bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear ego-motion estimation from optical flow for online control of a quadrotor UAV
Authors: Grabe Volker , Bülthoff Heinrich H. , Scaramuzza Davide , Giordano Paolo Robuffo
Published: May 2015

For the control of unmanned aerial vehicles (UAVs) in GPS-denied environments, cameras have been widely exploited as the main sensory modality for addressing the UAV state estimation problem. However, the use of visual information for ego-motion estimation presents several theoretical and practical difficulties, such as data association, occlusions, and lack of direct metric information when exploiting monocular cameras. In this paper, we address these issues by considering a quadrotor UAV equipped with an onboard monocular camera and an inertial measurement unit (IMU). First, we propose a robust ego-motion estimation algorithm for recovering the UAV scaled linear velocity and angular velocity from optical flow by exploiting the so-called continuous homography constraint in the presence of planar scenes. Then, we address the problem of retrieving the (unknown) metric scale by fusing the visual information with measurements from the onboard IMU. To this end, two different estimation strategies are proposed and critically compared: a first exploiting the classical extended Kalman filter (EKF) formulation, and a second one based on a novel nonlinear estimation framework. The main advantage of the latter scheme lies in the possibility of imposing a desired transient response to the estimation error when the camera moves with a constant acceleration norm with respect to the observed plane. We indeed show that, when compared against the EKF on the same trajectory and sensory data, the nonlinear scheme yields considerably superior performance in terms of convergence rate and predictability of the estimation. The paper is then concluded by an extensive experimental validation, including an onboard closed-loop control of a real quadrotor UAV meant to demonstrate the robustness of our approach in real-world conditions.
Long-range stereo visual odometry for extended altitude flight of unmanned aerial vehicles
Authors: Warren Michael , Corke Peter , Upcroft Ben
Published: May 2015

Visual Odometry is a key technology for robust and accurate navigation of unmanned aerial vehicles in a number of low altitude applications (<120 m), particularly in environments where access to a global positioning system is possible, but not guaranteed. Navigating via vision alone reduces dependence on a global positioning system and other global navigation satellite systems, enhancing navigation robustness even in the presence of jamming, spoofing or long dropouts. To date, however, most demonstrations of visual odometry are in close proximity to the ground or other structures and are often implemented as a monocular camera combined with inertial sensing, rather than vision alone, to account for scale drift. Stereo visual odometry has received little attention for applications beyond 30 m altitude due to the generally poor performance of stereo rigs for these extremely small baseline-to-depth ratios, otherwise termed long-range stereo. This paper demonstrates stereo visual pose estimation at altitudes of up to 120 m above ground level on a small fixed-wing unmanned aerial vehicle by adapting the traditional stereo visual odometry paradigm to explicitly account for inaccurate triangulation and poorly observed scale from the stereo baseline. In addition, issues related to long-range stereo such as biased sensing are investigated to justify the approach, and a novel bundle adjustment algorithm is presented capable of handling vibration induced structural deformation between the cameras. This is achieved by continually optimizing the stereo transform within a set of inequality bounds. Results are presented demonstrating the algorithm on field-gathered data from a 2 m wingspan fixed-wing unmanned aerial vehicle flying at 30-120 m altitude over a 6.5 km trajectory.
What contextual factors shape ‘innovation in innovation’? Integration of insights from the Triple Helix and the institutional logics perspective
Authors: Cai Yuzhuo
Published: May 2015

While the Triple Helix relationship between university, industry and government, called ‘innovation in innovation’ by Etzkowitz, has frequently been a key concept guiding national and regional innovation policies around the world, there is an emerging awareness that no one-size-fits-all approach can be used in developing innovation systems. Criticism has been expressed that the conceptualization of the Triple Helix model in the most recent literature pays little attention to contextual effects. The present article seeks to enhance the context sensitivity of the Triple Helix model by integrating it with the insights of institutional logics. More specifically, seven ‘ideal’ institutional logics aligned with ‘ideal’ Triple Helix activities in Western society are identified. These have a potential to be used as a conceptual/benchmarking framework for understanding how institutional settings, particularly institutional logics, influence the development of Triple Helix innovation systems in different national contexts. To verify such a proposition, some alternative Triple Helix models as well as associated institutional logics are compared to the ideal-type, demonstrating that different institutional logics may divert the Triple Helix interactions in other directions. Meanwhile, it is claimed that institutional logics do not necessarily lead to a Triple Helix model but serve only as enabling conditions. To what extent the Triple Helix will be developed depends on innovation policies and on the key actors involved in the innovation process. The framework constructed in this study aims to provide a solid basis from which policymakers, especially those from developing and transition countries, may improve the design of these innovation policies by employing appropriate Triple Helix approaches.
Development of construction materials using nano-silica and aggregates recycled from construction and demolition waste
Authors: Mukharjee Bibhuti Bhusan , Barai Sudhirkumar V
Published: May 2015

