Search

Virgin alate queens of the carpenter ant, Camponotus pennsylvanicus, shed their wings when fed a 2% suspension of the insect growth regulator RO 13–5223 ad libitum more frequently than controls. No inhibitory effects on the production of secretions attractive to workers was found for treated virgin alate queens. Treatment of field colonies with insect growth regulators in baits resulted in weaker autocorrelation of foraging activity, although the percentage of large workers in the forager force demonstrated the same autocorrelation patterns as found in control colonies. Topical treatments of last instar larvae with 50 μg of RO 13–5223 greatly decreased pupation rates, while no difference was found between treatments of 10 μg RO 13–5223, 10 and 50 μg of methoprene. Zusammenfassung Zur Wirkung von Insektenwachstumsregulatoren auf das Verhalten und die Entwicklung der Holzameise Camponotus pennsylvanicus (Deg.) (Hym., Formicidae) Virgine geflugelte Koniginnen von C. pennsylvanicus warfen in groserer Zahl als in Kontrolle ihre Flugel ab, wenn sie mit einer 2%igen Suspension des Insektenwachstumsregulators RO 13–5223 gefuttert wurden. Dagegen zeigten derart gefutterte Koniginnen keine Veranderung hinsichtlich der Produktion von Sekreten, die auf Arbeiterinnen attraktiv wirken. Nach Behandlung von Freilandkolonien mit dem Wachstumsregulator in Koderform ergab sich eine Abschwachung der Autokorrelation der Nahrungssuche-Aktivitat, obgleich der Anteil an grosen Arbeiterinnen gegenuber Kontrolle gleich blieb. Topikale Behandlung der wachsenden Larven mit RO 13–5223 fuhrte zu starker Verminderung der Wachstumsrate, wobei zwischen 10 μg des RO-Praparates sowie 10 und 50 μg Methopren keine Wirkungsunterschiede auftraten.

A new dynamic technique for the measurement of thermal conductivity is being developed at IMGC. The experiment consists in bringing the specimen to high temperatures with a current pulse and in measuring the temperature profiles during the free cooling period. Different techniques can be used to extract the information on thermal conductivity from the profiles. The numerical computation of thermal conductivity from the experimental temperature profiles in absolute space is possible, but it is difficult and cumbersome because one must know and take into the account the exact position of the infinitesimal elements of the specimen in different profiles. Computations in tube-space (a fictitious space where no thermal expansion occurs) are simpler and lead to less complex numerical computations. Complementary techniques to evaluate thermal conductivity as a function of temperature or at constant temperature are presented with a discussion of advantages and disadvantages of each method. Computer simulations have tested the precision of the complex software. Numerically generated temperature profiles from known thermophysical properties have been obtained and thermal conductivity has been recomputed from the profiles. The relative difference using different computational approaches and different fitting functions is always less than 0.1%.

Excitation functions for sub-barrier one- and two-neutron pickup reactions were measured for ${\mathit{E}}_{\mathrm{lab}}$\ensuremath{\le}106 MeV in $^{32}\mathrm{S}$${+}^{93}$Nb, $^{98,100}\mathrm{Mo}$ systems by detecting targetlike recoils at 0\ifmmode^\circ\else\textdegree\fi{} using a recoil mass spectrometer. The slopes of transfer probability vs distance of closest approach are in good agreement with binding energies, indicating the absence of a ``slope anomaly.'' Angle-integrated transfer cross sections derived from measured 180\ifmmode^\circ\else\textdegree\fi{} yields are consistent with enhancements in previously measured fusion yields for the $^{32}\mathrm{S}$${+}^{98,100}$Mo systems.

Direct breakup of {sup 7}Li{r arrow}{alpha}+{ital t} was measured for 54-MeV {sup 7}Li+{sup 12}C, {sup 197}Au reactions. The breakup products were detected in coincidence using a close-geometry detection system, and small scattering angles forward of grazing, were investigated. The direct-breakup cross sections for {sup 12}C ({sup 7}Li, {alpha}{ital t}){sup 12}C{sub g.s.} exhibit significant enhancements beyond predictions of simple {ital E}1 Coulomb-breakup calculations, indicating the importance of the nuclear field. Direct-breakup yields in {sup 197}Au({sup 7}Li,{alpha}{ital t}) quasielastic reactions are sensitive to detector geometry, with the asymptotic fragment energies exhibiting target-proximity effects. Three-body classical trajectory calculations are found to provide qualitative agreement with these observations, provided the projectile is treated as an extended object. These strong Coulomb and nuclear effects severely complicate the extraction of radiative-capture cross sections and low-energy astrophysical {ital S} factors.

