cssi/SciSciGPT-SciSciNet huggingface dataset:
Polarizability and complex conductivity of dilute suspensions of spherical colloidal particles with uncharged (neutral) polymer coatings

The polarizability of polymer-coated colloidal particles, as measured via dielectric relaxation spectroscopy, reflects on the degree to which convection, diffusion, and electromigration deform the equilibrium double layer. With a polymer coating, convection and electro-osmosis are resisted by hydrodynamic drag on the polymer segments. The electro-osmotic flow near the underlying bare surface is therefore diminished. Characteristics of the particles and the adsorbed polymer can, in principle, be inferred by measuring the frequency-dependent polarizability. In this work, "exact" numerical solutions of the electrokinetic equations are used to examine how adsorbed polymer changes the particle polarizability and, hence, the conductivity and dielectric constant increments of dilute suspensions. For neutral polymer coatings, the conductivity and dielectric constant increments are found to be very similar to those of the underlying bare particles, so the response depends mostly on the underlying bare particles. These observations suggest that dielectric spectroscopy is best used to determine the underlying surface charge, with characteristics of the coating inferred from the electrophoretic or dynamic mobility, together with the hydrodynamic radius obtained from sedimentation or dynamic light scattering. Addressed briefly are the effects of added counterions and nonspecific adsorption. The electrokinetic model explored in this work can be used to guide experiments (frequency and ionic strength, for example) to either minimize or maximize the sensitivity of the complex conductivity to the coating thickness or permeability.
Relative Perturbation Theory: I. Eigenvalue and Singular Value Variations

The classical perturbation theory for Hermitian matrix eigenvalue and singular value problems provides bounds on the absolute differences between approximate eigenvalues (singular values) and the true eigenvalues (singular values) of a matrix. These bounds may be bad news for small eigenvalues (singular values), which thereby suffer worse relative uncertainty than large ones. However, there are situations where even small eigenvalues are determined to high relative accuracy by the data much more accurately than the classical perturbation theory would indicate. In this paper, we study how eigenvalues of a Hermitian matrix A change when it is perturbed to $\wtd A=D^*AD$, where D is close to a unitary matrix, and how singular values of a (nonsquare) matrix B change when it is perturbed to $\wtd B=D_1^*BD_2$, where D1 and D2 are nearly unitary. It is proved that under these kinds of perturbations small eigenvalues (singular values) suffer relative changes no worse than large eigenvalues (singular values). Many well-known perturbation theorems, including the Hoffman--Wielandt and Weyl--Lidskii theorems, are extended.
Reversed-Phase High-Performance Liquid Chromatographic Determination of Nicotine in Pesticide Formulations

Abstract A simple and rapid reversed-phase high-performance liquid chromatographic procedure is described for the determination of nicotine in liquid formulations. Samples are diluted with methanol, and naphthalene is added as the internal standard. Peak height ratios obtained from injections of standard and sample filtrates are used for quanti-tation. An eluting solvent of 0.05M (NH4)2 HPO4 (pH 7.5) -methanol (40/60, v/v) at a flow of 2 mL/min gives retention times of 3.13 and 6.88 min respectively for nicotine and naphthalene. Sample analysis can be completed in approximately one hour by the method described as compared to 1.5 days required by the Official AOAC gravimetric method (6.176–6.177).
Structural Characterization of Distinct α3N and α5 Metal Sites in the Cyanobacterial Zinc Sensor SmtB

SmtB is required for Synechococcus to effect a response to toxic concentrations of Zn(II) and other heavy metals. Direct binding of inducing metal ions to SmtB transcriptionally derepresses the expression of SmtA, a prokaryotic class II metallothionein. Homodimeric SmtB binds one Zn(II) or Co(II) per monomer in a cysteine thiolate-containing site in a tetrahedral coordination geometry [VanZile, M. L., et al. (2000) Biochemistry 39, 11818-11829]. In this report, characterization of a set of cysteine substitution mutants of SmtB reveals that SmtB homodimer binds Zn(II) or Co(II) in one of two mutually exclusive metal binding sites, termed alpha3N and alpha5, with very high equilibrium affinities. Both sites are characterized by similar affinities for Co(II) (K(Co) approximately equal to 2-5 x 10(9) M(-1)), while the Zn(II) affinities are at least 20-fold different (K(Zn)(alpha)(3N) > or = 10(13) M(-1); K(Zn)(alpha)(5) approximately equal to 5 x 10(11) M(-1)). Co(II) bound exclusively at the alpha5 sites is capable of rapid equilibration between the alpha3N and alpha5 sites upon reduction of the mixed disulfides in S-methylated SmtB. These results suggest that the alpha3N or alpha5 metal sites might play distinct roles in this Zn(II)-sensing protein, systematically investigated in the following paper [VanZile, M. L., Chen, X., and Giedroc, D. P. (2002) Biochemistry 41, 9776-9786]. Since both the alpha3N and alpha5 sites are present in many members of the SmtB/ArsR family of metal sensor proteins, the presence of these two metal binding sites may explain some of the functional diversity in metal responses across this family of proteins.
20 YEARS OF LEPTIN: Role of leptin in energy homeostasis in humans

