cssi/SciSciGPT-SciSciNet huggingface dataset:
Extended Passband Bandstop Filter Cascade With Continuous 0.85–6.6-GHz Coverage

This paper presents a cascade of tunable bandstop filters with a wide spurious-free upper passband, which is completely spanned by the tuning range of the notch responses. A collection of resonators is shown to be able to provide bandstop filter responses over a 7.8 to 1 tuning range. By using spurious-free upper passband aperture-coupled cavity bandstop filters, multiple resonators, each with octave tuning, can cover a multioctave frequency range in a cascade. It is shown that the upper passband of this type of filter is limited by the reactance of the coupling apertures, which produce an unwanted in-band resonance unless designed properly. The details of this design process are explained and used to design a six-resonator bandstop filter cascade that is able to provide a bandstop filter response with up to 55 dB attenuation over the continuous band of 0.85-6.6 GHz. Through dynamic allocation of the cascade circuit's transmission zeros, one-, two-, three-, and four-pole bandstop filter responses of variable bandwidth can be realized over different frequency ranges, offering numerous bandwidth-attenuation level tradeoff combinations.
Measurement, modelling, and simulation of drift space leakage signals in crossed-field amplifiers

Summary form only given, as follows. Previous experimental results have indicated an RF signal leakage through the drift space of Crossed-Field Amplifiers (CFAs). We have collected frequency swept S-parameter data for both CFA on and off conditions and transformed these results to the time domain. Two time signals in addition to the main path signal have been found in S/sub 21/(t) data, which originate from drift space leakage. One of the additional time signals precedes the main path signal and the other is delayed with respect to the main path signal. The preceding time signal is due to a quick passage path from input to output, without ever entering the main path slow-wave circuit. The delayed time signal originates from a signal which travels along the slow-wave circuit, passes through the drift space, and travels along the slow-wave circuit a second time before exiting the CFA as output. We have confirmed the presence of three time signals in CFA off response by conducting real-time digitization experiments. A model has been developed to describe leakage and main path signals, as well as a method of determining model parameters from S-parameter values. The inclusion of RF drift space leakage in the MASK simulation program is achieved by introducing a feedback impedance, with an impedance value determined using measured S-parameter results and MASK slow-wave circuit model parameters. The importance of RF drift space leakage on amplifier performance characteristics such as signal to noise ratio are emphasized.
Lifelength in a random environment

Abstract Let T denote the lifelength of a component, the distribution of which, conditional on a parameter y , is known. It is supposed that y is a realization of nonnegative stochastic process { Y , t ⩾0}, reflecting random variation in the environment in which the component is operating. Conditions are determined under which the distribution of T given { Y ( t ), t ⩾0} is IFR, DFR, IFRA, DFRA, NBU or NWU. Further, conditions are determined under which, if the conditional distributions of T 1 and T 2 , the lifelengths of two components, are ordered stochastically or in variability, a similar order holds for the corresponding marginal distributions.
Inhibition of potassium-stimulated release of [3H]dopamine from rat striata as a result of prior exposure to cocaine, nomifensine, or mazindol.

The nerve terminals in the striata of rat brain were labeled in vitro with [3H]dopamine via the uptake mechanism for catecholamines. Subsequently, the striata were incubated with cocaine, nomifensine, or mazindol, inhibitors of catecholamine uptake. The tissues were rinsed in fresh medium and then stimulated with 20 mM potassium to induce release of [3H]dopamine. Under these conditions, each drug decreased the potassium-stimulated release of radioactivity by 40–50% compared to control tissues which had not been exposed to the drugs.
Vive la Difference

The subfields of the primate visual cortex differ in their cytological composition, including the relative width of the layers. In this issue of Neuron, Lukaszewicz et al. report that the origin of these laminar, and thus areal, differences can be traced to the kinetics of progenitor cell divisions in the subjacent proliferative zones that generate neurons that migrate radially to the appropriate layers at each side of the cytoarchitectonic border.
Cooling water chlorination and productivity of entrained phytoplankton

A study to determine the effects of various concentrations of chlorine on the productivity of entrained marine phytoplankton was carried out at a nuclear power station on northeastern Long Island Sound, USA. Chlorine is a biocide used to control the growth of marine fouling organisms on the walls of many power station cooling systems. Chlorine concentrations considerably below those required to eliminate fouling organisms produced large decreases in the productivity of entrained phytoplankton. Generally, between 0.25 and 0.75 ppm residual chlorine at the cooling water discharge, continuously applied, is required to eliminate fouling organisms. At the highest chlorine concentration tested, 0.4 ppm residual at discharge (addition of chlorine at 1.2 ppm at cooling water intake), there was an 83% decrease in productivity as compared with the productivity at the intake. Productivity measurements were made at 6 other continuously applied chlorine concentrations. At the lowest concentration tested, too low to measure with our analytical method (addition of chlorine at 0.1 ppm at the intake), we measured a production decrease of 79%. Thus, a decrease in chlorination dosage of over an order of magnitude produced essentially no reduction in the damage done to entrained phytoplankton. Application of chlorine intermittently produced somewhat less of a decrease in primary productivity. When there was no chlorine addition during the period of study, there was essentially no effect on productivity. These data indicate that chlorine cannot be used effectively as a biocide for fouling organisms without having adverse effects on entrained phytoplankton.
A PCR test for avian malaria in Hawaiian birds

