1,010 research outputs found
Suppression of small baryonic structures due to a primordial magnetic field
We investigate the impact of the existence of a primordial magnetic field on
the filter mass, characterizing the minimum baryonic mass that can form in dark
matter (DM) haloes. For masses below the filter mass, the baryon content of DM
haloes are severely depressed. The filter mass is the mass when the baryon to
DM mass ratio in a halo is equal to half the baryon to DM ratio of the
Universe. The filter mass has previously been used in semianalytic calculations
of galaxy formation, without taking into account the possible existence of a
primordial magnetic field. We examine here its effect on the filter mass. For
homogeneous comoving primordial magnetic fields of or 2 nG and a
reionization epoch that starts at a redshift and is completed at
, the filter mass is increased at redshift 8, for example, by factors
4.1 and 19.8, respectively. The dependence of the filter mass on the parameters
describing the reionization epoch is investigated. Our results are particularly
important for the formation of low mass galaxies in the presence of a
homogeneous primordial magnetic field. For example, for B_0\sim 1\nG and a
reionization epoch of and , our results indicate that
galaxies of total mass M\sim5 \times 10^8\msun need to form at redshifts
, and galaxies of total mass M\sim10^8\msun at redshifts
.Comment: 5 pages, 3 figures, accepted for publication in MNRA
Disentangling superconducting and magnetic orders in NaFe_1-xNi_xAs using muon spin rotation
Muon spin rotation and relaxation studies have been performed on a "111"
family of iron-based superconductors NaFe_1-xNi_xAs. Static magnetic order was
characterized by obtaining the temperature and doping dependences of the local
ordered magnetic moment size and the volume fraction of the magnetically
ordered regions. For x = 0 and 0.4 %, a transition to a nearly-homogeneous long
range magnetically ordered state is observed, while for higher x than 0.4 %
magnetic order becomes more disordered and is completely suppressed for x = 1.5
%. The magnetic volume fraction continuously decreases with increasing x. The
combination of magnetic and superconducting volumes implies that a
spatially-overlapping coexistence of magnetism and superconductivity spans a
large region of the T-x phase diagram for NaFe_1-xNi_xAs . A strong reduction
of both the ordered moment size and the volume fraction is observed below the
superconducting T_C for x = 0.6, 1.0, and 1.3 %, in contrast to other iron
pnictides in which one of these two parameters exhibits a reduction below TC,
but not both. The suppression of magnetic order is further enhanced with
increased Ni doping, leading to a reentrant non-magnetic state below T_C for x
= 1.3 %. The reentrant behavior indicates an interplay between
antiferromagnetism and superconductivity involving competition for the same
electrons. These observations are consistent with the sign-changing s-wave
superconducting state, which is expected to appear on the verge of microscopic
coexistence and phase separation with magnetism. We also present a universal
linear relationship between the local ordered moment size and the
antiferromagnetic ordering temperature TN across a variety of iron-based
superconductors. We argue that this linear relationship is consistent with an
itinerant-electron approach, in which Fermi surface nesting drives
antiferromagnetic ordering.Comment: 20 pages, 14 figures, Correspondence should be addressed to Prof.
Yasutomo Uemura: [email protected]
ULEEN: A Novel Architecture for Ultra Low-Energy Edge Neural Networks
The deployment of AI models on low-power, real-time edge devices requires
accelerators for which energy, latency, and area are all first-order concerns.
There are many approaches to enabling deep neural networks (DNNs) in this
domain, including pruning, quantization, compression, and binary neural
networks (BNNs), but with the emergence of the "extreme edge", there is now a
demand for even more efficient models. In order to meet the constraints of
ultra-low-energy devices, we propose ULEEN, a model architecture based on
weightless neural networks. Weightless neural networks (WNNs) are a class of
neural model which use table lookups, not arithmetic, to perform computation.
The elimination of energy-intensive arithmetic operations makes WNNs
theoretically well suited for edge inference; however, they have historically
suffered from poor accuracy and excessive memory usage. ULEEN incorporates
algorithmic improvements and a novel training strategy inspired by BNNs to make
significant strides in improving accuracy and reducing model size. We compare
FPGA and ASIC implementations of an inference accelerator for ULEEN against
edge-optimized DNN and BNN devices. On a Xilinx Zynq Z-7045 FPGA, we
demonstrate classification on the MNIST dataset at 14.3 million inferences per
second (13 million inferences/Joule) with 0.21 s latency and 96.2%
accuracy, while Xilinx FINN achieves 12.3 million inferences per second (1.69
million inferences/Joule) with 0.31 s latency and 95.83% accuracy. In a
45nm ASIC, we achieve 5.1 million inferences/Joule and 38.5 million
inferences/second at 98.46% accuracy, while a quantized Bit Fusion model
achieves 9230 inferences/Joule and 19,100 inferences/second at 99.35% accuracy.
