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There are over 1,000 described neurological and neurodegenerative disorders affecting nearly 100 million Americans - roughly one third of the U.S. population. Collectively, treatment of neurological conditions is estimated to cost $800 billion every year. Lowering this societal burden will require developing better model systems in which to study these diverse disorders. Microphysiological systems are promising tools for modeling healthy and diseased neural tissues to study mechanisms and treatment of neuropathology. One major benefit of microphysiological systems is the ability to incorporate biophysical forces, namely the forces derived from biological fluid flow. Fluid flow in the central nervous system (CNS) is a complex but important element of physiology, and pathologies as diverse as traumatic or ischemic injury, cancer, neurodegenerative disease, and natural aging have all been found to alter flow pathways. In this review, we summarize recent advances in three-dimensional microphysiological systems for studying the biology and therapy of CNS disorders and highlight the ability and growing need to incorporate biological fluid flow in these miniaturized model systems.

Microorganisms express various transmembrane complexes collectively known as efflux pumps that influence their survival under stressful growth conditions. Although efflux pumps are important in resistance to antibiotics, disinfectants, and preservatives, little information about their presence and roles in Cronobacter spp. is available. To better understand the phylogeny, prevalence, and distribution of efflux pumps among strains of Cronobacter spp., whole genome sequencing (WGS) and pan-genomic DNA microarray (MA) analysis were carried out. Targeted MA analysis with 156 probe set alleles representing efflux pump genetic loci showed that all seven Cronobacter species possessed species-specific efflux pump orthologues. Distribution of the efflux pump genes and sequence variations were studied using WGS datasets. Phylogenetic and molecular clock analyses showed that the acquisition of these efflux pump genes possibly occurred at separate evolutionary events, which most likely correlated with the evolution of sequence type (ST) lineages. The acquisition of efflux pump genes either occurred as independent evolutionary events through horizontal gene transfer, or in certain situations, such as that for ST83 and ST4 strains, they could have been acquired through a robust microevolutionary selective process, some of which may have provided functional advantages. Efflux pump activity is very important in osmotic adaptation, survival, and persistence of Cronobacter species and are involved in several important physiological processes including protein, heavy metal, and sugar efflux. Understanding the mechanisms of Cronobacter adaptation in a wide range of environments, could eventually lead to development of methods to control the contamination of foods by these organisms.

Presented is an electronic implementation of a matched filter intended for chaos-based communication systems. While implementing the transmitter side of such systems is relatively trivial, the receiver has proven challenging to develop. Most chaotic systems lack a known fixed basis function, making it difficult to develop a matched filter for them. Instead, their receivers rely on more complicated or less effective techniques to compensate for the presence of noise. However, a previously developed manifold piecewise linear chaotic system has been shown to have an exact analytic solution. This solution has enabled the development of a matched filter for use in any communication system based on this chaotic system. The original communication system operated at a fundamental frequency of 84 Hz, much too low for any practical applications. Therefore, newer communication systems have been designed to operate at higher frequencies. In this work, the performance of this matched filter has been evaluated with a 18.4 kHz chaotic oscillator.

Women are more likely than men to be diagnosed with anxiety disorders and to be prescribed benzodiazepines. People with substance use disorders are at a heightened risk for the misuse of benzodiazepines, yet little is known about sex differences in the prevalence, correlates or patterns of benzodiazepine misuse in this population. The aim of this study was to characterize sex differences in benzodiazepine misuse in a sample of adults receiving substance use disorder treatment (N = 352). Almost half of the sample had been prescribed a benzodiazepine and more than 40% had misused a benzodiazepine. Women were more likely to have a lifetime prescription than men, but were not more likely to report misuse or regular misuse. Consistent with data for other substances, women were more likely to report misusing benzodiazepines to cope and reported greater anxiety sensitivity. The vast majority (97%) of participants reported co-use of benzodiazepines with other substances and 65% of women reporting misusing benzodiazepines via a non-oral route of administration (e.g., intranasal). Although benzodiazepine misuse prevalence was not substantively different between men and women, several sex differences in clinical characteristics and patterns of use were identified. Further research on the nature of sex differences in benzodiazepine misuse is needed to inform targeted treatment for both men and women with substance use disorders.

