cssi/SciSciGPT-SciSciNet huggingface dataset:
Theoretical studies of the optical and electronic properties of V, Nb, and Ta

Band structure of V, Nb, and Ta have been calculated by the nonlocal empirical pseudopotential method (EPM). The bands have the same ordering and about the same shapes as previous first-principles results, but show important differences in the locations of the N/sub 1/' and H/sub 12/ states. It is shown that these differences suggest there is considerably less s-p and d-p hybridization of the augmented-plane-wave valence bands compared to the EPM bands. It is further shown that charge distributions with charge maxima located between second nearest neighbors occur when the H/sub 12/ (d/sub x/2/sub hyphen/y-italic2,d/sub z/2) states are more than 2.1 eV below the P/sub 4/ (d/sub x/y,d/sub y/z,d/sub z/x) states. The present charge distributions provide a picture of partially metallic s-p bonding together with additional bonding associated with a ''bilocal covalency'' wherein a nearly nonoverlapping pair of tightly bound atomic d-like charge maxima are aligned between nearest-neighbor atoms. The theoretical reflectivity spectra, based on the direct-transition model (with k-dependent matrix elements), are in reasonable agreement with the data by Weaver et al. The main structure in the optical reflectivity arises from transitions between hybridized s-d bands and hybridized s-p bands near the N symmetry point (e.g., N/sub 1/ ..-->..more » N/sub 1/'). Reflectivities calculated with the nondirect-transition model are in unequivocally poorer agreement with the data than are the direct-transition reflectivities. The calculated densities of states and Fermi surfaces are shown to be in general agreement with available data. The partial densities of s, p, and d states are also presented.« less
A Collaborative Architecture for Multiple Computer Aided Engineering Applications

In this paper, we describe the need, design, and implementation of a Collaborative Architecture. The Collaboration Architecture addresses the need for multiple Computer Aided Engineering applications to exchange data packets directly with each other in an effort to decrease the design cycle time. This architecture incorporates three components in its design, a server, a controller, and multiple members. The members generate and use the data packets. The server maintains and distributes the data packets between the members. The controller component determines which CAE users are generating or using which data sets. The member component has been implemented with three subcomponents, a pusher application, a receiver application, and the CAE application which uses / generates the data packets. For the local member communication, the Collaborative Architecture uses shared memory. For inter-component communication, the architecture uses CORBA. Finally, this paper describes the implementation of two Computer Aided Applications, Dv/Mockup and an Immersive Virtual Design Environment.Copyright © 2002 by ASME
Platform dependent code generation of real-time embedded software

Embedded software constitutes an important part of modern safety-critical systems, such as medical devices. As embedded software is increasingly complex, assuring the safety of such software becomes difficult, especially when the correct function is highly dependent on stringent timing and memory constraints of the implementation platform. Model-based development methodology has garnered attentions as an effective method for creating safety-critical embedded software in a systematic way, so that high-level safety assurance is guaranteed in the final implemented systems. In this methodology, the software system is first modeled using an abstract model, such as timed-automata, which can then be verified using a formal verification tool, such as UPPAAL. Then, code-generation techniques are applied to automatically generate source code from the verified model.
Ammonia emission factors for open-lot dairies: direct measurements and estimation by nitrogen intake.

Abstract Ammonia (NH3) emissions contribute to the formation of secondary particulate matter (PM) 10 μm and under (PM10). Dairies are significant sources of NH3 in the San Joaquin Valley (SJV) of California, where the National Ambient Air Quality Standard for PM10 is frequently exceeded. Detailed descriptions of diets, animal demographics, and production levels were obtained for two commercial open-lot dairies in the SJV and used to compute nitrogen intake for each feeding group (g N day−1). Models derived from nutrition trials with cows, heifers, and calves were used to estimate urea-N excretion from N intake. Air NH3 concentrations were also measured at the same dairies over 1-week periods in February 1999. NH3 fluxes calculated from vertical profiles of concentrations at two or three locations downwind of the dairies were augmented with estimates of flux based on single-height concentrations measured at five or six additional downwind locations to compute NH3 emission rates. NH3 emission potentials, es...
A Possible Case of Gabapentin-Induced Mild Hyperglycemia:

Objective: A possible case of gabapentin-induced mild hyperglycemia is reported. Case Summary: A 63-year-old Caucasian gentleman was treated in a pharmacist-run pharmacotherapy clinic for type 2 diabetes management. His comorbidities included type 2 diabetes mellitus, hypertension, dyslipidemia, coronary artery disease, peripheral vascular disease, Barrett’s esophagus, chronic back pain, and obesity. His medications for these comorbidities were continued throughout his care. The patient had no known drug allergies. After 3 months of pharmacist-managed diabetes management, the patient’s glucose levels had improved and were within the desired range for a majority of the readings. The patient was consulted to the pain clinic for uncontrolled pain and initiated and titrated on gabapentin from 300 mg per day to 600 to 900 mg 3 times per day. Two weeks later, the patient’s glucose levels increased to levels of 150 to 165 mg/dL. The patient’s increasing blood glucose values were treated with NPH insulin, which w...
Comparison of the food of Triphoturus mexicanus and T. nigrescens, two lanternfishes of the Pacific Ocean

