cssi/SciSciGPT-SciSciNet huggingface dataset:
Structure-reactivity relationships for beta-galactosidase (Escherichia coli, lac Z). 3. Evidence that Glu-461 participates in Brønsted acid-base catalysis of beta-D-galactopyranosyl group transfer.

Experiments are reported to determine the role of Glu-461 in the β-d-galactopyranosyl group transfer reaction catalyzed by β-galactosidase. E461G β-galactosidase catalyzes the hydrolysis of 4-nitrophenyl β-d-galactopyranoside through a galactosyl−enzyme intermediate that shows a high reactivity toward the anionic nucleophile azide ion, but no detectable reactivity toward the neutral nucleophile trifluoroethanol. By contrast, the galactosylated wild type enzyme is reactive toward trifluoroethanol but not anions. The change in specificity observed for the E461G mutant can be rationalized by a mechanism in which Glu-461 participates in general acid−base catalysis at the leaving group/nucleophile. The observed low activity of E461G β-galactosidase for hydrolysis of 2,2,2-trifluoroethyl β-d-galactopyranoside is due entirely to a wild type enzyme contaminant in our preparation of the mutant enzyme, and the mutant enzyme itself has essentially no catalytic activity for cleavage of this substrate. The substitutio...
Experimental study of single-electron capture by low-energy Neq+ recoil ions (q=3-6) from He, Ne and Ar using translational energy spectroscopy

The translational energy spectroscopy technique has been used to study single-electron capture processes for collisions of slow Neq+ ions (q=3-6, where q is the projectile charge state), produced in a recoil ion source, with He, Ne and Ar at laboratory impact energies between 100 and 600 eV and scattering angles between 0 degrees and 6 degrees . The measurements show that the dominant reaction channels are due to capture into excited states of the projectile products and show a dependence on scattering angle. There is clear evidence of the presence of the first and second metastable states in the incident Ne3+ ion beam. A reasonable description of the dominant final states is obtained in terms of the reaction windows, which are calculated using the single-crossing Landau-Zener model. The measured differential cross sections show that the projectile products are distributed with maximum intensity near a scattering angle theta c which corresponds to capture at an impact parameter equal to the crossing radius.
Multiple relationships: Does the new ethics code answer the right questions?

The new "Ethical Principles of Psychologists and Code of Conduct" (American Psychological Association, 1992) presented expanded attempts to clarify the ethical issues regarding multiple relationships and to provide useful guidance for psychologists. This article proposes that the new code fails to address adequately two basic questions necessary to provide psychologists with clear guidance: (a) What are multiple relationships? and (b) When do multiple relationships constitute unethical conduct? The article offers a definition of multiple relationships and identifies several dynamics operating within a professional relationship that are likely to be adversely affected by the imposition of a secondary relationship. Unethical multiple relationships are defined. Finally, the article suggests additions to the new code that would enhance its utility for psychologists.
The synthesis of Sm/sub 2/(Co,Fe,Zr)/sub 17/ high energy product, 16 to 30 MGOe, thick sputtered films

Sputtering methods have been developed that allow the synthesis of Sm/sub 2/(Co,Fe,Zr)/sub 17/-type films with thicknesses between 20 to 100 mu m that exhibit an in-plane static energy product on the order of 20 MGOe. To achieve the energy product range of interest it is necessary that the films exhibit crystallographic texturing such that the crystallite c-axes preferentially lie in the plane of the substrate. This requires that the films be directly crystallized onto heated substrates. It has been found necessary to precoat the sapphire substrates with a boundary layer of oxidized Al-Al/sub 2/O/sub 3/ to allow the films to be strongly adherent to the substrate. Films have been made for a very narrow range of sputtering conditions that exhibit no X-ray reflections that correspond to the presence of crystallites with c-axes skewed out of the film plane. It is also necessary that the films be deposited so as to prevent the formation of a noticeable columnar growth pattern. The presence of such a columnar growth pattern introduces porosity that lowers the effective magnetization value. Such high-energy product films are potentially useful for the fabrication of small-scale integrated electromagnetic components. >
Anatomy of the naso- and oropharynx

Abstract Successful airway management requires an understanding of the upper and lower airway structures and functions. The nose and pharynx are important structures in the upper airway, providing: air quality control; protection of the lower airway; phonation and safe passage of food.
Managing Uncertainty During Collaborative Problem Solving in Elementary School Teams: The Role of Peer Influence in Robotics Engineering Activity

This study investigated how interaction with peers influenced the ways students managed uncertainty during collaborative problem solving in a 5th-grade class. The analysis focused on peer responses to individuals’ attempts to manage uncertainty they experienced while engaged in collaborative efforts to design, build, and program robots and achieve assignment objectives. Patterns of peer response were established through discourse analysis of work sessions for 5 teams engaged in 2 collaborative projects. Three socially supportive peer responses and 2 unsupportive peer responses were identified. Peer interaction was influential because students relied on supportive social response to enact most of their uncertainty management strategies. This study provides a useful theoretical contribution to understanding the roles of peer interaction in collaborative problem solving. Conceptualizing collaborative problem solving as a process of negotiating uncertainties can help instructional designers shape tasks and re...
Purification and characterisation of α-l-fucosidase from human placenta pH-dependent changes in molecular size

