cssi/SciSciGPT-SciSciNet huggingface dataset:
Conditional Moment Closure Schemes for Studying Stochastic Dynamics of Genetic Circuits

Inside individual cells, stochastic expression drives random fluctuations in gene product copy numbers, which corrupts functioning of both natural and synthetic genetic circuits. Dynamic models of genetic circuits are formulated stochastically using the chemical master equation framework. Since obtaining probability distributions can be computationally expensive in these models, noise is typically investigated through lower-order statistical moments (mean, variance, correlation, skewness, etc.) of mRNA/proteins levels. However, due to the nonlinearities in genetic circuits, this moment dynamics is typically not closed, in the sense that the time derivative of the lower-order statistical moments depends on high-order moments. Moment equations are closed by expressing higher-order moments as nonlinear functions of lower-order moments, a technique commonly referred to as moment closure. We provide a new moment closure scheme for studying stochastic dynamics of genetic circuits, where genes randomly toggle between transcriptionally active and inactive states. The method is based on conditioning protein levels on active states of genes and then expressing higher-order moments as functions of lower-order conditional moments. The conditional closure scheme is illustrated on different circuit motifs and found to outperform existing closure techniques. Rapid computation of stochasticity through closure methods will enable improved characterization and design of synthetic circuits that exhibit robust performance in spite of noisy expression of underlying genes.
C-Reactive Protein and Electron Beam Tomography

To the Editor: The study by Park et al1 demonstrates that electron beam tomography (EBT)–derived coronary calcium scores (CCS) are incremental in predicting cardiac risk, consistent with previous data. However, the authors downplay the prognostic power of CCS and elevate the value of C-reactive protein (CRP). They state, “CRP was a marginally significant predictor of MI [myocardial infarction] or coronary death ( P =0.09),” and, “CRP continued to contribute to the prediction of cardiovascular events ( P =0.07) for MI/coronary death.” Are the authors suggesting that their predetermined level of significance of 0.05 is not correct? Lowering the standard for statistical significance will only increase the odds of a random event being deemed “significant.” In this study, the predictive power of CCS constituted most of the risk prediction, as the relative risk of hard cardiac events increased from 1 to 4.9 with increasing calcium tertiles ( P =0.005). Increasing CRP among patients with low CCS raised the relative risk from 1.0 to 1.7 ( P =NS), and in the highest CCS tertile, from 4.9 to …
Do admitted patients held in the emergency department impact the throughput of treat-and-release patients?

Objective: To examine the impact of reducing ED “boarders” (through the use of a short-stay inpatient medicine unit) on the amount of time that treat-and-release patients spend in the ED. Methods: A retrospective analysis of hours spent in the ED was made at a university hospital teaching ED for treat-and-release patients in 4 clinical categories: chest pain, asthma exacerbation, sickle-cell crisis, and seizure. The average hours per patient spent in the ED during the 4-month intervals before (August-November 1993) and after (August-November 1994) the establishment of the short-stay medicine unit were compared. Data were analyzed using the 2-tailed, unpaired t-test. Results: This short-stay inpatient medicine unit received on average 135 patients per month from the ED, with an average length of stay of 2.4 days. The mean (±SD) number of admitted patients per day waiting in the ED >8 hours for an inpatient bed dropped from 9.6 ± 4.2, before the institution of this unit, to 2.3 ± 2.6. There was a significant reduction in the average number of hours spent in the ED by treat-and-release patients with chest pain (from 7.3 ± 6.0 to 5.5 ± 4.8 hr/patient, p c 0.001) and asthma exacerbation (from 5.0 ± 3.6 to 4.2 ± 2.9 hdpatient, p < 0.05), but not with sickle-cell crisis or seizure, after the implementation of the short-stay unit. Conclusion: Reducing the number of admitted patients waiting in the ED for inpatient beds, in this case by establishment of a short-stay medicine unit, is associated with a decrease in the interval that treat-and-release patients spend in the ED.
Maynard Smith & Parker's (1976) rule book for animal contests, mostly

Maynard Smith & Parker (1976 , Animal Behaviour , 24 , 159–175) offered animal behaviourists and behavioural ecologists a theoretical framework/guide to understanding animal behaviour in competitive contexts. In this essay I trace the influence of this ‘contest rule book’ from the factors that led the two researchers to develop a treatise on the logic of the asymmetric game to empirical tests of the contest rules and theoretical additions made to the basic model and its underlying assumptions. Over a thousand studies cite this paper directly and thousands more cite work spurred by the original paper. The vast majority of these studies confirm the evolutionarily stable strategy (ESS) predictions made by Maynard Smith & Parker. Theoretical and empirical deviations from EES can largely be explained by the need for further structuring of the analyses into subgames and investigation of less obvious asymmetries than apparent size and resource value. To date, much progress has been made in three areas of interest to behaviourists: (1) understanding of the strategic nature of contests between conspecifics over limited resources; (2) modelling developments that deal with how information about potential asymmetries is gained; and (3) evaluation of the question of honest signalling with specific reference to threat displays. Here, I propose suggestions for future work, much of which will either require collaboration with mathematicians, or require that students interested in animal behaviour obtain a strong foundation in biomathematics. My preference is for the latter strategy.
Formation of a Wrapped DNA–Protein Interface: Experimental Characterization and Analysis of the Large Contributions of Ions and Water to the Thermodynamics of Binding IHF to H′ DNA

