cssi/SciSciGPT-SciSciNet huggingface dataset:
An assembly domain of the Rous sarcoma virus Gag protein required late in budding.

Abstract The Gag protein of Rous sarcoma virus has the ability to direct particle assembly at the plasma membrane in the absence of all the other virus-encoded components. An extensive deletion analysis has revealed that very large regions of this protein can be deleted without impairing budding and has suggested that the essential functions map to three discrete regions. In the studies reported here, we establish the location of assembly domain 2 (AD2) within the proline-rich p2b sequence of this Gag protein. AD2 mutants lacking the p2b sequence were completely defective for particle release even though their Gag proteins were tightly associated with the membrane fraction and exhibited high levels of protease activity. Mutations that inactivate the viral protease did not restore budding to wild-type levels for these mutants, indicating that the defect is not due simply to a loss of protease regulation. AD2 mutants could be rescued into dense particles in genetic complementation assays, indicating that their defect is not due to a gross alteration of the overall conformation of the protein and that the assembly function is not needed on every Gag molecule in the population. Several mutants with amino acid substitutions in the p2b sequence were found to have an intermediate capacity for budding. Inactivation of the protease of these mutants stabilized the Gag polyprotein within the cells and allowed an increase in particle release; however, the rate of budding remained slow. We favor the idea that AD2 is a dynamic region of movement, perhaps serving as a molecular hinge to allow the particle to emerge from the surface of the cell during budding.
Cardiovascular alterations in severe pregnancy-induced hypertension: acute effects of intravenous magnesium sulfate.

The central hemodynamic effects of intravenous magnesium, sulfate were studied in five patients with severe pregnancy-induced hypertension. All five patients had a Swan-Ganz and a radial artery catheter placed prior to initiation of magnesium sulfate therapy. Four grams of magnesium sulfate was given over 15 minutes followed by a continuous infusion of 1.5 gm per hour. There was a 12.5% increase in cardiac index immediately after the infusion but cardiac index returned to pretherapy values by 15 minutes after infusion. The mean arterial pressure was significantly (p
An explicit characterization of the convex envelope of a bivariate bilinear function over special polytopes

In this paper, we constructively derive an explicit characterization of the convex envelope of a bilinear function over a special type of polytope in ℝ2. Our motivation stems from the use of such functions for deriving strengthened lower bounds within the context of a branch-and-bound algorithm for solving bilinear programming problems. For the case of polytopes with no edges having finite positive slopes, that is polytopes with “downward” sloping edges (which we call D-polytopes), we obtain a direct, explicit characterization of the convex envelope. This case subsumes the analysis of Al-Khayyal and Falk (1983) for constructing the convex envelope of a bilinear function over a rectangle in ℝ2. For non-D-polytopes, the analysis is more complex. We propose three strategies for this case based on (i) encasing the region in a D-polytope, (ii) employing a discretization technique, and (iii) providing an explicit characterization over a triangle along with a triangular decomposition approach. The analysis is illustrated using numerical examples.
Simple technique for the accurate design of square bandpass WDM interference filters

Narrow bandpass optical interference filters that precisely meet arbitrary Chebychev (equiripple) or maximally flat specifications are designed by refractive index refinement of standard multicavity filters, combined with straightforward manipulations of the solutions. The filters are composed mostly of quarter-wave (QW) layers of two materials. A few non-QW tuning layers are introduced in regions of the multilayer stacks that have a low sensitivity to deposition errors in order to control the passband ripple and halfwidth. Multiple solutions with exactly the same passbands are easily generated, from which those that have the best chance of being successfully fabricated can be selected.
Scholarly Privileges: Their Roman Origins and Medieval Expression

THE conferring of academic degrees to the accompaniment of the phrase, "with a11 the rights, privileges, and immunities, thereunto pertaining," has become so commonplace a proceeding in American colleges and universities that the significance of the accompanying phrase is lost to view. Otherwise this bestowal of peculiar rights, privileges, and immunities upon university graduates, who would thus be set apart from the ordinary run of the population, would be denounced as an allachronism in an age of equalitarian ideals. However, the continued use of these terms, now so obsolete in their practical application, illustrates cogently the persistent force of tradition, even in a world of rapid physical and material change. Such verbal symbols of a bygone era preserve at least the memory of a past in which such rights, privileges, and immullities were the usual concomitants of the scholarly status. They may also serve to whet our curiosity as to their nature and history. The history of the rise, development, and decline of these scholarly rights and privileges is such a long and varied one and is so intimately bound up with the social and political events of the centuries which saw their development and decline that an adequate historical account of them would require a much more extensive consideration than is here possible. Nevertheless, in anticipation of the fuller treatment which the history of these rights and privileges merits, current interest in them would appear to justify a brief summary of their Roman origins and of some instances of their expression in Europe in the Middle Ages, the time of their fullest development.1 In origin, scholarly privileges may be traced back to specifie provisions in the body of Roman law. The concept that scholars, particularly those who were masters of liberal arts-grammar and rhetoric-together with physicians who were concerned with the healing of the sick, merited special privileges and immunities at the hands of the Roman state was already well es-
Recent Results In The Application Of Electron Beam Direct-Write Lithography

