bluuebunny/crossref_metadata_2025 huggingface dataset:
Analytical approach for characterization of morphology and chemistry of a CH3NH3PbI3/TiO2 solar cell layered system
Authors: Rades Steffi , Oswald Frederic , Narbey Stephanie , Radnik Jörg , Hodoroaba Vasile‐Dan
Published: March 2018

Manufacturing of new perovskite layered solar cells with constant high light conversion efficiency over time may be hampered by the loss of efficiency caused by structural and/or chemical alterations of the complex layered system. SEM/EDX combined with XPS were chosen as an appropriate methodical approach to characterize perovskite laboratory cells in depth and at surface, before and after light exposure. The layered perovskite system investigated here is based on glass covered with fluorine doped tin oxide, followed by thin films of TiO2, ZrO2, and a thick monolithic carbon. TiO2 film is subdivided into a dense layer covered by porous one constituted of nanoparticles of truncated bipyramidal shape. This layered system serves as the matrix for the perovskite. EDX spectral maps on cross sections of specimen have shown that Pb and I are distributed homogeneously throughout the porous layers C, ZrO2, and TiO2. SEM/EDX data show that 20 weeks of ambient daylight did not change significantly the in‐depth distribution of the elemental composition of Pb and I throughout the entire solar cell system. It was confirmed with EDX that nanoparticles identified in high‐resolution SEM micrographs contain mainly Pb and I, indicating these to be the perovskite crystals. However, a compositional and chemical altering began in the near‐surface region of the outermost ~10 nm after 2 months of illumination which was observed with XPS.
Environmental water efficiency: Maximizing benefits and minimizing costs of environmental water use and management
Authors: Horne Avril C. , O'Donnell Erin L , Loch Adam J. , Adamson David C. , Hart Barry , Freebairn John
Published: March 2018

Environmental water management is a relatively new discipline, with concepts, management practice and institutional mechanisms that are still emerging. The efficient and effective use of environmental water to maximize environmental benefits, or environmental water use efficiency, is one such emerging concept. Currently, much of the focus is on allocative efficiency, where the objective is to achieve a better balance between consumptive and environmental water uses in a cost‐effective way. However, this may not provide the most efficient and effective way to manage environmental water in the long term, where managers are seeking productive (or operational) efficiency. Here, the objective is to maximize environmental outcomes relative to the cost of managing the available resource. This paper explores the concept of water use efficiency in the context of environmental water.

This article is categorized under:

Engineering Water > Planning Water

Human Water > Value of Water
Evolution of complexity following a global quench
Authors: Moosa Mudassir
Published: March 2018

Abstract

The rate of complexification of a quantum state is conjectured to be bounded from above by the average energy of the state. A different conjecture relates the complexity of a holographic CFT state to the on-shell gravitational action of a certain bulk region. We use ‘complexity equals action’ conjecture to study the time evolution of the complexity of the CFT state after a global quench. We find that the rate of growth of complexity is not only consistent with the conjectured bound, but it also saturates the bound soon after the system has achieved local equilibrium.
A Commentary on Commercial Genetic Testing and the Future of the Genetic Counseling Profession
Authors: Wolff Nicholas D. , Wolff Jon A.
Published: March 2018

Commercial genetic testing laboratories are increasingly employing genetic counselors. As a result, the role of these or many genetic counselors is shifting from primarily direct patient counseling in clinics and hospitals to more laboratory‐centered activities that involve case coordination, customer liaison, variant classification, marketing, and sales. Given the importance of these commercial entities to the genetic counseling profession, this commentary examines the current financial situation of four publicly traded, genetic testing companies. It also explores how the various roles of genetic counselors are likely to be affected by the financial pressures these companies face.
Maternity Leave and Mothers’ Long-Term Sickness Absence: Evidence From West Germany
Authors: Guertzgen Nicole , Hank Karsten
Published: March 2018

Exploiting unique German administrative data, we estimate the association between an expansion in maternity leave duration from two to six months in 1979 and mothers’ postbirth long-term sickness absence over a period of three decades after childbirth. Adopting a difference-in-difference approach, we first assess the reform’s labor market effects and, subsequently, prebirth and postbirth maternal long-term sickness absence, accounting for the potential role of the reform in mothers’ selection into employment. Consistent with previous research, our estimates show that the leave extension caused mothers to significantly delay their return to work within the first year after childbirth. We then provide difference-in-difference estimates for the number and length of spells of long-term sickness absence among returned mothers. Our findings suggest that among those returned, mothers subject to the leave extension exhibit a higher incidence of long-term sickness absence compared with mothers who gave birth before the reform. This also holds true after we control for observable differences in prebirth illness histories. At the same time, we find no pronounced effects on mothers’ medium-run labor market attachment following the short-run delay in return to work, which might rationalize a negative causal health effect. Breaking down the results by mothers’ prebirth health status suggests that the higher incidence of long-term sickness absence among mothers subject to the reform may be explained by the fact that the reform facilitated the reentry of a negative health selection into the labor market.
Very low‐protein diet to postpone renal failure: Pathophysiology and clinical applications in chronic kidney disease
Authors: Bellizzi Vincenzo , Calella Patrizia , Carrero Juan Jesus , Fouque Denis
Published: March 2018

