bluuebunny/crossref_metadata_2025 huggingface dataset:
Exostosis in the Hand: Case Series and Literature Review
Authors: Sze-Yan Chan , Fu-Keung Ip , Tak-Cheun Wong , Siu-Ho Wan
Published: November 2012

Introduction

This study reviews the exostosis in hand in our locality and compares those in the literature.

Methods

A retrospective study was conducted by reviewing the cases collected from 2000 to 2010. Literatures were also reviewed to look into the current concept of exostosis in the hand.

Results

There were nine patients with a total of 11 lesions of exostosis in the hand. Two cases were parosteal osteochondroma (Nora lesion). The male to female ratio was 4:5. The average presented age at the first consultation was 49.7 years of age. The most common site was distal phalanx. Six lesions had incorrect preoperative diagnoses by clinical assessment and standard two-view radiographs of the hand. Three of the six lesions were corrected after intraoperative Xi-scan screening.

Conclusion

The clinical picture of exostosis in the hand in our locality seems to be different from that of Western countries. Lesions of the hand were difficult to be visualized in the radiographs due to overlapping of bones. Xi-scan may help in making the diagnosis.
Integrating a Trauma Lens into a Family Therapy Framework: Ten Principles for Family Therapists
Authors: James Kerrie , MacKinnon Laurie
Published: November 2012

This paper aims to show how a trauma lens can be incorporated into existing family therapy practices, changing how therapists perceive presenting problems and therefore the issues and sites of intervention. After reviewing the family therapy literature concerning trauma and defining different types of trauma, the paper discusses how traumatic memories differ from ordinary memories. Ten principles for practice are described to guide therapists in integrating the trauma lens into their family therapy practice. Three case studies are used to illustrate these principles.
The Neurosequential Model of Therapeutics: An Interview with Bruce Perry
Authors: MacKinnon Laurie
Published: November 2012

In this interview with Bruce Perry, MD, PhD, Senior Fellow of The Child Trauma Academy, Laurie MacKinnon discusses with Dr Perry developmental trauma and the Neurosequential Model of Therapeutics, an approach to clinical problem solving that utilises a developmental lens and incorporates advances in neurobiological development. Dr Perry gives his perspective on the causal connection between childhood abuse and later psychiatric diagnosis, the child's contact with a violent parent post‐separation, the importance of interventions that address the organisation and functioning of lower parts of the brain and his perspective on the use and limitations of psychotropic medications, cognitive behaviour therapy and family therapy.
Trauma and Bowen Family Systems Theory: Working with Adults Who were Abused as Children
Authors: MacKay Linda
Published: November 2012

Working with survivors of trauma is mostly challenging, exhausting, long‐term and often ‘messy’, when interventions that ‘should’ work, don't, or the unexpected arises. Nevertheless, explanations that speak to recovery from trauma more and more rely on neurobiological concepts to account for any positive change. Combining the family systems approach of Murray Bowen and recent research on the brain and trauma, post trauma symptoms are viewed as part of the ‘family emotional process’ even when traumatic events have emanated from outside the family system itself. Variations in responses to trauma, including dissociation and self‐harm are discussed in relation to chronic anxiety and ‘differentiation of self’.
Therapeutic Responses to Communities Affected by Disasters: The Contribution of Family Therapy
Authors: Breckenridge Jan , James Kerrie
Published: November 2012

This article is underpinned by the premise that for recovery, healing and post‐traumatic growth to occur after traumatic events such as technological and natural disasters, massacres and terrorist attacks, effective therapeutic services need to be offered at both the individual and community level. Frequently, responses to such traumatic instances have been conceptualised as discrete, polarised interventions offered by various groups of health and welfare professionals at various points post the traumatic event. Traditionally when therapeutic interventions are considered, many practitioners assume that the response would, and should, focus primarily and narrowly, on individuals or their families and the symptoms of post‐traumatic stress. Conversely, the perceived role of community wide interventions has been unnecessarily limited to disaster relief or organised emergency responses most usually offered at the time of the crisis. The consequence of these limited understandings is an apparent failure to explore fully the therapeutic or mediating role of social or community support in surviving trauma. Interventions encompassing the level of community might be therapeutic in two fundamental ways. First, if practitioners embraced ideas from systemic family therapy literature, ideas that acknowledge the importance of social networks, this would encourage a more holistic vision of resilience and recovery. Second, if practitioners recognised that whole communities and social networks might also be traumatised, they could provide support and interventions oriented toward healing at this broader level.
PLANT GROWTH-PROMOTING BACTERIAL ENDOPHYTES FROM SUGARCANE AND THEIR POTENTIAL IN PROMOTING GROWTH OF THE HOST UNDER FIELD CONDITIONS
Authors: CHAUHAN HEMLATA , BAGYARAJ D. J. , SHARMA ANITA
Published: November 2012

