bluuebunny/crossref_metadata_2025 huggingface dataset:
The bushmeat market in Kisangani, Democratic Republic of Congo: implications for conservation and food security
Authors: van Vliet Nathalie , Nebesse Casimir , Gambalemoke Sylvestre , Akaibe Dudu , Nasi Robert
Published: March 2012

Given the important contribution of urban consumption in bushmeat trade, information on bushmeat sales in urban markets can provide valuable insights for understanding the dynamics of this trade and its implications for conservation and food security. We monitored bushmeat traded in the market of Kisangani (the provincial capital of the Province Orientale in the Democratic Republic of Congo) and compared data collected in surveys in 2002 and 2008–2009. In both periods more than two-thirds of the carcasses sold were of rodents and ungulates. From 2002 to 2008–2009 the number of carcasses increased by 44% but the equivalent biomass by only 16% because of a significant decrease in medium-sized species (10–50 kg) and an increase in small species (<10 kg). The number of carcasses of large species increased between the two periods and those of diurnal monkeys increased fourfold. In both periods smoked bushmeat was one of the cheapest sources of protein available year-round, together with caterpillars, which were only available during the rainy season, and pork. Prices of other domestic meat were significantly higher. This study identified an increase in the market of highly threatened species such as okapiOkapia johnstoniand small diurnal monkeys and the continued presence of protected species, and also highlights the food security role that bushmeat plays for poor urban people who cannot afford alternative sources of protein.
First census of the white-shouldered ibis Pseudibis davisoni reveals roost-site mismatch with Cambodia's protected areas
Authors: Wright Hugh L. , Collar Nigel J. , Lake Iain R. , Norin Net , Vann Rours , Ko Sok , Phearun Sum , Dolman Paul M.
Published: March 2012

The population size of the Critically Endangered white-shouldered ibis Pseudibis davisoni has always been poorly known. The first-ever census across Cambodia in 2009–2010 using simultaneous counts at multiple roost sites found substantially more birds than previously estimated, with a minimum of 523 individuals. The census allowed us to make a revised global population estimate of 731–856 individuals, increasing hope for the species' long-term survival. However, the largest subpopulations are imminently threatened by development and c. 75% of the birds counted in Cambodia were outside protected areas.
Determination of geomorphological and volumetric variations in the 1970 land volcanic craters area (Deception Island, Antarctica) from 1968 using historical and current maps, remote sensing and GNSS
Authors: Berrocoso M. , Torrecillas C. , Jigena B. , Fernández-Ros A.
Published: March 2012

During the nearly 40 years covered by the study, major height differences of over ± 25 m have been revealed in the volcanic landscape of the 1970 craters in Deception Island, an active volcano in the South Shetland Islands (West Antarctica). In the last 14 years, the mean volcanic filling rate has been 1 m yr-1 and the mean erosion rate has been -0.2 m yr-1. There has been considerable landform modification mainly associated with landslide-induced accumulation, and erosion may indicate the craters’ fill over the next 30–40 years. Deception Island's eruptions have been recorded since 1842. Special attention was paid to the zones affected by the most recent volcanic events and the geomorphological changes that have taken place in those zones since then (e.g. the 1970 volcanic craters area in the last episode occurring between 1967 and 1970). Historical maps (produced before and just after the 1970 eruption) were compared with maps plotted in 1992 and updated using a 2003 image from the Quickbird satellite and data obtained with Global Navigation Satellite System technology in 2006. Techniques used included both geodetic transformation and the geometric correcting of maps.
Anxiety disorders in older people
Authors: Lindesay James , Stewart Robert , Bisla Jatinder
Published: March 2012

This article reviews the research into anxiety disorders in adults aged 65 years and older that has been published over the past ten years. The topics covered include: the construct of anxiety and its disorders in this age group; epidemiology, including prevalence, incidence, course, outlook, and risk factors; assessment scales; co-morbidity and differential diagnosis (depression, dementia, physical illness); and management, both pharmacological and non-pharmacological. There has been a significant improvement in our understanding of these disorders in older adults over this period, but evidence to support their treatment and prevention is still quite sparse.
Single-catheter radiofrequency ablation of a permanent junctional reciprocating tachycardia in a premature neonate
Authors: Femenía Francisco , Sarquella-Brugada Georgia , Brugada Josep
Published: March 2012

A 34-week premature neonate presented with drug-refractory permanent junctional incessant tachycardia and haemodynamic compromise. The patient underwent successful radiofrequency catheter ablation using a single-catheter approach. The child remains in sinus rhythm, without pharmacological treatment, 2 years after the procedure.
Fatness is not a factor of fitness: analysis of cardiorespiratory data from healthy children over an 8-year period
Authors: Brothers Julie , McBride Michael , Paridon Alex , Zhang Xuemei , Paridon Stephen
Published: March 2012

Purpose

To evaluate exercise performance and body mass index in healthy children over an 8-year period in order to determine whether cardiorespiratory fitness has decreased relative to changes in body mass index in our patient population.

Method

This study is a retrospective review of anthropometric and cardiorespiratory fitness data from our hospital's Exercise Physiology Laboratory's database on 1201 healthy children (6–18 years) with structurally normal hearts who performed one cycle ergometry test between 1999 and 2006. Subjects were stratified by gender and age. Body mass index was compared between 1999–2002 (Early Group) and 2003–2006 (Late Group) and with national averages. Exercise outcome variables were maximal oxygen consumption, anaerobic threshold, physical working capacity indexed to body weight. Analysis of variance was used to detect differences between groups for each outcome variable.

