cssi/SciSciGPT-SciSciNet huggingface dataset:
On the spectrum of ( 1 + 1 ) -dimensional QCD with S U ( N c ) currents

Extending previous work, we calculate the fermionic spectrum of two-dimensional QCD $({\mathrm{QCD}}_{2})$ in the formulation with ${SU(N}_{c})$ currents. Together with the results in the bosonic sector this allows us to address the as yet unresolved task of finding the single-particle states of this theory as a function of the ratio of the numbers of flavors and colors, $\ensuremath{\lambda}{=N}_{f}{/N}_{c},$ anew. We construct the Hamiltonian matrix in the DLCQ formulation as an algebraic function of the harmonic resolution K and the continuous parameter \ensuremath{\lambda} in the Veneziano limit. We find that the fermion momentum is a function of \ensuremath{\lambda} in the discrete approach. A universality, existing only in two dimensions, dictates that the well-known 't Hooft and large ${N}_{f}$ spectra be reproduced in the limits $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\lambda}}0$ and \ensuremath{\infty}, which we confirm. We identify their single-particle content which is surprisingly the same as in the bosonic sectors. All multiparticle states are classified in terms of their constituents. These findings allow for an identification of the lowest single particles of the adjoint theory. While we do not succeed in interpreting this spectrum completely, evidence is presented for the conjecture that adjoint ${\mathrm{QCD}}_{2}$ has a bosonic and an independent fermionic Regge trajectory of single-particle states.
Cyclical Changes in Susceptibility of A Myeloma Tumor (LPC-1) to Immune Destruction: I. Changes in Reactivity with Cytotoxic T Lymphocytes and anti-H-2D Sera

One of six transplantable ascites tumors of BALB/c mice was found to become periodically resistant to cytotoxic T lymphocytes (CTL). About 12 days after LPC-1, a myeloma tumor, was transplanted it became resistant to lysis by allogenic CTL (anti-H-2d) and by CTL directed to trinitrophenyl groups or minor histocompatibility antigens. Susceptibility to lysis by all of these CTL was regained within 2 to 4 days after transfer of resistant cells to a fresh BALB/c host. These changes were recurrent: in each transplantation cycle the early LPC-1 cells were susceptible and the late cells were resistant to CTL. Analyses with antisera (B10 anti-B10.D2) showed that the serologically recognized products of the H-2d haplotype were reduced about 10-fold on the LPC-1 cells that were resistant to CTL.
Utilisation of erythrocyte 6-thioguanine metabolite levels to optimise azathioprine therapy in patients with inflammatory bowel disease

BACKGROUND AND AIM The immunosuppressive properties of 6-mercaptopurine and its parent compound azathioprine are mediated by their intracellular metabolism into active 6-thioguanine (6-TG) metabolites. Measurement of erythrocyte 6-TG metabolite levels has been proposed as a useful clinical tool for assessing treatment efficacy in patients with inflammatory bowel disease (IBD). AIM The purpose of the study was to establish a therapeutic index of treatment efficacy based on measurement of erythrocyte 6-TG metabolite levels, and apply it clinically to guide therapy. METHODS Heparinised blood was obtained from 82 adult patients with IBD on long term (more than three months) antimetabolite therapy (63 Crohn9s disease; 19 ulcerative colitis). Erythrocyte 6-TG metabolite levels were measured using reverse phase high performance chromatography, and correlated with treatment efficacy. In 22 patients with refractory Crohn9s disease despite long term azathioprine therapy, their dosage was increased by 25 mg/day at eight week intervals as needed. Serial erythrocyte 6-TG metabolite levels were measured at each clinic visit and correlated with treatment efficacy. RESULTS Clinical remission, as defined by a low disease index score in patients weaned off or on a low alternate day dose ( 8 red blood cells in patients with colonic and fistulising Crohn9s disease (p 8 red blood cells (p 3 /μl with adjustment in azathioprine dosage. No patient incurred azathioprine induced leucopenia. CONCLUSION Measurement of erythrocyte 6-TG metabolite levels is helpful in determining the adequacy of azathioprine dosage and can be used to optimise the dose of antimetabolite therapy to achieve an improved clinical response without inducing leucopenia. Patients who are clinically refractory to azathioprine therapy despite achieving high erythrocyte 6-TG levels (>250) should be considered for adjunct or alternative forms of immunosuppressive therapy or surgery.
Influence of understory removal, thinning and P fertilization on N2fixation in a mature mesquite (Prosopis glandulosavar.glandulosa) stand☆

