cssi/SciSciGPT-SciSciNet huggingface dataset:
Ribosome-chloramphenicol interactions: a nuclear magnetic resonance study.

Abstract Proton magnetic resonance line broadening of chloramphenicol resonances has been employed to study the binding of this inhibitor of protein synthesis to the Escherichia coli 70 S ribosome. Temperature dependence measurements of the resonance line widths show that chloramphenicol is in fast exchange with the ribosome. Differential broadening of the various drug resonances suggests that it binds in its receptor site in essentially the same conformation that exists free in solution. Thus, even though the drug possesses a fair degree of structural flexibility, this is not necessary for its interaction with the ribosome. The recognition is most likely of the classic lock and key type, with the ribosomal site being essentially an open gate for the fitting of the drug. From the proton line-width measurements and 19F spectra of a derivative, it has been possible to propose a model for the geometry of chloramphenicol when it resides on the ribosome which is consistent with established structure-activity relationships for the drug.
Experimental tests of two-phase fluid model of drying consolidation

Drying of aggregated slurries proceeds through a stage of consolidation prior to bed desaturation. During this period, volume fraction profiles develop within the bed. The magnitude of volume fraction variation is controlled by the rate of mass transfer and the strength of the bed. A two-phase fluid model for stress balances in conjunction with the compressive yield stress constitutive equation is explored to describe the temporal evolution of bed volume fraction profiles. For this purpose, the compressive rheology of the saturated bed is characterized through independent experiments that fix all adjustable parameters. Excellent agreement is found between model predictions and experimental results.
Performance evaluation of an incorporated DCT block-based watermarking algorithm with human visual system model

In this paper we propose a new approach to predict a fixed fidelity level of a watermarked image while increasing the detection rate. The new approach incorporates a DCT block-based algorithm with human visual system (HVS). The performance of the new approach has been defined in terms of its effectiveness (detection rate) and fidelity. We show experimentally how our novel approach can be used to control distribution of a watermark to get a higher detection rate as well as better fidelity.
Bowtie plasmonic aperture for single quantum emitter absorption measurement

Bowtie apertures with gap sizes of less than 30nm are fabricated successfully by lift-off process. Simulations show that they have mode area as small as 0.011(l/n)2, which is two orders smaller than a conventional tightly focused laser spot.
Obtaining synchronous cultures of algae.

A COMMUNICATION from Lafeber and Steenbergen1 described a “simple device for obtaining synchronous cultures of algae”. They stated that Scenedesmus obliquus, Ankistrodesmus falcatus, and Chlorella vulgaris all underwent synchronous cell division induced by the photo-period used.
Absorption spectra and oscillator strength of KBr:Pb

Abstract Absorption measurements on hydroxide-free KBr crystals containing various amounts of Pb 2+ were made. The spectra were corrected for scattering and reflection losses and the B -, C - and D -bands were deconvoluted as three Gaussian bands. Band maxima were found: A -band at 4.15 ± 0.05 eV, 5-band at 5.1 ± 0.1 eV, C -band at 5.52 ± 0.07 eV, D 1 -band at 5.79 ± 0.05 eV. The oscillator strengths for the A -, B - and C -bands were 0.12 ± 0.01, 0.04 ± 0.01 and 0.77 ± 0.02, respectively. The ƒ-sum for the three bands is 0.93. The nearness of the ƒ-sum to unity indicates that very little interaction between the impurity s 2 electrons and the host and supports the usual assumption that these bands originate from the same ground state.
The strength of non-covalent biological bonds and adhesions by multiple independent bonds.

Non-covalent bonds of the same type as antibody-antigen bonds—“affinity bonds”—are one of the most important types of structural bonds on the cellular level, mediating interactions such as cell-cell and cell-extracellular matrix adhesion, providing the integrity of such structures as microtubules and actin filaments, and producing force in muscle, flagella and cilia. The affinity bonds in these and many other interactions are subject to forces during the life of the cell. However, the tensile strength of these bonds, and how this determines the strength of the interactions on the cellular level, is largely unknown. We have attempted to calculate the tensile strength of an affinity bond by modelling binding as a multistep process in which the binding molecules first diffuse together, overcome an activation energy, and then bind. By calculating the energies associated with each step, the energy actually contained in the bond can be determined, yielding the bond strength. The “average” affinity bond is thus found to have a tensile strength of about 40 μdyn. However, the temporal nature of affinity bonds (thermal fluctuations will eventually break them) causes the strength of the interactions to be actually somewhat weaker, with the outcome of putting tension on a group of bonds depending strongly on the conditions.
A compact wide-band EBG structure utilizing embedded resonant circuits

This letter presents a wide-band electromagnetic bandgap (EBG) structure designed utilizing embedded resonant circuits (ERCs). The EBG structure is a periodic material whose unit cell is composed of a number of small resonant LC circuits. For EBG composed of single resonant LC circuits above the resonant frequency, the structure behaves as a negative permeability material that provides the bandgap behavior. To design a compact wide-band EBG, a structure constructed of three layers of ERC, each having different resonant frequencies separated by layers of impedance inverters, is proposed. The impedance inverter layer is designed using I-shaped metallic inclusions printed in the host medium to achieve a high dielectric material so as to physically reduce the thickness of the quarter wavelength inverters. The design and performance characteristic of a complete EBG structure with isotropic bandgap behavior almost independent of incident angle and polarization state is also demonstrated.
Cell biology: Balancing act

