cssi/SciSciGPT-SciSciNet huggingface dataset:
A bladder-cooling reflex in the anaesthetised guinea-pig: a model of the positive clinical ice-water test.

Abstract Introduction: In patients with detrusor hyperreflexia, intravesical instillation of ice-cold water results in the development of involuntary bladder contractions at volumes less than normal cystometric capacity. This is referred to as a positive ice-water test (+IWT) and can be reversed by vanilloid receptor agonists and potentiated by menthol. The present study was designed to investigate the existence of an analogous cooling reflex in the guinea-pig bladder that could be used as a small animal model in order to test the effects of drugs on the reflex. Methods: Bladder pressure and external urethral sphincter electromyogram (EUS EMG) were recorded in α-chloralose/urethane anaesthetised guinea-pigs during rapid infusion of cold or warm saline into the bladder with or without prior intravesical exposure to menthol or resiniferatoxin (RTX). Results: The mean control micturition threshold volume (TV) of 2.58 ml at 38 °C was reduced to 1.52 ml in response to saline infusion at 3 °C ( P = 0.001). The cold-induced reduction in TV was reproducible during several subsequent repeat infusions at 38 °C and 3 °C and was accompanied by decreases in bladder voiding pressure. The duration of the micturition reflex was markedly increased following cold compared with warm saline infusion (mean 24.5 s at 3 °C, 10.2 s at 38 °C, P = 0.001) and was associated with oscillations in bladder pressure and concomitant bursting activity in the EUS EMG. During step-wise decreases in infusate temperature from 38 °C to 23 °C, 15 °C, 7 °C and 3 °C, the threshold infusate temperature to elicit a significant reduction in TV was 15 °C. The reduction in TV at 3 °C was potentiated by intravesical infusion of 0.6 mM menthol whilst intravesical infusion of 500 nM RTX reversed the reduction in TV at 3 °C. Discussion: These data suggest that a bladder-cooling reflex is present in the anaesthetised guinea-pig and represents a useful small animal model of the clinical +IWT.
Improved pulse shaping to achieve constant strain rate and stress equilibrium in split-hopkinson pressure bar testing

Assuring a constant strain rate during dynamic testing is highly desirable to support the development of physically based predictive, constitutive material models. Many dynamic tests conducted on high-work-hardening materials, or materials that do not display a classic power-law-type hardening behavior, such as materials exhibiting complex sigmoidal concave-upward hardening (shape-memory alloys or a number of textured hexagonal metals due to deformation twinning), often result in continuously decreasing strain rates as a function of strain throughout the test. Incident pulse shaping has not been fully developed or successfully demonstrated over a large range of strain in high work hardening or complex-hardening materials. To shape an incident pulse for a constant strain rate in a split-Hopkinson pressure bar (SHPB) test, a high-strength, high-work-hardening rate (HSHWHR) material was selected to fabricate the pulse shaper. Several test sample materials, namely, 50-50 NiTi superelastic alloy, higher strength 60NiTi alloy, tungsten single crystals, interstitial-free (IF) steel, and MACOR (a glassy ceramic), which display a range of strength levels, work-hardening rates, and superelastic hardening behavior in the case of 50-50 NiTi, were tested in the SHPB with and without a pulse shaper at different temperatures and strain rates. The current experiments demonstrate that HSHWHR pulse-shaper materials are ideally suited to shape the incident pulse to achieve constant strain rates and achieve stress state equilibrium, while inherently dampening high frequency oscillations in the incident pulse.
A test of situational engineering for training leaders.

A leadership development program was conducted with a sample of 96 leaders to investigate the contributions of the Contingency Model's assumptions in determining leadership effectiveness. Subjects ...
Guest editorial: Professor Albert H. Rubenstein — A legend in his own time

AL RUBENSTEIN has achieved something that very few people do. He has become a legend in his own time … legend as an educator, legend as a researcher, and legend as the editor of this TRANSACTIONS for quarter of a century. This is the last issue under his editorship but his impact on the emerging engineering management discipline has been so great that he will always remain as one of the leaders in the field, and will always be a part of this TRANSACTIONS. I am pleased, in fact, that he has agreed to stay on the Editorial Board as Editor Emeritus.
Visualization of Early Stage Damage Propagation During Hypervelocity Impacts on Brittle Materials

Abstract The final outcome of an impact event (crater size, penetration depth) can be affected greatly by damage accumulation at early stages of the impact event when non-tensile stress states dominate. We have conducted hypervelocity impact experiments on bonded basalt/pyrex specimens utilizing high speed imaging to investigate the damage evolution at times before waves reflect from the lateral specimen boundaries. Results show that significant damage accumulates before the arrival of tensile release waves often associated with failure of brittle materials. Initially, a diffuse damage front propagates into the specimen at a speed close to the shear wave speed. As this damage front slows spatial instabilities appear along the damage front, which develop into localized damage zones.
Impact of work on early-recovery Alcoholics Anonymous affiliation.