In our search for ever more efficient edge devices, ULEEN shows that WNNs are
deserving of consideration.Comment: 14 pages, 14 figures Portions of this article draw heavily from
arXiv:2203.01479, most notably sections 5E and 5F.
Effects of Fluoride on Submandibular Glands of Mice: Changes in Oxidative Biochemistry, Proteomic Profile, and Genotoxicity
Although fluoride (F) is well-known to prevent dental caries, changes in cell processes in different tissues have been associated with its excessive exposure. Thus, this study aimed to evaluate the effects of F exposure on biochemical, proteomic, and genotoxic parameters of submandibular glands. Twenty one old rats (n = 30) were allocated into three groups: 60 days administration of drinking water containing 10 mgF/L, 50 mgF/L, or only deionized water (control). The submandibular glands were collected for oxidative biochemistry, protein expression profile, and genotoxic potential analyses. The results showed that both F concentrations increased the levels of thiobarbituric acid–reactive substances (TBARS) and reduced glutathione (GSH) and changed the proteomic profile, mainly regarding the cytoskeleton and cellular activity. Only the exposure to 50 mgF/L induced significant changes in DNA integrity. These findings reinforce the importance of continuous monitoring of F concentration in drinking water and the need for strategies to minimize F intake from other sources to obtain maximum preventive/therapeutic effects and avoid potential adverse effects
Development and Validation of a New BAG-1L–Specific Antibody to Quantify BAG-1L Protein Expression in Advanced Prostate Cancer
Venom alkaloids against Chagas disease parasite: search for effective therapies
Chagas disease is an important disease affecting millions of patients in the New World and is caused by a protozoan transmitted by haematophagous kissing bugs. It can be treated with drugs during the early acute phase; however, effective therapy against the chronic form of Chagas disease has yet to be discovered and developed. We herein tested the activity of solenopsin alkaloids extracted from two species of fire ants against the protozoan parasite Trypanosoma cruzi, the aetiologic agent of Chagas disease. Although IC50 determinations showed that solenopsins are more toxic to the parasite than benznidazole, the drug of choice for Chagas disease treatment, the ant alkaloids presented a lower selectivity index. As a result of exposure to the alkaloids, the parasites became swollen and rounded in shape, with hypertrophied contractile vacuoles and intense cytoplasmic vacuolization, possibly resulting in osmotic stress; no accumulation of multiple kinetoplasts and/or nuclei was detected. Overexpressing phosphatidylinositol 3-kinase—an enzyme essential for osmoregulation that is a known target of solenopsins in mammalian cells—did not prevent swelling and vacuolization, nor did it counteract the toxic effects of alkaloids on the parasites. Additional experimental results suggested that solenopsins induced a type of autophagic and programmed cell death in T. cruzi. Solenopsins also reduced the intracellular proliferation of T. cruzi amastigotes in infected macrophages in a concentration-dependent manner and demonstrated activity against Trypanosoma brucei rhodesiense bloodstream forms, which is another important aetiological kinetoplastid parasite. The results suggest the potential of solenopsins as novel natural drugs against neglected parasitic diseases caused by kinetoplastids.Fil: Silva, Rafael C. M. Costa. Universidade Federal do Rio de Janeiro; BrasilFil: Fox, Eduardo G. P.. Universidade Federal do Rio de Janeiro; Brasil. South China Agricultural University; ChinaFil: Gomes, Fabio M.. Universidade Federal do Rio de Janeiro; Brasil. National Institutes of Health; Estados UnidosFil: Feijó, Daniel F.. Universidade Federal do Rio de Janeiro; BrasilFil: Ramos, Isabela. Universidade Federal do Rio de Janeiro; BrasilFil: Koeller, Carolina M.. Universidade Federal do Rio de Janeiro; Brasil. University at Buffalo; Estados UnidosFil: Costa, Tatiana F. R.. Universidade Federal do Rio de Janeiro; BrasilFil: Rodrigues, Nathalia S.. Universidade Federal do Rio de Janeiro; BrasilFil: Lima, Ana P.. Universidade Federal do Rio de Janeiro; BrasilFil: Atella, Georgia C.. Universidade Federal do Rio de Janeiro; BrasilFil: Rocha de Miranda, Kildare. Universidade Federal do Rio de Janeiro; Brasil. Instituto Nacional de Ciência e Tecnologia em Biologia Estrutural e Bioimagem; BrasilFil: Schoijet, Alejandra Cecilia. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de Investigaciones en IngenierÃa Genética y BiologÃa Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Alonso, Guillermo Daniel. Consejo Nacional de Investigaciones CientÃficas y Técnicas. Instituto de Investigaciones en IngenierÃa Genética y BiologÃa Molecular "Dr. Héctor N. Torres"; ArgentinaFil: de Alcântara Machado, Ednildo. Universidade Federal do Rio de Janeiro; BrasilFil: Heise, Norton. Universidade Federal do Rio de Janeiro; Brasi
Desmotivações no estudo da QuÃmica: Uma análise das causas a partir das percepções de estudantes do ensino médio.
