cssi/SciSciGPT-SciSciNet huggingface dataset:
Column selectivity in high-performance liquid chromatography of substituted gem-dimethylcyclopropanes

Abstract High-performance liquid chromatographic (HPLC) separation of a series of gem-dimethylcyclopropanes was carried out in a variety of mobile phase and stationary phase systems. Comprehensive evaluation of column selectivity was made to identify chromatographic conditions under which various isomers could be resolved. In normal-phase HPLC on silica, retention data appeared to serve as good indicators for predicting relative polarity of the compounds in the solvent systems studied. For most cases, excellent baseline resolution of cis-trans mixtures was attained. The cis and trans components of chrysanthemol (CS) and ethyl chrysanthemate, however, were separated only with mobile phases of hexane and hexane-isopropanol (98:2), respectively. In reversed-phase HPLC, geometrical isomers of all but chrysanthemol were well resolved on octadecylsilica despite the poor selectivity of a propylphenylsilica column for these isomers under conditions used. The latter reversed-phase separation on propylphenylsilica succeeded only in two cases (RU-11679 and permethrin). Elution of cis and trans isomers in reversed-phase HPLC followed the same order as in normal-phase HPLC, except for the halogenated compounds where a reversal in elution order was observed. Among chiral stationary phases studied, the chiral polymeric packings, (+)-poly(triphenylmethylmethacrylate) exhibited the highest selectivity for compounds containing aromatic groups on ester moieties. The halogen substituents in permethrin and baythroid seemed to have adverse effects on the chiral recognition process. In HPLC on β-cyclodextrin-bonded silica, separations of diastereomeric (+)-cis- and (+)-trans-allethrin, and cis- and trans-chrysanthemol demonstrated unique examples of unusual selectivity of β-cyclodextrin-bonded silica for isomers that virtually remained indiscernible by all other HPLC methods investigated. The percentage of β-cyclodextrin in the bonded phase had dramatic influence on the α values of certain isomeric pairs. Increasing the percentage β-cyclodextrin in the bonded phase somewhat favored the separation of some optical antipodes.
Optimal channel selection for spectrum-agile low-power wireless packet switched networks in unlicensed band

This paper addresses the problem of optimal channel selection for spectrum-agile low-powered wireless networks in unlicensed bands. The channel selection problem is formulated as a multiarmed bandit problem enabling us to derive the optimal selection rules. The model assumptions about the interfering traffic that motivates this formulation are also validated through 802.11 traffic measurements as an example of a packet switched network. Finally, the performance of the optimal dynamic channel selection is investigated through simulation. The simulation results show that the proposed algorithm consistently tracks the best channel compared to other heuristic schemes.
The Egr transcription factor family: From signal transduction to kidney differentiation

Extracellular "signals" in the form of neurotransmitters, growth factors, hormones, and matrix are known to be key modulators of cellular phenotype. These agents lead to the generation of second messenger signals in the plasma membrane and cytosol. In turn, these biochemical events modulate the expression of a set of so-called immediate-early genes (IEG), whose induction does not require de novo protein synthesis. Several years ago, we and others identified several IEGs [reviewed in 1 and 2]. Of particular interest to our laboratory has been a subset of IEGs that encode transcription factors, since as such they might: (1) be the targets for second messenger events, and (2) activate or repress the transcription of critical genes required to effect a particular cellular phenotype. Thus, immediate-early transcription factors (IETF) should couple short-term responses in the form of second messenger events to long-term changes in gene expression instrumental in altering phenotype.
Planning, delivery, and quality assurance of intensity-modulated radiotherapy using dynamic multileaf collimator: a strategy for large-scale implementation for the treatment of carcinoma of the prostate.

Purpose: To improve the local control of patients with adenocarcinoma of the prostate we have implemented intensity modulated radiation therapy (IMRT) to deliver a prescribed dose of 81 Gy. This method is based on inverse planning and the use of dynamic multileaf collimators (DMLC). Because IMRT is a new modality, a major emphasis was on the quality assurance of each component of the process and on patient safety. In this article we describe in detail our procedures and quality assurance program. Methods and Materials: Using an inverse algorithm, we have developed .atreatment plan consisting five intensity­ modUlated (1M) photon fields that are delivered with DMLC. In the planning stage, the planner specifies the number of beams and their directions, and the desired doses for the target, the normal organs and the "overlap" regions. Then, the inverse algorithm designs intensity profiles that best meet the specified criteria. A second algorithm determines the leaf motion that would produce the designed intensity pattern and produces a DMLC file as input to the MLC control computer. Our quality assurance program for the planning and treatment delivery process includes the following components: 1) verification of the DMLC field boundary on localization port film, 2) verification that the leaf motion of the DMLC file produces the plauned dose distribution (with an independent calculation), 3) comparison of dose distribution produced by DMLC in a 8at phantom with that calculated by the treatment planning computer for the same experimental condition, 4) comparison of the planned leaf motions with that implemented for the treatment (as recorded on the MLC log files), 5) confirmation of the initial and final positions of the MLC for each field by a record-and-verify system, and 6) in vivo dose measurements. Results: Using a five-field IMRT plan we have customized dose distribution to conform to and deliver 81 Gy to the PTV. In addition, in the overlap regions between the PTV and the rectum, and between the PTV and the bladder, the dose is kept within the tolerance of the respective organs. Our QA checks show acceptable agreement between the planned and the implemented leaf motions. Correspondingly, film and TLD dosimetry indicates that doses delivered agrees with the planned dose to within 2%. As of September 15, 1996, we have treated eight patients to 81 Gy with IMRT. Conclusion: For complex planning problems where the surrounding normal tissues place severe constraints on the prescription dose, IMRT provides a powerful and efficient solution. Given a comprehensive and rigorous quality-assurance program, the intensity-modulated fields can be efficaciously and accurately delivered using DMLC. IMRT treatment is now ready for routine implementation on a large scale in our clinic. © 1997 Elsevier Science Inc. Radiotherapy, Prostate cancer, Intensity modulation, Dynamic multileaf collimator, DMLC.
Fast detection and characterization of organic and inorganic gunshot residues on the hands of suspects by CMV-GC–MS and LIBS

