cssi/SciSciGPT-SciSciNet huggingface dataset:
Spontaneous decay of CdSe / ZnS core-shell quantum dots at the air-dielectric interface

We report measurements of the fluorescence decay times of CdSe/ZnS core-shell quantum dots at the air-dielectric interface for several dielectrics with different refractive indices. The results are in agreement with a simple theory that accounts for the impact of the refractive index on the density of states and magnitude of the vacuum field, as well as for the local-field correction inside the quantum dot. The results suggest that, by embedding the quantum dots into a high-index dielectric material, one can reduce the spontaneous decay time to sub-nanosecond scale while preserving high quantum efficiency.
Modeling Trichloroethylene Adsorption by Activated Carbon Preloaded with Natural Dissolved Organic Matter Using a Modified IAST Approach

A model was developed, using an approach based on the Ideal Adsorbed Solution Theory (IAST), to predict trichloroethylene (TCE) adsorption by granular activated carbon (GAC) preloaded with natural dissolved organic matter (DOM) isolated from three surface water sources. The IAST model was formulated for a bi-solute system in which TCE and DOM single-solute uptakes were described by the Langmuir-Freundlich and Freundlich isotherms, respectively. The effect of DOM molecular size and polarity (as measured by XAD 8 resin fractionation) on TCE uptake by preloaded GAC was assessed to identify a reactive fraction of natural water DOM for the purpose of modeling competitive adsorption. Consistent with previous work that identified low molecular weight species as the most reactive with regard to preloading effects (i.e., reducing target compound uptake), the low molecular weight components of the polar (hydrophilic) and nonpolar (hydrophobic) DOM fractions, isolated using ultrafiltration (1 kDa molecular weight cutoff membrane), exhibited significant competitive effects. Furthermore, the effects of these fractions on TCE uptake were similar; therefore, theywere considered together to represent a single "reactive fraction" of DOM. On the basis of this finding, isotherms for the <1 kDa low molecular weight DOM fraction of the whole water were measured, and molar concentrations were computed based on an average molecular weight determined using size-exclusion chromatography. The IAST model was modified to incorporate surface area reduction due to pore blockage by DOM and to reflectthe hypothesis thatTCE molecules can access adsorption sites which humic molecules cannot, thus preventing competition on these sites. The model was calibrated with data for TCE uptake by carbon preloaded with the <1 kDa low molecular weight DOM fraction and was verified by predicting TCE uptake by carbon preloaded with whole natural waters for both constant GAC dose (hence constant DOM loading) and variable GAC dose (hence variable DOM loading) TCE isotherms. Preloading by DOM reduced volume in GAC pores having widths smaller than 1.25 nm (likely accessible only to TCE) to a greater extent than total pore volume, suggesting preferential blockage of micropores. Such preferential pore blockage may explain, in part, why increased DOM loading decreases the fraction of the total surface area on which no competition between TCE and DOM occurs.
Use of nitric oxide for treatment of pulmonary hypertensive crisis in a child after protamine administration.

A B a ROTAMINE ADMINISTRATION may cause systemic hypotension, pulmonary hypertension, anaphylactic shock, nd cardiovascular collapse.1,2 These adverse reactions are ore commonly reported in adults than in children. In one ecent pediatric study,3 the only adverse reaction noted was ystemic hypotension. Because severe pulmonary hypertension as rarely been noted in children after heparin reversal, the uthors report a pulmonary hypertensive crisis in a child after rotamine administration, which was successfully treated with itric oxide (NO).
Heat stability studies at the alpha-glycerophosphate dehydrogenase locus in populations of Drosophila melanogaster.

The level of hidden variation in populations of Drosophila melanogaster at the Gpdh+ locus was determined by thermal stability studies of the protein. The results indicate a lack of variation using these methods both in and between the two common electrophoretic variants. It is suggested that α-GPDH is conserved in primary structure, which may be related to its critical role in flight muscle metabolism.
Phasic Nucleus Accumbens Dopamine Release Encodes Effort- and Delay-Related Costs

Background Optimal decision-making requires that organisms correctly evaluate both the costs and benefits of potential choices. Dopamine transmission within the nucleus accumbens (NAc) has been heavily implicated in reward-learning and decision-making, but it is unclear how dopamine release might contribute to decisions that involve costs. Methods Cost-based decision-making was examined in rats trained to associate visual cues with either immediate or delayed rewards (delay manipulation) or low-effort or high-effort rewards (effort manipulation). After training, dopamine concentration within the NAc was monitored on a rapid time scale with fast-scan cyclic voltammetry. Results Animals exhibited a preference for immediate or low-effort rewards over delayed or high-effort rewards of equal magnitude. Reward-predictive cues but not response execution or reward delivery evoked increases in NAc dopamine concentration. When only one response option was available, cue-evoked dopamine release reflected the value of the future reward, with larger increases in dopamine signaling higher-value rewards. In contrast, when both options were presented simultaneously, dopamine signaled the better of two options, regardless of the future choice. Conclusions Phasic dopamine signals in the NAc reflect two different types of reward cost and encode potential rather than chosen value under choice situations.
A state-selective quasidegenerate perturbation theory for the electronic structure of molecules