Abstract α- l -Fucosidase has been purified 12 000 fold from human placenta. The enzyme is a glycoprotein containing, by weight: 0.9% galactose; 1.9% mannose, 1.9% N -acetylglucosamine and 1.9% N -acetylneuraminic acid. Polyacrylamide gel electrophoresis in the presence of sodium dodecyl sulphate separated proteins with molecular weights of 55 000, 51 400 and 25 000. Resolution of the two larger protein bands varied with the gel system and these proteins may differ only in carbohydrate content. Gel filtration of the purified enzyme failed to separate the three proteins. Treatment with the cross-linking reagent dimethyl suberimidate prior to electrophoresis, resulted in a diminution of the original protein bands and the formation of oligomers with molecular weights of 80 000, 100 000, 130 000, and 144 000. These results suggest that the heavy (55 000 and 51 400) and light (25 000) proteins are structurally associated. The molecular weight of the native enzyme, measured by gel filtration, was dependent on the pH of the eluting buffer. At pH 5.0 or 6.0 a catalytically active peak was observed, with a molecular weight of 305 000. At pH 7.5 this peak was completely absent and the enzyme eluted as an asymmetrical peak with an apparent molecular weight of about 60 000. The reduction in apparent molecular weight at pH 7.5 was reversible by dialysis of isolated fractions at pH 6.0. In agreement with these findings the sedimentation coefficient was 8.5 S at pH 5.0 but only 3.6 S at pH 7.5. The results can be accounted for by the existence of a pH-dependent equilibrium between aggregated and dissociated forms of the enzyme or by pH-dependent conformational changes.
Selecting the best triage rule for patients hospitalized with chest pain

Purpose During an observational study, we investigated the potential benefits and risks of the use of admission and early transfer triage rules in 498 patients hospitalized with chest pain. Patients and methods Appropriateness of triage decisions was measured using explicit and implicit judgments. Results Application of an admission triage rule (partially based on the Brush electrocardiographic criteria) would have increased coronary care unit (CCU) admissions by 3%, whereas application of a triage rule 24 hours after admission would have reduced bed utilization by 860 intermediate care and 82 CCU bed-days per year when compared with actual patient triage. Although 9.5% of patients who underwent triage according to the early transfer triage rule would have experienced a minor complication after transfer, the medical care of none would have been adversely affected. Conclusion Our results show that application of a triage rule 24 hours after admission may have the potential to shorten length of stay in the CCU and intermediate care unit without significantly compromising patient care. However, use of the admission triage rule would have increased CCU bed utilization. The failure of the admission triage rule to improve bed utilization illustrates the potential hazards of ignoring patient complications, interventions, and co-morbidity when predicting the efficacy of a triage rule.
In Defense of Women's Rights: A Rhetorical Analysis of Judicial Dissent

This article examines Justice Ruth Bader Ginsburg's dissenting opinion in Gonzales v. Carhart to argue that her feminist jurisprudence challenges the rhetorical genre of judicial opinion. Ginsburg's dissent undermines the rhetorical commitments to neutrality, abstraction, and universality that overwhelmingly shape the voice of the law. Instead, Ginsburg's rhetoric advances a more promising field of argument for advocates of reproductive choice and shifts the language of the law to legitimate voices, experiences, and rights of groups traditionally excluded by the rhetoric of the law.
Lateral Deformation of Diffusion Couples

Abstract A model is used to describe the shape change of a binary diffusion couple when the diffusivities of the two species differ. The classical uniaxial Kirkendall shift is obtained only if the displacement is constrained to be in the diffusion direction. For traction-free conditions at the external surfaces of a diffusion couple, a more general displacement field is obtained that accounts for the lateral shape change data of Voigt and Ruth [Journal of Physics-Condensed Matter 7 (1995) 2655–2666]. The model employs an isotropic stress-free strain rate and equal and constant partial molar volumes. In this case the displacement field is shown to be independent of the various elastic/plastic moduli. Depending on the lateral dimension of the diffusion couple, the displacement in the diffusion direction can be reduced by up to a factor of three compared to the case of a pure uniaxial displacement.
iGibbs: Improving Gibbs motif sampler for proteins by sequence clustering and iterative pattern sampling

The motif prediction problem is to predict short, conserved subsequences that are part of a family of sequences, and it is a very important biological problem. Gibbs is one of the first successful motif algorithms and it runs very fast compared with other algorithms, and its search behavior is based on the well-studied Gibbs random sampling. However, motif prediction is a very difficult problem and Gibbs may not predict true motifs in some cases. Thus, the authors explored a possibility of improving the prediction accuracy of Gibbs while retaining its fast runtime performance. In this paper, the authors considered Gibbs only for proteins, not for DNA binding sites. The authors have developed iGibbs, an integrated motif search framework for proteins that employs two previous techniques of their own: one for guiding motif search by clustering sequences and another by pattern refinement. These two techniques are combined to a new double clustering approach to guiding motif search. The unique feature of their framework is that users do not have to specify the number of motifs to be predicted when motifs occur in different subsets of the input sequences since it automatically clusters input sequences into clusters and predict motifs from the clusters. Tests on the PROSITE database show that their framework improved the prediction accuracy of Gibbs significantly. Compared with more exhaustive search methods like MEME, iGibbs predicted motifs more accurately and runs one order of magnitude faster. Proteins 2007. © 2006 Wiley-Liss, Inc.
Wide-bandwidth frequency doubling with high conversion efficiency