To characterize driving forces and driven processes in formation of a large-interface, wrapped protein-DNA complex analogous to the nucleosome, we have investigated the thermodynamics of binding the 34-base pair (bp) H' DNA sequence to the Escherichia coli DNA-remodeling protein integration host factor (IHF). Isothermal titration calorimetry and fluorescence resonance energy transfer are applied to determine effects of salt concentration [KCl, KF, K glutamate (KGlu)] and of the excluded solute glycine betaine (GB) on the binding thermodynamics at 20 degrees C. Both the binding constant K(obs) and enthalpy Delta H degrees (obs) depend strongly on [salt] and anion identity. Formation of the wrapped complex is enthalpy driven, especially at low [salt] (e.g., Delta H(o)(obs)=-20.2 kcal x mol(-1) in 0.04 M KCl). Delta H degrees (obs) increases linearly with [salt] with a slope (d Delta H degrees (obs)/d[salt]), which is much larger in KCl (38+/-3 kcal x mol(-1) M(-1)) than in KF or KGlu (11+/-2 kcal x mol(-1) M(-1)). At 0.33 M [salt], K(obs) is approximately 30-fold larger in KGlu or KF than in KCl, and the [salt] derivative SK(obs)=dlnK(obs)/dln[salt] is almost twice as large in magnitude in KCl (-8.8+/-0.7) as in KF or KGlu (-4.7+/-0.6). A novel analysis of the large effects of anion identity on K(obs), SK(obs) and on Delta H degrees (obs) dissects coulombic, Hofmeister, and osmotic contributions to these quantities. This analysis attributes anion-specific differences in K(obs), SK(obs), and Delta H degrees (obs) to (i) displacement of a large number of water molecules of hydration [estimated to be 1.0(+/-0.2)x10(3)] from the 5340 A(2) of IHF and H' DNA surface buried in complex formation, and (ii) significant local exclusion of F(-) and Glu(-) from this hydration water, relative to the situation with Cl(-), which we propose is randomly distributed. To quantify net water release from anionic surface (22% of the surface buried in complexation, mostly from DNA phosphates), we determined the stabilizing effect of GB on K(obs): dlnK(obs)/d[GB]=2.7+/-0.4 at constant KCl activity, indicating the net release of ca. 150 H(2)O molecules from anionic surface.
A Strategic Plan for AACD's Future: The Precursors of ACA

Professional associations have recognized the value of long-term planning to assess the past and present, look into the future, and set specific goals to provide direction. Associations are affected by the myriad of events from their own community to global society, and it is easy to be pulled in many different directions. Associations have a compelling need to elicit member and environmental needs, set goals and objectives, and take strategic steps to realize these goals and objectives. It is the purpose of this article to provide, for the members of the American Counseling Association (ACA) and our archives, a description of strategic planning for the association. This process may be useful to future leaders and to various ACA entities (e.g., divisions, regions, state branches, corporate affiliates, committees) in creating their own strategic plans.
In vitro neurotoxic effects of 1 GeV/n iron particles assessed in retinal explants.

Abstract The heavy ion component of the cosmic radiation remains problematic to the assessment of risk in manned space flight. The biological effectiveness of HZE particles has yet to be established, particularly with regard to nervous tissue. Using heavy ions accelerated at the AGS of Brookhaven National Laboratory, we study the neurotoxic effects of iron particles. We exposed retinal explants, taken from chick embryos, to determine the dose response relationships for neurite outgrowth. Morphometric techniques were used to evaluate the in vitro effects of 1 GeV/a iron particles (LET 148 keV/μm). Iron particles produced a dose-dependent reduction of neurite outgrowth with a maximal effect achieved with a dose of 100 cGy. Doses as low as 10–50 cGy were able to induce reductions of the neurite outgrowth as compared to the control group. Neurite generation is a more sensitive parameter than neurite elongation, suggesting different mechanism of radiation damage in our model. These results showed that low doses/fluences of iron particles could impair the retinal ganglion cells' capacity to generate neurites indicating the highly neurotoxic capability of this heavy charged particle.
Contribution from various disciplines to measurement and evaluation in early childhood education

Abstract This discussion of actual and potential contributions from various discplines to measurement and evaluation, particularly in early childhood education, has crossed several fields of endeavor. Still, it represents only a small, briefly treated subset of all such potential contributions; the interested reader also may wish to examine Goodwin and Driscoll (1980) and Smith (1981a, b). Nonetheless, the diversity and potency of these approaches suggest that a multidisciplinary approach for processes such as measurement and evaluation would be beneficial. Early childhood education is likely well served by an electric approach in finding measures for children and in evaluating programs for them.
Simulations of dispersed turbulent multiphase flow