Prey (chiefly euphausiids and copepods) eaten by two myctophids (lanternfishes) are compared from incidence in fish stomachs and from abundance in the environment. One lanternfish species, Triphoturus mexicanus, lives in the California Current, and the other, T. nigrescens, lives in the central Pacific Ocean. Although these two environments are very different physically and biologically, the feeding habits of the two lanternfishes are surprisingly similar. Prey biomass is 94% euphausiids, 3% copepods, and 3% other organisms for T. mexicanus and 88% euphausiids, 4.5% copepods, and 7.5% other organisms for T. nigrescens; the difference between the fish species is not significant when tested statistically. The two fishes resemble one another in frequency distributions of ingested copepod individuals, copepod species, euphausiid individuals, and euphausiid species. During a single diurnal feeding period, both fishes eat a variety of copepod species but tend to eat only a single species of euphausiid. T. mexicanus grows to twice the length of T. nigrescens and eats proportionally larger euphausiids; however, both fishes eat copepods having the same median size. The frequencies of euphausiid species in the diets of both fishes differ from the frequencies in the environment. The chief differences between the feeding habits of the two lanternfishes are that T. nigrescens, in comparison to its congener, eats a greater variety of organisms during one diurnal feeding period and captures smaller euphausiids. The feeding patterns for each lanternfish species are consistent over distances of hundreds of kilometers and over many years of sampling.
Analysis of residual amino acid–DNA crosslinks induced in intact cells by nickel and chromium compounds

Chinese hamster ovary cells were incubated with radioactive amino acids, the DNA was isolated by standard proteinase K/phenol/chloroform extraction and residual amino acids complexed to the DNA were examined as an index of metal induced DNA-protein crosslinks. Using this method, both chromate and nickel caused residual histidine and cysteine to be complexed with the DNA isolated from metal-treated cells. In the case of chromate, a number of amino acids were studied and Tyr, Thr and Cys were found to be complexed to DNA at a level (above the untreated control) that was statistically significant. Stability studies indicated that some of the chromate-induced DNA-protein complexes were mediated by direct participation of chromium(III), whereas others that were resistant to dissociation by EDTA and mercaptoethanol did not seem to involve direct chromium(III) participation. A significant portion of the cysteine complexed to DNA by chromate was believed to involve glutathione since treatment of cells with cycloheximide did not decrease chromate-induced cysteine-DNA crosslinks. In the case of nickel, most of the stable DNA-protein crosslinks did not involve direct metal participation and were probably oxidatively mediated by Ni(II)/Ni(III) redox cycling. These findings present new methodology for analysis of DNA-protein crosslinks by examination of residual amino acids associated with the DNA. This method should be highly sensitive and will yield important information about the mechanism of metal-induced DNA-protein crosslinks.
Virial theorem and stability of localized solutions of relativistic classical interacting fields

The properties of classical meson fields interacting with the Dirac field are considered in more detail analytically. We obtain a virial relation between the kinematic and potential energy of the interacting Dirac field. The stability of the classical solutions of the coupled fields constrained to the lowest particle solution of the Dirac equation in three space dimensions is investigated. A criterion allowing the determination of stability of Abelian meson fields in interaction with the Dirac field is given.
The fatty acid composition of fat body and haemolymph lipids in Hyalophora cecropia and its relation to lipid release.

Qualitative and quantitative analyses of the fatty acid composition of fat body and haemolymph lipids have been conducted at two developmental stages in the life of Hyalophora cecropia. The main fatty acids present were C16, C16:1, C18, C18:1, C18:2, and C18:3, with traces of C14, C16:2, C17, and C20. During adult development there is a decline in the relative amount of polyunsaturated fatty acids in the fat body. The relative concentration of C16 increases in the haemolymph lipids during pharate adult development, with a concomitant decrease in C18:3. In vitro experiments revealed that most of the fatty acids released from the fat body into the haemolymph are in the diglyceride fraction, regardless of developmental stage. The use of double-labelled glycerides in release experiments demonstrated a difference in the composition of fat body glycerides, and of haemolymph glycerides derived from the fat body. The data suggest that neutral lipids released from the fat body into the haemolymph are restricted to those with a specific fatty acid composition, or that the fat body contains two different glyceride pools, only one of which communicates with the surrounding medium. A two-compartment theory is presented that favours the latter alternative.
Geochemical and Hf–Nd isotopic constraints on the crustal evolution of Archean rocks from the Minnesota River Valley, USA

