cssi/SciSciGPT-SciSciNet huggingface dataset:
The Law and Economics of Family Unification

The US is internationally unique in the percentage of immigrant visas reserved for family members. The practice has been criticized on the grounds that visas for parents, siblings, and adult children might better be reallocated to skilled workers, and Congress has come close to adopting such reforms. This Article argues by contrast that family unification is a very good economic deal for the US. First, the limited data that exist, contrasting immigrant earnings by type of visa, show no sharp distinction in earnings by type of immigrant visa. This is a surprise to one operating entirely within a human capital framework in which all earnings in labor markets are necessarily a function of skills and education. The paradox is resolved by incorporating three economic models of migration or labor markets that are not usually applied to this debate: (1) New Economics of Migration or family investment models, in which families, not individuals, are economic units; (2) network models of labor markets, in which productivity reflects social ties rather than skills as such; and (3) family economics in which a woman’s economic contribution is often reflected in the earnings of her husband, children, or a family firm. Incorporating these models makes sense of three frequently-observed patterns of immigrant economic activity that illustrate why family unification visas are a good economic deal. Immigrant women frequently perform paid or unpaid intrafamily child care. Immigrants frequently work in family businesses. Immigrant wives frequently work while husbands build small businesses or attend graduate school. In each of these common scenarios, the immigrant admitted on a family unification visa is economically productive and almost certain not to be taking a job from a US worker. However, the immigrant’s economic contribution is importantly realized by the immigrant’s children, spouse, or family business. While skilled migration is crucial to US economic success, there is no reason that it should come at the expense of family unification.
Spectrally resolved gain dynamics of a semiconductor optical amplifier for the amplification of multiwavelength pulses

The spectrally resolved gain dynamics of a semiconductor optical amplifier is measured under the amplification of multiwavelength pulses. Nonlinear effects are observed and demonstrated to be avoided by the inherent chirp of semiconductor mode-locked lasers.
Evolutionary Analysis of the B56 Gene Family of PP2A Regulatory Subunits

Protein phosphatase 2A (PP2A) is an abundant serine/threonine phosphatase that functions as a tumor suppressor in numerous cell-cell signaling pathways, including Wnt, myc, and ras. The B56 subunit of PP2A regulates its activity, and is encoded by five genes in humans. B56 proteins share a central core domain, but have divergent amino- and carboxy-termini, which are thought to provide isoform specificity. We performed phylogenetic analyses to better understand the evolution of the B56 gene family. We found that B56 was present as a single gene in eukaryotes prior to the divergence of animals, fungi, protists, and plants, and that B56 gene duplication prior to the divergence of protostomes and deuterostomes led to the origin of two B56 subfamilies, B56αβe and B56γδ. Further duplications led to three B56αβe genes and two B56γδ in vertebrates. Several nonvertebrate B56 gene names are based on distinct vertebrate isoform names, and would best be renamed. B56 subfamily genes lack significant divergence within primitive chordates, but each became distinct in complex vertebrates. Two vertebrate lineages have undergone B56 gene loss, Xenopus and Aves. In Xenopus, B56δ function may be compensated for by an alternatively spliced transcript, B56δ/γ, encoding a B56δ-like amino-terminal region and a B56γ core.
Young Children‘s Mathematics References During Free Play in Family Child Care Settings

Very little is known about children's discussion of mathematics topics during unstructured play. Ginsburg, Lin, Ness, and Seo [2003. Young American and Chinese children's everyday mathematical activity. Mathematical Thinking and Learning, 5(4), 235–258. Retrieved from http://web.ebscohost.com/ehost/detail?sid=e2cc384a-0a86-471d-8c61-e61493d18ee6%40sessionmgr114&vid=1&hid=111&bdata=JnNpdGU9ZWhvc3QtbGl2ZQ%3d%3d#db=mth&AN=10800300] have examined children's mathematics conversations in centre-based childcare, but to our knowledge no one has looked at children's mathematics conversations in home-based family childcare. On the other hand, it is often through children's spontaneous play themes that we have an indication of what is on a child's mind. This study examined the mathematics talk of children during unstructured play in non-parental, family childcare environments. Audio tapes of 50 children (20 girls) ranging in age from 3 to 5 years were transcribed and coded for different types of mathematical referen...
Genomic clones of bovine parvovirus: construction and effect of deletions and terminal sequence inversions on infectivity.

