cssi/SciSciGPT-SciSciNet huggingface dataset:
Promoter interactions in retrovirus vectors introduced into fibroblasts and embryonic stem cells.

Abstract The activity of the Moloney murine leukemia virus promoter is restricted in mouse embryonic stem cells. Gene expression with retrovirus vectors can be achieved in these cells if internal promoters are used. To address the possible influence of the viral enhancer sequences on expression from the internal promoter, we have constructed high-titer, self-inactivating retrovirus vectors which delete viral regulatory sequences upon integration in the host genome. We show that deleting most of the viral enhancer sequences has no significant effect on viral titer. This enhancer deletion leads to either an increase or a decrease in the amount of RNA transcribed from the internal promoter, but no consistent change can be found with any type of vector. The same changes in expression from the internal promoter observed in embryonic stem cells are also observed in 3T3 fibroblast cells, in which the viral promoter is active. These results indicate that viral regulatory elements influence expression from an internal promoter independently of expression from the virus promoter.
A fast approximation to the rectilinear Steiner tree problem

A new algorithm is presented for the construction of a suboptimal rectilinear Steiner tree (RST). The algorithm utilizes the notion of possible Steiner points to obtain a suboptimal solution of the problem in O(n/sup 2/) time. An extension of the algorithm allows the creation of RSTs that are stable under rerouting. Implementation of the algorithm on a number of randomly generated examples indicates fast CPU execution time and good quality of solutions when compared to other known algorithms. >
Noradrenergic dysfunction in Alzheimer's disease

The brain noradrenergic system supplies the neurotransmitter norepinephrine throughout the brain via widespread efferent projections, and plays a pivotal role in modulating cognitive activities in the cortex. Profound noradrenergic degeneration in Alzheimer's disease (AD) patients has been observed for decades, with recent research suggesting that the locus coeruleus (where noradrenergic neurons are mainly located) is a predominant site where AD-related pathology begins. Mounting evidence indicates that the loss of noradrenergic innervation greatly exacerbates AD pathogenesis and progression, although the precise roles of noradrenergic components in AD pathogenesis remain unclear. The aim of this review is to summarize current findings on noradrenergic dysfunction in AD, as well as to point out deficiencies in our knowledge where more research is needed.
Rural economic development under devolution: A test of local strategies

During the past 30 years, the federal government has transferred more responsibility for the control, development, and support of public policy to states and local communities in a process known as...
FDI, Education, and Economic Growth: Quality Matters

In this paper, we revisit the results from the influential study by Borensztein et al. (Journal of International Economics 45:115–135, 1998), which argues that inward foreign direct investment (FDI) promotes the economic growth in a less developed host country only when the host country obtains a threshold level of secondary schooling. Borensztein et al. (Journal of International Economics 45:115–135, 1998) only focus on the quantity of education. We take into consideration both the quantity and the quality of education. We adjust the original schooling data in Borensztein et al. (Journal of International Economics 45:115–135, 1998) by two quality of education indices and re-estimate their model. We find that the complementarity between inward FDI and schooling still exists, but the threshold level of schooling in our study is lower than the threshold calculated in Borensztein et al. (Journal of International Economics 45:115–135, 1998). Our results support the importance of education quality and suggest that with improved quality of education, it does not take as much quantity of schooling, as established in Borensztein et al. (Journal of International Economics 45:115–135, 1998), for inward FDI to have a positive impact on economic growth in the host country.
Structure and Property of Interfaces in ARB Cu/Nb Laminated Composites

Bulk Cu/Nb multilayered composites with high interfacial content have been synthesized via the accumulative roll bonding (ARB) method. Experimental characterization shows that these multilayers with submicronmeter and nanometer individual layer thicknesses contain a predominant, steady-state interface with the Kurdjumov–Sachs orientation relationship joining the mutual {112} planes of Cu and Nb. In this article, we overview microscopy and simulation results on the structure of this interface at an atomic level and its influence on interface properties, such as interface shear resistance and its ability to absorb point defects and nucleate dislocations nucleation.
Fluorescence properties of Laurdan in cochleate phases.

Cochleates are lipid-based delivery system that have found application in drug and gene delivery. They are precipitates, formed as a result of interaction between cations (e.g. Ca2+) and negatively charged phospholipids such as phosphatidylserine (PS). In the present study, we investigated the utility of fluorescent probe Laurdan (6-dodecanoyl-2-dimethylamino naphthalene) to monitor cochleate phase formation. Following addition of Ca2+ to Laurdan labeled lipid vesicles comprised of brain phosphatidylserine (BPS), a significant blue shift in the emission peak maximum of Laurdan was observed and the spectral features were distinct from those observed for the gel and liquid-crystalline (LC) phases. This is consistent with the formation of anhydrous cochleate cylinders that was further confirmed by electron microscopy studies. Due to dipolar relaxation, excitation and emission generalized polarization (GPEx and GPEm) indicate transition from a LC to a rigid and dehydrated (RD) cochleate phase. These spectral changes were utilized to monitor the influence of lipid composition, ionic strength and lamellarity on the formation of cochleate phase. The results indicated that the presence of phosphatidylcholine (PC) and bulk Na+ concentration influenced the formation of cochleate structures from small unilamellar vesicles (SUV) and multilamellar vesicles (MLV) composed of PS. The presence of PC and higher bulk Na+ concentration stabilized the PS vesicles against collapse and total loss of contents, intermediate molecular events in the formation of cochleate structures. From these studies, we conclude that Laurdan fluorescence is a sensitive and a rapid method to detect cochleate phase formation.
A segmentation strategy for the 1980’s: Profiling the socially-concerned market through life-style analysis

