bluuebunny/crossref_metadata_2025 huggingface dataset:
Multiple antigen peptide mimetics containing gp41 membrane‐proximal external region elicit broad neutralizing antibodies against human immunodeficiency virus type 1 in guinea pigs
Authors: Zhang Lishuang , Miao Liang , Gong Xin , Zhang Huayan , Yang Lan , Shi Yuhua , Kong Wei , Jiang Chunlai , Shan Yaming
Published: June 2013

Eliciting a broadly neutralizing antibody response against the HIV‐1 membrane‐proximal external region (MPER) mimicking the activity of 4E10 and 2F5 monoclonal antibodies remains a major challenge. In this study, two novel tetra‐branched peptide immunogens, 4E10‐ and 2F5‐MAP4, were designed and synthesized using a MAP system. Guinea pigs were immunized with either of these two synthetic immunogens emulsified in an oil‐phase adjuvant at 3‐week intervals. After four immunizations, epitope‐specific antibody responses were induced successfully, and moderate neutralizing activities against tier 1 (clades B, BC, AE) and tier 2 (clade C) HIV‐1 pseudoviruses were detectable in unfractionated sera and purified IgGs. The synthetic gp41 membrane‐proximal external region peptide mimetics, 4E10‐ and 2F5‐MAP4, assisted by an appropriate adjuvant, are promising prophylactic vaccine candidates potentially capable of eliciting broadly neutralizing antibody responses against HIV‐1. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.
Molecular dynamics simulations of certain mutant peptide models from staphylococcal nuclease reveal that initial hydrophobic collapse associated with turn propensity drives β‐hairpin folding
Authors: Shukla Rashmi Tambe , Kumar Naveen , Sasidhar Yellamraju U.
Published: June 2013

An important nucleation event during the folding of staphylococcal nuclease involves the formation of a β‐hairpin by the sequence 21DTVKLMYKGQPMTFR35. Earlier studies show that the turn sequence ‘YKGQP’ has an important role in the folding of this β‐hairpin. To understand the active or passive nature of the turn sequence ‘YKGQP’ in the folding of the aforementioned β‐hairpin sequence, we studied glycine mutant peptides Ac‐2DTVKLMYGGQPMTFR16‐NMe (K9G:15), Ac‐2DTVKLMYKGGPMTFR16‐NMe (Q11G:15), Ac‐2DTVKLMYGGGPMTFR16‐NMe (K9G/Q11G:15), and Ac‐2DTVKLMGGGGGMTFR16‐NMe (penta‐G:15) by using molecular dynamics simulations, starting with two different unfolded states, polyproline II and extended conformational forms. Further, 5mer mutant turn peptides Ac‐2YGGQP6‐NMe (K3G:5), Ac‐2YKGGP6‐NMe (Q5G:5), Ac‐2YGGGP6‐NMe (K3G/Q5G:5), and Ac‐2GGGGG6‐NMe (penta‐G:5) were also studied individually. Our results show that an initial hydrophobic collapse and loop closure occurs in all 15mer mutants, but only K9G:15 mutant forms a stable native‐like β‐hairpin. In the other 15mer mutants, the hydrophobic collapsed state would not proceed to β‐hairpin formation. Of the different simulations performed for the penta‐G:15 mutant, in only one simulation a nonnative β‐hairpin conformation is sampled with highly flexible loop region (8GGGGG12), which has no specific conformational preference as a 5mer. While the sequence ‘YGGQP’ in the K3G:5 simulation shows relatively higher β‐turn propensity, the presence of this sequence in K9G:15 peptide seems to be driving the β‐hairpin formation. Thus, these results seem to suggest that for the formation of a stable β‐hairpin, the initial hydrophobic collapse is to be assisted by a turn propensity. Initial hydrophobic collapse alone is not sufficient to guide β‐hairpin formation. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.
Uniqueness of solutions for moist advection problems
Authors: Temam Roger , Tribbia Joseph
Published: June 2013

This article presents, for physics‐oriented readers, some recent mathematical results that establish the uniqueness of solutions for moist advection problems in climate models. The presentation is made for a simplified model, which is nevertheless typical and significant.
Assessing heterogeneity of treatment effect in a clinical trial with the proportional interactions model
Authors: Kovalchik Stephanie A. , Varadhan Ravi , Weiss Carlos O.
Published: June 2013

Understanding how individuals vary in their response to treatment is an important task of clinical research. For standard regression models, a proportional interactions model first described by Follmann and Proschan (1999) offers a powerful approach for identifying effect modification in a randomized clinical trial when multiple variables influence treatment response. In this paper, we present a framework for using the proportional interactions model in the context of a parallel‐arm clinical trial with multiple prespecified candidate effect modifiers. To protect against model misspecification, we propose a selection strategy that considers all possible proportional interactions models. We develop a modified Bonferroni correction for multiple testing that accounts for the positive correlation among candidate models. We describe methods for constructing a confidence interval for the proportionality parameter. In simulation studies, we show that our modified Bonferroni adjustment controls familywise error and has greater power to detect proportional interactions compared with multiplcity‐corrected subgroup analyses. We demonstrate our methodology by using the Studies of Left Ventricular Dysfunction Treatment trial, a placebo‐controlled randomized clinical trial of the efficacy of enalapril to reduce the risk of death or hospitalization in chronic heart failure patients. An R package called anoint is available for implementing the proportional interactions methodology. Copyright © 2013 John Wiley & Sons, Ltd.
The frequency of CFVD speed report for highway traffic
Authors: Chang Ming‐Feng , Chen Chi‐Hua , Lin Yi‐Bing , Chia Chung‐Yung
Published: June 2013

