cssi/SciSciGPT-SciSciNet huggingface dataset:
The significance of linearity of quantities in electrophoresed and blotted materials demonstrated by BandScan/spl copy/ - an analytical program

There is still an undervalued need for quantitation in the biological, biochemical, and the molecular genetic sciences. Quantitation of electroblotted materials such as DNA, RNA, and proteins and the quantitation of molecular weights in electrophoresed gels is often necessary to an undistorted analysis. Quantitation would ensure, for instance, that the quantities of the substances being assayed fall within the linear range of that method by which they are being studied, once the linear range has been determined by a linearity study: the common phenomenon of saturation and its reverse, insufficient samples, could be easily detected. A biological data representation program is discussed that converts the results of gels and blots to numerical values and presents these values in a graphical display that is amenable to meaningful comparisons. The main goal of this work is to be able to quantitate electrophoresed and blotted molecular and biochemical results while insuring that the samples processed are within the linear range of the methods employed. This study demonstrates errors that can occur when a linearity study is not conducted. Versatile, easy-to-use quantitative graphics programs, such as the BandScan program, can further pipe numerical output to spreadsheets or statistical packages and provide the bridge between modern computation and traditional wet lab techniques. This analytical bioinformatics program that allows for statistical analysis is also a valuable tool for teaching purposes in Bioinformatics and Molecular Biology. BandScan is available free for academic institutions and class room work from the corresponding author.
Connections between computation trees and graph covers

Connections between graph cover pseudocodewords and computation tree pseudocodewords are investigated with the aim of bridging the gap between the theoretically attractive analysis of graph covers and the more intractable analysis of iterative message-passing algorithms that are intuitively linked to graph covers. Both theoretical results and numerous examples are presented.
Synthesis of titanium dioxide particles in supercritical CO2

Abstract Spherical particles of titanium dioxide, anatase, were prepared in a supercritical carbon dioxide medium from titanium alkoxides and water. The dissolution of the alkoxide and stabilization of water dispersions in supercritical CO2 were found to be required for the formation of spherical particles. An anionic fluorinated surfactant was used to stabilize water dispersions in supercritical CO2. This could not be realized with hydrocarbon-based surfactants. The solubility of titanium alkoxides in CO2 appears to parallel their vapor pressure which is dependent on the oligomerization of the unhydrolyzed alkoxides. The polydispersity in particle sizes is due to nucleation occurring simultaneously with particle growth, owing to changes in the degree of supersaturation during the transition from the liquid to the supercritical state.
Decreased resistance to bacterial infection and granulocyte defects in IAP-deficient mice

Granulocyte [polymorphonuclear leucocyte (PMN)] migration to sites of infection and subsequent activation is essential for host defense. Gene-targeted mice deficient for integrin-associated protein (IAP, also termed CD47) succumbed to Escherichia coli peritonitis at inoccula survived by heterozygous littermates. In vivo, they had an early defect in PMN accumulation at the site of infection. In vitro, IAP-/- PMNs were deficient in beta3 integrin-dependent ligand binding, activation of an oxidative burst, and Fc receptor-mediated phagocytosis. Thus, IAP plays a key role in host defense by participating both in PMN migration in response to bacterial infection and in PMN activation at extravascular sites.
1-diphenylphosphonio-1-methoxymethyllithium, a useful reagent for the synthesis of aldehydes from hindered ketones

Abstract A new reagent, 1-diphenylphosphonio-1-methoxymethyllithium, has been found to be highly effective for the transformation R2CO → R2CHCHO with sterically hindered, enolizable ketones.
The effects of glucocorticoids on metabolic balance of diabetics.

SummaryThe effects of a single high dose of prednisone on alternate days on the metabolic balance of 20 diabetic subjects was studied. Only four subjects converted from a positive to a negative nitrogen balance. No consistent trend was noted in balances of sodium, potassium, and calcium.
Redundancy Resolution of Robotic Manipulators Using Normalized Generalized Inverses

A dynamical formulation based upon the undetermined force method is presented for analyzing redundant robotic manipulators. The equivalence between this dynamical formulation and the general solution of kinematic constraint equations is then obtained through use ofa normalized generalized inverse. This leads to a special form of the dynamical equations, called the N-inverse form of the dynamical equations. A class of problems, associated with the optimization of quadratic objective functions, are then studied. We find that the N-inverse form of the dynamical equations is the solution of this class of problems. Examples, including local minimization of joint torques and global minimization of kinetic energy, are presented.
OXYGEN TOXICITY: COMPARISON OF LUNG BIOCHEMICAL RESPONSES IN NEONATAL AND ADULT RATS

