bluuebunny/crossref_metadata_2025 huggingface dataset:
Guideline for Adopting the Local Reaction Assumption for Porous Absorbers in Terms of Random Incidence Absorption Coefficients
Authors: Jeong Cheol-Ho
Published: August 2011

Room surfaces have been extensively modeled as locally reacting in room acoustic predictions although such modeling could yield significant errors under certain conditions. Therefore, this study aims to propose a guideline for adopting the local reaction assumption by comparing predicted
random incidence acoustical characteristics of typical building elements made of porous materials assuming extended and local reaction. For each surface reaction, five well-established wave propagation models, the Delany-Bazley, Miki, Beranek, Allard-Champoux, and Biot model, are employed.
Effects of the flow resistivity and the absorber thickness on the difference between the two surface reaction models are examined and discussed. For a porous absorber backed by a rigid surface, the assumption of local reaction always underestimates the random incidence absorption coefficient
and the local reaction models give errors of less than 10% if the thickness exceeds 120 mm for a flow resistivity of 5000 Nm–4s. As the flow resistivity doubles, a decrease in the required thickness by 25 mm is observed to achieve the same amount of error. For an absorber
backed by an air gap, the thickness ratio between the material and air cavity is important, since the thicker the cavity, the more extendedly reacting the absorber. If the absorber thickness is approximately 40% of the cavity depth, the local reaction models give errors below 10% even for
a low flow resistivity case.
Porous Materials to Support Bilayer Lipid Membranes for Ion Channel Biosensors
Authors: Phung Thai , Zhang Yanli , Dunlop James , Dalziel Julie E.
Published: August 2011

To identify materials suitable as membrane supports for ion channel biosensors, six filter materials of varying hydrophobicity, tortuosity, and thickness were examined for their ability to support bilayer lipid membranes as determined by electrical impedance spectroscopy. Bilayers supported by hydrophobic materials (PTFE, polycarbonate, nylon, and silanised silver) had optimal resistance (14–19 GΩ) and capacitance (0.8–1.6 μF) values whereas those with low hydrophobicity did not form BLMs (PVDF) or were short-lived (unsilanised silver). The ability of ion channels to function in BLMs was assessed using a method recently reported to improve the efficiency of proteoliposome incorporation into PTFE-supported bilayers. Voltage-gated sodium channel activation by veratridine and inhibition by saxitoxin showed activity for PTFE, nylon, and silanised silver, but not polycarbonate. Bilayers on thicker, more tortuous, and hydrophobic materials produced higher current levels. Bilayers that self-assembled on PTFE filters were the longest lived and produced the most channel activity using this method.
comparison between Cleavage Stage versus Blastocyst Stage Embryo Transfer in an Egyptian Cohort Undergoing in vitro Fertilization: A possible Role for Laser Assisted Hatching
Authors: Hendawy Sherif F. , Raafat TA
Published: August 2011

Background

Extended in vitro embryo culture and blastocyst transfer have emerged as essential components of the advanced reproductive technology armamentarium, permitting selection of more advanced embryos considered best suited for transfer.

Aim of study

The aim of this study was to compare between cleavage stage and blastocyst stage embryo transfer in patients undergoing intracytoplasmic sperm injection, and to assess the role of assisted hatching technique in patients undergoing blastocyst transfer.

Patients and methods

This study was carried out on two groups. Group I: 110 patients who underwent 120 cycles of intracytoplasmic sperm injection with day 2-3 embryo transfer—for unexplained infertility or male factor within the previous 3 years. Their data obtained retrospectively from medical records. Group II: 46 age matched infertile female patients undergoing 51 intracytoplasmic sperm injection cycles for similar causes. Patients in Group II were further subdivided into 2 equal subgroups; Group Ila (23 patients), which had laser assisted hatching and Group IIb (23 patients), which did not have assisted hatching. All patients had an infertility workup including basal hormonal profile, pelvic ultrasound, hysterosalpingogram and/or laparoscope and semen analysis of the patient's partner. All patients underwent controlled ovarian hyperstimulation: Using long protocol of ovulation induction. Laser assisted hatching was done for blastocysts of 23 patients.

Results

Comparison between both groups as regards the reproductive outcome showed a significant difference in pregnancy and implantation rates, both being higher in group II ( P < 0.05) Comparison between both subgroups as regards the reproductive outcome showed a highly significant difference in pregnancy and implantation rates, both being higher in Group IIa ( P < 0.01). There was also a significantly higher rate of multiple pregnancies among Group IIa ( P < 0.05).

Conclusion

Blastocyst transfer is a successful and improved alternative for patients with multiple failed in vitro fertilization attempts, associated with a significant increase in pregnancy and implantation rates. Furthermore, laser assisted hatching increases implantation and clinical pregnancy rates.
Listening and Communication Styles of Undergraduate Occupational Therapy Students: A Cross-Sectional Study
Authors: Brown Ted , Boyle Malcolm , Williams Brett , Molloy Andrew , McKenna Lisa , Palermo Claire , Molloy Liz
Published: August 2011

Background:

Listening and communication are two critical aspects of positive relationships. In the context of health care, they have been found to have a positive impact on many aspects of client care, including patient satisfaction, emotional wellbeing, and functional and physiological status. However, little is understood about the specific listening and communication styles exhibited by students enrolled in the health-related disciplines, including occupational therapy. The aim of this study was to investigate the listening and communication styles of undergraduate occupational therapy students.

