cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of Hydrophobic Residue Substitutions with Glutamine on Ca2+ Binding and Exchange with the N-Domain of Troponin C†

Troponin C (TnC) is an EF-hand Ca(2+) binding protein that regulates skeletal muscle contraction. The mechanisms that control the Ca(2+) binding properties of TnC and other EF-hand proteins are not completely understood. We individually substituted 27 Phe, Ile, Leu, Val, and Met residues with polar Gln to examine the role of hydrophobic residues in Ca(2+) binding and exchange with the N-domain of a fluorescent TnC(F29W). The global N-terminal Ca(2+) affinities of the TnC(F29W) mutants varied approximately 2340-fold, while Ca(2+) association and dissociation rates varied less than 70-fold and more than 45-fold, respectively. Greater than 2-fold increases in Ca(2+) affinities were obtained primarily by slowing of Ca(2+) dissociation rates, while greater than 2-fold decreases in Ca(2+) affinities were obtained by slowing of Ca(2+) association rates and speeding of Ca(2+) dissociation rates. No correlation was found between the Ca(2+) binding properties of the TnC(F29W) mutants and the solvent accessibility of the hydrophobic amino acids in the apo state, Ca(2+) bound state, or the difference between the two states. However, the effects of these hydrophobic mutations on Ca(2+) binding were contextual possibly because of side chain interactions within the apo and Ca(2+) bound states of the N-domain. These results demonstrate that a single hydrophobic residue, which does not directly ligate Ca(2+), can play a crucial role in controlling Ca(2+) binding and exchange within a coupled and functional EF-hand system.
A quantitative assessment of F-actin content and distribution in untreated and butyric acid treated murine melanoma B16a tumour cells: a fluorescence image analysis study

Image analysis of phallacidin, a fluorescent stoichiometric probe to F-actin, permitted the cytoskeletal-associated actin 'F-actin' to be visualized morphologically and to be divided into two groups, diffuse and filamentous. The filamentous actin group was categorized further into four subgroups according to the intensity of the phallacidin probe. F-actin groups and subgroups of untreated cells and cells treated with 1.5 mM butyrate acid were analysed independently. Butyric acid treatment significantly increased total actin, defined as diffuse actin, plus filamentous subgroup actins 1-4. Specifically, butyric acid-treatment increased filamentous subgroup actin 1.
The effect of substrate composition and condition on resorption by isolated osteoclasts

Osteoclasts isolated from 10-day-old rabbits were studied in a cell culture system to obtain further insight into the possible mechanisms involved in the process of bone resorption. Osteoclasts were cultured on the surfaces of devitalized mammalian bones, a composite of polycrystalline synthetic hydroxyapatite and geological single crystal hydroxyapatite. The structural interaction of osteoclasts with these various substrates was morphologically characterized by using a scanning electron microscope. Viable osteoclasts were observed to adhere and extend pseudopodia and filopodia for all cases of calcium-phosphate surfaces. However, actual resorbing process was only observed in devitalized bone surfaces. Resorption pits of various sizes were found in multiple series and showed a preference for mineral-exposed area over collagen-exposed area. The difference observed between resorption of those areas of bone surface and the failure of osteoclasts to resorb non-tissue substrates are discussed in relation to current theories of the mechanisms of mineral dissolution and resorption in mammalian calcified tissues.
Octalog III: The Politics of Historiography in 2010

The field of rhetoric has historically been defined by competing visions of language and education—and by the conviction that these debates have significance for public life. James J. Murphy highli...
Phase conjugation in underwater acoustics

Phase‐conjugate mirrors are used in optics to compensate for aberrations caused by inhomogeneities in the propagation medium and by imperfections in optical components. In acoustics, analogous behavior can be achieved by a time‐reversed retransmission of signals received by an array. Compensation for multipath propagation and array imperfections is automatic and does not require knowledge of the detailed properties of either the medium or the array. The behavior of acoustic phase‐conjugate arrays is illustrated in several examples, some highly idealized and some more realistic. The effects of aperture size and inhomogeneities in the propagation medium are treated for both the near‐field and far‐field regions. It is concluded that phase‐conjugate arrays offer an attractive approach to some long‐standing problems in underwater acoustics.
Intracellular Microrheology in the Presence of Myosin-Generated Forces in Living Cells

The mechanics of cells are governed by a network of cytoskeletal filaments and molecular motor forming a dynamic mechanical entity. A recent experimental study by Mizuno showed local shear modulus of a synthesized cytoskeletal network could increase in the presence of myosin-generated internal stresses. It was speculated whether similar behaviors could also take place in cells. To examine this, we used an experimental method similar to Mizuno's that combined active and passive microrheology to measure myosin-generated fluctuating force and the local intracellular stiffness. Our data obtained from measurements in 15 HeLa cells showed a linear relationship between the magnitude of the fluctuating forces and the time-averaged shear modulus. Moreover, when myosin activities were inhibited by ML7, we saw a dramatic decrease in the intracellular forces, but surprisingly no significant changes were observed in the time-averaged intracellular stiffness by ML7. While we did not see a direct correlation between the mean intracellular shear modulus and the motor-generated fluctuating force, we did observe an increase in the fluctuation of the shear modulus with increasing motor forces.While it is not clear why results from the intracellular study were so different from the actin construct, some differences between the two systems may be attributed to the difference. First, the intracellular fluctuating forces were found to be weaker than that in the actin construct, thus perhaps not strong enough to modulate the cell stiffness. Secondly, the steady-state internal tension, which could dictate mechanical proprieties of a network, may be different between the two systems. Unfortunately, the experimental method we used could only measure fluctuating forces but not the steady-state tension in the system. Further studies that measure both fluctuating and steady-state forces at the same time may be required to address this problem.
RF resonance in two-dimensional electron transport in the Wigner solid regime