Prompt protons emitted in low-energy 28 Si+ 98 Mo, 58 Ni reactions were measured in coincidence with evaporation residues using a velocity filter. The proton energy spectra are found to be sensitive to the residue mass. Mass-gated spectra at forward angles show non-statistical protons characterized by a high-energy bump. A simple Serber-like model for breakup-fusion reproduces the data well.

Strong direct processes were observed for elastic breakup in 54-MeV $^{7}\mathrm{Li}$${+}^{12}$C $^{197}\mathrm{Au}$ reactions. In the case of $^{12}\mathrm{C}$, the observed $^{7}\mathrm{\ensuremath{\alpha}}$+t direct-breakup yield was significantly larger than predicted by a Coulomb-breakup calculation, indicating the importance of the nuclear field. For $^{197}\mathrm{Au}$, final-state interactions produced a strong distortion in the fragment energy spectra, as well as a modulation of the coincidence efficiency for different detector geometries. Such Coulomb effects are found to severely complicate the extraction of radiative-capture cross sections from direct-breakup data.

Techniques of chromatography on columns of DEAE cellulose and sedimentation analysis through a sucrose gradient have been used to study the flow of C(14)-uracil label through precursors to completed ribosomes. Analysis by chromatography shows the existence of two sequential precursors constituting together some 10 per cent of the total ribosomal RNA. The chromatographic separation into three fractions is ascribed to the lower protein/RNA ratios of the precursor. By sedimentation the primary precursor (eosome) is identified as a component of average sedimentation coefficient 14S. The second precursor stage (neosome) is divided among at least two particles, one of 43S and the other of about 30S. Detailed kinetic analysis shows that all the radioactivity passes through the eosome on its way to finished 50S and 30S ribosomes. The delay in the entry of radioactivity to ribosomes is that expected from the quantity of eosome precursor. The obvious conclusion that there exists a precursor-product relationship is discussed together with possible interpretations.

Measurements are reported of the linear thermal expansion of polycrystalline samples of BiCaSrCu oxide and BiPbCaSrCu oxide from 2 K up to about 1000 K. The measurements are compared with our earlier data on LaSrCu oxide and YBaCu oxide materials and are found to be similar in magnitude at normal temperatures. Near the superconducting transition temperature T c, anomalies in the linear coefficient α (T) are small and similar in relative magnitude to those observed in the heat capacity.

A new dynamic technique for the measurement of thermal conductivity at high temperatures has been developed at the IMGC. The specimen is brought to high temperatures with a current pulse; during cooling the heat content is dissipated by radiation and by conduction. The differential equation describing this process contains terms related to the heat capacity, the hemispherical total emittance, and the thermal conductivity of the material. If the first two properties are determined using the same specimen during subsecond pulse heating experiments, thermal conductivity may be evaluated by accurate measurements of the round-shaped temperature profiles established on the specimen during cooling. High-speed scanning pyrometry makes possible accurate measurements of temperatures and of temperature derivatives (with respect to space and time), which enables the differential equation describing the power balance at each point of the specimen to be transformed into a linear equation of the unknown thermal conductivity. A large overdetermined system of linear equations is solved by least-squares techniques to obtain thermal conductivity as a function of temperature. The theory underlying the technique is outlined, the experimental apparatus is described, and details of the measurement technique are given.

The elastic moduli of 350 grade maraging steel in the annealed and hardened states have been determined in the temperature range 4.2 to 300 K. Thermal expansion of these steels and pure iron are given for the range 2 to 800 K. The elastic moduli show a normal temperature dependence, increasing with decreasing temperature, and a zero temperature derivative at 0 K. The low-temperature thermal expansion coefficient is the sum of a linear and cubic term, the former having a negative sign for the steels, which is probably due to magnetic effects. The elastic moduli increase by about 10% on hardening, and this increase is correlated with the structural changes caused by the hardening process.

