bluuebunny/crossref_metadata_2025 huggingface dataset:
Protection sociale et prévention sanitaire dans les pays en développement: apprécier l'impact des pensions et de l'assurance‐maladie sur la santé
Authors: Lloyd‐Sherlock Peter , Minicuci Nadia , Beard John , Chatterji Somnath
Published: December 2012

Dans cet article, nous évaluons dans quelle mesure le versement de pensions et l'assurance‐maladie permettent de prévenir les problèmes de santé au sein de la population âgée des pays en développement. Nous avançons que, jusqu'à une période récente, les grandes orientations définies en matière de protection sociale n'accordaient pas suffisamment de place à la prévention des risques pour la santé, donnant la priorité à la réduction de la pauvreté monétaire au moyen de transferts monétaires. Nous montrons que les responsables de l'action publique ne doivent pas partir du principe que l'octroi d'une pension de retraite se traduit systématiquement par une amélioration de l'état de santé des personnes âgées parce que peu de données valident ce postulat. Nous examinons ensuite les effets de l'extension des régimes d'assurance maladie aux personnes âgées sur leur santé, en nous intéressant plus particulièrement à l'hypertension. Nous indiquons, en nous appuyant sur de nouvelles données relatives au Ghana, au Mexique et à l'Afrique du Sud recueillies par l’Organisation mondiale de la santé, que les personnes âgées couvertes par une assurance‐maladie n'ont guère plus de chances que leurs homologues non assurées d'être conscientes de souffrir d'une affection comme l'hypertension et de bénéficier d'un traitement efficace. Néanmoins, qu'elle soit ou non couverte par une assurance‐maladie, la grande majorité de la population âgée atteinte d'hypertension ne bénéficie pas d'un traitement efficace. Ces difficultés d'accès aux soins sont davantage liées au fait que les personnes âgées n'ont pas conscience de leurs problèmes de santé et à des carences au niveau de l'offre de soins plutôt qu'à des obstacles financiers. Par conséquent, dans les pays en développement, notamment dans les zones rurales, les régimes de retraite ou d'assurance‐maladie ne peuvent induire une amélioration de l'état de santé des personnes âgées que s’ils s’accompagnent de programmes d'éducation pour la santé et de dépistage, et si l'offre de soins est adaptée. De surcroît, ces mesures doivent faire partie intégrante des stratégies de protection sociale classiques et non être conçues comme complémentaires de ces stratégies. Or, dans la pratique, la protection sociale et la promotion de la santé sont encore considérées comme des sphères presque entièrement distinctes l'une de l'autre, si bien que la mise au point de mesures globales se heurte à d'importantes barrières institutionnelles.
Prevention of root caries: a literature review of primary and secondary preventive agents
Authors: Gluzman Rima , Katz Ralph V. , Frey Barbara J. , McGowan Richard
Published: December 2012

Purpose

This literature review summarizes the effectiveness of the seven leading root caries preventive agents and provides recommendations for use of those agents in clinical practice with older adults and vulnerable elderly.

Method

Studies were eligible if they assessed the effectiveness of either fluoride, chlorhexidine, xylitol, amorphous calcium phosphate, sealants, saliva stimulators, or silver diamine fluoride to prevent/control root caries in an English language articles between 1979 and 2010.

Results

In the 31 eligible studies, the most effective primary (1°) prevention agents had reductions in RC incidence ranging from 72% to nearly 200% as compared to a placebo while for secondary (2°) prevention, the best agents demonstrated arrest rates between 67 and 80%.

Conclusion

For 1° prevention of root caries the recommended “best choice” is a 38% Silver Diamine Fluoride solution professionally applied annually, while for the 2° prevention of root caries, the recommended “best choice” is a 22,500 ppm Sodium Fluoride varnish professionally applied every 3 months.
The Effect of Aluminum in Solution on the Dissolution of Amorphous Silica and its Relation to Cementitious Systems
Authors: Chappex Théodore , Scrivener Karen L.
Published: December 2012

One of the most serious causes of degradation of concrete is the alkali–silica reaction. Amorphous silicates present in certain aggregates react with the alkaline pore solution of the concrete to form a gel, which absorbs water and swells, leading to the expansion of the concrete. It is known that the deleterious effects of ASR can be suppressed by the incorporation of supplementary cementitious materials in the concrete, but the mechanisms operating are not clear. In this article, we study a model system of amorphous silica plates in simulated pore solutions by X‐ray photoelectron spectroscopy (XPS), to demonstrate that aluminum in solution can directly suppress the dissolution of amorphous silica under the highly alkaline conditions found in concrete. XPS shows that aluminum species are incorporated into the framework of the silica structure. Scanning electron microscope (SEM) and atomic force microscope (AFM) images confirmed the reduction in dissolution of silica in solutions containing aluminum.
Gene–environment interaction in externalizing problems among adolescents: evidence from the Pelotas 1993 Birth Cohort Study
Authors: Kieling Christian , Hutz Mara H. , Genro Júlia P. , Polanczyk Guilherme V. , Anselmi Luciana , Camey Suzi , Hallal Pedro C. , Barros Fernando C. , Victora Cesar G. , Menezes Ana M. B. , Rohde Luis Augusto
Published: December 2012

Background:  The study of gene–environment interactions (G × E) is one of the most promising strategies to uncover the origins of mental disorders. Replication of initial findings, however, is essential because there is a strong possibility of publication bias in the literature. In addition, there is a scarcity of research on the topic originated from low‐ and middle‐income countries (LMIC). The aim of this study was to replicate G × E hypotheses for externalizing problems among adolescents in a middle‐income country.

