bluuebunny/crossref_metadata_2025 huggingface dataset:
Categorizing the Meteorological Origins of Critical Ramp Events in Collective Photovoltaic Array Output
Authors: Wellby Sonya J. , Engerer Nicholas A.
Published: December 2015

Photovoltaic (PV) solar power use is increasing globally. The Australian Capital Territory (ACT) has legislated a renewable energy target of 90% by 2020; to reach this target, use of distributed PV solar arrays is expected to increase. Cloud cover can cause the power output of PV installations to rapidly increase or decrease, resulting in ACT-wide collective ramp events. Accurate forecasts of when the ramp events will occur are needed for electricity providers to plan for these abrupt output changes and to ensure that electricity supplies remain stable. This paper categorizes the weather events that cause changes in the output of rooftop PV arrays in the ACT, providing a foundation for future PV output forecasting to be based on weather event identification. This paper identifies citywide collective ramp events, which occur when a 60% change in collective PV power output (with respect to the clear-sky potential) is experienced within 60 min. Such events are termed critical collective ramp events. Throughout the period between January 2012 and July 2014, 34 critical ramp events occurred. Eighteen of these events were positive collective ramp events, caused most frequently by Australian northwest cloud bands and radiation fog dissipation. Sixteen negative collective ramp events were recorded, and they were caused most frequently by the passage of cold fronts and thunderstorms. The categories developed herein will make it possible to improve short-term solar forecasting methods and to enable meteorologists to contribute to forecasting critical events.
Satellite Air–Sea Enthalpy Flux and Intensity Change of Tropical Cyclones over the Western North Pacific
Authors: Gao Si , Zhai Shunan , Chiu Long S. , Xia Dong
Published: December 2015

An improved high-resolution satellite enthalpy flux dataset is employed to study the composites of initial (i.e., t = 0 h) latent heat flux (LHF), sensible heat flux (SHF), and their bulk variables associated with four intensity-change categories of tropical cyclones (TCs) over the western North Pacific Ocean—rapidly intensifying (RI), slowly intensifying, neutral, and weakening—in a vertical wind shear–relative coordinate system with horizontal dimensions normalized by the radius of maximum wind. Results show that RI TCs are associated with significantly higher LHF and SHF in all TC environments than non-RI TCs, which are mainly attributable to the air–sea humidity difference (DQ) and the air–sea temperature difference (DT), respectively. Higher DQ and DT are primarily due to significantly higher sea surface temperature (SST) underlying RI TCs, emphasizing the crucial role of SST in supplying more energy to TCs that undergo rapid intensification, in which LHF plays a more important role than SHF. Relative to non-RI TCs, LHF and SHF for RI TCs show a more symmetric pattern. The magnitude and pattern of air–sea enthalpy flux could serve as potential predictors for rapid intensification of TCs.
A Statistical Method for Categorical Drought Prediction Based on NLDAS-2
Authors: Hao Zengchao , Hao Fanghua , Xia Youlong , Singh Vijay P. , Hong Yang , Shen Xinyi , Ouyang Wei
Published: December 2015

Drought is a slowly varying natural phenomenon and may have wide impacts on a range of sectors. Tremendous efforts have therefore been devoted to drought monitoring and prediction to reduce potential impacts of drought. Reliable drought prediction is critically important to provide information ahead of time for early warning to facilitate drought-preparedness plans. The U.S. Drought Monitor (USDM) is a composite drought product that depicts drought conditions in categorical forms, and it has been widely used to track drought and its impacts for operational and research purposes. The USDM is an assessment of drought condition but does not provide drought prediction information. Given the wide application of USDM, drought prediction in a categorical form similar to that of USDM would be of considerable importance, but it has not been explored thus far. This study proposes a statistical method for categorical drought prediction by integrating the USDM drought category as an initial condition with drought information from other sources such as drought indices from land surface simulation or statistical prediction. Incorporating USDM drought categories and drought indices from phase 2 of the North American Land Data Assimilation System (NLDAS-2), the proposed method is tested in Texas for 2001–14. Results show satisfactory performance of the proposed method for categorical drought prediction, which provides useful information to aid early warning for drought-preparedness plans.
Quadrant-Dependent Evolution of Low-Level Tangential Wind of a Tropical Cyclone in the Shear Flow
Authors: Gu Jian-Feng , Tan Zhe-Min , Qiu Xin
Published: December 2015

This study investigates the quadrant-by-quadrant evolution of the low-level tangential wind near the eyewall of an idealized simulated mature tropical cyclone embedded in a unidirectional shear flow. It is found that the quadrant-averaged tangential wind in the right-of-shear quadrants weakens continuously, while that in the left-of-shear quadrants experiences a two-stage evolution: a quasi-steady stage followed by a weakening stage after the imposing of vertical wind shear. This leads to a larger weakening rate in the right-of-shear and a stronger jet in the left-of-shear quadrants. The budget analysis shows that the quadrant-dependent evolution of tangential wind is controlled through the balance between the generalized Coriolis force (GCF; i.e., the radial advection of absolute angular momentum) and the advection terms. The steady decreasing of the GCF is primarily responsible for the continuous weakening of jet strength in the right-of-shear quadrants. For the left-of-shear quadrants, the quasi-steady stage is due to the opposite contributions by the enhanced GCF and negative tendency of advections cancelling out each other. The later weakening stage is the result of both the decreased GCF and the negative tangential advection. The combination of storm-relative flows at vortex scale and the convection strength both within and outside the eyewall determines the evolution of boundary layer inflow asymmetries, which in turn results in the change of GCF, leading to the quadrant-dependent evolution of low-level jet strength and thus the overall storm intensity change.
Numerical Archetypal Parameterization for Mesoscale Convective Systems
Authors: Yano Jun-Ichi , Moncrieff Mitchell W.
Published: December 2015