Abstract The 3.5–2.6 Ga rocks of the Minnesota River Valley (MRV) provide a unique opportunity to examine rocks that span the now recognized crucial time (3.2–3.0 Ga) on the Earth when Wilson style plate tectonic processes likely started. To elucidate the crustal evolutionary history of these ancient rocks we obtained Hf isotopic compositions by LA-MC-ICPMS from zircon, previously dated by SHRIMP U–Pb methods; whole-rock Nd isotopic compositions by TIMS; and whole-rock major and trace element concentrations. The oldest, ca. 3500 Ma rocks have major and trace element compositions similar to other Archean tonalite–trondhjemite–granodiorite (TTG) suites, which are consistent with derivation from a mafic source. The ca. 3500 Ma Morton and Montevideo gneisses have similar initial ɛ Hf values that range from 1.9 to −2.6 at 3500 Ma, with model ages ranging from 3.83 to 3.64 Ga. The model ages are interpreted as resulting from melting of a source that is >100 Ma older than the ca. 3500 Ma gneisses. Elevated Nb/Ta ratios and large negative Nb, Ta and Ti anomalies suggest that the source may have been eclogite, consistent with melt formation in an overthickened basaltic lithosphere. Younger (3380 Ma), more chemically evolved, intrusions into both the Morton and Montevideo gneisses plot on a closed-system isotopic evolution path (Nd, Hf), indicating that they were in situ melts of the older ca. 3500 Ma rocks. These intrusions contrast with a more mafic 3140 Ma intrusion, which has zircon with more positive ɛ Hf than the closed-system isotopic evolution defined by the older gneisses. The last major event was the emplacement of the 2604 Ma Sacred Heart granite and formation of a garnet-biotite paragneiss. Isotopic values for the Sacred Heart granite show a large juvenile component relative to all other rocks, suggesting it is a mix of juvenile material and recycled Morton or Montevideo gneiss. The transition from closed to open system evolution of rocks in the MRV at 3140 Ma, and continuing at 2600 Ma, is consistent with a proposed global change in continental crust formation and evolution that began at 3.2–3.0 Ga.
Interactions of the Rapsyn RING-H2 Domain with Dystroglycan

Rapsyn, a peripheral membrane protein of skeletal muscle, is necessary for the formation of the highly organized structure of the vertebrate neuromuscular junction. For mice lacking rapsyn, there is a failure of postsynaptic specialization characterized by an absence of nicotinic acetylcholine receptors (nAChRs) and other integral and peripheral membrane proteins such as β-dystroglycan and utrophin. Dystroglycan is necessary for the formation of the mature neuromuscular junction and has been shown to interact directly with rapsyn. Previous studies with rapsyn fragments and mutants, expressed in 293T cells along with nAChRs, establish that the rapsyn tetratricopeptide repeat (TPR) domain is involved in self-association and its coiled-coil domain is necessary for nAChR clustering. The function of the rapsyn RING-H2 domain, which is not necessary for rapsyn self-association or nAChR clustering, is unknown. To further characterize these domains, we have used a yeast two-hybrid assay to test for interactions at the plasma membrane between rapsyn domains and a nAChR β-subunit fragment, the β-dystroglycan cytoplasmic domain, or rapsyn domains. The rapsyn coiled-coil domain interacts with the nAChR β-subunit cytoplasmic domain, but not with itself, other rapsyn domains, or β-dystroglycan. The RING-H2 domain interacts only with the β-dystroglycan cytoplasmic domain. Furthermore, when expressed in 293T cells, a rapsyn construct containing as few as two TPRs and the RING-H2 domain self-associates and clusters dystroglycan, but not nAChRs. These results emphasize the modular character of the rapsyn structural domains.
Limits of sensitivity for the radioimmunodetection of colon cancer by means of a hand held gamma probe

Abstract This study was undertaken to define the limits for the radioimmunodetection of minimal deposits of colorectal cancer cells using a hand held γ probe. 125 I labeled monoclonal antibody 17-1A and its F(ab′) 2 fragments were reacted in vitro with cells of the human colorectal cancer line SW 1116. The limits of sensitivity of the probe were determined by injecting doubling dilutions of 125 I-antibody coated SW 1116 cells ranging from 10 7 to 3.9 × 10 4 subserosally at 2cm intervals into 60 cm segments of freshly obtained autopsy or surgical specimens of human colon. A linear relationship was observed between the number of cells injected and the number of counts obtained with either the probe or well counter. As few as 6.25 × 10 5 125 I-antibody coated cells ( 3 ) were detected under experimentally defined conditions by an earlier version of the probe, and 3.9 × 10 4 coated cells (⪡ 1 mm 3 ) could be detected by the currently available model. Although the count rates were background and allowed the detection of tumor cell deposits that otherwise would not have been discernible by either palpation or external scintigraphy. These findings, in conjunction with ongoing clinical studies, suggest that the hand held γ probe may increase the usefulness of monoclonal antibodies for the radioimmunodetection of cancer.
Changes in lateral differentiation of head posture in the human neonate.

Developmental changes in the relationship between lateral differences in responsiveness and the assumption of asymmetrical head postures were examined. The head turning of 70 infants ranging in age from 0–72 hr was observed following a procedure (maintenance of the head in a midline position) known to reduce or eliminate lateral differences in the infant's response to stimulation. Even following this procedure infants older than 12 hr made significantly more right than left head turns whereas younger infants exhibited no such difference. When lateral differences in sensitivity were not interfered with in 0 to 12 hr old infants (n = 20) they, kile the older infants, made significantly more right than left turns. These results are discussed in terms of possible developmental consequences of a reciprocity between asymmetric head position and lateral differences in sensitivity.
High-precision machining of materials for manufacturing applications using diode-pumped solid state lasers

