cssi/SciSciGPT-SciSciNet huggingface dataset:
Star-Sensor-Based Satellite Attitude/Attitude Rate Estimator

Recent advancements in star sensor technology suggest that implementations of spacecraft on-orbit attitude determination and control systems based solely On star sensor measurements may soon become practical. This paper defines the requirements such applications impose on the star sensors and the algorithms used to estimate attitude and attitude rate. A practical filter implementation is described. Its open-loop performance is evaluated, and simulation results are presented which suggest that performance consistent with a broad class of spacecraft applications is indeed achievable.
Sequence “signals”: Artifact or reality?☆

Abstract I first review the concept of molecular sequence signal and the various forms it can take in the literature. I then comment on the limitation of this concept on the grounds that sequence signals are neither independent of a subjective representation, nor complete and/or verifiable correlates of the associated biological phenomena.
Binding of Thyroxine Analogs to Human Liver Aldehyde Dehydrogenases

A fragment of a cytosolic thyroid-hormone-binding protein from Xenopus liver was reported to be 92–100% identical to residues 236–258 in several cytosolic aldehyde dehydrogenases [Yamauchi, K. & Tata, J. R. (1994)Eur. J. Biochem. 225, 1105–1112], which have been proposed to form part of the hinge region necessary to bind the adenosine moiety of NAD. Here we investigated the effects of two thyroxine analogs, 3,3′,5–triiodo-l-thyronine and 3,3′,5-triiodothyroacetic acid, on purified human liver mitochondrial and cytosolic aldehyde dehydrogenases. The compounds were found to be competitive inhibitors against NAD and uncompetitive inhibitors with respect to aldehyde. At pH 7.4, the apparent Ki values were in the micromolar range when the concentration of NAD was varied. The inhibition against recombinantly expressed mutant forms of aldehyde dehydrogenase, which possessed diminished NAD binding, was determined. Essentially no differences were found between the native enzyme and the mutants, showing that the analog binding was not affected by altering the NAD-binding site. Furthermore, the analogs could displace NAD but not NADH from the enzyme. These findings indicated that the binding of NAD differed from that of NADH, and that aldehyde dehydrogenases, like other dehydrogenases, can be inhibited by thyroxine analogs.
Amplification of magnetic fields by supernova-driven turbulence

Observations of μG magnetic fields in radio galaxies at cosmological epochs as early as around z = 2 have shortened the available time for dynamo action. This fact suggests that the mean-field dynamo mechanism in a global galactic scale either is too slow to amplify a seed field generated by the Biermann battery effect to the level of the observed field strength at z ∼ 2 or needs much stronger seed fields of an order of 10–10 G. A “contamination” picture that amplified magnetic fields in smaller objects, such as stars or AGNs, within a relatively shorter timescale spread out through supernova ejecta, stellar winds, and AGN jets to nearby environments is gaining momentum. In line with this picture, we demonstrate, through three-dimensional numerical experiments, that magnetic fields can be amplified by supernova-driven turbulence with two orders of magnitude smaller e-folding timescale than that of the mean-field dynamo mechanism. Therefore, supernova-driven turbulence may play an important role in amplifying small-scale B -fields in any astrophysical systems that have harbored massive stars. (© 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Ankle ROM and stiffness measured at rest and during gait in individuals with and without diabetic sensory neuropathy

Introduction The purpose of our study was to examine the relationship between ankle dorsiflexion (DF) range of motion (ROM) and stiffness measured at rest (passively) and plantar loading during gait in individuals with and without diabetes mellitus (DM) and sensory neuropathy. Specifically, we sought to address three questions for this at-risk patient population: (1) Does peak passive DF ROM predict ankle DF ROM used during gait? (2) Does passive ankle stiffness predict ankle stiffness used during gait? (3) Are any of the passive or gait-related ankle measures associated with plantar loading?
Exploring a Mathematical Model for the Kinetics of β-Amyloid Molecular Imaging Probes through a Critical Analysis of Plaque Pathology

Amyloid plaques are highly heterogeneous in content, size, density, and macromolecular crowding, as they are composed of masses of fibrils and other cellular material. Given this target architecture, the aggregated microenvironment offers a unique imaging target for ligands and positron emission tomography (PET) molecular imaging probes (MIPs). In this work, we address how the heterogeneous microenvironment of a plaque and its evolution may affect the kinetic rate constant of PET MIPs. We argue that macromolecular crowding will result in anomalous diffusion within plaque regions. To account for anomalous diffusion within plaques, we propose a diffusion-limited ligand-receptor compartmental model. Given the current state of knowledge about the pathological progression of Alzheimer's disease (AD), the model's parameters may be a function of the pathological progression of AD, which could result in biased estimates of the true amyloid load. The bias may be partially overcome through evaluation in conjunction with other measures of AD progression including cerebral glucose metabolism rate, neuronal cell loss, and activated inflammatory presence.
A review of 25 long-term adolescent tobacco and other drug use prevention program evaluations

