cssi/SciSciGPT-SciSciNet huggingface dataset:
Selecting labels for news document clusters

This work deals with determination of meaningful and terse cluster labels for News document clusters. We analyze a number of alternatives for selecting headlines and/or sentences of document in a document cluster (obtained as a result of an entity-event-duration query), and formalize an approach to extracting a short phrase from well-supported headlines/sentences of the cluster that can serve as the cluster label. Our technique maps a sentence into a set of significant stems to approximate its semantics, for comparison. Eventually a cluster label is extracted from a selected headline/sentence as a contiguous sequence of words, resuscitating word sequencing information lost in the formalization of semantic equivalence.
Analysis of thermal hysteresis protein hydration using the random network model.

Abstract The hydration of polar and apolar groups can be explained quantitatively, via the random network model of water, in terms of differential distortions in first hydration shell water–water hydrogen bonding angle. This method of analyzing solute induced structural distortions of water is applied to study the ice-binding type III thermal hysteresis protein. The analysis reveals subtle but significant differences in solvent structuring of the ice-binding surface, compared to non-ice binding protein surface. The major differences in hydration in the ice-binding region are (i) polar groups have a very apolar-like hydration. (ii) there is more uniform hydration structure. Overall, this surface strongly enhances the tetrahedral, or ice-like, hydration within the primary hydration shell. It is concluded that these two specific features of the hydration structure are important for this surface to recognize, and preferentially interact with nascent ice crystals forming in liquid water.
Memory consolidation and the amygdala: a systems perspective

The basolateral region of the amygdala (BLA) plays a crucial role in making significant experiences memorable. There is extensive evidence that stress hormones and other neuromodulatory systems activated by arousing training experiences converge in regulating noradrenaline-receptor activity within the BLA. Such activation of the BLA modulates memory consolidation via BLA projections to many brain regions involved in consolidating lasting memory, including the hippocampus, caudate nucleus, nucleus basalis and cortex. Investigation of the involvement of BLA projections to other brain regions is essential for understanding influences of the amygdala on different aspects and forms of memory.
Magneto-optical Rotation Spectra of Cytochrome c

MANY spectroscopic investigations have been reported on cytochrome c in defining its role in biochemical electron transport systems1,2. These include the ultra-violet and visible absorption measurements of Keilin and Hartree3 and the optical rotatory dispersion (ORD) data of Eichorn and Cairns4. In this laboratory, we have been investigating the application of the new technique of magneto-optical rotation spectroscopy5 to the examination of different oxidation states of the cytochrome c molecule. In this type of measurement, the optical rotations induced by an external magnetic field (Faraday effect) are obtained as a function of wave-length to provide a magneto-optical rotation (MOR) spectrum. The results for cytochrome c (Figs. 1–4) are quite pronounced and show large changes with the oxidation state of the molecule.
Management of the Failed Transurethral Resection of the Prostate

Transurethral resection of the prostate (TURP) is the gold standard for treatment of symptomatic benign prostatic enlargement. Failure of TURP and other similar procedures may occur when a patient has poor bladder emptying postoperatively or has persistent or de novo bothersome postoperative lower urinary tract symptoms. Reasons for failure include inadequate resection, clot retention, anesthesia-related side effects, postoperative pain, hypo- or acontractile bladder, and/or poor patient selection. Patients initially can be managed conservatively or proactively. When clinically significant storage or voiding dysfunction persists, evaluation is necessary and may include cystoscopy and/or urodynamics. Depending on the diagnosis and etiology, patients can then be managed with an array of therapies, including urethral catheterization, oral medications, intravesical botulinum A toxin, neuromodulation, or further surgery as indicated.
Crossing Francophone Boundaries: Beckett's Fictions

Although Samuel Beckett's œuvre is bilingual in French and English, his writing is generally considered to be the product of a single national identity... This article is available in Studies in 20th Century Literature: http://newprairiepress.org/sttcl/vol26/iss1/8 Crossing Francophone Boundaries: Beckett's Fictions
Erosive lichen planus of the vulva and vagina.

Abstract background Erosive lichen planus causes erosion of the vulva and vagina and characteristic oral lesions. Dyspareunia is usual, and vaginal stenosis may occur. This report highlights the clinical features and the response to medical therapy. Cases We report the case histories of three women who presented to the Vulvovaginal Disorders Clinic of the University of Iowa with long histories of dyspareunia and advanced vaginal scarring. In each case, the clinical diagnosis of erosive lichen planus was obvious but had not been made previously. All three women have responded well to topical treatment with tacrolimus 0.1% ointment. Conclusion Erosive lichen planus should be suspected in a case of vaginal erosion or narrowing. Surgical management is inappropriate when the mucosa is eroded. Inspection of the mouth may confirm the diagnosis.
Scanned bi-orthogonal radiographs as a source for 3D cephalometric data

