cssi/SciSciGPT-SciSciNet huggingface dataset:
The Effect of Binary Cosolvent Systems (Glycerol-Sucrose Mixtures) on the Heat-Induced Gelation Mechanism of Bovine Serum Albumin

Summary The influence of cosolvent composition on the thermal denaturation and gelation of bovine serum albumin (BSA) has been studied. Cosolvent composition was varied by changing the ratio of glycerol to sucrose in 40 wt% cosolvent solutions containing BSA. Differential scanning calorimetry measurements on 0.5 wt% BSA solutions showed that the thermal denaturation temperature of the protein increased with increasing sucrose content. Temperature scanning dynamic shear rheology and turbidity measurements on 4 wt% BSA solutions showed that the gelation temperature and final gel strength increased with increasing sucrose concentration. These observations were attributed to the fact that sucrose was more effective than glycerol at increasing the thermal stability and attraction between globular BSA molecules through a steric exclusion effect. The molecular origin of these effects is the tendency for the system to minimize the contact area of the protein molecules with the surrounding cosolvent solution.
A New Solution to the Additive Constant Problem in Metric Multidimensional Scaling.

A new solution to the additive constant problem in metric multidimensional scaling is developed. This solution determines, for a given dimensionality, the additive constant and the resulting stimulus projections on the dimensions of a Euclidean space which minimize the sum of squares of discrepancies between the formal model for metric multidimensional scaling and the original data. A modification of Fletcher-Powell style functional iteration is used to compute solutions. A scale free index of the goodness of fit is developed to aid in selecting solutions of adequate dimensionality from multiple candidates.
Rethinking early Earth phosphorus geochemistry

Phosphorus is a key biologic element, and a prebiotic pathway leading to its incorporation into biomolecules has been difficult to ascertain. Most potentially prebiotic phosphorylation reactions have relied on orthophosphate as the source of phosphorus. It is suggested here that the geochemistry of phosphorus on the early Earth was instead controlled by reduced oxidation state phosphorus compounds such as phosphite (HPO32−), which are more soluble and reactive than orthophosphates. This reduced oxidation state phosphorus originated from extraterrestrial material that fell during the heavy bombardment period or was produced during impacts, and persisted in the mildly reducing atmosphere. This alternate view of early Earth phosphorus geochemistry provides an unexplored route to the formation of pertinent prebiotic phosphorus compounds, suggests a facile reaction pathway to condensed phosphates, and is consistent with the biochemical usage of reduced oxidation state phosphorus compounds in life today. Possible studies are suggested that may detect reduced oxidation state phosphorus compounds in ancient Archean rocks.
Stimulation of adrenergic development in neural crest cultures by a reconstituted basement membrane-like matrix is inhibited by agents that elevate cAMP.

Previous work (Maxwell and Forbes: Development 101:767–776, 1987) has shown that an overlay of reconstituted basement membrane-like (RBM) gel dramatically increased the number of catecholaminepositive (CA+) cells which differentiated in neural crest cultures. We report here that this increase was inhibited when cultures were grown for 7 days in the presence of agents that elevate cAMP, such as 8-bromo-cAMP and 3-isobutyl-1-methylxanthine. The action of 8-bromo-cAMP was dose dependent with a half-maximal effect at about 50 μM. The development of CA+ cells was dramatically reduced when 8-bromo-cAMP was present from days 0–4 in vitro, but was relatively unaffected if 8-bromo-cAMP was present from days 4–7 in vitro. The development of tyrosine hydroxylase immunoreactive cells was also inhibited by 8-bromo-cAMP. The addition of 8-bromo-cAMP increased the number of melanocytes and resulted in either no change or only modest reductions in the number of E/C8 and neurofilament immunoreactive cells, indiciting that the effect on CA+ cell ontogeny was selective. In contrast to the effectof 8-bromo-cAMP, addition of 8-bromo-cGMP did not inhibit CA+ cell development in the presence of the RBM gel nor did it stimulate CA+ cell development in the absence of the RBM gel overlay. Our results suggest that cAMP may be an important regulator of phenotypic expression in at least some neural crest cell lineages. In particular, these observations provide evidence that agents that elevate cAMP levels can act to prevent an essential part of the normal cellular response leading to the normal cellular response leading to the appearance of CA+ phenotype in neural crest cultures.
Nanobiotechnology: checking out the insides of cells.

A nanowire attached to an optical fibre can deliver payloads or light into specific compartments within a living cell, and also detect optical signals from subcellular regions with high spatial resolution.
Preliminary crystallographic study of a complex between an Fab of a monoclonal feline peritonitis virus neutralizing antibody and its anti-idiotypic Fab.

