bluuebunny/crossref_metadata_2025 huggingface dataset:
Laparoscopic ureteroneocystostomy in iatrogenic injuries of ureter after gynecoloc operations
Authors: Guliev Bakhman Gidayatovich
Published: February 2016

The Objective. To evaluate outcomes of laparoscopic ureteroneocystostomy in patients with iatrogenic strictures of distal part of ureter, caused by gynecologic interventions. Materials and methods. From 2010 to 2014, 10 female patients with iatrogenic injuries of distal part of ureter underwent laparoscopic ureteroneocystostomy. Seven had previous open or laparoscopic hysterectomy, two - removal of endometrioid nodes and 1 - ovarial resection. Surgery was performed using transperitoneal approach with inserting of 4 trocars. Ureter was mobilized and transected above the stricture with subsequent extravesical implantation to the bladder. Results. We had no conversion cases and in all patients ureteroneocystostomy didn’t fail. In 3 cases intervention included ureteroneocystostomy with psoas-hitch, in 2 - Boari flap and in 5 - direct anastomosis of ureter with bladder. Average surgery time was 140 min (ranged between 110 and 215min), average blood loss was estimated as 160 ml (125-240 ml). Cystoureteral reflux was noted in 2 patients. Conclusion. Laparoscopic ureteroneocystostomy is less invasive and reliable surgical treatment modality efficient in cases of iatrogenic ureteral injuries due to gynecological interventions.
Clinical and bacteriological feature postpartum purulent-inflammatory diseases
Authors: Korobkov Nikolay Alexandrovich
Published: February 2016

This review summarizes the literature of recent years and the results of their research on the etiology of postpartum infection at this stage. Highlighted aspects of complications of pregnancy, childbirth and the postpartum period due to the action of opportunistic organisms and obligate pathogens.
Pathogenesis of Trousseau’s syndrome
Authors: Vorobev Alexander Viktorovich , Makatsaria Alexander Davidovich , Chabrov Andrey Mikhailovich , Savchenko Alexander Anatol’evich
Published: February 2016

Malignancies and thrombosis have common pathogenetic features that was shown by A. Trousseau in 1865. There is now no doubt that the cancer patients occur much more frequently thromboembolism, and migratory venous thrombosis is a manifestation of paraneoplastic syndrome in cancer patients. In general, any manifestation of thrombohemorrhagic complications in cancer patients called Trousseau’s syndrome. While thrombotic complications such as venous thromboembolism are most frequent in cancer patients, may also experience severe bleeding symptoms due to systemic coagulopathies, including disseminated intravascular coagulation, haemolytic thrombotic microangiopathy, and hyperfibrinolysis. The basis of the pathophysiology of Trousseau’s syndrome, except the classic triad of Virchow, is overproduction of tissue factor (TF), the main initiator of extrinsic coagulation pathway. Thus a significant release of microparticles from tumor cells bearing tissue factor is critical not only for the formation of a blood clot, but the growth and progression of tumors. Tumor cells activate the coagulation cascade or fibrinolysis system, providing conditions for its further spread, stimulation of angiogenesis, increased vascular permeability, which in turn promotes metastasis.
Bologna Process in Ukraine: The Decade Anniversary
Authors: Nikolaeva Sofiya
Published: February 2016

The article presents the results of the analysis of achievements and shortcomings of Ukraine in joining the European Higher Education Area. For the research implementation the ten-year period of the Bologna process in Ukraine is divided into four stages (steps): step 1 – from Bergen to London; step 2 – from London to Leuven; step 3 – from Leuven to Bucharest; step 4 – from Bucharest to Yerevan. Within each of the stages the appropriate investigation methods are used. In general, the following techniques are applied: review of documents and publications; survey of students, PhD students and professors; observation of the educational process and reflection; testing of bachelors, masters and PhD students, data collection; overview of the official sites of Ukrainian universities. For each of the stages identified pros and cons are considered. It has been concluded that per decade Ukraine has achieved a lot, but many of the key issues need solution.
Analysis of System of Personages and Composition of «The Double, or my Evenings in Malorossia» by А. Pogorelsky
Authors: Vorova T.P.
Published: February 2016

Antony Pogorelsky (1787-1836) (the pseudonym of А. А. Perovsky) was one of the writers active in the early stages of Russian romantic prose, when romanticism, with its new artistic outlook based on rapt attention towards and keen interest in the inner world of feelings and emotions of its literary heroes, replaced the literary movement of sentimentalism with its orientation toward the ideas of the enlightenment. The current article is aimed at the investigation of the first book by A. Pogorelsky «The Double, or My Evenings in Malorossia», the novelty of which lies not only in the fact that the book is directly correlated with the traditions of West European romanticism (which was undoubtedly well-known to the writer), but also in the introduction of a new principle of composition into Russian literature (the cycle of several stories united through dialogic framing), which was the first experiment of this kind in the Russian literary environment and would soon become one of the favourite techniques of other Russian romanticists
An Historical - Didactic Introduction to Algebra
Authors: Di Sia Paolo
Published: February 2016

