases specifies binding to phosphothreonine. YscDc, however, lacks the structural properties associated with phosphothreonine binding and thus most likely interacts with partners in a phosphorylation-independent manner. Structural comparison highlighted two loop regions, L3 and L4, as potential sites of interactions. Alanine substitutions at L3 and L4 had no deleterious effects on protein structure or stability but abrogated T3S in a dominant negative manner. To gain insight into the function of L3 and L4, we identified proteins associated with YscD by affinity purification coupled to mass spectrometry. The lipoprotein YscJ was found associated with wild-type YscD, as was the effector YopH. Notably, the L3 and L4 substitution mutants interacted with more YopH than did wild-type YscD. These substitution mutants also interacted with SycH (the specific chaperone for YopH), the putative C-ring component YscQ, and the ruler component YscP, whereas wild-type YscD did not. These results suggest that substitutions in the L3 and L4 loops of YscD disrupted the dissociation of SycH from YopH, leading to the accumulation of a large protein complex that stalled the T3S apparatus.
Rapid Depletion of Target Proteins Allows Identification of Coincident Physiological Responses
Authors: Carr Ana C. , Taylor Katherine L. , Osborne Melinda S. , Belous Bradley T. , Myerson Joseph P. , Moore Sean D.
Published: September 2012

Targeted protein degradation is a powerful tool that can be used to create unique physiologies depleted of important factors. Current strategies involve modifying a gene of interest such that a degradation peptide is added to an expressed target protein and then conditionally activating proteolysis, either by expressing adapters, unmasking cryptic recognition determinants, or regulating protease affinities using small molecules. For each target, substantial optimization may be required to achieve a practical depletion, in that the target remains present at a normal level prior to induction and is then rapidly depleted to levels low enough to manifest a physiological response. Here, we describe a simplified targeted degradation system that rapidly depletes targets and that can be applied to a wide variety of proteins without optimizing target protease affinities. The depletion of the target is rapid enough that a primary physiological response manifests that is related to the function of the target. Using ribosomal protein S1 as an example, we show that the rapid depletion of this essential translation factor invokes concomitant changes to the levels of several mRNAs, even before appreciable cell division has occurred.
Quantitative cranial ultrasound prediction of severity of disability in premature infants with post-haemorrhagic ventricular dilatation
Authors: Jary Sally , Kmita Grazyna , Wroblewska Jolanta , Whitelaw Andrew
Published: September 2012

Background

Infants with post-haemorrhagic ventricular dilatation (PHVD) have a high risk of severe disability and parenchymal infarction increases this risk. Existing cranial ultrasound (CUS) markers of neurodevelopmental outcome are based on categorical features.

Objective

To investigate to what extent quantitative CUS measurements correlated with severity of developmental outcome and the need for ventriculoperitoneal (VP) shunt at 2 years of age.

Design

69 premature infants with PHVD had lateral ventricle area, intraventricular echodensity and parenchymal lesion dimensions measured at the start of treatment for PHVD. Outcome measures were the Bayley Scales of Infant Development-II and functional ability at 2 years of age. Bayley developmental quotients (DQ) were used in preference to index scores to enable inclusion of severely disabled children.

Results

Quantitative CUS measurements of parenchymal lesion area correlated significantly with later mental and motor DQ. Intraventricular echodensity area correlated with motor DQ in infants with grade 4 intraventricular haemorrhage (IVH). Neither ventricular area nor ventricular width correlated with DQ in grade 3 IVH. Infants who ultimately required a VP shunt had a significantly larger intraventricular echodensity area.