Abstract A complex between an Fab fragment of an E2 specific feline infectious peritonitis virus neutralizing antibody 730.1.4 and Fab fragment from an anti-idiotypic monoclonal antibody 409.5.3, was crystallized from ammonium sulfate using vapor diffusion methods. The complex crystals diffract to about 2·9 A resolution and are of orthorhombic space group P 21221 with a = 75·2 A, b = 80·6 A and c = 187·6 A. There are two Fab molecules, or one idiotype-anti-idiotype complex, comprising the asymmetric unit. The long 187·6 A c axis suggests that the long axis of the complex might lie along this direction. Although small and radiation-sensitive, crystals are suitable for three dimensional structural analysis.
Epic Lives and Monasticism in the Middle Ages, 800–1050

Introduction: saints, teachers, princes, and students 1. Forging sanctity: Hilduin of Saint-Denis and the epic Passio Dionysii 2. Glossing the imaginary: epic vitae in the classroom 3. Classical nightmares: Christian poets and the pagan past 4. Bishops, monks, and mother bees: an epic vita at the millennium 5. Mothers and daughters, affiliation and conflict in the lives of Rictrude and Euseba Conclusions: 'black seeds on a white field' Appendix 1. St Gallen, Stiftsbibliothek, cod. sang. 265 Appendix 2. Douai Bibliotheque municipale ms 849.
Vibrational frequencies and structural determination of cyanogen azide

Abstract The vibrational frequencies and corresponding normal mode assignments of cyanogen azide are examined theoretically using the Gaussian03 set of quantum chemistry codes. All normal modes were successfully assigned to one of seven types of motion predicted by a group theoretical analysis (N N stretch, N N stretch, N–C stretch, C N stretch, N N N bend, N N–C bend, and N–C N bend). Theoretical infrared and Raman intensities are reported. The molecular orbitals and bonding of cyanogen azide are examined.
Impact of anatomical subtype and medical comorbidities on hospitalizations in adults with single ventricle congenital heart disease.

Abstract Background Most patients with single ventricle congenital heart disease (SV) are now expected to survive to adulthood. Medical comorbidities are common in SV. Methods We used data from 43 pediatric hospitals in the 2004 to 2011 Pediatric Health Information System database to identify patients ≥18years of age admitted with International Classification of Diseases-9th Revision codes for a diagnosis of either hypoplastic left heart syndrome (HLHS), tricuspid atresia (TA) or common ventricle (CV). Primary (PD) and secondary diagnoses (SD), length of stay (LOS) and hospital charges were determined. Multilevel models were used to evaluate differences in demographics, diagnoses, and admission outcomes among the three subgroups (HLHS, TA, and CV). Interactions of charges with PD and admission year were examined using ANOVA. Results There were 801 SV patients with 1330 admissions during the study period. Mean age was 24.8±6.2years (55% male) and mean LOS was 6.8±11.3days. Total hospital charges were $135million with mean charge per admission of $101,131±205,808. The mean charge per day was $15,407±16,437. Hospital charges correlated with PD group (p Conclusions Hospitalization costs in adults with SV are significant and are impacted by comorbid medical conditions. Hospitalization rates for adults with SV are not increasing. Gastroenterologic comorbidities including protein-losing enteropathy (PLE) are common in HLHS.
A Non-Peshitta Jeremiah Citation by Aphrahat

The fourth century Syriac church father Aphrahat cites Jer. 31.31–32 in his Demonstrations. His citation is remarkable since it differs dramatically from the text of the OT Peshitta. This essay analyzes the citation and presents a solution. What looks at first blush like a citation of the Peshitta OT is in reality a blending of the Syriac NT citation of the OT and the OT Peshitta text. His use of Gen. 15.6 corroborates this method of OT citation.
Mixing behavior of 10-(perfluorohexyl)-decanol and DPPC.

Fluorocarbon alcohol such as 10-(perfluorohexyl)-decanol are of interest for novel pulmonary drug delivery approaches. The purpose of this study was to investigate the mixing behavior of 10-(perfluorohexyl)-decanol with dipalmitoylphosphatidylcholine (DPPC), the major component of lung surfactant as an aid in assessing usefulness for this and other biomedical applications. The impact of 10-(perfluorohexyl)-decanol on the phase transitions of DPPC bilayers fully hydrated with a 0.15 M sodium chloride solution were studied using differential scanning calorimetry (DSC). No peak corresponding to excess alcohol was observed. The fluorinated alcohol caused DPPC peak broadening, especially below XDPPC < 0.95, and elimination of the pretransition of DPPC at XDPPC ∼ 0.91. The onset of the main phase transition remains constant down to XDPPC ∼ 0.91, suggesting limited miscibility in the gel phase. Hydration of the 10-(perfluorohexyl)-decanol–DPPC mixtures with calcium chloride (2 mM) in place of sodium chloride did not alter the macroscopic phase behavior. In addition to the thermal properties, the miscibility of 10-(perfluorohexyl)-decanol in DPPC in monolayers at the air water interface was investigated on water, sodium chloride (0.15 M), calcium chloride (2 mM) or hydrochloric acid (pH 1.9) subphases. The concentration dependence of the onset pressure of the liquid-expanded to liquid condensed phase transition of DPPC showed a slight change with increasing mole fraction on all four subphases. The surface area-mole fraction diagrams of 10-(perfluorohexyl)-decanol and DPPC on water, sodium chloride and calcium chloride showed near ideal behavior with slight negative deviations at higher surface pressure. A more significant negative deviation was observed for the hydrochloric acid subphase. Overall, both the DSC and the monolayer studies suggest that 10-(perfluorohexyl)-decanol and DPPC are partially miscible in biological mono- and bilayers. The macroscopic phase behavior 10-(perfluorohexyl)-decanol–DPPC system is significantly different from the analogous hydrocarbon system, which is attributed to a less favorable packing of the partially fluorinated hydrophobic tails in the mono- and bilayer.
Linear time-invariant space-variant filters and the parabolic equation approximation