The control signals of cellular networks have been used to infer the traffic conditions of the road network. In particular, consecutive handover events are being used to estimate the traffic speed. During traffic congestion, consecutive handover events may be rare because vehicles move slowly, and thus very few or no speed reports would be generated from the congested area.However, the traffic speed report rate during traffic congestion has not been investigated in the literature. In this paper, we present an analytic model to estimate the speed report rate from cellular network signaling in steady traffic conditions, that is, the traffic speed and flow are assumed constant. Real field trial data were used to validate our analytic model. In addition, computer simulations were conducted to study how speed reports are generated in dynamic traffic conditions when traffic speed and flow change rapidly. Our study indicates that in a typical cell of length 1.5 km with a typical expected call holding time of 1 min, no speed report was generated from a congested three‐lane highway. Our study demonstrates that the lack of speed reports from consecutive handover events during rush hours indicates severe traffic congestion, and new methods that can estimate traffic speed from cellular network data during severe traffic congestion need to be developed. Copyright © 2013 John Wiley & Sons, Ltd.
Exploiting the channel using uninterrupted collision‐free MAC adaptation over IEEE 802.11 WLANs
Authors: Tuysuz Mehmet F. , Mantar Haci A.
Published: June 2013

IEEE 802.11 wireless local area networks (WLANs) have reached an important stage and become a common technology for wireless access due to its low cost, ease of deployment, and mobility support. In parallel with the extensive growth of WLANs, the development of an efficient medium access control protocol that provides both high throughput performance for data traffic and quality of service support for real‐time applications has become a major focus in WLAN research. The IEEE 802.11 Distributed Coordination Functions (DCF/EDCA) provide contention‐based distributed channel access mechanisms for stations to share the wireless medium. However, performance of these mechanisms may drop dramatically because of high collision probabilities as the number of active stations increases. In this paper, we propose an adaptive collision‐free MAC adaptation. The proposed scheme prevents collisions and allows stations to enter the collision‐free state regardless of the traffic load (saturated or unsaturated) and the number of stations on the medium. Simulation results show that the proposed scheme dramatically enhances the overall throughput and supports quality of service for real‐time services over 802.11‐based WLANs. Copyright © 2013 John Wiley & Sons, Ltd.
Bioprocess development for nicotinic acid hydroxamate synthesis by acyltransferase activity of Bacillus smithii strain IITR6b2
Authors: Agarwal Shilpi , Gupta Meenu , Choudhury Bijan
Published: June 2013

In this work, acyltransferase activity of a new bacterial isolate Bacillus smithii strain IITR6b2 was utilized for the synthesis of nicotinic acid hydroxamate (NAH), a heterocyclic class of hydroxamic acid. NAH is an important pyridine derivative and has found its role as bioligand, urease inhibitor, antityrosinase, antioxidant, antimetastatic, and vasodilating agents. Amidase having acyltransferase activity with nicotinamide is suitable for nicotinic acid hydroxamate production. However, amidase can also simultaneously hydrolyze nicotinamide and nicotinic acid hydroxamate to nicotinic acid. Nicotinic acid is an undesirable by-product and thus any biocatalytic process involving amidase for nicotinic acid hydroxamate production needs to have high ratios of acyltransferase to amide hydrolase and acyltransferase to nicotinic acid hydroxamate hydrolase activity. Isolate Bacillus smithii strain IITR6b2 was found to have 28- and 12.3-fold higher acyltransferase to amide and hydroxamic acid hydrolase activities, respectively. This higher ratio resulted in a limited undesirable by-product, nicotinic acid (NA) synthesis. The optimal substrate/co-substrate ratio, pH, temperature, incubation time, and resting cells concentration were 200/250 mM, 7, 30 °C, 40 min, and 0.7 mgDCW ml−1, respectively, and 94.5 % molar conversion of nicotinamide to nicotinic acid hydroxamate was achieved under these reaction conditions. To avoid substrate inhibition effect, a fed-batch process based on the optimized parameters with two feedings of substrates (200/200 mM) at 40-min intervals was developed and a molar conversion yield of 89.4 % with the productivity of 52.9 g h−1 gDCW  −1 was achieved at laboratory scale. Finally, 6.4 g of powder containing 58.5 % (w/w) nicotinic acid hydroxamate was recovered after lyophilization and further purification resulted in 95 % pure product.
Cloning, production, and functional expression of the bacteriocin sakacin A (SakA) and two SakA-derived chimeras in lactic acid bacteria (LAB) and the yeasts Pichia pastoris and Kluyveromyces lactis
Authors: Jiménez Juan J , Borrero Juan , Diep Dzung B , Gútiez Loreto , Nes Ingolf F , Herranz Carmen , Cintas Luis M , Hernández Pablo E
Published: June 2013