In this Paper we Consider a Teaching Educational Introduction to Ideas and Concepts of Algebra. we Follow a Historical Path, Starting by the Egyptians and the Babylonians, Passing through the Greeks, the Arabs, and the Figure of Omar Khayyām, for Coming to the Middle Age, the Renaissance, and the Nineteenth Century. Interesting and Peculiar Characteristics Related to the Different Geographical Areas in which Algebra has Developed are Taken into Account. the Scientific Rigorous Followed Treatment Allows the Use of the Paper Also as a Pedagogical Introduction to this Fundamental Branch of Current Mathematics.
Pedagogical Technology of the Future Masters of Economics Cross-Cultural Tolerance Formation
Authors: Yerastova-Mikhalus Inna
Published: February 2016

The aim of the article is to reveal the essence of notion “pedagogical technology”; to determine its role in achievement of the planned results connected with the future masters of economics cross-cultural tolerance formation; to cover different approaches to understanding this problem; to give detailed description of the pedagogical technology of the future masters of economics cross-cultural tolerance formation that corresponds to the determined pedagogical objectives. The main stages of the pedagogical technology (motivational and goal-oriented, cognitive and transformative, value and reflexivity formation) at the micro-and macro-level were analyzed. The system of teaching tools with the detailed description of the methods, tasks and organizational forms at every stage of the pedagogical process of cross-cultural tolerance formation is given as well as additional tasks for the extended learning. The importance of the compliance with the suggested stages for the successful realization of the determined pedagogical goals is emphasized.
Quality Assurance as the Driver of Institutional Transformation of Higher Education in Ukraine
Authors: Krasovska Olena Yu.
Published: February 2016

In the context of change of higher education in Ukraine, the issue of transformation of institutional relations and subjects of educational space has been put forward. The new paradigm of higher education is based on European values ​​and focused on the integration of Ukraine into the European Higher Educational Area. The transformation of higher education is influenced by many institutional factors. The processes of quality assurance as one of the drivers of institutional transformation of Ukrainian higher education system is researched. The preconditions of the institutional transformation of Ukrainian higher education is analyzed; new approaches and principles of quality assurance in the emerging new institutional environment of higher education and integration into the European educational space are defined in the article.
Peculiarities of Russian Context in O. Wilde’s Play “Vera”
Authors: Posudiyevska Olga
Published: February 2016

At the end of the XIX century the interest of British intellectual circles to the Russian Empire was intensified due to the latest events – the appearance of Nihilists on the Russian political arena. British intellectuals, especially those contradicting Victorian social and moral norms, were inspired by the new type of hero-nihilist – a romantic highly-spiritual revolutionary, struggling for freedom, which was created in their imagination mostly due to Turgenev’s works and the lawsuit of Vera Zasulich, widely discussed in European press.This study concentrates on the analysis of the first play by Oscar Wilde Vera, dedicated to the Russian topic, which seems at first sight a naïve melodrama with confusion of historical events and features of the Russian social life. The peculiarities of Wilde’s perception of Russian reality, as well as literary devices used for creating Russian background, are analyzed. Special attention is paid to the tradition of depicting a mysterious and exotic Russia in English literature since the XVI century, followed by Wilde. The writer uses a number of standard clichés presenting his “Russia” as a far-away country with eternal frost, tyrannical government, poor and savage people, fully obedient to the cruel ruler.However, as the researcher concludes, Wilde didn’t aim at making a narration about real struggle between czarist regime and the Nihilists in Russia. The future leader of the aestheticism turns to Russian environment as an “another” place – a location, being unusual for an Englishmen, where the writer expects to find high feelings and lofty ideals, spiritual aims and moral values which couldn’t exist in pragmatic Victorian society. Wilde’s “Russia” is presented as an exotic, half-fictional reality, created mostly by the author’s imagination as proper surroundings for evolution of the romantic conflict between the tyrannical Czar and the Nihilists. However, this conflict becomes a spiritual battle of cynical and pragmatic worldview with high spiritual and moral ideals, the aesthetic embodiment of the eternal struggle between the good and the evil, soul chastity and sin.
A Decision Support System For Integration Of Vendor Selection Task
Authors: Tullous Raydel , Utecht Richard Lee
Published: February 2016

The purpose of this paper is to illustrate the usefulness of a particular decision support system, the Analytic Hierarchy Process (AHP), for developing and implementing integrated procurement systems. The purchasing decision support system (PDSS) proposed in this paper provides each participant involved in the purchasing process with a procedure to communicate their preferences and the reasons for those preferences. All of the participants preferences may be aggregated to determine an overall preference, or in some cases, the results may simply be used to gain a better understanding of the values the individual place on various attributes.
Orthopaedic Patient Information on the World Wide Web
Authors: Cassidy John Tristan , Baker Joseph F.
Published: February 2016

Background:

Patients increasingly use the Internet to research health-related issues. Internet content, unlike other forms of media, is not regulated. Although information accessed online can impact patients’ opinions and expectations, there is limited information about the quality or readability of online orthopaedic information.

Methods:

PubMed, MEDLINE, and Google Scholar were searched using anatomic descriptors and three title keywords (“Internet,” “web,” and “online”). Articles examining online orthopaedic information from January 1, 2000, until April 1, 2015, were recorded. Articles were assessed for the number of reviewers evaluating the online material, whether the article examined for a link between authorship and quality, and the use of recognized quality and readability assessment tools. To facilitate a contemporary discussion, only publications since January 1, 2010, were considered for analysis.