The uremic syndrome is a metabolic disorder characterized by the impairment of renal handling of several solutes, the resulting accumulation of toxic products and the activation of some adaptive but detrimental mechanisms which all together contribute to the progression of renal damage. In moderate to advanced renal failure, the dietary manipulation of nutrients improves metabolic abnormalities and may contribute to delay the time of dialysis initiation. This commentary focuses on the physiopathological rationale and the clinical application of the very low‐protein diet supplemented with ketoanalogs for the management of chronic kidney disease.
Precarity in Angolan diamond mining towns, 1920–2014: tracing agency of the state, mining companies and urban households
Authors: Udelsmann Rodrigues Cristina , Bryceson Deborah Fahy
Published: March 2018

After nearly 30 years of civil war, Angola gained peace in 2002. The country's diamond and oil wealth affords the national government the means to pursue economic reconstruction and urban development. However, in the diamond-producing region of Lunda Sul, where intense fighting between MPLA and UNITA forces was waged, the legacy of war lingers on in the form of livelihood uncertainty and uneven access to the benefits of the state's urban development programmes. There are three main interactive agents of urban change: the Angolan state, the mining corporations, and not least urban residents. The period has been one of shifting alignments of responsibility for urban housing, livelihoods and welfare provisioning. Beyond the pressures of post-war adjustment, the wider context of global capital investment and labour market restructuring has introduced a new surge of corporate mining investment and differentiated patterns of prosperity and precarity in Lunda Sul.
Response to Christopher Jones: The Historicity of the Neronian Persecution
Authors: Shaw Brent D.
Published: March 2018

In theJournal of Roman Studiesof 2015, I argued that the evidence in Tacitus for a state-directed punishment of Christians in Rome in 64cewas too weak to sustain the historical interpretation of it as a persecution. In a reply in this journal last year, Christopher Jones argued that knowledge of Christians under that name could well have reached Rome by the mid-60s, that thevulgusof the city could well have accused such persons, and that the Tacitean account is therefore generally credible. While admitting the justice of some of his criticisms, I attempt in this reply to clarify some of my arguments and to restate my original claim that a persecution of Christians by the emperor Nero in connection with the Great Fire of 64 seems improbable given the context of the relations between officials of the Roman state and Christians over the first centuryce.
Folding of copper proteins: role of the metal?
Authors: Ariöz Candan , Wittung-Stafshede Pernilla
Published: March 2018

Copper is a redox–active transition metal ion required for the function of many essential human proteins. For biosynthesis of proteins coordinating copper, the metal may bind before, during or after folding of the polypeptide. If the metal binds to unfolded or partially folded structures of the protein, such coordination may modulate the folding reaction. The molecular understanding of how copper is incorporated into proteins requires descriptions of chemical, thermodynamic, kinetic and structural parameters involved in the formation of protein–metal complexes. Because free copper ions are toxic, living systems have elaborate copper-transport systems that include particular proteins that facilitate efficient and specific delivery of copper ions to target proteins. Therefore, these pathways become an integral part of copper protein folding in vivo. This review summarizes biophysical-molecular in vitro work assessing the role of copper in folding and stability of copper-binding proteins as well as protein–protein copper exchange reactions between human copper transport proteins. We also describe some recent findings about the participation of copper ions and copper proteins in protein misfolding and aggregation reactions in vitro.
Validity of caregiver-report measures of language skill for Wolof-learning infants and toddlers living in rural African villages
Authors: WEBER Ann M. , MARCHMAN Virginia A. , DIOP Yatma , FERNALD Anne
Published: March 2018

Valid indigenous language assessments are needed to further our understanding of how children learn language around the world. We assessed the psychometric properties and performance of two caregiver-report measures of Wolof language skill (language milestones achieved and vocabulary knowledge) for 500 children (ages 0;4 to 2;6) living in rural Senegal. Item response models (IRM) evaluated instrument- and item-level performance and differential function by gender. Both caregiver-report measures had good psychometric properties and displayed expected age and socioeconomic effects. Modest concurrent validity was found by comparing the caregiver-report scores to transcribed child language samples from a naturalistic play session. The caregiver-report method offers a valid alternative to more costly tools, such as direct behavioral assessments or language sampling, for measuring early language development in non-literate, rural African communities. Recommendations are made to further improve the performance of caregiver-report measures of child language skill in these settings.
Toward Delegation: Social Policy Centralization in Toronto, 1870–1929
Authors: Lucas Jack
Published: March 2018

Scholars of social policy development in the United States and elsewhere have recently focused on the historical and contemporary importance of complex, delegated welfare state governance. In this article, I outline the emergence of a coordinated urban welfare state in the city of Toronto between 1870 and 1929, describing the creation of both public and private forms of coordination and centralization. I argue that we must understand social policy development in this period as resulting from the interaction of three policy coalitions: municipal traditionalists, municipal progressives, and social work professionals, and that social policy centralization occurred as a result of an alliance between municipal progressives and social work professionals. To explain the long-term development of social policy in Canada and elsewhere, I argue, we must understand the interaction among these internal coalitions in the social policy field and the ways that broader fiscal and cultural changes strengthened or weakened each coalition over time.
“Outside the Pyramid”: Clerical Work, Corporate Affirmative Action, and Working Women’s Barriers to Upward Mobility
Authors: Elias Allison L.
Published: March 2018

