bluuebunny/crossref_metadata_2025 huggingface dataset:
Restricted sums of four squares
Authors: Sun Zhi-Wei
Published: May 2019

We refine Lagrange’s four-square theorem in new ways by imposing some restrictions involving powers of two (including [Formula: see text]). For example, we show that each [Formula: see text] can be written as [Formula: see text] ([Formula: see text] with [Formula: see text] (or [Formula: see text], or [Formula: see text]), and that we can write any positive integer as [Formula: see text] with [Formula: see text] (or [Formula: see text]) a power of four. We also prove that any [Formula: see text] can be written as [Formula: see text] [Formula: see text] with [Formula: see text] a square (or a cube). In addition, we pose some open conjectures for further research; for example, we conjecture that any integer [Formula: see text] can be written as [Formula: see text] with [Formula: see text].
Differential principal factors and Pólya property of pure metacyclic fields
Authors: Mayer Daniel C.
Published: May 2019

Barrucand and Cohn’s theory of principal factorizations in pure cubic fields [Formula: see text] and their Galois closures [Formula: see text] with [Formula: see text] types is generalized to pure quintic fields [Formula: see text] and pure metacyclic fields [Formula: see text] with [Formula: see text] possible types. The classification is based on the Galois cohomology of the unit group [Formula: see text], viewed as a module over the automorphism group [Formula: see text] of [Formula: see text] over the cyclotomic field [Formula: see text], by making use of theorems by Hasse and Iwasawa on the Herbrand quotient of the unit norm index [Formula: see text] by the number [Formula: see text] of primitive ambiguous principal ideals, which can be interpreted as principal factors of the different [Formula: see text]. The precise structure of the group of differential principal factors is determined with the aid of kernels of norm homomorphisms and central orthogonal idempotents. A connection with integral representation theory is established via class number relations by Parry and Walter involving the index of subfield units [Formula: see text]. Generalizing criteria for the Pólya property of Galois closures [Formula: see text] of pure cubic fields [Formula: see text] by Leriche and Zantema, we prove that pure metacyclic fields [Formula: see text] of only one type cannot be Pólya fields. All theoretical results are underpinned by extensive numerical verifications of the [Formula: see text] possible types and their statistical distribution in the range [Formula: see text] of [Formula: see text] normalized radicands.
Computing embedding numbers and branches of orders via extensions of the Bruhat-Tits tree
Authors: Arenas-Carmona Luis , Bravo Claudio
Published: May 2019

Let [Formula: see text] be a local field and let [Formula: see text] be the two-by-two matrix algebra over [Formula: see text]. In our previous work, we developed a theory that allows the computation of the set of maximal orders in [Formula: see text] containing a given suborder. This set is given as a subgraph of the Bruhat–Tits (BT)-tree that is called the branch of the order. Branches have been used to study the global selectivity problem and also to compute local embedding numbers. They can usually be described in terms of two invariants. To compute these invariants explicitly, the strategy in our past work has been visualizing branches through the explicit representation of the BT-tree in terms of balls in [Formula: see text]. This is easier for orders spanning a split commutative subalgebra, i.e. an algebra isomorphic to [Formula: see text]. In fact, we have successfully used this idea in the past to compute embedding numbers for the split algebra. In the present work, we develop a theory of branches over field extensions that can be used to extend our previous computations to orders spanning a field. We use the same idea to compute branches for orders generated by arbitrary pairs of non-nilpotent pure quaternions, generalizing previous results due to the first author and Saavedra. We assume throughout that [Formula: see text].
Newton slopes for twisted Artin–Schreier–Witt towers
Authors: Ren Rufei
Published: May 2019

We fix a monic polynomial [Formula: see text] over a finite field of characteristic [Formula: see text] of degree relatively prime to [Formula: see text]. Let [Formula: see text] be the Teichmüller lift of [Formula: see text], and let [Formula: see text] be a finite character of [Formula: see text]. The [Formula: see text]-function associated to the polynomial [Formula: see text] and the so-called twisted character [Formula: see text] is denoted by [Formula: see text] (see Definition 1.2). We prove that, when the conductor of the character is large enough, the [Formula: see text]-adic Newton slopes of this [Formula: see text]-function form arithmetic progressions.
The Mesoproterozoic Stac Fada proximal ejecta blanket, NW Scotland: constraints on crater location from field observations, anisotropy of magnetic susceptibility, petrography and geochemistry
Authors: Amor Kenneth , Hesselbo Stephen P. , Porcelli Don , Price Adam , Saunders Naomi , Sykes Martin , Stevanović Jennifer , MacNiocaill Conal
Published: May 2019

