Antivortex Dynamics in Magnetic Nanostripes

In a thin magnetic nanostripe, an antivortex nucleates inside a moving domain wall when driven by an in-plane magnetic field greater than the so-called Walker field. The nucleated antivortex must cross the width of the nanostripe before the domain wall can propagate again, leading to low average domain wall speeds. A large out-of-plane magnetic field, applied perpendicularly to the plane of the nanostripe, inhibits the nucleation of the antivortex leading to fast domain wall speeds for all in-plane driving fields. We present micromagnetic simulation results relating the antivortex dynamics to the strength of the out-of-plane field. An asymmetry in the motion is observed which depends on the alignment of the antivortex core magnetic moments to the direction of the out-of-plane field. The size of the core is directly related to its crossing speed, both depending on the strength of the perpendicular field and the alignment of the core moments and direction of the out-of-plane field

Anti-vortex dynamics in magnetic nanostripes

In a thin magnetic nanostripe, an anti-vortex nucleates inside a moving domain wall when driven by an in-plane magnetic field greater than the so-called Walker field. The nucleated anti-vortex must cross the width of the nanostripe before the domain wall can propagate again, leading to low average domain wall speeds. A large out-of-plane magnetic field, applied perpendicularly to the plane of the nanostripe, inhibits the nucleation of the anti-vortex leading to fast domain wall speeds for all in-plane driving fields. We present micromagnetic simulation results relating the anti-vortex dynamics to the strength of the out-of-plane field. An asymmetry in the motion is observed which depends on the alignment of the anti-vortex core magnetic moments to the direction of the out-of-plane field. The size of the core is directly related to its crossing speed, both depending on the strength of the perpendicular field and the alignment of the core moments and direction of the out-of-plane field.Comment: 10 pages, 3 figure

Entre especialização e diversificação industrial: por um desenvolvimento regional durável

The article operates with the concepts of diversification and industrial specialization in the regional context, analyzing two areas of the state of Rio Grande do Sul: Caxias do Sul and the Sinos River Valley. It characterizes these areas, showing their vulnerabilities and potentialities in terms of a durable regional development. In the theoretical context in which the topic is located regional specialization has been considered as a factor that is highly favorable to the development of areas that aim at a competitive insertion in the global economy. Regional industrial diversification, however, is rarely pointed out by the literature as an advantage to be emphasized. Therefore, the author took two areas with quite different industrial profiles with the purpose of showing that the statement mentioned above is not an absolute truth. In other words, the article shows that the area of the Sinos Valley, which is specialized in the leather-footwear chain, presented great vulnerability to external factors by suffering the consequences of the oscillations of the international market, which jeopardizes its development in the medium and long term. In the diversified area of Caxias do Sul the situation is quite different, once its dynamism didn’t show strong variations. The stable growth of that area enables one to conclude that the industrial diversification had a balancing effect to a certain extent. The methodology adopted is based on data of RAIS on industrial jobs by municipality. Starting from them, location quotients were calculated and a typology (worked out by researchers of IBGE) was adapted in order to characterize the specialization/diversification of the municipalities. The article concentrates on the period 1990-2002, when the process of industrial restructuring caused important changes in the Brazilian economy, which makes it possible to discuss how those areas responded to the new reality.Key words: Regional economy; industrial diversification; local development.O texto trabalha com os conceitos de diversificação e de especialização industrial no âmbito regional, por meio da análise de duas regiões gaúchas: Caxias do Sul e Vale do Rio dos Sinos. Caracterizamos essas regiões, mostrando suas vulnerabilidades e suas potencialidades, na perspectiva de um desenvolvimento regional durável. No contexto teórico em que o tema está situado, a especialização regional tem sido considerada como fator altamente favorável ao desenvolvimento das regiões que visam a uma inserção competitiva na economia globalizada. A diversificação industrial regional, entretanto, raramente é apontada pela bibliografia como uma vantagem a ser enfatizada. Por isso, tomamos duas regiões, com perfis industriais bastante distintos, com o fito de mostrar que a assertiva acima não é uma verdade absoluta. Ou seja, nosso estudo constatou que a região especializada na cadeia produtiva coureiro-calçadista apresentou grande vulnerabilidade a fatores externos, sofrendo as conseqüências das oscilações do mercado internacional, o que compromete o seu desenvolvimento a médio e longo prazo. Quanto à região diversificada de Caxias do Sul, a situação é diferente, uma vez que seu dinamismo não apresentou fortes variações. O crescimento estável dessa região autoriza concluir que a diversificação industrial exerceu um papel equilibrador, em certa medida. Quanto à metodologia adotada, tomamos por base os dados da RAIS de emprego industrial por município e a partir deles calculamos os quocientes de localização, bem como adaptamos uma tipologia (elaboradapor pesquisadores do IBGE) para caracterizar a especialização/diversificação dos municípios. Privilegiamos o período 1990-2002, quando o processo de reestruturação industrial provocou importantes mudanças na economia brasileira, o que nos permite averiguar como foram as reações das regiões a essa nova realidade.Palavras-chave: Economia regional; diversificação industrial; desenvolvimento local