Methods:  As part of the Pelotas 1993 Birth Cohort Study, 5,249 children were enrolled at birth and followed up to the age of 15 years, with an 85.7% retention rate. We sought an interaction between the homozygosity of the 10‐repeat allele at the dopamine transporter (DAT1) gene and prenatal maternal smoking in the development of hyperactivity problems during adolescence assessed by the Strengths and Difficulties Questionnaire. We also tested for an interaction between the uVNTR polymorphism at the monoamine oxidase A (MAOA) and the experience of childhood maltreatment in the occurrence of conduct problems among adolescent boys.

Results:  Although there was a clear association between prenatal maternal smoking and hyperactivity scores in adolescence (p < 0.001), no main genetic or interaction effects for the DAT1 gene were detected. Similarly, childhood maltreatment showed to be associated with conduct problems among boys (p < 0.001), with no observable main genetic or interaction effects for the MAOA gene.

Conclusions:  In the largest mental health G × E study performed in a LMIC to date, we did not replicate previous positive findings from the literature. Despite the presence of main environmental effects, there was no evidence of effect modification by genotype status. Additional replication efforts to measure G × E are needed to better understand the origins of mental health and illness, especially in LMIC.
Parental depressive and anxiety symptoms during pregnancy and attention problems in children: a cross‐cohort consistency study
Authors: Van Batenburg‐Eddes T. , Brion M.J. , Henrichs J. , Jaddoe V.W.V. , Hofman A. , Verhulst F.C. , Lawlor D.A. , Davey Smith G. , Tiemeier H.
Published: December 2012

Background:  Maternal depression and anxiety during pregnancy have been associated with offspring‐attention deficit problems.

Aim:  We explored possible intrauterine effects by comparing maternal and paternal symptoms during pregnancy, by investigating cross‐cohort consistency, and by investigating whether parental symptoms in early childhood may explain any observed intrauterine effect.

Methods:  This study was conducted in two cohorts (Generation R, n = 2,280 and ALSPAC, n = 3,442). Pregnant women and their partners completed questionnaires to assess symptoms of depression and anxiety. Child attention problems were measured in Generation R at age 3 with the Child Behavior Checklist, and in ALSPAC at age 4 with the Strengths and Difficulties Questionnaire.

Results:  In both cohorts, antenatal maternal symptoms of depression (Generation R: OR 1.23, 95% CI 1.05–1.43; ALSPAC: OR 1.33, 95% CI 1.19–1.48) and anxiety (Generation R: OR 1.24, 95% CI 1.06–1.46; ALSPAC: OR 1.32, 95% CI 1.19–1.47) were associated with a higher risk of child attention problems. In ALSPAC, paternal depression was also associated with a higher risk of child attention problems (OR 1.11, 95% CI 1.00–1.24). After adjusting for maternal symptoms after giving birth, antenatal maternal depression and anxiety were no longer associated with child attention problems in Generation R. Moreover, there was little statistical evidence that antenatal maternal and paternal depression and anxiety had a substantially different effect on attention problems of the child.

Conclusions:  The apparent intrauterine effect of maternal depression and anxiety on offspring‐behavioural problems may be partly explained by residual confounding. There was little evidence of a difference between the strength of associations of maternal and paternal symptoms during pregnancy with offspring‐attention problems. That maternal symptoms after childbirth were also associated with offspring‐behavioural problems may indicate a contribution of genetic influences to the association.
Antennal responses of Cydia pomonella (L.) exposed to surfaces treated with methoxyfenozide
Authors: Barrett B. A. , Keesey I. W. , Akbulut S. , Terrell Stamps W.
Published: December 2012

Electroantennogram (EAG) measurements were recorded from the antennae of male and female codling moth, Cydia pomonella L., to determine whether adult moths exposed to surfaces treated with the ecdysteroid agonist methoxyfenozide experience a decline in their antennal reception and thus olfactory sensitivity. Such a phenomenon would offer a possible mechanism for the previously reported decreased responsiveness from moths treated with methoxyfenozide to pheromone‐ and plant volatile‐based monitoring lures. Mean EAG data revealed that the antennae from methoxyfenozide‐treated male moths appear to be just as sensitive to various doses of synthetic codlemone as the antennae from the control and surfactant‐treated moths, but they appeared to be less sensitive to the pheromone component 12OH (collected from female effluvia) than the control male antennae. Mean male EAG responses to the pheromone components E8,E10‐12Al and codlemone collected from methoxyfenozide‐treated females were significantly less than the responses towards those two pheromone components collected from the control and surfactant‐treated females. Female moth exposure to methoxyfenozide did not negatively impact the sensitivity of female antennae to the plant volatile pear ester, but it did towards the apple volatile butyl hexanoate. Data from this study show that adult C. pomonella exposure to methoxyfenozide‐treated surfaces does appear to negatively impact, in a minor way, the (i) olfactory sensitivity (or detection) of male antennae towards some components of the female sex pheromone, (ii) the female antennal sensitivity towards a key apple volatile and (iii) the attractiveness of female pheromone effluvia.
Imbalance of interleukin‐17‐producing CD4 T cells/regulatory T cells axis occurs in remission stage of patients with hepatitis B virus‐related acute‐on‐chronic liver failure
Authors: Zhang Geng‐Lin , Xie Dong‐Ying , Lin Bing‐Liang , Xie Chan , Ye Yi‐Nong , Peng Liang , Zhang Shao‐Quan , Zhang Yu‐Feng , Lai Qing , Zhu Jian‐Yun , Zhang Ying , Huang Yang‐Su , Hu Zhao‐Xia , Gao Zhi‐Liang
Published: December 2012

Background and Aim

Although regulatory T cells (Treg) and interleukin‐17‐producing CD4 T cells (Th17) have been demonstrated to play opposing roles in inflammation‐associated diseases, their frequency and balance in different stages of hepatitis B virus (HBV)‐related acute‐on‐chronic liver failure (ACLF) remain unknown.

