bluuebunny/crossref_metadata_2025_split huggingface dataset:
Properties and origin of subproton‐scale magnetic holes in the terrestrial plasma sheet
Authors: Sundberg T. , Burgess D. , Haynes C. T. 
Published: March 2015

AbstractElectron‐scale magnetic depressions in the terrestrial plasma sheet are studied using Cluster multispacecraft data. The structures, which have an observed duration of ~5–10 s, are approximately 200–300 km wide in the direction of propagation, and they show an average reduction in the background magnetic field of 10–20%. A majority of the events are also associated with an increase in the high‐energy high pitch angle electron flux, which indicates that the depressions are presumably generated by electrons with relatively high velocity perpendicular to the background magnetic field. Differences in the recorded electron spectra in the four spacecraft indicates a possible nongyrotropic structure. Multispacecraft measurements show that a subset of events are cylindrical, elongated along the magnetic field, and with a field‐parallel scale size of at a minimum 500 km. Other events seem to be better described as electron‐scale sheets, about 200–300 km thick. We find that no single formation mechanism can explain this variety of events observed. Instead, several processes may be operating in the plasma sheet, giving rise to similar magnetic field structures in the single‐spacecraft data, but with different 3‐D structuring. The cylindrical structures have several traits that are in agreement with the electron vortex magnetic holes observed in 2‐D particle‐in‐cell simulations of turbulent relaxation, whereas the sheets, which show nearly identical signatures in the multispacecraft data, are better explained by propagating electron solitary waves.
Crystallization and immersion freezing ability of oxalic and succinic acid in multicomponent aqueous organic aerosol particles
Authors: Wagner Robert , Höhler Kristina , Möhler Ottmar , Saathoff Harald , Schnaiter Martin 
Published: March 2015

AbstractThis study reports on heterogeneous ice nucleation efficiency of immersed oxalic and succinic acid crystals in the temperature range from 245 to 215 K, as investigated with expansion cooling experiments using suspended particles. In contrast to previous laboratory work with emulsified solution droplets where the precipitation of solid inclusions required a preceding freezing/evaporation cycle, we show that immersed solids readily form by homogeneous crystallization within aqueous solution droplets of multicomponent organic mixtures, which have noneutonic compositions with an excess of oxalic or succinic acid. Whereas succinic acid crystals did not act as heterogeneous ice nuclei, immersion freezing by oxalic acid dihydrate crystals led to a reduction of the ice saturation ratio at freezing onset by 0.066–0.072 compared to homogeneous freezing, which is by a factor of 2 higher than previously reported laboratory data. These observations emphasize the importance of oxalic acid in heterogeneous ice nucleation.
Contributions of atmospheric circulation variability and data coverage bias to the warming hiatus
Authors: Saffioti Claudio , Fischer Erich M. , Knutti Reto 
Published: March 2015

AbstractThe warming hiatus shows a strong seasonal and geographical asymmetry, with cooling in the Northern Hemisphere winter, especially over land, and warming elsewhere and in the other seasons. We show that the characteristics of the Northern Hemisphere winter cooling in 1998–2012 can mostly be explained by missing observations and by internal variability in the atmospheric circulation of the Northern Hemisphere extratropics. Estimates of the annual and seasonal temperature trends in 1998–2012 obtained by considering the concurrent effects of unforced natural variability and of coverage bias are much closer to the corresponding long‐term trends. Reanalyses suggest that the coverage bias was exceptionally pronounced during recent years and that an area of strong warming was missed due to the incomplete observational coverage. Coupled Model Intercomparison Project Phase 5 climate models indicate that trends in atmospheric circulation during the hiatus period did not occur as a response to anthropogenic forcing.
Dynamical processes within an anticyclonic eddy revealed from Argo floats
Authors: Zhang Wen‐Zhou , Xue Huijie , Chai Fei , Ni Qinbiao 
Published: March 2015