The decline of native Hawaiian forest birds since European contact is attributed to factors ranging from habitat destruction to interactions with introduced species. Remaining populations of Hawaiian honeycreepers (Fringillidae: Drepanidinae) are most abundant and diverse in high elevation refuges above the normal range of disease-carrying mosquitoes. Challenge experiments suggest that honeycreepers are highly susceptible to avian malaria (Plasmodium sp.) but resistance exists in some species. In order to detect low levels of malarial infection and quantify prevalence of Plasmodium in high elevation natural populations of Hawaiian birds, a polymerase chain reaction (PCR) based diagnostic test was developed that identifies rRNA genes of Plasmodium in avian blood samples. Quantitative competitive PCR (QC-PCR) experiments indicate that the detection limit of our test is an order of magnitude greater than that reported for human malaria DNA blot tests. Compared with standard histological methods, the PCR test detected a higher prevalence of diseased birds at mid-elevations. Malaria was detected in three species of native birds living in a high elevation wildlife refuge on the island of Hawaii and in four species from Maui. Our results show that avian malaria is more widespread in Hawaiian forests than previously thought, a finding that has important conservation implications for these threatened species.
Optimal decentralized primary frequency control in power networks

We augment existing generator-side primary frequency control with load-side control that are local, ubiquitous, and continuous. The mechanisms on both the generator and the load sides are decentralized in that their control decisions are functions of locally measurable frequency deviations. These local algorithms interact over the network through nonlinear power flows. We design the local frequency feedback control so that any equilibrium point of the closed-loop system is the solution to an optimization problem that minimizes the total generation cost and user disutility subject to power balance across entire network. With Lyapunov method we derive a sufficient condition for any equilibrium point of the closed-loop system to be asymptotically stable. A simulation demonstrates improvement in both the transient and steady-state performance over the traditional control only on generators, even when the total control capacity remains the same.
Ozone-isoprene reaction: Re-examination of the formation of secondary organic aerosol

[1] The reaction of ozone and isoprene has been studied to examine physical and chemical characteristics of the secondary organic aerosol formed. Using a scanning mobility particle sizer, the volume distribution of the aerosol was found in the range 0.05–0.2 μm. The aerosol yield was estimated to be 0.01, a value which is a factor of 5–10 higher than previous reports. The aerosol formation is complicated by the presence of minor impurities in the isoprene and the fact that OH-radicals produced in the ozonolysis can react with isoprene to produce organic aerosol. Without an OH-radical scavenger present, up to 50% of the observed aerosol comes from the OH channel. A GC-MS analysis of the products of the composite aerosol showed that two methyl tetrols and 2-methylglyceric acid are formed which can be attributed to the OH reaction channel. A measurement of the effective enthalpy of vaporization using a volatility differential mobility analyzer found the aerosol to have ΔHeff of −42 kJ mol−1, a value at the upper end of the range of organic aerosols previously studied. Even with the increased yield found in this study, the ozonolysis reaction probably remains a minor contributor to secondary organic aerosol in PM2.5 from the atmospheric oxidation of isoprene.
Phacotrabeculectomy: assessment of outcomes and surgical improvements.

Purpose To evaluate the outcomes and progress after phacotrabeculectomy at the same clinical setting and/or performed by the same surgeon over the past decade. Setting Eye Institute of Utah, Salt Lake City, Utah, USA. Methods This retrospective study included 60 eyes of 43 patients who had phacotrabeculectomy at a single institute between 1999 and 2005. A modified phacotrabeculectomy surgical technique was used that included a 2-site incision approach, fornix-based flap, use of mitomycin-C, acrylic intraocular lens implantation, sutured scleral and conjunctival flaps, and sutured temporal clear corneal incision. Results Over a mean 30-month follow-up, 57 of the 60 eyes (95%) achieved intraocular pressure (IOP) control (≤21 mm Hg) with or without medication. Thirty eyes (50%) had an IOP of 15 mm Hg or lower, and 34 (57%) had an IOP reduction of at least 30%. The IOP decreased from a preoperative mean of 23.1 mm Hg on a mean number of 1.67 glaucoma medications to a mean of 14.9 mm Hg on a mean of 0.23 medication at the final follow-up ( P Conclusions The surgical technique used in this study appears to be effective and superior to a previous technique at restoring visual acuity, lowering IOP, and reducing the postoperative complication rate. The observations are relevant in the context of improvements of technique over the past decade.
Retinoids antagonize the induction of ornithine decarboxylase activity by phorbol esters and phospholipase C in rat tracheal epithelial cells