Abstract Genomic clones of the autonomous parvovirus bovine parvovirus (BPV) were constructed by blunt-end ligation of reannealed virion plus and minus DNA strands into the plasmid pUC8. These clones were stable during propagation in Escherichia coli JM107. All clones tested were found to be infectious by the criteria of plaque titer and progressive cytopathic effect after transfection into bovine fetal lung cells. Sequencing of the recombinant plasmids demonstrated that all of the BPV inserts had left-end (3')-terminal deletions of up to 34 bases. DNA isolated from progeny virions arising from transfected infectious clones was found to be indistinguishable from wild-type DNA by restriction enzyme analysis. Defective genomes could also be detected in the progeny DNA even though the infection was initiated with homogenous, cloned DNA. Full-length genomic clones with 3' flip and 3' flop conformations were constructed and were found to have equal infectivity. Analysis of low-molecular-weight DNA isolated from lysates of cells transfected with these clones demonstrated that rescue and replication of BPV DNA could be detected 3 to 8 days after transfection. Expression of capsid proteins from transfected genomes was demonstrated by hemagglutination, indirect immunofluorescence, and immunoprecipitation of [35S]methionine-labeled cell lysates. Use of appropriate antiserum for immunoprecipitation showed the synthesis of BPV capsid and noncapsid proteins after transfection. Independently, a series of genomic clones with increasingly larger 3'-terminal deletions was prepared from separately subcloned 3'-terminal fragments. Transfection of these clones into bovine fetal lung cells revealed that deletions of up to 34 bases at the 3' end lowered but did not abolish infectivity, while deletions of greater than 52 bases were lethal. End-label analysis showed that the 34-base deletion was repaired to wild-type length in the progeny virus.
Feature detection algorithms in computed images

The problem of sensing a medium by several sensors and retrieving interesting features is a very general one. The basic framework is generally the same for applications from MRI, tomography, Radar SAR imaging to subsurface imaging, even though the data acquisition processes, sensing geometries and sensed properties are different. In this thesis we introduced a new perspective to the problem of remote sensing and information retrieval by studying the problem of subsurface imaging using GPR and seismic sensors. We have shown that if the sensed medium is sparse in some domain then it can be imaged using many fewer measurements than required by the standard methods. This leads to much lower data acquisition times and better images. We have used the ideas from Compressive Sensing, which show that a small number of random measurements about a signal are sufficient to completely characterize it, if the signal is sparse or compressible in some domain. Although we have applied our ideas to the subsurface imaging problem, our results are general and can be extended to other remote sensing applications. A second objective in remote sensing is information retrieval which involves searching for important features in the computed image. In this thesis we focus on detecting buried structures like pipes, and tunnels in computed GPR or seismic images. The problem of finding these structures in high clutter and noise conditions, and finding them faster than the standard shape detecting methods is analyzed. One of the most important contributions of this thesis is where the sensing and the information retrieval stages are unified in a single framework using compressive sensing. Instead of taking lots of standard measurements to compute the image of the medium and search the necessary information in the computed image, only a small number of measurements as random projections are used to infer the information without generating the image of the medium.
Knob heights within circum-Caloris geologic units on Mercury: Interpretations of the geologic history of the region

Abstract The circum-Caloris geologic units show morphology consistent with ejecta-derived formation, however crater counts suggest the units formed after the basin. To determine if the surrounding units are directly related to basin formation or products of later volcanic resurfacing events, we measured the heights and densities of knobs in 22 study regions to the east of the Caloris basin in three geologic units circumferential to the basin: the Odin Formation, the Van Eyck Formation, and the Smooth Plains Formation. In these study regions the size and concentration of ejecta blocks generally decrease away from the crater rim. The morphology that superposes the knobs and the distribution of knob heights within each study region suggests that the knobs were deposited as ejecta and later embayed by one or multiple volcanic events. The distribution of knob height and concentration indicates that the knobs within the circum-Caloris units are related to the formation of the basin.
Bank of England Reserve Policy

In his most enlightening paper on Federal Reserve policy in 1920–1921 Elmus Wicker's statement on the Bank of England's policies is not strictly in accord with the facts. The English system of no legal reserve requirements imparted a greater degree of flexibility to the monetary authorities and allowed a greater economy in the use of the gold reserve. The entire gold reserve was available in emergencies to safeguard the pound.
A compact task graph representation for real-time scheduling

A new task graph representation, namely the compact task graph (CTG), is developed to aid in the scheduling of a set of communicating periodic real-time tasks. This representation explicitly expresses the potential for parallelism across tasks as well as the idle times that may be encountered within application tasks. A CTG based scheduler can generate schedules that are able to meet deadlines by interleaving the execution of tasks on a single processor and/or overlapping the execution of tasks on multiple processors. The construction of a CTG is based upon the busy-idle execution profiles for the tasks generated by the compiler. The profiles are computed assuming that sufficient resources are available for parallel execution of all tasks. Thus, they expose all opportunities for overlapped and interleaved execution. The compiler analyzes the profiles to identify useful opportunities for interleaving and expresses them in the CTG without unnecessary partitioning of the tasks. The CTG is powerful because it expresses schedules that are not expressed by existing approaches for constructing task graphs. Schedules can be generated efficiently since a CTG's construction minimizes the splitting of tasks. We briefly demonstrate the usefulness of CTGs in scheduling real-time tasks and scheduling monitoring tasks without affecting the timing of application tasks.
Why are some children still uninsured

