cssi/SciSciGPT-SciSciNet huggingface dataset:
Pulsar–black hole binaries in the Galactic Centre

Binaries consisting of a pulsar and a black hole (BH) are a holy grail of astrophysics, both for their significance for stellar evolution and for their potential application as probes of strong gravity. In spite of extensive surveys of our Galaxy and its system of globular clusters, no pulsar–black hole (PSR–BH) binary has been found to date. Clues as to where such systems might exist are therefore important. We show that if the central parsec around Sgr A★ harbours a cluster of ∼25 000 stellar BHs (as predicted by mass-segregation arguments) and if it is also rich in recycled pulsar binaries (by analogy with globular clusters), then three-body exchange interactions should produce PSR–BHs in the Galactic Centre. Simple estimates of the formation rate and survival time of these binaries suggest that a few PSR–BHs should be present in the central parsec today. The proposed formation mechanism makes unique predictions for the PSR–BH properties: (1) the binary would reside within ∼1 pc of Sgr A★; (2) the pulsar would be recycled, with a period of ∼1 to a few tens of milliseconds, and a low magnetic field B≲ 1010 G; (3) the binary would have high eccentricity, e∼ 0.8, but with a large scatter and (4) the binary would be relatively wide, with semimajor axis ab∼ 0.1 −≳3 au. The potential discovery of a PSR–BH binary therefore provides a strong motivation for deep, high-frequency radio searches for recycled pulsars towards the Galactic Centre.
Reaction of Aryl Halides with π‐Allylnickel Halides: Methallylbenzene

Reaction of aryl halides with π-allylnickel halides: methallylbenzene reactant: 50.8 g. (38.5 ml., 0.298 mole) of nickel carbonyl solvent: 250 ml. of petroleum ether product: methallylbenzene reactant: Methallyl bromide intermediate: π-methallylnickel bromide byproduct: 1% 2,5-dimethyl-1,5-hexadiene byproduct: biphenyl product: β,β-dimethylstyrene Keywords: coupling; N,N-dimethylformamide; methallyl bromide, preparation of; π-methallylnickel bromide; nickel carbonyl, poison; nickel carbonyl, antidote
Hepatic fat and adenosine triphosphate measurement in overweight and obese adults using 1H and 31P magnetic resonance spectroscopy.

Hepatic magnetic resonance spectroscopy (MRS) is increasingly being applied to many areas of patient-oriented liver research (1). Proton MRS (1H MRS) can quantify triglyceride content in the liver (2) and has become well-established for this purpose (3). Phosphorus MRS (31P MRS) can evaluate complex metabolic processes in vivo and has been applied to many areas of clinical liver research, including investigations of cirrhosis, hepatitis, obstructive jaundice and hepatic energy homoeostasis (4–7). MRS uses standard magnetic resonance equipment, is noninvasive and imparts little risk on study subjects. Further, the data generated by 31P MRS are unique. For example, no other research modality can assess hepatic energy in vivo as indicated by hepatic adenosine triphosphate (ATP) levels. Despite these important attributes, some obstacles are faced by investigators interested in human hepatic MRS. Human hepatic MRS protocols, in particular 31P MRS protocols, can be technically challenging, time consuming and costly. There is considerable variation in data analysis techniques in the published literature, and all share the potential for systematic and random error (8). Perhaps most important, the reported intra- exam and intrasubject variability ranges widely in published studies (9, 10). Furthermore, the effect of fasting or time of day on hepatic ATP levels is uncertain. Accordingly, it is important to understand the technical factors associated with cost-efficient and successful MRS data acquisition and analysis. In this paper, we report our experience with both hepatic 1H and 31P MRS in a cohort of overweight and obese diabetic subjects enrolled in the Action for Health in Diabetes (Look AHEAD) study compared with healthy controls. We also report inter- and intra-observer variability in the evaluation of spectra, and the stability of MRS measurements through repeated examinations on healthy volunteers. We hypothesized that we could successfully complete 1H and 31P MRS in a reliable fashion in obese adults.
Infiltration on alluvial fans in arid environments: Influence of fan morphology

[1] Mountain-front recharge through highly permeable alluvial fans can be an important source of groundwater recharge in arid climates. To better understand the geomorphic factors (e.g., fan slope, fan area, active channel proportion of fan area, sediment permeability, and entrenchment of the active channel) that control flow and infiltration on alluvial fans, we developed a coupled numerical model of steady surface water flow and Green-Ampt-type infiltration. The model was applied to synthetic alluvial fans using random walkers to create connected distributary networks. The purpose of this approach is to predict where and how recharge occurs on fans as a function of fan morphology. Using the numerical model, we examined how the fan shape and the sequence of fan surfaces influenced where infiltration occurred on the fan. We also investigated how fan morphology influenced the partitioning of infiltration between the fan and the valley floor. Finally, we examined how infiltration influenced the spatial distribution of flooding. The greatest amount of infiltration occurred on low gradient fans where water spread laterally with shallower ponded water depths, although the large inundation area often included less permeable sediments outside of the active channel. The ratio of the incision depth to the input flow depth was an important predictor of the amount of infiltration. The greatest amount of infiltration occurred on fans with incision depths slightly smaller than the input flow depth. These results have implications for groundwater resource assessment and for development of monitoring networks on fans in arid environments.
Carbon-water-energy relations for selected river basins

