cssi/SciSciGPT-SciSciNet huggingface dataset:
Resonant electron capture by some amino acids esters

Resonant electron capture by Gly, Ala and Phe esters have shown that the most efficient negative ion (NI) fragmentations are associated with the C-termini. A new mechanism for the negative ion-forming processes at energies lower than those associated with the pi*(OO) shape resonance involves coupling between dipole-bound and valence negative ion states of the same symmetry for amino acid conformers with high permanent dipoles. The interaction avoids crossing of the NI states and instead leads to formation of two adiabatic potential energy surfaces. Underivatized amino acids most effectively fragment from the bottom adiabatic surface via generation of [M-H](-) carboxylate anions by hydrogen-atom tunneling through the barrier; fragmentation of the their esters with formation of analogues [M-X](-) NIs occurs through the upper adiabatic state without penetration of the barrier in which the energy of the valence sigma*OX resonance exceeds the bond dissociation energy of the neutral molecule. Low and high temperature resonant electron capture experiments point to the importance of conformational preferences of the amino acids for optimum dissociation of the parent NIs in the gas phase.
Emission tomography from compressed data

In emission tomographic modalities such as SPECT or PET, various regions of the detector space yield different amounts of information about the emission source. A framework for exploring the tradeoffs between binning the detector space is developed to reduce memory storage and the associated loss in performance for image reconstruction tasks and detection tasks. We use high rate vector quantization theory to establish just how much relevant information can be preserved after compression of the emission measurement data. We illustrate our results for one dimensional deconvolution and two dimensional lesion detection in PET.
Enzymatic synthesis of mannosyl-1-phosphoryl-decaprenol by a cell-free system of Mycobacterium tuberculosis.

Abstract A particulate cell-free enzyme system of the H37Ra strain of Mycobacterium tuberculosis catalyzes the incorporation of mannose from GDP-d-mannose into several lipids. The major product of this reaction (representing about 60% of the total mannolipids formed) is an alkali-stable, acid-labile mannolipid. This new lipid was isolated in a high state of purity from a preparative scale synthesis experiment with uniformly labeled GDP-d-mannose-14C as the substrate, mycobacterial crude phospholipid as the acceptor, and the particulate transmannosylase enzyme system from M. tuberculosis. The product was characterized and is 14C-mannosyl-1-phosphoryl-decaprenol.
Hardness of submodular cost allocation : lattice matching and a simplex coloring conjecture

We consider the Minimum Submodular Cost Allocation (MSCA) problem. In this problem, we are given k submodular cost functions f_1, ... , f_k: 2^V -> R_+ and the goal is to partition V into k sets A_1, ..., A_k so as to minimize the total cost sum_{i = 1}^k f_i(A_i). We show that MSCA is inapproximable within any multiplicative factor even in very restricted settings; prior to our work, only Set Cover hardness was known. In light of this negative result, we turn our attention to special cases of the problem. We consider the setting in which each function f_i satisfies f_i = g_i + h, where each g_i is monotone submodular and h is (possibly non-monotone) submodular. We give an O(k log |V|) approximation for this problem. We provide some evidence that a factor of k may be necessary, even in the special case of HyperLabel. In particular, we formulate a simplex-coloring conjecture that implies a Unique-Games-hardness of (k - 1 - epsilon) for k-uniform HyperLabel and label set [k]. We provide a proof of the simplex-coloring conjecture for k=3.
Neural network controller for turning operation of a metal cutting process

In this paper, the design and implementation of an effective neural network(NN) for process identification as well as a neural network controller to track a desired cutting force under payload variations are presented. The proposed learning algorithm for the NN is backpropagation. In addition, an online controller algorithm is developed for the turning operation to track the desired force trajectory as closely as possible in spite of wide ranges of disturbances and payload variations for each metal cutting task. The simulation experiments demonstrate the effectiveness of the proposed method.
A Theoretical Examination of Waterpipe Smoking in College Students

The purpose of this study was to identify variables associated with waterpipe smoking in college students using the Theory of Reasoned Action (TRA). Of the sample (N = 104), 50% had ever smoked a waterpipe, while 43% reported ever smoking a cigarette. Examined individually, intention, attitudes, and subjective norms were each significantly associated with waterpipe smoking controlling for demographics and tobacco use. When the variables were entered into the model simultaneously, the overall model was significant, with an area under the receiver operating characteristic curve (AUC) of 0.869, indicating the model has good to excellent discrimination between smokers and nonsmokers. Attitude remained significantly associated with future waterpipe smoking.
Power-law flow statistics in anisometric (wedge) hoppers.

We find the probability for $N$ particles to exit an anisometric (having unequal dimensions) hopper before jamming to have a broad power-law decay with exponent $\ensuremath{\alpha}=\ensuremath{-}2$, in marked contrast to the exponential decay seen in hoppers with symmetric apertures. The transition from exponential to power law is explained by amodel that assumes particle motion is correlated over a distinct length scale. Hoppers with lengths larger than this length are modeled as a series of adjacent, statistically independent ``cells.'' Experiments with apertures 27--37 particle diameters $D$ long are well fit by a three-cell model, implying that the correlation length is $\ensuremath{\approx}9$--$12D$.
Effects of counterion identity on a micellar liquid crystal

Abstract Magnetic birefringence measurements are reported for mixtures of cesium- and rubidium-perfluorooctanoate in water above the nematic-isotropic phase transition temperature. Despite significant differences in the phase diagrams between the two materials, it was found that both the supercooling temperature T∗ of the isotropic phase, as well as the micelle aggregation number, are quite insensitive to relative surfactant concentration.
Activation of cyclic nucleotide phosphodiesterases in FRTL-5 thyroid cells expressing a constitutively active Gs alpha.