Ten endophytic bacteria were isolated from different sugarcane varieties growing in the Crop Research Centre, Pantnagar on nitrogen-free medium. Plant growth-promoting potential of the isolates was reported in terms of indole acetic acid (IAA) production, phosphorus solubilization, siderophore production and antagonistic action against the pathogenColletotrichum falcatum, which causes red rot disease in sugarcanein vitro. All the isolates were able to produce IAA (4.8–9 μg ml−1); three isolates (H3, H5 and H14) solubilized insoluble phosphorus on Pikovaskaya's agar; two isolates (H10 and H14) showed siderophore production on Chrome-azurol S (CAS) agar and antagonism againstC. falcatumwas exhibited by two isolates (H14 and H15) in a dual plate assay. 16 S rRNA sequencing identified isolates H3 and H12 asPseudomonasspp., and H8, H14 and H15 asBacillusspp. A field experiment on sugarcane was conducted with five plant growth-promoting bacterial endophytesPseudomonasspp. (H3 and H12) andBacillusspp. (H8, H14 and H15) along with standard strains ofGluconacetobacterandAzospirillumspp. Plant height, chlorophyll content, total nitrogen and cane length were significantly higher in almost all inoculated plants compared with the uninoculated control. An increase of 40% in cane yield over the control was obtained after inoculation with isolate H15 (Bacillusspp.). This was statistically on par with the standard endophyteGluconacetobacter diazotrophicus, which resulted in 42% increased cane yield. Identification of new diazotrophs and their promising results towards improving plant growth in the field suggest their use as inoculants in future.
A link between male sperm whales,Physeter macrocephalus, of the Azores and Norway
Authors: Steiner Lisa , Lamoni Luca , Acosta Plata Marta , Jensen Silje-Kristin , Lettevall Erland , Gordon Jonathan
Published: November 2012

Little is known about the movements of male sperm whales,Physeter macrocephalus, in the North Atlantic. Recoveries of traditional harpoons and tags during commercial whaling indicated movements from Nova Scotia to Spain and from the Azores to Iceland and Spain. We compared collections of photo-identification images from different areas using the North Atlantic and Mediterranean Sperm Whale Catalogue and the Eurphlukes Phlex/Match programs. The largest collections of identified males (number of individuals, start and end date for data collection shown in parentheses) are for the Azores (297, 1987–2008), Andenes (375, 1988–1996 and 2008), Tromsø (84, 2005–2008). There were six matches between Andenes and Tromsø (~25 nm), with three of these re-sighted in multiple years and three photo-identification matches from the Azores to Norway (~2400 nm). In all cases individuals first photographed in the Azores (in 1993, 1999 and 2003) were matched to images collected later in Tromsø (in 2007 and 2008). In 1997 a photo-identification image from Andenes matched a male stranded on the west coast of Ireland. No matches were made to images in smaller collections from Iceland, Nova Scotia, Greenland, Dominica, Guadeloupe, Gulf of Mexico and the Mediterranean. These findings show the value of data collected from whale watching vessels and the importance of collaboration between groups to allow investigation on an ocean basin scale. It is hoped that with the coordinated collection of more images from around the Atlantic, further insight might be gained into the movements of these widely ranging animals.
Helminth communities of fish as ecological indicators of lake health
Authors: SHAH HUMAIRA BASHIR , YOUSUF A. R. , CHISHTI M. Z. , AHMAD FAYAZ
Published: November 2012

This paper deals largely with the dynamics and changes in the helminth parasite communities of fish along the trophic gradient of lakes. The use of parasitological community data as a bioindicator of environmental health underlines the need to study parasite communities at comparable localities with known pollution levels. The comparison of the conditions in different habitats might be helpful to differentiate between normal fluctuations in ambient conditions and pollution-mediated effects. Therefore, the present study was designed to examine the community structure of parasites in snow trout (Schizothorax niger Heckel) inhabiting 3 lakes of contrasting trophic status in Kashmir. The idea of selecting the lakes, namely Anchar (strongly hypereutrophic), Dal (eutrophic) and Manasbal (mesotrophic) for this study was intentional as they depict different trophic gradients and exhibit the desirable pattern which was a prerequisite for this study. The findings presented in this article suggest an apparent lake-wise gradient in community structure, as the increase in trematode and cestode infections in Anchar was markedly greater, to levels clearly distinguishable from those in the other two water bodies. We conclude that human-induced eutrophication of lakes modifies the parasite community at component level and community-level studies on parasites may provide information on health status of lakes.
Viability of Ascaris suum eggs in stored raw and separated liquid slurry
Authors: KATAKAM KIRAN KUMAR , ROEPSTORFF ALLAN , POPOVIC OLGA , KYVSGAARD NIELS C. , THAMSBORG STIG MILAN , DALSGAARD ANDERS
Published: November 2012

Separation of pig slurry into solid and liquid fractions is gaining importance as a way to manage increasing volumes of slurry. In contrast to solid manure and slurry, little is known about pathogen survival in separated liquid slurry. The viability of Ascaris suum eggs, a conservative indicator of fecal pollution, and its association with ammonia was investigated in separated liquid slurry in comparison with raw slurry. For this purpose nylon bags with 6000 eggs each were placed in 1 litre bottles containing one of the two fractions for 308 days at 5 °C or 25 °C. Initial analysis of helminth eggs in the separated liquid slurry revealed 47 Ascaris eggs per gramme. At 25 °C, egg viability declined to zero with a similar trend in both raw slurry and the separated liquid slurry by day 308, a time when at 5 °C 88% and 42% of the eggs were still viable in separated liquid slurry and raw slurry, respectively. The poorer survival at 25 °C was correlated with high ammonia contents in the range of 7·9–22·4 mm in raw slurry and 7·3–23·2 mm in liquid slurry compared to 3·2–9·5 mm in raw slurry and 2·6–9·5 mm in liquid slurry stored at 5 °C. The study demonstrates that at 5 °C, A. suum eggs have a higher viability in separated liquid slurry as compared to raw slurry. The hygiene aspect of this needs to be further investigated when separated liquid slurry is used to fertilize pastures or crops.
CrypticOnchocercaspecies infecting North American cervids, with implications for the evolutionary history of host associations inOnchocerca
Authors: McFREDERICK QUINN S. , HASELKORN TAMARA S. , VEROCAI GUILHERME G. , JAENIKE JOHN
Published: November 2012

