bluuebunny/crossref_metadata_2025 huggingface dataset:
The parasite-stress theory may be a general theory of culture and sociality
Authors: Fincher Corey L. , Thornhill Randy
Published: January 2012

In the target article, we presented the hypothesis that parasite-stress variation was a causal factor in the variation of in-group assortative sociality, cross-nationally and across the United States, which we indexed with variables that measured different aspects of the strength of family ties and religiosity. We presented evidence supportive of our hypothesis in the form of analyses that controlled for variation in freedom, wealth resources, and wealth inequality across nations and the states of the USA. Here, we respond to criticisms from commentators and attempt to clarify and expand the parasite-stress theory of sociality used to fuel our research presented in the target article.
Mapping Realities: Representing War through Affective Place Making
Authors: Balfour Michael
Published: January 2012

One of the most unusual statistics in the study of performance and war is that aesthetic activity often increases in times of conflict. In this article Michael Balfour extends the consideration of performance and war to aesthetic projects that were located far removed from the centres of conflict, but that deeply connected with the affective impact of war. As an illustration of performative practice, the examples demonstrate the ways in which place making can play with documenting and representing war experiences in different ways. The two examples – This is Camp X-Ray in Manchester (a temporary installation) and the Vietnam Veterans Memorial in Washington DC – were designed in separate contexts for very different purposes; but contribute to understanding the kinds of choices that artists make in representing the affective ‘truths’ of war experience. In both cases, the artists were interested in creating spaces that would make the wars more visible for an audience, and provide a tangible place in which experiences of war could be re-conceived and an affective connection made. Michael Balfour is Professor of Applied Theatre, Griffith University, Brisbane, Australia. His research expertise is in the social applications of theatre, in particular theatre and war, prison theatre, and arts and health. Major Australian Research Council-funded projects include The Difficult Return, on approaches to artsbased work with returning military personnel, and Captive Audiences, on the impact of performing arts programmes in prisons. His books include Theatre and War 1933–1945 and, most recently, Performance in Place of War, co-authored with James Thompson and Jenny Hughes (Seagull Press, 2010).
Mothers' physical abusiveness in a context of violence: Effects on the mother–child relationship
Authors: Timmer Susan G. , Thompson Dianne , Culver Michelle A. , Urquiza Anthony J. , Altenhofen Shannon
Published: January 2012

The purpose of this study was to investigate the effects of mothers' physical abusiveness on the quality of the mother–child relationship, and note how it further varied by their exposure to interparental violence (IPV). The sample consisted of 232 clinic-referred children, aged 2 to 7 years, and their biological mothers. Slightly more than a quarter of the children (N = 63, 27.2%) had been physically abused by their mothers; approximately half of these children also had a history of exposure to IPV (N = 34, 54%). Investigating effects of physical abuse in the context of IPV history on mothers' and children's emotional availability, we found that physically abused children with no IPV exposure appeared less optimally emotionally available than physically abused children with an IPV exposure. However, subsequent analyses showed that although dyads with dual-violence exposure showed emotional availability levels similar those of nonabusive dyads, they were more overresponsive and overinvolving, a kind of caregiving controllingness charasteric of children with disorganized attachment styles. These findings lend some support to the notion that the effects of abuse on the parent–child relationship are influenced by the context of family violence, although the effects appear to be complex.
Emotional relationships between mothers and infants: Knowns, unknowns, and unknown unknowns
Authors: Bornstein Marc H. , Suwalsky Joan T. D. , Breakstone Dana A.
Published: January 2012

An overview of the literature pertaining to the construct of emotional availability is presented, illustrated by a sampling of relevant studies. Methodological, statistical, and conceptual problems in the existing corpus of research are discussed, and suggestions for improving future investigations of this important construct are offered.
The serotonin transporter gene linked polymorphic region is associated with the behavioral response to repeated stress exposure in infant rhesus macaques
Authors: Spinelli Simona , Schwandt Melanie L. , Lindell Stephen G. , Heilig Markus , Suomi Stephen J. , Higley J. Dee , Goldman David , Barr Christina S.
Published: January 2012

The short allele of the serotonin transporter linked polymorphic region (5-HTTLPR) moderates the effects of stress on vulnerability to mood and anxiety disorders. The mechanism by which this occurs may relate to differential sensitivity to stressful life events. Here we explored whether 5-HTTLPR and sex affected behavioral responses to repeated maternal separation in infant rhesus macaques. Behaviors were collected during the acute (Day 1) and the chronic (Days 2–4) phases of the separation, and the effects of duration of separation (acute vs. chronic), genotype (long/long vs. short allele), and sex (male vs. female) on behavioral responses were analyzed across four successive separations. Males increased their levels of locomotion with repeated maternal separation, whereas females exhibited an increase in frequency of self-directed behavior, a measure of “depression-like” behavior. The short-allele predicted increased environmental exploration, particularly during the chronic phase of social separation, indicative of higher arousal. In addition, the short-allele carriers were more likely to increase their levels of self-directed behavior during the chronic phase of separation, as a function of repeated exposures. These findings suggest that the short allele may increase reactivity to repeated, chronic stressors, leaving them more vulnerable to affective psychopathology, with females particularly vulnerable.
Negative emotionality and externalizing problems in toddlerhood: Overreactive parenting as a moderator of genetic influences
Authors: Lipscomb Shannon T. , Leve Leslie D. , Shaw Daniel S. , Neiderhiser Jenae M. , Scaramella Laura V. , Ge Xiaojia , Conger Rand D. , Reid John B. , Reiss David
Published: January 2012