Introduction Nationally, 24% of low-income children remain uninsured after the implementation of the State Children's Health Insurance Program (SCHIP). Method The purpose of this study was to understand why children remain uninsured by comparing children with insurance to those without it. Using a cross-sectional survey design, 392 low-income parents were interviewed. Results There were distinct profiles for the privately insured, Medicaid-insured and uninsured groups. Statistically significant differences were found across the three groups in income, working status of the adults, education, health status of the adult and child, and in the utilization of health care. Parents of the uninsured children were less knowledgeable about the application process. Discussion Parents of uninsured children face multiple life challenges that may interfere with the enrollment process. Health problems, work schedules, and lack of knowledge may all need to be addressed before we can decrease the number of uninsured children in our nation.
A New FOXO Pathway Required for Leukemogenesis

In cancer, the FOXO family of transcription factors functions as tumor suppressors and is directly inactivated by oncogenic signaling through the PI3K/AKT pathway. Now, Skykes et al. (2011) identify a paradoxical requirement for FOXOs in the maintenance of leukemia-initiating cells.
SU-E-T-28: A Treatment Planning Comparison of Volumetric Modulated Arc Therapy Vs. Proton Therapy for Post-Mastectomy Radiotherapy

Purpose: The delivery of post-mastectomy radiotherapy (PMRT) can be challenging for patients with left-sided breast cancer due to the PTV size and proximity to critical organs. This study investigates the use of protons for PMRT in a clinically-representative cohort of patients, and quantitatively compares volumetric modulated arc therapy (VMAT) to proton therapy to have an evidence-based rationale for selecting a treatment modality for these patients. Methods: Eight left-sided PMRT patients previously treated at our clinic with VMAT were identified for the study. PTVs included the chest wall and regional lymph nodes. Passively scattered (PS) and intensity modulated proton therapy (IMPT) plans were constructed using the Eclipse proton planning system. The resulting plans were compared to the original VMAT plan on the basis of PTV coverage; dose homogeneity index (DHI) and conformity index (CI); dose to organs at risk (OAR); tumor control probability (TCP), normal tissue complication probability (NTCP) and secondary cancer complication probability (SCCP). Differences were tested for significance using the paired Student's t-test (p<0.01). Results: All modalities produced clinically acceptable PMRT plans. The comparison demonstrated proton treatment plans provide significantly lower NTCP values for the heart and the lung while maintaining significantly better CI and DHI. At a prescribedmore » dose of 50.4 Gy (RBE) in the PTV, the calculated mean NTCP value for the patients decreased from 1.3% to 0.05% for the whole heart (cardiac mortality) and from 3.8% to 1.1% for the lungs (radiation pneumonitis) for both proton therapy plans from VMAT plans. Both proton modalities showed a significantly lower SCCP for the contralateral breast compared to VMAT. Conclusion: All three plans (VMAT, PS, and IMPT) provide acceptable treatment plans for PMRT. However, proton therapy shows a significant advantage over VMAT with regards to sparing OARs and may be more advantageous for patients with unfavorable anatomy.« less
Coupled barrier island–resort model: 2. Tests and predictions along Ocean City and Assateague Island National Seashore, Maryland

[1] The fate of coastlines and their human settlements under the effects of global climate change will depend critically on the nonlinear dynamics of and feedbacks between shoreline processes and human agency. This hypothesis is explored on the barrier island coastline of Ocean City and Assateague Island National Seashore, Maryland, using a model-coupling natural coastal processes, including erosion, accretion, island overwash, alongshore sediment transport, dune growth and migration, inlet migration and ebb tidal delta growth to economics of tourist resort development through storm damage and beach and dune replenishment. Initiating the model in 1845, the RMS difference between model and measurements of the shoreline position in 2001 is 84.97 m compared to a net onshore migration of 472.2 m and the RMS difference between modeled and measured hotel room density in 2001 is 2950 rooms km−1 compared to a net gain of 28,824 rooms km−1. Simulations to year 3400 for a rate of sea level rise of 3.5 mm a−1 show a steady state barrier island position 158 m further offshore and 0.54 m lower in elevation compared to its natural counterpart. Changing the rate of sea level rise to 10.5 mm a−1 increases these differences to 288 m and 0.76 m. Changing storminess by increasing the standard deviation of storm size 50% diminishes coupling between resorts and barriers, bringing the natural and coupled attractors into near coincidence. These results suggest that predicted increases in the rate of sea level rise will lead to enhanced vulnerability for Ocean City.
Thoracic aortic stent grafting: improving results with newer generation investigational devices.

