cssi/SciSciGPT-SciSciNet huggingface dataset:
The effect of cytosine methylation on the structure and geometry of the Holliday junction: the structure of d(CCGGTACm5CGG) at 1.5 A resolution.

Abstract The single crystal structure of the methylated sequence d(CCGGTACm5CGG) has been solved as an antiparallel stacked X Holliday junction to 1.5 A resolution. When compared with the parent nonmethylated d(CCGGTACCGG) structure, the duplexes are translated by 3.4 A along the helix axis and rotated by 10.8° relative to each other, rendering the major grooves more accessible overall. A Ca2+ complex is seen in the minor groove opposite the junction but is related to the B conformation of the stacked arms. At the junction itself, the hydrogen bond from the N4 nitrogen of cytosine C8 to the C7 phosphate at the crossover in the parent structure has been replaced by a water bridge. Thus, this direct interaction is not absolutely required to stabilize the junction at the previously defined ACC trinucleotide core. The more compact methylated junction forces the Na+ of the protected central cavity of the nonmethylated junction into a solvent cluster that spans the space between the junction crossover and the stacked arms. A series of void volumes within the methylated and the nonmethylated structures suggests that small monovalent cations can fill and vacate this central cavity without the need to unfold the four-stranded Holliday junction completely.
Cyclophilin A inhibition: targeting transition-state-bound enzyme conformations for structure-based drug design.

Human Cyclophilin A (CypA) catalyzes cis–trans isomerization of the prolyl peptide ω-bond in proteins and is involved in many subcellular processes. CypA has, therefore, been identified as a potential drug target in many diseases, and the development of potent inhibitors with high selectivity is a key objective. In computer-aided drug design, selectivity is improved by taking into account the inherent flexibility of the receptor. However, the relevant receptor conformations to focus on in order to develop highly selective inhibitors are not always obvious from available X-ray crystal structures or ensemble of conformations generated using molecular dynamics simulations. Here, we show that the conformation of the active site of CypA varies as the substrate configuration changes during catalytic turnover. We have analyzed the principal modes of the active site dynamics of CypA from molecular dynamics simulations to show that similar ensembles of enzyme conformations recognize diverse inhibitors and bind the...
Vibrational frequencies and structural determination of triethynylmethylgermane

Abstract The normal mode frequencies and corresponding vibrational assignments of triethynylmethylgermane are examined theoretically using the Gaussian98 set of quantum chemistry codes. Each of the vibrational modes was assigned to one of nine types of motion predicted by a group theoretical analysis (GeC stretch, CC stretch, CH stretch, CCH bend, GeCC bend, CGeC bend, HCH bend, CH 3 wag, and CH 3 twist) utilizing the C 3v symmetry of the molecule. Uniform scaling factors were derived for each type of motion. Predicted infrared and Raman intensities are reported.
Anisotropic structural, electronic, and optical properties of InGaAs grown by molecular beam epitaxy on misoriented substrates

We have investigated the structural, electronic, and optical properties of partially strain‐relaxed InxGa1−xAs layers, grown by molecular beam epitaxy on both misoriented and nominally flat (001) GaAs substrates. We find large anisotropies in bulk strain relaxation, interfacial misfit dislocation density, dark‐line defect density, and electron mobility, as well as a polarization anisotropy in cathodoluminescence for epilayers grown on misoriented substrates, in comparison with those grown on flat substrates.
Teaching the soundtrack

(1976). Teaching the soundtrack. Quarterly Review of Film Studies: Vol. 1, Film: Interdisciplinary Approaches to Theory and Teaching, Part Two, pp. 446-452.
Messenger RNA from Staphylococcus aureus that specifies macrolide-lincosamide-streptogramin resistance demonstration of its conformations and of the leader peptide it encodes

Abstract The + 1 site for transcription initiation of the inducible 23 S rRNA adenine methylase encoded by plasmid pE194 was determined experimentally by nuclease S1 mapping of mRNA synthesized in vivo, and by nuclease T1 mapping of (5′-γ-32P)-end-labeled transcripts synthesized in vitro. By partial digestion of the in vitro transcripts using S1 and cobra venom nuclease as probes of mRNA conformation, the analysis was extended to reveal single-stranded and double-stranded regions, respectively, which correspond to the critical stems and loops postulated for active and inactive conformations of the nascent mRNA. According to the model for induction, the transition from inactive to active conformation involves disruption of mRNA secondary structure which, in turn, is predicated on protracted occupancy by ribosomes complexed with erythromycin of one of the critical stem sequences. Ribosome occupancy of the critical stem sequence is due to the presence of an open reading frame that encodes part of a 19 amino acid residue “leader” peptide. The existence of this peptide, deduced from the nucleotide sequence of the control region upstream from the methylase structural gene, was demonstrated in vivo as part of a translational fusion with Escherichia coli β-galactosidase in which the first four amino acid residues of the N-terminal sequence of the fusion protein, analyzed directly by the microsequencing method, were found to comprise N-terminal amino acids 2 through 5, Gly-Ile-Phe-Ser, predicted for the leader peptide.
Effect of the uvs-2 allele of Neurospora crassa on the mutagenic potency of two N-hydroxylaminopurines and 2-aminopurine in the ad-3 forward-mutation test.