Method:

This was a cross-sectional study of 210 students (response rate of 95.5%) enrolled in a Bachelor of Occupational Therapy (BOT) course, who completed paper-based versions of the Listening Styles Profile (LSP) and the Communicator Style Measure (CSM). Both the LSP and CSM are valid and reliable measures.

Results:

Participants reported a strong preference for the People listening style and the Friendly and Attentive communication styles. A moderate preference was also shown for the Content listening style. There were only two minor differences between participants enrolled in the different year levels of the BOT course, and only minor differences between the male and female students.

Conclusion:

The participants' reported preferences are well suited for the role of occupational therapy. The findings suggest that occupational therapy students exhibit a disposition towards listening and communication styles that are indicative of an underlying interest in the care and welfare of others and which are traits of the ‘helping, people-oriented’ professions. The implications of these findings are that it is important to consider the listening and communication styles of occupational therapy students during their professional education and while completing practice placement education.
Influences of the variation in inflow to East Asia on surface ozone over Japan during 1996–2005
Authors: Chatani S. , Sudo K.
Published: August 2011

Abstract. Air quality simulations in which the global chemical transport model CHASER and the regional chemical transport model WRF/chem are coupled have been developed to consider the dynamic transport of chemical species across the boundaries of the domain of the regional chemical transport model. The simulation captures the overall seasonal variations of surface ozone, but overestimates its concentration over Japanese populated areas by approximately 20 ppb from summer to early winter. It is deduced that ozone formation around Northeast China and Japan in summer is overestimated in the simulation. On the other hand, the simulation well reproduces the interannual variability and the long-term trend of observed surface ozone over Japan. Sensitivity experiments have been performed to investigate the influence of the variation in inflow to East Asia on the interannual variability and the long-term trend of surface ozone over Japan during 1996–2005. The inflow defined in this paper includes the recirculation of species with sources within the East Asian region as well as the transport of species with sources out of the East Asian region. Results of sensitivity experiments suggest that inflow to East Asia accounts for approximately 30 % of the increasing trend of surface ozone, whereas it has much less influence on the interannual variability of observed surface ozone compared to meteorological processes within East Asia.
Insights from a joint analysis of Indian and Chinese monsoon rainfall data
Authors: Zhou M. , Tian F. , Lall U. , Hu H.
Published: August 2011

Abstract. Monsoon rainfall is of great importance for agricultural production in both China and India. Understanding the features of the Indian and Chinese monsoon rainfall and its long term predictability is a challenge for research. In this paper Principal Component Analysis (PCA) method was adopted to analyze Indian monsoon and Chinese monsoon separately as well as jointly during the period 1951 to 2003. The common structure of Indian monsoon and Chinese monsoon rainfall data was explored, and its correlation with large scale climate indices and thus the possibility of prediction were analyzed. The joint PCA results gives a clearer correlation map between Chinese monsoon rainfall and Indian monsoon rainfall. The common rainfall structure presents a significant teleconnection to Sea Surface Temperature anomaly (SSTa), moisture transport and other climate indices. Specifically, our result shows that Northern China would garner less rainfall when whole Indian rainfall is below normal, and with cold SSTa over the Indonesia region more rainfall would be distributed over India and Southern China. The result also shows that SSTa in the previous winter months could be a good indicator for the summer monsoon rainfall in China.
An empirical stochastic model of sea-surface temperature and surface wind over the Southern Ocean
Authors: Kravtsov S. , Kondrashov D. , Kamenkovich I. , Ghil M.
Published: August 2011

Abstract. This study employs NASA's recent satellite measurements of sea-surface temperature (SST) and sea-level wind (SLW) with missing data filled-in by Singular Spectrum Analysis (SSA), to construct empirical models that capture both intrinsic and SST-dependent aspects of SLW variability. The model construction methodology uses a number of algorithmic innovations that are essential in providing stable estimates of model's propagator. The best model tested herein is able to faithfully represent the time scales and spatial patterns of anomalies associated with a number of distinct processes. These processes range from the daily synoptic variability to interannual signals presumably associated with oceanic or coupled dynamics. Comparing the simulations of an SLW model forced by the observed SST anomalies with the simulations of an SLW-only model provides preliminary evidence for the climatic behavior characterized by the ocean driving the atmosphere in the Southern Ocean region.
A new class of long‐term stable lunar resonance orbits: Space weather applications and the Interstellar Boundary Explorer
Authors: McComas D. J. , Carrico J. P. , Hautamaki B. , Intelisano M. , Lebois R. , Loucks M. , Policastri L. , Reno M. , Scherrer J. , Schwadron N. A. , Tapley M. , Tyler R.
Published: August 2011