Methods

Fourteen patients with HBV‐associated ACLF were studied and defined into different stages according to disease activity. Circulating Th17 cells and Treg cells were analyzed by flow cytometry, and the cytokines were quantitated by enzyme‐linked immunosorbent assay. Results were correlated with temporal changes in viral load, disease progression and compared with 30 chronic hepatitis B (CHB) subjects and 18 healthy subjects.

Results

We showed a significantly higher frequency of circulating Th17 cells in the remission stage of ACLF when compared with the progression stage, the CHB group, or normal controls. However, the frequency of circulating Treg cells was significantly lower in the remission stage of ACLF when compared with the progression stage or the CHB group. The increase in Th17 cells and concomitant decrease in Treg cells created an imbalance in the remission stage of ACLF patients, which negatively correlated with disease progression. In addition, we showed that ACLF patients in the remission stage had an altered profile of cytokines that regulated the induction of Th17 cells and Treg cells.

Conclusions

ACLF patients in the remission stage had an imbalance of Th17 to Treg cells, which could be used as a prognostic marker to predict disease progression. This imbalance could play a role in the immunopathogenesis of HBV‐related ACLF.
Stereotactic body radiation therapy combined with transcatheter arterial chemoembolization for small hepatocellular carcinoma
Authors: Honda Yohji , Kimura Tomoki , Aikata Hiroshi , Kobayashi Tomoki , Fukuhara Takayuki , Masaki Keiichi , Nakahara Takashi , Naeshiro Noriaki , Ono Atsushi , Miyaki Daisuke , Nagaoki Yuko , Kawaoka Tomokazu , Takaki Shintaro , Hiramatsu Akira , Ishikawa Masaki , Kakizawa Hideaki , Kenjo Masahiro , Takahashi Shoichi , Awai Kazuo , Nagata Yasushi , Chayama Kazuaki
Published: December 2012

Abstact

Background and Aims

To compare the tumor control and safety of stereotactic body radiation therapy (SBRT) combined with transcatheter arterial chemoembolization (TACE) for small, solitary, and hypervascular hepatocellular carcinoma (HCC) with TACE alone.

Methods

Three hundred and sixty‐five HCC patients who had solitary, ≤ 3 cm, and hypervascular nodule were treated with TACE. Among them, 30 patients followed by SBRT (SBRT group) and 38 patients without additional therapy and previous HCC treatment (control group) were enrolled in this retrospective cohort study. Local tumor progression, complication, and disease‐free survival were compared between these groups.

Results

There was no difference in clinical background between these groups. Complete response to therapy was noted in 29 (96.3%) patients of the SBRT group, and in only one (3.3%) patient of the TACE group (P < 0.001). None of the patients developed acute hematologic toxicity of more than Common Terminology Criteria for Adverse Events Grade 3 during and after the treatment. Furthermore, none of the SBRT group developed radiation‐induced liver damage. Disease‐free survival of the 12 patients without previous HCC treatments in SBRT group was significantly superior to that in control group (15.7 months vs 4.2 months; P = 0.029).

Conclusion

The results indicated that SBRT combined with TACE is a safe and effective modality for locoregional treatment of small solitary primary HCC, and could be potentially a suitable option.
Single nucleotide polymorphism rs3732860 in the 3′‐untranslated region of CYP8B1 gene is associated with gallstone disease in Han Chinese
Authors: Qin Jian , Han Tian‐Quan , Yuan Wen‐Tao , Zhang Jing , Fei Jian , Jiang Zhao‐Yan , Niu Zhen‐Min , Zhang Kai‐Yue , Hua Qi , Cai Xing‐Xing , Xu Shi‐Jie , Huang Wei , Zhang Sheng‐Dao
Published: December 2012

Background and Aims

Gallstone disease (GD) is a common disease of multigenetic origin; however, the major susceptibility loci for GD in human populations remain unidentified. This study aimed to identify the genetic factors contributing to gallstone development in Chinese.

Methods

A genome‐wide scan was conducted in 12 Han Chinese GD families to identify linkage loci. The linkage region showing the highest logarithm of odds score encompasses the sterol 12α‐hydroxylase gene (CYP8B1). Replication analysis with an independent sample of 192 GD patients and 192 unrelated, matched controls was carried out to verify the associations between CYP8B1 polymorphisms and GD.

Results

Three loci (D3S1266, D4S406, and D9S1682) showed suggestive or nominal evidence of linkage in all 12 GD families. The logarithm of odds score of D3S1266 reached 2.71 in the families with late‐onset patients. The single nucleotide polymorphism rs3732860 in the 3′‐untranslated region of CYP8B1 showed significant association to GD (P = 0.022), and carriers of the A allele had lower risk of GD (odds ratio = 1.46, 95% confidence interval: 1.055–2.034) compared with carriers of the G allele.