Cronobacter are opportunistic pathogens, which cause infections in all age groups. To aid the characterization of Cronobacter in foods and environments a harmonized LPS identification scheme for molecular serotyping is needed. To this end, we studied 409 Cronobacter isolates representing the seven Cronobacter species using two previously reported molecular serotyping schemes, described here as Mullane–Jarvis (M–J) and Sun schemes. PCR analysis revealed many overlapping results that were obtained when independently applying the two serotyping schemes. There were complete agreements between the two PCR schemes for Cronobacter sakazakii (Csak) O:1, Csak O:3, and Csak O:7 serotypes. However, only thirty-five of 41 Csak O:4 strains, identified using the M–J scheme, were PCR-positive with the Sun scheme primers. Also the Sun scheme Csak O:5 primers failed to identify this serotype in any of the C . sakazakii strains tested, but did recognize seven Cronobacter turicensis strains, which were identified as Ctur O:3 using the M–J scheme. Similarly, the Sun scheme Csak O:6 primers recognized 30 Cronobacter malonaticus O:2 strains identified with the M–J scheme, but failed to identify this serotype in any C . sakazakii strain investigated. In this report, these findings are summarized and a harmonized molecular-serotyping scheme is proposed which is predicated on the correct identification of Cronobacter species, prior to serotype determination. In summary, fourteen serotypes were identified using the combined protocol, which consists of Csak O:1-O:4, and Csak O:7; Cmal O:1-O:2; Cdub O:1-O:2, Cmuy O:1-O:2, Cuni O:1, as well as Ctur O:1 and Ctur O:3.

Diets high in (n-3) PUFA decrease colon cancer development and suppress colon tumor growth, but the molecular mechanism through which these compounds act is largely unknown. We sought to determine whether PPARgamma1 serves as a molecular link between the physiological actions of eicosapentaenoic acid (EPA) in human colon cancer cells (HT-29). At nutritionally relevant concentrations, EPA stimulated a PPAR response element (PPRE) reporter assay in a dose-responsive manner in HT-29 cells. Cotreatment with GW9662 (GW), a PPARgamma antagonist, significantly inhibited this effect, whereas overexpressing the receptor enhanced it. EPA also stimulated the PPRE reporter in a PPARgamma negative cancer cell line (22Rv1) when the cells were cotransfected with a PPARgamma1 expression plasmid and this effect was again inhibited by GW. Furthermore, in vitro incubation of EPA with PPARgamma1 enhanced binding of the protein to DNA containing a PPRE. Next, we sought to determine whether EPA or a prostaglandin formed from EPA is the functional ligand of PPARgamma. Cotreatment in HT-29 and 22Rv1 cells with EPA and acetyl salicylic acid, an inhibitor of cyclooxygenase activity, activated the PPRE reporter at levels similar to EPA alone, suggesting that EPA itself is a ligand of PPARgamma. Finally, EPA suppressed HT-29 cell growth and this effect was significantly reversed by the addition of GW, suggesting that in part the physiological actions of EPA are the result of PPARgamma activation. These studies identify PPARgamma as a molecular mediator of (n-3) PUFA actions in colon cancer cells.

In bacterial pathogenesis, it is often easy to accept the results of large-scale screens without independent verification of the results. How can one critically read this literature? Here we review issues inherent in genome-wide screens in bacteria, focusing on experiments that attempt to comprehensively identify genes required for bacterial growth under specific conditions. Our analysis suggests that the methodologies employed undoubtedly shape the results. It is clear, however, that the question is not which method is better but which provides the data most suited to a given question.

With the development of new methods to sequence DNA from preserved organisms, existing archival collections can be used to document the population genetic structure of deep-sea species. This has made possible the first direct inferences about patterns of evolutionary diversification in the soft-sediment macrofauna. Here we report protocols and success rates for amplifying and sequencing regions of the mitochondrial 16S rDNA, Cytochrome oxidase I (COI), and Cytochrome b (cytb) genes from formalin-fixed protobranch bivalves and gastropods, major components of the deep-sea benthos. DNA was extracted from 1532 individuals of 12 common bathyal and abyssal species that had been fixed in formalin and preserved in alcohol for up to 36 years. DNA was also extracted from 53 individuals that were dried upon collection, some of which were collected more than 100 years ago. The overall success rate for amplification by PCR was 44%, but this varied considerably among species, stations, and cruises. When DNA amplified, sequencing success was generally high, averaging 85% and ranging from 19% to 100%. The reliability of amplification and sequencing depend strongly on how samples are treated during collection and storage. Amplification success was similar among samples collected from the same station and samples collected on the same cruise. We provide recommendations on strategies for primer design, PCR, and sample selection to improve success rates for genetic analysis of preserved deep-sea organisms. The success rates from different collections, sampling stations, and cruises provide important guidance for selecting material for future genetic work on deep-sea collections examined here.

