cssi/SciSciGPT-SciSciNet huggingface dataset:
Increased sensitivity of the microsomal oxidation of ethanol to inhibition by pyrazole and 4-methylpyrazole after chronic ethanol treatment

Abstract Pyrazole and 4-methylpyrazole, inhibitors of the oxidation of ethanol by alcohol dehydrogenase, also inhibit microsomal metabolism of ethanol. The inhibitory effectiveness of these agents was increased in microsomes isolated from rats treated chronically with ethanol as compared to microsomes from pair-fed controls or from rats treated with other cytochrome P-450 inducers such as phenobarbital or 3-methylcholanthrene. Pyrazole and 4-methylpyrazole produced type II binding spectra with all the microsomal preparations. However, there was an increased affinity (lower K s value) for these agents by the microsomes from the ethanol-fed rats. A correlation between K s values and inhibitory effectiveness against ethanol oxidation by the various microsomal preparations could be observed. This suggests that an increase in affinity, which may reflect the induction of an alcohol-preferring isozyme of cytochrome P-450, is responsible for the increased inhibitory effectiveness of pyrazole and 4-methylpyrazole towards ethanol oxidation by microsomes after chronic ethanol treatment. One difference between pyrazole and 4-methylpyrazole was the increased affinity and inhibitory effectiveness of the latter but not the former with microsomes from rats treated with 3-methylcholanthrene. This could be due to the ability of 4-methylpyrazole, compared to pyrazole, to interact with and induce several isozymes of cytochrome P-450. Pyrazole and 4-methylpyrazole are often utilized to evaluate ethanol metabolism by alcoholdehydrogenase-dependent and -independent pathways. However, the sensitivity of microsomal ethanol oxidation to inhibition by these agents, especially after chronic ethanol treatment, would suggest that their use in this regard is complex and could tend to underestimate the contribution of the microsomal pathway towards the metabolic tolerance found after ethanol treatment.
Role of metalloporphyrin core metals in the mediated reductive dechlorination of tetrachloroethylene

A promising approach to abiotically dechlorinate a variety of chlorinated organic contaminants under reducing conditions is to utilize porphyrins or other tetrapyrrole macrocycles as electron transfer mediators/shuttles for catalyzing their reduction. In this study, various experimental approaches were used to elucidate the role of porphyrin core metals in the reductive dechlorination of tetrachloroethylene (PCE). The importance of specific core metals for the reactivity of a porphyrin and its mediated reaction mechanisms was demonstrated by inserting different metals into metallo tetrakis (N-methyl-4-4 pyridiniumyl) porphyrin (TMPyP). No PCE dechlorination was observed when the free-base (i.e., no core metal) and iron core metal forms of TMPyP were utilized. When using nickel or cobalt TMPyP, reductive dechlorination of PCE occurred but appeared to follow different pathways for the two metals based on product analyses. Physical (e.g., steric) considerations suggest that direct contact between a porphyrin core metal and PCE may be limited and therefore that the entire metalloporphyrin molecule should be viewed as a functional system in which the organic macrocycle has an active part in reductive dechlorination reactions. This view is supported by the fact that slight changes in the functional groups on a porphyrin macrocycle, particularly those far removed from the core metal itself, greatly affected the reactivity and mechanism of the porphyrin. Solution conditions also had a major effect on porphyrin reactivities, to the extent that a nonreactive metalloporphyrin could be activated merely by adjusting the pH of the solution or by adding a small amount of cosolvent. The collective results of this study suggest that fine tuning of naturally occurring metalloporphyrin complexes and/or their environments can enhance the catalyzed detoxification of chlorinated contaminants in many natural and engineered environmental systems.
THE EFFECT OF ALA AND RADIATION ON PORPHYRIN/HEME BIOSYNTHESIS IN ENDOTHELIAL CELLS

To study porphyrin biosynthesis in human microvascular endothelial cells, HMEC-1 cells, a transformed human microvascular endothelial cell line, were incubated with 5-aminolevulinic acid (ALA), the precursor of endogenous porphyrins, and porphyrin accumulation was measured spectro-fluorometrically. The HMEC-1 cells accumulated porphyrin in a concentration-related and a time-dependent fashion. Protoporphyrin was the predominant porphyrin accumulated in the cells. The effect of light on protoporphyrin accumulation was evaluated by exposing the ALA-loaded HMEC-1 cells to ultraviolet-A (UVA) and blue light, followed by another incubation with ALA for 2-24 h. Enhancement of protoporphyrin accumulation in irradiated HMEC-1 cells was observed 2-24 h after irradiation, which was associated with a decrease in ferrochelatase protein and activity. Porphyrin accumulation from ALA after irradiation was significantly decreased when catalase (750-3000 U/mL, 29.3-44.3% suppression) or superoxide dismutase (270 U/mL, 36.4% suppression) was present during irradiation. These data demonstrate that HMEC-1 cells were capable of porphyrin biosynthesis, and that exposure of protoporphyrin-containing HMEC-1 cells to UVA and blue light, which includes the Soret band spectrum, decreased the ferrochelatase activity and its protein. These changes were mediated, at least in part, by reactive oxygen species.
Pacification or Contestation? The Role of Discourse in Agricultural Policy1

