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Estuaries are recognized as one of the habitats most vulnerable to coastal ocean acidification due to seasonal extremes and prolonged duration of acidified conditions. This is combined with co-occurring environmental stressors such as increased temperature and low dissolved oxygen. Despite this, evidence of biological impacts of ocean acidification in estuarine habitats is largely lacking. By combining physical, biogeochemical, and biological time-series observations over relevant seasonal-to-interannual time scales, this study is the first to describe both the spatial and temporal variation of biological response in the pteropod Limacina helicina to estuarine acidification in association with other stressors. Using clustering and principal component analyses, sampling sites were grouped according to their distribution of physical and biogeochemical variables over space and time. This identified the most exposed habitats and time intervals corresponding to the most severe negative biological impacts across three seasons and three years. We developed a cumulative stress index as a means of integrating spatial-temporal OA variation over the organismal life history. Our findings show that over the 2014-2016 study period, the severity of low aragonite saturation state combined with the duration of exposure contributed to overall cumulative stress and resulted in severe shell dissolution. Seasonally-variable estuaries such as the Salish Sea (Washington, U.S.A.) predispose sensitive organisms to more severe acidified conditions than those of coastal and open-ocean habitats, yet the sensitive organisms persist. We suggest potential environmental factors and compensatory mechanisms that allow pelagic calcifiers to inhabit less favorable habitats and partially offset associated stressors, for instance through food supply, increased temperature, and adaptation of their life history. The novel metric of cumulative stress developed here can be applied to other estuarine environments with similar physical and chemical dynamics, providing a new tool for monitoring biological response in estuaries under pressure from accelerating global change.

This paper reviews and discusses the rated strength of insulators as defined in ANSI, CSA, and IEC product standards. The definition of rated strength, which for a particular insulator, requires reference to the tests and acceptance requirements given in the appropriate standard for that insulator is discussed. An insulator may not exhibit noticeable changes at loads sufficient for the initiation of irreversible damage, referred to as its damage limit. The significance of this is discussed in the paper as insulator application loads which must be below the damage limit of the insulator and be made in accordance with the relevant standard, including consideration of the allowable variation in strength implied by strict conformance to the standard. Damage limits for ceramic and composite insulators based on the minimum allowable strength according to the current standards are given.

This paper reviews and discusses the mechanical loads that overhead lines experience as defined by applicable codes and the strength requirements for insulators that support the lines as described in ANSI, CSA, and IEC standards. Consideration of the probable occurrence of extreme weather conditions requires the insulator strength to be such that irreversible damage to the insulator does not occur at the maximum load considered. The inherent variation of the mechanical strength of the insulator dielectric material is discussed as a factor for its ultimate strength, and as a basis for limiting line loads below the damage limit for the insulator. Time-load tests suggest that reasonable damage limits for ceramic and composite insulator dielectric materials can be established. As discussed in a companion paper, the assignment of damage limits for specific insulators depends not only on the inherent mechanical strength of the dielectric, but also on the standard upon which the mechanical strength of the insulator is rated. Common line design requirements, coupled with insulator manufacturers' recommendations that the maximum load not exceed the routine proof test load each insulator is subjected to has, in general, given good field experience.

Deceptive fitness landscapes are a growing concern for the field of evolutionary computation. Recent work has demonstrated that incorporating human insights with short-term automated evolution has a synergistic effect that eases deception and accelerates the discovery of solutions. While human evaluators provide rich insight into a domain, they fatigue easily. Previous work reduced the number of human evaluations by evolving a diverse set of candidates via intermittent searches for novelty. While successful at evolving solutions for a deceptive maze domain, it lacked the ability to measure solution qualities that the human evaluator implicitly identified as important. The key insights of this paper are that multi-objective evolutionary algorithms (MOEAs) foster diversity and that the non-dominated set can serve as a surrogate for novelty while measuring user preferences data. This new approach, called Pareto Optimality-Assisted Interactive Evolutionary Computation (POA-IEC), leverages human intuitions by allowing users to identify candidates in the non-dominated set that they feel are promising. Interestingly, the experimental results demonstrate that POA-IEC finds solutions in significantly fewer evaluations than previous approaches, and that the non-dominated set contains significantly more novel behaviors than the dominated set. In this way, POA-IEC simultaneously leverages human insights while quantifying their preferences.

