cssi/SciSciGPT-SciSciNet huggingface dataset:
Efficient algorithms for incremental utility mining

Temporal data mining is the activity of finding interesting correlations or patterns in large temporal data sets. On the other hand, utility mining aims at identifying the itemsets with high utilities. In 2006, Tseng et al. introduced the temporal utility mining which is extended from both temporal association rule mining and utility mining. In this study, we investigated the incremental utility mining which can identify all high temporal utility itemsets in a specified time period on an incremental transaction database. Two efficient algorithms, Incremental Utility Mining (IUM) and Fast Incremental Utility Mining (FIUM), were proposed. The experimental results also showed that both algorithms are efficient.
Prediction of Expected Red-Light-Running Frequency at Urban Intersections

Statistics consistently indicate that red-light running has become a significant safety problem throughout the United States. Comprehensive guidelines for treating red-light running at problem intersections have been developed. Unfortunately, these guidelines do not include a tool or technique for quantitatively determining if a problem exists and if a countermeasure is truly effective. The objective of this work is to describe the development and calibration of such a tool. The calibrated prediction model developed for this research indicates that red-light running increases with flow rate, speed, and dense platoons arriving at the end of the phase. It was also found that red-light running decreases with increasing cycle length and cross-street width, and when back plates are used on the signal heads. Uses for the calibrated model are described.
Direct Load Control: Relationships Between Electric Utility Experiences/Assessments and System Characteristics

In the past decade the electric utility industry, motivated by the need to control spiralling production costs, has expended considerable effort on the assessment and analysis of Load Management (LM) - Direct Load Control (DLC), Time-Of-Day (TOD) pricing, Electric Thermal Storage (ETS), etc. The impact of DLC on a utility's operations depends on the strategies used and system characteristics. However, the growing body of published literature on utility experiences and assessments of DLC indicates that relationships are emerging between system characteristics and the impacts of an DLC strategy.
Marx's classification of economic systems and the soviet economy

(1971). Marx's classification of economic systems and the soviet economy. Soviet Studies: Vol. 23, No. 1, pp. 96-102.
A genetic screen in Myxococcus xanthus identifies mutants that uncouple outer membrane exchange from a downstream cellular response

Upon physical contact with sibling cells, myxobacteria transiently fuse their outer membranes (OMs) and exchange OM proteins and lipids. From previous work, TraA and TraB were identified to be essential factors for OM exchange (OME) in donor and recipient cells. To define the genetic complexity of OME, we carried out a comprehensive forward genetic screen. The screen was based on the observation that Myxococcus xanthus nonmotile cells, by a Tra-dependent mechanism, block swarm expansion of motile cells when mixed. Thus, mutants defective in OME or a downstream responsive pathway were readily identified as escape flares from mixed inocula seeded on agar. This screen was surprisingly powerful, as we found >50 mutants defective in OME. Importantly, all of the mutations mapped to the traAB operon, suggesting that there may be few, if any, proteins besides TraA and TraB directly required for OME. We also found a second and phenotypically different class of mutants that exhibited wild-type OME but were defective in a responsive pathway. This pathway is postulated to control inner membrane homeostasis by covalently attaching amino acids to phospholipids. The identified proteins are homologous to the Staphylococcus aureus MprF protein, which is involved in membrane adaptation and antibiotic resistance. Interestingly, we also found that a small number of nonmotile cells were sufficient to block the swarming behavior of a large gliding-proficient population. This result suggests that an OME-derived signal could be amplified from a few nonmotile producers to act on many responder cells.
Iron‐mediated Cycloaddition Reactions for Fe(1,3‐Butadiene)2L+ (L=Ethyne, Propyne) Complexes in the Gas Phase. Butadiene/Butadiene Versus Butadiene/Alkyne Cycloaddition

Competitive iron-mediated cycloaddition of butadiene with butadiene versus cycloaddition of butadiene with alkynes in Fe(C4H6)
Growing the Earth's D″ layer: Effect of density variations at the core‐mantle boundary

The D″ region of the mantle has been interpreted as a variable-thickness layer of hot, chemically heterogeneous material at the base of the mantle. This paper reports the results of numerical simulations testing whether growth of a chemically distinct layer at the base of the mantle is possible by influx of molten iron alloy from the core to the mantle. A finite-element model of thermo-chemical mantle convection was used to simulate exchange of material between the mantle and core. Growth of a significant layer at the base of the mantle depends on several factors; we focus on the effect of density of the material in the chemical boundary layer. Relatively low density material was swept away from the core-mantle boundary by mantle upwellings. Very high density material, in contrast, was not swept away, but flowed into the mantle too slowly to form a layer as thick as D″. For moderate density contrasts between material in a chemical boundary layer and the overlying mantle, a laterally heterogeneous layer formed. The stable layer results in an elevated temperature contrast between the core and the mantle. High temperatures in this layer are associated with broad regions of elevated temperature in the overlying mantle.
Interactions of N-stearoyl sphingomyelin with cholesterol and dipalmitoylphosphatidylcholine in bilayer membranes

