cssi/SciSciGPT-SciSciNet huggingface dataset:
Energy coupling to ATP synthesis by the proton-translocating ATPase

This review summarizes recent work on energy coupling to ATP synthesis by the reversible, proton-translocating ATPase to mitochondria, chloroplasts, and bacteria. In the first sections, this enzyme is distinguished from other ATP-linked ion transport systems, and progress in the biochemical analysis is discussed. There is at present a reasonably consistent idea of the overall structure of the enzyme, and one can begin to assign specific functional roles to individual subunits of the complex. The latter half of the review deals with mechanisms of energy coupling, about which there is clear divergence of opinion. An "indirect coupling" model would allow for the possibility that H+ translocation transmits energy for ATP synthesis by driving the enzyme through a sequence of conformational states, so that H+ translocated need not take part in the chemistry of ATP synthesis. By contrast, a "direct coupling" mechanism would specify that H+ translocated must participate in the chemical reaction by combining with oxygen must participate in the chemical reaction by combining with oxygen from phosphate during the synthetic step. Such discussion is preceded by an outlined of the "proton well," since this idea forms the basis of one direct coupling model. In addition, it is suggested that the idea of a proton (ion) well may be of more general significance to the analysis of ion-coupled transport, because it includes the postulate that mechanistically significant ion binding can occur within the profile of the electric field. A proton (ion) well can be derived from both kinetic and equilibrium treatments, and from mechanistic considerations in fields as distinct as biochemistry and neurophysiology. As a result, it illustrates how further advances in formulating mechanisms of energy coupling might profit by a merger of technique and perspective from areas that have as a common goal an understanding of how large proteins catalyze movements of small molecules across a membrane.
Changes in the Adhesive Properties of Spider Aggregate Glue during the Evolution of Cobwebs

We compare the prey capture glues produced by orb-weaving spiders (viscid glue) and their evolutionary descendents, the cobweb-weaving spiders (gumfoot glue). These glues are produced in homologous glands but exhibit contrasting structure, properties and response to changing humidity. Individual glue droplet stretching measurements indicate that the gumfoot glue behaves like a viscoelastic liquid in contrast to the viscid glue, which behaves like a viscoelastic solid. Moreover, the gumfoot glue is largely humidity-resistant – elasticity and adhesion are constant across variation in humidity and there is weak volume-dependence. Viscid glue, however, is highly humidity-sensitive. The glue expands an order of magnitude and demonstrates a monotonous reduction in elasticity under increased humidity, while glue adhesion optimizes at intermediate levels of humidity. We suggest that observed differences are due to different ‘tackifiers’ used in these systems. These results shall inspire future efforts in fabricating stimuli-resistant and stimuli-sensitive materials.
Physical and Milling Characteristics of Wheat Kernels After Enzyme and Acid Treatments

ABSTRACT The current wheat milling process separates bran from endosperm by passing tempered wheat kernels through successive break rolls and sifters. Using hydrolytic enzymes during tempering degrades bran and aleurone layers and can improve milling efficiency and yield. This study was conducted to evaluate the effects of chemical and enzymatic treatments of wheat kernels before milling on physical and milling characteristics of the resulting wheat and flour quality. Hard wheat kernels were soaked in dilute acid or water and dried back to original moisture before being tempered with enzymes in water. Kernel physical and milling characteristics (600 g) were evaluated. Dilute acid soaking did not affect the 1,000-kernel weight and diameter but softened treated kernels. When treated kernels were pearled, bran removal was mostly from ends; and the reducing sugar content in enzyme-treated bran was significantly higher than the control. Compared with the control, acid-soaked enzyme-tempered kernels showed smal...
The Chemical Toxicology of 2-Deoxyribose Oxidation in DNA

Damage to DNA and RNA caused by oxidative mechanisms has been well-studied for its potential role in the development of human disease. Only recently, though, have we begun to appreciate that oxidation of the 2-deoxyribose moiety in DNA is also a determinant of the genetic toxicology of oxidative stress and inflammation, with involvement in more than just “strand breaks”, such as complex DNA lesions, protein–DNA cross-links, and protein and DNA adducts. As an update to a 1992 review of 2′-deoxyribose oxidation by bleomycin and the enediynes published in Chemical Research in Toxicology [Dedon, P. C., and Goldberg, I. H. (1992) Chem. Res. Toxicol. 5, 311–332], this review focuses on recent developments in the chemical biology, bioanalytical chemistry, and genetic toxicology of 2-deoxyribose oxidation products in DNA under biologically relevant conditions.
Structure and Dynamics of the Aβ21–30 Peptide from the Interplay of NMR Experiments and Molecular Simulations

