cssi/SciSciGPT-SciSciNet huggingface dataset:
Mg acceptor doping in MOCVD (010) β-Ga2O3

In this Letter, in situ Mg doping in β-Ga2O3 was demonstrated via metalorganic chemical vapor deposition (MOCVD) epitaxy. The electrical insulating property of the Mg acceptors in β-Ga2O3 was found to be intrinsically activated in the as-grown Mg-doped β-Ga2O3 thin films. Growth conditions for MOCVD β-Ga2O3 were further explored and optimized at a lower growth temperature regime, leading to a better confinement of the Mg-doping profile. Detailed analysis of Mg diffusion characteristics revealed a diffusion barrier energy Ebarrier ∼ 0.9 eV for Mg in MOCVD β-Ga2O3, which is likely related to an interstitial-assisted process. Surface morphologies and electron transport were characterized on samples grown with different growth temperatures and Mg doping levels. The MOCVD growth method demonstrated its feasibility to grow semi-insulating Mg-doped β-Ga2O3 epilayers with controllable Mg incorporation while maintaining good material quality and smooth surface morphology. From capacitance-voltage charge profiling, it is verified that the Mg-doped buffer layer grown at the substrate-epilayer interface could effectively compensate the charge accumulation at the interface. The in situ acceptor doping of Mg in MOCVD β-Ga2O3 will provide versatility for designing β-Ga2O3 power devices.
Macroscale Property Prediction for Additively Manufactured IN625 from Microstructure Through Advanced Homogenization

Design of additively manufactured metallic parts requires computational models that can predict the mechanical response of the parts considering the microstructural, manufacturing, and operating conditions. This article documents our response to Air Force Research Laboratory (AFRL) Additive Manufacturing Modeling Challenge 3, which asks the participants to predict the mechanical response of tensile coupons of IN625 as function of microstructure and manufacturing conditions. A representative volume element (RVE) approach was coupled with a crystal plasticity material model, solved within the fast Fourier transformation (FFT) framework for mechanics, to address the challenge. During the competition, material model calibration proved to be a challenge, prompting the introduction in this manuscript of an advanced material model identification method using proper generalized decomposition (PGD). Finally, a mechanistic reduced order method called self-consistent clustering analysis (SCA) is shown as a possible alternative to the FFT method for solving these problems. Apart from presenting the response analysis, some physical interpretation and assumptions associated with the modeling are discussed.
Cardiovascular Disease Risk Among Transgender People with HIV

Transgender individuals are at disproportionate risk for HIV infection, with prevalence rates highest among transgender women of color. Antiretroviral therapy (ART)-treated people with HIV (PWH) are at increased risk for cardiovascular disease (CVD), in relation to persistent systemic immune activation and metabolic dysregulation. The purpose of this review is to examine parameters which may affect CVD risk among transgender PWH. Among transgender women and men, prospective longitudinal studies have shown that gender-affirming hormonal therapy (GAHT) is associated with select deleterious cardiometabolic effects such as increases in visceral adipose tissue. Retrospective studies among transgender women and men suggest an increase in CVD risk, such as venous thromboembolism, cerebrovascular accidents, and myocardial infarction. Studies among transgender PWH adhering to GAHT and ART suggest heightened systemic immune activation/inflammation. Prospective longitudinal studies assessing factors associated with increased CVD events among transgender PWH are needed to guide the development of CVD prevention strategies in this at-risk population.
Exploring Boundaries: How Firms Choose Informality in Emerging Markets

How do firms choose between formal and informal strategies in emerging markets? While the existing literature focuses mostly on the effect of informality on firm outcomes, little research has been conducted on how these firms set strategies in response to their external environment. Using data on routes of minibus taxi operators in South Africa, we explore how the external environment informs this strategic choice. Through spatial and regression analysis, we find that firms choose over a spectrum of informality over time and space in response to demand and availability of public infrastructure. Investigating this phenomenon further through interviews with stakeholders throughout the minibus taxi industry, we find that these firms blend formal and informal strategies to maximize their profit-making potential in the face of insufficient infrastructure and economic and physical uncertainty.
Interviewing Exercises:Lessons from Family Therapy

Interviewing has become a widely used means for data generation in qualitative research. It is also a popular approach for counselors and therapists in their qualitative research projects. A major reason qualitative research-style interviewing is a favored technique with researching clinicians is that it is so similar to the way in which counselors and therapists interact with their clients in therapy sessions. Given this closeness in form, it would make sense that some of the ways therapists are taught to interview could be adapted to help beginning qualitative researchers learn interviewing skills as well. In this paper, three sets of exercises are presented which can be employed in the training of qualitative research interviewers. This article is available in The Qualitative Report: http://nsuworks.nova.edu/tqr/vol3/iss2/5 Practicing Qualitative Research Interviewing Exercises: Lessons from Family Therapy by Ronald J. Chenail The Qualitative Report, Volume 3, Number 2, July, 1997
The Dynamics of α-Synuclein at the Nerve Terminal