The critical plane method has proven to be a popular analytical tool for estimating multiaxial fatigue. Based on the strain-life approach to fatigue, the method relies on a cycle counting routine to identify cycles and a damage model to assess damage for each cycle. Researchers have traditionally borrowed cycle counting methods from established uniaxial methods. This work will show how uniaxial rainflow methods are inappropriate for cycle counting on the critical plane. A multiaxial cycle counting method, based on a simple uniaxial rainflow algorithm, is then presented.

It is generally accepted that the biopersistence of a synthetic vitreous fiber (SVF) is an important determinant of its biological activity. Experimental protocols have been developed to measure the biopersistence of an SVF from short-term inhalation experiments with rats. Clearance kinetics of long (>20 microm) fibers (those believed to have greatest biological activity) have been approximated by one- or two-pool models. Several measures or indices of biopersistence have been proposed in the literature of which three, the weighted half-time (WT(1/2)), the time required to clear 90% of long fibers (T(0.9)), and the so-called slow-phase half-time (T(2)), have been investigated in some detail. This paper considers both one- and two-pool models for long fiber clearance, characterizes the properties of these candidate indices of fiber biopersistence, identifies measures with potentially superior statistical properties, suggests possible cutoff values based on the relation between biopersistence and the outcome of chronic bioassays, and offers comments on the selection of efficient experimental designs. This analysis concludes that WT(1/2) and T(0.9) are highly correlated, are efficient predictors of the outcome of chronic bioassays, and have reasonable statistical properties. T(2), although perhaps attractive in principle, suffers from some statistical shortcomings when estimated using present experimental protocols. The WT(1/2) is shown to be directly proportional to the cumulative exposure (fiber days) after the cessation of exposure and also the mean residence time of these fibers in the lung.

We present the concept and design of a liquid scintillator detector for a long-baseline neutrino oscillation experiment. Neutrinos interact in 2.5 cm thick steel plates alternating with 2.0 cm thick planes of liquid scintillator. The scintillator is contained in multicell PVC extrusions containing individual 2 cm×3 cm cells up to 8 m long. Readout of the scintillation light is via wavelength-shifting fibers which transport light to pixellated photodetectors at one end of the cells.

The mechanisms by which synaptic vesicles are transported and primed to fuse with the presynaptic membrane are important to all chemical synapses. Processes of signal transduction that affect vesicular dynamics, such as the second-messenger cascades induced by neuromodulators, are more readily addressed in assessable synaptic preparations of neuromuscular junctions in the crayfish. We assessed the effects of serotonin (5-HT) through the analysis of the latency jitter and the quantal parameters: n and p in the opener muscle of the walking leg in crayfish. There is an increase in the size of the postsynaptic currents due to more vesicles being released. Quantal analysis reveals a presynaptic mechanism by an increase in the number of vesicles being released. Latency measures show more events occur with a short latency in the presence of 5-HT. No effect on the frequency or size of spontaneous release was detected. Thus, the influence of 5-HT is presynaptic, leading to a release of more vesicles at a faster rate.

Recent results from the Front-End electronics of the Detector of Internally Reflected Cerenkov light (DIRC) for the BaBar experiment at SLAC (Stanford, USA) are presented. It measures to better than 1 ns the arrival time of Cerenkov photoelectrons detected in a 11000 phototubes array and their amplitude spectra. It mainly comprises 64-channel DIRC Front-End Boards (DFB) equipped with eight full-custom analog chips performing zero-cross discrimination with 2 mV threshold and pulse shaping, four full-custom digital time to digital chips (TDC) for timing measurements with 500 ps binning and a readout logic selecting hits in the trigger window, and DIRC Crate Controller cards (DCC) serializing the data collected front up to 16 DFBs onto a 1.2 Gb/s optical link. Extensive test results of the pre-production chips are presented, as well as system tests.

