cssi/SciSciGPT-SciSciNet huggingface dataset:
MicroCantilever (MC) based nanomechanical sensor for detection of molecular interactions

Specific aims of this study are to investigate the mechanism governing surface stress generation associated with chemical or molecular binding on functionalized microcantilevers. Formation of affinity complexes on cantilever surfaces leads to charge redistribution, configurational change and steric hindrance between neighboring molecules resulting in surface stress change and measureable cantilever deformation. A novel interferometry technique employing two adjacent micromachined cantilevers (a sensing/reference pair) was utilized to measure the cantilever deformation. The sensing principle is that binding/reaction of specific chemical or biological species on the sensing cantilever transduces to mechanical deformation. The differential bending of the sensing cantilever respect to the reference cantilever ensures that measured response is insensitive to environmental disturbances. As a proof of principle for the measurement technique, surface stress changes associated with: self-assembly of alkanethiol, hybridization of ssDNA, and the formation of cocaine-aptamer complexes were measured. Dissociation constant (Kd) for each molecular reaction was utilized to estimate the surface coverage of affinity complexes. In the cases of DNA hybridization and cocaine-aptamer binding, measured surface stress was found to be dependent on the surface coverage of the affinity complexes. In order to achieve a better sensitivity for DNA hybridization, immobilization of receptor molecules was modified to enhance themore » deformation of underlying surface. Single-stranded DNA (ssDNA) strands with thiol-modification on both 3-foot and 5-foot ends were immobilized on the gold surface such that both ends are attached to the gold surface. Immobilization condition was controlled to obtain similar receptor density as single-thiolated DNA strands. Hybridization of double-thiolated DNA strands leads to an almost two orders of magnitude increase in cantilever deformation. In both DNA hybridization and the conventional mode for cocaine detection, the lowest detectable concentration was determined by binding activity between the ligand and receptor molecules. In order to overcome this limitation for cocaine detection, a novel competition sensing mode that relies on rate of aptamers unbinding from the cantilever due to either diffusion or reaction with cocaine as target ligands in solution was investigated. The rate of unbinding is found to be dependent on the concentration of cocaine molecules. A model based on diffusion-reaction equation was developed to explain the experimental observation. Experimental results indicate that the competition mode reduces the lowest detectable threshold to 200 nM which is comparable to that achieved analytical techniques such as mass spectrometry.« less
Numerical Irreducible Decomposition Using PHCpack

Homotopy continuation methods have proven to be reliable and efficient to approximate all isolated solutions of polynomial systems. In this paper we show how we can use this capability as a blackbox device to solve systems which have positive dimensional components of solutions. We indicate how the software package PHCpack can be used in conjunction with Maple and programs written in C. We describe a numerically stable algorithm for decomposing positive dimensional solution sets of polynomial systems into irreducible components.
Teaching Social Workers about Trauma: Reducing the Risks of Vicarious Traumatization in the Classroom

There is a growing need to prepare social work students to work with trauma survivors. The framework of vicarious traumatization is used to argue that social work students may be adversely affected by their exposure to trauma cases through reading assignments and classroom discussion. Several guidelines to reduce and alleviate this risk are suggested.
Growth Curve Modeling and Longitudinal Factor Analysis

In psychological science, developmentalists are often interested in examining and understanding change processes. In this chapter we review a variety of longitudinal models and consider how they can be applied to examine intraindividual change and interindividual differences in change. First, a taxonomy describing three types of change processes (incremental change processes, transformational change processes, and stability-maintenance processes) is presented and how a selection of contemporary longitudinal models can be tethered to that taxonomy is considered. A selection of growth models–with emphasis on models that are used to describe nonlinear trajectories–is reviewed and a shift toward the use of differential equations is suggested. A selection of time-series models is shown, with emphasis on models that may facilitate analysis of the big data streams that will become available in few years. Although the distinctions among types of change processes and among analytical frameworks are necessarily fuzzy, the hope is that by explicitly discussing the analytical methods as abstract representations of core aspects of change, researchers will be able to select study designs and analytical procedures that map to and more precisely test their theories of change. The chapter finishes with some notes on implementation, with encouragement for further consideration of nonlinearity, to measure more frequently, and to label parameters with theoretically meaningful names. Keywords: development; experience sampling; exponential; growth; quantitative analysis; sigmoid
Crystallization of the bifunctional biotin operon repressor.

Abstract The bifunctional birA gene product, BirA, which represses the biotin biosynthetic bio operon and also activates biotin in Escherichia coli, has been crystallized. The crystals have the tetragonal space group P4(1)2(1)2, or its enantiomorph, with unit cell dimensions a = b = 114.0 A and c = 60.2 A and diffract to at least 2.3 A resolution. The crystal packing requires that the monomers of the birA protein be arranged as dimers with two-fold symmetry. BirA is the first protein to be crystallized that is both a transcriptional regulator and an enzyme.
Pion Production in Nucleon-Nucleon Scattering

In the last few years high quality data for pion production in proton-proton and neutron-proton scattering have been obtained in the so-called intermediate energy range. These data are often analysed using resonance models. New experiments are being planned to study nonresonant parts of the cross section and also the effects of specific spin amplitudes. The dramatic spin dependence of the elastic nucleon-nucleon scattering may serve here as a guide. The need is felt for unified theories describing simultaneously elastic scattering and pion production.
Antegrade approach for TAVR with total occlusion of the descending aorta.

