bluuebunny/crossref_metadata_2025 huggingface dataset:
The application of a pinless tool in friction stir spot welding: an experimental and numerical study
Authors: Cox Chase D , Aguilar Jason R , Ballun Marjorie C , Strauss Alvin M , Cook George E
Published: May 2014

A pinless friction stir spot welding tool with a scrolled convex shoulder is used to create spot welds on aluminum alloy plates. The effects that the rotation rate, the dwell time, the plunge depth, and the plunge rate have on the spot welding process are investigated. A strong correlation was found to exist between the joint strength versus the tool rotation rate and the joint strength versus the dwell time. Low rotation rates and short dwell times resulted in significantly stronger welds and, conversely, higher rotation rates and longer dwell times resulted in spot welds with hooking defects and lower joint strengths. Using shear tests and macrosection analysis on the spot welds, the dependences of the joint strength, the spindle torque, the temperature and the axial force on the identified process parameters are discussed. A computational fluid dynamics model is created to simulate the effect that the tool rotation rate has on the heat generated and the material flow during spot welding.
Automated manual transmission with a torque gap filler Part 1: kinematic analysis and dynamic analysis
Authors: Amisano Fabrizio , Galvagno Enrico , Velardocchia Mauro , Vigliani Alessandro
Published: May 2014

This paper deals with a powershift automated manual transmission, i.e. an automated manual transmission with a torque gap filler, which essentially integrates, in a typical manual transmission layout, a torque gap filler assembly with the aim of reducing the torque gap that occurs during gearshifts. The torque gap filler consists of an additional mechanical link between the engine and the transmission output shaft, thus enabling the engine power to flow through this parallel path also when the launch clutch is disengaged, with clear benefits in terms of both sportiness and passenger comfort. This paper is the first part of a two-part study which, after a general description of the transmission architecture and its working principle, examines a practical implementation of the torque gap filler concept; the additional mechanical components and their integration into a traditional automated manual transmission are presented. Then, kinematic analysis and dynamic analysis of the transmission are proposed. The evolution of the transmission speeds are studied in the whole working range of the vehicle; the equations of motion are derived and used to show the effect of the torque gap filler on the torque transmitted to the wheels and consequently on the vehicle acceleration during gearshifts. The companion paper (Part 2) covers control issues and provides experimental validation.
Experimental investigations on the increase in nitric oxide emissions using biodiesels and their mitigation
Authors: Jeyaseelan Thangaraja , Krishnasamy Anand , Mehta Pramod S
Published: May 2014

One of the major shortcomings to be addressed in the widespread applications of biodiesel fuel for compression ignition engines is the formation of higher nitric oxide emissions. It is well established in the literature that thermal nitric oxide is a dominant source for nitric oxide formation in engines. Thermal nitric oxide formation increases by any in-cylinder combustion strategy that alters the in-cylinder temperatures, the oxygen fraction or the residence time of high-temperature post-flame burned gases. The differences between the properties of biodiesel in terms of a higher bulk modulus, a higher cetane number and the presence of a fuel-bound oxygen fraction and the properties of diesel are found to affect the in-cylinder charge conditions and thus the nitric oxide formation. The present work aims to understand the major contributor to the higher nitric oxide formation with biodiesel based on experimental investigations in two different engine configurations: one with a conventional mechanical-type injection system and the other with a modern common-rail direct-injection system. The experimental results highlight that the dynamic injection timing advanced up to a maximum of 2.6° crank angle owing to the higher bulk modulus of biodiesel. This factor contributes to specific nitric oxide emissions which are 7.5% higher in an engine having a mechanical-type injection system. The increase in the nitric oxide is neutralized on restoring the injection timing to that of the diesel injection time setting. In the case of an engine with a modern common-rail direct-injection system, the injection timings remain unaltered, and the nitric oxide concentrations for diesel and for biodiesel–diesel blends also remains the same.
Electrical load-sizing methodology to aid conceptual and preliminary design of large commercial aircraft
Authors: Seresinhe Ravinka , Lawson Craig
Published: May 2014

The importance of the more electric aircraft has been highlighted in many publications, projects and industrial presentations. By definition, the more electric aircraft concept achieves the majority of the required system functionality by using electrically powered sub-systems and components. This manifests itself in much higher electrical power demands on-board aircraft, compared to conventional architectures. This presents many challenges in the design process. To alleviate the risk and choose the optimum architectures for the systems on the aircraft, it is essential to incorporate the characteristics and possible configurations of the electrical network in the conceptual and preliminary design stages. Hence the current practice of performing an electrical load analysis at the detailed design stage is not adequate. To address this gap, this paper presents a viable and robust methodology to define requirements, size components and systems and calculates the electric power requirements at the preliminary design stages. The methodology uses the conventional aircraft, systems and components as the baseline and uses mathematical techniques and logical sequences of component operation, developed through the research, to size electrical load profiles for conventional aircraft. It then adapts this result to the more electric aircraft concept by adding key components that would account for the difference between a conventional system and a more electric system. The methodology presented here makes the design process more robust and aids the choice of the optimum design for the aircraft.
Evaluation of the mechanical efficiency of knee orthoses: A combined experimental–numerical approach
Authors: Pierrat Baptiste , Molimard Jérome , Navarro Laurent , Avril Stéphane , Calmels Paul
Published: May 2014

