bluuebunny/crossref_metadata_2025 huggingface dataset:
The structures of nonprotein‐coding RNAs that drive internal ribosome entry site function
Authors: Plank Terra‐Dawn M. , Kieft Jeffrey S.
Published: January 2012

Internal ribosome entry sites (IRESs) are RNA sequences that can recruit the translation machinery independent of the 5′ end of the messenger RNA. IRESs are found in both viral and cellular RNAs and are important for regulating gene expression. There is great diversity in the mechanisms used by IRESs to recruit the ribosome and this is reflected in a variety of RNA sequences that function as IRESs. The ability of an RNA sequence to function as an IRES is conferred by structures operating at multiple levels from primary sequence through higher‐order three‐dimensional structures within dynamic ribonucleoproteins (RNPs). When these diverse structures are compared, some trends are apparent, but overall it is not possible to find universal rules to describe IRES structure and mechanism. Clearly, many different sequences and structures have evolved to perform the function of recruiting, positioning, and activating a ribosome without using the canonical cap‐dependent mechanism. However, as our understanding of the specific sequences, structures, and mechanisms behind IRES function improves, more common features may emerge to link these diverse RNAs. WIREs RNA 2012, 3:195–212. doi: 10.1002/wrna.1105

This article is categorized under:

RNA Structure and Dynamics > Influence of RNA Structure in Biological Systems

Translation > Translation Mechanisms

Translation > Translation Regulation
Primary Surgery in Rural Areas of Southern Sudan
Authors: Cometto Giorgio , Belgrano Edoardo , De Bonis Umberto , Giustetto Guido , Kiss Alberto , Taliente Peter , Meo Giuseppe
Published: January 2012

Background

We report through a retrospective analysis our experience of providing surgical care and on‐the‐job training through mobile surgical missions in southern Sudan during the post conflict period between 2005 and 2009.

Methods

Three surgical teams conducted 23 missions in 5 primary health care centers sited in remote areas of southern Sudan. King’s analytical framework for surgical care in developing countries is adopted to evaluate the appropriateness of services rendered. Exact logistic regression was performed to investigate differences in mortality depending on the level of training of the operators and anesthetists.

Results

A total of 1,543 patients were operated on during a 5 year period, of which 9 (0.58%) died. The majority of operations were elective surgery cases (which may help contextualize the exceptionally low mortality rate). Several adaptations to surgical techniques adopted and preoperative and postoperative care were required. There were no statistically significant differences in mortality between operations performed by expatriate specialists and local midlevel providers with lower level training.

Conclusions

This experience in southern Sudan demonstrates that surgical services can be established utilizing simple facilities and equipment and employing local personnel selected and trained on‐the‐job by teams composed of a consultant surgeon, anesthetist, and scrub nurse. Delegation of tasks relating to anesthesia and surgery to midlevel health providers is an appropriate approach in developing countries facing shortage and maldistribution of more qualified health workers.
Pathways to Asian Civilizations: Tracing the Origins and Spread of Rice and Rice Cultures
Authors: Fuller Dorian Q.
Published: January 2012

Modern genetics, ecology and archaeology are combined to reconstruct the domestication and diversification of rice. Early rice cultivation followed two pathways towards domestication in India and China, with selection for domestication traits in early Yangtzejaponicaand a non-domestication feedback system inferred for ‘proto-indica’. The protracted domestication process finished around 6,500–6,000 years ago in China and about two millennia later in India, when hybridization with Chinese rice took place. Subsequently farming populations grew and expanded by migration and incorporation of pre-existing populations. These expansions can be linked to hypothetical language family dispersal models, including dispersal from China southwards by the Sino-Tibetan and Austronesian groups. In South Asia much dispersal of rice took place after Indo-Aryan and Dravidian speakers adopted rice from speakers of lost languages of northern India.
Family Structure Transitions and Changes in Maternal Resources and Well-being
Authors: Osborne Cynthia , Berger Lawrence M. , Magnuson Katherine
Published: January 2012

This article uses data from the Fragile Families and Child Wellbeing Study to examine whether family instability is associated with changes in perceived social support, material hardship, maternal depression, and parenting stress among mothers of young children. In addition to accounting for the number of transitions that a mother experiences during the first five years of her child’s life, we pay close attention to the type and timing of these transitions. We find that mothers who transition to cohabitation or marriage with their child’s biological father experience declines in material hardship and that those who transition to cohabitation or marriage with another man exhibit modest declines in both material hardship and depression. Mothers who exit cohabiting or marital relationships encounter decreases in perceived social support and increases in material hardship, depression, and parenting stress. Overall, our results suggest that both the type and, to a much lesser degree, the timing of family structure transitions may influence maternal well-being.
The deglacial history of NW Alexander Island, Antarctica, from surface exposure dating
Authors: Johnson Joanne S. , Everest Jeremy D. , Leat Philip T. , Golledge Nicholas R. , Rood Dylan H. , Stuart Finlay M.
Published: January 2012

