cssi/SciSciGPT-SciSciNet huggingface dataset:
Composition dependence of lattice parameters in ANb1−xVxO4 systems whereA = Ce, Nd

Abstract The room-temperature lattice parameters of a series of CeNb 1− x V x O 4 and NdNb 1− x V x O 4 compounds (0 ≤ x ≤ 1) have been measured. Substitution of vanadium for niobium in both CeNbO 4 and NdNbO 4 drives the structure from monoclinic (fergusonite type) to tetragonal (scheelite type) at x = 0.296 and 0.346, respectively. In both systems, there is an expansion of the long-axis dimension of the fergusonite structure as x increases, despite the fact that vanadium is a smaller ion than niobium. This leads to an anomalous variation of the unit cell volume with concentration. The composition dependence of the strain parameters, which are a measure of the relative distortion of the monoclinic lattice, is found to fit a Landau mean-field model, thus demonstrating a thermodynamic correspondence between composition and temperature.
Formation mechanism of ring domains in a TbFeCo magneto-optical medium

The formation mechanism of stable ring domains in a TbFeCo magneto-optical medium with compensation temperature below the ambient temperature is discussed. A ring-domain formation model is proposed.
“Just Caring”: Can We Afford the Ethical and Economic Costs of Circumventing Cancer Drug Resistance?

Personalized medicine has been presented in public and professional contexts in excessively optimistic tones. In the area of cancer what has become clear is the extraordinary heterogeneity and resilience of tumors in the face of numerous targeted therapies. This is the problem of cancer drug resistance. I summarize this problem in the first part of this essay. I then place this problem in the context of the larger political economic problem of escalating health care costs in both the EU and the US. In turn, that needs to be placed within an ethical context: How should we fairly distribute access to needed health care for an enormous range of health care needs when we have only limited resources (money) to meet virtually unlimited health care needs (cancer and everything else)? This is the problem of health care rationing. It is inescapable as a moral problem and requires a just resolution. Ultimately that resolution must be forged through a process of rational democratic deliberation.
An extension of a result of Burdzy and Lawler

It is shown that for all mean zero, finite variance random walks, the critical non-intersection exponents are equal to those for Brownian motion. The method uses the local time of intersection.
DEVELOPMENT OF A COLD‐TOLERANT POPULATION OF RED TILAPIA THROUGH INTROGRESSIVE HYBRIDIZATION

A population of red tilapia with cold tolerance traits similar to Tilapia aurea has been produced using introgressive breeding techniques, i.e., hybridization (female T. aurea x male red tilapia, heterozyqous for red trait) followed by backcrossing (female T. aurea x F-1 male, red phenotype). Progeny of the F-1 backcross, consisting of approximately 50% normal and 50% red phenotype, survived longer under conditions of ambient cooling than either T. aurea or T. mossambica (P 0.05). Mean lower lethal temperatures for the three groups were: T. aurea (11.6 °C), T. mossambica (13.8 °C), and F-1 backcross, red and normal phenotypes pooled, 10.0 °C.
Thinking Through Language

L'A. examine les theories et les methodologies a notre disposition pour repondre a la question suivante : la structure de la langue que l'on parle affecte-t-elle notre maniere de penser ?
How Gender Roles Influence Sexual and Reproductive Health Among South African Adolescents

Although the literature on Africa increasingly adopts a gendered approach to sexual and reproductive health issues, few studies have addressed adolescent pregnancy and parenthood in such a framework. This article examines links between gender ideology or gender roles and the social impact of adolescent childbearing in the lives of rural and urban adolescents in KwaZulu/Natal, South Africa. It employs a triangulated research methodology (focus-group discussions, narrative role playing and discussions, and questionnaires and in-depth interviews) to inform an analysis of adolescents' notions of male and female gender ideals. This analysis forms the basis for an exploration of the potential influence of adolescent childbearing on young peoples' lives and factors that shape their sexual and reproductive well-being. Results indicate that gender ideals are grounded in traits that reinforce poor sexual negotiation dynamics and behavioral double standards and that place adolescents at risk for early pregnancy and other sexual and reproductive health complications. Overall, adolescent parenthood is viewed negatively by participants of both sexes because it compromises personal, professional, and financial aspirations. Compared with its effect on boys, parenthood has a disproportionate (and highly negative) impact on girls that is directly linked to gender-based inequities. The article addresses the research and policy implications of these findings.
Did the Price of the Internet Drop

No statistic would seem as important to know as the price of the Internet. You might reasonably respond, How can the Internet have a price attached to it? As it turns out, there are many such prices. A particularly interesting one is the consumer price index (CPI) for Internet access, which focuses on the retail price of a household connection. This price index does not get enough attention because observers confuse future opportunity with recent history. One other thing motivates an examination of this index. There is a big debate in the US about whether the broadband market has been organized intelligently. Economic statistics can inform policy debates, that is, if they get interpreted the right way. However, and this is my point in this column, the index is easy to misinterpret. It is worth a close look.
Linear stability conditions for a first-order three-dimensional discrete dynamic

