cssi/SciSciGPT-SciSciNet huggingface dataset:
Abstract #2485: ERK1/2 signaling plays an important role in the topoisomerase II inhibitor induced G2/M checkpoint response

AACR Annual Meeting-- Apr 18-22, 2009; Denver, CO Topoisomerase II inhibitors, such as Etoposide and Doxorubicin, are commonly used radiomimetic chemotherapeutic agents. These drugs can induce G2/M cell cycle arrest which allows time for the cell to repair the damaged DNA. The induction of G2/M arrest involves the activation of ATM and ATR kinases which activate Chk1 and Chk2 kinases respectively. Chk1 and Chk2 inhibit Cdc25 phosphatases from activating Cdc2 kinase that is required for the G2/M transition of the cell cycle. While previous studies have shown that ERK1/2 signaling is required for the induction of G2/M arrest by topoisomerase II inhibitors in MCF-7 breast cancer cells, the role it plays has not been clearly defined. Using the MEK1/2 specific inhibitor U0126 to inhibit ERK1/2 signaling, the data presented in this study shows that ERK1/2 signaling is required for ATR and Chk1 activation and G2/M arrest following exposure to topoisomerase II inhibitors in MCF-7 cells. Consistently knocking down ERK1/2 by siRNA or ATR by shRNA mimics the effect of U0126 resulting in the attenuation of G2/M arrest induction by Doxorubicin. In contrast, inhibiting ERK1/2 signaling with U0126 had no effect on the activation of ATM and Chk2 activity following exposure to topoisomerase II inhibitors. In addition knocking down ATM had no effect on the induction of G2/M arrest by doxorubicin. This data suggests that, though topoisomerase II inhibitors induce both ATR and ATM activity, only ATR mediated signaling which is regulated by ERK1/2 is involved in the induction of G2/M arrest. Citation Information: In: Proc Am Assoc Cancer Res; 2009 Apr 18-22; Denver, CO. Philadelphia (PA): AACR; 2009. Abstract nr 2485.
Action of histamine on eustachian tube function.

Abstract Introduction: The role of allergy in eustachian tube dysfunction is controversial. In this study, allergy was simulated by exposure to histamine, and eustachian tube function testing was performed in an experimental rat model. Methods: Ventilatory function was assessed by measuring passive opening and closing pressures of the eustachian tube after challenge with either transtympanic or intranasal histamine. The mucociliary clearance time of the tubotympanum was assessed by observing dye transport from the middle ear to the nasopharynx after challenge with either transtympanic histamine or control solution. Results: There was a statistically significant increase in passive opening and closing pressures with transtympanic histamine versus intranasal histamine. In addition, mucociliary clearance times of the tubotympanum after transtympanic histamine showed a statistically significant increase when compared with those after transtympanic control solution. Conclusions: Transtympanic histamine exposure causes eustachian tube dysfunction in the rat by increasing passive opening and closing pressures of the eustachian tube and impairing mucociliary clearance time. (Otolaryngol Head Neck Surg 2001;124:414-20.)
Reducing exit stub memory consumption in code caches

The interest in translation-based virtual execution environments (VEEs) is growing with the recognition of their importance in a variety of applications. However, due to constrained memory and energy resources, developing a VEE for an embedded system presents a number of challenges. In this paper we focus on the VEE's memory overhead, and in particular, the code cache. Both code traces and exit stubs are stored in a code cache. Exit stubs keep track of the branches off a trace, and we show they consume up to 66.7% of the code cache. We present four techniques for reducing the space occupied by exit stubs, two of which assume unbounded code caches and the absence of code cache invalidations, and two without these restrictions. These techniques reduce space by 43.5% and also improve performance by 1.5%. After applying our techniques, the percentage of space consumed by exit stubs in the resulting code cache was reduced to 41.4%.
RTL Test Justification and Propagation Analysis for Modular Designs

Modular decomposition and functional abstraction are commonly employed to accommodate the growing size and complexity of modern designs. In the test domain, a divide-and-conquer type of approach is utilized, wherein test is locally generated for each module and consequently translated to global design test. We present an RTL analysis methodology that identifies the test justification and propagation bottlenecks, facilitating a judicious DFT insertion process. We introduce two mechanisms for capturing, without reasoning on the complete functional space, data and control module behavior related to test translation. A traversal algorithm that identifies the test translation bottlenecks in the design is described. The algorithm is capable of handling cyclic behavior, reconvergence and variable bit-widths in an efficient manner. We demonstrate our scheme on representative examples, unveiling its potential of accurately identifying and consequently minimizing the reported controllability and observability bottlenecks of large, modular designs.
Model Selection in Undirected Graphical Models with the Elastic Net

Structure learning in random fields has attracted considerable attention due to its difficulty and importance in areas such as remote sensing, computational biology, natural language processing, protein networks, and social network analysis. We consider the problem of estimating the probabilistic graph structure associated with a Gaussian Markov Random Field (GMRF), the Ising model and the Potts model, by extending previous work on $l_1$ regularized neighborhood estimation to include the elastic net $l_1+l_2$ penalty. Additionally, we show numerical evidence that the edge density plays a role in the graph recovery process. Finally, we introduce a novel method for augmenting neighborhood estimation by leveraging pair-wise neighborhood union estimates.
Rate of convergence for minimum power assignment algorithms in cellular radio systems

