cssi/SciSciGPT-SciSciNet huggingface dataset:
Fracture mechanics of sharp scratch strength of polycrystalline alumina

The strength of a polycrystalline alumina containing controlled scratches introduced by translated sharp contacts is investigated and described by a multiscale fracture mechanics model. Inert strength measurements of samples containing quasi-static and translated Vickers indentation contacts showed that scratches degraded the strength at normal contact loads an order of magnitude less than those for quasi-static indentation. The fracture mechanics model developed to describe strength degradation by scratches over the full range of contact loads included toughening effects by crack-wake bridging at the microscale and lateral crack-based residual stress relaxation effects at the mesoscale. A critical element of the model is the nonlinear scaling of the residual stress field of a scratch with the normal contact load acting during scratch formation. The similarities and differences in the scratch model in comparison with prior indentation-strength fracture mechanics models are highlighted by parallel development of both. Central to the scratch model is the use of easily controlled normal contact load as the scratch-strength measurement variable. Scratch length and orientation are shown to have significant effects on strength. The distributions of scratch widths controlling the intrinsic strengths of as-received samples are determined and agreement with the observed scratch dimensions is demonstrated.
Hybrid-Capacitors with Polyaniline/Carbon Electrodes Fabricated via Simultaneous Electrospinning/Electrospraying

Abstract Hybrid-capacitors have the potential to synergistically combine the benefits of both electrochemical double layer capacitors (EDLCs) (long cycle life) and Faradaic-capacitors (high capacitance). However, new processes that intimately combine the two primary materials from each capacitor (carbon and conductive polymer, respectively) within the electrodes in an ordered fashion on the nanoscale are needed to realize this potential. In this study, we report on a novel method (simultaneous electrospinning/electrospraying (E/E)) for fabricating hybrid-capacitors with high surface area electrodes consisting of polyaniline (PANI) and carbon nanoparticles (referred to as E/E electrodes). E/E produces a unique nanofiber/particle network of PANI and carbon. The hybrid-capacitor with E/E electrodes exhibits an excellent specific capacitance of 235 F g−1 (vs. 138 Fg−1 for capacitor with state-of-the art hybrid electrodes) at a current density of 1 A g−1. Moreover, the hybrid-capacitor with E/E electrodes retains approximately 84% capacitance after 1000 charge-discharge cycles (vs. 67% for capacitor with state-of-the art hybrid electrodes). These results indicate the feasibility of producing E/E electrodes and their promise as future materials in hybrid-capacitors.
REM (Rapid Eye Movement) Sleep

Rapid eye movement (REM) sleep is commonly associated with dreams, and is characterized by specific physiological features that distinguish it from other sleep stages. The electrophysiological features associated with REM sleep are rapid eye movements, low voltage-mixed frequency electroencephalogram (EEG), and muscle atonia. The key brain structures responsible for producing this sleep stage are located in the brainstem. The disruption of pathways involved with REM sleep can affect various electrophysiological components of REM sleep and can result in clinical conditions such as narcolepsy and REM sleep behavior disorder. The biological purpose of REM sleep is not clear, though it seems that it has a role in consolidating procedural memories.
Theoretical Framework for Network Modeling for Sustainability

The growth of new sustainable technologies and processes requires fundamental systems modeling methodologies to assess and predict their performance. This article describes theoretical frameworks for complex network modeling for sustainability. It begins with basic Markovian models, including Markov chains and hidden and hierarchical hidden Markov models. It then moves to more advanced Bayesian methods, including Bayesian networks and dynamic Bayesian networks. Each of these frameworks is described, including their definitions, properties, and relevance to network modeling for sustainability. As probabilistic graphical frameworks, they are able to capture the complex interdependencies in sustainable systems, the interactions of components comprising any given system, and the intricate and often uncertain network dynamics for sustainable systems.
Applying a common framework to develop undergraduate control systems laboratory kits

In the literature, there are many examples of control systems laboratory experiments and equipment. However, the information provided about these laboratories is not consistent. This paper applies a common framework for control systems laboratories to compare six existing low-cost laboratory kits for control systems and mechatronics. The framework contains learning objectives, components of a laboratory apparatus, and concepts for undergraduate control systems courses. It was developed based on a series of surveys of the control systems community. Additionally, a procedure is provided for how to apply the common framework for new laboratory developments and to improve consistency and ease of comparison of laboratories in the future. Due to diversity and differences between the disciplines that teach control systems, this procedure is provided as a guide rather than a prescriptive set of instructions. While using the procedures, instructors may select from the items on each list of the common framework to develop an effective laboratory experience for their students but are encouraged to explain the rationale for which items were selected when sharing their laboratory experience with other instructors. While previous literature has lacked the consistency of details, the goal of this paper is to show how this common framework can be applied in the future to increase understanding and transferability of control systems laboratories across institutions and disciplines.
Maternal heterosis and grandmaternal effects in beef cattle: preweaning traits.

