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Sample records for bvdv field strains

  1. Changes observed in the thymus and lymph nodes 14 days after exposure to BVDV field strains of enhanced or typical virulence in neonatal calves

    Science.gov (United States)

    Clinical presentation following uncomplicated acute infection with bovine viral diarrhea viruses (BVDV) ranges from clinically unapparent to severe (including hemorrhagic disease and death) depending on the strain virulence. Regardless of clinical presentation, BVDV infection of cattle results in i...

  2. Peripheral blood mononuclear cells from field cattle immune to bovine viral diarrhea virus (BVDV) are permissive in vitro to BVDV.

    Science.gov (United States)

    Gupta, V; Mishra, N; Pateriya, A; Behera, S P; Rajukumar, K

    2014-01-01

    The aim of this study was to determine the in vitro permissivity of peripheral blood mononuclear cells (PBMCs) from bovine viral diarrhea virus (BVDV)-immune field cattle to homologous and heterologous BVDVs. PBMCs from seventeen BVDV-naïve and sixteen BVDV-immune animals were infected with noncytopathic BVDV-1 or BVDV-2. The immune status of cattle was indicated by the presence of virus neutralizing antibodies, while viral load of PBMCs was determined by real-time RT-PCR. The results revealed that the PBMCs from naïve or immune animals were permissive to either BVDV-1 or BVDV-2, but the viral load was significantly higher for the naïve than for the immune animals. Furthermore, the load of homologous virus in PBMCs from immune animals was lower than that of heterologous virus. Our results provide evidence that the PBMCs from BVDV-immune cattle in field are susceptible to reinfection with homologous or heterologous BVDV, albeit to a lower extent in the former case.

  3. Failed detection of Bovine viral diarrhea virus 2 subgenotype a (BVDV-2a) by direct fluorescent antibody test on tissue samples due to reduced reactivity of field isolates to raw anti-BVDV antibody.

    Science.gov (United States)

    Yan, Lifang; Pace, Lanny W; Baughman, Brittany; Wilson, Floyd D; Zhang, Shuping; Zhang, Michael Z

    2016-03-01

    Bovine viral diarrhea virus 1 (BVDV-1) is associated with mild or subclinical infections, whereas BVDV-2 is frequently implicated in outbreaks of severe thrombocytopenia and acute fatal disease. In the present study, the carcass of a beef breed cow and tissue samples of a beef calf were received for laboratory diagnosis. Both animals exhibited severe clinical signs compatible with thrombocytopenia or hemorrhagic syndrome. Direct fluorescent antibody test (DFAT) failed to detect BVDV antigen in the tissue specimens of both cases. However, immunohistochemistry (IHC) revealed the presence of BVDV antigen in oral and esophageal mucosa and Peyer patches of the beef breed cow. Real-time reverse transcription polymerase chain reaction (real-time RT-PCR) detected BVDV-2 in selected tissues of both animals. Subsequently, BVDV was isolated from both cases and subjected to genetic and serologic characterizations. Mutations in the 5'-untranslated genomic region (5'-UTR) primer and probe binding sites and the E2 gene were associated with reduced efficiency of an established real-time RT-PCR assay and amino acid alterations in the E2 glycoprotein, respectively. Both viral isolates were classified by real-time RT-PCR and phylogenetic analysis as BVDV-2 subgenotype a. Unlike BVDV reference strains Singer and 125c, the isolates cross-reacted with anti-BVDV-1 and anti-BVDV-2 reference sera, indicating antigenic variations in field isolates. The isolates also showed reduced reactivity to porcine anti-BVDV antiserum (the raw serum used to produce BVDV DFA conjugate). In summary, data from the present investigation indicated that genetic and antigenic variations affected the performance of detection assays, especially DFAT, highlighting the need for regular evaluation and modification of BVDV tests. PMID:26965235

  4. Bovine viral diarrhea virus in postweaned calves in a feedlot after vaccination and from fatal respiratory cases: isolation and differentiation of MLV BVDV and field strains

    Science.gov (United States)

    Viral infections are important etiologies in BRD cases. Calves at stocker/feedlot entry usually receive modified live viral (MLV) vaccines containing bovine herpesvirus-1 (BoHV-1), parainfluenza-3 virus (PI3V), bovine viral diarrhea viruses (BVDV), and bovine respiratory syncytial virus (BRSV). In...

  5. Cytopathic BVDV-1 strain induces immune marker production in bovine cells through the NF-κB signaling pathway.

    Science.gov (United States)

    Fredericksen, Fernanda; Carrasco, Gonzalo; Villalba, Melina; Olavarría, Víctor H

    2015-12-01

    The bovine viral diarrhea virus (BVDV-1) is a pathogen responsible for high economic losses in the cattle industry worldwide. This virus has the capacity to modulate the immune system of several higher vertebrates, but there is little information available on the cell infection mechanism. To further investigate the effects of BVDV-1 on the activation of the immune response, the Madin-Darby bovine kidney cell line was infected with the cytopathic CH001 field isolate of BVDV-1, and the proinflammatory and antiviral cytokine expression profiles were analyzed. The results showed that BVDV-1 was able to induce the production of BCL3, IL-1β, IL-8, IL-15, IL-18, Mx-1, IRF-1, and IRF-7 in a way similar to polyinosinic-polycytidylic acid. Interestingly, all BVDV-1 activities were blocked by pharmacological inhibitors of the NF-κB signaling pathway. These results, together with in silico analyses showing the presence of several regulatory consensus target motifs, suggest that BVDV-1 regulates gene expression in bovines through the activation of several key transcription factors. Collectively, these data identified BVDV-1 as a viral regulator of immune marker expression, even from early infection. Additionally, this is the first report to find BVDV-1 modulating the activation of cytokine production and transcriptions factors mainly through the NF-κB pathway in vertebrates. PMID:26330089

  6. Role of thymic epithelial cells in lymphoid depletion after experimental infection with the noncytopathogenic BVDV1 strain 7443.

    Science.gov (United States)

    Raya, A I; Gomez-Villamandos, J C; Bautista, M J

    2015-03-01

    Thymic epithelial cells could play an important role in lymphoid depletion during bovine viral diarrhea virus (BVDV) infection. To evaluate this hypothesis, we examined proliferation of lymphocytes, expression of cytokeratins by thymic epithelial cells, and ultrastructural features at sequential time points after experimental infection of colostrum-deprived calves with the noncytopathogenic BVDV1 strain 7443. Ten clinically healthy Friesian calves were used. Eight were inoculated with the virus, and 2 were used as uninfected controls. Calves were sedated and euthanized in batches between 3 and 14 days postinoculation. At necropsy, thymus samples were collected for structural, immunohistochemical, and ultrastructural study. Thymic lymphoid depletion was accompanied by a decrease in lymphocyte proliferation and immunohistochemical and ultrastructural changes in thymic epithelial cells. Immunohistochemical and ultrastructural results reflect a disturbance of the thymic epithelial cell network, which may explain the decrease in lymphocyte proliferation by defective thymocyte-epithelial cell interactions. PMID:24842487

  7. 牛病毒性腹泻病毒BVDV2/JZ05-2毒株牛感染模型建立%Bovine Viral Diarrhea Virus BVDV2/JZ05-2 Strain Infection Modeling

    Institute of Scientific and Technical Information of China (English)

    冯卓; 刘艳环; 朱言柱; 李海涛; 钟宏鹏; 王坤; 张润祥; 苗利光

    2013-01-01

    试验用4~6月龄健康牛22头,共分5组,4个试验组5头/组,对照组2头。各试验组分别鼻内接种强毒107 FAID50/mL、106 FAID50/mL、105 FAID50/mL、104 FAID50/mL ,4mL/头,2mL/鼻孔。对照组鼻内接种MDBK细胞培养液冻融物,4mL/头,2mL/鼻孔。试验动物接种强毒后,每天观察实验动物的反应,包括精神状态、体温、食欲、黏膜颜色、呼吸频率、咳嗽、鼻腔分泌物及腹泻等;每天采集鼻拭子用于病毒分离。攻毒前2d、0d ,攻毒后隔天采血用于白细胞计数和病毒分离;试验于病毒接种后14d结束。试验过程中如有动物死亡,对死亡动物进行病理学检查。结果,106.6 FAID50/头BVDV2/JZ05-2攻击4~9月龄的牛,可引起被攻击牛有规律地体温升高和白细胞数量下降,同时可以从鼻拭子中分离到病毒。以这些指标作为感染模型可以有效地评价BVDV2疫苗免疫效果。%The aim of this experiment was to build bovine viral diarrhea virus BVDV 2/JZ05-2 strain infection model .Twenty two healthy cattle (4~6 months old ) were divided into 5 groups .In four experimental groups ,each group had 5 cattle .The control group had 2 cattle .The con-centrations of the BVDV2/JZ05-2 strain used in the experimental groups were 107 FAID50/mL ,106 FAID50/mL ,105 FAID50/mL ,104 FAID50/mL ,respectively .In control group ,the cattle were given MDBK nutrient solution .The volume of the sample was 4 mL through intranasal in dif-ferent groups .After inoculated the strong virus ,the clinical symptom was recorded everyday .The clinical symptom included psychosis ,tempera-ture ,appetite ,mucosa colour ,respiratory rate ,cough ,nasal cavity secreta and diarrhea .Nose swab was collected to separate the strong virus ev-eryday .The blood was obtained to determine white blood cell count and separate virus in -2 day ,0 day and 2 day .After the virus was inoculat-ed for 14 days ,the experiment was finished .If the dead cattle

  8. Immunology of BVDV vaccines.

    Science.gov (United States)

    Ridpath, Julia F

    2013-01-01

    Providing acquired immune protection against infection with bovine viral diarrhea viruses (BVDV) is challenging due to the heterogeneity that exists among BVDV strains and the ability of the virus to infect the fetus and establish persistent infections. Both modified live and killed vaccines have been shown to be efficacious under controlled conditions. Both humoral and cellular immune responses are protective. Following natural infection or vaccination with a modified live vaccine, the majority of the B cell response (as measured by serum antibodies) is directed against the viral proteins E2 and NS2/3, with minor responses against the Erns and E1 proteins. Vaccination with killed vaccines results in serum antibodies directed mainly at the E2 protein. It appears that the major neutralizing epitopes are conformational and are located within the N-terminal half of the E2 protein. While it is thought that the E2 and NS2/3 proteins induce protective T cell responses, these epitopes have not been mapped. Prevention of fetal infections requires T and B cell response levels that approach sterilizing immunity. The heterogeneity that exists among circulating BVDV strains, works against establishing such immunity. Vaccination, while not 100% effective in every individual animal, is effective at the herd level. PMID:22883306

  9. Limited BVDV transmission and full protection against CSFV transmission in pigs experimentally infected with BVDV type 1b

    NARCIS (Netherlands)

    Wieringa-Jelsma, H.; Quak, J.; Loeffen, W.L.A.

    2006-01-01

    Bovine viral diarrhea virus (BVDV) in pigs may interfere with the detection and epidemiology of classical swine fever virus (CSFV). To investigate the importance of BVDV infections in pigs, first we studied the transmission dynamics of a recent BVDV field isolate. Subsequently, the protection of BVD

  10. Diagnosing BVDV infections

    Science.gov (United States)

    Infections with bovine viral diarrhea viruses (BVDV) are widespread among the U.S. cattle population and it is generally accepted that these infections result in substantial economic loss for producers. There is a push in the U.S. to design BVDV control programs that will curb these losses. While ...

  11. Diversidade antigênica de amostras do vírus da diarréia viral bovina isoladas no Brasil: implicações para o diagnóstico e estratégias de imunização Antigenic diversity of Brazilian isolates of bovine viral diarrhea virus (BVDV: implications for diagnosis and immunization strategies

    Directory of Open Access Journals (Sweden)

    E.F. Flores

    2000-02-01

    Europe, suggesting they might belong to a new subgenotype. Antigenic characterization of these isolates by cross-neutralization revealed a very low serologic cross-reactivity with vaccine BVDV strains. The immune serum raised in lambs to three vaccine strains presented a very low and even negligible neutralizing activity against some Brazilian BVDV type 1 and 2 isolates. Up to 128-fold differences in serum neutralizing antibody titers were observed between the vaccine strains and some Brazilian BVDV isolates. The potential impact of the antigenic variability of BVDV on serologic diagnosis was investigated by testing field serum samples by serum-neutralization (SN against viruses of both genotypes. Two hundred and eighty samples (24.7% had neutralizing antibodies against BVDV. Out of these, 215 (76.8% had neutralizing activity against viruses of both genotypes, 37 samples (13.2% reacted only against BVDV type 2 and 28 (10% were positive only to BVDV type 1. These results demonstrate that SN tests using only one virus may result in a significant number of false-negative results. The reduced neutralizing activity of the antisera to vaccine strains against some Brazilian isolates raises the question about the degree of protection conferred by these vaccines and indicates the need of producing vaccines based on local viruses and/or including viruses of both genotypes.

  12. Serological relationships among subgroups in bovine viral diarrhea virus genotype 1 (BVDV-1).

    Science.gov (United States)

    Alpay, Gizem; Yeşilbağ, Kadir

    2015-01-30

    Bovine viral diarrhea virus (BVDV) has various economic impacts associated with diarrhea, poor performance, an increase in the frequency of other infections and lethal outcomes. Both genotypes, namely BVDV-1 and BVDV-2, as well as different subgroups within these genotypes have been reported worldwide. Understanding the serological differences among the BVDV subgroups is important for disease epidemiology and prevention as well as vaccination programs. The aim of this study was to determine the serological relatedness among the subgroups in BVDV-1. For that purpose, sheep hyperimmune sera were collected against representative strains from 6 of the subgroups of BVDV-1 (BVDV-1a, -1b, -1d, -1f, -1h and -1l). The serum samples that gave the peak antibody titer to the homologous strains were used to perform cross neutralization assays. The highest homologous antibody titer (1:5160) was obtained against BVDV-1h. Regarding the cross neutralizing (heterologous) antibodies, the lowest titer (1:20) was produced by the BVDV-1f antiserum against the BVDV-1a and BVDV1-b viruses. The highest cross neutralizing titer (1:2580) achieved by the BVDV-1h antiserum was against the BVDV-1b strain. The cross neutralization results indicated particular serological differences between the recently described subgroup (BVDV-1l) and BVDV-1a/-1b, which are widely used in commercial vaccines. Considering the cross neutralization titers, it is concluded that selected BVDV-1l and BVDV-1h strains can be used for the development of diagnostic and control tools.

  13. Genetic diversity and frequency of bovine viral diarrhea virus (BVDV) detected in cattle in Turkey.

    Science.gov (United States)

    Yilmaz, Huseyin; Altan, Eda; Ridpath, Julia; Turan, Nuri

    2012-09-01

    The aim of this study was to investigate the frequency and diversity of bovine viral diarrhea viruses (BVDV) infecting cattle in Turkey. A total of 1124 bovine blood samples from 19 farms in 4 different Turkish regions were tested by antigen capture ELISA (ACE). BVDV antigen was found in 26 samples from 13 farms. Only 20 of the 26 initial test positive cattle were available for retesting. Of these, 6 of 20 tested positive for BVDV, by ACE and real-time RT-PCR, one month after initial testing. Phylogenetic analysis, based on comparison of the E2 or the 5'UTR coding regions, from 19 of the 26 initial positive samples, indicated that 17 belonged to the BVDV-1 genotype and 2 to the BVDV-2 genotype. Comparison of 5'UTR sequences segregated 8 BVDV-1 strains (strains 5, 6, 10, 11, 12, 13, 17, and 19) to the BVDV1f, 1 strain (strain 8) to the BVDV1i and 1 strain (strain 14) to the BVDV1d subgenotypes. One strain (strain 4) did not group with other subgenotypes but was closer to the BVDV1f. The remaining 6 BVDV-1 strains (strains 1, 2, 3, 7, 9, and 18) segregated to a novel subgenotype. The E2 sequence comparison results were similar, with the exception that strain 5 grouped with the novel subgenotype rather than BVDV1f subgenotype. It appears that among the diverse BVDV strains in circulation there may be a subgenotype that is unique to Turkey. This should be considered in the design of diagnostics and vaccines to be used in Turkey.

  14. Improved BVDV1b challenge model for evaluating efficacy of protection against clinical signs following acute infection

    Science.gov (United States)

    Introduction: Efficacy of bovine viral diarrhea virus (BVDV) vaccines in preventing acute infections is evaluated based on reduction of clinical disease. While high virulence BVDV2 strains are used in U.S. vaccine efficacy studies, the BVDV1 strain, NY-1, made available by the USDA as a challenge ...

  15. Pathogenetic differences after experimental infection of calves with Korean non-cytopathic BVDV-1 and BVDV-2 isolates.

    Science.gov (United States)

    Seong, Giyong; Oem, Jae-Ku; Choi, Kyoung-Seong

    2013-11-15

    The purpose of this study was to compare clinical and virological differences between non-cytopathic (ncp) bovine viral diarrhea virus (BVDV)-1 and ncp BVDV-2 isolated from Korean field cases. Each five naïve calves were experimentally infected with Korean ncp BVDV-1 or BVDV-2 isolates. Two additional age-matched animals were used as uninfected controls. Leukocyte, lymphocyte, and platelet counts declined in all infected calves, but were significantly lower and remained decreased longer in calves infected with ncp BVDV-2 isolate. The number of monocytes was greater in calves infected with ncp BVDV-2. Flow cytometric assay showed that lymphocyte apoptosis occurred with an increase of annexin-V positive cells in all infected calves by day 6. Tumor necrosis factor alpha (TNF-α) concentration in all infected calves was lower than in control calves. In ncp BVDV-1 infected calves, interferon gamma (IFN-γ) levels in the serum were increased by day 6 compared to calves infected with ncp BVDV-2. These results demonstrated that the Korean ncp BVDV-2 isolate shows a reduced IFN-γ production, indicating prevention of the antiviral activity, and therefore promotes the development of pathological effects.

  16. Proteção fetal frente a desafio com o vírus da Diarréia Viral Bovina (BVDV em ovelhas imunizadas com duas amostras de vírus modificadas experimentalmente Fetal protection against challenge with bovine viral diarrhea virus (BVDV in pregnant ewes immunized with two strains experimentally attenuated

    Directory of Open Access Journals (Sweden)

    Mário C.S. Brum

    2002-04-01

    virus (BVDV submitted to multiple passages in tissue culture associated with ultraviolet irradiation were evaluated as vaccine virus candidates. The attenuation of the modified viruses was assessed in calves and in pregnant ewes. Intramuscular inoculation of the viruses in four seronegative calves produced only a mild and transient rise in body temperature, followed by the production of high titers of neutralizing antibodies. The viruses were not detected in nasal secretions or in the blood following inoculation. However, intramuscular inoculation of these viruses in four pregnant ewes resulted in transplacental transmission and infection of all fetuses. To assess fetal protection conferred by immunization, pregnant ewes immunized twice with the modified viruses were subsequently challenged by intranasal inoculation of BVDV-1 (SV-126.8, n=6 or BVDV-2 (SV-260, n=5. At the day of challenge (134 days after the second immunization, all ewes had high titers of neutralizing antibodies (256 to >4096 to the vaccine viruses and variable titers (8 to >4096 to Brazilian BVDV-1 and BVDV-2 field isolates. Fifteen days after challenge, the ewes were euthanized and fetal tissues were examined for infectivity. All fetuses from non-vaccinated, challenged ewes (n=4 were infected. In contrast, none of the fetuses from the immunized dams (n=11 were positive for virus, indicating that the immunological response induced by immunization with the vaccine candidate viruses was capable of preventing fetal infection. These results indicate that it is possible to achieve fetal protection to BVDV by induction of a strong immunological response using modified live vaccines.

  17. Immunology of BVDV vaccines

    Science.gov (United States)

    The use of vaccination to control bovine viral diarrhea virus (BVDV) infections presents exceptional challenges due to the nature of the virus, the unique interaction of the virus with the immune system, and its ability to establish persistent infections. The lack of proof reading function during th...

  18. 牛病毒性腹泻BVDV2/JZ05-1基础毒株的安全性和免疫原性研究%Safety and Immunogenicity Study of Bovine Viral Diarrhea Virus 2 Strain JZ05-1

    Institute of Scientific and Technical Information of China (English)

    李海涛; 苗利光; 刘艳环; 朱言柱; 王松; 王文昊; 安亚雄

    2012-01-01

    本试验用已分离到的牛病毒性腹泻病毒BVDV2/JZ05-1基础毒株对犊牛免疫的安全性和免疫原性进行了研究.通过对基础毒种单剂量、超剂量、单剂量重复安全试验和免疫原性试验研究证实,BVDV2/JZ05-1对犊牛免疫是安全的,对犊牛感染BVDV有很好的免疫保护效果.%The bovine viral diarrhea virus 2 strain JZ05-1 (BVDV2/JZ05-1) was isolated in this experiment. Single dose, overdose and single dose reduplication safety experiment and immunogenicity experiment were carried out in this experiment. When the calves were immunized with BVDV2/JZ05-1, the safety and immunogenicity of BVDV2/JZ05-1 were examined. The results suggested that the immunization of BVDV2/JZ05 is safe for calves, and it can well protect calves from the BVDV.

  19. Detection and characterization of viruses as field and vaccine strains in feedlot cattle with bovine respiratory disease.

    Science.gov (United States)

    Fulton, R W; d'Offay, J M; Landis, C; Miles, D G; Smith, R A; Saliki, J T; Ridpath, J F; Confer, A W; Neill, J D; Eberle, R; Clement, T J; Chase, C C L; Burge, L J; Payton, M E

    2016-06-24

    This study investigated viruses in bovine respiratory disease (BRD) cases in feedlots, including bovine herpesvirus-1 (BoHV-1), bovine viral diarrhea virus (BVDV), bovine respiratory syncytial virus (BRSV), bovine coronaviruses (BoCV) and parainfluenza-3 virus (PI3V). Nasal swabs were collected from 114 cattle on initial BRD treatment. Processing included modified live virus (MLV) vaccination. Seven BRD necropsy cases were included for 121 total cases. Mean number of days on feed before first sample was 14.9 days. Swabs and tissue homogenates were tested by gel based PCR (G-PCR), quantitative-PCR (qPCR) and quantitative real time reverse transcriptase PCR (qRT-PCR) and viral culture. There were 87/114 (76.3%) swabs positive for at least one virus by at least one test. All necropsy cases were positive for at least one virus. Of 121 cases, positives included 18/121 (14.9%) BoHV-1; 19/121 (15.7%) BVDV; 76/121 (62.8%) BoCV; 11/121 (9.1%) BRSV; and 10/121 (8.3%) PI3V. For nasal swabs, G-PCR (5 viruses) detected 44/114 (38.6%); q-PCR and qRT-PCR (4 viruses) detected 81/114 (71.6%); and virus isolation detected 40/114 (35.1%). Most were positive for only one or two tests, but not all three tests. Necropsy cases had positives: 5/7 G-PCR, 5/7 q-PCR and qRT-PCR, and all were positive by cell culture. In some cases, G-PCR and both real time PCR were negative for BoHV-1, BVDV, and PI3V in samples positive by culture. PCR did not differentiate field from vaccines strains of BoHV-1, BVDV, and PI3V. However based on sequencing and analysis, field and vaccine strains of culture positive BoHV-1, BoCV, BVDV, and PI3V, 11/18 (61.1%) of BoHV-1 isolates, 6/17 (35.3%) BVDV isolates, and 1/10 (10.0%) PI3V identified as vaccine. BRSV was only identified by PCR testing. Interpretation of laboratory tests is appropriate as molecular based tests and virus isolation cannot separate field from vaccine strains. Additional testing using sequencing appears appropriate for identifying vaccine

  20. A infecção pelo vírus da diarréia viral bovina (BVDV no Brasil: histórico, situação atual e perspectivas Bovine viral diarrhea virus (BVDV infection in Brazil: history, current situation and perspectives

    Directory of Open Access Journals (Sweden)

    Eduardo F. Flores

    2005-09-01

    BVDV-1 e 2. O conhecimento sobre a infecção pelo BVDV no Brasil tem aumentado consideravelmente nos últimos anos, à medida em que cresce o número de laboratórios envolvidos em diagnóstico e pesquisa sobre esse vírus. Diagnóstico sorológico, virológico ou molecular; estudos sobre epidemiologia sorológica e molecular, patogenia e produção de reagentes para diagnósitco têm contribuído para o aumento no conhecimento sobre a infecção pelo BVDV no país.Bovine viral diarrhea virus (BVDV is one of the most important pathogens of cattle worldwide. BVDV infection and associated diseases have been reported in Brazil since the late 1960ties. Several serological, virological, clinical and pathological reports demonstrate the widespread distribution of BVDV infection among Brazilian cattle. In addition to variable levels of positive serology in beef and dairy cattle, BVDV antibodies have been occasionally detected in swine, wild boars, goats, cervids and water buffaloes. BVDV infection has been diagnosed in aborted fetuses, buffy coats of persistently infected (PI animals, clinical specimens from animals suffering from different clinical syndromes, semen of bulls of artificial insemination (AI centers, in healthy fetuses and in commercial fetal bovine serum and/or cultured cells. About 50 isolates have been genetically and/or antigenically characterized up to date, whilst roughly an equivalent number of isolates awaits characterization. Most of the characterized isolates belong to BVDV-1 genotype, non-cytopathic (NCP biotype, yet some BVDV-2 (and some CP BVDV have been identified as well. Brazilian BVDV isolates display a high antigenic variability and are markedly different from North American vaccine strains. A few inactivated, polyvalent vaccines are currently licensed in the country, yet vaccination is still incipient in many regions: only about 2.5 million doses were marketed in 2003. The low serological cross-reactivity between vaccine strains and field

  1. Expression of Bovine Viral Diarrhea Virus Envelope Glycoprotein E2 in Yeast Pichia pastoris and its Application to an ELISA for Detection of BVDV Neutralizing Antibodies in Cattle.

    Science.gov (United States)

    Behera, Sthita Pragnya; Mishra, Niranjan; Nema, Ram Kumar; Pandey, Pooja Dubey; Kalaiyarasu, Semmannan; Rajukumar, Katherukamem; Prakash, Anil

    2015-01-01

    The aim of this article is to express envelope glycoprotein E2 of bovine viral diarrhea virus (BVDV) in yeast Pichia pastoris and its utility as a diagnostic antigen in ELISA. The BVDV E2 gene was cloned into the pPICZαA vector followed by integration into the Pichia pastoris strain X-33 genome for methanol-induced expression. SDS-PAGE and Western blot results showed that the recombinant BVDV E2 protein (72 kDa) was expressed and secreted into the medium at a concentration of 40 mg/L of culture under optimized conditions. An indirect ELISA was then developed by using the yeast-expressed E2 protein. Preliminary testing of 300 field cattle serum samples showed that the E2 ELISA showed a sensitivity of 91.07% and a specificity of 92.02% compared to the reference virus neutralization test. The concordance between the E2 ELISA and VNT was 91.67%. This study demonstrates feasibility of BVDV E2 protein expression in yeast Pichia pastoris for the first time and its efficacy as an antigen in ELISA for detecting BVDV neutralizing antibodies in cattle.

  2. Piezoelectric field in strained GaAs.

    Energy Technology Data Exchange (ETDEWEB)

    Chow, Weng Wah; Wieczorek, Sebastian Maciej

    2005-11-01

    This report describes an investigation of the piezoelectric field in strained bulk GaAs. The bound charge distribution is calculated and suitable electrode configurations are proposed for (1) uniaxial and (2) biaxial strain. The screening of the piezoelectric field is studied for different impurity concentrations and sample lengths. Electric current due to the piezoelectric field is calculated for the cases of (1) fixed strain and (2) strain varying in time at a constant rate.

  3. Proteção fetal frente a desafio com o vírus da Diarréia Viral Bovina (BVDV) em ovelhas imunizadas com duas amostras de vírus modificadas experimentalmente Fetal protection against challenge with bovine viral diarrhea virus (BVDV) in pregnant ewes immunized with two strains experimentally attenuated

    OpenAIRE

    Mário C. S. Brum; Rudi Weiblen; Eduardo F. Flores; Edviges M. Pituco; Fernando L. Tobias; Winkelmann, Evandro R.

    2002-01-01

    Duas amostras do vírus da Diarréia Viral Bovina (BVDV) submetidas a múltiplas passagens em cultivo celular e exposição à radiação ultravioleta (UV) a cada passagem foram avaliadas como candidatos a vírus vacinais. As amostras foram testadas quanto à sua atenuação para bezerros e fetos ovinos, reatividade antigênica contra isolados de campo, e capacidade de induzir proteção fetal em ovelhas prenhes. Inoculação intramuscular (IM) dos vírus modificados em quatro bezerros produziu apenas uma elev...

  4. Persistent BVDV infection in mousedeer infects calves - Do we know the reservoirs for BVDV?

    DEFF Research Database (Denmark)

    Uttenthal, Åse; Grøndahl, M.J.; Houe, Hans;

    2005-01-01

    Bovine virus diarrhoea virus (BVDV)-1f was isolated from a Lesser Malayan Mousedeer in Copenhagen Zoo during a routine screening. Analysis of animals related to the Copenhagen mousedeer revealed that its mother and all siblings were virus positive, a pattern also seen for persistently infected (P......) cattle. BVDV could be transmitted from the PI mousedeer to a calf after indirect contact. The host spectrum for BVDV seems to be even wider than expected; the implications for BVDV control are discussed. (c) 2005 Elsevier B.V. All rights reserved....

  5. Complete Genome Sequence of a Bovine Viral Diarrhea Virus Strain Isolated in Southern China

    OpenAIRE

    Xie, Zhixun; Fan, Qing; Xie, Zhiqin; Liu, Jiabo; Pang, Yaoshan; Deng, Xianwen; Xie, Liji; Luo, Sisi; Khan, M. I.

    2014-01-01

    We report here the full-length RNA genomic sequence of the bovine viral diarrhea virus (BVDV) strain GX4, isolated from a cow in southern China. Studies indicate that BVDV GX4 belongs to the BVDV-1b subtype. This report will help in understanding the epidemiology and molecular characteristics of BVDV in southern China cattle.

  6. Dark field electron holography for strain measurement

    Energy Technology Data Exchange (ETDEWEB)

    Beche, A., E-mail: armand.beche@fei.com [CEA-Grenoble, INAC/SP2M/LEMMA, F-38054 Grenoble (France); Rouviere, J.L. [CEA-Grenoble, INAC/SP2M/LEMMA, F-38054 Grenoble (France); Barnes, J.P.; Cooper, D. [CEA-LETI, Minatec Campus, F-38054 Grenoble (France)

    2011-02-15

    Dark field electron holography is a new TEM-based technique for measuring strain with nanometer scale resolution. Here we present the procedure to align a transmission electron microscope and obtain dark field holograms as well as the theoretical background necessary to reconstruct strain maps from holograms. A series of experimental parameters such as biprism voltage, sample thickness, exposure time, tilt angle and choice of diffracted beam are then investigated on a silicon-germanium layer epitaxially embedded in a silicon matrix in order to obtain optimal dark field holograms over a large field of view with good spatial resolution and strain sensitivity. -- Research Highlights: {yields} Step by step explanation of the dark field electron holography technique. {yields} Presentation of the theoretical equations to obtain quantitative strain map. {yields} Description of experimental parameters influencing dark field holography results. {yields} Quantitative strain measurement on a SiGe layer embedded in a silicon matrix.

  7. Revisiting the gauge fields of strained graphene

    OpenAIRE

    Iorio, Alfredo; Pais, Pablo(Centro de Estudios Científicos (CECS), Casilla, 1469 , Valdivia, Chile)

    2015-01-01

    We show that, when graphene is only subject to strain, the spin connection gauge field that arises plays no measurable role, but when intrinsic curvature is present and strain is small, spin connection dictates most the physics. We do so by showing that the Weyl field associated with strain is a pure gauge field and no constraint on the $(2+1)$-dimensional spacetime appears. On the other hand, for constant intrinsic curvature that also gives a pure-gauge Weyl field, we find a classical manife...

  8. Risk assessment of transmission of bovine viral diarrhea virus (BVDV) in abattoir-derived in vitro produced embryos.

    Science.gov (United States)

    Perry, G H

    2007-07-01

    Bovine virus diarrhea virus (BVDV) is a pathogen of the bovine reproductive system causing reduced conception rates, abortions and persistently infected calves. Most if not all strains of BVDV are transmissible by natural mating and AI. For international trade, it is recommended that in vitro fertilized embryos be washed according to the IETS Manual. However, BVDV may not be entirely washed out, resulting in possible transmission risks to recipients. Donor cows, donor bulls and biological agents are all possible sources of contamination. The process for producing in vitro produced (IVP) embryos is complex and non-standard, and some procedures can contribute to spread of BVDV to uninfected embryos. The structure of the zone pellucida (ZP) of IVP embryos permits adherence of BVDV to the ZP. To estimate the risk of producing infected recipients and persistently infected calves from abattoir-derived IVP embryos, a quantitative risk assessment model using Microsoft Excel and Palisade @Risk was developed. Assumptions simplified some of the complexities of the IVP process. Uncertainties due to incomplete or variable data were addressed by incorporating probability distributions in the model. Model variables included: disease prevalence; the number of donor cows slaughtered for ovaries; the number of oocytes collected, selected and cultured; the BVDV status of ovaries, semen, biological compounds and its behavior in the IVP embryo process. The model used the Monte Carlo method to simulate the IVP process. When co-culture cells derived from donor cows of unknown health status were used for in vitro culture (IVC), the probability of a recipient cow at risk of infection to BVDV per oocyte selected for IVP processing averaged 0.0006. However, when co-culture free from BVDV was used, the probability was 1.2 x 10(-5). Thus, for safe international trade in bovine IVP embryos (i.e. negligible risks of transmission of BVDV), co-culture cells, if used during IVC for producing IVP

  9. 3D Morphing Using Strain Field Interpolation

    Institute of Scientific and Technical Information of China (English)

    Han-Bing Yan; Shi-Min Hu; Ralph R Martin

    2007-01-01

    In this paper, we present a new technique based on strain fields to carry out 3D shape morphing for applicationsin computer graphics and related areas.Strain is an important geometric quantity used in mechanics to describe the deformation of objects.We apply it in a novel way to analyze and control deformation in morphing.Using position vector fields, the strain field relating source and target shapes can be obtained.By interpolating this strain field between zero and a final desired value we can obtain the position field for intermediate shapes.This method ensures that the 3D morphing process is smooth.Locally, volumes suffer minimal distortion, and no shape jittering or wobbling happens: other methods do not necessarily have these desirable properties.We also show how to control the method so that changes of shape (in particular, size changes) vary linearly with time.

  10. Pseudomagnetic fields and triaxial strain in graphene

    DEFF Research Database (Denmark)

    Settnes, Mikkel; Power, Stephen; Jauho, Antti-Pekka

    2016-01-01

    -binding calculations of single pseudomagnetic dots in extended graphene sheets confirm these predictions, and are also used to study the effect of rotating the strain direction with respect to the underlying graphene lattice, and varying the size of the pseudomagnetic dot.......Pseudomagnetic fields, which can result from nonuniform strain distributions, have received much attention in graphene systems due to the possibility of mimicking real magnetic fields with magnitudes of greater than 100 T. We examine systems with such strains confined to finite regions...

  11. A novel real-time RT-PCR with TaqMan-MGB probes and its application in detecting BVDV infections in dairy farms

    Institute of Scientific and Technical Information of China (English)

    ZHANG Yong-qiang; WANG Zhi-liang; LIU Hai-sheng; WU Xiao-dong; WANG Xiao-zhen; LI Jin-ming; ZHAO Yong-gang; L Yan; REN Wei-jie; GE Sheng-qiang

    2015-01-01

    A real-time RT-PCR assay using TaqMan-MGB probes was developed to detect and type the bovine viral diarrhea virus (BVDV) in cattle. Universal primers and TaqMan-MGB probes were designed from the 5´-untranslated region of known pestiviral sequences. Prior to optimizing the assay, cRNAs were transcribed in vitro from the BVDV 1 and BVDV 2 RT-PCR products to make standard curves. The detection limit of the assay was 1.72×102 copies for BVDV 1 and 2.14×102 copies for BVDV 2. The speciifcity of the assay evaluated on several BVDV strains including bovine herpesvirus 1 (BHV 1), foot and mouth disease virus (FMDV) and several classical swine fever virus (CSFV) strains showed speciifc detection of the positive virus over 40 cycles. The assay was highly reproducible with the coefifcient of variance ranging from 1.04 to 1.33%for BVDV 1 and from 0.83 to 1.48%for BVDV 2, respectively. Using this method, we tested a total of 2 327 cattle from three dairy farms for the presence of BVDV persistently infected (PI) animals. In this assay, each RT-PCR template contained a mixture of ten samples from different animals. The occurrence rate of PI cattle in three farms ranging from 0.9 to 2.54%could represent partly the PI rates in cattle farm in China. In conclusion, using our real-time PCR assay, we could effectively detect and type BVDV and identify PI cattle in a rapid and cost-effective manner.

