bluuebunny/crossref_metadata_2025 huggingface dataset:
Nanostructure fabrication by self-assembly of block copolymers on three-dimensional diamondlike carbon structures
Authors: Mino Hiroyuki , Kometani Reo , Warisawa Shin-ichi , Ishihara Sunao
Published: November 2010

The block copolymer self-assembly has the potential to form nanoscale periodic patterns on three-dimensional (3D) nanostructures and nanomaterials. However, block copolymer self-assembly processes have only been examined on two-dimensional flat plane substrates. Forming copolymer nanostructures onto 3D structures would extend the applicability of these nanoscale patterns to 3D wiring for electric circuits and 3D nanomechanical devices. Herein, we investigate the formation process of nanopatterns of block copolymers onto 3D structures. A “dip-coating process” enables the block copolymer to self-assemble onto 3D structures. In addition, treatment with materials possessing a large surface energy effectively forms regular and dense nanoscale patterns onto a 3D diamondlike carbon structure. Moreover, self-assembled patterns are formed even if the angle of the slope of the 3D structure is changed.
Monte Carlo calculation of imaging doses from diagnostic multidetector CT and kilovoltage cone‐beam CT as part of prostate cancer treatment plans
Authors: Ding Aiping , Gu Jianwei , Trofimov Alexei V. , Xu X. George
Published: December 2010

Purpose:

To calculate imaging doses to the rectum, bladder, and femoral heads as part of a prostate cancer treatment plans, assuming an image guided radiation therapy (IGRT) procedure involving either the multidetector CT (MDCT) or kilovoltage cone‐beam CT (kV CBCT).

Methods:

This study considered an IGRT treatment plan for a prostate carcinoma patient involving 50.4 Gy from 28 initial fractions and a boost of 28.8 Gy from 16 fractions. A total of 45 CT imaging procedures, each involving a MDCT or a kV CBCT scan procedure, were carefully modeled using theMCNPX code version 2.5.0. The MDCT scanner model is based on the GE LightSpeed 16‐MDCT scanner and the kV CBCT scanner model is based on the Varian On‐Board Imager using parameters reported by the CT manufacturers and literatures. A patient‐specific treatment planning CT data set was used to construct the phantom for the dose calculation. The target, organs‐at‐risk (OARs), and background voxels in the CT data set were categorized into six tissue types according to CT numbers for Monte Carlo calculations.

Results:

For a total of 45 imaging procedures, it was found that the rectum received 78.4 and 76.7 cGy from MDCT and kV CBCT, respectively. The bladder received slightly greater doses of 82.4 and 77.9 cGy, while the femoral heads received much higher doses of 182.3 and 141.3 cGy from MDCT and kV CBCT, respectively. To investigate the impact of these imaging doses on treatment planning, OAR doses from MDCT or kV CBCT imaging procedures were added to the corresponding dose matrix reported by the original treatment plans to construct dose volume histograms. It was found that after the imaging dose is added, the rectum volumes irradiated to 75 and 70 Gy increased from 13.9% and 21.2%, respectively, in the original plan to 14.8% and 21.8%. The bladder volumes receiving 80 Gy increased to 4.6% from 4.1% in the original plan and the volume receiving 75 Gy increased to 7.9% from 7.5%. All values remained within the tolerance levels:, for rectum and , for bladder. The irradiation of femoral heads was also acceptable with no volume receiving .

Conclusions:

IGRT procedures can irradiate the OARs to an imaging dose level that is great enough to require careful evaluation and perhaps even adjustment of original treatment planning in order to still satisfy the dose constraints. This study only considered one patient CT because the CT x rays cover a relatively larger volume of the body and the dose distribution is considerably more uniform than those associated with the therapeutic beams. As a result, the dose to an organ from CT imaging doses does not vary much from one patient to the other for the same CT settings. One factor that would potentially affect such CT dose level is the size of the patient body. More studies are needed to develop accurate and convenient methods of accounting for the imaging doses as part of treatment planning.
In vivo small animal imaging: Current status and future prospects
Authors: Kagadis George C. , Loudos George , Katsanos Konstantinos , Langer Steve G. , Nikiforidis George C.
Published: December 2010

The use of small animal models in basic and preclinical sciences constitutes an integral part of testing new pharmaceutical agents prior to commercial translation to clinical practice. Whole‐body small animal imaging is a particularly elegant and cost‐effective experimental platform for the timely validation and commercialization of novel agents from the bench to the bedside. Biomedical imaging is now listed along with genomics, proteomics, and metabolomics as an integral part of biological and medical sciences. Miniaturized versions of clinical diagnostic modalities, including but not limited to microcomputed tomography, micromagnetic resonance tomography, microsingle‐photon‐emission tomography, micropositron‐emission tomography, optical imaging, digital angiography, and ultrasound, have all greatly improved our investigative abilities to longitudinally study various experimental models of human disease in mice and rodents. After an exhaustive literature search, the authors present a concise and critical review of in vivo small animal imaging, focusing on currently available modalities as well as emerging imaging technologies on one side and molecularly targeted contrast agents on the other. Aforementioned scientific topics are analyzed in the context of cancer angiogenesis and innovative antiangiogenic strategies under‐the‐way to the clinic. Proposed hybrid approaches for diagnosis and targeted site‐specific therapy are highlighted to offer an intriguing glimpse of the future.
Telerobotic system concept for real‐time soft‐tissue imaging during radiotherapy beam delivery
Authors: Schlosser Jeffrey , Salisbury Kenneth , Hristov Dimitre
Published: December 2010

Purpose:

The curative potential of external beam radiation therapy is critically dependent on having the ability to accurately aim radiation beams at intended targets while avoiding surrounding healthy tissues. However, existing technologies are incapable of real‐time, volumetric, soft‐tissue imaging during radiation beam delivery, when accurate target tracking is most critical. The authors address this challenge in the development and evaluation of a novel, minimally interfering, telerobotic ultrasound (U.S.) imaging system that can be integrated with existing medical linear accelerators (LINACs) for therapy guidance.