Results:

A total of thirty-eight peer-reviewed articles published since 2010 examining the quality and/or readability of online orthopaedic information were reviewed. For information quality, there was marked variation in the quality assessment methods utilized, the number of reviewers, and the manner of reporting. To date, the majority of examined information is of poor quality. Studies examining readability have focused on pages produced by professional orthopaedic societies.

Conclusions:

The quality and readability of online orthopaedic information are generally poor.

Clinical Relevance:

For modern practices to adapt to the Internet and to prevent misinformation, the orthopaedic community should develop high-quality, readable online patient information.
Comparison of Whole-Blood Metal Ion Levels Among Four Types of Large-Head, Metal-on-Metal Total Hip Arthroplasty Implants
Authors: Hutt Jonathan , Lavigne Martin , Lungu Eugen , Belzile Etienne , Morin François , Vendittoli Pascal-André
Published: February 2016

Few studies of total hip arthroplasty (THA) implants with a large-diameter femoral head and metal-on-metal design have directly compared the progression of metal ion levels over time and the relationship to complications. As we previously reported, 144 patients received one of four types of large-diameter-head, metal-on-metal THA designs (Durom, Birmingham, ASR XL, or Magnum implants). Cobalt, chromium, and titanium ion levels were measured over five years. We compared ion levels and clinical results over time. The Durom group showed the highest levels of cobalt (p ≤ 0.002) and titanium ions (p ≤ 0.03). Both the Durom and Birmingham groups demonstrated significant ongoing cobalt increases up to five years. Eight patients (seven with a Durom implant and one with a Birmingham implant) developed adverse local tissue reaction. Six Durom implants and one Birmingham implant required revision, with one pseudotumor under surveillance at the time of the most recent follow-up. We found that ion generation and related complications varied among designs. More concerning was that, for some designs, ion levels continued to increase. Coupling a cobalt-chromium adapter sleeve to an unmodified titanium femoral trunnion along with a large metal-on-metal bearing may explain the poor performances of two of the designs in the current study.

Level of Evidence:

Therapeutic Level II. See Instructions for Authors for a complete description of levels of evidence.
Particle-Induced Osteolysis Is Mediated by TIRAP/Mal in Vitro and in Vivo
Authors: Bechtel Christopher P. , Gebhart Jeremy J. , Tatro Joscelyn M. , Kiss-Toth Endre , Wilkinson J. Mark , Greenfield Edward M.
Published: February 2016

Background:

Proinflammatory signaling by toll-like receptors (TLRs) likely contributes to biologic responses to wear particles causing aseptic loosening. We recently reported associations with aseptic loosening in patients with polymorphisms in the locus encoding an adapter protein specific for TLR-2 and TLR-4 known as toll/interleukin-1 receptor domain-containing adapter protein/MyD88 adapter-like (TIRAP/Mal). To directly examine the contribution of TIRAP/Mal, we tested the hypothesis that TIRAP/Mal deficiency reduces the activity of wear particles. Signaling by TLR-2 and TLR-4 through TIRAP/Mal can be activated by bacterial pathogen-associated molecular patterns (PAMPs) such as lipopolysaccharide or endogenous alarmins. To distinguish between those possibilities, we tested the hypothesis that the effects of TIRAP/Mal depend on the adherence of bacterial PAMPs to the particles.

Methods:

In vitro mRNA levels and secretion of tumor necrosis factor-α, interleukin (IL)-1β, and IL-6 were measured after incubating wild-type and TIRAP/Mal−/−macrophages in the presence or absence of titanium particles with adherent bacterial debris, so-called endotoxin-free particles, or particles with adherent lipopolysaccharide. In vivo osteolysis was measured after implanting titanium particles on the calvaria of wild-type and TIRAP/Mal−/−mice.

Results:

TIRAP/Mal deficiency significantly inhibited the activity of titanium particles with adherent bacterial debris to stimulate in vivo osteolysis and in vitro cytokine mRNAs and secretion. Those effects are dependent on adherent PAMPs because removal of >99% of the adherent bacterial debris from the particles significantly reduced their activity and the remaining activity was not dependent on TIRAP/Mal. Moreover, adherence of highly purified lipopolysaccharide to the endotoxin-free particles reconstituted the activity and the dependence on TIRAP/Mal.

Conclusions:

TIRAP/Mal deficiency reduces inflammatory responses and osteolysis induced by particles with adherent PAMPs.

Clinical Relevance:

Our results, coupled with the genetic associations between aseptic loosening and polymorphisms within the TIRAP/Mal locus, support TLR signaling through TIRAP/Mal as one of the factors that enhances the activity of wear particles and further support the hypothesis that bacterial PAMPs likely contribute to aseptic loosening in a subset of patients.
Predicted and Observed Evolution of Produced-Brine Compositions and Implications for Scale Management
Authors: Hu Yisheng , Mackay Eric , Ishkov Oleg , Strachan Alistair
Published: February 2016

Produced water was sampled and measured repeatedly during production from an offshore field, and an extensive brine-chemistry data set was developed. Systematic analysis of this data set enables an in-depth study of brine/brine and brine/rock interactions occurring in the reservoir, with the objective of improving the prediction and management of scale formation, along with improving its prevention and remediation.

