bluuebunny/crossref_metadata_2025_split huggingface dataset:
Double Irreversibility and Environmental Policy Timing
Authors: POMMERET AUDE , PRIEUR FABIEN 
Published: March 2013

AbstractThe timing of environmental policy typically takes place within a framework in which uncertainty over the future impact of pollution and two different kinds of irreversibilities interact. The first kind of irreversibility concerns the sunk cost of environmental degradation; the second is related to the sunk cost of environmental policy. Clearly, the two irreversibilities pull in opposite directions: policy irreversibility leads to more pollution and a less/later policy, while environmental irreversibility generates less pollution and a more/sooner policy. Using a real option approach and an infinite time horizon model, this paper considers both irreversibilities simultaneously. The model first is developed by paying particular attention to the option values related to pollution and policy adoption. The environmental policy we consider consists in increasing the natural assimilation rate. Solving the model in closed form then provides solutions for both the optimal pollution level and the optimal environmental policy timing. Finally, we provide a numerical example with the purpose of appraising which irreversibility has the prevailing effect and what is the overall impact of both irreversibilities on pollution and policy timing.
Comparing Environmental Policy Instruments Within an Incomplete Contract Framework
Authors: WIRL FRANZ 
Published: March 2013

AbstractThis paper compares three different legal means—no environmental policy (the pollutee pays), full liability (the polluter pays), and pollution standards—to reduce and regulate neighborhood externalities within an incomplete contract framework. It turns out that the relative efficiency of these instruments depends, in general, on details. However, moderate standards are preferable to no environmental policy and tight (but not too tight) standards dominate liability. This provides under the given assumptions (neighborhood externalities, incomplete contracts) a justification for “sensible” standards for three reasons. First, unilateral allocations of property rights are biased that distort allocations even if ex post bargaining takes place. Second, a standard is superior in the following sense: if it is set equal to the outcome under any allocation of rights, it will be improved in the process of ex post bargaining. Third, unilateral property rights encourage strategic ex ante investments up to the point that committing to no bargaining would be beneficial (if possible).
Permanent first molar eruption and caries patterns in American Indian and Alaska Native children: challenging the concept of targeting second grade for school‐based sealant programs
Authors: Phipps Kathy R. , Ricks Timothy L. , Blahut Patrick 
Published: March 2013

AbstractObjectiveTo describe first permanent molar eruption and caries patterns among American Indian and Alaska Native (AI/AN) children in order to identify the appropriate target grade for school‐based sealant programs.MethodsWe used data from the 2011‐2012 Indian Health Service oral health surveillance survey of AI/AN children in kindergarten through third grade. Children were screened by trained examiners. Cavitated lesions were classified as decayed, and teeth with any portion of the crown exposed were considered erupted.ResultsWe screened 15,611 AI/AN children in 186 schools. The percentage with four erupted first molars was 27 percent of kindergarten, 76 percent of first, 96 percent of second, and 99 percent of third‐grade children. About 7 percent of kindergarteners had decayed, missing, or filled molars compared with 20 percent, 30 percent, and 38 percent of first, second, and third graders, respectively.ConclusionSchool‐based sealant programs for AI/AN children should target kindergarten and first grade with follow‐up programs for second‐grade children.
Lipopolysaccharide‐induced indoleamine 2,3‐dioxygenase expression in the periodontal ligament
Authors: Moon J. S. , Cheong N. R. , Yang S. Y. , Kim I. S. , Chung H. J. , Jeong Y. W. , Park J. C. , Kim M. S. , Kim S. H. , Ko H. M. 
Published: March 2013

