Cosmic rays are energetic charged particles from extraterrestrial sources, with the highest-energy events thought to come from extragalactic sources. Their arrival is infrequent, so detection ...requires instruments with large collecting areas. In this work, we report the detection of an extremely energetic particle recorded by the surface detector array of the Telescope Array experiment. We calculate the particle’s energy as
244
±
29
stat
.
−
76
+
51
syst
.
exa–electron volts
(~40 joules). Its arrival direction points back to a void in the large-scale structure of the Universe. Possible explanations include a large deflection by the foreground magnetic field, an unidentified source in the local extragalactic neighborhood, or an incomplete knowledge of particle physics.
Editor’s summary
Cosmic rays are charged particles from space. At low energies, they mostly originate from the Sun, whereas at high energies, they are expected to be emitted by nearby active galaxies. The Telescope Array Collaboration now reports the detection of a cosmic ray event with an energy of about 240 exa–electron volts, more than a million times higher than that achieved by artificial particle accelerators. Such high-energy particles should experience only small deflections by foreground magnetic fields, but tracing back the arrival direction shows no obvious source galaxy. The authors suggest that the foreground magnetic fields might be stronger than expected, or there could be unknown particle physics at high energies. —Keith T. Smith
Detection of a highly energetic cosmic ray is traced back to its arrival direction, but no source galaxy is evident.
Photonuclear reactions of light nuclei below a mass of
A
=
60
are planned to be studied experimentally and theoretically with the PANDORA (Photo-Absorption of Nuclei and Decay Observation for ...Reactions in Astrophysics) project. Two experimental methods, virtual photon excitation by proton scattering and real photo absorption by a high-brilliance
γ
-ray beam produced by laser Compton scattering, will be applied to measure the photoabsorption cross sections and decay branching ratio of each decay channel as a function of the photon energy. Several nuclear models, e.g. anti-symmetrized molecular dynamics, mean-field and beyond-mean-field models, a large-scale shell model, and ab initio models, will be employed to predict the photonuclear reactions. The uncertainty in the model predictions will be evaluated based on the discrepancies between the model predictions and experimental data. The data and predictions will be implemented in the general reaction calculation code, TALYS. The results will be applied to the simulation of the photo-disintegration process of ultra-high-energy cosmic rays in inter-galactic propagation.
Sugarcane (Saccharum spp.) is a clonally propagated outcrossing polyploid crop of great importance in tropical agriculture. Up to now, all sugarcane genetic maps had been developed using either ...full-sib progenies derived from interspecific crosses or from selfing, both approaches not directly adopted in conventional breeding. We have developed a single integrated genetic map using a population derived from a cross between two pre-commercial cultivars ('SP80-180' x 'SP80-4966') using a novel approach based on the simultaneous maximum-likelihood estimation of linkage and linkage phases method specially designed for outcrossing species. From a total of 1,118 single-dose markers (RFLP, SSR and AFLP) identified, 39% derived from a testcross configuration between the parents segregating in a 1:1 fashion, while 61% segregated 3:1, representing heterozygous markers in both parents with the same genotypes. The markers segregating 3:1 were used to establish linkage between the testcross markers. The final map comprised of 357 linked markers, including 57 RFLPs, 64 SSRs and 236 AFLPs that were assigned to 131 co-segregation groups, considering a LOD score of 5, and a recombination fraction of 37.5 cM with map distances estimated by Kosambi function. The co-segregation groups represented a total map length of 2,602.4 cM, with a marker density of 7.3 cM. When the same data were analyzed using JoinMap software, only 217 linked markers were assigned to 98 co-segregation groups, spanning 1,340 cM, with a marker density of 6.2 cM. The maximum-likelihood approach reduced the number of unlinked markers to 761 (68.0%), compared to 901 (80.5%) using JoinMap. All the co-segregation groups obtained using JoinMap were present in the map constructed based on the maximum-likelihood method. Differences on the marker order within the co-segregation groups were observed between the two maps. Based on RFLP and SSR markers, 42 of the 131 co-segregation groups were assembled into 12 putative homology groups. Overall, the simultaneous maximum-likelihood estimation of linkage and linkage phases was more efficient than the method used by JoinMap to generate an integrated genetic map of sugarcane.
The Brazilian National Biosafety Committee approved in 2011 a new post release monitoring system for environmental releases of genetically modified organisms. It has a number of novel features in ...comparison with other established or proposed systems. The new system also allows the proponent to ask for monitoring exemption. General surveillance forms the basis of the monitoring system, similar to the European model, but differs markedly in the way it operates. While the European proposal is based on monitoring measurable variables extracted from environmental observations, from baselines previously established for multiple protection targets, the Brazilian system uses direct alerts of damage, without the aid of baseline values. The strength of the Brazilian form of monitoring is the possibility of generating an information network with the effective participation of many actors from the monitored area. A network constituted by highly qualified members, as proposed elsewhere, is too complex and unrealistic in Brazil and in many other countries. In conclusion, the Brazilian monitoring system is flexible and can be adjusted to the Brazilian reality over the next years, as a response to the ever growing experience in monitoring. It also meets the demands of the Brazilian society for transparency, rational use of resources, opportunity for national companies, and food and environmental biosafety.
