bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tectonostratigraphic evolution of the
c.
780–730 Ma Beck Spring Dolomite: Basin Formation in the core of Rodinia
Authors: Smith Emily F. , MacDonald Francis A. , Crowley James L. , Hodgin Eben B. , Schrag Daniel P. 
Published: May 2015

Abstract

The Beck Spring Dolomite is a mixed carbonate–siliciclastic succession exposed in Death Valley, California, that was deposited between 780 and 717 Ma. Along with its bounding units, the Horse Thief Springs Formation below and unit KP1 of the Kingston Peak Formation above, the Beck Spring Dolomite were deposited in one of the ChUMP (Chuar–Uinta Mountains–Pahrump) basins with subsidence commonly attributed to the nascent rifting of Rodinia. These pre-Sturtian successions preserve eukaryotic microfossil assemblages, diverse microbialites, and large carbon isotope anomalies directly below Sturtian-age glacial deposits. Here we present new geological mapping, measured stratigraphic sections, carbon isotope chemostratigraphy and detrital zircon geochronology from the Beck Spring Dolomite and its bounding units. The carbon isotope excursion at the top of the Beck Spring Dolomite has previously been attributed to meteoric diagenesis associated with karst breccias, but here we demonstrate that these breccias are instead mass flow deposits that formed during deposition of the Kingston Peak Formation and that the carbon isotope excursion is not only reproducible throughout the basin, but is associated with transgression rather than regression and exposure. In addition, we refine local correlations and discuss the use of chemostratigraphic curves from these units for regional and global correlations. The Beck Spring Dolomite was deposited during the second of three distinct basin-forming events recorded in the Pahrump Group with basin inversion occurring between each event. The presence of syn-sedimentary faults, the character of the lateral facies change and detrital zircon provenance analyses indicate that the Beck Spring Dolomite fringed a coeval palaeo-high to the south in a tectonically active basin. Detrital zircon age distributions in the Beck Spring Dolomite show sharp probability peaks at
c.
1200, 1400 and 1800 Ma, consistent with local sources to the SW in the Mojave block rather than transcontinental rivers. The
c.
1800 Ma probability peak is less prominent in the KP1 samples. In addition, KP1 also records slump folding and is overlain by an unconformity. We suggest that these features are consistent with the emergence of a local fault to the NE. Deposition of the Beck Spring Dolomite and bounding units do not record evidence of incipient rifting of the western margin of Laurentia but instead reflect a distinct and separate tectonothermal event.

Supplementary material:

Carbon (δ
13
C) and oxygen (δ
18
O) isotopic measurements, detrital zircon laser ablation inductively coupled plasma mass spectrometry (LA-ICPMS) data, detrital zircon sample information and data from reference materials used for LA-ICPMS analyses are available at
http://www.geolsoc.org.uk/SUP18823
.
miR-663 Suppresses Oncogenic Function of CXCR4 in Glioblastoma
Authors: Shi Yu , Chen Cong , Yu Shi-Zhu , Liu Qing , Rao Jun , Zhang Hua-Rong , Xiao Hua-Liang , Fu Ti-Wei , Long Hua , He Zhi-Cheng , Zhou Kai , Yao Xiao-Hong , Cui You-Hong , Zhang Xia , Ping Yi-Fang , Bian Xiu-Wu 
Published: May 2015