Background and ObjectiveIndoleamine 2,3‐dioxygenase (IDO) is a tryptophan‐oxidizing enzyme with immune‐inhibitory effects. The aim of this study was to investigate the expression of IDO by lipopolysaccharide (LPS), a component of gram‐negative bacteria, in human periodontal ligament (PDL) cells.Material and MethodsHuman PDL cells and gingival fibroblasts (GFs) were prepared from explants of human PDLs and from gingival tissues of clinically healthy donors, respectively. Real‐time RT‐PCR, western blotting and the IDO enzyme assay were performed to determine the expression of IDO following LPS treatment of cells. LPS was injected into mice tail veins to evaluate the effects of LPS in vivo in the maxillary first molar. Immunofluorescence staining and histological analysis were followed to localize IDO in mouse PDL.ResultsThe level of expression of IDO mRNA in primary human PDL cells after LPS treatment was increased in a dose‐dependent manner, reaching a peak 8 h after LPS treatment. The expression and activities of IDO protein were significantly increased in comparison with those of the control. In addition, the increased production of kynurenine in culture medium was observed 72 h after LPS treatment. In the immunofluorescence findings, stronger immunoreactivities were shown in PDL than in gingival tissues in the maxillae. In accordance with the immunofluorescence findings, LPS treatment induced a strong up‐regulation of IDO mRNA in human PDL cells, whereas human GFs showed only a weak response to LPS.ConclusionThese results clearly show that IDO was induced by LPS in primary human PDL cells, suggesting that PDL might be involved in the regulation of oral inflammatory disease.
Relationship between salivary leukotriene B4 levels and salivary mucin or alveolar bone resorption, in subjects with periodontal health and disease
Authors: Sánchez G. A. , Miozza V. A. , Delgado A. , Busch L. 
Published: March 2013

ObjectiveHere we determine the salivary levels of leukotriene B4 (LTB4) and its relation with salivary mucin and alveolar bone level.BackgroundLTB4 is a membrane‐derived lipid mediator formed from arachidonic acid. It is among the most potent stimulants of polymorphonuclear leukocytes providing the first host defense against infections. Leukotrienes also induce bone resorption. Because LTB4 is present in the oral cavity the aim of the present study was to explore the role of LTB4 in patients with periodontal disease.MethodsEighty‐one subjects were clinically examined and distributed into four groups, namely, clinically healthy, mild, moderate and severe periodontitis, according to periodontal status, classified into values of clinical attachment level and probing pocket depth. Unstimulated saliva was collected for 5 min. Salivary LTB4 was determined by an immune assay method, mucin was determined by a colorimetric method and radiographic assessment used to determine alveolar bone level.ResultsPatients with mild periodontitis showed a decrease in salivary LTB4 levels while patients with severe periodontitis showed increased LTB4 levels. A significant positive correlation was observed between salivary LTB4 and clinical attachment level, salivary mucin concentration or alveolar bone level.ConclusionThe close relation between salivary LTB4 and mucin levels suggested that LTB4 might be involved in the defense mechanism of the oral cavity. The correlation of LTB4 with the alveolar bone level indicates that they are one of the mediators responsible for bone resorption.
Oxidative burst intensity of peripheral phagocytic cells and periodontitis in Down syndrome
Authors: Khocht A. , Russell B. , Cannon J. G. , Turner B. , Janal M. 
Published: March 2013

BackgroundThis study investigated the oxidative burst function of peripheral phagocytic cells (granulocytes and monocytes) and assessed the relation between oxidative burst and periodontal status in adult individuals with Down syndrome (DS) vs. other groups.MethodsOf 55 DS individuals (18–56 years old), 74 individuals with mental retardation (MR) and 88 medically healthy controls (HC) participated in the study. The MR and HC groups were age, race and gender matched with the DS group. Gingival index, plaque index, probing depth, attachment level and bleeding on probing were recorded for each subject. Whole blood was collected for granulocyte/monocyte oxidative burst tests. Oxidative burst was determined by flow cytometry in terms of percentage of cells actively involved in oxidative burst, and oxidative intensity (magnitude of ROIs per cell).ResultsThe basal oxidative burst intensity of DS granulocytes was higher than that of HC and MR granulocytes (p = 0.05). The Escherichia coli stimulated oxidative burst intensity of DS monocytes was higher than that of HC and MR monocytes (p = 0.05). Regression analysis controlling for age, sex, race and plaque levels showed a significant association between monocyte oxidative burst intensity and loss of periodontal attachment in DS subjects (p < 0.01). Regression analysis also showed a significant association between granulocyte oxidative burst intensity and bleeding on probing in all subjects (p < 0.05).ConclusionsOxidative burst activity of peripheral monocytes and granulocytes is elevated in DS affected individuals and may contribute to periodontal tissue inflammation and loss of periodontal attachment in this susceptible group.
Patient Safety Perspectives of Providers and Nurses: The Experience of a Rural Ambulatory Care Practice Using an EHR With E‐prescribing
Authors: Bramble James D. , Abbott Amy A. , Fuji Kevin T. , Paschal Karen A. , Siracuse Mark V. , Galt Kimberly 
Published: March 2013

