bluuebunny/crossref_metadata_2025_split huggingface dataset:
The megalithic necropolis of Panoria, Granada, Spain: Geoarchaeological characterization and provenance studies
Authors: Aranda Jiménez Gonzalo , Lozano Jose A. , Pérez Valera Fernando 
Published: September 2017

AbstractThe characterization of materials used in the construction of megalithic monuments can be considered a key aspect for a better understanding of the social behavior of past societies. The excavation of four dolmens and one small cist in 2015 at the megalithic necropolis of Panoria (Granada, Spain) offered an excellent opportunity to explore the geological properties and potential source area(s) of the uprights used in their construction. All the stone slabs came from the same raw material: fine‐grained, beige to pink limestones that occasionally show red and black chert nodules, with wavy stratifications and a packstone texture. Comparison with the geological properties of the surrounding outcrops matches a lithostratigraphy known as the Ammonitico Rosso Formation. Thus, it seems safe to say that the quarry area was located next to the necropolis. Explanations other than the traditional practical reasons have been put forward to understand why the stone slabs were quarried from the same mountain in which the tombs were located.
Mechanical plasticity during oligodendrocyte differentiation and myelination
Authors: Domingues Helena S. , Cruz Andrea , Chan Jonah R. , Relvas João B. , Rubinstein Boris , Pinto Inês Mendes 
Published: September 2017

AbstractIn the central nervous system, oligodendrocyte precursor cells are exclusive in their potential to differentiate into myelinating oligodendrocytes. Oligodendrocyte precursor cells migrate within the parenchyma and extend cell membrane protrusions that ultimately evolve into myelinating sheaths able to wrap neuronal axons and significantly increase their electrical conductivity. The subcellular force generating mechanisms driving morphological and functional transformations during oligodendrocyte differentiation and myelination remain elusive. In this review, we highlight the mechanical processes governing oligodendrocyte plasticity in a dynamic interaction with the extracellular matrix.
Decoding the neural representation of story meanings across languages
Authors: Dehghani Morteza , Boghrati Reihane , Man Kingson , Hoover Joe , Gimbel Sarah I. , Vaswani Ashish , Zevin Jason D. , Immordino‐Yang Mary Helen , Gordon Andrew S. , Damasio Antonio , Kaplan Jonas T. 
Published: September 2017

AbstractDrawing from a common lexicon of semantic units, humans fashion narratives whose meaning transcends that of their individual utterances. However, while brain regions that represent lower‐level semantic units, such as words and sentences, have been identified, questions remain about the neural representation of narrative comprehension, which involves inferring cumulative meaning. To address these questions, we exposed English, Mandarin, and Farsi native speakers to native language translations of the same stories during fMRI scanning. Using a new technique in natural language processing, we calculated the distributed representations of these stories (capturing the meaning of the stories in high‐dimensional semantic space), and demonstrate that using these representations we can identify the specific story a participant was reading from the neural data. Notably, this was possible even when the distributed representations were calculated using stories in a different language than the participant was reading. Our results reveal that identification relied on a collection of brain regions most prominently located in the default mode network. These results demonstrate that neuro‐semantic encoding of narratives happens at levels higher than individual semantic units and that this encoding is systematic across both individuals and languages. Hum Brain Mapp 38:6096–6106, 2017. © 2017 Wiley Periodicals, Inc.
Atypical neuronal activation during a spatial working memory task in 13‐year‐old very preterm children
Authors: Arthursson Pia‐Maria S. H. , Thompson Deanne K. , Spencer‐Smith Megan , Chen Jian , Silk Tim , Doyle Lex W. , Anderson Peter J. 
Published: September 2017

