bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Arctic clouds between European Center for Medium‐Range Weather Forecasts simulations and Atmospheric Radiation Measurement Climate Research Facility long‐term observations at the North Slope of Alaska Barrow site
Authors: Zhao Ming , Wang Zhien
Published: December 2010

This study evaluated the European Center for Medium‐Range Weather Forecasts (ECMWF) model‐simulated clouds and boundary layer (BL) properties based upon Atmospheric Radiation Measurement Climate Research Facility observations at the North Slope of Alaska site during 1999–2007. The ECMWF model‐simulated near‐surface humidity had seasonal dependent biases as large as 20%, while also experiencing difficulty representing BL temperature inversion height and strength during the transition seasons. Although the ECMWF model captured the seasonal variation of surface heat fluxes, it had sensible heat flux biases over 20 W m−2 in most of the cold months. Furthermore, even though the model captured the general seasonal variations of low‐level cloud fraction (LCF) and liquid water path (LWP), it still overestimated the LCF by 20% or more and underestimated the LWP over 50% in the cold season. On average, the ECMWF model underestimated LWP by ∼30 g m−2 but more accurately predicted ice water path for BL clouds. For BL mixed‐phase clouds, the model predicted water‐ice mass partition was significantly lower than the observations, largely due to the temperature dependence of water‐ice mass partition used in the model. The ECMWF model captured the general response of cloud fraction and LWP on large‐scale vertical motion changes but overpredicted the magnitude of the difference, especially for LWP. The new cloud and BL schemes of the ECMWF model that were implemented after 2003 only resulted in minor improvements in BL cloud simulations in summer. These results indicate that significant improvements in cold season BL and mixed‐phase cloud processes in the model are needed.
Comparing radiosonde and COSMIC atmospheric profile data to quantify differences among radiosonde types and the effects of imperfect collocation on comparison statistics
Authors: Sun Bomin , Reale Anthony , Seidel Dian J. , Hunt Douglas C.
Published: December 2010

Collocated global atmospheric temperature, humidity, and refractivity profiles from radiosondes and from Constellation Observing System for Meteorology, Ionosphere, and Climate (COSMIC) radio occultation data for April 2008 to October 2009 are compared for two purposes. The first is to quantify the error characteristics of 12 radiosonde types flown in the global operational network, as a function of height and for both day and nighttime observations, for each of the three variables. The second is to determine the effects of imperfect temporal and spatial collocation on the radiosonde‐COSMIC differences, for application to the general problem of satellite calibration and validation using in situ sounding data. Statistical analyses of the comparisons reveal differences among radiosonde types in refractivity, relative humidity, and radiation‐corrected temperature data. Most of the radiosonde types show a dry bias, particularly in the upper troposphere, with the bias in daytime drier than in nighttime. Weather‐scale variability, introduced by collocation time and distance mismatch, affects the comparison of radiosonde and COSMIC data by increasing the standard deviation errors, which are generally proportional to the size of the time and distance mismatch within the collocation window of 6 h and 250 km considered. Globally, in the troposphere (850–200 hPa), the collocation mismatch impacts on the comparison standard deviation errors for temperature are 0.35 K per 3 h and 0.42 K per 100 km and, for relative humidity, are 3.3% per 3 h and 3.1% per 100 km, indicating an approximate equivalence of 3 h to 100 km in terms of mismatch impact.
Numerical ecology validates a biogeographical distribution and gender-based effect on mucosa-associated bacteria along the human colon
Authors: de Cárcer Daniel Aguirre , Cuív Páraic Ó , Wang Tingting , Kang Seungha , Worthley Daniel , Whitehall Vicki , Gordon Iain , McSweeney Chris , Leggett Barbara , Morrison Mark
Published: December 2010

We applied constrained ordination numerical ecology methods to data produced with a human intestinal tract-specific phylogenetic microarray (the Aus-HIT Chip) to examine the microbial diversity associated with matched biopsy tissue samples taken from the caecum, transverse colon, sigmoid colon and rectum of 10 healthy patients. Consistent with previous studies, the profiles revealed a marked intersubject variability; however, the numerical ecology methods of analysis allowed the subtraction of the subject effect from the data and revealed, for the first time, evidence of a longitudinal gradient for specific microbes along the colorectum. In particular, probes targeting Streptococcus and Enterococcus spp. produced strongest signals with caecal and transverse colon samples, with a gradual decline through to the rectum. Conversely, the analyses suggest that several members of the Enterobacteriaceae increase in relative abundance towards the rectum. These collective differences were substantiated by the multivariate analysis of quantitative PCR data. We were also able to identify differences in the microarray profiles, especially for the streptococci and Faecalibacterium prausnitzii, on the basis of gender. The results derived by these multivariate analyses are biologically intuitive and suggest that the biogeography of the colonic mucosa can be monitored for changes through cross-sectional and/or inception cohort studies.
Abundances and potential activities of nitrogen cycling microbial communities along a chronosequence of a glacier forefield
Authors: Brankatschk Robert , Töwe Stefanie , Kleineidam Kristina , Schloter Michael , Zeyer Josef
Published: December 2010

