cssi/SciSciGPT-SciSciNet huggingface dataset:
Surface roughening during low-temperature Si epitaxial growth on singular vs vicinal Si(001) substrates

The evolution of surface roughness on epitaxial Si films grown at 300 \ifmmode^\circ\else\textdegree\fi{}C by ultrahigh vacuum ion-beam sputter deposition onto nominally singular, [100]-, and [110]-miscut Si(001) is inconsistent with conventional scaling and hyperscaling laws for kinetic roughening. Unstable growth leading to the formation of mounds separated by a well-defined length scale is observed on all substrates. Contrary to previous high-temperature growth results, the presence of steps during deposition at 300 \ifmmode^\circ\else\textdegree\fi{}C increases the tendency toward unstable growth resulting in a much earlier development of mound structures and larger surface roughness on vicinal substrates. \textcopyright{} 1996 The American Physical Society.
Structure of the Pre-Parasitic Juveniles of Filipjevimermis Leipsandra and Some Other Mermithidae (Nematodea)

The structure of the pre-parasitic juveniles of the following Mermithidae (Nematodea) was studied and compared : Filipjevimermis leipsandra Poinar & Welch, Hydromermis contorta (Kohn), Hydromermis conopophaga Poinar, Gastromermis viridis Welch, Reesimermis nielseni Tsai & Grundmann, and Mermis nigrescens Duj. F. leipsandra was also examined with the electron microscope. Although the post-parasitic and adult stages of mermithids show morphological modifications resulting from a parasitic mode of life, the pre-parasitic juveniles strikingly resemble free-living nematodes. Findings here indicate that the mermithids are a phylogenetically diverging group and that certain characters of the pre-parasitic juveniles can be used for specific and generic determination.
Development of cross-resistance between heat and cisplatin or hydroxyurea treatments in FaDu squamous carcinoma cells.

Abstract Background. Induction of hyperthermia by radiofrequency ablation is gaining popularity in treating a variety of solid tumors. This study examined an impact of sublethal heat treatment interacted with chemotherapeutic drugs on the survival of head and neck squamous carcinoma cells using in vitro model. Materials and methods. FaDu cells were subjected to heat treatment at 42°C or 45°C for 15 min either before or after exposure to cisplatin or hydroxyurea. The survival of cells was determined by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide assay. The RNA and protein levels of various heat shock proteins were examined by reverse transcription polymerase chain reaction and Western blot analysis, respectively. Cell cycle progression was analyzed by flow cytometry with propidium iodide staining. Results. FaDu cells preheated to 45°C exhibited an increased resistance to hydroxyurea but not to cisplatin. The heat treatment resulted in induction of HSP70 expression at transcript and protein levels, but there was no change in expression of HSP90β and HSP27. After heat treatment, cells accumulated in S-phase at 3 h and proceeded to G 2 /M phase at 24 h. When cells pre-exposed to drugs for 24 h, the cisplatin-treated cells exhibited a higher thermotolerance than the hydroxyurea-treated cells at heat treatment of 45°C. Cisplatin and hydroxyurea caused cells to accumulate in S-phase and increased the protein expression of HSP27 but not HSP90β and HSP70. Conclusion. FaDu cells surviving the heat treatment expressed HSP70 and disrupted cell cycle progression, which resulted in developing a resistance to subsequent hydroxyurea treatment. However, the heat treatment did not have an effect on the sensitivity to cisplatin. In the reversed procedure, pre-exposure to hydroxyurea and cisplatin resulted in developing a thermotolerance.
Meeting the Needs of Diverse Student Populations: Comprehensive Professional Development in Science, Math, and Technology for Teachers of Students With Disabilities

Professional development for teachers has become a key component for reform in teaching, learning, and curriculum change. This report describes a model of professional development designed to improve the skills and knowledge of teams of special education and regular education teachers in science, mathematics, and technology instruction. The comprehensive model included summer and academic year content and methodology-focused workshops and summer “practician” experiences. It was designed to link those factors impacting teacher practices and interventions with teachers' beliefs in instruction. The training component for teachers included opportunities for collaborative teaching, upgrading knowledge of math and science subject matter, and identifying, integrating, and practicing alternative approaches for teaching science and math that address the needs of special education students, with a focus on techniques for adapting instruction to specific disabilities. The program led to development of coping skills and persistence in the teaching of science and math for all students. As a result, strong efficacy expectations have been developed through repeated experiences of success with children in a classroom environment. Remaining issues still to be addressed include classroom management, teaching in a heterogeneous classroom, and further improvement of content expertise of teachers.
Changes in aphasic discourse after contrasting treatments for anomia