ABSTRACT The impact of work on Alcoholics Anonymous (A. A.) affiliation has not been studied despite the fact that work experiences and workplace dynamics may influence problem drinkers' participation in post-treatment recovery programs such as A.A. This exploratory study recruited individuals (N = 55) from inpatient and intensive outpatient treatment for alcohol problems and assessed their A.A. involvement approximately three months after discharge. An expanded measure of affiliation is used, including participation in a range of A.A. practices and acceptance of major A.A. tenets. Questionnaire and interview data were gathered on employment status, alcohol-related job problems, job stability, perceived workplace support, attitudes toward work, severity of drinking-related problems, health, mental health, relationship factors, and demographics. The degree to which subjects generally perceived that they had a serious drinking problem (“hit bottom”) was associated with affiliation, but alcohol-related job p...
Article Commentary: Social Constructivism, Positivism, and Facilitated Communication:

Facilitated communication, a technique that is said to enhance the communicative abilities of individuals with severe language impairments, has engendered much controversy. Biklen and Duchan (1994)...
The partitioned element method in computational solid mechanics

Abstract A finite-element-like approximation method is proposed for solid-mechanics applications, in which the elements can take essentially arbitrary polygonal form. A distinguishing feature of the method, herein called the “partitioned element method,” is a partitioning of the elements into quadrature cells, over which the shape functions are taken to be piecewise linear. The gradient and constant values for each cell are determined by minimizing a quadratic function which represents a combined smoothness and compatibility measure. Linear completeness of the shape-function formulation is proved. Robustness in the presence of element non-convexity and geometric degeneracy (e.g. nearly coincident nodes) are particular goals of the method. Convergence for various 2D linear elasticity problems is demonstrated, and results for a finite-deformation elastic–plastic problem are compared to those of the standard FEM.
Current status of midinfrared quantum and interband cascade lasers for clinical breath analysis

State-of-the-art quantum- and interband-cascade-based chemical sensors may be effective new tools for the identification and quantification of trace gases in human breath for clinical uses. Increased or decreased concentrations of these molecules are associated with the pathogenesis of a large number of diseases. Current technologies enable breath analyses to be performed on a single breath and the results are available in real time. Critical parameters including sensor sensitivity, selectivity, real-time monitoring capability, robustness, cost, size, and weight determine the progress made toward the development and availability of commercial diagnostic material.
Treatment with the antiepileptic drugs phenytoin and gabapentin ameliorates seizure and paralysis of Drosophila bang-sensitive mutants.

Drosophila bang-sensitive (bs) mutants exhibit a stereotypic seizure and paralysis following exposure to mechanical shock. In a physiological preparation, seizures and failures corresponding to the defective behavior are observed in response to high frequency stimulation. The amplitude of the stimulus necessary to produce bs behavior, or seizure threshold, varies with bs mutant and its gene dosage. In many respects, the bs defects are similar to those observed in mammalian seizure disorders. Antiepileptic drugs (AEDs) were administered by feeding to easily shocked2 (eas2), a representative bs mutant. The mean recovery times of treated flies were examined in comparison to control cultures. Some of the drugs administered, including carbamazeprine, ethosuximide, and vigabactrin, had little or no effect on the bs behavior of eas2. Gabapentin, however, showed a reduction in mean recovery time with chronic drug exposure. Phenytoin also had a significant effect on the bs behavior of treated flies. There was a reduction of both mean recovery time and the percentage of flies that displayed bang-sensitive behavior with both acute and chronic treatment. The adult giant fiber preparation was used to examine the effects of phenytoin physiologically. Treated eas2 flies showed changes in their response to normal stimulation as well as alterations in seizure threshold in response to high frequency stimulation. Gabapentin was also effective against two other bs mutants, bangsenseless1 and slamdanceiso7.8, at strain-specific concentrations, while phenytoin also reduced bang-sensitive behaviors in bangsenseless1 in a dose dependent manner. AEDs, therefore, can be used to dissect aspects of bs behavior and this model may be useful in understanding the underlying basis of seizure disorders. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 503–513, 2004
CT-guided stereotactic biopsy of intracranial lesions: correlation between core biopsy and aspiration smear.