Batrachochytrium salamandrivorans (Bsal) is an emerging fungal pathogen that has caused recent die-offs of native salamanders in Europe and is known to be lethal to at least some North American species in laboratory trials [1]. Bsal appears to have originated in Asia, and may have been introduced by humans into wild populations in Europe through commercial trade of amphibians [1]. Since the first outbreaks of Bsal in the Netherlands, it has been the etiologic agent of mortality events in Belgium (wild) and Germany (captivity), and was recently found in imported salamanders in the United Kingdom [1–4]. Substantial concern has been raised about the associated risk of Bsal to native salamanders in North America [5]. Herein, we review what policy actions are occurring in North America and elsewhere, and call for creation of a North American Bsal Strategic Plan.

In locations exposed to freezing conditions over the station service life, additional measures for selecting adequate station insulators at distribution and transmission voltage levels should be taken. This second part of the paper describes the selection process and mitigation options, based on the environmental parameters, as discussed in Part I. These include insulator size, shape, surface material, surface quality, electric field improvement, and orientation.

In selecting adequate insulators for substations at distribution and transmission voltage levels, special measures may be needed in locations exposed to freezing conditions. This first part of the paper describes the environmental and insulator parameters that influence the risk of flashover on station insulators exposed to freezing conditions.

Background. Ehrlichiosis is a recently described zoonotic infection with two major expressions: human granulocytic ehrlichiosis (HGE) and human monocytic ehrlichiosis (HME). The organisms associated with HGE and HME have been detected in a tick vector in several regions of United States and cases of ehrlichiosis have been reported in the general population. Methods. We report a case of HGE in a renal allograft recipient and review the clinical spectrum of disease in solid organ transplant recipients and the epidemiological basis for risk. Results. Our patient demonstrated the typical epidemiological, clinical and laboratory features of human granulocytic ehrlichiosis and responded to treatment with doxycycline. Conclusions. Human ehrlichiosis should be considered in the differential diagnosis of patients with solid organ transplants, who present with fever and thrombocytopenia. The incidence of ehrlichiosis in the solid organ transplant population is similar to that in the United States general population. As reported in immunocompetent patients, prompt diagnosis and treatment results in the rapid resolution of symptoms in transplanted individuals.

A graphical method of analysis applicable to ligands that bind reversibly to receptors or enzymes requiring the simultaneous measurement of plasma and tissue radioactivities for multiple times after the injection of a radiolabeled tracer is presented. It is shown that there is a time t† after which a plot of f t0ROI( t') dt'/ROI( t) versus f t0 Cp( t') dt'/ROI( t) (where ROI and Cp are functions of time describing the variation of tissue radioactivity and plasma radioactivity, respectively) is linear with a slope that corresponds to the steady-state space of the ligand plus the plasma volume, Vp. For a two-compartment model, the slope is given by λ + Vp, where λ is the partition coefficient and the intercept is −1/[ k2(1 + Vp/λ)]. For a three-compartment model, the slope is λ(1 + Bmax/ Kd) + Vp and the intercept is −{(1 + Bmax/ Kd)/ k2 + [ koff(1 + Kd/ Bmax)]−1} [1 + Vp/λ(1 + Bmax/ Kd)]−1 (where Bmax represents the concentration of ligand binding sites and Kd the equilibrium dissociation constant of the ligand–binding site complex, koff ( k4) the ligand–binding site dissociation constant, and k2 is the transfer constant from tissue to plasma). This graphical method provides the ratio Bmax/ Kd from the slope for comparison with in vitro measures of the same parameter. It also provides an easy, rapid method for comparison of the reproducibility of repeated measures in a single subject, for longitudinal or drug intervention protocols, or for comparing experimental results between subjects. Although the linearity of this plot holds when ROI/ Cp is constant, it can be shown that, for many systems, linearity is effectively reached some time before this. This analysis has been applied to data from [ N-methyl-11C]-(–)-cocaine ([11C]cocaine) studies in normal human volunteers and the results are compared to the standard nonlinear least-squares analysis. The calculated value of Bmax/ Kd for the high-affinity binding site for cocaine is 0.62 ± 0.20, in agreement with literature values.