Fiber biopersistence as a major mechanism of fiber-induced pathogenicity was investigated. The lung biopersistence of 5 synthetic vitreous fibers (SVFs) and amosite asbestos was evaluated using the rat inhalation model. In contrast to several previous studies, this study examined fibers that dissolve relatively slowly in vitro at pH 7.4. Fisher rats were exposed for 5 days by nose-only inhalation to refractory ceramic fiber (RCF1a), rock (stone) wool (MMVF21), 2 relatively durable special application fiber glasses (MMVF32 or MMVF33), HT stonewool (MMVF34), amosite asbestos, or filtered air. Lung burdens were analyzed during 1 year post-exposure. Fiber aerosols contained 150-230 fibers/cc longer than 20 micrometer (>20 micrometer). On post-exposure Day 1, long-fiber lung burdens for the 6 test fibers were similar (12-16 x 10(5) fibers/lung >20 micrometer). After 1 year, the percentage of fibers >20 micrometer remaining in the lung was 0.04-10% for SVFs but 27% for amosite. Lung clearance weighted half-times (WT1/2) for fibers >20 micrometer were 6 days for MMVF34, 50-80 days for the other 4 SVFs, and >400 days for amosite. This study and 3 previous studies demonstrate a broad range of biopersistences for 19 different SVFs and 2 asbestos types. Ten of these fibers also have been (or are being) tested in chronic inhalation studies; in these studies, the very biopersistent fibers were carcinogenic (amosite, crocidolite, RCF1, MMVF32, and MMVF33), while the more rapidly clearing fibers were not (MMVF10, 11, 21, 22, and 34). These studies demonstrate the importance of biopersistence as an indicator of the potential pathogenicity of a wide range of fiber types.

An analog chip is designed to receive from a PM, through a 50 Ω coaxial cable, signals rising in 3 ns, falling in 8 ns, and to provide: • digital signals for timing purposes, • multiplixed analog output, proportional to the input, for spectral measurements; there are 8 channels per chip with a common gain adjustment for the preamplifier, and individual control for the offset and threshold setting. The discriminator sensitivity is 2 mV. The dynamic range is from 2 to 100 mV. The noise equivalent at the input is ≈100 μV. The RMS time dispersion is less than 550 ps for 3 mV threshold. The shaping amplifier is of bipolar shape with 80 ns peaking time and 2.5 V mean output voltage. The cross talk between channels is less than 2%.

An 8-channel preamplifier-shaper circuit for use with detectors having a capacitance in the range 20–50 pF has been designed in 1.2 μ CMOS AMS technology. The shaper is designed so that the peaking time can be adjusted, by steps, in the range 200 ns–2 μs by simple digital control. The pole-zero cancellation circuit uses an original method of sensing the preamplifier feedback capacitor discharging current and producing an identical current to discharge the capacitance of the pole-zero cancellation circuit. The series noise resistance r s = 415 Ω has been measured (270 Ω of which is the protection resistor). The input capacitance of the preamplifier is 10 pF + the strays of the test box 10 pF for a total of 20 pF. The input PMOS transistor has a gm of 5 mA/V (from simulation) at 210 μA drain current. The cross-talk between channels is less than 1%.

A complex planar mechanism is usually represented by its simplified schematic representation, called the kinematic skeleton, in both synthesis and analysis. Unfortunately, interference between links may not be evident from the kinematic skeleton. This paper presents a computer aided top-down technique to design the geometry of an interference free mechanism. The method is intended to replace intuitive and trial and error link geometry design techniques. The geometric design of the links of a mechanism is initiated after the kinematic skeleton diagram is created using existing synthesis and analysis techniques. The solution to the interference problem is initialized by placing links into different layers. To ensure a link, called a reference link, does not interfere with other links within its layer, the work space of those links with respect to the reference link is generated. The resulting domain, called a “swept area”, establishes an illegal region whose complement identifies the feasible region to place the geometry of the reference link. The new method is demonstrated with an example.

