cssi/SciSciGPT-SciSciNet huggingface dataset:
Fatigue and Automation-Induced Impairments in Simulated Driving Performance

A driving simulator study investigated the effect of automation of the driving task on performance under fatiguing driving conditions. In the study, drivers performed both a manual drive, in which they had full control over the driving task, and an automated drive, in which the vehicle was controlled by an automated driving system. During both drives, three perturbing events occurred at early, intermediate, and late phases in the drives: in the automated drive, a failure in automation caused the vehicle to drift toward the edge of the road; in the manual drive, wind gusts resulted in the vehicle drifting in the same direction and magnitude as the "drifts" in the automated drive. Following automation failure, drivers were forced to control the vehicle manually until the system became operational again. Drivers' lateral control of the vehicle was assessed during three phases of manual control in both drives. The results indicate that performance recovery was better when drivers had full manual control of th...
Effect of prenylcysteine analogues on chemoattractant receptor-mediated G protein activation.

Abstract The hypothesis that carboxylmethylationn of γ suunits plays a role in G protein activation was tested by examining the ability of N- acetyl -S- farnesyl- l -cystein (AFC) and its methyl ester (AFC-ME) to inhibit G protein-mediated signalling in intact HL-60 granulocytes and isolated HL-60 plasma membranes. Incubation of HL-60 granulo vytes with AFC of AFC-ME inhibited superoxide release stimulated by fMet-Leu-Phe, but not opsonized bacteria. AFC-ME, but not AFC, inhibited NaF- and PMA-stimulated suproxide release. Addition of AFC to HL-60 membranes inhibited gMet-Leu-Phe-, leukotriene B4 (LTB4) and C5a-stimulated GTPγS binding and GTP hydrolysis more than it inhibited basal guanine nucleotide exchange. AFC-ME inhibited basal- and ligand-stimulated G protein activation with equal potency, but less potently than AFC. AFC also inhibited mastoparan-stimulated GTPγS binding. Binding of fMet-Leu-Phe and LTB4 to HL-60 membranes was completely inhibited by AFC, while AFC-ME inhibited ligand binding by less than 50%. Neither AFC nor AFC-ME inhibited pertussis toxin of cholera toxin-catalysed ADP-ribosylation pf αi. It was concluded that AFC interrupts propagation in G protein-dependent pathways by multiple mechanisms, including inhibition of ligand-receptor interactions, of receptor-G proteins coupling and of guanine nucleotide binding to G proteins. Carboxylmethylation alters the specificity of AFC interuption of signal propagation in intact cells and islated membranes.
Soot-free synthesis of C60

Abstract A new synthetic medium for the production of C60 has been found that does not produce soot. C60 was produced in the liquid phase of an aerosol of precursor soot at 700 °C. The precursor soot aerosol, a high temperature stable form of hydrocarbon, was produced by pyrolysis of acetylene at atmospheric pressure in a flow tube reactor. At 700 °C, the effluent particles were found to contain PAHs, small hydrocarbons and fullerenes but no observable black material. However, when the reactor temperature was changed to 800 °C, soot was also produced in the effluent particles along with PAHs and other small hydrocarbons, and the fullerene product disappeared. These results show a clear competition between the production of fullerenes and other forms of carbon. The filter-collected effluent was shown to be completely soluble in conventional solvents suggesting the possibility of an efficient cyclic synthetic process. Fullerenes were only found in the particle phase implying the first observed liquid phase synthesis of C60.
Plasmonic device using backscattering of light for enhanced gas and vapour sensing

Based on recent experimental and theoretical results obtained with gold-glass nanocomposite films, we propose a plasmonic device which uses the backscattering of light in order to make a highly sensitive gas/vapour sensor. The backscattered reflectance is used as the sensing signal since it has been shown, under certain conditions, that this component of the diffracted light is much more sensitive to a change of refractive index in the surrounding medium than the specular component. In addition, the backscattering presents an azimuthal angular dependency which is viewed as an advantage for practical implementation. The device consists of three planar layers. First, a glass substrate acting as incidence medium. Then a dielectric layer with a reduced refractive index with respect to the substrate is added which acts as a leaky-waveguide in order to maximize light coupling into the third sensing layer. The third layer is composed of gold nanopillars embedded in a dielectric matrix. Through numerical simulations, 2D periodic square and hexagonal arrays of gold nanopillars are compared in order to point out the influence of the nanocomposite arrangement in the photonic response. Moreover, disorder is introduced into these arrays in order to highlight the robustness of the sensing principle with respect to defects in the particle arrangement and size. For the purpose of gas/vapour sensing, we study the backscattered reflectance as it changes according to modifications in the dielectric environment at the external surface due to adsorption from gas or vapour. We determine the optimized device parameters and incidence angles.
Droplet Dynamics in a Non-uniform Flow Field

