bluuebunny/crossref_metadata_2025 huggingface dataset:
Trends in Occupational Segregation by Gender 1970–2009: Adjusting for the Impact of Changes in the Occupational Coding System
Authors: Blau Francine D. , Brummund Peter , Liu Albert Yung-Hsu
Published: October 2012

In this article, we develop a gender-specific crosswalk based on dual-coded Current Population Survey data to bridge the change in the census occupational coding system that occurred in 2000 and use it to provide the first analysis of the trends in occupational segregation by sex for the 1970–2009 period based on a consistent set of occupational codes and data sources. We show that our gender-specific crosswalk more accurately captures the trends in occupational segregation that are masked using the aggregate crosswalk (based on combined male and female employment) provided by the U.S. Census Bureau. Using the 2000 occupational codes, we find that segregation by sex declined substantially over the period but at a diminished pace over the decades, falling by only 1.1 percentage points (on a decadal basis) in the 2000s. A primary mechanism by which segregation was reduced was through the entry of new cohorts of women, presumably better prepared than their predecessors and/or encountering less labor market discrimination; during the 1970s and 1980s, however, occupational segregation also decreased within cohorts. Reductions in segregation were correlated with education, with the largest decrease among college graduates and very little change in segregation among high school dropouts.
Preferred question types for computer-based assessment of clinical reasoning: a
literature study
Authors: Van Bruggen Lisette , Manrique-van Woudenbergh Margreet , Spierenburg Emely , Vos Jacqueline
Published: October 2012

Clinical reasoning is a core competence of doctors. Therefore, the assessment of
clinical reasoning of undergraduate students is an important part of medical education.
Three medical universities in the Netherlands wish to develop a shared question database
in order to assess clinical reasoning of undergraduate students in Computer-Based
Assessments (CBA). To determine suitable question types for this purpose a literature
study was carried out. Search of ERIC and PubMed and subsequent cross referencing
yielded 30 articles which met the inclusion criteria of a focus on question types
suitable to assess clinical reasoning of medical students and providing recommendations
for their use. Script Concordance Tests, Extended Matching Questions, Comprehensive
Integrative Puzzles, Modified Essay Questions/Short Answer Questions, Long Menu
Questions, Multiple Choice Questions, Multiple True/False Questions and Virtual Patients
meet the above-mentioned criteria, but for different reasons not all types can be used
easily in CBA. A combination of Comprehensive Integrative Puzzles and Extended Matching
Questions seems to assess most aspects of clinical reasoning and these question types
can be adapted for use in CBA. Regardless of the question type chosen, patient vignettes
should be used as a standard stimulus format to assess clinical reasoning. Further
research is necessary to ensure that the combination of these question types produces
valid assessments and reliable test results.
Geometric scaling of a purely elastic flow instability in serpentine channels
Authors: Zilz J. , Poole R. J. , Alves M. A. , Bartolo D. , Levaché B. , Lindner A.
Published: October 2012

A combined experimental, numerical and theoretical investigation of the geometric scaling of the onset of a purely elastic flow instability in serpentine channels is presented. Good qualitative agreement is obtained between experiments, using dilute solutions of flexible polymers in microfluidic devices, and three-dimensional numerical simulations using the upper-convected Maxwell model. The results are confirmed by a simple theoretical analysis, based on the dimensionless criterion proposed by Pakdel & McKinley (Phys. Rev. Lett., vol. 77, 1996, pp. 2459–2462) for onset of a purely elastic flow instability. Three-dimensional simulations show that the instability is primarily driven by the curvature of the streamlines induced by the flow geometry and not due to the weak secondary flow in the azimuthal direction. In addition, the simulations also reveal that the instability is time-dependent and that the flow oscillates with a well-defined period and amplitude close to the onset of the supercritical instability.
Spreading dynamics of drop impacts
Authors: Lagubeau Guillaume , Fontelos Marco A. , Josserand Christophe , Maurel Agnès , Pagneux Vincent , Petitjeans Philippe
Published: October 2012

We present an experimental study of drop impact on a solid surface in the spreading regime with no splashing. Using the space–time-resolved Fourier transform profilometry technique, we can follow the evolution of the drop shape during the impact. We show that a self-similar dynamical regime drives the drop spreading until the growth of a viscous boundary layer from the substrate selects a residual minimal film thickness. Finally, we discuss the interplay between capillary and viscous effects in the spreading dynamics, which suggests a pertinent impact parameter.
Surface pressure fluctuations on steps immersed in turbulent boundary layers
Authors: Ji Minsuk , Wang Meng
Published: October 2012