The enzyme parkin is known to promote disposal of organelles called mitochondria that have suffered damage. The identification of an enzyme that opposes parkin demonstrates how a delicate balance is maintained in the cell. See Article p.370
Photodynamic therapy cures green fluorescent protein expressing RIF1 tumors in mice

Cancer is a leading cause of death among modern people, largely due to metastatic disease. The ideal cancer treatment should destroy both the primary tumor and distant metastases with minimal toxicity to normal tissue. This is best accomplished by educating the body's immune system to recognize the tumor as foreign so that after the primary tumor is destroyed, distant metastases will also be eradicated. Photodynamic therapy (PDT) involves the IV administration of photosensitizers followed by illumination of the tumor with red light producing reactive oxygen species that eventually cause vascular shutdown and tumor cell apoptosis. Anti-tumor immunity is stimulated after PDT due to the acute inflammatory response, generation of tumor-specific antigens, and induction of heat-shock proteins. Combination regimens are likely to emerge in the future to even further enhance immunity. Green fluorescent protein is used as an optical reporter to non-invasively image the progression of mouse tumors, and in addition, may act as a foreign (jellyfish) antigen. We asked whether the response of tumor bearing mice to PDT differed when a non-immunogenic tumor cell line was transfected with GFP? We injected RIF-1 or RIF1-EGFP cells in the leg of C3H/HeN mice and both the cells and tumors grew equally well. We used two PDT protocols (benzoporphyrin derivative (BPD) with 15-minute interval or Photofrin with 24-hour interval). The results showed significant differences between the responses of RIF1 or RIF1-EGFP tumors after BPD or Photofrin PDT and complete cures and mouse survival when RIF-1 EGFP tumors were treated with BPD. This increased tumor response may be due to antibody-mediated cytotoxicity and the presence of an artificial tumor antigen (GFP) that can produce a CD8 T-cell response against the whole tumor. The presence of antibodies against EGFP in mouse serum correlates with the hypothesis.
Gender, race, and the determinants of commuting: New york in 1990

This research examines changing race and gender differences in commuting time and their relationships to social and economic restructuring in the New York metropolitan region. During the 1980s, the region's economic base and social fabric changed dramatically with a continued loss of manufacturing employment, rise of service employment, growth of households headed by women, and accelerated suburbanization. Using 1980 and 1990 PUMS data, we analyze gender differences in commuting times in central and suburban areas for African American, Latino, and White workers. We also analyze the determinants of commuting time for each gender/race group in 1980 and 1990. The results indicate that, despite significant restructuring, average commuting times have changed only slightly. Moreover, the major determinants of commuting times have remained stable: wages and means of transportation strongly affect work-trip length for all gender/race groups in all parts of the urban region. Household characteristics have the most...
A robust receiver for power line communications in integrated circuits

This paper presents a power line communications (PLC) receiver in ICs with emphasis on robustness. The PLC receiver intends to control internal logic values of ICs through power pins. It employs a differential Schmitt trigger to increase noise immunity and tolerate supply voltage fluctuations. The receiver is designed and laid out in 0.18 µm CMOS technology. Post-layout simulation results show that the receiver can operate up to 22.2 percent of the supply voltage drop under the signal-to-noise ratio (SNR) of 16.3 dB. The receiver dissipates 2.4 mW under 1.8 V supply, which is lower than earlier PLC receivers.
Comparison of a One-Dimensional and a Three-Dimensional SREMP Model for an Overhead Line

This paper compares two models for calculating the SREMP response of a long overhead line, a transmission line model and a three-dimensional Maxwell solver code model. Currents on the line, in the air and in the ground are examined. Recommendations for and improved transmission line model result from the comparisons. Calculations are included which should result in improved transmission line parameters.
Personality and Values as Predictors of Medical Specialty Choice.

Abstract Research rarely considers the combined influence of personality traits and values in predicting behavioral outcomes. We aimed to advance a germinal line of inquiry that addresses this gap by separately and simultaneously examining personality traits and physician work values to predict medical specialty choice. First-year medical students (125 women and 119 men) responded to measures of personality and physician work values. After graduation, participants' residency choices were identified. Results indicated that personality traits predict person- or technique-oriented medical specialty choice. Physician work values, whether used alone or in tandem with personality traits, however, did not significantly predict specialty choice. Implications for practice and research are discussed.
Method to Evaluate Ease of Pericarp Removal on Lime-Cooked Corn Kernels

A simple and effective method to evaluate the ease of pericarp removal on lime (CaO)-cooked corn (Zea mays L.) has been developed. Corn kernels placed in perforated nylon bags are lime-cooked for 20 min at 98 to 100 °C and then stained in a solution containing methylene blue and eosine Y. We evaluated 11 corn hybrids grown at seven locations in 1989. The relative ease of pericarp removal was affected by hybrid and by growth environment, with hybrid differences being most important. The method requires a small samples, is rapid, and is ideally suited for ease of pericarp removal in screening large numbers of samples in breeding programs (...)
Glial polypeptides transferred into the squid giant axon.