Vertical shear commonly organizes atmospheric convection into coherent multiscale structures. The associated countergradient vertical transport of horizontal momentum by organized convection can enhance the wind shear and transport kinetic energy upscale. However, organized convection and its upscale effects are not represented by traditional mass-flux-based parameterizations. The present paper sets the archetypal dynamical models, originally formulated by the second author, into a parameterization context by utilizing a nonhydrostatic anelastic model with segmentally constant approximation (NAM–SCA). Using a two-dimensional framework as a starting point, NAM–SCA spontaneously generates propagating tropical squall lines in a sheared environment. High numerical efficiency is achieved through a novel compression methodology. The numerically generated archetypes produce vertical profiles of convective momentum transport that are consistent with the analytic archetype.
Assimilation of Mode-S EHS Aircraft Observations in COSMO-KENDA
Authors: Lange Heiner , Janjić Tijana
Published: December 2015

Aircraft observations of wind and temperature collected by airport surveillance radars [Mode-S Enhanced Surveillance (Mode-S EHS)] were assimilated in the Consortium for Small-Scale Modeling Kilometre-scale Ensemble Data Assimilation (COSMO-KENDA), which couples an ensemble Kalman filter to a 40-member ensemble of the convection permitting COSMO-DE model. The number of observing aircrafts in Mode-S EHS was about 15 times larger than in the AMDAR system. In the comparison of both aircraft observation systems, a similar observation error standard deviation was diagnosed for wind. For temperature, a larger error was diagnosed for Mode-S EHS. With the high density of Mode-S EHS observations, a reduction of temperature and wind error in forecasts of 1 and 3 hours was found mainly in the flight level and less near the surface. The amount of Mode-S EHS data was reduced by random thinning to test the effect of a varying observation density. With the current data assimilation setup, a saturation of the forecast error reduction was apparent when more than 50% of the Mode-S EHS data were assimilated. Forecast kinetic energy spectra indicated that the reduction in error is related to analysis updates on all scales resolved by COSMO-DE.
Gender and entrepreneurship revisited from a community perspective: experiences in a new immigrant gateway and beyond
Authors: Wang Qingfang , Morrell Elizabeth
Published: December 2015

Women-owned enterprises have boomed significantly during the past several decades. The purpose of this study is to theorize and empirically delineate the connections between female entrepreneurship and community development through the lens of entrepreneurship. Our results indicate that, from the initial creation of these businesses, to their daily operations and resource mobilization through social networks, women entrepreneurs are closely connected to local communities through their business activities. At the same time, as engagement and payback to local communities are fundamental to their professional goals and operation strategies, female entrepreneurship activities have significantly contributed to local communities in a wide range of ways. The dialectical connections between women business owners and their communities have significant potential to be incorporated into community development policies and practices.
Beyond technology and finance: pay-as-you-go sustainable energy access and theories of social change
Authors: Rolffs Paula , Ockwell David , Byrne Rob
Published: December 2015

Two-thirds of people in sub-Saharan Africa lack access to electricity, a precursor of poverty reduction and development. The international community has ambitious commitments in this regard, e.g. the UN's Sustainable Energy for All by 2030. But scholarship has not kept up with policy ambitions. This paper operationalises a sociotechnical transitions perspective to analyse for the first time the potential of new, mobileenabled, pay-as-you-go approaches to financing sustainable energy access, focussing on a case study of pay-as-you-go approaches to financing solar home systems in Kenya. The analysis calls into question the adequacy of the dominant, two-dimensional treatment of sustainable energy access in the literature as a purely financial/technology, economics/ engineering problem (which ignores sociocultural and political considerations) and demonstrates the value of a new research agenda that explicitly attends to theories of social change – even when, as in this paper, the focus is purely on finance. The paper demonstrates that sociocultural considerations cut across the literature's traditional two-dimensional analytic categories (technology and finance) and are material to the likely success of any technological or financial intervention. It also demonstrates that the alignment of new payas- you-go finance approaches with existing sociocultural practices of paying for energy can explain their early success and likely longevity relative to traditional finance approaches.
The melting-pot and the economic integration of immigrant families: ancestral and generational variations in Australia
Authors: Johnston Ron , Forrest James , Jones Kelvyn , Manley David , Owen Dewi
Published: December 2015