Life-style analysis was performed to determine the activities, opinions and interests of the socially-ecologically concerned consumer. The more “concerned” consumer was found to be more physically active, family oriented, liberal and self-assured than those not demonstrating such concern, and more rational and deliberate in respect to their consumer behavior.
Novel polymerase gamma ( POLG1 ) gene mutation in the linker domain associated with parkinsonism

Mutations in the POLG1 gene have variable phenotypic presentations and a high degree of clinical suspicion is necessary for their recognition. Parkinsonism and ataxia are the most common movement disorders associated with POLG1 mutations but no phenotype-genotype correlation has been established. We identified a male patient with progressive external ophthalmoplegia who also developed a progressive bradykinesia, rigidity and camptocormia in the third decade. Parkinsonism was partially responsive to dopaminegic replacement. His father and brother had reportedly similar clinical problems. Genetic analysis identified a novel mutation p.K512M in the POLG1 gene. This report further expands the spectrum of POLG1-associated neurologic problems with the report of a novel mutation in the linker region of the gene, which are rarely associated with parkinsonism.
A life with horses: It's been a great ride!

In 2010 Doug Antczak was the recipient of the Distinguished Veterinary Immunologist Award of the Veterinary Immunology Committee of the International Union of Immunological Societies. Dr. Antczak is the Dorothy Havemeyer McConville Professor of Equine Medicine at the Baker Institute for Animal Health in the College of Veterinary Medicine at Cornell University. His research focuses on immunological and genetic aspects of the fetal-maternal relationship in the horse. This includes studies of major histocompatibility complex (MHC) genes and molecules, the regulation of their expression in the placenta, the composition and function of uterine lymphocytes, and alterations in maternal immune reactivity during pregnancy. For this research Dr. Antczak developed a herd of purpose-bred horses selected for homozygosity at the MHC. These horses are a unique genetic resource in equine immunology. During his career Dr. Antczak has mentored over 20 graduate students and post-doctoral fellows, many of whom have gone on to independent careers in immunology research. Dr. Antczak has made contributions to equine immunology, genetics, and reproduction, and collaborated widely with scientists in each of these disciplines. Through his relationship with the Havemeyer Foundation, Dr. Antczak has been a catalyst for cooperative research through a series of Havemeyer Foundation Workshops initiated over 25 years ago. Since 1995 he has been a principal participant in the international Horse Genome Project collaboration furthering his equine immunology research through genomic applications. In 2009 Dr. Antczak was inducted into the University of Kentucky's Equine Research Hall of Fame.
Implications of cytoskeletal interactions for cellular architecture and behaviour

The three major filamentous components of the cytoskeleton (microfilaments, microtubules and intermediate filaments) do not just coexist in the cell, but interact with each other in various ways. This paper discusses some examples of structural interactions visualized in critical-point-dried cells by stereoscopic high-voltage electron microscopy. The relative contribution of two classes of interactions to the consolidation of different cytoskeletal domains is considered. One class is represented by T-junctions (end-to-side contacts) of actin filaments with other filaments, and the other by 3 nm links. Attention is then turned to what may be called the behavioural consequences of cytoskeletal interactions. As an example of a coordinated interplay between events at the cell membrane and the cytoskeleton, we discuss changes in cytoskeletal organization of polymorphonuclear leucocytes upon stimulation with a chemotactic factor. These changes culminate in some cells in centriole separation and the establishment of two microtubule asters, each centred around a single centriole.
Finite Element Modeling of Structures With L-Shaped Beams and Bolted Joints

Due to bending-torsion coupled vibrations of the L-shaped beams and numerous uncertainties associated with the bolted joints, modeling structures with L-shaped beams and bolted joints is a challenging task. With the recent development of the modeling techniques for L-shaped beams by the authors (He and Zhu, 2009, "Modeling of Fillets in Thin-Walled Beams Using Shell/Plate and Beam Finite Elements, " ASME J. Vibr. Acoust., 131(5), p. 051002), this work focuses on developing new finite element (FE) models for bolted joints in these structures. While the complicated behavior of a single bolted connection can be analyzed using commercial FE software, it is computationally expensive and inefficient to directly simulate the global dynamic response of an assembled structure with bolted joints, and it is necessary to develop relatively simple and accurate models for bolted joints. Three new approaches, two model updating approaches and a predictive modeling approach, are developed in this work to capture the stiffness and mass effects of bolted joints on the global dynamic response of assembled structures. The unknown parameters of the models in the model updating approaches are determined by comparing the calculated and measured natural frequencies. In the predictive modeling approach, the effective area of a bolted connection is determined using contact FE models and an analytical beam model; its associated stiffnesses can also be determined. The models developed for the bolted joints have relatively small sizes and can be easily embedded into a FE model of an assembled structure. For the structures studied, including a three-bay space frame structure with L-shaped beams and bolted joints, and some of its components, the errors between the calculated and measured natural frequencies are within 2% for at least the first 13 elastic modes, and the associated modal assurance criterion values are all over 94%.
Vessel distensibility and flow distribution in vascular trees