The Perkin-Elmer AEBLE 150 e-beam lithography tool for direct writing on wafers has been installed in several different manufacturing environments. These include prototyping of silicon DRAMs, device development, GaAs production, high-resolution advance device, and full custom ASICs. This paper describes the application of Perkin-Elmer's AEBLE 150 from a large geometry ASIC high wafer throughput requirement, which includes personalization of metal and via layers, to the sub-0.2 μm high-resolution GaAs device. Electron beam personalization of metal and via layers for ASIC devices is advantageous for several reasons: 1) The versatility of the AEBLE 150 allows efficient mixing with optical lithography product lines. 2) The intrinsic machine overlay capability (0.15 μm) has been approached by the observed 0.25 μm overlays with wafers taken from product lots not originally designed for mixing of lithography tools. 3) This maskless technique provides cost savings for small lots where relatively few devices are required. 4) Commercially available resists have been used with good process and throughput performance for devices with 1 μm minimum spaces. For GaAs applications, resolution of 0.25μm or better is required to produce GHz devices. The resolution limit of the AEBLE 150 was investigated with the result that 0.15 μm gates are reliably produced in 0.5 μm thick PMMA over GaAs substrates.
Office Management of Peripheral Arterial Disease

Patients with peripheral arterial disease are at increased risk for all-cause mortality, cardiovascular mortality, and mortality from coronary artery disease. Smoking should be stopped, and hypertension, diabetes mellitus, and dyslipidemia should be treated. Statins reduce the incidence of intermittent claudication and increase exercise duration until the onset of intermittent claudication in patients with peripheral arterial disease and hypercholesterolemia. Antiplatelet drugs, such as aspirin or clopidogrel, angiotensin-converting enzyme inhibitors, and statins, should be given to all patients with peripheral arterial disease. Beta-blockers should be given if coronary artery disease is present. Exercise rehabilitation programs and cilostazol improve exercise time until the onset of intermittent claudication. Indications for lower-extremity angioplasty, preferably with stenting, or bypass surgery are incapacitating claudication interfering with work or lifestyle in patients; limb salvage in patients with limb-threatening ischemia as manifested by rest pain, nonhealing ulcers, infection, or gangrene; and vasculogenic impotence.
Is there an alternative to the cytoplasmic receptor model for the mechanism of action of steroids

Abstract The essential features of the cytoplasmic receptor model for the mechanism of action of steroids are summarized and the restrictions imposed by such a model are noted. The literature which is not compatible with these restrictions is reviewed, and the necessity for a more general model discussed. A model for the mechanism of steroid action is proposed in which both specificity and saturability of binding in target tissue is both a function of cytoplasmic receptors and nuclear acceptors.
Uranus' rotational period

A modified spectroscopic technique was applied to determine the rotational period of Uranus and the orientation of the projected spin axis of the planet. The method consists in obtaining a series of spectra for both a nonrotated planet disk and for a disk rotated 180 degrees. Ignoring the effects of seeing in analyzing the spectra for no rotation of the disk leads to a lower limit on the period, and for a disk rotated 180 degrees, ignoring the seeing in the modeling of the spectra leads to an upper limit on the period. When blurring from seeing and guiding errors are added to the modeling for both image orientations and the model spectra are compared to the observations, both the period and the degree of blurring are obtained simultaneously. The results gave a period of rotation of Uranus 23 + 5 or - 2 hr.
Contraction frequency modulates muscle fatigue and the rate of myoglobin desaturation during incremental contractions in humans

The metabolic cost of force production, and therefore the demand for oxygen, increases with intensity and frequency of contraction. This study investigated the interaction between fatigue and oxyge...
Algebraic structure of linear and non-linear models of open quantum systems

Abstract We show that all the linear and nonlinear evolution equations proposed so far for the density operator of open quantum systems admit a common algebraic structure in the form of a generalized commutator, which is the nonassociative product of a Lie-admissible algebra.
Effect of linear alcohol molecular size on the self-assembly of fullerene whiskers

Abstract The recent development of self-assembled fullerene whiskers and wires has created an enormous potential and resolved a serious challenge for utilizing such unique class of carbon material in advanced nano-scale, molecular-based electronic, optical, and thermal devices. In this paper we investigate, the self-assembly of C60 molecules into one-dimensional whiskers using a series of linear alcohols H(CH2)nOH, with n changing from 1 (methanol) to 3 (isopropyl alcohol), to elucidate the effect of alcohol molecular size on the size distribution of the self-assemble fullerene whiskers. Our results show that the length of the produced fullerene whiskers is affected by the molecular size of the alcohol used in the process. The crucial role played by solvent/alcohol interaction in the assembly process is discussed. In addition, Raman spectroscopy measurements support the notion that the self-assembled whiskers are primarily held by depletion forces and no evidence of fullerene polymerization was observed.
A novel separate lateral confinement quantum well heterostructure laser