Differential scanning calorimetry and x-ray diffraction have been utilized to investigate the interaction of N-stearoylsphingomyelin (C18:0-SM) with cholesterol and dipalmitoylphosphatidylcholine (DPPC). Fully hydrated C18:0-SM forms bilayers that undergo a chain-melting (gel -->liquid-crystalline) transition at 45 degrees C, delta H = 6.7 kcal/mol. Addition of cholesterol results in a progressive decrease in the enthalpy of the transition at 45 degrees C and the appearance of a broad transition centered at 46.3 degrees C; this latter transition progressively broadens and is not detectable at cholesterol contents of >40 mol%. X-ray diffraction and electron density profiles indicate that bilayers of C18:0-SM/cholesterol (50 mol%) are essentially identical at 22 degrees C and 58 degrees C in terms of bilayer periodicity (d = 63-64 A), bilayer thickness (d rho-p = 46-47 A), and lateral molecular packing (wide-angle reflection, 1/4.8 A-(1)). These data show that cholesterol inserts into C18:0-SM bilayers, progressively removing the chain-melting transition and altering the bilayer structural characteristics. In contrast, DPPC has relatively minor effects on the structure and thermotropic properties of C18:0-SM. DPPC and C18:0-SM exhibit complete miscibility in both the gel and liquid-crystalline bilayer phases, but the pre-transition exhibited by DPPC is eliminated at >30 mol% C18:0-SM. The bilayer periodicity in both the gel and liquid-crystalline phases decreases significantly at high DPPC contents, probably reflecting differences in hydration and/or chain tilt (gel phase) of C18:0-SM and DPPC.
Effects of deuterium on the kinetics of beef heart mitochondrial ATPase

A study was done examining the steady-state kinetics of F1-catalyzed ATP and ITP hydrolyses in the presence or absence of D2O as a function of temperature. The steady-state kinetic parameters kcat and kcat/Km were obtained. For ATP hydrolysis, kcat/Km was independent of temperature in the presence or absence of D2O, while kcat/Km for ITP hydrolysis increased in both cases. The relative magnitudes of change of kcat and kcat/Km in the presence and absence of D2O over the temperature range studied were much different for the cases of ATP and ITP hydrolysis. A normal isotope effect was observed in plots of kcat H2O/kcat D2O versus temperature for ATP hydrolysis, which increased then leveled off as temperature increased. An inverse isotope effect at low temperatures changed to a normal isotope effect and increased dramatically as temperature increased during ITP hydrolysis. The results are discussed in terms of the nature and location of the rate-limiting steps in the reaction mechanisms.
Estimation of Variance of the Ratio Estimator.

SUMMARY A general class of estimators of the variance of the ratio estimator is considered, which includes two standard estimators vo and v2 and approximates another estimator VH suggested by Royall & Eberhardt (1975). Asymptotic expansions for the variances and biases of the proposed estimators are obtained. Based on this we obtain optimal variance estimators in the class and compare the relative merits of three estimators vo, v1 and v2 without any model assumption. Under a simple regression model a more definite comparison of vo, v1 and v2 is made in terms of variance and bias. Some key word8: Asymptotic expansion; Bias; Optimal variance estimator; Ratio estimator; Superpopulation; Variance.
Asymptotic Formula for Solutions of l2-Perturbed Linear Delay Difference Systems

Abstract The aim of this paper is to obtain an asymptotic formula for each solution of a l 2 -perturbed linear delay difference system. The results obtained here extend some earlier results for ordinary difference equations and are parallel to some recent results for delay differential equations.
Negative Regulation of Chondrocyte Differentiation by Transcription Factor AP-2α†

This study investigated the role of transcription factor AP-2α in chondrocyte differentiation in vitro. AP-2α mRNA declined during differentiation, and overexpression of AP-2α inhibited differentiation. The results demonstrated that AP-2α plays a negative role in chondrocyte differentiation. Introduction: Transcription factor AP-2α has been detected in growth plate and articular chondrocytes and has been shown to regulate cartilage matrix gene expression in vitro. However, the precise functional role of AP-2α in chondrocyte differentiation is not known. In this study, we assessed the expression and the function of AP-2α in chondrocyte differentiation of ATDC5 cells. Materials and Methods: Chondrocyte differentiation of ATDC5 cells was induced with insulin or transforming growth factor β (TGF-β). Proteoglycan production was assessed by alcian blue staining, and expression levels of chondrocyte marker genes and AP-2 gene family were determined by quantitative real time reverse transcriptase-polymerase chain reaction (RT-PCR). Overexpression of AP-2α in ATDC5 cells was accomplished by retroviral infection. Infected cells were selected for G418 resistance and pooled for further analysis. Results and Conclusions: Quantitative real time RT-PCR analysis showed that among the four members of the AP-2 gene family, AP-2α mRNA was the most abundant. AP-2α mRNA levels progressively declined during the differentiation induced by either insulin or TGF-β treatment. Retroviral expression of AP-2α in ATDC5 cells prevented the formation of cartilage nodules, suppressed the proteoglycan production, and inhibited the expression of type II collagen, aggrecan, and type X collagen. Expression profile analysis of key transcription factors involved in chondrogenesis showed that overexpression of AP-2α maintained the expression of Sox9 but suppressed the expression of Sox5 and Sox6. Taken together, we provide, for the first time, molecular and cellular evidence suggesting that AP-2α is a negative regulator of chondrocyte differentiation.
Heat transfer by radiation through porous insulations

