cssi/SciSciGPT-SciSciNet huggingface dataset:
Iron levels found in hemochromatosis patients inhibit γ-thrombin-induced platelet aggregation

Hemochromatosis is a common genetic disorder of iron metabolism. The increase in systemic iron associated with hemochromatosis can negatively affect every system in the body, with potentially fatal implications. Little is known about the effects of iron overload on hemostasis and platelet activation.While performing platelet aggregation studies on hemochromatotic blood samples, it was discovered that the increased serum iron levels associated with this disease almost completely inhibited γ-thrombin-induced platelet aggregation. Further studies were conducted with samples derived from control and hemochromatotic individuals to determine the effects of iron on both α- and γ-thrombin-induced platelet aggregations.It was found that γ-thrombin-induced platelet aggregations were strongly inhibited by the direct binding of iron to these enzymes. α-Thrombin activates platelets at multiple receptor sites including the protease-activated receptor-1 (PAR-1), and at high concentrations, at protease-activated receptor...
Pediatric plexiform neurofibromas: impact on morbidity and mortality in neurofibromatosis type 1.

Objective To characterize morbidity, mortality, and surgical outcomes in pediatric patients with symptomatic plexiform neurofibromas (PNFs). Study design We conducted retrospective analysis of data from clinical records of surgical history and other neurofibromatosis type 1 (NF1)-related complications in children with PNFs seen at Cincinnati Children's Hospital Medical Center between 1997 and 2007. Results A total of 154 children with NF1 and PNFs were identified. Children with symptomatic PNFs had increased incidence of other NF1-related tumors ( P P = .024). The most common morbidities leading to surgeries were neurologic, disfigurement, orthopedic, and airway complaints. Less extensive resection predicted a shorter interval to second surgery ( P P Conclusions These findings quantify the increased risk for additional tumors and mortality associated with symptomatic PNFs. Surgical interventions were required in many cases and resulted in added morbidity in some cases. Patients with PNFs were more likely to benefit from surgery when the indications were airway compression or disfigurement.
Effects of Extracapsular Cataract Extraction on the Lens Zonules

The zonules of 27 postmortem eyes were studied grossly using a histologic staining technique that allowed easy visualization of the zonules. Large disinsertions of the zonules were present in 5 of the 20 eyes that had undergone extracapsular cataract extraction (ECCE).
Magnetic properties of the dense Kondo system CeB6 in high magnetic fields

Abstract This work reports on the phase diagram study of the dense Kondo system CeB 6 by means of magnetization ( M ) and transverse magnetoresistance (MR) measurements in magnetic fields ( B ) to 18 T, in the temperature ( T ) range from 1.8 to 40 K. The zero field resistivity displays Kondo behavior in the paramagnetic P-phase, while two discontinuities at low T were observed at T Q ≈3.5 K and T N ≈2.3 K, the boundaries of the antiferro-quadrupolar (AFQ), and antiferromagnetic (AF) phases, respectively. The isothermal transverse MR is large and negative at low T , and it shows a distinct feature when the P–AFQ line of the B – T phase diagram is crossed. Similarly, the M vs. B curves at low temperatures show upward discontinuities at the phase boundary. Both the features in MR and M at the P–AFQ line correlate well in T , revealing the gradual increase of the T for the onset of AFQ ordering with B . No evidence for reentrant behavior could be observed in fields to 18 T.
Morphology of auroral zone radiowave absorption in the Alaska sector

Abstract Particle precipitation patterns in the auroral zone are derived from an investigation of radiowave absorption at about 30 Mc/s from a network of riometer stations located in Alaska. Aurorally associated absorption occurs mainly along a circular zone centered at 66°N geomagnetic latitude and having a width of approximately 10°. This circular structure contrasts with the oval structure revealed by visual auroral displays and magnetic activity. These two zones are nearly coincident on the midnight meridian, but the visual auroral zone is located at about 77°N geomagnetic latitude on the day side. Eight years of data show that the absorption decreases by a factor of two from the sunspot maximum to minimum (1958–1964). During this period of declining solar activity, the center of the auroral absorption zone moved from approximately 65°N to 66·5°N geomagnetic latitude.
Short term energy consumption prediction using bio-inspired fuzzy systems

This paper presents a new particle swarm optimization based fuzzy inference approach to implement short term load forecasting (STLF). Fuzzy logic algorithm is widely employed for modeling highly nonlinear systems and for handling uncertainties of current control systems. However, conventional fuzzy logic systems are incapable of handling complex problems with many input variables because of fixed rule sets and fixed membership function (MF) parameters. This work therefore presents a model-based technique to optimize the fuzzy system's membership functions using particle swarm optimization (PSO) algorithm. The PSO scheme is used for identification of fuzzy models from the input-output data. The results obtained demonstrate that the developed model has better prediction capabilities than a conventional fuzzy model for the same system with heuristically defined MFs. This therefore suggests the proposed method is an effective technique for short-term load forecasting.
A Methodology For Making Operational Performance Comparisons Between Manual And Digital Radiology Configurations