Although immature animals have long been known to be less susceptible to O2, toxicity than adults, the basic mechanism(s) to explain this phenomenon remains unresolved. Two biochemical mechanisms for protection of the lung from O2-induced injury have been proposed: the glutathione (GSH) system in reducing toxic lipid peroxides and the superoxide dismutase (SOD) system in eliminating superoxide anion. Experiments were carried out to determine whether these lung defense systems respond differently in neonatal and adult rats exposed to toxic concentrations of O2. Neonatal rats (4 to 7 days old) and adult rats (250-300 g) wire continuouly exposed to either 96-98% )2 or room air in monitored exposure chambers. All the O2-exposed adult rats showed extensive pulmonary edema and 65% died within 3 days of O2 exposure. Neonatal rats, however, all survived up to 5 days of O2 exposure without gross evidence of lung edema. During the course of exposure animals were sacrificed for biochemical analysis and the data expressed on a per lung basis as % of control values. After 72 hours of O2, exposure neonatal rats showed increased activity of GSH (171%), GSH-peroxidase (GP) (126%), GSH-reductase (GR) (120%). glucose-6-phosphate dehydrogenase (G-6-PD) (139%), and SOD (114%). Adult rats, however, failed to show increases in pulmonary GSH, GP, GR, and SOD activity. Thus, the resistance of the neonatal lung to O2-induced injury may be due to the augmented activity of these protective enzyme systems. (Supported by GM 12675 and NIH 1F32 HL05415.)
Public attitudes toward fetal diagnosis and the termination of life.

As measured in two recent national surveys, public attitudes toward prenatal genetic testing are overwhelmingly favorable, and attitudes toward genetic testing in general are also predominantly favorable on both surveys. Unlike genetic testing, however, abortion in case of fetal defect is endorsed by only a minority of both samples. The unreliability of the scales used to measure these attitudes in both surveys suggests that attitudes toward fetal diagnosis and genetic testing have not yet crystallized. In part, this unreliability undoubtedly reflects the nature and number of the questions asked; but in part the low reliability of the scale seems to reflect the novel subject matter and the public's lack of familiarity with it. At present, attitudes toward prenatal diagnosis and testing appear to be distinct from attitudes toward abortion and the termination of life. But attitudes toward prenatal testing predict attitudes toward the termination of life, and vice versa. Thus, as the public becomes more knowledgeable about the new technology and its implications, there is at least the potential for these two attitudes to become more closely linked in the future.
TWO CHEERS FOR TOUTS

A common belief among economists is that the activity of touts (scalpers) is unambiguously beneficial to the market. This note shows that that intuition is in general incorrect. Touts' presence in the market dilutes any individual's chance of obtaining a ticket in the original distribution. It is shown that if transactions costs cannot be pushed high enough to eliminate the resale market, the best policy is to leave touts alone. However, when possible, killing the resale market unambiguously benefits many ticket buyers, including some of the touts and their clients. Copyright 1993 by Scottish Economic Society.
COMPOUND-STATE RESONANCES IN ATOM--DIATOMIC MOLECULE COLLISIONS.

Compound state resonances in atom/molecule collisions below first excitation threshold energy
Pregnancy in women with coarctation of the thoracic aorta

Summary In summary, significant coarctation of the aorta during pregnancy in the unoperated setting carries an increased risk of morbidity and mortality both to mother and fetus and therfore, is contraindicate until adequate surgical intervention has been carried out. Previously operated patients need to be carefully screened fromthe cardiovascular stand-point before pregnancy. The risk of pregnancy is substantially reduced after successful coarctation repair, however, it is not negligible.
Axonal patterns in olfactory cortex after olfactory bulb removal in newborn rats

Abstract The degeneration pattern in olfactory cortex following lesions within this region is described in mature rats, of which some had one olfactory bulb removed at birth. The observations suggest that the intracortical pathway reinnervates the distal parts of apical dendrites that had been deafferented by the neonatal lesion.
Induction of melanoma cell apoptosis and inhibition of tumor growth using a cell-permeable Survivin antagonist

The inhibitor of apoptosis gene family member Survivin is highly expressed in most tumors, and appears to be a promising target for cancer therapy. Although a variety of Survivin antagonists have been shown to induce apoptosis in malignant cells, the potential utility of these agents is limited by inefficient delivery and cell impermeability. We generated recombinant fusion proteins containing the TAT protein transduction domain and either wild-type Survivin (TAT-Surv-WT) or a dominant-negative mutant (TAT-Surv-T34A). The TAT-Surv proteins were purified by sequential affinity and ion-exchange chromatography, and at 30 nM concentration demonstrated rapid entry into cells at 30 min. Whereas TAT-Surv-WT had minimal effect on YUSAC2 or WM793 melanoma cells, TAT-Surv-T34A induced cell detachment, DNA fragmentation, caspase-3 activation and mitochondrial release of apoptosis-inducing factor at low microM concentrations. Intraperitoneal (i.p.) injection of mice bearing subcutaneous YUSAC2 xenografts with TAT-Surv-T34A (10 mg/kg) was associated with rapid tumor accumulation at 1 h, and increased tumor cell apoptosis and aberrant nuclei formation in situ. Repeated i.p. injection of TAT-Surv-T34A resulted in a 40-50% reduction in growth and mass of established tumors, compared to those similarly injected with saline buffer or TAT-Surv-WT. These studies demonstrate the feasibility of systemic tumor treatment using a cell-permeable Survivin antagonist.
Fatigue behavior of laser welds in lap-shear specimens of high strength low alloy steel sheets