Crossbred progeny from females, 3 yr old and older, representing Brown Swiss (B), Red Poll (R), Hereford (H) and Angus (A) maternal grandsires and maternal granddams in a diallel crossing experiment were evaluated to estimate breed mean maternal heterosis (mean hMi) for each breed, maternal heterosis for specific breed cross females (hMij), average maternal heterosis for all crosses (mean hM) and breed grandmaternal effects (gM'i) for preweaning calf traits. Estimates of mean hM were significant for birth date and weight, 200-d weight and 200-d weight/cow exposed. Even though calves with crossbred dams weighed more at birth, they did not differ from calves with straightbred dams in frequency of calving assistance. The estimates of hMij were similar for most crosses and most traits, except 200-d weight and 200-d weight/cow exposed. The largest heterotic advantage was exhibited by progeny of BH reciprocal cross females, which exceeded crossbred progeny from BB and HH females for 200-d weight/cow exposed by 35.9 kg. The smallest heterotic effect was exhibited by crossbred progeny of RA reciprocal cross females. Progeny with R maternal granddams exhibited a higher (P less than .05) live calf born and weaned percentage than progeny with H maternal granddams. Progeny with B maternal granddams were born later (P less than .05) in the calving season than progeny with R maternal granddams. Progeny with A maternal granddams exhibited a lower frequency of calving assistance than progeny with H maternal granddams, and progeny with H maternal granddams were heavier (P less than .05) at 200 d than progeny with R maternal granddams. There was a tendency for estimates of breed grandmaternal effects (gMi) to exhibit an inverse relationship with estimates of breed maternal effects (gMi).
A bioinformatics course in the computer science curriculum

Many colleges and universities have recently begun offering courses and degree programs in bioinformatics. This paper describes an Introduction to Bioinformatics course that emphasizes the informatics issues, and can be taught to upper-level undergraduate computer science students and graduate students. The course can be adapted to fit the interests and experience of a faculty member in computer science who has only a moderate amount of familiarity with molecular biology.
Modeling time-varying effects of multilevel risk factors of hospitalizations in patients on dialysis.

For chronic dialysis patients, a unique population requiring continuous medical care, methodologies to monitor patient outcomes, such as hospitalizations, over time, after initiation of dialysis, are of particular interest. Contributing to patient hospitalizations is a number of multilevel covariates such as demographics and comorbidities at the patient level and staffing composition at the dialysis facility level. We propose a varying coefficient model for multilevel risk factors (VCM-MR) to study the time-varying effects of covariates on patient hospitalization risk as a function of time on dialysis. The proposed VCM-MR also includes subject-specific random effects to account for within-subject correlation and dialysis facility-specific fixed effect varying coefficient functions to allow for the modeling of flexible time-varying facility-specific risk trajectories. An approximate EM algorithm and an iterative Newton-Raphson approach are proposed to address the challenge of estimation of high-dimensional parameters (varying coefficient functions) for thousands of dialysis facilities in the United States. The proposed modeling allows for comparisons between time-varying effects of multilevel risk factors as well as testing of facility-specific fixed effects. The method is applied to model hospitalization risk using the rich hierarchical data available on dialysis patients initiating dialysis between January 1, 2006 and December 31, 2008 from the United States Renal Data System, a large national database, where 331 443 hospitalizations over time are nested within patients, and 89 889 patients are nested within 2201 dialysis facilities. Patients are followed-up until December 31, 2013, where the follow-up time is truncated five years after the initiation of dialysis. Finite sample properties are studied through extensive simulations.
Effect of Macrolide and Rifampin Resistance on the Fitness of Rhodococcus equi.

ABSTRACT Rhodococcus equi is a leading cause of severe pneumonia in foals. Standard treatment is dual antimicrobial therapy with a macrolide and rifampin, but the emergence of macrolide- and rifampin-resistant R. equi isolates is an increasing problem. The objective of this study was to determine the effect of macrolide and/or rifampin resistance on fitness of R. equi. Three unique isogenic sets were created, each consisting of four R. equi strains, as follows: a susceptible parent isolate, strains resistant to macrolides or rifampin, and a dual macrolide- and rifampin-resistant strain. Each isogenic set’s bacterial growth curve was generated in enriched medium, minimal medium (MM), and minimal medium without iron (MM-I). Bacterial survival in soil was analyzed over 12 months at −20°C, 4°C, 25°C, and 37°C, and the ability of these strains to retain antimicrobial resistance during sequential subculturing was determined. Insertion of the mobile element conferring macrolide resistance had minimal effect on in vitro growth. However, two of three rpoB mutations conferring rifampin resistance resulted in a decreased growth rate in MM. In soil, macrolide- or rifampin-resistant R. equi strains exhibited limited growth compared to that of the susceptible R. equi isolate at all temperatures except −20°C. During subculturing, macrolide resistance was lost over time, and two of three rpoB mutations reverted to the wild-type form. The growth of rifampin-resistant R. equi colonies is delayed under nutrient restriction. In soil, possession of rifampin or macrolide resistance results in decreased fitness. Both macrolide and rifampin resistance can be lost after repeated subculturing. IMPORTANCE This work advances our understanding of the opportunistic environmental pathogen Rhodococcus equi, a disease agent affecting horses and immunocompromised people. R. equi is one of the most common causes of severe pneumonia in young horses. For decades, the standard treatment for R. equi pneumonia in horses has been dual antimicrobial therapy with a macrolide and rifampin; effective alternatives to this combination are lacking. The World Health Organization classifies these antimicrobial agents as critically important for human medicine. Widespread macrolide and rifampin resistance in R. equi isolates is a major emerging problem for the horse-breeding industry and might also adversely impact human health if resistant strains infect people or transfer resistance mechanisms to other pathogens. This study details the impact of antimicrobial resistance on R. equi fitness, a vital step for understanding the ecology and epidemiology of resistant R. equi isolates, and will support development of novel strategies to combat antimicrobial resistance.
A Smartphone-Based System for Improving Pedestrian Safety