Conclusions

The single nucleotide polymorphism rs3732860 in the 3′‐untranslated region of the CYP8B1 gene is associated with risk of GD in Chinese Han and appears to be responsible for the observed linkage with D3S1266.
Lexicon for the Sensory Description of Australian Native Plant Foods and Ingredients
Authors: Smyth H.E. , Sanderson J.E. , Sultanbawa Y.
Published: December 2012

Understanding and describing “Australian flavor” has proved to be a challenge for marketers of native foods because of the diversity of unique flavor signatures exhibited. Descriptive analysis techniques were applied, using a panel of 11 experienced judges, to define and articulate the sensory properties of 18 key commercial Australian native plant foods and ingredients including fruits, herbs and spices. Quantitative descriptive data were transformed into concise and accurate verbal descriptions for each of the species. The sensory language developed during the vocabulary development panel sessions was combined, categorized and ordered to develop a sensory lexicon specific for the genre. The language developed to describe the foods and ingredients was diverse and distinctly Australian including aromas such as musk, rosella, citrus and spiced tea to eucalypt, bush scrub, fresh beetroot and wheat biscuit.

Practical Applications

This work provides a clear, useful means of characterizing and accurately describing the flavors of Australian native plant foods and ingredients. This information has been communicated to the native food industry, chefs, formulators, food technologists and flavor experts, and provides knowledge that will assist the wider food industry to successfully develop flavor blends and produce food products from native food ingredients. It is anticipated that extension of this information to both the local and international food markets will stimulate a renewed interest in Australian native ingredients and open new market opportunities for the industry. The data developed by this research have also formed the basis of quality control targets for emerging native foods and ingredients.
CUSUM‐type testing for changing parameters in a spatial autoregressive model for stock returns
Authors: Wied Dominik
Published: December 2012

The article suggests a CUSUM‐type test for time‐varying parameters in a recently proposed spatial autoregressive model for stock returns and derives its asymptotic null distribution as well as local power properties. As can be seen from Euro Stoxx 50 returns, a combination of spatial modelling and change point tests might allow for superior risk forecasts in portfolio management.
A fresh view of the cell biology of copper in enterobacteria
Authors: Nies Dietrich H. , Herzberg Martin
Published: December 2012

Copper ions are essential but also very toxic. Copper resistance in bacteria is based on export of the toxic ion, oxidation fromCu(I)toCu(II), and sequestration by copper‐binding metal chaperones, which deliver copper ions to efflux systems or metal‐binding sites of copper‐requiring proteins. In their publication in this issue,Osmanet al. () demonstrate how tightly copper resistance, homeostasis and delivery pathways are interwoven inSalmonella entericasv.Typhimurium. Copper is transported from the cytoplasm by the twoP‐typeATPasesCopAandGolTto the periplasm and transferred toSodCIIbyCueP, a periplasmic copper chaperone. When copper levels are higher,SodCIIis also able to bind copper without the help ofCueP. This scheme raises the question as to why copper ions present in the growth medium have to make the detour through the cytoplasm. The data presented in the publication byOsmanet al. () change our view of the cell biology of copper in enterobacteria.
Smad7 gene transfer attenuates angiogenesis in peritoneal dialysis rats
Authors: Peng Weisheng , Dou Xianrui , Hao Wenke , Zhou Qiaoling , Tang Rong , Nie Jing , Lan Hui Y , Yu Xueqing
Published: December 2012

This is an animal study that demonstrated reduced peritoneal angiogenesis through the blockade of transforming growth factor‐β, through signalling with Smad7. This presents a novel therapeutic approach to decrease ultrafiltration failure and hence increase peritoneal dialysis technique longevity.
Systematic review and meta‐analysis of mesenchymal stem/stromal cells therapy for impaired renal function in small animal models
Authors: Wang Yan , He Juan , Pei Xiaohua , Zhao Weihong
Published: December 2012

Aim

The meta‐analysis of recent small animal experiments of mesenchymal stem/stromal cells (MSC) therapy for impaired kidney could provide significant clues to design large animal experiments as well as human clinical trials.

Method

A total of 21 studies was analyzed. These, were indexed from PubMed and Embase databases. All data were analyzed by RevMan 5.1 and SPSS 17.0. Pooled analysis and multivariable meta‐regression were calculated by random effects models. Heterogeneity and publication bias across the studies were also explored.

Results

Pooled analysis showed elevated serum creatinine (Scr) reduction in the animal models of renal failure following MSC therapy. By exploratory multivariable meta‐regression, significant influence factors of Scr reduction were the time point of Scr measurement (early measurement showed greater reduction than the late (P = 0.005)) and the route of MSC delivery (arterial delivery of MSCs caused greater reduction in elevated Scr, when compared with the intra‐renal delivery and intravenous injection (P = 0.040)). Subgroup analysis showed there tended to be greater reduction in Scr with higher MSC number (>106), the renal ischemia‐reperfusion injury (IRI) model, and late administration (>1 day) after injury.