Glacier forefields are ideal ecosystems to study the development of nutrient cycles as well as single turnover processes during soil development. In this study, we examined the ecology of the microbial nitrogen (N) cycle in bulk soil samples from a chronosequence of the Damma glacier, Switzerland. Major processes of the N cycle were reconstructed on the genetic as well as the potential enzyme activity level at sites of the chronosequence that have been ice-free for 10, 50, 70, 120 and 2000 years. In our study, we focused on N fixation, mineralization (chitinolysis and proteolysis), nitrification and denitrification. Our results suggest that mineralization, mainly the decomposition of deposited organic material, was the main driver for N turnover in initial soils, that is, ice-free for 10 years. Transient soils being ice-free for 50 and 70 years were characterized by a high abundance of N fixing microorganisms. In developed soils, ice-free for 120 and 2000 years, significant rates of nitrification and denitrification were measured. Surprisingly, copy numbers of the respective functional genes encoding the corresponding enzymes were already high in the initial phase of soil development. This clearly indicates that the genetic potential is not the driver for certain functional traits in the initial phase of soil formation but rather a well-balanced expression of the respective genes coding for selected functions.
Bioinformatics analysis of homologies between pathogen antigens, autoantigens and the CFTR cystic fibrosis protein: A role for immunoadsorption therapy?
Authors: Carter Christopher
Published: December 2010

The cystic fibrosis CFTR chloride channel is involved in pathogen entry into epithelial cells, and provides the glutathione and hypochlorous acid necessary for bactericidal and viricidal actions. CFTR mutations block these effects, diminishing pathogen defence and allowing pathogen accumulation in the extracellular space, where antibody encounter is likely. The pathogen antigens observed in cystic fibrosis (including P. Aeruginosa, S.Aureus and S.Maltophilia proteins) are homologous to the autoantigens reported in cystic fibrosis and all are homologous to the CFTR protein itself. Antibodies to pathogens and autoantigens may also target the CFTR protein, acting as antagonists, further compromising its function. The tripartite relationship between pathogen antigens, autoantigens and the CFTR protein creates a feed forward cycle, diminishing the function of the CFTR protein and increasing the probability of pathogen accumulation and further antibody encounters at every turn. Kegg pathway analysis of the CFTR/autoantigen interactome indicates that the CFTR protein is also involved in pathogen entry pathways, diabetes and pancreatic and gastric acid secretion pathways, in pathways related to cardiac myopathy, and in the gonadotrophin signalling network, all which are relevant to cystic fibrosis. Interruption of this cycle by antigen and antibody adsorption, and possibly by immunosuppressant therapy may perhaps be of clinical benefit in cystic fibrosis.
Paternal Contribution to Small for Gestational Age Babies: A Multicenter Prospective Study
Authors: McCowan Lesley ME , North Robyn A. , Kho Ee Min , Black Michael A. , Chan Eliza HY. , Dekker Gustaaf A. , Poston Lucilla , Taylor Rennae S. , Roberts Claire T.
Published: December 2010

Our aims were to investigate whether men who fathered small for gestational age (SGA) infants themselves had lower birthweight, were more likely to be obese, have central adiposity and elevated blood pressure in adult life compared with men who fathered non‐SGA infants. A total of 2,002 couples participating in the Screening for Pregnancy Endpoints (SCOPE) study were enrolled in early pregnancy and pregnancy outcome data collected prospectively. SGA was defined as birthweight <10th customized centile, obesity as BMI ≥30 kg/m2, central adiposity as waist circumference >102 cm. Logistic regression was used to compare rates of obesity, and central adiposity between men who fathered SGA infants compared with those with non‐SGA infants and the final model was adjusted for maternal and paternal confounders. The men who fathered an SGA infant (209 (10.4%)) themselves had lower mean birthweight (3,291 (530) g vs. 3,472 (584) g, P < 0.0001), were more likely to be obese (50 (24.8%) vs. 321 (18.3%), adjusted odds ratio (OR) 1.50, 95% confidence interval 1.05–2.16, adjusted for maternal and paternal factors) and to have central adiposity (52 (25.1%) vs. 341 (19.2%), adjusted OR 1.53, 95% confidence interval 1.06–2.20) compared with men who fathered a non‐SGA infant. Elevated paternal blood pressure was not associated with SGA. In conclusion, we report a novel relationship between paternal obesity/central adiposity and birth of an SGA infant, which appears to be independent of maternal factors associated with fetal growth restriction.
The Beneficial Effects α‐Cyclodextrin on Blood Lipids and Weight Loss in Healthy Humans
Authors: Comerford Kevin B. , Artiss Joseph D. , Jen K.‐L. Catherine , Karakas Sidika E.
Published: December 2010