The expression of a constitutively activated Gs alpha protein in the rat thyroid cell line FRTL-5 causes an increase in the hormone-independent adenylyl cyclase activity and promotes TSH-independent growth of the cells. In spite of the constitutive activation of the adenylyl cyclase, the basal cAMP levels in these cells are only marginally increased. To define the role of phosphodiesterases (PDEs) in the genesis of this phenotype, cyclic nucleotide hydrolysis was determined in two cell lines expressing a mutated Gs alpha (Q227L). In these cells, the hydrolysis of both cAMP and cGMP was markedly increased in comparison with normal cells. This increase is the result of the activation of different forms of PDEs. Analysis of the cGMP hydrolysis and Ca++/calmodulin stimulation of the PDE activity indicated that the activity of a Ca++/calmodulin-stimulated PDE is increased in both cell lines. In addition, an increase in high-affinity, rolipram-sensitive cAMP-PDE activity was associated in both cell lines with t...
A method for the microinjection and culture of protoplasts at very low densities

A method has been developed which allows the recovery of calli from a high proportion of individual, injected, mesophyll protoplasts of Nicotiana tabacum c.v. Xanthi. A small drop of low melting point agarose is used both to hold protoplasts during microinjection and for their subsequent culture in feeder dishes. The feeder dishes consist of "beads" of protoplasts at a high density set in agarose to "feed" the infected protoplasts across a liquid medium. The method has been used successfully both with normal protoplasts and protoplasts from which the vacuole has been removed.
A comparison of portfolio theory and weighted utility models of risky decision making

Abstract Weighted utility models attempt to account for risk preferences in terms of an expectation-like equation applied to the subjective evaluation of probabilities and outcomes, while Portfolio theory assumes that risk preference is a function of expected value and perceived risk. A pair of empirical predictions which contrasts Portfolio theory with all weighted utility models is derived and tested. Results indicate that both theories are in error. In the case of Portfolio theory, it is clearly the axiom of single-peakedness over risk that is violated.
Value-based management consulting in a third world country located within the United States

The Navajo Nation (the Navajo Reservation in the western United States) appears to be a third world country within the boundaries of one of the most prosperous and technically advanced countries in the world. This paper discusses the cultural and economic factors that have been ignored by business consultants to the Native Americans, especially the Navajo. The economic plight of the Navajo can be partially blamed on the application of generic management techniques for the past 40 years by consultants treating the Navajo as members of their own dominate culture. This paper also discusses the ethical implications of ignoring cultural differences under the guise of supplying professional services to minority cultures.
Control of Multiple Robotic Sentry Vehicles

As part of a project for the Defense Advanced Research Projects Agency, Sandia National Laboratories is developing and testing the feasibility of using of a cooperative team of robotic sentry vehicles to guard a perimeter and to perform surround and diversion tasks. This paper describes on-going activities in the development of these robotic sentry vehicles. To date, we have developed a robotic perimeter detection system which consists of eight ''Roving All Terrain Lunar Explorer Rover'' (RATLER{trademark}) vehicles, a laptop-based base-station, and several Miniature Intrusion Detection Sensors (MIDS). A radio frequency receiver on each of the RATLER vehicles alerts the sentry vehicles of alarms from the hidden MIDS. When an alarm is received, each vehicle decides whether it should investigate the alarm based on the proximity of itself and the other vehicles to the alarm. As one vehicle attends an alarm, the other vehicles adjust their position around the perimeter to better prepare for another alarm. We have also demonstrated the ability to drive multiple vehicles in formation via tele-operation or by waypoint GPS navigation. This is currently being extended to include mission planning capabilities. At the base-station, the operator can draw on an aerial map the goal regions to bemore » surrounded and the repulsive regions to be avoided. A potential field path planner automatically generates a path from the vehicles' current position to the goal regions while avoiding the repulsive regions and the other vehicles. This path is previewed to the operator before the regions are downloaded to the vehicles. The same potential field path planner resides on the vehicle, except additional repulsive forces from on-board proximity sensors guide the vehicle away from unplanned obstacles.« less
Predicting poor outcomes for back pain seen in primary care using patients' own criteria

Study design A prospective cohort study of patients seen in primary care for low back pain. Objectives A new measure of back pain outcomes is used to describe the status of back problems at various intervals after visits to primary care physicians and to identify subsets of patients with worse prognoses. Summary of background data Most previous studies of the prognosis of back pain in primary care have failed to provide clinically useful information. Methods Baseline data were collected from 219 patients making an initial visit for an episode of low back pain to a primary care clinic. A measure of how patients reported they would feel if they had their current back symptoms for the rest of their lives ("Symptom Satisfaction") was used to distinguish good from poor outcomes. Patient outcomes were assessed 1, 3, 7, and 52 weeks after the index visit. Results Only 67% of patients reported good outcomes after 7 weeks, and only 71% were satisfied with their condition 1 year later. After controlling for the effects of other variables measured during the initial physician visit, only younger age, depression, and pain below the knee were significant predictors of poor outcome at 7 weeks, and only pain below the knee and depression were significant predictors at 1 year. Conclusions The proportion of primary care patients with back pain who have poor outcomes appears to be higher than generally recognized. Ways of improving how primary care responds to patients with persisting pain should be investigated.
Distinct Roles for Key Karyogamy Proteins during Yeast Nuclear Fusion