Abstract Background Although the initial effectiveness of psychosocial strategies programming in preventing smoking and other drug abuse among adolescents has been well established through literature reviews and meta-analyses, much less evidence exists for the long-term follow-up success of these interventions. The primary goal of this paper, therefore, is to summarize the effectiveness of published program evaluation studies that have followed adolescents across the transitional period between junior high and high school for a period of at least 2 years. Methods Studies for inclusion in this review were accessed primarily through a computerized search of Medline, Healthstar, and PsychINFO databases. Intervention studies that met five core criteria were retained for review. Two authors independently abstracted data on study characteristics, methodology, and program outcomes. Results Search results yielded 25 studies suitable for examination. The majority of these studies reported significant program effects for long-term smoking, alcohol, and marijuana outcomes, while indicating a fairly consistent magnitude of program effects. Conclusions This review provides long-term empirical evidence of the effectiveness of social influences programs in preventing or reducing substance use for up to 15 years after completion of programming. However, this conclusion is still somewhat tenuous given the lack of significant program effects reported in several studies and the great variability that existed in the level of internal and external validity across all studies.
Pulsed Infra-Red Microscopy for Debugging Latch-Up on CMOS Products

A Near Infra Red Microscope has been used to debug latch-up problems on CMOS products. The microscope is used to image the recombination radiaton emitted by the forward biased junctions in SCR latch-up. If latchup occurrs at one location it will spread like a cancer untill several sites have latched up. This causes the traditional heat sensing techniques to give incorrect results. Techniques were developed to view and understand the mechanisms which cause latch-up spreading. Various kinds of I/O latch-up modes have been studied and described.
On the evolution of packets of water waves

We consider the evolution of packets of water waves that travel predominantly in one direction, but in which the wave amplitudes are modulated slowly in both horizontal directions. Two separate models are discussed, depending on whether or not the waves are long in comparison with the fluid depth. These models are two-dimensional generalizations of the Korteweg-de Vries equation (for long waves) and the cubic nonlinear Schrodinger equation (for short waves). In either case, we find that the two-dimensional evolution of the wave packets depends fundamentally on the dimensionless surface tension and fluid depth. In particular, for the long waves, one-dimensional (KdV) solitons become unstable with respect to even longer transverse perturbations when the surface-tension parameter becomes large enough, i.e. in very thin sheets of water. Two-dimensional long waves (‘lumps’) that decay algebraically in all horizontal directions and interact like solitons exist only when the one-dimensional solitons are found to be unstable.The most dramatic consequence of surface tension and depth, however, occurs for capillary-type waves in sufficiently deep water. Here a packet of waves that are everywhere small (but not infinitesimal) and modulated in both horizontal dimensions can ‘focus’ in a finite time, producing a region in which the wave amplitudes are finite. This nonlinear instability should be stronger and more apparent than the linear instabilities examined to date; it should be readily observable.Another feature of the evolution of short wave packets in two dimensions is that all one-dimensional solitons are unstable with respect to long transverse perturbations. Finally, we identify some exact similarity solutions to the evolution equations.
Experimental reversal of the normal dorsal-ventral timing of blastopore formation does not reverse axis polarity in Xenopus laevis embryos.

During gastrulation in Xenopus laevis, the dorsal lip of the blastopore normally appears before the ventral lip. Metabolic gradient models propose that the dorsal lip develops from the region of highest metabolic activity and somehow dominates other regions to prevent them from becoming dorsal. To test these ideas, I applied a temperature gradient of 12°C across the embryo. Localized heating of the prospective ventral vegetal region from early in the first cleavage period until gastrulation causes the blastopore lip to form first by 2 hr at the prospective ventral meridian rather than at the prospective dorsal meridian. Despite this reversal of the timing of blastopore formation, gastrulation is completed, and the neural plate forms at its usual position on the prospective dorsal meridian. This demonstrates that the earliest gastrulating regions of the blastopore do not necessarily become dorsal, nor do they inhibit dorsal development by other regions. It is unlikely that axis polarity is based on regional differences in energy metabolism.
Modeling photoluminescence spatial mapping of an isolated defect under uniform and selective excitation

In this work, two different excitation/detection modes, U/L mode and L/L mode for probing an extended defect are compared and discussed. A contrast function is introduced to describe the influence of the defect. We have found that the contrast function not only depends on dimensionality of the system (1-D vs. 2-D), but also depends on the excitation/detection mode. Photoluminescence mapping data using the two modes to study an isolated defect in GaAs are analyzed using our models. The results suggest that the L/L mode can, in principle, offer significantly better spatial resolution than the U/L mode.
Relation between the Weil-Petersson and Zamolodchikov metrics

Abstract We derive the Weil-Petersson metric on the moduli space of Calabi-Yau manifolds from that of Zamolodchikov, as the limit where the coupling tensors of the corresponding non-linear σ-model depend only on constant modes of the string coordinates.
Observations on Gas Bubble Disease among Wild Adult Columbia River Fishes

Abstract A high incidence of gas bubble disease was found among sahnonids and shad sampled from the air-supersaturated Columbia River. Post-capture eye damage to sockeye salmon also may be related to supersaturation of the river.
Maximum solar flux concentration achievable with axicon collectors