Surface pressure fluctuations induced by turbulent boundary-layer flow at ${\mathit{Re}}_{\theta } = 4755$ over small backward- and forward-facing steps are studied with large-eddy simulation. Four step heights that are 53, 13, 3.3 and 0.83 % of the boundary-layer thickness are considered to investigate the effects of step height on surface pressure characteristics and pressure-source mechanisms. The extent to which turbulent velocity fluctuations in the boundary layer and the separated shear layer contribute to the surface pressure fluctuations is examined with scaling of various pressure statistics and two-point correlations. For larger steps, vortical structures develop in the shear layer and the associated intense velocity fluctuations are the dominant source. Downstream of slightly less than one reattachment length from the step, the root-mean-square pressure is found to scale with the local maximum cross-stream Reynolds normal stress ${ \overline{{v}^{\ensuremath{\prime} \hspace{0.167em} 2} } }_{\mathit{max}} $. The pressure frequency spectrum at the maximum ${p}_{\mathit{rms}} $ location consists of an energy-containing range that scales with the mean reattachment length ${x}_{r} $ and a higher frequency range that rolls off with a slope close to $\ensuremath{-} 7/ 3$. As the step height decreases, the boundary-layer turbulent fluctuations become the dominant source, the ${ \overline{{v}^{\ensuremath{\prime} \hspace{0.167em} 2} } }_{\mathit{max}} $ scaling of ${p}_{\mathit{rms}} $ is no longer valid and the roll-off slope of the frequency spectrum becomes steeper. The downstream recovery of a step-perturbed boundary layer towards an equilibrium boundary layer is investigated from the point of view of surface pressure fluctuations. For steps with a strong separated shear layer, pressure fluctuations are found to decay rapidly for up to three reattachment lengths downstream of the step, within which approximately 60 % of the peak ${p}_{\mathit{rms}} $ is dissipated. Farther downstream, recovery is much slower. The pressure-recovery distances estimated for the largest backward and forward steps are 175 and 295 step heights, respectively.
n-3 Long-chain PUFA reduce allergy-related mediator release by human mast cellsin vitrovia inhibition of reactive oxygen species
Authors: van den Elsen Lieke W. J. , Nusse Yvette , Balvers Martin , Redegeld Frank A. , Knol Edward F. , Garssen Johan , Willemsen Linette E. M.
Published: October 2012

Increasedn-6 and reducedn-3 long-chain PUFA (LC-PUFA) intake in Western diets may contribute to the increased prevalence of allergic diseases. Key effector cells in allergy are mast cells (MC). The aim of the present study was to investigate the effects ofn-6v.n-3 LC-PUFA on MC phenotype. Human MC lines (LAD2 and HMC-1) were incubated for 24 h with either arachidonic acid (AA,n-6 LC-PUFA) or then-3 LC-PUFA EPA or DHA. The effects of these three LC-PUFA on degranulation, mediator secretion and reactive oxygen species (ROS) generation were assessed. ROS, mitogen-activated protein kinase (MAPK) or NF-κB inhibitors were used to unravel signalling pathways involved in cytokine secretion. AA, EPA or DHA did not reduce IgE-mediated degranulation by LAD2 cells. However, AA increased PGD2and TNF-α secretion by ionomycin/phorbol 12-myristate 13-acetate-stimulated HMC-1, whereas EPA and DHA more prominently inhibited IL-4 and IL-13 secretion. Suppression of IL-4 and IL-13 release by LC-PUFA correlated with reduced ROS generation. IL-4 and IL-13 release by activated HMC-1 was abrogated using ROS inhibitors. Inhibition of MAPK signalling, but not NF-κB, downstream of ROS reduced IL-13 secretion by activated HMC-1. Combined incubation of EPA or DHA with MAPK inhibitors further suppressed IL-13 secretion. In conclusion, then-6 LC-PUFA AA enhanced pro-inflammatory mediator production by MC, while then-3 LC-PUFA EPA as well as DHA more effectively suppressed ROS generation and IL-4 and IL-13 release. This suggests that dietary supplementation with EPA and/or DHA may alter the MC phenotype, contributing to a reduced susceptibility to develop and sustain allergic disease.
Effect of Lactobacillus rhamnosus LGG® and Bifidobacterium animalis ssp. lactis BB-12® on health-related quality of life in college students affected by upper respiratory infections
Authors: Smith Tracey J. , Rigassio-Radler Diane , Denmark Robert , Haley Timothy , Touger-Decker Riva
Published: October 2012

College students are susceptible to upper respiratory infections (URI) due to inadequate sleep, stress and close living quarters. Certain probiotic strains modulate immune function and may improve health-related quality of life (HRQL) during URI. The present study recruited apparently healthy college students and assessed the effect of probiotics on HRQL outcomes (i.e. self-reported duration, symptom severity and functional impairment of URI) in those who developed URI. Missed school and work days due to URI were also considered. Subjects (n 231) were apparently healthy college students living on campus in residence halls at the Framingham State University (Framingham, MA, USA), and were randomised to receive placebo (n 117) or probiotic-containing powder (daily dose of minimum 1 billion colony-forming units of each Lactobacillus rhamnosus LGG® (LGG®) and Bifidobacterium animalis ssp. lactis BB-12® (BB-12®); n 114) for 12 weeks. Subjects completed The Wisconsin Upper Respiratory Symptom Survey-21 to assess HRQL during URI. The final analyses included 198 subjects (placebo, n 97 and probiotics, n 101). The median duration of URI was significantly shorter by 2 d and median severity score was significantly lower by 34 % with probiotics v. placebo (P< 0·001), indicating a higher HRQL during URI. Number of missed work days was not different between groups (P= 0·429); however, the probiotics group missed significantly fewer school days (mean difference = 0·2 d) compared to the placebo group (P= 0·002). LGG® and BB-12® may be beneficial among college students with URI for mitigating decrements in HRQL. More research is warranted regarding mechanisms of action associated with these findings and the cost–benefit of prophylactic supplementation.
Influenza A (H1N1): a rare cause of deafness in two children
Authors: Alsanosi A A
Published: October 2012

Objective:

We report deafness occurring as an extremely rare complication of influenza A caused by the H1N1 virus (‘swine flu’), in two children.

