cssi/SciSciGPT-SciSciNet huggingface dataset:
A Change in Specificity of Chymotrypsin Caused by Chemical Modification of Methionine Residues

The specificity patterns of chymotrypsins in which the methionine residues have been converted to the sulfoxide have been examined relative to the native enzyme. When the surface methionine residue 3 residues away from the active serine is oxidized, the specificity pattern is quite similar to the native enzyme as judged by the relative rates of hydrolysis of ester and peptide substrates. When both methionine residues are oxidized to the sulfoxide, however, notable changes of the ratios occur. For example, the acetyltyrosinamide activity becomes undetectable, decreased by a factor of over 400, whereas the acetyltyrosine ethyl ester activity decreases by a factor of 4. The change in specificity is not related in a simple way either to a chemical property such as carbon-nitrogen versus the carbon-oxygen bond nor to the size of the substrate. Moreover, the binding properties for many substrates and all-or-none assay are changed very little. A plausible explanation for the observations is that the oxidation of the interior methionine residue does not change the basic catalytic power of the enzyme but does cause subtle changes in the relationship between substrate and enzyme which affects its specificity.
Characterization of the Serum High Density Lipoproteins and Apolipoproteins of Pink Salmon

Abstract High density lipoproteins (HDL) were isolated by centrifugation from the serum of salmon (Oncorhynchus gorbuscha) captured just before spawning. There were no detectable low density lipoproteins in their serum. Analytical ultracentrifugation of the lipoprotein fraction yielded only one band with a hydrated density of 1.103 g per ml and a peak F1.20 rate of 3.21 S. If the molecule is spherical, it would have minimum molecular weight of 180,000 and an average diameter of 80 A. The agarose gel electrophoresis pattern had one major and one minor band with the approximate mobility of human α-lipoprotein. The lipid class composition was very similar to that reported for human HDL. The phospholipids were mainly phosphatidylcholine (80%), its lysoderivative, and sphingomyelin. The major fatty acids were 16:0, 18:0, 18:1 (n-9), 20:5 (n-3), and 22:6 (n-3). Lipids accounted for 60% of the mass of the molecule. Disc electrophoresis in polyacrylamide gels (in 8 m urea at pH 8.6) produced a pattern with two major and several minor bands for both the intact lipoproteins and the lipid-free protein moiety. The over-all pattern was very similar to that of human HDL. The apoproteins from the salmon HDL were eluted from diethylaminoethylcellulose columns under conditions similar to those used for elution of apoproteins from human HDL; they also gave similar elution patterns. Their circular dichroism spectra resembled those of the corresponding human apolipoproteins. Despite all of these physical similarities, there were distinct and major differences between the amino acid compositions of salmon apoproteins and their human counterparts. These data suggest that general physical properties of the HDL are not specifically dependent on the total amino acid composition of the molecule but rather on its general secondary or tertiary structure and these same features must govern the binding of lipids to proteins in soluble lipoproteins.
Build High-Performing Military Nurse Leaders Through Coaching, Sponsorship, and Engagement

The healthcare environment is constantly evolving, and with economic pressures to reduce costs, it is changing at a rapid rate. The Army War College depicts this environment as volatile, uncertain, complex, and ambiguous. 1 Strategic nurse leaders must be able to embrace the rapidly changing environment, be visionary, innovative, adaptive, and learn effective and efficient strategies to minimize risk and maximize opportunities. The Institute of Medicine's Future of Nursing 2010 reported the need for strong transformational nurse leaders across the country who will lead system-wide campaigns of healthcare transformation. 2
Electroweak bosons in Pb+Pb and p+Pb collisions

Electroweak boson (W, Z, ) measurements in Pb+Pb collisions at p sNN = 2:76 TeV and in p+Pb collisions at p sNN = 5:02 TeV are presented with the ATLAS detector at the LHC. In Pb+Pb, electroweak boson yields are shown to be independent of centrality. Di erential measurements in absolute pseudorapidity are used to investigate nuclear e ects to the free-proton parton distribution function (PDF). The distributions lack the experimental precision to unambiguously identify the presence of nuclear modifications. In p+Pb, the Z boson cross section is measured as a function of center-of-mass rapidity y Z and the momentum fraction of the lead-going parton (Bjorken xPb). The distributions are asymmetric and model predictions underestimate the data at large xPb. The overall shape is best described by including nuclear e ects. The di erential cross section is also measured in di erent centrality classes and shows evidence of spatially-dependent nuclear PDFs. The Z boson production yields are measured as a function of the mean number of participants using Glauber and Glauber-Gribov color fluctuation models. Binary scaling of the yields is observed utilizing the standard Glauber model after applying a centrality-bias correction.
Bacillithiol, a new role in buffering intracellular zinc

Summary Zinc is a catalytic or structural cofactor of numerous proteins but can also be toxic if cells accumulate too much of this essential metal. Therefore, mechanisms of zinc homeostasis are needed to maintain a low but adequate amount of free zinc so that newly translated zinc-dependent proteins can bind their cofactor without confounding issues of toxicity. These mechanisms include the regulation of uptake and efflux transporters and buffering of the free metal concentration by low-molecular-weight ligands in the cytosol. While many of the transporters involved in zinc homeostasis have been discovered in recent years, the molecules that buffer zinc have remained largely a mystery. In the new report highlighted by this commentary, Ma et al. (2014) provide convincing evidence that bacillithiol, the major low-molecular-weight thiol compound in Bacillus subtilis, serves as an important zinc buffer in those cells. Their discovery provides an important piece to the puzzle of how zinc buffering occurs in a large number of microbes and provides new clues about the role and relative importance of zinc buffering in all organisms.
Internationalization and the Cosmopolitical University