During yeast mating, cell fusion is followed by the congression and fusion of the two nuclei. Proteins required for nuclear fusion are found at the surface (Prm3p) and within the lumen (Kar2p, Kar5p, and Kar8p) of the nuclear envelope (NE). Electron tomography (ET) of zygotes revealed that mutations in these proteins block nuclear fusion with different morphologies, suggesting that they act in different steps of fusion. Specifically, prm3 zygotes were blocked before formation of membrane bridges, whereas kar2, kar5, and kar8 zygotes frequently contained them. Membrane bridges were significantly larger and occurred more frequently in kar2 and kar8, than in kar5 mutant zygotes. The kinetics of NE fusion in prm3, kar5, and kar8 mutants, measured by live-cell fluorescence microscopy, were well correlated with the size and frequency of bridges observed by ET. However the kar2 mutant was defective for transfer of NE lumenal GFP, but not diffusion within the lumen, suggesting that transfer was blocked at the NE fusion junction. These observations suggest that Prm3p acts before initiation of outer NE fusion, Kar5p may help dilation of the initial fusion pore, and Kar2p and Kar8p act after outer NE fusion, during inner NE fusion.
Decreased premature ventricular contractions through use of the relaxation response in patients with stable ischaemic heart-disease.

To determine whether decreased sympathetic-nervous-system activity achieved by the relaxation response could decrease premature ventricular contractions (P.V.C.s), eleven ambulatory patients with proven, stable ischaemic heart-disease and P.V.C.s were investigated. The patients, who were taking no medication for the P.V.C.s, were trained to elicit regularly the relaxation response through a non-cultic psychological technique. The frequency of the P.V.C.s was measured by computer analysis of Holter monitor tapes for 2 complete days before learning the technique, which was learned in approximately 5 minutes after the second day. Patients were instructed to evoke the response for 20 minutes twice daily thereafter. After 4 weeks, a reduced frequency of P.V.C.s was documented in eight of the eleven patients. This effect was especially striking during the sleeping hours and less so during the entire monitoring session. The relaxation response is a simple, no cost, non-pharmacological mechanism without side-effects which seemed to decrease the frequency of P.C.V.s in most patients with ischaemic heart-disease.
The effect of condensed distillers solubles on the physical and chemical properties of maize distillers dried grains with solubles (DDGS) using bench scale experiments

This study was undertaken to understand the effect of variable quantities of condensed distillers solubles (CDS) mixed with wet distillers grains (WDG) from maize on the physical and chemical characteristics of distillers dried grains with solubles (DDGS) using a bench-scale experiment. DDGS produced with 0, 10 and 20% CDS by percentage mass showed that particle size, particle size distribution, and particle density increased with CDS levels from 0 to 20%. DDGS with varying CDS levels had significantly different amounts of crude protein, crude fat, ash, total reducing sugars and amino acids. The chemical composition of DDGS in this study and a plant-scale study by Kingsly et al. (2010) were comparable, but not their physical characteristics. Therefore, caution should be taken when preparing DDGS samples for use in studying granular properties using bench-scale experiments which have been used by others in previous studies. An empirical model was developed to predict the chemical composition of DDGS based on the chemical composition of its two wet streams.
Synthesis and Liquid Crystalline Properties of New Chiral Monomers and Polysiloxanes

To study the structure-property relationships of new chiral liquid crystalline materials based on menthol and explore their potential applications, a monomer 4-(4-allyloxybenzoyloxy) phenyl-4-menthyl-oxyacetyloxybiphenyl-4-carboxylate (LCM) and the corresponding homopolymer (LCP) were synthesized. The chemical structure was characterized by FT-IR and 1H NMR. The liquid crystalline properties were investigated by differential scanning calorimetry, thermogravimetric analysis, polarizing optical microscopy, and X-ray diffraction. The monomer LCM formed a cholesteric phase when a flexible linkage chain was inserted between the mesogenic core and the terminal menthyl groups by reducing the steric effect. The homopolymer LCP exhibited a batonnet texture of a smectic A phase.
The Structure of Parents' Intrafamilial Attitudes and Sentiments Measured by Objective Tests and a Vector Model

(1970). The Structure of Parents' Intrafamilial Attitudes and Sentiments Measured by Objective Tests and a Vector Model. The Journal of Social Psychology: Vol. 82, No. 2, pp. 231-252.
A computer-based technology structure for international marketing strategy development