Abstract The mutagenic potencies of 3 purine analogs were determined in the ad-3 forward-mutation test in growing cultures of heterokaryon 59 (H-59), a nucleotide excision repair-deficient ( fuvs-2/uvs-2 ) 2-component heterokaryon of Neurospora crassa . Two N -hydroxylaminopurines, 2-amino-6- N -hydroxylaminopurine (AHA) and 6- N -hydroxylaminopurine (HAP), were potent and strong mutagens, respectively, whereas 2-aminopurine (AP) was a moderate mutagen. Dose-response curves showed that AHA and HAP were about equally mutagenic at low doses but that AHA was more mutagenic than HAP at high doses. Comparison of these results in H-59 with our earlier results in heterokaryon 12 (H-12) of N. crassa , which is identical to H-59 except for being DNA-repair-proficient ( uvs-2 + / uvs-2 + ), shows that the defect in nucleotide excision repair due to uvs-2 has little or no effect on the mutagenic potencies of these 3 purine analogs. Therefore, the nucleotide excision-repair pathway in N. crassa that is deficient in H-59 does not appear to have a major role in the repair of pre-mutational lesions induced by these 3 purine analogs. On the other hand, based on the controls of these experiments, the frequency of spontaneous ad -3 mutants was 4 greater in H-59 than in H-12. This result suggests that the nucleotide excision-repair pathway in N. crassa that is inactivated by the uvs-2 mutation has a major role in the repair of lesions that would lead to spontaneous mutation at the ad-3 + region if they were not repaired.
Social Networks and Job Search Outcomes among Male and Female Professional, Technical, and Managerial Workers

Abstract Scholars have debated whether informal or formal job search methods mediate gendered employment outcomes for women job-seekers relative to men. Existing research suggests that women are disadvantaged in terms of pay and opportunities when using personal contacts or other informal methods to secure job-related information. However, these studies have focused primarily on women in gender-typical occupations. This study contributes to the debate by asking whether women in gender-atypical occupations are also similarly disadvantaged when using contacts as a source of job information; and if so, in what ways do contacts matter? Based on a sample of male and female professional, technical, and managerial workers, we examine the role of personal networks in securing job-related information.
3362 Eus-guided fna in patients taking aspirin or nsaids.

Background: The use of EUS-guided FNA has increased significantly in the past few years. Based on previous studies, EUS-FNA may be complicated by bleeding, infection and pancreatitis. There is no data on the risk of bleeding after EUS-FNA in patients taking aspirin or NSAIDs. However, many centers recommend stopping these medications for at least 3-5 days before the procedure. Aim: The purpose of this retrospective study is to determine if EUS-FNA is associated with an increased risk of bleeding in patients who were taking aspirin or NSAIDs and did not stop them prior to the procedure. Methods: The endoscopy records of 260 patients who underwent EUS-guided FNA between 1/97 and 10/99 were reviewed for those patients who were taking aspirin or NSAIDs at the time of the EUSFNA. Patients identified made up study subset and there charts were reviewed for evidence of procedural complications including bleeding. Results: 20 patients (7.6%), 13 females and 7 males were identified. EUSguided FNA was performed on 21 sites (16 pancreatic, 6 mediastinal and 1 gastric). A total of 67 passes were made (average 3.1passes per site). For each patient, the site was routinely inspected after the last biopsy. For all 20 subjects, only minimal bleeding was noted similar to the bleeding seen after regular endoscopic forceps biopsy. There was no extensive or delayed bleeding reported. Conclusion: EUS-guided FNA appears to be safe in patients taking aspirin or NSAIDs in standard doses.
Investigation of breast cancer using two‐dimensional MRS

Proton (1H) MRS enables non-invasive biochemical assay with the potential to characterize malignant, benign and healthy breast tissues. In vitro studies using perchloric acid extracts and ex vivo magic angle spinning spectroscopy of intact biopsy tissues have been used to identify detectable metabolic alterations in breast cancer. The challenges of 1H MRS in vivo include low sensitivity and significant overlap of resonances due to limited chemical shift dispersion and significant inhomogeneous broadening at most clinical magnetic field strengths. Improvement in spectral resolution can be achieved in vivo and in vitro by recording the MR spectra spread over more than one dimension, thus facilitating unambiguous assignment of metabolite and lipid resonances in breast cancer. This article reviews the recent progress with two-dimensional MRS of breast cancer in vitro, ex vivo and in vivo. The discussion includes unambiguous detection of saturated and unsaturated fatty acids, as well as choline-containing groups such as free choline, phosphocholine, glycerophosphocholine and ethanolamines using two-dimensional MRS. In addition, characterization of invasive ductal carcinomas and healthy fatty/glandular breast tissues non-invasively using the classification and regression tree (CART) analysis of two-dimensional MRS data is reviewed. Copyright © 2008 John Wiley & Sons, Ltd.
Antibody reactive with Porphyromonas gingivalis serotypes K1-6 in adult and generalized early-onset periodontitis.