Abstract The natural abundance 15 N/ 14 N method was used to estimate the influence of silvicultural and P fertilization treatments on N accretion, N 2 fixation and N partitioning among tissues in a mature mesquite Prosopis glandulosa var. glandulosa stand in Texas. The silvicultural treatments consisted of understory removal, herbicide treatment of brushy resprouts, thinning trees to single stems and 100 kg ha −1 P fertilization. The trees had a mean basal diameter of 17·8 cm with 8 to 35 cm range. The stand was slow growing with the increase in dry matter ranging from 0·465 Mg ha −1 year −1 to 0·701 Mg ha −1 year −1 for the 8 years after the treatments were applied. N accretion after 8 years ranged from 3·1 kg ha −1 year −1 to 4·4 kg ha −1 year −1 . Due to the range in δ 15 N of the leaves, twigs, branches and trunk, we used the weighted (by biomass) average δ 15 N per tree in calculations of the percent N derived from N 2 fixation (%Ndfa). There was considerable variability in δ 15 N of the reference plants, i.e. from 3·3 to 5·9. In contrast there was low variability in the background δ 15 N of nearby soils (7·0±1·0). As the total above-ground biomass δ 15 N of a grass grown outside the influence of mesquite (7·8±0·58) had the same δ 15 N as the soil (7·5±1·0), we used the grass outside the influence of mesquite and the weighted tree mean δ 15 N to calculate % of N derived from N 2 fixation. The decrease in intraspecific competition by thinning multistemed trees to single stemmed trees was the only treatment that significantly ( p = 0·0001) increased growth. Interspecific competition, i.e. understory removal, did not increase growth. There were no significant differences in total N production or N fixation among treatment means. The most striking result was the highly positive correlation between tree δ 15 N and total N per tree and biomass per tree ( R 2 = 0·90, F = 164·4, df. = 18, mean square error (MSE) = 0·155, p = 0·0001). This implies that the younger trees colonizing infertile soils relied more heavily on N 2 fixation than larger trees which accumulated 1200 kg ha −1 more N under their canopies. The percentage N derived from N 2 fixation ranged from 63 to 73% in the various treatments. Despite the high percentage of N derived from N 2 fixation, the N 2 fixation of the stand was very low, i.e. 1·98 to 2·80 kg N ha −1 year −1 , due to the low growth of the stand. We believe that comparisons of the whole tree weighted δ 15 N to background soil δ 15 N provides a more reasonable approach to estimate % N 2 fixation than comparisons of leaves of fixers and reference plants.
The evolution of vortex beams in atmospheric turbulence

The evolution of the scintillation and topological charge of coherent vortex beams in turbulence is analyzed. Although such beams typically have inferior scintillation properties when compared with a comparable Gaussian beam, the topological charge of the vortex beam shows significant stability. The possibility of using such beams in optical communications is discussed.
Bone Graft Substitute: Allograft and Xenograft

Rapid bone graft incorporation for structural rigidity is essential. Early range of motion, exercise, and weight-bearing are keys to rehabilitation. Structural and nonstructural bone grafts add length, height, and volume to alter alignment, function, and appearance. Bone graft types include: corticocancellous autograft, allograft, xenograft, and synthetic graft. Autogenic grafts are harvested from the patient, less likely to be rejected, and more likely to be incorporated; however, harvesting adds a procedure and donor site complication is common. Allografts, xenografts, and synthetic grafts eliminate secondary procedures and donor site complications; however, rejection and slower incorporation can occur.
The response of the continental crust-Mantle boundary observed on broadband teleseismic receiver functions

Broadband receiver functions derived from teleseismic P-waveforms recorded on Regional Seismic Test Network (RSTN) stations in Eastern North America contain detailed information about the crust-mantle boundary. This paper examines receiver functions from three stations (RSCP, RSNY, and RSON) to illustrate the variability in response of the continental "Moho" and to demonstrate the utility of broadband data in studying these variations. Of particular interest is the clear evidence for frequency-dependence of the amplitudes of converted phases arriving from the crust-mantle boundary. The shear velocity structures for these stations obtained by inverting the radial component of the receiver functions in the time domain indicate that this frequency-dependence is a measure of the "sharpness" of the crust-mantle boundary region.
Robust nonlinear feedback–feedforward control of a coupled kinetic Monte Carlo–finite difference simulation

Abstract Robust nonlinear feedforward–feedback controllers are designed for a multiscale system that dynamically couples kinetic Monte Carlo (KMC) and finite difference (FD) simulation codes. The coupled codes simulate the copper electrodeposition process for manufacturing on-chip copper interconnects in electronic devices. The control objective is to regulate the current density subject to the condition that the steady-state fluctuation of the overpotential remains bounded within ±0.01 V. The controller designs incorporate a low-order stochastic model that captures the input–output behavior of the coupled KMC–FD code. The controllers achieve the objectives and the closed-loop responses implemented on the low-order model and the coupled KMC–FD code match well within stochastic variations. The nonlinear feedforward control reduces the rise time of the controller response while the feedback control ensures robustness in the presence of model uncertainty.
Elemental concentrations in plant tissues as influenced by low pH soils

Soils influenced by acid mine drainage (pH<5.0) are characterized by low concentrations of essential nutrients and increased solubility of heavy metals. The conditions typically reduce plant establishment and growth. However, river birch (Betula nigra L.) is commonly found along low pH streams in southeastern Ohio. The objective of this study was to determine the concentration of Al, Mn, Ca and Mg inB. nigra tissues.
Comparison of inlet geometry in microfluidic cell affinity chromatography.