International marketing planners and decision makers are aware of computers, computer software, the ‘information explosion’ and the ‘electronic age’, but there is little empirical evidence, other than in tactical operations, to indicate that the raw data is being converted into useful information, enhancing decision making performance, or that the trends in knowledge production and quality decisions are positive. This paper examines the state of the art, in an international context, of computer-based marketing strategy development in marketing planning at the strategic and tactical levels. It presents a structure of international marketing strategy development that provides a useful decision making perspective, and that can facilitate management problem definition and resolution. It introduces a computer-based technology structure that can assist computer-based decision making. It also links decision structure and technology structure in a parallel format, and then integrates the resulting combined struct...
Abstract 3243: Dysfunctional of TGF-β signaling via loss of β2SP activates SOX9 and C-MYC via Notch signaling in Barrett's esophageal adenocarcinoma

Background: Esophageal adenocarcinoma (EA) is often considered to arise from a clonal stem like population of cells, potentially responsible for its poor prognosis. TGF-β and Notch signaling pathways play important roles in regulating self-renewal of stem cells and gastrointestinal carcinogenesis. We have demonstrated loss of TGF-β signaling components and activation of Notch signaling in Barrett9s esophageal adenocarcinoma; however, their contributions to EA and the mechanisms of their action remain unclear. Methods: Immunoblotting and immunofluorescence were used to evaluate protein expression and localization. Notch targets Hes-1, SOX9 and C-MYC transcription were assayed using their luciferase reporters and Q-PCR. Functional studies were performed in β2SP wild type and mutant MEFs cells and in EA cell lines genetically engineered to express high or low levels of β2SP. Results: Increased levels of Notch signaling Hes1 and Jagged1 occurred in EA tissues and cell lines, compared to normal tissues. Loss of β2SP in MEFs cells increased Hes1 expression by 40 fold. In addition, SOX9, a target gene of Notch signaling and a documented stem cell marker was highly up-regulated in EA tumor cells and tissues. Expression of SOX9 was increased in the absence of β2SP in MEFs cells by 9 fold. Down-regulation of β2SP in SKTG-4, FLO-1 and BE3 EA cells by lentivirus shRNA led to increased SOX9 expression and enhanced nuclear localization of both active intracellular Notch1 domain (ICN1) and SOX9. Reintroducing β2SP into EA cells with knock down β2SP decreased SOX9 promoter activity by 10 fold. Concomitantly, an increased proportion of stem cells in β2SP knock down cells were identified using stem cell marker OCT3/4, indicating expansion of putative cancer stem cells in the absence of β2SP. Most interestingly, we observed a direct interaction between Smad3 and ICN1 via Smad3 MH1 domain by GST-pull down assays and that loss of β2SP increases the binding of Smad3 with ICN1 and induces Notch targets SOX9 and C-MYC transcription. Conclusions: Our findings suggests that loss of TGF-β signaling adaptor β2SP may switch Smad3 function from tumor suppression to tumor promotion by binding intracellular Notch1 domain (ICN1) and activating Notch signaling. Thereby, a potential therapeutic value for targeted therapy in EA is in the setting of loss of β2SP/TGF-β with active Notch signaling. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 103rd Annual Meeting of the American Association for Cancer Research; 2012 Mar 31-Apr 4; Chicago, IL. Philadelphia (PA): AACR; Cancer Res 2012;72(8 Suppl):Abstract nr 3243. doi:1538-7445.AM2012-3243
Petroleum geochemistry of the Midyan and Jaizan basins of the Red Sea, Saudi Arabia

Abstract During the 1960s, petroleum exploration activities in the offshore Red Sea areas of Saudi Arabia tested gas and condensate reservoired in the Miocene sands immediately below the Mansiyah evaporites in the offshore Midyan basin. Recent onshore exploration activity in the Red Sea has resulted in the discovery of accumulations of oil, gas and condensate in the Lower Miocene Maqna Group in the Midyan and Jaizan basins. As a result of this exploration success, an effort to understand the origin of these hydrocarbons was initiated. The two basins were assessed geochemically by addressing: (1) the potential source rocks; (2) the extent of the hydrocarbon kitchens; and (3) characterization of the hydrocarbons. The potential source rocks for the reservoired hydrocarbons are: (1) the organic-rich, oil-prone shales of the predominantly evaporitic Mansiyah Formation; (2) the variable quality shales and carbonates of the Magna Group; and (3) the moderately organic-rich shales of the Burqan and Tayran Groups. The reservoired hydrocarbons were characterized by carbon isotopes, gas chromatography-mass spectrometry and gas chromatography and compared with the potential source rocks. The results showed an acceptable match to the Maqna and Burqan organic-rich units. Detailed burial history/thermal modelling projects were undertaken to assess the hydrocarbon kitchens of both basins. Results for the Midyan basin indicated that over large areas Tayran and Burqan sediments are oil to gas mature and may be sources for the gas and/or condensate accumulations, whereas the limited area of mature Maqna sediments may be responsible for sourcing the black oil accumulations. In the Jaizan basin, the Maqna and Burqan sediments range from high oil maturity to thermally spent due to high geothermal conditions and excessive burial. The burial of the source rocks increases fairly rapidly from east to west in the Jaizan basin.
Issues and Solutions to Macroscopic Traffic Dispersion Modeling

The paper improves upon the Yu and Van Aerde calibration procedure of the TRANSYT-7F platoon dispersion model, particularly for time steps greater than 1 s in duration, and develops three generalized platoon dispersion models that explicitly account for the effect of the time step duration on traffic dispersion. The paper then validates these models utilizing two datasets: the first includes field data gathered in Montreal, while the second was generated using INTEGRATION microscopic traffic-simulation software. The results demonstrate that the predicted flow profile using the proposed platoon dispersion models provides a good fit to field-observed and simulated profiles, regardless of the modeling time step considered.
Utilizing a microcomputer-based physician incentive compensation program to increase inpatient hospital utilization and improve cost management