AbstractPurposeThe purpose of this study was to identify and describe safety improvements and concerns indicated by providers and nurses in a rural community ambulatory care practice using an electronic health record with an e‐prescribing feature (EHR with eRx).MethodsTwo focus groups were conducted; 1 with providers and the other with nurses. Participants responded to questions and discussed their perceptions of safety improvements and concerns with use of an EHR with eRx. Transcripts were analyzed using sequential and continuous analytic methods.FindingsThree themes centered on efficiency and patient safety emerged from data analysis: (1) EHR with eRx adoption has led to new improvements and concerns for patient safety, (2) the EHR with eRx has affected efficiency in the clinic, and (3) EHR with eRx adoption has led to workarounds.ConclusionsConcerns remain among providers and nurses regarding the use of EHR with eRx applications, although concerns differed between groups. Therefore, When EHR improvements are planned, it is important to consider the differing needs of the professionals who deliver care.
Prevalence of and Factors Associated With Subclinical Posttraumatic Stress Symptoms and PTSD in Urban and Rural Areas of Montana: A Cross‐Sectional Study
Authors: Erickson Lance D. , Hedges Dawson W. , Call Vaughn R. A. , Bair Byron 
Published: March 2013

AbstractPurposePosttraumatic stress disorder (PTSD) is an important clinical problem, but little is known about PTSD in rural, nonclinical populations. To better understand PTSD in rural areas, we examined the prevalence and risk and protective factors in urban, rural, and highly rural communities in Montana for both subclinical posttraumatic stress symptoms (PTSS) and PTSD.MethodsWe compared the prevalence of PTSS and PTSD in urban, rural, and highly rural communities in bivariate and multivariable regression analyses using self‐reported cross‐sectional survey data from the Montana Health Matters study (N = 3,512), a state‐representative household‐based survey done in 2010‐2011. We also explore potential risk and protective factors for PTSS and PTSD and whether risk and protective factors for each differ by rurality.FindingsThere were no differences in the level of PTSS by rurality in bivariate or multivariate models, and the bivariate relationship between rurality and PTSD became nonsignificant in a multivariate model. Only locus of control was predictive for PTSS; however, gender, age, marital status, income, employment status, community fit, locus of control, and religiosity were associated with PTSD. Some risk and protective factors operate differently by rurality.ConclusionsAlthough our findings are subject to weaknesses common to cross‐sectional data and are based on questionnaire reports, it appears that there are different risk and protective factors for PTSS and PTSD, suggesting that PTSD may be qualitatively different from PTSS. Furthermore, differences in risk and protective factors across urban and rural communities suggest more attention is needed to understand PTSD in rural communities.
Biogeographic deconstruction of alpine plant communities along altitudinal and topographic gradients
Authors: Jiménez‐Alfaro Borja , Marcenó Corrado , Bueno Álvaro , Gavilán Rosario , Obeso José Ramón 
Published: March 2013