Computerized tomography (CT)-guided stereotactic biopsies of intracranial lesions in 29 patients were analyzed, paying particular attention to the correlation between core biopsies and aspiration smears. Seven percent were, nondiagnostic due to sampling error. Discrepancies occurred between core biopsies and aspiration smears in 10% of the cases. In two instances of such discrepancies, cytologic findings on the aspiration smear yielded the diagnosis of metastatic tumor. One patient, with herpetic encephalitis, was diagnosed by electron microscopic review of the core biopsy only. One patient died of an intraoperative hemorrhage, a complication of the fine-needle technique. Diagn Cytopathol 1986;2:126-1 32.
Evaluation of the late life disability instrument in the lifestyle interventions and independence for elders pilot (LIFE-P) study

The late life disability instrument (LLDI) was developed to assess limitations in instrumental and management roles using a small and restricted sample. In this paper we examine the measurement properties of the LLDI using data from the Lifestyle Interventions and Independence for Elders Pilot (LIFE-P) study. LIFE-P participants, aged 70-89 years, were at elevated risk of disability. The 424 participants were enrolled at the Cooper Institute, Stanford University, University of Pittsburgh, and Wake Forest University. Physical activity and successful aging health education interventions were compared after 12-months of follow-up. Using factor analysis, we determined whether the LLDI's factor structure was comparable with that reported previously. We further examined how each item related to measured disability using item response theory (IRT). The factor structure for the limitation domain within the LLDI in the LIFE-P study did not corroborate previous findings. However, the factor structure using the abbreviated version was supported. Social and personal role factors were identified. IRT analysis revealed that each item in the social role factor provided a similar level of information, whereas the items in the personal role factor tended to provide different levels of information. Within the context of community-based clinical intervention research in aged populations, an abbreviated version of the LLDI performed better than the full 16-item version. In addition, the personal subscale would benefit from additional research using IRT. The protocol of LIFE-P is consistent with the principles of the Declaration of Helsinki and is registered at http://www.ClinicalTrials.gov (registration # NCT00116194).
Social Movement Tactics, Organizational Change and the Spread of African-American Studies

Social movement research suggests that protest is effective because it de-legitimizes existing policies and imposes costs on power holders. I test this hypothesis with data on African-American student protest and the creation of departments of African-American Studies. I find that non-disruptive protest, such as rallies and demonstrations, has a positive effect on the probability that a university will create a Department of African-American Studies. Disruptive protest, such as sit-ins and vandalism, has no significant effect. I argue that non-disruptive protests are successful because they allow sympathetic administrators to act on behalf of political challengers, while disruptive protests deprive administrators of the legitimacy needed to enact change. I also find limited evidence of intra-university mimicry as a factor in the creation of African-American Studies programs.
Complete nucleotide sequence and characterization of pUA140, a cryptic plasmid from Streptococcus mutans.

Approximately 5% of strains of Streptococcus mutans contain plasmid DNA. Strain UA140 harbors a 5.6-kb cryptic plasmid, pUA140, with an overall G+C content of 32.7%. Five open reading frames (ORF), encoding peptides of larger than 100 amino acid residues, were initially designated as ORF1 to ORF5. These five ORFs were located on the same strand of pUA140. ORF1 (258 amino acids) resembled a replication protein, Rep. Upstream of the putative Rep gene, a double-stranded origin for plasmid replication that showed strong similarity to those of a number of plasmids in the pT181 family was identified. Further upstream was a region constituting the single-stranded origin of replication. A single-stranded DNA intermediate was detected during plasmid replication. Taken together, these results suggest that pUA140 replicated by the rolling circle replication mechanism but exhibited several characteristics that differ from those of other members of the pT181 plasmid family.
Anisotropic hardening equations derived from reverse-bend testing

Abstract The plastic response of materials during reverse loading has practical consequences for common sheet forming operations in terms of loads, localization behavior, and springback. However, it is difficult to measure the reverse loading (Bauschinger effect) in sheet materials because of their propensity to buckle. A simple reverse-bend test was constructed and used to investigate the cyclic loading of three automotive body alloys. The results showed that consideration of the Bauschinger effect is essential to obtaining agreement with such results. An inverse procedure was used to determine anisotropic hardening law parameters. Laws obtained in this way were compared with ones generated by more sensitive tension-compression tests appearing in the literature for the same alloys. The two laws were significantly different, but both produced accurate simulations of reverse-bend test load–displacement curves. Several artificial material models were then constructed to simulate the reverse-bend test and thus to probe its sensitivity to material constitutive equation details. For materials whose reverse-loading response varies with the level of prestrain, as is the case for each of the three alloys tested, a wide range of constitutive response is capable of producing identical reverse-bending behavior. The results show that inverse procedures applied to the reverse-bend test do not provide unique results, and thus the usefulness of the reverse-bend test for such investigations is limited.
Heterogeneous composition of voltage-dependent K(+) currents in hepatic stellate cells.