Abstract The present paper describes research to determine the lift and drag forces on a single heptane droplet in a non-uniform flow field over a range of Reynolds numbers of 1-30. Experiments are described for droplels (90-320μm) entering a jet of air (≈ 1 m/s) and fallowing unsteady curvilinear trajectories (for which few experimental studies and no theory exist). The lift and drag forces acting on the droplet are compared to those predicted by the most closely related theory and engineering formulae. The results support standard correlations and suggest that additional effects such as Basset forces reach not more than ten percent in these experiments.
Contaminant plumes and pseudoplumes in karst aquifers

Contaminant plumes in the strictest sense only occur in granular media. Defined as contaminated groundwater masses spreading by diffusion and hydrodynamic dispersion, plumes take the shape of a feather, from which the name derives. While plume-like masses may appear in a uniformly and densely fractured medium, they rarely develop in karst aquifers—though they are frequently alleged to exist. Unfortunately, a karst pseudoplume is often incorrectly interpreted to mean that monitoring wells are functioning appropriately; this misinterpretation can divert attention from gross contaminant movement to more distant locations. The highly heterogeneous and anisotropic character of karst aquifers, and the convergent nature of the conduit flow systems within them severely limit plume formation. What is often mistaken for a plume in these rocks may derive from three processes which will be discussed in this paper. First, the contaminant may move as a true plume in a granular overburden and find entry into the solution modified fractures of the bedrock at numerous points. There may be groundwater flow connections between these modified fractures, but such flow is most likely to be convergent rather than divergent. Second, when volatile contaminant vapors spread in an unsaturated epikarst, they may dissolve in percolating vadose groundwater and contaminate phreatic groundwater below. Third, solution conduits in karst are subject to regular and sometimes extreme increases in hydraulic head caused by concentrated quick-flow from precipitation events. Contaminated water in a conduit may be forced by these increases into the surrounding permeability structure, similar to temporary bank storage adjacent to a stream. When the head in the conduit declines, water returns to the conduit, leaving a fraction of the dissolved contaminants behind. With each successive rain event, the contaminant may be driven further into the surrounding rock.
Efficient Transmission Of Most Important Successive Image Approximations

Swift recognition of grey scale images transmitted through low bandwidth channels has been demonstrated by various progressive techniques in which a series of gradually refined image approximations are received and displayed. A previous technique demonstrated non-homogeneous progressive transmission in which image content controls transmission priorities, resulting in a decrease of the time required to receive a usable image. The non-homogeneous technique utilized two simultaneous decompositions, a quad-tree based spatial and a subimage information measure. The concept of simultaneous decomposition is extended to include a third component: grey level approximation. Just as an undecomposed quad-subtree provides a spatial approximation, values of pixels used as quad-subtree representatives are initially approximated and later refined. The three simultaneous decompositions are integrated so as to achieve, for a given transmission time, a higher degree of received image usefulness. The receiver does not have a priori knowledge about which image areas are to receive preferential treatment, and the level of preference is the pixel. The total transmission time for the series of approximations concluding in lossless reception, including preferential decomposition overhead, is comparable to the time required by non-progressive lossless methods. The technique is computationally simple and intended for general purpose processor architectures.
Adolescent nicotine-induced dendrite remodeling in the nucleus accumbens is rapid, persistent, and D1-dopamine receptor dependent

Chronic nicotine exposure during adolescence induces dendritic remodeling of medium spiny neurons (MSNs) in the nucleus accumbens (NAcc) shell. While nicotine-induced dendritic remodeling has frequently been described as persistent, the trajectory of dendrite remodeling is unknown. Specifically, no study to date has characterized the structural plasticity of dendrites in the NAcc immediately following chronic nicotine, leaving open the possibility that dendrite remodeling emerges gradually over time. Further, the neuropharmacological mechanisms through which nicotine induces dendrite remodeling are not well understood. To address these questions, rats were co-administered chronic nicotine (0.5 mg/kg) and the D1-dopamine receptor (D1DR) antagonist SCH-23390 (0.05 mg/kg) subcutaneously every other day during adolescence. Brains were then processed for Golgi–Cox staining either 1 day or 21 days following drug exposure and dendrites from MSNs in the NAcc shell digitally reconstructed in 3D. Spine density was also measured at both time points. Our morphometric results show (1) the formation of new dendritic branches and spines 1 day following nicotine exposure, (2) new dendritic branches, but not spine density, remains relatively stable for at least 21 days, (3) the co-administration of SCH-23390 completely blocked nicotine-induced dendritic remodeling of MSNs at both early and late time points, suggesting the formation of new dendritic branches in response to nicotine is D1DR-dependent, and (4) SCH-23390 failed to block nicotine-induced increases in spine density. Overall this study provides new insight into how nicotine influences the normal trajectory of adolescent brain development and demonstrates a persistent form of nicotine-induced neuroplasticity in the NAcc shell that develops rapidly and is D1DR dependent.
Emotional intelligence and smoking risk factors in adolescents: interactions on smoking intentions