Knee orthotic devices are commonly prescribed by physicians and medical practitioners for preventive or therapeutic purposes with the aim of supporting, aligning or immobilising the joint. However, the evaluation of these devices relies on few biomechanical studies or therapeutic trials and the level of their mechanical actions remain unclear. The objectives of this work are to develop and validate an experimental testing machine regarding its realism as compared to a standardised human limb by using a finite element approach, and then to use this machine to characterise the efficiency of different categories of orthoses under different pathological kinematics and investigate the influence of various design characteristics. It was found that the measured mechanical actions should be corrected to compensate for the rigid design of the test machine. Experimental results showed that the tested orthoses highly differed in their ability to restrain motions and that the stiffening effects of these devices may be able to compensate for deficient internal structures only under low load. Although results remain to be confronted to clinical evidence, this approach paves the way to a standardised procedure for evaluating knee orthoses and developing new designs.
Essential Air Service in the United States
Authors: Grubesic Tony , Wei Ran , Murray Alan , Wei Fangwu
Published: May 2014

The Essential Air Service (EAS) program continues to receive federal funding to provide air travel access to rural communities in the United States. Regular assessment and evaluation of the performance of this program are important, given limited federal resources and fiduciary duties. In fact, this program has garnered significant attention through the years because it was originally conceived to offer temporary financial bridging for maintaining commercial air service in rural and remote communities following deregulation in 1978, yet has continued to be funded at increasing rates for over thirty-five years. This article undertakes a systematic analysis of the EAS program in terms of access and intended goals and objectives. A spatial optimization model is used to examine service performance of the existing system. Program insights as well as ways system efficiency that could be enhanced are highlighted for rural air transportation service in the United States.
Gender Differences in Factors Associated With Prehospital Delay Among Acute Coronary Syndrome Patients in Pakistan
Authors: Allana Saleema , Khowaja Khurshid , Ali Tazeen Saeed , Moser Debra Kay , Khan Aamir Hameed
Published: May 2014

Purpose: To identify gender differences in prehospital delay time (PDT) and its associated factors among acute coronary syndrome (ACS) patients. Design: Descriptive cross-sectional comparative study. Methods: This study was conducted among 249 ACS patients at two tertiary care hospitals of a large metropolitan city of Pakistan. Data were collected through the modified Response to Symptoms Questionnaire. Results: The median PDT of women was found to be 7 hours, compared to 3.5 hours among men ( p = .001). Results of the regression analysis indicated that most women delayed because of social factors, such as attendants’ responses to their symptoms ( p = .002), and because they were worried about expenses required for the treatment ( p = .002); yet, most men delayed owing to individual factors, such as waiting for symptoms to subside ( p< .001), and not recognizing the symptoms as being cardiac related ( p< .001). Having anxiety and lack of knowledge about symptoms was associated with extended PDT among both genders. Conclusion: Women delayed longer than men in seeking treatment for their ACS symptoms. Different factors were associated with PDT in women and men. This study may provide important insights for designing interventional studies to reduce PDT in Pakistani ACS patients.
Transcultural Self-Efficacy Perceptions of Baccalaureate Nursing Students
Authors: Halter Margaret , Grund Faye , Fridline Mark , See Sharon , Young Lisa , Reece Carol
Published: May 2014

Addressing the health care needs of a 21st-century nation that is experiencing increased diversity and disparity will require new models of educating future providers. The cultural competence and confidence model was the guiding framework in a study evaluating the influence of cultural educational offerings on the transcultural self-efficacy (TSE) perceptions in baccalaureate nursing students. The Transcultural Self-Efficacy Tool was used to measure perceived TSE in a pretest ( N = 260), posttest ( N = 236) study over an academic year. Significant changes were demonstrated in overall self-efficacy and on the cognitive, practical, and affective subscales. A classification and regression tree analysis identified social orientation as the demographic variable most predictive of the TSE level. This study supports previous research where positive changes were found in students’ TSE based on the inclusion of cultural interventions in the nursing curriculum.
Mindfulness Revisited
Authors: Purser Ronald E. , Milillo Joseph
Published: May 2014

