Forty-eight representatives of 12 tribes attributed to the subfamily Pooideae s.l. of grasses (Monocots) have been studied by sequencing the more variable 3' end of the chloroplast ndhF gene. Six ...representatives from 5 different tribes of Poaceae (Oryzeae, Streptogyneae, Bambuseae, Arundineae, Phareae) and from Joinvilleaceae were used as outgroups. Phylogenetic analyses of the data render a monophyletic Pooideae clade and provide an evolutionary hypothesis for all its tribes (Poeae, Aveneae, Bromeae, Triticeae, Brachypodieae, Meliceae, Stipeae, Lygeae, Nardeae, Diarrheneae, Brachyelytreae, Phaenospermatae). The subfamily is composed of two subsets of tribes, a basal group that includes six old lineages or satellite tribes, in which Brachyelytreae is the first diverging branch followed by the Lygeae/Nardeae clade, and a group of six more recently evolved tribes (Pooideae s.s.), in which the divergence of Diarrheneae antedates that of Brachypodieae, sister group to the "core pooids." The character changes found within the sequenced nucleotide positions of the ndhF gene also have proven to be informative at lower hierarchical levels (genus and species) for some tribes.
The three-dimensional structure of the chemotactic peptide N-formyl-L-Met-L-Leu-L-Phe-OH was determined by using solid-state NMR (SSNMR). The set of SSNMR data consisted of 1613C-15N distances and 18 ...torsion angle constraints (on 10 angles), recorded from uniformly13C,15N- and15N-labeled samples. The peptide's structure was calculated by means of simulated annealing and a newly developed protocol that ensures that all of conformational space, consistent with the structural constraints, is searched completely. The result is a high-quality structure of a molecule that has thus far not been amenable to single-crystal diffraction studies. The extensions of the SSNMR techniques and computational methods to larger systems appear promising.
The Unified Radio and Plasma Wave (URAP) experiment has produced new observations of the Jupiter environment, owing to the unique capabilities of the instrument and the traversal of high Jovian ...latitudes. Broad-band continuum radio emission from Jupiter and in situ plasma waves have proved valuable in delineating the magnetospheric boundaries. Simultaneous measurements of electric and magnetic wave fields have yielded new evidence of whistler-mode radiation within the magnetosphere. Observations of auroral-like hiss provided evidence of a Jovian cusp. The source direction and polarization capabilities of URAP have demonstrated that the outer region of the lo plasma torus supported at least five separate radio sources that reoccurred during successive rotations with a measurable corotation lag. Thermal noise measurements of the lo torus densities yielded values in the densest portion that are similar to models suggested on the basis of Voyager observations of 13 years ago. The URAP measurements also suggest complex beaming and polarization characteristics of Jovian radio components. In addition, a new class of kilometer-wavelength striated Jovian bursts has been observed.
Recent cladistic analyses are revealing the phylogeny of flowering plants in increasing detail, and there is support for the monophyly of many major groups above the family level. With many elements ...of the major branching sequence of phylogeny established, a revised suprafamilial classification of flowering plants becomes both feasible and desirable. Here we present a classification of 462 flowering plant families in 40 putatively monophyletic orders and a small number of monophyletic, informal higher groups. The latter are the monocots, commelinoids, eudicots, core eudicots, rosids including eurosids I and II, and asterids including euasterids I and II. Under these informal groups there are also listed a number of families without assignment to order. At the end of the system is an additional list of families of uncertain position for which no firm data exist regarding placement anywhere within the system.
A series of experiments are reported which serve as milestones in the development of the MPFD technology. Each test involved reactor pulsing, a controlled power excursion that results from rapid ...removal of control rods. During a reactor pulse, the power level increases by several orders of magnitude in a fraction of a second resulting from prompt-critical neutron generation in the core. Preliminary reactor pulse testing was conducted at the Kansas State University TRIGA Mk. II nuclear reactor (KSU). The MPFD was used to track reactor pulses of 2.77 and 2.50 worth of reactivity insertion with measured Full Widths at Half Maximum (FWHM) of 13.2 and 16.1 ms compared to theoretical FWHM of 12.2 and 14.4 ms using the Fuchs-Nordheim Model. At the University of Wisconsin Madison Nuclear Reactor (UWNR), a set of 7 detectors, each with 4 independent chambers was deployed as part of the NEUP-NEAMS collaboration between UWNR and KSU. Nine of the time-synchronized chambers were able to track six reactor pulses to provide a spatial map of neutron flux. Finally, a two-chamber MPFD was deployed inside the Idaho National Laboratory Transient Reactor Test Facility (TREAT) reactor core and successfully monitored the power excursion of a 15 GW reactor pulse with an estimated neutron flux of ~10 18 n/cm2/s. These preliminary tests highlight the multi-faceted capability of the MPFD as an instrument in different research and power reactors.
