cssi/SciSciGPT-SciSciNet huggingface dataset:
Development and characterization of a three-dimensional radiochromic film stack dosimeter for megavoltage photon beam dosimetry.

Purpose: Three-dimensional (3D) dosimeters are particularly useful for verifying the commissioning of treatment planning and delivery systems, especially with the ever-increasing implementation of complex and conformal radiotherapy techniques such as volumetric modulated arc therapy. However, currently available 3D dosimeters require extensive experience to prepare and analyze, and are subject to large measurement uncertainties. This work aims to provide a more readily implementable 3D dosimeter with the development and characterization of a radiochromic film stack dosimeter for megavoltage photon beam dosimetry. Methods: A film stack dosimeter was developed using Gafchromic® EBT2 films. The dosimeter consists of 22 films separated by 1 mm-thick spacers. A Virtual Water™ phantom was created that maintains the radial film alignment within a maximum uncertainty of 0.3 mm. The film stack dosimeter was characterized using simulations and measurements of 6 MV fields. The absorbed-dose energy dependence and orientation dependence of the film stack dosimeter were investigated using Monte Carlo simulations. The water equivalence of the dosimeter was determined by comparing percentage-depth-dose (PDD) profiles measured with the film stack dosimeter and simulated using Monte Carlo methods. Film stack dosimeter measurements were verified with thermoluminescent dosimeter (TLD) microcube measurements. The film stack dosimeter was also used to verify the delivery of an intensity-modulated radiation therapy (IMRT) procedure. Results: The absorbed-dose energy response of EBT2 film differs less than 1.5% between the calibration and film stack dosimeter geometries for a 6 MV spectrum. Over a series of beam angles ranging from normal incidence to parallel incidence, the overall variation in the response of the film stack dosimeter is within a range of 2.5%. Relative to the response to a normally incident beam, the film stack dosimeter exhibits a 1% under-response when the beam axis is parallel to the film planes. Measured and simulated PDD profiles agree within a root-mean-square difference of 1.3%. In-field film stack dosimeter and TLD measurements agree within 5%, and measurements in the field penumbra agree within 0.5 mm. Film stack dosimeter and TLD measurements have expanded (k = 2) overall measurement uncertainties of 6.2% and 5.8%, respectively. Film stack dosimeter measurements of an IMRT dose distribution have 98% agreement with the treatment planning system dose calculation, using gamma criteria of 3% and 2 mm. Conclusions: The film stack dosimeter is capable of high-resolution, low-uncertainty 3D dose measurements, and can be readily incorporated into an existing film dosimetry program.
The Influence of Solubilizing Chain Stereochemistry on Small Molecule Photovoltaics

Three stereochemically pure isomers and two isomeric mixtures of a solution-processable diketopyrrolopyrrole-containing oligothiophene (SMDPPEH) have been used to study the effect of 2-ethylhexyl solubilizing group stereochemistry on the film morphology and bulk heterojunction (BHJ) solar cell characteristics of small molecule organic photovoltaics. The different SMDPPEH stereoisomer compositions exhibit nearly identical optoelectronic properties in the molecularly dissolved state, as well as in amorphous films blended with PCBM. However, for films in which SMDPPEH crystallization is induced by thermal annealing, significant differences in molecular packing between the different stereoisomer formulations are observed. These differences are borne out in photovoltaic device characteristics for which unannealed devices show very similar behavior, while after annealing the RR- and SS-SMDPPEH enantiomers show blue-shifted peak EQE relative to the SMDPPEH isomer mixtures. Unannealed devices made from the most crystalline stereoisomer, meso RS-SMDPPEH, are not completely amorphous, and show improved photocurrent generation as a result. Unlike the other compounds, after thermal annealing the RS-SMDPPEH devices show reduced device performance. The results reveal that the chirality of commonly used 2-ethylhexyl solubilizing chains can have a significant effect on the morphology, absorption, and optimum processing conditions of small molecule organic thin films used as photovoltaic device active layers.
Dose-response effects of spectrum research cigarettes.

Introduction Experimental cigarettes are needed to conduct studies examining the effects of varying doses of nicotine content on smoking behavior. The National Institute on Drug Abuse contracted with Research Triangle Institute to make such cigarettes available to researchers. The goal of this study was to determine whether cigarettes that vary in nicotine content produce an expected dose-response effect. Method Two studies were conducted. The first study recruited subjects from 3 sites and consisted of a single, within-subject laboratory session. Subjects first smoked 4 puffs on their usual-brand cigarette and then in double-blind, random-order, smoked 4 puffs on each experimental cigarette that contained either low nicotine (LN, 0.4 mg/g), intermediate nicotine (IN, 5.7-5.8 mg/g), or high nicotine (HN, 11.4-12.8 mg/g). Each puffing bout was separated by a 30-min interval. Subjects completed questionnaires and were assessed for vital signs after each cigarette. The second study involved 1 site and used a between-subject design in which subjects were assigned to 1 of the 3 experimental cigarettes for 1 week. Subjective responses and biomarkers of exposure were assessed. Results In the first study, significant dose-response effects were observed, particularly between the LN and HN cigarettes. The second study showed decreases in cigarette smoking and exposure biomarkers predominantly in the LN group, with no changes in the HN cigarette group. Conclusions These results are similar to those observed in prior literature, confirming that these experimental cigarettes can be used safely and with the expected pharmacological effects.
The use of dental crown heights for constructing age profiles of red deer and similar species in archaeological samples

