cssi/SciSciGPT-SciSciNet huggingface dataset:
Purification of sea urchin ribosomal RNA genes with a single-strand specific nuclease

Abstract Ribosomal RNA genes (rDNA) from Lytechinus variegatus were isolated by selective heat denaturation of main band DNA followed by single-strand specific nuclease (S 1 ) treatment to remove the single-stranded DNA. After S 1 nuclease treatment the partially purified fraction contained 10% rDNA, representing a 50-fold purification. Preparative CsCl centrifugation of this fraction resulted in highly purified rDNA with an average molecular weight of 1.9 · 10 7 and no single-strand breaks. High molecular weight sea urchin DNA was refractory to selective heat denaturation. DNA with an average molecular weight of ⩾2.9 · 10 7 was only 60–80% denatured after heating 13°C above the T m , whereas, DNA with an average molecular weight of ⩽1.9 · 10 7 was 98% denatured. This phenomenon appears not to be due to time, buffer, or pH, but is dependent on size.
The structure and function of glycoprotein hormone receptors: Ganglioside interactions with human chorionic gonadotropin

Abstract Gangliosides inhibit the binding of 125 I-labeled human chorionic gonadotropin to rat testes membranes. The inhibition is the result of an interaction between the hormone and the ganglioside rather than the membrane and ganglioside, and the interaction with the ganglioside can be detected by fluorescence spectroscopy. In both the binding inhibition and fluorescence studies, human chorionic gonadotropin recognizes an oligosaccharide sequence on the ganglioside molecule distinct from the sequence recognized by thyrotropin.
Classification of child stuttering: Part I transient developmental, neurogenic acquired, and persistent child stuttering

A historical and current review of theories and treatments of child stuttering reveal a dichotomy between psychiatrists who support the view that all stutterers have a psychoneurosis, and the speech pathologist who supports the view that all stutterers are psychologically normal. The chronological development of stuttering and the phenomenology of the disorder are presented and point to stuttering as representing a psychologically heterogeneous population; transient developmental stuttering (developmental deviation versus developmental interference), neurogenic acquired stuttering, and persistent stuttering. The author, a child psychiatrist, psychiatrically studied 30 persistent child stutterers, mostly referred from speech pathology outpatient clinics. Eighty percent were boys, and all had been stuttering for at least nine months and 95 per cent had a prior period of speech therapy that was unsuccessful in ameliorating stuttering. None were mentally retarded, borderline or psychotic. Three classes of persistent child stuttering are distinguished: early onset male stuttering, female stuttering, and late onset male stuttering. Persistent early onset male stuttering is described on the basis of “silently cumulative” parental patterns, child's level of developmental conflict, and psychodynamic etiological factors.
OXIDATION-REDUCTION POTENTIALS AND THE POSSIBLE RESPIRATORY SIGNIFICANCE OF THE PIGMENT OF THE NUDIBRANCH CHROMODORIS ZEBRA

1. Oxidation-reduction potential methods have been applied to a study of the blue-purple pigment present in solution in the blood and in the tissue cells of the nudibranch Chromodoris zebra . 2. The blue-purple pigment and its yellow reduction product form a reversible system whose Eo ' = x0.102 volts at pH 7.0 and whose valence change from oxidant to reductant appears to be one . 3. The system is unlike oxyhemoglobin-hemoglobin in the mode of oxygen transfer. Its role as a possible respiratory material is discussed.
Changes in Instruments and Sites Affecting Historical Weather Records: A Case Study

Abstract All long historical climate records are based on measurements that experienced shifts in instrumentation, site characteristics, or locations. How such changes affect the quality of past data remains an uncertainty for the thousands of historical records, confounding efforts to assess climate change. Fortunately, one station in Illinois with 118 yr of records has also kept detailed records of all such shifts plus overlapping measurements of temperatures and precipitation, allowing exact measurements of how conditions changed over time. This study examined these data and found varying discontinuities of 0.1°–0.9°C in annual temperatures due to various shifts, but no changes in daily precipitation related to site shifts. However, hourly precipitation amounts from recording rain gauges did undergo a considerable shift due to changes in rain gauge types. Similar studies need to be made of other stations with comparable historical records of station and instrument shifts and with overlapping measuremen...
Lapses in sustained attention and their relation to executive control and fluid abilities: An individual differences investigation

A latent variable analysis was conducted to examine the nature of individual differences in lapses of attention and their relation to executive and fluid abilities. Participants performed a sustained attention task along with multiple measures of executive control and fluid abilities. Lapses of attention were indexed based on the slowest reaction times in terms of both quintiles and the τ parameter from the ex-Gaussian distribution. It was found that the slowest, but not the fastest, RTs in the sustained attention task were related to a broad based executive control factor and a fluid intelligence factor. The results further suggested that only the working memory capacity and response inhibition sub-executive control factors were related to the slowest RTs, with the fluency measures not being related to any of the RT variables. The results are consistent with the idea that fluctuations or lapses in sustained attention, as indexed by the slowest responses, are related to executive control and fluid abilities.
Bridging the gap between the undergraduate and graduate experience in computer systems studies

