cssi/SciSciGPT-SciSciNet huggingface dataset:
Error in the determination of the deformed shape of prismatic beams using the double integration of curvature

The deformed shape is a consequence of loading the structure and it is defined by the shape of the centroid line of the beam after deformation. The deformed shape is a universal parameter of beam-like structures. It is correlated with the curvature of the cross-section; therefore, any unusual behavior that affects the curvature is reflected through the deformed shape. Excessive deformations cause user discomfort, damage to adjacent structural members, and may ultimately lead to issues in structural safety. However, direct long-term monitoring of the deformed shape in real-life settings is challenging, and an alternative is indirect determination of the deformed shape based on curvature monitoring. The challenge of the latter is an accurate evaluation of error in the deformed shape determination, which is directly correlated with the number of sensors needed to achieve the desired accuracy. The aim of this paper is to study the deformed shape evaluated by numerical double integration of the monitored curvature distribution along the beam, and create a method to predict the associated errors and suggest the number of sensors needed to achieve the desired accuracy. The error due to the accuracy in the curvature measurement is evaluated within the scope of this work. Additionally, the error due to the numerical integration is evaluated. This error depends on the load case (i.e., the shape of the curvature diagram), the magnitude of curvature, and the density of the sensor network. The method is tested on a laboratory specimen and a real structure. In a laboratory setting, the double integration is in excellent agreement with the beam theory solution which was within the predicted error limits of the numerical integration. Consistent results are also achieved on a real structure—Streicker Bridge on Princeton University campus.
The use of intermuscular coherence analysis as a novel approach to detect age-related changes on postural muscle synergy.

Abstract The overall goal of this study was to investigate potential adaptations brought about by the natural processes of aging on the coordination of postural muscles. Considering the progressive and non-homogeneous deterioration of sensorimotor and neuromuscular systems as the individual grows older, it was hypothesized that aging is associated with a reorganization of synergistic mechanisms controlling postural muscles. Therefore, the presence, distribution, and strength of correlated neural inputs to three posterior postural muscles were measured by intermuscular coherence estimations at a low frequency band (0–55 Hz). Nine healthy young adults and thirteen healthy older adults performed ten trials of a perturbed task: bipedal stance while holding a five kg load for fifteen seconds. Estimates of intermuscular coherence for each pair of electromyographic signals (soleus and biceps femoris, soleus and erector spinae, and biceps femoris and erector spinae) were computed. Results revealed significantly stronger levels of synchronization of posterior muscles within 0–10 Hz in seniors compared to young adults. In addition, seniors presented similar spectra of intermuscular coherence within 0–55 Hz for all three muscle pairs analyzed. These findings provide valuable information regarding compensatory mechanisms adopted by older adults to control balance. The age-related reorganization of neural drive controlling posterior postural muscles revealing a stronger synchronization within 0–10 Hz might be related to the faster body sway and muscle co-activation patterns usually observed in this population. Finally, this study supports the use of Intermuscular Coherence Analysis as a sensitive method to detect age-related changes in multi-muscle control.
Was There a Pan-European Orientalism? Icelandic and Flemish Perspectives on Captivity in Muslim North Africa (1628–1656)

A comparison of Icelandic and Flemish seventeenth-century narratives of North African captivity demonstrates the existence of a pan-European discourse on the Muslim world born out of specifically Mediterranean experiences. This discourse blends negative Orientalist tropes and tolerant proto-ethnography, indicating the need for a critical approach that combines Orientalism with Mediterranean Studies.
US labour unions and green transitions: depth, breadth, and worker agency

The goal of this article is to interpret and analyse two ambitious and prominent cases of labour environmentalism in the USA – the par excellence example of liberal capitalism. In order to capture ...
The Biological Mechanisms by Which Physical Activity Might Have an Impact on Outcome/Prognosis After a Breast Cancer Diagnosis

Despite the growing body of observational evidence suggesting a link between PA and breast cancer survival, the mechanisms underlying this relationship are poorly understood. A few small RCTs have examined the impact of exercise on surrogate/biological markers of survival. The beneficial effects of PA may be mediated through a reduction in body fat and beneficial changes in metabolic (e.g., insulin) and sex hormones (e.g., androgens and estrogens), growth factors (IGF-I and associated binding proteins, e.g., IGFBP-3), adipokines (e.g., leptin, adiponectin), and/or inflammation (e.g., CRP). Although much further research is needed to determine the effect of PA on these biological markers, we posit that PA decreases breast cancer death directly and indirectly through multiple, interrelated actions of body fat levels and/or hormonal concentrations and actions. Given the high level of physical inactivity in the population, and the heavy burden that breast cancer creates for the individual and for society, the need for well-designed trials of exercise on breast cancer survival and surrogate/biological markers mediating a potential effect is an urgent public health priority.
Decreases in Maximal Oxygen Uptake Among Army Reserve Officers’ Training Corps Cadets Following Three Months Without Mandatory Physical Training