The melting-pot argument, whereby economically heterogeneous multi-cultural societies, characterised by high levels of immigration from a variety of origins, become more homogeneous over time, has attracted much attention, especially in North America. Australia has similarly experienced major waves of immigration from a wide range of cultural backgrounds. This paper reports successful tests of hypotheses, derived from the melting-pot model, that economic integration of immigrant groups there has also resulted in reduced inter-group occupational and income differences across successive generations, but that the pace of integration can vary across ethnic groups. Using a bespoke tabulation from the 2011 Australian census we explore differences among ten immigrant (ancestry) groups in their educational qualifications, and their occupational and income distributions, using a recently developed method to identify significant patterns within large contingency tables. We find that by the third generation there were no substantial differences either across the ten groups chosen to represent four main waves of immigration to Australia or between these groups and the non-immigrant population.
‘Go Away, Mute English!’ Selling English in Web Advertising
Authors: Shinhee Lee Jamie
Published: December 2015

Triggered by the increasing use of the Internet, the ‘English learning boom’ and ‘English fever’ in South Korea, web advertising is used by English language institutes as one of the most popular modalities of marketing to compete in the highly competitive domestic English-language teaching market. This study examines 20 randomly selected web-advertising texts about English language institutes and programmes in South Korea. The findings of the study suggest that the concept of ‘global’ is commonly incorporated into cyber marketing materials, recurring as the main rationale for why Koreans need to study English. Native-speaker favouritism is also unequivocally present in instructional staff-related ads, highlighting the importance of learning ‘authentic’ English. This study argues that English is used not only as a means of advertising, but also the product itself, performing a dual purpose in web marketing for English language teaching in contemporary South Korea.
Determinants of Consumers’ Attitude towards Social Media Advertising
Authors: Boateng Henry , Okoe Abednego Feehi
Published: December 2015

The purpose of this study was to examine the factors determining consumers’ attitude towards social media advertising. The survey research design was employed as the research design. Validity and reliability of the measures were assessed using confirmatory factor analysis. Additionally, structural equation modelling was used to examine the structural model. Credibility, materialism, value corruption and corporate reputation are found to have an effect on consumers’ attitudes towards social media advertising. This study provides evidence of the role of corporate reputation in consumers’ attitudes towards social media advertising. Recommendations of the study have been provided.
Narcissism, Masochism and the Reconstituted Male—Masculine Performances in Fight Club and The Wrestler
Authors: John Vimal Mohan , Viswamohan Aysha Iqbal
Published: December 2015

The article reads David Fincher’s Fight Club (1999) and Darren Aronofsky’s film The Wrestler (2008) as films that deploy masochistic spectacles of heroically suffering white men. Both Fincher and Aronofsky are well known for their dark and sometimes surreal films that frequently take up violence as a theme (Mayshark, 2007). They are also prominent auteurial voices, nominated for and winning multiple prominent film awards. Both Fincher and Aronofsky are, the article argues, representatives of a class of American directors who, starting in the early 1990s, made independent art house films and won accolades at various film festivals, making anti-mainstream, if not subversive cinema. These filmmakers of the 1990s sustained the spirit of enquiry that was the hallmark of the auteurs of the New Hollywood age.

Our contention is that Fincher’s Fight Club and Aronofsky’s The Wrestler can be accommodated on this list as films made by subversive filmmakers and that they share common features owing to their commitment to explore constructions of masculinity and performances of the same. The question that the article seeks to address is—does David Savran’s framework offered in Taking it Like a Man: White Masculinity, Masochism, and Contemporary American Culture (1998) predict the distinct male posturing of masochistically suffering white men visible in Fight Club and The Wrestler? The article will primarily use the theoretical framework offered by David Savran to examine where Fight Club and The Wrestler are situated with respect to the mainstream Hollywood fare featuring hyper-masculine heroes.
Reverse Engineering and Evaluation of Prediction Models for Progression to Type 2 Diabetes
Authors: Anderson Jeffrey P. , Parikh Jignesh R. , Shenfeld Daniel K. , Ivanov Vladimir , Marks Casey , Church Bruce W. , Laramie Jason M. , Mardekian Jack , Piper Beth Anne , Willke Richard J. , Rublee Dale A.
Published: December 2015

Background:

Application of novel machine learning approaches to electronic health record (EHR) data could provide valuable insights into disease processes. We utilized this approach to build predictive models for progression to prediabetes and type 2 diabetes (T2D).

Methods:

Using a novel analytical platform (Reverse Engineering and Forward Simulation [REFS]), we built prediction model ensembles for progression to prediabetes or T2D from an aggregated EHR data sample. REFS relies on a Bayesian scoring algorithm to explore a wide model space, and outputs a distribution of risk estimates from an ensemble of prediction models. We retrospectively followed 24 331 adults for transitions to prediabetes or T2D, 2007-2012. Accuracy of prediction models was assessed using an area under the curve (AUC) statistic, and validated in an independent data set.

Results:

Our primary ensemble of models accurately predicted progression to T2D (AUC = 0.76), and was validated out of sample (AUC = 0.78). Models of progression to T2D consisted primarily of established risk factors (blood glucose, blood pressure, triglycerides, hypertension, lipid disorders, socioeconomic factors), whereas models of progression to prediabetes included novel factors (high-density lipoprotein, alanine aminotransferase, C-reactive protein, body temperature; AUC = 0.70).

