bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ethylene – and oxygen signalling – drive plant survival during flooding
Authors: Voesenek L. A. C. J. , Sasidharan R. 
Published: April 2013

AbstractFlooding is a widely occurring environmental stress both for natural and cultivated plant species. The primary problems associated with flooding arise due to restricted gas diffusion underwater. This hampers gas exchange needed for the critical processes of photosynthesis and respiration. Plant acclimation to flooding includes the adaptation of a suite of traits that helps alleviate or avoid these stressful conditions and improves or restores exchange of O2 and CO2. The manifestation of these traits is, however, reliant on the timely perception of signals that convey the underwater status. Flooding‐associated reduced gas diffusion imposes a drastic change in the internal gas composition within submerged plant organs. One of the earliest changes is an increase in the levels of the gaseous plant hormone ethylene. Depending on the species, organ, flooding conditions and time of the day, plants will also subsequently experience a reduction in oxygen levels. This review provides a comprehensive overview on the roles of ethylene and oxygen as critical signals of flooding stress. It includes a discussion of the dynamics of these gases in plants when underwater, their interaction, current knowledge of their perception mechanisms and the resulting downstream changes that mediate important acclimative processes that allow endurance and survival under flooded conditions.
Impact of early and late winter icing events on sub‐arctic dwarf shrubs
Authors: Preece C. , Phoenix G. K. 
Published: April 2013

AbstractPolar regions are predicted to undergo large increases in winter temperature and an increased frequency of freeze–thaw cycles, which can cause ice layers in the snow pack and ice encasement of vegetation. Early or late winter timing of ice encasement could, however, modify the extent of damage caused to plants. To determine impacts of the date of ice encasement, a novel field experiment was established in sub‐arctic Sweden, with icing events simulated in January and March 2008 and 2009. In the subsequent summers, reproduction, phenology, growth and mortality, as well as physiological indicators of leaf damage were measured in the three dominant dwarf shrubs: Vaccinium uliginosum, Vaccinium vitis‐idaea and Empetrum nigrum. It was hypothesised that January icing would be more damaging compared to March icing due to the longer duration of ice encasement. Following 2 years of icing, E. nigrum berry production was 83% lower in January‐iced plots compared to controls, and V. vitis‐idaea electrolyte leakage was increased by 69%. Conversely, electrolyte leakage of E. nigrum was 25% lower and leaf emergence of V. vitis‐idaea commenced 11 days earlier in March‐iced plots compared to control plots in 2009. There was no effect of icing on any of the other parameters measured, indicating that overall these study species have moderate to high tolerance to ice encasement. Even much longer exposure under the January icing treatment does not clearly increase damage.
Differential response of antioxidative systems of maize (Zea mays L.) roots cell walls to osmotic and heavy metal stress
Authors: Vuletić M. , Hadži‐Tašković Šukalović V. , Marković K. , Kravić N. , Vučinić Ž. , Maksimović V. 
Published: April 2013

AbstractAn analysis of peroxidase and ascorbate oxidase activity, phenolic content and antioxidant capacity of isolated maize root cell walls was performed in controls and plants stressed with polyethylene glycol (PEG) or heavy metals, zinc or copper. Peroxidase activity (oxidative and peroxidative) was more pronounced in the ionic than in the covalent cell wall fraction. PEG induced an increase and Zn2+ a decrease of both ionically bound peroxidase activities. In the covalent fraction, Cu2+ decreased oxidative and increased peroxidative activity of peroxidase. Isoelectric focusing of ionically bound proteins and activity staining for peroxidase demonstrated increased intensities and appearance of new acidic isoforms, especially in Zn2+ and PEG treatments. Most pronounced basic isoforms (pI ~ 7.5) in controls, decreased in intensity or completely disappeared in stressed plants. Ascorbate oxidase activity was significantly increased by PEG and decreased by Zn2+ treatments, and highly correlated with peroxidase activity. Antioxidant capacity and total phenolics content increased in heavy metal‐treated and decreased in PEG‐treated plants. Analysis of individual phenolic components revealed p‐coumaric and ferulic acids, as the most abundant, as well as ferulic acid dimers, trimers and tetramers in the cell walls; their quantity increased under stress conditions. Results presented demonstrate the existence of diverse mechanisms of plant response to different stresses.
Cell Phone Exposures and Hearing Loss in Children in the Danish National Birth Cohort
Authors: Sudan Madhuri , Kheifets Leeka , Arah Onyebuchi A. , Olsen Jorn 
Published: April 2013

