cssi/SciSciGPT-SciSciNet huggingface dataset:
Mechanically reliable hybrid organosilicate glasses for advanced interconnects

We explore the structure–property relationships in hybrid organosilicate glasses that form a special class of materials for use in advanced interconnects to improve their mechanical reliability by exploiting the structural characteristics most effectively. Our results show that hybrid organosilicate glasses that are hyperconnected and derived from organic linkers with optimal molecular geometry lead to exceptional elastic and fracture properties. Using molecular dynamics simulations and the min-cut algorithm that is based on a novel graph theory approach, we demonstrate the choice of hyperconnected and cyclic planar organic linkers, such as the 1,3,5-benzene ring, significantly increases the bulk modulus and total fracture bond density, which is directly correlated with fracture energy.
Contemporary Mortality Rate and Outcomes in Nonagenarians Undergoing Primary Total Hip Arthroplasty

Abstract Background Nonagenarians (90-99 years) have experienced the fastest percent growth in primary THA utilization recently. However, there are limited data on this population. This study aimed to determine the mortality rate, implant survivorship, clinical outcomes, and complications of primary THAs in nonagenarians. Methods Our institutional total joint registry was used to identify 144 nonagenarians who underwent 149 primary THAs for osteoarthritis only between 1997 and 2017. The mean age was 92 years, with 63% being female. Mortality, revision, and reoperation were assessed using cumulative incidence with death as a competing risk and Cox regression methods. Clinical outcomes were assessed using Harris hip scores (HHSs). Cemented femoral components were used in 68%. The mean follow-up was 4 years. Results The mortality rates were 6%, 8%, 14%, and 49% at 90 days, 1 year, 2 years, and 5 years, respectively. The 5-year cumulative incidences of any revision and reoperation were 1% and 4%, respectively. The mean HHS improved significantly from 48 preoperatively to 76 at 5 years (P Conclusion Nonagenarians undergoing primary THA had substantial mortality rates at 90 days (6%) and 1 year (8%). While the cumulative incidence of any revision and reoperations were low at 5 years, the high complication rate is mostly due to periprosthetic fractures. Level of evidence Level IV, retrospective cohort.
A method for building low loss multi-layer wiring for superconducting microwave devices

Complex integrated circuits require multiple wiring layers. In complementary metal-oxide-semiconductor processing, these layers are robustly separated by amorphous dielectrics. These dielectrics would dominate energy loss in superconducting integrated circuits. Here, we describe a procedure that capitalizes on the structural benefits of inter-layer dielectrics during fabrication and mitigates the added loss. We use a deposited inter-layer dielectric throughout fabrication and then etch it away post-fabrication. This technique is compatible with foundry level processing and can be generalized to make many different forms of low-loss wiring. We use this technique to create freestanding aluminum vacuum gap crossovers (airbridges). We characterize the added capacitive loss of these airbridges by connecting ground planes over microwave frequency λ/4 coplanar waveguide resonators and measuring resonator loss. We measure a low power resonator loss of ∼3.9 × 10−8 per bridge, which is 100 times lower than that of dielectric supported bridges. We further characterize these airbridges as crossovers, control line jumpers, and as part of a coupling network in gmon and fluxmon qubits. We measure qubit characteristic lifetimes (T1s) in excess of 30 μs in gmon devices.
teach HOUSTON Alumni: Agents of Change in Secondary STEM Education

This chapter describes how the teachHOUSTON program, the University of Houston’s secondary STEM teacher preparation program developed strategic endeavors to build leadership capacity with the program’s alumni. Since teachHOUSTON’s conception in 2007, nearly 300 graduates have entered classrooms in high-needs school districts with an impressive 88% retention beyond five years. Graduates of the program are encouraged to present at national and local conferences, share resources with fellow STEM teachers, and, serve as mentors to their undergraduate peers. Moreover, through their efforts as trailblazing educators, alumni of the teachHOUSTON program have not only led based on existing and proposed school and district policies but have also introduced and advocated for new and innovative educational practices. Out of this advocacy, teachHOUSTON Alumni have created new agendas and areas of focus shifting in their work and in their roles from teacher leaders to agents of change. The chapter includes narratives from a teachHOUSTON alum and master teacher, along with the associate director, and faculty advisor of the program, all of whom worked in a collaborative partnership to spearhead the initiatives discussed. The authors are members of the Faculty Academy that has been designed to support and elevate their endeavors in teacher education. Because of the continued mentoring, networking, and advocacy provided through the Faculty Academy, teachHOUSTON faculty members, much like their graduates, are serving as agents of change for schools and districts.
A Protactile-Inspired Wearable Haptic Device for Capturing the Core Functions of Communication