The Stac Fada Member of the Mesoproterozoic Stoer Group (Torridon Supergroup) in NW Scotland is a proximal ejecta blanket surrounding an unidentified asteroid impact crater. A combination of field observations of the ejecta deposit and underlying strata, the geographical distribution of terrane-identified basement clasts found embedded in the impactite, and anisotropy of magnetic susceptibility of the impact melt rocks at different locations can constrain the crater location to be about 15–20 km WNW of Enard Bay and thus buried under Mesozoic sediments in The Minch. Syncompressional structures within the suevite at Stattic Point give a clear indication of a southeasterly direction of mass motion. The signatures of two different terranes within the Lewisian gneiss help identify the origin of clasts found in the impactite at three locations. These clasts are unshocked and interpreted as having been swept up by the density current post-impact; their geographical distribution provides an important clue to ejecta emplacement pathways crossing the Assynt and Gruinard terranes. Anisotropy of magnetic susceptibility is used to measure flow direction in pyroclastic density current deposits and is applied here to derive a direction of motion for the impactoclastic density current. It provides good agreement with the other independent methods.
Long-lived mega fault-scarps and related breccias at distal rifted margins: insights from present-day and fossil analogues
Authors: Ribes Charlotte , Ghienne Jean-François , Manatschal Gianreto , Decarlis Alessandro , Karner Garry D. , Figueredo Patricio H. , Johnson Christopher A.
Published: May 2019

Thinning of the continental crust during rifting is accommodated by a number of major faults, only a few of which produce long-lived mega fault-scarps. In this paper, we investigate mega fault-scarps and the sedimentary system located at their toe across magma-poor rifted margins. Our approach combines observations from subsurface examples along present-day margins and field analysis of fossil examples exposed in the Alpine Tethys margins. Whereas present-day examples of rifted margins imaged by seismic techniques provide details about the architecture of the top basement and the relationship between faults and sediments, outcrops give access to the sedimentary features of rocks related to mega fault-scarps. Our study shows that (1) mega fault-scarps are preferentially located at rift domain boundaries, implying a topographic escarpment that juxtaposes rift domains of different crustal thickness, and (2) mega fault-scarps are long-lived local sources for syn- and post-tectonic breccia, respectively produced during and after fault activity.
Crossing political borders
Authors: Vernon Laura
Published: May 2019

This study is a rhetorical analysis of communication design in the Amalga Barrens wetlands controversy during the 1990s. The Bridgerland Audubon Society (Bridgerland) in Cache Valley, Utah, was able to influence a change in public policy that removed the unique wetlands from consideration as a possible reservoir site for water taken from the Bear River. The group tried two times to influence public policy. The first effort failed because the group relied too much on lobbying. The second effort succeeded when the group developed a grassroots communication design. Bridgerland led a successful grassroots effort by (1) educating the public, (2) establishing credibility, (3) proposing an alternative solution, (4) making decisions based on data, (5) recognizing common ground, (6) getting the media involved, (7) building on what has been done before, and (8) practicing civility. Bridgerland's experience may be helpful to other environmental groups that are trying to lead efforts in their own communities. Although the communication design presented cannot be generalized to fit all groups and situations, it may serve as a starting point.
Intensive versus Usual Control of Hypertension in the Prevention of Cardiovascular and Renal Outcomes: A Cumulative Meta-Analysis of Randomized Controlled Trials
Authors: Li Li , Li Ling
Published: May 2019

Background/Aims: Previous studies have reported inconsistent results regarding the treatment effects of intensive blood pressure (IBP) control in the prevention of cardiovascular and renal outcomes. We conducted this cumulative meta-analysis to evaluate the treatment effects of IBP control on cardiovascular and renal outcomes. Methods: We systematically searched PubMed, EMBASE, and the Cochrane Library databases from the date of their inception to October 2017, to identify randomized controlled trials (RCTs). The relative risks (RRs) with corresponding 95% confidence intervals (CIs) were used to evaluate the treatment effects of IBP control by using a random-effects model. Results: The final analysis included 20 RCTs involving 56,687 individuals. The summary RRs indicated that IBP control treatment significantly reduced the risk of major cardiovascular events (RR: 0.85; 95% CI: 0.77–0.94; p = 0.001), including myocardial infarction (RR: 0.87; 95% CI: 0.76–1.00; p = 0.044), stroke (RR: 0.77; 95% CI: 0.66–0.89; p < 0.001), and albuminuria (RR: 0.90; 95% CI: 0.84–0.97; p = 0.007). However, IBP control had no significant effect on heart failure (RR: 0.80; 95% CI: 0.62–1.03; p = 0.077), all-cause mortality (RR: 0.91; 95% CI: 0.81–1.02; p = 0.112), cardiac death (RR: 0.91; 95% CI: 0.75–1.12; p = 0.390), non-cardiac death (RR: 0.98; 95% CI: 0.86–1.12; p = 0.773), end-stage renal disease (RR: 0.90; 95% CI: 0.77–1.06; p = 0.203), and retinopathy (RR: 0.81; 95% CI: 0.66–1.00; p = 0.052). Conclusion: The findings of this study suggest that IBP control plays a beneficial role in the prevention of some major cardiovascular events, including myocardial infarction, stroke, and albuminuria.
Decreased Leptin Is Associated with Alterations in Thyroid-Stimulating Hormone Levels after Roux-en-Y Gastric Bypass Surgery in Obese Euthyroid Patients with Type 2 Diabetes
Authors: Yu Haoyong , Li Qing , Zhang Mingliang , Liu Fangyuan , Pan Jiemin , Tu Yinfang , Lu Junxi , Zhang Pin , Han Junfeng , Jia Weiping , Bao Yuqian
Published: May 2019