This paper will address the complex issues of effective cost management and declining inpatient volume. Utilizing a microcomputer-based physician incentive compensation program, it will show how a hospital developed a plan to increase inpatient hospital utilization and improve cost management. It will discuss the Internal Revenue, HCFA, and legal implications of the plan.
Snc1p v-SNARE Transport to the Prospore Membrane During Yeast Sporulation is Dependent on Endosomal Retrieval Pathways

Vesicular traffic is essential for sporulation in Saccharomyces cerevisiae. The Golgi-associated retrograde protein (GARP) tethering complex is required for retrograde traffic from both the early and late endosomes to the Golgi. Analyses of GARP complex mutants in sporulation reveal defects in meiotic progression and spore formation. In contrast, inactivation of the retromer complex, which mediates vesicle budding and cargo selection from the late endosome, or Snx4p, which is involved in retrieval of proteins from the early endosome, has little effect on sporulation. A retromer GARP double mutant is defective in the formation of the prospore membrane (PSM) that surrounds the haploid nuclei. In the retromer GARP double mutant, PSM precursor vesicles carrying the cargo, Dtr1p, are transported to the spindle pole body (SPB), where PSM formation is initiated. However, the v-SNARE Snc1p is not transported to the SPB in the double mutant, suggesting that the defect in PSM formation is because of the failure to retrieve Snc1p, and perhaps other proteins, from the endosomal pathway. Taken together, these results indicate that retrograde trafficking from the endosome is essential for sporulation by retrieving molecules important for PSM and spore wall formation.
A Numerical and Experimental Study of Compression- Loaded Composite Panels With Cutouts

Results from a numerical and experimental study on the effects of laminate orthotropy and circular cutout size on the response of compression-loaded composite curved panels are presented. Several 60-in-radius composite panels with four different laminate configurations were tested with cutout diameters that range from 10% to 60% of the panel width. Finite-element analyses were performed for each panel in order to identify the effects boundary conditions, measured initial geometric imperfections and thickness variations had on the nonlinear and buckling behavior of the panels. The compression-loaded panels considered herein exhibited two separate types of behavior depending on the laminate stacking sequence and cutout size. More specifically, some of the panels exhibited the classical snap-through type buckling response; however, some of the panels exhibited a monotonically increasing stable response and achieved compressive loads in excess of twice the predicted linear bifurcation buckling load. In general, the finite-element analyses were able to predict accurately the nonlinear response and buckling loads of the panels and the prebuckling and postbuckling out-of-plane deformations and strains.
Pharmacotherapeutic management strategies for mentally ill substance abusers

In order to determine psychiatrists' strategies for managing the pharmacotherapy and treatment of mentally ill substance abusers, the authors constructed a series of standardized clinical vignettes, each with five multiple-choice treatment interventions. The vignettes, based on clinical experience, depict difficult dilemmas involving the use of medication in the treatment of a variety of dually diagnosed patients. The authors surveyed a heterogeneous reference group of 112 psychiatrists with these vignettes. The psychometric properties of the resultant Scale for Treatment Integration of the Dually Diagnosed (STIDD) are briefly described. The ten vignettes and the treatment interventions chosen by the reference group are described in detail. The results indicate that most clinicians favor an integrated treatment approach which attempts to address both diagnoses.
The Effect of Music as a Conditioning Aid in Prepared Childbirth Education

The addition of self-selected music as a conditioning aid during prepared childbirth education and subsequent family performance in labor within a musical environment were examined. Thirty primigravida couples received the same psychoprophylactic instruction, with 15 randomly selected couples receiving the added musical conditioning aid. Medication use remained minimal, without significant difference, for couples who did and couples who did not use music. However, the value of music to both the family and the health care staff is felt to be of enough subjective significance to warrant its use as a normal component of prepared childbirth education.
Use of lipopolysaccharide (LPS) as a positive control for the evaluation of immunopotentiating drug candidates in experimental avian colibacillosis models.

The aetiologic agent of avian colibacillosis is Escherichia coli. Colibacillosis is a disease that causes mortality and production performance problems in chickens which results in economic losses for the poultry industry. It will be increasingly important for scientists to identify novel solutions that can be implemented which will provide poultry producers with a tool to manage this economically important disease. The purpose of this investigation was to determine whether lipopolysaccharide (LPS) could be used as a positive control to evaluate novel chemistries for immunopotentiator activity in battery or floor-pen avian colibacillosis models in chickens. In the battery study, subcutaneous administration of LPS to one-day-old broiler cockerels caused a significant reduction (P < 0.003) in all parameters of colibacillosis evaluated, i.e. mean air sac lesion scores, per cent air sac lesions, E. coli re-isolation and per cent mortality. However, in the floor-pen study, subcutaneous administration to one-day-old broiler chicks resulted in a numerical, but not statistically significant reduction (P < 0.1) in mortality associated with colibacillosis. These data indicate that LPS can be used as a positive control to evaluate the efficacy of immunopotentiator drug candidates in avian colibacillosis models.
Hybrid Silicon Evanescent Amplifiers