Although women have made tremendous gains at work, a striking degree of sex segregation still exists. For a generation of women who were working in low-paying, administrative support positions during the promising era of Title VII, affirmative action did not offer upward mobility. In the 1970s, as employers and regulators began implementing affirmative action amid the gendered structure of internal labor markets, women who were already in clerical roles remained outside the managerial pipeline. Women in 9to5, the National Association of Working Women, sought to bridge the gap between female-dominated clerical and male-dominated managerial ladders using collective action. Yet business and government did not enforce affirmative action such that the clustering of women in low-paid clerical positions constituted discrimination on the basis of sex. Work experience on the clerical ladder remains inadequate training for positions on the managerial ladder.
A Forgotten Chapter in the History of International Commercial Arbitration: The Slave Trade's Dispute Settlement System
Authors: MARTINEAU ANNE-CHARLOTTE
Published: March 2018

This article is part of the ongoing efforts to write a critical history of international arbitration in commercial and investment matters. It examines the ways in which the Spanish crown and its concessionaries set up a mechanism to settle legal disputes pertaining to the transatlantic slave trade. The transformation ofasientos de negrosfrom limited royal contracts to large-scale monopolies awarded to foreign chartered companies during the sixteenth, seventeenth and early eighteenth centuries was accompanied by the creation of an international commercial arbitration system. Why was this system set up, how did it work, and what was its faith? The overall aim of the article is to invite international lawyers to rethink the history of international arbitration and pay closer attention to the ‘private’ dimensions of formal and informal imperialism. It also attempts to bridge the historical investigation and contemporary commentary. In the conclusion, I argue that this study allows us, in a mirroring effect, to question the idea that today's dispute settlement mechanism was conceived as a means to ‘depoliticize’ international investment law. What the introduction of arbitration achieves is to place some fundamental questions out of sight. Today, as in the past, arbitrators work from within the system; their work rests on a series of unspoken – and yet highly political – premises about the organization of economic life and the distribution of values.
A Sharp Dirac–Erdős Type Bound for Large Graphs
Authors: KIERSTEAD H. A. , KOSTOCHKA A. V. , McCONVEY A.
Published: March 2018

Let k ⩾ 3 be an integer, hk(G) be the number of vertices of degree at least 2k in a graph G, and ℓk(G) be the number of vertices of degree at most 2k − 2 in G. Dirac and Erdős proved in 1963 that if hk(G) − ℓk(G) ⩾ k2 + 2k − 4, then G contains k vertex-disjoint cycles. For each k ⩾ 2, they also showed an infinite sequence of graphs Gk(n) with hk(Gk(n)) − ℓk(Gk(n)) = 2k − 1 such that Gk(n) does not have k disjoint cycles. Recently, the authors proved that, for k ⩾ 2, a bound of 3k is sufficient to guarantee the existence of k disjoint cycles, and presented for every k a graph G0(k) with hk(G0(k)) − ℓk(G0(k)) = 3k − 1 and no k disjoint cycles. The goal of this paper is to refine and sharpen this result. We show that the Dirac–Erdős construction is optimal in the sense that for every k ⩾ 2, there are only finitely many graphs G with hk(G) − ℓk(G) ⩾ 2k but no k disjoint cycles. In particular, every graph G with |V(G)| ⩾ 19k and hk(G) − ℓk(G) ⩾ 2k contains k disjoint cycles.
The Association between Cardiopulmonary Resuscitation in Out-of-Hospital Settings and Chest Injuries: A Retrospective Observational Study
Authors: Takayama Wataru , Koguchi Hazuki , Endo Akira , Otomo Yasuhiro
Published: March 2018

Objectives

The aim of this study was to assess the risk of cardiopulmonary resuscitation (CPR) performed in out-of-hospital settings for chest injuries in patients with out-of-hospital cardiac arrest (OHCA).

Methods

This retrospective, observational study was conducted in an emergency critical care medical center in Japan. Non-traumatic OHCA patients transferred to the hospital from April 2013 through August 2016 were analyzed. The outcome was defined by chest injuries related to CPR, which is composite of rib fractures, sternal fractures, and pneumothoraces. A multivariate logistic regression analysis was performed to assess the independent risk factors for chest injuries related to CPR. The threshold of out-of-hospital CPR duration that increased risk of chest injuries was also assessed.

Results

A total of 472 patients were identified, of whom 233 patients sustained chest injuries. The multivariate logistic regression model showed that the independent risk factors for chest injuries were age and out-of-hospital CPR duration (age: AOR=1.06 [95% CI, 1.04 to 1.07]; out-of-hospital CPR duration: AOR=1.03 [95% CI, 1.01 to 1.05]). In-hospital CPR duration was not an independent risk factor for chest injuries. When the duration of out-of-hospital CPR extended over 15 minutes, the likelihood of chest injuries increased; however, this association was not statistically significant.