Results

Body mass index was not significantly different from national data (p-value equals 0.79) or between groups. A negative trend (p-value greater than 0.15 less than 0.20) was observed among most indices of exercise performance between Early and Late Groups. Significantly lower anaerobic threshold was found among males between Early and Late Group (25.7 plus or minus 0.9 versus 23.4 plus or minus 1.6 millilitres per kilogram per minute, p-value less than 0.01), and in physical working capacity among females between Early and Late Groups (2.9 plus or minus 0.1 versus 2.7 plus or minus 0.1, p-value less than 0.05).

Conclusions

Cardiorespiratory fitness in males and working capacity in females declined over time independent of body mass index. This suggests that other measures may need to be evaluated for promotion of overall cardiovascular health.
Health labelling can influence taste perception and use of table salt for reduced-sodium products
Authors: Liem Djin Gie , Miremadi Fatemeh , Zandstra Elizabeth H , Keast Russell SJ
Published: March 2012

Objective

To investigate the effect of front-of-pack labels on taste perception and use of table salt for currently available and sodium-reduced soups.

Design

Within-subject design.

Setting

Sensory laboratory.

Subjects

Participants (n 50, mean age 34·8 (sd 13·6) years) were randomly served nine soups (250 ml each) across 3 d. Servings differed in: (i) health label (i.e. no health label, reduced-salt label or Heart Foundation Tick); and (ii) sodium reduction (no reduction – benchmark, 15 % less sodium or 30 % less sodium). Before tasting, participants rated their expected salt intensity and liking. After tasting, participants rated their perceived salt intensity and liking, after which they could add salt to the soup to make it more palatable.

Results

Reduced-salt labels generated a negative taste expectation and actual taste experience in terms of liking (P < 0·05) and perceived saltiness (P < 0·05). Perceived saltiness of sodium-reduced soups decreased more (P < 0·05), and consumers added more salt (P < 0·05), when soups carried the reduced-salt label. The tick logo and soups without health labels had no such influence on taste perception.

Conclusions

Emphasizing salt reduction by means of a front-of-pack label can have a negative effect on taste perception and salt use, especially when consumers are able to taste differences between their regular soup and the sodium-reduced soup. Overall health logos which do not emphasize the reduction in salt are less likely to affect perceived salt intensity and therefore are viable solutions to indicate the healthiness of sodium-reduced products.
Effects of a 2-year healthy eating and physical activity intervention for 3–6-year-olds in communities of high and low socio-economic status: the POP (Prevention of Overweight among Pre-school and school children) project
Authors: De Coen Valerie , De Bourdeaudhuij Ilse , Vereecken Carine , Verbestel Vera , Haerens Leen , Huybrechts Inge , Van Lippevelde Wendy , Maes Lea
Published: March 2012

Objective

The purpose of the present study was to evaluate the effects of a school-based, 2-year, multi-component intervention on BMI, eating and physical activity behaviour in Flanders, Belgium, targeting children aged 3–6 years in communities of high and low socio-economic status (SES).

Design

Cluster-randomized controlled trial.

Setting

Thirty-one pre-primary and primary schools in three different intervention communities and three paired-matched (on SES profile) control communities in Flanders, Belgium.

Subjects

BMI Z-scores at baseline and follow-up were calculated for 1102 children. Questionnaires with sociodemographic data and FFQ were available from 694 of these 1102 children.

Results

No significant effects were found on BMI Z-scores for the total sample. However, there was a significant decrease in BMI Z-score of 0·11 in the low-SES intervention community compared with the low-SES control community, where the BMI Z-score increased by 0·04 (F = 6·26, P = 0·01). No significant intervention effects could be found for eating behaviour, physical activity or screen-time. There were no significant interaction effects of age and gender of the children on the outcome variables.

Conclusions

Although no significant effects were found for BMI Z-scores in the total sample, this intervention had a promising effect in the low-SES community of reducing excess weight gain among young children.
Listeria monocytogenes and diet during pregnancy; balancing nutrient intake adequacy v. adverse pregnancy outcomes
Authors: Pezdirc Kristine B , Hure Alexis J , Blumfield Michelle L , Collins Clare E
Published: March 2012

Objective

To evaluate the impact of adherence to public health recommendations on Listeria monocytogenes food safety to limit exposure to potential food sources on micronutrient intakes of pregnant women and whether more frequent consumption of ‘high-risk’ foods increases risk for adverse pregnancy outcomes.

Design

A cohort study in women assessing Listeria exposure from an FFQ based on consumption of potential Listeria-containing food sources, the Listeria Food Exposure Score (LFES). Pregnancy status was defined as pregnant, trying to conceive, had a baby within the previous 12 months, or other. Nutrient intakes were compared with Nutrient Reference Values and self-reported pregnancy outcome history three years later.

Setting

Australia.

Subjects

Women aged 25–30 years (n 7486) participating in the Australian Longitudinal Study on Women's Health.

Results

There were weak positive correlations (r = 0·13–0·37, P < 0·001) between LFES and all nutrients, with fibre, folate, Fe and vitamin E intakes consistently below the Nutrient Reference Values in every quintile of LFES. Women in the highest quintile of LFES reported 19 % more miscarriages (rate ratio = 1·19; 95 % CI 1·02, 1·38) than those in the lowest quintile, after adjusting for important confounding factors.

