cssi/SciSciGPT-SciSciNet huggingface dataset:
The effects of nitrogen mustards on the proliferative and Ig synthetic response of human peripheral blood lymphocytes.

Abstract Maximal inhibition of pokeweed mitogen-stimulated Ig production and [ 3 H]thymidine incorporation was shown to occur when unfractionated human peripheral blood mononuclear cells were cultured with concentrations of the nitrogen mustards melphalan, mechlorethamine or chlorambucil in the 20–100-μM range, whereas concentrations of microsome-activated cyclophosphamide (A-Cy) in the 2-mM range were required for equivalent inhibition. Around 400 μM A-Cy, IgM secretion was not inhibited, but secretion of IgA and IgG was. The [ 3 H]thymidine incorporation of enriched populations of both large and small B and T cells all showed about 20–50-fold greater sensitivity to melphalan than to A-Cy, despite a difference of only 6-fold in alkylating activity between these drugs. Large (250 μm 3 ) B and T cells were only marginally more sensitive to melphalan and A-Cy than small (210 μm 3 ) T and B cells. Kinetic studies showed that IgG and IgA secreted by day 7 could be maximally inhibited by melphalan added as late as day 3, and IgM synthesis as late as day 2. In contrast, inhibition of Ig production by A-Cy steadily declined after the first day, especially IgM, which was no longer inhibitable by A-Cy on day 3. Inhibition of cumulative Ig production did not occur when A-Cy or melphalan was added on day 5 or later. Cell recombination experiments performed with drug pulsed and untreated monocytes plus B cells and irradiated T cells showed that inhibition of [ 3 H]thymidine of Ig production was most striking when monocytes + B cells (rather than T cells) were exposed to melphalan in the first 16 h. When A-Cy was used in the first 16 h, inhibition of Ig production was partial and inconsistent, and inhibition of monocytes + B cell or T cell [ 3 H]thymidine incorporation was not evident. We conclude that the nitrogen mustards melphalan and A-Cy can inhibit pokeweed mitogen-stimulated DNA synthesis by human T or B cells and Ig production in vitro, but that their mechanisms of action differ.
Mechanistic studies of the reaction of oxetanes with methylthiotrimethylsilane

Abstract The zinc chloride-catalyzed reaction of oxetane with methylthiotrimethylsilane yields (3-chloropropoxy)trimethylsilane (minor) and (3-methylthiopropoxy)trimethylsilane (major). Similar results have been obtained with 2-methyloxetane, 3,3-dimethyloxetane and 2,2-dimethyloxetane. These results have been interpreted in terms of competing S N 1 and S N 2 processes.
Numerical determination of axisymmetric toroidal magnetohydrodynamic equilibria

Numerical schemes for the determination of stationary axisymmetric toroidal equilibria appropriate for modeling real experimental devices are given. Iterative schemes are used to solve the elliptic nonlinear partial differential equation for the poloidal flux function psi. The principal emphasis is on solving the free boundary (plasma-vacuum interface) equilibrium problem where external current-carrying toroidal coils support the plasma column, but fixed boundary (e.g., conducting shell) cases are also included. The toroidal current distribution is given by specifying the pressure and either the poloidal current or the safety factor profiles as functions of psi. Examples of the application of the codes to tokamak design at PPPL are given.
Adherence to Communal Norms: What It Means, When It Occurs, and Some Thoughts on How It Develops.

Communal norms, which emerge gradually across childhood, are a product of social exchanges characteristic of relationships with family members and friends.
Update on the use of conventional disease-modifying antirheumatic drugs in the management of rheumatoid arthritis.

Purpose of review The present review will focus on the role of conventional disease-modifying antirheumatic drugs (DMARDs) in the current management of rheumatoid arthritis (RA). Recent findings Over the past several decades, the treatment of RA has been revolutionized, not only by the development of highly effective biologic agents but also through a better understanding of the critical importance of early DMARD treatment with a goal of remission or low disease activity and of how to effectively and safely use conventional DMARDs, either as monotherapy or in combinations. Summary Conventional DMARDs have proven efficacy in the management of RA and remain a valid treatment option, either in monotherapy or as a component of combination regimens. Although conventional DMARDs have associated toxicities, these are distinct from those of the biologic DMARDs. In addition, conventional DMARDs are much less expensive than biologic DMARDs, and in many cases can be successful in achieving similar control of disease activity. The goal for all patients should be achieving remission, or at least low disease activity, with the most cost-effective therapy possible.
Cyanobacterial Aldehyde Deformylase Oxygenation of Aldehydes Yields n – 1 Aldehydes and Alcohols in Addition to Alkanes