Mature sakacin A (SakA, encoded by sapA) and its cognate immunity protein (SakI, encoded by sapiA), and two SakA-derived chimeras mimicking the N-terminal end of mature enterocin P (EntP/SakA) and mature enterocin A (EntA/SakA) together with SakI, were fused to different signal peptides (SP) and cloned into the protein expression vectors pNZ8048 and pMG36c for evaluation of their production and functional expression by different lactic acid bacteria. The amount, antimicrobial activity, and specific antimicrobial activity of SakA and its chimeras produced by Lactococcus lactis subsp. cremoris NZ9000 depended on the SP and the expression vector. Only L. lactis NZ9000 (pNUPS), producing EntP/SakA, showed higher bacteriocin production and antimicrobial activity than the natural SakA-producer Lactobacillus sakei Lb706. The lower antimicrobial activity of the SakA-producer L. lactis NZ9000 (pNUS) and that of the EntA/SakA-producer L. lactis NZ9000 (pNUAS) could be ascribed to secretion of truncated bacteriocins. On the other hand, of the Lb. sakei Lb706 cultures transformed with the pMG36c-derived vectors only Lb. sakei Lb706 (pGUS) overproducing SakA showed a higher antimicrobial activity than Lb. sakei Lb706. Finally, cloning of SakA and EntP/SakA into pPICZαA and pKLAC2 permitted the production of SakA and EntP/SakA by recombinant Pichia pastoris X-33 and Kluyveromyces lactis GG799 derivatives although their antimicrobial activity was lower than expected from their production.
Effects of a Genetic Counseling Model on Mothers of Children with Down Syndrome: A Brazilian Pilot Study
Authors: Micheletto Marcos Ricardo Datti , Valerio Nelson Iguimar , Fett‐Conte Agnes Cristina
Published: June 2013

Down syndrome occurs in approximately 1:600 live births. Genetic counseling is indicated for these families and may be beneficial for adaptation to the challenges that accompany by this diagnosis. Although the basic counseling goals are similar, there are many models of genetic counseling practiced around the world. The aim of this article is to report the results of a pilot study that evaluated the level of satisfaction with a model of service delivery of genetic counseling practiced in Brazil, the knowledge assimilated about Down syndrome and whether this process resulted in a feeling of well‐being and psychological support. Thirty mothers of under 6‐month‐old children with Down syndrome were interviewed after having two sessions of genetic counseling in a public healthcare service within a period of 30 days. A semi‐structured questionnaire was developed by the researchers to collect identification, socioeconomic and demographic data and to assess the client's satisfaction with the model of genetic counseling. Data were collected using both open and closed questions. The reported level of satisfaction was high. The knowledge assimilated about Down syndrome after only two sessions was considered technically vague by raters in 44 % of cases. Most mothers (96.7 %) reported that genetic counseling was beneficial and provided psychological support. The model was considered satisfactory, but further research is needed to identify ways to improve knowledge retention by this population. These results highlight the utility of referring families for genetic counseling when there is a suspicion of a diagnosis of Down syndrome.
Latent structure of posttraumatic stress disorder symptoms in an adolescent sample one month after an earthquake
Authors: Wang Richu , Wang Li , Li Zhongquan , Cao Chengqi , Shi Zhanbiao , Zhang Jianxin
Published: June 2013

Increasing empirical studies suggest that the tripartite posttraumatic stress disorder (PTSD) model described in the DSM‐IV does not accurately account for the underlying PTSD factor structure, and several alternative models have been proposed. The present study investigated a newly refined, five‐factor model of PTSD symptoms in a sample of Chinese adolescent survivors of an earthquake. A total of 1198 middle school students (653 females, 526 males) with a mean age of 14.4 years (SD = 1.1, range: 11–18) participated in this study one month after an earthquake. The novel five‐factor model comprised of intrusion, avoidance, numbing, dysphoric arousal, and anxious arousal demonstrated significantly better fit than two alternative four‐factor models. Further analyses revealed differentiable relations between the PTSD factors and external measures of anxiety and depression. These findings provide empirical support for the robustness of five‐factor model, and carry implications for further reorganization of PTSD criteria.
RNA self‐processing: Formation of cyclic species and concatemers from a small engineered RNA
Authors: Petkovic Sonja , Müller Sabine
Published: June 2013

We have engineered a self‐processing RNA, derived from the hairpin ribozyme that runs through a cascade of cleavage and ligation reactions thereby changing its topology. The first two cleavage events leave the resulting RNA with a 5′‐OH group and a 2′,3′‐cyclic phosphate. Thus, upon refolding, intramolecular ligation delivers a cyclic species. In addition, we demonstrate formation of concatemers resulting from multiple intermolecular ligations. Our results demonstrate the potential of RNA for self‐supported topology changes and support the suggestion of 2′,3′‐cyclic phosphates being suitable activated building blocks for reversible phosphodiester bond formation in the RNA world.
miR‐26a inhibits proliferation and motility in bladder cancer by targeting HMGA1
Authors: Lin Yiwei , Chen Hong , Hu Zhenghui , Mao Yeqing , Xu Xianglai , Zhu Yi , Xu Xin , Wu Jian , Li Shiqi , Mao Qiqi , Zheng Xiangyi , Xie Liping
Published: June 2013

It is increasingly clear that microRNAs play a crucial role in tumorigenesis. Recently, emerging evidence suggested that miR‐26a is aberrantly expressed in tumor tissues. In our study, frequent down‐regulation of miR‐26a was observed in 10 human bladder cancer tissues. Forced expression of miR‐26a in the bladder cancer cell line T24 inhibited cell proliferation and impaired cell motility. High mobility group AT‐hook 1 (HMGA1), a gene that modulates cell cycle transition and cell motility, was verified as a novel target of miR‐26a in bladder cancer. These findings indicate an important role for miR‐26a in the molecular etiology of bladder cancer and implicate the potential application of miR‐26a in bladder cancer therapy.
Effect of a single preoperative dose of sublingual misoprostol on intraoperative blood loss during total abdominal hysterectomy
Authors: Biswas Jhuma , Chaudhuri Picklu , Mandal Apurba , Bandyopadhyay Sambhu Nath , Dasgupta Shyamal , Pal Anirban
Published: June 2013

Objective

To investigate whether use of preoperative misoprostol can reduce blood loss during total abdominal hysterectomy (TAH).

