2,959 research outputs found
Alfalfa Snout Beetle, \u3ci\u3eOtiorhynchus Ligustici\u3c/i\u3e L. (Coleoptera: Curculionidae): Methods for Egg Collection and Larval Rearing
The alfalfa snout beetle, Otiorhynchus ligustici L., is the most serious pest of alfalfa in northern New York State. Recent research efforts focused on the biological control of this insect require the availability of all life stages. With a 2-year lifecycle and a mandatory diapause, the artificial rearing of a laboratory culture appears to be a non-viable option at present, but methods described here can be used to obtain sufficient numbers of eggs and larvae over an extended period of time for research purposes. The crowding of adult beetles in egg production units (cups) had a significant, negative effect on egg production per beetle but the total egg production per cup was still higher with higher number of beetles per cup resulting in a significant saving of labor per egg produced. Larval survival rates in alfalfa-planted cans were surprisingly low given the protected conditions of the greenhouse. The larval survival rates were not significantly different among the dates for the second instar and later instars, suggesting that larval mortality occurs in the first instar in alfalfa-planted cans
GOTCHA Password Hackers!
We introduce GOTCHAs (Generating panOptic Turing Tests to Tell Computers and
Humans Apart) as a way of preventing automated offline dictionary attacks
against user selected passwords. A GOTCHA is a randomized puzzle generation
protocol, which involves interaction between a computer and a human.
Informally, a GOTCHA should satisfy two key properties: (1) The puzzles are
easy for the human to solve. (2) The puzzles are hard for a computer to solve
even if it has the random bits used by the computer to generate the final
puzzle --- unlike a CAPTCHA. Our main theorem demonstrates that GOTCHAs can be
used to mitigate the threat of offline dictionary attacks against passwords by
ensuring that a password cracker must receive constant feedback from a human
being while mounting an attack. Finally, we provide a candidate construction of
GOTCHAs based on Inkblot images. Our construction relies on the usability
assumption that users can recognize the phrases that they originally used to
describe each Inkblot image --- a much weaker usability assumption than
previous password systems based on Inkblots which required users to recall
their phrase exactly. We conduct a user study to evaluate the usability of our
GOTCHA construction. We also generate a GOTCHA challenge where we encourage
artificial intelligence and security researchers to try to crack several
passwords protected with our scheme.Comment: 2013 ACM Workshop on Artificial Intelligence and Security (AISec
Inhibitor regulation of tissue kallikrein activity in the synovial fluid of patients with rheumatoid athritis
Tissue kallikrein (TK) and 1-antitrypsin (AT)/TK complexes can be detected in SF from patients with RA if components of the fluids which interfere with the detection of TK are removed. 2-Macroglobulin (2-M) in SF was demonstrated to contain trapped proteases which were still active in amidase assays. Removal of 2-M from RA SF reduced their amidase activity. However, at least some of the remaining activity was due to TK because it was soya bean trypsin inhibitor resistant and trasylol sensitive and was partly removed by affinity chromatography on anti-TK sepharose. Removal of RF from the fluids reduced the values obtained for TK levels by ELISA. Addition of SF to human urinary kallikrein (HUK) considerably reduced the levels of TK detected suggesting the presence of a TK ELISA inhibitor in the fluids. Removal of components of >300 kDa from SF markedly reduced the TK ELISA inhibitory activity and increased the values for both the TK and l-AT/TK levels in fluids as measured by ELISA. It is considered this novel inhibitor does not bind to the active site of TK but rather binds to the site reactive with anti-TK antibodies
Multi-year Biological Control of Black Vine Weevil, Otiorhynchus sulcatus, with Persistent Entomopathogenic Nematodes
Abstract:
The black vine weevil (BVW), Otiorhynchus sulcatus Fabricius (Coleoptera: Curculionidae), has a worldwide distribution and is a serious pest of many agricultural crops with a host plant species range of 140 plants. Common economic losses occur in small fruits, including strawberries, ornamental and nursery plants, caused primarily by the root feeding larvae resulting in reduced vigor and plant death.
The susceptibility of BVW to entomopathogenic nematodes (EPNs) is well established with numerous authors publishing papers using a wide array of EPN species from commercial sources and very high application rates for use as a biopesticide. The concept of using native EPN strains that are climate adapted and retain the genetic traits of phased infectivity to persist across multiple years was successfully developed and tested on a related species, Otiorhynchus ligustici, alfalfa snout beetle.