We report a case of iliac stent infection. Nine days after a 24-hour infusion of urokinase and right iliac artery stent deployment, the patient had fever, in addition to severe groin pain and petechiae isolated to the stented limb. The hospital course was complicated by sepsis, adult respiratory distress syndrome, liver dysfunction, and renal insufficiency. Stent removal and iliac/femoral artery resection, as well as an above-knee amputation, were life-saving. Arterial and stent cultures grew Staphylococcus aureus. Stent infection with arterial necrosis is a devastating, rare endovascular complication. Given its potential seriousness, we would recommend the use of prophylactic antibiotics before stent deployment.

A large scale prototype of a liquid argon accordion calorimeter, conceived as a sector of a full LHC Barrel detector and consisting of an electromagnetic and a hadronic section, has been constructed and tested at the CERN SPS with electron and pion beams in the energy range 10-287 GeV. The energy resolution measured for electrons is 10%/square-root E[GeV] with a local constant of 0.2%. Preliminary results on the hadronic section, which for this first exposure had only half of its transverse coverage, look encouraging and show that the calorimeter behaves according to the design figures.

The liquid argon calorimeter of the H 1 detector presently taking data at the HERA ep collider at DESY, Hamburg, is described. The main physics requirements and the most salient design features relevant to this calorimeter are given. The aim to have smooth and hermetic calorimetric coverage over the polar angular range 4° ≤ θ ≤ 154° is achieved by a single liquid argon cryostat containing calorimeter stacks structured in wheels and octants for easy handling. The absorber materials used are lead in the electromagnetic part and stainless steel in the hadronic part. The read-out system is pipelined to reduce the dead time induced by the high trigger rate expected at the HERA collider where consecutive bunches are separated in time by 96 ns. The main elements of the calorimeter, such as the cryostat, with its associated cryogenics, the stack modules, the read-out, calibration and trigger electronics as well as the data acquisition system are described. Performance results from data taken in calibration runs with full size H 1 calorimeter stacks at a CERN test beam, as well as results from data collected with the complete H 1 detector using cosmic rays during the initial phase of ep operations are presented. The observed energy resolutions and linearities are well in agreement with the requirements.

A prototype liquid argon preshower detector with a strip granularity of 2.5 mm has been tested at the CERN SPS in front of a liquid argon Accordion calorimeter. For charged tracks a signal-to-noise ratio of 9.4 and a space resolution of 340 μm were measured; the rejection power against overlapping photons produced in the decay of 50 GeV π 0 's is larger than 3; the precision on

Endometrioid carcinoma is a malignant tumor which microscopically resembles endometrial adenocarcinoma, but arises from extrauterine sites, most commonly the ovary. Although its association with endometriosis has received considerable discussion, it appears that most of the malignant endometrioid tumors arise de novo. We present a case of endometrioid carcinoma which is outstanding for its primary site in the oviduct and for its histologic appearance, which incorporated a close interplay between both stromal and epithelial elements. The neoplasm was found incidentally, when the woman presented with postmenopausal bleeding due to adenomatous hyperplasia of the endometrium. The patient presented with a stage I, grade I tumor which did not invade the wall of the oviduct. Twelve years following a TAH-BSO and postoperative radiation, the tumor recurred, requiring additional surgery and chemotherapy. The patient is currently disease free, 2 years from her recurrence.

An improved centrifugal flyweight mechanism for axially positioning the driving sheave of a continuously-variable V-belt transmission is described. The new mechanism replaces a cam-type flyweight system with a slider-crank linkage-type system. The benefits of the new design include increased life, decreased cost, reduced size and weight, and smoother shift action. A detailed comparison between the cam and linkage systems are provided, and the type synthesis leading to selection of the slider-crank system is described. The slider-crank system was designed using a dedicated computer-aided design program. Several program features found to assist the design process are described, including rapid interactive response, extensive graphical feedback, and a dual-mode user interface. The new drive is currently marketed as the transmission of internal combustion engine-powered golf carts.