The present work addresses the development of novel construction materials utilising commercial grade nano-silica and recycled aggregates retrieved from construction and demolition waste. For this, experimental work has been carried out to examine the influence of nano-silica and recycled aggregates on compressive strength, modulus of elasticity, water absorption, density and volume of voids of concrete. Fully natural and recycled aggregate concrete mixes are designed by replacing cement with three levels (0.75%, 1.5% and 3%) of nano-silica. The results of the present investigation depict that improvement in early days compressive strength is achieved with the incorporation of nano-silica in addition to the restoration of reduction in compressive strength of recycled aggregate concrete mixes caused owing to the replacement of natural aggregates by recycled aggregates. Moreover, the increase in water absorption and volume of voids with a reduction of bulk density was detected with the incorporation of recycled aggregates in place of natural aggregates. However, enhancement in density and reduction in water absorption and volume of voids of recycled aggregate concrete resulted from the addition of nano-silica. In addition, the results of the study reveal that nano-silica has no significant effect on elastic modulus of concrete.
Experimental and numerical study on attenuation of thermal radiation from large-scale pool fires by water mist curtain
Authors: Zhu Pei , Wang Xishi , Wang Zhigang , Cong Haiyong , Ni Xiaomin
Published: May 2015

Full-scale experiments and numerical simulations were conducted to study the thermal radiation attenuation from large fires by water mist curtain with low and intermediate pressures. Fire dynamics simulator (version 6) was used for numerical simulations. A novel multi-injector nozzle was designed to generate a homogeneous water mist curtain with low water consumption. Water mist characteristics of one of the injectors were measured by Shadowgraphy technology. A 1 × 1 m diesel pool fire was considered as the fire source. The experimental results show that the water mist curtain has high thermal radiation attenuation efficiency, for example, about 82.7% radiant heat flux could be attenuated by the water mist curtain with 2 MPa working pressure and flow rate of 13.3 L/min. Comparisons with the experimental results show that the calculated radiant heat flux and temperature are slightly underestimated.
Mexican American Adolescent Couples Communicating About Conflict
Authors: Rueda Heidi Adams , Williams Lela Rankin
Published: May 2015

Using observational methods on a small sample of committed Mexican American couples ( N=10, ages 15-17, M length of relationship = 26.5 months), we describe and categorize developmental and cultural communication patterns concerning the negotiation of conflict issues. Videotaped dyadic interactions were transcribed and qualitatively coded using iterative confirmatory and exploratory approaches. Quantitative indicators confirmed the categorization of couples into discourse styles, as well as elucidated the contexts and extent of overlap of developmental and cultural themes. Nine of ten couples had a serious discussion of relational conflict issues, lasting a majority of the time allotted (14 minutes). Five couples’ conversations were consumed by blaming/criticizing, interrupted by small stretches of one-sided taking of responsibility, suggestions, or voiced intentions for new behaviors to resolve the conflict. The remaining four couples enhanced their understanding of the relationship through mutual and respectful exploration of their chosen conflict issues. Culturally salient themes were identified, including adaptive machismo, familismo, and caballero care. The latter denoted bids for demonstration of care or affection from a girl on behalf of her partner, which together with discussion of family-oriented topics, contextualized the content of conflict discussions. Adolescent boys demonstrated adaptive machismo traits, elucidating how conflict negotiation itself was influenced by cultural values. Taken together, findings point to the importance of viewing Mexican American adolescents’ negotiation of conflict in light of cultural values including commitment to the relationship.
Another Version of the Wreck of the Neva
Authors: Bland Richard L.
Published: May 2015

As 1813 dawned, Alexander Andreevich Baranov had been chief director of the Russian-American Company (RAC) since its inception in 1799. Having been in Russian America for 23 years, he had wanted to go home to Russia for some time and had petitioned the RAC board of directors several times to replace him. In 1810, the Board of Directors had sent Collegiate Assessor Ivan Gavrilovich Kokh (Johann Koch) to replace Baranov. However, while the ship was over-wintering in Kamchatka on its way to Novo-Arkhangel’sk, Kokh unexpectedly died. A second replacement was soon found in Collegiate Councilor Terentii Stepanovich Bornovolokov, who made his way to Kamchatka, then set off from there to Novo-Arkhangel’sk (present-day Sitka) on the ship Neva in the summer of 1812. On 9 January 1813, virtually within sight of Novo-Arkhangel’sk, the Neva was wrecked. In 1849, Alexander Ivanovich Markov published an account of the shipwreck, which has been translated and annotated to form the subject of this research note.
Southampton’s sixteenth-century illicit trade: An examination of the 1565 Port Survey
Authors: Parker Leanna T
Published: May 2015

The sixteenth-century English smuggling trade has, in recent years, become a topic of increasing interest to historians of trade and maritime culture. Investigation into the inner workings of England’s ports and their relations with the wider world has helped to create a fuller image of sixteenth-century culture and politics. This research note examines the unpublished and understudied ‘Survey of the Port of Southampton’, commissioned by Elizabeth I in 1565 in an effort to deter illicit trading in English ports. Through study of this underused resource, this research note is designed to enhance understanding of smuggling culture in the sixteenth century, and to demonstrate the effect that regional, national and international factors could have on the types of illicit trade undertaken by smugglers.
Professional Seamen: A Strategic Resource during the Scanian War, 1675–1679
Authors: Nørlund Christensen Asger
Published: May 2015