Abstract Direct numerical simulations of homogeneous isotropic turbulence are used to investigate the effects of turbulence on the transport of particles in gas flows or bubbles in liquid flows. The inertia associated with the bubbles or the particles leads to locally strong concentrations of these in regions of instantaneously strong vorticity for bubbles or strain-rate for particles. This alters the average settling rates and other processes. If the mass-loading of the dispersed phase is significant a random “turbulent” flow is generated by the particle settling. A simple demonstration of this is given, showing the statistically axisymmetric character of this flow and how it can modify an ambient turbulent flow.
X-ray Diffraction Study of InGaN/GaN Superlattice Implanted with Eu3+ Ions

In this work, europium implanted InxGa1-xN/GaN SL with a fixed well/barrier thickness ratio grown by metal-organic chemical-vapor deposition (MOCVD) on GaN/(0001) sapphire substrate were investigated. The as-grown and Eu3+ ion implanted InxGa1-xN/GaN SLs were annealed at different temperatures ranging from 600°C to 950°C in nitrogen ambient. The quality of the SL interfaces in undoped and implanted structures has been investigated by X-ray diffraction (XRD) at room temperature. The characteristic satellite peaks of SLs were measured for the (0002) reflection up to the second order in the symmetric Bragg geometry. The XRD simulation spectrum of the as-grown SL agrees well with the experimental results. The simulation results show 6 at.% of Indium in the InxGa1-xN well sub-layers, with thicknesses of 2.4 and 3.3 nm for single InxGa1-xN well and GaN barrier, respectively. It was observed that annealing the undoped SL does not significantly affect the interfacial quality of the superstructure, whereas, the Eu3+ ion implanted InxGa1-x/GaN SL undergo partial induced degradation. Annealing the implanted SLs shows a gradual improvement of the multilayer periodicity and a reduction of the induced degradation with increasing the annealing temperature as indicated by the XRD spectra.
Effective Educational Inclusion of Students on the Autism Spectrum

Beginning with early efforts to prepare preschool aged children with autism to join their peers in regular education classes, there has been a continuing interest in including children with autism spectrum disorders (ASDs) in regular education classes. A modest body of literature has explored ways to enhance the social interactions of children with ASDs and to more fully integrate them into academic and co-curricular experiences with their peers. These efforts have shown benefits to the children with ASDs as well as their peers in specifically defined situations. While there remains a serious lack of rigorous research in this area and a clear need for additional study regarding the long term impact of full inclusion on both groups of children, the existing research provides some interim strategies for professionals working with these children.
Magnetic resonance studies on membrane and model membrane systems. II. Phosphorus spectra and relaxation rates in dispersions of lecithin.

We present phosphorus magnetic resonance (PhMR) spectra, relaxation rates, and chemical shifts for unsonicated and sonicated lecithins in aqueous dispersions and for egg lecithin in chloroform and methanol. Aqueous lecithin dispersions are characterized by long values for T1 and considerably shorter values for T2. Both of these values as well as the value of the linewidth change with sonication. Lecithin dispersions in methanol and chloroform have relaxation rates shorter than those seen for sonicated lecithin. We do not, at this time, present a detailed interpretation of these results. On an empirical level, however, since the relaxation rates are sensitive to the type of dispersion and possibly to the solvent, we are optimistic that they will be sensitive to structural changes involving the headgroup region.
Energy content of hydrocarbon gas mixtures typical of natural gas

Abstract The principles of group additivity are applied to the problem of determining the energy content of a mixture of hydrocarbons typically found in natural gas. With proper selection of the groups, the energy content of these mixtures (within 2 ppt) is shown to depend on only one variable. This variable is related to the molar refractivity of the gas mixture and can be determined by measuring the index of refraction.
Device for slicing polyacrylamide gels.

Abstract A device for fractionating polyacrylamide gels has been described. Using the device, accurately sized, reproducible slices can be obtained as small as 1.00 mm with gels containing 2.2 to 5.0% acrylamide. In addition. the necessity for prefreezing has been eliminated, thereby saving time and elaborate control procedures to reduce band distortions. The isotopic c counts obtained with the slicing device were highly reproducible and uniform over a wide range of acrylamide concentrations and in actual use could be verified by absorbance traces of the gels.
The Alcohol Use Disorder and Associated Disabilities Interview Schedule-IV (AUDADIS-IV): reliability of alcohol consumption, tobacco use, family history of depression and psychiatric diagnostic modules in a general population sample.

