bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanical resistance of screwless morse taper and screw‐retained implant‐abutment connections
Authors: Ugurel Cihan Sadi , Steiner Martin , Isik‐Ozkol Gul , Kutay Omer , Kern Matthias 
Published: December 2013

AbstractObjectiveThe screwless morse taper (SMT) implant‐abutment connection is an alternative to conventional external or internal screw‐retained (ISR) connections. The aim of this in vitro study was to evaluate mechanical resistance of the SMT connection and to compare it with three different ISR connections.Materials and MethodsFour implant systems were tested in this study: SMT system; Tasarimmed Octo (Istanbul, Turkey), ISR systems; Straumann Bone Level (Basel, Switzerland), Biohorizons Internal (Birmingham, AL, USA), and Dentsply Friadent Xive (Mannheim, Germany). Overall, 64 specimens with stylized single crowns were prepared: 32 for dynamic loading (DL) and 32 for static loading (SL). DL was carried out using a chewing simulator with 120 N at 1.75 Hz for 1.2 × 106 cycles, and SL was performed with a universal testing machine at a crosshead speed of 2 mm/min with an angulation of 30°. Cycles until failure from DL and fracture/bending loads at SL were recorded. Statistical analyses were made with Dunn's multiple comparison.ResultsMedian cycles until failure in DL were as follows: Octo 86,354 (24,810–153,875), Straumann 1,200,000 (1,156,618–1,200,000), Biohorizons 539,719 (437,224–858,732), Xive 139,411 (139,411–139,411). Median fracture/bending loads in Newton at SL were as follows: Octo 429.6 (404.5–482.7), Straumann 574.6 (544.6–629.9), Biohorizons 548.7 (532.9–567.3), Xive 431.5 (412.5–520.5). There were significant differences between the implant systems under both loading conditions (P ≤ 0.05) revealing that the Octo implant system's SMT connection showed significantly lower cycles to failures and lower fracture/bending loads compared with the ISR connections of the Straumann and Biohorizons implant systems. However, there was no significant difference compared with the Xive implant system.ConclusionThe mechanical resistance of the screwless morse taper implant system is lower than that of the ISR implant systems that might result in more frequent clinical complications.
Influence of immediate loading on healing of implants installed with different insertion torques – an experimental study in dogs
Authors: Rea Massimiliano , Botticelli Daniele , Ricci Sara , Soldini Claudio , González Gladys González , Lang Niklaus P. 
Published: December 2013

AbstractObjectiveTo evaluate the influence of different insertion torques on healing of implants loaded immediately or left unloaded.Material and methodsIn six Labrador dogs, all mandibular premolars and molars were extracted. After 4 months of healing, flaps were elevated, and two implant sites were prepared at each side of the mandible. The distal sites were prepared conventionally while the mesial sites were underprepared by 0.3 mm. As a consequence, different final insertion torques of about 30 Ncm at the distal and >70 Ncm at the mesial sites were recorded. Healing abutments were applied to the left and transmucosal abutments to the right side. Flaps were sutured, crown preparation of the upper right second and third premolars was performed, and impressions were taken. Within 24 h, crowns were cemented both to implants and teeth in the right side of the mouth. After 4 months, the animals were sacrificed and ground sections obtained for histological evaluation.ResultsA higher buccal bony crestal resorption and a more apical position of the coronal level of osseointegration were found at the loaded compared with the unloaded sites. MBIC% and percentages of peri‐implant mineralized tissue (MB%) were higher at the loaded compared with the unloaded sites. Moreover, a higher MBIC% was found at the lower compared with the higher final insertion torque.ConclusionsImmediate loading does not seem to have a negative effect on osseointegration. High torque values for the immediate loading procedures were not necessary. Probably, low torque values, were sufficient to obtain primary stability and hence may provide better osseointegration than high torque value.
Relationship between cardiac function and resting cerebral blood flow: MRI measurements in healthy elderly subjects
Authors: Henriksen Otto M. , Jensen Lars T. , Krabbe Katja , Larsson Henrik B. W. , Rostrup Egill 
Published: December 2013