Abstract We have measured the small-signal AC response (from 300 kHz to 3 MHz) in the presence of a DC current in the reentrant insulating phase around Landau level filling factor ν = 1 5 in a high quality two-dimensional electron system in GaAs AlGaAs and observed a broad resonance on top of a background that changes from being capacitive at low currents to inductive at high currents. The resonance frequency which shows a sublinear dependence on the DC current, is interpreted as that of the washboard oscillations of the Wigner crystal.
Sex differences in adaptive downregulation of pre-macula densa sodium transporters with ANG II infusion in mice

An increase in blood pressure (BP) due to angiotensin II (ANG II) infusion or other means is associated with adaptive pressure natriuresis due to reduced sodium reabsorption primarily in proximal t...
Chiral stationary phase designed for β-blockers

Abstract A chiral stationary phase (CSP) derived from an N-3,5-dinitrobenzoyl-α-amino phosphonate was prepared for the direct separation of the enantiomers of underivatized β-blockers. Structure—chromatographic activity relationships for β-blockers and closely related analogues are reported for this CSP and are found to be consistent with the model used to design this CSP. The effect of temperature on the chromatographic behavior of β-blocker enantiomers is unusual. A reduction in temperature reduces the retention of the less retained enantiomer and increases the retention of the more retained enantiomer without appreciable band broadening.
Optimization of hybrid steel plate girders

Abstract An efficient procedure is presented for minimum weight design of unstiffened and stiffened hybrid steel plate girders subjected to arbitrary loading using the General Geometric Programming technique. The nonlinear optimization problem is formulated on the basis of the current American Institute of Steel Construction specification. Four examples are presented to show the application of the algorithm for practical optimization of hybrid steel plate girders.
SIR 2004 Film Panel Case: hereditary hemorrhagic telangiectasia of the liver with mesenteric steal.

A 48-year-old woman with a 16-month history of intermittent abdominal pain and palpitations was admitted with increasingly severe epigastric pain, early satiety, and 20-pound weight loss. The patient reported constant upper abdominal pain that became severe after meals. As a result of the weight loss and severe postprandial pain, total parenteral nutrition was initiated. The patient’s medical history was significant for cholecystectomy and presumed peptic ulcer disease treated with proton pump inhibitors and H2blockers. Medical history was negative for episodes of gastrointestinal bleeding, epistaxis, or alcohol abuse, and there was no significant family history. Physical examination on presentation revealed normal vital signs, a cardiac systolic ejection murmur, and a bruit in the epigastrium. Laboratory evaluation was notable for a mildly increased alkaline phosphatase level of 168 U/L (normal, 35–125 U/L), but complete blood count and liver function test results were otherwise normal. Albumin was slightly decreased at 3.1 g/dL (normal, 3.5–5.0 g/dL), and coagulation study results were at the upper limits of normal. Computed tomography (CT) of the thorax, abdomen, and pelvis were performed, in addition to selective angiography of the celiac artery and superior mesenteric artery (SMA).
Observation of a new surface mode on a fluid‐saturated permeable solid

Almost ten years ago, S. Feng and D. L. Johnson predicted the presence of a new surface mode on a fluid/fluid‐saturated porous solid interface with closed surface pores [J. Acoust. Soc. Am. 74, 906 (1983)]. We found that, due to surface tension, practically closed‐pore boundary conditions can prevail at an interface between a nonwetting fluid (e.g., air) and a porous solid saturated with a wetting fluid (e.g., water or alcohol). Surface wave velocity and attenuation measurements were made on alcohol‐saturated porous sintered glass at 100 kHz. The experimental results show clear evidence of the new ‘‘slow’’ surface mode predicted by Feng and Johnson.
The other intestinal protozoa: Enteric infections caused by Blastocystis hominis, Entamoeba coli, and Dientamoeba fragilis

Abstract Pediatricians frequently are confronted with clinical microbiology laboratory reports about a fecal examination that was determined to be positive with Dientamoeba fragilis, Blastocystis hominis, or Entamoeba coli. Increasingly, these organisms are becoming leading causes of parasitic infection in North America. Evidence is provided that these unique organisms may be pathogenic under some circumstances. Some guidelines for management and treatment are also discussed. Copyright © 2000 by W.B. Saunders Company
Remediation of Brine-Contaminated Soils Using Atriplexspp. (Chenopodiaceae)

ABSTRACT The ability of some halophytes to accumulate salts may make them helpful in remediating soil contaminated with produced water and drilling mud from oil and gas exploration and production. ...
A procedure for rapid isolation of both groE protein and glutamine synthetase from E. coli