In this study we examined the action of phorbol esters, several phospholipases and retinoids on the induction of ornithine decarboxylase (ODC) activity in rat tracheal epithelial cells. 12-O-Tetradecanoylphorbol-13-acetate (TPA) induces ODC activity in these cells in a dose-and time-dependent manner. This induction is inhibited by cycloheximide indicating a requirement for protein synthesis. Tracheal epithelial 2C5 cells contain two binding sites for phorbol esters, one with a high affinity KD,1 = 4.58 nM and one with a low affinity KD,2 = 344.8 nM. The ability of several phorbol esters to induce ODC correlates well with the described efficacy with which they bind to the receptor and is in agreement with the concept that phorbol ester receptors are involved in the induction of ODC. There is strong evidence that the phorbol ester receptor is the protein kinase C for which diacylglycerol is the physiological ligand. Treatment of cells with phospholipase C generates diacylglycerol and induces ODC activity in a dose- and time-dependent manner. Treatment with phospholipase A2 or D has no effect on ODC activity. These results support the concept that activation of protein kinase C is related to the induction of ODC activity. The induction of ODC by TPA as well as by phospholipase C is inhibited by retinoids. Specific cytosolic binding proteins for retinoids might be involved in at least some of the responses to these compounds. To examine whether the binding proteins are involved in the inhibition of ODC we determined the presence of these binding proteins and the structure-activity relationship of retinoids. Both retinol and retinoic acid-binding proteins can be detected in 2C5 cells, their levels are 1.06 and 3.36 pmoles/mg protein, respectively. The ability of several retinoids to inhibit ODC induction correlates well with their binding activity and support a role for these binding proteins in the action of retinoids on ODC induction.
Effects of nutrients and surfactants on pyrene mineralization and Mycobacterium spp. populations in contaminated soil

Abstract The impact of nutrient (KNO 3 and KH 2 PO 4 ) or surfactant (Triton X-100 and Tergitol NP-10) amendments on the mineralization of 14 C-pyrene and the indigenous Mycobacterium spp. community structure in a petroleum-contaminated soil were determined. All soil amendments enhanced pyrene mineralization with nutrients being slightly more effective than surfactants. 16S rRNA genes were PCR-amplified using Mycobacterium spp.-specific primers, separated by temperature gradient gel electrophoresis (TGGE), and prominent bands sequenced to compare the mycobacteria communities. The soil sample with the highest level of mineralization had no detectable changes in the community structure. Disappearance of a specific phylotype occurred in soils with lower mineralization rates. Phylogenetic analysis of sequenced TGGE bands indicated existence of novel strains.
Psoriasis First Presenting Around an Enteral Feeding Tube in Three Pediatric Patients: An Important Consideration for Timely Diagnosis and Management

Pediatric dermatologists may care for patients with percutaneous enteral feeding tubes. Although ostomy complications such as allergic contact and irritant dermatitis are common, psoriasis may be misdiagnosed. We report three novel cases of childhood psoriasis first presenting around an enteral feeding tube site. Localized psoriasis is an important clinical consideration in children with ostomy site eruptions to ensure timely diagnosis and effective management.
Ergonomic risk assessment based on a Bayesian-optimised expert system

Improper application of an ergonomic analysis tool increases the likelihood of high-risk jobs not being detected, thus jeopardising worker’s health. Likewise, significant time and cost may be incurred by redesigning jobs improperly identified as high risk. Utah Intelligent Data Driven Ergonomic Assessment System (IDDEAS) is an expert system that aggregates the outputs of multiple analysis tools to create a more predictive ergonomic analysis tool. Rules in the expert system were optimised by processing health outcome data from hundreds of jobs and analysing the resulting relationship between the system’s prediction and the known health outcomes. IDDEAS appears to improve in predictive ability with addition of expert knowledge and to be more accurate at predicting the level of risk than individual ergonomic analysis tools used alone. The study also provides insight into methods of quantifying health outcomes and analysis tool outputs for use in software systems that integrate or compare ergonomic information.
Transient diffusion of boron implanted in SI along random and channeling directions

Abstract We have studied anomalous diffusion of boron implanted into silicon along the [100] channeling direction versus random directions for 5, 10, and 40 keV, 2 × 1014 cm2 boron implantations. Three different annealing conditions, 800 °C for l h, 900 °C for 30 min, and 1000 °C for 10 s, were studied. Anomalous diffusion was observed for all implants annealed at all conditions. The amount of enhanced diffusion is 10–50% higher in the implants along the channeling direction than along the random directions. We attribute the mechanism of the diffusion enhancement to the annealing of ion implantation damage. The difference of diffusion enhancement between channeled implants and random implants are due to the difference in damage profile of the two different implants. Electrical activity of boron is observed for random and for channeled implantations, and the shape of the Hall profile agrees with that of SIMS.
Drinking to Fit in: Examining the Need to Belong as a Moderator of Perceptions of Best Friends’ Alcohol Use and Related Risk Cognitions Among College Students