Cell separation based on microfluidic affinity chromatography is a widely used methodology in cell analysis research when rapid separations with high purity are needed. Several successful examples have been reported with high separation efficiency and purity; however, cell capture at the inlet area and inlet design have not been extensively described or studied. The most common inlets—used to connect the microfluidic chip to pumps, tubing, etc.—are vertical (top-loading) inlets and parallel (in-line) inlets. In this work, we investigated the cell capture behavior near the affinity chip inlet area and compared the different performances of vertical inlet devices and parallel inlet devices. Vertical inlet devices showed significant cell capture capability near the inlet area, which led to the formation of cell blockages as the separation progressed. Cell density near the inlet area was much higher than that in the remaining channel, whereas for parallel inlet chips cell density at the inlet area was similar...
WNT7B mediates autocrine Wnt/β-catenin signaling and anchorage-independent growth in pancreatic adenocarcinoma

Developmental and cancer models show Wnt/β-catenin-dependent signaling mediates diverse phenotypic outcomes in the pancreas that are dictated by context, duration and strength of activation. While generally assumed to be pro-tumorigenic, it is unclear to what extent dysregulation of Wnt/β-catenin signaling impacts tumor progression in pancreatic adenocarcinoma (PDAC). In the present study, Wnt/β-catenin activity was characterized across a spectrum of PDAC cell lines and primary tumors. Reporter and gene expression-based assays revealed wide heterogeneity in Wnt/β-catenin transcriptional activity across PDAC cell lines and patient tumors, as well as variable responsiveness to exogenous Wnt ligand stimulation. An experimentally generated, pancreas-specific gene expression signature of Wnt/β-catenin transcriptional activation was used to stratify pathway activation across a cohort of resected, early-stage PDAC tumors (N=41). In this cohort, higher Wnt/β-catenin activation was found to significantly correlate with lymphvascular invasion and worse disease-specific survival (median survival time 20.3 versus 43.9 months, log-rank P=0.03). Supporting the importance of Wnt ligand in mediating autocrine Wnt signaling, Wnt/β-catenin activity was significantly inhibited in PDAC cell lines by WLS gene silencing and the small-molecule inhibitor IWP-2, both of which functionally block Wnt ligand processing and secretion. Transcriptional profiling revealed elevated expression of WNT7B occurred in PDAC cell lines with high levels of cell autonomous Wnt/β-catenin activity. Gene-knockdown studies in AsPC-1 and HPAF-2 cell lines confirmed WNT7B-mediated cell autonomous Wnt/β-catenin activation, as well as an anchorage-independent growth phenotype. Our findings indicate WNT7B can serve as a primary determinant of differential Wnt/β-catenin activation in PDAC. Disrupting the interaction between Wnt ligands and their receptors may be a particularly suitable approach for therapeutic modulation of Wnt/β-catenin signaling in PDAC and other cancer contexts where Wnt activation is mediated by ligand expression rather than mutations in canonical pathway members.
DEVELOPMENT AND EVALUATION OF DRAINAGE-N MODEL FOR PREDICTING NO3-N CONCENTRATIONS AND LOSSES IN SUBSURFACE DRAINAGE WATER

The DRAINAGE model was used to develop the DRAINAGE-N model with capability to simulate NO3-N concentrations in subsurface drain flows by incorporating the nitrogen component from the GLEAMS model. Field data on NO3-N concentrations in subsurface drain water were used to calibrate and validate the DRAINAGE-N model for the growing seasons of 1984, 1986, 1987, 1990, and 1991. Simulated NO3-N concentrations and losses with subsurface drain flows were compared with the measured values. Predicted daily NO3-N concentrations in the subsurface drain water by the DRAINAGE-N model were close to the observed NO3-N concentrations values (difference over all years –5.7%). Predicted seasonal NO3-N losses with subsurface drain flows were also in close agreement with the observed data (difference over all years –1.1%). Statistical measures RMSE, EF, and CD were calculated for 5 years of combined seasonal values of NO3-N concentrations and values for these parameters were 0.12, 0.34, and 1.5, respectively. Predicted soil profile NO3-N concentrations were within one standard deviation of the means of observed concentrations, with a few exceptions. Overall results of this study indicate that the DRAINAGE-N model has good potential for simulating long-term NO3-N concentrations and losses with the subsurface drain flows.
Eosinophilia, Respiratory Symptoms and Pulmonary Infiltrates in Rubber Workers

This report describes a spectrum of respiratory illnesses associated with eosinophilia which occurred in a group of workers exposed to fumes from a synthetic rubber-based curing operation. Respiratory syndromes induced by this exposure included an acute sensitizing illness with dyspnea and wheezing in some workers and pulmonary infiltrates with eosinophilia in others. Another worker developed chronic obstruction of the airways with recurrent bronchitic illnesses. Mild to marked peripheral eosinophilia, up to 3,000/cu mm, was usually present in the symptomatic workers and in 11 of 30 asymptomatic workers. These cases illustrate the diversity of respiratory illnesses which may result from a common workplace exposure and reinforce the importance of considering occupational exposures in the differential diagnosis of peripheral eosinophilia.
Concepts for Achieving Multi-Stability in Compliant Rolling-Contact Elements

This paper describes the design of a novel multi-stable compliant mechanism capable of large angle deflections. The multi-stable COmpliant Rolling-contact Element (CORE), reduces friction, allows for large angular displacements, and requires no external force to remain in its multiple equilibrium positions. This paper develops and discusses seven methods to create multi-stable mechanisms from the CORE. These seven methods have different characteristics and advantages.Copyright © 2007 by ASME
Cloning of a pair of genes encoding isoschizomeric restriction endonucleases from bacillus species: the BspEI and BspMII restriction and modification systems