Abstract The most abundant and persistent contaminant of glutamine synthetase as isolated from Escherichia coli by the method of Woolfolk and Stadtman has been purified and identified as the protein product of the groE gene ( pgroE ). The identification of this protein as pgroE is based on precipitation by anti pgroE antiserum, mobility on sodium dodecyl sulfate and nondenaturing polyacrylamide gels, and molecular images in electron micrographs. The sedimentation and diffusion constants of pgroE have been determined and compared to values measured for the protein isolated by other methods. Based on experience in purifying glutamine synthetase, a procedure has been designed that is suitable for isolating both glutamine synthetase and pgroE . The procedure is rapid and is suitable for preparing hundreds of milligrams of both proteins. One step of considerable utility is that of blue dextran affinity chromatography of glutamine synthetase.
Malignant Cytological Washings from Radical Prostatectomy Specimens: A Possible Mechanism for Local Recurrence of Prostate Cancer Following Surgical Treatment of Organ Confined Disease

AbstractPurpose: Local recurrence of prostate cancer following complete and successful resection of organ confined disease has been variably reported in men. We hypothesized that observed secretions from the cut distal urethra during radical prostatectomy may contain malignant prostatic epithelial cells and contribute to this problem.Materials and Methods: A prospective study was done of prostate cytology specimens from 50 consecutive men with clinically organ confined adenocarcinoma of the prostate undergoing radical retropubic or radical perineal prostatectomy. Direct cytological evaluation by 1 examiner was used to identify malignant or benign cells in these washings.Results: Of 33 radical perineal and 17 radical retropubic prostatectomy specimens organ confinement was confirmed in 58 percent. Malignant prostatic epithelial cells were observed in 24 percent of all cytology specimens. Of cytological washings from prostates with pathologically confirmed organ confined cancers 17 percent showed malignant ...
Event shape engineering with ALICE

Abstract The strong fluctuations in the initial energy density of heavy-ion collisions allow an efficient selection of events corresponding to a specific initial geometry. For such “shape engineered events”, the elliptic flow coefficient, v 2 , of unidentified charged particles, pions and (anti-)protons in Pb–Pb collisions at s NN = 2.76 TeV is measured by the ALICE collaboration. v 2 obtained with the event plane method at mid-rapidity, | η | 0.8 , is reported for different collision centralities as a function of transverse momentum, p T , out to p T = 20 GeV / c . The measured v 2 for the shape engineered events is significantly larger or smaller than the average which demonstrates the ability to experimentally select events with the desired shape of the initial spatial asymmetry.
Femoral venous flow dynamics during intraperitoneal and preperitoneal laparoscopic insufflation

Background: Laparoscopic herniorrhaphy may be performed using an intraperitoneal or a preperitoneal approach. Anecdotal and experimental evidence indicates that alterations in lower extremity venous flow, which occur during intraperitoneal laparoscopic insufflation, may be associated with an increased risk of deep vein thrombosis. However, no study has directly compared femoral venous flow during intraperitoneal insufflation with that during preperitoneal insufflation.
Surgical experience with implantable insulin pumps

Abstract Background: A recent Veterans Affairs cooperative trial demonstrated that intensive insulin therapy via an implantable pump with intraperitoneal insulin delivery reduced glycemic variability and improved quality of life compared with multiple daily insulin injections. Our aim was to determine perioperative morbidity and assess long-term function of the implantable insulin pump. Methods: Fifty-one adult patients with type 2 diabetes had infusion pumps placed over a 2-year period at seven VA Medical Centers as part of a randomized prospective study. Results: All pumps were placed successfully. There were two (4%) perioperative complications. There were no wound complications. Duration of pump use ranged from 12 to 25 months (mean 20). Catheter obstruction (57%) and pump malfunction (25%) were the most common reasons for pump explantation. Catheter occlusions increased after 12 months. Catheter occlusion was treated by percutaneous rinse procedure in 75% and revisional procedures in 31% of patients. Conclusions: Implantable insulin pumps can be placed with minimal surgical morbidity. Attention to surgical detail and infusion protocol permits satisfactory long-term function. Pump/catheter complications increase with time but are usually resolvable by either operative or percutaneous manipulations.
Laser beam profile shaping with binary diffraction gratings

Abstract A laser beam shaper has been developed to achieve efficient conversion from a gaussian intensity profile to a flattop intensity profile in far-field or focal-plane domains. This beam shaper consists of a diffraction grating and an anamorphic prism beam compressor. The diffraction grating phase modulates the near field of the laser beam to generate a far-field flattop intensity profile, whereas the compressor produces the necessary profile eccentricity. The position, the relief height, and the relative grating periodicity of the beam shaper can be used to change the shape of the beam profile in a flatness-versus-rolloff tradeoff.
Compatibility of Various Materials with Oral Tissues. II: Pulp Responses to Composite Ingredients

Eight ingredients of composite materials were evaluated individually for pulp irritation. None caused significant inflammation as evidenced by its average response. No abscess formations or lesions predominating in leukocytes occurred.
Place and culture-based professional development: cross-hybrid learning and the construction of ecological mindfulness

