cssi/SciSciGPT-SciSciNet huggingface dataset:
The Role of Cluster Size and Protein Spatial Pattern in the Immunological Synapse

During antigen recognition by T cells, signaling molecules on the T cell engage ligands on the antigen-presenting cell and organize into spatially distinctive patterns collectively known as the immunological synapse (IS). The spatial arrangement of proteins into well-defined zones within the IS is known to regulate T cell activation and signal transduction. The mechanisms by which this complex organization arises remain unclear. Here we alter the clustering state of the T cell costimulatory molecule, LFA-1, either by direct antibody crosslinking or by crosslinking its ligand, ICAM-1, displayed on the supported bilayer. Changes in receptor clustering lead to progressively more central localization of LFA-1 until it colocalizes with T cell receptors (TCR) at the center. The number of LFA-1 molecules within the resulting clusters is obtained by fluorescence correlation spectroscopy. Our results demonstrate that cluster size is a critical parameter in determining protein spatial positioning in the IS. We discuss a sorting mechanism, based on frictional coupling to the cytoskeleton, which is consistent with these observations and is, in principle, extendable to all cell surface proteins in the synapse. Furthermore, by presenting patterns of immobilized ICAM-1 within a fluid bilayer displaying the TCR ligand, peptide-loaded MHC, we investigate the importance of LFA-1 ring formation to T cell function and signaling.
Effects of prescribed fire and season of burn on direct and indirect levels of tree mortality in Ponderosa and Jeffrey Pine Forests in California, USA.

Abstract Many forests that historically experienced frequent low-intensity wildfires have undergone extensive alterations during the past century. Prescribed fire is now commonly used to restore these fire-adapted forest ecosystems. In this study, we examined the influence of prescribed burn season on levels of tree mortality attributed to prescribed fire effects (direct mortality) and bark beetles (Coleoptera: Curculionidae, Scolytinae) (indirect mortality) in ponderosa pine, Pinus ponderosa Dougl. ex Laws., and Jeffrey pine, Pinus jeffreyi Grev. and Balf., forests in California, USA. A total of 816 trees (9.9% of all trees) died during this 3-yr study. Significantly higher levels of tree mortality (all sources) occurred following early and late season burns compared to the untreated control, but no significant difference was observed between burn treatments. The majority (461 trees) of tree deaths were attributed to direct mortality from prescribed burns and was strongly concentrated (391 trees) in the smallest diameter class ( 50.7 cm dbh), significantly higher levels of tree mortality occurred on early season burns than the untreated control, most of which resulted from indirect mortality attributed to bark beetle attacks, specifically western pine beetle, Dendroctonus brevicomis LeConte, and mountain pine beetle, D . ponderosae Hopkins. Red turpentine beetle, D . valens LeConte, was the most common bark beetle species found colonizing trees, but tree mortality was not attributed to this species. A total of 355 trees (4.3% of all trees) were killed by bark beetles. Dendroctonus brevicomis (67 trees, 18.9%) and D . ponderosae (56 trees, 15.8%), were found colonizing P . ponderosa ; and Jeffrey pine beetle, D . jeffreyi Hopkins, was found colonizing P . jeffreyi (seven trees, 2.0%). We also found pine engraver, Ips pini (Say) (137 trees, 38.6%), and, to a much lesser extent, Orthotomicus (= Ips ) latidens (LeConte) (85 trees, 23.9%) and emarginate ips, I . emarginatus (LeConte) (3 trees, 0.8%) colonizing P . ponderosa and P . jeffreyi . Few meaningful differences in levels of indirect tree mortality attributed to bark beetle attack were observed between early and late season burns. The incidence of root and root collar pathogens ( Leptographium and Sporothrix spp.), including species known to be vectored by bark beetles, was low (18% of trees sampled). The implications of these and other results to management of P . ponderosa and P . jeffreyi forests are discussed in detail.
The induction of neoplasms with a substance released from mouse tumors by tissue culture.

Abstract Evidence suggesting replication of a subcellular tumor-inducing substance in mouse parotid gland neoplasms and mouse leukemias was obtained by culturing preparations from these tumors on monkey kidney and chick chorioallantoic membrane cells in vitro. Unlike the results obtained by Stewart (1953, 1955a, b) with mouse leukemia cell-free extracts, newborn mice injected with cell-free inocula prepared from 20 parotid gland tumors have not developed neoplasms, even after life spans in some instances of more than 2 years. However, when preparations from some of the same tumors were put into tissue cultures and newborn mice were inoculated with the supernatant fluids from these cultures, many developed multiple primary tumors. Mice inoculated with fluids from tissue cultures that had not received the tumor cells failed to develop these neoplasms. All the mice that developed neoplasms had both parotid gland tumors and multiple proliferative renal lesions involving the convoluted tubules. In addition, one or more of the following were observed as primary neoplasms in both sexes: tumors of the submaxillary, sublingual and the exorbital lacrimal glands, thymic epithelioid tumors, tumors of the adrenal medulla, a subcutaneous epithelial tumor in one male, and mammary tumors at an early age in some of the females. Cell-free extracts from a transplanted leukemia and a paraganglioma gave results similar to those obtained with the tissue culture supernatant fluids.
Immunologic aspects and pathology of the malignant lymphomas