This paper presents the contents of a Special Topics Class used to introduce undergraduate students to the different approach to learning and thinking found in the graduate level Computer Systems environment. During the first half of the semester, the students received instruction in reading and writing technical documents, and had experience with professor-guided self-study. During the second half of the semester, the students presented an idea for a simulator, built it, and used it to conduct simple experiments. After completing the experiments, they were encouraged to brainstorm variations to the algorithms or architectures they simulated, which would improve performance. Student evaluations revealed that for 50% of the students, their interest in graduate school increased as a result of the class.
Kinetics of nitrate reduction by iron at near neutral pH

Although considerable research has been conducted on nitrate reduction by zerovalent iron (ZVI), the process kinetics at near neutral pH has not been studied thoroughly. In this study, a kinetic model with a double-Langmuir-adsorption formulation was developed to represent site saturation effects of aqueous Fe\U2+\N and NO\d3 on nitrate reduction in a ZVI system at near neutral pH. Both an analytical solution and a numerical solution of the proposed model were developed. The kinetic parameters were evaluated based on batch experiments with two types of ZVI. Sensitivity analysis indicates that it is rather difficult and unreliable to estimate the parameters of the proposed multivariable nonlinear kinetic model from a single test curve. A better strategy is to obtain reliable parameters by designing specific experiments to target one parameter each time. The results indicate that, although the values of the kinetic parameters might change with different types of iron powder, the kinetic model can fit the experimental data very well, and therefore is consistent with the proposed mechanism.
Ultrastructure of the copulatory organ of Haplopharynx quadristimulus and its phylogenetic significance (Plathelminthes, Haplopharyngida)

The male reproductive system in Haplopharynx quadristimulus consists of paired testes, sperm ducts, seminal vesicles, seminal ducts, a copulatory organ containing prostatic vesicle and stylet apparatus, and the male canal. By electron microscopy all components appeared to be regional specializations of a canal extending from the testes to the body wall and lined by a multiciliated epithelium. The epithelium of the stylet apparatus contained six different cell types. One cell type (matrix syncytium) formed the stylet and the other five were located distal to the stylet/prostatic-vesicle junction along the male system epithelium. Each cell type was attached to the supporting intercellular matrix at a different level along the stylet apparatus. All cell types extended to the distal end of the stylet apparatus regardless of where they originated along its length. The cells in the apparatus lacked cilia, but one of the cell types contained rootlets. Modified rootlets or rootlet derivatives were possibly present in another cell type in the form of rootlet-like ribbons. The findings support the monophyly of the Macrostomida Haplopharyngida (by common occurrence of a matrix syncytium) and at the same time suggest their separation as two distinct taxa (by differences in the structure of the prostatic vesicle and other parts of the stylet apparatus).
DYNAMIC POWDER CONSOLIDATION AND SYNTHESIS OF INTERMETALLIC COMPOUNDS

Utilisation des reactions induites par une onde de choc pour joindre des poudres metalliques inertes. Etude sur des melanges de poudres Ni et Al, Ti et Al, Nb et Al ajoutes a des poudres de composition intermetallique TiAl
Superhydrophilic textured-surfaces on stainless steel substrates

Aluminum-induced crystallization (AIC) of amorphous silicon (a-Si) is used to produce micro/nano-textured surfaces on stainless steel substrates at low temperatures for altering the wetting property of the substrates. The micro/nano-textured surfaces were characterized using scanning electron microscopy, X-ray spectroscopy, and X-ray diffraction. The wetting properties of the textured surfaces were characterized by water contact angle measurements. It was found that AIC of a-Si changes the apparent contact angles of stainless steel substrates from 90° to about 0°, measured 0.5 s after a water droplet drops on the surfaces. The study also shows that a superhydrophilic textured surface can be converted to a highly hydrophobic surface with an apparent contact angle of 145° by coating the surface with a layer of octadecyltrichlorosilane.
Stereopsis in patients with albinism: clinical correlates.

Abstract Purpose: A hallmark of albinism is excessive decussation of retinostriate projections at the optic chiasm. This misprojection might lead to abnormalities in the retinal correspondence and may account for the usual absence of stereovision. We report on 2 groups of patients with albinism who have either fine or gross stereopsis and compare the clinical findings of these groups to other patients with albinism with similar visual acuities but no stereopsis. Methods: A retrospective chart review of patients with albinism was used to segregate those with a letter visual acuity of 20/100 or better in one eye, assessment of stereopsis, and strabismus • 10 PD. Forty-five patients were identified. Albinism type, best-corrected visual acuity, motility, Titmus vectograph stereoacuity, iris and macula transparency grades, and the presence or absence of both melanin and an annular reflex in the macula were tabulated. A comparison of the clinical characteristics of the groups with and without stereopsis was made. Results: Those albino subjects who demonstrated stereopsis had better visual acuity, less iris transillumination, more frequent presence of melanin in the macula, less nystagmus, and less marked foveal hypoplasia than the albino subjects without stereopsis. No nystagmus was clinically detected in 5 patients with fine stereopsis. All these differences were statistically significant. Macular transparency grade was not significantly different between the groups. Conclusions: Patients with albinism who demonstrate stereopsis tend to have better visual acuity, more iris pigment, and more melanin pigment in the macula than their counterparts without stereopsis. (J AAPOS 2001;5:98-104)
HEREDITARY OSTEOPETROSIS OF THE RABBIT II. X-RAY, HEMATOLOGIC, AND CHEMICAL OBSERVATIONS