The primary objective of the present study was to examine whether the need to belong moderates the relation between perceived descriptive norms for best friend alcohol use and alcohol-related cognitions outlined in the Prototype Willingness model (i.e., willingness, attitudes, and prototype favorability) among college students. Three hundred forty-six college students (197 female) completed the survey. Regression results indicated that the effect of perceptions of best friend alcohol use on risk cognitions was stronger among students reporting a greater need to belong. The findings suggest that interventions utilizing descriptive norms may be more efficacious among those higher in a need to belong.
What is the future of lipidology

Daniel J Rader University of Pennsylvania School of Medicine, Institute for Translational Medicine and Therapeutics, Cardiovascular Institute, and Institute for Diabetes, Obesity and Metabolism, 654 BRB II/III, 421 Curie Blvd, Philadelphia, PA 19104, USA Tel.: +1 215 573 4176; Fax: +1 215 573 8606; rader@mail.med.upenn.edu ‘The next 25 years should be more exciting than the last as the field of lipidology matures and contributes, in a major way, to reduction in the risk of cardiovascular disease and potentially other diseases as well.’
The choice of alternative corporate governance systems: ownership structures and performance in Italian unlisted firms in 2008

The 2003 Italian corporate law reform, which established one-tier and two-tier boards for listed and unlisted joint stock companies, introduced alternative corporate governance systems. In addition to the traditional model, which, at least in its basic features, continues to be used by the Italian legislator, the two ‘alternative’ models of corporate governance generated by the 2003 reform differ in terms of their methods of appointment of managing and controlling bodies. Taking into account the surprisingly limited adoption of the new systems introduced by the reform after five years, this work implements regression analyses in order to compare the choice of corporate governance systems in Italian unlisted firms: the corporations with best performances in terms of return on assets have continued to use the traditional system; moreover, firms with a less concentrated ownership structure and the lowest proportion of individual shareholders have adopted a two-tier model. These findings support the preference of a two-tier board system for pyramidal structured companies hold by family groups.
P3-like brain waves in normal monkeys and in monkeys with medial temporal lesions.

The human brain produces a characteristic electrical response to relevant events that occur unexpectedly. Recent reports have suggested that a prominent part of this event-related brain potential—the P3 wave—may be related to memory functions and may arise from activity within the medial temporal lobe, especially the hippocampus. The latter idea was tested by means of epidural recordings of brain waves in monkeys. Responses to deviant auditory stimuli bore a close resemblance to P3 waves recorded from human subjects under comparable conditions. Monkeys with bilateral lesions of the medial temporal lobe still produced P3-like brain waves, which indicates that medial temporal brain structures are not critical for their generation. Perceptual and cognitive events in humans are reliably associated with measures of brain electrical activity recorded noninvasively from the scalp and extracted from the electroencephalogram using signal averaging. These event-related brain potentials (ERPs) provide a way to study neural mechanisms of information processing (Donchin, 1984; Gaillard R Galambos& Hillyard, 1981; Hillyard &Kutas, 1983).
Degradation of Connexins Through the Proteasomal, Endolysosomal and Phagolysosomal Pathways

Connexins comprise gap junction channels, which create a direct conduit between the cytoplasms of adjacent cells and provide for intercellular communication. Therefore, the level of total cellular connexin protein can have a direct influence on the level of intercellular communication. Control of connexin protein levels can occur through different mechanisms during the connexin life cycle, such as by regulation of connexin gene expression and turnover of existing protein. The degradation of connexins has been extensively studied, revealing proteasomal, endolysosomal and more recently autophagosomal degradation mechanisms that modulate connexin turnover and, subsequently, affect intercellular communication. Here, we review the current knowledge of connexin degradation pathways.
Children's identity matching and oddity: assessing control by specific and general sample-comparison relations

After children in Experiments 1 and 2 learned identity matching or oddity, control by sample-comparison relations was assessed. Tests for generalized control displayed novel samples and two comparison stimuli, one identical to the sample. Specific relations were tested with identical or nonidentical sample-comparison stimuli from one set of stimuli and substitute comparisons from either the other training set or from a novel set. When tests displayed identical stimuli, patterns of comparison selection suggested control by generalized identity and oddity. However, selection patterns varied when stimuli were nonidentical and familiar or novel substitute comparisons were used. Therefore, control by specific relations is not a precondition for generalized identity and oddity. One set of training stimuli was used in Experiment 3, and generalized performances occurred again. Moreover, control by specific relations was shown by the oddity subjects and 2 of 6 identity subjects. Generalized and specific control may therefore exist simultaneously. In Experiment 4, selections were irregular on tests displaying substitute comparisons and samples and familiar comparison stimuli; this finding supported the relational account of specific sample-comparison control found in Experiment 3.
A survey of the literature on the optimal peg