Abstract
Purpose: To identify the miRNA regulators of C–X–C motif chemokine receptor 4 (CXCR4) and the underlying mechanism as well as the therapeutic and prognostic values in human glioblastoma (GBM).
Experimental Design: miRNA profile analyses and bioinformatics predictions were used to identify the mediators of CXCR4, which were confirmed by luciferase reporter assay, Western blot assay and immunohistochemistry. The effects of miR-663 on CXCR4-mediated GBM malignancy were investigated by gain-of-function experiments. Orthotopic xenografts derived from constitutive or induced miR-663–expressing GBM cells were used to determine the antitumor effects of miR-663 and CXCR4-specific antagonist AMD3100. Bivariate correlation analyses were used to examine the correlation of miR-663 and CXCR4 levels in glioma. The prognostic values of miR-663 and CXCR4 were examined in 281 cases of astrocytic glioma from our hospital and 476 cases of GBM from The Cancer Genome Atlas database using the multivariate Cox regression analysis and Kaplan–Meier analysis.
Results: miR-663 negatively regulated CXCR4 expression by targeting its coding sequence in GBM and compromised the proliferative and invasive capacities of GBM cells induced by CXCR4 overexpression. Constitutive or induced miR-663 overexpression combined with CXCR4 antagonist AMD3100 suppressed orthotopic GBM growth and prolonged tumor-bearing mice survival. Clinically, miR-663 and CXCR4 were inversely correlated in GBM and composed a valuable biomarker set in predicting the outcomes of GBM patients.
Conclusions: miR-663 negatively regulated CXCR4 to inhibit its oncogenic effect. Combination of miR-663 and CXCR4 can serve as a valuable prognostic biomarker set as well as molecular targets for therapeutic intervention of GBM. Clin Cancer Res; 21(17); 4004–13. ©2015 AACR.
Fully Percutaneous Transthoracic Left Atrial Entry and Closure as a Potential Access Route for Transcatheter Mitral Valve Interventions
Authors: Rogers Toby , Ratnayaka Kanishka , Schenke William H. , Sonmez Merdim , Kocaturk Ozgur , Mazal Jonathan R. , Chen Marcus Y. , Flugelman Moshe Y. , Troendle James F. , Faranesh Anthony Z. , Lederman Robert J. 
Published: May 2015

Background—
Percutaneous access for mitral interventions is currently limited to transapical and transseptal routes, both of which have shortcomings. We hypothesized that the left atrium could be accessed directly through the posterior chest wall under imaging guidance.

Methods and Results—

We tested percutaneous transthoracic left atrial access in 12 animals (10 pigs and 2 sheep) under real-time magnetic resonance imaging or x-ray fluoroscopy plus C-arm computed tomographic guidance. The pleural space was insufflated with CO
2
to displace the lung, an 18F sheath was delivered to the left atrium, and the left atrial port was closed using an off-the-shelf nitinol cardiac occluder. Animals were survived for a minimum of 7 days. The left atrial was accessed, and the port was closed successfully in 12/12 animals. There was no procedural mortality and only 1 hemodynamically insignificant pericardial effusion was observed at follow-up. We also successfully performed the procedure on 3 human cadavers. A simulated trajectory to the left atrium was present in all of 10 human cardiac computed tomographic angiograms analyzed.

Conclusions—
Percutaneous transthoracic left atrial access is feasible without instrumenting the left ventricular myocardium. In our experience, magnetic resonance imaging offers superb visualization of anatomic structures with the ability to monitor and address complications in real-time, although x-ray guidance seems feasible. Clinical translation seems realistic based on human cardiac computed tomographic analysis and cadaver testing. This technique could provide a direct nonsurgical access route for future transcatheter mitral implantation.
Asymmetric Dimethylarginine and Cardiovascular Risk: Systematic Review and Meta‐Analysis of 22 Prospective Studies
Authors: Willeit Peter , Freitag Daniel F. , Laukkanen Jari A. , Chowdhury Susmita , Gobin Reeta , Mayr Manuel , Di Angelantonio Emanuele , Chowdhury Rajiv 
Published: May 2015

Background

Asymmetric dimethylarginine (
ADMA
) inhibits the production of nitric oxide, a key regulator of the vascular tone, and may be important in the development of cardiovascular disease (
CVD
). Our aim was to reliably quantify the association of
ADMA
and its isomer symmetric dimethylarginine (
SDMA
) with the risk of
CVD
outcomes in long‐term cohort studies.