The current study examines the interplay between parental overreactivity and children's genetic backgrounds as inferred from birth parent characteristics on the development of negative emotionality during infancy, and in turn, to individual differences in externalizing problems in toddlerhood. The sample included 361 families linked through adoption (birth parents and adoptive families). Data were collected when the children were 9, 18, and 27 months old. Results indicated links between individual levels and changes in negative emotionality during infancy and toddlerhood to externalizing problems early in the third year of life. Findings also revealed an interaction between birth mother negative affect and adoptive mother overreactive parenting on children's negative emotionality. This Genotype × Environment interaction predicted externalizing problems indirectly through its association with negative emotionality and revealed stronger effects of genetic risk for children with less overreactive parenting from their mothers. Limitations of this study and directions for future research are discussed.
Mothers' depressive symptoms and children's facial emotions: Examining the depression–inhibition hypothesis
Authors: Dix Theodore , Meunier Leah N. , Lusk Kathryn , Perfect Michelle M.
Published: January 2012

Vibrant expression of emotion is the principal means infants and young children use to elicit appropriate and timely caregiving, stimulation, and support. This study examined the depression–inhibition hypothesis: that declines in mothers' support as their depressive symptoms increase inhibit children's emotional communication. Ninety-four mothers and their 14- to 27-month-olds interacted in a university playroom. Based on microanalytic coding of discrete facial displays, results supported three components of the hypothesis. (a) As mothers' depressive symptoms increased, children displayed less facial emotion (more flat affect, less joy, less sadness, less negative). (b) Mothers' low emotional and behavioral support predicted children's low facial communication and mediated relations between mothers' depressive symptoms and children's infrequent emotion. (c) Children who were passive with mothers behaviorally expressed emotion infrequently. Children's passivity mediated relations between mothers' depressive symptoms and children's infrequent emotion displays. Contrary to modeling and contagion theories, mothers' facial displays did not mediate relations between their depressive symptoms and children's facial displays. Nor were the outcomes children experienced regulating their facial displays. Rather, findings suggest that, even when depressive symptoms are modest, young children inhibit emotion as mothers' depressive symptoms increase to withdraw from unresponsive mothers, which may adversely affect children's subsequent relationships and competencies.
Inner speech is used to mediate short-term memory, but not planning, among intellectually high-functioning adults with autism spectrum disorder
Authors: Williams David M. , Bowler Dermot M. , Jarrold Christopher
Published: January 2012

Evidence regarding the use of inner speech by individuals with autism spectrum disorder (ASD) is equivocal. To clarify this issue, the current study employed multiple techniques and tasks used across several previous studies. In Experiment 1, participants with and without ASD showed highly similar patterns and levels of serial recall for visually presented stimuli. Both groups were significantly affected by the phonological similarity of items to be recalled, indicating that visual material was spontaneously recoded into a verbal form. Confirming that short-term memory is typically verbally mediated among the majority of people with ASD, recall performance among both groups declined substantially when inner speech use was prevented by the imposition of articulatory suppression during the presentation of stimuli. In Experiment 2, planning performance on a tower of London task was substantially detrimentally affected by articulatory suppression among comparison participants, but not among participants with ASD. This suggests that planning is not verbally mediated in ASD. It is important that the extent to which articulatory suppression affected planning among participants with ASD was uniquely associated with the degree of their observed and self-reported communication impairments. This confirms a link between interpersonal communication with others and intrapersonal communication with self as a means of higher order problem solving.
Sibling influences on adolescent substance use: The role of modeling, collusion, and conflict
Authors: Low Sabina , Shortt Joann Wu , Snyder James
Published: January 2012

The longitudinal associations of older sibling substance use as well as dyadic sibling conflict and collusion to younger sibling substance use were examined in a community-based sample of 244 same-sex sibling pairs. Indirect effects of older siblings on younger sibling substance use were hypothesized via younger sibling deviant peer affiliation and conflict with friends. Adolescents, parents, friends, and teachers completed measures of substance use, conflict, and deviant peer involvement. Observational data were used for both measures of collusion and conflict. Findings suggest that older sibling substance use has a direct effect on younger sibling use, but relationship dynamics and reinforcement played a significant role as well. Specifically, collusion and conflict in the sibling relationship both had indirect effects through younger siblings’ deviant peer affiliation. Findings validate the powerful socializing role of both siblings and peers, and elucidate the complex mechanisms through which socialization occurs. Furthermore, data underscore the importance of considering how multiple dimensions of socialization operate in the elaboration of antisocial behavior.
Impact of fathers on risky sexual behavior in daughters: A genetically and environmentally controlled sibling study
Authors: Ellis Bruce J. , Schlomer Gabriel L. , Tilley Elizabeth H. , Butler Emily A.
Published: January 2012