While developments in the field of diode pumped solid state lasers provide a foundation for precision machining of parts with high accuracy and small feature sizes, this promise can not be realized without considering the interactions of individual processes, systems and material parameters. This paper presents our results on the precision machining of small features in various materials using diode pumped solid state lasers. The machined features are characterized geometrically by using optical inspection techniques and the tolerance data is analyzed statistically. Machining parameters relevant to motion system and tool path compensation are discussed along with their relevance to machined feature geometry. The effect of laser beam polarization on the machined kerf width, kerf surface and feature dimensions is reported.
Wire bond challenges in low‐k devices

Purpose – Ultrafine feature sizes and high‐performance requirements have necessitated the integration of low‐k dielectrics with silicon‐level interconnects. These are mechanically weaker than previous‐generation materials, a fact that has been recognized to be an industry wide issue. The inherently weaker nature of the low‐k dielectric material can pose significant challenges to downstream electronic‐packaging processes and materials. The purpose of this paper is to focus on the wire bonding of gold wires on a Cu/low‐k pad structure.Design/methodology/approach – The paper presents a numerical model description and simulation procedure.Findings – Numerical methods, particularly finite element method based simulations are a good tool to visualize and understand the reasons for success or failure during a bonding process. It enables one to relate the induced stress to the inherent bulk material's strength and interfacial strength. The results from such simulations clearly indicate the high‐stress locations a...
Optical second-harmonic spectroscopy of silicon nanocrystals and step-edges

Optical second-harmonic generation (SHG) is used as a noninvasive probe of the interfaces of Si nanocrystals (Si-NCs) embedded in an $\textrm{SiO}_{2}$ matrix. We verify experimentally that the second-harmonic polarization $\mathbf{P^{(2)}}$ has a quadrupolar form proportional to $(\mathbf{E}\cdot\mathbf{\nabla}) \mathbf{E}$, as proposed in recent models based on a locally noncentrosymmetric dipolar polarization averaged over the spherical NC interface. A two-beam sum-frequency geometry is found to enhanced this polarization dramatically compared to a single-beam SHG geometry, yielding strong signals useful for scanning, spectroscopy and real-time monitoring. Using this two-beam geometry, we have produced non-invasive two dimensional SHG maps with few-micron resolution of 1-micron-thick layers of Si-NCs (3 and 5 nm average diameter) produced by ion implanting Si into $\textrm{SiO}_{2}$. Samples were scanned over a 5mm x 5mm area with two non-collinear, orthogonally polarized, amplified Ti:S laser pulses (80 fs, 810nm, 100 $\mu\textrm{J}$, 1 kHz repetition rate) while detecting the generated SH signal in transmission. The SHG signal is sensitive to chemical modification of the Si/SiO$_2$ interface and to local gradients in nanoparticle density.© (2003) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Production of human alpha consensus interferon in recombinant Escherichia coli

Abstract Using a defined medium and a multiple-phage resistant AM-7 strain of Escherichia coli containing a temperature sensitive multicopy plasmid under lambda promoter control, a fermentation process has been developed for an analog human IFN-α that is a “consensus” of the known IFN-α subtypes. The gene for this interferon was completely synthetic and codon choices were optimized for expression in E. coli. Yields up to 7.6 × 1012 U of IFN-α-Con1 per liter of fermentation broth were achieved. The combination of a tightly regulated expression system and a controlled feeding schedule were fundamental to the attainment of the high expression levels and cell densities required to reach this concentration of interferon.
Initial impact of drug-eluting stents on coronary artery bypass graft surgery.

Background Drug-eluting stents (DES) reduce the incidence of restenosis after percutaneous coronary intervention and have been predicted to decrease the number of patients referred for coronary artery bypass grafting (CABG). The purpose of this study was to determine the impact of DES on the number and characteristics of patients referred for CABG. Methods Drug-eluting stents were introduced at our hospital in April 2003 and reached maturity by June 2003. We compared our isolated CABG patients from the 12 months before the introduction of DES (year 1) with those from the 12 months after full implementation of DES (year 2). Results In year 1, of 4,348 cardiac catheterization patients, 2,144 (49.3%) underwent percutaneous coronary intervention, and 432 (9.9%) had CABG. In year 2, of 3,986 cardiac catheterization patients, 2,027 (50.9%) had percutaneous coronary intervention, and 337 (8.5%) had CABG, representing a 14% reduction in proportion of cardiac catheterization patients referred for CABG ( p = 0.021). Among CABG patients, there was no change in age, prevalence of diabetes, or prevalence of three-vessel disease; however, patients in year 2 were more likely to have left main coronary artery disease (year 1, 36% versus year 2, 44.5%; p p Conclusions The clinical introduction of DES was associated with a modest decrease in the percentage of cardiac catheterization patients referred for CABG. Of those referred for surgery, an increasing proportion had left main coronary artery disease and preserved left ventricular systolic function. Defining the role of DES versus CABG for coronary revascularization will require elucidation of the long-term outcomes of DES compared with CABG.
Glucose counterregulation in advanced type 2 diabetes: effect of β-adrenergic blockade.

