cssi/SciSciGPT-SciSciNet huggingface dataset:
Microscopic derivation of zero-flux boundary condition in one-dimensional random walk in presence of a totally reflecting barrier

In this paper a rigorous probabilistic two-probability-parameter model of a diffusion barrier is investigated that describes comprehensively reflection, absorption, and segregation phenomena at a diffusion barrier. As a special case, a rigorous analysis of counting paths for 1D random walk in the presence of a reflecting barrier is presented. This paper defines and makes distinction between partially and totally reflecting barriers. So far, in the literature only a special case of partially reflecting barrier has been dealt with. A combinatorial formula is derived showing that in the presence of a totally reflecting barrier (at mb=0) the probability of a particle departing from position m=2j and arriving at position m=2k on the positive axis after N= 2M steps is given by W2j(2k,N) = [C(2M, M-j +k)-C(2M, M-j-k-l)]/[C(2M,M)+ 2 Σi=0j C(2M,M + i)], where C(n,m) denotes the binomial coefficient. This formula enables easy computation of any random walk redistribution of a diffusing species near or at the totally reflecting barrier. The analysis shows that for a particle starting its random walk at the barrier, the probability of finding it at the interface is diminishing with the number of diffusion steps N = 2M as 1/(M + 1) an_d that the peak of the probability distribution is moving away from the barrier with the increasing number of steps as √4M. Thus, the subsurface region is progressively depleted. The present analysis has bearing on the treatment of diffusion of impurities and point defects in thin films and in subsurface layers.
Praseodymium-cerium oxide as a surface-effect gas sensor

The gas sensing behavior of praseodymium doped cerium oxide (PrxCe1 − xO2 or PCO) has been examined for 0–1000 ppm CO or H2 in a 10% O2 atmosphere at temperatures ranging from 250–350_∘C. Total conductivity as a function of temperature suggests that oxygen diffusion kinetics are slow below approximately 350_∘C. Devices with x = 0.05 and 0.10 show stable, n-type gas sensing response, while those with x = 0.20 exhibit significant drift in sensor output, presumably due to bulk oxygen migration. The response to CO is significantly stronger than that to H2 at 300_∘C, and at 350_∘C the response to H2 is nearly zero, resulting in a CO-selective gas sensing element. Suggestions for the source of selectivity in PCO are presented.
Understanding the Home Language and Literacy Environments of Head Start Families: Testing the Family Literacy Survey and Interpreting Its Findings.

The current study investigated the nature of Head Start children's home literacy environments and the associations between these resources and children's early-language and literacy skills. At the beginning of the preschool year, families of 302 children completed the Family Literacy Survey. In general, Head Start families reported providing a variety of activities for young children; however, variability was observed across families on several aspects of the home literacy environment. Findings also revealed that the average family reported employing academically focused activities approximately once or twice per week, whereas play-related activities took place significantly more often, close to every day. Implications for measuring the home literacy environments of families in poverty and for helping educators to build upon and strengthen these home environments are discussed.
From gunstore to smoking gun: tracking guns that kill children in North Carolina

Abstract Purpose This study reviews the epidemiology of pediatric firearm deaths in North Carolina and estimates the time from the retail sale of guns to their involvement in pediatric firearm deaths. Methods The authors reviewed autopsy reports for all children 0 to 14 years of age that died of firearm-related injuries in North Carolina from January 1999 through December 2002. Data obtained included demographic information, firearm type, and manner of death. Data from the Bureau of Alcohol, Tobacco and Firearms, which traced guns involved in crimes and determined the time elapsed from purchase to their involvement in a crime (ie, time-to-crime were also reviewed). Results During the study period, 40 children died of firearm injuries. Mean age was 7.6 years. Handguns were responsible for the majority of deaths (59%) followed by shotguns (27%), rifles (10%), and undetermined cause (10%). Most deaths were homicides (67%) followed by unintentional death (18%), suicide (13%), and undetermined cause (2%). Most crime guns (76%) were purchased legally, and many (40%) had a time-to-crime of less than 3 years. Conclusions Legally purchased firearms pose a significant threat to children in North Carolina. A more restrictive approach to the sale of handguns is a logical approach to reducing pediatric firearm-related deaths in the United States.
The parkinsonian neurotoxin, MPP+ induces phosphorylated c-Jun in dopaminergric neurons of mesencephalic cultures.

Abstract The stress-activated protein kinase (SAPK) cascade serves a critical role in the apoptotic death of neuronal cells in response to a variety of cellular stresses. Recent in vitro and in vivo evidence has directly implicated this kinase in the death of dopaminergic nigral neurons in the MPTP model of Parkinson's disease (PD). To assess the involvement of c-Jun, a key transcription factor substrate of SAPK (also known as c-Jun N-terminal kinase, or JNK) in the MPTP-induced death of dopaminergic nigral neurons, we determined the ability of MPP+, the active toxin metabolite of MPTP, to induce the phosphorylated form of c-Jun in dopaminergic neurons in nigral (ventral mesencephalon) cultures. At a dose of MPP+ that specifically induces apoptotic changes in nuclear morphology in tyrosine hydroxylase-positive (dopaminergic) cells in these cultures, MPP+ induces nuclear phospho-c-Jun immunoreactivity (IR). The peak induction of phospho-c-Jun IR was observed 16 h after beginning MPP+ exposure, and preceded the maximal induction of apoptotic nuclear changes by approximately 8 h. These data support an important role for the SAPK/JNK pathway including its c-Jun transcriptional target in the apoptotic death of dopaminergic nigral neurons in the MPTP model of PD.
Cystic fibrosis transmembrane conductance regulator (CFTR) functionality is dependent on coatomer protein I (COPI)