NASA's Interstellar Boundary Explorer (IBEX) mission was recently maneuvered into a unique long‐term stable Earth orbit, with apogee at ∼50 Earth radii (RE). The Moon's (∼65 RE) gravity disrupts most highly elliptical Earth orbits, leading to (1) chaotic orbital solutions, (2) the inability to predict orbital positions more than a few years into the future, and ultimately (3) mission‐ending possibilities of atmospheric reentry or escape from Earth orbit. By synchronizing the satellite's orbital period to integer fractions of the Moon's sidereal period, PM = 27.3 days (e.g., PM/2 = 13.6 days, PM/3 = 9.1 days), and phasing apogee to stay away from the Moon, very long term stability can be achieved. Our analysis indicates orbital stability for well over a decade, and these IBEX‐like orbits represent a new class of Earth orbits that are stable far longer than typical satellite lifetimes. These orbits provide cost‐effective and nearly ideal locations for long‐term space weather observations from spacecraft that can remotely image the Earth's magnetosphere from outside its boundaries while simultaneously providing external (solar wind or magnetosheath) observation over most of their orbits. Utilized with multiple spacecraft, such orbits would allow continuous and simultaneous monitoring of the magnetosphere in order to help predict and mitigate adverse space weather–driven effects.
Evolution of Cerebral Cortical Development
Authors: Molnár Zoltán
Published: August 2011

Understanding how the human cerebral cortex evolved to its present complex state is a fascinating topic for neuroscience, genetics, bioinformatics and comparative biology. To gain further insights into the origins of the mammalian neocortex and to understand how the cortex evolved to be able to serve more complex cognitive functions, we study the development of various extant species. Our aim is to correlate cortical cell numbers and neuronal cell types with the elaboration of cortical progenitor populations and their modes of proliferation in different species. There are several progenitors, i.e. the ventricular radial glia, the subventricular intermediate progenitors and subventricular (outer) radial glia types, but the contribution of each to cortical layers and cell types through specific lineages is not fully understood. Recent comparisons of the proportions of these progenitors in various species during embryonic neurogenesis have revealed the elaboration and cytoarchitectonic compartmentalization of the germinal zone, with alterations in the proportions of various types that can be included among the intermediate progenitors. Across species, larger and more diverse intermediate progenitor populations correlate with brain size and cortical cell diversity. Understanding the molecular and cellular interactions regulating the divisions of these intermediate progenitors not only has implications for cortical evolution but also relates to stem cell biology and illuminates the pathomechanisms of several cortical developmental disorders.
National clinical portal programme: What information do doctors want?
Authors: Strachan K , Kelly C
Published: August 2011

Electronic patient health information in secondary care is often stored on different IT systems and not accessible to doctors involved in clinical decision-making. The Scottish Government will support clinical portal implementation in all Scottish Health Boards, which will present information from different sources as a virtual electronic patient record. An online survey was developed and sent to secondary care doctors, who were asked to rank the importance of different types of patient-centred information, knowledge support sources, and information to support appraisal and continued professional development that a clinical portal could deliver. Subgroup analysis was performed to investigate whether expectations differed between senior clinicians and doctors in training. Replies were received from 677 senior doctors and 137 trainees. Patient-centric information such as current medication and allergies, clinical alerts, past medical history, diagnostic test results and clinical letters were ranked as most important. Doctors would also like access to knowledge support, such as clinical guidelines. Eighteen of the top 20 ranked information types were consistent between senior doctors and those in training grades. In conclusion, senior doctors and trainees consistently want to see similar information in the clinical portal which is largely patient-centred with some provision for knowledge support.
Child Marriage in the United States and Its Association With Mental Health in Women
Authors: Le Strat Yann , Dubertret Caroline , Le Foll Bernard
Published: August 2011

OBJECTIVE:

Despite the devastating impact of child marriage (marriage before the age of 18 years) on health, no study has yet evaluated its impact on mental health in the general adult population. This article presents nationally representative data on the prevalence, sociodemographic correlates, and psychiatric comorbidity of child marriage among women in the United States.

METHODS:

Data were drawn from the 2001–2002 National Epidemiologic Survey on Alcohol and Related Conditions. We limited our analyses to the sample of women (N = 24 575) with a known age at first marriage, of whom 18 645 had been or were presently married.

RESULTS:

The prevalence of child marriage among women was 8.9%. Demographic factors associated with child marriage were black and American Indian/Alaska Native ethnicities, age at interview of >45 years, low educational level, low income, and living in the South and rural areas of the United States. The overall lifetime and 12-month rates of psychiatric disorders were higher for women who married as children, compared with women who married as adults. In addition, women who married as children were more likely to seek and access health services, compared with women who married in adulthood.

CONCLUSIONS:

Child marriage increases the risk of lifetime and current psychiatric disorders in the United States. Support for psychiatric vulnerabilities among women married in childhood is required.
Diagnosis and Management of an Initial UTI in Febrile Infants and Young Children
Authors: Finnell S. Maria E. , Carroll Aaron E. , Downs Stephen M. ,   the Subcommittee on Urinary Tract Infection
Published: August 2011

OBJECTIVES:

The diagnosis and management of urinary tract infections (UTIs) in young children are clinically challenging. This report was developed to inform the revised, evidence-based, clinical guideline regarding the diagnosis and management of initial UTIs in febrile infants and young children, 2 to 24 months of age, from the American Academy of Pediatrics Subcommittee on Urinary Tract Infection.