Summary form only given. In the lateral dimension of a semiconductor laser, a single structure is usually used to confine both carriers and the optical mode, as in buried heterostructure (BH) or ridge waveguide (RW) lasers. The BH exhibits threshold current densities half that of RW lasers due to strong lateral carrier confinement. However, due to the large index step created by the lateral heterostructure, the BH must be made very narrow (typically <2 /spl mu/m) to cutoff propagation of undesired higher order lateral modes. A narrow device has several disadvantages including: a smaller available gain volume, higher optical power densities at the facets, larger diffraction angles of the emitted beam, and more stringent process control requirements. One proposal that has been successfully implemented to mitigate these problems is to flare the waveguide near the facet to allow the mode to expand laterally. In our specific implementation, the optical mode is confined by a 3.5 /spl mu/m etched ridge waveguide (RW), which is centered over a wider BH. The RW is used to make a wide single mode index guide, while the BH laterally confines the carriers.
User experience: collaboration systems and technology

The Hawaii International Conference on System Sciences (HICSS) has a long history of supporting evolving areas of research, such as groupware, group support systems and knowledge management and the nurturing of these new concepts and ideas. The papers in this session describe efforts in facilitation, ontology development, sharing information, experiments, field studies, work flow, process design, planning and development of practical guidelines for collaboration systems and knowledge management. The papers and speakers in these sessions bring insight and lessons leaned from their experiences with real world problems. The GroupSystems software will be available throughout the sessions to identify research questions and opportunities for further study.
Broadband Electrical Characterization of Multiwalled Carbon Nanotubes and Contacts

The electrical response of an individual multiwalled carbon nanotube (MWNT) and its contacts, welded to a coplanar waveguide (CPW), was measured up to 24 GHz using a technique that removes environment effects. This is the first time MWNT contact effects have been systematically isolated from the CPW. Each contact response was quite different and also showed a pronounced sensitivity to ambient light. Adding more contact material clearly changed the high-frequency electrical response and the sensitivity to light.
Risk factors for chronic rejection in pediatric renal transplant recipients--a single-center experience.

Chronic rejection (CR) is the most common cause of graft loss beyond the 1st posttransplant year. The aim of this analysis was to identify the risk factors for the development of CR in pediatric renal transplant recipients. Between June 1984 and March 1994, 217 renal transplants were performed in children at our center. Immunosuppression included prednisone, azathioprine, cyclosporine (CsA), and prophylactic antibody. Using multivariate analysis, we studied the impact of the following variables on the development of biopsy-proven CR: age at transplant ( 5 years), gender, race, transplant number (primary, retransplant), donor source (cadaver, living donor), donor age ( 49 years), number of ABDR mismatches (0, 1-2, 3-4, 5-6), number of DR mismatches (0, 1, 2), percentage peak panel reactive antibody (PRA) ( 50%), percentage PRA at transplantation ( 50%), dialysis pretransplant, preservation time > 24 h, acute tubular necrosis requiring dialysis, initial CsA dosage ( 5 mg/kg per day), CsA dosage at 1 year posttransplant ( 5 mg/kg per day), acute rejection (AR), number of AR episodes (ARE) (1, > 1), timing of AR ( 6 months), reversibility of AR (complete, partial), and infection [cytomegalovirus (CMV), non-CMV viral, bacterial]. Risk factors for the development of CR in pediatric renal transplant recipients were: AR (P 1 vs. 1) (P 50%) (P < 0.03, odds ratio 3.6).
84. Interaction of ozone with adsorbent charcoal

Abstract A kinetic study was made of the ozone-charcoal reaction at ambient temperature by two different experimental procedures. The depletion of ozone was monitored by ultra-violet absorption and the formation of carbon dioxide in flow experiments by infra-red. The sum of carbon dioxide and carbon monoxide, formed from the earliest stages of the reaction, was significantly retarded as the calculated monolayer of oxygen atoms was approached. The weight increases of a charcoal were directly related to the depletion of ozone after corrections were made for the gasification reactions. One atom of oxygen from the ozone molecule accounts for the mass balance in the overall ozonecharcoal reaction. No catalytic decomposition of ozone by the charcoal was indicated. A reaction mechanism is suggested that accounts for most of the observed behavior. Scanning electron micrographs are presented for an original and the ozone-treated coconut shell charcoal.
Siderophile geochemistry of ureilites : A record of early stages of planetesimal core formation