Background information. Cystic fibrosis results from mutations in the ABC transporter CFTR (cystic fibrosis transmembrane conductance regulator), which functions as a cAMP-regulated anion channel. The most prevalent mutation in CFTR, the Phe508 deletion, results in the generation of a trafficking and functionally deficient channel. The cellular machineries involved in modulating CFTR trafficking and function have not been fully characterized. In the present study, we identified a role for the COPI (coatomer protein I) cellular trafficking machinery in the development of the CFTR polypeptide into a functional chloride channel. To examine the role of COPI in CFTR biosynthesis, we employed the cell line ldlF, which harbours a temperature-sensitive mutation in e-COP, a COPI subunit, to inhibit COPI function and then determined whether the CFTR polypeptide produced from the transfected gene developed into a cAMP-regulated chloride channel. Results. When COPI was inactivated in the ldlF cells by an elevated temperature pulse (39°C), the CFTR polypeptide was detected on the cell surface by immunofluorescence microscopy and cell-surface biotinylation. Therefore, CFTR proceeded upstream in the secretory pathway in the absence of COPI function, a result demonstrated previously by others. In contrast, electrophysiological measurements indicated an absence of cAMP-stimulated chloride efflux, suggesting that channel function was impaired. In comparison, expression of CFTR at the same elevated temperature (39°C) in an e-COP-rescued cell line [ldlF(ldlF)], which has an introduced wild-type e-COP gene in addition to the mutant e-COP gene, showed restoration of cAMP-stimulated channel activity, confirming the requirement of COPI for channel function. Conclusions. These results therefore suggest that generation of the folded-functional conformation of CFTR requires COPI.
A Review of Aerothermal Modeling for Mars Entry Missions

The current status of aerothermal analysis for Mars entry missions is reviewed. The aeroheating environment of all Mars missions to date has been dominated by convective heating. Two primary uncertainties in our ability to predict forebody convective heating are turbulence on a blunt lifting cone and surface catalysis in a predominantly CO2 environment. Future missions, particularly crewed vehicles, will encounter additional heating from shock-layer radiation due to a combination of larger size and faster entry velocity. Localized heating due to penetrations or other singularities on the aeroshell must also be taken into account. The physical models employed to predict these phenomena are reviewed, and key uncertainties or deficiencies inherent in these models are explored. Capabilities of existing ground test facilities to support aeroheating validation are also summarized. Engineering flight data from the Viking and Pathfinder missions, which may be useful for aerothermal model validation, are discussed, and an argument is presented for obtaining additional flight data. Examples are taken from past, present, and future Mars entry missions, including the twin Mars Exploration Rovers and the Mars Science Laboratory, scheduled for launch by NASA in 2011.
A fluorescence resonance energy transfer quantum dot explosive nanosensor

Quantum dots (QDs) are a versatile synthetic photoluminescent nanomaterial whose chemical and photo-physical properties suggest that they may be superior to conventional organic fluorophores for a variety of biosensing applications. We have previously investigated QD-fluorescence resonance energy transfer (FRET) interactions by using the E. coli bacterial periplasmic binding protein - maltose binding protein (MBP) which was site-specifically dye-labeled and self assembled onto the QD surface and allowed us to monitor FRET between the QD donor and the acceptor dye. FRET efficiency increased as a function of the number of dye-acceptor moieties arrayed around the QD donor. We used this system to further demonstrate a prototype FRET based biosensor that functioned in the chemical/nutrient sensing of maltose. There are a number of potential benefits to using this type of QD-FRET based biosensing strategy. The protein attached to the QDs surface functions as a biosensing and biorecognition element in this configuration while the QD acts as both nanoscaffold and FRET energy donor. In this report, we show that the sensor design can be extended to target a completely unrelated analyte, namely the explosive TNT. The sensor consists of anti-TNT antibody fragments self-assembled onto the QD surface with a dye-labeled analog of TNT (TNB coupled to AlexaFluor 555 dye) prebound in the fragment binding site. The close proximity of dye to QD establishes a baseline level of FRET and addition of TNT displaces the TNB-dye analog, recovering QD photoluminescence in a concentration dependent manner. Potential benefits of this QD sensing strategy are discussed.
Case II diffusion: effect of solvent molecule size