We have designed and demonstrated two wide-bandwidth frequency doublers capable of second-harmonic generation over the entire 100-nm cavity optics bandwidth of a passively mode-locked Ti:Al2O3 laser with no loss in conversion efficiency across the bandwidth. The frequency doublers are passive, utilizing prism dispersion to achieve phase matching over this bandwidth, and exhibit minimal pulse broadening that is due to group-velocity dispersion. Our calculations show that the theoretical bandwidth of these dispersive frequency doublers extends across nearly the entire Ti:Al2O3 laser tuning range.
Phase field simulations of early stage structure formation during immersion precipitation of polymeric membranes in 2D and 3D

Abstract The immersion precipitation process makes most commercial polymeric membranes, which enjoy widespread use in water filtration and purification. In this work, a ternary Cahn–Hilliard formulation incorporating a Flory–Huggins homogeneous free energy function is used to simulate the liquid–liquid demixing stage of the immersion precipitation process, which determines much of the final morphology of membranes. Simulations start with a non-solvent/solvent/polymer ternary system with periodic boundary conditions and uniform initial conditions with small random fluctuations in two-dimensional (2D). Results in 2D demonstrate the effects of M i j (mobilities) and K i j (gradient penalty coefficients) on phase separation behavior. A two-layer polymer–solvent/non-solvent initial condition is then used to simulate actual membrane fabrication conditions. 2D and 3D simulation results show an asymmetric structure of membrane morphology, which strongly agrees with the experimental observation. Then this system is coupled with the Navier–Stokes equations to model hydrodynamics in two dimensions. The results show that fluid flow destabilizes the top layer of membrane.
Characterization of a Biomimetic Polymeric Lipid Bilayer by Phase Sensitive Neutron Reflectometry

Neutron reflectivity measurements were performed on a cell membrane mimic system, developed by Liu et al., consisting of a polyelectrolyte multilayer plus synthetic terpolymer plus a phospholipid layer (PE + TER + PC) assembly, at all of the intermediate steps in the assembly of the composite, to obtain neutron scattering length density depth profiles.1 The polyelectrolyte multilayer functions as a soft, water-containing “cushion” for the membrane mimic, formed by the synthetic terpolymer and the phospholipid layer. The assemblies were studied dry and in 92% humidity using a phase-sensitive neutron reflectometry technique. By use of two water conditions (D2O and H2O mixtures) on the PE + TER + PC assembly, the distribution of water in the layers was obtained. It was found that under 92% humidity conditions, the supported membrane mimic has 40% water content in the “cushion” polyelectrolyte multilayer and 10% water content in the terpolymer−phospholipid region. The overall thickness change, due to water up...
Microwave thermal imaging of scanned focused ultrasound heating: animal experiments

High intensity focused ultrasound (HIFU) uses focused ultrasound beams to ablate localized tumors noninvasively. Multiple clinical trials using HIFU treatment of liver, kidney, breast, pancreas and brain tumors have been conducted, while monitoring the temperature distribution with various imaging modalities such as MRI, CT and ultrasound. HIFU has achieved only minimal acceptance partially due to insufficient guidance from the limited temperature monitoring capability and availability. MR proton resonance frequency (PRF) shift thermometry is currently the most effective monitoring method; however, it is insensitive in temperature changes in fat, susceptible to motion artifacts, and is high cost. Exploiting the relationship between dielectric properties (i.e. permittivity and conductivity) and tissue temperature, in vivo dielectric property distributions of tissue during heating were reconstructed with our microwave tomographic imaging technology. Previous phantom studies have demonstrated sub-Celsius temperature accuracy and sub-centimeter spatial resolution in microwave thermal imaging. In this paper, initial animal experiments have been conducted to further investigate its potential. In vivo conductivity changes inside the piglet's liver due to focused ultrasound heating were observed in the microwave images with good correlation between conductivity changes and temperature.
Favorable Levels of All Major Cardiovascular Risk Factors at Younger Ages and High-Sensitivity C-Reactive Protein 39 Years Later -The Chicago Healthy Aging Study.

Objectives Examine associations of favorable levels of all cardiovascular disease (CVD) risk factors (RFs) [i.e., low risk (LR)] at younger ages with high sensitivity C-reactive protein (hs-CRP) at older ages.
Regulation of expression of the steroidogenic acute regulatory protein (StAR) gene: A central role for steroidogenic factor 1

Steroidogenic acute regulatory protein (StAR) plays a critical role in regulating the rate-limiting step in steroid hormone synthesis, cholesterol side-chain cleavage. StAR gene expression is transcriptionally controlled in the gonads by gonadotropic hormones via a cAMP second message. We have begun to analyze factors responsible for the transcriptional activation of the StAR gene. The human StAR gene promoter has at least two cis elements that govern basal and cAMP-regulated gene expression. One of these elements (the distal element) is a consensus binding sequence for the orphan nuclear receptor transcription factor, steroidogenic factor 1 (SF-1); the other (the proximal element) is a related motif. The human StAR promoter is not active in BeWo choriocarcinoma cells, but is functional and cAMP-responsive in murine Y1 adrenal cortical tumor cells. Cotransfection of a plasmid expressing SF-1 allows a StAR promoter construct to function in BeWo cells. Other orphan nuclear transcription factors do not support StAR promoter function in BeWo cell hosts. Deletion or mutation of the distal and proximal cis elements individually substantially reduces SF-1-supported StAR promoter activity. The distal site binds SF-1 with high affinity, whereas the proximal site binds SF-1 with lower affinities. These findings demonstrate a requirement for SF-1 for human StAR gene expression.
Revisions in analysts' earnings forecasts: evidence of non-linear adaptive expectations

