cssi/SciSciGPT-SciSciNet huggingface dataset:
Quantitative Three-Dimensional Echocardiographic Correlates of Optimal Mitral Regurgitation Reduction during Transcatheter Mitral Valve Repair.

Background Patient selection for transcatheter edge-to-edge mitral valve repair (TMVR) remains challenging because of heterogenous mitral valve pathology and highly variable anatomy. The aim of this study was to investigate whether quantitative three-dimensional (3D) transesophageal echocardiographic modeling parameters are associated with optimal mitral regurgitation (MR) reduction in patients undergoing TMVR. Methods Fifty-nine patients underwent 3D transesophageal echocardiography during TMVR. Volumetric data sets were retrospectively analyzed using mitral valve quantitative 3D modeling software (Mitral Valve Navigator). Optimal MR reduction was defined as less than moderate residual MR. Logistic regression was used to correlate 3D transesophageal echocardiographic quantitative data to procedural success. Results Thirty-five patients had primary MR, 24 had mixed or secondary MR, and all patients had grade ≥ 3/4 MR before the procedure. Optimal MR reduction was achieved in 40 of 59 patients (68%). Univariate correlates of optimal MR reduction in patients with primary MR were lower mitral leaflet tenting volume (P = .049) and lower tenting height (P = .025); tenting height Conclusions Quantitative 3D echocardiographic data are associated with favorable response to TMVR and could help optimize patient selection.
mWarp: Accelerating Intra-Host Live Container Migration via Memory Warping

Live container migration allows containers to roam from one server to another to achieve agility goals like load balancing, tackling machine failures, scaling in/out and reallocating resources. However, migrating a container is also costly mainly due to memory state migration — a large number of memory pages need to be copied from the source server to the destination server. In this paper, we propose a fast and live container migration approach, mWarp, in an intra-host scenario, where both the source and destination virtual machine (VM) servers reside on the same physical host. Instead of copying a container's memory, mWarp relocates the ownership of the container's physical memory pages from the source VM to the destination VM with a highly-efficient memory remapping mechanism. As relocation of memory ownership is light-weight, mWarp leads to fast and live container migration with less service disruption to applications running in containers being migrated. We implement mWarp upon a well-known live container migration tool (CRIU) with key kernel/hypervisor-level support. The evaluation with both micro benchmarks and real-world applications shows that mWarp greatly reduces the total container migration time and downtime (e.g., by an order of magnitude) with significantly improved application-level performance (e.g., by 20%).
Leadership Rebooted: Cultivating Trust with the Brain in Mind

Today’s human service organizations demand innovative leadership to effectively manage outcomes, turnover, and respond to the environment. Through neuroscience-informed approaches, leaders align th...
Modeling first bid in retail secondary market online auctions: A Bayesian approach

We propose a Bayesian framework to model bid placement time in retail secondary market online business‐to‐business auctions. In doing so, we propose a Bayesian beta regression model to predict the first bidder and time to first bid, and a dynamic probit model to analyze participation. In our development, we consider both auction‐specific and bidder‐specific explanatory variables. While we primarily focus on the predictive performance of the models, we also discuss how auction features and bidders' heterogeneity could affect the bid timings, as well as auction participation. We illustrate the implementation of our models by applying to actual auction data and discuss additional insights provided by the Bayesian approach, which can benefit auctioneers.
Qualitative analyses of nursing home residents’ quality of life from multiple stakeholders’ perspectives

Quality of life has been defined in various ways by nursing home stakeholders over the years. As such, analyzing the levels of agreement or disagreement among these stakeholders to ascertain if staff and leadership align with resident-identified factors for “good” quality of life has become important to include in the literature. This study sought to identify contributory factors to resident quality of life, as well as analyze areas of commonality in qualitative responses. Semi-structured interviews were conducted at 46 Midwestern nursing homes, with residents (n = 138), nursing assistants (n = 138), social workers (n = 46), activities directors (n = 46), and administrators (n = 46), on whether each stakeholder felt residents had a good quality of life and the factors contributing to resident quality of life. Overall, the majority of residents perceived their quality of life as “good,” though differences were noted in their main contributing factors when compared to staff members’ and management’s perspectives. Findings also demonstrated that nursing assistants most closely aligned with resident perspectives. Given the implications of resident satisfaction with quality of life on multiple facets of a nursing home (e.g., survey process, financial reimbursement), it remains ever critical for management to engage residents and to truly listen to resident perspectives to enhance and ensure an optimal quality of life.
Effects of Facebook Comments on Attitude Toward Vaccines: The Roles of Perceived Distributions of Public Opinion and Perceived Vaccine Efficacy

This study investigated if and how exposure to Facebook comments about vaccines influences one’s attitude toward the vaccines. In this investigation, comments were examined in light of their effect...
Oral Manifestations in Turner Syndrome