During the academic year, Army ROTC cadets are required to participate in mandatory physical training; however, during summer months training is not required. The purpose of this study was to determine if there is a change in cadet VO2max after the summer when training is not mandatory. Participants completed a graded exercise treadmill test to determine their VO2max in late spring of 2010 and again in early fall of 2010. Results indicated that over a three-month break from mandatory physical training, a significant decrease in VO2max was seen for both genders in ROTC cadets.
High Performance Parallel Database Management Systems

Parallelism is the key to realizing high performance, scalable, fault tolerant database management systems. With the predicted future database sizes and complexity of queries, the scalability of these systems to hundreds and thousands of nodes is essential for satisfying the projected demand. This paper describes three key components of a high performance parallel database management system. First, data partitioning strategies that distribute the workload of a table across the available nodes while minimizing the overhead of parallelism. Second, algorithms for parallel processing of a join operator. Third, ORE as a framework that controls the placement of data to respond to changing workloads and evolving hardware platforms.
Analyzing Epipolar Geometry of 2-D Forward-Scan Sonar Stereo for Matching and 3-D Reconstruction

New generation of underwater 2-D forward-look sonar video systems operating at over 1 MHz frequency offer images with enhanced target detail. Within limited range of only tens of meters, they are the most suitable imaging systems for conducting visually guided missions in turbid waters. The reconstruction of 3-D target shapes or simply establishing the 3-D spatial location of interest points is a highly desired capability for automating many tasks. As achieved with 2-D optical images, multiple images from nearby positions may be utilized. This paper investigates some key issues in the accurate estimation of 3-D point locations from overlapping images of two forward-scan (FS) sonar systems in stereo configuration. We first present a stereo calibration algorithm and assess its accuracy. We then analyze the sonar stereo epipolar geometry. Beyond reducing the correspondence problem to a 1-D search along epipolar curves, this reveals unique properties associated with sonar measurements of range and azimuth angle. In particular, the search window to locate feature matches can vary significantly with stereo geometry, posing key tradeoffs. These issues are demonstrate using representative examples, and experiments with real data.
Complexity, Statistical Risk, and Metric Entropy of Deep Nets Using Total Path Variation.

For any ReLU network there is a representation in which the sum of the absolute values of the weights into each node is exactly $1$, and the input layer variables are multiplied by a value $V$ coinciding with the total variation of the path weights. Implications are given for Gaussian complexity, Rademacher complexity, statistical risk, and metric entropy, all of which are shown to be proportional to $V$. There is no dependence on the number of nodes per layer, except for the number of inputs $d$. For estimation with sub-Gaussian noise, the mean square generalization error bounds that can be obtained are of order $V \sqrt{L + \log d}/\sqrt{n}$, where $L$ is the number of layers and $n$ is the sample size.
Developing Rehabilitation Practices Using Virtual Reality Exergaming

Patients with Spinal Cord Injury (SCI) have limited time with supervised therapy in rehabilitation hospitals. This makes it imperative for them to continue regular therapy at home so they can maximize motor recovery especially for performing Activities of Daily Living (ADL). However physical therapy can be tedious and frustrating leading to a lack of motivation. Motivation is often provided in the form of games. However, commercial gaming systems do not account for the vast differences between what is considered “normal movement” and what a tetraplegic individual can perform. We explore the use of a virtual reality exergame using the HTC Vive to gauge motivation, engagement, and quantify range of motion.
The Role of Integrin αvβ3 in Cell Survival and Angiogenesis

The outgrowth of vasculature from pre-existing blood vessels is known as angiogenesis. The formation of new blood vessels facilitates physiological processes of embryonic development, the female reproductive cycle and wound-healing (Folkman (1995)). However, deregulated angiogenesis plays a critical role in various pathological mechanisms such as solid tumor formation, metastasis, childhood hemangiomas, diabetic retinopathy, macular degeneration, psoriasis and in inflammation related diseases such as rheumatoid arthritis, osteoarthritis and ulcerative colitis (Folkman (1995)). In particular, the expansion of solid tumors beyond a minimal size is critically dependent on neovascularization to supply oxygen, nutrients and growth factors. Angiogenesis is also crucial for the formation of metastases at secondary sites and accordingly, the degree of vascularization of certain tumors is correlated with a poor clinical prognosis and an increased risk of metastasis (Wedner (1995)).
Interventions to support family caregivers of people living with dementia in high, middle and low-income countries in Asia: a scoping review.