Conclusion

The present meta‐analysis confirmed that MSC therapy could improve impaired renal function. MSCs might get obvious effect in the early stage of renal injuries after arterial delivery. Further, this meta‐analysis may provide important clues for animal experiments even for human clinical trials in MSC studies.
Efficient marker‐assisted backcross conversion of seed‐parent lines to cytoplasmic male sterility
Authors: Herzog Eva , Frisch Matthias
Published: December 2012

For many crops, cytoplasmic male sterility (CMS) is a cornerstone of hybrid production. Efficient conversion of elite lines to CMS by marker‐assisted backcrossing is therefore desirable. In contrast to gene introgression, for which donor segments around target genes have to be considered, background selection for CMS conversion focuses solely on recovery of the recurrent parent genome. The optimal selection strategies for CMS conversion will consequently differ from those for gene introgression and have not yet been investigated. The objectives of our study were to evaluate and optimize the resource requirements of CMS conversion programmes and to determine the most cost‐effective use of single‐marker (SM) and high‐throughput (HT) assays for this purpose. We conducted computer simulations for CMS conversion of genetic models of sugar beet, rye, sunflower and rapeseed. CMS conversion required fewer resources than gene introgression with respect to population size, marker data points and number of backcross generations. Combining HT assays in early backcross generations with SM assays in advanced backcross generations further increased the cost‐efficiency of CMS conversion for a broad range of cost ratios.
Single rRNA Helices Bind Independently to the Protein‐Conducting Channel SecYEG
Authors: Behrens Christina , Hartmann Enno , Kalies Kai‐Uwe
Published: December 2012

Ribosomes tightly interact with protein‐conducting channels in the plasma membrane of bacteria (SecYEG) and in the endoplasmic reticulum of eukaryotes (Sec61 complex). This interaction is mediated by multiple junctions and is highly conserved during evolution. Although it is well known that both ribosomal proteins and ribosomal RNA (rRNA) are involved in the ribosome–channel interaction, detailed analyses on how these components contribute to this binding are lacking. Here, we demonstrate that the evolutionary conservation of ribosome binding is solely mediated by rRNA. Moreover, we show that in vitro transcribed 23 S rRNA binds with similar characteristics to protein translocation channels as native 23 S rRNA or 50 S ribosomal subunits. This indicates that base modifications, which exist in native rRNA, do not crucially influence the binding. In two of the ribosome‐channel junctions (c1 and c2), exclusively rRNA helices are involved. Using in vitro transcribed rRNA mutants, we now provide evidence that large parts of the rRNA can be deleted without altering its binding properties, as long as the rRNA helices of the c1 and c2 junctions remain intact. We demonstrate that the connection sites c1 and c2 generate high‐affinity binding sites that act independently of each other. This could explain why membrane‐bound ribosomes have an extremely low off‐rate.
Analyzing actual risk in malaria‐deferred donors through selective serologic testing
Authors: Nguyen Megan L. , Goff Tami , Gibble Joan , Steele Whitney R. , Leiby David A.
Published: December 2012

Background

Approximately 150,000 US blood donors are deferred annually for travel to malaria‐endemic areas. However, the majority do not travel to the high‐risk areas of Africa associated with transfusion‐transmitted malaria (TTM) but visit low‐risk areas such as Mexico. This study tests for Plasmodium infection among malaria‐deferred donors, particularly those visiting Mexico.

Study Design and Methods

Blood donors deferred for malaria risk (travel, residence, or previous infection) provided blood samples and completed a questionnaire. Plasma was tested for Plasmodium antibodies by enzyme immunoassay (EIA); repeat‐reactive (RR) samples were considered positive and tested by real‐time polymerase chain reaction (PCR). Accepted donors provided background testing data.

Results

During 2005 to 2011, a total of 5610 malaria‐deferred donors were tested by EIA, including 5412 travel deferrals. Overall, 88 (1.6%) were EIA RR; none were PCR positive. Forty‐nine (55.7%) RR donors previously had malaria irrespective of deferral category, including 34 deferred for travel. Among 1121 travelers to Mexico, 90% visited Quintana Roo (no or very low risk), but just 2.2% visited Oaxaca/Chiapas (moderate or high risk). Only two Mexican travelers tested RR; both previously had malaria not acquired in Mexico.

Conclusions

Travel to Mexico represents a large percentage of US donors deferred for malaria risk; however, these donors primarily visit no‐ or very‐low‐risk areas. No malaria cases acquired in Mexico were identified thereby supporting previous risk estimates. Consideration should be given to allowing blood donations from US donors who travel to Quintana Roo and other low‐risk areas in Mexico. A more effective approach to preventing TTM would be to defer all donors with a history of malaria, even if remote.
The tangent complex and Hochschild cohomology of -rings
Authors: Francis John
Published: December 2012

In this work, we study the deformation theory of${\mathcal {E}}_n$-rings and the${\mathcal {E}}_n$analogue of the tangent complex, or topological André–Quillen cohomology. We prove a generalization of a conjecture of Kontsevich, that there is a fiber sequence$A[n-1] \rightarrow T_A\rightarrow {\mathrm {HH}}^*_{{\mathcal {E}}_{n}}\!(A)[n]$, relating the${\mathcal {E}}_n$-tangent complex and${\mathcal {E}}_n$-Hochschild cohomology of an${\mathcal {E}}_n$-ring$A$. We give two proofs: the first is direct, reducing the problem to certain stable splittings of configuration spaces of punctured Euclidean spaces; the second is more conceptual, where we identify the sequence as the Lie algebras of a fiber sequence of derived algebraic groups,$B^{n-1}A^\times \rightarrow {\mathrm {Aut}}_A\rightarrow {\mathrm {Aut}}_{{\mathfrak B}^n\!A}$. Here${\mathfrak B}^n\!A$is an enriched$(\infty ,n)$-category constructed from$A$, and${\mathcal {E}}_n$-Hochschild cohomology is realized as the infinitesimal automorphisms of${\mathfrak B}^n\!A$. These groups are associated to moduli problems in${\mathcal {E}}_{n+1}$-geometry, a less commutative form of derived algebraic geometry, in the sense of the work of Toën and Vezzosi and the work of Lurie. Applying techniques of Koszul duality, this sequence consequently attains a nonunital${\mathcal {E}}_{n+1}$-algebra structure; in particular, the shifted tangent complex$T_A[-n]$is a nonunital${\mathcal {E}}_{n+1}$-algebra. The${\mathcal {E}}_{n+1}$-algebra structure of this sequence extends the previously known${\mathcal {E}}_{n+1}$-algebra structure on${\mathrm {HH}}^*_{{\mathcal {E}}_{n}}\!(A)$, given in the higher Deligne conjecture. In order to establish this moduli-theoretic interpretation, we make extensive use of factorization homology, a homology theory for framed$n$-manifolds with coefficients given by${\mathcal {E}}_n$-algebras, constructed as a topological analogue of Beilinson and Drinfeld’s chiral homology. We give a separate exposition of this theory, developing the necessary results used in our proofs.
Bases for cluster algebras from surfaces
Authors: Musiker Gregg , Schiffler Ralf , Williams Lauren
Published: December 2012