We combine molecular dynamics simulations and new high-field NMR experiments to describe the solution structure of the Abeta(21-30) peptide fragment that may be relevant for understanding structural mechanisms related to Alzheimer's disease. By using two different empirical force-field combinations, we provide predictions of the three-bond scalar coupling constants ((3)J(H(N)H(alpha))), chemical-shift values, (13)C relaxation parameters, and rotating-frame nuclear Overhauser effect spectroscopy (ROESY) crosspeaks that can then be compared directly to the same observables measured in the corresponding NMR experiment of Abeta(21-30). We find robust prediction of the (13)C relaxation parameters and medium-range ROESY crosspeaks by using new generation TIP4P-Ew water and Amber ff99SB protein force fields, in which the NMR validates that the simulation yields both a structurally and dynamically correct ensemble over the entire Abeta(21-30) peptide. Analysis of the simulated ensemble shows that all medium-range ROE restraints are not satisfied simultaneously and demonstrates the structural diversity of the Abeta(21-30) conformations more completely than when determined from the experimental medium-range ROE restraints alone. We find that the structural ensemble of the Abeta(21-30) peptide involves a majority population (approximately 60%) of unstructured conformers, lacking any secondary structure or persistent hydrogen-bonding networks. However, the remaining minority population contains a substantial percentage of conformers with a beta-turn centered at Val24 and Gly25, as well as evidence of the Asp23 to Lys28 salt bridge important to the fibril structure. This study sets the stage for robust theoretical work on Abeta(1-40) and Abeta(1-42), for which collection of detailed NMR data on the monomer will be more challenging because of aggregation and fibril formation on experimental timescales at physiological conditions. In addition, we believe that the interplay of modern molecular simulation and high-quality NMR experiments has reached a fruitful stage for characterizing structural ensembles of disordered peptides and proteins in general.
Drop-the-losers design: Binomial case

Drop-the-losers designs were introduced for normal distributions as a method of combining phase II and III clinical trials together under a single protocol with the purpose of more rapidly evaluating drugs by eliminating as much as possible the delays that typically occur between the two phases of clinical development. In the design, the sponsor would administer k treatments along with a control in the first stage. During a brief interim period, efficacy data would be used to select the best treatment (with a rule to deal with ties) for further evaluation against the control in a second stage. At the end of the study, data from both stages would be used to draw inferences about the selected treatment relative to the control with adjustments made for selection in between the two stages. Because the inferences are model based, exact confidence intervals can be determined for the parameter of interest. In the present case, the parameter of concern is the probability of a beneficial response that is dichotomous in nature.
Mapping the conversion of atrial flutter to atrial fibrillation and atrial fibrillation to atrial flutter. Insights into mechanisms.

It is not generally believed that there is a relation between atrial flutter, thought to be due to a single reentrant circuit, and atrial fibrillation, thought to be due to simultaneously circulating multiple-reentrant wave fronts. However, there are many reasons to suggest that these rhythms are more closely related than previously thought. To test the hypothesis that the length of an area of functional block in the right atrial free wall is critical to the conversion of atrial flutter to atrial fibrillation and of atrial fibrillation to atrial flutter, we studied spontaneous and ATP-induced conversion of stable atrial flutter to sustained atrial fibrillation and spontaneous conversion of sustained atrial fibrillation to stable atrial flutter. We studied 13 episodes of the conversion of stable atrial flutter to sustained atrial fibrillation and sustained atrial fibrillation to stable atrial flutter in seven dogs with sterile pericarditis. Six episodes were spontaneous and seven were ATP related. All episodes were studied by using a multisite mapping system to record 190 unipolar electrograms (converted in the software to 95 bipolar electrograms) from the right atrial free wall along with ECG lead II. Atrial flutter induction was attempted by atrial stimulation (S1S2 or S1S2S3) or by rapid atrial pacing for > or = 20 beats from selected sites at selected rates. For both the spontaneous and the ATP-related episodes, stable atrial flutter was defined as any episode of > or = 5 minutes, and sustained atrial fibrillation was any episode of > or = 1 minute. During all the episodes of stable atrial flutter, a line of functional block with a mean length of 24 +/- 4 mm was localized on the right atrial free wall. When the previously stable line of functional block decreased to a mean of 16 +/- 3 mm (P or = prior length) to create a stable reentrant circuit, which then captured the right atrial free wall and subsequently both atria.(ABSTRACT TRUNCATED AT 400 WORDS)
Long-Term Effect of Instream Habitat-Improvement Structures on Channel Morphology Along the Blackledge and Salmon Rivers, Connecticut, USA

Habitat-improvement structures on the Blackledge and Salmon rivers date back to the 1930s and 1950s. Forty of these structures were investigated to determine their long-term impact on channel morphology. These structures include designs that continue to be used in modern restoration efforts. During the intervening period since these structures were introduced, several major floods have affected the two channels. The floods include three flows in excess of the 50-year event, including the flood of record, which has an estimated recurrence interval of almost 300 years. Despite the extreme flooding, many structures were discovered in varying conditions of operation. Grade-control structures and low-flow deflectors generally create some low-flow habitat (P = 0.815) but do not produce the depth of water predicted by design manuals (P < 0.0001). Unintended erosion has developed in response to many of the channel modifications especially along the outside of meanders. In addition, the mode of failure of grade-control structures has created localized channel widening with associated bank erosion. Meanwhile, cover structures have produced a 30% reduction in streamside vegetation with over 75% less overhead cover than unaltered reaches. Based on these results, it is important for prospective designers to carefully consider the long-term impacts of instream structures when developing future channel-restoration projects.
A Silicon Germanium, High Efficiency Power Amplifier Chipset for GSM/DCS-PCS/WCDMA Handset Applications