Background: Discourse analysis is a key element in determining treatment effects. However, it is extremely labour intensive, requiring in‐depth knowledge of linguistics and aphasiology; thus, it is often neglected in the analysis of treatment outcomes. A clinically practical method of discourse analysis would be beneficial for evaluation and determination of treatment efficacy. Aims: The current study investigates changes in discourse content following contrasting treatments for anomia using grammatical analysis. In addition, we pilot the use of a new information measure. Methods & Procedures: We compare discourse changes after a gestural + verbaltreatment and a semantic‐phonologic treatment for nouns and verbs on two groups of individuals with aphasia. Analyses compared discourse samples from 14 participants taken at baseline, post‐phase 1, and post‐phase 2. In addition to traditional measures such as number of nouns, verbs, and sentence types, a new measure of information is introduced, the Utterance wi...
GENMARK: Parallel gene recognition for both DNA strands

Abstract The problem of predicting gene locations in newly sequenced DNA is well known but still far from being successfully resolved. A novel approach to the problem based on the frame dependent (non-homogeneous) Markov chain models of protein-coding regions was previously suggested. This approach is, apparently, one of the most powerful “search by content” methods. The initial idea of the method combines the specific Markov models of coding and non-coding region together with Bayes' decision making function and allows easy generalization for employing of higher order Markov chain models. Another generalization which is described in this article allows the analysis of both DNA strands simultaneously. Currently known gene searching methods perform the analysis of the two DNA strands in turn, one after another. In doing this all the known methods fail in the sense that they generate false (artifactual) prediction signals for the given strand when the real coding region is located on the complementary DNA strand. This common drawback is avoided by employing the Bayesian algorithm which uses an additional non-homogeneous Markov chain model of the “shadow” of the coding region—the sequence which is complementary to the protein-coding sequence.
Theory, Research, and Application: Some Critical Issues for Thanatology

The current status of thanatological research is illustrated by an examination of a) the most popular line of empirical investigation, and b) the most sweeping theoretical approach yet proposed. Su...
The Effect of Environmental Disclosure Requirements on Willingness to Pay for Residential Properties in Borderlands Community

Objective. This study examines the effect of environmental information disclosure requirements on future real estate transactions. The setting involves pollution from a concrete products and quarrying site near a largely Hispanic, residential community. Methods. The survey-based contingent valuation (CV) method is used to test the hypothesis that a split-sample treatment for an information disclosure requirement with a potentially negative affective quality will reduce the willingness to pay (WTP) of potential buyers for a typical property. Results. Results indicate that the information disclosure treatment reduces WTP, and that this effect is significantly exacerbated when the surveys are conducted in Spanish. Conclusions. In addition to identifying significant reductions in the WTP of potential home buyers, our findings demonstrate the importance of cultural and regional considerations for how information disclosure requirements are conducted in real estate transactions. Future CV studies should also consider Spanish-language options in applications involving significant Hispanic populations.
Exporting workfare/importing welfare-to-work: exploring the politics of Third Way policy transfer

Abstract The paper presents a critical analysis of ‘policy transfers’ in the field of welfare-to-work or ‘workfare’ programming, focusing on recent experiences in the United Kingdom and the United States. In the 1990s, work-based welfare reform has been established as a policy orthodoxy, a social-policy counterpart to ‘flexible’ modes of labour-market governance. Increasingly, this is celebrated as a paradigmatic example of ‘Third Way’ policy-making. While it has become something of a cliche that British welfare policy has been ‘Americanised’ in recent years, detailed analysis of the policy formation and development process around the Labour Government's New Deal programme for the young unemployed reveals that this has indeed been a sphere of intensive and multi-lateral policy transfers. Categorically, this does not mean that some simple process of policy ‘convergence’ is underway, as the form and function of such policies is prone to change as they are translated and re-embedded within and between different institutional, economic and political contexts (at the local and national scales). Rather paradoxically, while the turnover of the policy-making cycle seems to be accelerating in the field of welfare-to-work — as implementation schedules are intensified, as ‘reform’ becomes a systemic condition, and as extra-local policy learning and emulation is normalised — the effectiveness of policies and programmes remains stubbornly dependent on local economic and institutional conditions — as ‘successful’ programmes remain very difficult to replicate in other locations, as tendentially-decentralising policy regimes exhibit growing spatial unevenness, and as local labour market conditions continue to exert an inordinate influence on programme outcomes. Policy-makers on both sides of the Atlantic are increasingly pinning their hopes on decentralised modes of policy delivery as a means of animating (supposedly latent) innovatory capacity at the local level, despite the growing evidence that sustainable solutions to the problems of unemployment and poverty lie outside the neoliberal policy agenda of market-orientated workfare.
The Effect of Pressure and of Controlled Stretch on the Luminescent Properties of 9,10-Bis(phenylethynyl) Anthracene‡