The hyperphagia, low sympathetic nervous system tone, and decreased circulating concentrations of bioactive thyroid hormones that are common to states of congenital leptin deficiency and hypoleptinemia following and during weight loss suggest that the major physiological function of leptin is to signal states of negative energy balance and decreased energy stores. In weight-reduced humans, these phenotypes together with pronounced hypometabolism and increased parasympathetic nervous system tone create the optimal circumstance for weight regain. Based on the weight loss induced by leptin administration in states of leptin deficiency (obese) and observed similarity of phenotypes in states of congenital and dietary-induced states of hypoleptinemia (reduced obese), it has been suggested that exogenous leptin could potentially be useful in initiating, promoting, and sustaining weight reduction. However, the responses of human beings to exogenous leptin administration are dependent not only on extant energy stores but also on energy balance. Leptin administration to humans at usual weight has little, if any, effect on body weight while leptin administration during weight loss mitigates hunger, especially if given in supraphysiological doses during severe caloric restriction. Leptin repletion is most effective following weight loss by dietary restriction. In this state of weight stability but reduced energy stores, leptin at least partially reverses many of the metabolic, autonomic, neuroendocrine, and behavioral adaptations that favor weight regain. The major physiological function of leptin is to signal states of negative energy balance and decreased energy stores. Leptin, and pharmacotherapies affecting leptin signaling pathways, is likely to be most useful in sustaining weight loss.
Exploring Whiteness and Multicultural Education with Prospective Teachers

In this article, I describe how I initiate an examination of whiteness with predominantly white students in teacher preparation programs by the use of group collages—a pedagogical tool that combines visual, textual, and oral representations of subject matter. In doing so, I illustrate one of the ways teacher educators can provide students with opportunities to (1) “see” whiteness as an integral aspect of educational discourse, (2) fix their gaze on themselves as a collective racial group, and (3) engage in processes aimed at changing beliefs, stereotypes, and practices that reproduce social and educational injustice.
Project management infrastructure: The key to operational performance improvement

Process improvement programs such as Six Sigma, Lean, and Lean Sigma are very important and deserve serious academic research attention. However, definition problems make it difficult to study any specific type of process improvement program. Therefore, this study defines two organizational level program management factors, Strategic Project Selection (SPS) and Project Management Infrastructure (PMI), that are independent of any specific process improvement program. Drawing upon current literature, this study develops and tests theoretical models that relate SPS and PMI to operational performance improvement and to each other. Using empirical data collected from 53 supplier plants of one large high-tech firm, this study finds that at the plant level, SPS mediates the relationship between PMI and operational performance improvement. This insight contributes to both theory development and practice, suggesting that a viable strategy for a process improvement program’s success is to focus on PMI in order to enhance SPS and ultimately improve performance.
Numerical simulations of non-ergodic solute transport in three-dimensional heterogeneous porous media

Numerical simulations of non-ergodic transport of a non-reactive solute plume by steady-state groundwater flow under a uniform mean velocity, μ, were conducted in a three-dimensional heterogeneous and statistically isotropic aquifer. The hydraulic conductivity, K(x), is modeled as a random field which is assumed to be log-normally distributed with an exponential covariance. Significant efforts are made to reduce the simulation uncertainties. Ensemble averages of the second spatial moments of the plume and the plume centroid variances were simulated with 1600 Monte Carlo (MC) runs for three variances of log K, σY2=0.09, 0.23, and 0.46, and a square source normal to μ of three dimensionless lengths. It is showed that 1600 MC runs are needed to obtain stabilized results in mildly heterogeneous aquifers of σY2≤0.5 and that large uncertainty may exist in the simulated results if less MC runs are used, especially for the transverse second spatial moments and the plume centroid variance in transverse directions. The simulated longitudinal second spatial moment and the plume centroid variance in longitudinal direction fit well to the first-order theoretical results while the simulated transverse moments are generally larger than the first-order values. The ergodic condition for the second spatial moments is far from reaching in all cases simulated and transport in transverse directions may reach ergodic condition much slower than that in longitudinal direction.
Upland Adjustment to Regional Drainage in Central Pennsylvania: An Application of Trend Surface Analysis

Abstract The use of quantitative measurements in geography has increased rapidly throughout the 1960s, and will probably continue to accelerate. It is unfortunate that those with limited mathematical backgrounds have felt intimidated by this new methodology. Even more regrettable is the fact that few quantifiers have attempted to make their work more palatable to a wider audience. The method of trend surface analysis employed here to explore an old problem—peneplanation—has many other potential applications in geographic research. The author believes that no geographer should feel intimidated by mathematical symbolism. An attempt is made to “talk-through” the technique of spatial trend analysis—one of many measurement tools already or shortly available to geography teachers and high school students via remote terminals linked to university computing centers. In addition, the concepts of the Erosion Cycle and upland accordance are reviewed and evaluated in the light of new evidence trend surface analysis n...
Modulation of CD4 T cell function by soluble MHC II-peptide chimeras.