Abstract In this paper, the fatigue behavior of laser welds in lap-shear specimens of non-galvanized SAE J2340 300Y high strength low alloy (HSLA) steel sheets is investigated based on experimental observations and a fatigue life estimation model. Optical micrographs of the laser welds before and after failure under quasi-static and cyclic loading conditions are examined. The micrographs show that the failure modes of laser welds under quasi-static and cyclic loading conditions are quite different. Under quasi-static loading conditions, the weld failure appears to be initiated from the base metal near the boundary of the base metal and the heat affected zone at a distance to the pre-existing crack tip, and the specimens fail due to the necking/shear of the lower left load carrying sheets. Under low-cycle loading conditions, the weld failure appears to be initiated from the pre-existing crack tips and the specimens finally fail from the ductile fracture through the lower left load carrying sheets. Under high-cycle loading conditions, the weld failure appears to be initiated from the pre-existing crack tips and the specimens finally fail from the kinked fatigue crack propagating through the upper right load carrying sheets. Finite element analyses of the laser welded lap-shear specimens with consideration of the weld bead protrusion were carried out to obtain the global and local stress intensity factor solutions for the main cracks and kinked cracks, respectively. The stress intensity factor solutions can be used to explain the kinked fatigue crack growth patterns under high-cycle loading conditions. The kinked fatigue crack growth model based on the global and local stress intensity factor solutions for finite kinked cracks obtained from the finite element analyses is adopted to estimate the fatigue lives of the laser welds. The fatigue life estimations based on the kinked fatigue crack growth model agree well with the experimental results.
Development of large die fine pitch flip chip BGA using TCNCP technology

Recently, technologies related to Fine Pitch Flip Chip or FPFC have been great achievements for various next generation devices, allowing a significant increase in the number of signal I/O and achieving low form factor packages. Consequently, fine pitch Cu pillar flip chip Chip Scale Package (CSP) with small sized die, with package dimension of less than 16×16mm, is already under high volume production using the Thermal-Compression Bonding with Non-conductive Paste (TCNCP) technology [1–2]. In the case of Flip Chip Ball Grid Array (FCBGA), there is a growing need for FPFC technology with Cu pillar in supporting next generation silicon node. However, there will be a high possibility of yield drop issue in conventional mass-reflow process and potential reliability due to the highly concerned tensile stress between low k die and substrate by CTE mismatch especially at the edge of the die. This can be a critical quality issue for fine pitch devices compared to normal pitch (i.e., 150um) flip chip BGA. Therefore, TCNCP bonding as an alternative should be studied on fine pitch Cu pillar flip chip BGA. This paper will discuss fine pitch flip chip assembly technology for large sized flip chip BGA. Two kinds of assembly method, mass reflow bonding versus thermal compression bonding, for the flip chip bonding will be compared for the large FPFCBGA package. Meanwhile, the advantage of TC bonding with pre-applied underfill process will be described. For robust interconnection between die and substrate for large FPFCBGA, the result of the bonding test will be described with several surface finishes such as ENEPIG, Direct Immersion Gold (DIG), Immersion Tin (IT), and Solder Coating on substrate. Interestingly, one of selected surface finishes has shown excellent reliability test results. Finally, this paper will discuss an effective approach for fine pitch devices from an assembly perspective.
Correlation filters for large population face recognition

Reliable person recognition is important for secure access and commercial applications requiring human identification. Face recognition (FR) is an important technology being developed for human identification. Algorithms and systems for large population face recognition (LPFR) are of significant interest in applications such as watch lists and video surveillance. In this paper, we present correlation filter-based feature analysis methods that effectively exploit available generic training data to represent a large number of subjects and thus improve the performance for LPFR. We first introduce a general framework - class-dependence feature analysis (CFA), which uses correlation filters to provide a discriminant feature representation for LPFR. We then introduce two variants of the correlation filter-based CFA methods: 1) the kernel correlation filter CFA (KCFA) that generates nonlinear decision boundaries and significantly improves the recognition performance without greatly increasing the computational load, and 2) the binary coding CFA that uses binary coding to reduce the number of correlation filters and applies error control coding (ECC) to improve the recognition performance. These two variants offer ways to tradeoff between the computational complexity and the recognition accuracy of the CFA methods. We test our proposed algorithms on the face recognition grand challenge (FRGC) database and show that the correlation filter-based CFA approach improves the recognition rate and reduces the computational load over the conventional correlation filters.
The cultural nature of tephra: `Problematic' ecofacts and artifacts and the Barú volcano, Panamá

Abstract This paper presents data from archaeological stratigraphy and lacustrine core samples containing tephra from the Baru volcano in western Panama. The discussion seeks to refine the understanding of medial tephra deposits near Baru in relation to the eruption history indicated by geological, palaeoecological, and archaeological data. A primary goal of this fieldwork is the identification and correlation of tephra from major Baru eruptions encountered in archaeological contexts by their lithology, stratigraphic position, and mineralogy without resorting to geochemical fingerprinting. The intention is to develop a cost efficient and reproducible means of utilizing tephra as a chronostratigraphic marker in archaeological contexts and examine the intersection of human life with volcanic events and dynamic environments. Tephra in archaeological contexts can have ambiguous placement between ecofact and artifact, as is the case with a small number of crude tephra sculptures in my excavated material and that of a seminal prior study. While the research project utilizes visible tephra layers, not cryptotephra, by all means the tephra data prove to be cryptic. Engagement with the imperfection entailed in meshing multidisciplinary data sets and different scientific communities with interests in tephra, particularly in lesser studied regions, is posited as a ‘total’ view of tephra.
Scheduling-Capable Autonomic Manager for Policy Based IT Change Management System