Publisher Summary This chapter discusses the underlying dynamics of α-synuclein at the nerve terminal. α-synuclein fibrils are found in abundance in Lewy bodies, a cardinal pathological lesion found in most cases of Parkinson's disease (PD). α-synuclein can adopt multiple structural conformations depending on its environment, some of which are capable of converting into key intermediates in the assembly of Lewy bodies. Controlling the appearance of these pathogenic intermediates may prevent or at least slow down PD. Under normal circumstances, α-synuclein interacts with synaptic vesicle membranes, localizing to the nerve terminal where it has been proposed to regulate neurotransmitter release. Upon membrane binding, α-synuclein undergoes a major conformational change, from relatively unstructured to highly α-helical. Neuronal activity induces the dissociation of the protein from synaptic vesicle membranes and its dispersion from the synapse. The link between membrane association and conformation indicates that the dynamics of α-synuclein probably has an important role in the pathogenesis of PD. This chapter, while explaining the dynamics of α-synuclein, also elaborates in detail the membrane binding in vitro as well as the membrane interactions in vivo.
Insulin-dependent phosphorylation of GTP-binding proteins in phospholipid vesicles.

The involvement of GTP-binding proteins (G proteins) in insulin action has been investigated in an in vitro system. Insulin receptors that have been purified by wheat germ lectin chromatography and either tyrosine-agarose chromatography, sucrose density centrifugation, or insulin-Sepharose chromatography have been co-inserted into phospholipid vesicles with different purified G proteins. The results of these studies indicate that a specific insulin-promoted phosphorylation of two G proteins, Go and Gi, can occur in these phospholipid vesicles. Bovine retinal transducin is a poor substitute for Go and Gi, being only weakly phosphorylated by the insulin receptor, and bovine brain Gs is not a substrate. The phosphorylation of Gi and Go occurs primarily on the alpha-subunits. Under optimal conditions, about one alpha o- or alpha i-subunit is phosphorylated on a tyrosine residue for every two beta-subunits of the insulin receptor, suggesting a 1:1 interaction between these G proteins and the heterotetrameric (alpha 2 beta 2) insulin receptor molecular. The inactive (GDP-bound) form of the alpha-subunits appears to be the preferred substrate, with the phosphorylation being significantly reduced in alpha o and alpha i upon the binding of guanosine 5′-O-thiotriphosphate (GTP gamma S) and completely eliminated in the pure alpha-GTP gamma S complex of transducin. The Gi and Go proteins also cause an enhancement of the insulin-stimulated receptor autophosphorylation. This enhancement is a reflection of an increased incorporation of the insulin receptor into lipid vesicles which is induced by these G proteins. Taken together these results provide evidence for the interactions of G proteins with the insulin receptor in a lipid milieu.
Limestone Barriers to Neutralize Acidic Streams

Water samples were taken for analysis and measurements were made to determine the effect of each installation on water quality at four prototype limestone barriers that had been constructed to neutralize acidic streams. The pH of stream water was increased by up to 3 pH units at low streamflow, to pH 7 or above. This demonstrates that limestone barriers are capable of renovating acidic streams to the point that normal aquatic life can be restored, rendering the stream water suitable for a number of uses that are otherwise precluded. A mathematical model of limestone barriers was constructed, based on hydraulic laws and on the chemical kinetics of the rate limiting reactions between crushed limestone and acidic water. Model predictions matched the observed performance of the barriers. A procedure was developed to determine the design of a barrier of crushed limestone to neutralize a given streamflow.
Estimating the Parameters of a Linear Function of a Random Variable

Abstract : Suppose we have a sample of independent observations which are values of a linear function of a random variable, and we wish to find maximum likelihood estimators for the two parameters of the linear function. If the support of the random variable is the whole real axis, the maximum likelihood estimators can be found by the usual methods; in other cases restricted maximization techniques must be used. We restricted attention to the cases in which the support is an infinite interval or a lattice and the density of the random variable is non-increasing over the support. Special attention is given to the exponential and geometric distributions. If the parameter of the distribution is also unknown, its maximum likelihood estimator can also be obtained, when the support of the random variable is a lattice. (Author)
Succession Planning in the Library: Developing Leaders, Managing Change by Paula M. Singer and Gail Griffith

Recent published research reveals that mature workers are the fastest-growing segment of the labor market. Within the next 10 years, the number of workers over the age of 55 is expected to double. ...
Using Digital History for Positive Change in Social Studies Education

AbstractThis paper reports on the Digital Historical Inquiry Project, an initiative for developing activities and programs that enable preservice and inservice social studies teachers to learn the methods of digital historical inquiry and implement those methods in their teaching experiences. At one of the project sites, San Diego State University social studies teacher education students are creating pedagogical historical resources called Web Inquiry Projects for using digital primary historical source materials. At another site, Georgia State University preservice and inservice teachers are developing original local digital historical resources for teachers and students to use in their classrooms. Both of these projects are presented as examples of how technology can be lever-aged to enhance social studies instruction.
Systematic Analysis of Climatic Model Sensitivity to Parameters and Processes