Abstract A rapid method for the characterization of both organic and inorganic components of gunshot residues (GSR) is proposed as an alternative tool to facilitate the identification of a suspected shooter. In this study, two fast screening methods were developed and optimized for the detection of organic compounds and inorganic components indicative of GSR presence on the hands of shooters and non-shooters. The proposed methods consist of headspace extraction of volatile organic compounds using a capillary microextraction of volatiles (CMV) device previously reported as a high-efficiency sampler followed by detection by GC–MS. This novel sampling technique has the potential to yield fast results (
Reliability of Grade-Point Averages

(1964). Reliability of Grade-Point Averages. The Journal of Educational Research: Vol. 57, No. 8, pp. 428-430.
Agreement among observers classifying larval sea lamprey ( Petromyzon marinus ) habitat

Abstract Estimates of larval sea lamprey ( Petromyzon marinus ) abundance are used to rank Great Lakes tributaries for lampricide treatment. Observers subjectively stratify habitat into three categories: type I = preferred, type II = acceptable, type III = unacceptable. Agreement was evaluated among eight observers classifying habitats in small discrete plots in two Lake Superior tributaries, the Rock and Chocolay rivers, and among four observers classifying and measuring the amount of each habitat type along random transects in the Rock River. Agreement among the eight observers classifying habitat plots was high (Chocolay, κ = 0.742 and Rock, κ = 0.785). The amounts of types I, II, and III habitat estimated were statistically different among observers. However, the amount of variability found in the classification and measurement of habitat by observers had little effect on the ranking of 51 streams considered for lampricide treatment.
Tufted hair folliculitis

A case of scarring alopecia presenting as two circumscribed, tender and inflamed areas in the occiput with residual tufted follicles is reported. Each tuft comprised 10 to 15 normal-appearing hairs arising from individual hair follicles in the reticular dermis or subcutaneous fat, converging toward a single orifice in the epidermis. The initial pathologic finding was inflammation and scarring of the papillary and mid dermis with almost total sparing of the hair follicles in the subcutaneous fat. Successful treatment was achieved by surgical excision of the two areas. It is suggested that the areas of tufting represented nevoid lesions that underwent inflammation and scarring.
Characterization and compensation of discrete-time non-minimum-phase systems for precision tracking control

Abstract The objective of this study is to characterize the unstable zeros of discrete-time non-minimum-phase systems and to compensate the gain and phase errors induced by unstable zeros for tracking control. These two objectives are attempted via examining the frequency response of unstable zeros. The gain error and phase shift induced by unstable zeros are first presented. It is well known that they are undesirable and cannot be cancelled directly via the method of pole-zero cancellation. Through investigating the characteristics of unstable zeros, a systematic approach is then given to compensate the gain and phase errors induced by unstable zeros. Using this approach, both a simple tracking control method and a precision tracking control method are proposed. The design procedure is presented and the design formulae are given. Simulation results are presented to illustrate the effectiveness of the proposed methods.
Students’ Understanding Is Enhanced Through Molecular Modeling

Integration of molecular modeling into General Chemistry lab encourages students to dually process molecular concepts both verbally and pictorially. When students are tested utilizing questions not previously encountered the dual processing of information can contribute to a transfer to knowledge. General Chemistry students utilized molecular modeling in lab and a comparison of a treatment and nontreatment group during two semesters is presented for a pretest, posttest, and on semester exam questions. The treatment group tested significantly higher than the nontreatment group on both the posttest and semester exam questions related to molecular concepts illustrating that there was a transfer of knowledge.
Reply to Young