AbstractChildren born very preterm (VP; <32 weeks' gestational age) are at risk for unfavorable outcomes in several cognitive domains, including spatial working memory (WM). The underlying neural basis of these cognitive impairments is poorly understood. We investigated differences in neuronal activation during spatial WM using a backward span (BS) task relative to a control (C) task in 45 VP children and 19 term‐born controls aged 13 years. VP children showed significantly more activation in the bilateral superior frontal gyrus and significantly less activation in the left parahippocampal gyrus compared with controls. We further explored the distinct contributions of maintenance and manipulation processes of WM using forward span (FS)>C and BS > FS, respectively. There were no significant group differences in neuronal activation for FS > C. However, BS > FS revealed that VP children had significantly greater activation in the left middle frontal gyrus, in the left superior parietal gyrus and right cerebellar tonsil, and significantly less activation in the right precentral and postcentral gyrus and left insula compared with controls. Taken together these results suggest that VP children at 13 years of age show an atypical neuronal activation during spatial WM, specifically related to manipulation of spatial information in WM. It is unclear whether these findings reflect delayed maturation and/or recruitment of alternative neuronal networks as a result of neuroplasticity. Hum Brain Mapp 38:6172–6184, 2017. © 2017 Wiley Periodicals, Inc.
Dynamic functional connectivity and individual differences in emotions during social stress
Authors: Tobia Michael J. , Hayashi Koby , Ballard Grey , Gotlib Ian H. , Waugh Christian E. 
Published: September 2017

AbstractExposure to acute stress induces multiple emotional responses, each with their own unique temporal dynamics. Dynamic functional connectivity (dFC) measures the temporal variability of network synchrony and captures individual differences in network neurodynamics. This study investigated the relationship between dFC and individual differences in emotions induced by an acute psychosocial stressor. Sixteen healthy adult women underwent fMRI scanning during a social evaluative threat (SET) task, and retrospectively completed questionnaires that assessed individual differences in subjectively experienced positive and negative emotions about stress and stress relief during the task. Group dFC was decomposed with parallel factor analysis (PARAFAC) into 10 components, each with a temporal signature, spatial network of functionally connected regions, and vector of participant loadings that captures individual differences in dFC. Participant loadings of two networks were positively correlated with stress‐related emotions, indicating the existence of networks for positive and negative emotions. The emotion‐related networks involved the ventromedial prefrontal cortex, cingulate cortex, anterior insula, and amygdala, among other distributed brain regions, and time signatures for these emotion‐related networks were uncorrelated. These findings demonstrate that individual differences in stress‐induced positive and negative emotions are each uniquely associated with large‐scale brain networks, and suggest that dFC is a mechanism that generates individual differences in the emotional components of the stress response. Hum Brain Mapp 38:6185–6205, 2017. © 2017 Wiley Periodicals, Inc.
Do public hospitals respond to changes in DRG price regulation? The case of birth deliveries in the Italian NHS
Authors: Di Giacomo Marina , Piacenza Massimiliano , Siciliani Luigi , Turati Gilberto 
Published: September 2017

AbstractWe study how changes in Diagnosis‐Related Group price regulation affect hospital behaviour in quasi‐markets with exclusive provision by public hospitals. Exploiting a quasi‐natural experiment, we use a difference‐in‐differences approach to test whether public hospitals respond to an exogenous change in Diagnosis‐Related Group tariffs by increasing C‐section rates and/or by upcoding. Controlling for a detailed set of mother characteristics, we find that price changes did not affect the probability of a C‐section. We do however find evidence of upcoding: Conditional on the birth delivery method (either a C‐section or a vaginal delivery), public hospitals experiencing the largest price change exhibit a higher probability of treating patients coded as complicated. This finding suggests that even public hospitals may be sensitive to market incentives.
Will you still need me, will you still feed me when I'm 64? The health impact of caregiving to one's spouse
Authors: de Zwart P.L. , Bakx P. , van Doorslaer E.K.A. 
Published: September 2017

AbstractInformal care may substitute for formal long‐term care that is often publicly funded or subsidized. The costs of informal caregiving are borne by the caregiver and may consist of worse health outcomes and, if the caregiver has not retired, worse labor market outcomes. We estimate the impact of providing informal care to one's partner on the caregiver's health using data from the Survey of Health, Ageing, and Retirement in Europe. We use statistical matching to deal with selection bias and endogeneity. We find that in the short run caregiving has a substantial effect on the health of caregivers and, for female caregivers, on their health care use. These effects should be taken into account when comparing the costs and benefits of formal and informal care provision. The health effects may, however, be short‐lived, as we do not find any evidence that they persist after 4 or 7 years.
The effect of waiting times on demand and supply for elective surgery: Evidence from Italy
Authors: Riganti Andrea , Siciliani Luigi , Fiorio Carlo V. 
Published: September 2017