In a class of model vascular trees having distensible blood vessels, we prove that flow partitioning throughout the tree remains constant, independent of the nonzero driving flow (or nonzero inlet to terminal outlet pressure difference). Underlying assumptions are: (1) every vessel in the tree exhibits the same distensibility relationship given by $D/D_0 = f(P)$ where $D$ is the diameter which results from distending pressure $P$ and $D_0$ is the diameter of the individual vessel at zero pressure (each vessel may have its own individual $D_0$). The choice of $f(P)$ includes distensibilities often used in vessel biomechanics modeling, e.g., $f(P) = 1 + \alpha P$ or $f(P) = b + (1-b) \exp(-c P)$, as well as $f(P)$ which exhibit autoregulatory behavior. (2) Every terminal vessel in the tree is subjected to the same terminal outlet pressure. (3) Bernoulli effects are ignored. (4) Flow is nonpulsatile. (5) Blood viscosity within any individual vessel is constant. The results imply that for a vascular tree consistent with assumptions 2–5, the flow distribution calculations based on a rigid geometry, e.g., $D=D_0$, also gives the flow distribution when assuming the common distensibility relationships.
A New Weight-Dependent Direct Statistical Approach Model

A weight-dependent capability is inserted into the direct statistical approach (DSA) to optimize splitting and Russian roulette (RR) parameters in Monte Carlo particle transport calculations. In the new model, splitting or RR is carried out on a progenitor arriving at a surface in such a way that the weight of the progeny is fixed (for the particular surface). Thus, the model is named the DSA weight line model. In the presence of weight-dependent games, all components of the second moment, and the time, are not separable. In the absence of weight-dependent games, the component of the second moment describing the weight-dependent splitting or RR is still not separable. Two approximations are examined to render this component separable under these circumstances. One of these approximations, named the noninteger approximation, looks promising. The new DSA model with the noninteger approximation is tested on four sample problems. Comparisons with the previous weight-independent DSA model and with the MCNP (version 4a) weight window generator are made.
Simultaneous quantification of human cardiac alpha- and beta-myosin heavy chain proteins by MALDI-TOF mass spectrometry

We have developed a novel method for quantifying protein isoforms, in both relative and absolute terms, based on MALDI-TOF mass spectrometry. The utility of the approach is demonstrated by quantifying the alpha and beta protein isoforms of myosin heavy chain (MyHC) in human atrial tissue. Alpha-MyHC (726-741) and beta-MyHC (724-739) were identified as isoform-specific tryptic peptides. A calibration curve was constructed by plotting ion current ratios against molar ratios of the two peptides prepared synthetically. MyHC was digested by trypsin and the ion current ratio determined for the two tryptic peptides. The ion current ratio was converted to the peptide ratio and hence the isoform ratio by reference to the standard curve. The accuracy of the method was confirmed by a comparison between these results and those determined by an established method of MyHC isoform ratio determination. So that the molar ratio could be converted to absolute values, a third peptide, an analogue of the two peptides being measured, was synthesized for use as an internal standard (IS). The measured ion current ratios of synthetic alpha-MyHC (726-741), beta-MyHC (724-739), and IS peptides were used to generate standard curves. A known quantity of the IS was added to the MyHC digests. The measured ion current ratios were converted to the actual quantities of the isoform-specific peptides and hence the actual quantity of each protein isoform by reference to the standard curves. This method is of general applicability, especially when isoform quantification is required.
Lessons learned from mice and man: Mimicking human allergy through mouse models

Abstract The relevance of using mouse models to represent human allergic pathologies is still unclear. Recent studies suggest the limitations of using models as a standard for assessing immune response and tolerance mechanisms, as mouse models often do not sufficiently depict human atopic conditions. Allergy is a combination of aberrant responses to innocuous environmental agents and the subsequent TH2-mediated inflammatory responses. In this review, we will discuss current paradigms of allergy — specifically, TH2-mediated and IgE-associated immune responses — and current mouse models used to recreate these TH2-mediated pathologies. Our overall goal is to highlight discrepancies that exist between mice and men by examining the advantages and disadvantages of allergic mouse models with respect to the human allergic condition.
Signal analysis and modeling of wind turbine clutter in weather radars