Conclusions:

We constructed accurate prediction models from EHR data using a hypothesis-free machine learning approach. Identification of established risk factors for T2D serves as proof of concept for this analytical approach, while novel factors selected by REFS represent emerging areas of T2D research. This methodology has potentially valuable downstream applications to personalized medicine and clinical research.
A Digital Ecosystem of Diabetes Data and Technology
Authors: Heintzman Nathaniel D.
Published: December 2015

The management of type 1 diabetes (T1D) ideally involves regimented measurement of various health signals; constant interpretation of diverse kinds of data; and consistent cohesion between patients, caregivers, and health care professionals (HCPs). In the context of myriad factors that influence blood glucose dynamics for each individual patient (eg, medication, activity, diet, stress, sleep quality, hormones, environment), such coordination of self-management and clinical care is a great challenge, amplified by the routine unavailability of many types of data thought to be useful in diabetes decision-making. While much remains to be understood about the physiology of diabetes and blood glucose dynamics at the level of the individual, recent and emerging medical and consumer technologies are helping the diabetes community to take great strides toward truly personalized, real-time, data-driven management of this chronic disease. This review describes “connected” technologies—such as smartphone apps, and wearable devices and sensors—which comprise part of a new digital ecosystem of data-driven tools that can link patients and their care teams for precision management of diabetes. These connected technologies are rich sources of physiologic, behavioral, and contextual data that can be integrated and analyzed in “the cloud” for research into personal models of glycemic dynamics, and employed in a multitude of applications for mobile health (mHealth) and telemedicine in diabetes care.
Students on Move
Authors: Wadhwa Rashim
Published: December 2015

In recent years, the overall context of global mobility has significantly changed, so has the strategies to attract international students. What we observe now is the changes in strategies and the emergence of new host countries and increased opportunities for studying abroad. In an intense competitive environment of global higher education market, host countries are targeting students from Asian origin in general and Indian students in particular. Increasing competition for international students has caused complexities in choices and decision-making process adopted by students. It is observed that the new student body of a middle-class segment are also becoming a part of mobile students. This pattern has deepened the element of heterogeneity among students going abroad. There is direct implication of these changes for the countries particularly in the area of recruitment and retention and strategic international student marketing. This article explores the decision-making process of different segments of students. The methodology of the article involves a sample of 362 prospective and 55 currently abroad Indian students. For the analysis of the data, a binary logistic regression model has been used. Findings of this study will provide an understanding of push and pull factors driving mobility of Indian students. This article will provide international students’ recruiters a better understanding of choices made by the students and how to use different marketing strategies.
What Do Ode to Joy, the Nobel Peace Prize, Umbrellas and Cartoons Have in Common? Why Critical Thinking Matters and How Higher Education Moulds
Authors: Franco Amanda
Published: December 2015

Critical thinking is the kind of ‘good’ thinking used in everyday life to increase the chances of success. A critical thinker combines skill and will when working the odds in one’s advantage. Nevertheless, thinking is very often far from rational. Since people are built to believe, since living is all about choosing and since education liberates, critical thinking is essential: in higher education, in the job market and in everyday life. Yet, it needs explicit instruction and inclusion in the curriculum. This article, grounded on current literature and oriented towards the future, addresses the higher mission of higher education. Higher education must aim to prepare individuals to become active citizens, who address life as a process of meaningful lifelong learning and who are devoted to non-stop regulation of thinking and behaviour, which are guided by ethics and evidence for personal and common prosperity and, more important, freedom.
Engaging Social Constructivist Teaching in the Diverse Learning Environment; Perspectives from a First Year Faculty Member
Authors: Flint Emilia S.
Published: December 2015

It is no secret that the student attending university classes today is different from the learner of several years ago (Blakefield, 2013). Educators have been recently encouraged to shift the paradigm of traditional lecture-style education to incorporate service-learning and experiential activities involving media and technology whenever possible so that classroom instruction will appeal to the next generation of students (Gagliardi, 2007). This essay will discuss the preparation and personal experiences of a first–year faculty member creating a new course design for teaching History of Psychology to include a socially constructed classroom that appeals to the learner. Course design is based on the social constructivist philosophy that involves discovering truths in a collaborative format with the instructor facilitating truth discovery. Use of technology was left up to the individual learner and learning outcomes were achieved through use of learning contracts. Each student in the classroom set up a contract unique to his or her needs based on demonstrating learning outcome achievement to the course instructor on various benchmark occasions throughout the semester. Challenges and risks will be explored, as will be suggestions for future course designs based on student feedback and instructor experience.
Education Exclusion in a Social-class Framework
Authors: Rajasenan D. , Bijith G.A. , Rajeev B.
Published: December 2015

