Miracle-dz/UniFAR-FTUs huggingface dataset:
The thermostable α‐l‐rhamnosidase RamA of Clostridium stercorarium: biochemical characterization and primary structure of a bacterial α‐l‐rhamnoside hydrolase, a new type of inverting glycoside hydrolase

An α‐l‐rhamnosidase clone was isolated from a genomic library of the thermophilic anaerobic bacterium Clostridium stercorarium and its primary structure was determined. The recombinant gene product, RamA, was expressed in Escherichia coli, purified to homogeneity and characterized. It is a dimer of two identical subunits with a monomeric molecular mass of 95 kDa in SDS polyacrylamide gel electrophoresis. At pH 7.5 it is optimally active at 60°C and insensitive to moderate concentrations of Triton X100, ethanol and EDTA. It hydrolysed p‐nitrophenyl‐α‐l‐rhamnopyranoside, naringin and hesperidin with a specific activity of 82, 1.5 and 0.46 U mg−1 respectively. Hydrolysis occurs by inversion of the anomeric configuration as detected using 1H‐NMR, indicating a single displacement mechanism. Naringin was hydrolysed to rhamnose and prunin, which could further be degraded by incubation with a thermostable β‐glucosidase. The secondary structure of RamA consists of 27% α‐helices and 50% β‐sheets, as detected by circular dichroism. The primary structure of the ramA gene has no similarity to other glycoside hydrolase sequences and possibly is the first member of a new enzyme family.
Epidermal growth factor receptor, c-erbB2 and c-erbB3 receptor interaction, and related cell cycle kinetics of SK-BR-3 and BT474 breast carcinoma cells.

BACKGROUND Receptors belonging to the epidermal growth factor receptor (EGFR) family transfer extracellular signals by homotypic and heterotypic receptor interaction and cross-activation. Cell differentiation, death, and proliferation are regulated via these receptor-tyrosine-kinases. However, the initial mechanisms that lead to signal specificity and diversity, which cause a defined cellular response, are incompletely understood. We investigated the recruitment of receptor complexes in two c-erbB2-overexpressing breast carcinoma cell lines, SK-BR-3 and BT474, after ligand binding and its effects on intracellular signal transduction and cell cycle regulation. METHODS In order to analyze the coaggregation of receptors on the cell surface induced by specific growth factor treatment, we used the flow cytometric Foerster-type fluorescence resonance energy transfer (FRET) technique. Cell cycle kinetics were monitored flow cytometrically via the anti-BrdU technique and acitivation of intracellular signal cascades was analyzed by Western blotting. RESULTS After stimulation with EGF BT474, but not SK-BR-3, cells formed EGFR/c-erbB2 receptor complexes. Neither EGF nor heregulin (HRG) induced c-erbB2/c-erbB3 receptor complexes in BT474. However, SK-BR-3 cells exhibited a high amount of c-erbB2/c-erbB3 heterodimers even without growth factor stimulation which could be elevated after prolonged EGF and HRG treatment. In both cell lines, mitogen-activated protein kinase (MAPK) phosphorylation was detectable after short-term and prolonged EGF and HRG treatment. However, only SK-BR-3 cells showed a constitutive activation of both protein kinase B (PKB)/Akt and MAPK signaling pathways. Growth factor treatment caused an amplified PKB/Akt activation in this cell line. The induction of EGFR/c-erbB2 complexes in BT474 was associated with shortening of the G1-phase of the cell cycle. In contrast, the concurrent activation of MAPK and PKB/Akt by EGF treatment led to an inhibition of proliferation in SK-BR-3 and can be attributed to missing EGFR/c-erbB2 heterodimers. HRG was a strong stimulator of proliferation in both cell lines. CONCLUSIONS We show that in the presence of identical amounts of c-erbB2 receptors, the ligand-induced cellular response differs significantly. These differences were mediated by variances in signal transduction, most likely due to different recruitment of heterotypic receptor complexes. Overall, there is strong evidence that c-erbB2 receptor overexpression in breast cancer cells is an insufficient marker to determine cellular response in terms of cell proliferation. 2001.
An Integrated Indenter-ARFI Imaging System for Tissue Stiffness Quantification