Peptides antigens of 8 to 24 amino acid residues in length that are derived from processing of foreign proteins by antigen presenting cells (APC), and then presented to T cells in the context of major histocompatibility complex molecules (MHC) expressed by APC, are the only physiological ligands for T cell receptor (TCR). Co-ligation of TCR and CD4 co-receptor on T cells by MHC II-peptide complexes (signal 1) leads to various T cell functions depending on the nature of TCR and CD4 co-ligation, and whether costimulatory receptors (signal 2) such as CD28, CTLA-4, CD40L are involved in this interaction. Recently, the advance of genetic engineering led to the generation of a new class of antigen-specific ligands for TCR, i.e., soluble MHC class I-, and MHC class II-peptide chimeras. In principle, these chimeric molecules consist of an antigenic peptide which is covalently linked to the amino terminus of alpha-chain in the case of MHC I, or beta-chains in the case of MHC II molecules. Conceptually, such TCR/CD4 ligands shall provide the signal 1 to T cells. Since soluble MHC-peptide chimeras showed remarkable regulatory effects on peptide-specific T cells in vitro and in vivo, they may represent a new generation of immunospecific T cell modulators with potential therapeutic applicability in autoimmune and infectious diseases. This review is focused on the immunomodulatory effects of soluble, MHC class II-peptide chimeras, and discuss these effects in the context of the most accepted theories on T cell regulation.
A proposed framework for economic evaluation of telemedicine

Economic evaluation of telemedicine compares the costs and other consequences of delivering specific services through telemedicine vs. alternative means. Cost-effectiveness analysis, the most common method used for health issues, helps to assess whether the expected health benefits are worth the investment. Telemedicine raises particular challenges for evaluators: a telemedicine system may have multiple uses and joint costs that are difficult to apportion to one service, the existence of a system may lead to expanded indications for use, and technological change may rapidly make an evaluation outdated. Public and private regulation and payment may affect the diffusion of telemedicine. Uncertainty surrounds the policy.of the U.S. Food and Drug Administration, which is still formulating its position. Changes are underway in policies on licensure and credentialing of clinicians, which have traditionally been done by state and by site, to reflect the fact that telemedicine services may cross these regional bo...
Staying in the spa marketing game: Trends, challenges, strategies and techniques:

The spa industry in the USA has shown robust growth in sales volume and in the number of facilities. This growth is driven by baby-boomers who want a place where they can get spa treatments that improve their physical and mental well-being, and which offers rest, relaxation, exercise and pampering. Spas are providing a myriad of opportunities for improving the mind and body. Despite the growth currently taking place in the spa industry, there are still challenges to consider. The authors highlight current issues and trends in the US spa industry. Strategies and techniques for spa marketers to combat potential challenges are suggested under the headings of target markets, product, place, promotion and price.
A Generalization of Fisher's Inequality

In this paper we are concerned with the following conjecture. Conjecture: Let L be a collection ofkpositive integers and A={A1,?,Am} denote a family of subsets of ann-element set such that |Ai?Aj|?L, for allAi,Aj?A, then |A|??ki=0 ([equation]). In particular, we show this conjecture is true when L consists ofkconsecutive positive integers. This generalizes a well-known inequality of Fisher's. Our proof simplifies and extends a recent result of Ramanan's.
Outcomes in community‐acquired Clostridium difficile infection

Summary Background Community-acquired Clostridium difficile infection (CA-CDI) is an increasingly appreciated condition. It is being described in populations lacking traditional predisposing factors that have been previously considered at low-risk for this infection. As most studies of CDI are hospital-based, outcomes in these patients are not well known. Aim To examine outcomes and their predictors in patients with CA-CDI. Methods A sub-group analysis of a population-based epidemiological study of CDI in Olmsted county, Minnesota from 1991–2005 was performed. Data regarding outcomes, including severity, treatment response, need for hospitalisation and recurrence were analysed. Results Of 157 CA-CDI cases, the median age was 50 years and 75.3% were female. Among all CA-CDI cases, 40% required hospitalisation, 20% had severe and 4.4% had severe-complicated infection, 20% had treatment failure and 28% had recurrent CDI. Patients who required hospitalisation were significantly older (64 years vs. 44 years, P < 0.001), more likely to have severe disease (33.3% vs. 11.7%, P = 0.001), and had higher mean Charlson comorbidity index scores (2.06 vs. 0.84, P = 0.001). They had similar treatment failure and recurrence rates as patients who did not require hospitalisation. Conclusions Community-acquired Clostridium difficile infection can be associated with complications and poor outcomes, including hospitalisation and severe Clostridium difficile infection. As the incidence of community-acquired Clostridium difficile infection increases, clinicians should be aware of risk factors (increasing age, comorbid conditions and disease severity) that predict the need for hospitalisation and complications in patients with community-acquired Clostridium difficile infection.
Structural, chemical and luminescent investigation of MBE- and CSS-deposited CdTe thin-films for solar cells

In this study we combine scanning electron microscopy (SEM)-based cathodoluminescence (CL) spectrum imaging and electron backscatter diffraction (EBSD) in order to map the spatial distribution of various atomic-level defects in CdTe films as a function of deposition and film processing. Two different deposition techniques were used. Lattice-matched, epitaxial CdTe films were deposited on a single crystal as well as on polycrystalline CdTe substrates by molecular beam epitaxy (MBE). For comparison purposes, polycrystalline CdTe films were deposited using our standard close-spaced sublimation (CSS) method on glass-based substrates.
A hybrid biomimetic nanomatrix composed of electrospun polycaprolactone and bioactive peptide amphiphiles for cardiovascular implants