AbstractBackgroundChildren today are exposed to cell phones early in life, and may be the most vulnerable if exposure is harmful to health. We investigated the association between cell phone use and hearing loss in children.MethodsThe Danish National Birth Cohort (DNBC) enrolled pregnant women between 1996 and 2002. Detailed interviews were conducted during gestation, and when the children were 6 months, 18 months and 7 years of age. We used multivariable‐adjusted logistic regression, marginal structural models (MSM) with inverse‐probability weighting, and doubly robust estimation (DRE) to relate hearing loss at age 18 months to cell phone use at age 7 years, and to investigate cell phone use reported at age 7 in relation to hearing loss at age 7.ResultsOur analyses included data from 52 680 children. We observed weak associations between cell phone use and hearing loss at age 7, with odds ratios and 95% confidence intervals from the traditional logistic regression, MSM and DRE models being 1.21 [95% confidence interval [CI] 0.99, 1.46], 1.23 [95% CI 1.01, 1.49] and 1.22 [95% CI 1.00, 1.49], respectively.ConclusionsOur findings could have been affected by various biases and are not sufficient to conclude that cell phone exposures have an effect on hearing. This is the first large‐scale epidemiologic study to investigate this potentially important association among children, and replication of these findings is needed.
Smoking during Pregnancy and Risk of Autism Spectrum Disorder in a Finnish National Birth Cohort
Authors: Tran Phuong Lien , Lehti Venla , Lampi Katja M. , Helenius Hans , Suominen Auli , Gissler Mika , Brown Alan S. , Sourander Andre 
Published: April 2013

AbstractBackgroundResults of previous population‐based studies examining associations between smoking during pregnancy and autism spectrum disorders (ASD) are contradictory. Furthermore, there is a lack of population‐based studies examining the relationship between smoking during pregnancy and the main diagnostic subtypes of ASD.MethodsWe conducted a population‐based nested case–control study based on the Finnish Prenatal Study of Autism (FIPS‐A) among liveborn infants delivered in Finland between 1987 and 2005. Data on maternal smoking during pregnancy were available from the Finnish Medical Birth Register (FMBR) since October 1990. Data on ASD in the offspring were obtained from the Finnish Hospital Discharge Register (FHDR).ResultsAmong the three subtypes of ASD, maternal smoking during the whole pregnancy was associated with an increased risk of pervasive developmental disorder (PDD) (odds ratio 1.2, 95% confidence interval 1.0, 1.5). The increase in odds persisted after controlling for maternal age, mother's socio‐economic and psychiatric status, and infant's weight for gestational age. However, smoking exposure limited to the first trimester was not associated with PDD or any of the other ASD subtypes.ConclusionsMaternal smoking is related to a modest increase in risk of PDD, while no associations were observed for childhood autism and Asperger's syndrome.
Maternal Smoking During Pregnancy and Failure of the Georgia First Grade Criterion‐Referenced Competency Test
Authors: Feng Jia , Kramer Michael R. , Dever Bridget V. , Dunlop Anne L. , Williams Bryan , Jain Lucky 
Published: April 2013

AbstractBackgroundMaternal smoking during pregnancy (MSDP) has been reported to be associated with impaired measures of cognitive function, but it remains unclear whether exposure to MSDP has an impact upon offspring school performance. We examined the association between MSDP and failure of the Criterion‐Referenced Competency Tests (CRCT) among Georgia first grade students.MethodsA retrospective cohort was created by deterministically linking 331 531 children born in Georgia from 1998 to 2002 (inclusive) to their individual CRCT education records from 2005 to 2009. We evaluated the association between MSDP (yes/no) and failure of the CRCT Reading, English/Language Arts (ELA), and Mathematics tests, with adjustment for maternal and child sociodemographic characteristics and birth outcomes. Log‐binomial models estimated the risk ratios and 95% confidence intervals. Conditional models were fitted to paired sibling data.ResultsMSDP was associated with CRCT failure with an adjusted risk ratios for Reading: 1.16 [95% CI 1.12, 1.21]; ELA: 1.12 [95%CI 1.10, 1.15]; and Mathematics: 1.13 [95%CI 1.10, 1.16]. The association remained significant in paired sibling analyses.ConclusionsMSDP may have independent long‐term effects on offspring school performance, which does not appear to be through smoking‐related adverse birth outcomes.
Direct and Proxy Recall of Childhood Socio‐Economic Position and Health
Authors: Straughen Jennifer K. , Caldwell Cleopatra H. , Osypuk Theresa L. , Helmkamp Laura , Misra Dawn P. 
Published: April 2013