We construct two bases for each cluster algebra coming from a triangulated surface without punctures. We work in the context of a coefficient system coming from a full-rank exchange matrix, such asprincipal coefficients.
Low-temperature (≤200 °C) plasma enhanced atomic layer deposition of dense titanium nitride thin films
Authors: Samal Nigamananda , Du Hui , Luberoff Russell , Chetry Krishna , Bubber Randhir , Hayes Alan , Devasahayam Adrian
Published: December 2012

Titanium nitride (TiN) has been widely used in the semiconductor industry for its diffusion barrier and seed layer properties. However, it has seen limited adoption in other industries in which low temperature (<200 °C) deposition is a requirement. Examples of applications which require low temperature deposition are seed layers for magnetic materials in the data storage (DS) industry and seed and diffusion barrier layers for through-silicon-vias (TSV) in the MEMS industry. This paper describes a low temperature TiN process with appropriate electrical, chemical, and structural properties based on plasma enhanced atomic layer deposition method that is suitable for the DS and MEMS industries. It uses tetrakis-(dimethylamino)-titanium as an organometallic precursor and hydrogen (H2) as co-reactant. This process was developed in a Veeco NEXUS™ chemical vapor deposition tool. The tool uses a substrate rf-biased configuration with a grounded gas shower head. In this paper, the complimentary and self-limiting character of this process is demonstrated. The effects of key processing parameters including temperature, pulse time, and plasma power are investigated in terms of growth rate, stress, crystal morphology, chemical, electrical, and optical properties. Stoichiometric thin films with growth rates of 0.4–0.5 Å/cycle were achieved. Low electrical resistivity (<300 μΩ cm), high mass density (>4 g/cm3), low stress (<250 MPa), and >85% step coverage for aspect ratio of 10:1 were realized. Wet chemical etch data show robust chemical stability of the film. The properties of the film have been optimized to satisfy industrial viability as a Ruthenium (Ru) preseed liner in potential data storage and TSV applications.
Microplasma enhancement via the formation of a graphite-like phase on diamond cathodes
Authors: Chen Huang-Chin , Lin I-Nan , Lou Shiu-Cheng , Chen Chulung , Tang Ray-Her , Shih Wen-Ching , Lo Shen-Chuan , Lin Li-Jen , Lee Chi-Young
Published: December 2012

Enhanced electron field emission (EFE) properties in microcrystalline diamond (MCD) films that have been Fe-coated and postannealed are observed. Additionally, improved microplasma characteristics are also observed when these materials are used as cathodes. The turn-on field for inducing the EFE process decreases from 4.7 V/μm for pristine MCD films to 2.2 V/μm for the Fe-coated/postannealed ones, whereas the EFE current density at an applied field of 8.8 V/μm increases from 36.5 to 5327.1 μA/cm2. Transmission electron microscopy, in conjunction with high-angle annular dark field and 3D-tomography studies, reveals that enhanced EFE in the Fe-coated/postannealed MCD films is due to the graphite-like phase on the surface of diamond films. The authors infer that the Fe-coating interacts with the diamond in the postannealing process to dissolve carbons and reprecipitate them in nanographite networks. This process is similar to the formation of carbon nanotubes by the dissolution and reprecipitation of carbon species at the presence of nanosized Fe catalysts. The utilization of high EFE diamond films as cathode materials enhances the microplasma, as the ignition field for initiating the plasma is lowered and a high plasma current density is attainable.
Atomic layer deposition of zinc sulfide with Zn(TMHD)2
Authors: Short Andrew , Jewell Leila , Doshay Sage , Church Carena , Keiber Trevor , Bridges Frank , Carter Sue , Alers Glenn
Published: December 2012

The atomic layer deposition (ALD) of ZnS films with Zn(TMHD)2 and in situ generated H2S as precursors was investigated, over a temperature range of 150–375 °C. ALD behavior was confirmed by investigation of growth behavior and saturation curves. The properties of the films were studied with atomic force microscopy, scanning electron microscopy, energy-dispersive x-ray spectroscopy, ultraviolet–visible–infrared spectroscopy, and extended x-ray absorption fine structure. The results demonstrate a film that can penetrate a porous matrix, with a local Zn structure of bulk ZnS, and a band gap between 3.5 and 3.6 eV. The ZnS film was used as a buffer layer in nanostructured PbS quantum dot solar cell devices.
Characterization of HfO2/La2O3 layered stacking deposited on Si substrate
Authors: Cao Duo , Cheng Xinhong , Jia Tingting , Xu Dawei , Wang Zhongjian , Xia Chao , Yu Yuehui , Shen DaShen
Published: December 2012