Parasites in the genusOnchocercainfect humans, ruminants, camels, horses, suids, and canids, with effects ranging from relatively benign to debilitating. In North America,Onchocerca cervipedisis the sole species known to infect cervids, while at least 5Onchocercaspecies infect Eurasian cervids. In this study, we report the discovery of a cervid-parasitizingOnchocercaonly distantly related toO. cervipedis. To reconstruct the phylogenetic history of the genusOnchocerca, we used newly acquired DNA sequence fromO. cervipedis(from moose in Northwest Territories, Canada) and from the newly discovered species (from white-tailed deer in upstate New York), as well as previously published sequences. Ancestral host reconstructions suggest that host switches have been common throughout the evolutionary history ofOnchocerca, and that bovid- and cervid-parasitizing species have been particularly important sources of descendant species. North America cervids might therefore serve as a source forOnchocercainvasions into new hosts. Given the high density of deer populations, the potential for zoonotic infections may also exist. Our discovery of a newOnchocercaspecies with relatively limited sampling suggests that the diversity ofOnchocercaassociated with cervids in North America may be greater than previously thought, and surveys utilizing molecules and morphology are necessary.
The duration and timing of maternal depression as a moderator of the relationship between dependent interpersonal stress, contextual risk and early child dysregulation
Authors: Barker E. D.
Published: November 2012

Background

Risk factors that are associated with depression in the mother also negatively affect the child. This research sought to extend current knowledge by examining the duration and timing of maternal depression as a moderator of: (1) the impact of dependent interpersonal stress (DIS), such as partner conflict or low social support, and contextual risk (e.g. poverty) on child dysregulation; and (2) continuity in early child dysregulation.

Method

Mother–child pairs (n = 12 152) who participated in the Avon Longitudinal Study of Parents and Children (ALSPAC) were examined between pregnancy and age 4 years. Data on maternal depression were collected five times between pregnancy and 33 months postpartum; on DIS and contextual risk three times between pregnancy and 33 months; and on child dysregulation at age 2 and 4 years.

Results

Longitudinal latent class analysis identified a class of mothers (10%) who evinced a chronic level of depression between pregnancy and 33 months. For chronic-depressedversusnon-depressed mothers, the results indicate that: (1) DIS predicted higher child dysregulation if experienced between pregnancy and age 2; (2) contextual risk had a differential effect on child dysregulation if experienced during pregnancy; and (3) children had higher continuity in dysregulation between age 2 and age 4.

Conclusions

Assessing the impact of the timing and duration of maternal depression, and different types of co-occurring risk factors, on child well-being is important. Maternal depression and associated DIS, in comparison to contextual risk, may be more responsive to intervention.
Developmental changes in children's comprehension and explanation of spatial metaphors for time
Authors: STITES LAUREN J. , ÖZÇALIŞKAN ŞEYDA
Published: November 2012

Time is frequently expressed with spatial motion, using one of three different metaphor types: moving-time, moving-ego, and sequence-as-position. Previous work shows that children can understand and explain moving-time metaphors by age five (Özçalışkan, 2005). In this study, we focus on all three metaphor types for time, and ask whether metaphor type has an effect on children's metaphor comprehension and explanation abilities. Analysis of the responses of three- to six-year-old children and adults showed that comprehension and explanation of all three metaphor types emerge at an early age. Moreover, children's metaphor comprehension and explanation vary by metaphor type: children perform better in understanding and explaining metaphors that structure time in relation to the observer of time (moving-ego, moving-time) than metaphors that structure time without any relation to the observer of time (sequence-as-position-on-a-path). Our findings suggest that children's bodily experiences might play a role in their developing understanding of the abstract concept of time.
A Shiga toxin-producingEscherichia coliO157 outbreak associated with consumption of rice cakes in 2011 in Japan
Authors: NABAE K. , TAKAHASHI M. , WAKUI T. , KAMIYA H. , NAKASHIMA K. , TANIGUCHI K. , OKABE N.
Published: November 2012

In May 2011, an outbreak of Shiga toxin-producingEscherichia coli(STEC) O157 was reported from Yamagata Prefecture, Japan. Investigations, including a case-control study, revealed that the outbreak was linked to two varieties of rice cakes produced by a local manufacturer between 2 and 7 May. Active and passive surveillance identified 136 suspected cases, 142 confirmed cases, 26 asymptomatic cases, and 25 secondary cases. While no environmental samples taken from the manufacturing premises tested positive for STEC, other than a stool sample taken from one employee, on-site and epidemiological investigations indicated that STEC was introduced during the manufacturing process of rice cakes rather than through contamination of raw materials. This was the first reported outbreak of STEC associated with cakes and confectionery in Japan, which indicates that contamination and outbreaks of STEC can occur in any food unless proper precautions are taken.
An insider's look at LF type reconstruction: everything you (n)ever wanted to know
Authors: PIENTKA BRIGITTE
Published: November 2012