On 1 July 1677, the Danish navy won a decisive victory over a superior Swedish fleet in the bight of Koge. This success was partly due to trained seamen, who had been recruited in Amsterdam and manned the Danish men-of-war. Another professional seaman was the admiral Cornelis Tromp, who had been employed by the Danish king, not only for his skill and talent as a naval commander, but also because his very presence in Baltic waters had a deterrent effect on the Swedes. This article assesses these experienced seamen and argues that they were skilled craftsmen, who were just as important a resource for the success of a navy as big ships and heavy guns. So important, in fact, that the naval authorities were willing to pay relatively high wages to secure the expertise of professional seamen.
Trade unions and labour market dualisation: a comparison of policies and attitudes towards agency and migrant workers in Germany and Belgium
Authors: Pulignano Valeria , Meardi Guglielmo , Doerflinger Nadja
Published: May 2015

This article addresses the questions of the extent to which, and the reasons why, western European trade unions may have privileged the protection of ‘insiders’ over that of ‘outsiders’. Temporary agency workers, among whom migrant workers are over-represented, are taken as a test case of ‘outsiders’. The findings from a comparison of Belgian and German multinational plants show that collective agreements have allowed a protection gap between permanent and agency workers to emerge in Germany, but not in Belgium. However, the weaker protection in Germany depends less on an explicit union choice for insiders than on the weakening of the institutional environment for union representation and collective bargaining. The conclusion suggests that European unions are increasingly trying to defend the outsiders, but meet institutional obstacles that vary by country.
Necromechanics: Death-induced changes in the mechanical properties of human tissues
Authors: Martins Pedro ALS , Ferreira Francisca , Natal Jorge Renato , Parente Marco , Santos Agostinho
Published: May 2015

After the death phenomenon, the rigor mortis development, characterized by body stiffening, is one of the most evident changes that occur in the body. In this work, the development of rigor mortis was assessed using a skinfold caliper in human cadavers and in live people to measure the deformation in the biceps brachii muscle in response to the force applied by the device. Additionally, to simulate the measurements with the finite element method, a two-dimensional model of an arm section was used. As a result of the experimental procedure, a decrease in deformation with increasing postmortem time was observed, which corresponds to an increase in rigidity. As expected, the deformations for the live subjects were higher. The finite element method analysis showed a correlation between the c1 parameter of the neo-Hookean model in the 4- to 8-h postmortem interval. This was accomplished by adjusting the c1 material parameter in order to simulate the measured experimental displacement. Despite being a preliminary study, the obtained results show that combining the proposed experimental procedure with a numerical technique can be very useful in the study of the postmortem mechanical modifications of human tissues. Moreover, the use of data from living subjects allows us to estimate the time of death paving the way to establish this process as an alternative to the existing techniques. This solution constitutes a portable, non-invasive method of estimating the postmortem interval with direct quantitative measurements using a skinfold caliper. The tools and methods described can be used to investigate the subject and to gain epidemiologic knowledge on rigor mortis phenomenon.
A new alternative to expandable pedicle screws: Expandable poly-ether-ether-ketone shell
Authors: Demir Teyfik
Published: May 2015

Screw pullout is a very common problem in the fixation of sacrum with pedicle screws. The principal cause of this problem is that the cyclic micro motions in the fixation of sacrum are higher than the other regions of the vertebrae that limit the osteo-integration between bone and screw. In addition to that, the bone quality is very poor at sacrum region. This study investigated a possible solution to the pullout problem without the expandable screws’ handicaps. Newly designed poly-ether-ether-ketone expandable shell and classical pedicle screws were biomechanically compared. Torsion test, pullout tests, fatigue tests, flexion/extension moment test, axial gripping capacity tests and torsional gripping capacity tests were conducted in accordance with ASTM F543, F1798 and F1717. Standard polyurethane foam and calf vertebrae were used as embedding medium for pullout tests. Classical pedicle screw pullout load on polyurethane foam was 564.8 N compared to the failure load for calf vertebrae’s 1264 N. Under the same test conditions, expandable poly-ether-ether-ketone shell system’s pullout loads from polyurethane foam and calf vertebrae were 1196.3 and 1890 N, respectively. The pullout values for expandable poly-ether-ether-ketone shell were 33% and 53% higher than classical pedicle screw on polyurethane foam and calf vertebrae, respectively. The expandable poly-ether-ether-ketone shell exhibited endurance on its 90% of yield load. Contrary to poly-ether-ether-ketone shell, classical pedicle screw exhibited endurance on 70% of its yield load. Expandable poly-ether-ether-ketone shell exhibited much higher pullout performance than classical pedicle screw. Fatigue performance of expandable poly-ether-ether-ketone shell is also higher than classical pedicle screw due to damping the micro motion capacity of the poly-ether-ether-ketone. Expandable poly-ether-ether-ketone shell is a safe alternative to all other expandable pedicle screw systems on mechanical perspective.
Competitive sports participation in high school and subsequent substance use in young adulthood: Assessing differences based on level of contact
Authors: Veliz Philip , Schulenberg John , Patrick Megan , Kloska Deborah , McCabe Sean Esteban , Zarrett Nicole
Published: May 2015