With the prevalence of smartphones, pedestrians and joggers today often walk or run while listening to music. Since they are deprived of their auditory senses that would have provided important cues to dangers, they are at a much greater risk of being hit by cars or other vehicles. In this article, we present PAWS, a smartphone platform that utilizes an embedded wearable headset system mounted with an array of MEMS microphones to help detect, localize, and warn pedestrians of the imminent dangers of approaching cars.
Business ethics in the broiler industry

The chicken meat, or broiler, business in the United States is a vertically integrated industry in which integrator corporations control all aspects of the business. Primarily through a series of business acquisitions, an industry duopoly has evolved. The two dominant integrator corporations, Pilgrim's Pride and Tyson Foods, are profitable, and their officers and stockholders benefit from the corporations’ financial success. The multitude of local growers who nurture the chickens to maturity for the integrators, however, benefit minimally from the financial success of the integrators, as the growers face a myriad of financial, environmental, community, and health problems. Many growers have difficulty in extracting themselves from an occupation that requires their initial, personal expenditure, or debt of hundreds of thousands of dollars. Additionally, many who live in regions or states of broiler growing facilities suffer from gases emitted by these facilities and correspondingly lower property values. Several demographic, economic, education, health, and quality of life metrics were analyzed for the 50 U.S. states to provide insights regarding the ethics of the broiler industry and why some states produce significantly more broilers than others.
Rapid and Efficient Trifluoromethylation of Aromatic and Heteroaromatic Compounds Using Potassium Trifluoroacetate Enable by a Flow System.

This simple, scalable, and efficient protocol represents the first example of a trifluoromethylation conducted under flow conditions using CF3COOK as -CF3 source.
Spin determination of resonances in 165Ho(n, γ) from low-level occupation probability ratios

Abstract The dependence of the low-level occupation probabilities on the compound state spin has been used to assign spin values to fourteen resonances in the reaction 165Ho(n,γ)165Ho within the neutron energy range from 18 to 86 eV. The low-level occupation probabilities were determined from the intensities ofγ-rays de-exciting these levels. These intensities have been measured in a time-of-flight experiment at the Rensselaer electron linear accelerator using a Ge(Li) detector. The spins assigned in the present experiment agree with those of the seven resonances where spin values have been recommended in BNL 325.
Successful Use of Renal Replacement Therapy for Refractory Hypokalemia in a Diabetic Ketoacidosis Patient

A 39-year-old African-American female presented to the emergency department with a seven-day history of right upper quadrant abdominal pain accompanied by nausea, vomiting, and diarrhea. She was noted to be alert and following commands, but tachypneic with Kussmaul respirations; and initial laboratory testing supported a diagnosis of diabetic ketoacidosis (DKA) and hypokalemia. To avoid hypokalemia-induced arrhythmias, insulin administration was withheld until a serum potassium (K) level of 3.3 mEq/L could be achieved. Efforts to increase the patient’s potassium level via intravenous repletion were ineffectual; hence, an attempt was made at more aggressive potassium repletion via hemodialysis using a 4 mEq/L K dialysate bath. The patient was started on Aldactone and continuous veno-venous hemodialysis (CVVH) with ongoing low-dose insulin infusion. This regimen was continued over 24 h resulting in normalization of the patient’s potassium levels, resolution of acidosis, and improvement in mental status. Upon resolution of her acidemia, the patient was transitioned from insulin infusion to treatment with a subcutaneous insulin aspart and insulin detemir, and did not experience further hypokalemia. Considering our success, we propose CVVH as a tool for potassium repletion when aggressive intravenous (IV) repletion has failed.
Revisiting the Religious Violence Thesis: Minorities in the Middle East

Why do ordinary individuals participate in political campaigns involving mass looting, killings, and enslavement against members of another religious group? This paper argues that religious justifications of violence have a stronger appeal when they target liminal minorities whose beliefs and norms remain illegible in the eyes of a majority religion. It then formulates a series of alternative hypotheses about the role of greed, threat, resentment, and guilt in the motives of perpetrators and uses the self-styled Islamic State (IS) campaign against Yezidis in 2014 as a case study to test these hypotheses . Empirical evidence comes from extensive fieldwork including dozens of in-depth interviews with Yezidi survivors and others in Iraqi Kurdistan. The analysis reveals that religious beliefs were necessary both for making extreme levels of violence permissible and for mobilizing local population to participate in the atrocities.
Dermal regeneration sheet Integra® in management of recurrent Urethrocutaneous fistula after hypospadias surgery.