A power amplifier chipset for GSM and WCDMA mobile handset PAs has been designed and fabricated in the IBM Silicon Germanium BiCMOS 5AM process. This 3-chip set offers competitive performance and reliability for integrated GSM/DCS-PCS/WCDMA applications. The constant envelope (GSM and DCS-PCS) power amplifier designs are optimized for efficiency under pulsed GMSK conditions, achieving 55% and 45% PAE at 900 and 1880 MHz, respectively, at 3.4 V. The linear (WCDMA) amplifier performance has been optimized for continuous HPSK operation with - 36dBc ACPR maximum with up to 27 dBm output power. This family of PAs relies on two biasing architectures to address pulsed and linear operation by effectively utilizing the broad library of devices available in the BiCMOS process. Power device design and thermal conductivity of the silicon substrate are such that reliable operating temperatures during multi-slot GSM and WCDMA operation are assured. ICs are assembled in low-cost, 50-ohm matched modules or 4mm leadless (QFN) packages.
Nonperturbative solutions of the Lane-Emden equation

Abstract A new, iterative approach to solving the Lane-Emden equation leads to approximate solutions which display the coupling constant as a persistent interaction. The approach generalizes to nonlinear field equations.
Unintended Victims Of Organized Crime Witness Protection

This paper addresses unintended victimization which has resulted from the United States government's policy of protecting organized crime witnesses. Forms that unintended victimization take are des...
Assistive Technology Barriers and Facilitators during Secondary and Post-Secondary Transitions

This study identifies the technology barriers and facilitators as students with disabilities transition from secondary and post-secondary settings to adult life. Twenty-seven disability technology specialists from across the United States participated in a three round modified Delphi study. These specialists identified four top ten technology lists related to secondary and post-secondary transition issues including (a) facilitators when moving from secondary education to post-secondary settings, (b) barriers when moving from secondary education to post-secondary settings, (c) facilitators when moving from post-secondary settings to adult life, and (d) barriers when moving from post-secondary settings to adult life. Common themes include increasing professional knowledge, improving student self-determination, using best transition practices when using assistive technology, and establishing a technology infrastructure to support transition from school to post-secondary and adulthood settings.
Intranuclear localization of UV-induced DNA repair in human VA13 cells

We have investigated the intranuclear localization of DNA-repair synthesis in G1-phase VA13 human cells. Ultraviolet-irradiated cells were permitted to perform unscheduled DNA synthesis in 3H-thymidine (3H-TdR) and then extracted with nonionic detergent and 2 M NaCl to produce nucleoids in which residual nuclear matrix was surrounded by an extended halo of DNA loops. Autoradiographic analysis of these structures permitted discrimination of DNA repair between the matrix and halo regions. Repair label in nucleoids prepared from cells after exposure to fluences of 2.5–30 J/m2 exhibited a dose-dependent association with the nuclear matrix, which ranged from 80% after 2.5 J/m2 to 50% after 30 J/m2. These results support the view that DNA repair is a nuclear matrix-associated process. This conclusion is in agreement with our preliminary study (Harless et al., 1983) and the results of McCready and Cook (1984) but contrasts with that of Mullenders et al. (1983). Questions concerning the differing experimental desings and their potential effects on the localization of DNA repair are discussed. The implications of these results to previous attempts to isolate chromatin factors associated with DNA repair are also considered.
Respondent-driven sampling in participatory research contexts: participant-driven recruitment.

This article reports on the use of respondent-driven sampling (RDS) in participatory and community-based research. Participant-driven recruitment (PDR) retains all of the analytic capabilities of RDS while enhancing the role of respondents in framing research questions, instrument development, data interpretation, and other aspects of the research process. Merging the capabilities of RDS with participatory research methods, PDR creates new opportunities for engaging community members in research addressing social issues and in utilizing research findings within community contexts. This article outlines PDR’s synthesis of RDS and participatory research approaches, describes how PDR is implemented in community contexts, and provides two examples of the use of PDR, illustrating its process, potentials, and challenges.
Carbon fiber posts may have fewer failures than metal posts.

Article Title and Bibliographic Information Root canal posts for the restoration of root filled teeth. Bolla et al. Cochrane Database Syst Rev Jan 2007;24(1):CD004623. Reviewer Charles J. Goodacre, DDS, MSD Purpose/Question What is the failure rate of fiber posts compared to metal posts? Source of Funding Internal support from the Laboratoire Surface Interface en Odontologue (LASIO), France. There were no external sources of funding. Type of Study/Design Systematic review Level of Evidence Level 2: Limited-quality, patient-oriented evidence Strength of Recommendation Grade Grade B: Inconsistent or limited-quality patient-oriented evidence
Myosin light chain phosphorylation in frog heart

Abstract The P-light chain of frog heart myosin, isolated from 32 P-injected frogs, exists in three forms. Two forms are phosphorylated and the specific radioactivity of [ 32 P]phosphate is 2-times higher in one form than in the other. Both phosphorylated forms of the P-light chain could be converted into its unphosphorylated form.
Reversible Imine Shell Cross-Linked Micelles from Aqueous RAFT-Synthesized Thermoresponsive Triblock Copolymers as Potential Nanocarriers for ``pH-Triggered'' Drug Release