AbstractQuestionsAre species from different biogeographic groups (mediterranean, alpine and endemic) filtered in different ways by altitude and topography in alpine plant communities? What is the relative performance of these environmental factors at predicting the species diversity of the communities as a whole and of the geographic species groups?LocationPicos deEuropa,CantabrianRange (Spain).MethodsWe sampled the presence and cover of vascular plants in 5‐m radius plots on alpine grasslands between 1900 and 2500 m a.s.l. FiveGIS‐based terrain variables at 15 m × 15 m were used to model species richness and cover per plot using generalized and linear models, and the variation in species composition with redundancy analysis. The same analyses were repeated for the whole data set and for subsets of species from alpine, mediterranean and endemic distributions.ResultsThe influence of altitude and topography on species richness, cover and composition differed for the whole data set and for the geographic species groups. Altitude was the main variable affecting floristic diversity in the communities as a whole, but the separate species groups were more influenced by slope, topographic wetness index and solar radiation. Richness and cover of mediterranean species showed the strongest relationships with topography. Alpine and endemic species showed relationships with topography for species cover and composition, but not for species richness.ConclusionsIn alpine landscapes, biogeographic deconstruction of the species pool can provide a better understanding of the influence of altitude and topography on local communities than analysis of the entire community alone. Furthermore, the strong influence of local topography on species groups improves our understanding of how alpine species will respond to climate change.
The arrestin‐like protein ArtA is essential for ubiquitination and endocytosis of the UapA transporter in response to both broad‐range and specific signals
Authors: Karachaliou Mayia , Amillis Sotiris , Evangelinos Minoas , Kokotos Alexandros C. , Yalelis Vassilis , Diallinas George 
Published: March 2013

SummaryWe investigated the role of all arrestin‐like proteins of Aspergillus nidulans in respect to growth, morphology, sensitivity to drugs and specifically for the endocytosis and turnover of the uric acid‐xanthine transporter UapA. A single arrestin‐like protein, ArtA, is essential for HulARsp5‐dependent ubiquitination and endocytosis of UapA in response to ammonium or substrates. Mutational analysis showed that residues 545–563 of the UapA C‐terminal region are required for efficient UapA endocytosis, whereas the N‐terminal region (residues 2–123) and both PPxY motives are essential for ArtA function. We further show that ArtA undergoes HulA‐dependent ubiquitination at residue Lys‐343 and that this modification is critical for UapA ubiquitination and endocytosis. Lastly, we show that ArtA is essential for vacuolar turnover of transporters specific for purines (AzgA) or l‐proline (PrnB), but not for an aspartate/glutamate transporter (AgtA). Our results are discussed within the frame of recently proposed mechanisms on how arrestin‐like proteins are activated and recruited for ubiquitination of transporters in response to broad range signals, but also put the basis for understanding how arrestin‐like proteins, such as ArtA, regulate the turnover of a specific transporter in the presence of its substrates.
A complex of YlbF, YmcA and YaaT regulates sporulation, competence and biofilm formation by accelerating the phosphorylation of Spo0A
Authors: Carabetta Valerie J. , Tanner Andrew W. , Greco Todd M. , Defrancesco Melissa , Cristea Ileana M. , Dubnau David 
Published: March 2013

SummaryBacillus subtilis has adopted a bet‐hedging strategy to ensure survival in changing environments. From a clonal population, numerous sub‐populations can emerge, expressing different sets of genes that govern the developmental processes of sporulation, competence and biofilm formation. The master transcriptional regulator Spo0A controls the entry into all three fates and the production of the phosphorylated active form of Spo0A is precisely regulated via a phosphorelay, involving at least four proteins. Two proteins, YmcA and YlbF were previously shown to play an unidentified role in the regulation of biofilm formation, and in addition, YlbF was shown to regulate competence and sporulation. Using an unbiased proteomics screen, we demonstrate that YmcA and YlbF interact with a third protein, YaaT to form a tripartite complex. We show that all three proteins are required for proper establishment of the three above‐mentioned developmental states. We show that the complex regulates the activity of Spo0A in vivo and, using in vitro reconstitution experiments, determine that they stimulate the phosphorelay, probably by interacting with Spo0F and Spo0B. We propose that the YmcA–YlbF–YaaT ternary complex is required to increase Spo0A~P levels above the thresholds needed to induce development.
Structural characterization of 2,6‐dichloro‐p‐hydroquinone 1,2‐dioxygenase (PcpA) from Sphingobium chlorophenolicum, a new type of aromatic ring‐cleavage enzyme
Authors: Hayes Robert P. , Green Abigail R. , Nissen Mark S. , Lewis Kevin M. , Xun Luying , Kang ChulHee 
Published: March 2013