Conclusions

Long duration of out-of-hospital CPR was an independent risk factor for chest injuries, possibly due to the difficulty of maintaining adequate quality of CPR. Further investigations to assess the efficacy of alternative CPR devices are expected in cases requiring long transportation times.

TakayamaW, KoguchiH, EndoA, OtomoY. The association between cardiopulmonary resuscitation in out-of-hospital settings and chest injuries: a retrospective observational study. Prehosp Disaster Med. 2018;33(2):171–175.
Why the everyday in China, today?
Authors: Zhu Jianfei
Published: March 2018

Nothing is more urgent in China today than a critique of the everyday; and a social analysis of the conditions and prospects of ordinary individuals vis-à-vis – or despite – the achievements of the nation and the state. Jia Zhangke's film, Still Life (2006), reveals this urgency vividly, describing the destruction of local settlements and the dislocation of ordinary people amidst the great engineering feat of dams and bridges over the Yangtze River. A husband and a wife, having lost contact with each other for years because of hectic careers and radical socio-spatial dislocation, finally meet and agree to divorce. With sounds of music flowing down distantly, they dance for a minute and bid farewell, with one watching and the other walking away, disappearing into the distance against a vast landscape of debris and magnificent structures building-up behind them. This scene was followed immediately by another depicting a tourist cruise on the river with a loudspeaker reciting a Li Bai poem from the eighth century: poetic words about a scenic spot that would soon be flooded for the building of the Three Gorges Dam, to power an industrial China on the rise.
How accurate is the prevalence of overweight and obesity in children and adolescents derived from self-reported data? A meta-analysis
Authors: He Jinbo , Cai Zhihui , Fan Xitao
Published: March 2018

Objective

The aim of the current meta-analysis was to evaluate the accuracy of using BMI based on self-reported height and weight (BMIsr) to estimate the prevalence of overweight and obesity among children and adolescents.

Design

A systematic literature search was conducted to select studies that compared the prevalence rates of overweight and obesity based on BMIsrand BMIm(BMI based on measured height and weight). A random-effect model was assumed to estimate summary prevalence rates and prevalence ratio (PR).

Results

Thirty-seven studies were included. The aggregated prevalence of overweight and obesity based on BMIsr(0·190, 95 % CI 0·163, 0·221) was significantly lower than that based on BMIm(0·233, 95 % CI 0·203, 0·265). The pooled mean PR was 0·823 (95 % CI 0·775, 0·875). Moderator analyses showed that the underestimation was related to gender, age, weight status screened (overweightv. obesity) and weight status screening tool.

Conclusions

BMIsrmay produce less biased results under some conditions than others. Future researchers using BMIsrmay consider these findings and avoid the conditions that could lead to more severe underestimation of the prevalence of overweight and obesity among children and adolescents.
Can't wait to get my pension: the effect of raising the female early retirement age on income, poverty and deprivation
Authors: CRIBB JONATHAN , EMMERSON CARL
Published: March 2018

We estimate the impact of increasing the female early retirement age (ERA) on household living standards. Examining the increase in the female ERA from 60 to 63 in the UK, we find increased earnings only partially offset lost public pension income, leaving affected women's household incomes £32 per week lower on average. The proportional effect was substantially larger for women in lower income households. This increased the income poverty rate among affected women by 6.4 percentage points. We find no evidence of an increased inability to afford important material items, potentially suggesting that material deprivation has been avoided through smoothing of consumption.
Relational use of an electronic quality of life and practice support system in hospital palliative consult care: A pilot study
Authors: Krawczyk Marian , Sawatzky Richard
Published: March 2018

Objectives

This study is part of an overarching research initiative on the development and integration of an electronic Quality of Life and Practice Support System (QPSS) that uses patient-reported outcome and experience measures in clinical practice. The current study focused on palliative nurse consultants trialing the QPSS with older hospitalized adults receiving acute care. The primary aim of the study was to better understand consultants’ and patients’ experiences and perspectives of use.

Method

The project involved two nurse specialists within a larger palliative outreach consult team (POCT) and consenting older adult patients (age 55+) in a large tertiary acute care hospital in western Canada. User-centered design of the QPSS was informed by three focus groups with the entire POCT team, and implementation was evaluated by direct observation as well as interviews with the POCT nurses and three patients. Thematic analysis of interviews and field notes was informed by theoretical perspectives from social sciences.

Result

Over 9 weeks, the POCT nurses used the QPSS at least once with 20 patients, for a total of 47 administrations. The nurses most often assisted patients in using the QPSS. Participants referenced three primary benefits of relational use: enhanced communication, strengthened therapeutic relations, and cocreation of new insights about quality of life and care experiences. The nurses also reported increased visibility of quality of life concerns and positive development as relational care providers.