  12. BVDV: Detection, Risk Management and Control

    Science.gov (United States)

    The terms bovine viral diarrhea (BVD) and bovine viral diarrhea viruses (BVDV) are difficult to define in simple straightforward statements because both are umbrella terms covering a wide range of observations and entities. While diarrhea is in the name, BVD, it is used in reference to a number of ...

  13. Revisiting the gauge fields of strained graphene

    Science.gov (United States)

    Iorio, Alfredo; Pais, Pablo

    2015-12-01

    We show that when graphene is only subject to strain, the spin connection gauge field that arises plays no measurable role, but when intrinsic curvature is present and strain is small, spin connection dictates most of the physics. We do so by showing that the Weyl field associated with strain is a pure gauge field and no constraint on the (2 +1 )-dimensional spacetime appears. On the other hand, for constant intrinsic curvature that also gives a pure gauge Weyl field, we find a classical manifestation of a quantum Weyl anomaly, descending from a constrained spacetime. We are in the position to do this because we find the equations that the conformal factor in (2 +1 ) dimensions has to satisfy, which is a nontrivial generalization to (2 +1 ) dimensions of the classic Liouville equation of the differential geometry of surfaces. Finally, we comment on the peculiarities of the only gauge field that can describe strain, the well-known pseudogauge field A1˜u11-u22 and A2˜u12 , and conclude by offering some scenarios in fundamental physics that this peculiar field could help to realize.

  14. MAGNITUDE, DURAÇÃO E ESPECIFICIDADE DA RESPOSTA SOROLÓGICA EM BOVINOS VACINADOS CONTRA O VÍRUS DA DIARRÉIA VIRAL BOVINA (BVDV MAGNITUDE DURATION AND SPECIFICITY OF THE SEROLOGICAL RESPONSE IN CATTLE VACCINATED AGAINST BOVINE VIRAL DIARRHEA VIRUS (BVDV

    Directory of Open Access Journals (Sweden)

    Fernanda Silveira Flores Vogel

    2002-02-01

    frente à grande diversidade antigênica das amostras de BVDV.The serological response induced by three inactivated commercial vaccines against bovine viral diarrhea virus (BVDV was evaluated in calves immunized three times (days 0, 30 and 180 and examined at different intervals after vaccination. Thirty days after the second vaccination, 74.5% (70/94 of the calves had developed neutralizing antibodies titers against BVDV-1 and 52.1% (49/94 against BVDV-2. The geometric mean titers (GMT and the number of animals with antibodies to BVDV-1 were 109.3(32/36; 54.6(22/28 and 25.5(16/30 for vaccines A, B e C, respectively and 19(27/36, 42.3(12/28 and 18.4(10/30 to BVDV-2. The antibody titers decreased by day 180, when 31.9%(30/94 of the calves showed no neutralizing activity against BVDV-1 and 63.8%(60/94 to BVDV-2. At that time, the GMTs and the number of animals seropositive to BVDV-1 were 28.3 (30/36, 28.3(20/28 and 16.1(14/30; and to BVDV-2 were 16.8(18/36, 21.6(10/28 and 28.3(6/30 for vaccines A, B and C, respectively. After the third dosis (day 180, the antibody titers to BVDV-1 increased significantly in all groups whereas a significant increase in BVDV-2 titers was observed only for vaccine A. At day 210, GMTs and the number of positive animals to BVDV-1 were 104.8(23/24, 50.3(24/26 and 43.7(24/28 and to BVDV-2 were 33.4(23/24, 23.3(22/26 and 15.7(22/28 for vaccines A, B and C. The neutralizing activity against BVDV-1 was higher than to BVDV-2 in all groups at day 210. Sera from five seropositive animals of each vaccine group were tested against four Brazilian BVDV-1 and two BVDV-2 isolates. In addition to the low and moderate titers, the cross-neutralization assays revealed a highly variable neutralizing activity against the Brazilian field isolates. These results demonstrated that the vaccination did not induce an adequate serological response in most animals, mainly due to the high antigenic variability of BVDV.

  15. Epidemiology and genetic characterization of BVDV, BHV-1, BHV-4, BHV-5 and Brucella spp. infections in cattle in Turkey.

    Science.gov (United States)

    Aslan, Muhammet Eren; Azkur, Ahmet Kursat; Gazyagci, Serkal

    2015-11-01

    The aim of the study was to determine the epidemiological data of bovine viral diarrhea virus (BVDV), bovine herpesvirus-1 (BHV-1), bovine herpesvirus-4 (BHV-4), bovine herpesvirus-5 (BHV-5) and Brucella-associated cattle that were previously reported to have abortion and infertility problems in Ankara, Corum, Kirikkale and Yozgat provinces, Turkey. Whole blood and sera samples were obtained from 656 cattle, and antibodies against Brucella spp. were detected in 45 (6.86%) and 41 (6.25%) animals by Rose Bengal plate and serum tube agglutination tests, respectively. The seropositivity rates against BVDV, BHV-1 and BHV-4 were 70.89%, 41.3% and 28.78%, respectively. RT-PCR and PCR were performed to detect RNA and DNA viruses in blood samples, respectively. The BVDV 5'-untranslated region and BHV-1 gB gene detected in this study were phylogenetically analyzed. The BVDV strains analyzed in this study were closely related to those previously reported from Turkey. The nucleotide sequence from the BHV-1 strain detected in this study is the first nucleotide sequence of BHV-1 circulating in this area of Turkey deposited in the GenBank. The presence of Brucella spp. and prevalence of BHV-1, BHV-4 and BVDV in cattle should be further investigated throughout these regions.

  16. Strain sensors for high field pulse magnets

    Energy Technology Data Exchange (ETDEWEB)

    Martinez, Christian [Los Alamos National Laboratory; Zheng, Yan [Los Alamos National Laboratory; Easton, Daniel [Los Alamos National Laboratory; Farinholt, Kevin M [Los Alamos National Laboratory; Park, Gyuhae [Los Alamos National Laboratory

    2009-01-01

    In this paper we present an investigation into several strain sensing technologies that are being considered to monitor mechanical deformation within the steel reinforcement shells used in high field pulsed magnets. Such systems generally operate at cryogenic temperatures to mitigate heating issues that are inherent in the coils of nondestructive, high field pulsed magnets. The objective of this preliminary study is to characterize the performance of various strain sensing technologies at liquid nitrogen temperatures (-196 C). Four sensor types are considered in this investigation: fiber Bragg gratings (FBG), resistive foil strain gauges (RFSG), piezoelectric polymers (PVDF), and piezoceramics (PZT). Three operational conditions are considered for each sensor: bond integrity, sensitivity as a function of temperature, and thermal cycling effects. Several experiments were conducted as part of this study, investigating adhesion with various substrate materials (stainless steel, aluminum, and carbon fiber), sensitivity to static (FBG and RFSG) and dynamic (RFSG, PVDF and PZT) load conditions, and sensor diagnostics using PZT sensors. This work has been conducted in collaboration with the National High Magnetic Field Laboratory (NHMFL), and the results of this study will be used to identify the set of sensing technologies that would be best suited for integration within high field pulsed magnets at the NHMFL facility.

  17. Revisiting the gauge fields of strained graphene

    CERN Document Server

    Iorio, Alfredo

    2015-01-01

    We join the on-going debate on the nature of the gauge fields arising when straining graphene, hopefully adding clarity to the debate, especially in view of the use of graphene as a table-top indirect laboratory for high energy physics. We identify two types of gauge fields: the first one arising from a trivial spin-connection of zero Riemann tensor, that gives a pure-gauge Weyl field; the second one originating from peculiar structure of the graphene honeycomb, whose non-triviality is encoded in a special rank-three tensor. The former cannot give a nonzero "pseudo-magnetic field", but the relativistic approach behind it explains non-isotropic, space-dependent Fermi velocity. The latter has, in general, nonzero associated field-strength, and gives an example of a low-energy (continuum limit) relic of a high-energy (lattice) structure, a feature that makes it interesting for explorations of fundamental physics scenarios with similar behaviors. We conclude by briefly pointing to some of those scenarios.

  18. Predicted costs and benefits of eradicating BVDV from Ireland

    Directory of Open Access Journals (Sweden)

    Stott Alistair W

    2012-07-01

    Full Text Available Abstract Bovine viral diarrhoea virus (BVDV causes an economically important endemic disease (BVD of cattle in Ireland and worldwide. Systematic eradication by detection and removal of infectious (BVDV carrier cattle has been successful in several regions. We therefore assessed the benefits (disease losses avoided and costs (testing and culling regime of a potential eradication programme in Ireland. Published bio-economic models of BVDV spread in beef suckler herds and dairy herds were adapted to estimate potential benefits of eradication in Ireland. A simple model of BVDV spread in beef finisher herds was devised to estimate the benefits of eradication in this sector. A six year eradication programme consisting of 5 inter-related virological and serological testing programmes is outlined and costed. We found that the annualised benefits of BVDV eradication in Ireland exceeded the costs by a factor of 5 in the beef suckler sector and a factor of 14 in the dairy sector. Corresponding payback periods were 1.2 and 0.5 years respectively. These results highlight the significant economic impact of BVDV on the Irish cattle industry and suggest a clear economic benefit to eradication using the proposed approach. This type of cost-benefit analysis is considered an essential prerequisite prior to undertaking an eradication campaign of this magnitude.

  19. Antigenic variability in bovine viral diarrhea virus (BVDV) isolates from alpaca (Vicugna pacos), llama (Lama glama) and bovines in Chile.

    Science.gov (United States)

    Aguirre, I M; Quezada, M P; Celedón, M O

    2014-01-31

    Llamas and alpacas are domesticated South American camelids (SACs) important to ancestral population in the Altiplano region, and to different communities where they have been introduced worldwide. These ungulates have shown to be susceptible to several livestock viral pathogens such as members of the Pestivirus genus and mainly to bovine viral diarrhea virus (BVDV). Seventeen Chilean BVDV isolates were analyzed by serum cross neutralization with samples obtained from five llama, six alpacas, three bovines, plus three reference strains belonging to different subgroups and genotypes. The objective was to describe antigenic differences and similarities among them. Antigenic comparison showed significant differences between different subgroups. Consequently, antigenic similarities were observed among isolates belonging to the same subgroup and also between isolates from different animal species belonging the same subgroup. Among the analyzed samples, one pair of 1b subgroup isolates showed significant antigenic differences. On the other hand, one pair of isolates from different subgroups (1b and 1j) shared antigenic similarities indicating antigenic relatedness. This study shows for the first time the presence of antigenic differences within BVDV 1b subgroup and antigenic similarities within 1j subgroup isolates, demonstrating that genetic differences within BVDV subgroups do not necessary corresponds to differences on antigenicity.

  20. Imaging 3D strain field monitoring during hydraulic fracturing processes

    Science.gov (United States)

    Chen, Rongzhang; Zaghloul, Mohamed A. S.; Yan, Aidong; Li, Shuo; Lu, Guanyi; Ames, Brandon C.; Zolfaghari, Navid; Bunger, Andrew P.; Li, Ming-Jun; Chen, Kevin P.

    2016-05-01

    In this paper, we present a distributed fiber optic sensing scheme to study 3D strain fields inside concrete cubes during hydraulic fracturing process. Optical fibers embedded in concrete were used to monitor 3D strain field build-up with external hydraulic pressures. High spatial resolution strain fields were interrogated by the in-fiber Rayleigh backscattering with 1-cm spatial resolution using optical frequency domain reflectometry. The fiber optics sensor scheme presented in this paper provides scientists and engineers a unique laboratory tool to understand the hydraulic fracturing processes in various rock formations and its impacts to environments.

  1. Genotypic Diversity of Haemophilus parasuis Field Strains

    OpenAIRE

    Olvera, A.; Calsamiglia, M.; Aragon, V. (V.)

    2006-01-01

    Haemophilus parasuis is the cause of Glässer's disease and other clinical disorders in pigs. It can also be isolated from the upper respiratory tracts of healthy pigs, and isolates can have significant differences in virulence. In this work, a partial sequence from the 60-kDa heat shock protein (Hsp60) gene was assessed as an epidemiological marker. We analyzed partial sequences of hsp60 and 16S rRNA genes from 103 strains of H. parasuis and other related species to obtain a better classifica...

  2. Principles for eradication of bovine viral diarrhoea virus (BVDV) infections in cattle populations.

    Science.gov (United States)

    Lindberg, A L; Alenius, S

    1999-01-01

    Systematic eradication of BVDV without vaccination started in Scandinavia in 1993. In principle, the schemes include; (1) identification of non-infected and infected herds using different combinations of serological herd tests such as bulk milk tests and spot tests (sample of animals in a certain age), (2) monitoring/certification of non-infected herds by repeated sampling, applying one of the above-mentioned methods and (3) virus clearance in infected herds aimed at removing persistently infected (PI) animals in a cost- and time-efficient manner. In the virus clearance protocol described, an initial test is performed on all animals with subsequent follow-up of calves born as well as of dams seronegative in the initial test. It is generally recommended to perform an initial antibody test on all samples. This should be done not only to screen for seronegative animals on which virus isolation should be attempted (i.e. possible PI animals), but more in order to identify non-immune animals in reproductive age, that is, the key animals in herd-level persistence of infection. In Sweden, a common finding has been self-clearance, where the infection ceases without any other intervention than controlled introduction of new animals. Other epidemiological observations concern the course of events following virus introduction. Important risk factors for spreading BVDV are discussed, where livestock trade is perceived as the most central to control. Live vaccines, imported semen and embryos constitute special hazards, since they may act as vehicles for the introduction of new BVDV strains. The importance of making farmers aware of herd biosecurity and their own responsibility for it is stressed, and in order to maintain a favourable situation after a scheme has been concluded, effort must be put into establishing such a persisting attitude in the farming community.

  3. Strain Measurement on the Toroidal Field (TF) Coil Cases

    Institute of Scientific and Technical Information of China (English)

    Chen Zhuomin; Long Feng; Wu Hao

    2005-01-01

    The stress-strain state of the structure is a matter of interest to designer. The strain measurement of superconducting magnets at cryogenic temperature is a specific technique. Based on strain measurement of TF coil case for EAST, this paper presents a measuring technique at cryogenic temperature and on intense magnetic field. The compensation methods for both temperature and magnetic field effects of the gauges, together with the measured results are involved, and the discussions of the measured results are given in the paper.

  4. BVDV vaccination in North America: risks versus benefits.

    Science.gov (United States)

    Griebel, Philip J

    2015-06-01

    The control and prevention of bovine viral diarrhea virus (BVDV) infections has provided substantial challenges. Viral genetic variation, persistent infections, and viral tropism for immune cells have complicated disease control strategies. Vaccination has, however, provided an effective tool to prevent acute systemic infections and increase reproductive efficiency through fetal protection. There has been substantial controversy about the safety and efficacy of BVDV vaccines, especially when comparing killed versus modified-live viral (MLV) vaccines. Furthermore, numerous vaccination protocols have been proposed to protect the fetus and ensure maternal antibody transfer to the calf. These issues have been further complicated by reports of immune suppression during natural infections and following vaccination. While killed BVDV vaccines provide the greatest safety, their limited immunogenicity makes multiple vaccinations necessary. In contrast, MLV BVDV vaccines induce a broader range of immune responses with a longer duration of immunity, but require strategic vaccination to minimize potential risks. Vaccination strategies for breeding females and young calves, in the face of maternal antibody, are discussed. With intranasal vaccination of young calves it is possible to avoid maternal antibody interference and induce immune memory that persists for 6-8 months. Thus, with an integrated vaccination protocol for both breeding cows and calves it is possible to maximize disease protection while minimizing vaccine risks. PMID:26050569

  5. Short communication. Genotyping and phylogenetic analysis of bovine viral diarrhea virus (BVDV isolates in Kosovo

    Directory of Open Access Journals (Sweden)

    Izedin Goga

    2014-03-01

    Full Text Available Three serum samples positive in Antigen ELISA BVDV have been tested to characterise genetic diversity of bovine viral diarrhea virus (BVDV in Kosovo. Samples were obtained in 2011 from heifers and were amplified by reverse transcription-polymerase chain reaction, sequenced and analysed by computer-assisted phylogenetic analysis. Amplified products and nucleotide sequence showed that all 3 isolates belonged to BVDV 1 genotype and 1b sub genotype. These results enrich the extant knowledge of BVDV and represent the first documented data about Kosovo BVDV isolates.

  6. Identification and epidemiology of a rare HoBi-like pestivirus strain in Bangladesh.

    Science.gov (United States)

    Haider, N; Rahman, M S; Khan, S U; Mikolon, A; Gurley, E S; Osmani, M G; Shanta, I S; Paul, S K; Macfarlane-Berry, L; Islam, A; Desmond, J; Epstein, J H; Daszak, P; Azim, T; Luby, S P; Zeidner, N; Rahman, M Z

    2014-06-01

    The genus pestivirus of the family flaviviridae consists of four recognized species: bovine viral diarrhoea virus 1 (BVDV-1), bovine viral diarrhoea virus 2 (BVDV-2), classical swine fever virus and border disease virus. A new putative pestivirus species tentatively named as either 'HoBi-like pestivirus' or BVDV-3 has recently been identified in Brazil, Italy and Thailand. Despite reports of serological evidence of BVDV in Bangladesh, the types of the virus circulating in cattle have not been identified. We conducted surveillance in cattle from May 2009 to August 2010 in three government veterinary hospitals to characterize BVDV in cattle of Bangladesh. We tested serum for BVDV using an antigen-capture ELISA. Of 638 cattle samples, 3% (16/638) tested positive for BVDV antigen. The ELISA-positive samples were selected for further molecular detection and characterization of BVDV. Molecular analysis of the partial 5' untranslated region (UTR) nucleotide sequences of BVDV-positive samples identified the rare HoBi-like pestivirus or BVDV-3 virus circulating in cattle of Bangladesh. The identification of this rare HoBi-like pestivirus or BVDV-3 strain in Bangladesh warrants further surveillance to evaluate its impact on livestock production.

  7. Strain fields adjacent to bone-implant interfaces: strain field analysis using digital image correlation techniques

    OpenAIRE

    Ribeiro, J. E.; Monteiro, J.; Lopes, H.; Vaz, M.A.P.; Guedes, R.M.

    2008-01-01

    When using conventional surface strain measurement techniques (e.g. strain gauges, dial gauges), the measurement of deformations within cancellous bone is frequently hampered by the material’s highly porous structure and poor mechanical properties. Although detailed strain maps derived from actual experimental data have the potential to resolve many questions concerning the mechanics of cancellous bone, the traditional method of producing maps through measurements with optical techniques has ...

  8. Bovine Viral Diarrhea Virus (BVDV) in White-Tailed Deer (Odocoileus virginianus).

    Science.gov (United States)

    Passler, Thomas; Ditchkoff, Stephen S; Walz, Paul H

    2016-01-01

    Bovine viral diarrhea virus (BVDV) is the prototypic member of the genus Pestivirus in the family Flaviviridae. Infections with BVDV cause substantial economic losses to the cattle industries, prompting various organized control programs in several countries. In North America, these control programs are focused on the identification and removal of persistently infected (PI) cattle, enhancement of BVDV-specific immunity through vaccination, and the implementation of biosecure farming practices. To be successful, control measures must be based on complete knowledge of the epidemiology of BVDV, including the recognition of other potential sources of the virus. BVDV does not possess strict host-specificity, and infections of over 50 species in the mammalian order Artiodactyla have been reported. Over 50 years ago, serologic surveys first suggested the susceptibility of white-tailed deer (Odocoileus virginianus), the most abundant free-ranging ruminant in North America, to BVDV. However, susceptibility of white-tailed deer to BVDV infection does not alone imply a role in the epidemiology of the virus. To be a potential wildlife reservoir, white-tailed deer must: (1) be susceptible to BVDV, (2) shed BVDV, (3) maintain BVDV in the population, and (4) have sufficient contact with cattle that allow spillback infections. Based on the current literature, this review discusses the potential of white-tailed deer to be a reservoir for BVDV. PMID:27379074

  9. Effect of Magnetic Field on L-Strain Cells

    CERN Document Server

    Ulakoglu, G; Atak, C; Rzakoulieva, A; Danilov, V I; Alikamanoglu, S

    2000-01-01

    The effects of electromagnetic and magnetic fields are currently being made useful in many fields, especially in medicine. In this research work, L-Strain cells which are a type of fibrosarcoma cells were exposed to a magnetic flow of 2-26 mT in periods of 1, 2, 3 and 4 minutes. The L-Strain cells, which were exposed to the magnetic field for these periods, were counted after 24 and 48 hours, when compared with the controls, it was observed that in groups of 1 and 4 minutes exposure a significant decrease (P < 0.05) in the number of cells occurred. The per cent of labelling index of L-Strain cells exposed to the magnetic field for 1 and 4 minutes decreased significantly also in comparison to the controls.

  10. Field performance of a genetically engineered strain of pink bollworm.

    Directory of Open Access Journals (Sweden)

    Gregory S Simmons

    Full Text Available Pest insects harm crops, livestock and human health, either directly or by acting as vectors of disease. The Sterile Insect Technique (SIT--mass-release of sterile insects to mate with, and thereby control, their wild counterparts--has been used successfully for decades to control several pest species, including pink bollworm, a lepidopteran pest of cotton. Although it has been suggested that genetic engineering of pest insects provides potential improvements, there is uncertainty regarding its impact on their field performance. Discrimination between released and wild moths caught in monitoring traps is essential for estimating wild population levels. To address concerns about the reliability of current marking methods, we developed a genetically engineered strain of pink bollworm with a heritable fluorescent marker, to improve discrimination of sterile from wild moths. Here, we report the results of field trials showing that this engineered strain performed well under field conditions. Our data show that attributes critical to SIT in the field--ability to find a mate and to initiate copulation, as well as dispersal and persistence in the release area--were comparable between the genetically engineered strain and a standard strain. To our knowledge, these represent the first open-field experiments with a genetically engineered insect. The results described here provide encouragement for the genetic control of insect pests.

  11. Prevalence of Bovine Viral Diarrhea Virus (BVDV) in Persistently Infected Cattle and BVDV Subtypes in Affected Cattle in Beef Herds in South Central U.S.

    Science.gov (United States)

    The prevalence of bovine viral diarrhea virus (BVDV) persistently infected (PI) cattle in beef breeding herds was determined in 30 herds with 4530 calves. The samples collected by ear notches were tested for BVDV antigen using immunohistochemistry (IHC) and antigen capture ELISA (ACE). Animals wit...

  12. The measurement of the modal strain fields using digital shearography

    Science.gov (United States)

    Lopes, H.; Ribeiro, J. E.; Vaz, M.; Gomes, J. M.

    2010-06-01

    This work presents a Michelson shearography interferometer configuration associated with stroboscopic double illumination technique for the measurement of modal rotation fields and their strain fields on a clamped circular aluminium plate. The speckle pattern is frozen by the synchronization between the LASER illumination and the modal vibration of the object. The quantitative evaluation is performed for each digital shearogram using a time modulation technique. The setup of double illumination LASER with out-of-plane opposite sensitivity allows the two phase maps measurement of the modal spatial gradient. The modal rotation and strain fields are extracted by the combination of this two digital phase maps. Image processing techniques are applied on the phase maps to obtain full-field measurements using a dedicated post-processing algorithm. Finally, is presented a comparison between the experimental measurement and the numerical solution.

  13. Enhanced response from field-annealed magnetoelastic strain sensor

    Science.gov (United States)

    Dalponte, Alessandro; Bastos, Eduardo S.; Missell, Frank P.

    2016-08-01

    Magnetoelastic materials permit the development of remote-query strain sensors for use in situations of difficult access. In this work, we examined materials for a remote-query strain sensor based on the ΔE effect. An applied stress modifies the magnetic field produced by a transducer glued to the sample and thereby changes the resonant frequency of a vibrating amorphous ribbon. We considered several amorphous alloys for both the vibrating ribbon and the transducer. To eliminate the casting stress and improve the anisotropy, ribbons were annealed in a transverse magnetic field. This resulted in a dramatic improvement in the sensor performance when sensors were biased above the anisotropy field. For example, a Metglas 2826MB3 ribbon with resonant frequency of 62 kHz showed frequency shifts of up to 5 kHz for a deformation of 0.03%. These results are in good agreement with models for the ΔE effect.

  14. Transcriptomic analysis of responses to cytopathic bovine viral diarrhea virus-1 (BVDV-1) infection in MDBK cells.

    Science.gov (United States)

    Villalba, Melina; Fredericksen, Fernanda; Otth, Carola; Olavarría, Víctor

    2016-03-01

    The bovine viral diarrhea virus (BVDV) is responsible for significant economic losses in the dairy and cattle industry; however, little is known about the protective and pathological responses of hosts to infection. The present study determined the principal molecular markers implicated in viral infection through meta-transcriptomic analysis using MDBK cells infected for two hours with a field isolate of BVDV-1. While several immune regulator genes were induced, genes involved in cell signaling, metabolic processes, development, and integrity were down-regulated, suggesting an isolation of infected cells from cell-to-cell interactions and responses to external signals. Analysis through RT-qPCR confirmed the expression of more than one hundred markers. Interestingly, there was a significant up-regulation of two negative NF-κB regulators, IER3 and TNFAIP3, indicating a possible blocking of this signaling pathway mediated by BVDV-1 infection. Additionally, several genes involved in the metabolism of reactive oxygen species were down-regulated, suggesting increased oxidative stress. Notably, a number of genes involved in cellular growth and development were also regulated during infection, including MTHFD1L, TGIF1, and Brachyury. Moreover, there was an increased expression of the genes β-catenin, caprin-2, GSK3β, and MMP-7, all of which are crucial to the Wnt signaling pathway that is implicated in the embryonic development of a variety of organisms. This meta-transcriptomic analysis provides the first data towards understanding the infection mechanisms of cytopathic BVDV-1 and the putative molecular relationship between viral and host components. PMID:26919728

  15. Vibratory strain field measurement by transverse digital holography.

    Science.gov (United States)

    Stetson, Karl A

    2015-09-20

    A method is presented for measuring vibratory strain fields using phase-stepped, image-plane digital holography. An object surface is observed along its normal vector while illuminated at equal and opposite angles by two mutually coherent laser beams. One beam is phase stepped by quarter-wavelength increments between TV frames, and the resulting images are processed to yield holographic images. Object vibrations result in zero-order Bessel function fringes in the display. The second beam is modulated at the same frequency of the object vibration and is used to shift the fringes in a manner analogous to phase step interferometry. The resulting images are processed to yield a wrapped phase map, which is unwrapped and corrected for the error associated with using zero-order Bessel functions in place of cosine functions. The unwrapped images are processed to obtain the average slopes for image segments, and these slopes are multiplied by a scale factor to convert them to strain. The analysis program used here divides the field of view into five horizontal by four vertical segments, which provide a map of the vibratory strain field. PMID:26406526

  16. Finite-element study of strain field in strained-Si MOSFET.

    Science.gov (United States)

    Liu, H H; Duan, X F; Xu, Q X

    2009-02-01

    The strain field in the channel of a p-type metal-oxide-semiconductor field effect transistor fabricated by integrating Ge pre-amorphization implantation for source/drain regions is evaluated using a finite-element method combining with large angle convergent-beam electron diffraction (LACBED). The finite-element calculation shows that there is a very large compressive strain in the top layer of the channel region caused by a low dose of Ge ion implantation in the source and drain extension regions. Moreover, a transition region is formed in the bottom of the channel region and the top of the Si substrate. These calculation results are in good agreement with the LACBED experiments. PMID:18996702

  17. Nonsingular stress and strain fields of dislocations and disclinations in first strain gradient elasticity

    OpenAIRE

    Lazar, Markus; Maugin, Gerard A.

    2005-01-01

    The aim of this paper is to study the elastic stress and strain fields of dislocations and disclinations in the framework of Mindlin's gradient elasticity. We consider simple but rigorous versions of Mindlin's first gradient elasticity with one material length (gradient coefficient). Using the stress function method, we find modified stress functions for all six types of Volterra defects (dislocations and disclinations) situated in an isotropic and infinitely extended medium. By means of thes...

  18. Four-wave dark-field electron holography for imaging strain fields

    Science.gov (United States)

    Denneulin, T.; Hÿtch, M.

    2016-06-01

    Strain characterization by transmission electron microscopy is an active area of research especially for microelectronics applications. Two-wave dark-field electron holography (DFEH) was previously introduced as a reliable strain mapping technique. Here, DFEH with four electron waves was investigated in order to image equi-displacement lines as amplitude modulations of the holographic fringes. Two perpendicular electrostatic biprisms are used to interfere three reference waves diffracted by a substrate and one object wave diffracted by an epitaxially strained region. This technique provides a different way to represent the displacement field. It might be helpful to obtain information about the strain state during in situ experiments. A dummy p-MOSFET device with embedded SiGe source and drain is used for experimental demonstration.

  19. Complete Genome Sequence of a Bovine Viral Diarrhea Virus Subgenotype 1e Strain Isolated in Switzerland

    OpenAIRE

    Stalder, Hanspeter; Schweizer, Matthias; Bachofen, Claudia

    2015-01-01

    We sequenced the complete genome of the bovine viral diarrhea virus (BVDV) strain Carlito. It belongs to the subgenotype 1e that is described in Europe only and represents the second most prevalent subgenotype in Switzerland. This is the first report of a full-length sequence of BVDV-1e.

  20. Comparison of the Immune Response Between a Pair of NCP and CP Bovine Viral Diarrhea Virus (BVDV) Type 1 Isolates

    Science.gov (United States)

    Aim: Bovine viral diarrhea virus (BVDV) is a major pathogen of cattle causing severe respiratory and reproductive disease. BVDV vaccines remain an important part of the control strategy. Previous work has described higher antibody responses in animals infected with a noncytopathic (NCP) BVDV when ...

  1. Horizontal Strain Field for the Bohemian Massif, Central Europe

    Science.gov (United States)

    Schenk, V.; Pichl, R.; Schenkova, Z.; Marek, T.

    2010-12-01

    The horizontal strain field of the Bohemian Massif, central Europe, was assessed from GNSS data monitored on permanent stations of the Geodynamic Network of the Academy of Science of the Czech Republic (GEONAS) and of the Czech Office for Surveying, Mapping and Cadastre (CZEPOS). For every area a representative motion velocity was determined. Their comparison with general motions of the Eurasian plate ascertained by the NNR-NUVEL-1A model gave deviations characterizing recent influence of the Alps to the northern geological units, in our case the Bohemian Massif. From these motions a regional pattern of the horizontal strain field for the Bohemian Massif had been calculated. It was found that (i) the northern part of the Massif is under dominant E-W extensions and (ii) slight contractions were detected for the NNE-SSW direction in eastern regions of the Massif. Obtained results will be presented and discussed from a viewpoint of the Alpine structural unit actions to surrounding geological units.

  2. 3D strain measurement in electronic devices using through-focal annular dark-field imaging

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Suhyun; Jung, Younheum; Lee, Sungho; Jung Kim, Joong; Byun, Gwangseon; Lee, Sunyoung; Lee, Haebum

    2014-11-15

    Spherical aberration correction in high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) allows us to form an electron probe with reduced depth of field. Using through-focal HAADF imaging, we experimentally demonstrated 3D strain measurement in a strained-channel transistor. The strain field distribution in the channel region was obtained by scanning an electron beam over a plan-view specimen. Furthermore, the decrease in the strain fields toward the silicon substrate was revealed at different focal planes with a 5-nm focal step. These results demonstrate that it is possible to reconstruct the 3D strain field in electronic devices. - Highlights: • Three dimensional strain fields were measured using through-focal HAADF-STEM series. • The technique was applied to the channel of a plan-view strained-silicon device. • The strain values agreed with the results obtained using cross-section specimen.

  3. Molecular analyses detect natural coinfection of water buffaloes (Bubalus bubalis) with bovine viral diarrhea viruses (BVDV) in serologically negative animals.

    Science.gov (United States)

    Craig, María I; König, Guido A; Benitez, Daniel F; Draghi, María G

    2015-01-01

    Infection of water buffaloes (Bubalus bubalis) with bovine viral diarrhea viruses (BVDV) has been confirmed in several studies by serological and molecular techniques. In order to determine the presence of persistently infected animals and circulating species and subtypes of BVDV we conducted this study on a buffalo herd, whose habitat was shared with bovine cattle (Bossp.). Our serological results showed a high level of positivity for BVDV-1 and BVDV-2 within the buffalo herd. The molecular analyses of blood samples in serologically negative animals revealed the presence of viral nucleic acid, confirming the existence of persistent infection in the buffaloes. Cloning and sequencing of the 5' UTR of some of these samples revealed the presence of naturally mix-infected buffaloes with at least two different subtypes (1a and 1b), and also with both BVDV species (BVDV-1 and BVDV-2).

  4. Complete Genome Sequence of Bovine Viral Diarrhea Virus-1 Strain Egy/Ismailia/2014, Subtype 1b

    OpenAIRE

    Soltan, Mohamed A.; Wilkes, Rebecca P.; Elsheery, Mohamed N.; Elhaig, Mahmoud M.; Riley, Matthew C.; Melissa A. Kennedy

    2015-01-01

    Here, we report the complete genome sequence of bovine viral diarrhea virus-1b (BVDV-1b), strain Egy/Ismailia/2014. The virus genome is composed of 12,217 nucleotides organized as one open reading frame encoding 3,898 amino acids. This report will assist efforts in diagnostics, studying molecular epidemiology, and control of BVDV in Egypt.

  5. Complete Genome Sequence of Bovine Viral Diarrhea Virus-1 Strain Egy/Ismailia/2014, Subtype 1b.

    Science.gov (United States)

    Soltan, Mohamed A; Wilkes, Rebecca P; Elsheery, Mohamed N; Elhaig, Mahmoud M; Riley, Matthew C; Kennedy, Melissa A

    2015-01-01

    Here, we report the complete genome sequence of bovine viral diarrhea virus-1b (BVDV-1b), strain Egy/Ismailia/2014. The virus genome is composed of 12,217 nucleotides organized as one open reading frame encoding 3,898 amino acids. This report will assist efforts in diagnostics, studying molecular epidemiology, and control of BVDV in Egypt. PMID:26701085

  6. Correlated Crust and Mantle Strain Field in China

    Institute of Scientific and Technical Information of China (English)

    Ren Jinwei

    2005-01-01

    Plate motion is one of the major dynamic sources for deformation in the crust and the mantle.Since the deformation in the crust can be observed by GPS and geological observation, the comparison between the deformation of the crust and that of the mantle becomes one of the major methods available for studying the coupling between crust movement and mantle deformation. Regional crustal strain rate tensor values in China, inferred from Quaternary fault slip rates and earthquake deformation data within areas of approximately 200 × 200 km,are interpolated with smooth, continuous functions (spline) to determine a self-consistent model velocity gradient tensor field for the present-day Chinese continent. In the interpolation process, GPS velocity vectors are also matched, within a defined frame of reference,by the model velocity field. The directions of shear deformation calculated from the model velocity field are compared with the fast directions of shear-wave splitting inferred from SKS phases and Pn waves. The results might represent the shear deformation in mantle and the deep crust,respectively. There is a relatively large difference between the average direction of crustal shear and that of mantle shear in the area of active tectonics, which may indicate that in these active areas the crust and the mantle may be decoupled.

  7. Viral Dose and Immunosuppression Modulate the Progression of Acute BVDV-1 Infection in Calves: Evidence of Long Term Persistence after Intra-Nasal Infection.