Abstract Current cardiovascular therapies are limited by the loss of endothelium, restenosis and thrombosis. The goal of this study was to develop a biomimetic hybrid nanomatrix that combined the unique properties of electrospun polycaprolactone (ePCL) nanofibers with self-assembled peptide amphiphiles (PAs). ePCL nanofibers have interconnected nanoporous structures, but are hampered by a lack of surface bioactivity to control cellular behavior. It has been hypothesized that PAs could self-assemble onto the surface of ePCL nanofibers and endow them with the characteristic properties of native endothelium. The PAs, which comprised hydrophobic alkyl tails attached to functional hydrophilic peptide sequences, contained enzyme-mediated degradable sites coupled to either endothelial cell-adhesive ligands (YIGSR) or polylysine (KKKKK) nitric oxide (NO) donors. Two different PAs (PA–YIGSR and PA–KKKKK) were successfully synthesized and mixed in a 90:10 (YK) ratio to obtain PA–YK. PA–YK was reacted with pure NO to develop PA–YK–NO, which was then self-assembled onto ePCL nanofibers to generate a hybrid nanomatrix, ePCL–PA–YK–NO. Uniform coating of self-assembled PA nanofibers on ePCL was confirmed by transmission electron microscopy. Successful NO release from ePCL–PA–YK–NO was observed. ePCL–YK and ePCL–PA–YK–NO showed significantly increased adhesion of human umbilical vein endothelial cells (HUVECs). ePCL–PA–YK–NO also showed significantly increased proliferation of HUVECs and reduced smooth muscle cell proliferation. ePCL–PA–YK–NO also displayed significantly reduced platelet adhesion compared with ePCL, ePCL–PA–YK and a collagen control. These results indicate that this hybrid nanomatrix has great potential application in cardiovascular implants.
Red dye No. 2 and the red pigment carmine enhance aryl hydrocarbon hydroxylase and guanylate cyclase activities

The food coloring amaranth (F, D and C red No. 2) and the red pigment carmine, but not erythrosine (F, D and C red No. 3), caused a twofold enhancement of two enzymes (aryl hydrocarbon hydroxylase and guanylate cyclase) that have been linked with chemical carcinogenesis. Dose response relationships revealed that carmine enhanced both enzymes to near maximal levels at concentrations as low as 1 to 10 nM while amaranth needed a concentration of 100 nM to cause a maximal enhancement. These data suggest that amaranth and carmine mimic the effects of some chemical carcinogens at the cellular level, but erythrosine does not mimic any of these effects.
Ziprasidone: profile on safety.

Ziprasidone (Geodon™, Pfizer) is the latest of a new class of atypical antipsychotics, following the release of clozapine, risperidone, olanzapine and quetiapine. It has a serotonin Type 2a/dopamine Type 2 (5-HT2a/D2) receptor (R) binding ratio of approximately 8:1; amongst the highest of its class. Furthermore, it is a potent 5-HT1aR agonist, and displays 5-HT1dR and 5-HT2cR antagonist activity, with unique effects on blocking the re-uptake of both 5-HT and noradrenaline (NE). Finally, ziprasidone has low-to-modest affinity for histamine (H1) and α1-adrenoceptors and a negligible affinity for muscarinic (M1) Rs. This combination of effects may be responsible for its low rate of general adverse events, low rate of persistent prolactin elevation, low incidence of weight gain, low liability for inducing movement disorders, low rate of syncope and induction of decreases in lipid profile. Data on the effect of ziprasidone on the electrocardiogram (ECG) indicates a relatively higher degree of change in measure...
Sensitivity of monthly convective precipitation to environmental conditions.

Abstract Identifying dynamical and physical mechanisms controlling variability of convective precipitation is critical for predicting intraseasonal and longer-term changes in warm-season precipitation and convectively driven large-scale circulations. On a monthly basis, the relationship of convective instability with precipitation is examined to investigate the modulation of convective instability on precipitation using the Global Historical Climatology Network (GHCN) and NCEP–NCAR reanalysis for 1948–2003. Three convective parameters—convective inhibition (CIN), precipitable water (PW), and convective available potential energy (CAPE)—are examined. A lifted index and a difference between low-tropospheric temperature and surface dewpoint are used as proxies of CAPE and CIN, respectively. A simple correlation analysis between the convective parameters and the reanalysis precipitation revealed that the most significant convective parameter in the variability of monthly mean precipitation varies by regions a...
Chorus dynamics of a neotropical amphibian assemblage: comparison of computer simulation and natural behaviour