Summary Background Urethrocutaneous fistula UCF is the most common complication following surgical repair of hypospadias. Currently, the surgical technique mostly used to prevent recurrence employs preputial dartos or testicular tunica vaginalis flaps as a urethral covering. However, autologous tissues are limited in patients with multiple surgeries, and the use of biomaterials as a urethral coverage may represent a good alternative. Objective The goal of the present study is to assess the results and complications of recurrent UCF correction using a dermal bovine regeneration sheet as a urethral covering. Materials and method From May 2016 to January 2019, all patients with recurrent UCF of the authors center were repaired using this technique. The inclusion criteria were patients who had undergone one or more unsuccessful UCF repair surgeries and the absence of preputial tissue. The informed consent has been signed by all the patients. Patients were examined in outpatient consultations where their urinary stream was evaluated and a physical examination of the penis was conducted. Results A total of 12 patients and 13 UCFs were included in the study. The median follow-up was 18 months, (range: 4–26), and only two patients (15%) developed a recurrence of UCF. No complications were observed in the remaining patients (85%) during their evolution. No patient developed a fibrosis increase or loss of elasticity of the tissues in contact with the dermal matrix. Conclusion The use of an Integra® sheet as a urethral covering during urethral fistula surgery appears to be a safe, effective, and easily reproducible option. However, prospective studies with larger numbers of patients should be performed to corroborate these results. Summary Table Patient Age (years) No. of fistulas Fistula size (mm) Days with catheter Monitoring time (months) Complications 1 5 1 3 mm 4 26 No 2 3 2 3 mm 7 26 No 4 mm 3 5 1 3 mm 4 25 No 4 6 1 3 mm 5 22 Fistula 5 10 1 3 mm 5 22 No 6 13 1 2 mm 2 22 No 7 9 1 3 mm 2 18 No 8 9 1 3 mm 2 18 No 9 7 1 3 mm 3 14 No 10 6 1 2 mm 5 14 Fistula 11 3 1 3 mm 5 14 No 12 3 1 3 mm 6 4 No
Echocardiography-Guided Dual-Lumen Venovenous Extracorporeal Membrane Oxygenation Cannula Placement in the ICU-A Retrospective Review.

Objective The most effective method of image guidance for venovenous extracorporeal membrane oxygenation is not known. The authors’ objectives were to define the frequency of successful initial cannulation using echocardiographic guidance in the intensive care unit, as well as to determine the frequency of subsequent adjustments. Additional aims were to illustrate cannula malposition problems and to describe features associated with difficult cannulation. Design Retrospective consecutive case series analysis. Setting Single tertiary care university hospital. Participants Forty-five patients treated with venovenous extracorporeal membrane oxygenation. Interventions None. Measurements and Main Results The most common causes of respiratory failure were pneumonia, aspiration, and inhalational burn injury. Sixty-two percent survived to discharge. Initial cannulation was successful in 39 cases (87%). Adverse events included 5 cases of cannula malposition and 1 case of hemorrhagic shock. During the course of extracorporeal membrane oxygenation, 17 patients (38%) required echo-guided cannula position adjustments. There were no fatal complications. Factors associated with difficult cannulation included extremes of size, a prominent Eustachian valve, and an anterior guidewire bending in the right atrium. Younger age was associated positively with survival. There was no significant association between adverse events during cannulation and survival. Conclusions Dual-lumen venovenous extracorporeal membrane oxygenation cannulation in the intensive care unit under echo guidance has a high initial success rate, but many patients require subsequent repositioning. Echocardiography can define cannula position in sufficient detail to identify malposition precisely and to guide repositioning.
The Problem of Equality in Takings

The Supreme Court is finally beginning to bring clarity to the law of regulatory takings and in the process is bringing to the fore a previously submerged theme in the jurisprudence: regulatory takings as a question of distributional justice and horizontal equity. This Article argues that this equality dimension is fundamentally problematic. On a theoretical level, privileging norms of equality engrafts political process rationales for heightened scrutiny onto groups defined solely by the differential burden of a regulation, an exercise in circularity. Equally troubling is the inverted political economy of regulatory takings claims that is likely to result: the greatest judicial protection is provided to those most able to navigate the political system. And from a doctrinal perspective, an overly robust equality inquiry housed in the Takings Clause is inherently indeterminate, warping not only the fabric of takings but also of equal protection jurisprudence. Accordingly, this Article argues that concerns about the uneven distribution of regulatory burdens should sound not under the Takings Clause but rather under the Equal Protection Clause, with its deferential standards for the review of ordinary economic and social regulation. Excising the equality dimension of regulatory takings would properly leave the Takings Clause as a guard against those rare regulatory actions that are functionally equivalent to the direct exercise of eminent domain. The result would be a simpler, clearer, and ultimately more egalitarian law of takings.
AUTOMATED COMPOSITION OF WEB SERVICE WORKFLOW - A Novel QoS-Enabled Multi-Criteria Cost Search Algorithm