A demonstration is presented of the adjoint method of sensitivity analysis on a radiative-convective climate model with a diurnal cycle. A single adjoint calculation, which requires about the same computation time as the original model, suffices to calculate sensitivities of average surface air temperature to all 312 model parameters. The sensitivities accurately predict the effect on average surface air temperature of small variations in the model parameters. Relative sensitivities rank the importance of all the parameters, the most important parameters being those that characterize solar radiation and determine transmission functions. The uncertainties in the model results are expressed formally in terms of all the sensitivities and parameter covariances. For this model, a 10% standard deviation in surface albedo causes the increase in average surface air temperature after doubling CO/sub 2/ to have a standard deviation of 0.24/sup 0/K about the expected value of 1.66/sup 0/K. For results that cannot readily be compared with observation (for example, the results of a CO/sub 2/ doubling experiment), this method of uncertainty analysis is the only systematic way to estimate the reliability of model results. This estimate of the reliability, though, will only be realistic if all important physical processes and feedback mechanisms havemore » been included, however, crudely, in the model. The radiative-convective model contains complex on-off nonlinear processes of the type found in general circulation models. Therefore, the fact that the adjoint method works successfully and efficiently for the radiative-convective model provides valuable information about subsequent application of the method to general circulation models.« less
Learning and collaboration across generations in a community

We report on the activities and outcomes of two workshops in which middle school students and senior citizens explored, designed, and constructed visual simulations related to community issues. The workshops are part of a larger project, in which we are studying the effects of community-related programming projects and discussion on residents' computer literacy and community involvement. We describe the interactions among participants of varying age, and the simulations that they designed and built. We also discuss the influence of age on participants' reactions to the workshop activities, and consider what implications these findings have for our goal of building and maintaining a cross-generation learning community.
Pediatric patients' orthodontic treatment need, quality of life, and smiling patterns -- an analysis of patient, parent, and provider responses.

Objectives: The objectives of this study is to explore the relationship between pediatric patients' orthodontic treatment need, the patients' assessments of their smile-related quality of life (QoL), their parents' proxy assessment of their child's QoL and own assessments of their child's smile, and the patients' objectively assessed smiling patterns. Methods: Survey data were collected from 102 patients (53 boys/49 girls; age range: 9–13 years) and their parents. Orthodontic treatment need was assessed with the Index of Complexity, Outcome, and Need (ICON). Smiling patterns were determined by videotaping patients' smiles while they watched a cartoon. Thirty predetermined sections of these tapes were then assessed by two independent raters to measure the patients' smiling patterns. Results: The aesthetic component and total ICON scores correlated with the patients' smile-related QoL (r = 0.25; P = 0.014/r = 0.23; P = 0.024), parental proxy assessments of the child's smile-related QoL (r = 0.29; P = 0.004/r = 0.26; P = 0.009), the parents' own assessments of their child's smile (r = 0.32; P = 0.002/r = 0.29; P = 0.005), and the number of negative adjectives chosen by the parents to describe their child's smile (r = 0.32; P = 0.002/r = 0.30; P = 0.004). Although the smiling patterns were correlated with the patients' smile-related QoL responses (height of smile: r = 0.29; P = 0.005/number of teeth shown: r = 0.30; P = 0.004), the ICON scores were not correlated with the patients' smiling patterns. Conclusions: Objectively assessed orthodontic treatment need correlates with the patients' and parents' assessments of the child's smile-related QoL scores. However, while objective smiling patterns are related with the patients' smile-related QoL, they are not correlated with the patients' orthodontic treatment need.
Late-Life Depression and Antidepressants

Depression in late life is a disorder that may have disastrous consequences for an individual’s mental and physical health, quality of life, and even take life itself. Many older individuals have suffered from depression in earlier life, and their experience of late-life episodes may confirm a sense of hopelessness and uselessness of this last phase of life. Unlike Erikson’s 1 definition of this final stage of identity in life in which an individual can review and feel accomplishment in past experience, depression may feel like disintegration, crumbling identity, and a wish for an end to all suffering. Late-life depression is potentially a lethal disease. Suicide rates are highest among the elderly 2 and highest in locations where there are more elderly people (e.g., warm resort areas). It is fortunate therefore that modern medicine and psychiatry have techniques for treating depression in late life, and three articles in this issue provide important data regarding treatment with antidepressant medications. Before examining these articles, however, it may be useful to review what we know about late-life depression and its pharmacologic treatment. First, let us examine the diagnosis and prevalence of late-life depression. In many cases, the symptom profile of an elderly depressed individual is not markedly differentfromyoungersufferers.Theretendtobemore physical symptoms and more feelings of decreased self-esteem, worthlessness, and ruminative thinking 3
Dyadic death: Murder-suicide.