The results of x-ray, hematologic, and chemical studies on cases of hereditary osteopetrosis of the rabbit are described and the resemblance of the findings to those of the severe juvenile form of human osteopetrosis is pointed out. The outstanding feature of the x-ray examinations was the homogeneous dense appearance of the entire skeleton. This condition was present at birth. In older cases there was evidence of some differentiation of bone structure. The hematologic studies showed that the disease was characterized by the development of a macrocytic anemia, thrombocytopenia, and a moderate myeloid leucocytosis. Other abnormal findings included high reticulocyte and normoblast counts, anisocytosis and poikllocytosis, and degenerative changes of the neutrophiles and lymphocytes. The chemical studies showed very low serum calcium values; serum phosphorus values were low during the first 4 weeks of life but were somewhat higher than normal levels in older cases. The serum phosphatase values were elevated. The blood sugar content was generally low. The blood cholesterol values were generally high. The liver glycogen values were small especially in older cases and those for muscle glycogen were somewhat smaller than normal values.
Mechanobiological predictions of growth front morphology in developmental hip dysplasia

Developmental dysplasia of the hip (DDH) is the most common orthopedic problem of newborn children. Most clinicians and researchers agree that the primary cause of DDH is abnormal mechanical forces on the head of the femur due to limb position, pressure from the womb, or ligament laxity. The abnormal mechanical forces result in altered growth and bony deformities, in particular large neck-shaft and anteversion angles in the proximal femur and a shallow acetabulum. Previous studies have suggested that intermittent octahedral shear stress promotes growth and ossification, while intermittent hydrostatic compressive stress inhibits growth and ossification. We implemented these mechanobiological principles into a finite element model to predict the rate of progression of the growth front and the formation of coxa valga (large neck-shaft angle) in DDH. Under the assumed normal fetal loading conditions the hydrostatic stress was even across the growth front, but the octahedral shear stress was higher in the center than at the edges. This stress profile promoted growth in the center and a produced a convex growth front shape. Under loading conditions of the dysplastic hip, the octahedral shear stress was much larger on the medial side than on the lateral side, which promoted growth on the medial side and resulted in coxa valga. These results indicate that abnormal forces on the prenatal hip might influence total bone morphology and the development of DDH. These findings might help in understanding the etiology and pathology of other developmental bone deformities.
Cloning and functional expression of a cDNA encoding geranylgeranyl diphosphate synthase from Taxus canadensis and assessment of the role of this prenyltransferase in cells induced for taxol production.

Geranylgeranyl diphosphate synthase supplies the essential acyclic precursor for Taxol biosynthesis in methyl jasmonate-induced Taxus canadensis suspension cell cultures. A cDNA encoding this prenyltransferase was cloned from an induced T. canadensis cell library. The recombinant enzyme expressed in yeast was confirmed by radiochromatographic analysis to produce geranylgeranyl diphosphate from farnesyl diphosphate and [4-14C]isopentenyl diphosphate and was subjected to preliminary kinetic characterization. The deduced amino acid sequence of this gymnosperm geranylgeranyl diphosphate synthase (393 residues) resembles those of geranylgeranyl diphosphate synthases of angiosperm origin, except for the 90-100 N-terminal residues that correspond to the plastidial transit peptide. The full-length preprotein (42.6 kDa) and two truncated versions, corresponding to putative "mature proteins" from which the transit peptide was deleted, were transformed into a yeast mutant defective for the beta-subunit of type II geranylgeranyl transferase. Under conditions of regulated expression, both the full-length construct and the longest of the truncations (at Phe 99) were able to complement the mutant. However, when these two constructs were overexpressed in a wild-type yeast strain, they were apparently toxic, most probably due to depletion of endogenous farnesyl diphosphate as the cosubstrate for the geranylgeranyl diphosphate synthase reaction. In vitro activity of the corresponding recombinant enzymes paralleled the expression level of the constructs as determined by SDS-PAGE analysis of the appropriate proteins of predicted size, and was correlated with toxicity in the wild-type yeast strain and with ability to complement the mutant strain. Results from the analysis of geranylgeranyl diphosphate synthase activity levels and measurement of the corresponding steady-state mRNA levels during the time course of Taxol production in induced T. canadensis suspension cell cultures, and comparison to similar data for activity and message levels for taxadiene synthase, the committed step of the pathway, indicated that for each enzyme both the level of corresponding message and catalytic activity rapidly increased after methyl jasmonate induction.
Individualizing Axillary Management in Breast Cancer Treatment