The antegrade approach for aortic valve interventions is well known but has not been widely used for transcatheter aortic valve replacement (TAVR) procedures. We encountered a patient with no possibility of retrograde access due to a totally occluded abdominal aorta who had a failed attempt at apical TAVR. We describe antegrade TAVR despite occlusion of the abdominal aorta, with the arterial limb of the requisite veno-arterial loop created using bilateral arm access, a novel version of the previously described antegrade approach. © 2013 Wiley Periodicals, Inc.
Are medical marijuana users different from recreational users? The view from primary care.

Background and objectives Marijuana is currently approved for medical use in 23 states. Both clinicians and the lay public have questioned whether users of marijuana for medical purposes are different from users of marijuana for recreational purposes. This study examined similarities and differences in important clinical characteristics between users of medical marijuana and users of recreational marijuana. Methods The sample consisted of 868 adult primary care patients in Washington State, who reported use of medical marijuana (n = 131), recreational marijuana (n = 525), or drugs other than marijuana (n = 212). Retention was over 87% at 3-, 6-, 9-, and 12-month assessments. Results The majority of medical, psychiatric, substance use, and service utilization characteristic comparisons were not significant. However, medical marijuana users had significantly more medical problems, a significantly larger proportion reported >15 days medical problems in the past month, and significantly smaller proportions reported no pain and no mobility limitations (p Conclusions and scientific significance Although our results suggest that there are few distinct differences between medical and recreational users of marijuana, the differences observed, while mostly very small in effect size (
Development of a remote analysis method for underground ventilation systems using tracer gas and CFD in a simplified laboratory apparatus

Following a disaster in a mine, it is important to understand the state of the mine damage immediately with limited information to manage the emergency effectively. Tracer gas technology can be used to understand the ventilation state remotely where other techniques are not practical. Computational fluid dynamics is capable of simulating and ascertaining information about the state of ventilation controls inside a mine by simulating the airflow and tracer distribution. This paper describes a simulation of tracer gas distribution in a simplified laboratory experimental mine with the ventilation controls in various states. Tracer gas measurements were taken in the laboratory experimental apparatus, and used to validate the numerical model. The distribution of the tracer gas, together with the ventilation status, was analyzed to understand how the damage to the ventilation system related to the distribution of tracer gases. Detailed error analysis was performed and the discrepancies between experimental and simulated results were discussed. The results indicate that the methodology established in this study is feasible to determine general ventilation status after incidents and can be transferred to field experiment. Because it is complex to simulate the actual condition of an underground mine in a laboratory, the model mine used is simplified to simulate the general behavior of ventilation in a mine. This work will be used to inform planned on-site experiments in the future and the proposed methodology will be used to compare collected and simulated profiles and determine the general location of ventilation damage at the mine scale.
Modelling impact of urban and upstream nonpoint sources on eutrophication of the Milwaukee River

Abstract This paper describes a study conducted to evaluate the impact of the absence vs. the presence of the North Avenue Damin Milwaukee, Wisconsin, on water quality in the Milwaukee River in terms of conventional constituents, such as DO, chlorophyll a , BOD, and nutrients (N and P). Phytoplanktonic primary production had been recognized earlier as a link between mostly nonpoint nutrient loads to the Milwaukee River and degradation of water quality in the River. A mathematical model of a relevant section of the River was used in the study to estimate the effect of the removal of the Dam on this primary production link. The authors established the model using WASP, which is USEPA's widely used modelling package. The modelled extent of the River included both shallow, productive upstream reaches as well as impounded downstream sections. In the impounded reach of the River where the Dam is located, the simulated removal of the Dam (1) replaced net phytoplankton decay with net phytoplankton growth because of improved light conditions and limited settling; (2) substantially increased the concentration of DO because of the increased photosynthetic production and reduced benthic consumption; and (3) somewhat increased bottle BODS because of the elevated phytoplankton levels. The simulated removal of the Dam eliminated the negative effects of eutrophication at the site while possibly shifting the potential for these effects further downstream towards Lake Michigan.
Comment on “Transplantation of undifferentiated murine embryonic stem cells in the heart: teratoma formation and immune response”

The recently published manuscript by Nussbaum et al. (1) describes teratoma formation and the generation of a host immune response following transplantation of undifferentiated murine embryonic stem cells into the heart. These are important findings, emphasizing the hurdles that need to be overcome before embryonic stem cell therapy can become a clinical reality. We thought it proper to remind the readership of The FASEB Journal of our study detailing undifferentiated embryonic stem cell transplantation into the heart published in 2005 (2). In this study, we presented evidence that undifferentiated embryonic stem cells transplanted into the heart both form teratomas and elicit an immune response by the host. We specifically classified the immune response by examining cellular infiltrates into the heart and presented proof of teratoma formation in both syngeneic and allogeneic recipients. We were somewhat surprised, then, that Dr. Nussbaum’s manuscript does not refer to this previously published work while presenting similar conclusions to those put forth by our study.
Light in the Sea