Aldehyde-deformylating oxygenase (ADO) catalyzes O2-dependent release of the terminal carbon of a biological substrate, octadecanal, to yield formate and heptadecane in a reaction that requires external reducing equivalents. We show here that ADO also catalyzes incorporation of an oxygen atom from O2 into the alkane product to yield alcohol and aldehyde products. Oxygenation of the alkane product is much more pronounced with C9-10 aldehyde substrates, so that use of nonanal as the substrate yields similar amounts of octane, octanal, and octanol products. When using doubly-labeled [1,2-13C]-octanal as the substrate, the heptane, heptanal and heptanol products each contained a single 13C-label in the C-1 carbons atoms. The only one-carbon product identified was formate. [18O]-O2 incorporation studies demonstrated formation of [18O]-alcohol product, but rapid solvent exchange prevented similar determination for the aldehyde product. Addition of [1-13C]-nonanol with decanal as the substrate at the outset of the reaction resulted in formation of [1-13C]-nonanal. No 13C-product was formed in the absence of decanal. ADO contains an oxygen-bridged dinuclear iron cluster. The observation of alcohol and aldehyde products derived from the initially formed alkane product suggests a reactive species similar to that formed by methane monooxygenase (MMO) and other members of the bacterial multicomponent monooxygenase family. Accordingly, characterization by EPR and Mossbauer spectroscopies shows that the electronic structure of the ADO cluster is similar, but not identical, to that of MMO hydroxylase component. In particular, the two irons of ADO reside in nearly identical environments in both the oxidized and fully reduced states, whereas those of MMOH show distinct differences. These favorable characteristics of the iron sites allow a comprehensive determination of the spin Hamiltonian parameters describing the electronic state of the diferrous cluster for the first time for any biological system. The nature of the diiron cluster and the newly recognized products from ADO catalysis hold implications for the mechanism of C-C bond cleavage.
Clinical pharmacokinetics of the PDT photosensitizers porfimer sodium (Photofrin), 2-[1-hexyloxyethyl]-2-devinyl pyropheophorbide-a (Photochlor) and 5-ALA-induced protoporphyrin IX.

Background and Objectives Photodynamic therapy (PDT) uses a photosensitizer activated by light, in an oxygen-rich environment, to destroy malignant tumors. Clinical trials of PDT at Roswell Park Cancer Institute (RPCI) use the photosensitizers Photofrin, Photochlor, and 5-ALA-induced protoporphyrin IX (PpIX). In some studies the concentrations of photosensitizer in blood, and occasionally in tumor tissue, were obtained. Pharmacokinetic (PK) data from these individual studies were pooled and analyzed. This is the first published review to compare head-to-head the PK of Photofrin and Photochlor. Study Design/Materials and Methods Blood and tissue specimens were obtained from patients undergoing PDT at RPCI. Concentrations of Photofrin, Photochlor, and PpIX were measured using fluorescence analysis. A non-linear mixed effects modeling approach was used to analyze the PK data for Photochlor (up to 4 days post-infusion; two-compartment model) and a simpler multipatient-data-pooling approach was used to model PK data for both Photofrin and Photochlor (at least 150 days post-infusion; three-compartment models). Physiological parameters were standardized to correspond to a standard (70 kg; 1.818 m2 surface area) man to facilitate comparisons between Photofrin and Photochlor. Results Serum concentration-time profiles obtained for Photofrin and Photochlor showed long circulating half-lives, where both sensitizers could be found more than 3 months after intravenous infusion; however, estimated plasma clearances (standard man) were markedly smaller for Photofrin (25.8 ml/hour) than for Photochlor (84.2 ml/hour). Volumes of distribution of the central compartment (standard man) for both Photofrin and Photochlor were about the size (3.14 L, 4.29 L, respectively) of plasma volume, implying that both photosensitizers are almost 100% bound to serum components. Circulating levels of PpIX were generally quite low, falling below the level of instrument sensitivity within a few days after topical application of 5-ALA. Conclusion We have modeled the PK of Photochlor and Photofrin. PK parameter estimates may, in part, explain the relatively long skin photosensitivity attributed to Photofrin but not Photochlor. Due to the potential impact and limited experimental PK data in the PDT field further clinical studies of photosensitizer kinetics in tumor and normal tissues are warranted. Lasers Surg. Med. © 2006 Wiley-Liss, Inc.
Optimization of conditions for the polymerase chain reaction amplification of DNA from culturable and nonculturable cells of Vibrio vulnificus

Abstract A series of 16 buffers, differing in pH and MgCl 2 concentration, were used to optimize the polymerase chain reaction (PCR) amplification of a 388 bp region of the hemolysin / cytolysin gene from cells of Vibrio vulnificus present in both the culturable and nonculturable states. Both the opaque and translucent morphotypes were examined. Using whole cell lysates, we were able to obtain amplification of DNA from as few as 28.5 cells present in the viable but nonculturable state. With one exception, all buffers that produced amplification using culturable cells also produced amplification using nonculturable cells. However, regardless of the buffer employed, 100 times more nonculturable cells than culturable cells were required to obtain a PCR product. Our data suggest that caution should be exercised when employing PCR optimized against culturable cells when this method is employed for the detection of nonculturable cells.
Mechanism for reliable low latency communications in Computing Clusters

Recent increases in the demands for computing power have given rise to the prevalence of distributed computing. Computationally complex problems are broken down into smaller chunks and are distributed to computing nodes that perform the computation simultaneously. The nodes may exchange information as peers and their combined result is the final outcome of the computation. Multiple computers need a mechanism to communicate and exchange information in order to harness collective computing power. Traditionally, the Transmission Control Protocol (TCP) has been used to exchange information between computers. However, additional overhead, generally associated with TCP has been considered as a serious drawback for any rapid data exchange. The User Datagram Protocol (UDP) alleviates the overheads of TCP but provides no reliability for the data transfer. In this paper, we introduce an enhanced UDP mechanism to exchange data of limited size reliably and without any associated overhead of TCP.
Bäcklund transformations and the inverse method