Abstract Wave propagation in a random, inhomogeneous ocean is treated as transmission through a linear, time-invariant, space-variant, random communication channel. Using the parabolic equation approximation of the Helmholtz wave equation, a random transfer function of the ocean volume is derived . The ocean volume is characterized by a three-dimensional random index of refraction which is decomposed into deterministic and random components. Two additional calculations are performed using the transfer function. The first involves the derivation of the equations for the random, output electrical signals at each element in a receive planar array of complex weighted point sources in terms of the frequency spectrum of the transmitted electrical signal, the transmit and receive arrays, and the transfer function of the ocean medium. The second involves the derivation of the coherence function.
SOME ELECTROCHEMICAL ASPECTS OF CORROSION OF STEEL IN CONCRETE.

Abstract Because of the variation in composition and steel surface conditions in steel-reinforced concrete samples immersed in sodium chloride solutions, Mcorr is a better indicator of corrosive behavior than the time of exposure. While it is true that for many samples, the longer the exposure time, the greater the probability of corrosion-product buildup, the corrosive behavior of individual samples selected on the basis of exposure time may give misleading results insofar as the mechanism by which steel goes from the passive to active state is concerned. Therefore, the value of Mcorr, when measured under the same conditions, is much more reflective of the corrosive behavior than the time of exposure to sodium chloride solutions.
Aortic Valve Interstitial Cell Viscoelasticity

Long term tissue-level durability of the aortic valve (AV) is maintained by the cell populations residing both in the interstitium and on the epithelium. Due to the dynamic environment in which the AV interstitial cells (AVICs) function, recent work has examined the mechano-dependent, biosynthetic and contractile response of these cells [1–4]. Many idealized assumptions have been made about mechanical properties [1, 4], ECM connectivity [2], and deformations that the AVICs undergo during diastole [3]. These assumptions include that the AVICs are elastic, homogenous materials that deformation in an affine sense with the tissue.Copyright © 2007 by ASME
Cardiac Neoplasms: Current Diagnosis, Pathology, and Therapy

Cardiac neoplasms remain enigmatic because of their rarity and protean clinical manifestations. Although surgery for benign cardiac neoplasms seems straightforward, certain difficulties in diagnosis and extirpation often exist. Newer diagnostic modalities including intraoperative transesophageal echocardiography seem promising and may provide better planning for the surgeon. Moreover, cardiac transplantation has provided relief for some patients with irresectable benign neoplasms. As ventricular arrhythmias may emanate from benign tumors, electrophysiologically guided extirpation may provide helpful control. Malignant cardiac tumors remain the true challenge, whether primary or metastatic, as little surgical or medical progress has resulted. This review examines nearly all diagnostic, pathological, histologic, and therapeutic aspects of benign and malignant cardiac tumors. Moreover, the various surgical approaches necessary for removal of resectable neoplasms are detailed.
Multiscale geometric modeling of macromolecules I: Cartesian representation

This paper focuses on the geometric modeling and computational algorithm development of biomolecular structures from two data sources: Protein Data Bank (PDB) and Electron Microscopy Data Bank (EMDB) in the Eulerian (or Cartesian) representation. Molecular surface (MS) contains non-smooth geometric singularities, such as cusps, tips and self-intersecting facets, which often lead to computational instabilities in molecular simulations, and violate the physical principle of surface free energy minimization. Variational multiscale surface definitions are proposed based on geometric flows and solvation analysis of biomolecular systems. Our approach leads to geometric and potential driven Laplace-Beltrami flows for biomolecular surface evolution and formation. The resulting surfaces are free of geometric singularities and minimize the total free energy of the biomolecular system. High order partial differential equation (PDE)-based nonlinear filters are employed for EMDB data processing. We show the efficacy of this approach in feature-preserving noise reduction. After the construction of protein multiresolution surfaces, we explore the analysis and characterization of surface morphology by using a variety of curvature definitions. Apart from the classical Gaussian curvature and mean curvature, maximum curvature, minimum curvature, shape index, and curvedness are also applied to macromolecular surface analysis for the first time. Our curvature analysis is uniquely coupled to the analysis of electrostatic surface potential, which is a by-product of our variational multiscale solvation models. As an expository investigation, we particularly emphasize the numerical algorithms and computational protocols for practical applications of the above multiscale geometric models. Such information may otherwise be scattered over the vast literature on this topic. Based on the curvature and electrostatic analysis from our multiresolution surfaces, we introduce a new concept, the polarized curvature, for the prediction of protein binding sites.
The use of mole-mapping diagrams to increase skin self-examination accuracy.