Abstract The concentration characteristics of co-axial cone axicon concentrators using the sun as the radiation source are examined. By employing a ray tracing approach and the known concentration result for rays entering strictly parallel to the axicon axis, it is shown that the concentration remains finite and that the maximum achievable value is C0 = 273 at the optimum reflector cone angle of 90°. All radiation entering the solar tracking collector will strike the central absorber cone as long as the vertex angle of this cone exceeds the angular size of the sun.
Aluminum triggers NFκB signalling, inflammatory and apoptotic gene expression in human neural cells

Aluminum, the most abundant neurotoxic metal in the biosphere, has been implicated in the etiology of neurodegenerative disorders including Alzheimers disease (AD). To further understand aluminum's influence on brain gene expression we examined 2360 RNA message levels in normal human neural progenitor (NHNP) cells using DNA microarrays. Of the 53 gene expression levels that were altered by a factor of >3-fold (p < 0.05) over control, 44 were down-regulated. This group included transcripts encoding 17 transcription factors (TFs) or TF kinases, 12 membrane receptors, genes encoding 10 growth factors, neurotransmitters, DNA ligase, DNA repair enzymes and antiapoptotic factors such as bcl-2. The only TFs found to be consistently induced by aluminum on these panels were members of the pro-inflammatory (PI) NFκB gene family. As verified independently by RT–PCR, eight of the nine genes found to be induced by aluminum encoded PI or proapoptotic signalling elements, including NFκB p52/p65, IL-1 precursor, COX-2 and DAXX, a FAS binding protein known to induce apoptosis and repress transcription. These PI gene promoters contain multiple NFκB binding sites; electrophoretic mobility shift assay and [kB]4 vector transfection analysis indicated that aluminum strongly induced NFκB-DNA binding, suggesting a role for aluminum and NFκB in driving PI gene expression in neural cells. Interestingly, many aluminum-induced PI genes are also elevated in AD. These data show that aluminum triggered NHNP cells emulate many of the gene expression patterns observed in AD including the rampant up-regulation of NFκB-sensitive and PI signalling genes. Acknowledgements: Supported in part by NIH AG18031, NS23002 and the EENT Foundation.
Does presence of R wave forces on surface electrocardiogram predict myocardial viability in patients with coronary disease and left ventricular dysfunction? Correlation with cardiac MRI.

Background Clinicians use presence of Q waves as a sign of transmural infarction although this is an imperfect marker to predict lack of myocardial viability (MV). We hypothesized that presence of R waves as a marker of electrical activity on surface electrocardiogram (ECG) may be a sensitive marker for presence of MV as determined by delayed enhanced cardiac magnetic resonance (DECMR) imaging.
Survey of Verticillium nonalfalfae (Phyllachorales) on tree-of-heaven in the southeastern USA

Ailanthus altissima (Mill.) Swingle commonly known as tree-of-heaven is an invasive tree species that has spread through much of the USA. Significant mortality of A. altissima by a highly host-specific strain of the fungus, Verticillium nonalfalfae Inderb. (formerly Verticillium albo-atrum Reinke and Bethold), has been recently documented in Pennsylvania. To detect the regional distribution of this biological control agent in the Southeast, a windshield survey was conducted in Virginia, North Carolina and South Carolina to locate V. nonalfalfae-infected A. altissima stands. The survey covered 26,500 km of interstate highways and primary and secondary roads. There were 90 potential sites located throughout the three states. Of those, six were found to be infested with the fungus, all in the mountain regions of Virginia. Inoculation tests suggest no difference in virulence among the six V. nonalfalfae isolates on A. altissima, which resulted in 100% mortality in 9–11 weeks post-inoculation. Tree ratings rev...
Mapping the spatial distribution of charge carriers in quantum-confined heterostructures

The confinement of electrical charges in quantum dots makes them of interest for applications in imaging and photovoltaics. Here, the authors demonstrate that based on optical absorption measurements and theoretical modelling it is possible to derive the charge carrier distribution in quantum dots.
A hierarchical neutral model for landscape analysis

Empirical studies have revealed scaled structure on a variety of landscapes. Understanding processes that produce these structures requires neutral models with hierarchical structure. The present study presents a method for generating random maps possessing a variety of hierarchical structures. The properties of these scaled landscapes are analyzed and compared to patterns on totally random, unstructured landscapes. Hierar-chical structure permits percolation (i.e., continous habitat spanning the landscape) under a greater variety of conditions than found on totally random landscapes. Habitat clusters on structured maps tend to have smaller perimeters. The clusters tend to be less clumped on sparsely occupied landscapes and more clumped in densely occupied conditions. Hierarchical structure changes the expected spatial properties of the landscape, indicating a strong need for this new generation of neutral models.
Phylogenetic analysis of the African papionin basicranium using 3-D geometric morphometrics: the need for improved methods to account for allometric effects.