This paper approaches mindfulness, an awareness of internal and external realities, as a culturally-shaped habit of mind. Findings of a cross-cultural study and popular sayings that reflect America’s cultural orientation to consumption and competition are contrasted with findings from Hawaiian language newspapers, traditional cultural practices, and Hawaiian sayings that indicate an orientation to ecological mindfulness that increased the resilience of fragile social ecosystems. Marginalization of indigenous culture, language, and knowledge and cultural differences between teachers and indigenous students are proposed as a contributing factor to lower science performance of Native Hawaiian students in mainstream schools. Two professional development projects designed to reduce conflicts between culture and science instruction are presented. Findings from these projects suggest alignment of science inquiry with indigenous cultural knowledge and practices oriented to sustainability supports the development of teachers’ ecological mindfulness as indicated by increased awareness of, interest in, and incorporation of place and culture-based based resources into their instruction. Teacher feedback indicates that mapping technologies that enable teachers to visualize and integrate indigenous place-based Hawaiian knowledge with science inquiry are promising instructional strategies.
SAR arc and concurrent auroral electrojet activity

Abstract A distinct SAR arc was observed on the night of 25/26 September 1978 (EST) from Albany (42.68°N, 73.82° W), New York. The photometric observations of the arc were compared with concurrent ground-based magnetometer observations of the auroral electrojets. Results of the combined observations reveal that there is a close relationship of the arc to the concurrent electrojets. Specifically, it was found that: (1) at the beginning of the arc's appearance near local midnight, the position of the intercept point of the magnetic field line threading the arc at auroral height coincided with the eastward auroral electrojet center; (2) the intensity variation of the arc followed closely that of the westward electrojet, with a time lag of 10–20 min after the arc reached its peak intensity; and (3) the arc showed equatorward movement in general, however, during the periods when the electrojet moved rapidly for a great distance, the arc also moved in the same direction but to a lesser degree.
Spectral dimension of bosonic string theory

Given that the scale of quantum gravity is not experimentally accessible, one naturally resorts to mathematical consistency as a measure for a good candidate theory to replace general relativity at high energies. Reproducing the semiclassical results of black hole entropy has become a standard test for any prospective theory of quantum gravity. It is often argued that another such commonality, albeit less known, is the similar fractal behavior. It is shown that many, if not all, approaches to quantum gravity predict a spectral dimension of 2 in ultraviolet regime. In this paper, by computing the heat kernel, we show that the spectral dimension of closed bosonic string theory is 26. We discuss the implications of this disparity.
Cervical hernia of the lung

R E F E R E N C E S I. Bratton, A. B., and Robinson, S. M. G.: Gliornata of the nose and oral cavity: A report of two cases, J. Path. & Bact. 58: 643, 1946. 2. Low, N. L., Scheinberg, L., and Anderson, D. H.: Brain tissue in the nose and throat, Pediatrics 18: 254, 1956. 3. Franchini, Y., and Schemper, J.: Heterotopia neurogliea del cavum nasofaringeo en una nifia de tres meses de edad, Prensa Med. Argentina 48: 3210, 1961. 4. Birrell, J. F., Tevendale, J., and Bain, A. D.: Glioma of the nasopharynx, J. Laryng. 80: 1182, 1966. 5. Zarem, It. A., Gray, G. F., Morehead, D., and Edgerton, M. T.: Heterotopic brain in the nasopharynx and soft palate: Report of two cases, Surgery 61: 483, 1967. 6. Shapiro, M. J., and Mix, B. S.: Heterotopic brain tissue of the palate. A report of two cases, Arch. Otolaryng. 87: 522, 1968. 7. Smith, K. R., Schwartz, H. G., Luse, S. A., and Ogura, J. H.: Nasal gliomas: A report of five cases with electron microscopy of one, J. Neurosurg. 20: 968, 1963. 8. Walker, E. A., and Resler, D. R.: Nasal glioma, Larnygoseope 73: 93, 1963. 9. Black, B. D., and Smith, D. E.: Nasal gIioma. Two cases with recurrence, Arch. Neurol. Psychiat. 64: 614, 1950.
Does the Number of Subject Headings on a Bibliographic Record Affect Circulation Intensity

ABSTRACT Using a random sample drawn from the political science collection at Southeast Missouri State University during a massive weeding project, the investigator examined whether an increase in the number of subject headings on bibliographic records translated into an increase in circulation. The answer was no. Indeed, instead of improving circulation, books with the highest number of subject headings considered in the study, i.e., five, circulated the least and had the highest incidence of not circulating at all. Other findings were: (a) the average number of subject headings per bibliographic record was 2.2, (b) the best circulation was for books with one and two subject headings, and (c) no matter the number of subject headings, most of the books only circulated once. To stop the downward slide in circulation, new strategies will need to be found.
Optimisation of hard pretzel production

Summary Absence of a thorough understanding of the baking conditions on hard pretzel quality has resulted in considerable loss of production and on productivity. Baking time, oven zone 1 temperature, drying time and kiln drying temperature were identified as important factors affecting pretzel quality in modern pretzel production, from a total of eleven factors following a screening experiment design. A central composite circumscribe design was then employed to optimise these four variables. The test for lack of fit was not significant (P < 0.05) for the responses, except for colour a* values. The analysis of variance of the responses indicated that models explained 99%, 91% and 87% variability for moisture content, ΔEab and pasting time, respectively. The four variables were optimised when pretzel moisture content, ΔEab and pasting time were considered simultaneously using desirability function approach. Validation experiment results revealed that the two most important qualities of pretzel, moisture content and ΔEab could be reliably predicted.
The Effects of a State Need-based Access Grant on Traditional and Non-traditional Student Persistence