α‐Cyclodextrin (α‐CD) is a soluble fiber derived from corn. It has previously been reported that early intervention with Mirafit fbcx, a trademarked name for α‐CD, has beneficial effects on weight management in obese individuals with type 2 diabetes, and that it preferentially reduces blood levels of saturated and trans fats in the LDL receptor knockout mice. The current investigation involves overweight but not obese nondiabetic individuals and was intended to confirm the effects of α‐CD on both weight management and improving blood lipid levels. Forty‐one healthy adults (age: 41.4 ± 13.6 years) participated in this 2‐month, double‐blinded, crossover study. In 28 compliant participants (8 males and 20 females), when the active phase was compared to the control phase, there were significant decreases in body weight (−0.4 ± 0.2 kg, P < 0.05), serum total cholesterol (mean ± s.e.m., −0.295 ± 0.10 mmol/l, 5.3%, P < 0.02) and low‐density lipoprotein (LDL) cholesterol (−0.23 ± 0.11 mmol/l, −6.7%, P < 0.05). Apolipoprotein B (Apo B) (−0.0404 ± 0.02 g/l, −5.6%, P = 0.06) and insulin levels also decreased by 9.5% (−0.16 ± 0.08 pmol/l, P = 0.06) while blood glucose and leptin levels did not change. These results suggest that α‐CD exerts its beneficial health effects on body weight and blood lipid profile in healthy nonobese individuals, as previously reported in obese individuals with type 2 diabetes.
High Fructose Diets Increase 11β‐Hydroxysteroid Dehydrogenase Type 1 in Liver and Visceral Adipose in Rats Within 24‐h Exposure
Authors: London Edra , Castonguay Thomas W.
Published: December 2010

The increased prevalence of overweight and obesity in the United States during the past three decades coincides with a trend of increased sugar intake, especially fructose, leading to speculation that the two trends may be linked. The enzyme 11β‐hydroxysteroid dehydrogenase type 1 (11β‐HSD1), that regulates intracellular tissue‐specific glucocorticoid levels, is increased in adipose and suppressed in liver of obese humans and animals. Hexose‐6‐phosphate dehydrogenase (H6PDH) is colocalized with 11β‐HSD1 and generates nicotinamide adenosine dinucleotide phosphate, the required cofactor for 11β‐HSD1 reductase activity that converts inert glucocorticoid metabolite into active hormone. We examined the acute effects of ad lib access to 16% solutions of sucrose, fructose, or glucose and chow and water. Diets high in fructose, but not glucose or sucrose increased 11β‐HSD1 mRNA within 24 h in liver and adipose by greater than two‐ and threefold, respectively (P ≤ 0.05). After 1 week, hepatic 11β‐HSD1 mRNA and protein were suppressed by >60% in all sugar‐fed groups, a phenomenon not previously reported in the absence of obesity. Sucrose‐ and fructose‐fed rats had higher plasma triglycerides than did control or glucose‐fed rats at both 24 h and 1 week (P ≤ 0.02), consistent with previously reported effects of fructose on lipid metabolism. We conclude that high‐sugar diets initiate glucocorticoid dysregulation associated with obesity prior to the onset of phenotypic changes, and that high fructose diets specifically induce changes in 11β‐HSD1 within 24‐h exposure.
Family Functioning and Obesity Risk Behaviors: Implications for Early Obesity Intervention
Authors: Li Wen Ming , Simpson Judy M. , Baur Louise A. , Rissel Chris , Flood Victoria M.
Published: December 2010

Family functioning is found to be associated with overweight and obesity in childhood, but its association with maternal obesity risk behaviors is not clear. This study aimed to investigate whether family functioning is associated with maternal obesity risk behaviors and to inform the development of early obesity interventions. A total of 408 first‐time mothers at 24–34 weeks of pregnancy were included in the study. They participated in the Healthy Beginnings Trial (HBT) conducted in southwest Sydney, Australia in 2008. An analysis of cross‐sectional baseline data was conducted using ordinal logistic regression modeling. Key measures were assessed using the McMaster Family Assessment Device, and self‐reported obesity risk behaviors including excessive consumption of soft drinks, fast food, and excessive small screen time. The study found that 30% of the study population had a family functioning score ≥2, indicating unhealthy family functioning. About one‐third (36%) of the mothers had more than one obesity risk behavior. Mothers with a family functioning score ≥2 were more likely to have more than one obesity risk behavior (47% vs. 32%, P < 0.05) than mothers with a lower score. The proportion of mothers with a family functioning score ≥2 increased from 22% to 29% to 39% as the number of maternal obesity risk behaviors increased from 0 to 1 to 2 or more, giving an adjusted proportional odds ratio (AOR) of 2.0 (95% confidence interval (CI) 1.3–3.0, P = 0.001). Family functioning is independently associated with the number of maternal obesity risk behaviors after allowing for the effects of maternal age and education. Overweight and obesity interventions should consider addressing family functioning.
Stress and Abdominal Fat: Preliminary Evidence of Moderation by the Cortisol Awakening Response in Hispanic Peripubertal Girls
Authors: Donoho Carrie J. , Weigensberg Marc J. , Emken B. Adar , Hsu Ja‐Wen , Spruijt‐Metz Donna
Published: December 2010

Stress and the cortisol awakening response (CAR) have been independently linked to increases in abdominal fat depots. This cross‐sectional study examined the CAR as a moderator of the association between stress, visceral adipose tissue (VAT), and subcutaneous abdominal adipose tissue (SAT) in a sample (N= 23) of female peripubertal Hispanic girls aged from 8 to 11. The study included: (i) monitored salivary cortisol collection, (ii) VAT and SAT obtained by multislice magnetic resonance imaging, and (iii) a stressful life events checklist with four domain‐specific subscales: peer, family, personal, and school. Regression analysis indicated an interaction of school‐related life events and CAR on VAT and SAT, with greater numbers of school‐related events being related to greater VAT and SAT for girls with high CAR, but no association with VAT or SAT for girls with low CAR. Similar to job stress in adults, school‐related stress in children may contribute to central adiposity, especially for girls with high CAR.
The Impact of Sudden Hearing Loss Secondary to Heroin Overdose on Fitting Outcomes
Authors: Nair Erika L. , Cienkowski Kathleen M. , Michaelides Elias
Published: December 2010

Purpose

There are few cases in the literature that report the auditory effects of heroin overdose. Follow-up and rehabilitation in these cases are unreported. In the case reported here, a 29-year-old woman presented with sudden bilateral sensorineural hearing loss subsequent to reported heroin overdose. She was fitted with binaural amplification and monitored over 3 months.