The objective of this study is to examine how participation in different types of competitive sports (based on level of contact) during high school is associated with substance use 1 to 4 years after the 12th grade. The analysis uses nationally representative samples of 12th graders from the Monitoring the Future Study, who were followed 1 to 4 years after the 12th grade. The longitudinal sample consisted of 970 12th graders from six recent cohorts (2006–2011). The analyses, which controlled for 12th grade substance use, school difficulties, time with friends, and socio-demographic characteristics, found that respondents who participated in at least one competitive sport during the 12th grade had greater odds of binge drinking during the past two weeks (AOR = 2.04; 95% CI = 1.43, 2.90) 1 to 4 years after the 12th grade, when compared to their peers who did not participate in sports during their 12th grade year. Moreover, respondents who participated in high-contact sports (i.e. football, ice hockey, lacrosse, and wrestling) had greater odds of binge drinking (AOR = 1.80; 95% CI = 1.18, 2.72), and engaging in marijuana use during the past 30 days (AOR = 1.81; 95% CI = 1.12, 2.93) 1 to 4 years after the 12th grade when compared to their peers who did not participate in these types of sports during their 12th grade year. Accordingly, the findings indicate important distinctions in sport participation experiences on long-term substance use risk that can help inform potential interventions among young athletes.
What Was (Also) at Stake When a Robot Bathtub Was Implemented in a Danish Elder Center
Authors: Beedholm Kirsten , Frederiksen Kirsten , Lomborg Kirsten
Published: May 2015

Assistive technologies are often considered to be passive tools implemented in targeted processes. Our previous study of the implementation of the robot bathtub in a Danish elder center suggested that purposeful rationality was not the only issue at stake. To further explore this, we conducted a constructivist secondary qualitative analysis. Data included interviews, participant observations, working documents, and media coverage. The analysis was carried out in two phases and revealed that the bathing of the older people was constructed as a problem that could be offensive to the users’ integrity, damaging to their well-being, and physically strenuous for the staff. The older users and the nursing staff were constructed as problem carriers. We conclude that technological solutions are not merely neutral and beneficial solutions to existing problems, but are rather part of strategic games contributing to the construction of the very problems they seek to solve.
An Ethnographic-Discursive Approach to Parental Self-Help Groups
Authors: Frigerio Alessandra , Montali Lorenzo
Published: May 2015

Mutual aid groups have become a common form of help in the mental health field. Although self-help groups are associated with a range of health and social benefits, they remain poorly understood in terms of the dynamics of their interactions. Adopting an ethnographic-discursive approach, we conducted a 6-month observation of the meetings of a self-help group of parents with children diagnosed with attention deficit/hyperactivity disorder (ADHD) to analyze the discursive dynamics of the interactions that characterized the group. Using a set of discursive strategies and practices, the parents promoted a homogeneity of viewpoints and experiences within the group and constructed a shared and consensual narrative to endorse a specific understanding of ADHD. The production of both homogeneity within the group and a shared narrative served to absolve parents of guilt, helped parents to signify their experience within a blaming social context, and preserved their identities as “good parents.”
Evaluation of the Patterns of Care Provided to Patients With COPD Compared to Patients With Lung Cancer Who Died in Hospital
Authors: Hyasat Kais , Sriram Krishna B.
Published: May 2015

Introduction:

There is limited information about the end-of-life care provided to patients with end-stage chronic obstructive pulmonary disease (COPD) in comparison to patients with lung cancer.

Aim and Methods:

We compared the end-of-life care provided to patients with COPD versus patients with lung cancer who died in hospital over a 12-month period in our institution.

Results:

During the study period, 89 patients died due to COPD (n = 34) or lung cancer (n = 55). Compared to patients with lung cancer, patients with COPD received less palliative care services (50% vs 9%, P < .001) and underwent more diagnostic tests and received more life-prolonging measures.

Conclusion:

Toward the end of their life, patients with COPD received fewer symptom-alleviating treatments and palliative care services.
Blood Glucose Response to Rescue Dextrose in Hypoglycemic, Critically Ill Patients Receiving an Insulin Infusion
Authors: Murthy Manasa S. , Duby Jeremiah J. , Parker Patricia L. , Durbin-Johnson Blythe P. , Roach Denise M. , Louie Erin L.
Published: May 2015

Background: There is inadequate guidance for clinicians on selection of the optimal dextrose 50% (D50W) dose for hypoglycemia correction in critically ill patients. Objective: The purpose of this study was to determine the blood glucose (BG) response to D50W in critically ill patients. Methods: A retrospective analysis was conducted of critically ill patients who received D50W for hypoglycemia (BG < 70 mg/dL) while on an insulin infusion. The primary objective of this study was to determine the BG response to D50W. The relationship between participant characteristics and the dose-adjusted change in BG following D50W was analyzed using simple and multiple linear mixed-effects models. Results: There were 470 hypoglycemic events (BG < 70 mg/dL) corrected with D50W. The overall median BG response was 4.0 (2.53, 6.08) mg/dL per gram of D50W administered. Administration of D50W per protocol resulted in 32 episodes of hyperglycemia (BG > 150 mg/dL), resulting in a 6.8% rate of overcorrection; 49% of hypoglycemic episodes (230/470) corrected to a BG >100 mg/dL. A multivariable GEE analysis showed a significantly higher BG response in participants with diabetes (0.002) but a lower response in those with recurrent hypoglycemia ( P = 0.049). The response to D50W increased with increasinginsulin infusion rate ( P = 0.022). Burn patients experienced a significantly larger BG response compared with cardiac, medical, neurosurgical, or surgical patients. Conclusions: The observed median effect of D50W on BG was approximately 4 mg/dL per gram of D50W administered. Application of these data may aid in rescue protocol development that may reduce glucose variability associated with hypoglycemic episodes and the correction.
Performance of a Divided-Load Intravenous Vancomycin Dosing Strategy for Obese Patients
Authors: Denetclaw Tina Harrach , Yu Mark Kevin , Moua Mee , Dowling Thomas C. , Steinke Douglas
Published: May 2015