Many Radiology Departments are contemplating a move from manual operations to Picture Archiving and Communications System (PACS) based operations. A question remains regarding the true cost-benefit of serious investments in PACS based operations. A methodology has been established by the Research Triangle Institute (RTI) in cooperation with the University of North Carolina (UNC) at Chapel Hill which addresses aspects of the cost-benefit analysis of manual versus digital operations within a Radiology Department. The methodology has evolved as a collection of modeling tools and techniques. Early tools included spreadsheet models of existing activities within the UNC Radiology Department. Second generation tools now include deterministic network flow modeling and discrete event queuing network modeling packages. Complementary queuing models have been developed to separate the modeling of Department workload size and mix from the model of the man/machine system that services the workload. A range of performance measures have been incorporated into the second generation models. Among these measures are workload throughput, man/machine resource utilization, system and subsystem responses times, and resource availability measures.
Lasting effects of FG-7142 on anxiety, aggression and limbic physiology in the cat.

The effect of the anxiogenic β-carboline, FG-7142, on behavior and limbic physiology was investigated. A single systemic injection of FG-7142 (10 mg/kg) changed behavior for at least 43 days. Two d...
Effects of PHA on rapidly synthesized RNA of murine splenic lymphocytes.

Abstract The treatment of mouse splenic lymphocytes with PHA resulted in a stimulation of uptake and incorporation of 3H-uridine into rapidly synthesized acid-insoluble RNA. Sucrose gradient centrifugation analyses showed these RNA molecules to be heterodisperse and non-rRNA in nature. When the increase in measured RNA synthesis mediated by PHA∗, was analyzed according to the amount of radioactivity in the acid-soluble pools, there was little, if any, difference in the measured synthetic activity of treated and non-treated cells. This observation was supported by a comparable increase in the specific activity of both nuclear and cytoplasmic RNA of PHA-treated lymphocytes. Increases in 3H-uridine incorporation under these experimental conditions, appeared to be primarily due to an enhanced permeability of the cell to the radioactive precursor after the binding of the PHA. This alteration in permeability was not limited to the plasma membrane since proportional increases in the amounts of radioactivity were also measured in the intranuclear pools. Analysis of 3H-RNA by means of poly(U) Sepharose chromatography showed little change in the amounts of RNA-poly(A) present in the nucleus and the cytoplasm following PHA treatment.
In vivo bronchoalveolar macrophage defense against Rhizopus oryzae and Aspergillus fumigatus

The ability of bronchoalveolar macrophages from normal, diabetic, and cortisone-treated mice to inhibit spore germination and kill fungal spores in vivo was investigated. The data indicated that the normal host controls different fungal infections in the lungs by different mechanisms. Prevention of mucormycosis required inhibition of fungal spore germination by alveolar macrophages. In contrast, pulmonary defense against aspergillosis depended on early killing of conidia by alveolar macrophages and not on inhibition of germination by bronchoalveolar macrophages. Bronchoalveolar macrophages in diabetic and cortisone-treated animals allowed fungal spore germination, thereby permitting infection by Rhizopus oryzae. In the cortisone-treated mouse, bronchoalveolar macrophages did not kill fungal conidia and progressive infection by Aspergillus fumigatus occurred. Fungicidal activity of bronchoalveolar macrophages was measured with a new in vivo killing assay.
Mixed-metal butterfly acetamidediato clusters derived from a highly reactive ruthenium oxo cluster: synthesis and characterization of [(PPh3)2N][MRu3(CO)12(η2-μ3-NC(μ-O)CH3)], (M = Mn or Re)

Abstract Analogy with the isolable oxo cluster [Fe3(CO)9(μ3-O)]2−, which is structurally interesting and synthetically useful, prompted the present attempt to synthesize its ruthenium analog. Although the high reactivity of [Ru3(CO)9(μ3-O)]2− (I) prevented its isolation, the reaction of this species with [M(CO)3(NCCH3)]+, where M = Mn or Re, yields [PPN][MRu3(CO)12(η2-μ3-NC(μ-O)CH3]−. The high nucleophilicity of the oxo ligand in [Ru3(CO)9(μ3-O)]2− (I) appears to be responsible for the conversion of acetonitrile to an acetamidediato ligand and for the instability of I. The crystal structure of [PPN][MnRu3(CO)12(η2-μ3-NC(μ-O)CH3)]] reveals a hinged butterfly array of metal atoms in which the acetamidediato ligand bridges the two wings with μ3-N bonding to an Mn and two Ru atoms, and μ-O bonding to an Ru atom.
Improving Safety Through Collaboration: The Interdisciplinary Perinatal Practice Committee

