cssi/SciSciGPT-SciSciNet huggingface dataset:
Rare earth element concentrations and speciation in organic-rich blackwaters of the Great Dismal Swamp, Virginia, USA

Concentrations of rare earth elements (REE), major inorganic solutes, and dissolved organic carbon (DOC) were measured in waters from the Great Dismal Swamp in southeastern Virginia, including Lake Drummond (pH=4.3), and its principal surface inflows and outflow. Concentrations of REE are high in the lake (average Nd=8 nmol/kg), and the acidic DOC-rich inflow and out flow waters (i.e., Nd=12.5 nmol/kg in Jericho–Washington Ditch and ∼8 nmol/kg in Feeder Ditch, respectively). The slightly acidic (pH 6–6.4) inflow waters from west of the Suffolk Scarp that comprise the chief source of surface water flow into Lake Drummond exhibit lower REE concentrations (Nd=3.4–7 nmol/kg). Great Dismal Swamp waters are all enriched in the middle REEs compared to the light and heavy REEs (LREE and HREE) when normalized to upper continental crustal (UCC) values. Rare earths are positively correlated to DOC concentrations in Great Dismal Swamp waters and inversely correlated with pH. Speciation calculations using a modified version of the well established Humic Ion-Binding Model V predict that organic matter complexes are the predominant form of dissolved REEs in Great Dismal Swamp waters despite significant competition from aqueous Fe and Al for organic matter binding sites. Adsorptive cathodic stripping voltammetry (ACSV) was employed, using a previously developed competitive ligand equilibration approach that involved adding the o-cresolphthalexon (OCP) ligand, to directly investigate REE complexation with natural organic ligands in Great Dismal Swamp waters. Although preliminary, the results of the ACS voltammetric titrations are consistent with dominance of organic matter complexes of REEs in Great Dismal Swamp waters. The results of the speciation modeling and the voltammetric titrations all point towards control of dissolved REEs in Great Dismal Swamp waters by complexation of these heavy metals with natural organic matter.
Case Records of the Massachusetts General Hospital--a home-court advantage?

In 1924 the Journal began the weekly publication of the Case Records of the Massachusetts General Hospital (MGH), with Richard C. Cabot, M.D., as editor. Since then, the clinicopathological confere...
A replacement schedule for multicomponent life‐limited parts

In previous papers [1], [2] the authors developed a maintenance policy for a single life-limited part. Using an opportunistic replacement approach a scheme was devised which utilized early replacement of equipment to offset more costly future expenditures. This paper will extend the results to the multicomponent case. Examples are given illustrating the benefits of this new technique.
Heat transfer from a flat surface to an oblique impinging jet

Experiments are conducted to determine the heat transfer to a jet impinging at different oblique angles to a plane surface. The main portion of the test plate contains a composite sheet of temperature-sensitive liquid crystal, which is sandwiched between a thin metallic-foil heater and a specially designed liquid bath. The results indicate a displacement of the peak heat transfer from the geometric center of the jet origin, the displacement being a function primarily of impingement angle. Contours of constant heat transfer coefficient are obtained and correlated with an empirical equation that permits determination of average Nusselt numbers over areas of interest.
Defining sustainability metric targets in an institutional setting

Purpose – The purpose of this paper is to expand on the development of university and college sustainability metrics by implementing an adaptable metric target strategy.Design/methodology/approach – A combined qualitative and quantitative methodology is derived that both defines what a sustainable metric target might be and describes the path a university might take to get there. Local to global spatial scales and short to long‐term time scales are accounted for. Four popular metrics are developed: carbon emissions, water use, recycling rate, and energy use. Sustainability metric data available from Yale University are utilized to show the applicability of this metric target strategy.Findings – Targets for sustainability metrics may be set at short, medium, and long‐term time scales. While quantitative targets may be set for sustainability metrics, these are often long‐term ideals that offer no information on the path to achieve them. If a path to achieving these targets is outlined, it is often arbitrary...
Naloxone blocks transferred preconditioning in isolated rabbit hearts.

We have shown that the cardioprotective benefits of ischemic preconditioning (PC) can be transferred from PC to virgin acceptor hearts via coronary effluent transfusion, implicating the presence of hormonal preconditioning factor(s). Using isolated buffer-perfused rabbit hearts, our aims were to: (1) determine whether the protective factor(s) could be concentrated and recovered by reverse phase chromatography and (2) whether opioid receptor activation contributes to this transferred cardioprotection. Material released into the coronary effluent during PC ischemia/reperfusion or normoxic perfusion was concentrated by reverse phase chromatography. In phase one, hearts received no intervention (controls), PC ischemia, concentrate generated from normoxic hearts (normoxic acceptors) or concentrate from PC hearts (PC acceptors). All hearts underwent 40 min of global ischemia, and area of necrosis (AN) was delineated by tetrazolium staining. In phase two, three additional groups of hearts (control, PC and PC acceptors) received the opioid antagonist naloxone (2 microM) throughout the intervention phase. Treatment with normoxic concentrate had no effect on infarct size: (AN: normoxic acceptors 39+/-8%; control 42+/-8%). In contrast, treatment with PC concentrate evoked cardioprotection equivalent to that afforded by conventional PC (AN 19+/-5% and 21+/-6% respectively P<0.05 v control). Naloxone had no effect on infarct size in controls, and did not inhibit preconditioning. However, naloxone abrogated the protection achieved by transfer of PC concentrate (AN: 44+/-7%). These results indicate that PC concentrate evokes a cardioprotective effect via a mechanism requiring an intact opioid receptor system.
Ethical dimensions of fetal neurology