    Directory of Open Access Journals (Sweden)

    Rebecca Strong

    Full Text Available Bovine viral diarrhoea virus (BVDV infection of cattle causes a diverse range of clinical outcomes from being asymptomatic, or a transient mild disease, to producing severe cases of acute disease leading to death. Four groups of calves were challenged with a type 1 BVDV strain, originating from a severe outbreak of BVDV in England, to study the effect of viral dose and immunosuppression on the viral replication and transmission of BVDV. Three groups received increasing amounts of virus: Group A received 10(2.55TCID50/ml, group B 10(5.25TCID50/ml and group C 10(6.7TCID 50/ml. A fourth group (D was inoculated with a medium dose (10(5.25TCID50/ml and concomitantly treated with dexamethasone (DMS to assess the effects of chemically induced immunosuppression. Naïve calves were added as sentinel animals to assess virus transmission. The outcome of infection was dose dependent with animals given a higher dose developing severe disease and more pronounced viral replication. Despite virus being shed by the low-dose infection group, BVD was not transmitted to sentinel calves. Administration of dexamethasone (DMS resulted in more severe clinical signs, prolonged viraemia and virus shedding. Using PCR techniques, viral RNA was detected in blood, several weeks after the limit of infectious virus recovery. Finally, a recently developed strand-specific RT-PCR detected negative strand viral RNA, indicative of actively replicating virus, in blood samples from convalescent animals, as late as 85 days post inoculation. This detection of long term replicating virus may indicate the way in which the virus persists and/or is reintroduced within herds.

  8. A wireless sensor network design and evaluation for large structural strain field monitoring

    International Nuclear Information System (INIS)

    Structural strain changes under external environmental or mechanical loads are the main monitoring parameters in structural health monitoring or mechanical property tests. This paper presents a wireless sensor network designed for monitoring large structural strain field variation. First of all, a precision strain sensor node is designed for multi-channel strain gauge signal conditioning and wireless monitoring. In order to establish a synchronous strain data acquisition network, the cluster-star network synchronization method is designed in detail. To verify the functionality of the designed wireless network for strain field monitoring capability, a multi-point network evaluation system is developed for an experimental aluminum plate structure for load variation monitoring. Based on the precision wireless strain nodes, the wireless data acquisition network is deployed to synchronously gather, process and transmit strain gauge signals and monitor results under concentrated loads. This paper shows the efficiency of the wireless sensor network for large structural strain field monitoring

  9. A novel ultrasonic strain gauge for single-sided measurement of a local 3D strain field

    OpenAIRE

    Kersemans, Mathias; Allaer, Klaas; Paepegem, Wim Van; Van Den Abeele, Koen; Pyl, Lincy; Zastavnik, Filip; Sol, Hugo; Degrieck, Joris

    2014-01-01

    A novel method is introduced for the measurement of a 3D strain field by exploiting the interaction between ultrasound waves and geometrical characteristics of the insonified specimen. First, the response of obliquely incident harmonic waves to a deterministic surface roughness is utilized. Analysis of backscattered amplitudes in Bragg diffraction geometry then yields a measure for the in-plane strain field by mapping any shift in angular dependency. Secondly, the analysis of the reflection c...

  10. Cytopathic bovine viral diarrhea viruses (BVDV): emerging pestiviruses doomed to extinction

    OpenAIRE

    Peterhans, Ernst; Bachofen, Claudia; Stalder, Hanspeter; Schweizer, Matthias

    2010-01-01

    Bovine viral diarrhea virus (BVDV), a Flaviviridae pestivirus, is arguably one of the most widespread cattle pathogens worldwide. Each of its two genotypes has two biotypes, non-cytopathic (ncp) and cytopathic (cp). Only the ncp biotype of BVDV may establish persistent infection in the fetus when infecting a dam early in gestation, a time point which predates maturity of the adaptive immune system. Such fetuses may develop and be born healthy but remain infected for life. Due to this early in...

  11. Acoustic assisted, field-induced strain in ferromagnetic shape memory alloys

    Science.gov (United States)

    Peterson, Bradley W.; Feuchtwanger, Jorge; Chambers, Joshua M.; Bono, David; Hall, Steven R.; Allen, Samuel M.; O'Handley, Robert C.

    2004-06-01

    A technique has been developed that uses acoustic energy to assist a magnetic field in driving twin boundary motion in a NiMnGa single crystal. Acoustic assisted magnetic-field-induced strain has been observed to increase the magnetic-field-induced strain response by up to one order of magnitude. This effect is most pronounced for magnetic field drives near the twin boundary threshold field. Increasing frequency of the acoustic wave input is shown to increase strain up to about 4 kHz after which there is a small decline in FSMA strain for higher frequencies.

  12. Functionality of Chimeric E2 Glycoproteins of BVDV and CSFV in Virus Replication

    Directory of Open Access Journals (Sweden)

    H.G.P. van Gennip

    2008-01-01

    Full Text Available An intriguing difference between the E2 glycoprotein of CSFV and the other groups of pestiviruses (nonCSFV is a lack of two cysteine residues on positions cysteine 751 and 798. Other groups of pestivirus are not restricted to one species as swine, whereas CSFV is restricted to swine and wild boar. We constructed chimeric CSFV/BVDV E2 genes based on a 2D model of E2 proposed by van Rijn et al. (van Rijn et al. 1994, J Virol 68, 3934–42 and confirmed their expression by immunostaining of plasmid-transfected SK6 cells. No equivalents for the antigenic units B/C and A were found on E2 of BVDVII. This indicates major structural differences in E2. However, the immunodominant BVDVII domain A, containing epitopes with essential amino acids between position 760–764, showed to be dependent on the presence of the region defined by amino acids 684 to 796. As for the A domain of CSFV, the BVDVII A-like domain seemed to function as a separate unit. These combined domains in E2 proved to be the only combination which was functional in viral background of CSFV C-strain. The fitness of this virus (vfl c36BVDVII 684–796 seemed to be reduced compared to vfl c9 (with the complete antigenic region of BVDVII.

  13. BVDV and BHV-1 Infections in Dairy Herds in Northern and Northeastern Thailand

    Directory of Open Access Journals (Sweden)

    Chanlun A

    2004-12-01

    Full Text Available Bulk milk samples from 220 dairy herds were collected at 9 public milk collection centres in the northeastern and northern Thailand, and a subset of 11 herds was selected for individual testing. The samples were tested for presence of antibodies to BVDV and BHV-1 using an indirect ELISA. The results from the bulk milk testing demonstrated a moderate level of exposure to BVDV and BHV-1 (73% and 67%, respectively. However, the low proportion of herds with high BVDV antibody-levels (13% and the low within-herd seroprevalence of BVDV and BHV-1 in the 11 herds (24% and 5%, respectively, particularly among the young stock (15% and 0%, respectively, demonstrated a low prevalence of active BVDV infection and a low rate of reactivation of latent BHV-1. The presence of a self-clearance process was also indicated by the results from the individual testing. Moreover, a surprisingly low prevalence of BVDV and BHV-1 antibody-positive herds at one of the milk centres was found. This centre was established 5–10 years before the others. Our impression is that this reflects the self-clearance process, where consecutive replacement of imported infected animals without further spread has resulted in a nearly total elimination of the infections. Based on our experiences and on these results we are convinced that this process can continue if there is awareness of herd biosecurity. This is especially important in the context of a future intensification of the dairy production.

  14. MODE I AND MODE II CRACK TIP ASYMPTOTIC FIELDS WITH STRAIN GRADIENT EFFECTS

    Institute of Scientific and Technical Information of China (English)

    陈少华; 王自强

    2001-01-01

    The strain gradient effect becomes significant when the size of fracture process zone around a crack tip is comparable to the intrinsic material length l,typically of the order of microns. Using the new strain gradient deformation theory given by Chen and Wang, the asymptotic fields near a crack tip in an elastic-plastic material with strain gradient effects are investigated. It is established that the dominant strain field is irrotational. For mode I plane stress crack tip asymptotic field,the stress asymptotic field and the couple stress asymptotic field can not exist simultaneously. In the stress dominated asymptotic field, the angular distributions of stresses are consistent with the classical plane stress HRR field; In the couple stress dominated asymptotic field, the angular distributions of couple stresses are consistent with that obtained by Huang et al. For mode II plane stress and plane strain crack tip asymptotic fields, only the stress-dominated asymptotic fields exist. The couple stress asymptotic field is less singular than the stress asymptotic fields. The stress asymptotic fields are the same as mode II plane stress and plane strain HRR fields,respectively. The increase in stresses is not observed in strain gradient plasticity for mode I and mode II, because the present theory is based only on the rotational gradient of deformation and the crack tip asymptotic fields are irrotational and dominated by the stretching gradient.

  15. Giant magnetic-field-induced strain in Ni-Mn-Ga crystals: experimental results and modeling

    International Nuclear Information System (INIS)

    Strains up to 6% have been induced by application of magnetic fields of 320-400 kA/m (4-5 kOe) to Ni-Mn-Ga single-crystal ferromagnetic shape memory alloys at room temperature. The blocking stress (stress at which field-induced strain is zero) is in the range 1.5-2 MPa. These strains are not magnetostrictive in origin but arise rather from field-induced motion of twin boundaries in the martensitic phase. A thermodynamic model for field-induced twin-boundary motion describes the main features of the field dependence and stress dependence of the strain. All parameters of the model can be measured from experimental stress vs. strain and magnetization vs. field curves

  16. Efficacy of a BVDV subunit vaccine produced in alfalfa transgenic plants.

    Science.gov (United States)

    Peréz Aguirreburualde, María Sol; Gómez, María Cristina; Ostachuk, Agustín; Wolman, Federico; Albanesi, Guillermo; Pecora, Andrea; Odeon, Anselmo; Ardila, Fernando; Escribano, José M; Dus Santos, María José; Wigdorovitz, Andrés

    2013-02-15

    Bovine viral diarrhea virus (BVDV) is considered an important cause of economic loss within bovine herds worldwide. In Argentina, only the use of inactivated vaccines is allowed, however, the efficacy of inactivated BVDV vaccines is variable due to its low immunogenicity. The use of recombinant subunit vaccines has been proposed as an alternative to overcome this difficulty. Different studies on protection against BVDV infection have focused the E2 protein, supporting its putative use in subunit vaccines. Utilization of transgenic plants expressing recombinant antigens for the formulation of experimental vaccines represents an innovative and cost effective alternative to the classical fermentation systems. The aim of this work was to develop transgenic alfalfa plants (Medicago sativa, L.) expressing a truncated version of the structural protein E2 from BVDV fused to a molecule named APCH, that target to antigen presenting cells (APCH-tE2). The concentration of recombinant APCH-tE2 in alfalfa leaves was 1 μg/g at fresh weight and its expression remained stable after vegetative propagation. A methodology based an aqueous two phases system was standardized for concentration and partial purification of APCH-tE2 from alfalfa. Guinea pigs parentally immunized with leaf extracts developed high titers of neutralizing antibodies. In bovine, the APCH-tE2 subunit vaccine was able to induce BVDV-specific neutralizing antibodies. After challenge, bovines inoculated with 3 μg of APCH-tE2 produced in alfalfa transgenic plants showed complete virological protection. PMID:23291101

  17. Strain-Field Evaluation of Strain-Relaxed Thin SiGe Layers Fabricated by Ion Implantation Method

    Science.gov (United States)

    Sawano, Kentarou; Ozawa, Yusuke; Fukumoto, Atsushi; Usami, Noritaka; Yamanaka, Junji; Suzuki, Kumiko; Arimoto, Keisuke; Nakagawa, Kiyokazu; Shiraki, Yasuhiro

    2005-10-01

    Strain-relaxed thin SiGe layers grown on ion-implanted Si substrates were evaluated by X-ray diffraction reciprocal space mapping and spatially resolved micro-Raman spectroscopy. It was found that implantation-induced defects effectively facilitated the misfit dislocation generation and multiplication during postannealing after growth, leading to large and homogeneous strain relaxation. While in-plane strain-field fluctuation with crosshatch morphology was clearly observed in the SiGe layer without implantation, a very uniform strain distribution without such morphology was realized in the sample with implantation. These results indicate that the ion implantation method is a very promising approach for realization of high-quality and extremely thin buffer layers.

  18. Field culture of American strain of Artemia in India

    Digital Repository Service at National Institute of Oceanography (India)

    Royan, J.P.; Sumitra-Vijayaraghavan; Krishnakumari, L.

    Pilot scale culture of Artemia was carried out in a 0.22 ha condenser unit of salt pans. Pond was fertilized with inorganic salts. The nauplii of San Francisco Bay, USA strain were inoculated. Within a period of 5 months a production of 20.6 kg dry...

  19. Characterisation of bovine viral diarrhoea virus (BVDV) isolates from an outbreak with haemorrhagic enteritis and severe pneumonia.

    Science.gov (United States)

    Yeşilbağ, Kadir; Förster, Christine; Ozyiğit, M Ozgür; Alpay, Gizem; Tuncer, Pelin; Thiel, Heinz-Jürgen; König, Matthias

    2014-02-21

    During 2007 a disease outbreak occurred in cattle in the Marmara region of western Turkey characterised by severe pneumonia and haemorrhagic enteritis in calves. Cases from three farms at different locations were examined and bovine viral diarrhoea virus (BVDV) isolated in all cases. Phylogenetic characterisation of the virus isolates allocated them in a new cluster tentatively named as BVDV-1r.

  20. Giant Electric-Field-Induced Strain in PVDF-Based Battery Separator Membranes Probed by Electrochemical Strain Microscopy.

    Science.gov (United States)

    Romanyuk, Konstantin; Costa, Carlos M; Luchkin, Sergey Yu; Kholkin, Andrei L; Lanceros-Méndez, Senentxu

    2016-05-31

    Efficiency of lithium-ion batteries largely relies on the performance of battery separator membrane as it controls the mobility and concentration of Li-ions between the anode and cathode electrodes. Recent advances in electrochemical strain microscopy (ESM) prompted the study of Li diffusion and transport at the nanoscale via electromechanical strain developed under an application of inhomogeneous electric field applied via the sharp ESM tip. In this work, we observed unexpectedly high electromechanical strain developed in polymer membranes based on porous poly(vinylidene fluoride) (PVDF) and poly(vinylidene fluoride-co-chlorotrifluoroethylene) (PVDF-CTFE) and, using it, could study a dynamics of electroosmotic flow of electrolyte inside the pores. We show that, independently of the separator membrane, electric field-induced deformation observed by ESM on wetted membrane surfaces can reach up to 10 nm under a moderate bias of 1 V (i.e., more than an order of magnitude higher than that in best piezoceramics). Such a high strain is explained by the electroosmotic flow in a porous media composed of PVDF. It is shown that the strain-based ESM method can be used to extract valuable information such as average pore size, porosity, elasticity of membrane in electrolyte solvent, and membrane-electrolyte affinity expressed in terms of zeta potential. Besides, such systems can, in principle, serve as actuators even in the absence of apparent piezoelectricity in amorphous PVDF. PMID:27142946

  1. Study on the Horizontal Deformation Strain Field in the Central and Northern Parts of Yunnan Province

    Institute of Scientific and Technical Information of China (English)

    Li Yanxing; Guo Liangqian; Zhang Zhongfu

    2003-01-01

    Based on the horizontal deformation field and the strain field derived from the GPS data over the period of 1999~2001 in the Yunnan area, the characteristics of deformation and strain in the northern part of Yunnan Province have been studied. The results indicate that the central part of the studied area is rather stable with little crustal displacement, while the western and eastern parts are active with larger displacement. The strain field reveals that the orientations of the principal compressive strain axis of the crust and the sub-blocks in the area are NW-SE, while the orientations of the principal tensile strain axis is NE-SW. In the studied area, the tensile strain is predominatly in the northern part and the compressive strain is predominatly in the central and southern parts. The stretching direction of the shear-strain contour is basically consistent with the strike of the active fault. The strain and stress fields of the fault activity are related to the structure where the fault is located, while the activity properties of the faults are different.

  2. Carrier fringe method of moiré interferometry for tiny strain measurements in micro-field

    Institute of Scientific and Technical Information of China (English)

    Yudong Cao; Shibin Wang; Shuangxi Qi; Jingwei Tong

    2009-01-01

    In this paper, we demonstrate a new optical method for tiny strain measurements based on the principle of with frequency of 1200 lp/mm is replicated on the specimen surface, and the strain can be deduced from the changes in carrier fringes before and after the deformation of an object. Four coherent laser beams are used to obtain the carrier fringe patterns of field U and V. Both theoretical analysis and numerical simulation indicate that the ideal accuracy of strain can be controlled within a range of ±1με. Case study of a plane extension experiment shows that the measu-rement accuracy of strain can be controlled within the range of±10με. The average strain values of every row of field U and every column of field V can be obtained by using this method, and approximated strain of every pixel in the whole-field can be further acquired, and thus it is possible to measure tiny strains occurred in a micro-field. The techno-logy in this paper can provide comprehensive information for analyzing related mechanical content in the field of MEMS.

  3. Dynamical effects in strain measurements by dark-field electron holography

    Energy Technology Data Exchange (ETDEWEB)

    Javon, E. [CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse (France); EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Lubk, A. [CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse (France); EMAT, University of Antwerp, Groenenborgerlaan 171, 2020 Antwerp (Belgium); Institute of Structure Physics, Technische Universität Dresden, 01062 Dresden (Germany); Cours, R. [CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse (France); Reboh, S. [CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse (France); CEA, LETI, Minatec Campus, 17 rue de Martyrs, 38054 Grenoble (France); Cherkashin, N.; Houdellier, F.; Gatel, C.; Hÿtch, M.J. [CEMES-CNRS and Université de Toulouse, 29 rue Jeanne Marvig, F-31055 Toulouse (France)

    2014-12-15

    Here, we study the effect of dynamic scattering on the projected geometric phase and strain maps reconstructed using dark-field electron holography (DFEH) for non-uniformly strained crystals. The investigated structure consists of a {SiGe/Si} superlattice grown on a (001)-Si substrate. The three-dimensional strain field within the thin TEM lamella is modelled by the finite element method. The observed projected strain is simulated in two ways by multiplying the strain at each depth in the crystal by a weighting function determined from a recently developed analytical two-beam dynamical theory, and by simply taking the average value. We demonstrate that the experimental results need to be understood in terms of the dynamical theory and good agreement is found between the experimental and simulated results. Discrepancies do remain for certain cases and are likely to be from an imprecision in the actual two-beam diffraction conditions, notably the deviation parameter, and points to limitations in the 2-beam approximation. Finally, a route towards a 3D reconstruction of strain fields is proposed. - Highlights: • We explain DFEH strain map thanks to a recent theoretical development. • The projection measured by DFEH is a weighted average of the strain along the e-beam. • The weighting function depends on diffracted beam, thickness and sample orientation. • The weighting functions were included in FEM simulation and compared to DFEH results. • Kinematic conditions avoid the dynamical effects and lead to the average strain value.

  4. Effect of strain field on displacement cascade in tungsten studied by molecular dynamics simulation

    Science.gov (United States)

    Wang, D.; Gao, N.; Wang, Z. G.; Gao, X.; He, W. H.; Cui, M. H.; Pang, L. L.; Zhu, Y. B.

    2016-10-01

    Using atomistic methods, the coupling effect of strain field and displacement cascade in body-centered cubic (BCC) tungsten is directly simulated by molecular dynamics (MD) simulations at different temperatures. The values of the hydrostatic and uniaxial (parallel or perpendicular to primary knock-on atom (PKA) direction) strains are from -2% to 2% and the temperature is from 100 to 1000 K. Because of the annealing effect, the influence of strain on radiation damage at low temperature has been proved to be more significant than that at high temperature. When the cascade proceeds under the hydrostatic strain, the Frenkel Pair (FP) production, the fraction of defect in cluster and the average size of the defect cluster, all increase at tensile state and decrease at compressive state. When the cascade is under uniaxial strain, the effect of strain parallel to PKA direction is less than the effect of hydrostatic strain, while the effect of strain perpendicular to PKA direction can be negligible. Under the uniaxial strain along direction, the SIA and SIA cluster is observed to orientate along the strain direction at tensile state and the uniaxial compressive strain with direction perpendicular to has led to the similar preferred nucleation. All these results indicate that under irradiation, the tensile state should be avoided for materials used in nuclear power plants.

  5. Validation of a novel fiber optic strain gauge in a cryogenic and high magnetic field environment

    Science.gov (United States)

    Baxter, Scott; Lakrimi, M.'hamed; Thomas, Adrian M.; Gao, Yunxin; Blakes, Hugh; Gibbens, Paul; Looi, Mengche

    2010-10-01

    We report on the first operation of an easy to use low cost novel fiber optic strain gauge (FOSG) in cryogenic and magnetic field environments. The FOSGs were mounted on a superconducting coil and resin impregnated. The gauges detected resin shrinkage upon curing. On cooldown, the FOSG monitored the thermal contraction strains of the coil and the electromagnetic strain during energization. The coil was deliberately quenched, in excess of 175 times, and again the FOSG detected the quenches and measured the thermal expansion-induced strains and subsequent re-cooling of the coil after a quench. Agreement with FEA predictions was very good.

  6. Genetic diversity and frequency of bovine viral diarrhea virus (BVDV) detected in cattle in Turkey

    Science.gov (United States)

    Rapid detection and culling of persistently infected animals and efficacious vaccination are key factors to control bovine viral diarrhea virus (BVDV) infections in cattle. The aim of this study was to investigate frequency of detection of persistently infected cattle and examine the diversity of bo...

  7. Whole Genome Analysis of Response to BVDV2 Vaccinations in Angus Calves Using Bayesian Models

    Science.gov (United States)

    This study was designed to evaluate the impact of environmental factors and genetic controls on response to vaccination against bovine viral diarrhea virus type 2 (BVDV2) in Purebred American Angus beef cattle. This study utilized 245 Angus calves born in the spring (n = 139) and fall (n = 106) of 2...

  8. Characterization and detection of BVDV related reproductive disease in white tail deer

    Science.gov (United States)

    Introduction Bovine viral diarrhea viruses (BVDV) are the causative agent of reproductive and respiratory disease in cattle resulting in significant economic loss to the beef and dairy industries. The primary consequences of reproductive infection are due to the direct infection of the fetus and th...

  9. Strain Field in GaAs/GaN Wafer-Bonding Interface and Its Microstructure

    Institute of Scientific and Technical Information of China (English)

    WU Di; GUO Xia; GU Xiao-Ling; LI Yi-Bo; SHEN Guang-Di

    2007-01-01

    The strain fields in a wafer-bonded GaAs/GaN structure aFe measured by electron backscatter diffraction (EBSD).Image quality (IQ) of EBSD Kikuchi patterns and rotation angles of crystal lattices as strain sensirive parameters aFe employed to characterize the distortion and the rotation of crystal lattices in the GaAs-interface-GaN structure.as well as to display the strain fields.The results indicate that the influence region of the strains in the wafer-bonded GaAs/GaN structure is mainly located in GaAs side because the strength of GaAs is weaker than that of GaN.The cross-sectional image of transmission electron microscopy (TEM) further reveals the distortion and the rotation of crystal lattices induced by strains systematically.

  10. Field monitoring of static, dynamic, and statnamic pile loading tests using fibre Bragg grating strain sensors

    Science.gov (United States)

    Li, Jin; Correia, Ricardo P.; Chehura, Edmon; Staines, Stephen; James, Stephen W.; Tatam, Ralph; Butcher, Antony P.; Fuentes, Raul

    2009-10-01

    Pile loading test plays an important role in the field of piling engineering. In order to gain further insight into the load transfer mechanism, strain gauges are often used to measure local strains along the piles. This paper reports a case whereby FBG strain sensors was employed in a field trial conducted on three different types of pile loading tests in a glacial till. The instrumentation systems were configured to suit the specific characteristic of each type of test. Typical test results are presented. The great potential of using FBG sensors for pile testing is shown.

  11. Outer Membrane Proteins of Brucella abortus Vaccinal and Field Strains and their Immune Response in Buffaloes

    OpenAIRE

    Rukhshanda Munir*, M. Afzal1, M. Hussain2, S. M. S. Naqvi3 and A. Khanum3

    2010-01-01

    Outer membrane proteins (OMPs) of three strains of B. abortus i.e. S19, RB51 and a local field isolate of biotype 1 were isolated through disrupting cells to generate membranes by centrifugation and sodium lauryl sarcosinate solubilisation of inner membrane proteins. Distinct OMP profiles of each strain were seen on SDS-PAGE. SDS-PAGE analysis of S19 and field isolate revealed eight protein bands in each strain. The OMPs of S19 had molecular masses 89.0, 73.0, 53.7, 49.0, 38.0, 27.0, 22.3, a...

  12. Strain and electric field control of hyperfine interactions for donor spin qubits in silicon

    Science.gov (United States)

    Usman, M.; Hill, C. D.; Rahman, R.; Klimeck, G.; Simmons, M. Y.; Rogge, S.; Hollenberg, L. C. L.

    2015-06-01

    Control of hyperfine interactions is a fundamental requirement for quantum computing architecture schemes based on shallow donors in silicon. However, at present, there is lacking an atomistic approach including critical effects of central-cell corrections and nonstatic screening of the donor potential capable of describing the hyperfine interaction in the presence of both strain and electric fields in realistically sized devices. We establish and apply a theoretical framework, based on atomistic tight-binding theory, to quantitatively determine the strain and electric-field-dependent hyperfine couplings of donors. Our method is scalable to millions of atoms, and yet captures the strain effects with an accuracy level of DFT method. Excellent agreement with the available experimental data sets allow reliable investigation of the design space of multiqubit architectures, based on both strain only as well as hybrid (strain + field) control of qubits. The benefits of strain are uncovered by demonstrating that a hybrid control of qubits based on (001) compressive strain and in-plane (100 or 010) fields results in higher gate fidelities and or faster gate operations, for all of the four donor species considered (P, As, Sb, and Bi). The comparison between different donor species in strained environments further highlights the trends of hyperfine shifts, providing predictions where no experimental data exists. While faster gate operations are realizable with in-plane fields for P, As, and Sb donors, only for the Bi donor, our calculations predict faster gate response in the presence of both in-plane and out-of-plane fields, truly benefiting from the proposed planar field control mechanism of the hyperfine interactions.

  13. Bovine viral diarrhea virus (BVDV) infection in dairy cattle herds in northeast Thailand.

    Science.gov (United States)

    Nilnont, Theerakul; Aiumlamai, Suneerat; Kanistanont, Kwankate; Inchaisri, Chaidate; Kampa, Jaruwan

    2016-08-01

    Bovine viral diarrhea virus causes a wide range of clinical manifestation with subsequent economic losses in dairy production worldwide. Our study of a population of dairy cattle in Thailand based on 933 bulk tank milk samples from nine public milk collection centers aimed to monitor infective status and to evaluate the effect of the infection in cows as well as to examine the reproductive performance of heifers to provide effective recommendations for disease control in Thailand. The results showed a moderate antibody-positive prevalence in the herd (62.5 %), with the proportion of class-3 herd, actively infected stage, being 17.3 %. Fourteen persistently infected (PI) animals were identified among 1196 young animals from the class-3 herds. Most of the identified PI animals, 11/14, were born in one sub-area where bovine viral diarrhea virus (BVDV) investigation has not been performed to date. With respect to reproductive performance, class-3 herds also showed higher median values of reproductive indices than those of class-0 herds. Cows and heifers in class-3 herds had higher odds ratio of calving interval (CI) and age at first service (AFS) above the median, respectively, compared to class-0 herds (OR = 1.29; P = 0.02 and OR = 1.63; P = 0.02). Our study showed that PI animals were still in the area that was previously studied. Furthermore, a newly studied area had a high prevalence of BVDV infection and the infection affected the reproductive performance of cows and heifers. Although 37.5 % of the population was free of BVDV, the lack of official disease prevention and less awareness of herd biosecurity may have resulted in continuing viral spread and silent economic losses have potentially occurred due to BVDV. We found that BVDV is still circulating in the region and, hence, a national control program is required. PMID:27154218

  14. Phenomenology of giant magnetic-field-induced strain in ferromagnetic shape-memory materials (invited)

    Energy Technology Data Exchange (ETDEWEB)

    O' Handley, R. C. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Murray, S. J. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Marioni, M. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Nembach, H. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Allen, S. M. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

    2000-05-01

    Ferromagnetic shape-memory alloys have recently emerged as a new class of active materials showing very large magnetic-field-induced extensional strains. Recently, a single crystal of a tetragonally distorted Heusler alloy in the NiMnGa system has shown a 5% shear strain at room temperature in a field of 4 kOe. The magnetic and crystallographic aspects of the twin-boundary motion responsible for this effect are described. Ferromagnetic shape-memory alloys strain by virtue of the motion of the boundaries separating adjacent twin variants. The twin-boundary motion is driven by the Zeeman energy difference between the adjacent twins due to their nearly orthogonal magnetic easy axes and large magnetocrystalline anisotropy. The twin boundary constitutes a nearly 90 degree sign domain wall. Essentially, twin-boundary motion shorts out the more difficult magnetization rotation process. The field and stress dependence of the strain are reasonably well accounted for by minimization of a simple free energy expression including Zeeman energy, magnetic anisotropy energy, internal elastic energy, and external stress. Models indicate the limits to the magnitude of the field-induced strain and point to the material parameters that make the effect possible. The field-induced strain in ferromagnetic shape-memory alloys is contrasted with the more familiar phenomenon of magnetostriction. (c) 2000 American Institute of Physics.

  15. Validation of the Abbreviated Brucella AMOS PCR as a Rapid Screening Method for Differentiation of Brucella abortus Field Strain Isolates and the Vaccine Strains, 19 and RB51

    OpenAIRE

    Ewalt, Darla R; Bricker, Betsy J.

    2000-01-01

    The Brucella AMOS PCR assay was previously developed to identify and differentiate specific Brucella species. In this study, an abbreviated Brucella AMOS PCR test was evaluated to determine its accuracy in differentiating Brucella abortus into three categories: field strains, vaccine strain 19 (S19), and vaccine strain RB51/parent strain 2308 (S2308). Two hundred thirty-one isolates were identified and tested by the conventional biochemical tests and Brucella AMOS PCR. This included 120 isola...

  16. Evaluation of micro-behavior of strain field in Chinese mainland with the GPS time series

    Institute of Scientific and Technical Information of China (English)

    JING Shao-qun; WANG Jia-wei; WU Yun; ZHOU Shuo-yu; SHI Shun-ying

    2006-01-01

    Based on the time series of GPS station coordinate in the international Earth reference frame (ITRF), we evaluate annual micro-behavior of strain field in Chinese mainland with the triangle method. The results show that the annual micro-behavior of strain field is divided into two parts by the north-south earthquake belt in the research region. The prevailing direction of compressive principal strain field is nearly consistent in the western region. From west to east,the direction varies from NS to NE. It is in accordance with the direction of the modern compressive principal strain field. This suggests that geologic deformation in western region was mainly caused by that India tectonic plate pushes the research region northward and the Siberia plate pushes it southward relatively. It is an inheritance of new tectonic motion. The prevailing direction of the compressive principal strain field does not exist in the eastern region .The annual biggest shear strain is different greatly in every grid-cell. The values varies from 4.13×10-8 to 7.0×10-10. By and large the annual biggest shear strain in the western region is bigger than that in the eastern region. And so is the variation between any two consecutive biggest annual shear strains in the same grid-cell. The annual surface dilatation show that in most grid-cells of the research region the surface dilatation is in compressibility, and the variation between any two consecutive annual surface dilatation in the same grid-cell is small.

  17. Outer Membrane Proteins of Brucella abortus Vaccinal and Field Strains and their Immune Response in Buffaloes

    Directory of Open Access Journals (Sweden)

    Rukhshanda Munir*, M. Afzal1, M. Hussain2, S. M. S. Naqvi3 and A. Khanum3

    2010-04-01

    Full Text Available Outer membrane proteins (OMPs of three strains of B. abortus i.e. S19, RB51 and a local field isolate of biotype 1 were isolated through disrupting cells to generate membranes by centrifugation and sodium lauryl sarcosinate solubilisation of inner membrane proteins. Distinct OMP profiles of each strain were seen on SDS-PAGE. SDS-PAGE analysis of S19 and field isolate revealed eight protein bands in each strain. The OMPs of S19 had molecular masses 89.0, 73.0, 53.7, 49.0, 38.0, 27.0, 22.3, and 17.7 kDa, while field isolate had OMPs of 151.3, 89.0, 75.8, 67.6, 37.0, 27.0, 24.0 and 19.0 kDa. B. abortus RB51 yielded 11 OMP bands ranging from 12.5 to 107.1 kDa, with 34.2, 15.8 and 12.5 kDa as additional OMPs. Western immunoblot analysis using antisera raised against all three strains in buffaloes indicated an almost similar pattern of immuno-reactive OMPs in S19 and field strain. Two OMPs of molecular weight 37-38 and 19 kDa were immuno-reactive in all strains in buffaloes. There is possibility of use of these OMPs in a recombinant vaccine for B. abortus. A distinct protein of molecular weight of 151.3 kDa was identified in field strain but not in both vaccine strains of B. abortus. Use of this OMP in a diagnostic assay may differentiate between vaccinated and infected animals.

  18. Non-Abelian SU(2) gauge fields through density-wave order and strain in graphene

    OpenAIRE

    Gopalakrishnan, Sarang; Ghaemi, Pouyan; Ryu, Shinsei

    2012-01-01

    Spatially varying strain patterns can qualitatively alter the electronic properties of graphene, acting as effective valley-dependent magnetic fields and giving rise to pseudo-Landau-level (PLL) quantization. Here, we show that the strain-induced magnetic field is one component of an SU(2) non-Abelian gauge field within the low-energy theory of graphene, and identify the other two components as period-3 charge-density waves. We show that these density-waves, if spatially varied, give rise to ...

  19. Strained silicon/silicon germanium heterojunction n-channel metal oxide semiconductor field effect transistors

    CERN Document Server

    Olsen, S H

    2002-01-01

    Investigations into the performance of strained silicon/silicon-germanium (Si/SiGe) n-channel metal-oxide-semiconductor field effect transistors (MOSFETs) have been carried out. Theoretical predictions suggest that use of a strained Si/SiGe material system with advanced material properties compared with conventional silicon allows enhanced MOSFET device performance. This study has therefore investigated the practical feasibility of obtaining superior electrical performance using a Si/SiGe material system. The MOSFET devices consisted of a strained Si surface channel and were fabricated on relaxed SiGe material using a reduced thermal budget process in order to preserve the strain. Two batches of strained Si/SiGe devices fabricated on material grown by differing methods have been analysed and both showed good transistor action. A correlation of electrical and physical device data established that the electrical device behaviour was closely related to the SiGe material quality, which differed depending on growt...

  20. Quantum capacitance in topological insulators under strain in a tilted magnetic field

    KAUST Repository

    Tahir, M.

    2012-12-06

    Topological insulators exhibit unique properties due to surface states of massless Dirac fermions with conserved time reversal symmetry. We consider the quantum capacitance under strain in an external tilted magnetic field and demonstrate a minimum at the charge neutrality point due to splitting of the zeroth Landau level. We also find beating in the Shubnikov de Haas oscillations due to strain, which originate from the topological helical states. Varying the tilting angle from perpendicular to parallel washes out these oscillations with a strain induced gap at the charge neutrality point. Our results explain recent quantum capacitance and transport experiments.

  1. A Strained Organic Field-Effect-Transistor with a Gate-Tunable Superconducting Channel

    OpenAIRE

    Yamamoto, Hiroshi M.; Nakano, Masaki; Suda, Masayuki; Iwasa, Yoshihiro; Kawasaki, Masashi; Kato, Reizo

    2013-01-01

    In state-of-the-art silicon devices, mobility of the carrier is enhanced by the lattice strain from the back substrate. Such an extra control of device performance is significant in realizing high performance computing and should be valid for electric-field-induced superconducting devices, too. However, so far, the carrier density is the sole parameter for field-induced superconducting interfaces. Here we show an active organic superconducting field-effect-transistor whose lattice is modulate...

  2. Magnetization states in epitaxial thin films subjected to misfit strains and demagnetization field

    Energy Technology Data Exchange (ETDEWEB)

    Yuan, Junqing [Department of Applied Mathematics, School of Science, Zhejiang University of Technology, Hangzhou, Zhejiang 310014 (China); Wang, Jie, E-mail: jw@zju.edu.cn [Institute of Applied Mechanics, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou, Zhejiang 310027 (China)

    2015-01-15

    The effect of non-equally biaxial in-plane misfit strains and demagnetization field on the magnetization states of ferromagnetic thin films is analytically investigated by using a nonlinear thermodynamic theory. The “misfit strain–misfit strain” phase diagrams of the magnetization states at room temperature for α-Fe and CoFe{sub 2}O{sub 4} thin films epitaxially grown on tetragonal substrates are developed by minimizing the total free energy. For a cubic ferromagnetic thin film, an out-of-plane magnetization state exists in the region of tensile misfit strains if the magnetostrictive coefficient of λ{sub 100} is negative and the demagnetization field is small, whereas the out-of-plane magnetization vanishes in the whole region of misfit strains when the demagnetization field is large.

