bluuebunny/crossref_metadata_2025 huggingface dataset:
The fate of the oculomotor system in clinical bilateral anophthalmia
Authors: BRIDGE HOLLY , RAGGE NICOLA , JENKINSON NED , COWEY ALAN , WATKINS KATE E.
Published: May 2012

The interdependence of the development of the eye and oculomotor system during embryogenesis is currently unclear. The occurrence of clinical anophthalmia, where the globe fails to develop, permits us to study the effects this has on the development of the complex neuromuscular system controlling eye movements. In this study, we use very high-resolution T2-weighted imaging in five anophthalmic subjects to visualize the extraocular muscles and the cranial nerves that innervate them. The subjects differed in the presence or absence of the optic nerve, the abducens nerve, and the extraocular muscles, reflecting differences in the underlying disruption to the eye’s morphogenetic pathway. The oculomotor nerve was present in all anophthalmic subjects and only slightly reduced in size compared to measurements in sighted controls. As might be expected, the presence of rudimentary eye-like structures in the socket appeared to correlate with development and persistence of the extraocular muscles in some cases. Our study supports in part the concept of an initial independence of muscle development, with its maintenance subject to the presence of these eye-like structures.
Increased Marijuana Use and Gender Predict Poorer Cognitive Functioning in Adolescents and Emerging Adults
Authors: Lisdahl Krista M. , Price Jenessa S.
Published: May 2012

This study sought to characterize neuropsychological functioning in MJ-using adolescents and emerging adults (ages 18–26) and to investigate whether gender moderated these effects. Data were collected from 59 teens and emerging adults including MJ users (n = 23, 56% female) and controls (n = 35, 50% female) aged 18–26 (M = 21 years). Exclusionary criteria included independent Axis I disorders (besides SUD), and medical and neurologic disorders. After controlling for reading ability, gender, subclinical depressive symptoms, body mass index, and alcohol and other drug use, increased MJ use was associated with slower psychomotor speed/sequencing ability (p < .01), less efficient sustained attention (p < .05), and increased cognitive inhibition errors (p < .03). Gender significantly moderated the effects of MJ on psychomotor speed/sequencing ability (p < .003) in that males had a more robust negative relationship. The current study demonstrated that MJ exposure was associated with poorer psychomotor speed, sustained attention and cognitive inhibition in a dose-dependent manner in young adults, findings that are consistent with other samples of adolescent MJ users. Male MJ users demonstrated greater cognitive slowing than females. Future studies need to examine the neural substrates underlying with these cognitive deficits and whether cognitive rehabilitation or exercise interventions may serve as a viable treatments of cognitive deficits in emerging adult MJ users. (JINS, 2012, 18, 1–11)
Cognitive and Prepulse Inhibition Deficits in Psychometrically High Schizotypal Subjects in the General Population: Relevance to Schizophrenia Research
Authors: Giakoumaki Stella G.
Published: May 2012

Schizophrenia and schizotypal personality disorder share common clinical profiles, neurobiological and genetic substrates along with Prepulse Inhibition and cognitive deficits; among those, executive, attention, and memory dysfunctions are more consistent. Schizotypy is considered to be a non-specific “psychosis-proneness,” and understanding the relationship between schizotypal traits and cognitive function in the general population is a promising approach for endophenotypic research in schizophrenia spectrum disorders. In this review, findings for executive function, attention, memory, and Prepulse Inhibition impairments in psychometrically defined schizotypal subjects have been summarized and compared to schizophrenia patients and their unaffected first-degree relatives. Cognitive flexibility, sustained attention, working memory, and Prepulse Inhibition impairments were consistently reported in high schizotypal subjects in accordance to schizophrenia patients. Genetic studies assessing the effects of various candidate gene polymorphisms in schizotypal traits and cognitive function are promising, further supporting a polygenic mode of inheritance. The implications of the findings, methodological issues, and suggestions for future research are discussed. (JINS, 2012,18, 1–14)
Variation in supermarket exposure to energy-dense snack foods by socio-economic position
Authors: Cameron Adrian J , Thornton Lukar E , McNaughton Sarah A , Crawford David
Published: May 2012

Objective

The present study aimed to examine the availability of energy-dense, nutrient-poor snack foods (and fruits and vegetables) in supermarkets located in socio-economically advantaged and disadvantaged neighbourhoods.

Design

Cross-sectional supermarket audit.

Setting

Melbourne, Australia. Measures included product shelf space and number of varieties for soft drinks, crisps, chocolate, confectionery and fruits and vegetables, as well as store size.

Subjects

Thirty-five supermarkets (response 83 %) from neighbourhoods in the lowest and highest quintile of socio-economic disadvantage.