A temperature-responsive triblock copolymer, α-methoxypoly(ethylene oxide)-b-poly(N-(3-aminopropyl)methacrylamide)-b-poly(N-isopropylacrylamide) (mPEO−PAPMA−PNIPAM), was synthesized via aqueous RAFT (aRAFT) polymerization. At room temperature, the polymer is hydrophilic and exists as unimers in aqueous solution. Increasing the solution temperature above the lower critical solution temperature (LCST) of the PNIPAM block leads to self-assembly into micelles with PNIPAM cores, PAPMA shells, and mPEO coronas with hydrodynamic diameter (Dh) values of ca. 52 nm. The PAPMA shell was cross-linked with terephthaldicarboxaldehyde (TDA) at pH 9.0 to generate shell cross-linked (SCL) micelles with cleavable imine linkages. The reversible pH- and temperature-dependent formation and cleavage of the (SCL) micelles was followed by dynamic light scattering and NMR spectroscopy. As well, the release of the model hydrophobic drug prednisolone 21-acetate (PA) from loaded SCL micelles was studied at specific pH and temperatur...
Mössbauer quadrupole splittings and electronic structure in heme proteins and model systems: A density functional theory investigation

We report the results of a series of density functional theory (DFT) calculations aimed at predicting the 57Fe Mossbauer electric field gradient (EFG) tensors (quadrupole splittings and asymmetry parameters) and their orientations in S = 0, 1/2, 1, 3/2, 2, and 5/2 metalloproteins and/or model systems. Excellent results were found by using a Wachter's all electron basis set for iron, 6-311G* for other heavy atoms, and 6-31G* for hydrogen atoms, BPW91 and B3LYP exchange-correlation functionals, and spin-unrestricted methods for the paramagnetic systems. For the theory versus experiment correlation, we found R2 = 0.975, slope = 0.99, intercept = −0.08 mm sec-1, rmsd = 0.30 mm sec-1 (N = 23 points) covering a ΔEQ range of 5.63 mm s-1 when using the BPW91 functional and R2 = 0.978, slope = 1.12, intercept = −0.26 mm sec-1, rmsd = 0.31 mm sec-1 when using the B3LYP functional. ΔEQ values in the following systems were successfully predicted: (1) ferric low-spin (S = 1/2) systems, including one iron porphyrin wi...
Multigrid discretization method for PopZ polarization in Caulobacter cell cycle

Stochastic simulation of reaction-diffusion systems presents great challenges for spatiotemporal biological models. A straightforward extension of Gillespie's stochastic simulation algorithm (SSA) for spatially inhomogeneous systems leads to the Inhomogeneous Stochastic Simulation Algorithm (ISSA). However, the ISSA can be prohibitively expensive in computation, especially when the mesh size is too small. In this paper, a simple formula of the optimal mesh size is developed in the one dimensional case for reaction-diffusion systems. Based on our formula, we proposed a multigrid discretization method for stochastic simulation of multiscale reaction-diffusion systems. With the combination of proper discretization for species in different reaction and diffusion scales, we can greatly reduce the size of the system and achieve high efficiency. Numerical experiment with the stochastic simulation of PopZ polarization and polymerization in Caulobacter cell cycle is presented to demonstrate the accuracy and efficiency of the proposed discretization method.
Concurrent counting of two and three events in a serial anticipation paradigm

Rats were runway trained with four different series of reward events for the purpose of determining if two different number cues (two and three) could be adequately employed to correctly anticipate a terminal nonreward in the series. In two of the series, two rewarded runs always occurred prior to terminal nonreward; one of these series always began with a nonrewarded run, NRRN, and the other did not, RRN. For two other series, three rewarded runs predicted terminal nonreward, NRRRN and RRRN. Each rat experienced each of the four series once a day for 26 days. The interval between runs within a series was about 20 sec, the interval between series was about 15 min, and the order in which the series were presented was randomized daily. Distinctive floor cues (smooth/black or rough/white, balanced over animals) signaled two-count and three-count series. Our animals correctly anticipated (ran slowly to) the terminal nonreward of all four series. On Day 27, an initial nonrewarded run was added to the two series that had been initiated by nonreward (NNRRN and NNRRRN). This addition produced a disruption in terminal-event anticipation that lasted for only 1 training day. In all, the results imply that the animals were concurrently counting both two and three rewarded events, and it is further suggested that counting plays a prominent role in the rat’s serial learning.
Inhibition of N-linked glycosylation in Dictyostetium discoideum: Effects of aggregate formation

Abstract The aggregation program of Dictyostelium discoideum is extremely sensitive to the effects of tunicamycin when the drug is added to cells during the first few hours of starvation. Inhibition of development is observed with concentrations as low as 0.5γg/ml, which cause only a 25%-30% inhibition of general N-linked glycosylation. However, 0.5 γg/ml tunicamycin can result in the total inhibition of N-linked glycosylation of specific, developmentally regulated, proteins, as exemplified by the glycoprotein 117 antigen. If added after the first hours of starvation, tunicamycin cannot inhibit aggregation even when present at 10 γg/ml, which maximally inhibits N-linked glycosylation. cAMP pulses can override the inhibitory effects of tunicamycin on cell aggregation. The data support the hypothesis that there is an early developmental pathway that is dependent on the N-linked glycosylation of one, or a small set of developmentally regulated proteins and that this pathway may involve the biogenesis of the chemotactic signalling system. In addition, the data raise questions as to the role of N-linked oligosaccharides in cell cohesion.
A superfusion system designed to measure release of radiolabeled neurotransmitters on a subsecond time scale