Although type reconstruction for dependently typed languages is common in practical systems, it is still ill-understood. Detailed descriptions of the issues around it are hard to find and formal descriptions together with correctness proofs are non-existing. In this paper, we discuss a one-pass type reconstruction for objects in the logical framework LF, describe formally the type reconstruction process using the framework of contextual modal types, and prove correctness of type reconstruction. Since type reconstruction will find most general types and may leave free variables, we in addition describe abstraction which will return a closed object where all free variables are bound at the outside. We also implemented our algorithms as part of the Beluga language, and the performance of our type reconstruction algorithm is comparable to type reconstruction in existing systems such as the logical framework Twelf.
Are subjective cognitive complaints relevant in preclinical Alzheimer's disease? A review and guidelines for healthcare professionals
Authors: Mark Ruth E , Sitskoorn Margriet M
Published: November 2012

Identifying what makes people vulnerable to developing Alzheimer's disease (AD) is at the forefront of many research programmes, while early diagnosis is the goal in clinical practice. What individuals themselves tell their general practitioners (GPs) is clearly important because these subjective complaints may be a clue that something is wrong. More specifically, subjective cognitive complaints (SCC) may be the first sign of AD in individuals whose cognitive performance on standard neuropsychological tasks is normal for their age. The challenge for researchers in this field is twofold: (a) determining when SCC do or do not predict current cognitive functioning and future dementia; and (b) estimating how relevant they are for patients and their proxies. The current article addresses these issues, while guidelines are also provided in an attempt to help clinicians interpret and make treatment decisions about their patients’ SCC.
Twin Database of the Secondary School Attached to the Faculty of Education of the University of Tokyo: Lifecourse Database of Twins
Authors: Ooki Syuichi
Published: November 2012

This article profiles the historical twin databases of the secondary education school attached to the Faculty of Education at the University of Tokyo. The school was established in 1948. Every year, about 50 pairs of twins of all sex and zygosity combinations and aged 11–12 years take an examination, and about 10–20 pairs are admitted based on the results. Three data sets exist: one for applicants (11–12 years), one for junior and senior high school students (12–18 years), and one for graduates (18–79 years). Record linkage of these three databases should facilitate several important research projects; for example, the lifecourse genetic epidemiologic studies and verification of so-called developmental origin of health and disease hypothesis.
Japanese Database of Families with Twins and Higher-Order Multiples
Authors: Ooki Syuichi
Published: November 2012

To gain widespread participation, epidemiologic studies of twins from pregnancy through the childhood period are expected to reflect the needs and concerns of families and provide participants with appropriate and useful feedback based on scientific evidence. Our most recent database on families with twins throughout Japan is based on a questionnaire survey conducted from January 2010 to August 2011. Mailed or hand-delivered questionnaires, consisting of over 550 items were used to collect the basic data. The response rate was 40% (956/2,401). This is part of a nation-wide study designed to assess the long-term effect of perinatal conditions on mothers of multiples. Its aim was to study the growth and development of multiples in childhood, and to conduct a genetic epidemiologic study to test the developmental origin of health and disease hypothesis. One of the ultimate aims of this research was to provide evidence-based information on parenting multiples from pregnancy through childhood to families with multiples.
Individual Differences in Mental Rotation
Authors: Khooshabeh Peter , Hegarty Mary , Shipley Thomas F.
Published: November 2012

Two experiments tested the hypothesis that imagery ability and figural complexity interact to affect the choice of mental rotation strategies. Participants performed the Shepard and Metzler (1971) mental rotation task. On half of the trials, the 3-D figures were manipulated to create “fragmented” figures, with some cubes missing. Good imagers were less accurate and had longer response times on fragmented figures than on complete figures. Poor imagers performed similarly on fragmented and complete figures. These results suggest that good imagers use holistic mental rotation strategies by default, but switch to alternative strategies depending on task demands, whereas poor imagers are less flexible and use piecemeal strategies regardless of the task demands.
Investigating the Mechanisms of Cultural Acquisition
Authors: Flynn Emma , Smith Kenny
Published: November 2012

High-fidelity copying is critical to the acquisition of culture. However, young children’s high-fidelity imitation can result in overimitation, the copying of instrumentally irrelevant actions. We present a series of studies investigating whether adults too overimitate. Experiment 1 found that adults do overimitate, even when evaluation pressures were reduced (Experiment 2) and when participants were faced with a time pressure involving a monetary reward (Experiment 3). Only when participants were presented with a demonstration by someone they believed to be a fellow participant (Experiment 4) did less than half of them overimitate. Thus, overimitation appears to be a robust, adaptive process allowing the acquisition of new information in unfamiliar settings.
Processes of Emotion Communication and Control
Authors: Crowe Michelle , Raval Vaishali V. , Trivedi Shwetang S. , Daga Suchi S. , Raval Pratiksha H.
Published: November 2012