Conclusions

More frequent consumption of foods potentially containing L. monocytogenes is associated with higher nutrient intakes, but an increased risk of miscarriage. L. monocytogenes pregnancy recommendations require review and should include the list of ‘risky’ food items in addition to low-risk alternatives that would adequately replace nutrient intakes which may be reduced through avoidance strategies.
Outsourcing, Offshoring, Nearshoring, Onshoring – What's Going On?
Authors: Worley Loyita
Published: March 2012

Loyita Worley outlines recent developments among law firms where outsourcing has been embraced in relation to their library, information and knowledge functions and services. She defines the terms and themes of the subject – outsourcing, offshoring, nearshoring and onshoring – and offers some thoughts for the future of legal information services in the commercial sector.
Genetic diversity of bean (Phaseolus) landraces and wild relatives from the primary centre of origin of the Southern Andes
Authors: Avila Teresa , Blair Matthew W. , Reyes Ximena , Bertin Pierre
Published: March 2012

The Southern Andes, especially the inter-Andean valleys of south Bolivia, is thought to be a probable point of domestication within the primary centre of diversity for Andean common beans (Phaseolus vulgarisL.). The nationalPhaseolusgermplasm collection of Bolivia is maintained by the Pairumani Foundation and consists of 449 accessions where most of the accessions are of common bean but some are of related cultivated and wild species. The goal of this study was to determine the genetic diversity of this collection by sampling 174 accessions ofP. vulgarisand an outgroup of eightPhaseolus augusti, twoPhaseolus lunatusand onePhaseolus coccineusgenotype. The genetic diversity and population structure were estimated using 29 microsatellite markers. High levels of polymorphism were found, with a total of 311 alleles identified and an average of 10.7 alleles per marker. Correspondence analysis and an unweighted pair group method with arithmetic mean-based dendrogram distinguishedP. vulgarisfrom the other species ofPhaseolus. Common bean accessions were separated into two groups: the first one including Andean controls and most accessions from high altitudes with morphological characteristics and growth habits typical of this gene pool; the second one including Mesoamerican controls and accessions from low altitudes. Inside the Andean gene pool, the wild accessions were diverse and separated from the weedy and cultivated accessions. Low geographical distances between collection sites (up to 100 km) were shown to be related to low genetic distances. These results are important for the conservation of common beans in the Southern Andes.
Modality Specificity of Comprehension Abilities in the Sciences
Authors: Schroeders Ulrich , Bucholtz Nina , Formazin Maren , Wilhelm Oliver
Published: March 2012

The measurement of science achievement is often unnecessarily restricted to the presentation of reading comprehension items that are sometimes enriched with graphs, tables, and figures. In a newly developed viewing comprehension task, participants watched short videos covering different science topics and were subsequently asked several multiple-choice comprehension questions. Research questions were whether viewing comprehension (1) can be measured adequately, (2) is perfectly collinear with reading comprehension, and (3) can be regarded as a linear function of reasoning and acquired knowledge. High-school students (N = 216) worked on a paper-based reading comprehension task, a viewing comprehension task delivered on handheld devices, a sciences knowledge test, and three fluid intelligence measures. The data show that, first, the new viewing comprehension test worked psychometrically fine; second, performance in both comprehension tasks was essentially perfectly collinear; third, fluid intelligence and domain-specific knowledge fully accounted for the ability to comprehend texts and videos. We conclude that neither test medium (paper-pencil versus handheld device) nor test modality (reading versus viewing) are decisive for comprehension ability in the natural sciences. Fluid intelligence and, even more strongly, domain-specific knowledge turned out to be exhaustive predictors of comprehension performance.
Factorial Structure of the SCAS and Its Relationship With the SDQ
Authors: Di Riso Daniela , Chessa Daphne , Bobbio Andrea , Lis Adriana
Published: March 2012

The factorial structure of the Spence Children’s Anxiety Scale (SCAS; Spence, 1997 ) was examined in a community sample of 1,397 Italian children from 8 to 10 years old. Sex and age differences as regards anxiety symptoms were also analyzed. The convergent validity of the SCAS was explored through correlations with the Strengths and Difficulties Questionnaire (SDQ; Goodman, 1997 ). The use of confirmatory factor analysis supported the six correlated factor model of the SCAS with only minor differences compared to the original work by Spence (1997 ), and it was therefore named SCAS-it. Modifications to the original SCAS were supported by methodologically, theoretically, and culturally based arguments. The internal consistency of the SCAS-it was acceptable. Females displayed significantly higher levels of anxiety symptoms than males, while age differences were nonsignificant. Positive correlations were found between the SCAS-it and selected subscales of the SDQ. The results support the SCAS model, with few exceptions that do not threaten the utility of Spence’s tool.
Validity and Reliability of the Chinese Translation of Basic Psychological Needs in Exercise Scale
Authors: Liu Jing Dong , Chung Pak Kwong , Duan Yanping
Published: March 2012