The luminescence properties of 9,10-bis(phenylethynyl) anthracene have been investigated in solid poly(vinyl acetate) (PVAc) and a copolymer of vinyl chloride (VCl) and vinyl acetate (VAc) as a function of pressure to 65 kbar and of controlled stretch over a range of up to 4 times the original length using the 400 nm line of a frequency-doubled Ti:sapphire laser. With increasing pressure, the intensity (corrected for the absorption at 400 nm) decreases significantly and there is a distinct change in peak shape in the region of 20−40 kbar. In this region, the lifetime increases from 3.5 ± 0.2 to 4.0 ± 0.2 ns. The result can be explained on the basis of the analysis of Levitus and Garcia-Garibay. The red shift of the absorption peak is equivalent to a blue shift of the excitation laser, which results in excitation of a different polarization of the molecule. Up to a stretch of 2, the controlled stretch produces an increase of intensity for laser excitation polarized in the direction of stretch and a decreas...
Combination therapy utilizing shRNA knockdown and an optimized resistant transgene for rescue of diseases caused by misfolded proteins

Molecular knockdown of disease proteins and restoration of wild-type activity represent a promising but challenging strategy for the treatment of diseases that result from the accumulation of misfolded proteins (i.e., Huntington disease, amyotrophic lateral sclerosis, and α-1 antitrypsin deficiency). In this study we used alpha-1 antitrypsin (AAT) deficiency with the piZZ mutant phenotype as a model system to evaluate the efficiency of gene-delivery approaches that both silence the piZZ transcript (e.g., shRNA) and restore circulating wild-type AAT expression from resistant codon-optimized AAT (AAT-opt) transgene cassette using adeno-associated virus (AAV) vector delivery. After systemic injection of a self-complimentary AAV serotype 8 (scAAV8) vector encoding shRNA in piZZ transgenic mice, both mutant AAT mRNA in the liver and defected serum protein level were inhibited by 95%, whereas liver pathology, as monitored by dPAS and fibrosis staining, reversed. To restore blood AAT levels in AAV8/shRNA-treated mice, several strategies to restore functional AAT levels were tested, including using AAV AAT-opt transgene cassettes targeted to muscle and liver, or combination vectors carrying piZZ shRNA and AAT-opt transgenes separately, or a single bicistronic AAV vector. With these molecular approaches, we observed over 90% knockdown of mutant AAT with a 13- to 30-fold increase of circulating wild-type AAT protein from the shRNA-resistant AAT-opt cassette. The molecular approaches applied in this study can simultaneously prevent liver pathology and restore blood AAT concentration in AAT deficiencies. Based on these observations, similar gene-therapy strategies could be considered for any diseases caused by accumulation of misfolded proteins.
Recent fluid deformation closure for velocity gradient tensor dynamics in turbulence: Timescale effects and expansions

Abstract In order to model pressure and viscous terms in the equation for the Lagrangian dynamics of the velocity gradient tensor in turbulent flows, Chevillard & Meneveau [L. Chevillard, C. Meneveau, Lagrangian dynamics and geometric structure of turbulence, Phys. Rev. Lett. 97 (174501) (2006) 1–4] introduced the Recent Fluid Deformation closure. Using matrix exponentials, the closure allows us to overcome the unphysical finite-time blow-up of the well-known Restricted Euler model. However, it also requires the specification of a decorrelation timescale of the velocity gradient along the Lagrangian evolution, and when the latter is chosen too short (or, equivalently, the Reynolds number is too high), the model leads to unphysical statistics. In the present paper, we explore the limitations of this closure by means of numerical experiments and analytical considerations. We also study the possible effects of using time-correlated stochastic forcing instead of the previously employed white-noise forcing. Numerical experiments show that reducing the correlation timescale specified in the closure and in the forcing does not lead to a commensurate reduction of the autocorrelation timescale of the predicted evolution of the velocity gradient tensor. This observed inconsistency could explain the unrealistic predictions at increasing Reynolds numbers. We perform a series expansion of the matrix exponentials in powers of the decorrelation timescale, and we compare the full original model with a linearized version. The latter is not able to extend the limits of applicability of the former but allows the model to be cast in terms of a damping term whose sign gives additional information about the stability of the model as a function of the second invariant of the velocity gradient tensor.
Paying for God's Work: A Rights-Based Examination of Faith-Based NGOs in Romania

This paper examines issues of democratic accountability as they apply to faith-based organizations cooperating in international developmental efforts, with a specific focus on the freedom of expression rights of nonprofit organizations and the freedom of association rights of their clientele. Child welfare nongovernmental organizations (NGOs) in Romania are used as a case study for examining the issue. The paper begins with a discussion of NGO-government partnerships in service provision in international development, and examines the ethical concerns surrounding church-state separation as applied to nonprofits in the United States and in the context of foreign aid. The literature analysis is complimented by empirical evidence from the Romanian case, using data gathered in a qualitative study exploring the role of NGOs as social service providers and policy advocates. The paper concludes by discussing the particular role that bureaucratic discretion and power plays in protecting the freedom of association rights of clientele in Romania.
Approximate Bridging Relations in the Transitional Regime between Continuum and Free-Molecule Flows