Malignant lymphomas have traditionally been classified on solely morphologic grounds. With new immunologic and cytochemical techniques, it has been possible to characterize normal cells of the T-lymphocytic, B-lymphocytic, and monocyte-macrophage systems. Application of these methodologies to malignant lymphomas has established their nature as neoplasmas of the immune system. Within the B-lymphocytic system it is possible to identify subpopulations responsible for Burkitt's tumor, follicular (nodular) lymphomas, lymphocytic lymphomas of intermediate differentiation and well differentiated lymphocytic lymphomas. The T-lymphocytic system includes lymphoblastic lymphomas, mycosis fungoides, and Sezary's syndrome. Large cell lymphomas are diverse but the majority are tumors of transformed lymphocytes, usually of the B-lymphocytic system. The precise nature of the neoplastic cells of Hodgkin's disease, i.e., Reed-Sternberg cells and their mononuclear counterparts, has not yet been established. Despite previous suggestions of a B-lymphocytic or T-lymphocytic origin, recent studies utilizing in vivo cultivation have strongly suggested derivation from the monocyte-macrophage system.
The Button Jejunostomy for Long-Term Jejunal Feeding: Results of a Prospective Randomized Trial

Low profile, self-retaining feeding conduits ("buttons") inserted percutaneously through a mature gastrostomy stoma are ideal for prepyloric feeding. We tested the efficacy of a surgically inserted button (Button, C.R. Bard, Inc) in the jejunum for long-term postpyloric feeding. Forty-two aspiration risk patients were prospectively randomized to receive a standard No. 14 French red rubber catheter (n = 21, mean age 68 +/- 17 years) or the button (n = 21, mean age 68 +/- 18 years). Common indications for jejunal feeding were aphagia due to obtundation (41%) and esophageal dysmotility (41%). All feeding devices were inserted 20 cm distal to the ligament of Treitz via a serosal tunnel (catheter) or double pursestring (button) technique. No patient required reoperation, and cardiopulmonary failure was the most frequent cause of death, occurring in 11 patients (26%). Goal feedings were obtained in 91% of the catheter patients and 100% of the button patients by postoperative day 4.7 +/- 1.9 and 4.2 +/- 2.2, respectively. At a follow-up of 43 +/- 13 days, 12 (92.3%) of 13 catheter patients and 9 (81.8%) of 11 button patients were receiving goal feedings. Three patients in the catheter group and four patients in the button group had resumed an oral diet. Device-related complications (dislodgment, occlusion, peritubular leak, or bowel obstruction) and total number of patients with complications were significantly lower in the button group (one [5%] vs eight [38%] for device-related complications and one [5%] vs six [29%] for incidence of complications for the button and catheter groups, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
Evoked potentials recorded from brain-stem nuclei in awake cat: interaction of tone bursts and continuous tone.

Abstract Previous work indicated that components of the auditory thalamocortical potential evoked by a brief binaural tone burst could be enhanced by certain stimulus combinations, e.g., a brief tone burst in the presence of a continuous tone. The principal questions of the present study were whether enhaced components could be obtained caudal to thalamocortex and whether monaural stimuli would be effective in producing enhancement. Eight cats received electrodes in cochlear nucleus and the nucleus of the inferior colliculus. Custom earmolds were made for each ear of each animal. The median attenuation produced by the earmolds was 35 dB and the use of a single earmold approximated monaural stimulation. Auditory evoked potentials were recorded from the electrodes while the animals were unanesthetized but comfortably restrained. Brief 6.25 kHz tone bursts were presented against a background of silence or of a 4.96 kHz continuous tone. In the presence of the continuous tone, enhanced components were obtained from a majority of the electrodes in inferior colliculus but from none of the electrodes in cochlear nucleus. The late negative component in the colliculus potential was increased in amplitude while other components were reduced in amplitude by the continuous tone. The latencies of all components from all electrodes were increased by the presence of the continuous tone. It was concluded that enhancement effects could be obtained at the level of inferior colliculus, and that binaural stimulation does not appear to be necessary to produce enhanced components.
A grounded theory study of help-seeking behaviors among White male high school students.