A new method for subsecond measurement of release of neurotransmitters from nerve terminal preparations (e.g., synaptosomes) in vitro is described. Synaptosomes were prelabeled with [3H]GABA via a Na-dependent GABA uptake system. The prelabeled nerve terminals are retained on small glass fiber filters in a superfusion chamber accessed by three high speed, solenoid-driven valves. Microcomputer-programmed circuitry controls the timing of valve operation. Each valve controls the delivery of a separate solution to the chamber, permitting rapid and independent control of membrane potential, [Ca2+]e, and drug delivery. The minimal dead volume of the chamber and the relatively high solution flow rate afford time resolution for release of at least 60 ms. This time resolution was necessary to observe the most rapid of at least three components of GABA release.
Trials and Travels of a Nonconformist Layman: The Spiritual Odyssey of Stephen Offwood, 1564–ca. 1635

Few English Nonconformists of the late sixteenth and early seventeenth centuries have proven more elusive than Stephen Offwood.He was a Separatist who renounced Separatism and later joined the English Reformed Church of Amsterdam, whose pastor, John Paget, was a powerful enemy of separation. Offwood was also a prominent printer, publisher, and distributor of Puritan tracts. In 1632 he wrote a book of his own entitled An Advertisement to Jhon [sic] Delecluse, and Henry May the Elder.
Lift order problems for ordinary differential equations on manifolds

Fork≥0, let ττk:T k+1(M)=T(T k(M))→T k(M) denote the (k+1)th iterated tangent bundle in relation to a base manifoldT 0(M)=M. LetV represent a possibly nonstationary vector field overT k(M), and letQ be a subset/submanifold inT k(M). Sufficient conditions (and, whenV is completely integrable inQ, necessary and sufficient conditions) are established to ensure that all solutionsg toy′=V(t, y) lying entirely inQ have the formG=f [k], wheref [k] is thekth-order differential lift of a curvef lying inM. The relevance of the issue for higher order dynamical systems (especially in mechanics) is discussed. Higher order involutions and complete vector field lifts are examined from the viewpoint of the differential equations they present. Collateral results on the general solvability of initial value problems are obtained and numerous examples are discussed in detail.
Migrant Selectivity or Cultural Buffering? Investigating the Black Immigrant Health Advantage in Low Birth Weight.

Prior studies on population health have reported an “immigrant health advantage” in which immigrants tend to show better health outcomes compared to their native-born racial/ethnic counterparts. Migrant selectivity and cultural buffering have been proposed as explanations for this relative advantage, predominantly in studies that focus on Latino immigrants’ health in the US. This study adds to the relatively scant literature on black immigrant health advantage by comparing the two hypotheses (migrant selectivity and cultural buffering) as related to black immigrant health. The effect of nativity on infant low birth weight is tested using data from the US Fragile Families and Child Wellbeing Study. Results indicate that immigrant black mothers do have relatively better health outcomes that may result from cultural buffering, which reduces their risky health behaviors.
Synthesis, structure, and reactivity of some N-phosphorylphosphoranimines.

A large series of new N-phosphorylphosphoranimines that bear potentially reactive functional groups on both phosphorus centers were prepared by silicon-nitrogen bond cleavage reactions of N-silylphosphoranimines. Thus, treatment of the N-silylphosphoranimines, Me 3 SiN=P(Me)(R)X (R = Me, Ph; X = OCH 2 CF 3 and R = Me, X = OPh), with phosphoryl chlorides, RP(=O)Cl 2 (R' = Cl, Me, Ph), readily afforded the corresponding N-phosphoryl derivatives, R'P(=O)(Cl)-N=P(Me)(R)X, in high yields. Subsequent reaction with 1 or 2 equiv of the silylamine, Me 3 SiNMe 2 , resulted in ligand exchange at the phosphoryl (P=O) group to give the P-dimethylamino analogues, R'P(=O)(NMe 2 )N=P(Me)(R)X (R' = Cl, NMe 2 , Me, Ph; R = Me, Ph; X = OCH 2 CF 3 , OPh). These new N-phosphorylphosphoranimines (and one thiophosphoryl analogue) were obtained as thermally stable, distillable liquids and were characterized by NMR ( 1 H, 1 3 C, and 3 1 P) spectroscopy and elemental analysis. One member of the series, Cl 2 P(=O)N=P(Me)(Ph)OCH2CF3 (4), was also studied by single-crystal X-ray diffraction which revealed that the formal P(O)-N single bond [1.55(1) A] is shorter than the formal N=PR 2 X double bond [1.60(1) A]. Such structural features are compared to those of similar compounds and discussed in relationship to the unexpected thermolysis pathways observed for these N-phosphorylphosphoranimines, none of which produced poly-(phosphazenes).
Negative narratives in 1988 presidential campaign ads

Narrative polispots are mini‐stories that participate in two narrative structures simultaneously: the story being told in the ad (enonce,) and the story being told by the ad (enunciation). The relationships existing between those two structures can affect voters’ positive or negative feelings about a campaign. This essay illustrates these ideas from presidential campaign ads used in 1988; conclusions about Campaign ‘88, the rhetorical aspects of negative ads, and the sociocultural dimensions of presidential campaigning generally are drawn.
Respiratory Ecology of Aquatic Macroinvertebratestween dissolved oxygen and invertebrate1