Methods:

A customized human‐safe robotic manipulator was designed and built to control the pressure and pitch of an abdominal U.S. transducer while avoiding LINAC gantry collisions. A haptic device was integrated to remotely control the robotic manipulator motion and U.S. image acquisition outside the LINAC room. The ability of the system to continuously maintain high quality prostate images was evaluated in volunteers over extended time periods. Treatment feasibility was assessed by comparing a clinically deployed prostate treatment plan to an alternative plan in which beam directions were restricted to sectors that did not interfere with the transabdominal U.S. transducer. To demonstrate imaging capability concurrent with delivery, robot performance and U.S. target tracking in a phantom were tested with a 15 MV radiation beam active.

Results:

Remote image acquisition and maintenance of image quality with the haptic interface was successfully demonstrated over 10 min periods in representative treatment setups of volunteers. Furthermore, the robot's ability to maintain a constant probe force and desired pitch angle was unaffected by the LINAC beam. For a representative prostate patient, the dose‐volume histogram (DVH) for a plan with restricted sectors remained virtually identical to the DVH of a clinically deployed plan. With reduced margins, as would be enabled by real‐time imaging, gross tumor volume coverage was identical while notable reductions of bladder and rectal volumes exposed to large doses were possible. The quality of U.S. images obtained during beam operation was not appreciably degraded by radiofrequency interference and 2D tracking of a phantom object in U.S. images obtained with the beam on/off yielded no significant differences.

Conclusions:

Remotely controlled robotic U.S. imaging is feasible in the radiotherapy environment and for the first time may offer real‐time volumetric soft‐tissue guidance concurrent with radiotherapy delivery.
Correction of breathing‐induced errors in magnetic resonance thermometry of hyperthermia using multiecho field fitting techniques
Authors: Wyatt Cory R. , Soher Brian J. , MacFall James R.
Published: December 2010

Purpose:

Breathing motion can create large errors when performing magnetic resonance (MR) thermometry of the breast. Breath holds can be used to minimize these errors, but not eliminate them. Between breath holds, the referenceless method can be used to further reduce errors by relying on regions of nonheated fatty tissue surrounding the heated region. When the surrounding tissue is heated (i.e., for a hyperthermia treatment), errors can result due to phase changes of the small amounts of water in the tissue. Therefore, an extension of the referenceless method is proposed which fits for the field in fatty tissue independent of temperature change and extrapolates it to the water‐rich regions.

Methods:

Nonheating experiments were performed with male volunteers performing breath holds on top of a phantom mimicking a breast with a tumor. Heating experiments were also conducted with the same phantom while mechanically simulated breath holds were performed. A nonheating experiment was also performed with a healthy female breast. For each experiment, a nonlinear fitting algorithm was used to fit for temperature change and field inside of the fatty tissue. The field changes were then extrapolated into water‐rich (tumor) portions of the image using a least‐squares fit to a fifth‐order equation, to correct for field changes due to breath hold changes. Similar results were calculated using the image phase, to mimic the use of the referenceless method.

Results:

Phantom results showed large reduction of mean error and standard deviation. In the non‐heating experiments, the traditional referenceless method and our extended method both corrected by similar amounts. However, in the heating experiments, the average deviation of the temperature calculated with the extended method from a fiber optic probe temperature was approximately 50% less than the deviation with the referenceless method. The in vivo breast results demonstrated reduced standard deviation and mean.

Conclusions:

In this paper, we have developed an extension of the referenceless method to correct for breathing errors using multiecho fitting methods to fit for the field in the fatty tissue and using measured field changes as references to extrapolate field corrections into a water‐only (tumor) region. This technique has been validated in a number of situations, and in all cases, the correction method has been shown to greatly reduce temperature error in water‐rich regions. The method has also been shown to be an improvement over similar methods that use image phase changes instead of field changes, particularly when temperature changes are induced.
Different Genetic Elements Carrying the
tet
(W) Gene in Two Human Clinical Isolates of
Streptococcus suis
Authors: Palmieri Claudio , Princivalli Maria Stella , Brenciani Andrea , Varaldo Pietro E. , Facinelli Bruna
Published: November 2010