Abstract New bulk-compositional data, including trace siderophile elements such as Ir, Os, Au, and Ni, are presented for 25 ureilites. Without exception, ureilites have siderophile abundances too high to plausibly have formed as cumulates. Ureilites undoubtedly underwent a variety of “smelting,” by which C was oxidized to CO gas while olivine FeO was reduced to Fe-metal. However, pressure-buffered equilibrium smelting is not a plausible model for engendering the wide range (75–96 mol%) of mafic-silicate core mg among ureilites. The smelting reaction produces too much CO gas. Even supposing a disequilibrium process with the smelt-gas leaking out of the mantle, none of the ureilites, least of all the ureilite with the most “reduced” (highest) olivine-core mg (ALH84136), has the high Fe-metal abundance predicted by the smelted-cores model. In principle, the Fe-metal generated by smelting could have been subsequently lost, but siderophile data show that ureilites never underwent efficient depletion of Fe-metal. Ureilites display strong correlations among siderophile ratios such as Au/Ir, Ni/Ir, Co/Ir, As/Ir, Se/Ir, and Sb/Ir. Ureilite siderophile depletion patterns loosely resemble siderophile fractionations, presumably nebular in origin, among carbonaceous chondrites. However, Zn, for an element of moderate volatility, is anomalously high in ureilites. A tight correlation between Au and Ni extrapolates to the low-Ni/Au side of the compositional range of carbonaceous chondrites. From this mismatch, mild but nonetheless significant depletions of refractory siderophile elements such as Ir and Os, and moderate depletions of strongly siderophile, weakly chalcophile elements such as Ni and Au, we infer that the ureilite siderophile fractionations are largely the result of a non-nebular process, i.e., removal of S-rich metallic melt, possibly with minor entrainment of Fe-metal. Several lines of trace-element evidence indicate that melt porosity during ureilite anatexis was at least moderate. The ureilite pattern of very mild depletions of extremely siderophile elements, but much deeper depletions of moderately siderophile, chalcophile elements, suggests that asteroidal core formation probably occurs in two discrete stages. In general, separation of a considerable proportion (several wt%) of S-rich metallic melt probably occurs long before, and at a far lower temperature than, separation of the remaining S-poor Fe-metal. Apart from the Fe-metal itself, only extremely siderophile elements wait until the second stage to sequester mainly into the core.
Reachability of Chaotic Dynamic Systems

This work focuses on the ability of any feedback approach to control a given chaotic system. The concept of reachability for nonlinear systems is presented in a differential geometric framework. This concept is used to examine the ability of any perturbation signal to redirect the system's trajectory flow within its phase space. The structure of the controlling input and its global relation to the underlying dynamics of the system are crucial for the ability to effectively control the system within the phase space. The concepts are illustrated on a well known example: the Lorenz system.
Stabilization of an anthrapyrazole antitumour agent, DuP 937, on complexation with heptakis(2,6-di-O-methyl)-β-cyclodextrin in aqueous solution

DuP 937, an anthrapyrazole antitumour agent that is chemically unstable in aqueous solution, was shown, by absorption spectroscopy, to form an inclusion complex with heptakis(2,6-di-O-methyl)-beta-cyclodextrin (DM beta CD) in aqueous solution. Proton nuclear magnetic resonance spectroscopy was used to determine the stoichiometry and association constant of the complex. The 1:1 stoichiometry of the complex was established by the continuous variation method by following changes in the chemical shifts of aromatic protons of DuP 937. The complex association constants determined by different techniques used in this study were in the same order of magnitude. The kinetics of degradation of DuP 937 in aqueous solution were investigated as a function of DM beta CD concentration at pH 5.5 and 60 degrees C. The results indicated about a seven-fold increase in the stability of DuP 937 in the presence of DM beta CD in aqueous solution.
Moscow and Nicaragua: Two sides of soviet policy

Abstract Moscow's pragmatic and methodical cultivation of the Sandinista regime reflects a desire to consolidate the leftist government in Nicaragua without provoking either U.S. retaliatory countermeasures against Managua or more importantly, Cuba—the USSR's most important equity in the Western Hemisphere. The Soviets have utilized their East European and Cuban allies to play down and obscure the extent of Moscow's interest in and involvement with the Sandinista regime. While Moscow continues to maintain a low profile, the initiation of oil deliveries to Nicaragua and authoritative statements of Soviet interest and concern over Managua's economic and military dilemmas suggest that the USSR may be prepared to increase its efforts to sustain the Sandinistas in power.
Interaction of HIV-1 Integrase with DNA Repair Protein hRad18

We have previously shown that human immunodeficiency virus-1 (HIV-1) integrase is an unstable protein and a substrate for the N-end rule degradation pathway. This degradation pathway shares its ubiquitin-conjugating enzyme, Rad6, with the post-replication/translesion DNA repair pathway. Because DNA repair is thought to play an essential role in HIV-1 integration, we investigated whether other molecules of this DNA repair pathway could interact with integrase. We observed that co-expression of human Rad18 induced the accumulation of an otherwise unstable form of HIV-1 integrase. This accumulation occurred even though hRAD18 possesses a RING finger domain, a structure that is generally associated with E3 ubiquitin ligase function and protein degradation. Evidence for an interaction between integrase and hRad18 was obtained through reciprocal co-immunoprecipitation. Moreover we found that a 162-residue region of hRad18 (amino acids 65–226) was sufficient for both integrase stabilization and interaction. Finally, we observed that HIV-1 integrase co-localized with hRad18 in nuclear structures in a subpopulation of co-transfected cells. Taken together, these findings identify hRad18 as a novel interacting partner of HIV-1 integrase and suggest a role for post-replication/translesion DNA repair in the retroviral integration process.
Rationale and design of the cardiac hospitalization atherosclerosis management program at the University of California Los Angeles

Abstract Despite clear and consistent clinical-trial evidence that secondary-prevention medical therapies reduce mortality in patients with established coronary artery disease, these therapies are underutilized in patients receiving conventional care. To address this issue, a Cardiac Hospitalization Atherosclerosis Management Program (CHAMP) focused on initiation of aspirin, cholesterol-lowering medication (3-hydroxy-3-methylglutaryl-coenzyme A [HMG-CoA] reductase inhibitor titrated to achieve low-density lipoprotein [LDL] cholesterol
Surgical treatment of 70 patients with brain metastases from breast carcinoma