To assess the effects of chronic cocaine intoxication on dopamine receptors in human subjects, the authors evaluated [18F]N-methylspiroperidol binding using positron emission tomography in 10 cocaine abusers and 10 normal control subjects. Cocaine abusers who had been detoxified for 1 week or less showed significantly lower values for uptake of [18F]N-methylspiroperidol in striatum than the normal subjects, whereas the cocaine abusers who had been detoxified for 1 month showed values comparable to those obtained from normal subjects. The authors conclude that postsynaptic dopamine receptor availability decreases with chronic cocaine abuse but may recover after a drug-free interval.

The purpose of this project is to assess the competitive position of the Naval Aviation Depot at North Island (NADEP North Island) within the defense aircraft repair and re-work industry and offer recommendations for an external marketing plan that will reduce threats to the organization and enhance its competitive position. This project was conducted with the assistance of NADEP North Island. The goals of this project are to assess the competitive position of NADEP North Island, to identify threats to the organization, and then to offer recommendations for external organizational marketing that will reduce or mitigate these threats to the organization. The organizational marketing campaign should serve to strengthen external stakeholder interest in NADEP North Island, thereby reducing threats to the organization and increasing its competitive position in today's unique defense environment.

We studied the time course of changes in the Hahn spin-echo decay (Hahn-T2) in lungs of spontaneously breathing living rats at 1 hour, 3 hours, and 7 days following oleic acid injection. Motion artifacts were minimized by using the motion-insensitive interleaved rapid line scan (ILS) imaging technique. Prior to injury, the lungs exhibited two resolvable exponential Hahn-T2 components. One and 3 hours after injury the decay showed a regionally nonuniform behavior, which was fit with one, two, or three exponential components. The short and medium components increased at 1 and 3 hours after injection. The third, much longer, component is probably due to intraalveolar pulmonary edema. After 7 days the Hahn decay was similar to that observed before injury, probably reflecting resolution of the edema. Our data suggest that Hahn-T2 measurements can be used to characterize the time course and regional distribution of lung injury in living animals.

Our experience with 11C-putrescine underscores the difficulty of finding a selective brain tumor tracer, uniquely incorporated by neoplastic glia or metastatic cells within brain, but not by the proliferating, nontransformed cells which constitute a normal pathophysiological reaction to various disease processes. Thirty-three patients with 36 lesions were studied with 11C-putrescine to determine the specificity of labeled putrescine for tumor tissue. The uptake of 11C-putrescine was correlated with local cerebral glucose metabolic rate in various lesions, including different types of tumors, to assess the relationship between 11C-putrescine uptake and tumor biology. Carbon-11-putrescine uptake was similar in malignant tumor and benign, non-neoplastic lesions with blood-brain barrier breakdown, illustrating the lack of tumor specificity of this tracer. Carbon-11-putrescine was not well incorporated into poorly enhancing lesions, regardless of their pathology, emphasizing the requirement of a disrupted blood-brain barrier for 11C-putrescine uptake. The ratio of 11C concentration within lesions, compared to that in a region of interest in the contralateral brain, weakly correlated with an analogous ratio for local cerebral glucose metabolic rate in various lesions. Physiological processes not unique to tumors are associated with polyamine active transport and metabolism and contribute to the lack of tumor specificity of 11C-putrescine. Carbon-11-putrescine appear to have less diagnostic utility than 18FDG in brain tumors. The potential of 11C-putrescine for evaluating the effect of antineoplastic therapy and providing prognostic information on brain tumors remains to be investigated.

