117 research outputs found

    Geographic variations in a model of physician treatment choice with social interactions

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    Location-specific norms of behavior are a widespread phenomenon. In the case of medical practice, numerous studies have found that geographic location exerts a strong influence on the choice of treatments and procedures. This paper shows how the presence of social influence on treatment decisions can help to explain this phenomenon. We construct a theoretical model in which physicians' treatment choices depend on atients' characteristics and on the recent choices of nearby peerseither because there are local knowledge spillovers or because physicians want to conform to local practice patterns. In our model, regional differences in the patient mix give rise to geographically divergent treatment patternsthe treatment a patient receives depends on where she lives. Investigation of Florida data reveals significant geographic variation in treatment rates consistent with the predictions of our model. Implications for patient welfare are explored

    DORN1/P2K1 and purino-calcium signalling in plants: making waves with extracellular ATP.

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    BACKGROUND AND AIMS:Extracellular ATP governs a range of plant functions, including cell viability, adaptation and cross-kingdom interactions. Key functions of extracellular ATP in leaves and roots may involve an increase in cytosolic free calcium as a second messenger ('calcium signature'). The main aim here was to determine to what extent leaf and root calcium responses require the DORN1/P2K1 extracellular ATP receptor in Arabidopsis thaliana. The second aim was to test whether extracellular ATP can generate a calcium wave in the root. METHODS:Leaf and root responses to extracellular ATP were reviewed for their possible links to calcium signalling and DORN1/P2K1. Leaves and roots of wild type and dorn1 plants were tested for cytosolic calcium increase in response to ATP, using aequorin. The spatial abundance of DORN1/P2K1 in the root was estimated using green fluorescent protein. Wild type roots expressing GCaMP3 were used to determine the spatial variation of cytosolic calcium increase in response to extracellular ATP. KEY RESULTS:Leaf and root ATP-induced calcium signatures differed markedly. The leaf signature was only partially dependent on DORN1/P2K1, while the root signature was fully dependent. The distribution of DORN1/P2K1 in the root supports a key role in the generation of the apical calcium signature. Root apical and sub-apical calcium signatures may operate independently of each other but an apical calcium increase can drive a sub-apical increase, consistent with a calcium wave. CONCLUSION:DORN1 could underpin several calcium-related responses but it may not be the only receptor for extracellular ATP in Arabidopsis. The root has the capacity for a calcium wave, triggered by extracellular ATP at the apex

    Arabidopsis thaliana CYCLIC NUCLEOTIDE-GATED CHANNEL2 mediates extracellular ATP signal transduction in root epidermis.

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    Funder: Agence Nationale de la Recherche; Id: http://dx.doi.org/10.13039/501100001665Funder: Canadian Network for Research and Innovation in Machining Technology, Natural Sciences and Engineering Research Council of Canada; Id: http://dx.doi.org/10.13039/501100002790Damage can be signalled by extracellular ATP (eATP) using plasma membrane (PM) receptors to effect cytosolic free calcium ion ([Ca2+ ]cyt ) increase as a second messenger. The downstream PM Ca2+ channels remain enigmatic. Here, the Arabidopsis thaliana Ca2+ channel subunit CYCLIC NUCLEOTIDE-GATED CHANNEL2 (CNGC2) was identified as a critical component linking eATP receptors to downstream [Ca2+ ]cyt signalling in roots. Extracellular ATP-induced changes in single epidermal cell PM voltage and conductance were measured electrophysiologically, changes in root [Ca2+ ]cyt were measured with aequorin, and root transcriptional changes were determined by quantitative real-time PCR. Two cngc2 loss-of-function mutants were used: cngc2-3 and defence not death1 (which expresses cytosolic aequorin). Extracellular ATP-induced transient depolarization of Arabidopsis root elongation zone epidermal PM voltage was Ca2+ dependent, requiring CNGC2 but not CNGC4 (its channel co-subunit in immunity signalling). Activation of PM Ca2+ influx currents also required CNGC2. The eATP-induced [Ca2+ ]cyt increase and transcriptional response in cngc2 roots were significantly impaired. CYCLIC NUCLEOTIDE-GATED CHANNEL2 is required for eATP-induced epidermal Ca2+ influx, causing depolarization leading to [Ca2+ ]cyt increase and damage-related transcriptional response

    Litigation and the Timing of Settlement: Evidence from Commercial Disputes

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    Although an overwhelming proportion of all legal disputes end in settlement, the determinants of the timing of settlement remain empirically underexplored. We draw on a novel dataset on the duration of commercial disputes in Slovenia to study how the timing of settlement is shaped by the stages and features of the litigation process. Using competing risk regression analysis, we find that events such as court-annexed mediation and the first court session, which enable the disputing parties to refine their respective expectations about the case outcome, in general reduce case duration to settlement. The magnitude of the respective effects, however, varies with time. Completion of subsequent court sessions, in contrast, does not affect the time to settlement. Judicial workload affects the timing of settlement indirectly, via the effect on the timing of the first court session. We also examine the effect of other case and party characteristics