Light in the sea may be produced by the sun or stars, by chemical or biological processes, or by man-made sources. Serving as the primary source of energy for the oceans and supporting their ecology, light also enables the native inhabitants of the water world, as well as humans and their devices, to see. In this paper, new data drawn from investigations spanning nearly two decades are used to illustrate an integrated account of the optical nature of ocean water, the distribution of flux diverging from localized underwater light sources, the propagation of highly collimated beams of light, the penetration of daylight into the sea, and the utilization of solar energy for many purposes including heating, photosynthesis, vision, and photography.
Trivalent ion exchange in beta″ alumina

Abstract Ion exchange techniques were used to substitute trivalent cations for the sodium ions present in sodium beta″ alumina single crystals. Complete replacement was achieved using Gd3+, Nd3+, and Eu3+ ions in molten salts. The conductivity of Gd3+ beta″ alumina was measured and optical properties of Nd3+ exchanged materials were studied. The trivalent beta″ aluminas appear to be the first solid electrolytes to exhibit rapid trivalent cation motion at moderate temperatures.
Augmentation by citalopram of risperidone-induced monoamine release in rat prefrontal cortex.

Rationale A typical antipsychotics (APDs), e.g. olanzapine and risperidone, have been reported to be effective adjunctive treatment for depression if selective serotonin (5-HT) reuptake inhibitors (SSRIs) alone are ineffective.
Microbial communities and interactions in the lone star tick, Amblyomma americanum

To quantify microbial composition and interactions, we identified prokaryotic communities in the lone star tick (Amblyomma americanum) based on 16S rRNA gene sequences and direct probing. The lone star tick is the vector of emerging diseases and host to additional symbionts of unknown activity, and is representative of other blood-sucking arthropods. We evaluated the potential for vertical (transovarial) transmission by molecular analysis of microbial symbionts from egg and larval clutches. Direct probing of adults (N = 8 populations from the southeastern and midwestern USA, 900 ticks total) revealed three vertically transmitted symbionts: a Coxiella symbiont occurred at 100% frequency, Rickettsia species occurred in 45-61% of all ticks in every population and an Arsenophonus symbiont occurred in 0-90% of ticks per population. Arsenophonus and Rickettsia exhibited significant heterogeneity in frequency among populations. The human pathogens Ehrlichia chafeensis and Borrelia lonestari were rare in most populations. Additional microbes were detected sporadically. Most ticks (78%) were co-infected by two or three microbes but statistical analysis indicated no significant deviation from random co-occurrence. Our findings indicate that microbial communities within lone star ticks are diverse, and suggest that direct probing for a wider range of prokaryotes and application of quantitative polymerase chain reaction (PCR) may provide further insights into microbial interactions within disease vectors. Our results also emphasize the close phylogenetic relationship between tick symbionts and human pathogens, and consistent differences in their prevalence.
Metabolic Bone Disease

Metabolic bone disease may result from genetic, endocrine, nutritional, or biochemical disorders, with variable and often inconsistent imaging findings. For the radiologist, the cornerstone of “metabolic bone disease” has been osteoporosis, osteomalacia, hyperparathyroidism, and Paget’s disease. Over the past three decades, the diagnosis and therapy of these diseases has changed, influenced by biochemical discoveries, imaging advances, and epidemiology studies that together, in turn, have had a strong impact on current radiological practice.
Protein Structure: Nanosecond Crystallographic Snapshots of Protein Structural Changes

In this issue of Science , Srajer et al. (p. 1726) present nanosecond-long snapshots of carbon monoxide dissociating from myoglobin, the first glimpse of a protein at work. In his Perspective, Eaton et al . discuss why this is such a landmark feat and how it was made possible.
Involvement of the endothelin receptor subtype A in neuronal pathogenesis after traumatic brain injury.

Endothelin-1 (ET-1) is a 21 amino acid peptide that has been closely linked to cerebral vasospasm and more recently to oxidative stress after traumatic brain injury. In this study, we have examined the effects of the endothelin receptor subtype A antagonist, Ro 61-1790, on acute cortical neuronal injury and delayed neuronal death in the cerebellum after mild traumatic brain injury. Rats were administered Ro 61-1790 or vehicle for 24 h after injury and euthanized at 1 day, 3 days, or 7 days. Heat shock protein70 (HSP70), a marker of neuronal stress/injury, was immunolocalized in the cortex. Induction of heme oxygenase-1 (HO-1) and enhanced immunoexpression of the complement C3bi receptor, both of which are indicators of cerebellar glial reactivity, and Purkinje cell loss were evaluated in the cerebellum. There was maximal induction of HSP70 in cortical neurons at 24 h postinjury in all animals. Drug treated animals showed significantly fewer HSP70 labeled cortical neurons at this time point. There were fewer reactive glia in the cerebellum of drug treated animals as compared to vehicle controls at 3 days postinjury. However, at 7 days postinjury glial reactivity and Purkinje cell loss were similar in both groups. These findings demonstrate that Ro 61-1790, when administered for the first 24 h postinjury, limits acute neuronal injury in the cortex, transiently influences glial reactivity in the cerebellum, and does not attenuate delayed Purkinje cell death. The latter finding may reflect the duration of infusion of the drug.
Adding International Business to the Core Program via the Simulation Game