Methods:

Case reports and review of the literature concerning influenza A (H1N1) and acquired viral infection causing deafness.

Results:

Two children with normal hearing developed bilateral deafness following influenza A (H1N1). The diagnosis was confirmed using polymerase chain reaction. Both patients were treated with oseltamivir.

Conclusion:

Following a review of the literature, these two patients appear to be the first reported cases of bilateral deafness following influenza A (H1N1).
Cannabis affects people differently: inter-subject variation in the psychotogenic effects of Δ9-tetrahydrocannabinol: a functional magnetic resonance imaging study with healthy volunteers
Authors: Atakan Z. , Bhattacharyya S. , Allen P. , Martín-Santos R. , Crippa J. A. , Borgwardt S. J. , Fusar-Poli P. , Seal M. , Sallis H. , Stahl D. , Zuardi A. W. , Rubia K. , McGuire P.
Published: October 2012

Background

Cannabis can induce transient psychotic symptoms, but not all users experience these adverse effects. We compared the neural response to Δ9-tetrahydrocannabinol (THC) in healthy volunteers in whom the drug did or did not induce acute psychotic symptoms.

Method

In a double-blind, placebo-controlled, pseudorandomized design, 21 healthy men with minimal experience of cannabis were given either 10 mg THC or placebo, orally. Behavioural and functional magnetic resonance imaging measures were then recorded whilst they performed a go/no-go task.

Results

The sample was subdivided on the basis of the Positive and Negative Syndrome Scale positive score following administration of THC into transiently psychotic (TP; n = 11) and non-psychotic (NP; n = 10) groups. During the THC condition, TP subjects made more frequent inhibition errors than the NP group and showed differential activation relative to the NP group in the left parahippocampal gyrus, the left and right middle temporal gyri and in the right cerebellum. In these regions, THC had opposite effects on activation relative to placebo in the two groups. The TP group also showed less activation than the NP group in the right middle temporal gyrus and cerebellum, independent of the effects of THC.

Conclusions

In this first demonstration of inter-subject variability in sensitivity to the psychotogenic effects of THC, we found that the presence of acute psychotic symptoms was associated with a differential effect of THC on activation in the ventral and medial temporal cortex and cerebellum, suggesting that these regions mediate the effects of the drug on psychotic symptoms.
Dynamic grasping of an arbitrary polyhedral object
Authors: Kawamura Akihiro , Tahara Kenji , Kurazume Ryo , Hasegawa Tsutomu
Published: October 2012

This paper proposes a novel dynamic stable grasping method of an arbitrary polyhedral object for a hand-arm system with hemispherical fingertips. This method makes it possible to satisfy the force/torque equilibrium condition for the immobilization of the object without knowledge of the object. Two control signals are proposed which generate grasping forces normal and tangential to an object surface in a final state. The dynamics of the overall system is modeled and analyzed theoretically. We demonstrate the stable grasping of an arbitrary polyhedral object using the proposed controller through numerical simulations and experiments using a newly developed mechanical hand-arm system.
Children's referential understanding of novel words and parent labeling behaviors: similarities across children with and without autism spectrum disorders
Authors: HANI HANADY BANI , GONZALEZ-BARRERO ANA MARIA , NADIG APARNA S.
Published: October 2012

This study examined two facets of the use of social cues for early word learning in parent–child dyads, where children had an Autism Spectrum Disorder (ASD) or were typically developing. In Experiment 1, we investigated word learning and generalization by children with ASD (age range: 3;01–6;02) and typically developing children (age range: 1;02–4;09) who were matched on language ability. In Experiment 2, we examined verbal and non-verbal parental labeling behaviors. First, we found that both groups were similarly able to learn a novel label using social cues alone, and to generalize this label to other representations of the object. Children who utilized social cues for word learning had higher language levels. Second, we found that parental cues used to introduce object labels were strikingly similar across groups. Moreover, parents in both groups adapted labeling behavior to their child's language level, though this surfaced in different ways across groups.
On weighted inhomogeneous Diophantine approximation on planar curves
Authors: HUSSAIN MUMTAZ , YUSUPOVA TATIANA
Published: October 2012

This paper develops the metric theory of simultaneous inhomogeneous Diophantine approximation on a planar curve with respect to multiple approximating functions. Our results naturally generalize the homogeneous Lebesgue measure and Hausdorff dimension results for the sets of simultaneously well-approximable points on planar curves, established in Badziahin and Levesley (Glasg. Math. J., 49(2):367–375, 2007), Beresnevich et al. (Ann. of Math. (2), 166(2):367–426, 2007), Beresnevich and Velani (Math. Ann., 337(4):769–796, 2007) and Vaughan and Velani (Invent. Math., 166(1):103–124, 2006).
The chromatic filtration of the Burnside category
Authors: SZYMIK MARKUS
Published: October 2012

The Segal map connects the Burnside category of finite groups to the stable homotopy category of their classifying spaces. The chromatic filtrations on the latter can be used to define filtrations on the former. We prove a related conjecture of Ravenel's in some cases, and present counterexamples to the general statement.
Evolving food retail environments in Thailand and implications for the health and nutrition transition
Authors: Banwell Cathy , Dixon Jane , Seubsman Sam-Ang , Pangsap S , Kelly Matthew , Sleigh Adrian
Published: October 2012

Objective

To investigate evolving food retail systems in Thailand.