Background: Six serotypes of Porphyromonas gingivalis have recently been described. We sought to test the hypothesis that serotype specific carbohydrates from these strains are important antigens that elicit potent immune responses. Methods: Serum concentrations of IgG reactive with P. gingivalis serotypes K1-K6 were determined for 28 adult (AP) and 28 generalized early-onset (G-EOP) periodontitis patients previously determined to be seropositive for a broken cell preparation of P. gingivalis. To confirm relationships suggested for K1, K2, and K6 in the analysis of initial data, the study population was increased to 133. Results: Frequency of seropositivity for the 6 serotypes ranged from 26 to 54% of subjects. IgG concentrations ranged from 0 to 453 μg/ml with many subjects seropositive to more than one serotype. Concentrations for the subset of patients who was seropositive were high (mean responses ranged from 20 to 105 µg/ml for the 6 serotypes). Significant correlations between seropositivity to sero...
College dropouts: The developmental logic of psychosocial moratoria

Students who temporarily drop out of college frequently return with a better sense of direction. The reasons for this change are poorly understood. This paper describes several issues leave takers confront—including self-sustenance, autonomy, and escaping a fearful destiny—from a psychodynamic, social, and developmental perspective. The implications for psychosocial theories of adult development are also discussed.
Evaluating a servicescape: the effect of cognition and emotion

Abstract The debate among researchers regarding whether cognition precedes emotion or emotion precedes cognition in individuals’ evaluation process still remains unresolved and ambiguous. This paper attempts to review literature relating to the impact of the servicescape on customer behavior, with emphasis on the concept of Gestalt psychology. The Gestalt approach serves as a guide to understand and explain how an individual forms an impression or a perceptual image of a servicescape, how the image formation then leads to an emotional response, and finally, the actual appraisal or evaluation of a specific service environment.
Influence of magnesium, water, and sodium chloride on urolithiasis in veal calves.

Forty veal calves were fed milk replacers containing differing concentrations of Mg in a 16-w study. The concentrations were .1% (basal), .3%, .6% Mg, and .6% Mg plus 2% NaCl. The four groups were further subdivided into two groups fed reconstituted milk replacer at 14 or 17.9% DM. Weight gain was greater at the two lower concentrations of Mg. Calves fed .6% Mg or .6% Mg plus NaCl excreted significantly more Mg than calves fed .1 or .3% magnesium. The low water group (17.9% DM) excreted a more concentrated urine relative to Mg, Ca, and P than did the high water group (14% DM). No urethral obstructions were observed. Seventy percent of calves at .6% Mg and 30% of calves at .6% Mg plus NaCl had stones in their kidneys consisting primarily of calcium apatite and secondarily of struvite. Added NaCl reduced kidney and bladder calculi formation. When high amounts of water were fed, added NaCl prevented calculi formation completely. All calves fed the NRC level of .1% Mg performed normally.
The effects of operating conditions on semivolatile organic compounds emitted from light-duty, gasoline-powered motor vehicles

Abstract A thermal extraction-gas chromatography-mass spectrometry (TE-GC-MS) method was utilized to quantitatively examine semivolatile organic compounds (SVOCs) in fine particulate matter (PM 2.5 ) collected from light-duty, gasoline-powered vehicle (LDGV) exhaust. Emissions were analyzed from a subset of 18 vehicles tested in the Kansas City Light-Duty Vehicle Emissions Study (KCVES). The KCVES applied the LA92 Unified Driving Cycle (UDC), consisting of “cold start”, “hot stabilized running”, and “warm start” phases. The sensitivity of the TE-GC-MS analysis provided the opportunity to examine the emission rates and proportions of SVOCs (including polycyclic aromatic hydrocarbons (PAHs), hopanes, and steranes) in PM 2.5 on an individual vehicle basis for each UDC phase. Mean target SVOC emissions rates of 5.01 μg km −1 , 0.28 μg km −1 , and 0.63 μg km −1 were reported for the cold start, hot stabilized running, and warm start phases, respectively. Operating conditions as depicted by each UDC phase significantly affected SVOC emission rates and proportions in PM 2.5 . The cold start phase emission rates were significantly higher than the hot stabilized running and warm start phases for 89% of the target SVOCs. An increase in SVOC proportions in PM 2.5 was observed during the warm start phase compared with the cold start and hot stabilized running phase. This observation was significant for 31% of the target compounds, including chrysene, benzo[ a ]anthracene, and pyrene. Vehicles tested in both summer and winter provided emissions data describing ambient temperature effects. Emission rates were significantly higher in the winter for 92% of the target SVOCs. Until now, observations of specific SVOCs in motor vehicle emissions produced under changing operating conditions were scant. Such emissions data may be useful for emissions modeling, source apportionment studies, and human exposure assessments.
A Low-Cost Thermistor Device for Measurements of Metabolic Heat in Yeast Cells in Suspension.

