cssi/SciSciGPT-SciSciNet huggingface dataset:
Iteratively decoded space-time trellis codes

Space-time trellis codes (STTC) have been proposed as the constituent codes of turbo codes (D Cui et al., 1999) (W Firmanto et al., 2001). In this article, we propose a similar scheme, the iteratively decoded space-time trellis codes (ISTTC), and derive the performance upper bound on BER. When the STTC are combined with space-time block codes (STTC-STBC), it provides an improved BER over the system with STTC only. Here, we also propose the iteratively decoded STTC-STBC (ISTTC-STBC) to improve both the performance and the rate. It can compensate the reduced transmission rate caused from the iteratively decoded STTC to combine the STBC having more transmitters than the constituent STTC. This paper presents the details of computing the extrinsic information shared between two constituent decoders, design schemes of ISTTC with or without STBC, and their performance results shown via simulation.
Using Data to Persuade: State Your Case and Prove It

The submitted article elaborates on a presentation given at the LAMA Preconference “Got Data, Now What?” on June 25, 2004, in Orlando, Florida.
Using Bounded Degree Spanning Trees in the Design of Efficient Algorihtms on Claw-Free Graphs

Claw-free graphs are graphs that do not have K1,3 as an induced subgraph. Line graphs, a special case of claw-free graphs, are the intersection graphs of edges in simple graphs. We show how to compute efficiently in parallel a binary tree that will be a rooted spanning tree of the claw-free graph. Every binary tree contains at least one edge whose removal partitions the tree into two subtrees of nearly equal cardinality, and this separator can be found efficiently in parallel. We solve problems on claw-free graphs by a divide-and-conquer strategy. The advantage of our partition is that the vertices in each set induce a connected subgraph. The problems are solved for the two subgraphs, and then the results are combined to get a solution for the entire graph.
Tourism planning and the public/private sector relationship.

This paper discusses the importance and complexities of the public/private sector relationship for tourism planning in the 1990s. Conceptual frameworks are employed to explain the emerging vicious circle of tourism planning as a basis for further research in this area.
A switched capacitor subranging A/D conversion technique

A capacitor ratio independent subranging analog-to-digital (A/D) conversion technique is proposed. Conversion is performed by using high resolution coarse and fine reference voltage levels. The digital-to-analog (D/A) converter in the structure generates coarse and fine reference voltage levels for subranging A/D conversion. These reference voltages are stored in a capacitor array which is refreshed periodically. High-resolution A/D conversion is achieved by comparing the input voltage with these voltage levels. The proposed subranging A/D conversion technique also uses a parallel structure for analog subtraction. Improved resolution is obtained without increasing the number of conversion steps. Simulation of the algorithm in PSPICE shows results that are consistent with theoretical analysis. >
Reduction of baroreceptor-related sympathetic discharge during NMDA receptor antagonism

N-Methyl-D-aspartate receptor blockade by MK-801 produced changes in the baroreceptor related component of pre-ganglionic sympathetic discharges in kittens. Spectral analyses carried out on sympathetic and blood pressure signals demonstrated: (a) a marked reduction in amplitude of peaks, 2-6 Hz range, in sympathetic autopower spectra and (b) a substantial decrease of coherence between sympathetic and blood pressure signals in the 2-6 Hz range.
The existence of molecular water pumps in the nervous system: a review of the evidence

Recently, the presence if both influx and efflux molecular water pumps (MWP's) in vertebrate cells has been reported. These appear to use a common mechanism; the intercompartmental cotransport of water uphill against a gradient as a hydrophylic osmolyte is transported down its own gradient, in a regulated fashion, by a membrane spanning cotransporter protein. In each case, the dwell time of the transported osmolyte is short in that it is metabolically converted and its products either eliminated or recycled, thereby maintaining the required high intercompartmental gradient. An influx water pump osmolyte has been identified as a sodium-glucose complex, and an efflux water pump osmolyte as N-acetylhistidine. These osmolytes may also be archetypal representatives of many other osmolytes with similar functions in a variety of cells. When recycled, the osmolyte metabolites appear to be dewatered during high affinity binding that is associated with their active transport back across the membrane prior to intracellular resynthesis of the osmolyte. Since these cyclical systems result in the pumping of water, they also appear to create a previously unrecognized motive force which results in the establishment of unidirectional transcellular water flows between apical and basolateral cell membranes. As neurons represent highly specialized forms of animal cells, and cells which are also extremely sensitive to changes in osmotic pressure, the presence of these water pumps in the CNS could be significant. There would be connotations with regard to how neurons regulate water balance and transaxonal flow as well as to how these factors affect the integrated function of the nervous system. In this article, evidence of the presence of MWP's in the nervous system, and how they might relate to aspects of both normal and abnormal brain function is reviewed.
Manipulation of early embryonic development