Managing large IT environments consisting of thousands of computers, routers, switches, and printers from different vendors is expensive and labor intensive. A typical piece of equipment goes through several planned and unplanned software and hardware upgrades. Maintaining and upgrading with minimal disruption and administrative support is a challenging task. One problem faced by IT administrators, in this change management process, is to arrive at a schedule for applying one or more change requests to the IT infrastructure. In this paper, the focus is on the problem of scheduling the change requests in the presence of organizational policies governing the use, access and availability of the IT infrastructure, we provide two approaches to scheduling and describe an implementation of a scheduler which shows the feasibility of our approach. The implementation is integrated with an autonomic manager described in earlier papers [1].
Negative selection systems for transgenic barley (Hordeum vulgare L.): Comparison of bacterial codA- and cytochrome P450 gene-mediated selection

Summary Efficient negative selection systems are increasingly needed for numerous applications in plant biology. In recent years various counter-selectable genes have been tested in six dicotyledonous species, whereas there are no data available for the use of negative selection markers in monocotyledonous species. In this study, we compared the applicability and reliability of two different conditional negative selection systems in transgenic barley. The bacterial codA gene encoding cytosine deaminase, which converts the non-toxic 5-fluorocytosine (5-FC) into the toxic 5-fluorouracil (5-FU), was used for in vitro selection of germinating seedlings. Development of codA-expressing seedlings was strongly inhibited by germinating the seeds in the presence of 5-FC. For selecting plants in the greenhouse, a bacterial cytochrome P450 mono-oxygenase gene, the product of which catalyses the dealkylation of a sulfonylurea compound, R7402, into its cytotoxic metabolite, was used. T1 plants expressing the selectable marker gene showed striking morphological differences from the non-transgenic plants. In experiments with both negative selectable markers, the presence or absence of the transgene, as predicted from the physiological appearance of the plants under selection, was confirmed by PCR analysis. We demonstrate that both marker genes provide tight negative selection; however, the use of the P450 gene is more amenable to large-scale screening under greenhouse or field conditions.
Evaluation of Pollution Loadings from Urban Nonpoint Sources: Methodology and Applications

In preparation of remedial action plans for the St. Clair, Detroit, and St. Marys rivers, a planning-level methodology for evaluation of pollutant loadings from urban nonpoint sources was developed and applied in three Canadian cities: Sarnia, Sault Ste. Marie, and Windsor. This methodology uses computed annual volumes of runoff and mean constituent concentrations, estimated from field sampling, to produce estimates of annual pollutant loadings. For the constituents studied, the total loadings were predominantly from point sources in about three quarters of all cases. For some of the less common substances, occurring at low levels, the nonpoint sources contributed loadings which were comparable to or even higher than those from point sources. Such findings will be useful in the development of remedial action plans which need to focus on control of pollutant sources.
Second cross virial coefficients for interactions involving water. Critical data compilation

Values of the second cross virial coefficients, B12, and isothermal Joule−Thomson coefficients, φ12, for interactions involving water are compiled and, as necessary, evaluated from existing experimental data including PVT properties of gas mixtures, measurements of the pressure dependence of the molar excess enthalpies of a gas mixture, and measurements of the solubility of the condensed phases of H2O (liquid water or ice) in compressed gases. In all, there are data for interactions between water and 32 other compounds, and among these, nine interactions involve compounds with appreciable dipole moments. These B12 values, typically available over a limited temperature range, are extrapolated to high temperatures by means of the Tsonopoulos corresponding-states correlation. Finally, the temperature dependence of the second cross virial coefficients between water and solutes at temperatures up to 1200 K is approximated by an empirical polynomial equation, the coefficients of which are tabulated for each int...
Expression of HLA-DR Antigen on Retinal Pigment Epithelial Cells in Retinitis Pigmentosa

Class II (HLA-DR) antigens are cell surface molecules that play a major role in the initiation and perpetuation of immune responses. Although most cells do not constitutively express class II antigens, selected cells can be stimulated to do so in some immunologically mediated disorders. When retinal pigment epithelial cells were evaluated by either immunoperoxidase or immunofluorescent staining of frozen eye sections from normal individuals, HLA-DR antigens were not detected. In contrast, retinal pigment epithelial cells from two patients with retinitis pigmentosa did express HLA-DR antigens. These findings demonstrated that at some time during the course of retinitis pigmentosa, the retinal pigment epithelial cell is activated to express HLA-DR.
When the positivity of the leading principal minors implies the positivity of all principal minors of a matrix