This study reports on the feasibility of adding international business to the business core by using a multinational business simulation game in the capstone policy course. The simulation game is not intended to replace an introductory course or substitute for other approaches. It is intended to provide a minimal introduction where none currently exists and perhaps to aid in overcoming the inertia with regard to relevant curriculum changes that are needed to comply with American Assembly of Collegiate Schools of Business (AACSB) guidelines.
Modification of Pullout Behavior of Kevlar Fabric by Zinc Oxide Nanowire Reinforcement

The future development of body armor is to develop a lightweight, and wearable garment system without a loss of ballistic impact resistance. High performance fabrics, such as Kevlar, have been utilized for body armor due to their high energy absorption and lightweight characteristics. However, additional reinforcement is necessary for Kevlar fabric to meet the protection requirements for body armor against typical ballistic threats. Thick layers of fabric or embedded ceramic plates have been used to meet these requirements at the expense of increased weight of the armor and reduced mobility of the user. Thus, much research has been conducted on this topic to increase the ballistic impact resistance of Kevlar fabrics, mainly focused on the understanding and modeling of ballistic impact behavior. Due to the significant effect of damage mechanisms on ballistic impact response, these mechanisms should vastly be studied to better understand the ballistic impact response of Kevlar. When a projectile impacts a woven fabric, the imparted energy is dissipated through several damage mechanisms including tow pullout, local tow failure at the point of impact, and remote tow failure. Among those mechanisms, tow pullout is especially critical in the case of a penetrator with a blunt face impacting a fabric with non-penetrating velocities and is strongly influenced by friction between tows. In this work, we employed a novel method to increase the friction between Kevlar tows by synthesizing zinc oxide nanowires onto the fabric surface. As a result, vertically-aligned zinc oxide nanowires were grown on the fabric surface and tailored to achieve an optimum ballistic performance response reaching an enhancement of up to 390% in tow pullout peak load compared to untreated fabrics. Additionally, the effect of various surface functionalization processes and nanowire morphology is investigated so that an optimum process is developed for an efficient ballistic performance response.Copyright © 2013 by ASME
Stability of a Surface Adlayer at Elevated Temperature : Coronene and Heptanoic Acid on Au(111)

The temperature dependence of the stability of the adlayer formed at the interface between Au(111) and a coronene-heptanoic acid solution is reported. At coronene concentrations above 1.5 x 10 -4 M and at 21 °C, a dense coronene adlayer is observed. At higher temperatures (up to about 60 °C) or in a more dilute solution, a coadsorbed coronene-heptanoic acid structure is observed. This coadsorbed structure is very hardy, surviving exposure to the pure solvent for periods of many minutes and temperatures as high as 105 °C. Loss of the ordered monolayer with high temperature solvent exposure is also accompanied by the formation of at least two additional surface structures involving both coronene and heptanoic acid. This work demonstrates that there is much to be learned by exploring the solution-solid interface at elevated temperatures with STM.
Effect of nitrous oxide analgesia on pneumothorax

Objective: To address whether spontaneous inhalation of 50% nitrous oxide (N2O) for up to 30 minutes adversely affects swine with pneumothorax (PNTX). Methods: Five fasted, female swine (13–17 kg) were sedated with IV ketamine, intubated, and allowed to spontaneously inhale either 50% N2O or room air (RA) in a sequential crossover design in which each animal served as its own RA control. Small (group I, 150 mL), medium (group II, 300 mL), and large (group III, 500 mL) PNTXs were created by instilling air into the left pleural space via an 18-Fr three-way Foley catheter. Changes in PNTX volume, heart rate (HR), central venous pressure (CVP), blood pressure (BP), ECG, and arterial blood gas (ABG) parameters were recorded in separate 10-and 30-minute trials. A 15-minute washout period was given between each trial. Data were analyzed using repeated-measures analysis of variance with post-hoc Tukey's tests. Results: No significant increase in PNTX size was seen during the 10-minute trials. In the 30-minute trials, a statistically significant increase in absolute PNTX size was seen with NzO compared with RA for group I (44 ± 17 vs 16 ± 5 mL, p = 0.02), group II (61 ± 21 vs 26 ± 4 mL, p = 0.01), and group III (62 ± 32 vs 40 ± 5 mL, p = 0.06). No difference in HR, CVP, MAP, ABGs, or ECG were observed between the N2O and RA trials for any size PNTX. No animal developed hemodynamic signs of tension pneumothorax. Conclusion: In this model, spontaneous inhalation of 50% N2O for up to 30 minutes is associated with little risk of hemodynamic or respiratory compromise. Although PNTX size increases with 50% N2O use, the magnitude observed in this animal model is less than previously reported.
Biophysical studies of DNA modified with conformationally constrained nucleotides: comparison of 2′-exo (north) and 3′-exo (south) ‘locked’ templates