Defensin, thionin and lipid transfer protein (LTP) gene families, which antimicrobial activity has an attractive use in protein engineering and transgenic production of agronomical important plants, ...have been here functionally reviewed. Also, a transcriptional overview of a set of plant SuperSAGE libraries and analysis looking for 26 bp tags possibly annotated for those families is presented. Tags differentially expressed (p = 0.05) or constitutively transcribed were identified from leaves or roots SuperSAGE libraries from important Brazilian plant species cowpea (Vigna unguiculata (L.) Walp.), soybean (Glycine max (L.) Merr.) and modern sugarcane hybrids (Saccharum spp.) submitted to abiotic salt (100 mM NaCl) or drought or biotic stresses fungus inoculation (Phakopsora pachyrhizi; Asiatic Soyben Rust phytopathogen). The diverse transcriptional patterns observed, probably related to the variable range of targets and functions involved, could be the first step to unravel the antimicrobial peptide world and the plant stress response relationship. Moreover, SuperSAGE opens the opportunity to find some SNPs or even rare transcript that could be important on plant stress resistance mechanisms. Putative defensin or LTP identified by SuperSAGE following a specific plant treatment or physiological condition could be useful for future use in genetic improvement of plants.
As anemias diseritropoiéticas congênitas (ADC) são um grupo heterogêneo e raro de anemias hereditárias caracterizadas por diseritropoiese, eritropoiese ineficaz e achados morfológicos típicos. Com ...base nas características morfológicas, as ADCs são classificadas em tipos I, II, III e IV, porém há casos de pacientes que não se enquadram em um grupo específico. A variedade de fenótipos observados dificulta o diagnóstico e manejo clínico, com escassez de dados na literatura. Relatamos o caso de ADC com morfologia tipo II com padrão de herança atípico (autossômico dominante).
Revisão retrospectiva do prontuário médico.
Feminino, 26 anos, branca, apresentando anemia crônica e sinais de hemólise: Hb 8,1 g/dL, VCM 93 fL, RDW 28%, hematoscopia com poiquilocitose, esquizócitos e policromasia, bilirrubina indireta de 2,46 mg/dL, Coombs direto negativo e reticulócitos 87.000/mm3. Exame físico: icterícia discreta, olhos azuis amendoados, distância interorbitária limítrofe 3 cm, baço palpável 6 cm do rebordo costal, hipoplasia das falanges distais dos pés e das mãos e sindactilia. US de abdome: esplenomegalia homogênea e colecistopatia calculosa. Mielograma: acentuada diseritropoiese, com 17% de eritroblastos binucleados, 1% de eritroblastos trinucleados, 5% de eritroblastos com pontes internucleares e 4% de eritroblastos com sinais de cariorrexis, achados compatíveis com ADC tipo II. Submetida a colecistectomia devido colelitíase sintomática e esplenectomia no mesmo tempo cirúrgico, sem aumento significativo da hemoglobina. Atualmente com 35 anos de idade, mantém-se com anemia moderada assintomática, níveis de Hb em torno de 10,5 g/dL, sem necessidade transfusional. Faz uso diário de ácido fólico 5mg. Histórico familiar: Possui uma filha com fenótipo normal e sem anemia. Sua mãe e seu único irmão apresentavam alterações laboratoriais semelhantes e as mesmas malformações em extremidades; ainda, a mãe apresentava hipertelorismo ocular e colecistopatia calculosa. Pai sem alteração do hemograma ou malformações congênitas. Não havia relato de familiares de segundo grau com doença hematológica ou malformações congênitas; seus avós maternos tiveram 11 filhos e somente a mãe da paciente apresentou o fenótipo.
ADCs são consequências de um desarranjo no processo de maturação eritroide e devem ser lembradas na presença de anemia crônica com sinais de hemólise e contagem de reticulócitos inadequadamente baixa para o grau de anemia. Trata-se na maioria dos casos de uma doença autossômica recessiva, sendo a ADC tipo II a mais frequente; os tipos III e IV apresentam padrão autossômico dominante e são formas mais raras. A avaliação genética é recomendada em todos os casos, porém, em locais sem acesso a tais exames, a análise das características morfológicas dos eritroblastos na medula óssea ainda é o meio mais utilizado.
Descrevemos o caso de uma mulher jovem com anemia hemolítica crônica e alterações fenotípicas, com morfologia medular compatível com ADC tipo II, porém padrão de herança autossômico dominante, típico de ADC III e IV. Sequenciamento genético seria útil neste caso a fim de identificar a presença de genes que apresentam relação com os diferentes tipos de ACD ou de permitir a descoberta de novos genes associados a formas atípicas da doença.
We have searched for intermediate-scale anisotropy in the arrival directions of ultrahigh-energy cosmic rays with energies above 57 EeV in the northern sky using data collected over a 5 yr period by ...the surface detector of the Telescope Array experiment. We report on a cluster of events that we call the hotspot, found by oversampling using 20degrees radius circles. The hotspot has a Li-Ma statistical significance of 5.1sigma, and is centered at R.A. = 146degrees.7, decl. = 43degrees.2. The position of the hotspot is about 19degrees off of the supergalactic plane. The probability of a cluster of events of 5.1sigma significance, appearing by chance in an isotropic cosmic-ray sky, is estimated to be 3.7 x 10 super(-4) (3.4sigma).
We report on a measurement of the cosmic ray energy spectrum by the Telescope Array Low-Energy Extension (TALE) air fluorescence detector (FD). The TALE air FD is also sensitive to the Cherenkov ...light produced by shower particles. Low-energy cosmic rays, in the PeV energy range, are detectable by TALE as Cherenkov events. Using these events, we measure the energy spectrum from a low energy of ∼2 PeV to an energy greater than 100 PeV. Above 100 PeV, TALE can detect cosmic rays using air fluorescence. This allows for the extension of the measurement to energies greater than a few EeV. In this paper, we describe the detector, explain the technique, and present results from a measurement of the spectrum using ∼1000 hr of observation. The observed spectrum shows a clear steepening near 1017.1 eV, along with an ankle-like structure at 1016.2 eV. These features present important constraints on the origin of galactic cosmic rays and on propagation models. The feature at 1017.1 eV may also mark the end of the galactic cosmic ray flux and the start of the transition to extragalactic sources.
PDF