Twenty homicide-suicides, drawn from death records of three major eastern United States cities, were analyzed in comparison to prior studies and samples of homicide offenders and suicide victims. Results indicated a lower incidence for this event than reported previously and several distinguishing characteristics of the murderer who subsequently commits suicide. Two primary types, from the perspective of ego fusion, are discussed.
Mass screening for retrocochlear disorders.

In their article, “Mass Screening for Retrocochlear Disorders: Low-Field (0.2-Tesla) versus High-Field (1.5-T) MR Imaging,” Dr Dubrulle and his associates ask whether low-field-strength open T1-weighted spin-echo contrast-enhanced MR images of the cerebellopontine angle (CPA) and internal
Shifting Paradigms: Redesigning a Principal Preparation Program's Curriculum:

The purpose of this paper is to describe Auburn University's story of developing an innovative field-based master's level principal preparation program. Our goal was to align the program's curricul...
Epidemiologic evidence for uterine growth factors in the pathogenesis of ovarian cancer.

Abstract To examine the association between ovarian cancer and prior hysterectomy or tubal ligation in light of various interpretations, we combined data from two previously conducted case-control studies of ovarian cancer. This included 450 women with histologically verified epithelial ovarian cancer and 454 age-matched women from the general population for whom data on prior pelvic surgery were available to estimate exposure odds ratios. Overall there was a nonsignificant deficit of case patients who had had a hysterectomy or tubal ligation (odds ratio (OR) = 0.9; 95% confidence interval (CI), 0.6 to 1.3). A protective effect of prior hysterectomy or tubal ligation was more apparent among women who had the surgery 20 or more years previously (OR = 0.6; 95% CI, 0.3 to 1,1), women who had not used talc in their hygiene (OR = 0.6; 95% CI, 0.4 to 1.0), and women with mucinous tumors of the ovary (OR = 0.3; 95% CI, 0.1 to 1.0). Although these data do not clearly establish the validity of or mechanisms for an association between prior pelvic surgery and ovarian cancer, we speculate that such an association exists and may be mediated through absent or reduced uterine growth factors that reach the ovaries through the uteroovarian circulation, with mucinous tumors most dependent on such factors.
Growth hormone decreases visceral fat and improves cardiovascular risk markers in women with hypopituitarism: a randomized, placebo-controlled study.

Context: Data regarding gender-specific efficacy of GH on critical endpoints are lacking. There are no randomized, placebo-controlled studies of physiological GH therapy solely in women. Objective: Our objective was to determine the effects of physiological GH replacement on cardiovascular risk markers and body composition in women with GH deficiency (GHD). Design: This was a 6-month, randomized, placebo-controlled, double-blind study. Setting: The study was conducted at the General Clinical Research Center. Study Participants: 43 women with GHD due to hypopituitarism were included in the study. Intervention: Study participants were randomized to receive GH (goal mid-normal serum IGF-1) or placebo. Main Outcome Measures: Cardiovascular risk markers, including high-sensitivity C-reactive protein, tissue plasminogen activator, and body composition, including visceral adipose tissue by cross-sectional computed tomography, were measured. Results: Mean daily GH dose was 0.67 mg. The mean IGF-1 sd score increas...
Disciplinary Referrals for Culturally and Linguistically Diverse Students with and without Disabilities: Patterns Resulting from School-Wide Positive Behavior Support.

The goal of our study was to examine if school-wide positive behavior support implementation was associated with reductions in the discipline gap. We provided outcomes from descriptive and preliminary statistical analyses of three years of office discipline referral data from elementary schools engaged in school-wide positive behavior support implementation and not engaged in school-wide positive behavior support implementation. The percent of students enrolled was compared to the percent of students with office discipline referrals within each racial-ethnic category. The percent of students with office discipline referrals and individualized education plans was compared across racial-ethnic categories. Outcomes indicated that the discipline gap was present in schools engaged in school-wide positive behavior support implementation as well as schools not engaged in implementation with African American students over-represented among students with office discipline referrals. In schools engaged in school-wi...
The applicability of Coulomb’s friction law to drawbeads in sheet metal forming

During sheet metal forming on a doubleaction toggle press, drawbeads on the die binder supply a restraining force which controls the flow of sheet metal into the die. To study the restraining force and the related binder holddown force, an apparatus was built which simulates a drawbead. The apparatus can separate the restraining force into its bending deformation and friction components. From experimental measurements of the appropriate forces a coefficient of friction for drawbeads may be obtained. A comparison of experimental and calculated friction forces shows that Coulomb’s Law (a constant coefficient of friction) satisfactorily represents the friction force in low and medium load ranges. However, Coulomb’s Law breaks down at higher loads. The load at which breakdown occurs depends on interactions among many variables including sheet metal material, lubricant, and surface roughness.
Supervision for Preparation and Practice of School Counselors: Pathways to Excellence

In this article, the importance of clinical supervision for school counselors is examined in terms of prior literature and the school counseling context. Standards relative to supervision are presented, followed by an overview of each article in the special section of the Counselor Education and Supervision journal (Vol. 45, No. 4, June 2006).
Studies of the solvent extraction of cadmium and silver dithizonates

