175 research outputs found
Population size estimation for the Warren root collar weevil, Hylobius warreni Wood (Coleoptera: Curculionidae), a pest of regenerating lodgepole pine plantations
The Warren root collar weevil, Hylobius warreni Wood (Coleoptera: Curculionidae), is an endemic pest species of conifers, particularly lodgepole pine (Pinus contorta var. latifolia) (Pinaceae), in British Columbia. Larvae feed on the roots and root collars of young trees, resulting in girdling damage and mortality or growth reductions. Population sizes of adult H. warreni have historically been difficult to assess due to a lack of operational sampling methods or chemical attractants for the species. Therefore, most previous population estimates have relied on indirect or incomplete measures of damage by immature individuals. In this study, we tested the Björklund funnel trap to assess its efficacy as a method to estimate H. warreni populations. Funnel traps were placed on all 182 trees in half of a small (~1 ha) lodgepole pine stand over four days and remained in place for 13 days after the last traps were installed. Adult weevils were captured, marked, and released on the bole of the tree on which they had been caught. It is likely that most of the adult weevils in the plot, which was isolated from any nearby lodgepole pine stands, were caught at least once and many were caught multiple times. Population sizes were estimated using both the Schnabel method and the Schumacher and Eschmeyer method, resulting in population estimates of 1.83-2.19 weevils/tree and 731-875 weevils/ha. These measures are within the range of population sizes estimated by previous studies. The results suggest the Björklund funnel trap may be an effective operational tool for population monitoring for this species and may also be an effective tactic in population reduction strategies
Wigner State and Process Tomography on Near-Term Quantum Devices
We present an experimental scanning-based tomography approach for near-term
quantum devices. The underlying method has previously been introduced in an
ensemble-based NMR setting. Here we provide a tutorial-style explanation along
with suitable software tools to guide experimentalists in its adaptation to
near-term pure-state quantum devices. The approach is based on a Wigner-type
representation of quantum states and operators. These representations provide a
rich visualization of quantum operators using shapes assembled from a linear
combination of spherical harmonics. These shapes (called droplets in the
following) can be experimentally tomographed by measuring the expectation
values of rotated axial tensor operators. We present an experimental framework
for implementing the scanning-based tomography technique for circuit-based
quantum computers and showcase results from IBM quantum experience. We also
present a method for estimating the density and process matrices from
experimentally tomographed Wigner functions (droplets). This tomography
approach can be directly implemented using the Python-based software package
\texttt{DROPStomo}.Comment: Extended supplemental section on temporal averagin
MorDIFF: Recognition Vulnerability and Attack Detectability of Face Morphing Attacks Created by Diffusion Autoencoders
Investigating new methods of creating face morphing attacks is essential to
foresee novel attacks and help mitigate them. Creating morphing attacks is
commonly either performed on the image-level or on the representation-level.
The representation-level morphing has been performed so far based on generative
adversarial networks (GAN) where the encoded images are interpolated in the
latent space to produce a morphed image based on the interpolated vector. Such
a process was constrained by the limited reconstruction fidelity of GAN
architectures. Recent advances in the diffusion autoencoder models have
overcome the GAN limitations, leading to high reconstruction fidelity. This
theoretically makes them a perfect candidate to perform representation-level
face morphing. This work investigates using diffusion autoencoders to create
face morphing attacks by comparing them to a wide range of image-level and
representation-level morphs. Our vulnerability analyses on four
state-of-the-art face recognition models have shown that such models are highly
vulnerable to the created attacks, the MorDIFF, especially when compared to
existing representation-level morphs. Detailed detectability analyses are also
performed on the MorDIFF, showing that they are as challenging to detect as
other morphing attacks created on the image- or representation-level. Data and
morphing script are made public: https://github.com/naserdamer/MorDIFF.Comment: Accepted at the 11th International Workshop on Biometrics and
Forensics 2023 (IWBF 2023
Differential localization of flavonoid glucosides in an aquatic plant implicates different functions under abiotic stress
Abstract Flavonoids may mediate UV protection in plants either by screening of harmful radiation or by minimizing the resulting oxidative stress. To help distinguish between these alternatives, more precise knowledge of flavonoid distribution is needed. We used confocal laser scanning microscopy (cLSM) with the “emission fingerprinting” feature to study the cellular and subcellular distribution of flavonoid glucosides in the giant duckweed ( Spirodela polyrhiza ), and investigated the fitness effects of these compounds under natural UV radiation and copper sulphate addition (oxidative stress) using common garden experiments indoors and outdoors. cLSM “emission fingerprinting” allowed us to individually visualize the major dihydroxylated B‐ring‐substituted flavonoids, luteolin 7‐O‐glucoside and luteolin 8‐C‐glucoside, in cross‐sections of the photosynthetic organs. While luteolin 8‐C‐glucoside accumulated mostly in the vacuoles and chloroplasts of mesophyll cells, luteolin 7‐O‐glucoside was predominantly found in the vacuoles of epidermal cells. In congruence with its cellular distribution, the mesophyll‐associated luteolin 8‐C‐glucoside increased plant fitness under copper sulphate addition but not under natural UV light treatment, whereas the epidermis‐associated luteolin 7‐O‐glucoside tended to increase fitness under both stresses across chemically diverse genotypes. Taken together, we demonstrate that individual flavonoid glucosides have distinct cellular and subcellular locations and promote duckweed fitness under different abiotic stresses
Reduction of conceptual model uncertainty using ground-penetrating radar profiles: Field-demonstration for a braided-river aquifer
Hydrogeological flow and transport strongly depend on the connectivity of
subsurface properties. Uncertainty concerning the underlying geological
setting, due to a lack of field data and prior knowledge, calls for an
evaluation of alternative geological conceptual models. To reduce the
computational costs associated with inversions (parameter estimation for a
given conceptual model), it is beneficial to rank and discard unlikely
conceptual models prior to inversion. Here, we demonstrate an approach based on
a quantitative comparison of ground-penetrating radar (GPR) sections obtained
from field data with corresponding simulation results arising from various
geological scenarios. The comparison is based on three global distance measures
related to wavelet decomposition, multiple-point histograms, and connectivity
that capture geometrical characteristics of geophysical reflection images.