Hypoxia (oxygen scarcity) is widespread in tropical freshwaters, particularly in dense swamps, and may be an important factor structuring benthic macroinvertebrate communities. Macroinvertebrates show a diversity of respiratory modes ranging from atmospheric breathing to tracheal gill breathing, and these adaptations affect their ability to use hypoxic water. The objectives of this study were to (a) describe the benthic macroinvertebrate community from ten swamp and river sires in Kibale National Park, Uganda, (b) determine the degree to which dissolved oxygen explains variation in abundance of respiratory groups (taxa with a similar respiratory mode) among sites, and (c) rest for significant seasonal variation in the abundance of the numerically dominant respiratory groups. Macroinvertebrates from monthly collections over a two-year period were identified to the lowest taxonomic level necessary to place them in functional respiratory groups. Across all sites, both the relative and absolute abundance of atmospheric breathers (e.5, pulmonate snails and nepids) and mantle/ctenidia breathers (primarily fingernail clams) were negatively correlated with dissolved oxygen, while the abundance of tracheal gill breathers (e.g. anisopterans and zygopterans) was positively correlated with dissolved oxygen. We did not detect significant seasonal trends in catch per unit effort of numerically dominant respiratory groups. Dissolved oxygen concentration was a good predictor of the abundance of some respiratory groups and may be a key factor in maintaining the structure and diversity of these assemblages.
Photoresistivity and Photo-Hall-Effect Topography on Semi-insulating GaAs Wafers

By placing a semi‐insulating GaAs wafer on a flat, rare‐earth magnet, and irradiating the surface with two perpendicular slits of light to form a Greek cross configuration, it is possible to perform photoresistivity and photo‐Hall‐effect topography on the wafer. The technique is nondestructive in that the contacts are tiny, removable In dots which are placed only on the periphery. By varying the wavelength of the light, selective centers, such as EL2, can be mapped. We compare a 1.1‐μm, photoexcited electron concentration map with a quantitative EL2 map on a 3‐in. undoped, liquid‐encapsulated Czochralski wafer.
Social support, organizational characteristics, psychological well-being, and group appraisal in three self-help group populations

This study examined the relationship of three social support and three organizational variables to two well-being and two group appraisal variables among 144 members of Compassionate Friends, Multiple Sclerosis, and Overeaters Anonymous self-help groups. An anonymous questionnaire was the major research instrument. Receiving social support was not significantly related to depression or anxiety but was positively related to perceived group benefits and group satisfaction. Providing social support and friendship were each positively related to one well-being and one group appraisal variable. Bidirectional supporters (i.e., individuals high on both receiving and providing support) reported more favorable well-being and group appraisal than Receivers, Providers, and Low Supporters. At the group level of analysis (n = 15 groups), groups with higher levels of role differentiation, greater order and organization, and in which leaders were perceived as more capable contained members who reported more positive well-being and group appraisal. The implications for future research and professional consultation to self-help groups are discussed.
A Developmental Functional MRI Study of Spatial Working Memory

Functional magnetic resonance imaging (fMRI) was used to examine patterns of cortical activity in children during performance of a spatial working memory task. Six children (8-10 years) and six adults (19-26 years) searched a linear array of four boxes for the appearance of a dot. In the visual blocks, participants made no response. In the motor blocks, participants were instructed to indicate the location of the dot on each trial using a button-press response. In the working memory blocks, participants were instructed to indicate at which location the dot had appeared 1 or 2 trials previously. Both children and adults showed activity in the left precentral and postcentral gyri, as well as the right cerebellum for the motor condition as compared to the visual condition. Comparison of the memory and motor conditions revealed reliable activity in the right superior frontal gyrus (BA 8), right dorsolateral prefrontal cortex (BA 10/46), right superior parietal cortex, and bilateral inferior parietal cortex for both adults and children. These results suggest that spatial working memory tasks activate very similar cortical regions for school-age children and adults. The findings differ from previous imaging studies of nonspatial working memory tasks in that the prefrontal activations observed in the current work tend to be more dorsal. Results are discussed in light of the significant behavioral performance differences observed between child and adult participants.
A FT-IR Reflection-Absorption Spectroscopic Study of an Epoxy Coating on Imidazole-Treated Copper

Abstract The effects of undecylimidazole complex on copper and untreated copper surfaces on polymerization of an epoxy resin were studied using FT-IR reflection-absorption spectroscopy. Catalytic effects have been observed on the polymerization of epoxy resin by the copper/imidazole complex and the copper surface. The epoxy resin showed an appreciable amount of polymerization on the imidazole complex at 100°C on copper. The thickness of the epoxy coating was increased while the imidazole complex dissolved into the bulk resin above this temperature. However, only a small amount of epoxy resin remained on the copper at elevated temperature. This phenomenon was observed only with the imidazole treated copper surface. The epoxy resin without any added catalysts polymerized above 150°C on untreated copper surface. The coating thickness increased rapidly and reached the asymptotic value (2.0 nm) at 150°C. A thicker and random layer was formed at elevated temperatures. The coating thickness was estimated from a ...
Geometric tomography: a limited-view approach for computed tomography