We have developed a visualization environment, CEPH, for the analysis of plain film, biothogonally registered, head x-rays, i.e., cephalograms. Most importantly this program facilitates the collection of 3D landmark data from biorthogonal cephalogram pairs, i.e., correlated frontal and lateral images. To this end we have implemented tools for: contrast enhancement, image compression, morphological feature extraction, and grayscale shape recognition for automatic landmark detection. These data are useful for clinical craniofacial: (1) diagnosis, (2) treatment planning, (3) computed-assisted surgery, and (4) post-procedure follow-up. We are currently using the CEPH visualization environment to produce average landmark sets from the nearly 2000 'Bolton Standards' images. These images were collected for the Bolton-Brush Growth Study at Case Western Reserve University. Two dimensional landmark data captured from these images are universally recognized and used as diagnostic and treatment 'norms.' We are planning to make new three dimensional Bolton Standards data available this year. To this end we have scanned all of the Bolton Standards cephalograms at 2400 by 2400 resolution with 12 bits of grayscale information on a TDI scanner.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Methodological issues in international HR management research

Methodological issues can be particularly thorny considerations in international HR management research. If not addressed properly, they can severely undermine valid inferences and limit the ability to generalize to populations of interest. More generally, they can lead to unsound recommendations regarding the practice of international management. This article considers five such methodological issues: translation, conceptual, functional, and metric equivalence when assessment or survey questions are used in different languages and cultural contexts; the use of multiple, overlapping constructs and common methods bias; limitations of measures of internal-consistency reliability (coefficient alpha); sampling strategies; and non-response bias. The article defines each issue, identifies the implications of failure to address it, and suggests alternative strategies to ensure valid inferences.
Comparison of outcome of cardiac rehabilitation in black women and white women.

Coronary artery disease is the leading cause of death among black women in the United States. Black women also demonstrate a greater prevalence of coronary risk factors and a higher mortality after myocardial infarction than white women. To evaluate the clinical profile and outcome of black women in an urban-based cardiac rehabilitation program, 35 black women (aged 54 ± 13 years) and 47 white women (aged 57 ± 10 years) were prospectively studied. Black women had similar admitting diagnoses as white women, with recent myocardial infarction being the most common (37%). Coronary risk factors were more prevalent in black women than white women in the program: hypertension (71% vs 53%; p = 0.09), diabetes mellitus (46% vs 26%; p = 0.06), obesity (74% vs 49%; p
BIOMECHANICS AND ALGINIC ACID COMPOSITION DURING HYDRODYNAMIC ADAPTATION BY EGREGIA MENZIESII (PHAEOPHYTA) JUVENILES1

To investigate the possible link between cell wall alginic acid composition and tissue mechanics, juveniles of Egregia menziesii (Turn.) Aresch. were grown under controlled conditions in an outdoor flowing seawater system under three different force regimes. After 6–10 weeks of growth, tissue strength, breaking strain, modulus, toughness, work of fracture, and the percentage of polymannuronate, polyguluronate, and alternating sequences in the cell wall alginic acid were examined. The force regime had significant effects on all mechanical indices except toughness. Juveniles grown under high energy conditions (water velocity = 1.2 m · s−1) were about two times stronger, two times stiffer, and had a 1.5 times greater work of fracture than those from low energy conditions (<1 cm ·−1). Treatment effects on thallus strength and modulus were predicted from alginic acid composition data to test for the importance of this cell wall material in whole plant adaptation to hydrodynamic stress. However, the prediction that differences in alginic acid composition were responsible for differences in tissue mechanical properties was inconsistent with observations. Therefore, the hypothesis that alginates play a central role in structural adaptation could not be accepted.
Apomixis via recombination of genome regions for apomeiosis (diplospory) and parthenogenesis in Erigeron (daisy fleabane, Asteraceae)

Apomixis in daisy fleabanes (Erigeron annuus and E. strigosus) is controlled by two genetically unlinked loci that regulate, independently, the formation of unreduced female gametophytes (apomeiosis, diplospory) and autonomous seed formation (parthenogenesis). In this work, fully apomictic F2s were regenerated by crossing F1s bearing, separately, these two functional regions. Two triploid (3x = 2n = 27) highly diplosporous F1s served as seed parents to an aneuploid (2x + 1 = 2n = 19) meiotic pollen donor bearing four AFLP markers linked to parthenogenetic seed formation but producing only abortive embryos and endosperm. Of 408 hybrids, 21 (5.1%) produced seed. Nine of these putative apomicts were tetraploids (4x), likely combining an unreduced egg from the diplosporous seed parent and a haploid gamete from the pollen parent (3x + x). The other 12 hybrid apomicts were pentaploid, interpreted as arising from the fusion of an unreduced diplosporous egg with an unreduced sperm cell (3x + 2x). Analysis indicated that all but three of the 21 synthetic apomicts recombined markers linked to diplospory and parthenogenesis. In addition, three additional hybrids combined markers linked to the two functional regions but produced only aborted embryos. The apomicts varied in percentage of diplosporous ovules (4.7–95.3% of all ovules produced) and in percentage of ovules that developed into seed (3.8–58.0%). These results support the hypothesis that apomeiosis and autonomous seed formation are genetically distinct, and that the traits can be separated and recombined to create hybrids exhibiting apomixis at near wildtype levels.
Reprogramming of Intestinal Glucose Metabolism and Glycemic Control in Rats After Gastric Bypass