Linear stability conditions for a first-order three-dimensional discrete dynamic are derived in terms of the trace, determinant, and sum of principle minors of the Jacobian evaluated at the equilibrium.
Scoring Points: Politicians, Activists, and the Lower Federal Court Appointment Process. By Nancy Scherer

Scoring Points: Politicians, Activists, and the Lower Federal Court Appointment Process. By Nancy Scherer. Stanford, CA: Stanford University Press, 2005. Pp. 272. $65.00 cloth; $24.95 paper. Reviewed by Sally Kenney, University of Minnesota Why have appointments to the lower federal courts become so politicized in the modern era? Scherer's answer is that senators who once dispensed judicial appointments as political patronage now face mobilized elites who demand that lower court judges share their ideology. She deploys diverse methodological approaches to develop her argument: statistical analyses of judicial cohorts' decisions, interviews with activists, an analysis of legislative rules and practices, and an examination of campaign rhetoric and strategies. While Scherer situates her study squarely in the context of American politics and political science, the book has much to teach specialists in the politics of judicial selection. Two huge political changes precipitate the change: the decline of mass parties (and candidates' concomitant dependence on elites to mobilize voters) and the increased importance of federal courts. First evidenced by President Lyndon Johnson (not President Roosevelt), but really starting with President Richard Nixon's Southern strategy and his promise to appoint "law and order judges," presidential candidates appeal to elites to "score points." By examining judicial votes, Scherer demonstrates that party-polarized judicial decisionmaking did not occur until the late 1960s, but she provides strong evidence that it has occurred thereafter. I would recommend the book for undergraduate courses in American politics, judicial politics, or even Congress. I would also recommend it for graduate courses such as judicial politics or law and policy. Scherer quotes activists effectively to reveal their strategies. The chapter on the Senate's process of judicial selection is especially informative and could stand alone. Activists looking for powerful evidence of hypocrisy in Republicans' current demands for an up-or-down vote or for the elimination of the filibuster will find plenty of ammunition. Since the demise of patronage and senatorial courtesy, senators have not been able to agree on the rules of the game-rather, they shift according to the party in power and the party of the president. Partisans aggrieved at the framing of Democrats as distinctly obstreperous will be delighted to know that it was President Nixon who developed the ideological litmus test, and Scherer concludes that "the exploitation of the ideological litmus tests remains predominately a Republican elite mobilization strategy" (p. …
Determination of 10 carcinogenic polycyclic aromatic hydrocarbons in mainstream cigarette smoke

Polycyclic aromatic hydrocarbons (PAHs) are one class of chemical compounds that (1) are present at low to trace levels in unburned cigarette filler, and (2) are predominantly generated during combustion. According to a recent report of the International Agency for Research on Cancer, 10 carcinogenic PAHs together with 53 other known carcinogens are present in cigarette smoke. Accurate quantification of these chemicals helps assess public health risk to both smokers and nonsmokers exposed to second-hand smoke. We have developed and validated a specific and sensitive method for measuring these 10 carcinogenic PAHs in the particulate phase of mainstream tobacco smoke. Cigarette smoke particulate, produced using standard machine smoking protocols, was collected on glass fiber Cambridge filter pads. The particulate matter was solvent extracted, purified by solid-phase extraction, and analyzed by liquid chromatography/atmospheric pressure photoionization tandem mass spectrometry using isotopically labeled analogues as internal standards. Our method's limits of detection ranged from 11 to 166 pg and achieved sufficient reproducibility and accuracy to provide useful information on a range of cigarettes having dramatically different machine-smoked tar and nicotine deliveries. The identity of each PAH analyte was established from chromatographic retention time, analyte-specific fragmentation patterns, and relative peak area ratios of the product/precursor ion pairs. This new method provides higher sensitivity, specificity, and throughput than did earlier methods. We found relatively consistent PAH levels among a selection of domestic full-flavor cigarettes. The PAH levels in smoke from highly ventilated light and ultralight cigarettes were low when smoked using ISO (International Organization for Standardization) conditions. However, if highly ventilated cigarettes were smoked under more intense conditions (e.g., larger or more frequent puffs, vents blocked), their PAH levels equaled or exceeded their full-flavor counterparts under ISO conditions.
Metabolic relationships between myelin subfractions: entry of proteins.

— Partially purified myelin from brains of 17-day-old rats was separated into 4 subfractions on a discontinuous sucrose gradient by virtue of heterogeneity in density and particle size. The protein composition of each subfraction was determined by densitometry following separation of proteins on polyacrylamide gels in buffers containing sodium dodecyl sulphate. The major proteins studied included two basic proteins, proteolipid protein, the major high molecular weight protein (W) and a group of high molecular weight proteins. The percentage of high molecular weight proteins decreased sequentially from fraction D to A, that of the W protein remained constant, while relative amounts of the two basic proteins increased. Proteolipid protein concentration also increased as a percentage of the total protein from fraction D to B, but the uppermost fraction. A, had a markedly lower amount than fraction B. At 1 h after intracranial injection of [3H]leucine, the specific radioactivity of the basic and proteolipid proteins decreased from fraction D to B, with proteolipid protein in fraction A again anomalous (specific radioactivity higher than expected). These results are consistent with (but do not prove) a precursor-product relationship for individual proteins from denser to lighter subfractions, with the exception of myelin subfraction A. Experiments involving time staggered injections of a [14C] and later a [3H] labelled amino acid gave data which demonstrated that the W and basic proteins were added simultaneously (or with delays of much less than 20 min) to all of the subfractions, while proteolipid protein was added sequentially, from lower to upper fractions on the gradient. This double isotope technique also confirmed our previous observations that proteolipid protein shows a lag in entry into myelin compared to basic protein.
Arachidonic acid release by cPLA2 may be causally related to NO‐induced apoptosis in vascular smooth muscle cells