Abstract An extensive study was made of the solvent extraction of cadmium and silver dithizonates into chloroform A few extractions of silver dithizonate were made into carbon tetrachloride. In most cases extraction curves of PH versus % metal extracted were obtained and reported in terms of the PH of 50% extraction. The shift of the extraction curves to higher PH values due to the effect of ions in the aqueous phase which complex with the cadmium or silver ions was investigated An equation was developed which would predict the PH of 50% extraction for the extraction from the solutions containing these complexing ions The effects of chloride, bromide and iodide ions on the extraction of cadmium and the effects of chloride, bromide, iodide, thiocyanate and thiosulfate ions on the extraction of silver. Extraction constants for the various extractions were determined.
Polarized 3He Neutron Spin Filter Development and Application at Indiana University and NIST

Abstract Neutron spin filters based on polarized 3 He promise to significantly expand the range of applications of polarized neutron scattering, particularly for experiments with divergent beams. At NIST and at Indiana University, we are pursuing both methods of polarizing 3 He by optical pumping: the metastability exchange method, and spin exchange with optically pumped Rb. The status of the respective apparatus and application to small angle neutron scattering (SANS) at the National Institute of Standards and Technology (NIST) and neutron reflectometry at the Intense Pulsed Neutron Source (IPNS) at Argonne National Laboratory are discussed.
Susceptibilities of different‐sized ciliates to direct suppression by small and large cladocerans

SUMMARY 1 Laboratory experiments compared the susceptibilities of six ciliates and the rotifer Keratella cochlearis to predation and interference from Daphnia pulex and Bosmina longirostris. 2 Susceptibilities of the ciliates to D. pulex were similar to or less than that of the rotifer, and decreased with increasing ciliate size. Most ciliates were just as susceptible to B. longirostris as to the much larger D. pulex. The jumping response of the oligotrich Strobilidium gyrans appeared to be an effective defence against B. longirostris. 3 Clearance rates of B. longirostris and D. pulex on different ciliate species at a density of 1,3 ciliates ml−1 ranged from 1–30 to 5–24ml ind.−1 day−1, respectively. In natural plankton communities, cladocerans could impose high mortality rates on ciliates and shift the size structure of ciliate assemblages towards larger and less susceptible species.
Calculating lens dose and surface dose rates from 90Sr ophthalmic applicators using Monte Carlo modeling.

Using a 90 Sr applicator for brachytherapy for the reduction of recurrence rates after pterygium excisions has been an effective therapeutic procedure. Accurate knowledge of the dose being applied to the affected area on the sclera has been lacking, and for decades inaccurate estimates for lens dose have thus been made. Small errors in the assumptions which are required to make these estimates lead to dose rates changing exponentially because of the attenuation of beta particles.Monte Carlo simulations have been used to evaluate the assumptions that are now being used for the calculation of the surface dose rate and the corresponding determination of lens dose. For an ideal 90 Sr applicator, results from this study indicate dose rates to the most radiosensitive areas of the lens ranging from 8.8 to 15.5 cGy/s. This range is based on different eye dimensions that ultimately corresponds to a range in distance between the applicator surface and the germinative epithelium of the lens of 2–3 mm. Furthermore, the conventional 200 cGy threshold for whole lens cataractogenesis is questioned for predicting complications from scleral brachytherapy. The dose to the germinative epithelium should be used for studying radiocataractogenesis.
Project‐Level Reuse Factors: Drivers for Variation within Software Development Environments*

Systematic reuse can dramatically improve software development productivity and quality even though a software reuse methodology may require substantial investments. Some projects may fail to achieve the targeted amounts of reuse within organizations that are overall successful in employing reuse. To explain such variation, this research explores the effects of project-level factors in the success of software reuse. A model that relates project factors to project reuse success is developed using an information-rich case study approach. The results are based on the insights obtained in a nominal group technique session, triangulated with structured interviews and comparative case studies. Success factors identified by the study relate to client influence, project culture, project attributes, and developer reuse experience. An organization that can successfully identify the factors affecting potential software reuse will be able to better target investments for the improvement of its reuse methodology and thus positively affect its software development productivity and quality.
Direct Activation of Ribosome-Associated Double-Stranded RNA-Dependent Protein Kinase (PKR) by Deoxynivalenol, Anisomycin and Ricin: A New Model for Ribotoxic Stress Response Induction