    Led into Temptation? Rewarding Brand Logos Bias the Neural Encoding of Incidental Economic Decisions

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    Human decision-making is driven by subjective values assigned to alternative choice options. These valuations are based on reward cues. It is unknown, however, whether complex reward cues, such as brand logos, may bias the neural encoding of subjective value in unrelated decisions. In this functional magnetic resonance imaging (fMRI) study, we subliminally presented brand logos preceding intertemporal choices. We demonstrated that priming biased participants' preferences towards more immediate rewards in the subsequent temporal discounting task. This was associated with modulations of the neural encoding of subjective values of choice options in a network of brain regions, including but not restricted to medial prefrontal cortex. Our findings demonstrate the general susceptibility of the human decision making system to apparently incidental contextual information. We conclude that the brain incorporates seemingly unrelated value information that modifies decision making outside the decision-maker's awareness

    Ovarian cancer risk factors by tumor aggressiveness : An analysis from the Ovarian Cancer Cohort Consortium

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    Ovarian cancer risk factors differ by histotype; however, within subtype, there is substantial variability in outcomes. We hypothesized that risk factor profiles may influence tumor aggressiveness, defined by time between diagnosis and death, independent of histology. Among 1.3 million women from 21 prospective cohorts, 4,584 invasive epithelial ovarian cancers were identified and classified as highly aggressive (death in = 35 vs. 20 to <25 kg/m(2), 1.93 [1.46-2.56] and current smoking (vs. never, 1.30 [1.07-1.57]) were associated with increased risk of highly aggressive disease. Results were similar within histotypes. Ovarian cancer risk factors may be directly associated with subtypes defined by tumor aggressiveness, rather than through differential effects on histology. Studies to assess biological pathways are warranted.Peer reviewe

    Inside Post-Socialist Courts: The Determinants of Adjudicatory Outcomes in Slovenian Commercial Disputes

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    Despite the judiciary's central role in the capitalist market system, micro-level empirical analyses of courts in post-socialist countries are remarkably rare. This paper draws on a unique hand-collected dataset of commercial claims filed at Slovenian courts to examine the determinants of two salient adjudicatory outcomes: whether a case was resolved via trial or settlement and if the case was tried, whether the plaintiff was awarded the initial claim. Consistent with the divergent expectations theory of litigation, we find that trial-based resolution is more likely when the case is complex and less likely when parties use mediation. Addressing sample selection and endogeneity concerns, we show that defendant's legal representation, plaintiff's profitability, and, importantly, court identity are robust predictors of plaintiff victory at trial. Thus, more than two decades after the start of transition in Slovenia, the judicial system is still a source of legal inconsistency and uncertainty

    Plasticity in dendroclimatic response across the distribution range of Aleppo pine (Pinus halepensis)

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    We investigated the variability of the climate-growth relationship of Aleppo pine across its distribution range in the Mediterranean Basin. We constructed a network of tree-ring index chronologies from 63 sites across the region. Correlation function analysis identified the relationships of tree-ring index to climate factors for each site. We also estimated the dominant climatic gradients of the region using principal component analysis of monthly, seasonal, and annual mean temperature and total precipitation from 1,068 climatic gridpoints. Variation in ring width index was primarily related to precipitation and secondarily to temperature. However, we found that the dendroclimatic relationship depended on the position of the site along the climatic gradient. In the southern part of the distribution range, where temperature was generally higher and precipitation lower than the regional average, reduced growth was also associated with warm and dry conditions. In the northern part, where the average temperature was lower and the precipitation more abundant than the regional average, reduced growth was associated with cool conditions. Thus, our study highlights the substantial plasticity of Aleppo pine in response to different climatic conditions. These results do not resolve the source of response variability as being due to either genetic variation in provenance, to phenotypic plasticity, or a combination of factors. However, as current growth responses to inter-annual climate variability vary spatially across existing climate gradients, future climate-growth relationships will also likely be determined by differential adaptation and/or acclimation responses to spatial climatic variation. The contribution of local adaptation and/or phenotypic plasticity across populations to the persistence of species under global warming could be decisive for prediction of climate change impacts across populations. In this sense, a more complex forest dynamics modeling approach that includes the contribution of genetic variation and phenotypic plasticity can improve the reliability of the ecological inferences derived from the climate-growth relationships.This work was partially supported by Spanish Ministry of Education and Science co-funded by FEDER program (CGL2012-31668), the European Union and the National Ministry of Education and Religion of Greece (EPEAEK- Environment – Archimedes), the Slovenian Research Agency (program P4-0015), and the USDA Forest Service. The cooperation among international partners was supported by the COST Action FP1106, STREeSS
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