A biophysical process-based model was run using satellite, assimilated and ancillary data for four years (1987-1990) to calculate components of total evaporation (transpiration, interception, soil and snow evaporation), net radiation, absorbed photosynthetically active radiation and net primary productivity over the global land surface. Satellite observations provided fractional vegetation cover, solar and photosynthetically active radiation incident of the surface, surface albedo, fractional cloud cover, air temperature and vapor pressure. The friction velocity and surface air pressure are obtained from a four dimensional data assimilation results, while precipitation is either only surface observations or a blended product of surface and satellite observations. All surface and satellite data are monthly mean values; precipitation has been disaggregated into daily values. All biophysical parameters of the model are prescribed according to published records. From these global land surface calculations results for river basins are derived using digital templates of basin boundaries. Comparisons with field observations (micrometeorologic, catchment water balance, biomass production) and atmospheric water budget analysis for monthly evaporation from six river basins have been done to assess errors in the calculations. Comparisons are also made with previous estimates of zonal variations of evaporation and net primary productivity. Efficiencies of transpiration, total evaporation and radiation use, and evaporative fraction for selected river basins will be presented.
Effect of Ring Size on Conformations of Aromatic Amine−DNA Adducts: The Aniline−C8 Guanine Adduct Resides in the B-DNA Major Groove

While the one-ring amine aniline (AN) has only slight genetic activity, the polycyclic aromatic amines 2-aminofluorene (AF) and 1-aminopyrene (AP) are significant mutagens and carcinogens. Moreover, the bulkier AP is more mutagenic per adduct than AF in the tetracycline-resistance gene of plasmid pBR322 [Melchior et al. (1994) Carcinogenesis 15, 889]. To elucidate possible conformational origins of the differing mutagenic effects of these three adducts, which may stem from their differing ring sizes, we have examined their conformations in two mutation-susceptible sequences from the above gene: TTGAG*GCCG (sequence I) and GAATG*GTGC (sequence II), where G* = C8-modified guanine. No experimental high-resolution NMR data are yet available for the aniline adduct in a DNA duplex. Minimized potential energy calculations were carried out, using the molecular mechanics program DUPLEX to explore the conformation space of these adducts. In the case of AN, a relatively unperturbed B-DNA helix with the amine in the...
Heteroantiserum against a subpopulation of human T lymphocytes

Abstract An anti-T cell antiserum (162) was raised to the cultured T acute lymphocytic leukemia cell line HSB2 previously precoated with antilymphocyte serum. Following absorption with cultured normal B cells antiserum 162 reacted with 30 to 70% of normal peripheral blood T lymphocytes (E-rosetting cells), and 100% of thymocytes, T chronic lymphocytic leukemia cells, and T acute lymphocytic leukemia cells. Quantitative absorption experiments indicated that 162 reacted against a common antigen(s) present on these cells. Antiserum 162 did not react with normal B lymphocytes, B cell lines, non-B non-T acute lymphocytic leukemia cells, acute myelocytic leukemia cells, B cell chronic lymphocytic leukemia cells, and T blast cells from the peripheral blood of a patient with Sezary syndrome. Two T acute lymphocytic leukemia cell lines were positive (HSB2 and 8402) and one (MOLT 4) was negative.
Linking hydrology and stream geochemistry in urban fringe watersheds

Summary Urbanization represents a dramatic example of human interference with the hydrological cycle. Changes to ground cover affect both the hydrological and geochemical characteristics in a watershed. Ecosystem degradation also occurs in undisturbed watersheds at the “urban fringe” due to regional atmospheric deposition. These urban fringe catchments can also serve as an upstream source of various chemical constituents into downstream (urban) river systems. The current study focuses on the impacts of regional urbanization in the upper Arroyo Seco watershed located on the eastern edge of the Los Angeles basin, where estimates of dry deposition are considered some of the highest in North America. Collected hydrologic, geochemical and atmospheric data were assessed at seasonal time scales to evaluate current hydrochemical dynamics. Stream water chemical composition in the upper Arroyo Seco watershed exhibits significant seasonal variability, particularly for [ NO 3 - ] . Almost all study solutes show dilution behavior. However, hydrologically enhanced behavior was observed for [ NO 3 - ] with increased concentrations during the wet season. Seasonal stream concentration–discharge relationships were developed using a hyperbolic dilution model. The developed model was then used to predict concentrations for observational gaps in stream water chemical composition, allowing for seasonal and annual mass loadings to be estimated for the downstream urban stream. The hydrological signal in the resultant chemical loads is extremely strong, especially during the wet season. Both observations and model predictions indicate the watershed is a sink for atmospheric nitrate and a source for various cations.
A Note on Mortgage Risk: Default vs. Loss Rates

This note reexamines the role of the loan-to-value ratio on mortgage risk. Whereas previous studies have focused on the default rate as a function of this term, this study considers the additional effect on the loss rate of defaulted loans. Because the dollar loss per amount originated is the product of the default rate and the loss rate on defaulted loans, the impact of the loan-to-value ratio on both the default and loss rates is crucial to explaining the impact of the loan-to-value ratio on mortgage risk. I find that both rates are significantly positively related to loan-to-value ratio and that the loss rate accounts for between 13% and 20% of total loan-to-value impact.
Announcing Change: Discourse, Uncertainty, and Organizational Control