METHODS:

The conceptual model presented in the 1999 technical report was updated after a comprehensive review of published literature. Studies with potentially new information or with evidence that reinforced the 1999 technical report were retained. Meta-analyses on the effectiveness of antimicrobial prophylaxis to prevent recurrent UTI were performed.

RESULTS:

Review of recent literature revealed new evidence in the following areas. Certain clinical findings and new urinalysis methods can help clinicians identify febrile children at very low risk of UTI. Oral antimicrobial therapy is as effective as parenteral therapy in treating UTI. Data from published, randomized controlled trials do not support antimicrobial prophylaxis to prevent febrile UTI when vesicoureteral reflux is found through voiding cystourethrography. Ultrasonography of the urinary tract after the first UTI has poor sensitivity. Early antimicrobial treatment may decrease the risk of renal damage from UTI.

CONCLUSIONS:

Recent literature agrees with most of the evidence presented in the 1999 technical report, but meta-analyses of data from recent, randomized controlled trials do not support antimicrobial prophylaxis to prevent febrile UTI. This finding argues against voiding cystourethrography after the first UTI.
Paleoenvironmental reconstruction of a Late Quaternary lagoon system in southern Brazil (Jaguaruna region, Santa Catarina state) based on multi‐proxy analysis
Authors: Carvalho do Amaral Paula Garcia , Fonseca Giannini Paulo César , Sylvestre Florence , Ruiz Pessenda Luiz Carlos
Published: August 2011

This paper provides a paleoenvironmental reconstruction of a Late Quaternary lagoon system in the Jaguaruna region of Santa Catarina state, southern Brazil. Integrated results of bulk sedimentary organic matter characterization (δ13C, δ15N and C/N), microfossil (pollen and diatom) and grain‐size analysis from three shallow cores (∼2.5 m depth) allowed us to propose an evolving paleogeographic scenario in this coastal region for the last ca. 5500 cal a BP. The lagoonal system in this area was more extensive during the mid‐Holocene than today, with a gradual and continuous lagoon–sea disconnection until the present. We add to the debate regarding relative sea‐level (RSL) variations for the Brazilian coast during the Holocene and discuss the importance of sedimentary dynamics for interpreting changes in coastal ecosystems. The multi‐proxy analysis suggests that changes in coastal ecosystems could be directly related to local sedimentary processes, which are not necessarily linked to RSL fluctuations and/or to climatic variations. Copyright © 2011 John Wiley & Sons, Ltd.
Clinically relevant information from sentinel lymph node biopsies of melanoma patients
Authors: Wen Duan‐Ren , Cochran Alistair J. , Huang Rong‐Rong , Itakura Eijun , Binder Scott
Published: August 2011

Careful laboratory evaluation of sentinel nodes (SNs) is critical to determine the presence of tumor. This requires evaluation of multiple full‐face sections from the SN, using H&E staining and immunohistochemistry. In the future, molecular and genetic approaches may be adjunctive to microscopy. Number of tumor‐positive SNs and the amount and location of tumor in SNs correlate with tumor spread to non‐sentinel nodes, subsequent recurrences and melanoma death, permitting patient assignment to a risk category. J. Surg. Oncol. 2011; 104:369–378. © 2011 Wiley‐Liss, Inc.
Self‐disclosure to the best friend: Friendship quality and internalized sexual stigma in Italian lesbian and gay adolescents
Authors: Baiocco Roberto , Laghi Fiorenzo , Di Pomponio Ileana , Nigito Concetta Simona
Published: August 2011

This study is the first contribution to the understanding of gender differences in best friendship patterns of adolescents sexual minorities. We explored friendship patterns, self‐disclosure, and internalized sexual stigma in an Italian sample of lesbian (N = 202) and gay (N = 201) adolescents (aged 14–22 years). We found gender differences in cross‐sex and cross‐orientation patterns of best friendship. Gay men (52%) reported more cross‐sex friendships than lesbians (20%). The 52% of participants had cross‐orientation friendships, and no differences were found between lesbians and gay men. Lesbian and gay men with a cross‐orientation best friend showed a lower level of internalized sexual stigma. Gay men with cross‐orientation friendship showed a low level of internalized sexual stigma and less conflict with a best friend. For gay men and lesbian participants, self‐disclosure to the best friend was better predicted by internalized sexual stigma and self‐disclosure. Future studies may provide direct comparisons between heterosexual and sexual minority individuals.
The combination of mifepristone and misoprostol for the termination of pregnancy
Authors: Faúndes Anibal ,   FIGO Working Group on the Prevention of Unsafe Abortion and its Consequences
Published: August 2011

The combination of 200 mg of mifepristone followed by 25 μg to 800 μg (depending on gestational age) of misoprostol has been shown to be effective for the termination of pregnancy throughout gestation. The dose of misoprostol should be reduced as gestational age increases. Mifepristone is not indicated for induction of labor with a live fetus because there are no data to confirm that it does not have a possible deleterious fetal effect. The course of treatment and prerequisites for medical abortion and recommended mifepristone and misoprostol regimens for different gestational ages are described, along with the side effects, management of complications, and postabortion care. The use of the mifepristone–misoprostol combination regimen for induction of labor in cases of fetal death is also described.
Primary Hyperaldosteronism
Authors: Djajadiningrat-Laanen Sylvia C , Galac Sara , Kooistra Hans
Published: August 2011

Practical relevance Primary hyperaldosteronism is probably the most common adrenocortical disorder in cats. As in humans, it is often unrecognised, which excludes a potentially large number of cats from appropriate treatment.