Introduction Despite increasing numbers of persons living with Alzheimer’s disease and Alzheimer’s-related dementias (AD/ADRD) in Asia, particularly in low-income countries (LIC) and middle-income countries (MIC), surprisingly little is known about the current state of the evidence for family caregiver interventions. The objectives of this scoping review were to: (1) describe the evidence for efficacy of family dementia-caregiver psychosocial interventions in Asian countries, (2) compare evidence across LIC, MIC, and high-income countries (HIC), and (3) characterise cultural adaptions to interventions developed outside Asia. Methods The inclusion criteria included: (1) conducted in Asia (2) included an intervention delivered to a family caregiver of a person living with AD/ADRD, (3) reported quantitative outcomes for the family caregiver and (4) published in a peer-reviewed journal with full text available in English. Results Thirty intervention trials were identified meeting inclusion criteria and all reported statistically significant (p Conclusion This scoping review found substantial evidence, particularly from high-income Asian countries, that a wide range of interventions improve AD/ADRD family caregiver outcomes. However, critical knowledge gaps exist, particularly for LIC and MIC in Asia, where the number of persons with dementia is numerically largest and projected to increase dramatically in coming decades. The field could also benefit from more detailed descriptions of the process and types of cultural adaptations to interventions.
Project-Based Guided Inquiry (PBGI) in Introductory Chemistry

Undergraduate science laboratory courses are a powerful supplement to their corresponding lecture courses and can improve student learning. This is particularly true for introductory science courses. While the lectures provide students with a broad introduction to theory and history, the laboratory provides students with hands-on experience, opportunities to witness scientific principles firsthand, and, at its best, direct engagement with inquiry and the processes of science. Based on the science education literature, principles of backward design, and evidence-based practices, we have developed a project-based guided inquiry (PBGI) curriculum for students in the introductory chemistry laboratory. In the PBGI approach, students “solve a real-world problem over time through the systematic analysis of data and are given guiding questions to support the development of investigations to answer the problem” (Wheeler LB, Maeng JL, Chiu JL, Bell RL, J Res Sci Teach 54:463–492, 2017b). Essential to the PBGI curriculum are a team-based approach to engaging in inquiry and support mechanisms to ensure success of diverse students. Our research demonstrates the efficacy of the PBGI curriculum in improving students’ content knowledge, confidence, and skills. In this chapter, we describe our PBGI approach, detail the essential components of the PBGI curriculum, and describe research demonstrating the efficacy of our approach. We conclude with a section exploring different ways to modify the curriculum for different contexts.
A Tale of Two Cultures

I was born in 1944 in St. Albans, New York, and schooled in the boldly democratic belief in civil rights and racial equality. At times, however, it was hard to shrug off the shadow of inferiority that showed up where and when it was least expected. Eventually, my family left St. Albans for San Juan, Puerto Rico, a small island in the Caribbean. Despite the journalism prizes I had earned as a journalist for the San Juan Star and the acceptance achieved among prominent leaders of Puerto Rican society, in the late 1980s I was still vulnerable to prejudice by virtue of my skin color and being female. To this day, not many visibly black individuals, male or female, hold public positions of power. Many black people in Puerto Rico remain in the background or are invisible.
Heterotrimeric G Proteins

Heterotrimeric G proteins are cytosolic, membrane-associated proteins that transduce neuromodulatory signals within autonomic, sensory, and central nervous system neurons. Activated by G protein-coupled receptors embedded in the pre- and postsynaptic membranes of neurons, G proteins control the activities of ion channels and enzymes that generate intracellular second messenger molecules. The G α and G βγ components of heterotrimeric G proteins have both independent and tightly coordinated roles in the regulation of these effectors. G protein activation is controlled by G protein-coupled receptors and GTPase-activating proteins that respectively stimulate guanosine triphosphate binding and hydrolysis by Gα.
The Legendary Biographies of Tamerlane: Islam and Heroic Apocrypha in Central Asia

Timur (or Tamerlane) is famous as the fourteenth-century conqueror of much of Central Eurasia and the founder of the Timurid dynasty. His reputation lived on in his native lands and reappeared some three centuries after his death in the form of fictional biographies, authored anonymously in Persian and Turkic. These biographies have become part of popular culture. Despite a direct continuity in their production from the eighteenth century to the present, they remain virtually unknown to people outside the region. This remarkable and rigorous scholarly appraisal of the legendary biographies of Tamerlane is the first of its kind in any language. The book sheds light not only on the character of Tamerlane and how he was remembered and championed by many generations after his demise, but also on the era in which the biographies were written and how they were conceived and received by the local populace during an age of crisis in their own history.
Introduction to Biological Responses to Materials

Abstract Systemic and tissue-level responses to biomaterials and medical devices are largely driven by biomaterial–tissue interactions in the local environment where they are implanted. Particularly for devices that are not retrieved and are meant to be “permanently” implanted, their ability to function and alleviate the condition for which they were implanted is dependent on minimizing or quickly resolving undesirable interactions with host tissue. Key concepts and systems that mediate these host responses are described in the following chapters.
Promotion: An Intractable Management Problem for Academic and Public Libraries

The lack of opportunities for promotion within libraries may be an important reason for job dissatisfaction and lowered morale. This column examines reasons why librarians wish to be promoted, the ...
Design of sustainable lip gloss formulation with biosurfactants and silica particles.