Abstract The analysis of dental crown heights in a sample of known-age American Red deer (known in America as “elk”) has permitted the derivation of formulae for the prediction of age from crown height. The ages predicted from crown heights closely approximate true ages, when both predicted and true ages are grouped into broad, but still useful age classes. At least for the Red deer or “elk” dP 4 , M 2 and M 3 , age prediction formulae very similar to the empirically derived ones may be constructed by making certain hypothetical assumptions about the nature and rate of crown attrition. This suggests that these assumptions may be used to construct age prediction formulae in situations where an empirical relationship between age and crown height has not been or cannot be established. With certain provisos noted in the text, the age prediction formulae that result will probably provide reasonably reliable age profiles for the numerous ungulate species whose teeth are similar in structure to those of Red deer or “elk” and at least as hypsodont.
Impact of electronic density of states on electroluminescence refrigeration

Electroluminescence refrigeration in light emitting diodes is studied by taking into account carrier transport, carrier recombination, and influence of the dimensionality of electronic density of states (DOS) in active region. The cooling process happens when carriers transport from the metal contacts to the barrier layers. For a given bias voltage, the cooling power density decreases monotonically with the dimension of the DOS and increases as the carrier effective masses increases.
Multicriteria high-speed rail route selection: application to Malaysia's high-speed rail corridor prioritization

This paper reviews the literature on multicriteria decision analysis in transportation and provides a case study of high-speed rail (HSR) corridor/route selection using multicriteria methods in the context of HSR corridor prioritization in Malaysia. Using the screening method proposed by Hagler and Todorovich and the ELECTRE I multicriteria method, it is found that the southbound corridor from Kuala Lumpur to Singapore has the highest priority, followed by the eastbound corridor to Kuantan, and northbound to Georgetown. HSR trains could potentially reduce the trip times to Singapore, Kuantan, and Georgetown from Kuala Lumpur, as compared to driving, by 65–73%. The results of this study can be used to assist in the planning of HSR and/or integrated transportation systems in Malaysia. The same methods can be used to evaluate potential HSR corridors/routes in other countries or regions.
30 Characteristics of symptoms and functional gastric tests in patients referred for electrogastrography (EGG) and GET

The association between symptoms (Sx) and gastric function tests remains unclear. Aims: To determine whether specific clinical complaints and a history of GERD were associated with gastric emptying (GET) or EGG findings. Charts of 163 pts (39 M, 124 F) undergoing both GET and EGG were reviewed for weight, diabetes and complaints of nausea, pain, vomiting, bloating and altered bowel habits. The 1 and 2 hr GET, final EGG diagnosis and baseline frequency distribution of power, and volume (vol.) tolerated during the water load test (WLT) were noted. Data is reported as median, 5–95 percentile. Chi-squared- and Wilcoxon-Mann-Whitney-tests were used. Results: Women (F) complained of pain more than men (M) 70% vs. 43% (p = 0.002) and more men had altered bowel habits 77% vs. 57% (p = 0.02). No gender differences were seen with other Sx. F weighed less and drank less than M during the WLT (480 vs. 604 ml, p = 0.001). GET was slower in F than M: 63%, with 7–97 (median, 5–95 percentile) emptying in 2 hrs in F vs. 78%, 27–99, in M, p < 0.001. There was no gender difference in EGG diagnoses. Diabetics weighed more (187 vs. 146 lb, p < 0.0001) and were older (52 vs. 42, p < 0.01) than nondiabetics who had more a normal baseline EGG than diabetics. Overall, the Sx of pain was associated with a lower vol. tolerated on WLT, 450ml vs. 600 ml, p = 0.002. Only the Sx of pain was associated with delayed GET, which did not persist when adjusted for gender. No Sx complaint was associated with specific EGG diagnoses. GERD was associated with greater weight (156 lb vs. 140 lb, p < 0.05) but not with delayed GET or any specific EGG findings. Conclusions: GET was slower in F than in M. Pain was a more common presentation in F and the association of pain with a lower WLT vol. suggests that this Sx is related to an abnormal sensory process and suggests a different therapeutic approach to such pts.
PREDICTION OF DEVELOPMENTAL OUTCOME AT TWO YEARS IN VERY LOW BIRTH WEIGHT(VLBW) INFANTS AFTER SURFACTANT. † 1625

PREDICTION OF DEVELOPMENTAL OUTCOME AT TWO YEARS IN VERY LOW BIRTH WEIGHT(VLBW) INFANTS AFTER SURFACTANT. † 1625
Buffer model and management in distributed multimedia presentation systems