Objective Six years ago an endovascular program for repair of descending thoracic aneurysms was established at the University of Pennsylvania. We report on the hypothesis that results are improving with new stent design iterations and describe our experience and lessons learned. Methods From April 1999 to March 2005, 99 patients with descending thoracic aneurysms underwent repair with a first or second-generation commercially produced endograft; 24 patients had an early-generation device, and 75 patients had a late-generation device. Each patient was enrolled as part of 3 distinct Phase I or Phase II Food and Drug Administration-approved clinical trials in accordance with strict inclusion and exclusion criteria. Results Mean age was 73.1 years. Symptomatic aneurysms accounted for 42% of the cohort. Mean aneurysm size was 63.7 mm (range: 30-105 mm). Twenty percent of the patients underwent a subclavian carotid transposition or bypass preoperatively to obtain an adequate proximal landing zone. No procedures had to be aborted. In-hospital or 30-day mortality was 5.0%. The incidence of permanent spinal ischemia was 2%. Perioperative vascular complications requiring interposition graft, stent repair, or patch angioplasty occurred in 27% and seemed to be less frequent in the late-generation cohort than the early-generation cohort (22.7% vs 41.7%, respectively, P = .069). At the 30-day follow-up, 23 endoleaks were detected in 22 patients (14.7% in late-generation cohort vs 45.8% in early-generation cohort, P = .001). During the follow-up period, 3 new endoleaks were detected, 3 patients died of aortic rupture, and 10 patients underwent aneurysm-related reintervention. Kaplan-Meier estimated 1, 3, and 5-year survival was 84.5%, 70.5%, and 52.4%, respectively. Freedom from aneurysm-related event, defined as freedom from endoleak, aortic rupture, dissection, or any reintervention on the aorta, was 73%, 69%, and 64% at 1, 3, and 5 years, respectively. Conclusion Thoracic aortic stent grafting is a safe procedure in selected patients with the added benefit of a low incidence of paraplegia. However, there is an incidence of late complications and reinterventions. This risk requires further quantification and must be balanced against the benefits of a minimally invasive approach with low perioperative morbidity and mortality. Results are improving as technology evolves and our level of experience increases. Radiologic follow-up is mandatory.
Pulsed Laser Assisted Micromilling for Die/Mold Manufacturing

Laser assisted machining is an alternative to conventional machining of hard and/or difficult-to-process materials which involves pre-heating of a focused area with a laser beam over the surface of the workpiece to cause localized thermal softening along the path of the cutting action. The main advantage that laser assisted machining has over conventional machining is the increased material removal rate and productivity. Laser assisted micromilling is a scaled down derivative of laser assisted machining assuming that the process effectiveness potentially exists at the meso/micro scale. It is well-known that continuous-wave (c.w.) lasers generate a wide and deep heat affected zone, and can cause microstructure alterations, potentially making laser assistance counter-productive at the meso/micro scale. The novel use of a pulsed laser in assisting micromilling enables processing of die/mold metal alloys that are typically hard and/or difficult-to-process in micro scale, while reducing the heat affected zone. A fairly innovative technique is introduced by thermally softening only the focused microscale area of the work material with induced heat from a pulsed laser, and material removal is performed immediately with micro mechanical end milling. The focus of this paper is to present a fundamental understanding of the pulsed laser assisted micromilling (PLAM), in particular, to investigate the influence of pulsing on microscale localized thermal softening by coupling with the finite element simulation of the micromilling process. Experiments and Finite element method-based process simulations for micromilling of AISI 4340 steel with and without the laser assistance are conducted to study the influence of the pulsed laser thermal softening on the reduction in cutting forces and its influence on the temperature rise in the cutting tool.© 2007 ASME
Isolation of Nucleic Acids from Micrococcus lysodeikticus

WE have found a simple method for the preparation of a mixture of ribonucleic acid and deoxyribonucleic acid and the preparation of purified deoxyribonucleic acid in a highly polymerized state from cells of M. lysodeikticus. In arriving at the techniques, we have taken advantage of the fact that above pH 8.0 the activity of the ribonuclease system in M. lysodeikticus is negligible. Moreover, in the absence of orthophosphate, polynucleotide phosphorylase (polyase) is inactive toward ribonucleic acid. Therefore, for maximum yields of ribonucleic acid the lysis of the cells was carried out at pH 8.5. To destroy the ribonucleic acid selectively orthophosphate was added1. This communication presents some of the preliminary results.
Localization of Vasa mRNA during early cleavage of the snail Ilyanassa

Members of the Vasa family of helicases are specifically localized to germ line lineages in embryos of many animal groups and, in some cases, have been shown to be required for germ line formation. Despite considerable attention to the embryology of gastropod molluscs, the germ line has not been identified in the early cleavage stages of these embryos. We have cloned a Vasa ortholog in the snail Ilyanassa and examined the distribution of IoVasa mRNA during early cleavage. Initially, the transcript is present in all cells and non-specifically localized to centrosomes in a subset of cells. The IoVasa mRNA becomes progressively more enriched in the dorsal quadrant of the embryo, and then becomes restricted to particular cells in the 4d lineage. At the 64-cell stage, IoVasa mRNA is detected in 4dL11, 4dL12, 4dR11, and 4dR12. Following another round of division in the 4d lineage, the mRNA is restricted to two cells: 4dL121 and 4dR121. By the 108-cell stage, IoVasa mRNA is no longer detectable. Because the germ line is thought to arise from the 4d lineage in spiralians, these data are consistent with the hypothesis that the Ilyanassa germ line is marked by inheritance of IoVasa and derived from the cells 4dL121 and 4dR121. Alternatively, IoVasa may be required in somatic lineages where it is expressed, and the germ line may be specified later in development.
Molecular weight dependent structural regimes during the electrospinning of PVA