Girls receiving lower quality paternal investment tend to engage in more risky sexual behavior (RSB) than peers. Whereas paternal investment theory posits that this effect is causal, it could arise from environmental or genetic confounds. To distinguish between these competing explanations, the current authors employed a genetically and environmentally controlled sibling design (N = 101 sister pairs; ages 18–36), which retrospectively examined the effects of differential sibling exposure to family disruption/father absence and quality of fathering. Consistent with a causal explanation, differences between older and younger sisters in the effects of quality of fathering on RSB were greatest in biologically disrupted families when there was a large age gap between the sisters (thus maximizing differential exposure to fathers), with greater exposure within families to higher quality fathering serving as a protective factor against RSB. Further, variation around the lower end of fathering quality appeared to have the most influence on RSB. In contrast, differential sibling exposure to family disruption/father absence (irrespective of quality of fathering) was not associated with RSB. The differential sibling-exposure design affords a new quasi-experimental method for evaluating the causal effects of fathers within families.
Atmospheric constraints on gross primary productivity and net ecosystem productivity: Results from a carbon‐cycle data assimilation system
Authors: Koffi E. N. , Rayner P. J. , Scholze M. , Beer C.
Published: January 2012

This paper combines an atmospheric transport model and a terrestrial ecosystem model to estimate gross primary productivity (GPP) and net ecosystem productivity (NEP) of the land biosphere. Using atmospheric CO2observations in a Carbon Cycle Data Assimilation System (CCDAS) we estimate a terrestrial global GPP of 146 ± 19 GtC/yr. However, the current observing network cannot distinguish this best estimate from a different assimilation experiment yielding a terrestrial global GPP of 117 GtC/yr. Spatial estimates of GPP agree with data‐driven estimates in the extratropics but are overestimated in the poorly observed tropics. The uncertainty analysis of previous studies was extended by using two atmospheric transport models and different CO2 observing networks. We find that estimates of GPP and NEP are less sensitive to these choices than the form of the prior probability for model parameters. NEP is also found to be significantly sensitive to the transport model and this sensitivity is not greatly reduced compared to direct atmospheric transport inversions, which optimize NEP directly.
Spatiotemporal distribution of the seismicity along the Mid‐Atlantic Ridge north of the Azores from hydroacoustic data: Insights into seismogenic processes in a ridge–hot spot context
Authors: Goslin J. , Perrot J. , Royer J.‐Y. , Martin C. , Lourenço N. , Luis J. , Dziak R. P. , Matsumoto H. , Haxel J. , Fowler M. J. , Fox C. G. , Lau A. T.‐K. , Bazin S.
Published: January 2012

The seismicity of the North Atlantic was monitored from May 2002 to September 2003 by the ‘SIRENA array’ of autonomous hydrophones. The hydroacoustic signals provide a unique data set documenting numerous low‐magnitude earthquakes along the section of the Mid‐Atlantic Ridge (MAR) located in a ridge‐hot spot interaction context. During the experiment, 1696 events were detected along the MAR axis between 40°N and 51°N, with a magnitude of completeness level ofmb≈ 2.4. Inside the array, location errors are in the order of 2 km, and errors in the origin time are less than 1 s. From this catalog, 15 clusters were detected. The distribution of source level (SL) versus time within each cluster is used to discriminate clusters occurring in a tectonic context from those attributed to non‐tectonic (i.e. volcanic or hydrothermal) processes. The location of tectonic and non‐tectonic sequences correlates well with regions with positive and negative Mantle Bouguer Anomalies (MBAs), indicating the presence of thinner/colder and thicker/warmer crust respectively. At the scale of the entire array, both the complete and declustered catalogs derived from the hydroacoustic signals show an increase of the seismicity rate from the Azores up to 43°30′N suggesting a diminishing influence of the Azores hot spot on the ridge‐axis temperature, and well correlated with a similar increase in the along‐axis MBAs. The comparison of the MAR seismicity with the Residual MBA (RMBA) at different scales leads us to think that the low‐magnitude seismicity rates are directly related to along‐axis variations in lithosphere rheology and temperatures.
Air quality over the Canadian oil sands: A first assessment using satellite observations
Authors: McLinden C. A. , Fioletov V. , Boersma K. F. , Krotkov N. , Sioris C. E. , Veefkind J. P. , Yang K.
Published: January 2012

Results from the first assessment of air quality over the Canadian oil sands–one of the largest industrial undertakings in human history–using satellite remote sensing observations of two pollutants, nitrogen dioxide (NO2) and sulfur dioxide (SO2), are presented. High‐resolution maps were created that revealed distinct enhancements in both species over an area (roughly 30 km × 50 km) of intensive surface mining at scales of a few kilometers. The magnitude of these enhancements, quantified in terms of total mass, are comparable to the largest seen in Canada from individual sources. The rate of increase in NO2between 2005 and 2010 was assessed at 10.4 ± 3.5%/year and resulted from increases both in local values as well as the spatial extent of the enhancement. This is broadly consistent with both surface‐measurement trends and increases in annual bitumen production. An increase in SO2 was also found, but given larger uncertainties, it is not statistically significant.
Nonlinear effects of salt concentrations on evaporation from porous media
Authors: Norouzi Rad Mansoureh , Shokri Nima
Published: January 2012