The genetic support for
tet
(W), an emerging tetracycline resistance determinant, was studied in two strains of
Streptococcus suis
, SsCA and SsUD, both isolated in Italy from patients with meningitis. Two completely different
tet
(W)-carrying genetic elements, sharing only a
tet
(W)-containing segment barely larger than the gene, were found in the two strains. The one from strain SsCA was nontransferable, and aside from an
erm
(B)-containing insertion, it closely resembled a genomic island recently described in an
S. suis
Chinese human isolate in sequence, organization, and chromosomal location. The
tet
(W)-carrying genetic element from strain SsUD was transferable (at a low frequency) and, though apparently noninducible following mitomycin C treatment, displayed a typical phage organization and was named ΦSsUD.1. Its full sequence was determined (60,711 bp), the highest BLASTN score being
Streptococcus pyogenes
Φm46.1. ΦSsUD.1 exhibited a unique combination of antibiotic and heavy metal resistance genes. Besides
tet
(W), it contained a MAS (macrolide-aminoglycoside-streptothricin) fragment with an
erm
(B) gene having a deleted leader peptide and a
cadC
/
cadA
cadmium efflux cassette. The MAS fragment closely resembled the one recently described in pneumococcal transposons Tn
6003
and Tn
1545
. These resistance genes found in the ΦSsUD.1 phage scaffold differed from, but were in the same position as, cargo genes carried by other streptococcal phages. The chromosome integration site of ΦSsUD.1 was at the 3′ end of a conserved tRNA uracil methyltransferase (
rum
) gene. This site, known to be an insertional hot spot for mobile elements in
S. pyogenes
, might play a similar role in
S. suis
.
Detection of Airborne Lactococcal Bacteriophages in Cheese Manufacturing Plants
Authors: Verreault Daniel , Gendron Louis , Rousseau Geneviève M. , Veillette Marc , Massé Daniel , Lindsley William G. , Moineau Sylvain , Duchaine Caroline
Published: November 2010

The dairy industry adds starter bacterial cultures to heat-treated milk to control the fermentation process during the manufacture of many cheeses. These highly concentrated bacterial populations are susceptible to virulent phages that are ubiquitous in cheese factories. In this study, the dissemination of these phages by the airborne route and their presence on working surfaces were investigated in a cheese factory. Several surfaces were swabbed, and five air samplers (polytetrafluoroethylene filter, polycarbonate filter, BioSampler, Coriolis cyclone sampler, and NIOSH two-stage cyclone bioaerosol personal sampler) were tested. Samples were then analyzed for the presence of two
Lactococcus lactis
phage groups (936 and c2), and quantification was done by quantitative PCR (qPCR). Both lactococcal phage groups were found on most swabbed surfaces, while airborne phages were detected at concentrations of at least 10
3
genomes/m
3
of air. The NIOSH sampler had the highest rate of air samples with detectable levels of lactococcal phages. This study demonstrates that virulent phages can circulate through the air and that they are ubiquitous in cheese manufacturing facilities.
Substantiation in
Enterococcus faecalis
of Dose-Dependent Resistance and Cross-Resistance to Pore-Forming Antimicrobial Peptides by Use of a Polydiacetylene-Based Colorimetric Assay
Authors: Mehla Jitender , Sood S. K.
Published: November 2010

A better understanding of the antimicrobial peptide (AMP) resistance mechanisms of bacteria will facilitate the design of effective and potent AMPs. Therefore, to understand resistance mechanisms and for
in vitro
assessment, variants of
Enterococcus faecalis
that are resistant to different doses of the fungal AMP alamethicin (Alm
r
) were selected and characterized. The resistance developed was dose dependent, as both doses of alamethicin and degrees of resistance were colinear. The formation of bacterial cell aggregates observed in resistant cells may be the prime mechanism of resistance because overall, a smaller cell surface in aggregated cells is exposed to AMPs. Increased rigidity of the membranes of Alm
r
variants, because of their altered fatty acids, was correlated with limited membrane penetration by alamethicin. Thus, resistance developed against alamethicin was an adaptation of the bacterial cells through changes in their morphological features and physiological activity and the composition of membrane phospholipids. The Alm
r
variants showed cross-resistance to pediocin, which indicated that resistance developed against both AMPs may share a mechanism, i.e., an alteration in the cell membrane. High percentages of colorimetric response by both AMPs against polydiacetylene/lipid biomimetic membranes of Alm
r
variants confirmed that altered phospholipid and fatty acid compositions were responsible for acquisition of resistance. So far, this is the only report of quantification of resistance and cross-resistance using an
in vitro
colorimetric approach. Our results imply that a single AMP or AMP analog may be effective against bacterial strains having a common mechanism of resistance. Therefore, an understanding of resistance would contribute to the development of a single efficient, potent AMP against resistant strains that share a mechanism of resistance.
Interaction of Transcriptional Repressor ArgR with Transcriptional Regulator FarR at the
argB
Promoter Region in
Corynebacterium glutamicum
Authors: Lee Soo Youn , Park Jae-Min , Lee Jin Hyung , Chang Suk-Tai , Park Jin-Soo , Kim Yang-Hoon , Min Jiho
Published: November 2010