The resolution of type 2 diabetes after Roux-en-Y gastric bypass (RYGB) attests to the important role of the gastrointestinal tract in glucose homeostasis. Previous studies in RYGB-treated rats have shown that the Roux limb displays hyperplasia and hypertrophy. Here, we report that the Roux limb of RYGB-treated rats exhibits reprogramming of intestinal glucose metabolism to meet its increased bioenergetic demands; glucose transporter-1 is up-regulated, basolateral glucose uptake is enhanced, aerobic glycolysis is augmented, and glucose is directed toward metabolic pathways that support tissue growth. We show that reprogramming of intestinal glucose metabolism is triggered by the exposure of the Roux limb to undigested nutrients. We demonstrate by positron emission tomography-computed tomography scanning and biodistribution analysis using 2-deoxy-2-[18F]fluoro-D-glucose that reprogramming of intestinal glucose metabolism renders the intestine a major tissue for glucose disposal, contributing to the improvement in glycemic control after RYGB.
Confocal microscopy: A new tool for the study of the nail unit

Reflected light biomicroscopy has several limitations at magnifications sufficient for discerning cellular details in biologic materials. At least two problems are common: (1) the surface of the specimen may reflect large amounts of available light and (2) the important subsurface structures may be poorly reflective. For these reasons light microscopy is not useful to examine the nails; transillumination is not possible, and reflected light illumination results largely in reflection from the nail plate surface. We employed a new instrument, the real-time confocal microscope, which uses reflected light to section living tissue optically at various depths, to examine and image layers of the nail unit in vivo without stains or dyes. Nipkow Disk
Comparison of Solubilization of Hydrocarbons in (PEO-PPO) Diblock versus (PEO-PPO-PEO) Triblock Copolymer Micelles

Abstract The solubilization of hydrocarbons by micelles formed of diblock and symmetric triblock copolymers in water are compared in the framework of a mean-field theory of solubilization. The block copolymers contain poly(ethylene oxide) as the hydrophilic block and poly(propylene oxide) as the hydrophobic block and are designated as E X P Y E X or E W P Z (where E and P denote ethylene and propylene oxides and the subscripts denote the number of segments). In the presence of a variety of aromatic and aliphatic hydrocarbon solubilizates, the core radius, corona thickness, and aggregation number of the micelle and also the volume fraction of the hydrocarbon solubilized in the core are predicted. The calculations show that for identical molecular weights and block compositions, the diblock (E 200 P 64 ) copolymer micelles have a much larger core radius, corona thickness, aggregation number, and volume fraction of the hydrocarbon solubilized in the core compared with the symmetric triblock (E 100 P 64 E 100 ) copolymer micelles. In contrast, the diblock copolymer (E 100 P 32 ), having the same block composition but half the molecular weight of the symmetric triblock copolymer (E 100 P 64 E 100 ), gives rise to micelles having the same core radius, corona thickness, and volume fraction of the hydrocarbon solubilized as the micelles formed of the triblock copolymer, and an aggregation number twice that of the triblock copolymer micelle.
An L 2 Comparison Between the Bootstrap and the Empirical Edgeworth Expansion

The Bootstrap estimate for studentized statistics is more accurate than both the normal approximation and the two-term empirical Edgeworth expansion. In this article, it will be shown that the three-term empirical Edgeworth expansion for studentized statistics compares well with the bootstrap. It is also shown that the three-term Edgeworth expansion is superior to the bootstrap in some cases, using more efficient estimators than sample moments in the Edgeworth expansion, such as using maximum likelihood estimators in the one-parameter exponential family.
High-Resolution NMR of Quadrupolar Nuclei Using Mixed Multiple-Quantum Coherences

Abstract A multiple-quantum magic angle spinning (MQMAS) NMR experiment of quadrupolar nuclei is demonstrated, which uses two different multiple quantum coherences in t 1 to refocus the quadrupolar broadening. This experiment has the potential of achieving improved resolution over current techniques.
Structure of Relativistic Two-Particle Scattering Theories

The paper deals with two-particle scattering theories possessing both Lorentz invariance and a complete space-time description (i.e., a set of generators of the inhomogeneous Lorentz group describing interactions). We describe how to construct such theories starting, not from some assumed Hamiltonian, but from another operator, namely, the Cayley transform of the wave operator. This has the advantage that the scattering matrix is predetermined (i.e., known before solving any dynamical equations). The simplest possible model within the context of this approach is considered and solved exactly. This class of models contains the class considered by Jordan, Macfarlane, and Sudarshan.
Lymphotoxin production in AIDS

The etiological agent of the acquired immunodeficiency syndrome (AIDS), lymphadenopathy-associated virus/human T-lymphotropic virus III (LAV/HTLV-III), infects the OKT4(+) subset of T cells and causes their death. In this article Nancy Ruddle proposes that the trans acting protein of LAV/HTLV-III kills cells by inducing them to make a cellular cytotoxic protein, lymphotoxin, which in abnormally high quantities results in the cells' self-destruction. Lymphotoxin may even become serum detectable. It may induce immunosuppression and susceptibility to opportunistic infections by organisms such as Pneumocystis carinii. Defects in tumor immunity may result from depletion of OKT4(+) cells.
Syntheses and structures of and catalysis of hydrolysis by Zn(II) complexes of chelating pyridyl donor ligands