Lefebvre's statement succinctly outlines the crux of the debate between Professor McQuarie and myself, the gist of which Professor Young has aptly identified. There is little doubt that Lefebvre sees dialectical materialism as including all of the various characteristics he mentions. My debate with Professor McQuarie attempted to balance what I saw as being an inordinate emphasis on science, causality, form of knowledge, and becoming aware of the given world, to the exclusion of philosophy, world-view, attitude toward life, and a will to transform this world (Wardell, 1979). In other words, Professor McQuarie's (1978) original article stressed a historical-materialistic reading of Marx, which I countered with a dialectical-materialistic reading of Marx. Professor Young has judiciously stepped in between Professor McQuarie and myself in order to help us, as well as others, move beyond the issues of the debate. Having no basic quarrel with Professor Young's comment, I would like to build upon his observations, hoping to elaborate his already constructive remarks. The notions of method, science and praxis are the focus of this brief reply. Professor Young correctly points out the differences between prehistory and history, each being organized around fundamentally different social relations of production. The question then becomes: is it necessary to have a different method of scientific inquiry for prehistorical societies than for historical societies? Professor Young is not very precise on this point, and consequently, some elaboration is necessary. Lefebvre's statement seems intent on emphasizing the synthesis of science with philosophy and causal analysis with a world-view, etc. Underlying this, there is the notion of a dialectical method which, regardless of the historical circumstances, guides meaningful, empirical analysis. The method itself involves orienting notions concerning production, contradiction, and totality (Wardell and Benson, 1979). For Lefebvre as for Marx, the dialectical method is a means of constructing historically grounded theory about societies; theories are the result of supplying historical concreteness to the method. The application of the method to particular historical relations is the requirement of scientific inquiry. Thus, a class analysis is of extreme importance within a capitalist arrangement where the basic organizing relationship of society exists between the laboring and capitalist classes. Given the hegemony of this relationship, there may be good reason to view this society from a systems standpoint.
The isoelectronic series ScF through ThO—I notes on the band spectra of TiO, HfO and ThO

Abstract The band spectra of TiO, HfO and ThO are treated, especially for later use in connection with the isoelectronic (in valence electrons) series ScF, TiO, ZrO, HfO and ThO. Franck-Condon factors and r-centroids for 12 HfO and ThO band systems are presented. Some recommendations for future spectral studies on UO are given, based on ThO results, since ThO apparently is the only diatomic oxide of the actinides to have known electronic band spectra.
Marginal models for clustered time to event data with competing risks using pseudovalues

Many time-to-event studies are complicated by the presence of competing risks and by nesting of individuals within a cluster, such as patients in the same center in a multi-center study. Several methods have been proposed for modeling the cumulative incidence function with independent observations. However, when subjects are clustered, one needs to account for the presence of a cluster effect either through frailty modeling of the hazard or subdistribution hazard, or by adjusting for the within-cluster correlation in a marginal model. We propose a method for modeling the marginal cumulative incidence function directly. We compute leave-one-out pseudo-observations from the cumulative incidence function at several time points. These are used in a generalized estimating equation to model the marginal cumulative incidence curve, and obtain consistent estimates of the model parameters. A sandwich variance estimator is derived to adjust for the within cluster correlation. The method is easy to implement using standard software once the pseudo-values are obtained, and is a generalization of several existing models. Simulation studies show that the method works well to adjust the standard error for the within cluster correlation. We illustrate the method on a dataset looking at outcomes after bone marrow transplantation.
Dextran coated bismuth–iron oxide nanohybrid contrast agents for computed tomography and magnetic resonance imaging

Bismuth nanoparticles have been proposed as a novel CT contrast agent, however few syntheses of biocompatible bismuth nanoparticles have been achieved. We herein report the synthesis of composite bismuth–iron oxide nanoparticles (BION) that are based on a clinically approved, dextran-coated iron oxide formulation; the particles have the advantage of acting as contrast agents for both CT and MRI. BION were synthesized and characterized using various analytical methods. BION CT phantom images revealed that the X-ray attenuation of the different formulations was dependent upon the amount of bismuth present in the nanoparticle, while T2-weighted MRI contrast decreased with increasing bismuth content. No cytotoxicity was observed in Hep G2 and BJ5ta cells after 24 hours incubation with BION. The above properties, as well as the yield of synthesis and bismuth inclusion efficiency, led us to select the Bi-30 formulation for in vivo experiments, performed in mice using a micro-CT and a 9.4 T MRI system. X-ray contrast was observed in the heart and blood vessels over a 2 hour period, indicating that Bi-30 has a prolonged circulation half-life. Considerable signal loss in T2-weighted MR images was observed in the liver compared to pre-injection scans. Evaluation of the biodistribution of Bi-30 revealed that bismuth is excreted via the urine, with significant concentrations found in the kidneys and urine. In vitro experiments confirmed the degradability of Bi-30. In summary, dextran coated BION are biocompatible, biodegradable, possess strong X-ray attenuation properties and also can be used as T2-weighted MR contrast agents.
Shape estimation for online diameter calibration in Czochralski silicon crystal growth