Methods

In a randomized double‐blind placebo‐controlled trial at a tertiary care hospital in Kolkata, India, between March 2011 and April 2012, women (n = 132) undergoing TAH with or without bilateral salpingo‐oophorectomy for symptomatic myomas were randomly allocated to receive either 400 μg of misoprostol or placebo 30 minutes before surgery. The primary outcome measure was intraoperative blood loss was. The secondary outcomes were postoperative drop in hemoglobin, need for blood transfusion, and incidence of adverse effects.

Results

The 2 groups were similar with regard to demographic and clinical characteristics. There was a significant reduction of blood loss during TAH after sublingual administration of misoprostol compared with placebo before surgery (356 mL vs 435 mL; P = 0.049). The mean postoperative hemoglobin concentration was higher (10.5 g/dL vs 9.5 g/dL; P < 0.001) and the postoperative drop in hemoglobin was smaller (1.1 g/dL vs 1.9 g/dL; P = 0.004) in the misoprostol group than in the placebo group. No significant adverse effects occurred in either group.

Conclusion

The results showed that a single dose of misoprostol administered before abdominal hysterectomy resulted in a significant reduction of blood loss with minimal adverse effects.

Clinical Trial Registry India ( www.ctri.nic.in): CTRI/2011/091/000216.
A systematic review of the evidence for complementary and alternative medicine in infertility
Authors: Clark Natalie A. , Will Matthew , Moravek Molly B. , Fisseha Senait
Published: June 2013

Background

The use of complementary and alternative medicine (CAM) by patients and physicians has increased markedly in recent years. Many case reports, case series, and uncontrolled trials of varying quality have been completed; however, there is now a slowly increasing number of randomized controlled trials (RCTs) examining the use of CAM.

Objectives

To identify, survey, and review RCTs investigating the use of CAM for infertility treatment.

Search strategy

The MEDLINE and Cochrane databases were electronically searched.

Selection criteria

RCTs examining modalities for treatment or improvement of health status were reviewed.

Data collection and analysis

RCTs were included based on use of objective measures, articles written in English, availability through the University of Michigan database, and clear published clinical outcomes.

Main results

Thirty‐seven articles assessing a variety of CAM modalities met inclusion criteria. Acupuncture, selenium supplementation, weight loss, and psychotherapeutic intervention had 3 or more studies demonstrating beneficial effect. Other interventions had been studied less and evidence for them was limited.

Conclusions

Although there is preliminary evidence of the effectiveness of some CAM interventions among infertile patients, many of these interventions require further investigation before they can be considered for routine clinical use.
Risk factors and perinatal outcomes associated with idiopathic small for gestational age Taiwanese newborns
Authors: Hung Tai‐Ho , Hsieh T'sang‐T'ang , Lo Liang‐Ming , Chiu Tsung‐Hung , Hsieh Ching‐Chang , Hsu Jenn‐Jeih
Published: June 2013

Objective

To determine risk factors and perinatal outcomes associated with small for gestational age (SGA) neonates among healthy pregnant women.

Methods

A retrospective cohort study was conducted of 49 945 women who gave birth at Chang Gung Memorial Hospital, Taipei, Taiwan, after 24 weeks of pregnancy. Idiopathic SGA newborns (n = 3398) were characterized by a birth weight below the 10th percentile for mean weight corrected for GA and fetal sex.

Results

Risk factors for idiopathic SGA newborns included hypercoiling of the umbilical cord (adjusted odds ratio [aOR], 3.3; 95% confidence interval [CI], 1.6–7.0); prior fetal death (aOR, 2.8; 95% CI, 2.0–3.9); primiparity (aOR, 1.5; 95% CI, 1.4–1.7); adolescent pregnancy (aOR, 1.5; 95% CI, 1.2–2.0), low prepregnancy weight (aOR, 1.6; 95% CI, 1.5–1.8), low prepregnancy body mass index (aOR, 1.1; 95% CI, 1.0–1.3); short stature (aOR, 1.3; 95% CI, 1.1–1.4); and entangled umbilical cord (aOR, 1.1; 95% CI, 1.0–1.3). Idiopathic SGA newborns correlated with increased risk of adverse perinatal outcomes, including fetal death, low Apgar scores, oligohydramnios, placental abruption, and admission to the neonatal intensive care unit.

Conclusion

Some risk factors for idiopathic SGA newborns were modifiable, suggesting potential implications for public health.
Vaginal cuff dehiscence after hysterectomy
Authors: Koo Yu‐Jin , Kim Dae‐Yeon , Kim Jong‐Hyeok , Kim Yong‐Man , Kim Young‐Tak , Nam Joo‐Hyun
Published: June 2013

Objective

To determine the incidence of vaginal cuff dehiscence (VCD) among women undergoing hysterectomy according to clinico‐surgical factors including surgical route, and to describe patient characteristics associated with VCD.