Zn(II) complexes of the ligands bis(2-pyridyl-2-ethyl)amine (bpea), bis(2-pyridylmethyl)amine (bpa), 2,2′-dipyridylamine (dipyam) and 2,2′-dipyridyl (dipy) [Zn 2 (bpea) 2 (μ-OH)](ClO 4 ) 3 ( 1 ), [Zn(bpa)(H 2 O) 2 ](ClO 4 ) 2 ( 2 ), [Zn(dipyam) 2 ](BF 4 ) 2 ( 3 ), [Zn(dipyam) 2 (DMF) 2 ] (ClO 4 ) 2 (4) and [Zn(dipy) 2 (H 2 O)] (BF 4 ) 2 (5) have been prepared and characterized. The structures of complexes 1 to 4 have been determined by X-ray crystallography. In complexes 1 and 3, Zn(II) coordinates in slightly distorted tetrahedral geometry and in complexes 2 and 4 in a distorted octahedral geometry. The number and the p K a values of the zinc-coordinated water molecules in solutions in water/DMF mixed solvent were determined by potentiometric titrations against aqueous NaOH solution. The p K a values are 8.35, 9.85, 8.00 and 9.01 for complexes 1, 2, 3 , and 5 respectively. The p K a value for the hydroxo-bridged dimeric complex 1 is about 0.8 pH units greater than the p K a value (7.55) for the analogous complex [Zn 2 (μ-OH)( m -xylbpea)](ClO 4 ) 3 of the ligand bis(bis(2-pyridyl-2-ethyl) amino) m -xylene ( m -xylbpea) in which the two chelating bis(2-pyridyl-2-ethyl)amine arms are tethered by a m -xylyl group. The lower p K a value in the latter complex is attributed to the entropic advantage gained as the two Zn(II) ions are held together by the dinucleating ligand. However, in the hydrolysis of bis ( p -nitrophenyl) phosphate (BNPP) catalyzed by Zn(II) complexes, the observed rate constant above pH 8 for complex 1 is significantly higher than that shown by the analogous complex formed by the dinucleating ligand. This difference for the latter complex may be due to the formation of a catalytically less active, possibly a double hydroxy-bridged moiety at lower pH values. The rate constants are observed to increase and pass through a maximum at or around the p K a values of all the zinc complexes reported here. This is consistent with the widely accepted mechanism in many hydrolytic reactions catalyzed by metal complexes in which the metal-coordinated hydroxide is the reactive nucleophile. Second-order rate constants of the order of 10 −3 –10 −2 M −1 s −1 were calculated for the hydrolysis of BNPP at the optimum pH values for the complexes studied here.
Measurement of EMI shielding of plastic composites using a dual chamber facility

Abstract The use of plastic materials as housings for electronic equipment depends on the ability to change the plastic composition from an insulator into an electrical conductor. Because there is a wide latitude in the level of conductivity that is achievable in such a composition, it is important to be able to relate the level of electromagnetic interference (EMI) shielding attained to the bulk resistivity of the conductive plastic composition. This report describes the use of a dual chamber method for measuring the EMI shielding effectiveness of polymer-based compositions. The system described is capable of measuring the shielding effectiveness of filled composites, coated samples, flat and molded structures and gaskets, and the effect of void spaces and joints. The dynamic range of this system is 80 dB , which is sufficient for most plastic compositions. Finally, a correlation between shielding effectiveness and bulk resistivity for filled compositions is presented, based on plane wave analysis. Theoretical predictions and experimental results are shown to be in excellent agreement.
Some properties of mycoplasma virus Br1

Morphologically mycoplasma virus Br1 is a typical contractile-tailed bacteriophage with a head 77 nm in diameter and a tail 104 nm long. Its type of nucleic acid was not determined. Br1 was closely associated with its host cell and assays reflected infectious centres. During growth of Br1 in mycoplasma cultures at multiplicities of infection (MOI) greater than 0.001, there was a lag period: this was up to 23 hours at an MOI of 35. The mean generation time of a mycoplasma culture infected at MOI up to 235 was 2 hours, compared with 1 hour for an uninfected culture. However in these infected cultures there were viable mycoplasmas all of which appeared to be fully susceptible to Br1 infection and did not seem to be carrying the virus. Br1 formed plaques onM. bovirhinis but failed to produce plaques on strains of 8Mycoplasma, 2Acholeplasma and 4 bacterial species.
Phase I Study of Anti-CD3 x Anti-Her2 Bispecific Antibody in Metastatic Castrate Resistant Prostate Cancer Patients.

Background. New nontoxic targeted approaches are needed for patients with castrate resistant prostate cancer (CRPC). Our preclinical studies show that activated T cells (ATC) armed with anti-CD3 x anti-Her2 bispecific antibody (Her2Bi) kill prostate cancer cells lines, induce a Th1 cytokine pattern upon engagement of tumor cells, prevent the development of prostate tumors, and retard tumor growth in immunodeficient mice. These studies provided strong rationale for our phase I dose-escalation pilot study to test ATC armed with Her2Bi (aATC) for safety in men with CRPC. Methods. Seven of 8 men with CRPC were evaluable after receiving two infusions per week for 4 weeks. The men received 2.5, 5 or 10 × 109 aATC per infusion with low dose interleukin-2 and granulocyte-macrophage colony stimulating factor. Results. There were no dose limiting toxicities, and there was 1 partial responder and 3 of 7 patients had significant decreases in their PSA levels and pain scores. Immune evaluations of peripheral blood mononuclear cells in 2 patients before and after immunotherapy showed increases in IFN-γ EliSpot responses and Th1 serum cytokines. Conclusions. These results provide a strong rationale for developing phase II trials to determine whether aATC are effective for treating CRPC.
Effects of model structural uncertainty on carbon cycle projections: biological nitrogen fixation as a case study