Abstract A state-selective quasidegenerate second-order perturbation theory for the determination of the electronic structure of polyatomic molecules is presented. The tenability of the method is demonstrated by calculations on several well-known “benchmark” molecules: H 2 O, using a double zeta (DZ) basis set; the singlet—triplet and singlet—singlet energy separations of DZP CH 2 ; the excited states of DZP CH + 2 ; and the dissociations of F 2 and N 2 , using larger than DZP bases. The new method utilizes information available at the conclusion of a complete active space self-consistent field (CASSCF) calculation and is shown to improve CASSCF results.
Changing Childhood in Polynesia: The Impact of Robert Levy's Tahitians on Psychological Anthropology in Oceania

For over 75 years, Pacific Island societies have been sites of pioneering and significant research on culture, child socialization, and psychological development. With the publication of Robert Levy's Tahitians in 1973, psychological anthropology in the Pacific was transformed. His analysis of psycho-cultural patterns among Tahitians advanced our understanding of how child socialization mediates between the bio-psychological template and the socio-cultural world. In the decades following Levy's study, household economic practices in rural French Polynesia changed dramatically. This article examines the impact of this social transformation on familial relations and cultural practices within the family. In particular, Levy's theories are used to explore the impact of these changes for the construction of personal experience, affect, and thought among rural Tahitian children.
The effect of superoxide dismutase and catalase on metabolism of 3H-arachidonic acid by washed platelets

Previous experiments have suggested that superoxide dismutase (SOD) and catalase (CAT) may inhibit prostaglandin synthesis. The purpose of this study was to determine if these free radical scavengers can alter the metabolism of free arachidonic acid (AA) by the cyclooxygenasse and lipoxygenase enzyme systems in platelets. In control experiments washed platelets were incubated with 3H-AA for 5 minutes, extracted and the products separated by reverse phase high pressure liquid chromatography (HPLC). In normal intact platelets 13.5 ± 0.6% of the radioactivity was found in TxB2, 16.3 ± 1.4% in HHT, 61.3 ± 1.1% in 12-HETE and 9.0 ± 1.0% was unconverted AA. Pre-incubating the platelets for 1 minute with 10 μg/ml SOD or CAT or 10 μg/ml SOD plus 10 μg/ml CAT did not inhibit AA conversion or alter the percent product distribution. Similarly, SOD and CAT had no effect on AA metabolism in broken cells. However, as expected, pretreating platelets with indomethaoin blocked TxB2,and HHT formation (P <.0001). We conclude that SOD and CAT do not inhibit cyclooxygenase or lipoxygenase metabolism of free AA in platelets.
Full-field quantitative phase imaging

Full-field quantitative phase imaging provides useful endogenous contrast in a variety of biological specimens where contrast from other natural sources is small and the use of exogenous materials is undesirable. While the concepts of interferometric microscopy are simple and have long been known, diffculties in implementation have prevented this imaging modality from being exploited to its fullest capability. In recent years, as a result of improvements in lasers and light-delivery systems, cameras, and computational ability, new technologies have been developed to bring this capability within reach of a large number of users. Phase imaging presents some unique issues. For example ambiguities between amplitude and phase and ambiguities within a cycle of phase (eg. the cosine is an even function) require two measurements per pixel. Ambiguities in the number of cycles require phase unwrapping. More fundamentally, ambiguity between refractive index and thickness requires multiple views. Furthermore, coherent images tend to contain artifacts caused by multiple reflections from optical components, which require special attention to image processing. They also are more likely than incoherent images to include significant energy at high spatial frequencies, which can interact in complex ways with realistic optical transfer functions and discrete sampling. Different full-field quantitative phase imaging hardware and software are discussed, with attention to the practical limitations imposed by these considerations.
Stability and accuracy analysis of some fully-discrete algorithms for the one-dimensional second-order wave equation

The present investigation is concerned with some basic results for a predictor-multicorrector algorithm applied to the one-dimensional wave equation, giving particular attention to so-called 2-pass explicit schemes in which both lumped and coupled mass matrices are employed. In an assessment of the accuracy and stability properties of the algorithms, use is made of the one-dimensional, second-order wave equation. The maximum stable time step of the lumped right-hand-side mass, 2-pass explicit algorithm is twice that of the 1-pass explicit algorithm. Improved accuracy is obtained by employing higher-order, or consistent, right-hand-side, mass.
An X-ray powder diffraction study of the chloride-bromide systems of trivalent gadolinium, terbium, and ytterbium

Abstract The lanthanoid mixed halide systems, M Cl 3  M Br 3 , for M = Gd, Tb, and Yb, have been prepared by mixing and fusing the pure reactants and have been examined by X-ray powder diffraction procedures. For M = Gd, UCl 3 , ( P6 3 m )-, PuBr 3 ( Cmcm )- and AlCl 3 ( C2 m )- type solid solution regions were found. For M = Tb, PuBr 3 - and AlCl 3 -type solid solution regions were found. For M = Yb, AlCl 3 − and FeCl 3 -(R 3 )- type solid solution areas were observed. Pure TbBr 3 appears to be isostructural with GdBr 3 rather than with DyBr 3 . These systems are discussed and compared to related systems.
A gut feeling for microbes: getting it going between a parasite and its host

We do not live in a sterile environment, but instead we are intimately associated with our commensal microbiota. Benson et al. (2009) suggest that host sensing of these microbes takes a pivotal role in getting the immune system up and running in response to a major intestinal parasite.
Discharge properties of dorsal medullary inspiratory neurons in newborn pigs.