Patient group Affected cats present at a median age of 13 years (range 5–20 years). A breed or sex predilection has not been documented. The excessive secretion of mineralocorticoids usually leads to hypokalaemia and/or systemic arterial hypertension. Most affected cats present with muscular weakness and/or ocular signs of arterial hypertension.

Diagnostics In any cat presenting with hypokalaemia and/or arterial hypertension, other potential causes should be excluded. The ratio of plasma aldosterone concentration to plasma renin activity (aldosterone:renin ratio) is currently the best screening test for feline primary hyperaldosteronism. Diagnostic imaging is required to differentiate between adrenocortical neoplasia and bilateral hyperplasia, and to detect any distant metastases.

Clinical challenges The differentiation between adrenocortical neoplasia and bilateral hyperplasia is imperative for planning optimal therapy, but the limited sensitivity of diagnostic imaging may occasionally pose a problem. For confirmed unilateral primary hyperaldosteronism, unilateral adrenalectomy is the treatment of choice, and offers an excellent prognosis, but potentially fatal intra- and postoperative haemorrhage is a reported complication and risk factors have yet to be identified.

Evidence base Only a few case reports are available on which to base the optimal diagnostic and therapeutic approach to feline primary hyperaldosteronism. This article reviews the physiology of aldosterone production and the pathophysiology of primary hyperaldosteronism, and summarises the currently available literature on the feline disease. Practical suggestions are given for the diagnostic investigation of cats with suspected primary hyperaldosteronism.
Brain Abscess in Seven Cats Due to a Bite Wound: MRI Findings, Surgical Management and Outcome
Authors: Costanzo Chiara , Garosi Laurent S , Glass Eric N , Rusbridge Clare , Stalin Catherine E , Volk Holger A
Published: August 2011

Presentation and lesion localisation Seven adult domestic shorthair cats were presented with a 1- to 6-day history of progressive neurological signs. A focal skin puncture and subcutaneous swelling over the dorsal part of the head were detected on physical examination. Neurological examination indicated lesion(s) in the right forebrain in four cats, multifocal forebrain in one cat, left forebrain in one cat, and multifocal forebrain and brainstem in the remaining cat. In all cats, magnetic resonance imaging revealed a space-occupying forebrain lesion causing a severe mass effect on adjacent brain parenchyma.

Clinical approach and outcome All cats were managed with a combination of medical and surgical treatment. At surgery a small penetrating calvarial fracture was detected in all cats, and a tooth fragment was found within the content of the abscess in two cats. The combination of surgical intervention, intensive care and intravenous antimicrobials led to a return to normal neurological function in five cats.

Practical relevance As this series of cases indicates, successful resolution of a brain abscess due to a bite injury depends on early recognition and combined used of antimicrobials and surgical intervention. A particular aim of surgery is to remove any skull and foreign body (tooth) fragments that may represent a continuing focus of infection.
Glutathione‐S‐transferase enhances proliferation‐migration and protects against shikonin‐induced cell death in breast cancer cells
Authors: He Shiping , Liao Tsai‐Tsen , Chen Yi‐Ting , Kuo Hsiu‐Maan , Lin Ya‐Ling
Published: August 2011

Glutathione‐S‐transferase (GST) is a cytoplasmic protein responsible for detoxification, but the effect of the enzyme on cell biological events, including proliferation and migration, has never been reported. Thus, we evaluated the detoxification effect of in vitro–applied GST on cancer cell proliferation and migration. Assays for proliferation and migration of human breast cancer cells in the presence of GST were carried out. Binding of GST on the surface of the cancer cells was studied by flow cytometry. Detoxification through GST pathway was studied in the presence of shikonin. The effective dosage of GST in enhancement of cell proliferation was 10–50 nM, and the cell migration could be significantly enhanced after 6 hours in the presence of 2–50 nM GST. Therefore, overall cell proliferation and migration could be enhanced in the presence of 10 nM or greater concentration of GST, and 15 μM shikonin‐induced toxification of the cancer cells could be neutralized by 1.0 μM GST. Flow cytometry showed that GST directly bound to the surface of the cancer cells, and this was confirmed by fluorescence confocal microscopic observation. It is concluded that human class π‐GST enhances proliferation and migration of human breast cancer cells by means of direct binding to the cell surface and maintaining cell viability by detoxification.
Frictional sliding across Coulombic faults in first‐year sea ice: A comparison with freshwater ice
Authors: Fortt Andrew L. , Schulson Erland M.
Published: August 2011