Uncertainties in terrestrial carbon (C) cycle projections increase uncertainty of potential climate feedbacks. Efforts to improve model performance often include increased representation of biogeochemical processes, such as coupled carbon–nitrogen (N) cycles. In doing so, models are becoming more complex, generating structural uncertainties in model form that reflect incomplete knowledge of how to represent underlying processes. Here, we explore structural uncertainties associated with biological nitrogen fixation (BNF) and quantify their effects on C cycle projections. We find that alternative plausible structures to represent BNF result in nearly equivalent terrestrial C fluxes and pools through the twentieth century, but the strength of the terrestrial C sink varies by nearly a third (50 Pg C) by the end of the twenty-first century under a business-as-usual climate change scenario representative concentration pathway 8.5. These results indicate that actual uncertainty in future C cycle projections may be larger than previously estimated, and this uncertainty will limit C cycle projections until model structures can be evaluated and refined.
Iron and the Liver

Iron is essential for life, but iron overload is toxic and potentially fatal. The liver is a major site of iron storage and is particularly susceptible to injury from iron overload, especially when (as in primary hemochromatosis) the iron accumulates in hepatocytes. Iron can be taken up by the liver in several forms and by several pathways including: (1) receptor-mediated endocytosis of diferric or monoferric transferrin or ferritin, (2) reduction and carrier-facilitated internalization of iron from transferrin without internalization of the protein moiety of transferrin, (3) electrogenic uptake of low molecular weight, non-protein bound forms of iron, and (4) uptake of heme from heme-albumin, heme-hemopexin, or hemoglobin-haptoglobin complexes. Normally, pathway 2 is probably the major one for uptake of iron by hepatocytes. Iron is stored in the liver in the cores of ferritin shells and as hemosiderin, an insoluble product derived from iron-rich ferritin. Iron in hepatocytes stimulates translation of ferritin mRNA and represses transcription of DNA for transferrin and transferrin receptors. The major pathologic effects of chronic hepatic iron overload are: (1) fibrosis and cirrhosis, (2) porphyria cutanea tarda, and (3) hepatocellular carcinoma. Although precise pathogenetic mechanisms remain unknown, iron probably produces these and other toxic effects by increasing oxidative stress and lysosomal lability. Vigorous efforts at diagnosis and treatment of iron overload are essential since the pathologic effects of iron are totally preventable by early vigorous iron removal and prevention of iron re-accumulation.
Product Channels of the N2 (A3Σ+u) + O2 interaction

Abstract Products of the N2(A) + O2 reaction were measured in a discharge-flow reactor. N2O accounts for only (2 ± 0.5)% of the reaction, contrary to recent reports, and O-atoms for 165 ± 10)% if N2(A) is quantitatively produced from Ar‡ with excess N2 This assumption is examined and specific N2(A) + O2 rate parameters are estimated.
Catalytic growth of carbon filaments

Abstract This article is a review of the information obtained by the author and his many co-workers from studies devoted to the formation of a fascinating material, filamentous carbon. Using the controlled atmosphere electron microcopy technique it has been possible to directly observe the manner by which various metal and alloys particles catalyze the growth of this form of carbon. Based on the qualitative and quantitative data obtained from these experiments, a mechanism was developed to account for the growth characteristics of filamentous carbon. From a consideration of the key steps involved in the process it has been possible to establish methods for controlling the growth of these structures. Continuous observation of many growth sequences has shown that both the addition of a second metal to the catalyst and also the strength of the metal-support interaction can play an important role in modifying the filament growth characteristics.
The recording of the fetal electrocardiogram

Abstract An improved method for recording the fetal electrocardiogram is described; it uses the 3-channel electroencephalograph and crystograph ink writers. Fetal waves were recorded successfully from the seventeenth week of pregnancy onward, and 82 per cent of the tracings taken during this period were positive. Certain advantages and uses of the method are indicated.
Anterior Cruciate Ligament Injury in National Collegiate Athletic Association Basketball and Soccer A 13-Year Review

BackgroundFemale collegiate athletes have been reported to have a higher rate of anterior cruciate ligament injury compared to male collegiate athletes. This finding has spawned a branch of researc...
Ion Stimulation, UDP Inhibition and Effects of Sulfhydryl Reagents on the Activity of Galactinol Synthase from Leaves of Cucumber, Cucumis sativus L.