Recent changes along the margins of the Antarctic Peninsula, such as the collapse of the Wilkins Ice Shelf, have highlighted the effects of climatic warming on the Antarctic Peninsula Ice Sheet (APIS). However, such changes must be viewed in a long-term (millennial-scale) context if we are to understand their significance for future stability of the Antarctic ice sheets. To address this, we present nine new cosmogenic 10Be exposure ages from sites on NW Alexander Island and Rothschild Island (adjacent to the Wilkins Ice Shelf) that provide constraints on the timing of thinning of the Alexander Island ice cap since the last glacial maximum. All but one of the 10Be ages are in the range 10.2–21.7 ka, showing a general trend of progressive ice-sheet thinning since at least 22 ka until 10 ka. The data also provide a minimum estimate (490 m) for ice-cap thickness on NW Alexander Island at the last glacial maximum. Cosmogenic 3He ages from a rare occurrence of mantle xenoliths on Rothschild Island yield variable ages up to 46 ka, probably reflecting exhumation by periglacial processes.
Effect of vitamin D supplementation during pregnancy on neonatal mineral homeostasis and anthropometry of the newborn and infant
Authors: Kalra Pramila , Das Vinita , Agarwal Anjoo , Kumar Mala , Ramesh V. , Bhatia Eesh , Gupta Sarika , Singh Swati , Saxena Priya , Bhatia Vijayalakshmi
Published: January 2012

Hypovitaminosis D is common in India. In the present prospective partially randomised study of vitamin D (D3) supplementation during pregnancy, subjects were randomised in the second trimester to receive either one oral dose of 1500 μg vitamin D3(group 1,n48) or two doses of 3000 μg vitamin D3each in the second and third trimesters (group 2,n49). Maternal 25-hydroxyvitamin D (25(OH)D) at term, cord blood (CB) alkaline phosphatase (ALP), neonatal serum Ca and anthropometry were measured in these subjects and in forty-three non-supplemented mother–infant pairs (usual care). Median maternal 25(OH)D at term was higher in group 2 (58·7, interquartile range (IQR) 38·4–89·4 nmol/l)v. group 1 (26·2, IQR 17·7–57·7 nmol/l) and usual-care group (39·2, IQR 21·2–73·4 nmol/l) (P = 0·000). CB ALP was increased (>8.02 μkat/l or >480 IU/l) in 66·7 % of the usual-care groupv. 41·9 % of group 1 and 38·9 % of group 2 (P = 0·03). Neonatal Ca and CB 25(OH)D did not differ significantly in the three groups. Birth weight, length and head circumference were greater and the anterior fontanelle was smaller in groups 1 and 2 (3·08 and 3·03 kg, 50·3 and 50·1 cm, 34·5 and 34·4 cm, 2·6 and 2·5 cm, respectively)v. usual care (2·77 kg, 49·4, 33·6, 3·3 cm;P = 0·000 for length, head circumference and fontanelle andP = 0·003 for weight). These differences were still evident at 9 months. We conclude that both 1500 μg and two doses of 3000 μg vitamin D3had a beneficial effect on infant anthropometry, the larger dose also improving CB ALP and maternal 25(OH)D.
Dietary arginine supplementation alleviates immune challenge induced bySalmonella entericaserovar Choleraesuis bacterin potentially through the Toll-like receptor 4-myeloid differentiation factor 88 signalling pathway in weaned piglets
Authors: Chen Yu , Chen Daiwen , Tian Gang , He Jun , Mao Xiangbing , Mao Qian , Yu Bing
Published: January 2012

The present study evaluated whether dietary arginine (Arg) supplementation could attenuate immune challenge induced bySalmonella entericaserovar Choleraesuis C500 (S.C500) through the Toll-like receptor (TLR) 4-myeloid differentiation factor 88 (Myd88) signalling pathway in weaned piglets. A total of thirty-six weaned pigs were randomly allocated into six groups with six replicates per group. Pigs were subjected to three dietary treatments (namely two groups per treatment) in the first week (0–7 d) and fed with diets containing 0, 0·5 and 1·0 %l-Arg, respectively. On day 8, pigs were injected intramuscularly either with S.C500 or sterile saline. Serum samples were collected at day 8 (before injection), and at 1, 3 and 10 d post-injection, pigs were killed for evaluation of tissue gene expression following the last blood collection. Piglets fed the diets with 0·5 or 1·0 % Arg supplementation had a higher concentration of serum Arg (P < 0·05). S.C500-challenged piglets had higher (P < 0·05) serum antibody levels during the days 9–18. Weight gain and feed intake were decreased remarkably (P < 0·01) after the injection of S.C500, and 0·5 or 1·0 % Arg supplementation tended to alleviate the inhibition. The S.C500 challenge significantly enhanced (P < 0·05) serum C-reactive protein (CRP), interferon-γ and IL-12 concentrations, but Arg supplementation attenuated (P < 0·05) the increase in CRP level. The mRNA expression of TLR4, TLR5, Myd88, p65 NF-κB and TNF-α was up-regulated (P < 0·05) by the S.C500 challenge in different tissues, but was down-regulated (P < 0·05) by Arg supplementation. In conclusion, Arg supplementation could inhibit the excessive activation of the TLR4-Myd88 signalling pathway and thus attenuated the negative effects caused by the immune challenge of S.C500.
Role of hepaticde novolipogenesis in the development of fasting-induced fatty liver in the American mink (Neovison vison)
Authors: Rouvinen-Watt Kirsti , Harris Lora , Dick Morag , Pal Catherine , Lei Sha , Mustonen Anne-Mari , Nieminen Petteri
Published: January 2012