SummaryAlthough both impaired cardiac function and reduced cerebral blood flow are associated with ageing, current knowledge of the influence of cardiac function on resting cerebral blood flow (CBF) is limited. The aim of this study was to investigate the potential effects of cardiac function on CBF. CBF and cardiac output were measured in 31 healthy subjects 50–75 years old using magnetic resonance imaging techniques. Mean values of CBF, cardiac output and cardiac index were 43·6 ml per 100 g min−1, 5·5 l min−1 and 2·7 l min−1 m−2, respectively, in males, and 53·4 ml per 100 g min−1, 4·3 l min−1 and 2·4 l min−1 m−2, respectively, in females. No effects of cardiac output or cardiac index on CBF or structural signs of brain ageing were observed. However, fractional brain flow defined as the ratio of total brain flow to cardiac output was inversely correlated with cardiac index (r2 = 0·22, P = 0·008) and furthermore lower in males than in females (8·6% versus 12·5%, P = 0·003). Fractional brain flow was also inversely correlated with cerebral white matter lesion grade, although this effect was not significant when adjusted for age. Frequency analysis of heart rate variability showed a gender‐related inverse association of increased low‐to‐high‐frequency power ratio with CBF and fractional brain flow. The findings do not support a direct effect of cardiac function on CBF, but demonstrates gender‐related differences in cardiac output distribution. We propose fractional brain flow as a novel index that may be a useful marker of adequate brain perfusion in the context of ageing as well as cardiovascular disease.
Stable numerosity representations irrespective of magnitude context in macaque prefrontal cortex
Authors: Moskaleva Maria , Nieder Andreas 
Published: December 2013

AbstractCognitively demanding tasks require neurons of the prefrontal cortex (PFC) to encode divergent behaviorally relevant information. In discrimination tasks with arbitrary and learned categories, context‐specific parameters shape and adapt the tuning functions of PFC neurons. We explored if and how selectivity of PFC neurons to visual numerosities, a ‘natural’ abstract category, may change depending on the magnitude context. Two monkeys discriminated visual numerosities (varying numbers of dot items) in a delayed match‐to‐sample (DMS) task while single‐cell activity was recorded from the lateral PFC. During a given recording session, the numerosity task was either presented in isolation or randomly intermixed with DMS tasks with line lengths and colors as discriminative stimuli. We found that the context of numerosity discriminations did not influence the response properties of numerosity detectors. The numerosity tuning curves of selective neurons, i.e. the preferred numerosity and the sharpness of tuning, remained stable, irrespective of whether the numerosity task was presented in a pure numerosity block or a mixed magnitude block. Our data suggest that numerosity detectors in the PFC do not adapt their response properties to code stimuli according to changing magnitude context. Rather, numerosity representations seem to rely on a sparse and stable ‘labeled line’ code. In contrast to arbitrarily learned categories, numerosity as a ‘natural’ category may possess a privileged position and their neuronal representations could thus remain unaffected by magnitude context.
Withdrawal of antiepileptic drugs: Guidelines of the Italian League Against Epilepsy
Authors: Beghi Ettore , Giussani Giorgia , Grosso Salvatore , Iudice Alfonso , Neve Angela La , Pisani Francesco , Specchio Luigi M. , Verrotti Alberto , Capovilla Giuseppe , Michelucci Roberto , Zaccara Gaetano 
Published: December 2013

