Search

We present results from global VLBI and VLA observations of three Fanaroff-Riley type I radio galaxies, 3C 31, 4C 35.03, and 3C 264, at a frequency of 5 GHz. In all three cases, we observe asymmetric parsec-scale structures consisting of a compact core and a single jet pointing in the direction of the more prominent kiloparsec jet. We interpret such alignment as evidence for the relativistic nature of FR I radio jets at parsec scales. Comparing the VLBI and VLA images of these sources, we find a progressive deceleration of the plasma flow from parsec to kiloparsec scales. We consider another five FR I radio galaxies studied previously by us and find that, in a set of eight FR I objects, the estimated jet bulk velocities and orientation angles with respect to the observer are consistent with the requirements of the unification model for low-power radio sources.

The use of Rietveld refinement using powder neutron diffraction data provides a unique means to measure the atom-species-specific mean square thermal displacements; while molecular dynamics (MD) using ab initio-based atomistic potentials provides a means of calculating predictively these same quantities without any fitting or use of experimental data whatsoever. In this paper application of this neutron-diffraction-based technique to a metallic system is reported for the first time and it is found that the differences in thermal amplitudes for Ni and Al are in close agreement with our ab initio-based MD predictions, and that absolute values are about a third greater.

1Fast inward currents were elicited in freshly isolated sheep lymphatic smooth muscle cells by depolarization from a holding potential of −80 mV using the whole‐cell patch‐clamp technique. The currents activated at voltages positive to −40 mV and peaked at 0 mV.2When sodium chloride in the bathing solution was replaced isosmotically with choline chloride inward currents were abolished at all potentials.3These currents were very sensitive to tetrodotoxin (TTX). Peak current was almost abolished at 1 μM with half‐maximal inhibition at 17 nM.4Examination of the voltage dependence of steady state inactivation showed that more than 90 % of the current was available at the normal resting potential of these cells (−60 mV).5The time course of recovery from inactivation was studied using a double‐pulse protocol and showed that recovery was complete within 100 ms with a time constant of recovery of 20 ms.6Under current clamp, action potentials were elicited by depolarizing current pulses. These had a rapid upstroke and a short duration and could be blocked with 1 μM TTX.7Spontaneous contractions of isolated rings of sheep mesenteric lymphatic vessels were abolished or significantly depressed by 1 μM TTX.

1Isolated sheep urethral cells were studied using the perforated patch clamp technique (T= 37 °C). Depolarizing steps ranging from ‐40 to ‐10 mV evoked an inward current that peaked within 10 ms and a slower inward current. Stepping back to the holding potential of ‐80 mV evoked large inward tail currents. All three currents were abolished by nifedipine (1 μm). Substitution of external Ca2+with Ba2+resulted in potentiation of the fast inward current and blockade of the slow current and tails.2Changing the chloride equilibrium potential (ECl) from 0 to + 27 mV shifted the reversal potential of the tail currents from 1 ± 1 to 27 ± 1 mV (number of cells, n= 5). Chloride channel blockers, niflumic acid (10 μm) and anthracene‐9‐carboxylic acid (9AC, 1 mm), reduced the slow current and tails suggesting that these were Ca2+‐activated CF currents, ICl(Ca).4Caffeine (10 mm) induced currents that reversed at ECland were blocked by niflumic acid (10 μm).5In current clamp mode, some cells developed spontaneous transient depolarizations (STDs) and action potentials. Short exposure to nifedipine blocked the action potentials and unmasked STDs. In contrast, 9AC and niflumic acid reduced the amplitude of the STDs and blocked the action potentials.6In conclusion, these cells have both L‐type ICaand ICl(Ca). The former appears to be responsible for the upstroke of the action potential, while the latter may act as a pacemaker current.

Abstract:  Whole-cell and inside-out patch-clamp techniques were used to assess the action of a well-known dye, Evans blue, on membrane currents in bladder isolated smooth muscle cells from sheep. In whole cells Evans blue dose-dependently increased the outward current by up to fivefold. In contrast, Evans blue had no effect on inward Ca2+ current. The effect on outward current was abolished or reduced if the cells were bathed in Ca2+-free solution, iberiotoxin (5 × 10–8 M), or charybdotoxin (5 × 10–8 M), but was unaffected by externally applied caffeine (5 mM) or in cells exposed to heparin (1 mg/ml) via the patch pipette. In inside-out patches bathed in a Ca2+ concentration of 5 × 10–7 M, Evans blue (10–4 M) increased the open probability of large-conductance (298-pS) Ca2+-dependent K+ channels (BK channels), shifting the half maximal-activation voltage by –70 mV. We conclude that Evans blue dye acts as an opener of BK channels.