In wireless communication systems, mobile users adapt to a time varying radio channel by regulating transmitter powers. This power control is intended to provide each user an acceptable connection, as measured by a carrier to interference ratio (CIR), by eliminating unnecessary interference. It is important that a power control algorithm can converge quickly to a fixed point at which either all users have acceptable connections or an infeasibility can be detected. In this work, we show that an iterative power control and base station assignment algorithm based on CIR measurements converges to a unique fixed point at a geometric rate. This conclusion is shown to hold even if some or all of the users are subject to maximum power constraints. The rate of convergence is evaluated by simulation of a one dimensional CDMA system.
The 'relaxed invariance principle' and its applications

The author describes a novel infinite-dimensional approach to the LaSalle invariance principle. The main idea is that the method avoids the troublesome search for precompactness of orbits that often makes stability analysis of hyperbolic like initial-boundary value problems difficult. The method is quite general and would seem to be applicable to problems in feedback control of aeroelastic-like structures with weak damping. >
Point: Justification for Lynch Syndrome Screening Among All Patients With Newly Diagnosed Colorectal Cancer

Either microsatellite instability testing or immunohistochemical staining for the 4 mismatch repair proteins (MLH1, MSH2, MSH6, and PMS2) should be performed on all newly diagnosed colorectal cancers. This testing will identify tumors that are microsatellite unstable, which has implications for patient prognosis and possibly treatment. In addition, it will identify patients who are more likely to have Lynch syndrome. Of every 35 colorectal cancer patients, 1 has Lynch syndrome, the most common hereditary cause of colorectal and endometrial cancers. Diagnosis of Lynch syndrome affects the medical management of the patient and their relatives, with potentially life-saving ramifications. Although screening only a subset of patients with colorectal cancer based on age at diagnosis, family history, or histologic criteria will reduce the number of screening tests necessary, it will miss a significant proportion of patients with microsatellite unstable colorectal cancer and many patients with Lynch syndrome. Given that universal screening of all patients with newly diagnosed colorectal cancer using immunohistochemistry as the initial test was recently shown to be cost-effective and comparable with other widely accepted preventive services, it is not necessary to try to reduce costs by restricting screening to a subset of patients, which leads to a reduction in the efficacy of the screening program.
Guided waves for the health monitoring of sign support structures under varying environmental conditions

SUMMARY Guided ultrasonic waves are increasingly used in all those structural health monitoring applications that benefit from built-in transduction, moderately large inspection ranges, and high sensitivity to small flaws. The wave-based structural health monitoring of complex or thick structures can be difficult because of factors such as simultaneous propagation of many modes, large number of overlapping reflections, and mode conversion. Moreover, if the structures are subjected to environmental changes, variations on the characteristics of the detected signals are observed. This paper describes a health monitoring system for large trusses that combines the advantages of guided ultrasonic waves with the extraction of defect-sensitive features aimed at performing a multivariate diagnosis of damage. The system was tested on a chord of a dismantled overhead sign support structure subjected to changing environmental conditions. Cold/warm temperatures and wet/snow boundary conditions were created. The system's hardware consisted of a data acquisition unit that controlled the generation and detection of ultrasonic signals by means of an array of piezoelectric transducers. The signals were processed using a feature-based approach whereby features between two signals collected simultaneously or between a signal and a baseline were compared. The features were then fed into an unsupervised learning algorithm based on outlier analysis. Experimental results show that damage can be detected even in the presence of temperature and boundary condition variations. Copyright © 2011 John Wiley & Sons, Ltd.
Carbon, Nitrogen and Oxygen Stable Isotope Ratios in Chitin

Stable isotope ratios in chitin are firmly imprinted during biopolymer biosynthesis and reflect dietary, metabolic, and environmental influences. Chitin is a chemically complex amino sugar biopolymer that also includes non-amino-sugar moieties with contrasting isotopic compositions. Reproducible N, C, O-stable isotope determinations should rely on a chemically purified chitin substrate with limited non-amino-sugar contributions. Insecta, Crustacea and Merostomata are not distinguished by systematic isotopic differences. δ13C, δ15N and δ18O values of arthropod chitins show a few ‰ variance within a single individual (lobster), among individuals within a population, along ecdysis (i.e., molting), and age, as long as growth is not accompanied by strong dietary or behavioral changes. Marine arthropod chitin averages 9.1‰ more 13C-enriched than terrestrial chitin. δ15N values of chitin become more positive with increasing trophic level. Although δ18Ochitin from a large array of aquatic crustacean species across many ecosystems expresses only weak overall correlation with δ18Owater and no clear dependence on temperature, a more careful selection of specific modern insect fauna or preserved insect chitin from sediments yields δ18Ochitin values that are useful for reconstructing the isotopic composition of paleoenvironmental water, and for constraining paleohumidity and paleotemperatures. Experimental oxic and anoxic heating and partial biodegradation of chitin in marine anoxic mud and in terrestrial oxic soils did not result in any significant C, N, O-isotopic shifts in the preserved amino sugar. Chemically preserved archeological chitin was found to be isotopically compatible with modern chitin from comparable environments. New analytical stable isotope techniques with reduced sample size requirements open opportunities to utilize geologically preserved chitin in paleoenvironmental studies.
Rescue of tropomyosin deficiency in Drosophila and human cancer cells by synaptopodin reveals a role of tropomyosin α in RhoA stabilization