The delivery of continuous and synchronous multimedia data from a database (or file) server to multiple destinations over a network presents new challenges in the area of buffer management. Many factors that were not considered in conventional buffer management must be examined. In this paper, we investigate the principles of buffer model and management for multimedia data presentations in distributed systems. The primary goal is to minimize the response time of multimedia presentations while ensuring that all continuity and synchronization requirements are satisfied. A framework for buffer model and management is introduced. Minimum buffering requirements at both client and server sides to guarantee the continuity and synchrony of the presentation of multimedia data are examined. A prefetching and replacement strategy which satisfies these requirements is then offered. These principles and techniques provide users with the full range of information required to develop a distributed system for multimedia presentations.
Principal solutions of positive linear Hamiltonian systems

The Hamiltonian system Y ′ = BY + CZ , Z ′ = – AY – B * Z is considered where the coefficients are continuous on I = [a, ∞, C = C * ≧ 0, and A = A * ≦ 0. A solution ( Y , Z ) satisfying Y * Z = Z * Y is defined to be principal (coprincipal) provided that (i) Y −1 exists on I ( Z −1 exists on I ) and (ii) as t →∞ ( as t → ∞). Three conditions are given which are separtely equivalent to the condition that a solution is principal iff it is coprincipal. For a self-adjoint scalar operator L of order 2 n , this problem is related to the deficiency index problem and to a problem of Anderson and Lazer (1970) which concerns the number of lnearly independent solutions of L ( y ) =0 satisfying y (k) ∈ (a, ∞) (k = 0, …, n ).
Reflections on Seattle 1999

Humans seem to need commemorative celebrations. The importance of commem? orations can hardly be underestimated. Beyond reaffirming our common species identity, they often help us recall important milestones that the complex of cultural and political influences conspire to facilitate forgetting. 2009 is auspicious in this regard: it is the 150th anniversary of the publication of Darwin's Origin of the Species (but have we forgotten Marx's A Contribution to the Critique of Political Economy, an important precursor to Capitall a "forgetting" that has clear ideological roots in the disparagement of Marx and historical materialism, which is deeply ingrained in our collective discourse); the 200th anniversary of the birth of Darwin and of Abraham Lincoln, the latter an occasion for the publication of dozens of recent books on the Great Emancipator and a chance to reflect on the fate of blacks since that fateful proclamation. It is also the fiftieth anniversary of the Cuban Revolution. Now, in much more restricted precincts, we recall the dramatic second "Battle of Seattle"?second because the first one was in 1919 when the working people of the city "downed tools" and conducted a general strike, an event that has attracted only a few historians. The mass demonstrations at the meeting of the World Trade Organization (WTO) were conducted in protest against capitalist globalization, proclaimed by media, politicians, and corporate America as a boon to the country and only temporarily hurtful to some workers. The common hype was that the jobs shipped to Mexico and elsewhere were mainly done by immigrants and in industries that are low paid, and Americans don't want to work in anyway. Of course, this explanation was a gross falsehood. Outsourcing, combined with systematic disinvestments in US production industries, destroyed many of the best-paying working class jobs, laid countless
Preliminary studies on the venom of the colubrid snake Rhabdophis subminatus (red-necked keelback)

Abstract Following the bite by Rhabdophis subminatus , preliminary studies were instituted on its venom to determine the mechanism of the clinical poisoining. A method for milking these snakes is presented. The i.v. ld 50 in mice was 1.29 mg/kg. Three peaks were obtained on Sephadex G-100 and although none were lethal by themselves, a combination of two of the peaks produced immediate death in mice. The venom had no phosphodiesterase, fibrinolytic thrombin-like activities, but it did have some phospholipase activity. Further biochemical and pharmacological studies are in progress.
No evidence of polar warming during penultimate interglacial

The Atlantic Meridional Overturning Circulation (AMOC), driven by temperature and salinity gradients, is an important component of the climate system; it transfers an enormous amount of heat via ocean currents and atmospheric circulation to high northern latitudes and hence has bearing on climate in the region. Freshening of the surface ocean could weaken AMOC. But during warm interglacial periods the effect of a fresh surface ocean on AMOC may be muted. In fact, climate models predict that heat transfer from the North Atlantic to the Arctic may increase over the 21st century. A series of interconnected processes in the North Atlantic, known as polar amplification, could cause the Arctic to warm up faster compared to the rest of the world. It could even lead to ice-free conditions in the Arctic.
Plasma potassium and sodium concentrations in active and hibernating golden-mantled ground squirrels, Citellus lateralis

Abstract 1. 1. Plasma potassium and sodium concentrations in active and hibernating ground squirrels were determined using heart puncture and flame photometry. 2. 2. Animals in hibernation with a body temperature of 5°C have a significantly lower plasma potassium concentration than active animals, but the plasma sodium is statistically the same in both physiological states. 3. 3. The adaptive value of such a mechanism is speculated upon. 4. 4. Conflicting evidence from the literature on these physiological phenomena is reviewed, and the possible reasons for the conflicts are discussed.
A numerical procedure for solving 2D phase-field model problems