Abstract The cumulative effects of molecular weight and concentration on the structural transitions in the electrospun polymer have been studied. Experiments have been conducted with water as the solvent for molecular weights of polyvinylalcohol (PVA) ranging from 9500 g/mol to 155,000 g/mol. The structural regimes for beads, beaded fibers, complete fibers and flat ribbons have been mapped. The development of a stable fiber structure generally corresponds to the onset of significant molecular entanglements.
THE DIFFERENTIATION OF WHITE ADIPOSE CELLS : An Electron Microscope Study

Differentiating white adipose tissue from presumptive and developing fat pads of newborn and young rats was fixed in buffered osmium tetroxide, embedded in Vestopal W, and examined in an electron microscope. Pre-adipose cells were found to be fibroblasts characterized by their spindle shape, long tenuous cytoplasmic extensions, and profuse endoplasmic reticulum. The developmental stages traced from fibroblast to mature adipose cell show a gradual change in cell shape, an accumulation of cytoplasm and non-membrane-bounded lipid, a decrease in the endoplasmic reticulum, and a change in shape of mitochondria. Transitory glycogen appears at mid-differentiation. Numerous smooth-membraned vesicles occur in the cytoplasm throughout differentiation. Pinocytosis is constantly evident. Cells of the multilocular stage are shown to differ from brown fat cells, particularly with respect to cytoplasmic membrane systems and mitochondria. No transport of particulate lipid from the lumen of the capillary to, or within, the adipose cell was detected, nor could any cell organelle be demonstrated to be visibly related to lipid synthesis and/or deposition.
Autosomal dominant transmission of the Pallister-Hall syndrome+

We describe a 9-year-old boy and his 34-year-old father with the Pallister-Hall syndrome. The proband had precocious puberty, imperforate anus, postaxial polydactyly, hypospadias, a hypothalamic mass, and a displaced pituitary gland. The father had polydactyly, a hypothalamic mass, and a flattened pituitary gland. We conclude that the most likely cause of the Pallister-Hall syndrome is a mutation in a gene inherited in an autosomal dominant manner.
Generation of dendritic cells from lentiviral vector-transduced CD34+ cells from HIV+ donors.

Dendritic cells hold promise as adjuvant for immunotherapy for cancer and infectious diseases. We demonstrate that a significant number of cryopreserved peripheral blood CD34+ cells from HIV-infected subjects can be transduced with a replication-incompetent lentiviral vector expressing HIV antigens. In addition, untransduced and transduced CD34+ cells from HIV-infected individuals were able to differentiate into dendritic cells with strong T-cell stimulatory capacity. Thus, cryopreserved CD34+ cells from HIV-infected subjects may prove useful for immunotherapy for HIV/AIDS. J. Med. Virol. 70: 183–186, 2003. © 2003 Wiley-Liss, Inc.
A comparison of mode I fracture behavior of fcc and bcc metallic materials : a discrete dislocation analysis

Abstract Mode I fracture behavior in fcc and bcc materials is analyzed using the discrete dislocation approach. Dislocations are modeled as line discontinuities residing in an isotropic linear elastic medium and interacting with each other through long-range stress fields. In addition, the short-range reactions underlying dislocation nucleation and annihilation are introduced to enable simulation of the evolution of the dislocation structure during loading. The motion of dislocations and their nucleation is considered to be controlled by thermal activation at higher temperatures and lower stress levels and by phonon-drag at lower temperatures and higher stress levels. A mode I crack is introduced into the model using a cohesive surface formulation. The results obtained show that differences in the orientation of the slip planes, relative to the low-cohesive strength {1 0 0} fracture planes, cause dislocations to promote crack tip blunting and plastic shielding in the case of the fcc material while such effects are only marginal in the case of the bcc material. Furthermore, temperature is found to have a pronounced effect on fracture toughness of the bcc material while its role in the fcc material is very small.
Extended validity of single segment stepwise integration schemes for solution of two-point boundary value problems☆

Abstract Results of studies conducted on application of stepwise integration schemes to sets of linear first ordei ordinary differential equations defining two-point boundary value problems are presented. Previous investigations recognized need for segmenting the integration interval into a number of smaller sub-intervals when boundary layer effects are present; this multi-segment scheme has been successfully utilized for stress analysis of shells of revolution and a rule of thumb suggested for establishing the required number of segments. Contrary to findings of previous investigations, the work here indicates that integration using a single segment may have a much wide range of application. Results of numerical studies are presented leading to the conclusion that the range of validity of a single segment solution is increased by a factor of six to ten over what has previously been suggested in the literature for two-point boundary value problems exhibiting boundary layer behavior.
Reconstitution of branching tubules from two cloned mammary cell types in culture

Abstract Rat mammary epithelial tumor cells from the line Rama 25 can grow into three-dimensional, multicellular structures when cultured on floating collagen gels. These structures include branching tubules reminiscent of ducts in glands, and the production of the tubules is studied here as a model of glandular morphogenesis. The cell line contains cells of two types which can be cloned and grown separately. Tubules are formed by neither cell type alone, but by combinations. The behavior of the two cell types suggests a mechanism for the growth of glands.
Mobile Thrombus on Device Leads in Patients Undergoing Ablation Identification, Incidence, Location, and Association With Increased Pulmonary Artery Systolic Pressure