Summary Galactinol synthase, UDP-D-galactose:inositol galactosyltransferase, was purified 105-fold from leaves of Cucumis sativus L. Mg ++ was unable to substitute for Mn ++ in stimulating activity. Low levels of Mn ++ were much more stimulatory at pH 7.0 than at pH 5.5. The optimum concentration of MnCl 2 at pH 7.0 was found to be 1.0 mM. Mn ++ concentration had no effect on Km for UDP-galactose or inositol but increased Vmax. UDP, a co-product with galactinol, was a competitive inhibitor with UDP-galactose and noncompetitive inhibitor for inositol. The sulfhydryl reagents DTNB and NEM completely inhibited activity. The substrate UDP-galactose, but not inositol or MnCl 2 , could protect against loss of activity. Protection experiments with UDP-galactose suggest that a thiol group(s) is necessary for activity of the enzyme.
Is Orthopedics More Competitive Today Than When My Attending Matched? An Analysis of National Resident Matching Program Data for Orthopedic PGY1 Applicants From 1984 to 2011

Objective This study evaluated supply and demand trends for orthopedic postgraduate year 1 (PGY1) positions from 1984 to 2011 for the purpose of estimating national intercandidate competition over time. Design National Resident Matching Program (NRMP) data for orthopedic surgery from 1984 to 2011 were collected. Proxy variables including (total number of orthopedic applicants/number of orthopedic PGY1 positions), (number of US senior applicants to orthopedics/number of orthopedic PGY1 positions), (number of US seniors matching into orthopedics/number of US senior orthopedic applicants), (total number of matched orthopedic applicants/total number of orthopedic applicants), and (total number of US applicants who fail to match into orthopedics/total number of US senior applicants into orthopedics) as well as average United States Medical Licensing Examination Step 1 scores were used to gauge the level of competition between candidates and were compared over time. Setting Academic medical center in the Midwestern United States. Participants Medical professors and medical students. Results The NRMP data suggested that the number of positions per applicant decreased or remained stable since 1984 and that the percentage of applicants who did not match was no higher now than in the past. This finding was primarily because of the relative decrease in the ratio of applicants to available PGY1 positions, which stems from the number of positions increasing more rapidly than the number of applicants. Conclusions The NRMP data from 1984 to 2011 supported our hypothesis that intercandidate competition intensity for orthopedic PGY1 positions has not increased over time. The misconception that orthopedics is becoming more competitive likely arises from the increased number of applications submitted per candidate and the resulting relative importance placed on objective criteria such as United States Medical Licensing Examination Step 1 scores when programs select interview cohorts.
Ion migration energies and color center absorption in hydroxyapatite

By modelling a hydroxyapatite crystal lattice as a finite cluster of atoms surrounded by an array of point ions, molecular orbital MS-Xα calculations point to differences in fluoride and hydroxyl migration energies. Despite the fluoride ion being more tightly bound to the lattice, it is in fact more mobile. Color center optical absorption is predicted to be in the infrared region of the spectrum for hydroxyapatite, whereas for fluorapatite the absorption peak of a vacancy is predicted to within 2% of the observed peak in the optical region. This result is discussed in terms of experimental studies of bonding between the calcified and organic phases of bone.
INFERENCE AND UNCERTAINTY PROPAGATION OF ATOMISTICALLY-INFORMED CONTINUUM CONSTITUTIVE LAWS, PART 1: BAYESIAN INFERENCE OF FIXED MODEL FORMS

Uncertainty quantification techniques have the potential to play an important role in constructing constitutive relationships applicable to nanoscale physics. At these small scales, deviations from laws appropriate at the macroscale arise due to insufficient scale separation between the atomic and continuum length scales, as well as fluctuations due to thermal processes. In this work, we consider the problem of inferring the coefficients of an assumed constitutive model form using atomistic information and propagation of the associated uncertainty. A nanoscale heat transfer problem is taken as the model, and we use a polynomial chaos expansion to represent the thermal conductivity with a linear temperature dependence. A Bayesian inference method is developed to extract the coefficients in this expansion from molecular dynamics (MD) samples at prescribed temperatures. Importantly, the atomistic data are incompatible with the continuum model because of the finite probability of heat flowing in the opposite direction of the temperature gradient; we present a method to account for this in the model. The fidelity and uncertainty in these techniques are then examined. Validation is provided by comparing a continuum Fourier model against a larger all MD simulation representing the true solution.
Recurrence and outcome in skull base meningiomas: do they differ from other intracranial meningiomas?

Intracranial meningiomas constitute 15 to 20% of primary brain tumors.1 Of these intracranial meningiomas, 20 to 30% are in the skull base.2 Meningiomas located on the convexity are usually accessible, circumscribed, and well demarcated from the neural and vascular structures. In contrast, skull base meningiomas are extensive, invasive, and intimately associated with cranial nerves, vessels, and brainstem. Taking into account these anatomical differences, the aim of surgery is complete resection in the case of convexity meningiomas and maximal possible resection with minimal neurological disability in the case of skull base meningiomas. Meningiomas have diverse presentations and the skull base harbors the most difficult to operate upon. Recurrence and outcome of these tumors may differ based on their location. Skull base meningiomas are often believed to have a higher rate of recurrence and worse prognosis compared with other intracranial meningiomas. However, the literature does not clearly and objectively support this opinion. The natural history of meningiomas has shown that tumor doubling times are much shorter in younger patients and annual growth rates tend to be higher.3 The biologic behavior of meningiomas varies considerably and the histology is not strongly predictive of behavior, especially in those categorized as WHO I meningiomas, since 21% of these tumors recur over 5 years.4 On the other hand, studies are available on tumor markers and labeling indices for proliferation/growth potential of meningiomas to predict recurrences and outcome.5,6
Visualization and Analysis of mRNA Molecules Using Fluorescence In Situ Hybridization in Saccharomyces cerevisiae

The Fluorescence in situ Hybridization (FISH) method allows one to detect nucleic acids in the native cellular environment. Here we provide a protocol for using FISH to quantify the number of mRNAs in single yeast cells. Cells can be grown in any condition of interest and then fixed and made permeable. Subsequently, multiple single-stranded deoxyoligonucleotides conjugated to fluorescent dyes are used to label and visualize mRNAs. Diffraction-limited fluorescence from single mRNA molecules is quantified using a spot-detection algorithm to identify and count the number of mRNAs per cell. While the more standard quantification methods of northern blots, RT-PCR and gene expression microarrays provide information on average mRNAs in the bulk population, FISH facilitates both the counting and localization of these mRNAs in single cells at single-molecule resolution.
An evaluation of the effectiveness of a computer simulation of anaesthetic uptake and distribution as a teaching tool.