L'A. examine de facon critique la these defendue par Leland L. Glenna dans son article : «Systemic Constraints to Ecological Well-being: The Case of the 1985 Food Security Act» publie en 1999. L'A. estime que contrairement aux declarations de Glenna, le processus de prise de decision au sein du United States Department of Agriculture et de l'Environmental Protection Agency ne suit pas une demarche relevant de la rationalite instrumentale. Il decrit de quelle maniere la Public Trust Doctrine, qui fixe un certain nombre de principes destines a assurer la protection des littoraux et des voies navigables, est appliquee. Il s'interroge quant au niveau d'autonomie dont dispose l'Etat federal americain en matiere d'agriculture et de protection de l'environnement vis-a-vis des groupes de pressions economiques.
Association of hepatitis B surface antigen and core antibody with acquisition and manifestations of human immunodeficiency virus type 1 (HIV-1) infection.

We examined the associations between seropositivity for hepatitis B virus (HBV) with the presence or development of antibodies to human immunodeficiency virus (HIV-1) and with HIV-1 induced T-helper lymphocyte deficiency or acquired immunodeficiency syndrome (AIDS). Serologic data on HBV and HIV-1, cytometric enumeration of CD4+ lymphocytes, clinical events (AIDS by Centers for Disease Control criteria) and hepatitis B vaccination histories were available on 4,498 homosexual participants in the Multicenter AIDS Cohort Study, Men were classified as to previous infection with HBV and prevalent or incident infection with HIV-1. Although there was an association between seropositivity for HBV infection and HIV-1 infection at enrollment (odds ratios anti-HBc 2.6; HBsAg 4.2), the relation between HBV seropositivity and subsequent seroconversion to HIV-1 was weaker (odds ratios 1.3 and 1.6). HIV-1 seroconversion was also associated with a history of certain other sexually transmitted diseases, but predisposing s...
Isolation of Leclercia adecarboxylata from a wound infection after exposure to hurricane-related floodwater

A man in his early 80s presented to our emergency department with painless redness and swelling in his right leg. One week prior, he cleaned up floodwater in his basement after Hurricane Irene passed the Mid-Atlantic region of the USA in August 2011. Physical examination included large purple bullae and raised concern for necrotising fasciitis. Wound culture revealed a polymicrobial infection including Leclercia adecarboxylata.
Changes in leaf phosphate status have only small effects on the photochemical apparatus of sugar beet leaves

Abstract The effects of orthophosphate (Pi) on the structure and function of thylakoid membranes was investigated by monitoring changes in thylakoid polypeptides, pigment-proteins, cytochromes (Cyt), atrazine-binding sites, leaf fluorescence characteristics, photosynthesis quantum yield and electron transport (including Cyt f dark reduction) in leaves of sugar beet (Beta vulgaris L. cv. F58-554H1) plants cultured hydroponically with different levels of Pi supply. Low-P treatment (i.e. low external Pi supply) decreased soluble leaf phosphorus (P) by 78% and total plant dry matter by 77%, and decreased light-saturated photosynthetic CO2 fixation by 32%. The results show that low-P treatment had only minor effects on thylakoid membrane composition and function. There was some evidence that low-P increased the amounts of photosystem (PS) I and light harvesting chlorophyll-protein complexes and of the Cyt f and b 563 , relative to the amounts of PS II reaction center complex, the number of atrazine binding sites and Cyt b 559 . Low-P treatment had very little effect, if any, on photosynthetic quantum yield and small effects on chlorophyll fluorescence.
Is there a link between the extracranial venous system and central nervous system pathology

The extracranial venous system is complex and variable between individuals. Until recently, these variations were acknowledged as developmental variants and were not considered pathological findings. However, in the last decade, the presence and severity of uni- or bi-lateral jugular venous reflux (JVR) was linked to several central nervous system (CNS) disorders such as transient global amnesia, transient monocular blindness, cough headache, primary exertional headache and, most recently, to Alzheimer's disease. The most recent introduction of a composite criteria-based vascular condition named chronic cerebrospinal venous insufficiency (CCSVI), which was originally linked to multiple sclerosis, increased the interest in better understanding the role of the extracranial venous system in the pathophysiology of CNS disorders. The ultimate cause-consequence relationship between these conditions and CNS disorders has not been firmly established and further research is needed. The purpose of this article collection in BMC Medicine and BMC Neurology is to synthesize current concepts and most recent findings concerning the evaluation, etiology, pathophysiology and clinical relevance of the potential involvement of the extracranial venous system in the pathology of multiple CNS disorders and in aging.
Elevated temperature combined erosion-corrosion of steels

Abstract The effects of erodent particle size and elevated temperatures on the combined erosion-corrosion behavior of a series of chromium-containing steels were investigated in an oxidizing gas stream. It was determined that corrosion was the dominant mechanism at all test conditions for all alloys. Particle impacts enhanced the growth rate of multilayered iron oxide and Fe-Cr oxide spinel scales and markedly changed the morphology of the scale surface and the thickness of the various scale layers.
Balance-equation analysis of linear and nonlinear electronic transport in quasi-two-dimensional quantum-well superlattices.