This article discusses some of the issues that surround the internationalization of higher education as a way to open discussion about the construction of an alternative cosmopolitical vision of the university, necessary if the university is to fulfill any historic tasks concerning the creation of globally aware citizens. The authors indicate that economic and technological globalization has resulted not only in the growth of international education, but also in the increasing significance of transnational spaces. In this environment, the internationalization of higher education refers to strategies to attract students and also to specific patterns of movement. The authors maintain that the neoliberal metanarrative informing strategies of internationalization not only ignores the complexity of those patterns of interaction, connectedness and movement, but also implies modes of insertion of higher education into transnational spaces, as receptors or senders of certain flows. The way in which students' move...
Effect of Long Generation Times on Growth of Bacteroides thetaiotaomicron in Carbohydrate-Limited Continuous Culture

We investigated the ability of Bacteroides thetaiotaomicron, an obligate anaerobe from human colonic microflora, to grow in a carbohydrate-limited continuous culture at generation times ranging from 3.5 to 28 h per division. Four carbohydrates were tested: glucose, N-acetylglucosamine, glucuronic acid, and glucosamine. At a generation time of 3.5 h per division, the growth yields for bacteria growing on glucose, N-acetylglucosamine, and glucuronic acid were 76, 68, and 50 g of cells (dry weight) per mol of substrate, respectively. Growth yields at 28 h per division were 61, 52, and 37 g/mol of substrate, respectively. When glucosamine was the carbohydrate source, a stable population of bacteria was attainable only at generation times longer than 12 h per division. Growth yields at 15 and 32 h per division were 11 and 33 g/mol of substrate, respectively. There was no significant variation with increasing generation times in the specific activities of selected glycolytic enzymes, of disaccharidases such as alpha- and beta-glucosidases and alpha- and beta-galactosidases, or of the polysaccharidase chondroitin sulfate lyase. By contrast, the pattern of fermentation products varied with both the generation time and the carbon source. At a generation time of 3.5 h per division, the main products from the fermentation of glucose were acetate and succinate, with a trace of propionate. At 28 h per division, propionate concentrations were higher and succinate concentrations were lower than at 3.5 h per division. The products from the fermentation of glucosamine were the same as those from glucose fermentation. However, when N-acetylglucosamine was fermented, the concentration of acetate was much higher at all generation times than when glucose was the carbon source. When glucuronic acid was the carbon source, acetate was the main fermentation product, and only traces of propionate and succinate were detected. Another characteristic that varied with the growth rate was the ability of B. thetaiotaomicron to produce the inducible enzyme alpha-glucosidase when exposed to maltose. The ability of the organism to produce this enzyme declined with increasing generation times.
Ketosis Causing Spurious Elevation of SGOT Values

In two patients, spurious enhancements of SGOT on SMA 12/60 determination caused erroneous diagnoses of liver disease, which could have led to potentially hazardous diagnostic measures. Such errors can be avoided by an ultraviolet spectroscopic check of suspect SGOT values.
Antenna-coupled microwave kinetic inductance detectors

Abstract We report on the development of Microwave Kinetic Inductance Detectors (MKIDs) coupled to planar antennas for millimeter/submillimeter wavelengths. The MKID is a relatively new type of superconducting photon detector which is applicable from millimeter-wave frequencies to X-rays. Photons are absorbed in a superconductor, producing quasiparticle excitations, which change the surface reactance (kinetic inductance) of the superconductor. The changes in kinetic inductance are monitored using microwave high-Q thin-film superconducting resonators. Because the MKID is particularly amenable to frequency-domain multiplexing, with likely detector multiplexing factors of ∼ 10 3 or more per cryogenic amplifier, these detectors are well suited for use in large arrays. We have fabricated MKIDs coupled to submillimeter slot-array antennas using microstrip lines and have detected power from a thermal radiation source. We discuss the potential of antenna-coupled MKID arrays for ground and space-based millimeter/submillimeter imaging.
Catalytic Propene Polymerization: Determination of Propagation, Termination, and Epimerization Kinetics by Direct NMR Observation of the (EBI)Zr(MeB(C6F5)3)propenyl Catalyst Species

Treatment of (EBI)ZrMe2 with B(C6F5)3 and 100 equiv of 1-hexene in toluene-d8 at −40 °C for 1 h, followed by addition of >5 equiv of propene, generates a living polypropene catalyst (3) with a polyhexene “tail”. Upon further addition of propene, speciation of the catalyst and propagation kinetics are measured directly by NMR, yielding a propagation rate law that is first order in [propene] and [living catalyst] with a rate constant of 2.6 M-1 s-1 at −40 °C and the activation parameters ΔH⧧ = 3.4(0.2) kcal/mol and ΔS⧧ = −42(2) cal/(mol K). In the absence of propene, elimination of vinylidene-terminated polymer is observed with a first-order rate constant of 3.3 (0.5) × 10-5 s-1 at −40 °C and ΔH⧧ = 12.9(1.4) kcal/mol and ΔS⧧ = −23(5) cal/(mol K). Use of 1-13C-propene and 1,1-2H-2,3-13C-propene and 1H, 19F, and 13C NMR spectroscopy provide rigorous characterization of the living catalyst and enable the first direct observation of both 1,3-isomerization and chain-end epimerization processes at a metallocene c...
Cardiovascular Abnormalities in Transgenic Mice With Reduced Brown Fat An Animal Model of Human Obesity