Emotional expression and experience are dynamic processes that vary within and between individuals of different cultural groups ( Kitayama, Mesquita, & Karasawa, 2006 ). The present study sought to compare self-reports of processes related to emotion communication and control in India and the United States. A total of 268 participants (United States: n = 160 and India: n = 108) completed a self-report measure depicting hypothetical vignettes and a series of questions assessing likely emotions elicited, likelihood of expression, motives guiding expression and control, and method of expression. Results showed that US participants primarily reported more self-focused emotions (i.e., happiness) and self- and other-focused motives for expressing or controlling felt emotion, while Indian participants primarily reported emotions that focused on others’ well-being as well as other- and relationship-focused motives. US participants more commonly reported direct verbal communication of the emotion, while Indian participants more frequently reported implicit and contextual methods of communication.
The Duchenne Marker is Not a Universal Signal of Smile Authenticity – But it Can Be Learned!
Authors: Thibault Pascal , Levesque Manon , Gosselin Pierre , Hess Ursula
Published: November 2012

The Duchenne marker has been proposed as a universal marker of smile authenticity. However, Elfenbein, Beaupré, Levesque, and Hess (2007 ) found that, whereas Canadians typically show the Duchenne marker when posing happiness, Gabonese do not. We therefore investigated whether the Duchenne marker is perceived as a marker of smile authenticity by Gabonese and by Mainland Chinese living in Quebec, Canada. The results show that Gabonese do not use the Duchenne marker to assess smile authenticity at all. Mainland Chinese immigrants to Quebec showed sensitivity to the Duchenne marker only when judging smiles by French-Canadian encoders, suggesting learning of the use of this cultural dialect through cultural exposure. In sum, the use of Duchenne marker is not universal, but rather limited to certain cultures.
Mother or Wife?
Authors: Salter Phia S. , Adams Glenn
Published: November 2012

Inspired by “Mother or Wife” African dilemma tales, the present research utilizes a cultural psychology perspective to explore the dynamic, mutual constitution of personal relationship tendencies and cultural-ecological affordances for neoliberal subjectivity and abstracted independence. We administered a resource allocation task in Ghana and the United States to assess the prioritization of conjugal/nuclear relationships over consanguine/kin relationships along three dimensions of sociocultural variation: nation (American and Ghanaian), residence (urban and rural), and church membership (Pentecostal Charismatic and Traditional Western Mission). Results show that tendencies to prioritize nuclear over kin relationships – especially spouses over parents – were greater among participants in the first compared to the second of each pair. Discussion considers issues for a cultural psychology of cultural dynamics.
Centrifugally stimulated exospheric ion escape at Mercury
Authors: Delcourt D. C. , Seki K. , Terada N. , Moore T. E.
Published: November 2012

We investigate the transport of ions in the low‐altitude magnetosphere of Mercury. We show that, because of small spatial scales, the centrifugal effect due to curvature of theE × Bdrift paths can lead to significant particle energization in the parallel direction. We demonstrate that because of this effect, ions with initial speed smaller than the escape speed such as those produced via thermal desorption can overcome gravity and escape into the magnetosphere. The escape route of this low‐energy exosphere originating material is largely controlled by the magnetospheric convection rate. This escape route spreads over a narrower range of altitudes when the convection rate increases. Bulk transport of low‐energy planetary material thus occurs within a limited region of space once moderate magnetospheric convection is established. These results suggest that, via release of material otherwise gravitationally trapped, theE × B related centrifugal acceleration is an important mechanism for the net supply of plasma to the magnetosphere of Mercury.
Ionospheric outflow and cross polar cap potential: What is the role of magnetospheric inflation?
Authors: Welling D. T. , Zaharia S. G.
Published: November 2012

Reductions of the ionospheric cross polar cap potential in magnetohydrodynamic models that include polar wind‐like heavy ion outflow have become a ubiquitous observation in recent studies. The underlying mechanisms for these reductions, which are not to be confused with the problem of potential saturation, remain in question. A possible explanation is that such outflow inflates the magnetosphere, creating a blunter obstacle to the solar wind and reducing the upstream geoeffective length. Such an explanation is attractive because it describes the outflow‐related potential drop in clear, model‐independent terms. This study uses three separate magnetohydrodynamic simulations to test this hypothesis: one coupled to a polar wind outflow model, one coupled to an inner magnetosphere code in order to reproduce the effect without explicit outflow, and a stand‐alone baseline simulation. It is found that this hypothesis cannot explain the total reduction. Results suggest that other mechanisms, such as a change to the dayside reconnection rate, may be important, but further investigation is required.
Birth and life of auroral arcs embedded in the evening auroral oval convection: A critical comparison of observations with theory
Authors: Haerendel G. , Frey H. U. , Chaston C. C. , Amm O. , Juusola L. , Nakamura R. , Seran E. , Weygand J. M.
Published: November 2012