Recent scholarship on mindfulness has narrowly focused on attention enhancement, present-moment awareness, and its stress reduction effects. Moreover, current operational definitions of mindfulness in the literature differ considerably from those derived from classic Buddhist canonical sources. This article revisits the meaning, function, and purpose of Buddhist mindfulness by proposing a triadic model of “right mindfulness.” A Buddhist-based conceptualization of right mindfulness provides both a theoretical and ethical corrective to the decontextualized individual-level construct of mindfulness that has informed the organizational theory and practitioner literature. We argue that a denatured mindfulness divorced from its soteriological context reduces it to a self-help technique that is easily misappropriated for reproducing corporate and institutional power, employee pacification, and maintenance of toxic organizational cultures.
Efficient pseudo-inverse approach for damage prediction in cold forging process simulation
Authors: Halouani Ali , Li Yuming , Abbès Boussad , Guo Ying-Qiao
Published: May 2014

This article presents an efficient pseudo-inverse approach for the damage prediction in cold forging process simulation. Pseudo-inverse approach combines the advantages of the fast inverse approach and accurate incremental approaches. Some intermediate configurations are created geometrically and corrected mechanically to well describe the deformation path. The formulation of an axi-symmetrical element based on pseudo-inverse approach is presented. A strain-based damage model is introduced in the flow theory of plasticity. A direct scalar integration algorithm of plasticity-damage is developed, leading to a fast and robust algorithm for large strain increments. The cold forging processes of two axi-symmetrical parts are simulated to validate pseudo-inverse approach by the incremental approach ABAQUS/Explicit. Pseudo-inverse approach gives very good results, but uses much less CPU time.
Work as a Calling in China
Authors: Zhang Chunyu , Dik Bryan J. , Wei Jia , Zhang Jinfu
Published: May 2014

This study explored how the perception of work as a calling, a construct with a long history in Western culture, is experienced within Chinese culture. A qualitative study was conducted with 210 Chinese college students. Using emergent qualitative document analysis, results revealed four dimensions of general calling and career-related calling: Guiding Force, Meaning and Purpose, Altruism, and Active Tendency. These results largely converge with those found using samples within Western cultures, although the label “sense of duty” was found to be a unique and salient aspect of calling among Chinese college students. Results also revealed that effect of calling was not always positive. This study provides the first evidence that many aspects of the multidimensional construct of calling may be shared within Chinese culture, at least with college student participants. Implications for research and practice are explored.
Vibration reduction in a periodic truss beam carrying locally resonant oscillators
Authors: Chen Rong , Wu Tianxing
Published: May 2014

A periodic truss beam is designed by connecting an array of identical elements in parallel to gain excellent Bragg band gaps, after which locally resonant (LR) oscillators are attached to the truss beam to form the periodic LR truss beam, which can achieve both an LR gap in low frequency and Bragg gaps in high frequency. Firstly, dynamic models of the periodic LR truss beams in which longitudinal and flexural waves propagate are established. Then, transfer matrices of the periodic elements are derived by using the transfer matrix method and are further used for computing frequency-dependent propagation constants and acceleration frequency response (AFR) on semi-infinite and finite periodic LR truss beams. Furthermore, vibration reduction performance of the periodic structures in the frequency range below 1400 Hz is numerically analyzed in detail. Finally, an experimental setup for measuring AFR on the periodic LR truss beam is carried out to validate the predicted numerical results. Both the numerical simulation and experimental results reveal that the LR gap in low frequency and the Bragg gap in high frequency coexist in the periodic LR truss beam; within the frequency ranges of the two types of band gaps, vibration transmitted in the periodic structure can be substantially attenuated.
Nonlinear free vibration of an Euler-Bernoulli composite beam undergoing finite strain subjected to different boundary conditions
Authors: Ghasemi AR , Taheri-Behrooz F , Farahani SMN , Mohandes M
Published: May 2014

In this paper, the free vibration of an orthotropic beam undergoing finite strain are studied. The second Piola-Kirchhoff stress tensor and Green-Lagrange strain tensor according to finite strain assumption were used to obtain Euler-Bernoulli beam governing equations. The Galerkin method and Generalized Differential Quadrature method were employed for solving the governing equations and boundary condition. The effect of beam thickness and different boundary conditions were considered in finite strain formulation of the beam equations. Natural frequencies of different composite materials are obtained and compared. The results revealed that by increasing the beams thickness, the difference between maximum vibration amplitude increased between von Karman and finite strain formulations. Also, in a beam with simply- simply supports, differences between linear and non linear mode shapes was remarkable.
Detection and monitoring of side crack in a rectangular plate using mobility
Authors: Bose Tanmoy , Mohanty Amiya R
Published: May 2014

Here, forced vibration of a rectangular plate with a side crack of arbitrary length, orientation and position is studied by the Ritz method. Simply supported and clamped boundary conditions are used in the analysis. Numerical results obtained from the Ritz method are validated by finite element method software (ABAQUS). Good matching was found for first five modes. Mobility curves are presented for variation in force location, crack length, crack orientation and crack position in a square plate. Normalized mobility is found to increase with an increase in crack length ratios and decrease with an increase in crack angle. Again, it is observed that a change in crack position from side towards middle increases the normalized mobility. The results can be used for mobility-based crack detection.
Axial active magnetic bearing design
Authors: Barbaraci Gabriele
Published: May 2014