A study of the individual-ion trends in the produced brine by use of the plot types developed for the reacting-ions toolkit (Ishkov et al. 2009) provides insights into the components that are involved in in-situ geochemical reactions as the brines are displaced through the reservoir, and how the precipitation and dissolution of minerals and the ion-exchange reactions occurring within the reservoir can be identified. This information is then used to better evaluate the scale risk at the production wells.

A thermodynamic prediction model is used to calculate the risk of scale precipitation in a series of individual produced-water samples, thus providing an evaluation of the actual scaling risk in these samples, rather than the usual theoretical estimate, on the basis of the endpoint formation- and injection-brine compositions and the erroneous assumption that no reactions in the reservoir impact the produced-water composition. Nonetheless, the usual effects of temperature, pressure, and brine composition are accounted for in these calculations by use of classical thermodynamics. The comparison of theoretical and actual results indicates that geochemical reactions taking place in this given reservoir lead to ion depletion, which greatly reduces the severity and potential for scale formation. However, ion-exchange reactions are also observed, and these too affect the scale risk and the effectiveness of scale inhibitors in preventing deposition.

Additionally, comprehensive analysis by use of a geochemical model is conducted to predict the evolution of the produced-brine compositions at the production wells and to test the assumptions about which in-situ reactions are occurring. A good match between the predictions from this geochemical model and the observed produced-brine compositions is obtained, suggesting that the key reactions included in the geochemical model are representative of actual field behavior. This helps to establish confidence that the model can be used as a predictive tool in this field.
Design and Analysis of Leak-Testing Methodology for Gas Lift Valves
Authors: Rocha-Valadez T.. , Hasan A. R. , Mannan M. S. , Kabir C. S.
Published: February 2016

Properly operating gas lift valves (GLVs) allow annular gas to flow into the tubing and prevent any backflow. However, erosion, corrosion, and other effects may cause a GLV to leak, thereby posing a serious safety issue. Suspected leaking GLVs are often retrieved for inspection to address safety issues. Proactive testing is a way to minimize costly interventions. Accordingly, nonintrusive test procedures have emerged. For example, tests entailing monitoring of annular transient-pressure response can establish a GLV's integrity by avoiding valve retrieval for inspection.

This study details the development of a forward model that helps design methodology for GLV testing. The model recommends drawing down the annular gas to develop a positive pressure differential to allow fluid flow from the tubing into the annulus through the suspected GLV. This drawdown (DD) is followed by a pressure-buildup (BU) test. These pressure-transient tests allow the determination of the integrity and extent of GLV damage. The forward model also allows the estimation of the time needed for each segment of the transient-test sequence, thereby helping to schedule such tests at a certain operational frequency.
The Fisher Grade in predicting a degree of cerebral vasospasm in patients after intracranial aneurysm rupture
Authors: Djilvesi Djula , Cigic Tomislav , Papic Vladimir , Horvat Igor , Karan Mladen , Vulekovic Petar
Published: February 2016

Background/Aim. Intracranial aneurysms are pathological enlargement of the
wall of cerebral arteries. Intracranial aneurysms rupture is a dramatic event
with a significant morbidity and mortality. The Fisher Grade is widely
accepted in assessment of the extensiveness of aneurysmal subarachnoid
hemorrhage (aSAH) and the presence of other intracranial hemorrhage on the
computed tomography (CT) scan. Significant early complication of a aSAH may
be a cerebral vasospasm. The aim of this study was to determine the
relationship between the extensiveness of aSAH, assessed by the Fisher Grade
on admission, with the intensity of cerebral vasospasm in patients with
ruptured intracranial aneurysm. Methods. This prospective clinical study
included 50 patients with aSAH hospitalized at the Clinic of Neurosurgery,
Clinical Center of Vojvodina, Novi Sad, Serbia. All the patients underwent
256-layer cranial CT and CT angiography on admission and on the day 9. Based
on native CT scans, they were classified according to the Fisher Grade. On CT
angiography images, intensity of cerebral vasospasm was determined. Results.
On the basis of admission CT images, 24% of patients were classified into the
Fisher Grade group 2, while 34% and 42% were in the groups 3 and 4,
respectively. A positive correlation of the Fischer Grade on admission with
the intensity of cerebral vasospasm was established, but with no statistical
significance (? = 0.273, p = 0.160). Conclusion. This study showed that the
Fisher Grade is not significant in predicting the intensity of cerebral
vasospasm in patients hospitalized with intracranial aneurysm rupture.
Long-Acting C-Peptide and Neuropathy in Type 1 Diabetes: A 12-Month Clinical Trial
Authors: Wahren John , Foyt Howard , Daniels Mark , Arezzo Joseph C.
Published: February 2016

OBJECTIVE

Lack of C-peptide in type 1 diabetes may be an important contributing factor in the development of microvascular complications. Replacement of native C-peptide has been shown to exert a beneficial influence on peripheral nerve function in type 1 diabetes. The aim of this study was to evaluate the efficacy and safety of a long-acting C-peptide in subjects with type 1 diabetes and mild to moderate peripheral neuropathy.

RESEARCH DESIGN AND METHODS

A total of 250 patients with type 1 diabetes and peripheral neuropathy received long-acting (pegylated) C-peptide in weekly dosages of 0.8 mg (n = 71) or 2.4 mg (n = 73) or placebo (n = 106) for 52 weeks. Bilateral sural nerve conduction velocity (SNCV) and vibration perception threshold (VPT) on the great toe were measured on two occasions at baseline, at 26 weeks, and at 52 weeks. The modified Toronto Clinical Neuropathy Score (mTCNS) was used to grade the peripheral neuropathy.