Two-layer and four-layer HfO2/La2O3 stacked structures were grown on a Si substrate by plasma enhanced atomic layer deposition at 200 °C. High resolution transmission electron microscopy results indicated that both films were amorphous with no crystals. Based on atomic force microscopy, the roughness of both films was 0.1 nm. X-ray photoelectron spectroscopy spectra indicated that the interfacial layer of the films was most likely composed of Hf-Si-O and La-Si-O. At a gate bias of |Vg − Vfb| = 1 V, the leakage current densities of the two-layer and four-layer films were 0.02 and 0.01 mA/cm2, respectively. The equivalent oxide thicknesses of the stacked structures were 1.2 and 1.5 nm, respectively. The density of interfacial states between dielectric and substrate was calculated to be 1.71 × 1012 and 1.32 × 1012 eV−1cm−2 for the two- and four-layer films, respectively.
Hybrid noise control in a duct using a light micro-perforated plate
Authors: Wang X. N. , Choy Y. S. , Cheng L.
Published: December 2012

A plate silencer consists of an expansion chamber with two side-branch cavities covered by light but extremely stiff plates. It works effectively with a wide stopband from low-to-medium frequencies only if the plate is extremely stiff, to ensure a strong reflection of acoustic wave to the upstream in the duct. However, a plate with a slightly weak bending stiffness will result in non-uniform transmission loss (TL) spectra with narrowed stopband. In this study, a hybrid silencer is proposed by introducing micro-perforations into the plate to elicit the sound absorption in order to compensate for the deficiency in the passband caused by the insufficient sound reflection in a certain frequency range due to weaker plate stiffness. A theoretical model, capable of dealing with the strong coupling between the vibrating micro-perforated plate and sound fields inside the cavity and the duct, is developed. Through proper balancing between the sound absorption and reflection, the proposed hybrid silencer provides a more flattened and uniform TL and a widened stopband by more than 20% while relaxing the harsh requirement on the bending stiffness of the plate. Theoretical predictions are validated by experimental data, with phenomenon explained through numerical analyses.
Large scale modulation of high frequency acoustic waves in periodic porous media
Authors: Boutin Claude , Rallu Antoine , Hans Stephane
Published: December 2012

This paper deals with the description of the modulation at large scale of high frequency acoustic waves in gas saturated periodic porous media. High frequencies mean local dynamics at the pore scale and therefore absence of scale separation in the usual sense of homogenization. However, although the pressure is spatially varying in the pores (according to periodic eigenmodes), the mode amplitude can present a large scale modulation, thereby introducing another type of scale separation to which the asymptotic multi-scale procedure applies. The approach is first presented on a periodic network of inter-connected Helmholtz resonators. The equations governing the modulations carried by periodic eigenmodes, at frequencies close to their eigenfrequency, are derived. The number of cells on which the carrying periodic mode is defined is therefore a parameter of the modeling. In a second part, the asymptotic approach is developed for periodic porous media saturated by a perfect gas. Using the “multicells” periodic condition, one obtains the family of equations governing the amplitude modulation at large scale of high frequency waves. The significant difference between modulations of simple and multiple mode are evidenced and discussed. The features of the modulation (anisotropy, width of frequency band) are also analyzed.
Propagation of natural toad calls in a Mediterranean terrestrial environment
Authors: Penna Mario , Llusia Diego , Márquez R.
Published: December 2012

Propagation patterns of animal acoustic signals provide insights into the evolution of signal design to convey signaler's information to potential recipients. However, propagation properties of vertebrate calls have been rarely studied using natural calls from individuals; instead playback calls broadcast through loudspeakers have been used extensively, a procedure that may involve acoustical and physical features differing from natural sounds. Measurements of the transmission characteristics of natural advertisement calls, which are simple tonal sounds, of the Iberian midwife toad, Alytes cisternasii, were carried out, and the results were compared with previously published results broadcasting recorded calls of the same species. Measurements of sound pressure level (SPL) of calls from individual male A. cisternasii revealed that the call amplitude decreases at distances of 1–8 m from the source at rates averaging 1–5 dB above spherical transmission loss in an omni-directional pattern. A comparison between SPLs of natural calls in the current study and of playback calls from a previous study showed that patterns of propagation did not differ in average values, but variance was significantly higher for natural calls. Results suggest that using broadcast signals for transmission experiments may result in a simplification of the conditions in which actual animals communicate in nature.
Single-carrier frequency-domain turbo equalization without cyclic prefix or zero padding for underwater acoustic communications
Authors: Wang Longbao , Tao Jun , Zheng Yahong Rosa
Published: December 2012

A frequency-domain turbo equalization (FDTE) scheme without cyclic prefix (CP) or zero padding is proposed for single-carrier, multiple-input-multiple-output underwater acoustic communication. In the first iteration of the FDTE, the received continuous data stream is divided into consecutive blocks and a combined inter-block-interference (IBI) cancellation and overlapped windowing scheme is used to diagonalize each data block for low-complexity detection in the frequency domain. Since the second iteration, IBI cancellation and CP reconstruction are applied on each block to enable effective symbol detection. This work extends the authors' previous work on frequency-domain hard-decision equalization to soft-decision turbo equalization so that it not only retains high data transmission efficiency, but also improves the bit error rate performance with slightly increased complexity due to multiple iterations. Its feasibility and effectiveness have been tested by field trial data from the ACOMM09 underwater communication experiment.
Nonlinear time-domain cochlear model for transient stimulation and human otoacoustic emission
Authors: Verhulst Sarah , Dau Torsten , Shera Christopher A.
Published: December 2012