Females with Turner syndrome (TS) have a variety of dental problems. Females with 45,X or with 45,X/46,isoXq mosaicism have more severe oral and dental anomalies, while those with a 45,X/46,XX karyotype tend to have abnormalities in line with the general population.
Peripheral Vascular Disease

Peripheral arterial disease (PAD), although relatively benign in its outlook for the legs, is a serious prognostic marker for future stroke, myocardial infarction, and vascular death. Patients with PAD can be expected to have chronically activated, hyperreactive platelets, and the severity of the derangement trends with the burden or extent of the atherosclerotic vascular disease. Studies of PAD patients have demonstrated increased spontaneous platelet aggregation, lower thresholds to activation by soluble agonists such as ADP or thrombin, increased platelet–leukocyte aggregates, and higher circulating products of platelet activation. The frequently associated risk factors of hyperlipidemia, diabetes, hypertension, and smoking also contribute to chronic platelet activation.
Projecting Health Impacts of Future Temperature: A Comparison of Quantile-Mapping Bias-Correction Methods.

Health impact assessments of future environmental exposures are routinely conducted to quantify population burdens associated with the changing climate. It is well-recognized that simulations from climate models need to be bias-corrected against observations to estimate future exposures. Quantile mapping (QM) is a technique that has gained popularity in climate science because of its focus on bias-correcting the entire exposure distribution. Even though improved bias-correction at the extreme tails of exposure may be particularly important for estimating health burdens, the application of QM in health impact projection has been limited. In this paper we describe and apply five QM methods to estimate excess emergency department (ED) visits due to projected changes in warm-season minimum temperature in Atlanta, USA. We utilized temperature projections from an ensemble of regional climate models in the North American-Coordinated Regional Climate Downscaling Experiment (NA-CORDEX). Across QM methods, we estimated consistent increase in ED visits across climate model ensemble under RCP 8.5 during the period 2050 to 2099. We found that QM methods can significantly reduce between-model variation in health impact projections (50–70% decreases in between-model standard deviation). Particularly, the quantile delta mapping approach had the largest reduction and is recommended also because of its ability to preserve model-projected absolute temporal changes in quantiles.
Comparing Apples and Oranges: Fairness and Diversity in Ranking (Invited Talk).

Algorithmic rankers take a collection of candidates as input and produce a ranking (permutation) of the candidates as output. The simplest kind of ranker is score-based; it computes a score of each candidate independently and returns the candidates in score order. Another common kind of ranker is learning-to-rank, where supervised learning is used to predict the ranking of unseen candidates. For both kinds of rankers, we may output the entire permutation or only the highest scoring k candidates, the top-k. Set selection is a special case of ranking that ignores the relative order among the top-k. In the past few years, there has been much work on incorporating fairness and diversity requirements into algorithmic rankers, with contributions coming from the data management, algorithms, information retrieval, and recommender systems communities. In my talk I will offer a broad perspective that connects formalizations and algorithmic approaches across subfields, grounding them in a common narrative around the value frameworks that motivate specific fairness- and diversity-enhancing interventions. I will discuss some recent and ongoing work, and will outline future research directions where the data management community is well-positioned to make lasting impact, especially if we attack these problems with our rich theory-meets-systems toolkit.
Perceptions of Autism Spectrum Disorder (ASD) Etiology among Parents of Children with ASD.

Background: Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social communication deficits and restricted or repetitive behaviors. Parental perceptions of the etiology of their child’s ASD can affect provider–client relationships, bonding between parents and their children, and the prognosis, treatment, and management of children with ASD. Thus, this study sought to examine the perceptions of ASD etiology of parents of children with ASD. Methods: Forty-two parents of children diagnosed with ASD were recruited across Texas. Semi-structured interviews were conducted individually. All interviews were recorded and later transcribed verbatim for content analysis utilizing NVivo 12.0 (QSR International, Doncaster, Australia). Results: The content analysis identified the following themes regarding parental perceptions of ASD etiology: Genetic factors (40.5%), environmental factors (31.0%), problems that occurred during pregnancy or delivery (23.8%), vaccinations (16.7%), other health problems (7.1%), parental age at the time of pregnancy (4.8%), and spiritual or religious factors (2.4%). Conclusions: The parental perceptions of ASD etiology were diverse, but several views, such as vaccinations and spiritual or religious factors, were not based on scientific evidence. Health professionals and researchers can use these findings to develop and provide targeted education to parents who have children with ASD. Our findings also support policymakers in developing campaigns designed to increase parental ASD awareness and knowledge.
Disruption of origin chromatin structure by helicase activation in the absence of DNA replication