Background: Leptin has been shown to stimulate the hypothalamus-pituitary-thyroid (HPT) axis in vivo and vitro. Its role in thyroid axis regulation after weight loss induced by bariatric surgery is still unknown. The aim of this study was to evaluate the influence of leptin on weight loss and thyroid function variation induced by Roux-en-Y gastric bypass (RYGB) surgery in euthyroid individuals with obesity and type 2 diabetes mellitus (T2DM). Methods: 65 Chinese individuals with obesity and T2DM who underwent RYGB, and 27 healthy volunteers were enrolled in this retrospective study. Participants were evaluated for changes in anthropometric parameters, metabolic indexes, thyroid function, and leptin levels before and 12 months after surgery. Results: After RYGB, all of these patients experienced significant weight reduction and improved glucose control. Metabolic parameters were significantly ameliorated after surgery compared with baseline. Thyroid hormones including free triiodothyronine (FT3), free thyroxine (FT4), and thyroid-stimulating hormone (TSH) declined in parallel. Median (IQR) plasma leptin levels decreased from 33.7 ng/mL (17.9–63.1) to 10.3 ng/mL (4.0–18.5). Pearson correlation analysis showed that TSH was significantly positively correlated with body mass index, C-reactive protein (CRP), and leptin. Multiple stepwise linear regression indicated that leptin and CRP were independent factors affecting TSH. The β coefficients were 0.38 (p = 0.001) and 0.32 (p = 0.004), respectively. There was a significant positive correlation between ΔTSH and Δleptin (r = 0.33, p = 0.01). Conclusion: Decreased or normalized TSH levels after weight loss induced by RYGB might be mediated by the decline in leptin. There could be cross talk between adipose tissue and the HPT axis.
Community-Acquired Acute Kidney Injury as a Risk Factor of de novo Heart Failure Hospitalization
Authors: Tecson Kristen M. , Hashemi Helen , Afzal Aasim , Gong Timothy A. , Kale Parag , McCullough Peter A.
Published: May 2019

Objectives: Because patients with hospital-acquired acute kidney injury (AKI) are at risk for subsequent development of heart failure (HF) and little is known about the relation between community-acquired AKI (CA-AKI) and HF, we sought to determine if CA-AKI is a risk factor for incident HF hospitalization. Methods: We utilized Baylor Scott & White Health databases at the primary care and inpatient hospitalization levels to identify adults without a prior history of HF who had 2 or more serum creatinine measurements within 13 months in the primary care setting. We defined CA-AKI as a serum creatinine increase ≥0.3 mg/dL or ≥1.5 times the baseline for consecutive values within a 13-month period. We created a flag for de novo HF hospitalization at 90, 180, and 365 days following CA-AKI evaluation. Results: In the analyses, 210,895 unique adults were included, of whom 5,358 (2.5%) had CA-AKI. Those with CA-AKI had higher rates of comorbidities, higher rate of males (48 vs. 42%, p < 0.001), and were older (61.5 [50.3, 73.1] vs. 54.1 [42.8, 64.7] years, p < 0.001) than those who did not have CA-AKI. In total, 607 (0.3%), 833 (0.4%), and 1,089 (0.5%) individuals had an incident HF hospitalization in the 90, 180, and 365 days following the CA-AKI evaluation, respectively. After adjusting for demographic and clinical characteristics, patients with CA-AKI had >2 times the risk of de novo HF hospitalization compared with patients who did not have CA-AKI (90 days: 2.35 [1.83–3.02], p < 0.001; 180 days: 2.52 [2.04–3.13], p < 0.001; 365 days: 2.16 [1.77–2.64], p < 0.001). These multivariable models yielded strong predictive abilities, with the areas under the receiver-operating characteristic curve >0.90. Conclusion: After controlling for baseline and clinical characteristics, patients with CA-AKI were at approximately twofold the risk of de novo HF hospitalization (within 90, 180, and 365 days) compared with those who did not have CA-AKI. Hence, detecting CA-AKI may provide an opportunity for early intervention at the primary care level to possibly delay HF development.
Early and Mid‐Term Outcomes of Patients Undergoing Coronary Artery Bypass Grafting in Ischemic Cardiomyopathy
Authors: Jose Rajesh , Shetty Ashith , Krishna Neethu , Chathoth Vijisha , Bhaskaran Renjitha , Jayant Aveek , Varma Praveen Kerala
Published: May 2019

Background

Many observational studies and trials have shown that coronary artery bypass grafting improves the survival in patients with ischemic cardiomyopathy. However, these results are based on data generated from developed countries. Poor socioeconomic statuses, lack of uniformity in healthcare delivery, differences in risk profile, and affordability to access optimal health care are some factors that make the conclusions from these studies irrelevant to patients from India.