The goal of this work is to develop and characterize an integrated indenter-ARFI (acoustic radiation force impulse) imaging system. This system is capable of acquiring matched datasets of ARFI images and stiffness profiles from ex vivo tissue samples, which will facilitate correlation of ARFI images of tissue samples with independently-characterized material properties. For large and homogeneous samples, the indenter can be used to measure the Young's moduli by using Boussinesq's solution for a load on the surface of a semi-infinite isotropic elastic medium. Experiments and finite element method (FEM) models were designed to determine the maximum indentation depth and minimum sample size for accurate modulus reconstruction using this solution. Applying these findings, indentation measurements were performed on three calibrated commercial tissue-mimicking phantoms and the results were in good agreement with the calibrated stiffness. For heterogeneous tissue samples, indentation can be used independently to characterize relative stiffness variation across the sample surface, which can then be used to validate the stiffness variation in registered ARFI images. Tests were performed on heterogeneous phantoms and freshly-excised colon cancer specimens to detect the relative stiffness and lesion sizes using the combined system. Normalized displacement curves across the lesion surface were calculated and compared. Good agreement of the lesion profiles was observed between indentation and ARFI imaging.
Nucleotide sequence at the junction between the nonstructural and the structural genes of the semliki forest virus genome

The nucleotide sequence at the junction between the nonstructural and the structural genes of the Semliki Forest virus 42S RNA genome has been determined from cloned cDNA. With the aid of S1-mapping, we have located the 5' end of the viral 26S RNA on this sequence. The 26S RNA is homologous to the 3' end of the 42S RNA and is used as a messenger for the structural proteins of the virus. The nucleotide sequence in the noncoding 5' region of the 26S RNA (51 bases) was thus established, completing the primary structure of the 26S RNA molecule (for earlier sequence work, see Garoff et al., Proc. Natl. Acad. Sci. U.S.A. 77:6376-6380, 1980, and Garoff et al., Nature (London) 288:236-241, 1980). An examination of the nucleotide sequences upstream from the initiator codon for the structural proteins on the 42S RNA genome shows that all reading frames are effectively blocked by stop codons, which means that the nonstructural genes in the 5' end of the 42S RNA molecule do not overlap with the structural ones at the 3' end of the molecule.
Multi-Regional Growth, Agglomeration and Land Values in a Generalized Heckscher-Ohlin Trade Model

This paper builds a general equilibrium interregional trade model with any number of regional economies by unifying the Solow-Uzawa growth and Heckscher-Ohlin (H-O) trade theories. We study the roles of population, land, preferences and technological differences between regions in determining dynamics of national wealth, patterns of interregional trade, economic structures, and income and wealth distributions between different regional households in a general equilibrium dynamic framework. The paper deals with endogenous wealth accumulation, land values, residential land-use, and labor and capital distribution between sectors and between regions under perfectly competitive markets and free trade. Each region has three sectors, producing one national homogenous tradable capital good, specifying in producing one tradable commodity, and supplying non-tradable goods and services. We simulate the model to show existence of an equilibrium point and movement of the interregional economy. We examine the effects on the equilibrium point in exogenous changes of the land, the population, a region’s amenities, and the preferences for a regional good, saving, housing, and residential density.
RGS7 complex formation and colocalization with the Gβ5 subunit in the adult rat brain and influence on Gβ5γ2‐mediated PLCβ signaling

This study describes the colocalized distribution and dimeric complex formation between RGS7, a GTPase‐activating protein for several heterotrimeric Gα protein families, and the Gβ5 subunit in the adult rat brain. Confocal dual immunofluorescence labeling studies indicated a broad regional specificity in the cellular coexpression between RGS7 and Gβ5 within the cerebral cortical layers I and V–VI, hippocampal formation, caudate‐putamen, medial habenula, most thalamic nuclei, and cerebellar molecular and granular layers. In all instances, Gβ1–β4 immunoreactivities exhibited no observable colocalization with RGS7, despite their widespread codistribution throughout similar neuronal networks. Coimmunoprecipitation studies confirmed the selective protein–protein interaction between RGS7 and Gβ5 within brain regions that displayed immunohistochemical colocalization. The influence of RGS7 to modulate Gβ5γ2‐mediated phosphatidyl inositol (PI) production was examined in COS‐7‐cotransfected cells. In the presence of Gβ5γ2 only, intracellular PI accumulation was increased by 25% above basal levels; addition of RGS7 produced no significant alteration in Gβ5γ2‐mediated PI accumulation. A similar trend was exhibited when full‐length RGS7 was substituted with an RGS7 construct lacking the Gβ5‐interacting region (G protein gamma‐like domain; GGL domain) or with RGS4. In conclusion, RGS7/Gβ5 dimers occurred within most brain regions in which both proteins were cellularly coexpressed. However, an influence of RGS7 on Gβ5γ2‐mediated PLCβ signaling activity was not apparent, athough this was in COS‐7 cell transfection studies. J. Neurosci. Res. 60:58–64, 2000 © 2000 Wiley‐Liss, Inc.
Eradication of Methicillin-Resistant Staphylococcus aureus and of Enterobacteriaceae Expressing Extended-Spectrum Beta-Lactamases on a Model Pig Farm