AbstractMesoscale eddies play a significant role in supplying the nutrients required for phytoplankton blooms and redistributing biomass in the ocean. However, how eddies influence nutrient flux and biomass distribution remains unclear. Here we reveal two important dynamical processes (radial displacement and vertical fluctuations) within an anticyclonic eddy by analyzing observations from Argo floats. The Argo floats in the eddy were displaced toward the eddy edge due to the imbalance of radial momentum. Vertical fluctuations below the mixed layer resulted in alternating upwelling and downwelling in the inner and outer parts of the eddy. High salinity deep water was uplifted tens of meters by the upwelling and further extended to the surface with the aid of wind effects. Vertical motions associated with the fluctuations penetrated to the depths of several hundred meters. These processes represent crucial dynamical mechanisms for the motion of particles in mature anticyclonic eddies.
Magmatism on rift flanks: Insights from ambient noise phase velocity in Afar region
Authors: Korostelev Félicie , Weemstra Cornelis , Leroy Sylvie , Boschi Lapo , Keir Derek , Ren Yong , Molinari Irene , Ahmed Abdulhakim , Stuart Graham W. , Rolandone Frédérique , Khanbari Khaled , Hammond James O. S. , Kendall J. M. , Doubre Cécile , Ganad Ismail Al , Goitom Berhe , Ayele Atalay 
Published: March 2015

AbstractDuring the breakup of continents in magmatic settings, the extension of the rift valley is commonly assumed to initially occur by border faulting and progressively migrate in space and time toward the spreading axis. Magmatic processes near the rift flanks are commonly ignored. We present phase velocity maps of the crust and uppermost mantle of the conjugate margins of the southern Red Sea (Afar and Yemen) using ambient noise tomography to constrain crustal modification during breakup. Our images show that the low seismic velocities characterize not only the upper crust beneath the axial volcanic systems but also both upper and lower crust beneath the rift flanks where ongoing volcanism and hydrothermal activity occur at the surface. Magmatic modification of the crust beneath rift flanks likely occurs for a protracted period of time during the breakup process and may persist through to early seafloor spreading.
A traceable physical calibration of the vertical advection‐diffusion equation for modeling ocean heat uptake
Authors: Huber Markus , Tailleux Remi , Ferreira David , Kuhlbrodt Till , Gregory Jonathan 
Published: March 2015

AbstractThe classic vertical advection‐diffusion (VAD) balance is a central concept in studying the ocean heat budget, in particular in simple climate models (SCMs). Here we present a new framework to calibrate the parameters of the VAD equation to the vertical ocean heat balance of two fully‐coupled climate models that is traceable to the models' circulation as well as to vertical mixing and diffusion processes. Based on temperature diagnostics, we derive an effective vertical velocity w∗ and turbulent diffusivity for each individual physical process. In steady state, we find that the residual vertical velocity and diffusivity change sign in middepth, highlighting the different regional contributions of isopycnal and diapycnal diffusion in balancing the models' residual advection and vertical mixing. We quantify the impacts of the time evolution of the effective quantities under a transient 1% CO2 simulation and make the link to the parameters of currently employed SCMs.
A simple framework for assessing the sensitivity of mountain watersheds to warming‐driven snowpack loss
Authors: Tennant Christopher J. , Crosby Benjamin T. , Godsey Sarah E. , VanKirk Robert W. , Derryberry DeWayne R. 
Published: March 2015

AbstractThe common observation that snowpack increases with elevation suggests that a catchment's elevation distribution should be a robust indicator of its potential to store snow and its sensitivity to snowpack loss. To capture a wide range of potential elevation‐based responses, we used Monte Carlo methods to simulate 20,000 watershed elevation distributions. We applied a simple function relating warming, elevation, and snowpack to explore snowpack losses from the simulated elevation distributions. Regression analyses demonstrate that snowpack loss is best described by three parameters that identify the central tendency, variance, and shape of each catchment's elevation distribution. Equal amounts of snowpack loss can occur even when catchments are centered within different elevation zones; this stresses the value of also measuring the variance and shape of elevation distributions. Responses of the simulated elevation distributions to warming are nonlinear and emphasize that the sensitivity of mountain forests to snowpack loss will likely be watershed dependent.
Developmental origins of flatter cortisol rhythms: socioeconomic status and adult cortisol activity
Authors: Desantis Amy S. , Kuzawa Christopher W. , Adam Emma K. 
Published: March 2015