Radiant transfer through fibrous and foamed insulating materials was investigated theoretically and experimentally. Transmission measurements were made under isothermal conditions with a black-body source varying from 200 to 800 deg F. Bulk density and fiber and pore size were also varied. These data were interpreted successfully in terms of a simple theoretical model. The results provide design information and define the contributions of the several mechanisms of transfer. (auth)
A thermodynamic model of slip propagation

Presentation d'un modele expliquant la signification des grandes valeurs pour le vecteur de Burgers residuel inhibant la propagation du glissement. Ce modele considere aussi la thermodynamique associee a la nucleation et croissance des boucles de dislocations, observee par microscopie electronique en transmission dans le laiton
Etiology of keratogenic metaplasia in the chorioallantoic membrane.

The effects of elevated O2 and CO2 concentrations on the occurrence of experimental keratogenic metaplasia in the chorion of the chick embryo were examined. Exposure to oxygen resulted in advanced keratinization of the chorion; carbon dioxide at elevated concentrations, in mixtures with air or oxygen, repressed the appearance of metaplastic changes, and the chorion retained its respiratory characteristics. The evidence reported here suggests that reduction of the CO2 content in the gaseous environment of the chorion is causally contributory to the onset of the metaplastic events.
Archaeal Guide RNAs Function in rRNA Modification in the Eukaryotic Nucleus

In eukaryotes, many Box C/D small nucleolar RNAs base pair with ribosomal RNA through short complementary guide sequences, thereby marking up to 100 individual nucleotides of ribosomal RNA for 2'-O-methylation. Function of the eukaryotic Box C/D RNAs depends upon interaction with at least six known proteins. Box C/D RNAs are not known to exist in Bacteria but were recently identified in Archaea by biochemical analysis and computational genomic screens and have likely evolved independently in Archaea and Eukarya for more than 2000 million years. We have microinjected Box C/D RNAs from Pyrococcus furiosus, a hyperthermophilic archaeon, into the nuclei of oocytes from the aquatic frog Xenopus laevis. Our results show that Box C/D RNAs derived from this prokaryote are retained in the nucleus, localize to nucleoli, and interact with the X. laevis Box C/D RNA binding proteins fibrillarin, Nop56, and Nop58. Furthermore, we have demonstrated the ability of archaeal Box C/D RNAs to direct site-specific 2'-O-methylation of ribosomal RNA. Our studies have revealed the remarkable ability of archaeal Box C/D RNAs to assemble into functional RNA-protein complexes in the eukaryotic nucleus.
Protease inhibitors as immunomodulatory drugs for HIV infection.

More than 20 drugs from four therapeutic drug classes are widely available for the management of human immunodeficiency virus (HIV) infection, with promising drugs from two new drug classes expected to be approved by the US Food and Drug Administration (FDA) in mid-to-late 2007 (Table 1). When used in combination, these drugs can lead to durable and perhaps indefinite suppression of viral replication. Clinical Pharmacology & Therapeutics (2007) 82, 248–250. doi:10.1038/sj.clpt.6100205
Type I glycogen storage diseases: disorders of the glucose-6-phosphatase/glucose-6-phosphate transporter complexes

Disorders of the glucose-6-phosphatase (G6Pase)/glucose-6-phosphate transporter (G6PT) complexes consist of three subtypes: glycogen storage disease type Ia (GSD-Ia), deficient in the liver/kidney/intestine-restricted G6Pase-α (or G6PC); GSD-Ib, deficient in a ubiquitously expressed G6PT (or SLC37A4); and G6Pase-β deficiency or severe congenital neutropenia syndrome type 4 (SCN4), deficient in the ubiquitously expressed G6Pase-β (or G6PC3). G6Pase-α and G6Pase-β are glucose-6-phosphate (G6P) hydrolases with active sites lying inside the endoplasmic reticulum (ER) lumen and as such are dependent upon the G6PT to translocate G6P from the cytoplasm into the lumen. The tissue expression profiles of the G6Pase enzymes dictate the disease's phenotype. A functional G6Pase-α/G6PT complex maintains interprandial glucose homeostasis, while a functional G6Pase-β/G6PT complex maintains neutrophil/macrophage energy homeostasis and functionality. G6Pase-β deficiency is not a glycogen storage disease but biochemically it is a GSD-I related syndrome (GSD-Irs). GSD-Ia and GSD-Ib patients manifest a common metabolic phenotype of impaired blood glucose homeostasis not shared by GSD-Irs. GSD-Ib and GSD-Irs patients manifest a common myeloid phenotype of neutropenia and neutrophil/macrophage dysfunction not shared by GSD-Ia. While a disruption of the activity of the G6Pase-α/G6PT complex readily explains why GSD-Ia and GSD-Ib patients exhibit impaired glucose homeostasis, the basis for neutropenia and myeloid dysfunction in GSD-Ib and GSD-Irs are only now starting to be understood. Animal models of all three disorders are now available and are being exploited to both delineate the disease more precisely and develop new treatment approaches, including gene therapy.
Platelet activating factor (PAF) in memory formation: role as a retrograde messenger in long-term potentiation