Prior studies use a linear adaptive expectations model to describe how analysts revise their forecasts of future earnings in response to current forecast errors. However, research shows that extreme forecast errors are less likely than small forecast errors to persist in future years. If analysts recognize this property, their marginal forecast revisions should decrease with the forecast error's magnitude. Therefore, a linear model is likely to be unsatisfactory at describing analysts' forecast revisions. We find that a non-linear model better describes the relation between analysts' forecast revisions and their forecast errors, and provides a richer theoretical framework for explaining analysts' forecasting behaviour. Our results are consistent with analysts' recognizing the permanent and temporary nature of forecast errors of differing magnitudes. Copyright © 2000 John Wiley & Sons, Ltd.
Abuse liability of the anesthetic propofol : self-administration of propofol in rats under fixed-ratio schedules of drug delivery

Rationale: Previous reports suggest that propofol (PPF) may have abuse potential in humans. Hence, we hypothesized that PPF could reinforce self-administration behavior in other species. Positive reinforcing effects of PPF could be interpreted as an index of abuse liability. Objective: Acquisition and maintenance of i.v. PPF self-administration were examined in 12 rats. Methods: Six rats were initially given access to methohexital (MHX, 2.0 mg/kg per infusion) under a fixed ratio (FR) 1 schedule, while the other six were initially given access to PPF (1.7 mg/kg per infusion). Once stable responding was established, various doses of PPF (0.56, 1.0, and 1.7 mg/kg per infusion) and vehicle (Intralipid 20%) were made available. Results: The number of PPF infusions per session was an inverse function of dose, with 0.56 mg/kg and 1.0 mg/kg per infusion maintaining significantly more infusions per session than vehicle in most rats under the FR 1 schedule. For some rats, the number of vehicle infusions per session was equal to or greater than the number of PPF infusions. Increasing the response requirement to FR 5 decreased the number of vehicle infusions per session in these rats, while PPF maintained a higher number of infusions than vehicle under this FR value in six of seven rats. Conclusion: PPF served as a reinforcer in rats under FR schedules of i.v. drug delivery, adding to the extant evidence that it has abuse potential.
Cleavage of diarylmethanes in the presence of zinc halides

Abstract A study has been conducted of the cleavage of aliphatic linkages between aromatic centers under the influence of zinc halide catalysts. The purpose of this work was to learn more about the chemistry occurring during the liquefaction of coal. 4-Hydroxydiphenylmethane (4-HDPM), 2,4,6-trimethyldiphenylmethane (TMDPM), and 1-benzylnaphthalene (1-BN) were used to simulate structural units present in coal. ZnCl 2 , ZnBr 2 , and ZnI 2 were used as catalysts. It was found that all of the zinc halides are active when converted to a Bronsted acid by interaction with either water or methanol. For a given catalyst, the reactivity of the reactants decreases in the order TMDPM > 4HDPM >1-BN. For a given reactant, the catalyst activity decreases in the order ZnBr 2 > ZnCl 2 > ZnI 2 . Cleavage of the methylene linkage always occurred at the aryl group exhibiting the highest Bronsted basicity. The distribution of reaction products depended on reaction conditions, as well as on reactant and catalyst composition. The reaction kinetics for 4-HDPM, 1-BN, and TMPDPM can be described successfully in terms of a cabocation mechanism. Rate coefficients for each of the elementary steps in the sequence were determined by simulation of the experimental data.
A Mobility Protocol for Critically Ill Adults

Although the complications of immobility are well-described in the literature, critically ill patients are often subjected to prolonged periods of bed rest. Nurses, by virtue of their expertise in preventing iatrogenic complications, are in an ideal position to prevent the adverse outcomes associated with immobility. This article describes how nurses can use a mobility protocol to increase the activity of critically ill patients in a timely manner that may prevent the infirmity and suffering that is caused by unnecessarily long periods of bed rest.
BIRTH WEIGHTS AND MATERNAL NARCOTIC USE

Heroin (H) abuse during pregnancy has been associated with significantly lower birth weights (BW) in the offspring. Methadone (M) administration during pregnancy has generally resulted in more normally grown neonates. BW of babies born in 1971-2 to groups of mothers with varying histories of narcotic intake were compared. Mean BW of babies born to mothers taking H alone was 2397G±680 (N=39), and to mothers taking both H and M was 2547G±656 (N=25)(P > 0.05). Mean BW of babies of mothers who had abused H in the past but were drug-free during the entire pregnancy was 2421G±430 (N=18); no neonatal withdrawal was seen in this group. Mean BW in this group was no different from the group abusing H during pregnancy (P > 0.05), suggesting that H may induce physiologic changes extending beyond the period of addiction. Mean BW of babies born to mothers taking M alone was 3017G±524 (N=35). Complete M dosage schedules during pregnancy were available for 20 of these patients. Babies born to mothers taking 70 mg/day averaged 3539G±602 (N=7)(P < 0.02). A significant linear relationship between M dosage and BW was demonstrated by the calculated regression line (r=.64;P < 0.01). This data suggests that M administration during pregnancy appears to correct in a dose-dependent manner heroin-associated fetal growth retardation.
TH‐D‐204B‐03: IMRT and VMAT Inverse Planning with Compressed Sensing Techniques