Background: Current guidelines recommend vancomycin trough concentrations of 15 to 20 µg/mL in complicated infections and all trough concentrations >10 µg/mL to avoid developing microbial resistance. To date, no published protocol reliably meets these recommendations for obese patients. Objective: We assessed the performance of a novel, obese-specific, divided-load vancomycin protocol for attaining target trough concentrations within 12 to 24 hours of dosing initiation, and during maintenance dosing, in obese patients. Methods: The protocol was evaluated through prospective medical record review in 54 consecutive obese patients. Vancomycin serum concentrations were drawn before the third and fifth dose after initiation. Steady-state concentrations were drawn after the third dose once maintenance dosing was achieved and periodically thereafter. Results: Within 12 hours after dosing initiation, 48 (89%) study patients exhibited trough concentrations of 10 to 20 µg/mL averaging 14.5 ± 3.2 µg/mL; 51 (94%) study patients exhibited trough concentrations >10 µg/mL within 12 hours after dosing initiation, and 3 (6%) had trough concentrations >20 µg/mL. Thirty-one participants had second trough concentrations drawn within 24 hours of dosing initiation, averaging 15.0 ± 3.1 µg/mL; 24 patients had a total of 32 trough concentrations drawn during maintenance dosing, averaging 15.1 ± 2.5 µg/mL. Conclusion: Obese-specific, divided-load dosing achieved trough concentrations of 10 to 20 µg/mL for 89% of obese patients within 12 hours of initial dosing and 97% of obese patients within 24 hours of initial dosing while preventing doses given during supratherapeutic trough levels; 97% of troughs measured during steady state were within target range.
Meet the Press or Meet the Men? Examining Women’s Presence in American News Media
Authors: Baitinger Gail
Published: May 2015

Why are women still a minority presence in American news media? Some accounts attribute the dearth of women as political newsmakers to sexism, but journalistic norms to attain the best source for a story suggest that sex should be irrelevant. To date, however, no study has systematically tested these competing hypotheses. Based on a new, original data set of more than 4,200 appearances by elected officials and non-elected political actors on the Sunday morning talk shows, I find that female elected officials, journalists, and political activists appear as guests less frequently than men do. But the gender gap does not result from overt sexism. Rather, the characteristics that contribute to repeated appearances on Sunday morning are consistent with journalistic norms to provide balance and credibility in reporting. Because there are few women in the positions and professions from which guests are selected, though, these norms also perpetuate a gendered news environment.
Neuroendocrine Neoplasms of the Major Duodenal Papilla With Focus on Histopathological Features and Prognosis
Authors: Zhang Qin , Lu Cheng-Jun , Zhang Xiang , Ma Zhe , Xin Qi , Zhang Chuan-Shan
Published: May 2015

Neuroendocrine neoplasms (NENs) are generally indolent and progress slowly. However, NENs of major duodenal papilla are uncommon. We retrospectively assessed relevant clinicopathological findings in 9 consecutive patients treated for major duodenal papilla NENs by pancreaticoduodenectomy in our hospital from 2009 to 2013. Eight of the 9 patients (89%) presented with painless obstructive jaundice and one with intermittent fever, attributable to pancreatitis, without jaundice. The diagnostic accuracy was 75% (6/8) for biopsies obtained under duodenoscope guidance. Enhanced multidetector computed tomography detected 89% (8/9) of tumors. Patients with uncertain preoperative diagnoses all underwent intraoperative frozen section pathological diagnosis. Tumor cells extended to at least the muscularis propria in all patients. There were 5 neuroendocrine tumors, 2 neuroendocrine carcinomas, and 2 mixed adenoneuroendocrine carcinomas. Two, 4, and 3 cases were grades 1, 2, and 3, respectively. Grade 3 tumor patients had poor prognoses with tumor recurrence or metastasis within 2 months and all died within 1year. The overall survival rate (1 year) of grade 3 was lower than in grades 1 and 2 ( P < .05). Patients with grade 1 tumors had a similar prognosis to grade 2 ( P > .05). To date, only 4 cases of this tumor have been reported in the Chinese literature. The prognosis can be predicted accurately by histopathological features accordingly to the World Health Organization 2010 classification. Multiple imaging techniques and pathological examination should be carried out appropriately to diagnose the disease early.
Vibration characteristic analysis and numerical confirmation of an axially moving plate with viscous damping
Authors: Tang You-Qi , Zhang Deng-Bo , Gao Jia-Ming
Published: May 2015