The purpose of this paper is to propose a useful method to implement active magnetic bearings (AMBs) on an existing rotating shaft which rotates on conventional bearings. This is feasible if AMBs can produce the same reaction loads of conventional ones and if the size of the vane is large enough to host an AMB. As this substitution could give some difficulties due to the different size between magnetic bearings and conventional ones, a set of equations are performed to show that a variation of some parameters can solve this problem. The coil ratio is the geometrical parameter introduced to develop the present analysis. The variation of coil ratio does not produce a variation of the pole’s surface so that the reaction load does not change. The results are analyzed by numerical analysis by mathematical relationships involving the design parameters, magneto-static simulations and dynamic simulation on the shaft when it is tested by a step response and performing frequency response parameterized with coil ratio. Results show that the displacement carried out by the step response is always the same, when the journal ratio and frequency response are varied, confirming that the reaction load, produced by pole expansion, remains the same when the coil ratio varies. The simulations and results are performed by finite element method magnetic and MATLab software.
Pretzel Logic
Authors: Dutkiewicz Jan
Published: May 2014

Rock climbing entails far more than simply climbing rocks. Modern sport climbing is, rather, rooted in the myriad ways in which climbers engage with rock climbs, the specific human-made spaces mapped onto the cliff faces that athletes seek to ascend. This interaction includes forms of learning to read and create visual representations of climbs, physically training to prepare their bodies and hone their techniques, learning how to haptically and kinaesthetically engage with and learn from the rock, and overall developing a climbing-specific habitus. By exploring the relationship between a number of climbers and a climb in Rumney, New Hampshire, called Pretzel Logic, this article argues that the climb and climber are mutually constituted through a highly fluid actor–object engagement rooted in ongoing learning and adaptation. By extension, this article argues that interaction with objects—and not solely other humans—can be central to the formation of habitus and bodily practice.
Analysis of tribological performance of biodiesel
Authors: Kumar N , Varun  , Chauhan S
Published: May 2014

Biodiesel is a promising alternative among the different fuels put forward as a substitute for diesel fuel. One important issue in internal combustion engines is the lubrication of the equipments which are lubricated by the fuel itself. Previous studies have shown that biodiesel possesses excellent inherent lubricity. However, biodiesel is susceptible to oxidation reactions due to the presence of unsaturation in its moiety. These reactions are accelerated in the presence of oxygen and high temperatures and may alter the lubrication characteristics. In this particular research work, an investigation has been made to assess the impact of load, temperature, and biodiesel concentration upon friction and wear in the four-ball wear machine. The effect of individual parameter utilizing other biodiesels has already been presented elsewhere. The current study demonstrates the response of biodiesel and oxidized biodiesel with combined variation of operating parameters. The selected temperatures and loads were 45–60–75 ℃ and 40–50–60 kg, respectively. The tests were conducted with diesel (B0), B20 (20% jatropha methyl ester by volume), B40, B100, and oxidized biodiesel. It was found that these variables not only individually but also collectively affect the tribological performance of biodiesel.
Synthesis and characterization of rapeseed oil bio-lubricant dispersed with nano copper oxide: Its effect on wear and frictional behavior of piston ring–cylinder liner combination
Authors: Arumugam S , Sriram G
Published: May 2014

Direct application of vegetable oil as automotive lubricants is less favorable due to its poor thermo-oxidative stability, cold flow behavior, and poor anti-wear characteristics. The investigation detailed in this paper pertains to chemical modification of rapeseed oil through epoxidation, hydroxylation, and esterification processes in order to improve its thermo-oxidative stability and cold flow behavior. The copper oxide (CuO) nanoparticles of size ∼40–70 nm was dispersed in chemically modified rapeseed oil (CMRO) in three different concentrations (0.1 wt%, 0.5 wt%, and 1 wt%) as an anti-wear additive using an ultrasonic sonicator. The tribological behavior of cylinder liner against piston ring segment was tested with CMRO with and without CuO nano-additive using high frequency reciprocating rig tribometer. The morphological characterization of CuO nanoparticles dispersed in CMRO was done using scanning electron microscopy and X-ray diffraction analysis. The results were also compared with commercial synthetic lubricant under the same operating conditions. The atomic force microscopy and scanning electron microscopic analyses proved that the surface morphology of tested cylinder liner surfaces are smooth with optimum concentration of 0.5 wt% CuO nanoparticles dispersed in CMRO.
“Where I have to learn the ways how to live:” Youth resilience in a Yup’ik village in Alaska
Authors: Rasmus Stacy M. , Allen James , Ford Tara
Published: May 2014