Method

The Hearing Handicap Inventory for Adults—Screening version (HHIA–S), Expected Consequences of Hearing Aid Ownership (ECHO), and Satisfaction With Amplification in Daily Life (SADL) were administered after hearing aid fitting. These measures assessed the patient’s perceptions of handicap as well as her expectations of and satisfaction with amplification.

Results

The patient’s responses on the HHIA–S were higher than normative values at the time of the incident, indicating perceptions of greater handicap. Her perceptions of handicap decreased after having been fit with hearing aids. Responses on the SADL and ECHO were within normative values.

Conclusion

This case provides a framework for managing the rehabilitation of this population. Audiologists need to understand their role in the careful monitoring of hearing rehabilitation and how they may help in determining complaints that may be hearing- or device-related versus those associated with the psychological symptoms experienced during the withdrawal period.
Do Group Audiologic Rehabilitation Activities Influence Psychosocial Outcomes?
Authors: Preminger Jill E. , Yoo Jae K.
Published: December 2010

Purpose

To attempt to determine whether group audiologic rehabilitation (AR) content affected psychosocial outcomes.

Method

A randomized controlled trial with at least 17 participants per group was completed. The 3 treatment groups included a communication strategies training group, a communication strategies training plus psychosocial exercise group, and an informational lecture plus psychosocial exercise group. Evaluations were conducted preclass, postclass, and 6-months postclass; they included hearing loss–related and generic quality of life scales, and a class evaluation form.

Results

All treatment groups demonstrated short- and long-term improvement on the hearing loss–related quality of life scale. Minimal differences were measured across treatment groups. A significant difference was observed between the lecture plus psychosocial exercise group and the communication strategies training group for 1 hearing loss–related quality of life subscale. Better outcomes were measured for the 2 groups with psychosocial exercises versus the communication strategies training group on 1 generic quality of life subscale. The results for the class evaluation did not discriminate among the treatment groups.

Conclusions

Class content had only a minimal influence on treatment outcomes. Recommended AR class content includes a mix of interventions including information, training, and psychosocial exercises.
Animated Toys Versus Video Reinforcement in 16–24-Month-Old Children in a Clinical Setting
Authors: Karzon Roanne K. , Banerjee Pia
Published: December 2010

Purpose

To compare the clinical efficacy of visual reinforcement audiometry (VRA) with animated toy animal reinforcement (AVRA) to the efficacy of VRA with video reinforcement (VVRA) in children age 16 to 24 months in a fast-paced medical practice.

Method

The 145 participants (age 16 to 24 months) were referred by either their primary care physician or an otolaryngology practitioner (physician or nurse practitioner) for audiologic assessment. Children were assigned in a counterbalanced manner to either the AVRA or VVRA group.

Results

Significantly more threshold estimates were obtained with AVRA (
M
= 5.52) than with VVRA (
M
= 3.47). There were no significant differences in performance based on age, hearing status, or gender.

Conclusions

Number and relative strength of the visual reinforcers used are posited as the main reasons for the disparate outcomes. Clinical practices that test large numbers of children with VRA would be well-served to have both AVRA and VVRA available to meet the needs of individual patients.
“This Stuff Is Great but How Can I Use It in My Therapy Sessions?” Developing Resources To Facilitate Interactive Learning and Best Practice
Authors: Wingard Todd , Blosser Jean
Published: December 2010

SLPs are very diligent about participating in continuing education activities to build their expertise and skills. Unfortunately, too often their intentions to share and use the material from such activities are side-lined by hectic schedules and competing priorities. With these challenges in mind, Progressus Therapy's clinical coordinators and clinicians undertook a project to establish an efficient method for capturing and sharing valuable evidence-based service delivery recommendations and strategies. This article provides information about the results of the project: Progressus Best Practice Resource Modules.
Never Assume! Mentoring the Connections Between Theory and Practice
Authors: Parmenter Jill , McGraw Paula
Published: December 2010

Mentoring is one of the most important services experienced speech-language pathologists can provide to the profession of speech-language pathology. The mentoring we provide today will impact the future of the profession. This article will examine the roles and responsibilities of a mentoring speech-language pathologist, considering the specific needs of a Clinical Fellow (CF) as well as the mentoring needed for professionals throughout their careers.
Regulating the Use of Support Personnel in Schools
Authors: Ross Sharon , Harding Marcia
Published: December 2010