In this article, a novel wearable haptic device, to be worn on the hand and forearm, is introduced. Using the modalities of vibration, pressure, and heat application, the device attempts to replicate four core components of communication. The four components - co-presence, phatic communication, back-channeling, and direction giving - are simulated through haptic profiles individually unique to a section or combined as an encompassing system of the device. This paper evaluates the performance of the device through three testing phases with sighted-hearing and DeafBlind individuals. Results indicate that a strong majority of the tested haptic profiles show statistical significance in replication between individuals. This article is unique in its collaboration with the protactile DeafBlind community, individuals who communicate solely through touch, by furthering understanding on how to generate intuitive tactile profiles in wearable haptic devices.
Refined pancreatobiliary UroVysion criteria and an approach for further optimization

Pancreatobiliary strictures are a common source of false negatives for malignancy detection. UroVysion is more sensitive than any other method but remains underutilized because of conflicting sensitivities and specificities due to a lack of standardized cutoff criteria and confusion in interpreting results in the context of primary sclerosing cholangitis. We set out to determine the sensitivities and specificities of UroVysion, brushing cytology, forceps biopsies, and fine needle aspiration (FNAs) for pancreatobiliary stricture malignancy detection. A retrospective review was performed of all biopsied pancreatobiliary strictures at our institution over 5 years. UroVysion was unquestionably the most sensitive method and all methods were highly specific. Sensitivity was highest while maintaining specificity when a malignant interpretation was limited to cases with 5+ cells with the same polysomic signal pattern and/or loss of one or both 9p21 signals. Only UroVysion detected the metastases and a neuroendocrine tumor. In reviewing and analyzing the signal patterns, we noticed trends according to location and diagnosis. Herein we describe our method for analyzing signal patterns and propose cutoff criteria based upon observations gleaned from such analysis.
Döhle bodies associated with uncomplicated pregnancy.

Fifteemi pregnamit womimen without complications, except iron deficiency, were selected for study and were closely followed as outpatients. These 15 patients included 5 primiparas and 10 niultiparas. Complete blood counts ( hemoglobin, hemnatocrit, total leukocyte count, and 100 cell differential ) were obtained at frequent intervals during pregnancy. The hemoglobin and hematocrit did not prove to be pertinent and will not be discussed. The number of D#{246}hle bodies present per 100 granuloc�’tes was recorded. A total leukocyte count and 100 cell differential was performrmed on each woman during active labor, at 30 minutes postpartumrm, at 4 days postpartumn and again 6 to 8 weeks later. The total leukocyte count was perfonmied on blood anticoagumlaed with EDTA. Unanticoagulated blood was umsed exclusively for the Wright-stained blood films; stained films fromrm blood anticoagumlated with EDTA, heparin and potassiumm oxalate were umnsatisfactory. Single blood films from 500 uncomplicated pregnant women were stained with Wright’s stain and examnined for D#{246}hle bodies. In some instances,blood filmus were stained with pyronin methyl-green and examnined. These500 women were representative of all stages of pregnancy and imp to 6 weeks postpartimmii. A control stumdy’ was performed on 500 clinically’ normal nonpregnant women.
Radio Occultation Data Processing at the COSMIC Data Analysis and Archival Center (CDAAC)

This paper gives an overview of the COSMIC Data Analysis and Archival Center (CDAAC) and presents initial results that were obtained from neutral atmospheric radio occultation data processing of the GPS/MET, CHAMP, and SAC-C datasets. Approximately 45 % of CHAMP and SAC-C retrieved radio occultation profiles reach below 1 km altitude, compared to only 35 % for GPS/MET. All missions exhibit a negative refractivity bias in the lower troposphere of nearly 1 % compared to NWP models. When constrained to the tropics, the CHAMP data show a negative refractivity bias of approximately 1.7 %, and only 20 % of occultation profiles reach 1 km. Current CDAAC LEO orbit determination for CHAMP agrees with JPL orbits at the 30 cm 3D root mean square level, which can result in temperature errors of about 0.3 degrees K at 30 km altitude.
On end-user computing productivity: Results of controlled experiments

Two important classes of end-users are: command level users, and end-user programmers. For each of these classes, controlled experiments have been conducted to measure their productivity. For command level users working with databases, our results indicate that they perform better when the logical data model used is consistent with their own views of reality. For end-user programmers writing programs in high-level procedural programming language, the quality of programs is generally low and no program development method clearly stands out in terms of quality; though writing programs directly without any preplanning is expeditious.
Cyanide-insensitive respiration. I. The steady states of skunk cabbage spadix and bean hypocotyl mitochondria.

Abstract The effect of aromatic hydroxamic acids on skunk cabbage spadix and bean hypocotyl mitochondrial respiration has been measured. It is shown that the measurement of rate versus inhibitor concentration leads to the determination of the fluxes of reducing equivalents in each of the two pathways of electron transport in both State 3 and State 4. The alternate, cyanide-insensitive pathway is regulated by the activity of the normal cytochrome pathway. The conclusions about fluxes in State 3 are confirmed by the quantitative effect of hydroxamic acids on the ADP to oxygen ratio. The alternate pathway may be involved in regulation of NADH levels in the plant cell and in heat production by the skunk cabbage spadix.
ADtrees for fast counting and for fast learning of association rules