Double-stranded RNA (dsRNA)-activated protein kinase (PKR) is a critical upstream mediator of the ribotoxic stress response (RSR) to the trichothecene deoxynivalenol (DON) and other translational inhibitors. Here, we employed HeLa cell lysates to: (1) characterize PKR’s interactions with the ribosome and ribosomal RNA (rRNA); (2) demonstrate cell-free activation of ribosomal-associated PKR and (3) integrate these findings in a unified model for RSR. Robust PKR-dependent RSR was initially confirmed in intact cells. PKR basally associated with 40S, 60S, 80S and polysome fractions at molar ratios of 7, 2, 23 and 3, respectively. Treatment of ATP-containing HeLa lysates with DON or the ribotoxins anisomycin and ricin concentration-dependently elicited phosphorylation of PKR and its substrate eIF2α. These phosphorylations could be blocked by PKR inhibitors. rRNA immunoprecipitation (RNA-IP) of HeLa lysates with PKR-specific antibody and sequencing revealed that in the presence of DON or not, the kinase associated with numerous discrete sites on both the 18S and 28S rRNA molecules, a number of which contained double-stranded hairpins. These findings are consistent with a sentinel model whereby multiple PKR molecules basally associate with the ribosome positioning them to respond to ribotoxin-induced alterations in rRNA structure by dimerizing, autoactivating and, ultimately, evoking RSR.
Electrochemically modulated transport through a conducting polymer membrane

Abstract The barrier properties of a poly(aniline) membrane may be tuned by electrochemical control of the polymer’s oxidation state. We have exploited this behavior to electrochemically modulate the permeation of two probe molecules of differing charge through a supported poly(aniline) membrane. The trans-membrane flux was measured for neutrally charged phenol and negatively charged 4-hydroxybezenesulfonate as a function of the polymer oxidation state, which was controlled by stepping the potential applied to a poly(aniline) film from a reducing potential to increasingly more oxidizing values. The fluxes of phenol and of 4-hydroxybezenesulfonate were enhanced when the polymer was poised in the half-oxidized, emeraldine state as compared to that of the reduced, leucoemeraldine state. Additional film oxidation to the pernigraniline state produced an enhanced flux of 4-hydroxybenzenesulfonate over phenol. The flux responses for these probe molecules are explained through a combination of oxidation-induced film swelling and electrostatic effects due to variable film charge. At high membrane potentials, film modulation was disrupted by poly(aniline) hydrolysis and decomposition. This work demonstrates that the permeation of a supported poly(aniline) membrane may be modified electrochemically to produce controllable barrier properties.
The Making of a National Icon: Commemorating Nie Er, 1935–1949

The choice of his song, “March of the Volunteers,” as the PRC’s national anthem catapulted Nie Er to fame, but the groundwork for his iconic status began soon after his death in 1935. This article examines the relationship between the politics of commemoration and the development of sonic nationalism, in both its textual and performative dimensions, between 1935 and 1949. I argue that Nie’s mass songs both represented and served as media for the expression of a class-inflected nationalism. Leftist cultural workers highlighted Nie’s music and compositional method to advocate “popularization” and to reject the popular music associated with Li Jinhui and “academy” music informed by the Western musical tradition. Nie’s iconic status derived from a combination of Communist cultural policies, grassroots mobilization in the form of the national salvation choral movement, and the international reception accorded to his “March of the Volunteers” as mediated by Liu Liangmo and Paul Robeson.
Turbulence Control in Wall-Bounded Flows by Spanwise Oscillations

The feasibility of control of wall turbulence by high frequency spanwise oscillations is investigated by direct numerical simulations of a planar turbulent channel flow subjected either to an oscillatory spanwise crossflow or to the spanwise oscillatory motion of one of the channel walls. Periods of oscillation, T osc. + = T osc. U τ 2 /v, ranging from 25 to 500 were studied. For 25 < T osc. + < 200 production of turbulence is suppressed. The most effective suppression of turbulence occurs at T osc + = 100, for which the overall turbulence production is reduced by 62% compared to the unperturbed channel and sustained turbulent drag reductions of 40% are obtained. The suppression of turbulence is due to a continual shift of the near wall streamwise vortices relative to the wall layer streaks, which in turn leads to a widening, merging and weakening of the wall layer streaks and an overall reduction in the turbulence production. The turbulence suppression mechanism observed in these studies opens up new possibilities for effective control of turbulence in wall-bounded flows.
Going beyond the facts: Young children extend knowledge by integrating episodes

The major question posed in this research was whether 4- and 6-year-olds productively extend their knowledge by integrating information acquired in separate episodes. The vehicle was a read-aloud activity during which children were presented with a novel fact in each of two passages. In Experiment 1, both age groups showed evidence of integration between the passages. For the 6-year-olds, the evidence came in the form of responses to open-ended questions. The 4-year-olds recognized the correct answers but did not generate them in the open-ended question format. The 6-year-olds who generated the correct answers also were likely to recall both of the individual facts presented in the passages. In Experiment 2, we tested whether the 4-year-olds' integration performance would improve if their memory for the individual facts improved. Extra exposure to the individual facts resulted in higher levels of integration performance in both recall and recognition testing. The roles of memory and other potential sources of age-related differences in integration performance are discussed.
Surprises of genetic engineering: a possible model of polyglucosan body disease.