A non-Boltzmann balance-equation approach to linear and nonlinear dc steady-state electronic transport in a type-I superlattice (which is composed of infinitely many periodically arranged finite-width quantum wells) is developed in the presence of an electric field parallel to the superlattice planes. The method is based on a separation of the parallel motion of the center of mass from the relative motion of the electron system. The Coulomb interactions between intralayer and interlayer carriers are naturally built in via the electron density-density correlation function of the superlattice system. The force and energy balance equations obtained are applied to the calculation of the Ohmic mobilities limited by remote and background impurity scatterings and by acoustic and polar optical-phonon scatterings in GaAs-${\mathrm{Al}}_{\mathrm{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathrm{x}}$As superlattices. The nonlinear mobility and electron temperature are numerically calculated as functions of drift velocity, including all the above-mentioned scattering mechanisms and the full effect of carrier-carrier Coulomb interaction within the framework of the random-phase approximation. The dependence of transport on the geometrical parameters of the superlattice is discussed.
E-graffiti: evaluating real-world use of a context-aware system

Abstract Much of the previous research in context-aware computing has sought to find a workable definition of context and to develop systems that could detect and interpret contextual characteristics of an user environment. However, less time has been spent studying the usability of these types of systems. This was the goal of our project. E-graffiti is a context-aware application that detects the user's location on a college campus and displays text notes to the user based on their location. Additionally, it allows them to create notes that they can associate with a specific location. We released E-graffiti to 57 students who were using laptops that could access the campus wireless network. Their use of E-graffiti was logged in a remote database and they were also required to fill out a questionnaire towards the end of the semester. The lessons learned from the evaluation of E-graffiti point to themes other designers of ubiquitous and context-aware applications may need to address in designing their own systems. Some of the issues that emerged in the evaluation stage included difficulties with a misleading conceptual model, lack of use due to the reliance on explicit user input, the need for a highly relevant contextual focus, and the potential benefits of rapid, ongoing prototype development in tandem with user evaluation.
Development and Optimization of the Electrostatic Precipitator with Superhydrophobic Surface (EPSS) Mark II for Collection of Bioaerosols

We recently developed an electrostatic collector for bioaerosols that electrostatically deposits biological particles onto a 3.2 mm electrode covered by a superhydrophobic substance. The deposited biological particles are removed and collected by rolling water droplets (20 or 40 microliter) which results in high concentration rates. The collector has been improved further by integrating it with an electrical charger. Here, we describe the development and optimization of the charger and collection chamber, while maximizing collection efficiency and minimizing particle loss. The resulting sampler is made of static dissipative material (e.g., Delrin), is shaped as a closed half cylinder, and is integrated with a charger. The sampler's round top section contains eight carbon fiber brushes (ion sources to charge particles), while its flat bottom section holds a rectangular collection electrode (254 × 3.2 mm) made of pressed carbon fiber and coated with a superhydrophobic material.The optimized configuration of...
An analysis of the type I error in the one sample Student t-test

In the one-sample Student t-test, the occurrence of a type-I error is dependent on the estimates of the mean and standard deviation for a fixed sample size, n. The statistic can achieve significance either by the sample mean being too different from the hypothesized mean or by the sample standard deviation being too small. The critical region is partitioned to determine the characteristics of samples in the critical region, assuming the null hypothesis is true. As might be conjectured from the use of the t-statistic, mis-estimation of the mean is shown to be the predominant characteristic of samples in the critical region for sample sizes larger than 20 and significance level greater than 0.01. Underestimation of the variance, unless accompanied by a misestimation of the mean, is a far less frequent characteristic of critical region samples.
Evaluation of litho printability of DRAM contact hole patterns with various programmed defects

As the photomask design rules continue to shrink towards 45nm and below, the defect classification criteria is becoming more challenging to be set accurately. Pattern fidelity issues and masks defects that were once considered insignificant or merely nuisances are now yield-limiting. On the other hand, there are still cases of small defects captured during reticle inspection but will not print on the wafer. In addition, in a production setting environment it is critical to ascertain quickly and efficiently the true lithographic effect of reticle defects in order to avoid yield and cycle time impacts. As a starting point, it is best to inspect the reticle at the highest sensitivity to find all defects and anomalies. From there, fast and efficient means to sort and prioritize defects are necessary for inspection operators' and engineers' convenience. Then, it is critical to model all the defects accurately for their lithographic impact. Finally, an accurate lithography-based set of reticle defect disposition criteria can be developed for the manufacturing process flow. The focus of this study is on contact or hole patterns since the issues regarding capture of defects on such patterns are typically more complex than the ones on line and space patterns. The intent is to assess and devise defect disposition criteria for contact hole layers utilizing KLA-Tencor's 5X6 DUV inspection system with both standard die-to-die and Litho2 algorithms and the Automated Mask Defect Disposition (AMDD) system. AMDD lithographic printability results will be compared to AIMS results and printed results on wafer.
Beam-splitter and cell-window errors in fluorescence spectrometry.