To evaluate the effects of ethanol in the human brain, we tested six normal subjects and six alcoholics using positron emission tomography and 2-deoxy-2-[18F]-fluoro-D-glucose (FDG) under baseline conditions and 24 hours later after ethanol administration (1 g/kg). Ethanol inhibited cortical and cerebellar glucose metabolism with relative sparing of the basal ganglia and corpus callosum. This inhibition was more pronounced in the alcoholics than in the controls. Measurement of the constants for glucose transport and utilization showed that decreased glucose metabolism was due to a reduction in glucose phosphorylation and not to a change of glucose transport into the tissue. The pattern of regional metabolic inhibition by alcohol paralleled the distribution of benzodiazepine receptors in the human brain.

BACKGROUND/OBJECTIVES: A 29-bed long-term acute care hospital (LTCH) that cares for critically ill, but medically stable patients requiring hospitalization for 25 days or more is located in a large tertiary-care hospital. The patient population at LTCH is dominated by those requiring mechanical ventilation and those with debilitating illness requiring a central line for intravenous therapy. Peripherally inserted central catheters (PICC) are the preferred type of intravenous access. For as many as 40%-70% of our patients, their condition is compromised by a previously occurring infection. It is not uncommon for such debilitated patients to carry a combination of two or more resistant organisms necessitating isolation. Most patients arrive with previously inserted central lines. Nearly 75% of the patients arrive with a PICC in place. The other 25% have a PICC inserted near the time of admission. The PICC team is a contracted resource to LTCH. We do not have any control over the insertion procedure, the brand of central lines, the products used for prepping, or the initial dressing used for insertion site. These limitations truly restricted our options and forced us to use our most creative and analytic resources to determine an effective strategy to decrease our bloodstream infection (BSI) rate. After researching the products available on the market for our use, we decided to use a dressing at the insertion site that was impregnated with chlorohexidine gluconate (CHG). METHODS: The Centers for Disease Control and Prevention (CDC) definitions for primary center venous catheter (CVC)-healthcare-associated infections (HAIs) were used. During April 2003, the staff participated in a mandatory inservice on aseptic dressing technique and proper placement of the CHG dressing within 24 hours of admission. RESULTS: The BSI rate for January-December 2002 was 4.4/1000 CVC days. The BSI rate for January-December 2003 was 1.21/1000 CVC days, a decrease of 72.5% from previous year. The BSI rate for January-September 2004 was 1.05/100 CVC days, a decrease of 76% since project start and a 16% decrease from the previous year. CONCLUSIONS: The implementation of CHG-impregnated dressing on the PICC site within 24 hours of admission along with the educational interventions on aseptic technique and policy changes successfully lowered the CVC-associated BSI rate in LTCH.

The regional distributions of monoamine oxidase (MAO) types A and B have been identified in human brain in vivo with intravenously injected 11C-labeled suicide enzyme inactivators, clorgyline and L-deprenyl, and positron emission tomography. The rapid brain uptake and retention of radioactivity for both 11C tracers indicated irreversible trapping. The anatomical distribution of 11C paralleled the distribution of MAO A and MAO B in human brain in autopsy material. The corpus striatum, thalamus, and brainstem contained high MAO activity. The magnitudes of uptake of both [11C]clorgyline and L-[11C]deprenyl were markedly reduced in one subject treated with the antidepressant MAO inhibitor phenelzine. A comparison of the brain uptake and retention of the 11C-labeled inactive (D-) and active (L-) enantiomers of deprenyl showed rapid clearance of the inactive enantiomer and retention of the active enantiomer within MAO B-rich brain structures, in agreement with the known stereoselectivity of MAO B for L-deprenyl. Prior treatment with unlabeled L-deprenyl prevented retention of L-[11C]deprenyl. Thus, suicide enzyme inactivators labeled with positron emitters can be used to quantitate the distribution and kinetic characteristics of MAO in human brain structures.

