cssi/SciSciGPT-SciSciNet huggingface dataset:
DNA sequence of the bacteriophage gama cI gene.

THE cI gene of bacteriophage λ codes for the λ represser. This protein is both a positive and a negative regulator of gene transcription (see ref. 1 for review). These functions are mediated by the interaction of represser with two operators in the phage DNA. Both the nucleotide sequence of the λ operators2–5 and the amino acid sequence of the λ represser have been determined6. The ability of the λ represser to bind operator DNA is greatly reduced by a proteolytic cleavage which occurs, for example, during recA-dependent prophage induction in Escherichia coli7. A single mutation (λcI ind−) prevents this cleavage and inactivation of represser7,8. I present here the nucleotide sequence of the λ cI gene and identify the base change responsible for the ind− phenotype of λ represser.
The Surprising Role of Racial Hierarchy in the Civil Rights Jurisprudence of the First Justice John Marshall Harlan

The first Justice John Marshall Harlan’s status as one of the greatest Supreme Court Justices in American history rests largely upon his civil rights jurisprudence. The literature exploring the nuances of Harlan’s civil rights jurisprudence is vast. Far less attention has been paid to the reasons for Harlan’s strong civil rights views. Developing a rich sense of Harlan’s thinking has been difficult because Harlan did not leave behind a large trove of non-judicial writings. There is, however, a remarkable source of Harlan’s thought that has been largely overlooked by scholars: Harlan’s constitutional law lectures at George Washington Law School of 1897–1898. These lectures are currently housed in the Harlan papers in the Library of Congress, but they have never been published, have rarely been cited, and are largely unknown. These lectures provide extraordinary insight into Harlan’s civil rights jurisprudence. In these lectures, Harlan lays out a remarkable and surprising theory of racial hierarchy—with AngloSaxons as the superior group—that seems to be at complete odds with his egalitarian civil rights jurisprudence. He also was a staunch opponent of the immigration of inferior racial groups to the United States—particularly the Chinese. But Harlan’s theory of racial superiority did not, for the most part, lead him to disregard the rights of those citizens whom he considered to be racially inferior. On the contrary, although Harlan argued that Anglo-Saxons were the superior racial group and that all other racial groups in the nation would eventually die out, he also contended that Anglo-Saxons would preserve their superior status only if they fulfilled their sacred duty to protect the liberty interests of those citizens who had traditionally been subjugated in America—particularly African Americans. Accordingly, despite Harlan’s embrace of a robust theory of racial supremacy, Harlan emerged as the greatest civil rights jurist of the late nineteenth and early twentieth centuries.
Effect of prostaglandin duration on outcomes in transposition of the great arteries with intact ventricular septum.

Objective. To study the effects of duration of preoperative prostaglandin E1 (PGE) exposure on perioperative outcomes of the arterial switch operation in patients with transposition of the great arteries with an intact ventricular septum. Design. Retrospective chart review. Setting. Pediatric cardiac intensive care unit in a tertiary care children's hospital. Patients. All patients with transposition of the great arteries with an intact ventricular septum from 1995 to 2008. Outcome Measures. Inotropic score was calculated for all patients in the first 5 postoperative days and maximum inotropic score was recorded. Length of postoperative mechanical ventilation, fluid balance, mechanical ventilation time, as well as intensive care unit and hospital stay were recorded for all patients. Results. Study population included 59 patients, 41 (69%) underwent balloon atrial septostomy. PGE was used in 52 patients, median exposure of 59 hours, range 0 to 272 hours. Longer preoperative PGE exposure was associated with longer preoperative mechanical ventilation (P < .001). There was no association between preoperative PGE duration and cardiopulmonary bypass time, cross-clamp time, or total hospital stay. Patients with longer preoperative PGE exposure had a lower postoperative inotrope score (10 vs. 15 P = .02). Conclusion. Greater preoperative PGE exposure was associated with prolonged preoperative mechanical ventilation. Longer PGE exposure was associated with lower postoperative inotrope requirements. Aggressive efforts to avoid or shorten PGE infusion duration may not be warranted in this population.
Video resources for technology and society

Technology and society courses are offered at many colleges and universities in various forms and, often, by engineering departments. Developing and teaching courses dealing with the impact of technology on society can be enhanced by wise use of video resources. There is hardly an area of technology and society that is not the subject of study in some currently available film or video resource. In those courses whose major focus is the history of technology, videos or video series such as Ascent of Man, America, A&E Biography, The Secret Life of Machines, and Machine That Changed the World can enhance student learning. For courses dealing with the societal impact of technology, many episodes from the above are also useful. Additional help can be found in The American Experience, Living Planet, Blue Planet, The Pacific Century, Race to Save the Planet, Ken Burns' America, and A Walk Through the Twentieth Century. This paper explores many of these videos, emphasizing those materials that are useful to the professor in the classroom.
Glutamine and Glutamate Exchange between the Fetal Liver and the Placenta