Background—A new model of murine obesity has recently been developed through transgenic ablation of brown adipose tissue that manifests typical metabolic complications of obesity, including insulin resistance and non–insulin-dependent diabetes mellitus. The cardiovascular phenotype has not been defined. Methods and Results—Transthoracic echocardiography, aortic catheterization, isolated whole-heart studies, and morphometric histology defined cardiac structure and function in 30 transgenic mice with reduced brown fat and 30 matched wild-type controls. Obesity was indicated by a 77% increase in body weight and was accompanied by elevated systemic pressures (mean aortic blood pressure 85±1 versus 66±2 mm Hg; P<0.01), left ventricular dilation and hypertrophy (mass/body weight 4.0±0.2 versus 2.7±0.3 mg/g; P<0.01), and high cardiac output (cardiac index 3.2±0.4 versus 2.4±0.1 mL · kg−1 · min−1; P<0.01). Baseline functional parameters assessed in vitro were not different, but after imposition of zero-flow ische...
"Blow" of the Pilot Whale

A captive pilot whale emptied as much as 88 percent of lung gas passively, without the aid of expiratory muscles. Level or decreasing pressures in the esophagus during expiration, and in the blowhole at the onset of expiration, revealed the driving force of expiration to be solely elastic recoil. Active muscular reexpansion of the lungs ensued immediately. Expiration and inspiration were completed in about I second.
Exciton/biexciton energies in rectangular GaAs/AlxGa1-xAs quantum-well wires including finite Al-graded band offsets with application to third-order optical susceptibilities.

Exciton and biexciton binding energies and wave functions are calculated with a three-parameter variational model in an effective-mass approximation for a rectangular GaAs quantum-well wire surrounded by an ${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As cladding. Moreover, the Al interdiffusion into the wire and the finite band offsets between the wire and the cladding have been included. For the range of dimensions studied, the inclusion of the Al interdiffusion had a pronounced effect on the binding energies when compared to those obtained from the infinite barrier model [Frank L. Madarasz, Frank Szmulowicz, F. Kenneth Hopkins, and Donald L. Dorsey, Phys. Rev. B 49, 13 528 (1994); J. Appl. Phys. 75, 639 (1994); Phys. Rev B 51, 4633 (1995)]. Using the results of the exciton and biexciton calculation, we calculate the third-order nonlinear optical susceptibility as a function of pump-probe frequencies in a small range about the exciton absorption resonance. We have found, depending upon wire dimensions, broadening parameter(s) size, and the amount of pump detuning, values of the imaginary parts of the susceptibilities to be on the order of -${10}^{\mathrm{\ensuremath{-}}1}$ esu and a fairly large off-resonance absorption due to biexciton formation.
Fluorescent staining of κ opioid receptors using naltrexamine derivatives and phycoerythrin

An immunofluorescent technique that is more sensitive than radioligand binding was developed in order to detect opioid receptors expressed on leukocytes. The current study was designed to optimize the method for fluorescently labeling kappa opioid receptors. For these experiments, the opioid antagonist naltrexamine was conjugated to either fluorescein (FITC-NTXamine) or biotin (biotin-NTXamine). One-step, two-step, and three-step protocols were compared to determine which procedure resulted in optimal staining of the kappa opioid receptor expressed on intact, unfixed R1E/TL8x.1.OUAr.1(R1EGO) cells, a thymoma known to express kappa opioid receptors. The one-step method involved incubating cells with FITC-NTXamine, and the fluorescein intensity was measured by flow cytometry. In the two-step method, cells were incubated with biotin-NTXamine, followed by extravidin-conjugated phycoerythrin, and the phycoerythrin fluorescence was measured. Finally, in the three-step protocol, cells were incubated with FITC-NTXamine, followed by biotin-conjugated anti-fluorescein IgG, then extravidin-phycoerythrin. The one-step protocol stained the cells, but the signal was not diminished in the presence of opioid competitors. The two-step approach did not stain cells significantly above background levels. Only the three-step approach yielded staining that was displaced by the kappa-selective antagonist nor-binaltorphimine. Thus, the addition of a secondary biotinylated antibody, resulting in the amplification of binding, which was detected using phycoerythrin as a fluorophore, was required to detect low levels of opioid receptor expression on leukocytes.
Anti-receptor antibody and resistance to graft- versus -host disease