Professional Issues Poster Presentation Purpose for the Program Clinical care may not always be consistent with the latest evidence and scientific standards found in the peer‐reviewed scientific literature, professional organization standards, and regulatory agencies. Risk reduction strategies in perinatal practice include adopting professional organization guidelines, standardizing evaluation and monitoring processes, and communicating identifiable pregnancy risks to members of the healthcare team. Communication issues have been identified as a leading cause of sentinel events. There was not an identifiable process to review the scientific literature, compare current practice to current scientific evidence, and recommend change based on the literature review. Proposed Change We needed an opportunity to collaborate with nursing, medical providers, risk management, and administration to look at our processes and practice throughout the continuum of maternal–newborn care. The concept of the Interdisciplinary Perinatal Practice Committee (IPPC) was identified and applied to our setting. Implementation, Outcomes, and Evaluation Discussions with key leaders in nursing, obstetrics, neonatology, and risk management were held to garner support of the idea. The perinatal advanced nurse clinician attended ob‐gyn staff meetings to further promote the idea and to assist with the identification of healthcare providers who would co‐chair the IPPC with nursing. Informal nursing leaders and change agents were recruited to be part of the committee. Since its inception, the IPPC has met regularly. Topics are chosen based on staff input, policies, and procedures that are in need of being updated, and trends in evidence‐based practice in the perinatal setting. The first topic, which took three meetings to review, was the use of oxytocin. Scientific, evidence‐based articles and professional guidelines pertinent to the topic of discussion were sent to the committee members for review before each meeting. Medical education credits and nursing contact hours were obtained for each meeting. Each meeting has consisted of a lively, collaborative, and respectful discussion. Nursing and medicine came together to look at the standards and evidence, compare current practice, and make changes to policies and procedures. New electronic medical record order sets were created based on the work of the IPPC. Order sets default to an increase of the rate of oxytocin every 30 minutes. Random audits of charts have shown that the healthcare providers are consistently using the new order sets. This indicates the success of the work of the IPPC. Implications for Nursing Practice Regularly scheduled meetings will ensure the continued work of the IPPC. This will serve to enhance patient safety as all disciplines involved are communicating using the same framework, collaborating, and integrating current science into practice.
Liver transplant and recurrent disease

Current prophylactic measures have greatly reduced recurrence rates of hepatitis B after liver transplantation. HBIG remains a critically important compound and although there is variability in dosing regimens and target anti-HBs levels, it is the backbone of recurrence prevention. Adjuvant therapies with nucleoside/nucleotide analogs alone have been limited by drug-resistant strains of HBV, but the armamentarium of these molecules continues to grow and hence the management of the post-LT HBV patient will evolve further. Currently lamivudine with HBIG remains an excellent option provided the patient has not developed resistance, especially in the pre-LT period. Adefovir is the drug of choice in that setting and perhaps the preferred drug in the pre-LT setting to allow the use of lamivudine post-LT. Further testing with tenofovir and newer compounds in development will expand these options. The use of multiple nucleoside analogs is an intriguing option, based on the HIV experience of reducing drug resistance and optimizing viral suppression, and will likely be further studied.
A critical analysis of recent innovations in the treatment of intraabdominal infection

Toward the end of the last decade, clinical trial results in the surgical literature reported a major improvement in survival from serious intra-abdominal infection. Mortality rates for certain complex infections, such as necrotizing pancreatitis and postoperative abscess, decreased by almost 50 percent when compared with both hospital controls and the predicted mortality rate according to severity of illness (1-3). This remarkable improvement in outcome can be attributed to innovations in perioperative methods, image-guided therapy for management of postoperative abscesses and other complications and more effective antimicrobial therapy. Advances in each area, along with supporting data and the limitations of therapy, will be reviewed critically. Methods that have been proved by clinical trial will be emphasized.
Clinical cues for detecting ictal asystole

The occurrence of asystole during an epileptic seizure is the most dramatic manifestation of ictal bradycardia. Recognition of ictal asystole is important as treatment with both antiepileptic drugs and cardiac pacing may be necessary. The purpose of this study was to identify clinical cues to aid in the detection of ictal asystole. We analyzed the clinical and electrophysiologic features of all recorded seizures in consecutive patients diagnosed with ictal bradycardia and asystole on prolonged video-EEG/ECG monitoring over a 14 year period. Twenty-nine seizures with ictal bradycardia were identified in 13 patients. Of these, 11 seizures in seven patients were associated with asystole. Bilateral transient limb movements consisting of asymmetric posturing or jerking occurred during eight episodes of ictal asystole, and loss of muscle tone occurred during four. In contrast, neither bilateral limb movement nor loss of muscle tone was observed in any of the non-asystolic seizures, whether ictal bradycardia was present or not. All patients with ictal asystole reported a history of seizure-related falls and brief body and limb jerking. The presence of loss of muscle tone or bilateral asymmetric jerky limb movements during a seizure suggests the possibility of ictal asystole. Video-EEG/ECG monitoring should be considered in patients with epilepsy demonstrating these clinical features to determine if ictal asystole is present.
First-principles study of the mobility of SrTiO 3

We investigate the electronic and vibrational spectra of ${\mathrm{SrTiO}}_{3}$, as well as the coupling between them, using first-principles calculations. We compute electron-phonon scattering rates for the three lowest-energy conduction bands and use Boltzmann transport theory to calculate the room-temperature mobility of ${\mathrm{SrTiO}}_{3}$. The results agree with experiment and highlight the strong impact of longitudinal optical phonon scattering. Our analysis provides important insights into the key factors that determine room-temperature mobility, such as the number of conduction bands and the nature and frequencies of longitudinal phonons. Such insights provide routes to engineering materials with enhanced mobilities.
Adaptive combinatorial design to explore large experimental spaces: approach and validation.