Approximate bridging relations for aerodynamic quantities in the transitional regime between free-molecule and continuum flows are developed. Equations are presented for heat transfer, surface shear, and drag, and are proposed for lift and pressure distribution. The equations can be considered as semiempirical. They are derived from models based on simplified kinetic theory; the structure of the equations is such that they are asymptotically correct at the free-molecule and continuum extremes, and this tends to place bounds on errors resulting from a simplified analysis. The equations presented are essentially for blunt bodies; that may be used as engineering approximations in many cases for which more rigorously developed specific relations do not exist.
Demography of the leafminer parasitoid Ganaspidium utilis Beardsley (Hymenoptera: Eucoilidae) at different temperatures

Abstract Demographic parameters, reproductive pattern, and heterogeneity for the leafminer parasitoid Ganaspidium utilis Beardsley (Hymenoptera: Eucoilidae) were determined in the laboratory at 16, 27, and 32°C using Liriomyza trifolii (Burgess) with “Henderson” bush lima beans as the host. Development and progeny production did not occur at 16°C. Mean developmental time was significantly shorter (13.2 days) at 32°C than at 27°C (18.4 days). Preadult cumulative survival rates at 27°C (62%) and 32°C (43%) were significantly different. Male and female longevities were similar. Adult G. utilis lived a maximum of 23 days at 16°C, 13 days at 27°C, and 8 days at 32°C. Total mean lifetime progeny production per female G. utilis ranged from 68.50 progeny at 32°C to 115.10 progeny at 27°C. Heaviest progeny production occurred during Days 2 and 3 of a female's life at 32 and 27°C, respectively. Of the total progeny produced, the female percentage ranged from 47 at 27°C to 49 at 32°C. Mean generation time was 15 days at 32°C and 21 days at 27°C. Intrinsic rate of increase varied from 0.19 at 27°C to 0.23 at 32°C. In the stable age distribution, egg percentage was highest (56–58) followed by larval stage (36–37), whereas pupal and adult stages each only represented 3 to 4. Age-by-parity relations demonstrated that timing and magnitude of reproduction were influenced by temperature.
Democratic Politics and Survey Research

Democratically inspired critics identify a number of problems with the contemporary identification of survey research and public opinion. Surveys are said to normalize or rationalize opinion, to pr...
The Role of the Representative: Some Empirical Observations on the Theory of Edmund Burke *

The problem of representation is central to all discussions of the functions of legislatures or the behavior of legislators. For it is commonly taken for granted that, in democratic political systems, legislatures are both legitimate and authoritative decision-making institutions, and that it is their representative character which makes them authoritative and legitimate. Through the process of representation, presumably, legislatures are empowered to act for the whole body politic and are legitimized. And because, by virtue of representation, they participate in legislation, the represented accept legislative decisions as authoritative. But agreement about the meaning of the term “representation” hardly goes beyond a general consensus regarding the context within which it is appropriately used. The history of political theory is studded with definitions of representation, usually embedded in ideological assumptions and postulates which cannot serve the uses of empirical research without conceptual clarification.
Differential effects of x-rays and high-energy 56Fe ions on human mesenchymal stem cells.

Purpose Stem cells hold great potential for regenerative medicine, but they have also been implicated in cancer and aging. How different kinds of ionizing radiation affect stem cell biology remains unexplored. This study was designed to compare the biological effects of X-rays and of high–linear energy transfer (LET) 56 Fe ions on human mesenchymal stem cells (hMSC). Methods and Materials A multi-functional comparison was carried out to investigate the differential effects of X-rays and 56 Fe ions on hMSC. The end points included modulation of key markers such as p53, cell cycle progression, osteogenic differentiation, and pathway and networks through transcriptomic profiling and bioinformatics analysis. Results X-rays and 56 Fe ions differentially inhibited the cell cycle progression of hMSC in a p53-dependent manner without impairing their in vitro osteogenic differentiation process. Pathway and network analyses revealed that cytoskeleton and receptor signaling were uniquely enriched for low-dose (0.1 Gy) X-rays. In contrast, DNA/RNA metabolism and cell cycle regulation were enriched for high-dose (1 Gy) X-rays and 56 Fe ions, with more significant effects from 56 Fe ions. Specifically, DNA replication, DNA strand elongation, and DNA binding/transferase activity were perturbed more severely by 1 Gy 56 Fe ions than by 1 Gy X-rays, consistent with the significant G2/M arrest for the former while not for the latter. Conclusions 56 Fe ions exert more significant effects on hMSC than X-rays. Since hMSC are the progenitors of osteoblasts in vivo, this study provides new mechanistic understandings of the relative health risks associated with low- and high-dose X-rays and high-LET space radiation.
Materials in Spine Surgery

A wide variety of surgical procedures ranging from laminectomy to vertebral body resection are used to restore spinal function. Accordingly, a wide range of man-made and natural materials are used as supplements to improve the long term success rate of these procedures and patient comfort. Requirements for the materials used in spine surgery are similar to other applications; tissue compatibility in terms of mechanical, chemical and pharmacological requirements. The requirements may change as the tissue heals with time. It is imperative that the materials be "dynamic" in their abilities to respond to the changing environmental needs. Due to technical innovations in the area of biomaterials, newer materials have been proposed for the spinal surgery. Graft materials (fat, allo-, auto, BMP), metals, polymers, ceramics, and composites are used to restore spinal function.
Clinical Performance of an Extraction Calcitonin Radioimmunoassay