  3. Modelling the spread of bovine viral diarrhea virus (BVDV) in a beef cattle herd and its impact on herd productivity

    OpenAIRE

    Damman, Alix; Viet, Anne France; Arnoux, Sandie; Guerrier-Chatellet, Marie-Claude; Petit, Etienne; Ezanno, Pauline

    2015-01-01

    Bovine viral diarrhea virus (BVDV) is a common pathogen of cattle herds that causes economic losses due to reproductive disorders in breeding cattle and increased morbidity and mortality amongst infected calves. Our objective was to evaluate the impact of BVDV spread on the productivity of a beef cow-calf herd using a stochastic model in discrete time that accounted for (1) the difference in transmission rates when animals are housed indoors versus grazing on pasture, (2) the external risk of...

  4. Identificação do vírus da Diarréia Viral Bovina tipo 2 (BVDV-2 no sul do Brasil Identification of bovine virus diarrhea virus type-2 (BVDV-2 in southern Brazil

    Directory of Open Access Journals (Sweden)

    Eduardo F. Flores

    2000-06-01

    Full Text Available Amostras do vírus da Diarréia Viral Bovina (BVDV, denominadas de BVDV tipo 2 (BVDV-2, foram inicialmente identificadas em surtos de BVD aguda e enfermidade hemorrágica e têm sido isoladas predominantemente na América do Norte. O presente artigo descreve dois casos de enfermidade gastroentérica/respiratória seguidos de isolamento e identificação de amostras de BVDV tipo 2 no sul do Brasil. Os vírus foram isolados de duas novilhas de diferentes rebanhos. Um dos animais apresentou enfermidade aguda, cursando com anorexia, atonia ruminal, diarréia escura ou muco-sanguinolenta, tenesmo e descarga nasal muco-purulenta. O outro animal desenvolveu enfermidade de longa duração (7 meses, caracterizada por crescimento retardado, anorexia, quadros recorrentes de diarréia, dermatite interdigital, hemorragias digestivas e genitais ocasionais, conjuntivite, artrite e pneumonia crônica. Congestão disseminada das mucosas, ulcerações extensivas e profundas na língua, palato e esôfago, áreas necróticas na mucosa do rúmen, áreas de congestão e ulcerações cobertas com fibrina no intestino delgado foram os achados mais proeminentes. Antígenos do BVDV foram demonstrados por imunohistoquí-mica no epitélio da língua, nos pulmões e em linfonodos mesentéricos. Amostras não-citopáticas do BVDV foram isoladas em cultivo celular a partir de leucócitos e do baço dos animais afetados e identificadas por imunofluorescência. Caracterização antigênica e análise filogenética desses isolados, e de outras duas amostras de BVDV isoladas de fetos coletados em matadouros, revelou tratar-se de BVDV tipo 2. A presença do BVDV tipo 2 na população bovina do Brasil possui um significado epidemiológico importante e pode ter conseqüências para o diagnóstico, estratégias de imunização e produção de vacinas.Highly virulent bovine viral diarrhea virus (BVDV isolates, named BVDV type-2 (BVDV-2, were initially identified in outbreaks of acute

  5. Experimental inoculation of calves with atypical Hobi-like pestivirus shows pattern similar to BVDV-1

    DEFF Research Database (Denmark)

    Larska, Magdalena; Polak, Mirosław P.; Uttenthal, Åse;

    of experimental inoculation of European cattle with atypical pestivirus. The experiment included 4 groups of 5 calves each inoculated with: BVDV-1 (Ho916), Hobi-like pestivirus (Th/04_KhonKaen), a mixture of both viruses or EaglesMEM (control animals). Th/04_KhonKaen induced milder clinical signs than observed...... studies show that the viruses which were thought to be restricted to South America and Southeast Asia, may have reached other continents, including Europe. The pathogenesis of the infection with Hobi-like viruses has not yet been fully elucidated. The purpose of our study was to investigate the course...... has shown that Hobi-like viruses share similar to BVDV-1clinical pattern inducing rather subclinical disease with apparent immunosuppression of the host....

  6. Absolute quantification of Bovine Viral Diarrhea Virus (BVDV) RNA by the digital PCR technique

    Science.gov (United States)

    Flatschart, R. B.; Almeida, D. O.; Heinemann, M. B.; Medeiros, M. N.; Granjeiro, J. M.; Folgueras-Flatschart, A. V.

    2015-01-01

    The quality control of cell lines used in research and industry is critical to ensure confidence in experimental results and to guarantee the safety of biopharmaceuticals to consumers. The BVDV is a common adventitious agent in many cell lines. We preliminarly evaluate the use of Digital Droplet PCR (ddPCR) for the detection and enumeration of genome copies of BVDV in cell culture and on FBS. The application of a commercial Real-Time PCR kit with the ddPCR technique was successful on different matrices. The technique allowed the absolute quantification of the genome without the use of calibration standards, suggesting its promising application on the development of reference materials for quantification of nucleic acids.

  7. Absolute quantification of Bovine Viral Diarrhea Virus (BVDV) RNA by the digital PCR technique

    International Nuclear Information System (INIS)

    The quality control of cell lines used in research and industry is critical to ensure confidence in experimental results and to guarantee the safety of biopharmaceuticals to consumers. The BVDV is a common adventitious agent in many cell lines. We preliminarly evaluate the use of Digital Droplet PCR (ddPCR) for the detection and enumeration of genome copies of BVDV in cell culture and on FBS. The application of a commercial Real-Time PCR kit with the ddPCR technique was successful on different matrices. The technique allowed the absolute quantification of the genome without the use of calibration standards, suggesting its promising application on the development of reference materials for quantification of nucleic acids

  8. Current horizontal strain field in Chinese mainland derived from GPS data

    Institute of Scientific and Technical Information of China (English)

    杨国华; 李延兴; 韩月萍; 胡新康; 巩曰沐

    2002-01-01

    The current crustal horizontal strain field is given in the paper based on the horizontal movement rates obtained from about 400 GPS stations located in Chinese mainland and its surrounding areas. The results show: a) The horizontal strain in Chinese mainland is "strong in the west and weak in the east" and the shear strain is larger than the normal strain (absolute magnitude). The general strain magnitude is 10-8/a and in local regions is 10-7/a, but the strain distribution is not homogeneous; b) The regions with the most significant NS-trending strains are the Himalayas belt along the western segment of Chinese southern boundary, the segment of 36°N~42°N along the western boundary and the northern margin of Qaidam block; c) The EW-trending strain variation along the western margin is the maximum and it is characterized by the alternatively positive and negative variations from the west to the east; d) The regions with larger magnitudes of REN (NE-trending shear strain) and Rmax (maximum shear strain) are Himalayas belt, the segment of 36°N~42°N along the western boundary, the western part of Qaidam block, Sichuan-Yunnan (Chuan-Dian) rhombic block and the border area of Alxa, Qilian and Tarim blocks; e) The surrounding area of Qinghai-Xizang (Qingzang) block is mainly superfacial contraction and its interior is basically superfacial expansion. The area to its north is mainly superfacial contraction with the maximum magnitude along the western boundary and the minimum magnitude in the eastern part (except Yanshan tectonic zone); f) In the west of the western part, the principal compressive strain is in the SN direction and the principal tensile strain is in the EW direction, while in the eastern margin area of the western part, the principal compressive strain is proximate EW and the principal tensile strain is about SN. The principal strain direction of Chuan-Dian rhombic block has changed greatly. In the northern part, it is compression in the EW and

  9. Strain- and electric field-induced band gap modulation in nitride nanomembranes.

    Science.gov (United States)

    Amorim, Rodrigo G; Zhong, Xiaoliang; Mukhopadhyay, Saikat; Pandey, Ravindra; Rocha, Alexandre R; Karna, Shashi P

    2013-05-15

    The hexagonal nanomembranes of the group III-nitrides are a subject of interest due to their novel technological applications. In this paper, we investigate the strain- and electric field-induced modulation of their band gaps in the framework of density functional theory. For AlN, the field-dependent modulation of the bandgap is found to be significant whereas the strain-induced semiconductor-metal transition is predicted for GaN. A relatively flat conduction band in AlN and GaN nanomembranes leads to an enhancement of their electronic mobility compared to that of their bulk counterparts. PMID:23604312

  10. Different resistance patterns of reference and field strains of Brucella abortus

    OpenAIRE

    Karina L. Miranda; Elaine M S Dorneles; Poester, Fernando P; Paulo S. Martins Filho; Pauletti, Rebeca B.; Andrey P. Lage

    2015-01-01

    The aim of this study was to evaluate the growth of the B. abortus reference strains and field isolates on media containing different inhibitor agents. Reference strains were seeded on tryptose agar containing: i-erythritol (1.0 mg/mL), fuchsin (20 μg/mL and 80 μg/mL), thionin (2.5 μg/mL and 10 μg/mL), rifampicin (200 μg/mL) and safranin O (200 μg/mL). Field isolates were tested only on media containing i-erythritol, rifampicin and thionin. Furthermore, each suspension was also inoculated on ...

  11. Enhanced electric field-induced strain in non-percolative carbon nanopowder/polyurethane composites

    International Nuclear Information System (INIS)

    This study deals with the improvement of electric field-induced thickness strain of polyurethane (PU) elastomer films by carbon black (C) nanopowder incorporation in the polymer matrix. Different carbon volume concentrations-0.5, 0.7, 1 and 1.5%-have been tested. Weak-field dielectric and resistivity measurements revealed that a percolative effect is not induced by carbon filling up to 1.5 vol%. Thickness strain measurements showed that both pure PU and C/PU composite films exhibit similar strain variations which are not governed only by electrostatic forces (Maxwell stress) and/or electrostriction forces. The highest strain amplitude value observed was obtained for 1% C composite thin film (Sa = -7.4% at E = 17.8 kV mm-1). In comparison the highest Sa for pure PU thin film was -6.7% at E = 37.5 kV mm-1). In the case of thick samples, the thickness strain was not enhanced by C loading, which strongly suggests interfacial space charge effects in pure PU film, confirmed by the frequency dependence of strain level

  12. Strain localization in carbonate rocks experimentally deformed in the ductile field

    Science.gov (United States)

    Rybacki, E.; Morales, L. F. G.; Dresen, G.

    2012-04-01

    The deformation of rocks in the Earth's crust is often localized, varying from brittle fault gauges in shallow environments to mylonites in ductile shear zones at greater depth. A number of theoretical, experimental, and field studies focused on the evolution and extend of brittle fault zones, but little is known so far about initiation of ductile shear zones. Strain localization in rocks deforming at high temperature and pressure may be induced by several physical, chemical, or structurally-related mechanisms. We performed simple and pure shear deformation experiments on carbonate rocks containing structural inhomogenities in the ductile deformation regime. The results may help to gain insight into the evolution of high temperature shear zones. As starting material we used cylindrical samples of coarse-grained Carrara marble containing one or two 1 mm thin artificially prepared sheets of fine-grained Solnhofen limestone, which act as soft inclusions under the applied experimental conditions. Length and diameter of the investigated solid and hollow cylinders were 10-20 mm and 10-15 mm, respectively. Samples were deformed in a Paterson-type gas deformation apparatus at 900° C temperature and confining pressures of 300 and 400 MPa. Three samples were deformed in axial compression at a bulk strain rate of 8x10-5 s-1to axial strains between 0.02 and 0.21 and 15 samples were twisted in torsion at a bulk shear strain rate of 2x10-4 s-1 to shear strains between 0.01 and 3.74. At low strain, specimens deformed axially and in torsion show minor strain hardening that is replaced by strain weakening at shear strains in excess of about 0.2. Peak shear stress at the imposed condition is about 20 MPa. Strain localized strongly within the weak inclusions as indicated by inhomogeneous bending of initially straight strain markers on sample jackets. Maximum strain concentration within inclusions with respect to the adjacent matrix was between 4 and 40, depending on total strain and

  13. Different resistance patterns of reference and field strains of Brucella abortus

    Directory of Open Access Journals (Sweden)

    Karina L. Miranda

    2015-03-01

    Full Text Available The aim of this study was to evaluate the growth of the B. abortus reference strains and field isolates on media containing different inhibitor agents. Reference strains were seeded on tryptose agar containing: i-erythritol (1.0 mg/mL, fuchsin (20 μg/mL and 80 μg/mL, thionin (2.5 μg/mL and 10 μg/mL, rifampicin (200 μg/mL and safranin O (200 μg/mL. Field isolates were tested only on media containing i-erythritol, rifampicin and thionin. Furthermore, each suspension was also inoculated on tryptose agar incubated in air, to test its ability to grow without CO2. Sensitivity to fuchsin was similar among reference strains evaluated. Growth of S19, 544 and 2308 but not RB51 were inhibited on media containing rifampicin. Medium with safranin O showed no inhibition for RB51, 544 and 2308, but it partially inhibited the S19 growth as well as medium containing i-erythritol. Treatment/control growth ratio for 2308 on tryptose agar containing thionin (2.5 μg/mL was approximatelly 1.0, whereas S19 and RB51 showed 0.85 and 0.89 ratios, respectively. Growth of 544, S19 and RB51 but not 2308 was completely inhibited on medium with thionin (10 μg/mL. All field strains grew on medium containing i-erythritol, but were completelly inhibited by rifampicin. With exception of A1 (B. abortus biovar 3 all field isolates grew on medium with thionin, although some strains showed a treatment/control growth ratio of 0.75–0.80 (10 μg/mL. These results showed that tryptose agar with thionin, i-erythritol or rifampicin could be useful for differentiating vaccine, challenge and field strains of B. abortus.

  14. Different resistance patterns of reference and field strains of Brucella abortus

    Science.gov (United States)

    Miranda, Karina L.; Dorneles, Elaine M. S.; Poester, Fernando P.; Martins, Paulo S.; Pauletti, Rebeca B.; Lage, Andrey P.

    2015-01-01

    The aim of this study was to evaluate the growth of the B. abortus reference strains and field isolates on media containing different inhibitor agents. Reference strains were seeded on tryptose agar containing: i-erythritol (1.0 mg/mL), fuchsin (20 μg/mL and 80 μg/mL), thionin (2.5 μg/mL and 10 μg/mL), rifampicin (200 μg/mL) and safranin O (200 μg/mL). Field isolates were tested only on media containing i-erythritol, rifampicin and thionin. Furthermore, each suspension was also inoculated on tryptose agar incubated in air, to test its ability to grow without CO 2 . Sensitivity to fuchsin was similar among reference strains evaluated. Growth of S19, 544 and 2308 but not RB51 were inhibited on media containing rifampicin. Medium with safranin O showed no inhibition for RB51, 544 and 2308, but it partially inhibited the S19 growth as well as medium containing i-erythritol. Treatment/control growth ratio for 2308 on tryptose agar containing thionin (2.5 μg/mL) was approximatelly 1.0, whereas S19 and RB51 showed 0.85 and 0.89 ratios, respectively. Growth of 544, S19 and RB51 but not 2308 was completely inhibited on medium with thionin (10 μg/mL). All field strains grew on medium containing i-erythritol, but were completelly inhibited by rifampicin. With exception of A1 ( B. abortus biovar 3) all field isolates grew on medium with thionin, although some strains showed a treatment/control growth ratio of 0.75–0.80 (10 μg/mL). These results showed that tryptose agar with thionin, i-erythritol or rifampicin could be useful for differentiating vaccine, challenge and field strains of B. abortus. PMID:26221116

  15. Different resistance patterns of reference and field strains of Brucella abortus.

    Science.gov (United States)

    Miranda, Karina L; Dorneles, Elaine M S; Poester, Fernando P; Martins Filho, Paulo S; Pauletti, Rebeca B; Lage, Andrey P

    2015-03-01

    The aim of this study was to evaluate the growth of the B. abortus reference strains and field isolates on media containing different inhibitor agents. Reference strains were seeded on tryptose agar containing: i-erythritol (1.0 mg/mL), fuchsin (20 μg/mL and 80 μg/mL), thionin (2.5 μg/mL and 10 μg/mL), rifampicin (200 μg/mL) and safranin O (200 μg/mL). Field isolates were tested only on media containing i-erythritol, rifampicin and thionin. Furthermore, each suspension was also inoculated on tryptose agar incubated in air, to test its ability to grow without CO 2 . Sensitivity to fuchsin was similar among reference strains evaluated. Growth of S19, 544 and 2308 but not RB51 were inhibited on media containing rifampicin. Medium with safranin O showed no inhibition for RB51, 544 and 2308, but it partially inhibited the S19 growth as well as medium containing i-erythritol. Treatment/control growth ratio for 2308 on tryptose agar containing thionin (2.5 μg/mL) was approximatelly 1.0, whereas S19 and RB51 showed 0.85 and 0.89 ratios, respectively. Growth of 544, S19 and RB51 but not 2308 was completely inhibited on medium with thionin (10 μg/mL). All field strains grew on medium containing i-erythritol, but were completelly inhibited by rifampicin. With exception of A1 ( B. abortus biovar 3) all field isolates grew on medium with thionin, although some strains showed a treatment/control growth ratio of 0.75-0.80 (10 μg/mL). These results showed that tryptose agar with thionin, i-erythritol or rifampicin could be useful for differentiating vaccine, challenge and field strains of B. abortus. PMID:26221116

  16. Optimizing the Measurement of Colostrum Antibody Concentrations for Identifying BVDV Persistently Infected Calves

    Directory of Open Access Journals (Sweden)

    Caitlin J. Jenvey

    2015-03-01

    Full Text Available Colostrum contains substantially higher concentrations of immunoglobulins compared to serum, which may help to improve the utility of diagnostic tests. The aim of this study was to determine the diagnostic value of colostrum antibody concentrations in identifying Bovine Viral Diarrhoea Virus (BVDV PI (persistently infected calf carrying beef heifers following an experimental infection. Colostrum was collected within 12 hours of parturition and tested in undiluted, 1:5, 1:10, 1:100, 1:200, and 1:500 dilutions using an enzyme-linked immunosorbent assay (ELISA for BVDV antibody. Cows were determined to be carrying a PI calf based on positive quantitative Real Time-Polymerase Chain Reaction and antigen ELISA result on pre-colostral serum and ear notch samples collected from their calf. The median ELISA sample-to-positive (S/P ratio for colostrum collected from heifers that carried a PI calf were significantly higher than the median ELISA S/P ratio for colostrum collected from heifers that did not carry a PI calf at dilutions of 1:100, 1:200, and 1:500. This study provides further evidence for increased antigenic stimulation in utero by the BVDV viraemic PI calf, which can also be identified with 100% diagnostic sensitivity when using 1:500 dilution colostrum.

  17. Bovine Viral Diarrhoea Virus (BVDV) in Dairy Cattle: A Matched Case-Control Study.

    Science.gov (United States)

    Machado, G; Egocheaga, R M F; Hein, H E; Miranda, I C S; Neto, W S; Almeida, L L; Canal, C W; Stein, M C; Corbellini, L G

    2016-02-01

    Bovine viral diarrhoea virus (BVDV) causes one of the most important diseases of cattle in terms of economic costs and welfare. The aims were to estimate herd prevalence and to investigate the factors associated with antibodies in bulk tank milk (BTM) in dairy herds through a matched case-control study. To estimate herd prevalence, BTM samples were randomly selected (n = 314) from a population (N = 1604). The true prevalence of BVDV was 24.3% (CI 95% = 20.1-29.3%). For the case-control study, BVDV antibody-positive herds (high antibody titres) were classified as cases (n = 21) and matched (n = 63) by milk production with herds presenting low antibody titres (ratio of 1 : 3). Three multivariable models were built: 1) full model, holding all 21 variables, and two models divided according to empirical knowledge and similarity among variables; 2) animal factor model; and 3) biosecurity model. The full model (model 1) identified: age as a culling criteria (OR = 0.10; CI 95% = 0.02-0.39; P cattle of neighbouring farms (OR = 5.78; CI 95% = 1.41-23.67; P = 0.04). We recommend the application of grouping predictors as a good choice for model building because it could lead to a better understanding of disease-exposure associations.

  18. Enterocytozoon bieneusi in Bovine Viral Diarrhea Virus (BVDV) infected and noninfected cattle herds.

    Science.gov (United States)

    Juránková, J; Kamler, M; Kovařčík, K; Koudela, B

    2013-02-01

    Enterocytozoon bieneusi known as a causative agent of opportunistic infections instigating diarrhoea in AIDS patients was identified also in a number of immunocompetent patients and in a wide range of animals, including cattle. In the present study we tested if the Bovine Viral Diarrhea Virus (BVDV), the most common pathogen underlying immunosuppressive Bovine Viral Diarrhoea (BVD), can enhance the occurrence of opportunistic infections with E. bieneusi in cattle. Six dairy farms were investigated using ELISA to detect antibodies against or antigens arising from BVDV in collected sera. A total of 240 individual faecal samples from four age groups were examined for the presence of E. bieneusi by nested PCR. Sequence analysis of six E. bieneusi positive samples revealed the presence of the genotype I of E. bieneusi, previously described in cattle. The hypothesis expecting higher prevalence of E. bieneusi in BVDV positive cattle herds was not confirmed in this study; however this is the first description about E. bieneusi in cattle in the Czech Republic.

  19. Computational study on electrical properties of transition metal dichalcogenide field-effect transistors with strained channel

    Energy Technology Data Exchange (ETDEWEB)

    Harada, Naoki; Sato, Shintaro; Yokoyama, Naoki [Collaborative Research Team Green Nanoelectronics Center, National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba, Ibaraki 305-8569 (Japan)

    2014-01-21

    The performance limits of monolayer transition metal dichalcogenide (TMDC) field-effect transistors (FETs) with isotropic biaxial strain were examined with the “top-of-the-barrier” ballistic MOSFET model. Using a first-principle theory, we calculated the band structures and density of states of strained monolayer MoS{sub 2} and WS{sub 2}, and used the results in model calculations. Introducing strain moves the positions of the conduction band minimum and valence band maximum in k-space with resultant variation in the effective mass and population of carriers. Introducing 2% tensile strain into n-type MoS{sub 2} FETs decreases the electron effective mass and, at the same time, increases energy separation between the lower and the higher valleys in the conduction band, resulting in 26% improvement of the ON current up to 1260 A/m. Whereas compressive strain results in complicated effects, −2% strain also improves the ON current by 15%. These results suggest that introducing artificial strain is promising to improve TMDC FET performance.

  20. High resolution monitoring of strain fields in concrete during hydraulic fracturing processes.

    Science.gov (United States)

    Chen, Rongzhang; Zaghloul, Mohamed A S; Yan, Aidong; Li, Shuo; Lu, Guanyi; Ames, Brandon C; Zolfaghari, Navid; Bunger, Andrew P; Li, Ming-Jun; Chen, Kevin P

    2016-02-22

    We present a distributed fiber optic sensing scheme to image 3D strain fields inside concrete blocks during laboratory-scale hydraulic fracturing. Strain fields were measured by optical fibers embedded during casting of the concrete blocks. The axial strain profile along the optical fiber was interrogated by the in-fiber Rayleigh backscattering with 1-cm spatial resolution using optical frequency domain reflectometry (OFDR). The 3D strain fields inside the cubes under various driving pressures and pumping schedules were measured and used to characterize the location, shape, and growth rate of the hydraulic fractures. The fiber optic sensor detection method presented in this paper provides scientists and engineers an unique laboratory tool to understand the hydraulic fracturing processes via internal, 3D strain measurements with the potential to ascertain mechanisms related to crack growth and its associated damage of the surrounding material as well as poromechanically-coupled mechanisms driven by fluid diffusion from the crack into the permeable matrix of concrete specimens. PMID:26907042

  1. High resolution monitoring of strain fields in concrete during hydraulic fracturing processes.

    Science.gov (United States)

    Chen, Rongzhang; Zaghloul, Mohamed A S; Yan, Aidong; Li, Shuo; Lu, Guanyi; Ames, Brandon C; Zolfaghari, Navid; Bunger, Andrew P; Li, Ming-Jun; Chen, Kevin P

    2016-02-22

    We present a distributed fiber optic sensing scheme to image 3D strain fields inside concrete blocks during laboratory-scale hydraulic fracturing. Strain fields were measured by optical fibers embedded during casting of the concrete blocks. The axial strain profile along the optical fiber was interrogated by the in-fiber Rayleigh backscattering with 1-cm spatial resolution using optical frequency domain reflectometry (OFDR). The 3D strain fields inside the cubes under various driving pressures and pumping schedules were measured and used to characterize the location, shape, and growth rate of the hydraulic fractures. The fiber optic sensor detection method presented in this paper provides scientists and engineers an unique laboratory tool to understand the hydraulic fracturing processes via internal, 3D strain measurements with the potential to ascertain mechanisms related to crack growth and its associated damage of the surrounding material as well as poromechanically-coupled mechanisms driven by fluid diffusion from the crack into the permeable matrix of concrete specimens.

  2. Giant electric-field-induced strain in lead-free piezoelectric materials.

    Science.gov (United States)

    Chen, Lan; Yang, Yurong; Meng, X K

    2016-05-03

    First-principles calculations are performed to investigate the structures, electrical, and magnetic properties of compressive BiFeO3 films under electric-field and pressure perpendicular to the films. A reversible electric-field-induced strain up 10% is achieved in the compressive BiFeO3 films. The giant strain originates from rhombohedral-tetragonal (R-T) phase transition under electric-filed, and is recoverable from tetragonal-rhombohedral (T-R) phase transition by compressive stress. Additionally, the weak ferromagnetism in BiFeO3 films is largely changed in R-T phase transition under electric-filed and T-R phase transition under pressure - reminiscent of magnetoelectric effect and magnetoelastic effect. These results suggest exciting device opportunities arising from the giant filed-induced strain, large magnetoelectric effect and magnetoelastic effect.

  3. Giant electric-field-induced strain in lead-free piezoelectric materials

    Science.gov (United States)

    Chen, Lan; Yang, Yurong; Meng, X. K.

    2016-01-01

    First-principles calculations are performed to investigate the structures, electrical, and magnetic properties of compressive BiFeO3 films under electric-field and pressure perpendicular to the films. A reversible electric-field-induced strain up 10% is achieved in the compressive BiFeO3 films. The giant strain originates from rhombohedral-tetragonal (R-T) phase transition under electric-filed, and is recoverable from tetragonal-rhombohedral (T-R) phase transition by compressive stress. Additionally, the weak ferromagnetism in BiFeO3 films is largely changed in R-T phase transition under electric-filed and T-R phase transition under pressure – reminiscent of magnetoelectric effect and magnetoelastic effect. These results suggest exciting device opportunities arising from the giant filed-induced strain, large magnetoelectric effect and magnetoelastic effect. PMID:27139526

  4. Note: Dynamic strain field mapping with synchrotron X-ray digital image correlation

    Energy Technology Data Exchange (ETDEWEB)

    Lu, L. [CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027 (China); The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610207 (China); Fan, D.; Luo, S. N., E-mail: sluo@pims.ac.cn [The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610207 (China); Bie, B. X. [The Peac Institute of Multiscale Sciences, Chengdu, Sichuan 610207 (China); School of Science, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Ran, X. X.; Qi, M. L., E-mail: qiml@whut.edu.cn [School of Science, Wuhan University of Technology, Wuhan, Hubei 430070 (China); Parab, N.; Sun, J. Z.; Liao, H. J.; Hudspeth, M. C.; Claus, B. [School of Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907 (United States); Fezzaa, K.; Sun, T. [Advanced Photon Source, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Chen, W. [School of Aeronautics and Astronautics, Purdue University, West Lafayette, Indiana 47907 (United States); School of Material Science Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Gong, X. L., E-mail: gongxl@ustc.edu.cn [CAS Key Laboratory of Mechanical Behavior and Design of Materials, Department of Modern Mechanics, University of Science and Technology of China, Hefei, Anhui 230027 (China)

    2014-07-15

    We present a dynamic strain field mapping method based on synchrotron X-ray digital image correlation (XDIC). Synchrotron X-ray sources are advantageous for imaging with exceptional spatial and temporal resolutions, and X-ray speckles can be produced either from surface roughness or internal inhomogeneities. Combining speckled X-ray imaging with DIC allows one to map strain fields with high resolutions. Based on experiments on void growth in Al and deformation of a granular material during Kolsky bar/gas gun loading at the Advanced Photon Source beamline 32ID, we demonstrate the feasibility of dynamic XDIC. XDIC is particularly useful for dynamic, in-volume, measurements on opaque materials under high strain-rate, large, deformation.

  5. Strain-Induced Pseudo--Magnetic Fields in Graphene: MegaGauss in Nanobubbles

    Science.gov (United States)

    Levy, Niv

    2011-03-01

    Recent theoretical proposals suggest that strain can be used to modify graphene electronic states through the creation of a pseudo--magnetic field. This effect is unique to graphene because of its massless Dirac fermion-like band structure and particular lattice symmetry (C3v). Scanning tunneling microscopy shows that graphene grown on a platinum (111) surface forms nanobubbles, which are highly strained due to thermal expansion mismatch between the film and the substrate. We find that scanning tunneling spectroscopy measurements of these nanobubbles exhibit Landau levels that form in the presence of strain-induced pseudo--magnetic fields greater than 300 Tesla. This demonstration of enormous pseudo--magnetic fields opens the door to both the study of charge carriers in previously inaccessible high magnetic field regimes and deliberate mechanical control over electronic structure in graphene or so-called ``strain engineering''. In collaboration with S. A. Burke ,2 , K. L. Meaker 2 , M. Panlasigui 2 , A. Zettl 2,3 , F. Guinea 4 , A. H. Castro Neto 5 and M. F. Crommie 2,3 . 1. Present address: Department of Physics and Astronomy and Department of Chemistry, University of British Columbia, Vancouver, BC V6T 121, Canada. 2. Department of Physics, University of California, Berkeley, CA 94720, USA. 3. Materials Science Division, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA. 4. Instituto de Ciencia de Materiales de Madrid (CSIC), Madrid 28049, Spain. 5. Department of Physics, Boston University, Boston, MA 02215, USA.

  6. Effect of Agave tequilana age, cultivation field location and yeast strain on tequila fermentation process.

    Science.gov (United States)

    Pinal, L; Cornejo, E; Arellano, M; Herrera, E; Nuñez, L; Arrizon, J; Gschaedler, A

    2009-05-01

    The effect of yeast strain, the agave age and the cultivation field location of agave were evaluated using kinetic parameters and volatile compound production in the tequila fermentation process. Fermentations were carried out with Agave juice obtained from two cultivation fields (CF1 and CF2), as well as two ages (4 and 8 years) and two Saccharomyces cerevisiae yeast strains (GU3 and AR5) isolated from tequila fermentation must. Sugar consumption and ethanol production varied as a function of cultivation field and agave age. The production of ethyl acetate, 1-propanol, isobutanol and amyl alcohols were influenced in varying degrees by yeast strain, agave age and cultivation field. Methanol production was only affected by the agave age and 2-phenylethanol was influenced only by yeast strain. This work showed that the use of younger Agave tequilana for tequila fermentation resulted in differences in sugar consumption, ethanol and volatile compounds production at the end of fermentation, which could affect the sensory quality of the final product.

  7. Isolation of recombinant field strains of Marek's disease virus integrated with reticuloendotheliosis virus genome fragments

    Institute of Scientific and Technical Information of China (English)

    ZHANG; Zhi; CUI; Zhizhong

    2005-01-01

    Two Marek's disease virus (MDV) field strains were isolated from chickens with tumors independently from Guangdong and Guangxi provinces, and it was confirmed that there were no co-infections with reticuloendotheliosis viruses (REV) in chicken embryo fibroblast cells (CEF) in indirect fluorescence antibody test (IFA) with REV-specific monoclonal antibodies. By dot blot hybridization and PCR of genomic DNA of MDV-infected CEF, it was indicated that LTR fragments of REV genome were integrated into genome of these two MDV field strains. To amplify and clone the integrated REV LTR with MDV sequence at the junction, 4 primers from REV LTR and 7 primers from MDV genome fragment with REV LTR insertion hot points were synthesized and 28 (4x7) pairs of primers (one from REV and another from MDV for each pair) were used in PCR while using the genomic DNA of both strains as the templates. The sequence data demonstrated that both recombinant field strains contained the same REV LTR inserted into MDV at the identical sites in US fragment of the genomes. From the above, it was speculated that both recombinant field MDVs were originated from a same recombinant virus and spread among chicken flocks in two provinces.

  8. Surface strain-field determination of tympanic membrane using 3D-digital holographic interferometry

    Science.gov (United States)

    Hernandez-Montes, María del S.; Mendoza Santoyo, Fernando; Muñoz, Silvino; Perez, Carlos; de la Torre, Manuel; Flores, Mauricio; Alvarez, Luis

    2015-08-01

    In order to increase the understanding of soft tissues mechanical properties, 3D Digital Holographic Interferometry (3D-DHI) was used to quantify the strain-field on a cat tympanic membrane (TM) surface. The experiments were carried out applying a constant sound-stimuli pressure of 90 dB SPL (0.632 Pa) on the TM at 1.2 kHz. The technique allows the accurate acquisition of the micro-displacement data along the x, y and z directions, which is a must for a full characterization of the tissue mechanical behavior under load, and for the calculation of the strain-field in situ. The displacements repeatability in z direction shows a standard deviation of 0.062 μm at 95% confidence level. In order to realize the full 3D characterization correctly the contour of the TM surface was measured employing the optically non-contact two-illumination positions contouring method. The x, y and z displacements combined with the TM contour data allow the evaluation its strain-field by spatially differentiating the u(m,n), v(m,n), and w(m,n) deformation components. The accurate and correct determination of the TM strain-field leads to describing its elasticity, which is an important parameter needed to improve ear biomechanics studies, audition processes and TM mobility in both experimental measurements and theoretical analysis of ear functionality and its modeling.

  9. Simulation-based design of a strained graphene field effect transistor incorporating the pseudo magnetic field effect

    Energy Technology Data Exchange (ETDEWEB)

    Souma, Satofumi, E-mail: ssouma@harbor.kobe-u.ac.jp; Ueyama, Masayuki; Ogawa, Matsuto [Department of Electrical and Electronic Engineering, Kobe University, 1-1 Rokkodai, Nada, Kobe 657-8501 (Japan)

    2014-05-26

    We present a numerical study on the performance of strained graphene-based field-effect transistors. A local strain less than 10% is applied over a central channel region of the graphene to induce the shift of the Dirac point in the channel region along the transverse momentum direction. The left and the right unstrained graphene regions are doped to be either n-type or p-type. By using the atomistic tight-binding model and a Green's function method, we predict that the gate voltage applied to the central strained graphene region can switch the drain current on and off with an on/off ratio of more than six orders of magnitude at room temperature. This is in spite of the absence of a bandgap in the strained channel region. Steeper subthreshold slopes below 60 mV/decade are also predicted at room temperature because of a mechanism similar to the band-to-band tunneling field-effect transistors.

  10. Effect of external stress and bias magnetic field on transformation strain of heusler alloy Ni-Mn-Ga

    Institute of Scientific and Technical Information of China (English)

    高智勇; 蔡伟; 赵连城; 吴光恒; 陈京兰; 詹文山

    2003-01-01

    The influence of external field(magnetic field and stress field) on the transformation strain of Ni52.9-Mn24.4Ga22.7 single crystal were investigated and its mechanism was also discussed. When thermally martensitictransformation occurs, about 0.25% transformation strain is obtained which may be obviously enhanced to about0. 8% by a 6 000 Oe magnetic bias field. However, the strain decreases by the external compress stress loaded alongthe strain-measured direction. When the external compress stress and bias magnetic field are simultaneously applied,the transformation strain decreases with increasing the magnetic field, which is related to the rearrangement of themartensite variants influenced by the external field.