Rules and regulations governing the use of support personnel in Arkansas were approved in 1996. These regulations allow school districts to employ support personnel, assistants or aides, to assist master's level speech-language pathologists (SLPs) with clerical and clinical tasks. School district personnel must develop proposals, receive approval, and participate in training before the support personnel can be used in the delivery of speech-language services. The supervising SLPs manage the caseload, provide direct services, and supervise the support personnel. This model of service delivery has been used effectively in Arkansas schools to enhance services provided by the SLPs. Support personnel are employed primarily in the rural parts of the state where there is a shortage of SLPs.
Detection of x-ray emission in a nanosecond discharge in air at atmospheric pressure
Authors: Zhang Cheng , Shao Tao , Yu Yang , Niu Zheng , Yan Ping , Zhou Yuanxiang
Published: December 2010

Measurement of x-ray emission is an important parameter to investigate runaway behavior of fast electrons produced in nanosecond-pulse gas discharge. An online detection system of x rays is described in this paper, and the system consists of an x-ray detector with NaI (Tl) scintillator and photomultiplier tube, and an integrated multichannel analyzer. The system is responsible for detecting x-ray emission signal, processing the detected signals, and scaling the energy distribution. The calibration results show that every channel of the detection system represents a given x-ray energy and various x rays can be divided into different energy ranges between 10 and 130 keV. For a repetitive nanosecond-pulse breakdown between highly nonuniform gaps in open air, an energy distribution is obtained using the online detection system. It shows that the x-ray emission is a continuous spectrum and the x rays of above 60 keV dominate in the detected energy distribution.
Higher charges and regularized quantum trace identities in su(1,1) Landau–Lifshitz model
Authors: Melikyan A. , Pinzul A. , Weber G.
Published: December 2010

We solve the operator ordering problem for the quantum continuous integrable su(1,1) Landau–Lifshitz model, and give a prescription to obtain the quantum trace identities, and the spectrum for the higher-order local charges. We also show that this method, based on operator regularization and renormalization, which guarantees quantum integrability, as well as the construction of self-adjoint extensions, can be used as an alternative to the discretization procedure, and unlike the latter, is based only on integrable representations.
Effect of Zn on the adsorption of CO on Pd(111)
Authors: Huang Yucheng , Ding Weiping , Chen Zhao-Xu
Published: December 2010

Introduction of a second metal can greatly modify the surface reactivity of a host metal. Recently Jeroro and Vohs found that Pd(111) deposited with 0.03–0.06 monolayer of Zn might possess unique activity to methanol steam reforming reaction. To investigate the distribution of the deposited Zn, we examined the adsorption of CO on two types of model systems. In the first model, Zn is in the top-layer of Pd(111) only, while in the second model Zn is placed in the subsurface exclusively. It is found that Zn atoms in the topmost layer show negligible effect on CO adsorption especially at hollow sites, whereas the second layer Zn atoms affect significantly the interaction of CO with the substrate. It is revealed that the negligible influence of the first layer Zn on CO adsorption is due to the offsetting of the ligand effect by the strain effect. On the other hand, the ligand effect dominates the CO adsorption in the second model where the strain effect is insignificant. It is demonstrated that the d-band centers correlate well with the binding energies of the second model, whereas no such good correlation exists for the first model. Our results show that the subsurface plays a more important role and the observed dramatic modification of surface reactivity of Pd(111) deposited with 0.03–0.06 ML Zn is most likely originated from the subsurface Zn atoms, if the coverage is not underestimated and the deposited Zn atoms are distributed uniformly within a layer.
Nanocrystalline titanium dioxide films: Influence of ambient conditions on surface- and volume-related photoluminescence
Authors: Preclíková Jana , Galář Pavel , Trojánek František , Daniš Stanislav , Rezek Bohuslav , Gregora Ivan , Němcová Yvonne , Malý Petr
Published: December 2010

We report on systematic study of photoluminescence properties of nanocrystalline titanium dioxide films consisting of predominantly anatase nanoparticles with diameters larger than 13 nm. We measured photoluminescence under two selected excitation wavelengths (325 nm/442 nm, i.e., above/below band gap excitation), under different values of ambient air pressure (5–105 Pa), and in the temperature interval 10–300 K. On basis of our results, we are able to distinguish two different processes leading to photoluminescence: the exciton recombination and the recombination of carriers in the energy states related to the surface of nanocrystals. We propose microscopic models describing well the effects of temperature and ambient conditions on photoluminescence of nanocrystalline titanium dioxide films.
Modified Landau levels, damped harmonic oscillator, and two-dimensional pseudo-bosons
Authors: Ali S. Twareque , Bagarello F. , Gazeau Jean Pierre
Published: December 2010

In a series of recent papers, one of us has analyzed in some details a class of elementary excitations called pseudo-bosons. They arise from a special deformation of the canonical commutation relation [a, a†] = 11, which is replaced by [a, b] = 11, with b not necessarily equal to a†. Here, after a two-dimensional extension of the general framework, we apply the theory to a generalized version of the two-dimensional Hamiltonian describing Landau levels. Moreover, for this system, we discuss coherent states and we deduce a resolution of the identity. We also consider a different class of examples arising from a classical system, i.e., a damped harmonic oscillator.
Photoluminescent properties of cubic K2MnF6 particles synthesized in metal immersed HF/KMnO4 solutions
Authors: Kasa Ryota , Arai Yusuke , Takahashi Toru , Adachi Sadao
Published: December 2010