The structure and design of a hybrid silicon evanescent amplifier, incorporating III-V offset quantum wells bonded on a silicon waveguide, is proposed and discussed.
Horizon problem and the broken-symmetric theory of gravity

A way of avoiding the standard scenario (which many people find vexing on philosophical grounds) is suggested in which particles are in causal contact with only a limited number of other particles in the early universe.
Physical basis for piezoelectricity in PVDF

Abstract Consideration of the molecular and bulk structures of PVDF and related semicrystalline polymers, and the effects of processing to make transducer films, leads to a novel way of analysing the elastic and piezoelectric constant data. The results of this analysis support the conclusion that thickness changes contribute about 2/3 of the piezoelectric activity. An increase in thickness decreases the charge on the electrodes. The probable mechanism is simply the displacement of the electrodes in the fields of the constant dipole moments of the crystals. The remaining 1/3 of the activity is attributed to changes in the film's dipole moment at constant thickness. Strains in the orientation direction of the film increase the charge on the surface while strains in the plane of the film normal to the orientation direction decrease it. Eight separate possible contributions to the change in moment are discussed, and qualitative evaluations of their importance are given.
Initial stages of H2O adsorption and hydroxylation of Fe-terminated α-Fe2O3(0 0 0 1) surface

Abstract The adsorption modes of H 2 O on a Fe-terminated hematite(0 0 0 1) surface have been investigated by first principles Density Functional theory within a periodic slab model and the generalized gradient approximation. Molecular adsorption and dissociative adsorption in monolayer coverage, one H 2 O per surface Fe, were both considered. Five plausible orientations were studied to determine the most favorable adsorption position. Molecular adsorption is shown to have a small effect on the underlying surface structure, while hydroxylation has a strong effect on the surface geometry. Electronic densities of state calculations reveal details of these different interactions. The heterolytic dissociation, which produces two types of surface hydroxyls, is the preferable adsorption mode, being slightly favored energetically over the molecular adsorption. Homolytic dissociative adsorption, forming a single hydroxyl on surface Fe, is energetically unfavored, even though strong binding interaction (∼3 eV) is found between the OH radical and surface. Dissociative adsorption on an oxidized ferryl site was also studied to investigate suggested local reactivity enhancement.
Deformation behavior of a two-phase Mo–Si–B alloy

Abstract Mo–Si–B alloys are being considered as possible candidates for high-temperature applications beyond the capabilities of Ni-based superalloys. In this paper, the high-temperature (1000–1400 °C) compression response over a range of quasi-static strain rates, as well as the monotonic and cyclic crack growth behaviors (as a function of temperature from 20 °C to 1400 °C) of a two-phase Mo–Si–B alloy containing a Mo solid solution matrix (Mo(Si,B)) with ∼38 vol% of the T2 phase (Mo 5 SiB 2 ) is discussed. Analysis of the compression results confirmed that deformation in the temperature–strain-rate space evaluated is matrix-dominated, yielding an activation energy of ∼415–445 kJ/mol. Fracture toughness of the Mo–Si–B alloy varies from ∼8 MPa√m at room temperature to ∼25 MPa√m at 1400 °C, the increase in toughness with temperature being steepest between 1200 °C and 1400 °C. S–N response at room temperature is shallow whereas at 1200 °C, a definitive fatigue response is observed. Fatigue crack growth studies using R = 0.1 confirm the Paris slope for the two alloys to be high at room temperature (∼20–30) but decreases with increasing temperature to ∼3 at 1400 °C. The crack growth rate (d a /d N ) for a fixed value of Δ K in the Paris regime in the 900–1400 °C range, increases with increasing temperature.
From Macro to Micro: Methodological and Design Considerations for Biophoton Imaging

We present results of parametric studies for imaging photon fluxes of tens to hundreds of photons/cm2/sec requiring sensitive design and methodological parameters to obtain consistent image quality over a large range of fields of view.
Control of molecular weight distribution of petroleum pitches via multistage supercritical extraction

Abstract Packed-column supercritical extraction (SCE), followed by low-pressure gas stripping, was used to produce a dimer-rich pitch fraction from an oligomeric petroleum pitch, Marathon M-50, of broad molecular weight distribution (MWD). Both solvent-to-pitch ratios (S/P) >5 and a positive retrograde temperature gradient of 380–330 °C at 70 bar were found to reduce significantly the amount of trimer+ oligomers in the overhead product from the SCE column. This monomer- and dimer-rich overhead was subsequently stripped of monomer with gaseous toluene in a second packed column at 380 °C and 1.5 bar to obtain an 80+ mol% dimer product with an overall yield, based on the original feed, of 30%. To our knowledge, this is the first reported fractionation of a dimer-rich cut from a petroleum pitch with a demonstrably low level of both lower and higher mol wt impurities.
The osmotic response of the isolated, unfixed mouse tectorial membrane to isosmotic solutions: effect of Na+, K+, and Ca2+ concentration.