Tropomyosins are widespread actin-binding proteins that influence numerous cellular functions including actin dynamics, cell migration, tumour suppression, and Drosophila oocyte development. Synaptopodin is another actin-binding protein with a more restricted expression pattern in highly dynamic cell compartments such as kidney podocyte foot processes, where it promotes RhoA signalling by blocking the Smurf1-mediated ubiquitination of RhoA. Here, we show that synaptopodin has a shorter half-life but shares functional properties with the highly stable tropomyosin. Transgenic expression of synaptopodin restores oskar mRNA localization in Drosophila oocytes mutant for TmII, thereby rescuing germline differentiation and fertility. Synaptopodin restores stress fibres in tropomyosin-deficient human MDA-MB 231 breast cancer cells and TPMα-depleted fibroblasts. Gene silencing of TPMα but not TPMβ causes loss of stress fibres by promoting Smurf1-mediated ubiquitination and proteasomal degradation of RhoA. Functionally, overexpression of synaptopodin or RhoA(K6,7R) significantly reduces MDA-MB 231 cell migration. Our findings elucidate RhoA stabilization by structurally unrelated actin-binding proteins as a conserved mechanism for regulation of stress fibre dynamics and cell motility in a cell type-specific fashion.
Ketosis in infants and children.

Summary The biochemical reactions related to the formation of ketone bodies have been reviewed. An attempt has been made to indicate the metabolic interrelationship of fats, carbohydrates, and hormones. Although there has been notable progress in the field of fat metabolism in the last 10 years, there remain many unanswered questions. In relation to ketosis the fundamental question is the mechanism of regulation of acetoacetate synthesis. The following are some of the factorswhich need to be considered when studying the mechanisms involved in the accumulation of ketone bodies: 1. The mobilization of fatty acids. a. Agents which stimulate fatty acid mobilization and those which inhibit fatty acid release. b. Metabolism of adipose tissue andthe relation to the surrounding medium. 2. Fatty acid oxidation. a. Relation of phosphorylation tooxidation by mitochondria in the presence of an increased concentration of fatty acids. b. The rate limiting step of oxidation in the Krebs cycle. c. The role of reduced nucleotides. d. The role of glucose utilization and gluconeogenesis. e. Nature and effect of metaboliteswhich regulate the pathway to acetoacetate specifically. 3. Peripheral utilization. Several clinical conditions associated withketosis are briefly surveyed, and it is found that the factors noted above vary in degree and in different situations. Attention is directed to the resistance of small infants to ketosis, and the possible mechanisms involved are discussed.
Using Case Studies to Characterize the Broader Meaning of Engineering Design for Today's Student

Numerous organizations have undertaken the task of envisioning the education required to meet the engineering demands of the future. The ABET study EC2000, ASCE’s Civil Engineering Body of Knowledge and Body of Knowledge 2 and the National Academy of Engineering have documented the need to change engineering education from its historical focus on technical content knowledge to include greater emphasis on professional issues and to integrate engineering practice into education. To this end teaching methods such as project-based learning, and the use of case studies are being explored to address these broader learning outcomes. Case studies in particular facilitate telling the stories of professional practice. This paper discusses the use of engineering case studies in design coursework with specific application to third year architectural engineering student learning. Introduction, application and discussion of several case studies are presented in the context of teaching building structural design. Along with the technical execution of system and member selection, computer analyzes and structural detailing that occur in these courses, broader concepts relating to professional roles and responsibilities, design team interplay, the design process, the construction process and professional practice ethics are investigated. The advantages of this altered approach to teaching engineering design are discussed.
Efficacy of ECT for Agitation in Dementia: A Case Report

A patient with vascular dementia had severe, unremitting agitation that was refractory to conventional therapies and put her life in jeopardy. She had a dramatic response to bilateral electroconvulsive therapy (ECT), with longitudinal follow-up demonstrating that her behavioral symptoms lapsed predictably when maintenance ECT was delayed.
On the intergranular hydrogen embrittlement mechanism of Al-Li alloys

An investigation is conducted of the stress-assisted grain-boundary diffusion of hydrogen in Al-Li alloys, with a view to the characterization of the intergranular embrittlement mechanism. A comparison of theoretical predictions with experimental observations indicates that intergranular hydrogen embrittlement involves the nucleation of an incremental crack at the edge of the plastic zone that extends not only backwards, to join the original crack, but also forwards: in a region that is stressed above a critical level and has a rather elevated hydrogen concentration. Crack jump distance predictions are in excellent agreement with experimental observations; ligament fracture is the step controlling the hydrogen-embrittlement fracture process. 17 refs.
Eight New Carbon Chain Molecules