What is it like to grow up Yup’ik and come of age today in a traditional hunting-gathering community setting located in a remote region of Alaska? Current research describes a contemporary experience often laden with trauma and crisis. Youth in Yup’ik communities today face threats to their very survival as they encounter, early on, things that their ancestors never faced—including alcohol-related deaths, violence in many forms, and high rates of suicide among their young peers. Yet all is not despair for the youth growing up in these remote indigenous communities. Many youth grow-up to become skilled hunters, strong leaders, and able parents. This paper reports findings from the Alaskan Yup’ik site of the Circumpolar Indigenous Pathways to Adulthood (CIPA) study. The goal of this study is to identify strengths and resilience in youth living in a Yup’ik community in southwest Alaska. Interviews were conducted with 25 youth age 11–18, currently residing in a southwest Alaska community. Qualitative analysis revealed important connections between local stressors, community-level protective resources, and youth-driven, solution-focused strategies for overcoming hardship and learning the “ways how to live.” Findings from this study contribute critical information on indigenous youth protection and resilience, including community and cultural resilience processes beyond the individual level, and enhance our understanding of the types of resources that can lead to improved outcomes for Alaska Native youth.
What characterizes persons with poor mental health? A nationwide study in Denmark
Authors: Christensen Anne Illemann , Davidsen Michael , Kjøller Mette , Juel Knud
Published: May 2014

Background: The aim of the study was to identify and characterize groups with poor mental health defined by the SF-12 Mental Component Summary (MCS-12) scale. Methods: The study is based on the Danish Health and Morbidity Survey 2005 and includes 10,082 participants (16 years or older). Data were analysed by means of logistic regression models. Results: Men and women with poor mental health are characterized by being single, having a long-term illness, not being able to rely on help from others in case of illness and by feeling that family and friends demand too much of them. Men with poor mental health were further characterized by being a heavy smoker, and having a BMI below 25. Women with poor mental health were further characterized by being 16–44 years old and sedentary in leisure time. Conclusions: The prevalence of poor mental health is higher among women than men, and different factors characterize men and women with poor mental health. The present findings support the notion that both socio-demographics and lifestyle factors are independently related with poor mental health. We suggest taking into account all these areas of life when planning activities to prevent poor mental health and when promoting mental health.
“Bean’s World”: (Mine) Crafting affective atmospheres of gameplay, learning, and care in a children’s hospital
Authors: Hollett Ty , Ehret Christian
Published: May 2014

This article contributes to research on the felt-experience of new media. It describes how the body’s corporal capacities are augmented through one 12-year-old boy’s play of the video game, Minecraft, while hospitalized. Expanding player-centric perspectives of video gameplay, the authors leverage work on place-events to develop an intra-actional methodology aligned with their relational materialist analysis. Their analysis illuminates how multiple human and nonhuman bodies become entangled in gameplace-events and potentially generate affective atmospheres. Analysis shows how these atmospheres reverberate and adhere within social space, revealing experiences of new media as less a one-to-one transaction between player and game and more an affective experience felt across multiple bodies and temporalities. Implications, suggesting both how intimate atmospheres developed during gameplay and how those atmospheres (re)shaped care in the hospital, point toward new media’s potential to engage users in uniquely meaningful felt-experiences made visible—and felt—through methods of intra-action and relational materialism.
A republican account of the value of privacy
Authors: Roberts Andrew
Published: May 2014

This article provides an account of the value of privacy in securing the republican aims of self-government and conditions of non-domination. It describes how loss of privacy might lead to subjugation to dominating power. The republican concept of domination provides the foundation of a broad and coherent account of the value of privacy. One that encompasses circumstances in which the subject (i) suffers interference as a result of the loss, (ii) is aware that he has suffered a loss of privacy, but suffers no subsequent interference and (iii) is unaware that he has suffered any loss of privacy, and suffers no subsequent interference. Liberal accounts explain the value of privacy in the first two circumstances by pointing to the possible effect of the loss on the autonomy of the subject, but because they focus on autonomy are unable to explain why privacy is valuable where an agent is unaware of the loss. The republican account provided here explains why loss is harmful in all three circumstances. The final part of the article argues that because privacy is a pre-requisite for effective participation in political life, and republicans consider such participation to be the essence of self-government and the means through which a polity can secure conditions of freedom, in a republican democracy individual privacy will be seen as a collective good.
Modelling stiffened plate panels in computer-aided ship design
Authors: Ventura Manuel , Guedes Soares C
Published: May 2014