American mink (Neovison vison) develop fatty liver quickly in response to food deprivation, which results in preferential mobilisation ofn-3 PUFA. The alteredn-3:n-6 PUFA ratio in the liver may activate the endocannabinoid system resulting in increased lipid synthesis. The objective of the present study was to investigate the effects of feeding intensity (80 or 120 % RDA), dietary fat source (n-3,n-6 orn-9 fatty acids (FA)) and short-term fasting (1–7 d) on hepaticde novolipogenesis (DNL) and the development of fatty liver in mink. Significantly elevated expression of mRNA encoding for acetyl-CoA carboxylase-1 (ACC-1) and FA synthase (FAS) was observed in the liver of mink fasted for 5–7 d, while upon re-feeding for 28 d after a 7 d food deprivation, DNL returned to pre-fasting levels. The females had a higher expression of ACC-1 and FAS mRNA than the males. In the non-fasted animals, dietary fat source and feeding intensity had significant effects on ACC-1 mRNA. The highest levels were observed in the mink fed the rapeseed oil (n-9) diet at 80 % RDA, while the lowest levels were seen when the same diet was fed at 120 % RDA. For FAS, the highest gene expression was seen in the fasted mink fed at 80 % RDA and the lowest in the non-fasted mink fed at 80 %. It is concluded that short-term food deprivation induces hepatic lipidosis in mink and that during this process, hepatic DNL further exacerbates liver fat accumulation.
Changing memory of food enjoyment to increase food liking, choice and intake
Authors: Robinson Eric , Blissett Jackie , Higgs Suzanne
Published: January 2012

Novel ways to increase liking and intake of food are needed to encourage acceptance of healthier food. How enjoyable we remember food to have been is likely to be a significant predictor of food choice. Two studies examined whether remembered enjoyment of eating a food can be increased and whether this makes individuals more likely to eat that food in the future. In Study One, a simple manipulation of instructing participants to rehearse what they found enjoyable about a food immediately after eating it was used to increase remembered enjoyment (relative to controls). In a separate study; Study Two, the effect of increasing remembered enjoyment on food choice was tested by examining whether the manipulation to increase remembered enjoyment resulted in participants choosing to eat more of a food as part of a later buffet lunch. The experimental manipulation increased remembered enjoyment for the food (Study One). A change in remembered enjoyment was shown to have a significant effect on the amount of a food participants chose to eat the following day for lunch (Study Two). The present studies suggest that remembered enjoyment can be increased via a simple act of rehearsal, resulting in a later increase in the amount of food chosen and eaten. Interventions based on altering remembered enjoyment of healthy food choices warrant further investigation.
INCOME INEQUALITY AND OBESITY PREVALENCE AMONG OECD COUNTRIES
Authors: SU DEJUN , ESQUEDA OMAR A. , LI LIFENG , PAGÁN JOSÉ A.
Published: January 2012

Using recent pooled data from the World Health Organization Global Infobase and the World Factbook compiled by the Central Intelligence Agency of the United States, this study assesses the relation between income inequality and obesity prevalence among 31 OECD countries through a series of bivariate and multivariate linear regressions. The United States and Mexico well lead OECD countries in both obesity prevalence and income inequality. A sensitivity analysis suggests that the inclusion or exclusion of these two extreme cases can fundamentally change the findings. When the two countries are included, the results reveal a positive correlation between income inequality and obesity prevalence. This correlation is more salient among females than among males. Income inequality alone is associated with 16% and 35% of the variations in male and female obesity rates, respectively, across OECD countries in 2010. Higher levels of income inequality in the 2005–2010 period were associated with a more rapid increase in obesity prevalence from 2002 to 2010. These associations, however, virtually disappear when the US and Mexico have been excluded from the analysis. Findings from this study underscore the importance of assessing the impact of extreme cases on the relation between income inequality and health outcomes. The potential pathways from income inequality to the alarmingly high rates of obesity in the cases of the US and Mexico warrant further research.
The ‘patient journey’ of adults with sudden-onset acquired hearing impairment: a pilot study
Authors: Manchaiah V K C , Stephens D
Published: January 2012

Objective:

A previous study examined the ‘patient journey’ of adults with gradual-onset acquired hearing impairment. This study examined the same for adults with sudden-onset acquired hearing impairment, and assessed differences.

Study design:

Data were collected from 16 audiologists, using the Ida Institute template, and from four adults with sudden-onset acquired hearing impairment, through semi-structured interviews. Data were analysed using thematic analysis and presented using a process mapping model.

Results:

A patient journey template for sudden-onset acquired hearing impairment was developed based on the professionals' and patients' perspectives. The main difference between these two groups' perspectives was seen in the self-evaluation phase: some stages within this phase were recognised by the patients but not by the professionals. The main difference between the current and the previous study was the absence of a pre-awareness phase in the journey described by patients with sudden-onset acquired hearing impairment, compared with that described by patients with gradual-onset acquired hearing impairment.