The diameter setpoint of a growing crystal in the silicon Czochralski process is a key cost parameter, whose optimal choice depends in part upon the diameter calibration accuracy. Measurement of the crystal diameter during solidification is made remotely, due to high temperatures and vacuum vessel design. Vision systems for diameter control detect the diameter of the bright ring reflection from the silicon melt surface at the crystal meniscus, rather than the actual crystal diameter. Distortion due to the bright ring measurement would result in a destabilizing nonlinear diameter measurement even if the crystal diameter response were linear. Using a published model of the meniscus shape, two and three-dimensional modeling of the bright ring is performed, and simple approximations are made to predict the bright ring bias as a function of diameter slope. Tracking of a diameter maximum during vertical translation could provide a calibration measure, given accurate translation data. The use of deformable templates or snakes is suggested for tracking the diameter maximum, and is bench-tested to provide estimates of on-line calibration accuracy, a key parameter for selection of the optimum diameter setpoint. Implementation of the modified calibration strategy requires corrections for camera distortion, crystal thermal expansion and window diffraction.
A New Series of Spectrum Lines

WITH a long hydrogen tube, viewed end on, as a source, lines have been observed at 4.05μ and 2.63μ, which, according to Bohr's theory, may be explained as due to an electron falling from the fifth to the fourth and from the sixth to the fourth rings respectively, forming the first two members of a new series.
Extracellular signal-regulated kinase (ERK) 5 is necessary and sufficient to specify cortical neuronal fate

Multipotent cortical progenitor cells differentiate into neurons and glial cells during development; however, mechanisms governing the specification of progenitors to a neuronal fate are not well understood. Although both extrinsic and intrinsic factors regulate this process, little is known about kinase signaling mechanisms that direct neuronal fate. Here, we report that extracellular signal-regulated kinase (ERK) 5 is expressed and active in proliferating cortical progenitors. Lentiviral gene delivery of a dominant negative ERK5 or dominant negative MAP kinase kinase 5 reduced the number of neurons generated from rat cortical progenitor cells in culture, whereas constitutive activation of ERK5 increased the production of neurons. Furthermore, when cortical progenitor cells were treated with ciliary neurotrophic factor, which induces precocious glial differentiation, ERK5 activation still promoted neuronal fate while suppressing glial differentiation. Our data also indicate that ERK5 does not directly regulate proliferation or apoptosis of cultured cortical progenitors. We conclude that ERK5 is necessary and sufficient to stimulate the generation of neurons from cortical progenitors. These results suggest a previously uncharacterized function for ERK5 signaling during brain development and raise the interesting possibility that extrinsic factors may instruct cortical progenitors to become neurons by activating the ERK5 pathway.
A multidimensional pseudospectral method for optimal control of quantum ensembles

In our previous work, we have shown that the pseudospectral method is an effective and flexible computation scheme for deriving pulses for optimal control of quantum systems. In practice, however, quantum systems often exhibit variation in the parameters that characterize the system dynamics. This leads us to consider the control of an ensemble (or continuum) of quantum systems indexed by the system parameters that show variation. We cast the design of pulses as an optimal ensemble control problem and demonstrate a multidimensional pseudospectral method with several challenging examples of both closed and open quantum systems from nuclear magnetic resonance spectroscopy in liquid. We give particular attention to the ability to derive experimentally viable pulses of minimum energy or duration.
Explaining U.S. Farm Policy in 1996 and Beyond: Changes in Party Control and Changing Market Conditions

U.S. farm policy underwent dramatic change in 1996, when Congress passed and the president signed the Federal Agricultural Improvement and Reform (FAIR) Act. Under FAIR, targetprice deficiency payments and annual landidling programs are to be eliminated for at least the next seven years, and are to be replaced with a fixed schedule of "production flexibility contract payments," completely decoupled from future market prices or planting decisions. What triggered this radical policy instrument change? The necessary conditions were twofold: Republican Party control of both the House and Senate in 1995-96, plus a rapid runup in market commodity prices. Other factors, including the 1986-94 Uruguay Round of GATT negotiations, acute federal budget pressures, and the possible emergence of a new market-oriented farm policy consensus proved far less important to the outcome. The crucial role of rising market prices explains why changes to the traditional farm price-support policies were enacted while other farm programs, and most nonfarm social entitlements, remained impervious to modification by the new political majorities in the 104th Congress. Two questions then arise. First, what would a counterfactual 1995-96 farm bill have looked like without either high prices or Republican control? Second, if market prices should fall in the years ahead, or if Democrats regain control of Congress, will the provisions of FAIR be able to survive?
Supporting Early Childhood Educators through Professional Development Partnerships.

This article summarizes the findings of a study that examined instruction in early childhood classrooms where teachers participated in high-quality, sustained, and intensive professional development through an Early Childhood Educator Professional Development partnership on literacy practices essential to school success. Comparisons made between teachers who participated in the professional development program and those who did not found consistent differences in instructional practices. Practical implications of the findings for early literacy teachers are discussed.
The effect of gestational age on symptom severity in children with autism spectrum disorder.