Prior to initiation of DNA replication, the eukaryotic helicase, Mcm2-7, must be activated to unwind DNA at replication start sites in early S phase. To study helicase activation within origin chromatin, we constructed a conditional mutant of the polymerase α subunit Cdc17 (or Pol1) to prevent priming and block replication. Recovery of these cells at permissive conditions resulted in the generation of unreplicated gaps at origins, likely due to helicase activation prior to replication initiation. We used micrococcal nuclease (MNase)-based chromatin occupancy profiling under restrictive conditions to study chromatin dynamics associated with helicase activation. Helicase activation in the absence of DNA replication resulted in the disruption and disorganization of chromatin, which extends up to 1 kb from early, efficient replication origins. The CMG holohelicase complex also moves the same distance out from the origin, producing single-stranded DNA that activates the intra-S-phase checkpoint. Loss of the checkpoint did not regulate the progression and stalling of the CMG complex but rather resulted in the disruption of chromatin at both early and late origins. Finally, we found that the local sequence context regulates helicase progression in the absence of DNA replication, suggesting that the helicase is intrinsically less processive when uncoupled from replication.
Systematic Review and Meta-Analysis of Pediatric Robotic Assisted Laparoscopic Pyeloplasty (RALP).

Introduction To perform a systematic review and meta-analysis of outcomes of robotic-assisted laparoscopic pyeloplasty for UPJ obstruction in children. Evidence acquisition A systematic review of the English-language literature on surgical techniques and perioperative outcomes of robotic-assisted laparoscopic pyeloplasty for UPJ obstruction in children was performed without time filters using the MEDLINE (via PubMed), EMBASE, and Cochrane databases in July 2020 according to the PRISMA statement recommendations. Evidence synthesis Overall, 58 studies were selected for qualitative analysis, 46 of which were included in the meta-analysis. Nearly all studies included were observational and retrospective, either cohort or case-control. The quality of evidence was assessed using Modified Newcastle Ottawa Scoring, with the majority of studies scoring medium or high quality. The mean success rate was 95.4% (CI 91.0-99.3%), over a wide age range. There was a noticeable heterogeneity in reported follow up length and definitions of success rate. The majority of studies reported length of stay of ~1 day. The mean overall complication rate was 12%. For studies that reported complication rate by grade, the mean low Clavien grade (grade 2 or less) complication rate was 9.3% and the mean high Clavien grade (grade 3 or more) complication rate was 6.5%. Conclusions Robotic assisted surgery is technically feasible and has been shown to achieve very favorable outcomes for pyeloplasty in children. The evidence however is mostly retrospective and from single sites, which introduces potential biases. Further research is needed to further elucidate RALP benefits compared to the open and laparoscopic approach. As a RCT may not be practical in this space, perhaps a prospective multi-institutional design with a uniform reporting system of pediatric RALP is the next step to define its benefits and limits.
Heat Stroke and Fluphenazine Therapy Report of a Case

Deaths coded as heat stroke or sudden heat deaths are uncommon in forensic practice, particularly in areas where heat waves are rare [1,2]. Where sporadic cases occur, additional risk factors are likely to be present. These include the use of certain drugs, particularly phenothiazines, anticholinergic agents, and amphetamines [3]. Heat stroke often pursues an extremely rapid clinical course, and investigation of fatalities may consequently become the responsibility of the medical examiner [2]. The phenomenon of the acute impairment of thermoregulation as a result of phenothiazine therapy is not generally mentioned in general medical reviews of heat stroke [4,5]. However, many psychiatrists are aware of the association, and most of the documented fatalities have been in the psychiatric literature [6ߝ9]. The purpose of this paper is to report another case, with the classic findings of sudden death by heat stroke in a man with chronic schizophrenia who was on long-acting fluphenazine decanoate (Prolixin®) therapy. Environmental temperatures and relative humidity were only moderately high, demonstrating the importance of documenting the drug history and other potential risk factors in cases of this kind.
Natural Products Research Partnerships with Multiple Objectives in Global Biodiversity Hot Spots: Nine Years of the International Cooperative Biodiversity Groups Program

The International Cooperative Biodiversity Groups (ICBGs) have been among the most ambitious bioprospecting endeavors because of the explicit intent to use the drug discovery and bioinventory research process to generate enhanced research capacity, opportunities for sustainable economic activity, and incentives for conservation at each host site. Specifically, they must include substantial and novel efforts in natural products drug discovery, biological inventory, research capacity building, and benefit sharing. The major focus of bioinventory activity to date has been terrestrial plants. Several types of ICBG activities promote conservation and development. They include training personnel and research capacity enhancement at host country institutions, scientific research in support of biodiversity management, in situ and ex situ conservation projects, environmental education, and policy analysis. These are described in detail in this chapter. The chapter also describes a few illustrative examples among the many supported by the ICBG program. In summary, in the first 9 years of the program, the ICBGs have (i) discovered numerous bioactive compounds, some of which are leads of significant continuing interest; (ii) enhanced the technical capacity of over 2,000 developing country participants and their associated institutions; (iii) contributed to the scientific and policy process of conservation; and (iv) provided important models for governments and other organizations for collaborative research that supports multiple objectives, including those of the CBD. The ICBG has pioneered the development of models for nontraditional international partnerships of universities, companies, and government and community organizations.
Proliferation and Differentiation of Human Ciliated Epithelia on PTFE-Protheses

