cssi/SciSciGPT-SciSciNet huggingface dataset:
Protein folding in the hydrophobic-hydrophilic (HP) is NP-complete

ABSTRACT One of the simplest and most popular biophysical models of protein folding is the hydrophobic-hydrophilic (HP) model. The HP model abstracts the hydrophobic interaction in protein folding by labeling the amino acids as hydrophobic (H for nonpolar) or hydrophilic (P for polar). Chains of amino acids are configured as self-avoiding walks on the 3D cubic lattice, where an optimal conformation maximizes the number of adjacencies between H's. In this paper, the protein folding problem under the HP model on the cubic lattice is shown to be NP-complete. This means that the protein folding problem belongs to a large set of problems that are believed to be computationally intractable.
Separation of Liquid Solutions by Contained Liquid Membranes

Abstract The technique of contained liquid membranes (CLM) for liquid solution separation is discussed. The CLM is obtained by confining the membrane liquid between two sets of microporous hollow fibers (MHF). The lumen of the hollow fiber carries the feed or the strip solution under proper phase pressure condition vis-a-vis the membrane phase. Various possible structural configurations of the CLM are illustrated with respect to the nature of microporous hollow fiber substrate, the feed solution and the liquid membrane. The contributions of different resistances to the solute transport rate are identified. Some basic experimental data obtained in small CLM permeators are presented for two systems with organic liquid membranes to illustrate how steady state separation is achieved after an initial unsteady period. The considerable advantages of the CLM structure over more traditional liquid membrane techniques such as supported liquid membrane (SLM) with respect to membrane stability, membrane regeneration ...
Reduktion von N2O an einem μ4‐sulfidverbrückten vierkernigen aktiven CuZ‐Zentrum

Die Reduktion von Distickstoffoxid (N2O) ist eine chemische Herausforderung, sowohl was die selektive Oxidation organischer Substrate durch N2O anbelangt als auch die Beseitigung von N2O als Treibhausgas. Die Reduktion von N2O ist thermodynamisch gunstig, aber kinetisch gehemmt und erfordert die Aktivierung von N2O durch Ubergangsmetallzentren. In biologischen Systemen ist die Reduktion von N2O der abschliesende Denitrifizierungsschritt im bakteriellen Stickstoffkreislauf und wird von dem Enzym Distickstoff-Reduktase katalysiert, dessen aktives Zentrum aus einem μ4-sulfidverbruckten vierkernigen CuZ-Cluster mit vielen ungewohnlichen spektroskopischen Eigenschaften besteht. Aktuelle Untersuchungen fuhrten zu einer detaillierten Beschreibung der elektronischen Struktur des CuZ-Clusters im Ruhezustand und im katalytisch aktiven Zustand. Dies fuhrt zum besseren Verstandnis der Rolle dieses vierkernigen Kupferclusters bei der Aktivierung und Reduktion von N2O.
The Second Shock: A Qualitative Study of Parents' Perspectives and Needs during Their Child's Transition From School to Adult Life

This paper describes a study in the tradition of qualitative research (Biklen & Moseley, 1988; Bogdan & Biklen, 1992; Taylor & Bogdan, 1984) and examines the transition from school to adult-life process. This study employed methodology similar to other investigations that have described the nature of relationships between families and professionals (Ferguson, Ferguson, Jeanchild, Olson, & Lucyshyn, 1993) and investigated the transition process from the perspective of those who experience it (Ferguson, Ferguson, & Jones, 1988; Zetlin & Hosseini, 1989; Zetlin & Turner, 1985). Results indicate that parents of students who are involved in the transition process have a vision for the future of their child. They measure the quality of school services, the potential for future happiness and their faith in the transition process by how their child is succeeding in moving toward that vision. Implications for practice and policy are discussed.
Analysis of time-series measurements of sediment temperature for identification of gaining vs. losing portions of Juday Creek, Indiana

Abstract Identifying locations at which groundwater and surface water interact can be important in a variety of contexts including the development of water budgets, the determination of migration pathways for nutrients and contaminants, and the estimation of thermal budgets along small water bodies. Some difficulty has been experienced in identifying locations of inflows over large regions when detailed groundwater information is not known. A method is suggested herein for the identification of the location of inflows-outflows in both creeks and streams. This method, applied to a small creek in northern Indiana, involves measurement over time of both the sediment temperature and the temperature at the base of the overlying water column. The results are used to define reaches along the creek which are gaining and reaches along the creek which are losing. These results are supported by independent measurements of groundwater elevations at several points along the stream. It is argued that this method provides an excellent screening tool for the identification of gaining and losing reaches of small waterways.
Taste-Potentiated Odor Aversion Learning in Rats with Lesions of the Insular Cortex

The current study assessed the influence of excitotoxic lesions of the insular cortex (IC) on taste-potentiated odor aversion (TPOA) learning. Water-deprived rats initially received a single odor-toxicosis or odor/taste-toxicosis pairing and were subsequently tested, in separate trials, with the odor and the taste stimulus. Indicating TPOA, neurologically intact rats conditioned with the odor/taste compound stimulus acquired significantly stronger odor aversions than normal rats conditioned with the odor stimulus. IC lesions disrupted TPOA, conditioned taste aversion and taste neophobia. The finding that taste did not potentiate odor aversion learning in the IC-lesioned rats provides support for the "within-compound association" analysis but is inconsistent with the "sensory-and-gate" account of TPOA learning.
Convective overshooting in the evolution of very massive stars