Abstract The discharges of medullary inspiratory neurons were recorded in newborn pigs. They were classified by (a) discharge pattern; (b) response to lung inflation; (c) synaptic relation to phrenic motoneurons. Our results showed: (a) these neurons have similar discharge patterns and responses to lung inflation as adult cats; (b) most neurons do not project to phrenic motoneurons. It is suggested that our sampled population of neurons is involved in integrating pulmonary afferent inputs.
Flow-induced vibrations of the SSME LOX inlet tee vanes

This paper describes the results of a program initiated to identify the cause and the mechanism of 4-kHz vibrations of the Space Shuttle main engine's (SSME's) LOX inlet tee, which were revealed in 17 percent of the SSMEs during ground tests. The results of the engines' inspection, structural analyses, computational fluid dynamics studies, literature reviews, expert consultations, and laboratory testings identified the probable cause of the 4-kHz vibrations being related to the fact that the walls of some tees were thinner than in the mojority of tees, resulting in less stiff structures. The mechanism of the vibrations was identified as vortex shedding in combination with a structural coupling with the thrust cone, which increased the vane mobility, which, in turn, aggravated the fluid coupling with the thrust cone. As a result, the vane mobility was increased, aggravating the fluid coupling with the vanes. An internal modification was developed and was successfully demonstrated on an engine that had previously exhibited a 4-kHz problem.
Geometrical characteristics of the pore space in a random packing of equal spheres

Abstract Tetrahedral tessellation is applied to an existing, computer-generated, random packing of nearly equal spheres.The vertices of each tetrahedron are the centers of four neighboring spheres.The objective is to identify the tetrahedral pores and then determine the geometrical characteristics of the pore space. The tessellation procedure begins with a seed tetrahedron. Then, in a crystal growth-like manner, tetrahedra are added one at a time to the seed until a cluster of non-overlapping, space-filling tetrahedra is formed. Each tetrahedron has a pore chamber and four constrictions, one on each of its four triangular faces. Statistical analysis allows the determination of pore size distribution, constriction size distribution as well as various correlations between (among) pores and (among) constrictions. It is shown that pores linked by a common constriction are rather close in size, while constrictions of the same pore tend to have more different sizes.
Robust Automatic Parallel Parking in Tight Spaces via Fuzzy Logic

This paper develops and experimentally demonstrates a robust automatic parallel parking algorithm for parking in tight spaces. Novel fuzzy logic controllers are designed for each step of the maneuvering process. The controllers are flrst demonstrated by simulation using the kinematic model of a skid steering autonomous ground vehicle (AGV). They are then demonstrated experimentally on a skid steering AGV and it is shown that the developed algorithm has the ability to parallel park AGVs in tight spaces under both vehicle localization errors and parking space detection errors. This paper also presents a genetic fuzzy system which uses a genetic algorithm’s learning ability to determine efiective parameters for the developed fuzzy logic controllers. The genetic fuzzy system is used to tune the fuzzy logic algorithm for both a skid steering AGV and a front-wheel steering AGV.
Analysis of CoQ10 in rat serum by ultra-performance liquid chromatography mass spectrometry after oral administration

A UPLC-MS method for determining Coenzyme Q(10) (CoQ(10)) levels in rat serum was developed. CoQ(10) was quantitatively extracted into 2-propanol using a fast extraction procedure. The separation of CoQ(10) was performed on a Waters Acquity UPLCtrade mark BEH C(18) column (1.7 microm, 1.0 mm x 50 mm) with the mobile phase containing acetonitrile, 2-propanol, and formic acid (90:10:0.1) over 5 min. The sensitivity of this method allows for the quantitation of 50 ng/mL CoQ(10) in serum (S/N=10). The linearity of this method was found to be from 50 to 20,000 ng/mL. The precision was less than 10% (intra- and inter-day), and the average extraction recovery was between 90 and 105%. This procedure provides a precise, sensitive and direct assay method for the determination of CoQ(10) in rat serum after oral administration. This method could be applied to further pharmacokinetic studies of CoQ(10).
Management of molecular-targeted therapy for chronic myelogenous leukemia.