The problem of discovering association rules in large databases has received considerable research attention. Much research has examined the exhaustive discovery of all association rules involving positive binary literals (e.g. Agrawal et al. 1996). Other research has concerned finding complex association rules for high-arity attributes such as CN2 (Clark and Niblett 1989). Complex association rules are capable of representing concepts such as "Purchased-Chips=True and PurchasedSoda=False and Area=NorthEast and CustomerType=Occasional ⇒ AgeRange=Young", but their generality comes with severe computational penalties (intractable numbers of preconditions can have large support). Here, we introduce new algorithms by which a sparse data structure called the ADtree, introduced in (Moore and Lee 1997), can accelerate the finding of complex association rules from large datasets. The ADtree uses the algebra of probability tables to cache a dataset's sufficient statistics within a tractable amount of memory. We first introduce a new ADtree algorithm for quickly counting the number of records that match a precondition. We then show how this can be used in accelerating exhaustive search for rules, and for accelerating CN2-type algorithms. Results are presented on a variety of datasets involving many records and attributes. Even taking the costs of initially building the ADtree into account, the computational speedups can be dramatic.
The evolution of myrmicine ants: phylogeny and biogeography of a hyperdiverse ant clade (Hymenoptera: Formicidae)

This study investigates the evolutionary history of a hyperdiverse clade, the ant subfamily Myrmicinae (Hymenoptera: Formicidae), based on analyses of a data matrix comprising 251 species and 11 nuclear gene fragments. Under both maximum likelihood and Bayesian methods of inference, we recover a robust phylogeny that reveals six major clades of Myrmicinae, here treated as newly defined tribes and occur- ring as a pectinate series: Myrmicini, Pogonomyrmecini trib.n., Stenammini, Solenop- sidini, Attini and Crematogastrini. Because we condense the former 25 myrmicine tribes into a new six-tribe scheme, membership in some tribes is now notably different, espe- cially regarding Attini. We demonstrate that the monotypic genus Ankylomyrma is nei- ther in the Myrmicinae nor even a member of the more inclusive formicoid clade - rather it is a poneroid ant, sister to the genus Tatuidris (Agroecomyrmecinae). Several species-rich myrmicine genera are shown to be nonmonophyletic, including Pogono- myrmex, Aphaenogaster, Messor, Monomorium, Pheidole, Temnothorax andTetramor- ium. We propose a number of generic synonymies to partially alleviate these problems (senior synonym listed first): Pheidole = Anisopheidole syn.n. = Machomyrma syn.n.; Temnothorax = Chalepoxenus syn.n. = Myrmoxenus syn.n. = Protomognathus syn.n.; Tetramorium = Rhoptromyrmex syn.n. = Anergates syn.n. = Teleutomyrmex syn.n. The genus Veromessor stat.r. is resurrected for the New World species previously placed in Messor; Syllophopsis stat.r. is resurrected from synonymy under Monomorium to contain the species in the hildebrandti group;Trichomyrmex stat.r. is resurrected from synonymy underMonomorium to contain the species in the scabriceps- anddestruc- tor-groups; and the monotypic genus Epelysidris stat.r. is reinstated for Monomorium brocha. Bayesian divergence dating indicates that the crown group Myrmicinae origi- nated about 98.6 Ma (95% highest probability density 87.9-109.6 Ma) but the six major clades are considerably younger, with age estimates ranging from 52.3 to 71.1 Ma. Although these and other suprageneric taxa arose mostly in the middle Eocene or earlier, a number of prominent, species-rich genera, such as Pheidole, Cephalotes, Strumigenys, Crematogaster andTetramorium, have estimated crown group origins in the late Eocene or Oligocene. Most myrmicine species diversity resides in the two sister clades, Attini and Crematogastrini, which are estimated to have originated and diversified extensively in the Neotropics and Paleotropics, respectively. The newly circumscribed Myrmicini is Holarctic in distribution, and ancestral range estimation suggests a Nearctic origin. The Pogonomyrmecini and Solenopsidini are reconstructed as being Neotropical in origin,
22 – CHEMICAL REACTIONS AS IRREVERSIBLE PROCESSES

This chapter examines the chemical reactions as irreversible processes. This undertaking leads to the introduction of a number of concepts that are required in the treatment of the thermodynamics of the steady state, such as the entropy production, energy dissipation, and energy retention functions. A consideration of chemical reactions as irreversible processes thus constitutes a natural transition from equilibrium to steady-state thermodynamics. This chapter discusses entropy produced in simultaneous and coupled reactions. These reactions are of great importance in biological processes.
A maternal factor, OZ-1, activates embryonic transcription of the Xenopus laevis GS17 gene.