Abstract Long-term potentiation (LTP) is a neurophysiological process that has been implicated in memory formation. The elevation of intracellular Ca 2+ levels in postsynaptic neurons, an essential step in the induction of LTP in the hippocampus, can lead to activation of the enzyme acetyl-CoA:lyso-PAF acetyltransferase that is required for PAF synthesis in neurons. Thus, during the induction of LTP, stimulation of Ca 2+ influx by glutamate receptors would lead to a postsynaptic increase in PAF biosynthesis. A main target for PAF action in neurons is the stimulation of neurotransmitter release via Ca 2+ -dependent vesicular exocytosis, a process that occurs presynaptically. In this article we describe the evidence obtained to-date for the pre- and postsynaptic events outlined above, and demonstrate for the first time that during the induction of LTP by high-frequency stimulation (HFS) a 9-fold increase in PAF release to the extracellular environment occurs within 60 min following HFS. This finding provides the evidence that PAF can diffuse from postsynaptic sites of synthesis to presynaptic sites of action, and thus function as a retrograde messenger in the induction of LTP. Based on these data, we present a scheme in which postsynaptic glutamate receptors cooperate with presynaptic PAF receptors in a reverberating cycle that can amplify the transmission in a Hebbian synapse.
Political Correlates of Television Viewing

THE DECLINING salience of political parties and the concurrent shift to candidate-centered media campaigns and voting patterns have raised fears of growing manipulation and instability in American politics. The mass media have usually been blamed for the apparently increasing "rootlessness" of the electorate and its abandonment of traditional voting patterns. Yet the evidence attributing these shifts to the media has been inconsistent. A recent review of research on "voter volatility" (Bybee, et al., 1981) concluded that "the volatility literature suggests that the emerging pattern of television as the dominant source of political information has contributed to growing electoral instability" (p. 81). But the authors' own study found no support for the hypothesis. If anything, television viewing was associated with lower rather than higher levels of volatility.
ALPHA DECAY OF NEUTRON-DEFICIENT OSMIUM ISOTOPES.

Abstract Three neutron-deficient isotopes of osmium have been produced by the interaction of 16O ions with erbium targets and observed by their α-decay. They are 172Os, E α = 5.105 MeV , t 1 2 = 19 s ; 173 Os , E α = 4.94 MeV , t 1 2 = 16 s ; and 174 Os , E α = 4.76 MeV , t 1 2 = 45 s . The α/(β++e.c.) branchings for 173Os and 174Os are both 0.02 % and that for 172Os is ≤ 0.3 %.
HEMOLYSIS DURING SULFASALAZINE (S) THERAPY FOR PEDI-ATRIC INFLAMMATORY BOWEL DISEASE

Adverse hematologic reactions to S therapy have been well-documented in isolated IBD patients. In prior reports, hemolysis lias been noted to be infrequent, and has occurred within 2-4 weeks of initiation of therapy or coincident with an increase in dosage. Most have been receiving generally high dosages (>4g/day). These toxic manifestations are generally believed to be associated with a slow-acetylator phenotype. After diagnosing three individuals with S-induced hemolytic anemia occurring from 2 to 30 months after the initiation of therapy, we undertook to study the prevalence of S-induced hemolysis in a group of IBD patients (3-19 y.o.) without evidence of active GI blood loss. Out of 20 patients (15 U.C., 5 Crohn's), nine (45%) exhibited evidence of hemolysis by reticulocyte count (average 6.9%, range 2.4-12.8%) and haptoglobin level (average 10 mg/dl, range 0-30, nl 100-300 mg/dl). The average dosage was only 50 mg/kg/day S with a maximum of 3g/day. Upon cessation of S, hemolysis promptly resolved and the hemoglobin level increased an average of 2.1g/d. Prior observation of this hemolysis was obscured by the common occurrence of anemia and reticulocytosis in IBD, and by the laboratory variability in measurement of reticulocyte count. We conclude that in pediatric IBD patients S-induced hemolysis is common, often late in onset, and occurs with modest dosages. Patients on S-therapy should be followed with routine reticulocyte counts and haptoglobin levels as long as therapy persists.
Determination of the aerosol size distribution from the mobility distribution of the charged fraction of aerosols

Abstract The differential mobility chamber of Knutson and Whitby (1975a) is analyzed in terms of the mobility distribution function, and a new iterative scheme for converting the mobility distribution to a size distribution taking into account multiply charged aerosols is given. The scheme has been verified for trial size distributions and shown to converge rapidly to the correct distribution. A differential mobility chamber has been constructed and data obtained with the instrument demonstrate its utility in obtaining the size distribution of aerosols in the size range from 0.008 to 0.7 μm radius.
The 1997/98 Summer Rainfall Season in Southern Africa. Part II: Model Simulations and Coupled Model Forecasts

