cssi/SciSciGPT-SciSciNet huggingface dataset:
Norepinephrine Increases Cyclic GMP Levels in Cerebellar Cells from Neuronal Nitric Oxide Synthase Knockout Mice

Cyclic GMP is an important intracellular messenger in the nervous system that may mediate cellular forms of neuronal plasticity. Previous studies show that most neurotransmitters stimulate cyclic GMP levels by the activation of nitric oxide synthase (NOS). In this study, we report that in primary cell cultures from the cerebellum of neuronal NOS knockout mice, norepinephrine stimulates an increase in cyclic GMP content. This increase is seen in both granule cell and astrocyte cultures and is not blocked by inhibitors of NOS or by inhibition of soluble guanylyl cyclase. These results suggest a novel pathway by which norepinephrine enhances cyclic GMP levels in the nervous system.
A Closer Look at … Networks and Information Access

In the movie Brazil, Robert DeNiro plays a rogue repairman who comes to rescue the unwary from snarls in wiring and ducts caused by an unresponsive government agency called Central Services. Librarians using electronic networks for information access may wish for similar assistance; prying open the network's wiring box, even metaphorically, can be a daunting (though rewarding) experience.
Exchange and condensation of chloro and methoxyl groups between monomethylphosphino and methyl-substituted silyl or germyl moieties

Abstract The room-temperature reaction between CH 3 PCl 2 and (CH 3 ) x M (OCH 3 ) 4−x , where M = Si with x = 2 or 3, or M = Ge with x = 2, exhibits rapid exchange of chloro methoxyl groups between the starting compounds followed by condensation of the phosphorus moieties to give CH 3 (O)P units connected by PP bonds in the resulting oligomers. When CH 3 P(OCH 3 ) 2 is reacted with (CH 3 ) xitx SiCl 4− x for x = 2 or 3, there is no rapid exchange of chloro and methoxyl groups between the reagents but instead the major observed reaction is a slower condensation of the phosphorus moieties, a process which is necessarily accompanied by a transfer of methoxyl groups from the phosphino to the silyl moiety. In the case of CH 3 P(OCH 3 ) 2 plus (CH 3 ) 2 GeCl 2 , there is essentially no reaction in 2 weeks at room temperature except for a slow rearrangement of the phosphorus compound to (CH 3 ) 2 P(O)OCH 3 .
Atrial Repolarization—Its Importance in Clinical Electrocardiography

A complete study of the electrical effects of the atrial repolarization is made, since it seems that such effects are often inadequately considered in the routine daily interpretation of electrocardiograms. The alterations of the atrial repolarization are classified as follows: (1) primary, related to ischemia or injury of the atria, and hypersympathetic activity, (2) secondary, when appearing with modifications of the atrial activation, in cases of dilatation, hypertrophy, or intra-atrial block. The electrocardiographic changes produced by hypersympathetic activity are characterized by a P-PR junction (Ja) in the isoelectric line, descending P-R segment, depressed J point, and ascending S-T segment. The P-R and S-T segments have concordant deviations, which means that they behave as "arcs of a same circumference." The record of these electrical events is made in such a manner that the tracing can be morphologically compared to an anchor. An S-T depression has no pathologic significance whenever it is pre...
Effects of medium conditioned by retinal pigmented epithelial cells on neurotransmitter phenotype in retinoblastoma cells

Abstract We previously reported that medium conditioned by retinal pigmented epithelial cells can induced cellular differentiation in human retinoblastoma cells. Extensive neurite outgrowth, increased expression of neuronal marker molecules and decreased expression of glial marker molecules are characteristic of the differentiated phenotype. In the studies described here, we examine whether modulations in the expression of potential neurotransmitter molecules, catecholamines and indolealkyl amines, might be associated with the differentiation of retinoblastoma cells. Concentrations of serotonin, 5-hydroxyindoleacetic acid, 3-methoxytyrosine, homovanillic acid, and 3-methoxy-4-hydroxyphenylacetic acid in extracts of differentiated and undifferentiated retinoblastoma cells were assessed by HPLC. The results show that serotonin and its metabolite, 5-hydroxyindoleacetic acid, are characteristically present in undifferentiated cells. Dopa metabolites, 3-methoxytyrosine, homovanillic acid and 3-methoxy-4-hydroxyphenylacetic acid, are uniquely present in differentiated cells. It appears that differentiation of retinoblastoma cells induced by factors secreted by retinal pigmented epithelial cells involves a switch from a serotonergic phenotype to one dominated by metabolites of dopa. These findings may provide clues about the factors that control retinoblastoma cells and metastasis.
Evaluation of Penicillium mycotoxins for activity in stored-product Coleoptera.