We describe the identification of an enhancer sequence and a sequence-specific DNA-binding protein required for developmental expression of the Xenopus laevis GS17 gene. Using microinjection of recombinant plasmids into fertilized frog eggs, we have shown that a 14 base pair CT-rich sequence element, normally located about 700 bases upstream of the GS17 promoter, is sufficient to activate transcription of a heterologous reporter gene in gastrula stage embryos. This regulatory element has been called the OZ sequence. Sequences closely related to OZ are located in the promoter regions of several other genes expressed during Xenopus development. Extracts prepared from Xenopus embryos show the presence of a DNA-binding factor, OZ-1, that specifically recognizes the OZ sequence. Mutations within the OZ element that abolish OZ-1 binding also abolish enhancer activity. The OZ-1 factor contains at least two proteins of approximate M(r) 76 × 10(3) and 100 × 10(3). The sequence-specific binding activity accumulates during oogenesis and remains present at approximately constant levels throughout early development.
Prevalence of overweight in children and adolescents with attention deficit hyperactivity disorder and autism spectrum disorders: a chart review

The condition of obesity has become a significant public health problem in the United States. In children and adolescents, the prevalence of overweight has tripled in the last 20 years, with approximately 16.0% of children ages 6–19, and 10.3% of 2–5 year olds being considered overweight. Considerable research is underway to understand obesity in the general pediatric population, however little research is available on the prevalence of obesity in children with developmental disorders. The purpose of our study was to determine the prevalence of overweight among a clinical population of children diagnosed with attention deficit hyperactivity disorder (ADHD) and autism spectrum disorders (ASD). Retrospective chart review of 140 charts of children ages 3–18 years seen between 1992 and 2003 at a tertiary care clinic that specializes in the evaluation and treatment of children with developmental, behavioral, and cognitive disorders. Diagnostic, medical, and demographic information was extracted from the charts. Primary diagnoses of either ADHD or ASD were recorded, as was information on race/ethnicity, age, gender, height, and weight. Information was also collected on medications that the child was taking. Body mass index (BMI) was calculated from measures of height and weight recorded in the child's chart. The Center for Disease Control's BMI growth reference was used to determine an age- and gender-specific BMI z-score for the children. The prevalence of at-risk-for-overweight (BMI >85th%ile) and overweight (BMI > 95th%ile) was 29% and 17.3% respectively in children with ADHD. Although the prevalence appeared highest in the 2–5 year old group (42.9%ile), differences among age groups were not statistically significant. Prevalence did not differ between boys and girls or across age groups (all p > 0.05). For children with ASD, the overall prevalence of at-risk-for-overweight was 35.7% and prevalence of overweight was 19%. When compared to an age-matched reference population (NHANES 1999–2002), our estimates indicate that children with ADHD and with ASD have a prevalence of overweight that is similar to children in the general population.
A 21st-Century Humanities for the Community College.

This essay examines not only the role the humanities play in the community college curriculum but also how our approach to and understanding of the humanities must change. The defense of a 21st-century humanities has to begin in the experience of our students and not in the traditional canons of our disciplines.
Response of interferon-treated cells to diphtheria toxin.

It has been reported that treatment with homologous interferon of cells in culture interferes with the process of diphtheria intoxication in these cells. This report both confirms and extends this observation. The most sensitive indicator of diphtheria toxin action in cells, i.e., the inhibition of incorporation of labeled amino acids into protein, was employed, and human, mouse, and chicken interferon-cell systems were studied. Interferon treatment afforded a distinct, reproducible protection from the action of toxin, but in no case could total protection be shown. The “antitoxic” component is stable at pH 2, is species-specific, is not sedimented at 100,000 × g, and is trypsin-sensitive. Human cell preparations are heat-labile. Experiments with cell-free amino acid incorporation systems suggest that the “anti-toxic” effect of interferon is concentrated at the level of the cell membrane and subcellular components are not directly involved.
CRT-77 Gender Disparity in Young Patients Presenting with Symptomatic Premature Coronary Artery Disease Undergoing Percutaneous Coronary Intervention

There is paucity of data on the risk variables, clinical presentation and long term outcomes in patients presenting with symptomatic premature coronary artery disease (CAD). This study is done to understand the gender differences in risk factors for premature atherosclerosis and also evaluate the
Mutagenicity of bromate: Implications for cancer risk assessment

Abstract Bromate (BrO 3 − ) is a rodent carcinogen that is formed as a drinking water ozone disinfection by-product and also used in some food and consumer products. Therefore, bromate is subject to assessment for its risk to humans. Because the selection of an appropriate model for conducting quantitative cancer risk assessment is based upon an understanding of the chemical's mode-of-action, it is necessary to determine whether the chemical is a mutagenic carcinogen. We present a review of the available information concerning the weight-of-the-evidence that bromate is a mutagenic carcinogen. The evidence indicates that bromate is mutagenic and that this activity is mediated by the formation of oxidative damage to the DNA, thus resulting in chromosomal damage. Not only does bromate induce genetic damage in vitro, it is also demonstrated to induce mutations in the kidney of exposed rats. This is significant because the rat kidney is one of the target tissues for tumor induction. While it is clear that bromate can cause damage in the target tissue, it is not clear whether bromate is a mutagenic carcinogen, that is, whether the observed tumors result from a mutagenic mode-of-action. Further research is needed to clarify bromate's mode-of-action. However, in the absence of additional information, it is reasonable, based on an extensive database, to assume that bromate induces tumors via oxidative damage that causes chromosomal breakage.
Effect of omega-3 fatty acid oxidation products on the cellular and mitochondrial toxicity of BDE 47.