Purpose To provide primary care providers with guidelines on the evaluation and management of treatment for patients with chronic myelogenous leukemia (CML) with emphasis on the molecular-targeted therapy imatinib mesylate. Data Sources Research-based articles in the medical literature, review articles, and clinical practice guidelines. Conclusions CML is a clonal stem cell disorder causing 5,000 new cases annually. Research on molecular-targeted therapy confirms that specific protein kinases have broad consequences for the development of hture drugs to treat CML. The most recent discovery is a new compound, imatinib mesylate, which has become commercially available. Currently, the standard of care for CML is this agent. This therapy has changed management strategies for treatment of patients with the diagnosis of CML. lmpilcatlons for Practice Long-term observations and evaluations are needed for final determination of treatment effectiveness; thus, primary care providers will follow patients with CML in the community. Unforeseen toxicity may surface, requiring accurate assessment and evaluation. Primary care providers will be actively involved with providing symptom management for these patients. SUMMARY A new compound has been developed that targets the diseased cells in CML and appears to spare normal cells (Savage & Antman, 2002). This selective-targeted therapy has the ability to inhibit the BCR-ABL tyrosine kinase enzyme, resulting in complete hemato-logic responses in 95% and major cytogenetic responses in 60% of the study subject patients with CML after a median follow-up of 18 months (see Table 1; Kantarjian et al., 2002). It is not yet known whether this new agent will kill the progenitor bone marrow stem cells that originally carry the Ph+ chromosome. Although a number of study subject patients obtained a complete remission, it is too early to determine whether the patients will ever be able to completely discontinue treatment. Patients may need to take the drug for the rest of their lives. A life-long commitment to a pill may be inconvenient, but the minimal side effects and lack of severe toxicities seen present a feasible option of treatment. Even though imatinib mesylate holds promise for the treatment of CML, several unanswered question remain: What is the optimal dose and length of therapy? How durable is the response? What are the late side effects or cumulative toxicities? When should patients use it, and should they use it alone or in combination with another agent. The final question remains: Can CML be cured with molecular-targeted therapy? All of these questions require further research. A randomized trial comparing imatinib mesylate to an interfer-on-based regimen in patients with newly diagnosed CML is ongoing, with early data suggesting the superiority of imatinib rnesylate to interferon therapy (Cortes et al., 2002).
Decreased activity of a soluble DNA-dependent RNA polymerase from thymus of rats injected with a thymolytic steroid

Abstract The Mg 2+ - and Mn 2+ - catalyzed DNA-dependent RNA polymerase activity of rat thymic nuclei has been solubilized by three procedures. The soluble preparation required addition of DNA for activity, indicating that endogenous DNA had been separated from the enzyme. Enzymatic activity solubilized from thymocytes of rats injected with either cortisol or fluocinolone acetonide 3 hr prior to sacrifice was significantly lower than that from cells of control rats. This decreased DNA-dependent RNA polymerase activity is due, at least in part, to an alteration in the enzymatic component of the DNA-RNA polymerase complex.
A combination HIV reporter virus system for measuring post-entry event efficiency and viral outcome in primary CD4+ T cell subsets

Fusion between the viral membrane of human immunodeficiency virus (HIV) and the host cell marks the end of the HIV entry process and the beginning of a series of post-entry events including uncoating, reverse transcription, integration, and viral gene expression. The efficiency of post-entry events can be modulated by cellular factors including viral restriction factors and can lead to several distinct outcomes: productive, latent, or abortive infection. Understanding host and viral proteins impacting post-entry event efficiency and viral outcome is critical for strategies to reduce HIV infectivity and to optimize transduction of HIV-based gene therapy vectors. Here, we report a combination reporter virus system measuring both membrane fusion and viral promoter-driven gene expression. This system enables precise determination of unstimulated primary CD4+ T cell subsets targeted by HIV, the efficiency of post-entry viral events, and viral outcome and is compatible with high-throughput screening and cell-sorting methods.
Carrier rates in the midwestern United States for GJB2 mutations causing inherited deafness.

ContextMutations in the GJB2 gene are the most common known cause of inherited congenital severe-to-profound deafness. The carrier frequency of these mutations is not known.ObjectivesTo determine the carrier rate of deafness-causing mutations in GJB2 in the midwestern United States and the prevalence of these mutations in persons with congenital sensorineural hearing loss ranging in severity from moderate to profound, and to derive revised data for counseling purposes.DesignLaboratory analysis, performed in 1998, of samples from probands with hearing loss for mutations in GJB2 using an allele-specific polymerase chain reaction assay, single-strand conformation polymorphism analysis, and direct sequencing.Setting and SubjectsFifty-two subjects younger than 19 years sequentially referred to a midwestern tertiary referral center for hearing loss or cochlear implantation, with moderate-to-profound congenital hearing loss of unknown cause, parental nonconsanguinity, and nonsyndromic deafness with hearing loss limited to a single generation; 560 control neonates were screened for the 35delG mutation.Main Outcome MeasurePrevalence of mutations in the GJB2 gene by congenital deafness status.ResultsOf 52 sequential probands referred for congenital sensorineural hearing loss, 22 (42%) were found to have GJB2 mutations. The 35delG mutation was identified in 29 of the 41 mutant alleles. Of probands' sibs, all homozygotes and compound heterozygotes had deafness. Fourteen of 560 controls were 35delG heterozygotes, for a carrier rate expressed as a mean (SE) of 2.5% (0.66%). The carrier rate for all recessive deafness-causing GJB2 mutations was determined to be 3.01% (probable range, 2.54%-3.56%). Calculated sensitivity and specificity for a screening test based on 35delG mutation alone were 96.9% and 97.4%, respectively, and observed values were 94% and 97%, respectively.ConclusionsOur data suggest that mutations in GJB2 are the leading cause of moderate-to-profound congenital inherited deafness in the midwestern United States. Screening of the GJB2 mutation can be offered to individuals with congenital deafness with high sensitivity and specificity by screening only for the 35delG mutation. A positive finding should establish an etiologic diagnosis and affect genetic counseling.
A system for continual quality improvement of normal tissue delineation for radiation therapy treatment planning.