An extraction radioimmunoassay of calcitonin (CT) was used to replace the direct radioimmunoassay, in which false-negative results (normal basal CT values but above normal ["positive"] results after pentagastrin stimulation) occurred in 26 to 30% of cases. During the past 6 years, 170 pentagastrin stimulation tests were performed in 135 patients at our institution. We reviewed the results to determine whether extraction radioimmunoassay yielded improvement. Of the 135 patients, 6 (4.4%) had indeterminate results of pentagastrin stimulation tests that consisted of normal basal levels but increased values after pentagastrin stimulation, a considerable improvement over the results with direct assay. Six other patients had indeterminate results of pentagastrin testing—increased basal CT levels but normal values after pentagastrin stimulation. Indeterminate results of pentagastrin tests occurred primarily in postoperative or preoperative patients with a family history of medullary thyroid carcinoma (MTC). The reasons for the indeterminate results were unclear, as was their importance as a prelude to disease, but two preoperative patients with indeterminate results eventually had positive results and were found to have MTC at operation. We conclude that extraction radioimmunoassay is more reliable than direct radioimmunoassay for the diagnosis of MTC. Determination of a basal CT value and of the CT value after pentagastrin stimulation is sufficient for diagnosing MTC.
Surgical treatment of substernal thyroid disease

Abstract The thyroid surgeon must have a full understanding of the anatomy and surgical approaches to the mediastinum. Although most benign substernal goiters may be removed by a transcervical approach, the surgeon needs to know indications for transclavicular and median sternotomy approaches. When there is direct evidence of extension of thyroid cancer into the mediastinum, the possibility of median sternotomy should be considered. This is certainly mandated when disease extends to the inferior mediastinum. Superior mediastinal node dissection is usually easy to approach transcervically. Unilateral extension of the disease may be accessed readily with a transclavicular approach for most cases. Careful dissection of the recurrent laryngeal nerve as well as parathyroids is essential to diminish postoperative morbidity. The morbidity is a reflection of the experience and technical skills of the surgeon as well as the extent of the disease. The best results for resection of substernal thyroid disease are obtained by the experienced thyroid surgeon, not the occasional operator.
The Sliding Behaviors of Copper Alloys

Abstract : The unlubricated behaviors of a number of copper alloys and especially their metal transfers and scuffing tendencies were investigated on steel, chromium electroplate, and tantalum using a specially designed pin-on- disk friction and wear machine. This machine limited the sliding time to about 100 msec. It was not possible to correlate metal transfer, scuffing (rough deposits), or friction with the properties of the alloys. There was a correlation of wear with hardness for similar alloys with higher hardness alloys having lower wear. The effect of hardness was different for different mating surfaces. The data from aluminum bronze and the welded overlay rotating band materials investigated did not fall into this correlation. This could not be attributed to a special microstructure or to crystalline orientation in the case of the welded overlay band materials. Mutual solubility of the pin and disk metals and relative position in the periodic table also did not control metal transfer and scuffing with the copper alloys investigated. While position in the periodic table is identical and mutual solubilities are certainly very similar for most of the copper alloys, there were great differences in metal transfer and scuffing. While there was a tendency for more transfer to occur at higher wear rates, heavy and very heavy transfer do occur even at very low rates. Heavy and very heavy transfer were not usually associated with high wear and rough deposits were not usually associated with high wear and heavy transfer. The first step in wear was not transfer to the mating surfaces. In addition, small amounts of iron in the copper alloys did not result in scuffing and high metal transfer even when sliding on steel.
Finding the Transition State of Quasi-Barrierless Reactions by a Growing String Method for Newton Trajectories: Application to the Dissociation of Methylenecyclopropene and Cyclopropane†

A method for finding a transition state (TS) between a reactant minimum and a quasi-flat, high dissociation plateau on the potential energy surface is described. The method is based on the search of a growing string (GS) along reaction pathways defined by different Newton trajectories (NT). Searches with the GS-NT method always make it possible to identify the TS region because monotonically increasing NTs cross at the TS or, if not monotonically increasing, possess turning points that are located in the TS region. The GS-NT method is applied to quasi-barrierless and truly barrierless chemical reactions. Examples are the dissociation of methylenecyclopropene to acetylene and vinylidene, for which a small barrier far out in the exit channel is found, and the cycloaddition of singlet methylene and ethene, which is barrierless for a broad reaction channel with Cs-symmetry reminiscent of a mountain cirque formed by a glacier.
Staging laparotomy with splenectomy for Hodgkin's disease: The Stanford experience