The introduction of software technology has dramatically increased the efficiency of completing tasks. Code reusability provides efficiency within the software engineering discipline. With the tumultuous increase in acceptance of service oriented architecture, and thus, a rise in the number of web services, skilled software developers spend a lot of time composing web service workflows, rather than creating innovative and efficient services. Hence, we put forward a technique of code reusability that utilizes heuristic based search methods to automate service workflow composition by weighting quality of service criteria by relevance and importance to the users. We implement a novel and heuristic-based graph creation and search algorithm where the heuristic function value is calculated through the uniform cost search based on each of the quality of service criteria specified by the user. Application of the proposed automated workflow composition algorithm is illustrated with success on an industry-grade service-oriented architecture problem.
JUE Insight: College Student Travel Contributed to Local COVID-19 Spread

Due to the suspension of in-person classes in response to the COVID-19 pandemic, students at universities with earlier spring breaks traveled and returned to campus while those with later spring breaks largely did not. We use variation in academic calendars to study how travel affected the evolution of COVID-19 cases and mortality. Estimates imply that counties with more early spring break students had a higher growth rate of cases than counties with fewer early spring break students. The increase in case growth rates peaked two weeks after spring break. Effects are larger for universities with students more likely to travel through airports, to New York City, and to popular Florida destinations. Consistent with secondary spread to more vulnerable populations, we find a delayed increase in mortality growth rates. Lastly, we present evidence that viral infection transmission due to college student travel also occurred prior to the COVID-19 pandemic.
Enhancing mobile cloud with social-aware device-to-device offloading

Abstract Mobile cloud computing has been widely used to support the computation-intensive applications in mobile devices. Since cloud computing relies on the facilities like network infrastructures and cloud servers, the cloud service can be easily hampered by the limitation of these facilities in many cases. Therefore, researchers proposed the concept of device-to-device offloading to offload workload to nearby devices, without going through other facilities. Most existing works on device-to-device offloading aim to minimize the execution time of tasks or minimize the energy consumption. These works assume devices can be connected for a long time, but they neglect the fact that the connections among mobile devices are usually intermittent and even opportunistic, which may render the failure of task offloading. In this paper, we propose a new approach, PeerCloud, that aims to improve the success ratio of task offloading. Specifically, since mobile devices are carried by human beings, we study the social relationship between the device carriers and discover the hidden regularity in their contact patterns, in order to predict the likelihood of node departure. Optimization problems are then formalized to maximize the success ratio of task offloading within tasks’ time constraints. Experimental results based on three real-world datasets demonstrate that PeerCloud outperforms existing approaches by significantly improving the success ratio.
A Server-Assisted Loosely Coupled Cooperative Localization Under Limited Connectivity

This letter studies the global localization of a group of communicating mobile agents via a dead-reckoning system aided by occasional interagent relative measurements. We consider a setting that communication network is unreliable and maintaining network-wide connectivity is not possible at all times. We propose a hybrid approach that improves the localization performance of a loosely coupled cooperative localization algorithm by fusing its estimates with those obtained opportunistically from a server-assisted tightly coupled cooperative localization. The resulting hybrid algorithm inherits the advantages of both of its constituting algorithms. A numerical example demonstrates our results.
The Plasmodium NOT1-G paralogue is an essential regulator of sexual stage maturation and parasite transmission.

Productive transmission of malaria parasites hinges upon the execution of key transcriptional and posttranscriptional regulatory events. While much is now known about how specific transcription factors activate or repress sexual commitment programs, far less is known about the production of a preferred mRNA homeostasis following commitment and through the host-to-vector transmission event. Here, we show that in Plasmodium parasites, the NOT1 scaffold protein of the CAF1/CCR4/Not complex is duplicated, and one paralogue is dedicated for essential transmission functions. Moreover, this NOT1-G paralogue is central to the sex-specific functions previously associated with its interacting partners, as deletion of not1-g in Plasmodium yoelii leads to a comparable or complete arrest phenotype for both male and female parasites. We show that, consistent with its role in other eukaryotes, PyNOT1-G localizes to cytosolic puncta throughout much of the Plasmodium life cycle. PyNOT1-G is essential to both the complete maturation of male gametes and to the continued development of the fertilized zygote originating from female parasites. Comparative transcriptomics of wild-type and pynot1-g− parasites shows that loss of PyNOT1-G leads to transcript dysregulation preceding and during gametocytogenesis and shows that PyNOT1-G acts to preserve mRNAs that are critical to sexual and early mosquito stage development. Finally, we demonstrate that the tristetraprolin (TTP)-binding domain, which acts as the typical organization platform for RNA decay (TTP) and RNA preservation (ELAV/HuR) factors is dispensable for PyNOT1-G’s essential blood stage functions but impacts host-to-vector transmission. Together, we conclude that a NOT1-G paralogue in Plasmodium fulfills the complex transmission requirements of both male and female parasites.
The fate of sodium chlorite in simulated gastric and intestinal fluids and residues of chlorate in broiler chickens after oral administration of sodium chlorite.