Purpose Hepatic stellate cells (HSC) are a type of pericyte with varying characteristics according to their location. However, the electrophysiological properties of HSC are not completely understood. Therefore, this study investigated the difference in the voltage-dependent K(+) currents in HSC. Materials and methods The voltage-dependent K(+) currents in rat HSC were evaluated using the whole cell configuration of the patch-clamp technique. Results Four different types of voltage-dependent K(+) currents in HSC were identified based on the outward and inward K(+) currents. Type D had the dominant delayed rectifier K(+) current, and type A had the dominant transient outward K(+) current. Type I had an inwardly rectifying K(+) current, whereas the non-type I did not. TEA (5 mM) and 4-AP (2 mM) suppressed the outward K(+) currents differentially in type D and A. Changing the holding potential from -80 to -40 mV reduced the amplitude of the transient outward K(+) currents in type A. The inwardly rectifying K(+) currents either declined markedly or were sustained in type I during the hyperpolarizing step pulses from -120 to -150 mV. Conclusion There are four different configurations of voltage-dependent K(+) currents expressed in cultured HSC. These results are expected to provide information that will help determine the properties of the K(+) currents in HSC as well as the different type HSC populations.
Designing multiple scan chains for systems-on-chip

We propose a branch-and-bound framework for designing non-reconfigurable multiple scan chains for systems-on-chip to minimize test application time. Multiple scan chain design problem defined in this paper involves (1) partitioning wrapper cells and core internal scan registers into multiple scan chains, and (2) ordering the wrapper cells and the registers in each scan chain. We design multiple scan chains with test application times within a few percentage of the corresponding optimal in practical run-times. We also demonstrate significant improvements in test application times over prior heuristics for designing multiple scan chains.
Noncontact Selective Laser-Assisted Placement of Thinned Semiconductor Dice

New laser-induced forward transfer (LIFT) techniques promise to be a disruptive technology by enabling high-volume placement of ultrathin bare dice. Limitations of current die-attach techniques such as pick-and-place are presented and discussed which inspired the development of this new placement method. The thermo-mechanical selective laser-assisted die transfer (tmSLADT) process is introduced as an application of the unique blistering behavior of a dynamic releasing layer when irradiated by low-energy-focused UV laser pulses. The potential for tmSLADT to be the next generation LIFT technique is demonstrated by the “touchless” transfer of 65-μm-thick silicon tiles between two substrates spaced 195 μm apart. Additionally, the advantages of an enclosed blister actuator mechanism over previously studied ablative and thermal releasing techniques are discussed. Finally, experimental results indicate that this nonoptimized die transfer process compares with, and may exceed, the placement precision of current assembly techniques.
Histopathologic host response to polypropylene‐based surgical mesh materials in a rat abdominal wall defect model

Composite polypropylene-based surgical mesh materials including various synthetic polymers and naturally occurring biomaterials have been developed to ameliorate device-associated inflammatory response and associated reduced compliance of pure polypropylene meshes. This study evaluated the histomorphologic response of three composite polypropylene-based surgical meshes, Revive™, a polycarbonate polyurethane reinforced monofilamentous polypropylene scaffold, Assure™, a polycarbonate polyurethane reinforced monofilamentous polypropylene scaffold with a resorbable anti-adhesion layer of lactide caprolactone copolymer, and Proceed™, a polypropylene mesh modified with oxidized cellulose, in a soft tissue repair model in the rat. The host inflammatory response and neotissue formation were evaluated by semiquantitative histologic scoring including the amount of cellular infiltration, angiogenesis, presence of multinucleate giant cells, fibrous connective tissue formation, and host neo-extracellular matrix deposition for up to 26 weeks. All three composite surgical mesh materials showed good integration with host tissue as indicated by rapid cellular infiltration, abundant neo-vascularization, minimal shrinkage, and the lack of visible mesh degradation. The devices elicited a similar inflammatory response and the presence of a mild foreign body response in spite of the different composition and morphology of these composite mesh materials. © 2011 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2012.
The role of the nervous system in algae-induced gamete release by Mytilus californianus.

Abstract 1. Algae-induced spawning in M. californianus was associated with an increase in dopamine in the visceral ganglia and a decrease in serotonin in the pedal ganglia. 2. Lesioning studies indicate that nervous communication between the pedal and visceral ganglia plays a major role in gamete release.
A new system identification algorithm based on iterative algebraic filtering

A new algorithm for linear system identification is proposed. Unlike most existing system identification algorithms, this approach uses iterative algebraic filtering to enhance the signal in a high-noise environment. The iterative algebraic filtering approach, which is adopted from a recently developed signal enhancement technique, is aimed at recovering the noise-free output signal form the noise-contaminated signal by exploiting the algebraic properties of the ideal data matrix. Numerical examples show that the proposed method behaves much better than some other popular methods, especially in colored noise. >
Finding protocol manipulation attacks

We develop a method to help discover manipulation attacks in protocol implementations. In these attacks, adversaries induce honest nodes to exhibit undesirable behaviors by misrepresenting their intent or network conditions. Our method is based on a novel combination of static analysis with symbolic execution and dynamic analysis with concrete execution. The former finds code paths that are likely vulnerable, and the latter emulates adversarial actions that lead to effective attacks. Our method is precise (i.e., no false positives) and we show that it scales to complex protocol implementations. We apply it to four diverse protocols, including TCP, the 802.11 MAC, ECN, and SCTP, and show that it is able to find all manipulation attacks that have been previously reported for these protocols. We also find a previously unreported attack for SCTP. This attack is a variant of a TCP attack but must be mounted differently in SCTP because of subtle semantic differences between the two protocols.
Commoditization and the Origins of American Silviculture