Evaporation from porous media saturated with salt solution is influenced by the interactions among the transport properties of porous media, thermodynamics of the evaporating solution and environmental conditions. To study the effects of salt concentrations on the evaporation dynamics, we conducted a series of evaporation experiments under constant atmospheric conditions using columns packed with sand particles saturated with various NaCl solutions differing in concentrations. Results show that the evaporation rate decreases as NaCl concentration increases only up to a certain level. When exceeding this level, any further increase of NaCl concentration results in higher evaporation rates which is described theoretically using the thermodynamics of the solution. Results also reveal a nonlinear relation between NaCl concentrations and onset of efflorescence which is described by the numerical solution of the classical convection‐diffusion equation. Moreover, we found a strong correlation between the growth dynamics of precipitated salt at the surface and the evaporation rate such that the maximum rate of surface coverage by salt coincide with the end of stage‐1 evaporation. This potentially offers a new method to nondestructively study the evaporation process from saline porous media.
Spectral analysis of flickering aurora
Authors: Michell R. G. , McHarg M. G. , Samara M. , Hampton D. L.
Published: January 2012

We present a case study of a flickering aurora event observed from Poker Flat, Alaska. The data were recorded using an Andor EMCCD narrow field of view (15° × 15°) imager. The images were recorded at 33.58 frames per second resulting in 256 × 256 pixel images. The specific event analyzed consists of a time series of images lasting approximately 30 seconds (1000 images) where flickering aurora was observed throughout the entire sequence. An asymmetry was found in the scale size of the patches, with the East–West direction being approximately twice as large as the North–South direction. The calculation of the spatiotemporal spectra reveals that the temporal frequencies of the luminosity variations occur throughout the well‐defined range of 5 Hz to 14 Hz, with a sharp increase in power around 5 Hz and the peak at approximately 10 Hz. These data are compared to the theoretically calculated dispersion relation for ion cyclotron waves and the observed wave power can be bounded by using a k∥ between 1 × 10−5 m−1 and 3 × 10−5 m−1 for an altitude of 3100 km. Observationally there is a lack of power at values of k⊥ larger than ∼2 × 10−3 m−1, suggesting the existence of a minimum spatial scale for flickering auroral patches of approximately the O+ ion gyroradius (∼1 km) at the interaction altitude.
Comparison of Dst forecast models for intense geomagnetic storms
Authors: Ji Eun‐Young , Moon Y.‐J. , Gopalswamy N. , Lee D.‐H.
Published: January 2012

We have compared six Dst forecast models using 63 intense geomagnetic storms (Dst ≤ −100 nT) that occurred from 1998 to 2006. For comparison, we estimated linear correlation coefficients and RMS errors between the observed Dst data and the predicted Dst during the geomagnetic storm period as well as the difference of the value of minimum Dst (ΔDstmin) and the difference in the absolute value of Dst minimum time (ΔtDst) between the observed and the predicted. As a result, we found that the model by Temerin and Li (2002, 2006) gives the best prediction for all parameters when all 63 events are considered. The model gives the average values: the linear correlation coefficient of 0.94, the RMS error of 14.8 nT, the ΔDstmin of 7.7 nT, and the absolute value of ΔtDst of 1.5 hour. For further comparison, we classified the storm events into two groups according to the magnitude of Dst. We found that the model of Temerin and Lee (2002, 2006) is better than the other models for the events having −100 ≤ Dst < −200 nT, and three recent models (the model of Wang et al. (2003), the model of Temerin and Li (2002, 2006), and the model of Boynton et al. (2011b)) are better than the other three models for the events having Dst ≤ −200 nT.
A multiyear (2002–2006) climatology of O/N2 in the lower thermosphere from TIMED GUVI and ground‐based photometer observations
Authors: Hecht J. H. , Mulligan T. , Correira J. T. , Clemmons J. H. , Strickland D. J. , Walterscheid R. L. , Conde M. G.
Published: January 2012

The Mass Spectrometer and Incoherent Scatter (MSIS) series of models has been a standard for specification and prediction of conditions in the Earth's thermosphere. One aspect of the model that has not been well validated is its predictions of the lower thermospheric compositional response to varying periodic and transient solar and geomagnetic forcings. Here we compare the predictions by the NRLMSIS model over the years 2002 to 2006 for column O/N2 with GUVI satellite (daytime) observations at a fixed longitude of the Poker Flat Research Range in central Alaska. NRLMSIS predictions are also compared with nightside auroral O/N2 observations obtained from ground‐based photometric measurements from central Alaska. While there is often good agreement between the GUVI and NRLMSIS O/N2 at high latitudes, there are also times during large geomagnetic storms when there is some disagreement with the largest occurring at midlatitudes. The 9‐day periodicity, first described in 2007 and attributed to high‐speed solar wind streams, is present in the model at all latitudes but is quite weak in the observations below 55N latitude. Away from high‐latitudes, these differences may exist because the NRLMSIS O/N2 dependence on ap forces nonperiodic contributions contained in the NRLMSIS database to give a periodic response when ap is varied periodically. While the nighttime observations show considerable agreement with NRLMSIS they are much more variable than predicted by the model. This variability suggests that there are significant local effects in the auroral zone that are not captured by the model.
Formation, shape, and evolution of magnetic structures in CIRs at 1 AU
Authors: Broiles T. W. , Desai M. I. , McComas D. J.
Published: January 2012