This study used grounded theory methodology (B. G. Glaser & A. L. Strauss, 1967; A. Strauss & J. Corbin, 1990) to explore the help-seeking behaviors of a select group of White male adolescents to understand and identify the mental health stressors in their lives and the factors involved with their decisions to seek or not to seek help for those stressors. Semistructured interviews were conducted with 22 males, 4 female adolescent counterparts, 4 male parents, and 5 high school staff members. The substantive grounded theory that emerged was that the communal pressures of wealth, success, and high expectations creates a tremendous amount of stress for males to be successful and fit in and contributes to a gender-linked stigma about males' help-seeking behaviors. Specific motivators and barriers to help seeking are identified and discussed, as are common methods and resources used by males to deal with personal problems. Finally, suggestions for making professional helping services more acceptable to this population are presented, and specific research directions are posited.
Cross-layered resource allocation in UWB noise-OFDM-based ad hoc surveillance networks

Situational awareness in military surveillance and emergency responder scenarios requires detection of long range targets and secure communication of this information across a multi-sensor network. A potential approach towards this requirement is to harness the coexisting advantages of radar sensing and wireless communications. A multi-functional communications-embedded radar design that implicitly develops into a cross-layered multi-radar secure wireless ad hoc network is proposed to address this need. First, we demonstrate radar and communications coexistence through analysis of our novel composite orthogonal frequency division multiplexing (OFDM)-embedded ultra wideband (UWB) noise waveform’s bit error rate and ambiguity function formulations. Second, to solve the medium access problem of allocating the multiple OFDM frequencies between different ad hoc radars nodes, we propose a simple yet fully distributed, channel-diversity-aided algorithm. It constructs a contention-free network, scaling logarithmically with the number of radar nodes, and analytically guarantees a provable fraction of the maximum throughput achieved by any optimal centralized allocation algorithm. Furthermore, our solution dynamically adapts with channel variations and topology changes. Working in-sync with the UWB noise-based single radio multi-channel wireless platform, this distributed resource allocation builds a synergistic cross-layered ad hoc network of radars.
Pregnancy hormones boost beta cells via serotonin

Pregnancy increases the demand for insulin by various tissues in the body, a condition that can lead to gestational diabetes. To shield against this condition, insulin-producing beta cells proliferate in a process now shown to involve the local production of serotonin in response to lactogenic hormones (pages 804–808).
Product systems marketing

Abstract Today more industrial companies are turning to the marketing of systems to satisfy the more extended and complex needs of their customers. Yet there is little knowledge available to guide them in evaluating the merits of adopting the systems marketing approach. This article presents a marketing analysis of the systems strategy and its implications for potential adopters.
Application of ree-eyring generalized flow theory to suspensions of spherical particles

Abstract The generalized flow theory of Ree and Eyring has been applied successfully to the extensive data of Maron and Fok (3) on the flow behavior of X-667 latex in both the Newtonian and non-Newtonian regions. By postulation of the presence of two flow units, a Newtonian water unit and a latex particle flow unit which may be non-Newtonian, an equation involving three parameters was obtained which reproduced very well dependence of the viscosity on rate of shear at all temperatures and concentrations. Further, the theory predicted the correct dependence of the parameters on temperature, from which could be obtained the heats of activation for flow of both the water and latex particles. Both heats of activation were found to be independent of concentration, with that of the water being the same as for the pure liquid. The theory does not predict the concentration dependence of the parameters. However, empirical equations for such dependence were deduced, from which it was possible to ascertain the values of the parameters in the Newtonian range below a volume fraction ν = 0.25, and to calculate therefrom Newtonian relative viscosities in good agreement with the observed ones at all temperatures and concentrations. Further, on extrapolation to ν = 0, ν sp ν t was found to be 2.60 as against the expected Einstein value of 2.50 for suspensions of spheres, while extrapolation to infinite viscosity gave a volume fraction in very good agreement with that expected for the rhombohedral close packing of nonuniform spheres. From the combination of the theoretical and empirical equations were obtained also expressions for the values of the “molecular” parameters of the theory as functions of temperature and concentration, and the entropy of activation for the flow of the latex particles. The distance between equilibrium positions of the water molecules was found to vary from 13 A. to zero between ν = 0 and the volume fraction at which the viscosity becomes infinite. On the other hand, the distances between equilibrium positions and planes of latex particles varied from infinity to zero between the same concentration limits.
Influenza cost and cost-effectiveness studies globally – A review

Every year, approximately 10-20% of the world's population is infected with influenza viruses, resulting in a significant number of outpatient and hospital visits and substantial economic burden both on health care systems and society. With recently updated WHO recommendations on influenza vaccination and broadening vaccine production, policy makers in middle- and low-income countries will need data on the cost of influenza disease and the cost effectiveness of vaccination. We reviewed the published literature to summarize estimates of cost and cost-effectiveness of influenza vaccination. We searched PUBMED (MEDLINE), EMBASE, WEB of KNOWLEDGE, and IGOOGLE using the key words 'influenza', 'economic cost', 'cost effectiveness', and 'economic burden'. We identified 140 studies which estimated either cost associated with seasonal influenza or cost effectiveness/cost-benefit of influenza vaccination. 118 of these studies were conducted in World Bank-defined high income, 22 in upper-middle income, and no studies in low and lower-middle income countries. The per capita cost of a case of influenza illness ranged from $30 to $64. 22 studies reported that influenza vaccination was cost-saving; reported cost-effectiveness ratios were $10,000/outcome in 13 studies, $10,000 to $50,000 in 13 studies, and ≥$50,000 in 3 studies. There were no studies from low income countries and few studies among pregnant women. Substantial differences in methodology limited the generalization of results. Decision makers in lower income countries lack economic data to support influenza vaccine policy decisions, especially of pregnant women. Standardized cost-effectiveness studies of influenza vaccination of WHO-recommended risk groups' methods are urgently needed.
Desmoplastic nevus. A distinct histologic variant of mixed spindle cell and epithelioid cell nevus