Results

Shelf space allocated to soft drinks (23·6 mv. 17·7 m,P= 0·006), crisps (16·5 mv. 13·0 m,P= 0·016), chocolate (12·2 mv. 10·1 m,P= 0·022) and confectionery (6·7 mv. 5·1 m,P= 0·003) was greater in stores from socio-economically disadvantaged neighbourhoods. After adjustment for store size (stores in disadvantaged areas being larger), shelf space for confectionery (6·3 mv. 5·6 m,P= 0·024) and combined shelf space for all energy-dense foods and drinks (55·0 mv. 48·9 m,P= 0·017) remained greater in stores from socio-economically disadvantaged neighbourhoods. The ratio of shelf space allocated to fruits and vegetables to that for energy-dense snack foods also varied by socio-economic disadvantage after adjustment for store size (most disadvantagedv. least disadvantaged: 1·7v. 2·1,P= 0·025). Varieties of fruits and vegetables and chocolate bars were more numerous in less disadvantaged areas (P< 0·05).

Conclusions

Exposure to energy-dense snack foods and soft drinks in supermarkets was greater in socio-economically disadvantaged neighbourhoods. This may impact purchasing, consumption and cultural norms related to eating behaviours and may therefore work against elimination of the known socio-economic gradient in obesity levels. Reform of supermarket stocking practices may represent an effective means of obesity prevention.
Girls from Wales in the Secure Estate: Sent to Coventry?
Authors: Hughes Caroline , Dubberley Sarah , Buchanan Julian
Published: May 2012

Drawing upon recent literature and a small-scale survey that explored the perceptions and experiences of front line workers and incarcerated girls1 from North Wales, this article examines the needs and experiences of girls who commit crime in Wales but are subsequently ‘exported’ to England to serve their sentence. While not literally sent to Coventry, these indigenous girls from Wales are forced to reside in the secure estate in England and metaphorically ‘sent to Coventry’. This article considers important emerging issues including: human rights, discrimination, identity, linguistic need, family contact and resettlement.
End-of-life spiritual care at a VA medical center: Chaplains' perspectives
Authors: Chang Bei-Hung , Stein Nathan R. , Trevino Kelly , Stewart Max , Hendricks Ann , Skarf Lara M.
Published: May 2012

Objective:

Spiritual care is an essential component of quality palliative care. Recognizing the importance, the Department of Veterans Affairs (VA) mandates the inclusion of chaplains in a palliative care consult team (PCCT). The purpose of this study is to explain the process and content of spiritual care provided in a VA Medical Center from chaplains' perspectives.

Method:

Five Christian chaplains who provide care to patients at end of life were interviewed. Each interview was recorded and transcribed. Analysis based on the grounded theory was used to identify themes from each interview question.

Results:

The PCCT in this study appeared to have a strong referral and communication system in which every palliative care patient was seen by a chaplain and the care plan was discussed with an interdisciplinary team. Chaplains reported providing a range of services, which addressed religious, spiritual, emotional, family, and illness concerns. Chaplains were aware of the unique spiritual needs of veterans, including working through guilt for killing in war and requiring forgiveness. Chaplains' ideas for improvement of spiritual care services included increasing time to provide care, providing bereavement care and support to families, and adding chaplains with different religious backgrounds. Chaplains reported how their own spirituality influenced the care they provided.

Significance of results:

Spiritual care in the VA can include a range of services and should consider the unique needs of the veteran population. Future studies can build upon our findings from chaplains to learn about the perspectives of patients, family, and other healthcare providers of spiritual care. This information would allow identification of strengths of current spiritual care practices and areas for care improvement, and ultimately could improve the well-being of patients at the end of life.
Cultural and religious considerations in pediatric palliative care
Authors: Wiener Lori , McConnell Denice Grady , Latella Lauren , Ludi Erica
Published: May 2012

Objective:

A growing multicultural society presents healthcare providers with a difficult task of providing appropriate care for individuals who have different life experiences, beliefs, value systems, religions, languages, and notions of healthcare. This is especially vital when end-of-life care is needed during childhood. There is a dearth of literature addressing cultural considerations in the pediatric palliative care field. As members of a specific culture often do not ascribe to the same religious traditions, the purpose of this article was to explore and review how culture and religion informs and shapes pediatric palliative care.

Method:

Comprehensive literature searches were completed through an online search of nine databases for articles published between 1980 and 2011: PsychINFO, MEDLINE®,Journal of Citation Reports-Science Edition, Embase, Scopus, CINAHL®, Social Sciences Citation Index (SSCI), EBSCO, and Ovid. Key terms included:culture, transcultural,spiritual, international,ethnic,customsorreligionANDend-of-life,palliative care,death,dying,cancer, orhospice, andchildren,pediatrics, orpediatric oncology. Reference lists in the retrieved articles were examined for additional studies that fit the inclusion criteria, and relevant articles were included for review. In addition, web-based searches of specific journals were conducted. These included, but were not limited to:Qualitative Health Research,Psycho-Oncology,Journal of Psychosocial Oncology,Journal of Pediatric Psychology,Journal of Pediatric Health Care,Journal of Pediatric Oncology Nursing,Omega,Social Work in Health Care, andJournal of Palliative Medicine.

Results:

Thirty-seven articles met eligibility criteria. From these, seven distinct themes emerged that have implications for pediatric palliative care. These include the role of culture in decision-making, faith and the involvement of clergy, communication (spoken and unspoken language), communicating to children about death (truth telling), the meaning of pain and suffering, the meaning of death and dying, and location of end-of-life care.