The existing MTA-New York City Transit’s (MTA-NYCT) No. 7 Subway was built in the early 1900’s and currently terminates at Times Square near 41 st Street and Seventh Avenue. As part of the City’s redevelopment of the west side of Manhattan, the MTA NYCT’s No. 7 Subway extension project will add approximately 1.5-miles of twin tunnel alignment to the current line. The proposed alignment will extend from the existing Times Square Station west beneath 41 st Street then turn south under 11 th Avenue and terminate between 24 th and 25 th Streets. The project will include two new stations, a two-track line station and a three -track terminal. The project includes two major construction contracts: the running tu nnels which would include TBM launching shaft (Shaft A) and retrieval shaft (Shaft L) , and (2) the follow -on contract, which would include drill-and-blast mined cavern enlargements of the two stations and the drill-and-blast excavation for tunnels connecting the end of the TBM running tu nnels to the existing No. 7 Subway Line at Times Square Station. This paper will focus on how Shaft A will be designed and constructed to mitigate impact on adjacent properties and utilities. A stiff support system will be adopted to minimize deflections to the shaft walls. Instrumentation will be utilized to monitor the performance of the support system and to verify the design and predicted effects of construction. The instrumentation will be designed to monitor actual loads and deflections within the shaft as well as the associated ground movements and settlements.

Consecutive single-patient methicillin-resistant Staphylococcus aureus (MRSA) isolates (270) from 12 hospitals (8217 beds) in metropolitan New York City were collected during May 1996. In 11 of 12 hospitals, MRSA was most frequent in the general medical services. DNA typing ("fingerprinting") revealed that mecA:Tn554:PFGE (pulsed-field gel electrophoresis) type I:A:A accounted for 113 (42%) of 270 isolates, was detected in all hospitals, and was the predominant clone in 9. Thirteen of 15 I:E:F isolates were from 1 hospital, and the remaining 2 were from another hospital of the same health system. Type V:NH:E was isolated from 22 (79%) of the 28 patients with AIDS, including 8 of 9 patients from an additional hospital. Subtype V:NH:E2 was recovered from 11 patients, 9 of whom had AIDS, including all 5 AIDS patients from one floor of a nursing home affiliated with a third hospital. By using both mecA:Tn554 probes and PFGE, MRSA clusters and outbreaks may be detected and provide a rationale for appropriate infection control intervention.

A double-blind, randomized, placebo-controlled trial comparing two daily doses of oral ribavirin (600 and 800 mg) and a placebo was performed at four medical centers geographically distributed throughout the USA. One hundred and sixty-four HIV-infected adult men with lymphadenopathy were enrolled over a 2-month period and received active treatment for 24 weeks followed by a 4-week interval during which they did not receive the study drug. A marked interlaboratory variation in HIV isolation from peripheral blood mononuclear cells was observed, underscoring the critical role of quality assurance in similar multicenter trials. Nevertheless, the combined data indicate that ribavirin did not significantly suppress HIV activity (on measurement of reverse transcriptase activity) after week 6 or reduce serum p24 antigenemia.

Data are reported for the linear thermal expansivity, alpha , of one sample of La1.85Sr0.15CuO4 and four samples of YBa2Cu3O7 in the temperature range 2 to 1000 K. Values are calculated for the Gruneisen parameter, gamma approximately=0.7, using ultrasonic data for the elastic moduli. Published compressibility measurements give much higher values of the bulk modulus and of gamma .

The absolute thermoelectric power of lead has been determined by direct measurement of its Thomson heat from 10 to 350 K. The scale established by Christian, Jan, Pearson and Templeton (1958) is found to be in error above 20 K by as much as 0·3μV/K. The error significantly affects the analysis of thermopowers which are less than 3μV/K above about 40 K.

At low temperatures, the linear expansion coefficient α of a Cr + 0.5% V alloy is similar to that of chromium, i.e. 1010α = -37 T + 0.02 T3K−1 (T

An apparatus has been developed for the simultaneous measurement of the thermopower and thermal conductivity of metal wires by means of an integral method over the range from 2 to 300 K. Results on pure aluminium are presented. A new scale for the thermopower of lead has been used. A separation of the components is successfully effected over the whole range by means of Kohler's rule. The phonon drag and diffusion components of the thermopower are found to be about equal at room temperature.