In this paper, the vibration characteristics of axially moving plates with viscous damping are analyzed. A partial differential linear equation of motion with four simply supported edges is presented. The effects of two different viscous damping models are highlighted, while both of them have been introduced in previous studies. The investigation into the two different viscous damping models is interesting in itself. It is noteworthy that which model is closer to the fact, for which there are no systematic techniques of investigation to deal with this problem. In order to give a reference for possible verification in experiment, the difference of the two different viscous damping models in theory was proposed. The complex frequencies and its corresponding complex modes are studied by the complex mode approach. As other parameters are fixed, the effect of some parameters, such as viscous damping coefficients, axial speeds, aspect ratios, stiffness ratios, and support stiffness parameters, on the frequencies and critical speeds are examined. The complex modes illustrated in the 3-demensional figures are neither symmetric nor anti-symmetric to the midpoint of the plate owing to the plate motion. The differential quadrature scheme is used to verify the modes for the first time. The numerical calculations confirm the analytical results.
A Retrospective Review of Reconstructive Options and Outcomes of 202 Cases Large Facial Mohs Micrographic Surgical Defects, Based on the Aesthetic Unit Involved
Authors: van Leeuwen Anne C. , The Ayleen , Moolenburgh Sanne E. , de Haas Ellen R.M. , Mureau Marc A.M.
Published: May 2015

Background:

For optimal treatment of facial defects following Mohs micrographic surgery (MMS), the aesthetic unit principles should be applied. Often multiple staged procedures and revisions are necessary.

Objective:

To analyze the reconstructive options and outcomes for complex facial defects per aesthetic unit.

Methods:

Data of 202 patients, who underwent a facial reconstruction at the department of plastic and reconstructive surgery following MMS, were collected.

Results:

The central facial units were affected in more than 70%, with over 20% of the defects involving more than 1 unit. Nasal defects required the longest reconstruction time (3-staged forehead flap) and periocular defects the most revisional procedures. In more than 50%, additional operations (range, 1-5) were needed. In 12%, postoperative complications occurred.

Conclusion:

An overview for the reconstructive options of extensive facial skin cancer is presented. Proper treatment requires a structured multidisciplinary approach in order to achieve excellent tumour control and a satisfactory aesthetic and functional end result.
The Hobbit hyperreality paradox
Authors: Michelle Carolyn , Davis Charles H , Hight Craig , Hardy Ann L
Published: May 2015

The 3D high frame rate version of Peter Jackson’s first Hobbit film was touted as offering one of the most realistic and engaging movie-going experiences to date, its innovative projection technologies promising to greatly enhance viewers’ sense of immersion in the fantastical world of Middle-earth. However, our empirical research suggests the specific combination of technologies in The Hobbit had paradoxical perceptual and experiential effects. Whereas the groundbreaking hyperrealistic aesthetic enhanced both spectacular and narrative immersion for many viewers, a significant number experienced this same visual aesthetic as unconvincing and distracting and as undermining suspension of disbelief. In this article, we identify key factors contributing to polarization among Hobbit viewers on aesthetic grounds and offer empirical insights into how emerging cinematic technologies may be reshaping film spectatorship.
‘Whom will I give him to? The difficulty is mine’ : Psychosocial difficulties experienced by care givers of patients with epilepsy in Cape Town, South Africa
Authors: Keikelame Mpoe Johannah , Swartz Leslie
Published: May 2015

Epilepsy has been reported as one condition that can cause psychological difficulties and distress to care givers of patients suffering from the condition. This study explored psychological difficulties experienced by lay care givers of patients with epilepsy in an urban township in South Africa. Nine individual in-depth interviews were conducted with lay carers who provide care to their relatives, friends and neighbours who have epilepsy. A thematic data analysis method was used. Some fears, social concerns and worries affecting care giving were reported. Community interventions that promote cultural sensitivity in mental health care and empowerment of these carers are needed.
Self-efficacy mediates the relationship of depressive symptoms and social support with adherence in patients with heart failure
Authors: Tovar Elizabeth G , Dekker Rebecca L , Chung Misook L , Gokun Yevgeniya , Moser Debra K , Lennie Terry A , Rayens Mary Kay
Published: May 2015

Poor self-care is common among adults with heart failure and leads to poor health outcomes. Low self-efficacy, depression, and low social support are associated with poor self-care, but knowledge about these relationships in heart failure is limited. Secondary data analysis of cross-sectional data from 346 adults with heart failure measuring self-efficacy, depressive symptoms, social support, and self-care adherence was conducted. Tests of mediation using multiple linear regressions indicate that self-efficacy fully mediates the relationships between depression and adherence, and social support and adherence. Bolstering self-efficacy may have a greater impact on self-care adherence than targeting either depression or social support alone.
The price of love: The Big Bang Theory, the family and neoliberalism
Authors: Stratton Jon
Published: May 2015

