cssi/SciSciGPT-SciSciNet huggingface dataset:
Cardioactive properties of d-tubocurarine with and without preservatives.

The authors previously reported that d-tubo-curarinc (dTc) had a negative inotropic effect on isolated perfused rabbit hearts; the effect was concentration-dependent and related to myocardial calcium exchange. This paper reports results of a concentration–response study of die effects of crystalline dTc, various commercial preparations of dTc, and their preservatives on the contractile amplitude of stimulated rabbit atrial strips. Crystalline dTc produced a slight positive inotropic effect which was significantly different from control, while the commercial preparation, Tubarinc (used in previous studies), produced depression with 43 ± 10-5 to 5.4 X 10-4 [M]. This depression closely paralleled that produced by antibacterial preservative, p-chloro-m-cresol, while the antioxidant preservative, K mctabisulfite, produced minor depression. Other commercial preparations containing antibacterial preservatives also produced depression similar to the depression produced by their antibacterial preservatives. The commercial preparations dispensed without antibacterial preservatives produced relatively little depression. The authors conclude that their previous results were due to the preservative, p-chloro-m-cresol, and not to dTc
Ion properties of the high-latitude middle-atmosphere

Investigations of high-latitude, middle-atmosphere ion properties have been conducted using rocket probe techniques. Electrodynamics studies have addressed: mesospheric dynamics and small-scale structure (the MAC/EPSILON Campaign during October-November 1977); ionization effects associated with highly energetic greater than or equal to 1 MeV) precipitating electrons (the MAC/REP Program during May 1990); and the characteristics of noctilucent cloud (NLC) and polar mesosphere summer echo (PMSE) regions (the NLC-91 Campaign during July-August 1991). Recent developments in Gerdien condenser probe theory, using computational fluid dynamics to model ion collection, have resulted in more accurate evaluation of the ion mobilities and number densities. Measurements of very small ion mobilities are thought to indicate an aerosol ion presence in the upper mesosphere.
Congestion control for low-priority filler traffic

As the cost of Internet access rises and the amount of deployed bandwidth increases, a way to make efficient use of the oft-unused bandwidth is desired. Simply providing a lower priority for traffic than best effort allows this bandwidth to be used without noticeable interference with regular traffic. Because bursts of normal traffic are given priority over this background, or filler, traffic, a more aggressive congestion control protocol is called for in the filler traffic. In our paper, we compare numerous versions of TCP-like congestion control of our own design, over which to implement low-priority traffic, by using the unused bandwidth at any given time. These protocols are divided into six “classes,” which differ by the core congestion control algorithm and use different constants. Using the ns-2 network simulator, we collected network traces using each of our protocols in different network configurations, with multiple parameters for each configuration. These configurations simulated high- and low-bandwidth and latency networks. We compared the resulting throughput and sharing - the cumulative variation of throughput over each stream, normalized by the total throughput over the link - to our chosen baseline, TCP Sack. Most of the basic algorithms performed as well as or better than Sack in a background traffic environment, especially in terms of throughput. Using features from multiple classes, we also designed a more complex protocol that performed better than Sack in almost every environment, and performed better than the other algorithms in general.
Impediments to Cross-national Research: Problems of Reliability and Validity

Extrapolating from experiences in three European countries, the authors enumerate some of the practical problems in conducting criminal court research and gathering data cross-nationally. Within the context of the key concepts of validity and reliability, the impact of substantial research problems are discussed. The authors conclude that although compromises must be made, if care is taken, the compromises do not have to damage the ultimate worth of the research. The inherent value of cross-national research makes it incumbent upon criminal justice scholars to find ways to overcome unavoidable problems.
Conformation of polyriboadenylic acid: pH and temperature dependence

Evidence is presented that polyriboadenylic acid (Poly A) is a single-strand flexible helix of stacked bases at neutral pH and room temperature. As the temperature is raised the stacking decreases, but there is still perceptible order at 80°C. The thermal transition from the double-strand helix (which exists at low pH) to the single-strand helix has been followed by optical rotatory dispersion, optical absorption, and viscosity measurements.
Teloplasm formation in a leech, Helobdella triserialis, is a microtubule-dependent process.

Fertilized eggs of the leech Helobdella triserialis undergo a cytoplasmic reorganization which generates domains of nonyolky cytoplasm, called teloplasm, at the animal and vegetal poles. The segregation of teloplasm to one cell of the eight-cell embryo is responsible for a unique developmental fate of that cell, i.e., to give rise to segmental ectoderm and mesoderm. We have studied the cytoplasmic movements that generate teloplasm using time-lapse video microscopy; the formation and migration of rings of nonyolky cytoplasm were visualized using transmitted light, while the movements of mitochondria into these rings were monitored with epifluorescence after labeling embryos with rhodamine 123, a fluorescent mitochondrial dye. To examine the likelihood that cytoskeletal elements play a role in the mechanism of teloplasm formation in Helobdella, we examined the distribution of microtubules and microfilaments during the first cell cycle by indirect immunofluorescence and rhodamine-phalloidin labeling, respectively. The cortex of the early embryo contained a network of microtubules many of which were oriented parallel to the cell surface. As teloplasm formation ensued, microtubule networks became concentrated in the animal and the vegetal cortex relative to the equatorial cortex. More extensive microtubule arrays were found within the rings of teloplasm. Actin filaments appeared in the form of narrow rings in the cortex, but these varied apparently randomly from embryo to embryo in terms of number, size, and position. The role of microtubules and microfilaments in teloplasm formation was tested using depolymerizing agents. Teloplasm formation was blocked by microtubule inhibitors, but not by microfilament inhibitors. These results differ significantly from those obtained in embryos of the oligochaete Tubifex hattai, suggesting that the presumably homologous cytoplasmic reorganizations seen in these two annelids have different cytoskeletal dependencies.
Activation and regeneration of rhodopsin in the insect visual cycle