Data for the heat capacity, electrical resistivity, hemispherical total emittance, and normal spectral emittance (at 898 nm) of niobium are reported for the temperature range 1000–2500 K. Measurements were based on a subsecond pulseheating technique. The results are discussed and compared with the literature values. Reported uncertainties for the properties are 3% for heat capacity, 1% for electrical resistivity, 5% for hemispherical total emittance, and 4% for normal spectral emittance.

Utilizing monolayers of human polymorphonuclear leukocytes, optimal conditions for attachment and ingestion of Neisseria gonorrhoeae were determined. Both attachment and ingestion were optimal at 36 degrees C when a bacteria-leukocyte ratio of 100:1 was employed. After 30 min of incubation, log-phase viable type 2 gonococci were attached to 90% of leukocytes, whereas log-phase viable type 4 gonococci were ingested by 80 to 90% of cells. Respiratory inhibitors had no effect on attachment or ingestion, whereas glycolytic inhibitors blocked ingestion but did not affect attachment of gonocci to the leukocyte surface. Inhibition was dose dependent and partially reversible. The oxidative metabolism of leukocytes with gonococci attached or ingested was also examined. Attachment of log-phase type 2 gonococci stimulated a minimal increase in glucose oxidation and oxygen consumption by leukocytes in contrast to marked increases by leukocytes that had ingested viable type 4 or heat-killed typed 2 organisms. These results demonstrate that attachment of log-phase type 2 gonococci to the surface membrane does not stimulate significant leukocyte oxidative metabolism nor initiate the phagocytic process.

Cultivation of Neisseria gonorrhoeae in the allantoic cavity of 10-day chick embryos ensured the following necessary properties for subsequent quantitive in vitro phagocytosis studies of viable gonococci: log phase of growth, resistance to the cidal effect of fresh human serum, maintenance of colonial type, and absence of clumping. Employing a modification of the Maaloe technique, phagocytosis of log-phase type 1 and 2 gonococci by human PMN leukocytes did not occur in the presence or absence of serum. These findings indicate that log-phase type 1 and 2 gonococci possess antiphagocytic surface factors Stationary-phase organisms of the same colonial type were ingested and rapidly killed by human PMN leukocytes under similar experimental conditions, thus emphasizing the necessity to employ log-phase gonococci in the study of phagocytosis and antiphagocytic surface factors. Log-phase type 4 gonococci were ingested and rapidly killed by human PMN leukocytes in the presence of fresh human serum but not heat-inactivated serum or in the absence of serum. Morphologic studies demonstrated that log-phase viable gonococci attach to the surface membrane of human PMN leukocytes. Interiorization of avirulent but not virulent organisms was observed in the presence of fresh human serum. Gonococci-human PMN leukocyte interactions thus provide a model for the investigation of the nonimmunologic and immunologic parameters associated with the attachment and ingestion stages of phagocytosis.

The Tl-Ba-Ca-Cu-O system, when prepared by standard sintering procedures, shows mass loss by volatilisation of Tl even at sintering temperatures lower than the decomposition temperature of Tl2O3 (850°C). The disappearance of Tl results in difficulties in preparation, especially since Tl2O3 emission is severely toxic. The use of a two-stage sintering technique involves first the preparation of Ba-Ca-Cu-O by standard ceramic processing, so that TI2O3 can be added to the sintered Ba-Ca-Cu-0, enclosed in a silver tube, and sintered. This technique ensures reproducible results and safety. Two superconducting phases were confirmed by Tc measurements, x-ray diffraction patterns, and electron microanalysis. The materials were characterised by DTA, electrical and magnetic measurement, and TEM. Prolonged sintering degraded the superconducting properties, probably due to thallium evolution. Transition broadening in applied magnetic fields is ascribed to anisotropy.

