Spectral Comparison of Weak Short Bursts to the Persistent X-rays from the Magnetar 1E 1547.0-5408 in its 2009 Outburst

In January 2009, the 2.1-sec anomalous X-ray pulsar 1E 1547.0-5408 evoked intense burst activity. A follow-up Suzaku observation on January 28 recorded enhanced persistent emission both in soft and hard X-rays (Enoto et al. 2010b). Through re-analysis of the same Suzaku data, 18 short bursts were identified in the X-ray events recorded by the Hard X-ray Detector (HXD) and the X-ray Imaging Spectrometer (XIS). Their spectral peaks appear in the HXD-PIN band, and their 10-70 keV X-ray fluences range from ~2e-9 erg cm-2 to 1e-7 erg cm-2. Thus, the 18 events define a significantly weaker burst sample than was ever obtained, ~1e-8-1e-4 erg cm-2. In the ~0.8 to ~300 keV band, the spectra of the three brightest bursts can be represented successfully by a two-blackbody model, or a few alternative ones. A spectrum constructed by stacking 13 weaker short bursts with fluences in the range (0.2-2)e-8 erg s-1 is less curved, and its ratio to the persistent emission spectrum becomes constant at ~170 above ~8 keV. As a result, the two-blackbody model was able to reproduce the stacked weaker-burst spectrum only after adding a power-law model, of which the photon index is fixed at 1.54 as measured is the persistent spectrum. These results imply a possibility that the spectrum composition employing an optically-thick component and a hard power-law component can describe wide-band spectra of both the persistent and weak-burst emissions, despite a difference of their fluxes by two orders of magnitude. Based on the spectral similarity, a possible connection between the unresolved short bursts and the persistent emission is discussed.Comment: 21 pages, 18 figures and 3 tables. Accepted for publication in Monthly Notices of the Royal Astronomical Society Main Journa

Identification of an isoform with an extremely large Cys-rich region of PC6, a Kex2-like processing endoprotease

AbstractIn the previous study [1993, J. Biochem. (Tokyo) 113, 132-135] we identified PC6, a member of the Kex2 family of processing endoproteases. In this study, we identified another cDNA encoding an isoform of PC6, and designated it as PC6B and redesignated the originally identified PC6 as PC6A. PC6B had a very large Cys-rich region consisting of 22-times repeats of a Cys-rich motif, and a putative transmembrane domain which is not present in PC6A. A PC6B transcript was found mainly in the intestine, while PC6A transcripts were in various tissues. These results suggest distinct roles of PC6A and PC6B in endoproteolytic processing of precursor proteins

The Suzaku Discovery of A Hard Power-Law Component in the Spectra of Short Bursts from SGR 0501+4516

Using data with the Suzaku XIS and HXD, spectral studies of short bursts from the soft gamma repeater SGR 0501+4516 were performed. In total, 32 bursts were detected during the ~60 ks of observation conducted in the 2008 August activity. Excluding the strongest one, the remaining 31 bursts showed an average 2--40 keV fluence of 1.0(-0.5,+0.3)*10^-9 erg cm^-2. A 1--40 keV spectrum summed over them leaves significant positive residuals in the HXD-PIN band with chi^2/d.o.f. = 74/50, when fitted with a two-blackbody function. By adding a power law model, the fit became acceptable with chi^2/d.o.f. = 56/48, yielding a photon index of Gamma=1.0(-0.3,+0.4). This photon index is comparable to Gamma=1.33(-0.16,+0.23) (Enoto et al. 2010a) for the persistent emission of the same object obtained with Suzaku. The two-blackbody components showed very similar ratios, both in the temperature and the emission radii, to those comprising the persistent emission. However, the power-law to two-blackbody flux ratio was possibly higher than that of the persistent emission at 2.6 sigma level. Based on these measurements, average wide-band properties of these relatively weak bursts are compared with those of the persistent emission.Comment: 11 pages, 8 figures, 2 tables, Accepted for publication in PASJ (Suzaku & MAXI special issue

Biologia populacional do predador invasor Micropterus salmoides (Lacépède, 1802) em um reservatório Neotropical usando marcação e recaptura