Background: the purpose of this study was to assess the test–retest reliability of newly introduced or revised modules of the Alcohol Use Disorder and Associated Disabilities Interview Schedule-IV (AUDADIS-IV), including alcohol consumption, tobacco use, family history of depression, and selected DSM-IV axis I and II psychiatric disorders. Methods: kappa and intraclass correlation coefficients were calculated for the AUDADIS-IV modules using a test–retest design among a total of 2657 respondents, in subsets of approximately 400, randomly drawn from the National Epidemiologic Survey on Alcohol and Related Conditions (NESARC). Results: reliabilities for alcohol consumption, tobacco use and family history of major depression measures were good to excellent, while reliabilities for selected DSM-IV axis I and II disorders were fair to good. The reliabilities of dimensional symptom scales of DSM-IV axis I and axis II disorders exceeded those of their dichotomous diagnostic counterparts and were generally in the good to excellent range. Conclusions: the high reliability of alcohol consumption, tobacco use, family history of depression and psychiatric disorder modules found in this study suggests that the AUDADIS-IV can be a useful tool in various research settings, particularly in studies of the general population, the target population for which it was designed.
PDB-based protein loop prediction: parameters for selection and methods for optimization.

An approach to loop prediction that starts with a database search is presented and analyzed. To obtain meaningful statistics, 130 loops from 21 proteins were studied. The correlation between the internal conformation of the loop and the conformation of the neighboring stem residues was examined. Distances between C(alpha) and C(beta) of the immediate neighbor residues at each end select template loops as well as more complex (e.g. three residues on either side) matching criteria. To have a high probability that the best possible loop candidate in the database is included in the set, relatively large cutoffs for matching the interatomic distances of the stem residues have to be used in the template loop selection procedure; for loops of length 5, this results in an average of 1000 loops and for loops of length 9, the number is about 1500. The required number increases only slowly with loop length, in contrast to the exponential time increase involved in direct searches of the conformational space. The best loops among the large number of candidates can be determined by ranking them with the standard CHARMM non-bonded energy function (without electrostatics) applied to the backbone and C(beta) atoms. The same representation (backbone plus C(beta)) can be used to optimize the loop orientations relative to the rest of the protein by constrained energy minimization. Target loops that have many non-bonded contacts with the protein yield better results so that analysis of the non-bonded contacts of the selected template loops is useful in determining the expected accuracy of a prediction. The method for loop selection and optimization predicted eight (out of 18) loops of up to nine residues to an RMSD better than 1.07 A relative to the crystal structure; for 17 of the 18 loops, one of the three lowest energy template loops had an RMSD of less than 1.79 A. The prediction of antibody loops from a database search is more effective than that for non-antibody loops. Provided that they belong to one of the canonical classes, very similar antibody loops are certain to exist in the database. Superposition of the stem residues for antibody loops also results in a better orientation than with arbitrary target loops because the neighboring residues tend to have a more similar beta-strand structure. Two H3 loops (for which no canonical structures have been proposed) were predicted with reasonable accuracy (RMSD of 0.49 A and 1.07 A) even though no corresponding antibody loops were in the database.
Genetic Diversity in Elite Cotton Germplasm Determined by Morphological Characteristics and RAPDs

Limited interspecific introgression has been achieved in the breeding of the two primary cultivated species of cotton (Gossypium hirsutum L. and G. barbadense L.). Genetic diversity of 16 near-homozygous elite cotton genotypes derived from interspecific hybridization was investigated at the DNA level with the random amplified polymorphic DNA (RAPD) procedure and at the phenotypic level with stable and highly heritable morphological characters. Eighty random decamer primers were used to amplify DNA via the polymerase chain reaction (PCR) and 135 RAPDs were generated. Nineteen morphological traits were measured on the genotypes in field experiments in 1992 and 1993. Morphological characters were chosen that easily distinguish typical G. hirsutum (upland cotton) from G. barbadense (Pima cotton). Dendrograms were generated for genetic distance from the RAPDs and average taxonomic distance from the morphological data. Both procedures produced two clusters with one resembling G. hirsutum and one G. barbadense. Classification of all genotypes based on the two methods gave similar results with a correlation of 0.63 between the genetic distance and taxonomic distance. Several genotypes were identified that were genetically and phenotypically distant from typical G. hirsutum and G. barbadense. The level of polymorphism exhibited by these genotypes could be exploited in genetic mapping populations to tag economically important traits, such as fiber quality. These genotypes also could serve as a germplasm source of unique alleles in G. hirsutum that are derived from G. barbadense. This experiment demonstrates for the first time that RAPD analysis can reliably determine genetic relationships within a diverse array of Gossypium germplasm.
Achieving Customer Value from Electronic Channels Through Identity Commitment, Calculative Commitment, and Trust in Technology

How consumers feel about themselves––particularly in relation to technology––may have an important influence on their adoption and use of technology. Although research on electronic channels has shown that Web site and consumer characteristics are important predictors of consumer trust, researchers have not considered the role played by consumers’ commitment to their identity as technology users. This paper explores whether consumer identity commitment and calculative commitment to electronic channels impact consumer use of electronic channels and perceived value from the service firm. More specifically, it examines whether these effects are mediated by trust in technology and trust in the firm. Using survey data from 834 consumers engaged in both offline and online banking, plus transaction frequency data supplied by a host firm, the study finds that identity commitment plays an important role in building consumer trust in technology and that calculative commitment increases transaction frequency directly, unmediated by trust in technology. Theoretical and managerial implications of these findings are explored.
Energy spectrum of disordered system and impurity condition