(18)F-2-deoxy-2-fluoro-D-glucose ((18)FDG) is a positron emitting tracer for rate of glucose utilization in brain. When used in conjunction with positron emission tomography (PET), the PET-FDG technique permits in vivo quantitation of regional brain metabolism in man. We have applied this technique to the study of regional brain function in normal aging and senile dementia. Preliminary results for 7 patients with senile dementia of the Alzheimer's type (SDAT) and 3 elderly normal subjects indicated a large, statistically significant (p < 0.01) diminution in rate of glucose utilization in SDAT. Furthermore, the degree of diminution in metabolic activity in SDAT was highly correlated with objective measures of degree of cognitive impairment. These results demonstrate the feasibility and potential utility of the PET-FDG technique for studying regional brain function in normal aging and dementia.

Microvessels isolated from temporal of cortex of patients with Alzheimer's disease showed decreased uptake of glucose when compared with vessels from age-matched or young control subjects. This was due to decreased hexokinase activity in the Alzheimer samples, as determined by ion exchange chromatography. This finding was confirmed independently by determination of the phosphorylation constant for hexokinase, K3, using positron emission tomography. The results suggest that Alzheimer's disease may result from a global defect in brain energy metabolism.

Using PET VI and 11-CDG we replicated our earlier PET III and 18-FDG normal aging findings. Examination of young and old normal volunteers revealed the absence of any absolute regional age-related changes in glucose utilization. For the combined sample ( N =81) we did find evidence to suggest a relative hypofrontal change with increasing age. A strong relationship between age and ventricular size (CT) was also found. These findings suggest the preserved glucose metabolism of the resting aging brain in the presence of structural atrophic changes.

The preparation of nitrogen-13 labelled α-methylphenyl-ethylamine (amphetamine), utilizing a sealed reaction system is described.

The relationship between alterations in brain structure and brain function was studied in vivo in both young and elderly human subjects. Computed tomography revealed significant age-related ventricular and cortical sulcal dilatation. The cortical changes were most closely related to age. Positron emission tomography failed to show regional changes in brain glucose metabolic rate. The results suggest that the normal aging brain undergoes structural atrophic changes without incurring regional metabolic changes. Examination of the correlations between the structural and the metabolic measures revealed no significant relationships. These data are discussed with respect to the significant structure-function relationships that have been reported in Alzheimer disease.

The efficacy of using the 18 F-fluoro-deoxyglucose ( 18 F-DG) for measuring regional cerebral glucose utilization in man during functional activation is demonstrated. Normal male volunteers subjected to sensory stimuli (visual, auditory, tactile) exhibited focal increases in glucose metabolism in response to the stimulus. Unilateral visual hemifield stimulation caused the contralateral striate cortex to become more active metabolically than the striate cortex ipsilateral to the stimulated hemifield. Similarly, stroking of the fingers and hand of one arm with a brush produced an increase in metabolism in the contralateral postcentral gyrus compared to the homologous ipsilateral region. The auditory stimulus, which consisted of monaural listening to either a meaningful or nonmeaningful story, caused an increase in glucose metabolism in the right temporal cortex independent of which ear was stimulated. These results demonstrat that the 18 F-DG technique is capable of providing functional maps in vivo in the human brain.

Six patients with chronic schizophrenia were studied with positron emission tomography (PET) before and after neuroleptic treatment, using fluorine-18-labeled fluorodeoxyglucose. After treatment, the mean whole-slice glucose metabolic rate at the level of the basal ganglia showed a 25% increase. However, patterns of frontal hypometabolism observed with the schizophrenic patients were not altered by medication. Pattern analysis using the fast Fourier transform was applied to a set of 422 images from a mixed group of normal, depressed, and schizophrenic subjects. Reconstruction of the images with low-frequency coefficients was excellent, reducing considerably the number of variables needed to characterize each image. Hierarchical cluster analysis categorized the transformed images according to anatomical level and subject group (patient versus control). The results suggest the utility of this procedure for the classification and characterization of metabolic PET images from psychiatric patients.