Abstract Rutherford back-scattering spectrometry has been used to examine the detailed composition vs. depth profile for polystyrene exposed at 25°C to the vapour (activity = 0.45) of a series of 1-iodo-n-alkanes ranging from iodopropane (n = 3) to iodooctane (n = 8), where n is the number of carbon atoms on the alkane chain. All the iodoalkanes tested exhibit case II diffusion. The velocity V of the case II front decreases exponentially with n. The diffusion coefficient D in the glass, which is determined from the concentration profile of the iodoalkanes ahead of the front using the measured value of V, decreases exponentially with increasing n; D decreases by approximately a factor of 4 for each carbon atom added to the alkane chain. These data are compared with previous studies, which show that D decreases exponentially with the molecular diameter d, calculated from the density of the pure liquid solvent: D = D0 e−δd, where δ is a constant for spherically symmetric solvent molecules. For the linear iodoalkanes D shows a similar exponential decrease but with a 20% lower value of δ, resulting in D for these non-spherical molecules being as much as three orders of magnitude larger than that for spherical molecules with an equivalent d. At the critical concentration ф c for case II diffusion to begin, the swelling rate d ф d t at the surface of the sample also decreases approximately exponentially with increasing n. The swelling rate decreases strongly with the osmotic pressure Pos, while Pos at ф c decreases with the molecular volume (and thus with n). The change in d ф d t with n, inferred from the corresponding change in Pos, can account for nearly all of the observed dependence of d ф d t on n. The Thomas and Windle model of case II diffusion leads to the following prediction for V: V = [( D ф c )( d ф d t )| ф c ] 1 2 . We find that the front velocities derived from this equation using the measured values of D and ( d ф d t )| ф c are in quantitative agreement with the experimental values of V for the entire series of iodoalkanes, a result that provides strong confirmation of the Thomas and Windle model.
Characterization of the nonvolatile compounds formed during the thermal oxidation of corn oil. II. Phthalate esters.

Twenty compounds with molecular weights ranging from 390 to 970 have been isolated from thermally oxidized corn oil with the aid of countercurrent distribution, column, and thin-layer chromatography. The structure of one compound was shown to be a phthalic acid esterified with an eight carbon normal and branched chain alcohol in both carboxyl groups. A similar compound was found in the products resulting from the oxidation of 2-oleyl-1,3-distearin and 1-palmityl-2,3 diolein as well as in a fat obtained from a local drive-in restaurant.
Microbial activity and bioturbation-induced oscillations in pore water chemistry of estuarine sediments in spring

Microbial activity and bioturbation-induced oscillations in pore water chemistry of estuarine sediments in spring
Alone Together: Multiplayer Online Ball Passing using Kinect - An Experimental Study

We present Alone Together, an interactive online ball playing environment augmented with three sets of Kinects. The play environment attempts to simplify the real world ball-passing exercise (or rehabilitation sessions) except that the players can be miles away from each other, and they interact without a physical ball. Kinects are used to map players' action into a virtual world including the passing of the virtual ball. A small-scale experiment shows inexperienced players' acceptance over such virtual setting compared to the physical ball-passing game within a short playing duration.
Hysteresis Effects for Sorption in Glassy Polymers

A theory based on taking into account structural rearrangements of the polymer matrix is used to analyze hysteresis effects that have been observed during a penetrant absorption−desorption cycle in...
All acyclic hydrocarbons: formula periodic table and property overlap plots via chemical combinatorics

It is sought to extend the characterization of isomer classes by using combinatoric techniques long used for isomer enumerations. To this end a general family of isomers (which is challenging to deal with even at the level of conventional enumeration) is considered, namely that of all acyclic hydrocarbons CnH2m with classical valence structures. This set of hydrocarbons is partitioned into structural-isomer classes, and these in turn are presented in the form of a ‘‘ formula periodic table’’ with n and m identifying rows and columns, respectively. Then various isomer-class-averaged characteristics (beyond isomer enumerations) are sought to be entered into the associated positions in this periodic table. Such characteristics include heat of formation, magnetic susceptibility and index of refraction, each of which may be estimated via substructural ‘‘cluster expansion’’. These cluster-expansion-estimated property averages as well as associated standard deviations are developed by way of a generating-function chemical combinatorics for isomers of up to n=25 carbons and 2m=52 hydrogens. These results then are incorporated in property ‘‘ overlap plots’’ to reveal overall isomer-class property trends in the periodic table for this set of ≈1013 structural isomers distributed over ≈360 isomer classes.
A Prospective Investigation of the Biopro® Hemi-Arthroplasty for the First Metatarsophalangeal Joint

First metatarsophalangeal joint hemi-implant arthroplasty is commonly used for 1-sided degenerative joint disease. This study examined outcomes in patients that underwent hemi-arthroplasty using the BioPro ® hemi-implant. Twenty-three of 30 patients completed the 12-month follow-up between October 2001 and June 2003. Repeated measures multivariate analysis of covariance was used to consider the influence of the implant on a number of dependent variables, while controlling for the amount of first metatarsal head cartilage degeneration. The average amount of first metatarsal head cartilage degeneration visualized intra-operatively was 71.8% ± 21.7%. From the preoperative to postoperative periods, the average hallux abductus angle went from 12.6° ± 6.5° to 10.2° ± 5.3° (P = 0.521), the average first intermetatarsal angle went from 11.0° ± 2.3° to 10.5° ± 2.0° (P = 0.434), the average first metatarsal declination angle went from 18.5° ± 4.1° to 18.3° ± 4.1° (P = 0.297), the average ACFAS score went from 41.2 ± 11.6 to 80.4 ± 8.8 (P = 0.003), average dorsiflexion went from 12.6 ± 12.4 to 50.0 ± 8.7 (P = 0.009), and average plantarflexion went from 8.0 ± 8.0 to 17.5 ± 6.7 (P
SYSTEMIC THERAPY FOR RENAL CELL CARCINOMA