The current study examined some psychometric properties of the Basic Psychological Needs in Exercise Scale (BPNES; Vlachopoulos & Michailidou, 2006 ) in a group of Chinese university students in Hong Kong. A total of 460 undergraduate students were invited to take part in this study. We examined the factorial validity, discriminant validity, nomological validity, internal reliability, and measurement invariance across sex of a Chinese translation of the BPNES. The findings demonstrated that the scale had a good factorial validity and satisfactory internal reliability. Measurement invariance analysis indicated that the factor loadings and factor variance as well as covariance of measurement structure were invariant across male and female participants. Nomological validity was supported by the results of SEM analysis. Overall, the current study provided initial evidence for the validity and reliability of a Chinese translation of BPNES, and suggested that this scale could be used to measure satisfaction of psychological needs in the exercise field of Hong Kong undergraduate students.
Psychometric Properties of the Hebrew Version of the Utrecht Work Engagement Scale (UWES-9)
Authors: Littman-Ovadia Hadassah , Balducci Cristian
Published: March 2012

Work engagement may be defined as a positive and fulfilling psychological state associated with both affective response and mental arousal. This study investigated the psychometric properties of the Hebrew version of the Utrecht Work Engagement Scale (UWES-9) by using a sample of Israeli (N = 252) white-collar employees. We conducted a series of confirmatory factor analyses of the UWES-9 in addition to the customary reliability analyses and found that a three-factor solution of the UWES-9 best fit the data and confirmed the dimensions of vigor, dedication, and absorption associated with work engagement. The reliability coefficients of consistency were high. The validity of the UWES-9 was confirmed by its correlations with Job-Intrinsic and Job-Extrinsic Satisfaction (MSQ-SF; Minnesota Satisfaction Questionnaire Short Form). The Hebrew version of the UWES-9 administered to Israelis shares the same psychometric properties reported for the original Dutch version and suggests a transnational, translinguistic, and transcultural validity.
Substorm‐like magnetospheric response to a discontinuity in the Bx component of interplanetary magnetic field
Authors: Nowada M. , Lin C.‐H. , Pu Z.‐Y. , Fu S.‐Y. , Angelopoulos V. , Carlson C. W. , Auster H.‐U.
Published: March 2012

We examined the magnetospheric magnetic field and plasma responses to an encounter of a discontinuity in the Bx component of interplanetary magnetic field (IMF). The striking variations of simultaneous solar wind dynamic pressure and IMF‐Bz were not observed. Furthermore, we found that this IMF‐Bx discontinuity was a heliospheric current sheet, separating two high‐speed solar wind streams with different velocity and magnetic polarity. In this study, the magnetic field and plasma data were obtained from Time History of Events and Macroscale Interactions during Substorms (THEMIS), Cluster, and GOES to investigate the magnetospheric responses, and those were taken from ACE and Geotail to monitor the solar wind conditions. Simultaneous geomagnetic field variations from the ground observatories and aurora activity from Polar were also examined. When the discontinuity encountered the magnetosphere, THEMIS‐D, ‐E, and THEMIS‐A observed abrupt and transient magnetic field and plasma variations in the dawnside near‐Earth magnetotail and tail‐flank magnetopause. Significant magnetic field perturbations were not observed by Cluster as located in the duskside magnetotail at this time interval. Although simultaneous dipolarization and negative bay variations with Pi2 waves were observed by GOES and the ground observatories, global auroral activities were not found. Around the dawnside tail‐flank magnetopause, THEMIS‐C and ‐A experienced the magnetopause crossings due to the magnetopause surface waves induced by Kelvin‐Helmholtz instability. These results suggest that the magnetic field and plasma variations in the near‐Earth magnetotail and tail‐flank magnetopause were caused by moderate substorm‐like phenomena and magnetopause surface waves. They also indicate that clear magnetospheric disturbances can be brought even without significant variations in the solar wind.
Imaging mesoscale upper ocean dynamics using synthetic aperture radar and optical data
Authors: Kudryavtsev Vladimir , Myasoedov Alexander , Chapron Bertrand , Johannessen Johnny A. , Collard Fabrice
Published: March 2012

A synergetic approach for quantitative analysis of high‐resolution ocean synthetic aperture radar (SAR) and imaging spectrometer data, including the infrared (IR) channels, is suggested. This approach first clearly demonstrates that sea surface roughness anomalies derived from Sun glitter imagery compare very well to SAR roughness anomalies. As further revealed using these fine‐resolution (∼1 km) observations, the derived roughness anomaly fields are spatially correlated with sharp gradients of the sea surface temperature (SST) field. To quantitatively interpret SAR and optical (in visible and IR ranges) images, equations are derived to relate the “surface roughness” signatures to the upper ocean flow characteristics. As developed, a direct link between surface observations and divergence of the sea surface current field is anticipated. From these satellite observations, intense cross‐frontal dynamics and vertical motions are then found to occur near sharp horizontal gradients of the SST field. As a plausible mechanism, it is suggested that interactions of the wind‐driven upper layer with the quasi‐geostrophic current field (via Ekman advective and mixing mechanisms) result in the generation of secondary ageostrophic circulation, producing convergence and divergence of the surface currents. The proposed synergetic approach combining SST, Sun glitter brightness, and radar backscatter anomalies, possibly augmented by other satellite data (e.g., altimetry, scatterometry, ocean color), can thus provide consistent and quantitative determination of the location and intensity of the surface current convergence/divergence (upwelling/downwelling). This, in turn, establishes an important step toward advances in the quantitative interpretation of the upper ocean dynamics from their two‐dimensional satellite surface expressions.
Evaluation of momentum and sensible heat fluxes in constant density coordinates: Application to superpressure balloon data during the VORCORE campaign
Authors: Walterscheid R. L. , Gelinas L. J. , Mechoso C. R. , Schubert G.
Published: March 2012