Abstract An n-by-n real matrix A enjoys the “leading implies all” (LIA) property, if, whenever D is a diagonal matrix such that A + D has positive leading principal minors (PMs), all PMs of A are positive. Symmetric and Z-matrices are known to have this property. We give a new class of matrices (“mixed matrices”) that both unifies and generalizes these two classes and their special diagonal equivalences by also having the LIA property. “Nested implies all” (NIA) is also enjoyed by this new class.
Creating access to land grant resources for multicultural and disadvantaged farmers

The fastest growing demographic sectors of Washington agriculture are Latino, Asian, and women farmers. The majority of these farms are small, with over three-fourths of Latino, Hmong, or women-operated farms having fewer than 50 acres and less than $50,000 in sales. Small farms make up 90 percent of all Washington farms, with 35,269 counted in the last census. Unfortunately, most conventional farming education models are not well-suited to farmers with limited access to land, water, and capital, or with limited literacy or limited English proficiency. Meeting the needs of this new generation of farmers will require rethinking many standard approaches to public agricultural research, education, and assistance. This article examines various alternative formats for reaching diverse producers with sustainable farming education that have been piloted by the Washington State University Small Farms Program, including participatory courses, farmer-to-farmer learning strategies, experiential workshops, audio­visual strategies, and simultaneous translation.
Tolerance induction for solid organ grafts with donor-derived hematopoietic reconstitution

Tolerance of transplanted tissue has been a focus of immunologists for decades. Indeed, to some the birth of immunology and the search for tolerance of the non-self are synonymous. One of the most powerful and reproducible methods of tolerance induction to allogeneic tissue has involved infusion of donor-specific hematopoietic cells. Under certain conditions, such infusion can result in hematopoietic reconstitution that can be experimentally accomplished at a variety of different time-points in the life of an organism from the in utero period through adulthood, reconstitution at each time-point involving consideration of a different set of immunological and physiological parameters. When high levels of donor-derived hematopoietic reconstitution are achieved, tolerance induction to donor-specific antigens is reproducible and long-lasting. Unfortunately, however, clinical efforts to achieve such high levels of hematopoietic reconstitution have historically been unsuccessful or fraught with complications. Transplantation efforts have been plagued by failure of engraftment, graft-vs-host disease (GVHD), or severe immunoincompetence of the recipient. Laboratory and clinical efforts during the last decade have resulted in a variety of developments that may overcome these barriers: (1) methods have been devised in which cells that cause GVHD can be depleted from the hematopoietic graft while hematopoietic reconstitution potential is preserved, (2) methods of harvesting large numbers of cells with multilineage reconstitution potential have been devised (an accomplishment that seems to allow the immunological barrier to be overwhelmed), and (3) capitalizing on the above two principles, minimally toxic preconditioning regimens have been designed that allow allogeneic engraftment. This review will focus on some of the experimental and clinical data of the past and the experimental and clinical issues that loom ahead.
EFFECTS OF PRACTICE AND POSITIONAL VARIABLES IN ACQUISITION OF A COMPLEX PSYCHOMOTOR SKILL

40 Navy subjects practiced a three-dimensional tracking task in two positions (the apparatus either in front of, or above, the subject) under distributed and massed practice schedules to determine the effects of these variables on acquisition of skill. Distributed and massed practice were defined in terms of trial (4 1/2 and 9 min.) and session (1 and 2 hr.) lengths with the subjects equally divided into these four groups: distributed trials, distributed sessions; distributed trials, massed sessions; massed trials, distributed sessions; and massed trials, massed sessions. Total training (practice and rest) time was identical for all groups. Results indicated that task position was a relevant variable in acquisition of skill, i.e., different practice schedules were optimal for the two positions studied.
Dynamics and Instability of Electron Phase-Space Tubes

Two-dimensional simulations of beam-driven turbulence in the auroral ionosphere have shown the formation and instability of phase-space tubes. These tubes are a generalization of electron phase-space holes in a one-dimensional plasma. In a strongly magnetized plasma, such tubes vibrate at frequencies below the bounce frequency of the trapping potential. A theory for these vibrations yields quantitative agreement with kinetic simulations. Furthermore, the theory predicts that the vibrations can become unstable when resonantly coupled to electrostatic whistlers -- also in agreement with simulations.
Progress in the development of μ+μ− colliders

We review the progress in the development of μ + μ − colliders, starting with the 1992 Napa meeting and continuing through this 1995 Fairmont Hotel meeting. In a very short time, the scientific justifications and preliminary design parameters have been assembled. However, there is much work to do to convince the scientific community that a μ + μ − collider is feasible, including: μ cooling studies, detector background studies, polarization, and development of a plan of R&D that leads to the realisation of a μ + μ − collider in the next century.
Bivalent hapten-antibody interactions—II. Bivalent haptens as probes of combining site depth

Abstract Carson and Metzger (1974)have shown that Fab′ fragments form dimer with bivalent hapten. The amounts of dimer formed with the fragments was similar to the amount formed with intact antibody and the same bivalent hapten. They concluded that the lenght of the bivalent hapten was a measure of combining site depth. In this communication, we extend these observations of Carson and Metzger by using a homologous series of bivalent haptens to study intact antibody molecules, F(ab′) 2 fragments, and Fab′ fragments. The results of these studies are consistent with the conclusions of Carson and Metzger, and the data enable us to construct a plot of the distribution of antibody dimers as a function of the chain length of the cross-linking bivalent hapten.
Fast cleavage kinetics of a natural hammerhead ribozyme.