Possible convective overshooting in stars of 30-120 solar masses are considered, including a merger between the convective core and the intermediate zone, and penetration by the outer convection zone into the hydrogen-shell region when the star is a supergiant. Convective mixing between the core and inner envelopes is found to lead to a brief renewal of hydrogen burning in the core, and a moderate widening of the main sequence bond in the H-R diagram. Deep penetration by the outer convection zone is found to force the star out of the red supergiant configuration and into a configuration near the main sequence. This would account for the apparent spread of the uppermost part of the main sequence and the concentration of luminous supergiants towards earlier spectral types. In addition, heavy mass loss need not be assumed to achieve the points of agreement, and are tentatively considered unimportant from an evolutionary point of view.
Ancestry and evolution of seasonal migration in the Parulidae

Seasonal migration in birds is known to be highly labile and subject to rapid change in response to selection, such that researchers have hypothesized that phylogenetic relationships should neither predict nor constrain the migratory behaviour of a species. Many theories on the evolution of bird migration assume a framework that extant migratory species have evolved repeatedly and relatively recently from sedentary tropical or subtropical ancestors. We performed ancestral state reconstructions of migratory behaviour using a comprehensive, well-supported phylogeny of the Parulidae (the ‘wood-warblers’), a large family of Neotropical and Nearctic migratory and sedentary songbirds, and examined the rates of gain and loss of migration throughout the Parulidae. Counter to traditional hypotheses, our results suggest that the ancestral wood-warbler was migratory and that losses of migration have been at least as prevalent as gains throughout the history of Parulidae. Therefore, extant sedentary tropical radiations in the Parulidae represent losses of latitudinal migration and colonization of the tropics from temperate regions. We also tested for phylogenetic signal in migratory behaviour, and our results indicate that although migratory behaviour is variable within some wood-warbler species and clades, phylogeny significantly predicts the migratory distance of species in the Parulidae.
Periodically expanding discounted debt: a threat to fiscal policy sustainability?

This paper models the behaviour of discounted US debt using a Markov-switching time series model. The significance of modelling fiscal policy within this framework derives from the implications it has for long-term sustainability. The two-regime framework used in this paper identifies periods where the present value of US Federal debt is expanding versus periods when it is collapsing. Using an updated data series from Hamilton and Flavin (1986), a test is conducted to establish if the expanding periods pose a threat to the long-run sustainability of fiscal policy. For the USA, it is found that they do not. Copyright © 2005 John Wiley & Sons, Ltd.
US Bankers' Attitudes and Internationalisation: The Case of the Export Trading Company Act

A bank's attitude towards export‐stimulating legislation is influenced by various stages of bank internationalisation and it can be concluded that internationalisation factors which have helped researchers explain export behaviour and attitudes among manufacturing firms have worked equally well for the banking industry. A survey of 600 US banks (drawing a response rate of 42 per cent) into bankers' attitudes to the Export Trading Company Act (ETCA) of 1982, also has implications for government policy in that size of bank is useful for segmentation and thus export promotion purposes: large banks are favourable towards ETCA, while small banks are largely unaware of the legislation.
Methods for high-voltage bias testing of PV modules in hot and humid climate

The accelerated tests currently carried out on PV modules reduce the infant mortality as well as improve the production techniques during the manufacture of PV modules. However, the accelerated tests do not completely duplicate the real world operating conditions of PV modules. Hence it is essential to deploy PV modules in the field for extended periods in order to estimate the degradation, if any, as well as to elucidate the degradation mechanisms. Moreover, PV modules should be tested by specially designed tests in harsh climates. At Florida Solar Energy Center (FSEC) high-voltage bias testing of PV modules was carried out in hot and humid climate with the individual modules biased at +/- 600 V. It was observed that the leakage currents flowing from the PV circuit to the ground is directly proportional to the bias voltage. PV systems with maximum voltage of 1000 V are installed in Europe and elsewhere which means higher leakage currents will be produced in the PV modules. Based on this fact and the earlier observations, high voltage bias testing of c-Si PV modules specially designed for high voltage operation was carried out in hot and humid climate with the individual modules biased at +/-1500 V at FSEC and higher. This paper provides results of high voltage bias testing of PV modules. The results indicate that the test can be considered as reliable metric in determination of the long term performance of PV modules.
Unusual behavior of 34:10,11-bis(2',3'-quinolino)tricyclo-[6.3.0.02,6] undecane upon attempted monoprotonation with triflic acid

Abstract The title compound (5, 73%) and the corresponding bis(8'-methoxy) derivative (6, 62%.) were synthesized via base promoted Friedlander condensations of tricyclo[6.3.0.02,6] undecane-3,ll-dione (3) with excess ortho -minobenzaldehyde and with 2-amino-3-methoxybenzaldehyde, respectively. Only diprotonated 5 could be isolated via reaction of the title compound with triflic acid. X-ray crystal structures of 5 and of two polymorphic forms of diprotonated 5 (i.e., 7a and 7b) are reported.
Effect on Supersonic Jet Noise of Nozzle Plenum Pressure Fluctuations