Fluorescence excitation spectra should be corrected for distortions caused by spectral variations in the transmittance/reflectance ratio of the beam splitter and by variations in the transmittance of cell windows. The polarization of the excitation beam may cause a large uncertainty in the beam-splitter correction, but this source of error can be eliminated by using angles of incidence of 15°, or less, at the beam splitter. The small distortions due to the transmittances of the sample-cell and quantum-counter entrance windows can be made to cancel one another it the angle of incidence at the quantum counter is also 15° or smaller.
Binding domains for blockers and substrates on the cloned human dopamine transporter studied by protection against N-Ethylmaleimide-induced reduction of 2β-carbomethoxy-3β-(4-fluorophenyl)[3H]tropane ([3H]WIN 35,428) binding

Binding sites for 2β-carbomethoxy-3β-(4-fluorophenyl)[3H]tropane ([3H]WIN 35,428) on the human dopamine transporter expressed in C6 glioma cells were alkylated with N-ethylmaleimide (NEM), and the protective potency of the blockers cocaine, N[1-(2-benzo[b]thiophenyl)cyclohexyl]piperidine (BTCP), and benztropine, and of the substrates dopamine, d-amphetamine, and norepinephrine was measured. In general, the protective potency was lower (at least 4–5 times) than the potency in inhibiting [3H]WIN 35,428 binding with the compounds present under the same experimental conditions used for the NEM alkylation. However, the disparity was substantially greater for all substrates tested (23- to 44-fold) than for the blockers (4- to 11-fold), especially cocaine (5-fold) and BTCP (4-fold). Benztropine took an intermediate place (11-fold) between cocaine (5-fold) and BTCP (4-fold), on the one hand, and dopamine (23-fold), on the other hand. [3H]WIN 35,428 binding was best described by a one-site model under the present conditions. The results are discussed in terms of models involving blocker-induced conformational changes and overlapping nonidentical binding domains for blockers and substrates.
Band-Pass Low-Pass Transformation in Variable Networks

An extension of the band-pass low-pass transformation to linear varying-parameter systems is developed. It is shown that this transformation in conjunction with the use of frequency analysis techniques can be applied with advantage to the analysis of a superregenerator operating in the linear mode.
Statistical analysis of quiet stance sway in 2-D.

Subjects exposed to a rotating environment that perturbs their postural sway show adaptive changes in their voluntary spatially directed postural motion to restore accurate movement paths but do not exhibit any obvious learning during passive stance. We have found, however, that a variable known to characterize the degree of stochasticity in quiet stance can also reveal subtle learning phenomena in passive stance. We extended Chow and Collins (Phys Rev E 52(1):909–912, 1995) one-dimensional pinned-polymer model (PPM) to two dimensions (2-D) and then evaluated the model’s ability to make analytical predictions for 2-D quiet stance. To test the model, we tracked center of mass and centers of foot pressures, and compared and contrasted stance sway for the anterior–posterior versus medio-lateral directions before, during, and after exposure to rotation at 10 rpm. Sway of the body during rotation generated Coriolis forces that acted perpendicular to the direction of sway. We found significant adaptive changes for three characteristic features of the mean square displacement (MSD) function: the exponent of the power law defined at short time scales, the proportionality constant of the power law, and the saturation plateau value defined at longer time scales. The exponent of the power law of MSD at a short time scale lies within the bounds predicted by the 2-D PPM. The change in MSD during exposure to rotation also had a power-law exponent in the range predicted by the theoretical model. We discuss the Coriolis force paradigm for studying postural and movement control and the applicability of the PPM model in 2-D for studying postural adaptation.
Malonyl-CoA decarboxylase from the uropygial gland of waterfowl: Purification, properties, immunological comparison, and role in regulating the synthesis of multimethyl-branched fatty acids☆

Abstract Analysis of the acyl portion of the wax from the uropygial gland of muscovy duck, wood duck, (Cairininae subfamily) and Canadian goose (Anserinae) by combined gas-liquid chromatography and mass spectrometry showed that 2,4,6-trimethyloctanoic acid and 2,4,6-trimethylnonanoic acid were the major (~100%) components. Similar analyses of the wax from the glands of mallard and Peking duck (Anatinae) showed that 2- and 4-mono-methylhexanoic acids predominated (>75%) with no multimethyl-branched acids. The uropygial glands of the former group contained 20 to 100 times as much malonyl-CoA decarboxylase activity as those of the latter group. These results strongly support the hypothesis that this decarboxylase, by causing specific decarboxylation of malonyl-CoA, makes available only methylmalonyl-CoA for fatty acid synthesis, and thus causes the production of multimethyl-branched acids. Malonyl-CoA decarboxylase was purified to apparent homogeniety in 30% yield from the uropygial glands of muscovy and wood ducks. Properties of the enzyme from the ducks, such as S20.w (7.8 S), molecular weight (190,000) subunit composition (4 × 47,000), amino acid composition, strict substrate specificity, pH optimum (~9.0), Km (~33 μ m ), V (~80 μmol/min/mg), and inhibition by SH-directed reagents were similar to those observed with the decarboxylase from the domestic goose. Antiserum prepared against the goose enzyme cross-reacted with and inhibited the decarboxylase from the four genera of ducks and Canadian goose. Ouchterlony double-diffusion analyses showed fusion of precipitant lines with the enzyme from muscovy, wood duck, and Canadian goose, whereas spurs were observed with the enzymes from mallard and Peking ducks. Immunoelectrophoresis showed that the decarboxylases from muscovy and wood ducks were similar and that they were different from the enzyme from the domestic goose. It appears that during evolution, the subfamilies (Anserinae and Cairininae) which synthesize multimethyl-branched acids acquired the ability to produce a high level of malonyl-CoA decarboxylase, an enzyme which is also present in low levels in other organisms.
Particle fouling in submerged microfiltration membranes: effects of hollow-fiber length and aeration rate