Different configurations of stiffened panels used in shipbuilding are analysed. From this analysis, data models are produced and a description is given of the functionalities required for their generation as solid models. The methodologies for their geometric definition and representation are presented for application in systems in which the hull-moulded shape is described by parametric surfaces. The concepts presented provide the basis for the implementation of a tool for the creation of stiffened panels, which is to be a general-purpose component in a computer-aided ship design system.
Win at All Costs or Lose Gracefully in High-Stakes Competition? Gender Differences in Professional Tennis
Authors: Anbarci Nejat , Lee Jungmin , Ulker Aydogan
Published: May 2014

This article examines line-call challenges by male and female professional tennis players in major tournaments around the world. In terms of utilization rates, we find that the genders behave similarly. Nevertheless, we do detect some intriguing gender differences in these challenges. First, male players’ challenges are more likely to be provoked by those of their opponents. More importantly, at tiebreaks, females are more likely to reverse an umpire’s unfavorable call, while males make relatively more unsuccessful challenges. Furthermore, we find that men are a lot more likely to make “embarrassing” line-call challenges at tiebreaks and offenses (i.e., when the shot lands at the opponent’s side of the tennis court) than women. These significant gender differences suggest that women particularly diverge from men at crucial junctures of the match such as tiebreaks. Differences in factors such as risk aversion, overconfidence, pride, shame, and strategic signalling behavior might help us to explain these gender-difference findings in line call challenges.
Emotional Processing, P50 Sensory Gating, and Social Functioning in Bipolar Disorder
Authors: Vuillier Laura , Hermens Daniel F. , Chitty Kate , Wang Chenyu , Kaur Manreena , Ward Philip B. , Degabriele Rachael , Hickie Ian B. , Lagopoulos Jim
Published: May 2014

Emotional processing has been reported to effect sensory gating as measured by the event-related potential known as P50. Because both P50 and emotional processing are dysfunctional in bipolar disorder (BD), we sought to investigate the impact that concurrent emotional processing has on sensory gating in this psychiatric population. P50 was recorded using a paired-click paradigm. Peak-to-peak amplitudes for stimulus 1 (S1) and stimulus 2 (S2) were acquired during the presentation of disgust and neutral faces to young adults with BD (n = 19) and controls (n = 20). Social functioning and quality-of-life self-reported measures were also obtained. The BD group had significantly larger P50 amplitudes elicited by the S2-disgust response compared with controls, but no significant difference in overall P50 sensory gating was found between the groups. There were also no differences between groups in S1-disgust or in either of the neutral P50 amplitudes. The BD group showed significant associations between sensory gating to disgust and measures of social functioning. Importantly, BD showed impaired filtering of auditory information when paired with an emotionally salient image. Thus, it appears that patients with the greatest impairment in sensory gating also have the most difficulty engaging in social situations.
Acute liver function decompensation in a patient with sickle cell disease managed with exchange transfusion and endoscopic retrograde cholangiography
Authors: Papafragkakis Haris , Ona Mel A. , Changela Kinesh , Sadanandan Swayamprabha , Jelin Abraham , Anand Sury , Duddempudi Sushil
Published: May 2014

Sickle cell intrahepatic cholestasis is a relatively uncommon complication of homozygous sickle cell anemia, which may lead to acute hepatic failure and death. Treatment is mainly supportive, but exchange transfusion is used as salvage therapy in life threatening situations. We describe a case of a 16-year-old female with homozygous sickle cell anemia who presented to the emergency room with fatigue, malaise, dark urine, lower back pain, scleral icterus and jaundice. She was found to have marked hyperbilirubinemia, which persisted after exchange transfusion. Because of the concomitant presence of gallstones and choledocholithiasis, the patient underwent endoscopic ultrasound and laparoscopic cholecystectomy followed by endoscopic retrograde cholangiography and sphincterotomy.
Evaluation of the Utility of a Glycemic Pattern Identification System
Authors: Otto Erik A. , Tannan Vinay
Published: May 2014

Background:

With the increasing prevalence of systems allowing automated, real-time transmission of blood glucose data there is a need for pattern recognition techniques that can inform of deleterious patterns in glycemic control when people test. We evaluated the utility of pattern identification with a novel pattern identification system named Vigilant™ and compared it to standard pattern identification methods in diabetes.

Method:

To characterize the importance of an identified pattern we evaluated the relative risk of future hypoglycemic and hyperglycemic events in diurnal periods following identification of a pattern in a data set of 536 patients with diabetes. We evaluated events 2 days, 7 days, 30 days, and 61-90 days from pattern identification, across diabetes types and cohorts of glycemic control, and also compared the system to 6 pattern identification methods consisting of deleterious event counts and percentages over 5-, 14-, and 30-day windows.

Results:

Episodes of hypoglycemia, hyperglycemia, severe hypoglycemia, and severe hyperglycemia were 120%, 46%, 123%, and 76% more likely after pattern identification, respectively, compared to periods when no pattern was identified. The system was also significantly more predictive of deleterious events than other pattern identification methods evaluated, and was persistently predictive up to 3 months after pattern identification.