Demonstration that pressure fluctuations in the plenum chamber to a supersonic nozzle can strongly increase the noise radiated from the jet plume. The correlation shows that jet noise acoustic efficiency increases from 0.3% to 0.8% (or 4 dB) when the chamber roughness intensity increases from essentially no plenum chamber roughness to 2%. A roughness level of 2% has been observed in some turbojet engines. It is concluded that the reduction or elimination of plenum chamber pressure fluctuations may be an important method of reducing the total noise from jet engines.
Quipazine exacerbation of a hyperkinetic syndrome: involvement of brain dopamine and serotonin.

Quipazine (5-25 mg.kg-1, s.c.) was given to rats in which a hyperkinetic syndrome had been previously induced by administration of beta,beta'-iminodipropionitrile (IDPN). Quipazine produced a significant increase in the circling behavior and choreiform head and neck movements, characteristic of the syndrome. This response could be blocked by pretreatment with the serotonin antagonists, SQ10, 631 (25 mg.kg-1, i.p.) and methysergide (5.0 mg.kg-1, i.p.), as well as the dopamine receptor antagonist, haloperidol (0.5 mg.kg-1, i.p.). These observations are discussed with respect to the nature of the involvement of brain serotonergic and dopaminergic systems in quipazine action on these hyperkinetic disturbances.
Selecting languages for pedagogical tools in the computer science curriculum

The selection of languages for use as pedagogical aids in the teaching of computer science is still a big issue at most universities. The rebellion against FORTRAN has given rise to numerous heirs to the throne, eg, PL/1, ALGOL, PASCAL, etc. In deciding how to resolve this issue small departments have to consider the effect the decision might have on the productivity of their faculty. The analysis of this problem as viewed at SIU-Carbondale is described within. The analysis is performed by applying a set of criteria to a list of potential languages.
Stony meteorite porosities and densities: A review of the data through 2001

In this review, we summarize the data published up to December 2001 on the porosity and density of stony meteorites. These data were taken from 925 samples of 454 different meteorites by a variety of techniques. Most meteorites have densities on the order of 3 to 4 g/cm^3, with lower densities only for some volatile-rich carbonaceous meteorites and higher densities for stony irons. For the vast majority of stones, porosity data alone cannot distinguish between different meteorite compositions. Average porosities for most meteorite classes are around 10%, though individual samples can range as high as 30% porosity. Unbrecciated basaltic achondrites appear to be systematically less porous unless vesicles are present. The measured density of ordinary chondrites is strongly controlled by the amount of terrestrial weathering the sample has undergone with porosities steadily dropping with exposure to the terrestrial environment. A theoretical grain density based on composition can model "pre-weathered" porosities. The average model porosity for H and LL chondrites is 10%, while L chondrite model porosities average only 6%, a statistically significant difference.
Isolation technique alters eosinophil migration response to IL-8.

Abstract Disparate reports exist on the eosinophil chemotactic capacity of interleukin-8 (IL-8). We hypothesized that the difference is due to the methods used to purify eosinophils. We therefore compared the eosinophilotactic capacity of IL-8 on human cells isolated by Percoll (positive selection) vs. magnetic cell separation system (MACS) (negative selection). Discontinuous Percoll gradients were preceded by dextran and Ficoll-Paque steps, and followed by gelatin wash and red blood cell (RBC) lysis. MACS isolation included: Percoll 1.090 g/ml layering and RBC lysis; incubation with CD16 antibody conjugated to magnetic beads (to bind neutrophils); and isolation of eluate from column positioned in magnet. Percoll isolated eosinophils migrated to IL-8 in a dose-responsive fashion. Although MACS isolation provided a greater number and higher purity of eosinophils, these eosinophils did not migrate to IL-8. Neither dextran sedimentation, Ficoll-Paque and Percoll prior to, nor Percoll discontinuous gradients subsequent to, MACS isolation reversed the negative chemotactic response. Moreover, Percoll-isolated eosinophils further purified with CD16 MicroBeads no longer chemotactically responded to IL-8. This inhibition was not due to change in eosinophil purity, a loss of eosinophil adhesion molecules or activation markers, the presence of a soluble neutrophil or eosinophil inhibitor or the effect of the magnet. Thus, the technique used to isolate eosinophils clearly affects the chemotactic responsiveness of this cell to IL-8. Science several in vivo studies suggest that IL-8 is an eosinophil chemoattractant, Percoll isolation of these cells might be more appropriate for studies involving eosinophil chemotactic responses to IL-8.
Airway purinergic responses in healthy, atopic nonasthmatic, and atopic asthmatic subjects exposed to ozone.