The transport and metabolism of glutamine (GLN) and glutamate (GLU) during fetal development exhibit unique characteristics that clearly emphasize the importance of the interaction between the placenta and the fetal liver. GLN is delivered into the fetal circulation at a rate that is the highest of all the amino acids. In contrast, ∼90% of fetal plasma GLU is extracted by the placenta. Conversely, the fetal liver has a large net output of GLU and a net uptake of GLN. We have studied the fluxes of GLU and GLN into and out of the placenta and fetal liver, as well as their interconversion in these organs, during late gestation in sheep. In the fetus, 45% of GLN carbon taken up by the liver exits as GLU; indeed, the production of GLU from GLN is large, ∼3.7 μmol/(min.kg fetus), and accounts for virtually all of the GLU produced in the fetus. In contrast, only 6% of GLU carbon is converted to GLN in the placenta; most of the fetal plasma GLU taken up by this organ is converted to CO 2 . Remarkably, placental GLU uptake accounts for >60% of the fetal plasma GLU disposal rate. In some respects, the net output of GLU from the liver in fetuses replaces the net hepatic glucose output that is characteristic of postnatal life. We also examined GLN and GLU fluxes in pregnant sheep during either dexamethasone-induced or spontaneous parturition. At parturition, a striking reduction in GLU output from the fetal liver occurred, leading to a fall in fetal arterial GLU concentrations and a marked decrease in placental GLU uptake. These changes were progressive as parturition advanced and correlated with a marked decrease in progesterone output from the pregnant uterus.
Solving Optimal Control Problems Using hp-Version Finite Elements in Time

Apreviouslypublished temporal  nite elementmethod foroptimalcontrol problems is updated to includehigherorder hierarchical shape functions. The accuracy and power of the analysis and corresponding code are illustrated on optimal control problems with nonlinear system dynamics, using interfaces based on symbolic mathematics to automatically generate the necessary derivative expressions and nonlinear algebraic equations to be solved. The class of problems includes those that can have free or  xed  nal time, multiple phases, nonlinear/periodic boundary conditions, and control constraints. This code has been tested on a variety of problems, culminating in a three-phase, seven-state, two-control missile problem with nonlinear system dynamics, where accuracy was found to be signi cantly improved over h-version results, with potential order-of-magnitudereductions in CPU time and numbers of parameters for a given level of error.
Emotion Management: Sociological Insight into What, How, Why, and to What End?

In recounting some of the key sociological insights offered by over 30 years of research on emotion management, or emotion regulation, we orient our discussion around sociological answers to the fo...
Identifying Clusters of College Students at Elevated Health Risk Based on Eating and Exercise Behaviors and Psychosocial Determinants of Body Weight

Weight gain and an increase in overweight and obesity in college students raise serious health concerns. Weight management interventions for college-age men and women might be more effective if they were tailored to subgroups of students with similar behavioral and psychosocial characteristics associated with body weight status. The purpose of this study was to use cluster analysis to identify homogenous subgroups of college-aged men and women enrolled in a weight gain prevention study (Project WebHealth) using baseline data collected in 2008. Project WebHealth was a 15-month nutrition and physical activity intervention designed to decrease the rate of unwanted weight gain in 1,689 college students at eight geographically diverse universities in the United States. Outcome measures included anthropometrics, fruit and vegetable intake, physical activity, cardiorespiratory fitness, and psychosocial variables associated with weight status in college students. Cluster analysis was performed separately by sex using a two-step clustering procedure using weight-related eating and exercise behaviors and psychosocial variables. Cluster groupings were validated against students' measured weight status and waist circumference as indicators of health risk. The study design was cross-sectional. Results showed that three similar clusters were identified for each sex. Validity of the cluster solution was supported by significant group differences in body mass index and waist circumference with the High Risk cluster at elevated health risk compared to the others. For men, variability in eating competence and cognitive restraint scores contributed most to the difference between clusters, whereas for women, emotional eating and uncontrolled eating scores did. These findings could be used to improve effectiveness of messages and interventions by tailoring them to subgroups of college students with similar behavioral and psychosocial characteristics associated with elevated health risk.
Dosing protocol and analgesic efficacy determine opioid tolerance in the mouse

Analgesic efficacy of opioids and dosing protocol have been shown to influence analgesic tolerance. This study tested the hypothesis that there is an inverse relationship between analgesic efficacy and tolerance following continuous infusion of opioid analgesics. Furthermore, it was hypothesized that analgesic efficacy plays a minor role in determining the magnitude of tolerance following intermittent or acute administration, and that acute and intermittent administration of opioid agonists produces less tolerance than continuous infusion. Analgesic (tailflick) efficacy (τ) of etorphine, methadone, oxycodone, and hydrocodone was determined using the operational model of agonism. To induce tolerance, mice were injected with opioid agonists once (acute), once per day for 7 days (intermittent) or continuously infused for 7 days. Dose–response studies were conducted using morphine following treatment. The order of analgesic efficacy was etorphine > methadone > oxycodone ≅ hydrocodone. Infusion of the higher analgesic efficacy drug etorphine produced significantly less tolerance than the lower analgesic efficacy drugs oxycodone, methadone, and hydrocodone at equi-effective doses. In general, intermittent and acute treatment produced less tolerance compared to continuous infusion even at similar daily doses. Taken together, intermittent and acute opioid agonist administration produces minimal tolerance compared to continuous infusion. Furthermore, there is an inverse relationship between analgesic efficacy and tolerance following continuous infusion. These results suggest that opioid analgesic tolerance may be increased when sustained release dosing formulations or continuous infusions are employed clinically.
Structure-Based Design of a Novel Series of Potent, Selective Inhibitors of the Class I Phosphatidylinositol 3-Kinases