Entre especialização e diversificação industrial: por um desenvolvimento regional durável

The article operates with the concepts of diversification and industrial specialization in the regional context, analyzing two areas of the state of Rio Grande do Sul: Caxias do Sul and the Sinos River Valley. It characterizes these areas, showing their vulnerabilities and potentialities in terms of a durable regional development. In the theoretical context in which the topic is located regional specialization has been considered as a factor that is highly favorable to the development of areas that aim at a competitive insertion in the global economy. Regional industrial diversification, however, is rarely pointed out by the literature as an advantage to be emphasized. Therefore, the author took two areas with quite different industrial profiles with the purpose of showing that the statement mentioned above is not an absolute truth. In other words, the article shows that the area of the Sinos Valley, which is specialized in the leather-footwear chain, presented great vulnerability to external factors by suffering the consequences of the oscillations of the international market, which jeopardizes its development in the medium and long term. In the diversified area of Caxias do Sul the situation is quite different, once its dynamism didn’t show strong variations. The stable growth of that area enables one to conclude that the industrial diversification had a balancing effect to a certain extent. The methodology adopted is based on data of RAIS on industrial jobs by municipality. Starting from them, location quotients were calculated and a typology (worked out by researchers of IBGE) was adapted in order to characterize the specialization/diversification of the municipalities. The article concentrates on the period 1990-2002, when the process of industrial restructuring caused important changes in the Brazilian economy, which makes it possible to discuss how those areas responded to the new reality.Key words: Regional economy; industrial diversification; local development.O texto trabalha com os conceitos de diversificação e de especialização industrial no âmbito regional, por meio da análise de duas regiões gaúchas: Caxias do Sul e Vale do Rio dos Sinos. Caracterizamos essas regiões, mostrando suas vulnerabilidades e suas potencialidades, na perspectiva de um desenvolvimento regional durável. No contexto teórico em que o tema está situado, a especialização regional tem sido considerada como fator altamente favorável ao desenvolvimento das regiões que visam a uma inserção competitiva na economia globalizada. A diversificação industrial regional, entretanto, raramente é apontada pela bibliografia como uma vantagem a ser enfatizada. Por isso, tomamos duas regiões, com perfis industriais bastante distintos, com o fito de mostrar que a assertiva acima não é uma verdade absoluta. Ou seja, nosso estudo constatou que a região especializada na cadeia produtiva coureiro-calçadista apresentou grande vulnerabilidade a fatores externos, sofrendo as conseqüências das oscilações do mercado internacional, o que compromete o seu desenvolvimento a médio e longo prazo. Quanto à região diversificada de Caxias do Sul, a situação é diferente, uma vez que seu dinamismo não apresentou fortes variações. O crescimento estável dessa região autoriza concluir que a diversificação industrial exerceu um papel equilibrador, em certa medida. Quanto à metodologia adotada, tomamos por base os dados da RAIS de emprego industrial por município e a partir deles calculamos os quocientes de localização, bem como adaptamos uma tipologia (elaboradapor pesquisadores do IBGE) para caracterizar a especialização/diversificação dos municípios. Privilegiamos o período 1990-2002, quando o processo de reestruturação industrial provocou importantes mudanças na economia brasileira, o que nos permite averiguar como foram as reações das regiões a essa nova realidade.Palavras-chave: Economia regional; diversificação industrial; desenvolvimento local

Deformation and phase transformation in polycrystalline cementite (Fe3_{3}C) during single- and multi-pass sliding wear

Cementite (Fe$_{3}$C) plays a major role in the tribological performance of rail and bearing steels. Nonetheless, the current understanding of its deformation behavior during wear is limited because it is conventionally embedded in a matrix. Here, we investigate the deformation and chemical evolution of bulk polycrystalline cementite during single-pass sliding at a contact pressure of 31 GPa and reciprocating multi-pass sliding at 3.3 GPa. The deformation behavior of cementite was studied by electron backscatter diffraction for slip trace analysis and transmission electron microscopy. Our results demonstrate activation of several deformation mechanisms below the contact surface: dislocation slip, shear band formation, fragmentation, grain boundary sliding, and grain rotation. During sliding wear, cementite ductility is enhanced due to the confined volume, shear/compression domination, and potentially frictional heating. The microstructural alterations during multi-pass wear increase the subsurface nanoindentation hardness by up to 2.7 GPa. In addition, we report Hägg carbide (Fe$_{5}$C$_{2}$) formation in the uppermost deformed regions after both sliding experiments. Based on the results of electron and X-ray diffraction, as well as atom probe tomography, we propose potential sources of excess carbon and mechanisms that promote the phase transformation

Enhancement of vaccinia virus based oncolysis with histone deacetylase inhibitors