In
Corynebacterium glutamicum
, the ArgR protein, a transcriptional repressor, affects the expression level of the
argB
gene through binding to its promoter region. The
argB
promoter region (positions −77 to −25) has been found by
in vitro
electrophoretic mobility shift assay (EMSA) results and
in silico
analysis to be important for the DNA binding of ArgR. Proline supplementation prevented the DNA binding of ArgR to the
argB
promoter region and triggered an increase of the
argB
mRNA level. Additional mutational analyses of the
argB
promoter region found nucleotides critical for ArgR binding (G located at position −58, C at position −55, and A at position −41 of the
argB
promoter) in that region. Another transcriptional repressor, FarR, was also demonstrated to bind to the
argB
promoter region. This binding was delimited to positions −57 to −77 on the
argB
promoter. FarR has only one putative binding domain located at positions −57 to −77, but this region exactly overlapped with the binding region located from positions −55 to −77 for the binding of ArgR within the
argB
promoter; thus, if ArgR bound with the
argB
promoter first, the binding of FarR was not observed in this region. However, if FarR bound to the binding domain located at positions −57 to −77 first, ArgR could bind other binding sites located at positions −49 to −25 within the
argB
promoter. Finally, this study suggests that ArgR can affect FarR binding to the
argB
promoter region, as protein binding is dominated by the protein most able to do so.
New Approach To Produce Water Free of Bacteria, Viruses, and Halogens in a Recyclable System
Authors: Ahmed Abd El-Shafey I. , Cavalli Gabriel , Bushell Michael E. , Wardell John N. , Pedley Steve , Charles Katarina , Hay John N.
Published: November 2010

The antimicrobial activity of a new cross-linkedN-halamine polymer against bacteria and viruses was evaluated. The polymer achieved a 9-log10reduction of bacteria (bothEscherichia coliandStaphylococcus aureus) in 1.5 h and a 5-log10reduction of bacteriophage PRD1 in 3 h. At the same time, the ability of the nonhalogenated polymer to trap halide ions was examined. The polymer was incorporated into a multifiltration system to study the ability to produce water free of bacteria, viruses, and halide ions. The antimicrobial activity, useful lifetime, halide ion level, and recycling possibilities of the system were quantified on a laboratory scale. A design for a large-scale multifiltration system based on this polymer is proposed.
The Candida albicans Sur7 Protein Is Needed for Proper Synthesis of the Fibrillar Component of the Cell Wall That Confers Strength
Authors: Wang Hong X. , Douglas Lois M. , Aimanianda Vishukumar , Latgé Jean-Paul , Konopka James B.
Published: November 2010

The
Candida albicans
plasma membrane plays important roles in interfacing with the environment, morphogenesis, and cell wall synthesis. The role of the Sur7 protein in cell wall structure and function was analyzed, since previous studies showed that this plasma membrane protein is needed to prevent abnormal intracellular growth of the cell wall. Sur7 localizes to stable patches in the plasma membrane, known as MCC (membrane compartment occupied by Can1), that are associated with eisosome proteins. The
sur7
Δ mutant cells displayed increased sensitivity to factors that exacerbate cell wall defects, such as detergent (SDS) and the chitin-binding agents calcofluor white and Congo red. The
sur7
Δ cells were also slightly more sensitive to inhibitors that block the synthesis of cell wall chitin (nikkomycin Z) and β-1,3-glucan (caspofungin). In contrast, Fmp45, a paralog of Sur7 that also localizes to punctate plasma membrane patches, did not have a detectable role in cell wall synthesis. Chemical analysis of cell wall composition demonstrated that
sur7
Δ cells contain decreased levels of β-glucan, a glucose polymer that confers rigidity on the cell wall. Consistent with this,
sur7
Δ cells were more sensitive to lysis, which could be partially rescued by increasing the osmolarity of the medium. Interestingly, Sur7 is present in static patches, whereas β-1,3-glucan synthase is mobile in the plasma membrane and is often associated with actin patches. Thus, Sur7 may influence β-glucan synthesis indirectly, perhaps by altering the functions of the cell signaling components that localize to the MCC and eisosome domains.
Rapid Tagging and Integration of Genes in Giardia intestinalis
Authors: Gourguechon Stéphane , Cande W. Zacheus
Published: November 2010

We developed a series of plasmids that allow C-terminal tagging of any gene in its endogenous locus in
Giardia intestinalis
, with different epitope tags (triple hemagglutinin [3HA] and triple Myc [3Myc]) and selection markers (puromycin, neomycin, and a newly developed marker, blasticidin). Using these vectors, cyclin B and aurora kinase were tagged, expressed, and localized.
TheTreponema denticolaChymotrypsin-Like Protease Dentilisin Induces Matrix Metalloproteinase-2-Dependent Fibronectin Fragmentation in Periodontal Ligament Cells
Authors: Miao Di , Fenno J. Christopher , Timm John C. , Joo Nam Eok , Kapila Yvonne L.
Published: November 2010

Periodontal disease is a bacterially mediated chronic inflammatory disease that results in destruction of the periodontal ligament (PDL) and alveolar bone that surround and support the dentition. While their precise roles are not well understood, periodontal pathogens, includingTreponema denticola, are believed to initiate the destructive inflammatory responses and dysregulation of tissue homeostasis that characterize the disease. These responses are believed to result from both proinflammatory effects of acylated bacterial membrane components (lipopolysaccharides and lipoproteins) and degradative effects of secreted bacterial proteases. Host-derived matrix metalloproteinases (MMPs) are key enzymes both in tissue homeostasis and tissue destruction. MMP expression is modulated in part by specific proteolytic fragments of fibronectin (FN), which are associated with periodontal disease. FN is a predominant extracellular matrix component in the periodontium. We examined the ability ofTreponema denticolaand its acylated outer membrane PrtP protease complex to induce both activation of MMP-2 and generation of FN fragments in human PDL cell culture supernatants.T. denticolaparent and isogenic mutant strains, as well as MMP-2 small interfering RNA and specific inhibitors of MMP-2 and PrtP activity, were used to examine protein expression, gelatinolytic activity, and FN fragmentation in culture supernatants.T. denticolaand its purified protease induced both MMP-2 activation and FN fragmentation. Here, we demonstrate that PrtP proteolytic activity induces the activation of MMP-2 and that active MMP-2 is required for FN fragmentation. These results suggest a specific mechanism by which theT. denticolaprotease may disrupt homeostatic processes required for the maintenance of periodontal health.
Autocrine Effects of Interleukin-6 Mediate Acute-Phase Proinflammatory and Tissue-Reparative Transcriptional Responses of Canine Bladder Mucosa
Authors: Wood Michael W. , Breitschwerdt Edward B. , Gookin Jody L.
Published: November 2010

