1,915 research outputs found
Braess's Paradox in Wireless Networks: The Danger of Improved Technology
When comparing new wireless technologies, it is common to consider the effect
that they have on the capacity of the network (defined as the maximum number of
simultaneously satisfiable links). For example, it has been shown that giving
receivers the ability to do interference cancellation, or allowing transmitters
to use power control, never decreases the capacity and can in certain cases
increase it by , where is the
ratio of the longest link length to the smallest transmitter-receiver distance
and is the maximum transmission power. But there is no reason to
expect the optimal capacity to be realized in practice, particularly since
maximizing the capacity is known to be NP-hard. In reality, we would expect
links to behave as self-interested agents, and thus when introducing a new
technology it makes more sense to compare the values reached at game-theoretic
equilibria than the optimum values.
In this paper we initiate this line of work by comparing various notions of
equilibria (particularly Nash equilibria and no-regret behavior) when using a
supposedly "better" technology. We show a version of Braess's Paradox for all
of them: in certain networks, upgrading technology can actually make the
equilibria \emph{worse}, despite an increase in the capacity. We construct
instances where this decrease is a constant factor for power control,
interference cancellation, and improvements in the SINR threshold (),
and is when power control is combined with interference
cancellation. However, we show that these examples are basically tight: the
decrease is at most O(1) for power control, interference cancellation, and
improved , and is at most when power control is
combined with interference cancellation
A Step Forward in Breast Cancer Research: Gold Nanoparticles as Photothermal Therapy Enhancers
Gold nanoparticles (AuNPs) have been widely used and characterized for multiple biomedical applications, including the enhancement of photothermal therapy (PTT). AuNPs present a particular plasmon resonance band and are able to convert the absorbed optical radiation into heat, which validates their use in PTT. Several production methods have already been proposed for the synthesis of AuNPs, allowing to optimize the particles' morphology, size and optical properties. However, the production methods commonly used are frequently associated with the use of toxic reagents such as Cetyltrimethylammonium bromide, which presents some concerns for clinical applications. Herein, it is proposed a novel AuNPs' core synthesis method using tetrachloroauric acid and a mixture of reducing agents, later on coated with a combination of hyaluronic and oleic acids. The coating here represents a potential improvement of AuNPs biocompatibility, biodegradability and lifetime, while simultaneously potentiating the attachment towards specific ligands, such as the CD44 receptor, to develop more localized and highly selective tools. The produced functionalized nanoparticles were characterized by Dynamic Light Scattering, Microscopy Techniques and Spectroscopy, showing diameter sizes under 350 nm, polydispersity index smaller than 0.4 and enhanced absorbance in the Near Infrared (NIR, 650 to 900 nm) range. Moreover, the AuNPs safety and efficacy were preliminarily assessed in vitro using breast cancer cell lines. No toxicity was observed by MTT assay, both in breast cancer cell lines, and red blood cells. The irradiation process was proved to be safe; however, when combined with the AuNPs administration, it resulted in a significant reduction of cell viability for some of the breast cell lines tested. Thus, the results highlight the potential of the proposed system for some type of tumors, even though further tests are required to better understand the mechanisms behind the obtained results
Orari di lavoro e sonno nel personale infermieristico impiegato in sistemi di turnazione rapida "23x8" e "2x12"
Obiettivo dello studio \ue8 di verificare, in un
campione di 200 infermieri turnisti, l\u2019impatto sul sonno della diversa tipologia di lavoro (\u201cemergenza/urgenza\u201d vs.
\u201cdegenza\u201d) nell\u2019ambito dello stesso schema di turno, e di due diversi schemi di turnazione a rotazione rapida (\u201c2x12\u201d
e \u201c3x8\u201d), nell\u2019ambito della stessa area di lavoro (\u201cemergenza/urgenza\u201d). Il turno notturno e quello del mattino risultano interferire maggiormente con il sonno, sia in
relazione ai due tipi di turno che alle due aree operative considerate. Emerge l\u2019importanza di considerare, nella
strutturazione dello schema dei turni, le modalit\ue0 di rotazione tra i turni e il carico di lavoro in relazione alla durata del
turno stesso
Immuno-Transcriptomic Profiling of Blood and Tumor Tissue Identifies Gene Signatures Associated with Immunotherapy Response in Metastatic Bladder Cancer.