The mycotoxins ochratoxin A, citrinin, rubratoxin B, patulin, penicillic acid and oxalic acid were fed to Tribolium confusum, Lasioderma serricorne and Attagenus megatoma in whole wheat flour. Penicillic and oxalic acids were not toxic to these insects at any concentration tested. Ochratoxin A and citrinin inhibited larval growth of A. megatoma at 10 and 1000 ppm, respectively, but rubratoxin B had no effect. Citrinin and rubratoxin B inhibited larval growth of T. confusum and L. serricorne at 1000 ppm only. Patulin inhibited growth of T. confusum at 1000 ppm both with and without yeast supplementation of the diet. L. serricorne larval growth slowed when patulin (at all concentrations) but no yeast was in the diet. Larval development time was increased whenever larval growth rates were inhibited. Reproduction of T. confusum was decreased by citrinin, patulin and ochratoxin A. L. serricorne reproduction was affected only by citrinin.
Liquid CO2 displacement of water in a dual-permeability pore network micromodel.

Permeability contrasts exist in multilayer geological formations under consideration for carbon sequestration. To improve our understanding of heterogeneous pore-scale displacements, liquid CO2 (LC...
Keeping quiet: Self-silencing and its association with relational and individual functioning among adolescent romantic couples

This study examined the relationships between self-silencing and relational and individual functioning among adolescent romantic couples. Adolescent couples (N = 211) completed questionnaires and participated in a videotaped conflict interaction. High self-silencers reported conceding more to their partner during a conflict, poorer global communication within their romantic relationships, and greater experiences of depressive symptomatology. Partners of self-silencers reported more frustration and discomfort when interacting with the self-silencing member. Although significant actor and partner effects were not found between relationship satisfaction and self-silencing, correlation analyses by gender revealed a significant negative correlation between self-silencing and relationship satisfaction among adolescent girls. Self-silencing is related to multiple aspects of adolescent romantic relationships including communication patterns and the quality of relational and individual functioning.
Efficacy of linaclotide for patients with chronic constipation.

Background & Aims Linaclotide is a minimally absorbed peptide agonist of the guanylate cyclase-C receptor that stimulates intestinal fluid secretion and transit and reduces pain in animal models. We assessed the safety and efficacy of a range of linaclotide doses in patients with chronic constipation. Methods We performed a multicenter, double-blind, placebo-controlled, parallel-group study of 310 patients with chronic constipation. Patients were randomly assigned to groups given 75, 150, 300, or 600 μg oral linaclotide or placebo once daily for 4 weeks. Symptom assessments included spontaneous bowel movements (SBMs), complete SBMs, stool consistency, straining, abdominal discomfort, and bloating. Severity of constipation, adequate relief of constipation, global relief of constipation, treatment satisfaction, quality of life, adverse events, clinical laboratory data, and electrocardiogram results were assessed. Results All doses of linaclotide improved the weekly rate of SBM (primary end point) compared with placebo; the increases in overall weekly number of SBMs from baseline were 2.6, 3.3, 3.6, and 4.3 for linaclotide doses of 75, 150, 300, and 600 μg, respectively, compared with 1.5 for placebo ( P ≤ .05 for each pair-wise comparison of a linaclotide dose to placebo). Likewise, linaclotide significantly improved the weekly rate of complete SBM, stool consistency, straining, abdominal discomfort, bloating, global assessments, and quality of life. The most common and only dose-related adverse event was diarrhea (only 6 patients discontinued treatment because of diarrhea). Conclusions Linaclotide therapy was associated with few adverse events and produced rapid and sustained improvement of bowel habits, abdominal symptoms, global relief, and quality of life in patients with chronic constipation.
Flame Spectrograms: I. Common Metals

Flame spectrophotometry is firmly established as an accurate, rapid, convenient and versatile method of analysis. More than 50 elements may be determined, and of these at least 30 have detectabilities of 1 ppm or less. Accuracy is commonly better than ±1%. Ease and speed of manipulation are outstanding, being based on direct aspiration of liquid samples into a flame, and on direct and instantaneous photometric reading of intensity. Flame photometric analysis ideally complements spectrographic analysis and, finally, it is relatively inexpensive.
The complete intersection locus of certain ideals

and dimension d. The most primitive quantities attached to an ideal Z are its height, ht(Z), and its minimum number of generators, u(Z). The fundamental relation between ht(Z) and u(Z) is pro- vided by Krull’s theorem: (1) u(Z) > ht(Z). The case of equality is noteworthy enough and Z will be called a complete intersec- tion if it so happens. (Strictly, this terminology is used when the ideal is generated by a regular sequence, but the two notions coincide in what will be our standard con- text - that of Cohen-Macaulay rings.) To bridge the gap between o(Z) and ht(Z) several other measures have been in- troduced. We single out: (i) ara(Z) = arithmetical rank of Z : = the least integer I such that the radical of Z is the radical of an r-generated ideal. (ii) I(Z) = analytic spread of Z := Krull dimension of the algebra @I’@
A level set simulation of dendritic solidification of multi-component alloys