SummaryThe Italian League Against Epilepsy has issued evidence‐based guidelines to help practicing physicians in their decision to stop or withhold antiepileptic drugs (AEDs) in patients achieving a prolonged period of seizure freedom. Six adult and two child neurologists, divided into four pairs, critically appraised 128 published reports and provided graded recommendations answering 15 key questions: length of the seizure‐free period after treatment initiation, difference in seizure‐free periods in children and adults, electroencephalography (EEG) pattern at the time of discontinuation, etiology of epilepsy, seizure type(s), patient's age and sex, family history of epilepsy, history of febrile seizures, epilepsy syndrome, seizure frequency before entering remission, duration of active epilepsy, tapering period, number and type of AEDs taken at time of discontinuation, combination of risk factors for recurrence, and length of patient monitoring after treatment discontinuation. Based on the available data, the following recommendations can be outlined: (1) antiepileptic treatment might be discontinued after a minimum period of 2 years of seizure freedom; shorter seizure‐free periods are associated to a higher risk of relapse; (2) in children, AED discontinuation could be considered after less than two seizure‐free years because of a marginally higher risk of relapse for early withdrawal; (3) factors, such as abnormal EEG (including epileptiform abnormalities) at the time of treatment discontinuation, a documented etiology of seizures (including mental retardation, perinatal insults, and abnormal neurologic examination), partial seizures, or an older age at disease onset, enhance the risk of relapse; however, patients should not be encouraged to withhold treatment unless a combination of two or more of these factors is present; (4) female sex, family history of epilepsy, history of febrile seizures, disease length/severity, and number and type of drugs taken should not influence the decision to stop treatment; (5) epilepsy syndrome should be always included in the decision process; (6) slow (at least 6 months) AED discontinuation should be encouraged; in any case the duration of the tapering period should be tailored to the patient's needs and preference; and (7) patient discontinuing treatment should be followed for no <2 years. As a general habit, the decision to stop treatment should be discussed and shared with each patient, taking into account social and personal complications of a seizure relapse and the medical complications of chronic AED treatment.
Almost 50 years of monitoring shows that climate, not forestry, controls long‐term organic carbon fluxes in a large boreal watershed
Authors: Lepistö Ahti , Futter Martyn N , Kortelainen Pirkko 
Published: December 2013

AbstractHere, we use a unique long‐term data set on total organic carbon (TOC) fluxes, its climatic drivers and effects of land management from a large boreal watershed in northern Finland. TOC and runoff have been monitored at several sites in the Simojoki watershed (3160 km2) since the early 1960s. Annual TOC fluxes have increased significantly together with increased inter‐annual variability. Acid deposition in the area has been low and has not significantly influenced losses of TOC. Forest management, including ditching and clear felling, had a minor influence on TOC fluxes – seasonal and long‐term patterns in TOC were controlled primarily by changes in soil frost, seasonal precipitation, drought, and runoff. Deeper soil frost led to lower spring TOC concentrations in the river. Summer TOC concentrations were positively correlated with precipitation and soil moisture not temperature. There is some indication that drought conditions led to elevated TOC concentrations and fluxes in subsequent years (1998–2000). A sensitivity analysis of the INCA‐C model results showed the importance of landscape position, land‐use type, and soil temperature as controls of modeled TOC concentrations. Model predictions were not sensitive to forest management. Our results are contradictory to some earlier plot‐scale and small catchment studies that have shown more profound forest management impacts on TOC fluxes. This shows the importance of scale when assessing the mechanisms controlling TOC fluxes and concentrations. The results highlight the value of long‐term multiple data sets to better understand ecosystem response to land management, climate change and extremes in northern ecosystems.
Assessment of the oral health knowledge of healthcare providers in geriatric nursing homes: additional training needs required
Authors: Catteau Céline , Piaton Sophie , Nicolas Emmanuel , Hennequin Martine , Lassauzay Claire 
Published: December 2013

ObjectivesThis study was aimed at assessing the knowledge of oral health and training needs of health workers in geriatric nursing homes.BackgroundProviding daily oral care to dependent elderly people is the best way to prevent oral disorders. Because there are no dental hygienists in France, health workers play an important role in providing oral care in nursing homes and should have correct and adequate knowledge.Materials and methodsHealth workers from 8 geriatric nursing homes in Puy de Dôme (France) completed a 58‐item questionnaire. Oral health knowledge regarding dental decay, periodontal diseases, oral hygiene and denture care was assessed. Univariate and bivariate analyses were performed.ResultsA total of 99 health workers took part in the study. The total mean score was significantly different if health workers had received training in oral disorders (49.3 ± 11.7 vs. 43.9 ± 10; p < 0.05) or in the maintenance of oral health (50.5 ± 10.5 vs. 42.9 ± 10; p < 0.01). The mean scores obtained in the ‘dental decay’ subsection and in the ‘oral and denture hygiene’ subsection were the lowest.ConclusionGeriatric nursing home staff need training in understanding the impact of oral health on general health. Theoretical knowledge of oral diseases has to be improved in order for health workers to understand oral hygiene procedures and to help them identify early oral disorders.
Preserving Heritage and the Values of Exchange: Lessons from Nigeria
Authors: Probst Peter 
Published: December 2013