The biophysical properties of oligodeoxyribonucleotides (ODNs) selectively modified with conformationally 'locked' bicyclo[3.1.0]hexane pseudosugars (Maier,M.A., Choi,Y., Gaus,H., Barchi,J.J. Jr, Marquez,V.E., Manoharan,M. (2004) Synthesis and characterization of oligonucleotides containing conformationally constrained bicyclo[3.1.0]hexane pseudosugar analogs Nucleic Acids Res., 32, 3642-3650) have been studied by various techniques. Six separate synthetic ODNs based on the Dickerson Drew dodecamer sequence (CGCGAAT*T*CGCG) were examined where each one (or both) of the thymidines (T*) were substituted with a bicyclic pseudosugar locked in either a North (2'-exo) or South (3'-exo) ring pucker. Circular dichroism spectroscopy, differential scanning calorimetry and (1)H NMR spectroscopy were used to examine the duplex stability and conformational properties of the ODNs. Replacement of one or both thymidines with North-locked sugars (RNA-like) into the dodecamer did not greatly affect duplex formation or melt temperatures but distinct differences in thermodynamic parameters were observed. In contrast, incorporation of South-locked sugar derivatives that were predicted to stabilize this standard B-DNA, had the unexpected effect of causing a conformational equilibrium between different duplex forms at specific strand and salt concentrations. Our data and those of others suggest that although DNA can tolerate modifications with RNA-like (North) nucleotides, a more complicated spectrum of changes emerges with modifications restricted to South (DNA-like) puckers.
High apex predator biomass on remote Pacific islands

On coral reefs in Palmyra—a central Pacific atoll with limited fishing pressure—total fish biomass was 428 and 299% greater than on reefs in nearby Christmas and Fanning Islands. Large apex predators, groupers, sharks, snappers, and jacks larger than 50 cm in length, accounted for 56% of total fish biomass in Palmyra on average, but only 7 and 3% on Christmas and Fanning. These biomass proportions are remarkably similar to those previously reported for the remote and uninhabited Northwest Hawaiian Islands (NWHI) and densely populated Main Hawaiian Islands (MHI), although Palmyra’s reefs are dominated in biomass by sharks (44% of the total), whereas the NWHI by jacks (39%). Herbivorous fish biomass was also greater on Palmyra than on Christmas and Fanning (343 and 207%, respectively). These results and previous findings indicate that remote, uninhabited islands support high levels of consumers, and highlight the importance of healthy coral reef ecosystems as reference points for assessment of human impacts and establishment of restoration goals.
Raman Spectroscopic Studies of Silicotitanates

Silicotitanates are nanoporous materials that have been used as selective ion exchangers for removing cesium from waste streams and catalysts for promoting oxidation and hydroxylation reactions. The local bonding configurations and network charge distribution are known to influence the selectivity and reactivity of these compounds. We have synthesized a group of new silicotitanates using sol−gel and solid-state techniques. Raman spectroscopy has been used to systematically examine the vibrational behavior of these compounds. By correlating the variations of Raman spectra with titanium coordinations of these compounds, the relationship between Raman shifts and the local bonding configurations around silicon and titanium is proposed.
Vibro-acoustography with 1.75D ultrasound array transducer for detection and localization of permanent prostate brachytherapy seeds: ex vivo study

Effective brachytherapy procedures require precise placement of radioactive seeds in the prostate. Currently, transrectal ultrasound (TRUS) imaging is one of the main intraoperative imaging modalities to assist physicians in placement of brachytherapy seeds. However, the seed detection rate with TRUS is poor mainly because ultrasound imaging is highly sensitive to variations in seed orientation. The purpose of this study is to investigate the abilities of a new acoustic radiation force imaging modality, vibro-acoustography (VA), equipped with a 1.75D array transducer and implemented on a customized clinical ultrasound scanner, to image and localize brachytherapy seeds in prostatic tissue. To perform experiments, excised cadaver prostate specimens were implanted with dummy brachytherapy seeds, and embedded in tissue mimicking gel to simulate the properties of the surrounding soft tissues. The samples were scanned using the VA system and the resulting VA signals were used to reconstruct VA images at several depths inside the tissue. To further evaluate the performance of VA in detecting seeds, X-ray computed tomography (CT) images of the same tissue sample, were obtained and used as a gold-standard to compare the number of seeds detected by the two methods. Our results indicate that VA is capable of imaging of brachytherapy seeds with accuracy and high contrast, and can detect a large percentage of the seeds implanted within the tissue samples.
Paragangliomas of the head and neck region. A clinical study of 69 patients

Over a 38-year-period 73 paragangliomas from the head and neck region were seen at Memorial Hospital. These occurred in 69 patients. There were 44 carotid body, 13 vagal body, eight jugulo-tympanic, and three nasal paragangliomas. In addition, one each arose in the orbit, larynx, and area of the aortic arch. Sixty-two patients were surgically treated while three received irradiation only and four were observed but not treated. Follow-up was obtained for 94% of the patients. There were six postoperative deaths, five of which occurred before 1945. Of those treated surgically, 37 had no evidence of recurrent tumor while the paragangliomas recurred locally in 11. All patients in the radiation and untreated groups had persistent tumor. Malignant behavior with death due to tumor was observed in five cases (four carotid body and one vagal body paraganglioma). Using modern techniques carotid body and vagal body paragangliomas can usually be managed by surgery alone. Other paragangliomas of the head and neck due to their anatomic location are sometimes best treated by a combination of surgery and radiation or only by radiation therapy.
Physical characterization of a prototype selenium-based full field digital mammography detector.