Light absorption by rhodopsin generates metarhodopsin, which activates heterotrimeric guanine nucleotide-binding proteins (G proteins) in photoreceptor cells of vertebrates and invertebrates. In contrast to vertebrate metarhodopsins, most invertebrate metarhodopsins are thermally stable and regenerate rhodopsin by absorption of a second photon. In experiments with Rh1 Drosophila rhodopsin, the thermal stability of metarhodopsin was found not to be an intrinsic property of the visual pigment but a consequence of its interaction with arrestin (49 kilodaltons). The stabilization of metarhodopsin resulted in a large decrease in the efficiency of G protein activation. Light absorption by thermally stable metarhodopsin initially regenerated an inactive rhodopsin-like intermediate, which was subsequently converted in the dark to active rhodopsin. The accumulation of inactive rhodopsin at higher light levels may represent a mechanism for gain regulation in the insect visual cycle.
The little towers of Antwerpen problem

The Little Towers of Antwerpen problem is a simple variant of the Towers of Hanoi problem requiring the interchanging of two stacks (black, white) of N rings using the third tower as a spare, subject to the usual rules governing ring movement. An optimal algorithm for the problem is presented and its performance is analyzed.
Hydrodynamic Model of the Condensation of a Vapor near Its Critical Point

A hydrodynamic model is used to describe the condensation of a supersaturated vapor near its critical point. Calculations are based on a statistical theory of nucleation previously developed by one of the authors (J.S.L.). The method permits careful study of various statistical corrections and a quantitative treatment of the thermal nonaccommodation effect. Although the theory developed here is based on assumptions which are quite different from the classical Becker-D\"oring theory, numerical predictions of the critical supersaturation in Xe and C${\mathrm{O}}_{2}$ turn out to be very nearly the same as the classical results.
Using time-aware memory sensing to address resistance drift issue in multi-level phase change memory

Because of its great scalability potential and support of multi-level per cell storage, phase change memory has become a topic of great current interest. However, recent studies show that structural relaxation effect makes the resistance of phase change material drift over the time, which can severely degrade multi-level phase change memory storage reliability. This paper studies the potential of using a time-aware memory sensing strategy to address this challenge. The basic idea is to keep track of memory content lifetime and, when memory is being read, accordingly adjust the memory sensing configuration to minimize the negative impact of time-dependent resistance drift on memory storage reliability. Because multi-level phase change memory may demand the use of powerful error correction code (ECC) whose decoding can request either hard-decision or soft-decision log-likelihood (LLR) memory sensing, we discuss both hard-decision and soft-decision time-aware memory sensing in details. Using BCH code and LDPC code as ECC for 4-level/cell and 8-level/cell phase change memory, we carry out simulations and the results show that, compared with time-independent static memory sensing, time-aware memory sensing can increase allowable memory content lifetime by several orders of magnitude.
Load Balancing using Grid-based Peer-to-Peer Parallel I/O

In the area of grid computing, there is a growing need to process large amounts of data. To support this trend, we need to develop efficient parallel storage systems that can provide for high performance for data-intensive applications. In order to overcome I/O bottlenecks and to increase I/O parallelism, data streams need to be parallelized at both the application level and the storage device level. In this paper, we propose a novel peer-to-peer (P2P) storage architecture for MPI applications on grid systems. We first present an analytic model of our P2P storage architecture. Next, we describe a profile-guided data allocation algorithm that can increase the degree of I/O parallelism present in the system, as well as to balance I/O in a heterogeneous system. We present results on an actual implementation. Our experimental results show that by partitioning data across all available storage devices and carefully tuning I/O workloads in the grid system, our peer-to-peer scheme can deliver scalable high performance I/O that can address I/O-intensive workloads
A rational approach to anaesthetic premedication.