Systems biology requires mathematical tools not only to analyse large genomic datasets, but also to explore large experimental spaces in a systematic yet economical way. We demonstrate that two-factor combinatorial design (CD), shown to be useful in software testing, can be used to design a small set of experiments that would allow biologists to explore larger experimental spaces. Further, the results of an initial set of experiments can be used to seed further ‘Adaptive’ CD experimental designs. As a proof of principle, we demonstrate the usefulness of this Adaptive CD approach by analysing data from the effects of six binary inputs on the regulation of genes in the N-assimilation pathway of Arabidopsis. This CD approach identified the more important regulatory signals previously discovered by traditional experiments using far fewer experiments, and also identified examples of input interactions previously unknown. Tests using simulated data show that Adaptive CD suffers from fewer false positives than traditional experimental designs in determining decisive inputs, and succeeds far more often than traditional or random experimental designs in determining when genes are regulated by input interactions. We conclude that Adaptive CD offers an economical framework for discovering dominant inputs and interactions that affect different aspects of genomic outputs and organismal responses.
Phanotron Rectifiers as a D-C Supply for Elevator Motors

The triple single-phase phanotron rectifiers at the present time are built in capacities up to 40 kw at 230 volts and 75 kw at 550 volts. Their application has not been confined to elevator loads, one having been applied to general machine shop load including cranes, and another handling the entire building load elevators, ventilating fans, pumps, etc. The units are self-contained with all live parts enclosed and if desired the cubicle may be locked. The installation wiring is limited to bringing in the a-c supply and connecting the d-c load. Installation costs are thus held to a minimum. The operation of the seven rectifiers in service has to date been entirely successful. Additional rectifiers have been purchased by the original users after one year of use, indicating the suitability of the rectifier for hoisting service.
Ionic conductivity in superionic Sr F 2

Ionic conductivity measurements have been made as a function of frequency at a variety of temperatures on single crystals of Sr${\mathrm{F}}_{2}$ varying in thickness from a few millimeters to several centimeters, using several different electrode materials. At high temperatures, uncorrected values for the sample resistivity depend strongly on crystal thickness, electrode material, and measuring frequency. However, a more complete complex-impedance analysis discloses that a single value may be determined for the bulk conductivity, dependent only on temperature, and that all other dependences are clearly ascribable to electrode effects. There is, apparently, no intrinsic frequency dependence resulting from bulk properties, as had been earlier conjectured.
It's Only 50 Cents.

Mr. P. appreciated that newspaper more than all of the things that we were doing to preserve his life. The news that he got from the paper was stuff he understood—ERA, batting averages, standings, ...
Herbivore‐Mediated Ecological Costs of Reproduction Shape the Life History of an Iteroparous Plant

Abstract: Plant reproduction yields immediate fitness benefits but can be costly in terms of survival, growth, and future fecundity. Life‐history theory posits that reproductive strategies are shaped by trade‐offs between current and future fitness that result from these direct costs of reproduction. Plant reproduction may also incur indirect ecological costs if it increases susceptibility to herbivores. Yet ecological costs of reproduction have received little empirical attention and remain poorly integrated into life‐history theory. Here, we provide evidence for herbivore‐mediated ecological costs of reproduction, and we develop theory to examine how these costs influence plant life‐history strategies. Field experiments with an iteroparous cactus (Opuntia imbricata) indicated that greater reproductive effort (proportion of meristems allocated to reproduction) led to greater attack by a cactus‐feeding insect (Narnia pallidicornis) and that damage by this herbivore reduced reproductive success. A dynamic ...
Current standards of care for inpatient glycemic management and metabolic control: is it time for definite standards and targets?

Objective: To review the available literature on the presence of diabetes in the inpatient population and its effect on outcomes. Results: Diabetes is a progressively worsening epidemic in the Unit...
Using Silicate and pH Control for Removal of the Rag Layer Containing Clay Solids Formed during Demulsification

Initial processing of Athabasca oil sands obtained from surface mining yields stable water-in-bitumen emulsions. When the bitumen is diluted with naphtha to reduce its viscosity and density, nearly complete separation can be obtained with a suitable coalescer in the absence of clay solids. However, a rag layer forms between the clean oil and free water layers when clay solids are present. We show here that complete separation in this case can be obtained by (a) adding a small amount of sodium silicate during initial emulsion formation to make the solids less oil-wet, (b) removing the clean oil formed following subsequent treatment with a demulsifier and adding sodium hydroxide or sodium silicate with shaking to destroy the rag layer and form a relatively concentrated oil-in-water emulsion nearly free of solids, and (c) adding hydrochloric acid to break the oil-in-water emulsion.
Biological characterization of non-steroidal progestins from botanicals used for women's health.