Expressions for momentum and heat fluxes using density as the vertical coordinate are derived. These are applied in the evaluation of fluxes using data from super‐pressure balloons drifting on constant density surfaces in the Antarctic lower stratosphere during the VORCORE campaign (September 2005 to February 2006). We focus on the core months of October and November. Vertical fluxes of zonal and meridional momentum are calculated using wind, pressure and height data and the vertical flux of sensible heat is calculated using temperature and height data. Calculations were performed in three band passes covering 1–13 h. We find that the largest fluxes are in the vicinity of the Antarctic Peninsula. In October the fluxes in the low period band pass (1–5 h) account for the main part of the total flux of zonal momentum, consistent with topographically forced waves. During November the vertical fluxes of zonal momentum are found mainly in longer period band passes, consistent with weaker winds. The peak campaign‐averaged flux of zonal momentum in the vicinity of the Antarctic Peninsula is ∼−30 mPa. These values are ∼60% larger over the peninsula than those inferred by other authors. The flux of zonal momentum provides a zonal body force of ∼5 m s−1 day−1 assuming a saturated spectrum. We infer downward sensible heat fluxes of ∼3 W m−2. The corresponding cooling rates assuming a saturated spectrum are ∼0.6 K day−1, a significant fraction of the net radiative imbalance in the springtime Antarctic lower stratosphere.
Influence of changes in observations on precipitation: A case study for the Climate Forecast System Reanalysis (CFSR)
Authors: Zhang Li , Kumar Arun , Wang Wanqiu
Published: March 2012

Reanalysis products often show discontinuities in the time evolution of analyzed fields, particularly for the derived variables, for example, precipitation. In the recently completed Climate Forecast System Reanalysis (CFSR) at the National Centers for Environmental Prediction, a sharp increase in the global mean precipitation around 1998 has been noted. A similar abrupt change also appears in several other reanalyses that have been recently completed. This sharp increase coincides with the introduction of the Advanced TIROS Operational Vertical Sounder (ATOVS) data into the assimilation system. Based on model simulations to complement the CFSR, this study analyzes the reason behind the sudden jump in precipitation. The outputs from both the CFSR and a simulation with the CFSR's atmospheric component model forced with the observed sea surface temperature and carbon dioxide concentration are used to understand the precipitation abrupt change in the CFSR. The analysis indicates that the change results from (1) the tendency of the forecast (during the assimilation cycle) to drift toward its mean state that is cooler and drier, (2) the tendency of the assimilation to correct the first guess forecast to a wetter analysis, (3) an analysis that the period after 1998 is in an even wetter mean state due to the ingestion of the ATOVS data, and (4) the combination of previous three factors resulting in a abrupt change in precipitation during the assimilation around 1998. The results presented here may also provide the developers of the reanalysis systems further insights about the possible causes for the change in precipitation around 1998.
Density variations within the south polar layered deposits of Mars
Authors: Li Junlun , Andrews‐Hanna Jeffrey C. , Sun Youshun , Phillips Roger J. , Plaut Jeffrey J. , Zuber Maria T.
Published: March 2012

The south polar layered deposits (SPLD) constitute the largest known reservoir of water on Mars. Previous studies solved for the best fit uniform density of the deposits using a forward approach. Here we invert for the lateral density variations in the layered deposit using gravity data from radio tracking of Mars Reconnaissance Orbiter, topography from MOLA on board Mars Global Surveyor, and radar sounding data from MARSIS on board Mars Express. We use the gravity anomalies outside the SPLD to construct a Wiener filter, which is applied to the gravitational signature of the SPLD to remove the short‐wavelength anomalies over the SPLD that are spectrally consistent with an origin in the crust or mantle. We then use a constrained inversion for the vertically averaged density within the SPLD as a function of position. The results suggest significant density variations within the SPLD. An inverse relationship between the density and thickness of the SPLD suggests that thicker portions of the cap contain less dust. Alternatively, the Dorsa Argentea Formation may extend beneath the SPLD and result in the observed high gravity anomaly in the marginal area of the SPLD. We find these conclusions to be robust against the choice of inversion constraint and perturbations to the applied filter. A synthetic test is also performed to verify the recoverability of the density variation in our approach.
Spacecraft charging near Enceladus
Authors: Hsu H.‐W. , Horányi M. , Kempf S. , Grün E.
Published: March 2012

In the vicinity of Enceladus, a geologically active moon of Saturn, the modeled spacecraft potential is significantly more negative than indicated by the Cassini Langmuir probe measurements. To understand this potential difference, we introduce two new dust–related charging currents: a) the dust ram current; and b) the dust impact–plasma current, in addition to the customary collection of electrons and ions, and photoemission. Our results show that these dust currents are important at high relative speeds between the spacecraft and the dust, or in regions with a low plasma‐to‐dust ratio, and can lead to reduced spacecraft charging.
Direct measurement of volume flux in the Faroe‐Shetland Channel and over the Iceland‐Faroe Ridge
Authors: Rossby T. , Flagg C. N.
Published: March 2012