We present a general 2D phase-field model, but without anisotropy, applied to freezing into a supercooled melt of pure nickel. The complete numerical procedure and details of assigning the numerical parameters are provided; convergence of the numerical method is demonstrated by conducting grid function convergence tests. The physics of solidification problems such as conditions for nucleation and crystal growth rate are discussed theoretically and shown to display at least qualitative agreement numerically. In particular, comparison of the computed critical radius with the theoretical one and the consistency of the computational dendrite structure for different Stefan numbers, the relationship between the growth rate and the Stefan number, etc., with the theoretical and experimental evidence indicate that phase-field models are able to capture the physics of supercooled solidification.
The a Priori Calculation of the Diffuse Reflectance of a Turbid Medium

A derivation has been given by Hartel which relates the angular distribution of multiple scatter to that of single scatter, as determined by the Mie theory. Hartel's result is used to generalize Thiessing's equations for a medium which both scatters and absorbs radiation. The result is similar to the two-parameter theories used by numerous other workers, the difference being that the formulation given here constitutes an a priori method which relates the multiple scattering characteristics to the single scatter problem, whose solution is well known. Reflectance properties are calculated by numerically solving the equations for two illustrative cases.
The effect of application frequency on epidermal carcinogenesis assays

Classic mouse skin-painting assays of such highly-complex mixtures as petroleums and synthetic fuels may lead to severe local cytotoxic effects that can alter tumorigenesis. This effect can be particularly disruptive in dose-response studies where a wide range of doses is employed. The experiments described here illustrate that frequency of exposure may be more important than the concentration of individual doses. C3Hf/Bd mice were exposed to 2 shale oils in experiments in which a constant weekly dose was either applied once or divided into 2 or 4 equal parts and applied either twice or 4 times each week. In experiments with either oil, a single weekly application was more effective in total tumor production and less cytotoxic than more frequent application of less-concentrated doses.
Integration and Exclusion in the Telephone Equipment Industry

Introduction, 249. — I. Organization of the market, 250; Western Electric and the Bell System, 250; non-Bell telephone companies and equipment producers, 252. — II. Performance, 255; Western's prices and profits, 255; Western's cost accounting, 260; innovation, 262. — III. Policy choices, 265.
The determination of long-range misorientations in the microstructure of materials

Abstract In studying the fundamental mechanism of deformation and subsequent annealing response of metals, it is necessary to analyze the crystallographic misorientations present in the material. The development of the average subgrain misorientation during rolling is well documented, but how misorientations derive on a local scale is rarely investigated. For energetic considerations the misorientation between two neighboring grains can be expressed simply by the misorientation angle, with the misorientation axis ignored. This is no longer sufficient when spatial aspects of misorientations are to be considered. A general description is obtained with the definition of a misorientation correlation index (MCI). The variation of the MCI with respect to distance describes long-range misorientations over tens of (sub-) grains. This new method has been used to analyze a channel-die compressed aluminum single crystal. Preliminary results indicate the non-laminar flow behavior of the metal even at a true strain as small as 0.2.
Reactivity analysis of solution reactors for medical-radioisotope production

One of the primary methods to produce medical isotopes, such as 99 Mo, is by irradiation of uranium targets in heterogeneous reactors. Solution reactors present a potential alternative to produce medical isotopes. The medical isotope production reactor concept has been proposed to produce medical isotopes with lower uranium consumption and waste than the corresponding fuel consumption and waste in heterogeneous reactors. Commercial production of medical isotopes in solution reactors requires steady-state operation at about 200 kW. At this power regime, fuelsolution temperature increase and radiolytic-gas bubble formation introduce a negative reactivity feedback that has to be mitigated. This work analyzes the reactivity effects on the operation of solution reactors for the production of medical isotopes and provides some reactor characteristics that may mitigate the negative reactivity feedback introduced by the increase in the fuel-solution temperature and the formation of radiolytic-gas bubbles. � 2003 Elsevier B.V. All rights reserved.
Simultaneous measurement of tocopherols and tocopheryl quinones in tissue fractions using high-performance liquid chromatography with redox-cycling electrochemical detection

Abstract Tocopherols and tocopheryl quinones in lipid extracts of biological samples have primarily been measured using relatively insensitive ultraviolet detection methods. Oxidative electrochemical detection increases both the sensitivity and selectivity when measuring the tocopherols. We have developed an electrochemical detection system which sequentially reduces and oxidizes tocopheryl metabolites eluted from a reversed-phase high-performance liquid chromatography column, achieving sensitivities of about 0.05 pmol for both the tocopherols and their quinones. Using a rapid and mild extraction procedure, endogenous levels of α- and γ-tocopherol as well as their respective quinones were measured in homogenates of chicken liver and muscle, and in dilute preparations of rat liver microsomes. The principle of the detection system could be applied to the determination of tocopheryl dihydroquinones, ubiquinols and ubiquinones with slight modifications to the mobile phase buffer and the electrode potentials of the detector.
Design of a general biquadratic filter section with only transconductances and grounded capacitors

A method is presented for the implementation of all stable second-order filters using only tunable transconductance elements and grounded capacitors (TGC filters). Although other voltage-to-current converters can be used, the simple four-transistor transconductance is particularly convenient because of its reduced circuitry. The synthesis technique is based on the signal-flow-graph corresponding to the state-space model of a second-order section. The approach is general and can be applied to obtain higher-order filters in the same manner, provided that the corresponding signal flow graph exists. >
Adult Suicide Mortality in the United States: Marital Status, Family Size, Socioeconomic Status, and Differences by Sex