Abstract Over the last 15 years, significant advances in our understanding of mechanisms that regulate development of the mammalian embryo have been achieved. Much of this information has been gained as a result of elegant technologies that have been developed to precisely manipulate the embryo in vitro. These powerful procedures, while often inefficient in producing live offspring with altered phenotypes, have nonetheless allowed the investigator and practitioner unique opportunities to design and test novel experiments that have dramatically increased our understanding of mechanisms that regulate embryonic development of livestock. Of these technologies to date, embryo transfer has proven to be most valuable commercially with respect to the cattle industry. Clearly, broad application of technologies to genetically engineer livestock will rely heavily on the ability to improve the cost and production efficiencies of these procedures. The importance of developing predictive, non-invasive assays that correlate directly with the developmental competence, or viability, of domestic species embryos is presented. The application of such non-subjective selection procedures will likely accelerate the integration, and enhance the commercial value of embryo manipulation technologies in the future.
Membrane Fusion Mediated by Baculovirus gp64 Involves Assembly of Stable gp64 Trimers into Multiprotein Aggregates

The baculovirus fusogenic activity depends on the low pH conformation of virally-encoded trimeric glycoprotein, gp64. We used two experimental approaches to investigate whether monomers, trimers, and/or higher order oligomers are functionally involved in gp64 fusion machine. First, dithiothreitol (DTT)- based reduction of intersubunit disulfides was found to reversibly inhibit fusion, as assayed by fluorescent probe redistribution between gp64-expressing and target cells (i.e., erythrocytes or Sf9 cells). This inhibition correlates with disappearance of gp64 trimers and appearance of dimers and monomers in SDS-PAGE. Thus, stable (i.e., with intact intersubunit disulfides) gp64 trimers, rather than independent monomers, drive fusion. Second, we established that merger of membranes is preceded by formation of large (greater than 2 MDa), short-lived gp64 complexes. These complexes were stabilized by cell-surface cross-linking and characterized by glycerol density gradient ultracentrifugation. The basic structural unit of the complexes is stable gp64 trimer. Although DTT-destabilized trimers were still capable of assuming the low pH conformation, they failed to form multimeric complexes. The fact that formation of these complexes correlated with fusion in timing, and was dependent on (a) low pH application, (b) stable gp64 trimers, and (c) cell-cell contacts, suggests that such multimeric complexes represent a fusion machine.
Ostertagia, Haemonchus, Cooperia, and Oesophagostomum: Construction and characterization of genus-specific DNA probes to differentiate important parasites of cattle

Abstract Partial genomic DNA libraries for four common cattle parasites, Ostertagia ostertagi (Oo), Haemonchus placei (Hp), Cooperia oncophora (Co), and Oesophagostomum radiatum (Or), were generated and differentially screened with radiolabeled homologous and heterologous genomic DNA. Clones were identified from each parasite species which did not cross react with DNA from the heterologous genera by Southern blot or slot-blot analyses. Four clones, pOo2, pHp2.l, pCo2, and pOr14 were chosen for further examination. Genomic DNA from other species within the genera were screened with the cloned segments, and the clones were shown to be genus specific. The cloned fragments ranged in size from 195 to 669 base pairs and were approximately 50% in AT content. The cloned segments, pOo2 and pCo2, were approximately equally represented within their parasite genomes at 0.40 and 0.62%, respectively, whereas pHp2.1 and pOr14 were significantly higher at 1.61 and 3.39%, respectively. Sequence analysis demonstrated that pOr14 contained three 180-base pair tandemly repeated units with minor sequence variability between the repeats. Results presented here suggest that these sequences can detect as few as 25 eggs, and hence, may be used as diagnostic probes for the antemortem differentiation of trichostrongyle infections in cattle.
Dickson Polynomials and Irreducible Polynomials Over Finite Fields

In this paper we establish necessary and sufficient conditions for Dn(x, a) + b to be irreducible over Fq, where a, b ∈ Fq, the finite field Fq of order q, and Dn(x, a) is the Dickson polynomial of degree n with parameter a ∈ Fq. As a consequence we construct several families of irreducible polynomials of arbitrarily high degrees. In addition we show that the following conjecture of Chowla and Zassenhaus from 1968 is false for Dickson polynomials: if ƒ(x) has integral coefficients and has degree at least two, and p is a sufficiently large prime for which ƒ(x) does not permute Fp, then there is an element c ∈ Fp so that ƒ(x) + c is irreducible over Fp. We also show that the minimal polynomials of elements which generate one type of optimal normal bases can be derived from Dickson polynomials.
Activity of the yeast Tat2p tryptophan permease is sensitive to the anti-tumor agent 4-phenylbutyrate.

4-Phenylbutyrate (PB) induces differentiation and is being intensively studied as a treatment for brain, prostate, breast, and hematopoietic cancer. While many different primary targets for PB have been proposed, the mechanism by which it causes cellular differentiation remains unknown. To identify the primary cellular target, we investigated its effects on Saccharomyces cerevisiae and showed that it inhibits tryptophan transport. We show here that PB and sorbic acid induce an ubiquitin-dependent turnover of the tryptophan permease Tat2p. However, the inhibition of transport is not a consequence of the loss of Tat2p, since it also occurs when turnover is prevented by deleting the Tat2p ubiquitination sites. When we tested the effects of PB and other growth inhibitory agents on the growth of amino acid auxotrophs, we found that several auxotrophs are hypersensitive to a number of chemically unrelated agents, including PB and some, but not all, weak acids; and this sensitivity is due to the inhibition of amino acid transport. For the inhibitory weak acids, inhibition is not confined to aromatic amino acid auxotrophs, nor is it a general weak acid stress response, since the degree of inhibition is independent of weak acid hydrophobicity and pKa. Our results show that diverse agents affect the activity of the Tat2p permease rather than its stability and suggest the hypothesis that the anti-neoplastic action of PB is due to a decrease in the activity of surface receptors or other membrane proteins needed to maintain the transformed state.
5-Hydroxytryptamine in mammalian thyroid gland.