A level set method combining features of front tracking methods and fixed domain methods is presented to model microstructure evolution in the solidification of multi-component alloys. Phase boundaries are tracked by solving the multi-phase level set equations. Diffused interfaces are constructed from these tracked phase boundaries using the level set functions. Based on the assumed diffused interfaces, volume-averaging techniques are applied for energy, species and momentum transport. Microstructure evolution in multi-component alloy systems is predicted using realistic material parameters. The methodology avoids the difficulty of parameter identification needed in other diffused interface models, and allows easy application to various practical alloy systems. Techniques including fast marching, narrow band computing and adaptive meshing are utilized to speed up computations. Several numerical examples are considered to validate the method and examine its potential for modeling solidification of practical alloy systems. These examples include two- and three-dimensional solidification of a binary alloy in an undercooled melt, a study of planar/cellular/dendritic transition in the solidification of a Ni-Cu alloy, and eutectic and peritectic solidification of an Fe-C system. Adaptive mesh refinement in the rapidly varying interface region makes the method practical for coupling the microstructure evolution at the meso-scale with buoyancy driven flow in the macro-scale, which is shown in the solidification of a Ni-Al-Ta ternary alloy.
Finite element modeling of the transient response of smart structures

A finite element (FE) formulation is presented for modeling the dynamical response of smart structures with embedded piezoelectric ceramic devices subjected to transient loading. The FEM formulation presented is based on a variational principle using the concept of virtual work. An unconditionally stable method ((alpha) -method) is utilized for the direct integration of the equations of motion and can be put in the form of a 3-step linear multistep method of second order equations. A thin cantilever plate with piezoelectric devices is investigated to show the feasibility of the analysis and numerical simulation. The code employs 20 node isoparametric 3D piezoelectric elements, flat-shell elements and transition elements at the interface of the piezoelectric devices and the plate. Under a given external loading, the structure and the embedded sensors deform and the voltage response of the sensor can be calculated as a function of time. Such calculations can be useful as a design tool for smart structures.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
DNA oligomers containing site-specific and stereospecific exocyclic deoxyadenosine adducts of 1,2,3,4-diepoxybutane: synthesis, characterization, and effects on DNA structure.

1,2,3,4-Diepoxybutane (DEB) is a carcinogenic metabolite of 1,3-butadiene (BD), an important industrial and environmental chemical present in urban air and in cigarette smoke. DEB is considered the ultimate carcinogenic species of BD because of its potent genotoxicity and mutagenicity attributed to its ability to form DNA−DNA cross-links and exocyclic nucleoside adducts. Mutagenesis studies suggest that DEB adducts formed at adenine bases may be critically important, as it induces large numbers of A → T transversions. We have recently identified three types of exocyclic DEB-dA lesions: N6,N6-(2,3-dihydroxybutan-1,4-diyl)-2′-deoxyadenosine (N6,N6-DHB-dA), 1,N6-(2-hydroxy-3-hydroxymethylpropan-1,3-diyl)-2′-deoxyadenosine (1,N6-γ-HMHP-dA), and 1,N6-(1-hydroxymethyl-2-hydroxypropan-1,3-diyl)-2′-deoxyadenosine (1,N6-α-HMHP-dA) [Seneviratne, U., et al. (2010) Chem. Res. Toxicol. 23, 118−133]. In the work presented here, a postsynthetic methodology for preparing DNA oligomers containing stereospecific and site-s...
Using a web-based project process throughout the software engineering curriculum

In order to facilitate the study and use of software process, which is essential to the education of future software professionals, a standard and tailorable project process has been developed over the last five years at Texas Tech University for use in both undergraduate and graduate curricula, with a total 12 courses involved. The process is entirely web-based, and includes a complete set of HTML document templates in order to facilitate the creation of project artifacts which are posted to the course web page. This method enhances communication between team members, including distance education students, and between the project team and client. The project process has received positive feedback from all stakeholders involved.This paper discusses the benefits of the web-based project process, its relation to curriculum models, and plans for a more formal assessment of the process. The portability of process to other institutions is also discussed, with an example provided.
Relationship Between Chemical-Induced Fragile Sites and Chromosomal Breakpoints in Malignant Cells in Children

Many fragile sites in the human genome occur at or near chromosomal breakpoints reportedly involved in translocations of DNA material in neoplastic cells. This fact has led some investigators to postulate that fragile sites have a pathogenic role in human neoplasia. To learn whether caffeine-induced fragile sites relate to breakpoints found in the neoplastic cells of an individual patient, we studied lymphocytes from the peripheral blood of 32 patients in remission from malignant disease. Lymphocytes were cultured in medium containing either 5-Fluoro-2′-deoxyuridine (FdU) or FdU plus caffeine, and G-banded mataphases were examined for nonrandom breaks. Analyses of completely G-banded malignant cell chromosomes from 31 of the 32 patients were available for comparison. In only once case, a 5-year-old child with acute lymphoblastic leukemia, did a caffeine-induced fragile site (1q44) coincide with a breakpoint in the neoplastic cells [dup(1)(q21 $ q44)]. Our findings suggest that chromosomal abnormalities in...
Properties of a structurally and functionally altered form of creatine kinase produced in solutions containing chloride and nitrate.