The respective genes (R-M) encoding restriction and modification systems from two Bacillus species which recognise the same nucleotide sequence, 5'-TCCGGA, have been cloned and expressed in Escherichia coli. The BspEI R-M genes were cloned on a 3.6-kb HindIII fragment, whereas the BspMII R-M genes were cloned on three contiguous HindIII fragments totalling 9.8 kb. Upon thermal induction, E. coli carrying the bspEIR clones under the control of the phage lambda PL promoter, express high levels of R.BspEI (10(6) units/g wet cell paste). The bspMIIR gene, on the other hand, is only poorly expressed (about 4 x 10(3) units/g wet cell paste) following induction. Although the enzymes of both R-M systems recognize the same sequence and the restriction endonucleases (ENases) cleave DNA at the same position, the modification specified by the methyltransferases (MTases) differ. The internal cytosine is the site of M.BspMII modification (TCmeCGGA), whereas the external cytosine is modified by M.BspEI (TmeCCGGA). The two R-M systems probably evolved independently.
Forces required to jettison a simulated S92 passenger exit: Optimal helicopter underwater egress training techniques

Abstract This paper outlines the first known examination of the forces required to jettison a simulated exit used during helicopter underwater egress training (HUET). To capture the forces placed on the simulated cabin exit, a purpose build force plate was designed to replace an existing simulator exit used during HUET. A 25-point map was created to identify specific jettison forces required across the entire exit surface. Ten participants completed a total of 120 underwater egress sequences in–air and in-water from a normal flight and fully compressed crash attenuating seat position. The results indicate that the force required to jettison the simulated exit is significantly different in relationship to location on the exit surface. From the results, it can be concluded that helicopter underwater egress training protocols should ensure that offshore candidates are informed of the different force requirements as well as have the opportunity to practice jettisoning a high physical fidelity exit from a fully compressed crash attenuating seat. Relevance to industry: This is the first paper to investigate the forces required to jettison a simulated S92 exit used in an underwater egress simulator. The combined exit force map and maximal voluntary jettison force data provide a greater understanding of influencing factors associated with training offshore personnel to egress a ditched helicopter.
Stimulation by N6,O2'-dibutyryl adenosine 3',5'-cyclic-phosphate of amino acid transport, protein synthesis, and chondroitin sulfate synthesis in embryonic bone in vitro contrasted with the effects of thyroid hormones.

Abstract Measurement were made of the effects of N 6 ,O 2′ -dibutyryl adenosine 3′,5′-cyclic-phosphate on uptake and incorporation of amino acids and inorganic sulfate by intact pelvic bones of 10-day chick embryos. The N 6 ,O 2′ -dibutyryl adenosine 3′,5′-cyclic-phosphate causes of 20–50% stimulation of transport of metabolizable and non-metabolizable neutral amino acids, of amino acid incorporation, and of inorganic sulfate incorporation. The effect of theophylline on amino acid transport was comparable to that of N 6 ,O 2′ -dibutyryl adenosine 3′,5′-cyclic-phosphate but theophylline did not stimulate incorporation of amino acids or of sulfate. Cyclic 3′,5′-AMP (with or wihout theophylline), 5′-AMP, and potassium butyrate were without effect. Comparisons of the effects of N 6 ,O 2′ -dibutyryl adenosine 3′,5′-cyclic-phosphate and of thyroid hormones on amino acid transport do not support the possibility that the stimulation by thyroid hormones is mediated by cyclic 3′-5′-AMP.
A new complementing cell line for replication-incompetent E1–deleted adenovirus propagation

Recombinant adenoviruses (Ad) are being explored as promising delivery systems for gene therapy and vaccination. However, there is a concern about the possibility of generating replication-competent adenoviruses (RCA) using the human embryonic kidney 293 cell line. We have constructed a new cell line named the UR cell line which can be used to produce Ad vectors free of RCA. This cell line is based on the human embryonic lung HEL 299 cell. We first constructed a shuttle plasmid which encodes the E1A/E1B sequence that is necessary for adenovirus replication. The shuttle plasmid was then transfected into HEL 299 cells. The presence of the E1A/E1B sequence and protein expression in the stably transformed UR cells was confirmed. Viruses produced in UR cells were still RCA-free after ten test passages, while adenovirus produced in 293 cells had generated RCA during the fourth passage. We conclude that the UR cell line is sufficiently stable, can effectively produce a virus yield comparable with 293 cells, and does not generate RCA formation during Ad propagation.
Concordance in histological and biological parameters between first and second primary breast cancers

BACKGROUND: Women with breast cancer are more likely to have a second breast cancer than women in the general population are to have a primary cancer. However, the biological relationship between primary and second breast cancers is not clear. METHODS: A total of 30,617 patients diagnosed with bilateral breast cancers between 1990 and 2007 were identified through 17 cancer registries of the Surveillance, Epidemiology, and End Results program. Logistic regression with odds ratios (ORs) and 95% confidence intervals (CIs) was used to model strength of association in hormone receptor status, grade, and histology between 2 cancers. RESULTS: There was a strong association in estrogen receptor status between 2 bilateral tumors (OR, 7.64; 95% CI, 7.00-8.35). The strength of association in estrogen receptor status depended on the time interval between the first and second tumors and age at diagnosis. The OR was 25.9 for synchronous tumors (within 1 month) and 3.69 for metachronous tumors separated by ≥10 years. The strength of association was stronger in patients whose first cancer was diagnosed before age 50 (OR, 11.7) versus after age 50 (OR, 5.71). A similar pattern was observed for progesterone receptor, grade, and histological type, but with relatively weaker association. CONCLUSIONS: The strong concordance in hormone receptor status of primary and second breast cancers suggests that 2 breast cancers arise in a common milieu and that tumor subtypes are predetermined in the early stage of breast carcinogenesis. Cancer 2011. © 2010 American Cancer Society.
Measurement of nitric oxide and peroxynitrite generation in the postischemic heart: Evidence for peroxynitrite-mediated reperfusion injury