AbstractResearch on heritage preservation in Africa shows a field shaped by different and often opposite positions as to the actual meaning of heritage. Does heritage signify valuable remnants of the past that require safeguarding and protection? Or, is heritage first and foremost a contemporary practice by which the past comes to matter in the present? This paper aims to link and negotiate between these two positions. The empirical basis stems from my own research on how the sacred grove of the Yoruba river deity Osun in Southwest Nigeria became a UNESCO World Heritage Site. Drawing on the insights of this research, I argue that heritage is a relationship embedded in spheres of exchange that generate both moral and material forms of value. Conceiving heritage as exchange, so I contend, not only allows for a better understanding of the multiple values of heritage; it also sharpens interest in the struggles of control over the media of exchange. This paper examines these struggles with respect to the different spheres of exchange (local, national, and global) in which the grove of the river goddess Osun is entangled.
ANIMALS WITH RICH HISTORIES: THE CASE OF THE LIONS OF GIR FOREST, GUJARAT, INDIA
Authors: RANGARAJAN MAHESH 
Published: December 2013

ABSTRACTThis article explores how far animals are or are not endowed with a sense of history. The century‐long history of lion–human interaction in the lions' last habitat in Asia—in India's Gir Forest, Gujarat State—is the focal point of analysis. In turn, there have been longer‐term shifts since ancient and medieval times. Aside from two specific phases of breakdown, Gir's lions rarely attack people. To comprehend why this is so, both the lions and humans need to be seen as products of history. Although it is going too far to endow the lions with historical consciousness, Gir's lions clearly do have memory of memories. Over a half‐century since hunting ceased, living on a mix of domestic livestock and wild prey, they now co‐inhabit not only the forest but a much larger territory in close proximity to resident people. Their case calls for rethinking both animal and human histories to allow for associate species that adapt to human presence, and are capable of memory.
The Market Timing Power of Moving Averages: Evidence from US REITs and REIT Indexes
Authors: Glabadanidis Paskalis 
Published: December 2013

AbstractI present evidence that a moving average (MA) trading strategy dominates buying and holding the underlying asset in a mean‐variance sense using monthly returns of value‐weighted and equal‐weighted US REIT indexes over the period January 1980 until December 2010. The abnormal returns are largely insensitive to the four Carhart factors and produce economically and statistically significant alphas of between 10 and 15% per year after transaction costs. This performance is robust to different lags of the MA and in subperiods while investor sentiment, liquidity risks, business cycles, up and down markets, and the default spread cannot fully account for its performance. The MA strategy works just as well with randomly generated returns and bootstrapped returns. The substantial market timing ability of the MA strategy appears to be the main driver of the abnormal returns. The returns to the MA strategy resemble the returns of an imperfect at‐the‐money protective put strategy relative to the underlying portfolio. The lagged signal to switch has substantial predictive power over the subsequent return of the REIT index. The MA strategy avoids the sharp downturn at the beginning of 2008 and substantially outperforms the cumulative returns of the buy‐and‐hold strategy using all of the 20 REIT indexes. The results from applying the MA strategy with 274 individual REITs largely corroborate the findings for the REIT indexes.
Frequency and Motives for Stock Dividends in a Unique Environment
Authors: Al‐Yahyaee Khamis H. 
Published: December 2013