  11. Perfil da infecção pelo vírus da diarreia viral bovina (BVDV em um rebanho bovino leiteiro de alta produção e com programa de vacinação contra o BVDV Bovine viral diarrhea virus (BVDV infection profile in a high production dairy herd with vaccination program against BVDV

    Directory of Open Access Journals (Sweden)

    Stelamaris Dezen

    2013-02-01

    Full Text Available A infecção pelo vírus da diarreia viral bovina (BVDV foi avaliada em um rebanho bovino leiteiro de alta produção com histórico de problemas reprodutivos e de vacinação regular contra o BVDV. A identificação do vírus foi realizada por RT-PCR em soro sanguíneo e o perfil sorológico por vírus-neutralização. Inicialmente, 100% (n=692 dos animais do rebanho foram avaliados com relação à presença de infecção ativa pelo BVDV por meio da RT-PCR. Quatro meses após, todos os animais positivos (n=29 na primeira avaliação foram avaliados novamente pela RT-PCR, assim como todos os animais que nasceram (n=72 e os que apresentaram problemas reprodutivos (n=36 no intervalo entre a primeira e a segunda colheita de sangue. Os resultados finais do estudo possibilitaram identificar 27 animais transitoriamente infectados e três animais persistentemente infectados (PI. A sorologia, realizada apenas nos animais positivos na primeira avaliação pela RT-PCR e nas vacas que apresentaram problemas reprodutivos entre a primeira e a segunda RT-PCR, demonstrou grande flutuação nos títulos de anticorpos neutralizantes, além de soroconversão na maioria dos animais. Foram identificados aumentos nos títulos de anticorpos neutralizantes que variaram entre 3 e 8 log2, indicando infecção ativa no rebanho. A circulação viral no rebanho avaliado foi responsável pela expressão de sinais clínicos da esfera reprodutiva em animais com baixo título de anticorpos e consequente falha na proteção fetal. Os resultados demonstram que o controle da infecção pelo BVDV apenas por meio da vacinação regular em rebanhos com animais PI pode não ser eficaz na profilaxia dessa virose.The profile of bovine viral diarrhea virus (BVDV infection was studies in a high production dairy herd selected based on a history of reproductive failures and regular vaccination against BVDV. Virus identification was performed by RT-PCR and serological profile was

  12. Crack-tip strain field mapping and the toughness of metallic glasses.

    Directory of Open Access Journals (Sweden)

    Todd C Hufnagel

    Full Text Available We have used high-energy x-ray scattering to map the strain fields around crack tips in fracture specimens of a bulk metallic glass under load at room temperature and below. From the measured strain fields we can calculate the components of the stress tensor as a function of position and determine the size and shape of the plastic process zone around the crack tip. Specimens tested at room temperature develop substantial plastic zones and achieve high stress intensities ((K(If = 76 MPa m(1/2 prior to fracture. Specimens tested at cryogenic temperatures fail at reduced but still substantial stress intensities (K(If = 39 MPa m(1/2 and show only limited evidence of crack-tip plasticity. We propose that the difference in behavior is associated with changes in the flow stress and elastic constants, which influence the number density of shear bands in the plastic zone and thus the strain required to initiate fracture on an individual band. A secondary effect is a change in the triaxial state of stress around the crack tip due to the temperature dependence of Poisson's ratio. It is likely that this ability to map elastic strains on the microscale will be useful in other contexts, although interpreting shifts in the position of the scattering peaks in amorphous materials in terms of elastic strains must be done with caution.

  13. Transplacental transmission of field and rescued strains of BTV-2 and BTV-8 in experimentally infected sheep

    DEFF Research Database (Denmark)

    Rasmussen, Lasse Dam; Savini, Giovanni; Lorusso, Alessio;

    2013-01-01

    Transplacental transmission of bluetongue virus has been shown previously for the North European strain of serotype 8 (BTV-8) and for tissue culture or chicken egg-adapted vaccine strains but not for field strains of other serotypes. In this study, pregnant ewes (6 per group) were inoculated with...... against the different BTV strains used in this study. BTV RNA was detectable in the blood of all but two ewes for over 28 days but infectious virus could only be detected in the blood for a much shorter period. Interestingly, transplacental transmission of BTV-2 (both field and rescued strains) was...

  14. Dark-field electron holography for the mapping of strain in nanostructures: correcting artefacts and aberrations

    International Nuclear Information System (INIS)

    We present details of the new electron holographic dark-field technique (HoloDark) for mapping strain in nanostructures. A diffracted beam emanating from an unstrained region of crystal is interfered (with the aid of an electrostatic biprism) with a diffracted beam from the strained region of interest. Geometric phase analysis (GPA) of the holographic fringes determines the relative deformation of the two crystalline lattices. Strain can be measured to high precision, with nanometre spatial resolution and for micron fields of view. Experiments are carried out on the SACTEM-Toulouse, a Tecnai F20 (FEI) equipped with imaging aberration corrector (CEOS), field-emission gun and rotatable biprism (FEI). We operate the microscope in free-lens control with the main objective lens switched off and using the corrector transfer lenses as a Lorentz lens. We will present measurements of strain in test nanostructures and show how artefacts from thickness variations can be removed. Finally, we show our first results using a recently developed aberration-corrected Lorentz mode (CEOS).

  15. Tuning the energy gap of bilayer α-graphyne by applying strain and electric field

    Science.gov (United States)

    Yang, Hang; Wu, Wen-Zhi; Jin, Yu; Wan-Lin, Guo

    2016-02-01

    Our density functional theory calculations show that the energy gap of bilayer α-graphyne can be modulated by a vertically applied electric field and interlayer strain. Like bilayer graphene, the bilayer α-graphyne has electronic properties that are hardly changed under purely mechanical strain, while an external electric field can open the gap up to 120 meV. It is of special interest that compressive strain can further enlarge the field induced gap up to 160 meV, while tensile strain reduces the gap. We attribute the gap variation to the novel interlayer charge redistribution between bilayer α-graphynes. These findings shed light on the modulation of Dirac cone structures and potential applications of graphyne in mechanical-electric devices. Project supported by the National Key Basic Research Program of China (Grant Nos. 2013CB932604 and 2012CB933403), the National Natural Science Foundation of China (Grant Nos. 51472117 and 51535005), the Research Fund of State Key Laboratory of Mechanics and Control of Mechanical Structures, China (Grant No. 0414K01), the Nanjing University of Aeronautics and Astronautics (NUAA) Fundamental Research Funds, China (Grant No. NP2015203), and the Priority Academic Program Development of Jiangsu Higher Education Institutions.

  16. Dark-field electron holography for the mapping of strain in nanostructures: correcting artefacts and aberrations

    Energy Technology Data Exchange (ETDEWEB)

    Hytch, M J; Houdellier, F; Snoeck, E; Huee, F, E-mail: hytch@cemes.f [CEMES-CNRS, 29 rue Jeanne Marvig, 31055 Toulouse (France)

    2010-07-01

    We present details of the new electron holographic dark-field technique (HoloDark) for mapping strain in nanostructures. A diffracted beam emanating from an unstrained region of crystal is interfered (with the aid of an electrostatic biprism) with a diffracted beam from the strained region of interest. Geometric phase analysis (GPA) of the holographic fringes determines the relative deformation of the two crystalline lattices. Strain can be measured to high precision, with nanometre spatial resolution and for micron fields of view. Experiments are carried out on the SACTEM-Toulouse, a Tecnai F20 (FEI) equipped with imaging aberration corrector (CEOS), field-emission gun and rotatable biprism (FEI). We operate the microscope in free-lens control with the main objective lens switched off and using the corrector transfer lenses as a Lorentz lens. We will present measurements of strain in test nanostructures and show how artefacts from thickness variations can be removed. Finally, we show our first results using a recently developed aberration-corrected Lorentz mode (CEOS).

  17. Genetic characterization of Italian field strains of Schmallenberg virus based on N and NSs genes.

    Science.gov (United States)

    Izzo, Francesca; Cosseddu, Gian Mario; Polci, Andrea; Iapaolo, Federica; Pinoni, Chiara; Capobianco Dondona, Andrea; Valleriani, Fabrizia; Monaco, Federica

    2016-08-01

    Following its first identification in Germany in 2011, the Schmallenberg virus (SBV) has rapidly spread to many other European countries. Despite the wide dissemination, the molecular characterization of the circulating strains is limited to German, Belgian, Dutch, and Swiss viruses. To fill this gap, partial genetic characterization of 15 Italian field strains was performed, based on S segment genes. Samples were collected in 2012 in two different regions where outbreaks occurred during distinct epidemic seasons. The comparative sequence analysis demonstrated a high molecular stability of the circulating viruses; nevertheless, we identified several variants of the N and NSs proteins not described in other SBV isolates circulating in Europe. PMID:27059241

  18. MoS2/MX2 heterobilayers: bandgap engineering via tensile strain or external electrical field

    Science.gov (United States)

    Lu, Ning; Guo, Hongyan; Li, Lei; Dai, Jun; Wang, Lu; Mei, Wai-Ning; Wu, Xiaojun; Zeng, Xiao Cheng

    2014-02-01

    We have performed a comprehensive first-principles study of the electronic and magnetic properties of two-dimensional (2D) transition-metal dichalcogenide (TMD) heterobilayers MX2/MoS2 (M = Mo, Cr, W, Fe, V; X = S, Se). For M = Mo, Cr, W; X = S, Se, all heterobilayers show semiconducting characteristics with an indirect bandgap with the exception of the WSe2/MoS2 heterobilayer which retains the direct-bandgap character of the constituent monolayer. For M = Fe, V; X = S, Se, the MX2/MoS2 heterobilayers exhibit metallic characters. Particular attention of this study has been focused on engineering the bandgap of the TMD heterobilayer materials via application of either a tensile strain or an external electric field. We find that with increasing either the biaxial or uniaxial tensile strain, the MX2/MoS2 (M = Mo, Cr, W; X = S, Se) heterobilayers can undergo a semiconductor-to-metal transition. For the WSe2/MoS2 heterobilayer, a direct-to-indirect bandgap transition may occur beyond a critical biaxial or uniaxial strain. For M (=Fe, V) and X (=S, Se), the magnetic moments of both metal and chalcogen atoms are enhanced when the MX2/MoS2 heterobilayers are under a biaxial tensile strain. Moreover, the bandgap of MX2/MoS2 (M = Mo, Cr, W; X = S, Se) heterobilayers can be reduced by the vertical electric field. For two heterobilayers MSe2/MoS2 (M = Mo, Cr), PBE calculations suggest that the indirect-to-direct bandgap transition may occur under an external electric field. The transition is attributed to the enhanced spontaneous polarization. The tunable bandgaps in general and possible indirect-direct bandgap transitions due to tensile strain or external electric field make the TMD heterobilayer materials a viable candidate for optoelectronic applications.We have performed a comprehensive first-principles study of the electronic and magnetic properties of two-dimensional (2D) transition-metal dichalcogenide (TMD) heterobilayers MX2/MoS2 (M = Mo, Cr, W, Fe, V; X = S, Se). For

  19. Interaction of radiation damage with strain field around. cap alpha. -precipitates in electron-irradiated. beta. -Nb-Zr alloys

    Energy Technology Data Exchange (ETDEWEB)

    Nakai, K.; Kinoshita, C.; Kitajima, S.; Muroo, Y. (Kyushu Univ., Fukuoka (Japan). Dept. of Nuclear Engineering)

    1985-05-01

    The strain field around ..cap alpha..-precipitates (hcp) in the ..beta..-Nb-Zr phase has been evaluated to study its relaxation mechanism during electron irradiation in a high voltage electron microscope. The crystallography of the ..cap alpha..-precipitates is determined to be of Burgers' orientation relationship with the ..beta..-phase. The compressive strain field around the ..cap alpha..-precipitates is detected and determined by use of the strain contrast of electron microscopy and the elastic continuum theory. The relaxation process of the strain field around the ..cap alpha..-precipitates is observed during electron irradiation, and is analyzed in terms of accumulation of vacancies.

  20. Molecular typing of Leptospira spp. strains isolated from field mice confirms a link to human leptospirosis.

    Science.gov (United States)

    Li, S J; Wang, D M; Zhang, C C; Li, X W; Yang, H M; Tian, K C; Wei, X Y; Liu, Y; Tang, G P; Jiang, X G; Yan, J

    2013-11-01

    In recent years, human leptospirosis has been reported in Jinping and Liping counties, Guizhou province, but the leptospires have never been isolated. To track the source of infection and understand the aetiological characteristics, we performed surveillance for field mice carriage of leptospirosis in 2011. Four strains of leptospire were isolated from Apodemus agrarius. PCR confirmed the four isolates as pathogenic. Multiple-locus variable-number tandem repeat analysis (MLVA) showed that the four strains were closely related to serovar Lai strain 56601 belonging to serogroup Icterohaemorrhagiae, which is consistent with the antibody detection results from local patients. Furthermore, the diversity of leptospiral isolates from different hosts and regions was demonstrated with MLVA. Our results suggest that A. agrarius may be the main carrier of Leptospira in Jinping and Liping counties, and the serogroup Icterohaemorrhagiae serovar may be the epidemic serogroup of Leptospira. This will contribute to the control and prevention of leptospirosis in these localities. PMID:23406882

  1. Assessing Static Performance of the Dashengguan Yangtze Bridge by Monitoring the Correlation between Temperature Field and Its Static Strains

    OpenAIRE

    Gao-Xin Wang; You-Liang Ding; Peng Sun; Lai-Li Wu; Qing Yue

    2015-01-01

    Taking advantage of the structural health monitoring system installed on the steel truss arch girder of Dashengguan Yangtze Bridge, the temperature field data and static strain data are collected and analyzed for the static performance assessment of the bridge. Through analysis, it is found that the static strain changes are mainly caused by temperature field (temperature and temperature difference) and train. After the train-induced static strains are removed, the correlation between the rem...

  2. Modelling the spread of bovine viral diarrhea virus (BVDV) in a beef cattle herd and its impact on herd productivity.

    Science.gov (United States)

    Damman, Alix; Viet, Anne-France; Arnoux, Sandie; Guerrier-Chatellet, Marie-Claude; Petit, Etienne; Ezanno, Pauline

    2015-02-24

    Bovine viral diarrhea virus (BVDV) is a common pathogen of cattle herds that causes economic losses due to reproductive disorders in breeding cattle and increased morbidity and mortality amongst infected calves. Our objective was to evaluate the impact of BVDV spread on the productivity of a beef cow-calf herd using a stochastic model in discrete time that accounted for (1) the difference in transmission rates when animals are housed indoors versus grazing on pasture, (2) the external risk of disease introductions through fenceline contact with neighboring herds and the purchase of infected cattle, and (3) the risk of individual pregnant cattle generating persistently infected (PI) calves based on their stage in gestation. The model predicted the highest losses from BVDV during the first 3 years after disease was introduced into a naive herd. During the endemic phase, the impact of BVDV on the yearly herd productivity was much lower due to herd immunity. However, cumulative losses over 10 years in an endemic situation greatly surpassed the losses that occurred during the acute phase. A sensitivity analysis of key model parameters revealed that herd size, the duration of breeding, grazing, and selling periods, renewal rate of breeding females, and the level of numerical productivity expected by the farmer had a significant influence on the predicted losses. This model provides a valuable framework for evaluating the impact of BVDV and the efficacy of different control strategies in beef cow-calf herds.

  3. Extracting full-field dynamic strain response of a rotating wind turbine using photogrammetry

    Science.gov (United States)

    Baqersad, Javad; Poozesh, Peyman; Niezrecki, Christopher; Avitabile, Peter

    2015-04-01

    Health monitoring of wind turbines is typically performed using conventional sensors (e.g. strain-gages and accelerometers) that are usually mounted to the nacelle or gearbox. Although many wind turbines stop operating due to blade failures, there are typically few to no sensor mounted on the blades. Placing sensors on the rotating parts of the structure is a challenge due to the wiring and data transmission constraints. Within the current work, an approach to monitor full-field dynamic response of rotating structures (e.g. wind turbine blades or helicopter rotors) is developed and experimentally verified. A wind turbine rotor was used as the test structure and was mounted to a block and horizontally placed on the ground. A pair of bearings connected to the rotor shaft allowed the turbine to freely spin along the shaft. Several optical targets were mounted to the blades and a pair of high-speed cameras was used to monitor the dynamics of the spinning turbine. Displacements of the targets during rotation were measured using three-dimensional point tracking. The point tracking technique measured both rigid body displacement and flexible deformation of the blades at target locations. While the structure is rotating, only flap displacements of optical targets (displacements out of the rotation plane) were used in strain prediction process. The measured displacements were expanded and applied to the finite element model of the turbine to extract full-field dynamic strain on the structure. The proposed approach enabled the prediction of dynamic response on the outer surface as well as within the inner points of the structure where no other sensor could be easily mounted. In order to validate the proposed approach, the predicted strain was compared to strain measured at four locations on the spinning blades using a wireless strain-gage system.

  4. Strain measurement with high-temperature strain gauges in a non steady temperature field considering a two dimensional strain field; Dehnungsmessung mit Hochtemperatur-Dehnungsmessstreifen im instationaeren Temperaturfeld unter Beruecksichtigung eines zweiachsigen Dehnungszustandes

    Energy Technology Data Exchange (ETDEWEB)

    Merz, M. [Fachgebiet Maschinenelemente und Maschinenakustik, Technische Hochschule Darmstadt (Germany)

    1995-04-01

    To confirm a FEM-simulation the strain fields at the surface of the hub of a shrink fit are measured during the thermal fitting process. The temperature changes during the fitting process between 420 C and 20 C. Because of the rotation symmetry a two dimensional strain field yields on the surface of the hub. The strain gauge type LF 30 is used. The temperature-dependence could not compensate in a half-bridge compensation-circuit. Because of this each strain gauge application must be calibrated individually. The experimental data is extremely close to the results predicted by the numerical simulation. This is an experimental confirmation of the FEM-simulation. (orig.) [Deutsch] Mit dem Ziel einer experimentellen Verifikation einer FEM-Simulation soll das Dehnungsfeld an der Nabenoberflaeche beim thermischen Fuegen von Pressverbindungen gemessen werden. Waehrend der Dehnungsmessung wird an der Messstelle der Temperaturbereich 420 C bis 20 C durchlaufen. Aufgrund der Rotationssymmetrie liegt an der Nabenoberflaeche ein zweiachsiges Dehnungsfeld vor. Zur Messung werden Hochtemperatur-Dehnungsmessstreifen (HT-DMS) vom Typ LF 30 eingesetzt. Der Temperaturgang kann wegen der Messaufgabe schaltungstechnisch nicht kompensiert werden. Deshalb wird fuer jede DMS-Applikation eine individuelle Kalibrierung durchgefuehrt. Abschliessend werden die Messergebnisse mit Werten verglichen, die mit einer den Fuegevorgang simulierenden FEM-Rechnung ermittelt werden. Es werden grosse Uebereinstimmungen zwischen den gemessenen und berechneten Werten erzielt. Damit liegt ein experimenteller Nachweis der FEM-Simulation vor. (orig.)

  5. Molecular Typing of Acinetobacter Baumannii Clinical Strains in Tehran by Pulsed-Field Gel Electrophoresis

    Directory of Open Access Journals (Sweden)

    Neda Farahani

    2013-03-01

    Full Text Available Background & Objective : Currently, Acinetobacter baumannii is an important nosocomial pathogen insofar as its hospital outbreaks have been described from various geographical areas. Since the discrimination of strains within a species is important for delineating nosocomial outbreaks, this study was conducted with the aim of genotyping the A. baumannii clinical strains in Tehran via the pulsed-field gel electrophoresis (PFGE method, which is the most accurate method used for the typing of bacterial species.   Materials & methods: This study was performed on 70 isolates of acinetobacter baumannii isolated from patients from Baqiyatallah, Rasoole Akram, and Milad hospitals in Tehran. Cultural and biochemical methods were used for the identification of the isolates in species level, and then susceptibility tests were carried out on 50 isolates of A. baumannii using the disk diffusion method. The PFGE method was performed on the isolates by Apa I restriction enzyme. Finally, the results of the PFGE were analyzed. Result: Acinetobacter baumannii strains isolated from hospitals in Tehran showed seven different genetic patterns, two of which were sporadic . Also, genotypic profiles were different in each hospital, and different patterns of genetic resistance to common antibiotics were observed. Conclusion: A lthough diversity was observed among the strains of A. baumannii by the PFGE method in Tehran, no epidemic strains were found among them.  

  6. On the Decomposition of the Spacetime Metric Tensor and of Tensor Fields in Strained Spacetime

    Directory of Open Access Journals (Sweden)

    Millette P. A.

    2012-10-01

    Full Text Available We propose a natural decomposition of the spacetime metric tensor of General Relativ- ity into a background and a dynamical part based on an analysis from first principles of the effect of a test mass on the background metric. We find that the presence of mass results in strains in the spacetime continuum. Those strains correspond to the dy- namical part of the spacetime metric tensor. We then apply the stress-strain relation of Continuum Mechanics to the spacetime continuum to show that rest-mass energy den- sity arises from the volume dilatation of the spacetime continuum. Finally we propose a natural decomposition of tensor fields in strained spacetime, in terms of dilatations and distortions. We show that dilatations correspond to rest-mass energy density, while distortions correspond to massless shear transverse waves. We note that this decom- position in a massive dilatation and a massless transverse wave distortion, where both are present in spacetime continuum deformations, is somewhat reminiscent of wave- particle duality. We note that these results are considered to be local effects in the particular reference frame of the observer. In addition, the applicability of the proposed metric to the Einstein field equations remains open.

  7. GPS Velocity and Strain Rate Fields in Southwest Anatolia from Repeated GPS Measurements

    Directory of Open Access Journals (Sweden)

    Saffet Erdoğan

    2009-03-01

    Full Text Available Southwestern Turkey is a tectonically active area. To determine kinematics and strain distribution in this region, a GPS network of sixteen stations was established. We have used GPS velocity field data for southwest Anatolia from continuous measurements covering the period 2003 to 2006 to estimate current crustal deformation of this tectonically active region. GPS data were processed using GAMIT/GLOBK software and velocity and strain rate fields were estimated in the study area. The measurements showed velocities of 15-30 mm/yr toward the southwest and strain values up to 0.28-8.23x10-8. Results showed that extension has been determined in the Burdur-Isparta region. In this study, all of strain data reveal an extensional neotectonic regime through the northeast edge of the Isparta Angle despite the previously reported compressional neotectonic regime. Meanwhile, results showed some small differences relatively with the 2006 model of Reilinger et al. As a result, active tectonic movements, in agreement with earthquake fault plane solutions showed important activity.

  8. GPS Velocity and Strain Rate Fields in Southwest Anatolia from Repeated GPS Measurements.

    Science.gov (United States)

    Erdoğan, Saffet; Sahin, Muhammed; Tiryakioğlu, Ibrahim; Gülal, Engin; Telli, Ali Kazım

    2009-01-01

    Southwestern Turkey is a tectonically active area. To determine kinematics and strain distribution in this region, a GPS network of sixteen stations was established. We have used GPS velocity field data for southwest Anatolia from continuous measurements covering the period 2003 to 2006 to estimate current crustal deformation of this tectonically active region. GPS data were processed using GAMIT/GLOBK software and velocity and strain rate fields were estimated in the study area. The measurements showed velocities of 15-30 mm/yr toward the southwest and strain values up to 0.28-8.23×10(-8). Results showed that extension has been determined in the Burdur-Isparta region. In this study, all of strain data reveal an extensional neotectonic regime through the northeast edge of the Isparta Angle despite the previously reported compressional neotectonic regime. Meanwhile, results showed some small differences relatively with the 2006 model of Reilinger et al. As a result, active tectonic movements, in agreement with earthquake fault plane solutions showed important activity. PMID:22573998

  9. Establishment of a nanoparticle-assisted RT-PCR assay to distinguish field strains and attenuated strains of porcine epidemic diarrhea virus.

    Science.gov (United States)

    Zhu, Yu; Wang, Gui-Hua; Cui, Yu-Dong; Cui, Shang-Jin

    2016-09-01

    Porcine epidemic diarrhea virus (PEDV) can cause serious disease and even death in neonatal piglets, resulting in serious damage to the swine industry worldwide. Open reading frame 3 (ORF3) is the only accessory gene in the PEDV genome. Previous studies have indicated that PEDV vaccine strains have a partial deletion in ORF3. In this study, a nanoparticle-assisted polymerase chain reaction (nanoparticle-assisted RT-PCR) assay targeting the ORF3 of PEDV was developed to distinguish PEDV field strains from attenuated strains by using a specific pair of primers. The PCR products of field strains and attenuated strains were 264 bp and 215 bp in length, respectively. The sensitivity and specificity of this assay were also assessed. The nanoparticle-assisted RT-PCR assay was 10-100 times more sensitive than the conventional RT-PCR assay, with no cross-reactions when amplifying porcine pseudorabies virus (PRV), porcine circovirus type 2 (PCV2), classical swine fever virus (CSFV), porcine parvovirus (PPV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine rotavirus (RV), and porcine transmissible gastroenteritis virus (TGEV). The nanoparticle-assisted RT-PCR assay we describe here can be used to distinguish field strains from vaccine strains of PEDV, and it shows promise for reducing economic loss due to PEDV infection. PMID:27287433

  10. Evaluation for Small Visual Difference Between Conforming Meshes on Strain Field

    Institute of Scientific and Technical Information of China (English)

    Zhe Bian; Shi-Min Hu; Ralph R. Martin

    2009-01-01

    This paper gives a method of quantifying small visual differences between 3D mesh models with conforming topology, based on the theory of strain fields. Strain field is a geometric quantity in elasticity which is used to describe the deformation of elastomer. In this paper we consider the 3D models as objects with elasticity. The further demonstrations are provided: the first is intended to give the reader a visual impression of how our measure works in practice; and the second is to give readers a visual impression of how our measure works in evaluating filter algorithms. Our experiments show that our difference estimates are well correlated with human perception of differences. This work has applications in the evaluation of 3D mesh watermarking, 3D mesh compression reconstruction, and 3D mesh filtering.

  11. Novel simulation method for fiber Bragg grating under inhomogeneous strain fields

    Institute of Scientific and Technical Information of China (English)

    YUN Bin-feng; LU Chang-gui; WANG Zhu-yuan; WANG Yi-ping; CUI Yi-ping

    2005-01-01

    The spectra of fiber Bragg grating (FBG) in inhomogeneous strain fields are distorted due to its inhomogeneity of both the periods and the effective refractive index. The couple mode theory and the Runge-Kutta method can be employed for exact simulation of the spectrum of Bragg grating in such field, but the convergence speed is slow. On the other hand, although the transfer matrix method could be used with higher convergence speed, the precision is poor because of the neglect of the grads of strain change. By improving the FBG equivalent period, a novel simulation method based on a modified transfer matrix method is proposed, which has the advantage of quick-convergence as well as good accuracy.

  12. Hydrogen Concentration and Strain Fields Near Fatigue Cracks in Pipeline Steel Measured Via Neutron Imaging

    Science.gov (United States)

    Connolly, Matthew; Slifka, Andrew; Drexler, Elizabeth; Hydrogen Pipeline Safety Team

    Hydrogen (H2) is desirable for energy storage as it is cleaner burning and can store a larger amount of energy than an equal mass of gasoline. One problem in the development of a hydrogen economy is to find or develop materials that ensure the safe, reliable, and cost-effective flow of energy from the source to the user. It is expected steels will be needed to serve this function. However, the existing network of natural gas pipeline, for example, is constructed of ferrous materials which are susceptible to embrittlement and subsequent increased fatigue crack growth rates after exposure to hydrogen. In order to improve current modeling efforts, experimental determination of hydrogen concentration, hydrogen diffusion rates, and strain fields are required to inform and validate the model. Here we report neutron imaging measurements of the hydrogen concentration near a fatigue crack and the corresponding strain field, measured via neutron transmission Bragg edge spectroscopy. Nist Materials Measurement Laboratory, Applied Chemicals and Materials Division.

  13. A phase-field model for ductile fracture at finite strains and its experimental verification

    Science.gov (United States)

    Ambati, Marreddy; Kruse, Roland; De Lorenzis, Laura

    2016-01-01

    In this paper, a phase-field model for ductile fracture previously proposed in the kinematically linear regime is extended to the three-dimensional finite strain setting, and its predictions are qualitatively and quantitatively compared with several experimental results, both from ad-hoc tests carried out by the authors and from the available literature. The proposed model is based on the physical assumption that fracture occurs when a scalar measure of the accumulated plastic strain reaches a critical value, and such assumption is introduced through the dependency of the phase-field degradation function on this scalar measure. The proposed model is able to capture the experimentally observed sequence of elasto-plastic deformation, necking and fracture phenomena in flat specimens; the occurrence of cup-and-cone fracture patterns in axisymmetric specimens; the role played by notches and by their size on the measured displacement at fracture; and the sequence of distinct cracking events observed in more complex specimens.

  14. Physical understanding of electron mobility in asymmetrically strained InGaAs-on-insulator metal-oxide-semiconductor field-effect transistors fabricated by lateral strain relaxation

    Energy Technology Data Exchange (ETDEWEB)

    Kim, SangHyeon, E-mail: dadembyora@mosfet.t.u-tokyo.ac.jp, E-mail: sh-kim@kist.re.kr; Yokoyama, Masafumi; Ikku, Yuki; Nakane, Ryosho; Takenaka, Mitsuru; Takagi, Shinichi [Department of Electrical Engineering and Information Systems, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656 (Japan); Ichikawa, Osamu; Osada, Takenori; Hata, Masahiko [Sumitomo Chemical Co. Ltd., 6 Kitahara, Tsukuba, Ibaraki 300-3294 (Japan)

    2014-03-17

    In this paper, we fabricated asymmetrically tensile-strained In{sub 0.53}Ga{sub 0.47}As-on-insulator (-OI) metal-oxide-semiconductor field-effect transistors (MOSFETs) using a lateral strain relaxation technique. A stripe-like line structure, fabricated in biaxially strained In{sub 0.53}Ga{sub 0.47}As-OI can lead to the lateral strain relaxation and asymmetric strain configuration in In{sub 0.53}Ga{sub 0.47}As-OI with the channel width of 100 nm. We have found that the effective mobility (μ{sub eff}) enhancement in In{sub 0.53}Ga{sub 0.47}As-OI MOSFETs with uniaxial-like asymmetric strain becomes smaller than that in In{sub 0.53}Ga{sub 0.47}As-OI MOSFETs with biaxial strain. We have clarified from a systematic analysis between the strain values and the μ{sub eff} characteristics that this mobility behavior can be understood by the change of the energy level of the conduction band minimum due to the lateral strain relaxation.

  15. Strained silicon modulation field-effect transistor as a new sensor of terahertz radiation

    Science.gov (United States)

    Moubarak Meziani, Yahya; Garcia, Enrique; Velazquez, Enrique; Diez, Enrique; El Moutaouakil, Amine; Otsuji, Taiichi; Fobelets, K.

    2011-10-01

    In this paper, we report on room temperature detection of terahertz radiation from strained-Si modulation-doped field-effect transistors. A non-resonant signal was observed with a maximum around the threshold voltage. The signal was interpreted due to the plasma wave nonlinearities in the channel. The intensity of the signal increases for the higher applied drain-to-source current. We also observed a dependence of the signal on the polarization of the incoming radiations.

  16. Large magnetic-field-induced strains in rare earth polycrystalline Ni-Mn-Ga

    Institute of Scientific and Technical Information of China (English)

    ZHAO Zengqi; WU Shuangxia; WANG Fangshu; WANG Qiang; JIANG Liping; WANG Xinlin

    2004-01-01

    The magnetic-field-induced strains (MFIS) of polycrystalline Ni50Mn29Ga21 alloys containing Tb were studied. A large MFIS of - 1.10% was obtained under compressive prestress conditions. The addition of Tb can fine the crystal grains, enhance the bending strength obviously, and make MFIS increase further, indicating that a moderate amount of Tb does not hinder twin boundary motion and it conversely makes the material more practical.

  17. Displacement and strain field assessment of PDMS using digital image correlation

    OpenAIRE

    Mendonça, B; Ribeiro, J. E.; Lopes, H.; martins, p; M. A. P. Vaz

    2013-01-01

    The main goal of this work is the characterization of the hyper-elastic mechanical behaviour of PDMS. The special specimens of PDMS (Sylgard® 184) were tested in a bi-axial tensile machine. The displacement and strain fields were measured using a commercial digital image correlation system (ARAMIS of GOM) during the tensile test. The experimental measurements are compared with numerical simulations, which use the most popular algorithms of constitutive models to characterize the hyper-elastic...

  18. Displacement and strain field assessment of PDMS using digital image correlation

    OpenAIRE

    Mendonça, B; Ribeiro, J. E.; Lopes, H.; martins, p; M. A. P. Vaz; Gomes, S.

    2013-01-01

    The main goal of this work is to characterize the hyper-elastic mechanical behaviour of PDMS. For that, were made-up special specimens of PDMS (Sylgard® 184) for test them in bi-axial tensile machine. During the tensile test was used a commercial digital image correlation system (ARAMIS of GOM) to obtain de displacement and strain fields. These measurements are compared with numerical simulations which uses the more popular algorithms of constitutive models.

  19. Genetic diversity of bovine viral diarrhoea viruses (BVDV) in Denmark during a 10-year eradication period

    DEFF Research Database (Denmark)

    Uttenthal, Åse; Stadejek, T.; Nylin, B.

    2005-01-01

    A 243 base-pair fragment of the 5'- untranslated region (5'-UTR) of bovine viral diarrhoea virus (BVDV) was RT-PCR amplified from tissue samples (after one passage) or from plasma collected from Danish cattle in 1962 (1), 1993 (7), or in 2002-03 (28) when BVD was almost extinct as a result of a 6...... subtype, the samples collected in 2002-2003 belonged to Id (22 samples), 1b (5 samples) and le (I sample) subtypes. In five herds, materials from two animals were obtained for PCR analysis. In four of five herds the sequences of the two viruses were identical, but in one herd the obtained sequences...

  20. Molecular and biological characterization of a Marek's disease virus field strain with reticuloendotheliosis virus LTR insert.

    Science.gov (United States)

    Cui, Zhizhong; Zhuang, Guoqin; Xu, Xiaoyun; Sun, Aijun; Su, Shuai

    2010-04-01

    A Marek's disease virus (MDV) field strain designated GX0101 was isolated from a layer flock and confirmed to be a recombinant virus with an insert of a long terminal repeat (LTR) from the reticuloendotheliosis virus (REV). A chimeric molecule containing an REV-LTR insert of 539 bp and its flanking sequences from MDV was amplified and sequenced. An REV-LTR downstream from the Internal Repeat Short (IRS) region has 77.4-98.6% homology to seven REV field strains isolated from different avian species in different parts of the world. The insertion site is located downstream of SORF 1 and upstream of SORF2 in the IRS region near the junction with the Unique Short (US) region in the MDV serotype 1 genome. Chicken experiments were conducted to determine the oncogenicity of the recombinant GX0101 virus and its transmissibility to contact chickens. Dot blot hybridization was used to detect the presence of the pp38 gene in feather tips from GX0101 or Md5 infected and contact birds. The pp38 was detected in GX0101 contact birds about 1-2 weeks earlier than in Md5 birds when both groups were vaccinated with HVT vaccine. Long term pathogenicity tests in specific pathogen free (SPF) chickens reveal that the recombinant GX0101 has a higher virulence than GA, but less virulence than Md5, the very virulent pathotype of MDV. This is the first report on an oncogenic serotype 1 MDV field strain with LTR insert and its pathogenicity.

  1. In-fiber Fabry-Perot interferometer for strain and magnetic field sensing.

    Science.gov (United States)

    Costa, Greice K B; Gouvêa, Paula M P; Soares, Larissa M B; Pereira, João M B; Favero, Fernando; Braga, Arthur M B; Palffy-Muhoray, Peter; Bruno, Antonio C; Carvalho, Isabel C S

    2016-06-27

    In this paper we discuss the results obtained with an in-fiber Fabry-Perot interferometer (FPI) used in strain and magnetic field (or force) sensing. The intrinsic FPI was constructed by splicing a small section of a capillary optical fiber between two pieces of standard telecommunication fiber. The sensor was built by attaching the FPI to a magnetostrictive alloy in one configuration and also by attaching the FPI to a small magnet in another. Our sensors were found to be over 4 times more sensitive to magnetic fields and around 10 times less sensitive to temperature when compared to sensors constructed with Fiber Bragg Grating (FBG).