Abstract Purpose To examine interactions between emotional intelligence (EI) and smoking risk factors on smoking intentions in adolescents. Methods EI is defined as the ability to: accurately perceive, appraise, and express emotion; access and/or generate feelings in facilitating thought; understand emotion and emotional knowledge; and regulate emotions. EI of 416 6th graders (53% girls) from middle schools in the Los Angeles area (mean age=11.3 years; 32% Latino, 29% Asian/Pacific Islander, 13% white, 19% Multiethnic, 6% Other) was assessed with an abbreviated version of the Multifactor Emotional Intelligence Scale, Adolescent Version (MEIS). This was a competence-based measure assessing an individual's ability to perceive, understand, and manage emotion. Logistic regression models were fit to test interactions between EI and ever trying cigarettes, hostility, and perceived ability to refuse a cigarette from someone just met, on intentions to smoke in the next year. Results High EI adolescents were more likely to intend to smoke in the next year if they had previously experimented with smoking. Those with low EI were more likely to intend to smoke if their perceived ability to refuse a cigarette offer from a person they just met was low or hostility level was high. Conclusions These preliminary results indicate that EI interacts with risk factors to reduce smoking intentions, and contributes evidence to a link between EI and smoking in adolescents.
Tracking with RFID asynchronous measurements by particle filtering

This paper deals with the problem of real-time indoor tracking of tagged objects in Ultra High Frequency Radio Frequency Identification systems with asynchronous measurements. A new and more realistic model of the system is proposed, where the probability of detecting a tag by a reader is described by a function of both the distance and the angle between the tag and the reader's antenna. The model also accounts for the possibility of a tag being in a dead-zone where the tag cannot be detected. For tracking, we propose the use of the particle filtering methodology that takes into account the asynchronous nature of the measurements. The parameters for modeling the resulting system are obtained from real-world experiments and the performance of the algorithm is shown by extensive computer simulations.
Stability islands for doubly charged clusters below the kinetic critical size

Abstract We report the observation of doubly charged clusters below the kinetic critical size for Coulomb fission. Ultraviolet irradiation of cold, singly charged alkali-halide clusters efficiently generates the corresponding doubly charged clusters, allowing detection of a range of CsI and KBr clusters above and below the critical size, n c =19. These include an island of particularly high stability, n =12–13, that can be explained by computed structures. By varying the photon energy, we have also demonstrated the role of excess energy in determining fission decay rates.
Vectorlike weak currents, massive neutrinos, and neutrino beam oscillations

Abstract If the weak currents are vectorlike, the neutrinos will not be massless, and there will exist weak mixing angles for leptons, analogous to the Cabibbo angle for hadrons. Neutrino beams will oscillate in a similar way as K o -beams. The failure to observe a solar neutrino flux at the theoretically predicted rate can be interpreted as the consequence of these oscillations.
Generation and suppression of stimulated Brillouin scattering in single liquid droplets

Stimulated Brillouin scattering (SBS) from micrometer-sized single water and methanol droplets was observed with a Brillouin shift that varied within a range determined by the k-vector spread and the optical feedback provided by the droplet interface. The inability to observe SBS in carbon disulfide droplets is attributed to phase-modulation broadening of the input and Brillouin radiation resulting from the large intensity-dependent index of refraction of carbon disulfide.
A hollow-cone dark-field study of interlayer cracks in delaminated HCa2Nan-3 NbnO 3n+1 materials

We investigate the blister features that appear in small-angle hollow-cone dark-field images of overlapping layers of delaminated calcium niobate. Modelling shows that the blister contrasts are caused by pockets of gas or liquid that have become trapped when calcium niobate layers are brought into contact and reseal. Hollow-cone dark-field contrast is primarily due to diffraction variations caused by sheet bending around the pressurized cracks.
Evaluation of an Osmonics® spiral-wound cross-flow filtration system for sub-μm sampling of Cd, Cu and Ni in seawater

Abstract A 1-kDa (1 kDa = 1000 daltons) Osmonics spiral-wound cross-flow filtration (CFF) membrane has been evaluated for sampling Cd, Cu and Ni in 1-kDa fractions of prefiltered seawater. Size-fractionated samples were collected as part of a CFF intercomparison experiment (Buesseler et al., 1996-this issue) and in the Gulf of Maine. Mass-balance results averaged 93 ± 6% (Cd), 81 ± 19% (Cu), and 99 ± 18% (Ni) for the intercomparison experiment and 56 ± 17% (Cd), 119 ± 38% (Cu), and 91 ± 6% (Ni) for the Gulf of Maine samples. Differences in mass balance between these studies may be related, in part, to removal of sub-μm particles and associated trace metals during prefiltration. An Amicon CFF system showed higher (2–12 ×) colloidal concentrations for Cu and Ni compared to Filtron and Osmonics systems; all CFF systems showed similar Cd, Cu and Ni mass-balance results. A model based on particle impaction with a filter shows the potential for adsorption of sub-μm particles by a 1-kDa Osmonics CFF membrane and conventional (Nuclepore) filters.
A carbon-13 NMR study of some sulfur-containing organic compounds

Carbon-13 NMR spectra have been obtained and analyzed for a series of saturated linear and cyclic sulfur-containing organic molecules. For the large cyclic polythiaethers whose proton spectra are broad and unresolved, it is found that carbon-13 spectra are sharp and well resolved. The resonances of all carbons fall within the expected chemical shift ranges. Based upon the comparative resolution in the spectra of large and small cyclic species, it is concluded that whatever conformational motion may exist within the rings must be occurring very rapidly on the NMR time scale.
Evaluation of the right ventricle by magnetic resonance imaging.