Schilddrusen von Ratten und Schafen enthalten relativ grosse Mengen von 5-Hydroxytryptamin. In der Thyreoidea von Hunden wird dieser Stoff nur in einer hundertmal kleineren Konzentration vorgefunden. Weiter wird gezeigt, dass in der Rattenthyreoidea eine nicht identifizierte, acetonlosliche Substanz vorhanden ist, welche Uteruskontraktionen auszulosen vermag.
Molecular dynamics simulation study of the melting of Pd-Pt nanoclusters

Bimetallic nanoclusters are of interest because of their utility in catalysis and sensors. The thermal characteristics of bimetallic Pt-Pd nanoclusters of different sizes and compositions were investigated through molecular dynamics simulations using quantum Sutton-Chen (QSC) many-body potentials. Monte Carlo simulations employing the bond order simulation model were used to generate minimum energy configurations, which were utilized as the starting point for molecular dynamics simulations. The calculated initial configurations of the Pt-Pd system consisted of surface segregated Pd atoms and a Pt-rich core. Melting characteristics were studied by following the changes in potential energy and heat capacity as functions of temperature. Structural changes accompanying the thermal evolution were studied by the bond order parameter method. The Pt-Pd clusters exhibited a two-stage melting: surface melting of the external Pd atoms followed by homogeneous melting of the Pt core. These transitions were found to depend on the composition and size of the nanocluster. Melting temperatures of the nanoclusters were found to be much lower than those of bulk Pt and Pd. Bulk melting temperatures of Pd and Pt simulated using periodic boundary conditions compare well with experimental values, thus providing justification for the use of QSC potentials in these simulations. Deformation parameters were calculated to characterize the structural evolution resulting from diffusion of Pd and Pt atoms. The results indicate that in Pd-Pt clusters, Pd atoms prefer to remain at the surface even after melting. In addition, Pt also tends to diffuse to the surface after melting due to reduction of its surface energy with temperature. This mixing pattern is different from those reported in some of the earlier studies on melting of bimetallics.
Cognitive deficit and the aging brain: a behavioral analysis.

Cross-sectional comparisons were performed between young and old subject groups matched for socioeconomic status (SES) and vocabulary score on Raven's Colored Progressive Matrices, an incomplete figure recognition test (IFR), and a measure of auditory letter span (ALS). The elderly group's performance was relatively inferior on all three measures, but least so on the ALS, for which they were able to use their overlearned knowledge of English spelling patterns. Deficit on the unfamiliar “right-hemispheric” IFR was fully accounted for by deficit on Matrices. This loss on a test of cerebrally localizable process (IFR) and on a non-localizable test presumably indicative of diffuse neuronal depletion (Matrices) were comparable in extent, suggesting that basically homogeneous cerebral atrophy in aging equally affects focally and diffusely organized cerebral processes. Where previously acquired “structure” can be invoked (ALS), test performance is relatively preserved.
The Study of β‐Lactoglobulin Adsorption on Polyethersulfone Thin Film Surface Using QCM‐D and AFM

The adsorption process of beta-lactoglobulin on the polyethersulfone-coated surface has been investigated using a quartz crystal microbalance with dissipation monitoring (QCM-D), which allowed simultaneous measurements of frequency and energy dissipation changes caused by the formation of a beta-lactoglobulin layer during the protein adsorption process. The results showed that the protein adsorption on the spin-coated polyethersulfone surface consisted of reversible and irreversible adsorption processes, and the irreversible adsorption was the principal factor to cause the permanent protein adsorption onto the polymer surface. The amount of irreversible adsorption of beta-lactoglobulin increased significantly, from 380.5 +/- 23.2 to 745.5 +/- 29.7 ng/cm2, when the concentration of beta-lactoglobulin solution varied from 0.1% to 2.0% (w/v). The pH also played an important role in the protein adsorption. When the pH of the solution varied from 7.0 to 3.0, the amount of irreversible adsorption of beta-lactoglobulin increased from 427.1 +/- 80.7 to 741.2 +/- 135.1 ng/cm2.
The benzene metabolite, hydroquinone, selectively induces 5q31- and -7 in human CD34+CD19- bone marrow cells.