Altered nitric oxide (NO.) production is a critical factor in tissue reperfusion injury; however, controversy remains regarding these alterations and how they cause injury. Since superoxide (O-2) generation is triggered during the early period of reperfusion the cytotoxic oxidant peroxynitrite (ONOO-) could be formed, but it is not known if this occurs. Therefore electron paramagnetic resonance and chemiluminescence studies were performed of the magnitude and time course of NO., O-2, and ONOO- formation in the postischemic heart. Isolated rat hearts were subjected either to normal perfusion or to reperfusion after 30 min of ischemia in the presence of the NO. trap Fe2+-N-methyl-D-glucamine dithiocarbamate with electron paramagnetic resonance measurements performed on the effluent. Although only trace signals were present prior to ischemia, prominent NO. adduct signals were seen during the first 2 min of reflow which were abolished by nitric oxide synthase (NOS) inhibition. Similar studies with the O-2 trap 5, 5-dimethyl-1-pyrroline N-oxide demonstrated a burst of O-2 generation over the first 2 min of reflow. Chemiluminescence measurements using 5-amino-2,3-dihydro-1,4-phthalazinedione (luminol) demonstrated a similar marked increase in ONOO- which was blocked by NOS inhibitors or superoxide dismutase. NOS inhibition or superoxide dismutase greatly enhanced the recovery of contractile function in postischemic hearts. Immunohistology demonstrated that the ONOO--mediated nitration product nitrotyrosine was formed in postischemic hearts but not in normally perfused controls. Thus, NO. formation is increased during the early period of reflow and reacts with O-2 to form ONOO-, which results in amino acid nitration and cellular injury.
A New Ultra-violet Band Spectrum of Hydrogen Chloride

HITHERTO no band spectra have been found which involve electronic excitation in neutral or ionised hydrogen chloride. We have recently photographed an extended band system in the region λ2830–λ3966 from a low pressure discharge in pure hydrogen chloride gas with platinum electrodes. The bands are degraded toward long wave-lengths, and have the characteristic widely spaced structure always observed in hydride spectra. A discharge in hydrogen gives the same band system if a small amount of silver chloride or cuprous chloride is fused on the electrodes, but not if silver bromide is used. Thus there is strong evidence that this spectrum is due to the hydrogen chloride molecule. Moreover, there are reasons, both experimental and theoretical, for believing that the emitter is singly charged, probably the HCl+ ion. For example, the bands are obtained only from the negative glow, whereas in general the spectra of ionised molecules, such as N+2, are relatively stronger.
Psychology in Advertising What Research Says about Subliminal Stimulation

Abstract “The terms self-indulgent, pleasure-minded, materialistic, passive and conforming are being used more and more in describing the American public and especially the American youth. The question might well be asked, ‘What effect has the nature of advertising had upon developing these characteristics?’”
Cross-Cultural Study of Relationships among Four Dimensions of Time Perspective

The purpose of the present investigation was (a) to describe the internal structure of the concept of time perspective in terms of rationally developed dimensions derived from performance on one task and (b) to determine whether or not this internal structure was in any way different for three ethnic groups (Spanish-American, American Indian, and Anglo-American), two age groups (10 and 16 yr.), and two thematic content areas (religious and social). Measures of temporal extension, location, and kinesis were derived from a story-telling task. Data were analyzed by a multi-dimensional χ3 analysis. The three measures were differentially sensitive to variables introduced. For example, ethnic differences were most clearly shown by the kinetic measure and content differences by extension. A rationale for a partial interpretation of the findings within a cultural context was suggested.
Language Choice for CS1 and CS2: Experiences from Two Universities

Computer Science departments are forced to address the choice of programming language in beginning computer science courses repeatedly as programming languages continue to be developed and improved. (Note the recent advent of Java.) This choice will be revisited in a cyclical fashion on an ongoing basis. In this article, we present a set of criterion that can be used to address this issue. We do not support or defend any particular programming language, but present a method that can be used to make this decision. This method in the form of a set of criterion is applied to two universities which have made different choices each of which is valid for its context.
Synthesis and sol-gel polymerization of [Si8O12](OCH3)8

Sol-gel polymerization of [Si8O12](OCH3)8 in an inert solvent under neutral conditions has been shown to yield very high-surface area silica xerogels [P. C. Cagleet al., Mater. Res. Soc. Symp. Proc.180, 29 (1990)]. Two recent results relevant to this process are described here. First, a practical synthetic route to [Si8O12](OCH3)8 is described that allows multigram quantities to be conveniently prepared. Second, TEM studies are reported that confirm retention of the [Si8O12] cubic core structure in high-surface area, [Si8O12](OCH3)8− derived xerogels.
Lactate Transport in Soil by DC Fields