In this study, a single application of climate adapted persistent EPN strains resulted in a reduction of an economically damaging BVW population in strawberries to sub-economic levels. Subsequently, the BVW population remained undetectable for four years while the EPN populations remained moderately high
Photometric and Obscurational Completeness
We report a method that uses "completeness" to estimate the number of
exrasolar planets discovered by an observing program with a direct-imaging
instrument. We develop a completeness function for Earth-like planets on
"habitable" orbits for an instrument with a central field obscuration, uniform
sensitivity in an annular detection zone, and limiting sensitivity that is
expressed as a "delta magnitude" with respect to the star, determined by
systematic effects (given adequate exposure time). We demonstrate our method of
estimation by applying it to our understanding of the coronagraphic version of
the Terrestrial Planet Finder (TPF-C) mission as of October 2004. We establish
an initial relationship between the size, quality, and stability of the
instrument's optics and its ability to meet mission science requirements. We
provide options for increasing the fidelity and versatility of the models on
which our method is based, and we discuss how the method could be extended to
model the TPF-C mission as a whole, to verify that its design can meet the
science requirements.Comment: 15 pages, 9 figures, 3 tables. High resolution version of figures may
be viewed at http://sco.stsci.edu/astroph/march05/. ApJ, in pres
Alfalfa Snout Beetle, \u3ci\u3eOtiorhynchus Ligustici\u3c/i\u3e L. (Coleoptera: Curculionidae): Methods for Egg Collection and Larval Rearing
The alfalfa snout beetle, Otiorhynchus ligustici L., is the most serious pest of alfalfa in northern New York State. Recent research efforts focused on the biological control of this insect require the availability of all life stages. With a 2-year lifecycle and a mandatory diapause, the artificial rearing of a laboratory culture appears to be a non-viable option at present, but methods described here can be used to obtain sufficient numbers of eggs and larvae over an extended period of time for research purposes. The crowding of adult beetles in egg production units (cups) had a significant, negative effect on egg production per beetle but the total egg production per cup was still higher with higher number of beetles per cup resulting in a significant saving of labor per egg produced. Larval survival rates in alfalfa-planted cans were surprisingly low given the protected conditions of the greenhouse. The larval survival rates were not significantly different among the dates for the second instar and later instars, suggesting that larval mortality occurs in the first instar in alfalfa-planted cans
HST Imaging of the Globular Clusters in the Fornax Cluster: NGC 1399 and NGC 1404
The Fornax cluster galaxies NGC 1399 and NGC 1404 are ideal for studying the
effects of a cluster environment on globular cluster systems. Here we present
new optical imaging of these two galaxies from both the Hubble Space
Telescope's Wide Field and Planetary Camera 2 and the Cerro Tololo
Inter-American Observatory's 1.5m telescope. The combination of both data sets
provides unique insight on the spatial and colour distribution of globular
clusters. From B-I colours, we find that both galaxies have a broad globular
cluster metallicity distribution that is inconsistent with a single population.
Two Gaussians provide a reasonable representation of the metallicity
distribution in each galaxy. The metal-rich subpopulation is more centrally
concentrated than the metal-poor one. We show that the radial metallicity
gradient can be explained by the changing relative mix of the two globular
cluster subpopulations. We derive globular cluster surface density profiles,
and find that they are flatter (i.e. more extended) than the underlying
starlight. The total number of globular clusters and specific frequency are
calculated to be N = 5700 +/- 500, S_N = 11.5 +/- 1.0 for NGC 1399 and N = 725
+/- 145, S_N = 2.0 +/- 0.5 for NGC 1404. Our results are compared to the
expectations of globular cluster formation scenarios.Comment: 21 pages, Latex, 13 figures, submitted to MNRA
Onset of Phase Synchronization in Neurons Conneted via Chemical Synapses
We study the onset of synchronous states in realistic chaotic neurons coupled
by mutually inhibitory chemical synapses. For the realistic parameters, namely
the synaptic strength and the intrinsic current, this synapse introduces
non-coherences in the neuronal dynamics, yet allowing for chaotic phase
synchronization in a large range of parameters. As we increase the synaptic
strength, the neurons undergo to a periodic state, and no chaotic complete
synchronization is found.Comment: to appear in Int. J. Bif. Chao
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