Context: Ozone exposure triggers airway inflammatory responses that may be influenced by biologically active purine metabolites.Objective: To examine the relationships between airway purine metabolites and established inflammatory markers of ozone exposure, and to determine if these relationships are altered in individuals with atopy or asthma.Materials and methods: Mass spectrometry was utilized to measure concentrations of purine metabolites (adenosine monophosphate [AMP], adenosine, hypoxanthine, uric acid) and non-purine metabolites (taurine, urea, phenylalanine, tyrosine) in induced sputum obtained from 31 subjects with normal lung function (13 healthy controls, eight atopic nonasthmatics, and 10 atopic asthmatic [AA]) before and 4 h after ozone exposure.Results: At baseline, the purines AMP and hypoxanthine correlated with multiple inflammatory markers including neutrophil counts and the cytokines interleukin (IL)-6, IL-8, tumor necrosis factor alpha (TNF-α), and IL-1β (r ranged from 0.41 to 0.66, a...
OWA trees and their role in security modeling using attack trees

We introduce the idea of an OWA node as an extension of the ''and/or'' node and use them to generalize ''and/or'' trees to OWA trees. We provide a semantics for an OWA node. Specifically while an ''or'' node requires only one of the children to be satisfied and an ''and'' node requires ''all'' the children be satisfied the OWA node allows us to model situations in which there is some probabilistic uncertainty in the number of children that need be satisfied. We then use these OWA nodes in the security related problem of constructing attack trees. Techniques for the evaluation of an OWA attack tree for the overall probability of success and cost of an attack are provided. A method is provided for describing different types of attackers.
Exploring the error characteristics of thin ice cloud property retrievals using a Markov chain Monte Carlo algorithm

[1] It is commonly assumed that ice cloud property retrievals are well-constrained so that a look-up table or an optimal estimation approach can be used to provide a unique solution. However, because of nonlinearities in radiative transfer models, error characteristics of retrieved ice cloud properties are generally not well-known. The Markov chain Monte Carlo (MCMC) approach, which represents information from prior knowledge, observations, and the forward model probabilistically, allows for an accurate assessment of the solution space and the nature of uncertainties in the retrieval. In this paper, an MCMC algorithm is used to examine the sensitivity of infrared split window retrieved ice water path and ice particle effective radius to changes in cloud top height, cloud geometric thickness, and the assumed ice crystal shape. In addition, we assess the effect of particle settling, changes to observation error magnitude, and the implementation of a log-normal error distribution on the retrieval results. It is found that, though the effects of uncertainty in cloud top height are not insignificant, uncertainty in the ice crystal shape contributes most to the uncertainty in the retrieval and gives rise to the potential for multiple solutions. Reduction of observation error and the assumption of particle settling serve to change the preferred combination of crystal shapes in the volume but do not eliminate the potential for a multimodal result. Application of the MCMC algorithm to a scene reveals that both the nature and magnitude of retrieval errors exhibit a strong dependence on cloud optical depth.
THE ULTRASTRUCTURE OF HUMAN EMBRYONIC MYOCARDIUM.

Human embryonic myocardial tissues ranging from eight to eighteen weeks of development were prefixed and dissected in buffered formaldehyde, postfixed in buffered OsO4 and processes for Epon embedding. At these stages of development the myocardial cells contain an abundance of sarcoplasm with a sparse random distribution of myofibrils that frequently appear branched. The A, I and Z bands exhibited in the adult myocardial cells are also observed in these stages of development. However, the M line is only slightly apparent, while no H band was observed. The mitochondria are not arranged in parallel arrays as found in the adult, but appear to be randomly distributed throughout the interfibrillar sarcoplasm. An array of tubules, cisternae and vesicles that comprise the sarcoplasmic reticulum is also distributed throughout the interfibrillar sarcoplasm. In some areas this tubular system appears as vesicles with small dense granules along its outer surface, while in other areas it appears smooth. The distribution and orientation of the sarcoplasmic reticulum is far less pronounced in the embryonic stages examined in this study than that reported for the adult myocardium. Dense granules (150 to 350 A) appear as clusters or aggregates of granules in the sarcoplasm and are similar to the glycogen granules described by other investigators. The intercalated disc is observed at the junction of two opposing cells and occurs with less frequency than the intercalated disc in the adult myocardium.
Projections of the retinorecipient pretectal nuclei in the pigeon (columba livia)