Between 2006 and 2010, two research-validated instruments, Social Communication Questionnaire (SCQ) and Social Responsiveness Scale (SRS) were filled out online by 4,188 mothers of Autism Spectrum Disorder (ASD) children, aged 4–21, as part of voluntary parental participation in a large web-based registry. Univariate and multivariate linear regression analysis (adjusted for child’s sex, ability to verbalize, categorical IQ score, and fetal growth rate) demonstrated significantly higher SCQ and SRS scores for ASD children of both preterm ( 42 weeks) gestational age (GA) compared to ASD children of normal GA, thus indicating that both preterm and post-term children manifest increased ASD symptomatology. Normal GA at birth appears to mitigate the severity of autistic social impairment in ASD children.
Intermittent Occlusion System

A deformable cuff attached to a hydraulic activating mechanism provides a system suitable for intermittently occluding a collapsible tubular structure. When the apparatus in the system is constructed of materials such as silicon rubber and stainless steel, the system is chronically implantable. The system is designed so that it can be externally controlled after implantation.
A Weighted Generalized Maximum Entropy Estimator with a Data-driven Weight

The method of Generalized Maximum Entropy (GME), proposed in Golan, Judge and Miller (1996), is an information-theoretic approach that is robust to multicolinearity problem. It uses an objective function that is the sum of the entropies for coefficient distributions and disturbance distributions. This method can be generalized to the weighted GME (W-GME), where different weights are assigned to the two entropies in the objective function. We propose a data-driven method to select the weights in the entropy objective function. We use the least squares cross validation to derive the optimal weights. MonteCarlo simulations demonstrate that the proposedW-GME estimator is comparable to and often outperforms the conventional GME estimator, which places equal weights on the entropies of coefficient and disturbance distributions.
Revisiting UN Peacekeeping in Rwanda and Sierra Leone

The end of the Cold War witnessed a plethora of new civil wars springing up across the world, particularly in sub-Saharan Africa. Marked by ethnic strife and multiple warring parties, many of these...
Determination of left ventricular chamber stiffness from the time for deceleration of early left ventricular filling.

Background A noninvasive measure of left ventricular (LV) chamber stiffness (KLV) would be clinically useful. Our theoretical analysis predicts that KLV can be calculated from the time for deceleration of LV early filling (tdec) by \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \[K\_{LV}{=}\frac{{\rho}\ {\cdot}\ L}{A}\ {\cdot}\ (\frac{{\pi}}{2}\ {\cdot}\ \frac{1}{t\_{dec}})^{2}\] \end{document} where ρ=density of blood, L=effective mitral length, and A=mitral area. Methods and Results We tested this hypothesis in eight conscious dogs instrumented for measurement of LV pressure (P) with use of a micromanometer and volume (V) with use of sonomicrometers. KLV was determined as the slope of the late diastolic portion of the LV P-V loop. KLV was varied from 0.99±0.35 to 2.58±0.92 mm Hg/mL with use of three graded doses of phenylephrine. We assumed that ρ=1.0 and that L/A=3.4. Thus, we predicted that KLV=(0.08/tdec)[2][1] . The LV filling pattern was determined from the derivative of LV volume (dV/dt). tdec was measured from peak early filling to the end of early filling. Predicted KLV and actual KLV were closely correlated ( r =.94, SEE=0.06 mm Hg/mL, P <.05). The regression line was close to the line of identity (slope=0.95, intercept=0.13 mm Hg/mL). Dobutamine did not alter the relation between tdec and KLV. tdec determined from the mitral valve flow velocity measured with Doppler echocardiography correlated well with that measured by dV/dt ( r =.89, P <.01) but was 0.02 seconds longer. KLV-calculated tdec from the corrected Doppler tdec provided a good estimate of measured KLV ( r =.75, SEE=0.5 mm Hg/mL, P <.01). Conclusions LV chamber stiffness can be determined from the time for deceleration of LV early filling, which can be measured noninvasively. [1]: #ref-2
Bacteroides fragilis toxin 2 damages human colonic mucosa in vitro.

BACKGROUND—Strains of Bacteroides fragilis producing a 20 kDa protein toxin (B fragilis toxin (BFT) or fragilysin) are associated with diarrhoea in animals and humans. Although in vitro results indicate that BFT damages intestinal epithelial cells in culture, the effects of BFT on native human colon are not known. AIMS—To examine the electrophysiological and morphological effects of purified BFT-2 on human colonic mucosa in vitro. METHODS—For resistance (R) measurements, colonic mucosa mounted in Ussing chambers was exposed to luminal or serosal BFT-2 (1.25-10 nM) and after four hours morphological damage was measured on haematoxylin and eosin stained sections using morphometry. F actin distribution was assessed using confocal microscopy. RESULTS—Serosal BFT-2 for four hours was four-, two-, seven-, and threefold more potent than luminal BFT-2 in decreasing resistance, increasing epithelial 3H-mannitol permeability, and damaging crypt and surface colonocytes, respectively (p<0.05). Confocal microscopy showed reduced colonocyte F actin staining intensity after exposure to BFT-2. CONCLUSIONS—BFT-2 increases human colonic permeability and damages human colonic epithelial cells in vitro. These effects may be important in the development of diarrhoea and intestinal inflammation caused by B fragilis in vivo. Keywords: B fragilis toxin; toxin mediated colonocyte damage; actin filaments; transepithelial resistance; morphometry
Strength of tensor force and s-d-shell effective interactions.