Conclusions:

The system identified patterns that are significantly predictive of deleterious glycemic events, and more so relative to many pattern identification methods used in diabetes management today. Further study will inform how improved pattern identification can lead to improved glycemic control.
Application of PK/PD Modeling and Simulation to Dosing Regimen Optimization of High-Dose Human Regular U-500 Insulin
Authors: de la Peña Amparo , Ma Xiaosu , Reddy Shobha , Ovalle Fernando , Bergenstal Richard M. , Jackson Jeffrey A.
Published: May 2014

Background:

Pharmacokinetic/pharmacodynamic (PK/PD) studies of human regular U-500 insulin (U-500R) at high doses commonly used in clinical practice (>100 units) have not been performed. The current analysis applied PK/PD modeling/simulation to fit the data and simulate single-dose and steady-state PK/PD of U-500R high-dose regimens.

Method:

Data from 3 single-dose euglycemic clamp studies in healthy obese and normal-weight patients, and normal-weight patients with type 1 diabetes were used to build the model. The model was sequential (PK inputs fed into PD component). PK was described using a 1-compartment model with first-order absorption and elimination. The model estimated separate absorption rate constants for U-500R and human regular U-100 insulin. The PD component used an effect compartment model, parameterized in terms of maximum pharmacologic effect (Emax) and concentration to achieve 50% of Emax.

Results:

The model described the data well. Steady-state PK for once-daily (QD), twice-daily (BID), or thrice-daily (TID) administration appeared to be reached 24 hours after the first dose. At steady-state, QD dosing showed the greatest fluctuations in PK/PD. BID dosing showed a gradual increase in insulin action with each dose and a fairly stable basal insulin effect. For TID dosing, activity was maintained throughout the dosing interval.

Conclusions:

PK/PD modeling/simulation of high U-500R doses supports BID or TID administration with an extended duration of activity relative to QD. TID dosing may provide slightly better full-day insulin effect. Additional PK/PD studies and randomized controlled trials of U-500R are needed to validate model predictions in patients with insulin-resistant diabetes requiring high-dose insulin.
Characterizing Normal-use Temperature Conditions of Pumped Insulin
Authors: Herr Joshua K. , Keith Steven , Klug Rick , Pettis Ronald J.
Published: May 2014

In this study, the temperature profiles of insulin pump reservoirs during normal wear conditions across multiple seasons were characterized. Thermocouples secured in reservoirs filled with insulin diluent were loaded in infusion pumps worn by volunteers. Reservoir and ambient environmental temperature data and activity levels were logged during the course of normal daily activities in February (winter), April (spring), and August (summer). Each seasonal data set comprised 7 to 14 days of wear from 3 to 5 volunteers. Reservoir temperature profiles were generally higher than ambient temperatures, likely due to heat transfer from the wearer when the pump was placed close to the body. Temperature conditions inside pump reservoirs fluctuated between 25°C and 37°C regardless of seasonal variations. The average reservoir temperature remained close to 30°C across all seasons, notably lower than used in previously published compatibility and stability protocols (37°C). Results from this study could be utilized to develop more accurate stability and compatibility testing procedures for new insulin formulations and/or delivery devices.
A Study of Patient Experience Using a Blood Glucose Meter With an In-Built Insulin Dose Calculator
Authors: Ramtoola Shenaz , Jude Edward , Robinson Anthony , Malik Iqbal , Rayman Gerrard , Dang Cuong , Martin Graham David Ross , Ali Amar
Published: May 2014

Background:

Accurate calculation and adjustment of insulin doses is integral to maintaining glycemic control in insulin treated patients. Difficulties with insulin dose calculations may lead to poor adherence to blood glucose monitoring and insulin treatment regimes, resulting in poor metabolic control. The main objective of this study was to evaluate ease of use and user preference of a high specification touch screen blood glucose meter, which has an in-built insulin calculator, compared to patients’ usual method of testing blood glucose and deciding insulin doses.

Methods:

Patients with diabetes on a multiple daily injection insulin regime used the Test Meter without the insulin calculator and 1 of 3 comparator meters, each for a 7-day period. They then used the Test Meter with the in-built calculator for 10 days. Patients completed an ease of use questionnaire after each 7-day period, a preference questionnaire after the second 7-day period, and a questionnaire comparing the Test Meter with their usual method after the final 10-day period.

Results:

Of 164 patients who completed the study, 76% stated a preference for the Test Meter as a diabetes management tool compared to their usual method. A small number of patients preferred familiar methods and/or calculating insulin doses themselves. The log book function of meters was important to most patients.