The foliage plant Dieffenbachia maculata (Lodd) G. Don ‘Perfection’ was grown with slow-release fertilizer levels from 1120 to 8960 kg N/ha/year (1120 rate = 12 g 19:6:12 per 15 cm pot/year). Height and foliar and root appearances were evaluated and recorded prior to inoculating plants with the fungal pathogen Myrothecium roridum Tode ex. Fries. Plant height increased with fertilizer level up to 2240–3360 kg N/ha/year, but decreased as the rate continued to increase. Foliar quality was primarily quadratic with highest quality plants fertilized at levels ranging from 2240 to 5600 kg N/ha/year. In contrast, root quality was best for plants fertilized at the 1120 and 2240 kg N/ha/year levels, and decreased linearly as fertilizer rate increased. Number of leaf spots increased linearly as fertilizer level increased in four of five tests.

Parathyroid hormone, calcitonin, and prostaglandin E2 activate the adenylate cyclase-cyclic AMP system in fetal-rat calvaria. These agents presumably interact with the tissue at separate receptor sites. When calvaria were preincubated with trypsin, 500 mug/ml for 45 min, the subsequent increase in 3',5'-AMP in response to parathyroid hormone was markedly diminished, whereas the response to calcitonin and prostaglandin E2 were not altered significantly. The effect was attributable to an action of the enzyme on the tissue and not to hydrolysis of the hormone. Similarily, preincubation of calvaria with trypsin prior to homogenization and preparation of a crude plasma membrane fraction decreased PTH-sensitive adenylate-cyclase activity by 58% but did not alter the degree of stimulation of the enzyme in response to calcitonin, prostaglandin E2, or sodium fluoride. These studies support the hypothesis that the actions of parathyroid hormone and calcitonin on bone are mediated through distinct receptor sites, and the receptors for parathyroid hormone can be altered selectively with trypsin.

The effect of bovine growth hormone on adenylate cyclase activity was studied in bovine and rat renal medulla. Highly purified growth hormone (lot B1003A) increased adenylate cyclase activity in plasma membranes from bovine renal medulla from 132 ± 6 pmol cyclic AMP formed/mg protein per 10 min to 364 ± 10 pmol cyclic AMP formed/mg protein per 10 min. Similar results were seen with homogenates of rat renal medulla. The minimum effective concentration of bovine growth hormone required to activate adenylate cyclase was 0.5 μg/ml and maximum activation was detected at 500 μg/ml. The amount of vasopressin determined by radioimmunoassay to contaminate the growth hormone caused an increase in adenylate cyclase activity comparable to that of the corresponding concentration of growth hormone that was tested. Dialysis of growth hormone and vasopressin resulted in parallel reductions in the effect of each hormone on adenylate cyclase activity. Similarly, both growth hormone and vasopressin produced increases in short circuit current in isolated toad bladders but these effects were not detectable after dialysis of the hormones. In contrast, the effect of growth hormone on the uptake of 35SO42− by cartilage from hypophysectomized rats was not decreased after dialysis. These results indicate that available preparations of growth hormone are contaminated by small but physiologically significant amounts of vasopressin and that the activation of adenylate cyclase activity in renal medulla in response to growth hormone can be explained by this contamination rather than by an effect of growth hormone per se.

The effect of age and of dietary restriction on vascular beta-receptor sensitivity was investigated using cultured smooth muscle cells from rat aortas. The growth rate was slower in cells obtained from 36-month-old rats than in cells obtained from 24-mouth-old rats and the cells from older animals achieved lower densities. The dietary restriction did not affect growth of cells from 24-month-old rats but increased cell numbers in 36-month-old rats. The elevation of the cyclic AMP level in response to epinephrine was decreased with age. Cells from dietary restricted animals responded more to epinephrine than cells from animals of the same age fed ad libitum.

BALBc mice immunized with Type III pneumococcal polysaccharide (SIII) had higher numbers of IgM plaque-forming cells (PFC) in the spleen than similarly immunized C57BL/Ks mice. The F 1 hybrids of these two strains had intermediate numbers of SIII-specific PFC. Analysis of the responses of F 2 and backcross strains indicated that the observed responses were compatible with results expected for control of the immune response to SIII at a single autosomal locus.

Expanded boundary divertor discharges in Doublet III have shown a significant enhancement in confinement-relative to limiter discharges with similar plasma density, current, toroidal field and neutral beam heating power. This improvement is insensitive to divertor density, recycling rate and power radiated from the divertor. Accordingly, it may be possible to exploit the improved divertor confinement in a fusion reactor while independently adjusting conditions in the divertor to satisfy reactor engineering constraints.