Conclusion:

Patient journey templates could be useful counselling tools for ear and hearing healthcare specialists. However, such templates should be used only as a baseline; it is important to take a detailed case history to understand each patient's unique experience, including the psychosocial impact of hearing impairment.
The curious memoirs of the Vietnamese composer Phạm Duy
Authors: Schafer John C.
Published: January 2012

This article reviews the memoirs of Phạm Duy, a famous Vietnamese composer, who in the late 1930s and 1940s composed some of the first modern Vietnamese songs. His memoirs describe his time with the anti-French Resistance, his break with it in 1950, and his years in Saigon and the United States. My review focuses on curious aspects of these memoirs: Phạm Duy's careful listing of his many love affairs; his insistence that he needed lovers to compose songs; and his failure to acknowledge that he profited from a culture that glorifies the self-sacrifice of women. After considering whether Phạm Duy's behaviour as depicted in his memoirs conforms to cultural norms for Vietnamese male artists, I argue that it is best seen as, in Judith Butler's expression, a ‘hyperbolic exhibition’ of the natural. I conclude by speculating about how Phạm Duy and his memoirs may be viewed in future years.
Connecting places, constructing Tết: Home, city and the making of the lunar New Year in urban Vietnam
Authors: McAllister Patrick
Published: January 2012

This paper presents an overview of the main features and nature of Tết, the Vietnamese lunar New Year festival, as it is currently experienced in Hồ Chí Minh City. It outlines a variety of social practices associated with Tết and suggests that it is through these that one can identify a ‘festive landscape’ in the city, within which a number of diverse places are made into and experienced as ‘meaningful space’ in the context of the Tết festival. The emphasis is on how the spatial practices associated with the festival constitute the lived experience of Tết by urban residents and on how this both transforms and connects various sites. Of particular importance here is the family home and how it is linked to the wider holistic experience of Tết, bringing together in a single place sacred and secular, public and private, and the production and consumption of place, in a social construction that is characterised as a heterotopia.
State, enterprise and the alcohol monopoly in colonial Vietnam
Authors: Sasges Gerard
Published: January 2012

The state-administered monopoly on the production of distilled rice alcohol instituted in Vietnam after 1897 evolved into one of the colony's most pervasive and unpopular institutions. This article examines the origins and operations of the monopoly, focusing on how much revenue it generated and for whom. It reveals that the monopoly generated little net revenue for the state, and instead functioned to promote the creation of a centralised and ostensibly civilian administration, capable of intervening in the economy to promote the accumulation of capital by local French entrepreneurs, but ultimately dependent on vast, invasive and frequently brutal systems of surveillance and control.
Bacterial response to a weak 2006 El Niño condition in an upwelling area of the Humboldt Current System
Authors: Fuentes Marcelo , Escribano Rubén , Cuevas L. Antonio
Published: January 2012

Abundance and production of the pelagic heterotrophic bacteria community were studied at northern Chile during winter and summer periods of 2006–2007 in relation to seasonal changes in physical and chemical variables, including the influence of a weak El Niño event. Bacterial abundance was estimated by flow cytometry and secondary bacterial production by protein synthesis after bacterial uptake of14C-isoleucine. Bacterial biomass showed high values in the range of 2.84 at 96.6 µ g C l−1d−1with a bacterial growth efficiency (BGE) of 37.4% in the summer of 2007, and 2.7% in the winter of 2006. High amounts of C (~1.2 to 1.8 g C m−2d−1) were used for bacterial respiration in the upper 20 m. Environmental impact on bacterial abundance and BGE was reflected in a positive correlation with phytoplankton biomass (r2 > 0.40P < 0.05), and a lack of correlation with temperature (P > 0.05). Seasonal differences in abundance and BGE were mainly attributed to an ‘abnormally’ warm winter of 2006, which caused a greater stratification of the water column—a weaker and much deeper oxycline. The oxycline is normally shallower (<20 m) in the zone because of the ascent of the oxygen minimum zone (OMZ) upon upwelling. Winter 2006 conditions indicated presence of a weak El Niño event. Bacteria abundance increased during this warming event, but their metabolic activity was drastically reduced, resulting in a very low BGE. Our study suggests that changes from a prevailing sub-oxic to a highly oxygenated water column could have impacted the bacterial community, thus reducing its productive capacity. Therefore, variation in vertical distribution of the OMZ forced by upwelling variability and the El Niño impact might play an important role in the dynamics of the microbial component in this highly productive upwelling system.
A bidirectional study on the acquisition of plural noun phrase interpretation in English and Spanish
Authors: IONIN TANIA , MONTRUL SILVINA , CRIVOS MÓNICA
Published: January 2012

This paper investigates how learners interpret definite plural noun phrases (e.g., the tigers) and bare (article-less) plural noun phrases (e.g., tigers) in their second language. Whereas Spanish allows definite plurals to have both generic and specific readings, English requires definite plurals to have specific, nongeneric readings. Generic readings in English are expressed with bare plurals, which are ungrammatical in Spanish in preverbal subject position. Two studies were conducted in order to investigate the role of first language transfer in this domain in both English → Spanish and Spanish → English directions. Study 1 used a meaning-focused task to probe learners’ interpretation of definite plural nour phrases, whereas Study 2 used a form-focused task to examine learners’ judgments of the acceptability of definite and bare plurals in generic versus specific contexts. First language transfer was attested in both directions, at lower proficiency levels, whereas more targetlike performance was attested at higher proficiency levels. Furthermore, learners were found to be more successful in learning about the (un)grammaticality of bare plurals in the target language than in assigning the target interpretation to definite versus bare plurals. This finding is shown to be consistent with other studies’ findings of plural noun phrase interpretation in monolingual and bilingual children.
Meeting Report: Microscopy & Microanalysis 2011
Authors: Giovannucci David
Published: January 2012