Determining the exchange of water across the Iceland‐Faroe‐Scotland ridge is of fundamental interest because it measures the rate of transformation of North Atlantic water into dense water and thus the strength of the meridional overturning circulation (MOC). Here we study this exchange by monitoring all water flowing through the area east of Iceland to near the bottom or ∼600 m depth using a 75 kHz acoustic Doppler current profiler (ADCP) mounted on the high‐seas ferry M/F Norröna. Starting in March 2008, currents have been measured in the Faroe‐Shetland Channel (FSC) and along the Iceland‐Faroe Ridge (IFR) on the ferry's weekly round‐trips between Iceland and Denmark. The detided average transports (to the north) across the two sections are 4.1 ± 0.1 Sv (106 m2s−1) through the FSC and 4.4 ± 0.25 Sv across the IFR (this excludes ∼1.6 Sv circulating around the Faroes). The Norröna program is ongoing.
Ecological niche models reveal the importance of climate variability for the biogeography of protosteloid amoebae
Authors: Aguilar María , Lado Carlos
Published: March 2012

Habitat availability and environmental preferences of species are among the most important factors in determining the success of dispersal processes and therefore in shaping the distribution of protists. We explored the differences in fundamental niches and potential distributions of an ecological guild of slime moulds—protosteloid amoebae—in the Iberian Peninsula. A large set of samples collected in a north-east to south-west transect of approximately 1000 km along the peninsula was used to test the hypothesis that, together with the existence of suitable microhabitats, climate conditions may determine the probability of survival of species. Although protosteloid amoebae share similar morphologies and life history strategies, canonical correspondence analyses showed that they have varied ecological optima, and that climate conditions have an important effect in niche differentiation. Maxent environmental niche models provided consistent predictions of the probability of presence of the species based on climate data, and they were used to generate maps of potential distribution in an ‘everything is everywhere’ scenario. The most important climatic factors were, in both analyses, variables that measure changes in conditions throughout the year, confirming that the alternation of fruiting bodies, cysts and amoeboid stages in the life cycles of protosteloid amoebae constitutes an advantage for surviving in a changing environment. Microhabitat affinity seems to be influenced by climatic conditions, which suggests that the micro-environment may vary at a local scale and change together with the external climate at a larger scale.
Molecular evidence of iron limitation and availability in the global diazotroph Trichodesmium
Authors: Chappell Phoebe Dreux , Moffett James W , Hynes Annette M , Webb Eric A
Published: March 2012

The activity of the N2-fixing cyanobacterial genus Trichodesmium is critical to the global nitrogen (N) and carbon (C) cycles. Although iron (Fe) has been shown to be an important element limiting the growth and N2 fixation of Trichodesmium, there have been no specific data demonstrating the in situ affect of Fe on Trichodesmium. We surveyed Trichodesmium populations from the Atlantic and Pacific Oceans for Fe limitation using a novel quantitative reverse transcriptase-PCR (qRT-PCR) method monitoring the expression of an Fe limitation-induced gene, isiB. Here we report the first molecular evidence of in situ Fe limitation of Trichodesmium N2 fixation, which was evident in samples from the Pacific Ocean, whereas limitation appeared minimal to nonexistent in Atlantic Ocean samples. As our method is Trichodesmium clade specific, we were also able to determine that representatives from the Trichodesmium tenue clade were the most biologically active group of Trichodesmium in the majority of our samples, which speaks to their dominance in open ocean regimes. Furthermore, comparisons of our field expression and chemical data with laboratory studies suggest that the majority of dissolved Fe in the open ocean is available to Trichodesmium colonies regardless of Fe complexation.
Archaea in metazoan diets: implications for food webs and biogeochemical cycling
Authors: Thurber Andrew R , Levin Lisa A , Orphan Victoria J , Marlow Jeffrey J
Published: March 2012

Although the importance of trophic linkages, including ‘top-down forcing’, on energy flow and ecosystem productivity is recognized, the influence of metazoan grazing on Archaea and the biogeochemical processes that they mediate is unknown. Here, we test if: (1) Archaea provide a food source sufficient to allow metazoan fauna to complete their life cycle; (2) neutral lipid biomarkers (including crocetane) can be used to identify Archaea consumers; and (3) archaeal aggregates are a dietary source for methane seep metazoans. In the laboratory, we demonstrated that a dorvilleid polychaete, Ophryotrocha labronica, can complete its life cycle on two strains of Euryarchaeota with the same growth rate as when fed bacterial and eukaryotic food. Archaea were therefore confirmed as a digestible and nutritious food source sufficient to sustain metazoan populations. Both strains of Euryarchaeota used as food sources had unique lipids that were not incorporated into O. labronica tissues. At methane seeps, sulfate-reducing bacteria that form aggregations and live syntrophically with anaerobic-methane oxidizing Archaea contain isotopically and structurally unique fatty acids (FAs). These biomarkers were incorporated into tissues of an endolithofaunal dorvilleid polychaete species from Costa Rica (mean bulk δ13C=−92±4‰; polar lipids −116‰) documenting consumption of archaeal-bacterial aggregates. FA composition of additional soft-sediment methane seep species from Oregon and California provided evidence that consumption of archaeal-bacterial aggregates is widespread at methane seeps. This work is the first to show that Archaea are consumed by heterotrophic metazoans, a trophic process we coin as ‘archivory’.
Serial Childhood BMI and Associations With Adult Hypertension and Obesity: The Fels Longitudinal Study
Authors: Sabo Roy T. , Lu Zheng , Daniels Steven , Sun Shumei S.
Published: March 2012