Education and education exclusion are two mammoth social and political challenges in a society characterized by diverse social groups. Although ‘self-financing regime’ helped to barricade the outflow of money from the state, it also hampered the ‘social equity’ in education and hence germinated the seed of education exclusion in Kerala. The data for the study have been collected through a field survey involving 900 students belonging to three professional study disciplines in a social-class framework based on multi-stage stratified random sampling. Factor analysis, correspondence analysis and binary logistic regression have been used to epitomize the significant factors that play a key role in the process of education exclusion in a social-class framework based on student perception. Empirical realities affirm significant relations for the presence of education exclusion among the marginalized social groups. Skill rating based on social category shows a clear inter-community difference with Scheduled Castes (SCs)/Scheduled Tribes (STs) coming in the low/medium and low skill index, whereas the general and the Other Backward Class (OBC)/other eligible communities (OEC) featuring closer to medium–high and high-skill index. A demand supply evaluation is necessary for policy nesting, with a view of understanding the gap involved in the process as part of the professional education planning in the state.
Geologic events coupled with Pleistocene climatic oscillations drove genetic variation of Omei treefrog (Rhacophorus omeimontis) in southern China
Authors: Li Jun , Zhao Mian , Wei Shichao , Luo Zhenhua , Wu Hua
Published: December 2015

Background

Pleistocene climatic oscillations and historical geological events may both influence current patterns of genetic variation, and the species in southern China that faced unique climatic and topographical events have complex evolutionary histories. However, the relative contributions of climatic oscillations and geographical events to the genetic variation of these species remain undetermined. To investigate patterns of genetic variation and to test the hypotheses about the factors that shaped the distribution of this genetic variation in species of southern China, mitochondrial genes (cytochrome b and NADH dehydrogenase subunit 2) and nine microsatellite loci of the Omei tree frog (Rhacophorus omeimontis) were amplified in this study.

Results

The genetic diversity in the populations ofR. omeimontiswas high. The phylogenetic trees reconstructed from the mitochondrial DNA (mtDNA) haplotypes and the Bayesian genetic clustering analysis based on microsatellite data both revealed that all populations were divided into three lineages (SC, HG and YN). The two most recent splitting events among the lineages coincided with recent geological events (including the intense uplift of the Qinghai-Tibet Plateau, QTP and the subsequent movements of the Yun-Gui Plateau, YGP) and the Pleistocene glaciations. Significant expansion signals were not detected in mismatch analyses or neutrality tests. And the effective population size of each lineage was stable during the Pleistocene.

Conclusions

Based on the results of this study, complex geological events (the recent dramatic uplift of the QTP and the subsequent movements of the YGP) and the Pleistocene glaciations were apparent drivers of the rapid divergence of theR. omeimontislineages. Each diverged lineages survivedin situwith limited gene exchanges, and the stable demographics of lineages indicate that the Pleistocene climatic oscillations were inconsequential for this species. The analysis of genetic variation in populations ofR. omeimontiscontributes to the understanding of the effects of changes in climate and of geographical events on the dynamic development of contemporary patterns of genetic variation in the species of southern China.
Multidisciplinary geophysical investigations over an alpine rock glacier
Authors: Merz Kaspar , Maurer Hansruedi , Rabenstein Lasse , Buchli Thomas , Springman Sarah M. , Zweifel Matthias
Published: December 2015

We have performed a multidisciplinary geophysical survey combined with geotechnical investigations over a degrading alpine rock glacier. A dense grid of helicopter-borne ground-penetrating radar data allowed the 3D shape of the bedrock topography and the gross transition from ice-rich to ice-poor parts of the rock glacier to be delineated. The bedrock topography served as a 2D structural constraint for tomographic inversions of seismic and geoelectric data acquired on coincident profiles parallel and perpendicular to the rock glacier flow direction. These profile data were complemented by a small 3D geoelectric tomography experiment. Only a combined interpretation of all the results allowed reliable and unambiguous interpretation of the tomograms. We could distinguish between the active layer, bedrock, ice-bearing rock glacier material, and degraded permafrost within the rock glacier. The latter could be further distinguished in areas where the ice must have melted only recently, and regions that had degraded some time ago. Additionally, high-resolution cross-hole radar tomography, performed in an area of opening crevices, allowed small-scale structures to be resolved, which were indicative of the dominant deformation mechanisms style of the rock glacier. The success of our study was primarily based on the availability of 3D data sets that allowed important structures to be traced over larger areas and the integrated interpretation of several data types. We have identified the internal structure of the rock glacier to be surprisingly heterogeneous with several small-scale features that were judged to be critical for assessing its stability. This underpinned the need for comprehensive 3D structural investigations to augment geotechnical measurements linearly with inclinometers or at points in boreholes.
Helicopter-borne transient electromagnetics in high-latitude environments: An application in the McMurdo Dry Valleys, Antarctica
Authors: Foley Neil , Tulaczyk Slawek , Auken Esben , Schamper Cyril , Dugan Hilary , Mikucki Jill , Virginia Ross , Doran Peter
Published: December 2015