We have surveyed the properties of 153 co‐rotating interaction regions (CIRs) observed at 1 AU from January, 1995 through December, 2008. We identified that 74 of the 153 CIRs contain planar magnetic structures (PMSs). For planar and non‐planar CIRs, we compared distributions of the bulk plasma and magnetic field parameters. Our identification of CIRs and their features yields the following results: (1) The different pressures within CIRs are strongly correlated. (2) There is no statistical difference between planar and non‐planar CIRs in the distributions and correlations between bulk plasma and magnetic field parameters. (3) The mean observed CIR azimuthal tilt is within 1 σ of the predicted Parker spiral at 1 AU, while the mean meridional tilt is about 20°. (4) The meridional tilt of CIRs changes from one solar rotation to the next, with no relationship between successive reoccurrences. (5) The meridional tilt of CIRs in the ecliptic is not ordered by the magnetic field polarity of the parent coronal hole. (6) Although solar wind deflection is a function of CIR shape and speed, the relationship is not in agreement with that predicted by Lee (2000). We conclude the following: (1) PMSs in CIRs are not caused by a unique characteristic in the local plasma or magnetic field. (2) The lack of relationship between CIR tilt and its parent coronal hole suggests that coronal hole boundaries may be more complex than currently observed. (3) In general, further theoretical work is necessary to explain the observations of CIR tilt.
Statistical characteristics of small‐scale spatial and temporal electric field variability in the high‐latitude ionosphere
Authors: Cousins E. D. P. , Shepherd S. G.
Published: January 2012

The statistical characteristics of small‐scale spatial and temporal electric field variability in the high‐latitude regions of Earth's ionosphere are investigated using 48 months of data from the Super Dual Auroral Radar Network (SuperDARN) radars in both hemispheres. Electric field fluctuations on spatial scales between 45 km and 450 km and on temporal scales between 2 min and 20 min are considered. It is found that both the distribution shapes and scale‐size dependencies of the fluctuations are consistent with the expected properties of a turbulent flow. The observed spatial and temporal variability is influenced primarily by the magnitude of the shear or gradient in the background plasma drift and by season and solar cycle, suggesting plasma instabilities and gradients in the conductance as sources of the electric field variability. The relationship between spatial and temporal variability is investigated and it is found that the fluctuations are likely to be a mixture of convecting static and time‐varying structures. It is also observed that the small‐scale variability has statistical characteristics that are very similar in the two hemispheres. For practical purposes, although a stretched exponential function best matches the data, the distribution of observed electric field fluctuations can be approximated using an exponential function, enabling straightforward generation of nearly realistic random fluctuations.
Evaluation of an ice cloud parameterization based on a dynamical‐microphysical lifetime concept using CloudSat observations and the ERA‐Interim reanalysis
Authors: Ma H.‐Y. , Köhler M. , Li J.‐L. F. , Farrara J. D. , Mechoso C. R. , Forbes R. M. , Waliser D. E.
Published: January 2012

This study validates the cloud ice water content (IWC, non‐precipitating ice/non‐snow) produced by a unique prognostic cloud ice parameterization when used in the UCLA atmospheric general circulation model against CloudSat observations, and also compares it with the ERA‐Interim reanalysis. A distinctive aspect of this parameterization is the novel treatment of the conversion of cloud ice to precipitating snow. The ice‐to‐snow autoconversion time scale is a function of differential infrared radiative heating and environmental static stability. The simulated IWC is in agreement with CloudSat observations in terms of its magnitude and three‐dimensional structure. The annual and seasonal means of the zonal‐mean IWC profiles from the simulations both show a local maximum in the upper troposphere in the tropics associated with deep convection, and other local maxima in the mid‐troposphere in midlatitudes in both hemispheres associated with storm tracks. In contrast to the CloudSat values, the reanalysis shows much smaller IWC values in the tropics and much larger values in the lower troposphere in midlatitudes. The different vertical structures and magnitudes of IWC between the simulations and the reanalysis are likely due to differences in the parameterization of various processes in addition to the ice‐to‐snow autoconversion, including ice sedimentation, temperature thresholds for ice deposition and cumulus detrainment of cloud ice. However, a series of sensitivity experiments supports the conclusion that the model with a constant autoconversion time scale cannot reproduce the correct IWC distribution in both the tropics and midlatitudes, which strongly suggests the importance of physically based effects on the autoconversion timescale.
The distinct behaviors of Pacific and Indian Ocean warm pool properties on seasonal and interannual time scales
Authors: Kim Seon Tae , Yu Jin‐Yi , Lu Mong‐Ming
Published: January 2012