Abstract Rabbit skeletal muscle creatine kinase is inactivated when stored at −17 °C in the presence of either chloride or nitrate. Other anions are not effective. Associated with the inactivation is an altered electrophoretic mobility and the loss of four out of the eight titratable thiol groups in the dimeric catalytic protein of molecular weight 82,600. The altered inactive form is separated from the native active enzyme by electrofocusing, and its catalytic activity is restored by treatment with 2-mercaptoethanol. Gel electrophoresis in the presence and absence of 2-mercaptoethanol establishes that solutions of the inactive enzyme are heterogeneous, containing mostly a protomeric polypeptide of molecular weight 41,000, but also significant amounts of disulfide-linked dimers, trimers, and tetramers. Sedimentation equilibrium analysis confirms the existence of higher molecular weight aggregates along with the preponderant protein species of molecular weight 43,000.
Doppler shift in the frequency of inertial waves observed in moored spectra

Abstract In the moored temperature spectra presented by White and Evans (in press), the inertial spectral peaks were found consistently at frequencies (σ) slightly higher than the local inertial frequency ƒ . Moreover, evidence was reported which suggested that the observed frequency shift ( σ−ƒ ) was due to a positive Doppler shifting of the frequency of the inertial wave by the zonal mean flow (μ0) past the moored sensors. If this be so, then the frequency difference should equal μ0k, where k is the zonal inertial wavenumber. To test this possibility, appeal is made to some values of the mean zonal geostrophic flow and the zonal wavenumber of inertial waves observed in the North Equatorial Current System of the Pacific. With these data the expected Doppler shift μ0k is calculated which gives a value that compares favorably with the observed frequency shift. The influence of the Doppler shift upon the shape of moored power spectra and its effect upon spectral coherence is also discussed.
Labeling of Rh antibodies on solid-phase protein A

Rh0(D) antibodies which retain immune specificity after radiolabeling were prepared by a procedure which does not require IgG isolation from serum, requires 10-fold less isotope than conventional techniques and yields antibody solutions of defined composition. The method involves radioiodination of IgG on immobilized protein A, depends on employing human red cells reduced in surface cytophilic IgG, and exploits the inability of goat IgG to interact with Staphylococcus aureus protein A. The technique concentrates IgG by affinity adsorption and should prove useful in preparing radiolabeled alloantibodies from dilute human antisera and for red cell autoantibodies.
Aceto-coenzyme A-kinase and the Condensing Enzyme in the Two-spotted Spider Mite

ALTHOUGH earlier reports1 indicate that the enzymes necessary for the utilization of hexose phosphate through the Embden–Meyerhof and the hexose monophosphate pathways are present in the two-spotted spider mite, Tetranychus telarius (L.), little attention has been given to the presence of tricarboxylic acid cycle enzymes in these organisms. Moreover, since in most animals' tissues, as known so far, the tricarboxylic acid cycle is responsible for the final oxidation of organic acids produced during the metabolism of carbohydrates, fats and proteins2, it was thought pertinent to demonstrate the presence of some of the enzymes of tricarboxylic acid cycle in the mite. Towards this end the evidence for the presence of aceto-coenzyme A-kinase and condensing enzyme in the dialysed acetone powder extracts of the mite has been obtained.
Relational cognition complexity and relational communication in personal relationships.

This investigation examined the influence of individual differences in relational cognition complexity on patterns of relational communication in personal relationships. Relational cognition complexity of members of married couples was assessed via the Relational Cognition Complexity Instrument (RCCI). Couples discussed topics which were salient and non‐salient for their relationship and the recorded conversations were transcribed and reliably coded utilizing the Relational Communication Coding Scheme. RCCI scores were not related to the relative distribution of an individual partner's dominant, submissive and neutral relational communication moves. The male partner's RCCI score was moderately positively related to the couple's transactional redundancy, especially during discussions of salient topics. Couples with a male partner scoring relatively high on the RCCI were characterized by greater mutual expression of support and lower mutual expression of non‐support, when compared to couples with a male sco...
Practical fracture treatment. Fourth edition

Abstract Arthroscopy: The Journal of Arthroscopic and Related surgery, Vol 19, No 4 (April), 2003: pp 446–450
Crystal Structures of a Family of New Copper(I) Cyanide Complexes of Thiourea and Substituted Thioureas.

The syntheses and crystal structures of a family of silver cyanide complexes of thiourea and substituted thioureas are reported. The sulfur ligands include thiourea (tu), 1-methyl-2-thiourea (mtu), 1,3-dimethyl-2-thiourea (dmtu), 1,1,3,3-tetramethyl-2-thiourea (tmtu), and 2-imidazolidinethione (N,N‘-ethylenethiourea, etu). Synthesis was effected by dissolving AgCN in an aqueous solution of ligand. Two different complexes were obtained by the reaction of AgCN with tu. Complex 1a: (AgCN)(tu), monoclinic, P21/c, a = 9.3851 (6) A, b = 8.2782 (5) A, c = 7.1178 (5) A, β = 94.591 (1)°, and Z = 4. Complex 1b: (AgCN)(tu)2, triclinic, P1, a = 7.9485 (14) A, b = 9.431 (2) A, c = 12.771 (2) A, α = 85.695 (3)°, β = 81.210 (4)°, γ = 77.987 (2)°, and Z = 4. Complex 2: (AgCN)(mtu), triclinic, P1, a = 4.113 (2) A, b = 9.472 (4) A, c = 9.679 (4) A, α = 113.918 (5)°, β = 98.188 (6)°, γ = 97.725 (6)°, and Z = 2. Complex 3 (AgCN)2(dmtu)2, monoclinic, P21/m, a = 7.1482 (7) A, b = 14.776 (2) A, c = 7.3366 (7) A, β = 92.418...
AGU updating position statement on climate change: Call for comments

Since 1982, AGU has developed and maintained position statements to provide scientific expertise on significant policy issues. All members are encouraged to help inform the policy-making process in their home and research locales with thoughtful presentation of scientific viewpoints. To aid in this task, AGU members may use an AGU position statement as an official statement of the Union in discussion with policy makers. Position statements are published on the AGU science policy Web page, where they can be viewed by scientists, policy makers, media, and the general public.
A sensitive microassay for protein in cells cultured on collagen.