Background—Mobile thrombi, not routinely recognized on transthoracic echocardiography, are frequently identified on cardiovascular implantable electronic device leads with intracardiac echocardiography (ICE) during ablation procedures. Their incidence, characteristics, and consequences have not yet been defined. Methods and Results—We used ICE to examine leads for thrombi and to measure the pulmonary artery systolic pressure in patients with a cardiovascular implantable electronic device presenting for ablation. Patient clinical characteristics, device type, and lead characteristics were correlated with presence of thrombi. Most patients had congestive heart failure (84%), with an average left ventricular ejection fraction of 40%. Thrombi were seen with ICE in 26 of 86 patients (30%) but were seen on transthoracic echocardiography in only 1 of the 26 patients. Thrombi on ICE were mobile, averaged 18±5.9 mm long by 4.4±2.3 mm wide, and were more commonly identified in the right atrium (n=25) than in the ri...
Effect of temperature on the myoglobin-facilitated transport of oxygen in skeletal muscle

An analysis of thermal effects on the facilitative transport of oxygen in skeletal muscle fibers is presented. Steady-state mass and energy transport balances are written and solved analytically or numerically using a finite-difference procedure. It is shown that no significant spatial thermal gradients exist due to internal reactions or bulk conduction effects across a muscle fiber. At typical muscle conditions, it is predicted that increased global temperature reduces the fraction of oxygenated myoglobin, increases local oxygen concentrations, and increases the percentage of oxygen flux attributed to oxy-myoglobin. The maximum supportable oxygen consumption rate, mO2max, is defined as the highest consumption rate sustainable without developing anoxic regions at the center of the fiber. By considering only temperature sensitive effects within fibers, mO2max is found to increase slightly with temperature at low temperatures. This increase is due to thermal effects on the diffusion coefficients as opposed to effects associated with the kinetics of the myoglobin-oxygen reaction. If the simulations include the temperature effect associated with oxygen solubility in blood plasma, mO2max decreases with temperature. A sensitivity analysis was performed by varying the values of relevant parameters. The maximum consumption rate was least affected by parameters associated with the kinetic and equilibrium constants and most affected by the diffusion coefficients and the concentration of myoglobin.
A refined nonlinear vibration absorber

Abstract Presented here is a theoretical study on how to use saturation phenomena to design nonlinear vibration absorbers and how to improve their stability and effective frequency bandwidth. The so-called original saturation control method uses 2 : 1 internal resonances and saturation phenomena to suppress steady-state vibrations of a dynamical system by connecting it to a second-order controller using quadratic position coupling terms, which do not really suppress vibration to zero as a linear vibration absorber does. However, a linear vibration absorber uses direct position feedbacks and splits one natural frequency of the original system into two and hence spill-over effects exist when the system is subjected to broad-band and/or transient excitations. Although a saturation controller does not split one natural frequency into two, one large-amplitude nonlinear solution coexists with a small-amplitude linear solution outside of the resonance area. Hence, the existence of spillover effects depends on initial conditions. A refined nonlinear vibration absorber is designed by using a quadratic velocity coupling term in the controller and adding a negative velocity feedback to the system. It is shown that the quadratic velocity coupling term enables a saturation controller to suppress system vibrations to zero. Moreover, the linear velocity feedback enhances the capability of suppressing transient vibrations and prevents the system from having the large-amplitude nonlinear response. Two equations describing the first-mode vibration of a stainless-steel beam and a saturation controller from the authors’ previous experimental work are used in this theoretical study. Both perturbation and direct numerical integration solutions are presented. Guidelines for designing nonlinear vibration absorbers are derived.
EIGENVALUES OF THE ONE-DIMENSIONAL SMOLUCHOWSKI EQUATION

The eigenvalues and eigenfunctions of the Smoluchowski equation are investigated for the case of potentials withN deep wells. The small parameter δ=kT/V, which measures the ratio of the thermal energy to a typical well depth, is used in connection with the method of matched asymptotic expansion to obtained asymptotic approximations to all the eigenvalues and eigenfunctions. It is found that the eigensolutions fall into two classes, namely (i) the top-of-the-well and (ii) the bottom-of-the-well eigensolutions. The eigenvalues for both classes of solutions are integer multiples of the squqres of the frequencies at the top or bottom of the various wells. The eigenfunctions are, in general, localized to the top or bottom of the corresponding well. The very small eigenvalues require special consideration because the asymptotic analysis is incapable of distinguishing them from the zero eigenvalue with multiplicityN. Another approximation reveals that, in addition to the true zero eigenvalue, there areN-1 eigenvalues of order exp(−δ). The case of other possible multiple eigenvalues is also examined.
Ultrastructure of photoreceptors and circadian pacemaker neurons in the eye of a gastropod,Bulla