Apoptosis has been shown to occur in vascular smooth muscle cells during the development of atherosclerosis. In order to investigate the possible role of arachidonic acid during apoptosis in vascular smooth muscle, we induced apoptosis in cultured rat aortal smooth muscle cells (SMCs) by treatment with either UV (ultraviolet) radiation, tumor necrosis factor-alpha (TNF-alpha) or NO donor drugs (sodium nitroprusside, or S-nitroso-N-acetyl-D-penicillamine, SNAP). Apoptosis was detected by either DNA fragmentation analysis or by TUNEL analysis. UV radiation, TNF-alpha and NO were observed to stimulate apoptosis in the cells as well as to stimulate arachidonate release from the cells. NO also increased levels of cPLA2 in the cells, which is an enzyme that is frequently activated in cells that release arachidonate. These agents stimulated arachidonate release somewhat earlier than they stimulated apoptosis in the cells. The inhibition of cPLA2 by arachidonyl trifluoromethyl ketone (AACOCF3) also led to the inhibition of arachidonate release from the cells as well as the inhibition of nitroprusside stimulated apoptosis. Arachidonic acid itself could induce apoptosis in the cultured cells. These observations provide evidence that arachidonate may be involved in apoptosis in vascular smooth muscle.
Right Ventricle–to–Pulmonary Artery Conduit Versus Blalock-Taussig Shunt: A Hemodynamic Comparison

Background A comprehensive assessment of 48 hour postoperative hemodynamics in neonates randomized to the right ventricle–to–pulmonary artery (RV-PA) conduit or modified Blalock-Taussig (BT) shunt for stage 1 palliation of hypoplastic left heart syndrome was performed to determine the potential benefits of the modified technique. Methods Randomization to either RV-PA conduit or BT shunt was stratified by surgeon and the presence of aortic atresia. The designated procedure was performed by using hypothermic cardiopulmonary bypass with phenoxybenzamine, continuous cerebral perfusion, pH-stat blood gas management, and continuous postoperative venous oximetry. Differences between treatments were analyzed by time-series generalized least-squares regression, χ 2 tests, two-way repeated measures analysis of variance, and the Levene variance ratio test for variability in parameters, as appropriate. Results All patients underwent the procedure to which they were randomized. There were no differences in age, weight, deep hypothermic circulatory arrest, or cardiopulmonary bypass times between patients receiving the BT shunt (n = 8) or the RV-PA conduit (n = 9). There was one early and one late death in the RV-PA conduit group, and one interstage death in the BT shunt group. Other than diastolic blood pressure (39 mm Hg in BT shunt versus 46 mm Hg in RV-PA conduit, p p Conclusions In this randomized prospective study, no hemodynamic benefits of the RV-PA modification for stage 1 palliation of hypoplastic left heart syndrome were found. Pulmonary blood flow was more variable, and the diastolic blood pressure was higher. These findings did not influence indicators of systemic oxygen delivery with our afterload reduction strategy.
Horner’s syndrome and dissection of the internal carotid artery after chiropractic manipulation of the neck

PURPOSE: To report a case of Horner's syndrome and dissection of the internal carotid artery after chiropractic manipulation of the neck. METHODS: Case report. A 44-year-old woman with no prior ocular or vascular history presented with severe right-sided head and neck pain, ptosis, and miosis following chiropractic treatment for a strained right shoulder muscle. RESULTS: Magnetic resonance angiography of the neck and brain revealed a dissection of the right internal carotid artery as well as a suggestion of subtle dissection in the right vertebral artery. No significant brain abnormalities were noted on magnetic resonance imaging. Pharmacological testing was consistent with preganglionic oculosympathetic damage. CONCLUSION: Acute, painful Horner's syndrome as a manifestation of vascular dissection may be associated with chiropractic manipulation of the neck.
WT1-mediated Transcriptional Activation Is Inhibited by Dominant Negative Mutant Proteins

Abstract The WT1 tumor suppressor gene encodes four isoforms of a zinc finger transcription factor with both activation and repression functions which are dependent upon promoter architecture. Using a simple HSV- tk promoter containing 5′-Egr-1/WT1-binding sites, we found that WT1 isoforms (A) and (B) strongly activated transcription. WT1(A) and (B) bound equally well to the Egr-1/WT1-binding site, but WT1(B), which contains a 17 amino acid insertion compared to WT1(A), was a consistently stronger activator of transcription than WT1(A). Transcriptional activation by wild-type WT1 was inhibited by coexpression of WT(PM) or WT(AR), genetically defined dominant negative alleles of WT1. In vitro, as well as in the yeast two-hybrid system, WT1 protein associated with itself and with dominant negative mutant proteins. The major domain required for self-association and inhibition of transcriptional activation mapped to the first 182 amino acids of WT1. Dominant negative WT1 alleles may play a role in tumorigenesis by associating with wild-type WT1 proteins and decreasing their transcriptional activity.
A nonlinear regression analysis for estimating low-temperature vapor pressures and enthalpies of vaporization applied to refrigerants