AbstractWaiting times are a major policy concern in publicly funded health systems across OECD countries. Economists have argued that, in the presence of excess demand, waiting times act as nonmonetary prices to bring demand for and supply of health care in equilibrium. Using administrative data disaggregated by region and surgical procedure over 2010–2014 in Italy, we estimate demand and supply elasticities with respect to waiting times. We employ linear regression models with first differences and instrumental variables to deal with endogeneity of waiting times. We find that demand is inelastic to waiting times while supply is more elastic. Estimates of demand elasticity are between −0.15 to −0.24. Our results have implications on the effectiveness of policies aimed at increasing supply and their ability to reduce waiting times.
Determinants of transient and persistent hospital efficiency: The case of Italy
Authors: Colombi Roberto , Martini Gianmaria , Vittadini Giorgio 
Published: September 2017

SummaryIn this paper, we extend the 4‐random‐component closed skew‐normal stochastic frontier model by including exogenous determinants of hospital persistent (long‐run) and transient (short‐run) inefficiency, separated from unobserved heterogeneity. We apply this new model to a dataset composed by 133 Italian hospitals during the period 2008–2013. We show that average total inefficiency is about 23%, higher than previous estimates; hence, a model where the different types of inefficiency and hospital unobserved characteristics are not confounded allows us to get less biased estimates of hospital inefficiency. Moreover, we find that transient efficiency is more important than persistent efficiency, as it accounts for 60% of the total one. Last, we find that ownership (for‐profit hospitals are more transiently inefficient and less persistently inefficient than not‐for‐profit ones, whereas public hospitals are less transiently inefficient than not‐for‐profit ones), specialization (specialized hospitals are more transiently inefficient than general ones; i.e., there is evidence of scope economies in short‐run efficiency), and size (large‐sized hospitals are better than medium and small ones in terms of transient inefficiency) are determinants of both types of inefficiency, although we do not find any statistically significant effect of multihospital systems and teaching hospitals.
Spatial effects in hospital expenditures: A district level analysis
Authors: Lippi Bruni Matteo , Mammi Irene 
Published: September 2017

AbstractWe use spatial econometric methods to analyse spillovers in hospital expenditures across Health Districts of the Emilia‐Romagna Region (Italy). We estimate spatial models that allow for global spillovers and distinguish between the expenditures associated with potentially inappropriate hospitalizations and those associated with complex medical procedures. We also investigate the relative contribution of geographical and institutional proximity in explaining spatial dependence, by explicitly modelling different connectivity structures and exploiting them to build alternative spatial weight matrices. We find that interactions largely differ between types of expenditures, with positive spatial effects for potentially inappropriate admissions, the effect being generally not significant for high‐complexity expenditure. Relying on the estimated direct and indirect effects, we also test for the presence of spatial spillovers across districts. Finally, the paper draws policy implications for the public health planner.
Cytoprotective effects of xanthohumol against methylglyoxal‐induced cytotoxicity in MC3T3‐E1 osteoblastic cells
Authors: Suh Kwang Sik , Chon Suk , Choi Eun Mi 
Published: September 2017

AbstractMethylglyoxal (MG) has been suggested to be a major source of intracellular reactive carbonyl compounds, and has been implicated in increasing the levels of advanced glycation end products in age‐related diseases. Xanthohumol is a prenylated flavonoid found in hops (Humulus lupulus) and beer. In the present study, we investigated the effects of xanthohumol on MG‐induced cytotoxicity in osteoblastic MC3T3‐E1 cells. Xanthohumol attenuated MG‐induced cytotoxicity, as evidenced by improved cell viability, and prevented MG‐induced MG‐protein adducts, inflammatory cytokines, reactive oxygen species and mitochondrial superoxide production. In addition, xanthohumol increased glyoxalase I activity, glutathione, heme oxygenase‐1 and nuclear factor erythroid 2‐related factor 2 levels in the presence of MG. Pretreatment with xanthohumol before MG exposure reduced MG‐induced mitochondrial dysfunction. Furthermore, xanthohumol treatment resulted in a significant reduction in the levels of endoplasmic reticulum stress and autophagy induced by MG. Notably, the autophagy‐reducing effect of xanthohumol was abolished after the addition of Ex527, a selective inhibitor of sirtuin 1, suggesting that xanthohumol is an effective sirtuin 1 activator for reducing autophagy. Taken together, our findings suggest xanthohumol as a promising new strategy for preventing diabetic osteopathy.
Instrument visualization using conventional and compressed sensing SEMAC for interventional MRI at 3T
Authors: Sonnow Lena , Gilson Wesley D. , Raithel Esther , Nittka Mathias , Wacker Frank , Fritz Jan 
Published: September 2017