AbstractEmbracing a meso-level approach to discourse and change, I examine relationships among organizational-level discourses in the days following a formal change announcement at an international data services organization. The findings of this study show how particular articulations of the future aligned with existing organizational meanings to constitute a discursive constellation that maintained – rather than changed – organizational meaning systems. These findings reimagine organizational control as a process of organizational-level discursive alignments that further naturalize organizational understandings by suppressing alternative ways to know an uncertain future. Conceptualizing organizational control in terms of meso-level discursive alignments has potential implications for both scholars and practitioners of organizational change by refocusing attention on the ways participants talk about change while remaining sensitive to how announcing change might enable discourses of ‘sameness’ rather tha...
The adsorption and dissociation of O 2 molecular precursors on Cu: the effect of steps

Abstract The adsorption and dissociation of dioxygen on Cu steps are studied using periodic self-consistent density functional theory (PW91-GGA) calculations. Cu steps are modeled with a Cu(2 1 1) surface. The results are compared with those on the flat Cu(1 1 1) surface. The adsorption of both atomic and molecular oxygen is enhanced on the stepped surface: the binding energy of atomic oxygen is −4.5 eV at its preferred site on the relaxed Cu(2 1 1) surface vs. −4.3 eV at its preferred site on the relaxed Cu(1 1 1) surface, and the binding energy of the molecular oxygen precursor is increased from ∼−0.6 to ∼−1.0 eV. Several possible O 2 dissociation paths at the edge of the Cu(2 1 1) step have been investigated. The activation energies range from 0.09 to 0.24 eV, comparable to a minimum activation energy of 0.20 eV found on Cu(1 1 1). However, compared to Cu(1 1 1) the paths on Cu(2 1 1) are stabilized in their entirety by the step by ∼0.5 eV in terms of initial state, transition state, and final state energies. The dissociation of O 2 precursors at the foot of the step is close to being barrier-less. Because of the small dissociation barrier on Cu(1 1 1), the effect of steps on O 2 dissociation is nevertheless not expected to be as pronounced as in other gas/metal systems.
A Wind-Driven Model Experiment of the Seasonal Cycle of the Main Thermocline in the Interior Midlatitude North Pacific

Abstract A wind-driven model experiment is designed to test the effectiveness of the classical wind-driven theory of Veronis and Stommel (1956) in explaining the phase and amplitude of the seasonal cycle of the main thermocline in the interior portion of the midlatitude North Pacific. The model is a two-layer quasi-geostrophic model on the β-plane. driven by the observed seasonal cycle of the wind-stress curl. It allows the first-mode baroclinic response to Ekman pumping by the wind stress curl, modified by baroclinic planetary (Rossby) wave effects. The horizontal phase and amplitude distributions of the seasonal cycle of temperature at 200 m over the interior midlatitude North Pacific from 25–45°N, 130°W–150°E, are determined based on XBT data collected by ship-of-opportunity from 1968–74. Quantitative comparison between these observed distributions of phase and amplitude with those of the model shows that the phase distributions have a pattern correlation of 0.72, while the amplitude distributions have...
On the Formation and Electropolymerization of a Star Copolymer With Peripheral Carbazoles

Utilizing a hyperbranched cored ring-opening polymerization of caprolactone, carbazole peripheral groups are extended to afford electropolymerizable star-like copolymers. Different arm lengths are obtained on the basis of different degrees of polymerization from the polyethyleneimine core. This is confirmed by NMR and Fourier transform IR (FTIR) spectroscopy, size-exclusion chromatography (SEC), and quantitative spectral characterization. Atomic force microscopy (AFM) imaging shows two distinct particle aggregation characteristics, before and after functionalization with carbazole groups. Cyclic voltammetry verifies the electrochemical cross-linking properties. The results indicate that the conformational freedom of the electroactive peripheral functional groups can be controlled. Moreover, an interesting “loop effect” together with solid-state polymerization is observed.
Forest structure and aboveground biomass in the southwestern United States from MODIS and MISR