The basicranium has been argued to contain a strong phylogenetic signal in previous analyses of primate cranial morphology. Therefore, further study of basicranial morphology may offer new insights into controversial phylogenetic relationships within primate groups. In this study, I apply 3-D geometric morphometric techniques in a phylogenetic analysis of the African papionin basicranium. The effects of allometry strongly influence African papionin basicranial morphology and, unless these size effects are controlled or eliminated, phylogenetic analyses suggest traditional phylogenetic groupings of small taxa (mangabeys) and large taxa (geladas, mandrills, drills, and baboons). When the effects of allometry are eliminated by excluding size-correlated principal components (PCs) or by regression analysis with retention of residuals, phylogenetic analyses of African papionin basicranial morphology are incongruent with recent molecular and morphological studies. By contrast, a cladistic analysis of basicranial characters using the narrow allometric coding method suggests the same phylogenetic relationships as recent molecular and morphological studies. These results suggest that important phylogenetic information is contained within the size-correlated data, and this information is being discarded during the attempt to eliminate the effects of body size. Future 3-D morphometric studies of phylogeny should focus on the development of new methodologies to adjust for allometric effects, as current techniques appear to be ill-equipped to deal with the case of a size-disparate, lower-level taxonomic group. Am J Phys Anthropol, 2010. © 2010 Wiley-Liss, Inc.
Astrocyte end-feet in germinal matrix, cerebral cortex, and white matter in developing infants

Astrocyte end-feet ensheathe blood vessels in the brain and are believed to provide structural integrity to the cerebral vasculature. We sought to determine in developing infants whether the coverage of blood vessels by astrocyte end-feet is decreased in germinal matrix (GM) compared with cerebral cortex and white matter (WM), which may cause fragility of the GM vasculature. Therefore, we evaluated the perivascular coverage by astrocyte end-feet in these areas. We double-labeled the brain sections with astroglial markers [glial fibrillary acidic protein (GFAP), aquaporin-4 (AQP4), and S-100beta] and a vascular marker, laminin. Perivascular coverage by GFAP+ astrocyte end-feet increased consistently as a function of gestational age (GA) in cortex and WM from 19 to 40 wk. Compared with GFAP, AQP4+ astrocyte end-feet developed at an earlier GA, ensheathing about 63% of blood vessels for 23-40 wk in cortex, WM, and GM. Coverage by GFAP+ perivascular end-feet was decreased in GM compared with cortex and WM from 23 to 34 wk. There was no difference in the coverage by AQP4+ end-feet among the three areas in these infants. The expression of AQP4, a water channel molecule, in the astrocyte end-feet was not significantly different between premature and mature infants, suggesting similar risk of brain edema in preterm and term infants in pathologic conditions. More importantly, the lesser degree of GFAP expression in astrocyte end-feet of GM compared with cortex and WM may reflect a cytoskeletal structural difference that contributes to the fragility of GM vasculature and propensity to hemorrhage.
Characterization of Several Clonal Lines of Cultured Ley dig Tumor Cells: Gonadotropin Receptors and Steroidogenic Responses*

Several clonal lines of cultured Leydig tumor cells have been established and characterized in terms of gonadotropin receptors and steroid production. Although freshly isolated cells derived from the M5480P tumor have functional hCG receptors, only two of the five clonal lines established were shown to bind significant quantities of hCG. In these clones, steroid production can be stimulated to the same extent by hCG, cholera toxin, and 8-Br-cAMP. The other three clones bind a small amount of hCG and respond to the hormone with a marginal increase in steroidogenesis. Steroid production, however, is significantly stimulated by cholera toxin or 8-Br-cAMP. A comparison of the steroids produced by freshly isolated cells and two of the clones revealed some changes in the steroidogenic pathway. The most obvious change is an increase in the ability of the cultured cells to synthesize 20α-dihydroprogesterone (20α-hydroxypregn-4-en-3-one). These clonal lines may provide a suitable model system for the study of gona...
Cooking Creoleness: Lafcadio Hearn in New Orleans and Martinique

Martinican creolist Raphael Confiant claims in an unabashed praise of Lafcadio Hearn that the nineteenth century writer “invented what today we might call ‘multiple identity’ or ‘creoleness’ [ creolite ].” Critic Chris Bongie notes that the word “creolization” appeared for the first time in the English language in Hearn’s 1890 novel Youma . In a letter written to his friend Henry Krehbel in 1883, Hearn himself announces this allegiance to all things creole as he signs “your creolized friend.” These comments identify the nineteenth century thinker not only as a precursor of creoleness , but more importantly, and also surprisingly, as a forerunner of both creoleness and creolization, two related terms that are philosophically unlike in Martinican thought.
RFLP and physical mapping with an rDNA-specific endonuclease reveals that nucleolus organizer regions of Arabidopsis thaliana adjoin the telomeres on chromosomes 2 and 4

Ribosomal RNA genes are organized in tandem arrays called nucleolus organizer regions (NORs). In a prior study, RFLP mapping on pulsed-field gels placed NOR2 at the northern tip of Arabidopsis thaliana chromosome 2. New polymorphisms have allowed the other NOR, NOR4, to be mapped to the northern tip of chromosome 4. To map NOR-associated loci, rDNA-specific cleavage by I-Ppol, an endonuclease with a 15 nucleotide recognition sequence involved in rDNA-homing of a mobile, self-splicing Group I intron in Physarum was exploited. I-Ppol digestion of A. thaliana genomic DNA liberated two telomere-containing fragments no larger than 13 kbp, and telomere polymorphisms identified using I-Ppol cosegregated with NOR2 and NOR4. Restriction mapping suggested that telomere-proximal rRNA genes are oriented with their 5' ends nearest the chromosome ends and their 3' ends nearest the centromere. This orientation was confirmed using the polymerase chain reaction to clone one of the telomere-rDNA junctions, most likely the junction on chromosome 4. The telomeric repeats join the terminal rRNA gene downstream of its promoter, suggesting that this first gene is inactive. Subtelomeric repetitive DNAs are absent at the telomere-rDNA junction. Localization of NOR2, NOR4 and their associated telomeres, TEL2N and TEL4N, respectively, provides end points for the genetic and physical maps of chromosomes 2 and 4.
Acquisition and retention of avoidance behaviors following septal lesions or scopolamine injections in rats