High levels of the flame retardant 2,2′,4,4′-tetrabromodiphenyl ether (BDE 47) have been detected in Pacific salmon sampled near urban areas, raising concern over the safety of salmon consumption. However, salmon fillets also contain the antioxidants eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), whose oxidation products induce cellular antioxidant responses. Because oxidative stress is a mechanism of BDE 47 toxicity, we hypothesized that oxidized EPA and DHA can ameliorate the cellular and mitochondrial toxicity of BDE 47. HepG2 cells were treated with a mixture of oxidized EPA and DHA (oxEPA/oxDHA) at a ratio relevant to salmon consumption (1.5/1 oxEPA/oxDHA) followed by exposure to 100 μM BDE 47. Pretreatment with oxEPA/oxDHA for 12 h prior to BDE 47 exposure prevented BDE 47-mediated depletion of glutathione, and increased expression of antioxidant response genes. oxEPA/oxDHA also reduced the level of reactive oxygen species production by BDE 47. The oxEPA/oxDHA antioxidant responses were associated with partial protection against BDE 47-induced loss of viability and also mitochondrial membrane potential. Mitochondrial electron transport system functional analysis revealed extensive inhibition of State 3 respiration and maximum respiratory capacity by BDE 47 were partially reversed by oxEPA/oxDHA. Our findings indicate that the antioxidant effects of oxEPA/oxDHA protect against short exposures to BDE 47, including a protective role of these compounds on maintaining cellular and mitochondrial function.
A simulation model for managing perennial grass pastures. Part I—structure of the model

Abstract A simulation model has been structured to facilitate stochastic evaluations of grazing management systems on perennial grass pastures. The output data, stored in a direct-access data set, can be used as input to statistical programs which will perform desired statistical analyses of the data. The model was originated to provide a practical method for estimating the effects of grazing frequency, duration, and grazing rate on the performance of grazing systems for perennial grass pastures. The model provides 32 different attributes for characterizing the performance of a grazing system.
The Evolution of Enhanced Surface Geometries for Nucleate Boiling

This paper surveys the evolution of special surface geometries that promote high-performance nucleate boiling. Early work by Jakob and Fritz in 1931 showed that emery paper roughening or machined grooves provided only temporary performance increase. However, this improvement dissipated after a few days to the flat surface value. There was little sustained interest in this unique, but apparently unuseful, phenomenon until the mid-1950s. During the period 1955-1965, supporting fundamental studies of the character and stability of nucleation sites provided a basis for renewed efforts to develop a high area density of stable, artificially formed nucleation sites whose performance does not deteriorate with time. Beginning in 1968 industrial research produced patented technology that achieved the long-sought goal. In 1980 at least six high-performance nucleate boiling surfaces were commercially available. The technology reported in this paper represents a dramatic advance in the field of heat transfer.
The global groundwater crisis

Groundwater depletion the world over poses a far greater threat to global water security than is currently acknowledged.
A Simulation Test Approach to the Evaluation of Nonlinear Optimization Algorithms

A simulation test methodology was developed to evaluate unconstrained nonlinear optimization computer algorithms. The test technique simulates problems optimization algorithms encounter in practice by employing a repertoire of problems representing various topographies (descending curved valleys, saddle points, ridges, etc.), dimensions, degrees of nonlinearity (e.g., linear to exponential) and minima, addressing them from various randomly generated initial approximations to the solution and recording their performances in the form of statistical summaries. These summaries, consisting of categorized results and statistical averages, are generated for each algorithm as tested over members of the problem set. The individual tests are composed of a series of runs from random starts over a member of the problem set. Descriptions of the test technique, test problem, and test results are provided. 3 figures, 2 tables.
School-based management committees in low-income countries: Can they improve service delivery?

With the advent of school-based management, citizen committees in low-income countries or areas are often expected to oversee the functioning of schools, health centres, and other community resources. However, studies of their effectiveness show mixed results. Though members of such committees may be able to repair buildings, they often cannot monitor the quality of instruction or of medical services. This article draws on psychological research to predict the performance of such committees, given their levels of education, group dynamics, and complexity of decisions. The research suggests that committees of the very poor may lack the time and resources to make good decisions; they also lack the experience with quality schools to accurately evaluate service delivery. Thus, donors and governments must understand better the decision-making dilemmas of people with limited literacy. Targeted research may clarify the chains of causality leading from management committee decisions to service delivery and may help improve services to the poor.
Effect of a superovulation drug on the synthesis and release of CA 125 by ovarian cells in culture