article i nfo Red band bidirectional reflectance factor data from the NASA MODerate resolution Imaging Spectro- radiometer (MODIS) acquired over the southwestern United States were interpreted through a simple geometric-optical (GO) canopy reflectance model to provide maps of fractional crown cover (dimensionless), mean canopy height (m), and aboveground woody biomass (Mg ha �1 ) on a 250 m grid. Model adjustment was performed after dynamic injection of a background contribution predicted via the kernel weights of a bidirectional reflectance distribution function (BRDF) model. Accuracy was assessed with respect to similar maps obtained with data from the NASA Multiangle Imaging Spectroradiometer (MISR) and to contemporaneous US Forest Service (USFS) maps based partly on Forest Inventory and Analysis (FIA) data. MODIS and MISR retrievals of forest fractional cover and mean height both showed compatibility with the USFS maps, with MODIS mean absolute errors (MAE) of 0.09 and 8.4 m respectively, compared with MISR MAE of 0.10 and 2.2 m, respectively. The respective MAE for aboveground woody biomass was ~10 Mg ha �1 , the same as that from MISR, although the MODIS retrievals showed a much weaker correlation, noting that these statistics do not represent evaluation with respect to ground survey data. Good height retrieval accuracies with respect to averages from high resolution discrete return lidar data and matches between mean crown aspect ratio and mean crown radius maps and known vegetation type distributions both support the contention that the GO model results are not spurious when adjusted against MISR bidirectional reflectance factor data. These results highlight an alternative to empirical methods for the exploitation of moderate resolution remote sensing data in the mapping of woody plant canopies and assessment of woody biomass loss and recovery from disturbance in the southwestern United States and in parts of the world where similar environmental conditions prevail.
Loss of Oca2 disrupts the unfolded protein response and increases resistance to endoplasmic reticulum stress in melanocytes

Accumulation of proteins in the endoplasmic reticulum (ER) typically induces stress and initiates the unfolded protein response (UPR) to facilitate recovery. If homeostasis is not restored, apoptosis is induced. However, adaptation to chronic UPR activation can increase resistance to subsequent acute ER stress. We therefore investigated adaptive mechanisms in Oculocutaneous albinism type 2 (Oca2)-null melanocytes where UPR signaling is arrested despite continued tyrosinase accumulation leading to resistance to the chemical ER stressor thapsigargin. Although thapsigargin triggers UPR activation, instead of Perk-mediated phosphorylation of eIF2α, in Oca2-null melanocytes, eIF2α was rapidly dephosphorylated upon treatment. Dephosphorylation was mediated by the Gadd34-PP1α phosphatase complex. Gadd34-complex inhibition blocked eIF2α dephosphorylation and significantly increased Oca2-null melanocyte sensitivity to thapsigargin. Thus, Oca2-null melanocytes adapt to acute ER stress by disruption of pro-apoptotic Perk signaling, which promotes cell survival. This is the first study to demonstrate rapid eIF2α dephosphorylation as an adaptive mechanism to ER stress.
Platitudes and attitudes

In October 2002 I attended the Ninth Monterey Software Engineering workshop held in Venice, Italy. This year’s theme was titled “Radical Innovations of Software and Systems Engineering in the Future.” In preparing my talk for the workshop, I thought hard about what I could possibly say on this topic that would not sound stupid. I certainly thought it would be awfully presumptious of me to predict how people will or should be developing software in the future. More easily, I could imagine what the systems of tomorrow will look like and who will be developing them, though anything I would say would sound like platitudes. I could also state some strong opinions about what matters and what doesn’t in the process of software development. Stating such attitudes would at least provoke some discussion. Hence, what follows captures some of what I said at the workshop.
A survey comparison of career motivations of social work and business students

This survey provides valuable insight for social work educators into the goals and career intentions of working students who pursue master's degrees in social work, as compared to master's degrees in business. Social work graduate students were surveyed and compared to business graduate students in terms of their motivations for seeking advanced degrees and their expected career outcomes. Findings indicate that social work students were more motivated by a desire to gain knowledge or expertise in their service field, whereas business students differed in seeking greater career advancement and self-sufficiency. Social work implications for educational programs and practice are discussed.
HERG, a primary human ventricular target of the nonsedating antihistamine terfenadine

Background Administration of the antihistamine terfenadine (Seldane) to patients may result in acquired long QT syndrome and ventricular arrhythmias. One human cardiac target is Kv1.5, which expresses the ultrarapid outward K+ current (IKur) in atrium but may play only a minor role in ventricle. Another possible target is HERG, the human ether-a-go-go–related gene that expresses a delayed rectifier current (IKr) in human ventricle and produces hereditary long QT syndrome when defective. Methods and Results We therefore heterologously expressed Kv1.5 and HERG in Xenopus oocytes to compare the sensitivity of each to terfenadine. We found that HERG was 10 times more sensitive than Kv1.5 to terfenadine block. The apparent K d values for HERG and Kv1.5 currents were 350 nmol/L and 2.7 μmol/L, respectively. These K d values compare well with values reported for terfenadine block of IKr and IKur currents in human atrial myocytes. The K d value for HERG block is relevant to the toxicity of the antihistamine, since the clinical terfenadine concentrations in human plasma may reach the 100 nmol/L range. Conclusions Terfenadine carboxylate, the major metabolite of terfenadine, does not block either HERG or Kv1.5, which agrees with the hypothesis that the buildup of parent terfenadine is the likely explanation for its cardiotoxicity. We propose that the blocking of HERG by terfenadine explains the acquired long QT syndrome. HERG is likely to be the primary target for the known cardiotoxic effects of other, related antihistamines.
Intravascular ultrasound identification of stent entrapment in vivo with in vitro confirmation.