OBJECTIVE: This paper addresses the relationship between suicide mortality and family structure and socioeconomic status for U.S. adult men and women. METHODS: We use Cox proportional hazard models and individual level, prospective data from the National Health Interview Survey Linked Mortality File (1986-2002) to examine adult suicide mortality. RESULTS: Larger families and employment are associated with lower risks of suicide for both men and women. Low levels of education or being divorced or separated, widowed, or never married are associated with increased risks of suicide among men, but not among women. CONCLUSIONS: We find important sex differences in the relationship between suicide mortality and marital status and education. Future suicide research should use both aggregate and individual level data and recognize important sex differences in the relationship between risk factors and suicide mortality-a central cause of preventable death in the United States. Language: en
On the time-scale of deglaciation: Atlantic deep-sea sediments and Gulf of Mexico

Deglaciation as seen in the δ18O record of deep-sea sediments starts about 14,000 yrs. ago. Measured bulk 14C ages are too old by 1000–2000 yrs. in the central Atlantic compared with ages derived from climate correlation. This conclusion rests on the observation that deglaciation occurs in two major steps, separated by a pause, and on the hypothesis that this pause is correlative to the Younger Dryas cold period. The Gulf of Mexico record is readily correlated with the deep-sea record if it is assumed that the appearance of Globorotalia menardii is retarded with respect to the tropical Atlantic, by about 2000 yrs. The major meltwater spike then dates near 9000 yrs. ago, rather than at 13,500 yrs. B.P. (as assumed by Kennett and Shackleton, 1975) or 11,500 yrs. B.P. (as in Emiliani et al., 1975).
Tick repellents: past, present, and future.

Ticks are important vectors of human and animal diseases. One important protective measure against ticks is the use of personal arthropod repellents. Deet and the synthetic pyrethroid permethrin currently serve as the primary personal protective measures against ticks. Concern over the safety of deet and its low repellency against some tick species has led to a search for new user-approved, efficacious tick repellents. In this article, we review the history and efficacy of tick repellents, discovery of new repellents, and areas in need of attention such as assay methodology, repellent formulation, and the lack of information about the physiology of repellency.
Repeat Lumbar Puncture: CSF Lactic Acid Levels are Predictive of Cure with Acute Bacterial Meningitis

A common clinical problem concerns the utility of repeat lumbar puncture (LP) in adults with acute bacterial meningitis (ABM), e.g., pneumococcal meningitis [1]. An LP is initially done for diagnostic purposes in patients with suspected ABM, i.e., diagnostic lumbar puncture (DLP). A repeat LP (RLP) may be done 1–3 days after the initial DLP, if the patient shows no improvement. If a patient with ABM is not doing well after three days, adequacy of antimicrobial therapy is the main concern. Other reasons for RLP is to detect possible intracranial complications of ABM unrelated to adequacy of therapy [1–2].
On the relationship between shear angle and wrinkling of textile composite preforms

Abstract As a result of the increased use of composite materials in structural as well as non-structural applications, the need for a better understanding of the mechanics of fibre preforms during forming operations is imperative. During processes that involve automated moulding or forming of composite parts, wrinkling is one of the most common flaws, often leading to unexpected failures. A number of kinematic models have been developed to predict the conformability and wrinkling of fabrics. However, these have the shortcoming that they only deal with a single fabric layer, and in order to predict wrinkling they need to have the locking angle (determined experimentally) as an input. This paper presents the results of a study that investigated the relationship between the shear angle and wrinkling in a single fabric layer and a brief extension of the findings to multi-layer set-ups. A number of fabric parameters (friction, tow size and spacing) were related to the locking angle. A model to predict a lower bound for the locking angle (using pin-joint theory) is also presented, along with a discussion of factors that support the development of a combined mechanistic kinematic model.
Transient groundwater impacts on the development of paleoclimatic lake records in semi‐arid environments

Lacustrine sedimentary deposits are a primary archive of terrestrial paleoclimatic information, and groundwater fluxes under arid climates can dominate water budgets in lake and playa environments. In this paper, we investigate the effects of basin-scale water table fluctuations on lacustrine paleoclimatic records in arid regions using the hydrogeologic model MWT3D. Boundary conditions for paleo-recharge over the past 57 ka, land surface topography, the location of lakes, and subsurface geology were based on information available for a 600-km cross section across the western Murray Basin, Australia. Results indicate the importance of the physical interaction between the water table and the land surface in controlling the location and the timing of formation of paleoclimatic lacustrine records. Lakes in different positions across the watershed preserved different records of climate (wet versus dry), although the same recharge history was applied. Changes in groundwater seepage to the surface lagged behind the climatic signal between 500 and 220 years across the basin. The size of the flow system, specifically the distance from the local discharge point to the adjacent groundwater divide, was the primary control on the time lag. With large fluctuations in water table elevation (>50 m) this distance changes considerably from wet to dry climatic conditions. Our results are largely consistent with observed paleoclimatic records derived from lakes across the Murray Basin.
A Pilot Dose-Escalation Safety Study of Tenecteplase in Acute Ischemic Stroke