Ethics is an essential dimension of the management of counseling a pregnant woman when a neurologic anomaly is diagnosed. This paper provides an overview of obstetric ethics, with a central focus on the ethical concept of the fetus as a patient. On this basis, the authors analyze the ethical and clinical dimensions of the obstetric management options for pregnancies complicated by a neurologic anomaly. These management options include aggressive management, induced abortion, termination of pregnancy during the third trimester, non-aggressive obstetric management, and cephalocentesis.
Bi-criterion single-machine scheduling with forbidden early shipments

Abstract Past research on the multiobjective single-machine scheduling problem has focused primarily on performance measures involving flowtime, maximum tardiness, or total tardiness. Jobs that are completed early are assumed to incur no penalty. When early shipments are forbidden, jobs completed early have to be stored, thereby incurring holding costs. This paper presents a mixed-integer programming model of the bicriterion single machine scheduling problem where early shipments are forbidden. The objective function is a combination of total tardiness and earliness. Some computational experience is discussed.
Difficulties in finding modes experimentally when several contribute to a resonance

For situations in which several modes may be contributing to a single resonance of a structure, a method for detecting the individual modes and for extracting useful information from the measurments is given. It is also shown that non-crossing of the experimental nodal curves may occur when modal resonant responses overlap because of finite damping, and again a method is presented that allows the extraction of useful results from measurements.
Characterization of phospholipase A2 activity in serum of the American alligator (Alligator mississippiensis)

PLA2 is a diverse class of enzymes with a broad spectrum of physiological functions. Secretory PLA2 isoforms have been reported to exhibit important innate immune function in higher vertebrates. This study was conducted to characterize PLA2 activity in the serum of the American alligator (Alligator mississippiensis). We used a glycerophospholipid with a fatty acid in the sn-2 position labeled with a fluorescent probe (BODIPY) to detect and quantify alligator serum PLA2 activity. Incubation of BODIPY-labeled bacteria with different concentrations of alligator serum resulted in a concentration-dependent detection of PLA2 activity. Kinetic studies showed that product formation was rapid, with substantial activity within 5 min, and maximal activity at approximately 20 min. The alligator PLA2 activity was temperature-dependent, with activity at lower temperatures (5−10°C) approximately half of that observed at temperatures of 30–40°C. In addition, the generation of fluorescent product was reduced by a specific inhibitor (p-bromophenacyl bromide) of secretory PLA2 in a concentration-dependent manner, enforcing the idea that the observed activities are due to a secretory PLA2 enzyme in alligator serum. J. Exp. Zool. 311A: 662–666, 2009. © 2009 Wiley-Liss, Inc.
The action of ribonuclease on fixed tissues.

To study the optimal conditions for histochemical use of ribonuclease on fixed tissues, the factors of (1) type of fixation, (2) temperature, pH, type of buffer and length of incubation, (3) concentration of enzyme, and (4) staining and dehydration of sections were observed on rabbit pancreas.The fixing fluids studied were sublimate-alcohol, Bouin's, Zenker-acetic, Zenker-formol, Petrunkevich's cupric-paranitrophenol, 10% neutral formalin, SUSA, Carnoy, Bensley's chrom-sublimate, absolute ethyl alcohol and acetone. Formaldehyde was a satisfactory fixative, although others might be preferred for special purposes. Of the five buffers tested, McIlvaine's citric-acid-disodium-phosphate mixture was the most satisfactory, whereas veronal-acetate extracted considerable stainable cytoplasmic material. The optimum concentration of ribonuclease and length of incubation varied greatly after the 11 different types of fixation. For example, with ribonuclease buffered by Mcllvaine's fluid, the intense cytoplasmic stain...
Seismic stratigraphic correlation across the New England Seamounts, western North Atlantic Ocean

Correlation in the western North Atlantic Basin of deep-water seismic stratigraphy across a basement high within the New England Seamounts shows that the seismic sequence of the Nova Scotian rise is broadly similar to that off the United States. Time of seamount volcanism inferred from stratigraphic relations around the basement high is consistent with a hot-spot origin, but nearby stratigraphic data indicate that earlier and later eruptions occurred, suggesting lithospheric weakness that predisposed this area to volcanism. Patterns of Tertiary abyssal current erosion and sediment deposition were controlled by sea-floor morphology around the seamounts and interaction of abyssal currents with the Gulf Stream.
Chemical differences between antibody fragments as shown by paired label studies.