More than half of elective surgical procedures for aneurysm repair in the United States are performed in hospitals of less than 400 beds, with a 9.4 percent mortality in these hospitals [10]. Recently reported series from larger hospitals have shown an average mortality of 5.8 percent. This survey of an entire state over 7 1 2 years shows a statewide mortality of 11.1 percent for elective aneurysm surgery in 207 elective cases. Surgeons who perform such surgery frequently were significantly more successful than occasional operators. The 9 percent university mortality was related at least in part to infrequent operators. The data recorded by PAS reporting alone was a reasonable approximation of review by other methods. One of the community hospitals with well trained vascular surgeons had good results in both elective and ruptured categories, but other smaller hospitals fared less well. Mortality is related to excessive intraoperative blood loss, frequently caused by venous injury. Advanced age and cardiac disease seem to make patients less able to tolerate such excessive blood loss. Improved mortality data from ruptured aneurysms may be expected with better diagnosis of the presence of aneurysms before rupture and avoidance of delay of surgery after rupture. Stabilization and transfer, or operation in a prepared and equipped hospital where the patient originally presents, both appear to be successful approaches to the treatment of ruptured aneurysms.

A study of airborne Pb, Cd, Zn and Cu was conducted on 2 farms: a test farm exposed to a lead smelter and associated sources of lead contamination in the New Lead Belt of southeast Missouri, and a control farm outside the lead production area. An Andersen eight-stage impactor sampler was used on both farms to collect air samples during winter, spring and summer seasons. The trace element concentrations were measured by atomic absorption spectrophotometry. The concentrations of all four elements were higher on the test farm than on the control farm in all of the three seasons. Approximately 66% of the Pb. 88% of the Cd. 73% of the Zn and 54% of the Cu was composed of particles smaller than 4.7 μm the upper practical limit of respirable size.

Tubular reabsorption of phosphate after release of complete ureteral obstruction in the rat. The excretion of phosphate was studied in rats after release of complete unilateral ureteral obstruction of 24 hours' duration. Marked differences were observed in the rate of excretion of phosphate between the control and the postreleased kidney. After release of unilateral ureteral obstruction, the fractional excretion of phosphate by the control kidney was greater than in normal rats, while the fractional excretion of phosphate by the experimental kidney was markedly decreased. The increased excretion of phosphate by the control kidney was abolished by prior parathyroidectomy and was attributed to an increase in the concentration of circulating parathyroid hormone. The low urinary excretion of phosphate by the experimental kidney could not be attributed to refractoriness of the renal tubule to the action of parathyroid hormone or to changes in the intrinsic capacity of the tubule to reabsorb phosphate. A marked decrease in the filtered load of phosphate is the most likely factor responsible for the low phosphate excretion by the experimental kidney. Support for this concept was obtained from studies in rats in which the filtered load of phosphate was decreased unilaterally by partially constricting the aorta proximal to the left renal artery. In these rats the fractional excretion of phosphate was considerably less in the constricted than in the contralateral normal kidney both before and after the administration of exogenous parathyroid hormone. In addition, a marked dissociation was observed between the rate of excretion of salt and water and the rate of excretion of phosphate in rats studied after release of unilateral ureteral ligation. Fractional excretion of sodium and water was greater in the experimental than in the control kidney whereas fractional excretion of phosphate was greater in the control than in the experimental kidney. These findings are consistent with the hypothesis that in the postobstructed kidney there is increased phosphate reabsorption in the proximal tubule and decreased sodium and water reabsorption in the distal tubule. Reabsorption tubulaire des phosphates apres levee d'une occlusion complete de l'uretere chez le rat. L'excretion des phosphates a ete etudiee chez rats apres levee d'une occlusion unilaterale de l'uretere pendant 24 heures. Des differences importantes ont ete observees dans les debits d'excretion de phosphate entre le renin controle et le renin libere. Apres la levee de l'occlusion unilaterale l'excretion fractionnelle des phosphates par le rein controle est plus grande que chez l'animal normal, alors qu'elle est tres diminuee du cote experimental. L'augmentation de l'excretion des phosphates par le rein controle est abolie par une parathyroidectomie prealable et elle est attribuee a une augmentation de la concentration circulante d'hormone parathyroidienne. L'excretion de phosphates faible par le rein experimental ne peut pas etre mise au compte d'une insensibilite du tube renal a l'action de l'hormone parathyroidienne ou de modifications de la capacite intrinseque du tube a reabsorber les phosphates. Une diminution importante de la charge filtree de phosphates est plus probablement le facteur responsable de la diminution de l'excretion de phosphates par le rein experimental. Des arguments en faveur de cette hypothese ont ete obtenus par l'etude de rats dont la charge de phosphates filtres a ete diminuee unilateralement par une constriction partielle de l'aorte en amont de l'artere renale gauche. Chez ces rats l'excretion fractionnelle de phosphates est tres inferieure du cote subissant la constriction a ce qu'elle est par le rein normal controlateral, aussi bien avant qu'apres l'administration d'hormone parathyroidienne. De surcroit, une dissociation nette a ete observee entre le debit d'excretion de sel et d'eau et le debit d'excretion de phosphates chez les rats etudies apres l'ablation de la ligature ureterale. L'excretion fractionnelle de sodium et d'eau est plus grande par le rein experimental que par le rein temoin alors que l'excretion fractionnelle de phosphates est plus grande par le rein controle que par le rein experimental. Ces constatations sont compatibles avec l'hypothese d'une reabsorption proximale de phosphate accrue et d'une reabsorption distale d'eau et de sodium diminuee dans le rein qui a subi l'obstruction.