Abstract Objective Chronic exposure to high concentrations of benzene is associated with an increased incidence of myelodysplastic syndrome and acute myelogenous leukemia. Acute myelogenous leukemia developing in patients treated with alkylating agents for other cancers or occupationally exposed to benzene exhibit a pattern of cytogenetic aberrations predominantly involving loss of all or part of chromosomes 5 and/or 7. In contrast, trisomy 8 is observed equally in both de novo and secondary acute myelogenous leukemia. Studies using peripheral lymphocytes or lymphoblastoid cell lines have observed dose-dependent loss of chromosomes 5, 7, and 8 following treatment with the benzene metabolite, hydroquinone. The purpose of this study was to determine the dose response and specificity of hydroquinone-induced aberrations on chromosomes 5, 7, and 8 using human CD34 + CD19 − bone marrow cells. Materials and Methods Fluorescence in situ hybridization analysis was performed on CD34 + CD19 − bone marrow cells using the locus-specific probes, 5q31, 5p15.2, and centromeric probes specific for human chromosomes 7 and 8 following hydroquinone exposure. Results Hydroquinone exposure results in −7, selective deletion of 5q31 but not chromosome 5 and no loss or gain of chromosome 8 in human CD34 + CD19 − cells. Conclusion CD34 + bone marrow cells are more susceptible and show a different pattern of cytogenetic aberrations as a result of hydroquinone exposure compared to lymphocytes. CD34 + bone marrow cells exhibit unique susceptibility to the development of specific chromosome aberrations that have been identified as the earliest structural changes occurring in the development of secondary myelodysplastic syndrome and acute myelogenous leukemia.
Fatigue life estimation of existing bridges under vehicle and non-stationary hurricane wind

Abstract During hurricane events, additional damages to existing bridge details might be accumulated from the large stress cycles generated by the non-stationary wind and dynamic vehicle loads. The environmental corrosion could also reduce the structural fatigue strength. Based on the non-stationary wind field modeling techniques and the vehicle–bridge–wind dynamic analysis framework, this paper initiates a fatigue damage assessment of existing bridges with corrosion under vehicle and non-stationary extreme hurricane wind loads. The non-stationary hurricane wind is simulated as a summation of time-varying mean and fluctuating non-stationary components with a time-varying spectrum. Dynamic stress histories are obtained by solving the vehicle–bridge–wind dynamic system. The rain flow counting method is used to obtain the stress ranges and numbers of stress cycles. The corrosion induced fatigue strength degradation is included in the analysis. Numerical examples of an existing long span bridge under simulated non-stationary hurricane winds and vehicles are presented to demonstrate the effects of the dynamic loads and corrosions on the fatigue life estimation of existing bridges.
Interactions among drinking identity, gender and decisional balance in predicting alcohol use and problems among college students.

Background The aim of the present study was to test promising constructs (decisional balance and drinking identity) and their interaction with gender as predictors of risky college drinking. We expected that, consistent with previous work, drinking identity would be positively associated with alcohol consumption and problems. We further expected that drinking identity would be more strongly related to outcomes among individuals scoring low in decisional balance. Additionally, we expect the relationship between drinking identity and alcohol behavior to vary as a function of decisional balance.
George Bushe, author of the first American book on proctology.

This report reviews the life of George Macartney Bushe and the first American book on anorectal diseases which he wrote. Bushe'sTreatise, which was based on his literary and practical knowledge, gained the deserved recognition of American and European physicians for many decades.
Effect of adrenalectomy on ethanol-associated changes in lymphocyte cell numbers and subpopulations in thymus, spleen, and gut-associated lymphoid tissues.

Abstract Consumption of ethanol (ETOH) by experimental animals and human beings is associated with elevated serum levels of corticosteroids. One of the most robust findings associated with ETOH consumption is a loss of lymphocytes from thymus and spleen, as well as from peripheral lymphoid organs to include mesenteric lymph nodes and Peyer’s patches, which are lymphoid organs associated with the gastrointestinal tract. To study the role of corticosteroids in loss of cells from thymus, spleen, and gut-associated lymphoid organs, adrenalectomized (ADX) or intact C57Bl/6 mice were fed a liquid diet containing ETOH (to supply 36% of calories as ETOH) or an isocaloric control diet with a pair-feeding protocol. Loss of lymphocytes from all lymphoid organs was associated closely with serum corticosterone levels in both ETOH-fed and pair-fed groups. ETOH-fed ADX animals showed much less cell loss than did ETOH-fed intact animals. However, there was still an association between ETOH consumption and cell loss when cell loss in ETOH-fed ADX animals was compared with that in ADX pair-fed and ADX chow-fed groups. In both intact and ADX animals ETOH consumption was associated with a loss of immature (CD4 + and CD8 + ) cells from the thymus. These data lead to the suggestion that corticosteroids are responsible for most of the cell loss from thymus, spleen, mesenteric lymph nodes, and Peyer’s patches in association with ETOH consumption. Some cell loss, however, is independent of corticosteroids. The data presented here also support the suggestion that cell loss from lymphoid organs could be the result of nutritional factors.
Seismic anisotropy due to preferred mineral orientation observed in shallow crustal rocks in southern Alaska

Laboratory velocity measurements and structural field relations explain the observation of a significant seismic anisotropy within highly foliated rocks in southern Alaska. The orientation of the principal compressive stress indicates that this anisotropy is not related to extensive dilatancy, but can be satisfactorily explained by the foliation of the metasedimentary rocks. Laboratory measurements indicate a significant anisotropy within these rocks even at pressures well above those thought to close microcracks. These observations document that anisotropy related to preferred mineral orientation may be widespread in continental rocks. Thus, pervasive foliation can play a more important role in causing anisotropy than dilatancy, and inferences of principal stress orientations solely from anisotropy may be erroneous.
Intravenous home hydration in pediatric patients following adenotonsillectomy