Abstract A microassay for protein that is linear from 0.1 to 5 μg of protein and does not detect collagen has been developed. The assay is based on the ability of bromosulphophthalein (BSP) to form BSP-protein complexes which precipitate at low pH. Maximum precipitation occurs when 30 or more BSP molecules are bound per albumin molecule. Collagen is not detected because too little BSP binds to this protein to precipitate it. This assay should be of great value to those who grow dispersed cell cultures on a collagen substrate.
Two-dimensional complex Fourier transform via the Radon transform.

A hybrid system has been constructed to perform the complex Fourier transform of real 2-D data. The system is based on the Radon transform; i.e., operations are performed on 1-D projections of the data. The projections are derived optically from transmissive or reflective objects, and the complex Fourier transform is performed with SAW filters via the chirp transform algorithm. The real and imaginary parts of the 2-D transform are produced in two bipolar output channels.
A novel method to quantify sphingosine 1-phosphate by immobilized metal affinity chromatography (IMAC)

Sphingosine 1-phosphate (S1P), a lysophospholipid mediator that signals through G protein-coupled receptors, regulates a wide plethora of biological responses such as angiogenesis and immune cell trafficking. Detection and quantification of S1P in biological samples is challenging due to its unique physicochemical nature and occurrence in trace quantities. In this report, we describe a new method to selectively enrich S1P and dihydro-S1P from biological samples by the Fe3+ gel immobilized metal affinity chromatography (IMAC). The eluted S1P from IMAC was dephosphorylated, derivatized with o-phthalaldehyde (OPA), and detected by high-performance liquid chromatography (HPLC) coupled to a fluorescence detector. IMAC purification of S1P was linear for a wide range of S1P concentration. Using this assay, secretion of endogenous S1P from endothelial cells, fibroblasts and colon cancer cells was demonstrated. We also show that dihydro-S1P was the major sphingoid base phosphate secreted from HUVEC over expressed with Sphk1 cDNA. Pharmcological antagonists of ABC transporters, glyburide and MK-571 attenuated endogenous S1P release. This assay was also used to demonstrate that plasma S1P levels were not altered in mice deficient for ABC transporters, Abca1, Abca7 and Abcc1/Mrp1. IMAC-based affinity-enrichment coupled with a HPLC-based separation and detection system is a rapid and sensitive method to accurately quantify S1P.
Quantitation of human T-lymphocytes in blood: use of automatic smearing instrument for preparing fixed slides of E-rosettes.

Human T-lymphocytes were enumerated in 10 normal volunteers and 4 patients by a new method utilizing an automatic smearing instrument to prepare permanent fixed slides of E-rosettes. The results were compared to the commonly employed hemocytometer method. Results obtained using the smearing instrument were similar to those obtained by the hemocytometer method with the added advantages of permanent record, convenience of quantitation, and precise morphological identification of rosette-forming cells. As opposed to well-preserved E-rosettes obtained by the automatic smearing instrument, hand-made smears showed disruption of E-rosettes.
Is Education the Key to Global Economic Competitiveness

Contemporary test-based reforms are often grounded in the claim that test performance is the key to international economic competitiveness. However, this oft-repeated assertion lacks empirical support. According to the World Economic Forum, the United States' recent loss of economic competitiveness standing is due to macroeconomic instability rather than to a lack of workforce skills and knowledge. In contrast to the claims of President Obama and Secretary Duncan, the nation has no shortage of qualified job applicants. There are, on average, three qualified applicants for every high tech job. Furthermore, 80% of projected jobs require only technical or on-the-job training. The vast majority do not require the skills measured by contemporary accountability schemes. For example, only 5% require any math beyond basic operations. Educators must continue to focus on equality of educational opportunities for all children and, as contrasted with narrow economic rationales, embrace a broader vision of the purpose...
Clinical review: The human experience with ghrelin administration.