Previous studies estimated critical periods of childhood BMI growth and linked these events to adult adiposity and cardiovascular health. We expand upon both results to link childhood BMI growth patterns with adult blood pressure (BP). Data from male and female participants in the Fels Longitudinal Study (FLS) were used to estimate childhood BMI growth curves, from which we isolate ages of childhood BMI divergence based upon adult BMI and BP measurements. Repeated measure analysis of variances models were used to estimate BMI growth curves from age 2 to age 17.5 based on both adult BMI (< 25 kg/m2 or ≥ 25 kg/m2) and adult BP (< 120 mm Hg or ≥ 120 mm Hg for systolic BP (SBP); < 80 mm Hg or ≥ 80 mm Hg for diastolic BP (DBP)). Participants with lower body weight throughout childhood had lower SBP and DBP in early adulthood. Any relationships between childhood adiposity and adult body weight and BP disappeared by age 60. These results were independent of adult BMI and were observed in both men and women. Increased adult BP has its genesis in part from increased childhood BMI.
Relationship Between Sleep Quality and Quantity and Weight Loss in Women Participating in a Weight‐Loss Intervention Trial
Authors: Thomson Cynthia A. , Morrow Kelly L. , Flatt Shirley W. , Wertheim Betsy C. , Perfect Michelle M. , Ravia Jennifer J. , Sherwood Nancy E. , Karanja Njeri , Rock Cheryl L.
Published: March 2012

Evidence suggests that individuals who report fewer total hours of sleep are more likely to be overweight or obese. Few studies have prospectively evaluated weight‐loss success in relation to reported sleep quality and quantity. This analysis sought to determine the association between sleep characteristics and weight loss in overweight or obese women enrolled in a randomized clinical trial of a weight‐loss program. We hypothesized that in overweight/obese women, significant weight loss would be demonstrated more frequently in women who report a better Pittsburgh Sleep Quality Index (PSQI) Global Score or sleep >7 h/night as compared to women who report a worse PSQI score or sleep ≤7 h/night. Women of ages 45.5 ± 10.4 (mean ± SD) years and BMI of 33.9 ± 3.3 (n = 245) were randomized and completed PSQI at baseline and 6 months; 198 had weight change assessed through 24 months. At baseline, 52.7% reported PSQI scores above the clinical cutoff of 5. Better subjective sleep quality increased the likelihood of weight‐loss success by 33% (relative risk (RR), 0.67; 95% confidence interval (CI), 0.52–0.86), as did sleeping >7 h/night. A worse Global Score at 6 months was associated with a 28% lower likelihood of continued successful weight loss at 18 months, but unassociated by 24 months. These results suggest that sleep quality and quantity may contribute to weight loss in intervention‐based studies designed to promote weight control in overweight/obese adult women.
JNK- and Akt-mediated Puma expression in the apoptosis of cisplatin-resistant ovarian cancer cells
Authors: Zhao Zhiwei , Wang Jingjing , Tang Jingsheng , Liu Xinyu , Zhong Qian , Wang Fang , Hu Wenbin , Yuan Zhu , Nie Chunlai , Wei Yuquan
Published: March 2012

BH3 (Bcl-2 homology domain 3)-only proteins have an important role in the cisplatin resistance of cells. However, the effect of BH3-only proteins on cisplatin-resistant ovarian cancer cells has not been thoroughly elucidated. Our results from the present study indicate that Puma plays a critical role in the apoptosis of chemo-resistant ovarian cancer cells treated with BetA (betulinic acid). The reduction of Puma expression inhibits Bax activation and apoptosis. However, p53 gene silencing has little effect on Puma activation. Further experiments demonstrated that Akt-mediated FoxO3a (forkhead box O3a) nuclear translocation and the JNK (c-Jun N-terminal kinase)/c-Jun pathway only partially trigger Puma induction and apoptosis, whereas dominant-negative c-Jun expression with FoxO3a reduction completely inhibits Puma expression and cell death. Furthermore, our results suggest that JNK regulates the Akt/FoxO3a signalling pathway. Therefore the dual effect of JNK can efficiently trigger Puma activation and apoptosis in chemoresistant cells. Taken together, our results demonstrate the role of Puma in BetA-induced apoptosis and the molecular mechanisms of Puma expression regulated by BetA during ovarian cancer cell apoptosis. Our findings suggest that the JNK-potentiated Akt/FoxO3a and JNK-mediated c-Jun pathways co-operatively trigger Puma expression, which determines the threshold for overcoming chemoresistance in ovarian cancer cells.
Construction of histidine-tagged yeast mitochondrial cytochrome c oxidase for facile purification of mutant forms
Authors: Meunier Brigitte , Maréchal Amandine , Rich Peter R.
Published: March 2012