Abstract Objective: Superovulation drugs increase the incidence of ovarian cancer. In this study, we investigated the effect of a menotropin on the synthesis and secretion of the ovarian tumor marker CA 125 by ovarian cells in culture. Methods: NIH-OVCAR-3 cells (ATCC, MD) were incubated in RPMI-1640 medium with 20% fetal bovine serum for different periods in the absence and presence of Humegon at different doses. CA 125 (U/mL) secreted into the medium at 2, 4, 6, 8, and 10 days was measured by a radioimmunoassay kit. Immunoreactive CA 125 levels in the cells were determined by Western Blot studies. Results: Repeated-measures analysis of variance was used for the analysis of data, to compare means (mean ± SEM of 6 data points; ‘significantly‘ = P Conclusion: Humegon increased both the secretion and synthesis of the ovarian tumor marker CA 125 by ovarian cells in culture. It is not known whether the 30–40-fold increase of this tumor marker in the cells is transient or prognostic of any neoplastic change to occur later.
Energy Transfer Dynamics in LH2 Complexes of Rhodopseudomonas Acidophila Containing Only One B800 Molecule

Nonphotochemical hole burning (NPHB) and femtosecond pump-probe experiments have previously shown that following their excitation, the B800 molecules of the LH2 complex of Rhodobacter sphaeroides and Rhodopseudomonas(Rps.) acidophila relax by two channels. The decay channel observed for excitation on the low energy side of the B800 absorption band is due to B800fB850 excitation energy transfer which occurs in 2 ps at 4 K. The additional decay channel becomes detectable for excitation on the high energy side of the B800 band. The mechanisms that have been proposed for this channel are: (i) vibrational relaxation following excitation of vibronic levels associated with the Qy-states of either the B800 or B850 bacteriochlorophyll a molecules; (ii) direct excitation of upper B850 exciton levels, followed by downward relaxation within the B850 manifold; (iii) intraband B800-B800 energy transfer involving only the B800 molecules; and (iv) downward energy transfer of initially excited mixed B800-B850 states. Presented here are NPHB results for intact LH2 and B800-deficient LH2 complexes of Rps. acidophila (strain 10050). The latter contain only one B800 molecule, rather than nine. In sharp contrast with the intact LH2 complex, the zero-phonon holewidths for the B800-deficient LH2 complex were observed to be independent of the location of the burn frequency within the B800 band, 3.2 ( 0.3 cm -1 at 4 K. This finding and others eliminate the first two of the above mechanisms. It is argued that the third mechanism is highly unlikely. It is proposed that mixed B800-B850 states are mainly responsible for the additional decay channel. These mixed states could undergo downward relaxation to B800 levels that are mainly “B800” in character and to levels that are mainly “B850” in character.
Cyclosporines: correlation of immunosuppressive activity and inhibition of bone resorption.

Cyclosporine A (CsA) is a potent immunosuppressive agent that inhibits stimulated bone resorptionin vitro. To study the mechanism of this effect, we have compared CsA with several cyclosporine analogs that vary in immunosuppressive potency. CsA as well as another potent immunosuppressive analog, CsG, inhibited parathyroid hormone (PTH) and interleukin-1 (IL-1)-stimulated resorption of fetal rat limb bones. The nonimmunosuppressive analogs CsH and CsF did not inhibit PTH or IL-1-stimulated bone resorption. Likewise, the weakly immunosuppressive analog CsD did not significantly inhibit PTH-stimulated bone resorption. Although other mechanisms cannot be excluded, our data are consistent with the concept that bone resorption may involve an immune cell-derived mediator.
Intramolecular vibrational energy relaxation in benzene

Abstract Preliminary results are reported of a Monte Carlo trajectory study of intramolecular vibrational energy relaxation in a model of benzene. Very little relaxation is found to occur on a picosecond timescale. The rate of intramolecular vibrational energy relaxation appears to be dependent upon the nature of the initial energy distribution. Deuteration causes a pronounced increase in the relaxation.
IMPACT OF PARALLEL PROCESSING ON JOB SEQUENCES IN FLEXIBLE ASSEMBLY SYSTEMS

Parallel processing offers several advantages. However, when processing times are allowed to vary, it can result in unpredictable job sequences. This issue must be addressed in assembly systems where it is necessary to match specific jobs with specific materials downstream. This research analyses job sequences after parallel processing and provides strategies for dealing with jobs getting out of sequence. One strategy involves re-sequencing materials using material buffers and another involves re-sequencing jobs using job buffers. A simple analysis determines the size of material buffers. The size of job buffers is estimated using analytical approximation and formulas fitted to simulation results.
Mixed mode fatigue crack growth in test coupons made from 2024-T3 aluminum

In this paper, two different fracture criteria are applied to determine the crack trajectory or angle of crack propagation in test specimens containing inclined cracks emanating from open holes. Also, different crack growth rate models are assumed for each criterion. The maximum principal stress criterion is used with a crack growth-rate equation based on an effective stress intensity factor. The strain energy density criterion is used with a crack growth-rate equation corresponding to an effective strain energy density factor. The crack growth-rate models for each criterion were constructed using unpublished fatigue crack growth data for 2024-T3 aluminum.
Strategies of inducing cooperation: an experimental study:

Abstract : Ss played a two-person laboratory game in which they could act altruistically, individualistically, defensively, or aggressively. Ss did not interact with a real person, but 5 programmed strategies were employed to see which was most effective in eliciting cooperation from a non-cooperative S. The strategies were: Turn The Other Cheek - the program responded to a threat or an attack by an altruistic choice and with a cooperative choice otherwise; Nonpunitive - the program responded defensively rather than with counter-threats or counter attacks when the S threatened or attacked, and reciprocated the rest of the S's behavior; Deterrent - the program responded with a threat to any noncooperative act of the S, counter attacked when the S attacked and responded cooperatively to any cooperative behavior from the S; two types of Reformed Sinner strategy - in both the program responded with threats and aggression for the first 15 trials of the game and then changed dramatically on the 16th trial by disarming. In one form of the Reformed Sinner the program followed the Turn The Other Cheek strategy, and in the other the program became Nonpunitive. Results are consistent with findings of other investigators. Ss behaved most competitively during the 15 trials of the Reformed Sinner condition when the program was threatening and aggressive; Ss tended to exploit in the Turn The Other Cheek condition; Ss behaved most cooperatively in the Nonpunitive condition. (Author)
Mathematical modeling as accounting: predicting the fate of serum proteins and therapeutic monoclonal antibodies.

Abstract This article reviews current efforts to mathematically model the half lives of serum proteins, especially antibodies. While it is recognized that the neonatal Fc receptor, FcRn, is necessary for longer serum persistence of certain proteins, particularly the high abundance IgGs and albumin, it is not clear that it is sufficient to completely determine the half lives of these proteins. More specifically, it is unclear why the high avidity (bivalent), high affinity FcRn-IgG interaction, with half saturation in the 10 to 100 nM range (at endosomal pH according to the currently proposed mechanism), would result in a salvage mechanism that saturates at serum concentrations in the 10 to 100 mg/ml range – a discrepancy of 4 to 5 orders of magnitude. Alternative explanations include the proposal that the very low affinity binding between FcRn and IgG at blood pH is also relevant to the salvage mechanism, and that factors in addition to FcRn binding modulate the maintenance and clearance of IgG from serum.
Vaginal douching in teenagers attending a family planning clinic

Abstract This study assessed the knowledge and usage patterns of vaginal douching in sexually active teenagers attending a family pluming clinic. A questionnaire was administered consecutively to 94 black, 36 Hispanic, and 12 Anglo females ranging in age from 13 to 19 years. The survey showed that vaginal douching is a common practice, with almost two thirds learning about douching from their mother. The technique is primarily used for hygienic reasons with few using it to prevent pregnancy or infection. Age of first douche correlated with age of first intercourse (p
CHROMOSOMAL REGIONS CONTAINING NEW CANDIDATE ONCOGENES AND TUMOR SUPPRESSORS IN WILMS TUMOR DETECTED BY COMPARATIVE GENOMIC HYBRIDIZATION. • 894

Comparative genomic hybridization (CGH) is a newly described molecular cytogenetic assay that produces a global map of DNA sequence copy number as a function of chromosomal location throughout the genome. This technique has the ability to detect discrete regions of tumor cell chromosomal imbalance (either loss or gain) which are often near loci of cellular oncogenes or tumor suppressor genes implicated in tumor development. We used CGH to detect and compare recurring cytogenetic abnormalities in both sporadic and familial cases of Wilms tumor, a common pediatric neoplasm of renal origin whose conventional cytogenetic features are complex and often difficult to interpret. For the analyses of sporadic cases, DNA was extracted from tumors of favorable histology obtained from patients of similar clinical stage; patients were divided into two groups (treatment failures and non-failures) based upon their clinical outcome. CGH demonstrated chromosome 16q deletions in patients who failed therapy, a cytogenetic feature also appreciated by allelotype analysis. In addition, previously unrecognized amplification of chromosome 1q23 as well as frequent alterations of chromosomes 6, 7, 11, 12, and 13 were also found. While familial tumors shared some of the same cytogenetic abnormalities as sporadic tumors (including deletions of chromosomes 11q and 16q as well as whole chromosome 12 gains), this group of cases was specifically characterized by a high frequency of loss on chromosomes 4q and 9p. Simultaneous 99% confidence intervals based on a mixed model provided statistical confirmation of the observed tumor-specific chromosomal imbalances. These data indicate that sporadic and familial Wilms tumors have distinct genetic abnormalities as revealed by CGH. Further, our studies refine the location of specific loci that may harbor genes of biologic importance for the development or progression of Wilms tumor.
Group-Based Assessment as a Dynamic Approach to Marketing Education

Assessment is a prominent issue in education today. However, assessment of learning often occurs only at the end of the semester to satisfy accreditation agencies. An alternative is to conduct asse...
Using Technology to Improve our Management of Labour Market Trends

A framework is presented for the strategic use of technology choices as potential solutions for human resources problems arising from demographic trends and labour market conditions. Rather than having technology choice decisions driven by largely financial or engineering concerns, the framework starts with the availability of human resources as its major consideration in choosing technologies which will eliminate jobs which organisations may not be able to fill, and augment or capitalise on skills the workforce does possess. Combining human resource planning and technology planning can thus help organisations achieve a strategic advantage.
Distraction and compression loads enhance spine torsional stiffness