Abstract The proteins synthesized by the glial sheath of an isolated segment of squid giant axon and by the cell bodies of the giant axon in the isolated stellate ganglion were labeled by incubation in the presence of [3H]leucine. The axoplasm, which contained labeled proteins transferred from the glial sheath, was separated from the sheath by mechanical extrusion. The labeled proteins in the axoplasm, the empty sheath and the stellate ganglion were analyzed and compared by one- and two-dimensional polyacrylamide gel electrophoresis. Over 80 glial polypeptides were found to be selectively transferred into the axoplasm and many of these were distinct from stellate ganglion polypeptides which presumably could be supplied to the axon via axonal transport. Three of the more highly labeled transferred glial polypeptides (TGPs) were actin, a fodrin-like polypeptide and a polypeptide we have named traversin. Our observations, considered in the context of other reports, suggest that the squid axon receives a large number of polypeptides from its sorrounding glia either by phagocytozing glial cell processes that project into it or via cytoplasmic channels between adaxonal glia and the axon. These TGPs may help the axon survive unfavorable conditions.
Anterior segment sparing to reduce charged particle radiotherapy complications in uveal melanoma

PURPOSE: The purpose of this investigation is to delineate the risk factors in the development of neovascular glaucoma (NVG) after helium-ion irradiation of uveal melanoma patients and to propose treatment technique that may reduce this risk. METHODS AND MATERIALS: 347 uveal melanoma patients were treated with helium-ions using a single-port treatment technique. Using univariate and multivariate statistics, the NVG complication rate was analyzed according to the percent of anterior chamber in the radiation field, tumor size, tumor location, sex, age, dose, and other risk factors. Several University of California San Francisco-Lawrence Berkeley National Laboratory (LBNL) patients in each size category (medium, large, and extralarge) were retrospectively replanned using two ports instead of a single port. By using appropriate polar and azimuthal gaze angles or by treating patients with two ports, the maximum dose to the anterior segment of the eye can often be reduced. Although a larger volume of anterior chamber may receive a lower dose by using two ports than a single port treatment. We hypothesize that this could reduce the level of complications that result from the irradiation of the anterior chamber of the eye. Dose-volume histograms were calculated for the lens, and compared for the single and two-port techniques. RESULTS: NVG developed in 121 (35%) patients. The risk of NVG peaked between 1 and 2.5 years posttreatment. By univariate and multivariate analysis, the percent of lens in the field was strongly correlated with the development of NVG. Other contributing factors were tumor height, history of diabetes, and vitreous hemorrhage. Dose-volume histogram analysis of single-port vs. two-port techniques demonstrate that for some patients in the medium and large category tumor groups, a significant decrease in dose to the structures in the anterior segment of the eye could have been achieved with the use of two ports. CONCLUSION: The development of NVG after helium-ion irradiation is correlated to the amount of lens, anterior chamber in the treatment field, tumor height, proximity to the fovea, history of diabetes, and the development of vitreous hemorrhage. Although the influence of the higher LET deposition of helium-ions is unclear, this study suggests that by reducing the dose to the anterior segment of the eye may reduce the NVG complications. Based on this retrospective analysis of LBNL patients, we have implemented techniques to reduce the amount of the anterior segment receiving a high dose in our new series of patients treated with protons using the cyclotron at the UC Davis Crocker Nuclear Laboratory (CNL).
In vitro detection of beta amyloid exploiting surface enhanced Raman scattering (SERS) using a nanofluidic biosensor

Alzheimer's disease (AD), a neurodegenerative disease and the most common cause of dementia, affects 4.5 million people according to the 2000 US census and is expected to triple to 13.2 million by the year 2050. Since no definitive pre-mortem tests exist to distinguish AD from mild cognitive impairment due to the natural aging process, we focus on detecting the beta amyloid (Aβ) protein, the primary component of the senile plaques characteristic of AD. We specifically detect cytotoxic species of Aβ by exploiting surface enhanced Raman scattering (SERS). Using a nanofluidic device with a bottleneck shape (a microchannel leading into a nanochannel); we trapped gold colloid particles (60 nm) at the entrance to the nanochannel, with Aβ restricted within the interstices between the aggregated nanoparticles. The continuous flow generated from pumping the solution into the device produced size-dependent trapping of the gold colloid particles, resulting in a high density of aggregated nanoparticles at this precise region, creating localized "hot spots" in the interstitial region between nanoparticles, and shifting the plasmon resonance to the near infrared region, in resonance with incident laser wavelength. With this robust sensing platform, we were able to obtain concentration-dependent SERS spectra of Aβ and of different proteins present in the cerebrospinal fluid of healthy people and people with Alzheimer's disease.
Idiopathic inflammatory myopathy: Autoantibody update