Illustrated directions for the construction and use of a low-cost thermistor device are given. Attached to a servo-type millivolt chart recorder the device will record temperature changes as small as 0.001 °C and will simulate data obtained from an oxygen polarograph. Results of several experiments utilizing baker's yeast are included.
Development of Control Models and a Robust Multivariable Controller for Surface Shape Control

Surface shape control techniques are applied to many diverse disciplines, such as adaptive optics, noise control, aircraft flutter control and satellites, with an objective to achieve a desirable shape for an elastic body by the application of distributed control forces. Achieving the desirable shape is influenced by many factors, such as, actuator locations, sensor locations, surface precision and controller performance. Building prototypes to complete design optimizations or controller development can be costly or impractical. This shortfall, puts significant value in developing accurate modeling and control simulation approaches. This thesis focuses on the field of adaptive optics, although these developments have the potential for application in many other fields. A static finite element model is developed and validated using a large aperture interferometer system. This model is then integrated into a control model using a linear least squares algorithm and Shack-Hartmann sensor. The model is successfully exercised showing functionality for various wavefront aberrations. Utilizing a verified model shows significant value in simulating static surface shape control problems with quantifiable uncertainties. A new dynamic model for a seven actuator deformable mirror is presented and its accuracy is proven through experiment. Bond graph techniques are used to generate the state space model ofmore » the multi-actuator deformable mirror including piezo-electric actuator dynamics. Using this verified model, a robust multi-input multi-output (MIMO) H{sub {infinity}} controller is designed and implemented. This controller proved superior performance as compared to a standard proportional-integral controller (PI) design.« less
Clostridium botulinum Neurotoxins Act with a Wide Range of Potencies on SH-SY5Y Human Neuroblastoma Cells

We have described, in undifferentiated SH-SY5Y human neuroblastoma cells, the relative potency of Clostridium botulinum neurotoxin (BoNT) serotypes A-F Sensitivity of stimulated [3H]-noradrenaline ([3H]-NA) release to the toxins had a rank order of potency of: C > D > A > B > F after 3 days exposure. The difference between the most potent (BoNT/C: IC50 0.54 nM) and the least (BoNT/F: IC50 > 300 nM) was approximately 1,000-fold. Though fluid phase endocytosis may have been the mechanism of entry for low potency toxins the far higher potency of BoNT/C would suggest receptor-driven entry. Potency was not a reflection of the dependence of the release mechanism on a particular SNARE since the substrate specificities were mixed throughout the potency order. This indicated that the toxins differed in their efficiency of binding/endocytosis or enzymatic activity inside the cell. The serotypes that cleaved vesicle-associated membrane protein (VAMP) isoforms (BoNT/B, D and F) did not fully inhibit [3H]-NA release. Cleavage of the appropriate substrate proteins was observed for all serotypes. SNAP-25 cleavage by BoNT/A was shown to be a dose-dependent and correlated closely with reduction of release, supporting proteolysis as the mechanism by which toxin inhibited secretion. Comparison of the SH-SY5Y cell line sensitivity to BoNT/A with glycine releasing rat primary spinal cord neuron cultures, revealed a massive difference in potency; the primary cultures being approximately 200,000-fold more sensitive. The demonstration, using BoNTs, of the crucial role of SNAP-25, VAMP and syntaxin in SH-SY5Y cells suggests the use of this neuroblastoma as a model in the study of these proteins in neurotransmitter release.
Effects of Controversy on Learning in Cooperative Groups

Summary A study of the effects of controversy and concurrence-seeking in cooperative learning groups was conducted with 36 engineering students, in order to clarify the role of controversy by examining oral interaction among group members. Two controversial issues were studied and discussed for five days each: (a) hazardous waste (dispose vs eliminate) and (b) energy production (coal vs nuclear). At the end of each instructional period the students wrote a report, and completed an achievement test and an attitude survey. Trained observers recorded the oral interaction among the group members. Achievement and attitudes were similar for the two conditions, indicating that controversy did not have a negative effect. More of the oral interactions were elaborative in the controversy condition, whereas more were informative in the concurrence-seeking condition.
Contribution of both M1 and M4 receptors to muscarinic agonist-mediated attenuation of the cocaine discriminative stimulus in mice.

Rationale We previously showed that muscarinic agonists with M1 and/or M4 receptor affinities attenuated cocaine discrimination and self-administration in wild-type mice but not in M1/M4 double-knockout mice.
Antagonism by d-amphetamine of trimethyltin-induced hyperactivity: Evidence toward an animal model of hyperkinetic behavior

Abstract In male rats of the Long-Evans strain, either 7.0 mg/kg of trimethyltin (TMT) or 0.9% NaCl was administered by intragastric gavage. After a period of recovery from the typical signs of trimethyltin toxicity, each rat was tested at 72-hr intervals for its locomotor activity in an open field apparatus, the floor of which was divided into square grids. The baseline activity of each of the trimethyltin-treated rats was significantly greater than the saline-treated controls. (d-Amphetamine, injected intraperitoneally in a dose of 0.5 or 2.0 mg/kg, augmented the hyperactivity of the trimethyltin-treated animals. However, a 4.0 mg/kg dose of d-amphetamine markedly attenuated the hyperactivity of trimethyltin-treated rats while elevating that of the controls. Since trimethyltin produced an autism-like behavioral disorder involving hyperactivity, perseveration, aggressiveness and impairment in problem-solving and memory function, the placating effect of amphetamine supports the proposition that the pathology due to trimethyltin may represent an experimental analogue to the hyperkinetic syndrome in children.
Stretch mounting for osmotic membranes