PORTER1has shown that antibodies can be digested with papain to yield univalent fragments, molecular weight about 50,000, and an inactive fragment, molecular weight 80,000. The univalent fragments obtained are separable by chromatography on carboxymethylcellulose (CMC) into two fractions called Fraction I and Fraction II. Since then, Stelos et al.2have shown that the fragments in each fraction come from different antibody molecules (see also Palmer et al.3). We have also been able to show that fragments of Fraction I and fragments of Fraction II can be further fractionated and that the fragments in the various fractions appear to be different on a chemical basis also2. We showed that in the case of specifically purified antibody against the azobenzoate ion and azobenzenearsonate ion the rates of iodination of the fragments appearing in Fraction I are different from those appearing in Fraction II. This was demonstrated by iodinating the mixture of fragments and then chromatographing it. It was found that the iodine–protein ratio was different for the two fractions. On the other hand, the rates of iodination of the fragments of Fraction I and of Fraction II from normal γ-globulin were usually quite similar. The results of this experiment indicate that not only were there chemical differences between the fragments in Fraction I and in Fraction II from a specifically purified antibody, but also that these molecules differed from normal γ-globulin.
Bidirectional Control of Quantal Size by Synaptic Activity in the Hippocampus

Analysis of strontium-induced asynchronous release of quanta from stimulated synapses revealed that long-term potentiation and long-term depression in the CA1 region of the mammalian hippocampus are associated with an increase and a decrease, respectively, in quantal size. At a single set of synapses, the increase in quantal size seen with long-term potentiation was completely reversed by depotentiating stimuli. Long-term potentiation and depression are also associated with an increase and decrease, respectively, in the frequency of quantal events, consistent with an all-or-none regulation (up or down) of clusters of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptors, a change in the release of transmitter, or both.
Clay Vessels at 35CS43 on the Oregon Coast

This article describes and analyzes two large unfired, non-portable clay vessels found at site 35CS43, at the mouth of the Coquille River on the Oregon coast, in levels estimated to be 1500–2000 B.P. These vessels are unique but share some features with other clay artifacts in the Northwest. Origin and production, use and breakdown, burial, and antiquity of these artifacts are discussed.
DUTCH GENRE PAINTING AS RELIGIOUS ART: GABRIEL METSU'S ROMAN CATHOLIC IMAGERY

Gabriel Metsu's reputation rests on his popular genre imagery; however, the Dutch artist also produced religious paintings with Roman Catholic symbolism. Archival documents, personal and professional relationships, and a small number of paintings confirm a close engagement with the Dutch Roman Catholic community from his youth in Leiden to his maturity in Amsterdam. Metsu's connections with Roman Catholic painters, poets, and priests in the Netherlands provided the cultural context for his religious art. Moreover, contemporary devotional publications and reproductive engravings after Italian art established iconographic and compositional solutions evident in Metsu's traditional religious scenes and in his genre imagery.
Statistical mechanical theory of the effect of added nonelectrolytes on the conductances of electrolytes

When a neutral nonelectrolyte is added to an electrolytic solution, the electrical conductance of the electrolytic solution is usually reduced. Attempts to correlate this effect with changes in the bulk properties of the solvent have been unsuccessful. The purpose of this paper is to account for this effect (for dilute solutions) in terms of a statistical mechanical theory which takes into account the specific interactions between molecules of the nonelectrolyte and ions of the electrolyte. A simple continuum model is used to represent the solution containing nonelectrolyte molecules and electrolyte ions placed in a constant, homogeneous electric field. With an approximate theory valid at infinite dilution, an equation describing the variation of the limiting equivalent conductance of the electrolyte with the concentration of an ideal dipolar nonelectrolyte is obtained. Comparisons with experiments are made.
The heating duration and provenance age of rocks in the Salton Sea geothermal field, southern California

Abstract 40Ar/39Ar step heating of single K-feldspar crystals (∼ 500 μg) in a furnace with a low argon blank and accurate temperature control provide constraints on the thermal history of the Salton Sea geothermal field, southern California. Estimates of 40Ar loss from detrital K-feldspars, coupled with kinetic information gleaned from laboratory degassing of 39Ar, allow possible thermal histories to be evaluated. Samples from core and cuttings of sandstones from the State 2–14, Landers #1, Dearborn Farms #1, Magmamax #2, Elmore #3 and Sinclair #3 wells have been analyzed for this purpose. No recent 40Ar∗ loss is recognized in any of the 17 crystals measured, even for samples currently at temperatures greater than 275°C. This observation suggests that the present temperature distributions in these wells have not been maintained for greater than 1000 years. However, aggregates (∼ 100 mg) of two K-feldspar samples do reveal recent 40Ar∗ loss from the State 2–14 well, suggesting a time scale of 1000 to 5000 years for near-peak thermal conditions. These estimates of heating duration are broadly consistent with earlier results from thermal modelling, but do not support interpretations that paleotemperatures were once hotter than present. Provenance ages span the Tertiary through Middle Proterozoic but cluster at ages of 25, 70 and 1250 Ma. These age peaks are very common K-feldspar K-Ar ages in detachment terranes of southeastern California and southwestern Arizona, both drained by the Colorado River. This coincidence supports earlier suggestions that the sands of the Salton Trough were derived mainly from the Colorado River. Unrealistically low apparent activation energies (
Endogenous gibberellins and inhibitors in relation to flower induction and inflorescence development in the olive.