We present and analyze data on auroral arcs obtained during a pass of the FAST satellite over the field‐of‐view of the all‐sky camera at Ft. Simpson (Canada), supported by ground‐based magnetometer and SuperDARN radar data, and plasma data from THEMIS‐A near the source region of the auroral currents. The auroral event took place at 19:00 MLT during substorm activity further east. Active auroral arcs were present over six degrees in latitude moving equatorward with significant changes in brightness and structure. New arcs were forming continuously at the polar border of the auroral oval which was marked by an Alfvénic arc. The data analysis revealed that the equatorward drift of the arcs was in part due to convective motion of the plasma frame but was rather dominated by proper motions of the arcs. Interpretation of these findings in the framework of theoretical work by one of the authors reproduces quantitatively the observed proper motion as a consequence of the progressive erosion of magnetic shear stresses. Most important was the possibility to deduce the interaction time scale between arc and source region. On average it corresponded to about six to eight transit times of an Alfvén wave between arc and source plasma or two fundamental eigenperiods of toroidal mode or azimuthally polarized Alfvén waves. However, large variations of the interaction times and corresponding proper motions were found. They are attributed to temporal and spatial variations of the energy input from the source plasma. The more remarkable is the fact that analysis on the basis of a quasi‐stationary model produces consistent results. The progressive release of shear stresses during the equatorward motion of the arcs leads to the conclusion that they are dying after having reached the maximum of the poleward Pedersen current.
Sensitivity of Nd isotopic composition in seawater to changes in Nd sources and paleoceanographic implications
Authors: Rempfer J. , Stocker Thomas F. , Joos Fortunat , Dutay Jean‐Claude
Published: November 2012

It has been argued that past changes in the sources of Nd could hamper the use of the Nd isotopic composition (ϵNd) as a proxy for past changes in the overturning of deep water masses. Here we reconsider uncertainties associated with ϵNd in seawater due to potential regional to global scale changes in the sources of Nd by applying a modeling approach. For illustrative purposes we describe rather extreme changes in the magnitude of source fluxes, their isotopic composition or both. We find that the largest effects on ϵNd result from changes in the boundary source. Considerable changes also result from variations in the magnitude or ϵNd of dust and rivers but are largely constrained to depths shallower than 1 km, except if they occur in or upstream of regions where deep water masses are formed. From these results we conclude that changes in Nd sources have the potential to affect ϵNd. However, substantial changes are required to generate large‐scale changes inϵNd in deep water that are similar in magnitude to those that have been reconstructed from sediment cores or result from changes in meridional overturning circulation in model experiments. Hence, it appears that a shift in ϵNdcomparable to glacial‐interglacial variations is difficult to obtain by changes in Nd sources alone, but that more subtle variations can be caused by such changes and must be interpreted with caution.
Composition and fluxes of freshwater through Davis Strait using multiple chemical tracers
Authors: Azetsu‐Scott Kumiko , Petrie Brian , Yeats Philip , Lee Craig
Published: November 2012

Freshwater transport through Davis Strait can supply additional buoyancy to the deep convection region of the Labrador Sea which influences the strength of the meridional overturning circulation and consequently the global climate. The freshwater contribution from local sea ice meltwater, meteoric water (fluvial, glaciofluvial and precipitation) and the Arctic outflow were quantified using oxygen isotope composition (δ18O), salinity and nutrient relationships in September–October, 2004. Freshwater transported by the Arctic outflow was isolated using a modified nutrient relationship method and further deconvoluted into sea ice meltwater, meteoric water and Pacific water. For the first time, fluxes of individual freshwater components were estimated using observations of the velocity field derived from mooring arrays and geostrophic currents from hydrography. The Arctic outflow dominated in western Davis Strait (>60%) and its influence extended eastward close to the Greenland Slope. The sea ice meltwater fraction was small (<2%) and limited to the surface layer of the central and western Strait. The meteoric water fraction was highest on the Greenland Shelf (>6%) and attributed to glacial meltwater. The freshwater inventory of the 0–100 m layer was equivalent to 7.4 m in western Davis Strait: 8 m from the Arctic outflow and −0.6 m from brine rejection. In eastern Davis Strait, the freshwater inventory was 4 m: 3 m from meteoric water and 1 m from sea ice meltwater. The Arctic outflow contributed 82–99 mSv to the southward freshwater transport about 67–81% of the total; glacial meltwater contributed the largest northward transport of 10–30 mSv.
Modeling MESSENGER observations of calcium in Mercury's exosphere
Authors: Burger Matthew H. , Killen Rosemary M. , McClintock William E. , Vervack Ronald J. , Merkel Aimee W. , Sprague Ann L. , Sarantos Menelaos
Published: November 2012

The Mercury Atmospheric and Surface Composition Spectrometer (MASCS) on the MESSENGER spacecraft has made the first high‐spatial‐resolution observations of exospheric calcium at Mercury. We use a Monte Carlo model of the exosphere to track the trajectories of calcium atoms ejected from the surface until they are photoionized, escape from the system, or stick to the surface. This model permits an exploration of exospheric source processes and interactions among neutral atoms, solar radiation, and the planetary surface. The MASCS data have suggested that a persistent, high‐energy source of calcium that was enhanced in the dawn, equatorial region of Mercury was active during MESSENGER's three flybys of Mercury and during the first seven orbits for which MASCS obtained data. The total Ca source rate from the surface varied between 1.2 × 1023 and 2.6 × 1023 Ca atoms s−1, if its temperature was 50,000 K. The origin of this high‐energy, asymmetric source is unknown, although from this limited data set it does not appear to be consistent with micrometeoroid impact vaporization, ion sputtering, electron‐stimulated desorption, or vaporization at dawn of material trapped on the cold nightside.
Angular momentum budget in General Circulation Models of superrotating atmospheres: A critical diagnostic
Authors: Lebonnois Sébastien , Covey Curt , Grossman Allen , Parish Helen , Schubert Gerald , Walterscheid Richard , Lauritzen Peter , Jablonowski Christiane
Published: November 2012