In 2011–2012, more than 236.7 billion dollars of student financial aid was disbursed to undergraduate and graduate students at postsecondary institutions in the United States. Today, many groups and organizations are advocating for financial aid to increase student access and success as well as to assist the neediest students. The purpose of this study was to assess the impact of the College Access Program (CAP) grant, which is a need-based state access grant, on persistence from the first to second year at Kentucky’s 2- and 4-year public institutions using logistic regression and propensity score matching. A dependent full-time student who receives the CAP grant has 51% greater odds of persisting from the first to second year, but receiving the CAP grant was not statistically significant for part-time or independent students. These findings have practical and policy implications if institutional, state and federal financial aid is to align to increase student access and success.
DNA methylation in nasal epithelial cells from smokers: identification of ULBP3-related effects

We previously demonstrated that, in nasal epithelial cells (NECs) from smokers, methylation of an antiviral gene was associated with impaired antiviral defense responses. To expand these findings a...
Objective Measurement of Connective Tissue Tenacity of Poultry Meat

SUMMARY— A direct, objective method was developed for measuring the cohesive force holding the fibers and fiber bundles of poultry meat together, i.e., the connective tissue tenacity. The method consists of cutting out uniform cylinders of cooked muscle with the fibers parallel to the plane ends of the cylinder, attaching metal plates to the cylinder ends by a special adhesive that forms strong bonds with moist tissue, and measuring the force and work required to tear the meat sample apart in a recording tensile tester. Ability of the method to measure the cohesiveness between fibers, independent of the force required to shear across the fibers, was evaluated by determining connective tissue tenacity, shear force, alkali insoluble hydroxyproline (index of collagen), and taste panel reactions on cooked muscle samples varying with respect to age of bird, post-mortem aging condition, freeze-drying, and cooking time. Connective tissue tenacity was directly correlated with alkali insoluble hydroxyproline (r = 0.91, P < 0.001), inversely related to cooking time, and in general appeared to be a good measure of the connective tissue component of toughness as differentiated from the component related to force required to shear across the fibers. The method will be useful in objectively measuring the quality defect of lack of cohesiveness in canned, freeze-dried, and irradiated poultry meat, and should be of general value in all research on meat quality.
Laparoscopic sleeve gastrectomy for the super-super-obese (body mass index >60 kg/m(2)).

Purpose We reviewed our experience of performing laparoscopic sleeve gastrectomy (LSG) in super-superobese (body mass index >60 kg/m2) patients and compared our results with those of laparoscopic adjustable gastric banding (LAGB) performed in similar patients.
XPS oxygen line broadening in lead zirconium titanate and related materials

Abstract Synthesis of the Pb(ZrxTi1−x)O3 (PZT) ceramics requires mixing materials such as PbO, TiO2 and ZrO2. X-ray photoelectron spectroscopy (XPS) of PZT thin films and other Pb-based materials shows structure and lineshape changes in the O 1s line which can be described in term of the shifts in binding energies of O 1s electrons in their constituents. The hybridization and overlap of the density of states of the elements in the molecule result in softening the bonds, shifting the oxygen peak toward a lower binding energy. Other lead-based materials such as PbZrO3 (PZO) and PbTiO3 (PTO), which also contain the same species, have been studied for comparison. The results show similar behavior of the oxygen peaks to that in PZT.
The reliability of the Thematic Apperception Test.

Controversy over the TAT's reliability may stem largely from the mis-application of traditional psychometric measures, which are inappropriate to this test. The TAT is implicitly based on a multiple regression model, for which coefficient alpha is not appropriate. Also, test-retest correlations may be adversely affected by the standard instructions to write a "creative" story. In a test-retest study, 47 high school students retook the TAT after a year with instructions designed to break the implicit set to produce a new and different story from that previously written. The test-retest correlations were r = .48 (need for affiliation) and .56 (need for intimacy), or approximately the same as those for, e.g., the MMPI, 16PF, and CPI, It was demonstrated that this high stability over time was not due to subjects' recalling and repeating previous responses. Finally, it was shown that alpha considerably underestimated the test-retest reliability, contrary to assumptions of classical psychometrics.
Encounter rates with conspecific males influence female mate choice in a naturally hybridizing fish

Mate choice can vary in response to internal or external conditions that alter the costs and benefits of being choosy. The relationship between mate choice and hybridization, however, is not well understood. An important influence on mate choice is the rate at which potential mates are encountered: low rates increase sampling costs, favoring reduced choosiness. We investigated the influence of conspecific encounter rate on female choice in a naturally hybridizing species of swordtail, Xiphophorus birchmanni. We exposed females to conspecific males, followed by either no delay or a long (24 h) delay before their next male encounter. In this second encounter, females were offered the choice of a heterospecific (X. malinche) male only or a choice between a conspecific and heterospecific male. When not given a choice between 2 males, females spent more time with the heterospecific following a long delay between male encounters than after no delay, suggesting a decrease in choosiness. When offered a choice between males, however, females preferentially associated with the conspecific, regardless of the time between male encounters. These results suggest that females are sensitive to conspecific encounter rate but may employ a sample-based (vs. standard-based) comparison tactic, which could make hybridization less likely. We also found that, contrary to our expectations, females with only the heterospecific male to choose from visited him more frequently following a long delay between male encounters than following no delay, possibly indicating an increase in sampling effort. Our study highlights the potential importance of context-dependent mate choice in animal hybridization. Key words: encounter rate, hybridization, mate choice, mate density, sampling tactic, Xiphophorus. [Behav Ecol]
Determination of free chlorine in water by chemiluminescence reaction with hydrogen peroxide