ABSTRACT Colonization of livestock with bacteria resistant to antibiotics is considered a risk for the entry of drug-resistant pathogens into the food chain. For this reason, there is a need for novel concepts to address the eradication of drug-resistant commensals on farms. In the present report, we evaluated the decontamination measures taken on a farm contaminated with methicillin-resistant Staphylococcus aureus (MRSA) and Enterobacteriaceae expressing extended-spectrum β-lactamases (ESBL-E). The decontamination process preceded the conversion from piglet breeding to gilt production. Microbiological surveillance showed that the decontamination measures eliminated the MRSA and ESBL-E strains that were detected on the farm before the complete removal of pigs, cleaning and disinfection of the stable, and construction of an additional stable meeting high-quality standards. After pig production was restarted, ESBL-E remained undetectable over 12 months, but MRSA was recovered from pigs and the environment within the first 2 days. However, spa (Staphylococcus aureus protein A gene) typing revealed acquisition of an MRSA strain (type t034) that had not been detected before decontamination. Interestingly, we observed that a farmworker who had been colonized with the prior MRSA strain (t2011) acquired the new strain (t034) after 2 months. In summary, this report demonstrates that decontamination protocols similar to those used here can lead to successful elimination of contaminating MRSA and ESBL-E in pigs and the stable environment. Nevertheless, decontamination protocols do not prevent the acquisition of new MRSA strains.
Hepatic Metallothionein as a Source of Zinc and Cysteine during the First Year of Life

ABSTRACT: Metallothionein, a high cysteine-containing protein, can bind with both essential and nonessential metals and thus play an important role as a metal storage protein and also in the detoxification of toxic metals. Although in the human fetus, levels of trace minerals and metallothionein are very high, their postnatal changes are not well documented. The purpose of the present investigation, therefore, was to quantify the accumulation of metallothionein in premature and full-term infants during the first year of life and to identify factors affecting its accumulation. From 47 postmortem samples, it was determined that hepatic metallothionein levels were highest in newborn premature and full-term infants falling to levels found in older children by 4.4 months of age. Hepatic zinc levels were also highest in the youngest infants, falling with increasing postnatal age. There was a significant positive correlation between zinc and metallothionein at all ages. However, there was a negative correlation between hepatic metallothionein levels and cystathionase activity. Hepatic copper and metallothionein levels were unrelated. The renal concentration of metallothionein, zinc, and copper were significantly lower than corresponding hepatic levels. The fall in hepatic levels of zinc and metallothionein during the first months of life correspond to a period of negative zinc balance and low endogenous cysteine production in the newborn. Thus metallothionein may play an important role as a storage depot for these two essential nutrients during this critical period of active growth.
Measurement of loop-back interference channels for outdoor-to-indoor full-duplex radio relays

A full-duplex relay enhances the end-to-end spectral efficiency compared to a half-duplex relay, provided that the loop-back interference at relays is managed well. In order to study the feasibility of the full-duplex relay, it is crucial to measure and model the loop-back interference channels. This paper presents a measurement campaign of these channels for outdoor-to-indoor communications. A compact relay antenna was developed to serve as a signal repeater between outdoor base stations and indoor users, and was used for the loop-back interference channel measurement. The magnitude of the interference was evaluated by the isolation between the transmit and receive antennas. Measurement results revealed that the isolation in multipath environment was 48 dB in the compact relay antenna, and it could be further reduced by placing the outdoor and indoor antennas in a different position referred to as a separate relay. Combined with an appropriate countermeasure to reduce the interference level, such as an interference canceller, the full-duplex operation of indoor compact relay station was found to be feasible.
An extended Kalman filter based speed and position estimator for Permanent Magnet Synchronous Motor