To determine the potential immunotherapeutic role of interferon-gamma (IFN-gamma) as a mononuclear phagocyte-activating agent, we examined the effector cell function of peripheral blood monocytes from healthy donors and acquired immunodeficiency syndrome (AIDS) patients after either in vitro and/or in vivo treatment with recombinant (r) IFN-gamma. When assayed immediately after a 24-hr in vitro pulse with 300 U/ml, normal and AIDS monocytes behaved similarly with little augmentation of their intrinsically high levels of H2O2 release and activity against Toxoplasma gondii; in contrast, activity toward the more resistant intracellular pathogen, Leishmania donovani, was appreciably enhanced by rIFN-gamma. In addition, upon testing 4 to 6 days after in vitro pulsing, both normal and AIDS monocytes showed clear evidence of persistent activation in all three assays. The capacity of IFN-gamma to similarly activate monocytes in vivo was confirmed in all ten treated AIDS patients by examining cells before and after 24-hr infusions of 0.03 and 0.5 mg of rIFN-gamma/square meter (M2) of body surface area. For postinfusion monocytes tested after 1 day in culture, H2O2 release and antitoxoplasma activity were essentially unchanged, but antileishmanial effects were augmented. After 5 to 7 days in culture, monocytes from treated patients showed 3.2- to 5.9-fold increases in H2O2-releasing capacity and increases of 49 to 68% and 35 to 61% in intracellular activity against T. gondii and L. donovani, respectively. These results indicate that the human monocyte can be induced by rIFN-gamma to express signs of both immediate and persistent activation and suggest that, as a direct activator of mononuclear phagocytes, rIFN-gamma may also have potential as an immunotherapeutic agent for patients with intracellular infections.

Measurements of thermal expansion through the Neel transition show that, when V, Mo or Mn atoms are substituted in the Cr lattice, the nature of the antiferromagnetic transition changes from weak first order in pure Cr to continuous. The possible tricritical point in CrV is close to 0.2 at.% V.

The linear thermal expansions of CaF2, BaF2, SrF2, PbF2 and SrCl2 have been measured from room temperature up to their melting points. The linear coefficient alpha exhibits a Schottky-like bump similar to that observed previously for the heat capacity, Cp, and associated with fast-ion conduction in these fluorite-structure materials. Values for the Gruneisen parameter gamma (T) are included.

Measurements of the coefficient of linear thermal expansion of pure polycrystalline silicon were made with a polarization interferometer and a platinum resistance thermometer with an estimated error of less than 0.01 × 10-6 K-1.

The linear thermal expansion coefficient alpha of pure Cr and of dilute CrV alloys containing up to 5 at.% V has been measured from 2 to 700K. Paramagnetic Cr95V5 provides a reference to determine the effect of antiferromagnetic ordering in the other samples, whose Neel temperatures TN range from 27K for Cr+3.4 at.% V to 311K for Cr. In each case alpha (T) falls well below the paramagnetic value but returns to the paramagnetic alpha p(T) curve at a temperature somewhat above TN. Below about 20K all the antiferromagnets have large negative alpha linear in T. Beyond about 500K the Gruneisen parameter gamma of Cr is about 1.5, and it remains roughly constant up to 1500K.

Scanning pyrometry with microsecond time resolution was developed at the IMGC for measurement of thermophysical properties by dynamic techniques. A new pulse method (subsecond experiment) for the measurement of thermal expansion at high temperatures is presented, in which the expansion of a long speciment is correlated to its temperature profile. A new dynamic technique (20–30 s experiment) for the measurement of thermal conductivity is described. Both measurement methods are made possible by high-speed scanning pyrometry.

Annual activity cycles of carpenter ants and subterranean termites were extracted from data maintained by cooperative extension service entomologists in Connecticut, Maryland, New Jersey, North Carolina and Ohio. Autocorrelations suggested a strong cyclic patterning of public complaints, which increased in regularity from south to north. Spectral analysis revealed that the more northern states had complaint peaks occurring at longer frequencies, while more southern states had shorter frequency fluctuations, as expected if climatological factors drive the system. The existence of data such as these can be of great value in designing field experiments.

We have measured the Thomson coefficient μ of platinum and tungsten from 900 to 1600 K and calculated the absolute thermopower S of each. We describe a numerical technique for evaluating the temperature profile of a wire which is undergoing self-heating by direct current and discuss the experimental design problems associated with measuring μ at high temperatures. We develop a method in which the direction of the current through the specimen is reversed about once per second and observe the rates of heating and cooling at different places with an optical pyrometer. By changing the magnitude of the current at the same time as its reversal the change in the Joule heating is balanced with the change in the Thomson heating. We describe a technique for calibrating the pyrometer, report measurements of μPL and μW, calculate S Pt and S w, and test the results according to Kelvin's relation, S = f μ/T dT. The difference between our S Pt, and that given by Cusack and Kendall (1958) varies from −0·7μV K−1 ...