Comparative analyses of reproductive and vegetative tissues of the olive (Olea europaea L. cv. Manzanillo) for endogenous hormones, particularly inhibitors and gibberellin like substances, were made to study the relation between such hormones and thermoinduction of flowering. Qualitative and quantitative changes in gibberellin-like subtance(s) were observed in lateral buds (potential flower buds) but not in leaves or terminal buds (potential vegetative buds) sampled from orchard trees at intervals during the winter and spring. At least two types of gibberellin-like substances were found in extracts of lateral buds; their levels increased progressively during the low temperature induction period, reaching a maximum shortly before floral initiation. Two types of inhibitors were extracted from buds and leaves. A nonacidic type did not change during the induction stage but decreased considerably during the initiation period. An acidic inhibitor, which was identified as an abscisic acid-like substance, was present at a relatively lower level in lateral (flower) buds than in terminal (vegetative) buds during the induction period.It was concluded that winter chilling induces flowering in the olive possibly by altering a balance between endogenous gibberellins and inhibitors, including abscisic acid.Inflorescence development following the winter chilling period was associated with an increase in the level of endogenous inhibitors and gibberellins. Shoot growth, however, was correlated with a decrease in the inhibitor(s) level. A rise in gibberellin-like activity is believed to be a result, not a cause, of shoot growth.
Skeletal muscle capillary geometry: adaptation to chronic hypoxia

The potential for gas and metabolite exchange across the capillary bed is determined largely by the capillary length and surface area available for blood-tissue transfer. It has been suggested that chronic exposure to hypoxia increases capillary tortuosity; however, the degree of orientation of capillaries in muscles of sea level animals chronically exposed to hypoxia has never been quantified rigorously. An augmented capillary tortuosity would increase capillary length per volume of muscle fiber, Jv(c,f), irrespective of whether new capillaries are formed. To resolve this issue, female rats (278 +/- 5 g) were maintained for 5 months in a temperate environment at 3800 m (PIO2 = 91 Torr). Capillary tortuosity and Jv(c,f) were estimated from transverse and longitudinal sections in perfusion-fixed M. Soleus and M. Gastrocnemius. Values were compared with weight-matched controls (274 +/- 7 g). Neither capillary density (normalized to sarcomere length 2.1 microns, hypoxic = 1292 +/- 79, control = 1282 +/- 43 mm-2) nor capillary-to-fiber ratio (hypoxic = 2.50 +/- 0.15, control = 2.57 +/- 0.05) were changed after altitude exposure. Capillary tortuosity was a function of sarcomere length in all animals and this relationship was not changed by hypoxia. Capillary length per volume of muscle fiber was unchanged (hypoxic = 1541 +/- 72, control = 1531 +/- 44 mm-2) as was mean capillary diameter. We conclude that chronic exposure to 3800 m does not change capillary tortuosity or surface area in rat M. Soleus or M. Gastrocnemius.
Clinical Approach to Acute Cough

Acute cough is among the most common symptoms for which patients seek medical attention. It accounts for millions of days lost from school and work and billions of dollars spent on medical care. Acute cough is defined as cough present for 3 weeks or less. It most often is caused by a viral infection of the upper respiratory tract (“common cold”) or lower respiratory tract (i.e., “acute bronchitis”). The most effective treatment for cough due to the common cold is a combination first-generation antihistamine plus decongestant. Antibiotics are not indicated for most cases of acute cough. Occasionally, acute cough can be a symptom of a life-threatening condition.
System Justification in Responding to the Poor and Displaced in the Aftermath of Hurricane Katrina

We examine people's reactions to the victims of Hurricane Katrina, most of whom are minorities living in poverty, and we do so in terms of system justification theory. We propose that the social system was indirectly threatened for the public when inadequate relief efforts exposed governmental shortcomings, called into question the legitimacy of agency leadership, and highlighted racial inequality in America. In response to such system threats, both victims and observers (e.g., the general public, commentators, policy makers) are known to engage in various forms of system justification, including direct defense of the status quo, victim blaming, stereotyping, and internalization of inequality. These processes can reduce emotional distress and restore perceived legitimacy to the system, but they may have a number of troubling consequences for the storm victims in their efforts to return to normalcy.
Effect of a benzodiazepine (Alprazolam) on plasma epinephrine and norepinephrine levels during exercise stress