The {ital s}-{ital d}-shell effective interaction is derived from the Bonn {ital NN} potential, using a {ital G}-matrix folded-diagram method. It is found that due to the relatively weak-tensor-force characteristic for the Bonn potential, the effective interaction matrix elements, particularly those with isospin {ital T}=0, come out generally more attractive than in previous derivations which were based on conventional local strong-tensor-force {ital NN} potentials. This renders the results obtained with the Bonn potential in considerably better agreement with the recent {ital s}-{ital d}-shell matrix elements of Wildenthal.
Brightness of luminance distributions with gradual changes.

Abstract The perception or gradually changing luminance distributions was investigated. Luminance changed across the radius of a disk by a linear, quadratic, or cubic function with varying magnitudes. Subjects selected matching luminances for the inner and outer edges of each stimulus. The threshold for reporting that the inner and outer matches were different occurred at approximately 20% contrast between those regions. This threshold did not vary with the particular function which described the luminance distribution. Further, as the magnitude of luminance change across the stimulus increased, subjects judged the inner and outer edges to differ more in brightness. Matching luminances also depended upon the background configuration with greater differences perceived across the disk radius when the surround and center dot of the stimulus were of opposite, rather than the same, luminance. These results indicate that models of brightness must consider all luminance changes in the stimulus, not just changes of a particular type such as second differences or changes at a luminance step.
Understanding Racial Differences in the Effects of Loans on Degree Attainment: A Path Analysis:

Recent trends in the financing of higher education have increased the urgency of understanding how financial aid affects degree attainment among college students. Specifically, increased reliance on loans in the composition of financial aid packages renders it critical for policymakers and institutional leaders to understand the impact of borrowing on degree attainment. This study was aimed at understanding the complex relationship between loan amounts and degree completion using path modeling techniques. Results reveal that the process by which loans influence attainment is complex and varies across racial groups. The direct effect of loans on degree attainment was positive for Black students and negative for their Asian, Latina/o, and White counterparts. That direct effect was strongest for Latina/o students. Loan amounts also exhibited several indirect influences on attainment, via their effects on various mediating variables, among all four groups. Implications for research, policy, and practice are d...
Let's Get Rid of Dumb Exploration

It takes only a modest amount of imagination—or a dollop of paranoia—to conclude that a concerted effort is underway to get rid of petroleum exploration in the United States. All of the indicators of exploration activity support that conclusion (Figure 1). Since the historic peak of exploration activity in 1981, the number of new field wildcat wells drilled annually has dropped 68 percent, annual expenditure on new field wildcats has plummeted 77 percent, the average domestic rotary rig count fell by 76 percent, and the average number of geophysical crews working dwindled by 73 percent.
A Derivation of the Spectra of N-Ary Orthogonal Comtinuous-Phase FSK Waveforms for ELF/VLF Communications

The power spectral density of continuous-phase minimum-bandwidth waveforms composed from a set of N mutuallyorthogonal chips (pulsed sinusoids of equal amplitude and duration and constant frequency) is derived. The spectrum and its derivation for this class of signals are of particular interest in highpower extremely low frequency/very low frequency (ELF/VLF) communications where noise immunity is a prime consideration, but the signal bandwidth and transients at the transmitting antenna must be minimized. Exact formulas are also given without derivation for wider bandwidth signals in the same class but of less practical importance. Although the power spectra of more general binary signals are already known, the special case presented here permits a much simpler derivation than that given in an earlier paper [1]. In the N -ary case a previously derived formula for the spectra of continuous-phase multilevel FM signals [2] is augmented and evaluated to explicitly yield new spectral formulas useful in describing the frequency-hopping mode.
Percutaneous radiofrequency ablation for the treatment of hepatocellular carcinoma: long-term follow up, efficacy and prognostic factors.

We strongly recommend to the readers of Annals of Gastroenterology two interesting studies by Shiina et al [1] and Kim et al [2] on the outcome of radiofrequency ablation and the prognostic factors which seem to govern it for the treatment of hepatocellular carcinoma (HCC). HCC is the third leading cause of cancer-related death and the fifth - sixth most common cancer [1-3]. Transplantation and surgical resection are the therapies of choice for HCC [4,5]. However, shortage of organ donors restricts liver transplantation, whilst only one fifth of HCC patients are candidates for surgical resection [1,2]. For different reasons (patient refusal, impaired liver function, co-morbidities) surgical resection cannot be considered an option for the majority of HCC patients. In this group of patients, percutaneous ablation therapies act as attractive alternatives with similar success and survival rates and significantly lower post-therapeutic pain and other complications. Furthermore, percutaneous therapies can be applied in patients who are on the waiting list for liver transplantation in order to decrease drop-out rates due to disease progression whenever the waiting is expected to be longer than 6 months [6]. In the two aforementioned studies, the authors report their long-term experience (10-year follow-up period) on radiofrequency ablation (RFA) for HCC lesions focusing on clinical and technical outcomes, as well as on the analysis of potential prognostic factors. In their experience they used ultrasound-guided RFA either solely performed or combined with transarterial chemoembolization (TACE). In particular, Shiina et al [1] report 99.4% of complete tumor ablation (2964/2982 ablation sessions for 1170 HCC patients) with 5-and 10-year survival rates being 60.2% and 27.3%, respectively with a median follow up of 38.2 months. Complication rates were 2.2% per treatment (67/2982) with 0.003% mortality rate. Tumor size, number of tumor lesions and Child-Pugh class are the factors which affect survival. Kim et al [2] report 94.8% of technical success (1237/1305 patients) with 5- and 10-year survival rates being 59.7% and 32.3% respectively with a median follow up of 33.4 months. Complication rate was 2% (concerning major complications) with no reported procedure-related mortalities. Older age, Child-Pugh class, absence of antiviral therapy during follow up and presence of extra-hepatic recurrence are the factors which affect survival.
Distinct patterns of histone modifications at cardiac-specific gene promoters between cardiac stem cells and mesenchymal stem cells