Scopolamine injections and septal lesions were found to have similar behavioral effects on both the acquisition and retention of a two-way avoidance task. However, on a jump-up task, these two manipulations did not have similar effects. Scopolamine impaired the acquisition of a jump-up avoidance such that the animals did not even learn the response, whereas septal lesions resulted in no change in acquisition of this task. Septal lesions prior to retention testing resulted in significantly shorter latencies to jump, but scopolamine injections were found to impair retention of this task. These results were interpreted to support the hypothesis that multiple functional systems may be represented within the septum.
X–1H rotational-echo double-resonance NMR for torsion angle determination of peptides

Abstract C–H and N–H rotational-echo double-resonance (REDOR) NMR is developed for determining torsion angles in peptides. The distance between an X spin such as 13C or 15N and a proton is measured by evolving the proton magnetization under REDOR-recoupled X–H dipolar interaction. The proton of interest is selected through its directly bonded heteronuclear spin Y. The sidechain torsion angle χ1 is extracted from a 13Cβ-detected Hβ–N distance, while the backbone torsion angle φ is extracted from an 15N-detected HN–C′ distance. The approach is demonstrated on three model peptides with known crystal structures to illustrate its utility.
Feasibility of Providing Sexually Transmitted Infection Testing and Treatment in Off-Campus, Nonclinic Settings for Adolescents Enrolled in a School-Based Research Project.

BACKGROUND This study examined the acceptability and feasibility of using a biological outcome measure to evaluate a school-based sexuality education program. Confidential field-delivered sexually transmitted infection (STI) testing by nonmedical field staff and STI treatment by medically trained field staff was assessed in off-campus and off-clinic settings for adolescents enrolled in the trial. METHODS After parental and adolescent consent were obtained, a convenient time and location was identified to collect urine to test for chlamydia (Chlamydia trachomatis, CT), gonorrhea (Neisseria gonorrheae, NG), and trichomonas (Trichomonas vaginalis, TV) infection and to treat students with positive results. RESULTS A total of 391 of 1742 students had permission to participate (22%); 353 (90%) provided urine samples; 28 (8%) had positive test results: CT(18), NG(5), and TV(8). Testing and treatment occurred at home for 92% and 59% of students, respectively; on weekdays (for 69% and 96%, respectively) and between noon and 8 pm (for 76% and 88%, respectively). All students who tested positive were treated. Several lessons and strategies that may improve the likelihood that students will participate in field-delivered STI testing and treatment emerged. CONCLUSION STI testing and treatment are feasible for students enrolled in a school-based sexuality education program. However, obtaining parental consent may be challenging.
A Failure to Hypnotically Produce Nocturnal Emissions

Abstract Although many studies have shown that subjects will verbally report nocturnal dreams containing hypnotically suggested content (Tart, 1972), demand characteristics and other nonspecific experimental effects make this data difficult to interpret. In an effort to alleviate dependence on subjective verbal reports three subjects were given hypnotic instructions to have a nocturnal emission involving suggested, sexually stimulating material. The subjects bed clothes showed no evidence of seminal stains following either night of experimental treatment, although one dream of symbolically sexual content was verbally reported. It is suggested that further research with dreams that have a measurable physical effect is necessary.
A Hybrid Intelligent Logistics Diagnostic Assistant

Artificial neural networks (ANN) are powerful tools for pattern matching and have proven useful in fault detection and diagnosis. Rule based systems (RBS) have the ability to process complex reasoning paths and explain the results of an analysis. The Hybrid Intelligent Logistics Diagnostic Assistant (HILDA) combines these technologies to augment the abilities of a logistics analyst. HILDA aids a logistics analyst working with the Mobility Aircraft Availability Forecasting (MAAF) simulation in trying to balance the requirements of a mission schedule versus the personnel and aircraft resources available at a set of airbases. This paper describes the design and implementation of the hybrid architecture, with details on the domain specific knowledge embedded in the ANN and RBS modules. Examples show how the HILDA prototype is successful in aiding a decision maker in converging to a successful mission/resource scenario.
Induction of micronuclei and aneuploidy by the quinone-forming agents benzene and o-phenylphenol