Lately, the continuing expansion of wind energy industry has led to the installation of several wind farms which are often in the vicinity of the weather radars. This is a source of growing concern for the weather radar community since wind turbines interfere with the normal operation of the weather radars. The wind turbine tower can drive the receivers into saturation and the Doppler shift from the moving blades can introduce errors in the estimation of wind speed, reflectivity and rainfall rates. The radar cross-section of the wind turbines has a large temporal and spatial variation which poses additional difficulties for traditional clutter filtering algorithms. This paper presents a first-order theoretical model of the radar signature of a wind turbine that can be helpful in deducing its unique features to be incorporated in filtering out the wind turbine clutter. A comparison with the observations from an S-band radar is made later in the paper.
A cryogenic device for reversibly blocking transmission through small regions of the spinal cord white matter

A simple cryogenic device is described. This device is capable of cooling neural tissue in contact with the probe and maintaining the tissue at the desired temperature for extended periods of time. The cold probe can thereby reversibly block neural transmission through small portions of the spinal cord white matter. Interruption of axonal transmission is achieved by placing the tip of the device in contact with the exposed surface of the spinal cord and cooling the tip of the probe to −1 to +2°C. The investigator monitors the tip temperature and adjusts the pump rate to maintain a constant tip temperature. The cross-sectional area under the probe where effective transmission block is achieved is about 1.5 mm2 which approximates the size of a single funiculus in the cat thoracic spinal cord. The cryogenic device was constructed for less than $700. The properties of this device were studied in physiologic experiments in cats. This device reversibly, selectively and repeatedly blocked the ascending mass action potential in the dorsolateral funiculus, transmission through ascending spinal axons in the dorsal columns, transmission through axons of spinal dorsal horn cells, the descending inhibitory input to the dorsal horn and the activity of thalamic nociceptive neurons. The reversible cold block effects on single units were observed for the duration of the experiments (up to 18 h) with no detectable damage to the underlying tissue. The physiologic effects of the cold block were usually reversed a few minutes after rewarming, although in some cases it took up to 40 min for the complete reversal of the cold block. This cryogenic device is useful for studying spinal cord pathways.
Variance reduction techniques in stochastic shortest route analysis: application procedures and results

Abstract Variance reduction techniques are of much interest to simulation practitioners. However, they typically present formidable difficulties in their implementation, and are, therefore, not widely used. These difficulties stem from the lack of well defined application procedures for the various techniques which are available. This research focuses on the development of application procedures for three variance reduction techniques: antithetic sampling, control variates, and stratified sampling. These procedures are developed for use in stochastic shortest route analysis. The procedures are supported by sound theoretical development which assures that no technique will result in a variance increase. Further, one technique guarantees a reduction in variance of the estimates obtained over direct simulation. We also provide extensive application results over a wide range of network characteristics. The results of these applications indicate that all of the variance reduction techniques investigated work well. Antithetic sampling was found to be far superior to the other techniques and can be generally recommended for use.
In-Situ Infrared Study of the Synthesis of Polyaniline Under Acid and Neutral pH

In-situ infrared study of polyaniline (PANI) synthesis showed that the reaction initiated at pH = 1.5 produced a granule PANI microstructure via para-linked dimers of 4-aminodiphenylamine, exhibiting γ(C–H) at 802 cm−1; the reaction initiated at pH = 5.0 and 7.0 produce fiberous, and planar microstructures via ortho-linked dimers of 1,2-aminodiphenylamine and phenazine, exhibiting γ(C–H) at 738 and ν(C=N) at 1446 cm−1. The doped PANI that was produced at pH less than 5.0 showed a feature-less IR background absorption above 1600 cm−1. This absorption could correspond to π-electron delocalization as an indicative of polyaniline conductivity.
Vaccination mandates vs opt-out programs and rates of influenza immunization.

TotheEditor:TheResearchLetterbyDrChapmanandcolleagues 1 demonstrated that an opt-out strategy for influenzaimmunizationsignificantlyimprovedvaccinationrates compared with an opt-in approach. Influenza immunizationratesforhealthcareworkershavehistoricallybeenlow, 2 despite strong recommendations from national organizations. Any method that will improve these rates is potentially useful. However, we were struck by how low the rates achieved in this study actually were. Even in the opt-out group, the vaccination rate of 45% barely exceeded the national average for health care workers (44%), 2 far too low. One of the keystudyfindingswasthatofthe221participantsintheoptout group who retained an appointment and were sent a reminder email, only 106 of them (48%) eventually were vaccinated. Thus, while an opt-out approach may be useful, it does not appear to be the answer to achieving high rates. VirginiaMasonMedicalCenter 3 andBJCHealthCare 4 have demonstrated that a mandatory health care worker influenzaimmunizationprogramisfeasibleandcanmaintainimmunization rates above 98%. We believe that this approachshouldbemorewidelyimplementedthroughoutthe
Intrahippocampal Injections of Exogenous β-Amyloid Induce Postdelay Errors in an Eight-Arm Radial Maze