Significance of results:

The review of the literature provides insight into the influence of religion and how culture informs lifestyle and shapes the experiences of illness, pain, and end-of-life care. Recommendations for providing culturally sensitive end-of-life care are offered through the framework outlined in the Initiative for Pediatric Palliative Care Quality Improvement Project of 2002. Cultural traditions are dynamic, never static, and cannot be generalized to all families. Guidelines to aid in approaches to palliative care are provided, and providers are encouraged to define these important differences for each family under their care.
Symptom experience and regaining normality in the first year following a diagnosis of head and neck cancer: A qualitative longitudinal study
Authors: Molassiotis Alex , Rogers Margaret
Published: May 2012

Introduction:

Symptom experiences and their interference with life are not well-researched in head and neck cancer patients. The aim of the study was to explore and understand the experience of receiving treatment for head and neck cancer with particular focus on symptom experiences over a one year period from diagnosis.

Methods:

A qualitative study design was used with a heterogeneous sample of 16 patients with head and neck cancer. Interviews, conducted at four time points over 12 months, provided a total of 50 interview datasets.

Results:

Key themes derived include nutritional concerns, tiredness, and experiences related to the radiotherapy mask and regaining normality. These data highlight issues of importance in the first year of living with head and neck cancer: impact of nutritional changes on the lives of patients, including weight loss, dysphagia, xerostomia and taste changes; debilitation from ongoing fatigue; unpreparedness for and distress from the radiotherapy mask; and attempts to maintain a normal life amidst the interference of symptoms.

Conclusion:

Multitude of symptoms impact the patients' life, particularly nutritional symptoms and fatigue, and interfere with the patients' survivorship and quality of life. The changing nature of symptoms over the first year from diagnosis in head and neck cancer patients and the identified issues in the attempt to normalize their lives need to be incorporated more fully into the supportive care of head and neck cancer patients in order to improve their experience and enhance their survivorship.
Functions of microglia in the central nervous system – beyond the immune response
Authors: Wake Hiroaki , Moorhouse Andrew J. , Nabekura Junichi
Published: May 2012

Microglia cells are the immune cells of the central nervous system and consequently play important roles in brain infections and inflammation. Recent in vivo imaging studies have revealed that in the resting healthy brain, microglia are highly dynamic, moving constantly to actively survey the brain parenchyma. These active microglia can rapidly respond to pathological insults, becoming activated to induce a range of effects that may contribute to both pathogenesis, or to confer neuronal protection. However, interactions between microglia and neurons are being recognized as important in shaping neural circuit activity under more normal, physiological conditions. During development and neurogenesis, microglia interactions with neurons help to shape the final patterns of neural circuits important for behavior and with implications for diseases. In the mature brain, microglia can respond to changes in sensory activity and can influence neuronal activity acutely and over the long term. Microglia seem to be particularly involved in monitoring the integrity of synaptic function. In this review, we discuss some of these new insights into the involvement of microglia in neural circuits.
The role of political trust in conditioning perceptions of corruption
Authors: Wroe Andrew , Allen Nicholas , Birch Sarah
Published: May 2012

Political trust and corruption have both elicited considerable academic and popular commentary in recent years. Much attention has been focused on the extent to which corruption has contributed to citizens’ increasing distrust of their politicians. But little attention has been paid to the possibility that distrust may condition responses to alleged corruption, and no work has hitherto demonstrated the veracity of this relationship in a mature democracy. Drawing on data from the United Kingdom, this paper finds that less trusting individuals are consistently more censorious of politicians’ misbehaviour and more likely to perceive the presence of corruption than are their more trusting peers. The paper further demonstrates that people who are less trusting become relatively more critical (compared with the more trusting) as the generally perceived corruptness of a certain scenariodeclines. It also demonstrates how trust increases in importance as a predictor of ethical judgements when behaviour is generally reckoned to be less corrupt. Further analysis suggests that this effect is partly connected to uncertainty. Less obviously corrupt acts are associated with higher levels of uncertainty, which appears to open up a space for trust to play an even more significant role in shaping individual's judgements of politicians’ behaviour.
Property Rights and Participation in REDD+: The Case of Mozambique
Authors: Ludwig Grit
Published: May 2012

Reducing emissions from deforestation and forest degradation with the help of the emerging REDD+ mechanism provides an opportunity to combine climate protection with biodiversity conservation and poverty alleviation. However, one of the crucial questions is how the rights of indigenous peoples and local communities will be protected in REDD+ implementation. This article depicts the challenges involved in protecting the rights of local communities in the case of Mozambique. The study finds that constraints regarding property and participation rights arise, in particular, from incomplete procedures of delimitation and titling, corruption, lack of rights awareness, lack of democratic structures within the community or poor infrastructure. Because many states with a REDD+ potential are not able to guarantee sufficient rights protection, the REDD+ mechanism itself needs to be endowed with strong safeguards for the rights of indigenous peoples and local communities.
Characteristics and generation of secondary jets and secondary gigantic jets
Authors: Lee Li‐Jou , Huang Sung‐Ming , Chou Jung‐Kung , Kuo Cheng‐Ling , Chen Alfred B. , Su Han‐Tzong , Hsu Rue‐Rou , Frey Harald U. , Takahashi Yukihiro , Lee Lou‐Chuang
Published: May 2012