Objective The main objective of this study was to design a sustainable lip gloss from water-in-oil emulsions by understanding the rheology of combining biosurfactants (rhamnolipids and sophorolipids) with silica particles (Aerosil powders). The different parameters consisted of the silica particle diameter size, the concentration of the particles within the formulation, alongside the different types of biosurfactant and oils used. The experimental results could provide information on the formulation design of cosmetic emulsions such as lip products and foundations. Methods One parameter was varied each time, while the rest were kept constant in order to determine their effect on the viscosity profile of the formulations. A traditional mechanical rheometer was used in order to measure the bulk viscosity profiles of the different formulations, over a wide range of shear stress applied. Results The larger silica particle diameter size indicated an increase in the viscosity of the formulations, as yield stress was also generated for the specific diameter of 14 nm. It was also found that as the particle concentration increased, the viscosity increased as well. Rhamnolipids and sophorolipids indicated very similar behaviour, meaning that the biosurfactant acts as an emulsifier and does not impact the system's rheological behaviour. The replacement of silicone oil with other natural oils was only successful with canola, and castor oil, since jojoba, squalene and mineral oil were not stabilized. Conclusion The lip gloss was designed by water-in-oil emulsions which were stabilized by biosurfactants and the rheology of the oil phase was enhanced by silica particles. The formulation rheology gave a stable emulsion, the shear-thinning effect ensured easy applicability, whereas the viscosity and elasticity provided nice hold on the lips.
Radiometric Autonomous Navigation Fused with Optical for Deep Space Exploration

With the advent of the Deep Space Atomic Clock, operationally accurate and reliable one-way radiometric data sent from a radio beacon (i.e., a DSN antenna or other spacecraft) and collected using a spacecraft’s radio receiver enables the development and use of autonomous radio navigation. This work examines the fusion of radiometric data with optical data (i.e. OpNav) to yield robust and accurate trajectory solutions that include selected model reductions and computationally efficient navigation algorithms that can be readily adopted for onboard, autonomous navigation. The methodology is characterized using a representative high-fidelity simulation of deep space cruise, approach, and delivery to Mars. The results show that the combination of the two data types yields solutions that are almost an order of magnitude more accurate than those obtained using each data type by itself. Furthermore, the combined data solutions readily meet representative entry navigation requirements (in this case at Mars).
Characteristics and outcomes of small abdominal aortic aneurysm rupture in the American College of Surgeons National Surgical Quality Improvement Program database.

Abstract Objective The current guidelines recommend elective abdominal aortic aneurysm (AAA) repair at 5.5 cm for men and 5.0 cm for women. However, rupture can occur in patients with an aneurysm smaller than these size thresholds. In the present study, we investigated the proportion of AAAs that rupture at sizes less than elective operative thresholds and compared the outcomes of repair with those of aneurysms that had ruptured at a larger size. Our hypothesis was that the rupture of small AAAs carries mortality similar to that of rupture at larger sizes. Methods The American College of Surgeons National Surgical Quality Improvement Program targeted vascular files for open AAA repair and endovascular aneurysm repair (EVAR) were reviewed for all cases of ruptured AAAs (rAAAs) from 2011 to 2018. The patients were divided into two groups: those with small AAAs that had ruptured at a size less than the current size guidelines for elective repair and those with large AAAs that had ruptured at a size that had met the criteria for elective repair. Univariate analyses were conducted to compare the comorbidities and perioperative outcomes of infrarenal rAAA repair between the groups. Multivariable logistic regression was performed to examine the differences in mortality between small and large rAAAs after controlling for confounding variables. Results Of the 1612 rAAA repairs, 167 (10.4%) were small rAAAs. The proportion of small rAAAs did not significantly change during the study period (P = .15). The large rAAA group was more likely to have juxtarenal or suprarenal aneurysms compared with the small rAAA group (27% vs 16%; P = .001). A comparison of infrarenal rAAAs only demonstrated that the mean small rAAA (n = 141) diameter was 4.1 cm in the women and 4.5 cm in the men compared with the large rAAAs (n = 1051), with a mean diameter of 7.1 cm in women and 8.3 cm in men (P Conclusions Of all AAA repairs classified as treating rupture, 10% were for patients with small AAAs. Patients with small rAAA were less likely to present with hypotension and were more likely to have undergone EVAR. Further research into sac morphology and more sensitive imaging modalities might help identify small rAAAs at high risk of rupture that would benefit from elective repair.
Sweet syndrome with bitter outcomes in cervical cancer: A case report