Methods

In a retrospective study, the medical records of all women who underwent hysterectomy between January 2005 and March 2011 at a university teaching hospital in Seoul, Republic of Korea, were reviewed. The incidence of VCD was determined in relation to the following factors: patient age, hysterectomy route, indication for hysterectomy, and extent of resection (either simple or radical hysterectomy).

Results

Among 9973 hysterectomies, 37 (0.37%) cases of VCD were identified. The incidence of VCD was significantly higher after abdominal hysterectomy (0.6%) than after laparoscopic (0.2%) or vaginal (0.4%) hysterectomy (P = 0.016). Compared with laparoscopic approaches, abdominal hysterectomy was associated with a higher risk of VCD (odds ratio, 2.735; 95% confidence interval, 1.380–5.420). However, there was no significant difference in the incidence of VCD according to surgical indication or extent of resection.

Conclusion

Laparoscopic hysterectomy was found to be associated with a lower risk of VCD compared with abdominal hysterectomy. The lower risk is probably related to the different techniques used for colpotomy and cuff closure.
Understanding the relationship between access to care and facility‐based delivery through analysis of the 2008 Ghana Demographic Health Survey
Authors: Moyer Cheryl A. , McLaren Zoë M. , Adanu Richard M. , Lantz Paula M.
Published: June 2013

Objective

To determine the types of access to care most strongly associated with facility‐based delivery among women in Ghana.

Methods

Data relating to the “5 As of Access” framework were extracted from the 2008 Ghana Demographic Health Survey and analyzed using multivariate logistic regression.

Results

In all, 55.5% of a weighted sample of 1102 women delivered in a healthcare facility, whereas 45.5% delivered at home. Affordability was the strongest access factor associated with delivery location, with health insurance coverage tripling the odds of facility delivery. Availability, accessibility (except urban residence), acceptability, and social access variables were not significant factors in the final models. Social access variables, including needing permission to seek healthcare and not being involved in decisions regarding healthcare, were associated with a reduced likelihood of facility‐based delivery when examined individually. Multivariate analysis suggested that these variables reflected maternal literacy, health insurance coverage, and household wealth, all of which attenuated the effects of social access.

Conclusion

Affordability was an important determinant of facility delivery in Ghana—even among women with health insurance—but social access variables had a mediating role.
New global guidance supports community and lay health workers in postpartum hemorrhage prevention
Authors: Ejembi Clara Ladi , Norick Pamela , Starrs Ann , Thapa Kusum
Published: June 2013

New global guidance has emerged to support countries as they consider introducing or scaling‐up misoprostol for postpartum hemorrhage (PPH). The World Health Organization (WHO) and the International Federation of Gynecology and Obstetrics (FIGO) recognize the critical role that community and lay health workers play in preventing PPH and increasing access to misoprostol where skilled birth attendants are not available. As case examples from Nigeria and Nepal illustrate, community engagement and empowerment are critical strategies in successful misoprostol for PPH programs, and must increasingly be viewed as part of efforts to improve maternal health and achieve Millennium Development Goal 5.
The French model and water challenges in developing countries: Evidence from Jakarta and Manila
Authors: Wu Xun , Ching Leong
Published: June 2013

Despite the growing need for private sector participation (PSP) in the water sector, private sector investments in the water sector have experienced a downturn in recent years, especially concession projects, which accounted for nearly 80 percent of all PSP projects in urban water utilities from 1990 to 2005. This paper traces the concession to its origin—the French model—and focuses on the challenges of transferring the model into the context of developing countries, by comparing two cases of concession projects in Jakarta and Manila. This comparative analysis suggests that although the French model appears a compelling choice because of its promise of attracting capital investments and improving efficiency, successful applications of the model may require substantial modifications to its original form in order to adapt to prevailing legal and social norms as well as to local governance capacity.
100,000-year-long terrestrial record of millennial-scale linkage between eastern North American mid-latitude paleovegetation shifts and Greenland ice-core oxygen isotope trends
Authors: Litwin Ronald J. , Smoot Joseph P. , Pavich Milan J. , Markewich Helaine W. , Brook George , Durika Nancy J.
Published: June 2013

We document frequent, rapid, strong, millennial-scale paleovegetation shifts throughout the late Pleistocene, within a 100,000+ yr interval (~ 115–15 ka) of terrestrial sediments from the mid-Atlantic Region (MAR) of North America. High-resolution analyses of fossil pollen from one core locality revealed a continuously shifting sequence of thermally dependent forest assemblages, ranging between two endmembers: subtropical oak-tupelo-bald cypress-gum forest and high boreal spruce-pine forest. Sedimentary textural evidence indicates fluvial, paludal, and loess deposition, and paleosol formation, representing sequential freshwater to subaerial environments in which this record was deposited. Its total age"depth model, based on radiocarbon and optically stimulated luminescence ages, ranges from terrestrial oxygen isotope stages (OIS) 6 to 1. The particular core sub-interval presented here is correlative in trend and timing to that portion of the oxygen isotope sequence common among several Greenland ice cores: interstades GI2 to GI24 (≈ OIS2–5 d). This site thus provides the first evidence for an essentially complete series of "Dansgaard"Oeschger" climate events in the MAR. These data reveal that the ~ 100,000 yr preceding the Late Glacial and Holocene in the MAR of North America were characterized by frequently and dynamically changing climate states, and by vegetation shifts that closely tracked the Greenland paleoclimate sequence.
A ring-width-based reconstruction of June–July minimum temperatures since AD 1245 from white spruce stands in the Mackenzie Delta region, northwestern Canada
Authors: Porter Trevor J. , Pisaric Michael F.J. , Kokelj Steven V. , deMontigny Peter
Published: June 2013