Frictional sliding plays a fundamental role in the deformation of the Arctic Ocean ice cover and in ice‐structure interactions. To examine its character, sliding experiments were performed along freshly created Coulombic faults in first‐year S2 sea ice harvested from the Beaufort Sea during the winters of 2003, 2007, and 2009. For comparison, and to complement experiments performed earlier, we also examined freshwater ice of similar microstructure. The principal variables were sliding velocity (from 8 × 10−7 m s−1 to 4 × 10−3 m s−1), temperature (−40°C, −10°C, and −3°C) and normal stress (from 0.02 to 2.7 MPa). Over the ranges explored, the coefficient of friction varies by a factor of four, from ∼0.4 to ∼1.6. The coefficient for both materials reaches a maximum value at an intermediate velocity, which is an order of magnitude higher for sea ice (∼10−4 m s−1) than for freshwater ice (∼10−5 m s−1). At lower velocities, sliding is characterized by velocity strengthening where, for a given velocity, the coefficient of friction of sea ice is lower than that of freshwater ice. At higher velocities, sliding is characterized by velocity weakening, where, for a given velocity, the coefficients of friction for sea ice is closer to that of freshwater ice. Velocity strengthening is explained in terms of creep deformation within contact zones along the fault. Velocity weakening is tentatively attributed to a combination of fracture and localized melting. An implication of stable versus unstable sliding is discussed for sea ice mechanics.
Isolating the multipath component in GNSS signal‐to‐noise data and locating reflecting objects
Authors: Benton C. J. , Mitchell C. N.
Published: August 2011

A filter to separate the effect of multipath in Global Navigation Satellite System (GNSS) signal‐to‐noise ratio (SNR) data is presented. The filter removes multipath cleanly, and affects neither slowly varying trends (such as tropospheric absorption or variation in satellite range) nor high frequency components (such as ionospheric scintillation), and so is potentially useful in space‐weather research. Similarly, the multipath data removed from the input data is minimally distorted, and contains useful information as to the multipath geometry. A method to locate reflecting objects using a form of spectral analysis is described.
Thermal conductivity and refractive index of hafnia-alumina nanolaminates
Authors: Gabriel Nicholas T. , Talghader Joseph J.
Published: August 2011

Hafnia-alumina nanolaminates show improved smoothness and reduced crystallinity relative to pure hafnia in films formed by atomic layer deposition (ALD). However, typical nanolaminates also show reduced cross-plane thermal conductivity due to the much larger interface density relative to continuous films. We find that the interface thermal resistance in hafnia-alumina nanolaminates is very low and does not dominate the film thermal conductivity, which is 1.0 to 1.2 W/(m K) at room temperature in 100 nm thin films regardless of the interface density. Measured films had a number of interfaces ranging from 2 to 40, equivalent to interface spacing varying from about 40 to 2 nm. The degree of crystallinity of these films appears to have a much larger effect on thermal conductivity than that of interface density. Cryogenic measurements show good agreement with both the minimum thermal conductivity model for disordered solids and the diffuse mismatch model of interface resistance down to about 80 K before diverging. We find that the films are quite smooth through a 400:5 ratio of hafnia to alumina in terms of ALD cycles, and the refractive index scales as expected with increasing alumina concentration.
In-plane and growth direction electron cyclotron effective mass in short period InAs/GaSb semiconductor superlattices
Authors: Suchalkin S. , Belenky G. , Svensson S. P. , Laikhtman B. , Smirnov D. , Tung L. C. , Bandara S.
Published: August 2011

In plane and growth direction electron effective mass in short period InAs/GaSb semiconductor superlattices (SL) was measured using cyclotron resonance at different orientations of magnetic field with respect to SL growth direction. It was demonstrated that the electron spectrum near the bottom of the SL subband has 3D character, with the in-plane effective masses ranging from 0.023 m0 to 0.028 m0 and growth direction effective masses of 0.03–0.034 m0 depending on the SL period and growth conditions. The measured effective masses are close to those calculated in the weak coupling limit of the Kronig-Penney model. In this limit the SL electron effective mass is a weighted average of the electron effective masses of corresponding bulk materials. Correlation between the magnitude of cyclotron mobility, amplitude of negative magnetoresistance, and steepness of the long wavelength side of the photoluminescence spectrum indicate that the crystalline structure disorder is a major factor contributing to the momentum relaxation time of the electrons.
Thermal expansions in wurtzite AlN, GaN, and InN: First-principle phonon calculations
Authors: Xu Li-Chun , Wang Ru-Zhi , Yang Xiaodong , Yan Hui
Published: August 2011