RESULTS

Plasma C-peptide rose during the study to 1.8–2.2 nmol/L (low dose) and to 5.6–6.8 nmol/L (high dose). After 52 weeks, SNCV had increased by 1.0 ± 0.24 m/s (P < 0.001 within group) in patients receiving C-peptide (combined groups), but the corresponding value for the placebo group was 1.2 ± 0.29 m/s. Compared with basal, VPT had improved by 25% after 52 weeks of C-peptide therapy (Δ for combined C-peptide groups: −4.5 ± 1.0 μm, placebo group: −0.1 ± 0.9 μm; P < 0.001). mTCNS was unchanged during the study.

CONCLUSIONS

Once-weekly subcutaneous administration of long-acting C-peptide for 52 weeks did not improve SNCV, other electrophysiological variables, or mTCNS but resulted in marked improvement of VPT compared with placebo.
Type 2 Diabetes Genetic Predisposition, Obesity, and All-Cause Mortality Risk in the U.S.: A Multiethnic Analysis
Authors: Leong Aaron , Porneala Bianca , Dupuis Josée , Florez Jose C. , Meigs James B.
Published: February 2016

OBJECTIVE

Type 2 diabetes (T2D) is associated with increased mortality in ethnically diverse populations, although the extent to which this association is genetically determined is unknown. We sought to determine whether T2D-related genetic variants predicted all-cause mortality, even after accounting for BMI, in the Third National Health and Nutrition Examination Survey.

RESEARCH DESIGN AND METHODS

We modeled mortality risk using a genetic risk score (GRS) from a weighted sum of risk alleles at 38 T2D-related single nucleotide polymorphisms. In age-, sex-, and BMI-adjusted logistic regression models, accounting for the complex survey design, we tested the association with mortality in 6,501 participants. We repeated the analysis within ethnicities (2,528 non-Hispanic white [NHW], 1,979 non-Hispanic black [NHB], and 1,994 Mexican American [MA]) and within BMI categories (<25, 25–30, and ≥30 kg/m2). Significance was set at P < 0.05.

RESULTS

Over 17 years, 1,556 participants died. GRS was associated with mortality risk (OR 1.04 [95% CI 1.00–1.07] per T2D-associated risk allele, P = 0.05). Within ethnicities, GRS was positively associated with mortality risk in NHW and NHB, but not in MA (0.95 [0.90–1.01], P = 0.07). The negative trend in MA was largely driven by those with BMI <25 kg/m2 (0.91 [0.82–1.00]). In NHW, the positive association was strongest among those with BMI ≥30 kg/m2 (1.07 [1.02–1.12]).

CONCLUSIONS

In the U.S., a higher T2D genetic risk was associated with increased mortality risk, especially among obese NHW. The underlying genetic basis for mortality likely involves complex interactions with factors related to ethnicity, T2D, and body weight.
Use of endoscopic-assisted argon plasma coagulation for the treatment of colonic vascular ectasia (angiodysplasia) in an adult dog
Authors: Harris Autumn N. , Armentano Robert A. , Torres Ahmira R. , Gallagher Alexander E.
Published: February 2016

CASE DESCRIPTION A 10-year-old neutered male mixed-breed dog was evaluated for a 5-year history of intermittent hematochezia and chronic anemia that were unresponsive to medical treatment.

CLINICAL FINDINGS Colonoscopy revealed multifocal areas of coalescing tortuous mucosal blood vessels throughout the colon and rectum. Colonic vascular ectasia (angiodysplasia) was diagnosed on the basis of the endoscopic appearance of the lesions.

TREATMENT AND OUTCOME The dog failed to respond to traditional medical treatments for colonic vascular ectasia and required multiple plasma and blood transfusions. The dog received 4 endoscopic-assisted argon plasma coagulation treatments, which resulted in long-term resolution of gastrointestinal hemorrhage. Colonic perforation occurred during the third argon plasma coagulation treatment. The perforation was surgically repaired. The dog remained free from clinical signs of colonic vascular ectasia for > 1 year after the third argon plasma coagulation treatment and was euthanized because of clinical deterioration associated with progressive heart disease.

CLINICAL RELEVANCE Endoscopic-assisted argon plasma coagulation treatment is a novel treatment for dogs with colonic vascular ectasia and provided long-term resolution of clinical signs for the dog of this report. In human patients, complications associated with endoscopic-assisted argon plasma coagulation treatment include colonic perforation, which also occurred in the dog of this report.
Optimierte Eigenschaften von Werkzeugstahl für Presshärtewerkzeuge*
Authors: Wilzer J. J. , Escher Ch. , Kotzian M. , Weber S. , Theisen W.
Published: February 2016