Secondary transient luminous events (TLEs) recorded by the ISUAL‐FORMOSAT2 mission can either be secondary jets or secondary gigantic jets (GJs), depending on their terminal altitudes. The secondary jets emerge from the cloud top beneath the preceding sprites and extend upward to the base of the sprites at ∼50 km. The secondary jets likely are negative electric discharges with vertically straight luminous columns, morphologically resembling the trailing jet of the type‐I GJs. The number of luminous columns in a secondary jet seems to be affected by the size of the effective capacitor plate formed near the base of the preceding sprites and the charge distribution left behind by the sprite‐inducing positive cloud‐to‐ground discharges. The secondary GJs originate from the cloud top under the shielding area of the preceding sprites, and develop upward to reach the lower ionosphere at ∼90 km. The observed morphology of the secondary GJs can either be the curvy shifted secondary GJs extending outside the region occupied by the preceding sprites or the straight pop‐through secondary GJs developing through the center of the preceding circular sprites. A key factor in determining the terminal height of the secondary TLEs appears to be the local ionosphere boundary height that established by the preceding sprites. The abundance and the distribution of the negative charge in the thundercloud following the sprite‐inducing positive cloud‐to‐ground discharges may play important role in the generation of the secondary TLEs.
Bayesian analysis of the modified Omori law
Authors: Holschneider M. , Narteau C. , Shebalin P. , Peng Z. , Schorlemmer D.
Published: May 2012

In order to examine variations in aftershock decay rate, we propose a Bayesian framework to estimate the {K, c, p}‐values of the modified Omori law (MOL), λ(t) = K(c + t)−p. The Bayesian setting allows not only to produce a point estimator of these three parameters but also to assess their uncertainties and posterior dependencies with respect to the observed aftershock sequences. Using a new parametrization of the MOL, we identify the trade‐off between the c and p‐value estimates and discuss its dependence on the number of aftershocks. Then, we analyze the influence of the catalog completeness interval [tstart, tstop] on the various estimates. To test this Bayesian approach on natural aftershock sequences, we use two independent and non‐overlapping aftershock catalogs of the same earthquakes in Japan. Taking into account the posterior uncertainties, we show that both the handpicked (short times) and the instrumental (long times) catalogs predict the same ranges of parameter values. We therefore conclude that the same MOL may be valid over short and long times.
Delineation of recharge rate from a hybrid water table fluctuation method
Authors: Park Eungyu
Published: May 2012

The concept of the hybrid water table fluctuation (WTF) method for recharge rate estimation was revisited. To estimate the recharge rate, a physically based WTF equation was established. The concept of transient fillable porosity was proposed and computed with unsaturated hydraulics models. The developed model is tested by applying to the water table fluctuation data from Hongcheon, Korea. In the applications, the recharge and fillable porosity estimates were found to be most sensitive to nonlinearity in the unsaturated water content profile and permeability. Also, the water table level drift, which does not originate from precipitation, serves as a major source of estimation error.
Delayed deglaciation or extreme Arctic conditions 21‐16 cal. kyr at southeastern Laurentide Ice Sheet margin?
Authors: Peteet D. M. , Beh M. , Orr C. , Kurdyla D. , Nichols J. , Guilderson T.
Published: May 2012

The conventionally accepted ages of the Last Glacial Maximum (LGM) retreat of the southeastern Laurentide Ice Sheet (LIS) are 26–21 cal. kyr (derived from bulk‐sediment radiocarbon ages) and 28–23 cal. kyr (varve estimates). Utilizing accelerator mass spectrometry (AMS)14C dating of earliest macrofossils in 13 lake/bog inorganic clays, we find that vegetation first appeared on the landscape at 16–15 cal. kyr, suggesting ice had not retreated until that time. The gap between previous age estimates and ours is significant and has large implications for our understanding of ocean‐atmosphere linkages. Older ages imply extreme Arctic conditions for 9–5 cal kyr; a landscape with no ice, yet no deposition in lakes. Our new AMS chronology of LIS retreat is consistent with marine evidence of deglaciation from the N. Atlantic, showing significant freshwater input and sea level rise only after 19 cal kyr with a cold meltwater lid, perhaps delaying ice melt.
Influence of sediment deposition on deep lithospheric tectonics
Authors: Gray R. , Pysklywec R. N.
Published: May 2012

Previous geodynamic models of continental collision show that the behavior of the lithosphere can be strongly influenced by the presence of surface erosion. That said, absent from these investigations are the effects of sediment deposition. We quantitatively investigate this process using thermal‐mechanical numerical experiments of the coupled processes of tectonic deformation and crustal mass flux. The models demonstrate that the inclusion of the effects of sediment deposition can change the style of deformation of the crust and consequently, the evolution of the underlying deforming mantle lithosphere. In the absence of sediment deposition, the early stages of collision are accommodated by subduction of lower crust and mantle lithosphere along a discrete shear zone beneath the overriding plate. Following this initial stage of subduction, the subducting lower crust and mantle lithosphere retreat from the collision zone, permitting the sub‐lithospheric mantle to upwell and come into contact with the thickened upper crust. When sediment deposition is imposed subduction‐like consumption of the subducting plate remains stable. The presence of sediment deposition introduces a negative Vy‐component in the overriding plate in the area adjacent to the collisional zone. The negative Vy‐component leads to a greater degree of coupling between the colliding continental plates and decoupling of the overriding upper crust and lower crust/mantle lithosphere. The results demonstrate the first quantitative insights into the feedback between surface deposition and tectonics.
Geodetic imaging of coseismic slip and postseismic afterslip: Sparsity promoting methods applied to the great Tohoku earthquake
Authors: Evans Eileen L. , Meade Brendan J.
Published: May 2012