Background and Purpose— Recombinant tissue-type plasminogen activator (rtPA) is the only approved treatment in acute ischemic stroke. However, intracerebral hemorrhage (ICH) occurs in 6.4% of patients treated with rtPA and limits its use. Tenecteplase (TNK) is a modified form of rtPA, with longer half-life and greater fibrin specificity. Patients after myocardial infarction had fewer systemic hemorrhages when treated with TNK compared with rtPA. This open-label, dose-escalation safety study was conducted to develop initial experience with TNK in the treatment of ischemic stroke. Methods— Eligible patients were treated with an intravenous bolus infusion of TNK within 3 hours of stroke onset. The dose escalation was conducted in tiers of 25 patients, starting at 0.1 mg/kg, to a planned maximum of 0.6 mg/kg. The primary endpoint was symptomatic intracranial hemorrhage within 36 hours of treatment. All patients were followed-up for 3 months. Results— Eighty-eight (88) patients were treated in 4 dosing tiers. ...
Pancreatic Islet Transplants and IDO: When Starving the Enemy Does You Good

Competition for essential nutrients and/or release of toxic metabolites are mechanisms highly conserved in both bacteria and higher organisms as innate defense systems from external pathogens. One such mechanism is based on the activation of indoleamine 2,3-dioxygenase (IDO), an enzyme that catalyzes the catabolism of the essential amino acid tryptophan (rev. in 1). By depleting tryptophan, IDO limits the ability of many pathogens to synthesize proteins. In addition, activation of the enzyme results in the accumulation of tryptophan breakdown products, collectively known as kynurenines, some of which are toxic to bacteria and parasites. Consistent with the enzyme effects on the containment of pathogens' replication and invasion, constitutive IDO expression in higher organisms is found at mucosal interfaces, such as the mucosa of the intestine and the lung, which are barriers to external microorganisms (2). However, chronic inflammatory processes, particularly those sustained by interferon-driven immune responses, can induce high levels of IDO in many cell types including epithelial, endothelial, and myeloid cells (3–7). Intriguingly, under these conditions, active IDO appears to mute lymphocyte immune responses by “starving” actively proliferating leukocytes, thereby limiting the uncontrolled spread of inflammation. Both high levels of IDO as well as activation of the enzyme by redox active compounds present in the inflammatory microenvironment are required for the immunosuppressive effect (8). The ability of IDO to regulate lymphocyte functions has prompted many investigators to test the effect of IDO overexpression at transplantation sites as a mean to avert destructive allogeneic immune responses against heart, skin, lung, cornea, and bone marrow grafts (9 …
On the medicalization of medical anthropology.

The following address was presented at the Annual Meeting of the Society for Medical Anthropology (SMA), November 21,1997, Washington, DC, by outgoing SMA president Carole Browner. It has been edited slightly for publication.
Leadership Development: A Collaborative Approach

To meet the unprecedented demand for well-prepared leaders, a regional approach can be helpful that draws on a range of providers, offering a variety of development opportunities for aspiring and practicing leaders.
Approximating elementary functions with symmetric bipartite tables

This paper presents a high-speed method for function approximation that employs symmetric bipartite tables. This method performs two parallel table lookups to obtain a carry-save (borrow-save) function approximation, which is either converted to a two's complement number or is Booth encoded. Compared to previous methods for bipartite table approximations, this method uses less memory by taking advantage of symmetry and leading zeros in one of the two tables. It also has a closed-form solution for the table entries, provides tight bounds on the maximum absolute error, and can be applied to a wide range of functions. A variation of this method provides accurate initial approximations that are useful in multiplicative divide and square root algorithms.
Histidine content of low-molecular-weight beef proteins influences nonheme iron bioavailability in Caco-2 cells.

The objective of this study was to isolate and characterize beef muscle proteins that enhance nonheme iron bioavailability. Beef sirloin was cooked, lyophilized and reconstituted with water before in vitro digestion. After centrifugation, the digest supernatant was sequentially ultrafiltered using 10- and 1-kDa molecular weight cut-off membranes. Nonheme iron bioavailability was assessed by Caco-2 cell monolayer (59)Fe uptake using an extrinsic labeling method. All ultrafiltration fractions significantly (P < 0.001) increased iron solubility at pH 6.0, compared with the blank. However, iron uptake was significantly (P < 0.001) greater than the blank only in the presence of the 1-kDa retentate (1KR). Therefore, the 1KR was chosen for further analysis. Immobilized metal affinity chromatography (IMAC) of the 1KR yielded four fractions, i.e., three distinct fractions (F1, F3, F4) and one fraction (F2) comprised of a few closely associated peaks. All four IMAC fractions resulted in significantly (P < 0.001) greater (two- to fivefold) iron solubility at pH 6.0, compared with the blank. Iron uptake with F2 and F4 was significantly greater than the blank (P < 0.001 and P < 0.05, respectively). Gel electrophoresis and matrix-assisted laser desorption/ionization analysis illustrated that F1-F4 contained many peptides ranging from 1- to 7-kDa. Amino acid composition analysis revealed that histidine concentration increased progressively from F1 to F4, corresponding to a general, but not parallel increase in iron solubility and uptake. Our results suggest that the enhancement of nonheme iron absorption by beef may be due to peptides produced during gastrointestinal digestion and that histidine content may be important.
Male traits associated with attractiveness in Conambo, Ecuador