Using field data from the Tagliamento braided river system, Italy, we
demonstrate that seven out of nine considered geological scenarios can be
discarded as they produce GPR sections that are incompatible with those
observed in the field. The retained scenarios reproduce important features such
as cross-stratified deposits and irregular property interfaces. The most
convenient distance measure of those considered is the one based on
wavelet-decomposition. Direct analysis of the distances is the most intuitive
and fastest way to compare scenarios
A Comprehensive Study on Face Recognition Biases Beyond Demographics
Face recognition (FR) systems have a growing effect on critical
decision-making processes. Recent works have shown that FR solutions show
strong performance differences based on the user's demographics. However, to
enable a trustworthy FR technology, it is essential to know the influence of an
extended range of facial attributes on FR beyond demographics. Therefore, in
this work, we analyse FR bias over a wide range of attributes. We investigate
the influence of 47 attributes on the verification performance of two popular
FR models. The experiments were performed on the publicly available MAADFace
attribute database with over 120M high-quality attribute annotations. To
prevent misleading statements about biased performances, we introduced control
group based validity values to decide if unbalanced test data causes the
performance differences. The results demonstrate that also many non-demographic
attributes strongly affect the recognition performance, such as accessories,
hair-styles and colors, face shapes, or facial anomalies. The observations of
this work show the strong need for further advances in making FR system more
robust, explainable, and fair. Moreover, our findings might help to a better
understanding of how FR networks work, to enhance the robustness of these
networks, and to develop more generalized bias-mitigating face recognition
solutions.Comment: Under review in IEEE Transactions on Technology and Societ
Super-resolution lightwave tomography of electronic bands in quantum materials
Searching for quantum functionalities requires access to the electronic structure, constituting the foundation of exquisite spin-valley-electronic, topological, and many-body effects. All-optical band-structure reconstruction could directly connect electronic structure with the coveted quantum phenomena if strong lightwaves transported localized electrons within preselected bands. Here, we demonstrate that harmonic sideband (HSB) generation in monolayer tungsten diselenide creates distinct electronic interference combs in momentum space. Locating these momentum combs in spectroscopy enables super-resolution tomography of key band-structure details in situ. We experimentally tuned the optical-driver frequency by a full octave and show that the predicted super-resolution manifests in a critical intensity and frequency dependence of HSBs. Our concept offers a practical, all-optical, fully three-dimensional tomography of electronic structure even in microscopically small quantum materials, band by band
The WCET Tool Challenge 2011
Following the successful WCET Tool Challenges in 2006 and 2008, the third event in this series was organized in 2011, again with support from the ARTIST DESIGN Network of Excellence. Following the practice established in the previous Challenges, the WCET Tool Challenge 2011 (WCC'11) defined two kinds of problems to be solved by the Challenge participants with their tools, WCET problems, which ask for bounds on the execution time, and flow-analysis problems, which ask for bounds on the number of times certain parts of the code can be executed. The benchmarks to be used in WCC'11 were debie1, PapaBench, and an industrial-strength application from the automotive domain provided by Daimler AG. Two default execution platforms were suggested to the participants, the ARM7 as "simple target'' and the MPC5553/5554 as a "complex target,'' but participants were free to use other platforms as well. Ten tools participated in WCC'11: aiT, Astr\'ee, Bound-T, FORTAS, METAMOC, OTAWA, SWEET, TimeWeaver, TuBound and WCA
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