Purpose: We review the status of systemic therapy for patients with advanced renal cell carcinoma.Materials and Methods: A literature search was performed on MEDLINE and CANCERLIT to identify results of systemic therapy for patients with renal cell carcinoma published from January 1990 through December 1998. Treatment results of chemotherapy agents, immunotherapy, combination programs and adjuvant therapy were reviewed.Results: No chemotherapy agent has produced response rates that justify its use as a single agent. Interferon-α and interleukin (IL)-2 demonstrated low response rates ranging from 10% to 20%. The results of 2 randomized trials suggest that treatment with interferon-α compared to vinblastine or medroxyprogesterone achieves a small improvement in survival. Response rates in patients treated with low dose IL-2 are similar to those achieved with a high dose bolus schedule but whether the responses are as durable is being addressed in an ongoing randomized trial. A randomized trial of interferon...
Chemical and petrographic correlations among carbonaceous chondrites

Detailed study of the petrographic and chemical properties of carbonaceous chondrites shows that the four distinct petrographic subtypes may be related to one of two distinct chemical subdivisions. These subdivisions are recognized primarily by the relative abundances of the nonvolatile elements Si, Ca, Al, Ti, Cu and Fe. C1, C2 and C3(O) chondrites form one subdivision. Vigarano subtype chondrites form the other subdivision and include chondrites previously referred to as C2, C3 and C4. Normalized to silicon, the abundances of Ca, Al and Ti are relatively enriched in Vigarano subtype chondrites, whereas Fe and Cu are relatively more abundant in C1, C2 and C3(O) chondrites. Volatile elements tend to correlate with petrographic subtypes rather than with chemical subdivisions.
Atomistic finite elements applicable to solid polymers

Abstract A three-dimensional atomistic finite element approach is presented. Two types of elements are established: chemical bond and van der Waals bond. The stiffness matrices of these elements are established based upon relations between bond deformations and restoration forces or moments. Once element stiffness matrices are established, a procedure, similar to conventional finite element analysis, can be employed to assemble a global stiffness matrix. Thus, one can derive relations between atomistic displacement and force. The new approach can be employed for both static and dynamic analysis. In order to demonstrate the approach, the deformation of an idealized polymer field is simulated: the stress–strain curve is derived and the progressive development of damage and failure is observed step by step.
Spatial orientation in the squirrel monkey : an experimental and theoretical investigation

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Aeronautics and Astronautics, 1990.
Tectonic Significance of Microstructures in Idaho-Wyoming Thrust Belt and Hinterland: ABSTRACT

Mechanics of foreland thrust belt development can be explained using paleostress orientations from dynamic analyses of microstructures in quartz, calcite, and dolomite. Deformation in the hinterland must also be considered since the two basic models--gravity spreading and lateral tectonic compression--predict substantially different stress fields in this region. Petrofabric studies in the Meade plate show that compression was dominantly layer-parallel, trending approximately east-west. On overturned fold limbs, compression at 50-80° to bedding suggests a locking angle which agrees well with existing theoretical and experimental analyses of kink-folding. Observed kink-fold geometries may be a necessary result of ramp configurations in the decollement thrust surface. These data are in accord with either of the two principal models. Dynamic analyses at scattered localities in the southern Idaho hinterland show primarily layer parallel or subparallel, east-west compression in all demonstrably allochthonous rocks at all structural levels. Fold vergence and local overturning indicate eastward translation along the undated, but probably Mesozoic, younger-over-older thrusts characteristic of this region. Near metamorphic core complexes, Tertiary thermal events may have affected preservation of older microstructures. Parautochthonous Precambrian metasediments between foreland and hinterland record compression at high angles to bedding. The age and origin of these microstructures are unknown at present. These studies indicate that maximum compression was nearly horizontal and oriented approximately east-west throughout southeastern Idaho during thrust belt activity. Therefore, the lateral tectonic compression model is favored. End_of_Article - Last_Page 669------------
Comment On: Omega-3 Free Fatty Acids for the Maintenance of Remission in Crohn Disease: The EPIC Randomized Controlled Trials:

Context: Maintenance therapy for Crohn disease features the use of immunosuppressive drugs, which are associated with an increased risk of infection. Identification of safe and effective maintenance strategies is a priority. Objective: To determine whether the oral administration of omega-3 free fatty acids is more effective than placebo for prevention of relapse of Crohn disease. Design, Setting, and Patients: Two randomized, double-blind, placebo-controlled studies (Epanova Program in Crohn's Study 1 [EPIC-1] and EPIC-2) conducted between January 2003 and February 2007 at 98 centers in Canada, Europe, Israel, and the United States. Data from 363 and 375 patients with quiescent Crohn disease were evaluated in EPIC-1 and EPIC-2, respectively. Interventions: Patients with a Crohn's Disease Activity Index (CDAI) score of less than 150 were randomly assigned to receive either 4 g/d of omega-3 free fatty acids or placebo for up to 58 weeks. No other treatments for Crohn disease were permitted. Main Outcome Measure: Clinical relapse, as defined by a CDAI score of 150 points or greater and an increase of more than 70 points from the baseline value, or initiation of treatment for active Crohn disease. Results: For EPIC-1, 188 patients were assigned to receive omega-3 free fatty acids and 186 patients to receive placebo. Corresponding numbers for EPIC-2 were 189 and 190 patients, respectively. The rate of relapse at 1 year in EPIC-1 was 31.6% in patients who received omega-3 free fatty acids and 35.7% in those who received placebo (hazard ratio, 0.82; 95% confidence interval, 0.51-1.19; P = .30). Corresponding values for EPIC-2 were 47.8% and 48.8% (hazard ratio, 0.90; 95% confidence interval, 0.67-1.21; P = .48). Serious adverse events were uncommon and mostly related to Crohn disease. Conclusion: In these trials, treatment with omega-3 free fatty acids was not effective for the prevention of relapse in Crohn disease. (JAMA. 2008;299:1690-1697.) Feagan BG, Sandborn WJ, Mittmann U, et al.
The Industrial Distribution of the Urban and Rural Workforces: Estimates for the United States, 1870–1910

The purpose of this article was to present the estimates of the urban and rural workforces derived from census data. These censusbased estimates present a fairly consistent pattern of change over time, and appear useful even in their present state. These estimates should be tested further against other time series so that we will eventually have a sound urban and rural workforce series with which to better analyze the process of structural change. The limited use to which these estimates were put in the present article yielded some interesting results, as well as some suggestions for further research. In terms of the United States workforce, changes in the industrial distribution reflect predominantly the relative shift in population from rural to urban areas, and little change in the workforce structure of either area. Indeed, at the sectoral level, there appears to have been more change occurring in rural than in urban areas. On the other hand, within the service sector there was more erratic change occurring in the rural areas than in the cities, but the differences may be easily reconciled. The urban sector experienced a more rapid increase and greater variability in the participation rate than did the rural sector. The pattern of variability was compared with the known evidence on unemployment, and variation in the former appears explicable in terms of variation in the latter.
Protection and jobs: explaining the structure of trade barriers across industries

Protection persists despite its weighty costs, and many studies have investigated its causes. Still unresolved is the question of why some industries receive significantly more protection than others. Shedding light on what explains the variation of trade barriers across industries may suggest more effective strategies for reducing protection (see [19]; and [30]). Also, incorporating the politics of trade is likely to improve trade theory (for example, see [8]).
Adverse selection, moral hazard, and wealth effects in the medigap insurance market

Using data from a longitudinal study of the recently retired we attempt to separate the moral hazard effect of Medicare supplementary (Medigap) insurance on health care expenditures from the adverse selection effect of poor health on Medigap coverage. We find evidence of adverse selection, but its magnitude is unlikely to create serious efficiency problems. Taking adverse selection into account reduces the estimate of the moral hazard effect. In addition, we find a strong positive wealth effect on the demand for supplementary insurance.
A fast nearest neighbor search algorithm by filtration

Abstract Classifying an unknown input is a fundamental problem in Pattern Recognition. One standard method is finding its nearest neighbors in a reference set. It would be very time consuming if computed feature by feature for all templates in the reference set; this naive method is O(nd) where n is the number of templates in the reference set and d is the number of features or dimension. For this reason, we present a technique for quickly eliminating most templates from consideration as possible neighbors. The remaining candidate templates are then evaluated feature by feature against the query vector. We utilize frequencies of features as a pre-processing to reduce query processing time burden. Our approach is simple to implement and achieves great speedup experimentally. The most notable advantage of the new method over other existing techniques occurs where the number of features is large and the type of each feature is binary although it works for other type features. We improved our OCR system at least twice (without a threshold) or faster (with higher threshold value) by using the new algorithm.
Cultured retinal glial cells are insensitive toplatelet-derived growth factor

Brain-derived astroglial cells respond to a mitogen from blood platelets, but glial cells from the retina have not been tested for mitogen sensitivity. For the studies reported here, monolayer cultures were established from explants of rabbit neural retina. The cultures consisted predominantly of Muller cells, the major retinal astroglia. DNA synthesis in the cultures, and in fibroblast cultures derived from rabbit skin, was assessed by radioautographic measurement of [ 3 H]thymidine labeling. Labeling was quantitated in cultures exposed to varying medium concentrations of heterologous (fetal bovine serum) and homologous (rabbit) sera in the range of 0.5% to 10% serum supplement. Labeling was also evaluated in cultures exposed to homologous, platelet-poor, plasma-derived serum (PDS), in the presence and absence of partially purified, human platelet-derived growth factor (PDGF). Unlike dermal fibroblasts, retinal astroglial cells did not exhibit increased DNA synthesis when exposed to increasing concentrations of either homologous or heterologous serum. In addition, glia did not display differential labeling in serum lacking (PDS) or containing (whole blood serum) platelet release materials. Further, addition of PDGF to glial cultures in PDS elicited no response under conditions in which dermal fibroblasts, a known PDGF target cell, showed a stimulation of DNA synthesis. Although brain-derived astroglial cells have been shown by others to respond to PDGF,retina-derived astroglia are apparently insensitive to this mitogen.
Structured Yet Functional An Alternative Conceptualization of Treatment for Communication Impairment in Autism