Abstract A simple Lucite osmometer is described which combines membrane rigidity with accuracy to within 1%. The system potentially has wide applications, one being the measurement of blood colloid osmotic pressures within a few minutes.
Trends in the Diagnosis of Overweight and Obesity in Children and Adolescents: 1999–2007

OBJECTIVE. Pediatric overweight and obesity are increasingly prevalent problems and have received much attention in recent years, but it is unclear whether this publicity has affected diagnosis by clinicians. We undertook the current study to assess trends in diagnosis rates of overweight and obesity in children. PATIENTS AND METHODS. We analyzed electronic medical record data from 60711 patients aged 2 through 18 years with at least 1 well-child visit between June 1999 and October 2007 in a large academic medical system in northeast Ohio. Diagnosis of weight problems among children classified as overweight and obese was assessed by using International Classification of Diseases, Ninth Revision codes. Logistic regression was used to examine the impact of patient characteristics on diagnosis and to investigate trends over the study period. RESULTS. On retrospective review of BMI measurements recorded for patients during the study period, 19% of the children were overweight, 23% were obese, and 8% (33% of the obese patients) were severely obese; among these, 10% of overweight patients, 54% of obese patients, and 76% of severely obese patients had their conditions diagnosed. BMI, age, and number of overweight visits were positively associated with diagnosis. Female patients were more likely to have been diagnosed than male patients. Black and Hispanic patients were more likely to have been diagnosed than white patients. There was a statistically significant trend toward increasing diagnosis during the study period, although the percentage of patients diagnosed per year seemed to plateau or decrease after 2005. CONCLUSIONS. Although clear BMI definitions of pediatric weight problems exist, a large percentage of overweight and obese patients remain undiagnosed. Diagnosis increased during the study period but remained low among overweight children, for whom early intervention may be more effective. Identification of overweight and obese patients is the first step in addressing this growing epidemic.
Glycoconjugate synthesis during early pregnancy: Hyaluronate synthesis and function

The synthesis of various glycoconjugate classes by mouse uteri during the pre- and peri-implantation period has been examined using [3H]glucosamine as a metabolic precursor. A unique and dramatic (five- to sixfold) increase was observed in the synthesis of hyaluronate on the day upon which embryo implantation normally occurs. Mated, but nonpregnant mice did not display increased hyaluronate biosynthesis. In contrast to hyaluronate, the synthesis of most other types of glycoconjugates remained fairly constant during the first 5 days of pregnancy. Low (1500-5000)-molecular-weight N-linked oligosaccharides constituted the major class of oligosaccharides synthesized under all conditions. High (greater than 10,000)-molecular-weight glycoconjugates constituted the second most abundant class of glycoconjugates synthesized (20-30%). Most (85%) of the newly synthesized hyaluronate was associated with the nonepithelial cell types of the uterus. Experiments using ovariectomized mice receiving steroid hormones demonstrated that uterine hyaluronate synthesis was induced preferentially by an artificial decidual stimulus and implicated stromal cells as the site of hyaluronate synthesis. In addition, it was demonstrated that tissue culture plates coated with hyaluronate, but not other polysaccharides, support attachment and spreading of a large fraction (60 to 70%) of embryos cultured in serum-free medium. Collectively, these studies indicate that increased hyaluronate biosynthesis accompanies decidual responses in the endometrium and may promote embryo implantation following initial penetration of the uterine epithelium.
Link tracking: Quantifying network flows from qualitative node–link digraphs

ABSTRACT This paper gives a possible explanation for how changes in holistic network organization can come to be reflected in changes in mechanistic processes thought to be under local control by organisms and abiota. Most point-contact, or node(●)-link ( — , → ), networks in science are qualitative. Their complexity is great and quantification is difficult. Networks depict wholeness and are models for holism. Mathematically, they are graphs, unweighted when unquantified, and either undirected ( ●– ●; most social networks) or directed ( ●→ ●; most ecological food webs). Directed graphs are digraphs. The question of this paper is, can unweighted digraphs be used to quantify mass–energy link flows? A methodology, link tracking , is developed to achieve this. Simple paths (no repeated nodes) and cycles in the network are identified. Links for different node pairs are tallied along these pathways, and used to calculate transition probabilities. These are extended to all pathways (direct + indirect) by matrix inversion; the resultant coefficients are used in conjunction with boundary inputs to generate flows. Applied to an ecological stock-and-flow model, empirical measurements lay within ±2 times the corresponding link tracking values. This reinforces the intuition that digraph structure and flow function are intimately related, which is the principal general finding of the paper. However, only one “structure-based” parameterization is calculable per digraph by link tracking, whereas many “functional” empirical flows are possible. The meaning of the link tracking values is therefore to be resolved. In discussion, it is hypothesized that link tracking structural flows are basins of attraction – centrally tending mean flows around which realizable empirical flows are constrained by structure to be distributed. The methodology sheds light on previously unexplained results from an early radiotracer study of experimental ecological networks. Uses of link tracking to expand existing knowledge of food webs and other kinds of qualitative networks are considered.
Measurements of Ionization Constants and Partition Coefficients of Guanazole Prodrugs