GRAFT-versus-host (GvH) disease is a complex syndrome initiated by the reaction of donor lymphoid cells against histocompatibility antigens of the host. Although newborn hybrid animals injected with parental-strain lymphoid cells develop fatal GvH disease, adult hybrid animals receiving weight-adjusted doses of such cells develop no clinically evident disease1,2. This resistance to GvH disease is agedependent and radiosensitive; resistance develops at 3–4 weeks of age and is abolished by sublethal total-body irradiation1. Immunologically specific suppression of GvH reactions has been achieved by immunisation of F1 hybrid host to produce antibody reactive with receptors on donor lymphoid cells for host antigens3,4.
Re-examination of the Effect of Aprotic Solvents Upon the Fundamental Vibrational Peak of the Carbonyl Group in 1,1,3,3-Tetramethylurea

The 1650 cm-1 IR absorption band for the fundamental vibration of the C = O group in tetramethylurea (TMU) exhibits a substantial solvent-induced shift in polar and nonpolar aprotic solvents at 298 K. Earlier studies have rationalized the upsilon max (C = O) shifts in terms max of the empirical Gutmann acceptor numbers (ANs) for the solvents or the Kirkwood parameter in dielectric permittivity (epsilon). With a larger set of test data, other reaction field models are now compared which incorporate alternative continuum functions as elements in the formulation of an SCRF-MO perturbation description for the aprotic solvent effect upon the upsilon max (C = O) of TMU. The magnitude max of the band shift appears to depend on both the solvent dipolarity and solvent polarizability, with the first being the dominant factor in the more reliable model.
Analyses of the fiber push-out test

Abstract A two-dimensional model of the fiber push-out test is considered. Two distinct methods of analysis are independently employed in solving the problem, and their accuracy is indicated by the virtual coincidence of the results. Interfacial debonding is assumed to be characterized by a cohesive zone model, and subsequent slippage obeys a Coulomb friction law. We have found that the results depart from those of the more commonly employed fracture-mechanics approach, if the cohesive zone size is of the order of the fiber diameter. The accuracy of various approximate analyses is discussed.
Universal access to information

In 2003, the world produced about 800MB of information for each man, woman, and child on earth [2]. Much of this information, such as supermarket scanner data and the like, is pretty dull. But some of it, such as the material contained in books, magazines, newspapers, movies, music, and family photos, is potentially of great interest to people.
Anoxic tolerances of three species of salamander larvae.

1. 1. Survival times of Siren intermedia, Ambystoma maculatum and A. opacum larvae in one or two developmental stages were determined under nitrogen anoxia. Effects of temperature and constant and cyclic acclimation were determined. 2. 2. LT (lethal time = time at which a given percentage of animals died at 0 ppm) values varied ontogenetically and interspecifically. 3. 3. A 10°C decrease in test temperature increased the LT values as follows: Siren, 200 per cent; A. maculatum, 100–200 per cent; and A. opacum, 100 per cent. 4. 4. A 10°C increase in test temperature decreased the LT values by 75–80 per cent in A. opacum. 5. 5. Acclimation to continually low (1·8 ppm) oxygen caused A. opacum to be significantly more tolerant than high oxygen (8·7 ppm) controls. 6. 6. Cyclic acclimation caused A. maculatum to be significantly more tolerant than continuously high oxygen controls.
Data Processing Assessment For The Lunar Geoscience Observer Imaging Spectrometer

On the Lunar Geoscience Observer project, a Visible and Infrared Mapping Spectrometer instrument has been proposed. This instrument will have science data input rates in the hundreds of kilobits per second (kbps) and an average telemetry output data rate of 4 kbps. Techniques that can be used to reduce the throughput of the instrument are editing, summing and averaging, data compression, data preprocessing, pattern recognition and snapshot data taking. Due to instrument limitations in the buffer memory size and processing speeds, a careful selection of the available techniques must be made.
Conceptualizing health consequences of Hurricane Katrina from the perspective of socioeconomic status decline.

Objective: The long-term health impact of acute unemployment and socioeconomic resource deficit has not been shown to be unique from the effects of stable socioeconomic status (SES) and serious life circumstances, such as trauma. This study examined associations between these acute socioeconomic declines and health of hurricane survivors, independent of prehurricane SES and hurricane trauma. Method: Participants were 215 African American adults (60% female, mean age = 39 years) living in the Greater New Orleans area at the time of Hurricane Katrina and survey 4 years later. The survey included prehurricane SES measures (i.e., education and neighborhood poverty level); acute unemployment and deficits in access to SES resources following Hurricane Katrina; and posthurricane health events (i.e., cardiometabolic events, chronic pain, posttraumatic stress disorder [PTSD], and major depressive disorder [MDD]). Results: Acute unemployment was associated with odds of experiencing a cardiometabolic event (odds ratio [OR] = 5.65, p Language: en
A study on KdV and Gardner equations with time-dependent coefficients and forcing terms

Abstract In this work we study the KdV equation and the Gardner equation with time-dependent coefficients and forcing term for each equation. A generalized wave transformation is used to convert each equation to a homogeneous equation. The soliton ansatz will be applied to the homogeneous equations to obtain soliton solutions.
Morphologic differentiation of mouse neuroblastoma cells induced in vitro by dibutyryl adenosine 3':5'-cyclic monophosphate.