This article examines the structure-functionality relationship in traditional communication-based treatment approaches for children with autism. Contrary to popular opinion supporting either highly...
Walking Trails of the Giant Terrestrial Arthropod Arthropleura from the Upper Carboniferous of Kentucky

Arthropleurids were terrestrial, millipede-like arthropods. The genus Arthropleura Jordan from the Upper Carboniferous reached an enormous size of 2 m or more in length (Hahn et al., 1986). Occurrences are rare and the chronologic and paleogeographic distribution of Arthropleura coincides with the tropical Euramerican floral belt of the Carboniferous (Rolfe, 1969). The Carboniferous was a time of high atmospheric O2 levels (35%) compared to the current 21%, which may have favored the development of large terrestrial arthropods of this time (Dudley, 1998; Graham et al., 1997; Berner, 2001). Body fossils of Arthropleura range from the Visean to Early Permian (Rolfe, 1969; Schneider and Barthel, 1997), while trackways have been reported from the Visean (Pearson, 1992) to Stephanian (Langiaux and Sotty, 1977; Castro, 1997; Fig. 1). Arthropleura fragments have been described from Ohio, Pennsylvania, Illinois, and Nova Scotia. Only four Arthropleura trackway sites have been described from North America (New Mexico, Kansas, Nova Scotia, and New Brunswick ). Trackways provide information about size and locomotion that is not discernable from fragmentary body fossils. Figure 1 —Stratigraphic distribution and age for Arthropleura body and trace fossils. Numbered references in table: 1—Pearson (1992); 2—Briggs et al. (1979); 3—Ferguson (1966, 1975); 4—Briggs et al. (1984); 5—Briggs et al. (1984), Ryan (1986), McDonald and Gibling (2001); 6—Hunt et al. (2004); 7— Mangano et al. (2002) 8-Langiaux and Sotty (1977); 9—Castro (1997); 10—Rolfe and Ingham (1967); 11—Waterlot (1934, 1935), Guthoerl (1935, 1936); Rolfe (1969), Becker and Engel (1984); 12—Richardson (1959); 13—Hannibal (1997), Easterday (2001); 14—Proctor, 1998; 15—Schneider and Barthel (1997) The specimens of this study are well-preserved …
Water-soluble polymers: 59. Investigation of the effects of polymer microstructure on the associative behaviour of amphiphilic terpolymers of acrylamide, acrylic acid and N-[(4-decyl)phenyl]acrylamide

Abstract Water-soluble terpolymers of acrylamide, acrylic acid and N -[(4-decyl)phenyl]acrylamide have been synthesized by a micellar polymerization technique. Neutralization of the acid groups after polymerization yields hydrophobically modified polyelectrolytes. The ratio of the surfactant to the hydrophobic comonomer (SMR) was varied in successive polymerizations to yield a series of terpolymers with varied amphiphilic microstructures. Although each terpolymer in the series was identical in overall composition and molecular dimensions, profound differences in associative behaviour were observed. Terpolymers synthesized at low SMR exhibit large enhancements in viscosity owing to hydrophobic associations in 0.5 M NaCl. Those synthesized at high SMR behave in a similar fashion to a control acrylamide/acrylic acid copolymer. While viscometric studies indicate associative thickening behaviour, pyrene probe fluorescence studies fail to indicate the presence of well-organized hydrophobic microdomains.
Molecular Beam Studies of the "Super" Photoacid 5-Cyano-2-naphthol in Solvent Clusters

Clusters of the strong excited-state acid 5-cyano-2-naphthol with water, ammonia, methanol, and Me2SO were generated in a molecular beam and investigated by resonant two-photon ionization (R2PI) and fluorescence spectroscopies. In the free molecule and the smallest complexes these show that the S1 state is highly analogous to that of the parent 2-naphthol. Fluorescence attributable to excited-state proton transfer (ESPT) was observed for ammonia and water clusters, but not methanol or Me2SO. The ESPT size thresholds are, for ammonia 3 or 4; for water 8-10. The cluster ESPT characteristics of 5-cyano-2-naphthol show many similarities with those of the somewhat weaker excited-state acid 1-naphthol.
The organization and dynamics of corticostriatal pathways link the medial orbitofrontal cortex to future behavioral responses

Accurately making a decision in the face of incongruent options increases the efficiency of making similar congruency decisions in the future. Contextual factors like reward can modulate this adapt...
Tolerability of atomoxetine for treatment of pediatric attention-deficit/hyperactivity disorder in the context of epilepsy.