For several years there have been efforts to develop an artificial trachea. Our efforts aimed at the development of a suitable transplant for a complex substitution of destroyed tracheal segments. It was our aim to line expanded polytetrafluorethylene (ePTFE) with human mucosal cells. Therefore we made experiments on the growth of human mucosal cells on ePTFE. We were especially interested in the proliferation kinetics of the cells on a relatively coarse net structure and in the differentiation ability of mucosal cells under such conditions.
Dietary factors affecting the urinary mutagenicity assay system: II. The absence of mutagenic activity in human urine following consumption of red wine or grape juice

Abstract The mutagenic activity of urine samples from nonsmoking individuals before and after the consumption of either red wine or grape juice was determined. Urine samples collected from individuals on liquid or regular diets were concentrated using XAD-2 resin. No mutagenic activity of urine concentrates was detected with Salmonella tester strains TA98 or TA100 with or without microsomal activation. The addition of 1000 units of β-glucuronidase into the agar overlay did not show any mutagenic activity. The mutagens in red wine and grape juice, however, were extracted using the XAD-2 column. Concentrates of urine samples spiked with either of the two extracts exhibited mutagenic activity.
RF system considerations for accelerator production of tritium and the transmutation of nuclear waste

RF driven proton accelerators for the transmutation of nuclear waste (ATW) or for the production of tritium (APT) require unprecedented amounts of CW RF power at UHF frequencies. For both systems, the baseline design is for 246 MW at 700 MHz and 8.5 MW at 350 MHz. The main technical challenges are how to design and build such a large system so that it has excellent reliability, high efficiency, and reasonable capital cost. The issues associated with the selection of the RF amplifier and the sizes of the power supplies are emphasized in this paper. >
Performance Analysis of Data-Sharing Environments

A data sharing environment consists of multiple loosely coupled transaction processing nodes sharing a common database at the disk level. Apart from the private buffers in each node, the environment may contain an additional global shared buffer in the form of disk cache, file server cache or intermediate shared memory. In this dissertation, we develop a comprehensive analytical model for such a complex environment using a hierarchical approach, where the concurrency control, the CPU queueing discipline and the buffer hit probabilities of the private and shared buffers are first modeled separately, and then integrated through an iterative procedure. To this end, we develop two new submodels: (1) the private buffer model that captures the effects of multi-system buffer invalidation, skewed database access, LRU buffer replacement policy and the rerun transactions, and (2) the shared buffer modeling framework that captures the effects of dependence between the contents of private and the shared buffers, and is used to analyze various shared buffer management policies (SBMPs) proposed in this dissertation. The various policies propagate a granule into the shared buffer after one or more of the following events: database update, shared buffer miss and private buffer replacement. The analytical model is then used to investigate various issues in the design of data sharing environment. Scalability. The model predicts degradation in transaction response time as new nodes are added to the system. Buffer utilization. The model predicts the effectiveness of additional buffer allocation for both the private and shared buffers. Skewed access. The skewed access increases both data contention and buffer hit probability in the system. The resultant effect on the transaction response time is investigated. The response time is found to be more sensitive to skewed data access under two-phase locking (2PL) than under optimistic concurrency control (OCC) protocol. The skewed access also magnifies the effect of invalidation and reduces the utilization of private buffers. Policy selection. The modeling framework is used to select the best SBMP for a given parameter range (private and shared buffer sizes, shared buffer access overhead and delay, number of nodes, database access pattern, update probabilities, etc.). The updates should always be propagated to the shared buffer to alleviate the invalidation problem. For a smaller number of nodes, the effect of dependence between the contents of the private and the shared buffers influences policy selection. Optimal configuration. The model can be used to optimally allocate the buffer between the private and the shared buffers in various system architectures depending on the overhead and delay in accessing the shared buffer. For a larger number of nodes and under skewed database access, the shared buffer can improve the transaction response time significantly.
Nursing students' career choices: a pilot study.

Factors influencing the supply and demand of nurses are complex and involve issues such as the shifting health care delivery system, an aging nursing workforce, and the changing demographics of society. Projections for the supply and demand of the nursing workforce reveal an emerging nursing shortage (American Association of Colleges of Nursing, 2000a; Bednash, 2000; Buerhaus, 1998; Buerhaus, Staiger, & Auerbach, 2000; Mailey, Charles, Piper, Hunt-McCool, Wilborne-Davis, & Baigis, 2000; Mills & Blaesing, 2000). The American Association of Colleges of Nursing (AACN) and the National League for Nursing (NLN) report a decrease in applications to, and enrollment in, all nursing programs. According to the latest survey by the American Association of Colleges of Nursing (2000b), enrollments in baccalaureate degree nursing programs have decreased for the sixth straight year, with a 4.9% drop in 1999 and a 2.1% drop in 2000. Why are students not choosing nursing as a career? What can be done to increase enrollments in nursing programs?
Probability Bounds Analysis Applied to the Sandia Verification and Validation Challenge Problem