The hammerhead ribozyme is a small RNA motif that catalyzes the cleavage and ligation of RNA. The well-studied minimal hammerhead motif is inactive under physiological conditions and requires high Mg2+ concentrations for efficient cleavage. In contrast, natural hammerheads are active under physiological conditions and contain motifs outside the catalytic core that lower the requirement for Mg2+. Single-turnover kinetics were used here to characterize the Mg2+ and pH dependence for cleavage of a trans-cleaving construct of the Schistosoma mansoni natural hammerhead ribozyme. Compared to the minimal hammerhead motif, the natural Schistosoma ribozyme requires 100-fold less Mg2+ to achieve a cleavage rate of 1 min-1. The improved catalysis results from tertiary interactions between loops in stems I and II and likely arises from increasing the population of the active conformation. Under optimum pH and Mg2+ conditions this ribozyme cleaves at over 870 min-1 at 25 °C, further demonstrating the impressive cataly...
Absence of phosphatidylinositol (PI)-linked proteins in a very early human multipotential haematopoietic marrow cell.

Summary A very early human haematopoietic progenitor cell population which was negative for the major histocompatibility class II antigen (HLA-DR) and positive for the CD34 (MY10) antigen was separated into two subsets according to the expression of decay-accelerating factor (DAF) on the cell surface. Using immunoadherence, cell cycle analysis, and cell culture, we determined that there is a DAF− multipotential cell and a more differentiated DAF+ lineage specific progenitor cell existing in human bone marrow. The DAF+ subset was highly enriched for CFU-GEMM, while the DAF+ subset contained only BFU-E and CFU-GM. The DAF− subset was approximately 0·03% and the DAF+ subset approximately 0·0·08% of the original bone marrow population. MIRL (membrane-inhibitory of reactive lysis), another Pl-linked protein, was not expressed on the DAF− population but was expressed on the DAF+ cells. These observations indicate that PI-linked proteins are absent from the multipotential stem cell but are present on an early lineage specific cell. The absence of expression of PI-linked proteins can be used to further isolate and characterize a very early multipotential haematopoietic progenitor cell population.
TOR Signaling and S6 Kinase 1: Yeast Catches Up

Conservation of the rapamycin-sensitive TOR signaling network among eukaryotes has been instrumental to the rapid progress made in this field in recent years. A recent report in Molecular Cell (Urban et al., 2007) now extends this conservation to include Sch9, an AGC protein kinase family member from S. cerevisiae, which appears to be the long sought after yeast ortholog of mammalian S6 kinase 1 (S6K1) and a direct target for the rapamycin-sensitive TOR complex I.
Transcript profile of CD4+ and CD8+ T cells from the bone marrow of acquired aplastic anemia patients

Objective Immune-mediated destruction of hematopoietic stem and progenitor cells is pathophysiologic in most cases of aplastic anemia (AA). We have successfully determined the gene expression profile of the marrow CD34 + target cells in AA. T cells producing IFN-γ and TNF-α have been implicated in hematopoietic destruction in AA. We sought to characterize T cells as immune mediators using the microarray approach. Materials and Methods We applied Affymetrix GeneChip techniques to determine the detailed profile of mRNA expression of CD4 + and CD8 + cells from the BM of newly diagnosed AA patients and healthy volunteers. For validation, we confirmed our microarray results using quantitative real-time PCR. Results Compared to healthy controls, there were 178 and 183 differentially expressed genes in patients' CD4 + cells and CD8 + T cells, respectively; activities of 22 selected genes were confirmed using real-time PCR. Dysregulated genes included those encoding cytokines/chemokines, and involved in transcription regulation, calcium and ion channel formation, and cell adhesion. Unexpected findings were overexpression of toll-like receptor genes in marrow CD4 + cells of patients and of genes for killer-cell immunoglobulin-like receptors (KIR) in AA marrow CD8 + cells. Conclusions Our detailed results at the mRNA level provide insights into the mechanism of AA. Both innate and adaptive immune responses of CD4 + and CD8 + T cells appear to be active in immune-mediated marrow destruction. A variety of cytokines and chemokines active in pathophysiologic cells likely play important roles in the recruitment and activation of lymphocytes to cytotoxic effectors for marrow hematopoietic target cells in AA.
Direct observation of a tangent bifurcation in a nonlinear oscillator

Abstract We report the direct observation of a tangent bifurcation at the period-five window of a driven nonlinear semiconductor oscillator, by observing the fifth iterate of the dynamical variable of the system in real time. The tangent bifurcation is accompanied by an intermittency as predicted by Manneville and Pomeau.
Wannier Exciton in an Electric Field. II. Electroabsorption in Direct-Band-Gap Solids