ABSTRACTObjectiveLow socioeconomic status (SES) is associated with increased psychosocial stress among low‐income persons, which could contribute to differences in activity of the HPA axis (assessed by diurnal cortisol profiles). The current article investigates associations of SES from different developmental stages with cortisol profiles.MethodsUsing data from a large, socioeconomically diverse birth cohort (N = 1,490) in Cebu, Philippines, the current study compares the relative and joint contributions of SES from five developmental periods, between the prenatal/birth period and early adulthood, to adult cortisol, and examines the effects of chronic exposure to low SES.ResultsChronically low SES from infancy through early adulthood predicts the highest bedtime cortisol levels, lowest cortisol awakening responses (CARs), lowest total cortisol levels across the day (area under curve or AUC), and the flattest cortisol rhythms between wake up and bedtime, a profile associated with poorer health. Results indicate that cumulative economic strain (between the prenatal period and early adulthood) predicts flatter cortisol rhythms more consistently than SES from any particular period.ConclusionInterventions focusing on the psychosocial stressors associated with economic deprivation during any period from infancy to adulthood may be helpful, but targeting interventions across multiple periods may have the greatest impact. Interventions aimed at improving economic conditions between infancy and early adulthood may have implications for long‐term changes in HPA axis functioning. Am. J. Hum. Biol. 27:458–467, 2015. © 2015 Wiley Periodicals, Inc.
Women who are married or living as married have higher salivary estradiol and progesterone than unmarried women
Authors: Barrett Emily S. , Tran Van , Thurston Sally W. , Frydenberg Hanne , Lipson Susan F. , Thune Inger , Ellison Peter T. 
Published: March 2015

ObjectivesExtensive research has demonstrated that marriage and parenting are associated with lower testosterone levels in men, however, very little is known about associations with hormone concentrations in women. Two studies have found lower testosterone in relation to pair‐bonding and motherhood in women, with several others suggesting that estradiol levels are lower among parous women than nulliparous women. Here, we examine estradiol and progesterone concentrations in relation to marriage and motherhood in naturally cycling, reproductive age women.MethodsIn 185 Norwegian women, estradiol and progesterone concentrations were assayed from waking saliva samples collected daily over the course of a menstrual cycle. Cycles were aligned on day 0, the day of ovulation. Mean periovulatory estradiol (days −7 to +6) and luteal progesterone (day +2 to +10) indices were calculated. Marital status and motherhood (including age of youngest child) were reported in baseline questionnaires. Multivariable linear regression models were used to examine associations between ovarian hormones, marital status, and motherhood.ResultsWomen who were married or living as married had higher estradiol than unmarried women (β = 0.19; 95% CI: 0.02, 0.36) and higher luteal progesterone as well (β = 0.19; 95% CI: −0.01, 0.39). There were no notable differences in hormone levels in relationship to motherhood status.ConclusionsOur results indicate that ovarian steroid hormones may be higher among women who are married or living as married, and suggest several possible explanations, however, additional research is needed to elucidate any causal relationships. Am. J. Hum. Biol. 27:501–507, 2015. © 2015 Wiley Periodicals, Inc.
The effects of sports participation on the development of left ventricular mass in adolescent boys
Authors: Valente‐Dos‐Santos João , Coelho‐E‐Silva Manuel J. , Castanheira Joaquim , Machado‐Rodrigues Aristides M. , Cyrino Edilson S. , Sherar Lauren B. , Esliger Dale W. , Elferink‐Gemser Marije T. , Malina Robert M. 
Published: March 2015

ObjectivesTo examine the contribution of body size, biological maturation, and nonelite sports participation to longitudinal changes of left ventricular mass (LVM) in healthy boys.MethodsOne hundred and ten boys (11.0–14.5 years at baseline) were assessed biannually for 2 years. Stature, body mass, and four skinfolds were measured. Lean body mass (LBM) was estimated. Biological maturation was assessed as years from age at peak height velocity (APHV). Sports participation was assessed by questionnaire. LVM was obtained from M‐mode echocardiograms using two‐dimensional images. To account for the repeated measures within individual nature of longitudinal data, multilevel random effects regression analyses were used in the analysis.ResultsLVM increased on average 42 ± 18 g from 11 to 15 years (P < 0.05) and 76 ± 14 g from 3.5 years pre‐APHV to 1.5 years post‐APHV (P < 0.05). The multilevel model with the best statistical fit (Model B) showed that changes of 1 cm in stature, 1 year post‐APHV, and 1 kg of LBM predicts 4.7, 0.5, and 1 g of LVM (P < 0.05), respectively.ConclusionsAmong healthy, male adolescents aged 11–15 years individual differences in growth and biological maturation influence growth of LVM. Subcutaneous adiposity and sports participation were not associated with greater LVM. Am. J. Hum. Biol. 27:530–537, 2015. © 2015 Wiley Periodicals, Inc.
Perceived discrimination and markers of cardiovascular risk among low‐income African American youth
Authors: Goosby Bridget J. , Malone Sarah , Richardson Elizabeth A. , Cheadle Jacob E. , Williams Deadric T. 
Published: March 2015