Methods and Results

One‐hundred and sixty‐two patients with severe left ventricular dysfunction (ejection fraction ≤35%) who underwent coronary artery bypass grafting from 2009 to 2017 were enrolled for this study. Mean age of the study population was 58.67±9.70 years. Operative mortality was 11.62%. Thirty day/in‐house composite outcome of stroke and perioperative myocardial infarction were 5.8%. The percentage of survival for 1 year was 86.6%, and 5‐year survival was 79.9%. Five‐year event‐free survival was 49.3%. The mean ejection fraction improved from 30.7±4.08% (range 18–35) to 39.9±8.3% (range 24–60). Lack of improvement of left ventricular function was a strong predictor of late mortality (hazard ratio, 21.41;CI4.33–105.95). Even though there was a trend towards better early outcome in off‐pumpCABG, the 5‐year survival rates were similar in off‐pump and on‐pump group (73.4% and 78.9%, respectively;Pvalue 0.356).

Conclusions

We showed that coronary artery bypass grafting in ischemic cardiomyopathy was associated with high early composite outcomes. However, the 5‐year survival rates were good. Lack of improvement of left ventricular function was a strong predictor of late mortality.
Response of Surface Wind Divergence to Mesoscale SST Anomalies under Different Wind Conditions
Authors: Foussard A. , Lapeyre G. , Plougonven R.
Published: May 2019

The response of the atmospheric boundary layer to mesoscale sea surface temperature (SST) is often characterized by a link between wind stress divergence and downwind SST gradients. In this study, an idealized simulation representative of a storm track above a prescribed stationary SST field is examined in order to determine in which background wind conditions that relationship occurs. The SST field is composed of a midlatitude large-scale frontal zone and mesoscale SST anomalies. It is shown that the divergence of the surface wind can correlate either with the Laplacian of the atmospheric boundary layer temperature or with the downwind SST gradient. The first case corresponds to background situations of weak winds or of unstable boundary layers, and the response is in agreement with an Ekman balance adjustment in the boundary layer. The second case corresponds to background situations of stable boundary layers, and the response is in agreement with downward mixing of momentum. Concerning the divergence of the wind stress, it generally resembles downwind SST gradients for stable and unstable boundary layers, in agreement with past studies. For weak winds, a correlation with the temperature Laplacian is, however, found to some extent. In conclusion, our study reveals the importance of the large-scale wind conditions in modulating the surface atmospheric response with different responses in the divergences of surface wind and wind stress.
Future Changes in Hail Occurrence in the United States Determined through Convection-Permitting Dynamical Downscaling
Authors: Trapp Robert J. , Hoogewind Kimberly A. , Lasher-Trapp Sonia
Published: May 2019

The effect of anthropogenically enhanced greenhouse gas concentrations on the frequency and intensity of hail depends on a range of physical processes and scales. These include the environmental support of the hail-generating convective storms and the frequency of their initiation, the storm volume over which hail growth is promoted, and the depth of the lower atmosphere conducive to melting. Here, we use high-resolution (convection permitting) dynamical downscaling to simultaneously account for these effects. We find broad geographical areas of increases in the frequency of large hail (35-mm diameter) over the United States, during all four seasons. Increases in very large hail (50-mm diameter) are mostly confined to the central United States, during boreal spring and summer. And, although increases in moderate hail (20-mm diameter) are also found throughout the year, decreases occur over much of the eastern United States in summer. Such decreases result from a projected decrease in convective-storm frequency. Overall, these results suggest that the annual U.S. hail season may begin earlier in the year, be lengthened by more than a week, and exhibit more interannual variability in the future.
Wind Direction Measurements on Moored Coastal Buoys
Authors: Malačič Vlado
Published: May 2019

Wind direction measurements from anchored floating objects (buoys) are disturbed by the movement of an agitated sea surface. This article describes corrected wind direction measurements that account for a rotated and tilted anemometer, in which the rotations around the Euler angles “roll,” “pitch,” and “yaw” are simultaneously measured on coastal buoy “Vida” in Slovenian waters of the Gulf of Trieste. The wind data analysis is composed of a short-term analysis during a 4-h summer storm and a long-term analysis of wind direction for an 8-yr period. In the short-term analysis, the time evolution of the spectral composition of the anemometer’s translation and wind speeds revealed the dominance of 3–4-s oscillations that are mostly caused by waves. Anemometer velocity may account for up to 5% of apparent wind speed. In the long-term analysis, wind direction measurements were validated against those from two other stations in the Gulf of Trieste, as well as from the Acqua Alta tower in front of the Venice lagoon; all three are located in Italian waters. Short-term analysis of a summer storm and long-term measurements from four stations show that correcting the wind direction with the buoy’s orientation accounts for about 10°–12° of the error in wind direction.
Where Women Make a Difference: Gender Quotas and Firms’ Performance in Three European Countries
Authors: Comi Simona , Grasseni Mara , Origo Federica , Pagani Laura
Published: May 2019