The purpose of this study was to measure experimentally the physical performance of a prototype mammographicimager based on a direct detection, flat-panel array design employing an amorphous selenium converter with 70 μm pixels. The system was characterized for two different anode types, a molybdenum target with molybdenum filtration ( Mo ∕ Mo ) and a tungsten target with rhodium filtration ( W ∕ Rh ) , at two different energies, 28 and 35 kVp, with approximately 2 mm added aluminum filtration. To measure the resolution, the presampled modulation transfer function(MTF) was measured using an edge method. The normalized noise power spectrum (NNPS) was measured by two-dimensional Fourier analysis of uniformly exposed mammograms. The detective quantum efficiencies (DQEs) were computed from the MTFs, the NNPSs, and theoretical ideal signal to noise ratios. The MTF was found to be close to its ideal limit and reached 0.2 at 11.8 mm − 1 and 0.1 at 14.1 mm − 1 for images acquired at an RQA-M2 technique ( Mo ∕ Mo anode, 28 kVp, 2 mm Al). Using a tungsten technique (MW2; W ∕ Rh anode, 28 kVp, 2 mm Al), the MTF went to 0.2 at 11.2 mm − 1 and to 0.1 at 13.3 mm − 1 . The DQE reached a maximum value of 54% at 1.35 mm − 1 for the RQA-M2 technique at 1.6 μ C ∕ kg and achieved a peak value of 64% at 1.75 mm − 1 for the tungsten technique (MW2) at 1.9 μ C ∕ kg . Nevertheless, the DQE showed strong exposure and frequency dependencies. The results indicated that the detector offered high MTFs and DQEs, but structured noise effects may require improved calibration before clinical implementation.
Reversal of Flow through Chronic Coronary Collateral Vessels

The purpose of this study was to determine whether blood flow through chronic collateral vessels may reverse its direction to supply acutely ischemic myocardium. Ameroid constrictors were placed on the circumflex coronary artery (CCA) of 12 dogs to promote collateral flow (CQ) from the left anterior descending (LAD) to the CCA. Twelve weeks later, myocardial blood flow (MBF) was determined (ml/g/min) using radioactive tracer microspheres. Control LAD subepi-cardial (EPI) and subendocardial (ENDO) flows were 1.17 ± 0.11 and 1.00 ± 0.10 (Mean ± SEM), respectively. CCA EPI and ENDO flows were 1.25 ± 0.12 and 1.12 ± 0.20, respectively. The LAD was then occluded, and MBF to the CCA bed decreased by an average of 0.31 ± 0.03 ml/g/min (P < 0.005). This decrease in MBF quantitated the amount of CQ from the LAD to the CCA bed. An aortocoronary bypass graft was anastomosed to the distal CCA and MBF to the LAD bed immediately increased by an average of 0.30 ± 0.02 ml/g/min (P < 0.005). This increase in MBF represented reversed CQ from the CCA to the acutely ischemic LAD bed. It had a normal transmural distribution (ENDO/EPI = 0.9). Four hours later, total reversed CQ to the LAD bed remained unchanged, but was redistributed toward the EPI (ENDO/EPI = 0.6). These data document that chronic collateral vessels are capable of immediate and sustained conduction of CQ in a retrograde direction and suggest that these collateral vessels may play a role in limiting the degree and transmural extent of ischemic injury when a perioperative myocardial infarction occurs in the vascular bed of a nonbypassed coronary artery.
Binge eating in normal weight and overweight individuals.

The incidence of emotional distress-related eating was investigated through a structured interview given to a sample of 49 men and 51 women, 21 to 55 yr. of age. The interview was designed to uncov...
Stress reactivity and vulnerability to depressed mood in college students

Two studies reported here found that in response to common, minor stressors, stress reactivity (defined as mean stress per stressor) was a stronger predictor than total stress of depressed mood in traditional and nontraditional college men and women. A prospective study found individual reactivity scores varied over time, but relationships between stress and depressed mood held across four monthly assessments. Stress reactivity also accounted for more incremental variance in depressed mood than total stress after controlling for previous depressed mood. When students in the cross-sectional study were classified into reactivity groups, scores for depressed mood increased steadily for students in the very low through high reactivity groups, as did percentages of students with depressed mood scores that might indicate depression in normal populations. This study also found that stress reactivity was more strongly correlated than total stress with neuroticism and its facets (or traits) of depression, anxiety, and vulnerability to stress in the five-factor model of personality. Taken together, these studies suggest that elevated stress reactivity to minor stressors may indicate diminished ability to cope with everyday challenges and may predict increased vulnerability to depressed mood in a normal population.
The utilization of L-amino acids as carbon source by yeasts of the genera Hansenula and Trichosporon.