Objectives: One potential complication of stenting is “stent jail” due to placement of a stent across a side branch, which may impede additional interventions. Another form of stent entrapment may occur if the guidewire is accidentally withdrawn and then unknowingly passes through a stent loop during reentry with subsequent high pressure expansion. The purpose of this study was to evaluate this form of stent entrapment in vitro by intravascular ultrasound (IVUS). Methods A guidewire was passed through the end or middle diamonds of Palmaz-Schatz and Palmaz stents or the middle of Gianturco-Roubin stents. A 3.5 mm balloon was inflated over the guidewire through the various side holes of the stents. Results IVUS images presented three distinct patterns depending on the type of stent and position of balloon entry: 1) external compression and loss of wall continuity in the Palmaz-Schatz and Palmaz stents, 2) displacement of the side diamond across the lumen, and 3) external compression of the Gianturco-Roubin stent. The first and second patterns but not the third one were associated with impairment of lumen access. Conclusions Based upon this in vitro verification, IVUS imaging can be used to identify the presence of stent entrapment in vivo. Cathet Cardiovasc Diagn 40:40–45, 1997. © 1997 Wiley-Liss, Inc.
The mechanism of calcium-induced microtubule disassembly

Abstract We have examined the mechanism of calcium induced microtubule dissasembly by combined kinetic and steady state analysis. Our results indicate that calcium induces microtubule disassembly by binding directly to the wall of the microtubule and promoting dissociation of subunits from the ends.
Relational equilibrium in a social topology

The purpose of this discussion is to transform the implicit equilibrium assumption endemic to network analysis into an explicit instrument for such analysis. I propose a formal model that brings together Coleman's restriction of Walras’ general equilibrium model and recent developments in describing the “social topology” of a multiple network system of actors such that a class of relational equilibria is defined. The specific equilibrium expected in a system is a function of the previously existing stratification of actors in the system. Corresponding to multiple observed networks, the model generates multiple equilibrium networks. The structural analysis of the observed networks can therefore be repeated on the equilibrium networks so as to assess the extent to which the analysis would differ if the observed relations were actually in an equilibrium state. Numerical illustration is provided by an analysis of alternative relational equilibria in the system of elite experts in methodological and mathematic...
Four-nucleon transfer via the (6Li, d) reaction

Abstract The systematic behavior of the ( 6 Li, d) reaction on doubly even fp shell targets, as it has been observed in experiments at Rochester during the past years, is reviewed and an attempt is made to relate the results to the structure of the nuclei involved.
Surface generalizations: An alternative to alternations

Since the earliest days of generative grammar, there has existed a strong tendency to consider one argument structure construction in relation to a particular rough paraphrase. Initially this was a result of the emphasis on transformations that derived one pattern from another. While today there exist many non-derivational theories for which this motivation no longer exists, the traditional outlook has not completely lost its grip, as can be seen from continuing focus on partial or incomplete generalizations such as the ‘‘dative’’ construction or the ‘‘locative’’ alternation. This article argues that it is profitable to look beyond alternations and to consider each surface pattern on its own terms. Differences among instances of the same surface pattern are often most naturally attributed directly to the different verbs and arguments involved.
Computerized three-dimensional activation mapping study of spontaneous ventricular arrhythmias during acute myocardial ischemia in dogs: Evidence against macroreentrant mechanism

Abstract This study was undertaken to investigate the activation patterns of spontaneous ventricular arrhythmias during acute myocardial ischemia in dogs. In 14 open-chest dogs, the left anterior descending coronary artery was occluded for 2 hours. Three-dimensional activation maps were derived from 240 bipolar sites by insertion of 60 plunge needle electrodes into both ventricles and the septum. Global ventricular activation sequences were displayed in five planes in 10 dogs, whereas the high density regional activation maps of the anterior wall were displayed in four layers in 4 dogs. Three-dimensional activation maps of 95 sinus beats, 82 premature ventricular complexes (PVCs), and 210 beats of ventricular tachycardia (VT) were analyzed. Sinus beats had a uniform activation pattern with total ventricular activation times measuring 42 ± 4 ms and 67 ± 8 ms during baseline and ischemia, respectively ( P
Intraoperative Ultrasonography with a Cystoscope for the Biopsy of a Deep-seated Brain Lesion: Case Study

An intraoperative technique for deep brain biopsy is described. It features the use of an integrated surgical support system for the instruments and a rod that provides external topographical maintenance of the coordinates established ultrasonographically. A cystoscope, when supported mechanically by this system, permits multiple entries of the biopsy forceps to the lesion without further disturbance of the brain, as well as irrigation, coagulation, and visualization, if desired. When used in conjunction with real time intraoperative ultrasonography, the surgeon may view the entire procedure and be certain that the biopsy sample has been obtained from the lesion, major deep blood vessels have been avoided, and the biopsy site is stable after the procedure. The advantages of this technique include simplicity, low cost, accuracy, stability, and availability to every neurosurgeon in every hospital.
Added Bonus? The Relationship between California School Districts' Specialized Teacher Staffing Needs and the Use of Economic Incentive Policies.