Kurzfassung

Das Presshärten von hochfesten Karosseriebauteilen stellt eine Schlüsseltechnologie dar, mit der moderne Leichtbaukonzepte und hohe Sicherheitsstandards in der Automobilindustrie realisiert werden können. Die Fertigung derartiger Bauteile erfordert jedoch einen hohen technischen Standard bzgl. der Prozessführung, der Wärmeführung und der Auslegung der Presshärtewerkzeuge. Die Warmumformung der heißen Bleche verursacht dabei sowohl mechanische als auch thermische Beanspruchungen an den Werkzeugen und führt aufgrund der Relativbewegung zwischen Werkzeug und Bauteil zu Verschleiß an der Werkzeugoberfläche. Aktuelle Forschungsvorhaben haben daher zum Ziel, neue Werkzeugstähle zu entwickeln, welche in Bezug auf Presshärtewerkzeuge optimierte Eigenschaften besitzen. Eine dieser Entwicklungen ist der neue Sonderwerkstoff CP2M®, ein Werkzeugstahl mit erhöhter Wärmeleitfähigkeit und sehr gutem Verschleißwiderstand.
FE-Simulation des induktiven Härtens am Beispiel einer Kalanderwalze*
Authors: Neumeyer J. , Groth C. , Wibbeler J. , Hanke M.
Published: February 2016

Kurzfassung

Aufgrund der sauberen, reproduzierbaren Prozessführung, der hohen übertragbaren Leistungsdichte und der guten Kontrollierbarkeit der Wärmezone hat die induktive Erwärmung einen festen Platz bei der Wärmebehandlung von hochbelasteten Stahlbauteilen. Bei der Prozessführung kommt es darauf an, Erwärmzonen, Einwärmtiefen und Spitzentemperaturen sowie das zugehörige Temperatur-Zeit-Regime präzise zu steuern. Dieser Beitrag zeigt, wie das räumliche und zeitliche Temperaturprofil eines Härtungsprozesses mithilfe der Finite-Elemente-Simulation im Fall der Oberflächenhärtung einer Kalanderwalze vorausberechnet werden kann. Die Methode gestattet es, die optimale Auslegung des Induktionsprozesses wirtschaftlich und exakt vorherzubestimmen. Durch den Härteprozess werden mechanische Spannungen in der Kalanderwalze erzeugt, die die Belastungsspannungen neutralisieren und damit die Lebensdauer der Walze erhöhen.
Carbonitrieren von Einsatz- und Vergütungsstählen für Lageranwendungen
Authors: Rösch S. , Trojahn W. , Clausen B.
Published: February 2016

Kurzfassung

Für eine möglichst hohe Leistungsfähigkeit großer, einsatzgehärteter Wälzlager unter schwierigen Betriebsbedingungen, die Mangelschmierung und/oder Partikelüberrollung beinhalten, sind die Eigenschaften in der beanspruchten Randschicht der Wälzpartner entscheidend. Diese hängen wesentlich von der chemischen Zusammensetzung des Grundstahls und der Menge und Verteilung der eingebrachten Elemente Kohlenstoff bzw. Kohlenstoff und Stickstoff (Carbonitrieren) ab. Zur vergleichenden Untersuchung der Carbonitrierbarkeit wurden 11 Einsatz- und Vergütungsstähle mit unterschiedlichen Gaszusammensetzungen auf annähernd gleiche Einhärtetiefe carbonitriert. Die Randschichten wurden charakterisiert und ausgewählte Zustände wurden hinsichtlich der thermischen und mechanischen Stabilität überprüft. Ab- schließend erfolgte die Eignungsprüfung für Wälzlager anhand von Überrollungsprüfungen an Scheiben und Schrägkugellagern bei unterschiedlichen Überrollbedingungen. Das beste Gesamtergebnis unter Einbeziehung der Herstellungskosten erzielte der lufterschmolzene Stahl 32MnCrMo6–4–3 im carbonitrierten Zustand.
Empirical Longitudinal Driving Behavior in Authority Transitions between Adaptive Cruise Control and Manual Driving
Authors: Varotto Silvia F. , Hoogendoorn Raymond G. , van Arem Bart , Hoogendoorn Serge P.
Published: February 2016

Automated vehicles are expected to have a substantial impact on traffic flow efficiency, safety levels, and levels of emissions. However, field operational tests suggest that drivers may prefer to disengage adaptive cruise control (ACC) and resume manual control in dense traffic conditions and for maneuvers such as changing lanes. These so-called authority transitions can have substantial effects on traffic flow. To gain insight into these effects, a better understanding is needed of the relationships between these transitions, longitudinal dynamics of vehicles, and behavioral adaptations of drivers. In this context, a driving simulator experiment was set up to gain insight into the effects of authority transitions between ACC and manual driving on longitudinal dynamics of vehicles. Participants were assigned randomly to one of three conditions. In the control condition, participants drove manually. In the first experimental condition, a sensor failure was simulated at a specific location where drivers were expected to resume manual control. In the second experimental condition, drivers switched ACC off and on by pressing a button whenever they desired. Statistical tests indicated that the distributions of speed, acceleration, and time headway differed significantly between the three conditions. In the first experimental condition, the speed dropped after the sensor failure, and the time headway increased after the discretionary reactivation of ACC. These results seem to be consistent with previous findings and suggest that authority transitions between ACC and manual driving may significantly influence the longitudinal dynamics of vehicles and potentially mitigate the expected benefits of ACC on traffic flow efficiency.
Safe Integration of Fully Automated Road Transport Systems in Urban Environments
Authors: Csepinszky Andras , Giustiniani Gabriele , Holguin Carlos , Parent Michel , Flament Maxime , Alessandrini Adriano
Published: February 2016