The electric field and temperature dependence of excitonic electroabsorption is presented for direct-band-gap semiconductors and insulators. Each excitonic electroabsorption spectrum is characterized in terms of three energy parameters: (i) $R$, the binding energy of the exciton; (ii) $\ensuremath{\Gamma}$, the thermal broadening parameter; and (iii) $\ensuremath{\hbar}\ensuremath{\theta}$, the electro-optical energy. The relative magnitude of these three quantities determines which, if any, of the competing forces dominate. In comparison with the single-particle electroabsorption theory, the excitonic electroabsorption theory gives several new results. The electric field and temperature dependence of ${\ensuremath{\epsilon}}_{2}$, $\ensuremath{\Delta}{\ensuremath{\epsilon}}_{2}$, and $\ensuremath{\Delta}{\ensuremath{\epsilon}}_{1}$ are displayed. Fitting of the excitonic electroabsorption theory to lead iodide data gives the values of 2.58 eV for the direct gap in lead iodide and 0.21 electron masses for the reduced mass of the electron-hole pair associated with the extrema in the valence and conduction bands, as compared with previous values of 2.55 eV and 0.24 electron masses.
Effects of Cozymase upon Growth of Staphylococci and Anti-staphylococcal Action of Sulfonamide Compounds.

Summary1. Two samples of cozymase were tested, and each could replace both thiamin chloride and nicotinic acid, essential growth requirements for the staphylococcus; however, these preparations contained small quantities of thiamin. It has been shown that an adequate amount of thiamin was contained in the cozymase, which explains why maximum growth of staphylococci was obtained in the presence of cozymase, but in the absence of nicotinic acid. 2. When certain experimental conditions are fulfilled, cozymase, but not thiamin chloride and nicotinic acid, will inhibit the bacteriostatic action of sulfanilamide and sulfapyridine against staphylococci.
Effects of lecithin on thermally induced whey protein isolate gels

Abstract The effect of lecithin on fundamental fracture properties (true shear stress and true shear strain at fracture) and water holding capacity of heat-induced whey protein isolate (WPI) gels were investigated. Adding egg yolk lecithin to WPI gels substantially increased the fracture stress of gels containing ≤50 mmol/dm 3 NaCl but slightly decreased the fracture modulus at concentrations >100 mmol/dm 3 . The fracture strain and water holding capacity were decreased by lecithin addition across the NaCl concentration range examined (30–500 mmol/dm 3 ). These results suggest that the gel network type and/or the dispersed state of lecithin changing with NaCl concentration in the system is responsible for the mechanism of lecithin–whey protein interactions. Lecithin can play a beneficial role in promoting gel strength but there is an optimal level which is strongly related to the amount of NaCl in the system.
Stability conditions for a two-priority packet broadcast channel

Sufficient conditions for the stability of the two-priority, virtual time CSMA packet broadcast channel are developed. The results are in the form of inequalities which define stable operating regions for the channel in terms of its parameters. In particular, for given packet arrival rates, packet lengths, and a collision detection time for the two traffic types, one is able to determine retransmission controls and virtual time clock rates which stabilize the channel.
Melt spinning of nylon 6: Structure development and mechanical properties of as-spun filaments

The structure of melt-spun nylon 6 filaments was studied using on-line x-ray diffraction and birefringence measurements. Measurements were also made on as-spun and treated filaments. On-line wide-angle x-ray scattering measurements indicated that crystallization did not occur on the nylon 6 spinline at spinning rates up to 1000 m/min when spinning was done into either ambient air of 60% relative humidity or into wet saturated air. The filaments did crystalline gradually on the bobbin to a paracrystalline pseudohexagonal (γ) form. The rate of crystallization was dependent on the molecular orientation developed in the spun filaments. Crystalline orientation factors based on hexagonal symmetry were computed as a function of take-up velocity for fibers which were conditioned 24 hr in air at 65% relative humidity. Annealing in air or treatment in water or 20% formic acid solution causes a transformation from the pseudohexagonal form to the α monoclinic form. The tangent modulus of elasticity and tensile strength of spun and conditioned filaments increase with increasing take-up velocity and spinline stress, while elongation to break decreases with these variables.
Predicting Drug-Induced QT Prolongation Effects Using Multi-View Learning

Drug-induced QT prolongation is a major life-threatening adverse drug effect. It is crucial to predict the QT prolongation effect as early as possible in drug development, however, data on drugs that induce QT prolongation are very limited and noisy. Multi-view learning (MVL) has been applied to many challenging machine learning and data mining problems, especially when complex data from diverse domains are involved and only limited labeled examples are available. Unlike existing MVL methods that use l2-norm co-regularization to obtain a smooth objective function, in this paper we proposed an l1-norm co-regularized MVL algorithm for predicting drug-induced QT prolongation effect and reformulate the l1-norm co-regularized objective function for deriving its gradient in the analytic form, and we can optimize the mapping functions on all views simultaneously and achieve 3-4 times higher computational efficiency, while previous l2-norm co-regularized MVL methods use alternate optimization that alternately optimizes one view with the other views fixed until convergence. l1-norm co-regularization enforces sparsity in the learned mapping functions and hence the results are expected to be more interpretable. Comprehensive experimental comparisons between our proposed method and previous MVL and single-view learning methods demonstrate that our method significantly outperforms those baseline methods more efficiently.
Repressed memory lawsuits: Potential verdict predictors