Our approach to the Sandia Verification and Validation Challenge Problem is to use probability bounds analysis (PBA) based on probabilistic representation for aleatory uncertainties and interval representation for (most) epistemic uncertainties. The nondeterministic model predictions thus take the form of p-boxes, or bounding cumulative distribution functions (CDFs) that contain all possible families of CDFs that could exist within the uncertainty bounds. The scarcity of experimental data provides little support for treatment of all uncertain inputs as purely aleatory uncertainties and also precludes significant calibration of the models. We instead seek to estimate the model form uncertainty at conditions where the experimental data are available, then extrapolate this uncertainty to conditions where no data exist. The modified area validation metric (MAVM) is employed to estimate the model form uncertainty which is important because the model involves significant simplifications (both geometric and physical nature) of the true system. The results of verification and validation processes are treated as additional interval-based uncertainties applied to the nondeterministic model predictions based on which the failure prediction is made. Based on the method employed, we estimate the probability of failure to be as large as 0.0034, concluding that the tanks are unsafe.
Sabadilla Alkaloids VI Separation of Veratridine and Cevadine by CountercurrentDistribution. pH vs. Partition Coefficients

Abstract Contrary to previously reported results of partition studies, the plot of the partition coefficient vs. pH for both cevadine and veratridine has been shown to be linear. The two alkaloids were separated from each other in a high state of purity by countercurrent distribution with chloroform and 0.5 M citrate buffer at pH 3.95 with a relatively small number of transfers as well as on a partition column using the same conditions. A much greater number of transfers was required to separate them by countercurrent distribution with benzene and 0.5 M phosphate buffer at pH 5.85. No effective separation could be made on a partition column using the latter conditions. A nonaqueous titration for the alkaloids in benzene or chloroform solution was perfected and an ultraviolet spectral ratio method for detection and analysis of cevadine occurring with veratridine was applied.
Intraneuronal vesicular organelle transport changes with cell population density in vitro

Abstract Primary neuron cultures are widely used in research due to the ease and usefulness of observing individual cells. Therefore, it is vital to understand how variations in culture conditions may affect neuron physiology. One potential variation for cultured neurons is a change in intracellular transport. As transport is necessary for the normal delivery of organelles, proteins, nucleic acids, and lipids, it is a logical indicator of a cell's physiology. We test the hypothesis that organelle transport may change with varying in vitro population densities, thus indicating a change in cellular physiology. Using a novel background subtraction imaging method we show that, at 5 days in vitro (DIV), transport of vesicular organelles in embryonic rat spinal cord neurons is positively correlated with cell density. When density increased 6.5-fold, the number of transported organelles increased 2.2 ± 0.3-fold. Intriguingly, this effect was not observable at 3–4 DIV. These results show a significant change in cellular physiology with a relatively small change in plating procedure; this indicates that cells appearing to be morphologically similar, and at the same DIV, may still suffer from a great degree of variability.
When is 3D 2B

A key facet of "More than Moore" scaling comes under the heading of "3D"&#x2014;the stacking of multiple integrated-circuit dies using through-silicon vias (TSVs). Stacked-die products reached the marketplace decades ago, but with peripheral I/O on individual dies and interchip interconnect on the "side" of the stack. TSVs are a game changer, as this column explains.
Short-channel graphene nanoribbon transistors with enhanced symmetry between p- and n-branches

Graphene’s unique symmetry between p- and n-branches has enabled several interesting device applications; however, short-channel devices often exhibit degraded symmetry. We examine how graphene nanoribbon geometries can improve transfer characteristics and p–n symmetry, as well as reduce Dirac point shift for highly scaled graphene devices. RF graphene transistors utilizing a multiribbon channel are fabricated with channel length down to 100 nm, achieving 4.5-fold improved transconductance, 3-fold improved cutoff frequency, and 2.4-fold improved symmetry compared with sheet devices. The improved performance is linked to reduced contact effects by modeling the extent of charge transfer into the channel as a function of graphene width.
Flag Enumeration in Polytopes, Eulerian Partially Ordered Sets and Coxeter Groups

We discuss the enumeration theory for ags in Eulerian partially ordered sets, emphasizing the two main geometric and algebraic examples, face posets of convex polytopes and regular CW -spheres, and Bruhat intervals in Coxeter groups. We review the two algebraic approaches to ag enumeration { one essentially as a quotient of the algebra of noncommutative symmetric functions and the other as a subalgebra of the algebra of quasisymmetric functions { and their relation via duality of Hopf algebras. One result is a direct expression for the Kazhdan-Lusztig polynomial of a Bruhat interval in terms of a new invariant, the complete cd-index. Finally, we summarize the theory of combinatorial Hopf algebras, which gives a unifying framework for the quasisymmetric generating functions developed here.
Conducting high-cycle fatigue strength step tests on gamma TiAl