Progesterone plays a central role in women’s reproductive health. Synthetic progestins, such as medroxyprogesterone acetate (MPA) are often used in hormone replacement therapy (HRT), oral contraceptives, and for the treatment of endometriosis and infertility. Although MPA is clinically effective, it also promiscuously binds to androgen and glucocorticoid receptors (AR/GR) leading to many undesirable side effects including cardiovascular diseases and breast cancers. Therefore, identifying alternative progestins is clinically significant. The purpose of this study was to biologically characterize non-steroidal progestins from botanicals by investigating their interaction and activation of progesterone receptor (PR). Eight botanicals commonly used to alleviate menopausal symptoms were investigated to determine if they contain progestins using a progesterone responsive element (PRE) luciferase reporter assay and a PR polarization competitive binding assay. Red clover extract stimulated PRE-luciferase and bound to PR. A library of purified compounds previously isolated from red clover was screened using the luciferase reporter assay. Kaempferol identified in red clover and a structurally similar flavonoid, apigenin, bound to PR and induced progestegenic activity and P4 regulated genes in breast epithelial cells and human endometrial stromal cells (HESC). Kaempferol and apigenin demonstrated higher progestegenic potency in the HESC compared to breast epithelial cells. Furthermore, phytoprogestins were able to activate P4 signaling in breast epithelial cells without downregulating PR expression. These data suggest that botanical extracts used for women’s health may contain compounds capable of activating progesterone receptor signaling.
Investigation of the reaction of toluene with molecular oxygen in shock-heated gases

Abstract The reaction of toluene with molecular oxygen to yield benzyl and hydroperoxyl radicals has been studied using ultraviolet laser absorption of benzyl radicals at 266 nm in shock-heated gases. Test gas mixtures of toluene with excess oxygen diluted in helium and argon were heated in reflected shock waves to temperatures ranging from 1117 to 1366 K at total pressures around 1.7 bar. The growth in benzyl absorbance was monitored at 266 nm, allowing determination of the rate coefficient for the C6H5CH3 + O2 → C6H5CH2 + HO2, reaction (1). The high signal-to-noise ratio provided by laser absorption provides rate coefficient determinations with an estimated uncertainty of ± 20 % . Fitting both these high-temperature shock tube results and the rate recommendation of Ingham et al. [Proc. Combust. Inst. 25 (1994) 767–774] at 773 K, the rate coefficient for reaction (1) can be described with a three-parameter Arrhenius expression by k 1 ( T ) = 2.18 × 10 7 T 2.5 exp ( − 46 , 045 [ cal / mol ] / R T ) [ cm 3 mol −1 s −1 ] . In addition, the measured benzyl time-histories can be used as experimental targets for the development and validation of detailed mechanisms for toluene oxidation.
Analysis of the impact velocity of powder particles in the cold-gas dynamic-spray process

Abstract While built on a sound physical foundation, isentropic, one-dimensional models generally used to analyze the dynamics of dilute two-phase (feed-powder particles suspended in a carrier gas) flow during the cold-gas dynamic-spray process, require the use of numerical procedures to obtain solutions for the governing equations. Numerical solutions, unfortunately, do not enable an easy establishment of the relationships between the gas, process and feed-powder parameters on one side and the gas and the particle velocities at the nozzle exit and the particle impact velocity, on the other. Analytical solutions for the governing equations in the limits of small and large relative particle/gas velocities and a multiple non-linear regression analysis are used, in the present work, to develop analytical functions which can be used to compute the gas and the particle exit velocities and the particle impact velocity for a given set of the gas, process, and feed-powder parameters. The results obtained using the analytical functions are found to be in a very good agreement with their numerical and experimental counterparts.
Mechanistic characterization of the HDV genomic ribozyme: a mutant of the C41 motif provides insight into the positioning and thermodynamic linkage of metal ions and protons.

Binding of two Mg2+ and two H+ ions influences the self-cleavage activity of the genomic HDV ribozyme. The positioning of these four ligands and their thermodynamic linkage are not fully resolved. Protonated C41 engages in a base triple, whereas protonated C75 has been implicated as an acid−base catalyst in bond cleavage. Prior studies led to the identification of one structural inner-sphere ion and one catalytic outer-sphere ion. In the present study, the contributions of the C41 base triple to the metal ion- and pH-dependence of the reaction are examined. Experiments were conducted on a CG to UA double mutant (DM), which changes the base triple to one involving an unprotonated C41. Below pH 6, the DM has a steeper dependence on pH than the wild-type (WT), consistent with a single protonation misfolding the core; this conclusion is also supported by thermal denaturation studies. Between pH 6 and 8, the WT and DM display nearly identical catalytic metal ion and H+ binding profiles. In contrast, over the s...
webXice: an infrastructure for information commerce on the WWW