Abstract The ability of magnetic resonance imaging to evaluate right ventricular architecture and size was assessed in 149 subjects (26 normal volunteers and 123 patients with heart disease). The right ventricular myocardium was clearly delineated from adjacent structures in all patients. The trabeculated pattern of the right ventricle was well seen and was most evident during systole and in patients with right ventricular hypertrophy. The moderator band was diecernible in 72% of the subjects, whereas smaller muscular structures such as the papilliary muscles were identified less frequently. Magnetic resonance imaging provided a good image of the tricuspid valve leaflets but did not show the pulmonic leaflets well. The clear visualization of the endocardial and epicardial borders obtained with magnetic resonance imaging allowed measurement of wall thickness and of the internal dimensions of the cavity in normal subjects, in patients with moderate to severe systolic overload, and in patients with moderate to severe diastolic overload. Patients with severe systolic overload of the right ventricle had markedly thicker walls when compared with patients without this condition. The mean internal dimension at end diastole of patients with severe diastolic overload of the right ventricle was significantly increased when compared to other subgroups. Magnetic resonance imaging provides tomographic images of the right ventricle with clear distinction of the endocardial and epicardial surfaces that can be useful for quantitative and qualitative assessment of this complex structure.
Historical and Current Highlights in Radiation Biology: Has Anything Important Been Learned by Irradiating Cells?

Abstract Bedford, J. S. and Dewey, W. C. Historical and Current Highlights in Radiation Biology: Has Anything Important Been Learned by Irradiating Cells? Radiat. Res. 158, 251–291 (2002). Around 30 years ago, a very prominent molecular biologist confidently proclaimed that nothing of fundamental importance has ever been learned by irradiating cells! The poor man obviously did not know about discoveries such as DNA repair, mutagenesis, connections between mutagenesis and carcinogenesis, genomic instability, transposable genetic elements, cell cycle checkpoints, or lines of evidence historically linking the genetic material with nucleic acids, or origins of the subject of oxidative stress in organisms, to name a few things of fundamental importance learned by irradiating cells that were well known even at that time. Early radiation studies were, quite naturally, phenomenological. They led to the realization that radiations could cause pronounced biological effects. This was followed by an accelerating expa...
Teaching neuroimages: "pancake-like" gadolinium enhancement suggests compressive myelopathy due to spondylosis.

A 41-year-old man developed progressive bilateral hand weakness and spastic paraparesis. MRI demonstrated cord edema and “pancake-like” gadolinium enhancement (figure). Inflammatory/neoplastic causes were investigated and not found. He continued to deteriorate despite empiric corticosteroid treatment. One year later, cervical decompression stabilized his clinical condition but intramedullary T2 signal worsened. Persistent enhancement raised concern about alternative diagnoses.
Molecular biological tools to detect fish pathogens

Multiple approaches to control viral infections in fish are being employed on an experimental basis in many fish disease laboratories. They include techniques to monitor fish populations for viruses by tissue culture infectivity, tagged antibody reagents to detect viral proteins, and nucleic acid probes for in situ hybridization or polymerase chain reaction amplification. The specificity and resolution of these detection methods are being constantly improved to increase their ease-of-use and sensitivity. In addition, scientists are developing prophylactic treatments in the form of traditional vaccines and subunit, peptide and genetic vaccines using molecular biological techniques. The success of all these approaches is obviously dependent on an understanding not only of the molecular structure of the virus and its genome but on the pathogenic mechanisms that lead to disease in the host animal as well. It is at this level, where there is so little known, that the formulation of appropriate control strategies has been difficult. For example, molecular techniques have provided evidence that the survivors of infection with infectious haematopoietic necrosis virus are long-term carriers of the virus. This finding raises questions regarding the policy of releasing anadromous fish that have survived the disease. Viral vaccines have been shown to work in preventing virus-induced mortalities in rainbow trout fry in laboratory trials, but no determination has been made on whether vaccination also prevents the formation of a virus-carrier state in the survivors. More importantly, is there a vaccine formulation that will prevent carrier formation?
Effects of moderate decompression stress upon plasma potassium and glucose in the adrenalectomized cat.