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Uso de árvores nativas em pastagens agroecológicas
O conhecimento tradicional tem sido a base da parceria entre o Centro de Tecnologias Alternativas, as organizações dos agricultores familiares da Zona da Mata de Minas Gerais e as Universidades Federais de Viçosa e, mais recentemente, de Lavras. O objetivo desse trabalho foi identificar o conhecimento tradicional sobre os usos comuns de árvores nativas em pastagens de famÃlias agricultoras dos municÃpios de Divino e Araponga, aplicando metodologias participativas (observação participante e entrevista semi-estruturada). O principal uso da terra na região é com café e pastagens. Foi observado pelas famÃlias que os animais comem ramos de Solanum mauritianum, Senna macranthera, Aegiphila sellowiana e Inga edulis. De acordo com as famÃlias, a maioria das árvores já estava na pastagem antes do capim. É necessário aprofundamento que dialogue com o aprendizado de famÃlias agricultoras.Traditional knowledge has been the main base of the partnership among the Center of Alternative Technologies, the organizations of family farmers of Zona da Mata of Minas Gerais and the Federal Universities of Viçosa and, more recently, of Lavras. The objective was to identify the traditional knowledge about the common uses of native trees in the pastures of the properties of family farmers in the municipalities of Divino and Araponga, applying qualitative methodologies (participant observation and semi-structured interviews).
The land use in the region is mainly coffee and pastures. Was observed by the families that the animals feed themselves with branches of Solanum mauritianum, Senna macranthera, Aegiphila sellowiana and Inga edulis. According to the families the majority of the trees was already in the field before the grass. It is necessary to deep the dialogue to keep leaning and exchange knowledge with smallholders families.Eje A1 Sistemas de producción de base agroecológica (Trabajos cientÃficos)Facultad de Ciencias Agrarias y Forestale
The Origin of Primordial Magnetic Fields
(abridged) We suggest here that the large scale fields G, observed
in galaxies at both high and low redshifts by Faraday Rotation Measurements
(FRMs), have their origin in the electromagnetic fluctuations that naturally
occurred in the dense hot plasma that existed just after the QHPT. We evolve
the predicted fields to the present time. The size of the region containing a
coherent magnetic field increased due to the fusion (polymerization) of smaller
regions. Magnetic fields (MFs) over a comoving pc
region are predicted at redshift z . These fields are orders of
magnitude greater than those predicted in previous scenarios for creating
primordial magnetic fields. Line-of-sight average magnetic fields (MFs)
G, valid for FRMs, are obtained over a 1 Mpc comoving region at
the redshift z 10.
In the collapse to a galaxy (comoving size 30 kpc) at z 10, the
fields are amplified to G. This indicates that the MFs created
immediately after the QHPT, predicted by the Fluctuation-Dissipation Theorem,
could be the origin of the fields observed by FRMs in galaxies at
both high and low redshifts.Comment: 34 pages, 8 figure
The Text Mining Technique Applied to the Analysis of Health Interventions to Combat Congenital Syphilis in Brazil: The Case of the "Syphilis No!" Project
Congenital syphilis (CS) remains a threat to public health worldwide, especially in developing countries. To mitigate the impacts of the CS epidemic, the Brazilian government has developed a national intervention project called "Syphilis No." Thus, among its range of actions is the production of thousands of writings featuring the experiences of research and intervention supporters (RIS) of the project, called field researchers. In addition, this large volume of base data was subjected to analysis through data mining, which may contribute to better strategies for combating syphilis. Natural language processing is a form of knowledge extraction. First, the database extracted from the "LUES Platform" with 4,874 documents between 2018 and 2020 was employed. This was followed by text preprocessing, selecting texts referring to the field researchers' reports for analysis. Finally, for analyzing the documents, N-grams extraction (N = 2,3,4) was performed. The combination of the TF-IDF metric with the BoW algorithm was applied to assess terms' importance and frequency and text clustering. In total, 1019 field activity reports were mined. Word extraction from the text mining method set out the following guiding axioms from the bigrams: "confronting syphilis in primary health care;" "investigation committee for congenital syphilis in the territory;" "municipal plan for monitoring and investigating syphilis cases through health surveillance;" "women's healthcare networks for syphilis in pregnant;" "diagnosis and treatment with a focus on rapid testing." Text mining may serve public health research subjects when used in parallel with the conventional content analysis method. The computational method extracted intervention activities from field researchers, also providing inferences on how the strategies of the "Syphilis No" Project influenced the decrease in congenital syphilis cases in the territory
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