A pink K2MnF5⋅H2O precipitate is obtained by etching Mg, Fe, Ni, Cu, Zn, or In in an aqueous HF/KMnO4 solution. The pink K2MnF5⋅H2O precipitate typically contains K2MnF6 particles, which exhibit photoluminescence in the red spectral region under blue or UV excitation. The observed red emission is ascribed to the Mn4+ (3d3) ions in Mn(IV)F62− octahedra promoted by the activation of local vibronic modes. The absence of a strong zero-phonon line emission suggests that the synthesized K2MnF6 particles have a cubic symmetry (space group=Fm3m). The energy states and crystal field parameter of the 3d3 (Mn4+) electrons in the cubic K2MnF6 lattice are also determined.
Strong perpendicular magnetic anisotropy in an MgO/CoFeB/Pd unit structure with a thick CoFeB layer
Authors: Jung J. H. , Lim S. H. , Lee S. R.
Published: December 2010

A strong perpendicular magnetic anisotropy (PMA) is formed in an MgO/CoFeB/Pd unit structure for an MgO-based magnetic tunnel junction. The most important factors for a strong PMA are the composition and the thickness of the CoFeB layer. A strong PMA is observed for the samples fabricated using the CoFeB target with a high Co/Fe ratio and annealed at 300 °C for 1 or 2 h. The PMA is formed up to a CoFeB layer thickness as thick as 2.5 nm, although the strongest PMA, with an out-of-plane coercivity of 1068 Oe and a PMA energy density of 2.7×106 erg/cc, is seen at a CoFeB thickness of 2.0 nm. The systematic study indicates that the PMA is attributed not to the interface effects but rather to the bulk effect of forming a Pd-rich, Co–Pd alloy, as confirmed by x-ray photoelectron spectroscopy depth profile and x-ray diffraction experiments. The thick CoFeB layer is expected to reduce the template effect from the Pd layer during the annealing, and therefore increase the tunneling magnetoresistance of the MgO-based magnetic tunnel junction.
Substrate-modified ferrimagnetism in MnGa films
Authors: Feng Wuwei , Van Thiet Duong , Dung Dang Duc , Shin Yooleemi , Cho Sunglae
Published: December 2010

We report the substrate-modified magnetic properties of the CuAu type-I (L10) structure of MnxGa (1.2<x<1.5) films. The magnetic properties of the MnGa films differed greatly due to the influence of the substrate. The MnGa film is a hard ferrimagnet when grown on GaSb (111), becomes a soft ferrimagnet when grown on Al2O3 (0001), and exhibits an absence of a net magnetic moment when stabilized on a GaSb (100) substrate. This difference was attributed to the substrate, which forces MnGa film to be two-dimensionally stabilized in a different orientation and thus leads to the modified crystal symmetry and a change in the magnetic property. The results may be helpful for forming a comprehensive understanding of MnGa and for finding new applications in spintronic devices.
Interfaces and traps in pentacene field-effect transistor
Authors: Sangeeth C. S. Suchand , Stadler P. , Schaur S. , Sariciftci N. S. , Menon Reghu
Published: December 2010

The equivalent circuit parameters for a pentacene organic field-effect transistor are determined from low frequency impedance measurements in the dark as well as under light illumination. The source-drain channel impedance parameters are obtained from Bode plot analysis and the deviations at low frequency are mainly due to the contact impedance. The charge accumulation at organic semiconductor–metal interface and dielectric–semiconductor interface is monitored from the response to light as an additional parameter to find out the contributions arising from photovoltaic and photoconductive effects. The shift in threshold voltage is due to the accumulation of photogenerated carriers under source-drain electrodes and at dielectric–semiconductor interface, and also this dominates the carrier transport. The charge carrier trapping at various interfaces and in the semiconductor is estimated from the dc and ac impedance measurements under illumination.
Thermal nonlinear effects in hybrid optical microresonators
Authors: Choi Hong Seok , Armani Andrea M.
Published: December 2010

The inherent material properties of silica reduce the susceptibility of silica optical microcavities to many nonlinear phenomena, enabling the development of devices with improved stability. However, large nonlinear coefficients can be leveraged to create microcavities with additional functionality. Therefore, devices with controllable nonlinear behavior are of interest. In the present research, silica microcavities are coated with polystyrene or polymethylmethacrylate to form hybrid microresonators. Using these devices, the thermally induced nonlinear optical behavior is investigated. By precisely controlling the optical field overlap with the polymer film, an environmentally stable device, in which the resonant frequency is independent of the input power, is demonstrated.
Ion acceleration and cooling in gasless self-sputtering
Authors: Horwat David , Anders André
Published: December 2010

Copper plasma with hyperthermal directed velocity (8.8 eV) but very low temperature (0.6 eV) has been obtained using self-sputtering far above the runaway threshold. Ion energy distribution functions (IEDFs) were simultaneously measured at 34 locations. The IEDFs show the tail of the Thompson distribution near the magnetron target. They transform to shifted Maxwellians with the ions being accelerated and cooled. We deduce the existence of a highly asymmetric, pressure-driven potential hump which acts as a controlling “watershed” between the ion return flux and the expanding plasma.
Measurement of the attempt frequency in antiferromagnets
Authors: Vallejo-Fernandez G. , Aley N. P. , Chapman J. N. , O’Grady K.
Published: December 2010