Rational use of premedication for anaesthesia must always be modified and updated to keep pace with the evolving fields of anaesthesiology and surgery, as well as to meet changing patient needs and preferences. It is no longer axiomatic that all patients require, and therefore should receive, premedication. Unfortunately, a variety of traditional reasons have been proposed to justify routine premedication in many institutions. Smoothing induction, decreasing reflexes and arrhythmias, decreasing nausea and vomiting, decreasing pain, decreasing secretions, and producing sedation and amnesia have all been claimed historically as beneficial results of premedication. Modern anaesthetic agents and techniques have come a long way towards eliminating the routine need for premedication. In the preoperative period, the goal of an anxiety-free patient who is physiologically uncompromised requires an individualised approach based on experience and an adequate knowledge of current pharmacology. As our knowledge of potential problems associated with anaesthesia has expanded, we have added other classes of drugs such as the H2-histamine receptor blockers and antacids to our premedicant armamentarium. Outpatient and short-stay patients have further challenged our preoperative goal of an anxiety-free patient by requiring individuals to be ‘street ready’ within a brief period of time after surgery. Even for in-house elective procedures, not every patient is a candidate for routine premedication. A frank preoperative discussion is all that is necessary to effectively allay anxiety in many persons. In these and other special situations, this article will hopefully guide the reader toward a more rational approach to premedicating patients.
The effects of anesthesia on the biodistribution of drugs in rats: a carboplatin study

Purpose: Anesthetics can alter the biodistribution profile of drugs and, consequently, the regional pharmacokinetics of antineoplastic drugs at the tumor site. The effect of coadministered anesthetics on the biodistribution profile of carboplatin was studied in rats. Methods: Female Wistar rats were used to compare the effects of ketamine/xylazine, thiopental and pentobarbital on the biodistribution of 30 mg/kg radiolabelled 195mPt-carboplatin administered intravenously, with conscious rats as the control group. Blood and urine samples were collected between 5 and 120 min. Results: The percentage values of the injected dose of platinum per ml (%ID/ml) in plasma at the final time-point were respectively, 0.557%, 0.156%, 0.115% and 0.086%, in pentobarbital-, ketamine/xylazine- and thiopental-injected rats, and in conscious animals. Following the same sequence of groups, the %ID/ml values of platinum in the cumulative urine were 0.001%, 0.619%, 0.184% and 0.118%, respectively. Urine output varied from very little in the pentobarbital group, to several milliliters in the other groups. Conclusions: There was an increase of almost 100-fold in total platinum uptake in the kidneys, cerebrum and cerebellum of rats receiving pentobarbital over the uptake in the control rats, whereas the biodistribution profile of the thiopental group had the least variance. These results demonstrate the importance of anesthetic selection in animal pharmacokinetic studies, as it influences the biodistribution and pharmacokinetic profile of the drug being studied.
Computer-aided error modeling approach to improve the accuracy of turning processes

Abstract In this paper, a computer-aided error modeling approach for enhancing the accuracy and the effectiveness of the turning process is discussed. Rigid body kinematics is used to derive error models that correlate the resultant errors in the machine tool workspace to the imperfection and misalignment of positioning elements and workpieces. Using the proposed error modeling technique, the machine tool is capable of fulfilling the major aim of any machining process to produce workpieces within the imposed tolerances of form, dimension, surface finish and quality. The effectiveness of the proposed error modeling approach has been further increased by a computer-aided searching algorithm to identify the robust measuring points with respect to the designated tolerance. For arbitrarily shaped manufacturing parts, the identified measuring points are least sensitive to the potential measuring errors in parameter estimation. The effectiveness of the proposed error modeling approach is demonstrated by simulation results.
Connecting stuttering measurement and management: II. Measures of cognition and affect.

Background: To the person who stutters, there are other experiences than the somatic ones of stuttered speech. These are experiences of cognition and affect: in other words, experiences of thought and emotion. For several reasons, it is quite difficult to determine and recommend core measures of cognition and affect for clinicians to consider using.Aims: To catalogue some of the many instruments that may be regarded by clinicians as worthwhile for use in measuring cognition and affect in clinical practice.Main Contribution: The presentation of measures of cognition and affect is organized according to those that have appeared in recent clinical trials of stuttering during roughly the last decade, and those that have not featured in clinical trials.Conclusions: Measures that have featured in the clinical trials literature might be looked on favourably, along with those for whom there are more than one data source in support. The various measures from the discipline of clinical psychology generally fall int...
Youth purpose among the ‘greatest generation’

Purpose is a stable and generalized intention to accomplish something that is at once important to self and directed at making a difference in the world beyond the self. In the present study, ratings of one aspect of purpose, pro-social beyond-the-self intentions, were gleaned from data collected from young men attending college between 1938 and 1942 as a part of the Study of Adult Development. Associations were examined between pro-social beyond-the-self intentions and childhood environment, and between pro-social beyond-the-self intentions and college and adult personality, psychological adjustment, and achievement. Higher levels of pro-social beyond-the-self intentions were associated with informant ratings of global impressions of positive childhood environment, and with humanistic, political, and well-integrated personality dispositions in college.
A Comparison of Alternative Models for the Demand for Medical Care

We have tested alternative models of the demand for medical care using experimental data. The estimated response of demand to insurance plan is sensitive to the model used. We therefore use a split-sample analysis and find that a model that more closely approximates distributional assumptions and uses a nonparametric retransformation factor performs better in terms of mean squared forecast error. Simpler models are inferior either because they are not robust to outliers (e.g., ANOVA, ANOCOVA), or because they are inconsistent when strong distributional assumptions are violated (e.g., a two-parameter Box-Cox transformation).
Growth-promoting serum proteins for Aedes aegypti cells cultured in vitro.