Computed tomography(CT), especially since the introduction of helical CT, provides excellent visualization of the internal organs of the body. As a result, CT is used routinely in the clinical arena to obtain threeand four-dimensional data. Data is obtained by exposing patients to a beam of x-rays from a number (about 1000) of different angles (projections). Then, standard CT makes use of the Radon transform to generate 3D data, denoted ~ f , directly from projections, denoted ~g. Thus, the projection relationship can be represented in matrix form by ~g = M ~ f where M represents the projection matrix. Note that techniques based on the Radon transform are in general limited by the Nyquist sampling criteria. The increasing use of CT has resulted in a substantial rise in population-radiation-dose [1], which may lead to an increased incidence of cancer in the population. In addition to increased use, the number of projections in the CT acquisitions is increasing to improve image quality which further increases patient radiation exposure as well as the reconstruction time. This latter issue can be improved by using new technology, e.g., graphical processing units (GPUs) [2], but the problem of radiation dose does remains. Reduction of the number of projections can result in artifacts and reduced image quality. Thus, new approaches are being pursued. This work was supported by The State University of New York at Buffalo Interdisciplinary Research Development Fund, NSF grant IIS-0713489, NSF CAREER Award CCF0546509, and the Toshiba Medical Systems Corporation. Copyright is held by the author/owner(s). SCG’09, June 8–10, 2009, Aarhus, Denmark. ACM 978-1-60558-501-7/09/06. Our novel algorithm is based on a key observation: Standard CT reconstruction techniques(such as filtered backprojection [3] or an algebraic reconstruction technique [4]) converges quickly when the intensity of all voxels are similar. This is because it “evenly” distributes the intensity of each pixel in a projection to all voxels along the corresponding projection ray. When all voxels have similar intensity, the value received by each voxel from one projection ray will be close to its actual intensity. As a results, a few projections will lead to a high quality reconstruction. Therefore, we have taken the approach to mathematically split up ~g = M ~ f into subproblems or Objects-of-Interest (OoI), effectively we are rewriting the general CT problem into: ~ gOoI1 = MOoI1 ~ fOoI1 ~ gOoI2 = MOoI2 ~ fOoI2 (1)
The Mobilization of Campaign Activists By the Party Canvass

This research examines the role of the personal contacting activities of the political parties as mobilizing forces in what Verba and Nie termed campaign activities. A reformulated rational choice model is discussed in which parties seek to reduce certain avoidable and unavoidable costs associated with political participation. Using data from the 1952 through 1994 American National Election Studies, it is shown that the party contact has been and continues to be a major factor in mobilizing campaign activists. Its influence is remarkably robust, maintaining statistical and substantive significance even after controlling for other important factors usually associated with political behavior.
Should Scientists Be Involved in Teaching Science Writing

(1979). Should Scientists Be Involved in Teaching Science Writing? The Journal of Environmental Education: Vol. 10, No. 3, pp. 21-24.
ENDOTHELIN-1 (ET-1) AND LYSOPHOSPHATIDIC ACID (LPA) MAY BE INVOLVED IN HEMATOMA-INDUCED MODIFICATION OF CEREBRAL MICROCIRCULATION. † 1509

ET-1 is increased by cerebral hematoma and inhibitors of ET-1 prevent hematoma-induced modification of cerebral arteriolar reactivity. However, the mechanism by which ET-1 contributes to hematoma-induced modifications of cerebral vascular reactivity is not known. We hypothesized that ET-1 injection intrathecally would 1) modify pial arteriolar reactivity to vasoactive agents similarly to hematoma and 2) increase CSF levels of LPA, a potential contributor to the altered cerebrovascular reactivity. Piglets received 3 ml injections containing either ET-1 (10-7 M) or aCSF over the left parietal cortex. Four days after injection, closed cranial windows were implanted over the injection area (α-chloralose anesthesia). Vascular reactivity to constrictor and dilator agents was examined. Constrictions to ET-1 (10-8 M), 5-HT (10-5 M), and NE (10-4 M) were potentiated; while dilations to PGE2 (10-5 M), iloprost(10-8 M), and histamine (10-5 M) were attenuated. The ET-1 induced modifications were very similar to those following hematoma. ET-1 and LPA levels were increased while basal and stimulated cAMP levels were decreased 4 days following ET-1 injection. These results indicate that intrathecal injection of ET-1 mimics hematoma-induced modification of cerebral vascular reactivity and of LPA production. The mechanism(s) of ET-1 and hematoma-induced modifications may involve LPA, which could contribute to the loss of dilator responses by inhibition of cAMP production.
Graded aspects of morphological processing: Task and processing time

Effects on targets of orthographically (O) and semantically (S) related primes were compared with morphologically related (M) primes in the lexical decision, naming, and go/no go naming tasks. The overall pattern typified the graded nature of morphological processing. Morphological relatedness produced facilitation whose magnitude varied across a range of stimulus onset asynchronies (SOAs of 66-300 ms) and tasks. The effect of semantic and orthographic similarity also depended on SOA and on task. Importantly, the effects of morphological relatedness and orthographic similarity diverged along a time course that reflected semantic processing but could only be approximated by the effect of semantic relatedness between prime and target.
Semi-Active Vibration Damping by Modulation of Joint Friction