To determine whether a benzodiazepine central nervous system depressant, alprazolam, inhibits sympathetic discharge during exercise stress, 11 healthy men, aged 21 to 35 years, performed symptom-limited treadmill tests before and on the third day of drug therapy (0.5 mg 3 times daily). Plasma epinephrine and norepinephrine levels were measured at rest and at 8 minutes, 11 minutes and maximal exercise. Owing to catheter malfunction during vigorous exercise, paired samples could be obtained from only 8 subjects at 8 minutes and from only 4 subjects at 11 minutes of exercise. During drug treatment, the plasma epinephrine level was lower at rest (30 +/- 4 vs 53 +/- 7 pg/ml, p less than 0.01), and at 8 minutes (60 +/- 13 vs 117 +/- 19 pg/ml, p less than 0.01), 11 minutes (120 +/- 39 vs 193 +/- 52 pg/ml, p less than 0.05), and maximal exercise (520 +/- 125 vs 970 +/- 324 pg/ml, p = 0.13). Plasma norepinephrine was unchanged at rest (452 +/- 57 vs 413 +/- 45 pg/ml) but lower at 8 minutes (730 +/- 75 vs 886 +/- 82 pg/ml, p less than 0.01), 11 minutes (1,077 +/- 197 vs 1,447 +/- 301 pg/ml, p less than 0.05) and at maximal exercise (3,453 +/- 487 vs 5,590 +/- 1,100 pg/ml, p = 0.09). Exercise duration (17 +/- 1 and 17 +/- 1 minutes) was unchanged on drug. Thus, alprazolam reduces the plasma catecholamine response to exercise stress, possibly by inhibiting centrally mediated sympathetic discharge. Blunting of sympathetic activation may be beneficial in cardiac disorders in which increased sympathetic tone is potentially deleterious.
Automated group desensitization for test anxiety.

Abstract The present study was an attempt to develop an automated (i.e. preprogrammed and mechanically administered) group desensitization treatment for test anxiety: to evaluate the effectiveness of the treatment of systematic desensitization without counseling; and to determine the importance of the physical presence or absence of the therapist in the sessions. Forty-two test-anxious female college students were divided into three matched groups on the basis of previous semesters' grade point average (G.P.A. ). The three groups consisted of a Waiting List control and two treatment groups; in one group, desensitization was administered by a therapist, whereas in the other, by a tape recorded set of instructions. Both treatment groups manifested a significant improvement in the G.P.A. following treatment, when compared with the control group. In addition, self-report measures indicated that following final exams there was a significant reduction of daily anxiety for treatment groups as compared to the controls. No significant differences were found when the two treatments were compared with each other; however, a strong trend favoring the Therapist-Present group was noted for improved G.P.A.
Mathematical and numerical analysis of a differential equation model for a gas glow discharge

Abstract A nonlinear characteristic value problem modeling a gas glow discharge is considered. A small parameter solution is found which corresponds to the classical Schottky equilibrium approximation. The operating characteristic is computed using the small parameter solution as a starting point. Uniqueness of the operating characteristic is inferred from a combination of global mathematical analysis and numerical analysis. The operating characteristic is stable. Finally, an observation on constriction is made.
Brouwer's fixed point theorem (abstract only)

"Brouwer's Fixed Point Theorem" was named after the Dutch mathematician "L. E. J. Brouwer". This theorem states that for every continuous function "f" mapped onto itself at a given interval, has at least one fixed point such that "f(x0) = x0". The proof of this theorem uses what is called "Sperner's Lemma" (by Emanuel Sperner), which would be the one focused on inorder to help understand "Brouwer's Fixed Point Theorem".
Focusing of laser-accelerated protons for fast ignition studies

Proton focusing following the interaction of a short (tp&#60;1 ps), ultra-intense (IL>1018Wcm−2) laser pulse with curved surfaces has been reported [1]. However a thorough understanding of proton focusing in terms of focal position and achievable focal spot size is essential for applications such as isochoric heating, fast ignition and medical applications.
Topological and non-topological solitons of the Klein–Gordon equations in 1+2 dimensions

This paper obtains the topological and non-topological 1-soliton solution of the Klein–Gordon equation in 1+2 dimensions. There are five various forms of this equation that will be studied. The solitary wave ansatz will be used to carry out the integration.
A circuit model of hair-cell transduction for temporal processing and auditory feature extraction

We present a novel low-power circuit for level crossing interval measurements on continuous-time auditory signals, as obtained from the outputs of an analog cochlear filter bank. The circuit achieves immediate response for a given signal in the audio frequency range. Experimental results from a fabricated array of 9 level crossing transducers demonstrate frequency-to-voltage conversion over a range covering the audio band, with less than 120 /spl mu/W of power dissipated per cell from a 5 V supply.
Effects of Sildenafil on Ventricular and Vascular Function in Heart Failure With Preserved Ejection Fraction

Background—Early studies showed beneficial effects of phosphodiesterase 5 inhibitors on cardiovascular function in heart failure (HF) patients, but the RELAX trial observed no improvement in exercise capacity with sildenafil treatment in subjects with HF and preserved ejection fraction. Methods and Results—A subgroup of participants in the RELAX trial (n=48) underwent comprehensive noninvasive cardiovascular assessment before and after treatment with sildenafil or placebo in a prospective ancillary study. Left ventricular contractility was assessed by peak power index and stroke work index. Systemic arterial load was assessed by arterial elastance (Ea) and right ventricular afterload by pulmonary artery systolic pressure. Endothelial function was assessed by reactive hyperemia index after upper arm cuff occlusion. Compared with placebo (n=25), sildenafil (n=23) decreased Ea (−0.29±0.28 mm Hg/mL versus +0.02±0.29, P=0.008) and tended to improve reactive hyperemia index (+0.30±0.45 versus −0.17±0.30, P=0.05...
Soluble precipitable porphyrins for use in targeted molecular brachytherapy