The effects of fiber length and aeration rate on permeate flux decline in tests of a single, submerged, hollow-fiber microfiltration at constant pressure are presented. Without aeration, the initial permeate flux was greater for shorter fiber length (0.3 vs. 0.7 vs. 1 m) at a relatively low feed concentration of bentonite particles (0.1 g/L). However, the same pseudo-steady state in permeate flux was eventually reached for all three fiber lengths as fouling progressed. The fouling rate was greatly reduced by aeration rate for all three fiber lengths. However, the effect was larger as fiber length became shorter. Aeration was not effective for removal of the fouling layer formed near the fiber outlet where the local flux is expected to be highest for the longest fiber length. In the absence of aeration, permeate flux decline was over-predicted slightly in a hollow fiber model by using the specific cake resistance from a small-scale, flat-sheet microfiltration test. The explanation may involve the effect of the axial gradient of pressure drop on local cake resistance for compressible cakes. Aeration changed the structure of the fouling layer such that specific cake resistance was lower than obtained from the flat-sheet test wherein the aeration is not simulated.
Temperature inversion and freeze protection by wind machine

Abstract Two years of observation in a cherry orchard at The Dalles, Oregon show that temperature inversions occur nightly except under such conditions as rain. Inversions between 4 and 60 ft. varied from 1° to 9° in the spring of 1970. It is shown statistically that an inversion of at least 5° can be anticipated each night with 99% confidence. A tower mounted wind machine with two fans was used in this orchard. Each fan produced 1,310 lb. of thrust and the machine rotated on its base each nine minutes. There is likelihood that the temperature was influenced over an area of 23 acres. The temperature of 7.5 acres of orchard was kept in the fruit safety zone and an area with a radius of 260 ft. was kept at 30° F or higher on all “cold” nights.
Chemical modification of the crayfish neuromuscular junction.

Abstract 1. 1. The effect of specific reagents on neuromuscular transmission in the crayfish claw abductor muscle and its excitatory and its excitatory nerve is reported. 2. 2. Twenty m M I -ethyl-3(3- dimethylaminopropyl) carbodiimide (EDC) causes a decrease in quantal content of the excitatory nerve. 3. 3. Crayfish excitatory junctional potential heights and muscle membrane resistance are unaffected by p H 4.8 up to 30 minutes. 4. 4. EDC had no effect on membrane resistance or quantal size. 5. 5. There is no evidence for a disulphide bond at or near the glutamate receptor. 6. 6. Acid and alkaline phosphatase had no effect on neuromuscular transmission. 7. 7. The effects of various other chemicals are reported.
Macrovolt T-Wave Alternans and Polymorphic Ventricular Tachycardia

A previously healthy 18-year-old woman presented to her local hospital with 3 days of heart failure symptoms. An echocardiogram showed severe left ventricular dilation and global hypokinesis with an ejection fraction of 17%. Her history and clinical evaluation were consistent with an acute virus-induced cardiomyopathy. She had not taken any medications before her presentation, and her initial ECG was normal. On hospital …
Electroviscous flow and electrophoretic motion during erythrocyte entry in a glass capillary in the presence of applied electric potential gradients.

One means of measuring an effect of erythrocyte deformability on red cell flow is to determine how long it takes erythrocytes to enter or flow through an aperture whose diameter is smaller than 8 μm. It is convenient to impose an electric potential difference across the aperture so that the passage of an erythrocyte can be monitored by electronic means. We report here that such electric potential gradients may have a large influence on red cell entry times, primarily through the mechanism of erythrocyte electrophoretic mobility.
Modal analysis of the steady state response of a driven periodic linear system

Abstract A modal analysis method is developed that predicts the steady state response of discrete linear systems that are governed by systems of ordinary differential equations with periodic coefficients. The systems are excited both parametrically by periodic coefficients and directly by inhomogeneous forcing terms that have the same period. In the method, the solution for the steady state vibration is expressed as a linear combination of the Floquet eigenvectors, which are orthogonal with respect to solutions of the associated adjoint problem. The approach is applicable either when the Floquet eigensolutions have been obtained numerically through the transition matrix, or when they are found analytically through perturbation methods. For this reason, implementation of the present modal analysis solution can be computationally efficient, even if the dimension of the system is large. The approach is demonstrated by an application to Mathieu’s equation.
Formaldehyde Vapor Exposures in Anatomy Laboratories

This study examined formaldehyde vapor exposures that occurred in the gross anatomy laboratories of a major medical school during a 12-week study period. Formaldehyde samples were collected using personal sampling pumps to draw air through midget impingers containing a 0.1% solution of sodium bisulfite dissolved in deionized water as the absorbing medium. Breathing zone and ambient air samples were collected and analyzed from 8 laboratories on a rotating basis. Analysis was via the chromotropic acid method recommended by the National Institute for Occupational Safety and Health. It was found that 44% of all breathing zone samples were greater than the 1.0 ppm ceiling value for occupational exposure recently recommended by the American Conference of Governmental Industrial Hygienists. Only 11% of ambient air samples were in excess of 1.0 ppm.
Ichnofossils and rhizoliths of the nearshore fluvial Jebel Qatrani Formation (Oligocene), Fayum Province, Egypt