A highly selective series of inhibitors of the class I phosphatidylinositol 3-kinases (PI3Ks) has been designed and synthesized. Starting from the dual PI3K/mTOR inhibitor 5, a structure-based approach was used to improve potency and selectivity, resulting in the identification of 54 as a potent inhibitor of the class I PI3Ks with excellent selectivity over mTOR, related phosphatidylinositol kinases, and a broad panel of protein kinases. Compound 54 demonstrated a robust PD–PK relationship inhibiting the PI3K/Akt pathway in vivo in a mouse model, and it potently inhibited tumor growth in a U-87 MG xenograft model with an activated PI3K/Akt pathway.
Concerning the formation of singlet O2 during the decomposition of H2O2 catalase

Abstract 2,5-Diphenylfuran was used in a spectrophotometric assay for singlet O 2 to determine if this species were present during the reaction of catalase (H 2 O 2 :H 2 O 2 oxidoreductase, EC 1.11.1.6) with 2 H 2 O 2 . Since 2,5-diphenylfuran is a better singlet O 2 trap in 2 H 2 O than in H 2 O, all measurements have been made in 2 H 2 O. Under these conditions less than 0.5% of the total O 2 formed in the decomposition of 2 H 2 O 2 by catalase was released from the enzyme as singlet O 2 .
Spacetime perspective of Schwarzschild lensing

(November 29, 1999)We propose a deﬁnition of an exact lens equation without reference to a background spacetime,and construct the exact lens equation explicitly in the case of Schwarzschild spacetime. For theSchwarzschild case, we give exact expressions for the angular-diameter distance to the sources aswell as for the magniﬁcation factor and time of arrival of the images. We compare the exactlens equation with the standard lens equation, derived under the thin-lens-weak-ﬁeld assumption(where the light rays are geodesics of the background with sharp bending in the lens plane, andthe gravitational ﬁeld is weak), and verify the fact that the standard weak-ﬁeld thin-lens equationis inadequate at small impact parameter. We show that the second-order correction to the weak-ﬁeld thin-lens equation is inaccurate as well. Finally, we compare the exact lens equation with therecently proposed strong-ﬁeld thin-lens equation, obtained under the assumption of straight pathsbut without the small angle approximation, i.e., with allowed large bending angles. We show thatthe strong-ﬁeld thin-lens equation is remarkably accurate, even for lightrays that take several turnsaround the lens before reaching the observer.I. INTRODUCTION
Relativistic composite systems and minimal coupling

The problem of minimal coupling of relativistic composite systems having internal degrees of freedom is investigated. The ambiguity in the introduction of various internal coordinates with the same mass spectrum can be solved by probing the system with external electromagnetic interactions. For the generalized Majorana equation this procedure shows that the charged constituent of the system performs a two-dimensional Kepler motion in the Klein-Gordon approximation and not an oscillator motion.
Paper-Based Electrochemical Sensing Platform with Integral Battery and Electrochromic Read-Out

We report a battery-powered, microelectrochemical sensing platform that reports its output using an electrochromic display. The platform is fabricated based on paper fluidics and uses a Prussian blue spot electrodeposited on an indium-doped tin oxide thin film as the electrochromic indicator. The integrated metal/air battery powers both the electrochemical sensor and the electrochromic read-out, which are in electrical contact via a paper reservoir. The sample activates the battery and the presence of analyte in the sample initiates the color change of the Prussian blue spot. The entire system is assembled on the lab bench, without the need for cleanroom facilities. The applicability of the device to point-of-care sensing is demonstrated by qualitative detection of 0.1 mM glucose and H2O2 in artificial urine samples.
The Zinc Finger Cluster Domain of RanBP2 Is a Specific Docking Site for the Nuclear Export Factor, Exportin-1

The Ran-binding protein 2 (RanBP2) is a large scaffold cyclophilin-related protein expressed in photoreceptor cells. Red/green opsin, Ran-GTPase, and the 19 S regulatory complex of the proteasome associate with specific RanBP2 structural modules. Some of these play a role in chaperoning the functional expression of opsin. RanBP2 localization at cytoplasmic fibrils emanating from the nuclear pore complex and interaction with the Ran-GTPase support also its role in nucleocytoplasmic transport processes. The degenerate nucleoporin repeat motifs FXFG, GLFG, and XXFG have been proposed to mediate the movement of nucleocytoplasmic transport factors. In particular, RanBP2 has been implicated in nuclear import processes. Here, we show the zinc fingers of RanBP2 associate with high specificity to the nuclear export factor, exportin-1 (CRM1). The bovine RanBP2 transcript contained only five of the eight zinc fingers reported in the human counterpart and are sufficient for exportin-1 association with RanBP2. In contrast to Ran interaction with RanBP2-exportin-1 complex, exportin-1 binding to the zinc finger cluster domain of RanBP2 is insensitive to leptomycin B and nucleotide-bound state of Ran-GTPase. Our results indicate that the zinc finger-rich domain of RanBP2 constitutes a docking site for exportin-1 during nuclear export. Thus, RanBP2 emerges as a key component of the nuclear export pathway.
Stable co‐occupancy of transcription factors and histones at the HIV‐1 enhancer