Forest ecosystems provide a suite of goods and services, including wood products as well as an array of ecosystem services and other non-timber goods and services. Despite an increasing emphasis on managing forests as holistic systems providing a portfolio of goods and services, silvicultural research has focused on maximizing production of commodities, particularly wood products. Although there has been investment in understanding how silviculture affects wildlife habitat, water resources, recreation, and other non-timber objectives, the emphasis has been on understanding these impacts as side-effects of a silviculture predicated on the production of wood. Commoditization theory provides a lens through which to understand the selection pressures that drive this emphasis on wood production. This article briefly reviews the historical role of commoditization in influencing how modern American silviculture has developed and highlights research needed to create silvicultural knowledge useful in managing for ...
Conjugal amyotrophic lateral sclerosis: Report of a young married couple

We report a 38-year-old nurse who developed amyotrophic lateral sclerosis (ALS) beginning in September 1990. In May 1991, her 38-year-old husband developed dysarthria, which progressed to typical ALS. This is the fourth report in the literature of conjugal ALS occurring outside of Guam. Although this event is most likely due to coincidence, exogenous agents should be considered in the etiology of ALS.
Pharmacogenetic analysis of human steroid 5α reductase type II comparison of finasteride and dutasteride

Human steroid 5 alpha-reductase type II is a prostate-specific, membrane-associated enzyme that catalyzes the conversion of testosterone to dihydrotestosterone, the most potent androgen in the prostate gland. Genetic variants of this enzyme have been associated with both the development and the progression of prostate cancer. Both finasteride and dutasteride are competitive inhibitors of the type II steroid 5 alpha-reductase that have been effectively used for the treatment of benign prostatic hyperplasia. Finasteride has also been successfully utilized for prostate cancer chemoprevention. We here investigate 5 alpha-reductase inhibition assays in vitro to measure the effect of incubation time on the apparent inhibition constant (Ki) for both constitutional and somatic (prostate cancer) enzyme variants. Our systematic pharmacogenetic analysis shows that both finasteride and dutasteride are slow, time-dependent inhibitors of steroid 5 alpha-reductase type II, and that the inhibition kinetics depend on the 5 alpha-reductase genotype. We also show that, overall, dutasteride is a more efficient steroid 5 alpha-reductase inhibitor than finasteride. Based on our data, we are able to map areas of the enzyme that are responsible for this time-dependent inhibition for either (or both) enzyme inhibitor(s). This comprehensive pharmacogenetic analysis of steroid 5 alpha-reductase variants unveiled significant pharmacogenetic variation for both finasteride and dutasteride and thus should be taken into account when designing protocols for treatment and/or chemoprevention of prostatic diseases with either one of these 5 alpha-reductase inhibitors since there is considerable pharmacogenetic variation for both drugs.
A 108dB SNR 1.1mW Oversampling Audio DAC with a Three-Level DEM Technique

Previously reported multi-bit oversampling DeltaSigma audio DACs use 2-level (+1, -1) unit elements in either switched-capacitor or current-steering form. This paper presents a low-power audio DAC that uses a 3-level current-steering unit element architecture.
The Practical Difficulties for Early Educators Who Tried to Address Children’s Realities in Their High-Stakes Teaching Context

The field of publicly funded early childhood education continues to evolve into a discipline in which early educators are expected to teach a more culturally and linguistically diverse student population a standardized set of knowledge and skills so that they can meet policymakers’ academic achievement requirements. This creates a range of challenges for early educators who strive to implement instructional practices that attend to children’s developmental, individual, and sociocultural needs. The article addresses this issue through examining the implementation of a professional development course for prekindergarten and kindergarten teachers that asked them to reconceptualize their understandings of their role in the classroom. Examining how their practical conceptions were affected by their participation in this course revealed an eagerness to pursue lines of study with children that addressed issues central to children’s lives. However, transforming this conceptual willingness into practices within th...
Adipose Stem Cells and Adipogenesis

Adipocytes are highly specialized cells that form and store fat in adipose tissue and play a major role in energy homeostasis in vertebrate organisms. Obesity results from an energy surplus and is characterized by an increased storage of lipid and expansion of adipose tissue. Obesity modifies the endocrine and metabolic functions of adipocytes and is a risk factor for many other metabolic diseases, including type II diabetes, cardiovascular ischemic disease, atherosclerosis, and hypertension.
The Fermi level dependence of the optical and magnetic properties of Ga1−xMnxN grown by metal–organic chemical vapour deposition