BackgroundInterventional magnetic resonance imaging (MRI) at 3T benefits from higher spatial and temporal resolution, but artifacts of metallic instruments are often larger and may obscure target structures.PurposeTo test that compressed sensing (CS) slice‐encoding metal artifact correction (SEMAC) is feasible for 3T interventional MRI and affords more accurate instrument visualization than turbo spin echo (TSE) and gradient echo (GRE) techniques, and facilitates faster data acquisition than conventional SEMAC.Study TypeProspective.Phantom and SubjectsCadaveric animal and 20 human subjects.Field Strength/SequenceTSE (acquisition time 31 sec), GRE (28–33 sec), SEMAC (128 sec), and CS‐SEMAC (57 sec) pulse sequences were evaluated at 3T.AssessmentArtifact width and length, signal‐to‐noise (SNR), and contrast‐to‐noise (CNR) ratios of 14–22G MR‐conditional needles were measured in a phantom. Subsequently, high‐bandwidth TSE and CS‐SEMAC sequences were assessed in vivo with 20 patient procedures for the size of the metal artifact, image sharpness, image noise, motion artifacts, image contrast, and target, instrument, and structural visibility.Statistical TestsRepeated‐measures‐analysis‐of‐variances and Mann–Whitney U‐tests were applied. P ≤ 0.05 was considered statistically significant.ResultsCS‐SEMAC and SEMAC created the smallest needle artifact widths (3.2–3.3 ± 0.4 mm, P = 1.0), whereas GRE showed the largest needle artifact widths (8.5–8.6 ± 0.4 mm) (P < 0.001). The artifact width difference between high‐bandwidth TSE and CS‐SEMAC was 0.8 ± 0.6 mm (P < 0.01). SEMAC and CS‐SEMAC created the lowest average needle tip errors (0.3–0.4 ± 0.1 mm, P = 1.0). The average tip error difference between high‐bandwidth TSE and SEMAC/CS‐SEMAC was 2.0 ± 1.7 mm (P < 0.01). SNR and CNR were similar on TSE, SEMAC, and CS‐SEMAC, and lowest on GRE. CS‐SEMAC yielded smaller artifacts, less noise, less motion, and better instrument visibility (P < 0.001); high‐bandwidth TSE showed better sharpness (P < 0.001) and targets visibility (P = 0.007); whereas image contrast (P = 0.273) and structural visibility (P = 0.1) were similar.Data ConclusionCS‐SEMAC is feasible for interventional MRI at 3T, visualizes instruments with higher accuracy than high‐bandwidth TSE and GRE, and can be acquired 55% faster than conventional SEMAC.Level of Evidence: 2Technical Efficacy: Stage 6J. Magn. Reson. Imaging 2018;47:1306–1315.
Chronic kidney disease: Pathological and functional evaluation with intravoxel incoherent motion diffusion‐weighted imaging
Authors: Mao Wei , Zhou Jianjun , Zeng Mengsu , Ding Yuqin , Qu Lijie , Chen Caizhong , Ding Xiaoqiang , Wang Yaqiong , Fu Caixia 
Published: September 2017