Background Monthly skin self-examination (SSE) is associated with reduced incidence of advanced melanoma, but SSE is prone to error in detecting early changes of melanoma. Objective We sought to improve SSE accuracy by requiring participants to complete a mole-mapping diagram. Methods After completing a baseline survey, participants received SSE instruction, had their backs digitally photographed, and half were randomized to complete a mole-mapping diagram. Some photographs were altered by adding an image of a 5-mm pigmented lesion. At follow-up, participants were asked to identify any changes introduced to their photographs. Results A total of 88 participants completed the study. In all, 33% (n = 15) of the control group (no diagram) and 52% (n = 22) of the intervention group (mole-mapping diagram) ( P = .06) gave accurate assessments. Analysis of only altered images indicated that the intervention group gave more accurate assessments (60% vs 33%, P = .01). Limitations This study was limited by sample size, only addressed lesions on the back, and did not involve actual melanomas in study participants. Conclusions Mole-mapping diagrams may improve SSE accuracy, and may be useful as a simple, cost-effective intervention in reducing melanoma mortality.
Selective partial reduction of quinolines: Hydrosilylation vs. transfer hydrogenation

Abstract Two mild and versatile catalytic routes give regioselective hydrogenation of the heterocyclic ring of quinoline derivatives avoiding the high pressures of hydrogen required in the conventional hydrogenation route. Hydrosilylation using H 3 SiPh and catalyzed by [Rh(nbd)(PPh 3 ) 2 ]PF 6 at room temperature gives dihydroquinoline, a product not obtainable via direct hydrogenation. Hydrosilylation of the C N bond of PhCH NPh is also observed under these conditions while PhCH CHPh is unreactive. Initial in situ disproportionation of phenylsilane to H 2 SiPh 2 and SiH 4 , catalyzed by the same catalyst, was required for substrate reduction, as SiH 4 proved to be the active reductant. No N -silyl intermediates were ever observed, hydrolysis presumably occurring in situ. This disproportionation reaction is of potential use in gaining access to silane (SiH 4 ), a material otherwise not readily available. In a separate approach, transfer hydrogenation from isopropanol using [Ir(cod)(NHC)PPh 3 ]BF 4 (NHC = 1-neopentyl-4- n -butyl triazole-5-ylidene) as catalyst exclusively produces the tetrahydro product.
Advances in Software for Faster Procedure and Lower Radiotracer Dose Myocardial Perfusion Imaging

Abstract The American Society of Nuclear Cardiology has recently published documents that encourage laboratories to take all the appropriate steps to greatly decrease patient radiation dose and has set the goal of 50% of all myocardial perfusion studies performed with an associated radiation exposure of 9 mSv by 2014. In the present work, a description of the major software techniques readily available to shorten procedure time and decrease injected activity is presented. Particularly new reconstruction methods and their ability to include means for resolution recovery and noise regularization are described. The use of these improved reconstruction algorithms results in a consistent reduction in acquisition time, injected activity and consequently in the radiation dose absorbed by the patient. The clinical implications to the use of these techniques are also described in terms of maintained and even improved study quality, accuracy and sensitivity for the detection of heart disease.
Text reference via Google Voice: a pilot study

Purpose – This paper aims to analyze data from a pilot study at one academic library using Google Voice for text message (SMS) reference. It also aims to analyze SMS reference question typology, compare question typology to other reference services, and analyze communication in the context of SMS reference.Design/methodology/approach – Analysis of all reference service models was conducted, including question typology. SMS transcripts were analyzed in the following areas: presence of a reference interview, evidence of a referral, number of librarian and patron texts, response time, and transaction duration.Findings – The number of SMS queries was lower than expected. Questions were primarily non‐research‐based or ready reference. The average number of texts per transaction was 7.5. With outliers removed, average response time was 9.5 minutes, and average transaction time was 53.2 minutes. Users appear to be regulating question difficulty.Research limitations/implications – Data collection occurred during ...
Optical studies of complexes of quinacrine with DNA and chromatin: implications for the fluorescence of cytological chromosome preparations.

The fluorescence and circular dichroism of quinacrine complexed with nucleic acids and chromatin were measured to estimate the relative magnitudes of factors influencing the fluorescence banding patterns of chromosomes stained with quinacrine or quinacrine mustard. DNA base composition can influence quinacrine fluorescence in at least two ways. The major effect, evident at low ratios of quinacrine to DNA, is a quenching of dye fluorescence, correlating with G-C composition. This may occur largely prior to relaxation of excited dye molecules. At higher dye/DNA saturations, which might exist in cytological chromosome preparations stained with high concentrations of quinacrine, energy transfer between dye molecules converts dyes bound near G-C base pairs into energy sinks. In contrast to its influence on quinacrine fluorescence, DNA base composition has very little effect on either quinacrine binding affinity or the circular dichroism of bound quinacrine molecules. The synthetic polynucleotides poly(dA-dT) and poly(dA)-poly(dT) have a similar effect on quinacrine fluorescence, but differ markedly in their affinity for quinacrine and in the circular dichroism changes associated with quinacrine binding. Quinacrine fluorescence intensity and lifetime are slightly less when bound to calf thymus chromatin than when bound to calf thymus DNA, and minor differences in circular dichroism between these complexes are observed. Chromosomal proteins probably affect the fluorescence of chromosomes stained with quinacrine, although this effect appears to be much less than that due to variations in DNA base composition. The fluorescence of cytological chromosome preparations may also be influenced by fixation effects and macroscopic variations in chromosome coiling.
Role of Nitric Oxide and Its Interaction With Superoxide in the Suppression of Cardiac Muscle Mitochondrial Respiration Involvement in Response to Hypoxia/Reoxygenation