To help understand the large disparity in the results of circulation modeling for the atmospheres of Titan and Venus, where the whole atmosphere rotates faster than the surface (superrotation), the atmospheric angular momentum budget is detailed for two General Circulation Models (GCMs). The LMD GCM is tested for both Venus (with simplified and with more realistic physical forcings) and Titan (realistic physical forcings). The Community Atmosphere Model is tested for both Earth and Venus with simplified physical forcings. These analyses demonstrate that errors related to atmospheric angular momentum conservation are significant, especially for Venus when the physical forcings are simplified. Unphysical residuals that have to be balanced by surface friction and mountain torques therefore affect the overall circulation. The presence of topography increases exchanges of angular momentum between surface and atmosphere, reducing the impact of these numerical errors. The behavior of GCM dynamical cores with regard to angular momentum conservation under Venus conditions provides an explanation of why recent GCMs predict dissimilar results despite identical thermal forcing. The present study illustrates the need for careful and detailed analysis of the angular momentum budget for any GCM used to simulate superrotating atmospheres.
Lateral circulation in a stratified open channel on a 120° bend
Authors: Williamson N. , Norris S. E. , Armfield S. W. , Kirkpatrick M. P.
Published: November 2012

We present direct numerical simulation results for both isothermal and density‐stratified turbulent flow in an open channel into and around a 120° bend with a bulk Reynolds number of 7500 and Prandtl number of 1.5. The bend is sharp with a radius‐to‐channel breadth ratio of 1.5. The bulk Richardson number for the stratified flow is 2.4 based on overall channel depth. The gradient Richardson number (Rig) varies between 10 and 20 at the entrance to θ ≈ 60°, where θ is the angular location. Above θ ≈ 60 − 120, Rig≈ 1. In isothermal flow, the well‐known helical flow structure is observed. In stratified conditions, the vertical variation in relative strength of the outward‐directed baroclinic pressure gradient and the centrifugal acceleration leads to a more complex circulation structure. In the near bed region and immediately above the interface, the centrifugal acceleration is greater, driving flow radially inward, while just below the density interface the baroclinic pressure gradient is greater, leading to outward‐directed flow. This produces a four layer circulation structure with potentially significant implications for sediment erosion and transport. Additionally, this produces a complex dynamic at the density interface where the shear orientation varies through approximately 200° over the mixing layer depth.
Functional characterization of long-chain prenyl diphosphate synthases from tomato
Authors: Jones Matthew O. , Perez-Fons Laura , Robertson Francesca P. , Bramley Peter M. , Fraser Paul D.
Published: November 2012

The electron transfer molecules plastoquinone and ubiquinone are formed by the condensation of aromatic head groups with long-chain prenyl diphosphates. In the present paper we report the cloning and characterization of two genes from tomato (Solanum lycopersicum) responsible for the production of solanesyl and decaprenyl diphosphates. SlSPS (S. lycopersicum solanesyl diphosphate synthase) is targeted to the plastid and both solanesol and plastoquinone are associated with thylakoid membranes. A second gene [SlDPS (S. lycopersicum solanesyl decaprenyl diphosphate synthase)], encodes a long-chain prenyl diphosphate synthase with a different subcellular localization from SlSPS and can utilize geranyl, farnesyl or geranylgeranyl diphosphates in the synthesis of C45 and C50 prenyl diphosphates. When expressed in Escherichia coli, SlSPS and SlDPS extend the prenyl chain length of the endogenous ubiquinone to nine and ten isoprene units respectively. In planta, constitutive overexpression of SlSPS elevated the plastoquinone content of immature tobacco leaves. Virus-induced gene silencing showed that SlSPS is necessary for normal chloroplast structure and function. Plants silenced for SlSPS were photobleached and accumulated phytoene, whereas silencing SlDPS did not affect leaf appearance, but impacted on primary metabolism. The two genes were not able to complement silencing of each other. These findings indicate a requirement for two long-chain prenyl diphosphate synthases in the tomato.
Tailored second-line therapy in asthmatic children with the Arg16 genotype
Authors: Lipworth Brian J. , Basu Kaninika , Donald Helen P. , Tavendale Roger , Macgregor Donald F. , Ogston Simon A. , Palmer Colin N. A. , Mukhopadhyay Somnath
Published: November 2012