Conclusions:

The Test Meter system with in-built insulin calculator supports people to better manage their diabetes and increases their confidence. Patients have different needs and preferences which should be acknowledged and supported in a patient centered health service.
Use of the DISST Model to Estimate the HOMA and Matsuda Indexes Using Only a Basal Insulin Assay
Authors: Davidson Shaun M. , Docherty Paul D. , Chase J. Geoffrey
Published: May 2014

Background:

It is hypothesized that early detection of reduced insulin sensitivity ( SI) could prompt intervention that may reduce the considerable financial strain type 2 diabetes mellitus (T2DM) places on global health care. Reduction of the cost of already inexpensive SI metrics such as the Matsuda and HOMA indexes would enable more widespread, economically feasible use of these metrics for screening. The goal of this research was to determine a means of reducing the number of insulin samples and therefore the cost required to provide an accurate Matsuda Index value.

Method:

The Dynamic Insulin Sensitivity and Secretion Test (DISST) model was used with the glucose and basal insulin measurements from an Oral Glucose Tolerance Test (OGTT) to predict patient insulin responses. The insulin response to the OGTT was determined via population based regression analysis that incorporated the 60-minute glucose and basal insulin values.

Results:

The proposed method derived accurate and precise Matsuda Indices as compared to the fully sampled Matsuda ( R = .95) using only the basal assay insulin-level data and 4 glucose measurements. Using a model employing the basal insulin also allows for determination of the 1-day HOMA value.

Conclusion:

The DISST model was successfully modified to allow for the accurate prediction an individual’s insulin response to the OGTT. In turn, this enabled highly accurate and precise estimation of a Matsuda Index using only the glucose and basal insulin assays. As insulin assays account for the majority of the cost of the Matsuda Index, this model offers a significant reduction in assay cost.
Clinical Evaluation of a Novel On-Strip Calibration Method for Blood Glucose Measurement
Authors: Noble Michael , Rippeth John , Edington David , Rayman Gerry , Brandon-Jones Sarah , Hollowood Zoe , Kew Simon
Published: May 2014

Background:

This study evaluated a novel technology for improving accuracy of self-monitoring of blood glucose (SMBG). The technology calibrates each and every test by measuring the response from a predetermined amount of glucose present in the sample chamber of each test strip.

Method:

SMBG test strips were modified to include a lid coated with a fast dissolving formulation containing glucose. These test strips were characterized for hematocrit (Hct) and temperature induced error response to develop a calibration algorithm. The modified test strips were used in a clinical evaluation involving fingerstick blood samples from 160 subjects.

Results:

Experiments involving Hct and temperature induced errors show that the technology generates a signal characteristic of the error conditions in any particular test, but independent of glucose concentration, allowing a correction algorithm to be derived. The approach substantially reduced Hct and temperature derived errors. Clinical evaluation using fingerstick blood directly applied to prototype strips showed the error (measured as MARD) was reduced from 11.1 to 5.9% by the on-strip correction approach and the number of outliers reduced by approximately 90%.

Conclusion:

This technology could improve the accuracy and precision of glucose monitoring systems and so reduce decision errors particularly in clinical situations where hematocrit and temperature may be significant confounders.
Translating science for decision makers to help navigate the Anthropocene
Authors: Barnosky Anthony D , Hadly Elizabeth A , Dirzo Rodolfo , Fortelius Mikael , Stenseth Nils Chr
Published: May 2014

Although scientists typically regard their work as finished with publication in an academic journal, in fact that is just the beginning if the goal is to help society solve problems. This is particularly true for the environmental sciences, in which a generation of scientists has documented that five interacting human impacts are causing undesirable planetary changes: climate change, extinctions, loss of ecosystems not dominated by humans, pollution, and over-population and consumption. Dealing with such issues requires active engagement of scientists with politicians and other leaders as well as the public-at-large. Here we report on the positive outcomes of one such engagement, The Scientific Consensus on Maintaining Humanity’s Life Support Systems in the 21st Century: Information for Policy Makers ( http://consensusforaction.stanford.edu/ ), which was published in a previous issue of The Anthropocene Review. We suggest that effective communication outside the academic sphere will be increasingly important in navigating environmental challenges in the Anthropocene.
Platelets are required for enhanced activation of the endothelium and fibrinogen in a mouse thrombosis model of APS
Authors: Proulle Valerie , Furie Richard A. , Merrill-Skoloff Glenn , Furie Barbara C. , Furie Bruce
Published: May 2014

Key Points

The anti-β2GP1 autoantibody/β2GP1 complex binds to the platelet thrombus, amplifying platelet activation. Platelets are required for enhanced activation of the endothelium and fibrin generation by the anti-β2GP1 autoantibody/β2GP1 complex.
Sharp bounds for the arithmetic-geometric mean
Authors: Yang Zhen-Hang , Song Ying-Qing , Chu Yu-Ming
Published: May 2014

In this article, we establish some new inequality chains for the ratio of certain bivariate means, and we present several sharp bounds for the arithmetic-geometric mean.

MSC:26E60, 26D07, 33E05.