We present a reconstruction of June–July minimum temperatures since AD 1245 for the Mackenzie Delta region based on a 29-site network of white spruce (Picea glauca) ring-width series. Most but not all trees experienced a divergent temperature–growth response, similar to the divergence that has affected other white spruce trees across Yukon and Alaska. However, divergence in the study region began as early as AD 1900 and we have documented our methods to avoid including divergent signals in the reconstruction. Calibration/verification testing based on local temperature data, and multi-century coherence with nearby and large-scale temperature proxy records, confirm that our reconstruction is robust. The reconstruction shows cool conditions in the late 13th, early 18th and early 19th centuries, corresponding with solar minima and increased volcanism. These cool periods are interrupted by warm periods consistent with early to mid-20th century warmth. The late 20th century is the warmest interval, and the last decade is estimated to be 1.4°C warmer than any decade before the mid-20th century. The reconstructed climate history corroborates other proxy-based inferences and supports the notion that high-latitude regions such as the Mackenzie Delta have experienced rapid warming in recent decades that is exceptional in the last eight centuries.
Establishing mono-eukaryotic Histomonas meleagridis cultures from in vivo infection contaminated with Tetratrichomonas gallinarum and Blastocystis spp.
Authors: PHAM ANH DAO NGUYEN , MAST JAN , DE GUSSEM JEROEN KOEN , MCDOUGALD LARRY R. , GODDEERIS BRUNO MARIA
Published: June 2013

The necessity to easily establish Histomonas meleagridis cultures has been underlined extensively by many researchers in order to gain more insights in the biology of H. meleagridis. In addition the occurrence of different protozoa in the caeca of birds impedes, however, the isolation and propagation of H. meleagridis from field outbreaks. Therefore, in a kinetic study using transmission electron microscopy the deleterious effects of adventitious protozoa including Tetratrichomonas gallinarum and Blastocystis spp. on cultured H. meleagridis were examined. To overcome this issue, an easy and successful approach to establish the mono-eukaryotic H. meleagridis culture free of other host's protozoa is proposed. At 10 days post infection, liver lesions of H. meleagridis-infected birds were isolated and inoculated into culture media pre-incubated with caecal bacteria. After 48 h of incubation, presence of H. meleagridis in the cultures was confirmed through morphological evaluation. Additionally, TEM examination and analysis by PCR amplification of the small subunit rRNA gene could exclude the co-cultivation of T. gallinarum and Blastocystis spp. Furthermore, after successful propagation and maintenance of the cultured H. meleagridis, its pathogenicity was affirmed in an infection experiment in turkeys.
Chancellor Model Picks Merkel in 2013 German Election
Authors: Norpoth Helmut , Gschwend Thomas
Published: June 2013

In the German national election this fall, based on the forecast of the Chancellor Model, the governing coalition will score a resounding victory. Chancellor Angela Merkel enjoys a high approval rating, which puts her at a 2-1 advantage over the challenger, Peer Steinbrück. Although Germany is not a presidential system, where voters elect the chief policymaker, chancellor support has proved to be a strong predictor of vote choice in German national elections. Our forecast model also includes long-term partisanship, which provides a broad base for the governing parties in this election, and length of tenure, which exacts a modest penalty after two terms of office. Since its premiere in 2002, the model has predicted the winner in each election. In a case of perhaps beginner's luck, the 2002 forecast scored a bull's-eye with 47.1%, the exact share of the governing parties; the forecast was posted three months before Election Day. No poll or other model, not even the Election-Day exit polls, came close to this performance; in fact, most people predicted a defeat for Schröder's red-green coalition (Norpoth and Gschwend 2003).
The Vocal Ecology of Crumb's Crickets
Authors: COOK ROBERT C.
Published: June 2013

Making sound is characteristic of agency in the natural world. It is curious therefore that having separated pitched sound from nature as much as possible—disciplined it into scales, temperaments, etc.—Western music has for centuries made extraordinary efforts to imitate natural sounds and processes with this un-natured sound. Whereas music often depicts nature, “music” has become abstract and transparent, and musical sounds themselves have become little more than acoustic tokens of objects related by structure. Any metaphorical connections with extra-musical sounds are suppressed in discourse about music because they constitute “effects.” In this article, I interpret the first movement of George Crumb's Ancient Voices of Children (1970) as an expression of agency in the soundscape, considering vocal sounds, especially those attributed to crickets, as acts in a vocal ecology rather than imitation of natural sounds for programmatic purposes. My analysis invites us to hear this music—and music in general—as acoustic expression in a soundscape and therefore in ecological terms.
Parahydrogen-induced polarization at zero magnetic field
Authors: Butler Mark C. , Kervern Gwendal , Theis Thomas , Ledbetter Micah P. , Ganssle Paul J. , Blanchard John W. , Budker Dmitry , Pines Alexander
Published: June 2013