BackgroundBecause chronic kidney disease (CKD) is a worldwide problem, accurate pathological and functional evaluation is required for planning treatment and follow‐up. Intravoxel incoherent motion diffusion‐weighted imaging (IVIM‐DWI) can assess both capillary perfusion and tissue diffusion and may be helpful in evaluating renal function and pathology.PurposeTo evaluate functional and pathological alterations in CKD by applying IVIM‐DWI.Study TypeProspective study.SubjectsIn all, 72 CKD patients who required renal biopsy and 20 healthy volunteers.Field Strength1.5T.AssessmentAll subjects underwent IVIM‐DWI of the kidneys, and image analysis was performed by two radiologists. The mean values of true diffusion coefficient (D), pseudo diffusion coefficient (D*), and perfusion fraction (f) were acquired from renal parenchyma. Correlation between IVIM‐DWI parameters and estimated glomerular filtration rate (eGFR), as well as pathological damage, were assessed.Statistical TestsOne‐way analysis of variance (ANOVA), paired sample t‐test and Spearman correlation analysis.ResultsThe paired sample t‐test revealed that IVIM‐DWI parameters were significantly lower in medulla than cortex for both patients and controls (P < 0.01). Regardless of whether eGFR was reduced, ANOVA revealed that f values of renal parenchyma were significantly lower in patients than controls (P < 0.05). Spearman correlation analysis revealed that there were positive correlations between eGFR and D (cortex, r = 0.466, P < 0.001; medulla, r = 0.491, P < 0.001), and between eGFR and f (cortex, r = 0.713, P < 0.001; medulla, r = 0.512, P < 0.001). Negative correlations were found between f and glomerular injury (cortex, r = −0.773, P < 0.001; medulla, r = −0.629, P < 0.001), and between f and tubulointerstitial lesion (cortex, r = −0.728, P < 0.001; medulla, r = −0.547, P < 0.001).Data ConclusionIVIM‐DWI might be feasible for noninvasive evaluation of renal function and pathology of CKD, especially in detection of renal insufficiency at an early stage.Level of Evidence: 1Technical Efficacy: Stage 3J. Magn. Reson. Imaging 2018;47:1251–1259.
Seasonal rainfall patterns classification, relationship to ENSO and rainfall trends in Ecuador
Authors: Tobar Vladimiro , Wyseure Guido 
Published: September 2017

ABSTRACTWater is one of Ecuador's most important natural resources, whose management should rely on good information and adequate models for the water balance. Although there are many studies focusing on rainfall and temperatures, most of them are localized for specific projects or study basins. The convergence of factors like its location in the Intertropical Convergence Zone, the Amazon River basin, the complex topography of the Andes, and being next to the Pacific Ocean impacted by the El Niño Southern Oscillation, modelling climate in Ecuador is a challenging task.The aim of this research was to classify seasonal rainfall patterns, using robust procedures to deal with missing values and outliers. The selected database contained 319 stations with monthly rainfall from 1982 to 2011. A hierarchical clustering technique applied to the proportion of monthly rainfall percentiles allowed identifying four clusters that, when compared to a digital elevation model, resulted geographically related to Sierra, Coast, Amazon and Coast Orographic Sierra (COS). Coast shows strong seasonality with the dry season from June to November, while COS presents a similar pattern with moderate seasonality, the Amazon exhibits mild to no seasonality and the Sierra with a moderate seasonality. Interestingly, the Amazon seasonality enters rather deep into the Sierra through large river valleys. Cumulative differential plots of the standardized deleted deviations of monthly rainfall aided detecting cluster dependent El Niño effects in rainfall for Coast and COS. Correlations of rainfall versus SST at El Niño regions were also cluster dependent, with low to no significant correlations for Amazon, higher correlations for Coast and COS and moderate correlations for Sierra. Monthly rainfall trends assessed by the non‐parametric method of Sen's slopes, showed overall decreasing trends for September and October rainfall and increasing from February to April, thus suggesting a strengthening of seasonality.
A comprehensive view on trends in extreme precipitation in Nepal and their spatial distribution
Authors: Bohlinger Patrik , Sorteberg Asgeir 
Published: September 2017

ABSTRACTWe investigate trends in monsoon and extreme precipitation in Nepal based on rain gauge measurements. We find that precipitation amounts in Nepal vary considerably in space and time. The number of occurring extremes and the amount of precipitation are controlled mainly by the Indian summer monsoon. Almost all extreme precipitation events, recorded by 98 considered meteorological stations, occur during the Indian summer monsoon with the maximum in July. For Nepal in general, we find that the amount of precipitation and number of extreme events per station are neither significantly increasing nor decreasing between 1971 and 2010. However, on a regional scale we identify areas with positive and negative trends. A comparison of the combined precipitation time series with the ENSO 3.4 index reveals a connection between ENSO and the variability in monsoon precipitation. The correlation with the number of monsoon extremes vanishes for increasing percentiles. We investigate trends of upper percentiles of daily precipitation which pinpoint regions of increasing and decreasing extremes. These patterns are similar to spatial patterns in mean monsoon precipitation trends, whereas the median of the precipitation distribution undergoes only minor changes. Further analysis using extreme value theory confirm the prevailing trends from quantile regression for most stations and depict strong changes in return levels. Especially for Far‐West Nepal, we find robust evidence for a systematic increase in extreme precipitation.