The authors study the effect of corporate board gender quotas on firm performance in France, Italy, and Spain. The identification strategy exploits the exogenous variation in mandated gender quotas within country and over time and uses a counterfactual methodology. Using firm-level accounting data and a difference-in-difference estimator, the authors find that gender quotas had either a negative or an insignificant effect on firm performance in the countries considered with the exception of Italy, where they find a positive impact on productivity. The authors then focus on Italy. Using a novel data set containing detailed information on board members’ characteristics, they offer possible explanations for the positive effect of gender quotas. The results provide an important contribution to the policy debate about the optimal design of legislation on corporate gender quotas.
A Novel Method to Enhance Dynamic Rhinoplasty Outcomes: Double “V” Carving for Alloplastic Grafts
Authors: Bai Shan-shan , Li Dong , Xu Liang , Duan Hui-chuan , Yuan Jie , Wei Min
Published: May 2019

Augmentation rhinoplasty is one of the most common plastic surgery procedures performed in Asia. Most Asian patients desire not only a natural-looking nose but also a nose with natural feel. Achieving such rhinoplasty outcomes with grafts has been a challenge for surgeons due to rigidity of grafting material. We propose a novel technique to address this limitation. A total of 200 healthy adult patients aged from 18 to 25 years were randomly chosen and classified into 5 groups: A, B, C, D, and control. Each group included 40 patients. The patients assigned to conventional grafting underwent rhinoplasty with L-shaped silicone prosthesis (group A) or expanded polytetrafluoroethylene (e-PTFE; group B), using traditional carving methods. The patients assigned to dynamic rhinoplasty underwent silicone (group C) or e-PTFE grafts (group D) using the modified double “V” method, which involves removing bilateral wedges from the graft to decrease rigidity. Patients in control group do not undergo the surgery. A 3-dimensional raster surface scanner was used to capture the images of the patients accurately and nasal mobility was measured. Subjective evaluations were carried out by a series of questionnaires asked to the patients. The angle α of nasal mobility was significantly lower in conventional grafting (23.09 [5.34] mm for silicone and 17.88 [4.96] mm for e-PTFE) versus the “V” carving (30.53 [3.76] mm for silicone and 23.77 [4.53] mm for e-PTFE; P < .05). The double “V” carving method is a simple, effective, and practical method for improving dynamic nasal outcomes in patient undergoing augmentation rhinoplasty.
I Know (What) You Are, But What Am I? The Effect of Recategorization Threat and Perceived Immutability on Prejudice
Authors: Fritzlen Katherine A. , Phillips Joy E. , March David S. , Grzanka Patrick R. , Olson Michael A.
Published: May 2019

Learning one is similar to a stigmatized group can threaten one’s identity and prompt disassociation from the group. What are the consequences of learning of a similarity to a stigmatized group when that similarity implies possible recategorization into the group? We investigated how learning of an immutable, recategorization implying similarity with an outgroup affects implicitly and explicitly assessed prejudice. In Study 1, White participants who believed they had above average genetic overlap with African Americans showed decreased prejudice on implicit but not explicit measures. In Study 2, straight/heterosexual participants who were led to believe they exhibited some same-sex attraction showed reduced implicitly assessed prejudice, but only if they believed sexual orientation was biologically determined. Thus, learning of an identity-implying similarity with an outgroup can reduce implicit prejudice if that group membership is believed to be immutable. Theoretical and practical implications are discussed.
Best Practices in Operating High Frequency Metro Services
Authors: Canavan Shane , Barron Alexander , Cohen Judith , Graham Daniel J. , Anderson Richard J.
Published: May 2019

Most metro rail systems worldwide are facing increasing demand and the need to deliver additional capacity in key corridors. Although total capacity reflects the combination of train capacity and frequency, increasing frequency is the primary strategy to increase capacity on existing lines where infrastructure is fixed. Higher frequencies also increase efficiency, by attracting more passengers and making existing journeys faster, thereby making better use of expensive rail infrastructure and increasing both metro revenues and wider economics benefits to the cities they serve. This paper is based on a study conducted for the Community of Metros, a worldwide group of metro systems, which surveyed 17 high frequency lines. The paper first documents the characteristics of high frequency lines [with 25 trains per hour (tph) or more defined as “high frequency” and 30 tph or more as “very high frequency”] and presents the various constraints to higher frequency operations, including how they interact and the various possible solutions. Five main categories of constraints were identified, relating to signaling and train control, station and train crowding, fleet, terminal turnarounds, and service complexity. To achieve the highest frequencies, it is essential for metro systems to take a holistic approach and identify not only the immediate constraints but also secondary and tertiary constraints that may prevent the full benefits of improvements from being realized. This paper provides guidance to those operating, funding, planning, and designing metro systems in how to maximize frequency and thereby deliver greater benefits to riders, transit agencies, and stakeholders.
Analysis of Psychological Influences on Navigation Use While Driving Based on Extended Theory of Planned Behavior
Authors: Yao Xianglin , Wu Yiping , Liu Hao , Zhao Xiaohua , Bian Yang , Qu Weina
Published: May 2019