Abstract A number of carcinogens appear to exert their tumorigenic effects through the formation of quinone metabolites. These quinone-forrning carcinogens are generally inactive or weakly active in standard gene mutation assays. Accumulating evidence indicates that this class of compounds may exert their genotoxic and carcinogenic effects through the induction of large-scale genetic alterations. This article presents an overview of work that has been performed using recently developed molecular cytogenic techniques to investigate the aneuploidy-inducing and clastogenic properties of the major quinone-forming metabolites of benzene, a widely used industrial chemical, and o-phenylphenol, a fungicide and disinfectant. These metabolites of benzene (hydroquinone, catechol, and benzenetriol) and o-phenylphenol (phenylhydroquinone) have each been shown to be capable of interfering with chromosome segregation and inducing chromosomal breakage. These results indicate that both numerical and structural chromosomal aberrations induced by the quinone metabolites of benzene and o-phenylphenol may play a role in the carcinogenic effects of these two agents.
A computer‐based serials control system for a large biomedical library

Rather than reiterate the obvious purposes and procedures involved in creating a computer system for control of serials, in this paper the author deals with the concept upon which the UCLA system is based and the manner in which the system is maintained in day-to-day operations of the UCLA Biomedical Library. The paper deals with some of the points made in an earlier publication from the UCLA serials project. The attempt is to show how the theory of publication pattern (discussed in the earlier article) has been used to produce a different idea in computer control of serials. Publication pattern information which is entered into the master record for each title causes check-in cards for the next expected issue of each title to be generated by the computer, regardless of when this next issue is expected—next week, next month, next year. This is a departure from most systems, which attempt to predict a certain number of issues which should arrive during a given time period. The information, which must be a part of the computer record, is described, as are library procedures in maintaining the system.
Coloring Epistemologies: Are Our Research Epistemologies Racially Biased?

espected scholars of color have suggested (e.g., Stanfield, 1985, 1993a, 1994), even within the pages of this journal (J. A. Banks, 1993, 1995; Gordon, Miller, & Rollock, 1990), that the epistemologies we typically use in educational research may be racially biased. They have argued that our epistemologiesl-not our use of them, but the epistemologies themselves-are racially biased ways of knowing, implicitly proposing, thus, a new category of racism that could be labeled epistemological racism. There has been, however, a provocative lack of response-pro or con-to this race-oriented argument by leading educational methodologists in journals of education, including this one.2 But this lack of response is in curious contrast to the lively and contentious debates on other epistemological issues, such as quantitative versus qualitative (e.g., Cizek, 1995), objectivity versus subjectivity (e.g., Heshusius, 1994), validity (e.g., Lenzo, 1995; Moss, 1994), or paradigmatic issues in general (e.g., Bereiter, 1994; Delandshere & Petrosky, 1994; Gage, 1989). If we were among those raising this race-oriented issue, we would wonder why our efforts to argue that the epistemologies of educational research were racially biased provoked virtually no response, particularly among those who author the quantitative and qualitative research methods textbooks we all typically use. We would certainly wonder whether our argument was ignored because it raised the disquieting issue of race, because it was thought to be a weak or irrelevant argument, or because the argument was simply not understood. Unfortunately, we might also wonder whether this was just one more incidence of Ellison's (1972) "invisible man" syndrome, of Whites ignoring racial issues and people of color. As researchers whose race is White and who have
Natural Reproduction of Coho Salmon and Chinook Salmon in Some Michigan Streams

Abstract Sixty streams in lower Michigan were surveyed for natural reproduction of chinook salmon (Oncorhynchus tshawytscha) and coho salmon (Oncorhynchus kisutch) in 1976-1979. Most chinook reproduction was found in the larger trout streams. Coho salmon also reproduced in the larger trout waters but utilized more of the small tributary streams than did chinook salmon. A positive correlation was found between stream velocity and the amount of chinook salmon reproduction, with no reproduction found in stream areas where the water velocity was below 0.3 m/sec. The increased abundance of chinook salmon fry with increasing velocity may reflect better conditions for reproduction as gravels become coarser. An estimated 630,000 chinook salmon smolts were produced in Michigan's Lower Peninsula tributaries of Lake Michigan in 1979. This was 23% of the chinook smolt production in 1979 from Michigan waters (including hatchery plants). Where substantial reproduction or potential for reproduction is found in Great Lak...
Effect of single-crystal plastic deformation mechanisms on the dilatational plastic response of porous polycrystals

Abstract In this paper, the combined effects of texture and asymmetric single-crystal plastic deformation mechanisms on the dilatational response of voided polycrystals are assessed for the first time. To this end, a full-field dilatational viscoplastic Fast Fourier Transform (FFT)-based approach is used to generate gauge surfaces for porous polycrystals deforming by twinning at single crystal level, which are compared to yield surfaces obtained according to a recent analytical criterion for porous materials. Both approaches are cross-validated, revealing unusual features of the dilatational response, namely, a lack of symmetry of the surfaces with respect to both the hydrostatic and deviatoric axes. This strong sensitivity to the third invariant of the stress deviator is associated to the anisotropy and the tension–compression asymmetry of the plastic response of the matrix.
The distribution and proportions of vitamin A compounds during the visual cycle in the rat.