The mechanism of mammalian neural differentiation is still obscure; but the availability of mouse neuroblastoma cells in vitro provides an opportunity to study some possible inducers of differentiation and this may help to elucidate the events involved at the molecular level. We have reported1 that X-irradiation of mouse neuroblastoma cells in vitro induces the formation of axons. The differentiated cells seem to undergo maturation: the soma and nucleus increase in size and the cytoplasm becomes granular. Here we report that N6O2 dibutyryl adenosine 3′:5′-cyclic monophosphate (dibutyryl cyclic AMP) induces axon formation in mouse neuroblastoma cells in vitro.
Carbon dioxide in the Paleozoic atmosphere: Evidence from carbon-isotope compositions of pedogenic carbonate

Stable carbon-isotope compositions of pedogenic carbonate occurring in three clay-rich vertic paleosols within Paleozoic red-bed successions in central Pennsylvania provide a record of past pedogenic environments and can be used to estimate CO{sub 2} pressure (P{sub CO{sub 2}}) of the Paleozoic atmosphere. The {delta}{sup 13}C values of carbonate nodules from paleosols in the deltaic lower Bloomsburg Formation (Upper Silurian) reflect the contribution of carbon from marine groundwater or fossils, coupled with low biological activity. The {delta}{sup 13}C values of carbonate rhizocretions from stratigraphically high paleosols in the Bloomsburg Formation, and in the alluvial Catskill (Upper Devonian) and Mauch Chunk (Upper Mississippian) Formations, suggest an extensive C{sub 3} flora and significant contribution of atmospheric CO{sub 2}. Paleozoic atmospheric CO{sub 2} levels inferred from {delta}{sup 13}C of pedogenic carbonate are significantly higher than present levels.
Fast communication: Statistical image modeling in the contourlet domain using contextual hidden Markov models

In this paper, a contourlet contextual hidden Markov model (C-CHMM) is established for modeling contourlet images by adapting a previous CHMM for wavelet images (W-CHMM). A mutual information based context design procedure is presented, through which a new context has been constructed. The C-CHMM is tested in a denoising application with promising results, which verifies its effectiveness. This new model is demonstrated to be a better model for contourlet images than the state of the art contourlet hidden Markov tree model. As a general image model, it also shows more potential than the baseline W-CHMM.
Electrogenic proton transport in epithelial membranes.

Certain polar epithelial cells have strong transport capacities for protons and can be examinedin vitro as part of an intact epithelial preparation. Recent studies in the isolated turtle bladder and other tight urinary epithelia indicate that the apical membranes of the carbonic anhydrase-containing cell population of these tissues contain an electrogenic proton pump which has the characteristics of a proton-translocating ATPase. The translocation of protons is tightly coupled to the energy of ATP hydrolysis. Since the pump translocates protons without coupling to the movement of other ions, it may be regarded as an “ideal” electrogenic pump. The apparent simplicity of the functional properties has led to extensive studies of the characteristics of this pump and of the cellular organization of the secondary acid-base flows in the turtle bladder. Over a rather wide range of electrochemical potential gradients for protons ( $$\Delta \tilde \mu _H $$ ) across the epithelium, the rate of H+ transport is nearly linear with $$\Delta \tilde \mu _H $$ . The formalisms of equivalent circuit analysis and nonequilibrium thermodynamics have been useful in describing the behavior of the pump, but these approaches have obvious limitations. We have attempted to overcome some of these limitations by developing a more detailed set of assumptions about each of the transport steps across the pump complex and to formulate a working model for proton transport in the turtle bladder that can account for several otherwise unexplained experimental results. The model suggests that the real pump is neither a simple electromotive force nor a constant current source. Depending on the conditions, it may behave as one or the other.
Effect of chronic central endothelin-1 on hemodynamics and plasma vasopressin in conscious rats.

Abstract Objectives: These studies were designed to test whether chronic central administration of endothelin-1 induces changes in systemic hemodynamics and plasma vasopressin similar to those observed with acute microinjections of endothelin-1. Methods: Sprague Dawley rats underwent sham denervation or sinoaortic denervation. Three days later, baseline mean arterial blood pressure, heart rate, and vasopressin were assessed in conscious rats. Then, a cannula was stereotaxically inserted into the lateral ventricle and attached to an osmotic minipump that delivered one of the following: (i) artificial cerebrospinal fluid; (ii) endothelin-1, 10 pmol/hour; (iii) BQ-123, 400 pmol/hour; or (iv) endothelin-1+BQ-123. Mean arterial blood pressure and heart rate were monitored daily and blood was obtained for plasma vasopressin on days 3 and 9. On day 10, the rats were euthanized, the hypothalami were removed, and vasopressin messenger ribonucleic acid content was assessed. Results: The pressor effect of in...
Return to Empire: The New U.S. Imperialism in Comparative Historical Perspective*

The widespread embrace of imperial terminology across the political spectrum during the past three years has not led to an increased level of conceptual or theoretical clarity around the word “empi...
Identification and Characterization of Vitamin A-Storing Cells in Fetal Liver: Implications for Functional Importance of Hepatic Stellate Cells in Liver Development and Hematopoiesis