Abstract Changes in the size, shape, and structure of the isolated tectorial membrane (TM) of the mouse were measured in response to isosmotic changes in the ionic composition of the bathing solution. Substitution of artificial perilymph (AP) for artificial endolymph (AE) caused a small (≈ 1%) shrinkage of the TM's thickness. This substitution alters not only the predominate cation (from K + to N + ) but also the Ca 2+ concentration (from 20 μmol/1 to 2 mmol/1). When the predominate cation was changed from K + to Na + , while holding Ca 2+ concentration constant, results depended on Ca 2+ concentration: there was a small (≈ 1%) swelling for 20 μmol/1 Ca 2+ , larger (≈ 14%) swelling for lower ( 2+ , and little response for 2 mmol/1 Ca 2+ or for solutions containing the Ca 2+ chelator EGTA. Addition of Ca 2+ while holding the predominate cation constant caused shrinkage of the TM; both removal of Ca 2+ and addition of the Ca 2+ chelator EGTA caused swelling. Swelling responses were largely reversible if the magnitude of the swelling was small. Responses greater than a few percent were only partially reversible and caused long-lasting changes. Changes in ionic composition of the bath affected not only the thickness of the TM but also its other dimensions. Solution changes that increase TM thickness tend to cause radial shearing motions of the surfaces of the TM, which are accompanied by small decreases in width. Little change in length was observed. Although the responses were non-isotropic, increases in thickness were highly correlated with increases in volume. Swelling of the TM was also accompanied by a reduction in prominence of its radially oriented fibrillar structure. These results for the isolated TM of the mouse are qualitatively similar to those obtained previously for the isolated chick TM (Freeman et al., 1994) but different from those obtained for the in vitro mouse TM (Kronester-Frei, 1979a).
Metastevia (Compositae: Eupatorieae): A new genus from Mexico

A new genus and species from Mexico,Metastevia hintonii, is described. The genus, considered to be closely related to and derived fromStevia, differs in seven morphological features from all known species ofStevia. The reasons for recognizing the new genus are discussed in detail.
Testicular Weights, Ductus Deferens Semen Volumes, and Sperm Concentration of Turkeys with High and Low Ejaculate Volumes

Abstract Studies were conducted to determine if high and low ejaculate volumes were associated with differences in testicular weight and ductus (d.) deferens semen volumes. Mature male breeder turkeys were classified as low (≤.22 ml) or high (>.30 ml) semen producers. One week after or immediately after the last semen collection the turkeys were killed, testes weighed, and d. deferens and ejaculate semen volumes and sperm concentrations determined. Comparisons of low (LSP) and high (HSP) semen producers showed no differences in testes weights and sperm concentration in d. deferens. However, LSP turkeys had a lower volume of semen in the d. deferens and ejaculated a lower percentage of that volume than did HSP turkeys (P
Eponemycin analogues: syntheses and use as probes of angiogenesis

Abstract Derivatives of the epoxy-β-aminoketone containing natural product eponemycin have been prepared in order to study the molecular mode of action of this anti-angiogenic compound. Synthesis and use of a biotinylated dihydroeponemycin analogue demonstrated that dihydroeponemycin forms a covalent adduct with at least two intracellular proteins in human endothelial cells. Pretreatment of cells with a five equivalent excess of dihydroeponemycin precluded biotin-dihydroeponemycin binding indicating a specific interaction between natural product and the target proteins. This biotin-dihydroeponemycin derivative will prove useful in the purification and identification of eponemycin receptors.
The Larval Development of the Jonah Crab, Cancer Borealis Stimpson, 1859, Under Laboratory Conditions (Decapoda Brachyura)

[Die vollstandige Larvalentwicklung von Cancer borealis vom Ei bis zum ersten Krabbenstadium wurde bei 20° C und 30‰ Salinitat im Labor observiert. Die funktionellen Extremitaten samtlicher funf Zoeae und der Megalopa werden beschrieben und abgebildet. Die Larvalstadien von C. borealis werden mit denen von C. irroratus verglichen, welche Art ebenfalls in Narragansett Bay vorkommt. Wahrend ihre ganze Entwicklung erfordern die Larven beider Arten verschiedene Temperaturen fur eine optimale Ueberlebung, sie zeigen aber nur geringfugige Variation morphologischer Merkmale. Die morphologischen Kennzeichen, die fur die Larven von C. borealis im Vergleich zu denen von C. irroratus beschrieben werden, konnen fur die Unterscheidung der Larvalstadien beider Arten behilflich sein., Die vollstandige Larvalentwicklung von Cancer borealis vom Ei bis zum ersten Krabbenstadium wurde bei 20° C und 30‰ Salinitat im Labor observiert. Die funktionellen Extremitaten samtlicher funf Zoeae und der Megalopa werden beschrieben und abgebildet. Die Larvalstadien von C. borealis werden mit denen von C. irroratus verglichen, welche Art ebenfalls in Narragansett Bay vorkommt. Wahrend ihre ganze Entwicklung erfordern die Larven beider Arten verschiedene Temperaturen fur eine optimale Ueberlebung, sie zeigen aber nur geringfugige Variation morphologischer Merkmale. Die morphologischen Kennzeichen, die fur die Larven von C. borealis im Vergleich zu denen von C. irroratus beschrieben werden, konnen fur die Unterscheidung der Larvalstadien beider Arten behilflich sein.]
Synthesis of des-n-tetramethyltriostin a from C-terminal Z-d-serine tetra-and octadepsipeptide intermediates