Yeast CcO (cytochrome c oxidase) has been developed as a facile system for the production and analysis of mutants of a mitochondrial form of CcO for mechanistic studies. First, a 6H tag (His6 tag) was fused to the C-terminus of a nuclear-encoded subunit of CcO from yeast Saccharomyces cerevisiae. This allowed efficient purification of a WT (wild-type) mitochondrial CcO, 6H-WT (yeast CcO with a 6H tag on the nuclear-encoded Cox13 subunit), with a recovery yield of 45%. Its catalytic-centre activity [≈180 e·s−1 (electrons per s)], UV–visible signatures of oxidized and reduced states and ability to form the PM [‘peroxy’ (but actually a ferryl/radical state)] and F (ferryl) intermediates confirm normal functioning of the histidine-tagged protein. Point mutations were introduced into subunit I of the 6H-WT strain. All mutants were screened for their ability to assemble CcO and grow on respiratory substrate. One such mutant [6H-E243DI (the 6H-WT strain with an additional mutation of E243D in mitochondrial DNA-encoded subunit I)] was purified and showed ~50% of the 6H-WT catalytic-centre activity, consistent with the effects of the equivalent mutation in bacterial oxidases. Mutations in both the D and the H channels affect respiratory growth and these effects are discussed in terms of their putative roles in CcO mechanism.
An activity-based probe reveals dynamic protein–protein interactions mediating IGF-1R transactivation by the GABAB receptor
Authors: Lin Xin , Li Xin , Jiang Ming , Chen Linhai , Xu Chanjuan , Zhang Wenhua , Zhao Han , Sun Bing , Xu Xiaoli , Nan Fajun , Liu Jianfeng
Published: March 2012

Many GPCRs (G-protein-coupled receptors) can activate RTKs (receptor tyrosine kinases) in the absence of RTK ligands, a phenomenon called transactivation. However, the underlying molecular mechanisms remain undefined. In the present study we investigate the molecular basis of GABAB (γ-aminobutyric acid B) receptor-mediated transactivation of IGF-1R (insulin-like growth factor type I receptor) in primary neurons. We take a chemical biology approach by developing an activity-based probe targeting the GABAB receptor. This probe enables us first to lock the GABAB receptor in an inactive state and then activate it with a positive allosteric modulator, thereby permitting monitoring of the dynamic of the protein complex associated with IGF-1R transactivation. We find that activation of the GABAB receptor induces a dynamic assembly and disassembly of a protein complex, including both receptors and their downstream effectors. FAK (focal adhesion kinase), a non-RTK, plays a key role in co-ordinating this dynamic process. Importantly, this dynamic of the GABAB receptor-associated complex is critical for transactivation and transactivation-dependent neuronal survival. The present study has identified an important mechanism underlying GPCR transactivation of RTKs, which was enabled by a new chemical biology tool generally applicable for dissecting GPCR signalling.
Urinary corticosteroid excretion predicts left ventricular mass and proteinuria in chronic kidney disease
Authors: McQuarrie Emily P. , Freel E. Marie , Mark Patrick B. , Fraser Robert , Patel Rajan K. , Dargie Henry G. , Connell John M. C. , Jardine Alan G.
Published: March 2012

Blockade of the MR (mineralocorticoid receptor) in CKD (chronic kidney disease) reduces LVMI [LV (left ventricular) mass index] and proteinuria. The MR can be activated by aldosterone, cortisol and DOC (deoxycorticosterone). The aim of the present study was to explore the influence of mineralocorticoids on LVMI and proteinuria in patients with CKD. A total of 70 patients with CKD and 30 patients with EH (essential hypertension) were recruited. Patients underwent clinical phenotyping; biochemical assessment and 24 h urinary collection for THAldo (tetrahydroaldosterone), THDOC (tetrahydrodeoxycorticosterone), cortisol metabolites (measured using GC–MS), and urinary electrolytes and protein [QP (proteinuira quantification)]. LVMI was measured using CMRI (cardiac magnetic resonance imaging). Factors that correlated significantly with LVMI and proteinuria were entered into linear regression models. In patients with CKD, significant predictors of LVMI were male gender, SBP (systolic blood pressure), QP, and THAldo and THDOC excretion. Significant independent predictors on multivariate analysis were THDOC excretion, SBP and male gender. In EH, no association was seen between THAldo or THDOC and LVMI; plasma aldosterone concentration was the only significant independent predictor. Significant univariate determinants of proteinuria in patients with CKD were THAldo, THDOC, USod (urinary sodium) and SBP. Only THAldo excretion and SBP were significant multivariate determinants. Using CMRI to determine LVMI we have demonstrated that THDOC is a novel independent predictor of LVMI in patients with CKD, differing from patients with EH. Twenty-four hour THAldo excretion is an independent determinant of proteinuria in patients with CKD. These findings emphasize the importance of MR activation in the pathogenesis of the adverse clinical phenotype in CKD.
Precessional spin-transfer switching in a magnetic tunnel junction with a synthetic antiferromagnetic perpendicular polarizer
Authors: Marins de Castro M. , Sousa R. C. , Bandiera S. , Ducruet C. , Chavent A. , Auffret S. , Papusoi C. , Prejbeanu I. L. , Portemont C. , Vila L. , Ebels U. , Rodmacq B. , Dieny B.
Published: March 2012

This paper reports sub-nanosecond precessional spin-transfer switching in elliptical magnetic tunnel junction nanopillars. This result is obtained in samples integrating a synthetic antiferromagnetic perpendicular polarizer and a tunnel junction with in-plane magnetized electrodes. The out-of-plane precession of the free layer magnetization results in oscillations of the switching probability as a function of the pulse width. At 9.25 MA/cm2 current density, these oscillations have a period of 1 ns with a high degree of coherence.