Conclusions

CUS measurement of parenchymal lesions in infants with PHVD can increase the precision of predicting severe mental and motor disability, but ventricular size at the start of treatment is not predictive of outcome in infants with PHVD following grade 3 IVH.
Eight clinical conundrums relating to anterior cruciate ligament (ACL) injury in sport: recent evidence and a personal reflection
Authors: Renström Per A
Published: September 2012

Over two million anterior cruciate ligament (ACL) injuries occur worldwide annually, and the greater prevalence for ACL injury in young female athletes is one of the major problems in sports medicine. Optimal treatment of ACL injury requires individualised management. Patient selection is of utmost importance, and so is respect for the patient's functional demands and interests. All patients with an ACL tear may not need surgery, however athletes and persons with an active lifestyle with high knee functional demands including cutting motions need and should be offered surgery. In many cases it may not be the choice of graft or technique that is the key for success, but the choice of surgeon. The surgeon should be experienced and use a reconstructive procedure he/she knows very well and is comfortable with. The development of osteoarthritis after an ACL injury depends very much on the injury mechanism and concurrent meniscal injury, as knee articular cartilage continues to heal for 1–2 years after an ACL injury. Therefore the surgeon and rehabilitation team must pay attention to the rehabilitation process and to the decision when to return to sport. Return to sport must be carefully considered, as top-level sport in itself is one main risk factor for osteoarthritis after ACL injury. The present criteria for return to sport need to be revisited, also due to the fact that recurrent injury seems to be an increasing problem. ACL injury prevention programmes are now available in some sports. The key issue for a prevention programme to be successful is proper implementation. Vital factors for success include the individual coaching of the player and well controlled compliance with the training programme. Preventive activities should be more actively supported by the involved athletic community. Despite substantial advances in the field of ACL injury over the past 40 years, substantial management challenges remain.
An evaluation of a public health advocacy strategy to enhance palliative care provision in Zambia
Authors: Logie Dorothy Elizabeth
Published: September 2012

Background

The provision of palliative and end-of-life care for patients with progressive disease is inadequate worldwide. The WHO strategy to develop a public health system of palliative care at the national level proposes a quadripartite approach: policy, education, drug availability and implementation. This is particularly necessary in low income countries facing a high disease burden with low resources. To date there have been no published evaluations of advocacy strategies aiming to use the WHO approach to enhance access to palliative care.

Objective

To evaluate the Palliative Care Initiative which implements the WHO approach to strategically improve palliative care throughout Zambia, using a multiple methods rapid field evaluation.

Methods and results

Eight hospices and palliative care organisations in Zambia were part-funded over 2 years (2009–11) and were thus able to expand their services, offer a reliable supply of drugs, secure fuel for transport, and support home carers. Simultaneously, an extensive programme of rural and urban training resulted in staff being more confident in caring for the dying with improved attitudes to the concerns of very ill patients and their families. A multi-agency morphine pilot project led by the Palliative Care Association of Zambia and the Ministry of Health resolved some of the obstacles and increased morphine availability although its use remains low. Palliative care is now being considered by the technical working group at the Ministry of Health.

Conclusions

For palliative care to thrive in any resource-poor country it must be integrated into the public health system and secure long-term funding.
A pregnant patient with a positive hepatitis B surface antigen
Authors: Mufti Arjmand Rasool , Reau Nancy
Published: September 2012

Hepatitis B is a major cause of liver disease worldwide. The highest rates of chronic infection occur in subjects who are infected early in life and these patients are also at the greatest risk of developing complications such as hepatocellular carcinoma and cirrhosis from the disease. There has been a concerted worldwide effort to immunise newborns that are at the highest risk of acquiring infection. In 1992, when WHO recommended global vaccination against hepatitis B, only 31 countries elected to participate in the programme. By 2009, 177 countries were part of WHO national infant immunisation programme. Consequently, maternal screening and infant immunoprophylaxis have significantly reduced vertical transmission of hepatitis B. In this paper, we will review the management of hepatitis B in the pregnant population and identify some of the challenges that are encountered in this specialised population.
British Veterinary AssociationAnnual General Meeting Liverpool, September 29, 2012
Authors: Alderman H.
Published: September 2012