Abstract To examine atomoxetine's tolerability in patients with epilepsy, we reviewed medical records of all patients with epilepsy who were treated with atomoxetine in a tertiary care pediatric psychopharmacology practice. Twenty-seven patients (10.1 ± 4.2 years, 63% male) with an average seizure frequency at baseline of 7 ± 24 per month (median: 0, range: 0–90) were found. Symptoms of attention-deficit/hyperactivity disorder in twenty-five patients (92.5%) had previously not responded to stimulants. Atomoxetine, average dose 35.2 ± 24.4 mg, was given for a median of 26 weeks (range: 4–141). Seventeen patients (63%) discontinued atomoxetine due to: inadequate response ( n = 7, 26%), worsening behavior such as increased irritability/activation ( n = 7, 26%), nonadherence ( n = 1, 4%), emerging psychotic-like symptoms ( n = 1, 4%), and appetite decrease and tremor ( n = 1, 4%). There were no discontinuations because of seizure exacerbation. Atomoxetine dose, epilepsy etiology, seizure type, and comorbid psychiatric disorders did not predict discontinuation. No safety problems of sufficient magnitude to preclude prospective studies of atomoxetine in children with epilepsy were found.
SiC bipolar integrated circuits on semi-insulating substrates

Because of its wide bandgap, silicon carbide is attractive for applications in harsh environments, especially high temperature applications. The intrinsic carrier concentration in 4H-SiC is about 10−8 cm−3 at room temperature, and only 2×1011 cm−3 at 600 °C. Thermal generation currents are negligible in SiC, even at high temperatures, and the intrinsic temperature of SiC is above 900 °C. As a result, the upper temperature of SiC devices is limited by the stability of the associated metallurgy or dielectrics, rather than by the semiconductor. One of the most severe limitations is imposed by the SiO 2 gate insulator in MOS devices, which limits their maximum operating temperature to about 200 °C. For applications above 200 °C, bipolar devices are required. In this work we report the performance of second-generation bipolar integrated circuits in 4H-SiC. These circuits are suitable for small-scale integration applications in smart power, aerospace, automotive, and well logging applications.
Extraction Method for the Isolation of Terpenes from Plant Tissue and Subsequent Determination by Gas Chromatography

Abstract A method for the isolation and determination of terpenes from plant tissues is reported, involving extraction with methylene chloride for 24 h and quantitative analysis by gas chromatography. Relatively small masses of samples are required, the method is suitable for the analysis of large numbers of samples, and good precision (5–10%) was obtained. The utility of the method for a variety of plant materials was demonstrated by the analysis of Fraser fir ( Abies fraseri ) leaves and seeds, Balsam fir ( Abies balsamea ) leaves, red spruce ( Picea rubens ) leaves, and Queen Anne's lace ( Daucus carota ) seeds. The use of a composite method of sample preparation was investigated to improve the precision compared to the analysis of a class of individuals by averaging the analysis of individuals. Equal masses of 5–10 g of foliage from 10–20 individuals were mixed well to form the composite sample. The composite method had superior precision by an average factor of 7 over averaging the analysis of individuals.
High reversible hydrogen capacity of LiNH2/Li3N mixtures

Although Li 3 N can theoretically absorb as much as about 10 wt % hydrogen, its reversible hydrogen capacity is only about 5.5 wt % because only a fraction of the hydrogen absorbed can be desorbed at relatively low temperatures. In the present paper, it is shown that the addition of LiNH 2 to Li 3 N constitutes an effective method to increase the reversible hydrogen capacity. It was found that the reversible hydrogen capacity of the LiNH 2 /Li 3 N mixture depends on its composition. A maximum reversible hydrogen capacity of 6.8 wt % could be achieved when the pre-added LiNH 2 content in the LiNH 2 /Li 3 N mixture was between 28 and 50 mol %. Furthermore, the LiNH 2 /Li 3 N mixtures have fast hydrogenation kinetics and excellent cyclibility.
Clonal karyotypic abnormalities associated with reactive lymphoid hyperplasia

Cytogenetic abnormalities are important in the diagnosis and prognosis of hematolymphoid neoplasms. Although many recurrent karyotypic abnormalities are well-defined and known to underlie pathophysiologic processes contributing to malignancy, the significance of other cytogenetic changes is less clear. This uncertainty reflects an incomplete understanding of the frequency with which karyotypic abnormalities arise in benign processes. Numerous case reports and a small number of retrospective series have noted clonal cytogenetic changes in association with reactive-appearing lymph nodes. However, the incidence of such abnormalities has varied widely in published series. Here, we report the largest retrospective series of karyotypic abnormalities in association with reactive lymphoid hyperplasia published to date. Clonal karyotypic abnormalities were present in 6.3% of reactive lymph nodes with informative karyotypes and 5.1% of all reactive lymphoid tissues. These data suggest that karyotypic abnormalities are less frequently found in association with reactive lymphoid tissue than previously reported and provide a clearer picture of the baseline incidence of cytogenetic changes in benign lymphoid processes.
Localization and altered expression of AKR1C family members in human ovarian tissues.

Abstract Relative expression of AKR1C family members and 5αR1 were determined using gene specific quantitative real-time PCR method. Both ARK1C1 and AKR1C2 were found significantly reduced in ovarian tumor tissues compared to ovarian normal tissues. In contrast, AKR1C3 and 5αR1 were kept the same transcriptional levels between ovarian tumor tissues and ovarian normal tissues. Immunohistochemical staining indicates that AKR1C1 shares the same localization with AKR1C3. Loss of ARK1C1 and AKR1C2 in ovarian cancerous tissues may enhance progesterone signaling in ovary itself by decreasing the ability of progesterone metabolism.
Alpha-pattern coma: 24 cases with 9 survivors