During early urinary tract infection (UTI) the interplay between invading bacteria and the urothelium elicits a mucosal response aimed at clearing infection. Unfortunately, the resultant inflammation and associated local tissue injury are responsible for patient symptoms. Interleukin-6 (IL-6), a cytokine released during acute UTI, has both pro- and anti-inflammatory effects on other body systems. Within the urothelium, the IL-6 native-tissue origin, the target cell type(s), and ultimate effect of the cytokine on target cells are largely unknown. In the present study we modeled the UTI IL-6 responseex vivousing canine bladder mucosa mounted in Ussing chambers to determine the inflammatory and reparative role of IL-6. We demonstrated that uropathogenicEscherichia coliinfection stimulates the synthesis of IL-6 by all urothelial cell layers, with the urothelial cells alone representing the only site of unequivocal IL-6 receptor expression. Autocrine effects of IL-6 were supported by the activation of urothelial STAT3 signaling and SOCS3 expression. Using exogenous IL-6, a microarray approach, and quantitative reverse transcriptase PCR (q-RT-PCR), 5 target genes (tumor necrosis factor alpha, interleukin-1β, matrix metallopeptidase 2, heparan sulfated-glucosaminyl 3-O-sulfotransferase 3A1, and hyaluronan synthase 2) that have direct or indirect roles in promoting a proinflammatory state were identified. Two of these genes, heparan sulfated-glucosaminyl 3-O-sulfotransferase 3A1 and hyaluronan synthase 2, are also potentially important mediators of wound repair via the production of glycosaminoglycan components. These findings suggest that IL-6 secretion during acute UTI may serve a dual biological role by initiating the inflammatory response while also repairing urothelial defenses.
Sustaining N
2
-Dependent Growth in the Presence of CO
Authors: Kerby Robert L. , Roberts Gary P.
Published: November 2010

Low levels of carbon monoxide inhibit the N
2
-dependent growth of
Rhodospirillum rubrum
unless the ∼100-residue CowN protein is expressed. Expression requires the CO-responsive regulator RcoM and is maximal in cells grown in the presence of CO and a poor nitrogen source, consistent with the role of CowN in N
2
fixation.
Rotavirus Disrupts Calcium Homeostasis by NSP4 Viroporin Activity
Authors: Hyser Joseph M. , Collinson-Pautz Matthew R. , Utama Budi , Estes Mary K.
Published: December 2010

Many viruses alter intracellular calcium homeostasis. The rotavirus nonstructural protein 4 (NSP4), an endoplasmic reticulum (ER) transmembrane glycoprotein, increases intracellular levels of cytoplasmic Ca
2+
([Ca
2+
]cyto) through a phospholipase C-independent pathway, which is required for virus replication and morphogenesis. However, the NSP4 domain and mechanism that increases [Ca
2+
]cyto are unknown. We identified an NSP4 domain (amino acids [aa] 47 to 90) that inserts into membranes and has structural characteristics of viroporins, a class of small hydrophobic viral proteins that disrupt membrane integrity and ion homeostasis to facilitate virus entry, assembly, or release. Mutational analysis showed that NSP4 viroporin activity was mediated by an amphipathic α-helical domain downstream of a conserved lysine cluster. The lysine cluster directed integral membrane insertion of the viroporin domain and was critical for viroporin activity. In epithelial cells, expression of wild-type NSP4 increased the levels of free cytoplasmic Ca
2+
by 3.7-fold, but NSP4 viroporin mutants maintained low levels of [Ca
2+
]cyto, were retained in the ER, and failed to form cytoplasmic vesicular structures, called puncta, which surround viral replication and assembly sites in rotavirus-infected cells. When [Ca
2+
]cyto was increased pharmacologically with thapsigargin, viroporin mutants formed puncta, showing that elevation of calcium levels and puncta formation are distinct functions of NSP4 and indicating that NSP4 directly or indirectly responds to elevated cytoplasmic calcium levels. NSP4 viroporin activity establishes the mechanism for NSP4-mediated elevation of [Ca
2+
]cyto, a critical event that regulates rotavirus replication and virion assembly.