The use of N2O2 or N2H2 pressurized gaseous systems as targets in proton bombardment makes use of the 14 N(p,α) 11 C reaction and allows the facile, quantitative production of H11CN, 11CO2, 11CO or 11CH4 as needed. A system is described for the production of “carrier-free”, high activity (up to 2 Ci) H11CN in an on-line process in the effluent gas stream from a cyclotron target. The target gas is a mixture of 94·5% nitrogen, 5·5% hdrogen, run at a total pressure of 11 atmospheres. The primary products are converted to 11CH4 in over 95 per cent yield by radiolysis in the target, and this, along with NH3 which is concurrently produced radiolytically, is converted quantitatively to “carrier-free” H11CN over platinum wire held at 1000°C. The radiation processes and dosimetry studies involved in the system are discussed. The product is available for use as gaseous H11CN, or in base or carrier sodium cyanide, within 10–12 min after the end of an irradiation. It has been used as such in animal studies and also in the production of carrier-free dopamine-11C and norepinephrine-11C at levels up to 30 mCi at the time of delivery for medical use. An identical target, using tank N2 with trace O2 impurity as the target gas, can be used to produce “carrier-free” 11CO2 at similar activity levels, and from this 11CO or 11CH4 can be made either on-line or by a rapid catalytic reduction.

Positron emission tomography with 11C-2-deoxyglucose was used to determine the test-retest variability of regional cerebral glucose metabolism in 22 young normal right-handed men scanned twice in a 24-h period under baseline (resting) conditions. To assess the effects of scan order and time of day on variability, 12 subjects were scanned in the morning and afternoon of the same day (a.m.-p.m.) and 10 in the reverse order (p.m.-a.m.) with a night in between. The effect of anxiety on metabolism was also assessed. Seventy-three percent of the total subject group showed changes in whole brain metabolism from the first to the second measurement of 10% or less, with comparable changes in various cortical and subcortical regions. When a scaling factor was used to equate the whole brain metabolism in the two scans for each individual, the resulting average regional changes for each group were no mote than 1%. This suggests that the proportion of the whole brain metabolism utilized regionally is stable in a group of subjects over time. Both groups of subjects had lower morning than afternoon metabolism, but the differences were slight in the p.m.-a.m. group. One measure of anxiety (pulse at fun 1) was correlated with run 1 metabolism and with the percentage of change from run 1 to run 2. No significant run 2 correlations were observed. This is the first study to measure test-retest variability in cerebral glucose metabolism in a large sample of young normal subjects. It demonstrates that the deoxyglucose method yields low Intrasubject variability and high stability over a 24-h period.

Heparin has been labeled with tritium by exposing it to tritium gas under an electric discharge or to tritiated water in presence of palladium black. The tritium label is stable under a variety of conditions, and, at least in the heparin labeled by catalytic exchange, is equally distributed between hexosamine and hexuronic acid moieties. Tritium-labeled heparin has also been labeled with 35 S by replacing some N -sulfate groups with similar groups labeled with 35 S. The final products retain the original physicochemical and biological properties, and appear to be suitable for metabolic experiments.

Meteoroid hazard to spacecraft materials and structures, using particle-projection techniques

The four specific ring hydrogen-labeled nicotinic acids were prepared and fed to tobacco root cultures In sterile media. then the nicotine produced by the roots was Isolated and analyzed. Recoil tritium and carbon-14 labeled nlcotinic acid were similarly employed. The nicotine from all of these except nicotinic acid-6-t show similar and substantial incorroration into the nicotine. Oxidation of nicotinic acid. obtained from the nlcotlne. to the corresponding 2- and 6-pyridones indicate that the position of hydrogen label is conserved during the conversion to nicotine. The 6-labeled acid gave less than 10% of the amount of incorporation shown by the other acids Indicatlng the probablllty of enzymatic attack on the 6-position of nicotinic acid dur ing Its conversion to nicotine by the tobacco roots. The conversion probably does not proceed via oxidation at the 6-position, since both 6-hydroxynicotinic acid-N/sup 15/ and 1methyl-6- oxynicotinamide-2-t failed to be Incorporated. The possibility that the acid is incorporated into nicotine via a 1,6-dinydro intermediate is being investigated. Nicotinartide is incorporated to at least as great an extent as is the corresponding labeled acid. (auth)