Under conditions of moderate decompression stress (exposure to a simulated altitude of 28,000 feet for 60 minutes), intact cats showed a decrease in plasma potassium concentration from 4.42 m.eq./L. to 3.04 m.eq./L. and an increase in plasma glucose from an initial value of 94 mg.% to 354 mg.%. Chronically adrenalectomized cats, maintained on cortisone and DCA, exhibited, under similar conditions, a reduction in plasma potassium from 4.85 m.eq./L. to 3.65 m.eq./L. and a rise in plasma glucose from 103 mg.% to 286 mg.%. No significant difference was found between the plasma potassium or glucose responses of the two groups. Cats in moderate adrenal insufficiency demonstrated similar changes, plasma potassium decreasing from 6.04 m.eq./L. to 4.84 m.eq./L. and plasma glucose rising from 101 mg.% to 272 mg.%. On exposure of adrenalectomized cats maintained on supportive therapy to conditions of severe decompression stress (40–45,000 feet), however, plasma potassium concentration rose markedly to almost twice t...
Tidal heating of terrestrial extrasolar planets and implications for their habitability

The tidal heating of hypothetical rocky (or terrestrial) extrasolar planets spans a wide range of values depending on stellar masses and initial orbits. Tidal heating may be sufficiently large (in many cases, in excess of radiogenic heating) and long-lived to drive plate tectonics, similar to the Earth's, which may enhance the planet's habitability. In other cases, excessive tidal heating may result in Io-like planets with violent volcanism, probably rendering them unsuitable for life. On water-rich planets, tidal heating may generate subsurface oceans analogous to Europa's with similar prospects for habitability. Tidal heating may enhance the outgassing of volatiles, contributing to the formation and replenishment of a planet's atmosphere. To address these issues, we model the tidal heating and evolution of hypothetical extrasolar terrestrial planets. The results presented here constrain the orbital and physical properties required for planets to be habitable.
Idaho National Laboratory Experimental Program to Measure the Flow Phenomena in a Scaled Model of a Prismatic Gas-Cooled Reactor Lower Plenum for Validation of CFD Codes

The experimental program that is being conducted at the Matched Index-of-Refraction (MIR) Flow Facility at Idaho National Laboratory (INL) to obtain benchmark data on measurements of flow phenomena in a scaled model of a prismatic gas-cooled reactor lower plenum using 3-D Particle Image Velocimetry (PIV) is presented. A description of the scaling analysis, experimental facility, 3-D PIV system, measurement uncertainties and analysis, experimental procedures and samples of the data sets that have been obtained are included. Samples of the data set that will be presented include the mean velocity field in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic gas-cooled reactor (GCR) similar to a General Atomics Gas-Turbine-Modular Helium Reactor (GTMHR) design. This experiment has been selected as the first Standard Problem endorsed by the Generation IV International Forum. The flow in the lower plenum consists of multiple jets injected into a confined cross flow — with obstructions. The model consists of a row of full circular posts along its centerline with half-posts on the two parallel walls to approximate flow scaled to that expected from the staggered parallel rows of posts in the reactor design. The model is fabricated from clear, fused quartz to match the refractive-index of the mineral oil working fluid. The benefit of the MIR technique is that it permits high-quality measurements to be obtained without locating intrusive transducers that disturb the flow field and without distortion of the optical paths. An advantage of the INL MIR system is its large size which allows obtaining improved spatial and temporal resolution compared to similar facilities at smaller scales. Results concentrate on the region of the lower plenum near its far reflector wall (away from the outlet duct). Inlet jet Reynolds numbers (based on the jet diameter and the time-mean average flow rate) are approximately 4,300 and 12,400. The measurements reveal developing, non-uniform flow in the inlet jets and complicated flow patterns in the model lower plenum. Data include three-dimensional vector plots, data displays along the coordinate planes (slices) and charts that describe the component flows at specific regions in the model. Information on inlet velocity profiles is also presented.© 2008 ASME
'Helpfulness' in online communities: a measure of message quality

Online communities displaying textual postings require measures to combat information overload. One popular approach is to ask participants whether or not messages are helpful in order to then guide others to interesting content. Adopting a well-established framework for assessing data quality, we examine the nature of "helpfulness."We study consumer reviews at Amazon.com, deriving 22 measures quantifying their textual properties, authors' reputations and product characteristics. Confirmatory factor analysis reveals five underlying quality dimensions representing reviewers' reputations in the community, the topical relevancy of the reviews, the ease of understanding them, their believability and objectivity. A correlation and regression analysis confirms that these dimensions are related to the helpfulness scores assigned by community participants. However, it also uncovers a strong relationship between the chronological ordering of reviews and helpfulness, which both community participants and designers should keep in mind when using this method of social navigation.
Sex Differences in Given Name Preferences

When asked to list preferences for boys' and girls' names, 92 male college students were more likely than were 222 females to select common or dated names but less likely to opt for unusual or currently popular names. Other sex differences in naming preferences were discussed.
Impaired renal function is not associated with increased volume of intracerebral hemorrhage.

Background Patients with low glomerular filtration rate (GFR) are at risk for hemorrhagic stroke and experience poor long-term outcomes after stroke. These associations may be mediated by hematoma volume. We investigated the relationship between impaired renal function (GFR Methods Consecutive patients admitted with spontaneous intracerebral hemorrhage (sICH) between August 2006 and January 2010 were evaluated; patients with acute kidney injury or end stage renal disease were excluded. Data on patient demographics, admission creatinine, size and location of bleed, and disposition at discharge were collected. Hematoma size and location and discharge outcomes were compared among those with normal and impaired renal function. Results Among 573 patients admitted with sICH, 411 met our study criteria (mean age 61.4 years; 52.3% female; median ICH volume 11.2 mL). Mean GFR was 73.8 mL/min/1.73 m2, and 99 patients (24.1%) had a GFR Conclusions In a large sICH cohort, impaired renal function was not associated with final hematoma volume. Additional study should focus on the mechanism by which renal function impacts functional outcomes after sICH.
Specific binding of aminoglycoside antibiotics to RNA.

