221 research outputs found

    Disorder effects at low temperatures in La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3} manganites

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    With the aim of probing the effect of magnetic disorder in the low-temperature excitations of manganites, specific-heat measurements were performed in zero field, and in magnetic fields up to 9 T in polycrystalline samples of La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3}, with Y concentrations x=0, 0.10, and 0.15. Yttrium doping yielded the appearance of a cluster-glass state, giving rise to unusual low-temperature behavior of the specific-heat. The main feature observed in the results is a strong enhancement of the specific-heat linear term, which is interpreted as a direct consequence of magnetic disorder. The analysis was further corroborated by resistivity measurements in the same compounds.Comment: 9 pages, 2 figure

    Two pairs of proven monozygotic twins discordant for familial amyloid neuropathy (FAP) TTR Met 30.

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    J Med Genet. 1999 Aug;36(8):629-32. Two pairs of proven monozygotic twins discordant for familial amyloid neuropathy (FAP) TTR Met 30. Munar-Qués M, Pedrosa JL, Coelho T, Gusmão L, Seruca R, Amorim A, Sequeiros J. Grupo de Estudio de la PAF, Palma de Mallorca, Spain. Abstract Twin studies are an important tool in medical genetics for the evaluation of the relative roles of genetic and non-genetic factors in several diseases. Familial amyloidotic polyneuropathy type I (FAP-I), TTR Met 30, was present in two sets of proven monozygotic (MZ) twins, one from Majorca and the other from Portugal. Monozygosity was established by analysis of DNA polymorphisms. Both pairs were discordant for age at onset and some clinical manifestations of FAP-I. We reviewed the differences in age at onset and clinical features in both sets and in two other pairs of presumed MZ twins with FAP-I and compared them with those in MZ twin pairs with other Mendelian disorders, such as neurofibromatosis type 1, Huntington's disease, facioscapulohumeral muscular dystrophy, and myotonic dystrophy. We conclude that, in addition to the postulated modifying genes, there must be a significant contribution from non-genetic factors to the phenotypic variability of FAP-I (age at onset and clinical expression), either because of environmental differences or stochastic events during (or after) the twinning process. PMID: 10465115 [PubMed - indexed for MEDLINE]PMCID: PMC176297

    VAC14 Gene‐Related Parkinsonism‐Dystonia With Response to Deep Brain Stimulation

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    Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/150504/1/mdc312797-sup-0001-TableS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150504/2/mdc312797.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/150504/3/mdc312797_am.pd

    Comparação de acessos do gênero Paspalum quanto ao nível de antibiose à cigarrinha-das-pastagens Notozulia entreriana (Hemiptera: Cercopidae).

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    As cigarrinhas são pragas importantes e de ocorrência generalizada no Brasil. O uso de gramíneas resistentes é uma alternativa de controle que apresenta grande potencial. No presente ensaio, comparou-se 25 acessos do gênero Paspalum quanto ao nível de antibiose à cigarrinha Notozulia entreriana. Trata-se de acessos de espécies nativas de Paspalum como fonte de cultivares para fins paisagísticos e de recobrimento de superfícies de solo. O ensaio foi conduzido em casa de vegetação. As plantas foram estabelecidas a partir de mudas em pequenos copos plásticos e, posteriormente, transferidas para vasos maiores. Cada vaso foi individualmente coberto com tampa de alumínio possuindo orifício central, para a saída das planta

    MTSS1 is a critical epigenetically regulated tumor suppressor in CML

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    Chronic myeloid leukemia (CML) is driven by malignant stem cells that can persist despite therapy. We have identified Metastasis suppressor 1 (Mtss1/MIM) to be downregulated in hematopoietic stem and progenitor cells from leukemic transgenic SCLtTA/Bcr-Abl mice and in patients with CML at diagnosis, and Mtss1 was restored when patients achieved complete remission. Forced expression of Mtss1 decreased clonogenic capacity and motility of murine myeloid progenitor cells and reduced tumor growth. Viral transduction of Mtss1 into lineage depleted SCLtTA/Bcr-Abl bone marrow cells decreased leukemic cell burden in recipients, and leukemogenesis was reduced upon injection of Mtss1 overexpressing murine myeloid 32D cells. Tyrosine kinase inhibitor (TKI) therapy and reversion of Bcr-Abl expression increased Mtss1 expression but failed to restore it to control levels. CML patient samples revealed higher DNA methylation of specific Mtss1 promoter CpG sites that contain binding sites for Kaiso and Rest transcription factors. In summary, we identified a novel tumor suppressor in CML stem cells that is downregulated by both Bcr-Abl kinase-dependent and -independent mechanisms. Restored Mtss1 expression markedly inhibits primitive leukemic cell biology in vivo, providing a therapeutic rationale for the Bcr-Abl-Mtss1 axis to target TKI resistant CML stem cells in patients

    Differential Haematobia irritans infestation levels in beef cattle raised in silvopastoral and conventional pasture systems.

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    The use of silvopastoral systems (SPS) can be a good alternative to reduce the environmental impacts of livestock breeding in Brazil. One of the reasons for its scarce adoption is the lack of information on health and productivity of cattle raised under these conditions. The experiment reported here was designed to compare the infestation by external parasites ? the cattle tick (Rhipicephalus microplus), horn fly (Haematobia irritans), and larvae of the botfly (Dermatobia hominis) ? in beef cattle raised in a SPS and a conventional pasture system (CPS), evaluated for 24 months. Data on air and soil temperature, solar radiation, wind incidence and water balance were used to characterize the SPS and CPS. R. microplus adult females and D. hominis larvae were counted on the body of each animal to determine the parasites burdens, but we did not find significant differences between the two systems. Horn flies counts on animals? body, and analysis of the horn fly and its pupal parasitoids associated with the dung pats were obtained in the two systems. Horn fly infestation was significantly lower (p = 0.01) in the SPS (13.17 ± 3.46) in comparison with the CPS (24.02 ± 4.43). In SPS and CPS, respectively, the mean densities of pupae of H. irritansin dung pats were 9.8 and 10.7; the mean density of adults of H. irritans, 3.7 and 3.5; and the density of its pupal parasitoids were 20.5 and 5.4. The effect of production system was significant (p < 0.05) only for the occurrence of pupal parasitoids of the horn fly, where the greatest occurrences of these natural enemies were in the SPS. These data indicate that natural enemies were able to control, at least partially, the horn fly populations in the cattle

    Determinação da entomofauna associada ao bolo fecal de bovino em sistema convencional e integração pecuária floresta.

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    O impacto negativo da pecuária no meio ambiente tem sido mitigado através da combinação de pastagens e árvores, caracterizando os sistemas: Integração Pecuária-floresta (IPF) e Integração Lavoura-pecuária-floresta (ILPF), uma alternativa aos sistemas convencionais de pastagens
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