Several defined, specific autoantibodies have been associated with polymyositis and dermatomyositis. These include autoantibodies to at least six of the aminoacyl-transferribonucleic-acid synthetases; to the signal recognition particle; to the protein complexes labeled Mi-2 and PM-Scl; and several autoantibodies, such as anti-U1nRNP and anti-Ro/ SSA, that have recognized associations with other conditions. These autoantibodies are a continuing area of interest. Recent studies have involved the clinical implications of these autoantibodies, and their potential significance for etiology and pathogenesis of the disease. This report will review recent studies of myositis autoantibodies and their clinical associations, both extramuscular features, such as interstitial lung disease and aspects of the myositis itself. New myositis autoantibodies continue to emerge, which may have clinical utility. Several have been associated with dermatomyositis, including juvenile dermatomyositis, which has a low frequency of traditional myositis autoantibodies. There is also new information regarding the antigenic targets of anti-Mi-2 and anti-PM-Scl, two of the earliest recognized myositis autoantibodies. New evidence over the past few years has challenged old concepts of the relationship of autoantibodies to the pathogenesis of myositis, and has suggested potential new mechanisms for the origin of the associated autoantibodies. Despite this progress, the reason for production of the autoantibodies and their role in tissue injury remain unknown.
Overexpression of phosphorylated nuclear factor-kappa B in tonsillar squamous cell carcinoma and high-grade dysplasia is associated with poor prognosis

Intracellular signals along the epidermal growth factor receptor (EGFR)-Akt-nuclear factor-kappa B (NF-kappaB) pathway have been associated with carcinogenesis in various malignant neoplasms. This investigation was to evaluate the expression of EGFR, phosphorylated(p)-Akt and p-NF-kappaB and correlate them with clinical outcomes in patients with squamous cell carcinoma of the tonsil. A total of 45 patients with squamous cell carcinoma of the tonsil were studied by immunohistochemistry to evaluate the expression levels of EGFR, p-Akt and p-NF-kappaB. Results for squamous cell carcinoma of the tonsil were compared with those for associated high-grade dysplasia and adjacent normal appearing epithelium, when present. In addition, tonsillar epithelium from non-neoplastic specimens of age-matched patients also was stained for the same markers. High-grade dysplasia and squamous cell carcinoma of the tonsil demonstrated a similar pattern of expression, which differed from the pattern seen in the adjacent normal epithelium and tonsillar epithelium from normal controls (an overexpression for each of these three protein analytes in high-grade dysplasia and squamous cell carcinoma of the tonsil as demonstrated by immunohistochemistry). When markers from squamous cell carcinoma of the tonsil were correlated with survival status, only increasing levels of p-NF-kappaB immunoreactivity (a relative overexpression) were statistically significant predictors of poor survival. No markers in squamous cell carcinoma of the tonsil were significantly related to rate of recurrence. When analyzing marker scores from tissue with high-grade dysplasia, relative overexpressions of both p-Akt and p-NF-kappaB were significantly related to poor survival. Additionally, increasing levels of p-NF-kappaB immunopositivity from tissue with high-grade dysplasia were also significantly related to rate of recurrence. In summary, p-NF-kappaB, overexpressed in high-grade dysplasia and squamous cell carcinoma of the tonsil, is associated with worse prognosis in terms of high recurrence and poor survival, respectively. This significant finding in patients with squamous cell carcinoma of the tonsil, in combination with previous animal and in vitro studies, suggests that p-NF-kappaB represents a potential therapeutic target in head and neck squamous cell carcinoma.
Two-Dimensional Linear Prediction Covariance Method and Its Recursive Solution

The two-dimensional (2-D) linear prediction "covariance" method is considered for the general case of a predictor with an asymmetric half-plane support lattice. The extension of a previous one-dimensional algorithm, based on conjugate directions, for solving recursively the symmetric set of normal equations for the 2-D covariance method is discussed. The effects of modeling caused by the choice of support lattices and of the ordering for the predictor coefficients are also studied. Examples are provided illustrating the various issues involved in modeling and the application of the "covariance" method in image coding.
Bayesian serial cost sharing

Abstract Shared productive facilities often entail incomplete information regarding attributes such as production costs, production quality, user lists, user preferences, etc. We formulate the notion of Bayesian cost share games to model such environments and find that many of the desirable features the serial cost-sharing rule enjoys in nonstochastic settings also extend to Bayesian frameworks. We also introduce the concept of normal goods to cost-sharing games and demonstrate that normality further strengthens the serial rule's appeal.
Polymorphs with varying platinum(II)-thallium(I) interactions.

TlI[(C4H9N4)PtII(CN)2] forms a red, crystalline polymorph in which the ions are arranged to form an extended ···Pt···Tl···Pt···Tl··· chain (Pt···Tl distance, 3.0978(2) A; Pt−Tl−Pt and Tl−Pt−Tl angles, (171.37(2)°) and a yellow polymorph in which dimers are connected by pairs of Pt···Tl interactions with a Pt···Tl distance of 3.0256(5) A.
A randomized, double-blind, placebo-controlled, trial of lamotrigine therapy in bipolar disorder, depressed or mixed phase and cocaine dependence