Automated road transport systems (ARTS) are based on the use of fully automated road vehicles controlled by a centralized system for fleet and infrastructure management. ARTS are aimed (at least at the beginning) at supplementing mass transit in the last mile and are commercially available today. However, their deployment is limited at the moment to protected or special roads. In urban areas, where these systems can be most beneficial, they cannot be implemented because of the absence of an adapted legal framework. The CityMobil2 project, financed by the European Commission, aims to remove the legal barriers that prevent the deployment of ARTS in urban areas by developing a specific legal framework. Previous experience based on risk assessment and failure mode, effects, and criticality analysis has demonstrated acceptability to national authorities. On this basis, the CityMobil2 project has started developing a methodology for the certification of full ARTS, aimed at guaranteeing an adequate level of safety. The certification framework has been developed at the theoretical level, but during the next phases of the CityMobil2 project, it will be tested in real-world conditions during the ARTS demonstrations that will be organized in several cities of Europe to make this methodology a major reference for a future legal framework.
Methodology to Gather Multimodal Urban Trip Generation Data
Authors: Dock Stephanie , Cohen Liza , Rogers Jonathan D. , Henson Jamie , Weinberger Rachel , Schrieber Jason , Ricks Karina
Published: February 2016

Assessments of the impact of new land use development on the transportation network often rely on the ITE Trip Generation Manual informational report. Current ITE rates generally represent travel behavior for separated, single-use developments in low-density suburban areas. However, a more compact urban form, access to transit, and a greater mix of uses are known to generate fewer and shorter vehicle trips—and quite possibly more trips overall, especially in heavily urbanized areas like Washington, D.C. Local and national interest exists for generating data that expand upon existing trip rates (and similar parking generation rates) to include sites in diverse, dense contexts. The lack of adequate data on multimodal urban trip generation led the District Department of Transportation in Washington, D.C., to develop and test a streamlined methodology that meets the needs of practitioners who are evaluating the transportation impacts of new developments in dense, multimodal environments. This methodology focuses on capturing all trips to and from a site and the mode of all travelers, not just personal vehicle trips. The methodology was tested at mixed-use multifamily residential buildings but is intended for future use at a wide range of sites. This paper presents the methodology and rationale for a robust national data collection effort.
Short- and Long-Term Effects of Land Use on Reducing Personal Vehicle Miles of Travel
Authors: Zhang Wenjia , Zhang Ming
Published: February 2016

While voluminous empirical studies have examined the impact of land use on travel behavior, few have relied on longitudinal data and an analytical approach. With data from two activity travel surveys (1997 and 2006) conducted in Austin, Texas, this paper develops a longitudinal multilevel model for estimating the change in the effect of land use on vehicle miles of travel (VMT) over time and the long-range land use effect on VMT reduction. Results suggest that the influences of land use mixture and street density on VMT would vary between 2 years. The effects of VMT reduction on land use policies by raising population and street densities are salient in the short run but insignificant in the long run, whereas those of mixed-use policies are even larger in the long run. These findings validate the importance of longitudinal data and analysis in land use–travel studies and suggest that the short-run elasticity of land use derived from cross-sectional analyses may be inappropriate for assessing the long-run effect of land use–based mobility strategies for reducing VMT.
Institutional Labyrinth
Authors: Agarwal Om Prakash , Kumar Ajay
Published: February 2016

The regulation and the management of urban transport services are often fragmented across multiple institutions. The need for a lead institution to take comprehensive responsibility for urban transport is well recognized. However, attempts in some developing countries to establish effective institutions have not proved successful. This paper seeks to highlight the causes of this lack of success in two cities—Metropolitan Manila, Philippines, and Dakar, Senegal—across two continents. The paper argues that several challenges, even beyond establishing the institutions themselves, need to be addressed if these institutions are to prove effective. Inadequate definition of their role and overlap of responsibilities with other agencies, coupled with inadequate power over financial resources, can render them ineffective.
Method for the Use of Naturalistic Driving Study Data to Analyze Rear-End Crash Sequences
Authors: Wu Kun-Feng , Thor Craig P.
Published: February 2016

Many factors are associated with crash risk, but their contribution to the progression of a crash is often unclear. Research on and understanding of the crash sequence are needed. One of the advantages of studying crash sequence is to identify the causative chain of crashes and, subsequently, the identification of effective countermeasures that may feasibly mitigate crash risk. An analogy to epidemiological studies is particularly useful: although researchers confirm that many factors are associated with an increase in the probability of myocardial infarction, there is still a need to research the disease process, the physiological process that promotes disease growth, and the possible interventions to treat or even prevent the disease. This study used data from the Integrated Vehicle-Based Safety System program. Two freeway rear-end events, including one crash and one near crash, with similar crash sequences were studied. The crash sequences of the two events were as follows: ( a) the drivers maintained a temporal headway of less than 1 s at the beginning; ( b) the traffic flow conditions were likely to cause misjudgments by the drivers and result in glances in inappropriate directions; ( c) when the drivers were distracted, the leading vehicle decelerated; ( d) the drivers did not decelerate accordingly and had their feet on the accelerator pedal; and ( e) one event resulted in a crash and the other in a near crash. This study highlighted an approach for comparing and dissecting the differences in the crash sequence that led to the different outcomes.
Effects of Demographic and Driver Factors on Single-Vehicle and Multivehicle Fatal Crashes
Authors: Kumfer Wesley , Wei Dali , Liu Hongchao
Published: February 2016