Like that nourishing Music City confection, this year's Microscopy & Microanalysis Meeting, held August 7–11 in Nashville, was a GooGoo Cluster of top-notch science and networking. M&M is the annual meeting for the Microscopy Society of America, the Microanalysis Society, and the International Metallographic Society. It is the premier conference for microscopists working in the physical, life, and analytical sciences. This year's conference attracted 1,607 scientific attendees from 35 countries; the total number of attendees was 2,629. The perennially successful exhibitors' floor was again noteworthy with 113 companies providing the opportunity to wander 362 booths (9% more than the previous year) occupying 36,200 square feet with state-of-the-art instrumentation and publications.
Standards-Based Quantification in DTSA-II—Part II
Authors: Ritchie Nicholas W.M.
Published: January 2012

This article is the fourth in a series describing the setup and use of NIST DTSA-II. The previous articles may be viewed in the Microscopy Today archives at www.microscopy-today.com. Part I of this article described how to use DTSA-II to quantify an energy dispersive X-ray spectrum from a material of unknown composition. That presentation covered each step and provided background material but lacked a concrete example. This follow-up article provides two such examples.
I Can See Clearly Now!
Authors: Carmichael Stephen W.
Published: January 2012

An important challenge in microscopy is the development of high-resolution light microscopy methods to label and image cell populations in three dimensions. The ability to achieve this deep into intact specimens is limited by light scattering. Modern technologies, such as two-photon excitation fluorescence microscopy, allow examination of structures at distances of hundreds of micrometers below the surface but are insufficient to image and reconstruct large cell populations that are millimeters in scale and deeper below the surface. Whereas light scattering can be reduced by optical clearing, most of these reagents exhibit limitations such as the quenching of fluorescence. Recently, a clearing agent that spectacularly alleviates these major limitations was developed by Hiroshi Hama, Hiroshi Kurokawa, Hiroyuki Kawano, Ryoko Ando, Tomomi Shimogori, Hisayori Noda, Kiyoko Fukami, Asako Sakaue-Sawano, and Atsushi Miyawaki. They developed a clearing reagent called Scale that renders mouse brains and embryos transparent while completely preserving fluorescent signals from labeled cells!
Pioneers in Optics: James Clerk Maxwell and Chandrasekhar Venkata Raman
Authors: Davidson Michael W.
Published: January 2012

James Clerk Maxwell was one of the greatest scientists of the nineteenth century. He is best known for the formulation of the theory of electromagnetism and for making the connection between light and electromagnetic waves. He also made significant contributions in the areas of physics, mathematics, astronomy, and engineering. He is considered by many to be the father of modern physics.
NetNotes
Authors: Phillips Thomas E.
Published: January 2012

Selected postings to the Microscopy Listserver from September 1, 2011 to October 31, 2011. Complete listings and subscription information can be obtained at http://www.microscopy.com. Postings may have been edited to conserve space or for clarity.
A qualitative comparison of cognitive-behavioural and evidence-based clinical supervision
Authors: Milne Derek L. , Reiser Robert P. , Cliffe Tom , Breese Lauren , Boon Annabel , Raine Rosamund , Scarratt Phillippa
Published: January 2012

Despite the acknowledged importance of clinical supervision, controlled research is minimal and has rarely addressed the measurement or manipulation of clinical supervision, hampering our understanding and application of the different supervision methods. We therefore compared two related approaches to supervision, cognitive-behavioural (CBT) and evidence-based clinical supervision (EBCS), evaluating their relative effectiveness in facilitating the experiential learning of one supervisee. Drawing on a multiple-baselineN= 1 design, we gathered mostly qualitative data by means of an episode analysis, a content analysis, a satisfaction questionnaire, and interviews with the supervisor and supervisee. We found that the EBCS approach was associated with higher supervision fidelity and increased engagement in experiential learning by the supervisee. This case study in the evaluation of supervision illustrates the successful application of some rarely applied qualitative methods and some potential supervision enhancements, which could contribute to the development of CBT supervision.
Impact of a monotonic advection scheme with low numerical diffusion on transport modeling of emissions from biomass burning
Authors: Freitas S. R. , Rodrigues L. F. , Longo K. M. , Panetta J.
Published: January 2012