Laser holography was used to study the characteristics and behavior of insecticide aerosols. It allowed direct 3-dimensional stop-action study of spray particles as they impinged onto the larva of the western spruce bud worm, Choristoneura occidentalis Freeman, and its silk webbing. The setae of this insect were effective impingement structures for particles ranging from submicron to 20µ diameter. Spray droplets coalesced on the tip and migrated to the base, both with and against the spray current and against gravity. Among 5 solvents studied there was significant evaporation of relatively nonvolatile solvents, particularly when the droplets were below about 40µ diameter.

SummaryLarvae of the alfalfa leaf-cutter bee were reared on four diets in the laboratory: (1) pollen, (2) pollen-free commercial pollen substitute, (3) synthetic, (4) synthetic + pollen. Larvae given the diets from the age of 2–3 days all produced normal adults; larvae fed on pollen were significantly larger at maturity than undisturbed control larvae in cells; those fed on diets (2) and (4) were significantly smaller. Larvae fed on diet (4) were significantly smaller than those in all other groups. Larvae reared from the egg stage on diets (1), (2) and (4) produced normal adults, but those on diet (3) failed to reach pupation. The relative weights at maturity of these larvae were: diet (1) > control > diets (2) and (4).

This study involved identification by paper chromatographic techniques and quantization of the free amino acids in the blood of the migratory grasshopper, Melanoplus sanguinipes (F.). Differences between sexes, stage of development, and effects of adult aging were considered. The egg yolk of this species of grasshopper contained 26 amino acids. Of interest was the appearance of several amino acids at different periods during embryonic development. Among others, citrulline and ± and ³ aminobutyric acids were found in postdiapause but not in diapause eggs, and methionine was found in diapause but not in postdiapause eggs. Alpha-aminobutyric acid appeared during the middle of postdiapause development and then was absent until the 2nd nymphal stage. Twenty-six amino acids were identified in the blood of nymphal M. sanguinipes . Tryptophan was observed until the 2nd nymphal stage, after which it was not: observed in any subsequent stage of development. Aspartic acid had a similar pattern except that it was in the 4th, perhaps the 5th, nymphal stage and was not found again except in old grasshoppers. Of particular interest was the high concentration of numerous amino acids in the 3rd nymphal instar. Asparagine, proline, alanine, glycine, glutamine and valine, especially, showed increases at this stage. Most amino acids showed a high concentration during the 3rd nymphal stage. Arginine and glutamic acid showed a high concentration at the 2nd nymphal stage. Twenty-six amino acids also were identified in the blood of adult grasshoppers. However, they are not the same 26 amino acids found in the egg yolk or in nymphal grasshoppers. Taurine was found only in adult grasshoppers, and tryptophan was observed only in the egg yolk. There were sex-related qualitative and quantitative differences in the amino acid patterns. These included the presence of methionine sulfone almost exclusively in females, the more frequent occurrence of ³ aminobutyric acid in females, and the alpha isomer in males. Additionally, there was an apparent correlation between the occurrence of methionine sulfone and sulfoxide and egg formulation and/or gonad maturation. A total of ten ninhydrin-positive compounds were not identified.

Forty compounds were screened for synergism with from 1 to 5 insecticides on Choristoneura occidentalis Freeman, Zectran® (4-dimethylamino-3,5-xylyl methyl-carbamate), pyrethrins, and SD-9077 (4-methoxy-3,5-xylyl methylcarbamate) were not synergizd by any of the commonly known synergists, and Zectran was not synergized by numerous other compounds including amine oxidase inhibitors. Carbaryl was synergized by 4 of 22 compounds, and Landrin® (3,4,5-trimethy]phenyl methyl-carbamate 75%; 2,3,5-trimethylphcnyl methylcarbamate, 18%) was synergized by 7 of 23 tested. Two propynyl ether synergists tested with carbaryl were highly effective. The failure of the methylenedioxyphenyl compounds to synergize pyrethrins, Zectran, and SD-9077 and lack of in vitro oxidation of Zectran indicate that these insccticides are not influenced by the mixed-function oxidase system. Because of large losses of fluid after poisoning it may be that an important mode of action of these insecticides is “diuretic” on this insect.