Geodetic observations of surface displacements during and following earthquakes such as the March 11, 2011 great Tohoku earthquake can be used to constrain the spatial extent of coseismic slip and postseismic afterslip, and characterize the spectrum of earthquake cycle behaviors. Slip models are often regularized by assuming that slip on the fault varies smoothly in space, which may result in the artificial smearing of fault slip beyond physical boundaries. Alternatively, it may be desirable to estimate a slip distribution that is spatially compact and varies sharply. Here we show that sparsity promoting state vector regularization methods can be used to recover slip distributions with sharp boundaries, representing an alternative end‐member result to very smooth slip distributions. Using onshore GPS observations at 298 stations during and in the ∼2 weeks following the Tohoku earthquake, we estimate a band of coseismic slip between 30 and 50 km depth extending 500 km along strike with a maximum slip of 64 m, corresponding to a minimum magnitude estimate of MW = 8.8. Our estimate of afterslip is located almost exclusively down‐dip of the coseismic rupture, with a transition between 40 and 50 km depth and an equivalent moment magnitude MW = 8.2. This depth may be interpreted as coincident with the transition from velocity strengthening to velocity weakening frictional behavior, consistent with the upper limit of cold subduction estimates of the thermal structure of the Japan trench.
Comparison of ray‐ and adjoint‐based sensitivity kernels for body‐wave seismic tomography
Authors: Mercerat E. D. , Nolet G.
Published: May 2012

We compare finite‐frequency sensitivity kernels computed from ray‐theoretical wavefields (“banana‐doughnut” kernels) and from full waveform computations (often called “adjoint” kernels) in order to evaluate resolution, accuracy and computational cost. We focus here on body‐wave seismic tomography at regional and local scales. Our results show that: (1) for homogeneous reference media, ray‐based and adjoint kernels agree except for the expected differences in the regions close to the source and the receiver, where near‐field contributions are neglected in the ray‐based kernels; (2) for a smooth 3D background velocity model, the differences in predicted delay times for the two methods are generally well below 10 % of the delay for P waves, though as much as 20 % for S‐waves, suggesting that extra care should be taken when performing S‐wave tomography with ray‐based “banana doughnut” kernels.
Statistical analysis of global variations of atmospheric relative humidity as observed by AIRS
Authors: Du J. , Cooper F. , Fueglistaler S.
Published: May 2012

Atmospheric water vapor plays a key role in the climate. Numerical model calculations suggest that global mean relative humidity (RH) stays approximately constant in global warming scenarios. Here, we analyze the September 2002 to April 2011 daily mean free tropospheric relative humidity (RH) data from the Atmospheric Infrared Sounder (AIRS), version 5 level 3 data at a spatial resolution of 1°/1° longitude/latitude. We perform a multiple linear regression analysis with annual harmonics, trend and an El‐Niño–Southern Oscillation (ENSO) index. For the mean annual cycle, we find strong compensation of local variability upon global averaging, leaving an amplitude for the global mean of about 4% RH (peak to peak) at 300 hPa, with the minimum in February. The amplitude decreases to about 2.5%RH at 500 hPa (with minimum shifted to boreal summer/early fall) and less than 2%RH further below. For ENSO, the local changes compensate strongly upon global averaging. Computational limitations restrict detailed analysis of the residual to the zonal mean residual, which we interpret with a stochastic model that takes the latitudinal covariance into account. We find that the relation between zonal mean residual RH variations (understood as the consequence of ‘weather’ and subseasonal variability) and their global mean is equivalent to that of about 9 independent random time series with appropriate variances. The residual contributes more to the variance of the global mean than the harmonics and ENSO on all free tropospheric levels except 400 hPa. Our results apply to the AIRS version 5 data as reported, and possible problems in that data are discussed.
UV degradation of accreted organics on Mars: IDP longevity, surface reservoir of organics, and relevance to the detection of methane in the atmosphere
Authors: Moores John E. , Schuerger Andrew C.
Published: May 2012