Objective: To determine the feasibility, safety and efficacy of intravenous home hydration for pediatric postoperative adenotonsillectomy patients. Method: Nonrandomized control trial of two groups of pediatric patients following adenotonsillectomy—one with (H) and one without postoperative home intravenous hydration (WH). Setting: A tertiary care, university-based children's hospital. Intervention: Administration of 25 cm3 kg−1 of Lactated Ringer's solution once a day for 3 days via an intravenous catheter. Results: Three of 22 patients in the (WH) group and none of the 25 patients in the (H) group required an emergency room admission for dehydration. Difficulty swallowing and activity level were found to be statistically different based on χ2-analysis (P<0.05). The hydration group (H) had a greater swallowing difficulty score (1.4) compared with the nonhydration (WH) group (0.06). The (H) group had a lower activity score (0.2) compared with the (WH) group. Other parameters such as duration of pain, the severity of pain, days until oral feeds could be taken without difficulty, degree of dysphagia, degree of neck, throat, tongue and ear pain were not statistically different between the two groups based on χ2-analysis (P<0.05). There were no complications associated with intravenous hydration. Conclusion: Increased efficacy from intravenous hydration was not shown based on a number of parameters. Selected patients with a high likelihood to develop dehydration or medically intractable emesis may benefit from intravenous hydration and may avoid emergency room or hospital admission. Bolus infusions of 25 cm3 kg−1 of Lactated Ringer's solution by home care nursing can be implemented safely in pediatric patients.
Quantitative analysis of the plain radiographic appearance of central chondrosarcoma of bone.

Rationale and objective To quantitate radiographic features that distinguish the plain radiographic appearance of central chondrosarcoma from other solitary bone lesions. Materials and methods Seven hundred nine cases of focal bone lesions, including 37 central chondrosarcomas, were analyzed according to demographic, anatomic, and plain radiographic features. Vector analysis of groups of features was performed to determine those that are most sensitive and specific for the appearance of central chondrosarcoma in contrast with other lesions in the data base. Results The most specific appearance of long bone central chondrosarcomas was a lesion within the medullary cavity with geographic destruction, containing calcified matrix and a diameter greater than 5.9 cm, or arising within the proximal metaphysis or diaphysis. These features all are present in 9 (39%) of the 23 long bone central chondrosarcomas and in less than 1% of other lesions. In flat bone lesions, calcified matrix and either geographic bone destruction, medullary location, or enlargement of the host bone were 100% specific but of low sensitivity, identifying 7 (50%), 7 (50%), and 6 (41%) of the 14 flat bone chondrosarcomas, respectively. Inclusion of calcified matrix in the description is essential to make the criteria specific but excludes several of the most aggressive long bone chondrosarcomas. The vector analysis-generated differential diagnosis include osteosarcoma, fibrous dysplasia, unicameral bone cysts, aneurysmal bone cysts, malignant fibrous histiocytoma, and Ewing sarcoma. Conclusions A relatively specific set of radiographic features can be defined to assist in plain film diagnosis of central chondrosarcoma, but there are many chondrosarcomas that fall outside these parameters. Thus, while not sufficiently sensitive to allow accurate plain film diagnosis in all cases, these criteria serve as an improved foundation for differential diagnosis.
Interaction between plasma potassium and epinephrine in coronary thrombosis in dogs.

BACKGROUNDBoth plasma potassium ([K]) and epinephrine concentrations have been known to increase during exercise and decrease rapidly shortly after exercise; in addition, it is also known that exercise can promote coronary thrombosis in human and animal subjects. Many studies have shown that epinephrine has a stimulatory effect on coronary thrombosis; however, little information is available concerning the effect of raising plasma [K] on coronary thrombosis. The present study was designed to investigate the effect of raising plasma [K] and its interaction with epinephrine infusion on coronary thrombosis.METHODS AND RESULTSA canine model of coronary thrombosis was used, and the frequency of cyclic blood flow reductions (CFRs) resulting from thrombus formation in the circumflex artery was analyzed in the study. By acutely raising plasma [K] to approximately 6.0 mEq/L, the frequency of CFRs was reduced from 8.0 +/- 0.6 to 3.7 +/- 1.0 in 40 minutes (P < .01). Epinephrine infusion (0.5 microgram.kg-1 x min-1) ...
The effect of cyclophosphamide on suppressor cells in guinea pigs

Abstract Treatment of guinea pigs with cyclophosphamide is known to deplete lymphoid tissues, although its effect on delayed hypersensitivity is varied. Experiments were conducted in which suppressor cell activity was studied in vitro in association with histological changes in different lymphoid tissues. An inverse relationship existed between the number of thymic lymphoid cells and thymic suppressor cell activity. In the spleens, suppressor cell activity was also observed initially, but its course could not be followed because of increased myelopoietic action.
Intravascular Glucose/Lactate Sensors Prepared with Nitric Oxide Releasing Poly(lactide-co-glycolide)-Based Coatings for Enhanced Biocompatibility