Design

Rapid assessment procedures based on qualitative research methods including interviews, focus groups discussions and site visits.

Setting

Seven fresh markets located in the four main regions of Thailand.

Subjects

Managers, food specialists, vendors and shoppers from seven fresh markets who participated in interviews and focus group discussions.

Results

Fresh markets are under economic pressure and are declining in number. They are attempting to resist the competition from supermarkets by improving convenience, food diversity, quality and safety.

Conclusions

Obesity has increased in Thailand at the same time as rapid growth of modern food retail formats has occurred. As fresh markets are overtaken by supermarkets there is a likely loss of fresh, healthy, affordable food for poorer Thais, and a diminution of regional culinary culture, women's jobs and social capital, with implications for the health and nutrition transition in Thailand.
Use of food supplements and determinants of usage in a sample Italian adult population
Authors: Giammarioli Stefania , Boniglia Concetta , Carratù Brunella , Ciarrocchi Marco , Chiarotti Flavia , Mosca Maurizio , Sanzini Elisabetta
Published: October 2012

Objective

The aims were to collect data on consumption of different food supplements in a sample of the adult Italian population and to characterize users by demographic, physical and health-related characteristics, lifestyle and behaviour.

Design

Cross-sectional survey.

Setting

The study was conducted in 2008 in ten towns of Italy (two towns from each of the five macro-areas: Northwest, Northeast, Centre, South and Islands).

Subjects

Adults (n10 000) aged ≥18 years were randomly selected and asked to fill in a self-administered questionnaire regarding their use of food supplements and the above variables. The effect of these variables on food supplement use was evaluated by univariate and multivariate logistic regression.

Results

Of the 1723 individuals who returned the questionnaire, 49 % were users of food supplements. A large proportion (54 %) of users used more than one category of food supplement: vitamin and/or mineral supplements were the most used (61 %), followed by supplements with botanicals and botanical extracts (28 %). The results obtained by logistic regression showed that gender, town size, education level, sports practice, regular use of wholemeal cereal-based foods and presence of a low stress level were determinants for the use of food supplements in the examined population. However, these determinants were not shared by all categories of supplements.

Conclusions

The results of this preliminary study highlight that associations between demographic, dietary and lifestyle factors and use of different categories of food supplements differ according to products, and cannot be accounted for simply by dichotomizing individuals as users or non-users.
Allgemeine Prokrastination
Authors: Klingsieck Katrin Birte , Fries Stefan
Published: October 2012

In der vorliegenden Studie wurde anhand einer Übersetzung der General Procrastination Scale (GPS; Lay, 1986 ) eine deutschsprachige Kurzskala zur Erfassung von allgemeiner Prokrastination entwickelt und validiert. In drei Teilstudien wurden (sprachliche) Äquivalenz, Faktorenstruktur, Reliabilität und Validität untersucht. Die GPS erwies sich als sprachlich äquivalent zum englischen Original (Vorstudie, N = 38). Die Exploration der Faktorenstruktur (Studie I, N = 1 253) lieferte jedoch keine eindeutigen Hinweise auf die Eindimensionalität der GPS. Aufgrund dessen wurde eine eindimensionale Kurzskala (GPS-K) entwickelt und in der letzten Studie (Studie II, N = 218) validiert. Die interne Konsistenz (Studie I, II) sowie die Test-Retest Reliabilität (Studie II) der Kurzskala waren zufriedenstellend. Die konvergente und diskriminante Validität konnte in Bezug auf andere Persönlichkeitsmerkmale gezeigt werden. Anhand eines Verhaltensmaßes konnten weitere Hinweise für die Konstruktvalidität gesammelt werden. Mit der deutschen Übersetzung und Entwicklung der GPS-K liegt demnach ein ökonomisches sowie reliables und valides Instrumente zur Erfassung von allgemeiner Prokrastination vor.
Das Inventar zur Erfassung interpersonaler Motive (IIM)
Authors: Thomas Andrea , Locke Kenneth D. , Strauß Bernhard
Published: October 2012

Diese Arbeit beschreibt die Entwicklung und Validierung des Inventars zur Erfassung interpersonaler Motive (IIM)–eine deutsche Version der Circumplex Scales of interpersonal Values (CSIV, Locke, 2000). Es handelt sich um ein Instrument der Interpersonalen Forschungstradition, d. h. die Struktur des IIM berücksichtigt das theoretische interpersonale Circumplexmodell (IPC) zur Messung interpersonaler Ziele entlang der beiden Dimensionen Agency und Communion. Die acht Skalen zu je acht Items bilden die Oktanten des Kreismodells ab. Anhand klinischer und nicht klinischer Stichproben wird die Validierung des IIM vorgestellt. Das IIM wurde hinsichtlich der psychometrischen und circumplexbezogenen Item- und Skalenparameter, der Konstruktvalidität (Fit mit dem IPC-Modell, Konvergenz bzw. Divergenz zu anderen Messinstrumenten sowie Diskrimination von Patienten der Diagnose Soziale Phobie von einer gesunden Vergleichsgruppe) und der Reliabilität (Cronbachs Alpha, Test-Retest-Reliabilität) geprüft. Das IIM empfiehlt sich gleichermaßen für sozialpsychologische und differentielle Fragestellungen wie für den Einsatz in Psychotherapiestudien.
Drainage subsidence associated with Arctic permafrost degradation
Authors: Lewis K. C. , Zyvoloski G. A. , Travis B. , Wilson C. , Rowland J.
Published: October 2012