Summary. Gas Man® is an interactive, microcomputer-based simulation and tutorial designed to teach the principles of anaesthetic uptake and distribution. Using two resident groups, one at a primary university-teaching hospital and the other at a medical school affiliated community hospital, the authors compared residents' knowledge of the subject prior to exposure to the tutorial and the average time spent using the program during a self-paced instruction period. Both groups not only significantly improved their knowledge of uptake and distribution 8 weeks after using this program, but wished to spend additional time with it, implying that it was a pleasant and satisfying way to learn. Computer simulation has the potential to be an important teaching tool in an anaesthesia residency training programme.
Effect of dissolved solids on reuse of produced water at high temperature in hydraulic fracturing jobs

Abstract Economic production from tight sand gas reservoirs usually involves multistage hydraulic fracturing. High costs of water acquisition and waste water disposal, and the lack of available water resources near operation sites, make the reuse of produced water an unavoidable option. However, recycling produced water in hydraulic fracturing jobs result in low quality fracturing fluids, which usually have high levels of hardness and salinity. This is especially true for flowback fluids, which contain high polymer loading. The viscosity and rheological properties of fracturing fluids significantly affect leak-off rate, proppant placement, length and width of fractures, fracture conductivity, and consequently, the success of the treatment. The objective of this study is to determine the acceptable dissolved solid contents for flowback fluids to prepare fracturing fluids. Analyses of 36 flowback fluid samples from the West Texas region were collected, and experimental studies were conducted on the analysis of the dissolved solids of produced water, which affect the application of flowback fluids and the capability of prepared fluids in proppant transport and handling. A high-pH borate crosslinked guar-based polymer was selected to determine the ranges of acceptable salt contents. Dynamic viscosity and rheological properties tests, static proppant settling, and small-amplitude oscillation rheology were the methods used to evaluate prepared samples at low, medium, and high temperatures up to 305 °F (152 °C). Some divalent cations such as calcium and magnesium have negative effects on the prepared polymers. Magnesium is the controlling ion, and approximately 30% of flowback fluids must be treated to meet the maximum acceptable concentration criterion. While monovalent cations such as sodium and potassium were tolerable at higher concentrations and the potassium contents in almost all flowback fluids met the determined acceptable value, more than 40% of samples required treatment for high sodium ion concentrations. Although the presence of other ions such as iron shows no significant variation in fracturing fluid properties, they can affect treatment in special cases. Adjusting the concentrations of the polymer, buffer, and crosslinker can minimize the adverse effects of temperature and salts. The fluids prepared with the determined ranges of dissolved solids showed reasonable thermal stability and proppant transport characteristics. This paper introduces the practical operating range for produced water composition and defines the ions that can adversely impact borate-crosslinked fracturing fluid characteristics at different temperatures.
Dissolved organic carbon of coal slurry transport water

Abstract The qualitative and quantitative occurrence and fate of dissolved organic carbon (DOC) leaching into coal slurry transport water was examined in laboratory-generated coal slurries and wastewaters from the Black Mesa coal slurry pipeline. Laboratory slurries were formulated for both western coals (Wyodak, Montana Rosebud and Black Mesa) and eastern coals (Illinois No. 6 and Pittsburgh No. 8). Sephadex G-25 elution profiles and ultrafiltration studies indicate that the majority of the organic compounds in western coal slurry wastewaters were lower (less than 1000) molecular weight species (62% for Wyodak and 74% for Montana Rosebud). Biochemical Oxygen Demand (BOD) for these particular wastewaters ranged from 50 to 150 mg l −1 as determined through the use of an electrolytic respirometer. Also, there was a concomitant 51–74% reduction in the DOC levels in the wastewaters. This removal was primarily due to the removal of the lower (
SAMPLE SIZE REQUIRED TO ESTIMATE A PARAMETER IN THE POWER FUNCTION DISTRIBUTION

The purpose of this paper is to establish a two step sampling procedure for estimating the parameter θ of the power function distribution to within givend units of its true value with a given probability 1—α;(0 1—α is true, whereyn is the largest observation in the second sample. The method used is deriving the results of this paper is similar to that given by Graybill and Connell (1964) and since the power function density reduces to the uniform density whenk=0, their results can be derived from the formulas given here. Also a table of comparisons between the expected second sample size in this paper and two other solutions is given.
Statistical significance of hierarchical multi‐body potentials based on Delaunay tessellation and their application in sequence‐structure alignment