Abstract Des-N-tetramethyltriostin A (1), a known DNA-intercalation agent, has been synthesized from tetra- and octapeptide intermediates that have Z- d -serine at the C-terminal position. The procedure thus allows the fragment coupling and cyclization reactions leading to the synthesis of the title compound to occur without racemization at the C-terminal amino acid. Esterification of Boc-Val-OH with the p-bromophenacyl ester of Z- d -serine provided didepsipeptide Z- d -Ser(Boc-Val)-OBpa (4). Stepwise addition of the requisite amino acids provided tetradepsipeptide Z- d -Ser[Boc-Ala-Cys(Acm)-Val]-OBpa (6). Fragment coupling of the respective C- and N-deprotected tetradepsipeptides 7 and 8, derived from 6, furnished linear octadepsipeptide 9, which upon cyclization and disulfide formation gave the bicyclic octadepsipeptide 11, a known synthetic precursor to 1. The degree of racemization incurred in the alanine and valine residues of selected depsipeptides was measured and the results compared with those obtained in previous studies. It was concluded that alanine, perhaps because of sequence effects, undergoes a degree of racemization (4–10%) during hydrolysis of tetradepsipeptide 6 and octadepsipeptide 9.
Finite amplitude waves in two-dimensional lined ducts

A second-order uniform expansion is obtained for nonlinear wave propagation in a two-dimensional duct lined with a point-reacting acoustic material consisting of a porous sheet followed by honeycomb cavities and backed by the impervious wall of the duct. The waves in the duct are coupled with those in the porous sheet and the cavities. An analytical expression is obtained for the absorption coefficient in terms of the sound frequency, the physical properties of the porous sheet, and the geometrical parameters of the flow configuration. The results show that the nonlinearity flattens and broadens the absorption vs. frequency curve, irrespective of the geometrical dimensions or the porous material acoustic properties, in agreement with experimental observations.
Distribution of Cone Orientations as an Explanation of the Stiles-Crawford Effect

The retinal directional effect of several subjects was measured. Flicker brightness matches were made using monochromatic lights. The experiment was performed in two parts. The first measured the Stiles–Crawford effect across only the central 6 mm of the pupil. Objective statistical methods were used to derive the best-fitting parabolas by least-squares criteria. Variances of the data were calculated from the replications and indices of goodness of fit were derived. On these grounds, the parabola was found to be unacceptable. The second part of the experiment included replicate matches made at points across the entire width of the dilated pupil. Similar methods were again used to derive the best-fitting gaussian and parabolic functions. The gaussian proved to be statistically acceptable as a description of the change of brightness with position of pupil entry while the parabola did not. The consequences of accepting the gaussian function are far-reaching. It is argued that the shape of the Stiles–Crawford-effect curve as measured across the pupil is the result of the normal distribution of cone angulations, each cone having inherent directional sensitivity. It follows from this that the directional sensitivity of individual cones cannot be as broad as the observed Stiles–Crawford-effect curve. It is probable that the individual cone will accept energy incident upon it within only a very small angle from its long axis.
670 PHARMACOLOGIC AND MECHANICAL PROPERTIES OF COLON IN A MODEL OF HIRSCHPRUNG'S DISEASE

In the mouse the Ls trait is an autosomal recessive allele, that when present in the homozygous Ls/Ls condition, causes a segment of distal colonic aganglionosis resulting in obstruction similar to Hirschsprung's disease. Circular muscle rings from the aganglionic (AGC) and the ganglionic colon (GC) of Ls/Ls mice and from corresponding segments of control mice, were tested in vitro. 1) Electrical field stimulation caused neurally mediated relaxation followed by contraction in GC of both Ls/Ls and control mice while the AGC of Ls/Ls mouse did not respond. 2) AGC responded to direct acting myogenic agents and, in some instances, at lower doses than the GC. AGC was super-sensitive to Vasoactive Intestinal Peptide (VIP) and bethanechol but not to isoproterenol and ATP. 3) The maximal active force generated by the colon from the Ls/Ls mouse was significantly greater in rings from both the GC and A6C than in control mice. 4) Circular muscle thickness and stress, i.e. maximal active force normalized for the amount of muscle present, were greater in both the GC and AGC of Ls/Ls mouse than in control mice. 5) Isolated muscle cells, obtained by in vitro digestion with collagenase and examined with phase contrast microscopy, were significantly longer in GC of Ls/Ls mouse than in the corresponding segment of control colon (119.9 vs. 83.1 μm). We conclude: the colon in this Hirschprung model generates greater forces because of greater circular muscle thickness and stress. These changes may be a reflection of the greater cell size. Increased sensitivity to bethanechol and VIP may represent “denervation” supersensitivity and support the hypothesis that VIP may be an endogenous neurotransmitter responsible for inhibition of normal colon.
Influence of animal diet and muscle location on cholesterol content of beef and pork muscles.

Muscles at three different anatomical locations from carcasses of 12 pigs and 12 steers that were fed diets with varying levels of oleic acid-pigs in the form of canola oil at levels of 0, 10 and 20% and steers in the form of canola rapeseed at levels of 0 and 20%-were analyzed for cholesterol concentrations. The cholesterol level of beef or pork muscles was not significantly affected by the animal diet modification. For each animal species, muscles at different anatomical locations were similar in cholesterol content. Beef and pork muscles were not significantly different in cholesterol content.