The analytical utility of the hydrogen peroxide—hypochlorite singlet oxygen chemiluminescence reaction for the determination of hypochlorite in water is investigated. Effects of pH and hydrogen peroxide concentration are discussed and interference data for over 35 species in the absence and presence of hypochlorite are provided. The limit of detection is 4 μg l-1 with a usable non-linear calibration curve up to about 200 μg l-1. The new method is shown to be relatively free from interferences and to give results for tap water comparable to a standard colorimetric method based on a reaction with N, N-diethyl-p-phenylenediamine.
Induction of microsomal dimethylnitrosamine demethylase by pyrazole

Abstract Pyrazole, a potent inhibitor of alcohol dehydrogenase, was found to be a potent inducer of the activity of low (iK m ) dimethylnitrosamine demethylase (DMN-d). One injection of pyrazole (200 mg/kg body wt) to weanling Wistar rats changed the microsomal DMN demethylase activity by 1.7, 1.9 and 2.5 times the control values at 6, 12 and 24 hr after the injection respectively. Pyrazole administration reduced arylhydrocarbon hydroxylase (AHH) activity. When animals were injected with pyrazole (200 mg/kg body wt) for 1, 2, 3 or 4 consecutive days, the values for DMN-d activity were 277, 297, 306 and 319% of the control values. The corresponding values for AHH were 91, 67, 57 and 45% for l, 2, 3 and 4 injections respectively. Pyrazole-induced DMN-d activity was NADPH dependent and was inhibited by CO; n -butanol gave a 50% inhibition at a concentration of 2 × 10 −3 M. The corresponding value for metyrapone was 1 × 10 −2 M. Cytochrome P-450 was slightly increased by pyrazole and its CO-complex gave an absorption maximum around 451 nm. When the microsomal proteins were separated using sodium dodecylsulfate (SDS)-polyacrylamide gel electrophoresis, a large increase in a band at about 51,000 daltons was found in the liver microsomes of pyrazole-treated animals.
Cytoplasmic inclusion bodies in Escherichia coli producing biosynthetic human insulin proteins

Escherichia coli that has been genetically manipulated by recombinant DNA technology to synthesize human insulin polypeptides (A chain, B chain, or proinsulin) contains prominent cytoplasmic inclusion bodies. The amount of inclusion product within the cells corresponds to the quantity of chimeric protein formed by the bacteria. At peak production, the inclusion bodies may occupy as much as 20 percent of the Escherichia coli cellular volume.
Hem-1: Putting the “WAVE” into actin polymerization during an immune response

Most active processes by immune cells including adhesion, migration, and phagocytosis require the coordinated polymerization and depolymerization of filamentous actin (F-actin), which is an essential component of the actin cytoskeleton. This review focuses on a newly characterized hematopoietic cell-specific actin regulatory protein called hematopoietic protein-1 [Hem-1, also known as Nck-associated protein 1-like (Nckap1l or Nap1l)]. Hem-1 is a component of the “WAVE [WASP (Wiskott-Aldrich syndrome protein)-family verprolin homologous protein]” complex, which signals downstream of activated Rac to stimulate F-actin polymerization in response to immuno-receptor signaling. Genetic studies in cell lines and in mice suggest that Hem-1 regulates F-actin polymerization in hematopoietic cells, and may be essential for most active processes dependent on reorganization of the actin cytoskeleton in immune cells.
In vivo existence of left-handed DNA.

Abstract A genetic-biochemical assay has been developed to investigate the in vivo existence and consequences of unusual DNA structures. Left-handed DNA was shown to exist in living Escherichia coli . The Eco RI methyl-transferase gene (temperature-sensitive) was cloned to serve as a probe for perturbed GAATTC sites in vivo. This plasmid was cotransformed with different plasmids containing inserts that had varying capacities to form left-handed helices or cruciforms with a target EcoRI site in the center or at the ends of the inserts. Inhibition of methylation in vivo was found for the stable inserts with the longest left-handed helices. In vitro methylation with the purified M · Eco RI enzyme agreed with the in vivo results.
The cellular mode of action of the anti-epileptic drug 5, 5-diphenylhydantoin

THE molecular basis of the many effects of 5,5-diphenylhydantoin (DPH, Dilantin) remains obscure. In addition to being the drug of choice in the prevention of seizures1, DPH is used to correct cardiac arrhythmias (mainly those caused by digitalis)2, and to control myokymia (continuous muscle fibre activity)3, and excessive secretion of insulin4 or anti-diuretic hormone5. Side effects include hypotension, hyperglycaemia and disturbances of calcium homeostasis6. Among the actions proposed for DPH are stimulation of active sodium/potassium transport7, inhibition of passive sodium influx in stimulated (but not in resting) cells8,9, reduction of calcium influx10,11, and specific interference with synaptic transmitter movements12. We report here that DPH does not affect active sodium transport, but blocks passive resting sodium channels in much the same way as tetrodotoxin (TTX) does, and we suggest that from this elementary action may follow many of the drug's therapeutic, adverse, and in vitro effects.
The Effects of a Rectangular Rapid-Flashing Beacon on Vehicle Speed