Bipolar disorder is associated with very high rates of substance dependence. Cocaine use is particularly common. However, limited data are available on the treatment of this population. A 10-week, randomized, double-blind, placebo-controlled trial of lamotrigine was conducted in 120 outpatients with bipolar disorder, depressed or mixed mood state, and cocaine dependence. Other substance use was not exclusionary. Cocaine use was quantified weekly by urine drug screens and participant report using the timeline follow-back method. Mood was assessed with the Hamilton rating scale for depression, quick inventory of depressive symptomatology self-report, and young mania rating scale. Cocaine craving was assessed with the cocaine-craving questionnaire. Data were analyzed using a random regression analysis that used all available data from participants with at least one postbaseline assessment (n=112). Lamotrigine and placebo groups were similar demographically (age 45.1±7.3 vs 43.5±10.0 years, 41.8% vs 38.6% women). Urine drug screens (primary outcome measure) and mood symptoms were not significantly different between groups. However, dollars spent on cocaine showed a significant initial (baseline to week 1, p=0.01) and by-week (weeks 1–10, p=0.05) decrease in dollars spent on cocaine, favoring lamotrigine. Few positive trials of medications for cocaine use, other than stimulant replacement, have been reported, and none have been reported for bipolar disorder. Reduction in amount of cocaine use by self-report with lamotrigine suggests that a standard treatment for bipolar disorder may reduce cocaine use. A study limitation was weekly assessment of urine drug screens that decreased the ability to detect between-group differences.
Interprofessional education through service-learning: lessons from a student-led free clinic

The academic community must replicate and strengthen existing models for interprofessional education (IPE) to meet widespread calls for team-based patient-centered care. One effective but under-explored possibility for IPE is through student-led clinics, which now exist in the majority of medical schools. This short report presents the Indiana University Student Outreach Clinic (IU-SOC), which involves seven different professional programs across three institutions, as a model for how IPE can be delivered formally through service learning. Lessons learned, such as nurturing an intentional interprofessional program, structured orientation and reflection, and resource and knowledge sharing between the clinic and academic institutions, can be applied to all student-led clinics, but also can inform other IPE initiatives in health professional curricula.
New directions in rock mechanics — report on a forum sponsored by the American Rock Mechanics Association

Abstract The American Rock Mechanics Association (ARMA) and the ARMA Foundation sponsored a forum on New Directions for US Rock Mechanics which was held at the Asilomar Conference Center in Pacific Grove, California, USA, during 18–20 October 1998. The goal of the Forum was to focus on: (1) a strategic vision for the future of rock mechanics in the United States; (2) the identification and delineation of critical issues facing the rock mechanics community; (3) the role of research in addressing these issues; and (4) critical areas of research in each of the topic areas addressed at the forum including examples of specific research initiatives. To a large degree, rock mechanics has been used successfully to model and predict the behavior of fractured rock masses for building large structures. However, improvements on present success, and future advances in modeling and construction, are predicated on better characterization of fractured rock masses. This will require increasing emphasis on non-linear and discontinuity-based models to reflect the mechanisms at work in fractured rock masses. For example, relevant characterization schemes, as well as field, laboratory, and logging techniques have yet to be developed for weak rock conditions and for all but the simplest fluid flow conditions. This report summarizes two days of discussion held during the Forum. It was the sense of the Forum participants that fundamental improvements in in situ rock mass characterization is of the utmost importance. Every session emphasized that obtaining valid information from large volumes of rock is the prerequisite for the effective and improved practice of rock mechanics. Research and application of remote imaging and non-destructive evaluation of the subsurface should provide a source of economically realizable data from large volumes of rock. This area should be a primary goal of future research. Associated with the question of site characterization is the degree of uncertainty associated with the data, and with the chosen interpretive model. Forum participants also recommended conducting research to find implementations of stochastic techniques, which would allow uncertainty to be dealt with in a rational manner.
Estimation of ventricular fiber orientations in infarcted hearts for patient-specific simulations

Patient-specific modeling of the heart is limited by lack of technology to acquire myocardial fiber orientations in the clinic. To overcome this limitation, we recently developed an image-based methodology to estimate the fiber orientations. In this study, we test the efficacy of that methodology in infarcted hearts. To this end, we implemented a processing pipeline to compare estimated fiber orientations of infarcted hearts with measured ones, and quantify the effect of the estimation error on outcomes of electrophysiological simulations. The pipeline was applied to images that we acquired from three infarcted canine hearts. The new insights obtained from the project will pave the way for the development of patient-specific models of infarcted hearts that can aid physicians in personalized diagnosis and decisions regarding electrophysiological interventions.
Program practices and demographic factors associated with federal funding for the Safe Routes to School program in the United States

In 2005, the United States Congress authorized $612 million for use in implementing the US Safe Routes to School program to address physical inactivity, air quality, safety and traffic near schools. Each US state developed administrative practices to implement the program. Based on state-specific annual obligations, on average, states have obligated 44% of available funds. State project obligations were directly associated with programmatic factors, including broader adherence to federal agency administrative guidance objectives and the number of years for which the states obligated new projects and indirectly associated with student enrollment and state child poverty. Research and policy recommendations are discussed.
Turbulent duct flow with streamwise nonuniform heating at the duct wall