The seasonal and interannual variabilities of warm pool properties in the Pacific and Indian Ocean sectors are examined and contrasted. The properties examined are the size, mean and maximum sea surface temperatures (SSTs), and central position. The seasonal variability is more vigorous in the Indian Ocean sector, but the interannual variability is comparable in the Pacific and Indian Ocean sectors. The variability is associated with significant longitudinal and latitudinal displacements on seasonal time scales but only with longitudinal displacements on interannual time scales. As for the controlling factors, while the seasonal variability of the warm pool is controlled by the annual march of the Sun in the Pacific sector and by the Indian summer monsoon in the Indian Ocean sector, the interannual variability in both sectors is related mostly to El Niño–Southern Oscillation (ENSO). ENSO is closely correlated with the size variations and longitudinal displacements of the warm pool. Interestingly, the warm pool intensity in both sectors is not highly correlated with ENSO until 5 to 6 months after ENSO peaks. The possible causes of this delayed ENSO influence are discussed. Only size and intensity (i.e., mean SST) variations in the Indian Ocean warm pool are significantly correlated with quasi‐biennial variability in the Indian monsoon, which indicates that the Indian Ocean warm pool may be a potential predictor for Indian monsoon variations.
Importance of aerosol composition, mixing state, and morphology for heterogeneous ice nucleation: A combined field and laboratory approach
Authors: Baustian Kelly J. , Cziczo Daniel J. , Wise Matthew E. , Pratt Kerri A. , Kulkarni Gourihar , Hallar A. Gannet , Tolbert Margaret A.
Published: January 2012

In this study chemical compositions of background aerosol and ice nuclei were examined through laboratory investigations using Raman spectroscopy and field measurements by single‐particle mass spectrometry. Aerosol sampling took place at Storm Peak Laboratory in Steamboat Springs, Colorado (elevation of 3210 m). A cascade impactor was used to collect coarse‐mode aerosol particles for laboratory analysis by Raman spectroscopy; the composition, mixing state, and heterogeneous ice nucleation activity of individual particles were examined. For in situ analysis of fine‐mode aerosol, ice nucleation on ambient particles was observed using a compact ice nucleation chamber. Ice crystals were separated from unactivated aerosol using a pumped counterflow virtual impactor, and ice nuclei were analyzed using particle analysis by laser mass spectrometry. For both fine and coarse modes, the ice nucleating particle fractions were enriched in minerals and depleted in sulfates and nitrates, compared to the background aerosol sampled. The vast majority of particles in both the ambient and ice active aerosol fractions contained a detectable amount of organic material. Raman spectroscopy showed that organic material is sometimes present in the form of a coating on the surface of inorganic particles. We find that some organic‐containing particles serve as efficient ice nuclei while others do not. For coarse‐mode aerosol, organic particles were only observed to initiate ice formation when oxygen signatures were also present in their spectra.
Detecting tropical thin cirrus using Multiangle Imaging SpectroRadiometer's oblique cameras and modeled outgoing longwave radiation
Authors: Prasad Abhnil Amtesh , Davies Roger
Published: January 2012

We report the improved detection of thin cirrus clouds over the Tropics using oblique camera stereo retrieval of cloud top heights from the Multiangle Imaging SpectroRadiometer (MISR) instrument on the Terra satellite. The MISR oblique stereo captures 10% of thin cirrus with mean height of 13 km over all scenes that the standard stereo misses completely, especially when they are over lower‐level clouds that provide more contrast. To determine thin cirrus properties missed by MISR, differences between modeled and measured outgoing longwave radiation (OLR) were used to compute its fractional cover and optical depth. The oblique MISR measurements were used as inputs to the model and a merged data set from CERES, MODIS and MISR instruments on the Terra satellite provided the measured fluxes and the cloud properties. For the cases investigated including all clear and cloudy scenes in the Tropics, the difference between modeled and measured OLR (Cirrus Forcing) averaged ≈ 19 W m−2. This can be accounted for by the addition of thin cirrus of coverage 77%. However, oblique analysis only detects 10% of thin cirrus (0.1 < τ < 0.3) and misses 67% of cirrus with τ < 0.3. The missed cirrus coverage includes 32% of homogeneous cirrus (0.1 < τ < 0.3) and 35% of subvisual cirrus (τ < 0.1). To improve the detection of homogeneous cirrus with MISR, the current contrast threshold should be decreased. This will increase the number of pixels to be matched stereoscopically that were screened as noise initially.
Dispersion of the volcanic sulfate cloud from a Mount Pinatubo–like eruption
Authors: Aquila Valentina , Oman Luke D. , Stolarski Richard S. , Colarco Peter R. , Newman Paul A.
Published: January 2012

We use the GEOS‐5 general circulation model to simulate the transport of the volcanic cloud from an eruption similar to the 1991 eruption of Mount Pinatubo. The simulated aerosol optical thickness and transport of the volcanic cloud are in good agreement with observations of the actual Pinatubo eruption from the Stratospheric Aerosol and Gas Experiment II (SAGE II) and the Advanced Very High Resolution Radiometer (AVHRR) and with vertical profiles of sulfur dioxide observed by the Microwave Limb Sounder (MLS). We tested the importance of initial conditions corresponding to the specific meteorological situation at the time of the eruption by comparing results when GEOS‐5 is initialized using Modern Era Retrospective Analyses for Research and Applications (MERRA) reanalysis fields with results when it is initialized from an existing model run. We found no significant difference in the transport of the cloud. We show how the inclusion of the interaction between volcanic sulfate aerosol and radiation is essential for a reliable simulation of the transport of the volcanic cloud. The absorption of longwave radiation by the volcanic sulfate largely induces the rising of the volcanic cloud up to the middle stratosphere and the divergent motion from the latitude of the eruption to the tropics. Our simulations indicate that the cloud is transported to the Northern Hemisphere through a lower stratospheric pathway and to middle and high latitudes of the Southern Hemisphere through a middle stratospheric pathway, centered at about 30 hPa. The direction of the middle stratospheric pathway depends on the season of the eruption.
Ice particle growth in the presence of nitric oxide
Authors: Peterson Harold , Hallett John
Published: January 2012