Significance of results

Participants expressed that QPSS use positively influenced relations of care and enhanced practices consistent with person-centered care. Results also indicate that electronic assessment systems may, in some instances, function as actor-objects enabling new knowledge and relations of care rather than merely as a neutral technological platform. This is the first study to examine hospital palliative consult clinicians’ use of a tablet-based system for routine collection of patient-reported outcome and experience measures.
Theory Production: Made In or For Latin America?
Authors: Falleti Tulia G.
Published: March 2018

The essay by Murillo, Shrank, and Luna constitutes a much-needed and welcome wake-up call for those of us who study Latin America—and for political scientists more generally. The authors make a plea for “a rigorous, comparative, and empirically grounded” study of Latin American political economy. I fully agree with their diagnosis of this field and their recommendations. I also praise the authors for defining political economy broadly—rather than narrowly, through a focus on research methods. They understand political economy to encompass all the economic, social, and political factors that are either contextual conditions or consequences of major macroeconomic transformations. Thus the authors lay out an important research agenda for the study of Latin American political economy that includes not only issues of economic development and inequality, but also patterns of democratic politics, state capacities, the rule of law, identity politics, and international linkages, among others. For the authors, the major political and economic transformations that the region has undergone since the start of the twentyfirst century—in its postneoliberal era—cry out for a contextualized research agenda and, I would add, open a host of opportunities for theoretical and conceptual innovation.
Strange Bedfellows? Attitudes toward Minority and Majority Religious Symbols in the Public Sphere
Authors: Bilodeau Antoine , Turgeon Luc , White Stephen , Henderson Ailsa
Published: March 2018

In this study, we contend that distinguishing individuals who support bans onminorityreligious symbols from those who want to banallreligious symbols improves our understanding of the roots of opposition to minority religious symbols in the public sphere. We hypothesize that both groups are likely driven by markedly different motivations and that opposition to the presence of minority religious symbols in the public sphere may be the result of an alliance between “strange bedfellows,” clusters of individuals whose political outlooks usually bring them to opposite sides of political debates. Drawing on a survey conducted in the province of Quebec (Canada), we find that while holding liberal values and low religiosity are key characteristics of those who would ban all religious symbols, feelings of cultural threat and generalized prejudice are central characteristics of those who would only restrict minority religious symbols. Negative attitudes specifically toward Muslims, however, also appear to motivate both groups.
Differences in Growth Reading Patterns for at-Risk Spanish-Monolingual Children as a Function of a Tier 2 Intervention
Authors: Crespo Patricia , Jiménez Juan E. , Rodríguez Cristina , Baker Doris , Park Yonghan
Published: March 2018

The present study compares the patterns of growth of beginning reading skills (i.e., phonemic awareness, phonics, fluency, vocabulary and comprehension) of Spanish speaking monolingual students who received a Tier 2 reading intervention with students who did not receive the intervention. All the students in grades K-2 were screened at the beginning of the year to confirm their risk status. A quasi-experimental longitudinal design was used: the treatment group received a supplemental program in small groups of 3 to 5 students, for 30 minutes daily from November to June. The control group did not receive it. All students were assessed three times during the academic year. A hierarchical linear growth modeling was conducted and differences on growth rate were found in vocabulary in kindergarten (p< .001; variance explained = 77.0%), phonemic awareness in kindergarten (p< .001; variance explained = 43.7%) and first grade (p< .01; variance explained = 15.2%), and finally we also find significant growth differences for second grade in oral reading fluency (p< .05; variance explained = 15.1%) and retell task (p< .05; variance explained = 14.5%). Children at risk for reading disabilities in Spanish can improve their skills when they receive explicit instruction in the context of Response to Intervention (RtI). Findings are discussed for each skill in the context of implementing a Tier 2 small group intervention within an RtI approach. Implications for practice in the Spanish educational context are also discussed for children who are struggling with reading.
Intracellular Desmoglein-2 cleavage sensitizes epithelial cells to apoptosis in response to pro-inflammatory cytokines
Authors: Yulis Mark , Quiros Miguel , Hilgarth Roland , Parkos Charles A. , Nusrat Asma
Published: March 2018

Abstract

Desmosomal cadherins mediate intercellular adhesion and have also been shown to regulate homeostatic signaling in epithelial cells. We have previously reported that select pro-inflammatory cytokines induce Dsg2 ectodomain cleavage and shedding from intestinal epithelial cells (IECs). Dsg2 extracellular cleaved fragments (Dsg2 ECF) function to induce paracrine pro-proliferative signaling in epithelial cells. In this study, we show that exposure of IECs to pro-inflammatory cytokines interferon-gamma (IFN-γ) and tumor necrosis factor-alpha (TNF-α) resulted in Dsg2 intracellular cleavage and generation of a ~55 kDa fragment (Dsg2 ICF). Dsg2 intracellular cleavage is mediated by caspase-8 and occurs prior to Dsg2 extracellular cleavage and the execution of apoptosis. Expression of exogenous Dsg2 ICF in model IECs resulted in increased sensitivity to apoptotic stimuli and apoptosis execution. Additionally, expression of the Dsg2 ICF repressed the anti-apoptotic Bcl-2 family member proteins Bcl-XL and Mcl1. Taken together, our findings identify a novel mechanism by which pro-inflammatory mediators induce modification of Dsg2 to activate apoptosis and eliminate damaged cells, while also promoting release of Dsg2 ECF that promotes proliferation of neighboring cells and epithelial barrier recovery.
Amplification of heat extremes by plant CO2 physiological forcing
Authors: Skinner Christopher B. , Poulsen Christopher J. , Mankin Justin S.
Published: March 2018