Abstract This is the second of a two-part investigation of rainfall in southern Africa during the strong El Nino of 1997/98. In Part I it was shown that widespread drought in southern Africa, typical of past El Nino events occurring between 1950 and 2000, generally failed to materialize during the 1997/98 El Nino, most notably during January–March (JFM) 1998. Here output from three atmospheric general circulation models (AGCMs) forced with observed sea surface temperatures (SSTs) and seasonal forecasts from three coupled models are examined to see to what extent conditions in JFM 1998 could have potentially been anticipated. All three AGCMs generated widespread drought conditions across southern Africa, similar to those during past El Nino events, and did a generally poor job in generating the observed rainfall and atmospheric circulation anomaly patterns, particularly over the eastern and southern Indian Ocean. In contrast, two of the three coupled models showed a higher probability of wetter conditions ...
Airflow control systems for miniature fuel cells

The feasibility of utilizing piezoelectric actuators for air flow control of low-power fuel cells is assessed using an electromechanical model of the actuator and a steady-state model for compressible flow. Expressions for electromechanical efficiency are derived using one-dimensional transducer equations of a piezoelectric actuator coupled to the pressure- volume relationships for an ideal gas. The derivation demonstrates that the mechanical power output and electrical power requirements of the system are a function of the input- output force ratio, the input force normalized to the blocked force of the actuator, and the piezoelectric coupling coefficient. The mechanical efficiency of the closed cycle is constant at 28.6% and the electrical efficiency varies from less than 1% for a coupling coefficient of 0.1 to approximately 8% for a coupling coefficient of 0.5. Expressions for the force, displacement, and work performed during each process of the four-stroke cycle are derived. A numerical example of a 50 Watt fuel cell demonstrates that only 219 mW of real mechanical power is required to deliver the necessary air flow to the fuel cell. Operating frequencies are approximately 600 Hz for actuators with 1 mm free displacement. Dissipation in the power electronics is between 6 and 19 Watts for linear amplifiers but can be reduced to less than 2 Watts for more efficient switching-type power conditioners. This example demonstrates that piezoelectric actuators are a viable technology for fuel cell air flow control when they are used in conjunction with efficient power electronics.
Altitude, oxygen and the definition of bronchopulmonary dysplasia

The definition of bronchopulmonary dysplasia (BPD) among very-low birth weight (VLBW) infants is based upon oxygen requirement at 36 weeks gestation, but oxygen may be required at altitude because of hypoxia. This study determined the effect of altitude on BPD rates. For 63 VLBW infants at high altitude, oxygen concentrations were measured by a hood oxygenation test (HOT) and BPD rates were determined with altitude adjustment. BPD rates before and after altitude adjustment were 71.8 and 26.7%, respectively. Of oxygen-dependent infants analyzed by HOT, 33.3% needed room air. HOT oxygen requirement correlated with gestational age of last apnea episode (r=0.42, P<0.001). Although BPD rates may be adjusted for altitude with the HOT, the test does not accurately predict clinical oxygen need. Persistent requirement for supplemental oxygen beyond that needed in the HOT may be partially due to immaturity of respiratory control mechanisms.
Models for Stereoselective Additions to Chiral Allylic Ethers: Osmium Tetroxide Bis-hydroxylations

Density functional calculations (Becke3LYP/6-31G(d)) on the (3 + 2) transition structures of osmium tetroxide mediated dihydroxylations of chiral allylic ethers show that the stereoselectivity is c...
Impact of an Infusion Model on Social Work Students' Aging Knowledge, Attitudes, and Interests

Abstract This study sought to provide data regarding the use of infusion of gerontological materials throughout curriculums to enhance students' attitudes toward older adults, their knowledge of aging-related issues, and their perceptions of gerontological social work. A quasi-experimental design was used to compare outcomes for graduate social work students who were and those who were not exposed to gerontological infusion. Results indicated that exposed students experienced a greater improvement in their view of aging-related career opportunities and in their belief in the importance of gerontological social work. Treatment group students also showed greater gains in self-rated aging knowledge. Both treatment and control group students had significant gains in a test of aging-related knowledge. Pedagogical implications are discussed.
A 3-year randomized therapeutic trial of nitisinone in alkaptonuria

Alkaptonuria is a rare, autosomal recessive disorder of tyrosine degradation due to deficiency of the third enzyme in the catabolic pathway. As a result, homogentisic acid (HGA) accumulates and is excreted in gram quantities in the urine, which turns dark upon alkalization. The first symptoms, occurring in early adulthood, involve a painful, progressively debilitating arthritis of the spine and large joints. Cardiac valvular disease and renal and prostate stones occur later. Previously suggested therapies have failed to show benefit, and management remains symptomatic. Nitisinone, a potent inhibitor of the second enzyme in the tyrosine catabolic pathway, is considered a potential therapy; proof-of-principle studies showed 95% reduction in urinary HGA. Based on those findings, a prospective, randomized clinical trial was initiated in 2005 to evaluate 40 patients over a 36-month period. The primary outcome parameter was hip total range of motion with measures of musculoskeletal function serving as secondary parameters. Biochemically, this study consistently demonstrated 95% reduction of HGA in urine and plasma over the course of 3 years. Clinically, primary and secondary parameters did not prove benefit from the medication. Side effects were infrequent. This trial illustrates the remarkable tolerability of nitisinone, its biochemical efficacy, and the need to investigate its use in younger individuals prior to development of debilitating arthritis.
Theory of magnetoacoustic transport in modulated quantum Hall systems near ν = 1 / 2