IMPORTANCE
Rotavirus is the leading cause of viral gastroenteritis in children and young animals. Rotavirus infection and expression of nonstructural protein 4 (NSP4) alone dramatically increase cytosolic calcium, which is essential for replication and assembly of infectious virions. This work identifies the intracellular mechanism by which NSP4 disrupts calcium homeostasis by showing that NSP4 is a viroporin, a class of virus-encoded transmembrane pores. Mutational analyses identified residues critical for viroporin activity. Viroporin mutants did not elevate the levels of cytoplasmic calcium in mammalian cells and were maintained in the endoplasmic reticulum rather than forming punctate vesicular structures that are critical for virus replication and morphogenesis. Pharmacological elevation of cytoplasmic calcium levels rescued puncta formation in viroporin mutants, demonstrating that elevation of calcium levels and puncta formation are distinct NSP4 functions. While viroporins typically function in virus entry or release, elevation of calcium levels by NSP4 viroporin activity may serve as a regulatory function to facilitate virus replication and assembly.
FtsZ in Bacterial Cytokinesis: Cytoskeleton and Force Generator All in One
Authors: Erickson Harold P. , Anderson David E. , Osawa Masaki
Published: November 2010

FtsZ, a bacterial homolog of tubulin, is well established as forming the cytoskeletal framework for the cytokinetic ring. Recent work has shown that purified FtsZ, in the absence of any other division proteins, can assemble Z rings when incorporated inside tubular liposomes. Moreover, these artificial Z rings can generate a constriction force, demonstrating that FtsZ is its own force generator. Here we review light microscope observations of how Z rings assemble in bacteria. Assembly begins with long-pitch helices that condense into the Z ring. Once formed, the Z ring can transition to short-pitch helices that are suggestive of its structure. FtsZ assemblesin vitrointo short protofilaments that are ∼30 subunits long. We present models for how these protofilaments might be further assembled into the Z ring. We discuss recent experiments on assembly dynamics of FtsZin vitro, with particular attention to how two regulatory proteins, SulA and MinC, inhibit assembly. Recent efforts to develop antibacterial drugs that target FtsZ are reviewed. Finally, we discuss evidence of how FtsZ generates a constriction force: by protofilament bending into a curved conformation.
Visual depictions of female genitalia differ depending on source
Authors: Howarth Helena , Sommer Volker , Jordan Fiona M
Published: November 2010

Very little research has attempted to describe normal human variation in female genitalia, and no studies have compared the visual images that women might use in constructing their ideas of average and acceptable genital morphology to see if there are any systematic differences. The objective of the present work was to determine if visual depictions of the vulva differed according to their source so as to alert medical professionals and their patients to how these depictions might capture variation and thus influence perceptions of ‘normality’. A comparative analysis was conducted by measuring (a) published visual materials from human anatomy textbooks in a university library, (b) feminist publications (print and online) depicting vulval morphology and (c) online pornography, focusing on the most visited and freely accessible sites in the UK. Post hoc tests showed that labial protuberance was significantly less (p<0.001, equivalent to approximately 7 mm) in images from online pornography compared to feminist publications. All five measures taken of vulval features were significantly correlated (p<0.001) in the online pornography sample, indicating a less varied range of differences in organ proportions than the other sources where not all measures were correlated. Women and health professionals should be aware that specific sources of imagery may depict different types of genital morphology and may not accurately reflect true variation in the population, and consultations for genital surgeries should include discussion about the actual and perceived range of variation in female genital morphology.
Diet in pregnancy, 1930–1960: a shifting social, political and scientific concern: Figure 1
Authors: Sultan Najia
Published: November 2010

The diet of expectant mothers was a significant issue of social, political and scientific concern between 1930 and 1960. However, while histories of maternity services and nutritional science are independently available, no existing study addresses the nutrition of expectant mothers in this period. Between 1900 and 1930, maternal mortality rates were rising despite improving clinical antenatal provisions. Breakthroughs in nutritional science resulted in the identification of key dietary components, while changing social attitudes meant hunger was increasingly being seen as a humanitarian issue requiring a modern solution. As a result, the diet of expectant mothers first began to be addressed as a social concern in the 1930s. It subsequently made a transition into official policy as part of wartime rationing. The government entirely changed its attitude to maternal nutrition in a beneficial and successful way during the war; conferring to modern historians another example of war being a generator of change. Diet in pregnancy finally became the concern of the scientific community post-war, as illustrated by the work of the Royal College of Obstetrics and Gynaecology Nutrition Committee for Pregnancy, whose papers are considered for the first time here. This paper charts the rise of diet in pregnancy as a concern and considers the contributions of different communities involved between 1930 and 1960. It also notes that the actual recommended diet stayed the same. Thus while diet is the subject here, discussion focuses on why there were such distinct rearrangements of social, political and scientific forces around an issue that itself remained unchanged.
Effectiveness of tax and price policies in tobacco control: Table 1
Authors: Chaloupka Frank J , Straif Kurt , Leon Maria E
Published: November 2010

Objective

Over 20 experts on economics, epidemiology, public policy and tobacco control were asked by the International Agency for Research on Cancer (IARC) to evaluate the strength of the available evidence on the effects of tax and price policies to prevent and reduce tobacco use.

Methods

Draft papers presenting and assessing the evidence on the following topics were developed by the experts in an 8-month period prior to the meeting: tobacco industry pricing strategies and tax related lobbying; tax, price and aggregate demand for tobacco; tax, price and adult tobacco use, use among young people and use among the poor; tax avoidance and tax evasion; and the economic and health impact of tobacco taxation. Subsequently, papers were peer reviewed, revised and resubmitted for final discussion at a 6-day meeting at IARC in Lyon, France, where a consensus evaluation of 18 concluding statements using the pre-established criteria of the IARC Cancer Prevention Handbooks took place. Studies published (or accepted for publication) in the openly available scientific literature were the main source of evidence for the review and evaluation; other types of publications were included when appropriate.