An experimental study was undertaken to examine the effects of nitric oxide (NO) on ice crystal growth. This study focused on growth rates and ice crystal habit. A chamber was used to grow ice at controlled temperature and supersaturation, and images of ice crystals were obtained using a video camera. Ice crystals grow more quickly when NO concentrations are elevated above background to 370 and 710 ppb and lengthen (c‐axis growth) more quickly than they thicken (a‐axis growth). The results have implications for ice crystal growth in thunderstorms and may aid in determining whether an air parcel in a thunderstorm originated from an electrically active region.
On the dependence of albedo on cloud microphysics over marine stratocumulus clouds regimes determined from Clouds and the Earth's Radiant Energy System (CERES) data
Authors: Painemal David , Minnis Patrick
Published: January 2012

The dependence of the top‐of‐the‐atmosphere (TOA) albedo A on cloud microphysical properties was investigated for the three largest maritime stratocumulus clouds regimes: off California, Southeast Pacific (Chile‐Peru), and southwest Africa (Namibia‐Angola). Absolute S and relative SR albedo susceptibilities to perturbations in cloud droplet number concentrations Nd, defined as dA/dNd and dA/dln(Nd) respectively, were calculated for the season having maximum cloud cover during the period 2006–2010. Satellite‐based susceptibilities were computed by combining an adiabatically based Nd estimate and liquid water path (LWP) derived from Terra Moderate Resolution Imaging Spectroradiometer (MODIS) retrievals matched with TOA A from the Clouds and the Earth's Radiant Energy System. Empirical susceptibility maps were calculated for three constant LWP intervals at 25, 50, and 90 g−2. It was found that S increases with LWP, with small and spatially homogeneous values for low LWP, and a contrasting increase far offshore for larger LWP values. An overall increase of SR with LWP was also observed, with larger values near the coast for LWP = 25 and 50 g−2. A relatively homogeneous spatial pattern of maximum SR values covered most of each regime's domain for a LWP of 90 g−2. These results highlight the importance of LWP in modulating the albedo susceptibility. The dependencies of S and SR on LWP are mostly explained by variations in the mean Nd and cloud optical thickness (τ), with an increase of S with LWP linked to a decrease in Nd, whereas SR increased with τ and A, until reaching a maximum for A and τ near 0.36–0.4 and 12–14 respectively, and decreasing thereafter, consistent with expectations based on two‐stream estimates. Larger SR values in the Southeast Pacific are thought to be the consequence of a drier and more pristine atmosphere. Radiative transfer simulations with realistic values of above‐cloud water vapor path and aerosol optical thickness showed that differing atmospheric compositions could explain why the Chile‐Peru regime was the marine stratocumulus cloud deck most susceptible to change its TOA albedo due to fractional changes in Nd.
Is the origin of type 1 diabetes in the gut?
Authors: Vaarala Outi
Published: January 2012

In type 1 diabetes, insulin‐producing beta‐cells in the pancreas are destroyed by immune‐mediated mechanisms. The manifestation of the disease is preceded by the so‐called pre‐diabetic period that may last several years and is characterized by the appearance of circulating autoantibodies against beta‐cell antigens. The role of the gut as a regulator of type 1 diabetes was suggested in animal studies, in which changes affecting the gut immune system modulated the incidence of diabetes. Dietary interventions, alterations in the intestinal microbiota and exposure to enteric pathogens, regulate the development of autoimmune diabetes in animal models. It has been demonstrated that these modulations affect the gut barrier mechanisms and intestinal immunity. Because the pancreas and the gut belong to the same intestinal immune system, the link between autoimmune diabetes and the gut is not unexpected. The gut hypothesis in the development of type 1 diabetes is also supported by the observations made in human type 1 diabetes. Early diet could modulate the development of beta‐cell autoimmunity; weaning to hydrolysed casein formula decreased the risk of beta‐cell autoimmunity by age 10 in the infants at genetic risk. Increased gut permeability, intestinal inflammation with impaired regulatory mechanisms and dysregulated oral tolerance have been observed in children with type 1 diabetes. The factors that contribute to these intestinal alterations are not known, but interest is focused on the microbial stimuli and function of innate immunity. It is likely that our microbial environment does not support the healthy maturation of the gut and tolerance in the gut, and this leads to the increasing type 1 diabetes as well as other immune‐mediated diseases regulated by intestinal immune system. Thus, the interventions, aiming to prevent or treat type 1 diabetes in humans, should be targeting the gut immune system.
The Evolutionary Seesaw: Origins of biodiversity?
Authors: Boettiger Carl
Published: January 2012

I consider the problem of evolutionary branching in adaptive dynamics without applying the limits of separation of timescales between ecological and evolutionary processes. I derive expressions for the waiting time for a branching event to occur and survive in terms of both ecological and evolutionary parameters, and show how demographic stochasticity alone can result in the frequent failure of adaptive branching.
p53 Ser15 phosphorylation disrupts the p53–RPA70 complex and induces RPA70-mediated DNA repair in hypoxia
Authors: Madan Esha , Gogna Rajan , Pati Uttam
Published: January 2012