To investigate mechanisms yielding DNase I-hypersensitive sites (DHSs) at gene regulatory regions, we have initiated a biochemical analysis of transcription factor binding and nucleosome remodeling with a region of the human immunodeficiency virus 1 (HIV-1) 5' long terminal repeat (LTR) that harbors constitutive DHSs in vivo. In vitro reconstitution of an HIV-1 5' LTR fragment into nucleosome core particles demonstrates that Sp1, NF-kappaB1, LEF-1, ETS-1 and USF can gain access to their binding sites in HIV-1 nucleosomal DNA. The factor-bound mononucleosomes resist histone displacement from the DNA by the chromatin remodeling activity, SW1-SNF, or the histone chaperone, nucleoplasmin, suggesting that the binding of these factors to nucleosomal HIV-1 sequences forms a stable complex that includes the underlying histones. However, when the HIV-1 5' LTR fragment is incorporated into a nucleosomal array, Sp1 and NF-kappaB1 binding produce regions of enhanced DNase I sensitivity specifically at the HIV-1 nucleosome. These regions resemble the observed in vivo DHSs, yet the HIV-1 nucleosome remains intact even in the presence of nucleoplasmin. Thus, the constitutive DHSs identified at the HIV-1 enhancer in native chromatin may reflect the presence of a ternary complex composed of transcriptional activators, histones and DNA.
Endings, secrets, and silences: overreading in narrative inquiry.

Qualitative researchers seek to understand the words of the people they interview and may use narrative inquiry to find meaning in the stories told by research participants. Narrative inquiry entails “overreading,” a sensitivity to unspoken or indirect statement, which is central to interpretation. Some of the tools of the literary overreader are applied to two research interviews, particularly as they direct readers to attend to inconsistencies, endings, repetitions, and silence. Because overreading is also intrusive, we conclude with some considerations about how far the overreader of the research may legitimately go. © 1997 John Wiley & Sons, Inc. Res Nurs Health 20: 551–557, 1997
Keloid Fibroblasts Exhibit an Altered Response to TGF-|[beta]|

Treatment with transforming growth factor beta 1 (TGF-beta 1) results in stimulation of total protein synthesis in normal dermal fibroblasts but not in keloid fibroblasts, suggesting that the TGF-beta regulatory program is altered in keloid fibroblasts. However, both keloid and normal fibroblasts treated with TGF-beta 1 exhibit accelerated fibronectin biosynthesis, indicating that keloid cells can respond to TGF-beta 1. In the absence of serum, the TGF-beta 1-induced increase in fibronectin biosynthesis occurs more rapidly in keloid fibroblasts, also suggesting modification of this regulatory pathway. The TGF-beta 1-mediated increase in keloid fibronectin production is independent of the steroid regulatory pathway for fibronectin, which accelerates synthesis by means of a post-transcriptional mechanism. Thus, TGF-beta 1 stimulation of fibronectin production in keloid cells is likely to involve a transcriptional mechanism and keloid overproduction of extracellular matrix components may be due to an inherent modification of the TGF-beta regulatory program.
On the solution of some minimax problems

In dynamic minimax and stochastic optimization problems frequently one is forced to use a suboptimal controller since the computation and implementation of the optimal controller based on dynamic programming is impractical in many cases. In this paper we study the performance of some suboptimal controllers in relation to the performance of the optimal feedback controller and the optimal open-loop controller. Attention is focused on some classes of, so called, open-loop-feed-back controllers. It is shown under quite general assumptions that these open-loop-feedback controllers perform at least as well as the optimal open-loop controller. The results are developed for general minimax problems with perfect and imperfect state information. In the latter case the open-loop-feedback controller mkes use of an estimator which is required to perform at least as well as a pure predictor in order for the results to hold. Some of the results presented have stochastic counterparts.
Circulating ghrelin, leptin, and soluble leptin receptor concentrations and cardiometabolic risk factors in a community-based sample.