BACKGROUND Brain metastases are diagnosed in 15% of patients with metastatic breast carcinoma. Most patients are treated with whole-brain radiotherapy (WBRT) and/or chemotherapy. The information on surgical results is sparse. METHODS Among 709 patients with tumors metastatic to the brain who underwent craniotomy at Memorial Hospital, New York, New York, between January 1974 and December 1993, 70 (10%) had a primary breast carcinoma. Their treatment outcomes were analyzed retrospectively. RESULTS The median age at diagnosis of primary breast carcinoma and brain metastasis was 46 and 50 years, respectively. All but two patients had metachronous diagnoses of breast carcinoma and brain metastasis. The median interval between both diagnoses in this subgroup was 28 months. In all 70 patients, the overall median survival was 54 months after diagnosis of the primary breast tumor and 16.2 months after diagnosis of the brain tumor. Only 5 patients (7%) were alive at last follow-up. The overall median survival after brain surgery was 14 months. Four patients died within 30 days of craniotomy. Twelve patients had a solitary cerebellar metastasis and 16 had multiple metastases; their median survival was 10.9 months and 14.8 months, respectively. There was no statistical difference in survival for patients who had single or multiple lesions. The median survival of 22 patients with positive hormonal receptor (estrogen receptor [ER] or progesterone receptor [PR]) was significantly longer than the median survival of 20 patients with negative ER/PR (21.9 vs. 12.5 months, P 50 years had survival of 17.3 and 11.1 months, respectively (P = NS). Neurologic deficit prior to craniotomy shortened survival for 24 patients to 11.5 months, compared with 17.4 months for patients without deficit (P = NS). Fifteen patients experienced failure with WBRT prior to undergoing craniotomy, and their median survival was shorter than for those who underwent craniotomy as the initial treatment (6.3 vs. 15.8 months, P < 0.03). However, their survival after diagnosis of brain metastasis was not significantly different (19.2 vs. 16.1). Forty-seven patients received WBRT postoperatively, and 9 patients did not receive adjuvant radiation therapy. Subsequent relapse in the brain was diagnosed in 27 patients, and 8 of them underwent reresection. One-year, 2-year, 3-year, and 5-year survival rates were 53%, 25.7%, 18.6%, and 7%, respectively. In multivariate analysis, the adjuvant WBRT after craniotomy and the absence of meningeal carcinomatosis were the only significant predictive variables for longer survival. CONCLUSIONS In a subset of selected patients, craniotomy followed by WBRT can positively impact survival. Cancer 1997; 80:1746-54. © 1997 American Cancer Society.
Method for Measuring the Temperature Dependence of the Henry's Law Constant of Selected Polycyclic Aromatic Hydrocarbons

Abstract The Henry's Law Constant (HLC) is an important thermodynamic constant needed to model air-water exchange of contaminants such as polycyclic aromatic hydrocarbons (PAHs). However, few direct HLC measurements have been reported for PAHs. A gas-stripping apparatus was constructed to allow gaseous and dissolved phase PAH concentrations to be measured over time. HLC was calculated by two methods: measuring PAH loss in the dissolved phase over time and dividing the instantaneous air by dissolved phase concentrations. Both methods yielded similar HLC values that were comparable to the range of HLCs reported in the literature.
Luminescence lifetimes of aqueous europium perchlorate, chloride and nitrate solutions

Abstract The sensitivity of the half life of Eu(II) luminescence to changes in electrolyte concentration has been studied. The values of n , the hydration number, were calculated and found to increase for HClO 4 , LiClO 4 and NaClO 4 solutions and to decrease for NaCl and LiNO 3 solutions as the concentrations were increased. In HCl solution, n increased with concentration to 5 M, then decreased. These observations are discussed in terms of models of outer vs. inner sphere complexation and of increased interaction of the primary hydration sphere with the Eu(II) cation.
Detection of retinoid receptor expression patterns in canine normal lymph nodes and in nodal lymphomas