The parsec scale properties of low power radio galaxies are reviewed here, using the available data on 12 Fanaroff-Riley type I galaxies. The most frequent radio structure is an asymmetric parsec-scale morphology--i.e., core and one-sided jet. It is shared by 9 (possibly 10) of the 12 mapped radio galaxies. One (possibly 2) of the other galaxies has a two-sided jet emission. Two sources are known from published data to show a proper motion; we present here evidence for proper motion in two more galaxies. Therefore, in the present sample we have 4 radio galaxies with a measured proper motion. One of these has a very symmetric structure and therefore should be in the plane of the sky. The results discussed here are in agreement with the predictions of the unified scheme models. Moreover, the present data indicate that the parsec scale structure in low and high power radio galaxies is essentially the same.

1The patch‐clamp technique was used to measure membrane currents in isolated smooth muscle cells dispersed from sheep mesenteric lymphatics. Depolarizing steps positive to −30 mV evoked rapid inward currents followed by noisy outward currents.2Nifedipine (1 μM) markedly reduced the outward current, while Bay K 8644 (1 μM) enhanced it. Up to 90% of the outward current was also blocked by iberiotoxin (Kd= 36 nM).3Large conductance (304 ±15 pS, 7 cells), Ca2+‐ and voltage‐sensitive channels were observed during single‐channel recordings on inside‐out patches using symmetrical 140 mM K+solutions (at 37 °C). The voltage required for half‐maximal activation of the channels (V½) shifted in the hyperpolarizing direction by 146 mV per 10‐fold increase in [Ca2+]i.4In whole‐cell experiments a voltage‐dependent outward current remained when the Ca2+‐activated current was blocked with penitrem A (100 nM). This current activated at potentials positive to −20 mV and demonstrated the phenomenon of voltage‐dependent inactivation (V½=−41 ± 2 mV, slope factor = 18 ± 2 mV, 5 cells).6Tetraethylammonium (TEA; 30 mM) reduced the voltage‐dependent current by 75% (Kd= 3.3 mM, 5 cells) while a maximal concentration of 4‐aminopyridine (4‐AP; 10 mM) blocked only 40% of the current. TEA alone had as much effect as TEA and 4‐AP together, suggesting that there are at least two components to the voltage‐sensitive K+current.7These results suggest that lymphatic smooth muscle cells generate a Ca2+‐activated current, largely mediated by large conductance Ca2+‐activated K+channels, and several components of voltage‐dependent outward current which resemble ‘delayed rectifier’ currents in other smooth muscle preparations.

We present new VLA, MERLIN, and VLBI images for the radio galaxy 3C 338 and the results of the monitoring of its arcsecond core flux density. Present high-sensitivity observations allow us to investigate the radio structure of this source and to confirm the presence of two symmetric parsec-scale jets. Morphological changes between different epochs are evident, and a proper motion with ? ~ 0.4 h-1has been derived. This allows us to give a lower limit for the Hubble constant. While the steep-spectrum large-scale structure of 3C 338 could be a relic emission, the small-scale structure looks young, similar to the high-power medium-sized symmetric objects (MSOs) found at high redshift.

The reactions of a series of fluorinated olefins with hexamethylditin have been investigated, under conditions which favor the formation of (CH3)3Sn• radicals. Two principal types of products have been isolated, namely (polyfluoroalkyl)trimethyltin compounds, e.g. (CH3)3SnCF2CF(R)H, and insertion products of the type (CH3)3SnCF2CF(R)Sn(CH3)3, where R = F or CF3. These results are consistent with the formation of intermediate radicals such as (CH3)3SnCF2C(R)F• which then participate either in hydrogen abstraction or in the formation of the insertion products. Reactions of hexamethylditin with CF2=CFH, CF2=CH2, CF2=CFCl, CF2=CFBr, and C2H4are also discussed. The direction of attack of the (CH3)3Sn• radical on the olefins indicates that the former has a high degree of nucleophilic character. A more detailed study of the reactions of the cyclic hexamers of dimethyltin and diphenyltin with tetrafluoroethylene shows that some addition does occur, but that the products are of indeterminate composition. The reaction of hexameric dimethyltin with trifluoroiodomethane has also been examined.

Biotin is a common functional handle for bioconjugation to proteins and DNA, but its uses are limited to protein-containing conjugation partners such as streptavidin and derivatives thereof. Recently, oxaziridine reagents were developed that selectively conjugate the thioether of methionines on the surface of proteins, a method termed redox-activated chemical tagging (ReACT). These reagents generate sulfimide linkages that range in stability depending on the solvent accessibility and substitutions on the oxaziridine. Here we show that oxaziridine reagents react rapidly with the thioether in biotin to produce sulfimide products that are stable for more than 10 d at 37 °C. This method, which we call biotin redox-activated chemical tagging (BioReACT), expands the utility of biotin labeling and enables a predictable and stable chemical conjugation to biomolecules without the need to screen for a suitable methionine conjugation site. We demonstrate the versatility of this approach by producing a fluorescently labeled antibody, an antibody–drug conjugate, and a small molecule-conjugated oligonucleotide. We anticipate that BioReACT will be useful to rapidly introduce biorthogonal handles into biomolecules using biotin, a functional group that is widespread and straightforward to install.