This essay is about the hugely successful sitcom, The Big Bang Theory. The programme is centred on an ensemble cast of five main characters, the central two of whom, Sheldon Cooper and Leonard Hofstadter, share an apartment, who are highly intelligent and work at California Institute of Technology, and a woman, Penny, whose family name is never revealed, who lives across the hall from Sheldon and Leonard. In this essay, I argue that through the behaviour of the characters, the show reproduces many of the key ideological assumptions of neoliberalism. Neoliberalism is a socio-economic theory of social life which privileges competition above all affective social bonds. I argue that Sheldon’s lack of empathy, which has led many viewers to assume he has Asperger’s Syndrome, is also a key characteristic of success in the neoliberal order. I go on to explore the complexity of family relations in neoliberalism and compare these to the familial structures in The Big Bang Theory.
Intra-cycle recirculation of partial oxidation products (RePOx): A concept for internal combustion engine combustion control
Authors: Dantuluri Venkateswara Raju , Puzinauskas Paulius V , Agrawal Ajay K
Published: May 2015

This work studies the potential for using intra-cycle recirculation of partial oxidation products (RePOx) to control the combustion phasing of advanced internal combustion engine combustion systems such as HCCI. The partial oxidation products are created by extracting a portion of the lean charge products during the expansion stroke and mixing these with the fuel in an auxiliary chamber (RePOx prechamber). The equivalence ratio of the recirculated reactants is controlled by varying the amount of mass extracted. The recirculated partially oxidized products are then reintroduced into the main chamber and mixed with compressed air to facilitate the main chamber reaction. This process was modeled using the CHEMKIN-PRO software package combined with an external program to balance mass and energy for the RePOx system. n-Heptane, modeled with a detailed reaction mechanism, was used as the fuel. The effects of extraction mass, extraction timing, injection timing, prechamber volume and overall equivalence ratio were examined. Varying prechamber volume did not show any effect on the performance or combustion phasing under the conditions and assumptions of this study, whereas injection timing, extraction mass and extraction timing were found to have significant effects on combustion phasing indicating the RePOx concept could possibly be used to control HCCI and derivative internal combustion engine combustion systems. The most significant effect was achieved by varying the extraction mass, where increasing the extraction mass from 5% to 7% advanced the combustion phasing by 8° crank angle. RePOx system was also found to increase the lean limit by 0.05 equivalence ratio compared to conventional HCCI without any specific optimization for lean operation.
Numerical investigation of late injection strategy to achieve premixed charge compression ignition mode of operation
Authors: Ganesh V , Deshpande S , Sreedhara S
Published: May 2015

Premixed charge compression ignition mode of operation simultaneously reduces oxides of nitrogen (NOx) and particulate matter with improved fuel economy. Late injection is one such strategy to achieve premixed charge compression ignition mode along with the control over the ignition timing. Late injection along with charge dilution retards combustion and prepares homogeneous mixture by providing sufficient ignition delay. The in-cylinder charge distribution dictates mixture formation which affects the performance and emissions characteristics. Experimental results fail to provide an insight of the in-cylinder processes involved. Hence, numerical simulations have been performed to get in-cylinder distributions of scalars, which help in understanding the combustion process. The work consists of late in-cylinder injection of Diesel wherein the heat release rate trace shows only a premixed mode with lower soot and NOx. The absence of diffusion combustion confirms that the engine operates in a premixed charge compression ignition mode. In this work, effects of various injection parameters and swirl ratio on engine in-cylinder processes, performance and exhaust emissions have been studied using a three-dimensional model with detailed chemistry by using Converge, a computational fluid dynamics tool. Increasing swirl ratio improved air–fuel mixing causing lower soot emission up to a certain limit beyond which further increase in swirl ratio led to higher soot emission due to increased heat loss. Delayed start of injection resulted in delayed combustion leading to lower soot and NOx emission but partial oxidation resulted in higher carbon monoxide (CO) emissions. Nozzle tilt angle beyond 70° led to the formation of fuel-rich mixture at the center of combustion chamber resulting in higher soot and CO emissions. A narrow spray cone angle improved air–fuel mixing leading to lower soot but produced higher NOx. Medium swirl with late injection timing and wide nozzle tilt angle along with narrower spray cone angle resulted in lower emissions without deteriorating engine performance.
A Systematic Review and Meta-analysis of Endovascular Popliteal Aneurysm Repair Using the Hemobahn/Viabahn Stent-Graft
Authors: Patel Shaneel R. , Hughes Cían O. , Jones Keith G. , Holt Peter J. E. , Thompson Matt M. , Hinchliffe Robert J. , Karthikesalingam Alan
Published: May 2015