A new method is presented to extrapolate experimental vapor pressures down to the triple Point. The method involves a nonlinear regression analysis based on the Clausius Clapeyron equation and a simple relation for the enthalpy of vaporization Triple-point pressures and vapor pressures up to 0.1 0.2 MPa are estimated for R125, R32, R143a, R134a, R152a, R123, R124, and ammonia; they generally agree with available experimental data within their uncertainty, Equations for the enthalpy of vaporization which describe this property fairly well at low temperatures are obtained as a byproduct.
Coordination of biogenic amines with synaptosomal and vesicular metal ions: equilibrium and spectral studies in model systems.

Abstract Thermodynamic equilibrium studies using model systems were carried out on the nature and extent of coordination of twelve different biogenic amines and adenosine-5′-triphosphate (ATP) with the bivalent metal ions, viz., Ca 2+ and Zn 2+ , which occur in the subcellular fractions of the brain, at 25.0 ± 0.1°C and at an ionic strength of 1.0 (KNO 3 ). In the combined presence of the individual monoamines and ATP the metal ions were predominantly coordinated by ATP in the pH range 3.0 to 6.5 with binding constants (log K ML ) of 2.84 ± 0.06 and 3.19 ± 0.39 for the Ca 2+ and Zn 2+ chelates, respectively. Each of the monoamines coordinated with the metal-ATP chelate above pH 6. The stabilities of the chelates of some of the amines with Ca 2+ -ATP (1:1) system were NE, 2.33 ± 0.33; AA, 2.24 ± 0.19; OA, 1.94 ± 0.29; NMeN, 1.60 ± 0.22; DA, 2.14 ± 0.09. Values for the Zn 2+ -ATP-amine systems were: NE, 8.35 ± 0.26; OA, 4.53 ± 0.07; DA, 10.05 ± 0.39. Absorption spectral studies were carried out in order to examine the nature of coordination of NE, DA, TA, and AA with Cu 2+ , Fe 2+ , and Mg 2+ ions in the combined presence of ATP. Results of the spectral studies taken together with the (thermodynamic) equilibrium data have indicated that in the pH range of biological interest, the catechol amines (NE and DA) and ATP are both coordinated to the “synaptosomal and vesicular” metal ions. The results further indicated that both the pyrocatechol and the ethanolamine groups of NE might be involved in the coordination of Cu 2+ . However, the interaction of the ethanolamine group of the NE molecule with the rest of the metal ions was not indicated.
Power System Stability Studies by the Method of Liapunov: I - State Space Approach to Synchronous Machine Modeling

This paper records the development of a synchronous machine model in the mathematical form required by most modem automatic control theorems. The model is based on a new expression for the constraint imposed on the machine by a general balanced 3-phase tee-form transmission system consisting of a step-up transformer, a shunt load, and a transmission line terminating at a bus of known voltage.
Human diploid fibroblasts (HDF) can induce DNA synthesis in cycling HDF but not in quiescent HDF or senescent HDF

HeLa cells in S phase induce DNA synthesis in cycling cells, serum-deprived quiescent cells, and non-replicative senescent cells following cell fusion. In contrast normal human diploid fibroblasts (HDF) do not induce DNA synthesis in either quiescent cells or senescent cells. Instead, the replicative HDF nuclei are inhibited from entering S phase in heterokaryons formed with these two types of non-replicative cells. These differences in the inducing capabilities of normal HDF and HeLa cells raise the question whether normal HDF in S phase can induce DNA synthesis in cycling cells. This paper demonstrates that young HDF in S phase can induce DNA synthesis in cycling HDF. Thus, the hypothesis that initiation of DNA synthesis in cycling cells is positively controlled by inducer molecules appears to be valid for normal HDF as well as for transformed cells such as HeLa.
Right-to-know training of workers with IQ less than 70: a pilot study

Chemical emergencies occur frequently in the workplace. Laws and regulations have been enacted to reduce the risk of injuries to workers, including workers with an IQ less than 70. These regulations require employers to educate their workers about the nature and hazards of toxic substances in the workplace, about methods to reduce exposure, and about appropriate responses in case of an accident or an emergency. From May to August 1996, a project examined the responses of 58 Goodwill Industries employees before and after their attendance at a mandatory "Right-to-Know" training program. Responses to five questions relating to the safe use of chemicals were analyzed. A combination of quantitative and qualitative evaluations determined that for the 28 subjects with IQ or = 70. The findings of this pilot study show the need to develop training programs tailored to meet the needs and conditions of workers with IQ < 70.
Diabetes mellitus and antipsychotic treatment in the United Kingdom.