Introduction: Retinoids are derivatives of vitamin A, which are essential for cell growth and differentiation of a variety of cells. Retinoid activity occurs after binding to a class of nuclear receptors termed retinoic acid receptor (RAR) and retinoid X receptor (RXR). Receptor-ligand interactions ultimately activate the transcription of target genes. Retinoids have been shown in vitro to participate in both lymphocyte activation and apoptosis. In human cancer patients, specific ligands to retinoid receptors have been approved for the treatment of T-cell cutaneous lymphomas. The use of retinoids for the treatment of additional lymphoid malignancies, both of B and T-cell types, has been speculated. In vitro experiments demonstrating lymphocyte apoptosis subsequent to treatment with both natural and synthetic retinoids further support the potential utility of retinoid therapy in spontaneous lymphoid malignancies. Objectives: To detect the pattern of retinoid receptor expression (RAR and RXR) and their isoforms (α, β, and γ) in normal lymph nodes and in nodal lymphomas in dogs. Methods: Immunohistochemistry was performed in tissue specimens derived from naturally occurring cases of nodal lymphomas and normal lymph nodes from dogs. Rabbit polyclonal antibodies (Santa Cruz Biotechnology), previously demonstrated to be cross-reactive with canine tissue, were utilized to assess the expression patterns of RAR/RXR and their respective isoforms (α, β, and γ) in all pathologic and normal tissue samples evaluated. Results: Normal lymph nodes were consistently negative for all isoforms. In hyperplastic nodes, macrophages were positive for all isoforms. Lymphomas both of B and T-cell type stained strongly positive for the isoforms RARα and RXRγ. Conclusions: A distinctive pattern of expression between lymphomas, lymphoid hyperplasia, and normal lymph nodes was detected in dogs. Different retinoid receptor expression profiles from normal lymph nodes and nodal lymphomas seem to be of diagnostic importance. Further investigation with larger number of lymphoma cases is warranted to thoroughly characterize retinoid receptor expression patterns in lymphoid malignancies with the possibility of using specific retinoid receptor ligands for the treatment of canine nodal lymphomas.
CORRECTION OF LIGHT ATTENUATION IN LARGE SHOWER COUNTERS.

Abstract A simple procedure, based on elementary shower theory, has been devised to compensate for attenuation losses over the surface of large sandwich-type shower counters. It uses tapered lead sheets in place of the usual flat plates and is capable of compensating for attenuation of as much as a factor of two.
Brownian motion with restoring drift: Micro-canonical ensemble and the thermodynamic limit

We take up the old problem of micro-canonical conditioning in the context of diffusion. Starting with a potential \(\), the Schrodinger operator \(\) with ground state \(\) is carried by a conjugation into the diffusion generator \(\) with invariant density \(\). The latter motion \(\) is made micro-canonical by first conditioning the path to be periodic, \(\), and then further conditioning on the empirical mean-square or ``particle number'' \(\). The thermodynamics are then studied by taking \(\) while D remains fixed. The problem in this form owes its inception to McKean-Vaninsky \cite{MV2} who obtained the following result. For \(\) with \(\), they showed the same type of diffusion appears in the thermodynamic limit, but with drift arising from the shifted potential \(\) being such that the limiting mean-square equals D. Their method of proof predicts the same outcome for \(\), so long as D is smaller than the canonical mean-square \(\), while if \(\), the matter was unresolved. The purpose of this note is to show a type of phase transition takes place in this case: the conditioning is overcome in the limit and one sees the original (stationary) diffusion on the line. The proof employs an entropy inequality due to Csiszar [1].
A Wiki that knows where it is being used: insights from potential users

With the advent of extensive wireless networks that blanket physically compact urban enclaves such as office complexes, shopping centers, or university campuses, it is possible to create software applications that provide location-based mobile/online services. One such application is CampusWiki, which integrates location information into a wiki structure. In the design science research reported in this paper, we employed a form of "action research" in which we engaged users as participants in an iterative process of designing and evaluating CampusWiki. Two qualitative studies were undertaken early in the design process in which semi-structured interviews were used to assess potential users' reactions to CampusWiki. Through this research, the designers were able to assess whether their intentions matched the mental models of potential users of the application. The results showed that although many of the perceived benefits were as designed by the developers, a misunderstanding of the location-aware feature led users to unanticipated concerns and expectations. These findings are important in guiding designers and implementers on the desirable and possibly undesirable features of such systems.
Incomplete charge transfer stability of organic donor-acceptor compounds

The conditions required to establish the stability of incomplete charge transfer in the ground state of a 1:1 segregated-stack organic compound have been examined for a system involving finite-transfer integral between nearest-neighbor molecules along the donor and acceptor stacks. Molecular ionization energy, crystalline Madelung energy, as well as band or delocalization energy have been included. The three cases investigated, namely, no correlation between electrons on a stack, strong on-site correlation as well as strong nearest-neighbor correlation suggest that correlation between electrons (holes) on the same stack is important in establishing incomplete charge transfer in an organic compound such as TTF-TCNQ (tetrathiafulvalenium-tetracyanoquinodimethanide).
The prevalence of neural tube defects among ethnic groups in Brooklyn, New York.

Abstract Records of almost 174,000 consecutive births at six Brooklyn hospitals during the years 1968–1976 were reviewed for congenital neural tube defects. Prevalence of anencephaly, myelomeningocele and occipital encephalocele combined was significantly higher in infants delivered to mothers born in Puerto Rico than in offspring of non-Puerto Rican whites or blacks. The association of prevalence rates with ethnicity remained significant after adjustment for several variables. However, when adjustment was made for private or service status the difference between Puerto Ricans and whites, although still appreciable, was no longer statistically significant. No significant differences in prevalence rates between whites and blacks were observed. Sex ratios of affected infants were close to unity in each ethnic group. Statistically significant associations were found between the prevalence of neural tube defects and parity, gravidity and economic status. The patterns of these associations varied among the ethnic groups. A declining trend in the prevalence of myelomeningocele was observed for all ethnic groups.
Closed dynamic contour models that split and merge