High cycle fatigue strength testing of gamma TiAl by the step test method is investigated. A design of experiments was implemented to determine if the coaxing effect occurred during testing. Since coaxing was not observed, step testing was deemed a suitable method to define the fatigue strength at 106 cycles.
Meaning and Memory: A Heideggerian Analysis of Children's First Memories

In this paper I seek to provide the theoretical basis and empirical evidence for an existential phenomenological understanding of memory. Through an explication of Heideggers's understanding of time as “world time,” I offer a critique of memory as it is understood in the current cognitive-constructivist paradigm of psychology which understands memory within the framework of “clock time.” Through examples from 51 drawings and descriptions of children's first memories, which I collected from Danish elementary school children, I demonstrate how the framework of “world time” opens up a less reductionistic and more meaningful way of understanding the phenomenon of memory.
The global asymptotic stability of prey-predator systems with second-order dissipation

Models of biological development, evolution and control should take into account that very small numbers of cells or chemicals or individuals eventually grow into stable, large populations. The simplified two-component model used in these studies includes the following: (1) first-order decay; (2) first-order autocatalysis; (3) negative feedback; (4) positive feedback; (5) second-order decay; (6) second-order autocatalysis. A positive definite Lyapunov function is constructed and shown to have a negative definite total derivative. The stationary statex>0,y>0, therefore possesses global asymptotic stability. This means that sustained oscillations cannot occur. Another stationary state,x=y=0, is shown to be unstable. This means that infinitesimally small perturbations ofx=y=0 will result in evolution of the variables to the stable stationary state. This result contrasts with that obtained with the Lotka-Volterra model in that small perturbations ofx=y=0 for that model result in sustained, oscillating excursions; the smaller the initial perturbations, the larger these excursions will be.
Standard error of lc50 and sample size in fish bioassays

Abstract The relationship between the relative error and sample size in fish bioassays was investigated empirically and theoretically. It was shown that if the mean concentration tested is near the estimated lc 50 and the same sample size is used at each test level, the dependence of relative error on sample size is predictable. Increasing the sample size significantly reduces the standard error of the estimated lc 50 until the sample size reaches about 30 fish.
Structure-property behaviour of soluble polyimide-polydimethylsiloxane segmented copolymers

Abstract New, high-molecular-weight, randomly coupled poly(siloxane imide) soluble segmented copolymers have been synthesized from bis(aminopropyl) polydimethylsiloxane oligomers of controlled molecular weights and a series of dianhydride and diamine monomers. A solution imidization procedure was used to convert quantitatively the poly(siloxane amic acid) intermediates to the corresponding polyimides. The solution imidization procedure is based upon the co-amide solvents N-methylpyrrolidinone and cyclohexylpyrrolidinone and is conducted at milder temperatures than the classical bulk imidization. The bulk imidization technique requires temperatures of approximately 300°C, in slight excess of the ultimate glass transition. The solution imidization technique, on the other hand, is conducted at approximately 160°C. The poly(siloxane imide) segmented copolymers are flexible, tough, transparent and soluble, and are possible candidates for environmentally stable composite matrix resins, coatings and structural adhesives. Upper glass transition temperatures of many copolymers approach those of the unmodified controls, indicating good microphase separation. Lap shear strengths achieved against surface-treated titanium showed that relatively good adhesion could be achieved under practical bonding conditions. Moreover, the values were basically unchanged as a function of siloxane content at low siloxane levels. Photoelectron spectroscopy demonstrated that the top surface ( ∼ 10 A ) is dominated by the siloxane. Significant reductions in the dielectric constant were obtained by incorporating fluorinated dianhydrides and hydrophobic aromatic diamines into the polyimide structure. Lower moisture sorption may also be obtained via siloxane modification and by the use of more non-polar reactants.
Age, ambition, and the local charter: a study in voting behavior

Abstract This article tests ambition theory by looking into the relatively unexplored area concerning the voting behavior of local charter committee members. Our findings lend support to the notion in ambition theory that age is an important factor in understanding voting blocs and differences on issues. More specifically, our study suggests that differences in political ambition along age lines may help explain different attitudes toward issues of charter reform.
A new method for the Lebedev-Ufliand integral equation for contact problems of elasticity

Let a circular flat punch penetrate a finitely thick slab resting on a rigid foundation. Lebedev and Ufliand showed that the determination of the stresses and displacements can be reduced to solving the Fredholm integral equation {ie181-1} We show how to reduce this integral equation to a Cauchy system in which λ plays the role of the time-like variable. Numerical experiments show the computational efficacy.
Determination of the RNA Binding Specificity of the Heterogeneous Nuclear Ribonucleoprotein (hnRNP) H/H′/F/2H9 Family