Reanalysis of the Viking Lander results on Mars has suggested a surface reservoir of organic carbon at the ppm level. The size of this putative reservoir could be explained if the source of carbon on Mars is meteoritic in origin and is destroyed primarily by UV irradiation, yielding methane. By combining a numerical UV model for the surface of Mars with published laboratory measurements of organic UV photolysis, the times required to completely convert the carbon within individual particles to methane may be calculated. For interplanetary dust particles (IDPs) initially containing 10 wt% carbon, lifetimes of organics range from 3.9 years for a 0.2 μm diameter particle at equatorial latitudes to 4900 years for a 200 μm diameter particle at polar latitudes, and implies a median time for IDP organics by UV photolysis of 320 years at equatorial latitudes and 1500 years at polar latitudes. Assuming no redistribution of organics over the surface, the IDP organic reservoir at the surface would range from 1.1 × 10−6 kg m−2 at equatorial latitudes to 6.6 × 10−6 kg m−2 at polar latitudes. If accreted carbon is evenly mixed with the soil, up to 3.4 ppm of organic carbon at the VL1 landing site can be explained from a meteoritic origin and up to 4.9 ppm at the VL2 landing site. Derived from the IDP organic reservoir, small fluctuations in methane would exist due to variations in UV irradiation with latitude and LS. Production of methane is expected to range up to 0.35 pptv sol−1.
Chromosomal instability and aneuploidy in cancer: from yeast to man
Authors: Pfau Sarah J , Amon Angelika
Published: May 2012

Aneuploidy is frequently associated with disease and developmental abnormalities. It is also a key characteristic of cancer. Several model systems have been developed to study the role of chromosomal instability and aneuploidy in tumorigenesis. The results are surprisingly complex, with the conditions sometimes promoting and sometimes inhibiting tumour formation. Here, we review the effects of aneuploidy and chromosomal instability in cells and model systems of cancer, propose a model that could explain these complex findings and discuss how the aneuploid condition could be exploited in cancer therapy.
Solution structure of the core SMN–Gemin2 complex
Authors: Sarachan Kathryn L. , Valentine Kathleen G. , Gupta Kushol , Moorman Veronica R. , Gledhill John M. , Bernens Matthew , Tommos Cecilia , Wand A. Joshua , Van Duyne Gregory D.
Published: May 2012

In humans, assembly of spliceosomal snRNPs (small nuclear ribonucleoproteins) begins in the cytoplasm where the multi-protein SMN (survival of motor neuron) complex mediates the formation of a seven-membered ring of Sm proteins on to a conserved site of the snRNA (small nuclear RNA). The SMN complex contains the SMN protein Gemin2 and several additional Gemins that participate in snRNP biosynthesis. SMN was first identified as the product of a gene found to be deleted or mutated in patients with the neurodegenerative disease SMA (spinal muscular atrophy), the leading genetic cause of infant mortality. In the present study, we report the solution structure of Gemin2 bound to the Gemin2-binding domain of SMN determined by NMR spectroscopy. This complex reveals the structure of Gemin2, how Gemin2 binds to SMN and the roles of conserved SMN residues near the binding interface. Surprisingly, several conserved SMN residues, including the sites of two SMA patient mutations, are not required for binding to Gemin2. Instead, they form a conserved SMN/Gemin2 surface that may be functionally important for snRNP assembly. The SMN–Gemin2 structure explains how Gemin2 is stabilized by SMN and establishes a framework for structure–function studies to investigate snRNP biogenesis as well as biological processes involving Gemin2 that do not involve snRNP assembly.
Cell‐selective gene silencing in prostate cancer LNCap cells using prostate‐specific membrane antigen promoter and enhancer in vitro and in vivo
Authors: Liu Ranlu , Sun Jiantao , Zhang Zhihong , Xu Yong
Published: May 2012

RNAi (RNA interference) has been widely used to silence specific genes. However, RNAi may also cause off‐target silencing and elicit non‐specific side effects. To achieve cell‐specific gene silencing, a cell‐selective promoter has to be used to drive RNAi expression. Furthermore, different terminators of cell‐selective promoters may cause different silencing efficacies. In order to explore the best promoter and terminator combination and prove the cell‐selective gene silencing effect of PSMAe/p (prostate‐specific membrane antigen enhancer/promoter), we first constructed three plasmids by using PSMAe/p and three different terminators [poly(A), minipoly(A) and poly(U)] to explore the cell‐selective driving ability of PSMAe/p by targeting EGFP (enhanced green fluorescent protein) in LNCaP, PC‐3, EJ and HEK‐293 (human embryonic kidney) cells. Then we chose NS (nucleostemin), an important endogenous gene of prostate cancer, and constructed the NS‐targeting shRNA (small‐hairpin RNA) expression plasmid by using PSMAe/p—poly(A) combination. Cell proliferation, cell cycle and early apoptosis in vitro and xenograft tumour growth in BALB/c nude mice in vivo were detected after NS knockdown. Results showed that PSMAe/p can drive EGFP silencing in LNCaP, not in PC‐3, EJ and HEK‐293 cells and PSMAe/p—poly(A) combination achieved the best silencing efficacy. Then PSMAe/p‐shNS‐poly(A) drives NS knockdown in LNCaP cells, not in PC‐3, EJ and HEK‐293 cells. Furthermore, RNAi‐mediated NS knockdown not only reduces cell proliferation rate, reduces the percentage of S‐stage cells and increases the percentage of G1‐stage cells and increases the early apoptosis ratio in LNCaP cells in vitro, but also inhibited the LNCaP xenograft tumour growth in BALB/c nude mice in vivo by intratumoural injection. In conclusion, we have demonstrated that PSMAe/p—poly(A) combination is a promising delivery system for targeted RNAi gene therapy of prostate cancer. We showed one effective antitumour strategy by targeting NS protein, an important target in prostate cancer, with PSMAe/p‐shNS‐poly(A). These results serve as an important step for developing novel strategies to treat prostate cancer.
Sudden Hearing Loss Following a Traumatic Head Injury: A Case Study
Authors: Schroy Catherine , Ortmann Amanda , Mauzé Elizabeth
Published: May 2012