Each of the paired cephalic eyes of the marine gastropod, Bulla, is about 0.5 mm in diameter and contains about 1000 large photoreceptors, small photoreceptors, numerous pigmented support cells and about 130 neurons. The photoreceptors are of three types: large (90 micron X 20-30 micron) dense ones (PRLD) with elaborate narrow microvilli and aggregates of 650 A clear vesicles in the cytoplasm; large clear ones (PRLC) with elaborate wide microvilli and aggregates of 650A clear vesicles; small slender receptors (PRS) with a tuft of microvilli and lacking vesicle aggregates. Neurons (15-25 micron) containing dense-core 1000 A vesicles are in the periphery of the retina or grouped in a collar around the neuropil below the photoreceptor layer. The 4-5 largest neurons are in the collar area. Correlation of neuron morphology with electrical activity was done with intracellular recording and Lucifer yellow injection of some of the larger neurons in the collar area whose action potentials contribute to the optic nerve impulses. Each one has an axon in the optic nerve and processes that go to the neuropil. They are the pacemaker neurons of the circadian rhythm in impulse frequency that is recorded from the optic nerve, since only their action potentials are correlated 1:1 with the optic nerve impulses. Gap junctions (with pentalaminar structure) are common between photoreceptors, glial cells, photoreceptors and glial cells, and neuronal processes in the neuropil, providing a basis for electrotonic coupling among retinal cells. There are about 2000 axons (diameter less than 3 micron) in the optic nerve, possibly one from each retinal photoreceptor and neuron plus efferent fibres from the brain. Accessory nerves, containing a few large axons, are seen in the optic nerve sheath.
Development of Models for Park Rangers' Perceived Isolation of National Park Service Areas

Asurvey of U.S. National Park Service (NPS) rangers examined perceived isolation, personality, and organizational variables. Park areas in a variety of isolated and nonisolated settings were sampled. Statistical indices in this study address issues of isolation previously noted as important in NPS areas. Indices relating to park distance from small urban areas reflect substantial elements of perceived isolation ratings. Models based on these indices provide more information regarding relative isolation perceptions than do personality, organizational, or existing official NPS classification variable models.
The New Legitimacy and International Legitimation: Civilization and South African Foreign Policy

In the years since the end of apartheid, South Africa has emerged from its status as an international pariah to a full fledged member of the international community. Riding a wave of new found legitimacy bolstered by a heroic myth surrounding President Mandela, South Africa began to rethink its role in the world. Perhaps more than Mandela, however, former President Thabo Mbeki laid claim to the title of Africa's spokesman to the world. Mbeki, through his African Renaissance , cast himself as the embodiment of the modern, postcolonial African blending African tradition and symbolism with the rhetoric of free markets and good governance. What this paper argues is that Mbeki's Renaissance highlights both what constitutes legitimate policies and behavior and the role of legitimacy and legitimation itself in international relations.
Isolation, cultivation, and characterization of normal human esophageal epithelial cells

Normal human esophageal epithelial cells can now be grown and serially propagated in cell culture either using serum-containing medium and lethally irradiated 3T3 fibroblasts to support epithelial cell growth or using hormone-supplemented, serum-free medium without a 3T3 “feeder” layer. The cells continue to express many differentiated functions characteristic of the native epithelium. When grown in serum-containing medium, the esophageal epithelial cell colonies are stratified and consist of a basal layer of dividing cells giving rise to the more differentiated cells in the upper cell layers. The cells contain keratin proteins and desmosomes between adjacent cells. The cells express other markers of terminal squamous differentiation, namely, involucrin and cross-linked envelopes. When grown in serum-free, hormone-supplemented medium, the colonies remain as a monolayer rather than stratifying because of the low levels of calcium required for optimal growth. Increased levels of calcium or the presence of serum (2.5% or greater) lead to stratification. The cells grown under serum-free conditions continue to express squamous differentiated properties as keratins, desmosomes (decreased numbers in low-calcium medium), involucrin, and cross-linked envelopes.
Kinetic and thermodynamic studies of cesium(I) sorption on hydrous silica

Batch sorption experiments of cesium, Cs+, on SiO2 . xH2O (silica gel) have been conducted with variable times of equilibration, amounts of silica gel (0.10-1.00 g), cesium concentrations (5.00 . 10-5-2.40 . 10-3M), ionic strengths (0.20-1.40M NaClO4), pH (2.50-7.70), and temperatures (273-333 K). The diffusion coefficient of Cs+ ion was calculated to be (9.19±0.86) . 10-11 m2 . s-1 under particle diffusion-controlled conditions. The sorption rate was (3.94±0.65) . 10-3 s-1 at 298 K, pH 7.70±0.05 in 0.20M NaClO4. The sorption data fits the Freundlich, Langmuir and Dubinin-Radushkevich (D-R) isotherms. Cesium sorption on 0.20 g silica gel decreased with ionic strength from (40.42±0.34)% in 0.20M NaClO4 to (6.35±0.40)% in 1.40M NaClO4, at pH(initial) 8.20±0.05. A gradual decrease in pH with increased ionic strength is consistent with a cation-exchange mechanism. Sorption of Cs+ on silica gel decreased with increased temperature, indicating an exothermic enthalpy. The presence of anions such as fluoride, carbonate, phosphate and oxalate in the aqueous medium did not influence the cesium sorption profile.
Prediction of MS/MS data. 1. A focus on pharmaceuticals containing carboxylic acids.