Abstract The high population density of vocalizing males of the Puerto Rican treefrog Eleutherodactylus coqui in their natural habitat can lead to call overlap, which may interfere with the function of the call. Simulations of groups of calling males suggest that a given male can maximize the effectiveness of each call by actively avoiding acoustic overlap with at most two of its nearest neighbours. Analysis of vocal patterns of natural groups of frogs support this hypothesis: 14 of the 18 frogs tested actively avoided acoustic overlap with no more than two neighbours (one avoided acoustic overlap with three neighbours) while three frogs exhibited active call-jamming with one of their neighbours. Moreover, cross-correlograms of calling patterns between all pairs of frogs in a group were used to infer dynamic chorus structure. Overlap avoidance behaviour is discussed in terms of reproductive success and predator evasion.
Phospholipase A2 mediates immediate early genes in cultured renal epithelial cells: Possible role of lysophospholipid

Phospholipase A 2 mediates immediate early genes in cultured renal epithelial cells: Possible role of lysophospholipid. Background Exposure to high levels of oxalate induces oxidant stress in renal epithelial cells and produces diverse changes in cell function, ranging from cell death to cellular adaptation, as evidenced by increased DNA synthesis, cellular proliferation, and induction of genes associated with remodeling and repair. These studies focused on cellular adaptation to this oxidant stress, examining the manner by which oxalate exposure leads to increased expression of immediate early genes (IEGs). Specifically, our studies assessed the possibility that oxalate-induced changes in IEG expression are mediated by phospholipase A 2 (PLA 2 ), a common pathway in cellular stress responses. Methods Madin-Darby canine kidney (MDCK) cells were exposed to oxalate in the presence or absence of PLA 2 inhibitors: mepacrine and arachidonyl trifluoromethyl ketone (AACOCF 3 ). Expression of IEG (c- jun , egr -1, and c- myc ) mRNA was assessed by Northern blot analysis. PLA 2 activity was determined by measuring the release of [ 3 H]arachidonic acid (AA) from prelabeled cells. Results Oxalate exposure (1 to 1.5 mmol/L) induced time- and concentration-dependent increases in IEG mRNA. Treatment with mepacrine resulted in a 75 to 113% reduction of oxalate-induced c- jun , egr -1, and c- myc mRNA, while AACOCF 3 caused a 41 to 46% reduction of oxalate-induced c- jun and egr -1 mRNA. Of the two major byproducts of PLA 2 , only lysophosphatidylcholine (20 μmol/L) increased c- jun and egr -1 mRNA. In contrast, AA (25 μmol/L) attenuated the oxalate-induced increase in c- jun and egr -1 mRNA, presumably by inhibiting PLA 2 activity. Conclusions These findings suggest that PLA 2 plays a major role in oxalate-induced IEG expression in renal epithelial cells and that lysophospholipids might be a possible lipid mediator in this pathway.
Polysemy and memory

The degree of ambiguity of words with multiple meanings was estimated by the semantic uncertainty (U) of a word as measured by word association and sentence generation tasks. Ambiguous words defined in this way were as well remembered in a recognition memory test as control words. When words were first presented in sentences that would determine their encoded sense, it was found that successive encodings of an ambiguous word converged more when the word appeared in its primary sense than when it appeared in its secondary sense. However, given convergent encodings, recognition was more likely if the word had first occurred in its secondary sense. An explanation in terms of semantic focus is offered and related to the general relationship between recognition and frequency.
Influence of Milk Peptides in Determining the Functionality of Milk Proteins: A Review

Abstract Milk is a rich source of functional ingredients. Unfortunately, milk is also rich in surface-active peptides that modulate the functionality of milk proteins. Fractionation, amino acid analysis and sequencing, and computerized hydropathy calculations showed that these peptides are highly amphipathic. These peptides exert their effects primarily by markedly decreasing surface or interfacial tension and by altering the colloidal properties of proteins. The hydrophobically driven association tendency of proteins, which plays a key role in interfacial stability, is diminished because of the masking of hydrophobic patches by the peptides. Destabilization of emulsions, to an extent, may also be due to desorption of proteins from the interface as a result of the greater surface activity of amphipathic peptides. Experiments are described in which controlled hydrolysis to generate trace amounts of peptides significantly altered the functionality of milk protein powders. Some theoretical bases of the observations are discussed.
Denervation of the external branch of the superior laryngeal nerve: laryngeal and phonatory features.

Purpose of reviewThe external branch of the superior laryngeal nerve (ESLN) innervates the cricothyroid muscle of the larynx, a vocal fold tensor primarily responsible for pitch elevation. A longstanding controversy is revisited regarding the laryngeal and phonatory signs that should be considered i
Neuroprotective effects of estrogens and androgens in CNS inflammation and neurodegeneration

Multiple sclerosis (MS) is a disease characterized by inflammation and demyelination. Currently, the cause of MS is unknown. Experimental autoimmune encephalomyelitis (EAE) is the most common mouse model of MS. Treatments with the sex hormones, estrogens and androgens, are capable of offering disease protection during EAE and are currently being used in clinical trials of MS. Beyond endogenous estrogens and androgens, treatments with selective estrogen receptor modulators (SERMs) for estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) are also capable of providing disease protection. This protection includes, but is not limited to, prevention of clinical disease, reduction of CNS inflammation, protection against demyelination, and protection against axonal loss. In EAE, current efforts are focused on using conditional cell specific knockouts of sex hormone receptors to identify the in vivo targets of these estrogens and androgens as well as downstream molecules responsible for disease protection.
New insights into Vitamin D sterol-VDR proteolysis, allostery, structure-function from the perspective of a conformational ensemble model.