From a series of 75 cases of mixed spindle cell and epithelioid cell nevi, 14 were designated as desmoplastic nevi. Junctional activity, theque formation, and pigmentation were uncommon features. As a result, desmoplastic nevi may be confused with a variety of fibrohistiocytic lesions. Well defined intranuclear invaginations of cytoplasm occurred in 12 cases, and were helpful in differentiating desmoplastic nevi from these lesions. Desmoplastic malignant melanoma must also be considered in the microscopic differential diagnosis, but distinguishing features of desmoplastic melanoma include the presence of preexisting lentiginous melanoma, and necrosis of tumor cells and collagen. Desmoplastic nevus was compared to the ordinary variants of mixed spindle cell and eipthelioid cell nevus in an attempt to define etiologic factors responsible for a desmoplastic reaction. No satisfactory explanation could be found since the clinical variables examined were not statistically different.
Application of strain gages to measure adhesive strains through the thickness of an adhesively-bonded stiffened strip

The purpose of the study is to measure the through-the-thickness strain distribution in an adhesively bonded stiffened strip subject to four-point bending and to compare the distribution with predicted results. Small-strain gages are used for measuring the normal strain in the adhesive layer of the strip. A total of 16 120-ohm encapsulated strain gages were mounted on the adhesive layer, and the specimen was loaded quasi-statistically and never to failure. Both the experimental and analytical results show good correlation and, in particular, a high strain gradient acting near the edge of the adhesive layer.
Abstract 2240: Structural variant of osteoprotegerin lacking TRAIL binding for therapeutic bone remodeling in osteolytic malignancies.

Proceedings: AACR 104th Annual Meeting 2013; Apr 6-10, 2013; Washington, DC Current treatments for osteolytic cancer pathology include a combination of radiation and chemotherapy, but toxic side effects are still of major concern. Studies have shown that osteoclast activity is increased in patients with osteolytic cancers such as multiple myeloma, breast and prostate cancer through increased expression of Receptor Activator of Nuclear Factor Kappa B Ligand (RANKL) leading to RANKL/RANK signaling, resulting in osteoclast activation and ultimately bone resorption. Moreover, Osteoprotegerin (OPG), a decoy receptor for RANKL, is disproportionately expressed in these patients who present with bone lesions. Thus, the use of OPG as a therapeutic molecule would greatly decrease osteolytic damage and reduce morbidity. However, despite the potential of OPG in inhibiting the activation of osteoclast, OPG also binds to tumor necrosis factor related apoptosis-inducing ligand (TRAIL) making tumor cells resistant to apoptosis. TRAIL binds to the Death Receptor 4 and 5 (DR4, DR5) and initiate cell death of transformed cells such as MM. The goals of this study was to designed and develop a therapeutic approach to the treatment of osteolytic bone damage by use of genetically altered OPG retaining RANKL binding but abolished in TRAIL binding. Towards uncoupling the events of TRAIL binding of OPG and to improve its utility for bone remodeling without inducing tumor resistance to apoptosis, we created a genetic variant of OPG through structural homology model based on interactive domain identification and by superimposing structural models of TRAIL, OPG and DR5 to identify regions of OPG for rational design. The mutant OPG (mut-OPG) was purified and extensively characterized for its ability for decreasing osteoclast damage without affecting tumor apoptosis pathway both in vivo and in vitro indicating its potential for therapy targeting bone lesions in osteolytic malignancies. Citation Format: Jerome T. Higgs. Structural variant of osteoprotegerin lacking TRAIL binding for therapeutic bone remodeling in osteolytic malignancies. [abstract]. In: Proceedings of the 104th Annual Meeting of the American Association for Cancer Research; 2013 Apr 6-10; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2013;73(8 Suppl):Abstract nr 2240. doi:10.1158/1538-7445.AM2013-2240
A new synthesis of racemic coronamic acid and other cyclopropyl amino acids

Abstract A new method, in which various diazocompounds are added to a dehydro alanine derivative, allows the synthesis of coronamic acid and several other cyclopropyl amino acids.
mRNA of chromosomal proteins HMG-1 and HMG-2 are polyadenylated.