The 2012 Annual General Meeting of the British Veterinary Association will be held at the Merseyside Maritime Museum, Liverpool, on Saturday, September 29, 2012, at 16.00.
ANALYSIS OF A LATENCY HIDING BROADCASTING ALGORITHM ON A RECONFIGURABLE OPTICAL INTERCONNECT
Authors: AFSAHI AHMAD , DIMOPOULOS NIKITAS J.
Published: September 2012

Free-space optical interconnection is used to fashion a reconfigurable network. Since network reconfiguration is expensive compared to message transmission in such networks, latency hiding techniques can be used to increase the performance of collective communications operations. Berthome and Ferreira have recently proposed a broadcasting algorithm for their loosely-coupled optically reconfigurable parallel computer where they have shown that the total number of nodes, N(S), informed up to step S follows a recurrence relation. We have adapted their algorithm to our reconfigurable optical network, RON (K, N), which has slightly different modeling. We present a new analysis of this broadcasting algorithm on our network. This paper contributes by providing closed formulations for the N(S) that yield the termination time for both single-port and k-port modeling. The derived closed formulate are easier to computer than the recurrence relations.
TRADING REPLICATION FOR COMMUNICATION IN PARALLEL DISTRIBUTED-MEMORY DENSE SOLVERS
Authors: IRONY DROR , TOLEDO SIVAN
Published: September 2012

We present new communication-efficient parallel dense linear solvers: a solver for triangular linear systems with multiple right-hand sides and an LU factorization algorithm. These solvers are highly parallel and they perform a factor of 0.4P1/6 less communication than existing algorithms, where P is number of processors. The new solvers reduce communication at the expense of using more temporary storage. Previously, algorithms that reduce communication by using more memory were only known for matrix multiplication. Our algorithms are recursive, elegant, and relatively simple to implement. We have implemented them using MPI, a message-passing libray, and tested them on a cluster of workstations.
THE JACOBSON GRAPH OF COMMUTATIVE RINGS
Authors: AZIMI A. , ERFANIAN A. , FARROKHI D. G. M.
Published: September 2012

Let R be a commutative ring with nonzero identity. Then the Jacobson graph of R, denoted by 𝔍R, is defined as a graph with vertex set R\J(R) such that two distinct vertices x and y are adjacent if and only if 1 - xy is not a unit of R. We obtain some graph theoretical properties of 𝔍R including its connectivity, planarity and perfectness and we compute some of its numerical invariants, namely diameter, girth, dominating number, independence number and vertex chromatic number and give an estimate for its edge chromatic number.
FACTORIZATION OF SOME COMPOSITE POLYNOMIALS OVER FINITE FIELDS
Authors: ALIZADEH MAHMOOD , KYUREGYAN MELSIK K.
Published: September 2012

In this paper we study the factorization of composite polynomials, constructed with some polynomial composition methods, into irreducible factors over finite fields. The main aim of this paper is to provide a proof of a useful theorem of Varshamov (1973), which had been stated by him, without proof.
ON GRÖBNER BASES FOR FLAG MANIFOLDS F(1, 1, … , 1, n)
Authors: PETROVIĆ ZORAN Z. , PRVULOVIĆ BRANISLAV I.
Published: September 2012

The knowledge of cohomology of a manifold has shown to be quite relevant in various investigations: the question of vector fields, immersion and embedding dimension, and recently even in topological robotics. The method of Gröbner bases is applicable when the cohomology of the manifold is a quotient of a polynomial algebra. The mod 2 cohomology of the real flag manifold F(n1, n2, …, nr) is known to be isomorphic to a polynomial algebra modulo a certain ideal. Reduced Gröbner bases for these ideals are obtained in the case of manifolds F(1, 1, …, 1, n) including the complete flag manifolds (n = 1).
CAYLEY GRAPHS OF PARTIALLY ORDERED SETS
Authors: AFKHAMI MOJGAN , BARATI ZAHRA , KHASHYARMANESH KAZEM
Published: September 2012