Abstract The ichnofossils and rhizoliths of the Oligocene Jebel Qatrani Formation of Egypt are among the best preserved, most diverse in form, and most abundant of such structures yet recognized in fluvial rocks. Twenty-one forms are described. The ichnofauna contains traces (domichnia, fodinichnia, cubichnia) of probable annelid, insect, crustacean, and vertebrate origin. These include the first described fossil nest structures and gallery systems of subterranean termites (Isoptera), the first examples of Ophiomorpha from wholly fluvial rocks, and the first fossil vertebrate burrows from the African Tertiary. Rhizoliths associated with the ichnofauna and those occurring elsewhere document a variety of small, wetland plants, coastal mangroves, and much larger trees. The environment suggested by these traces is consistent with the coastal, tropical to subtropical, monsoonal rain forest, with adjacent more open areas, that is indicated by independent evidence of sedimentology, paleontology, and paleopedology.
Cholangiocytes express the aquaporin CHIP and transport water via a channel-mediated mechanism

Abstract Cholangiocytes line the intrahepatic bile ducts and regulate salt and water secretion during bile formation, but the mechanism(s) regulating ductal water movement remains obscure. A water-selective channel, the aquaporin CHIP, was recently described in several epithelia, so we tested the hypothesis that osmotic water movement by cholangiocytes is mediated by CHIP. Isolated rodent cholangiocytes showed a rapid increase in volume in the presence of hypotonic extracellular buffers; the ratio of osmotic to diffusional permeability coefficients was > 10. The osmotically induced increase in cholangiocyte volume was inversely proportional to buffer osmolality, independent of temperature, and reversibly blocked by HgCl2. Also, the luminal area of isolated, enclosed bile duct units increased after exposure to hypotonic buffer and was reversibly inhibited by HgCl2. RNase protection assays, anti-CHIP immunoblots, and immunocytochemistry confirmed that CHIP transcript and protein were present in isolated cholangiocytes but not in hepatocytes. These results demonstrate that (i) isolated cholangiocytes and intact, polarized bile duct units manifest rapid, mercury-sensitive increases in cell size and luminal area, respectively, in response to osmotic gradients and (ii) isolated cholangiocytes express aquaporin CHIP at both the mRNA and the protein level. The data implicate aquaporin water channels in the transcellular movement of water across cholangiocytes lining intrahepatic bile ducts and provide a plausible molecular explanation for ductal water secretion.
Tomasch effect as a probe of the dispersion relation of electrons in ''gapless'' superconductors

The recent theory of McMillan and Anderson is used to discuss the effect of nonmagnetic impurities and depairing mechanisms on the period and damping of the Tomasch oscillations. These oscillations in the density of states seem to provide a unique way of directly measuring the dispersion relation of electronic excitations in superconductors [$\ensuremath{\omega}$ versus $\mathrm{Re}{({\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{\ensuremath{\omega}}}^{2}\ensuremath{-}{\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{\ensuremath{\Delta}}}^{2})}^{\frac{1}{2}}\ensuremath{\propto}$ pseudomomentum ${k}^{*}$, where $\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{\ensuremath{\omega}}$ and $\ensuremath{\Delta}$ are the usual renormalized diagonal and off-diagonal self-energies]. We shall discuss the theoretical dispersion curves for films with a small concentration of magnetic impurities and for dirty films ($l\ensuremath{\ll}{\ensuremath{\xi}}_{0}$) in the presence of a parallel magnetic field. The two situations lead to quite different dispersion curves at small values of ${k}^{*}$, for the same value of the depairing parameter. Using the Tomasch effect to plot out the dispersion curves becomes more difficult as $\ensuremath{\omega}$ decreases, since the damping of the oscillations [$\ensuremath{\propto}\mathrm{Im}{({\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{\ensuremath{\omega}}}^{2}\ensuremath{-}{\stackrel{\ifmmode \tilde{}\else \~{}\fi{}}{\ensuremath{\Delta}}}^{2})}^{\frac{1}{2}}$] increases.
An amino acid transport system in Streptococcus faecium.