Context: Ghrelin is an endogenous stimulator of GH and is implicated in a number of physiological processes. Clinical trials have been performed in a variety of patient populations, but there is no comprehensive review of the beneficial and adverse consequences of ghrelin administration to humans. Evidence Acquisition: PubMed was utilized, and the reference list of each article was screened. We included 121 published articles in which ghrelin was administered to humans. Evidence Synthesis: Ghrelin has been administered as an infusion or a bolus in a variety of doses to 1850 study participants, including healthy participants and patients with obesity, prior gastrectomy, cancer, pituitary disease, diabetes mellitus, eating disorders, and other conditions. There is strong evidence that ghrelin stimulates appetite and increases circulating GH, ACTH, cortisol, prolactin, and glucose across varied patient populations. There is a paucity of evidence regarding the effects of ghrelin on LH, FSH, TSH, insulin, lipo...
Ab initio survey of the electronic structure of tetrahedrally bonded phases of silicon

We present an ab initio study of the electronic structure of a number of high-pressure metastable phases of silicon with tetrahedral bonding. The phases studied include all experimentally determined phases that result from decompression from the metallic $\ensuremath{\beta}$-Sn phase, namely, the BC8 (Si III), hexagonal diamond (Si IV), and R8 (Si XII) phases. In addition to these we have also studied the hypothetical ST12 structure that is found upon decompression from $\ensuremath{\beta}$-Sn in germanium. We find that the local-density approximation incorrectly predicts the R8 phase to be semimetallic and that the quasiparticle spectrum exhibits a band gap. The effective masses found in R8 suggest that R8 may be useful for high-mobility applications. In addition, the ST12 phase is found to have a large density of electronic states at the band edge which could lead to interesting superconducting behavior.
Changes in long-term sebum production from isotretinoin therapy

Sebum production has been measured in twenty patients in whom 13- cis -retinoic acid therapy had been discontinued for at least 20 weeks. While sebum production had returned to pretreatment levels by 30 weeks in seven subjects, 30% to 80% reduction in sebaceous gland activity was still present for as long as 80 weeks in eight subjects. Four of these eight patients, who were followed for more than a year, still had marked sebaceous inhibition when last tested. The prolonged remission seen in patients with nodulocystic acne may be related in part to continued sebaceous gland inhibition in some patients, but it obviously is not the only factor responsible for the long-term improvement that is seen.
A low power 1.8–2.6 dB noise figure, SiGe HBT wideband LNA for multiband wireless applications

We present a wideband, very low power, Low Noise Amplifier (LNA) implemented in Silicon-Germanium Heterojunction Bipolar Transistor (SiGe HBT) technology. This SiGe LNA is broadband, covering the frequency range of 5–11 GHz, and achieves a peak gain of 19.2 dB and 66% fractional bandwidth. The LNA exhibits a Noise Figure (NF) of 1.8–2.6 dB across band and consumes only 9 mW of power. To the authors' knowledge, this is the lowest NF for a wideband LNA reported in a commercially-available silicon-based process, and was realized by utilizing inductive peaking, device layout optimization, and shunt capacitive feedback.
Infrared spectral emissivities of cobaltoxide and nickeloxide films

Abstract A method is described for the measurement of the spectral emissivity at high temperatures of coatings deposited on electrically conducting substrates. The application of this method is illustrated by measurement of the emissivities of cobaltoxide and nickeloxide films supported on platinum. The results are discussed in terms of the temperature, film thickness, and optical properties of the films.
The role of seepage in constructed wetlands receiving agricultural tile drainage

Constructed wetlands positioned in the landscape between row crop agriculture and surface waters can be used to intercept tile drainage and serve as agricultural waste water detention basins. A potential exit pathway in constructed wetlands for detained water and possibly NO3 -N is via seepage through and under an earthen berm. The objective of this study was to determine if seepage was an important pathway for NO3 -N transport from two constructed wetlands receiving tile drainage from adjacent agricultural land (wetland A, surface area of 0.6 ha; wetland D, 0.78 ha). A mean apparent hydraulic conductivity (K) was calculated (10.8 cm h 1 , range 8.2‐14.3 cm h 1 ) using empirical water budgets. Using Darcy’s law, which included the apparent hydraulic conductivity, effective seepage area and daily hydraulic gradient measurements, daily seepage volumes for both wetlands were calculated for the 1997 water year. Total seepage volumes for wetlands A and D were 26 and 22 million liters, respectively, for the 1997 water year, which represented 47 and 27% of the total inlet flow. The amount of NO3 -N exiting wetlands A and D in seepage water was estimated to be 61 and 25 kg N, respectively, and represented 10 and 4% of the total inlet NO3 -N load. Seepage connected the wetland with the riparian buffer strip and transported NO3 -N to populations of denitrifiers deeper in the sediment profile and outside the wetland perimeter, thereby enhancing overall NO3 -N removal efficiencies. © 2000 Elsevier Science B.V. All rights reserved.
Dynamics of Single Cavitation Bubble Oscillation Inside an Elastic Tube

Understanding the dynamics of bubble oscillation in tissue-constrained media such as within blood vessels is important for many current and potential therapeutic ultrasound applications. Cavitation is a primary mechanism responsible for vessel rupture and tissue injury in shock wave lithotripsy [1]. In sonoporation cavitation can be used to increase permeability of biological membranes. Particularly, ultrasound contrast agents are widely used for imaging of blood vessels and for enhancement of ultrasound-mediated gene delivery [2]. Modeling of non-linear oscillations of bubbles in acrylic capillaries in a high-intensity focused ultrasound field revealed a clear dependence of bubble displacement and fragmentation on tube diameter [3]. However, the effect of elastic boundary on bubble dynamics may differ significantly from that of a rigid boundary [4, 5]. In this study, experimental investigation of the dynamics of bubble oscillation in an elastic tube was performed and preliminary results from tubes of different inner diameters are presented.Copyright © 2007 by ASME
Selective inhibition of MBNL1–CCUG interaction by small molecules toward potential therapeutic agents for myotonic dystrophy type 2 (DM2)