A summary is given of the laboratory measurements of the rotational spectra of eight new carbon chains: the cyanopolyynes HC11N and HC13N; the carbon chain radicals C7H, C8H, C9H, and C11H; and the cumulene carbenes H2C5 and H2C6. Measured line frequencies and derived spectroscopic constants are listed for all eight, and rest frequencies for the astronomically important transitions that are not easily calculated are tabulated. With our laboratory measurements, four of the new carbon chains have already been detected in at least one astronomical source; the remaining four should be detectable with existing large centimeter- or millimeter-wave telescopes.
The training of knowledge structures for manufacturing tasks: an empirical study

Abstract Knowledge structure refers to the manner in which a human organizes knowledge with a given domain. Research has identified knowledge structure as a determinant of the human ability to perform cognitive-oriented tasks. Yet uncertainty still exists about how to improve an individual's cognitive task performance through the controlled utilization of the individual's knowledge structure. The purpose of this study is to investigate whether the development of individual's knowledge structure in a particular domain can be manipulated through training. The experiment utilized the manufacturing domain of plastic extrusion machine operation. Sixteen subjects, having no previous knowledge of the domain, were randomly assigned to one of two experimental groups. Each of the experimental groups corresponded to a distinct training condition. Over a three-day period, both training groups received the same instructional content; however, the sequence in which the training material was presented differed. One grou...
Measurements of ultrafast scintillation rise times: evidence of energy transfer mechanisms

Abstract The physical processes associated with scintillation growth and decay are investigated using ultrafast measurements of luminescence following pulsed X-ray excitation. Rise times with a time resolution of ∼30 ps have been measured for several intrinsic and activated crystalline and amorphous materials at room temperature. Rise times of excitonic emission from CsI, CaF2, Y2SiO5, Y3Al5O12, Bi4Ge3O12, CeF3,and fused silica were less than our system response time, thus demonstrating very fast ( 10 ns indicating excitation by prompt capture of electrons at the activator site followed by the known slower migration and capture of holes (Vk centers). Measurements of core-valence luminescence from BaF2 and intraband luminescence from CsI are also reported.
Effect of Rotation on Heat Transfer in Narrow Rectangular Cooling Channels (AR = 8:1 and 4:1) With Pin-Fins

The effect of rotation on smooth narrow rectangular channels and narrow rectangular channels with pin-fins is investigated in this study. Pin-fins are commonly used in the narrow sections within the trailing edge of the turbine blade; the pin-fins act as turbulators to enhance internal cooling while providing structural support in this narrow section of the blade. The rectangular channel is oriented at 150° with respect to the plane of rotation, and the focus of the study involves narrow channels with aspect ratios of 4:1 and 8:1. The enhancement due to both conducting (copper) pin-fins and non-conducting (plexi-glass) pins is investigated. Due to the varying aspect ratio of the channel, the height-to-diameter ratio (hp /Dp ) of the pins varies from two, for an aspect ratio of 4:1, to unity, for an aspect ratio of 8:1. A staggered array of pins with uniform streamwise and spanwise spacing (xp /Dp = sp /Dp = 2.0) is studied. With this array, 42 pin-fins are used, giving a projected surface density of 3.5 pins/in2 (0.543 pins/cm2 ), for the leading or trailing surfaces. The range of flow parameters include Reynolds number (ReDh = 5000–20000), rotation number (Ro = 0.0–0.302), and inlet coolant-to-wall density ratio (Δρ/ρ = 0.12). Heat transfer in a stationary pin-fin channel can be enhanced up to 3.8 times that of a smooth channel. Rotation enhances the heat transferred from the pin-fin channels 1.5 times that of the stationary pin-fin channels. Overall, rotation enhances the heat transfer from all surfaces in both the smooth and pin-fin channels. Finally, as the rotation number increases, spanwise variation increases in all channels.Copyright © 2003 by ASME
Perceptions of Influence Relationships and Faculty Satisfaction: A Study in Organizational Control:

This study compared hierarchical influence patterns for faculty chairmen and the College Dean to faculty morale. Ex-faculty members reported their perceptions of influence they had with the chairmen and their chairman's influence with the Dean. The distribution of control for these organizational levels was believed to be related to the positive feelings faculty had for the institution.
Compression failure characteristics of + or - 45-deg-dominated laminates with a circular hole or impact damage

An investigation of the compression failure characteristics of + or - 45-deg-dominated laminates with a circular hole or impact damage was conducted. Graphite-epoxy laminates consisting of all + or - 45-deg plies and of + or - 45-deg and 90-deg plies were evaluated. Inplane shearing between the fibers and matrix (i.e., matrix shearing) was found to be the primary compression failure mechanism for an all + or - 45-deg laminate with a hole. The failure mechanism for the + or 45-deg-dominated laminates with a hole appeared to be a combination of delamination and matrix shearing. The compression failure stresses and strains for both the all + or - 45-deg laminate and the + or - 45-deg-dominated laminates were unaffected by impact damage at an energy level of 5.5 J when compared to results for undamaged control specimens. The failure stresses and strains for all laminates with impact damage at an energy level of 17.0 J or of 34.3 J were significantly lower than the corresponding data for the undamaged control specimens. The failure stresses and strains for these impact-damaged specimens were independent of the percentage of 90-deg plies in the laminate.
Nano-scaled SRAM thermal stability analysis using hierarchical compact thermal models