Abstract Objective Treatment-emergent diabetes has been reported during exposure to conventional and atypical antipsychotics. This retrospective cohort study explored the UK General Practice Research Database (GPRD) to determine hazard ratios of diabetes for patients prescribed antipsychotics. Methods A Cox proportional hazard regression model using age, gender, and obesity (BMI > 30 kg/m 2 ) was used to determine the hazard ratio (HR) of diabetes development in conventional antipsychotic ( N = 59,089), atypical antipsychotic ( N = 9053), individual antipsychotic, and general patient population cohorts ( N = 1,491,548). Results Compared with the general GPRD patient population, patients exposed to conventional or atypical antipsychotics had a higher risk of developing diabetes (atypical antipsychotic cohort: HR = 2.9, CI = 2.0–4.4; and conventional antipsychotic cohort: HR = 1.9, CI = 1.6–2.3). The risk of developing diabetes during thioridazine, risperidone, or olanzapine treatment was significantly higher compared with the general GPRD patient population. Conclusion Consistent with other epidemiology studies, this study supports an increased risk of developing diabetes during treatment with antipsychotics.
Electrical conductivities of the Ag6PS5X and the Cu6PSe5X (X=Br, I) argyrodites

Abstract The Ag 6 PS 5 Br and Ag 6 PS 5 I argyrodites crystallize in a face-centered-cubic lattice at room temperature. Both compounds exhibit purely Arrhenius behavior throughout the temperature range 150–400 K with similar activation energies of about 0.23 eV. Cu 6 PSe 5 Br and Cu 6 PSe 5 I also crystallize in a face-centered-cubic structure at room temperature. Cu 6 PSe 5 Br exhibits a distinctive anomaly in electrical conductivity near 286 K while Cu 6 PSe 5 I undergoes a first-order electrical phase transition near 265 K. Their activation energies above room temperature are 0.13 and 0.30 eV, respectively.
PVDF microbelts for harvesting energy from respiration

In this paper, we report a technique that uses piezoelectric polyvinylidene fluoride (PVDF) microbelts to convert the energy from low-speed air flow to electricity via their resonant oscillation. The micrometre thick PVDF thin films were fabricated by a top-down reactive ion etching process, where the thickness was controlled by etching time and the piezoelectric phase was well preserved. The thickness, air flow speed and electrical output relationship was predicted theoretically and characterized experimentally. The PVDF microbelts were able to generate sufficient electrical energy from low speed air flow for the sustained operation of small electronic devices. Their capability for harvesting energy from simulated respiration was also demonstrated.
Spectrum and width of mode-locked laser pulses

An analytical theory is given of the spectrum of the pulses generated by a ring laser that is mode locked by a synchronously modulated absorber. A steady-state solution is defined by requiring that, in a round trip, the joint effect of the active medium and the modulated absorber leave the pulses unchanged. The resulting integral equation is solved approximately, and the frequency spectrum of the pulses is obtained in closed form. Although the spectrum cannot be transformed analytically to obtain the pulse shape, the second moment of the shape, which gives a measure of the width, is found. The spectrum and width are found to depend on the curvature of the modulator waveform, near its maximum transmission, and on the gain and bandwidth of the active medium, which is assumed to have a Lorentzian line shape.
Cyclic protein-2, a secretory product of rat Sertoli cells, is the proenzyme form of cathepsin L.

Previous studies demonstrated that secretion of Cyclic Protein-2 (CP-2) by mature rat Sertoli cells increased 30-fold from stage II to stages VI-VII of the cycle of the seminiferous epithelium and suggested that this protein was concentrated around compacted spermatids. Analysis of other organs revealed that CP-2 was also detectable in the epithelium of the proximal kidney tubule and in neurons originating from the supraoptic and paraventricular nuclei of the hypothalamus. We now have isolated a partial 1.8-kilobase (kb) cDNA for CP-2 mRNA, and sequence analysis revealed that CP-2 was the proenzyme form of the cysteine protease cathepsin L; this was corroborated by immunoprecipitation of CP-2 by anticathepsin L immunoglobulin G and by enzymatic analysis of purified CP-2. Northern analysis of testis mRNA revealed major (1.7 kb) and minor (2.2 kb) transcripts which differed in the length of their 3′-untranslated sequences. Low levels of CP-2/cathepsin L transcripts were detected in many organs, while high l...
Gas microbubbles: an assessment of their significance to light scattering in quiescent seas

In this study the main features of the light scattering by an air bubble in water are summarized using Mie scattering calculations. The possible contribution of persistent populations of microbubbles to total scattering and backscattering coefficients of sea water in quiescent seas is evaluated. This assessment is made assuming various concentrations and size distributions of bubbles larger than 20 micrometers in diameter, which are representative of surface waters during nearly calm sea conditions. It appears that the contribution of these bubbles to the total scattering and backscattering coefficients cannot be neglected in some oceanic situations. This contribution varies between a fraction of 1% to several percent, and might possibly be as high as a dozen or so percent. The major uncertainty in these calculations is the lack of simultaneous measurements of bubbles and light scattering. In addition, because no in situ data about bubbles less than 20 micrometers in size are available, these small bubbles are not taken into account in the present assessment.© (1994) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Evaluation of matrix-assisted laser desorption ionization mass spectrometry for studying the sec-butyllithium and N-butyllithium initiated ring-opening polymerization of hexamethylcyclotrisiloxane (D3)