AbstractWe investigate the possible differences in the information content of stock dividends between firms that distribute stock dividends frequently (frequent distributors) and firms that distribute stock dividends infrequently (infrequent distributors) using a unique data set from Oman where the market microstructure frictions are either absent or limited. We find that infrequent stock dividend distributors have higher postdistribution operating performance relative to frequent distributors. We also find that the illiquidity measure is significantly related to the announcement effect only for frequent stock dividend distributors, whereas short‐term performance is significantly related to the announcement effect only for infrequent distributors. Our findings indicate that infrequent stock dividends are used mainly to convey favorable private information about the firms’ future prospects, and frequent stock dividends are used to reduce stock price to an optimal trading range in order to improve trading liquidity.JEL classification: G14, G35.
Assessing the probability of large‐scale flood loss events: a case study for the river Rhine, Germany
Authors: Thieken A.H. , Apel H. , Merz B. 
Published: December 2013

AbstractFlood risk analyses are often estimated assuming the same flood intensity along the river reach under study, i.e. discharges are calculated for a number of return periods T, e.g. 10 or 100 years, at several streamflow gauges. T‐year discharges are regionalised and then transferred into T‐year water levels, inundated areas and impacts. This approach assumes that (1) flood scenarios are homogeneous throughout a river basin, and (2) the T‐year damage corresponds to the T‐year discharge. Using a reach at the river Rhine, this homogeneous approach is compared with an approach that is based on four flood types with different spatial discharge patterns. For each type, a regression model was created and used in a Monte‐Carlo framework to derive heterogeneous scenarios. Per scenario, four cumulative impact indicators were calculated: (1) the total inundated area, (2) the exposed settlement and industrial areas, (3) the exposed population and 4) the potential building loss. Their frequency curves were used to establish a ranking of eight past flood events according to their severity. The investigation revealed that the two assumptions of the homogeneous approach do not hold. It tends to overestimate event probabilities in large areas. Therefore, the generation of heterogeneous scenarios should receive more attention.
Prospective registry of symptomatic severe aortic stenosis in octogenarians: a need for intervention
Authors: Martínez‐Sellés M. , Gómez Doblas J. J. , Carro Hevia A. , García de la Villa B. , Ferreira‐González I. , Alonso Tello A. , Andión Ogando R. , Ripoll Vera T. , Arribas Jiménez A. , Carrillo P. , Rodríguez Pascual C. , Casares i Romeva M. , Borras X. , Cornide L. , López‐Palop R. ,   the PEGASO Registry Group
Published: December 2013

AbstractObjectiveTo study the factors associated with choice of therapy and prognosis in octogenarians with severe symptomatic aortic stenosis (AS).Study DesignProspective, observational, multicenter registry. Centralized follow‐up included survival status and, if possible, mode of death and Katz index.SettingTransnational registry in Spain.SubjectsWe included 928 patients aged ≥80 years with severe symptomatic AS.InterventionsAortic‐valve replacement (AVR), transcatheter aortic‐valve implantation (TAVI) or conservative therapy.Main outcome measuresAll‐cause death.ResultsMean age was 84.2 ± 3.5 years, and only 49.0% were independent (Katz index A). The most frequent planned management was conservative therapy in 423 (46%) patients, followed by TAVI in 261 (28%) and AVR in 244 (26%). The main reason against recommending AVR in 684 patients was high surgical risk [322 (47.1%)], other medical motives [193 (28.2%)], patient refusal [134 (19.6%)] and family refusal in the case of incompetent patients [35 (5.1%)]. The mean time from treatment decision to AVR was 4.8 ± 4.6 months and to TAVI 2.1 ± 3.2 months, P < 0.001. During follow‐up (11.2–38.9 months), 357 patients (38.5%) died. Survival rates at 6, 12, 18 and 24 months were 81.8%, 72.6%, 64.1% and 57.3%, respectively. Planned intervention, adjusted for multiple propensity score, was associated with lower mortality when compared with planned conservative treatment: TAVI Hazard ratio (HR) 0.68 (95% confidence interval [CI] 0.49–0.93; P = 0.016) and AVR HR 0.56 (95% CI 0.39–0.8; P = 0.002).ConclusionOctogenarians with symptomatic severe AS are frequently managed conservatively. Planned conservative management is associated with a poor prognosis.