Human error is often considered the leading cause of motor vehicle crashes. Although some research has been conducted to assess the influence of human factors, full driver impacts on crashes are rarely analyzed, especially on a large scale in the United States. This study sought to identify the driver behavior and demographic factors that affected the likelihood of a multivehicle or single-vehicle fatal crash. A multinomial logistic regression framework, including odds ratios, was used to analyze the variables from several states. A tiered model approach was adopted to find the variable effects for combined, urban, rural, undivided urban, divided urban, undivided rural, and divided rural data sets. Each model produced different significant demographic or driver variables, many being unique or contradictory to the expected results of other research. Gender, often seen as a major contribution to crash outcome, was significant only for the full and urban models and likely not an important variable for determining crash outcomes in rural areas. Distracted driving and failing to make avoidance maneuvers were notably significant across various roadway types. Contrary to other studies, age, licensure, restraint use, and driving at certain times of the day were not found to be significant factors for either single- or multivehicle fatal crashes. Last, some previous conclusions about the number of occupants were refuted. These results may help safety analysts improve crash analysis and prevention methods.
Impact of Repeated Exposure to a Multilevel Working Memory Task on Physiological Arousal and Driving Performance
Authors: Belyusar Daniel , Mehler Bruce , Solovey Erin , Reimer Bryan
Published: February 2016

Drivers are increasingly confronted with a multitude of simultaneous secondary tasks. Consequently, the ability to manage this elevated workload is a rising concern. A growing body of evidence has suggested that changes in physiology, such as heart rate (HR) and skin conductance level (SCL), along with driving metrics, such as velocity and steering wheel reversal rates, could allow a real-time monitoring of this workload. However, laboratory research often does not evaluate drivers' experience of secondary tasks over multiple repetitions or time. The present study examined the sensitivity of a variety of performance and physiological measures to changes in workload and assessed the impact of repeated exposure to a set of n-back calibration tasks. When averaged across repeated exposures, the results closely followed previous literature: increased working memory load from the n-back tasks resulted in significant increases in HR and SCL. Although each repetition of the task showed similar changes as workload increased (for example, increased HR during more difficult tasks), this effect was consistently higher for the initial compared with second and third exposures to each level of the task. Furthermore, some measures (HR, SCL) were more reliable over time than were others (steering wheel reversals, velocity). These findings may be related in part to the emotional arousal of being asked to do a task for the first time. The implications are discussed.
Test–Retest Reliability of the Susceptibility to Driver Distraction Questionnaire
Authors: Marulanda Susana , Chen Huei-Yen Winnie , Donmez Birsen
Published: February 2016

The Susceptibility to Driver Distraction Questionnaire (SDDQ) investigates voluntary and involuntary factors associated with driver distraction. The questionnaire consists of 39 items in six subscales: (a) self-reported distraction engagement, (b) attitudes toward distractions, (c) perceived control of driving while engaged in distractions, (d) injunctive social norms associated with distraction engagement, (e) descriptive social norms associated with distraction engagement, and (f) susceptibility to involuntary distractions. A sample of 43 adults, ages 25 to 39 years, was used to assess the test–retest reliability of the SDDQ. The mean time between test and retest conditions was approximately 20 days. For sub-scale averages, intraclass correlation (ICC) statistics were used to assess test–retest reliability; weighted kappa statistics were used to assess individual items. The ICC results suggest good to excellent test–retest reliability for subscales of self-reported distraction engagement, attitudes toward distractions, and descriptive social norms. Perceived control of driving while engaged in distractions had fair test–retest reliability, and the injunctive norms and susceptibility to involuntary distraction subscales had poor test–retest reliabilities. The latter two subscales may have to be redesigned; this paper provides relevant suggestions for revision in the discussion of the results. As an additional preliminary analysis, data from a sample of 10 additional participants were used to investigate the consistency of responses across longer periods of time. The mean time between test–retest conditions in this sample was approximately 8 months. In general, the findings were similar to those in the main sample. Overall, the SDDQ appears to have good test–retest reliability. A larger sample is recommended for further validation of these results, in particular across long test–retest periods.
Effects of Guide and Logo Signs on Freeway Driving Behavior
Authors: Pankok Carl , Kaber David , Rasdorf William , Hummer Joseph
Published: February 2016

In the United States, white-on-blue highway logo signs are typically used to notify drivers of food, gas, and lodging at an upcoming interchange, whereas green guide signs are used to notify drivers of the distance to upcoming cities and roadways. This study assessed driver performance and attention allocation during simulated interstate freeway driving when drivers were exposed to six-panel logo signs, nine-panel logo signs, and green guide signs. The results revealed that glance durations and fixation frequencies to green guide signs were significantly lower than they were for six-panel and nine-panel logo signs; however, no differences were found between six-panel and nine-panel logo signs. There were statistical differences between the independent variables for speed deviation and lane deviation, but the magnitudes of difference were not considered practically significant for driving safety. Overall, minor differences in sign processing time between logo signs and green guide signs did not translate into degradations in vehicle control.