Alzheimer's disease is characterized by the progressive loss of short-term memory and the accumulation of large amyloid plaques, the primary core of which is the β-amyloid 1-40 (βA4) peptide. It has been suggested that βA4 plays a causative role in the memory degeneration seen in Alzheimer's patients. The current study was designed to test the effects of bilateral intrahippocampal injections of βA4 on performance in a radial arm maze foraging task with a delay imposed following the fourth choice. Eight Sprague–Dawley rats were injected with either βA4 (10−3M) or vehicle (HPLC buffer) immediately prior to testing in the maze. Although βA4 did not impair performance on the predelay choices, it did significantly increase errors immediately postdelay. These results suggest that contrary to previous findings, βA4 does have acute effects when challenged with a short-term memory load and may play a significant role in some memory deficits seen in Alzheimer's disease.
Energy-Efficient Cluster-based Distributed Estimation in Wireless Sensor Networks

In this paper, we consider the cluster-based distributed estimation in wireless sensor networks where energy is a constrained resource. First, we present a hybrid cluster-based estimator and show its potential to save energy while keep the estimation performance. Next the optimal tradeoff between the cluster size and the number of clusters is analyzed for a special network - ring network. Then, we propose two greedy algorithms to cluster the general sensor networks to minimize the total energy cost of cluster-based estimation scheme by modelling the network as a directed or undirected graph. Simulation results not only show that the energy cost is reduced by cluster-based estimation scheme compared with the parallel estimation scheme while keeping the estimation performance, but also show that more energy is saved by our proposed clustering methods compared with the k-mean clustering method.
Energy Loss Calculations of Moving Defects for General Holographic Metrics

We extend the ideas of using AdS/CFT to calculate energy loss of extended defects in strongly coupled systems to general holographic metrics. We find the equations of motion governing uniformly moving defects of various dimension and determine the corresponding energy loss rates in terms of the metric coefficients. We apply our formulae to the specific examples of both bulk geometries created by general $\mathrm{D}p$-branes, as well as to holographic superfluids. For the $\mathrm{D}p$-branes, we find that the energy loss of our defect, in addition to the expected quadratic dependence on velocity, depends on velocity only via an effective blue-shifted temperature---despite the existence of a microscopic length scale in the theory. We also find, for a certain value of $p$ and dimension of the defect, that the energy loss has no dependence on temperature or velocity other than the aforementioned quadratic dependence on velocity. For the superfluid example, we find agreement with previous results on the existence of a cutoff velocity, below which the probe experiences no drag force. For both examples we can easily extend the equations of motion and energy loss to defects of larger dimension.
Trends in adolescent and young adult health in the United States

This review presents a national health profile of adolescents and young adults (ages 10-24). The data presented include trends on demographics, mortality, health-related behaviors, and healthcare access and utilization, as well as the most significant gender and racial/ethnic disparities. Although the data show some improvement, many concerns remain. Encouraging trends-such as decreases in rates of homicide, suicide, and some measures of reproductive health-appear to be leveling off or, in some cases, reversing (e.g., birth and gonorrhea rates). Large disparities, particularly by race/ethnicity and gender, persist in many areas. Access to quality healthcare services remains a challenge, especially during young adulthood. Policy and research recommendations to improve health during these critical periods in the lifespan are outlined.
27 INFANTS WITH BIRTHWEIGHTS LESS THAN 1000 GRAMS: THE FIRST THREE YEARS

As the survival of infants born weighing < 1000 grams has become more assured, pediatricians are now faced with questions related to the quality of these infants1 lives. Our purpose is to describe a population of 34 very low birthweight infants (BW < 1000 gms) transferred to Children's Hosp. of Phila. NICU between 6/80 and 4/83. 9 of these infants weighed <750 gms at birth. 94 infants weighing 1000–1750 grams with similar neonatal conditions served as a comparison group. The survival rate of the 2 groups was 53% and 83%, respectively. The mean BW & GA of the groups was 821 ± 168 gms vs 1376 ± 218 gms and 28 ± 2 wks vs 31 ± 2 wks. Serial assessments of neurologic and intellectual development were performed using a modified Amiel-Tison & Bayley Scale Assessment or Reynell-Zinkin Scales (visually handicapped infants). Developmental status was defined as normal if scores were within 1SD, mild-mod delayed if between −1 & −2 SD and severely delayed if < −2SD. Results are based on the most recent evaluation (mean age 25 months). Comparing <1kg to ≥1kg infants revealed a 9% vs 1% rate of visual impairment (p<05) and 6% vs 4% as having cerebral palsy (NS). The table reveals no significant differences in developmental status between groups. Conclusions: Although there is an initially high mortality rate, those <1kg infants who do survive may experience more visual impairment due to RLF but are similar to larger BW infants in developmental and neuromuscular status in their toddler years.
Does Local Irradiation Affect Gastric Emptying in Humans