Non-uniform temperature profile generated by hot- spots affect the nearby units in a chip. Different sections of a large sized cache memory would experience different failure statistics due to their proximity to the hot-spots. The nano-scaled SRAM (Static Random Access Memory) cell stability is analyzed systematically under such 'spatial' temperature variations for different technologies. The bitcell level compact thermal models are generated for 65 nm, 45 nm, 32 nm and 22 nm bulk CMOS technology nodes based on the 6 T 'thin-cell' structure. Next, the block level and system level 'macro' thermal models are generated hierarchically for each technology node. A prominent effect 'leakage induced stability degradation' is observed at 22 nm node. This work demonstrates that leakage reduction techniques should consider temperature/stability aspects in nano-scaled SRAM cells.
Design Issues Associated with Discrete and Distributed Hypermedia GIS

The advancement of computer technology enables the integration of geographic information system (GIS) and multimedia technologies that allow to incorporate not only spatial-temporal geographic information in image/vector format, but also multimedia geographic information in descriptive text, scanned ground photographs, graphics, digital video and sound. The concept of hypermedia GIS is defined in this chapter. Design issues on the development of hypermedia GIS for use on individual personal computers (PC) (i.e., discrete system) and on the Internet (i.e., distributed system) are discussed. Software requirement, file format and data structure used in each system are described. The discrete and distributed hypermedia GIS provide the essential concepts and techniques for many new GIS applications such as visualization, spatial decision support systems and spatial database management and exploration.
Photoluminescence properties of ZnS epilayers grown by metalorganic molecular beam epitaxy

A comprehensive study is reported of the epitaxial growth and photoluminescence properties of ZnS on GaAs and Si. Conventional and photoassisted MOMBE and CBE growth using H 2 S, DipS and t-BuSH, with DeZn showed higher growth rates in the presence of H, or under photoassisted conditions. At low temperatures, the radical alkyl by-products from the cracked precursors were identified as reducing the growth rate through surface site blocking. A CaF 2 buffer layer was shown to improve the crystalline quality due to elimination of a reaction between S and Si. Low temperature photoluminescence studies identified recombinations from the ground and the first excited states of the free exciton as well as from neutral donor and acceptor bound excitons, and phonon replicas.
Band-selective hetero- and homonuclear cross-polarization using trains of shaped pulses

The performance of solution cross-polarization using trains of shaped pulses on two channels is investigated by computer simulation and experiment. It is determined that a Waltz modulation pattern of Gaussian pulses of individual flip angles of 225°, issued to two coupled spins simulatneously, yields excellent coherence transfer with good phasing behavior. Simulations and experimental verification were carried out for both heteronuclear cross-polarization between two restricted areas (e.g. 1Hα−13Cα) and for homonuclear cross-polarization between two spectral regions (e.g. 13CO−13Cα). It is shown that shaped cross-polarization behaves as pure heteronuclear cross-polarization when the two radiofrequency (rf) fields are far apart, while it behaves in some aspects analogous to homonuclear cross-polarization when the two rf fields approach each other. The novel coherence-transfer sequence, referred to as ‘cosine-modulated shaped Waltz’ (CSW), was implemented in a 3D (H)C(CCO)NH experiment using an 18-kDa isotopically labeled protein.
The politics of post-war demobilization and reintegration in Nigeria

In October 1999, Oha-na-Eze Ndi Igbo, the self-styled ‘apex organization of the entire Igbo people of Nigeria’ filed a petition before the Nigerian Human Rights Violations Investigation Commission ...
Mapping the origin of the avian enteric nervous system with a retroviral marker.

The enteric nervous system is largely formed from the vagal neural crest which arises from the neuroaxis between somites 1-7. In order to evaluate the contribution of different regions of the vagal crest to the enteric nervous system, we marked crest cells by injecting somites 1-10 with a replication-defective spleen necrosis virus vector which contains the marker gene ZucZ. After incubation in X-gal, ZucZ-positive blue cells were found in the wall of the gut in three locations. Most were found at the peripheral edge of the developing circular muscle and within the developing submucosa, sites characteristic of developing ganglia. LacZ-positive cells in these ganglionic sites were always surrounded by HNK- 1 immunostained cells, confirming their neural crest origin. LucZ-positive cells were also seen in a third location, the circular muscle layer of the esophagus and crop, and were separated from the HNK-1 positive ganglionic elements. These cells in the circular muscle are probably muscle cells derived from labeled mesodermal cells of the somite. Injection of somites 3, 4, 5, and 6 resulted in the largest percentage of preparations with ZucZ-positive crest-derived cells and in the largest number of positive cells in the gut. After injection of these somites, ZacZ- positive crest-derived cells were found in all regions of the gut from the proventriculus to the rectum. Very few positive crest-derived cells were found in the esophagus. Injection of somites 1, 2, and 7 resulted in a smaller percentage of prepa- rations with positive crest-derived cells and in a smaller number of positive crest-derived cells, which were confined to the fore and midgut. The gizzard was the gut region most frequently containing labeled cells and the rectum was the region least frequently containing such cells. This suggests that the number of crest cells available for colonization of the gut decreases as the distance from the gizzard increases. We conclude that the region of the neuroaxis be- tween somites 3-6 is the major source of crest cells to the gut and that crest cells from different segments of the neuroaxis do not appear to be segregated to different regions of the gut.
Hydrostatic pressure-regulated ion transport in bladder uroepithelium