Management of the axilla in patients with breast cancer has evolved significantly in the last century. The status of the axillary lymph nodes continues to provide important prognostic information. However, in contrast to the beliefs of Halsted, we now understand that surgical clearance of the axilla is not critical to long-term survival. Indeed, tumor biology and occult systemic metastases determine long-term survival after breast cancer treatment. Randomized controlled trials have demonstrated the safety and efficacy of sentinel lymph node biopsy in patients with early breast cancer and without clinical evidence of axillary involvement. Management of the axilla should be tailored to the individual patient’s clinical stage, patient and tumor characteristics, and treatment preferences. Special consideration should be given to the following situations: elderly patients, pregnancy, treatment of DCIS, prior axillary surgery, prophylactic mastectomy, inflammatory breast cancer, and neoadjuvant chemotherapy. Management of the axilla will continue to change as additional evidence from randomized controlled trials becomes available.
Spaced retrieval enhances memory for a name-face-occupation association in older adults with probable Alzheimer's disease

The authors trained 4 older adults with probable Alzheimer's disease to recall a name-face-occupation association using the spaced retrieval technique. Six training sessions were administered over a 2-week period. On each trial, participants selected a target photograph and stated the target name and occupation at increasingly longer retention intervals, contingent upon successful recall. Two transfer tasks were included to determine whether the trained association transferred to the person whose picture served as the training stimulus. Results yielded a positive effect of spaced retrieval on memory for the trained association. Analyses of errors revealed that participants remembered the target person's occupation more often than his or her name. There was modest evidence of transfer of the name-face-occupation association to the actual person. Implications of these data for memory remediation and quality of life in cognitively impaired older adults are considered.
The bacteriophage Mu middle operon: essential and nonessential functions.

Abstract Transcription during the bacteriophage Mu lytic cycle occurs in three phases: early, middle, and late. Previous DNA sequence analysis of the middle operon revealed five potential open reading frames (ORFs) with lengths of 39, 42, 72, 120, and 140 amino acids. The distal 140-amino-acid ORF encodes C, the activator of late transcription. Expression of the middle operon under the control of a T7 promoter and T7 RNA polymerase resulted in production of two polypeptides of 15 (ORF 120) and 16.5 kDa (C). Introduction of a linker containing a translation terminator into ORF 120 resulted in the production of a truncated form of the ORF120 polypeptide. When the ORF 120 linker mutation and several middle operon deletion mutations were assayed for their effect on Mu growth in Escherichia coli K12, the deletions caused 6-to 22-min delays in lysis, and two resulted in a smaller plaque morphology, but all gave normal plating efficiencies and burst sizes. The plating efficiencies for all the mutants were also similar to that of wild-type Mu on alternate hosts E. coli C, Citrobacter freundii, Shigella sonnei , and Shigella flexneri . These results indicate that, with the exception of C , the middle operon ORFs are not essential for phage development.
Rescue of Adult Hippocampal Neurogenesis in a Mouse Model of HIV Neurologic Disease

The prevalence of central nervous system (CNS) neurologic dysfunction associated with human immunodeficiency virus (HIV) infection continues to increase, despite the use of antiretroviral therapy. Previous work has focused on the deleterious effects of HIV on mature neurons and on development of neuroprotective strategies, which have consistently failed to show a meaningful clinical benefit. It is now well established that new neurons are continuously generated in discrete regions in the adult mammalian brain, and accumulating evidence supports important roles for these neurons in specific cognitive functions. In a transgenic mouse model of HIV neurologic disease with glial expression of the HIV envelope protein gp120, we demonstrate a significant reduction in proliferation of hippocampal neural progenitors in the dentate gyrus of adult animals, resulting in a dramatic decrease in the number of newborn neurons in the adult brain. We identify amplifying neural progenitor cells (ANPs) as the first class of progenitors affected by gp120, and we also demonstrate that newly generated neurons exhibit aberrant dendritic development. Furthermore, voluntary exercise and treatment with a selective serotonin reuptake inhibitor increase the ANP population and rescue the observed deficits in gp120 transgenic mice. Thus, during HIV infection, the envelope protein gp120 may potently inhibit adult hippocampal neurogenesis, and neurorestorative approaches may be effective in ameliorating these effects. Our study has significant implications for the development of novel therapeutic approaches for HIV-infected individuals with neurologic dysfunction and may be applicable to other neurodegenerative diseases in which hippocampal neurogenesis is impaired.
Measurements of the growth of electrolytic bubbles

An experimental study of the growth of bubbles during electrolysis was carried out by means of high-speed motion picture photography through a microscope. The bubbles were H2, O2, Cl2, and CO2 on platinum, nickel, copper, and iron electrodes, at pressures from 1 to 2 atm, with controlled constant current densities from 0·01 to 0·12 A/cm2. The asymptotic growth rates of the bubbles were found to agree with the theoretical predictions of either Scriven or Buehl and Westwater. Of 600 bubbles observed, none grew with a constant contact angle. A conclusion of significance to theoretical workers is that contact angle definitely is a very weak variable, at least in the range of 0 to about 100 degrees.
Super‐optimal temperatures are detrimental to peanut (Arachis hypogaea L.) reproductive processes and yield at both ambient and elevated carbon dioxide