Metabolite identification is a necessary step in developing safe and effective drugs. Metabolite analysis typically involves rapid identification of the chemical composition of the metabolite by automated HPLC−MS methods, followed by the laborious process of identifying the structure of the metabolite. Since MS is typically utilized to identify the metabolite, it is logical to utilize MS/MS to structurally characterize the sample. However, interpretation of MS/MS data may not provide sufficient information, as fragmentation pathways are not well understood or predictable. Therefore, other more time-consuming methods of analysis are often undertaken. If the dissociation rules for low-energy MS/MS experiments were clearly defined for all classes of compounds, more information would be obtained from MS/MS data, and metabolite identification would proceed more rapidly. We are currently developing methods to define these fragmentation rules. By screening ∼100 carboxylic acids at a time and applying knowledge o...
High proton conductivity membrane with coconut shell activated carbon

An ideal proton exchange membrane (PEM) used in fuel cells must facilitate fast proton transport, insulate electron conduction, and exhibit adequate thermal and mechanical stability among others. One of the main issues with PEMs is the degradation of proton conductivity as a consequence of membrane dehydration. In this study, an effective bio-friendly solution is sought through the utilization of coconut-shell-based activated carbon (AC) that can act as a “molecular sponge”. Our experimental results demonstrate almost an order of magnitude improvement in proton conductivity with only 0.7 % AC particles and a significant enhancement in water sorption of more than 80 % without any compromise in mechanical properties. The mechanism of proton conductivity enhancement in Nafion/AC composite membrane is elucidated, and a new model of proton conductivity as a function of filler content is proposed exhibiting three distinct phases of activated carbon influence.
MANAGING METROPOLITAN GROWTH AND DEVELOPMENT IN ASIA

This paper examines selected problems of managing growth in large Asian cities. Managing the national urban system presents difficult problems because of the very high capital costs associated with absorbing population in the very large metropolitan areas. Cost savings from promoting a decentralized settlement pattern are small compared with reductions in nationwide infrastructure standards and other non-spatial strategies. Asian cities have not managed spatial decentralization very well. A sound approach may involve more intervention in some spheres (e.g. accelerating the supply of basic services to newly developed residential neighborhoods) and less intervention in others (e.g. prior selection of subcenters, large-scale land acquisition and other land use controls). Urban service delivery strategies have been hampered by the lack of resources, timidity in the introduction of cost recovery systems, and inadequate operations and maintenance.
Error analysis of the impulse excitation of vibration measurement of acoustic velocities in steel samples

Abstract The knowledge of the acoustic velocities in solid materials is crucial for several nondestructive evaluation techniques such as wall thickness measurement, materials characterization, determination of the location of cracks and inclusions, TOFD, etc. The longitudinal wave velocity is easily measured using ultrasonic pulse-echo technique, while a simple and accurate way to measure the shear wave speed would be a useful addition to the commonly available tools. In this work we use the impulse excitation of vibration, a very well known technique to determine the elastic constants of solid materials from the measurement of the lowest resonant frequencies excited by an impulse, to determine both longitudinal and transversal sound velocities for steel samples. Significant differences were found when comparing the longitudinal wave velocity with the one determined by a standard pulse-echo technique. Part of the difference was tracked back to the use of analytical formulas for the resonant frequencies, and corrected through the use of accurate numerical simulations. In this paper the systematic analysis of the possible error sources is reported.
Therapeutic approaches to posttraumatic stress disorder in infants and toddlers

In this paper, general guidelines and specific techniques that the authors have found helpful in the treatment of posttraumatic stress reactions during the infancy and toddler period are described. In treatment planning it is important to recognize that traumatic events affect infants and their families in a number of ways. Moreover, the rapid developmental changes occurring in the first 3 years strongly influence how a trauma is experienced. Taking these factors into account, the authors identify a number of important therapeutic principles, derived from work with older children and adults, that can be applied to the treatment of infants and toddlers. Specific therapeutic techniques are described in relation to the child's age and developmental level. Suggestions for working with parents are provided, as well as a brief discussion of the role of medication. The paper concludes with a summary of a clinical session with a traumatized toddler, illustrating the psychotherapeutic approaches that have been discussed. Ce travail discute la maniere dont les principes therapeutiques developpes dans le travail avec des enfants plus ǎges et des adultes peuvent ětre appliques au traitement de bebes et de jeunes enfants traumatises. Les evenements traumatiques affectent les bebes et leurs familles de plusieurs manieres. De plus, les changements rapides dans le developpement qui ont lieu durant les trois premieres annees de la vie influencent la facon dont un trauma est vecu. Des lignes directrices generales et des techniques therapeutiques specifiques sont decrites, en prenant en compte ces effets multiples et le niveau de developpement de l'enfant. Des suggestions quant au travail avec les parents sont offertes ainsi qu'une breve discussion du rǒle de la medication. Cet article se termine par un resume d'une session clinique avec un bebe traumatise illustrant ies approches psychotherapeutiques qui ont ete discutees.