Hepatic stellate cells (HpSTCs) are major regulators of hepatic fibrogenesis in adults. However, their early development in fetal liver is largely unknown. To characterize fetal HpSTCs in the liver, in which hepatic development and hematopoiesis occur in parallel, we determined the phenotypic characteristics of HpSTCs from rat fetal livers, using a strategy focused on vitamin A. Storage of vitamin A in the cytoplasm is a unique characteristic of HpSTCs, permitting identification of them by vitamin A-specific autofluorescence (vA+) when excited with UV light using flow cytometry. A characteristic vA+ cell population was identified in liver as early as 13 days post coitum; it had a surface phenotype of RT1A- intercellular adhesion molecule (ICAM)-1+ vascular cell adhesion molecule (VCAM)-1+ beta3-integrin+. Although nonspecific autofluorescent cells were found with the antigenic profile of RT1A- ICAM-1+ VCAM-1+, they were beta3-integrin- and proved to be hepatoblasts, bipotent hepatic parenchymal progenitors. In addition to expression of classic HpSTC markers, the vA+ cells were able to proliferate continuously in a serum-free hormonally defined medium containing leukemia inhibitory factor, which was found to be a key factor for their replication. These results demonstrated that the vA+ cells are fetal HpSTCs with extensive proliferative activity. Furthermore, the vA+ cells strongly express hepatocyte growth factor, stromal-derived factor-1alpha, and Hlx (homeobox transcription factor), indicating that they play important roles for hepatic development and hematopoiesis. The abilities to isolate and expand fetal HpSTCs enable further investigation into their roles in early liver development and facilitate identification of possibly novel signals of potential relevance for liver diseases.
Examining the Overlap and Prediction of Multiple Forms of Child Maltreatment, Stressors, and Socioeconomic Status: A Longitudinal Analysis of Youth Outcomes

Analyses were conducted to examine the extent of overlap and predictive strength of multiple forms of child maltreatment and stressors internal and external to the family. Findings suggest a strong association between child maltreatment (physical and sexual abuse, neglect, and exposure to domestic violence) and stressors (family conflict, personal problems of parents, and external constraints on the family). After controlling for stressors, family socioeconomic status, and child gender, a general construct of child maltreatment was predictive of internalizing and externalizing behaviors in adolescents. Specific effects of child physical and sexual abuse were revealed in these longitudinal structural equation model tests.
Magnetic properties of sputtered multilayers of Mo/Ni

Abstract We have studied the d.c. magnetization of Mo/Ni artificial superlattices in the temperature range 5–300 K and in magnetic fields of up to 10 7 /4 π Am -1 (10kG). The saturation magnetization and the Curie temperature behavior are consistent with expectations based on thin film effects. However, there are indications of ferromagnetic coupling across the normal metal and the coercive field shows an unexpected peak at a layer thickness of 25 A.
Scanning tunneling microscopy of dimeric and polymeric products of electroreduced [Re(CO)3(4-vinyl,4'-methyl-2,2'-bipyridine)Cl]

Scanning tunneling microscopy (STM) was used to image adsorbed products resulting from electroreduction of (Re(CO){sub 3}(vbpy)Cl) (vbpy = 4-vinyl,4{prime}-methyl-2,2{prime}-bipyridine) on highly oriented pyrolytic graphite (HOPG). STM images, in air, of HOPG electrodes following electroreduction of (Re(CO){sub 3}(vbpy)Cl) (in acetonitrile/0.1 M tetra-n-butylammonium perchlorate) by cycling the potential between 0 and {minus}2.0 V vs a sodium saturated colomel electrode (SSCE) show molecular species uniformly distributed on the surface including approximately dumbbell shaped molecules ({approx} 40 {times} 20 {angstrom}). The size and shape of these aggregates is consistent with products derived from vinyl-vinvyl coupling of Re-Re bonded dimers: ((vbpy)(CO){sub 3}Re-Re(CO){sub 3}(vbpyH-vbpyH)(CO){sub 3}Re-Re(CO){sub 3}(vbpy)). STM images of electrodes prepared by cycling the potential between 0 and {minus}1.45 V vs SSCE (less reducing conditions) show highly nonuniform coating of the surface by polymer. Several polymer morphologies were observed with polymer nucleation preferentially occurring at step sites on HOPG.
LCI reliability and size of language sample

Abstract Language samples were evoked under four stimulus conditions from 36 children between the ages of four and five. The purpose was to evaluate the reliability of the LCI in relation to the size of the language sample. Each sample was divided into five response segments (5, 10, 15, 20 and 25) and was correlated with its total 50 response LCI score. The reliability analysis suggests that LCI scores based on 15 responses are quite satisfactory for most research purposes.
Lubrication and Surface Properties of Roach Cuticle

Using atomic force microscopic and tribometry techniques, we characterized the cuticle surface of the American cockroach (Periplaneta americana) and studied lubrication properties of the wax developed to protect the cuticle. Experimental results showed that the roach cuticle had the ability to self-clean and that there were dimples on its surface to naturally disperse wax. It was observed by changes in friction that a thicker layer of wax was formed at the ventral abdomen, where dimples were present, than at the dorsal abdomen, which had no major features. The wax was found to have similar lubrication properties as commercial automobile oil, but with the ability to form thin films and repel dust. The dust repelling qualities make it a potential candidate for the lubrication of microelectromechanical system and nanoelectromechanical system devices that require supercleaning surfaces that is cost effective.
Accessories for oil filled cable

The development of more satisfactory cable joints, terminals, and reservoirs has greatly simplified the installation of oil filled cable and increased the reliability against mechanical failures.
Evaluation of Paspalum germplasm for variation in leaf wax and heat tolerance