OBJECTIVE To examine counterregulatory glucose kinetics and test the hypothesis that β-adrenergic blockade impairs these in patients with type 2 diabetes mellitus (T2DM) and advanced β-failure. RESEARCH DESIGN AND METHODS Nine insulin-requiring T2DM subjects and six matched nondiabetic control subjects were studied. β-Cell function was assessed by the C-peptide response to arginine stimulation. Counterregulatory hormonal responses and glucose kinetics were assessed by hyperinsulinemic euglycemic-hypoglycemic clamps with [3-3H]glucose infusion. T2DM subjects underwent two clamp experiments in a randomized crossover fashion: once with infusion of the β-adrenergic antagonist propranolol and once with infusion of normal saline. RESULTS Compared with the control subjects, T2DM subjects had threefold reduced C-peptide responses to arginine stimulation. During the hypoglycemic clamp, glucagon responses were markedly diminished (16.0 ± 4.2 vs. 48.6 ± 6.0 ng/L, P < 0.05), but other hormonal responses and the decrement in the required exogenous glucose infusion rate (GIR) from the euglycemic clamp were normal (10.4 ± 1.1 vs. 7.8 ± 1.9 µmol · kg−1 · min−1 in control subjects); however, endogenous glucose production (EGP) did not increase (−0.8 ± 1.0 vs. 2.2 ± 0.7 µmol · kg−1 · min−1 in control subjects, P < 0.05), whereas systemic glucose disposal decreased normally. β-Adrenergic blockade in the T2DM subjects increased GIR ∼20% during the euglycemic clamp ( P < 0.01), but neither increased GIR during the hypoglycemic clamp or decreased its decrement from the euglycemic clamp to the hypoglycemic clamp. CONCLUSIONS Overall glucose counterregulation is preserved in advanced T2DM, but the contribution of EGP is diminished. β-Adrenergic blockade may increase insulin sensitivity at normoglycemia but does not impair glucose counterregulation in T2DM patients, even those with advanced β-cell failure.
The numerical solution of some higher-index time-varying semistate systems by difference methods

Necessary and sufficient conditions are given for the solvability of fully implicit index-one and semiexplicit index-two linear time-varying semistate systems of the formA(t)x′+B(t)x=f(t). Using these solvability criteria, we establish the convergence and stability of backward difference formulas (BDF) for solvable semiexplicit index-two systems. In the algebraic variables, these methods exhibit a boundary layer of instability of length 2k, wherek is the order of the method. Finally, we show that the systems considered in this paper belong to a class of problems, solvable by BDF, which strictly contains the systems safely transformable to standard canonical form.
Response of macroinvertebrates to blooms of iron-depositing bacteria

In field measurements and laboratory experiments we assessed the influence of high levels of iron, manganese, and concurrent blooms of iron-depositing bacteria, Leptothrix ochracea, on macroinvertebrates. Macroinvertebrate communities in five of six streams were depauerate inside blooms. Reasons for the decreased abundance vary among taxa, with our experiments demonstrating the importance, for one or more species, of (1) direct toxic effects, and,/or smothering, (2) behavioral avoidance of bacterial-coated substrates, and (3) an inability to use bacteria as food. Three mayfly species showed increased mortality when caged inside the blooms, but five trichopterans and one plecopteran did not. Five invertebrates avoided Leptothrix-coated substrate in choice trials, while three did not. Stenonema fuscum could not ingest Leptothrix, and Neophylax nacatus had reduced growth feeding on it, but Heptagenia umbratica grew equally well on diets of Leptothrix or diatoms. This study demonstrates the important role epilithic organisms play in modifying substrates, and how these changes may act to influence benthic abundance and distribution in streams.
Progress toward molecular characterization of ectoparasite modulation of host immunity

Ectoparasitic arthropods and vector-borne infectious agents are global medical and veterinary public health concerns. Economic impact due to direct effects of infestation and disease transmission are significant. These problems are increased by development of arthropod resistance to insecticides/acaricides; drug resistance of vector-borne pathogens; and, lack of effective vaccines to prevent many of these diseases. There is much to be gained from understanding the complex array of immunological interactions occurring at the arthropod-host-pathogen interface. One application of that knowledge is the development of novel vaccines for the control of both ectoparasitic arthropods and the diseases they transmit. We now realize that blood-feeding arthropods are not simply flying or crawling hypodermic needles and syringes. Ectoparasitic arthropods are not passive partners in their relationships with the immune systems of their hosts. These clever invertebrates produce numerous pharmacologically active molecules that help them migrate through tissues of their hosts or to successfully obtain blood meals. Arthropod parasites stimulate a spectrum of host immune responses that could potentially impair development, reduce feeding success, or kill the ectoparasite. Not unexpectedly, arthropods have developed sophisticated arsenals of countermeasures that modulate or deviate host immune responses. Not only does arthropod modulation of host immunity facilitate survival in tissues or increase the likelihood of obtaining a blood meal, but it is increasingly recognized as a critical factor in pathogen transmission. Those countermeasures to host immune defenses are the topics of this review. Emphasis is placed on our current understanding of the molecular bases of those changes; the molecules responsible for host immunomodulation; contemporary approaches for studying these complex relationships; and, the potential for using this information to develop innovative vaccine-based control strategies.
Carcinoid metastasis to the brain.