Blood-based biomarkers represent ideal candidates for the development of non-invasive immuno-oncology-based assays. However, to date, no blood biomarker has been validated to predict clinical responses to immunotherapy. In this study, we used next-generation sequencing (RNAseq) on bulk RNA extracted from whole blood and tumor samples in a pre-clinical MIBC mouse model. We aimed to identify biomarkers associated with immunotherapy response and assess the potential application of simple non-invasive blood biomarkers as a therapeutic decision-making assay compared to tissue-based biomarkers. We established that circulating immune cells and the tumor microenvironment (TME) display highly organ-specific transcriptional responses to ICIs. Interestingly, in both, a common lymphocytic activation signature can be identified associated with the efficient response to immunotherapy, including a blood-specific CD8+ T cell activation/proliferation signature which predicts the immunotherapy response
Phylogenetic and pathotype analysis of Escherichia coli swine isolates from Southern Brazil
Hadean geodynamics inferred from time-varying 142Nd/144Nd in the early Earth rock record
Tracking the secular evolution of 142Nd/144Nd anomalies is important towards
understanding the crust-mantle dynamics in the early Earth. Excessive scatter in
the published data, however, precludes identifying the fine structure of
142Nd/144Nd evolution as the expected variability is on the order of few parts per
million. We report ultra-high precision 142Nd/144Nd data for Eoarchean and
Palaeoarchean rocks from the Isua Supracrustal Belt (SW Greenland) that show
a well-resolved 142Nd/144Nd temporal variability suggesting progressive convective
homogenisation of the Hadean Isua depleted mantle. This temporally
decreasing 142Nd/144Nd signal provides a direct measure of early mantle dynamics,
defining a stirring timescale of <250 Myr consistent with vigorous convective
stirring in the early mantle. The 142Nd/144Nd evolution suggests protracted crustal
residence times of ~1000-2000 Myr, inconsistent with modern-style plate tectonics
in the Archean. In contrast, a stagnant-lid regime punctuated by episodes of mantle overturns accounts for the long life-time
estimated here for the Hadean proto-crust
Protection from Staphylococcus aureus mastitis associated with poly-N-acetyl beta-1,6 glucosamine specific antibody production using biofilm-embedded bacteria
Staphylococcus aureus vaccines based on bacterins surrounded by slime, surface polysaccharides
coupled to protein carriers and polysaccharides embedded in liposomes administered together with
non-biofilm bacterins confer protection against mastitis. However, it remains unknown whether
protective antibodies are directed to slime-associated known exopolysaccharides and could be
produced in the absence of bacterin immunizations. Here, a sheep mastitis vaccination study was
carried out using bacterins, crude bacterial extracts or a purified exopolysaccharide from biofil
Prediction of fatty acid composition in intact and minced fat of European autochthonous pigs breeds by near infrared spectroscopy
The fatty acids profile has been playing a decisive role in recent years, thanks to technological, sensory and health demands from producers and consumers. The application of NIRS technique on fat tissues, could lead to more efficient, practical, and economical in the quality control. The study aim was to assess the accuracy of Fourier Transformed Near Infrared Spectroscopy technique to determine fatty acids composition in fat of 12 European local pig breeds. A total of 439 spectra of backfat were collected both in intact and minced tissue and then were analyzed using gas chromatographic analysis. Predictive equations were developed using the 80% of samples for the calibration, followed by full cross validation, and the remaining 20% for the external validation test. NIRS analysis of minced samples allowed a better response for fatty acid families, n6 PUFA, it is promising both for n3 PUFA quantification and for the screening (high, low value) of the major fatty acids. Intact fat prediction, although with a lower predictive ability, seems suitable for PUFA and n6 PUFA while for other families allows only a discrimination between high and low values.IRTA acknowledge the Consolidated Research Group (2021 SGR 00461) and CERCA Program to partially support this work
A first-principles approach to electrical transport in atomic-scale nanostructures
We present a first-principles numerical implementation of Landauer formalism
for electrical transport in nanostructures characterized down to the atomic
level. The novelty and interest of our method lies essentially on two facts.
First of all, it makes use of the versatile Gaussian98 code, which is widely
used within the quantum chemistry community. Secondly, it incorporates the
semi-infinite electrodes in a very generic and efficient way by means of Bethe
lattices. We name this method the Gaussian Embedded Cluster Method (GECM). In
order to make contact with other proposed implementations, we illustrate our
technique by calculating the conductance in some well-studied systems such as
metallic (Al and Au) nanocontacts and C-atom chains connected to metallic (Al
and Au) electrodes. In the case of Al nanocontacts the conductance turns out to
be quite dependent on the detailed atomic arrangement. On the contrary, the
conductance in Au nanocontacts presents quite universal features. In the case
of C chains, where the self-consistency guarantees the local charge transfer
and the correct alignment of the molecular and electrode levels, we find that
the conductance oscillates with the number of atoms in the chain regardless of
the type of electrode. However, for short chains and Al electrodes the even-odd
periodicity is reversed at equilibrium bond distances.Comment: 14 pages, two-column format, submitted to PR
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