Purpose To implement the "plan-do-check-act" (PDCA) cycle for the continual quality improvement of normal tissue contours used for radiation therapy treatment planning. Methods and Materials The CT scans of patients treated for tumors of the brain, head and neck, thorax, pancreas and prostate were selected for this study. For each scan, a radiation oncologist and a diagnostic radiologist, outlined the normal tissues ("gold" contours) using Radiation Therapy Oncology Group (RTOG) guidelines. A total of 30 organs were delineated. Independently, 5 board-certified dosimetrists and 1 trainee then outlined the same organs. Metrics used to compare the agreement between the dosimetrists' contours and the gold contours included the Dice Similarity Coefficient (DSC), and a penalty function using distance to agreement. Based on these scores, dosimetrists were re-trained on those organs in which they did not receive a passing score, and they were subsequently re-tested. Results Passing scores were achieved on 19 of 30 organs evaluated. These scores were correlated to organ volume. For organ volumes P =.005). Normal tissues that had the lowest scores included the lenses, optic nerves, chiasm, cochlea, and esophagus. Of the 11 organs that were considered for re-testing, 10 showed improvement in the average score, and statistically significant improvement was noted in more than half of these organs after education and re-assessment. Conclusions The results of this study indicate the feasibility of applying the PDCA cycle to assess competence in the delineation of individual organs, and to identify areas for improvement. With testing, guidance, and re-evaluation, contouring consistency can be obtained across multiple dosimetrists. Our expectation is that continual quality improvement using the PDCA approach will ensure more accurate treatments and dose assessment in radiotherapy treatment planning and delivery.
Ethical implications of the relationship of purpose to role and function in public relations

The move toward professionalism in public relations has led to a renewed concern over ethical principles. The Public Relations Society of America has made some progress toward this end through its Code of Professional Standards, yet the practice still falters on the fringes of professionalism. At least part of the problem is a lack of delineation of roles, functions and purpose and the lack of an ethical guideline which addresses this disparity. In the United States today, public relations is variously defined and its roles variously categorized. The difficult, often impossible, task of defining public relations has, in part, led to the difficulty of defining the role of ethics in the practice, which has forestalled progress toward its acceptance as a profession. Historically, the role of public relations as a practice has had three major interpretations: con trolling publics, responding to publics, and achieving mutually beneficial relationships among all publics (Newsom and Scott, 1985). Each of these interpreta tions has as its focus not roles or functions, but purpose or intent. Within the first interpretation lies the roots of the belief that all public relations is persuasive by nature. Within the last two are the seeds of modern public relations. And therein lies a problem, and a question. Should we apply different sets of ethical guidelines to the different and often
Coassembly of synthetic segments of shaker K+ channel within phospholipid membranes.

Increasing evidence suggests that membrane-embedded hydrophobic segments can interact within the phospholipid milieu of the membrane with varying degrees of specificity and thus contribute to the folding and oligomerization of proteins. We have used synthetic peptides corresponding to segments from the hydrophobic core of the Shaker potassium channel as a model system to study interactions between membrane-embedded segments. Three synthetic segments of the Shaker K+ channel, comprising the hydrophobic S2, S3, and S4 sequences, were used, and their secondary structure, their interactions with, and orientation within phospholipid membranes were examined. Secondary structure studies revealed that though S3 and S4 both adopt certain fractions of α-helical structures in membrane mimetic environments, the α-helical content of S3 is lower. Both S3 and S4 bind strongly to zwitterionic phospholipids, with partition coefficients in the order of 104 and 105 M-1. ATR-FTIR studies showed that while the S4 peptide is o...
Ways of knowing in clinical practice

Concepts developed by Polanyi regarding personal knowledge and the tacit dimension have particular relevance for social work clinicians. The concept of personal knowledge changes our understanding of the use of theories and points to the imprecision in our use of language. It leads to a relativistic view of knowledge through which the client's story is seen as a constructed narrative rather than a set of facts to be objectively recorded, therapeutic neutrality is considered a myth and difficult ethical questions about value differences and the clinician's influence over clients are brought to the fore.
Laser Self-Compensated Measurement for Glass Thickness Process Control in High Temperature Environment

This article analysis the characteristic of the actual production of the float glass in the tin bath under the environment. The author use the method of dynamic optical measurement to measure the thickness of the glass. The process use semiconductor as the light source and linear array CCD as the censor to get the data at 600°C. By analyzing large amount of dynamic experiment data and the analysis of the measuring equipment, using edge measuring and pixel subdivision technique on the software, the author have several discussions and come up with some compensate steps towards the effect of the accuracy of the system. Within the effective range of the thickness of glass from 2~20mm, the accuracy of dynamic online measurement can reach 5µm; the accuracy of the statics online measurement is less than 1µm.
Enzymic synthesis of polynucleotides. III. Phosphorolysis of natural and synthetic ribopolynucleotides.