Motivated by the experimental results of Willett et al. [Phys. Rev. Lett. $78,$ 4478 (1997)], we develop a magnetotransport theory for the response of a two-dimensional electron gas (2DEG) in the fractional quantum Hall regime near Landau-level filling factor $\ensuremath{\nu}=1/2$ to the surface acoustic wave (SAW) in the presence of an added periodic density modulation. We assume there exists a composite fermion Fermi surface (CF-FS) at $\ensuremath{\nu}=1/2,$ which is a circle, and we show that the deformation of the circular CF-FS due to the density modulation can be at the origin of the observed transport anomalies for the experimental conditions. Our analysis is carried out particularly for the nonlocal case, which corresponds to the SAW experiments. We introduce a concrete model of a deformed CF-FS. The model permits us to explain anomalous features of the response of the modulated 2DEG to the SAW near $\ensuremath{\nu}=1/2:$ namely, the nonlinear wave-vector dependence of the electron conductivity, the appearance of peaks in the SAW velocity shift and attenuation, and the anisotropy of the effect, all of which originate from contributions to the conductivity tensor due to the regions of the originally circular CF-FS, which are flattened by the applied modulation.
Genetically Engineered Mesenchymal Stem Cells as a Proposed Therapeutic for Huntington’s Disease

There is much interest in the use of mesenchymal stem cells/marrow stromal cells (MSC) to treat neurodegenerative disorders, in particular those that are fatal and difficult to treat, such as Huntington’s disease. MSC present a promising tool for cell therapy and are currently being tested in FDA-approved phase I–III clinical trials for many disorders. In preclinical studies of neurodegenerative disorders, MSC have demonstrated efficacy, when used as delivery vehicles for neural growth factors. A number of investigators have examined the potential benefits of innate MSC-secreted trophic support and augmented growth factors to support injured neurons. These include overexpression of brain-derived neurotrophic factor and glial-derived neurotrophic factor, using genetically engineered MSC as a vehicle to deliver the cytokines directly into the microenvironment. Proposed regenerative approaches to neurological diseases using MSC include cell therapies in which cells are delivered via intracerebral or intrathecal injection. Upon transplantation, MSC in the brain promote endogenous neuronal growth, encourage synaptic connection from damaged neurons, decrease apoptosis, reduce levels of free radicals, and regulate inflammation. These abilities are primarily modulated through paracrine actions. Clinical trials for MSC injection into the central nervous system to treat amyotrophic lateral sclerosis, traumatic brain injury, and stroke are currently ongoing. The current data in support of applying MSC-based cellular therapies to the treatment of Huntington’s disease is discussed.
The Effect of Age on Race-Related Breast Cancer Survival Disparities

Breast cancer survival disparities by race are likely multifactorial. In a small pilot cohort, we demonstrated a statistical interaction between age and race. The purpose of this study was to validate earlier findings in a larger, more diverse cohort and to test the hypothesis that breast cancer survival is influenced by the dependent relationship of age and race. We conducted a retrospective analysis of a multi-institutional breast cancer database for patients treated between 1999 and 2009. Study variables included age and disease stage at diagnosis, race, treatment (surgery, chemotherapy, radiotherapy, hormone therapy) and overall survival. Statistical analysis and regression models were performed by Stata software. A total of 9,249 patients were included in this study. African American, Hispanic, and Asian patients were more likely to present at a younger age with metastases. African American and Hispanic race were associated with increased mortality after adjusting for stage, age, and treatment. A 2-way interaction between age and race was identified in the Cox regression model (p < 0.001). To further define this interaction, a postestimation analysis was performed to determine the predicted relative hazard for each race with age fixed at 40, 50, 60, 70, and 80 years. At younger ages, the predicted relative hazard was significantly higher for both African American and Hispanic race. Despite adjusting for stage and treatment differences, African American and Hispanic race predicted poor survival. The effect of age and treatment on breast cancer survival differs across races. Additional research is needed to accurately determine the reasons for worsened survival.
Androgen inhibits the increases in hypothalamic corticotropin-releasing hormone (CRH) and CRH-immunoreactivity following gonadectomy.

To characterize the effect of androgens on the hypothalamo-pituitary-adrenal (HPA) axis we examined the regulation of corticotropin-releasing hormone (CRH) following gonadectomy and hormone replacemen
Sublethal stress: Impact of solar UV radiation on protein synthesis in the copepod Acartia tonsa

Aquatic organisms respond to environmental challenges such as thermal stress with the rapid induction of highly conserved polypeptides known as stress proteins or heat shock proteins (Hsps). Solar ultraviolet radiation (UVR, 280-400 nm) is an important environmental stressor in marine ecosystems. Here, we present results of experiments conducted with the marine copepod Acartia tonsa to follow the de novo protein synthesis and measure the level of constitutive and inducible isoforms of the Hsp70 gene family of stress proteins after UV exposure. Animals were collected from Tampa Bay, Florida (USA), and exposed to solar radiation (full spectrum), UV-A (320-400 nm) and PAR (400-700 nm), or PAR only, for periods of 0.5-4 h. Controls were kept in the dark. Protein synthesis was robust under all treatments when the copepods were exposed to low solar radiation intensities. Conversely, high solar radiation intensities (both UV-B and UV-A) caused an overall suppression in the protein synthesis of the copepods with no detectable induction of stress-inducible isoforms of Hsps. Immunochemical assays (western blotting) showed that UVR increased levels (3.5-4-fold increase compared to the dark control) of the constitutively expressed 70 kDa heat-shock (Hsc70) protein in A. tonsa, without indication of inducible isoform upregulation.
Ischiofemoral impingement syndrome: a meta-analysis