Abstract The behaviour of an electron in an aperiodic lattice is investigated by means of the matrix theory. This approach gives a quantitative condition for the existence of non-localized states.
Prototypicality of responses of autistic, language disordered, and normal children in a word fluency task

Abstract High-functioning autistic, specifically language-impaired, and normal children were administered word fluency tasks in which they were required to provide the names of animals and the names of vehicles. The exemplars provided by each subject for each category were assigned prototypicality ratings according to the norms of Uyeda and Mandler (1980). The autistic children provided less prototypic exemplars than did the language-impaired children or language-matched normals. The results support the notion that autistic children have a semantic processing impairment and that part of the basis for this impairment may lie at the level of organization within lexical categories.
Drift variances of FSTand GST statistics obtained from a finite number of isolated populations

Approximate formulas for the mean and variance of the FSTor GST statistic in a finite number of isolated populations are developed under the effect of random genetic drift. Computer simulation has shown that the approximate formulas give a fairly accurate result unless the initial frequency of one of the alleles involved is close to 1 and t2N is large, where N is the effective size of a subpopulation and t is the number of generations. It is shown that when the number of subpopulations (s) is small, the mean of FSTor GST depends on the initial gene frequencies as well as on s. When the initial frequencies of all alleles are nearly equal to each other and the number of subpopulations is large, the distribution of FST in the early generations is bell-shaped. In this case Lewontin and Krakauer's k parameter is approximately 2 or less. However, if one of the initial allele frequencies is close to 1, the distribution is skewed and leptokurtic, and the k parameter often becomes larger than 2 in later generations. Thus, even under pure random genetic drift, Lewontin and Krakauer's test of selective neutrality of polymorphic genes in terms of FST is not always valid. It is also shown that Jacquard's approximate formula for k generally gives an overestimate.
Death in asthma

Abstract A case is presented of a man of 32 with a typical history of asthma for two years. No definite allergic etiologic substance was found, but his allergy was thought to be bacterial in origin, and he apparently died of asphyxia during an acute attack. Small holes were found in both lungs with an escape of air into the pleural cavities, but without collapse of the lungs. The histologic picture in the lungs is characteristic of that described in athmatics, the chief findings being in the bronchioles: Plugging of the narrowed lumina of the bronchioles with thick mucous containing many eosinophils and Curschmann's spirals; great infolding of the mucosa of the bronchioles; a thickened hyalinzed basement membrane; hypertrophy of the muscle wall; and infiltration of the mucosa, submucosa and mucous glands with many eosinophils and plasma cells. The tracheal mucosa contains a similar infiltration. There are also marked emphysema and hypertrophy of the right ventricle.
Fiber spectroscopy at Palomar Observatory

A new faint-object spectrograph was designed and built around the capabilities of fiber optics. This instrument, the Norris Spectrograph, is designed exclusively for the Cassegrain focus of the Hale Telescope. There are 176 indpendently positionable fibers, each with an aperture 1.5 arcsec in diameter. These 176 probes cover a field of view of diameter about 20 arcmin. The output ends of the fibers are collimated with a spherical mirror, dispersed using a normal reflection grating, and focused onto a 2048 x 2048 CCD using all-transmissive optics. The peak overall efficiency of the instrument will be in excess of 10 percent.
Bidirectional Associations between Pain and Physical Activity in Adolescents

Objectives The objectives were to: (1) examine temporal relationships between pain and activity in youth, specifically, whether physical activity affects pain intensity and whether intensity of pain affects subsequent physical activity levels on a daily basis, and (2) examine clinical predictors of this relationship. Methods Participants were 119 adolescents (59 with chronic pain and 60 healthy) aged 12 to 18 years, 71% female. Adolescents completed 10 days of actigraphic monitoring of physical activity and daily electronic diary recordings of pain intensity, medication use, sleep quality, and mood. Linear mixed models assessed daily associations among physical activity and pain. Daily mean (average count/min) and peak (highest daily level) activity were used for analyses. Medication use, sleep quality, and mood ratings were included as covariates, and age, sex, and body mass index percentile were adjusted for. Results Higher pain intensity was associated with lower peak physical activity levels on the next day (t641=-2.25, P=0.03) and greater medication use predicted lower mean physical activity levels the same day (t641=-2.10, P=0.04). Higher mean physical activity levels predicted lower pain intensity ratings at the end of the day (t705=-2.92, P=0.004), but only in adolescents with chronic pain. Discussion Youth experiencing high pain intensity limit their physical activity level on a day-to-day basis. Activity was related to subsequent pain intensity, and may represent an important focus in chronic pain treatment. Further study of the effect of medications on subsequent activity is needed.
Energy deposition in SO2 via intense infrared laser multiphoton excitation

Abstract The feasibility of multiphoton excitation (MPE) and dissociation (MPD) of triatomic molecules is the subject of current experimental controversy. The most probable path approximation (MPPA) makes use of artificial intelligence algorithms to select the most important excitation paths within the semiclassical Floquet matrix, allowing efficient and accurate calculation of non-linear MPE quantum dynamics to very high order. An ab initio study of SO 2 using the MPPA indicates that collisionless MPD will not be achieved at laser field strengths under 20 GW/cm 2 . The possibility of MPD at higher laser intensities is currently under investigation.
Control of mitochondrial gene expression in the yeast Saccharomyces cerevisiae.