We have used anterograde autoradiographic and retrograde HRP techniques to investigate the efferent connections of the retinorecipient pretectal nuclei in the pigeon. In the accompanying paper we identified these nuclei in the pigeon as the nucleus lentiformis mesencephali–pars lateralis and pars medialis, the tectal gray, the area pretectalis, and pretectalis diffusus. Although there are reports of a few of the projections of these nuclei, they had not previously been the subject of a detailed study. We found that different cell types in the lentiformis mesencephali, pars medialis and the lentiformis mesencephali, pars lateralis have descending projections to different targets. These targets include the inferior olive, the cerebellum, the lateral pontine nucleus, the nucleus papillioformis, the nucleus of the basal optic root, the nucleus mesencephalicus profundus, pars ventralis, the nucleus principalis precommissuralis, and the stratum cellulare externum. We found that a few cells in the lentiformis mesencephali project to the medial pontine nucleus, but that a much heavier projection arises from the nucleus laminaris precommissuralis, which is medial to the nucleus lentiformis mesencephali, pars medialis. The tectal gray has predominantly ascending projections to the diencephalon. The nuclei that it projects to are the nucleus intercalatus thalami, the nucleus of the ventral supraoptic decussation, the nucleus posteroventralis, the ventral lateral geniculate nucleus, the nucleus dorsolateralis medialis, and the nucleus dorsolateralis anterior. The tectal gray also projects topographically to layers 4 and 8–13 of the optic tectum. Area pretectalis has both ascending and descending projections. It has ipsilateral ascending projections to the nucleus dorsolateralis anterior, pars magnocellularis, the nucleus lateralis anterior, and the nucleus ventrolateralis thalami. It has ipsilateral descending projections to the central gray, the nucleus of the basal optic root, pars dorsalis, the lateral pontine nucleus, and the deep layers of the optic tectum. It has contralateral projections to the area pretectalis, the nucleus Campi Foreli, the interstitial nucleus of Cajal, the nucleus of Darkschewitsch, the cerebellum, and the Edinger-Westphal nucleus. The efferent projections of pretectalis diffusus are limited. It projects contralaterally to the pretectalis diffusus, and ipsilaterally to the nucleus of the ventral supraoptic decussation, the lateral pons, and the cerebellum. Our results demonstrate that, by way of their ascending and descending projections, the retinorecipient pretectal nuclei can exert important influences on the range of visuomotor functions in which they participate. We know that area pretectalis mediates the pupillary light reflex (Gamlin et al., '84) and that the lentiformis mesencephali is involved in optokinetic nystagmus (McKenna and Wallman, '85). However, to our knowledge, other potential roles of the retinorecipient pretectal nuclei have not been identified.
Three-dimensional Brain Current Source Reconstruction from Intra-cranial ECoG Recordings

We have investigated 3-dimensional brain current density reconstruction (CDR) from intracranial electrocorticogram (ECoG) recordings by means of finite element method (FEM). The brain electrical sources are modeled by a current density distribution and estimated from the ECoG signals with the aid of a weighted minimum norm estimation algorithm. A series of computer simulations were conducted to evaluate the performance of ECoG-CDR by comparing with the scalp EEG based CDR results. The present computer simulation results indicate that the ECoG-CDR provides enhanced performance in localizing single dipole sources which are located in regions underneath the implanted subdural ECoG grids, and in distinguishing and imaging multiple separate dipole sources, in comparison to the CDR results as obtained from the scalp EEG under the same conditions. We have also demonstrated the applicability of the present ECoG-CDR method to estimate 3-dimensional current density distribution from the subdural ECoG recordings in a human epilepsy patient. Eleven interictal epileptiform spikes (seven from the frontal region and four from parietal region) in an epilepsy patient undergoing surgical evaluation were analyzed. The present promising results indicate the feasibility and applicability of the developed ECoG-CDR method of estimating brain sources from intracranial electrical recordings, with detailed forward modeling using FEM.
Experiments and Analysis of Effect of Calender Gaps on Melting of PVC Powders in an Intermeshing Counter-rotating Twin-screw Extruder

Abstract Our ultrasound in-line monitoring studies revealed that dispersion or dissipation melting mechanism played a dominant role during melting of unplasticized polyvinyl chloride (uPVC) in an intermeshing counter-rotating twin-screw extruder. It is found that calendering effect between two screws contributes to the melting of PVC particles, and results in dispersion or dissipation melting. Thus, in this paper, a dispersed melting model in calender gaps is considered to predict polymer melting length in terms of numbers of calender gaps. Effects of screw geometries (channel depth, calender gap clearance) and processing conditions including screw speed and leakage flow on melting length are discussed for particle-filled fluid models. The calculated results are compared with experimental observations by both “screw pulling out” method and ultrasound in-line monitoring method. Ultrasound in-line monitoring provides a solution to overcome the time delay occurred in screw-pulling out method.
Afferent fibers with multiple encoding sites.

Abstract A primary afferent fiber with the capability for initiating impulses at more than one sensory terminal belongs to one of two classes. The first, termed simultaneous reset, appears to be more common in nature, including most, if not all myelinated afferents. Analysis of this class shows that multiple encoding sites increase mean discharge and produce significantly less variability in discharge rate of the parent axon. The second class, termed non-simultaneous reset, is far more difficult to analyze, although multiple encoding sites belonging to this class would appear to be limited to C fibers with large areas of innervation. Some possible utilities of the simultaneous reset class include the allowance for both non-disruptive multiplexing of information from different transducers, and for trophic activities of growth and repair without interfering with ongoing function.
Intestinal perforation due to cytomegalovirus infection in patients with AIDS.