Abstract For several partial differential equations with important physical applications we show an exact correspondence between the equations of the Backlund transformation and the linear equations of the inverse scattering method.
PURIFICATION OF CHOLINE ACETYLTRANSFERASE FROM DROSOPHILA MELANOGASTER

Abstract— Purification of choline acetyltransferase (ChAc) from heads of Drosophila melanogaster, the richest known source of ChAc, has been accomplished. The stability of the enzyme was preserved by working with a concentration of protein above 0.1 mg/ml. The purification was carried out with ammonium sulfate fractionation and column chromatography on QAE-Sephadex, CoA-Sepharose, G-200 Sephadex, and PCMB-Sepharose. In a procedure using 100 g of Drosophila heads, the specific activity of the crude homogenate was 0.028 μmol/min/mg protein and that of the final product was 43 μmol/min/mg protein, representing a 1500 fold purification. A single protein band, containing all of the ChAc activity, was seen by polyacrylamide gel electrophoresis. A sharp pH optimum at 7.2 was observed. Apparent Km's for acetyl CoA and choline were 90 μM and 47 μM, respectively. The molecular weight was determined to be 69,000. Isoelectric focusing of extracts of Drosophila heads showed only one peak of choline acetyltransferase activity with an apparent pi of 5.1.
WOMEN'S RIGHTS BEFORE THE FEDERAL DISTRICT COURTS, 1971-1977:

This study analyzes opinions published by federal district judges in women's rights and racial minority discrimination cases in the period 1971-1977. Our analysis revealed that the petitioner in women's rights cases was only slightly more likely to be victorious than litigants from other disadvantaged groups. Using a regional variable, we found no significant differences between northern and southern judges deciding women's rights cases. However, the judge's political party identification proved to be an important variable, and a meaningful split was found to exist between Democratic and Republican jurists in women's rights decisions.
Impending Paradoxical Embolus

The diagnosis of paradoxical embolization typically requires evidence of acute systemic arterial occlusion, systemic venous thrombosis, and a pathway for the thromboembolus to bypass the pulmonary vasculature. However, even when all of these findings are present, they cumulatively represent only a “smoking gun” from which a diagnosis is inferred. It is rare that one captures the actual process of paradoxical embolization “red-handed.” These transthoracic and transesophageal echocardiographic images demonstrate a thrombus …
Relational, Social, and Overt Aggression among Aggressive and Nonaggressive Female Adolescents

In this study, researchers wished to further study the differentiation among forms of aggression in a diverse sample of adolescent females. Specifically, the self-reported use of relational, social, and direct verbal and physical aggression was measured in Caucasian and non-Caucasian typically developing versus overtly aggressive adolescent females. No statistically significant differences were found between typically developing and overtly aggressive adolescent female samples in the use of social or relational aggression; however, overtly aggressive adolescents reported using direct verbal or physical aggression significantly more than typically developing adolescents. Caucasian adolescents reported using significantly more relationally aggressive behaviors than non-Caucasian adolescents. No statistically significant differences were found in socially aggressive behaviors between Caucasian and non-Caucasian adolescent female samples. Implications for these findings are discussed.
Chief academic officers’ perceptions of the relationship between faculty research and undergraduate teaching

The purpose of this article is to examine chief academic officers’ perceptions of the relationship between faculty research and faculty undergraduate teaching effectiveness. We contend that chief academic officers are instrumental in establishing institutional definitions of scholarship and in creating faculty reward patterns. Data were gathered through a mail questionnaire sent to 300 chief academic officers. A stratified random sampling technique was used to establish a representative sample. The data indicate that chief academic officers often use a conventional standard—a research‐publication standard—to measure the effectiveness of teaching. We call this process regressive determination and suggest that it occurs when there is a need to evaluate others in the presence of developing or conflicting norms for scholarly assessment. Implications for the definitional processes of scholarship and faculty reward are discussed.
The Systematic Practice of Preventive Cardiology

The Preventive Strategy Delivery of preventive services differs little from that of therapeutic services. In traditional practice we obtain the medical history, carry out the physical examination, order and interpret the laboratory work, formulate diagnoses and prescribe therapy. The ap preach to preventive cardiology is similar. Begin with a traditional work-up. This is impressive to the patient and revealing to you. It gives credibility to your summation of the evidence for risk and to your preventive recommendations. It also sets a personal tone of caring for your patient. It sharply focuses your attention on the patient as an individual. Summarize the clinical and laboratory findings. Link them to a general class of risk sufficiently real to command attention but not exaggerated for its accuracy of individual prediction. Specific recommendations for new behaviors reduce the fear and rejection that can be associated with labeling as “high risk.” Link the risk class to the patient’s personal behavior and genetic legacy, thus balancing the modifiable and unmodifiable factors of risk. Review smoking, eating, physical activity and weight change patterns in daily living. Then try to tie the risk and personal habits to family and social behaviors, giving the patient insights into the nature and causes of excess risk. Point out situations in the home and worksite that influence the eating activity and smoking patterns of the patient’s spouse, children and colleagues. Finding a relatively low risk status provides the occasion for congratulations, but also allows you to indicate the influence of the patient’s behavior on others, i.e., the development of risk in family and friends. A11 in the family need to
UV Enhancement of Surface Catalytic Polymerization of Ethylene