Background: The authors previously reported the generation of a knockout mouse model of Pompe disease caused by the inherited deficiency of lysosomal acid alpha-glucosidase (GAA). The disorder in the knockout mice (GAA−/−) resembles the human disease closely, except that the clinical symptoms develop late relative to the lifespan of the animals. In an attempt to accelerate the course of the disease in the knockouts, the authors increased the level of cytoplasmic glycogen by overexpressing glycogen synthase (GSase) or GlutI glucose transporter. Methods: GAA−/− mice were crossed to transgenic mice overexpressing GSase or GlutI in skeletal muscle. Results: Both transgenics on a GAA knockout background (GS/GAA−/− and GlutI/GAA−/−) developed a severe muscle wasting disorder with an early age at onset. This finding, however, is not the major focus of the study. Unexpectedly, the mice bearing the GSase transgene, but not those bearing the GlutI transgene, accumulated structurally abnormal polysaccharide (polyglucosan) similar to that observed in patients with Lafora disease, glycogenosis type IV, and glycogenosis type VII. Ultrastructurally, the periodic acid-Schiff (PAS)-positive polysaccharide inclusions were composed of short, amorphous, irregular branching filaments indistinguishable from classic polyglucosan bodies. The authors show here that increased level of GSase in the presence of normal glycogen branching enzyme (GBE) activity leads to polyglucosan accumulation. The authors have further shown that inactivation of lysosomal acid alpha-glucosidase in the knockout mice does not contribute to the process of polyglucosan formation. Conclusions: An imbalance between GSase and GBE activities is proposed as the mechanism involved in the production of polyglucosan bodies. The authors may have inadvertently created a “muscle polyglucosan disease” by simulating the mechanism for polyglucosan formation.
Ironsilicon bond cleavage in dicarbonyl(ν5-cyclopentadienyl)(trimethylsilyl)iron using tetrabutylammonium fluoride

Dicarbonyl(η5-cyclopentadienyl)(trimethylsilyl)iron (1) was found to react with a 1 M solution of tetrabutylammonium fluoride (2) in tetrahydrofuran at 25°C to give dicarbonyl(η5-cyclopentadienyl)iron anion (5). The anion generated under these conditions was trapped with electrophiles (RX) to give 45–89% yields of neutral dicarbonyl(η5-cyclopentadienyl)-alkyl, -allyl, -acyl-iron compounds and the ethylene cation. Tetrabutylammonium hydroxide also can be used in this reaction. Evidence indicates that fluoride ion instead of hydroxide attacks the silicon when tetrabutylammonium fluoride is used since fluorotrimethylsilane can be detected in the reaction product. Tetrabutylammonium fluoride and hydroxide quantitatively liberate styrene from dicarbonyl(η5-cyclopentadienyl)(η2-styrene)iron tetrafluoroborate, producing bis[dicarbonyl(η2-cyclopentadienyl)iron].
Recognition of Neighbors' Duets By Stripe-Backed Wrens Campylorhynchus Nuchalis

Stable groups of stripe-backed wrens Campylorhynchus nuchalis occupy exclusive territories and perform stereotyped duets and choruses in the same contexts in which many individually territorial passerines sing. When duets are broadcast from a speaker just inside a group's territorial boundary, the principal pair in the subject group reacts much more strongly to playbacks of strangers' duets than neighbors' duets. In addition, they respond slightly more intensely to a neighbor's duet on the wrong side of the subject group's territory than to the same duet on the correct side of the territory. These results indicate that stripe-backed wrens can differentiate neighboring groups' duets and associate each with a customary direction. The duets of this species have nearly the same effects on territorial residents as do the advertising songs of passerines with individual territories.
Products of ACRIN Spaces

. Products of spaces X and Y with the property that every continuous regular image of the product is normal are investigated, and the conclusion that there are fewer such spaces than might be suspected arrived at. In fact, either X and Y are Lindelof, or X is countably compact, Y is compact, and t(Y) is small. In a first effort to find a partial converse to the second case, Nogura's result on the normality of the product of an ordinal with a compact space is extended.
Drawing lines in the sand: the boundaries of the HIV pandemic in perspective.

To understand the danger of creating artificial divisions between those who are HIV-infected and those who are not it is helpful to take a closer look at the underlying causes of HIV spread among populations. The author asks and answers the following questions: Do differences in sexual behavior explain differences in the epidemic? Do Sexually Transmitted Diseases (STDs) and other chronic infections accelerate the epidemic? Does HIV-1 viral subtype matter? How important is male circumcision? How does the timing of HIV infection affect transmission dynamics in a population?
WiMAX performance at 4.9 GHz