Abstract The growth-promoting macromolecules in foetal bovine serum (FBS) were studied using Aedes aegypti cells adapted to CSM-2F medium. The non-dialysable portion of FBS retained at least 50 per cent of the growth-promoting activity of FBS. When FBS was subjected to gel filtration, the fractions with high concentration of proteinaceous substances stimulated cell growth. When these protein fractions were subjected to 6 M urea and pronase-digestion treatments, the growth-promoting activity was completely lost. Proteins in precipitate 5, which was isolated by Cohn's cold ethanol method, were growth-promoting. When fresh and 7-day-old cell culture media (CSM-2F) were compared, using disk electrophoresis and a densitometer, it was determined that 13 per cent of the proteins at the albumin region and 67 per cent of the proteins at the fetuin region disappeared from the culture medium after 7 days of cell growth. However, the alpha-globulin, beta-globulin, and lipoprotein fractions isolated from FBS did not promote growth. Among the commercially available isolates of bovine serum proteins tested, only crystallized albumin stimulated growth, but it was found to contain impurities.
Reducing reductionism: on a putative proof for Extreme Haecceitism

Nathan Salmon, in his paper Trans-World Identification and Stipulation (1996) purports to give a proof for the claim that facts concerning trans-world identity cannot be conceptually reduced to general facts. He calls this claim ‘Extreme Haecceitism.’ I argue that his proof is fallacious. However, I also contend that the analysis and ultimate rejection of his proof clarifies the fundamental issues that are at stake in the debate between the reductionist and haecceitist solutions to the problem of trans-world identity. These issues hinge on the ability of modal logic and possible worlds semantics to draw a hard and fast distinction between the logic and the metaphysics of modal logic. I shall claim that the considerations in this paper call into question the viability of such a distinction.
Structural and electrochemical properties of amorphous and crystalline molybdenum oxide aerogels

Abstract The structure and chemical differences among amorphous, crystalline and nanocrystalline molybdenum oxide aerogels were determined using extended X-ray absorption fine structure (EXAFS), Fourier transform infrared (FTIR) analysis and powder X-ray diffraction (XRD). These different forms of the same nominal material are produced by heat treatment. The influence of the structural differences on electrochemical properties was examined using stepped cyclic voltammetry. The most interesting material was the MoO 3 aerogel heated to 300 °C. The material was found to be nanocrystalline; there are no XRD peaks but the EXAFS were virtually identical to orthorhombic MoO 3 . The electrochemcial response of the nanocrystalline material contains characteristics of both the amorphous and crystalline forms, but with better lithium capacity than either one.
Shift-Invariant Optical Associative Memories

Shift invariance in the context of associative memories is discussed. Two optical systems that exhibit shift invariance are described in detail with attention given to the analysis of storage capacities. It is shown that full shift invariance cannot be achieved with systems that employ only linear interconnections to store the associations.
Epithelial cell swelling during incubation of rat small intestine in vitro.

L'augmentation du fluide du tissu de l'intestin grele incube in vitro s'accompagne d'un accroissement du volume des cellules epitheliales.
Comparative toxicity of Prymnesium parvum in inland waters.

Brooks, Bryan W., Susan V. James, Theodore W. Valenti, Jr., Fabiola Urena-Boeck, Carlos Serrano, Jason P. Berninger, Leslie Schwierzke, Laura D. Mydlarz, James P. Grover, and Daniel L. Roelke, 2010. Comparative Toxicity of Prymnesium parvum in Inland Waters. Journal of the American Water Resources Association (JAWRA) 46(1):45-62. DOI: 10.1111/j.1752-1688.2009.00390.x Abstract: Numerous studies have examined the impacts of Prymnesium parvum to aquatic life, but the majority of information available is from experiments or field studies performed at salinities of marine and coastal ecosystems. Ambient toxicity of P. parvum has been characterized with in vitro and in vivo models because reliable quantitation of P. parvum toxins in environmental matrices is often precluded by a lack of available analytical standards. Hemolytic activity and fish mortality assays have been used most frequently to characterize toxic conditions; however, relatively few in vivo studies employed standardized methods. Because the relative sensitivities of different taxa to P. parvum toxins in inland waters were undefined, we assessed the comparative toxicity of P. parvum filtrate from a laboratory study (20°C, 12:12 light:dark cycle, f/8 media, 2.4 psu) to several common standardized in vitro and in vivo models. After exposure to cell-free filtrate hemolytic activity (1 h EC50 = 13,712 cells/ml) and juvenile fish (Pimephales promelas) survival (48 h LC50 = 21,754 cells/ml) were the most sensitive assay responses examined, followed by rotifer (Brachionus calyciflorus) population growth rate [48 h no observable adverse effect levels (NOAEL) = 19,072 cells/ml] and cladoceran (Daphnia magna) reproduction (10-day NOAEL = 47,680 cells/ml). Green algae (Pseudokirchneriella subcapitata) growth (96 h) was not adversely affected but was instead significantly stimulated by P. parvum toxins. We further propose an initial species sensitivity distribution approach for P. parvum, which may be used to support future environmental management decisions. Our findings from these laboratory studies indicate that although fish kills are increasingly associated with P. parvum blooms occurring in inland waters, further study is required to define the influences of toxin sensitivities of phytoplankton, zooplankton, and fish communities on P. parvum bloom initiation and termination.
Long-term retrospective study of patients with idiopathic clubfoot treated with posterior medial-lateral release.