Abstract It is widely agreed that floating is not an appropriate exchange rate policy for most developing countries, but in a world of generalized floating the question of exchange rate policy is not resolved by deciding to peg rather than to float: it is also necessary to decide to what to peg. This is the question of the ‘optimal peg’, on which a significant literature has emerged since 1976. The present paper provides a survey of that literature. Section 2 summarizes the principal papers. Section 3 compares the objectives and rules advocated by different authors. Section 4 evaluates the alternative approaches, arguing that in general the peg should be chosen to stabilize the nominal trade-weighted effective exchange rate. Section 5 considers whether this criterion points to the SDR as a satisfactory peg.
Mosaic zebrafish transgenesis for functional genomic analysis of candidate cooperative genes in tumor pathogenesis

Comprehensive genomic analysis has uncovered surprisingly large numbers of genetic alterations in various types of cancers. To robustly and efficiently identify oncogenic "drivers" among these tumors and define their complex relationships with concurrent genetic alterations during tumor pathogenesis remains a daunting task. Recently, zebrafish have emerged as an important animal model for studying human diseases, largely because of their ease of maintenance, high fecundity, obvious advantages for in vivo imaging, high conservation of oncogenes and their molecular pathways, susceptibility to tumorigenesis and, most importantly, the availability of transgenic techniques suitable for use in the fish. Transgenic zebrafish models of cancer have been widely used to dissect oncogenic pathways in diverse tumor types. However, developing a stable transgenic fish model is both tedious and time-consuming, and it is even more difficult and more time-consuming to dissect the cooperation of multiple genes in disease pathogenesis using this approach, which requires the generation of multiple transgenic lines with overexpression of the individual genes of interest followed by complicated breeding of these stable transgenic lines. Hence, use of a mosaic transient transgenic approach in zebrafish offers unique advantages for functional genomic analysis in vivo. Briefly, candidate transgenes can be coinjected into one-cell-stage wild-type or transgenic zebrafish embryos and allowed to integrate together into each somatic cell in a mosaic pattern that leads to mixed genotypes in the same primarily injected animal. This permits one to investigate in a faster and less expensive manner whether and how the candidate genes can collaborate with each other to drive tumorigenesis. By transient overexpression of activated ALK in the transgenic fish overexpressing MYCN, we demonstrate here the cooperation of these two oncogenes in the pathogenesis of a pediatric cancer, neuroblastoma that has resisted most forms of contemporary treatment.
Lymph node metastasis in maxillary sinus carcinoma.

Abstract Purpose: To evaluate the incidence and prognostic significance of lymph node metastasis in maxillary sinus carcinoma. Methods and Materials: We reviewed the records of 97 patients treated for maxillary sinus carcinoma with radiotherapy at Stanford University and at the University of California, San Francisco between 1959 and 1996. Fifty-eight patients had squamous cell carcinoma (SCC), 4 had adenocarcinoma (ADE), 16 had undifferentiated carcinoma (UC), and 19 had adenoid cystic carcinoma (AC). Eight patients had T2, 36 had T3, and 53 had T4 tumors according to the 1997 AJCC staging system. Eleven patients had nodal involvement at diagnosis: 9 with SCC, 1 with UC, and 1 with AC. The most common sites of nodal involvement were ipsilateral level 1 and 2 lymph nodes. Thirty-six patients were treated with definitive radiotherapy alone, and 61 received a combination of surgical and radiation treatment. Thirty-six patients had neck irradiation, 25 of whom received elective neck irradiation (ENI) for N0 necks. The median follow-up for alive patients was 78 months. Results: The median survival for all patients was 22 months (range: 2.4–356 months). The 5- and 10-year actuarial survivals were 34% and 31%, respectively. Ten patients relapsed in the neck, with a 5-year actuarial risk of nodal relapse of 12%. The 5-year risk of neck relapse was 14% for SCC, 25% for ADE, and 7% for both UC and ACC. The overall risk of nodal involvement at either diagnosis or on follow-up was 28% for SCC, 25% for ADE, 12% for UC, and 10% for AC. All patients with nodal involvement had T3–4, and none had T2 tumors. ENI effectively prevented nodal relapse in patients with SCC and N0 neck; the 5-year actuarial risk of nodal relapse was 20% for patients without ENI and 0% for those with elective neck therapy. There was no correlation between neck relapse and primary tumor control or tumor extension into areas containing a rich lymphatic network. The most common sites of nodal relapse were in the ipsilateral level 1–2 nodal regions (11/13). Patients with nodal relapse had a significantly higher risk of distant metastasis on both univariate ( p = 0.02) and multivariate analysis (hazard ratio = 4.5, p = 0.006). The 5-year actuarial risk of distant relapse was 29% for patients with neck control versus 81% for patients with neck failure. There was also a trend for decreased survival with nodal relapse. The 5-year actuarial survival was 37% for patients with neck control and 0% for patients with neck relapse. Conclusion: The overall incidence of lymph node involvement at diagnosis in patients with maxillary sinus carcinoma was 9%. Following treatment, the 5-year risk of nodal relapse was 12%. SCC histology was associated with a high incidence of initial nodal involvement and nodal relapse. None of the patients presenting with SCC histology and N0 necks had nodal relapse after elective neck irradiation. Patients who had nodal relapse had a higher risk of distant metastasis and poorer survival. Therefore, our present policy is to consider elective neck irradiation in patients with T3–4 SCC of the maxillary sinus.
Elementary School Students Mental Computation Proficiencies