The assimilation of singleL-amino acids as carbon source in the absence of added nitrogen has been studied for all the described species in the generaHansenula andTrichosporon. The range in the number of amino acids used by individual species varied in the two genera, inHansenula from 0 to 6, inTrichosporon from 0 to 16. These characters were considered in relation to the phylogenetic scheme and ecological origin ofHansenula.
Coordinating pricing and inventory decisions under reference price effects

A well-known concept in the marketing literature is that consumers use prices paid in the past or the current market price as a reference point to assess the value of the current price of an item. These 'reference prices' have been shown to have a significant impact on a consumer's purchase decision and a resulting influence on the selling firm's demand of the item. Recently, considerable research has been conducted on coordinated pricing and inventory decisions; however, very little has recognised the existence of reference prices. Thus, a single-period model is developed that incorporates the effects of reference prices, demand uncertainty and price elasticity on the solution. Numeric analysis indicates that accounting for reference prices can have a substantial impact on the pricing and inventory decisions and the resultant profitability, made by a firm.
Thermodynamic characterization of metal hydrogen systems by assessment of phase diagrams and electrochemical measurements

Abstract The formation of metal hydrides has been investigated theoretically by the use of ternary thermodynamics and experimentally by applying an electrochemical cell technique. A new theoretical method of describing and investigating metal hydrides has been developed. It involves ternary thermodynamics and interprets the hydrogenation reaction by ternary phase diagrams. This method has the advantage over the conventional “pseudobinary” model in that it allows for disproportionation reactions. Furthermore it describes in a visual way the parameters important for hydrogen storage applications, namely plateau pressure and plateau width. Finally it gives a means of predicting hydrogenation reactions. This method has been applied to the family of Mg-based alloys. A new experimental technique for investigating metal hydrides has also been developed. It involves a nonaqueous low temperature molten salt electrochemical cell. Measurements were done with a saturated solution of NaH in the organometallic salt NaAlEt4, where the H− ions are the hydrogen transporting species. Several Mg-based alloys were investigated. The thermodynamic calculations are in very good agreement with the experimental results and are in accordance as well with data published in the literature.
Opiate antagonists enhance the working memory of rats in the radial maze

Two experiments tested the influence of the opiate antagonists naloxone and naltrexone on the spatial working memory of rats in a 12-arm radial maze. In Experiment 1, ten rats were serially forced to visit six randomly selected arms, then were removed from the maze for delays of either 30, 60, or 240 minutes, and then returned to the maze for a free-choice memory test with all 12 arms available. Five minutes into the delay, rats were injected intraperitoneally (IP) with either physiological saline or naloxone (1 mg/kg). When injected with naloxone the rats revisited forced-choice arms less often than when injected with saline during a subsequent free-choice test. In Experiment 2, twelve rats showed a similar facilitation of working memory when injected with the opiate antagonists naltrexone (0.3 mg/kg) and naloxone (1 mg/kg) in comparison to a saline control condition. These findings demonstrate the beneficial effects that opiate antagonists exert on working memory-based performance in the radial maze. They may also resolve conflicting reports about the influence of opiate antagonists on radial maze performance, by suggesting that the choice of measurement and testing conditions are crucial for detecting these effects in working memory procedures.
Poor glycemic control in diabetic patients seeking care in the ED

We hypothesized that diabetic patients in the emergency department (ED) have poorer glycemic control than patients seeking care at primary care clinics. A convenience sample of hemoglobin A1c (HbA1c) values was gathered retrospectively from the ED, Endocrinology, and Family Medicine Clinics. Results were divided into controlled, poorly controlled, and extremely poorly controlled. The only differing pattern of patients (*P < .01) was in the extremely poorly controlled group consisting of 36% of the ED patients (confidence interval [CI], 29.23-42.69; n = 74) vs 18% of the Endocrinology patients (CI, 13.76-22.53; n = 56) and 19% of the Family Medicine patients (CI, 15.98-22.75; n = 105). A frequency distribution of the ED HbA1c values was bimodal. The first peak represents well-controlled diabetic patients. The second, higher peak comprises a larger number of patients (approximate n = 134, 73% of all 207 ED patients) who have poorer glycemic control. We conclude that a large number of ED diabetic patients have poorer glycemic control than the other clinics.
Reversible Addition-Fragmentation Chain Transfer (RAFT) Copolymerization of Fluoroalkyl Polyhedral Oligomeric Silsesquioxane (F-POSS) Macromers (Postprint)

Reversible addition–fragmentation chain transfer (RAFT) polymerization techniques were used to copolymerize an F-POSS macromer with methyl methacrylate (MMA) to produce novel copolymers that possess excellent wetting-resistant behaviour and are the first examples of covalently bound F-POSS nanocomposites for improved surface robustness. These F-POSS/MMA copolymers have also been used to coat cotton fabrics, resulting in both superhydrophobic and oleophobic behaviour.
Depression and Parentification among Adults as Related to Parental Workaholism and Alcoholism.

Investigators examined relationships among levels of depression and parentification in undergraduate university students. Instrument scores were used to identify participants as (a) adult children with alcoholic parents, (b) adult children with workaholic parents, (c) adult children with at least one parent who was both alcoholic and workaholic, and (d) a comparison group composed of adult children who met none of the other group criteria. Children of workaholics scored significantly higher on measures of depression and parentification, and they reported parents worked more hours than did parents of children of alcoholics and the comparison group. Children of alcoholics scored significantly higher than the comparison group on the measure of parentification. Children with parents who met both descriptions scored significantly higher than children of alcoholics and the comparison group on the three dimensions described and on combined number of hours both parents worked.
Preparation of radioactive epsilon-N-methylated lysines not involving elaborate organic synthesis.