Matrix assisted laser desorption ionization (MALDI) was used to study the organolithium initiated ring-opening polymerization of hexamethylcyclotrisiloxane (D3) in a mixed solvent system. The mass spectral peak intensities were monitored to determine the effects of polymerization time, initiator concentration, and reaction temperature on the formation of the mono, di, and trisiloxanolate initiator species and the extent of chain redistribution. The three initiator species were formed by reacting n-butyllithium and sec-butyllithium with D3 in nonpolar solvent. The mass spectral results showed that sec-butyllithium and n-butyllithium form different populations of initiator species under the same conditions and that the measured mass spectral peak intensities do not accurately represent the population of siloxanolate initiator species prior to propagation. The changes in peak intensities were attributed to chain redistribution.
Behavior therapy for anorexia nervosa: taking a second look.

Over the past 40 years, clinical treatment protocols for anorexia nervosa have evolved from being primarily behavioral-based to cognitive-based. Although treatment methods for anorexia nervosa have changed, there is little research to support the use of any particular method over another. The scarce research data that exist on the long-term outcomes of both behaviorally and cognitively-based treatment methods indicate poor prognosis for a high percentage of patients. Behavioral treatment methods have significantly changed since their initial use in treating AN patients, but this method has not yet been re-explored as a treatment option. This article discusses previous problems with treating anorexia nervosa from a behavioral model and argues for a functional analysis behavioral approach toward treatment.
Treatment of two insecticides in an electrochemical Fenton system

Abstract The ability of an electrochemical Fenton system to degrade the organophosphorous insecticides malathion and methyl parathion was studied. A combination of hydrogen peroxide and electrochemically‐generated iron was found to be successful in degrading the two insecticides, and optimization of the system was pursued. Augmentation with near UV light at an intensity of 1.67xl017 quanta/sec and centered at a wavelength of 370 nm improved the degradation of malathion at low iron concentrations but did not affect other treatments. Adding the hydrogen peroxide slowly over the course of treatment rather than all at once at the beginning of each treatment did, however, greatly improve the system. Removal efficiencies of 98.0% or greater were achieved for both pesticides.
Sites and mechanisms of basic narcotic receptor function based on current research.

Within the past decade, progress in opiate pharmacology has been phenomenal and has stimulated widespread interest. Several potent endogenous peptides with morphine-like activity were isolated and their structures were established. Opioid receptors in the brain were localized and characterized. Plausible hypotheses to explain the mechanism of action of the narcotic analgetics have been proposed. Antagonist-agonists that are potent analgesics with low addiction liability were introduced for clinical application. Epidural administration of morphine and its surrogates to reduce side effects and prolong drug action is gaining increasing popularity. Extensive research is ongoing concerning the use of opioids in the treatment of shock and the mental states. Some of these advances will be discussed.
Examination and evaluation of germination and protonemal development for Onclea sensibilis fern spores treated with aflatoxin B1

Experiments were designed to test the effects of aflatoxin B1 (AFB1) on germination and subsequent development of the gametophytes of the sensitive fern Onoclea sensibilis. AFB1 concentrations used were 0, 2.5, 5.0, 7.5, 10.0 and 12.5 μM.
Correlation of early orientational ordering of engineered λ6–85 structure with kinetics and thermodynamics

Abstract Experimental and computational Φ-value analysis of two-state helical proteins has shown that definite interactions among helix-forming segments build up in the transition state ensemble, but this type of analysis is not applicable to downhill folders. Here, we ask whether orientational ordering of helix-forming segments occurs early on during folding of a downhill λ 6–85 mutant, and how much it correlates with the thermodynamics and kinetics of various λ 6–85 mutants that do have folding barriers. From a grand total of 5 μs of implicit solvent replica-exchange molecular dynamics, we conclude that under folding conditions segments 1 and 4 form more helical structure and orient correctly relative to the native structure more often than do segments 2 and 3. Helices 1 and 2 retain the most residual structure and orientation at high temperatures. This is further supported by experimental data showing that perturbations in helices 1 and 4 of this well-designed folder affect folding kinetics and stability more sensitively than elsewhere in the protein, and that the helix 1–2 only bundle retains a cooperative melting transition and helical CD spectrum. The correct orientational propensity of helices 1 and 4 at low temperature is in agreement with the work by Takada, Portman and Wolynes proposing initial structure formation during folding in helices 1 and 4 of the wild-type λ 6–85 protein, a two-state folder. Thus, the absence of a large barrier in the downhill mutant does not fundamentally alter the steps the wild-type protein takes to fold.
Field studies of avian nocturnal migratory orientation II. Experimental manipulation of orientation in white-throated sparrows (Zonotrichia albicollis) released aloft