Abstract Total RNA from rat thymus was isolated and fractionated into poly A− and poly A+ RNA. The translation products directed by the poly A− and poly A+ RNA were immunoprecipitated with affinity pure antibodies to chromosomal protein HMG-1. Examination of the immunoprecipitates reveals that the m-RNA for chromosomal proteins HMG-1 and HMG-2 is polyadenylated. Thus, the m-RNA for these chromosomal proteins differ from those for the nucleosomal histones and resemble those coding for the bulk of the cellular proteins.
Sensitivity to Causal Cohesion in Stories by Children with Mild Mental Retardation, Children with Learning Disabilities, and Children without Disabilities

This study investigated whether children with mild disabilities, compared with children without disabilities, are sensitive to the causal structure of stories. Participants were 16 children with mild mental retardation, 29 children with learning disabilities, and 37 children without disabilities who were good readers. The Causal Network Model (Trabasso, Secco, & van den Broek, 1984) was adopted to analyze the participants' causal understanding of stories. Two stories were manipulated to obtain cohesive and noncohesive versions. Cohesion was defined as the proportion of statements included in the causal chain, which is a central path that leads from the beginning to the end of a story. Although children with mild disabilities recalled less than children without disabilities, overall, similar patterns of causal understanding were observed in all groups. All groups recalled cohesive story versions better than noncohesive versions. Statements in the causal chain were better recalled and judged as more importa...
A General Geometric Framework for Control of Electrostatically-Actuated MEMS and NEMS

This paper presents a geometric framework for the modeling and stabilization of a general class of electrostatically-actuated mechanical systems. The class of devices under study consists of a movable, rigid, grounded electrode, with a variety of allowable rotational and/or translational degrees of freedom, and a set of multiple, fixed, independently-addressable, drive electrodes. Previous work has placed the general electrostatic forces and the electrical system in a framework suitable for passivity-based control. This paper generalizes this result further by allowing the electrical part of the model to incorporate current leakage between electrodes. With respect to this model a stabilizing dynamic feedback control laws is derived in terms of coordinate-independent geometric formulas. To obtain controllers for a specific device it is then necessary only to evaluate these formulas. Appropriate approximations may be applied to make the computations more tractable. Performance may be improved using dynamic output feedback, but additional information is needed, typically in the form of a model relating electrode capacitances to the system configuration. We demonstrate the controller computations on a representative MEMS, and validate performance using ANSYS simulations.Copyright © 2005 by ASME
The use of verbal and tactile comfort to alleviate distress in young hospitalized children.

This exploratory study was designed to observe distressed children's responses to verbal and tactile comfort measures. A convenience sample of 63 children between 3 days and 44 months old was drawn from a pediatric unit of a large midwestern hospital. On a random basis, one group of children received verbal, comfort measures for 5 minutes or until they quieted, whichever came first. At the end of 5 minutes, tactile comfort was added if the children were still distressed. The other group received simultaneous tactile-verbal comfort from the beginning. One hundred interventions were carried out on the 63 children. Forty interventions were initially verbal and 60 were tactile-verbal. Among the verbal group, 7 of the interventions were successful in quieting the children as compared to 53 successes of 60 interventions in the tactile-verbal group. This was a highly significant difference. Verbal interventions were more successful for children over 1 year old and tactile comfort was least effective with children in the 13 to 18 month age group. No differences were noted in terms of sex, presence of equipment including restraints, diagnosis, and recency of last feeding.
Time-frequency complexity based remaining useful life (RUL) estimation for bearing faults

Reliable operation of electrical machines depends on the timely detection and diagnosis of faults as well as on prognosis, i.e. estimating the remaining useful life (RUL) of the components. Bearings are the most common components in rotary machines and usually constitute a large portion of the failure cases in these machines. Although there has been a lot of work in the study of bearing life failure mechanisms and modeling, the problem is still far from being solved. In this paper, we introduce a time-frequency feature extraction based method for estimating remaining useful life of bearings from vibration signals. The proposed approach extracts measures that quantify the complexity of time-frequency surfaces corresponding to vibration signals. The extracted features are then tracked through the life time of a bearing using curve fitting and Extended Kalman Filtering algorithms. The proposed methodology is tested on a publicly available bearing data set with known RULs.
Complications of central venous access devices in paediatric haemophilia patients

We conducted a retrospective survey of our experience with central venous access devices (CVADs) implanted in children with haemophilia seen at the Vanderbilt Hemostasis-Thrombosis Clinic from 1986 to 2000. Following discussion with parents on the merits and risks associated with the use of CVADs for immune tolerance induction or factor prophylaxis, catheters were inserted under sterile technique in the operating room. One nurse provided demonstration and teaching about catheter care and access. Thirty central venous catheters were inserted in 22 children. Our survey revealed that the two most common complications associated with central venous catheters were bacteraemia and thrombosis. We found a sepsis rate of 0.30/1000 catheter-days or one episode of bacteraemia for every 3346 days of catheter use. The thrombosis rate of our cohort was 0.13/1000 catheter-days or one episode of thrombosis for every 7529 days of catheter use. Uncomplicated venous access is essential in children with severe haemophilia who require prophylaxis or immune tolerance induction. While infection was the most common complication observed in our series, we experienced a lower overall infection rate than several reported series. Catheter thrombosis and subsequent obstruction may occur as a result of intraluminal fibrin deposits. We conclude that the use of implantable central venous catheters is an effective method for accessing children with haemophilia. We accept that the benefits of CVADs in the treatment of paediatric haemophilia patients outweigh the previously documented risks. Future prospective studies should be designed to define all associated risks and to determine effective strategies to reduce them.
The growth of government