Results

In support of 12 of the 18 conclusions, the experts agreed that there was sufficient evidence of effectiveness of increased tobacco excise taxes and prices in reducing overall tobacco consumption and prevalence of tobacco use and improvement of public health, including by preventing initiation and uptake among young people, promoting cessation among current users and lowering consumption among those who continue to use. For the remaining six concluding statements the evidence was strong (four statements) or limited (two statements).

Conclusions

The evidence presented and assessed in IARC Handbook volume 14 documents the effectiveness of tax and price policies in the control of tobacco use and improvement of public health.
SHAPE TRANSFORMATIONS OF A MODEL OF SELF-AVOIDING TRIANGULATED SURFACES OF SPHERE TOPOLOGY
Authors: KOIBUCHI HIROSHI
Published: November 2010

We study a surface model with a self-avoiding (SA) interaction using the canonical Monte Carlo simulation technique on fixed-connectivity (FC) triangulated lattices of sphere topology. The model is defined by an area energy, a deficit angle energy, and the SA potential. A pressure term is also included in the Hamiltonian. The volume enclosed by the surface is well defined because of the self-avoidance. We focus on whether or not the interaction influences the phase structure of the FC model under two different conditions of pressure Δp; zero and small negative. The results are compared with the previous results of the self-intersecting model, which has a rich variety of phases; the smooth spherical phase, the tubular phase, the linear phase, and the collapsed phase. We find that the influence of the SA interaction on the multitude of phases is almost negligible except for the evidence that no crumpled surface appears under Δp = 0 at least even in the limit of zero bending rigidity α → 0. The Hausdorff dimension is obtained in the limit of α → 0 and compared with previous results of SA models, which are different from the one in this paper.
EFFECT OF ROLLING MASSAGE ON THE VORTEX FLOW IN BLOOD VESSELS WITH LATTICE BOLTZMANN SIMULATION
Authors: YI HOU HUI
Published: November 2010

The rolling massage manipulation is a classic Chinese Medical Massage, which is a nature therapy in eliminating many diseases. Here, the effect of the rolling massage on the cavity flows in blood vessel under the rolling manipulation is studied by the lattice Boltzmann simulation. The simulation results show that the vortex flows are fully disturbed by the rolling massage. The flow behavior depends on the rolling velocity and the rolling depth. Rolling massage has a better effect on the flows in the cavity than that of the flows in a planar blood vessel. The result is helpful to understand the mechanism of the massage and develop the rolling techniques.
ON THE EQUILIBRIUM OF A STOCHASTIC NONLOCAL PDE POPULATION MODEL WITH STATE-SELECTIVE DELAY
Authors: ZHENG YAN , HUANG JIANHUA
Published: November 2010

This paper is devoted to the biological equilibrium of a stochastic nonlocal PDE population model with state-selective delay. By an improved dissipativity method and a delicate analysis of interaction of stochastic terms and delay terms, we obtain a unique equilibrium, which mixes exponentially. In order to check the validity of the model, we also investigate its stochastic stability.
INFINITELY MANY BROWNIAN GLOBULES WITH BROWNIAN RADII
Authors: FRADON MYRIAM , RŒLLY SYLVIE
Published: November 2010

We consider an infinite system of non-overlapping globules undergoing Brownian motions in ℝ3. The term globules means that the objects we are dealing with are spherical, but with a radius which is random and time-dependent. The dynamics is modelized by an infinite-dimensional stochastic differential equation with local time. Existence and uniqueness of a strong solution is proven for such an equation with fixed deterministic initial condition. We also find a class of reversible measures.
THE NUMERICAL AND ANALYTICAL SOLUTION OF PERISTALTIC FLOW OF A JEFFREY FLUID IN AN INCLINED TUBE WITH PARTIAL SLIP
Authors: NADEEM S. , AKBAR NOREEN SHER , NAZ TABINDA
Published: November 2010

In the present article, we have discussed the closed-form analytical and numerical solutions of the peristaltic flow of a Jeffrey fluid in an inclined tube with different viscosities and with different wave shapes. The closed-form analytical solutions have been computed by Adomian decomposition method and the numerical solutions have been calculated using finite difference technique. A comparison of numerical and analytical solutions have been presented and found a very good agreement between the two solutions. The expressions for pressure rise and friction forces are computed using numerical integration with the help of mathematics software. At the end various physical parameters appearing in the problem are shown pictorially and the results have been discussed in detail. The phenomena for different wave shape are also discussed.
THEORETICAL RESEARCH ON THE REACTION MECHANISM OF O + HCNO
Authors: MU DAN , LI JIAN-QUAN , ZHOU YI-HAN
Published: December 2010

We apply a theoretical method to study the O + HCNO reaction, in which the products Pi with i = 1, 2, …, 8 are involved. It is carried out by means of CCSD(T)/6-311G(d,p)//B3LYP/6-311G(d,p) + ZPVE computational method to detect a set of reasonable pathways. It shows that P5(H + NO + CO) and P8(HON + CO) are both the major product channel; in addition, there are some degrees of contributions from P1(HCO + NO) to form P5(H + NO + CO) ; P4(NH + CO2) is considered a minor product channel, and there are some degrees of contributions from P2(HNO + CO) to form P4(NH + CO2) ; whereas the other three channels, P3(NCO + OH) , P6(CNO + OH) , and P7(HCN + O2) are less favorable or even unfavorable. All these theoretical results are in harmony with the experimental facts.
A survey on the design, applications, and enhancements of application-layer overlay networks
Authors: Kurian Jinu , Sarac Kamil
Published: November 2010