Abstract Migrant white-throated sparrows (Zonotrichia albicollis) were released from boxes carried aloft by balloon and tracked with radar. All birds were released on clear nights when winds were light and opposed to the normal migration direction for the season. Birds were treated in one of two ways: Lens birds were fitted with frosted lenses prior to release; No Lens birds were released without lenses. No Lens birds that engaged in straight and level flight generally headed in the predicted migratory direction and as a group were not oriented with respect to wind direction. Lens birds did not head in the predicted migratory direction, but instead oriented downwind. This orientation behaviour is consistent with the relationship of orientation cues inferred from the field observations described in part I of this paper. The data show that flying birds deprived of all detailed form vision can determine wind direction.
Effects of Root Morphology and Hg Concentration in the Soil on Uptake by Terrestrial Vascular Plants

Vascular plant tissues of various species growing on flood plain soils along the South River at Waynesboro, VA. have previously been shown to contain Hg. These soils characteristically contain 10–20 µg Hg g−1. In the field, root/rhizome Hg content in Asclepias syriaca and Solidago sp. ranged from undetectable amounts at low Hg control sites to 1.96 µg Hg gdw−1 at contaminated sites, with the association being inversely related to subterranean organ size. Within each size class, tissue Hg was directly related to soil Hg concentration. The relationship of subterranean organ size and enhanced Hg association was further substantiated by high levels of Hg in the fibrous root systems of grasses grown under greenhouse conditions.
Pertussis in a previously immunized child with human immunodeficiency virus infection

The management of children with human immunodeficiency virus infection in whom changes in pulmonary status develop can be complex. They are susceptible to a broad range of infections, and the clinician must be aware of the multiple etiologic possibilities and appropriate diagnostic tests. This report presents a potential pathogen that should be added to the list of organisms that can cause gram-negative pneumonia in children with HIV infection and highlights a diagnostic pitfall.
Effect of phenobarbital administration to rats on the level of the in vitro synthesis of cytochrome P-450 directed by total rat liver RNA

Abstract Total liver RNA has been isolated from male rats at different time points subsequent to a single injection of phenobarbital, and the level of cytochrome P-450 synthesis directed by these RNA preparations in a cell-free translation system has been determined. It is observed that the maximum in vitro synthesis of cytochrome P-450 occurs at 16 hours (3-fold above uninduced level) which is approximately 30 hours prior to the maximum induction of spectrophotometrically detectable cytochrome P-450 measured in liver homogenates. Thus, while cytochrome P-450 mRNA is involved in the induction process, its synthesis does not appear to be rate limiting. In addition, phenobarbital induced cytochrome P-450 is not synthesized in vitro in a form larger than that isolated from endoplasmic reticulum, but rather is also found to have a molecular weight of 50,000.
An electromicroscopic study of extended single polynucleotide chains.

Tobacco mosaic virus RNA molecules were deposited as extended, oriented, single polynucleotide chains on carbon films for electron microscopy. This was accomplished by heating their solution to 45°C in the presence of formaldehyde, and then cooling rapidly to obtain a non-hydrogen bonded, random coil configuration at room temperature. Carbon films mounted on electron microscope grids were then streaked across the surface of the solution. The length distribution indicates that most of the molecules were either unbroken or suffered only one break. From the known molecular weight the base spacing is calculated to be between 6 and 7 A. This is sufficient for an electron microscopic determination of their sequence using present instruments and adequately small nucleotide specific markers. The results suggest that the molecular weights of single polynucleotide chains can be determined by direct measurement of their length.
Controlled cell proliferation on an electrochemically engineered collagen scaffold

Therapies for corneal disease and injury often rely on artificial implants, but integrating cells into synthetic corneal materials remains a significant challenge. The electrochemically formed collagen-based matrix presented here is non-toxic to cells and controls the proliferation in the corneal fibroblasts seeded onto it. Histology and biomolecular studies show a behavior similar to corneal stromal cells in a native corneal environment. Not only is this result an important first step toward developing a more realistic, multi-component artificial cornea, but it also opens possibilities for using this matrix to control and contain the growth of cells in engineered tissues.
Acidic ZSM-5 zeolite-coated long period fiber grating for optical sensing of ammonia

A ZSM-5 zeolite thin film with Si/Al ratio of about 23 has been grown on a long period fiber grating (LPFG) for optical gas sensing by monitoring its resonance wavelength (λR) shift caused by molecular sorption into the zeolite cavity. The sensing selectivity, sensitivity and speed of response of the zeolite-coated LPFG (Z-LPFG) are determined by the adsorption equilibria and transport properties of the analyte molecules in the zeolite pores. The ZSM-5 zeolite was modified through ammonium ion exchange and subsequent calcination to form acidic ZSM-5 (H-ZSM-5). The surface acidified Z-LPFG (HZ-LPFG) achieved dramatically improved sensitivity and selectivity for detecting ammonia gas. Also, increasing operation temperature improves sensing selectivity for the strongly adsorbing ammonia over weakly adsorbing gases and enhances response speed but compromises detection sensitivity due to reduced amount of adsorption for ammonia.
The Function of Ethnicity, Income Level, and Menstrual Taboos in Postmenarcheal Adolescents’ Understanding of Menarche and Menstruation