The characteristic relaxation frequency of a granular antiferromagnet f0 in the Néel–Arrhenius expression has been calculated from a high resolution measurement of the time dependence of the median blocking temperature of a CoFe/IrMn exchange biased system. Calculations based on a granular model give f0=(2.1±0.4)×1012 s−1, three orders of magnitude greater than values commonly found in the literature.
Strain relaxation and phonon confinement in self-assembled InAsSb/InP (001) quantum dashes: Effect of deposition thickness and composition
Authors: Lei W. , Tan H. H. , Jagadish C. , Ren Q. J. , Lu J. , Chen Z. H.
Published: December 2010

This paper presents a study on the strain relaxation and phonon confinement effect in InAsSb/InP quantum dashes (QDashes). The phonon mode with a frequency between that of InAs-like longitudinal optical mode and that of InP transverse optical mode is determined to be originated from InAsSb QDashes. Despite the small height of the QDashes, their phonon frequency is found to be mainly determined by the strain relaxation in the dashes. With increasing InAsSb deposition thickness and Sb composition in InAsSb dashes, the phonon mode shows an upward shift of its frequency due to the increased compressive strain.
Observation of excited states of graphene on Ni(111) by secondary electron spectroscopy
Authors: Riccardi P. , Cupolillo A. , Pisarra M. , Sindona A. , Caputi L. S.
Published: December 2010

We use secondary electron spectroscopy to probe the excited states of graphene adsorbed on a Ni(111) surface. A fine structure directly related to the empty bands above the vacuum level of the sample is resolved in the spectra excited by electrons. Ion-induced spectra reveal a high energy feature that is consistent with electron promotion from valence to conduction band states, from which electrons emerge into vacuum.
Enhanced performance of inverted polymer solar cells with cathode interfacial tuning via water-soluble polyfluorenes
Authors: Na Seok-In , Kim Tae-Soo , Oh Seung-Hwan , Kim Junkyung , Kim Seok-Soon , Kim Dong-Yu
Published: December 2010

Enhanced performance of inverted polymer solar cells (PSCs) is demonstrated by indium tin oxide (ITO) interfacial tuning via a water-soluble polyfluorene (WPF-6-oxy-F). Kelvin probe studies and dark current-voltage curves demonstrated that the WPF-6-oxy-F layer reduces the ITO work-function because of the favorable interfacial dipole formed by the WPF-6-oxy-F interlayer, thereby enhancing the built-in potential and reducing the interface resistance. As a result, introduction of the WPF-6-oxy-F by simple solution processing into the inverted PSCs dramatically enhanced cell-performances. This approach could be very beneficial and an important step for the future development of all-solution-processed or roll-to-roll processed PSCs.
Flow regime transition at high capillary numbers in a microfluidic T-junction: Viscosity contrast and geometry effect
Authors: Gupta Amit , Kumar Ranganathan
Published: December 2010

Flow regimes obtained as a consequence of two immiscible fluids interacting at a T-junction are presented for transitional to high capillary numbers and different ratios of the continuous and dispersed phase flow rates and viscosities. Results are presented for the formation of micron-sized droplets using simulations performed based on a three-dimensional lattice Boltzmann method. The influence of viscosity and geometry of the device on the frequency and volume of droplets formed has been examined and the nondimensional drop size correlated with the capillary number and flow rate ratio. This work reveals two important and new physical features: (a) the transition zone separating droplet and jet flows narrows for high capillary numbers and (b) the critical flow rate ratio separating droplet and parallel flows increases as the dispersed to continuous channel width ratio increases, aspects which have been correlated using a simple relation for both transitions from the droplet-at-T-junction to droplet-in-channel and droplet-in-channel to parallel flow. In the droplet-at-T-junction regime, the droplet formation frequency was recorded as a function of the capillary number, flow rate ratio, and the channel width ratio as well. Results show that the transition to stable jets can be delayed and droplets can be formed even at very high flow rate ratios by significantly increasing the viscosity of the continuous phase.
Enhancing the electron mobility via delta-doping in SrTiO3
Authors: Kozuka Y. , Kim M. , Ohta H. , Hikita Y. , Bell C. , Hwang H. Y.
Published: December 2010

We fabricated high-mobility δ-doped structures in SrTiO3 thin films in order to investigate the low temperature electronic transport properties of confined carriers in this system. An enhancement of the electron mobility above the bulk value was observed as the doped layer thickness decreased. High-field Hall measurements revealed that this mobility enhancement originates from higher-mobility electrons in the undoped clean regions, which have quantum-mechanically broadened from the doped layer. Because of the absence of apparent lattice misfit between the layers, this structure is highly suitable for investigating two-dimensional electron gases in SrTiO3.
Epitaxial growth of a silicene sheet
Authors: Lalmi Boubekeur , Oughaddou Hamid , Enriquez Hanna , Kara Abdelkader , Vizzini Sébastien , Ealet Bénidicte , Aufray Bernard
Published: December 2010