Abstract Streptococcus faecium possesses an amino acid transport system which acts on glycine and l -alanine. It also probably functions with l -serine, and to a lesser extent with threonine, l -valine, and l -cysteine. d -Amino acids, peptides, esters, and amides are not competitors for glycine uptake. The system is temperature dependent but shows little glucose requirement and is not inhibited strongly by various metabolic inhibitors. Using uptake at 1 min. incubation as a measure of the initial rate, the system can be shown to obey Michaelis-Menten kinetics. Glycine and l -alanine show identical K m values, and as competitive inhibitors of each other show the same K I values. The uptake process is an exchange reaction, and the entry and exit reactions are probably coupled. Cells can synthesize alanine and retain it within their free amino acid pool. Alanine in the pool apparently exchanges with external glycine, serine, or threonine needed for growth. In this way the organism is able to obtain from its environment amino acids it requires in exchange for one it can make. Inhibitory inter actions of these amino acids may also involve reaction with the transport system.
Nanomechanics of Thin Films

Recognition of the importance of the mechanical properties of thin deposited films has received increasing attention over the past decade. The film or near surface region must be treated as a material to understand its particular mechanical properties in terms of the unique microstructure present. A vapor condensed film often has an extremely small grain size and gives brittle behavior. It is not uncommon to form an impurity stabilized amorphous film during growth. In this paper emphasis is placed on concepts and recent instrumentation for measurements of the stress during film deposition. This growth stress and its distribution results from the microstructure plus the mechanical constraints of the underlying material, and may be modified by the processing. Both elastic and plastic components are present and local deformation maps allow a reasonable level of modelling. Lacking in this approach are experimental material parameters for the film, near surface, or interfacial material. New data for the tensile properties of cast polystyrene and SiO films is presented.
Acousto-optic processor for carrier frequency and envelope modulation analysis

An acousto-optic processor capable of analyzing signals consisting of a high frequency carrier modulated by an envelope signal is described. Space-integrating spectral analysis is used to channelize signals by carrier frequency. Time-integrating spectral analysis is used to characterize the envelope signal that modulates each carrier frequency. The output is a two- dimensional display with carrier frequency along one axis and envelope frequency along the orthogonal axis. Several advantages of the processor are explained and proof-of-concept experimental results are presented. One possible application of the processor is to the automatic separation and determination of the carrier frequencies and pulse repetition frequencies of multiple received radar signals.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Repeated cocaine exposure increases fast-spiking interneuron excitability in the rat medial prefrontal cortex

The medial prefrontal cortex plays a key role in cocaine addiction. However, how chronic cocaine exposure affects cortical networks remains unclear. Most studies have focused on layer 5 pyramidal neurons (the circuit output), while the response of local GABAergic interneurons to cocaine remains poorly understood. Here, we recorded from fast-spiking interneurons (FS-IN) after repeated cocaine exposure and found altered membrane excitability. After cocaine withdrawal, FS-IN showed an increase in the number of spikes evoked by positive current injection, increased input resistance, and decreased hyperpolarization-activated current. We also observed a reduction in miniature excitatory postsynaptic currents, whereas miniature inhibitory postsynaptic current activity was unaffected. We show that, in animals with cocaine history, dopamine receptor D2 activation is less effective in increasing FS-IN intrinsic excitability. Interestingly, these alterations are only observed 1 wk or more after the last cocaine exposure. This suggests that the dampening of D2-receptor-mediated response may be a compensatory mechanism to rein down the excitability of FS-IN.
Population pharmacodynamic model for ketorolac analgesia

Objective To derive a population pharmacokinetic-pharmacodynamic model that characterizes the distribution of pain relief scores and remedication times observed in patients receiving intramuscular ketorolac for the treatment of moderate to severe postoperative pain. Background The data analysis approach deals with the complexities of analyzing analgesic trial data: (1) repeated measurements, (2) ordered categorical response variables, and (3) nonrandom censoring because the patients can take a rescue medication if their pain relief is insufficient. Methods Patients (n = 522) received a single oral or intramuscular administration of placebo or a single intramuscular dose of 10, 30, 60, or 90 mg ketorolac for postoperative pain relief. Pain relief was measured periodically with use of a five-category ordinal scale up to 6 hours after dosing. In this period, 288 patients received additional medication because of insufficient pain relief. Pharmacokinetic data was available for 85 subjects. Models were fitted to the data with the NONMEM program. Results The pharmacokinetic data was best described by a two-compartment model with first-order absorption. Pain relief was found to be a function of drug concentration (Emax model), time (waxing and waning of placebo effect), and an individual random effect. The drug concentration at half-maximal effect (EC50) and the first-order rate constant (keo) half-life for pain relief were 0.37 mg/L and 24 minutes. The probability of remedication was found to be a function of the observed level of pain relief and was found to increase with time. Monte Carlo simulations showed that adequate pain relief was achieved in 50% of the patients at 41, 27, 23, and 21 minutes after 10, 30, 60, or 90 mg of intramuscular ketorolac. Adequate pain relief was maintained up to 6 hours in 50%, 70%, 78%, and 81% of patients after these four doses. Only 25% of the patients achieved adequate pain relief with placebo. Conclusions A population pharmacokinetic-pharmacodynamic model for the analgesic efficacy of intramuscular ketorolac was derived. The simulated relationship between dose, time, and percentage of patients with adequate pain relief suggested that 30 mg intramuscular ketorolac was the optimal initial dose for postoperative pain relief. Clinical Pharmacology & Therapeutics (1996) 60, 619–635; doi:
Some rectangular designs constructed by the method of differences

Abstract Some new series of rectangular designs are constructed by the method of differences.
Relation between the anion exchange protein in kidney medullary collecting duct cells and red cell band 3.