The effect of hydrostatic pressure on ion transport in the bladder uroepithelium was investigated. Isolated rabbit uroepithelium was mounted in modified Ussing chambers and mechanically stimulated ...
Racial Wage Differences among Young Male Job Changers: The Relative Contribution of Migration, Occupation Change, Site Characteristics, and Human Capital

We demonstrated racial differences in the relationship between migration, location, and predicted wages for young male workers who have changed employers. An Oaxaca decomposition allowed a measuring of the contributions of migration, occupation change, site features, and human capital to the racial wage gap. Migration decreases black–white wage differences, and wage compensation for site attributes favors white householders. Constraints on occupation choice and migration dampen the ability of blacks to improve wages. Because most job changes occur in the first ten years of a career, these results on young workers give important general insights into the origins and persistence of racial wage gaps.
Nanodevices: a bottom-up view

Top-down vs. bottom-up: It is common to differentiate between two ways of building a nanodevice: a top-down approach starting from something big and chisel out what is needed and a bottom-up approach starting from something small like atoms or molecules and assemble what is needed
Relic interstellar grains in Murchison meteorite

Isotopic analyses of hydrogen, carbon and nitrogen in meteorites provide important information about the origin and history of these elements both in meteorites and in the Solar System. Here we show that, in the Murchison meteorite, the D/H ratios of hydrogen are unusually high in several separates and in one case up to 30 times the cosmic value of 2 × 10^(−5). Many phases show high ^(13)C/^(12)C ratios, up to 2.5 times the terrestrial value of 0.011. These ^(13)C-rich and D-rich components of the two chemical elements are not correlated. Also they are heterogeneously distributed, suggesting that different components in the meteorite originated from different astrophysical sites and at different times. The D-rich hydrogen in the meteorite is probably due to molecules formed by ion–molecule reactions in interstellar clouds while the tiny amount of ^(13)C-rich carbon is probably due to nucleosynthesis in red giant stars as suggested by Swart et al. Both of these heavy-isotope enriched components survived homogenization in the accumulation and subsequent history of the meteorites.
Requirement of the CXXC motif of novel Francisella infectivity potentiator protein B FipB, and FipA in virulence of F. tularensis subsp. tularensis

The lipoprotein encoded by the Francisella tularensis subsp. tularensis locus FTT1103 is essential for virulence; an FTT1103 deletion mutant is defective in uptake and intracellular survival, and mice survive high dose challenges of greater than 10(8) bacteria. This protein has two conserved domains; one is found in a class of virulence proteins called macrophage infectivity potentiator (Mip) proteins, and the other in oxidoreductase Disulfide Bond formation protein A (DsbA)-related proteins. We have designated the protein encoded by FTT1103 as FipB for Francisellainfectivity potentiator protein B. The locus FTT1102 (fipA), which is upstream of fipB, also has similarity to same conserved Mip domain. Deletion and site-specific mutants of fipA and fipB were constructed in the Schu S4 strain, and characterized with respect to intracellular replication and in vivo virulence. A nonpolar fipA mutant demonstrated reduced survival in host cells, but was only slightly attenuated in vivo. Although FipB protein was present in a fipA mutant, the abundance of the three isoforms of FipB was altered, suggesting that FipA has a role in post-translational modification of FipB. Similar to many DsbA homologues, FipB contains a cysteine-any amino acid-any amino acid-cysteine (CXXC) motif. This motif was found to be important for FipB's role in virulence; a deletion mutant complemented with a gene encoding a FipB protein in which the first cysteine was changed to an alanine residue (AXXC) failed to restore intracellular survival or in vivo virulence. Complementation with a gene that encoded a CXXA containing FipB protein was significantly defective in intracellular growth; however, only slightly attenuated in vivo.
Structural connectivity analysis reveals abnormal brain connections in agenesis of the corpus callosum in children

Objectives Structural connectivity analysis is an ideal tool to study connections in brain malformations. We aimed to characterize the topological network measures and study sub-networks in children with agenesis of the corpus callosum (AgCC). We hypothesized a more segregated structural network in children with AgCC.
Learning a prior on regulatory potential from eQTL data.