We have assessed the degree to which compression and distraction forces applied to the spine of the magnitude achievable through instrumentation systems increase torsional stiffness, thereby possibly enhancing the environment for arthrodesis. A functional relationship between spine torsional stiffness and axial compression and distraction forces is described. To establish this relationship whole human thoracolumbar spines as well as individual motion segments were tested in torsion under a variety of axial loading conditions consistent with forces applied clinically. These studies indicate that applying axial loads to the whole thoracolumbar spine through the action of compression or distraction increases the stiffness of the spine in torsion. Compression and distraction forces increased the torsional stiffness of thoracic segments, but only compression forces were found to significantly increase the stiffness of lumbar segments. The soft tissue structures of both the anterior and the posterior columns have the ability to increase torsional stiffness with axial loading.
The Dynamics of Narcotic Abstinence: an Interactionist Theory*

Despite its theoretical and pragmatic importance, the etiology of abstinence among committed addicts has received surprisingly little attention. Based on in-depth interviews with samples of both institutionalized and noninstitutionalized addicts, this study presents a new theory of narcotic abstinence which, like much of the best work in this area, draws heavily from interactionist social psychology. Examination of the available evidence shows that, contrary to much theoretical speculation, the addict's nondeviant primary relations are not of major importance in the inception of a desire for abstinence. Rather, successful attempts at abstinence typically follow an intense “existential crisis” which forces the addict to reevaluate substantial parts of the symbolic motivational structures which create and sustain addiction. The reasons for the onset of this personal crisis, and the range of the addict's typical responses, are examined as part of an overall theory of abstinence.
Coagulation and dispersion of red mud suspensions

Abstract Red mud is a waste stream the Bayer process for alumina production. This paper deals mainly with the influence of pH on the coagulation and dispersion of red mud suspensions. For the purpose of understanding the coagulation and dispersion phenomena of dilute red mud suspensions, the relationship between zeta potential of red mud and pH is measured, and the phenomena in the case of basic suspensions are analyzed by using the experimental data of zeta potential and the DLVO theory. It is shown that the theory agrees fairly well with the experimental results. Furthermore, measurements of the specific volume of sediment, the zeta potential, the mass fraction of less than 2 μm in red mud and the apparent viscosity of some kinds of slurries, show that in order to entirely disperse red mud suspensions, the addition of a dispersing agent to the suspensions is necessary.
Effect of Surface Roughness on Nitrogen Flow in a Microchannel Using the Direct Simulation Monte Carlo method

The paper presents direct simulation Monte Carlo (DSMC) results for nitrogen flow in a microchannel with surface roughness modeled by an array of rectangular modules placed on one side of a parallel-plate channel. The effects of relative surface roughness, roughness distribution, and gas rarefaction on flow are investigated and the results are presented in the form of the product of friction factor and Reynolds number. It was found that the effect of surface roughness is more pronounced at low Knudsen numbers. At high Knudsen numbers, rarefaction reduces the interaction between the gas molecules and the channel walls and results in a lower friction factor. The roughness distribution represented by the ratio of the roughness height to spacing of the modules has a significant effect on the flow and friction factor. Finally, the locally fully developed (LFD) flow model can be used to predict gas flow in a microchannel with low values of relative surface roughness.
Appropriate timing of elective coronary artery bypass graft surgery following acute myocardial infarction

Abstract Background: The appropriate timing of elective coronary artery bypass surgery (CABG) following acute myocardial infarction (AMI) remains uncertain. It is hypothesized that a waiting period allows the myocardium to recover prior to revascularization, thus decreasing morbidity and mortality. This study was designed to determine if a waiting strategy is justified following AMI in patients requiring elective CABG. Methods: Between 1994 and 1996, 214 patients underwent isolated, nonrepeat, elective CABG. Three groups were evaluated: group I, control, 155 patients with no AMI; group II, 39 patients with nontransmural AMI; and Group III, 20 patients with transmural AMI. Demographics, intraoperative, and postoperative variables were collected and compared among all groups. Results: Groups were well-matched demographically: group I, patients waited an average of 2.3 days in hospital prior to operation; group II, an average of 4.2 days; and group III, an average of 5.2 days. Except for the use of inotropes, group I 34%, group II 39%, and group III 70% (P = 0.007), and the intra-aortic balloon pump, group I 0%, group II 8%, and group III 25% (P = 0.001). There were no differences in complications. Importantly, there was no difference in mortality or postoperative length of stay. The mortality in group I was 2.6%, in group II 2.6%, and in group III 0%. The length of stay in groups I and II was 8.5 days, and in group III, 8.1 days. Conclusion: A waiting period of 3 to 5 days after a nontransmural AMI and 5 to 7 days after a transmural AMI can produce similar postoperative results to non-AMI patients undergoing CABG. Thus, a waiting strategy to allow the myocardium to recover is justified.