In this paper, we introduce the Cayley graph of a partially ordered set (poset). Let (P, ≤) be a poset, and let S be a subset of P. We define the undirected Cayley graph of P, denoted by Cay (P, S), as a graph with vertex-set P and edge-set E consisting of those sets {x, y} such that y ∈ {x, s}ℓ or x ∈ {y, s}ℓ for some s ∈ S, where for a subset T of P, Tℓ is the set of all x ∈ P such that x ≤ t, for all t ∈ T. We study some basic properties of Cay (P, S) such as connectivity, diameter and girth.
DISTRIBUTION OF PRODUCER SIZE IN GLOBALIZED MARKET
Authors: FAN H.
Published: September 2012

Distribution of producer size in a globalized market is a complex market phenomena, which is affected by the market behavior of consumers such as the loyalty of consumers to producers and the purchasing power of consumers, as well as the trade barriers among countries. In the present paper, in order to study the distribution of producer size in the globalized market, we construct a bipartite network that consists of consumers and producers with community structure. We find that the distribution of producer size in each community in a multi-community network can be projected to that in one-community bipartite network by mapping the globalized market behavior of consumers to an isolated market behavior. The mapped market behavior is dependent on the trade barriers among communities. The distribution of producer size in globalized market is thereby dependent on the mapped loyalty of consumers and the mapped growing rate of purchasing power. Furthermore, simulation results show that the distribution of producer size differs community by community. It follows the power-law distribution if both the mapped loyalty of consumers and growing rate are high.
THE QSAR RESEARCH ON AURONE INHIBITORS OF HEPATITIS C VIRUS RNA-DEPENDENT RNA POLYMERASE BY APPLYING MULTI-DIMENSIONAL SCALING METHOD
Authors: HU YONG-HONG , ZHANG BAO-HUA
Published: September 2012

In this paper, we take naturally occurring 2-benzylidenebenzofuran-3-ones (aurones) inhibitors of hepatitis C virus (HCV) RNA-dependent RNA polymerase (RdRp) as an example to study the Multi-dimensional scaling (MDS) method for structure-activity relationship. By analyzing training set molecules, our MDS method combined with a PROXSCAL algorithm can predict inhibitory activity of most compounds correctly. Thus, a new sample's activity can be estimated and judged conveniently, and whether it should be synthesized can be known. The MDS method is applicable to optimize the structure for a compound and to provide suggestions for drug design.
China-ASEAN Connectivity: China's Objectives, Strategies, Projects and Challenges
Authors: LI Chenyang , LYE Liang Fook
Published: September 2012

The Master Plan on ASEAN Connectivity has spurred China and ASEAN (Association of Southeast Asian Nations) to explore more substantive cooperation. Yunann and Guangxi are riding on the connectivity bandwagon to secure Beijing's support to spur their socio-economic development. However, the pursuit of further connectivity between China and ASEAN has its challenges including the need for coordination between the competing provinces and translating various proposals into actual progress on the ground.
China-Myanmar Economic Corridor and its Implications
Authors: ZHAO Hong , YANG Mu
Published: September 2012

With China's increasing investment in Myanmar, a prosperous economic corridor is expected to be formed along China-Myanmar oil and gas pipelines. This economic corridor project is part of Beijing's broader strategy of diversifying its sources of imported energy, as well increasing its economic integration with Myanmar. Although China has long-term strategic energy investment plans in this country, it does not necessarily mean that China has free rein over the outcomes.
The China-Philippine Standoff in the South China Sea
Authors: TSENG Katherine Hui-Yi
Published: September 2012

The dispute between the Philippines and China concerning Chinese fishing boats in the Philippines Exclusive Economic Zone ended in a standoff. The Philippines has sought support from the United States, which appears to be distancing itself from regional tensions to avoid jeopardising the trust between Washington and Beijing. China's attitude towards maritime issues has changed, allowing room for discussion. The author opines that China's outdated and flawed governmental structures need to be rectified.
The Fall of Bo Xilai and the Seduction of the Chongqing Model
Authors: GORE Lance L. P.
Published: September 2012