Context: The conjoint effects and relative importance of ghrelin, leptin, and soluble leptin receptor (sOB-R), adipokines involved in appetite control and energy expenditure in mediating cardiometabolic risk, is unknown. Objective: The objective of the study was to study the cross-sectional relations of these adipokines to cardiometabolic risk factors in a community-based sample. Design, Setting, and Participants: We measured circulating ghrelin, leptin, and sOB-R in 362 participants (mean age 45 yr; 54% women) of the Framingham Third Generation Cohort. Main Outcome Measures: Body mass index, waist circumference (WC), blood pressure, lipid measures, fasting glucose, smoking, and metabolic syndrome (MetS) were measured. Results: Ghrelin and leptin concentrations were significantly higher in women (P < 0.0001). In multivariable models, ghrelin was inversely associated with age and systolic blood pressure, and leptin was positively related to body mass index and WC. sOB-R was positively associated with age, total cholesterol, and fasting glucose and inversely with WC and high-density lipoprotein cholesterol. Ghrelin and sOB-R concentrations were significantly lower with number of MetS components (P for trend = 0.022 and < 0.0001, respectively), whereas leptin concentrations were higher (P for trend = 0.0001). Relating all adipokines to MetS conjointly, higher ghrelin and leptin concentrations were associated with decreased and increased odds of MetS (odds ratio 0.55, P < 0.0001; odds ratio 4.44, P = 0.0002, per 1 sd increase of respective log adipokine). Conclusions: In our community-based sample, we observed a sexual dimorphism in circulating ghrelin and leptin concentrations. Ghrelin, leptin, and sOB-R were associated with number of MetS components cross-sectionally, consistent with the hypothesis that these adipokines may have a central role in cardiometabolic risk.
Achieving the goal of a quality teacher of reading for every classroom: Divest, test, or invest?

Book reviewed in this article: Learning to Teach Reading: Setting the Research Agenda. Edited by Cathy Roller. 2001. Meeting the Highly Qualified Teachers Challenge: The Secretary's Annual Report on Teacher Quality. 2002. U.S. Department of Education, Office of Postsecondary Education, Office of Policy Planning and Innovation. No Dream Denied: A Pledge to America's School Children. 2003. National Commission on Teaching and America's Future. Quality Counts 2003: “If I Can't Learn From You….” 2003. Education Week. Teacher Certification Reconsidered: Stumbling for Quality. 2001. The Abell Foundation.
Preparation and characterization of maleimide-terminated poly(arylene ether sulfone) oligomers of various molecular weights

A new variation in the bismaleimide (BMI) resin family, maleimide-terminated poly(oxy-1,4-phenylene sulfonyl-1,4-phenylene) oligomers, has been synthesized. The preparation of oligomers (n = 1–12) is described in this study. The structure of these oligomers is characterized by FT-IR and NMR spectroscopy. These oligomers are light yellow to light gray powders that can be melted or dissolved in solvents. Their terminating group bismaleimide has relatively high reactivity. Therefore, these BMI resins can be cured at 250°C to form a crosslinked product. Since the backbone chain is poly(arylene ether sulfone), the cured polymers have high Tg's, which increased from 220°C to higher than 340°C as the number of repeating units n of the corresponding oligomers decreases.
Studies on electrocyclization in bicyclo[4.4.1]undeca-2,4-diene and bicyclo[4.2.1]nona-2,4-diene systems

Photoinduced electrocyclization of substituted bicyclo[4.4.1]undecadienes and bicyclo[4.2.1]nonadienes, derived from chromium(0)-promoted [6π+4π] and [6π+2π] cycloadditions, respectively, afforded polycyclic products possessing substantial stereochemical information.
Optical characterization of CMOS compatible micro optics fabricated by mask-based and mask-less hybrid lithography

We report a CMOS compatible fabrication and optical characterization of the micrometer scale optical coupler, a 45° mirror-based optical coupler for inter-layer optical coupling. A newly proposed mask-based and mask-less hybrid lithography process enables accurate surface profile of the micrometer sized 45° mirror by using a CMOS compatible buffer coat material. Surface profile inspected by an optical interferometry agrees well with SEM based inspection results. Experimental and theoretical results for routing and coupling of laser beam in 90° will be discussed.
April 12, 1955: Tommy Francis and the Salk Vaccine

April 12, 1955, was supposed to be Tommy Francis's day, writes Dr. Howard Markel. The distinguished epidemiologist was scheduled to conduct an international press conference on the field trial he had just completed, evaluating the efficacy of the poliovirus vaccine developed by Jonas Salk.
How to do discretionary access control using roles

Role-based access control (RBAC) is a promising alternative to traditional discretionary access control (DAC) and mandatory access control (MAC). The central idea of RBAC is that permissions are associated with roles, and users are made members of appropriate roles thereby acquiring the roles’ permissions. RBAC is policy neutral in that the precise policy being enforced is a consequence of how various components of RBACsuch as role hierarchies, constraints and administration of user-role and role-permission assignment-are configured. This raises the important question as to whether RBAC is sufficiently powerful to simulate DAC and MAC. Simulation of MAC in RBAC has been demonstrated earlier by Nyanchama and Osborn and by Sandhu. In this paper we demonstrate how to simulate several variations of DAC in RBAC, using the wellknown RBAC96 model of Sandhu et al. In combination with earlier work we conclude that RBAC encompasses both MAC and DAC.
Tissue oxygen distribution in head and neck cancer patients.