The polymerization of ethylene on surfaces sequentially dosed with TiC1 4 and trimethylaluminum was studied by Fourier transform infrared spectroscopy. The polymer film was observed in situ as a function of time and under the influence of 254-nm cw radiation. The rate of polymerization and the saturation thickness of the polyethylene are strongly dependent on the order of dosing and the partial pressures of the reactants that form the catalyst. UV enhancement of polymerization was demonstrated to occur through two separate photochemical channels: gas-phase photolysis of the reactants and solid-phase chemical transformation of a noncatalytic thin film.
Transcriptional Mediators Kto and Skd Are Involved in the Regulation of the IMD Pathway and Anti-Plasmodium Defense in Anopheles gambiae

The malarial parasite Plasmodium must complete a complex lifecycle in its Anopheles mosquito host, the main vector for Plasmodium. The mosquito resists infection with the human malarial parasite P. falciparum by engaging the NF-κB immune signaling pathway, IMD. Here we show that the conserved transcriptional mediators Kto and Skd are involved in the regulation of the mosquito IMD pathway. RNAi-mediated depletion of Kto and Skd in the Anopheles gambiae cell line L5-3 resulted in a decrease in the transcript abundance of Cec1, which is controlled by the IMD pathway. Silencing the two genes also resulted in an increased susceptibility of the mosquito to bacterial and Plasmodium falciparum infection, but not to infection with the rodent malaria parasite P. berghei. We also showed that Kto and Skd are not transcriptional co-activators of Rel2 or other key factors of the IMD pathway; however, they participate in the regulation of the IMD pathway, which is crucial for the mosquito’s defense against P. falciparum.
Experimental Study of Polymer Drag Reduction in a Turbulent Channel Flow

The effect of polymer injection on the turbulence characteristics of a fully developed turbulent water channel flow was studied. The main focus of this study was to assess the influence of the polymer solution injection concentration and consequent mixing. This study was conducted by measuring the turbulence characteristics of two fully developed turbulent channel flows for a Reynolds number of 5×104 , with different injection concentrations of the same polymer solution but with the same homogeneous concentration at the test section. These measurements were complemented by visualizations of the flow, which revealed the presence of supra-molecular polymer structures. The development of such structures seems to enhance the drag reducing abilities of the polymer solution.Copyright © 2003 by ASME
A radial pattern of sea-floor deformation in the southwestern Caribbean Sea

Discontinuous bathymetric lineaments and faults are disposed radially and concentrically about a cluster of seamounts in the southwestern Caribbean Sea. The lineament system extends at least 350 km from the least-squares center of strike intersections and includes more than 350,000 km2 of sea floor on the Nicaraguan Rise and in the Colombian Basin. This center, the probable deformation center, lies near San Andres Island at lat 12.6°N, long 81.6°W. The central position of the seamount cluster suggests that volcanism accompanied the deformation. The age and duration of the event are unknown.
Pentacovalent phosphorus-containing model of a P(V) cyclic nucleotide intermediate. Non-chair conformation of the phosphorus-containing ring

Abstract A cyclic nucleotide model system ( 3 ) for P(V) cAMP-substrate or cAMP-enzyme adducts is shown by 1 H NMR analysis to be totally in a twist conformation ( 3b ).
Evidence for the existence of the colicinogenic factors E2 and E3 as supercoiled circular DNA-protein relaxation complexes

Abstract Colicinogenic factor E 1 previously has been isolated as a supercoiled circular DNA-protein complex that undergoes a conversion to the relaxed, or open circular, state when the complex is treated with certain proteases, strong ionic detergents, or alkali. In this study, data is presented demonstrating the existence of similar relaxation complexes for the bacterial colicinogenic factors E 2 and E 3 of Escherichia coli .
Learning about methodology development for integrated soil fertility management

Abstract This paper describes the development of a participatory learning and action research approach for integrated soil fertility management. The methodology research was conducted in three sites within the context of research and development services in sub-Saharan Africa. The key elements of the approach are described and factors determining the methodology development process are analysed. Farmer learning takes place at the individual and communicative level. Individual learning is based on farm mapping and farmer experimentation, while communicative learning takes place during the four distinct phases of the approach when farmers exchange insights and interact with the field team. The paper further discusses major learning points in facilitation of farmer learning and analyses major implications and issues in extending the participatory learning and action research approach.
Cactus Alkaloids XXXIII: β-Phenethylamines from the Guatemalan Cactus Pilosocereus maxonii

Abstract TLC analysis of extracts of Pilosocereus maxonii (Rose) Byles and Rowley detected six identifiable alkaloids. Preparative TLC aided in the crystallization of the hydrochlorides of N -methyl-3,4-di-methoxyphenethylamine, N -methyl-3-methoxytyramine, and N,N- dimethyl-3-methoxytyramine. Traces of 3,4-dimethoxyphenethylamine (TLC and mass spectrometry), tyramine (TLC), and N -methyltyramine (TLC) were identified. While all of these compounds were isolated and/or detected previously in other cactus species, this study is the first reported crystallization of JV-methyl- and N , N -dimethyl-3-methoxytyramine from a natural source.
Immunoglobulin and specific antibody synthesis during the first weeks of life of premature infants.