Continuing increases in atmospheric carbon dioxide concentration (CO2) will likely be accompanied by global warming. Our research objectives were (a) to determine the effects of season-long exposure to daytime maximum/nighttime minimum temperatures of 32/22, 36/26, 40/30 and 44/341C at ambient (350lmolmol � 1 ) and elevated (700lmolmol � 1 )C O2 on reproductive processes and yield of peanut, and (b) to evaluate whether the higher photosynthetic rates and vegetative growth at elevated CO2 will negate the detrimental effects of high temperature on reproductive processes and yield. Doubling of CO2 increased leaf photosynthesis and seed yield by 27% and 30%, respectively, averaged across all temperatures. There were no effects of elevated CO2 on pollen viability, seed-set, seed number per pod, seed size, harvest index or shelling percentage. At ambient CO2, seed yield decreased progressively by 14%, 59% and 90% as temperature increased from 32/22 to 36/26, 40/30 and 44/341C, respectively. Similar percentage decreases in seed yield occurred at temperatures above 32/221C at elevated CO2 despite greater photosynthesis and vegetative growth. Decreased seed yields at high temperature were a result of lower seed-set due to poor pollen viability, and smaller seed size due to decreased seed growth rates and decreased shelling percentages. Seed harvest index decreased from 0.41 to 0.05 as temperature increased from 32/22 to 44/341C under both ambient and elevated CO2. We conclude that there are no beneficial interactions between elevated CO2 and temperature, and that seed yield of peanut will decrease under future warmer climates, particularly in regions where present temperatures are near or above optimum.
Space-varying restoration of optical images

The improvement in optical image quality is now generally attempted in two stages. The first stage involves techniques in adaptive optics and occurs as the observed image is initially formed. The second stage of enhancing the quality of optical images generally occurs off line and consists of the postprocessing step of image restoration. Image restoration is an ill-posed inverse problem that involves the removal or the minimization of degradations caused by noise and blur in an image, resulting from, in this case, imaging through a medium. Our work concerns a new space-varying regularization approach and associated techniques for accelerating the convergence of iterative image postprocessing computations. Denoising methods, including total variation minimization, followed by segmentation-based preconditioning methods for minimum residual conjugate gradient iterations, are investigated. Regularization is accomplished by segmenting the image into (smooth) segments and varying the preconditioners across the segments. The method appears to work especially well on images that are piecewise smooth. Our algorithm has computational complexity of only O(ln2 log n), where n2 is the number of pixels in the image and l is the number of segments used. Also, parallelization is straightforward. Numerical tests are reported on both simulated and actual atmospheric imaging problems. Comparisons are made with the case where segmentation is not used. It is found that our approach is especially attractive for restoring images with low signal-to-noise ratios, and that magnification of noise is effectively suppressed in the iterations, leading to a numerically efficient and robust regularized iterative restoration algorithm.
Cross sections and polarizations for protons scattered from 48Ca between 6.0 and 12.7 MeV

Abstract The energy dependence of cross sections and polarizations for protons scattered from 48Ca has been measured in 50 keV steps from 6.0 to 12.7 MeV. Significant fluctuations are observed, especially in the polarization, over the entire energy range investigated. Angular distributions were measured at 8.0, 10.0 and 12.0 MeV. Results of an optical-model analysis are given.
Perampanel: A Selective AMPA Antagonist for Treating Seizures

Perampanel is a selective, noncompetitive AMPA receptor antagonist that has recently been approved for treating localization-related epilepsy. This article reviews the pharmacology, clinical development, efficacy, and safety/tolerability of perampanel.
Structural and Mutational Analysis of Escherichia coli AlkB Provides Insight into Substrate Specificity and DNA Damage Searching

In Escherichia coli, cytotoxic DNA methyl lesions on the N1 position of purines and N3 position of pyrimidines are primarily repaired by the 2-oxoglutarate (2-OG) iron(II) dependent dioxygenase, AlkB. AlkB repairs 1-methyladenine (1-meA) and 3-methylcytosine (3-meC) lesions, but it also repairs 1-methylguanine (1-meG) and 3-methylthymine (3-meT) at a much less efficient rate. How the AlkB enzyme is able to locate and identify methylated bases in ssDNA has remained an open question. We determined the crystal structures of the E. coli AlkB protein holoenzyme and the AlkB-ssDNA complex containing a 1-meG lesion. We coupled this to site-directed mutagenesis of amino acids in and around the active site, and tested the effects of these mutations on the ability of the protein to bind both damaged and undamaged DNA, as well as catalyze repair of a methylated substrate. A comparison of our substrate-bound AlkB-ssDNA complex with our unliganded holoenzyme reveals conformational changes of residues within the active site that are important for binding damaged bases. Site-directed mutagenesis of these residues reveals novel insight into their roles in DNA damage recognition and repair. Our data support a model that the AlkB protein utilizes at least two distinct conformations in searching and binding methylated basesmore » within DNA: a 'searching' mode and 'repair' mode. Moreover, we are able to functionally separate these modes through mutagenesis of residues that affect one or the other binding state. Finally, our mutagenesis experiments show that amino acid D135 of AlkB participates in both substrate specificity and catalysis.« less
Continuing the dialogue: a response to Draper's critique of Fawcett's ‘Conceptual models and nursing practice: the reciprocal relationship’;