An Extended Kaiman filter(EKF) based speed and position observer for a PMSM in low and medium speeds is presented in this paper. The estimator is used to control an IPMSM of 1.5 kW, 3000 rpm rating. EKF algorithm is implemented in the stationary αβ reference frame model for PMSM. Design considerations for the Extended Kalman Filter are presented, followed by simulation and experimental results for a VSI fed Interior Permanent Magnet Synchronous Motor (IPMSM). The PMSM is run in complete sensorless mode and the convergence of the EKF algorithm is shown for different arbitrary initial rotor positions.
The Skill Profile of the Employees and the Provision of Flexible Working Hours in the Workplace: A Multilevel Analysis Across European Countries

This article investigates the relationship between the skill profile of the employees (i.e. the percentage of employees in highly skilled jobs) and the provision of flexible working hours in the workplace (i.e. the proportion of employees entitled to adapt, within certain limits, the time when they begin or finish their daily work according to their personal needs or wishes). Analyses draw on the 2009 European Company Survey, conducted on a representative sample (NÂ =Â 26,640) of European establishments in 29 countries. Multilevel mixedâ€ effects linear regressions are used to study to what extent both workplaceâ€ level and nationalâ€ level variables affect this relationship. Findings suggest a strong, positive and nonâ€ linear relationship between the variables under scrutiny, which is moderated, at national level, by both unemployment and trade union density rates.
Specific binding of lactoferrin to Escherichia coli isolated from human intestinal infections

The degrees of human lactoferrin (HLf) and bovine lactoferrin (BLf) binding in 169 Escherichia coli strains isolated from human intestinal infections, and in an additional 68 strains isolated from healthy individuals, were examined in a 125I‐labelled protein binding assay. The binding was expressed as a percentage calculated from the total labelled ligand added to bacteria. The HLf and BLf binding to E. coli was in the range 3.7 to 73.4% and 4.8 to 61.6%, respectively. Enterotoxigenic strains demonstrated a significantly higher HLf binding (median = 19%) than enteropathogenic, enteroinvasive, enterohaemorrhagic strains or normal intestinal E. coli isolates (medians 6 to 9). Enteropathogenic strains belonging to serotypes 044 and 0127 demonstrated significantly higher HLf binding compared to O26, O55, O111, O119 and O126. No significant differences in the degree of HLf or BLf binding were found between aerobactin‐producing and non‐producing strains. The interaction was further characterized in a high Lf‐binding EPEC strain, E34663 (serotype O127). The binding was stable in the pH range 4.0 to 7.5, did not dissociate in the presence of 2M NaCl or 2M urea, and reached saturation within two h. Unlabelled HLf and BLf displaced the 125I‐HLf binding to E34663 in a dose‐dependent manner. Apo‐ and iron‐saturated forms of Lf demonstrated similar binding to E34663. Among various unlabelled subepithelial matrix proteins and carbohydrates tested (in 104‐fold excess) only fibronectin and fibrinogen caused a moderate inhibition of 125I‐HLf binding. According to Scatchard plot analysis, 5,400 HLf‐binding sites/cell, with an affinity constant (Ka) of 1.4 × 10−7 M. , were estimated in strain E34663. These data establish the presence of a specific Lf‐binding mechanism in E. coli.
Microneedle arrays as medical devices for enhanced transdermal drug delivery

In order to exploit the transdermal route for systemic delivery of a wide range of drug molecules, including peptide/protein molecules and genetic material, a means of disrupting the excellent barrier properties of the uppermost layer of the skin, the stratum corneum, must be sought. The use of microneedle (MN) arrays has been proposed as a method to temporarily disrupt the barrier function of the skin and thus enable enhanced transdermal drug delivery. MN arrays consist of a plurality of micron-sized needles, generally ranging from 25 to 2000 µm in height, of a variety of different shapes and composition (e.g., silicon, metal, sugars and biodegradable polymers). The application of such MN arrays to the skin results in the creation of aqueous channels that are orders of magnitude larger than molecular dimensions and, therefore, should readily permit the transport of macromolecules. This article will focus on recent and future developments for MN technology, focusing on the materials used for MN fabrication, the forces required for MN insertion and potential safety aspects that may be involved with the use of MN devices.
Racial disparities in lipid control in patients with diabetes.