Members of the heterogeneous nuclear ribonucleoprotein (hnRNP) H protein family, H, H′, F, and 2H9, are involved in pre-mRNA processing. We analyzed the assembly of these proteins from splicing extracts onto four RNA regulatory elements as follows: a high affinity hnRNP A1-binding site (WA1), a sequence involved in Rev-dependent export (p17gag INS), an exonic splicing silencer from the β-tropomyosin gene, and an intronic splicing regulator (downstream control sequence (DCS) from the c-src gene. The entire family binds the WA1, instability (INS), and β-tropomyosin substrates, and the core-binding site for each is a run of three G residues followed by an A. Transfer of small regions containing this sequence to a substrate lacking hnRNP H binding activity is sufficient to promote binding of all family members. The c-src DCS has been shown to assemble hnRNP H, not hnRNP F, from HeLa cell extracts, and we show that hnRNP 2H9 does not bind this element. The DCS contains five G residues followed by a C. Mutation of the C to an A changes the specificity of the DCS from a substrate that binds only hnRNP H/H′ to a binding site for all hnRNP H family members. We conclude that the sequence GGGA is recognized by all hnRNP H family proteins.
Challenges in Testing Complex Systems

Many space programs depend on cutting-edge technology to increase computational power without increasing the power or weight of the payload. For these types of programs, component testing is necessary to ensure that the components do not fail while deployed. Radiation testing for advanced technology components can be challenging since the underlying architecture and organization of the component might be complex. This paper will cover a review of component testing best practices for total ionizing dose and single-event effect testing from recent years.
Monitoring the long-term molecular epidemiology of the pneumococcus and detection of potential 'vaccine escape' strains.

Background While the pneumococcal protein conjugate vaccines reduce the incidence in invasive pneumococcal disease (IPD), serotype replacement remains a major concern. Thus, serotype-independent protection with vaccines targeting virulence genes, such as PspA, have been pursued. PspA is comprised of diverse clades that arose through recombination. Therefore, multi-locus sequence typing (MLST)-defined clones could conceivably include strains from multiple PspA clades. As a result, a method is needed which can both monitor the long-term epidemiology of the pneumococcus among a large number of isolates, and analyze vaccine-candidate genes, such as pspA, for mutations and recombination events that could result in ‘vaccine escape’ strains. Methodology We developed a resequencing array consisting of five conserved and six variable genes to characterize 72 pneumococcal strains. The phylogenetic analysis of the 11 concatenated genes was performed with the MrBayes program, the single nucleotide polymorphism (SNP) analysis with the DNA Sequence Polymorphism program (DnaSP), and the recombination event analysis with the recombination detection package (RDP). Results The phylogenetic analysis correlated with MLST, and identified clonal strains with unique PspA clades. The DnaSP analysis correlated with the serotype-specific diversity detected using MLST. Serotypes associated with more than one ST complex had a larger degree of sequence polymorphism than a serotype associated with one ST complex. The RDP analysis confirmed the high frequency of recombination events in the pspA gene. Conclusions The phylogenetic tree correlated with MLST, and detected multiple PspA clades among clonal strains. The genetic diversity of the strains and the frequency of recombination events in the mosaic gene, pspA were accurately assessed using the DnaSP and RDP programs, respectively. These data provide proof-of-concept that resequencing arrays could play an important role within research and clinical laboratories in both monitoring the molecular epidemiology of the pneumococcus and detecting ‘vaccine escape’ strains among vaccine-candidate genes.
Coupling of Bernstein modes in two- and three-dimensional plasmas and effect on their lifetimes

Abstract We obtain the dispersion relation and lifetime in the low-wavenumber regime for Bernstein modes in a 2D electron gas when they are coupled electrostatically to the Bernstein modes and magnetoplasmons in the bulk 3D gas. It is shown that the group velocity of the coupled 2D–3D Bernstein modes is affected by the non-local coupling between the Bernstein mode in the 2D system and the bulk modes in the adjoining layers. We also calculate the lifetimes of these coupled modes as a function of magnetic field, which is applied perpendicular to the plane of the 2D electron gas.
PHOSPHORYLATION OF NUCLEAR PROTEINS FROM RABBIT CEREBRUM, CEREBELLUM AND LIVER IN VITRO

— Phosphorylation of nuclear protein was investigated with isolated nuclei from rabbit cerebral cortex, cerebellum and liver by using [γ-32P]ATP. The results were compared with the previously reported findings on phosphorylation with tissue slices and [32P]phosphate. Cerebral cortex showed a very high level of phosphorylation, while liver showed the lowest, the difference being several fold in magnitude. With each tissue source, the extent of phosphorylation was maximum at incubation period for 2–3 min with steady decline afterwards. When nuclear proteins were further fractionated into 0.14m-NaCl-soluble, 0.25 n-HCl-soluble (mainly histone) and acidic phenol-soluble proteins, NaCl-soluble protein showed the highest phosphorylation while HCl-soluble the lowest. The ratio among these tissue sources studied and the ratio among various protein fractions in each tissue source were strikingly similar to what had been shown with tissue slices. Further separation of acidic phenol-soluble protein with polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulfate revealed retention of the characteristic difference of the pattern of phosphorylation between liver and the CNS tissue as having been observed with tissue slices, although phosphorylation of proteins with molecular weights of less than 40,000 was much reduced with the isolated nuclei. Although other methods with extracted protein kinase or chromatic protein fractions might be more desirable under ordinary situations, the system for nuclear protein phosphorylation with isolated nuclei and [γ-32P]ATP may be useful under certain experimental conditions provided the incubation condition is carefully selected.
Hiring, Training, and Retaining the Hard‐Core