Intravenous amperometric needle-type enzymatic glucose/lactate sensors intended for continuous monitoring are prepared with a novel nitric oxide (NO) releasing layer to improve device hemocompatibility. To create an underlying NO release coating, the sensors with immobilized enzymes (either glucose oxidase or lactate oxidase) are prepared with a thin layer of poly(lactide-co-glycolide) (PLGA) loaded with lipophilic diazeniumdiolate species that slowly release NO via a proton driven reaction. An outer thin layer (ca. 30 μm) of PurSil (polyurethane/dimethylsiloxane copolymer) limits the flux of glucose and lactate to the inner layer of enzyme, to provide the desired linear amperometric response. A 30 μm coating of PLGA containing 33 wt% of the appropriate NO donor (N-diazeniumdiolated dibutylhexanediamine, DBHD/N₂O₂) can release NO at a physiologically relevant rate > 1 × 10⁻¹⁰mol min⁻¹ cm⁻² for at least 7 days without influencing the analytical performance of the glucose/lactate sensors. In vitro, the sensors exhibit relatively stable amperometric response over a one-week period with high selectivity over interferences (e.g., ascorbic acid) required for blood monitoring applications. Glucose sensors implanted in the veins of rabbits for 8h exhibit significantly enhanced hemocompatibility for the NO release sensors vs. corresponding controls (without NO release in same animals), with greatly reduced thrombus formation on their surfaces. Further, the analytical performance of the NO release glucose sensors are superior to controls placed in the veins of the same animals, with a greater accuracy in measuring blood glucose levels as evaluated using a Clarke error grid type analysis.
The application of thin-layer chromatography and phosphorimetry for the rapid determination of nicotine, nornicotine, and anabasine in tobacco

Abstract Tobacco is ground and extracted with chloroform, and thin-layer chromatography is used to separate the 3 major tobacco alkaloids—nicotine, nornicotine and anabasine. Each of the alkaloids is quantitatively removed by scraping the spot into a container and dissolving in ethanol-sulfuric acid. A small volume of the ethanol solution is then measured phosphorimetrically. Excellent recoveries of each of the tobacco alkaloids were obtained; the relative standard deviation of analysis was 6% or less for all analyses. The total time for analysis of the 3 alkaloids was less than 90 min. This method is considerably faster and more accurate than previous methods.
Io's Escaping Atmosphere: Continuing the Legacy of Surprise

The discovery of Io and her fellow Medicean Stars clearly altered the course of science as a whole. It is equally clear that the discovery of Io's tidal heating has altered the course of planetary science. One of the most directly observable consequences of Io's tidal heating is the prodigious escape of a ton per second of volcanically-supplied gases. I will review how studies of Io's escaping atmosphere since 1972 have advanced our deep understanding of Io itself, and helped formulate our perspective on planetary evolution in our solar system and beyond.
Neurobehavioral Deficits in db/db Diabetic Mice

Recent clinical studies indicate neurobehavioral disturbances in type-2 diabetics. However, there is paucity of preclinical research to support this concept. The validity of db/db mouse as an animal model to study type-2 diabetes and related complications is known. The present study was designed to investigate comprehensively the db/db mouse behavior as preclinical evidence of type-2 diabetes related major neurobehavioral complications. We tested juvenile (5-6weeks) and adult (10-11weeks) db/db mice for behavioral depression in forced swim test (FST), psychosis-like symptoms using pre-pulse inhibition (PPI) test, anxiety behavior employing elevated plus maze (EPM) test, locomotor behavior and thigmotaxis using open field test and working memory deficits in Y-maze test. Both juvenile and adult group db/db mice displayed behavioral despair with increased immobility time in FST. There was an age-dependent progression of psychosis-like symptoms with disrupted PPI in adult db/db mice. In the EPM test, db/db mice were less anxious as observed by increased percent open arms time and entries. They were also hypo-locomotive as evident by a decrease in their basic and fine movements. There was no impairment of working memory in the Y-maze test in db/db mice. This is the first report of depression, psychosis-like symptoms and anxiolytic behavior of db/db mouse strain. It is tempting to speculate that this mouse strain can serve as useful preclinical model to study type-2 diabetes related neurobehavioral complications.
Friendships in preschool children with autism spectrum disorder: What holds them back, child characteristics or teacher behavior?

Children begin to show preferences for specific playmates as early as the first 2 years of life. Children with autism spectrum disorder have difficulty making friends, even in elementary and middle school. However, very little is known about earlier friendships in children with autism such as preschool friendships. This study examined friendships in preschool children with autism and explored how joint attention contributes to these friendships in mainstream settings. A secondary aim was to determine the extent to which teachers used strategies to facilitate friendship development. The participants were 31 mainstreamed preschool children (ages 2–5 years) with autism spectrum disorder. School observations were conducted individually to capture participants’ interactions with peers and adults during free play. The results indicated that 20% of the participants had friendships at school. Children with friends were more likely than children without friends to be jointly engaged with their peers during free pl...
Effects of fiberoptic bronchoscopy on intracranial pressure in patients with brain injury: a prospective clinical study.