This paper describes the implementation and performance of a nonlinear time-domain model of the cochlea for transient stimulation and human otoacoustic emission generation. The nonlinearity simulates compressive growth of measured basilar-membrane impulse responses. The model accounts for reflection and distortion-source otoacoustic emissions (OAEs) and simulates spontaneous OAEs through manipulation of the middle-ear reflectance. The model was calibrated using human psychoacoustical and otoacoustic tuning parameters. It can be used to investigate time-dependent properties of cochlear mechanics and the generator mechanisms of otoacoustic emissions. Furthermore, the model provides a suitable preprocessor for human auditory perception models where realistic cochlear excitation patterns are desired.
Perception of missing fundamental pitch by 3- and 4-month-old human infants
Authors: Lau Bonnie K. , Werner Lynne A.
Published: December 2012

A hallmark of complex pitch perception is that the pitch of a harmonic complex is the same whether or not the fundamental frequency is present. By 7 months, infants appear to discriminate on the basis of the pitch of the missing fundamental (MF). Although electrophysiological cortical responses to MF pitch changes have been recorded in infants younger than 7 months, no psychophysical studies have been published. This study investigated the ability of 3- and 4-month-olds to perceive the pitch of MF harmonic complexes based on fundamentals of 160 Hz and 200 Hz using an observer-based method. In experiment I, to demonstrate MF pitch discrimination, 3- and 4-month-olds were required to ignore spectral changes in complexes with the same fundamental and to respond only when the fundamental changed. In experiment II, a 60–260 Hz noise was presented with complexes to mask combination tones at the fundamental frequency. In experiment III, complexes were bandpass filtered with a −12 dB/octave slope to limit use of spectral edge cues and presented with a pink noise to mask all distortion products. Nearly all infants tested categorized complexes by MF pitch in these experiments, suggesting perception of the missing fundamental at 3 months.
Theoretical microbubble dynamics in a viscoelastic medium at capillary breaching thresholds
Authors: Patterson Brandon , Miller Douglas L. , Johnsen Eric
Published: December 2012

In order to predict bioeffects in contrast-enhanced diagnostic and therapeutic ultrasound procedures, the dynamics of cavitation microbubbles in viscoelastic media must be determined. For this theoretical study, measured 1.5 to 7.5 MHz pulse pressure waveforms, which were used in experimental determinations of capillary breaching thresholds for contrast-enhanced diagnostic ultrasound in a rat kidney, were used to calculate cavitation nucleated from contrast agent microbubbles. A numerical model for cavitation in tissue was developed based on the Keller-Miksis equation (a compressible extension of the Rayleigh-Plesset equation for spherical bubble dynamics), with a Kelvin-Voigt constitutive relation. From this model, the bubble dynamics corresponding to the experimentally obtained capillary breaching thresholds were determined. Values of the maximum radius and temperature corresponding to previously determined bioeffect thresholds were computed for a range of ultrasound pulses and bubble sizes for comparison to inertial cavitation threshold criteria. The results were dependent on frequency, the gas contents, and the tissue elastic properties. The bioeffects thresholds were above previously determined inertial cavitation thresholds, even for the tissue models, suggesting the possibility of a more complex dosimetry for capillary injury in tissue.
Acoustic identification of buried underwater unexploded ordnance using a numerically trained classifier (L)
Authors: Bucaro Joseph A. , Waters Zachary J. , Houston Brian H. , Simpson Harry J. , Sarkissian Angie , Dey Saikat , Yoder Timothy J.
Published: December 2012

Using a finite element-based structural acoustics code, simulations were carried out for the acoustic scattering from an unexploded ordnance rocket buried in the sediment under 3 m of water. The simulation treated 90 rocket burial angles in steps of 2°. The simulations were used to train a generative relevance vector machine (RVM) algorithm for identifying rockets buried at unknown angles in an actual water/sediment environment. The trained RVM algorithm was successfully tested on scattering measurements made in a sediment pool facility for six buried targets including the rocket at 90°, 120°, and 150°, a boulder, a cinderblock, and a cinderblock rolled 45° about its long axis.
Assessing the role of spectral and intensity cues in spectral ripple detection and discrimination in cochlear-implant users
Authors: Anderson Elizabeth S. , Oxenham Andrew J. , Nelson Peggy B. , Nelson David A.
Published: December 2012

Measures of spectral ripple resolution have become widely used psychophysical tools for assessing spectral resolution in cochlear-implant (CI) listeners. The objective of this study was to compare spectral ripple discrimination and detection in the same group of CI listeners. Ripple detection thresholds were measured over a range of ripple frequencies and were compared to spectral ripple discrimination thresholds previously obtained from the same CI listeners. The data showed that performance on the two measures was correlated, but that individual subjects’ thresholds (at a constant spectral modulation depth) for the two tasks were not equivalent. In addition, spectral ripple detection was often found to be possible at higher rates than expected based on the available spectral cues, making it likely that temporal-envelope cues played a role at higher ripple rates. Finally, spectral ripple detection thresholds were compared to previously obtained speech-perception measures. Results confirmed earlier reports of a robust relationship between detection of widely spaced ripples and measures of speech recognition. In contrast, intensity difference limens for broadband noise did not correlate with spectral ripple detection measures, suggesting a dissociation between the ability to detect small changes in intensity across frequency and across time.