Orientador : Jean Ricardo Simões VituleDissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Ecologia e Conservação. Defesa: Curitiba, 04/03/2016Inclui referências : f. 26-34Resumo: A introdução de espécies não nativas é um grande problema para conservação da biodiversidade, sendo considerado um dos maiores desafios para ecologia e sociedade. Dentre as espécies com alto potencial invasor e histórico catastrófico onde foi introduzido, destaca-se a espécie Micropterus salmoides (Lacépède 1802) ou black bass, como é conhecida no Brasil, a qual tem conseguido se estabelecer com sucesso e gerado impactos negativos sobre populações nativas em mais de 50 países. Neste contexto, o objetivo desse trabalho foi levantar informações populacionais de M. salmoides, a fim de avaliar o potencial invasor da espécie, a intensidade dos seus impactos e auxiliar na elaboração de propostas de manejo e redução de impactos negativos gerados. Foram estudados: tamanho populacional, taxa de crescimento, padrão de distribuição e potencial de mobilidade em um reservatório Neotropical, localizado na ecorregião do Rio Iguaçu, sul do Brasil. As amostragens foram realizadas pela da técnica de captura-marcação-recaptura, através de pesca com iscas artificiais. Foram capturados e marcados 1803 indivíduos dos quais 109 foram recapturados uma única vez (6,04%) e apenas três indivíduos foram recapturados duas vezes (0,16%). O tamanho populacional estimado foi de aproximadamente 9057 indivíduos, podendo variar entre 6748 e 12201 indivíduos. Com base nesta estimativa a densidade populacional foi de 9 indivíduos ha-1 e pode variar entre 6,7 e 12,2 indivíduos ha-1. A taxa de crescimento corporal não variou entre os indivíduos e a média foi de 0,38 mm/dia e 1,46 g/dia. Em relação ao potencial de mobilidade da espécie, a distância máxima percorrida foi de 6987 m em um intervalo de 38 dias. Já a maior distância percorrida no menor intervalo de tempo foi de 2213 m em dois dias. A população de M. salmoides encontrou condições ideais que garantiram o sucesso de colonização e reprodução e podem permitir que atinja densidades maiores no reservatório Passaúna do que em ecossistemas onde é nativa. Além disso, tais condições estimularam o seu crescimento corporal. Os indivíduos adultos de M. salmoides possuem grande potencial de mobilidade, o que aumenta o potencial invasor da espécie. Quanto à distribuição dos indivíduos no reservatório, podemos considerá-la uniforme. Por fim, são sugeridas algumas medidas que visam minimizar e/ou controlar o possível impacto gerado por M. salmoides no reservatório, tais como educação ambiental, regulamentação da pesca e controle de espécies não nativas. Palavras-chave: invasão; manejo; movimentação; distribuição despótica; pesca com isca artificial; taxa de crescimento.Abstract: The introduction of non-native species is a great problem for the conservation of the biodiversity and it has been considered one of the biggest challenges for ecology and society. Among the species with high potential of invisibility and harmful to the environment where it has been introduced, stands out the specie Micropterus salmoides (Lacépède 1802) or "black bass", as it is commonly known in Brazil. Populations of this fish has been established in more than 50 countries, causing negative impacts over the native species. In this context, the goal of this study was to gather informations about populations of M. salmoides in a reservoir, including evaluate the potential of its invasibility, the intensity of its impacts and to provide valuable information for the creation of management plans, as an attempt to reduce its negative impacts. In order to achieve that, it was taken in to account: the size of the population, growth rate, distribution patterns and mobility within a neotropical reservoir, situated in the ecoregion of the Iguaçu River, southern Brazil. The sampling was taken by capturing, marking and recapturing the fishes, using fishing techniques with rod and artificial lures. In total, it was captured and marked 1803 individuals of which 109 were recapture at least once [6.04%] and only three individual were recapture twice [0.16%]. The estimated size of the population was approximately 9057 individuals, ranging between 6748 and 12201. Based on this estimate, the population density within the reservoir was 9 individuals perha-1, varying between 6.7 and 12.2 individuals perha-1. Growth rates did not vary among the animals and the mean growth rate measured was 0.38 mm/day e 1.46 g/day. In relation to the mobility of the specie, the maximum distance travelled by one fish was 6987 meters within 38 days. However, the further distance travelled within the short test interval of time was 2213 meters in 2 days. The ideal conditions of the reservoir ensure the population of M. salmoides to succeed, being able to colonize and reproduce. The specie may reach higher densities in the reservoir of Passaúna than its natural environment, in North America. Besides, conditions of the reservoir has stimulated he body growth of the specie. Adults of M. salmoides may have great potential of mobility, resulting in an increase of its invasibility. The distributions of the individuals in the reservoir may be considered uniform throughout its extension. Lastly, management actions that aim to minimize and/ or to control the ecological impact of the M. Salmoides among others native species in the reservoir are suggested, such as environmental education, fishing regulamentations and control of non native species. Key-words: invasion; manegement; movement; despotic distribution; artificial lures fishing; growth rat

Cisplatin, rather than oxaliplatin, increases paracellular permeability of LLC-PK1 cells via activating protein kinase C

The clinical use of cisplatin is limited by its adverse events, particularly serious nephrotoxicity. It was clarified that cisplatin is transported by a kidney-specific organic cation transporter (OCT2). OCT2 also mediates the uptake of oxaliplatin into renal proximal tubular cells; however, this agent does not lead nephrotoxicity. In the present study, we carried out comparative experiments with cisplatin and oxaliplatin using porcine kidney LLC-PK1 cell monolayers. In the fluorescein-labeled isothiocyanate-dextran flux assay, the basolateral application of cisplatin, but not oxaliplatin, resulted in an increase in the paracellular permeability of cell monolayers. Even though the cellular accumulation of platinum at 50 μM oxaliplatin could reach the same level at 30 μM cisplatin, oxaliplatin did not induce hyper-permeability in cell monolayers. Cisplatin, but not oxaliplatin, significantly activated PKC. In addition, the combination of PKC inhibitors recovered the increase in paracellular permeability. In conclusion, pharmacodynamic mechanisms via PKC could explain the difference in nephrotoxicity between cisplatin and oxaliplatin