This research examined the relationship between verdict and juror sex, ethnicity, religiosity and authoritarianism, and case type in lawsuits involving repressed memories of childhood sexual abuse. Subjects (N = 251) read excerpts from one of two hypothetical lawsuits (one involving claims of incest or one involving accusations of satanic ritual abuse; SRA), rendered an individual verdict, and responded to demographic questionnaires and measures of religiosity and authoritarianism. It was predicted that jurors who were female, highly religious, high authoritarian, or Mexican-American would be most likely to sympathize with the plaintiff, and that the SRA version would be less successful. Logit analysis yielded a main effect of sex on verdict and an interaction between sex, authoritarianism, and religiosity on verdict, both findings consistent with predictions. Hypotheses predicting main effects of ethnicity on verdict and case type on verdict did not find statistical support. Language: en
Catecholamines and self-stimulation behavior: effects on brain levels after stimulation, and pretreatment with dl-α-methyl-p-tyrosine

Abstract The present results confirm earlier findings that forcedstimulation of the hypothalamic reward region in non-α-MPT-treated animals does not appreciably lower hypothalamic norepinephrine yet elicits an adrenal stress response. In experiments in which norepinephrine synthesis was blocked, the results suggest that hypothalamic norepinephrine turnover is increased in animals in which non-contingent stimulation is applied to the hypothalamic reinforcing region. Although stimulation at rewarding sites was not clearly differentialted from stimulation at non-rewarding sites, there was a tendency for norepinephrine concentrationa to be lower in the former both after α-MPT alone and especially after combined drug treatment and forced stimulation. The variance in both behavioral and biochemical responses in the latter condition were attributed to activation of adjacent, but functionally distinct, hypothalamic neurons in the region of probe implantation. Finally, the technique of prior blockade of synthesis appears potentially useful in permitting detection of small absolute changes in concentration by magnifying the relative change. However, the results also indicate that electrode placement and size, together with stimulus parameters, may be extremely important in attempting to relate monoamine changes during forced stimulation with activation of the reward system.
Some solutions, some problems, and some questions

This is a slightly expanded written version of a plenary lecture given at the 20th IEEE Conference on Decision and Control, December 1981, San Diego, CA. This talk is intended to help spark discussion among researchers in decision, control and estimation about the status of research in the field and of promising new directions for research. One such direction, model-based signal processing, is treated in some depth together with an example, an object detection and estimation approach to tomographic reconstruction. Several additional topics are treated through the posing of questions which hopefully will provoke responses.
Detection of shielded nuclear material in a cargo container

Abstract The Idaho National Laboratory, along with Los Alamos National Laboratory and the Idaho State University's Idaho Accelerator Center, are developing electron accelerator-based, photonuclear inspection technologies for the detection of shielded nuclear material within air-, rail-, and especially, maritime-cargo transportation containers. This paper describes a developing prototypical cargo container inspection system utilizing the Pulsed Photonuclear Assessment (PPA) technology, incorporates interchangeable, well-defined, contraband shielding structures (i.e., “calibration” pallets) providing realistic detection data for induced radiation signatures from smuggled nuclear material, and provides various shielded nuclear material detection results. Using a 4.8-kg quantity of depleted uranium, neutron and gamma-ray detection responses are presented for well-defined shielded and unshielded configurations evaluated in a selected cargo container inspection configuration.
Structural insight into mechanism and diverse substrate selection strategy of L-ribulokinase.

The araBAD operon encodes three different enzymes required for catabolism of L-arabinose, which is one of the most abundant monosaccharides in nature. L-ribulokinase, encoded by the araB gene, catalyzes conversion of L-ribulose to L-ribulose-5-phosphate, the second step in the catabolic pathway. Unlike other kinases, ribulokinase exhibits diversity in substrate selectivity and catalyzes phosphorylation of all four 2-ketopentose sugars with comparable kcat values. To understand ribulokinase recognition and phosphorylation of a diverse set of substrates, we have determined the X-ray structure of ribulokinase from Bacillus halodurans bound to L-ribulose and investigated its substrate and ATP co-factor binding properties. The polypeptide chain is folded into two domains, one small and the other large, with a deep cleft in between. By analogy with related sugar kinases, we identified 447GGLPQK452 as the ATP-binding motif within the smaller domain. L-ribulose binds in the cleft between the two domains via hydrogen bonds with the side chains of highly conserved Trp126, Lys208, Asp274, and Glu329 and the main chain nitrogen of Ala96. The interaction of L-ribulokinase with L-ribulose reveals versatile structural features that help explain recognition of various 2-ketopentose substrates and competitive inhibition by L-erythrulose. Comparison of our structure to that of the structures of other sugar kinases revealed conformational variations that suggest domain–domain closure movements are responsible for establishing the observed active site environment. Proteins 2012; © 2011 Wiley Periodicals, Inc.