Myotonic dystrophy type 2 (DM2) is an incurable neuromuscular disease caused by expanded CCUG repeats that may exhibit toxicity by sequestering the splicing regulator MBNL1. A series of triaminotriazine- and triaminopyrimidine-based small molecules (ligands 1-3) were designed, synthesized and tested as inhibitors of the MBNL1-CCUG interaction. Despite the structural similarities of the triaminotriazine and triaminopyrimidine units, the triaminopyrimidine-based ligands bind with low micromolar affinity to CCUG repeats (K(d) ∼ 0.1-3.6 µM) whereas the triaminotriazine ligands do not bind CCUG repeats. Importantly, these simple and small triaminopyrimidine ligands exhibit both strong inhibition (K(i) ∼ 2 µM) of the MBNL1-CCUG interaction and high selectivity for CCUG repeats over other RNA targets. These experiments suggest these compounds are potential lead agents for the treatment of DM2.
Energy Analysis of Single-Hop Communication Systems

In this paper we analyze the cutoff rate of a single-hop communication system taking into account the energy of the transmitter and receiver. An approximate formula is derived for the rate that achieves minimum energy consumption. We also present numerical results for Reed-Solomon (RS) codes over the AWGN channel. The results show that as the contribution of processing power increases, the optimal code rate to achieve the minimum energy consumption increases. Beside the AWGN channel, we also analyze the cutoff rate over a Rayleigh flat fading channel using the cutoff rate for binary frequency shift keying with noncoherent detection
Excitability of Type II Cochlear Afferents

Two types of sensory hair cells in the mammalian cochlea signal through anatomically distinct populations of spiral ganglion afferent neurons. The solitary inner hair cell ribbon synapse uses multivesicular release to trigger action potentials that encode acoustic timing, intensity, and frequency in each type I afferent. In contrast, cochlear outer hair cells (OHCs) have a far weaker effect on their postsynaptic targets, the type II spiral ganglion afferents. OHCs typically release single vesicles with low probability so that extensive summation is required to reach the relatively high action potential initiation threshold. These stark differences in synaptic transfer call into question whether type II neurons contribute to the cognitive perception of sound. Given the sparse and weak synaptic inputs from OHCs, the electrical properties of type II afferents are crucial in determining whether synaptic responses can sum to evoke an action potential to convey information to the cochlear nucleus. In the present work, dual-electrode recordings determined that type II afferents of rats have length constants that exceed the length of the distal, spiral process, enabling spatial summation from widespread OHCs. Focal application of tetrodotoxin localized the spike initiation zone to the type II proximal, radial process, near the spiral ganglion, in agreement with the high voltage threshold measured in the spiral process. These measured membrane properties were incorporated into a compartmental model of the type II neuron to demonstrate that neurotransmitter release from at least six OHCs is required to trigger an action potential in a type II neuron.
Repeated evolution of tricellular (and bicellular) pollen.

Premise of study Male gametophytes of seed plants are sexually immature at the time they are dispersed as pollen, but approximately 30% of flowering plants have tricellular pollen containing fully formed sperm at anthesis. The classic study of Brewbaker (1967: American Journal of Botany 54: 1069-1083) provided a powerful confirmation of the long-standing hypothesis that tricellular pollen had many parallel and irreversible origins within angiosperms. We readdressed the main questions of that study with modern comparative phylogenetic methods. Methods We used our own and more recent reports to greatly expand the Brewbaker data set. We modeled trait evolution for 2511 species on a time-calibrated angiosperm phylogeny using (1) Binary State Speciation and Extinction (BiSSE), which accounts for the effect of species diversification rates on character transition rates and, (2) the hidden rates model (HRM), which incorporates variation in transition rates across a phylogeny. Key results Seventy percent of species had bicellular pollen. BiSSE found a 1.9-fold higher bicellular to tricellular transition rate than in the reverse direction, and bicellular lineages had a 1.8-fold higher diversification rate than tricellular lineages. HRM found heterogeneity in evolutionary rates, with bidirectional transition rates in three of four rate classes. Conclusions The tricellular condition is not irreversible. Pollen cell numbers are maintained at intermediate frequencies because lower net diversification rates of tricellular lineages are counterbalanced by slower state shifts to the bicellular condition. That tricellular lineages diversify slowly and give rise to bicellular lineages slowly reflects a linkage between the evolution of sporophyte lifestyles and the developmental lability of male gametophytes.
Augustine and the Liberal Arts.