Methods and Results

Data were collated from 22 prospective studies involving a total of 19 842 participants, which have recorded 2339
CVD
, 997 coronary heart disease, and 467 stroke outcomes during a mean follow‐up of 7.1 years. In a comparison of individuals in the top with those in the bottom third of baseline
ADMA
values, the combined risk ratios were 1.42 (95% confidence interval: 1.29 to 1.56) for
CVD
, 1.39 for coronary heart disease (1.19 to 1.62), and 1.60 for stroke (1.33 to 1.91). Broadly similar results were observed according to participants' baseline disease status (risk ratios for
CVD
: 1.35 [1.18 to 1.54] in general populations; 1.47 [1.16 to 1.87] in individuals with pre‐existing
CVD
; and 1.52 [1.26 to 1.84] in individuals with pre‐existing kidney disease) and by different study characteristics, including geographical location, sample type, assay method, number of incident outcomes, and level of statistical adjustment (all
P
values>0.05). In contrast, in 8 prospective studies involving 9070 participants and 848 outcomes, the corresponding estimate for
SDMA
concentration was 1.32 (0.92 to 1.90) for
CVD
.

Conclusions

Available prospective studies suggest associations between circulating
ADMA
concentration and
CVD
outcomes under a broad range of circumstances. Further research is needed to better clarify these associations, particularly in large general population studies.
Population-Based Study of Cerebral Microbleeds in Stroke-Free Older Adults Living in Rural Ecuador
Authors: Del Brutto Victor J. , Zambrano Mauricio , Mera Robertino M. , Del Brutto Oscar H. 
Published: May 2015

Background and Purpose—
Prevalence of cerebral microbleeds (CMB) in white and Asian populations range from 4% to 15%. However, there is no information from indigenous Latin American people. We aimed to assess prevalence and cerebrovascular correlates of CMB in stroke-free older adults living in rural Ecuador.

Methods—
Of 311 Atahualpa residents aged ≥60 years identified during a door-to-door survey, 258 (83%) underwent brain magnetic resonance imaging. Twenty-one were further excluded for a diagnosis of overt stroke. Using multivariate logistic regression models, adjusted for demographics and cardiovascular risk factors, we evaluated whether CMB were independently associated with silent strokes, white matter hyperintensities, and global cortical atrophy.

Results—

Twenty-six (11%) of 237 participants had CMB, which were single in 54% of cases. CMB were deep in 11 patients, cortical in 9, and located both deep and cortical in 6. In univariate analyses, CMB were associated with age, systolic blood pressure, moderate-to-severe white matter hyperintensities, silent lacunar infarcts, and cortical atrophy. Mean (±SD) values for systolic blood pressure were 155±27 mm Hg in patients who had CMB versus 142±26 mm Hg in those who did not (
P
=0.017). In the adjusted models, moderate-to-severe white matter hyperintensities (
P
=0.009), silent lacunar infarcts (
P
=0.003), and global cortical atrophy (
P
=0.04) were independently associated with CMB.

Conclusions—
Prevalence of CMB in stroke-free older adults living in Atahualpa is comparable with those reported from other ethnic groups. There is a strong relationship between CMB and increased age, high systolic blood pressure, silent markers of cerebral small vessel disease, and cortical atrophy.
Summertime Response of Temperature and Cooling Energy Demand to Urban Expansion in a Semiarid Environment
Authors: Salamanca F. , Georgescu M. , Mahalov A. , Moustaoui M. 
Published: May 2015

AbstractThis article explores regional impacts on near-surface air temperature and air conditioning (AC) electricity consumption due to projected urban expansion in a semiarid environment. In addition to the modern-day urban landscape setting, two projected urban expansion scenarios are analyzed with the Weather Research and Forecasting Model coupled to a multilayer building energy scheme. The authors simulate a 10-day extreme heat period at high spatial resolution (1-km horizontal grid spacing) over Arizona, one of the fastest-growing regions in the United States. Results show that replacement of natural land surfaces by buildings and pavement increases the local mean near-surface air temperature considerably. Furthermore, present-day waste heat emission from AC systems increases the mean nighttime 2-m air temperature by up to 1°C in some urban locations, but projected urban development aggravates the situation, increasing nighttime air temperatures by up to 1.5°–1.75°C. The contribution of anthropogenic heating due to AC systems is computed through comparison of two different types of numerical experiments: in one case, a specific urban scenario is simulated with the AC systems turned on and expelling heat into the outdoor environment, and in the second case, the same urban development (with the AC systems turned on) is simulated but with no heat expelled into the outdoor environment. The results demonstrate that projected urban expansion significantly amplifies local cooling energy demands for the Phoenix and Tucson metropolitan regions and therefore highlight the need for sustainable future energy needs to maintain thermal comfort levels.
Secondary Circulation of Tropical Cyclones in Vertical Wind Shear: Lagrangian Diagnostic and Pathways of Environmental Interaction
Authors: Riemer Michael , Laliberté Frédéric 
Published: May 2015