ObjectivesOur study examines the relationship between perceived discrimination and levels of C‐reactive protein and blood pressure in low‐income youth ages 10−15 years old.MethodsData were collected from 10 to 15 year old focal children and their mothers. Face‐to‐face interviews were implemented to collect data on stressors including experiences of everyday discrimination from youth. High sensitivity CRP in dried blood spot samples and diastolic and systolic blood pressure were also collected at the time of the interview.ResultsPerceived discrimination among youth was significantly associated with higher levels of CRP, systolic, and diastolic blood pressure. CRP, systolic, and diastolic blood pressure remained significant after controlling for age‐adjusted BMI, waist circumference, and other factors.ConclusionsDiscrimination is a salient risk factor for inflammation and cardiovascular health. Early life course inflammation and cardiovascular reactivity are important candidate pathways through which the repeated exposure to discrimination for minority group members contributes to racial and economic health inequities in adulthood. Am. J. Hum. Biol. 27:546–552, 2015. © 2015 Wiley Periodicals, Inc.
Birth weight and the risk of overweight in young men born at term
Authors: Eriksen Willy , Sundet Jon Martin , Tambs Kristian 
Published: March 2015

ObjectiveThe aim of this birth cohort study was to determine the relationship between birth weight and the risk of overweight in young adulthood. Methods: Data from the Medical Birth Registry of Norway were linked with register data from the National Conscript Service. This study used data on the 348,800 males who were born at term in single births in Norway during 1967 to 1984, and who were examined at the mandatory military conscription (98% were examined the year they turned 18 or 19 years of age). Sibling comparisons were conducted in the 11,865 sibships of two or more full brothers in which at least one brother was overweight (body mass index ≥25.0 kg/m2) and at least one brother was not overweight. Results: When all the men in the study population were compared with each other there was a “J”‐shaped association between birth weight and the adjusted odds of overweight. When the men were compared with their brothers, the adjusted odds of overweight increased in an exponential way (linearly in logit) over the entire range of the birth weight scale. A within‐family difference of 100 g in birth weight was associated with a within‐family difference of 3.5% (99% confidence interval: 2.5–4.6) in the odds of overweight. Conclusions: There is a positive within‐family association between birth weight and the odds of overweight in young Norwegian men born at term. Am. J. Hum. Biol. 27:564–569, 2015. © 2015 Wiley Periodicals, Inc.
5′ and 3′ β‐globin haplotypes in purepechas and Tarahumaras, two Mexican indigenous groups
Authors: Casas‐castañeda M. , Ibarra B. , Rizo‐De La Torre L.C. , Sánchez‐López J.Y. , Magaña‐Torres M.T. 
Published: March 2015