Intestinal perforation due to cytomegalovirus (CMV) infection in patients with AIDS is the most common life-threatening condition requiring emergency celiotomy in these patients. The authors describe a patient with AIDS with intestinal perforation due to CMV infection, and review 14 additional cases reported in the English-language surgical literature. The diagnostic triad of pneumoperitoneum on x-ray, evidence or history of CMV infection, and AIDS occurred in 70 percent of patients. The most common site of intestinal perforation was the colon (53 percent), followed in frequency by the distal ileum (40 percent) and appendix (7 percent); perforation usually occurred between the distal ileum and splenic flexure of the colon. Colonoscopy, rather than sigmoidoscopy, is recommended as a screening examination in patients with AIDS suspected of having colonic uleration due to CMV infection. Multiple biopsies of ulcerated tissue should be obtained. Gross and microscopic analyses of involved intestinal tissue reveal the characteristic findings of ulceration and CMV infection. Despite aggressive therapy, the operative mortality rate in patients with AIDS with intestinal perforation due to CMV infection was 54 percent and the overall mortality rate was 87 percent. Postoperative complications occurred in most patients and consisted mainly of systemic sepsis and pneumonia caused by Pneumocystis carinii infection. An increased awareness of this syndrome by physicians frequently called on to manage patients with AIDS is recommended.
Concanavalin a stimulation of plasminogen activator production in pig kidney cells in culture

Addition of subtoxic doses of the lectin concanavalin A to growing subconfluent monolayer cultures of pig kidney cells causes an increase in extra- and intracellular plasminogen activator activity which is reversibly inhibited by actinomycin D, cycloheximide and alpha-methyl-D-mannoside. These results suggest that cell surface events may play an important modulatory role in plasminogen activator production.
Severe respiratory depression following nasalinstillation of tetrahydrozoline hydrochloride

Summary A case of severe respiratory depressionfollowing the nasal instillation of tetrahydrozoline hydrochloride nose drops in a 10-week-old boy is described. The pharmacology and toxicology of this drug and related compounds are briefly discussed. Caution is advised in the administration of this medication to infants.
A Comparison Between Contour Elevation Data Sources for DEM Creation and Soil Carbon Prediction, Coshocton, Ohio

A raster and vector GIS was created for the North Appalachian Experimental Watershed (NAEW) from legacy (1960) 1:2,400-scale contour maps. The intent of the study was to use terrain data for the spatial modeling of soil organic carbon. It was hypothesized that DEMs derived from these data would be more accurate and therefore more useful for terrain-based soil modeling than those from USGS 1:24,000-scale contour data. Central tasks for this study were to digitally capture the 1:2,400-scale maps, convert digital contour data sources to raster DEMs at multiple resolutions, and derive terrain attributes. A flexible approach was adopted, using software outside of mainstream GIS sources where scientifically or practically advantageous. Elevation contours and streamlines were converted to raster DEMs using ANUDEM. DEMs ranging in resolution from 0.5–30 m were tested for accuracy against precision carrier-phase GPS data. The residual standard deviation was 1.68 meters for the USGS DEM and 0.36 meters for the NAEW DEM. The optimal horizontal resolution for the NAEW DEM was 5 m and for the USGS 10 m. Five and 10 m resolution DEMs from both data sources were tested for carbon prediction. Multiple terrain parameters were derived as proxies for surficial processes. Soil samples (n = 184) were collected on four zero-order watersheds (conventional tillage, no-till, hay and pasture). Multiple least squares regressions (m.l.s.) were used to predict mass C (kg m−2, 30 cm depth) from topographic information. Model residuals were not spatially autocorrelated. Statistically significant topographic parameters were attained most consistently from the 5 m NAEW DEM. However, topography was not a strong predictor of carbon for these watersheds, with r2 ranging from 0.23 to 0.58.
Pupil Involvement in Patients With Diabetes-Associated Oculomotor Nerve Palsy

Objective To derive a reliable estimate of the frequency of pupil involvement in patients with diabetes-associated oculomotor nerve palsy. Patients and Methods In this prospective study, standardized enrollment criteria were employed to identify 26 consecutive patients with diabetes-associated oculomotor nerve palsy who were evaluated in a referral-based, outpatient neuro-ophthalmology practice. A pupil ruler accurate to within 0.5 mm was used to measure pupil diameters using a standardized procedure. The degree of anisocoria, if present, was recorded at each office visit until the ophthalmoplegia had resolved. Descriptive statistics were used to identify the frequency and characteristics of pupil involvement. Results Internal ophthalmoplegia occurred in 10 (38%) of 26 patients. The size of the anisocoria was 1 mm or less in most patients. None of the patients had a fully dilated unreactive pupil. Conclusions Pupil involvement in patients with diabetes-associated oculomotor nerve palsy occurs more often than has been previously recognized, although the degree of anisocoria in any 1 patient is usually only 1 mm or less. Some characteristics of the internal ophthalmoplegia may help to distinguish diabetic ophthalmoplegia from injury of the oculomotor nerve caused by aneurysmal compression.
Outcome monitoring of fluvastatin in a Department of Veterans Affairs Lipid Clinic