Abstract
This study introduces a Lagrangian diagnostic of the secondary circulation of tropical cyclones (TCs), here defined by those trajectories that contribute to latent heat release in the region of high inertial stability of the TC core. This definition accounts for prominent asymmetries and transient flow features. Trajectories are mapped from the three-dimensional physical space to the (two dimensional) entropy–temperature space. The mass flux vector in this space subsumes the thermodynamic characteristics of the secondary circulation. The Lagrangian diagnostic is then employed to further analyze the impact of vertical wind shear on TCs in previously published idealized numerical experiments. One focus of this analysis is the classification and quantitative depiction of different pathways of environmental interaction based on thermodynamic properties of trajectories at initial and end times. Confirming results from previous work, vertical shear significantly increases the intrusion of low–equivalent potential temperature () air into the eyewall through the frictional inflow layer. In contrast to previous ideas, vertical shear decreases midlevel ventilation in these experiments. Consequently, the difference in eyewall between the no-shear and shear experiments is largest at low levels. Vertical shear, however, significantly increases detrainment from the eyewall and modifies the thermodynamic signature of the outflow layer. Finally, vertical shear promotes the occurrence of a novel class of trajectories that has not been described previously. These trajectories lose entropy at cold temperatures by detraining from the outflow layer and subsequently warm by 10–15 K. Further work is needed to investigate in more detail the relative importance of the different pathways for TC intensity change and to extend this study to real atmospheric TCs.
Optimal Ensemble-Based Selection of Channels from Advanced Sounders in the Presence of Cloud
Authors: Migliorini Stefano 
Published: May 2015

AbstractThis study aims to illustrate a general procedure based on well-known information theory concepts to select the channels from advanced satellite sounders that are most advantageous to assimilate both in clear-sky and overcast conditions using an ensemble-based estimate of forecast uncertainty. To this end, the standard iterative channel selection method, which is used to select the most informative channels from advanced infrared sounders for operational assimilation, was revisited so as to allow its use with measurements that have correlated errors. The method was here applied to determine a 24-humidity-sensitive-channel set that is small in size relative to a total of 8461 channels that are available on the Infrared Atmospheric Sounding Interferometer (IASI) on board the EUMETSAT Polar System MetOp satellites. The selected channels can be used to perform all-sky data assimilation experiments, in addition to those currently used for operational data assimilation of IASI data at ECMWF. Care was taken to include in the observation uncertainty used for channel selection the contributions arising from imperfect knowledge of the concentration of contaminants (except for cloud) in a given spectral channel. Also, (cumulative) weighting functions that provide a vertically resolved picture of the (total) number of degrees of freedom for signal expressed by a given set of measurements were introduced, which allows for the definition of a novel channel selection merit function that can be used to select measurements that are most sensitive to variations of a given parameter over a given atmospheric region (e.g., in the troposphere).
Co-occupations: The caregiving challenges of mothers of children with cerebral palsy
Authors: Dalvand Hamid , Hosseini Seyyed Ali , Rassafiani Mehdi , Samadi Sayyed Ali , Khankeh Hamid Reza , Kelly Greg 
Published: May 2015

Introduction This study was conducted in an Iranian context to explore the co-occupations of mothers of children with cerebral palsy as experienced by them. Method This qualitative study was conducted using content analysis methodology. Sixteen mothers of children with cerebral palsy participated in the study. Data was collected via in-depth, semi-structured interviews. Constant comparative analysis was deployed for data analysis. Results The results were classified into nine sub-categories and four main categories that were identified as (1) coping with self-care problems, (2) effort to gain treatment follow-up, (3) coping challenges of educational care, and (4) limited parental personal leisure time. Conclusion Understanding the challenges of caring for a child with cerebral palsy and the experiences of mothers when engaging in co-occupations with their child, provides a broader perspective of the potential impact on participation and engagement of mothers. However, more research is required to understand the various factors influencing participation and co-occupations and interaction effects between these factors.
Burnout among Nursing Professionals in Tertiary Care Hospitals of Delhi
Authors: Negi Yashika , Bagga Rajni 
Published: May 2015