The Arg16 β2 receptor genotype confers increased susceptibility to exacerbations in asthmatic children taking regular LABA (long-acting β2 agonists). We therefore evaluated using montelukast as an alternative to salmeterol as tailored second-line asthma controller therapy in children expressing this susceptible genotype. A total of 62 persistent asthmatic children with the homozygous Arg16 genotype were randomized to receive salmeterol (50 μg, b.i.d.) or montelukast (5 or 10 mg, once daily) as an add-on to inhaled fluticasone for 1 year. School absences (the primary outcome) were reduced with montelukast compared with salmeterol {difference in score=−0.40 [95% CI (confidence interval), −0.22 to −0.58]; P=0.005}. Salbutamol use was also reduced with montelukast compared with salmeterol [difference in score=−0.47 (95% CI, −0.16 to −0.79); P<0.0001]. Greater improvements occurred in both symptom and quality of life scores with montelukast against salmeterol, whereas there was no difference in FEV1 (forced expiratory volume in 1 s). In conclusion, montelukast may be suitable as tailored second-line controller therapy instead of salmeterol in asthmatic children expressing the susceptible Arg16 genotype, a move towards a personalized medicine approach to management.
Note: Laser frequency shifting by using two novel triple-pass acousto-optic modulator configurations
Authors: de Carlos-López E. , López J. M. , López S. , Espinosa M. G. , Lizama L. A.
Published: November 2012

We report the design of two novel triple-pass acousto-optic modulator systems. These designs are extensions of the well known acousto-optic modulator (AOM) double-pass configuration, which eliminates the angle dependence of the diffracted beam with respect to the modulation frequency. In a triple-pass system, however, the frequency dependence of the angle does not disappear but the frequency shift is larger, spanning 3 times the AOM central frequency. In some applications, such as optically pumped Cesium-beam frequency standards, the frequencies of the two laser beams remain fixed and a triple-pass optical system can be used to reduce to one the number of lasers used in such atomic clocks. The two triple-pass configurations use either a retro-reflecting mirror, or a right angle prism to pass for third time the laser beam through the AOM, obtaining diffraction efficiencies of about 27% and 44%, respectively.
Origins of thermal boundary conductance of interfaces involving organic semiconductors
Authors: Jin Yansha , Shao Chen , Kieffer John , Pipe Kevin P. , Shtein Max
Published: November 2012

We measure the room temperature thermal conductance of interfaces between an archetypal organic semiconductor copper phthalocyanine (CuPc) and several metals (aluminum, gold, magnesium, and silver) using the 3−ω method. The measured thermal boundary conductance (TBC) scales with bonding strength at the CuPc-metal interface, a correlation that is supported by molecular dynamics (MD) simulation, allowing the extrapolation of the effective interface Young's modulus. The trend in modeled interface modulus is in agreement with that deduced from adhesion tests, e.g., approximately 2 GPa for CuPc-gold and CuPc-silver interfaces, comparable to the van der Waals interaction strength of the materials. Using MD simulations in which the effects on thermal transport can be studied as a function of interfacial bond strength only, we isolate the relative contribution of acoustic mismatch and interface bond strength to TBC. Furthermore, measurements and modeling of organic/organic (e.g., CuPc/C60) interfaces reveal that the TBC of this system is not as sensitive to bonding strength as the CuPc/metal system, due to a larger overlap in the phonon density of states in the low frequency regime, despite the weak bonding between organic layers.
Potassium spin polarization lifetime for a 30-carbon chain siloxane film
Authors: Hibberd Amber M. , Bergman Susanna L. , Zhong Yu Lin , Bernasek Steven L.
Published: November 2012

The siloxane film derived from the 30-carbon chain triacontyltrichlorosilane (TCTS) is studied as an anti-relaxation coating for atomic vapor cells. The longitudinal spin relaxation lifetime of optically pumped potassium atoms in the presence of TCTS is measured and the average number of non-relaxing atom-wall collisions, or bounces, enabled by the coated surface is determined. X-ray photoelectron spectroscopy (XPS) and atomic force microscopy (AFM) of TCTS were performed to investigate changes in chemical states and surface morphology of TCTS arising from K atom deposition on the film surface. TCTS was found to give approximately 530 bounces. Following lifetime measurements, K2p signals were clearly observed in XPS spectra. AFM images display non-preferential K deposition on the TCTS surface, however additional AFM studies with a TCTS surface exposed to Rb atoms show deposition occurs along surface defects. In agreement, Rb is found to preferentially deposit along the step edges of an 18-carbon chain monolayer film derived from 1-Octadecene. Finally, AFM indicates a much smoother surface for a tetracontane coating relative to TCTS. The importance of siloxane surface morphology versus film thickness with respect to coating performance is discussed.
Metallic mesh-based terahertz biosensing of single- and double-stranded DNA
Authors: Hasebe Takayuki , Kawabe Shunsuke , Matsui Hiroaki , Tabata Hitoshi
Published: November 2012

We report on a promising approach for the label-free analysis of DNA molecules with electromagnetic surface waves in the terahertz (THz) region. A metallic mesh with a polyvinylidene difluoride membrane is employed for THz transmission analysis. The metallic mesh with opening holes provides a sharp dip structure in a THz transmission spectrum, which is sensitive to a small change of the refractive index of a sample on the metallic mesh surface. The optical properties of a small amount of DNA molecules cannot be investigated by a free-space THz measurement because of the low absorption coefficients of such samples. However, metallic mesh-based THz measurement revealed the difference in optical properties between single- and double-stranded DNA molecules on the basis of refractive index, as estimated from a dip frequency shift of the metallic mesh. Therefore, our metallic-based THz technique provides a dramatically enhanced sensitivity, and demonstrates the potential of our approach of the analysis of biologically relevant DNA samples.