The classical Shannon‐Nyquist sampling theorem specifies that to avoid losing information when capturing a signal one must sample at least two times faster than the signal bandwidth. In many medical applications the Nyquist rate may be either impractical or too expensive to be realized practically. Compressed sensing provides a practically valuable approach for finding optimal solutions with under‐ sampled data. In this talk I will summarize our recent work on using compressed sensing for IMRT and VMAT inverse planning. We show that effective utilization of prior knowledge of the systems through compressed sensing can greatly reduce the required number of measurement samples determined by the Shannon‐Nyquist theorem and leads to significantly improved IMRT/VMAT plans.Compressed sensing has significant interactions and bearings on fields of radiation oncology and medical imaging. Learning Objectives: 1. Familiarize with the concept of compressed sensing. 2. Understand the fundamental limitations of currently available IMRT and VMAT inverse planning methods. 3. Appreciate the need for a compressed sensing based inverse planning. 4. Show the impact of the proposed new inverse planning algorithm. 5. Provide perspectives on future research topics.
Determining the importance of the supplier selection process in manufacturing: a case study

This article investigates the importance of the supplier management process in the quality of the final product. A methodology is developed to analyze the variables involved in the supplier management process and it is illustrated with a case study of the chair manufacturing industry. Research results indicate that the supplier selection process appears to be the most significant variable as it helps in achieving high quality products and customer satisfaction. This paper shows the different analytical steps that arise naturally in the systematic categorization of variables for supplier management. Nine variables related to the supplier selection process were analyzed. Each of these variables was then evaluated through an experimental design using statistical information based on three factors, namely, quality, cost and productivity.
Permeability properties of tumor surrogate blood vessels induced by VEGF-A

Malignant tumors generate new blood vessels by secreting growth factors, particularly members of the vascular permeability factor/vascular endothelial growth factor (VPF/VEGF) family. Overall, the new blood vessels that form are hyperpermeable to plasma proteins, a property that is thought to be important for generating new stroma. However, tumor blood vessels are structurally heterogeneous and include microvessels of at least the following distinct types: mother vessels (MV), glomeruloid microvascular proliferations (GMP), arterio-venous-like vascular malformations and capillaries. Our goal was to determine whether macromolecular tracers leaked from all or from only a subset of these vessel types and to elucidate the extravasation pathways. As blood vessels are only a minor component of tumors, and therefore, difficult to study in situ, we used an adenoviral vector to express VEGF-A164, the most important member of the VPF/VEGF family, in mouse tissues. So expressed, VEGF-A164 induces large numbers of surrogate vessels of each type found in tumors in a highly reproducible manner. Overall permeability to plasma proteins was assessed qualitatively with Evan's blue dye and quantitatively with a dual tracer method employing radioactive albumin. Leaky vessels were identified by confocal microscopy (FITC-dextran) and by electron microscopy (ferritin). MV, and to a lesser extent GMP, were found to be hyperpermeable but capillaries and vascular malformations were not. Ferritin extravasated primarily by two trans-cellular routes, vesiculo-vacuolar organelles (VVOs) and fenestrae. This occurred despite a considerable reduction in VVO frequency as VVO membranes translocated to the plasma membrane during MV formation. However, reduction in the number and complexity of VVOs was offset by extensive endothelial cell thinning and a greatly shortened extravasation pathway. Extrapolating these findings to tumors predicts that only a subset of tumor vessels, MV and GMP, is hyperpermeable, and that measures of overall vessel permeability greatly underestimate the permeability of individual MV and GMP.
Characterization of a recycling nebulization system for inductively coupled plasma spectrometry—II. Matrix and memory effects

Abstract The matrix and memory effects in a recycling nebulization system for ICP spectrometry were investigated. The emission signals from Cu and Mn in the presence of different concentrations of aluminium, sodium and magnesium chlorides were compared during long-term (40 min) nebulization. The experimental results indicate a complex matrix effect which may depend upon analyte concentration enhancement and altered nebulization efficiency or clogging. With water presaturated carrier gas, the salt effects were minimized, and the emission signals of Cu and Mn were stable (1–2% RSD) during long-term nebulization in the presence of different matrices.
Simultaneous analysis of imipramine and its metabolite desipramine in biological fluids.