The McMurdo Dry Valleys are a polar desert in coastal Antarctica, where glaciers, permafrost, ice-covered lakes, and ephemeral summer streams coexist. Liquid water is found at the surface only in lakes and in the temporary streams that feed them. Past geophysical exploration has yielded ambiguous results regarding the presence of subsurface water. In 2011, we used a helicopter-borne, time-domain electromagnetic (TDEM) sensor to map resistivity in the subsurface across the Dry Valleys. The airborne electromagnetic (AEM) method excels at finding subsurface liquid water in polar deserts, where water remains liquid under cold conditions if it is sufficiently saline, and therefore electrically conductive. Over the course of 26 h of helicopter time, we covered large portions of the Dry Valleys and vastly increased our geophysical understanding of the subsurface, particularly with respect to water. Our data show extensive subsurface low-resistivity layers approximately 150–250 m below the surface and beneath higher resistivity layers. We interpret the low-resistivity layers as geologic materials containing freeze-concentrated or “cryoconcentrated” hyper saline brines lying beneath glaciers and frozen permafrost. These brines appeared to be contiguous with surface lakes, subglacial regions, and the Ross Sea, which could indicate a regional-hydrogeologic system, wherein solutes might be transported between surface reservoirs by ionic diffusion and subsurface flow. The presence of such brines underneath glaciers might have implications for glacier movement. Systems such as this, where brines exist beneath glacial ice and frozen permafrost, may exist elsewhere in coastal Antarctica; AEM resistivity is an ideal tool to find and survey them. Our application of TDEM demonstrates that in polar subsurface environments containing conductive brines, such a diffusive electromagnetic method is superior to radar surveying in terms of depth of penetration and ability to differentiate hydrogeologic conditions.
Metabolic Effects of Long-Term Reduction in Free Fatty Acids With Acipimox in Obesity: A Randomized Trial
Authors: Makimura Hideo , Stanley Takara L. , Suresh Caroline , De Sousa-Coelho Ana Luisa , Frontera Walter R. , Syu Stephanie , Braun Laurie R. , Looby Sara E. , Feldpausch Meghan N. , Torriani Martin , Lee Hang , Patti Mary-Elizabeth , Grinspoon Steven K.
Published: December 2015

Context:

Increased circulating free fatty acids (FFAs) have been proposed to contribute to insulin resistance in obesity. Short-term studies have investigated the effects of acipimox, an inhibitor of hormone-sensitive lipase, on glucose homeostasis, but longer-term studies have not been performed.

Objective:

To test the hypothesis that long-term treatment with acipimox would reduce FFA and improve insulin sensitivity among nondiabetic, insulin-resistant, obese subjects.

Design, Setting, Patients, and Intervention:

At an academic medical center, 39 obese men and women were randomized to acipimox 250 mg thrice-daily vs identical placebo for 6 months.

Main Outcome Measures:

Plasma lipids, insulin sensitivity, adiponectin, and mitochondrial function via assessment of the rate of post-exercise phosphocreatine recovery on 31P-magnetic resonance spectroscopy as well as muscle mitochondrial density and relevant muscle gene expression.

Results:

Fasting glucose decreased significantly in acipimox-treated individuals (effect size, −6 mg/dL; P = .02), in parallel with trends for reduced fasting insulin (effect size, −6.8 μU/mL; P = .07) and HOMA-IR (effect size, −1.96; P = .06), and significantly increased adiponectin (effect size, +668 ng/mL; P = .02). Acipimox did not affect insulin-stimulated glucose uptake, as assessed by euglycemic, hyperinsulinemic clamp. Effects on muscle mitochondrial function and density and on relevant gene expression were not seen.

Conclusion:

These data shed light on the long-term effects of FFA reduction on insulin sensitivity, other metabolic parameters, and muscle mitochondrial function in obesity. Reduced FFA achieved by acipimox improved fasting measures of glucose homeostasis, lipids, and adiponectin but had no effect on mitochondrial function, mitochondrial density, or muscle insulin sensitivity.
The HABP2 G534E Variant Is an Unlikely Cause of Familial Nonmedullary Thyroid Cancer
Authors: Sahasrabudhe Ruta , Stultz Jacob , Williamson John , Lott Paul , Estrada Ana , Bohorquez Mabel , Palles Claire , Polanco-Echeverry Guadalupe , Jaeger Emma , Martin Lynn , Echeverry Maria Magdalena , Tomlinson Ian ,   on behalf of members of TCUKIN*, Carvajal-Carmona Luis G.
Published: December 2015

Context:

A recent study reported the nonsynonymous G534E (rs7080536, allele A) variant in the HABP2 gene as causal in familial nonmedullary thyroid cancer (NMTC).

Objective:

The objective of this study was to evaluate the causality of HABP2 G534E in the TCUKIN study, a multicenter population-based study of NMTC cases from the British Isles.

Design and Setting:

A case-control analysis of rs7080536 genotypes was performed using 2105 TCUKIN cases and 5172 UK controls.

Participants:

Cases comprised 2105 NMTC cases. Patient subgroups with papillary (n = 1056), follicular (n = 691), and Hürthle cell (n = 86) thyroid cancer cases were studied separately. Controls comprised 5172 individuals from the 1958 Birth Cohort and the National Blood Donor Service study. The controls had previously been genotyped using genome-wide single nucleotide polymorphism arrays by the Wellcome Trust Case Control Consortium study.

Outcome Measures:

Association between HABP2 G534E (rs7080536A) and NMTC risk was evaluated using logistic regression.

Results:

The frequency of the HABP2 G534E was 4.2% in cases and 4.6% in controls. We did not detect an association between this variant and NMTC risk (odds ratio [OR] = 0.896; 95% confidence interval, 0.746–1.071; P = .233). We also failed to detect an association between the HABP2 G534E and cases with papillary (1056 cases; G534E frequency = 3.5%; OR = 0.74; P = .017), follicular (691 cases; G534E frequency = 4.7%; OR = 1.00; P = 1.000), or Hürthle cell (86 cases; G534E frequency = 6.3%; OR = 1.40; P = .279) histology.