As GPS navigation systems become more powerful, they offer the convenience of more efficient travel, and the use of such navigational aids while driving is now prevalent. Numerous issues still exist during actual use, however, such as incomprehensibility and inaccuracy of voice navigation prompts. The majority of studies have focused on humanized design and the influence on driving behavior of GPS navigation systems, while the psychological factors underlying drivers’ decisions to use them have received little attention. This study employs the extended theory of planned behavior (TPB) to investigate the psychological factors that influence drivers’ use of GPS navigation systems, including the additional variables of navigation involvement, navigation information quality, and distraction perception. Independent t-tests revealed that female, non-professional, novice, and highly educated drivers were more likely to use navigation systems. Factors analysis proved the extended TPB questionnaire to be valid and reliable. Structural equation modeling showed that attitude (0.19), subjective norms (0.14), perceived behavioral control (0.29), navigation involvement (0.36), and information quality (0.16) significantly influenced drivers’ intentions on the use of navigation. However, distraction perception (–0.05) had no significant influence. These findings demonstrate the need for navigation systems which serve drivers better. For navigation system manufacturers, the humanized design should be strengthened. For highway transportation agencies, more consistent designs for road signs are needed to improve the cooperativity between navigation and traffic signs.
Evaluation of Transportation System Resilience in the Presence of Connected and Automated Vehicles
Authors: Ahmed Shofiq , Dey Kakan , Fries Ryan
Published: May 2019

Large-scale natural disasters challenge the resilience of the surface transportation system. The objective of this research was to develop a resilience model of the surface transportation system with a mixed-traffic environment and considering varying Connected and Automated Vehicle (CAV) penetration scenarios. As deployment of CAVs is expected to improve traffic operations, a resilience model was developed in this research to evaluate the resilience performance of a transportation system with several CAV penetration levels (0%, 25%, 50%, 75%, and 100%) for a given budget and recovery time. The proposed resilience quantification model was applied on a roadway network considering several disaster scenarios. The network capacity in relation to trips at any phase of disaster was compared with the pre-disaster trips to determine the system resilience. The capacity variation and the travel time variation were also estimated. The analysis showed that the resilience of the transportation system improved with CAVs in relation to travel time and capacity improvement. Link travel times were significantly improved by higher CAV penetration rate. The findings also suggested that higher penetration of CAVs (i.e., 50% or more) increased the recovery costs. For example, the recovery costs needed for medium and large-scale disasters were 50% and 90% higher, respectively, compared with the recovery costs for a small-scale disaster. These higher costs were primarily for the repair and replacement of intelligent infrastructure required to support the operation of CAVs.
Special Education Preservice Teachers, Intersectional Diversity, and the Privileging of Emerging Professional Identities
Authors: Boveda Mildred , Aronson Brittany A.
Published: May 2019

Intersectional competence captures educators’ awareness of how sociocultural markers of difference simultaneously intersect within the P-12 school context. This article presents findings from a larger mixed-methods sequential exploratory study that established, in part, the theoretical and qualitative basis for validating the Intersectional Competence Measure. The questions asked during the qualitative phase were developed after a review of the literature on intersectionality in special education, collaborative teacher education, and existing measures of preservice teachers’ understanding of diversity. This analysis focuses on the responses of 12 culturally and linguistically diverse special education preservice teachers. When speaking about P-12 students, they tended to position themselves as special educators, privileging their emerging professional identities. They expressed the important role that teacher education played in developing an understanding of sociocultural differences. The participants discussed the complexities of intersecting identities when speaking about their own educational experiences and when considering discriminatory attitudes that persist within minoritized communities.
Time Perspective and Career Decision-Making Self-Efficacy: A Longitudinal Examination Among Young Adult Students
Authors: Kvasková Lucia , Almenara Carlos A.
Published: May 2019

This longitudinal study examined the relationship between Zimbardo time perspectives (TPs) and career decision-making self-efficacy (CDMSE). In total, 1,753 young adults participated in the longitudinal study. For the present study, we selected only participants who were students and provided information on TPs, CDMSE, and sociodemographic characteristics ( n = 492, M = 22.97 years, SD = 1.32, 82.9% women). The results of multilevel modeling showed that future orientation and present-hedonistic TPs were positively related to CDMSE, whereas present-fatalistic and past-negative TPs were negatively related to CDMSE. These findings indicate that besides the beneficial effect of widely studied future TP, the negative role of past-negative and present-fatalistic TPs should be considered in connection with the career development of emerging adults.
Paradigm Shifts in States’ Assessment Accessibility Policies: Addressing Challenges in Implementation
Authors: Larson Erik D. , Thurlow Martha L. , Lazarus Sheryl S. , Liu Kristin K.
Published: May 2019

Providing accessibility features and accommodations to students with disabilities has been recognized as an important way to improve access to instruction and to assessments. This recognition was in large part a result of a paradigm shift that saw students with disabilities being held to the same standards on state assessments as their peers without disabilities. This article describes this paradigm shift of the 1990s, putting into context a more recent paradigm shift that, since 2009, has pushed the field to think about access to instruction and assessments for all students. It reviews recent research on making decisions about accessibility features and accommodations for all students, including those with disabilities, and then identifies implications for policy and research.
Association rule mining using chaotic gravitational search algorithm for discovering relations between manufacturing system capabilities and product features
Authors: Kou Zhicong
Published: May 2019