This article presents a survey of recent advancements in application-layer overlay networks. Some of the most important applications that have been proposed for overlays include multicast, QoS support, denial-of-service (DoS) defense, and resilient routing. We look at some of the important approaches proposed for these applications and compare the advantages and disadvantages of these approaches. We also examine some of the enhancements that have been proposed in overlay topology design, enhanced routing performance, failure resistance, and the issues related to coexistence of overlay and native layers in the Internet. We conclude the article with a comment on the purist vs pluralist argument of overlay networks that has received much debate recently. Finally, we propose a new deployment model for service overlays that seeks to interpose between these two approaches.
Exploratory Analysis of Collaborative Web Accessibility Improvement
Authors: Sato Daisuke , Takagi Hironobu , Kobayashi Masatomo , Kawanaka Shinya , Asakawa Chieko
Published: November 2010

The Web is becoming a platform for daily activities and is expanding the opportunities for collaboration among people all over the world. The effects of these innovations are seen not only in major Web services such as wikis and social networking services but also in accessibility services. Collaborative accessibility improvement has great potential to make the Web more adaptive. Screen reader users, developers, site owners, and any Web volunteers who want to help the users are invited into the activities to improve accessibility in a timely manner. The Social Accessibility Project is an experimental service for a new needs-driven improvement model based on collaborative metadata authoring technologies. In 20 months, about 19,000 pieces of metadata were created for more than 3,000 Web pages through collaboration based on 355 requests submitted from users. We encountered many challenges as we sought to create a new mainstream approach and created distinctive features in new user interfaces to address some of these challenges. Although the new features increased user participation, serious issues remain. The productivity of the volunteers exceeded our expectations, but we found large and important problems in the users’ lack of awareness of their own accessibility problems. This is a critical problem for sustaining the active use of the service, because about 70% of the improvement starts with a request from a user. Helping users with visual impairments understand the actual issues is a crucial and challenging topic, and will lead to improved accessibility. We first introduce examples of collaboration, analyze several kinds of statistics on the activities of the users and volunteers of the pilot service, and then discuss our findings and challenges. Five future foci are considered: site-wide metadata authoring, encouraging active participation by users, quality management for the created metadata, metadata for dynamic HTML applications, and collaborations with site owners.
The Greenfoot Programming Environment
Authors: Kölling Michael
Published: November 2010

Greenfoot is an educational integrated development environment aimed at learning and teaching programming. It is aimed at a target audience of students from about 14 years old upwards, and is also suitable for college- and university-level education. Greenfoot combines graphical, interactive output with programming in Java, a standard, text-based object-oriented programming language. This article first describes Greenfoot and then goes on to discuss design goals and motivations, strengths and weaknesses of the system, and its relation to two environments with similar goals, Scratch and Alice.
Behavior-Level Observability Analysis for Operation Gating in Low-Power Behavioral Synthesis
Authors: Cong Jason , Liu Bin , Majumdar Rupak , Zhang Zhiru
Published: December 2010

Many techniques for power reduction in advanced RTL synthesis tools rely explicitly or implicitly on observability don’t-care conditions. In this article we propose a systematic approach to maximize the effectiveness of these techniques by generating power-friendly RTL descriptions in behavioral synthesis. This is done using
operation gating
, that is, explicitly adding a predicate to an operation based on its observability condition, so that the operation, once identified as unobservable at runtime, can be avoided using RTL power optimization techniques such as clock gating.

We first introduce the concept of behavior-level observability and its approximations in the context of behavioral synthesis. We then propose an efficient procedure to compute an approximated behavior-level observability of every operation in a dataflow graph. Unlike previous techniques which work at the bit level in Boolean networks, our method is able to perform analysis at the word level, and thus avoids most computation effort with a reasonable approximation. Our algorithm exploits the observability-masking nature of some Boolean operations, as well as the select operation, and allows certain forms of other knowledge to be considered for stronger observability conditions. The approximation is proved exact for (acyclic) dataflow graphs when non-Boolean operations other than select are treated as black boxes. The behavior-level observability condition obtained by our analysis can be used to guide the operation scheduler to optimize the efficiency of operation gating. In a set of experiments on real-world designs, our method achieves an average of 33.9% reduction in total power; it outperforms a previous method by 17.1% on average and gives close-to-optimal solutions on several designs. To the best of our knowledge, this is the first time behavior-level observability analysis and optimization are performed during behavioral synthesis in a systematic manner. We believe that our idea can be applied to compiler transformations in general.
WikiSym 2010
Authors: Ayers Phoebe
Published: November 2010

WikiSym 2010 (the 6th International Symposium on Wikis and Open Collaboration) was held on July 7--9th in Gdańsk, Poland, with an all-day Doctoral Symposium held on July 10th. WikiSym was co-located this year for the first time with Wikimania 2010, the international community conference of the Wikimedia Foundation, which was held from July 9th--11th in Gdańsk.