Classical dynamic contours (snakes) suffer from their inability to properly address the crossover problem. In the closed contour case, a part of the snake inverts and expands without bounds. This paper proposes a novel approach to handle inversions by splitting the contour at the points of self-intersection. Separated parts that are inverted are destroyed while the remaining parts are used to seed new snakes. Collisions of snakes cause them to merge. The probability of crossovers is further reduced by an efficient reparameterization procedure. The method is successfully applied to the challenging task of tracking the globule in a motion lamp.
Thioredoxin Regulates Adipogenesis through Thioredoxin-interacting Protein (Txnip) Protein Stability

Txnip (thioredoxin-interacting protein) is a critical mediator of metabolism and adipogenesis in vivo. The mechanisms of action of Txnip are believed to operate at least in part by inhibiting the redox signaling functions of thioredoxin. We tested here whether Txnip suppressed adipogenesis by inhibiting thioredoxin and discovered a reversal of roles; Txnip inhibits adipogenesis directly, and thioredoxin binding regulates Txnip by enhancing Txnip protein stability. Unlike Txnip, a Txnip mutant that cannot bind thioredoxin (C247S) did not prevent adipocyte differentiation, but was degraded more quickly by proteasomal targeting. Finding that endogenous Txnip protein is also rapidly degraded at the onset of adipogenesis suggested that Txnip degradation is required for adipocyte differentiation. Thioredoxin overexpression stabilized Txnip protein levels to inhibit adipogenesis, and adipogenic stimulants such as insulin promoted Txnip-thioredoxin dissociation to the more labile free Txnip state. As an α-arrestin protein, Txnip has two C-terminal tail PPXY motifs that mediate E3 ubiquitin ligase binding and Txnip protein stability. Mutating the PPXY motifs prevented Txnip degradation, even when thioredoxin binding was lost, and restored the ability of C247S Txnip to inhibit adipogenesis. These studies present a novel reconsideration of Txnip-thioredoxin signaling by showing that thioredoxin regulates the intrinsic function of Txnip as an inhibitor of adipogenesis through protein stabilization.
Non-universal critical behavior in the planar XY-model with fourth order anisotropy

Abstract We have used a Monte Carlo block distribution method to study the two-dimensional classical XY -model with a fourth-order anisotropy field h 4 . We find that T c varies only slowly with h 4 but that v depends strongly on h 4 .
Abstract 5411: Development of SCLC specific nanoparticle-mediated therapeutic gene delivery

Lung cancer is the most common cause of cancer-related deaths worldwide. Small cell lung cancer (SCLC) is a particularly aggressive form of lung cancer characterized by early metastatic behavior. Even with currently recommended therapy, the average survival of SCLC patients is less than 1 year. There is an urgent need for novel treatments. The majority (70-90%) of SCLC cases possess alterations in p53 and Rb. This relative genetic homogeneity makes SCLC an attractive context in which to develop and test novel gene therapy approaches. We have initiated studies using non-viral, poly-β amino acid ester (PBAE) nanoparticle delivery of gene therapy in SCLC. PBAE polymers possess numerous advantages over viral delivery systems such as structural diversity, cost effectiveness, low immunogenicity and higher stability. PBAEs encapsulate DNA to form biodegradable cationic nanoparticles and have been studied in a variety of cancer cell types and in primary endothelial cells. This is the first study of PBAEs in SCLC. A PBAE polymer library was screened in two SCLC lines using a luciferase-based high-throughput screen (HTS). Thirty-two of 112 polymers were further characterized in the H446 SCLC cell line using a CMV-GFP reporter construct and analyzed by qualitative (microscopy) and quantitative (flow cytometry) methods. This secondary screen revealed that the polymers had variable transfection efficiencies ranging from 8-55%. Four polymers, 446LG, 447LG, 456LG and 457 exhibited high transfection efficiencies (42-55%) in two SCLC cell lines, including one suspension line. Using PBAEs complexed with Cy5-labeled DNA, we were able to demonstrate that >90% cells bind and internalize the nanoparticles. We have initiated studies to better elucidate bottlenecks between nanoparticle uptake and gene expression. Additionally, preliminary studies in tumor-bearing athymic nude mice demonstrated gene uptake and expression via intratumoral injection of 457 and 446LG polymer/DNA complexes. Ongoing studies include further optimization of PBAEs for in vitro gene expression and systemic in vivo delivery. In parallel, we are performing genetic characterization of patient-derived primary SCLC xenografts to verify relevant gene targets. Taken together, our data supports further development of a non-viral PBAE-based gene delivery approach in SCLC. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 5411. doi:10.1158/1538-7445.AM2011-5411
PERFORMANCE CHARACTERISTICS OF SCINTIGRAPHIC COLON TRANSIT MEASUREMENT IN HEALTH AND IRRITABLE BOWEL SYNDROME AND RELATIONSHIP TO BOWEL FUNCTIONS