Mental computation helps children understand how numbers work, how to make decisions about procedures, and how to create different strategies to solve math problems. Although researchers agree on the importance of mental computation skills, they debate how to help students develop these skills. The present study explored the existing literature in order to identify key points that are related to students’ use of different mental calculation strategies in a variety of settings and their conceptual understanding of those strategies.
Alterations in Size, Number, and Morphology of Gustatory Papillae and Taste Buds in BDNF Null Mutant Mice Demonstrate Neural Dependence of Developing Taste Organs

Sensory ganglia that innervate taste buds and gustatory papillae (geniculate and petrosal) are reduced in volume by about 40% in mice with a targeted deletion of the gene for brain-derived neurotrophic factor (BDNF). In contrast, the trigeminal ganglion, which innervates papillae but not taste buds on the anterior tongue, is reduced by only about 18%. These specific alterations in ganglia that innervate taste organs make possible a test for roles of lingual innervation in the development of appropriate number, morphology, and spatial pattern of fungiform and circumvallate papillae and associated taste buds. We studied tongues of BDNF null mutant and wild-type littermates and made quantitative analyses of all fungiform papillae on the anterior tongue, the single circumvallate papilla on the posterior tongue, and all taste buds in both papilla types. Fungiform papillae and taste buds were reduced in number by about 60% and were substantially smaller in diameter in mutant mice 15‐25 days postnatal. Remaining fungiform papillae were selectively concentrated in the tongue tip region. The circumvallate papilla was reduced in diameter and length by about 40%, and papilla morphology was disrupted. Taste bud number in the circumvallate was reduced by about 70% in mutant tongues, and the remaining taste buds were smaller than those on wild-type tongues. Our results demonstrate a selective dependence of taste organs on a full complement of appropriate innervation for normal growth and morphogenesis. Effects on papillae are not random but are more pronounced in specific lingual regions. Although the geniculate and petrosal ganglia sustain at least half of their normal complement of cell number in BDNF 2/2 mice, remaining ganglion cells do not substitute for lost neurons to rescue taste organs at control numbers. Whereas gustatory ganglia and the taste papillae initially form independently, our results suggest interdependence in later development because ganglia derive BDNF support from target organs and papillae require sensory innervation for morphogenesis. J. Comp. Neurol. 409:13‐24, 1999. r 1999 Wiley-Liss, Inc.
Low complexity decoding of bit-interleaved coded modulation for M-ary QAM

It has been shown by Zehavi that the performance of coded modulation can be improved over a Rayleigh fading channel by bit-wise interleaving at the encoder output, and by using an appropriate soft-decision metric for a Viterbi decoder at the receiver. Caire et al presented the details of the theory behind bit-interleaved coded modulation (BICM). In this paper we show that for Gray encoded M-ary quadrature amplitude modulation (QAM) systems, the bit metrics of BICM can be further simplified. In QAM systems, the maximum likelihood (ML) detector for BICM uses the minimum distance between the received symbol and M/2 constellation points on the complex plane as soft-decision metrics. We show that soft-decision bit metrics for the ML decoder can be further simplified to the minimum distance between the received symbol and /spl radic/M/2 constellation points on the real line /spl Ropf/1. This reduces the number of calculations needed for each bit metric substantially, and therefore reduces the complexity of the decoder without compromising the performance. Simulation results for single carrier modulation (SCM), and multi-carrier modulation (MCM) systems over additive white Gaussian noise (AWGN) and Rayleigh fading channels agree with our findings. In addition, we tie this result to the decoding methods for bit interleaved convolutional code standards used in industry.
Piezoelectric sensors and actuators for active vibration damping using digital control

Light-weight, rapid, multimode control of a vibrating structure is possible by the use of piezoelectric sensors and actuators and feedback control algorithms. The results of vibration control experiments on a prototype structure such as a cantilever beam using PZT sensors and actuators are presented. Different types of position feedback control and steady-state quadratic optimal control were implemented. Particular attention was paid to the control of low-frequency vibration modes. To extend the applicable range of the control algorithms, signals from the partially distributed sensors and actuators were converted to those from the point concept sensors and actuators. >
Neural network performance for binary discrimination tasks. Part II: effect of task, training, and feature preselection

Neural networks are applied to the Rayleigh discrimination task. Network performance is compared to results obtained previously using human viewers, and to the best machine approximation to the ideal observer found in an earlier investigation. We find that simple preprocessing of the input image, in this case by projection, greatly improves network convergence and only results obtained on projections are presented here. It is shown that back propagation neural networks significantly outperform a standard nonadaptive linear machine also operating on the projections. In addition, this back propagation neural network performs competitively to a nonadaptive machine that uses the complete two-dimensional information, even though some relevant information is destroyed in the projection process. Finally, improved performance on this Rayleigh task is found for nonlinear (over linear) neural network decision strategies.
Angiotensin II Stimulates Secretion of Endogenous Ouabain From Bovine Adrenocortical Cells via Angiotensin Type 2 Receptors

Angiotensin II stimulates secretion of corticosteroids and ouabain-like activity from adrenocortical cells. Distinct adrenocortical angiotensin II receptor subtypes (AT1, AT2) have been described, ...
Intra-arterial Blood Pressure Monitoring in the Neonate

Management of the critically ill neonate requires accurate and continuous pressure monitoring of intra-arterial blood pressure. An overview of arterial pressure monitoring is presented, including indications for monitoring, sites, normal values, technique, clinical observations, risks, and problems inherent in this procedure.
The complexity of complex diseases.