The suppression of the ferromagnetic behaviour of metal–organic chemical vapour deposition grown Ga1−x Mnx Ne pilayers by silicon co-doping, and the influence of the Fermi level position on and its correlation with the magnetic and optical properties of Ga1−x Mnx Na re reported. Variation in the position of the Fermi level in the GaN bandgap is achieved by using different Mn concentrations and processing conditions as well as by co-doping with silicon to control the background donor concentration. The effect on Mn incorporation on the formation of defect states and impurity induced energy states within the bandgap of GaN was monitored by means of photoluminescence absorption an de mission spectroscopy. A broad absorption detected around 1.5 eV is attributed to the presence of a subband introduced by Mn induced energy states due to temperature independent transition energies and linewidths. The intensity and the linewidth of the absorption band correlate with the Mn concentration. Similarly, the magnitude of the magnetization decreases as the Fermi level approaches the conduction band, as the Fermi energy is increased above the Mn(0/−) acceptor state. Silicon concentrations >10 19 cm −3 caused the complete loss of ferromagnetic behaviour in the epilayer. The absorption band at 1.5 eV is also not observed upon silicon co-doping. The observed spectroscopic data favour a double-exchange-like mechanism rather than an itinerant free carrier mechanism for causing the ferromagnetism. This behaviour significantly differs from the properties reported for widely studied (Ga, In)MnAs.
The role of passive joint stiffness and active knee control in robotic leg swinging: applications to dynamic walking

The field of autonomous walking robots has been dominated by the trajectory-control approach, which rigidly dictates joint angle trajectories at the expense of both energy efficiency and stability, and the passive dynamics approach, which uses no actuators, relying instead on natural mechanical dynamics as the sole source of control. Although the passive dynamics approach is energy efficient, it lacks the ability to modify gait or adapt to disturbances. Recently, minimally actuated walkers, or dynamic walkers, have been developed that use hip or ankle actuators—knees are always passive—to regulate mechanical energy variations through the timely application of joint torque pulses. Despite the improvement minimal actuation has provided, energy efficiency remains below target values and perturbation rejection capability (i.e., stability) remains poor. In this dissertation, we develop and analyze a simplified robotic system to assess biologically inspired methods of improving energy efficiency and stability in dynamic walkers. Our system consists of a planar, dynamically swinging leg with hip and knee actuation. Neurally inspired, nonlinear oscillators provide closed-loop control without overriding the leg's natural dynamics. We first model the passive stiffness of muscles by applying stiffness components to the joints of a hip-actuated swinging leg. We then assess the effect active knee control has on unperturbed and perturbed leg swinging. Our results indicate that passive joint stiffness improves energy efficiency by reducing the actuator work required to counter gravitational torque and by promoting kinetic energy transfer between the shank and thigh. We also found that active knee control (1) is detrimental to unperturbed leg swinging because it negatively affects energy efficiency while producing minimal performance improvement and (2) is beneficial during perturbed swinging because the perturbation rejection improvement outweighs the reduction in energy efficiency. By analyzing the effects of applying passive joint stiffness and active knee control to dynamic walkers, this work helps to bridge the gap between the performance capability of trajectory-control robots and the energy-efficiency of passive dynamic robots.
Distributed Recursive Least-Squares for Consensus-Based In-Network Adaptive Estimation

Recursive least-squares (RLS) schemes are of paramount importance for reducing complexity and memory requirements in estimating stationary signals as well as for tracking nonstationary processes, especially when the state and/or data model are not available and fast convergence rates are at a premium. To this end, a fully distributed (D-) RLS algorithm is developed for use by wireless sensor networks (WSNs) whereby sensors exchange messages with one-hop neighbors to consent on the network-wide estimates adaptively. The WSNs considered here do not necessarily possess a Hamiltonian cycle, while the inter-sensor links are challenged by communication noise. The novel algorithm is obtained after judiciously reformulating the exponentially-weighted least-squares cost into a separable form, which is then optimized via the alternating-direction method of multipliers. If powerful error control codes are utilized and communication noise is not an issue, D-RLS is modified to reduce communication overhead when compared to existing noise-unaware alternatives. Numerical simulations demonstrate that D-RLS can outperform existing approaches in terms of estimation performance and noise resilience, while it has the potential of performing efficient tracking.
Teaching and Learning Argumentative Reading and Writing: A Review of Research