In 2008, nearly 31% of vehicle fatalities were related to failure to adhere to safe vehicle speeds (National Highway Traffic Safety Administration [NHTSA], 2009). The current study evaluated the effect of a rectangular rapid-flashing beacon (RRFB) triggered by excessive speed on vehicle speed using a combined alternating treatments and reversal design. The percentage of vehicles traveling above 41 mph (66 km per hour) decreased by 20%, and speed distributions showed a shift toward lower speeds during the RRFB condition.
Point Defect Distributions in ZnSe Crystals: Effects of Gravity Vector Orientation During Physical Vapor Transport Growth

ZnSe crystals were grown by the physical vapor transport technique under horizontal and vertical (stabilized and destabilized) configurations. Secondary ion mass spectroscopy and photoluminescence measurements were performed on the ZnSe samples to map the distributions of [Si], [Fe], [Cu], [Al] and [Li or Na] impurities as well as Zn vacancy, [V(zn)]. The annealings of ZnSe under controlled Zn pressures were studied to correlate the measured photoluminescence emission intensity to the equilibrium Zn partial pressure. In the horizontal grown crystals the segregations of [Si], [Fe], [Al] and [V(zn)] along the gravity vector direction were observed whereas in the vertically stabilized grown crystal the segregations of these point defects were radially symmetrical. No apparent pattern was observed on the measured distributions in the vertically destabilized grown crystal. The observed segregations in the three growth configurations were interpreted based on the possible buoyancy-driven convection in the vapor phase.
Heat Removal from Mass Concrete Footing

Removing heat from mass cement concrete footings during initial construction is vital to ensure the quality of the footings after curing. When the temperature of concrete exceeds 70°C, heat released from the hydration of cement can initiate microscopic cracks that may grow larger during or after curing. The temperature of a mass concrete structure can be controlled by various means, depending on the situation. With temperature data collected from a large footing for a bridge column of the ongoing I-580/I-680 Interchange Project, temperature variations were modeled with time and location in a large concrete footing by means of the Fourie—Biot heat conduction equation. Agreement between analytic predictions and field data was found for the physical parameters characterizing the reactions and material properties of the concrete. Possible ways of lowering the concrete temperature are suggested for the future San Francisco—Oakland Bay Bridge East Spans Project.
Meron-cluster simulation of the theta vacuum in the 2D O(3) model.

The 2D O(3) model with a $\ensuremath{\theta}$ vacuum term is formulated in terms of Wolff clusters. Each cluster carries an integer or half-integer topological charge. The clusters with charge \ifmmode\pm\else\textpm\fi{}\textonehalf{} are identified as merons. At $\ensuremath{\theta}=\ensuremath{\pi}$ the merons are bound in pairs inducing a second order phase transition at which the mass gap vanishes. The construction of an improved estimator for the topological charge distribution makes numerical simulations of the phase transition feasible. The measured critical exponents agree with those of the $k=1$ Wess-Zumino-Novikov-Witten (WZNW) model. Our results are consistent with Haldane's conjecture fro 1D antiferromagnetic quantum spin chains.
Induction of Cyp1a-1 and Cyp1a-2 gene expression by a reconstituted mixture of polynuclear aromatic hydrocarbons in B6C3F1 mice

The potential non-additive interactions of polynuclear aromatic hydrocarbon (PAH) mixtures as inducers of Cyp1a-1 and Cyp1a-2 gene expression were investigated in B6C3F1 mice using a reconstituted PAH mixture. The chemical composition (% by weight) of the reconstituted PAH mixture was: 2-ring PAHs--indan (0.22), naphthalene (23.8), 2-methylnaphthalene (23.2) and 1-methylnaphthalene (13.3); 3-ring PAHs--acenaphthylene (7.7), acenaphthene (0.6), dibenzofuran (0.7), fluorene (4.3), phenanthrene (10.5) and anthracene (3.4); > or = 4-ring PAHs--fluoranthene (2.4), pyrene (4.3), benz[a]anthracene (1.4), chrysene (1.5), benzo[b]fluoranthene (0.8), benzo[k]fluoranthene (0.9) and benzo[a]pyrene (0.9). The composition of the 2-, 3- and > or = 4-ring PAH fractions were based on the relative concentration of individual PAHs as noted above. The > or = 4-ring PAH fractions were based on the relative concentration of individual PAHs as noted above. The > or = 4-ring PAH fraction and reconstituted mixture induced hepatic microsomal ethoxyresorufin O-deethylase (EROD) activity and Cyp1a-1 mRNA levels, whereas the 2- and 3-ring PAHs were only weakly active. Direct comparison of the potencies of the reconstituted mixture and > or = 4-ring PAHs showed that the Cyp1a-1 induction activity of the reconstituted mixture was due to the > or = 4-ring PAHs. The reconstituted PAH mixture and > or = 4-ring PAHs also induced Cyp1a-2 hepatic mRNA levels and microsomal methoxyresorufin O-deethylase (MROD) activity; however, their dose-response curves indicated that the reconstituted PAH mixture was more potent as a Cyp1a-2 inducer than the > or = 4 ring PAHs. The differences in potency were due to 3-ring PAHs which were found to be strong inducers of hepatic Cyp1a-2 mRNA levels and microsomal MROD activity at the lowest dose administered (37 mg/kg). The 3-ring mixture caused a maximal 29-fold increase in hepatic MROD activity at a dose of 292 mg/kg, but only 28% of maximal induction of EROD activity. Northern analysis of liver mRNA from mice treated with 3-ring PAHs showed that there was minimal induction of Cyp1a-1 mRNA levels. The 3-ring PAHs did not competitively bind to the mouse hepatic cytosolic aryl hydrocarbon (Ah) receptor suggesting that 3-ring PAHs are a new class of Cyp1a-2 inducers which do not act through the Ah receptor.
Effects of Acute Respiratory Acidosis on Blood Lactate Concentration