Radioisotopes and t.l.c. were used to indirectly determine the distribution and proportions of Vitamin A compounds in the rat eye. In the dark adapted eye there are Vitamin A compounds in the pigment epithelium; these compounds are likely within the rod outer segment discs being digested there. During light adaptation. 11-cis retinal decreases, alltrans retinal increases and is reduced to retinol, and retinol is esterified to fatty acids in the retina and in the pigment epithelium. Essentially the reverse occurs during dark adaptation. It is suggested that the metabolism of Vitamin A compounds in the eye functions to return chromophore to the newly synthesized visual pigment at the base of the rod outer segment.
Where is computing headed

Technological change is putting entire industries on the betting line. For computer technologists, these shifts can mean opportunity or disappointment as one technology is replaced by another. Therefore, it is important that we consider economic and technical forces when we plan for the future. By studying predictable technology and asking "what if" questions where developments are less certain, we can envision the state of computing in another 10 years. >
Effect of early skin-to-skin contact on mother-preterm infant interaction through 18 months: randomized controlled trial.

Abstract Background Preterm birth often negatively influences mother–infant interaction. Skin-to-skin contact postbirth has positive effects on maternal feelings toward their preterm infants and on infant development and family interaction. However, little is known about the long-term effects of skin-to-skin contact on mother–late preterm infant interaction when skin-to-skin contact was experienced early postbirth and intermittently throughout the next five days. Objective The purpose of this report was to examine the effect of skin-to-skin contact on mother–late preterm infant interaction through 18 months. Design Randomized controlled trial with follow-up. Setting Two hospitals in the United States of America. Participants 100 mothers and their late preterm infants, 32 to Methods Mothers and their preterm infants were videotaped during a feeding session at 6 and 12 months, and a teaching session at 6, 12, and 18 months. Their interactions were then scored using the Nursing Child Assessment Satellite Feeding Scale and Teaching Scale. Results Skin-to-skin contact and control dyads had comparable feeding scores at 6 and 12 months. Skin-to-skin contact infants had lower infant teaching scores at six months, a difference that disappeared thereafter. Conclusions These inconclusive results call for additional studies with larger doses of skin-to-skin contact, larger sample sizes, and other outcome measures of mother–late preterm infant interactions. Such measures include the Parent–Child Early Relational Assessment and behavioral coding during play.
Pancreatoduodenectomy: imaging and image-guided interventional treatment.

Abstract Though the mortality of pancreatoduodenectomy (Whipple surgery) is under 4%, the morbidity continues to be high. The interventional radiologist plays an important role in the management of postoperative complications, such as abdominal abscess, bilomas, liver abscess, biliary obstruction, pseudocyst, and hemorrhage. Identification of the normal postoperative anatomy is crucial to correctly interpreting CT scans for short- term complications and long-term tumor recurrence.
The occurrence of ergosterol in citrus

Abstract A Δ 5, 7, 22 sterol has been isolated from the peel of the citrus Rangpur lime and identified as ergosterol.
Three New Species of Eimeria (Apicomplexa: Eimeriidae) from Nerodia rhombifem (Serpentes: Colubridae) from Texas1

Three new species of Eimeria (Apicomplexa: Eimeriidae) are described from the intestinal contents of Nerodia rhombifera (Serpentes: Colubridae) from Texas. Oocysts of Eimeria infirmus are irregular in shape, 11.6 (8.8–14.4) μm in diameter, with a smooth, thin wall that ruptures easily, releasing free sporocysts. A small polar granule is usually present, but a micropyle and oocyst residuum are absent. Sporocysts are bean-shaped with one side flattened slightly, 9.1 times 5.0 (7.2–10.4 times 4.4–5.8) μm, with what may be a Stieda body consisting of a slight thickening of one end of the sporocyst. Each sporocyst contains a spherical or ellipsoid residuum and sporozoites, each with a single, posterior refractile body. Oocysts of Eimeria rhombifera are spherical or subspherical, 13.1 times 12.6 (12.0–14.4 times 11.2–14.4) μm, with a smooth, frail wall. A polar granule is present, but a micropyle and oocyst residuum are absent. Sporocysts are ovoid, 8.8 times 5.5 (8.0–9.6 times 5.0–6.0) μm, each with a Stieda body. Each sporocyst contains a spherical or subspherical residuum and sporozoites, each with a single posterior refractile body. Oocysts of Eimeria tenuis are ellipsoidal in shape, 17.2 times 10.8 (15.2–20.8 times 9.6–12.0) μm, with a smooth, thin wall. A polar granule and oocyst residuum are present, but a micropyle is absent. Sporocysts are elongate, 13.2 times 4.9(11.2–15.2 times 4.4–5.6) μm, each with a Stieda body consisting of a thickening of the sporocyst wall. Each sporocyst contains a spherical or subspherical residuum and sporozoites with anterior and posterior refractile bodies.
Structural and catalytic effects of proline substitution and surface loop deletion in the extended active site of human carbonic anhydrase II.