A series of steps involving the loss and subsequent recapture of carbon monowde is suggested to account for the carboxyl group transfer characteristic of the cinenic acid rearrangement (I yields II). This reaction sequence is compatible with earlier observations. and can be supported by analogies at every stage. The participation of carbon monoxide is indicated by an experiment in which the rearrangement, carried out in the presence of excess carbon monoxide, gave a significantly increased yield of geronic acid (II). Rearrangement in the presence of C14-labeled carbon monoxide yielded labeled geronic acid. The possibillty that this incorperation is due to exchange of the carboxylic carbon of either the starting material I or the product II with the externally supplied carbon monoxide is excluded by appropriate c ontrol experiments.

Evidence from the acidity and temperature dependence of the rates of O18 exchange and dehydration of t-alcohols was obtained; this evidence indicates that these two reactions proceed by common initial steps but involve different rate-determining steps. The results appear to eliminate a mechanism in which a "free" carbonium ion isomerizes to a pi -complex in the rate-determining step of the alcohololefin interconversion. Present results are found to be consistent with mechanisms which involve (in the formation of olefin from alcohol) either a rate-determining reaction of a free carbonium ion with water or the isomerization of an encumbered carbcnium ion intermediate, R⁺... OH², to a pi -complex. The encumbered carbonium ion classification is proposed for intermediates which possess substantial carbonium ion character and involve leaving or entering groups of either neutral or various charge types. The mechanism involving the encumbered carbonium ion intermediate is favored. (auth)

The process of cratering in materials is described in terms of four phases: transient, primary, secondary, and recovery. Rod projectiles were used in an experimental study of the relative importance of each phase and its influence on final crater dimensions. Aluminum and steel rods with aspect ratios of 1/6 to 25 were impacted into metallic and nonmetallic target materials at impact velocities of 0.3 to 6.7 km/sec. During the primary penetration phase, rod deformation was found to be comparable to that observed for shaped‐charge liner collapse, and measured rod penetration rates showed good agreement with rates calculated on the basis of incompressible fluid flow considerations. Empirically developed equations are presented for predicting crater penetration and volume in metal targets.

Results of a calculation from first principles of the change on mixing of the electronic energy for seven molten lithium-sodium mixtures are presented. These results, along with the assumption of an ideal entropy of mixing, are used to predict the miscibility curve which forms the boundary on the phase diagram between the region of a single homogeneous melt and the region of two separated melts. Favorable agreement with experiment is obtained. Calculated energies for the lithium-sodium system are compared with energies previously found for the sodium-potassium system, a system for which the melts are miscible in all concentrations. This comparison reveals that it is chiefly the change on mixing of the average kinetic energy of the electrons which is responsible for the lithium-sodium miscibility gap. For the lithium-sodium system, the kinetic energy is found to increase on mixing, while for sodium-potassium and other liquid binary alkali mixtures for which no gap exists, the kinetic energy was found to decrease. In all other respects the mixing behavior of lithium and sodium seems to follow the general pattern previously established for other molten binary alkali mixtures.

Although it is well established from animal perfusion studies that the lung can remove and deactivate circulating vasoactive amines, the significance of this possible regulatory function and its relationship to lung disease, drug therapy, and anesthesia has been difficult to determine in humans largely due to the lack of a safe, noninvasive technique for such an evaluation. We have sought to use suitable tracer molecules labeled with radioactive nuclides which decay by the emission of radiation which can be detected outside the body barrier as a probe for this aspect of lung metabolism both in animals and humans.