An advection scheme, which maintains the initial monotonic characteristics of a tracer field being transported and at the same time produces low numerical diffusion, is implemented in the Coupled Chemistry‐Aerosol‐Tracer Transport model to the Brazilian developments on the Regional Atmospheric Modeling System (CCATT‐BRAMS). Several comparisons of transport modeling using the new and original (non‐monotonic) CCATT‐BRAMS formulations are performed. Idealized 2‐D non‐divergent or divergent and stationary or time‐dependent wind fields are used to transport sharply localized tracer distributions, as well as to verify if an existent correlation of the mass mixing ratios of two interrelated tracers is kept during the transport simulation. Further comparisons are performed using realistic 3‐D wind fields. We then perform full simulations of real cases using data assimilation and complete atmospheric physics. In these simulations, we address the impacts of both advection schemes on the transport of biomass burning emissions and the formation of secondary species from non‐linear chemical reactions of precursors. The results show that the new scheme produces much more realistic transport patterns, without generating spurious oscillations and under‐ and overshoots or spreading mass away from the local peaks. Increasing the numerical diffusion in the original scheme in order to remove the spurious oscillations and maintain the monotonicity of the transported field causes excessive smoothing in the tracer distribution, reducing the local gradients and maximum values and unrealistically spreading mass away from the local peaks. As a result, huge differences (hundreds of %) for relatively inert tracers (like carbon monoxide) are found in the smoke plume cores. In terms of the secondary chemical species formed by non‐linear reactions (like ozone), we found differences of up to 50% in our simulations.
Acquiring Knowledge of Derived Nominals and Derived Adjectives in Context
Authors: Marinellie Sally A. , Kneile Lynn A.
Published: January 2012

Purpose

This research investigated children’s ability to acquire semantic and syntactic knowledge of derived nominals and derived adjectives in the context of short passages. The study also investigated the relation of morphological awareness and the ability to acquire knowledge of derived words in context.

Method

A total of 106 children in Grade 4 were given an author-created evaluation, the Derivational Acquisition in Context Evaluation (DAICE), which consisted of several short passages. Each passage contained two instances of a target base word followed by one instance of a derived form of the base word. A multiple-choice measure was administered to assess the children’s knowledge of 12 derived words (6 nominals and 6 adjectives). A measure of morphological awareness was given to assess the children’s relational knowledge between root words and their suffixes.

Results

No significant differences were found for overall performance on derived nominals and derived adjectives. However, the acquisition of semantic and syntactic knowledge was dependent on target word type. A significant relation was found between performance on the measure of morphological awareness and performance on derived nominals.

Conclusion

This research provided evidence for fast mapping of derived nominals and derived adjectives within the context of short passages. Future directions of related research are suggested.
Survey of High School Students' Perceptions About Their iPod Use, Knowledge of Hearing Health, and Need for Education
Authors: Danhauer Jeffrey L. , Johnson Carole E. , Dunne Aislinn F. , Young Matthew D. , Rotan Suzanne N. , Snelson Tasha A. , Stockwell Jennifer S. , McLain Michelle J.
Published: January 2012

Purpose

High school students' knowledge about hearing health and their perceptions of how they use personal listening devices (PLDs) including iPods were surveyed to determine the need, content, and preferred format for educational outreach to them.

Method

This study was a descriptive convenience survey of students at a California high school. An 83-item questionnaire was administered in December 2009 to assess students' demographics, knowledge of hearing health, perceived iPod use, and risk activities.

Results

The response rate was 56%. Most of the students perceived that they used iPods safely. However, responses indicated that many of the respondents could be at risk of injury to themselves or others if they became unaware of their surroundings while listening to iPods. Some students were knowledgeable about hearing health and safe iPod use, but most needed information about hearing loss and hearing conservation.

Conclusion

Most of the students needed education (e.g., via health classes or the Internet) about hearing health, the warning signs of hearing loss, and how to prevent hearing loss. Resources for educational audiologists are provided.
Dynamic Assessment of Word Learning Skills: Identifying Language Impairment in Bilingual Children
Authors: Kapantzoglou Maria , Restrepo M. Adelaida , Thompson Marilyn S.
Published: January 2012

Purpose

Bilingual children are often diagnosed with language impairment, although they may simply have fewer opportunities to learn English than English-speaking monolingual children. This study examined whether dynamic assessment (DA) of word learning skills is an effective method for identifying bilingual children with primary language impairment (PLI).

Method

Fifteen 4- and 5-year-old predominantly Spanish-speaking children with typical language development (TLD) and 13 with PLI each participated in a 30- to 40-min session of DA of word learning skills following a pretest–teach–posttest design.

Results

Results indicated that TLD children made associations between the phonological and semantic representations of the new words faster than children with PLI did, showing greater modifiability. Further, a combination of word learning in the receptive modality and the Learning Strategies Checklist (Lidz, 1991; Peña, 1993) provided the best accuracy in identifying PLI in these children.

Conclusion

Findings suggest that a brief DA is a promising method for accurately differentiating children with TLD from children with PLI.
Magnetoresistance of nanocarbon materials based on carbon nanotubes
Authors: Len T. A. , Matzui L. Yu. , Ovsienko I. V. , Prylutskyy Yu. I. , Andrievskii V. V. , Berkutov I. B. , Grechnev G. E. , Kolesnichenko Yu. A.
Published: January 2012

The results of experimental investigations of magnetoresistance in nanocarbon material (NCM) containing carbon nanotubes in magnetic field up to 5 T and at temperature up to 0.54 K are reported. The obtained experimental magnetoresistance curves of NCM are described satisfactorily within the framework of the shrinkage effect of wave function of localized state in a magnetic field along with the spin-polarization mechanism.
Collective modes in quantum Fermi liquid
Authors: Tsintsadze Nodar L. , Tsintsadze Levan N.
Published: January 2012