In this paper, we explore the use and efficacy of fiscal incentive policies in California school districts. We ask whether districts with high need for teachers with English as a second language (ESL) or special education credentials are more likely to implement incentives targeting these teachers. We find mixed evidence that districts align their incentives with their staffing needs. We conclude by discussing possible rationales for our results.
HPLC-UV and LC-MS-MS Characterization of Silymarin in Milk Thistle Seeds and Corresponding Products

Abstract A HPLC analytical protocol for the separation of taxifolin, silychristin, silydianin, silybinin A, silybinin B, isosilybinin A, and isosilybinin B was developed. The gradient method used a combination of water and methanol as the eluent, and the separation was monitored at 290 nm. The authenticity of the reference compounds was correctly analyzed by liquid chromatography-mass spectrometry-mass spectrometry and by spiking HPLC experiments. The dihydroflavonol taxifolin and the flavanolignans silychristin, silydianin, and silybinin A and B were extracted from two milk thistle (Silybum marianum(L.) Gaertn.) seed batches using organic solvents, and subsequently quantified by the developed method. Both seed batches differed in their silydianin, silybinin A, and silybinin B contents. Taxifolin and the flavanolignans were also quantified in finished products, where the ratio of the silybinin compounds was similar in tested Brands A and B. Brand A was first extracted in a Soxhlet with ethanol. Under thes...
Characterization of the N-Acetyl-5-neuraminic Acid-binding Site of the Extracytoplasmic Solute Receptor (SiaP) of Nontypeable Haemophilus influenzae Strain 2019

Nontypeable Haemophilus influenzae is an opportunistic human pathogen causing otitis media in children and chronic bronchitis and pneumonia in patients with chronic obstructive pulmonary disease. The outer membrane of nontypeable H. influenzae is dominated by lipooligosaccharides (LOS), many of which incorporate sialic acid as a terminal nonreducing sugar. Sialic acid has been demonstrated to be an important factor in the survival of the bacteria within the host environment. H. influenzae is incapable of synthesizing sialic acid and is dependent on scavenging free sialic acid from the host environment. To achieve this, H. influenzae utilizes a tripartite ATP-independent periplasmic transporter. In this study, we characterize the binding site of the extracytoplasmic solute receptor (SiaP) from nontypeable H. influenzae strain 2019. A crystal structure of N-acetyl-5-neuraminic acid (Neu5Ac)-bound SiaP was determined to 1.4A resolution. Thermodynamic characterization of Neu5Ac binding shows this interaction is enthalpically driven with a substantial unfavorable contribution from entropy. This is expected because the binding of SiaP to Neu5Ac is mediated by numerous hydrogen bonds and has several buried water molecules. Point mutations targeting specific amino acids were introduced in the putative binding site. Complementation with the mutated siaP constructs resulted either in full, partial, or no complementation, depending on the role of specific residues. Mass spectrometry analysis of the O-deacylated LOS of the R127K point mutation confirmed the observation of reduced incorporation of Neu5Ac into the LOS. The decreased ability of H. influenzae to import sialic acid had negative effects on resistance to complement-mediated killing and viability of biofilms in vitro, confirming the importance of sialic acid transport to the bacterium.
The fredholm and volterra problems for stieltjies integral equations

The primary purpose of this paper is to study solutions to the integral equations, — denotes either the left Cauchy or Young integral, and g is quasi-continuous on [a, b]. Necessary and sufficient conditions for K to generate a compact operator on the quasi-continuous functions in each of these cases are given, and necessary and sufficient conditions for λ to be a regular value for the integral operators are given in the case that the operators are compact. The problem of approximating solutions to the integral equations is considered. These results are obtained as special cases of solutions to a type of abstract integral equation on an abstract function space
Frequency and predictors of de novo hepatocellular carcinoma in patients awaiting orthotopic liver transplantation during the model for end-stage liver disease era.

In the current system of allocation, patients awaiting orthotopic liver transplantation (OLT) remain at risk of developing de novo hepatocellular carcinoma (HCC) and removal from the waiting list. Using the United Network for Organ Sharing database, we calculated the rate and identified predictors of de novo HCC in patients listed for OLT between February 2002 and December 2004. Among 8566 patients, 1167 (13.6%) developed de novo HCC. Predictors of increased odds of de novo HCC were older age, male gender, Asian race, other race, hepatitis C, and hepatitis B. A sensitivity analysis of 2067 patients waiting at least 6 months found that 16.2% developed de novo HCC. Older age [odds ratio (OR) 1.05; 95% confidence interval (CI) 1.03, 1.07], male gender (OR 2.01; 95% CI 1.49, 2.71), Asian race (OR 2.39; 95% CI 1.20, 4.76), other race (OR 1.94; 95% CI 1.40, 2.68), hepatitis C (OR 2.36; 95% CI 1.76, 3.16), and hepatitis B (OR 1.96; 95% CI 1.19, 3.23) remained predictors of increased odds of de novo HCC, and alcoholic liver disease (OR 1.40; 95% CI 1.06, 1.86) emerged as a predictor of increased odds of de novo HCC. A significant proportion of patients listed for OLT develop de novo HCC. Identifying predictors of HCC in these patients may facilitate timely HCC screening and diagnosis. Liver Transpl 14:228–234, 2008. © 2008 AASLD.
Ganglioside-induced adherence of botulinum and tetanus neurotoxins to adducin