The authors measured gastric emptying in 13 patients undergoing radiation therapy to the chest, abdomen, or pelvis for nongastrointestinal cancer to investigate whether gastric emptying (GE) was altered by this therapy. Symptoms and weight were monitored at regular intervals. Patients served as their own controls and were compared to a group of healthy subjects. When studied prior to radiation therapy (baseline), cancer patients had a gastric emptying rate that was similar to a healthy control group (t1/2 mean+/-SEM 92.0+/-15.3 vs. 80.4+/-8.2 min). Irradiation did not change the emptying rate, either after the first dose (early) of 180 cGy (t1/2 99.5+/-17.9) or after 2 weeks of therapy (late) with 3000 cGy (t1/2 75.5+/-7.3). There was no correlation of radiation field or tumor type with gastric emptying rate. Two of the 13 patients experienced nausea and vomiting during their course of radiation, but their gastric emptying was unchanged from baseline.
A general theory of matrix transformation and its application to quantum mechanical problems

A general formalism is given to construct a transformation matrix TAB which connects two matrices A and B of order n × n satisfying any given polynomial equations of degree r(≤n). The matrix TAB is given explicitly by a polynomial of degree (r − 1) in A and B. A special case where B is a diagonal matrix equivalent to A leads to a general theory of matrix diagonalization. The formalism contains the projection operator method as a special case. Illustrative examples are given on the Dirac theory of the electron and the basic 2 × 2 spinor representation of the proper orthochronous Lorentz group; the latter is completely prameterized by the spatial rotation and the velocity of the parallel translation.
The Interaction of Atomic Hydrogen with Ni, Pd, and Pt Clusters

Abstract Electronic structures of small Ni, Pd, and Pt clusters containing atomic hydrogen have been calculated by the SCF Xα SW method, including relativistic effects. Hydrogenmetal bonding is dominated by d-orbitals for Pd and Pt and s-orbitals for Ni, consistent with photoemission spectra for hydrogen chemisorbed on and dissolved in these metals. The results, in conjunction with the concept of orbital electronegativity, suggest why hydrogen solubility and catalytic reactivity vary among these metals.
The Effect of Polyclonal Anti-TNFα Antibody on TNFα Gene Expression, Lethality and Glucoregulation in Suckling Rats with Endotoxic Shock † 1377

Gram negative septic shock (shock) is a major medical problem in the newborn because of its high mortality and morbibidity. TNFα is a key mediator in shock. Anti-TNFα antibodies (Abs) have been shown to have beneficial effects in shock induced by endotoxin (LPS) but not in shock induced by abdominal sepsis. Plasma endotoxin concentration increases within a short period after intraperitoneal (ip) LPS injection and declines rapidly. TNFα increases in a time-dependent manner after LPS injection. As TNFα induces TNFα gene expression, we hypothesize that Abs decrease not only plasma TNFα levels, but also TNFα gene expression, resulting in a decrease in mortality in endotoxic shock. In the present study, TNFα mRNA abundance in the liver was measured. Plasma glucose and lactate concentrations were determined.
The use of large-scale aerial photography to inventory and monitor arid rangeland vegetation.

Interpretation of large-scale color infrared and color aerial photography can be a labor- and cost-effective means to make inventory of and monitor rangelands while maintaining accuracy. Ground measurements of total vegetation cover, tree, shrub and cacti cover at Organ Pipe Cactus National Monument were taken in 1975 and 1984. Estimates of ground vegetation cover made using large scale (1:1200) color and color infrared aerial photography were compared to these ground measurements. High correlation coefficient values exist between color infrared transparency estimates and ground measurements of total vegetation cover (r = 0.972) and shrub cover (r = 0.891). Correlation coefficients were similarly high when matching color prints against ground measurements of total cover (0-976) and shrub cover (0.858). Estimates from color infrared film transparencies corresponded better with ground measurements for both tree and cactus cover, with r values of 0.685 and 0-812 respectively, than the estimates from color print photographs with r values of 0.501 for tree cover and 0.246 for cactus cover.
Deciphering the role of APP in synaptic function

Results We seek to understand the physiological functions of APP in neurons and synapses using in vivo mouse models and in vitro culture systems. Analysis of the APP knockout mice allows us to identify a functional role of APP in synaptic plasticity and learning and memory. Our investigation of mice deficient in APP and its homolog APLP2 establishes an essential role of APP family protein in mediating cholinergic synaptic structure and neurotransmission in both peripheral neuromuscular synapse and central cholinergic neurons. By creating an APP conditional allele, we demonstrate that APP is required in both pre- and postsynaptic terminals; and that pre- and postsynaptic APP interact to mediate synaptic structure and function. These in vivo findings are supported by in vitro mixed-culture studies, which reveal that APP potently induces synaptogenesis. Independent of the synaptic adhesion property that requires the full-length protein, we found that the soluble secreted APP ectodomain mediates transcription of genes related to aging and amyloid sequestration. Conclusion Our studies identify APP as synaptic adhesion and signaling molecules, which are mediated by distinct functional domains. Perturbation of these activities may contribute to synaptic dysfunction and AD pathogenesis.
Thoracic malformation with early-onset scoliosis: effect of serial VEPTR expansion thoracoplasty on lung growth and function in children