Mesenchymal stem cells (MSCs) and cardiac stem cells (CSCs) possess different potential to develop into cardiomyocytes. The mechanism underlying cardiomyogenic capacity of MSCs and CSCs remains elu...
PHENOTYPIC PLASTICITY IN DRAPARNALDIA (CHLOROPHYTA: CHAETOPHORACEAE). I. EFFECTS OF THE CHEMICAL ENVIRONMENT1

Eight axenic isolates of Draparnaldia spp. were in defined media under controlled condidom of day length, light intensity and temperature to study effects of the nutrientions on genera; pheuotype and development of main text cells. Phosphate (0–6,8 mg/l P), magnesium (0-9.6 mg/l Mg), sulfate (1.2 –14.0 mg/l S) and chloride (0.2-48.2mg/l Cl) had no effect. Small, but significant, concentration-independent, isolate-specific differences due to sodium and patassium (as the phosphate salt) occured in main axis cell length. The presence of calcium (>1.7 mg/l) was required by all isolates for main axis differentiation. In the absence of calcium, only zoospores and stunted Stigeoclonium- like plants were produced. Nitrate (>5 mg/l N) depressed main axis cell size;at higher levels (> 15 mg/l N) hair prooduction was depressed and several isolates developed a very typical Cloniophora appearance, Several of the isolates did not produce typical Draparnaldia- like phenotypes under any of the chemical formulations tried; therefore, it is suggested that chemical factors alone do not account for either the phemotypec plasticity of Draparnaldia in the field or the failure of others to grow typical plants in culture.
Mechanism of Glomerular Hyperfiltration After a Protein Meal in Humans: Role of hormones and amino acids

OBJECTIVES Previous studies demonstrated that protein meals and amino acid (AA) infusions increase glomerular nitration rate (GFR) and renal plasma flow (RPF) and that somatostatin (SRIH) infusion inhibits these increments. We tested whether a single AA such as alanine could increase GFR and RPF and whether the changes in GFR and RPF could be explained on the basis of changes in glucagon, growth hormone (GH), and insulin. RESEARCH DESIGN AND METHODS In the first experiment, alanine was infused with or without SRIH in five normal subjects. In the second experiment, five other subjects were infused with SRIH on three separate occasions. In a control study, insulin, glucagon, and GH were given at replacement doses; in a hyperglucagonemia study, glucagon was given at a rate of 0.2 μ · kg −1 · h −1 (hypoglucagonemia); and in a high GH study, GH was given at a rate of 2 /μg · kg −1 · h −1 . GFR and RPF were measured using inulin and para-aminohippurate, respectively. RESULTS Alanine increased GFR and RPF, whereas SRIH inhibited these changes ( P CONCLUSIONS A single AA such as alanine increases GFR and RPF, and this increase is dependent on a factor inhibited by SRIH. Although GH, glucagon, and insulin are factors inhibited by SRIH, none of these factors explains the changes in RPF and GFR in our acute studies.
Mixed-mode cohesive-zone models for fracture of an adhesively bonded polymer–matrix composite

Abstract As a direct extension of previous mode-I work on the adhesion of composite joints, this paper uses a cohesive-zone approach to model the mixed-mode fracture of adhesive joints made from a polymer–matrix composite. Mode-II cohesive-zone parameters were obtained using sandwich end-notch flexure specimens. These parameters were used directly with the previously determined mode-I parameters to predict the fracture and deformation of mixed-mode geometries. It was shown that numerical simulations provided quantitative predictions for these geometries, including predictions for both the strengths of the joints and for the failure mechanisms. In conjunction with the earlier work, these results demonstrate the use of cohesive-zone approaches for the design of adhesively bonded composite joints, and indicate approaches for determining the relevant material properties to describe mixed-mode fracture.
A First Step towards Characterizing Stealthy Botnets

Botnets have become a top cyber threat. Existing studies on botnets have mainly focused on showing how to exploit certain characteristics of existing botnets to detect them. However, such detection mechanisms could be defeated by stealthy botnets that are designed to evade them. Therefore, it is important to understand the power of stealthy botnets so as to answer questions such as: What kinds of stealth techniques can survive what kinds ofdetection mechanisms? Towards the ultimate goal, this paper makes a first step with the aim to build fundamentalunderstandings of stealthy botnet Command and Control (C\&C).
Differences in Blood Volume Components Between Hyporesponders and Responders to Erythropoietin Alfa: The Heart Failure With Preserved Ejection Fraction (HFPEF) Anemia Trial