A series of guanazole prodrugs, which are less water soluble than the parent compound and have relatively higher molecular weights, was recently synthesized, and their antineoplastic activities were measured in vitro. In the present work, the ionization constants and partition coefficients of these compounds were measured for the first time. In contrast to guanazole, which is a weak base, guanazole prodrugs have been shown to be weak to moderate acids due to the electronic effects of the acyl group and the heterocyclic ring. Possible tautomeric and resonance structures are presented to account for the pKa values observed. Both the inductive and resonance effects of the substituent are important in determining the values of the ionization constant. The preparation of the prodrugs not only altered the lipophilicity but also drastically changed the acid-base property of the parent compound. The observed true partition coefficient values in most guanazole prodrugs studied were higher than those calculated from the π-constants. Under highly ionized conditions, the small amount of water in the octanol layer has a significant effect in trapping a substantial amount of the ionized species in the octanol layer and gives rise to a higher log P value than expected. Under nonionized conditions, intramolecular hydrogen bonding plays an important factor in electron delocalization and reduction of hydrogen bonding with water molecules, causing the nonionized species of the guanazole prodrugs to be more lipophilic than expected.
Holography with low-energy electrons.

We have employed an ultrasharp tip, prepared by field-ion techniques, as a coherent point source of low-energy electrons. The source, which constitutes the origin of a spherical electron wave, is positioned close to small carbon fibers, at which some of the electrons are elastically scattered. At macroscopic distances a hologram is observed, which arises from the interference of the scattered electrons with the reference wave. The high magnification of the interference pattern is brought about purely by geometric projection. No electron lenses are emloyed and, thus, the high-resolution microscopic information gained by this novel technique is not affected by aberrations.
Occlusal caries experience in patients with asymptomatic third molars.

Abstract Purpose Our goals were to determine the prevalence of caries experience, carious lesions, or restorations on the occlusal surface, in asymptomatic third molars erupted to the occlusal plane, and to examine the association between caries experience in other molars and third molars within the same mouth and quadrant. Patients and methods Clinical data assessing oral health were collected from healthy patients (ASA I, II). The presence or absence of caries experience on the occlusal surface of third molars and on any surface of the first and second molars was recorded during clinical and radiographic examinations. The occurrence of caries experience for younger and older subjects was compared using the general association Cochran-Mantel-Haenszel statistic and the association of occurrence in the maxilla and mandible by the McNemar test. The association between caries experience in a third molar and caries experience in first and second molars also was assessed. Results Overall, 28% of the 303 patients with at least 1 third molar at the occlusal plane were affected by third molar caries. Patients 25 years or older had more caries experience in a third molar than those younger than 25 years, 39% versus 11% (P Conclusions The prevalence of caries in third molars erupted to the occlusal plane in these young patients was high, but not unique to third molars, particularly in those 25 years of age and older. Although these results provide a baseline description of the association between caries experience in first/second molars and associated third molars, data are needed from longitudinal studies to determine the value of first/second molar caries experience in predicting the risk of caries in third molars.
Grow Plants the Organic Way: Give Them the Soil Microbes They Crave

Review of : Teaming with Microbes: The Organic Gardener’s Guide to the Soil Food Web , revised ed.; Jeff Lowenfels and Wayne Lewis; (2010). Timber Press Inc., Portland, OR. 220 pages.
Generalized five-dimensional dynamic and spectral factor analysis.

We have generalized the spectral factor analysis and the factor analysis of dynamic sequences (FADS) in SPECT imaging to a five-dimensional general factor analysis model (5D-GFA), where the five dimensions are the three spatial dimensions, photon energy, and time. The generalized model yields a significant advantage in terms of the ratio of the number of equations to that of unknowns in the factor analysis problem in dynamic SPECT studies. We solved the 5D model using a least-squares approach. In addition to the traditional non-negativity constraints, we constrained the solution using a priori knowledge of both time and energy, assuming that primary factors (spectra) are Gaussian-shaped with full-width at half-maximum equal to gamma camera energy resolution. 5D-GFA was validated in a simultaneous pre-/post-synaptic dual isotope dynamic phantom study where {sup 99m}Tc and {sup 123}I activities were used to model early Parkinson disease studies. 5D-GFA was also applied to simultaneous perfusion/dopamine transporter (DAT) dynamic SPECT in rhesus monkeys. In the striatal phantom, 5D-GFA yielded significantly more accurate and precise estimates of both primary {sup 99m}Tc (bias=6.4%{+-}4.3%) and {sup 123}I (-1.7%{+-}6.9%) time activity curves (TAC) compared to conventional FADS (biases=15.5%{+-}10.6% in {sup 99m}Tc and 8.3%{+-}12.7% in {sup 123}I, p<0.05). Our technique was alsomore » validated in two primate dynamic dual isotope perfusion/DAT transporter studies. Biases of {sup 99m}Tc-HMPAO and {sup 123}I-DAT activity estimates with respect to estimates obtained in the presence of only one radionuclide (sequential imaging) were significantly lower with 5D-GFA (9.4%{+-}4.3% for {sup 99m}Tc-HMPAO and 8.7%{+-}4.1% for {sup 123}I-DAT) compared to biases greater than 15% for volumes of interest (VOI) over the reconstructed volumes (p<0.05). 5D-GFA is a novel and promising approach in dynamic SPECT imaging that can also be used in other modalities. It allows accurate and precise dynamic analysis while compensating for Compton scatter and cross-talk.« less
Effect of direct current countershock on atrial and ventricular electrophysiological properties and myocardial potassium efflux in the thoracotomised dog.