Background Nitric oxide (NO); superoxide anion (O2.d−); the reaction product of NO with O2.d−, peroxynitrite (ONOO−); and ischemia/reperfusion have all been reported to inhibit respiration in isolated mitochondria. However, the specific species involved in the inhibition of respiration in intact tissues are poorly understood. Methods and Results O2 consumption in isolated cardiac muscle from bovine calf hearts was quantified by use of a Clark-type electrode. Exogenous and endogenous sources of NO, from S-nitroso-N-acetylpenicillamine (SNAP) and bradykinin or carbachol, reversibly inhibited respiration, whereas the O2.− releasing agent, pyrogallol (PG), inhibited respiration in a manner that was only partially reversed when examined 15 minutes after the removal of PG. The generation of ONOO− with SNAP+PG caused a potentiation of the O2.−-elicited inhibition of respiration when examined 15 minutes after the removal of the ONOO− generating system. Tiron (a scavenger of O2.−) did not alter the actions of SNAP...
Does Chronic Treatment with Calcium Entry Blocking Drugs Reduce Perioperative Myocardial Ischemia

To examine the role of chronic calcium entry blocking drug administration on perioperative myocardial ischemia and, specifically, the frequency of hemodynamically unrelated ischemia, the authors studied 444 patients undergoing coronary artery bypass operations. Before induction of anesthesia, 119 pa
FLUID THEORY OF PLASMA DOUBLE-LAYERS

A double-layer consists of two adjacent, oppositely-charged space-charge layers, and may occur near a material boundary, or within the plasma volume (See [1]-[3] for reviews of double-layer phenomena in laboratory and space plasmas). Here, we shall analyze a steady-state double-layer separating two plasmas of different densities and temperatures, and relate its length and potential drop to the plasma parameters. Several theoretical models have treated the double-layer as a region of high electric field and monotonic potential variation. The total potential drop is generally taken to be larger than the plasma thermal energy, and the electric field is confined to the double-layer, implying that the charge variation integrates to zero. Cold plasma, fluid, and kinetic theory approaches have been discussed [2].
Metal Flow in Two-Die Swaging

A study of materials subjected to reductions in area by two-die swaging shows that non-uniform hardening occurs. The amount of cold work strengthening on the surface is the same as that for a similar reduction in area by cold rolling. The center hardness, however, is significantly greater. Cracks at the center of specimens are frequently observed. These effects are attributed to redundant working since successive blows strike new areas around the periphery but every blow affects the center.
The Effect of Diet and Alcohol on the Development of Folate Deficiency in the Rat

Summary. Studies of the rate of depletion of serum and tissue methylated and nonmethylated folates were carried out in rats maintained for long periods on either a folate deficient (sucrose-water/sulphathiazole) diet or a deficient diet plus high alcohol intake. By means of implantation of a feeding gastrostomy tube, it was possible to sustain constant blood ethanol levels of between 50 and 300 mg/dl for 3–4 weeks with relatively normal calorie intake and without death of the animal. Using this animal model, which closely resembles severe alcoholism in man, a very rapid depression in serum 5-methyl tetrahydrofolate was observed similar to that reported in alcoholic man. At the same time, release of folates from liver stores was unimpaired by alcohol ingestion. Liver folate store depletion rates were identical for alcoholic and folate starved animals. The explanation for the sudden alcohol suppression of serum folate levels must, therefore, be sought at a point in the internal metabolic sequences of folate other than the delivery of folate stores to plasma.
High school environments and girls' interest in computer science

This paper presents a brief literature review of the involvement of women in computer science, of high school computer science curricula, and of an increasing interest in single-sex education. A study was conducted to determine if the high school environment is a factor in encouraging girls' interest in and attitude toward computers. A description of the study and its results are discussed.
Effects of acute and chronic administration of marijuana extract on the rat electrocorticogram.

Abstract This study was designed to examine the effects of acutely and chronically administered marijuana extract distillate (17.1 % Δ9-tetrahydrocannabinol) on the rat electrocorticogram. Electrocorticograms were recorded from the parietal cortex during 2 1 2 -hr sessions and were quantified by voltage integration. Single oral doses of marijuana extract distillate containing 10, 20, or 40 mg/kg Δ9-tetrahydrocannabinol produced an overall decrease in integrated voltage, a decrease in the amplitude of low voltage activity, and the appearance of high voltage “spindle-like” activity. Similar electrocorticographic changes were observed after i.p. and i.v. marijuana extract distillate as well as after 95% pure Δ9-tetrahydrocannabinol given orally. The marijuana extract distillate effect on integrated voltage diminished gradually with daily treatment so that after 5–12 doses the integrated voltage was no longer significantly lower than the pre-drug placebo control. After 3–5 days of administration the “spindle-like” activity reached a maximum frequency of occurrence which was maintained during periods of treatment lasting as long as 35 days. Upon termination of chronic, daily marijuana extract distillate treatment a rebound increase in integrated voltage was observed. No tolerance developed to the effect of marijuana extract distillate on integrated electrocorticogram voltage when the drug was administered only once a week. This investigation clearly demonstrated that tolerance develops to certain, but not all, electrocorticographic effects of marijuana in the rat. The development of tolerance is dependent upon dosage interval. Furthermore, a rebound change in electrocorticogram voltage is observed upon termination of chronic, daily treatment.
Trapping the nematode on a micro chip for the future of science.