Arctic sources of greenhouse gas associated with permafrost degradation constitute a large uncertainty in existing climate models. Greenhouse gas release from the Arctic subsurface is mediated by numerous interconnected physical processes; one facet of these is the interplay between surface deformation and melting of subsurface ice. First, we construct analytic solutions describing fluid drainage and soil subsidence subsequent to thawing of a 1‐D permafrost column. These solutions lead to formulas giving the total amount of subsidence as well as the time over which subsidence occurs. We give an example application of the analytic model to peat plateau degradation in the Canadian Hudson Bay Lowland and show that the degree of subsidence predicted from our model is consistent with recorded subsidence of peat in western Norway that was drained for cultivation purposes. Second, we numerically model an initially frozen, fluid‐saturated, 2‐D soil matrix with a thaw zone advancing from the surface downward. With the surface temperature fixed at 5°C, a thaw front propagates to ∼10 m depth within 20 years, and due primarily to drainage of fluid from the pore space, a region of soil depressed by ∼3 m forms above an initially ice‐rich subsurface zone. Soil underlying this depressed zone may have its permeability reduced by between 1 and 2 orders of magnitude; this reduction in permeability can act as a negative feedback to thawing.
Benjamin P. Flower (1962–2012)
Authors: Hastings David W. , Shevenell Amelia E. , Kennett James P.
Published: October 2012

Benjamin P. Flower, a gifted paleoceanographer and marine geologist, supportive colleague, and dedicated educator at the University of South Florida (USF) College of Marine Science (CMS) passed away on 1 July 2012 from complications related to a rare genetic immune dysfunction, Common Variable Immunodeficiency. He was 49 years old. During his brief illness, Ben's love of life and boundless high spirits were an inspiration to his family, friends, and colleagues. He exhibited remarkable courage and kept his sense of humor in face of adversity. Ben's intellectualism and enduring love of science remained intact, even in his last hours.
New measurements quantify atmospheric greenhouse effect
Authors: Bhattacharya Atreyee
Published: October 2012

In spite of a large body of existing measurements of incoming short‐wave solar radiation and outgoing long‐wave terrestrial radiation at the surface of the Earth and, more recently, in the upper atmosphere, there are few observations documenting how radiation profiles change through the atmosphere—information that is necessary to fully quantify the greenhouse effect of Earth's atmosphere. Through the use of existing technology but employing improvements in observational techniques it may now be possible not only to quantify but also to understand how different components of the atmosphere (e.g., concentration of gases, cloud cover, moisture, and aerosols) contribute to the greenhouse effect. Using weather balloons equipped with radiosondes, Philipona et al. continuously measured radiation fluxes from the surface of Earth up to altitudes of 35 kilometers in the upper stratosphere. Combining data from flights conducted during both day and night with continuous 24‐hour measurements made at the surface of the Earth, the researchers created radiation profiles of all four components necessary to fully capture the radiation budget of Earth, namely, the upward and downward short‐wave and long‐wave radiation as a function of altitude.
Atmospheric carbon dioxide retrieved from the Greenhouse gases Observing SATellite (GOSAT): Comparison with ground‐based TCCON observations and GEOS‐Chem model calculations
Authors: Cogan A. J. , Boesch H. , Parker R. J. , Feng L. , Palmer P. I. , Blavier J.‐F. L. , Deutscher N. M. , Macatangay R. , Notholt J. , Roehl C. , Warneke T. , Wunch D.
Published: October 2012

We retrieved column‐averaged dry air mole fractions of atmospheric carbon dioxide () from backscattered short‐wave infrared (SWIR) sunlight measured by the Japanese Greenhouse gases Observing SATellite (GOSAT). Over two years of retrieved from GOSAT is compared with inferred from collocated SWIR measurements by seven ground‐based Total Carbon Column Observing Network (TCCON) stations. The average difference between GOSAT and TCCON for individual TCCON sites ranges from −0.87 ppm to 0.77 ppm with a mean value of 0.1 ppm and standard deviation of 0.56 ppm. We find an average bias between all GOSAT and TCCON retrievals of −0.20 ppm with a standard deviation of 2.26 ppm and a correlation coefficient of 0.75. One year of was retrieved from GOSAT globally, which was compared to global 3‐D GEOS‐Chem chemistry transport model calculations. We find that the latitudinal gradient, seasonal cycles, and spatial variability of GOSAT and GEOS‐Chem agree well in general with a correlation coefficient of 0.61. Regional differences between GEOS‐Chem model calculations and GOSAT observations are typically less than 1 ppm except for the Sahara and central Asia where a mean difference between 2 to 3 ppm is observed, indicating regional biases in the GOSAT retrievals unobserved by the current TCCON network. Using a bias correction scheme based on linear regression these regional biases are significantly reduced, approaching the required accuracy for surface flux inversions.
Media responsible for Faraday rotation: A review
Authors: Oberoi D. , Lonsdale C. J.
Published: October 2012