In an early dialogue, On Order, Augustine sets out a program for thinking about thinking. Through such reflections, students attain self-knowledge and prepare for philosophical inquiry. The liberal arts are useful for this project, insofar as they provide opportunities for thinking, yet they are not ultimately necessary. I suggest that On Order’s program, correctly understood, provides a rationale for Augustine’s beginning but never completing a set of works on the seven liberal arts, and that his approach has contemporary relevance. Current discussions of the liberal arts move between concerns for particular content, which after a canon war may seem political or arbitrary, and useful skills, which reduce the liberal arts to quasi-vocational programs. Augustine’s focus on rational activity escapes the content/skills dilemma and gives us a fresh perspective on the liberal arts’ value.
Two Genetic Forms of Hyperinsulinemic Hypoglycemia Caused by Dysregulation of Glutamate Dehydrogenase

Glutamate dehydrogenase (GDH) has recently been shown to be involved in two genetic disorders of hyperinsulinemic hypoglycemia in children. These include the hyperinsulinism/hyperammonemia syndrome caused by dominant activating mutations of GLUD1 which interfere with inhibitory regulation by GTP and hyperinsulinism due to recessive deficiency of short-chain 3-hydroxy-acyl-CoA dehydrogenase (SCHAD, encoded by HADH1). The clinical manifestations of the abnormalities in pancreatic s-cell insulin regulation include fasting hypoglycemia, as well as protein-sensitive hypoglycemia. The latter is due to abnormally increased sensitivity of affected children to stimulation of insulin secretion by the amino acid, leucine. In patients with GDH activating mutations, mild hyperammonemia occurs in both the basal and protein-fed state, possibly due to increased renal ammoniagenesis. Some patients with GDH activating mutations appear to be at unusual risk of developmental delay and generalized epilepsy, perhaps reflecting consequences of increased GDH activity in the brain. Studies of these two disorders have been carried out in mouse models to define the mechanisms of insulin dysregulation. In SCHAD deficiency, the activation of GDH is due to loss of a direct inhibitory protein-protein interaction between SCHAD and GDH. These two novel human disorders demonstrate the important role of GDH in insulin regulation and illustrate unexpectedly important reasons for the unusually complex allosteric regulation of GDH.
Fine structure of electric field waveforms recorded at near and far distances from the lightning channel

We examine the shapes and relative magnitude of slow fronts and fast transitions in electric field waveforms of first return strokes in negative cloud-to-ground lightning recorded simultaneously at near and far distances from the lightning channel. The near and far field-measuring stations are located at Camp Blanding and in Gainesville, Florida, respectively, separated by a distance of about 45 km. A total of five return strokes had been recorded in 2007–2008, four of which were analyzed in detail (one was not suitable for analysis due to saturation of electric field waveform at the far station). The AM and GM zero-to-peak risetimes for four strokes were 7.2 µs and 6.6 µs, respectively, at the near station, and 7.0 µs and 6.5 µs, respectively, at the far station. The AM and GM 10-to-90% risetimes were 4.9 µs and 4.6 µs, respectively, at the near station, and 4.0 µs and 3.6 µs, respectively, at the far station. Three of the four first strokes exhibited the two distinct phases, the slow front and fast transition, in the initial rising portion of their electric field waveforms. For two return strokes the amplitude of the slow front was 49% of the peak at the near station and 44% of the peak at the far station, while for one it was 43% and 18% of the peak at the near and far stations, respectively. The AM and GM 10-to-90% risetimes of the fast transition for the three strokes were both 0.6 µs at the near station versus 0.9 µs at the far station. It is shown, via modeling, that the slow front in electric field waveforms at far distances is primarily due to the radiation field component, while at near distances it is composed of more or less equal contributions from all three components of electric field. For both measured and model-predicted waveforms, the durations of the slow front appear to be similar at near and far distances from the lightning channel.
Risk in Perspective: Insight and Humor in the Age of Risk Management

A method for estimating long-term exposures from short-term measurements is validated using data from a recent EPA study of exposure to fine particles. The method was developed a decade ago but long-term exposure data to validate it did not exist until recently. In this article, exposure data from repeated visits to 37 persons over 1 year (up to 28 measurements per person) are used to test the model. Both fine particle mass and elemental concentrations measured indoors, outdoors, and on the person are examined. To provide the most stringent test of the method, only two single-day distributions are randomly selected for each element to predict the long-term distributions. The precision of the method in estimating the long-term geometric mean and geometric standard deviation appears to be of the order of 10%, with no apparent bias. The precision in estimating the 99th percentile ranges from 19% to 48%, again without obvious bias. The precision can be improved by selecting a number of pairs of single-day distributions instead of just one pair. Occasionally, the method fails to provide an estimate for the long-term distribution. In that case, a repeat of the random selection procedure can provide an estimate. Although the method assumes a log-normal distribution, most of the distributions tested failed the chi-square test for log-normality. Therefore, the method appears suitable for application to distributions that depart from log-normality.
A General Test for Interaction Modification

How can measurements of population dynamics be used to deduce the mechanisms of interaction in an assemblage of species? We present a technique to use such measurements to distinguish among assemblages of species with no direct interactions, sets of species influenced predominantly by pairwise interactions, and communities with sig- nificant interaction modification. We define the interaction coefficients and show that their dependence on the population sizes of the various species reveals and pinpoints interactions. Our technique distinguishes non-additivity in the statistical sense from interaction mod- ification in the biological sense.