Suzaku Discovery of a Hard X-Ray Tail in the Persistent Spectra from the Magnetar 1E 1547.0-5408 during its 2009 Activity

The fastest-rotating magnetar 1E 1547.0-5408 was observed in broad-band X-rays with Suzaku for 33 ks on 2009 January 28-29, 7 days after the onset of its latest bursting activity. After removing burst events, the absorption-uncorrected 2-10 keV flux of the persistent emission was measured with the XIS as 5.7e-11 ergs cm-2 s-1, which is 1-2 orders of magnitude higher than was measured in 2006 and 2007 when the source was less active. The persistent emission was also detected significantly with the HXD in >10 keV up to at least ~110 keV, with an even higher flux of 1.3e-10 ergs cm-2 s-1 in 20-100 keV. The pulsation was detected at least up to 70 keV at a period of 2.072135+/-0.00005 s, with a deeper modulation than was measured in a fainter state. The phase-averaged 0.7-114 keV spectrum was reproduced by an absorbed blackbody emission with a temperature of 0.65+/-0.02 keV, plus a hard power-law with a photon index of ~1.5. At a distance of 9 kpc, the bolometric luminosity of the blackbody and the 2-100 keV luminosity of the hard power-law are estimated as (6.2+/-1.2)e+35 ergs s-1 and 1.9e+36 ergs s-1, respectively, while the blackbody radius becomes ~5 km. Although the source had not been detected significantly in hard X-rays during the past fainter states, a comparison of the present and past spectra in energies below 10 keV suggests that the hard component is more enhanced than the soft X-ray component during the persistent activity.Comment: 12 pages, 7 figures, PASJ Vol.62 No.2 accepte

Effect of riboflavin deficiency on development of the cerebral cortex in Slc52a3 knockout mice

Riboflavin transporter 3 (RFVT3), encoded by the SLC52A3 gene, is important for riboflavin homeostasis in the small intestine, kidney, and placenta. Our previous study demonstrated that Slc52a3 knockout (Slc52a3−/−) mice exhibited neonatal lethality and metabolic disorder due to riboflavin deficiency. Here, we investigated the influence of Slc52a3 gene disruption on brain development using Slc52a3−/− embryos. Slc52a3−/− mice at postnatal day 0 showed hypoplasia of the brain and reduced thickness of cortical layers. At embryonic day 13.5, the formation of Tuj1+ neurons and Tbr2+ intermediate neural progenitors was significantly decreased; no significant difference was observed in the total number and proliferative rate of Pax6+ radial glia. Importantly, the hypoplastic phenotype was rescued upon riboflavin supplementation. Thus, it can be concluded that RFVT3 contributes to riboflavin homeostasis in embryos and that riboflavin itself is required during embryonic development of the cerebral cortex in mice

ナンジセイ コケイガン ニ タイスル ガン コウゲン ペプチドパルス ジュジョウ サイボウ オ モチイタ ガン ワクチン リョウホウ : トランスレーショナル リサーチ トシテノ テンカイ

Dendritic cells (DCs) are the most potent antigen-presenting cells. DCs pulsed with peptides of tumor-associated antigens (TAA) have been used in cancer immunotherapy. An early clinical study demonstrated the safety of these trials, but the clinical effect was not sufficient. Most studies have used immature DCs generated from peripheral blood monocytes with granulocyte-macrophage colony-stimulating factor (GM-CSF) and interleukin-4 (IL-4). Here, we conducted phase I clinical trial of active immunotherapy using mature DCs induced by a streptococcus derivatives OK-432. DCs were generated from blood monocytes by culturing with GM-CSF and IL-4 for 6 days and then GM-CSF, IL-4 and OK-432 for 2 days. Before injection, DCs were pulsed with MAGE-3 peptide (IMPKAGLLI), which is restricted for HLA-A*2402, and keyhole limpet hemocyanin (KLH) as a control antigen. We selected HLA-A*2402-positive patients who had advanced solid tumors expressing MAGE-3 mRNA. DC vaccine was administered subcutaneously every 2 weeks for a total of four vaccinations in a dose-escalation design at the dose level per cohort of 0.1 (Group 1), 0.3 (Group 2) and 1 (Group 3) ×10８DCs/injection. Immunological monitoring with delayed type hypersensitivity (DTH) reaction and MHC tetramer was performed. Three patients with advanced solid tumor (two lung cancer and one melanoma patients) were so far enrolled in Group 1 of this study. This protocol was well tolerated. A mild fever (Grade 1 to 2) and local reaction of injection site (erythema and induration : Grade 1) were found in all patients. DTH for MAGE-3 peptide became to be positive after forth vaccination in one patient. The decrease of tumor marker (CEA) was found in one patient. However, clinical responses in all three patients were not observed. These results indicated that vaccination with mature DCs (0.1×10８DCs/injection) was safe and feasible, but further analysis using the higher dose of DCs was required to assess the immunological and clinical responses