Recent technological advances have led to a resurgence of interest in low frequency radio astronomy. Ionospheric distortion of cosmic radiation has, however, been a challenge for high fidelity and high sensitivity measurements at these long wavelengths. Several new and innovative low radio frequency interferometers are currently in varying stages of development, construction and commissioning across the globe. They will pursue a broad range of scientific objectives, and precise ionospheric calibration over the wide field‐of‐view of these new generation instruments will be a prerequisite for achieving these science goals. The task of calibration is made more difficult by the Faraday rotation (FR) of polarized flux as it passes through the magnetized plasma of the ionosphere, the plasmasphere, the magnetosphere, and the heliosphere. To quantify these effects, we present a survey of the order of magnitude of FR associated with these media and their spatial and temporal variations.
Oxygen regulates the band 3–ankyrin bridge in the human erythrocyte membrane
Authors: Stefanovic Marko , Puchulu-Campanella Estela , Kodippili Gayani , Low Philip S.
Published: October 2012

The oxygenation state of erythrocytes is known to impact several cellular processes. As the only known O2-binding protein in red blood cells, haemoglobin has been implicated in the oxygenation-mediated control of cell pathways and properties. Band 3, an integral membrane protein linked to the spectrin/actin cytoskeleton, preferentially binds deoxygenated haemoglobin at its N-terminus, and has been postulated to participate in the mechanism by which oxygenation controls cellular processes. Because the ankyrin-binding site on band 3 is located near the deoxyHb (deoxygenated haemoglobin)-binding site, we hypothesized that deoxyHb might impact the association between band 3 and the underlying erythrocyte cytoskeleton, a link that is primarily established through band 3–ankyrin bridging. In the present paper we show that deoxygenation of human erythrocytes results in displacement of ankyrin from band 3, leading to release of the spectrin/actin cytoskeleton from the membrane. This weakening of membrane–cytoskeletal interactions during brief periods of deoxygenation could prove beneficial to blood flow, but during episodes of prolonged deoxygenation, such as during sickle cell occlusive crises, could promote unwanted membrane vesiculation.
Rezymogenation of active urokinase induced by an inhibitory antibody
Authors: Jiang Longguang , Botkjaer Kenneth A. , Andersen Lisbeth M. , Yuan Cai , Andreasen Peter A. , Huang Mingdong
Published: October 2012

An important regulatory mechanism of serine proteases is the proteolytic conversion of the inactive pro-enzyme, or zymogen, into the active enzyme. This activation process is generally considered an irreversible process. In the present study, we demonstrate that an active enzyme can be converted back into its zymogen form. We determined the crystal structure of uPA (urokinase-type plasminogen activator) in complex with an inhibitory antibody, revealing that the antibody ‘rezymogenizes’ already activated uPA. The present study demonstrates a new regulatory mechanism of protease activity, which is also an extreme case of protein allostery. Mechanistically, the antibody binds a single surface-exposed loop, named the autolysis loop, thereby preventing the stabilization of uPA in its active conformation. We argue that this autolysis loop is a key structural element for rezymogenation of other proteases, and will be a new target site for pharmacological intervention with serine protease activity.
Characterizing Intonation Deficit in Motor Speech Disorders: An Autosegmental–Metrical Analysis of Spontaneous Speech in Hypokinetic Dysarthria, Ataxic Dysarthria, and Foreign Accent Syndrome
Authors: Lowit Anja , Kuschmann Anja
Published: October 2012

Purpose

The autosegmental–metrical (AM) framework represents an established methodology for intonational analysis in unimpaired speaker populations but has found little application in describing intonation in motor speech disorders (MSDs). This study compared the intonation patterns of unimpaired participants (CON) and those with Parkinson’s disease (PD), ataxic dysarthria (AT), and foreign accent syndrome (FAS) to evaluate the approach’s potential for distinguishing types of MSDs from each other and from unimpaired speech.

Method

Spontaneous speech from 8 PD, 8 AT, 4 FAS, and 10 CON speakers were analyzed in relation to inventory and prevalence of pitch patterns, accentuation, and phrasing. Acoustic-phonetic baseline measures (maximum-phonation-duration, speech rate, and F0-variability) were also performed.

Results

The analyses yielded differences between MSD and CON groups and between the clinical groups in regard to prevalence, accentuation, and phrasing. AT and FAS speakers used more rising and high pitch accents than PD and CON speakers. The AT group used the highest number of pitch accents per phrase, and all 3 MSD groups produced significantly shorter phrases than the CON group.

Conclusions

The study succeeded in differentiating MSDs on the basis of intonational performances by using the AM approach, thus, demonstrating its potential for charting intonational profiles in clinical populations.
The Diagnosis and Understanding of Apraxia of Speech: Why Including Neurodegenerative Etiologies May Be Important
Authors: Duffy Joseph R. , Josephs Keith A.
Published: October 2012

Purpose

To discuss apraxia of speech (AOS) as it occurs in neurodegenerative disease (progressive AOS [PAOS]) and how its careful study may contribute to general concepts of AOS and help refine its diagnostic criteria.

Method

The article summarizes our current understanding of the clinical features and neuroanatomical and pathologic correlates of PAOS and its relationship to primary progressive aphasia (PPA). It addresses similarities and differences between PAOS and stroke-induced AOS that may be relevant to improving our understanding of AOS in general.

