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The RoboMicroScope II is an image capture and analysis system, which enables the automated analysis of protein crystallization trials. The RoboMicroscope II couples robust hardware with intuitive software that tracks and assigns an objective score to each instance of a crystallization experiment. This machine can also be used in a manual mode, to increase the reliability, objectivity and efficiency of human scoring of crystallization trials. Background Structural biology has been widely embraced by the pharmaceutical and biotech industries as it provides an atomic description of macromolecules, and interactions between macromolecules and small (drug-like) molecules. X-ray crystallography is the most widely used technique for macromolecular structure elucidation, but does require the production of diffraction quality crystals. We present here a system that speeds and simplifies the observation and analysis of the myriad of crystallization trials that are set up in order to produce crystals of data collection quality. Protein (or any other macromolecule) crystal growth involves screening crystallization space for conditions under which the protein forms large (100µm) single crystals. Protein crystal space is the collection of possible combinations of chemicals that may induce protein crystal growth, and is generally sampled by setting up 50-1000 trial experiments simultaneously. This space is huge, and spans hundreds of different chemicals, at varying concentrations and pH. The results from this battery of experiments are used to refine the crystallization conditions in second and subsequent rounds of crystallization. Crystallization trials are traditionally set up as vapor diffusion experiments, where a drop (0.5-5µl) of a concentrated protein solution is mixed with a similar quantity of crystallization cocktail, then equilibrated against a reservoir of the crystallization cocktail. Batch methods, where the protein and the cocktail are mixed, but not equili

A new sample changer system has been designed to rapidly transport activity from a heavy element production target chamber at the Lawrence Berkeley National Laboratory 88-Inch Cyclotron to a fission, α-particle, X-ray, and γ-ray detection site. This changer was specifically designed to help study the nuclear structure of isotopes involved in electron-capture-delayed fission decay with half-lives greater than 30 s. The system integrates a rotating wheel and a cycling piston to transport samples from the end of a gas transport capillary line to the detection site. The overall efficiency of the sample changer system was determined by running off-line experiments to determine the activity collection site efficiency and the detector efficiencies. Under the most favorable conditions, we calculated a relative He–KCl gas transport and collection efficiency of around 70%. Efficiencies were calculated by comparing the yield of 221Fr (half-life=4.8 min) at the sample changer collection site to the activity collected directly on a piece of glass filter paper.

We consider a theory of a scalar one-component field $\phi$ coupled to a scalar $N$-component field $\chi$. Using large $N$ techiques we calculate the effective potential in the leading order in $1/N$. We show that this is equivalent to a resummation of an infinite subclass of graphs in perturbation theory, which involve fluctuations of the $\chi$ field only. We study the temperature dependence of the expectation value of the $\phi$ field and the resulting first and second order phase transitions., Comment: 11 pages, LaTex, includes 5 uuencoded postscript figures, OUTP-94-11 P

The magnetoconductance of quantum dots at high magnetic fields has been studied experimentally and theoretically as a function of the quantum dot barrier height. It is found that even when the dot is not Coulomb blockaded, electron-electron interactions are required to explain the magnetoconductance oscillations.

We report the use of a lateral surface gate stripe bisecting a relatively large, high mobility ballistic electron cavity to examine geometry-induced weak localisation effects. Illumination and positive bias applied to the stripe gate are used to produce a controllable trajectory scrambling region within the cavity.

Short-channel effects in GaAs MESFETs are investigated. MESFETs were fabricated with gate lengths in the range of 40 to 300 nm with GaAs and AlGaAs buffer layers. The MESFETs were characterized by DC transconductance, output conductance, and subthreshold measurements. This work focuses on overcoming the short-channel effect of large output conductance by the inclusion of an AlGaAs buffer layer, and identifying the benefit the AlGaAs buffer affords for reducing subthreshold current, including the effect of drain-induced barrier lowering. The design yielded 300-nm gate-length MESFETs with excellent suppression of the major short-channel effects. >

We discuss magnetoconductance oscillations arising from transmission and reflection of current via edge states which are confined within lateral quantum dots by entrance and exit port barriers. An interplay of several resonant processes involving spin-resolved edge states determines the evolution of the oscillations as a function of the conductance of the barriers. © 1993 The American Physical Society.