The fate of sodium [36Cl]chlorite in simulated intestinal fluids and residues of chlorate in broiler chickens fed 0, 10, 100, or 1000 mg•kg-1 of dietary sodium chlorite for 7 days was determined. [36Cl]Chlorite was stable in water and simulated intestinal fluid during 6 h incubations but was rapidly degraded to chlorine dioxide, sodium chloride, and sodium chlorate in simulated gastric fluids. Addition of starch, citrate, or soybean shifted the relative proportions of chloroxyanions formed; addition of ferrous chloride caused quantitative formation of sodium chloride in gastric and intestinal fluids. [36Cl]Chlorite underwent reductive transformation when fortified into chicken serum. Residues of chlorate in broiler chickens ranged from 3.5 to 374 ng•g-1 in gizzard, were <6.8 to 126 ng•g-1 in liver and were <7.2 to 190 ng•g-1 in muscle when slaughtered with no withdrawal period. Data are presented suggesting that reductive processes govern the fate of chlorite when present in closed biological systems.
What does the Dementia Rating Scale-2 measure? The relationship of neuropsychological measures to DRS-2 total and subscale scores in non-demented individuals with Parkinson's disease.

Objective The Dementia Rating Scale-2 (DRS-2) is recommended for assessing global cognition in Parkinson's disease (PD) by the Movement Disorder Society. However, empirical evidence is limited regarding the degree to which the DRS-2 corresponds to traditional neurocognitive domains (i.e., construct validity) in PD. Thus, this study aims to determine the construct validity of the DRS-2 in a non-demented sample of PD patients. Method Patients with PD (n = 359; mean age = 64.50 ± 8.53, education = 14.97 ± 2.73, disease duration = 8.48 ± 4.87, UPDRS Part III motor scale scores = 25.23 ± 10.17) completed the DRS-2 as part of a comprehensive neuropsychological assessment consisting of attention/working memory, executive function, language, delayed recall, and visuoperceptual-spatial skills.Bootstrapped bias-corrected Spearman rho's correlations andhierarchical linear regressions were performed to examine construct validity of DRS-2 total and subscale scores. Results Speeded measures of set-shifting, rapid word generation to letter and semantic cues, and simple visuoperceptual skills largely accounted for variance in DRS-2 total scores. Most DRS-2 subscale scores showed weak relationships with theoretically related neuropsychological measures. Conclusions DRS-2 total scores reflect impairment across a range of cognitive domains (i.e., executive, language, and visuoperception), while DRS-2 subscale scores have limited construct validity. Together, the DRS-2 does not appear to have utility beyond screening for global cognition in PD.
1 – Biomaterials and scaffolds for musculoskeletal tissue engineering

This chapter reviews current research being undertaken in biomaterials and scaffolds for musculoskeletal tissue repair and regeneration. The bulk of the chapter is focused on natural and synthetic biodegradable biomaterials, physical property requirements and biomaterial fabrication into three-dimensional and interconnected porous structures for the regeneration of musculoskeletal tissues (bone, tendon, ligament, etc.), as well as tissue interfaces (bone/cartilage, bone/tendon, etc.). Because biomaterials and scaffolds serve as a principal component of tissue engineering, it is important to develop matrices that serve as functional replacements for the musculoskeletal tissues and for better and clinically relevant regeneration. The progress made and the challenges remaining to be addressed are reviewed toward the end.
Practical Aspects of Measuring Intracellular Calcium Signals with Fluorescent Indicators

The use of fluorescent indicators for monitoring calcium (Ca(2+)) signals and for measuring Ca(2+) concentration ([Ca(2+)]) in living cells is described. The following topics are covered in detail: (1) ratiometric and nonratiometric fluorescent indicators and the principles underlying their use, (2) techniques for loading Ca(2+) indicators and Ca(2+) buffers into living cells, (3) calibration of indicator fluorescence intensity measurements to yield values of intracellular [Ca(2+)], (4) analysis of nonratiometric fluorescence intensity data and caveats relating to their interpretation, (5) techniques for manipulating intracellular and extracellular [Ca(2+)], and (6) the use of fluorescent indicators to monitor Ca(2+) signals in mitochondria. The chapter aims to present these fundamental topics in a manner that is practically useful and intuitively accessible. The origins of key mathematical equations used in the article are outlined in two appendices.
The "limiting line" in mixed subsonic and supersonic flow of compressible fluids