At the basis of neuroscience is the correlation between behavior and neural signals. This relationship is studied using a variety of techniques, including fluorescent intensity measurements of genetically encoded calcium indicators. The simple structure and conservation of some basic developmental pathways between vertebrates and Caenorhabditis elegans makes it an ideal model for studies employing this technique, but it has been difficult to apply neural stimuli in a controlled way to such a small organism. New microfabrication techniques allow the creation of “worm traps” via a combination of lithography and microfluidic regulation. These micro-scale devices have made possible the immobilization of nematodes in the absence of glue (which could affect the worms’ neural activity), in addition to offering more control over the application and removal of stimuli than was possible in previous experimental setups. Chronis et al. link an increase in AVA (a type of motor neurons formed by bilaterally symmetric interneuron pairs) neural activity to the initiation of anterior-traveling body waves, and observed an increase in ASH (a type of sensory neurons responsible for a wide range of avoidance behaviors in response to chemical and physical stimulations) neural activity in response to stimulation by high osmotic strength solutions. The microfabrication developments described can be combined with recent advances in the biological sciences, in particular the developmental embryology, to yield solutions to important problems, such as the detection of low concentration substrates and the analysis of homeostasis and embryonic development.
Teaching and Learning in Nanjing: Community, Communities, and Politics in an Overseas Program.

ABSTRACT One of the environments in which political science faculty most directly face issues of community, communities, and politics is when they find themselves teaching in programs abroad. The rigors of international teaching force faculty to confront issues of community identity, assumptions about political orientation, and presumptions about how communities interact that often remain unstated or unexplored at home institutions in the United States. In this paper, we will explore these matters based on our experiences teaching in the Johns Hopkins University-Nanjing University Center for Chinese and American Studies during the late 1990s. The Hopkins-Nanjing Center brings together Chinese and international (mainly American) graduate students in a unique living-learning environment. Chinese students take graduate-level course work in political science, American history, economics, and ESL in English from visiting American faculty members, while international students take analogous classes in Chinese f...
Line positions and strengths of 16O12C18O, 18O12C18O and 17O12C18O between 2200 and 7000 cm−1

Abstract Line positions and strengths of 16O12C18O (628), 18O12C18O (828) and 17O12C18O (728) were measured between 2200 and 7000 cm−1 using 22 near infrared (NIR) absorption spectra recorded at 0.01–0.013 cm−1 resolution with the McMath–Pierce Fourier transform spectrometer located at the National Solar Observatory on Kitt Peak, Arizona. These data were obtained at room temperature using absorption cells with optical path lengths ranging from 2.4 to 385 m; the cells were filled with natural and 18O-enriched samples of CO2 at pressures ranging from 0.54 to 252 torr. The observed line positions were analyzed to obtain the upper state band centers and rotational constants for 17 bands of 16O12C18O, 19 bands of 18O12C18O and 8 bands of 17O12C18O. The majority of the 18O12C18O and 17O12C18O bands were measured for the first time. In addition, the rotational constants for the lower states 00001, 01101e and 01101f were derived for all three species using the method of combination differences in which the averaged values obtained from the line positions of two or more bands were least-squares-fitted. Rovibrational parameters were also obtained for the 02201e, 02201f, 10002 and 10001 states of 18O12C18O. The line position analysis revealed that transitions of the levels 38 ⩽ J′ ⩽ 46 of the 11111f ← 01101f band of 18O12C18O are perturbed. Perturbed transitions were also observed for the 12212 ← 02201 band and in the high-J transitions (J′ ⩾ 49) of the 20012 ← 00001 band of 18O12C18O. Band strengths and Herman–Wallis-like F-factor coefficients were determined for 21 bands of 16O12C18O, 25 bands of 18O12C18O and 8 bands of 17O12C18O from least-squares fits to more than 3700 measured transition intensities; band strengths and line positions for 34 of these bands were obtained for the first time.
Peptic ulcers in infancy and childhood

Summary Seven cases of duodenal and one of gastric ulcers in children from 2 days to 11 years of age have been reported. One case was remarkable because of the association of ulcer with possible rhubarb poisoning. Two cases of apparently healed ulcer are included.
Basra dates. Relationship between ripening and sugar content of twelve varieties

The predominant sugar in the early stages of development of twelve varieties of dates grown in Iraq is sucrose; as ripening continues, the sucrose diminishes and in ten varieties ripe dates contain no sucrose; ripe dates of the remaining varieties examined contain small amounts of sucrose. A marked difference in composition exists between the Deglet Noor variety of date when grown in U.S.A. and the twelve varieties examined in Iraq as the former type contains, when fully ripe, a substantial proportion of sucrose.
Factors affecting nest choice by Pekin ducks