The effect on pulmonary function of serial VEPTR expansion thoracoplasty was studied longitudinally in anesthetized children with spondylothoracic dysplasia using a special mobile unit. The median age of 24 children at the start of surgery was 4.6 years (1.8-10.8) and most exhibited a moderate-to-severe restrictive lung defect. After a median of 3.2 years (1.0-6.5), their forced vital capacity (FVC) was found to have increased by an average of 11.1%/year. The rate of increase was greater in children who were younger than 6 years at the start of the study than in older children (14.5% versus 6.5%, p<0.01). The average specific respiratory system compliance (C(rs)) was mildly-to-moderately decreased at the start, and over the study it decreased on average to 56% of the initial value in spite of clinically successful expansion thoracoplasty and lung growth, indicating increasing stiffness of the thorax with growth.
Mesh color sharpening using Laplace-Beltrami operator

This paper presents a new method for mesh color sharpening using the discrete Laplace-Beltrami operator, which is an approximation of second order derivatives on irregular 3D meshes. The one-ring neighborhood is utilized to compute the Laplace-Beltrami operator. The color for each vertex is updated by adding the Laplace-Beltrami operator of the vertex color weighted by a factor to its original value. Different discretizations of the Laplace-Beltrami operator have been proposed for geometrical processing of 3D meshes. This paper utilizes several discretizations of the Laplace-Beltrami operator for sharpening 3D mesh colors and compares their performance. Experimental results demonstrated the effectiveness of the proposed algorithms.
Academic and personality correlates of career indecision in medical students entering training

Summary The academic and personality correlates of medical career indecision were investigated in two separate studies. In the first, the effect of career indecision on academic performance was examined in a group of ninety-eight (eighty male, eighteen female) medical students entering Texas Tech University School of Medicine over a 2-year period. These medical students voluntarily completed the Medical Specialty Preference Inventory (MSPI) as part of a routine preadmission test battery. Subjects were assigned to one of three conditions—decided, high-interest undecided and low-interest undecided—based on results from the MSPI. As predicted, ‘low-interest undecided’ students achieved significantly lower initial medical school grades relative to ‘decided’ students, whereas ‘high-interest undecided’ students did not differ from the ‘decided’ students. The second study investigated the influence of career indecision upon personality. Subjects for this study were eighty-eight (sixty-six male, twenty-two female) medical students entering Texas Tech University School of Medicine over a 1-year period. These students voluntarily completed the MSPI and several personality measures as part of a pre-admission test battery. The results only partially supported the stated hypotheses. Although ‘low-interest undecided’ students demonstrated less personal integration compared with ‘decided’ students, they were no more anxious.
Palladium-catalyzed decarboxylative rearrangements of allyl 2,2,2-trifluoroethyl malonates: direct access to homoallylic esters

Homoallylic esters are obtained in a single transformation from allyl 2,2,2-trifluoroethyl malonates by using a Pd(0) catalyst. Facile decarboxylation of allyl 2,2,2-trifluoroethyl malonates is attributed to a decrease in pKa compared to allyl methyl malonates. Subsequent reduction of the homoallylic 2,2,2-trifluoroethyl ester provides a (hydroxyethyl)cyclopentenyl derivative that represents a key intermediate in the synthesis of carbocyclic nucleosides. A select allyl 2,2,2-trifluoroethyl malonate undergoes a decarboxylative Claisen rearrangement to provide a regioisomeric homoallylic ester.
Assessing temporal clear-sky errors in assimilation of satellite CO 2 retrievals using a global transport model

Abstract. The Orbiting Carbon Observatory (OCO) and the Greenhouse gases Observing SATellite (GOSAT) will make global observations of the total column dry-air mole fraction of atmospheric CO2 (XCO2) starting in 2008. Although satellites have global coverage, XCO2 retrievals will be made only a few times each month over a given location and will only be sampled in clear conditions. Modelers will use XCO2 in atmospheric inversions to estimate carbon sources and sinks; however, if satellite measurements are used to represent temporal averages, modelers may incur temporal sampling errors. We investigate these errors using a global transport model. Temporal sampling errors vary with time and location, exhibit spatially coherent patterns, and are greatest over land and during summer. These errors often exceed 1 ppm and must be addressed in a data assimilation system by correct simulation of synoptic CO2 variations associated with cloud systems.
Solution behavior of polyethylene oxide in water as a function of temperature and pressure

A model of the solution behavior for hydrosoluble polymers [based on a model of Matsuyama and Tanaka, Phys. Rev. Lett. 65, 341 (1990)] is introduced that accounts for hydrogen bonding of solvent molecules onto polymer chains. In the limit of small volume fraction of H-bonded solvent molecules, the resulting free energy has the standard Flory-Huggins form with a good solvent contribution to the effective \ensuremath{\chi} parameter coming from the fraction of solvents H bonded to the chain. This simple theory is capable of semiquantitatively explaining the experimental temperature-concentration (T-\ensuremath{\varphi}) and temperature-pressure (T-P) phase diagrams of polyethylene oxide in water.
Murine fetal echocardiography.