Abstract Mitochondrial promoters in Saccharomyces cerevisiae contain an identical octanucleotide [sequence: see text] sequence present just upstream of the initiation site (at the left end of the arrow). Studies have shown that the transcription rates of mitochondrial genes vary from 7- to 15-fold. The nucleotide at position +2 regulates the efficiency of mitochondrial promoters but does not affect the specificity of initiation. The data presented herein demonstrate that the variable transcription rates of mitochondrial genes are due to different levels of transcriptional initiation. The rate of first phosphodiester bond formation between a purine and a pyrimidine on a weak promoter is much lower than that of purine-purine on a strong promoter. A dinucleotide corresponding to positions +1 and +2 acts in vitro as a primer, bypassing the first phosphodiester bond formation at the initiation site. When these dinucleotides were used to prime transcription, the activities of the strong and weak promoters were found to be identical. In heparin-challenge experiments, there is no significant effect of dinucleotide on heparin-resistant DNA-RNA polymerase complex formation. These results indicate that the low level of transcription from the weak mitochondrial promoter is due to the slow rate of formation of the first phosphodiester bond.
Confidence interval formulas for split-half reliability coefficients.

Confidence interval formulas for the Spearman-Brown and the two-part coefficient alpha are presented.
Information: Its Measurement and Valuation

The current "information revolution," exemplified by the increased use of computers and robots in our society, gives a clear indication of the important role that information plays in any social organization. In the past few decades, much progress has been made refining the conceptual tools that can be used in the investigation of information-related issues. However, the analysis of the role of information remains a complex endeavor. For example, it may even be difficult to develop a consensus among scientists on the proper definition of information. For the purpose of this paper, the following taxonomy will be adopted. Data are defined to be the result of an inquiry process (e.g., sampling or experimentation) concerning particular events (e.g., today's hog price in Omaha, corn yield response to fertilizer in Iowa). By using codes (e.g., written or spoken language), the data can be transmitted as signals over space or time through particular communication devices (e.g., radio, telephone, newspapers). These signals generate messages that can be interpreted and used in decision making. For the statistician, the decision may be either to accept or reject a particular hypothesis. Alternatively, for the economist, the decision could be to select and implement a particular production, consumption, or investment action. In either case, information will be defined here as the screening, editing, and evaluation of data in the context of a particular decision-making process (Caspari). Any of the functions involving information (data coding, processing, and transmission of signals, decision) could be done by men or by machines. The allocation of the tasks between men and machines depends on their relative abilities.' For example, humans are very poor transmission channels: compared to computers, they read or write at a very slow speed and they forget a lot. However, the human language is a very efficient and economical code, and the computer is certainly much less complex than the human brain. In general, machines (computers, robots) often appear to have an advantage over humans when performing simple and repetitive tasks. This, coupled with the development of better and cheaper computers, seems to be the source of the current "information revolution" which promises to alter significantly business decision making. In this context, it seems important for economists to sharpen the conceptual tools that can be used in the analysis of the role and value of information in management or policy decisions. The objective of this paper is to discuss briefly the measurement and economic valuation of information. Alternative information concepts found in the literature are reviewed. It is argued that the valuation of information is best analyzed in the context of decision making under uncertainty. A simple model is developed to illustrate how better information tends to improve the decision-making process. Implications of the model for the valuation of information are presented.
The Q Memory Resident Histogramming System

The LAMPF Data Acquisition System Q includes a subsystem to allow the user to create, delete, enter data in and retrieve data from histograms stored in memory. The system is implemented on PDP-11 computers under RSX-IlM V4.0 as an I/O driver with user-callable subroutines interfacing to the driver. A system with an identical user interface will soon be available on VAX computers under VMS V3.2.
Prolonged isolated thrombocytopenia after hematopoietic stem cell transplantation : morphologic correlation