It is well known that the vorticity for any fluid element is constant if the fluid is non-viscous and the change of state of the fluid is isentropic. When a solid body is placed in a uniform stream, the flow far ahead of the body is irrotational. Then if the flow is further assumed to be isentropic, the vorticity will be zero over the whole filed of flow. In other words, the flow is irrotational. For such flow over a solid body, it is shown by Theodorsen that the solid body experiences no resistance. If the fluid has a small viscosity, its effect will be limited in the boundary layer over the solid body and the body will have a drag due to the skin friction. This type of essentially isentropic irrotational flow is generally observed for a streamlined body placed in a uniform stream, if the velocity of the stream is kept below the so-called "critical speed." At the critical speed or rather at a certain value of the ratio of the velocity of the undisturbed flow and the corresponding velocity of sound, shock waves appear. This phenomenon is called the "compressibility bubble." Along a shock wave, the change of state of the fluid is no longer isentropic, although still adiabatic. This results in an increase in entropy of the fluid and generally introduces vorticity in an originally irrotational flow. The increase in entropy of the fluid is, of course, the consequence of changing part of the mechanical energy into heat energy. In other words, the part of fluid affected by the shock wave has a reduced mechanical energy. Therefore, with the appearance of shock waves, the wake of the streamline body is very much widened, and the drag increases drastically. Furthermore, the accompanying change in the pressure distribution over the body changes the aerodynamic moment acting on it and in the case of an airfoil decreases the lift force. All these consequences of the breakdown of isentropic irrotational flow are generally undesirable in applied aerodynamics. Its occurrence should be delayed as much as possible by modifying the shape or contour of the body. However, such endeavor will be very much facilitated if the cause or the criterion for the breakdown can be found first.
Costly Communication in Groups: Theory and an Experiment

I develop a novel model of group-based deliberation in which communication is costly in two directions: agents must pay separate costs to send and to receive messages. Equilibrium strategies have an intuitive characterization - those with the best information send, those with the worst information receive. But free-riding leads to less information exchange than is optimal. Testing the model`s predictions with an experiment I find that subjects overcommunicate when costs are high, but fail to benefit from this as much as they should. In welfare terms the experiment finds that listening costs are more harmful to welfare, in contrast with theory, which indicates sending costs. The experiment also suggests that the existence of costly communication channels can reduce total welfare.
Unique ergodicity on compact homogeneous spaces

Extending results of a number of authors, we prove that if U is the unipotent radical of an 1R-split solvable epimorphic subgroup of a real algebraic group G which is generated by unipotents, then the action of U on G/l' is uniquely ergodic for every cocompact lattice F in G. This gives examples of uniquely ergodic and minimal two-dimensional flows on homogeneous spaces of arbitrarily high dimension. Our main tools are the Ratner classification of ergodic invariant measures for the action of a unipotent subgroup on a homogeneous space, and a simple lemma (the 'Cone Lemma') about representations of epimorphic subgroups. In his 1972 paper [F] Hillel Furstenberg proved that the horocycle flow on the unit tangent bundle to any compact Riemann surface is uniquely ergodic (i.e., admits a unique finite U-invariant Borel measure). This flow may be realized as the action of the subgroup U of upper-triangular matrices in L SL(2, IR) on the quotient of L by a cocompact lattice A, acting by u (tA) = (ut) A. Such an action is called a subgroup action on a homogeneous space. It follows from unique ergodicity that the action is minimal (i.e., any U-orbit is dense). Various generalizations of Furstenberg's result were subsequently obtained by a number of authors (see [V], [Bo], [EP], [D11). In these generalizations what is proved is unique ergodicity of the action of U on L/A, where L is a real algebraic group, U an algebraic subgroup which is unipotent (all its elements have all eigenvalues equal to 1 in a representation of L as a matrix group; in other words all its elements are unipotent) and A is a cocompact lattice. Typically in these results the dimension of the acting group U may be quite large. In this note we generalize these results. For example, for any simple noncompact L, we obtain a 2-dimensional unipotent U which acts uniquely ergodically on L/A for any cocompact lattice A. On the other hand we show by examples that L = SL(3, R) does not contain any one-dimensional U with this property. The two essential ingredients we shall use are Marina Ratner's theorems regarding actions of a unipotent subgroup on a homogeneous space, and a simple result concerning epimorphic subgroups. Recall that Ratner's Measure Classification Theorem (see [Ri], Theorem 1) asserts that if L, A are as above, and U is a connected subgroup of L generated by unipotent elements, then for any U-invariant U-ergodic Received by the editors April 22, 1999. 1991 Mathematics Subject Classification. Primary 22F30. (@)2000 American Mathematical Society
Altered Responsiveness to Cocaine and Increased Immobility in the Forced Swim Test Associated with Elevated cAMP Response Element-Binding Protein Expression in Nucleus Accumbens