SummaryPcpA (2,6‐dichloro‐p‐hydroquinone 1,2‐dioxygenase) from Sphingobium chlorophenolicum, a non‐haem Fe(II) dioxygenase capable of cleaving the aromatic ring of p‐hydroquinone and its substituted variants, is a member of the recently discovered p‐hydroquinone 1,2‐dioxygenases. Here we report the 2.6 Å structure of PcpA, which consists of four βαβββ motifs, a hallmark of the vicinal oxygen chelate superfamily. The secondary co‐ordination sphere of the Fe(II) centre forms an extensive hydrogen‐bonding network with three solvent exposed residues, linking the catalytic Fe(II) to solvent. A tight hydrophobic pocket provides p‐hydroquinones access to the Fe(II) centre. The p‐hydroxyl group is essential for the substrate‐binding, thus phenols and catechols, lacking a p‐hydroxyl group, do not bind to PcpA. Site‐directed mutagenesis and kinetic analysis confirm the critical catalytic role played by the highly conserved His10, Thr13, His226 and Arg259. Based on these results, we propose a general reaction mechanism for p‐hydroquinone 1,2‐dioxygenases.
Robust inducible Cre recombinase activity in the human malaria parasite Plasmodium falciparum enables efficient gene deletion within a single asexual erythrocytic growth cycle
Authors: Collins Christine R. , Das Sujaan , Wong Eleanor H. , Andenmatten Nicole , Stallmach Robert , Hackett Fiona , Herman Jean‐Paul , Müller Sylke , Meissner Markus , Blackman Michael J. 
Published: March 2013

SummaryAsexual blood stages of the malaria parasite, which cause all the pathology associated with malaria, can readily be genetically modified by homologous recombination, enabling the functional study of parasite genes that are not essential in this part of the life cycle. However, no widely applicable method for conditional mutagenesis of essential asexual blood‐stage malarial genes is available, hindering their functional analysis. We report the application of the DiCre conditional recombinase system to Plasmodium falciparum, the causative agent of the most dangerous form of malaria. We show that DiCre can be used to obtain rapid, highly regulated site‐specific recombination in P. falciparum, capable of excising loxP‐flanked sequences from a genomic locus with close to 100% efficiency within the time‐span of a single erythrocytic growth cycle. DiCre‐mediated deletion of the SERA5 3' UTR failed to reduce expression of the gene due to the existence of alternative cryptic polyadenylation sites within the modified locus. However, we successfully used the system to recycle the most widely used drug resistance marker for P. falciparum, human dihydrofolate reductase, in the process producing constitutively DiCre‐expressing P. falciparum clones that have broad utility for the functional analysis of essential asexual blood‐stage parasite genes.
Transcriptomic analysis of metabolic function in the giant kelp, Macrocystis pyrifera, across depth and season
Authors: Konotchick Talina , Dupont Christopher L. , Valas Ruben E. , Badger Jonathan H. , Allen Andrew E. 
Published: March 2013

Summary

To increase knowledge of transcript diversity for the giant kelp, Macrocystis pyrifera, and assess gene expression across naturally occurring depth gradients in light, temperature and nutrients, we sequenced four cDNA libraries created from blades collected at the sea surface and at 18 m depth during the winter and summer.

Comparative genomics cluster analyses revealed novel gene families (clusters) in existing brown alga expressed sequence tag data compared with other related algal groups, a pattern also seen with the addition of M. pyrifera sequences.

Assembly of 228 Mbp of sequence generated c. 9000 isotigs and c. 12 000 open reading frames. Annotations were assigned using families of hidden Markov models for c. 11% of open reading frames; M. pyrifera had highest similarity to other members of the Phaeophyceae, namely Ectocarpus siliculosus and Laminaria digitata.

Quantitative polymerase chain reaction of transcript targets verified depth‐related differences in gene expression; stress response and light‐harvesting transcripts, especially members of the LI818 (also known as LHCSR) family, showed high expression in the surface compared with 18 m depth, while some nitrogen acquisition transcripts (e.g. nitrite reductase) were upregulated at depth compared with the surface, supporting a conceptual biological model of depth‐dependent physiology.