The use of surface gates to define submicrometer-size dots incorporating quantum point contacts (QPC's) is proving profitable in investigating a number of effects including single electron effects and geometry-induced quantum interference. In these studies, characterization of the dots is essential. We report zero- and low-magnetic-field analysis of ballistic transmission through these structures and discuss the trajectories' interaction with the confining potential profiles. We also consider the implications of the component QPC's for reciprocity.

Quantum point contacts (QPCs), defined by surface gate technology, are increasingly featuring as basic building blocks of more sophisticated geometries such as coupled dot, single electron, and coherent wave devices. For many of its potential roles the electron density within the QPC needs to be known accurately as a function of the voltage applied to the split gates that define the QPC within the two-dimensional electron gas. A common characterization technique extracts the density from the positions of the conductance plateaus that result from the depopulation of edge states as the gate voltage is swept at high magnetic fields. We study the high current breakdown of these plateaus and investigate the nonlinear current–voltage characteristics for both split gate and continuous gate geometries. We demonstrate that the breakdown is not centred around the plateaus and that, unlike the breakdown of the quantum Hall effect, a forward propagation mechanism needs to be considered and indeed is the dominant process.

On a etudie l'interaction entre deux differents effets electroniques discrets dans les ilots quantiques. Ces deux effets sont l'effet de blocus coulombien et un nouveau processus d'effet tunnel resonnant qui se produit dans l'ilot lui-meme. Nous demontrons que les deux processus sont gouvernes par deux echelles d'energie differentes. Nous trouvons que des interactions electron-electron (non le spectre de niveaux d'energie d'un seul electron) sont requises pour expliquer les deux processus

We discuss the electronic transmission through lateral dots, featuring both the Aharonov-Bohm-type oscillations observed in high magnetic field sweeps and Coulomb blockade oscillations detected as a function of electron density. We focus on the interplay of these two effects and demonstrate two intrinsic features of submicron dot behavior-the manifestation of the Aharonov-Bohm oscillations in a resonant reflection mode and a novel regime characterized by the simultaneous observation and a commensurate relationship of the two effects

We investigate both low and high field magnetotransport through submicron quantum dots using a six-gate coupled dot structure. At low fields we have studied classical magnetic focusing and coherent effects in this confined geometry. At higher fields we have observed a new phenomenon, the resonant backscattering of an edge state modulated by zero-dimensional states. At the highest fields we do not observe oscillations associated with the zero-dimensional states. © 1992.

We report low field magnetoresistance measurements of two QPC systems. For a staggered pair of QPCs were separate the ballistic and non-ballistic contributions to the magneto-resistance and report new trends. For a quantum dot we investigate magnetic focusing and demonstrate its use as a probe of the carrier density within the dot.

We report magnetoresistance measurements on staggered quantum contacts in series. The enhanced conductance reveals interesting effects associated with the geometry of the structure and its collimation of the ballistic electrons. We are able to isolate the contributions of ballistic and non-ballistic trajectories to the conductance. We also show the system to be an interesting demonstration of the reciprocity theorem.

The effects of tree windthrow on soil properties and vegetation were studied in an area of rimu (Dacrydium cupressinum) forest on a dissected glacial outwash surface in Saltwater State Forest, South Westland, New Zealand. Tree windthrow and the resulting formation of surface pits and mounds caused a redirection of pedogenesis, particularly on relatively better-drained low ridges; there, the normal development of a gleyed yellow-brown earth profile was altered towards organic soils in the pits and podzolised yellow-brown earths on the windthrow mounds. In poorly drained backswamps, organic soils also formed in the pits, while gleying processes predominated in both the windthrow mound soil and the adjacent unmodified soil. The sequence of vegetation development was different on windthrow pits compared with mounds. Mounds were rapidly colonised by ground-cover plants, especially ferns and tree ferns. These were subsequently replaced by broadleaved trees, particularly kamahi (Weinmannia racemosa). Pi...