Robert Higgs's Crisis and Leviathan argues that there is a ratchet effect both after major wars and other serious crises, such as depressions: attitudinal or ideological changes lead not only to greater government spending but greater intrusion of government into economic command and control. Higgs's explanation of the growth of government, however, is embedded in and driven by a particular ideological view of the legal‐economic world, one that misapprehends certain legal‐economic fundamentals, including the scope of economic command and control, and that fails to deal with certain interpretive complexities, including alternative explanations.
Comparative studies of collimator performance in DaTscan (Ioflupane I-123) striatal SPECT

Purpose: To determine optimal collimator and gamma camera combination for Ioflupane I-123 (DaTscan) striatal SPECT. Methods: Anthropomorphic basal ganglia phantom was used. The striatal chambers (caudate and putamen chambers) and the large chamber simulating nonspecific background activity in the remainder of the brain were filled with I-123 with the specific activity ratio 7.7. SPECT data were acquired using triple-head gamma camera (THGC) with fan-beam low-energy ultra high-resolution (LEUR) collimators, with dual-head gamma camera (DHGC) with parallel-beam lowenergy high-resolution (LEHR) collimators and medium-energy general-purpose (MEGP) collimators. Data were acquired at 159 keV with a 20% window, with I-123 and Tc-99m flood table for THGC and DHGC, respectively. The images were reconstructed using the OSEM algorithm with resolution modeling and uniform attenuation correction, and Butterworth postfilter, 5th order and 0.64, 0.78 and 1.0 Ny for LEUR, LEHR, and MEGP, respectively. The filter parameters were chosen to optimize the balance between image noise and spatial resolution. Results: The best image quality in terms of spatial resolution and contrast was obtained with fan-beam LEUR/THGC. The MEGP/DHBC produced images with better contrast-to-noise ratio than LEHR/DHGC. The measured ratio of mean activity in striatal chambers to the remainder of the brain was comparable for all three collimator/camera combinations. Conclusions: Based on phantom DaTscan striatal SPECT, the THGC with fan-beam LEUR collimators is preferable. If DHGC is used MEGP collimators provide better image quality, as compared to LEHR. More studies including patient studies are needed to confirm best collimator/camera combination.
Hypomethylation is necessary but not sufficient for V(D)J recombination within a transgenic substrate

Although an inverse correlation between CpG methylation and V(D)J recombination has been demonstrated for both artificial substrates and endogenous genes, it is not known whether all hypomethylated targets are competent to rearrange or if other factors are required. We have created several artificial V(D)J recombination substrate transgenes whose methylation can be controlled by breeding into different genetic backgrounds. A transgene which contains the immunoglobulin heavy chain intronic enhancer rearranges efficiently in B lymphocytes when the transgene loci are unmethylated. When the same loci become methylated, upon breeding into a different mouse strain, no rearrangement can be detected. A similar transgene, but lacking the enhancer, also shows no evidence of V(D)J recombination when it is methylated. Even when this enhancerless transgene is hypomethylated, however, no V(D)J recombination can be detected in B lymphocytes. Thus, hypomethylation is required to permit V(D)J recombination but not all hypomethylated targets are capable of recombination. The results may indicate that the immunoglobulin enhancer is required for the assembly of factors involved in V(D)J recombination.
A biphasic 60-Hz synchronizer circuit for the recording of visually evoked responses in high-noise environments

A simple synchronizer clock circuit is described that aids in the rejection of 60-Hz noise from evoked potential measurements.
The Videogame as Narrative

The commercial begins, predictably, with the studio logo: “Lucas Arts.” Then the scene cuts to a shot of a vast, sunlit cityscape which is soon blocked by the hulk of a moving spaceship. In the dis...
Biogeochemical tracers of the marine cyanobacterium Trichodesmium