The spectacular fall of Bo Xilai is widely interpreted as the demise of the Chongqing model. This conclusion is however premature: it fails to see that the model is rooted in the current political system, derived from the CCP's traditions and identity, and has tremendous appeal among the poor masses given the prevalence of inequality and social injustice. Fundamental political reforms are necessary to prevent the resurgence of Maoism.
From Locodollar to Asianyuan: Hong Kong Dollar at a Crossroads
Authors: ZHENG Victor , LUK Roger
Published: September 2012

After re-pegging the Renminbi (RMB) from the US Dollar (USD) to a currency basket, the Hong Kong Dollar (HKD) is caught between the diverging Chinese and US economies. Disparity between the RMB and USD exchange rates and the HKD, and the disharmony of Chinese and US monetary policies towards Hong Kong have become increasingly acute. Hong Kong is at a crossroads. Should the HKD migrate from the dollar-zone to the renminbi-zone and realign with the national currency, and how? This paper analyses the mismatch and tries to answer the question.
Food Security as a New Challenge in Asia
Authors: WONG John
Published: September 2012

All nations, big or small, are concerned with the issue of food security. Even for Singapore, which is almost 100% dependent on external food supply, it still has to face the challenges of maintaining a stable food supply. Food crisis can potentially emerge as a new challenge for regional security not just in Asia but also for the whole international community as well.
ELECTROSPINNING OF BIOMATERIALS AND THEIR APPLICATIONS IN TISSUE ENGINEERING
Authors: WU JEN-CHIEH , LORENZ H. PETER
Published: September 2012

Electrospinning is a process for generating micrometer or nanometer scale polymer fibers with large surface areas and high porosity. For tissue engineering research, the electrospinning technique provides a quick way to fabricate fibrous scaffolds with dimensions comparable to the extracellular matrix (ECM). A variety of materials can be used in the electrospinning process, including natural biomaterials as well as synthetic polymers. The natural biomaterials have advantages such as excellent biocompatibility and biodegradability, which can be more suitable for making biomimic scaffolds. In the last two decades, there have been growing numbers of studies of biomaterial fibrous scaffolds using the electrospinning process. In this review, we will discuss biomaterials in the electrospinning process and their applications in tissue engineering.
ADDITION OF CONDUCTIVE ELEMENTS TO POLYMERIC SCAFFOLDS FOR MUSCLE TISSUE ENGINEERING
Authors: MCKEON-FISCHER K. D. , FREEMAN J. W.
Published: September 2012

Cardiac and skeletal muscles are two tissues that would benefit from an electrically conductive scaffold to regenerate lost or lower functioning areas. By augmenting polymeric scaffolds with conductive elements, the contractile process for both muscles could increase. In this review, the components reviewed include polyaniline (PANi), gold (Au) nanoparticles, and carbon nanotubes (CNT). PANi has been combined with several polymers and increased the conductivity of the scaffolds. It is biocompatible, but increases mechanical properties and decreases scaffold elongation. Tissue engineering using nanoparticles is an emerging area and considerable research focuses on determining possible toxicity due to nanoparticle concentration. Contradicting data exists for both Au nanoparticles and CNT. Smaller Au nanoparticles damage cardiac tissue in vivo while larger ones do not. By comparison, in vitro data shows no harmful results for skeletal muscle cells. Data for CNT is just as diverse as the amount, orientation and further purification or functionalization could all play a role in determining biocompatibility. Future research should focus on establishing the conductivity level needed for each muscle tissue to ascertain the amount of conductive element needed so the most suitable one can be utilized.
LIGHT-INDUCED AGGREGATION OF NANOPARTICLES FUNCTIONALIZED WITH 7-AMINO-4-METHYLCOUMARIN
Authors: ROSEN JOSHUA E. , JONES LYNDON , GU FRANK X.
Published: September 2012