In a new therapy that aims to concentrate and immobilize therapeutic radionuclides in nanoscale assemblies within solid tumors, a soluble precipitable reagent (SPR) is administered as the radionuclide carrier and is converted to non-diffusible precipitate by an enzyme located in tumor tissues. To meet the objective of such an SPR, we have prepared and examined a class of porphyrin–alkyldiphosphates that are soluble in aqueous solution and that are rendered insoluble upon removal of the two phosphate groups. The porphyrins examined herein are of the trans-AB architecture wherein the substituents are a bis(dihydroxyphosphoryloxy)alkyl group and a phenyl (or p-bromophenyl) group. Provisions for later incorporation of radionuclides have been established by preparation of the analogous copper chelate or the meso-iodo free-base porphyrin. Altogether, four porphyrins bearing a bis(dihydroxyphosphoryloxy)alkyl group were examined and found to exhibit satisfactory solubility in water (>1 mM). Dephosphorylation reactions have been carried out in vitro using the enzyme shrimp alkaline phosphatase. In each case, enzyme-induced precipitation was observed. The soluble-to-insoluble conversion has been examined by visual inspection, absorption spectroscopy, electrospray ionization mass spectrometry, and nephelometry using non-radiolabeled porphyrins.
A practical method for reliability analysis of phased-mission systems

Many practical systems are phased-mission systems where the mission consists of multiple, consecutive, non-overlapping phases. For the mission to be a success, the system must operate successfully during each of the phases. In each phase, the system has to accomplish a specific task and may be subject to different stresses. Thus, the system configuration, success criteria, and component failure behavior may change from phase to phase. An accurate reliability analysis of these systems must consider the statistical dependencies of component states across the phases. The consideration of these dynamic dependencies poses unique challenges to existing reliability analysis methods. In this paper, we propose an efficient method for exact reliability evaluation of a special class of phased-mission systems containing multiple subsystems where all components within a subsystem are identical. The configuration of each subsystem can change with the phases, including their active and inactive status, redundancy type, and minimum required working components. If any one of the required (active) subsystems is failed in a phase, the system is considered to be failed in that phase. We also consider the time-varying and phase-dependent failure rates and associated cumulative damage effects. From the published examples, it can be shown that the mild restrictions imposed on the system configuration are applicable for a wide range of practical systems. The proposed method, which can be applied to very large-scale systems, is based on conditional probabilities and an efficient recursive formula to compute these probabilities. The main advantage of this method is that both the computational time and memory requirements of the method are linear in terms of the system size. We demonstrate the efficiency of the proposed method using medium-scale to large-scale systems. The proposed method provides a simple, efficient, and accurate reliability analysis of practical and large-scale phased-mission systems.
Exact voxel occupancy with graph cuts

Voxel occupancy is one approach for reconstructing the 3-dimensional shape of an object from multiple views. In voxel occupancy, the task is to produce a binary labeling of a set of voxels, that determines which voxels are filled and which are empty. In this paper, we give an energy minimization formulation of the voxel occupancy problem. The global minimum of this energy can be rapidly computed with a single graph cut, using a result due to D. Greig et al. (1989). The energy function we minimize contains a data term and a smoothness term. The data term is a sum over the individual voxels, where the penalty for a voxel is based on the observed intensities of the pixels that intersect it. The smoothness term is the number of empty voxels adjacent to filled ones. Our formulation can be viewed as a generalization of silhouette intersection, with two advantages: we do not compute silhouettes, which are a major source of errors; and we can naturally incorporate spatial smoothness. We give experimental results showing reconstructions from both real and synthetic imagery. Reconstruction using this smoothed energy function is not much more time consuming than simple silhouette intersection; it takes about 10 seconds to reconstruct a one million voxel volume.
The Codevelopment of Skill at and Preference for Use of Retrieval-Based Processes for Solving Addition Problems: Individual and Sex Differences from First to Sixth Grades.

The ability to retrieve basic arithmetic facts from long-term memory contributes to individual and perhaps sex differences in mathematics achievement. The current study tracked the codevelopment of preference for using retrieval over other strategies to solve single-digit addition problems, independent of accuracy, and skilled use of retrieval (i.e., accuracy and reaction time [RT]) from first to sixth grades inclusive (N = 311). Accurate retrieval in first grade was related to working memory capacity and intelligence, and it predicted a preference for retrieval in second grade. In later grades, the relation between skill and preference changed such that preference in one grade predicted accuracy and RT in the next grade as RT and accuracy continued to predict future gains in preference. In comparison with girls, boys had a consistent preference for retrieval over other strategies and had faster retrieval speeds, but the sex difference in retrieval accuracy varied across grades. Results indicate that ability influences early skilled retrieval, but both practice and skill influence each other in a feedback loop later in development and provide insights into the source of the sex difference in problem-solving approaches.
Differential Reflectivity Measurements in Rain: First Experiments

Results of the first measurements of differential reflectivity (ZDR) in rain are reported. ZDR = 10 log (ZH/ZV) dB involves copolar measurements of ZH and ZV, the radar reflectivity factors at horizontal and vertical polarizations, respectively. The data were obtained with the University of Chicago-Illinois State Water Survey (CHILL) radar facility in Oklahoma during Spring 1977 and confirmed theoretical expectations that ZDR should be positive, ranging between around 0-4 dB. By combining ZDR measurements with ZH, it is shown how estimates of N0 and D0, the parameters of an exponential raindrop size distribution, can be obtained. These estimates were subsequently used to compute rainfall rates as a function of range along a radar ray. These results illustrate that ZDR can have important applications in the quantitative, remote measurement of drop-size distributions and rainfall.
The physiology of pigmentation.