OBJECTIVES To describe lipid management over time in a cohort of insured patients with diabetes and evaluate differences between African American and white patients. STUDY DESIGN Automated claims data were used to identify a cohort of 11,411 patients with diabetes in 1997 to 1998. Patients were followed through 2007. METHODS Rates of hypercholesterolemia testing, treatment, and goal attainment were measured annually. Treatment was determined by a claim for lipid-lowering agents, and goal attainment was defined as a low-density lipoprotein cholesterol (LDL-C) level <100 mg/dL. RESULTS During the study period, LDL-C testing increased from 48% to 70% among African American patients and from 61% to 77% among white patients. Treatment with lipid-lowering drugs increased from 23% to 56% among African American patients and 33% to 61% among white patients. The proportion at goal increased from 35% to 76% and from 24% to 59% among white and African American patients, respectively. African American patients were less likely to be tested for LDL-C (odds ratio [OR] 0.79; 95% confidence interval [CI] 0.73-0.86), treated with lipidlowering agents (OR 0.72; 95% CI 0.65-0.80), have their medication dosage altered (OR 0.65; 95% CI 0.59-0.73), or attain LDL-C goal (OR 0.59; 95% CI 0.56-0.63) compared with white patients. CONCLUSIONS Although rates of LDL-C testing, treatment, and goal attainment improved over time, racial disparities in dyslipidemia management continued to exist. Further studies to determine the causes of differences in management by race are warranted.
Comparing the impact of management support on police officers’ perceptions of discretionary power and engagement: Australia, USA and Malta

Abstract This paper uses Social Exchange Theory as a lens for comparing the impact of management support upon police perceptions of discretionary power and employee engagement, across three countries. A survey-based, self-report process collected data from 193 police officers in Australia, 588 from the USA, and 249 from Malta. Structural equation modelling was used to analyse the data. The findings suggest a significantly different management support context across the three countries, as well as significantly different perceptions of discretionary power. Across the three countries, police perceived relatively poor satisfaction with organizational management support and only some engagement levels. However, USA police perceived significantly more discretionary power than the other country samples. These findings provide greater clarity about the link between management support, discretionary power and engagement for the police officers. Since employee engagement likely affects policing outcomes, the findings suggest that poor management support of police officers could negatively affect the provided service. Potential strategies to enhance police engagement include (a) training police managers about how to manage so as to promote greater engagement, and (b) modifying police managers’ performance indicators in line with achieving better police engagement.
Altered middle lamella homogalacturonan and disrupted deposition of (1-->5)-alpha-L-arabinan in the pericarp of Cnr, a ripening mutant of tomato.

Cnr (colorless non-ripening) is a pleiotropic tomato (Lycopersicon esculentum) fruit ripening mutant with altered tissue properties including weaker cell-to-cell contacts in the pericarp (A.J. Thompson, M. Tor, C.S. Barry, J. Vrebalov, C. Orfila, M.C. Jarvis, J.J. Giovannoni, D. Grierson, G.B. Seymour [1999] Plant Physiol 120: 383-390). Whereas the genetic basis of the Cnr mutation is being identified by molecular analyses, here we report the identification of cell biological factors underlying the Cnr texture phenotype. In comparison with wild type, ripe-stage Cnr fruits have stronger, non-swollen cell walls (CW) throughout the pericarp and extensive intercellular space in the inner pericarp. Using electron energy loss spectroscopy imaging of calcium-binding capacity and anti-homogalacturonan (HG) antibody probes (PAM1 and JIM5) we demonstrate that maturation processes involving middle lamella HG are altered in Cnr fruit, resulting in the absence or a low level of HG-/calcium-based cell adhesion. We also demonstrate that the deposition of (1-->5)-alpha-L-arabinan is disrupted in Cnr pericarp CW and that this disruption occurs prior to fruit ripening. The relationship between the disruption of (1-->5)-alpha-L-arabinan deposition in pericarp CW and the Cnr phenotype is discussed.