Background The importance of hypoxia in limiting the sensitivity of tumor cells to ionizing radiation has long been known. Methods We evaluated the tissue oxygenation status with a polarographic needle electrode system in 37 patients with malignancies of the head and neck and correlated the pO2 of 25 patients with treatment outcome. Results Sixteen tumors contained areas of severe hypoxia, defined by pO2 values below 2.5 mm Hg. Tumor oxygenation parameters were not correlated with hemoglobin, age, and history of tobacco use. There were no subcutaneous pO2 values below 10 mm Hg (ie, no areas of moderate or severe hypoxia), whereas this degree of hypoxia was commonly found in the tumors. Though not statistically significant, hypoxic tumors showed trends for poorer treatment outcome. Conclusion Our data demonstrate a great interindividual variability in the oxygenation of head and neck cancers and appears unassociated with clinical parameters. The method is capable of identifying patients with poorly oxygenated tumors, thereby providing important information for selecting patients who might need customized therapy designed to kill hypoxic tumor cells. Hypoxic tumors show a consistent trend for poor treatment outcome. © 1999 John Wiley & Sons, Inc. Head Neck 21: 146–153, 1999.
Relationships of positive and negative affect to coping and functional outcomes in systemic sclerosis

This study examined the role of two distinct factors of emotion, positive (PA) and negative affect (NA), in adjustment to a chronic rheumatic disease, systemic sclerosis (SSc). Ninety-two patients with a confirmed diagnosis of SSc completed self-report measures assessing PA and NA (Positive and Negative Affect Schedule), coping (Revised Ways of Coping Checklist), and functional outcomes (pain and disability measured with the Health Assessment Questionnaire). Confirmatory factor analysis indicated that PA and NA constituted separate, negatively correlated factors. PA and NA showed differential relationships to coping and functional outcomes. Affect mediated the association between coping and functional outcomes after controlling for disease severity. The results suggest the importance of both PA and NA as factors influencing adjustment to chronic illness.
Improving results of open arch replacement.

Background The rapid evolution of endovascular approaches to arch reconstruction such as brachiocephalic debranching and endovascular stent grafting renders an accurate understanding of contemporary outcomes of conventional open arch surgery particularly relevant. Methods Cases of arch reconstruction were identified by search of the computerized cardiovascular surgical database. Perioperative (30-day) outcomes as per The Society of Thoracic Surgeons database were evaluated. Results Between January 1, 1993, and June 30, 2007, 347 patients (195 male, 152 female; median age, 69 years; range, 21 to 88 years) underwent aortic arch replacement. Procedures were elective in 232 cases. Total arch replacement was performed in 95, including 15 with concomitant replacement of the descending thoracic aorta by means of bilateral thoracosternotomy. Modalities adjunctive to profound hypothermia and circulatory arrest for cerebral protection have been introduced, including retrograde cerebral perfusion and, more recently, selective antegrade cerebral perfusion. The overall mortality rate was 8.9% (elective procedures, 6.0%) and stroke rate was 8.4% (elective procedures, 6.9%). The mortality rate for total arch replacement has declined with adjuncts overall from 34.6% (9 of 26) with profound hypothermia and circulatory arrest to 21.1% (4 of 19) with retrograde cerebral perfusion and to 6.0% (3 of 50) with selective antegrade cerebral perfusion ( p p p = 0.18) overall and 15.0% (3 of 20) with profound hypothermia and circulatory arrest, 7.1% (1 of 14) with retrograde cerebral perfusion, and 5.4% (2 of 37) with selective antegrade cerebral perfusion ( p = 0.46) for elective cases. Conclusions Currently, open aortic arch replacement can be accomplished under elective circumstances with low operative mortality, particularly with adjunctive measures for cerebral protection. The results of endovascular therapies should be measured against contemporary surgical series.
A New Theory of Non-Linear Viscous Elasticity

The stress-strain curve of a material is calculated on the hypothesis that when flow occurs a section of the molecular chain constituting the material changes from a configuration A to a con figuration B and thereby becomes unable to elongate again. Except for a small elastic deformation of both structures, the elongation is proportional to the fraction of the material in the B configura tion. The two components are assumed to be in solution with one another, and the rates of trans formation are then proportional to the relative abundance of the transformed species. These rates are written in the manner of the Eyring theory of reaction rates. Systems of more than two com ponents are discussed and several examples are calculated. The calculated curves show good qualitative agreement with stress-strain curves of the nylon-wool-rubber type.
Transport of thiamine and 4-methyl-5-hydroxyethylthiazole by Salmonella Typhimurium

The transport of thiamine and 4-methyl-5-hydroxyethylthiazole (MHET), its thiazole moiety, was studied using whole cells of Salmonella typhimurium. It was found that the bacteria possessed an active transport system for thiamine that had Km 0.21 microM and Vmax 33 nmol.min-1.(mg dry wt. cells)-1. Transport of thiamine was glucose dependent, whereas MHET uptake was dependent on both glucose and 2-methyl-4-amino-5-hydroxymethylpyrimidine (MAHMP), the pyrimidine moiety of thiamine. Uptake of both thiamine and MHET was severely curtailed by cyanide, azide, N-ethylmaleimide and carbonyl cyanide m-chlorophenylhydrazone. Oxythiamine inhibited thiamine, but not MHET, uptake and thiamine slightly inhibited MHET uptake. 2-Methyl-4-amino-5-methoxymethylpyrimidine and 4-amino-5-hydroxymethylpyrimidine were unable to replace MAHMP as stimulators of MHET uptake, but 2-methyl-4-amino-5-aminomethylpyrimidine was marginally effective in this regard. Similar results were obtained with attempts to replace MAHMP as a growth requirement for a purD mutant of Salmonella typhimurium. MHET uptake showed saturation kinetics only in the presence of MAHMP, and is not otherwise actively transported.
Temperature, stress, disorder, and crystallization effects in laser diodes: measurements and impacts