ObjectiveThe purpose of this study was to determine the β‐globin cluster haplotype variability of two Mexican indigenous groups—Purepechas (PUR) and Tarahumaras (TAR)—and their relationship with other world populations.MethodsThe 5′ and 3′ haplotypes (Hp) of the β globin cluster in 71 PUR and 53 TAR individuals were analyzed. Five polymorphisms in the 5′Hp (ε, Gγ, Aγ, 5′ψβ and 3′ψβ) and five in the 3′Hp (IVS2: 16, 46, 74, 81 and 3′ end +339) were identified by restriction enzymes and direct DNA sequencing. 5′Hp and 3′Hp frequencies in PUR and TAR were compared with reported frequencies from 47 and 10 worldwide populations, respectively.ResultsSixteen different 5′Hps were observed in the indigenous Mexican groups, 11 in each population, with the most common being 5′Hp 1. Eight 3′Hps were detected, seven in PUR and six in TAR, the most frequent being 3′Hp C. Three new 3′Hps were found, A8 (CTGCT) in both populations, C9 (GTGCA) in TAR and E1 (GTTCT) in PUR. The comparative analysis showed that 5′Hp frequencies in PUR were significantly different than those in all populations except the Brazilian‐Guarani, while TAR were significantly similar to Aché and North Han Chinese. 3′Hp frequencies were similar between PUR and TAR, as well as with Nuu‐Chah‐Nulth, Mongolian and Sumatran populations.ConclusionsThe 5′Hp analysis showed great variability in worldwide populations, including PUR and TAR, while 3′Hp frequencies were similar among indigenous Mexican and other populations with Asiatic origins. This suggests that 5′Hp exposes the microevolutionary process of each population and the 3′Hp establishes genetic relationships among populations. Am. J. Hum. Biol. 27:697–703, 2015. © 2015 Wiley Periodicals, Inc.
Secular trends in body height and body mass in 19‐year‐old polish men based on six national surveys from 1965 to 2010
Authors: Kołodziej Halina , łopuszańska Monika , Lipowicz Anna , Szklarska Alicja , Bielicki Tadeusz 
Published: March 2015

ObjectivesThe aim was to determine whether an intergenerational trend toward increased stature is slowing down, and whether body weight has recently increased among young men in Poland, as it has in Western European countries.MethodsData were taken from six national surveys of 19‐year‐old Polish male conscripts from cohorts 1965, 1976, 1986, 1995, 2001, and 2010.ResultsThe mean stature of this population increased throughout the last 45 years from 170.5 cm in 1965 to 178.3 in 2010. However, the average gain in stature per decade declined from 2.4 cm in the period 1965 to 1976 to 0.8 cm per decade in 1995 to 2001, but increased to 1.0 cm in the last period. The average of body weight increased from 63.2 kg in 1965 to 73.1 in 2010 and body mass index (BMI) rose from 21.73 to 22.94 in the same period. The tempo of increase varied in different periods; between 1965 and 1986 an insignificant increase was observed (of circa 0.12); in 1986 to 1995 there was no increase, whereas the period of 2001 to 2010 witnessed a significant increase (of circa 0.76).ConclusionsThe trend of body size and stature increase within the Polish population, although decelerating, remained positive and steady during the last 45 years. No significant impact of the past half‐century's socioeconomic crises was observed in these measures of growth. We concluded that during the economic crises some effective mechanism protecting the living conditions of the children and youth were operating within the population. Am. J. Hum. Biol. 27:704–709, 2015. © 2015 Wiley Periodicals, Inc.
Two new β+‐thalassemia mutation [β ‐56 (G → C); HBBc. −106 G → C] and [β −83 (G → A); HBBc. −133 G → A] described among the Tunisian population
Authors: Douzi Kais , Moumni Imen , Zorai Amine , Ben Mustapha Maha , Ben Mansour Ikbel Mosbahi , Dorra Chaouachi , Salem Abbes 
Published: March 2015

ObjectivesDifferent thalassemia mutations have been reported in various ethnic groups and geographical regions in Tunisia. In the present study, we have investigated two rare β+‐thalassemia mutations, that have not previously been reported in the Tunisian population [β −56 (G > C); HBBc. −106 G > C] and [β −83 (G > A); HBBc. −133 G > A].MethodsThe whole β‐globin gene was directly sequenced, and haplotype analysis was conducted through a PCR/RFLP method.Results: Two new mutations were identified for the first time in Tunisia. They are located within the promoter region of β‐globin gene at position −56 (G > C) and −83 (G > A). Linkage analysis using β‐globin gene cluster haplotypes showed that these two mutations were associated with Mediterranean β‐haplotype IX [− + − + + + +] and framework 2 (FW2) [CCTCT].ConclusionsThe two newly described mutations lead to the β+‐thalassemia among Tunisian patients. The haplotype analysis and framework assignment have helped to identify the chromosomal background associated with these mutations, and determine their origin and spread. Am. J. Hum. Biol. 27:716–719, 2015. © 2015 Wiley Periodicals, Inc.