We reinvestigated the effect of direct current countershock (DCS) on atrial and ventricular electrophysiological properties and myocardial K+ release in the open-chested dog. This model allowed direct application of the electroshock paddles to the heart permitting reproducible energy input, simultaneous and comparative epicardial recordings for the measurement of conduction times (CT) and current threshold in different tissues, the determination of monophasic action potential duration (MAPD) with suction electrodes, and the measurement of coronary sinus K+ concentration [K+]cs. DCS produced changes in atrial and ventricular CT, in excitability, and in atrioventricular conduction (AVCT) even in the presence of cholinergic and (β-adrenergic receptor blockade. The type of electrophysiological response and its temporal relationship to [K+]cs after DCS suggest the DCS-induced release of myocardial K+ to play a role both in the antidysrhythmic effect of DCS and in the dysrhythmias following DCS. These effects were quite distinguishable both electrophysiologically and temporally from those of acetylcholine and catecholamines. More specifically, acetylcholine's effect on sinus rate, atrial APD, AVCT, and perhaps atrial excitability persisted for less than 10 s. The effect of catecholamines on automaticity and ectopic activity had a similar time course. The alterations in CT and excitability (often biphasic) attributable to the transient K+ elevation induced by DCS persisted for a half minute or longer. It seems DCS may have 2 antidysrhythmic phases: the first being immediate involving synchronisation of the non-refractory myocardium and the suppression of automaticity; the latter being delayed and dependent on transient local hyperkalemia.
Gas Turbine Control System Integration for Royal Caribbean Millennium Class Cruise Liner

Traditionally commercial marine propulsion needs have been met with direct drive reciprocating prime movers. In order to increase efficiency, simplify installation and maintenance accessibility, and increase cargo / passenger capacity; indirect electric drive gas and steam turbine combined cycle prime movers are being introduced to marine propulsion systems. One such application is the Royal Caribbean Cruise Line (RCCL) Millennium Class ship. This commercial vessel has two aero-derivative gas turbine generator sets with a single waste heat recovery steam turbine generator set. Each is controlled by independent microprocessor based digital control systems. This paper addresses only the gas turbine control system architecture and the unique safety and dynamic features that are integrated into the control system for this application.Copyright © 2000 by ASME
3D cloud detection and tracking for solar forecast using multiple sky imagers

Cloud detection and tracking (CDT) is the most challenging problem in integrating solar energy into the smart grid. In this paper, we present a novel 3D cloud detection and tracking using images from three TSI (Total Sky Imager), and propose to incorporate history into a multi-layer cloud detection pipeline. Our pilot study shows that the new CDT significantly improves the short-term solar irradiance forecasting and enable regional radiation prediction, which is impossible with a single TSI.
A developmental system for microcomputer based intelligent graphics terminals

A low cost intelligent graphics terminal for developmental work consisting of a Tektronix storage tube terminal and an ALTAIR 8800 microcomputer is described. The microcomputer system is used to develop and debug customized intelligent terminal configurations and features before a production model is finalized and fabricated. This allows flexibility in terminal design and allows changes to be tried easily before final versions are built. The customized terminal features that are described are the abilities to process a segmented display file, to provide refresh of up to 130 characters or vectors, to control accessory devices such as a flexible disk and a graphics tablet, to provide data compression of over 60% on large pictures, and to provide a local debugging utility.
Electron-Stream-Solid Interaction

High-current, relativistic, electron streams with low energy of transverse motion under-go very tight pinching in high-density matter. Power flux densities of ${10}^{16}$ W/${\mathrm{cm}}^{2}$ are realizable from modest electron streams, 50-100 kA at several MV, interacting with solids. Both cylindrical and spherical self-generated interaction geometries obtain from conditions realizable by use of dielectric-rod cathodes.
Closing and Opening Schools: The Association between Neighborhood Characteristics and the Location of New Educational Opportunities in a Large Urban District

ABSTRACT:New charter schools can potentially provide disenfranchised students with enhanced academic opportunities while simultaneously serving as neighborhood anchors that reinforce neighborhood s...
Co-Management of Natural Resources: A Comparison of Two Caribou Management Systems