Colonic transit time (CTT) refers to the time taken for chyme to pass through the colon. Measurement of CTT is frequently performed in clinical practice to identify colonic motor function abnormalities, for example, in patients with irritable bowel syndrome (IBS) [1] or constipation [2–4]. This method is also used to investigate pathophysiological mechanisms that lead to symptoms or syndromes [5, 6] and to evaluate the effect of treatment [7, 8]. The most widely applied techniques evaluate movement of radiopaque markers through the gut [3, 9] or appearing in stool [10]. A less commonly used method involves scintigraphy, which is valuable for the assessment of gastrointestinal function in humans [11]. Both provide noninvasive and quantitative assessments of colonic transit. In the most commonly applied radiopaque marker transit technique, subjects ingest radiopaque markers on three [9] or six [12] consecutive days, and a single abdominal x-ray is obtained on the subsequent day and, if necessary, on one or more days later [13]. With the most widely used and published scintigraphic method, radiolabeled charcoal particles [14] are delivered to the colon in a delayed-release, methacrylate-coated capsule [15], and gamma camera images are acquired at specified times during a 48-hour period. Regardless of the method, there is considerable intra-subject variation in colonic transit [16–19], possibly because some studies administered the radiolabel in the meal rather than in a delayed-release capsule which delivers radiolabeled solid particles to the ileocolonic junction. Moreover, intra-subject variation has been studied mainly in healthy volunteers [20–23], with only 2 studies having evaluated the reproducibility of radiopaque marker CTT in disease states. Thus, Nam et al [4]reported an acceptable reproducibility in 22 patients with idiopathic constipation, but poor reproducibility in patients with colonic inertia or paradoxical puborectalis contraction. In another study by Bouchoucha et al [24] which included 30 healthy volunteers and 43 patients with IBS, 16 subjects underwent repeat colonic transit testing with radiopaque markers and, therefore, there are data on the reproducibility of radiopaque marker transit in some IBS patients. No significant differences were found between the two test results, but it is not clear whether these subjects were healthy controls or IBS patients. Thus, the reproducibility of CTT measurements in disease states remains unclear. The aim of this study was to assess the inter- and intra-subject variations of scintigraphic colonic transit parameters in patients with IBS and healthy participants. A secondary aim was to quantify the relationship between colonic transit measurement and bowel functions. For the purpose of the current study in which the focus was on variation in IBS patients, we excluded the previously reported performance characteristics in 37 healthy participants [20].
Comparative plasma kinetics of orally administered sulfamethazine in clinically parasitized and parasitism‐treated lambs

Sulfamethazine was administered at a dosage of 99 mg/kg body weight to lambs with a naturally acquired parasitism and again at 37 days following treatment with an anthelmintic. Blood samples were analyzed for sulfonamides over a 72 h period following sulfamethazine administration in both phases of the study. Pharmacokinetic parameter estimates of the sulfonamide blood data demonstrated significantly lower peak levels, longer times to peak and higher blood levels of the drug as time after dosing increased, in the parasitized as compared with the parasitism-treated lambs.
Comparison of apoA-I helical structure and stability in discoidal and spherical HDL particles by HX and mass spectrometry

Elucidation of apoA-I secondary structure in spherical plasma HDL particles is essential for understanding HDL structure and function at the molecular level. To provide this information, we have applied hydrogen exchange (HX) and mass spectrometry methods to compare apoA-I secondary structure in discoidal (two apoA-I molecules/particle) and spherical (five apoA-I molecules/particle) HDL particles. The HX kinetics indicate that the locations of helical segments within the apoA-I molecules are the same in both discoidal and spherical HDL particles (approximately 10 nm hydrodynamic diameter). Helix stabilities in both types of particles are 3–5 kcal/mol, consistent with the apoA-I molecules being in a highly dynamic state with helical segments unfolding and refolding in seconds. For the spherical HDL, apoA-I fragments corresponding to residues 115–158 exhibit bimodal HX kinetics consistent with this segment adopting an inter-converting (on the timescale of tens of minutes) helix-loop configuration. The segment adopting this configuration in the 10 nm disc is shorter because the surface area available to each apoA-I molecule is apparently larger. Loop formation in the central region of the apoA-I molecule contributes to the ability of the protein to adapt to changes in available space on the HDL particle surface. Overall, apoA-I secondary structure is largely unaffected by a change in HDL particle shape from disc to sphere.
Coliphages as indicators of enteric viruses in shellfish and shellfish raising estuarine waters

Abstract The practicality of a coliphage indicator system for human enterovirus in polluted waters was studied. Parallel examinations of sewage effluents, shellfish and shellfish growing waters for coliphage and enteric virus indicated a wide dissemination of coliphage throughout the estuary, generally occurring in the absence of detectable enteric virus activity. A majority of the enteric virus isolations were observed in samples yielding no coliphage activity. Under controlled conditions, oysters were observed to accumulate more coliphage than enteric virus. Replication of coliphage in the estuary during the summer months was shown to occur when proper host cell was present. Two major coliphage types were observed in field samples based on their reactivity with different Escherichia coli strains. A shift in dominant coliphage type was seen to occur during the study. Survival times of coliphage and enteric virus in estuary waters along with retention values in oysters were shown to be similar with a slight advantage shown by coliphage. Inability to correlate accurately coliphage and enteric virus occurrence in field samples along with the potential for the presence of more than one dominant coliphage type indicated the serious shortcomings of the coliphage indicator system as a method of enteric virus detection, leaving its overall use in the polluted environment subject to grave doubt.