Abstract A combined experimental and analytical/numerical investigation has been carried out for turbulent flow in a flat, rectangular duct with streamwise nonuniform heating at one of the principal walls. The investigated heating pattern consisted of adiabatic zones periodically inserted between isothermal heated zones. The relative streamwise lengths of the heated zones and the adiabatic zones were varied parametrically, as was the Reynolds number. Heat transfer coefficients were determined at each of the heated zones, both in the thermal entrance region and in the fully developed region. It was found that the presence of the adiabatic zones can give rise to substantial enhancement of the heat transfer coefficients at the heated zones. For a duct of fixed overall length, the use of the adiabatic zones represents a loss in transfer surface area, which brings about a net decrease in the overall rate of heat transfer. The agreement between the numerical and experimental results was typically in the two percent range, an outcome which recommends the numerical model as a tool for studying other nonuniform heating patterns.
Synthesis of Cobalamin−Biotin Conjugates That Vary in the Position of Cobalamin Coupling. Evaluation of Cobalamin Derivative Binding to Transcobalamin II

Six cobalamin-biotin conjugates have been prepared. The cobalamin-biotin conjugates were prepared to evaluate the effect that the location of attachment had on the binding with transcobalamin II (TCII), the cobalamin binding protein in plasma, and to evaluate their potential use for in vitro and in vivo applications. This study focused only on the effect of binding with TCII. To decrease the possibility of steric problems in binding of the cobalamin conjugates with TCII, and biotin's binding with streptavidin or avidin, moieties of 11-18 atoms in length were used as linkers. Four biotin conjugates were prepared which were attached to the corrin ring of the cobalamin molecule (on b-, c-, d-, and e-side chains). One conjugate was attached to the 5'-OH of the ribose moiety, and another conjugate was attached at the cobalt metal (in place of the cyanide moiety of cyanocobalamin). Competitive binding studies were conducted where various amounts of the cobalamin-biotin conjugates and their precursor cobalamin derivatives competed with [57Co]cyanocobalamin for binding of recombinant human TCII (rhTCII). Evaluation of cobalamin derivatives which were conjugated at the 5'-OH of ribose or the cobalt metal center indicated that conjugation at either of these positions had little effect on binding with rhTCII. However, conjugates where the attachment was made on the corrin ring substituents had a large variation in binding with rhTCII. Conjugates on the e-propionamide side chain had little effect (relative affinity was equal to or decreased less than a factor of 3) on binding with rhTCII, conjugates of the b-isomer had decreased binding (relative affinity decreased less than a factor of 10), conjugates of the d-propionamide had further decreased binding (relative affinity decreased between 44 and 69 times), and conjugates on the c-acetamide group had poor binding to rhTCII (relative affinity decreased between 295 and 1160 times). The significance of the side chains on the corrin ring in providing specificity and high-affinity binding with rhTCII is discussed.
Flavobacterium johnsoniae Gliding Motility Genes Identified by mariner Mutagenesis

Cells of Flavobacterium johnsoniae glide rapidly over surfaces. The mechanism of F. johnsoniae gliding motility is not known. Eight gld genes required for gliding motility have been described. Disruption of any of these genes results in complete loss of gliding motility, deficiency in chitin utilization, and resistance to bacteriophages that infect wild-type cells. Two modified mariner transposons, HimarEm1 and HimarEm2, were constructed to allow the identification of additional motility genes. HimarEm1 and HimarEm2 each transposed in F. johnsoniae, and nonmotile mutants were identified and analyzed. Four novel motility genes, gldK, gldL, gldM, and gldN, were identified. GldK is similar in sequence to the lipoprotein GldJ, which is required for gliding. GldL, GldM, and GldN are not similar in sequence to proteins of known function. Cells with mutations in gldK, gldL, gldM, and gldN were defective in motility and chitin utilization and were resistant to bacteriophages that infect wild-type cells. Introduction of gldA, gldB, gldD, gldFG, gldH, gldI, and gldJ and the region spanning gldK, gldL, gldM, and gldN individually into 50 spontaneous and chemically induced nonmotile mutants restored motility to each of them, suggesting that few additional F. johnsoniae gld genes remain to be identified.
Respiration and glycolysis of human cells grown in tissue culture.

Abstract The respiration and glycolysis of nine human cell lines grown in continuous tissue culture have been examined; 5 derived from normal and 4 from malignant tissues. In addition, 2 sublines of one strain were studied which were persistently infected with mumps and Newcastle disease viruses. The general metabolic patterns of respiration, anaerobic glycolysis, and aerobic glycolysis were similar for all the uninfected cell lines. The observed metabolic values appear similar to those reported for slices of malignant tissues. It cannot be concluded on this basis whether all the cells studied are of a “malignant variety” or whether all cells established in continuous tissue culture develop a metabolic behavior similar to that of cancer tissue. Metabolic measurements on the persistently infected lines revealed no significant changes in respiration. However, the cultures carrying Newcastle disease virus exhibited a marked increase in aerobic glycolysis. Although the cell lines fall into two groups on the basis of their viral spectra and morphology, no outstanding differences were noted in the metabolic properties measured.
Antagonist-induced μ-opioid receptor up-regulation decreases G-protein receptor kinase-2 and dynamin-2 abundance in mouse spinal cord