Genome-wide RNA expression data provide a detailed view of an organism's biological state; hence, a dataset measuring expression variation between genetically diverse individuals (eQTL data) may provide important insights into the genetics of complex traits. However, with data from a relatively small number of individuals, it is difficult to distinguish true causal polymorphisms from the large number of possibilities. The problem is particularly challenging in populations with significant linkage disequilibrium, where traits are often linked to large chromosomal regions containing many genes. Here, we present a novel method, Lirnet, that automatically learns a regulatory potential for each sequence polymorphism, estimating how likely it is to have a significant effect on gene expression. This regulatory potential is defined in terms of “regulatory features”—including the function of the gene and the conservation, type, and position of genetic polymorphisms—that are available for any organism. The extent to which the different features influence the regulatory potential is learned automatically, making Lirnet readily applicable to different datasets, organisms, and feature sets. We apply Lirnet both to the human HapMap eQTL dataset and to a yeast eQTL dataset and provide statistical and biological results demonstrating that Lirnet produces significantly better regulatory programs than other recent approaches. We demonstrate in the yeast data that Lirnet can correctly suggest a specific causal sequence variation within a large, linked chromosomal region. In one example, Lirnet uncovered a novel, experimentally validated connection between Puf3—a sequence-specific RNA binding protein—and P-bodies—cytoplasmic structures that regulate translation and RNA stability—as well as the particular causative polymorphism, a SNP in Mkt1, that induces the variation in the pathway.
Development, operation, and testing of a heuristic line balancing program for a microcomputer

Abstract This paper discusses the development, operation, and testing of a heuristic line balancing program that solves the Type I Line Balance problem using a microcomputer. The line balancing method selected was based on previous studies that compared different line balancing techniques. The model is built primarily using the Hoffman (1963) procedure with modifications described by Gehrlein and Patterson (1975). For purposes of comparison the Rank Positional Weight technique (Helgeson and Birnie, 1961) is also included in the model. Testing included thirty-seven different balances using problems from the literature. For each balance both Rank Positional Weight and Hoffmann solutions were obtained in the forward and reverse directions. Delay factors used for the Hoffmann balances were 0.0, 0.5, 1.0, 1.25, 1.5, and 2.0. Thus for each balance problem a total of fourteen tests were conducted. The total number of tests was 518. Four measures of performance were considered in this study. These measures of performance were: (1) the average percent a balance is above the optimum solution, in terms of number of stations; (2) time to obtain a balance; (3) the best solution in terms of the lowest number of stations and lowest standard deviation of the slack times, and (4) the largest value of minimum station slack time. Overall it was found that the Modified Hoffmann procedure with a delay factor of 1.5 performed best. The time to obtain a balance using the Modified Hoffmann procedure is significantly less than the time for a solution without the modifications.
Correction for contaminant fluorescence in frequency-domain fluorometry☆

We describe a general method to correct for contaminant fluorescence when using the technique of frequency-domain fluorometry. The method can be applied regardless of the origin of the background signal, from scattered light, impurity fluorescence, or both. The procedure requires measurement of the frequency-dependent phase and modulation of the background at enough frequencies to approximate the decay law of the background. We also describe a general method to propagate the uncertainties in the measured phase and modulation values into the corrected values. This propagation is necessary to ensure proper weighting of the frequency-dependent data in the least-squares fitting algorithms. The practical usefulness of this correction method is demonstrated using frequency-domain data for one and two component mixtures which were deliberately contaminated with scattered light and/or other fluorophores.
The role of gallbladder emptying in gallstone formation during diet-induced rapid weight loss

Obese persons are at risk for cholesterol gallstones because their bile is saturated with cholesterol. The risk increases during rapid weight loss by means of certain very-low-calorie diets or gastric bypass surgery. Gallstone risk factors during rapid weight loss include increased bile cholesterol saturation index and gallbladder stasis. Obese subjects were randomized to one of two low-calorie liquid diets for rapid weight loss: a 520-kcal diet with less than 2 g fat/d, and a 900-kcal diet with 30 g fat/d (including one 10-g fat meal to stimulate maximal gallbladder emptying). Bile and blood lipids, saturation index, leukocyte 3-hydroxy-3-methylglutaryl coenzyme A (HMG CoA) reductase activity, and ultrasonographic gallbladder emptying were measured repeatedly during dietary treatment. Both diets produced comparable weight loss of 22%. Bile cholesterol saturation index increased during both diets (26%), but fell to 15% below prediet level after weight loss. Compared with subjects' maximal gallbladder emptying fraction of 66%, the 520-kcal diet provided poor gallbladder emptying (35%), whereas the 10-g fat meal of the 900-kcal diet provided maximal emptying. Gallstones developed in four of six 520-kcal subjects and none of seven 900-kcal subjects (P = .021), an unanticipated difference that resulted in premature study termination for ethical reasons. Blood lipids and HMG CoA reductase activity in mononuclear leukocytes fell at week 8 during both diets, but recovered while weight was still being lost. The findings suggest that gallstone risk during rapid weight loss may be reduced by maintenance of gallbladder emptying with a small amount of dietary fat. Ultimately, weight loss reduced bile cholesterol saturation and improved highdensity lipoprotein (HDL) levels.
Identification of differential melanocortin 4 receptor agonist profiles at natively expressed receptors in rat cortical astrocytes and recombinantly expressed receptors in human embryonic kidney cells.