Prolonged isolated thrombocytopenia, defined as recovery of other cell counts with continuous dependence on platelet transfusions for greater than 90 days after hematopoietic stem cell transplantation (HSCT), develops in approximately 5% of patients who undergo HSCT. Although the clinical conditions associated with prolonged isolated thrombocytopenia have been studied, a systematic review of bone marrow biopsies has not been performed and the pathophysiologic basis has not been defined. We reviewed all HSCT at one center from 1990 to 1995 (n = 454) and found 12 cases that met criteria for prolonged isolated thrombocytopenia (incidence = 12/454 or 3%). Bone marrow core biopsies from 12 patients with prolonged isolated thrombocytopenia were reviewed to determine cellularity, numbers of megakaryocytes, the presence of atypical forms, and clusters of megakaryocytes. These marrow megakaryocyte counts were compared to age and disease matched controls, and 11 normal donors. Patients (aged 1-56 years, mean 32 years) who underwent HSCT (four sibling HLA-identical, five autologous bone marrow, three autologous peripheral stem cell) with prolonged isolated thrombocytopenia had a statistically significant lower absolute megakaryocyte count in bone marrow biopsies performed before transplantation and more than 30 days after transplantation compared to control patients (aged 4 months to 50 years, mean 31 years) who underwent HSCT (four sibling HLA-identical, four autologous bone marrow, four autologous peripheral stem cell) for similar conditions. No apparent differences were seen in size of megakaryocytes, nuclear-cytoplasmic ratios, or clustering of megakaryocytes. Overall marrow cellularities were similar in the three groups. These findings suggest that decreased differentiation of megakaryocytes from stem cells, rather than ineffective platelet production or peripheral destruction of platelets, causes prolonged isolated thrombocytopenia in HSCT patients. Low megakaryocyte counts prior to HSCT may be a useful prognostic indicator, as this feature was associated with the development of prolonged isolated thrombocytopenia.
Biogeochemical impacts of the northward expansion of kudzu under climate change: the importance of ecological context

Climate change is generally expected to push plant species to higher latitudes and elevations; how the climate-induced migrations of disruptive invasive species may affect higher-latitude ecosystems has not been widely examined. Kudzu (Pueraria montana) has large impacts on nitrogen (N) cycling and trace N gas emissions in the southeastern United States. To understand how its projected northward migration under climate change will impact ecosystems in the northeastern United States, we examine the impacts of kudzu in the Mid-Atlantic region, near kudzu's northern invasion front. We pair plots invaded by kudzu with adjacent uninvaded plots, and examine rates of leaf litter decomposition, soil nitrogen pools and net cycling rates, N trace gas emissions, and microbial dynamics. Kudzu litter has more N and decomposes faster than litter from co-occurring species. Unlike in Georgia, near the center of kudzu's current range in the United States, kudzu invasion in the Mid-Atlantic has very small ecosystem impacts, causing significant increases only in the sizes of soil nitrate pools. These Mid-Atlantic ecosystems may be buffered against invasion impacts, creating a lag between changes in the plant community and biogeochemical changes. A combination of factors, including time since establishment, soil types, growing season length, and temperatures, may limit kudzu's biogeochemical impacts along its invasion front.
The effects of high-energy Gamma radiation on dielectric solids

The kinds and magnitudes of radiations present in the various locations near nuclear reactors are discussed as well as the mechanisms of interaction of radiation with matter, namely, group fragmentation, molecular scission, and polymerization. Techniques and locations for obtaining high dose rates are presented. Results of 60-cycle short-time voltage breakdown tests on polyethylene, cellulose acetate, and polyvinyl chloride films along with Formex?-varnished wire are given as a function of integrated dose up to 108 roentgens. Extensive electrical tests on a mica-glass-silicone-resin insulation simulating that used in the electromagnetic pump for the submarine intermediate reactor are described. Measurements of mechanical property changes of irradiated resins by means of a newly developed penetrometer are presented.
Urban Poverty and Social Welfare Policy in the United States: An Undergraduate Research/Training Programme.

Abstract A new, interdisciplinary, research and training programme focusing on urban poverty and social welfare policy in the USA has been established recently at UCLA. This paper describes the structure and organisation of the programme, assesses student reactions and experiences and discusses the importance of major research universities encouraging faculty to develop training of this type.
Equations to describe brain size across the continuum of human lifespan.

Equations fitting the normative values for gender-specific brain size changes are available. However, these equations do not fit for all age ranges across the human lifespan and particularly have failed to examine the fit across the continuum of prenatal and postnatal human life. We sought to develop a parametric equation that best describes the changes in gender-specific brain size as a function of age across the continuum of prenatal and postnatal human life. Brain weight and brain volume data retrieved from the literature were combined to perform a meta-analysis. Additions to previously published findings included collecting a dataset that spanned the continuum of human lifespan, logarithmic transformation of the data and utilization of the Birch equation. We used Akaike’s Information Criterion (AIC) for quantitative evaluation of the new equations. A total of 2,011 brain weight data points spanning from 10 weeks of fetal gestation to over 90 years of age were retrieved. Using our approach, we developed equations with improved fits and lower or similar AIC values compared to the published equations. The new equations are modifications of the basic Birch model. These equations are the first to describe the gender-specific brain weight changes through the continuum of both prenatal and postnatal human life while achieving a level of accuracy similar to or better than the previous, more age-restricted models. The new equations are improved compared to previously used equations and may be useful to those who study brain development, particularly researchers interested in prenatal and postnatal brain size.
Quantitative studies of the opening of the vagina of immature rats following injection of female blood and urine.