The semi-active concept for vibration suppression in a clamped-free structural configuration is investigated. A fixed-free beam with the semi-active joint, designed to modulate friction, and hence the clamping load level, is considered. The vibration of the beam resulting from assumed initial conditions is examined in the time domain for a range of clamping load levels. The results obtained are studied and a control strategy is proposed to dissipate the energy efficiently and in a controlled way.Copyright © 2005 by ASME
Mössbauer studies of the speciation of tributyltin compounds in seawater and sediment samples

The antifoulant agents, bis-(tributyltin) oxide (TBTO), tributyltin acetate (TBTOAc) and tributyltin chloride (TBTCI) were mixed with various media. These media included distilled water, seawater, aerobic and anaerobic sediments. The Mossbauer spectra of the chloroform extracts of the distilled water and seawater mixed with these compounds were examined. The componds were mixed with aerobic and anaerobic sediments, and the Mossbauer spectra of the sediments were also examined. TBTO was converted to the hydroxide compound in all media except in anaerobic sediment where it was converted to an unidentified compound. TBTOAc and TBTCI were not changed by mixing with distilled water and aerobic sediment but were converted to the hydroxide compound in seawater and in anaerobic sediment.
Student well-being: Are they better off now?

Past and present well-being of university students from Canada and the United States are compared. Ratings for the domains of health, recreation, self-esteem, and education decreased significantly between the 1984 measures and the 1992 measures. Canadian students generally rated the domains lower than did students from the United States. Self-discrepancy measures tended to decrease and hope measures for the United States students indicated less hopefulness now than in 1984. In general, student perceptions of well-being seem poorer now than in the past.
Complement-mediated lesion of sympathetic ganglia in vitro with acetylcholinesterase antibodies

Abstract When administered to rats, antibodies against acetylcholinesterase (AChE) selectively destroy presynaptic inputs to sympathetic ganglia. To investigate the mechanism of this immunolesion, we created an in vitro system in which relevant components could be manipulated. Freshly dissected rat superior cervical ganglia (SCG) were incubated 15–20 h at 37°C in fresh human serum (a potent source of complement) with continuous oxygenation. More than 96% of neurons in six control ganglia retained synaptic inputs, as defined by action potentials or excitatory postsynaptic potentials (EPSP) upon stimulation of the preganglionic trunk. However, when anti-AChE antibodies were present (0.16 mg/ml), none of 61 neurons from six incubated ganglia showed synaptic responses although membrane potential and input resistance remained normal. Staining for AChE and synaptophysin (a synaptic vesicle marker) was also disrupted in ganglia exposed to AChE antibodies in complement-sufficient serum. When complement was eliminated by substituting serum that was heat-inactivated or deficient in C3, synaptic input was retained in 60–90% of neurons incubated with AChE antibodies. Choline acetyltransferase activity (ChAT), an enzymatic marker of cholinergic cytoplasm in sympathetic ganglia, was largely lost after incubation with AChE antibodies and serum. However, incubation with AChE antibodies in heat-inactivated serum, or serum that was deficient in C3 or C8, caused no measurable loss of ganglionic ChAT activity. These findings strongly implicate the complement cascade in the destruction of preganglionic sympathetic terminals that follows binding of AChE antibodies.
Tight Binding Inhibitors of N-Acyl Amino Sugar and N-Acyl Amino Acid Deacetylases

Very potent inhibitors were synthesized for the enzymatic deacetylation of N-acetyl-d-glucosamine-6-phosphate (NagA) and N-acetyl-d-glutamate (DGD). The methyl phosphonamidate derivative of d-glucosamine-6-phosphate bound to N-acetyl-d-glucosamine-6-phosphate deacetylase with an equilibrium dissociation constant of 34 +/- 5 nM at pH 7.5 and an association rate constant of 6.1 x 103 M-1 s-1. The inhibition constant is 4000-fold lower than the Michaelis constant for the substrate N-acetyl-d-glucosamine-6-phosphate. N-Acetyl-d-glutamate deacetylase was inhibited by the methyl phosphonamidate derivative of d-glutamate with an inhibition constant of 460 +/- 70 pM at pH 7.6. The inhibitor bound to the enzyme 500 000-fold tighter than the Michaelis constant for N-formyl-d-glutamate. These compounds mimic the putative tetrahedral intermediate formed upon nucleophilic attack of an activated water molecule on the amide bond of the target substrate. These inhibitors should prove useful in the elucidation of the enzyme-substrate interactions for enzymes within the amidohydrolase superfamily.
Evidence for an adrenergic mechanism in the control of body asymmetry.

Abstract The effect of phenylephrine, an α-1 adrenergic agonist, on development of body asymmetry was studied using a rat whole embryo culture system. Embryos were explanted at the presomite stage, cultured in 100% rat serum containing various concentrations of phenylephrine, and examined at the 20–25 somite stage for sidedness of asymmetric body structures, namely, bulboventricular loop, allantoic placenta, and tail. Phenylephrine treatment resulted in a dose-dependent increase of situs inversus with a maximum incidence of 52%. Coadministration of prazosin, an α-1 adrenergic antagonist, almost completely prevented this effect. Our results suggest that receptor-mediated stimulation of the α-1 adrenergic pathway is involved in the control of normal body asymmetry in developing rat embryos.