The US Man and the Biosphere High Latitude Ecosystems Directorate compared two caribou management systems in Alaska and Canada. We examined the relationship between user involvement in management and management effectiveness. Measures of management effectiveness included: knowledge of the management system, agreement on acceptable harvest and herd monitoring practices, shared beliefs and perceptions on caribou population changes, perceptions of communications between management boards and caribou users, and expectations for cooperation of users with management actions. Our hypothesis was that the involvement of Canadian users in a joint management board would produce greater cooperation and agreement than the Alaskan hierarchical system. We conducted a census of government managers, and did surveys based on probability samples of approximately 200 traditional users in both countries. We found: (1) under a joint management board, government managers are more sensitive and responsive to user concerns; and c...
Bit decision table for hypercube decomposition

A new algorithm for subcube assignment and decomposition is introduced to solve the fragmentation problem in hyper-cube (n-cube) processor allocation. The sharing density vector introduced in the prime cube graph strategy [1] is used as a vehicle to develop the new algorithm. A bit decision table is devised to provide the key parameters for determining the decomposition. It is proven that the result of the algorithm is at least 22% better than the sharing density vector approach.
Bayesian generalized method of moments

We propose the Bayesian generalized method of moments (GMM), which is particularly useful when likelihood-based methods are difficult. By deriving the moments and concatenating them together, we build up a weighted quadratic objective function in the GMM framework. As in a normal density function, we take the negative GMM quadratic function divided by two and exponentiate it to substitute for the usual likelihood. After specifying the prior distributions, we apply the Markov chain Monte Carlo procedure to sample from the posterior distribution. We carry out simulation studies to examine the proposed Bayesian GMM procedure, and illustrate it with a real data example.
Stieltjes imaging of atomic and molecular photoabsorption profiles

Abstract The effective transition frequencies and oscillator strenghts obtained from principal representations of spectral moments, or from variational procedures using appropriate square-integrable basis functions, are employed in the Stieltjes imaging of atomic and molecular photoabsorption profiles.
Application of Time-Resolved Linear Dichroism Spectroscopy: Relaxation of Excited Hexamethylbenzene/1,2,4,5-Tetracyanobenzene Charge-Transfer Complexes

The charge-transfer complex formed between hexamethylbenzene and 1,2,4,5-tetracyanobenzene has been studied using time-resolved linear dichroism spectroscopy. These studies allowed the angle between the transition moment vectors for the absorptions of the ground-state charge-transfer complex and the product contact-radical ion pair to be measured. The results were compared with predictions based on the Mulliken two-state model and an assumed structure of the ground-state complex. The comparison between the observed and predicted angles supports the notion that relaxation of the excited charge-transfer complex leads to a change in the complex geometry. The time dependence of the dichroism allows the average rotational diffusion time constant to be determined. For this complex in 1,2-dichloroethane at room temperature, τOR = 75 ps. This value is comparable to what would be expected based on Debye−Stokes−Einstein diffusion theory at the stick boundary limit.
Practical Jet Noise Reduction for Tactical Aircraft

GE and NAVAIR are working together to find and develop practical techniques to reduce jet noise on legacy tactical aircraft such as the F/A-18. Noise is an important issue for the Navy that has grown dramatically over the last number of years. The two most important issues are the hearing loss induced during operations of these aircraft on aircraft carriers and the impact to communities around Naval Air Bases and training sites. A near term noise reduction goal of 3 dB has been established by NAVAIR as the first step in a much longer term plan to significantly reduce the noise felt in both of these situations. A near term solution for noise reduction implies that it can be implemented in the existing fleet with relatively little impact to the current air vehicle and the way it is operated, deployed, maintained, and funded. These constraints quickly limit the magnitude and types of changes that can be made to legacy engines or exhaust systems. In 2009, a static acoustic test on an F404 engine demonstrated that chevrons are equally effective at reducing noise all the way to full afterburner conditions. This test also measured thrust and the chevrons were demonstrated to result in very minimal performance impact at sea level static conditions. These two results are very important, as this was the first demonstration at full scale of practical noise reduction at afterburner conditions with minimal thrust impact. This paper will report on this latest test.Copyright © 2010 by ASME
The relationship of molecular weight, and sulfate content and distribution to anticoagulant activity of heparin preparations.

Abstract Fractions ranging in molecular weight from 4.8 to 12.5×10 3 daltons and showing wide variations in sulfate and d -xylose proportions were isolated from hog-mucosa and beef-lung heparin by-products. The anticoagulant activity of such fractions was found to be affected in concert by molecular weight, and by sulfate content and distribution. A heparin preparation having nearly half the 2-amino-2-deoxy- d -glucose residues substituted with N -acetyl groups retained appreciable biological activity, indicating that proportions of 2-sulfoamino-2-deoxy- d -glucose residues comparable to those present in heparan sulfate are consistent with maintenance of partial anticoagulant activity, provided that the ester sulfate content is similar to that found in native heparin. The presence of multiple repeating units containing 2-acetamido-2-deoxy- d -glucose residues in the interior of the molecule decreases biological activity.