4,694 research outputs found
Macadamia Felted Coccid, Eriococcus ironsidei: Biology and Life Cycle in Hawaii
The life cycle and general biology of Eriococcus ironsidei were ob- served in the field and under laboratory conditions. We provide data on duration of developmental stages, fecundity, and longevity of the insects. The female can be found in high numbers on branches of macadamia nut tress while the males mostly colonize the leaves. The average duration of time to complete metamorphosis varied between the sexes. Females took 32 days and males 16 days after hatching from eggs to reach the adult stage. Females produced up to 97 eggs (mean of 36.7) and were capable of producing eggs for over 50 days under laboratory conditions
Use of Living and Dying Mulches as Barriers to Protect Zucchini from Insect-caused Viruses and Phytotoxemias
Cucurbit crops are affected by several insect-vectored virus disorders and phytotoxemias resulting from insect feeding. Results of a field experiment with zucchini in monoculture or interplanted with either a white clover living mulch or a buckwheat dying mulch are reported. The living mulch appeared more suitable in reducing aphid numbers and associated problems in the crop
Probing the circulation of ring-shaped Bose-Einstein condensates
This paper reports the results of a theoretical and experimental study of how
the initial circulation of ring-shaped Bose-Einstein condensates (BECs) can be
probed by time-of-flight (TOF) images. We have studied theoretically the
dynamics of a BEC after release from a toroidal trap potential by solving the
3D Gross-Pitaevskii (GP) equation. The trap and condensate characteristics
matched those of a recent experiment. The circulation, experimentally imparted
to the condensate by stirring, was simulated theoretically by imprinting a
linear azimuthal phase on the initial condensate wave function. The theoretical
TOF images were in good agreement with the experimental data. We find that upon
release the dynamics of the ring--shaped condensate proceeds in two distinct
phases. First, the condensate expands rapidly inward, filling in the initial
hole until it reaches a minimum radius that depends on the initial circulation.
In the second phase, the density at the inner radius increases to a maximum
after which the hole radius begins slowly to expand. During this second phase a
series of concentric rings appears due to the interference of ingoing and
outgoing matter waves from the inner radius. The results of the GP equation
predict that the hole area is a quadratic function of the initial circulation
when the condensate is released directly from the trap in which it was stirred
and is a linear function of the circulation if the trap is relaxed before
release. These scalings matched the data. Thus, hole size after TOF can be used
as a reliable probe of initial condensate circulation. This connection between
circulation and hole size after TOF will facilitate future studies of
atomtronic systems that are implemented in ultracold quantum gases.Comment: 9 pages, 9 figure
The eyes have it?-intra- and inter-observer reproducibility of the PD-L1 companion diagnostic assay
No abstract available
Contribution of Insect Pollination to Macadamia integrifolia Production in Hawaii
The honeybee, Apis mellifera, is commonly accepted to be an important pollinator in many agricultural crop systems in Hawaii. However, specific details on the importance of A. mellifera, along with other insect visitors have not been determined for macadamia nut orchards in Hawaii. Reductions in feral honeybee populations in Hawaii attributable to invasions by varroa mites (Varroa destruc- tor) and small hive beetle (Aethina tumida) have resulted in growers becoming dependent on managed bees, requiring increased understanding of the role they play as pollinators. Several parameters determining the contributions of insect pollinators in macadamia nuts were measured: (1) species richness and abun- dance of insects visiting macadamia flowers, (2) the effects of insect pollination in regards to fruit set, fruit retention, fruit size, and weight, and (3) insect pollen removal efficacy based on the mean number of pollen grains an individual insect removed from the stigma while foraging on a macadamia flower. The results from data collected in the study orchard showed that while the order Diptera ranked highest in species richness (9 species), A. mellifera was the most abundant species visiting the macadamia inflorescences (62.7% in abundance, with an average of 17 honeybees seen per 15 minutes compared to 8 flies per 15 minutes). Inflores- cences that were accessible to insects for pollination produced higher fruit sets and yield compared to inflorescences from which insect visitation was excluded. Abundance, foraging behavior and stigma contact, suggested that honeybees are the greatest contributors to macadamia nut pollination over other insects observed in the orchard. The hoverflies (Syrphidae) observed in the orchard may have con- tributed to pollination, but likely to a lesser extent than the honeybees due to the low abundance of the flies
Ecological correlates : endophagous insects and plants in fynbos.
Thesis (Ph.D.)-University of Natal, Pietermaritzburg, 1995.The objective of this study was to investigate endophagous insect species richness in
Fynbos. The influences of plants as determinants of insect occurrence were given special
attention.
The endophagous insects associated with Proteaceae in Fynbos were compared to
endophage assemblages from northern, non-Capensis Proteaceae. The Cape Fynbos
genus Protea is utilized by many more insect taxa than the non-Fynbos species. The high
diversity of host plants in Fynbos appears to have contributed to generating high, local
endophagous insect diversity.
Influences of regional climate, biotope and host-plant characteristics on the frequency
of occurrence of insect borers exploiting Protea species was investigated in Fynbos.