BACKGROUND Carcinoid tumors rarely metastasize to the brain. The objectives of the current study were to assess the frequency of brain metastasis from carcinoid tumors, determine correlates of survival, and describe treatment modalities and their outcomes. METHODS Between January 1977 and December 2003, 1633 patients with a carcinoid tumor were registered at The University of Texas M. D. Anderson Cancer Center. Of those, 24 patients (1.5%) had a diagnosis of brain metastasis. The authors collected demographic and clinical data and performed a statistical analysis. RESULTS The median age at the time patients were diagnosed with brain metastasis was 60 years. The metastases were treated with whole-brain radiotherapy (WBRT) alone in 7 patients (29%), and 12 patients (50%) underwent surgical resection, 7 of whom (29%) also received WBRT. The median survival time for the entire cohort after diagnosis of the primary tumor was 2.3 years (95% confidence interval [CI], 0.5–4.1 years), and the median survival time after the diagnosis of brain metastasis was 10.0 months (95% CI, 4.0–16.0 months). The longest median survival observed after the diagnosis of brain metastasis (3.2 years) occurred in patients who underwent resection and received WBRT. In the multivariate analysis, the adjusted rate ratio for comparison of all treatments versus combination of neurosurgical intervention and WBRT was 5.7 (95% CI, 1.3–26.1; P = 0.024). A positive effect of surgery followed by WBRT on the duration of survival was detected in patients with a single metastasis (P = 0.084) as well as in those with multiple metastases (P = 0.018). CONCLUSIONS Prolonged survival was observed in patients < 65 years old as well as in those who underwent surgery and received WBRT in comparison with other treatments. Whenever feasible, neurosurgical resection followed by WBRT seems to be the indicated treatment in patients with brain metastases from carcinoid tumors. Cancer 2004. © 2004 American Cancer Society.
Systems biology and functional genomics approaches for the identification of cellular responses to drug toxicity.

Extensive growth in the field of molecular biology in recent decades has led to the development of new and powerful experimental and computational tools that enable the analysis of complex biological responses to chemical exposure on both a functional and structural genetic level. The ability to profile global responses on a transcriptional level has become a valuable resource in the science of toxicology and attempts are currently being made to further understand toxicity mechanisms by incorporating metabolomics and proteomics approaches. In addition, recent progress in understanding the extent of the genetic diversity within and between species allows us to take a fresh look at research on genetic polymorphisms which may influence an individual’s susceptibility to toxicity. While new technologies have the potential to make a sizeable impact on our understanding of the mechanisms of toxicity, considerable challenges remain to be addressed, especially with regards to the regulatory acceptance and successful integration of omics data. This review highlights recent advancements in the application of functional and structural genomics techniques to chemical hazard identification and characterization, and to the understanding of the inter-individual differences in susceptibility to adverse drug reactions.
Stoichiometry reversal and depth-profiling in the growth of thin oxynitride films with N2O on Si(100) surfaces

Abstract Synchrotron base O 1s and N 1s photoabsorption spectroscopy have been used to determine the composition and thickness of oxynitride films grown in N 2 O on a Si(100) surface. Core-level photoabsorption spectroscopy is shown to be a very sensitive probe capable of measuring surface coverages lower than 0.1 monolayers of N (6.5×10 13 N atoms/cm 2 ). Film composiion was monitored as a function of growth to demonstrate the stoichiometry reversal from primarily N terminated surfaces in thin films to nearly pure SiO 2 in films thicker than ∼ 20 A. A sample with a 60 A oxynitride film was depth-profiled by etching in HF and was shown, via N 1s absorption spectroscopy, to have N segregation within 10 A above the Si/SiO 2 interface.
Opposing cardiac effects of autoantibody activation of beta-adrenergic and M2 muscarinic receptors in cardiac-related diseases

Background Activating autoantibodies to β-adrenergic receptors (AAβ1/2AR) and M2 muscarinic receptors (AAM2R) have been reported in several cardiac diseases and may have pathophysiologic relevance. However, the interactions and relative effects of AAβ1AR, AAβ2AR and AAM2R on contractile function have not been characterized.
Rat DARPP-32: cloning, sequencing, and characterization of the cDNA.

DARPP-32, a substrate for cyclic AMP-dependent protein kinase, is highly enriched in the caudate nucleus. In the present study, the cDNA for rat DARPP-32 was isolated and characterized. When compared to the coding region of bovine DARPP-32 cDNA, there was 86% identity at the nucleotide level, and 84% identity at the amino acid level. The homology in the region previously noted to be similar to phosphatase inhibitor-I remained intact. There were also 3′-untranslated regions that were highly conserved. The DARPP-32 mRNA, which appeared as a doublet, was widely distributed in the central nervous system and was highly enriched in the striatum. Southern blot analysis revealed a simple hybridization pattern, consistent with the presence of a single gene coding for rat DARPP-32. Unilateral destruction of the nigrostriatal dopaminergic pathway by injection of 6-hydroxydopamine (6-OHDA) into the substantia nigra did not alter the striatal steady state levels of DARPP-32 mRNA.
A Compression Framework for Multidimensional Scientific Datasets