This paper reviews extensive Raman scattering, reflectance modulation and luminescence microprobe measurements made on GaInP/AlGaInP, GaAs/AlGaAs and InGaAs/AlGaAs ridge quantum well lasers to investigate (i) laser operating temperatures, (ii) built-in mechanical stress, (iii) atomic disorder in mirror facets, (iv) Si recrystallization effects in mirror coatings, and (v) correlations of these parameters with laser performance and reliability data. Mirror temperatures have been found to depend sensitively on mirror treatment, mirror structure design, the geometry of a deposited heat spreader, the type of coupling of the laser to a heat sink, the number of active quantum wells, the type of cladding layer, and the strength of lattice disorder at the mirror surfaces. Axial temperatures drop from the hot mirror side along the cavity to low constant values within typically 10 μm. Degradation processes have been observed in real time by continuously monitoring the mirror temperature. Dark line defects formed during laser operation exhibit a temperature gradually increasing with time. The mirrors suffer catastrophic optical damage within seconds after having reached a critical temperature. Temperature maps show a striking localized hot spot within the optical near-field pattern. Strong structural and compositional lattice disorder have been identified as potential root causes of strong mirror heating. Disorder strongly suppresses the catastrophic optical mirror damage power limit. Ridge waveguide lasers show a characteristic camel hump-like stress profile, i.e. high compressive strain levels of up to 5 kbar near the ridge slopes and reduced compressive stress or even low tensile stress fields towards the ridge center. The measured stress fields affect the formation of defects and the optical near-field pattern. Ion-beam deposited amorphous Si layers in mirror coating stacks rapidly recrystallize under high power exposure. This reduces the reflectivity of the coating and increases the transmitted power. Model experiments demonstrate that the recrystallization can modify the effective kink-free optical output power.
Phytate: A good or a bad food component?

Abstract Since phytate was first identified as a naturally-occurring organic compound found in all plant life, phytate has been badly maligned. Most studies concentrated on its mineral-binding capacity which may result in marginal or frank mineral deficiencies in animals and humans. Currently, there is evidence that dietary phytate may have beneficial effects. Positive effects against carcinogenesis have been shown with in vitro cell culture systems, in mice, rats and guinea pigs, but the mechanism of action is not understood. Additional foods have been analyzed for phytate content, albeit by methodology which does not differentiate between phytate and it's hydrolysis products. Analytical methodology is now available which provides precise estimates of phytate and inositol phosphate hydrolysis products in foods thereby making possible a database from which more precise estimates of the extent to which mineral homeostasis may be compromised. Microbial phytase preparations are being studied as a means of improving the utilization of dietary phytate phosphorus, decreasing the need for inorganic phosphorus supplements in animal feeds and, in turn, lessen the environmental impact of phosphorus in excreta from animal feeding operations. Thus, there is a strong impetus to continue the study of this naturally-occurring molecule and what we learn through further study will hopefully improve the quality of life.
Nurse Gordon on Trial: Those Early Days of the Birth Control Clinic Movement Reconsidered

This essay concerns a woman by the name of Adele Gordon. Adele Gordon was a nurse who, during the 1930s, operated a commercially-sponsored birth control clinic in the city of Milwaukee and who, in 1935; was arrested and tried for precisely these activities. However, while her story is the guiding theme of this narrative, her life (as well as the lessons to be learned from the history of medicine) invites us to consider the larger world in which her work took place, in particular the early days of the birth control clinic movement. Indeed, what this essay asks us to imagine is the presence of what I call the Irregular birth control clinic movement, a movement of clinics which continued to embody the supposedly lost radicalism of Margaret Sanger in the teens. And this Irregular clinic movement, in turn, invites us to re-think the efforts of the American Birth Control League in its quest for professionalization and the backing of the American Medical Association. Hence Nurse Gordon's story is an important one in part, because she is an intriguing individual who embodied an uncommon sense of modesty and determination, dignity and pride. But also because Nurse Gordon offers us a new way to tell the story of twentieth-century birth control, encouraging us to appreciate the breadth of the birth control clinic movement, the malleability of the birth control institution, and the American Birth Control League's efforts to contain them both.
Construction of low-complexity highly efficient deterministic modulation codes with adjustable codeword length and error control capability