The aims of this article are to review the imaging characteristics of ischiofemoral impingement (IFI), summarize measurement thresholds for radiologic diagnosis based on a meta-analysis of the literature and raise awareness among radiologists and clinicians of this entity. A PubMed search restricted to the English language containing the keywords “ischiofemoral impingement” and “quadratus femoris MRI” was performed, and citations in these articles were also used to identify a total of 27 studies discussing ischiofemoral impingement. After excluding case reports and non-representative studies, there were five remaining articles including 193 hip MRIs of IFI in 154 subjects (133 female, 21 male) and 135 asymptomatic control hip MRIs from 74 subjects (55 female, 19 male). Additionally, we performed a retrospective database search of pelvic and hip MRI reports from our institution including the terms “quadratus femoris” or “ischiofemoral impingement” from a 9-year period and 24 hip MRIs from 21 patients (18 female, 3 male) with IFI with 5 asymptomatic contralateral control hip MRIs identified. In all, 217 hip MRIs of IFI and 140 control cases were included. A meta-analysis of these hip MRIs was conducted to determine optimal thresholds of the ischiofemoral space (IFS) and quadratus femoris space (QFS) for identifying IFI. Cases of IFI showed significantly smaller IFS and QFS compared to controls (14.91 ± 4.8 versus 26.01 ± 7.98 and 9.57 ± 3.7 versus 15.97 ± 6.07, measured in mm, respectively, p < 0.0001 for both). Pooled analysis revealed that for IFS, using a cutoff of ≤15 mm yielded a sensitivity of 76.9 %, specificity of 81.0 % and overall accuracy of 78.3 %. For QFS, a cutoff of ≤ 10.0 mm resulted in 78.7 % sensitivity, 74.1 % specificity and 77.1 % overall accuracy. IFI is a potential cause of hip pain that can be accurately diagnosed with MRI in conjunction with clinical findings. Using the proposed measurement thresholds may better identify patients with this impingement syndrome so that optimal treatment options can be pursued.
Dioxin induces transcription of fos and jun genes by Ah receptor-dependent and -independent pathways.

Halogenated aromatic hydrocarbons, such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; dioxin), and polycyclic aromatichydrocarbons, such as benzo[a]pyrene, are environmental contaminants that cause many apparently unrelated toxic effects. In a previous study, we have shown that treatment of mouse hepatoma cells with TCDD or B(a)P results in an increase in mRNA levels of the immediate-early protooncogenes c-fos, c-jun, junB, and junD, and the concomitant increase of the DNA-binding activity of the transcription factor AP-1, a dimer of FOS and JUN proteins. To analyze the mechanism of fos/jun activation by TCDD we have used electrophoretic mobility shift and transient expression assays of reporter gene constructs containing response elements for 12-O-tetradecanoyl-phorbol-13-acetate (TRE), serum (SRE), cAMP (CRE), and aromatic hydrocarbons (AhRE) from the fos and jun genes fused to the firefly luciferase gene under the control of the SV40 minimal receptor (AHR) and Ah receptor nuclear translocator (ARNT) promoter. In mouse hepatoma Hepa-1 cells, which have Ah proteins, inclusion of TRE, SIZE, and the AhRE motifs from c-jun and junD, but not CRE or the AhREs from c-fos, fosB, and junB, causes a large TCDD-dependent increase in luciferase expression. In agreement with these results, c-jun and junD, but not c-fos, fosB, and junB AhREs, competed with a canonical Cyp1A1 AhRE for binding to the AHR · ARNT heterodimeric complex. In African Green Monkey CV-1 cells, which lack AHR, expression plasmids with AhRE motifs require coexpression of AHR and ARNT for TCDD to stimulate luciferase expression. In contrast, SRE-containing expression plasmids respond equally well to TCDD whether or not AHR and ARNT are coexpressed. These results suggest that TCDD induces expression of the immediate-early response genes fos and jun by activation of possibly three separate signal transduction pathways, at least one of which does not require a functional Ah receptor complex.
JavaBean-based simulation with operational procedure table (OPT)

Abstract This paper describes an application of operational procedure table (OPT) methodology to web/component-based simulation. Component-based development, which permits use of drag and drop methods, can significantly reduce development time since no coding is required. Furthermore, an OPT component can enhance design efficiency with a tabular format specification for describing the behavior of a system. OPT tabular display helps a user understand associations between inputs and outputs. We introduce the JavaBeans discrete simulation (JBDS) system, which has a library of basic simulation components and the OPT component, to illustrate the combination of component/web-based simulation development and OPT.
A role for intermolecular disulfide bonds in prion diseases