Background: It has been demonstrated that an important component of clubfoot deformity is related to pathologic external rotation of the talus with respect to the remainder of the foot. The purpose of the present study was to review the long-term results for a cohort of patients with idiopathic clubfoot who were managed by a single surgeon with a uniform surgical protocol consisting of extensive posterior medial-lateral release in addition to the use of a temporary Kirschner wire to derotate the talus prior to fixation. Methods: Eighty patients (120 clubfeet) with idiopathic clubfoot without previous surgery were managed with posterior medial-lateral release. At an average of twenty-one years postoperatively, patients underwent a detailed physical examination and completed four quality-of-life surveys (the Short Form-36, the Laaveg and Ponseti scale, the Foot Function Index, and the modified Atar scale). Results: Thirty-two clubfeet (27%) had required additional procedures at the time of follow-up, with only one patient requiring complete revision posterior medial-lateral release and none requiring subtalar or triple arthrodesis. In patients with unilateral clubfoot, clinical examination demonstrated a significant decrease in the range of motion (p < 0.001), foot length (p = 0.045), and calf circumference (p = 0.008) on the affected side as compared with the unaffected, contralateral side. The results on all four quality-of-life scales remained durable, with no decline in relation to the time from the index procedure (p ≥ 0.48). Significantly worse scores were found for patients who required additional surgical procedures (p ≤ 0.03). Conclusions: Previous studies have demonstrated inconsistent long-term results following the treatment of clubfoot with extensive soft-tissue releases. With our technique, thirty-two clubfeet (27%) required additional procedures and only one clubfoot required revision posterior medial-lateral release. We demonstrate that our technique, which involves aggressive posterior medial-lateral soft-tissue release in addition to manual derotation of the talus with a Kirschner wire to correct pathologic external rotation, produces acceptable results. Level of Evidence: Therapeutic Level IV. See Instructions for Authors for a complete description of levels of evidence.
Impact of adenoviruses in human disease.

Abstract Eleven of 33 adenovirus serotypes produce acute disease in man and have their greatest effect in semiclosed populations of military recruits, particularly types 4 and 7. Pediatric adenovirus disease due to types 1, 2, 3, 5, and 7 accounts for a significant proportion of childhood illness but insignificant mortality. Adenovirus infection in military recruits can be markedly reduced by administration of an enteric-coated capsule of live type 4 vaccine which produces a silent infection of the intestinal tract and protects against subsequent respiratory disease. Studies with a similar vaccine against type 7 promise equally effective results.
Plane strain fracture toughness of MP35N in aged and unaged conditions measured using modified CT specimens

Abstract The multiphase alloy MP35N (35% Ni, 35% Co, 10% Mo, 20% Cr) is a high strength, high toughness alloy of choice for several safety-critical applications in aerospace, oil drilling, and biomedical industries. Several previous attempts in literature to measure the plane strain fracture toughness of commercially drawn MP35N did not produce reliable values since they violated one or more of the criteria stipulated by ASTM standards for a valid measurement of K Ic . In most cases, the requirements for plane strain and small scale yielding conditions were not met, since the commercially drawn material was available only with limited cross-sectional dimensions. In this investigation specially designed specimens (modified compact tension (CT) specimens) have been used to measure the plane strain fracture toughness of MP35N in both the unaged and the aged conditions. The K Ic of the commercially drawn (53% reduction level) MP35N was measured to be 126 MPa√m, while that of the commercially drawn and aged MP35N was measured to be 98 MPa√m. Both these measurements satisfied all the required criteria stipulated by ASTM standards for valid measurements of K Ic . The new procedure used in this study has been verified by the measuring of fracture toughness of Al alloy, using both the modified specimen, as designed here, and the standard one. The results for plane strain fracture toughness of MP35N alloy have been verified by the standard measurement of J Ic values for both the aged and the unaged alloys. Finally, on a suitably normalized plot, introduced in this paper, the toughness-strength envelop for MP35 is higher than most of structural alloys, but significantly lower than that of the TRIP steels.
Software Design for Neurocontrol Code

This paper discusses software engineering aspects of neurocontrol algorithm design. Cutting edge algorithm development often outstrips the capability of routinely available software packages. Hence, it is difficult to perform adequate algorithm validation and verification (algorithm V & V). The basic building blocks of a software neurocontroller (data sampling, state prediction and control selection) are developed. The underlying artificial neural architecture used here is the CMAC, although much of the discussion is fairly generic. Code fragments are provided that illus trate implementation details for the CMAC architecture, the sampling of the data stream, local con troller estimates and so forth.
Effect of puromycin on metanephric differentiation: Morphological, autoradiographic and biochemical studies