Abstract 1. 1. Ribopolynucleotides can be classified into three groups according to their susceptibility to cleavage by polynucleotide phosphorylase of Azotobacter vinelandii: (a) rapidly phosphorolyzed; this group includes synthetic polynucleotides, such as polyadenylic or polyuridylic acid, containing only one kind of nucleotide; (b) slowly phosphorolyzed; this group includes synthetic (poly AGUC), yeast, and bacterial RNA, as well as the aggregate (poly A + U) formed by mixing solutions of poly-adenylic and polyuridylic acid; (c) phosphorolyzed at an intermediaterate; this is the case with tobacco mosaic virus RNA. The slow phosphorolysis of polynucleotides of group (b) can be related to the fact that, contrary to those of group (a), they consist largely of multistranded rather than single-stranded chains. In view of this, the intermediate rate of phosphorolysis of tobacco mosaic virus RNA might reflect a slight tendency of this compound to assume a multistranded structure. 2. 2. Adenylic acid tri- and tetranucleotides with 5′-phosphomonoester end groups, obtained by hydrolysis of polyadenylic acid with an enzyme from liver nuclei, are slowly phosphorolyzed by Azotobacter polynucleotide phosphorylase. 3. 3. The nucleoside 5′-diphosphates produced by phosphorolysis of tobacco mosaic virus RNA have been identified chromatographically.
Ground Water and Small Research Basins: An Historical Perspective

Scientists have been studying hydrological processes within a watershed context for hundreds of years. Throughout much of that history, little attention was paid to the significance of ground water; in nearly all early studies, ground water was never considered. In many recent studies, ground water fluxes are assumed to be insignificantly small. The following is a brief history of the evolution of watershed studies, including the recent increase in interest regarding the influence of ground water on the hydrology and geochemistry of research watersheds.
A Convenient Procedure for Dissolving Metal Reductions

Abstract Alicyclic α,β-unsaturated ketones react with lithium in ethylenediamine, followed by Jones oxidation, to give cyclic ketones in good yield. The stereoselectivity at the β position parallels that observed with lithium in liquid ammonia.
Some results for one iterated projection of the symmetric schubert update

Abstract A new sparse symmetric quais-Newton update, recently suggested by Dennis and Schnabel[1] and called one iterated projection of the symmetric Schubert update, is studied. We present some numerical results for this update when it is used in sparse unconstrained minimization calculations. These numerical results, together with the convergence analysis given in[2], provide strong reasons for using one iterated projection of the symmetric Schubert update, instead of the sparse Powell-symmetric-Broyden (PSB) update, in sparse unconstrained optimization calculations. We also briefly discuss a recent application of the Dennis and Schnabel update in equation oriented process optimization.
Finite dimensional exponential attractors for semilinear wave equations with damping

Abstract We consider the initial value problem for a class of second order evolution equations that includes, among others, the 3D sine-Gordon equation with damping and the 3D Klein-Gordon type equations with damping. We show the existence of a set with finite fractal dimension that contains the global attractor and attracts all smooth solutions at an exponential rate.
A.P.13

Disordered lysosomal function within muscle cells is the basis for a group of diseases referred to as autophagic vacuolar myopathies. These disorders include acid maltase deficiency (Pompe disease), LAMP-2 deficiency (Danon disease), and X-linked myopathy with excess autophagy (XMEA). We present a 65 year old diabetic woman with bilateral leg weakness evolving over 2 years to the point she was unable to ambulate without assistance. There was no family history of a similar disorder. She had prominent weakness in her legs proximally > distally while arms and bulbar muscles had normal strength. Mild percussion myotonia of forearm muscles was present but not hand grasp myotonia. CK was 914. Acid alpha-glucosidase activity was normal. Nerve conduction studies showed evidence of a largely axonal neuropathy likely related to her poorly controlled diabetes. Needle exam demonstrated fibrillations and frequent short duration myotonic discharges in arm and leg muscles. Quadriceps muscle biopsy showed basophilic cytoplasmic stippling within myofibers that corresponded to small vacuoles discernable by enzyme histochemical staining for acetylcholinesterase and immunostaining for dystrophin and other sarcolemmal proteins. Cytoplasmic clusters of lysosomes and autophagosome extrusion with duplication of basement membranes were observed with electron microscopy. The biopsy findings are those of an autophagic vacuolar myopathy, the underlying nature of which has not been defined. Frequent short duration myotonic discharges were a remarkable feature. The presence of myotonic discharges has been previously reported to occur in patients with Pompe disease, Danon disease, and XMEA. These discharges indicate hyperexcitability of the muscle membranes and may reflect structural sarcoplasmic changes. Their occurrence in the various disorders involving autophagy suggests that short myotonic discharges may be a diagnostically useful electrophysiologic marker for this group of disorde.
X-ray microbeam measurements of subgrain stress distributions in polycrystalline materials