A membrane protein that is immunochemically similar to the red cell anion exchange protein, band 3, has been identified on the basolateral face of the outer medullary collecting duct (MCD) cells in rabbit kidney. In freshly prepared separated rabbit MCD cells, M.L. Zeidel, P. Silva and J.L. Seifter (J. Clin. Invest.77:1682–1688, 1986) found that Cl−/HCO 3 - exchange was inhibited by the stilbene anion exchange inhibitor, DIDS (4,4′-diisothiocyano-2,2′-disulfonic stilbene), with aK1 similar to that for the red cell. We have measured the binding affinities of a fluorescent stilbene inhibitor, DBDS (4,4′-dibenzamido-2,2′-disulfonic stilbene), to MCD cells in 28.5 mM citrate and have characterized both a high-affinity site (K 1 s =93±24 mM) and a lower affinity site (K 2 s =430±260 nM), which are closely similar to values for the red cell of 110±51 nM for the high-affinity site and 980±200 nM for the lower affinity site (A.S. Verkman, J.A. Dix & A.K. Solomon,J. Gen. Physiol.81:421–449, 1983). When Cl− replaces citrate in the buffer, the two sites collapse into a single one withK 1 s =1500±400 nM, similar to the singleK 1 s =1200±200 nM in the red cell (J.A. Dix, A.S. Verkman & A.K. Solomon,J. Membrane Biol.89:211–223, 1986). The kinetics of DBDS binding to MCD cells at 0.25 μM−1 are characterized by a fast process, τ=0.14±0.03 sec, similar to τ=0.12±0.03 sec in the red cell. These similarities show that the physical chemical characteristics of stilbene inhibitor binding to MCD cell ‘band 3’ closely resemble those for red cell band 3, which suggests that the molecular structure is highly conserved.
Evaluation of Crystallinity in Hydrated Ferric Oxides

The nature of freshly-precipitated and aged hydrated ferric oxides prepared by the addition of ferric chloride to KOH was investigated by the use of scanning and transmission electron microscopy, X-ray diffraction, i.r. absorption, and pH 3·0 ammonium oxalate extraction. The results show the fresh material to be essentially non-crystalline hydrated ferric oxide, which when aged at 60°C C and high pH rapidly crystallizes as goethite, without any indication of coexisting hematite. The various methods were evaluated as indices of crystallinity for aging materials. The acid ammonium oxalate method was shown to extract selectively only the non-crystalline portion of such mixtures. The use of X-ray diffraction analysis for estimating aging stage requires elimination of the preferred orientation of the goethite crystals. While both the oxalate and X-ray methods can detect as little as 2 per cent crystallinity, the oxalate method is probably superior for quantitative determinations as it depends directly on an inherent difference in the solubility of the crystalline and non-crystalline materials, rather than on a technique dependent intensity measurement. The use of the intensity of the O-H bending vibrations of the infrared absorption spectra can also potentially detect as little as 2 per cent crystallinity, but the procedure is probably less useful for quantitative determinations than the oxalate or X-ray methods because of the problem of evaluating the area under the peaks.
Wound Healing Finally Enters the Age of Molecular Diagnostic Medicine.

Background: Many wounds are difficult to heal because of the large, complex community of microbes present within the wound. The Problem: Classical laboratory culture methods do not provide an accurate picture of the microbial interactions or representation of microorganisms within a wound. There is an inherent bias in diagnosis based upon classical culture stemming from the ability of certain organisms to thrive in culture while others are underrepresented or fail to be identified in culture altogether. Chronic wounds also contain polymicrobial infections existing as a cooperative community that is resistant to antibiotic therapy. Basic/Clinical Science Advances: New methods in molecular diagnostic medicine allow the identification of nearly all organisms present in a wound irrespective of the ability of these organisms to be grown in culture. Advances in DNA analyses allow absolute identification of microorganisms from very small clinical specimens. These new methods also provide a quantitative represent...
Redbanded Stink Bug (Hemiptera: Pentatomidae) Infestation and Occurrence of Delayed Maturity in Soybean

Studies done in Brazilian soybean, Glycine max (L.) Merril, in the 1970s suggested the redbanded stink bug, Piezodorus guildinii (Westwood), is principally responsible for delayed maturity in this crop. This stink bug species has recently emerged as a serious pest of soybean in the southern United States, where little is known about its association with the occurrence of delayed maturity disorder. Also, the mechanism behind stink bug-induced soybean delayed maturity remains unknown. It is believed that stink bug feeding during pod development stages results in reduced pod-seed load, causing alteration of source-sink ratio and eventually delayed maturity. To determine the P. guildinii threshold triggering delayed maturity in soybean, experiments were conducted with varying levels of P. guildinii infestation (0, 2, 4, and 8 adults per 0.3 m) during the R4 to R5 soybean growth stages. In addition, to determine if soybean delayed maturity is exclusively because of reduced pod load, experiments with different levels of mechanical pod removal (0, 25, 50, and 75%) were conducted on field-grown soybeans. P. guildinii densities up to 4 adults per 0.3 m did not trigger occurrence of delayed maturity. However, a density of 8 adults per 0.3 m produced a significant increase in the number of green leaves retained on plants at maturity (i.e., delayed maturity). There was no effect of mechanical pod removal on green leaf retention. The lack of a significant positive correlation between mechanical pod removal and green leaf retention indicates the involvement of mechanism(s) other than reduced pod load in the occurrence of soybean delayed maturity.