Effect of puromycin on metanephric differentiation: Morphological, autoradiographic and biochemical studies. Effect of aminonucleoside of puromycin (PAN) on metanephric development and proteoglycans (PGs) was investigated. Murine metanephric tissues, obtained on the thirteenth day of gestation, were exposed to PAN in a culture medium for one to seven days and processed for morphological, histochemical and immunofluorescent studies. For tissue autoradiographic and biochemical studies, kidneys were labelled with a precursor product of PGs, that is, [ 35 S]-sulfate. A generalized decrease in the glomerular population along with swelling and deformation in the ureteric bud branches was observed. These changes were accompanied with a diminution in the total incorporated radioactivity and a reduction in the autoradiographic grains, especially over the tips of ureteric bud branches. Sepharose CL-4B chromatography revealed a major high molecular weight PG (M r > 2.5×10 6 ), and a relative increase in the chondroitinase-ABC sensitive PGs. The media PGs were of relatively smaller size. Immunoprecipitation experiments with [ 35 S]-methionine-labeled tissues and immunofluorescent studies revealed a significant decrease of PGs in metanephric tissues, while type IV collagen and laminin were relatively unaffected. Significant glomerular changes included failure in differentiation of the visceral epithelial foot processes, formation of villi and in maturation of glomerular basement membrane. The latter was seen as fragments of extracellular matrices interspersed among undifferentiated podocytes and had reduced staining with ruthenium red—a dye marker for the PGs. This deficiency of PGs was confirmed by electron microscopic autoradiography, where a reduction in the number of silver grains was observed. The fact that the PAN-induced cellular and extracellular alterations were associated with perturbances in biosynthesis of PGs, suggests that the morphogenetic regulators, that is, PGs play a vital role in various differentiation processes involved during metanephric development.
Dose Gradient Near Target–Normal Structure Interface for Nonisocentric CyberKnife and Isocentric Intensity-Modulated Body Radiotherapy for Prostate Cancer

Purpose The treatment planning quality between nonisocentric CyberKnife (CK) and isocentric intensity modulation treatment was studied for hypofractionated prostate body radiotherapy. In particular, the dose gradient across the target and the critical structures such as the rectum and bladder was characterized. Methods and Materials In the present study, patients treated with CK underwent repeat planning for nine fixed-field intensity-modulated radiotherapy (IMRT) using identical contour sets and dose–volume constraints. To calculate the dose falloff, the clinical target volume contours were expanded 30 mm anteriorly and posteriorly and 50 mm uniformly in other directions for all patients in the CK and IMRT plans. Results We found that all the plans satisfied the dose–volume constraints, with the CK plans showing significantly better conformity than the IMRT plans at a relative greater dose inhomogeneity. The rectal and bladder volumes receiving a low dose were also lower for CK than for IMRT. The average conformity index, the ratio of the prescription isodose volume and clinical target volume, was 1.18 ± 0.08 for the CK plans vs. 1.44 ± 0.11 for the IMRT plans. The average homogeneity index, the ratio of the maximal dose and the prescribed dose to the clinical target volume, was 1.45 ± 0.12 for the CK plans vs. 1.28 ± 0.06 for the IMRT plans. The average percentage of dose falloff was 2.9% ± 0.8%/mm for CK and 3.1% ± 1.0%/mm for IMRT in the anterior direction, 3.8% ± 1.6%/mm for CK and 3.2% ± 1.9%/mm for IMRT in the posterior direction, and 3.6% ± 0.4% for CK and 3.6% ± 0.4% for IMRT in all directions. Conclusion Nonisocentric CK was as capable of producing equivalent fast dose falloff as high-number fixed-field IMRT delivery.
Production and release of N2O from the Potomac Estuary 1

Measurements of dissolved O2, N2O, NH4+, NO2−, and NO3− are used to study the biogeochemistry of nitrogen in the Potomac River near Washington, D.C. The nutrient budget of the Potomac is dominated by sewage inputs from treatment plants at Blue Plains and Alexandria. Measurements taken in July and September 1977 indicate large supersaturated concentrations of N2O and exhibit significant short-period variations over distances >40 km. Concentrations of N2O and O2 appear to be inversely correlated and there are indications that N2O may be produced primarily near the sediment-water interface. Nitrous oxide is released to the air on a time scale of about 1 day and gas exchange may occur mainly in shallow embayments in response to turbulence associated with tidal currents. Release of N2O to the atmosphere takes place at a rate of about 103 kg·d−1 and may be attributed to prompt conversion to N2O of between 1 and 5% of the total nitrogen input.
Microanalysis of non-heme iron in animal tissues.