Transgenic mice displaying abnormalities in cardiac development and function represent a powerful tool for the understanding the molecular mechanisms underlying both normal cardiovascular function and the pathophysiological basis of human cardiovascular disease. Fetal and perinatal death is a common feature when studying genetic alterations affecting cardiac development 1-3. In order to study the role of genetic or pharmacologic alterations in the early development of cardiac function, ultrasound imaging of the live fetus has become an important tool for early recognition of abnormalities and longitudinal follow-up. Noninvasive ultrasound imaging is an ideal method for detecting and studying congenital malformations and the impact on cardiac function prior to death 4. It allows early recognition of abnormalities in the living fetus and the progression of disease can be followed in utero with longitudinal studies 5,6. Until recently, imaging of fetal mouse hearts frequently involved invasive methods. The fetus had to be sacrificed to perform magnetic resonance microscopy and electron microscopy or surgically delivered for transillumination microscopy. An application of high-frequency probes with conventional 2-D and pulsed-wave Doppler imaging has been shown to provide measurements of cardiac contraction and heart rates during embryonic development with databases of normal developmental changes now available 6-10. M-mode imaging further provides important functional data, although, the proper imaging planes are often difficult to obtain. High-frequency ultrasound imaging of the fetus has improved 2-D resolution and can provide excellent information on the early development of cardiac structures 11.
Bioaccumulation, Subcellular Distribution, and Trophic Transfer of Copper in a Coastal Marine Diatom

Cellular uptake and subcellular distribution of copper were measured in the coastal marine diatom Thalassiosira weissflogii grown with free Cu ion concentrations (10-14.79−10-9.79 M) that are typical of coastal waters. Intracellular Cu quotas increased 2−3-fold and 4−5-fold per decade increase in free Cu ion concentration over the pCu (pCu = −log [Cu2+]) ranges of 14.79−11.79 and 11.79−9.79, respectively. The trophically available cytoplasmic pool of Cu increased by 2 orders of magnitude in T. weissflogii cells (0.53 × 10-17−75 × 10-17 mol Cu cell-1) grown with 10-14.8−10-9.8 M free Cu. A 2-fold increase in intracellular and cytoplasmic Cu concentrations was observed in response to lowering the free concentration of the potentially antagonistic metal Zn by a factor of 10. However, the percent of intracellular Cu in the cytoplasmic fraction of T. weissflogii (≅ 40%) was relatively constant over the range of cupric ion activities and [Cu2+]:[Zn2+] ratios applied. The assimilation efficiency (AE) of copper i...
Gaussian sample functions and the Hausdorff dimension of level crossings

Let X t be a real Gaussian process with stationary increments, mean 0, σ t 2 =E[(X s+t−X s)2] If σ σ t 2 behaves like t α as t ↺0, 0<α<1, the graph of a.e. sample function will have Hausdorff dimension 2 -α. This leads one to feel that the set of zeros of X t should have Hausdorff dimension 1 -α. This is shown to be true provided the process is stationary and satisfies additional assumptions.
A policy model appraisal paradigm

The application of computer modeling and simulation to the analysis of public policy issues is receiving increased academic and professional attention. While initial efforts by Forrester (1969) and others have provided some insight into the overall feasibility of policy assist models, there still remains a vast amount of unexplored territory. One area of particular concern involves the interface between the model builder and the decisionmaker. Typically, most policy-oriented models have been constructed without considering their actual end use. Perhaps this accounts for the rather high mortality rate experienced among models and model builders. A first step in possibly closing the gap between the two camps calls for a more effective evaluation of the product. The descriptor often used to characterize this phase of the modeling effort is appraisal. Of the five steps in the modeling process, this step is often left out or badly managed. The five-step process consists of conceptualization, development, validation, evaluation, and appraisal. The taxonomy represents a slight variation on the theme as compared to the one given by Garry Brewer and Owen Hall (1973). The main difference in the two schemes reflects the author's emphasis on evaluation (model prediction) and on the need to separate the quantitative verification (validation) of the model from the qualitative assessment (appraisal) of related factors. Consequently, the need for developing and applying sound appraisal criteria cannot be understressed. The purpose of this paper is twofold: first, we will specify the composition of a rudimentary appraisal paradigm. This will take the form of a set of critical questions. Second, the paradigm will be applied to three regional models which will allow us to gain additional insight into these issues and to place this analysis into proper perspective.
Flaws in Evaluations of Social Programs Illustrations From Randomized Controlled Trials

Background: This article describes eight flaws that occur in impact evaluations. Method: The eight flaws are grouped into four categories on how they affect impact estimates: statistical imprecision; biases; failure of impact estimates to measure effects of the planned treatment; and flaws that result from weakening an evaluation design. Each flaw is illustrated with examples from social experiments. Although these illustrations are from randomized controlled trials (RCTs), they can occur in any type of evaluation; we use RCTs to illustrate because people sometimes assume that RCTs might be immune to such problems. A summary table lists the flaws, indicates circumstances under which they occur, notes their potential seriousness, and suggests approaches for minimizing them. Results: Some of the flaws result in minor hurdles, while others cause evaluations to fail—that is, the evaluation is unable to provide a valid test of the hypothesis of interest. The flaws that appear to occur most frequently are response bias resulting from