Abstract The aggressive lipid-lowering goals recommended by the second Adult Treatment Panel (ATP II) have created an increasing demand for treatment with 3-hydroxy-3-methylglutayl coenzyme A (HMG-CoA) reductase inhibitors. Fluvastatin is the first completely synthetic agent in this class and offers a considerable price advantage over the other HMG-CoA therapies. In May 1994, the Buffalo Veterans Affairs Medical Center Lipid Clinic adopted a fluvastatin-preferred program in which all patients who were recommended for an HMG-CoA reductase inhibitor would be treated with fluvastatin as a first-line agent. Fluvastatin was started at 20 mg daily and titrated to goal. Patients who were stable with other HMG-CoA reductase inhibitors were converted to fluvastatin as just described. Preliminary analysis shows that, for new patients, 20 mg of fluvastatin daily at bedtime reduced low density lipoprotein cholesterol (LDL-C) by an average of 22% (range, 5–32%). Preliminary results for patients converted from another HMG-CoA reductase inhibitor showed that fluvastatin produced an additional LDL-C reduction of 18% (range, 5–10%). With a daily dose of 20 mg fluvastatin, patients with no heart disease (primary prevention) achieved ATP II goals in 60% of cases. For patients with established heart disease (secondary prevention), the goals of ATP II are lower but, despite this, 30% of patients taking fluvastatin at 20 mg daily achieved these goals. The patients in both groups who failed to achieve ATP II goals were titrated to a 40 mg daily dose, but the results of this titration are not yet available. Pharmacoeconomic outcomes were favorable. As more patients continue to be treated with fluvastatin as a primary HMG-CoA reductase inhibitor, per patient expenditures for this class of drugs have declined. More patients can be treated with an HMG-CoA reductase inhibitor with the same dollar expenditures. These preliminary results suggest that fluvastatin is an effective cholesterol-lowering agent. More satisfactory results were obtained with fluvastatin at 20 mg as monotheropy in a primary prevention population. Data with 40 mg doses or combination therapy are not yet available. Most important, the lower acquisition cost of fluvastatin offers an opportunity to treat more patients in a managed healthcare environment.
Evidence for a ∼ 4.5 aeon age of plagioclase clasts in a lunar highland breccia

Argon from neutron-irradiated mineral separates and whole rock samples of a metamorphosed breccia (65015) from Apollo 16 has been analysed with a large number of gas extraction steps in order to obtain a high resolution in the apparent ages and to identify the gas released from different sources. The results on plagioclase show a 40Ar–39Ar plateau age of 3.98 × 109 yr, which we attribute to the time of metamorphism, and an age of ∼ 4.5 × 109 yr in the high temperature fraction. Correlation of the release pattern with 37Ar instead of 39Ar permits the association of the ∼4.5 × 109 yr age with relict plagioclasts which were demonstrated in previous petrographic and Rb-Sr studies as being unequilibrated. This result suggests that it is possible to identify lithic components which represent the early lunar crust.
Children's lateral preference patterns: Frequency and relationships with achievement and intelligence☆

Abstract The frequencies of consistent, mixed, and inconsistent lateral preference patterns in 648 elementary school age children were examined. Preference was determined by 18 different hand, eye, and foot tasks. Almost 60% of the younger children and 35% of the older children demonstrated either mixed or inconsistent patterns. No differences were found in IQ, reading, arithmetic, or spelling achievement scores among the three groups of children, at any age or for either sex. Both the absence of any differences among the groups and the high frequency of mixed and inconsistent patterns in a normal population call into question the clinical utility of such patterns as either indices or correlates of learning difficulties.
Bailouts, Buy-Ins, and Ballyhoo

The bailout strategy now being pursued by Treasury under the recently authorized Troubled Asset Relief Plan, if "strategy" it can be called, remains obscure and erratic at best. All the while markets remain jittery and credit remains tight, as the underlying source of our present financial jitters—continued decline in the housing market and still mounting foreclosures—goes unaddressed. This piece proposes an interesting and novel approach to solving the financial problem. If it works out, it would eventually minimize the cost to the government.
Trial and Error Predicates and the Solution to a Problem of Mostowski

The purpose of this paper is to present two groups of results which have turned out to have a surprisingly close interconnection. The first two results (Theorems 1 and 2) were inspired by the following question: we know what sets are “decidable” — namely, the recursive sets (according to Church's Thesis). But what happens if we modify the notion of a decision procedure by (1) allowing the procedure to “change its mind” any finite number of times (in terms of Turing Machines: we visualize the machine as being given an integer (or an n-tuple of integers) as input. The machine then “prints out” a finite sequence of “yesses” and “nos”. The last “yes” or “no” is always to be the correct answer.); and (2) we give up the requirement that it be possible to tell (effectively) if the computation has terminated? I.e., if the machine has most recently printed “yes”, then we know that the integer put in as input must be in the set unless the machine is going to change its mind; but we have no procedure for telling whether the machine will change its mind or not.The sets for which there exist decision procedures in this widened sense are decidable by “empirical” means — for, if we always “posit” that the most recently generated answer is correct, we will make a finite number of mistakes, but we will eventually get the correct answer. (Note, however, that even if we have gotten to the correct answer (the end of the finite sequence) we are never sure that we have the correct answer.)
Calcium-Induced Changes to the Molecular Conformation and Aggregate Structure of β-Casein at the Air−Water Interface

The influence of calcium on interactions of β-casein at the air−water interface has been studied by several techniques, including interfacial rheology, atomic force microscopy (AFM), infrared reflectance−absorbance spectroscopy (IRRAS), and ζ potential measurements. In the absence of calcium, a weak interfacial gel forms after about 2.5 h. Also in the absence of calcium, the adsorbed β-casein film exhibits some degree of both intra- and intermolecular structural organization. For example, IRRAS spectra show a measurable amount of α-helix content, and AFM images indicate the presence of interfacial aggregates with a characteristic lateral length scale of 20−30 nm, which we interpret as hemimicelles. Upon the addition of calcium, particularly at Ca:β-casein molar ratios above ∼5:1, a stronger interfacial gel forms more quickly; for example, the interfacial shear moduli increase twice as rapidly. Also under these conditions (5:1 Ca:β-casein ratio) there is little evidence of structural organization; i.e., th...
Resonator/Oscillator response to liquid loading.