Acquiring argumentative reading and writing practices reflects a key component of recent curricular reforms in schools and universities throughout the United States and the world as well as a major challenge to teachers of reading and writing in K–12 and college writing classrooms. In this review, we consider the contributions of two research perspectives, cognitive and social, that researchers have employed in the study of the teaching and learning of argumentative reading and writing. We address two basic questions: How do these perspectives with their own disciplinary frameworks and logics of inquiry interactively inform how researchers study argumentative reading and writing, and consequently, how have these orientations informed pedagogical knowledge that may support teachers’ understanding of what argumentation is and how it may be taken up in the educational contexts? We analyze relevant conceptual and empirical studies by considering assumptions underlying the cognitive and social disciplinary perspectives, especially in terms of the warrants that those perspectives assume. We also interrogate how these perspectives’ logics of inquiry reveal assumptions about the transfer of learning as supported by instruction and other practices, such as classroom discussion, computer-supported collaborations, and other forms of instructional support. Using empirical studies of the teaching and learning of argumentative reading and writing conducted in grades K–12 and college writing classrooms, we delineate the assumptions that drive the two perspectives and their instructional consequences, arguing that researchers and teachers need an understanding of their assumptions about knowledge and transfer to establish a clear and coherent relationship between theory and practice. We offer a vision for research that integrates the cognitive and social perspectives to argue that the work of literacy research is to reveal cognitive processes and instructional practices that teachers can promote and students can employ for learning how to do argumentative reading and writing.
Mentoring Undergraduate Students in Computational Materials Research

Computation has become an increasingly important tool in materials science. Compared to experimental research, which requires facilities that are often beyond the financial capability of primarily-undergraduate institutions, computation provides a more affordable approach. In the Physics Department at Eastern Illinois University (EIU), students have opportunities to participate in computational materials research. In this paper, I will discuss our approach to involving undergraduate students in this area. Specifically, I will discuss (i) how to prepare undergraduate students for computational research, (ii) how to motivate and recruit students to participate in computational research, and (iii) how to select and design undergraduate projects in computational materials science. Suggestions on how similar approaches can be implemented at other institutions are also given.
The Drosophila maternal-effect gene fs(1)Ya encodes a cell cycle-dependent nuclear envelope component required for embryonic mitosis

The maternal-effect gene fs(1)Ya is specifically required for embryonic mitosis in Drosophila. fs(1)Ya is involved in the initiation of the first embryonic mitosis and may also be necessary for subsequent embryonic mitotic divisions. fs(1)Ya encodes a 91.3 kd hydrophilic protein containing two putative MPF phosphorylation target sites and two potential nuclear localization signals. This protein is synthesized during postoogenic maturation from its maternal RNA and persists throughout embryogenesis. In early embryos, the fs(1)Ya protein is localized to the nuclear envelope from interphase to metaphase. During anaphase and telophase, it is dispersed in the nucleoplasm and cytoplasm, a behavior that is different from that of both the nuclear envelope and lamins. These results suggest that the fs(1)Ya protein is a cell cycle-dependent component of the nuclear envelope that specifically functions in embryonic mitosis.
Bringing Commodity Chain Analysis Back to Its World-Systems Roots: Rediscovering Womens Work and Households

Globally between 1980 and 2000, women's economic activity rate expanded, narrowing the gender gap in labor force participation. Thus, females now account for one-third or more of the "officially-counted" personnel of export industries (UNICEF 2007), and export agriculture is now feminized (Deere 2005). Today women account for one-third of the manufacturing labor force in developing countries, and females hold more than one-half of the industrial jobs in Asia (Barrientos, Kabeer and Hossain 2004). In much of the global South, females account for a majority of the waged labor force in export agriculture, and they are more heavily concentrated than men in service jobs that provision the supply chains of global production. As a reflection of fewer opportunities for males, women are now less likely to withdraw from the labor force during their childbearing years. In addition, females account for a majority of the income earners in the informal sectors of a majority of global South countries, generate a significant proportion of global commodities through subcontracted work they complete in their households, and provide most of the unpaid family labor needed to support household-based farms and businesses that are dominated by males (United Nations 2003).
Biogeography of the birds of the Bahamas with special reference to the island of San Salvador

Abstract We used original data (mist net captures) from San Salvador and Andros Island and literature sources for 19 islands in the Bahamas to conduct a biogeographic analysis of the permanent resident, terrestrial bird communities in the archipelago. The number of regularly occurring resident species on the 19 islands varied between 6 and 35 species. Island area accounted for 76% of the variation in richness, but multivariate analyses showed that vegetation and topography also affected richness: the richest communities were found on large islands that were dominated by pines and which had the highest topographic relief. Separate analyses of raptors, pigeons and doves, near-passerines, and passerines confirmed the primacy of island area as a determinant of richness among all groups except passerines. Among the latter species, area effects were secondary to vegetation type and elevation. The number of bird species on San Salvador conformed closely to the number predicted based on island area alone, but hab...
A 12-bit 50M samples/s digitally self-calibrated pipelined ADC

This thesis describes the different aspects of the design and implementation of a I2-bit 50M samplesjs pipelined non-binary radix 1.9 analog-to-digital converter. The converter architecture is made up of 14 stages with an interstage gain of 1.9 (non-binary radix). Each stage is made of one fully differential sample-and-hold amplifier (SHA), a I-bit sub-ADC (basically one comparator) and a I-bit DAC. The sub-DAC functionality is rolled in as part of the SHA switch capacitor architecture which is referred to as the multiplying DAC (MDAC). The self-calibration function is performed in a cyclical fashion and the entire pipeline is used to perform the calibration for each stage. The settling time on the MDAC is about 9ns with a gain of approximately SIdB. The entire pipeline has been implemented in a digital O.35/lm CMOS process.
Developing Mecca: A Case Study of the Royal Makkah Clock Tower