Herein, we report on the modification of silica nanoparticles with the molecule 7-amino-4-methylcoumarin (AMC) via a hydrophilic dextran linker using reductive amination chemistry. The AMC-functionalized nanoparticles were shown to aggregate in response to irradiation by 350 nm UV light. The aggregation of the particles was studied using dynamic light scattering, UV-VIS spectroscopy, and transmission electron microscopy. The synthesis method described herein utilizes a classic reductive amination reaction, which can potentially be transferred to a variety of different types of nanoparticles. Particles displaying this behavior have many potential applications in the field of nanomedicine, as they can potentially allow one to modulate the particle size of a nanoparticle formulation after administration to the body. The AMC-functionalized particles studied in this report serve as a convincing proof-of-concept for synthesizing light-responsive nanoparticles.
Circulating microRNAs as diagnostic biomarkers for cardiovascular diseases
Authors: Tijsen Anke J. , Pinto Yigal M. , Creemers Esther E.
Published: September 2012

One of the major challenges in cardiovascular disease is the identification of reliable clinical biomarkers that can be routinely measured in plasma. MicroRNAs (miRNAs) were recently discovered to circulate in the bloodstream in a remarkably stable form. Because of their stability and often tissue- and disease-specific expression and the possibility to measure them with high sensitivity and specificity, miRNAs are emerging as new diagnostic biomarkers. In this review we will provide an overview of the potential of circulating miRNAs as biomarkers for a wide range of cardiovascular diseases such as coronary artery disease, myocardial infarction, hypertension, heart failure, viral myocarditis, and type-2 diabetes mellitus. Furthermore, we will discuss the challenges with regard to further validation in large patient cohorts, and we will discuss how the measurement of multiple miRNAs simultaneously might improve the accuracy of the diagnostic test.
Time course of right ventricular pressure-overload induced myocardial fibrosis: relationship to changes in fibroblast postsynthetic procollagen processing
Authors: Baicu Catalin F. , Li Jiayu , Zhang Yuhua , Kasiganesan Harinath , Cooper George , Zile Michael R. , Bradshaw Amy D.
Published: September 2012

Myocardial fibrillar collagen is considered an important determinant of increased ventricular stiffness in pressure-overload (PO)-induced cardiac hypertrophy. Chronic PO was created in feline right ventricles (RV) by pulmonary artery banding (PAB) to define the time course of changes in fibrillar collagen content after PO using a nonrodent model and to determine whether this time course was dependent on changes in fibroblast function. Total, soluble, and insoluble collagen (hydroxyproline), collagen volume fraction (CVF), and RV end-diastolic pressure were assessed 2 days and 1, 2, 4, and 10 wk following PAB. Fibroblast function was assessed by quantitating the product of postsynthetic processing, insoluble collagen, and levels of SPARC (secreted protein acidic and rich in cysteine), a protein that affects procollagen processing. RV hypertrophic growth was complete 2 wk after PAB. Changes in RV collagen content did not follow the same time course. Two weeks after PAB, there were elevations in total collagen (control RV: 8.84 ± 1.03 mg/g vs. 2-wk PAB: 11.50 ± 0.78 mg/g); however, increased insoluble fibrillar collagen, as measured by CVF, was not detected until 4 wk after PAB (control RV CVF: 1.39 ± 0.25% vs. 4-wk PAB: 4.18 ± 0.87%). RV end-diastolic pressure was unchanged at 2 wk, but increased until 4 wk after PAB. RV fibroblasts isolated after 2-wk PAB had no changes in either insoluble collagen or SPARC expression; however, increases in insoluble collagen and in levels of SPARC were detected in RV fibroblasts from 4-wk PAB. Therefore, the time course of PO-induced RV hypertrophy differs significantly from myocardial fibrosis and diastolic dysfunction. These temporal differences appear dependent on changes in fibroblast function.