The hypothesis that antigenic exposure following birth causes the acceleration of immunoglobulin synthesis was evaluated by relating synthesis of immunoglobulin in premature infants (1,500 to 2,250 grams) to birth and not to gestational age and by demonstrating specific antibody production to a cow's milk protein during the first 2 weeks of life. During the first 21 days of life the onset of IgA synthesis and the changes in IgA and IgM serum concentrations were similar in 1,500 to 1,899 grams, 1,900 to 2,250 grams, and full-term infants. A slight increase in IgG cord serum concentration was associated with increasing birth weight. The subsequent metabolism of IgG was similar in the 3 groups. In contrast to an undetectable immune response to bovine serum albumin (BSA) in infants not fed the antigen, 63 per cent of the infants fed BSA were immunized against this antigen. Anti-BSA was detected in IgG as well as in IgM immunoglobulins, demonstrating the capacity of these infants to make specific IgG antibodies. Qualitatively the anti-BSA was shown to be a poor precipitating antibody.
Asymmetric Synthesis of α-Keto Esters via Cu(II)-Catalyzed Aerobic Deacylation of Acetoacetate Alkylation Products: An Unusually Simple Synthetic Equivalent to the Glyoxylate Anion Synthon

A simple and efficient method for the preparation of β-stereogenic α-keto esters is described using a copper(II)-catalyzed aerobic deacylation of substituted acetoacetate esters. The substrates for the title process arise from catalytic, enantioselective conjugate additions and alkylation reactions of acetoacetate esters. The mild conditions do not induce racemization of the incipient enolizable α-keto ester. The reaction is tolerant of esters, certain ketones, ketals, and nitro groups and utilizes inexpensive, readily available materials.
Characteristics and mechanism of threshold switching

Abstract The paper gives an account of two series of experiments on threshold switches based on chalcogenide glass films, one concerned with the nature of the on -state, and one concerned with the effect of crystalline semiconductors as contacting materials. The results, including the demonstration of a new “blocked- on -state”, consolidate electronic (non-thermal) interpretations of threshold switching. Asymmetric switches involving one graphite and one Ge contact exhibit asymmetric switching, the direction of the asymmetry being reversed for n-type and p-type Ge. Such switches are also light sensitive.
Toward a women-centered health care system: women's experiences, women's voices, women's needs.

In this report we describe the results from 19 focus groups of nearly 250 women held in 1993 and 1994, in which diverse groups of women were asked to respond to a model health care delivery system. This project, sponsored by the Women's Health Advisory Committee of the San Francisco Department of Public Health, solicited focused input from diverse groups of women as they reviewed the draft of an “ideal” women's health care service model. Women's responses to an ideal system revealed some of the problems inherent with the current “nonsystem” of health care delivery. These responses were categorized into general themes and are presented here to demonstrate the range of women's experiences with their current health care, from their perspective and in their voices.
Integrins and cancer: regulators of cancer stemness, metastasis, and drug resistance

Interactions between cancer cells and their surroundings can trigger essential signaling cues that determine cell fate and influence the evolution of the malignant phenotype. As the primary receptors involved in cell-matrix adhesion, integrins present on the surface of tumor and stromal cells have a profound impact on the ability to survive in specific locations, but in some cases, these receptors can also function in the absence of ligand binding to promote stemness and survival in the presence of environmental and therapeutic stresses. Understanding how integrin expression and function is regulated in this context will enable the development of new therapeutic approaches to sensitize tumors to therapy and suppress their metastatic phenotype.
Mimosine Attenuates Serine Hydroxymethyltransferase Transcription by Chelating Zinc IMPLICATIONS FOR INHIBITION OF DNA REPLICATION

Abstract l-Mimosine is a naturally occurring plant amino acid and iron chelator that arrests the cell cycle in the late G1 phase, although its mechanism of action is not known. Some studies indicate that mimosine prevents the initiation of DNA replication, whereas other studies indicate that mimosine disrupts elongation of the replication fork by impairing deoxyribonucleotide synthesis by inhibiting the activity of the iron-dependent enzyme ribonucleotide reductase and the transcription of the cytoplasmic serine hydroxymethyltransferase gene (SHMT1). In this study, the mechanism for mimosine-induced inhibition of SHMT1 transcription was elucidated. A mimosine-responsive transcriptional element was localized within the first 50 base pairs of the human SHMT1 promoter by deletion analyses and gel mobility shift assays. The 50-base-pair sequence contains a consensus zinc-sensing metal regulatory element (MRE) at position -44 to -38, and mutation of the MRE attenuated mimosine-induced transcription repression. Mimosine treatment eliminated MRE- and Sp1-binding activity in nuclear extracts from MCF-7 cells but not in nuclear extracts from a mimosine-resistant cell line, MCF-7/2a. MCF-7 cells cultured in zinc-depleted medium for more than 16 days were viable and lacked cytoplasmic serine hydroxymethyltransferase protein, confirming that mimosine inhibits SHMT1 transcription by chelating zinc. The disruption of DNA-protein interactions by zinc chelation provides a general mechanism for the inhibitory effects of mimosine on nuclear processes, including replication and transcription. Furthermore, this study establishes that SHMT1 is a zinc-inducible gene, which provides the first mechanism for the regulation of folate-mediated one-carbon metabolism by zinc.
Effects of early discordant binocular vision on the postnatal development of parvocellular neurons in the monkey lateral geniculate nucleus