The primary objective of this study was to determine if the grasshopper Melanoplus sanguinipes (F.) shows biochemical symptoms of stress in the amino acid content of its hemolymph. Changes in amino acid composition caused by diet had to be considered, since the grasshoppers were maintained on different diets. It was found that grasshoppers fed on the laboratory diet had a higher concentration of glutamine, glutamic acid, and asparagine and a greater number of ninhydrin-positive unidentified compounds. Differences in amino acid concentration also were noted in grasshoppers collected from different localities throughout the State of Idaho. The effect of drastic forms of stress on grasshoppers was most noticeable as an increase in concentration of glutamine and asparagine, and a decrease of proline. Taurine was found only in the blood of grasshoppers from crowded populations, and in physically restrained and electrically stimulated grasshoppers.

The nesting biology of Euglossa (Glossura) ignita chlorosoma Cockerell and E. (G.) imperialis Cockerell is described. Both species build nests inhabited by several adult females. The cells are aggregated in a single cluster, similar in arrangement to those of a bumblebee nest. Despite superficial similarities to the social organization of bumblebee colonies, it is concluded that the nonreproductive worker caste essential to sociality is lacking in the species studied and may be absent in all of the Euglossini. Some possible reasons for the absence of sociality are given. The larvae are described and compared with those of the subgenus Euglossa and the closely related genus Euplusia .

The linear thermal expansion of Zerodur has been measured from 20 to 300 K and the thermal conductivity from 2 to 100 K. For each property the temperature dependence appears to reflect the composite nature of the ceramic-glass.

An instrument for measuring the absolute thermal expansion of solids up to 1000 degrees C is described. A sensitivity of 10-8 degrees C-1 was achieved by means of a frequency stabilizer laser and a polarization interferometer. Details of the laser stabilization technique interferometer, automatic polarimeter, sample chamber and preliminary results on tungsten are given.

There is evidence that electromagnetic radiation can penetrate into solid samples of yttrium barium cuprate superconductors at magnetic flux densities of less than 1 mT. We have previously shown how this behaviour may lead to potentially useful inductive effects, but the penetration of flux is an obvious disadvantage for magnetic shielding applications. We describe here a technique for the quantitative measurement of the effectiveness of these materials as magnetic shields. We report the dependence of the shielding factor on sample microstructure, density, thickness, field strength, temperature and frequency. The technique provides a quick, reliable, non-contact means of establishing the ‘quality’ of a sample which correlates well with other properties such as the Meissner fraction, critical current density and long-term stability.

The temperature scale used in the analysis of neutron diffraction study of cubic ZnS1, is corrected. The revised temperature scale2 is used to re‐examine the thermal parameters. (AIP)

The onset of superconductivity at 140 K has been observed in the high Tc Y‐Ba‐Cu‐O system in samples consisting of 90% by volume of a single‐phase oxide of average cation ratio Y:Ba:Cu≂1:2:3. A sharp superconducting transition in the resistivity has been measured, where Tc0=140 K, Tc=93.2 K, ΔTc=0.5 K, and ‘‘zero resistance’’ was observed at 92.0 K. Transmission electron microscopy and energy dispersive spectroscopy measurements revealed that the superconducting phase consisted of a large number of microcrystallites of ≂0.5 μm size and that these contained a very high defect microtwinned/faulted structure.

The growth rate of three vitamin B6-dependent Streptococcus mitior (B6DS) and two non-B6DS strains in Todd-Hewitt broth, with and without vitamin B6 supplementation, was examined. Even in optimally supplemented culture media, the growth rate of the three B6DS strains was much slower than that of comparable non-B6DS strains. Uptake studies with [3H] pyridoxine suggest that these B6DS strains cannot assimilate pyridoxine. Although not transported intracellularly, pyridoxine inhibited the growth of B6DS strains in media supplemented with other vitamin B6 analogs, probably by binding to the vitamin B6 transport system and inhibiting the uptake of the other vitamin B6 analogs.