The results of 825 staging laparotomies performed by surgeons at Stanford University Hospital are presented. The clinical stage was changed as a result of laparotomy in 43.2% of cases. Preoperative lymphangiography proved accurate in 78–80% of cases. In 321 patients (38.9%) the test results for the spleen were positive, and in161 (50.2%) of these, the spleen was the only positive tissue sampled. Major complications occurred in 9.6% of cases; most were wound and upper respiratory infections. The results of laparotomy have identified a subgroup of stage NIA patients who benefit from early systemic chemotherapy. Staging laparotomy with splenectomy has proven to be a useful and safe clinical research tool and has been one of the major factors in increasing survival from Hodgkin's disease.
Solution of the quasispecies model for an arbitrary gene network

In this paper, we study the equilibrium behavior of Eigen's quasispecies equations for an arbitrary gene network. We consider a genome consisting of $N$ genes, so that the full genome sequence $\ensuremath{\sigma}$ may be written as $\ensuremath{\sigma}={\ensuremath{\sigma}}_{1}{\ensuremath{\sigma}}_{2}\ensuremath{\cdots}{\ensuremath{\sigma}}_{N}$, where ${\ensuremath{\sigma}}_{i}$ are sequences of individual genes. We assume a single fitness peak model for each gene, so that gene $i$ has some ``master'' sequence ${\ensuremath{\sigma}}_{i,0}$ for which it is functioning. The fitness landscape is then determined by which genes in the genome are functioning and which are not. The equilibrium behavior of this model may be solved in the limit of infinite sequence length. The central result is that, instead of a single error catastrophe, the model exhibits a series of localization to delocalization transitions, which we term an ``error cascade.'' As the mutation rate is increased, the selective advantage for maintaining functional copies of certain genes in the network disappears, and the population distribution delocalizes over the corresponding sequence spaces. The network goes through a series of such transitions, as more and more genes become inactivated, until eventually delocalization occurs over the entire genome space, resulting in a final error catastrophe. This model provides a criterion for determining the conditions under which certain genes in a genome will lose functionality due to genetic drift. It also provides insight into the response of gene networks to mutagens. In particular, it suggests an approach for determining the relative importance of various genes to the fitness of an organism, in a more accurate manner than the standard ``deletion set'' method. The results in this paper also have implications for mutational robustness and what C.O. Wilke termed ``survival of the flattest.''
Prolonging Survival by Reducing Arrhythmic Death: Pharmacologic Therapy of Ventricular Tachycardia and Fibrillation

Abstract Antiarrhythmic drug therapy of sustained ventricular tachyarrhythmias is undertaken to reduce arrhythmic symptoms, recurrences, and mortality. Ideally, reduction of arrhythmic death will reduce total mortality as well, although this may not hold true in the presence of competing risk. Whether, in fact, antiarrhythmic therapy actually reduces arrhythmic death remains uncertain in the absence of any placebo-controlled trials. Nonetheless, the following conclusions can be drawn from the Electrophysiologic Study versus Electrocardiographic Monitoring (ESVEM) trial, the Cardiac Arrest Study Hamburg (CASH), and the Cardiac Arrest in Seattle: Conventional versus Amiodarone Drug Evaluation (CASCADE) study, as well as a β blocker study by Steinbeck et al: (1) class I antiarrhythmics are less effective than amiodarone or sotalol for the prevention of recurrent sustained ventricular tachycardia/ventricular fibrillation; (2) sympathetic inhibition as a component of the antiarrhythmic regimen may strongly contribute to mortality reduction; and (3) the respective roles of antiarrhythmic drugs, implantable devices, and the concurrent use of both are in a state of flux, awaiting results of randomized controlled clinical trials.
The estimation of stochastic cost‐quantity frontiers for discretionary cost and budgeted‐expenditure systems

Two alternative approximating functions for representing the unknown composite residual density function of a cost-quantity frontier are examined. The frontier is one in which cost is regarded as preselected. This is appropriate for public sector economics and discretionary cost situations. One function requires the estimation of a single distribution parameter, whereas the other makes no a priori assumption on the shape of the density function.
Empirical Relationship Between Lengthening an Anterior Cruciate Ligament Graft and Increases in Knee Anterior Laxity: A Human Cadaveric Study

Lengthening of an anterior cruciate ligament (ACL) graft construct can occur as a result of lengthening at the sites of tibial and/or femoral fixation and manifests as an increase in anterior laxity. Although lengthening at the site of fixation has been measured for a variety of fixation devices, it is difficult to place these results in a clinical context because the mathematical relationship between lengthening of an ACL graft construct and anterior laxity is unknown. The purpose of our study was to determine empirically this relationship. Ten cadaveric knees were reconstructed with a double-looped tendon graft. With the knee in 25 degrees of flexion, the position of the proximal end of the graft inside the femoral tunnel was adjusted by moving the femoral fixation device until the anterior laxity at an applied anterior force of 134 N matched that of the intact knee. In random order, the graft construct was lengthened 1, 2, 3, 4, and 5 mm by moving the femoral fixation device distally along the femoral tunnel and anterior laxity was measured. The increase in the length of the graft construct was related to the increase in anterior laxity by a simple linear regression model. Lengthening the graft construct from 1 to 5 mm caused an equal increase in anterior laxity (slope=1.0 mmmm, r(2)=0.800, p<0.0001). Because an anterior laxity increase of 3 mm or greater in a reconstructed knee is considered unstable clinically and because many fixation devices in widespread use clinically allow 3 mm or greater of lengthening in in vitro tests, our empirical relationship indicates that lengthening at the site of fixation probably is an important cause of knee instability following ACL reconstructive surgery. Our empirical relation also indicates that an important criterion in the design of future fixation devices is that lengthening at the sites of fixation in in vitro tests should be limited to less than 3 mm.
Parables, Storytelling, and Teacher Education