Scientific simulations and instruments can generate tremendous amount of data in short time periods. Since the generated data is used for inferring new knowledge, it is important to efficiently store and provide it to the scientific endeavors. Although parallel and distributed systems can help to ease the management of such data, the transmission and storage are still challenging problems. Compression is a popular approach for reducing data transfer overheads and storage requirements. However, effectively supporting compression for scientific simulation data and integrating compression algorithms with simulation applications remain a challenge. In this work, we focus on management of multidimensional scientific datasets using domain specific compression algorithms. We propose a compression framework and methodology in order to maximize the bandwidth and storage utilization. We port our framework into PnetCDF and present our preliminary experimental results.
Importance of plutonium contamination on vegetation surfaces at rocky flats, Colorado

Abstract Vegetation samples collected at Rocky Flats, Colorado were ultrasonically washed to remove attached soil and then analyzed for 239, 240Pu and 238Pu. Mean plutonium concentrations for washed grass, forb and shrub samples were 1.12, 0.61, 0.03 pCi/g, respectively. This compared to a mean of 28.6 pCi/g for unwashed vegetation samples from an earlier study conducted in the same area at Rocky Flats. The mean plutonium isotopic ratio (239,240Pu/238Pu) of 27.2 in vegetation was lower than a ratio of 65.4 in soil, indicating possible differential behavior of the plutonium isotopes in vegetation. Soil attachment to above-ground plant parts ranged from 0.0 to 0.25g soil per g plant. The potential for plutonium contamination on plant parts due to soil attachment was estimated to range from 0.0 to 206 pCi/g. Plutonium on vegetation was concluded to be the major contributor to total plutonium associated with vegetation.
Novel Carbon-Doped TiO2 Nanotube Arrays with High Aspect Ratios for Efficient Solar Water Splitting

The photocatalytic splitting of water into hydrogen and oxygen using solar light is a potentially clean and renewable source for hydrogen fuel.1,2 There has been extensive investigation into metal-oxide semiconductors such as TiO2, WO3, and Fe2O3, which can be used as photoanodes in thin-film form.3-5 Of the materials being developed for photoanodes, TiO2 remains one of the most promising because of its low cost, chemical inertness, and photostability.6 However, the widespread technological use of TiO2 is hindered by its low utilization of solar energy in the visible region. In this study, we report the preparation of vertically grown carbon-doped TiO2 (TiO2-xCx) nanotube arrays with high aspect ratios for maximizing the photocleavage of water under white-light irradiation. The synthesized TiO2-xCx nanotube arrays showed much higher photocurrent densities and more efficient water splitting under visible-light illumination (> 420 nm) than pure TiO2 nanotube arrays. The total photocurrent was more than 20 t...
Soleus stretch reflex in subjects with cerebrovascular accident

Aims The conclusion that circumferential pressure decreases reflex activity in subjects with neuromuscular disorders including cerebrovascular accidents has recently come under scrutiny due to the methods used to analyze its effects. Thus far, studies used to determine circumferential pressure's efficacy on motor neuron reflex excitability have mainly used the H-reflex technique on resting muscle. The purpose of this study was to investigate the effect that circumferential pressure has on the soleus stretch reflex (SSR) when superimposed onto a voluntary ramp movement in patients with cerebrovascular accident (CVA). Methods Thirteen patients with CVA volunteered for this study. SSR's were investigated before, during and after the application of pressure to the calf. Twenty-five SSR's were recorded and averaged for each experimental phase. Peak to peak amplitudes were measured and then normalized for comparisons. Reflex latencies were also measured. Friedman Repeated Measures Analysis of Variance on Ranks ...
The closure factors related to other cognitive processes

Twenty-five group tests, assembled with certain hypotheses concerning the first and second closure factors in mind, were administered to 154 subjects, mostly graduate students. The intercorrelations were analyzed factorially, yielding eight factors that were rotated to an oblique simple structure. The factors were interpreted as: speed of closure, C1; flexibility of closure, C2; verbal closure, C3; word fluency, W; reasoning, R; perceptual speed, P; the first space factor, S1; and speed of handwriting, H. Four second-order factors were tentatively described as analytical ability, synthetic ability, speed of perception, and word fluency. Three of the reasoning tests had their highest loadings on C2 and one on C3, which seems to be evidence that flexibility of closure generalizes in the cognitive domain and is associated with analytical ability.
Glycemic control in diabetes mellitus: have changes in therapy made a difference?