Background Fiberoptic bronchoscopy (FB) plays an important role in making the diagnosis of nosocomial pneumonia and resolving lobar atelectasis in critically injured trauma patients. It has been shown to be a safe procedure with only occasional complications. However, in patients with head injuries, FB can lead to intracranial hypertension. Sustained increases in intracranial pressure (ICP) leads to poor outcome in these patients. Because of this, a prospective study was done not only to assess the effect of FB on ICP and cerebral perfusion pressure (CPP) in patients with brain injuries, but also to identify a regimen of sedation and anesthesia that could prevent significant increases in ICP during FB. Methods Twenty-six FB were performed in 23 patients with ICP monitors or ICP monitors and ventriculostomy drains in place for Glasgow Coma Scale score 10 mm Hg, also received a nebulizer treatment of 3 mL of 4% lidocaine before FB. All patients were preoxygenated with FIO2 = 1.0 for 10 minutes. Intracranial pressure, mean arterial pressure, and CPP were monitored continuously throughout the procedure. These same variables were also recorded at baseline and at 2-minute intervals during the procedure. The time to return to baseline ICP was also recorded. Results The mean ICP at baseline (immediately before FB) was 12.6 mm Hg. After introduction of the bronchoscope, the ICP rapidly increased in 21 procedures (81%) and the mean highest ICP was 38.0 mm Hg. There was also a concomitant increase in mean arterial pressure such that there was no substantial change in CPP. The mean lowest CPP was 73.1 mm Hg. The average time for return of ICP to baseline was 13.9 minutes. In the subgroup of patients with ICP > 10, attempting to blunt the tracheal stimulation by anesthetizing the trachea with 4% nebulized lidocaine did not seem to be successful. The mean highest ICP in this subgroup was 41.8 mm Hg. The CPP changed in a similar manner, as the mean lowest CPP was 74.0 mm Hg. The mean time to return to baseline was 12.5 minutes. No patient had acute neurologic deterioration secondary to FB. Conclusions Although FB is an important procedure in the pulmonary care of head injured patients, it produces substantial, but transient, increases in ICP and should be used with caution in patients with diminished cranial compliance. Sedation, analgesia, paralysis, and topical tracheal anesthesia did not completely prevent the rise in ICP. Although no acute deterioration in condition occurred, secondary brain injury caused by localized cerebral ischemia is certainly possible. Because of the substantial increases in ICP, herniation may be precipitated in an occasional patient. Further study is needed to identify a regimen that will confer protection.
Maximum Likelihood and Minimum x 2 Estimates of the Logistic Function

• The Mayo Foundation is a part of the Graduate School of the Univereity of Minnesota. 1 Unless otherwise specified, the x' referred to is the classic x' of Pearson. Appendix Note 1 should be read for the definition of the minimum x' estimate. • It is worth noting that in deriving the x' estimate, we needed only to be able to write the expectation PN, but to derive the maximum likelihood estimate, we needed to asaume that the ob... rved :II ie
Microstructural integrity of early- versus late-myelinating white matter tracts in medial temporal lobe epilepsy.

Summary Purpose Patients with medial temporal lobe epilepsy (MTLE) exhibit structural brain damage involving gray matter (GM) and white matter (WM). The mechanisms underlying tissue loss in MTLE are unclear and may be associated with a combination of seizure excitotoxicity and WM vulnerability. The goal of this study was to investigate whether late-myelinating WM tracts are more vulnerable to injury in MTLE compared with early myelinating tracts. Methods Diffusional kurtosis imaging scans were obtained from 25 patients with MTLE and from 36 matched healthy controls. Diffusion measures from regions of interest (ROIs) for both late- and early myelinating WM tracts were analyzed. Regional Z-scores were computed with respect to normal controls to compare WM in early myelinating tracts versus late-myelinating tracts. Key Findings We observed that late-myelinating tracts exhibited a larger decrease in mean, axial, and radial kurtosis compared with early myelinating tracts. We also observed that the change in radial kurtosis was more pronounced in late-myelinating tracts ipsilateral to the side of seizure onset. Significance These results suggest a developmentally based preferential susceptibility of late-myelinating WM tracts to damage in MTLE. Brain injury in epilepsy may be due to the pathologic effects of seizures in combination with regional WM vulnerability.
Data Processing Workflow Automation in Grid Architecture

Because of the poor performance and the expensive license cost, traditional relational database management systems are no longer good choices for processing huge amount of data. Grid computing is replacing the place of RDBMS in data processing. Traditionally a workflow is generated by data experts, which is time consuming, labor intensive and error prone. More over, it becomes the bottleneck of the overall performance of data processing in the grid architecture. This paper proposes a multi-layer workflow automation strategy that can automatically generate a workflow from a business language. A prototype has been implemented and a simulation has been designed.
Receptor-mediated pinocytosis of mannose glycoconjugates by macrophages: Characterization and evidence for receptor recycling