Abstract Background Sweet Syndrome, or acute febrile neutrophilic dermatosis, is a non-infectious, painful rash accompanied by fever, leukocytosis and skin biopsy showing neutrophilic dermal inflammation. It is either idiopathic, drug-induced or malignancy associated (MASS). MASS is uncommon in cervical cancer, and usually signals diagnosis, progression or recurrence. Clinical Course Two months following chemoradiation for stage IIIC2(r) squamous cell carcinoma (SCC) of the cervix, a 55-year-old female developed painful papules and plaques on her left toes. One week later she developed fever and the rash spread to her body. Labs revealed leukopenia and an elevated erythrocyte sedimentation rate. Punch biopsy showed neutrophilic dermal inflammation with papillary dermal edema and was negative for infectious immunohistochemistry. The clinical presentation and histopathological features were consistent with, and met diagnostic criteria for Sweet Syndrome. One month following Sweet Syndrome diagnosis and four months following chemoradiation, positron emission tomography scan revealed recurrence in the pelvic lymph nodes. At this time, she had residual rash on her thighs that responded to oral methylprednisolone. She declined further chemotherapy for recurrent SCC and opted for palliative care. Conclusion We present a rare case of MASS in cervical cancer associated with recurrence two months after chemoradiation.
Incorporating Minimum Variances into Weighted Optimality Criteria

Weighted optimality criteria allow an experimenter to express hierarchical interest across estimable functions through a concise weighting system. We show how such criteria can be implicitly influe...
Selecting Informative Contexts Improves Language Model Fine-tuning

Language model fine-tuning is essential for modern natural language processing, but is computationally expensive and time-consuming. Further, the effectiveness of fine-tuning is limited by the inclusion of training examples that negatively affect performance. Here we present a general fine-tuning method that we call information gain filtration for improving the overall training efficiency and final performance of language model fine-tuning. We define the information gain of an example as the improvement on a validation metric after training on that example. A secondary learner is then trained to approximate this quantity. During fine-tuning, this learner selects informative examples and skips uninformative ones. We show that our method has consistent improvement across datasets, fine-tuning tasks, and language model architectures. For example, we achieve a median perplexity of 54.0 on a books dataset compared to 57.3 for standard fine-tuning. We present statistical evidence that offers insight into the improvements of our method over standard fine-tuning. The generality of our method leads us to propose a new paradigm for language model fine-tuning — we encourage researchers to release pretrained secondary learners on common corpora to promote efficient and effective fine-tuning, thereby improving the performance and reducing the overall energy footprint of language model fine-tuning.
The Predator’s Purpose: Intention Perception in Simulated Agent Environments

We evaluate the benefits of intention perception, the ability of an agent to perceive the intentions and plans of others, in improving a software agent’s survival likelihood in a simulated virtual environment. To model intention perception, we set up a multi-agent predator and prey model, where the prey agents search for food and the predator agents seek to eat the prey. We then analyze the difference in average survival rates between prey with intention perception—knowledge of which predators are targeting them—and those without. We find that intention perception provides significant survival advantages in almost all cases tested, agreeing with other recent studies investigating intention perception in adversarial situations and environmental danger assessment.
An On-Chip Amplitude and Frequency Modulating Graphene-based Plasmonic Terahertz Signal Nano-Generator

An on-chip modulator-integrated graphene-based plasmonic nanogenerator that operates in the terahertz band is presented. The device is based on a gated High Electron Mobility Transistor (HEMT). The use of graphene as the 2-Dimensional Electron Gas (2DEG) channel allows room temperature operation of large plasmonic oscillations which are highly tunable over a broad frequency range (1 to 2 THz). By implementing asymmetric boundary conditions at the source and drain, known as the Dyakonov-Shur (DS) instability, accelerated electrons excite plasmonic waves which reflect at the drain side of the channel. This induces Surface Plasmon Polariton (SPP) waves on the gate, which results in electromagnetic radiation in the THz region. By dynamically tuning these boundary conditions, the device operates with an integrated modulator. The device is numerically modeled and analyzed using an in-house developed multi-physics finite-difference platform based on the Hydrodynamic Model (HDM) for ballistic transport and Maxwell's equations for calculating the electromagnetic fields. After steady state is reached, the numerical analysis shows a clean waveform is possible with amplitude and frequency modulation capabilities. This device offers for the first time and in a compact form factor integrated generation, modulation and radiation functionalities.
Two Party Dynamics

The purpose of this chapter is to examine the dynamics of an idealized two party democracy. In this setting, we will investigate the behavior of two political parties who must compete for support from a common population. This is the first case where the dynamics of democracy are analyzed mathematically. In an idealized setting, what are the conditions under which two party democracy leads to an equilibrium, and in what kinds of situations does the presence of two party democracy lead to the transformation of the democratic competition?
Cognitive and Knowledge-Based Influences on Social Representations