Abstract 1. 1. The mature pigment-producing cell, the melanocyte, is derived from a short-lived embryonic structure, the neural crest. 2. 2. Valuable information on the inheritance of pigmentation has been derived from mice, fowl, fishes, and the fruit fly, Drosophila. A given gene affects a given aspect of the pigmentation process. 3. 3. Melanin is formed by the oxidation of tyrosine to 3,4-dihydroxyphenylalanine (dopa). Tyrosinase, a copper protein enzyme, acts as a catalyst in this reaction. Molecular oxygen must be present for this reaction to take place. Lack of any one of these substances prevents melanin formation. 4. 4. Advances in knowledge of the physiology and biochemistry of this basic reaction and the chemical and physical factors influencing it have made possible newer therapeutic methods of inhibiting or accelerating pigmentation. 5. 5. The most effective drug for producing pigmentation is 8-methoxy-psoralen, and for depigmentation is monobenzylether of hydroquinone.
Methods of Feedback Control for Adaptive Counter-Phase Optical Interference Cancellation

We describe two methods of automatically tuning the optical parameters of the optical counter-phase interference-cancellation system. The methods not only achieve signal cancellation automatically but also permit that cancellation to be maintained in the presence of dynamic amplitude and phase fluctuations in the input signal. The purpose of this paper is twofold: First, we show that this conceptually simple optical method of interference cancellation readily lends itself to a simple method of closed-loop control and second, we introduce a novel method of optical closed-loop control. This work has allowed for fully adaptive operation of the opto-cancellation system in proof-of-principle laboratory experiments while also exposing issues to be addressed so that adaptive operation may be realized in more realistic situations.
Heat dissipation bounds for nanocomputing: Theory and application to QCA

Computing circuits that implement logically irreversible operations unavoidably dissipate heat. The resulting dissipative costs, while insignificant in CMOS technology, may be dominant or even prohibitive in some dense, high speed post-CMOS nanocomputing approaches. This motivates determination of lower bounds on the dissipative cost of computation that can be applied to concrete nanocomputing technology proposals. In this work, we outline a general approach for the determination of such bounds and illustrate its application to a half adder circuit implemented in quantum cellular automata (QCA) controlled using both Landauer and Bennett clocking schemes that support pipelining. The resulting bounds on energy dissipation are used to compare lower bounds on power dissipation for the two clocking schemes at a fixed computational throughput. Potential application of our approach to assessment of post-CMOS nanocomputing technologies, both transistor-based and non-transistor based, is briefly discussed.
Robustness testing of the Microsoft Win32 API

Although Microsoft Windows is being deployed in mission-critical applications, little quantitative data has been published about its robustness. We present the results of executing over two million Ballista-generated exception handling tests across 237 functions and system calls involving six Windows variants, as well as similar tests conducted on the Linux operating system. Windows 95, Windows 98 and Windows CE were found to be vulnerable to complete system crashes caused by very simple C programs for several different functions. No system crashes were observed on Windows NT, Windows 2000 or Linux. Linux was significantly more graceful at handling exceptions from system calls in a program-recoverable manner than Windows NT and Windows 2000, but those Windows variants were more robust than Linux (with glibc) at handling C library exceptions. While the choice of operating systems cannot be made solely on the basis of one set of tests, it is hoped that such results will form a starting point for comparing dependability across heterogeneous platforms.
Survey of cognitive radio architectures

Cognitive Radio and Cognitive Networking are emerging fields of research that has the potential for transformative changes to the current status quo. Cognitive systems utilize environmental observations such as spectrum or network conditions to change operational configurations in order to optimize performance at individual node or over end-to-end goals. This paper surveys some of these origin cognitive frameworks and correlates these frameworks to cognitive radio implementations of today. Several definitive implementations and cognitive radio architectures are reviewed and compared. This paper also identifies area of need and suggests directions forward for novel research in this area through interdisciplinary collaboration with the cognitive sciences, integrating prediction and proactive operation into cognitive radio/network architectures and identifying less researched artificial intelligence algorithms that show promise towards cognitive radio architecture.
Contract choice in agriculture with joint moral hazard in effort and risk