Abstract To encourage nest use in breeder poultry flocks, it is important that nest boxes are attractive. Few studies have evaluated factors affecting nest attractiveness to ducks. We assessed the effects of nest box experience (Experiments 1 and 2) and features of nests, including degree of enclosure (Experiments 1 and 2) and the presence of an egg (Experiment 3), on nest site selection by sexually mature Pekin ducks. The hens were tested individually in pens containing different nest box choices. Nest preferences were determined based on the locations of 14 successively laid eggs. Ducks in Experiment 1 were provided with nest box access prior to the onset of lay (20 weeks of age, EXP group, N = 12) or at the time of preference testing (35 weeks of age, DELAYED-EXP group, N = 12). Delaying nest box access by 15 weeks did not significantly affect the proportion of eggs laid in nest boxes rather than on the floor ( P = 0.40). Regardless of experience ducks laid more than 66% of their eggs in nest boxes offering a higher degree of enclosure. Ducks in Experiment 2 were reared with either open-top (OP, N = 12) or closed-top (CL, N = 12) boxes. Regardless of rearing condition, ducks preferred boxes with the highest level of enclosure offered. Ducks laid twice the expected proportion (25%) of eggs in CL boxes with curtains ( P = 0.0004). CL boxes without curtains were used as predicted by chance, 25% ( P = 0.746), while OP boxes with ( P = 0.009) and without ( P = 0.015) curtains each contained only half the expected number of eggs. Ducks in Experiment 3 were provided with two nest boxes, one of which contained the egg laid the previous day. Each day, the newly laid egg was marked and either placed back in the nest box where it was found (HANDLED, N = 12) or moved into the adjacent nest box (MOVED, N = 12). Ducks in HANDLED and MOVED laid 97.6% and 79.8%, respectively, of their eggs in boxes containing the previous day's egg. While ducks in HANDLED were consistent in their choice throughout the test, those in MOVED developed the preference over time ( P = 0.039), suggesting that the preference for laying in a nest containing an egg may be influenced by experience. These results indicate that nest box enclosure and the presence of an egg are important in determining the nesting choices of Pekin ducks. Incorporating these features into nest boxes may be useful for increasing consistency of nest use in breeder duck flocks.
Observations on the distribution of PCBs in the deepwater sediments of the Gulf of Maine

Abstract Nineteen stations were occupied in the deeper regions of the Gulf of Maine to determine the geographic extent of the PCB contamination reported from recent inshore surveys. Detectable levels of PCBs were found in all 94 samples in concentrations ranging from trace amounts to 0.13 ppm (dry wt). The complex topography of the Gulf of Maine required the subdivision of the Gulf into major basin regions for proper data analysis and interpretation. Two of the three major basins, Jordan and Georges, appeared to be depositional areas for PCBs. No significant relationships existed between PCB concentration and either TOC or depth in Wilkinson Basin, however, which is located in the western Gulf of Maine closer to presumed sources.
Characterization of Convection Patterns During the Solidification Process Using Particle Image Velocimetry

This experimental study focused mainly on the solidification of a binary mixture of ammonium chloride and water (NH4 Cl-H2 O) in a differentially heated cavity. One vertical wall is cooled at temperature TC , and the opposite vertical wall is kept at constant temperature TH = +20°C. The effect on the solidification process of the initial concentration of ammonium chloride and cooling conditions is examined. Particle image velocimetry (PIV) is used for the visualization of the dynamic field during the solidification process. The temperature distribution at discrete locations in the solution and on the vertical cooling wall was monitored using thermocouples. The convection flow patterns, the ice thickness, and the temperature distribution were obtained for various initial concentrations of ammonium chloride ranging from 0wt% to 20wt% (sub-eutectic and near-eutectic growth). The convection patterns obtained for different initial concentrations showed significant differences. The results showed that the process of solidification is slower with an increase in the initial concentration levels of the binary solution. The ice growth rate was almost double at the bottom of the cavity.Copyright © 2003 by ASME
Bäcklund transformation for two-dimensional nonlinear evolution equations and the decomposition theorem

Abstract The simplest Backlund transformations are derived for matrix spectral problems associated with the Dirac equation. Decomposition theorems reducing equations of the nonlinear Schrodinger type to the common action of commuting generalized Toda lattice flows are presented.
ENVIRONMENTAL DEGRADATION, ENVIRONMENTAL SUSTAINABILITY, AND OVERURBANIZATION IN THE DEVELOPING WORLD: A QUANTITATIVE, CROSS-NATIONAL ANALYSIS

This is the first quantitative, cross-national study that incorporates predictors designed to test hypotheses linking overurbaniza- tion to environmentally induced migration. The study is based on a sample of fifty-eight developing countries using lagged dependent variable panel regression. Our major findings are quite clear with respect to newer rural- push and urban-pull arguments that developing countries suffering from various forms of environmental degradation are prone to overurbanization. Deforestation exerts a positive and significant effect on overurbanization, whereas environmental sustainability exerts a negative and significant effect on overurbanization. In addition, our results support hypotheses derived from the political modernization perspective that civil society and demo- cratic regimes help to reduce overurbanization, as well as hypotheses sug- gested by neo-Malthusian theory that high levels of population growth contribute to high levels of overurbanization. We also find support for depen- dency theory in that transnational economic linkages based on multinational corporations and international lending institutions foster increased over- urbanization in the developing world.
Inhibition of ethanol induced ethane exhalation by carcinogenic pretreatment of rats 12 months earlier