This is a case study of a 40-year-old male with a sudden profound sensorineural hearing loss experienced secondary to a skull fracture incurred during a violent assault. Following the acute phase of his medical care, the patient received long-term multidisciplinary rehabilitative care in two states that included audiologic, psychologic, and vocational services. This case highlights the need to make resources available to the patient, but stresses the importance of a patient-centered approach. Service providers often think they know what is best for their patients and are frustrated, if not disappointed, when patients do not follow advice. In this case, it became apparent that the patient needed to decide when he was ready to address all of the issues related to his hearing loss and subsequent communication, psychosocial, and vocational difficulties.
Utility of the Baddeley and Hitch Model of Short-Term Working Memory To Investigate Spoken Language Understanding: A Tutorial.
Authors: Bielski Lynn M. , Lansing Charissa R.
Published: May 2012

Spoken speech understanding can be challenging, particularly in the presence of competing information such as background noise. Researchers have shown that dynamic observable phonetic facial cues improve speech understanding in both quiet and noise. Additionally, cognitive functions such as short-term working memory influence spoken language understanding. Currently, we do not know the utility of visual cues for the improvement of spoken language understanding. Although there are many theoretical models of short-term memory, the Baddeley and Hitch (1974) multicomponent model of short-term working memory is well-suited as a cognitive framework through which the utility of visual cues in spoken language understanding could be investigated. In this tutorial, we will describe the components of the Baddeley and Hitch model, illustrate their contributions to spoken language understanding, and provide possible applications for the model.
Perceptions About Occupational Experiences by People Who Stutter
Authors: Palasik Scott , Gabel Rodney , Hughes Charles , Rusnak Emily
Published: May 2012

We explored the perceptions about work experiences and discrimination that people who stutter (PWS) report. A total of 184 PWS responded to a paper and pencil or an online version of a questionnaire that included 13 Likert-type scale and demographics questions. Of the respondents, 68 completed a pencil and paper version of the questionnaire and 116 completed an online version. Participants reported that their stuttering affected some aspects of occupational experiences and that their employers had made negative judgments during job interviews and promotional opportunities due to stuttering. Conversely, participants reported that stuttering did not affect whether they were asked to perform supervisory activities, that their coworkers appeared to accept their stuttering, and that stuttering did not affect their choice of careers. Stuttering severity, gender, treatment experiences, type of employment, and differences in salary did not affect participants’ reports related to occupational experiences. Finally, there were no differences between the responses provided by participants responding to the paper and pencil or electronic versions of the survey. In this paper, we discuss relationships between these findings and past research studies exploring occupational experiences of people who stutter.
Aging and Autism
Authors: Smith Pamela A.
Published: May 2012

In this article, I will review the available recent literature about the aging population with autism, a patient group that researchers know little about and a group that is experiencing a growing need for support from communication disorders professionals. Speech-language pathologists working with geriatric patients should become familiar with this issue, as the numbers of older patients with autism spectrum disorders is likely to increase. Our profession and our health care system must prepare to meet the challenge these patients and residents will present as they age.
Transparent conductive electrodes of mixed TiO2−x–indium tin oxide for organic photovoltaics
Authors: Lee Kyu-Sung , Lim Jong-Wook , Kim Han-Ki , Alford T. L. , Jabbour Ghassan E.
Published: May 2012

A transparent conductive electrode of mixed titanium dioxide (TiO2−x)–indium tin oxide (ITO) with an overall reduction in the use of indium metal is demonstrated. When used in organic photovoltaic devices based on bulk heterojunction photoactive layer of poly (3-hexylthiophene) and [6,6]-phenyl C61 butyric acid methyl ester, a power conversion efficiency of 3.67% was obtained, a value comparable to devices having sputtered ITO electrode. Surface roughness and optical efficiency are improved when using the mixed TiO2−x–ITO electrode. The consumption of less indium allows for lower fabrication cost of such mixed thin film electrode.
Many-body calculations of low-energy eigenstates in magnetic and periodic systems with self-healing diffusion Monte Carlo: Steps beyond the fixed phase
Authors: Reboredo Fernando Agustín
Published: May 2012