Arguing that teacher education has become rule bound, even in the use of teaching narratives and cases, and for the need to challenge beginning teachers’ conceptions of teaching and learning, the author suggests parables as promising means for enlivening teacher education and for stretching understanding. After defining parable, the author presents an analysis of three examples—The Storm, The Sower, and The Fish and the Turtle—to illustrate some of the rich interpretative possibilities they offer for thinking critically and imaginatively about teaching and learning and for generating fresh educational metaphors useful for guiding thought and action.
Operational approaches to managing forests of the future in Mediterranean regions within a context of changing climates

Many US forest managers have used historical ecology information to assist in the development of desired conditions. While there are many important lessons to learn from the past, we believe that we cannot rely on past forest conditions to provide us with blueprints for future management. To respond to this uncertainty, managers will be challenged to integrate adaptation strategies into plans in response to changing climates. Adaptive strategies include resistance options, resilience options, response options, and realignment options. Our objectives are to present ideas that could be useful in developing plans under changing climates that could be applicable to forests with Mediterranean climates. We believe that managing for species persistence at the broad ecoregion scale is the most appropriate goal when considering the effects of changing climates. Such a goal relaxes expectations that current species ranges will remain constant, or that population abundances, distribution, species compositions and dominances should remain stable. Allowing fundamental ecosystem processes to operate within forested landscapes will be critical. Management and political institutions will have to acknowledge and embrace uncertainty in the future since we are moving into a time period with few analogs and inevitably, there will be surprises.
Communication in Mind, Brain, and Education: Making Disciplinary Differences Explicit

Difficulties in communication within Mind, Brain, and Education (MBE) can arise from several sources. One source is differences in orientation among the areas of research, policy, and practice. Another source is lack of understanding of the entrenched and unspoken differences across research disciplines in MBE—that is, recognition that research in MBE comes from many diverse disciplines, rather than some monolithic entity. A third challenge to communication in MBE arises from the nature of studying the mind and brain; we address the different levels of analysis in mind-brain research. Throughout our article, we emphasize that recognizing these differences—across areas (research, practice, and policy), disciplines, and levels of analysis—and making them explicit can facilitate effective communication in MBE. We illustrate these concepts with examples from the study of reading disorders across several disciplines. A major challenge to progress in Mind, Brain, and Education (MBE) is effective communication. Why is effective commu- nication in MBE so difficult? We believe there are several reasons, some intrinsic to any interdisciplinary endeavor, and others specific to the disciplines and fields involved in MBE. In this article, we attempt to identify some of these obstacles, and, wherever possible, to suggest solutions. As the field of education spans the realms of research, prac- tice, and policy, we first address how communication problems may arise from misunderstandings among these three areas, each of which has its own goals, constraints, rules for use of evidence, and role for values and ideologies.
Quantification of chromatographic effects of vitamin B supplementation in urine and implications for hydration assessment.

Changes in body water elicit reflex adjustments at the kidney, thus maintaining fluid volume homeostasis. These renal adjustments change the concentration and color of urine, variables that can, in...
The effect of rubber particle size on the impact properties of high impact polystyrene (HIPS) blends

The impact fracture of nominally identical high impact polystyrene resins having different and well-characterized rubber particle size distributions is discussed. A numerical model for craze termination is presented and its predictions are compared with experimental data. An alternative explanation for the observed effect of particle size on fracture energy is considered.
Measuring college students' motives behind prepartying drinking: development and validation of the prepartying motivations inventory.

article i nfo Drinking motives are vital in identifying risk factors and better understanding alcohol-related outcomes. However, context-specific motivations could provide greater motivational perspective on high-risk context- specific alcohol use behaviors such as prepartying (consuming alcohol prior to attending one's intended destina- tion) than general alcohol motivations. In the current study, students' open-ended responses to reasons for pre- partying were collected from a large diverse sample (n=2497), and the most commonly offered reasons were used to create a prepartying motivations inventory (PMI) that was then administered to a different sample (n=1085). A split-half validation procedure was used for the purpose of evaluating the PMI's factor structure. Exploratory and confirmatory factor analyses yielded a final 16-item measure consisting of four distinct, but inter-related, factors: Interpersonal Enhancement, Situational Control, Intimate Pursuit, and Barriers to Con- sumption. Internal consistency reliability, discriminant validity, and criterion-related validity were empirically demonstrated. Results support the notion that individuals preparty for a variety of reasons that are distinct fromgeneral motives.Researchers are encouragedtouse thePMIinfutureresearchwithyoungadultstoprovide further understanding of prepartying behavior and its psychosocial correlates.
FOS-LIKE IMMUNOREACTIVITY IN CENTRAL AUDITORY NEURONS OF THE MOUSE