Using atomic resolved scanning tunneling microscopy, we present here the experimental evidence of a silicene sheet (graphenelike structure) epitaxially grown on a close-packed silver surface [Ag(111)]. This has been achieved via direct condensation of a silicon atomic flux onto the single-crystal substrate in ultrahigh vacuum conditions. A highly ordered silicon structure, arranged within a honeycomb lattice, is synthesized and present two silicon sublattices occupying positions at different heights (0.02 nm) indicating possible sp2-sp3 hybridizations.
Utilising implementation science in building research and evaluation capacity in community health
Authors: Bamberg John , Perlesz Amaryll , McKenzie Peter , Read Sharon
Published: December 2010

It is becoming increasingly important for the community health sector to provide evidence of practice and program effectiveness. Unfortunately many community health centres do not have the capacity to provide such evidence and require the implementation of innovative changes within their organisation to develop their capacity to conduct research and evaluation. In this paper we present our project in which we utilised Donald Ely’s model to build research and evaluation capacity in a community health centre. We utilised a qualitative research method that incorporated a co-operative inquiry action research design. Qualitative research methods incorporated data from semi-structured interviews, observations and the recording of relevant meetings. The data were analysed by means of thematic analysis. We found that to successfully build research and evaluation capacity entails the application of a model that is capable of not only addressing significant issues in implementation but that can also identify the conditions within an organisation that are important to achieve change. Ely’s Conditions for Change model was most appropriate to implement the necessary changes.
Structural basis for the synthesis of nucleobase modified DNA by
Thermus aquaticus
DNA polymerase
Authors: Obeid Samra , Baccaro Anna , Welte Wolfram , Diederichs Kay , Marx Andreas
Published: December 2010

Numerous 2′-deoxynucleoside triphosphates (dNTPs) that are functionalized with spacious modifications such as dyes and affinity tags like biotin are substrates for DNA polymerases. They are widely employed in many cutting-edge technologies like advanced DNA sequencing approaches, microarrays, and single molecule techniques. Modifications attached to the nucleobase are accepted by many DNA polymerases, and thus, dNTPs bearing nucleobase modifications are predominantly employed. When pyrimidines are used the modifications are almost exclusively at the C5 position to avoid disturbing of Watson–Crick base pairing ability. However, the detailed molecular mechanism by which C5 modifications are processed by a DNA polymerase is poorly understood. Here, we present the first crystal structures of a DNA polymerase from
Thermus aquaticus
processing two C5 modified substrates that are accepted by the enzyme with different efficiencies. The structures were obtained as ternary complex of the enzyme bound to primer/template duplex with the respective modified dNTP in position poised for catalysis leading to incorporation. Thus, the study provides insights into the incorporation mechanism of the modified nucleotides elucidating how bulky modifications are accepted by the enzyme. The structures show a varied degree of perturbation of the enzyme substrate complexes depending on the nature of the modifications suggesting design principles for future developments of modified substrates for DNA polymerases.
ANK6, a mitochondrial ankyrin repeat protein, is required for male-female gamete recognition in
Arabidopsis thaliana
Authors: Yu Feng , Shi Jia , Zhou Jiye , Gu Jianing , Chen Qihui , Li Jian , Cheng Wei , Mao Dandan , Tian Lianfu , Buchanan Bob B. , Li Legong , Chen Liangbi , Li Dongping , Luan Sheng
Published: December 2010

Double fertilization in angiosperms involves several successive steps, including guidance and reception of the pollen tube and male-female gamete recognition. Each step entails extensive communication and interaction between two different reproductive cell or tissue types. Extensive research has focused on the pollen tube, namely, its interaction with the stigma and reception by maternal cells. Little is known, however, about the mechanism by which the gametes recognize each other and interact to form a zygote. We report that an ankyrin repeat protein (ANK6) is essential for fertilization, specifically for gamete recognition.
ANK6
(At5g61230) was highly expressed in the male and female gametophytes before and during but not after fertilization. Genetic analysis of a T-DNA insertional mutant suggested that loss of function of ANK6 results in embryonic lethality. Moreover, male-female gamete recognition was found to be impaired only when an
ank6
male gamete reached an
ank6
female gamete, thereby preventing formation of homozygous zygotes. ANK6 was localized to the mitochondria, where it interacted with SIG5, a transcription initiation factor previously found to be essential for fertility. These results show that ANK6 plays a central role in male-female gamete recognition, possibly by regulating mitochondrial gene expression.
Visible photoinduced hydrophilicity of V2O5–TiO2 nanoporous ceramic layers grown via micro-arc oxidation
Authors: Bayati M R , Molaei Roya
Published: December 2010

V2O5–TiO2 porous layers with a pore size of 50–400 nm were synthesized via a micro-arc oxidation process under different applied voltages. Morphological and topographical studies, performed by SEM and AFM techniques, revealed a nanoporous morphology with a rough surface where the pores' size as well as the surface roughness increased with voltage. In addition, our XRD and XPS results demonstrated that the layers consisted of anatase, rutile and vanadia phases. It was also found that V2O5 not only dispersed in the TiO2 matrix, but also doped into the crystalline lattice. Hydrophilicity of the synthesized layers was determined using a water contact angle apparatus. It was observed that the layer synthesized under the applied voltage of 450 V exhibited the highest hydrophilicity. Finally, a correlation between measured contact angles and MAO parameters was suggested with emphasis on the electrochemical foundations.