An effective data mining method to automatically extract association rules between manufacturing capabilities and product features from the available historical data is essential for efficient and cost-effective product development and production. This article proposes a chaotic gravitational search algorithm–based association rule mining method for discovering the hidden relationship between manufacturing system capabilities and product features. The extracted rules would be utilized to predict capability requirements of various machines for the new product with different features. We use two strategies to incorporate chaos into gravitational search algorithm: one strategy is to embed chaotic map functions into the gravitational constant of gravitational search algorithm; the other is to use sequences generated by chaotic maps to substitute random numbers for different parameters of gravitational search algorithm. In order to improve the applicability of chaotic gravitational search algorithm–based association rule mining, a novel overlapping measure indication is further proposed to eliminate those unuseful rules. The proposed method is relatively simple and easy to implement. The rules generated by chaotic gravitational search algorithm–based association rule mining are accurate, interesting, and comprehensible to the user. The performance comparison indicates that chaotic gravitational search algorithm–based association rule mining outperforms other regular methods (e.g. Apriori) for association rule mining. The experimental results illustrate that chaotic gravitational search algorithm–based association rule mining is capable of discovering important association rules between manufacturing system capabilities and product features. This will help support planners and engineers for the new product design and manufacturing.
Long Term Results of Charnley Low-Friction Arthroplasty a Thirteen-Year Average Follow-Up Study
Authors: Stringa G. , Muria G.V. , Di Marcucci M. , Pitto R.P.
Published: May 2019

Of the first 127 consecutive patients who had had a Charnley total hip replacement at the First Orthopaedic Clinic, University of Florence, between 1970 and 1977, 74 (76 hips) were re-evaluated eleven to eighteen years post-operatively by clinical examination and roentgenograms.

In this group we identified 8 failures (3 mechanical loosening and 5 septic loosening). All failed cases were revised.

At 13 years average follow-up, the incidence of radiological aseptic loosening was 19.1% for the acetabular component and 17.6% for the femoral component; nevertheless in most of these cases, the clinical status was excellent or good.

Acetabular component wear was found to be a significant problem.
Morphology and Biomechanics of the Hip. Study I: The Normal Hip
Authors: Specchiulli F. , Laforgia R. , Nitti L. , Pellicani N. , Savino G. , Mastrosimone N. , Solarino G.
Published: May 2019

With the aim of defining the roentgenographic characteristics of a “normal” hip - meaning an articulation able to fully respond to static and dynamic stress without wear, we examined 60 hips of people over 70 years old from a population of Southern Italy. The parameters considered were: width of WBS, inclination of WBS, height of Gothic Arch, width of Gothic Arch, angle of aperture of Gothic Arch, a angle of Gothic Arch, diameter of femoral head, CE angle of Wiberg, neck-shaft angle, offset, angle of aperture of spherichal sector (SS), surface area of SS, volume of SS, radius of the spherical bowl, height of the spherical bowl, distance from the “tear drop” image of the fundus acetabuli. The main findings are: a) the WBS is horizontal; b) the gothic arch is orthogonal to the WBS; c) the spherical sector presents wide individual oscillations; d) the female hip has specific characteristics, being mainly smaller.
Arthroplasty Revision for Aseptic Failure. Our Experience
Authors: Surace A. , Pietrogrande L. , Sartoris M.
Published: May 2019

35 cases of arthroplasty revision are reviewed with mean follow-up time of 56 m. (range 24 to 107), by clinical and radiographic study. The results were satisfactory, having only one case of secondary failure (2.8%), also in comparison with other studies. The reason of this probably lies in the adaptability of our technique: in fact we use without preconcepts both cement and cementless fixations with many types of stems and cotyles; this allows us to obtain a stable fixation also taking in consideration the bone characteristics of each case.
Centralization of the Femoral Component in THR. Biomechanical Considerations and Method
Authors: Krakovits G. , Sass L.
Published: May 2019

The correct implacement of the femoral component is decisive in the longevity of the total hip replacement (THR). The stem has to be placed along the anatomical axis of the femur and accomodated to the internal wall of the femoral canal to prevent tilting, subsidence, torsion movement and its clinical disadvantages. The author discusses the biomechanical consideration as well as the operative method.
Medium-Term Clinical and Radiological Results of the Uncemented Total Hip Prosthesis PM
Authors: Reichelt A. , Botterer H.
Published: May 2019

Medium term results of 114 cementfree hip joint endoprostheses type PM implanted until mid - 1986 are presented. The clinical evaluation was based on the methods of Merle d'Aubigné and Harris.

The mean Merle d'Aubigné score increased from 9.15 to 13.95 points and the Harris score from 44.13 to 75.60 points.

After a mean in-situ period of 7.6 years only 35.96% of the operated hips were totally painfree. Twenty-seven prostheses (23.68%) did not need any support when walking (5.62% pre-op). Patients with forty-eight prostheses (42.11%) were able to walk without limitation (18.42% pre-op.). Of the operated hip joints 93.9% were judged subjectively as improved. Eighty-four patients were very satisfied (73.7%), twenty-seven were fairly satisfied (23.6%) and three were not at all satisfied (2.6%).