Electrokinetic injection of lactate, a negatively charged biodegradable organic, in homogeneous soils is evaluated. Net lactate migration rate on the order of 5 cm2 ∕V day is measured in sand from cathode towards the anode. The ionic injection in sand was dependent on current density; however, the increase in electric current did not result in an equivalent increase in lactate transport due to development of an appreciable electroosmotic (EO) flow from the anode to the cathode. While high EO flow ( ke on the order 10−6 to 10−5 cm2 ∕V s ) occurred in clay samples, ion migration from cathode to anode is the dominant transport process under relatively high current density ( 5.3 A∕ m2 in this study) and can be used as an effective transport mechanism for negatively charged additives. An effective lactate reactive transport rate of more than 3 cm∕d (under 1 V∕cm ) can be achieved in clays, which is at least two orders of magnitude greater than hydraulic injection under unit hydraulic gradient. Even though lact...
Photoaffinity analogues of farnesyl pyrophosphate transferable by protein farnesyl transferase.

Farnesylation is a posttranslational lipid modification in which a 15-carbon farnesyl isoprenoid is linked via a thioether bond to specific cysteine residues of proteins in a reaction catalyzed by protein farnesyltransferase (FTase). We synthesized analogues (3−6) of farnesyl pyrophosphate (FPP) to probe the range of modifications possible to the FPP skeleton which allow for efficient transfer by FTase. Photoaffinity analogues of FPP (5, 6) were prepared by substituting perfluorophenyl azide functional groups for the ω-terminal isoprene of FPP. Substituted anilines replace the ω-terminal isoprene in analogues 3 and 4. Compounds 3−5 were prepared by reductive amination of the appropriate anilines with 8-oxo-geranyl acetate, followed by ester hydrolysis, chlorination, and pyrophosphorylation. Additional substitution of three methylenes for the β-isoprene of FPP gave photoprobe 6 in nine steps. Preparation of the analogues required TiCl4-mediated imine formation prior to NaBH(OAc)3 reduction for anilines wit...
Trends and Attitudes Regarding Head and Neck Oncologic Surgery: A Survey of United States Oral and Maxillofacial Surgery Programs

Purpose The purposes of this study were to: 1) estimate the prevalence and trends of American oral and maxillofacial surgery (OMS) programs in recruiting head and neck oncologic surgery (HNOS) -trained faculty, performing HNOS oncologic procedures and microvascular reconstruction, and presenting HNOS research at academic meetings; 2) estimate whether HNOS and microvascular reconstruction involvement varies among programs with or without a program director or chair trained in HNOS; 3) estimate whether HNOS involvement varies among those OMS programs that regularly attend and do not attend tumor board; 4) estimate whether HNOS involvement varies among those programs that have and have not presented HNOS research at an academic meeting; 5) estimate whether HNOS involvement varies among doctor of medicine-integrated and 4-year OMS programs. Materials and Methods Investigators developed and distributed a survey to all US OMS program directors and/or chair composed of questions regarding faculty prevalence and recruitment, frequency and trends in cases, and the priority of applicants for residency with regard to HNOS. There were 18 close-ended questions, and one open-ended question. Responses were recorded in categorical, Likert, ordinal, and numerical format. Bivariate associations were calculated using Fisher exact test and logistic regression. Results Sixty-three of 101 surveys were returned (62.3%). Ten program directors or chair completed a fellowship in HNOS (15.9%). Programs with an HNOS-trained program director or chair were more likely to have another HNOS-trained faculty member (P = .01), performed more malignant tumor resections (P Conclusions This study's data and comments suggest that programs involved in HNOS have a strong involvement in expanded scope OMS and related academic activities.
Crystal and Molecular Structure of Titanium (IV) Ethoxide

BOTH speculation and controversy on the stereochemistry of the trimeric titanium (IV) alkoxides1–6 have followed the discovery6 of their trimeric nature in solution. Opinions have differed on which structure is stereochemically reasonable and on which structure will account in a natural way for the hydrolysis products of titanium (IV) alkoxides, the so-called titanium oxide-alkoxides of composition Ti3(x+1)O4x(OR)4(x+3). These titanium oxide-alkoxides have been characterized, at least for x = 1 and x = 3, as solids1. The purpose of this communication is to indicate that titanium (IV) ethoxide is a tetramer in the solid, and hence that this long-awaited X-ray analysis of a titanium (IV) alkoxide not only fails to confirm one of the proposed structures, but also makes unreasonable the assumption, implicit in much of the recent discussions, that the species in solution are identical with those precipitated from solution.
It’s endoderm...definitively!