Purpose New methods of measuring and controlling glycemia in diabetes mellitus have been developed and implemented in the past 10 years. We examined whether glycemia, as measured by glycosylated hemoglobin, changed in outpatient insulin-dependent diabetes mellitus (IDDM) and noninsulin-dependent diabetes mellitus (NIDDM) populations between 1985 and 1993 and whether contemporaneous changes in therapy could account for observed changes in glycemia. Patients and methods Outpatients were selected based on having glycated hemoglobin (HbA 1c ) measured in the Massachusetts General Hospital laboratory during March 1985 (IDDM n=94 and NIDDM n=137) or during March 1993 (IDDM n=89 and NIDDM n=118). Chart reviews established demographic and clinical characteristics, including frequency of blood glucose self-monitoring, insulin injections, office visits, and HbA 1c measurements during the year prior to the HbA 1c result. Results Mean HbA 1c level was significantly lower in the 1993 IDDM cohort compared with the 1985 cohort (8.77% ± 1.7% versus 9.47% ± 2.1%, P = 0.014). In the NIDDM cohorts, the difference in mean HbA 1c did not achieve statistical significance (8.35% ± 1.6% in 1993 versus 8.75% ± 2.1% in 1985, P = 0.09); however, when adjusted for differences in NIDDM duration, HbA 1c in the 1993 cohort was significantly lower than that in the 1985 cohort. The largest decrease in HbA 1c in NIDDM was in patients treated with insulin (9.53% ± 2.0% versus 8.54% ± 1.5% in 1985 and 1993, respectively, P = 0.004). Multiple linear regression analyses demonstrated that increased frequency of self-monitoring and of insulin injections were associated with lower HbA 1c in IDDM. Conclusions The level of average glycemia has decreased in IDDM patients over the past 8 years, attributable, at least in part, to an increased frequency of monitoring and of insulin injections. Glycemia decreased in NIDDM, especially in the subset of patients treated with insulin. This temporal shift in glycemic control should have a salutary effect on the development of long-term microvascular and neurologic complications.
Factors associated with fetal growth and body composition as measured by ultrasound.

Abstract Objective: This study seeks to determine which parental demographic and metabolic factors best correlate with fetal growth and body composition as estimated by ultrasound. Study Design: Thirty-one gravid patients had ultrasound estimates of fetal anthropometry in mid-third trimester. These measurements included estimated fetal weight, abdominal subcutaneous fat, and/or thigh subcutaneous fat thickness. Independent variables included diagnosis of gestational diabetes, parental demographic factors, neonatal sex, and late gestation estimates of carbohydrate metabolism. Results: In the multivariate stepwise model the strongest predictor of ultrasound estimated fetal weight was basal hepatic glucose production, followed by late gestation insulin sensitivity (total R 2 = 0.27). The strongest predictors of abdominal subcutaneous fat thickness were weight gain and presence of gestational diabetes (total R 2 = 0.25). Conclusion: Measures of maternal carbohydrate metabolism, rather than fat mass, explain sonographic measurements of fetal weight. We speculate that factors other than maternal carbohydrate metabolism further explain the variances of fetal adiposity. (Am J Obstet Gynecol 2001;185:1416-20.)
Effective and Reduced-Cost Modified Selective Medium for Isolation of Clostridium difficile

Both for epidemiologic studies and for diagnostic testing, there is a need for effective, economical, and readily available selective media for the culture of Clostridium difficile. We have developed a reduced-cost substitute for cycloserine-cefoxitin-fructose agar (CCFA), which is an effective but expensive selective medium for C. difficile. The modified medium, called C. difficile brucella agar (CDBA), includes an enriched brucella base as a substitute for proteose peptone no. 2, and the concentration of sodium taurocholate has been reduced from 0.1% to 0.05%. To compare the sensitivities and selectivities of CDBA and CCFA, cultures for C. difficile were performed using stool samples from patients with C. difficile-associated disease. CDBA was as sensitive as CCFA for the recovery of C. difficile, with a similar frequency of breakthrough growth of stool microflora (25% versus 31%, respectively). A liquid formulation of the modified medium, termed C. difficile brucella broth (CDBB), stimulated rapid germination and outgrowth of C. difficile spores, at a rate comparable to that in cycloserine-cefoxitin-fructose broth. Our results suggest that CDBA and CDBB are sensitive, selective, and reduced-cost media for the recovery of C. difficile from stool samples.
A mobile threat to genome stability: The impact of non-LTR retrotransposons upon the human genome

It is now commonly agreed that the human genome is not the stable entity originally presumed. Deletions, duplications, inversions, and insertions are common, and contribute significantly to genomic structural variations (SVs). Their collective impact generates much of the inter-individual genomic diversity observed among humans. Not only do these variations change the structure of the genome; they may also have functional implications, e.g. altered gene expression. Some SVs have been identified as the cause of genetic disorders, including cancer predisposition. Cancer cells are notorious for their genomic instability, and often show genomic rearrangements at the microscopic and submicroscopic level to which transposable elements (TEs) contribute. Here, we review the role of TEs in genome instability, with particular focus on non-LTR retrotransposons. Currently, three non-LTR retrotransposon families – long interspersed element 1 (L1), SVA (short interspersed element (SINE-R), variable number of tandem repeats (VNTR), and Alu), and Alu (a SINE) elements – mobilize in the human genome, and cause genomic instability through both insertion- and post-insertion-based mutagenesis. Due to the abundance and high sequence identity of TEs, they frequently mislead the homologous recombination repair pathway into non-allelic homologous recombination, causing deletions, duplications, and inversions. While less comprehensively studied, non-LTR retrotransposon insertions and TE-mediated rearrangements are probably more common in cancer cells than in healthy tissue. This may be at least partially attributed to the commonly seen global hypomethylation as well as general epigenetic dysfunction of cancer cells. Where possible, we provide examples that impact cancer predisposition and/or development.