Landau’s theory of Fermi liquids is generalized by incorporating the de Broglie waves diffraction. A newly derived kinetic equation of the Fermi particles is used to derive a general dispersion relation and the excitation of zero sound is studied. A new mode is found due to the quantum correction. It is shown that the zero sound can exist even in an ideal Fermi gas. We also disclose a new branch of frequency spectrum due to the weak interaction.
New low-dimensional molecular conductors: α′′-(BEDO-TTF)2Cl·3H2O and θ-(BDH-TTP)2(Br0.67Cl0.33)·3H2O
Authors: Zorina L. V. , Simonov S. V. , Khasanov S. S. , Shibaeva R. P.
Published: January 2012

X-ray single-crystal diffraction studies of two new molecular conductors α′′-(BEDO-TTF)2Cl·3H2O and θ-(BDH-TTP)2(Br0.67Cl0.33)·3H2O are reported. Both crystals have a layered structure in which conducting layers of organic BEDO-TTF or BDH-TTP π-electron donors are separated by complex anion layers. The anion layers consist of honeycomb networks of Cl− (Br−) halogen anions and water molecules, which are stable owing to the formation of hydrogen bonds. Calculations of the electron band structure of these crystals show that metallic conductivity is to be expected in the organic α′′-(BEDO-TTF) and θ-(BDH-TTP) layers.
Peculiarities of fluctuation conductivity and pseudogap behavior in slightly doped HoBa2Cu3O7−δ single crystals under pressure
Authors: Solovjov A. L. , Tkachenko M. A. , Vovk R. V. , Obolenskii M. A.
Published: January 2012

The effect of hydrostatic pressure up to 5 kbar on fluctuation conductivity σ′(T) and pseudogap Δ*(T) of slightly doped high-Tc single crystals (HTSC) of HoBa2Cu3O7−δ was investigated. It is shown that the dependence σ′(T) near Tc is well described by the Aslamazov-Larkin and Hikami-Larkin fluctuation theories, demonstrating the 3D–2D crossover with increasing temperature. Δ*(T) exhibits two unexpected maxima at Tm1 ≈ 195 K and Tm2 ≈ 210 K, possibly due to the two-phase state of the single crystal. Pressure-induced redistribution of labile oxygen leads to the disappearance of these peaks and a linear dependence Δ*(T) with a positive slope at high temperatures. Notably, when the pressure is removed, peaks are restored. In general, dependencies of σ′(T) and Δ*(T) are significantly different from those obtained for YBCO films with varying oxygen content. They resemble dependencies of Fe-based conductor SmFeAsO0.85. This can be explained by the influence of paramagetism in HoBa2Cu3O7−δ.
Quadratic temperature dependence of magnetoresistivity of pure tungsten single crystals under static skin effect
Authors: Marchenkov V. V.
Published: January 2012

Transverse magnetoresistivity of tungsten single crystals with residual resistivity ratio of ρ293K/ρ4.2K ≈75 000 was measured in the temperature range of 2–75 K and in magnetic fields up to 80 kOe. At low temperatures in these “dimensional” crystals a quadratic temperature dependence of magnetoresistivity ρxx is found. It is shown that the observed quadratic dependence ρxx(T) emerges under static skin effect and is a manifestation of the interference scattering mechanism “electron – phonon – surface,” similar to what happens in pure metals without a magnetic field. A qualitative explanation of the observed dependence is proposed here.
Valentin Peschansky and the puzzles of magnetotransport
Authors: Pudalov V. M.
Published: January 2012

Since the 1950’s, the Kharkov school of theoretical physics has been a world leader in the theory of metals. In particular, the research by V. G. Peschansky for many years has focused on the relationship between the magnetic field dependence of components of the resistivity and the electron energy spectrum. Peschansky developed an elegant theory of magnetoresistance that took surface scattering of electrons into account. The physics of bulk 3D metals was almost exhausted by the end of 1970’s and Peschansky extended his research to low-dimensional electron systems. Throughout his scientific life, V. G. Peschansky has advocated the idea that magnetoresistance is a powerful tool for exploring the rich physics of electron systems. The many experimental and theoretical studies of magnetoresistance behavior in various systems, from simple to the most complex, have, by now, confirmed the fruitfulness of this idea.
Quantum entanglement between electronic and vibrational degrees of freedom in molecules
Authors: McKemmish Laura K. , McKenzie Ross H. , Hush Noel S. , Reimers Jeffrey R.
Published: January 2012

We consider the quantum entanglement of the electronic and vibrational degrees of freedom in molecules with tendencies towards double welled potentials. In these bipartite systems, the von Neumann entropy of the reduced density matrix is used to quantify the electron-vibration entanglement for the lowest two vibronic wavefunctions obtained from a model Hamiltonian based on coupled harmonic diabatic potential-energy surfaces. Significant entanglement is found only in the region in which the ground vibronic state contains a density profile that is bimodal (i.e., contains two separate local maxima). However, in this region two distinct types of density and entanglement profiles are found: one type arises purely from the degeneracy of energy levels in the two potential wells and is destroyed by slight asymmetry, while the other arises through strong interactions between the diabatic levels of each well and is relatively insensitive to asymmetry. These two distinct types are termed fragile degeneracy-induced entanglement and persistent entanglement, respectively. Six classic molecular systems describable by two diabatic states are considered: ammonia, benzene, BNB, pyridine excited triplet states, the Creutz-Taube ion, and the radical cation of the “special pair” of chlorophylls involved in photosynthesis. These chemically diverse systems are all treated using the same general formalism and the nature of the entanglement that they embody is elucidated.
Nitrogen nucleation in a cryogenic supersonic nozzle
Authors: Bhabhe Ashutosh , Wyslouzil Barbara
Published: January 2012