UNLABELLED Bioengineering of a thermophilic enzyme starting from a mesophilic scaffold has proven to be a significant challenge, as several stabilizing elements have been proposed to be the foundation of thermal stability, including disulfide bridges, surface loop reduction, ionic pair networks, proline substitutions and aromatic clusters. This study emphasizes the effect of increasing the rigidity of human carbonic anhydrase II (HCA II; EC 4.2.1.1) via incorporation of proline residues at positions 170 and 234, which are located in surface loops that are able to accommodate restrictive main-chain conformations without rearrangement of the surrounding peptide backbone. Additionally, the effect of the compactness of HCA II was examined by deletion of a surface loop (residues 230-240) that had been previously identified as a possible source of thermal stability for the hyperthermophilic carbonic anhydrase isolated from the bacterium Sulfurihydrogenibium yellowstonense YO3AOP1. Differential scanning calorimetry analysis of these HCA II variants revealed that these structural modifications had a minimum effect on the thermal stability of the enzyme, while kinetic studies showed unexpected effects on the catalytic efficiency and proton transfer rates. X-ray crystallographic analysis of these HCA II variants showed that the electrostatic potential and configuration of the highly acidic loop (residues 230-240) play an important role in its high catalytic activity. Based on these observations and previous studies, a picture is emerging of the various components within the general structural architecture of HCA II that are key to stability. These elements may provide blueprints for rational thermal stability engineering of other enzymes. DATABASE Structural data have been submitted to the Protein Data Bank under accession numbers 4QK1 (K170P), 4QK2 (E234P) and 4QK3 (Δ230-240).
A multi-period mixed integer linear programming model for water and energy supply planning in Kuwait

The demand for water often necessitates desalination, particularly in arid coastal environments. Desalination is often integrated with electrical cogeneration. The demands for water and electricity change over time and are subject to uncertainty. A country-wide large-scale energy and water cogeneration planning model for Kuwait is formulated as a multi-period mixed integer linear programming problem and solved to minimize the net present value over the time period of 2013–2050. Five different plant technology options were considered for desalination and cogeneration including Oil & Multi Stage Flash, Natural Gas & Multi-Effect Distillation, Natural Gas & Reverse Osmosis, Solar Energy & Multi-Effect Distillation, and Solar Energy & Reverse Osmosis. Both water and energy usage in Kuwait and data from existing plants were utilized in providing the parameters and forecasts necessary for solution of the mathematical programming model. The model provides technology choice and associated capacity decisions for existing plants, new plants at green sites, and existing plant capacity expansions as well as their timing to meet the demands.
Changing English in Contemporary Pacific Literature

AbstractAuthentic Pacific literature written by Pacific islanders began to emerge about 1970 and to overwrite the perspectives and stereotypes that had characterized colonial narratives set in the Pacific written prior to that time. Writers of authentic Pacific literature adapted the Standard English code to create a new English with which to express their own cultures and identities in a language different than the English used by their colonizers. New Englishes created by Pacific island writers incorporate into the Standard English code such elements as untranslated vocabulary from indigenous languages; non-verbal communication strategies used by indigenous Pacific islanders; broken English syntax; indigenous language patterns and discourse elements; forms and features from a pre-colonial indigenous oral tradition including repetition, eulogy, and oratory; and powerful images of post-coloniality including images that celebrate difference and contest essentializing identities and social constructions of ...
Isoleucylation of transfer RNAfMet (E. coli) by isoleucyl-transfer RNA synthetase from Escherichia coli

Abstract Isoleucyl-transfer RNA synthetase from Escherichia coli is capable of the synthesis of Ile-tRNA1Met (E. coli). This is, then, a second example of intraspecific misacylation ( Yarus, 1972a ). This reaction is like that found previously for synthesis of IIe-tRNAPhe (E. coli) ( Yarus, 1972a ), and extends the conclusions of that work: (1) Transcognate acylation within a species occurs at a measurable rate under normal in vitro conditions. (2) The stimulation of this type of reaction by methanol is as expected if the major effect of the mixed solvent is to loosen the conformation of tRNA and enhance its strength of binding (Yarus, I972c) by helping it to adapt to the protein's surface. (3) The protein is also less selective among tRNA's in 20% methanol. Therefore, methanol does not stimulate binding of all tRNA'a equally; rather, a part of the mechanism responsible for discrimination against non-cognates is evaded when methanol is added. (4) The behavior of the system suggests that the free energy of interaction of tRNA's with isoleucyl-tRNA synthetase may be divided into a part specific to tRNAIle, and a part shared with other (non-cognate) tRNA's. Thus, structures common to several tRNA's, as well as those unique to cognates, may be implicated in the interactions.
Structural characterization of rapidly solidified white cast iron powders

Three white cast iron alloy powders (2.4% C, 3.0% C, and 3.0% C + 1.5% Cr) manufactured by a rapid solidification processing technique were investigated. It was found that the microstructures of all three alloy powders were similar. The primary constituent of these powders was found to be retained austenite. Only small amounts of carbide and martensite were found in the rapidly solidified white cast iron powders. The primary austenite cells and dendrites that nucleate and grow from the melt are retained upon cooling to room temperature with little carbide precipitation. The low volume fraction of marensite found was due to the high carbon concentration of the austenite. A fine dispersion of carbides in an austenite matrix is formed as a result of the solidification of the eutectic liquid in the intercellular and interdendritic regions. The relative proportion of primary austenite to eutectic can be explained by the carbon segregation that occurs during the solidification of the primary austenite. Annealing of the powders at 650° C transforms the metastable austenite into alpha iron and carbide. The carbides have a bimodal distribution with small carbides precipitating within the primary austenite cells and dendrites and large carbides precipitating within the intercellular and interdendritic regions.