Plants influence extreme heat events by regulating land-atmosphere water and energy exchanges. The contribution of plants to changes in future heat extremes will depend on the responses of vegetation growth and physiology to the direct and indirect effects of elevated CO2. Here we use a suite of earth system models to disentangle the radiative versus vegetation effects of elevated CO2 on heat wave characteristics. Vegetation responses to a quadrupling of CO2 increase summer heat wave occurrence by 20 days or more—30–50% of the radiative response alone—across tropical and mid-to-high latitude forests. These increases are caused by CO2 physiological forcing, which diminishes transpiration and its associated cooling effect, and reduces clouds and precipitation. In contrast to recent suggestions, our results indicate CO2-driven vegetation changes enhance future heat wave frequency and intensity in most vegetated regions despite transpiration-driven soil moisture savings and increases in aboveground biomass from CO2 fertilization.
How RNA transcripts coordinate DNA recombination and repair
Authors: McDevitt Shane , Rusanov Timur , Kent Tatiana , Chandramouly Gurushankar , Pomerantz Richard T.
Published: March 2018

Genetic studies in yeast indicate that RNA transcripts facilitate homology-directed DNA repair in a manner that is dependent on RAD52. The molecular basis for so-called RNA−DNA repair, however, remains unknown. Using reconstitution assays, we demonstrate that RAD52 directly cooperates with RNA as a sequence-directed ribonucleoprotein complex to promote two related modes of RNA−DNA repair. In a RNA-bridging mechanism, RAD52 assembles recombinant RNA−DNA hybrids that coordinate synapsis and ligation of homologous DNA breaks. In an RNA-templated mechanism, RAD52-mediated RNA−DNA hybrids enable reverse transcription-dependent RNA-to-DNA sequence transfer at DNA breaks that licenses subsequent DNA recombination. Notably, we show that both mechanisms of RNA−DNA repair are promoted by transcription of a homologous DNA template in trans. In summary, these data elucidate how RNA transcripts cooperate with RAD52 to coordinate homology-directed DNA recombination and repair in the absence of a DNA donor, and demonstrate a direct role for transcription in RNA−DNA repair.
Light-triggered enzymatic reactions in nested vesicle reactors
Authors: Hindley James W. , Elani Yuval , McGilvery Catriona M. , Ali Simak , Bevan Charlotte L. , Law Robert V. , Ces Oscar
Published: March 2018

Cell-sized vesicles have tremendous potential both as miniaturised pL reaction vessels and in bottom-up synthetic biology as chassis for artificial cells. In both these areas the introduction of light-responsive modules affords increased functionality, for example, to initiate enzymatic reactions in the vesicle interior with spatiotemporal control. Here we report a system composed of nested vesicles where the inner compartments act as phototransducers, responding to ultraviolet irradiation through diacetylene polymerisation-induced pore formation to initiate enzymatic reactions. The controlled release and hydrolysis of a fluorogenic β-galactosidase substrate in the external compartment is demonstrated, where the rate of reaction can be modulated by varying ultraviolet exposure time. Such cell-like nested microreactor structures could be utilised in fields from biocatalysis through to drug delivery.
Apolipoprotein AI prevents regulatory to follicular helper T cell switching during atherosclerosis
Authors: Gaddis Dalia E. , Padgett Lindsey E. , Wu Runpei , McSkimming Chantel , Romines Veronica , Taylor Angela M. , McNamara Coleen A. , Kronenberg Mitchell , Crotty Shane , Thomas Michael J. , Sorci-Thomas Mary G. , Hedrick Catherine C.
Published: March 2018

Regulatory T (Treg) cells contribute to the anti-inflammatory response during atherogenesis. Here we show that during atherogenesis Treg cells lose Foxp3 expression and their immunosuppressive function, leading to the conversion of a fraction of these cells into T follicular helper (Tfh) cells. We show that Tfh cells are pro-atherogenic and that their depletion reduces atherosclerosis. Mechanistically, the conversion of Treg cells to Tfh cells correlates with reduced expression of IL-2Rα and pSTAT5 levels and increased expression of IL-6Rα. In vitro, incubation of naive T cells with oxLDL prevents their differentiation into Treg cells. Furthermore, injection of lipid-free Apolipoprotein AI (ApoAI) into ApoE−/− mice reduces intracellular cholesterol levels in Treg cells and prevents their conversion into Tfh cells. Together our results suggest that ApoAI, the main protein in high-density lipoprotein particles, modulates the cellular fate of Treg cells and thus influences the immune response during atherosclerosis.
Increase in hepatic and decrease in peripheral insulin clearance characterize abnormal temporal patterns of serum insulin in diabetic subjects
Authors: Ohashi Kaoru , Fujii Masashi , Uda Shinsuke , Kubota Hiroyuki , Komada Hisako , Sakaguchi Kazuhiko , Ogawa Wataru , Kuroda Shinya
Published: March 2018