Fellow members of our society, I am deeply appreciative for the honor of president you have bestowed upon me. It has been an exciting year, and my responsibilities as president have been greatly helped by the addition of our new executive vice president, Joann Baughman, and also by Executive Director Elaine Strass, Jane Salomon, Marsha Ryan, and the other able members of our administrative office staff.
Idealized walking and running gaits minimize work

Even though human legs allow a wide repertoire of movements, when people travel by foot they mostly use one of two locomotor patterns, namely, walking and running. The selection of these two gaits from the plethora of options might be because walking and running require less metabolic energy than other more unusual gaits. We addressed this possibility previously using numerical optimization of a minimal mathematical model of a biped. We had found that, for a given step-length, the two classical descriptions of walking and running, ‘inverted pendulum walking’ and ‘impulsive running’, do indeed minimize the amount of positive work required at low and high speeds respectively. Here, for the case of small step-lengths, we establish the previous results analytically. First, we simplify the two-dimensional particle trajectory problem to a one-dimensional ‘elevator’ problem. Then we use elementary geometric arguments on the resulting phase plane to show optimality of the two gaits: walking at low speeds and running at high speeds.
High-resolution positional tracking for long-term analysis of Drosophila sleep and locomotion using the "tracker" program.

Drosophila melanogaster has been used for decades in the study of circadian behavior, and more recently has become a popular model for the study of sleep. The classic method for monitoring fly activity involves counting the number of infrared beam crosses in individual small glass tubes. Incident recording methods such as this can measure gross locomotor activity, but they are unable to provide details about where the fly is located in space and do not detect small movements (i.e. anything less than half the enclosure size), which could lead to an overestimation of sleep and an inaccurate report of the behavior of the fly. This is especially problematic if the fly is awake, but is not moving distances that span the enclosure. Similarly, locomotor deficiencies could be incorrectly classified as sleep phenotypes. To address these issues, we have developed a locomotor tracking technique (the “Tracker” program) that records the exact location of a fly in real time. This allows for the detection of very small movements at any location within the tube. In addition to circadian locomotor activity, we are able to collect other information, such as distance, speed, food proximity, place preference, and multiple additional parameters that relate to sleep structure. Direct comparisons of incident recording and our motion tracking application using wild type and locomotor-deficient (CASK-β null) flies show that the increased temporal resolution in the data from the Tracker program can greatly affect the interpretation of the state of the fly. This is especially evident when a particular condition or genotype has strong effects on the behavior, and can provide a wealth of information previously unavailable to the investigator. The interaction of sleep with other behaviors can also be assessed directly in many cases with this method.
Interaction of flesh color genes in watermelon

Watermelon [Citrullus lanatus (Thunb.) Matsum. & Nakai] flesh color is controlled by several genes to produce red, orange, salmon yellow, canary yellow, or white. The objective of these experiments was to study the interaction of three independently reported gene loci, each having two or three alleles: C (canary yellow) versus c (red), y (salmon yellow) versus Y (red) versus y8 (orange), and i (inhibitory to C) versus I (noninhibitory to C). The interaction of C, y, y8, and i is of interest to those developing new cultivars of watermelon and has not been reported previously. Five crosses were used to study gene action: Yellow Baby 3 Tendersweet Orange Flesh, Yellow Doll 3 Tendersweet Orange Flesh, Yellow Baby 3 Golden Honey, Yellow Doll 3 Golden Honey, and Yellow Baby 3 Sweet Princess. Based on performance of PA, PB, F1, F2, BC1A, and BC1B, the parents have the following genotypes: Yellow Baby 5 CCYYII, Yellow Doll 5 CCYYII, Tendersweet Orange Flesh 5 ccy8y8II, Golden Honey 5 ccyyII, and Sweet Princess 5 ccYYii. Segregation of flesh color in the progeny of the five families supported the previous report of a multiple allelic series at the y locus, where Y (red) was dominant to y8 (orange) and y (salmon yellow). In conclusion, epistasis is involved in the genes for major flesh colors in watermelon, with ii inhibitory to CC (canary yellow), resulting in red flesh, and CC (in the absence of ii) epistatic to YY, producing canary flesh.
The ENSO Teleconnection to the Tropical Atlantic Ocean: Contributions of the Remote and Local SSTs to Rainfall Variability in the Tropical Americas*