The genus Paspalum contains a number of important forage grasses, including P. dilatatum Poir. (dallisgrass) and P. notatum Flugge (bahiagrass). Even though many Paspalum species are adapted to moist, humid areas, they frequently are subjected to extended periods of drought stress which reduces forage productivity. This study was initiated to determine the range of variation for different indicators of drought tolerance in several Paspalum species. Fifteen species representing a broad cross section of germplasm were grown in a replicated field nursery and sampled for leaf epicuticular wax content on four dates over three years. Wax was extracted with chloroform and quantified by the dichromate oxidation technique. Heat tolerance (solute leakage technique) was also determined by calculating the ratio of the conductivity of the external bathing solution of leaves following a heat treatment to the conductivity of the bathing solution after leaves were boiled. Wax values of the entries ranged from 5.7 to 0.88 mg/dm2. Both relative rankings and absolute wax values were very consistent across all sampling dates. The accessions of Paspalum nicorae Parodi and P. quandrifarum Lam. were consistently high in wax content, while the accessions of P. commune Lillo and P. unispicatum (Scribn. et Merr.) Nash were consistently low. The heat tolerance testing demonstrated that the accession of P. notatum var. saurae Parodi was the most heat tolerant of the entries. Results from this investigation demonstrate the wide range of diversity that exists for both epicuticular wax and heat tolerance within the genus Paspalum.
The Production of Experimental Cancer of the Lung in Mice

Following closely in the wake of the discovery that cancer of the skin can be produced experimentally by the repeated application of tar, attempts have been made, through the years, to induce cancer in practically all of the other body organs. It may be said, that, as a general rule, where a potent tar can be applied repeatedly, or where a sufficient quantity of it can be placed so as to remain immobile for a sufficient length of time, cancer may be induced in a varyingly high percentage of instances. There are regions, however, that tend to defy the experimenter. Among such locations are the lungs. The physical difficulty of applying tar directly to the lung structures is apparent and requires no explanation. The difficulties in the way of making repeated direct applications of tar to the same lung are even more obvious. A survey of the literature shows that the earliest experimental attack on the problem of experimental tar cancer of the lung was made by Murphy and Sturm (1), who noted that when mice were tarred in various skin areas they developed primary tumors of the lung. In one of their groups of mice these investigators observed a 78.3 per cent incidence of primary lung tumors in tarred animals, though no tumors occurred in a control series. Murphy and Sturm designate these lung tumors as “a distinct type of epithelial tumor” and furnish reasons for believing that they are primary neoplasms. Care was taken to kill the animals early enough in life to avoid the possible complicating factor of primary lung tumors incident to age rather than to tar. The authors furnish no dogmatic explanation for the development of the tumors, but they strongly incline to the belief that the tar painting has the constitutional effect of lowering the resistance of the animals, and that local irritation (caused by inhaled particles of shavings, sawdust and chopped food), grafted on the lowered resistance, induces pulmonary tumor formation
Metabolism of hCG and hLH to multiple urinary forms

Abstract Human chorionic gonadotropin (hCG) is synthesized primarily in the placenta while human luteinizing hormone (hLH) is produced in the pituitary. Both hormones are highly homologuous in structure and both appear to be altered to analogous molecular forms as the hormones are proteolytically processed, or metabolized, from tissue of origin, through the circulation, and finally to the urine. Placental hCG is excreted into urine as heterodimeric hormone, heterodimeric nicked hCG, free subunits (some nicked), and predominantly as the hCG β core fragment. A pituitary form of heterodimeric hCG, which is partly sulfated as is pituitary hLH, was recently isolated and is likely the form of hCG observed in the urine of healthy postmenopausal women and nonpregnant premenopausal women as well. A pituitary form of the hLH β core fragment, highly analogous in structure to that of urinary hCG β core fragment, has been used to develop specific monoclonal antibody assays to measure urinary hLH β core fragment which is excreted at significantly higher molar concentrations than is hLH in the urine of ovulating women 1 or 2 days after the LH surge. This fragment of LH appears in the urine of postmenopausal women as well. The development of the capability to distinguish the hCG β core fragment from the hLH β core fragment in urine may have useful applications in tumor marker assays, pregnancy tests, and menopause. While hCG urinary assays have been widely employed, urinary assays for hCG and hLH metabolites are much less used since the urinary molecular forms are only partly known. Our studies of hCG and hLH urinary metabolites are directed towards improvement of the utility of urinary measurements of molecules derived from these hormones. Since many of the molecular forms of these two hormones in urine differ from their forms in blood, it may be necessary to produce new immunoassays as well as novel urinary reference preparations to accurately measure these molecules within their urinary matrix.
Establishment and metabolic analysis of a model microbial community for understanding trophic and electron accepting interactions of subsurface anaerobic environments