Abstract Background Hyporesponders to erythropoietin-stimulating agents (ESAs) have been associated with an increased subsequent risk of death or cardiovascular events. We hypothesized that subjects who are hyporesponsive to erythropoietin alfa would have higher plasma volumes and lower red cell deficits than subjects who are responsive to therapy. Methods As part of a prospective, single blind, randomized, placebo-controlled study comparing erythropoietin alfa with placebo in older adults (n = 56) with heart failure and a preserved ejection fraction (HFPEF), we performed blood volume analysis with the use of an indicator dilution technique with 131 iodine-labeled albumin. We evaluated differences in plasma volumes and red cell volumes in hyporesponders (eg, Results Nine of 28 subjects (32%) assigned to ESA were hyporesponders. Hyporesponders did not differ from responders nor control subjects by any baseline demographic, clinical, or laboratory parameter, including hemoglobin. Hyporesponders had a greater total blood volume expansion (1,264.7 ± 387 vs 229 ± 206 mL; P = .02) but less of a red cell deficit (−96.2 ± 126 vs −402.5 ± 80.6 mL; P = .04) and a greater plasma volume expansion (+1,360.8 ± 264.5 vs +601.1 ± 165.5 mL; P = .01). Among responders, the increase in hemoglobin with erythropoietin alfa was associated primarily with increases in red cell volume ( r = 0.91; P r = −0.55; P = .06). Conclusions Among older adults with HFPEF and anemia, hyporesponders to erythropoietin alfa had a hemodilutional basis of their anemia, suggesting that blood volume analysis can identify a cohort likely to respond to therapy.
Obsessive compulsive symptom dimensions and neuroticism: An examination of shared genetic and environmental risk

Individuals with obsessive compulsive disorder can display diverse and heterogeneous patterns of symptoms. Little is known about the relationship between obsessive-compulsive symptom (OCS) dimensions and normal personality traits, particularly those that increase risk for other internalizing disorders. In this study of 1,382 individuals from female-female twin pairs, we examined the relationship between self-report OCS dimensions derived from the Padua Inventory and Eysenck's personality traits neuroticism and extraversion. We conducted factor analysis to determine their phenotypic structure followed by twin analyses to determine their genetic and environmental sources of covariation. A three-factor solution, with dimensions corresponding to checking, aggressive obsessions, and contamination, was the best fit for the Padua OCS items. These dimensions were significantly and somewhat variably associated with neuroticism but negligibly associated with extraversion. The genetic correlations between neuroticism and these three OCS dimensions were moderate to high (0.66 with checking, 0.89 with aggressive obsessions, and 0.40 with contamination). However, the estimated genetic correlation between neuroticism and a unified latent OCS construct was smaller (0.32). Overall this study suggests that genetic, and to a smaller extent environmental, factors underlying neuroticism may act differentially as risk factors for OCS dimensions.
Can ultrasonography make identification of asymptomatic hyperuricemic individuals at risk for developing gouty arthritis more crystal clear

Hyperuricemia is the most important risk factor for gouty arthritis. The quandary is how to predict which patient with asymptomatic hyperuricemia will develop gouty arthritis. Can ultrasonography help identify hyperuricemic individuals at risk for developing gouty arthritis? In the previous issue of Arthritis Research & Therapy, Pineda and colleagues found ultrasonography changes suggestive of gouty arthritis in 25% of hyperuricemic individuals. These were found exclusively in hyperuricemic individuals but not in normouricemic patients. Ultrasonography may serve as a noninvasive means to diagnose gouty arthritis in hyperuricemic individuals who have yet to develop symptomatic gouty arthritis.
Asymptotic states in nonrelativistic models exhibiting infra-red divergences

A method related to that of Faddeev and Kulish to eliminate infra-red divergences is illastrated in some exactly solvable nonrelativistic models.
Spanning and Independence Properties of Finite Frames

The fundamental notion of frame theory is redundancy. It is this property which makes frames invaluable in so many diverse areas of research in mathematics, computer science, and engineering, because it allows accurate reconstruction after transmission losses, quantization, the introduction of additive noise, and a host of other problems. This issue also arises in a number of famous problems in pure mathematics such as the Bourgain-Tzafriri conjecture and its many equivalent formulations. As such, one of the most important problems in frame theory is to understand the spanning and independence properties of subsets of a frame. In particular, how many spanning sets does our frame contain? What is the smallest number of linearly independent subsets into which we can partition the frame? What is the least number of Riesz basic sequences that the frame contains with universal lower Riesz bounds? Can we partition a frame into subsets which are nearly tight? This last question is equivalent to the infamous Kadison–Singer problem. In this section we will present the state of the art on partitioning frames into linearly independent and spanning sets. A fundamental tool here is the famous Rado-Horn theorem. We will give a new recent proof of this result along with some nontrivial generalizations of the theorem.