Evaluation of: D’Amour, KA, Agulnick AD, Eliazer S et al.: Efficient differentiation of human embryonic stem cells to definitive endoderm. Nat. Biotech. 23, 1534–1541 (2005) [1] . Human embryonic stem cells (hESCs) offer great promise in the area of regenerative medicine because of their potential to generate vast numbers of transplantable cell types that can be used to cure degenerative diseases. The development of cell therapies for a wide variety of disease states has been severely hampered however, by the inability to control differentiation of hESCs. One area this problem applies to is the generation of pancreatic β-cells. Restoration of β-cell function in diabetic patients, by transplantation of β-cells derived from hESCs, is thought to have potential as a therapeutic strategy. A major problem however, in generating β-cells from hESCs, has been the inability to efficiently generate definitive endoderm – the precursor cell type that gives rise to pancreatic lineages in addition to those of the liver,...
Effects of 3D magnetic perturbations on toroidal plasmas

Small three-dimensional (3D) magnetic field perturbations have many interesting and possibly useful effects on tokamak and quasi-symmetric stellarator plasmas. Plasma transport equations that include these effects, most notably on diamagnetic-level toroidal plasma flows, have recently been developed. The 3D field perturbations and their plasma effects can be classified according to their toroidal mode number n: low n (say 1–5) resonant (with field line pitch, q = m/n) and non-resonant fields, medium n (~20, due to toroidal field ripple) and high n (due to microturbulence). Low n non-resonant fields induce a neoclassical toroidal viscosity (NTV) that damps toroidal rotation throughout the plasma towards an offset rotation in the counter-current direction. Recent tokamak experiments have generally confirmed and exploited these predictions by applying external low n non-resonant magnetic perturbations. Medium n toroidal field ripple produces similar effects plus possible ripple-trapping NTV effects and ion direct losses in the edge. A low n (e.g. n = 1) resonant field is mostly shielded by the toroidally rotating plasma at and inside the resonant (rational) surface. If it is large enough it can stop plasma rotation at the rational surface, facilitate magnetic reconnection there and lead to a growing stationary magnetic island (locked mode), which often causes a plasma disruption. Externally applied 3D magnetic perturbations usually have many components. In the plasma their lowest n (e.g. n = 1) externally resonant components can be amplified by kink-type plasma responses, particularly at high β. Low n plasma instabilities (e.g. resistive wall modes, neoclassical tearing modes) cause additional 3D magnetic perturbations in tokamak plasmas. Tearing modes in their nonlinear (Rutherford) regime bifurcate the topology and form magnetic islands. Finally, multiple resonant magnetic perturbations (RMPs) can, if not shielded by plasma rotation effects, cause local magnetic stochasticity and increase plasma transport in the edge of H-mode plasmas. These various effects of 3D fields can be used to modify directly the plasma toroidal rotation (and possibly transport via multiple RMPs for controlling edge localized modes) and indirectly anomalous plasma transport. The present understanding and modelling of these various 3D magnetic field perturbation effects including for test blanket modules in ITER are summarized. Finally, implications of the present understanding and key open issues for developing a predictive capability of them for ITER are discussed.
The use of carbon black‐supported sulfuric acid to initiate the cationic polymerization of cyclic ketene acetals

Stable polymers were made by the cationically initiated 1,2-polymerization of cyclic ketene acetals employing heterogeneous, activated carbon-supported sulfuric acid catalysts. A methodology has been established for the preparation of the carbon black of different acidic strengths. By adjusting either the acid strength or the amount of carbon black used, cyclic ketene acetals with different activities can be polymerized efficiently to form stable high molecular weight polymers. This methodology will be a useful tool for polymerization, copolymerization, and studies of the relative reactivities of the cyclic ketene acetals. The polymer structures were determined by FTIR, 13C-NMR, and 1H-NMR studies. © 1996 John Wiley & Sons, Inc.
Leibniz on Hobbes's Materialism

Abstract This paper discusses Leibniz’s interpretation and criticism of Hobbesian materialism in the period 1698–1705. Leibniz had continued to be interested in Hobbes’s work, despite not engaging with it as intensively as he did earlier (around 1670). Leibniz offers an interpretation of Hobbes that explains Hobbes’s materialism as derived from his imagistic theory of ideas. Leibniz then criticizes Hobbes’s view as being based on a faulty theory of ideas, and as having problematic consequences, particularly with regard to what one says about God. Some of this criticism is found in the New essays , but equally significant is Leibniz’s correspondence with Damaris Masham, who proposed an argument for materialism very much like that which Leibniz attributed to Hobbes. The paper concludes by discussing the suggestion that Leibniz at this time, particularly in the New essays , himself adopted Hobbesian ideas. Though Leibniz did use some of Hobbes’s examples, and did think at this time that all souls were associated with bodies, the resulting position is still rather distant from Hobbesian materialism.
Surface Pressure and Precipitation Life Cycle Characteristics of PRE-STORM Mesoscale Convective Systems

Abstract Extensive observations of the May–June 1985 Oklahoma–Kansas Preliminary Regional Experiment for STORM-Central (OK PRE-STORM) are used to examine the life cycle characteristics of 16 mesoscale convective systems (MCSs). The primary focus is on the surface pressure, flow, and precipitation structures of the mess. It is found that despite the wide variety of initial precipitation structures of the MCSs, reputable patterns developed in 75% of the cases during their mature-to-dissipating stages. The precipitation structure at this later stage of the life cycle can be described as asymmetric, following the definition of Houze et al. Due to the variety of directions of movement, the systems are examined in a motion-relative quadrant perspective. One axis is along the direction of system motion and the other perpendicular to it, crossing at the center of the convective line. The asymmetry is characterized by 1) a leading convective line containing relatively weak cells on the northern end and a trailing ...
Quantitation of fluorescence energy transfer between cell surface proteins via fluorescence donor photobleaching kinetics