AbstractBackgroundThe utility of proxy reporting within the life course framework has not been adequately assessed; therefore we sought to assess the magnitude and type of agreement that exists between index and proxy reports for bodyweight, health, and socio‐economic position (SEP) in childhood.MethodsParticipants were enrolled as part of an ongoing study of preterm birth in African American women in Metro Detroit. Post‐partum women and their mothers (n = 333 pairs) provided retrospective reports about the woman's childhood bodyweight, health, and SEP. Agreement was assessed using kappa, weighted kappa (κ), and intraclass correlation coefficients (ICC). Log‐linear models were used to describe the pattern of agreement for ordinal data.ResultsBirthweight and weight at age 18 was reported with a high level of agreement (ICC = 0.86 and 0.71, respectively). Kappa indicated moderate agreement for early and late childhood/adolescent weight. Log‐linear models suggested that there was diagonal agreement plus linear by linear association for early childhood weight and linear by linear association in late childhood/adolescence. Reports of childhood medical problems and hospitalisations had only moderate agreement. Agreement for SEP in both early (κ = 0.14) and late childhood/adolescence (κ = 0.20) was poor. Log‐linear models suggest a linear by linear association, indicating a positive association between the responses.ConclusionsResults suggest that proxy reports may be utilised in conjunction with an index report to provide an estimate of the accuracy of report or to more fully capture experiences over the life course. This may be particularly useful when multiple developmental periods are examined.
Pregnancy Recruitment for Population Research: the National Children's Study Vanguard Experience in Wayne County, Michigan
Authors: Kerver Jean M. , Elliott Michael R. , Norman Gwendolyn S. , Sokol Robert J. , Keating Daniel P. , Copeland Glenn E. , Johnson Christine C. , Cislo Kendall K. , Alcser Kirsten H. , Kruger‐Ndiaye Shonda R. , Pennell Beth‐Ellen , Mehta Shobha , Joseph Christine L. M. , Paneth Nigel ,   MANCS Executive Committee
Published: April 2013

AbstractBackgroundTo obtain a probability sample of pregnancies, the National Children's Study conducted door‐to‐door recruitment in randomly selected neighbourhoods in randomly selected counties in 2009–10. In 2011, an experiment was conducted in 10 US counties, in which the two‐stage geographic sample was maintained, but participants were recruited in prenatal care provider offices. We describe our experience recruiting pregnant women this way in Wayne County, Michigan, a county where geographically eligible women attended 147 prenatal care settings, and comprised just 2% of total county pregnancies.MethodsAfter screening for address eligibility in prenatal care offices, we used a three‐part recruitment process: (1) providers obtained permission for us to contact eligible patients, (2) clinical research staff described the study to women in clinical settings, and (3) survey research staff visited the home to consent and interview eligible women.ResultsWe screened 34 065 addresses in 67 provider settings to find 215 eligible women. Providers obtained permission for research contact from 81.4% of eligible women, of whom 92.5% agreed to a home visit. All home‐visited women consented, giving a net enrolment of 75%. From birth certificates, we estimate that 30% of eligible county pregnancies were enrolled, reaching 40–50% in the final recruitment months.ConclusionsWe recruited a high fraction of pregnancies identified in a broad cross‐section of provider offices. Nonetheless, because of time and resource constraints, we could enrol only a fraction of geographically eligible pregnancies. Our experience suggests that the probability sampling of pregnancies for research could be more efficiently achieved through sampling of providers rather than households.
Is Sweden Being Torn Apart? Privatization and Old and New Patterns of Welfare State Support
Authors: Edlund Jonas , Johansson Sevä Ingemar 
Published: April 2013