Statistical potentials based on pairwise interactions between C alpha atoms are commonly used in protein threading/fold-recognition attempts. Inclusion of higher order interaction is a possible means of improving the specificity of these potentials. Delaunay tessellation of the C alpha-atom representation of protein structure has been suggested as a means of defining multi-body interactions. A large number of parameters are required to define all four-body interactions of 20 amino acid types (20(4) = 160,000). Assuming that residue order within a four-body contact is irrelevant reduces this to a manageable 8,855 parameters, using a nonredundant dataset of 608 protein structures. Three lines of evidence support the significance and utility of the four-body potential for sequence-structure matching. First, compared to the four-body model, all lower-order interaction models (three-body, two-body, one-body) are found statistically inadequate to explain the frequency distribution of residue contacts. Second, coherent patterns of interaction are seen in a graphic presentation of the four-body potential. Many patterns have plausible biophysical explanations and are consistent across sets of residues sharing certain properties (e.g., size, hydrophobicity, or charge). Third, the utility of the multi-body potential is tested on a test set of 12 same-length pairs of proteins of known structure for two protocols: Sequence-recognizes-structure, where a query sequence is threaded (without gap) through the native and a non-native structure; and structure-recognizes-sequence, where a query structure is threaded by its native and another non-native sequence. Using cross-validated training, protein sequences correctly recognized their native structure in all 24 cases. Conversely, structures recognized the native sequence in 23 of 24 cases. Further, the score differences between correct and decoy structures increased significantly using the three- or four-body potential compared to potentials of lower order.
Abstract 5358: BRCA1 is a negative modulator of the PRC2 complex.

The Polycomb repressive complex 2 (PRC2) is important for maintenance of stem cell pluripotency and suppression of cell differentiation by promoting histone H3 lysine 27 trimethylation (H3K27me3) and transcriptional repression of differentiation regulatory genes. Here we show that the tumor suppressor protein BRCA1 interacts with EZH2 and other components of PRC2 in mouse embryonic stem (ES) and human breast cancer cells. The BRCA1-binding region in EZH2 overlaps with the non-coding RNA (ncRNA)-binding domain, and BRCA1 expression inhibits the binding of EZH2 to the HOTAIR ncRNA. Decreased expression of BRCA1 causes EZH2 re-targeting genome wide and elevates H3K27me3 levels at PRC2 target loci in both mouse ES and human breast cancer cells. BRCA1 deficiency blocks ES cell differentiation and enhances breast cancer migration and invasion in an EZH2-dependent manner. These results reveal that BRCA1 is a key negative modulator of PRC2 and that loss of BRCA1 inhibits ES cell differentiation and enhances cancer aggressive phenotypes via augmented PRC2 function. Citation Format: Xianzhou Zeng, Shuai Chen, Lan Wang, Haojie Huang. BRCA1 is a negative modulator of the PRC2 complex. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 5358. doi:10.1158/1538-7445.AM2013-5358
Electron binding and chemical inertness of specific Nbx clusters

Photoionization threshold measurements on niobium clusters Nbx x=4–29, reveal an unprecedentedly strong dependence on x, the number of atoms in the cluster. Major maxima in threshold energies occurring at x=8, 10, and 16 correspond to those clusters recently shown to be unreactive toward molecular deuterium.
Modeling & Simulating of Hami-Zhengzhou UHVDC Transmission Project and Security & Stability Analysis of Send-Side Power System

Hami-Zhengzhou ±800kV DC project is the first ultra high-voltage project for Xinjiang power transmission, it is also the first DC transmission project binding thermal and wind power, with bipolar low-end operation in 2013 and bipolar operation in the middle of 2014. The rated power is 8,000MW. This article focused on Hami-Zhengzhou HVDC transmission system, established the electromechanical model, which improved commutation failure treatment in the traditional DC control system and made the simulation results more close to the real operation condition. Based on this model, security and stability analysis of power grid was carried out and the corresponding control strategies/schemes were brought up.
Divalent lanthanide complexes free of coordinating anions: facile synthesis of fully solvated dicationic [LnLx]2+ compounds

Abstract Fully-solvated, divalent lanthanide dication complexes free of coordinating anions, [LnLx]2+, in which L=MeCN, THF, have been synthesized by protonation of amide, indenyl, and pentamethylcyclopentadienyl precursors. The Sm(II) dication [Sm(THF)7]2+ was initially isolated as [Sm(THF)7][BPh4]2, (1), by protonolysis of the indenyl complex (C9H7)2Sm(THF)3 with [Et3NH][BPh4]. Compound 1 can also be obtained from (C5Me5)Sm[N(SiMe3)2](THF)2 and [Et3NH][BPh4]. The Yb analog, [Yb(THF)6][BPh4]2, (2), was obtained from the reaction of the bimetallic [(C5Me5)Yb(THF)]2(C8H8) with AgBPh4 and the reaction of (C5Me5)Yb[N(SiMe3)2](THF)2 with [Et3NH][BPh4], but [YbLx]2+ is best obtained from the reaction of Yb[N(SiMe3)2]2(THF)2 with [Et3NH][BPh4]. Reaction of Yb[N(SiMe3)2]2(THF)2 with [Et3NH][BPh4] in THF followed by recrystallization from acetonitrile affords [Yb(MeCN)8][BPh4]2, (3). The seven THF molecules in 1 form a pentagonal bipyramidal ligand environment around Sm2+. Complex 2 has an octahedral Yb2+ coordination environment and 3 has a distorted square antiprismatic arrangement of MeCN ligands around Yb2+.