  2. Characteristics of present-day active strain field of Chinese mainland

    Institute of Scientific and Technical Information of China (English)

    GUO Liang-qian; LI Yan-xing; YANG Guo-hua; HU Xin-kang

    2008-01-01

    On the basis of the GPS data obtained from repeated measurements carried out in 2004 and 2007, the horizontal principal strain of the Chinese mainland is calculated, which shows that the direction of principal compressive strain axis of each subplate is basically consistent with the P-axis of focal mechanism solution and the principal compressive stress axis acquired by geological method. It indicates that the crustal tectonic stress field is relatively stable in regions in a long time. The principal compressive stress axes of Qinghai-Tibet and Xinjiang subplates in the western part of Chinese mainland direct to NS and NNE-SSW, which are controlled by the force from the collision of the Eurasia Plate and India Plate. The principal compressive strain axes of Heilongjiang and North China subplates in the eastern part direct to ENE-WSW, which shows that they are subject to the force from the collision and underthrust of the Eurasia Plate to the North America and Pacific plates. At the same time, they are also affected by the lateral force from Qinghai-Tibet and Xinjiang subplates. The principal compressive strain axis of South China plate is WNW-ESE, which reflects that it is affected by the force from the collision of Philippine Sea Plate and Eurasia Plate and it is also subject to the lateral force from Qinghai-Tibet subplate. It is apparent from the comparison between the principal compressive strain axes in the periods of 2004-2007 and 2001-2004 that the acting directions of principal compressive stress of subplates in both periods are basically consistent. However, there is certain difference between their directional concentrations of principal compressive stress axes. The surface strain rates of different tectonic units in both periods indicate that the events predominating by compressive variation decrease, while the events predominating by tensile change increase.

  3. A touchdown PCR for the differentiation of equine herpesvirus type 1 (EHV-1) field strains from the modified live vaccine strain RacH.

    Science.gov (United States)

    Osterrieder, N; Hübert, P H; Brandmüller, C; Kaaden, O R

    1994-12-01

    More than 50 reference strains and field isolates of equine herpesvirus type 1 (EHV-1) were examined by a touchdown PCR. Primers for specific amplification of EHV-1 DNA were chosen from the terminal and internal repeat regions of the EHV-1 genome where the high-passaged live vaccine strain RacH displays symmetric 850 bp deletions. The positive strand and one negative strand primer were designed to encompass the deletions present in RacH, and the second negative strand primer was designed to hybridize within these deletions. Discrimination between field isolates and the vaccine strain was achieved by the generation of amplification products of different size: In all EHV-1 reference strains and field isolates, a 495 bp DNA fragment was amplified specifically, whereas a 310 bp fragment was amplified when DNA of the vaccine strain RacH was used as a template. PCR amplification was only obtained in the presence of 8-10% dimethylsulfoxide and when the primer annealing temperatures were decreased stepwise from 72 degrees C to 60 degrees C. Under these conditions as little as 100 fg template DNA, corresponding to about 100 genome equivalents, could be detected. The PCR assay allows fast and sensitive discrimination of the modified live vaccine strain RacH from field strains of EHV-1 since it is applicable to viral DNA extracted from organ samples and paraffin-embedded tissues. It may thus be helpful for examining the potential involvement of the RacH live vaccine strain in abortions of vaccinated mares.

  4. Prevalence study and genetic typing of bovine viral diarrhea virus (BVDV in four bovine species in China.

    Directory of Open Access Journals (Sweden)

    Mingliang Deng

    Full Text Available To determine the nationwide status of persistent BVDV infection in different bovine species in China and compare different test methods, a total of 1379 serum samples from clinical healthy dairy cattle, beef cattle, yaks (Bos grunniens, and water buffalo (Bubalus bubalis were collected in eight provinces of China from 2010 to 2013. The samples were analyzed using commercial antibody (Ab and antigen (Ag detection kits, and RT-PCR based on the 5'-UTR and Npro gene sequencing. Results showed that the overall positive rates for BVDV Ab, Ag and RT-PCR detection were 58.09% (801/1379, 1.39% (14/1010, and 22.64% (146/645, respectively, while the individual positive rates varied among regions, species, and farms. The average Ab-positive rates for dairy cattle, beef cattle, yaks, and water buffalo were 89.49% (298/333, 63.27% (248/392, 45.38% (236/520, and 14.18% (19/134, respectively, while the Ag-positive rates were 0.00% (0/116, 0.77% (3/392, 0.82% (3/368, and 5.97% (8/134, respectively, and the nucleic acid-positive rates detected by RT-PCR were 32.06% (42/131, 13.00% (26/200, 28.89% (52/180, and 19.40% (26/134, respectively. In addition, the RT-PCR products were sequenced and 124 5'-UTR sequences were obtained. Phylogenetic analysis of the 5'-UTR sequences indicated that all of the 124 BVDV-positive samples were BVDV-1 and subtyped into either BVDV-1b (33.06%, BVDV-1m (49.19%, or a new cluster, designated as BVDV-1u (17.74%. Phylogenetic analysis based on Npro sequences confirmed this novel subtype. In conclusion, this study revealed the prevalence of BVDV-1 in bovine species in China and the dominant subtypes. The high proportion of bovines with detectable viral nucleic acids in the sera, even in the presence of high Ab levels, revealed a serious threat to bovine health.

  5. Local magnetic fields, uplift, gravity, and dilational strain changes in Southern California ( USA).

    Science.gov (United States)

    Johnston, M.J.S.

    1986-01-01

    Measurements of regional magnetic field near the San Andreas fault at Cajon, Palmdale and Tejon are strongly correlated with changes in gravity, areal strain, and uplift in these regions during the period 1977-1984. Because the inferred relationships between these parameters are in approximate agreement with those obtained from simple deformation models, the preferred explanation appeals to short-term strain episodes independently detected in each data set. Transfer functions from magnetic to strain, gravity, and uplift perturbations, obtained by least-square linear fits to the data, are -0.98 nT/ppm, -0.03 nT/mu Gal, and 9.1 nT/m respectively. Tectonomagnetic model calculations underestimate the observed changes and those reported previously for dam loading and volcano-magnetic observations. A less likely alternative explanation of the observed data appeals to a common source of meteorologically generated crustal or instrumental noise in the strain, gravity, magnetic, and uplift data.-from Author

  6. Strain Energy Density in the Elastodynamics of the Spacetime Continuum and the Electromagnetic Field

    Directory of Open Access Journals (Sweden)

    Millette P. A.

    2013-04-01

    Full Text Available We investigate the strain energy density of the spacetime continuum in the Elasto- dynamics of the Spacetime Continuum by applying continuum m echanical results to strained spacetime. The strain energy density is a scalar. W e find that it is separated into two terms: the first one expresses the dilatation energy density (the “mass” longitu- dinal term while the second one expresses the distortion en ergy density (the “massless” transverse term. The quadratic structure of the energy rel ation of Special Relativity is found to be present in the theory. In addition, we find that the kinetic energy pc is car- ried by the distortion part of the deformation, while the dil atation part carries only the rest-mass energy. The strain energy density of the electrom agnetic energy-momentum stress tensor is calculated. The dilatation energy density (the rest-mass energy density of the photon is found to be 0 as expected. The transverse dis tortion energy density is found to include a longitudinal electromagnetic energy fl ux term, from the Poynting vector, that is massless as it is due to distortion, not dilatation, of the spacetime con- tinuum. However, because this energy flux is along the direct ion of propagation (i.e. longitudinal, it gives rise to the particle aspect of the el ectromagnetic field, the photon.

  7. Quantitative full-field strain measurements by SAOED (SrAl2O4:Eu2+,Dy3+) mechanoluminescent materials

    Science.gov (United States)

    Imani Azad, Ali; Rahimi, Mohammad Reza; Yun, Gun Jin

    2016-09-01

    In this paper, a new calibration method for mechano-luminescence (ML) thin film sensors was proposed to enable quantitative full-field strain measurements in pixel-level resolution for the first time along with two standard reference test methods. The proposed method has a distinct advantage of its facet-free full-field strain sensing capability with pixel-level resolution. For the ML sensor, standard reference test methods were proposed for developing calibrated relationships between ML light intensity and effective strains: (1) uniaxial tensile reference test and (2) non-uniform strain reference test. From the reference tests, two different calibration models were developed in a recurrence equation form and validated measuring general strain distributions on different experimental specimens. Verified finite element (FE) simulation results were compared with ML effective strains to confirm its accuracy. The comparisons of the ML effective strains with FE simulation results showed that the calibration models can acceptably measure full-field strains. Limitations, sources of errors, suggestions for improving accuracy and practical considerations were also discussed. A conclusion of this research is that the proposed method enables ML sensing films to measure quantitative full-field strain distributions.

  8. Field validation of road roughness evaluation using in-pavement strain sensors

    Science.gov (United States)

    Zhang, Z.; Deng, F.; Huang, Y.; Bridgelall, R.

    2016-04-01

    Most transportation agencies now collect pavement roughness data using the inertial profilers, which requires instrumented vehicles and technicians with specialized training to interpret the results. The extensive labor requirements of the profiling activities limit data collection for portions of the national highway system to at most once per year, resulting in outdated roughness data for decision making of maintenance needs. In this paper, a real-time roughness evaluation method was developed by linking the output of durable in-pavement strain sensors to road roughness level. The durable in-pavement sensors will continuously provide information of road roughness in real time after they are installed and calibrated during the road construction until the service life of the associated pavement. Field tests validated the developed strain method by comparison with standard inertial profiling method and the connected-vehicle method. The comparison of the results from the field tests approves the effectiveness of the developed road roughness evaluation method using in-pavement strain sensors, which can be further applied practically for needed concrete pavements.

  9. The dynamic Virtual Fields Method on rubbers at medium and high strain rates

    Directory of Open Access Journals (Sweden)

    Yoon Sung-Ho

    2015-01-01

    Full Text Available Elastomeric materials are widely used for energy absorption applications, often experiencing high strain rate deformations. The mechanical characterization of rubbers at high strain rates presents several experimental difficulties, especially associated with achieving adequate signal to noise ratio and static stress equilibrium, when using a conventional technique such as the split Hopkinson pressure bar. In the present study, these problems are avoided by using the dynamic Virtual Fields Method (VFM in which acceleration fields, clearly generated by the non-equilibrium state, are utilized as a force measurement with in the frame work of the principle of virtual work equation. In this paper, two dynamic VFM based techniques are used to characterise an EPDM rubber. These are denoted as the linear and nonlinear VFM and are developed for (respectively medium (drop-weight and high (gas-gun strain-rate experiments. The use of the two VFMs combined with high-speed imaging analysed by digital imaging correlation allows the identification of the parameters of a given rubber mechanical model; in this case the Ogden model is used.

  10. The unique effect of in-plane anisotropic strain in the magnetization control by electric field

    Science.gov (United States)

    Zhao, Y. Y.; Wang, J.; Hu, F. X.; Liu, Y.; Kuang, H.; Wu, R. R.; Sun, J. R.; Shen, B. G.

    2016-05-01

    The electric field control of magnetization in both (100)- and (011)-Pr0.7Sr0.3MnO3/Pb(Mg1/3Nb2/3)0.7Ti0.3O3(PSMO/PMN-PT) heterostructures were investigated. It was found that the in-plane isotropic strain induced by electric field only slightly reduces the magnetization at low temperature in (100)-PSMO/PMN-PT film. On the other hand, for (011)-PSMO/PMN-PT film, the in-plane anisotropic strain results in in-plane anisotropic, nonvolatile change of magnetization at low-temperature. The magnetization, remanence and coercivity along in-plane [100] direction are suppressed by the electric field while the ones along [01-1] direction are enhanced, which is ascribed to the extra effective magnetic anisotropy induced by the electric field via anisotropic piezostrains. More interestingly, such anisotropic modulation behaviors are nonvolatile, demonstrating a memory effect.

  11. The unique effect of in-plane anisotropic strain in the magnetization control by electric field

    Directory of Open Access Journals (Sweden)

    Y. Y. Zhao

    2016-05-01

    Full Text Available The electric field control of magnetization in both (100- and (011-Pr0.7Sr0.3MnO3/Pb(Mg1/3Nb2/30.7Ti0.3O3(PSMO/PMN-PT heterostructures were investigated. It was found that the in-plane isotropic strain induced by electric field only slightly reduces the magnetization at low temperature in (100-PSMO/PMN-PT film. On the other hand, for (011-PSMO/PMN-PT film, the in-plane anisotropic strain results in in-plane anisotropic, nonvolatile change of magnetization at low-temperature. The magnetization, remanence and coercivity along in-plane [100] direction are suppressed by the electric field while the ones along [01-1] direction are enhanced, which is ascribed to the extra effective magnetic anisotropy induced by the electric field via anisotropic piezostrains. More interestingly, such anisotropic modulation behaviors are nonvolatile, demonstrating a memory effect.

  12. Experimental and simulative strain field investigation of nano- and microscratches on nanolaminated (Cr, Al)N coating

    International Nuclear Information System (INIS)

    Micro- and nanoscratches were made on a nanolaminated CrN/AlN coating under different loads and velocities. The remaining vertical strain fields under the scratches were determined by measuring the bilayer periods in cross-fracture images using scanning electron microscopy. These results were compared with the remaining vertical strain fields obtained from scratch simulations utilizing the strain-rate-dependent material properties examined in preliminary work. The effect of the friction coefficient and residual stress on the strain and stress fields was investigated using simulations. The experimental and simulated strain fields show good quantitative agreement for the nanoscratches. Furthermore, the appearance of fractures and microcracks under the scratches could be correlated with strong shear stresses in simulations during indenter overrun. This method and the results obtained enable the stress–strain fields of coatings under dynamic mechanical loads to be determined quantitatively. Additionally, the possibility of determining failure criterions using scratch tests enables the simulative prediction of a coating's resistivity under real loading conditions. - Highlights: • Micro- and nanoscratches were created on a nanolaminated CrN/AlN sample. • Vertical strains under the scratch were determined via scanning electron microscopy. • The results are compared with those of finite element simulations. • The appearance of lateral microcracks is correlated with strong shear stresses. • A previously reported stress–strain determination methodology is validated

  13. Experimental and simulative strain field investigation of nano- and microscratches on nanolaminated (Cr, Al)N coating

    Energy Technology Data Exchange (ETDEWEB)

    Perne, Jan, E-mail: mail@janperne.de

    2014-12-31

    Micro- and nanoscratches were made on a nanolaminated CrN/AlN coating under different loads and velocities. The remaining vertical strain fields under the scratches were determined by measuring the bilayer periods in cross-fracture images using scanning electron microscopy. These results were compared with the remaining vertical strain fields obtained from scratch simulations utilizing the strain-rate-dependent material properties examined in preliminary work. The effect of the friction coefficient and residual stress on the strain and stress fields was investigated using simulations. The experimental and simulated strain fields show good quantitative agreement for the nanoscratches. Furthermore, the appearance of fractures and microcracks under the scratches could be correlated with strong shear stresses in simulations during indenter overrun. This method and the results obtained enable the stress–strain fields of coatings under dynamic mechanical loads to be determined quantitatively. Additionally, the possibility of determining failure criterions using scratch tests enables the simulative prediction of a coating's resistivity under real loading conditions. - Highlights: • Micro- and nanoscratches were created on a nanolaminated CrN/AlN sample. • Vertical strains under the scratch were determined via scanning electron microscopy. • The results are compared with those of finite element simulations. • The appearance of lateral microcracks is correlated with strong shear stresses. • A previously reported stress–strain determination methodology is validated.

  14. 4D STUDY OF STRAIN GRADIENTS EVOLUTION IN TWINNED NiMnGa SINGLE CRYSTALS UNDER MAGNETIC FIELD

    Energy Technology Data Exchange (ETDEWEB)

    Barabash, Rozaliya [ORNL; Xu, Ruqing [Argonne National Laboratory (ANL); Barabash, Oleg M [ORNL; Sozinov, Alexei [AdaptaMat, Finland

    2014-01-01

    Time-resolved 3D X-ray microscopy with a submicron beam size was used to follow the evolution of strains in off-stoichiometric NiMnGa twinned crystals near type I (hard) twin boundary under magnetic field. Laminate A/B microstructure was revealed near the twin boundaries in A variant. Large strain gradients are observed in the C variant in the immediate vicinity of the type I twin boundary: the lattice is under large tensile strains ~0.4% along the c- axes within first micron. Distinct a and b lattice parameter evolution with temperature and magnetic field is demonstrated. In an applied magnetic field the strain field was observed at larger distances from the twin boundary and becomes more complex. Stochastic twin boundary motion was observed after the magnetic field reaches a certain critical value.

  15. The 3-D strain patterns in Turkey using geodetic velocity fields from the RTK-CORS (TR) network

    Science.gov (United States)

    Kutoglu, Hakan Senol; Toker, Mustafa; Mekik, Cetin

    2016-03-01

    This study presents our use of GPS data to obtain and quantify the full continuous strain tensor using a 3-D velocity field in Turkey. In this study, GPS velocities improve the estimation of short-term strain tensor fields for determining the seismic hazard of Turkey. The tensorial analysis presents different aspects of deformation, such as the normal and shear strains, including their directions, the compressional and extensional strains. This analysis is appropriate for the characterizing the state of the current seismic deformation. GPS velocity data from continuous measurements (2009-2012) to estimate deformations were processed using the GAMIT/GLOBK software. Using high-rate GPS data from permanent 146 GNSS stations (RTK-CORS-TR network), the strain distribution was determined and interpolated using a biharmonic spline technique. We show the strain field patterns within axial and plane form at several critical locations, and discuss these results within the context of the seismic and tectonic deformation of Turkey. We conclude that the knowledge of the crustal strain patterns provides important information on the location of the main faults and strain accumulation for the hazard assessment. The results show an agreement between the seismic and tectonic strains confirming that there are active crustal deformations in Turkey.

  16. Strain-induced anisotropic low-field magnetoresistance of La-Sr-Mn-O thin films

    Science.gov (United States)

    Choi, Kyung-Ku; Taniyama, Tomoyasu; Yamazaki, Yohtaro

    2001-12-01

    Sputtered La0.71Sr0.29Mn1.01O3-δ (LSMO) thin films on (001) SrTiO3, polycrystalline yttria-stabilized zirconia (YSZ) and (112¯0) sapphire substrates demonstrate the distinctive low-field magnetoresistance (MR) correlated with the microstructure and the strain of the films. The epitaxial LSMO film on (001) SrTiO3 shows the in-plane magnetic anisotropy with [110] easy axis and the attendant anisotropic MR. The polycrystalline films on YSZ and sapphire substrates with grain sizes from 20 to 60 nm exhibit different anisotropic feature of transport: the isotropic MR of the film on YSZ and the large anisotropy on sapphire substrates. Moreover, in the (112¯0) film plane of sapphire substrate, the [1¯100]SAP magnetic easy axis appears due to a large tensile stress, and the longitudinal MR becomes pronounced along the [0001]SAP hard axis. This implies that the anisotropy of the low-field MR is attributed to the stress induced by the thermal expansion mismatch between film and substrate. These results emphasize that the low-field MR in the polycrystalline manganite can be advanced by the strain induced magnetic anisotropy.

  17. Strains of scattering of near-field of a point source

    Indian Academy of Sciences (India)

    M D Sharma

    2004-06-01

    Three dimensional scattering of near-field is studied for dilatation and rotation in the time domain. The perturbation method is applied to solve the equation of motion for the first order scattering from a weak inhomogeneity in an otherwise homogeneous medium. The inhomogeneity is assumed close enough to the point source so that the near-field intermediate wave is dominating over the far-field spherical and pulses. The integral expressions are derived to relate dilatation and rotation of scattering to the radial fluctuations of velocities and density in the inhomogeneity. These integrals are solved to calculate the strains of scattering from (a part of) an inhomogeneous spherical shell of arbitrary curvature. Variable curvature may allow the shape of inhomogeneity volume element to change uniformly from spherical to rectangular. Rotation of scattering from a spherical shell is independent of wave velocity inhomogeneity. Dilatation of scattering does not involve wave velocity inhomogeneity but its gradient. The back scattering results are obtained as a special case. Strains are computed numerically, for hypothetical models to study the effects of various parameters viz., velocity inhomogeneity, distance of source from inhomogeneity and from receiver, and thickness of inhomogeneity. The curvature of the spherical shell is varied to study the effects of the shape of inhomogeneous volume element on scattering.

  18. Size effects in martensitic microstructures: Finite-strain phase field model versus sharp-interface approach

    Science.gov (United States)

    Tůma, K.; Stupkiewicz, S.; Petryk, H.

    2016-10-01

    A finite-strain phase field model for martensitic phase transformation and twinning in shape memory alloys is developed and confronted with the corresponding sharp-interface approach extended to interfacial energy effects. The model is set in the energy framework so that the kinetic equations and conditions of mechanical equilibrium are fully defined by specifying the free energy and dissipation potentials. The free energy density involves the bulk and interfacial energy contributions, the latter describing the energy of diffuse interfaces in a manner typical for phase-field approaches. To ensure volume preservation during martensite reorientation at finite deformation within a diffuse interface, it is proposed to apply linear mixing of the logarithmic transformation strains. The physically different nature of phase interfaces and twin boundaries in the martensitic phase is reflected by introducing two order-parameters in a hierarchical manner, one as the reference volume fraction of austenite, and thus of the whole martensite, and the second as the volume fraction of one variant of martensite in the martensitic phase only. The microstructure evolution problem is given a variational formulation in terms of incremental fields of displacement and order parameters, with unilateral constraints on volume fractions explicitly enforced by applying the augmented Lagrangian method. As an application, size-dependent microstructures with diffuse interfaces are calculated for the cubic-to-orthorhombic transformation in a CuAlNi shape memory alloy and compared with the sharp-interface microstructures with interfacial energy effects.

  19. Field Strain Measurement on the Fiber-Epoxy Scale in CFRPs

    KAUST Repository

    Tao, Ran

    2015-06-08

    Laminated composites are materials with complex architecture made of continuous fibers (usually glass or carbon) embedded within a polymeric resin. The properties of the raw materials can vary from one point to another due to different local processing conditions or complex geometrical features for example. A first step towards the identification of these spatially varying material parameters is to image with precision the displacement fields in this complex microstructure when subjected to mechanical loading. Secondary electron images obtained by scanning electron microscopy (SEM) and then numerically deformed are post-processed by either local subset-based digital image correlation (DIC) or global finite-element based DIC to measure the displacement and strain fields at the fiber-matrix scale in a cross-ply composite. It is shown that when global DIC is applied with a conformal mesh, it can capture more accurate local variations in the strain fields as it takes into account the underlying microstructure. In comparison to subset DIC, global DIC is better suited for capturing gradients across the fiber-matrix interfaces.

  20. Elastic effects of vacancies in strontium titanate: Short- and long-range strain fields, elastic dipole tensors, and chemical strain

    OpenAIRE

    Freedman, Daniel A.; Roundy, D.; Arias, T. A.

    2008-01-01

    We present a study of the local strain effects associated with vacancy defects in strontium titanate and report the first calculations of elastic dipole tensors and chemical strains for point defects in perovskites. The combination of local and long-range results will enable determination of x-ray scattering signatures that can be compared with experiments. We find that the oxygen vacancy possesses a special property -- a highly anisotropic elastic dipole tensor which almost vanishes upon ave...

  1. Characteristics Analysis of Vertical Double Gate Strained Channel Heterostructure Metal-Oxide-Semiconductor-Field-Effect-Transistor

    Institute of Scientific and Technical Information of China (English)

    YANG Yuan; LI Gui-Ping; GAO Yong; LIU Jing

    2009-01-01

    Since device feature size shrinks continuously, there appears various short-channel effects on the fabrication and performance of devices and integrated circuits. We present a vertical double gate (VDG) strained channel heterostructure metal-oxide-semiconductor-field-effect-transistor (MOSFET). The electrical characteristics of the device with the effective gate length scaled down to 60nm are simulated. The results show that the drive current and transconductance are improved by 57.92% and 54.53% respectively, and grid swing is decreased by 36.83% over their unstrained counterparts. VDG MOSFETs exhibit a stronger capability to restrict short-channel-effects over traditional MOSFETs.

  2. Treatment of multiple resistant field strain of Ostertagia spp. in Cashmere and Angora goats.

    Science.gov (United States)

    Várady, M; Praslicka, J; Corba, J

    1994-05-01

    A multiple resistant field strain of gastro-intestinal nematodes was detected in Cashmere and Angora goats imported from New Zealand. Different treatments with three types of broad spectrum anthelmintics (albendazole, levamisole/tetramisole and ivermectin) at various dose rates are described. Satisfactory effect in Angora goats was not achieved until all three anthelmintics were administered simultaneously at twice the normal sheep dose. Post mortem worm counts and identification revealed that the resistant population consisted of 89% Ostertagia circumcincta, 6% Ostertagia ostertagi and 5% Ostertagia trifurcata. However, egg hatch assay carried out seven months later detected the presence of resistant nematodes again.

  3. Spatial modelling of the between-herd infection dynamics of bovine virus diarrhoea virus (BVDV) in dairy herds in Denmark

    DEFF Research Database (Denmark)

    Ersbøll, Annette Kjær; Ersbøll, Bjarne Kjær; Houe, H.;

    2010-01-01

    According to the current literature BVDV-infected neighbours probably impose a high risk of infection of susceptible cattle herds. In the present study, the objective was to evaluate the risk of a dairy herd changing infection status (from not having persistently infected (PI) animals to having P...

  4. Vertical transmission of bovine viral diarrhoea virus (BVDV) in mousedeer (Tragulus javanicus) and spread to domestic cattle

    DEFF Research Database (Denmark)

    Uttenthal, Åse; Høyer, M.J.; Grøndahl, C.;

    2006-01-01

    This study investigates the transmission of bovine viral diarrhoea virus (BVDV) 1f from a persistently infected (PI) lesser Malayan mousedeer to two bovine calves. Different contact routes to two calves were analysed: 1) aerosol contact between two adjacent pens without physical contact; 2...

  5. Tuning Magnetism and Electronic Phase Transitions by Strain and Electric Field in Zigzag MoS2 Nanoribbons.

    Science.gov (United States)

    Kou, Liangzhi; Tang, Chun; Zhang, Yi; Heine, Thomas; Chen, Changfeng; Frauenheim, Thomas

    2012-10-18

    Effective modulation of physical properties via external control may open various potential nanoelectronic applications of single-layer MoS2 nanoribbons (MoS2NRs). We show by first-principles calculations that the magnetic and electronic properties of zigzag MoS2NRs exhibit sensitive response to applied strain and electric field. Tensile strain in the zigzag direction produces reversible modulation of magnetic moments and electronic phase transitions among metallic, half-metallic, and semiconducting states, which stem from the energy-level shifts induced by an internal electric polarization and the competing covalent/ionic interactions. A simultaneously applied electric field further enhances or suppresses the strain-induced modulations depending on the direction of the electric field relative to the internal polarization. These findings suggest a robust and efficient approach to modulating the properties of MoS2NRs by a combination of strain engineering and electric field tuning. PMID:26292229

  6. Strain gauge fields for rippled graphene membranes under central mechanical load: an approach beyond first-order continuum elasticity

    OpenAIRE

    Sloan, James V.; SanJuan, Alejandro A. Pacheco; Wang, Zhengfei; Horvath, Cedric; Barraza-Lopez, Salvador

    2013-01-01

    We study the electronic properties of rippled freestanding graphene membranes under central load from a sharp tip. To that end, we develop a gauge field theory on a honeycomb lattice valid beyond the continuum theory. Based on the proper phase conjugation of the tight-binding pseudospin Hamiltonian, we develop a method to determine conditions under which continuum elasticity can be used to extract gauge fields from strain. Along the way, we resolve a recent controversy on the theory of strain...

  7. Typing of cytopathic and noncytopathic bovine viral diarrhea virus reference and Canadian field strains using a neutralizing monoclonal antibody.

    OpenAIRE

    Magar, R; Minocha, H C; Montpetit, C; Carman, P S; Lecomte, J.

    1988-01-01

    Cytopathic and noncytopathic reference strains as well as Canadian field isolates of bovine viral diarrhea virus were analyzed by neutralization and immunofluorescence tests using a bovine viral diarrhea virus-specific neutralizing monoclonal antibody. Results on reference strains indicated three major antigenic groups: I) NADL-like, II) New York 1-like and III) Oregon C24V-like. Field isolates could be segregated into groups I and II and none could be typed into the group III. It appears tha...

  8. Colonization of a marker and field strain of Salmonella Enteritidis and a marker strain of Salmonella Typhimurium in vancomycin pretreated and non-pretreated laying hens

    Science.gov (United States)

    This study was conducted to evaluate the effects of a vancomycin pre-treatment on the ability of marker (nalidixic acid-resistant) S. Enteritidis (SE-M), field S. Enteritidis (SE-F), and marker S. Typhimurium (ST-M) strains to colonize within the intestinal and reproductive tracts and translocate to...

  9. Characterization of field strains of infectious laryngotracheitis virus in China by restriction fragment length polymorphism and sequence analysis.

    Science.gov (United States)

    Yan, Zhuanqiang; Li, Shengpeng; Xie, Qingmei; Chen, Feng; Bi, Yingzuo

    2016-01-01

    Nineteen strains of infectious laryngotracheitis virus (ILTV; Gallid herpesvirus 1) were isolated from dead or diseased birds in chicken flocks from different areas of China between 2010 and 2014 and used to investigate ILTV epidemiology. These strains were characterized using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) patterns and sequence analysis of the thymidine kinase (TK) gene. PCR-RFLP analysis showed that the TK gene generated 2 patterns when digested with restriction endonuclease enzymes. Pattern A corresponded to 2 virulent field strains, while pattern B was characteristic of 2 virulent field strains, 15 low pathogenicity field strains, and all vaccine strains. Sequence analysis of the TK gene indicated that the messenger RNA polyadenylation signals could be identified in some isolates where amino acid 252 was threonine, and in those with methionine at that position. The present study has demonstrated that most of the outbreaks of ILT in China were caused either by low virulence strains or by vaccine-related strains, and also emphasizes the importance of reinforcing ILTV surveillance in both vaccinated and nonvaccinated flocks.

  10. Strain field of the monovacancy in silicene: First-principles study

    Directory of Open Access Journals (Sweden)

    Rui Li

    2016-05-01

    Full Text Available The in-plane strain fields of single-vacancy silicene with different monovacancy (MV concentrations, as well as the corresponding electronic band structures, are investigated by using the first-principle calculations. Firstly the self-healing MV is found to be the most stable ground structure in silicene, which is different from the other 2D hexagonal honeycomb materials, e.g. graphene, h-BN. In the isolated MV center, the bonds along the pentagons are compressed, creating a compress field, and those close to the distorted hexagons are stretched, creating a stretch field. As the MV concentration increasing, the interacted compress field tends to corrugate the defected silicene, while the interacted stretch field impacts little on the low-buckled structure. Especially, the corrugation presents in those supercells with small MV concentration, just as the (4, 5, (4, 6, (4, 7, (4, 8 supercells. The corrugations approach zero at both low and high MV concentrations, and the (4, 6 supercell with a MV concentration of about 0.021, has a peak value of 3.23Å. The electronic calculations show that the linear dispersion at Γ point in pristine silicene is broken by the lower lattice symmetry of the self-healing MV reconstruction, which translates it into metal as well.

  11. Strain field of the monovacancy in silicene: First-principles study

    Science.gov (United States)

    Li, Rui; Liu, Zhongli; Ma, Wenqiang; Tan, Yonggang

    2016-05-01

    The in-plane strain fields of single-vacancy silicene with different monovacancy (MV) concentrations, as well as the corresponding electronic band structures, are investigated by using the first-principle calculations. Firstly the self-healing MV is found to be the most stable ground structure in silicene, which is different from the other 2D hexagonal honeycomb materials, e.g. graphene, h-BN. In the isolated MV center, the bonds along the pentagons are compressed, creating a compress field, and those close to the distorted hexagons are stretched, creating a stretch field. As the MV concentration increasing, the interacted compress field tends to corrugate the defected silicene, while the interacted stretch field impacts little on the low-buckled structure. Especially, the corrugation presents in those supercells with small MV concentration, just as the (4, 5), (4, 6), (4, 7), (4, 8) supercells. The corrugations approach zero at both low and high MV concentrations, and the (4, 6) supercell with a MV concentration of about 0.021, has a peak value of 3.23Å. The electronic calculations show that the linear dispersion at Γ point in pristine silicene is broken by the lower lattice symmetry of the self-healing MV reconstruction, which translates it into metal as well.

  12. Electric-field control of magnetism via strain transfer across ferromagnetic/ferroelectric interfaces

    International Nuclear Information System (INIS)

    By taking advantage of the coupling between magnetism and ferroelectricity, ferromagnetic (FM)/ferroelectric (FE) multiferroic interfaces play a pivotal role in manipulating magnetism by electric fields. Integrating the multiferroic heterostructures into spintronic devices significantly reduces energy dissipation from Joule heating because only an electric field is required to switch the magnetic element. New concepts of storage and processing of information thus can be envisioned when the electric-field control of magnetism is a viable alternative to the traditional current based means of controlling magnetism. This article reviews some salient aspects of the electric-field effects on magnetism, providing a short overview of the mechanisms of magneto-electric (ME) coupling at the FM/FE interfaces. A particular emphasis is placed on the ME effect via interfacial magneto-elastic coupling arising from strain transfer from the FE to FM layer. Recent results that demonstrate the electric-field control of magnetic anisotropy, magnetic order, magnetic domain wall motion, and etc are described. Obstacles that need to be overcome are also discussed for making this a reality for future device applications. (topical review)

  13. Electric-field control of magnetism via strain transfer across ferromagnetic/ferroelectric interfaces

    Science.gov (United States)

    Taniyama, Tomoyasu

    2015-12-01

    By taking advantage of the coupling between magnetism and ferroelectricity, ferromagnetic (FM)/ferroelectric (FE) multiferroic interfaces play a pivotal role in manipulating magnetism by electric fields. Integrating the multiferroic heterostructures into spintronic devices significantly reduces energy dissipation from Joule heating because only an electric field is required to switch the magnetic element. New concepts of storage and processing of information thus can be envisioned when the electric-field control of magnetism is a viable alternative to the traditional current based means of controlling magnetism. This article reviews some salient aspects of the electric-field effects on magnetism, providing a short overview of the mechanisms of magneto-electric (ME) coupling at the FM/FE interfaces. A particular emphasis is placed on the ME effect via interfacial magneto-elastic coupling arising from strain transfer from the FE to FM layer. Recent results that demonstrate the electric-field control of magnetic anisotropy, magnetic order, magnetic domain wall motion, and etc are described. Obstacles that need to be overcome are also discussed for making this a reality for future device applications.

  14. Electric-field control of magnetism via strain transfer across ferromagnetic/ferroelectric interfaces.

    Science.gov (United States)

    Taniyama, Tomoyasu

    2015-12-23

    By taking advantage of the coupling between magnetism and ferroelectricity, ferromagnetic (FM)/ferroelectric (FE) multiferroic interfaces play a pivotal role in manipulating magnetism by electric fields. Integrating the multiferroic heterostructures into spintronic devices significantly reduces energy dissipation from Joule heating because only an electric field is required to switch the magnetic element. New concepts of storage and processing of information thus can be envisioned when the electric-field control of magnetism is a viable alternative to the traditional current based means of controlling magnetism. This article reviews some salient aspects of the electric-field effects on magnetism, providing a short overview of the mechanisms of magneto-electric (ME) coupling at the FM/FE interfaces. A particular emphasis is placed on the ME effect via interfacial magneto-elastic coupling arising from strain transfer from the FE to FM layer. Recent results that demonstrate the electric-field control of magnetic anisotropy, magnetic order, magnetic domain wall motion, and etc are described. Obstacles that need to be overcome are also discussed for making this a reality for future device applications.