125I-Mannose--BSA is taken up by alveolar macrophages by receptor-mediated endocytosis. Uptake is macrophage-specific and does not occur in polymorphonuclear leukocytes. Binding (4 degrees C) and uptake (37 degrees C) of 125I--Man--BSA are time- and ligand concentration-dependent [Kuptake = 40 nM; Kd (4 degrees C) = 10 nM]. When adjusted for ligand degradation, ligand uptake is linear with time. Binding saturates at 60 min and requires Ca++. Following binding, ligand remains on the cell surface where it can be released by EGTA and trypsin. Internalization of prebound ligand occurs very rapidly (t 1/2 less than 5 min) when cells are warmed to 37 degrees C. Following internalization of prebound ligand, binding activity is rapidly recovered (t 1/2 less than 5 min). Trypsin treatment (4 degrees C) substantially reduces binding activity (greater than 70% per 30 min). However, binding activity is rapidly recovered in cells treated with trypsin at 4 degrees C by warming to 37 degrees C in the absence of added ligand. Trypsin treatment at 37 degrees C rapidly destroys binding and uptake. On the contrary, 4 degrees C trypsin treatment produces only a modest reduction in subsequent ligand uptake. These results, taken together with the observation that cycloheximide has no effect on ligand uptake, suggest that receptors must be spared from degradation and that reutilization of receptors probably occurs.
Molecular cloning of the human ryudocan promoter.

Abstract The promoter region of human ryudocan was isolated from a human λ dash genomic library and cloned into pBluescript. The 5′ flanking region contained a classical TATA box and GC rich regions that are commonly found in constituitively expressed genes. Two fusion gene constructs, one of 898 bp and the other of 480 bp of the 5′ flanking DNA coupled to the luciferase gene,were transiently expressed in a mouse endothelioma cell line and in human umbilical endothelial cell cultures. Both constructs were capable of driving luciferase expression; the 898 bp construct produced greater levels of luciferase activity than the 480 bp construct in both cell types examined. Analysis of the sequence revealed the presence of several potential sites for nuclear transcription factor binding; the relevance of these sites is presently unknown.
The oxygen isotopic composition of olivine and pyroxene from CI chondrites

The CI chondrites are taken to represent average solar system material based on the similarity of their elemental compositions to that of the solar photosphere. However, their oxygen isotope geochemistry is dominated by secondary minerals that formed during aqueous alteration on the CI parent body. Precursors to this alteration, namely olivine and pyroxene, are extremely rare in CI chondrites, precluding previous measurements of their oxygen isotopic composition. We report ion microprobe analyses of oxygen isotopes in single olivine and pyroxene grains separated from CI chondrites Orgueil and Ivuna. The CI chondrite olivine and pyroxene grains most likely represent liberated chondrule phenocrysts, based on petrographic, chemical, and isotopic evidence consistent with crystallization from a melt. The oxygen isotope data form an array that falls nearly along the carbonaceous chondrite 16O mixing line with δ18O values ranging from −9.3%, to + 12.3%o and δ17O from −11.3%o to +7.8%o, consistent with nebular processes being the source of the oxygen isotopic compositions. The degree of 16O-enrichment in Orgueil olivines is negatively correlated with FeO content, but the exact nature and timing of the process that introduced this variation remains unknown. The pyroxene oxygen isotopic compositions are similar to those of olivines with >5 mol% fayalite. The oxygen isotopic analyses of the olivine and pyroxene in CI chondrites have been used to revise previous models for the isotopic evolution of CI materials. Our data require more complete gas-solid equilibration in the nebula and constrain the initial aqueous fluids on the CI parent body to have lower Δ17O values than previously postulated. The refined model indicates that the temperature of aqueous activity on the CI parent body was no higher than ∼50°C, and the fluid:rock ratio was significantly less than previously estimated. Even prior to alteration and formation of secondary minerals, the CI chondrites were the most 16O-depleted carbonaceous chondrites and thus the solids originally contained in the CI chondrites are the most equilibrated nebular materials represented in the carbonaceous chondrites. The data suggest the oxygen isotopic composition of average solar system to be approximately equivalent to average terrestrial oxygen as recorded in the compositions of terrestrial and lunar basalts.
Trends, challenges and opportunities for performance engineering with modern business software

The author looks at trends in software and systems, and the current and likely implications of these trends on the discipline of performance engineering. In particular, he examines software complexity growth and its consequences for performance engineering for enhanced understanding, more efficient analysis and effective performance improvement. The pressures for adaptive and autonomous systems introduce further opportunities for performance innovation. The promise of aspect oriented software development technologies for assisting with some of these challenges is introduced.
Novel relativistic effect important in accelerators.

It is shown that a bunch of charged particles following a curved path in a magnetic field is subject to a force due to its own electro-magnetic field. One aspect of this is a ''centrifugal'' force acting on individual particles in the bunch. A resonance mechanism, capable of disrupting the beam at modest currents, is given as an example of the importance of this force. The theory is tested with observations from the Cornell Electron Storage Ring. This force will cause important modifications to existing theories of accelerator stability.
An Inexpensive DME-Aided Dead Reckoning Navigator

ABSTRACT: This paper evaluates the design and performance of an aided dead reckoning navigator for general aviation applications. The system evaluated fuses the navigation information derived from an inexpensive dead reckoning system with infrequent range measurements from distance measuring equipment transponders. The dead reckoning system is mechanized using sensors that are becoming part of the standard avionics suite in newer general aviation aircraft. Simulation studies and flight test results are discussed. The results show that the system can achieve a navigation accuracy of 0.25 nmi.