The purpose of this study was to examine differences in knowledge about menstruation, feelings of preparation for menarche, and menstrual attitudes of early adolescent girls from different ethnic groups and income levels. An interaction between ethnicity and income level was also investigated. Participants were 165 postmenarcheal adolescent girls’ (ages 11–15) from Pittsburgh, Pennsylvania, USA, who were categorized into four groups: higher income European Americans, lower income European Americans, higher income African Americans, and lower income African Americans. It was predicted that African Americans, lower income participants, and lower income African Americans would score lower on a menstrual knowledge test, report feeling less prepared for menarche, and report more negative menstrual attitudes (i.e., fewer positive feelings about menstruation, more negative feelings about menstruation, and less openness toward menstruation) than European Americans, higher income participants, and any other income level and ethnicity grouping. Not all hypotheses were fully supported. Participants’ lacked accurate menstrual knowledge and felt unprepared for menarche, but menstrual attitudes were ambivalent. Ethnicity and income level alone did not play a substantial role in girls’ understanding of menarche and menstruation; however, they did interact. Overall, higher income European Americans fared better than the other participants. Theories and research regarding girls’ understanding of menarche and menstruation must take sociocultural factors into account.
Expression of rat, renal NHE2 and NHE3 during postnatal developmental

Abstract The current studies were designed to characterize the expression of sodium–hydrogen exchangers NHE2 and NHE3 during rat, renal ontogeny. NHE2 mRNA and immunoreactive protein were more highly expressed at 2 and 3 weeks of age, with declining levels into adulthood. In situ hybridization of NHE2 mRNA localized the message to the renal inner cortex and outer medullary regions and suggested higher mRNA levels in suckling animals as compared to adults. Immunohistochemical analysis of rat kidney with the NHE2 antiserum showed specific staining of the distal convoluted tubules. In contrast, NHE3 mRNA expression was lowest in 2-week animals and higher in older rats, while NHE3 immunoreactive protein showed constant expression levels during development. Additionally uptake experiments utilizing HOE694 showed no change in NHE2 or NHE3 functional protein expression in 2-week-old rats versus adults. We conclude that the developmental increase in NHE2 mRNA and immunoreactive protein expression cannot be detected by functional assays, which suggests that NHE2 does not play a role in sodium absorption by the renal tubules (as has been previously suggested). Additionally, molecular changes seen in NHE3 mRNA expression do not affect functional protein activity, suggesting increased mRNA translational efficiency or protein stability in suckling rats.
The Effect of Antihistamines on the Pigments of Green Protista.

SUMMARY. A preliminary survey of the influence of a number of antihistamines on growth of several protozoa indicated that not only growth but also pigment formation in green forms was inhibited. Subsequently, it was demonstrated that molar concentrations of the drugs of less than 1 times 10−3 caused chlorosis of cultures of Euglena gracilis var. bacillaris, Chlamydomonas pseudococcum, and Chlorella vulgaris. With the aid of one of the antihistamines, Pyribenzamine (CIBA), a permanently colorless culture of Euglena was obtained. This culture has been maintained in the chlorotic state in antihistamine-free medium through eighteen serial transfers in constant light. Comparative spectro-photometric studies were made of the pigments extracted from this new euglenid strain with those from normal green, dark-grown and streptomycin-bleached euglenas. Although the dark-etiolated forms retained small amounts of chlorophylls, neither of the drug-bleached cultures showed evidence of these pigments. Quantitatively, the carotenoid picture in dark-bleached and streptomycin-grown organisms was similar, but these pigments were greatly reduced in the Pyribenzamine-treated strain. Further studies on the identity of the carotenoids in the new euglenid are in progress.
Sequence and structure space of RNA-binding peptides.

Studies of RNA-binding peptides, and recent combinatorial library experiments in particular, have demonstrated that diverse peptide sequences and structures can be used to recognize specific RNA sites. The identification of large numbers of sequences capable of binding to a particular site has provided extensive phylogenetic information used to deduce basic principles of recognition. The high frequency at which RNA-binding peptides are found in large sequence libraries suggests plausible routes to evolve sequence-specific binders, facilitating the design of new binding molecules and perhaps reflecting characteristics of natural evolution.
The New Science of Sex Difference

While scientists across the academy have abandoned the nature/nurture dichotomy, evidence for the influences of society on our biology is greater than ever. This article reviews new developments in the biological sciences – in the sub-fields of genetics, hormones, and neuroscience – with special attention to the implications for sociologists interested in gender. The article closes with an argument that embracing these developments has both theoretical and methodological promise and can enhance rather than harm research and activism regarding gender equality and other social hierarchies.
Tracking back references in a write-anywhere file system

Many file systems reorganize data on disk, for example to defragment storage, shrink volumes, or migrate data between different classes of storage. Advanced file system features such as snapshots, writable clones, and deduplication make these tasks complicated, as moving a single block may require finding and updating dozens, or even hundreds, of pointers to it.We present Backlog, an efficient implementation of explicit back references, to address this problem. Back references are file system meta-data that map physical block numbers to the data objects that use them. We show that by using LSM-Trees and exploiting the write-anywhere behavior of modern file systems such as NetApp® WAFL® or btrfs, we can maintain back reference meta-data with minimal overhead (one extra disk I/O per 102 block operations) and provide excellent query performance for the common case of queries covering ranges of physically adjacent blocks.