Conclusions:

We found that HABP2 G534E is a low-to-moderate frequency variant in the British Isles and failed to detect an association with NMTC risk, independent of histological type. Hence, our study does not implicate HABP2 G534E or a correlated polymorphism in familial NMTC, and additional data are required before using this variant in NMTC risk assessment.
A Simplified Method of Accurate Postprocessing of Diffusion Tensor Imaging for Use in Brain Tumor Resection
Authors: Bonney Phillip A. , Conner Andrew K. , Boettcher Lillian B. , Cheema Ahmed A. , Glenn Chad A. , Smitherman Adam D. , Pittman Nathan A. , Sughrue Michael E.
Published: December 2015

BACKGROUND: Use of diffusion tensor imaging (DTI) in brain tumor resection has been limited in part by a perceived difficulty in implementing the techniques into neurosurgical practice.

OBJECTIVE: To demonstrate a simple DTI postprocessing method performed without a neuroscientist and to share results in preserving patient function while aggressively resecting tumors.

METHODS: DTI data are obtained in all patients with tumors located within presumed eloquent cortices. Relevant white matter tracts are mapped and integrated with neuronavigation by a nonexpert in < 20 minutes. We report operative results in 43 consecutive awake craniotomy patients from January 2014 to December 2014 undergoing resection of intracranial lesions. We compare DTI-expected findings with stimulation mapping results for the corticospinal tract, superior longitudinal fasciculus, and inferior fronto-occipital fasciculus.

RESULTS: Twenty-eight patients (65%) underwent surgery for high-grade gliomas and 11 patients (26%) for low-grade gliomas. Seventeen patients had posterior temporal lesions; 10 had posterior frontal lesions; 8 had parietal-temporal-occipital junction lesions; and 8 had insular lesions. With DTI-defined tracts used as a guide, a combined 65 positive maps and 60 negative maps were found via stimulation mapping. Overall sensitivity and specificity of DTI were 98% and 95%, respectively. Permanent speech worsening occurred in 1 patient (2%), and permanent weakness occurred in 3 patients (7%). Greater than 90% resection was achieved in 32 cases (74%).

CONCLUSION: Accurate DTI is easily obtained, postprocessed, and implemented into neuronavigation within routine neurosurgical workflow. This information aids in resecting tumors while preserving eloquent cortices and subcortical networks.
Immigrants Equilibrate Local Labor Markets: Evidence from the Great Recession
Authors: Cadena Brian C. , Kovak Brian K.
Published: December 2015

This paper demonstrates that low-skilled Mexican-born immigrants' location choices respond strongly to changes in local labor demand, which helps equalize spatial differences in employment outcomes for low-skilled native workers. We leverage the substantial geographic variation in labor demand during the Great Recession to identify migration responses to local shocks and find that low-skilled Mexican-born immigrants respond much more strongly than low-skilled natives. Further, Mexican mobility reduced the incidence of local demand shocks on natives, such that those living in metro areas with a substantial Mexican-born population experienced a roughly 50 percent weaker relationship between local shocks and local employment probabilities. (JEL E32, J15, J23, J24, J61, R23)
Advances of Nanotechnologies in Oil and Gas Industries
Authors: Yang Jiang , Ji Sixue , Li Ran , Qin Wenlong , Lu Yongjun
Published: December 2015

Many functional materials have been used in oil and gas industries. Special materials were needed for to withstand the high temperature and pressure harsh environment of oil and gas reservoir. Nanotechnologies have the potential to introduce revolutionary changes of materials used in the areas of the oil and gas industries. This paper gives an overview of the nanotechnology application for enhanced oil recovery, fracturing fluids, flow assurance, drilling, completion and specialty composite in the oil and gas industry in the last few years. Applications of nano-materials, in the form of solid composites and functional nanoparticle-fluid in these areas are reviewed. The future challenges of nanotech-based solutions for the petroleum industry are also discussed.
Evaluation of Nanoparticle Shape Effect on a Nanofluid Based Flat-Plate Solar Collector Efficiency
Authors: Amin Toghi Eshghi , Roghayeh Ghasempour , Fatemeh Razi , Fatollah Pourfayaz
Published: December 2015

Solar thermal energy is a very convenient source of heating which is environmentally benign. Solar collectors convert solar radiation into heat and transfer the heat to a medium. Flat-plate solar collectors are the most common and cost effective devices for exploiting solar energy. However, these systems have relatively low efficiency due to the poor thermo-physical properties of working fluid. Dispersing of nanometer sized particles into the base fluid is proposed as an efficient method to improve heat transfer properties of the working fluid. In order to evaluate the thermal performance of nanofluid in a solar collector, firstly, it is essential to understand the thermo-physical variations of base fluid through addition of nanoparticles. Thermo-physical properties of base fluid vary with parameters such as particle concentration, particle diameter, and particle shape. In this study the effect of these parameters are explored on thermal performance of a flat-plate solar collector theoretically. Investigating shape effect of particles on collector efficiency is a highlight in this study. It is observed that increasing nanoparticles volumetric concentration leads to enhancenement in flat-plate collector efficiency. Reversely, particle size enhancement reduces the efficiency. In addition, particle shape affects collector efficiency. For different shapes of particles, including spherical, brick, cylinders, platelets, and blades, the blade shape particles relatively have the highest efficiency.
Comparative Analysis on Water Movability in Pores of Different Reservoir Rocks by Nuclear Magnetic Resonance
Authors: Li Song , Tang Dazhen , Xu Hao , Pan Zhejun , Huang Weiqiang , Zhu Xueguang
Published: December 2015