Abstract Background: Aminoglycoside antibiotics interfere with ribosomal protein synthesis and with intron splicing. Various lines of evidence suggest that RNA is the molecular target for amino glycosides, but little is known about the recognition process. Is recognition of a particular aminoglycoside specific for certain RNA structures? If so, what are the rules for recognition? We have begun to investigate this problem by in vitro selection of RNA molecules that can specifically bind to the aminoglycoside antibiotic tobramycin. Results: An RNA diversity library was used to select for sequences capable of binding to the aminoglycoside antibiotic tobramycin. After six cycles of selection, 82% of the RNA bound to tobramycin specifically. The selected RNA was reverse-transcribed into DNA, which was then cloned. At low selection stringency, an extremely large number of clones, on the order of 10 7 , produced RNAs capable of binding tobramycin with Kds in the μM range (values similar to that observed for the binding of tobramycin to Escherichia coli ribosomes). Sequencing of 18 of the clones revealed no obvious consensus sequence. At higher selection stringencies (K d s in the nM range) only two consensus sequences for binding were observed. Conclusions: We have shown that RNA molecules can be readily selected that bind the aminoglycoside tobramycin. The RNAs that bind tobramycin with high affinity contain consensus binding regions that may be confined to predicted stem-loop structures. These studies open the way for understanding the basis of RNA-aminoglycoside recognition.
Three-Dimensional Structure of the Gap Junction Connexon

The gap junction membrane channel is composed of macular aggregations of intercellular channels permitting the direct intercellular transfer of ions and small molecules. Each intercellular channel is formed by the apposition of two hexameric transmembrane channels (connexons), one from each cell. The interlocking of the two channels occurs extracellularly in a narrow 3.5-nm "gap" separating the junctional membranes. The channel-channel interaction is known to be selective between members of the family of proteins, called connexins, which oligomerize into the connexons. In addition to selectivity, the molecular interfaces involved in the extracellular interactions between connexons must be very congruent, since the intercellular channel must provide high resistances to the leakage of small ions between the channel lumen and the extracellular space. By using a recently developed biochemical procedure for obtaining ordered arrays of connexons from gap junctions split in the extracellular gap, (Ghoshroy, S., D. A. Goodenough, and G. E. Sosinsky. 1995. Preparation, characterization, and structure of half gap junctional layers split with urea and EGTA. J. Membr. Biol. 146:15–28) a three-dimensional reconstruction of a connexon has been obtained by electron crystallographic methods. This reconstruction emphasizes the structural asymmetry between the extracellular and cytoplasmic domains and assigns lobed structural features to the extracellular domains of the connexon. The implication of our hemichannel structure is discussed in relation to the in vivo state of unpaired connexons, which have been shown to exist in the plasma membrane.
ADAPTATION IN MYOSIN EXPRESSION OF AVIAN SKELETAL MUSCLE AFTER WEIGHTING AND UNWEIGHTING

Stretch-induced hypertrophy of the quail anterior latissimus dorsi is associated with decreased slow myosin 1 and increased slow myosin 2 expression and a small increase in expression of fast myosins. Because reduced neural activity has also been shown to accelerate expression from slow myosin 1 to slow myosin 2, we tested whether the increased expression of slow myosin 2 would be maintained when stretch was removed during a time when muscle activity would not be expected to increase. Quail anterior latissimus dorsi muscles were examined after 0-30 days of stretch overload and after 30 or 60 days of unweighting following 30 days of stretch. As expected, slow myosin 2 expression increased and slow myosin 1 expression decreased after 14-30 days of stretch. Novel findings were that slow myosin 1 and slow myosin 2 returned to control levels after unweighting. Furthermore, the expression of developmental and fast myosin heavy chains were evident by day 7, and maintained throughout wing unweighting. These data are consistent with the hypothesis that alterations in fast and developmental myosin expression result from formation and subsequent maintenance of new fibres during hypertrophy and regression. The relative amount and expression of myosin appears dependent upon mechanical stretch in the anterior latissimus dorsi muscle.
Endoscopic therapy of sclerosing cholangitis