The OPAL silicon-tungsten calorimeter front end electronics Anderson, B.E.; Anderson, K.; Charalambous, A. ...
IEEE Transactions on Nuclear Science (Institute of Electrical and Electronics Engineers); (United States),
08/1994, Letnik:
41, Številka:
4
Journal Article, Conference Proceeding
Recenzirano
Odprti dostop
A pair of small angle silicon-tungsten (Si-W) calorimeters has been built to measure the luminosity to a precision better than 0.1% in the OPAL experiment at the Large Electron Positron (LEP) ...collider at CERN near Geneva. Each calorimeter contains 19 layers of tungsten (W) plates and silicon (Si) detectors, corresponding to a total of 22 radiation lengths, sampled by about 1 m/sup 2/ of detectors divided into 304/spl times/64 independently read out channels. A complete electronics system has been developed, from the preamplifier up to the VME read out and control interface. It includes a fast trigger based on analogue sums. This paper describes how a large number of channels have been implemented in a dense environment, thanks to the use of ASIC's directly bonded on the detector.< >
Surgical therapies for symptomatic bladder outlet obstruction (BOO) due to benign prostatic hyperplasia (BPH) are many, and vary from minimally invasive office based to high-cost operative ...approaches. This Guideline presents effective evidence-based surgical management of male lower urinary tract symptoms secondary/attributed to BPH (LUTS/BPH). See accompanying algorithm for a detailed summary of procedures (figureFigure: see text).
The Minnesota Evidence Review Team searched Ovid MEDLINE, Embase, Cochrane Library, and AHRQ databases to identify eligible studies published between January 2007 and September 2020, which includes the initial publication (2018) and amendments (2019, 2020). The Team also reviewed articles identified by Guideline Panel Members. When sufficient evidence existed, the body of evidence was assigned a strength rating of A (high), B (moderate), or C (low) for support of Strong, Moderate, or Conditional Recommendations. In the absence of sufficient evidence, information is provided as Clinical Principles and Expert Opinions (tableTable: see text).
Twenty-four guideline statements pertinent to pre-operative and surgical management were developed. Appropriate levels of evidence and supporting text were created to direct urologic providers towards suitable and safe operative interventions for individual patient characteristics. A re-treatment section was created to direct attention to longevity and outcomes with individual approaches to help guide patient counselling and therapeutic decisions.
Pre-operative and surgical management of BPH requires attention to individual patient characteristics and procedural risk. Clinicians should adhere to recommendations and familiarize themselves with criteria that yields the highest likelihood of surgical success when choosing a particular approach for a particular patient.
At solar minimum, the solar wind is observed at high solar latitudes as a predominantly fast (> 500 km/s), highly Alfvenic, rarefied stream of plasma originating deep within coronal holes, while near ...the ecliptic plane it is interspersed with a more variable slow (< 500 kms) wind. The precise origins of the slow wind streams are less certain, with theories and observations supporting sources from the tips of helmet streamers, interchange reconnection near coronal hole boundaries, and origins within coronal holes with highly diverging magnetic fields. The heating mechanism required to drive the solar wind is also an open question and candidate mechanisms include Alfven wave turbulence, heating by reconnection in nanoflares, ion cyclotron wave heating and acceleration by thermal gradients1. At 1 au, the wind is mixed and evolved and much of the diagnostic structure of these sources and processes has been lost. Here we present new measurements from Parker Solar Probe at 36 to 54 solar radii that show clear evidence of slow, Alfvenic solar wind emerging from a small equatorial coronal hole. The measured magnetic field exhibits patches of large, intermittent reversals associated with jets of plasma and enhanced Poynting flux and interspersed in a smoother and less turbulent flow with near-radial magnetic field. Furthermore, plasma wave measurements suggest electron and ion velocity-space micro-instabilities that have been identified with plasma heating and thermalization processes. Our measurements suggest an impulsive mechanism associated with solar wind energization and a heating role for micro-instabilities and provide strong evidence for low latitude coronal holes as a significant contribution to the source of the slow solar wind.
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