Conclusions

PAOS is clinical disorder that should be distinguished from PPA. Its recognition is important to clinical care provided by speech-language pathologists, but it also has implications for neurologic localization and diagnosis as well as prediction of underlying pathology and histochemistry. The clinical features of PAOS and stroke-induced AOS have not been explicitly compared, but they may not be identical because PAOS does not follow a vascular distribution, the brunt of cortical pathology is in the premotor and supplementary motor area, and its onset (rather than acute) is slowly progressive with potential for adaptation to gradual impairment. Careful description and study of PAOS may be a valuable source of information for refining our understanding of AOS in general.
Patterns of Impairments in AOS and Mechanisms of Interaction Between Phonological and Phonetic Encoding
Authors: Laganaro Marina
Published: October 2012

Purpose

One reason why the diagnosis of apraxia of speech (AOS) and its underlying impairment are often debated may lie in the fact that most patients do not display pure patterns of AOS. Mixed patterns are clearly acknowledged at other levels of impairment (e.g., lexical–semantic and lexical–phonological), and they have contributed to debate about the degree of interaction between encoding levels; by contrast, mixed impairments and mechanisms of interaction are less acknowledged at the levels of phonological and phonetic processes. Here, the author aims at bringing together empirical evidence in favor of an interaction between phonological and phonetic encoding and of the predominance of mixed patterns of impairment over pure phonetic impairment.

Method

The author reviews empirical results from acoustic and psycholinguistic studies, both with healthy speakers and speakers with brain damage, favoring independent phonological and phonetic encoding and separable impairments as well as recent research pointing to an interaction between phonological and phonetic encoding processes and overlapping patterns of impairments.

Conclusions

Acknowledging interaction between phonological and phonetic processing has clear consequences on the definition of patterns of impairment. In particular, phonetic errors have not necessarily a phonetic origin, and most patterns of impairment are bound to display both phonological and phonetic features.
Apraxia of Speech and Phonological Errors in the Diagnosis of Nonfluent/Agrammatic and Logopenic Variants of Primary Progressive Aphasia
Authors: Croot Karen , Ballard Kirrie , Leyton Cristian E. , Hodges John R.
Published: October 2012

Purpose

The International Consensus Criteria for the diagnosis of primary progressive aphasia (PPA; Gorno-Tempini et al., 2011) propose apraxia of speech (AOS) as 1 of 2 core features of nonfluent/agrammatic PPA and propose phonological errors or absence of motor speech disorder as features of logopenic PPA. We investigated the sensitivity and specificity of AOS and phonological errors as markers for these variants and also investigated the relationship between AOS, phonological errors, and findings on C-labeled Pittsburgh Compound B (PiB)–positron emission tomography (PET) imaging associated with putative Alzheimer-type pathology.

Method

Connected speech and word repetition in 23 people with PPA who underwent PiB-PET imaging were rated for apraxic versus phonological disruption by 1 rater who was blind to diagnosis and by 2 raters who were blind to PiB-PET results.

Results

Apraxic characteristics had high sensitivity for nonfluent/agrammatic PPA, and phonological errors had high sensitivity for logopenic PPA; however, phonological errors showed lower specificity for logopenic PPA. On PiB imaging, 8 of 9 people with predominant AOS returned negative results, whereas participants with no or questionable AOS with and without phonological errors returned positive results.

Conclusions

Attention to AOS and phonological errors may help counter some of the inherent limitations of diagnosis-by-exclusion in the current International Consensus Criteria for diagnosing PPA.
The heads and tails of buoyant autocatalytic balls
Authors: Rogers Michael C. , Morris Stephen W.
Published: October 2012

Buoyancy produced by autocatalytic reaction fronts can produce fluid flows that advect the front position, giving rise to interesting feedback between chemical and hydrodynamic effects. In this paper, we numerically investigate the evolution of autocatalytic iodate-arsenous acid reaction fronts initialized in spherical configurations. Deformation of these “autocatalytic balls” is driven by buoyancy produced by the reaction. In our simulations, we have found that depending on the initial ball radius, the reaction front will develop in one of three different ways. In an intermediate range of ball size, the flow can evolve much like an autocatalytic plume: the ball develops a reacting head and tail that is akin to the head and conduit of an autocatalytic plume. In the limit of large autocatalytic balls, however, growth of a reacting tail is suppressed and the resemblance to plumes disappears. Conversely, very small balls of product solution fail to initiate sustained fronts and eventually disappear.
Transformation of the polarization of THz waves by their reflection and transmission through a finite layered superconductor
Authors: Apostolov S. S. , Rokhmanova T. N. , Khankina S. I. , Yakovenko V. M. , Yampol’skii V. A.
Published: October 2012

The reflection and transmission of terahertz electromagnetic waves propagating in a waveguide through the sample of a layered superconductor of finite length are studied theoretically. The excitation of the two types of Josephson plasma waves, ordinary and extraordinary, in the sample leads to a partial or a complete transformation of the incident wave polarization. The conditions for the complete transformation of polarization are found.
Values of the Krichevskii Parameter, AKr, of Aqueous Nonelectrolytes Evaluated from Relevant Experimental Data
Authors: Plyasunov Andrey V.
Published: October 2012