Radiographically, 61% of the stems showed a change of position, whereas only 8% of the acetabular components shifted. In 71.4% of the cases, a radiolucent line around the stem was seen in zone 14. Approximately two thirds of the cups showed this radiolucency. Atrophy of the cortex was noticed in 37.8% of the cases in zone 6. Periosteal reactions appeared only around the tip of the femoral shaft (26.5%).

Seventy-eight femora showed a bony consolidation around the stem-tip.

Ectopic ossifications were detected at seventy-three joints altogether. In three cases, Brooker-stage IV was reached.

The statistical evaluation showed a low significant correlation between atrophy of cortex in various zones and appearance of pain.

The survival-analysis showed for primary implanted PM prostheses a survival rate of 90.5% (Confidence interval 86.3%-94.6%) after a five year period and of 73.3% (Confidence interval 60.3%-86.4%) after a ten year period in situ.
The Snapping Hip
Authors: Pećina M. , Bojanić I. , Hašpl M.
Published: May 2019

The snapping hip syndrome is a symptom complex characterized by an audible snapping sensation usually, but not necessarily, associated with hip pain during certain movements of the hip joint. A number of different aetiologies, both intraarticular and extraarticular have been described. Intraarticular causes for the snapping hip include loose bodies, osteocartilaginous exostosis, osteochondromatosis and subluxation of the hip. Extraarticular causes for the snapping hip are described in this paper (Tab. I). Due to localization of the causes, three different syndromes are described: the medial (internal), the lateral (external), and the posterior snapping hip syndrome. The authors describe diagnosis, differential diagnosis, and treatment of these syndromes. Successful results in the treatment of lateral snapping hip syndrome with the iliotibial tract fenestration method are also reported.
Snapping Hip: Anatomy, Clinical Features and an Effective Operation
Authors: Donell S.T. , Bradish C.F. , Phillips H.
Published: May 2019

A new operation for treating snapping of the hip due to the vertical fibres of the iliotibial tract catching on the greater trochanter is described. A “V”-shaped proximally based flap of fascia lata that divides the vertical fibres of the iliotibial is rotated anteriorly. It preserves the function of the iliotibial tract by maintaining its integrity and length. It preserves the function of the gluteus maximus, and covers the greater trochanter with soft tissue; the muscle fibres of the gluteus maximus. The results of the operation in ten patients with eleven affected hips are presented. There was one minor wound infection, otherwise all patients were cured of pain and snapping. All patients had a negative Trendelenburg test at a minimum of two years after the operation.
A Clinical and Electromyographic Review of the Lateral and Postero-Lateral Approaches to the Hip after Prosthetic Replacement
Authors: Moreschini O. , Giordano M. C. , Margheritini F. , Chiatti R.
Published: May 2019

The Authors carried out a clinical and electromyographic study on two groups of patients undergoing total hip replacement with two different surgical approaches, evaluating the evolution of the clinical results at three and fifteen months after operation and comparing the same to the electromyographic results of the muscles involved during surgical exposure.

They found differences in the post-operative functional changes in the two groups of patients and the reliability of the clinical and electromyographic results in the critical evaluation of the two different approaches.
A Practical Screener for Deep Vein Thrombosis after Total Hip Replacement
Authors: McNally M.A. , Crone M.D. , Mollan R.A.B.
Published: May 2019

A new non-invasive screener for the detection of proximal deep vein thrombosis was evaluated in two consecutive series of patients undergoing primary total hip replacement. The system, which utilises computerised strain gauge venous occlusion plethysmography, was simple to use and allowed serial screening of large numbers of patients without complication. Comparison with venography in 112 patients gave a specificity of 96% (106/110) and a sensitivity of 100% (2/2) for clinically important proximal DVT.

Based on this study, a larger management study was performed. After total hip replacement, 516 patients were serially screened and all were followed to at least four months (mean 7.6 months) from surgery. Venography was only requested after a positive screening test. The screener correctly identified proximal and major calf thrombi in this group allowing early treatment. There were no fatal pulmonary emboli.

This initial assessment suggests that computerised strain gauge plethysmography may be useful in identifying those patients with silent venous thrombosis after total replacement.
Exploiting the distance between conflicting norms: Female rural-to-urban migrant workers in Shanghai negotiating stigma around singlehood and marriage
Authors: Ip Penn Tsz Ting , Peeren Esther
Published: May 2019

On the basis of fieldwork conducted in Shanghai, this article explores how Chinese rural-to-urban migrant women cope with the stigmatization they face as a result of conflicting gender norms regarding singlehood and marriage in their home communities and in Shanghai. We focus on how migrant women legitimate their relationship status as single, married or having a boyfriend in relation to these norms. Our findings reveal that migrant women, while not rejecting existing norms outright, actively pre-empt or counteract the stigmatization of their singlehood or of the fact that they live apart from their husband using coping strategies that exploit their position in between the urban context and their rural hometowns in intricate ways.