We examined the utility of several biogeochemical tracers for following the fate of the planktonic diazotrophic cyanobacterium Trichodesmium in the sea. The presence of a (CIO) fatty acid previously reported was observed in a culture of Trichodesmium but was not found in natural samples. This cyanobacterium had high concentrations of C14 and C16 acids, with lesser amounts of several saturated and unsaturated C18 fatty acids. This composition was similar to that of other marine cyanobacteria. The major hydrocarbon identified was the C17n-alkane, which was present in all samples from the five stations examined. Sterols common to algae and copepods were observed in many samples along with hopanoids representative of bacteria, suggesting a varied community structure in colonies collected from different stations. We found no unique taxonomic marker of Trichodesmium among the sterols. Measurements of the σ15N and σ13C in Trichodesmium samples from the SW Sargasso and NW Caribbean Seas averaged −0.4960 (range from −0.7 to −0.25960) and −12.9%0 (range from −15.2 to −11.9960), respectively, thus confirming previous observations that this cyanobacterial diazotroph has both the lowest σ15N and highest σ13C of any marine phytoplankter observed to date. A culture of Trichodesmium grown under diazotrophic conditions had a σ15N between −1.3 and −3.6960. Our results support the supposition that the relatively low σ15N and high σ13C values observed in suspended and sediment-trapped material from some tropical and subtropical seas result from substantial input of C and N by Trichodesmium.
Chromosome pairing in altered constitutions and models of synapsis and crossing-over.

Metaphase trivalent frequencies from a number of new chromosomal constitutions (various combinations of maize chromosome 2- Tripsacum homeologue primary and secondary interchanges) are presented and compared to previous findings from similar material. It is suggested than an underlying direct relationship may exist between extent of gentic map present in duplicate and triplicate and expectation from a sharing of map probability of crossing-over among all homologues. Theoretical considerations are discussed.
Stewardship And Financial Performance In Wide-Moat Firms

Previous research has shown that the historical appreciation of Morningstar wide-moat companies exceeds that of benchmark indices. In the case of mutual funds, prior work has also demonstrated the significance of Morningstar’s stewardship grade in partially explaining such out performance. The present study examines 181 wide-moat companies and assesses whether stewardship has a comparable influence on the financial performance of individual firms.
Gamma Radiolysis Effects on Grande Ronde Basalt Groundwater

Gamma radiolysis of reference Grande Ronde Basalt groundwater containing 700 mg/L methane produces a milky liquid that is a suspension of fine particles of organic polymers similar to polyethylene. The amount and nature of these polymers does not vary much over the range of conditions tested. Differences in the radiolytic products that are formed may occur when host rock and engineered-barrier materials are present. This possibility is currently being investigated as is the potential for interactions between radionuclides and the products of radiolysis.
A unified framework for advancing array signal processing technology of multichannel microprobe neural recording devices

In this work, we describe a novel framework aimed at enhancing the communication and signal processing technology of microimplanted devices used for recording and stimulating neural cells. The power of the proposed framework stems from providing simple algorithms, yet efficient signal processing power that is suitable for on-chip microprobe design. The framework unifies our previous work on multiresolution analysis and array processing that was aimed at performing typical neural signal processing tasks such as noise suppression, source detection and separation, and information coding. Strategies for optimizing the information transfer have shown to greatly benefit from the optimal array processing mechanisms used and the compression achieved by expressing the data in the multiresolution domain. We demonstrate through simulated and experimental results that the framework provides the basis for simple and practical implementation for today's biosensor array technology requirements without compromising issues of bandwidth, detection and classification.
Elastic Properties of Grain Boundaries in Copper

The elastic constants of a Σ5 (100) twist grain boundary are calculated on a monolayer-by-monolayer basis, and the elastic behavior is shown to differ by up to an order of magnitude from bulk-like behavior. This unusual elastic behavior is found to be similar to that of uniaxiallystrained crystals, since the grain boundaries themselves are regions which are strained (expanded) in one direction.
Enhanced bremsstrahlung from electrons traversing periodic targets

It is shown that for electrons passing through a target with a periodic structure, the resulting bremsstrahlung component polarized parallel to the electron velocity can be enhanced by several orders of magnitude over that from a uniform target of comparable thickness. The enhanced radiation does not have a flat spectrum but exhibits a narrow peak at a frequency that depends on the observation angle, electron velocity, and period of the target structure.
Bayesian analysis for very-low-background counting of short-lived isotopes: Lowest minimum detectable quantity

Conventional statistical analyses of counting measurements with a paired-count blank and sample yield unacceptably-large estimates of uncertainty that reduce measurement sensitivity when applied to very-low-background detection systems. An alternative is presented here: Bayesian analysis using longer-duration background measurements, appropriate modeling of the background, and a binomial distribution of decay-induced counts valid even for short-lived isotopes. We develop the needed formulae and demonstrate how the decision level and sample measurement duration are optimized jointly to produce the lowest minimum detectable quantity subject to constraints of specified acceptable risks of false detection and false failure to detect. A frequentist’s interpretation is maintained by using equal-likelihood prior distributions.
Perturbation analysis of a class of neural networks