Using the first-principle phonon calculations under the quasiharmonic approximation, thermal expansions in III-nitrides with wurtzite AlN, GaN, and InN are reported. The results showed that it is different for each thermal expansion of three III-nitrides at low temperatures, which is consistent with their Grüneisen parameters as the function of temperature. Below 50 K, negative thermal expansions occur in InN, while GaN and AlN follow the rule of positive thermal expansion. To seek the origin of positive/negative thermal expansion distinction, the mode Grüneisen parameters and the phonon spectra are investigated. They indicate that different low-frequency phonon vibration modes correspond to the change of thermal expansions. Below 5 THz, the significant weighted negative values of mode Grüneisen parameters, caused by the weakening of mixing-mode constituted with two transverse acoustic (TA) modes and a small overlapped part of optical modes, directly lead to the negative thermal expansion at low temperatures.
Chemical vapor deposition graphene as structural template to control interfacial molecular orientation of chloroaluminium phthalocyanine
Authors: Ying Mao Hong , Wang Rui , Wang Yu , Chao Niu Tian , Qiang Zhong Jian , Yang Huang Ming , Chen Qi Dong , Ping Loh Kian , Thye Shen Wee Andrew , Chen Wei
Published: August 2011

Chemical vapor deposition (CVD) graphene has been used as an effective structural template to manipulate molecular orientation of organic thin film of chloroaluminium phthalocyanine (ClAlPc) on indium tin oxide (ITO) electrode. As revealed by in-situ near-edge x-ray adsorption fine structure measurement, ClAlPc molecules on the CVD graphene modified ITO electrode adopt a well-aligned lying-down configuration with their molecular π-plane nearly parallel to the electrode surface, in contrast to the random orientation of ClAlPc molecules on the bare ITO electrode. This lying-down configuration results in an optimized stacking of the molecular π-plane perpendicular to the electrode surface and hence facilitates efficient charge transport along this direction.
Fourier magnetic imaging
Authors: Verduci T. , Rufo C. , Berger A. , Metlushko V. , Ilic B. , Vavassori P.
Published: August 2011

We present a methodology for the extraction of the spatial Fourier components of the magnetization profile for an array of nanosized magnetic objects, from diffracted magneto optic Kerr effect measurements. The field dependent magnetization configuration in the unit cell is retrieved by inverse Fourier transform and compared with the predictions of micromagnetic simulations. The comparison demonstrates that the methodology is a powerful optical tool for lens-less diffraction-limited optical imaging of the collective magnetic behavior of nano-structures.
Dynamics and particle fluxes in atmospheric-pressure electronegative radio frequency microplasmas
Authors: McKay K. , Liu D. X. , Rong M. Z. , Iza F. , Kong M. G.
Published: August 2011

We report on intricate dynamics observed in atmospheric-pressure rf electronegative discharges where electrons and anions are separated due to their different mobilities. This results in the formation of positively charged regions between an electronegative plasma core and an oscillating electron ensemble. It is found that for a given input power, the electron, ion (both positive and negative) and neutral fluxes increase as the gap size is reduced, resulting in a more efficient delivery of chemical species to a treated target.
Contiguity and the Quantum Theory of Measurement
Authors: Green HS
Published: August 2011

This paper presents a comprehensive treatement of the problem of measurement in microscopic physics, consistent with the indeterministic Copenhagen interpretation of quantum mechanics and information theory. It is pointed out that there are serious difficulties in reconciling the deterministic interpretations of quantum mechanics, based on the concepts of a universal wave function or hidden variables, with the principle of contiguity. Quantum mechanics is reformulated entirely in terms of observables, represented by matrices, including the statistical matrix, and the utility of information theory is illustrated by a discussion of the EPR paradox. The principle of contiguity is satisfied by all conserved quantities. A theory of the operation of macroscopic measuring devices is given in the interaction repesentation, and the attenuation of the indeterminacy of a microscopic observable in the process of measurement is related to observable changes of entropy.
Optical Characteristics of Some Binary and Ternary Phosphate Glasses
Authors: Ashraf Chaudhry M , Manzoor Rana Anwar , Altaf M , Shakeel Bilal M
Published: August 2011

The optical absorption spectra of some binary and ternary phosphate glasses are studied in the UV-visible region by using a spectrophotometer. The observed absorbance versus wavelength curves do not show any sharp edges in these glasses. The optical band gap energies are found to depend significantly on glass composition. The optical band gap energy is found to increase with increasing ZnO content in binary and ternary glass systems.
Reiterative Recombination for the in vivo assembly of libraries of multigene pathways
Authors: Wingler Laura M. , Cornish Virginia W.
Published: August 2011

The increasing sophistication of synthetic biology is creating a demand for robust, broadly accessible methodology for constructing multigene pathways inside of the cell. Due to the difficulty of rationally designing pathways that function as desired in vivo, there is a further need to assemble libraries of pathways in parallel, in order to facilitate the combinatorial optimization of performance. While some in vitro DNA assembly methods can theoretically make libraries of pathways, these techniques are resource intensive and inherently require additional techniques to move the DNA back into cells. All previously reported in vivo assembly techniques have been low yielding, generating only tens to hundreds of constructs at a time. Here, we develop “Reiterative Recombination,” a robust method for building multigene pathways directly in the yeast chromosome. Due to its use of endonuclease-induced homologous recombination in conjunction with recyclable markers, Reiterative Recombination provides a highly efficient, technically simple strategy for sequentially assembling an indefinite number of DNA constructs at a defined locus. In this work, we describe the design and construction of the first Reiterative Recombination system in
Saccharomyces cerevisiae
, and we show that it can be used to assemble multigene constructs. We further demonstrate that Reiterative Recombination can construct large mock libraries of at least 10
4
biosynthetic pathways. We anticipate that our system’s simplicity and high efficiency will make it a broadly accessible technology for pathway construction and render it a valuable tool for optimizing pathways in vivo.
The former annotated human pseudogene dihydrofolate reductase-like 1 (
DHFRL1
) is expressed and functional
Authors: McEntee Gráinne , Minguzzi Stefano , O’Brien Kirsty , Ben Larbi Nadia , Loscher Christine , Ó’Fágáin Ciarán , Parle-McDermott Anne
Published: August 2011