The method recommended by the Iron Panel of the International Committee for the Standardization in Haematology for measurement of serum iron was adapted for measurement of non-heme iron in animal tissues. The method developed was designed specifically to facilitate measurement of non-heme iron using as little as 10 mg of tissue, in a final reaction volume of 60 μl. In this assay, tissue homogenates are treated with hydrochloric acid and trichloroacetic acid and heated at 95 °C. Non-heme iron is released and protein is precipitated. Following centrifugation, iron in the supernatant is reacted with ferrozine in the presence of the reducing agent thioglycolic acid, and the complex is quantified by spectrophotometry. The method was validated by analysis of two Standard Reference Materials (bovine liver), comparing results of this assay against certified values and concentrations determined by flame atomic absorption spectrometry following acid digestion. Results using this method for analysis of non-heme iron in guinea pig tissues (liver, kidney and heart) compared favorably with those obtained using micro-scale adaptations of three published reference methods. The new method was more sensitive, required less time, and was less cumbersome than the three published methods to which it was compared.
A pulse-chase study tracking the conversion of macrophage-endocytosed serum amyloid A into extracellular amyloid.

Objective To determine whether serum amyloid A (SAA) is internalized by and processed in macrophages en route to deposition as extracellular amyloid. Methods SAA was tracked in cultures of peritoneal macrophages, using a pulse-chase protocol. Macrophages were pulsed with either fluorescently (with Texas Red) tagged SAA (TxR-SAA) or iodinated SAA (125I-SAA). Cells were then rinsed and shifted to chase medium containing unlabeled SAA and amyloid-enhancing factor (AEF) to induce amyloid formation. At selected times, TxR-SAA in living cells was observed by confocal scanning microscopy. 125I-SAA was visualized and quantified in cell lysates and medium by sodium dodecyl sulfate–polyacrylamide gel electrophoresis and phosphorimaging. The presence of amyloid was confirmed by Congo red staining. Results Confocal microscopy immediately after the pulse revealed TxR-SAA in endosomal vesicles, with no extracellular or cell surface accumulation. After 24 hours and 72 hours of chase, virtually all TxR-SAA remained intracellular. By 10 days, extracellular fluorescence was very strong, indicating that SAA had moved out of cells. Congo red staining revealed amyloid colocalized with areas of extracellular fluorescence. Experiments using 125I-SAA showed that while 90–95% of internalized 125I-SAA was degraded within 24 hours, 5–10% persisted as intact SAA or SAA peptides. Immediately after the pulse, SAA was full-length, but within 24 hours, discrete 125I-SAA peptides were seen. Each peptide had an intact SAA amino-terminus, as expected for AA protein. Amyloid was detected in cultures as early as 24 hours after initiation of treatment with SAA and AEF and appeared to be intracellular. Conclusion The results of this study provide direct evidence that SAA internalized by and processed in macrophages forms extracellular amyloid. Based on the presence of 125I-AA protein in macrophage lysates prior to the appearance of extracellular TxR-labeled amyloid, it was concluded that cleavage of SAA to AA occurs intracellularly.
Female sexual dysfunction.

Female sexual dysfunction (FSD) was recently recognized as arising from multiple organic etiologies; it is not primarily a psychological symptom as believed previously. A symptom-related complex resulting in physiologic changes, FSD can respond to either treatment of the underlying condition or supportive measures. A new diagnostic classification allows physicians to perform a clinical evaluation of women with FSD, and recently validated FSD questionnaires allow monitoring of treatment efficacy. This article details the clinical evaluation and physical examination of women with FSD and outlines the fledgling research and treatment options.
SU‐GG‐I‐11: Dose and Image Quality Evaluation of a Mobile CT Scanner for Head and Neck Imaging

Purpose: To evaluate the radiation dose delivered to patients and personnel by a mobile x‐ray CTscanner designed for bedside imaging of the head and neck, and to examine image quality under clinical conditions. Method and Materials:Computed Tomography Dose Index(CTDI) was measured using a 100 mm pencil ionization chamber and 16 cm diameter acrylic phantom over a range of acquisition parameters on a mobile CTscanner (Neurologica Ceretom, Danvers, MA). Scatter radiation was measured using the same phantom. Image quality was evaluated using the manufacturer's QA phantom and the common CATPHAN phantom. Results: At 120 kVp, CTDI‐100 measured 44.8, 83.5, and 122 mGy at 7 mA and 2, 4, and 6 seconds per rotation, respectively. At 140 kVp, commonly used for head scanning, the CTDI‐100 measured 65.3, 126.8, and 176.3 mGy at 7 mA and 2, 4, and 6 seconds per rotation, respectively. All measured doses were within 10% of the CTDI values indicated to the operator on the scanner's console. Using protective lead curtains provided with the scanner, scatter radiation was well within ALARA standards. CATPHAN images demonstrated acceptable alignment, slice width and incrementation accuracy, geometric accuracy, low contrast resolution, high contrast spatial resolution, image uniformity and CT number linearity at clinical techniques. Conclusion: When operated in “low dose” (2 seconds/rotation) mode, the radiation dose delivered by the mobile CTscanner is below or comparable to the ACR's diagnostic Reference Value (RV) for head CT dose. The “standard” (4 seconds/rotation) and “high‐quality” (6 seconds/rotation) modes deliver more radiation, with a corresponding increase in image quality. Assessment using an industry‐standard phantom produced acceptable image quality performance under clinical conditions. With proper precautions, the scanner can be safely used in most intensive care environments without additional shielding, with minimal occupational exposure.
The dichotomy of inhibiting nuclear factor kappa-B in pneumonia