Analysis of the expanded boundary divertor in Doublet III reveals a medium density operating regime ( n e ≲ 4 × 10 13 cm -3 ), in which (1) the divertor density ne(Div) rises with the cube of the main plasma line average density, n e , and (2) the neutral pressure at the exhaust end of the divertor has a quadratic dependence on n e (with divertor plasma temperatures ≲ 15 eV). In this regime, injection of argon into the discharge results in a steady state concentration of argon, which is two orders of magnitude higher in the divertor plasma than in the main discharge. This trapping effect suggests that the argon concentration in the divertor region may be useful as an externally controllable parameter; that is, injected argon effectively cools the plasma boundary, yet is not deleterious to the plasma as a whole. A model which successfully describes the behavior of the edge and divertor plasmas in ohmically heated discharges suggests that these desirable trapping and radiative features may be maintained in the high powered neutral beam heating phase.

Adenosine 3',5'-monophosphate (3',5'-AMP) was assayed in calvaria isolated from fetal rats at term. A marked increase in 3',5'-AMP was detected in vitro within 1 min after adding purified parathyroid hormone to calvaria incubated in Krebs-Ringer-bicarbonate or Krebs-Ringer-Tris buffer. A maximal effect was detected after 5 min of incubation with added parathyroid hormone. The lowest concentration of parathyroid hormone causing a significant effect was 0.05 µg per ml or 5 x 10-9 m. The response was a direct function of the log concentration of parathyroid hormone from 0.1 to 1.0 µg per ml, became maximal at 10 µg per ml, did not require potassium, magnesium, or calcium in the incubation medium, and was not inhibited by a high (5 mm) concentration of calcium. Epinephrine and prostaglandins E1 and E2 also caused a significant increase in skeletal 3',5'-AMP. The effect of epinephrine was abolished by propranolol, but this β-adrenergic blocking agent did not affect the response to the prostaglandins or to parathyroid hormone; phentolamine did not affect the response to any of these substances. Calcitonin caused a slight increase in skeletal 3',5'-AMP, but the maximal effect was small and the response was not related to the concentration of polypeptide. Only the effect of parathyroid hormone was clearly relatable to direct hormonal activation of adenyl cyclase in the tissue. Neither thyrotropin, corticotropin, glucagon, insulin, luteinizing hormone, growth hormone, adenosine 5'-monophosphate, guanosine 3',5'-monophosphate, 25-hydroxycholecalciferol, nor sodium fluoride affected the concentration of 3',5'-AMP in this test system. These findings provide further evidence that the physiological actions of parathyroid hormone are mediated by 3',5'-AMP.