Abstract Recently, we have developed a Vitamin D sterol (VDS)-VDR conformational ensemble model. This model can be broken down into three individual, yet interlinked parts: (a) the conformationally flexible VDS, (b) the apo/holo-VDR helix-12 (H12) conformational ensemble, and (c) the presence of two VDR ligand binding pockets (LBPs); one thermodynamically favored (the genomic pocket, G-pocket) and the other kinetically favored by VDSs (the alternative pocket, A-pocket). One focus of this study is to use directed VDR mutagenesis to (1) demonstrate H12 is stabilized in the transcriptionally active closed conformation (hVDR-c1) by three salt-bridges that span the length of H12 (cationic residues R154, K264 and R402), (2) to elucidate the VDR trypsin sites [R173 (hVDR-c1), K413 (hVDR-c2) and R402 (hVDR-c3)] and (3) demonstrate the apo-VDR H12 equilibrium can be shifted. The other focus of this study is to apply the model to generate a mechanistic understanding to discrepancies observed in structure–function data obtained with a variety of 1α,25(OH)2-Vitamin D3 (1,25D) A-ring and side-chain analogs, and side-chain metabolites. We will demonstrate that these structure–function conundrums can be rationalized, for the most part by focusing on alterations in the VDS conformational flexibility and the elementary interaction between the VDS and the VDR A- and G-pockets, relative to the control, 1,25D.
Ion-exchange displacement chromatography of serum proteins, using carboxymethyldextrans as displacers.

Abstract A system of displacers comprising carboxymethyldextrans with progressively higher content of carboxyl groups forms a displacement train in which absorbed proteins find positions according to their affinities for the adsorbent, an anion exchanger. Because little or no salt need be used, effluent fractions can be evaluated directly by gel electrophoresis. Application to the fractionation of serum proteins is demonstrated.
Grb10/Nedd4-mediated multiubiquitination of the insulin-like growth factor receptor regulates receptor internalization

The adaptor protein Grb10 is an interacting partner of the IGF-I receptor (IGF-IR) and the insulin receptor (IR). Previous work from our laboratory has established the role of Grb10 as a negative regulator of IGF-IR-dependent cell proliferation. We have shown that Grb10 binds the E3 ubiquitin ligase Nedd4 and promotes IGF-I-stimulated ubiquitination, internalization, and degradation of the IGF-IR, thereby giving rise to long-term attenuation of signaling. Recent biochemical evidence suggests that tyrosine-kinase receptors (RTK) may not be polyubiquitinated but monoubiquitinated at multiple sites (multiubiquitinated). However, the type of ubiquitination of the IGF-IR is still not defined. Here we show that the Grb10/Nedd4 complex upon ligand stimulation mediates multiubiquitination of the IGF-IR, which is required for receptor internalization. Moreover, Nedd4 by promoting IGF-IR ubiquitination and internalization contributes with Grb10 to negatively regulate IGF-IR-dependent cell proliferation. We also demonstrate that the IGF-IR is internalized through clathrin-dependent and-independent pathways. Grb10 and Nedd4 remain associated with the IGF-IR in early endosomes and caveosomes, where they may participate in sorting internalized receptors. Grb10 and Nedd4, unlike the IGF-IR, which is targeted for lysosomal degradation are not degraded and likely directed into recycling endosomes. These results indicate that Grb10 and Nedd4 play a critical role in mediating IGF-IR down-regulation by promoting ligand-dependent multiubiquitination of the IGF-IR, which is required for receptor internalization and regulates mitogenesis.
Local knockdown of the NaV1.6 sodium channel reduces pain behaviors, sensory neuron excitability, and sympathetic sprouting in rat models of neuropathic pain

In the spinal nerve ligation (SNL) model of neuropathic pain, as in other pain models, abnormal spontaneous activity of myelinated sensory neurons occurs early and is essential for establishing pain behaviors and other pathologies. Sympathetic sprouting into the dorsal root ganglion (DRG) is observed after SNL, and sympathectomy reduces pain behavior. Sprouting and spontaneous activity may be mutually reinforcing: blocking neuronal activity reduces sympathetic sprouting, and sympathetic spouts functionally increase spontaneous activity in vitro. However, most studies in this field have used nonspecific methods to block spontaneous activity, methods that also block evoked and normal activity. In this study, we injected small inhibitory (si) RNA directed against the NaV1.6 sodium channel isoform into the DRG before SNL. This isoform can mediate high-frequency repetitive firing, like that seen in spontaneously active neurons. Local knockdown of NaV1.6 markedly reduced mechanical pain behaviors induced by SNL, reduced sympathetic sprouting into the ligated sensory ganglion, and blocked abnormal spontaneous activity and other measures of hyperexcitability in myelinated neurons in the ligated sensory ganglion. Immunohistochemical experiments showed that sympathetic sprouting preferentially targeted NaV1.6-positive neurons. Under these experimental conditions, NaV1.6 knockdown did not prevent or strongly alter single evoked action potentials, unlike previous less specific methods used to block spontaneous activity. NaV1.6 knockdown also reduced pain behaviors in another pain model, chronic constriction of the sciatic nerve, provided the model was modified so that the lesion site was relatively close to the siRNA-injected lumbar DRGs. The results highlight the relative importance of abnormal spontaneous activity in establishing both pain behaviors and sympathetic sprouting, and suggest that the NaV1.6 isoform may have value as a therapeutic target.
Neuroglian and DE-Cadherin Activate Independent Cytoskeleton Assembly Pathways in Drosophila S2 Cells