AbstractThis article examines the potential impact of institutional change on popular welfare support. The encompassing welfare state of Sweden provides an interesting case where the privatization of social service delivery has been widespread over the last decades. We use survey data from five rounds of the Swedish Welfare State Survey (1992, 1997, 2002, 2006 and 2010) in order to study how public preferences for the financing and organization of welfare services have changed over time. Based on a theory describing an ideal‐typical pattern of public support for an encompassing welfare model, we derive three types of public preferences: support for a pure state model, a pure market model and a mixed model (welfare services are funded by taxes but provided by private firms). We begin by tracking the development of these ideal‐typical attitude patterns between 1992 and 2010. We then investigate how preference patterns vary across municipalities displaying different degrees of privatization of social service delivery. Our results show that welfare support among Swedes over the last decades is better characterized as dynamic rather than stable. Swedes seem to take an overall more ideologically based position on the role of the welfare state over time. The share of respondents expressing such ideologically based preferences has increased from 54 per cent in 1992 to 78 per cent in 2010. This change is principally manifested in increased support for the state and mixed models. This trend seems to be parallel to the increasing share of private welfare service providers over the last decade. We also find a link between the municipal degree of privatization and support for our three ideal‐typical welfare models. Public support for a mixed welfare model and, to some extent, a market model, is comparatively stronger in municipalities where welfare services to a large extent are carried out by private actors. Conversely, data shows that public support for the traditional Swedish state model is more widespread in municipalities having a low degree of welfare services privatization. Lastly, we discuss some theoretical implications of our findings.
Achieving Democratic Leadership: A Data‐Mined Prescription
Authors: Jurek Steven J. , Scime Anthony 
Published: April 2013

ObjectiveTo understand what kind of individuals lead particular regimes, this study examines the most influential people in politics, the executives, to uncover the relationship between their characteristics and the type of regime they govern.MethodsThis article employs data mining with characteristics of executives worldwide against the state's Freedom House ranking.ResultsThrough data mining, the results indicate that while there are still many important factors that coincide with democracy, the length of time in office and to a lesser extent the religious beliefs of executives and the likelihood of being classified as a democracy are heavily related.ConclusionThis article concludes with a recommendation for supporting specific types of executives to increase the likelihood for successful democratization to minimize authoritarian rule.
Feasibility study on inverse four‐dimensional dose reconstruction using the continuous dose‐image of EPID
Authors: Yeo Inhwan Jason , Jung Jae Won , Yi Byong Yong , Kim Jong Oh 
Published: April 2013

Purpose:When an intensity‐modulated radiation beam is delivered to a moving target, the interplay effect between dynamic beam delivery and the target motion due to miss‐synchronization can cause unpredictable dose delivery. The portal dose image in electronic portal imaging device (EPID) represents radiation attenuated and scattered through target media. Thus, it may possess information about delivered radiation to the target. Using a continuous scan (cine) mode of EPID, which provides temporal dose images related to target and beam movements, the authors’ goal is to perform four‐dimensional (4D) dose reconstruction.Methods:To evaluate this hypothesis, first, the authors have derived and subsequently validated a fast method of dose reconstruction based on virtual beamlet calculations of dose responses using a test intensity‐modulated beam. This method was necessary for processing a large number of EPID images pertinent for four‐dimensional reconstruction. Second, cine mode acquisition after summation over all images was validated through comparison with integration mode acquisition on EPID (IAS3 and aS1000) for the test beam. This was to confirm the agreement of the cine mode with the integrated mode, specifically for the test beam, which is an accepted mode of image acquisition for dosimetry with EPID. Third, in‐phantom film and exit EPID dosimetry was performed on a moving platform using the same beam. Heterogeneous as well as homogeneous phantoms were used. The cine images were temporally sorted at 10% interval. The authors have performed dose reconstruction to the in‐phantom plane from the sorted cine images using the above validated method of dose reconstruction. The reconstructed dose from each cine image was summed to compose a total reconstructed dose from the test beam delivery, and was compared with film measurements.Results:The new method of dose reconstruction was validated showing greater than 95.3% pass rates of the gamma test with the criteria of dose difference of 3% and distance to agreement of 3 mm. The dose comparison of the reconstructed dose with the measured dose for the two phantoms showed pass rates higher than 96.4% given the same criteria.Conclusions:Feasibility of 4D dose reconstruction was successfully demonstrated in this study. The 4D dose reconstruction demonstrated in this study can be a promising dose validation method for radiation delivery on moving organs.
Wnt Modulating Agents Inhibit Human Cytomegalovirus Replication
Authors: Kapoor Arun , He Ran , Venkatadri Rajkumar , Forman Michael , Arav-Boger Ravit 
Published: April 2013