Preincubation of botulinum neurotoxin serotype A, B, or E with ganglioside GT1b was previously found to enhance adherence of botulinum neurotoxin to synapsin I and an approximately 116-kDa bovine brain synaptosomal protein; in contrast, adherence to these two proteins by tetanus neurotoxin required preincubation with GT1b. We have now found that preincubation of the neurotoxins with ganglioside GD3 enhances their adherence to the approximately 116-kDa protein more than that with GT1b. A purified preparation of the water-soluble approximately 116-kDa protein was obtained from bovine brain synaptosomes by preparative column sodium dodecyl sulfate-polyacrylamide gel electrophoresis and two-dimensional gel electrophoresis. N-Terminal amino acid sequences were obtained for two tryptic fragments of the approximately 116-kDa protein. These sequences matched with the data bank sequences for beta-adducin, a cytoskeletal protein. The carboxy-terminal tail region of adducin, but not the head region, was adhered to by the neurotoxins. Adherence of the neurotoxin to adducin and synapsin I may facilitate presentation of the neurotoxin to its specific substrate(s).
Davis' Concepts of Slope Development viewed in the Light of Recent Quantitative Investigations

(1950). Davis' Concepts of Slope Development viewed in the Light of Recent Quantitative Investigations. Annals of the Association of American Geographers: Vol. 40, No. 3, pp. 209-213.
Assessing food intolerance: don’t lose control

See article on page632 In 1970, Cuatrecasas et al showed that healthy individuals could have an isolated deficiency of intestinal lactase.1 Shortly thereafter, it was shown that a large fraction of the world’s adult population became lactase deficient2 owing to a genetically programmed reduction in lactase activity,3 a state now known as lactase non-persistence. Initial studies4 showed that many lactase non-persistent subjects had easily identifiable symptoms after ingestion of a challenge dose of 50 g lactose (the equivalent of one quart of milk). When early, unblinded studies5 6 suggested that physiological quantities of milk (one cup or less) could induce appreciable symptoms, lactose intolerance became a favoured explanation for a variety of what otherwise would have been considered to be functional abdominal symptoms. The widespread dissemination of this information in lay publications has led a sizable fraction of the population of the United States to believe that lactose, in trivial quantities, is the cause of a wide array of abdominal symptoms. One of the prevailing ideas concerning lactose malabsorbers was that continued ingestion of this disaccharide …
Start Where They Are: Geometry as an Introduction to Proof

(2000). Start Where They Are: Geometry as an Introduction to Proof. The American Mathematical Monthly: Vol. 107, No. 1, pp. 44-52.
The debut of a rational treatment for an inherited neuropathy

Hereditary neuropathies are common neurological conditions characterized by progressive loss of motor and/or sensory function. There are no effective treatments. Among the many causes of hereditary neuropathies are dominant mutations in serine palmitoyltransferase, long chain base subunit 1 (SPTLC1), which cause hereditary sensory and autonomic neuropathy type 1 (HSAN1). By incorporating l-alanine in place of l-serine, the mutant HSAN1–associated serine palmitoyltransferase generates deoxysphingolipids, which are thought to be neurotoxic. In this issue of the JCI, Garofalo and colleagues report that oral l-serine reverses the accumulation of deoxysphingolipids in humans with HSAN1 and in a transgenic mouse model. As oral l-serine reduces the severity of neuropathy in the mouse model of HSAN1, these data suggest a rational candidate therapy for this devastating condition.
The power cost of over-designing codes

In “modern” coding theory, the goal of code-design often boils down to maximizing the code girth because from a traditional transmit-power perspective, larger girths ensure better performance. In this paper, we provide an experimental example showing that maximizing code girth can hurt: codes with larger girth can consume significantly larger decoding power. This is because larger girths require increased length of decoder interconnects. Concretely, we show that for (3,4)-regular LDPC codes of girth 6 and 8 decoded using Gallager-A decoding algorithm, the decoders for girth 8 codes can consume up to 36% more power than those for girth 6 codes at high decoding throughputs. Existing results in theoretical literature suggest that this effect will be greatly exaggerated at larger girths and degrees.
Determinants of Duration and Mean Rate of Ventricular Ejection

The independent influences of stroke volume, heart rate, aortic pressure, hypothermia, sympathomimetic amines, metered mitral and aortic valvular regurgitation, and alterations in myocardial contractility on the duration and mean rate of ventricular ejection and filling were studied. These observations were made in a metabolically supported, isolated heart preparation with performance characteristics comparable to the non-isolated heart.
Outreach to diversify clinical trial participation: A randomized recruitment study

Background/AimsRacial and ethnic minorities remain underrepresented in clinical research, yet few recruitment strategies have been rigorously evaluated.MethodsWe experimentally tested whether targeted recruitment letters acknowledging diabetes health disparities and health risks specific to recipients’ racial/ethnic group improved two metrics of trial participation: willingness to be screened and enrollment. This experiment was efficiently nested within a randomized clinical trial examining a preventive lifestyle intervention among women at high risk for diabetes. Pregnant women with gestational diabetes or impaired glucose tolerance (N = 445) were randomized to receive a targeted recruitment letter with health risk information specific to their racial/ethnic group (n = 216), or a standard letter with risk information for the general population (n = 229). All letters were bilingual in English and Spanish.ResultsThe targeted as compared to the standard letter did not improve screening or enrollment rates o...
Improving Normal Tissue Complication Probability Models: The Need to Adopt a "Data-Pooling" Culture