In their response to Draper's (1993) critique of Fawcett's (1992) paper 'Conceptual models and nursing practice: the reciprocal relationship', the authors argue that Draper's critique is flawed. They point out that Draper fails to acknowledge the diversity within the positivist movement, makes logical leaps, and fails to acknowledge Fawcett's long-standing distinction between middle-range theories and conceptual models and her discussions of the differences in the criteria to be used when evaluating conceptual models and theories.
Low-Vision Aids for Partially Sighted Persons

An obstacle to the more widespread use of optical aids for partially sighted persons is the great variety of such devices needed to provide for the specific needs of each pa­ tient." Spectacle-borne aids present an ad­ ditional problem—if these are prescribed but later found not to be optimal, replacement with a new aid is a considerable expense for the patient. More visually handicapped pa­ tients would be helped if a simple, flexible method could be found to streamline dis­ pensing by standardizing sizes of spectacle aids so that they could be used interchange­ ably in spectacles of varying sizes and shapes. A recent innovation at the Low Vi­ sion Ginic of the Cleveland Society for the Blind meets some of these requirements.
Policy‐Elite Perceptions and Social Movement Success: Understanding Variations in Group Inclusion in Affirmative Action1

Using historical analysis of the inclusiveness of Labor Department affirmative action regulations for African‐Americans, American Indians, Asian Americans, Latinos, women, and white ethnics, this article shows that understanding variations in social movement success requires understanding policy‐elite perceptions of the meanings of social movements and the groups they represent. Variation in perceived meanings along dimensions of definition, morality, or threat helps explain the speed of group inclusion, the amount of mobilization needed, and possiblity for failure. Ethnoracial minorities benefited from perceptions of definitional and moral similarity to blacks, but elites perceived women as different definitionally and white ethnics as different definitionally and morally. Policy‐elite perceptions create obstacles for some groups, forcing them to struggle longer and harder for the same policy outcome.
The effect of birth interval on perinatal survival and birth weight

It has long been recognized, at least in developing countries, that short birth intervals have a negative effect on the well-being of the mother and of the infant displaced by the new pregnancy. In some cultures this knowledge is internalized to the extent that it is incorporated into the language; ‘kwashiokor’, in one of the languages of Ghana, means a disease occurring in a young child displaced from his mother’s breast by a new baby15. In many areas of Africa, the baby who displaced his older sibling is called a thief14. Because of this, many cultures have established practices that serve to delay a new pregnancy at least until the baby is weaned; prolonged breast-feeding is accompanied by sexual abstinence in many societies10. Sometimes abstinence is maintained until the resumption of menstruation or longer2.
Evaluating the impact of simultaneous multithreading on network servers using real hardware

This paper examines the performance of simultaneous multithreading (SMT) for network servers using actual hardware, multiple network server applications, and several workloads. Using three versions of the Intel Xeon processor with Hyper-Threading, we perform macroscopic analysis as well as microarchitectural measurements to understand the origins of the performance bottlenecks for SMT processors in these environments. The results of our evaluation suggest that the current SMT support in the Xeon is application and workload sensitive, and may not yield significant benefits for network servers.In general, we find that enabling SMT on real hardware usually produces only slight performance gains, and can sometimes lead to performance loss. In the uniprocessor case, previous studies appear to have neglected the OS overhead in switching from a uniprocessor kernel to an SMT-enabled kernel. The performance loss associated with such support is comparable to the gains provided by SMT. In the 2-way multiprocessor case, the higher number of memory references from SMT often causes the memory system to become the bottleneck, offsetting any processor utilization gains. This effect is compounded by the growing gap between processor speeds and memory latency. In trying to understand the large gains shown by simulation studies, we find that while the general trends for microarchitectural behavior agree with real hardware, differences in sizing assumptions and performance models yield much more optimistic benefits for SMT than we observe.
Accounting for special purpose entities: The control view versus the primary beneficiary view for consolidation

This article provides an analysis of the economic incentives and financial reporting for Special Purpose Entities (SPEs) over the last four decades. The analysis explains economic factors motivating business use of SPEs and the origins of SPEs in lease accounting and securitization transactions. Related financial reporting standards are identified and discussed, including the historical shift from a traditional control viewpoint to a primary beneficiary viewpoint for financial reporting for consolidation for SPEs (recently renamed Variable Interest Entities (VIEs) in U.S. Financial Accounting Interpretation 46R). The article also includes illustrative journal entries explaining SPE transactions from both the viewpoint of the creating company(s) and the SPE. Actual financial reporting examples and/or journal entries for SPEs created by Bank of America, General Motors Acceptance Corporation, Lucent Technologies and Alza Pharmaceuticals Corporation are also provided.
A Simple Medium for Selective Isolation and Enumeration of Soil Actinomycetes