Worldwide Interoperability for Microwave Access (referred to as WiMAX) is a MAC and physical layer wireless communications technology for outdoor broadband wireless coverage. In collaboration with the Clemson University Police Department, we have deployed an 802.16d WiMAX network that operates at 4.9 GHz at Clemson University. In this paper, we present the results from a performance analysis we have conducted of the WiMAX network. To the best of our knowledge the work reported in this paper is the first academic study of an operational 4.9 GHz WiMAX in which controlled experiments could be conducted. While neither the 4.9 GHz spectrum nor the current WiMAX profiles settings might be optimal for space or lunar communications, a study of WiMAX at any frequency is of value to both the aerospace industry and the research community. The WiMAX standard leaves key areas of the protocol, including packet scheduling, frame packing, and modulation/coding adaptation, unspecified. In order to accurately model and analyze WiMAX, realistic assumptions must be used. Because WiMAX systems have not been widely studied, there is a disconnect between theoretical WiMAX systems and real-world deployed systems. This motivates the research presented in this paper. Using knowledge of the equipment's implementation choices, we derive theoretical application throughput for both TCP and UDP protocols and correlate expected results with empirical results. We also summarize results from a coverage analysis of the system. The combined results lead to an important point: although equipment implementation choices contribute to the achieved performance of WiMAX, the physics surrounding 4.9 GHz RF propagation will likely have the most significant impact on system performance.12
Integration of Off-Track Sonic Boom Analysis in Conceptual Design of Supersonic Aircraft

A highly desired capability for the conceptual design of aircraft is the ability to rapidly and accurately evaluate new concepts to avoid adverse trade decisions that may hinder the development process in the later stages of design. Evaluating the robustness of new low-boom concepts is important for the conceptual design of supersonic aircraft. Here, robustness means that the aircraft configuration has a low-boom ground signature at both under- and off-track locations. An integrated process for off-track boom analysis is developed to facilitate the design of robust low-boom supersonic aircraft. The integrated off-track analysis can also be used to study the sonic boom impact and to plan future flight trajectories where flight conditions and ground elevation might have a significant effect on ground signatures. The key enabler for off-track sonic boom analysis is accurate computational fluid dynamics (CFD) solutions for off-body pressure distributions. To ensure the numerical accuracy of the off-body pressure distributions, a mesh study is performed with Cart3D to determine the mesh requirements for off- body CFD analysis and comparisons are made between the Cart3D and USM3D results. The variations in ground signatures that result from changes in the initial location of the near-field waveform are also examined. Finally, a complete under- and off-track sonic boom analysis is presented for two distinct supersonic concepts to demonstrate the capability of the integrated analysis process.
Effect of Vibration on the Liquid Water Transport of PEM Fuel Cells

The objective of this research is to analyze the effects of vibration on the performance of hydrogen PEM fuel cells. It has been reported that if the liquid water transport across the gas diffusion layer (GDL) changes, so does the overall cell performance. Since many fuel cells operate under a vibrating environment –as in the case of automotive applications, this may influence the liquid water concentration across the GDL at different current densities, affecting the overall fuel cell performance. The problem was developed in two main steps. First, the basis for an analytical model was established using current models for water transport in porous media. Then, a series of experiments were carried, monitoring the performance of the fuel cell for different parameters of oscillation. For sinusoidal vibration at 10, 20 and 50Hz (2 g of magnitude), a decrease in the fuel cell performance by 2.2%, 1.1% and 1.3% was recorded when compared to operation at no vibration respectively. For 5 g of magnitude, the fuel cell reported a drop of 5.8% at 50 Hz, whereas at 20 Hz the performance increased by 1.3%. Although more extensive experimentation is needed to identify a relationship between magnitude and frequency of vibration affecting the performance of the fuel cell as well as a throughout examination of the liquid water formation in the cathode, this study shows that sinusoidal vibration, overall, affects the performance of PEM fuel cells.Copyright © 2009 by ASME
The Hudson Shelf Valley: Its role in shelf sediment transport

Abstract Freeland, G.L., Stanley, D.J., Swift, D.J.P. and Lambert, D.N., 1981. The Hudson Shelf Valley: its role in shelf sediment transport. Mar. Geol., 42: 399-427. The Hudson Shelf Valley was deeply incised by Pleistocene lowstands of the sea. During the Holocene transgression, fluvial, estuarine, and estuary-mouth depositional environments were displaced landward, and sedimentation in these environments partially filled the valley. Holocene sediment thickness in the seaward half of the valley is about the same as on the shelf to either side, but in the landward half of the valley, 22 m of sediment is present versus 5-10 m on the adjacent shelf. Sediment volume calculations in the upper shelf valley show that there is about three times the infill volume east of the thalweg as compared to the infill to the west. This configuration indicates that the valley has served as a sediment trap and records the westward migration of the thalweg during the Holocene. Most of the infill was the result of littoral drift which transported sand westward along the south shore of Long Island during the Holocene transgression. Modern sediment transport, as calculated from current-meter observations and inferred from bedform observations, is mainly south westward, along the regional trend of the isobaths and across the shelf valley. Therefore, infill on the eastern side of the shelf valley is continuing at present. Observations of the regional distribution of sediment types indicate that the asymmetrical valley fill is part of a pattern of bottom response to flow. The former drainage divides on both sides of the shelf valley are surfaced by coarse lag deposits on slopes facing northeast, into the direction from which the major storm flows come, while the down-current sides are mantled with fine sand.