Alpha-pattern coma denotes the association of a comatose state with an electroencephalogram consisting predominately of alpha-frequency activity. Over the past three years we have studied 24 such cases: 14 following cardiopulmonary arrest, 6 following respiratory arrest, and 3 following brainstem infarction. Of the 9 patients who survived, only 1 had a significant neurological deficit. It was found that: (1) alpha-pattern coma can result from a variety of neurological insults; (2) a significant proportion of patients survive, often with little or no deficit; (3) clinical evidence of intact brainstem function implies a favorable outcome; (4) the electroencephalogram was similar in survivors and nonsurvivors and did not differentiate diffuse cerebral dysfunction from focal brainstem disease; and (5) neuropathological studies demonstrated diffuse cortical as well as brainstem changes.
Observation of the effect of solute segregation on grain boundary structure

It is frequently observed that solute atoms segregate to grain boundaries in alloy systems where there is limited solubility in the solid solution. Auger spectroscopy has shown the presence of typically up to a monolayer of solute at internal interfaces in such systems. The practical consequence of such segregation is frequently the embrittlement of the grain boundary region, making it susceptible to fracture at relatively low stresses. It is of considerable interest to learn how the presence of the solute changes the mechanical properties of the boundary. Is the solute changing the chemical bonding across the interface as suggested by Messmer and Briant or is it changing the atomic structure, or perhaps both. In this paper an experiment is described which addresses the question of whether the presence of solute at the boundary influences the structure of the boundary. It is shown that in a small angle (001) twist boundary in the Fe-Au system, a small amount of Au causes a major change i the dislocation structure of the interface. These observations are evidence for the occurrence of a two dimensional phase transformation in the grain boundary.
Photography of shock waves in explosive crystals

Recent advances in high-speed microscopy allow successful streak photography of nonreactive shock waves passing through individual explosive crystals. Measurement of the shock velocity both in the crystal and in the water surrounding the crystal allows us to determine the shock pressures. These diagnostic tools have the required temporal and spatial resolutions to enable us to study the microscopic processes in nonreactive and possibly reactive shock environments.© (1992) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Isolation of proliferative epithelial cells from the rat cecum and proximal colon

Abstract A two-step technique, resulting in an enriched subpopulation of viable proliferative epithelial cells from the rat cecum and proximal colon is reported. Chelation of divalent cations combined with mild mechanical dissociation was initially used to obtain a single-cell suspension of heterogeneous cell types. Subsequent velocity sedimentation, using a linear isokinetic gradient, yielded a subpopulation of homogeneous viable epithelial cells with only a small number of goblet cells. These cells were mitotically active, as assessed by thymidine kinase and [ 3 H]thymidine incorporation, and appeared to originate from the proliferative region of rat colonic crypts.
Migraine Headache and the Patent Foramen Ovale

What are the indications for closure of a patent foramen ovale (PFO) in an adult? Very few questions in the field of cardiology are as controversial. Disagreement exists about definitive indications for PFO closure under various circumstances. Approximately 25% of all adults have patency of the foramen ovale. This translates to 60 million people in the United States who have this finding. It is estimated that there are 280 000 cryptogenic strokes per year.1,2 Patients with cryptogenic stroke have a higher prevalence of PFO than age- and sex-matched controls.3,4 Nevertheless, without pathological evidence, definitive proof of the linkage is hard to come by. Statistical associations can be suggestive or even rather convincing, but for the vast majority of patients, absolute evidence is lacking. Catheter interventions for such patients are usually performed at low risk, but are even small risks justified when cause and effect remains unproven? There is extensive literature that attempts to answer this question, but controversy remains. Article see p 1406 Patients who have had a cryptogenic stroke and a PFO are often treated with chronic anticoagulation therapy, and the risk of recurrent events appears to be reduced.5 Currently, the labeled indication for PFO device closure is recurrent stroke in patients who had an event despite treatment, or are not candidates for anticoagulation. Nevertheless, a considerable number of interventional and general cardiologists are convinced that device closure in the cardiac catheterization laboratory is …
Electrostatic DFT map for the complete vibrational amide band of NMA.

An anharmonic vibrational Hamiltonian for the amide I, II, III, and A modes of N-methyl acetamide (NMA), recast in terms of the 19 components of an external electric field and its first and second derivative tensors (electrostatic DFT map), is calculated at the DFT(BPW91/6-31G(d,p)) level. Strong correlations are found between NMA geometry and the amide frequency fluctuations calculated using this Hamiltonian together with the fluctuating solvent electric field obtained from the MD simulations in TIP3 water. The amide I and A frequencies are strongly positively correlated with the CO and N−H bond lengths. The CO and C−N amide bond lengths are negatively correlated, suggesting the solvent-induced fluctuations of the contribution of zwitterionic resonance form. Sampling the global electric field in the entire region of the transition charge densities (TCDs) is required for accurate infrared line shape simulations. Collective electrostatic solvent coordinates which represent the fluctuations of the 10 lowest...
Partial k-space reconstruction for magnetic resonance angiography by selective inversion recovery

The authors report their experience in selective-inversion-recovery vessel imaging with signals approaching a pure free-induction decay. Such acquisitions permit a shorter echo time and reduce the amount of flow-dependent phase shifts. The application of a partial k-space algorithm prevents distortion and spatial resolution loss that would arise with a conventional 2-D reconstruction. >