Using cAMP accumulation as a functional readout, we pharmacologically characterized the response of native melanocortin receptors in cultured rat astrocytes, and found this response to be mediated by the melanocortin 4 receptor (MC4R). Melancortin agonists stimulate cAMP in a concentration-dependent manner in both astrocytes and human embryonic kidney cells recombinantly expressing rat MC4R (HEK-rMC4R), however, the relative potency and intrinsic activity of both small molecule and peptide agonists are reduced in the native system. As such, the small molecules THIQ, NBI-702 and MB243 display 43, 30 and 18% of the maximal response elicited by α-MSH in astrocytes. Likewise, the peptides MTII and ACTH display 55 and 72% of the maximal response elicited by α-MSH in these cells. In contrast, all of these compounds elicit full agonist responses with similar intrinsic activity to α-MSH in HEK-rMC4R cells. MC4R mRNA was detected in astrocytes, however radioligand binding experiments failed to detect measurable MC4R in astrocyte membranes, in contrast to membranes from HEK-rMC4R cells that display a binding site density of 18.1 ± 1.5 fmol/mg. We propose that the divergent observations in functional activity between the cell types reflect differences in receptor expression and that caution should be exercised when interpreting agonist activity in over-expression systems for the purposes of drug discovery.
Endoscopic mucosal resection for early esophageal cancer

In the United States and Europe, the focus of endoscopic treatment for esophageal cancer has been the palliative management of advanced cancers. In Japan, where cancers of the esophagus and stomach have a high prevalence, the focus has been the early detection of esophageal cancer and the development of endoscopic modalities to curatively treat cancer. Advances in the endoscopic and endosonographic diagnosis of early esophageal cancer have paralleled the development of endoscopic resectional techniques, collectively referred to as endoscopic mucosal resection (EMR). EMR has achieved a high level of sophistication in Japan, where endoscopists use double-lumen endoscopes, specia overtubes, and innovative accessories to achieve complete and safe excision of early esophageal cancer. In appropriately selected patients, EMR offers an attractive alternative to conventional surgical management. Interest for EMR techniques is growing in the United States and Europe as a result of increased awareness of early cancer and the potential for cure endoscopically.
NGF PROTECTS PC12 CELLS AGAINST ISCHEMIA BY A MECHANISM THAT REQUIRES THE N-KINASE

Nerve growth factor (NGF), which has been shown to act as a morphological and neurochemical differentiating factor in PC12 cells, also protects PC12 cells from the toxicity of serum withdrawal and ischemia. By using a previously established in vitro model of ischemia, which incorporates the combination of anoxia with glucose deprivation (Boniece and Wagner: J Neurosci 13:4220–4228, 1993), we have been able to study the signal transduction pathways upon which NGF-induced survival is dependent. Here we demonstrate that inhibitors of the N-kinase and NGF-induced neuritogenesis, 6-thioguanine and 2-aminopurine, prevent the protective effects of NGF, while they have little, if any, effect on the protection conferred by epidermal growth factor (EGF) or dbcAMP. This suggests that only NGF acts by a mechanism that depends strongly on the N-kinase. Furthermore, the methyltransferase inhibitor 5′-deoxy-5′-methylthioadenosine (MTA), which also inhibits NGF-induced neuritogenesis, inhibits the protective effect of NGF but not the protective effects of EGF or dbcAMP. Thus, the neuroprotective effect of NGF requires some of the same signal transduction steps used by NGF to promote differentiation and neurite formation. Furthermore, we found that exposure of PC12 cells to retinoic acid, which promotes the differentiation and inhibits the growth of PC12 cells, also improves cell survival during ischemia. In addition, a combination of NGF and retinoic acid was more effective than either agent alone. It is likely that these two agents confer protection by independent pathways. © 1995 Wiley-Liss, Inc.
Structure and Dynamics of Water in the Presence of Charged Surfactant Monolayers at the Water−CCl4 Interface. A Molecular Dynamics Study

We have performed molecular dynamics simulations of sodium dodecyl sulfate (SDS) and a model cation at the water−CCl4 interface at a coverage of 45 A2/molecule. In order to isolate the effects due to the polarity of the surfactant, the model potential for the cationic surfactant is chosen to be identical to that of SDS except that the sign of all atomic charges, including counterions, are reversed. We show that the structural features of the two types of surfactant monolayers give rise to large differences in the surface potential profiles and in the overall potential difference across the water−surfactant−CCl4 interface. In addition, we show that water in intimate contact with the ionic layer is significantly altered in terms of its dynamical propertiesa decrease of up to 1 order of magnitude in the rotational correlation time for the water dipole reorientation is observed. We also show that water orientational polarization propagates well into the bulk region and that this polarization depends on the si...
Internet use by parents of infants with positive newborn screens

Background Internet searches on health topics are common, but not enough is known about online use during serious health concerns. The aim of this study was to investigate parents’ internet use and responses to online information following the referral of their newborn screen-positive infants.
RESONANCES IN NEAR-THRESHOLD X-RAY PHOTOABSORPTION OF INNER SHELLS

Synchrotron radiation measurements of near-threshold and broad-range (20 eV - 3 keV) absolute photoabsorption cross sections were made at the Brookhaven National Laboratory (NSLS) and at Stanford (SSRL). Transmission data for well-characterized multilayer foils provided absolute cross sections with 10% overall uncertainties and better than 0.2% energy resolution. Several examples of our results are presented.