The effects of early discordant binocular vision on the fidelity of signal transfer in parvocellular neurons of the lateral geniculate nucleus (LGN) were investigated in rhesus monkeys reared with ocular misalignment (strabismus). Unilateral convergent strabismus (esotropia) was surgically induced in four infant monkeys between 20 and 30 days of age and the animals were reared in a normally lighted environment until they were adults. Extracellular microelectrode recordings were made in individual units of anesthetized and paralyzed subjects. Drifting sinusoidal gratings were used as visual stimuli. Within-unit comparisons of the LGN action potentials (LGN output) and S potentials (retinal input) were performed to determine the accuracy of signal transfer in the LGN. Contrary to the previous findings in the cat LGN, the signal transfer characteristics of parvocellular units in strabismic monkeys were normal regardless of stimulus spatial frequency, temporal frequency, or contrast. The differences between cats and monkeys in LGN circuitry and the relative maturity of the central visual pathway at the onset of strabismus may have contributed to the apparent species differences in the functional development of the LGN.
A Note on Systems Theory and the Idea of Interface

The article presents a letter to the editor in response to a March 1967 article by Daniel A. Wren regarding interfacing in organization theory.
Epidemiology and outcome of postural headache management in spontaneous intracranial hypotension

Background and Objectives: Spontaneous intracranial hypotension is a postural headache syndrome unrelated to dural puncture. Due to the apparent failure of epidural blood patch to relieve headache in spontaneous intracranial hypotension, we investigated the epidemiologic features and treatment outcomes of this condition. Methods: The clinical findings and management of 22 cases (21 published + 1 reported) of spontaneous intracranial hypotension were analyzed retrospectively. The study population was stratified by age and sex; continuous variables were compared for differences by t-tests; categorical variables were compared by Fisher exact tests. Significant differences were identified by P values of .05 or less. Results: The mean age of the study population was 43 [plusmn] 16 years, with a female:male ratio of 3.4:1.0. Females with spontaneous intracranial hypotension were younger (P = .050) than males. Men presented with tinnitus (P = .021) and visual field defects (P = .009) more often than women. Meningeal enhancement on contrast magnetic resonance imaging was the most consistent radiographic finding. Radionuclide cisternography showed thoracolumbar dural leaks in 7 of 9 patients. Cerebrospinal fluid opening pressure was low in all patients (33.13 [plusmn] 31.02 mm H2O). Epidural blood patch was performed in 8 patients, repeated in 3 patients, failed in 3 patients, and offered only transient improvement in 5 patients. Conclusions: Spontaneous intracranial hypotension was more common in women than men, was not uniformly responsive to epidural blood patch, and had significant comorbidities. The management of postural headache in spontaneous intracranial hypotension by other techniques to restore cerebrospinal fluid dynamics and prevent its leakage should be investigated. Reg Anesth Pain Med 2001;26:582-587.
Pharmacokinetic and Pharmacodynamic Properties of Meropenem

Pharmacokinetic and pharmacodynamic profiles of antibiotics are important in determining effective dosing regimens. Although minimum inhibitory concentration (MIC) data reflect microbial susceptibility to an antibiotic, they do not provide dosing information. The integration of pharmacokinetic and microbiological data, however, can be used to design rational dosing strategies. Meropenem is a broad-spectrum b-lactam antibiotic that penetrates most body fluids and tissues rapidly after intravenous administration. Meropenem undergoes primarily renal elimination; therefore, dosage adjustment is required for patients with renal impairment. Meropenem is indicated for the treatment of complicated skin and skin-structure infections, complicated intra-abdominal infections, and bacterial meningitis. Meropenem has time-dependent bactericidal activity; thus, the percentage of time that free-drug concentrations are higher than the MIC ( ) best %T 1 MIC characterizes the drug’s pharmacodynamic profile (bactericidal target of ). Pharmacodynamic ∼ 40%T 1 MIC modeling can identify regimens with the greatest probability of attaining this target, and probabilities can be compared with clinical and microbiological responses in patients.
Fault Tolerance for Spacecraft Attitude Management

We present an autonomy architecture called Fault Tolerant Remote Agent that integrates symbolic reasoning from AI planning/scheduling with physics-based fault-tolerant control. Application to spacecraft attitude management in the presence of diverse failure classes is studied. We first review fault tolerance in AI and control-theoretic contexts and introduce an architecture in which the capabilities of each can be integrated into a more comprehensive fault management framework. We then present fault identification and reconfiguration algorithms for a spacecraft attitude control case study. Simulation results demonstrate good recovery by the spacecraft for situations in which controllability is not lost. These simulations also illustrate how logic-based and physics-based algorithms cooperatively achieve a more comprehensive fault management capability than would be possible with either algorithm class alone.
Time dependent spine stability: The wise old man and the six blind elephants