Summary The objective of this paper is to present a model that can explain and predict behavior on programs designed to hire, train, and retain the hard-core unemployed. More than 50 variables and their relationships have been specified. Some of these variables have been identified in other studies, or can be derived from the organization change literature, but this paper tries to provide a comprehensive list of the extensive set of empirically based variables.
Glucosinolates in Brassica vegetables. Analysis of 22 varieties of Brussels sprout (Brassica oleracea var. gemmifera).

The glucosinolate content of 22 cultivars of Brussels sprout have been determined. The levels of total glucosinolates, determined by methods based on glucose release and gas chromatography, were substantially higher than those reported by other workers for cabbage and Chinese cabbage. The major glucosinolates in Brussels sprout leaf material were identified as gluconapin, progoitrin, sinigrin and glucobrassicin, with the latter two generally predominating. Detailed analysis of the material from five different growing sites has shown considerable variation in the total content but surprisingly little difference in the relative proportions of the individual glucosinolates within each cultivar. The glucosinolates of the corresponding seed material differ significantly from that in leaf; in particular glucobrassicin is found in trace amounts only, and glucoerucin, glucotropaeolin and neoglucobrassicin are all present, in addition to sinigrin, progoitrin and gluconapin.
Quantifying the effects of product family decisions on material selection: A process-based costing approach

Abstract Product designers must continually assess trade-offs among various performance attributes and cost. Materials choice can play an important role in that decision-making process. Product platforms are used to meet the demand for increased product variety, while also managing costs. Because of their interdependent effects, it is possible that platforming strategies may alter preferred material choice. This paper examines the interrelationship of these early stage design choices through the application of process-based cost modeling. A case study is detailed concerning two alternative material options for an automotive instrument panel beam: a die-cast magnesium design and a conventional design (i.e., discrete stamped steel components) which allows for more component sharing than the integrated magnesium design. The effects of component sharing on product family costs are analyzed. It is shown that the magnesium design is less competitive in platformed scenarios.
Micromachined SiO 2 microcantilever for high sensitive moisture sensor

Ultra-sensitive and selective moisture sensors are needed in various industries for processing control or environmental monitoring. As an outstanding sensor platform, surface-stress sensing microcantilevers have potential application in moisture detection. To enlarge the deflection of the microcantilever under surface stress induced by specific reactions, a new SiO2 microcantilever is developed which features a much lower Young’s modulus than conventional Si or SiNx microcantilevers. For comparing SiO2 cantilever with Si cantilevers, a model of the cantilever sensor is given by using both analysis and simulation, resulting in good agreement with the experimental data. The results demonstrate the SiO2 cantilever can achieve a much higher sensitivity than the Si cantilever. In order to fabricate this device, a new fabrication process using isotropic combined with anisotropic dry etching to release the SiO2 microcantilever beam by ICP (Inductively Coupled Plasma) was developed and investigated. This new process not only obtains a high etch rate at 9.1 μm/min, but also provides good profile controllability, and a flexibility of device design. Attributed to the high sensitivity, a significant deflection amplitude of the surface modified SiO2 microcantilever was observed upon exposure to 1% relative humidity. The SiO2 cantilevers are promising for inexpensive and highly sensitive moisture detection.
The Persistence of High Fertility in the American South on the Eve of the Baby Boom

Pockets of high fertility persisted in some areas of the American South through the Great Depression. Most other areas of the country adopted modern fertility patterns considerably earlier in the century; these "laggard" areas are clear exceptions to the national demographic revolution in family building. In this paper we attempt to identify the factors that account for the persistently high fertility in some southern regions. We use county-level data for 1940 to assess the utility of three theoretical models of fertility: structural, diffusion-innovation, and health. Differences by race are also considered, in view of the distinctly different histories of whites and African-Americans in the south. Our findings suggest that unicausal explanations for the persistence of high fertility are too simplistic; all three theoretical perspectives receive empirical support. Considerable similarity is observed in the findings for blacks and for whites. Yet important differences also emerge, especially the more powerful effects of structural variables on white fertility. We conclude that the evidence indicates the need for "diversity" in the study of demographic behavior. Not only should we examine a variety of causal mechanisms for demographic phenomena; we also should consider the varying utility of those mechanisms across different social groups.