Insulin plays a central role in glucose homeostasis, and impairment of insulin action causes glucose intolerance and leads to type 2 diabetes mellitus (T2DM). A decrease in the transient peak and sustained increase of circulating insulin following an infusion of glucose accompany T2DM pathogenesis. However, the mechanism underlying this abnormal temporal pattern of circulating insulin concentration remains unknown. Here we show that changes in opposite direction of hepatic and peripheral insulin clearance characterize this abnormal temporal pattern of circulating insulin concentration observed in T2DM. We developed a mathematical model using a hyperglycemic and hyperinsulinemic-euglycemic clamp in 111 subjects, including healthy normoglycemic and diabetic subjects. The hepatic and peripheral insulin clearance significantly increase and decrease, respectively, from healthy to borderline type and T2DM. The increased hepatic insulin clearance reduces the amplitude of circulating insulin concentration, whereas the decreased peripheral insulin clearance changes the temporal patterns of circulating insulin concentration from transient to sustained. These results provide further insight into the pathogenesis of T2DM, and thus may contribute to develop better treatment of this condition.
Physiological and biochemical changes during drought and recovery periods at tillering and jointing stages in wheat (Triticum aestivum L.)
Authors: Abid Muhammad , Ali Shafaqat , Qi Lei Kang , Zahoor Rizwan , Tian Zhongwei , Jiang Dong , Snider John L. , Dai Tingbo
Published: March 2018

Defining the metabolic strategies used by wheat to tolerate and recover from drought events will be important for ensuring yield stability in the future, but studies addressing this critical research topic are limited. To this end, the current study quantified the physiological, biochemical, and agronomic responses of a drought tolerant and drought sensitive cultivar to periods of water deficit and recovery. Drought stress caused a reversible decline in leaf water relations, membrane stability, and photosynthetic activity, leading to increased reactive oxygen species (ROS) generation, lipid peroxidation and membrane injury. Plants exhibited osmotic adjustment through the accumulation of soluble sugars, proline, and free amino acids and increased enzymatic and non-enzymatic antioxidant activities. After re-watering, leaf water potential, membrane stability, photosynthetic processes, ROS generation, anti-oxidative activities, lipid peroxidation, and osmotic potential completely recovered for moderately stressed plants and did not fully recover in severely stressed plants. Higher photosynthetic rates during drought and rapid recovery after re-watering produced less-pronounced yield declines in the tolerant cultivar than the sensitive cultivar. These results suggested that the plant’s ability to maintain functions during drought and to rapidly recover after re-watering during vegetative periods are important for determining final productivity in wheat.
Estimating the probability of dengue virus introduction and secondary autochthonous cases in Europe
Authors: Massad Eduardo , Amaku Marcos , Coutinho Francisco Antonio Bezerra , Struchiner Claudio José , Burattini Marcelo Nascimento , Khan Kamran , Liu-Helmersson Jing , Rocklöv Joacim , Kraemer Moritz U. G. , Wilder-Smith Annelies
Published: March 2018

Given the speed of air travel, diseases even with a short viremia such as dengue can be easily exported to dengue naïve areas within 24 hours. We set out to estimate the risk of dengue virus introductions via travelers into Europe and number of secondary autochthonous cases as a result of the introduction. We applied mathematical modeling to estimate the number of dengue-viremic air passengers from 16 dengue-endemic countries to 27 European countries, taking into account the incidence of dengue in the exporting countries, travel volume and the probability of being viremic at the time of travel. Our models estimate a range from zero to 167 air passengers who are dengue-viremic at the time of travel from dengue endemic countries to each of the 27 receiving countries in one year. Germany receives the highest number of imported dengue-viremic air passengers followed by France and the United Kingdom. Our findings estimate 10 autochthonous secondary asymptomatic and symptomatic dengue infections, caused by the expected 124 infected travelers who arrived in Italy in 2012. The risk of onward transmission in Europe is reassuringly low, except where Aedes aegypti is present.
Evolution of Cooperation with Heterogeneous Conditional Cooperators
Authors: Battu Balaraju , Pammi V. S. Chandrasekhar , Srinivasan Narayanan
Published: March 2018

Conditional cooperation declines over time if heterogeneous ideal conditional agents are involved in repeated interactions. With strict assumptions of rationality and a population consisting of ideal conditional agents who strictly follow a decision rule, cooperation is not expected. However, cooperation is commonly observed in human societies. Hence, we propose a novel evolutionary agent-based model where agents rely on social information. Each agent interacts only once either as a donor or as a receiver. In our model, the population consists of either non-ideal or ideal heterogeneous conditional agents. Their donation decisions are stochastically based on the comparison between the number of donations in the group and their conditional cooperative criterion value. Non-ideal agents occasionally cooperate even if the conditional rule of the agent is not satisfied. The stochastic decision and selection rules are controlled with decision intensity and selection intensity, respectively. The simulations show that high levels of cooperation (more than 90%) are established in the population with non-ideal agents for a particular range of parameter values. The emergence of cooperation needs non-ideal agents and a heterogeneous population. The current model differs from existing models by relying on social information and not on individual agent’s prior history of cooperation.
Cryptosporidium oocyst persistence in agricultural streams –a mobile-immobile model framework assessment
Authors: Drummond J. D. , Boano F. , Atwill E. R. , Li X. , Harter T. , Packman A. I.
Published: March 2018