Human dihydrofolate reductase (DHFR) was previously thought to be the only enzyme capable of the reduction of dihydrofolate to tetrahydrofolate; an essential reaction necessary to ensure a continuous supply of biologically active folate. DHFR has been studied extensively from a number of perspectives because of its role in health and disease. Although the presence of a number of intronless
DHFR
pseudogenes has been known since the 1980s, it was assumed that none of these were expressed or functional. We show that humans do have a second dihydrofolate reductase enzyme encoded by the former pseudogene
DHFRP4
, located on chromosome 3. We demonstrate that the
DHFRP4
, or dihydrofolate reductase-like 1 (
DHFRL1
), gene is expressed and shares some commonalities with DHFR. Recombinant DHFRL1 can complement a
DHFR
-negative phenotype in bacterial and mammalian cells but has a lower specific activity than DHFR. The
K

m

for NADPH is similar for both enzymes but DHFRL1 has a higher
K

m

for dihydrofolate when compared to DHFR. The need for a second reductase with lowered affinity for its substrate may fulfill a specific cellular requirement. The localization of DHFRL1 to the mitochondria, as demonstrated by confocal microscopy, indicates that mitochondrial dihydrofolate reductase activity may be optimal with a lowered affinity for dihydrofolate. We also found that DHFRL1 is capable of the same translational autoregulation as DHFR by binding to its own mRNA; with each enzyme also capable of replacing the other. The identification of DHFRL1 will have implications for previous research involving DHFR.
Observation of spatial propagation of amyloid assembly from single nuclei
Authors: Knowles Tuomas P. J. , White Duncan A. , Abate Adam R. , Agresti Jeremy J. , Cohen Samuel I. A. , Sperling Ralph A. , De Genst Erwin J. , Dobson Christopher M. , Weitz David A.
Published: August 2011

The crucial early stages of amyloid growth, in which normally soluble proteins are converted into fibrillar nanostructures, are challenging to study using conventional techniques yet are critical to the protein aggregation phenomena implicated in many common pathologies. As with all nucleation and growth phenomena, it is difficult to track individual nuclei in traditional macroscopic experiments, which probe the overall temporal evolution of the sample, but do not yield detailed information on the primary nucleation step as they mix independent stochastic events into an ensemble measurement. To overcome this limitation, we have developed microdroplet assays enabling us to detect single primary nucleation events and to monitor their subsequent spatial as well as temporal evolution, both of which we find to be determined by secondary nucleation phenomena. By deforming the droplets to high aspect ratio, we visualize in real-time propagating waves of protein assembly emanating from discrete primary nucleation sites. We show that, in contrast to classical gelation phenomena, the primary nucleation step is characterized by a striking dependence on system size, and the filamentous protein self-assembly process involves a highly nonuniform spatial distribution of aggregates. These findings deviate markedly from the current picture of amyloid growth and uncover a general driving force, originating from confinement, which, together with biological quality control mechanisms, helps proteins remain soluble and therefore functional in nature.
Finding recurrent copy number alterations preserving within-sample homogeneity
Authors: Morganella Sandro , Pagnotta Stefano Maria , Ceccarelli Michele
Published: August 2011

Motivation: Copy number alterations (CNAs) represent an important component of genetic variation and play a significant role in many human diseases. Development of array comparative genomic hybridization (aCGH) technology has made it possible to identify CNAs. Identification of recurrent CNAs represents the first fundamental step to provide a list of genomic regions which form the basis for further biological investigations. The main problem in recurrent CNAs discovery is related to the need to distinguish between functional changes and random events without pathological relevance. Within-sample homogeneity represents a common feature of copy number profile in cancer, so it can be used as additional source of information to increase the accuracy of the results. Although several algorithms aimed at the identification of recurrent CNAs have been proposed, no attempt of a comprehensive comparison of different approaches has yet been published.

Results: We propose a new approach, called Genomic Analysis of Important Alterations (GAIA), to find recurrent CNAs where a statistical hypothesis framework is extended to take into account within-sample homogeneity. Statistical significance and within-sample homogeneity are combined into an iterative procedure to extract the regions that likely are involved in functional changes. Results show that GAIA represents a valid alternative to other proposed approaches. In addition, we perform an accurate comparison by using two real aCGH datasets and a carefully planned simulation study.

Availability: GAIA has been implemented as R/Bioconductor package. It can be downloaded from the following page http://bioinformatics.biogem.it/download/gaia

Contact:  ceccarelli@unisannio.it; morganella@unisannio.it

Supplementary Information:  Supplementary data are available at Bioinformatics online.