The cytoskeletal proteins spectrin and ankyrin colocalize with sites of E-cadherin-mediated cell–cell adhesion in mammalian cells. Here we examined the effects of Drosophila DE-cadherin expression on spectrin and ankyrin in Drosophila S2 tissue culture cells. DE-cadherin caused a dramatic change in the cytoplasmic concentration and distribution of armadillo, the Drosophila homolog of β catenin. However, DE-cadherin expression had no detectable effect on the quantity or subcellular distribution of ankyrin or spectrin. In reciprocal experiments, recruitment of ankyrin and αβ spectrin to the plasma membrane by another cell adhesion molecule, neuroglian, had no effect on the quantity or distribution of armadillo. The results indicate that DE-cadherin–catenin complexes and neuroglian-spectrin/ankyrin complexes form by nonintersecting pathways. Recruitment of spectrin does not appear to be a conserved feature of DE-cadherin function.
Performance of Standard Phenotypic Assays for TonB Activity, as Evaluated by Varying the Level of Functional, Wild-Type TonB

The ability of gram-negative bacterial cells to transport cobalamin and iron-siderophore complexes and their susceptibility to killing by some bacteriophages and colicins are characteristics routinely used to assay mutations of proteins in the TonB-dependent energy transduction system. These assays vary greatly in sensitivity and are subject to perturbation by overexpression of TonB and, perhaps, other proteins that contribute to the process. Thus, the choice of assay and the means by which a potential mutant is expressed can greatly influence the interpretation and recognition of a given mutant. In the present study, we expressed TonB at several different quantified levels in cells that were then subjected to a panel of assays. Our results suggest that it is reasonable to regard the assays as having windows of sensitivity. Thus, while no single assay satisfactorily spans the potential range of TonB activity, it is evident that certain assays are better suited for resolving small deviations from wild-type levels of activity, with others most useful when activity levels are very low. It is apparent from the results that the application of all possible assays to the characterization of new mutants will yield the most meaningful results.
CFD MODELING OF A SOLITARY WAVE OVERTOPPING BREAKWATER OF VARYING SUBMERGENCE

In this paper, interaction of a nonlinear solitary wave with a submerged breakwater as well as a breakwater with zero freeboard are modeled using Computational Fluid Dynamic (CFD). Simulation results of water particle velocities as well as water surface elevations at the vicinity of breakwater are validated by comparison to experimental data. In order to find out the best turbulence modeling appropriate for wave-breakwater interaction problem, simulations are conducted using standard K-Epsilon, SST-K Omega, and inviscid models available within the CFD software. In cases involving wave breaking, simulations are also repeated using second order SST-K-Omega model. The overall pattern of the wave interaction with breakwater is adequately reproduced by the CFD software. The processes of wave reflection, wave breaking, and vortical motion at the vicinity of breakwater are correctly captured. The good results achieved are promising regarding the use of CFD for design of breakwaters and other marine structures subject to waves.
EFFECTS OF SCREEN SIZE, SCREEN RESOLUTION, AND DISPLAY RATE ON COMPUTER‐BASED TEST PERFORMANCE

Computer-based tests administered in established commercial testing centers typically have used monitors of uniform size running at a set resolution. Web-based delivery of tests promises to expand access, but at the price of less standardization in equipment. This study evaluated the effects of variations in screen size, resolution, and presentation delay on verbal and mathematics scores in a sample of 357 collegebound high school juniors. There were 3 screen display conditions crossed with 2 presentation rate conditions: a 17-in. monitor set to a resolution of 1024 × 768, a 17-in. monitor set to a resolution of 640 × 480, and a simulated 15-in. monitor set to a resolution of 640 × 480 with items presented either with no delay or with a 5-sec delay between questions (to emulate a slow Internet connection). No significant effects on math scores were found. Verbal scores were higher, by about a quarter of a standard deviation, with the larger high-resolution display.
The assembly of ribosomes.

Functionally active 30S ribosomes can be reconstituted in vitro from 16S RNA and a mixture of 30S ribosomal proteins under certain defined conditions. Our previous studies on the specificity and kinetics of reconstitution are summarized and discussed. The reconstitution reaction is first-order with respect to formation of active 30S ribosomes. The rate-limiting reaction is probably unimolecular, and it represents the structural rearrangement of an intermediate. Presumed reconstitution intermediates, or RI particles, have been isolated from reconstitution mixtures incubated at low temperature. It has been concluded that the reconstitution takes place in stepwise fashion: 16S ribosomes. New experimental results that show the highly cooperative nature of the assembly reaction are described; the number of sites, per RNA chain, which can bind ribosomal proteins independently from each other (i.e., without cooperativity) is at most two to three. Finally, another approach to the study of ribosome assembly in vivo is described. It utilizes cold-sensitive E. coli mutants that are defective in ribosome biosynthesis at low temperature and accumulate incomplete “intermediate” ribosomal particles.
Positive communication in health and wellness