We establish robustness stability results for a large class of artificial neural networks for associative memories under parameter perturbations and determine conditions that ensure the existence of asymptotically stable equilibria of the perturbed neural system that are near the asymptotically stable equilibria of the original unperturbed neural network. The proposed stability analysis tool is the sliding mode control and it facilitates the analysis by considering only a reduced-order system instead of the original one and time-dependent external stimuli.
Interleukin-6 Promotes Androgen-independent Growth in LNCaP Human Prostate Cancer Cells

Purpose: Prostate cancer frequently progresses from an initial androgen dependence to androgen independence, rendering the only effective androgen ablation therapy useless. The mechanism underlying the androgen-independent progression is incompletely understood. Interleukin (IL)-6 has been implicated in this androgen-independent progression. In this study, we tested whether IL-6 induces androgen-independent growth both in vitro and in vivo . Experimental Design: IL-6 was expressed in androgen-sensitive LNCaP cells. The effects of IL-6 on androgen receptor activity was determined by Northern blots and gel shift assays. The effects of IL-6 on LNCaP cell growth were determined in vitro by MTT assay and in vivo . Results: IL-6 can enhance the growth of androgen-sensitive LNCaP cells in the androgen-deprived condition in vitro , which is accompanied by elevation of androgen-regulated prostate-specific antigen mRNA expression. IL-6 promotes androgen-sensitive LNCaP cell tumor growth in the castrated male mice. IL-6 enhances androgen receptor DNA binding activity and nuclear translocation. The androgen-independent phenotype induced by IL-6 in LNCaP cells is accompanied by significant activation of signal transducers and activators of transcription 3 and mitogen-activated protein kinase signal pathways. Conclusions: These studies clearly provide experimental evidence that IL-6 initiates and/or enhances the transition of prostate cancer cells from an androgen-dependent to an androgen-independent phenotype.
Organizing Effects of Rapsyn on Neuronal Nicotinic Acetylcholine Receptors

Targeting receptors to appropriate locations on the cell surface is a critical task for neurons. We have examined the possibility that rapsyn controls the distribution of nicotinic receptors on neurons as it does nicotinic receptors on muscle fibers. Cotransfection of QT6 cells with rapsyn and neuronal nicotinic receptor cDNA constructs produced receptor aggregates or clusters that codistributed in part with rapsyn protein. Though all nicotinic receptor subtypes tested were affected by rapsyn, receptors containing the alpha7 gene product were among the most responsive. In addition, rapsyn caused a portion of the nicotinic receptors containing alpha7 subunits to become resistant to solubilization with nonionic detergent and to display a marked increase in metabolic stability. The results are consistent with rapsyn linking the receptors to cytoskeletal elements and suggest that it may play an organizing role determining the fate and location of nicotinic receptors on neurons. Copyright 1998 Academic Press.
Carrots and Sticks: A Comprehensive Business Model for the Successful Achievement of Energy Efficiency Resource Standards

U.S. utilities face significant financial disincentives under traditional regulation in aggressively pursuing cost-effective energy efficiency. Regulators are considering some combination of mandated goals and alternative utility business model components to align the utility’s business and financial interests with state and federal energy efficiency public policy goals. We analyze the financial impacts of an Energy Efficiency Resource Standard on an Arizona electric utility using a pro-forma utility financial model, including impacts on utility earnings, ROE, customer bills and rates. We demonstrate how a viable business model can be designed to improve the business case while retaining sizable benefits for utility customers.
Clocking nanocircuits for nanocomputers and other nanoelectronic systems

Prospective performance bounds are determined by simulation for a class of all-nanoelectronic clocking circuits. Such nano circuits could be utilized as on-chip master clocks for stand-alone nanosystems, as local clocks within nanoelectronic computers, or as local oscillators in mixed-signal nanoelectronic applications. Designs and simulation results are presented for these nano circuits, which are intended to be manufacturable using presently available nanodevices and nanofabrication techniques. The results presented here indicate that such clocking nano circuits, if built using presently available devices, could achieve operating frequencies up to approximately 1 GHz for analog applications and ISO MHz for digital nanoelectronic systems.
Relationships in Medical Subject Headings (MeSH)

Recent efforts to make some of the relationships within MeSH more explicit have led to a deeper understanding of the nature of these relationships. This chapter will explore the relationships represented in MeSH in the light of that understanding. Every term that occurs may be thought of as representing a concept. One or more terms, comprising one or more concepts, grouped together for important reasons, form a descriptor class. The descriptor class is the basic building block of the thesaurus. Relationships among concepts can be represented explicitly in the thesaurus, most notably as relationships within the descriptor class. Hierarchical relationships are at the level of the descriptor class. The hierarchies are key in allowing expanded retrievals. The hierarchical relationships, traditionally thought of as broader or narrower (parent-child) relationships, are better understood as representing broader and narrower retrieval sets. Nevertheless, these hierarchical relationships often reflect important broader-narrower relationships between preferred concepts in descriptor classes. Other types of relationships present in the thesaurus include associative relationships, such as the Pharmacologic Actions or see-related cross references, as well as forbidden combination expressions, such as the Entry Combination.