Abstract A method for the simultaneous quantitation of imipramine and its N-demethylated metabolite desipramine at the nanogram level in a single gas chromatograph peak is presented, utilizing gas chromatography-mass spectrometry with selected ion recording. The assay is specific and quantitation is achieved using [2H4]imipramine as the internal standard. The method involves the in situ methylation of desipramine with [2H2]formaldehyde and sodium borohydride to give [2H2]imipramine. Quantitation is then achieved by selected ion recording at m/z 280, 282 and 284, whence the ratio of the ion currents at 280 284 and at 282 284 gives the quantities of imipramine and desipramine respectively.
“I Am Just So Glad You Are Alive”: New Perspectives on Non-Traditional, Non-Conforming, and Transgressive Expressions of Gender, Sexuality, and Race Among African Americans

In this paper, we argue that both traditional psychology-based group identity theories related to race and sexuality and perspectives on the politics of difference obtained from poststructuralist queer theory underdetermine identity as it is experienced by a distinct subset of individuals, emblematized by non-traditional, non-conforming, and transgressive Black queers. We offer a new explanatory model for these emerging identities that is rooted in metaphysical explanations of human experience. To support our model, we draw historical and contemporary illustrations from African American popular culture.
Performance of Commercial Laying Hens Fed Diets with Various Levels of Methionine

ABSTRACT Two experiments were conducted to evaluate the Met requirement of Hy-Line W36 laying hens. In experiment 1 the temperature decreased to 26.7°C at night and reached 29.4°C during the day. In experiment 2 the temperature reached 29.4°C during the day and was not allowed to go below 28.6°C at night. Tunnel ventilation with no evaporative cooling was used in both houses. The Met requirement for egg production was obtained with 260.2 ± 4.0 and 239.4 ± 8.0 mg/d for 47.17 and 37.86 g egg content, for hens in experiments 1 and 2, respectively. There was a quadratic response for increased Met in both experiments. Maximum energy consumption was 271 and 225 kcal/d for hens in experiments 1 and 2, respectively. It is suggested that the lack of energy consumption was the cause of the low EP in experiment 2. The Met content greater than 0.30% in the diet in experiment 2 resulted in a decrease of 2.4% in egg production, 0.3 g in egg weight, and 1.6 g in egg content. This finding indicated that methionine was not the factor limiting performance.
MULTIPLE REGIME SHIFTS IN A SUBTROPICAL PEATLAND: COMMUNITY‐SPECIFIC THRESHOLDS TO EUTROPHICATION

Ecosystems have a natural resilience to perturbations, where resilience is the magnitude of a disturbance that an ecosystem can resist before changes in structure, function, and services result in a regime shift. The Everglades region of Florida, USA, has been detrimentally impacted by phosphorus (P) enrichment and a regime shift from Cladium (sawgrass) to Typha (cattail) marsh has been described. We examine another facet of the low nutrient Everglades stability regime, open-water sloughs, to determine if eutrophication leads to similar regime shifts. We analyzed surface water P and soil P as controlling variables that, once a critical threshold is surpassed, alter ecosystem state variables. Nonlinear relationships between P and vegetation were observed along a northern Everglades eutrophication gradient. In addition to the Cladium-Typha regime shift, a second independent regime shift, slough-Typha, was identified. Synoptic surveys of 49 sloughs within the boundary between the slough and Typha regime revealed that surface water total phosphorus (TP) and the benthic algal floe layer (BAFL) were the controlling variables, with critical thresholds of 11 ug/L and 412 mg/kg, respectively. The slough regime below these thresholds was characterized by calcareous periphyton (BAFL TP = 298 mg P/kg; BAFL calcium = 149 g Ca/kg). Above the TP thresholds, vegetation composition shifted to open-marsh species with significantly higher BAFL TP (700 mg P/kg) and total organic carbon (TOC) (350 g C/kg). A second BAFL TP threshold occurred at 712 mg P/kg, above which Nymphaea dominated and BAFL TP (1034 mg P/kg) and TOC (417 g C/kg) significantly increased. Nymphaea sloughs transitioned to the Typha regime. The boundary reflects the loss of ecosystem resilience due to eutrophication. Both low-nutrient stability regimes (slough and Cladium) lie precariously close to the P critical threshold but differ in how eutrophication is absorbed and resisted. The slough regime transitions rapidly through a series of ecosystem state changes linked to positive feedback loops that affect P dynamics, whereas the Cladium regime does not. An adaptive management strategy has been implemented to address the surface water TP threshold; however, to ensure successful restoration of the Everglades, the BAFL and soil TP thresholds also need to be considered.
Three-dimensional fracture and fragmentation of artificial kidney stones

The brittle fracture of a gypsum cylinder, which is used as an artificial kidney stone in lithotripsy research, is simulated by the use of the finite element method. The cylinder is submerged in water and is subjected to a pressure front parallel to one of its planar faces. The stresses induced by the pressure wave lead to fracture in the interior of the cylinder, with the formation of a spall plane located about 2/3 of the length from the face on which the pressure is applied. We show that the simulation reproduces the salient features of experimental observations.
The electromagnetic shielding depending on material's parameters

In this study, We are particularly interested in designing and analyzing chiral devices to quantify their shielding effectiveness as a function of frequency. The typical materials used for shielding are the copper, aluminium and steel. In order to do a comparative study between the different types of materials, the results obtained are presented. Due to chirality, there is magnetoelectric coupling. The electric and magnetic shielding effects are shown to be function of the three material parameters (e, μ, κ). In normal incidence the value of the coefficient of reflection of the chiral mediums is not affected by the variation of the coefficient of chirality; We found that, at normal incident angle, reflection occurs similar to that of isotropic medium. It is shown that materials are not equivalent to reduce electromagnetic fields. Shielding effectiveness depends on the material's parameters.
USP10 Regulates p53 Localization and Stability by Deubiquitinating p53