This paper describes a process to fabricate GaAs MESFETs with gate lengths in the range 270 to 30nm suitable for high frequency characterisation. Electron beam lithography was used to define all device levels on layers grown by molecular beam epitaxy (MBE). Processing included a dry etched mesa for isolation, low temperature annealed ohmic contacts, and a gate recess etch containing a wetting agent to improve etching uniformity. The MESFETs were characterised at DC and high frequency. 30nm gate length devices exhibited DC transconductances of up to 710mS/mm and unity gain cut off frequencies of up to 150GHz extrapolated at 6dB/octave from 20GHz.

The complex physiology of breathing in the newborn has important developmental and maturational aspects. Early in fetal life the respiratory system and controllers respond to intrauterine stimuli (PaCO2PaCO2, PaO2PaO2, and lung inflation). The complex network of control of breathing can be summarized into three basic components: (1) controllers, (2) effectors, and (3) sensors. At birth a multitude of inputs are responsible for initiation of rhythmic ventilation, and adaptation of the pulmonary circulation to extrauterine life. The normal physiology of breathing in the newborn is affected by posture, sleep state, and gestational age. Pathophysiological aspects of breathing in the newborn can be divided into: (1) fetal − pathologies that occur during fetal life and ultimately result in abnormal lung development, (2) immediate postnatal − events that occur primarily as a result of poor or abnormal transition to extrauterine life, and (3) neonatal − events occurring in the neonatal period that lead to intrinsic lung disease or deranged control of breathing such as apnea. This article emphasizes the general importance of understanding the influence of age, posture, sleep state, and maturation on breathing in the newborn, and provides a general overview of these. Paramount to the interpretation of normative and study data is the understanding of the influence of these factors.

Strategy definition for teams of multiple mobile robots with fewer human operators than robots is a continuing area of research. Before strategies can be defined, the medium upon which they are implemented must be understood. This paper describes the development of a hybrid multi-agent behavioral control architecture used to implement the strategies for game play in the RoboFlag environment. Additionally, the graphical-based human-robotic interface is described. A framework has been built upon which systematic evaluation of strategy definition components can be performed.

The culmination of the 2002 RoboFlag Summer Undergraduate Research Fellowship program, jointly operated between California Institute of Technology and Cornell University, was a final competition between two teams of three undergraduate researchers. After ten weeks of preparation, Team Pasadena defeated Team Ithaca in two of the three final games. This paper provides the detailed results of the competition, an analysis of the competition, and reviews the future work.

In this paper we describe MASC, a multiple agent supervisory control system which will provide a human supervisor with the capabilities to interact at various hierarchical levels with a multiple mobile agent system. This hierarchy of mediation allows the agents of the system to request assistance from the human when necessary. It also provides the supervisor with the ability to assume control of the agents when they enter a state from which they are incapable of self correction. We describe the levels of the mediation hierarchy, their implementations, and their system control implications. Our goal is to create a semi-autonomous system which successfully executes all feasible tasks. >

Corporations are facing the ever increasing demands to reduce the environmental impact from Semiconductor manufacturing. At the same time, the latest wafer designs require ever increasing purity of chemicals and processes. Many times these two requirements are contradictory, however, in the area of wet chemistry, both the reduction of environmental wastes and the improvement of chemical purity can be readily and cost effectively achieved through the use of on-site reclaim and reprocessing. Sulfuric acid, Hydrofluoric acid, and Isopropyl alcohol are leading chemicals for recycling due to their ultra-high purity requirements, large consumption volumes, high cost, waste created, and their disposal challenge. This paper is an overview of the technologies employed to enable reprocessing and includes several case studies to demonstrate the economic and environmental benefits of reprocessing.

We are developing a complex situational management application for non-steady state events. The domain in which we are working is polyester film base manufacturing. The complex situational management application is an expert system that monitors the non-steady state events and assists human operators with the event tasks. This application currently implements three event checklists and system monitoring logic that represent standard operating procedures for large, complex, film base machines.