Based on nuclear magnetic resonance (NMR) relaxation theory, the mathematical model between T2 value and pore size was proposed. The model results showed that small pores have low T2 values, while large pores have high T2 values. Thus, different reservoir rocks, owing to their diverse pore structures, have different T2 distribution characteristics when water-saturation condition is 100%. NMR experiments with different reservoir rocks under different centrifugal speeds were performed. The comparison of pore structures and water movability in diverse rocks was analyzed based on the NMR experimental results. As centrifugal speed increased, water was progressively expelled from the rocks. There are significant differences in the declining in the water saturation and the area of T2 spectrum per unit volume (ST) of all the four samples. The water saturation declining in clastic rocks is higher than that of coals. Moreover, both T2 peaks of clastic rocks corresponding to small and large pores successively decreased, while for coals, the peaks with low T2 values were hardly affected, which is consistent with the results of water saturation declining. This is because the low T2 values correspond to the adsorption pores in coal, from which water is hard to drain out, and since coal rocks are dominant by adsorption pores, the water movability of coals is lower than that of clastic rocks.
Present-Day Heat Flow, Thermal History, and Tectonic Subsidenceof the Jianghan Basin
Authors: Li Zongxing , Gao Jun , Liu Chenglin , Xu Ming
Published: December 2015

Thermal gradient distribution of the Jianghan Basin is obtained based on systematic steady-state and oil-test temperature data. The present geothermal gradient and terrestrial heat flow of 18 wells are calculated in the Jianghan Basin. A total of 9 measured terrestrial heat flow values are reported based on detailed thermal conductivity data and systematic steady-state temperature data. These values vary from 41.9 to 60.9 mW/m2, with a mean value of 52.3 ± 6.3 mW/m2. However, thermal history analyses, derived from vitrinite reflectance (RO) and apatite fission track (AFT) data, indicate that the Jianghan Basin was at a stable stage before the Indosinian movement. The heat flow increased and reached its maximum value of ∼68 mW/m2 during the Late Indosinian to Early Yanshan period. Since the Late Himalayan period, rapidly decreasing basement heat flow made the Jianghan Basin cool down. Furthermore, geohistory analysis reveals that the tectonic subsidence of the Jianghan Basin from the Cretaceous to Early Miocene was characterized by initial synrift subsidence followed by thermal subsidence. The thermal and tectonic subsidence history have directly effects on petroleum source rock maturation, so their analyses are of great significance forpetroleum exploration and hydrocarbon source assessment in the Jianghan Basin.
Charging History of Crude Oils in the Slope Belt of the Southern Junggar Foreland Basin, NW China: A Case Study from the East Edge of Chepaizi High
Authors: Xiao Fei , Liu Luofu , Wu Kangjun , Zhou Changxiao , Xu Zhengjian , Deng Sizhe , Bai Xueying
Published: December 2015

The east edge of Chepaizi High belongs to the western slope belt of the southern Junggar foreland basin, NW China. Based on the features of oil source and migration pathway, this study rebuilt the charging history of crude oils related to the slope belt reservoir forming in the east edge of Chepaizi High, comprehensively through the methods of fluid inclusion microscopic observation, microthermometry and microbeam fluorescence spectra. The results show that there are mainly 4 periods of oil charging including the Middle Jurassic to the Middle Cretaceous (the 1st period), the Middle-Late Cretaceous to the Early Paleogene (the 2nd period), the Early Neogene (the 3rd period) and the Middle-Late Neogene to the Quaternary (the 4th period). The 1st and 2nd period oils both generated from the Permian Wuerhe source rock charged into the Mesozoic reservoirs. The 1st period oil is low-mature to mature with long time and large-scale volume of oil charging, while the 2nd period oil was mature to highly mature with short time and small-scale volume of oil charging. Partial 1st period oil suffered biodegradation because of poor preservation conditions resulted from tectonic uplift in the Late Jurassic. In the Early Neogene, biodegraded oil gradually migrated into the shallow reservoirs and formed the secondary heavy oil reservoirs as the 3rd charging period. The 4th period oil was mainly from the Jurassic source rock. Through the migration pathways composited by sand bodies, faults and unconformities, the oil migrated into the Neogene Shawan reservoirs and formed the light oil reservoirs. Meanwhile, the oil was overprinted by some low maturity Cretaceous organic matter during upward migration, and some oil from the Jurassic source rock got mixed with the earlier charging heavy oils. For different tectonic evolution stages, there existed distinct oil charging characteristics in the study area.