Most media developed for enumerating soil actinomycetes do not prevent the growth of bacteria. When the pH of water agar was adjusted to 10.5, more than 90% of bacterial colonies from natural soil were suppressed, whereas the number of actinomycete colonies remained constant. All six species of bacteria tested were completely or nearly completely inhibited in alkaline water agar, whereas, colony development of all six actinomycetes was not affected. When water agar was used the numbers of actinomycetes from soil amended with glucose or alfalfa meal were very difficult to count because of the presence of numerous bacteria. In alkaline water agar more than 99.9% of bacteria were suppressed, and the numbers of actinomycetes were easily determined.
The new institutional economics and a model of contract

Abstract This paper presents a model of contract that incorporates many of the features identified in the New Institutional Economies. Concepts such as ‘transaction costs’, ‘bounded rationality’, ‘opportunism’, and ‘asset specificity’ have natural interpretations in the framework of the model. The model makes explicit provision for damage measures for breach of contract, permitting a reexamination of some New Institutional ideas when court ordering is possible. It is demonstrated that an explicit provision for the legal background has a profound effect on New Institutional reasoning, and should be taken into consideration in developing policy towards non-standard contracting.
Righting the resource management ship: a response to Grose.

Absolute certainty is a luxurious state that is seldom attained by competent decision makers. Natural resource managers are accountable to the public for high-stakes actions that have incompletely understood consequences, so there is little tolerance for error. I argue that the traditional tools of science and decision theory are both necessary and sufficient, despite recent ‘backwards thinking' on this topic.
Effect of silicon supply on growth, fertility, and mineral composition of an annual brome, Bromus secalinus L. (Gramineae).

A study of the effects of three levels of silicon nutrition, representing low, intermediate, and high levels, shows that silicon does not enhance the vegetative growth of Bromus secalinus (cheat), yet it increases the rate of seed development and the efficiency of seed set. Grasses supplied with silicon have a higher percent of viable seeds compared to those grown in very low levels of silicon. Silicon supply, however, is not an absolute requirement for cheat reproduction, since grasses growing in low silicon levels set flowers and seeds, and the average weight of individual seeds or the mean number of inflorescences per plant are not influenced by silicon nutrition. Concentrations of silicon in tissues of cheat increase over time and with higher levels of silicon supply. Considerable differences are found in the silicon content of various vegetative and reproductive parts of cheat. Among vegetative parts, levels of silicon are lowest in stems and highest in green and senescent leaf blades. Among reproductive parts, silicon is most highly concentrated in the husks (glumes, lemmas, and paleas) surrounding filled seeds and is almost nonexistent in the seed itself. Mechanisms influencing silicon deposition and the ecological significance of the present findings are discussed. Nutritional studies of silicon in plants have shown that the application of silicon may be indispensable for the growth of some grasses that concentrate it in large amounts (Takahashi and Miyake, 1977), while other grasses show normal growth when silicon is not included in the nutrient solution (Lewin and Reimann, 1969; Jarvis, 1987). The increased vegetative and reproductive growth of several grasses in the presence of silicon has led to suggestions that it may be essential for plant growth and development
Writing Discernment in Theological Education

How can we best address writing improvement for seminary students? This article describes the implementation of a Writing Assistance Program that teaches remedial skills in grammar structure and paper organization as well as mentors all students to develop their fullest writing potential. Four models of writing instruction are discussed and examples are given of the best use of each. The article concludes with lessons learned from the experience and tips for other seminaries.
Effects of Gluten Free / Casein Free Diet in Young Children with Autism: A Pilot Study

With reports of the growing incidence of autism spectrum disorder ASD in the United States, a large number of families of affected children is seeking alternative or complementary forms of treatment. One of the more popular interventions has been use of elimination regimes, such as the gluten and casein free (GFCF) diet. This pilot study involved a three-month, prospective, open label, randomized, parallel groups design of a GFCF diet compared to a healthy, low sugar diet (attention control) for young children with ASD. Both treatment groups evidenced some gains across a range of variables, including measures of behavior, language, and ratings of the core features of ASD. No statistically significant differences were noted between treatment groups. While our results do not support use of a GFCF diet in ASD, it is possible that a greater period of time is required for treatment before gains can be observed. Moreover, no significant nutritional differences or side effects were observed on the GFCF diet compared to the control diet. However, adherence to the GFCF diet proved difficult based on our adherence data.
Calculation of mean excitation energy for all elements

Abstract The mean excitation energy I in the stopping power is calculated using Lindhard and Scharff's theory with a Hartree-Fock-Slater charge distribution. The calculation I Z versus atomic number Z reveals structure as observed in many experiments.
Un/Fixing the Fiend: Queering Pedagogy and Dangerous Desires

The notion of desire in theorizing pedagogical relations has a long tradition within foundations of education. Contemporary scholarship on desire in educational theory is informed by sexuality studies and queer theory. This article both builds and expands contemporary dialogue on desire as informed by some of the debates within sexuality studies, and feminist and queer theory. In this article, I investigate elements of desire that are considered dangerous in pedagogical contexts such as “excess” and “devotion.” I then provide an interpretation of the productive nature of conflict and desire in pedagogical encounters. Finally, I explore the pleasure and pain of desires, tension, and conflict as necessarily dangerous and dangerously necessary elements of learning and pedagogical encounters.
A designed chimeric cyanovirin-N homolog lectin: Structure and molecular basis of sucrose binding.