Abstract A simple method to prepare small quantities of radioactive e- N -methylated lysines for use as analytical standard markers, which does not involve elaborate organic synthesis, is highly desired in numerous research applications. The method in this report involved growing Neurospora crassa or Salmonella typhimurium in the presence of uniformly labeled [ U- 14 C ] lysine or reductively methylating a protein with [ 14 C]formaldehyde at pH 9.0. The radiolabeled proteins were then isolated and hydrolyzed in 6 n HCl. Finally, the radioactive methylated lysines in the acid hydrolysates were isolated by Dowex 50 column chromatography.
Tryptic and chymotryptic methionine peptide analysis of the in vitro translation products specified by the transforming region of adenovirus type 2.

Abstract Early region 1 (El) cytoplasmic RNAs of adenovirus type 2 were translated in vitro . Structural relationships between these proteins were then established by tryptic and chymotryptic digestion and two-dimensional peptide mapping. This analysis also allowed a direct comparison of these proteins with polypeptides isolated from early infected cell extracts and previously assigned to E1 by indirect means ( M., Green, W. S. M. Wold, K. H. Brackmann, and M. A. Cartas, 1979 , Virology 97, 275–286). E1a (0–4.5%) RNA encodes five proteins in vitro : 35K, 41K, 47K and 53K at early times, and a 28K protein at later times in infection. These five proteins are all highly related by peptide mapping analysis, and are also related to a group of four proteins isolated from cell extracts prepared early in infection. E1b (4.5–11.0%) early RNA encodes 52K and one or more 15K proteins in vitro . The 52K protein shares tryptic peptides with a 53K immunoprecipitated T antigen. A 15K protein shares some peptides with the 52K protein and with several proteins isolated from infected cells. At intermediate to late times, E1b RNA encodes a 12K protein that corresponds to the virion structural polypeptide IX. These data also permit the correlation of E1 proteins synthesized in vitro with the polypeptides predicted by E1 sequence analysis.
Transmission of equine infectious anaemia virus from a horse negative to agar gel immunodiffusion testing

Summary Equine infectious anaemia (EIA) virus was recovered from a stallion serologically negative to the agar gel immunodiffusion test (AGID). Viral residence in the subject was demonstrated by inoculating 2 susceptible horses, one with whole blood and the other with washed leucocytes from the stallion. The recipients developed clinical signs of EIA and reacted positively to AGID. Resume Le virus de l'anemie infectieuse equine (EIA) a ete isole d'un etalon serologiquement negatif au test d'immuno diffusion sur gelose. La presence du virus fut demontree par inoculation de deux chevaux, l'un avec du sang complet, l'autre avec des leucocytes laves. Les chevaux inocules montrerent dessignes cliniques d'anemie infectieuse et reagirent positivement au test d'immuno-diffusion. Zusammenfassung Das Virus der equinen infektiosen Anaemia (EIA) konnte aus einem Hengst isoliert werden, der im Agargel-Immunodiffusions-test (AGID) ein negatives Resultat erbracht hatte. Das Vorhandensein des Virus in diesem Tier wurde durch eine Uebertragung auf zwei empfangliche Pferde (eines erhielt Vollblut, das andere gewaschene Leukocyten) bewiesen werden. Die Empfanger entwickelten die klinischen Symptome der infektiosen Anaemie und reagierten positiv im AGID.
Information networks: Definitions and message transfer models

A mathematical definition of an information network is constructed with the purpose of developing a theory useful in answering practical questions concerning information transfer. An information network includes: (1) users, (2) information resources, (3) information centers, and (4) the total information transfer structure linking (1), (2), and (3). Emphasis is placed on the message transfer structure, as distinguished from the document transfer structure, to identify some basic network configurations. Any message transfer structure is shown in graph theory concepts to be either isographic or nonisographic. Among the isographic structures, the cyclic and decentralized networks are defined. The strictly hierarchical network is also defined, and the 2-regular network, reflected in the ARPA design, is identified. Measures of network structure, in particular the accessibility and flexibility in message transfer, are developed. These measures for the basic structures are used to characterize more general structures. While some comparisons of message transfer structures can be made, development of more comprehensive measures is a necessity.
Improved techniques for measuring in vitro the geometry and pressure distribution in the human acetabulum--I. Ultrasonic measurement of acetabular surfaces, sphericity and cartilage thickness.

Abstract A unique, highly accurate, non-contacting method for measuring the loaded and unloaded shape and thickness of acetabular articular cartilage employing ultrasound is described. The unloaded cartilage surface is shown to be spherical with localized deviations less than 150 μm. The calcified cartilage interface is quite irregular with deviations from sphericity of 500 μm. The centers of the best-fitting spheres to the cartilage surface and the calcified interface are displaced resulting in decreased cartilage thickness in the anterior medial aspect.