Rivers are a means of rapid and long-distance transmission of pathogenic microorganisms from upstream terrestrial sources. Pathogens enter streams and rivers via overland flow, shallow groundwater discharge, and direct inputs. Of concern is the protozoal parasite,Cryptosporidium, which can remain infective for weeks to months under cool and moist conditions, with the infectious stage (oocysts) largely resistant to chlorination. We applied a mobile-immobile model framework to assessCryptosporidiumtransport and retention in streams, that also accounts for inactivation. The model is applied to California’s Central Valley whereCryptosporidiumexposure can be at higher risk due to agricultural and wildlife nonpoint sources. The results demonstrate that hyporheic exchange is an important process to include in models characterizing pathogen dynamics in streams, delaying downstream transmission and allowing for immobilization processes, such as reversible filtration in the sediments, to occur. Although in-stream concentrations decrease relatively quickly (within hours), pathogen accumulation of up to 66% of the inputs due to immobilization processes in the sediments and slower moving surface water could result in long retention times (months to years). The model appropriately estimates baseflow pathogen accumulation and can help predict the potential loads of resuspended pathogens in response to a storm event.
Zinc knuckle of TAF1 is a DNA binding module critical for TFIID promoter occupancy
Authors: Curran Elizabeth C. , Wang Hui , Hinds Thomas R. , Zheng Ning , Wang Edith H.
Published: March 2018

The general transcription factor IID (TFIID) is the first component of the preinitiation complex (PIC) to bind the core promoter of RNA polymerase II transcribed genes. Despite its critical role in protein-encoded gene expression, how TFIID engages promoter DNA remains elusive. We have previously revealed a winged-helix DNA-binding domain in the N-terminal region of the largest TFIID subunit, TAF1. Here, we report the identification of a second DNA-binding module in the C-terminal half of human TAF1, which is encoded by a previously uncharacterized conserved zinc knuckle domain. We show that the TAF1 zinc knuckle aids in the recruit of TFIID to endogenous promoters vital for cellular proliferation. Mutation of the TAF1 zinc knuckle with defects in DNA binding compromises promoter occupancy of TFIID, which leads to a decrease in transcription and cell viability. Together, our studies provide a foundation to understand how TAF1 plays a central role in TFIID promoter binding and regulation of transcription initiation.
Precise Doppler shift compensation in the hipposiderid bat, Hipposideros armiger
Authors: Schoeppler Diana , Schnitzler Hans-Ulrich , Denzinger Annette
Published: March 2018

Bats of the Rhinolophidae and Hipposideridae families, and Pteronotus parnellii, compensate for Doppler shifts generated by their own flight movement. They adjust their call frequency such that the frequency of echoes coming from ahead fall in a specialized frequency range of the hearing system, the auditory fovea, to evaluate amplitude and frequency modulations in echoes from fluttering prey. Some studies in hipposiderids have suggested a less sophisticated or incomplete Doppler shift compensation. To investigate the precision of Doppler shift compensation in Hipposideros armiger, we recorded the echolocation and flight behaviour of bats flying to a grid, reconstructed the flight path, measured the flight speed, calculated the echo frequency, and compared it with the resting frequency prior to each flight. Within each flight, the average echo frequency was kept constant with a standard deviation of 110 Hz, independent of the flight speed. The resting and reference frequency were coupled with an offset of 80 Hz; however, they varied slightly from flight to flight. The precision of Doppler shift compensation and the offset were similar to that seen in Rhinolophidae and P. parnellii. The described frequency variations may explain why it has been assumed that Doppler shift compensation in hipposiderids is incomplete.
Value of Preoperative Modified Body Mass Index in Predicting Postoperative 1-Year Mortality
Authors: Oh Tak Kyu , Lee Jaebong , Hwang Jung-Won , Do Sang-Hwan , Jeon Young-Tae , Kim Jin Hee , Kim Kooknam , Song In-Ae
Published: March 2018

Serum albumin and conventional BMI (cBMI) are commonly used indices of malnutrition status. Because cBMI does not reflect fluid accumulation, modified body mass index (mBMI, serum albumin × cBMI) is a more accurate measure of malnutrition status. This study investigated the association between preoperative mBMI and postoperative 1-year mortality, in comparison with serum albumin and cBMI. Medical records of 80,969 adult patients who underwent surgical procedures in a tertiary care hospital between 1 January, 2011 and 31 December, 2015 were retrospectively reviewed. Postoperative 1-year mortality increased with reduction in cBMI, mBMI, and albumin separately (P < 0.001). When considering interaction between cBMI and albumin, albumin was the only significant factor of postoperative 1-year mortality [odds ratio: 0.377, 95% confidence interval (0.245–0.579), P < 0.001], while cBMI or interaction (cBMI * albumin) was not significant (P > 0.05). Adjusted area under the curve (AUC) was highest (0.885) in the overall model (cBMI + albumin + cBMI * albumin); adjusted AUC between mBMI and albumin did not differ significantly (P = 0.558). Low albumin is the strongest independent predictor of postoperative 1-year mortality among the three variables (albumin, cBMI, mBMI). Adding cBMI to albumin does not increase the validity of the AUC of albumin.