We describe practical aspects of photobleaching fluorescence energy transfer measurements on individual living cells. The method introduced by T. M. Jovin and co-workers (see, most recently, Kubitscheck et al. 1993. Biophys. J. 64:110) is based on the reduced rate of irreversible photobleaching of donor fluorophores when acceptor fluorophores are present. Measuring differences in donor photobleaching rates on cells labeled with donor only (fluorescein isothiocyanate-conjugated proteins) and with both donor and acceptor (tetramethylrhodamine-conjugated proteins) allows calculation of the fluorescence energy transfer efficiency. We assess possible methods of data analysis in light of the underlying processes of photobleaching and energy transfer and suggest optimum strategies for this purpose. Single murine B lymphocytes binding various ratios of donor and acceptor conjugates of tetravalent concanavalin A (Con A) and divalent succinyl Con A were examined for interlectin energy transfer by these methods. For Con A, a maximum transfer efficiency of 0.49 +/- 0.02 was observed. Under similar conditions flow cytometric measurements of donor quenching yielded a value of 0.54 +/- 0.03. For succinyl Con A, the maximum transfer efficiency was 0.36. To provide concrete examples of quantities arising in such energy transfer determinations, we present examples of individual cell data and kinetic analyses, population rate constant distributions, and error estimates for the various quantities involved.
Removal of Thin Cirrus Scattering Effects for Remote Sensing of Ocean Color From Space

Thin cirrus clouds frequently contaminate satellite images. These clouds are traditionally treated as aerosols in atmospheric correction processes for satellite remote sensing of ocean color. Through analysis of spectral imaging data covering a solar spectral region between approximately 0.4 and 0.9 μm and acquired with the Hyperspectral Imager for the Coastal Ocean (HICO) instrument currently on board the International Space Station, we have developed an empirical but very effective technique to remove thin cirrus effects from HICO data acquired over fairly clear ocean waters where the water leaving reflectances above 0.8 μm are close to zero. The development of the technique is based on this property and on the fact that cirrus reflectances in the 0.4-1.0-μm region are spectrally constant. The empirical technique is described, and sample results are presented. The same technique is applicable to thin cirrus corrections over clear water surfaces for other hyperspectral or multichannel imaging instruments covering similar spectral range.
FACTORS AFFECTING THE SHELL ASSESSMENT BEHAVIOUR OF THE HERMIT CRAB, CALCINUS TIBICEN(HERBST, 1791) (DECAPODA, PAGURIDEA)

Factors influencing shell assessment behaviour were studied in the hermit crab, Calcinus tibicen. Visual and chemical presence of potential competition significantly lengthened the duration of shell assessment. Shell genus occupied by the hermit crab also had a significant effect. Those in Astrea shells examined an offered Cerithium shell significantly longer than hermit crabs occupying Gerithium, Pisania, or Nerita shells. Shell deficit, the difference between optimal shell volume for the hermit crab and actual shell volume, did not have a significant effect on the behavior of the hermit crabs occupying Cerithium shells. For those in Pisania shells there was a negative correlation between shell deficit and shell examination; while crabs in Nerita and Astrea shells demonstrated a positive correlation between shell deficit and shell examination. Neither the sex of the individual crab nor the presence of a predator, Calappa flammea, had a significant effect on shell assessment behaviour.
Copper and cobalt complexes of carnosine and anserine: production of active oxygen species and its enhancement by 2-mercaptoimidazoles

Phosphate buffer solutions of two dipeptides prevalent in striated muscle, L-carnosine (beta-alanyl-L-histidine) and L-anserine (beta-alanyl-L-1-methylhistidine), produce active oxygen species as measured by bleaching of N,N-dimethyl-4-nitrosoaniline (RNO). Activity is enhanced 5-14-fold in the presence of 2-mercaptoimidazoles such as ergothioneine, carbimazole (3-methyl-2-mercaptoimidazole-1-carboxylate), methimazole (2-mercapto-1-methylimidazole) and 2-mercaptoimidazole but only slightly by thiourea and dimethylthiourea. Activity is proportional to carnosine concentration and to mercaptoimidazole concentration at a fixed concentration of the second component. A variety of imidazoles closely related to carnosine and anserine are inactive, even after addition of transition metal ions. Activity is moderately increased above the pKa of the carnosine imidazole ring (pH 7.2, 7.5 and 8.0) versus below the pKa (pH 6.5 and 6.8). Activity is slightly increased by addition of copper or cobalt ions but not by addition of ferrous or ferric ions. Activity is decreased by Chelex 100 pretreatment of phosphate buffer and stimulated when copper or cobalt ions are added to the chelated buffer but there is no significant stimulation by ferric ions. Catalase eliminates most activity but superoxide dismutase has little effect. We propose that metal-carnosine and metal-anserine complexes produce superoxide and also serve as superoxide dismutases with resultant accumulation of hydrogen peroxide. An unidentified radical produced from hydrogen peroxide subsequently bleaches RNO. From the biological distributions of carnosine, anserine and ergothioneine, we infer that deleterious effects are probably minimal under normal physiological circumstances due to tissue and cellular compartmentalization and to sequestration of these compounds and transition metal ions.