The efficacy of endoscopic treatment in primary sclerosing cholangitis has not been clearly established. This report presents endoscopic intervention in 53 consecutive patients with this disorder. Pertinent data were abstracted from the GI-TRAC database, medical records, and cholangiograms, and clinical follow-up was obtained by telephone interview of the subjects. Assessed treatment outcomes were clinical symptom, liver function test, and cholangiographic appearance. Between 1986 and 1993, 85 patients with primary sclerosing cholangitis underwent successful ERCP, of which 36 men and 17 women underwent 100 therapeutic endoscopic procedures. Forty-three of 50 dilations, 37 of 38 stentings, 8 of 8 nasobiliary tube placements, and 11 of 17 stone extractions were technically successful. These treatments were complicated by cholangitis or pancreatitis in 15 patients. Clinical follow-up was obtained in 50 of 53 patients who had undergone 85 procedures (median follow-up of 31 months): 28 patients felt better, 21 felt the same, and 1 felt worse. Liver function tests obtained within 3 months of the endoscopic treatment were significantly improved compared with pretreatment values (P < .001). Cholangiograms showed improvement in 36% of the patients, no change in 51%, and the effect of therapy could not be assessed in 13%. Overall, 41 of 53 patients (77%) had improvements of their clinical symptoms, liver function tests, or cholangiograms.
Astronomy and ceremony at Chankillo: an Andean perspective

The towers, plazas, and fortified temple of Chankillo are analyzed within the context of Central Andean culture. Throughout the cultural area, staircases were apparently the scenes of ritual procession, perhaps mimicking shamanic-like movement between the three worlds. The double stairways of the thirteen towers of Chankillo may have been designed for ritual movement. The gradual rotation of the successively higher towers suggests shamanic ascent between the terrestrial and solar realms. The major astronomical feature of Chankillo is its solar axis, oriented to December solstice sunrise and June solstice sunset. Along this axis, to the east and west of the towers, there are prominent plazas in which public ceremonies may have been staged, particularly at the time of June solstice sunset. Celebrants who reached the highest tower on sunset of June solstice would have been silhouetted by the setting sun as viewed by spectators in the eastern plaza just below the tower. In the large plaza west of the towers, a similar public ceremony could have been associated with setting of the June solstice sun over the Temple of the Pillars to the west of the towers. The thirteen towers may have been stations of the moon for public ceremonies during the bright half of the lunar cycle. The presence of Spondylus shells suggests lunar ritual. The duality of private/public ritual, evident at Chavin and elsewhere, may have been present at Chankillo where public ceremonies may been observed from the plazas, while more restricted ceremonies may have occurred behind the walls of the fortified temple. If a horizon calendar had been developed using the profiles of the thirteen towers, it appears to have been an unintended consequence of the initial design of the towers. The monumental size of the towers is incommensurate with the small putative observing stations. The June solstice sun misses the lowest tower by 7 solar diameters, which would have been an unacceptable error if the tower had been built originally to mark June solstice. Another unsatisfactory feature would have been the equal spacing of the towers. If a meaningful calendar had been desired that marked divisions of the year perhaps based upon the moon, it would have involve variable spacing of the towers, with the largest spacing around equinox.
Laser Radar Imager Based on 3D Integration of Geiger-Mode Avalanche Photodiodes with Two SOI Timing Circuit Layers

A 64times64 laser-radar (ladar) detector array with 50mum pixel size measures the arrival times of single photons using Geiger-mode avalanche photodiodes (APD). A 3-tier structure with active devices on each tier is used with 227 transistors, six 3D vias and an APD in each pixel. A 9b pseudorandom counter in the pixel measures time. Initial imagery shows 2ns time quantization
Systolic architectures for polynomial and polynomial matrix manipulations

Manipulations of polynomials and polynomial matrices, basic to the polynomial equation approach to control system design, are dissected in a manner suitable for repeatable, rhythmic solution. These solutions are then implemented on systolic arrays. An introduction to a systematic design and analysis procedure for systolic arrays, along with an example, concludes the paper.
Carl Latkin on Mukta Sharma and Anindya Chatterjee's "Failure of substance use interventions: perspectives from Asia".

The paper by Mukta Sharma and Anindya Chatterjee documents the dearth of effective treatments for substance abuse and misuse and the complete failure of a criminal justice approach to effectively a...
Effects of substance P on the binding of agonists to the nicotinic acetylcholine receptor of Torpedo electroplaque.

: Abstract: The effect of the neuropeptide substance P on the binding of the cholinergic ligands to the nicotinic acetylcholine receptor of Torpedo electroplaque membranes was examined at a physiological concentration of NaCl (150 mM). Substance P had no effect on the initial rate of 125I-α-bungarotoxin binding at concentrations of <100 μM. The peptide did not bind to the high-affinity local anesthetic site but allosterically modulated [3H]phencyclidine binding, positively in the absence of agonist and negatively in the presence of agonist. Substance P increased the apparent affinity of the cholinergic agonists carbamylcholine and acetylcholine at equilibrium. The effect of substance P on the equilibrium binding of [3H]acetylcholine was examined directly, and the peptide appeared to increase the affinity of the binding of the second molecule of agonist, with no effect on the binding of the first. This indicates that substance P can affect the cooperative interactions between agonist binding sites. Substance P appeared to increase the rate of carbamylcholine-induced desensitization; however, the data are also consistent with an allosteric mechanism that does not involve the desensitized state. To attempt to differentiate between these mechanisms, the rates of recovery were determined after exposure to peptide and/or agonist. The kinetics of recovery are consistent with stabilization of the desensitized state by substance P if the peptide remains bound long enough to allow rapid recovery to the low-affinity state. However, an allosteric modulation of agonist binding that does not involve the desensitized state cannot be ruled out.
Mechanical Behavior of Hierarchical Synthetic Composites