The effect of acute hypercapnia upon blood lactate concentration has been studied in anesthetized, curarized dogs. In all experiments a significant and consistent fall in blood lactate to less than half the control value was demonstrated. These observations complement those demonstrating the well-known rise in blood lactate in alkalotic states and suggest that the effect of alteration of blood pH upon glycolysis extends to the acid range of pH values.
It's Time to Transform Social Studies Teaching

(1996). It's Time to Transform Social Studies Teaching. The Social Studies: Vol. 87, No. 4, pp. 149-151.
SecA protein: autoregulated initiator of secretory precursor protein translocation across the E. coli plasma membrane.

Several classes ofsecA mutants have been isolated which reveal the essential role of this gene product forE. coli cell envelope protein secretion. SecA-dependent,in vitro protein translocation systems have been utilized to show that SecA is an essential, plasma membrane-associated, protein translocation factor, and that SecA's ATPase activity appears to play an essential but as yet undefined role in this process. Cell fractionation studies suggested that SecA protein is in a dynamic state within the cell, occurring in soluble, peripheral, and integral membraneous states. These data have been used to argue that SecA is likely to promote the initial insertion of secretory precursor proteins into the plasma membrane in a manner dependent on ATP hydrolysis. The protein secretion capability of the cell has been shown to translationally regulatesecA expression with SecA protein serving as an autogenous repressor, although the exact mechanism and purpose of this regulation need to be defined further.
Development of single grating x-ray Talbot interferometer as a feedback loop sensor element of an adaptive x-ray mirror system

The initial result of using a single 2-D checkerboard phase-grating Talbot interferometer as a feed-back loop sensor element of an adaptive x-ray mirror system is reported. The test was performed by measuring the surface profile of a deformable Pt coated Silicon mirror at five different actuation states. The reflected beam was detected at the fractional Talbot distance of a π/2 phase grating. The measured interferograms were de-convolved using the spatial harmonic imaging technique to extract the phase and amplitude of the reflected wavefront. The wavefront was then propagated to the mirror center to retrieve the surface profile of the mirror. The activation of a single actuator was easily detected from the reconstructed surface profile of the mirror. The presented results indicate that the single phase-grating x-ray Talbot interferometer is capable of sensing nano-meter scale profile changes of an adaptive mirror.
Time use and food pattern influences on obesity.

The rise of obesity in the United States over the past 25 years has resulted in an increase in the number of research studies published related to the causes, consequences, and possible solutions to the problem. Most would agree that obesity is a multi-dimensional problem that requires a range of solutions related to individual diet and activity, food and built environment, and public policy. Examination of complex relationships between food choice, time use patterns, sociodemographic characteristics and obesity has been limited by data availability and disciplinary focus. Using the theory of the production of health capital, this paper links empirical data from the Consumer Expenditure, Current Population, and American Time Use Surveys to provide estimates of the impacts of food expenditure and time use patterns on obesity in single female headed households of 31–50 years of age.
Potential Pitfall in the Assessment of Lung Cancer with FDG-PET/CT: Talc Pleurodesis Causes Intrathoracic Nodal FDG Avidity

Objective. Talc pleurodesis is a common procedure performed to treat complications related to lung cancer. The purpose of our study was to characterize any thoracic nodal findings on FDG PET/CT associated with prior talc pleurodesis. Materials and Methods. The electronic medical record identified 44 patients who underwent PET/CT between January 2006 and December 2010 and had a history of talc pleurodesis. For each exam, we evaluated the distribution pattern, size, and attenuation of intrathoracic lymph nodes and the associated standardized uptake value. Results. High-attenuation intrathoracic lymph nodes were noted in 11 patients (25%), and all had corresponding increased FDG uptake (range 2-9 mm). Involved nodal groups were anterior peridiaphragmatic (100%), paracardiac (45%), internal mammary (25%), and peri-IVC (18%) nodal stations. Seven of the 11 patients (63%) had involvement of multiple lymph nodal groups. Mean longitudinal PET/CT and standalone CT followups of 15 ± 11 months showed persistence of both high-attenuation and increased uptake at these sites, without increase in nodal size suggesting metastatic disease involvement. Conclusions. FDG avid, high-attenuation lymph nodes along the lymphatic drainage pathway for parietal pleura are a relatively common finding following talc pleurodesis and should not be mistaken for nodal metastases during the evaluation of patients with history of lung cancer.