Systems for information commerce on the WWW have to support flexible business models if they are to cover the wide range of requirements that are imposed by the different types of information businesses. This leads to non-trivial functional and security requirements both on the provider side and on the consumer side, for which we introduce an architecture and a system implementation called webXice (Web-enabled eXtended Information and Content Exchange protocol). We focus on the question of how participants with minimal technological requisites, i.e. with just standard Web browsers available, can be technologically enabled to participate in the information commerce at a system level, while not sacrificing the functionality and security required by an autonomous participant in an information commerce scenario. In particular, we propose an implementation strategy to efficiently support persistent message logging for lightweight clients, which enables the clients to collect and manage non-reputable messages as proofs. We believe that the capability to support minimal system platforms is a necessary pre-condition for the widespread use of any information commerce infrastructure.
Mutual coupling in phase array

Phase array systems can be found in military radar, satellite communications, space-time adaptive communications, and MIMO systems. As hardware capabilities increase, it will become feasible to implement MIMO communication systems, which will push further towards the Shannon Channel Capacity. This paper presents a comparison of standard beam formations, active impedance and experimental results using microstrip and dipole antenna arrays. It then discusses plausible correction techniques for a mutual coupling corrective network, scan blindness, higher order models, and optimization techniques for finding the coupling coefficients. The operating frequency was chosen to be 2.425 GHz for applications in Wi-Fi system development.
Contrasting processes in silicic magma chambers: evidence from very large volume ignimbrites

Very large volume (> 1000 km 3 of magma) crystal-rich dacitic ignimbrites that lack pronounced evidence of fractional crystallization or vertical zonation erupt in some continental magmatic arcs (e.g. the Lund Tuff of the Great Basin and the Fish Canyon Tuff of Colorado in western USA). Apparently, their magma chambers were only modestly heterogeneous and not systematically zoned from top to bottom. These ignimbrites have 40 to 50 % phenocrysts set in a high-silica rhyolite glass. Mineral assemblages and mineral compositions suggest pre-eruption temperatures were 730 to 820 °C and water and oxygen fugacities were relatively high. We have speculated that these very large volume ignimbrites are unzoned because crystallization and convection in slab-shaped magma chambers inhibited separation of crystals from liquids and resulted in a chamber filled with compositionally heterogeneous magma that lacked systematic chemical zonation or strong fractionation. However, many other very large volume silicic ignimbrites are strongly fractionated and may be vertically zoned (e.g. tuffs related to the Yellowstone hotspot). These rhyolitic tuffs typically have few phenocrysts, anhydrous mineral assemblages, low oxygen fugacities, crystallization temperatures of 830 to 1050 °C, and a strong imprint of fractional crystallization. Yet these Yellowstone-type rhyolites are derived from chambers 40 to 70 km across which have sill-like shapes (depth/diameter ratios much less than 1). Thus, factors other than chamber shape must be important for establishing the degree of evolution and nature of zonation in silicic magma chambers. Here, the role of crystallinity-dependent viscosity on the evolution of these two types of contrasting magmas is explored. Calculated magma viscosities for the hot, dry, crystal-poor rhyolites are significantly lower than for the cooler, wetter, crystal-rich dacites. Perhaps these hot rhyolites had low enough crystal contents and viscosities to allow efficient crystal–liquid separation, probably by a combination of unhindered crystal-settling, floor crystallization (including compaction), and crystallization on the walls of large chambers. Clean separation of melt from residual solids at their sources may have been promoted by their high temperatures and low viscosities ( 4.5 Pa s). In contrast, monotonous dacitic magmas may never have been crystal-free near-liquidus magmas. Their large magma chambers may have developed by progressive growth at a shallow level with repeated input of intermediate to silicic magma. Crystallization of the water-enriched dacitic magmas occurred at lower temperatures ( 10 6.5 Pa s) were significantly higher. These characteristics inhibited all forms of crystal–liquid separation, hindered development of systematic vertical zonation, and promoted quasi-equilibrium crystallization in small domains within large heterogeneous magma chambers. Eruptions of these crystal-rich dacites may only occur if the roof fails over a growing magma chamber that is becoming increasingly molten.
Bleaching of mouse rods: microspectrophotometry and suction-electrode recording.

Key points • When photoreceptors in vertebrate retina are exposed to bright light, a significant proportion of the photopigment in the rods can be bleached. • Bleaching produces a desensitization of the visual system that recovers slowly as pigment is slowly regenerated, by a process known as dark adaptation. • Experiments on isolated amphibian rods have revealed some of the features of bleach-induced desensitization, but such experiments have not so far been possible on mammals. • We now describe an improved method that makes possible the first direct measurements of pigment concentration and rod photoreceptor responses over a wide range of bleaching exposures from isolated cells or pieces of intact mammalian retina. • Our experiments reveal important features of mammalian bleaching adaptation and will now make possible future studies from mouse animal lines containing genetically altered photoreceptor proteins.
Floodplains and Agenda 21: the Upper Nene Valley Project