This paper surveys the legal and political structure of Saudi land-use decisions in Mecca and reaches preliminary hypotheses regarding the decision to build the Royal Makkah Clock Tower in Mecca. The Clock Tower, which is the second tallest building in the world and part of the world's largest building complex, is located immediately opposite from the Great Mosque in a remarkable juxtaposition of religion and modernity. The paper suggests that a reasonable hypothesis for the motivation to build the building is that it reflects the Saudi government's focus on developing Mecca to deal with the enormous crowds of pilgrims that come for the four-day hajj and throughout the year, but that ideological and financial interests might have played a role as well.
Association of toxic shock toxin-1 determinant with a heterologous insertion at multiple loci in the Staphylococcus aureus chromosome.

Abstract Most Staphylococcus aureus strains associated with toxic shock syndrome and producing toxic shock syndrome toxin 1 (TSST-1) require tryptophan because of a genetic defect in tryptophan biosynthesis. The association between TSST-1 production and tryptophan auxotrophy was not correlated with the phage type, the colonization site, or the disease status of the patient from whom the isolate came. Protoplast fusion and transformation mapping located the genetic determinant of TSST-1 production (tst) very close to the trp operon in such strains and very close to tyrB in a Trp+ TSST-1+ strain. Southern blot hybridization of ClaI-restricted chromosomal DNA with a tst-specific probe revealed a common homologous segment in all of the Trp+ strains with tst linked to tyrB. These results confirmed that the tst determinant in Trp- strains is located at one site, whereas in Trp+ TSST-1+ strains the determinant is located elsewhere on the S. aureus chromosome. It is suggested that the TSST-1 determinant is associated with the insertion of a transposonlike segment into several sites on the S. aureus chromosome.
Analysis of residual stress in failed T-28 femoral stems.

Retrieved stainless steel (Type 316L) T-28 femoral stems occasionally exhibit cracks on the medial surface. Since this region is loaded in compression during gait, a simple fatigue fracture explanation is not sufficient to account for these cracks. It has been suggested that they are related to residual stress. It is known that residual stress can contribute a large part of the strain energy near a crack tip. Four failed T-28 femoral stems have been analyzed after surgical retrieval. All of them had multiple visible cracks on the medial side in the region 2–5 cm distal to the calcar collar. All had failed by transverse fractures connecting with a crack on the medial side. These stems have been examined for residual stress by x-ray diffraction methods; significant levels of residual stress were found to be present in the sections tested. Stresses in the transverse direction (medial to lateral) were found to be strongly tensile near the lateral edge and changed to compressive near the medial edge. The area ...
Judging a Book by its Cover

Most interpretations of Bernard Picart's encyclopedic Ceremonies et coutumes religieuses de tous les peuples du monde, published originally in Amsterdam in seven oversized volumes (1723–1737), have stressed the artist's objective portrayal of diverse religions. The opening volume has been the subject of much scholarship, particularly focusing on Picart's even-handed treatment of Judaism, a notable distinction considering the denigration of Jews in both history and art history for centuries. In this article, I aim to nuance previous assessments of Picart as an unbiased portrayer of Jews by paying special attention to his often overlooked, crucial frontispiece, which complicates his larger agenda. This allegorical opening engraving conspicuously diverges from the descriptive, straightforward pictorial language and ethnographic approach found mostly throughout Ceremonies. Closer examination of Picart's summary depiction of religions, in conjunction with ancillary visual sources, demonstrates a more partial a...
A Profile of the Academy of Management Member: Comment

The article reports the author's opinions regarding the article “A Profile of the Academy of Management Member,” by Roderick A. Forsgren, published in the March 1969 issue. The author focuses on co...
Microgeographic and temporal genetic variation in populations of the bluetongue virus vector Culicoides variipennis (Diptera: Ceratopogonidae).

Seven Colorado populations of the bluetongue virus vector Culicoides variipennis (Coquillett) were analyzed for genetic variation at 19-21 isozyme loci. Permanent populations, which overwinter as larvae, showed little temporal genetic change at 19 loci. PGD and MDH showed seasonal changes in gene frequencies, attributable to selection at two permanent populations. Two temporary populations showed low heterozygosity compared with permanent populations. Independent estimates of gene flow, calculated using F ST and the private allele method, were Nm * =2.15 and 6.95, respectively. Colorado C. variipennis permanent populations showed high levels of gene flow which prevented significant genetic differentiation due to genetic drift. Temporary populations showed significant gene frequency differences from nearby permanent populations due to the «founder effect» associated with change colonization