The NMR and X-ray structures of a designed chimeric Cyanovirin-N homolog (CVNH) protein were determined. The individual halves of the structure are similar to their counterparts in the parent proteins, with domains A and B resembling the structures of TbCVNH and NcCVNH, respectively. No significant differences between the solution and crystal conformations were observed, although details in loop conformations and distinct crystal packing-induced features are present. Carbohydrate binding studies by NMR revealed affinity and specificity for Glcα(1-2)Frc and Manα(1-2)Man and the parental half that is devoid of any sucrose affinity in NcCVNH was transformed into a genuine sucrose binding site in the context of the chimera. The atomic details of sugar recognition are seen in the crystal structure of the protein with two bound Glcα(1-2)Frc molecules. Both sugars exhibit different conformations around the glycosidic bond and engage in unique hydrogen bonding networks in the two sites. Although the protein is able to bind two Manα(1-2)Man molecules, a property associated with HIV-inactivation, no anti-HIV activity was observed for the hybrid protein. The present results provide the structural basis for sugar recognition in the CVNH family and aid in deciphering the relationship between sugar binding and anti-HIV activity.
Multi-rate sampling digital audio equalizer

The advantages of implementing a digital audio equalizer using multirate sampling techniques vs. fixed sampling are presented. A theoretical discussion of multirate sampling equalization design issues such as processor computational bandwidth, number of equalizer bands, frequency resolution in a particular band, and filter type and order are reviewed and weighted accordingly. In addition to those multirate sampling equalizer design concepts, an actual implementation is described. A seven slider high-resolution digital audio equalizer has been developed using the Motorola DSP56001 on the NeXT Machine. >
The impact of IL28B genotype on the gene expression profile of patients with chronic hepatitis C treated with pegylated interferon alpha and ribavirin

Background: Recent studies of CH-C patients have demonstrated a strong association between IL28B CC genotype and sustained virologic response (SVR) after PEG-IFN/RBV treatment. We aimed to assess whether IL28B alleles rs12979860 genotype influences gene expression in response to PEG-IFN/RBV in CH-C patients. Methods: Clinical data and gene expression data were available for 56 patients treated with PEG-IFN/RBV. Whole blood was used to determine IL28B genotypes. Differential expression of 153 human genes was assessed for each treatment time point (Days: 0, 1, 7, 28, 56) and was correlated with IL28B genotype (IL28B C/C or non-C/C) over the course of the PEG-IFN/RBV treatment. Genes with statistically significant changes in their expression at each time point were used as an input for pathway analysis using KEGG Pathway Painter (KPP). Pathways were ranked based on number of gene involved separately per each study cohort. Results: The most striking difference between the response patterns of patients with IL28B C/C and T* genotypes during treatment, across all pathways, is a sustained pattern of treatment-induced gene expression in patients carrying IL28B C/C. In the case of IL28B T* genotype, pre-activation of genes, the lack of sustained pattern of gene expression or a combination of both were observed. This observation could potentially provide an explanation for the lower rate of SVR observed in these patients. Additionally, when the lists of IL28B genotype-specific genes which were differentially expressed in patients without SVR were compared at their baseline, IRF2 and SOCS1 genes were down-regulated regardless of patients’ IL28B genotype. Furthermore, our data suggest that CH-C patients who do not have the SOCS1 gene silenced have a better chance of achieving SVR. Our observations suggest that the action of SOCS1 is independent of IL28B genotype. Conclusions: IL28B CC genotype patients with CH-C show a sustained treatment-induced gene expression profile which is not seen in non-CC genotype patients. Silencing of SOCS1 is a negative and independent predictor of SVR. These data may provide some mechanistic explanation for higher rate of SVR in IL28B CC patients who are treated with PEG-IFN/RBV.
Pressure-Enhanced Molecular Clustering in Liquid Dimethyl Sulfoxide Studied by Raman Spectroscopy

Raman spectroscopy was used to study intermolecular interactions in liquid dimethyl sulfoxide. The non-coincidence of the vibrational wavenumbers of the in-phase and the out-of-phase SO stretching mode was analyzed in the temperature range of 30 – 70 °C under pressures up to 2200 bar. The observed non-linear increase of this splitting parameter as a function of density can be explained by an increase in local order leading to an enhanced coupling of neighboring oscillators. The isotropic SO stretching vibrational band consists of three components which are attributed to clusters differing in intermolecular association strength. The pressure dependence of the integrated intensities of the three SO band components is interpreted as a pressure-induced formation of clusters consisting of strongly associated molecules.