We describe a measurement of the ratio of the cross sections times branching fractions of the (ProQuest: Formulae and/or non-USASCII text omitted) meson in the decay mode (ProQuest: ... denotes ...formulae and/or non-USASCII text omitted) meson in the decay mode B super(+)arrowrightJ/psiK super(+) in proton-antiproton collisions at center-of-mass energy radicals=1.96TeV. The measurement is based on the complete CDF Run II data set, which comes from an integrated luminosity of 8.7fb super(-1). The ratio of the production cross sections times branching fractions for <disclaimer#3 /> and B super(+) mesons with momentum transverse to the beam greater than 6GeV/c and rapidity magnitude smaller than 0.6 is 0.211+ or -0.012(stat)... . Using the known B+arrowrightJ/psiK super(+) branching fraction, the known B super(+) production cross section, and a selection of the predicted ... arrowrightJ/psimu super(+)nu branching fractions, the range for the total ... production cross section is estimated.
Wind-powered recreational (WPR) activities are increasingly popular and occur in many areas of high conservation value. Possible impacts are poorly understood; existing reviews do not generally ...include recent widespread forms of WPR or have narrow taxonomic/ecological scopes. We identify the coastal ecosystems/wildlife that may interact with WPR and potential impacts: a) noise, movement and other stimuli, b) direct contact, c) disruption of substrates, and d) transport of pests. Almost all available evidence on impacts involves coastal birdlife, specifically their escape responses. Most studies are a) non-peer reviewed, largely anecdotal or otherwise limited in scope and b) from temperate locations. Sustainable use of WPR craft is required despite the prevailing information gaps. We suggest a precautionary, proactive approach which likely requires a combination of site-based management, plus policy and education initiatives.
We report a measurement of single top quark production in proton-antiproton collisions at a center-of-mass energy of s=1.96TeV using a data set corresponding to 7.5fb super(-1) of integrated ...luminosity collected by the Collider Detector at Fermilab. We select events consistent with the single top quark decay process tarrowrightWbscriptlnub by requiring the presence of an electron or muon, a large imbalance of transverse momentum indicating the presence of a neutrino, and two or three jets including at least one originating from a bottom quark. An artificial neural network is used to discriminate the signal from backgrounds. We measure a single top quark production cross section of (ProQuest: Formulae and/or non-USASCII text omitted) pb and set a lower limit on the magnitude of the coupling between the top quark and bottom quark V sub(t)b0.78 at the 95% credibility level.
Here, a search for the exotic meson X(5568) decaying into the B$0\atop{s}$π± final state is performed using data corresponding to 9.6 fb-1 from $p\bar{p}$ collisions at $\sqrt{s}$ = 1960 GeV recorded ...by the Collider Detector at Fermilab. No evidence for this state is found and an upper limit of 6.7% at the 95% confidence level is set on the fraction of B$0\atop{s}$ produced through the X(5568)→B$0\atop{s}$π± process.
1. The allocation of resources among various reproductive structures and functions can suggest the relative importance of past selective pressures in moulding reproductive patterns. 2. To determine ...how male and female plants of the dioecious shrub Oemleria cerasiformis differ in allocation to reproductive functions, biomass was partitioned among reproductive structures for 20 plants of each sex. 3. Structures contributing to pollinator attraction (petals and hypanthium) were heavier in males than in females. In males, these structures constituted 63% of total reproductive biomass; inflorescence stems and bracts constituted 28%, and the androecium only 9%. In females at flowering, petals and hypanthium constituted 50% of reproductive biomass, inflorescence stems and bracts 37%, and the gynoecium 13%. 4. In females, fruits constituted 87% of the total reproductive biomass at average fruit set (13.7% of pistils). Even with the lowest observed fruit set (4% of pistils), fruit comprised 75% of reproductive biomass overall, and pollinator attraction no more than 4%. Fruit biomass was distributed about equally between pulp (offspring dispersal) and stone (offspring provisioning and protection). A flower can produce up to 150 times its own weight in fruit, thus fruit set is the main factor determining how biomass is distributed among reproductive structures in females. 5. These data support the view that the primary factors influencing the evolution of reproductive allocation are, in males, pollen limitation, and in females, the necessity of provisioning and dispersing offspring.
The data processing model for the CDF experiment is described. Data processing reconstructs events from parallel data streams taken with different combinations of physics event triggers and further ...splits the events into datasets of specialised physics interests. The design of the processing control system makes strict requirements on bookkeeping records, which trace the status of data files and event contents during processing and storage. The computing architecture was updated to meet the mass data flow of the Run II data collection, recently upgraded to a maximum rate of 40 MByte/sec. The data processing facility consists of a large cluster of Linux computers with data movement managed by the CDF data handling system to a multi-petaByte Enstore tape library. The latest processing cycle has achieved a stable speed of 35 MByte/sec (3 TByte/day). It can be readily scaled by increasing CPU and data-handling capacity as required
1 Seedling banks, made up of small individuals of tree species in the understorey, are an important component of many forests. 2 We collected and aged 4992 individuals up to 1.3 m in height of Abies ...amabilis, Chamaecyparis nootkatensis, Tsuga mertensiana and T. heterophylla from the seedling bank of an ancient forest in coastal British Columbia, Canada. 3 Growth was extremely slow. Some individuals < 1.3 m tall were more than 150 years old. Very few plants attained an above-ground stem length of 1 m in less than 100 years. Regressions of above-ground stem length vs. age indicated that net terminal growth averaged only c. 2 mm per year up to age 50. 4 Although species differed in age structure, all had slow-growing, persistent individuals. 5 These trees can be considered to be adapted to survive for long periods under the high levels of biotically induced stress of the forest understorey. Such a high potential for stress tolerance in forest trees presents a challenge for the classification of life histories. 6 The seedling bank contributes to the canopy composition in ancient forests. Forest ecology must consider not only tree regeneration in relation to disturbance, but also the dynamics of tree populations under intact canopies.