Publisher Summary This chapter explains the cognitive and knowledge-based influences on social representations. The chapter presents a general framework for understanding the nature of developmental changes associated with social representational processes in adulthood. This framework identifies at least two sets of influences on such processes that are affected by aging and highlights their independent as well as interactive effects. Research presents that aging is associated with constraints on impression formation through normative changes in cognitive skills. The changes affect the efficiency of operations and the resources available for processing social information. At the same time, changes in goals and belief systems influence the characteristics of other people to which the individual attend and the nature of processing in which individual engage. It is also important to consider the extent to which cognitive factors influence goals. The research explains that aging-related declines in cognitive functioning might limit the ability of individuals to process social information in a manner consistent with situational goals. At the same time, it is clear that the focus on younger adults limits the understanding of the mechanisms underlying social information processing. Finally benefits can be obtained in understanding other aspects of social cognitive functioning when age is included as a variable in research.
Psychological Factors in Childhood Illness

The last several decades in pediatric medicine have been characterized by a number of major strides in health care and a dramatic decline in the incidence of childhood illness and mortality. Along with medical advances, demands have been placed on pediatricians to address the psychological aspects of children, particularly as they relate to illness. As a result, pediatric psychology has emerged as a rapidly expanding specialty area that attempts to merge the concerns of both clinical psychology and pediatric medicine into a more holistic approach to health care (Routh, 1975). The dramatic growth of the field during its 13-year history indicates that pediatric psychology has served a useful purpose in both medicine and clinical psychology. The present chapter attempts to present an overview of the current status of research in pediatric psychology. A brief examination of theoretical models of the psychology of illness is presented. In addition, a discussion of the factors that influence the child’s response to illness is accompanied by a consideration of the impact of illness on the lives of children and their families. Finally, a separate section describes a group of common childhood disorders and presents research on their associated psychological components. Hopefully, the reader will come to more fully understand and appreciate the complex relationship between the medical and the behavioral factors that are present in the chronically ill child.
Web-Based virtual learning environments: a research framekwork and a preliminary assessment of effectiveness in basic IT skills training

Internet technologies are having a significant impact on the learning industry. For-profit organizations and traditional institutions of higher education have developed and are using web-based courses, but little is known about their effectiveness compared to traditional classroom education. Our work focuses on the effectiveness of a web-based virtual learning environment (VLE) in the context of basic information technology skills training. This article provides three main contributions. First, it introduces and defines the concept of VLE, discussing how a VLE differs from the traditional classroom and differentiating it from the related, but narrower, concept of computer aided instruction (CAI). Second, it presents a framework of VLE effectiveness, grounded in the technology-mediated learning literature, which frames the VLE research domain, and addresses the relationship between the main constructs. Finally, it focuses on one essential VLE design variable, learner control, and compares a web-based VLE to a traditional classroom through a longitudinal experimental design. Our results indicate that, in the context of IT basic skills training in undergraduate education, there are no significant differences in performance between students enrolled in the two environments. However, the VLE leads to higher reported computer self-efficacy, while participants report being less satisfied with the learning process.
Effect of injury severity on lower urinary tract function after experimental spinal cord injury

Abstract Lower urinary tract dysfunction is a serious burden for patients following spinal cord injury. Patients are usually limited to treatment with urinary drainage catheters, which can lead to repeated urinary tract infections and lower quality of life. Most of the information previously obtained regarding lower urinary tract function after spinal cord injury has been in completely transected animals. After thoracic transection in the rat, plasticity of local lumbosacral spinal circuitry establishes a “reflex bladder,” which results in partial recovery of micturition, albeit with reduced voiding efficiency. Since at least half of cord-injured patients exhibit neurologically incomplete injury, rat models of clinically relevant incomplete contusion injury have been developed. With respect to lower urinary tract function, recent anatomical and physiological studies have been performed after incomplete thoracic contusion injury. The results show greater recovery of lower urinary tract function that varies inversely with the severity of the initial trauma and is positively correlated with time after injury. Recovery, as measured by coordination of the bladder with the external urethral sphincter, occurs between 1 and 4 weeks after spinal cord injury. It is associated with normalization of: serotonin immunoreactivity and glutamate receptor subunit mRNA expression in the dorsolateral nucleus that innervates the external urethral sphincter muscle, the response to glutamatergic pharmacological probes administered at the lumbosacral spinal cord level, and c-Fos activation patterns in the lumbar spinal cord. Understanding the mechanisms involved in this recovery will provide a basis for enhancing lower urinary tract function in patients after incomplete spinal cord injury.
High frequency EEG activity associated with ictal events in an animal model of infantile spasms.