Activation of nuclear factor kappa-B (NF-κB) results in its translocation from the cytoplasm to the nucleus and binding to the promoters of a large number of genes, including those encoding proinflammatory cytokines and other mediators that can contribute to organ system dysfunction in severe infection. While inhibition of NF-κB activation has been proposed as a therapeutic approach in critical illness, several studies have indicated that such an approach may have deleterious effects in persistent infectious states, such as pneumonia. A new report from Devaney and colleagues shows that while inhibition of NF-κB may be useful in severe pneumonia associated with rapid progression to mortality, it leads to worsened pulmonary injury with increased bacterial numbers in the lungs in a model of prolonged pneumonia. Such data raise concerns about therapeutic approaches targeting NF-κB in critically ill patients with persistent infection.
Preliminary performance analysis of breast MRI CAD system

Alan Penn & Associates, Inc. is developing a computer-aided-diagnosis (CAD) system to assist radiologists in distinguishing benign from malignant breast lesions in gadolinium-enhanced magnetic resonance (MR) images. The CAD system uses reader interpretations and computer analysis to generate numeric and visualization aids to help the radiologist make more informed decisions. This paper presents results of analyses that evaluate the statistical and diagnostic effectiveness of the breast-MR CAD system: 1)Evaluation of a first-generation CAD system by five radiologists at the University of Pennsylvania Medical Center (UPMC). 2)Validation of the computer-generated fractal measure using a second set of images. This paper also presents a description of a second-generation system that includes kinetic interpretations.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Engineering cells to improve protein expression

Cellular engineering of bacteria, fungi, insect cells and mammalian cells is a promising methodology to improve recombinant protein production for structural, biochemical, and commercial applications. Increased understanding of the host organism biology has suggested engineering strategies targeting bottlenecks in transcription, translation, protein processing and secretory pathways, as well as cell growth and survival. A combination of metabolic engineering and synthetic biology has been used to improve the properties of cells for protein production, which has resulted in enhanced yields of multiple protein classes.
The Known Unknowns

Securing computer systems is an ongoing task that requires involvement of users, system administrators, and developers. There has been a lot of discussion of embedded computer security in the computer science curriculum, but that is insufficient. It's necessary to provide training to keep workers up to date, and to educate them. In this article, the authors discuss the workforce, and the fact that a majority of those working in computing fields don't have a formal computer science degree. What do they know, and what do employers need to know about the gaps in the employee's knowledge?
Isolation and characterization of X-linked mutants of Drosophila melanogaster which are sensitive to mutagens.

Thirteen X-linked mutants have been isolated in Drosophila melnnogaster which render male and homozygous female larvae sensitive to the mutagen methyl methanesulfonate. Their characterization and preliminary assignment to functional groups is described. Four of these mutants are alleles of mei-41 (BAKER and CARPENTER 1972). Like previously isolated alleles of this locus, these mutants reduce fertility and increase loss and nondisjunction of the Xchromosome in homozygous females. The remaining mutants have been tentatively assigned to six functional groups (two mutants to the mus(1)lOl locus, two to mus(l)l02, two to mus(l)l03, and one each to mus(I)l04, “(1)105, and mus(l)l06). Several of the complementation groups can be distinguished on the basis of nondisjunction and cross sensitivity to mutagens. Females homozygous for the mei-41, mus(1)lOl and mus(l)l02 mutants exhibit elevated levels of nondisjunction. Mutants belonging to complementation groups mei-41, mus(l)lOl, and mus(l)l04 are sensitive to nitrogen mustard (HN2) in addition to their MMS sensitivity. Among these mutants there is currently a direct correlation between sensitivity to HN2, sensitivity to 2acetylaminofluorene and a deficiency in post-replication repair (BOYD and SETLOW 1976). Only the mei-41 mutants are hypersensitive to UV radiation, although several of the mutants exhibit sensitivity to y-rays. Semidominance is observed in female larvae of the mei-41, mus(l)l04, and mus(l)l03 mutants after exposure to high concentrations of MMS. The properties of the mutants generally conform to a pattern which has been established for related mutants in yeast. Additional properties of these mutants are summarized in Table 9. INTENSIVE studies of DNA repair in prokaryotes have revealed the existence of a complex array of mechanisms which are capable of reversing a variety of alterations in the genetic material (see review volumes edited by HANAWALT and SETLOW 1975). Because of the complexity and redundancy associated with these systems, the isolation of repair-deficient mutants has been of paramount importance in defining the various repair pathways and their interrelationships. Parallel genetic studies in fungi have extended this area into the realm of simple eukaryotes (see review by CATCHESIDE 1974). At the alternate end of the eukaryotic spectrum studies of human genetic disorders have provided definitive evidence for the existence of several different repair mechanisms in complex Studies of radiation sensitivity are taken from the Ph D. thesis of T. D NGUYEN.