In dilute near-critical solutions, the partial molar properties of solutes, the coordinates of the critical lines of binary mixtures, and the temperature variations of the vapor–liquid distribution and Henry's constants, are controlled by the critical value of the derivative $(\partial P/\partial x)_{V,T}^{\rm c}$(∂P/∂x)V,Tc, which is called the Kricheskii parameter, AKr. The Krichevskii parameter can be evaluated from various types of data: the initial slopes of the critical line of a binary system, the vapor–liquid distribution constants of solutes, the slopes of the dew and bubble curves near the solvent's critical point, from near-critical variations of $V_2^\infty$V2∞ and ΔhH∞ for solutes. These methods are systematically applied to mixtures of water with 59 inorganic and organic solutes, ranging from inert gases to polyfunctional compounds. For 23 solutes, the evaluation of AKr is possible from more than one type of data, allowing to establish recommended values of the Krichevskii parameter.
Reference Correlation for the Density and Viscosity of Eutectic Liquid Alloys Al+Si, Pb+Bi, and Pb+Sn
Authors: Assael M. J. , Mihailidou E. K. , Brillo J. , Stankus S. V. , Wu J. T. , Wakeham W. A.
Published: October 2012

In this paper, the available experimental data for the density and viscosity of eutectic liquid alloys Al+Si, Pb+Bi, and Pb+Sn have been critically examined with the intention of establishing a reference standard representation of both density and viscosity. All experimental data have been categorized as primary or secondary according to the quality of measurement, the technique employed, and the presentation of the data, as specified by a series of carefully defined criteria. The proposed standard reference correlations for the density of liquid Al+Si, Pb+Bi, and Pb+Sn are, respectively, characterized by deviations of 2.0%, 2.9%, and 0.5% at the 95% confidence level. The standard reference correlations for the viscosity of liquid Al+Si, Pb+Bi, and Pb+Sn are, respectively, characterized by deviations of 7.7%, 14.2%, and 12.4% at the 95% confidence level.
Stirring effects in models of oceanic plankton populations
Authors: Neufeld Zoltan
Published: October 2012

We present an overview and extend previous results on the effects of large scale oceanic transport processes on plankton population dynamics, considering different types of ecosystem models. We find that increasing stirring rate in an environment where the carrying capacity is non-uniformly distributed leads to an overall decrease of the effective carrying capacity of the system. This may lead to sharp regime shifts induced by stirring in systems with multiple steady states. In prey-predator type systems, stirring leads to resonant response of the population dynamics to fluctuations enhancing the spatial variability—patchiness—in a certain range of stirring rates. Oscillatory population models produce strongly heterogeneous patchy distribution of plankton blooms when the stirring is weak, while strong stirring may either synchronise the oscillatory dynamics, when the inhomogeneity is relatively weak, or suppress oscillations completely (oscillator death) by reducing the effective carrying capacity below the bifurcation point.
Iron-based superconductors: Magnetism, superconductivity, and electronic structure (Review Article)
Authors: Kordyuk A. A.
Published: October 2012

Angle resolved photoemission spectroscopy (ARPES) reveals the features of the electronic structure of quasi-two-dimensional crystals which are crucial for spin and charge ordering and determine the mechanisms of electron–electron interactions, including superconducting pairing. The newly discovered iron-based superconductors (FeSC) promise interesting physics stemming, on one hand, from a coexistence of superconductivity and magnetism and, on the other, from a complex multi-band electronic structure. In this review I want to offer a simple introduction to the physics of FeSC, and to argue that all the complexity of FeSC properties is encapsulated in their electronic structure. For many compounds, this structure has been determined on the basis of numerous ARPES experiments and agrees reasonably well with the results of band structure calculations. Nevertheless, the existing small differences may help to understand the mechanisms of magnetic ordering and superconducting pairing in FeSC.
Time-dependent importance sampling in semiclassical initial value representation calculations for time correlation functions. II. A simplified implementation
Authors: Tao Guohua , Miller William H.
Published: October 2012

An efficient time-dependent (TD) Monte Carlo (MC) importance sampling method has recently been developed [G. Tao and W. H. Miller, J. Chem. Phys. 135, 024104 (2011)10.1063/1.3600656] for the evaluation of time correlation functions using the semiclassical (SC) initial value representation (IVR) methodology. In this TD-SC-IVR method, the MC sampling uses information from both time-evolved phase points as well as their initial values, and only the “important” trajectories are sampled frequently. Even though the TD-SC-IVR was shown in some benchmark examples to be much more efficient than the traditional time-independent sampling method (which uses only initial conditions), the calculation of the SC prefactor—which is computationally expensive, especially for large systems—is still required for accepted trajectories. In the present work, we present an approximate implementation of the TD-SC-IVR method that is completely prefactor-free; it gives the time correlation function as a classical-like magnitude function multiplied by a phase function. Application of this approach to flux-flux correlation functions (which yield reaction rate constants) for the benchmark H + H2 system shows very good agreement with exact quantum results. Limitations of the approximate approach are also discussed.
Synchrotron x-ray modification of nanoparticle superlattice formation
Authors: Lu Chenguang , Akey Austin J. , Herman Irving P.
Published: October 2012

The synchrotron x-ray radiation used to perform small angle x-ray scattering (SAXS) during the formation of three-dimensional nanoparticle superlattices by drop casting nanoparticle solutions affects the structure and the local crystalline order of the resulting films. The domain size decreases due to the real-time SAXS analysis during drying and more macroscopic changes are visible to the eye.
Coherence and decoherence in the brain
Authors: Hepp K.
Published: October 2012

This review provides many entry points to controversies in neuroscience, where input from mathematical physics could be fruitful, especially about coherence and decoherence in the brain, both on the level of classical and quantum mechanics.