We present the first demonstration of a nanostructural device with a central electrode (diameter ≊300 nm) which is contacted independently. This structure is used to create a quantum wire into which an ‘‘impurity’’ of variable size can be introduced. With additional confining gates the structure can also be used to create a quantum dot which can be converted continuously into a quantum ring. Experimental results of magnetoresistance in both low and high magnetic fields are presented which demonstrate the effect of introducing the artificial impurity to a quantum wire.

MESFETs with gate lengths in the range of 40 to 300 nm with GaAs and AlGaAs buffer layers were characterized by high-frequency transit-time measurements. The total carrier transit time is interpreted as being composed of an intrinsic part, a drain delay, and a channel charging delay. The drain field's effect on the geometry of the gate depletion region, and the injection of carriers into the buffer layer are used to describe the origin of these delays and their limiting effect on the high-frequency performance of sub-0.1- mu m gate-length MESFETs. >

Weak localization, a semiclassical process established in disordered systems, has recently been used as an experimental probe of the classical dynamics of ballistic cavities. Through a systematic study of the classical and quantum behaviour of three ballistic cavities featuring large width to length aspect ratios, we highlight the important role of the entrance and exit leads. We present a novel ballistic weak localization process in which the contributing classical trajectories pass directly between the entrance and exit leads and are not shaped by the walls of the cavity but purely by the profiles of the leads. This demonstration of a small section of a cavity supporting a `local' weak localization process has important implications for studies which relate cavity geometry to the dynamics it supports.

The appeal of the lateral surface gate technique lies in the ability to tune the device through application of variable gate bias. We apply positive bias to a 250-nm-wide continuous gate, or stripe, defined above the two-dimensional electron gas of an ${\mathrm{Al}}_{\mathit{x}}$${\mathrm{Ga}}_{1\mathrm{\ensuremath{-}}\mathit{x}}$As/GaAs heterostructure. Following pulsed light emitting diode illumination, inhomogeneities in the region shielded by the stripe can be annealed by tuning the positive bias. We employ this technique to introduce trajectory scrambling events into a ballistic-electron cavity. Through a systematic study of the low-field magnetoresistance of the cavity as a function of positive stripe bias (tuning the inhomogeneities) and temperature (control of electron phase coherence), we examine the interplay between geometry-induced weak localization and classical transport phenomena. In contrast to other recent observations of weak localization in the ballistic regime, our cavity is relatively large (1.8\ifmmode\times\else\texttimes\fi{}30 \ensuremath{\mu}${\mathrm{m}}^{2}$) and the trajectory loops are defined, not by the confining walls of the cavity, but by the profile of the exit port.

A pair of Quantum Point Contacts separated by a continuous barrier have been fabricated using the surface gate technique. Transport measurements for each component of this system and for various combinations have shown both additive and non-additive behaviour. The results are explained by a combination of reflection by the barrier of electrons collimated by the Quantum Point Contacts and transport by diffusion across the barrier.

The design of surface gate patterns, used to define nanostructurcs in AlGaAs GaAs heterostructures, is greatly enhanced by the possibility of establishing electrical contact to, and independently biasing, a 100 nm wide isolated gate. We describe the fabrication of a multi-level metallisation architecture which can be used to contact a nanoscale central gate and monitor the transition from a quantum dot to ring geometry. We employ geometry induced quantum interference effects as a novel low temperature characterisation tool and report experiments in which the central electrode acts as an artificial impurity. © 1994.

The author highlights current applications for imaging and image analysis as used in the printed circuit board (PCB) assembly process and suggests areas of needed improvement in both acquisition and analysis. Imaging is used on PCB assembly lines to meet the demanding placement requirements of the modern components, to identify proper component and orientation, to confirm the proper application of solder paste, to verify soldering, and to test the final assembly. Current imaging techniques from ultrasound, visual, infrared, laser, and X-ray all need to improve to keep up with the demands from the marketplace. The discussion of imaging techniques is restricted to two-dimensional spatial imaging with the third dimension typically representing other information, such as height, temperature, thickness, color, or position. Better price performance is needed for future growth of bond electronics assembly and for vision. >