We follow the vapor–liquid phase transition of N2 in a cryogenic supersonic nozzle apparatus using static pressure measurements. Under our operating conditions, condensation always occurs well below the triple point. Mean field kinetic nucleation theory (MKNT) does a better job of predicting the conditions corresponding to the estimated maximum nucleation rates, Jmax = 1017±1 cm−3 s−1, than two variants of classical nucleation theory. Combining the current results with the nucleation pulse chamber measurements of Iland et al. [J. Chem. Phys. 130, 114508–1 (2009)], we use nucleation theorems to estimate the critical cluster properties. Both the theories overestimate the size of the critical cluster, but MKNT does a good job of estimating the excess internal energy of the clusters.
The impact of heavy Ga doping on superconductivity in germanium
Authors: Skrotzki R. , Herrmannsdörfer T. , Heera V. , Fiedler J. , Mücklich A. , Helm M. , Wosnitza J.
Published: January 2012

We report new experimental results on how superconductivity in gallium-doped germanium (Ge:Ga) is influenced by hole concentration and microstructure. Ion implantation and subsequent flash-lamp annealing at various temperatures have been utilized to prepare highly p-doped thin films consisting of nanocrystalline and epitaxially grown sublayers with Ga-peak concentrations of up to 8 at. %. Successive structural investigations were carried out by means of Rutherford-backscattering spectrometry in combination with ion channeling, secondary-ion-mass spectrometry, and high-resolution cross-sectional transmission electron microscopy. Hole densities of 1.8·1020 to 5.3·1020 cm−3 (0.4 to 1.2 at. %) were estimated via Hall-effect measurements revealing that only a fraction of the incorporated gallium has been activated electrically to generate free charge carriers. The coincidence of a sufficiently high hole and Ga concentration is required for the formation of a superconducting condensate. Our data reflect a critical hole concentration of around 0.4 at. %. Higher concentrations lead to an increase of Tc from 0.24 to 0.43 K as characterized by electrical-transport measurements. A short mean-free path indicates superconductivity in the dirty limit. In addition, small critical-current densities of max. 20 kA/m2 point to a large impact of the microstructure.
Surfactant free graphene nanosheets based nanofluids by in-situ reduction of alkaline graphite oxide suspensions
Authors: Jyothirmayee Aravind S. S. , Ramaprabhu S.
Published: January 2012

Herein we report an entirely different route for the synthesis of graphene nanosheets (GNs) based nanofluids without surfactant or harsh chemical treatments, by reducing the alkaline graphite oxide suspension in ethylene glycol (EG) and de-ionized (DI) water based fluids by a simple thermal treatment. The thermal conductivity measurement after the reduction shows about 6.5 and 13.6% enhancements at 25 °C for the 0.14% volume fraction of GN in EG and DI water, respectively, which is ascribed to the high aspect ratio of the GNs. In addition, a large enhancement in the electrical conductivity of EG and DI water based reduced nanofluids is observed. This interesting result is attributed to the high electrical conductivity of reduced graphene nanosheets suspensions.
On electric fields created by quantized vortices
Authors: Rukin A. S. , Shevchenko S. I.
Published: January 2012

It is shown that in a magnetic field the quantized vortices in a superfluid acquire a real quantized electric charge concentrated in the vortex core. This charge is compensated by an opposite surface charge, located at macroscopic distance from the vortex axis. It is found that polarization caused by the vortex velocity field does not give rise to electric fields outside an infinite cylinder. The vortex-created electric fields can be observed only near the cylinder end surfaces, which must be covered by dielectric covers in order to prevent leakage of the superfluid. The influence of cover properties on the vortex-created potential is studied here. The potentials created by vortices on point and ring electrodes are calculated.
Effect of pressure on magnetic properties of the fluctuating-valence system Ce(Ni1−xCux)5
Authors: Grechnev G. E. , Logosha A. V. , Panfilov A. S. , Svechkarev I. V. , Musil O. , Svoboda P.
Published: January 2012

The magnetic susceptibility χ of isostructural Ce(Ni1−xCux)5 alloys (0 ≤ x ≤ 0.9) is studied as a function of hydrostatic pressure up to 2 kbar for fixed temperatures of 77.3 and 300 K. The pronounced effect of pressure on the susceptibility is negative in sign and depends nonmonotonically on the Cu content, with a sharp maximum at x ∼ 0.4. The experimental results are discussed in terms of a valence instability of Ce ions in these alloys. The major contributions to χ and their volume dependences are calculated ab initio in a local spin density approximation for the reference compound CeNi5, and appear to be in close agreement with experimental data.