Summary Purpose: To describe high frequency (HF) electrographic activity accompanying ictal discharges in the tetrodotoxin (TTX) model of infantile spasms. Previous studies of HF oscillations in humans and animals suggest that they arise at sites of seizure onset. We compared HF oscillations at several cortical sites to determine regional differences. Methods: TTX was infused for 4 weeks into the neocortex of rats beginning on postnatal days 11 or 12. Electroencephalography (EEG) electrodes were implanted 2 weeks later and video-EEG recordings were analyzed between postnatal days 31 and 47. EEG recordings were digitally sampled at 2,048 Hz. HF EEG activity (20–900 Hz) was quantified using compressed spectral arrays and band-pass filtering. Key Findings: Multiple seizures were analyzed in 10 rats. Ictal onset was associated with multiple bands of rhythmic HF activity that could extend to 700 Hz. The earliest and most intense discharging typically occurred contralaterally to where TTX was infused. HF activity continued to occur throughout the seizure (even during the electrodecrement that is recorded with more traditional filter settings), although there was a gradual decrease of the intensity of the highest frequency components as the amplitude of lower frequency oscillations increased. Higher frequencies sometimes reappeared in association with spike/sharp-waves at seizure termination. Significance: The findings show that HF EEG activity accompanies ictal events in the TTX model. Results also suggest that the seizures in this model do not originate from the TTX infusion site. Instead HF discharges are usually most intense and occur earliest contralaterally, suggesting that these homologous regions may be involved in seizure generation.
Elimination of the "Birds Beak" in trench MOS-gate power semiconductor devices

In the conventional fabrication process of trench MOS-gate power devices, the isolation of polysilicon gate from the source metal is achieved by the local oxidation of polysilicon within the refilled trenches. This isolation scheme results in the formation of "Birds Beak" due to the unwanted oxidation of the silicon at the corners near mouth of the trenches. The formation of the birds beak imposes many critical design constraints on the fabrication of trench MOS-gate power devices. Fabrication process steps required to eliminate the birds beak and overcome these constraints are described in this paper. Trench MOS-gate power devices fabricated using the birds beak "free" gate isolation process have the highest channel density. The elimination of the birds beak also simplifies the fabrication of all the self-aligned and triple diffused trench MOS-gate power devices.
Political Externalities, Nondiscrimination, and a Multilateral World (Second Version)

During the past half century tariffs have reached historically low levels through gradual, nondiscriminatory, and multilateral liberalization featuring reciprocal concessions. Yet economists have not obtained convincing explanations of why liberalization possesses these characteristics or of what their implications are. There is an extensive theoretical literature on multilateral trade agreements, based on the idea of terms-of-trade externalities between national governments, but this literature is inconsistent with actual agreements. This paper presents an alternative, rudimentary, multi-country model with high initial tariff barriers; a caricature of the world of half a century ago; based instead on political externalities between governments. With remarkably little necessary formal structure in particular, no formal bargaining model the framework gives an immediate and transparent role to gradual liberalization, reciprocity, nondiscrimination, and multilateral negotiation that is consistent with and closely parallels actual experience.
Findings in an independent sample support an association between bipolar affective disorder and the G72/G30 locus on chromosome 13q33

Findings in an independent sample support an association between bipolar affective disorder and the G72/G30 locus on chromosome 13q33
Factors Affecting the Apparent Radiocarbon Age of Textiles: A Comment on “Effects of Fires and Biofractionation of Carbon Isotopes on Results of Radiocarbon Dating of Old Textiles: The Shroud of Turin”, by D. A. Kouznetsovet al.

Cet article est une reponse a un papier publie dans ce numero de JOURNAL OF ARCHAEOLOGICAL SCIENCE (Vol. 23, N°1, pp.109-121, Janvier 1996) concernant les effets du feu sur la cellulose des tissus et leur impact sur la datation par radiocarbone de ces memes tissus en general, et du Suaire de Turin en particulier
A Variational-Asymptotic Theory of Smart Slender Structures

The goal of the present work is to develop an efficient simulation tool with high-fidelity to help the engineers design and analyze smart slender structures with embedded piezoelectric materials. Actuation and sensing capabilities of piezoelectric material embedded in smart beam including geometric nonlinearity will be explored. The dimensional reduction process has been carried out using the powerful Variational Asymptotic Method. Starting from the exact three-dimensional electric-mechanically coupled enthalpy functional, the asymptotical analysis is done on the functional itself with respect to the naturally occurring small parameters. The original three-dimensional electric-mechanical problem of the slender structure is decomposed into two separate problems: a two-dimensional analysis over the cross section and a one-dimensional analysis over the beam reference line. The coupled cross-sectional analysis is being implemented in VABS, a versatile cross-sectional analysis code.Copyright © 2005 by ASME
Microhardness, indentation toughness, elasticity, plasticity, and brittleness of Ge–Sb–Se chalcogenide glasses

Abstract Elastic/plastic properties of Ge–Se binary and Ge–Sb–Se ternary chalcogenide glasses were explored by indenting with Vickers and Brinell (spherical) microindenters using static and ‘instrumented’ (load versus penetration) recording machines and analyzed further using a non-contact profilometer. The load-dependence of microhardness, indentation fracture toughness and brittleness versus the average covalent coordination number, 〈r〉, were studied. It is concluded that the elastic recovery of deformations is maximized at ∼GeSe4 (〈r〉 = 2.4), which is consistent with ‘optimized connectivity’ of the rigidity percolation arguments. Surprisingly, many of the extrema were nearly non-existent in the ternary glasses.
Amplitude Vacillation on an f-Plane