This study investigated male attractiveness rankings in a small-scale Amazonian society. In the rural community of Conambo, Ecuador, men and women practice self-sufficient horticulture, men hunt, and, traditionally, men have experienced a high rate of mortality due to homicide. We tested whether male attractiveness rankings would be related to male age, warriorship, hunting ability, status, coalitional affiliation, and female age. Twenty-five women aged between 14 and 78 years ranked photographs of 29 local men aged between 16 and 74 years for attractiveness in addition to warriorship, hunting ability, and status. Results revealed that male age was negatively correlated (r=−.683, p=.01) with female rankings of male attractiveness. Warriorship (r=.517, p=.005), status (r=.489, p=.008), and hunting ability (r=.577, p=.001) were found to be positively correlated with attractiveness, after controlling for age. Additionally, females showed a bias for males in their in-group when ranking attractiveness (one-sample t test: T29=16.727, p<.001). Attention is given to male age and coalitional affiliation as factors important in attractiveness rankings; warriorship and hunting ability also serve as ecologically salient features of male social worth. These findings contribute to a broader understanding of human attractiveness research by adding a new case study to the literature that documents previously unreported findings from a cultural context that is significantly different from the standard university-level student sample.
Intravenous Morphine at 0.1 mg/kg Is Not Effective for Controlling Severe Acute Pain In the Majority of Patients

Study objective The objective was to quantify the analgesic effect of a dose of intravenous morphine, 0.1 mg/kg, to emergency department (ED) patients presenting in acute, severe pain. Methods This was a prospective convenience cohort of patients aged 21 to 65 years and presenting to an academic urban ED with acute, severe pain. Patients rated their pain intensity on a validated 11-point verbal numeric rating scale ranging from 0, "no pain," to 10, "worst possible pain," immediately before they received 0.1 mg of intravenous morphine per kilogram of body weight and 30 minutes later. The main outcome was proportion of patients whose pain decreased by less than 50% during the 30-minute interval. Results Of 119 patients who received intravenous morphine at 0.1 mg/kg, the average age was 42 years (SD=11 years), 55% were female patients, 65% were Hispanic, 28% were black, and 7% were classified as other. The median numeric rating scale pain score at baseline was 10 (interquartile range 9 to 10). Sixty-seven percent (95% confidence interval 58% to 76%) of the patients receiving intravenous morphine at 0.1 mg/kg reported a less than 50% decrease in pain. No patient required an opioid antagonist at any time during or after the study period. Conclusion The data suggest that a 0.1 mg/kg dose of morphine may be too low to adequately control acute severe pain.
Appropriate Surveillance for Late Complications in Patients in Remission from Hodgkin Lymphoma

Once considered to be incurable, now most patients with the diagnosis of Hodgkin lymphoma (HL) survive and are cured of their disease. Although HL survivors are out living their disease, they continue to have increased morbidity and mortality compared to their age-matched and sex-matched peers in the general population. Late complications of their treatment are well documented and include cardiovascular diseases, pulmonary diseases, endocrine dysfunction and second malignancy. Research exploring appropriate surveillance for these complications is lacking. However, evidence to support surveillance is mounting and many are publishing consensus-based guidelines recommending surveillance for these anticipated complications. This review will summarize the most recent literature addressing the appropriate surveillance for late complications in patients in remission from HL.
Effect of large ion angular momentum spread and high current on inertial electrostatic confinement potential structures

Prior inertial electrostatic confinement (IEC) studies have assumed that very low angular momentum (zero in the ideal case) is necessary to achieve a potential well structure capable of trapping energetic ions in the center of a spherical device. However, the present study shows that high-current ion beams having large-angular-momentum spread can also form deep potential well traps.
Properties of Si/Cs/O nanocluster thin films with negative electron affinity

Thin films of Si/Cs/O nanoclusters have been synthesized by the technique of supersaturated thermal vaporization of Si and Cs in an oxygen background gas. These films, which were deposited onto conducting or semiconducting substrates, exhibit negative electron affinity (NEA) as evidenced by ultraviolet photoemission spectroscopy (UPS). Photo and field electron emission properties of these nanocluster films were investigated with photo-electron emission microscopy (PEEM), field electron emission microscopy (FEEM), and current-voltage measurements. Flat cathodes covered with thin films of Si/Cs/O nanoclusters exhibited high current outputs and low turn-on fields. The films’ NEA is unaffected by air exposure and is stable to high temperature annealing (550 TC). A field emission display unit with a simple diode structure containing a flat cathode coated with a patterned thin film of Si/Cs/O nanoclusters has also been built to demonstrate the potential application of this material in cold cathode electron emitting devices, particularly field emission flat panel displays.
Nerve innervation of the hand and associated nerve dominance aggregates in the somatosensory cortex of a primate (squirrel monkey)