"There is many slip 'twixt the cup and the lip." PalladasTHE 91st Congress of the United States, whose stormy existence came to a loquacious end on Dec 31, 1970, passed several major bills of immediate concern to psychiatrists. Having been duly signed by President Nixon, these acts are now law.In the following, five of these statutes will be summarized. Then, an attempt will be made to estimate the extent to which one can expect them to be implemented. There are significant barriers to the full implementation of programs which, ironically perhaps, only a few months ago were thought important enough to warrant congressional and Presidential initiatives.Community Mental Health Centers Amendments of 1970 (Public Law 91-211, S 2523)Title I of this statute extends the grant program for construction of community mental health centers for three years. In addition, it sets the maximum federal share for areas designated

The article reports on the move of the Internal Revenue Service (IRS) to chose 400 colleges and universities to join in a compliance project that examined their executive compensation packages in the U.S. It notes the steps that need to be followed by the Association of Governing Boards of Universities and Colleges (AGB) which provide safe harbor protections for the board and the president. It mentions that the board be ready to respond to assertions of the IRS.

The pre-main sequence (PMS) star AB Dor A is the main component of the quadruple system AB Doradus. The precise determination of the mass and photometry of the close companion to AB Dor A, AB Dor C, has provided an important benchmark for calibration of theoretical evolutionary models of low-mass stars. The limiting factor to the precision of this calibration is the age of the system, as both the mass and luminosity of AB Dor A and C are well monitored by other ongoing programs. In this paper we present VLTI/AMBER observations of AB Dor A which provide a direct measurement of the size of this star, 0.96 ± 0.06 R⊙. The latter estimate, combined with other fundamental parameters also measured for this star, allows a precise test of PMS evolutionary models using both H-R diagrams and mass-radius relationships. We have found that our radius measurement is larger than that predicted by the models, which we interpret as an evidence of the oversizing produced by the strong magnetic activity of AB Dor A. Considering, at least partially, this magnetic effect, theoretical isochrones have been used to derive constraints to the age of AB Dor A, favouring an age about 40–50 Myr for this system. Older ages are not completely excluded by our data.

The origin of the far-infrared emission from the nearby radio galaxy M 87 remains a matter of debate. Some studies find evidence of a far-infrared excess due to thermal dust emission, whereas others propose that the far-infrared emission can be explained by synchrotron emission without the need for an additional dust emission component. We present HerschelPACS and SPIRE observations of M 87, taken as part of the science demonstration phase observations of the HerschelVirgo Cluster Survey. We compare these data with a synchrotron model based on mid-infrared, far-infrared, submm and radio data from the literature to investigate the origin of the far-infrared emission. Both the integrated SED and the Herschelsurface brightness maps are adequately explained by synchrotron emission. At odds with previous claims, we find no evidence of a diffuse dust component in M 87, which is not unexpected in the harsh X-ray environment of this radio galaxy sitting at the core of the Virgo cluster.

Argues for the provision of a generous salary and compensation package to college and university presidents. Need for trustee boards to attract the best talent with an expansive managerial experience; Tendency for trustees to construct colleges as business entities; Need for trustees to use their best judgment when compensating college presidents.

The two isomorphous, air‐stable title compounds (I) crystallize in the space group P43 with Z=4.

DURING the past three years a very serious reduction in the growth of Zostera marina has taken place on the Atlantic coast of North America. Practically the whole coast-line from New Brunswick to North Carolina is affected and in some areas the reduction amounts to its total disappearance. A mimeographed paper by Dr. Harrison F. Lewis, of the Department of the Interior, Canada, gives an account of the situation up to the autumn of 1932, and a further report by Mr. Clarence Cottam (dated June 1933) prepared for “The Plant Disease Reporter” of the U.S. Department of Agriculture, has now been received. The cause of the destruction is not known, but the attack is spoken of as an epidemic (“epiphytotic”).

Developed by the physician-lawyer authors as a problem-oriented legal case book to be used in teaching both medical and law students, this work will have great interest for the medical profession. The problems dealt with include professional liability, medical proof in litigation, and profession responsibility. Also presented is a fascinating section which explores the relationship between public policy and medical science.The method of presenting the issues proves to be almost as intriguing as the issues themselves. Use of the "case method" means that actual law cases are reproduced, with the nonessentials edited out and the cases themselves linked together with editorial commentary. The introductory chapter discusses a subject which runs as a thread throughout the book: the harm "done to the mutual esteem in which the professions ought to hold one another when the practitioner in one seeks to treat another professional as a mere technician." The authors declare