We use symmetry arguments and simple model systems to describe the conversion of the singlet state of parahydrogen into an oscillating sample magnetization at zero magnetic field. During an initial period of free evolution governed by the scalar-coupling Hamiltonian HJ, the singlet state is converted into scalar spin order involving spins throughout the molecule. A short dc pulse along the z axis rotates the transverse spin components of nuclear species I and S through different angles, converting a portion of the scalar order into vector order. The development of vector order can be described analytically by means of single-transition operators, and it is found to be maximal when the transverse components of I are rotated by an angle of ±π/2 relative to those of S. A period of free evolution follows the pulse, during which the vector order evolves as a set of oscillating coherences. The imaginary parts of the coherences represent spin order that is not directly detectable, while the real parts can be identified with oscillations in the z component of the molecular spin dipole. The dipole oscillations are due to a periodic exchange between Iz and Sz, which have different gyromagnetic ratios. The frequency components of the resulting spectrum are imaginary, since the pulse cannot directly induce magnetization in the sample; it is only during the evolution under HJ that the vector order present at the end of the pulse evolves into detectable magnetization.
Unique water-water coordination tailored by a metal surface
Authors: Schiros T. , Andersson K. J. , MacNaughton J. , Gladh J. , Matsuda A. , Öström H. , Takahashi O. , Pettersson L. G. M. , Nilsson A. , Ogasawara H.
Published: June 2013

At low coverage of water on Cu(110), substrate-mediated electrostatics lead to zigzagging chains along [001] as observed with STM [T. Yamada, S. Tamamori, H. Okuyama, and T. Aruga, “Anisotropic water chain growth on Cu(110) observed with scanning tunneling microscopy” Phys. Rev. Lett. 96, 036105 (2006)]10.1103/PhysRevLett.96.036105. Using x-ray absorption spectroscopy we find an anomalous low-energy resonance at ∼533.1 eV which, based on density functional theory spectrum simulations, we assign to an unexpected configuration of water units whose uncoordinated O–H bonds directly face those of their neighbors; this interaction repeats over trough sites with enhanced electron density and is analogous to the case of a hydrated electron.
Ground state solutions of asymptotically linear fractional Schrödinger equations
Authors: Chang Xiaojun
Published: June 2013

This paper is devoted to a time-independent fractional Schrödinger equation of the form \documentclass[12pt]{minimal}\begin{document}$(-\Delta )^s u+V(x)u=f(x,u)\; \mbox{in}\; \mathbb {R}^{N},$\end{document}(−Δ)su+V(x)u=f(x,u)inRN, where N ⩾ 2, s ∈ (0, 1), (−Δ)s stands for the fractional Laplacian. We apply the variational methods to obtain the existence of ground state solutions when f(x, u) is asymptotically linear with respect to u at infinity.
Surface tension effects on the motion of a free-falling liquid sheet
Authors: Coppola Gennaro , De Rosa Fortunato , de Luca Luigi
Published: June 2013

The stationary motion of a liquid curtain falling under the effects of inertia, gravity, and surface tension is analyzed. An original equation governing the streamwise distribution of thickness and velocity is derived by means of a Taylor expansion in the lateral distance from the mean line of the sheet. Approximate solutions are obtained by means of perturbation approaches involving the two parameters governing the problem, namely, the slenderness ratio ɛ and the Weber number We. The numerical procedure employed in order to integrate the non-linear equation is discussed and a parametric study is presented, together with a comparison with the approximate asymptotic solutions valid for small ɛ and We.
Change of caged dynamics at T
g in hydrated proteins: Trend of mean squared displacements after correcting for the methyl-group rotation contribution
Authors: Ngai K. L. , Capaccioli S. , Paciaroni A.
Published: June 2013

The question whether the dynamics of hydrated proteins changes with temperature on crossing the glass transition temperature like that found in conventional glassformers is an interesting one. Recently, we have shown that a change of temperature dependence of the mean square displacement (MSD) at Tg is present in proteins solvated with bioprotectants, such as sugars or glycerol with or without the addition of water, coexisting with the dynamic transition at a higher temperature Td. The dynamical change at Tg is similar to that in conventional glassformers at sufficiently short times and low enough temperatures, where molecules are mutually caged by the intermolecular potential. This is a general and fundamental property of glassformers which is always observed at or near Tg independent of the energy resolution of the spectrometer, and is also the basis of the dynamical change of solvated proteins at Tg. When proteins are solvated with bioprotectants they show higher Tg and Td than the proteins hydrated by water alone, due to the stabilizing action of excipients, thus the observation of the change of T-dependence of the MSD at Tg is unobstructed by the methyl-group rotation contribution at lower temperatures [S. Capaccioli, K. L. Ngai, S. Ancherbak, and A. Paciaroni, J. Phys. Chem. B 116, 1745 (2012)]10.1021/jp2057892. On the other hand, in the case of proteins hydrated by water alone unambiguous evidence of the break at Tg is hard to find, because of their lower Tg and Td. Notwithstanding, in this paper, we provide evidence for the change at Tg of the T-dependence of proteins hydrated by pure water. This evidence turns out from (i) neutron scattering experimental investigations where the sample has been manipulated by either full or partial deuteration to suppress the methyl-group rotation contribution, and (ii) neutron scattering experimental investigations where the energy resolution is such that only motions with characteristic times shorter than 15 ps can be sensed, thus shifting the onset of both the methyl-group rotation and the dynamic transition contribution to higher temperatures. We propose that, in general, coexistence of the break of the elastic intensity or the MSD at Tg with the dynamic transition at Td in hydrated and solvated proteins. Recognition of this fact helps to remove inconsistency and conundrum encountered in interpreting data of hydrated proteins that thwart progress in understanding the origin of the dynamic transition.
Volume oscillations of a constrained bubble
Authors: Maksimov A. O. , Polovinka Yu. A.
Published: June 2013