Communities of microorganisms control the rates of key biogeochemical cycles, and are important for biotechnology, bioremediation, and industrial microbiological processes. For this reason, we constructed a model microbial community comprised of three species dependent on trophic interactions. The three species microbial community was comprised of Clostridium cellulolyticum, Desulfovibrio vulgaris Hildenborough, and Geobacter sulfurreducens and was grown under continuous culture conditions. Cellobiose served as the carbon and energy source for C. cellulolyticum, whereas D. vulgaris and G. sulfurreducens derived carbon and energy from the metabolic products of cellobiose fermentation and were provided with sulfate and fumarate respectively as electron acceptors. qPCR monitoring of the culture revealed C. cellulolyticum to be dominant as expected and confirmed the presence of D. vulgaris and G. sulfurreducens. Proposed metabolic modeling of carbon and electron flow of the three-species community indicated that the growth of C. cellulolyticum and D. vulgaris were electron donor limited whereas G. sulfurreducens was electron acceptor limited. The results demonstrate that C. cellulolyticum, D. vulgaris, and G. sulfurreducens can be grown in coculture in a continuous culture system in which D. vulgaris and G. sulfurreducens are dependent upon the metabolic byproducts of C. cellulolyticum for nutrients. This represents a step towards developing a tractable model ecosystem comprised of members representing the functional groups of a trophic network.
Primary pleural effusion posttransplant lymphoproliferative disorder: Distinction from secondary involvement and effusion lymphoma

Pleural effusion presentation of posttransplant lymphoproliferative disorder (PTLD) is relatively uncommon. Most examples of effusion-based PTLD have been secondary to widespread solid organ involvement, and are associated with an aggressive clinical course. We report on a case of primary effusion PTLD in a 70-yr-old male liver transplant recipient with a history of hepatitis B infection. Cytomorphologically, the pleural fluid specimen showed a monomorphous population of intermediate to large-sized transformed lymphoid cells, with irregular multilobated nuclear contours and readily identifiable mitotic figures. Flow cytometric immunophenotypic studies revealed a CD5-negative, CD10-negative, lambda immunoglobulin light chain-positive, monoclonal B-lymphocyte (CD19-positive/CD20-positive) population. The immunocytochemical stain for CD30 antigen was negative. In situ hybridization study for Epstein-Barr virus (EBV) early RNA (EBER) and Southern blot analysis for EBV terminal repeat sequences were both positive. Southern blot analysis for human herpes virus-8 (HHV-8) was negative. No solid-organ PTLD was identified, and the cytologic results supported the diagnosis of primary effusion PTLD. Immunosuppression was decreased, and 8 mo following the diagnosis of pleural fluid PTLD, the patient was stable and his pleural effusion had markedly diminished. Recognition of primary effusion PTLD and its distinction from PTLD secondarily involving the body fluids and from other lymphomas is important, since the behavior and prognosis appear different.
Silver atom and strand numbers in fluorescent and dark Ag:DNAs

We use tandem HPLC-mass spectrometry with in-line spectroscopy to identify silver atom numbers, NAg, of 10 to 21 in visible- to infrared-emitting Ag:DNA complexes stabilized by oligonucleotide monomers and dimers. Qualitatively different absorbance spectra from bare, same-NAg silver clusters point to silver-base interactions as the origin for the color of Ag:DNAs.
Brain injuries in polytrauma

The magnitude of the cerebral injury is the ultimate determining factor in survival versus death and ability versus disability in most multiple trauma patients. The acute failures of oxygen transport that occur in these patients can clearly increase the magnitude of the brain injury. This occurs either via cardiopulmonary failure or prolonged epileptic seizures. Both sources must be quickly reversed. The magnitude of the brain injury may also be increased by delayed diagnosis of expanding intracranial lesions. The rapid availability of computed tomography (CT) scans of the head is of great importance in the early diagnosis of intracranial lesions. In the absence of CT scans, skull x-rays and cerebral angiography in association with sequential evaluations of consciousness and neurological function are useful. Medications that change the state of consciousness interfere with such follow-up and should be avoided if at all possible. Acute extradural hematomas are generally not associated with much initial brain damage and produce rapidly progressive brain damage. Therefore, their treatment constitutes an absolute neurosurgical emergency. If these coexist with intra-abdominal bleeding, then 2 operating teams should proceed simultaneously. In contrast, both intracerebral and subdural hematomas reflect relatively severe initial brain damage which cannot be changed and produce a slower rise in pressure and thus a slower rate of destruction of additional brain tissue. The time scale for treatment of these lesions is, therefore, longer than that for extradural hemorrhages. Additional brain damage may also be produced by cerebral edema. The intracranial pressure is best monitored in trauma cases by pressure monitoring bolt. The preferred agents for therapy are clearly mannitol acutely (0.5 to 1.5 g/kg body weight as a single dose) followed by a continuous infusion with an osmolality maintained at 315 to 320 mOsm. Lasix® may also be used. In the absence of control of intracranial pressure, then barbiturate coma may be utilized (3 to 5 mg/kg as an initial dose followed by maintenance of plasma levels at 2.5 to 3.5 mg/100 ml).
Philadelphia’s Trap of Grease. National Energy Policy Versus Urban Realities

This essay contends that national energy policy both purposefully and indirectly disadvantages a Philadelphia-based initiative that would simultaneously foster energy self-reliance, help improve the city’s air quality, lower costs associated with wastewater treatment, and provide an alternative to imported petroleum-based vehicle fuel. Although some of the obstacles confronting this initiative are endemic to the character of Philadelphia’s fractured approach to urban management, this article suggests that a change in national energy policy could do much to enhance Philadelphia’s prospects to develop a commercial-scale biodiesel production facility that exploits a trap grease, an as yet virtually unutilized ingredient for making a biogenic fuel.