Stability and localization of p53 is essential for its tumor suppressor function. Ubiquitination by the E3 ubiquitin ligase Mdm2 is the major regulatory mechanism of p53, which induces p53 nuclear export and degradation. However, it is unclear whether ubiquitinated cytoplasmic p53 can be recycled. Here, we report that USP10, a cytoplasmic ubiquitin-specific protease, deubiquitinates p53, reversing Mdm2-induced p53 nuclear export and degradation. After DNA damage, USP10 is stabilized, and a fraction of USP10 translocates to the nucleus to activate p53. The translocation and stabilization of USP10 is regulated by ATM -mediated phosphorylation of USP10 at Thr42 and Ser337. Finally, USP10 suppresses tumor cell growth in cells with wild-type p53, with USP10 expression downregulated in a high percentage of clear cell carcinomas, known to have few p53 mutations. These findings reveal USP10 to be a novel regulator of p53, providing an alternative mechanism of p53 inhibition in cancers with wild-type p53.
A study of the serum concentration of tumor necrosis factor-α in thyroidal and nonthyroidal illnesses

We have studied serum concentrations of immunoassayable tumor necrosis factor-alpha (TNF alpha) and iodothyronines (T4, T3, and rT3) in normal subjects (n = 16) and patients with nonthyroidal illnesses (NTI; n = 13), hyperthyroidism (n = 10), and hypothyroidism (n = 9). The mean (+/- SEM; femtomoles per mL) serum concentration of TNF alpha was 45 +/- 4.3 in normal subjects, 84 +/- 38 in NTI, 54 +/- 6.0 in hyperthyroidism, and 50 +/- 10 in hypothyroidism; the various values did not differ significantly from one another. Serum TNF alpha was well within the normal range in all NTI patients, except one patient with a brain glioma and infection in whom it was elevated (540 fmol/mL). There was no significant correlation between serum TNF alpha and serum T4, T3, or rT3 levels in NTI patients. Similarly, there was no correlation between serum TNF alpha and serum thyroid hormone (T3 or T4) levels when data in normal subjects were combined with those in NTI patients. The dialyzable fraction of T3 and the free T3 concentration did not correlate with serum TNF alpha levels. However, there was a tendency toward a positive correlation between dialyzable fraction of T4 and the serum concentration of TNF alpha in NTI (r = 0.54; n = 11; 0.05 greater than P less than 0.1). The relationship between these two parameters became more clear when data in normal subjects and NTI patients were combined for statistical analysis (r = 0.59; n = 22; P less than 0.005). The free T4 concentration correlated positively with serum TNF alpha levels whether the data in NTI patients were analyzed alone (r = 0.93; P less than 0.001) or in combination with data from normal subjects (r = 0.85; P less than 0.001). Our data suggest that circulating TNF alpha may contribute to elevated free T4 in NTI. However, it is not a universal or common factor in the pathogenesis of other alterations in serum thyroid hormone levels in NTI (euthyroid sickness syndrome).
Caldesmon and the Regulation of Cytoskeletal Functions

Caldesmon (CaD) is an extraordinary actin-binding protein, because in addition to actin, it also binds myosin, calmodulin and tropomyosin. As a component of the smooth muscle and nonmuscle contractile apparatus CaD inhibits the actomyosin ATPase activity and its inhibitory action is modulated by both Ca2+ and phosphorylation. The multiplicity of binding partners and diverse biochemical properties suggest CaD is a potent and versatile regulatory protein both in contractility and cell motility. However, after decades of investigation in numerous laboratories, hard evidence is still lacking to unequivocally identify its in vivo functions, although indirect evidence is mounting to support an important role in connection with the actin cytoskeleton. This chapter reviews the highlights of the past findings and summarizes the current views on this protein, with emphasis of its interaction with tropomyosin.
Altered localization of a coactivator sensitizes breast cancer cells to tumor necrosis factor–induced apoptosis

Proline-, glutamic acid-, and leucine-rich protein-1 (PELP1) is a novel coregulator of the estrogen receptor that plays a role in both genomic and nongenomic actions of the estrogen receptor. Emerging studies suggest that in addition to the nuclear localization of PELP1, it is predominantly localized in the cytoplasm in human breast tumors, leading to excessive nongenomic signaling and possibly to tamoxifen resistance. The mechanisms underlying resistance to hormones in preclinical model systems remain under intense investigation. In an effort to develop a model system to treat tumor cells with cytoplasmic PELP1 expression and tamoxifen resistance, here we used the cytokine tumor necrosis factor (TNF)-α. We found that clones of MCF-7 human breast cancer cells overexpressing PELP1 in the cytoplasm were distinctly sensitive to TNF-α-induced apoptosis than were wild-type nuclear PELP1– and pcDNA vector–expressing clones as revealed by cell growth assay, cell cycle analysis, Annexin V staining, and terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling assay. We also found that the clones with cytoplasmic PELP1 overexpression had significantly less antiapoptotic protein Bcl-2 and nuclear factor-κB DNA binding, but increased cyclin E expression, further supporting evidence that these cells are sensitive to apoptosis. The mechanism behind TNF-induced apoptosis in these cells involves caspases, as revealed by poly(ADP-ribose) polymerase cleavage and the broad-spectrum caspase inhibitor Z-VAD-inhibited apoptosis. In conclusion, our results suggest that altered localization of PELP1 promotes heightened sensitivity to TNF-α in MCF-7 cells, paving the way for developing new treatment strategies for tumors with cytoplasmic PELP1 expression. [Mol Cancer Ther 2006;5(2):230–7]
The significance of model structure in one-dimensional stream solute transport models with multiple transient storage zones – competing vs. nested arrangements