Abstract The exhalation of ethane was used as a measure of in vivo lipid peroxidation in rats treated with the hepatocarcinogen diethylnitrosamine followed by 2-acetylaminofluorene (AAF), and carbon tetrachloride, and subsequently fed a liquid diet containing 7 % ethanol for 12 months. The other groups consisted of animals treated with methylbenzylnitrosamine (MBN), an esophageal carcinogen, or non-carcinogen pretreated animals with or without 7% ethanol feeding. Ethane production was increased in rats consuming ethanol irrespective of their pretreatment with MBN. In sharp contrast, the ethanol-induced increase of ethane production was absent in rats given the hepatocarcinogenic regime. Our results strengthen recent observations indicating decreased susceptibility of tumor cells to lipid peroxidation. In addition, they confirm the debated concept that there is increased lipid peroxidation following ethanol consumption.
Bloch Electrons in Magnetic Fields. Rationality, Irrationality, Degeneracy

The “irrational” equations for determining the energy eigenvalues developed earlier are studied. It is shown that, for rational fields, they can be transformed into the “rational” equations which are generally preferred. The two energy spectra are therefore the same, and there exists no conflict. Further, the question of infinite degeneracy familiar from the Landau functions is taken up. It was established earlier that as long as the field is irrational, this degeneracy is also present for Bloch electrons; now a criterion is developed for the condition under which this degeneracy may be lifted. The criterion comes out to be a rationality condition on the field: it differs in general from the usual (Brown) rationality; it is called “green” rationality. Es werden die fruher abgeleiteten „irrationalen” Gleichnngen fur das Energiespektrum betrachtet und es wird gezeigt, das sie fur rationale “Felder in die rationalen” Gleichungen transformiert werden konnen. Die Spektren stimmen deshalb uberein und es besteht kein Widerspruch zwischen den Gleichungen. Weiter wird die Frage einer unendlichen Entartung behandelt, wie sie von den freien Landaufunktionen bekannt ist; es wurde fruher gezeigt, das diese Entartung fur irrationale Felder auch im Gitter vorhanden ist, jetzt wird eine Bedingung angegeben, unter der sie aufgehoben ist. Die Bedingung ist wieder eine Rationalitsbedingung fur das Feld, doch ist sie im allgemeinen von der von Brown diskutierten Rationalitat verschieden und soll deshalb als „grune” Rationalitat bezeichnet werden.
Growth Strains and Stress Relaxation in Alumina Scales during High Temperature Oxidation

A novel X-ray technique was used, exploiting synchrotron radiation at the Advanced Photon Source at Argonne National Laboratory, to investigate the growth stresses in {alpha}-Al{sub 2}O{sub 3}. In-situ measurements of Debye-Scherrer diffraction patterns from the scale were recorded during oxidation and cooling, and the elliptical distortion of the diffraction rings was analyzed to yield the in-plane strain. Fe-28Al, Fe-40Al, Fe-40Al-0.2Hf, Fe-20Cr-10Al and Ni-50Al (at. %) were studied. Data were acquired in air at temperatures between 950-1100 C and during cool down. In all cases, the steady stage growth strain was relatively low (<0.1%) and was either tensile or compressive depending on the alloy. A higher tensile strain often existed during the initial oxidation period when transition alumina was present. Thermal stresses imposed on NiAl by reducing the sample temperature to 950 C for a period of time showed noticeable stress relaxation by creep. Different degrees of relaxation were also found during cooling depending on alloy composition and scale microstructure. On all Fe-based alloys, the first formed {alpha}-Al{sub 2}O{sub 3} was highly textured with the degree of texture decreasing with further oxidation. The relationships between stress development, scale wrinkling, oxide phase changes, and the effect of reactive element addition on growthmore » stresses are discussed. Results are compared with other reports of growth stresses in Al{sub 2}O{sub 3} scales.« less
Body mass index and marijuana use.

Though marijuana has been reported to stimulate appetite, we searched for a correlation between obesity and decreased marijuana use. We examined charts of all females referred for morbid obesity/weight management in a 12-month period. BMI and substance use data were collected from 297 charts. While 29% of the sample with BMI 50 used marijuana in the past year. Linear regression revealed a negative correlation between BMI group and percent marijuana use (R-squared = 0.96; P = 0.0173). These findings provide support for overeating as competition for drugs and alcohol in brain reward sites.
Reverse Phase HPLC Determination of Azq in Biological Fluids

Abstract A sensitive and specific reverse phase HPLC method employing a simple sample preparation procedure and utilizing an internal standard was developed to measure the new antitumor agent AZQ in biological fluids. A single chloroform extraction gave drug recoveries of greater than 88% from plasma, urine and CSF in the range of expected physiological concentrations (20–800 ng/ml). Isocratic reverse phase HPLC with UV detection at 340 nm resulted in a limit of quantisation of 5 ng/ml although smaller amounts of the drug could be detected. This assay was successfully applied to determine the single dose plasma pharmacokinetics of AZQ in rats. The potential of this method for determining AZQ disposition and pharmacokinetics in human subjects was demonstrated by analysis of patient CSF.