ABSTRACT

Infection with human cytomegalovirus (HCMV) continues to be a threat for pregnant women and immunocompromised hosts. Although limited anti-HCMV therapies are available, development of new agents is desired. The Wnt signaling pathway plays a critical role in embryonic and cancer stem cell development and is targeted by gammaherpesviruses, Epstein-Barr virus (EBV), and Kaposi's sarcoma-associated herpesvirus (KSHV). HCMV infects stem cells, including neural progenitor cells, during embryogenesis. To investigate the role of Wnt in HCMV replication
in vitro
, we tested monensin, nigericin, and salinomycin, compounds that inhibit cancer stem cell growth by modulating the Wnt pathway. These compounds inhibited the replication of HCMV Towne and a clinical isolate. Inhibition occurred prior to DNA replication but persisted throughout the full replication cycle. There was a significant decrease in expression of IE2, UL44, and pp65 proteins. HCMV infection resulted in a significant and sustained decrease in expression of phosphorylated and total lipoprotein receptor-related protein 6 (pLRP6 and LRP6, respectively), Wnt 5a/b, and β-catenin and a modest decrease in Dvl2/3, while levels of the negative regulator axin 1 were increased. Nigericin decreased the expression of pLRP6, LRP6, axin 1, and Wnt 5a/b in noninfected and HCMV-infected cells. For all three compounds, a correlation was found between expression levels of Wnt 5a/b and axin 1 and HCMV inhibition. The decrease in Wnt 5a/b and axin 1 expression was more significant in HCMV-infected cells than noninfected cells. These data illustrate the complex effects of HCMV on the Wnt pathway and the fine balance between Wnt and HCMV, resulting in abrogation of HCMV replication. Additional studies are required to elucidate how HCMV targets Wnt for its benefit.
A Combined Pharmacodynamic Quantitative and Qualitative Model Reveals the Potent Activity of Daptomycin and Delafloxacin against Staphylococcus aureus Biofilms
Authors: Bauer Julia , Siala Wafi , Tulkens Paul M. , Van Bambeke Françoise 
Published: April 2013

ABSTRACT

Biofilms are associated with persistence of
Staphylococcus aureus
infections and therapeutic failures. Our aim was to set up a pharmacodynamic model comparing antibiotic activities against biofilms and examining in parallel their effects on viability and biofilm mass. Biofilms of
S. aureus
ATCC 25923 (methicillin-sensitive
S. aureus
[MSSA]) or ATCC 33591 (methicillin-resistant
S. aureus
[MRSA]) were obtained by culture in 96-well plates for 6 h/24 h. Antibiotic activities were assessed after 24/48 h of exposure to concentrations ranging from 0.5 to 512 times the MIC. Biofilm mass and bacterial viability were quantified using crystal violet and the redox indicator resazurin. Biofilms stained with Live/Dead probes were observed by using confocal microscopy. Concentration-effect curves fitted sigmoidal regressions, with a 50% reduction toward both matrix and viability obtained at sub-MIC or low multiples of MICs against young biofilms for all antibiotics tested. Against mature biofilms, maximal efficacies and potencies were reduced, with none of the antibiotics being able to completely destroy the matrix. Delafloxacin and daptomycin were the most potent, reducing viability by more than 50% at clinically achievable concentrations against both strains, as well as reducing biofilm depth, as observed in confocal microscopy. Rifampin, tigecycline, and moxifloxacin were effective against mature MRSA biofilms, while oxacillin demonstrated activity against MSSA. Fusidic acid, vancomycin, and linezolid were less potent overall. Antibiotic activity depends on biofilm maturity and bacterial strain. The pharmacodynamic model developed allows ranking of antibiotics with respect to efficacy and potency at clinically achievable concentrations and highlights the potential utility of daptomycin and delafloxacin for the treatment of biofilm-related infections.