RECENTLY Hartman and Littrell (1945) reported a new test for estrogens in minute amounts of blood. This test was based on the ability of estrogens to open the vagina of 16 to 21 day old rats. Their method was said to be sufficiently sensitive to detect the amount of estrogen in 0.02 cc. of blood from the finger of normally menstruating women. The reported simplicity and sensitivity of this test made it seem advisable to standardize it for use in estrogen assays. However, when studies similar to those of Hartman and Littrell (1945) were conducted in this laboratory, it became evident that the estrogen content of blood and urine was insufficient to be detected by this method. Therefore, an attempt was made to enhance its sensitivity by priming the animal with small doses of estrogens injected subcutaneously.
Polarization compensating protective coatings for TPF-Coronagraph optics to control contrast degrading cross polarization leakage

We describe here the design approaches and performance analysis of the OTA in the wavelength band of interest. Coronagraph performance at 600nm wavelength based on a particular coating and occulting focal plane mask is also presented.
Problems To Avoid and Procedures To Follow in Assessing Handicaps

How vulnerable are principals in their role as assessors of handicap? This article presents information on the scope of assessment, test validity and reliability, and commonly used tests. The writers also discuss specific problems as well as steps principals can take to avoid legal actions.
Urethane anesthesia in adult female rats: preliminary observations

Urethane is widely used as a rodent anesthetic in the laboratory setting, and is characterized as producing long-lasting anesthesia. The purpose of this study was to evaluate the quality of anesthesia provided by a single dose of urethane based on the response to a noxious stimulus. If the quality of anesthesia was insufficient to prevent gross purposeful movement (GPM), isoflurane was also administered until no response to noxious stimulation occurred. Five adult Harlan Sprague Dawley rats (6 months of age, 250–300 g) were given urethane (1.4 g kg−1 IP) and evaluated for 120 minutes post-injection. If the rats became laterally recumbent by 20 minutes post-injection, a large hemostat was positioned around the tail and the response to tail clamping was assessed. If no GPM occurred, an additional 20 minutes was allowed to elapse. If the rats were not laterally recumbent or GPM was present, they were placed in a chamber and isoflurane in oxygen was administered. Inspired isoflurane concentrations (ISO) were measured using a S/5 anesthetic gas analyzer (Datex-Ohmeda Division, Helsinki, Finland) calibrated before each experiment with a standardized calibration gas mixture (DOT-34 NRC 300/375 m1014, Datex-Ohmeda Division, Helsinki, Finland). A period of 20 minutes was allowed for equilibration to inspired ISO. The tail-clamp stimulus was then re-applied and the animal's response recorded. If GPM was absent, ISO was lowered by 10–20% and an additional 20 minute interval elapsed. In contrast, if GPM was present, ISO was increased by 10–20%. This procedure was repeated until the ISO required to prevent GPM was determined in duplicate. The position within the estrus cycle influenced pain thresholds in the rats. As such, a vaginal smear was prepared from each rat and the position in the estrus cycle was determined based on vaginal cytology. Rats were euthanatized at the end of the study period. All values were mean ± SD. Four rats became recumbent after urethane injection (time to recumbency: 45 ± 17 seconds). Of these, two rats (one estrus, one metestrus) did not require isoflurane supplementation for the duration of the study. The three remaining rats (two metestrus, one estrus) required isoflurane supplementation. The mean ISO required to prevent GPM was 0.26 ± 0.16%. Position within the estrus cycle did not appear to affect the animal's response to urethane. These results indicate that urethane anesthesia is not long lasting in all rats and provides variable quality of anesthesia. This is of particular concern in the laboratory setting where muscle relaxants are often administered to rats shortly after urethane injection.
General two-dimensional magnetohydrodynamic equilibria with mass flow

A set of reduced ideal MHD equations is derived to investigate equilibria of plasmas with mass flow in general two-dimensional geometry. These equations provide a means of investigating the effects of flow on self-consistent equilibria in a number of new two-dimensional configurations, such as helically symmetric configurations with helical axis, which are relevant to stellarators, as well as axisymmetric configurations. It is found that, as in the axisymmetric case, general two-dimensional flow equilibria are governed by a second-order quasilinear partial differential equation for a magnetic flux function, which is coupled to a Bernoulli-type equation for the density. The equation for the magnetic flux function becomes hyperbolic at certain critical flow speeds which follow from its characteristic equation. When the equation is hyperbolic, shock phenomena may exist. As a particular example, unidirectional flow along the lines of symmetry is considered. In this case, the equation mentioned above is always elliptic. An exact solution for the case of helically symmetric unidirectional flow is found and studied to determine flow effects on the magnetic topology.
Syntheses, stability, and tumorcidal activity of porphyrin dimers and trimers with ether linkages

Abstract The first syntheses of a series of regiochemically pure porphyrin dimers and trimers with ether linkages which are structurally related to Photofrin-II® are described. Stability of these oligomers was investigated using variable temperature proton NMR spectroscopy, and preliminary biological results reveal that manupulation of peripheral substituents causes a remarkable difference in photosensitizing ability in vivo.