Run-length limited RLL(0,k) modulation or k-constrained codes are being used in optical and magnetic recording systems. In this paper a new methodology for the construction of highly efficient modulation codes and in particular new enhanced RLL(0,k) coding schemes are presented. The new methodology generates modulation codes computationally simpler than the existing ones, empowered with partial error detection (PED) capability at the demodulator for improved error control reliability. An increased list of constraints is formed, rather than just constraints pertaining to d, k, I only. Even though concatenation of conventional RLL with ECC can reduce the effectiveness of the ECC, especially with a sliding block encoder/decoder subject to error propagation, a concatenated PED capability can boost the outer ECC performance. Note that in current system using low redundancy ECC, the overall rate is mainly determined by the modulation code rate which critically is to be maintained high. RLL/PED code rates of 8/9, 16/17, 24/25 and 32/33 or higher are achievable. The proposed fixed length block decodable RLL/PED, are generalized schemes of the type: n/n + 1(d equals 0, k equals n - 1/I equals n), and n/n + 1(d equals 0, k equals(n/2/I equals n) where n (epsilon) (Zeta) $GREG5 . The encoding/decoding/error-control equations and the global k and interleave I-constraints, are expressed as functions of n, so that fixed encoder/decoder/error-control architectures are obtained in terms of any adjustable work length n, and consequently any code rate n/n + 1. They are characterized by computational simplicity irrespective of the codeword length n, or the code rate. Applicability of the proposed methodology in the construction of Maximum Transition Run codes, is also addressed.
Market structures for wireless services with shared spectrum

There has been much recent interest in allowing commercial providers to utilize federal spectrum on a shared basis. In such scenarios, the use of secondary licenses has been proposed as a way to provide service providers with greater predictability about the service that can be offered and thus help encourage investment. However, since the spectrum is shared, such a license would differ from traditional exclusive use licenses in that the given spectrum may only be intermittently available. In this work we discuss several issues related to such intermittent spectrum and in particular consider different market structures for allocating such secondary licenses to different service providers. In each case we characterize the complexity of the underlying efficient allocation problem and discuss market mechanisms for implementing such an outcome.
Management of adults with congenital bidirectional cardiac shunts, cyanosis, and pulmonary vascular obstruction: Successful operative repair in 3 patients☆

Abstract Patients with congenital cardiac shunts in whom marked functional disability, cyanosis and pulmonary arterial hypertension develop have been considered inoperable or at exceedingly high risk. Three adult patients, 2 with atrial septal defect (ASD) and 1 with patent ductus arteriosus (PDA), presented with New York Heart Association class IV symptoms, bidirectional shunting with cyanosis, polycythemia, severe pulmonary hypertension, and increased pulmonary vascular resistance. Pulmonary arterial pressure did not decrease in response to administration of 100% oxygen in any patient, and 2 had lung biopsy results showing advanced pulmonary vascular obstruction. While a right-to-left shunt caused cyanosis in all patients, the net shunt was left to right ( Q p Q s > 1 ) and the resistance ratio ( R p R s ) . All 3 patients survived operation, became acyanotic with normal hematocrit, and are in functional class I or II a mean of 36 months post-operatively. At repeat cardiac catheterization, pulmonary arterial pressure and resistance had decreased substantially. This high-risk group of patients with bidirectional shunts, in whom cyanosis due to pulmonary vascular obstruction and polycythemia develop and who appear to be at very high operative risk, should still be considered for surgical correction if the usual criteria for operability exist: net left-to-right Q p Q s and R p R s .
Analysis of Hydrothermal Vent-Associated Symbionts by Ribosomal RNA Sequences

Ribosomal RNA (rRNA) sequences were used to establish the phylogenetic affiliations of symbioses in which prokaryotes appear to confer sulfur-based chemoautotrophy on their invertebrate hosts. Two submarine hydrothermal vent animals, the vestimentiferan tube worm Riftia pachyptila and the clam Calyptogena magnifica, and a tidal-flat bivalve , Solemya velum, were inspected. 5S rRNA9s were extracted from symbiont-bearing tissues, separated into unique forms, and their nucleotide sequences determined and related to other 5S rRNA9s in a phylogenetic tree analysis. The prokaryotic symbionts are related to one another and affiliated with the same narrow phylogenetic grouping as Escherichia coli and Pseudomonas aeruginosa. The sequence comparisons suggest that Riftia is more closely related to the bivalves than their current taxonomic status would suggest .
A method for assessing the market potential of new energy-saving technologies

An approach for estimating the market potential of new energy saving technologies is presented. The approach is based on the assumption that consumers implicitly minimize total expected lifetime costs when purchasing new technology. The techniques developed allow simultaneous comparison of any number of competing technologies. An important result of this approach is that technologies can have zero market potential and that these technologies can be identified based solely on technology-specific information, not on attributes of the consumer population. An application of the model is made to the study of market potentials for new automotive technologies.
Issues of Representation in eHealth Research (with a Focus on Web Surveys)

The growth of eHealth research has been both rapid and sustained over the past several years. As part of this growth, the Internet is increasingly being used, both to deliver online interventions, and to collect data from a wide variety of groups of people. This paper reviews some of the issues around the latter use of the Internet, and in particular, the use of web surveys to produce results intended to be generalizable to a broader population. The paper provides an overview of issues of sample representation and the challenges faced in using Internet surveys. Various methods of sample selection, and their strengths and weaknesses are reviewed, and the threats to valid inference are discussed.