There is a growing awareness of how floodplain habitats contribute to global biodiversity and of the benefits of undrained floodplain ecosystems, for example: floodwater storage and improvement of water quality. Yet floodplain habitats in Britain are much diminished, with a recent survey showing only 4.2% of lowland river sites, with adjacent floodplain, had extensive wetlands remaining. This Agenda 21 pilot project addresses issues raised by local communities in six parishes along the Upper Nene Valley, in Northamptonshire. These include intensive agriculture, biodiversity conservation, recent serious flooding, gravel extraction and the pressure for housing developments. The project aims to increase the local community's environmental awareness, develop links with farmers and businesses and provide a valuable input to planning policies. Partners include the parish councils and residents within the project area, South Northamptonshire Council and University College Northampton. This paper describes the project vision and initial steps taken to involve local communities in ecological and archaeological surveys. Copyright © 2001 John Wiley & Sons, Ltd and ERP Environment
Estimating the error bound in QOBE Vowel classification

Well documented adaptive properties of quasi-optimal bounding ellipsoid (QOBE) algorithms depend on the choices of error bound. Such dependency becomes particularly noticeable in QOBE linear parameter estimation of speech signals. Vowel classification, for example, would therefore stands to benefit from the efficiency of QOBE algorithms. This paper discusses tradeoffs in error bound estimation and presents related experiments and simulations.
Activation of Intrinsic and Synaptic Currents in Leech Heart Interneurons by Realistic Waveforms

Leech heart interneurons were voltage-clamped with realistic waveforms to investigate the currents underlying the oscillation in the cells. By estimating the leak current parameters in regions in which there was little contamination by voltage-gated currents, it was possible to measure the Ca2+ current, the persistent Na+ current, I P, and the hyperpolarization-activated inward current, I h. The experiments verified a prediction of a computer model of HN cells that the shape of the typical waveform was such that the low-threshold Ca2+ currents were partially inactivated during a slow up-ramp to a plateau potential. A step within the same range of the membrane potential as the realistic waveform produced >4 times as much Ca2+ current. In two-cell voltage-clamp experiments, the step produced 20 times more graded inhibition than the normal presynaptic waveform. When the presynaptic heart interneuron oscillated with spikes, the graded inhibition was larger. The difference may arise from integration of a slowly decaying component of the spike-mediated inhibition. The persistent Na+ current had a very low threshold. During the most hyperpolarized phase of the waveform, I P deactivated to 50% of its maximum conductance. A substantial part of I P, therefore, was effectively contributing to the leak current in the HN cells. The h-current increased for waveforms that had longer periods, whereas increasing the h-current in the model reduced the period. The h-current thus provides negative feedback to perturbations that alter the period of the oscillation.
Nutritionally essential amino acids and metabolic signaling in aging

Aging is associated with a gradual decline in skeletal muscle mass and strength leading to increased risk for functional impairments. Although basal rates of protein synthesis and degradation are largely unaffected with age, the sensitivity of older muscle cells to the anabolic actions of essential amino acids appears to decline. The major pathway through which essential amino acids induce anabolic responses involves the mammalian target of rapamycin (mTOR) Complex 1, a signaling pathway that is especially sensitive to regulation by the branched chain amino acid leucine. Recent evidence suggests that muscle of older individuals require increasing concentrations of leucine to maintain robust anabolic responses through the mTOR pathway. While the exact mechanisms for the age-related alterations in nutritional signaling through the mTOR pathway remain elusive, there is increasing evidence that decreased sensitivity to insulin action, reductions in endothelial function, and increased oxidative stress may be underlying factors in this decrease in anabolic sensitivity. Ensuring adequate nutrition, including sources of high quality protein, and promoting regular physical activity will remain among the frontline defenses against the onset of sarcopenia in older individuals.
Influence of Tomato Seed Addition on the Quality of Wheat Flour Breads

Tomato seed, an abundant tomato processing waste product, contains high amounts of crude fat and protein. The protein is especially high in lysine, the limiting amino acid of cereal products. Dried, ground tomato seeds were added at 5, 10, 15, and 20% wheat flour replacement levels. The influence of tomato seed addition on amino acid content, loaf volume, and staling rate were studied. A sensory evaluation based on odor only was conducted to identify consumer attitudes towards “tomato seed bread.” The addition of tomato seed at a replacement level of 20% to a bread formula with shortening resulted in no significant change (P < 0.05) in staling rate, but showed an increase in specific loaf volume of 20.4%. No significant differences in specific loaf volume were found between bread with 3% shortening and the 10% tomato seed supplemental bread without shortening. Addition of fat extracted tomato seeds at the 20% level decreased specific loaf volume by 72%. The supplementation of wheat flour bread at the 10% and 20% replacement levels increased lysine by 40.2% and 69.0% respectively.
The Rate of Neutron Star Binary Mergers in the Universe: Minimal Predictions for Gravity Wave Detectors

Of the many sources which gravitational wave observatories might see, merging neutron star binaries are the most predictable. Their waveforms at the observable frequencies are easy to calculate. And three systems which will merge in less than a Hubble time have already been observed as binary pulsars: two in the disk of the Galaxy, and one in a globular cluster. From the lifetimes and positions of these, a lower limit to the merger rate in the Galaxy and globular cluster system are inferred with confidence. Taking the merger rate in other galaxies to scale with the star formation rate, the merger rate expected in the local universe is computed. An ultraconservative lower limit to the rate gives three per year within 1 Gpc. The best estimate, still conservative in that it considers only systems like those already observed, gives three per year within 200 Mpc. An upper limit of three mergers per year within 23/h Mpc is set by the rate of Type Ib supernovae. The rates of black hole binary mergers and black hole-neutron star binary mergers are model-dependent, but could be comparable to the given rate of neutron-star binary mergers.
Routine stent implantation vs. percutaneous transluminal angioplasty in femoropopliteal artery disease: a meta-analysis of randomized controlled trials.