Fos-like immunoreactivity was used to study sound-induced activation of neurons in the auditory brainstem. Immunoreactivity was assayed with a polyclonal antibody to Fos. In response to 6-kHz tone bursts, the pattern of staining was a band of immunoreactive neurons positioned at the tonotopically appropriate position within the cochlear nucleus and the inferior colliculus. The band was narrow at low sound pressure levels but wider along the tonotopic axis at higher sound levels. In response to noise bursts, the pattern was broader and often extended throughout the auditory nuclei. Often within this broad pattern were “sub-bands” of immunostained neurons, interspersed with bands of unstained neurons. With increasing sound pressure levels above 35--55 dB, the number of Fos-like immunoreactive neurons increased for the cochlear nucleus, superior olivary complex, and inferior colliculus. In the cochlear nucleus and inferior colliculus, the stained cells were small, and hence their activity would be difficult to sample in electrophysiological studies. In the medial nucleus of the trapezoid body, the stained neurons had larger somata and other characteristics of principal cells. Anesthesia with Nembutal or Avertin, but not with ketamine or urethane, decreased the number of Fos-like immunoreactive neurons in the cochlear nucleus. The different anesthetics produced more variable results in the inferior colliculus. In anesthetized, monaurally stimulated animals, the presence of staining in the contralateral cochlear nucleus indicates that some Fos-like immunoreactivity may be mediated by descending or commissural systems. These observations indicate that Fos assays are useful for studying the pattern of neuronal activation in the auditory system and may also be useful in studying the descending auditory pathways. © 1995 Wiley-Liss, Inc.
Reliability of Self-Reported Drug Use and Urinalysis in the Drug Use Forecasting System

The Drug Use Forecasting (DUF) program was initiated by the National Institute of Justice to estimate the extent of psychoactive drug use primarily among arrestees charged with nondrug felonies. Because of its importance as one of the major data sources for drug use in criminal justice populations, it is important to assess the reliability of the self-report as contrasted with urinalysis data provided. This report is based on a study of 3,297 male and 913 female arrestees in the city of Cleveland. Overall reliability among 8 of the 10 drug categories tested for was high mainly due to the low rates of use of these drugs in the population. However, among the two most frequently used drug categories (cocaine and marijuana), there was significant discrepancy between self-report and urine results with over half of those who tested positive for either drug denying any use within the past 72 hours. The implications of these results are discussed.
Multimodal treatment for childhood attention-deficit/hyperactivity disorder

Attention-deficit/hyperactivity disorder (ADHD) is one of the most common childhood disorders, characterized by developmentally inappropriate levels of inattention and/or hyperactivity/impulsivity. These core symptoms lead to impairment in home, school and peer contexts. Evidence-based treatments for ADHD include medication management (generally with stimulant medications), behavioral interventions (such as behavioral parent training, school consultation, and direct contingency management), or the combination of pharmacological and behavioral approaches. This review outlines each of these treatment strategies, reviews the rationale and evidence base currently existing for the use of multimodal rather than unimodal treatments (i.e., medication or behavioral intervention alone), and discusses potential moderators of multimodal treatment efficacy, as well as future directions for research, that may better inform clinical practice.
Modeling the effects of nonlinear materials in ceramic chip capacitors for use in digital and analog applications

This paper describes a physics-based numerical approach to building circuit models for electronic components that are made of nonlinear dielectrics. The resulting models are intended for use in time-domain circuit simulators to assess the effects of material nonlinearity on the electrical performance of such components as discrete de-coupling and filter capacitors that are used in digital and analog circuits. A 3-D electrostatic field solver is modified to take into account the nonlinear field dependence of the dielectric material and is employed to calculate the Q-V curve for any capacitive structure. Subsequently, a time integration method (similar to that used in SPICE) is utilized to devise an appropriate time-stepping algorithm for the current-charge relationship of a nonlinear capacitor that can be used to simulate its time-domain electrical characteristics. Sample results are provided to illustrate the methodology and the effects of the material nonlinearity on the performance of the capacitor.
MICE: Multiple-Peak Identification, Characterization, and Estimation

MICE--multiple-peak identification, characterization, and estimation--is a procedure for estimating a lower bound of the number of frequency peaks and for estimating the frequency peak parameters. The leading application is protein structure determination using nuclear magnetic resonance (NMR) experiments. NMR frequency data are multiple-peak data, where each frequency peak corresponds to two connected atoms in the three-dimensional protein structure. We analyze the NMR frequency data through a series of steps: a preliminary step for separating the signal from the background followed by identification of local maxima up to a noise-level-dependent threshold, estimation of the frequency peak parameters using an iterative algorithm, and detection of mixtures of peaks using hypothesis testing.