2,049 research outputs found
Comparing bird and human soaring strategies
Gliding saves much energy, and to make large distances using only this form
of flight represents a great challenge for both birds and people. The solution
is to make use of the so-called thermals, which are localized, warmer regions
in the atmosphere moving upwards with a speed exceeding the descent rate of
bird and plane. Whereas birds use this technique mainly for foraging, humans do
it as a sporting activity. Thermalling involves efficient optimization
including the skilful localization of thermals, trying to guess the most
favorable route, estimating the best descending rate, etc. In this study, we
address the question whether there are any analogies between the solutions
birds and humans find to handle the above task. High-resolution track logs were
taken from thermalling falcons and paraglider pilots to determine the essential
parameters of the flight patterns. We find that there are relevant common
features in the ways birds and humans use thermals. In particular, falcons seem
to reproduce the MacCready formula widely used by gliders to calculate the best
slope to take before an upcoming thermal.Comment: 8 pages, 4 figures. Supplementary materials are available at the
webpage dedicated to this work: http://angel.elte.hu/thermalling
A Happy Face Advantage With Male Caucasian Faces: It Depends on the Company You Keep
Happy faces are categorized faster as “happy” than angry faces as “angry,” the happy face advantage. Here, we show across three experiments that the size of the happy face advantage for male Caucasian faces varies as a function of the other faces they are presented with. A happy face advantage was present if the male Caucasian faces were presented among male African American faces, but absent if the same faces were presented among female faces, Caucasian or African American. The modulation of the happy face advantage for male Caucasian faces was observed even if the female Caucasian/male African American faces had neutral expressions. This difference in the happy face advantage for a constant set of faces as a function of the other faces presented indicates that it does not reflect on a stimulus-dependent bottom-up process but on the evaluation of the expressive faces within a specific context
Detection of triplex PCR for the modified qualitative soybean and maize genetically
A molecular screening method based on multiplex PCR that involves amplification of specific soybean or maize sequences from plant DNA (lectin or zein) and the amplification of 35S promoter and NOS terminator,for the detection of genetically modified soybean and maize was developed. The new method is proposed,for the simulicmeous cletcctimt of tree genetic elements in the.same run as reliable method for rapid detection of genetically, modified plants with sensitivity of 0.1%
Evaluation of the utility of interphase cytogenetics to detect residual cells with a malignant genotype in mixed cell populations: a Burkitt lymphoma model
TrustShadow: Secure Execution of Unmodified Applications with ARM TrustZone
The rapid evolution of Internet-of-Things (IoT) technologies has led to an
emerging need to make it smarter. A variety of applications now run
simultaneously on an ARM-based processor. For example, devices on the edge of
the Internet are provided with higher horsepower to be entrusted with storing,
processing and analyzing data collected from IoT devices. This significantly
improves efficiency and reduces the amount of data that needs to be transported
to the cloud for data processing, analysis and storage. However, commodity OSes
are prone to compromise. Once they are exploited, attackers can access the data
on these devices. Since the data stored and processed on the devices can be
sensitive, left untackled, this is particularly disconcerting.
In this paper, we propose a new system, TrustShadow that shields legacy
applications from untrusted OSes. TrustShadow takes advantage of ARM TrustZone
technology and partitions resources into the secure and normal worlds. In the
secure world, TrustShadow constructs a trusted execution environment for
security-critical applications. This trusted environment is maintained by a
lightweight runtime system that coordinates the communication between
applications and the ordinary OS running in the normal world. The runtime
system does not provide system services itself. Rather, it forwards requests
for system services to the ordinary OS, and verifies the correctness of the
responses. To demonstrate the efficiency of this design, we prototyped
TrustShadow on a real chip board with ARM TrustZone support, and evaluated its
performance using both microbenchmarks and real-world applications. We showed
TrustShadow introduces only negligible overhead to real-world applications.Comment: MobiSys 201
FeynGame
A java-based graphical tool for drawing Feynman diagrams is presented. It
differs from similar existing tools in various respects. For example, it is
based on models, consisting of particles (lines) and (optionally) vertices,
each of which can be given their individual properties (line style, color,
arrows, label, etc.). The diagrams can be exported in any standard image
format, or as PDF. Aside from its plain graphical aspect, the goal of FeynGame
is also educative, as it can check a Feynman diagrams validity. This provides
the basis to play games with diagrams, for example. Here we describe on such
game where a given set of initial and final states must be connected through a
Feynman diagram within a given interaction model.Comment: 26 pages, several figures and screenshots. FeynGame is available from
https://gitlab.com/feyngame/FeynGam
Comment on ``Reduction of static field equation of Faddeev model to first order PDE'', arXiv:0707.2207
The authors of the article Phys. Lett. B 652 (2007) 384, (arXiv:0707.2207),
propose an interesting method to solve the Faddeev model by reducing it to a
set of first order PDEs. They first construct a vectorial quantity , depending on the original field and its first derivatives, in terms of which
the field equations reduce to a linear first order equation. Then they find
vectors and which identically obey this linear
first order equation. The last step consists in the identification of the with the original as a function of the original field.
Unfortunately, the derivation of this last step in the paper cited above
contains an error which invalidates most of its results
CCR7 is required for the in vivo function of CD4+ CD25+ regulatory T cells
CCR7-mediated migration of naive T cells into the secondary lymphoid organs is a prerequisite for their encounter with mature dendritic cells, the productive presentation of cognate antigen, and consequent T cell proliferation and effector differentiation. Therefore, CCR7 was suggested to play an important role in the initiation of adaptive immune responses. In this study, we show that primary immunity can also develop in the absence of CCR7. Moreover, CCR7-deficient knockout (KO) mice display augmented immune responses. Our data cumulatively suggest that enhanced immunity in CCR7 KO mice is caused by the defective lymph node (LN) positioning of FoxP3(+) CD4(+) CD25(+) regulatory T cells (T reg cells) and the consequent impediment of their function. The FoxP3(+) T reg cells express CCR7 and, after their adoptive transfer, migrate into the LNs of wild-type mice. Here, they proliferate in situ upon antigen stimulation and inhibit the generation of antigen-specific T cells. Conversely, transferred CCR7-deficient T reg cells fail to migrate into the LNs and suppress antigen-induced T cell responses. The transfer of combinations of naive and T reg cells from wild-type and CCR7 KO mice into syngeneic severe combined immunodeficient mice directly demonstrates that CCR7-deficient T reg cells are less effective than their wild-type counterparts in preventing the development of inflammatory bowel diseas
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