Chronic treatment with opioid receptor antagonists has been shown to increase the density of μ-, δ- and κ-opioid receptors in cell culture and in the intact animal. Although opioid receptor antagonist-induced up-regulation is a robust phenomenon, the mechanisms responsible for the increase in receptor density remain unclear. In the present study, changes in a kinase and a GTPase that have been implicated in G-protein-coupled receptor regulation were examined following opioid receptor antagonist treatment. Mice were implanted s.c. with a naltrexone pellet or placebo pellet. On the eighth day following implantation, spinal cord was removed and G-protein receptor kinase-2 (GRK-2) and dynamin-2 abundance were determined using a quantitative immunoblot approach. Changes in μ-opioid receptor density were also determined. Naltrexone treatment produced a significant (145%) increase in μ-opioid receptor density. Naltrexone treatment was associated with a significant 36% decrease in GRK-2 and 30% decrease in dynamin-2 abundance in spinal cord. These data raise the possibility that opioid receptor antagonist-induced μ-opioid receptor up-regulation in the intact animal may be due to a reduction in constitutive internalization of opioid receptors.
Mathematical Modeling of Nanocomposite Properties Considering Nanoclay/Epoxy Debonding

The purpose of this study is to develop analytical equations using micromechanical methods that can effectively and accurately estimate the mechanical properties of polymer composite materials containing clay nanoparticle fillers. Various modeling techniques using the micromechanical approach are researched, including conventional micromechanical models. An analytical model was developed with consideration of the effects of imperfect bonding between the nanoparticle fillers and the matrix in the composite materials. The mechanical properties of the considered nanocomposites were estimated, and the estimated values were validated using the experimentally determined mechanical properties. For the experimental program, clay/epoxy nanocomposite specimen were fabricated and tested. The developed model was also compared to the conventional and previously developed micromechanical models.
Focal Adhesion Kinase Is Involved in Angiotensin II–Mediated Protein Synthesis in Cultured Vascular Smooth Muscle Cells

The rate of vascular smooth muscle cell protein synthesis and cellular hypertrophy in response to angiotensin II (Ang II) is dependent on activation of protein tyrosine kinases (PTKs) and both the extracellular signal-regulated kinase (ERK) 1/2 and p70(S6K) pathways. One potential PTK that may regulate these signaling cascades is focal adhesion kinase (FAK), a nonreceptor PTK associated with focal adhesions. We used an actin depolymerizing agent, cytochalasin D (Cyt-D), and a replication-defective adenovirus encoding FAK-related nonkinase (FRNK), an inhibitor of FAK-dependent signaling, as tools to assess whether FAK was upstream of the ERK1/2 and/or the p70(S6K) pathways. Cyt-D reduced basal FAK phosphorylation and blocked Ang II-dependent FAK phosphorylation in a dose-dependent manner. Confocal microscopy indicated that Cyt-D induced actin filament disruption and FAK delocalization from focal adhesions. Cyt-D also reduced Ang II-induced ERK1/2 activation, but p70(S6K) activation was relatively unaffected. Cyt-D reduced basal protein synthetic rate and substantially reduced the Ang II-induced increase in protein synthesis. Similarly, FRNK overexpression blocked Ang II-induced FAK phosphorylation and ERK1/2 activation, but not p70(S6K) phosphorylation, and markedly inhibited protein synthesis. This is the first report to demonstrate that FAK is a critical component of the signal transduction pathways that mediate Ang II-induced ERK1/2 activation, c-fos induction, and enhanced protein synthesis in vascular smooth muscle cells.
Cloning and Functional Characterization of a Mouse Intestinal Acyl-CoA:Monoacylglycerol Acyltransferase, MGAT2

Acyl-CoA:monoacylglycerol transferase (MGAT) plays a predominant role in dietary fat absorption in the small intestine, where it catalyzes the first step of triacylglycerol resynthesis in enterocytes for chylomicron formation and secretion. Although the mouse small intestine exhibits the highest MGAT enzyme activity among all of the tissues studied, the gene encoding the enzyme has not been identified so far. In the present studies, we report the identification and characterization of a mouse intestinal MGAT, MGAT2. Transient expression of MGAT2 in AV-12, COS-7, and Caco-2 cells led to a more than 70-, 30-, and 35-fold increase in the synthesis of diacylglycerol, respectively. MGAT2 expressed in mammalian cells can catalyze the acylation of rac-1-, sn-2-, and sn-3-monoacylglycerols, and the enzyme prefers monoacylglycerols containing unsaturated fatty acyls as substrates. MGAT2 also demonstrates weak DGAT activity, which can be distinguished from its MGAT activity by detergent treatment that abolishes DGAT but not MGAT activity. We also analyzed the biochemical features of MGAT2 and demonstrated homogenate protein-, time-, and substrate concentration-dependent MGAT enzyme activity in transiently transfected COS-7 cells. Northern blot analysis indicates that the mouse MGAT2 is most abundantly expressed in the small intestine, suggesting that MGAT2 may play an important role in dietary fat absorption.
The feasibility of quantitative MRI of perivascular spaces at 7T.