  15. Male mating competitiveness of a Wolbachia-introgressed Aedes polynesiensis strain under semi-field conditions.

    Directory of Open Access Journals (Sweden)

    Eric W Chambers

    2011-08-01

    Full Text Available BACKGROUND: Lymphatic filariasis (LF, a global public health problem affecting approximately 120 million people worldwide, is a leading cause of disability in the developing world including the South Pacific. Despite decades of ongoing mass drug administration (MDA in the region, some island nations have not yet achieved the threshold levels of microfilaremia established by the World Health Organization for eliminating transmission. Previously, the generation of a novel Aedes polynesiensis strain (CP infected with an exogenous type of Wolbachia has been described. The CP mosquito is cytoplasmically incompatible (i.e., effectively sterile when mated with wildtype mosquitoes, and a strategy was proposed for the control of A. polynesiensis populations by repeated, inundative releases of CP males to disrupt fertility of wild females. Such a strategy could lead to suppression of the vector population and subsequently lead to a reduction in the transmission of filarial worms. METHODOLOGY/PRINCIPAL FINDINGS: CP males and F1 male offspring from wild-caught A. polynesiensis females exhibit near equal mating competitiveness with F1 females under semi-field conditions. CONCLUSIONS/SIGNIFICANCE: While laboratory experiments are important, prior projects have demonstrated the need for additional testing under semi-field conditions in order to recognize problems before field implementation. The results reported here from semi-field experiments encourage forward progression toward small-scale field releases.

  16. Modeling large reversible electric-field-induced strain in ferroelectric materials using 90° orientation switching

    Institute of Scientific and Technical Information of China (English)

    Roderick; V.; N.; MELNIK

    2009-01-01

    Reversible large electric-field-induced strain caused by reversible orientation switchings in BaTiO3 is modeled using the Landau’s theory of phase transition. A triple well free energy function is constructed. Each of its minima is associated with one of the polarization orientations involved. Nonlinear constitu- tive laws accounting for reversible orientation switchings and electrostriction effects are obtained by using thermodynamic equilibrium conditions. Hysteretic dynamics of one-dimensional structures is described by coupled nonlinear differential equations. Double hysteretic loops in the electric and me- chanic fields are both successfully modeled. Giant reversible electrostriction is modeled as a conse-quence of reversible orientation switchings via electro-mechanical couplings. Comparisons with ex-perimental results reported in literatures are presented.

  17. Modeling large reversible electric-field-induced strain in ferroelectric materials using 90° orientation switching

    Institute of Scientific and Technical Information of China (English)

    WANG LinXiang; LIU Rong; Roderick V.N.MELNIK

    2009-01-01

    Reversible large electric-field-induced strain caused by reversible orientation switchings in BaTiO3 is modeled using the Landau's theory of phase transition. A triple well free energy function is constructed, Each of its minima is associated with one of the polarization orientations involved, Nonlinear constitu-tive laws accounting for reversible orientation switchings and electrostriction effects are obtained by using thermodynamic equilibrium conditions. Hysteretic dynamics of one-dimensional structures is described by coupled nonlinear differential equations. Double hysteretic loops in the electric and me-chanic fields are both successfully modeled. Giant reversible electrostriction is modeled as a conse-quence of reversible orientation switchings via electro-mechanical couplings. Comparisons with ex-perimental results reported in literatures are presented.

  18. Comprehensive study of proteasome inhibitors against Plasmodium falciparum laboratory strains and field isolates from Gabon

    Directory of Open Access Journals (Sweden)

    Kremsner Peter G

    2008-09-01

    Full Text Available Abstract Background The emergence and spread of Plasmodium falciparum resistance to almost all available antimalarial drugs necessitates the search for new chemotherapeutic compounds. The ubiquitin/proteasome system plays a major role in overall protein turnover, especially in fast dividing eukaryotic cells including plasmodia. Previous studies show that the 20S proteasome is expressed and catalytically active in plasmodia and treatment with proteasome inhibitors arrests parasite growth. This is the first comprehensive screening of proteasome inhibitors with different chemical modes of action against laboratory strains of P. falciparum. Subsequently, a selection of inhibitors was tested in field isolates from Lambaréné, Gabon. Methods Epoxomicin, YU101, YU102, MG132, MG115, Z-L3-VS, Ada-Ahx3-L3-VS, lactacystin, bortezomib (Velcade®, gliotoxin, PR11 and PR39 were tested and compared to chloroquine- and artesunate-activities in a standardized in vitro drug susceptibility assay against P. falciparum laboratory strains 3D7, D10 and Dd2. Freshly obtained field isolates from Lambaréné, Gabon, were used to measure the activity of chloroquine, artesunate, epoxomicin, MG132, lactacystin and bortezomib. Parasite growth was detected through histidine-rich protein 2 (HRP2 production. Raw data were fitted by a four-parameter logistic model and individual inhibitory concentrations (50%, 90%, and 99% were calculated. Results Amongst all proteasome inhibitors tested, epoxomicin showed the highest activity in chloroquine-susceptible (IC50: 6.8 nM [3D7], 1.7 nM [D10] and in chloroquine-resistant laboratory strains (IC50: 10.4 nM [Dd2] as well as in field isolates (IC50: 8.5 nM. The comparator drug artesunate was even more active (IC50: 1.0 nM, whereas all strains were chloroquine-resistant (IC50: 113 nM. Conclusion The peptide α',β'-epoxyketone epoxomicin is highly active against P. falciparum regardless the grade of the parasite's chloroquine

  19. Characterization of landslide ground surface kinematics from terrestrial laser scanning and strain field computation

    Science.gov (United States)

    Teza, Giordano; Pesci, Arianna; Genevois, Rinaldo; Galgaro, Antonio

    2008-05-01

    Assessment and mitigation of the risk induced by landslide activation need an appropriate phenomenon investigation, to obtain useful information about the failure processes. The first step is the complete kinematics characterization of the landslide ground surface, by evaluating the involved displacement and deformation patterns. A dense displacement field can be obtained from comparison of a series of multi-temporal observations performed by means of terrestrial laser scanning. Subsequently, the strain field can be computed from displacement vectors. In this paper, a modified least square technique is employed to compute the strain on the nodes of a regular grid (2D approach) or on the points of a digital terrain model (3D approach). Such a computation takes into account the displacements, their spatial distribution, as well as the measurement and modelling errors. A scale factor is introduced in order to emphasize the contributions of the experimental points on the basis of their distance from each computation point, and to recognize possible scale-depending behaviours. This method has been implemented in Matlab and applied on two landslides located in the northeastern Italian Alps (Lamosano and Perarolo di Cadore). The experiments show that different kinematics can be recognized, and the presence and influence of eventual discontinuities can be revealed.

  20. Screening of Highly Effective Sinorhizobium meliloti Strains for 'Vector' Alfalfa and Testing of Its Competitive Nodulation Ability in the Field

    Institute of Scientific and Technical Information of China (English)

    ZENG Zhao-Hai; CHEN Wen-Xin; HU Yue-Gao; SUI Xin-Hua; CHEN Dan-Ming

    2007-01-01

    Seventeen Sinorhizobium meliloti strains from seven provinces in China were used to screen highly effective strains for alfalfa cultivar in a greenhouse study and their symbiotic relationship and competitive ability were studied in the field.CCBAU30138 was the most effective strain,as evidenced by increase in dry weights.A field experiment showed that the inoculation of alfalfa with CCBAU30138 resulted in increases of 11.9%and 19.6%of dry matter production and crude protein production,respectively,in forage of monocultured plants.The total dry matter yields of alfalfa and tall fescue in binary culture were increased by 16.3%by inoculation of alfalfa with this strain.These results showed that S.Meliloti strain CCBAU30138 was an effective inoculant both in the greenhouse and in the field.The analysis of randomly amplified polymorphic DNA(RAPD)by polymerase chain reaction(PCR)from nodule extracts showed that the strain CCBAU30138 had high competitiveness in the field.It occupied 47.5%of nodules in alfalfa monoculture and 44.4% of nodules in alfalfa-tall fescue binary culture after 20 weeks of growth.In conclusion,a simple system to select highly effective and competitive symbiotic strains specific to alfalfa was established.Using this system.A strain suitable for the alfalfa cultivar'Vector’grown in Wuqiao County of Hebei Province was obtained.

  1. Magnetic-field-induced strain in Ni{sub 2}MnGa melt-spun ribbons

    Energy Technology Data Exchange (ETDEWEB)

    Algarabel, P.A. E-mail: algarabe@posta.unizar.es; Magen, C.; Morellon, L.; Ibarra, M.R.; Albertini, F.; Magnani, N.; Paoluzi, A.; Pareti, L.; Pasquale, M.; Besseghini, S

    2004-05-01

    Linear thermal expansion (300-350 K) and magnetostriction measurements in magnetic fields up to 15 kOe have been performed on a Ni{sub 2}MnGa melt-spun ribbon. The magnetic-field-induced strain has been studied on a field-cooling process through the martensitic transformation and shows a maximum as a function of the applied field. This previously unreported behaviour is discussed.

  2. Finite Element Analysis of Cross Rolling on AISI 304 Stainless Steel: Prediction of Stress and Strain Fields

    Science.gov (United States)

    Rout, Matruprasad; Pal, Surjya Kanta; Singh, Shiv Brat

    2016-05-01

    Studies on the effect of strain path during rolling has been carried out for a long time, but the same has not been done using Finite Element Analysis (FEA). Change in strain path affects the state variables in the rolled plate like stress, strain, temperature etc. In the current work, Finite Element Analysis for cross rolling of AISI 304 austenitic stainless steel has been carried out by rotating the plate by 90° in between the passes. To analyze stress and strain fields in the material for cross rolling, a full 3D model of work-roll and plate has been developed using rigid-viscoplastic finite element method. The stress and strain fields, considering von-Mises yield criteria, are calculated by using updated Lagrangian method. In addition to these, the model also calculates the normal pressure and strain rate distribution in the plate during cross rolling. The nature of the variations of stress and strain fields in the plate, predicted by the model, is in good agreement with the previously published works for unidirectional rolling.

  3. On morphology and strain field of Ge/Si(001) Islands according to TEM phase imaging method.

    Science.gov (United States)

    Donnadieu, P; Neisius, T; Amiard, G; Gouyé, A; Ronda, A; Berbezier, I

    2011-10-01

    The mechanism driving Germanium islands nucleation and self-assembly is an important effect for opto-electronic applications, still not fully understood. We demonstrate that the new transmission electron microscopy phase imaging method provides insights on the distribution of strain and composition fields in and around the islands on rather large areas. The method consists of retrieving the phase from a focus series of plane view images. The phase image is representative of morphology, composition and strain. The results show that whatever the islands size and shape is, a maximum compressive strain is obtained at the apex of the islands compensated by a maximum tensile strain in the substrate close to the islands perimeter. The maximum compressive strain is associated to a larger Ge concentration. The distribution of tensile strain varies with the shape of the islands: for square base pyramidal "hut" islands, a maximum tensile strain is obtained at the four corners of the pyramid base and for "dome" islands, the tensile strain is less pronounced and affects almost the whole island perimeter. These results are consistent with the higher strain relaxation level of "dome" islands in comparison to those of "hut" islands. PMID:22400325

  4. Improved gate oxide integrity of strained Si n-channel metal oxide silicon field effect transistors using thin virtual substrates

    Science.gov (United States)

    Yan, L.; Olsen, S. H.; Escobedo-Cousin, E.; O'Neill, A. G.

    2008-05-01

    This work presents a detailed study of ultrathin gate oxide integrity in strained Si metal oxide silicon field effect transistors (MOSFETs) fabricated on thin virtual substrates aimed at reducing device self-heating. The gate oxide quality and reliability of the devices are compared to those of simultaneously processed Si control devices and conventional thick virtual substrate devices that have the same Ge content (20%), strained Si channel thickness, and channel strain. The thin virtual substrates offer the same mobility enhancement as the thick virtual substrates (˜100% compared to universal mobility data) and are effective at reducing device self-heating. Up to 90% improvement in gate leakage current is demonstrated for the strained Si n-channel MOSFETs compared to that for the bulk Si controls. The lower leakage arises from the increased electron affinity in tensile strained Si and is significant due to the sizeable strain generated by using wafer-level stressors. The strain-induced leakage reductions also lead to major improvements in stress-induced leakage current (SILC) and oxide reliability. The lower leakage current of the thin and thick virtual substrate devices compares well to theoretical estimates based on the Wentzel-Kramers-Brillouin approximation. Breakdown characteristics also differ considerably between the devices, with the strained Si devices exhibiting a one order of magnitude increase in time to hard breakdown (THBD) compared to the Si control devices following high-field stressing at 17 MV cm-1. The strained Si devices are exempted from soft breakdown. Experimental based analytical leakage modeling has been carried out across the field range for the first time in thin oxides and demonstrates that Poole-Frenkel (PF) emissions followed by Fowler-Nordheim tunneling dominate gate leakage current at low fields in all of the devices. This contrasts to the frequently reported assumption that direct tunneling dominates gate leakage in ultrathin

  5. Field study of age-differentiated strain for assembly line workers in the automotive industry.

    Science.gov (United States)

    Börner, Kerstin; Scherf, Christian; Leitner-Mai, Bianca; Spanner-Ulmer, Birgit

    2012-01-01

    A field study in an automotive supply industry company was conducted to explore age-differentiated strain of assembly line workers. Subjective and objective data from 23 female workers aged between 27 and 57 years were collected at the workplace belt buckle assembly during morning shifts. Subjects with medication or chronic diseases affecting heart rate and breath rate were excluded. For subjective data generation different questionnaires were used. Before the Work Ability Index and the Munich Chronotype Questionnaire were completed by the subjects. Short questionnaires (strain-ratings, NASA-TLX) directly at begin and end of the work were used for obtaining shift-related data. During the whole shift (6 a.m. - 2.45 p.m.) bodily functions were logged with a wireless chest strap. In addition, the motion of the hand-arm-system was recorded for 30 times, 3 minutes each after a fixed time-schedule. First results show that younger subjects need significant less time for assembly (mean = 14.940 s) compared to older subjects (mean = 17.040 s; t(472.026) = -9.278 , p < 0.01). PMID:22317519

  6. Moiré method analysis for tensile strain field of 2024 aluminum alloy welded joint

    Institute of Scientific and Technical Information of China (English)

    徐文立; 魏艳红; 刘雪松; 方洪渊; 赵敏; 田锡唐

    2003-01-01

    Using experimental mechanics method of moiré analysis, strain field distributions of 2024 aluminum alloy welded joints under different conditions were investigated. The results show that moiré stripes of welded joint without trailing peening just before fracture are not only few and scattered but also uneven, and the stress mainly concentrates on the poor position-welded toes during the tensioning process with the relatively poor mechanical properties of welded joints; When the method of welding with trailing peening is adopted, moiré stripes of welded joint just before fracture are relatively thick and even due to the strengthening welded toes during the welding process, and fracture position transfers from the welded toes to weld, at the same time the mechanical properties of welded joints are improved greatly than conventional welding which can show that the technology of trailing peening is effective to strengthen welded joints of aluminum alloy with high strength.

  7. Balancing ballistic protection against physiological strain: evidence from laboratory and field trials.

    Science.gov (United States)

    Taylor, Nigel A S; Burdon, Catriona A; van den Heuvel, Anne M J; Fogarty, Alison L; Notley, Sean R; Hunt, Andrew P; Billing, Daniel C; Drain, Jace R; Silk, Aaron J; Patterson, Mark J; Peoples, Gregory E

    2016-02-01

    This project was based on the premise that decisions concerning the ballistic protection provided to defence personnel should derive from an evaluation of the balance between protection level and its impact on physiological function, mobility, and operational capability. Civilians and soldiers participated in laboratory- and field-based studies in which ensembles providing five levels of ballistic protection were evaluated, each with progressive increases in protection, mass (3.4-11.0 kg), and surface-area coverage (0.25-0.52 m(2)). Physiological trials were conducted on volunteers (N = 8) in a laboratory, under hot-dry conditions simulating an urban patrol: walking at 4 km·h(-1) (90 min) and 6 km·h(-1) (30 min or to fatigue). Field-based trials were used to evaluate tactical battlefield movements (mobility) of soldiers (N = 31) under tropical conditions, and across functional tests of power, speed, agility, endurance, and balance. Finally, trials were conducted at a jungle training centre, with soldiers (N = 32) patrolling under tropical conditions (averaging 5 h). In the laboratory, work tolerance was reduced as protection increased, with deep-body temperature climbing relentlessly. However, the protective ensembles could be grouped into two equally stressful categories, each providing a different level of ballistic protection. This outcome was supported during the mobility trials, with the greatest performance decrement evident during fire and movement simulations, as the ensemble mass was increased (-2.12%·kg(-1)). The jungle patrol trials similarly supported this outcome. Therefore, although ballistic protection does increase physiological strain, this research has provided a basis on which to determine how that strain can be balanced against the mission-specific level of required personal protection.

  8. Monitoring bovine viral diarrhea virus (BVDV infection status in dairy herds Monitoramento do estado de infecção pelo vírus da diarrhéia viral bovina (BVDV em rebanhos bovinos leiteiros

    Directory of Open Access Journals (Sweden)

    Francisco J. Diéguez

    2008-12-01

    Full Text Available This study was designed to assess the relationship between antibodies against bovine viral diarrhea virus (BVDV determined in the bulk tank milk (BTM and the within-herd seroprevalence. We also assessed the efficiency of measuring antibody levels in BTM samples to monitor BVDV infection status in a herd. In the 81 farms included in the study, BTM samples were obtained and blood samples withdrawn from all cattle older than one year. The infection status was then determined in serum and milk using a commercial blocking ELISA based on the detection of anti-p80 antibodies. Apart from these baseline serum and milk samples, another BTM sample was collected from each herd 9 months later, and a third BTM sample obtained 9 months after this. In these second and third milk samples, anti-BVDV antibodies were determined using the same ELISA kit. Statistical tests revealed good agreement between herd seroprevalences (% seropositive animals in the herd and the antibody levels detected in the BTM samples. During the 18 months of follow-up, the farms with persistently infected cattle at the study outset (14.8% of the herds showed a significant decrease in BTM antibody titers after virus clearance. Conversely, a significant increase in BTM antibody levels was observed in the herds infected with BVDV during the follow-up period. Our findings indicate that monitoring antibody levels in the BTM is a useful method of identifying changes in the BVDV infection status of a herd.Os objetivos do presente estudo foram avaliar a relação entre os níveis de anticorpos frente ao vírus da diarréia viral bovina (BVDV no tanque de leite e a prevalência de animais seropositivos em cada rebanho; e também avaliar a eficiência da medição dos níveis de anticorpos no tanque de leite como método de monitoramento do status de infecção frente ao BVDV. Nos rebanhos estudados, obtiveram-se amostras de soro de todos os animais com idade superior a um ano, assim como uma

  9. Band Gap Modulation of Bilayer MoS2 Under Strain Engineering and Electric Field: A Density Functional Theory

    Science.gov (United States)

    Nguyen, Chuong V.; Hieu, Nguyen N.; Ilyasov, Victor V.

    2016-08-01

    In this work, we investigate band-gap tuning in bilayer MoS2 by an external electric field and by applied biaxial strain. Our calculations show that the band gaps of bilayer MoS2 can be tuned by the perpendicular electric field or biaxial strain. The band gaps of bilayer MoS2 decrease with increasing applied electric field or biaxial strain. When the electric field was introduced, electronic levels are split due to the separation of the valence sub-band and the conduction sub-band states. Our calculations also show that the change in the band gap of bilayer MoS2 is due to the separation of electronic levels by electric field via the Stark effect. At the electric field E_{Field} = 5.5 V/nm or biaxial strain ɛ = 15%, bilayer MoS2 becomes metallic. The semiconductor-metal phase transition in bilayer MoS2 plays an important role in its application for nanodevices.

  10. Band Gap Modulation of Bilayer MoS2 Under Strain Engineering and Electric Field: A Density Functional Theory

    Science.gov (United States)

    Nguyen, Chuong V.; Hieu, Nguyen N.; Ilyasov, Victor V.

    2016-05-01

    In this work, we investigate band-gap tuning in bilayer MoS2 by an external electric field and by applied biaxial strain. Our calculations show that the band gaps of bilayer MoS2 can be tuned by the perpendicular electric field or biaxial strain. The band gaps of bilayer MoS2 decrease with increasing applied electric field or biaxial strain. When the electric field was introduced, electronic levels are split due to the separation of the valence sub-band and the conduction sub-band states. Our calculations also show that the change in the band gap of bilayer MoS2 is due to the separation of electronic levels by electric field via the Stark effect. At the electric field E_{Field} = 5.5 V/nm or biaxial strain \\varepsilon = 15%, bilayer MoS2 becomes metallic. The semiconductor-metal phase transition in bilayer MoS2 plays an important role in its application for nanodevices.

  11. Application of digital image correlation to full-field measurement of shrinkage strain of dental composites

    Institute of Scientific and Technical Information of China (English)

    Jian-ying LI; Andrew LAU; Alex S.L.FOK

    2013-01-01

    Objectives:Polymerization shrinkage of dental composites remains a major concern in restorative dentistry because it can lead to micro-cracking of the tooth and debonding at the tooth-restoration interface.The aim of this study was to measure the full-field polymerization shrinkage of dental composites using the optical digital image correlation (DIC) method and to evaluate how the measurement is influenced by the factors in experiment setup and image analysis.Methods:Four commercial dental composites,Premise Dentine,Z100,Z250 and Tetric EvoCeram,were tested.Composite was first placed into a slot mould to form a bar specimen with rectangular-section of 4 mm×2 mm,followed by the surface painting to create irregular speckles.Curing was then applied at one end of the specimen while the other part were covered against curing light for simulating the clinical curing condition of composite in dental cavity.The painted surface was recorded by a charge-coupled device (CCD) camera before and after curing.Subsequently,the volumetric shrinkage of the specimen was calculated with specialist DIC software based on image cross correlation.In addition,a few factors that may influence the measuring accuracy,including the subset window size,speckle size,illumination light and specimen length,were also evaluated.Results:The volumetric shrinkage of the specimen generally decreases with increasing distance from the irradiated surface with a conspicuous exception being the composite Premise Dentine as its maximum shrinkage occurred at a subsurface distance of about 1 mm instead of the irradiated surface.Zl00 had the greatest maximum shrinkage strain,followed by Z250,Tetric EvoCeram and then Premise Dentine.Larger subset window size made the shrinkage strain contour smoother.But the cost was that some details in the heterogeneity of the material were lost.Very small subset window size resulted in a lot of noise in the data,making it difficult to discern the general pattern in the strain

  12. 稳定表达靶向BVDV shRNA细胞系的建立及其对BVDV复制的影响%Establishment of Stable Cell Line Expressing shRNA Targeting BVDV and Its Effect on the Replication of BVDV

    Institute of Scientific and Technical Information of China (English)

    范璐; 王丽; 史西保; 樊剑鸣; 王爱萍; 张改平

    2014-01-01

    为研究靶向牛病毒性腹泻病毒(BVDV)的shRNA对BVDV复制的影响,利用脂质体介导法将BVDV shRNA真核表达质粒pSGH1-sh1083和pSGH1-sh8235及对照质粒pSGH1转染MDBK 细胞,通过G418抗性以及有限稀释法筛选获得BVDV shRNA单克隆细胞系subclonepSGH1-1083 和subclonepSGH1-8235及对照细胞系subclonepshmock.通过观察其细胞病变效应(CPE)、测定TCID50及RT-PCR、流式细胞术检测BVDV shRNA细胞系对BVDV复制的影响.结果表明,与阴性对照组相比,单克隆细胞系subclonepSGH1-1083和subclonepSGH1-8235的细胞在感染BVDV 72 h后CPE不明显,其TCID50低于阴性对照组;RT-PCR结果显示,单克隆细胞系subclonepSGH1-1083和subclonepSGH1-8235的细胞在感染BVDV后病毒E2基因的表达减弱;流式细胞术检测不同细胞系接毒24 h后的结合率,单克隆细胞系subclonepSGH1-1083和subclonepSGH1-8235与病毒结合率分别为11.37%和11.51%,与对照组(20.25%)相比有所降低.综上,稳定转染BVDV shRNA的单克隆细胞系subclonepSGH1-1083和subclonepSGH1-8235对BVDV的复制具有抑制作用.

  13. Assessing Static Performance of the Dashengguan Yangtze Bridge by Monitoring the Correlation between Temperature Field and Its Static Strains

    Directory of Open Access Journals (Sweden)

    Gao-Xin Wang

    2015-01-01

    Full Text Available Taking advantage of the structural health monitoring system installed on the steel truss arch girder of Dashengguan Yangtze Bridge, the temperature field data and static strain data are collected and analyzed for the static performance assessment of the bridge. Through analysis, it is found that the static strain changes are mainly caused by temperature field (temperature and temperature difference and train. After the train-induced static strains are removed, the correlation between the remaining static strains and the temperature field shows apparent linear characteristics, which can be mathematically modeled for the description of static performance. Therefore, multivariate linear regression function combined with principal component analysis is introduced to mathematically model the correlation. Furthermore, the residual static strains of mathematical model are adopted as assessment indicator and three kinds of degradation regulations of static performance are obtained after simulation of the residual static strains. Finally, it is concluded that the static performance of Dashengguan Yangtze Bridge was in a good condition during that period.

  14. Evaluation of a commercial Erns-capture ELISA for detection of BVDV in routine diagnostic cattle serum samples

    Directory of Open Access Journals (Sweden)

    Ståhl Karl

    2007-03-01

    Full Text Available Abstract Background Bovine viral diarrhoea virus (BVDV is an important pathogen in cattle. The ability of the virus to cross the placenta during early pregnancy can result in the birth of persistently infected (PI calves. These calves shed the virus during their entire lifespan and are the key transmitters of infection. Consequently, identification (and subsequent removal of PI animals is necessary to rapidly clear infected herds from the virus. The objective of this study was to evaluate the suitability of a commercial Erns-capture ELISA, in comparison to the indirect immunoperoxidase test (IPX, for routine diagnostic detection of BVDV within a control programme. In addition, the effect of passive immunity and heat-inactivation of the samples on the performance of the ELISA was studied. Methods In the process of virus clearance within the Swedish BVDV control programme, all calves born in infected herds are tested for virus and antibodies. From such samples, sent in for routine diagnostics to SVA, we selected 220 sera collected from 32 beef herds and 29 dairy herds. All sera were tested for BVDV antigen using the Erns ELISA, and the results were compared to the results from the IPX used within the routine diagnostics. Results All 130 samples categorized as virus negative by IPX were tested negative in the ELISA, and all 90 samples categorized as virus positive were tested positive, i.e. the relative sensitivity and specificity of the ELISA was 100% in relation to IPX, and the agreement between the tests was perfect. Conclusion We can conclude that the Erns ELISA is a valid alternative that has several advantages compared to IPX. Our results clearly demonstrate that it performs well under Swedish conditions, and that its performance is comparable with the IPX test. It is highly sensitive and specific, can be used for testing of heat-inactivated samples, precolostral testing, and probably to detect PI animals at an earlier age than the IPX.

  15. Complete genome sequence of a recombinant Marek's disease virus field strain with one reticuloendotheliosis virus long terminal repeat insert.

    Science.gov (United States)

    Su, Shuai; Cui, Ning; Cui, Zhizhong; Zhao, Peng; Li, Yanpeng; Ding, Jiabo; Dong, Xuan

    2012-12-01

    Marek's disease virus (MDV) Chinese strain GX0101, isolated in 2001 from a vaccinated flock of layer chickens with severe tumors, was the first reported recombinant MDV field strain with one reticuloendotheliosis virus (REV) long terminal repeat (LTR) insert. GX0101 belongs to very virulent MDV (vvMDV) but has higher horizontal transmission ability than the vvMDV strain Md5. The complete genome sequence of GX0101 is 178,101 nucleotides (nt) and contains only one REV-LTR insert at a site 267 nt upstream of the sorf2 gene. Moreover, GX0101 has 5 repeats of a 217-nt fragment in its terminal repeat short (TRS) region and 3 repeats in internal repeat short (IRS) region, compared to the other 10 strains with only 1 or 2 repeats in both TRS and IRS.

  16. Experimental intraocular infection of exotic cockerels with field strain of velogenic Newcastle disease virus in Nigeria

    Directory of Open Access Journals (Sweden)

    Samaila Jonathan Badau

    2015-12-01

    Full Text Available Experimental intraocular (conjunctival infection of exotic cockerels with a new field strain of viscerotropic velogenic Newcastle Disease Virus (NDV was conducted to explore the concurrence of some pathological changes with humoral immune responses. After the NDV infection of 4-week-old cockerels, pathologic changes and antibody responses were observed. The clinical signs observed after the artificial inoculation included inappetence, depression, diarrhea, dyspnea, wing and leg paralysis, torticollis and weight loss. Morbidity due to the NDV was 100%, but mortality was 80% by day 18-21 post-infection. Early hyperthermia followed by terminal hypothermia, decreased packed cell volume (PCV, and 231.4 folds peak-antibody response were observed. Necrotic and/or inflammatory lesions were present in the proventriculus, intestine, liver, spleen, kidney and brain. Neurologic and digestive tract perturbations occurred in 10% and 85% of cases, respectively. The disease consistently caused stunted growth, decreased PCV, and necro-inflammatroy lesions concurrent with antibody response, suggesting probable involvement of immune-mediated mechanisms and cell membrane desialylation by viral neuraminidase in the pathogenesis.

  17. Synchrotron Radiation Study on Time-Resolved Tetragonal Lattice Strain of BaTiO3 under Electric Field

    Science.gov (United States)

    Moriyoshi, Chikako; Hiramoto, Shozo; Ohkubo, Hisanori; Kuroiwa, Yoshihiro; Osawa, Hitoshi; Sugimoto, Kunihisa; Kimura, Shigeru; Takata, Masaki; Kitanaka, Yuuki; Noguchi, Yuji; Miyayama, Masaru

    2011-09-01

    The dynamic response of an intrinsic lattice strain in a tetragonal BaTiO3 single crystal to an electric field is investigated. Time-resolved diffraction measurement using high-energy synchrotron radiation enables us to detect the time dependence of the small change in the tetragonality of BaTiO3 during polarization reversal and piezoelectric vibration after a step like electric field antiparallel to the spontaneous polarization is applied to the sample.

  18. Electrical and magneto-resistance of Co/CNT/Epoxy thin film for strain and magnetic field sensing

    Science.gov (United States)

    Anand, Sandeep V.; Isaac, Rejin; Roy Mahapatra, D.

    2009-03-01

    Cobalt and iron nanoparticles are doped in carbon nanotube (CNT)/polymer matrix composites and studied for strain and magnetic field sensing properties. Characterization of these samples is done for various volume fractions of each constituent (Co and Fe nanoparticles and CNTs) and also for cases when only either of the metallic components is present. The relation between the magnetic field and polarization-induced strain are exploited. The electronic bandgap change in the CNTs is obtained by a simplified tight-binding formulation in terms of strain and magnetic field. A nonlinear constitutive model of glassy polymer is employed to account for (1) electric bias field dependent softening/hardening (2) CNT orientations as a statistical ensemble and (3) CNT volume fraction. An effective medium theory is then employed where the CNTs and nanoparticles are treated as inclusions. The intensity of the applied magnetic field is read indirectly as the change in resistance of the sample. Very small magnetic fields can be detected using this technique since the resistance is highly sensitive to strain. Its sensitivity due to the CNT volume fraction is also discussed. The advantage of this sensor lies in the fact that it can be molded into desirable shape and can be used in fabrication of embedded sensors where the material can detect external magnetic fields on its own. Besides, the stress-controlled hysteresis of the sample can be used in designing memory devices. These composites have potential for use in magnetic encoders, which are made of a magnetic field sensor and a barcode.

  19. Dependence of elastic strain field on the self-organized ordering of quantum dot superlattices

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A systematic investigation of the strain distribution of self-organized, lens-shaped quantum dot in the case of growth direction on (001) substrate was presented. The three-dimensional finite element analysis for an array of dots was used for the strain calculation. The dependence of the strain energy density distribution on the thickness of the capping layer was investigated in detail when the elastic characteristics of the matrix material were anisotropic. It is shown that the elastic anisotropic greatly influences the stress, strain, and strain energy density in the quantum dot structures. The anisotropic ratio of the matrix material and the combination with different thicknesses of the capping layer, may lead to different strain energy density minimum locations on the capping layer surface, which can result in various vertical ordering phenomena for the next layer of quantum dots, i.e. partial alignment, random alignment, and complete alignment.

  20. Field Deployable Fiber Bragg Grating Strain Patch for Long-Term Stable Health Monitoring Applications

    OpenAIRE

    Gerhard Kalinka; Wolfgang Habel; Nadine Kusche; Vivien Schukar

    2013-01-01

    A fiber Bragg grating (FBG) strain patch specially adapted for long-term and high-strain applications has been developed and characterized. The design concept for the patch is based on a glass-fiber reinforced plastic (gfrp) carrier material. The developed concept for the FBG integration into the carrier material was derived from reliable integration procedure of FBG sensors into composite structures. The patches’ temperature sensitivity, strain gauge factor, fiber–matrix ...

  1. Occurrence, characterization and insecticidal activity of Bacillus thuringiensis strains isolated from argan fields in Morocco.

    Science.gov (United States)

    Aboussaid, H; Vidal-Quist, J C; Oufdou, K; El Messoussi, S; Castañera, P; González-Cabrera, J

    2011-01-01

    Soils collected from five locations in the argan forest (an endemic plant) in Morocco were used to form the first collection of Bacillus thuringiensis (Bt) strains from this area (58 strains). Here we found that the argan forest is a major source of Bt, as 90.62% of the samples contained Bt strains. These strains produced mainly spherical or irregular crystals that in some cases remained adhered to the spore after cell lysis. There was no strain producing bipyramidal crystals, suggesting the absence of strains bearing crv1 genes. This was confirmed by PCR analysis using eight primer pairs that can potentially detect 13 different groups of cry and cyt genes. Strains containing cry7/8 were the most abundant (25.53%), followed by strains harbouring cry9A (14.89%), cry11 (8.51%) and cry4 (4.25%). The mixtures of spores and crystals as well as culture supernatants were assayed for toxicity towards Ceratitis capitata (Medfly), showing up to 30% mortality. Our findings suggest that the argan region is a suitable target for future and wider screening programmes looking for strains bearing toxins or combinations of them to develop more efficient Bt-based formulates. PMID:21970180

  2. Analysis of a strain rate field in cold formed material using the visioplasticity method

    Directory of Open Access Journals (Sweden)

    L. Gusel

    2009-04-01

    Full Text Available In this paper the visioplasticity method is used to find the complete velocity and strain rate distributions from the experimental data, using the finite-difference method. The data about values of strain rates in plastic region of the material is very important for calculating stresses and the prediction of product quality. Specimens of copper alloy were extruded with different lubricants and different coefficients of friction and then the strain rate distributions were analysed and compared. Significant differences in velocity and strain rate distributions were obtained in some regions at the exit of the deformed zone.

  3. Population Genetic Structure of Listeria monocytogenes Strains as Determined by Pulsed-Field Gel Electrophoresis and Multilocus Sequence Typing

    Science.gov (United States)

    Henri, Clémentine; Félix, Benjamin; Guillier, Laurent; Leekitcharoenphon, Pimlapas; Michelon, Damien; Mariet, Jean-François; Aarestrup, Frank M.; Mistou, Michel-Yves; Hendriksen, René S.

    2016-01-01

    ABSTRACT Listeria monocytogenes is a ubiquitous bacterium that may cause the foodborne illness listeriosis. Only a small amount of data about the population genetic structure of strains isolated from food is available. This study aimed to provide an accurate view of the L. monocytogenes food strain population in France. From 1999 to 2014, 1,894 L. monocytogenes strains were isolated from food at the French National Reference Laboratory for L. monocytogenes and classified according to the five risk food matrices defined by the European Food Safety Authority (EFSA). A total of 396 strains were selected on the basis of different pulsed-field gel electrophoresis (PFGE) clusters, serotypes, and strain origins and typed by multilocus sequence typing (MLST), and the MLST results were supplemented with MLST data available from Institut Pasteur, representing human and additional food strains from France. The distribution of sequence types (STs) was compared between food and clinical strains on a panel of 675 strains. High congruence between PFGE and MLST was found. Out of 73 PFGE clusters, the two most prevalent corresponded to ST9 and ST121. Using original statistical analysis, we demonstrated that (i) there was not a clear association between ST9 and ST121 and the food matrices, (ii) serotype IIc, ST8, and ST4 were associated with meat products, and (iii) ST13 was associated with dairy products. Of the two major STs, ST121 was the ST that included the fewest clinical strains, which might indicate lower virulence. This observation may be directly relevant for refining risk analysis models for the better management of food safety. IMPORTANCE This study showed a very useful backward compatibility between PFGE and MLST for surveillance. The results enabled better understanding of the population structure of L. monocytogenes strains isolated from food and management of the health risks associated with L. monocytogenes food strains. Moreover, this work provided an accurate view

  4. Complement-Mediated Neutralization of Canine Distemper Virus In Vitro: Cross-Reaction between Vaccine Onderstepoort and Field KDK-1 Strains with Different Hemagglutinin Gene Characteristics

    OpenAIRE

    Mochizuki, Masami; Motoyoshi, Megumi; Maeda, Ken; Kai, Kazunari

    2002-01-01

    The properties of neutralization of antigens of canine distemper virus Onderstepoort and a recent field isolate, KDK-1, were investigated with strain-specific dog sera. A conventional neutralization assay indicated antigenic dissimilarity between the strains; however, when guinea pig complement was included in the reaction mixture, the strains were neutralized with not only the homologous but also the heterologous antibodies.