Abstract The key event in prion diseases seems to be the conversion of the prion protein PrP from its normal cellular isoform (PrPC) to an aberrant “scrapie” isoform (PrPSc). Earlier studies have detected no covalent modification in the scrapie isoform and have concluded that the PrPC → PrPSc conversion is a purely conformational transition involving no chemical reactions. However, a reexamination of the available biochemical data suggests that the PrPC → PrPSc conversion also involves a covalent reaction of the (sole) intramolecular disulfide bond of PrPC. Specifically, the data are consistent with the hypothesis that infectious prions are composed of PrPSc polymers linked by intermolecular disulfide bonds. Thus, the PrPC → PrPSc conversion may involve not only a conformational transition but also a thiol/disulfide exchange reaction between the terminal thiolate of such a PrPSc polymer and the disulfide bond of a PrPC monomer. This hypothesis seems to account for several unusual features of prion diseases.
Molecular modelling of conformational changes in solvated αs1-casein peptides

Abstract Computer models of α s1 -casein peptides were simulated in an aqueous environment to compare their conformations as separate peptides with structural features of corresponding regions in the intact α s1 -casein molecular model. Peptide sequences selected for investigation were based on sites of potential cleavage by chymosin and/or plasmin. Four large peptides and several smaller peptide fragments were refined by applying a series of molecular dynamics simulations and energy minimizations. Most peptides adopted conformations that were more compact than the conformations of the corresponding sequences in the intact α s1 -casein model. The results indicated that sequences in the peptides that promote the open, flexible structure of the parent protein are likely to resist formation of new secondary structure during refinement. However, these regions can develop more local flexibility and additional turns because of the high proline content of α s1 -casein. The region in which seven of the eight phosphoserine residues are located maintained its conformation throughout the refinement, but this region adopted a new conformation when phosphoserines were replaced with serines. The results demonstrate the potential for folding in casein peptides and highlight the features that promote the open, extended structures of the caseins.
Glassy Yb0.17Ba0.33Cu0.50 alloy as precursor for the high-Tc oxide superconductor Y1Ba2Cu3Ox

Abstract We describe the preparation by rapid solidification processing (RSP), properties and alloy chemistry of the glassy alloy Yb 0.17 Ba 0.33 Cu 0.50 and its oxidation to form the superconductor Yb 1 Ba 2 Cu 3 O x with T c = 93 K . Processing features and advantages of forming high- T c superconductors via metallic alloy precursors are discussed.
Kinetics of the Oxidation of CaS

The kinetics of the oxidation of dense pellets of CaS by the reaction: $$2CaS(s) + 3O_2 (g) \to 2CaO(s) + 2SO_2 (g)$$ was examined by continuous thermogravimetric analysis. The experiments covered a temperature range of 1673 to 1853 K, Ar-O2-SO2 mixtures varying from 1 to 40 pct O2 and 0 to 20 pct SO2, and gas velocities ranging from 20 to 57 cm/s at the reaction temperature. Analysis of the data shows that the initial rate of the reaction is controlled by the mass transfer of O2 through the gaseous boundary layer of the pellet and is subsequently controlled by the diffusion of O2 through the porous layer of the reaction products. To verify these results, the permeation rates of SO2 through the reaction products were measured at room temperature and compared to values calculated from the thermogravimetric data.
Recall, recognition, and the hippocampus: Reply to Yonelinas et al. (2004)

Two recent studies disagree about whether recall is more impaired than recognition (and recollection more than familiarity) in patients with damage limited to the hippocampus (Manns, Hopkins, Reed, Kitchener, & Squire, 2003; Yonelinas et al., 2002). Wixted and Squire (2004) pointed out that the disagreement about recall and recognition stems entirely from an outlying recognition score obtained by 1 of 55 control subjects in Yonelinas et al. (2002). In their comment on our paper, Yonelinas et al. (2004) minimize the importance of this result and argue that the role of the hippocampus in recollection and familiarity is best studied using different methods that attempt to measure these processes directly. Here, we argue that the recall versus recognition comparison is the strongest test because it relies on the fewest controversial assumptions, and that the other approaches explored by Yonelinas et al. (2002) rely on questionable, theory-laden assumptions. We also rehearse the reasons for concluding that the patients studied by Manns et al. (2003) have damage limited to the hippocampal region (hippocampus proper, dentate gyrus, and subiculum), and we emphasize that important questions remain about the patients studied by Yonelinas et al. (2002), inasmuch as no neuroanatomical information and minimal neuropsychological information has been provided.
Distribution of ADPase activity in the lactating rat mammary gland and its possible role in an ATP cycle in the Golgi apparatus

Abstract A Ca 2+ Mg 2+ -stimulated ADPase has been found to occur in the lactating rat mammary gland. The enzyme is membrane associated and occurs in mitochondrial, microsomal, and Golgi apparatus fractions. The pH activity curves for the Golgi apparatus and microsomal fractions display two distinct maxima, one at pH 6.3 and one at pH 7.4. Studies with inhibitors and activators indicate that the enzyme is similar to ADPases found in other tissues and is distinct from the uridine nucleoside diphosphatase previously reported in the mammary Golgi apparatus. The occurrence of ADPase in the Golgi apparatus indicates a possible role for this enzyme in the milk secretory process, while the microsomal enzyme could be involved in extracellular activities.