Abstract Background Dilated brain perivascular spaces (PVSs) are found to be associated with many conditions, including aging, dementia, and Alzheimer's disease (AD). Conventionally, PVS assessment is mainly based on subjective observations of the number, size and shape of PVSs in MR images collected at clinical field strengths (≤3 T). This study tests the feasibility of imaging and quantifying brain PVS with an ultra-high 7 T whole-body MRI scanner. New method 3D high resolution T 2 -weighted brain images from healthy subjects ( n = 3) and AD patients ( n = 5) were acquired on a 7 T whole-body MRI scanner. To automatically segment the small hyperintensive fluid-filling PVS structures, we also developed a quantitative program based on algorithms for spatial gradient, component connectivity, edge-detection, k -means clustering, etc., producing quantitative results of white matter PVS volume densities. Results The 3D maps of automatically segmented PVS show an apparent increase in PVS density in AD patients compared to age-matched healthy controls due to the PVS dilation (8.0 ± 2.1 v/v% in AD vs. 4.9 ± 1.3 v/v% in controls, p Comparison with existing method We demonstrated that 7 T provides sufficient SNR and resolution for quantitatively measuring PVSs in deep white matter that is challenging with clinical MRI systems (≤3 T). Compared to the conventional visual counting and rating for the PVS assessment, the quantitation method we developed is automatic and objective. Conclusions Quantitative PVS MRI at 7 T may serve as a non-invasive and endogenous imaging biomarker for diseases with PVS dilation.
Endocrinopathic laminitis in the horse

Protracted laminitis and the resultant stress often results in prolonged, elevated cortisol secretion and this may contribute to the persistence and refractoriness of laminitis. Cushing’s disease is a condition in which increased secretion of pituitary pars intermedia-derived pro-opiomelanocortin (POMC) peptides leads to perpetually enhanced adrenal secretion of cortisol (hyperadrenocorticism), the physiological glucocorticoid (GC) in the equine species. The vasoconstrictive responses of equine digital arteries to catecholamines is potentiated by GCs leading to interference with hoof lamellar perfusion. The level of the steroid-transforming enzyme, 11β-hydroxysteroid dehydrogenase type 1 is sometimes elevated in hoof lamellar tissues during laminitis as a result of locally high cortisol concentrations within hoof lamellae. Obesity has been shown to be a significant risk factor for the development of laminitis. Obesity-associated laminitis may be similar to the metabolic syndrome (MS) in obese humans. Development of MS is a risk factor in humans for stroke and atherosclerosis and there may be a similar risk for laminitis in horses. GCs cause insulin resistance (IR) by inhibiting the action of insulin thus promoting the availability of glucose for cells in the CNS and other cells that do not depend on insulin for glucose uptake. GCs may impair lamellar perfusion by direct action on vascular smooth muscle and indirectly by causing IR. Equine hoof lamellar keratinocytes appear to have an exceptionally high glucose requirement and maintenance of the lamellar may rely on glucose delivery to and uptake by these keratinocytes. Chronic IR, characterized by hyperglycemia and hyperinsulinemia, subjects cells that are not dependent on insulin for glucose uptake to relatively high glucose levels over time. Glucotoxic endotheliopathy is characterized by increased production of endothelin-1 and reduced release of NO by endothelial cells and these constricting factors may impair lamellar perfusion and risk of laminitis. Horse owners and veterinarians should recognize that obesity is associated with multiple endocrinological changes that might predispose to laminitis. Feeding high glycemic index rations during long periods of physical inactivity promotes the development of obesity. A diagnosis of metabolic syndrome (MS) should be considered in horses with abnormal body fat distribution and laminitis. Identification of IR represents the most useful clinical approach to diagnosing MS in horses and rations for horses with MS should have a low glycemic index. Diagnosis of pituitary pars intermedia dysfunction (PPID) in teenage (and younger) horses before the development of the “classic” signs of hirsutism and weight loss is being reported more commonly using the e-ACTH criterion. Therefore, veterinary diagnosticians must be careful to differentiate whether obese teenage horses might be affected with either or both IR and PPID before the appearance of the more “classic” Cushing’s phenotype is evident. The extent to which these two endocrinological disturbances are related deserves further investigation.
Behavioral phenotype of sex chromosome aneuploidies: 48,XXYY, 48,XXXY, and 49,XXXXY

Sex chromosomal aneuploidy is the most common disorder of sex chromosomes in humans, with an incidence of 1 in 400 newborns. The addition of more than one extra X and/or Y chromosome to a normal male karyotype is less frequent and has its own distinctive physical and behavioral profile. This study examines the behavioral similarities and differences in individuals with 48,XXYY compared to 48,XXXY and 49,XXXXY. The participants include 11 males with 48,XXYY and 13 males with 48,XXXY and 49,XXXXY. Using the Vineland Adaptive Behavior, the Achenbach Child Behavior Checklist, and the Reiss Personality Profiles, parents are asked to characterize the behavior and personality of their boys with sex chromosome tetrasomy and pentasomy. Males with 48,XXYY have higher overall adaptive scales in daily living skills, socialization, and communication compared to males with 48,XXXY and 49,XXXXY. Both groups are at risk for maladaptive behavior, although 48,XXYY males are at a higher risk for internalizing and externalizing symptoms. 48,XXXY and 49,XXXXY function at a lower cognitive level and their behavior is often immature for their chronological age. Both groups display interests in helping others, but have a low tolerance for being rejected or teased. Specific recommendations and interventional strategies are provided for individuals with 48,XXYY, 48,XXXY, and 49,XXXXY.