Electrical-transport measurements were performed on a system consisting of two quantum point contacts (QPCs) in series, where one of the point contacts exhibited low-frequency telegraph noise due to single-impurity effects. We show this system to be ideal for the study of equilibration between the edge states that form at high magnetic fields. We investigate both the adiabatic and nonadiabatic regimes and show that in the transitional magnetic-field range the conductance is compatible with a complete equilibration but between a limited number of edge states only. We also discuss the equivalent experiment at zero field, where one can study the effect of the potential fluctuations on the collimation of the ballistic electrons. In addition, we confirm the observation of 4e2/h quantization in the conductance of a wide QPC. © 1992 The American Physical Society.

Cytosolic and organellar free Ca2+ concentrations are very dynamic; they are often extremely localized and hard to measure. To overcome this problem we have constructed new fluorescent indicators for Ca2+ that are genetically encoded without cofactors and are targetable to specific intracellular locations.Green fluorescent protein (GFP) is a spontaneously fluorescent protein from the jelly fish Aequorea victoria. Its cDNA can be concatenated with those encoding many other proteins, and the resulting fusion proteins are usually fluorescent and often preserve the biochemical functions and cellular localizations of the partner proteins. Mutagenesis has produced GFP mutants with shifted wavelengths of excitation or emission that can serve as donors and acceptors for fluorescence resonance energy transfer (FRET).Our new indicators consist of tandem fusions of a blue- or cyan-emitting mutant of GFP, calmodulin (CaM), the calmodulin-binding peptide Ml3, and an enhanced green- or yellow-emitting GFP. Binding of Ca2+ makes calmodulin wrap around the Ml3 domain, increasing the FRET between the flanking GFPs (Fig. 1).

We performed pelvic ultrasound assessment in 104 patients with Turner syndrome aged 0.2 to 17.4 years; 69 had the 45,X karyotype and 35 had variant karyotypes. Ovarian appearances were classified as "streak" (n = 70, including 30 patients in whom no ovary could be seen) or "nonstreak" (n = 34). The nonstreak ovaries ranged from small glands, sometimes containing minute cysts, to ovaries indistinguishable from those which are normal for age. Nonstreak ovaries retained a range of function, as evidenced in some cases by spontaneous breast development and uterine enlargement. The proportion of nonstreak ovaries followed a U-shaped pattern, with a nadir from 4 to 10 years; this follows the known biphasic pattern of luteinizing hormone and follicle-stimulating hormone secretion. Only those patients with karyotype variants in which the long arm of the X chromosome was retained fared better than those with the 45,X karyotype.

The benefit of two instructional strategies: adaptive training and part training in teaching complex perceptual motor skills was evaluated. One method was the part training method, where a subject practiced on essential subtasks before performing the whole task. The other method was adaptive training, where the time pressure of the task was continually adjusted to conform to the subject's performance level until his performance was sufficient to handle the ultimate task difficulty. The task was a computer-controlled video game, developed for research purposes. The task was challenging and proficiency could be achieved only through significant amount of practice. The results found the part training regime superior to all others. The two adaptive training regimes brought mixed results, with one group superior and one equal to a control group. Negative transfer from the slow to the fast version of the game was evident, and may be the reason for the lack of clear advantage to the adaptive regimes.

A postal survey of typeface preference is described. The survey was designed to help in the choice of typeface to be used for the internal technical Reports produced by the Post Office Research Department. Type setting for these Reports is carried out using an IBM Selectric Composer for which seven typefaces suitable for reports are available. One hundred and twenty-five people who regularly receive copies of these Reports and 57 Trainee Technicians (Apprentices) were asked to arrange these seven typefaces in order of preference and record this ranking on a response sheet. About 85% of both groups returned response sheets for statistical analysis. The results showed a significant preference for three of the typefaces: Press Roman, Theme and Univers. Of these, Press Roman is used for the text of Research Department Reports and Univers is used on diagrams and tables.