We analyze optimal contract choice in agriculture when there is joint moral hazard on the part of the farmer in the supply of effort and the riskiness of the technique of cultivation. In the presence of limited liability, high-powered incentive contracts such as fixed rental contracts will induce the farmer to adopt techniques of cultivation that are too risky from the point of view of the landlord. On the other hand, low-powered incentive contracts such as fixed wage contracts will induce the farmer to supply too little effort. We show that sharecropping contracts emerge as a natural solution to balance these two conflicting considerations.
Crisis-care in critical incident debriefing

Critical incidents are recognized disasters, individually significant events involving death or serious injury and necessitating rescue or emergency care; or other crisis situations that energize u...
Car Seat–Associated Hypoxia: Low Birth Weight Term Newborns, Another Group at Risk

* Abbreviation: AAP — : American Academy of Pediatrics Oxygen desaturation of premature newborns in car seats was first reported by Willet1 in 1986. In response to that study, the American Academy of Pediatrics (AAP) recommended in 1991 that infants <37 weeks’ gestation be monitored for oxygen desaturation and bradycardia in their car seat before discharge.2 The most recent AAP statement on this issue identifies other infants who are ≥37 weeks and who may be at risk for this problem as potential candidates for car seat testing.3 Although term low birth weight newborns are not specifically mentioned in that statement, they would be logical candidates for inclusion given the presumed mechanism of desaturation in these devices (physical-mechanical mismatch) as well as case reports of desaturation in some low birth weight newborns.4 The current report by Davis5 provides the results of the first large-scale study of car seat testing in term low birth weight newborns. Unfortunately, although the AAP advice on the need to test certain high-risk infants is quite clear, the current statement does not provide exact thresholds for … Address correspondence to Joel L. Bass MD, Department of Pediatrics, Newton-Wellesley Hospital, 2014 Washington St, Newton, MA 02462. E-mail: jbass{at}partners.org
Preoperative MRI diagnosis of lhermitte-duclos disease: Case report with associated enlarged vessel and syrinx

BACKGROUND The most common primary cerebellar tumor is hemangioblastoma, a lesion which is associated with magnetic resonance imaging (MR)-detectable vascularity in over 60%. Lhermitte-Duclos disease is an uncommon cause of a cerebellar mass that is not typically vascular. METHODS Computed tomography (CT), MRI with and without contrast, and magnetic resonance venography was performed in a patient with a cerebellar mass. RESULTS The cerebellar mass was noted to have a prominent vessel, as well as an associated syrinx. In spite of MRI-detectable vascularity, the striped appearance of the lesion was felt to be typical of Lhermitte-Duclos disease. At surgery, the mass was resected and the diagnosis of Lhermitte-Duclos disease was confirmed. CONCLUSIONS The diagnosis of Lhermitte-Duclos disease should be made when MRI shows a parallel linear "tiger-striped" lesion of the cerebellum. The presence of an enlarged vessel and/or syrinx should not deter one from making the preoperative diagnosis.
Monte Carlo-based computation of the Fisher information matrix in nonstandard settings

The Fisher information matrix plays a central role in the practice and theory of estimation. This matrix provides a summary of the amount of information in the data relative to the quantities of interest. There are many applications of the information matrix in modeling and system identification, including input design, confidence region calculation, and prediction bounds. This paper summarizes some basic principles associated with the information matrix, presents a resampling-based method for computing the information matrix together with some new theory related to efficient implementation, and presents some numerical studies. The resampling-based method relies on an efficient technique for estimating the Hessian matrix, introduced as part of the adaptive ("second-order") form of the simultaneous perturbation stochastic approximation (SPSA) optimization algorithm.
BLOWOUT CONTROL IN TURBINE ENGINE COMBUSTORS

Detection and suppression of lean blowout (LBO) is demonstrated in liquid fueled, non-premixed combustor, based on previous approaches developed for premixed, gas fueled combustors. OH chemiluminescence from the combustion process was used with a threshold based identification of precursor events. Precursor events are short duration local extinction events occurring closer to the blowout limit. These precursors appear random in time, and occur more frequently as the LBO limit is approached. In the combustor studied here, one region of the combustor was found to be less stable, and thus detection there gave greater sensitivity to LBO proximity. To avoid blowout, redistribution of the total fuel inside the combustor between main and pilot nozzles has been used. The idea is to increase the equivalence ratio near the stabilization region of the combustor and provide a locally more stable combustion zone that can anchor the flame in the rest of the combustor. This moves the effective LBO limit to leaner overall mixtures, thus increasing the LBO safety margin. Two nozzles were used for pilot injection and their effectiveness was compared. The atomization and evaporation of the injected pilot fuel may play an important role in the effective stabilization of the combustor near blowout. The sensing method was found to be working even with the piloting. The location of the sensor was found to dictate the type of control scheme used to prevent blowout, using that sensor.
An Intense Pulsed Barium Ion Source

A magnetically insulated diode has been used to produce 30 A/cm2, 250 keV, Ba+ion pulses for 170-200 nsec, using BaF2 as the ion source material. Other operating conditions yield pulse of Ba+ and F+ ions at 300 keV and Ba+2ions at 600 keV. The beam is diagnosed with time-of-flight analysis, Secondary Ion Mass Spectioscopy, and Rutherford backscattering of 2.3 MeV helium ions.