Distinct differences in frequency of encounter of the various insect taxa were recorded
for the various host-plants studied. This variability was primarily accounted for by
physical host-plant characteristics (infructescence and seed-set variables). These findings
have important implications for evolution of insects associated with these plants, as well
as for the conservation of insects and in pest control programmes on indigenous cut
flowers.
The relative species richness of endophagous and ectophagous insects in Fynbos was
compared. Gall-forming insects (Diptera: Cecidomyiidae), were found to be
considerably more speciose than other feeding guilds, showing that the ratio of
endophages to ectophages in sclerophyllous vegetation types is high. The intimate
relationship that endophagous insects have with their host plants tends to habitat
specialization. These insects are therefore likely to undergo radiation together with their
host-plants.
Species richness of gall-insects in Fynbos was investigated to establish whether insect
richness was proportional to plant species richness. The relationship between gall-insect
species richness and plant-species richness was investigated. Fynbos harboured more gall-insect species than other Cape Floristic Region vegetation types. Gall-insect species
richness was positively correlated with plant-species richness. Plant species richness
appears to have contributed to the evolution of a rich gall-insect fauna in the region.
Fynbos gall-insect species richness is comparable to other sclerophyllous vegetation types
globally, underscoring the importance of this vegetation type as a centre of galler
diversification.
Finally, the importance of plant species richness as a determinant of gall-insect species
richness was investigated by comparing different sclerophyllous vegetation types under
the same climatic conditions. Gall were sampled from Fynbos and Karoo vegetation.
Fynbos had higher gall-insect species richness, correlated with plant-species richness.
Plant-species richness, or the distal factors that generated it, appear to have contributed
significantly to the radiation of gall-insects in this region
Comparison of Aircraft Icing Growth Assessment Software
A research project is underway to produce computer software that can accurately predict ice growth under any meteorological conditions for any aircraft surface. An extensive comparison of the results in a quantifiable manner against the database of ice shapes that have been generated in the NASA Glenn Icing Research Tunnel (IRT) has been performed, including additional data taken to extend the database in the Super-cooled Large Drop (SLD) regime. The project shows the differences in ice shape between LEWICE 3.2.2, GlennICE, and experimental data. The project addresses the validation of the software against a recent set of ice-shape data in the SLD regime. This validation effort mirrors a similar effort undertaken for previous validations of LEWICE. Those reports quantified the ice accretion prediction capabilities of the LEWICE software. Several ice geometry features were proposed for comparing ice shapes in a quantitative manner. The resulting analysis showed that LEWICE compared well to the available experimental data
Comparison of LEWICE and GlennICE in the SLD Regime
A research project is underway at the NASA Glenn Research Center (GRC) to produce computer software that can accurately predict ice growth under any meteorological conditions for any aircraft surface. This report will present results from two different computer programs. The first program, LEWICE version 3.2.2, has been reported on previously. The second program is GlennICE version 0.1. An extensive comparison of the results in a quantifiable manner against the database of ice shapes that have been generated in the GRC Icing Research Tunnel (IRT) has also been performed, including additional data taken to extend the database in the Super-cooled Large Drop (SLD) regime. This paper will show the differences in ice shape between LEWICE 3.2.2, GlennICE, and experimental data. This report will also provide a description of both programs. Comparisons are then made to recent additions to the SLD database and selected previous cases. Quantitative comparisons are shown for horn height, horn angle, icing limit, area, and leading edge thickness. The results show that the predicted results for both programs are within the accuracy limits of the experimental data for the majority of cases
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Beagle 2: Seeking the signatures of life on Mars
ESA's Beagle 2 lander will land on Mars to search for signatures of present and past life. A Gas Analysis Package (GAP) with a mass spectrometer, XRF, Mossbauer, stereo cameras, microscope, environmental sensors, rock corer/grinder, and a Mole attachment are on the lander
Discovery of a Classic FR-II Broad Absorption Line Quasar from the FIRST Survey
We have discovered a remarkable quasar, FIRST J101614.3+520916, whose optical
spectrum shows unambiguous broad absorption features while its double-lobed
radio morphology and luminosity clearly indicate a classic Fanaroff-Riley Type
II radio source. Its radio luminosity places it at the extreme of the recently
established class of radio-loud broad absorption line quasars (Becker et al.
1997, 2000; Brotherton et al. 1998). Because of its hybrid nature, we speculate
that FIRST J101614.3+520916 is a typical FR-II quasar which has been
rejuvenated as a broad absorption line (BAL) quasar with a Compact Steep
Spectrum core. The direction of the jet axis of FIRST J101614.3+520916 can be
estimated from its radio structure and optical brightness, indicating that we
are viewing the system at a viewing angle of > 40 degrees. The position angles
of the radio jet and optical polarization are not well-aligned, differing by 20
to 30 degrees. When combined with the evidence presented by Becker et al.
(2000) for a sample of 29 BAL quasars showing that at least some BAL quasars
are viewed along the jet axis, the implication is that no preferred viewing
orientation is necessary to observe BAL systems in a quasar's spectrum. This,
and the probable young nature of compact steep spectrum sources, leads
naturally to the alternate hypothesis that BALs are an early stage in the lives
of quasars.Comment: 14 pages, 6 postscript figures; accepted for publication in the
Astrophysical Journa
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