Cellular stressors are known to inhibit the p53–RPA70 (replication protein A, 70 kDa subunit) complex, and RPA70 increases cellular DNA repair in cancer cells. We hypothesized that regulation of RPA70-mediated DNA repair might be responsible for the inhibition of apoptosis in hypoxic tumours. We have shown that, in cancer cells, hypoxia disrupts the p53–RPA70 complex, thereby enhancing RPA70-mediated NER (nucleotide excision repair)/NHEJ (non-homologous end-joining) repair. In normal cells, RPA70 binds to the p53-NTD (N-terminal domain), whereas this binding is disrupted in hypoxia. Phosphorylation of p53-NTD is a crucial event in dissociating both NTD–RPA70 and p53–RPA70 complexes. Serial mutations at serine and threonine residues in the NTD confirm that p53Ser15 phosphorylation induces dissociation of the p53–RPA70 complex in hypoxia. DNA-PK (DNA-dependent protein kinase) is shown to induce p53Ser15 phosphorylation, thus enhancing RPA70-mediated NER/NHEJ repair. Furthermore, RPA70 gene silencing induces significant increases in cellular apoptosis in the resistant hypoxic cancer cells. We have thus elucidated a novel pathway showing how DNA-PK-mediated p53Ser15 phosphorylation dissociates the p53–RPA70 complex, thus enhancing NER/NHEJ repair, which causes resistance to apoptosis in hypoxic cancer cells. This novel finding may open new strategies in developing cancer therapeutics on the basis of the regulation of RPA70-mediated NER/NHEJ repair.
Transient exposure to sodium butyrate after germinal vesicle breakdown improves meiosis but not developmental competence in pig oocytes
Authors: Liu Limei , Song Guangqi , Gao Fei , Guan Jiyu , Tang Bo , Li Ziyi
Published: January 2012

Oocyte maturation is a complex process during which epigenetic modifications are dramatically changed, especially histone acetylation and phosphorylation. We have investigated the effects of NaBu (sodium butyrate), a natural HDAC (histone deacetylase) inhibitor, on porcine oocyte maturation at different stages and subsequent embryonic development to improve IVF (in vitro fertilization) and embryo production. COCs (cumulus oocyte complexes) were cultured, IVM (in vitro maturation) supplemented with 1 mM NaBu before or after GVBD [GV (germinal vesicle) breakdown] during maturation. NaBu delayed oocyte meiosis in the GV and GVBD stages in an exposure‐dependent manner. However, the short treatment with 1 mM NaBu after GVBD significantly improved the meiotic competence. No positive effects of NaBu on GSH levels and subsequent embryonic development following IVF were seen. Transient exposure to NaBu after GVBD improves meiotic competence, but not subsequently, probably by having an effect on histone acetylation during oocyte maturation.
Titanium Mesh Reconstruction of Orbital Roof Fracture with Traumatic Encephalocele: A Case Report and Review of Literature
Authors: Mokal Nitin J. , Desai Mahinoor F.
Published: January 2012

Orbital roof fractures are rare. Traumatic encephaloceles in the orbital cavity are even rarer, with only 21 cases published to date. Orbital roof fractures are generally encountered in males between 20 and 40 years of age following automobile collision. We report a case of an orbital roof fracture with traumatic encephalocele into the left orbit. Early diagnosis and treatment are very important because the raised intraorbital pressure may irreversibly damage the optic nerve. Computed tomography with 3-D reconstruction, the imaging modality of choice, showed the displaced fracture fragment deep into the orbit. Reconstruction of the orbital roof should be performed in every case. We used an extracranial approach to elevate the fracture with titanium mesh to stabilize the fragment. The cosmetic results were excellent but delay in treatment was responsible for delayed recovery of vision. The case report is followed by a brief overview of orbital roof fractures including pertinent review of literature.
Transformation kinetics of an intrinsic bistable defect in damaged silicon
Authors: Fleming R. M. , Seager C. H. , Lang D. V. , Campbell J. M.
Published: January 2012

The positions of the electronic levels of an intrinsic bistable defect have been measured using deep level transient spectroscopy (DLTS) in n- and p-type damaged silicon bipolar transistor diodes after minority carrier injection and thermal annealing. The kinetic rates observed during conversion of this defect have been determined using both DLTS and transistor gain measurements on devices irradiated with electrons and neutrons. First order conversion kinetics are observed during both injection and thermal annealing of this defect in electron damaged transistors, but more complicated, stretched-out kinetics are seen in neutron irradiated devices. The latter behavior can be successfully modeled as a small spread in the energy barriers for atomic displacements of this defect probably due to strain or electrostatic variations expected in damage clusters. The measured injection bias dependence of the recombination-driven transition to the bistable state of this defect is unlike that seen for generation-recombination currents at deep trap levels, but it is consistent with Shockley—Read–Hall predictions for recombination at shallow states. This latter behavior is expected from the lone shallow peak seen in DLTS measurements of the stable state of this center. Some comparisons of the present results with existing models of this defect are made.