The behavior of a single acoustically driven bubble tethered to a wire ring is considered. The method of restraining the bubble against rising by attaching it to a wire is a common procedure in conducting precision acoustic measurements. The dynamics of the tethered bubble differs from those of free bubble due to variation in inertial (or added) mass. The objective of this study is to obtain a closed-form, leading order solution for the volume oscillations, assuming smallness of the bubble radius R0 in comparison with the acoustic wavelength λ. It was shown, by using the invariance of the Laplace equation to conformal transformations and the geometry of the problem, that the toroidal coordinates provide separation of variables and are most suitable for analysis of the oscillations of the tethered bubble. Thus, the dynamics of the bubble restraining by a wire loop in toroidal coordinates can be investigated by using analytical approach and by analogy to the dynamics of a free spherical bubble.
Hydrogen termination of CVD diamond films by high-temperature annealing at atmospheric pressure
Authors: Seshan V. , Ullien D. , Castellanos-Gomez A. , Sachdeva S. , Murthy D. H. K. , Savenije T. J. , Ahmad H. A. , Nunney T. S. , Janssens S. D. , Haenen K. , Nesládek M. , van der Zant H. S. J. , Sudhölter E. J. R. , de Smet L. C. P. M.
Published: June 2013

A high-temperature procedure to hydrogenate diamond films using molecular hydrogen at atmospheric pressure was explored. Undoped and doped chemical vapour deposited (CVD) polycrystalline diamond films were treated according to our annealing method using a H2 gas flow down to ∼50 ml/min (STP) at ∼850 °C. The films were extensively evaluated by surface wettability, electron affinity, elemental composition, photoconductivity, and redox studies. In addition, electrografting experiments were performed. The surface characteristics as well as the optoelectronic and redox properties of the annealed films were found to be very similar to hydrogen plasma-treated films. Moreover, the presented method is compatible with atmospheric pressure and provides a low-cost solution to hydrogenate CVD diamond, which makes it interesting for industrial applications. The plausible mechanism for the hydrogen termination of CVD diamond films is based on the formation of surface carbon dangling bonds and carbon-carbon unsaturated bonds at the applied tempera-ture, which react with molecular hydrogen to produce a hydrogen-terminated surface.
Intensity oscillations in the carbon 1s ionization cross sections of 2-butyne
Authors: Carroll Thomas X. , Zahl Maria G. , Børve Knut J. , Sæthre Leif J. , Decleva Piero , Ponzi Aurora , Kas Joshua J. , Vila Fernando D. , Rehr John J. , Thomas T. Darrah
Published: June 2013

Carbon 1s photoelectron spectra for 2-butyne (CH3C≡CCH3) measured in the photon energy range from threshold to 150 eV above threshold show oscillations in the intensity ratio C2,3/C1,4. Similar oscillations have been seen in chloroethanes, where the effect has been attributed to EXAFS-type scattering from the substituent chlorine atoms. In 2-butyne, however, there is no high-Z atom to provide a scattering center and, hence, oscillations of the magnitude observed are surprising. The results have been analyzed in terms of two different theoretical models: a density-functional model with B-spline atom-centered functions to represent the continuum electrons and a multiple-scattering model using muffin-tin potentials to represent the scattering centers. Both methods give a reasonable description of the energy dependence of the intensity ratios.
Energy savings from using mobile smart technologies
Authors: Këpuska Veton , Karaffa Paul , Shaw Guinevere , Zurasky Jacob , Kovalik Christopher , Arnold Jordan , Macaraig Salvador
Published: June 2013

This paper presents the most recent results of energy saving benefits from the convergence of consumer products into a multi-function smart device, such as a smartphone or tablet, compared to single-function products (e.g., an electronic clock). Although individual users are predominantly driven only by the marked trends and the individual energy savings are moderate, the sheer number of users makes this global trend promising and a model for sustainable energy. The energy consumption of selected smart devices was tested using 42 frequently used applications and utilities (e.g., portable gaming, scanning, music players, etc.). A range of Operating Systems (OS) were selected for testing: Android OS (Google), Blackberry OS (RIM), iOS (Apple), and Windows 7 OS (Microsoft). Testing was conducted using the following smartphones: Blackberry Curve 9300, iPhone 4, Samsung Focus, Samsung Galaxy S; and tablets: iPad 2 and Samsung Galaxy Tablet 7″. In order to investigate the battery consumption, two programs were developed in-house for iOS and Android platforms. For the Windows phone, the built-in program was utilized, while a third-party application was used for the Blackberry phone. To further test the battery, each device was also decoupled from its battery and hooked up through a measuring device, and experiments were then repeated. This study shows smart devices save consumers up to $150 annually compared to single-function devices in a range of applications. The results from this study demonstrate how smart devices are transforming our society by providing superior functionality at a lesser cost in energy, paving the way for other technologies to be integrated into smart devices, and energy reduction to continue. The error in measurement was estimated using standard techniques utilizing 95% confidence scoring for each of the measurements. According to these results that assume normal distribution of measurement error, we show that our measurements were done correctly and the results are significant to within margin of error of ±0.0249 and ±0.0775 for intrusive measurements for smart phones and tablets and for non-intrusive measurements for smart phones and tablets, respectively, of ±0.497 and ±0.325.