Histone deacetylase inhibitors (HDI) dampen cellular innate immune response by decreasing interferon production and have been shown to increase the growth of vesicular stomatitis virus and HSV. As attenuated tumour-selective oncolytic vaccinia viruses (VV) are already undergoing clinical evaluation, the goal of this study is to determine whether HDI can also enhance the potency of these poxviruses in infection-resistant cancer cell lines. Multiple HDIs were tested and Trichostatin A (TSA) was found to potently enhance the spread and replication of a tumour selective vaccinia virus in several infection-resistant cancer cell lines. TSA significantly decreased the number of lung metastases in a syngeneic B16F10LacZ lung metastasis model yet did not increase the replication of vaccinia in normal tissues. The combination of TSA and VV increased survival of mice harbouring human HCT116 colon tumour xenografts as compared to mice treated with either agent alone. We conclude that TSA can selectively and effectively enhance the replication and spread of oncolytic vaccinia virus in cancer cells. © 2010 MacTavish et al

Uterine Leiomyosarcoma

Uterine leiomyosarcoma (uLMS) is a rare entity among malignant gynecologic tumors with a very unfavorable prognosis and the highest prevalence in the pre- and peri-menopause. Only early-stage tumors have an acceptable prognosis, provided the patient has been treated without injuring the uterus. uLMS is often diagnosed accidentally and the correct diagnosis ishampered by equivocal features similar to the far more frequent benign uterine fibroids. Surgery is the basis of therapy, and it should be done in order to remove the uterus intact. As vaginal, abdominal, and endoscopic surgery – possibly including morcellation – are the methods of choice for the treatment of uterine fibroids, pre-operatively undiagnosed leiomyosarcoma detected by pathologic examination will have a worsened prognosis. Systemic treatment and radiotherapy are of no proven value in the adjuvant setting. Thus, there is strong need for a reliable pre-operative risk score for leiomyosarcoma in order to justify diagnostic means beyond clinical routine and to choose the correct surgical pathway. The clinical problems in the diagnosis of leiomyosarcoma and treatment are exemplified by a case report of a 30-year-old childless patient. Diagnostic tools as well as treatment options in adjuvant and palliative situations are reviewed

Seroprevalence of Zika virus in wild African green monkeys and baboons

ABSTRACT Zika virus (ZIKV) has recently spread through the Americas and has been associated with a range of health effects, including birth defects in children born to women infected during pregnancy. Although the natural reservoir of ZIKV remains poorly defined, the virus was first identified in a captive “sentinel” macaque monkey in Africa in 1947. However, the virus has not been reported in humans or nonhuman primates (NHPs) in Africa outside Gabon in over a decade. Here, we examine ZIKV infection in 239 wild baboons and African green monkeys from South Africa, the Gambia, Tanzania, and Zambia using combinations of unbiased deep sequencing, quantitative reverse transcription-PCR (qRT-PCR), and an antibody capture assay that we optimized using serum collected from captive macaque monkeys exposed to ZIKV, dengue virus, and yellow fever virus. While we did not find evidence of active ZIKV infection in wild NHPs in Africa, we found variable ZIKV seropositivity of up to 16% in some of the NHP populations sampled. We anticipate that these results and the methodology described within will help in continued efforts to determine the prevalence, natural reservoir, and transmission dynamics of ZIKV in Africa and elsewhere. IMPORTANCE Zika virus (ZIKV) is a mosquito-borne virus originally discovered in a captive monkey living in the Zika Forest of Uganda, Africa, in 1947. Recently, an outbreak in South America has shown that ZIKV infection can cause myriad health effects, including birth defects in the children of women infected during pregnancy. Here, we sought to investigate ZIKV infection in wild African primates to better understand its emergence and spread, looking for evidence of active or prior infection. Our results suggest that up to 16% of some populations of nonhuman primate were, at some point, exposed to ZIKV. We anticipate that this study will be useful for future studies that examine the spread of infections from wild animals to humans in general and those studying ZIKV in primates in particular. Podcast: A podcast concerning this article is available

DNA alkylation and interstrand cross-linking by treosulfan

The anti-tumour drug treosulfan (L-threitol 1,4-bismethanesulphonate, Ovastat) is a prodrug for epoxy compounds by converting non-enzymatically to L-diepoxybutane via the corresponding monoepoxide under physiological conditions. The present study supports the hypothesis that this conversion of treosulfan is required for cytotoxicity in vitro. DNA alkylation and interstrand cross-linking of plasmid DNA is observed after treosulfan treatment, but this is again produced via the epoxide species. Alkylation occurs at guanine bases with a sequence selectivity similar to other alkylating agents such as the nitrogen mustards. In treosulfan-treated K562 cells, cross-links form slowly, reaching a peak at approximately 24 h. Incubation of K562 cells with preformed epoxides shows faster and more efficient DNA cross-linking. © 1999 Cancer Research Campaig