Diverse microstructures observed in rigid natural composites have been linked to mechanical properties that are equal to and, at times, superior to those which have been designed into synthetic composite materials comprised of organic, metallic, and ceramic constituents. The constitution, properties, and microstructures of the natural and synthetic materials are described, along with what is known and what is unknown about the constituent components, and interfaces. Hierarchical approaches to designing with and the mechanical analyses of both natural and synthetic composites will be described.
Usefulness of pH monitoring in predicting the survival status of patients with scleroderma awaiting lung transplantation

Abstract Background Patients with scleroderma and end-stage lung disease (ESLD) have a very high prevalence of gastroesophageal reflux disease (GERD). Because GERD has been associated with aspiration in those with ESLD, and because those with scleroderma are particularly prone to develop severe GERD, there is some concern that GERD may contribute to shorten survival in patients with scleroderma awaiting lung transplantation. Therefore, we hypothesized that esophageal pH monitoring could predict survival of those with scleroderma and ESLD awaiting lung transplantation and that the severity of reflux can impact survival. Methods We conducted a retrospective analysis of all scleroderma patients referred for lung transplantation who underwent esophageal manometry and pH monitoring since August 2008. We identified 10 patients in whom we calculated and compared the area under the curve for each receiver operating characteristic curve of the following variables: DeMeester score, forced expiratory volume in 1 s (FEV1), %predicted FEV1, forced vital capacity (FVC), %predicted FVC, diffusion capacity for carbon monoxide (DL co ), and %predicted DL co . Results The DeMeester score nominally outperformed FEV 1 , FVC, and DL co . Receiver operating characteristic curve analysis was also used to define the optimal DeMeester score (65.2) in differentiating survival status, as determined by maximizing sensitivity and specificity. Based on this value, we calculated the 1-y survival from the time of the esophageal function testing, which was 100% in seven patients with a DeMeester score of 65.2 ( P = 0.01). The latter patients had greater total time pH 70 had also proximal reflux, underwent antireflux surgery, and is alive 1201 d after transplant. Conclusions Our study shows that esophageal pH monitoring can predict survival status in patients with scleroderma awaiting lung transplantation and that the severity of reflux can impact the 1-y survival rate. Therefore, esophageal pH monitoring should be considered early in patients with scleroderma and ESLD, as this test could appropriately identify those in whom laparoscopic antireflux surgery should be performed quicker to prevent GERD and its detrimental effects in patients awaiting lung transplantation.
Formation and release of body scales in the Dinoflagellate genus Heterocapsa

Body scales in dinoflagellate species belonging to Heterocapsa developed in vesicles derived from the Golgi apparatus, but did not appear within the stacked Golgi cisternae. The membranes of the scale vesicles functioned as molds for the developing scales. Mature scales within expanded vesicles moved to the flagellar area, the site of release. Body scales were seen within the cytoplasm of Heterocapsa spp. fixed at various times in the light: dark cycle, suggesting that scales are formed and probably released continuously.
Factors Affecting Recovery After Acoustic Neuroma Resection

In order to determine which variables influence recovery from acoustic neuroma resection, acutely postoperative patients were divided into two groups and treated twice daily at bedside as inpatients at a tertiary care center. Treatment times were increased gradually from 5 to 30 min. Exercise subjects underwent passive and active head movements and walking with augmented head movements. Control subjects received attention without exercise. Pre- and post-tests included vertigo intensity and frequency, low-frequency vestibulo-ocular reflex (VOR), posturography and path integration. Post-tests were given at discharge and at approximately 4-week intervals for 3 months. Multilevel statistical analyses showed that neither group assignment nor age affected the outcome. All measures were abnormal at discharge but improved towards normal within 3 weeks. VOR on the unoperated side returned to normal values but on the lesioned side did not. Therefore, compensation is influenced by tumor size but not by age or early postoperative vestibular rehabilitation. Most compensation occurs within 3 weeks, probably due to central mechanisms, although some measures may not recover completely.
Reconstruction of genealogical relationships with applications to Phase III of HapMap

Motivation: Accurate inference of genealogical relationships between pairs of individuals is paramount in association studies, forensics and evolutionary analyses of wildlife populations. Current methods for relationship inference consider only a small set of close relationships and have limited to no power to distinguish between relationships with the same number of meioses separating the individuals under consideration (e.g. aunt–niece versus niece–aunt or first cousins versus great aunt–niece). Results: We present CARROT (ClAssification of Relationships with ROTations), a novel framework for relationship inference that leverages linkage information to differentiate between rotated relationships, that is, between relationships with the same number of common ancestors and the same number of meioses separating the individuals under consideration. We demonstrate that CARROT clearly outperforms existing methods on simulated data. We also applied CARROT on four populations from Phase III of the HapMap Project and detected previously unreported pairs of third-and fourth-degree relatives. Availability: Source code for CARROT is freely available at http://carrot.stanford.edu. Contact: sofiakp@stanford.edu