Abstract Three-dimensional (3D) measurements of strain tensor distributions with subgrain resolution are now possible due to an emerging class of instrumentation: the 3D X-ray crystal microscopes. These instruments combine ultra-intense synchrotron X-ray sources and advanced X-ray optics to probe polycrystalline materials with submicron spatial resolution. By employing polychromatic X-ray beams and a virtual pinhole camera method, called differential aperture microscopy, 3D distributions of the local crystalline phase, orientation (local texture) and elastic and plastic strain tensor distributions can be measured with resolution below the grain size of most materials. The elastic strain tensor elements can typically be determined with uncertainties less than 100 ppm in brittle materials. Orientations can be quantified to ∼0.01° and the local unpaired dislocation density can be measured in ductile materials. Efforts are underway to improve the spatial resolution and increase the depth probed. Because the 3D X-ray crystal microscope is a penetrating nondestructive tool, it is ideal for studies of mesoscale structural evolution in materials. The unprecedented information that can be obtained with this new class of instrumentation is certain to advance our understanding of the materials physics underpinning the behavior of polycrystalline materials.
Examining the Nature and Dynamics of At-destination Recommendations: The Local Experts' Perspective

At-destination referrals from local experts play a critical and complementary role in information sourcing and venue decision strategies by visitors of a destination. This context-specific form of ...
Demands of the joint committee's standards for educational evaluation

Abstract The study examines demands placed on evaluators by the the Joint Committee on Educational Evaluation's standards. Twenty-two experts in evaluation rated the compatibility of implementing pairs of standards or rated individual standards on a series of scales. Multidimensional scaling of the compatibility judgments revealed five demands of ethical practice: evaluators must attend to the contextual and political circumstances of the evaluation; they must exhibit professionalism in their work; they must conduct the evaluation openly and consult widely; evaluators must meet canons of social science practice; and finally, evaluators' research activities must attend to the specific evaluation setting. The demand to attend to the contextual and political circumstances of the evaluation presents the greatest potential for conflict with other demands and is in greatest need of development.
Photon contribution to tumor dose from considerations of 131I radiolabeled antibody uptake in liver, spleen, and whole body.

The contribution of penetrating photon energy to tumor dose is usually ignored because of the difficulty in calculating absorbed fractions and because it is frequently assumed to represent a small proportion of the total energy. The MABDOSE software—written explicitly to simulate photon transport for the calculation of penetrating radiation absorbed fractions—was used to simulate the 131I photon spectrum originating from the liver, spleen, and whole body source organs. Specific absorbed fractions were calculated for tumors of radius 1.0, 1.5, and 2.0 cm placed near the liver and spleen in the Reference Man geometry. Cumulated activities were estimated using values reported from the literature. Dosimetry estimates from the combined cumulated activity and specific absorbed fractions indicate that neglecting the photon contribution underestimates the tumor dose by 10%–25%.
0117 Nonmalignant Disease Mortality among Styrene, Fibreglass, and Wood Dust Exposed Workers in the Reinforced Plastic Boatbuilding Industry

Objectives To further evaluate the association of styrene, fibreglass, and wood dust exposure with non-malignant diseases, we extended follow-up through 2008 for 5203 workers exposed to styrene, fibreglass, and wood dust between 1959 and 1978 at two boat building plants. Method We used a person-years analysis program, LTAS.NET to compute standardised mortality ratios (SMRs) using Washington State and U.S. rates, standardised rate ratios (SRRs), and 95% confidence intervals. SMRs were stratified by exposure category (low or high) and duration of employment category (≤ 1 year, 1+ years). Results Overall, 1206 nonmalignant deaths occurred (WA SMR 1.14, CI 1.08–1.21), with excess mortality for chronic obstructive pulmonary disease (COPD) overall (n = 112, WA SMR 1.61, CI 1.32–1.93), and among 2063 workers highly exposed to styrene and fibreglass (n = 39, WA SMR 2.37, CI 1.69–3.25). Results were similar using U.S. mortality rates. Workers employed for less than one year had statistically significant increased mortality from several lifestyle-related outcomes (alcoholism, ischaemic heart disease, cirrhosis, accidental poisoning and homicide). Conclusions The excess COPD mortality in this cohort is difficult to interpret. Recent reports associate styrene/fibreglass reinforced plastic manufacturing with another respiratory disease - bronchiolitis obliterans. Based on a review of COPD death certificates, bronchiolitis obliterans does not appear to be a contributing factor for excess COPD mortality. The COPD excess in this study points to a need for an in-depth investigation of respiratory disease and occupational styrene exposure. Short term worker results are consistent with other occupational cohort studies.
Effects of testosterone and erythropoietin on erythroid colony formation in rabbit bone marrow cultures