The cutaneous innervation territories of the median, ulnar, and radial nerves to the hand were determined from neurophysiological recordings of peripheral mechanoreceptor axons in adult squirrel monkeys. These territories were then related to cutaneous receptive fields of cortical area 3b neurons to determine how low-threshold inputs from each hand nerve map onto the primary somatosensory cortex. The results indicate that mechanoreceptor axons in each nerve innervate a continuous skin territory covering about 40% of the hand surface. The total territory of each nerve contains subregions of skin that are either autonomously innervated by that nerve or that receive overlapping innervation from more than one nerve. The autonomous, overlap, and total territories of each nerve are relatively constant from hand to hand. In the area 3b cortex, low-threshold afferents from each nerve provide inputs to aggregates of cortical neurons. The cortical aggregates relating to the median and ulnar nerves are arranged as continuous, rostrocaudally oriented bands, whereas aggregates relating to the radial nerve are discontinuous and more patch-like. Similar patterns of bands and patches, and similar compression ratios of skin/cortical area, are seen across different monkeys. These findings demonstrate that the primary somatosensory cortex of normal adult primates contains bands or patches of neurons that are dominantly activated by low-threshold inputs from specific hand nerves. This approach of delineating nerve territories and their related cortical dominance aggregates provides a useful means of analyzing cortical images of nerves and of quantitating peripheral and central patterns of deprivation after nerve injury.
Buried-oxide silicon-on-insulator structures. II. Waveguide grating couplers

For pt.I, see ibid., vol.28, no.1, p.157-63 (1992). Grating couplers formed in buried-oxide silicon-on-insulator structures are analyzed using both a convergent Block wave approach and a simple approximate method. Strong interface reflections that occur during grating coupling can cause interference effects which result in variations in coupling efficiency and coupling length by an order of magnitude when varying grating period and film thickness parameters. Results indicate that proper coupler design is essential in order to obtain efficient coupling. >
Shell weight as a function of intertidal height in a littoral population of pelecypods

ChezMytilus, le poids de la coquille, rapporte a une unite de poids des parties molles, decroit a mesure que les populations considerees occupent un niveau plus rapproche de la surface et sont soumises davantage au jeu des marees. La coquille la plus lourde (poids relatif) se rencontre dans les populations immergees en permanence. La decroissance du poids de la coquille est proportionnelle a la duree d'emersion quotidienne. Il y a un rapport direct entre le poids relatif de la coquille et le nombre d'heures passees journellement sous l'eau par chaque population et ce nombre rend compte des differences observees d'une population a l'autre.
The Fossil Galliform Bird Paraortygoides from the Lower Eocene of the United Kingdom

Abstract A new fossil species assigned to the galliform genus Paraortygoides Mayr is described from the Lower Eocene (Ypresian Stage) London Clay Formation of the United Kingdom. Paraortygoides radagasti, n. sp., is referred to the genus on the basis of comparisons with other specimens from the Middle Eocene deposit of Messel (Hessen, Germany). Because of the three-dimensional preservation of this fossil material, P. radagasti contributes new information pertaining to the morphology of the genus Paraortygoides, in particular with regard to the thoracic vertebrae, tarsometatarsus, and toes. This genus, for example, is distinguished from other currently known fossil and extant galliform birds by the presence of deep pneumatic excavations in the lateral sides of the thoracic vertebrae. The results of a preliminary phylogenetic analysis suggest that Paraortygoides is basal within Galliformes (as already proposed by Mayr [2000]); monophyly of the order is supported with Megapodiidae as the basal sister taxon w...
Comparison of Tasseled Cap-based Landsat data structures for use in forest disturbance detection

Landsat satellite data has become ubiquitous in regional-scale forest disturbance detection. The Tasseled Cap (TC) transformation for Landsat data has been used in several disturbance-mapping projects because of its ability to highlight relevant vegetation changes. We used an automated composite analysis procedure to test four multi-date variants of the TC transformation (called ‘‘data structures’’ here) in their ability to facilitate identification of stand-replacing disturbance. Data structures tested included one with all three TC indices (brightness, greenness, wetness), one with just brightness and greenness, one with just wetness, and one called the Disturbance Index (DI) which is a novel combination of the three TC indices. Data structures were tested in the St. Petersburg region of Russia and in two ecologically distinct regions of Washington State in the US. In almost all cases, the TC variants produced more accurate change classifications than multi-date stacks of the original Landsat reflectance data. In general, there was little overall difference between the TC-derived data structures. However, DI performed better than the others at the Russian study area, where slower succession rates likely produce the most durable disturbance signal. Also, at the highly productive western Washington site, where the disturbance signal is likely the most ephemeral, DI and wetness performed worse than the larger data structures when a longer monitoring interval was used (eight years between image acquisitions instead of four). This suggests that both local forest recovery rates and the re-sampling interval should be considered in choosing a Landsat transformation for use in stand-replacing disturbance detection.