Introduction: There has been growing evidence that stress and burnout at work have undesirable effects not only on the worker but also on the organizations (Aiken et al. 2002a, 2002b; Felton 1998). It is perceived more among nursing professionals because of the specific roles and responsibilities, increased workload, dealing with high-risk cases, emotional aspects of patient care and other factors inherent in the nature of work. Objective: This article is developed with the broad objective to determine the level of burnout among the nursing professionals with the following specific objectives: To determine the level of burnout and to determine the work-related factors associated with burnout among nursing professionals in selected tertiary care hospitals of Delhi. Methodology: This descriptive study was carried out on a total of 200 staff nurses. One hundred staff nurses from each of the two randomly selected tertiary care hospitals in New Delhi were taken, comprising 25 staff nurses from each of the four speciality wards (Medicine, Surgery, Obstetrics & Gynaecology and Paediatrics). Tools used were socio-demographic tool, work profile tool and standardized Maslach Burnout Inventory (MBI) tool to measure burnout. Data were analyzed using Statistical Package for Social Sciences (SPSS) version 17. Results: Overall, the nurses reported a low mean score for emotional exhaustion (14.39 ± 6.87) and depersonalization (4.84 ± 3.34), and an average score (34.72 ± 6.33) for personal accomplishment. Work profile variables found to be associated with burnout were ‘staff shortage with respect to nurse–patient ratio’, ‘number of night duties’, ‘demands of patient’ attendants’, ‘duty roster’, ‘death/critical condition of a patient’, ‘conflicts at work place’, study leave’ and ‘category of employment (regular/contractual)’. Conclusions and Recommendations: Though the nurses, in the present study, did not show very high levels of burnout, nonetheless, there was noted a significant association of burnout with certain work profile and organizational factors. On this ground, one can conclude that a lot of reforms are required at the organizational and work environmental levels. On the basis of these findings and conclusions formed, the authors suggest certain recommendations, in which reforms for human resource (HR) for health form a prominent part.
Characterization of the Antithrombotic Fingerprint of the Branded and Copies of the Low-Molecular-Weight Enoxaparin Using Thrombin Generation Assay
Authors: Gerotziafas Grigoris T. , Rouseau Aurèlie , Mbemba Elisabeth , Khartechi Amir , Van Dreden Patrick , Walenga Janine , Fareed Jawed , Elalamy Ismail 
Published: May 2015

Background: The patent protection of low-molecular-weight heparins (LMWHs) expired, so the definition of criteria for the biological similarity between LMWH copies and the original product is a real need. Aim: The present in vitro study compared copies and branded enoxaparin using the specific anti-Xa activity and the calibrated automated thrombogram assay. Methods: Samples of platelet-poor plasma (PPP) and platelet-rich plasma (PRP) from 15 healthy volunteers were spiked with branded enoxaparin (Lovenox) or its copies (Cutenox, Dilutol, Enoxa, Fibrinox, Loparin, Lupenox, Novex, Noxprin, and Versa). The specific anti-Xa activity was measured in PPP, and thrombin generation was assessed in PPP and PRP in the presence of tissue factor or pancreatic cancer cells BXPC3. Results: The anti-Xa activity of enoxaparin copies ranged from 0.072 to 0.088 IU/μg, being lower as compared to the branded enoxaparin (0.095 anti-Xa IU/μg). The potency of each copy to inhibit thrombin generation varied in the 3 experimental systems. The presence of platelets or pancreatic cancer cells BXPC3 in human plasma induced significant modifications in the inhibitory efficiency of enoxaparin copies on thrombin generation, which distinguished them from the branded product. Conclusion: Enoxaparin copies showed significant variability regarding their inhibitory potency on thrombin generation. Platelets and cancer cells significantly increased the variability of the antithrombotic efficiency of the copies as compared to the branded enoxaparin. The present study underlines the need for the elaboration of additional functional criteria to evaluate the global antithrombotic capacity of enoxaparin copies in order to evaluate their potential sameness with the branded drug.