How can positive communication impact health or constitute wellness? Particularly, how can communication contribute to a life that is pleasant, engaged, relationally rich, meaningful and filled wit...
NASA's L-band imaging scatterometer

The NASA RADSTAR instrument is a compact scatterometer-radiometer system designed for airborne and space remote sensing of Earth surface properties such as soil moisture and sea surface salinity. In this paper we describe the active portion of RADSTAR, the L-band Imaging Scatterometer (LIS). The system employs electronic steering and digital beamforming techniques to generate multiple, low-sidelobe beams over a scan range of +/-50 degrees below an aircraft. We discuss the design and testing of LIS, and the planned merging of the scatterometer with the radiometric components of the final instrument. In its final configuration, RadSTAR will employ a single broadband antenna to efficiently support simultaneous scatterometer (LIS) and radiometer measurements in airborne and spaceborne applications. LIS is currently being flown along with the ESTAR synthetic aperture radiometer aboard the NASA P-3 aircraft in order to prove the concept of coregistered data, setting the path for future spaceborne, single aperture, electronically scanned, radar/radiometer systems.
Effect of vacuum drying on protein-mannitol interactions: the physical state of mannitol and protein structure in the dried state.

The purpose of the present studies was to systematically investigate protein-mannitol interactions using vacuum drying, to obtain a better understanding of the effect of protein/mannitol wt/wt ratios on the physical state of mannitol and protein secondary structure in the dried state. Solutions containing β-lactoglobulin (βLg):mannitol (1∶1–1∶15 wt/wt) were vacuum dried at 5°C under 3000 mTorr of pressure. The physical state of mannitol was studied using x-ray powder physical state of mannitol was studied using x-ray powder diffractometry (XRPD), polarized light microscopy (PLM), Fourier-transform infrared (FTIR) spectroscopy, and modulated differential scanning calorimetry (MDSC). XRPD studies indicated that mannitol remained amorphous up to 1∶5 wt/wt βLg:mannitol ratio, whereas PLM showed the presence of crystals of mannitol in all dried samples except for the 1∶1 wt/wt βLg:mannitol dried sample. FITR studies indicated that a small proportion of crystalline mannitol was present along with the amorphous mannitol in dried samples at lower (less than 1∶5 wt/wt) βLg:mannitol ratios. The Tg of the dried 1∶1 wt/wt βLg:mannitol sample was observed at 33.4°C in MDSC studies, which indicated that at least a part of mannitol co-existed with protein in a single amorphous phase. Evaluation of the crystallization exotherms indicated that irrespective of the βLg:protein wt/wt ratio in the initial sample, the protein to amorphous mannitol ratio was below 1∶1 wt/wt in all dried samples. Second-derivative FTTR studies on dried βLg and recombinant human interferon α-2a samples showed that mannitol affected protein secondary structure to a varying degree depending on the overall mannitol content in the dried sample and the type of protein.
The Culture of High Crime Societies

In a continuing attempt to explain the emergence of new strategies of crime control in the UK and USA, a theory of cultural adaptation is developed. The paper argues that the political and policy shifts of recent years have been conditioned by prior changes that have occurred at the level of social structures and cultural sensibilities. A historical account of these changes is outlined, together with a characterization of the culture of high crime societies.
NAPSS-like systems: problems and prospects

This paper arises from the development of NAPSS and discusses the problems solved and still to be solved in this area. The original paper contains two phrases which define the objectives of NAPSS (and NAPSS-like systems) in general, yet reasonably precise, terms:"Our aim is to make the computer behave as if it had some of the knowledge, ability and insight of a professional numerical analyst.""describe relatively complex problems in a simple mathematical language---including integration, differentiation, summation, matrix operations, algebraic and differential equations, polynomial and other approximations as part of the basic language."
On the use of various shell theories in the analysis of axisymmetrically loaded circular containers

Abstract In shell literature there are several theories concerning the behavior of thin shells and a few regarding the behavior of thick and moderately thick shells. This paper is an attempt to bridge the gap that exists in the practicing engineer's mind as to when the validity of the theory of thin shells ceases and when that of thick shells begins. The problem of an axisymmetrically loaded container in the form of a cylindrical shell is analyzed, using both thick and thin shell theories for various values of t R and a recommendation is made regarding the bifurcation point between thin and thick shell theories.
Magnetization reversal in elliptical-ring nanomagnets

The magnetization reversal exhibited by elliptical-ring-shaped magnets has been investigated using magnetic force microscopy and micromagnetic simulations. Arrays of cobalt elliptical-ring structures of thickness 12 nm, long axis 930 nm, short axis 620 nm and ring widths 110, 140 and 200 nm were investigated. The rings show transitions between onion (bidomain) states, twisted states (containing 360° walls) and vortex (flux-closed) magnetization states with increasing field. The switching fields are lower for wider rings, and depend on the applied field direction. When the field is parallel to the short axis, the vortex state is stable over a smaller range of fields, intermediate states such as 360° walls are more commonly observed, and the rings show greater reversible magnetization.