Clinical studies of the dependence of normal tissue response on dose-volume factors are often confusingly inconsistent, as the QUANTEC reviews demonstrate. A key opportunity to accelerate progress is to begin storing high-quality datasets in repositories. Using available technology, multiple repositories could be conveniently queried, without divulging protected health information, to identify relevant sources of data for further analysis. After obtaining institutional approvals, data could then be pooled, greatly enhancing the capability to construct predictive models that are more widely applicable and better powered to accurately identify key predictive factors (whether dosimetric, image-based, clinical, socioeconomic, or biological). Data pooling has already been carried out effectively in a few normal tissue complication probability studies and should become a common strategy.
Enzymic estimation of D-malate and other D-2-hydroxy acids.

Abstract Methods for the large-scale preparation of partially purified rabbit kidney d -2-hydroxyacid oxidoreductase and the use of this enzyme in a sensitive optically specific assay for d -malate and d -lactate have been presented.
The structure of high-angle grain boundaries

Abstract A coincidence model of high-angle grain boundaries can be extended to include deviations from coincidence. The generalised boundary has a terraced structure, corresponding to the densely packed planes in the coincidence lattice, and a superimposed dislocation network, corresponding to a sub-boundary in the coincidence lattice. This model is a natural extension of previous dislocation models and models based on coincidence relationships. The model explains many of the observed properties of grain boundaries and should have wide validity for the cubic system.
Buddy Esquire and the early hip hop flyer

Between 1978 and 1984 Buddy Esquire designed over 300 hip hop flyers. His career coincided with the first flourishing of the Bronx scene, when hip hop shifted from a community-based event to a full-blown commercial phenomenon. This paper analyses Buddy Esquire's flyer design style, supported by a discussion with the flyer artist. The analysis demonstrates that Esquire's ‘neo-deco’ style communicates the aspiration of live hip hop to classiness by suppressing overt graffiti elements, by alluding to the nightclub culture of disco and by using the Art Deco stylings of the Jazz Age as a signifier of sophistication. The paper then moves beyond an interpretation of the flyers, searching for reflections of Buddy Esquire's aesthetic in early hip hop culture. Finally, it proposes that Buddy Esquire's flyers challenge assumptions in current hip hop scholarship regarding early hip hop's aesthetic relationship to the past (particularly the early 20th century) and its self-documenting impulse.
Estrogen, estrogen treatment and the post-reproductive woman's brain

From early embryonic life to death, estrogen is a primary regulator of brain neurogenesis and cell number, synaptogenesis and synaptolysis, multiple cognitive and autonomic functions, vascular function, immune responses and defense measures against brain lesions and dystrophy. Although recent attention has focused on the roles of estrogen during the climacteric, knowing estrogen's role in brain development and reproductive function is necessary to understand what happens when this powerful influence is removed during the climacteric. This review will therefore address the full picture, with stress on the later-life role of estrogen in the brain.
Varicella zoster virus—a different kind of herpesvirus latency?

Abstract Clinically, varicella zoster virus (VZV) latency and reactivation are quite different from herpes simplex virus (HSV) latency and reactivation. Recent work with human dorsal root ganglia, with animal models of VZV infection and with cell cultures infected in vitro with VZV suggests that, at the molecular level, there are also substantial differences between these two genetically similar viruses. VZV appears able to establish ganglionic latency in non-neuronal cells and to express several lytic cycle viral genes while latent; these genes seem to represent very early events in viral multiplication. Immune responses to VZV may play a role in maintaining the latent state and certainly appear responsible for prevention of clinically apparent reactivation.
Using Piecewise Polynomials to Model Open-Circuit Potential Data

Curve fitting is commonly used to determine a mathematical expression for sets of experimental data. While there are many instances when theory dictates a linear, quadratic, or other simple mathematical form for a relationship, there are often times when the theoretical form is either unknown or too unwieldy to be used effectively. A common example is the open-circuit-potential relationship of a Li-ion battery. One may use empirical correlations such as high-order polynomials (HOP) or various types of splines which are piecewise polynomials of low order. Despite their simplicity, HOPs are often undesirable given their numerical instability as well as their poor extrapolation performance. Certain splines generally produce acceptably smooth curves but use an unacceptably large number of fitting parameters. A method is presented for construction of continuous and smooth piecewise polynomials. Using significantly fewer polynomial segments than experimental data points, the number of parameters required to develop the calibration curves of a Li-ion battery is substantially reduced from that of splines while maintaining a similar level of fit quality. Mixed-integer programming techniques are employed to ensure that the knot (transition point) placement is optimal.
Learning Multiplication The Easy Way

In this article, the author presents an innovative approach to teaching multiplication facts for children in middle school or younger. After introducing the dangers of some contradictions that persist, relating a brief summary of related research and guidelines regarding math facts and their relation to strategic approaches to more complex math, including problem solving, the author provides an in-depth discussion of the process of learning multiplication tables. The author presents a method for teaching children to learn these facts by rote without the tediousness of that technique. Providing the answers encourages automatic learning easily without testing. Remarkable results with one class of eighth-grade students support the benefit of this innovative method.