The resonant frequency of a thickness-shear mode resonator operated in contact with a fluid was measured with a network analyzer and with an oscillator circuit. The network analyzer measures changes in the device's intrinsic resonant frequency, which varies linearly with (ρη)1/2, where ρ and η are liquid density and viscosity, respectively. The resonator/oscillator combination, however, responds differently to liquid loading than the resonator alone. By applying the operating constraints of the oscillator to an equivalent-circuit model for the liquid-loaded resonator, the response of the resonator/oscillator pair can be determined. By properly tuning the resonator/oscillator pair, the dynamic range of the response can be extended and made more linear, closely tracking the response of the resonator alone. This allows the system to measure higher viscosity and higher density liquids with greater accuracy.
Hydrolysis and Solvent-Dependent 2′→5′ and 3′→5′ Acyl Migration in Prodrugs of 9-β-d-Arabinofuranosyladenine

As a prerequisite to quantitative in vivo studies to further explore the promising topical activity of the 2′,3′-di-O-acetyl derivative of 9-β-d-arabinofuranosyladenine (ara-A) against herpes virus infections, the kinetics of solution degradation of the 2′,3′-di-O-acetyl derivative and the 2′-, 3′-, and 5′-monoacetates were investigated. The rates of aqueous solution hydrolysis were found to be consistent with rank order predictions based on a consideration of substituent effects. Preliminary in vivo hydrolysis data, however, do not correlate with such predictions, indicating a need for more systematic studies of the effect of molecular structure on enzyme-catalyzed hydrolysis. An important reaction of the 2′,3′-diester and the 3′-monoester in aqueous solution, in addition to ester hydrolysis, is 3′→5′ acyl migration. 2′→5′ Acyl migration does not occur in water but is the predominant migration pathway in organic solvents, as verified by studies in acetonitrile. 1H NMR spectroscopy was employed to study the dependence of the conformation of the sugar ring on the solvent environment. Although a change in the equilibrium between the C(2′)endo and C(3′)endo conformational states does occur, it is not a dramatic change and cannot explain the solvent selectivity observed in the acyl migration kinetics.
The effects of student aid on recent college graduates

Using college graduates from the National Longitudinal Study of the High School Class of 1972 (N=3,136), this study reviews the relationships between student financial aid received during college and the types of activities pursued by students after graduating. Four areas of graduates' lives were examined: attending graduate school, choosing a job, forming a family, and forming personal values. Three types of student aid were included: loans, grants, and work, with emphasis on loans. Despite the expectation of a negative impact of loans, the results showed no support for this, and in general, the findings suggested that college graduates who received aid as undergraduates were little different from other graduates. The major implication is that the self-help forms of aid (loans and work) are not detrimental to the future plans of recipients.
Headache Plus: Trigeminal and Autonomic Features in a Case of Cervicogenic Headache Responsive to Third Occipital Nerve Radiofrequency Ablation

Objective To describe a case of cervicogenic headache with associated autonomic features and pain in a trigeminal distribution, all of which responded to third occipital nerve radiofrequency ablation. Design Single case report. Setting Massachusetts General Hospital Center for Pain Medicine. Patients A 38-year-old woman with history of migraines and motor vehicle accident. Interventions Right third occipital nerve diagnostic blocks and radiofrequency lesioning. Outcome Measures Pain reduction; physical findings, including periorbital and mandibular facial swelling, tearing, conjunctival injection, and allodynia; and use of opioid and non-opioid pain medicines. Results The patient had complete relief of her pain and autonomic symptoms, and was able to stop all pain medications following a dedicated third occipital nerve lesioning. Conclusions This case illustrates the diagnostic and therapeutic complexity of cervicogenic headache and the overlap with other headache types, including trigeminal autonomic cephalgias and migraine. It represents a unique proof of principle in that not only trigeminal nerve pain but also presumed neurogenic inflammation can be relieved by blockade of cervical nociceptive inputs. Further investigation into shared mechanisms of headache pathogenesis is warranted.
Process monitoring techniques using acoustic waves

The authors outline the limitations of current film thickness technology and propose two novel methods for nondestructive, in-situ film thickness process monitoring: acoustic time domain reflectometry (TDR) and acoustic reflection coefficient phase measurements. Theoretical calculations and experimental measurements of different metal films are used to demonstrate the viability of these techniques. An experimental system has been built and preliminary results on gold films show promise for using acoustic TDR as a postdeposition process monitor. An experimental system based on acoustic reflection coefficient phase measurements has been built and shows good preliminary results in gold and aluminum films. >