Drugs of abuse regulate the transcription factor cAMP response element-binding protein (CREB) in striatal regions, including the nucleus accumbens (NAc). To explore how regulation of CREB in the NAc affects behavior, we used herpes simplex virus (HSV) vectors to elevate CREB expression in this region or to overexpress a dominant-negative mutant CREB (mCREB) that blocks CREB function. Rats treated with HSV-mCREB in place conditioning studies spent more time in environments associated with cocaine, indicating increased cocaine reward. Conversely, rats treated with HSV-CREB spent less time in cocaine-associated environments, indicating increased cocaine aversion. Studies in which drug–environment pairings were varied to coincide with either the early or late effects of cocaine suggest that CREB-associated place aversions reflect increased cocaine withdrawal. Because cocaine withdrawal can be accompanied by symptoms of depression, we examined how altered CREB function in the NAc affects behavior in the forced swim test (FST). Elevated CREB expression increased immobility in the FST, an effect that is opposite to that caused by standard antidepressants and is consistent with a link between CREB and dysphoria. Conversely, overexpression of mCREB decreased immobility, an effect similar to that caused by antidepressants. Moreover, the κ opioid receptor antagonist nor -Binaltorphimine decreased immobility in HSV-CREB- and HSV-mCREB-treated rats, suggesting that CREB-mediated induction of dynorphin (an endogenous κ receptor ligand) contributes to immobility behavior in the FST. Exposure to the FST itself dramatically increased CREB function in the NAc. These findings raise the possibility that CREB-mediated transcription within the NAc regulates dysphoric states.
Explaining stationary variables with non-stationary regressors

When variables included in an OLS regression are stationary, conventional statistical measures such as t-statistics and R 2's – in addition to a priori information from economic theory – are the standard indicators used to assess the performance of the hypothesized model. However, if the variables under consideration are non-stationary, such conventional measures no longer have the usual interpretation. With recent developments in time-series analysis, namely cointegration, researchers are able to deal with models containing non-stationary variables effectively. A standard cointegration model, however, requires all variables included in the regression to be of the same order of integration. In this paper we consider a regression in which the dependent variable is integrated of order zero, I(0), while the explanatory variables are integrated of order one, I(1). Conventional statistical measures are inapplicable because the regressors are not stationary. On the other hand, cointegration statistics are inapp...
Endothelial nitric oxide pathway function in the peripheral vasculature of patients with heart failure

Summary Many studies have investigated the pathophysiologiccontributions of abnormalities in the endothelial nitric oxide pathway to the heightened vasoconstrictor tone that is characteristic of the clinical syndrome of heart failure. The most consistent abnormality is a reduced vasodilator response to muscarinic stimulation with either acetylcholine or methacholine, a finding which has been identified in several animal models of heart failure as well as in forearm and leg resistance vessels in patients with heart failure. More recent studies with desmopressin, a vasopressin 2 receptor agonist that stimulates nitric oxide production independent of the muscarinic receptor, have demonstrated that the abnormality in endothelium-dependent vasodilation was not limited to the muscarinic pathway. At present, the mechanisms of the defect in the endothelial nitric oxide pathway are unknown. But, they appear not to be directly related to sympathetic stimulation. Finally, studies using transplant recipients have demonstrated that this defect is reversible. In addition, a pilot study has demonstrated that supplemental oral L-arginine, the precursor for nitric oxide, has beneficial effects on forearm blood flow responses to exercise, arterial compliance and functional status as assessed by increased distances during a 6-minute walk test and lower scores on the Living with Heart Failure Questionnaire. These studies suggest that the endothelial nitric oxide pathway may be a target for therapeutic interventions in heart failure.
Mechanical function and substrate oxidation in the neonatal pig heart subjected to pacing-induced tachycardia.

Abstract Isolated, paced, isovolumically beating, neonatal pig (≈2 days) hearts were perfused with a crystalloid solution during four periods: (1) baseline, HR 150 bpm; (2) HR-response curves, HR 150–360 bpm; (3) tachycardia, HR 300 bpm; and (4) posttachycardia, HR 150 bpm. Group I was studied with glucose (5.5 mM) as the sole substrate. During baseline, left ventricular peak systolic pressure (PSP) averaged 123 ± 7 mm Hg; end diastolic pressure (EDP), 4.9 ± 0.4 mm Hg; relaxation time constant (Tau), 29.5 ± 3.9 ms; glucose oxidation (14CO2from [14C]glucose), 1535 ± 96 nmol/min/gdry; and myocardial oxygen consumption (MVO2), 17.4 ± 0.4 μmol/min/gdry. During tachycardia, PSP was 83 ± 4* mm Hg; EDP, 9.8 ± 1.7* mm Hg; Tau, 29.9 ± 5.4 ms; glucose oxidation, 1921 ± 136* nmol/min/gdry; and MVO2, 21.1 ± 0.7* μmol/min/gdry(*different from baseline,P
Testing alternate predictions for the performance consequences of middle managers' discretion

Although discretion among employees at organizations' lower levels seems to be increasing, it is uncertain whether this is a desirable HRM policy. To understand this issue better, this study tests competing organization theory predictions about the performance consequences of middle managers' perceived discretion. Discretion is defined as the freedom of action or decision authority available in managing subordinates. Survey data from a multinational, European sample of research and development (R&D) units were used to assess the effect of managers' perceived discretion on unit performance. The results show that a combination of ecology theory and strategic choice theory best predicts the relationship between discretion and unit performance. Greater perceived managerial discretion was linked to increased unit performance in a relationship moderated by managerial experience and limited by unit size. These findings have implications for HRM theory and practice, particularly regarding policies related to empowerment and leadership development.