The loss of total and organic phosphorus and the transformations of inorganic phosphorus fractions were investigated in a chrono-toposequence of strongly weathered and leached soils formed from granite. Over 80% of the total phosphorus originally present was lost from the system during the period of soil development studied. Non-occluded and occluded phosphorus showed a regular, and residual phosphorus an irregular, overall decline in absolute profile quantity with increasing soil development (i.e. increasing weathering and leaching). The proportion of non-occluded phosphorus in the profile declined asymptotically whereas residual phosphorus increased conversely to non-occluded phosphorus and ranged from 58% to 72% of total inorganic phosphorus in the most strongly developed profiles. Proportions of occluded phosphorus increased with increasing soil development. The relative rates of decline of the inorganic phosphorus fractions and forms were shown to be in the order: acid-extractable CaP > non-occluded P > occluded P > residual P. The final profile in the sequence is considered to represent a terminal steady-state system in which small losses of phosphorus from the system are balanced by gains of phosphorus from the atmosphere. The nature and extent of the vegetation on the sequence profiles was linked with declining acid-extractable CaP and non-occluded phosphorus contents. The tendency towards a heath-type vegetation on the later profiles of the sequence leads to a decline in many properties associated with the organic cycle, including total soil nitrogen, oxidisable carbon, and cation-exchange capacity. Declines in profile weights of several other soil properties were also observed. These included total soil calcium, magnesium, potassium, aluminium, iron, and profile clay content. In many cases the observed declines followed an asymptotic path. The declines were attributed to the completion of weathering of stones and gravels in the later profiles of the sequence whereupon no fresh minerals enter the pedogenetic process.

A chrono-toposequence of five soils formed in strongly weathered granite in the South Island of New Zealand was described on the basis of soil profile morphology, landscape position, and the degree of weathering of the underlying granite. The sequence contains five progressively younger soils on increasing slopes from crest to backslope formed in a Parent Material of originally uniform mineralogical and chemical composition as Parent Rock under a uniform climate and vegetation. All profiles of the sequence are strongly weathered and leached with the final member of the sequence being considered to represent a terminal steady-state system. Changes in a number of chemical and physical soil properties were described with the increasing soil development (i.e. increasing weathering and leaching) represented in the sequence profiles. Profile soil weights ( 2 mm) to fines was completed. An initial increase in profile silt and clay content was followed by a decline in both fractions with a corresponding increase in the sand fraction. Proportions of kaolin/metahalloysite initially increased and 2:1–2:2 Al intergrades decreased, but the final three sequence profiles had similar clay mineralogies with kaolin/metahalloysite being the main component. Profile weights of oxidisable carbon and total nitrogen followed an exponential decline after an initial increase between the first two sequence profiles. Profile cation-exchange capacity, total exchangeable bases, percent base saturation, and exchangeable cations showed no trends with increasing soil development. Depth-gradients of these parameters together with oxidisable carbon and total nitrogen became less pronounced, with the apparent tendency towards a steady-state system in the final sequence profile. Multiple regression analysis indicated that oxidisable carbon was the main contributing factor to cation-exchange capacity followed by clay content. Profile weights of total calcium and potassium were closely correlated and showed an approximately exponential decline with increasing soil development, whereas total magnesium showed a relatively linear decline. Total aluminium and iron both showed an initial increase and then declined. The relative rates of loss of the five total elements studied were in the order: Ca > Mg > K, Fe > Al.

Track response of polymers is now known to depend on the temperature of the detector during passage of the ionising particle (the registration temperature effect). This has serious consequences for cosmic ray composition studies carried out in earth orbit or on high altitude balloons. Further studies are reported for Lexan, plain CR-39 and doped CR-39 exposed to 245 MeV/N Fe ions. It was found that the relative signal strengths continue to increase down to -137°C, the minimum temperature employed in this experiment. The stack temperatures were cycled between 20°C and -137°C but no evidence of a hysteresis effect. was observed.

Methods were developed for the microfractionation and analysis of the proteins of duodenal fluid. After separation by paper electrophoresis, the major proteins and mucoproteins were determined by chromogen development and scan photometry. Fifteen different proteins and mucoproteins were recognized in the duodenal fluids of 19 subjects. Nine of the most prominent of these, 5 proteins and 4 mucoproteins, were estimated quantitatively. Marked differences were observed between cystic fibrosis and control subjects in regard to the content of some of these substances in their duodenal fluids.