Transient storage models are commonly used to simulate solute transport in streams to characterize hydrologic controls on biogeochemical cycling. Recently, 2-storage zone (2-SZ) models have been developed to represent in-channel surface transient storage (STS) and hyporheic transient storage (HTS) separately to overcome the limitations of single storage zone (1-SZ) models. To advance biogeochemical models, we seek to separate the effects of these storage zones on solute fate and cycling in streams. Here we compare and contrast the application and interpretations from two model structures that include STS and HTS storage: a competing model structure, where both zones are connected to the stream at the same location and the stream interacts with the STS and HTS separately, and a nested model structure, where STS is an intermediary between the stream and HTS. We adapt common residence time metrics used to compare single transient storage models for the competing and nested 2-SZ models. As a test case, we investigated the transient storage characteristics of a first-order stream in Pennsylvania, using 1-SZ, nested 2-SZ, and competing 2-SZ model configurations at several different flow conditions. While both 2-SZ models fit the observed STS and in-stream breakthrough curves well, calibrated model parameters and solute molecule travel paths differ, as evident by the faster exchange rate displayed by the nested model, and therefore so does the interpretation of associated transient storage metrics and its relationship with biogeochemical cycling processes. In addition, a study of hypothetical zone-specific reaction rates was very illustrative of the differences in discrimination characterized by each model structure, particularly for the case where reactions would predominantly occur in the STS (i.e. photochemical reactions), because of the compounding effects to the HTS for the nested 2-SZ; however, for the case where reactions would predominantly occur in the HTS, the influence of model structure was found to be relegated only to the HTS.
A pharmacokinetic-pharmacodynamic model for a muscle relaxant: atracurium

Our goal was to develop a pharmacokinetic-pharmacodynamic model that describes the fate of atracurium and its metabolite laudanosine as well as the time course of the neuromuscular block. The model was based on the consideration of mass balance of atracurium and was constructed by postulating an effect compartment linked to the central compartment in the previously described open mammillary model for atracurium. The entry and exit rate constants, kCE and kEC, were adjusted to satisfy the requirement that the peak amount in the effect compartment coincides with the peak submaximal block. We used previously published clinical data to arrive at the times to 50% neuromuscular block either during the onset of the block following an ED50 dose or during the recovery following larger doses of atracurium. Laplace transforms were used to define the model, and the solution was obtained by iterative numeric adjustments of the rate constants. The model provides an excellent fit of the observed plasma concentrations of atracurium and laudanosine and simulates well the development and waning of the neuromuscular block. The model projects that the peak amount of atracurium in the effect compartment amounts to 14% of the injected dose and is reached at 7.6 min after the injection.
A maximum likelihood algorithm for the estimation and renormalization of exponential densities

We present an algorithm based on maximum likelihood for the estimation and renormalization (marginalization) of exponential densities. The moment-matching problem resulting from the maximization of the likelihood is solved as an optimization problem using the Levenberg-Marquardt algorithm. In the case of renormalization, the moments needed to set up the moment-matching problem are evaluated using Swendsen's renormalization method. We focus on the renormalization version of the algorithm, where we demonstrate its use by computing the critical temperature of the two-dimensional Ising model. Possible applications of the algorithm are discussed.
The accelerated aging hypothesis of Parkinson's disease is not supported by the pattern of circadian melatonin secretion.

Hypotheses pertaining to the etiology of Parkinson's disease (PD) have suggested that the disease reflects an accelerated form of the normal aging process. Aging is associated with progressive fail...
RE-EVALUATION OF THE GEOGRAPHIC DISTRIBUTION AND PHYLOGEOGRAPHY OF THE SIGMODON HISPIDUS COMPLEX BASED ON MITOCHONDRIAL DNA SEQUENCES

Geographic distribution among members of the Sigmodon hispidus complex (Sigmodon hirsutus, S. hispidus, and S. toltecus) were examined using DNA sequences from the mitochondrial cytochrome-b gene. Geographic distribution of each taxon was defined based on DNA sequences obtained from 69 samples (19 newly obtained and 50 from previous studies) collected from North, Central, and South America. These data indicated that S. hispidus is restricted to the southern one-half of the United States and northeastern Mexico (Nuevo Leon and Tamaulipas), S. toltecus occupies the eastern one-third of Mexico (central Tamaulipas) to northern Honduras, and S. hirsutus is distributed from central Chiapas and southeastern Oaxaca to northern South America (Venezuela). The newly collected data extend distributions of S. hispidus from the southern United States southward into northeastern Mexico and that of S. toltecus from Chiapas, Mexico, southward to Honduras. Genetic divergence and patterns of phylogeography were examined within each taxon.