Forest encroachment threatens the biological diversity of grasslands globally. Positive feedbacks can reinforce the process, affecting soils and ground vegetation, ultimately leading to replacement ...of grassland by forest species. We tested whether restoration treatments (tree removal, with or without fire) reversed effects of nearly two centuries of encroachment by
Abies grandis
and
Pinus contorta
into dry, montane meadows in the Cascade Range, Oregon, USA. In nine, 1-ha plots containing a patchy mosaic of meadow openings and forests of varying age (20 to >140 yr), we compared three treatments affecting the ground vegetation: control (no trees removed), unburned (trees removed, slash burned in piles leaving 90% of the area unburned), and burned (trees removed, slash broadcast burned). We quantified changes over 3-4 years in soils, abundance and richness of species with differing habitat associations (meadow, forest, and ruderal), and recruitment of conifers. Except for a transient increase in available N (especially in burn scars), effects of burning on soils were minimal due, in part, to mixing by gophers. Tree removal greatly benefited meadow species at the expense of forest herbs. Cover and richness of meadow species increased by 47% and 38% of initial values in unburned plots, but changed minimally in burned plots. In contrast, cover and richness of forest herbs declined by 44% and 26% in unburned plots and by 79% and 58% in burned plots. Ruderal species and conifer seedlings were uncommon in both treatments. Although vegetation was consumed beneath burn piles, meadow species recovered significantly after three years. Long-term tree presence did not preclude recovery of meadow species; in fact, colonization was greater in older than in younger forests. In sum, temporal trends were positive for most indicators, suggesting strong potential for restoration. Contrary to conventional wisdom, tree removal without fire may be sufficient to shift the balance from forest to meadow species. In meadows characterized by historically infrequent fire, small-scale disturbances and competitive interactions may be more critical to ecosystem maintenance and restoration. Managers facing the worldwide phenomenon of tree invasion should critically evaluate the ecological vs. operational need for fire in ecosystem restoration.
Ground-foraging birds of temperate woodlands of southern Australia are prominent among bird species considered to be susceptible to population decline. We examined the foraging ecology, including ...foraging substrates, actions and heights, of 13 ground-foraging species at four woodland sites in northern Victoria. Nine species are regarded as declining in southern Australia and four are considered common. Ten foraging substrates were identified, of which leaf-litter (54% of observations) and bare ground (17%) were most frequently used. In all woodland sites, litter was used more frequently than expected from its proportional cover. Bare ground was frequently used as a substrate by individual species, and fallen timber and grass were important for some species. Most species were generalists in their use of substrates. Six foraging actions were observed, of which gleaning and pouncing were most frequently recorded. All species foraged close to the ground and four foraged almost entirely at ground level. For pouncing birds, dead branches and fallen timber were the most important launch substrates from which pouncing actions were initiated. Eight of the 13 species differed in some aspect of their foraging ecology between woodland sites, especially in relation to the use of substrates (seven species). Fewer species (four) displayed differences in foraging ecology between seasons, with the greatest seasonal variation being in use of foraging substrates (three species). Overall, no significant differences were evident in the foraging ecologies of common and declining species. Species in both groups encompassed a wide range of foraging behaviours. Owing to this range in foraging ecology, the conservation of diverse assemblages of ground-foraging birds requires the maintenance of heterogeneous ground layers and careful management of disturbance processes.
(1) One- to six-year-old natural seedlings of Abies amabilis, Tsuga heterophylla and T. mertensiana were collected from 15-cm-deep volcanic tephra deposited beneath a surviving tree canopy during the ...1980 eruption of Mount St Helens, Washington, U.S.A. Seedling dimensions and architecture were measured and dry weights of leaves, stem and roots determined as loss-on-ignition. (2) Abies seedlings were heavier than Tsuga initially, with deeper and more-complex roots; however, biomasses of Abies and Tsuga seedlings became more similar with time. Height above the cotyledons was similar in older seedlings of the two genera, but branching began earlier in Tsuga than in Abies. (3) Tsuga had a higher relative growth rate than Abies, with both greater leaf-biomass ratio and greater assimilation efficiency. Leaf allocation of Abies exceeded that of Tsuga at first, but eventually became less than that of Tsuga. (4) Most measures of size decreased for Tsuga as canopy cover increased; for Abies, only the amount of root branching declined. As litter increased, root dimensions of both genera declined, but biomass of Tsuga increased whereas that of Abies decreased. Abies seemed less affected by both shade and limited soil moisture than Tsuga. (5) Seedling growth rate and allocation appear to be important in determining the types of micro-environments in which the two genera can establish, and thus may affect long-term stand dynamics. Root characteristics differentiated taxa more clearly than those of shoots.
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