Spine stability of the behaving human in health or disorder is a complex, multi-factorial and time variable index. The major components of stability are the properties of the external load, passive viscoelastic tissues (ligaments, discs, facet capsules and dorso-lumbar fascia) combined with the properties of the active tissues (muscles and their sensory-motor control, co-activation and associated intra-abdominal pressure) as well as the pro-inflammatory status of the tissues. Each of the many components' contribution is time variable with dependence on the dose-duration of the work stimulus and the associated rest. Interaction of many variables is also dominant. A call is issued to focus research efforts on the development of a multi-factorial description of spine stability while representing the contribution of all relevant components as time variable functions. An example is provided, using models of four components described as functions of time derived from real data obtained simultaneously from the in-vivo feline. The example elucidates the potential errors made when using single components to assess stability and the insight gained when stability is introduced as a time dependent index. It is expected that such time variable stability assessment will provide uniform and insightful estimation that will have valuable applications in occupational, sports and rehabilitation fields as well as the leisure lifestyles required for maintaining a healthy spine.
Accurate heats of formation of the "Arduengo-type" carbene and various adducts including H2 from ab initio molecular orbital theory.

The heats of formation of saturated and unsaturated diaminocarbenes (imadazol(in)-2-ylidenes) have been calculated by using high levels of ab initio electronic structure theory. The calculations were done at the coupled cluster level through noniterative triple excitations with augmented correlation consistent basis sets up through quadruple. In addition, four other corrections were applied to the frozen core atomization energies: (1) a zero point vibrational correction; (2) a core/valence correlation correction; (3) a scalar relativistic correction; (4) a first-order atomic spin−orbit correction. The value of ΔHf 298 for the unsaturated carbene 1 is calculated to be 56.4 kcal/mol. The value of ΔHf 298 for the unsaturated triplet carbene 31 is calculated to be 142.8 kcal/mol, giving a singlet−triplet splitting of 86.4 kcal/mol. Addition of a proton to 1 forms 3 with ΔHf 298(3) = 171.6 kcal/mol with a proton affinity for 1 of 250.5 kcal/mol at 298 K. Addition of a hydrogen atom to 1 forms 4 with ΔHf 298(4...
Four-point bend adhesion measurements of copper and permalloy systems

Abstract The four-point bend split-beam method is used to quantitatively determine the interfacial fracture resistance and crack velocity as a function of mechanical energy release rate of the weakest interface in a thin film stack. Various interfaces of importance to magnetic storage devices are studied, including copper or nickel–iron (permalloy) on silicon oxynitride with additional adhesion promoters. The dynamics and kinetics of the four-point bend test are fully elucidated. A model for environmentally-controlled crack growth previously applied to bulk ceramics is used here as a model for interfacial crack growth and is found to fit the kinetic data.
On the Advantages and Limitations of Sliding Mode Control for Spacecraft

A number of papers have been written exploring the application of Sliding Mode Control to spacecraft positional and attitude control using thrusters. However, these papers usually consider only the control aspect of the problem. In that respect, Sliding Mode Control yields excellent performance. However, an oft neglected factor in this analysis is fuel consumption. Particularly in space, fuel is a precious commodity that is like a lifeline for a spacecraft. In this paper we consider the fuel usage for sliding mode control used to achieve orbital rendezvous. It is found that the exceptional performance of the sliding mode controller comes at a cost of significant fuel usage. In its stead, we propose a more fuel efficient controller, that takes longer to achieve rendezvous, but minimizes the fuel used to do so. Nomenclature k0 Altitude of target orbit r Relative position of chase vehicle in R direction c Relative position of chase vehicle in C direction o Relative position of chase vehicle in O direction s Sliding variable ui Acceleration in direction i m(t) Mass at time t Ti Thrust in direction i vrel Relative velocity of the exhaust gases from the thruster di Disturbance (perturbation) in direction i H Hamiltonian of the system x State variables p Co-state variables
FEASIBILITY OF THE EXPERIMENTAL DETECTION OF LONG-RANGE RETARDED DIPOLE FORCES.

Abstract The effect of the long range retarded dipole forces on the total elastic cross section for atom-atom scattering was calculated using the recently published potential of O'Carrol and Sucher and the Landau-Lifschitz approximation and found to be less than 0.5%. For HeHe scattering at very low energies, differences of a few percent exist in the region of the Ramsauer-Townsend minimum in the cross section versus energy curve.
Mutations in conserved domain II of the large (L) subunit of the Sendai virus RNA polymerase abolish RNA synthesis.