We are thankful to Diehm et al. for their interest in our meta-analysis on routine stent implantation vs. percutaneous transluminal angioplasty in femoropopliteal artery disease published in the January issue of the European Heart Journal. 1 Several key issues are raised about the endpoint definitions used in individual studies included in the meta-analysis. We concur about the need for uniform reporting standards for the scientific evaluation of various innovative endovascular treatment approaches and congratulate Diehm et al. 2 on their work to that effect. However, this need neither hampers the deduction of meaningful conclusions nor nullifies the importance of the existing randomized controlled trials published in the current literature. In addition, we recognize that our meta-analysis is susceptible to the major limitations …
Numerical Simulation of Hydrostatic Mountain Waves

Abstract A numerical model is developed for simulating the flow of stably stratified nonrotating air over finite-amplitude, two-dimensional mountain ranges. Special attention is paid to accurate treatment of internal dissipation and to formulation of an upper boundary region and lateral boundary conditions which allow upward and lateral propagation of wave energy out of the model. The model is hydrostatic and uses potential temperature for the vertical coordinate. A local adjustment procedure is derived to parameterize low Richardson number instability. The model behavior is tested against analytic theory and then applied to a variety of idealized and real flow situations, leading to some new insights and new questions on the nature of large-amplitude mountain waves. The model proves to be effective in simulating the structure of two observed cases of strong mountain waves with very different characteristics.
Analysis of Unscheduled Dna Synthesis and S-Phase Synthesis in F344 Rat Kidney After in Vivo Treatment with Mercuric Chloride

A variety of short-term test have been developed to predict the outcome of carcinogenicity bioassays. Unfortunately, the majority of these do not address the issue of tissue-specificity. Tests that focus on tissuespecific responses such as the in vivo — in vitro unscheduled DNA synthesis (UDS) and S-phase synthesis (SPS) assays (Mirsalis, et al., 1985; Mirsalis, 1987) have been reasonably successful in the prediction of hepatocarcinogenic potential. The most widely used system employs hepatocyte cultures derived from animals treated in vivo (Mirsalis and Butterworth, 1980); however, systems for the kidney (Tyson and Mirsalis, 1985; Loury et al., 1987), pancreas (Steinmetz and Mirsalis, 1984), trachea (Doolittle and Butterworth, 1984), stomach (Furihata et al., 1984), and spermatocytes (Working and Butterworth, 1984) have recently been developed.
Functional Neuromuscular Stimulation

If a motor nerve is stimulated from an external electrode the resulting action potential will propagate to the innervated muscle and a twitch will be produced. The muscle responds to the artificially initiated nerve signal just as it would a naturally occurring signal. For patients with (for example) spinal cord injury, signals originating in the brain may be unable to reach the desired motoneuron because of a transected cord. In this case the affected muscle is paralyzed, although it may, otherwise, be healthy and capable of excitation and contraction. In this situation an artificial signal initiated in the nerve will evoke a response. Devising strategies for the stimulation of motoneurons to effect desired muscle contraction is the goal of functional neuromuscular stimulation, and the subject of this chapter.
Formation of Encrustations on Indwelling Urinary Catheters in the Elderly: A Comparison of Different types of Catheter Materials in “Blockers” and “Nonblockers”

In order to determine the effect of catheter materials on formation of encrustations in long-term indwelling urinary catheters in the elderly we performed a crossover study utilizing commercially available silicone, silicone-coated, teflon-coated and latex catheters that were left in place for 14 days. The study was conducted with #18 french catheters fitted with a 30 ml. balloon since smaller size catheters frequently fell out spontaneously. The distinction between patients who were "blockers" and "nonblockers" was found to be clinically useful since "nonblockers", who constituted about half the population, did well regardless of type of catheter material used. Formation of encrustations and blockage was significantly less in "blockers" with silicone than with teflon-coated or latex catheters. The more rapid flow-time through silicone catheters appears to be related to a larger bore. Although this study supports the use of silicone catheters for "blockers" on long-term drainage the results should not be interpreted to imply that they are preferable to other types of catheters for short-term use or to changing less expensive catheters more frequently when needed.
Strategies Toward Sub-0.25 μm Lithography

Bruce Smith discusses various issues relating to sub-0.25 μm lithography, including source wavelength, illumination, masking, and materials.