Abstract Amplitude vacillation is studied using a spectral version of the two-level quasi-geostrophic model in a β-plane channel. The parameters are chosen so that only a single wave may be unstable to the undisturbed basic state. It is shown that the weakly nonlinear theories which have been proposed do not work well on the β-plane, because nonlinear interactions are not negligible even though only a single wave has any significant amplitude. The energetics and mechanism of amplitude vacillation on a β-plane are discussed for a case with moderate dissipation and contrasted with the mechanism on an f-plane.
Uniformity amid diversity in RNase P

The ribonucleoprotein RNase P, which catalyzes the Mg2+-dependent removal of the 5′ leader sequence in all precursor tRNAs (ptRNAs), is remarkable for the diversity in its subunit composition (Fig. 1 A). Although all RNase P holoenzymes have an essential RNA subunit, the number of protein subunits varies from 1 in Bacteria to at least 4 in Archaea and 9–10 in Eukarya (1–5). The finding that the bacterial RNase P RNA (RPR) subunit alone is catalytic under in vitro conditions of high ionic strength provided one of the first examples of a true cellular RNA enzyme (6). Despite a shared ancestry, as reflected by sequence/structure similarities especially in regions expected to comprise the catalytic core (Fig. 1 B–E), to date, only some archaeal RPRs were proven to be weakly catalytic, whereas all eukaryal RPRs examined were inactive in the absence of their cognate RNase P proteins (Rpps; refs. 1, 3, 7, and 8). Consistent with the RNA world hypothesis, these findings suggest that the primordial ribozyme activity observed in bacterial RPRs was somehow lost in many archaeal and all eukaryal RPRs with concomitant gains by their cognate Rpps that might have usurped the RPR's catalytic roles. However, such a postulate can now be laid to rest because in this issue of PNAS, Kikovska et al. (9) provide evidence that human RPR can catalyze processing of four different ptRNAs and a model substrate, albeit at rates much lower than that of bacterial RPR.
First order Markov chain approximation of microgrid renewable generators covariance matrix

Smart grids present interesting challenges as we integrate renewable energy sources and allow for customer participation in the decision making. A key to smart grids is getting information from the grid in real time and especially at the distribution level beyond the substation, which we refer to as the microgrid. This paper presents a distributed state estimation algorithm for microgrids with distributed renewable energy generation. We use a factor graph approach to model the microgrid network with renewable generators. The renewable generators are correlated resulting in many loops in the factor graph. This presents a problem when using distributed algorithms such as belief propagation. To limit the number of loops in the factor graph, we approximate the correlation among the renewable generators using a Markov chain approach. The algorithm is sub-optimal, but has low complexity using a greedy approach and Cholesky factorization. We present a simple microgrid example with renewable generators and show through simulations that our approximate solution gives performance close to the optimal solution.
Expulsion Testing of an Anterior Cervical Intervertebral Fusion Cage: Factors Affecting Pull Out Resistance

Factors affecting the expulsion resistance of an anterior cervical discectomy and fusion (ACDF) device in a cadaver model were investigated. Two specimen specific properties were considered; bone mineral density (BMD), and donor age. Also, two surgical procedures were used, representing two different degrees of destabilization of the intervertebral joint. Expulsion forces averaged 176 N (S.D. 60 N) for all specimens. No statistically significant difference in expulsion force was found between the specimens in the two surgical groups. However, expulsion force showed significant correlation to both BMD and donor age, with correlation coefficients of 0.81 and −0.83 respectively.Copyright © 2002 by ASME
Model invariant method for extracting single-channel mean open and closed times from heterogeneous multichannel records.

Abstract We present a proof that the mean open (and closed) times of the individual channels in a multichannel record can be found in a model-independent fashion. As the results are model independent, they can be derived by assuming the simplest model for all the channels, namely that they all have the basic CLOSED OPEN scheme. In particular, the method can be applied to patches where the channel population is heterogenous with respect to open probability. Multichannel simulations are performed to test the limits of applicability of this method to restricted amounts of data. One conclusion is that increasing the number of channels does not substantially reduce the errors in estimating the mean times, in spite of the ‘increased information’ present. We also prove the general applicability of the algorithm of Fenwick et al. (1982) in estimating the mean times without knowledge of the number of channels present. and discuss its limitations. An illustration using experimental data is also given.
Standing out from the crowd

This study explores Caucus, a research methodology specifically designed to elicit the key brand associations that drive product differentiation and brand positioning in product categories characterized by many competitor brands--each having a relatively low market share. It begins with an overview of this methodology, contrasting it with two existing brand-association elicitation methodologies. Next, a step-by-step procedure is outlined for executing a comprehensive Caucus study. Then, the procedure and findings of an illustrative Caucus study are presented. Finally, the implications of Caucus for future brand-association research are discussed.