The self-healing diffusion Monte Carlo algorithm (SHDMC) [F. A. Reboredo, R. Q. Hood, and P. R. C. Kent, Phys. Rev. B 79, 195117 (2009);10.1103/PhysRevB.79.195117 F. A. Reboredo, Phys. Rev. B 80, 125110 (2009)10.1103/PhysRevB.80.125110] is extended to study the ground and excited states of magnetic and periodic systems. The method converges to exact eigenstates as the statistical data collected increase if the wave function is sufficiently flexible. It is shown that the dimensionality of the nodal surface is dependent on whether phase is a scalar function or not. A recursive optimization algorithm is derived from the time evolution of the mixed probability density, which is given by an ensemble of electronic configurations (walkers) with complex weight. This complex weight allows the phase of the fixed-node wave function to move away from the trial wave function phase. This novel approach is both a generalization of SHDMC and the fixed-phase approximation [G. Ortiz, D. M. Ceperley, and R. M. Martin, Phys Rev. Lett. 71, 2777 (1993)10.1103/PhysRevLett.71.2777]. When used recursively it simultaneously improves the node and the phase. The algorithm is demonstrated to converge to nearly exact solutions of model systems with periodic boundary conditions or applied magnetic fields. The computational cost is proportional to the number of independent degrees of freedom of the phase. The method is applied to obtain low-energy excitations of Hamiltonians with magnetic field. Periodic boundary conditions are also considered optimizing wave functions with twisted boundary conditions which are included in a many-body Bloch phase. The potential applications of this new method to study periodic, magnetic, and complex Hamiltonians are discussed.
Pure electron plasmas confined for 90 ms in a stellarator without electron sources or internal objects
Authors: Brenner P. W. , Sunn Pedersen T.
Published: May 2012

We report on the creation and up to 90 ms sustainment of pure electron plasmas confined in a stellarator without internal objects. Injection of positrons into such plasmas is expected to lead to the creation of the first electron-positron plasma experiments. These newly created plasmas will also allow a study of pure electron plasmas without the perturbing presence of internal objects. The plasmas were created by thermionic emission of electrons from a heated, biased filament that was retracted in 20 ms. The confinement of these transient plasmas is different from that of steady state plasmas with internal objects and emissive filaments, and is generally shorter, limited by ion buildup. The decay time is increased by lowering the neutral pressure, lowering the electron plasma temperature, or operating with neutrals with high ionization energies (helium). These findings are all consistent with ion accumulation being the cause for the shorter than expected confinement times. The magnetic field strength also moderately increases the decay times. The deleterious effect of ions is not expected to imply a similar deleterious effect when introducing positrons, but it implies that ion accumulation must be avoided also in an electron-positron experiment.
Thin smart multilayer microwave absorber based on hybrid structure of polymer and carbon nanotubes
Authors: Danlée Y. , Huynen I. , Bailly C.
Published: May 2012

We present a thin and flexible multilayer solution for effective absorption of electromagnetic waves from 8 to 40 GHz and probably higher. Submillimetric conductive and dielectric layers based on polymer and carbon nanotubes are successively stacked. A smart gradient-periodic arrangement results in a very high absorption index despite overall millimetric thickness of the system.
Self-propulsion in viscoelastic fluids: Pushers vs. pullers
Authors: Zhu Lailai , Lauga Eric , Brandt Luca
Published: May 2012

We use numerical simulations to address locomotion at zero Reynolds number in viscoelastic (Giesekus) fluids. The swimmers are assumed to be spherical, to self-propel using tangential surface deformation, and the computations are implemented using a finite element method. The emphasis of the study is on the change of the swimming kinematics, energetics, and flow disturbance from Newtonian to viscoelastic, and on the distinction between pusher and puller swimmers. In all cases, the viscoelastic swimming speed is below the Newtonian one, with a minimum obtained for intermediate values of the Weissenberg number, We. An analysis of the flow field places the origin of this swimming degradation in non-Newtonian elongational stresses. The power required for swimming is also systematically below the Newtonian power, and always a decreasing function of We. A detail energetic balance of the swimming problem points at the polymeric part of the stress as the primary We-decreasing energetic contribution, while the contributions of the work done by the swimmer from the solvent remain essentially We-independent. In addition, we observe negative values of the polymeric power density in some flow regions, indicating positive elastic work by the polymers on the fluid. The hydrodynamic efficiency, defined as the ratio of the useful to total rate of work, is always above the Newtonian case, with a maximum relative value obtained at intermediate Weissenberg numbers. Finally, the presence of polymeric stresses leads to an increase of the rate of decay of the flow velocity in the fluid, and a decrease of the magnitude of the stresslet governing the magnitude of the effective bulk stress in the fluid.
Mn-doped 0.15BiInO3-0.85PbTiO3 piezoelectric films deposited by pulsed laser deposition
Authors: Lee Sun Young , Ko Song Won , Lee Soonil , Trolier-McKinstry Susan
Published: May 2012

Undoped, 0.5 and 1.0 mol. % Mn-doped 0.15BiInO3-0.85PbTiO3 films were grown on PbTiO3/Pt/Ti/SiO2/Si substrates by pulsed laser deposition. Phase-pure perovskite films were obtained at a substrate temperature of 585 °C irrespective of Mn doping level. The 0.5 mol. % Mn-doped films showed a room temperature permittivity of 480 and a dielectric loss tangent of 0.015 at 100 kHz after 650 °C post-deposition annealing. The coercive field and remanent polarization were 80 kV/cm and 29 µC/cm2, respectively. The ferroelectric transition temperature of the films ranged from 535 to 585 °C. The e31,f piezoelectric coefficient was −7.1 C/m2. X-ray diffraction and phase transition temperature data showed that the Mn atoms substitute on the Ti-site as Mn3+; the resulting films have p-type conduction characteristics.