Volume II comprises three appendices: reduced logging data from the field trips; samples of other output formats utilized by the data management software; and cost/benefit summaries for the field trips in 1978.

SR 4233 (3-amino-1,2,4-benzotriazine 1,4-dioxide) is a bioreductive agent that selectively kills and radiosensitizes hypoxic mammalian cells in vitro and murine tumors in vivo. In an attempt to better understand the mechanism of action of the drug, and to determine whether a superior analog may exist, 15 benzotriazine-di-N-oxide analogs of SR 4233 have been evaluated to date for the following properties: hypoxic and aerobic toxicity toward CHO cells in vitro, drug-induced stimulation of oxygen consumption by incubation with respiration-inhibited cells, and acute LD50 evaluated in BALB/c mice. We noted several correlations between these biological properties of the drugs and some of their physicochemical characteristics. Both the hypoxic cytotoxicity and stimulation of oxygen consumption by respiration-inhibited cells were positively correlated with E1/2, the polarographic half-wave reduction potential, and a measure of electron affinity. The air-to-nitrogen differential cytotoxicity reached a maximum (corresponding to SR 4233) and then declined with increasing E1/2. The acute LD50 of each analog in mice decreased with increasing E1/2. One new compound, SR 4482, was found to be more toxic to hypoxic cells in vitro, but less toxic to mice, than SR 4233. It is similar in structure to SR 4233, but lacks any substituent in the 3-position of the triazine ring. This promising drug may represent a member of a new subseries of 1,2,4-benzotriazines with different structure-activity relationships.

This report summarizes information concerning the decommissioning of the Elk River Reactor. Decommissioning data from available documents were input into a computerized data-handling system in a manner that permits specific information to be readily retrieved. The information is in a form that assists the Nuclear Regulatory Commission in its assessment of decommissioning alternatives and ALARA methods for future decommissionings projects. Samples of computer reports are included in the report. Decommissioning of other reactors, including NRC reference decommissioning studies, will be described in similar reports.

Primary polycythaemia (PP), idiopathic myelofibrosis (MF), essential thrombocythaemia (ET) and chronic granulocytic or myeloid leukaemia (CGL) are clonal disorders of the pluripotent haemopoietic stem cells. We have studied granulocyte, megakaryocyte and erythroid progenitors from the peripheral blood of 7 patients with PP, 9 with ET, 19 with MF and 6 with CGL in order to characterise similarities and differences at the committed progenitor cell level. Spontaneous megakaryocytic and erythrocytic growth was characteristic of MF, PP and ET but was not seen in CGL. Circulating erythroid (BFU-E) and granulocyte/macrophage (CFU-GM) progenitors were markedly increased in MF and CGL, less raised in ET and closest to normal in PP. Erythropoietin-independent erythroid bursts (EIBFU-E) grew from the blood of patients with MF, PP and ET but spontaneous growth of megakaryocytes occurred in only MF and ET. These results suggest a progression of increasing abnormality from PP, where EIBFU-E occurred with relatively normal numbers of circulating progenitors, to ET where both EIBFU-E and megakaryocyte precursors regularly occur with elevated numbers of progenitors, to MF where spontaneous BFU-E, CFU-Mk and CFU-GM occur at high levels.

Duodenal fluids from cystic fibrosis and control subjects were analyzed for proteins and mucoproteins by quantitative paper-strip electrophoresis. Prominent quantitative differences were found among the nine major proteins and mucoproteins of the two subject groups. Three proteins and two mucoproteins did not differ between the groups, but the other two proteins and two mucoproteins did differ. The cystic fibrosis subjects had: (I) a relative excess of substances designated as mucoprotein O and protein C5; and (2) a relative deficiency of mucoprotein C4 and protein O. It is notable that cystic fibrosis is characterized by a quantitative difference pattern rather than by a qualitative difference.