Purpose: To perform an evidence synthesis study to assess outcomes of endovascular repair of popliteal artery aneurysms (PAAs) using the Hemobahn or Viabahn stent-graft. Methods: A systematic literature review was conducted conforming to established standards to identify articles published between 1996 (the date of introduction of the Hemobahn stent-graft) and 2013 reporting stent-graft repair of PAAs in at least 10 patients. The data were pooled for Kaplan-Meier analysis of primary and secondary patency rates [presented with 95% confidence intervals (CIs)] as the primary outcomes. Random effects meta-analysis was performed for secondary outcomes that included rates of reintervention, endoleak, stent-graft fracture, and limb salvage. Results: Fourteen studies reported outcomes for 514 PAAs. There was considerable heterogeneity in reporting standards among studies. Pooled primary and secondary patency rates were 69.4% (95% CI 63.3% to 76.2%) and 77.4% (95% CI 70.1% to 85.3%), respectively, at 5 years. Five studies (including only one randomized controlled trial) compared surgical to endovascular repair; no difference was found in primary patency on evidence synthesis (hazard ratio 1.30, 95% CI 0.79 to 12.14, p=0.189). Conclusion: Stent-graft repair provides a feasible treatment option for anatomically suitable PAAs. Further studies are required to optimize both patient selection and follow-up protocols.
Endovascular Repair of a Ruptured Pararenal Aortic Aneurysm Using the Nellix Endovascular Aneurysm Sealing System and Chimney Grafts
Authors: Truijers Maarten , van Sterkenburg Steven M. M. , Lardenoije Jan Willem , Reijnen Michel M. P. J.
Published: May 2015

Purpose: To demonstrate the feasibility of emergent endovascular repair of a ruptured pararenal aneurysm using chimney grafts and the Nellix endovascular aneurysm sealing (EVAS) system to reduce the potential for endoleak from the gutters around the chimney grafts. Case Report: A 74-year-old patient presented with a ruptured pararenal aneurysm. Because of anatomical considerations after previous aortic surgery, conventional endovascular aneurysm repair was deemed impossible. It was decided to exclude the aneurysm with a Nellix EVAS system in conjunction with two chimneys to the renal arteries, even though this was outside the instructions for use of the device. Active bleeding was stopped directly after positioning the chimneys and filling the endobags with polymer. Completion angiography showed aneurysm exclusion and patent renal arteries. Renal function remained stable, and the patient was discharged at the third postoperative day. At 6 months, duplex ultrasound and computed tomography showed patent stents and chimneys and no evidence of endoleak. Conclusion: Using chimney grafts in combination with the Nellix endoprosthesis in a ruptured pararenal aneurysm is feasible. However, more robust data on both chimney-EVAS and EVAS in ruptured cases are required.
Anastomotic False Aneurysm of the Aorta
Authors: Barbetta Iacopo , Giovannacci Luca , Canevascini Reto , van den Berg Jos C.
Published: May 2015

Purpose: To describe the treatment of a noninfected saccular anastomotic false aneurysm (AFA) of the abdominal aorta with the use of a single “sandwiched” coil. Case Report: A 65-year-old man presented with a saccular AFA of the distal anastomosis exactly at the level of the aortic bifurcation 1 month after open abdominal aortic aneurysm repair. Endograft exclusion was not attempted because an aortouni-iliac configuration would have sacrificed a patent iliac axis. Coil embolization was the preferred strategy. Use of 3-dimensional rotational angiography and 3-dimensional roadmap was necessary to cannulate the neck of the AFA. Complete thrombosis and shrinkage of the sac was achieved by “sandwich coiling” of the neck after deployment of a single pushable hydrogel-coated coil. Imaging at 9 months postprocedure showed no sign of the aneurysm sac. Conclusion: This novel technique can be used for selected saccular AFAs with a narrow neck. In such cases, sandwich coiling may avoid sacrifice of a patent iliac axis.
Early Experience With Automatic Pressure-Controlled Cerebrospinal Fluid Drainage During Thoracic Endovascular Aortic Repair
Authors: Kotelis Drosos , Bianchini Claudio , Kovacs Bence , Müller Thomas , Bischoff Moritz , Böckler Dittmar
Published: May 2015

Purpose: To report initial experience with automatic pressure-controlled cerebrospinal fluid drainage (CSFD) during thoracic endovascular aortic repair (TEVAR). Methods: A prospective nonrandomized study enrolled 30 consecutive patients (median age 68 years, range 42–89; 18 men) who underwent TEVAR between March 2012 and July 2013 and were considered to be at high risk for postoperative spinal cord ischemia (SCI), fulfilling 2 of the following criteria: stent-graft length >20 cm, left subclavian artery coverage, and previous infrarenal aortic repair. All patients received perioperative CSFD via the LiquoGuard system. The protocol aimed for a CSF pressure of 10 mm Hg and duration of CSFD of 3 or 7 days in asymptomatic or symptomatic patients, respectively. Muscle strength of the lower extremities was assessed with the Oxford muscle strength grading scale. Results: Completion of the CSFD protocol was achieved in 26 (87%) of 30 patients. CSFD was prematurely stopped due to catheter dislocation in 1 patient and bloody spinal fluid in 3 patients. CSFD was performed for a median of 3 days (range 1–7). Median total CSFD volume was 714 mL (range 13–2369), with a median 192 mL drained per 24 hours. The SCI rate was 3% (1/30). CSFD-related complications were observed in 33% of the patients: 1 fatal intracranial hemorrhage, 3 bloody spinal fluid episodes, 3 persistent CSF leaks requiring epidural blood patch, and 3 post lumbar puncture headaches. Mortality during a median follow-up of 16 months (range 10–25) was 3% (1/30). Conclusion: Prophylactic CSFD was associated with a low SCI rate in a high-risk patient collective undergoing TEVAR. Monitoring and drainage by an automatic modus was feasible, reproducible, and reliable but associated with relevant drainage-associated complications.