Summary Testosterone was found to produce a significant increase (43%–94%) in erythroid colony formation at concentrations of 10 −4 –10 −7 M in rabbit bone marrow cultures using a methyl cellulose gel system. The increase in numbers of erythroid colonies in cultures stimulated by erythropoietin (ESF) was significantly greater than that of controls. An additive effect on erythroid colonies was seen with a combination of testosterone and ESF. The increase in the number of erythroid colonies in cultures stimulated by testosterone was completely blocked by the addition of busulfan to the culture medium. Busulfan has been postulated to inhibit the formation of erythropoietin responsive cells (ERC) from hematopoietic stem cells (CFC). Thus, these findings suggest that testosterone may act directly on CFC to enhance their differentiation into the ERC compartment causing an increase in nucleated erythroid cells. Busulfan did not suppress the increase in the numbers of erythroid colonies in cultures stimulated by ESF, thus indicating that the mechanisms of action of testosterone and ESF on erythroid cell kinetics in vitro are different.
Modeling and predicting non-isothermal microbial growth using general purpose software

Published experimental isothermal growth curves of Clostridium perfringens cells in ground ham were fitted with a modified three-parameter version of the logistic equation as a primary model and the temperature dependence of the three parameters by ad hoc empirical secondary models. These were used to predict the organism's non-isothermal growth curves under three different cooling regimes. The assumption has been that the organism's instantaneous (or momentary) non-isothermal growth rate is the isothermal rate at the given temperature at a time that corresponds to its instantaneous population size. This could be translated into a differential rate model equation, whose coefficients are constructed from terms that reflect the changing growth parameters with temperature and hence with time. The continuous rate equation, however, can be solved incrementally by a numerical procedure that can be implemented in similar purpose software like Microsoft Excel®. In all three cases, there was good agreement between the growth curves predicted by the model and those found experimentally. This demonstrated that the procedure can be used to generate growth curves under complicated thermal histories that may include regular and irregular temperature oscillations.
A Framework of Survivability Requirement Specification for Critical Information Systems

Survivability represents a system's ability to provide essential services in the presence of attacks and failures, and to recover full services in a timely manner when the environment improves. For many critical systems used in national defense, healthcare, and utility infrastructure, survivability is a key requirement. Currently, there is a lack of research on systematic reasoning and specification of the requirements for system survivability from a user's perspective. In this paper, we present methods that enable users to specify measureable and certifiable survivability requirements and represent their survivability policy. A survivability decision model is proposed which complies with both survivability practical evidence and theoretical models. From the perspective of system acquisition and engineering, survivability requirement is the important first step in survivability specification, compliance formulation, and proof verification. A military Command and Control (C-2) system is used throughout the paper as an illustrative example for user's survivability requirement specification and representation.
All-optical SOA latch fail-safe alarm system

Emergency alarm systems, for example, that switch off critical processes in process plant, are vulnerable to deliberate or accidental sabotage through coupling of electromagnetic pulses (EMP) to wires and/or from sparks due to broken wires. A proposed system significantly reduces vulnerability by using a fast all-optical latch in conjunction with an optical sensor and optical fibers. Sparks cannot be created on breaking an optical beam and electromagnetic field transients have negligible effect on optical signals. The optical latch uses optical semiconductor amplifiers (SOAs) configured to form a flip-flop. The flip-flop latches after the occurrence of an intrusion that may be as short as a few nanoseconds, much faster than most environmental changes occur. Detection of an emergency or any break in connections causes the light to drop, triggering the alarm. Computer simulation shows that the all-optical latch is fast and effective.
Rational design and simple chemistry yield a superior, neuroprotective HDAC6 inhibitor, tubastatin A.

Structure-based drug design combined with homology modeling techniques were used to develop potent inhibitors of HDAC6 that display superior selectivity for the HDAC6 isozyme compared to other inhibitors. These inhibitors can be assembled in a few synthetic steps, and thus are readily scaled up for in vivo studies. An optimized compound from this series, designated Tubastatin A, was tested in primary cortical neuron cultures in which it was found to induce elevated levels of acetylated α-tubulin, but not histone, consistent with its HDAC6 selectivity. Tubastatin A also conferred dose-dependent protection in primary cortical neuron cultures against glutathione depletion-induced oxidative stress. Importantly, when given alone at all concentrations tested, this hydroxamate-containing HDAC6-selective compound displayed no neuronal toxicity, thus, forecasting the potential application of this agent and its analogues to neurodegenerative conditions.
Donor lymphocyte infusion therapy.

Donor lymphocyte infusion (DLI), which is therapy typically used after stem cell transplant, is a relatively new therapeutic intervention. It has been used in a number of hematopoietic malignancies, for some solid tumor malignancies, for its viral modulation effects, and as a prophylactic approach in the prevention of recurrent disease. The efficacy of this therapy is most evident in patients who have chronic myelogenous leukemia. However, studies of other diseases have been less forth-coming in showing clear benefit. Even in patient groups in which disease remission has been attributed to DLI, the risks of the treatment, namely graft-versus-host disease, may invalidate its use. This article summarizes a number of key studies addressing its usefulness in a number of disease states, risks of therapy, and strategies to ameliorate those risks while preserving benefit. It also examines tools that have been developed to more accurately describe survival benefits attributable to DLI.