Recent developments in Tropical Atlantic Variability (TAV) identify the El Nino-Southern Oscillation (ENSO) as one of the leading factors in the interannual climate variability of the basin. An ENSO event results in Tropic- wide anomalies in the atmospheric circulation that have a direct effect on precipitation variability, as well as an indirect effect, that is, one mediated by sea surface temperature (SST) anomalies generated in the remote ocean basins. In order to separate the relative contributions of the atmospheric and oceanic components of the ENSO teleconnection to the tropical Atlantic Ocean, results from two ensembles of atmospheric general cir- culation model (AGCM) experiments, differing in oceanic boundary conditions, are compared. AGCM integra- tions performed with the Community Climate Model version 3 (CCM3), forced by global, observed SST during 1950-94 reproduce the observed ENSO-related rainfall anomalies over the tropical Americas and adjacent Atlantic. A parallel ensemble of integrations, forced with observed SST in the tropical Atlantic only, and climatology elsewhere, is used to separate the effect of the direct atmospheric teleconnection from the atmo- sphere's response to the ENSO-forced SST anomalies in the Atlantic basin. It is found that ENSO-related atmospheric and oceanic anomalies force rainfall anomalies of the same sign in northeast Brazil, of opposite sign in the Caribbean basin. The direct atmospheric influence of a warm ENSO event reduces model rainfall as a whole over the tropical Atlantic basin. This observation is consistent with the hypothesis that an ENSO-related Tropic-wide warming of the free troposphere forces the vertical stabilization of the tropical atmosphere. ENSO-related atmospheric anomalies are also known to force a delayed (relative to the mature phase of ENSO) warming of tropical North Atlantic SST through the weakening of the northeasterly trade winds and consequent reduction of surface fluxes. It is found that this delayed oceanic component forces a northward displacement of the Atlantic intertropical convergence zone, resulting in increased precipitation over the Caribbean and reduced precipitation over northeast Brazil during the boreal spring following the mature phase of ENSO.
Intimate Versus Nonintimate Partner Murder A Comparison of Offender and Situational Characteristics

To explore whether homicide of intimate partners is distinct from homicide of nonintimates, we compared sociodemographic, legal, family, clinical, and situational characteristics of men who murdered an intimate partner (n = 71) to those of men who murdered a nonintimate (n = 363). Bivariate findings suggest that intimate murder offenders are more socially bonded and conforming regarding employment and relationship patterns and use fatal violence to meet emotional rather than instrumental needs compared to nonintimate offenders. Multivariate findings indicate marital status, history of severe mental illness, and motive are important factors that differentiate men who murder intimates from those who murder nonintimates. Homicide prevention efforts must be tailored to account for factors that differentiate these two offender types.
A local maximum intensity projection tracing of vasculature in Knife-Edge Scanning Microscope volume data

A local maximum intensity projection (MIP) approach to the extraction of a 3D vascular network, acquired by the Knife-Edge Scanning Microscope (KESM), is presented. We build a local volume for local MIP processing at each tracing step in order to reduce the dimension of input data from 3D to 2D, which leads to a 65.22% reduction of computation time compared to 3D tracing method. The proposed method makes use of existing 2D tracing methods, extending them into a 3D tracing method. Our experimental results show that our approach can rapidly and accurately extract the medial axis of vascular data acquired by the KESM.
Use of transjugular intrahepatic portosystemic shunt in liver disease

Abstract Persons with cirrhosis have many complications. Two of these complications are refractory ascites and recurrent gastrointestinal hemorrhage. When medical management has proved ineffective in the management of these two complications, a transjugular intrahepatic portosystemic shunt can be a treatment option. This outpatient procedure can reduce ascites, minimize the need for diuretics, and reduce the potential for gastrointestinal hemorrhage. The procedure is associated with the development of hepatic encephalopathy, which requires vigilant nursing observation. Education of the patient and family regarding the potential development of encephalopathy and the need for follow-up by the physician is important. The collaboration of physicians and nurses in the ongoing monitoring and follow-up of these patients can contribute to an improved quality of life and reduced hospitalizations. Nurses play an important role in alerting physicians to changes in patient condition that might indicate a narrowing of the transjugular intrahepatic portosystemic shunt, which requires intervention. (J Vasc Nurs 2000;18:83-7)
Developing Crop Simulation Model to Suit Diverse Users: Example of Hybrid-Maize Software

We used the Hybrid-Maize program to discuss software features that meet the demands from diverse users. The Hybrid-Maize software features intuitive and flexible input options, comprehensive tabular and graphic simulation outputs. The software comes with complete documentation of model formulation and validation. Moreover, all key internal model parameters are transparent and modifiable. Utility programs are provided as part of the software package to streamline capture of online weather data and subsequent conversion and reformatting, as well as checkup for suspicious or missing data entries. The software has a context-sensitive help system and a comprehensive user's manual with examples of applications. A dedicated web site (www.hybridmaize.unl.edu) was also developed for the software.