Abstract The large (L) protein of Sendai virus complexes with the phosphoprotein (P) to form the active RNA-dependent RNA polymerase. The L protein is believed to be responsible for all of the catalytic activities of the polymerase associated with transcription and replication. Sequence alignment of the L proteins of negative-strand RNA viruses has revealed six conserved domains (I–VI) thought to be responsible for the enzymatic activities. Charged-to-alanine mutagenesis was carried out in a highly charged, conserved region (amino acids 533–569) within domain II to test the hypothesis of Muller et al. [ J. Gen. Virol. 75, 1345–1352 (1994)] that this region may contribute to the template binding domain of the viral RNA polymerase. The mutant proteins were tested for expression and stability, the ability to synthesize viral RNA in vitro and in vivo , and protein–protein interactions. Five of the seven mutants were completely defective in all viral RNA synthesis, whereas two mutants showed significant levels of both mRNA and leader RNA synthesis. One of the transcriptionally active mutants also gave genome replication in vitro although not in vivo . The other mutant was defective in all the replication assays and thus the mutation uncoupled transcription and replication. Because the completely inactive L mutants can bind to the P protein to form the polymerase complex and the polymerases bind to the viral nucleocapsid template, these amino acids are essential for the activity of the L protein.
Enhanced efficiency in ZnPc/C 60 organic photovoltaic cells incorporating organic interlayers on anode

We demonstrate a clear dependence of the growth and photovoltaic performance of zinc phthalocyanine (ZnPc) films on the presence of dual organic interlayers of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and tetracene on the transparent indium-tin oxide anode. The PEDOT:PSS layer enables the two-dimensional growth of tetracene, which in turn leads to enhanced molecular packing and exciton diffusion in the ZnPc film. Coupled with exciton blocking provided by tetracene, this results in a more than 100% increase in the external quantum efficiency for ZnPc absorption in bilayer ZnPc/C60 devices. The power conversion efficiency is increased from 2.0% to 3.5% for bilayer devices, and from 3.8% to 5.0% for the more efficient planar-mixed devices.
BAFF Receptor Regulation of Peripheral B-Lymphocyte Survival and Development

B-lymphocyte homeostasis depends on exogenous signals for survival during development and in immune responses to invading pathogens. These signals are continually provided by either tonic or antigen-mediated BCR signals and other trophic factors. B-cell-activating factor (BAFF) has emerged as a key growth factor for B lymphocytes. Through its interaction with a TNF-R family member, BAFF-R or BR3, BAFF promotes survival of both immature and mature B cells. BAFF/BR3 interaction also facilitates BCR-induced B-cell proliferation. Thus, dysregulation of the signals emanating from these receptors leads to autoimmune disease, whereas interference with these signals leads to B-cell immunodeficiencies. Multiple signal transduction pathways, including those involving transcription factor NF-κB, appear to play critical roles in BAFF-mediated B-cell biological responses. Recent studies have revealed that BR3 and BCR are functionally linked and that Bruton’s cytoplasmic tyrosine kinase (Btk)/NF-κB signaling plays an essential role in this process. Therefore, the primary objective of this article is to discuss BR3-signaling pathways, and the cooperation with BCR signals, that regulate B-cell survival during development and activation.
Identifying interesting assertions from the web

How can we cull the facts we need from the overwhelming mass of information and misinformation that is the Web? The TextRunner extraction engine represents one approach, in which people pose keyword queries or simple questions and TextRunner returns concise answers based on tuples extracted from Web text. Unfortunately, the results returned by engines such as TextRunner include both informative facts (e.g., the FDA banned ephedra) and less useful statements (e.g., the FDA banned products). This paper therefore investigates filtering TextRunner results to enable people to better focus on interesting assertions. We first develop three distinct models of what assertions are likely to be interesting in response to a query. We then fully operationalize each of these models as a filter over TextRunner results. Finally, we develop a more sophisticated filter that combines the different models using relevance feedback. In a study of human ratings of the interestingness of TextRunner assertions, we show that our approach substantially enhances the quality of TextRunner results. Our best filter raises the fraction of interesting results in the top thirty from 41.6% to 64.1%.
Effect of Nitridation Rate on the Composition and Conductivity of Titanium Nitride Films Prepared from Sol–Gel Titania

Nitridation of TiO2 films in NH3 was studied as a function of heating rate by 14N(α, α)14N and 16O(α, α)16O nuclear resonance, Auger depth profiling, X-ray diffraction, and electrical conductivity measurements. TiN films containing minimal amount of oxygen and exhibiting the lowest resistivity were obtained when the fastest nitridation rate (70°C/min) was used. Nitridation at slower rates not only increased the film-oxygen content and electrical resistivity but also produced an oxygen concentration gradient across the film.
Effect of Age on the Development of ARDS in Trauma Patients

Study objectives The purpose of this study was to determine the independent effect of age on the risk of developing ARDS in patients with trauma. Design Prospective cohort study. Setting Level I trauma center. Measurements and results A total of 4,020 consecutive trauma patients who were > 12 years of age were identified through the Harborview Medical Center Trauma Registry over a 3-year period. During this time, 484 of the trauma patients (12%) developed ARDS, as identified by the Harborview Medical Center ARDS Registry. Patients who developed ARDS were, on average, older (mean [± SD] age, 44.0 ± 18.8 vs 40.2 ± 20.0 years, respectively; p Conclusions Age demonstrated a complex relationship with risk for ARDS development. Older patients showed increasingly higher risks for ARDS development up to 60 to 69 years of age, when the risk for ARDS declined. We concluded that older patients are at significantly greater risk of developing ARDS when compared to younger patients, while the oldest patients may be at less risk.