  5. Quantitative strain mapping of InAs/InP quantum dots with 1 nm spatial resolution using dark field electron holography

    DEFF Research Database (Denmark)

    Cooper, David; Rouviere, Jean-Luc; Béché, Armand;

    2011-01-01

    The optical properties of semiconductor quantum dots are greatly influenced by their strain state. Dark field electron holography has been used to measure the strain in InAs quantum dots grown in InP with a spatial resolution of 1 nm. A strain value of 5.4%60.1% has been determined which is consi...

  6. Full-field dynamic strain prediction on a wind turbine using displacements of optical targets measured by stereophotogrammetry

    Science.gov (United States)

    Baqersad, Javad; Niezrecki, Christopher; Avitabile, Peter

    2015-10-01

    Health monitoring of rotating structures (e.g. wind turbines and helicopter blades) has historically been a challenge due to sensing and data transmission problems. Unfortunately mechanical failure in many structures initiates at components on or inside the structure where there is no sensor located to predict the failure. In this paper, a wind turbine was mounted with a semi-built-in configuration and was excited using a mechanical shaker. A series of optical targets was distributed along the blades and the fixture and the displacement of those targets during excitation was measured using a pair of high speed cameras. Measured displacements with three dimensional point tracking were transformed to all finite element degrees of freedom using a modal expansion algorithm. The expanded displacements were applied to the finite element model to predict the full-field dynamic strain on the surface of the structure as well as within the interior points. To validate the methodology of dynamic strain prediction, the predicted strain was compared to measured strain by using six mounted strain-gages. To verify if a simpler model of the turbine can be used for the expansion, the expansion process was performed both by using the modes of the entire turbine and modes of a single cantilever blade. The results indicate that the expansion approach can accurately predict the strain throughout the turbine blades from displacements measured by using stereophotogrammetry.

  7. New Insights on Dynamic Recrystallization Mechanisms in Ice from High Resolution EBSD Observations and Strain Field Measurements.

    Science.gov (United States)

    Montagnat, M.; Chauve, T.; Journaux, B.; Barou, F.

    2015-12-01

    Dynamic recrystallization (DRX) strongly affects the evolution of microstructure (grain size and shape) and texture (crystal preferred orientation) during deformation at high temperature. Since texturing leads to anisotropic physical properties, predicting the effect of DRX in metals is essential for industrial applications, in rocks for interpreting geophysical data and modeling geodynamic flows, or in ice for predicting ice sheet flow and climate evolution. Along ice cores extracted from ice sheets, Continuous DRX (CDRX) and Discontinuous DRX (DDRX) mechanisms are observed at various depths, the later being favoured by the high temperature encountered close to the bedrock, and local high level of strain. In laboratory conditions, with higher strain rate and stress levels, DDRX dominates mechanical response during tertiary creep, when deviatoric stress is low enough to avoid micro fracturation (σ nucleation mechanisms and strain heterogeneities at the grain scale remain poorly known and therefore poorly constrained in DRX modeling. We will present recent observations performed on laboratory made and deformed ice polycrystals (σ ~ 0.5 MPa, T ~ -7°C) that enable to access high resolution observations of intragranular sub-structures (dislocation field, subgrains, nucleus) via Electron BackScattering Diffraction (EBSD), and high resolution strain field measurements around DRX nucleation area. Analyses of these observations highlight the complexity of nucleation mechanisms in ice, with the formation of kink bands, of bulging, and of "spontaneous" nucleation. Strain field measurements evidence the influence of nucleation on the relaxation of strain incompatibilities at grain boundaries and triple junctions. At last, torsion experiments enabled to draw hypotheses about the role of nucleation on DRX textures.

  8. The intra-observer reproducibility of cardiovascular magnetic resonance myocardial feature tracking strain assessment is independent of field strength

    Energy Technology Data Exchange (ETDEWEB)

    Schuster, Andreas, E-mail: andreas_schuster@gmx.net [Division of Imaging Sciences and Biomedical Engineering, King' s College London British Heart Foundation BHF Centre of Excellence, National Institute of Health Research NIHR Biomedical Research Centre at Guy' s and St. Thomas' NHS Foundation Trust, Wellcome Trust and Engineering and Physical Sciences Research Council EPSRC Medical Engineering Centre, The Rayne Institute, St. Thomas' Hospital, London (United Kingdom); Department of Cardiology and Pulmonology and Heart Research Centre, Georg-August-University, Göttingen (Germany); Morton, Geraint, E-mail: geraint.morton@kcl.ac.uk [Division of Imaging Sciences and Biomedical Engineering, King' s College London British Heart Foundation BHF Centre of Excellence, National Institute of Health Research NIHR Biomedical Research Centre at Guy' s and St. Thomas' NHS Foundation Trust, Wellcome Trust and Engineering and Physical Sciences Research Council EPSRC Medical Engineering Centre, The Rayne Institute, St. Thomas' Hospital, London (United Kingdom); Hussain, Shazia T., E-mail: shazia.1.hussain@kcl.ac.uk [Division of Imaging Sciences and Biomedical Engineering, King' s College London British Heart Foundation BHF Centre of Excellence, National Institute of Health Research NIHR Biomedical Research Centre at Guy' s and St. Thomas' NHS Foundation Trust, Wellcome Trust and Engineering and Physical Sciences Research Council EPSRC Medical Engineering Centre, The Rayne Institute, St. Thomas' Hospital, London (United Kingdom); and others

    2013-02-15

    Background: Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) is a promising novel method for quantification of myocardial wall mechanics from standard steady-state free precession (SSFP) images. We sought to determine whether magnetic field strength affects the intra-observer reproducibility of CMR-FT strain analysis. Methods: We studied 2 groups, each consisting of 10 healthy subjects, at 1.5 T or 3 T Analysis was performed at baseline and after 4 weeks using dedicated CMR-FT prototype software (Tomtec, Germany) to analyze standard SSFP cine images. Right ventricular (RV) and left ventricular (LV) longitudinal strain (Ell{sub RV} and Ell{sub LV}) and LV long-axis radial strain (Err{sub LAX}) were derived from the 4-chamber cine, and LV short-axis circumferential and radial strains (Ecc{sub SAX}, Err{sub SAX}) from the short-axis orientation. Strain parameters were assessed together with LV ejection fraction (EF) and volumes. Intra-observer reproducibility was determined by comparing the first and the second analysis in both groups. Results: In all volunteers resting strain parameters were successfully derived from the SSFP images. There was no difference in strain parameters, volumes and EF between field strengths (p > 0.05). In general Ecc{sub SAX} was the most reproducible strain parameter as determined by the coefficient of variation (CV) at 1.5 T (CV 13.3% and 46% global and segmental respectively) and 3 T (CV 17.2% and 31.1% global and segmental respectively). The least reproducible parameter was Ell{sub RV} (CV 1.5 T 28.7% and 53.2%; 3 T 43.5% and 63.3% global and segmental respectively). Conclusions: CMR-FT results are similar with reasonable intra-observer reproducibility in different groups of volunteers at 1.5 T and 3 T. CMR-FT is a promising novel technique and our data indicate that results might be transferable between field strengths. However there is a considerable amount of segmental variability indicating that further

  9. The intra-observer reproducibility of cardiovascular magnetic resonance myocardial feature tracking strain assessment is independent of field strength

    International Nuclear Information System (INIS)

    Background: Cardiovascular magnetic resonance myocardial feature tracking (CMR-FT) is a promising novel method for quantification of myocardial wall mechanics from standard steady-state free precession (SSFP) images. We sought to determine whether magnetic field strength affects the intra-observer reproducibility of CMR-FT strain analysis. Methods: We studied 2 groups, each consisting of 10 healthy subjects, at 1.5 T or 3 T Analysis was performed at baseline and after 4 weeks using dedicated CMR-FT prototype software (Tomtec, Germany) to analyze standard SSFP cine images. Right ventricular (RV) and left ventricular (LV) longitudinal strain (EllRV and EllLV) and LV long-axis radial strain (ErrLAX) were derived from the 4-chamber cine, and LV short-axis circumferential and radial strains (EccSAX, ErrSAX) from the short-axis orientation. Strain parameters were assessed together with LV ejection fraction (EF) and volumes. Intra-observer reproducibility was determined by comparing the first and the second analysis in both groups. Results: In all volunteers resting strain parameters were successfully derived from the SSFP images. There was no difference in strain parameters, volumes and EF between field strengths (p > 0.05). In general EccSAX was the most reproducible strain parameter as determined by the coefficient of variation (CV) at 1.5 T (CV 13.3% and 46% global and segmental respectively) and 3 T (CV 17.2% and 31.1% global and segmental respectively). The least reproducible parameter was EllRV (CV 1.5 T 28.7% and 53.2%; 3 T 43.5% and 63.3% global and segmental respectively). Conclusions: CMR-FT results are similar with reasonable intra-observer reproducibility in different groups of volunteers at 1.5 T and 3 T. CMR-FT is a promising novel technique and our data indicate that results might be transferable between field strengths. However there is a considerable amount of segmental variability indicating that further refinements are needed before CMR-FT can be fully

  10. Field Deployable Fiber Bragg Grating Strain Patch for Long-Term Stable Health Monitoring Applications

    Directory of Open Access Journals (Sweden)

    Gerhard Kalinka

    2013-01-01

    Full Text Available A fiber Bragg grating (FBG strain patch specially adapted for long-term and high-strain applications has been developed and characterized. The design concept for the patch is based on a glass-fiber reinforced plastic (gfrp carrier material. The developed concept for the FBG integration into the carrier material was derived from reliable integration procedure of FBG sensors into composite structures. The patches’ temperature sensitivity, strain gauge factor, fiber–matrix interface adhesion and fatigue behavior were characterized. As a result, FBG strain patches with linear temperature and strain behavior, as well as excellent fatigue resistance, were developed and can be used as part of a monitoring system for advanced composite materials in aerospace structures or wind turbine power plants.

  11. Evaluation of a New Entomopathogenic Strain of Beauveria bassiana and a New Field Delivery Method against Solenopsis invicta

    Science.gov (United States)

    Li, Jun; Guo, Qiang; Lin, Miaofeng; Jiang, Lu; Ye, Jingwen; Chen, Dasong; Li, Zhigang; Dai, Jianqing; Han, Shichou

    2016-01-01

    Solenopsis invicta Buren is one of the most important pests in China, and control measures are mainly based on the use of synthetic pesticides, which may be inadequate and unsustainable. Hence, there is a growing interest in developing biological control alternatives for managing S. invicta, such as the use of entomopathogenic fungi. To facilitate the commercialization of entomopathogenic fungi against S. invicta, 10 Beauveria bassiana isolates originating from different hosts were tested for virulence in laboratory bioassays, and the most pathogenic strain, ZGNKY-5, was tested in field studies using an improved pathogen delivery system. The cumulative mortality rate reached 93.40% at 1×108 mL-1 conidia after 504 h. The germination and invasion of the spores were observed under a scanning electron microscope, and several conidia adhered to the cuticle of S. invicta after 2 h. Furthermore, the germ tubes of the conidia oriented toward the cuticle after 48 h, and the mycelium colonized the entire body after 96 h. Based on the efficacy observed in the laboratory trials, further experiments were performed with ZGNKY-5 strain to evaluate its utility in an injection control technology against S. invicta in the field. We found that three dosage treatments of ZGNKY-5 strain (500 mL, 750 mL, and 1,000 mL per nest) had significant control effects. Our results show that this strain of Beauveria bassiana and our control method were effective against S. invicta in both laboratory and field settings. PMID:27341441

  12. Evaluation of a New Entomopathogenic Strain of Beauveria bassiana and a New Field Delivery Method against Solenopsis invicta.

    Directory of Open Access Journals (Sweden)

    Jun Li

    Full Text Available Solenopsis invicta Buren is one of the most important pests in China, and control measures are mainly based on the use of synthetic pesticides, which may be inadequate and unsustainable. Hence, there is a growing interest in developing biological control alternatives for managing S. invicta, such as the use of entomopathogenic fungi. To facilitate the commercialization of entomopathogenic fungi against S. invicta, 10 Beauveria bassiana isolates originating from different hosts were tested for virulence in laboratory bioassays, and the most pathogenic strain, ZGNKY-5, was tested in field studies using an improved pathogen delivery system. The cumulative mortality rate reached 93.40% at 1×108 mL-1 conidia after 504 h. The germination and invasion of the spores were observed under a scanning electron microscope, and several conidia adhered to the cuticle of S. invicta after 2 h. Furthermore, the germ tubes of the conidia oriented toward the cuticle after 48 h, and the mycelium colonized the entire body after 96 h. Based on the efficacy observed in the laboratory trials, further experiments were performed with ZGNKY-5 strain to evaluate its utility in an injection control technology against S. invicta in the field. We found that three dosage treatments of ZGNKY-5 strain (500 mL, 750 mL, and 1,000 mL per nest had significant control effects. Our results show that this strain of Beauveria bassiana and our control method were effective against S. invicta in both laboratory and field settings.

  13. A general methodology for full-field plastic strain measurements using X-ray absorption tomography and internal markers

    DEFF Research Database (Denmark)

    Haldrup, Martin Kristoffer; Nielsen, Søren Fæster; Wert, John A.

    2008-01-01

    Probing the strain locally and throughout the bulk of various materials has long been of interest in Materials Science. This article presents a general methodology for assessing the plastic strain in terms of the displacement gradient tensor throughout the bulk of opaque samples. The method relies...... on a homogenous distribution of marker particles throughout the bulk of a sample, markers which are detected through the application of synchrotron X-ray tomography. Making use of the morphology of individual markers, motion of individual markers is tracked during deformation allowing the local displacement field...

  14. Comparison of strain fields in truncated and un-truncated quantum dots in stacked InAs/GaAs nanostructures with varying stacking periods

    CERN Document Server

    Shin, H; Yoo, Y H

    2003-01-01

    Strain fields in truncated and un-truncated InAs quantum dots with the same height and base length have been compared numerically when the dots are vertically stacked in a GaAs matrix at various stacking periods. The compressive hydrostatic strain in truncated dots decreases slightly as compared with the un-truncated dots without regard to the stacking period studied. However, the reduction in tensile biaxial strain, compressive radial strain and tensile axial strain was salient in the truncated dot and the reduction increased with decreasing stacking period. From such changes in strain, changes in the band gap and related properties are anticipated.

  15. Construcción de un adenovector que exprese proteínas inmunogénicas del virus de la diarrea viral bovina (BVDV) / Construction of a recombinant adenoviral expressing immunogenic proteins of the bovine viral diarrhea virus (BVDV)

    OpenAIRE

    Vargas Bermúdez, Diana Susana

    2010-01-01

    El desarrollo de vacunas recombinantes para el control de BVDV se realiza con el fin de superar los inconvenientes de las vacunas convencionales. Para propósitos de inmunización, el adenovirus se ha empleado como vector para transportar en su genoma genes extraños (transgenes) en regiones que son eliminadas (E1 y E3) no esenciales para la replicación e infectividad viral. Estas vacunas recombinantes permiten trabajar con las proteínas más inmunogénicas del virus como la glicoproteína de la e...

  16. Digital image correlation analysis of local strain fields on Ti6Al4V manufactured by electron beam melting

    International Nuclear Information System (INIS)

    Additive manufacturing, or 3D-printing as it is often called, build parts in a layer-by-layer fashion. A common concern, regardless of the specific additive manufacturing technique used, is the risk of inadequate fusion between the adjacent layers which in turn may cause inferior mechanical properties. In this work, the local strain properties of titanium parts produced by Electron Beam Melting (EBM®) were studied in order to gain information about the quality of fusion of the stock powder material used in the process. By using Digital Image Correlation (DIC) the strain fields in the individual layers were analyzed, as well as the global strain behavior of the bulk material. The results show that fully solid titanium parts manufactured by EBM are homogenous and do not experience local deformation behavior, neither on local nor on a global level

  17. EFFECT OF STRAIN FIELD ON THRESHOLD DISPLACEMENT ENERGY OF TUNGSTEN STUDIED BY MOLECULAR DYNAMICS SIMULATION

    Energy Technology Data Exchange (ETDEWEB)

    Wang, D.; Gao, Ning; Setyawan, Wahyu; Kurtz, Richard J.; Gao, X.; He, W. H.

    2016-03-31

    The influence of hydrostatic strain on point defect formation energy and threshold displacement energy (Ed) in body-centered cubic (BCC) tungsten was studied with molecular dynamics simulations. Two different tungsten potentials (Fikar and Juslin) were used. The minimum Ed direction calculated with the Fikar-potential was <100>, but with the Juslin-potential it was <111>. The most stable self-interstitial (SIA) configuration was a <111>-crowdion for both potentials. The stable SIA configuration did not change with applied strain. Varying the strain from compression to tension increased the vacancy formation energy but decreased the SIA formation energy. The SIA formation energy changed more significantly than for a vacancy such that Ed decreased with applied strain from compression to tension.

  18. Dam Safety. Distributed Strain Measurements for Embankment Dams - Field Tests at Ajaure Dam 2004-05

    Energy Technology Data Exchange (ETDEWEB)

    Johansson, Sam [HydroResearch Sam Johansson AB, Stockholm (Sweden); Watley, Dan [Sensornet Ltd, London (United Kingdom)

    2005-09-01

    There is growing interest to measure strain in many civil structures such as dams, bridges and tunnels. Optical fibre sensors are increasingly used to measure both temperature and, strain in such constructions. Essential development of this application for dams has been made previously by Sensornet and HydroResearch, within three research projects funded by Elforsk AB. In September 2004, the first distributed measurement of strain in an embankment dam was undertaken using the Sensornet DTSS. The system allows the strain and temperature to be measured simultaneously and independently at all points along the fibre. The measurement was carried out at Vattenfall Vattenkraft's Ajaure dam in Sweden. The aim was to compare the measurements taken during September, at full reservoir level, with measurements to be taken at low reservoir level in May 2005. The measured difference of strain between the two measurements is small, indicating no significant localized movement of the dam. These initial measurements demonstrate the potential of distributed strain measurements. Whilst undertaking strain measurement at Ajaure, a series of tests were also performed to demonstrate the ability of the DTSS to determine the size of localized deflection in the dam which could be detected by distributed strain measurements. Similar tests were also repeated in the Sensornet Laboratory. Those tests have demonstrated that a deflection of the dam by just 5 mm will be detectable. The current sensitivity of the system is suitable for detecting very small localized changes of the dam structure. However, the sensitivity is set to improve with further development, providing enhanced temperature correction and hence much increased strain accuracy. Distributed optical sensing will be an essential tool for dam monitoring, providing location specific information which has not been available before. The distributed technology provides an excellent complement to conventional inclinometers. Further

  19. Genome Sequences of Two Tunisian Field Strains of Avian Mycoplasma, M. meleagridis and M. gallinarum.

    Science.gov (United States)

    Yacoub, Elhem; Sirand-Pugnet, Pascal; Barré, Aurélien; Blanchard, Alain; Hubert, Christophe; Maurier, Florence; Bouilhol, Emmanuel; Ben Abdelmoumen Mardassi, Boutheina

    2016-01-01

    Mycoplasma meleagridis and Mycoplasma gallinarum are bacteria that affect birds, but little is known about the genetic basis of their interaction with chickens and other poultry. Here, we sequenced the genomes of M. meleagridis strain MM_26B8_IPT and M. gallinarum strain Mgn_IPT, both isolated from chickens showing respiratory symptoms, poor growth, reduction in hatchability, and loss of production. PMID:27313300

  20. Virulent Properties of Russian Bovine Viral Diarrhea Virus Strains in Experimentally Infected Calves

    Directory of Open Access Journals (Sweden)

    Alexander G. Glotov

    2016-01-01

    Full Text Available The results of experimental study of three noncytopathic and two cytopathic bovine viral diarrhea virus (BVDV strains isolated from cattle in the Siberian region and belonging to the type 1 (subtypes 1a, 1b, and 1d have been presented. All investigated strains caused the development of infectious process in the seronegative 4–6-month-old calves after aerosol challenge with the dose of 6 log10 TCID50. The greatest virulence had noncytopathic strain and cytopathic strain related to the subtypes 1d and 1b, respectively. All strains in infected calves caused some signs of moderate acute respiratory disease and diarrhea: depression 3–5 days postinfection (p.i., refusal to food, severe hyperthermia to 41.9°С, serous exudate discharges from the nasal cavity and eyes, transient diarrhea with blood, leukopenia (up to 2700 cells/mm3, and macroscopic changes in the respiratory organs and intestine. The infected animals recovered from 12 to 15 days p.i. and in 90% cases formed humoral immune response 25 days p.i. (antibody titers to BVDV: 1 : 4–1 : 16. Our results confirmed the presence of virulent BVDV1 strains and showed the need for researches on the molecular epidemiology of the disease, development of more effective diagnostic systems, and optimization of control programs with use of vaccines.

  1. Virulent Properties of Russian Bovine Viral Diarrhea Virus Strains in Experimentally Infected Calves.

    Science.gov (United States)

    Glotov, Alexander G; Glotova, Tatyana I; Koteneva, Svetlana V; Semenova, Olga V; Sergeev, Alexander A; Titova, Ksenya A; Morozova, Anastasia A; Sergeev, Artemiy A

    2016-01-01

    The results of experimental study of three noncytopathic and two cytopathic bovine viral diarrhea virus (BVDV) strains isolated from cattle in the Siberian region and belonging to the type 1 (subtypes 1a, 1b, and 1d) have been presented. All investigated strains caused the development of infectious process in the seronegative 4-6-month-old calves after aerosol challenge with the dose of 6 log10 TCID50. The greatest virulence had noncytopathic strain and cytopathic strain related to the subtypes 1d and 1b, respectively. All strains in infected calves caused some signs of moderate acute respiratory disease and diarrhea: depression 3-5 days postinfection (p.i.), refusal to food, severe hyperthermia to 41.9°С, serous exudate discharges from the nasal cavity and eyes, transient diarrhea with blood, leukopenia (up to 2700 cells/mm(3)), and macroscopic changes in the respiratory organs and intestine. The infected animals recovered from 12 to 15 days p.i. and in 90% cases formed humoral immune response 25 days p.i. (antibody titers to BVDV: 1 : 4-1 : 16). Our results confirmed the presence of virulent BVDV1 strains and showed the need for researches on the molecular epidemiology of the disease, development of more effective diagnostic systems, and optimization of control programs with use of vaccines. PMID:27190687

  2. The stability of magnetic-field-induced strain in a NiMnGa ferromagnetic shape memory alloy

    Energy Technology Data Exchange (ETDEWEB)

    Chen Feng; Gao Zhiyong; Cai Wei; Zhao Liancheng [School of Materials Science and Engineering, Harbin Inst. of Tech. (China)

    2005-07-01

    The stability of magnetic field induced strain (MFIS) in Ni{sub 52}Mn{sub 24}Ga{sub 24} single crystal under temperature and magnetic field cycling is investigated and the corresponding micro-mechanism is also discussed. It shows that the saturated MFIS is very sensitive to temperature. Below martensitic transformation temperature(T{sub m}), with increasing temperature, the saturated MFIS increases almost linearly. Besides, the saturated MFIS initially decreases with increasing the field cycling number less than four times, then does not change with further increasing the number of field cycles. The decrease of saturated MFIS can be attributed to the decrease of twin boundary mobility, which is related to the crystal defect introduced by immigration of twin boundary under field cycling. (orig.)

  3. Numerical Simulation of Annual Change Patterns of Contemporary Tectonic Stress-Strain Field of the Chinese Mainland

    Institute of Scientific and Technical Information of China (English)

    Chen Lianwang; Yang Shuxin; Xie Furen; Lu Yuanzhong; Guo Ruomei

    2006-01-01

    Based on the active crustal block structures, the Holocene active faults and the wave velocity structures with a resolution of 1°× 1°, a two-dimensional finite element model for the tectonic stress-strain field of the Chinese mainland is constructed in the paper. Using GPS measurements, the velocity boundary conditions for the model are deduced, then, the annual change patterns of the present-day stress-strain field of the Chinese mainland are simulated.The results show that (1) the general pattern of the recent tectonic deformation in the Chinese mainland is governed by the interactions of its surrounding plates, of which, the Indian Plate plays a major role. There is a NNE-directed velocity distribution in the west of the Chinese mainland. The maximum slip rate appears at the collision boundary. The north-directed components decrease, while the east-directed components increase gradually from south to north and from west to east. In the east part, there is a general east-directed movement, with a certain amount of south-directed components. (2) The present-day tectonic stress field in the Chinese mainland has undergone the process of enhancement in recent years, and this process presents a general pattern of radiating eastwards from the Qinghai-Xizang (Tibet) Plateau as the center. The general pattern is similar to the ambient tectonic stress field, indicating the inheritance of contemporary tectonic deformation on the Chinese mainland. (3) The maximum principal strain presents an obvious pattern of being high in the west and low in the east. The tectonic movement in the west is stronger than that in the east. Large active faults are all located in the high-value zones of maximum principal strain. However, the magnitude of strain is smaller in the interior of the active crustal blocks, which are enclosed by these faults. (4) The stress-strain field of the Sichuan-Yunnan region is unique. It may not be governed by collision of plates alone but a combination of

  4. Full-field Strain Methods for Investigating Failure Mechanisms in Triaxial Braided Composites

    Science.gov (United States)

    Littell, Justin D.; Binienda, Wieslaw K.; Goldberg, Robert K.; Roberts, Gary D.

    2008-01-01

    Composite materials made with triaxial braid architecture and large tow size carbon fibers are beginning to be used in many applications, including composite aircraft and engine structures. Recent advancements in braiding technology have led to commercially viable manufacturing approaches for making large structures with complex shape. Although the large unit cell size of these materials is an advantage for manufacturing efficiency, the fiber architecture presents some challenges for materials characterization, design, and analysis. In some cases, the static load capability of structures made using these materials has been higher than expected based on material strength properties measured using standard coupon tests. A potential problem with using standard tests methods for these materials is that the unit cell size can be an unacceptably large fraction of the specimen dimensions. More detailed investigation of deformation and failure processes in large unit cell size triaxial braid composites is needed to evaluate the applicability of standard test methods for these materials and to develop alternative testing approaches. In recent years, commercial equipment has become available that enables digital image correlation to be used on a more routine basis for investigation of full field 3D deformation in materials and structures. In this paper, some new techniques that have been developed to investigate local deformation and failure using digital image correlation techniques are presented. The methods were used to measure both local and global strains during standard straight-sided coupon tensile tests on composite materials made with 12 and 24 k yarns and a 0/+60/-60 triaxial braid architecture. Local deformation and failure within fiber bundles was observed, and this local failure had a significant effect on global stiffness and strength. The matrix material had a large effect on local damage initiation for the two matrix materials used in this investigation

  5. Comparison of Haemophilus parasuis reference strains and field isolates by using random amplified polymorphic DNA and protein profiles

    OpenAIRE

    Zehr Emilie S; Lavrov Dennis V; Tabatabai Louisa B

    2012-01-01

    Abstract Background Haemophilus parasuis is the causative agent of Glässer’s disease and is a pathogen of swine in high-health status herds. Reports on serotyping of field strains from outbreaks describe that approximately 30% of them are nontypeable and therefore cannot be traced. Molecular typing methods have been used as alternatives to serotyping. This study was done to compare random amplified polymorphic DNA (RAPD) profiles and whole cell protein (WCP) lysate profiles as methods for dis...

  6. Strained-Si modulation doped field effect transistors as detectors of terahertz and sub-terahertz radiation

    Science.gov (United States)

    Rumyantsev, S. L.; Fobelets, K.; Veksler, D.; Hackbarth, T.; Shur, M. S.

    2008-10-01

    Strained-Si modulation doped field effect transistors have been studied as detectors of 0.2 THz and 1.6 THz electromagnetic radiation at room temperature. The difference in the gate voltage dependences for 0.2 THz and 1.6 THz radiation and spatial pattern of the transistor response to focused 1.6 THz radiation confirms that the mechanism of detection is linked to the excitations of the two-dimensional electrons in the device channel.

  7. Analysis of Stress and Strain Fields in and around Inclusions of Various Shapes in a Cylindrical Specimen Loaded in Tension

    Directory of Open Access Journals (Sweden)

    Neimitz A.

    2016-06-01

    Full Text Available A numerical analysis is performed of the stress field in and around inclusions of various shapes. Inclusions both stiffer and more compliant than the metal matrix are analysed. The critical stresses required for inclusion fracture are estimated after observation of cavities and inclusions by scanning electron microscopy. Real inclusions were observed after performing uniaxial loading to different amounts of overall strain. The material tested was Hardox-400 steel.

  8. Neural Network Prediction of Failure of Damaged Composite Pressure Vessels from Strain Field Data Acquired by a Computer Vision Method

    Science.gov (United States)

    Russell, Samuel S.; Lansing, Matthew D.

    1997-01-01

    This effort used a new and novel method of acquiring strains called Sub-pixel Digital Video Image Correlation (SDVIC) on impact damaged Kevlar/epoxy filament wound pressure vessels during a proof test. To predict the burst pressure, the hoop strain field distribution around the impact location from three vessels was used to train a neural network. The network was then tested on additional pressure vessels. Several variations on the network were tried. The best results were obtained using a single hidden layer. SDVIC is a fill-field non-contact computer vision technique which provides in-plane deformation and strain data over a load differential. This method was used to determine hoop and axial displacements, hoop and axial linear strains, the in-plane shear strains and rotations in the regions surrounding impact sites in filament wound pressure vessels (FWPV) during proof loading by internal pressurization. The relationship between these deformation measurement values and the remaining life of the pressure vessels, however, requires a complex theoretical model or numerical simulation. Both of these techniques are time consuming and complicated. Previous results using neural network methods had been successful in predicting the burst pressure for graphite/epoxy pressure vessels based upon acoustic emission (AE) measurements in similar tests. The neural network associates the character of the AE amplitude distribution, which depends upon the extent of impact damage, with the burst pressure. Similarly, higher amounts of impact damage are theorized to cause a higher amount of strain concentration in the damage effected zone at a given pressure and result in lower burst pressures. This relationship suggests that a neural network might be able to find an empirical relationship between the SDVIC strain field data and the burst pressure, analogous to the AE method, with greater speed and simplicity than theoretical or finite element modeling. The process of testing SDVIC

  9. Study on Development of Two-temperature Multiplex PCR for BVDV and BRV%BVDV与BRV二温式多重PCR检测方法的建立

    Institute of Scientific and Technical Information of China (English)

    范晴; 谢芝勋; 刘加波; 庞耀珊; 邓显文; 谢志勤; 谢丽基; 彭宜

    2011-01-01

    A two-temperature polymerase chain reaction was optimized to simultaneously detect two pathogens of BVDV and BRV . Two sets of primers were designed according to the conserved sequences of bovine viral diarrhea (BVDV) and bovine rotavirus( BRV) , yielding two specific bands of BVDV 244-bp and BRV 385-bp. A new modified two-temperature multiple PCR was developed from three-temperature conventional PCR in the study. The results showed that the specificity of the assay was high without amplification of other viruses, and the detection limit of the two-temperature multiplex PCR assay was 1 pg RNA of BVDV and BRV, respectively. This two-temperature multiplex PCR assay reported here was a valuable method with high specificity and sensitivity detection of BVDV and BRV.%根据牛病毒性腹泻病毒(BVDV)和牛轮状病毒(BRV)的保守基因设计了两对特异引物,并将三温式PCR扩增程序简化为2个温度梯度,建立了用于同时检测BVDV和BRV的二温武多重PCR方法,扩增长度分别为244和385 bp.特异性试验和敏感性试验结果表明,该方法只对BVDV和BRV模板进行扩增,而对其他对照病毒的检测均为阴性;检测灵敏度高,最低能检测到BVDV和RBV各1 pg病毒RNA.建立的BVDV和BRV二温武多重PCR方法,是一种快速、特异、敏感的检测方法.

  10. Microarray-based comparative genomic profiling of reference strains and selected Canadian field isolates of Actinobacillus pleuropneumoniae

    Directory of Open Access Journals (Sweden)

    MacInnes Janet I

    2009-02-01

    Full Text Available Abstract Background Actinobacillus pleuropneumoniae, the causative agent of porcine pleuropneumonia, is a highly contagious respiratory pathogen that causes severe losses to the swine industry worldwide. Current commercially-available vaccines are of limited value because they do not induce cross-serovar immunity and do not prevent development of the carrier state. Microarray-based comparative genomic hybridizations (M-CGH were used to estimate whole genomic diversity of representative Actinobacillus pleuropneumoniae strains. Our goal was to identify conserved genes, especially those predicted to encode outer membrane proteins and lipoproteins because of their potential for the development of more effective vaccines. Results Using hierarchical clustering, our M-CGH results showed that the majority of the genes in the genome of the serovar 5 A. pleuropneumoniae L20 strain were conserved in the reference strains of all 15 serovars and in representative field isolates. Fifty-eight conserved genes predicted to encode for outer membrane proteins or lipoproteins were identified. As well, there were several clusters of diverged or absent genes including those associated with capsule biosynthesis, toxin production as well as genes typically associated with mobile elements. Conclusion Although A. pleuropneumoniae strains are essentially clonal, M-CGH analysis of the reference strains of the fifteen serovars and representative field isolates revealed several classes of genes that were divergent or absent. Not surprisingly, these included genes associated with capsule biosynthesis as the capsule is associated with sero-specificity. Several of the conserved genes were identified as candidates for vaccine development, and we conclude that M-CGH is a valuable tool for reverse vaccinology.

  11. Prediction of Full Field Dynamic Strain from Limited Sets of Measured Data

    Directory of Open Access Journals (Sweden)

    Peter Avitabile

    2012-01-01

    Full Text Available Dynamic response is an important consideration for design of structures due to operating or occasional loadings. The resulting dynamic stress strain is also of concern for fatigue and structural health monitoring. Typically, the actual loading and structural condition (boundary conditions, environmental condition, geometry, mechanical properties, etc. are not necessarily known. Much effort is expended in attempting to identify the loads and appropriate model for prediction of these types of events. At best, the forces and actual boundary conditions are approximate and have an effect on the overall predicted response and resulting stress-strain that is identified for subsequent evaluation.

  12. Crystal orientation effects on the piezoelectric field of strained zinc-blende quantum-well structures

    DEFF Research Database (Denmark)

    Duggen, Lars; Willatzen, Morten; Lassen, Benny

    2008-01-01

    A three-layered zinc-blende quantum-well structure is analyzed subject to both static and dynamic conditions for different crystal growth directions taking into account piezoelectric effects and lattice mismatch. It is found that the strain component Szz in the quantum-well region strongly depend...

  13. Cloning and sequence analysis of genetic variation on NS2-3 of bovine viral diarrhea virus (HB-DCZ) strain in Hebei Province, China

    Institute of Scientific and Technical Information of China (English)

    ZHAO Yuelan; QIN Jianhua; GUO Hongbin; ZUO Yuzhu; ZHANG Baoning; ZHANG Lei

    2007-01-01

    The objective of this research is to analyze the genetic characterization of a bovine viral diarrhea virus (BVDV) strain (HB-DCZ strain) isolated from China and describe its relationship with other BVDV strains.Special primers (forward:5'- gagatctcgggaggtac -3',reverse:5'-cctctcggcatgatcccgaaa -3) are used to amplify partial NS2-3 sequence of HB-DCZ strain by reverse transcription polymerase chain reaction (RT-PCR).The product of PCR is cloned into pMD18-T vector,and then transfected into JM109.The recombinant plasmids are extracted and identified by EcoR Ⅰand Hind Ⅲ enzyme digestion.The NS 2-3 nucleotide fragment of the isolated virus is sequenced,and then amino acid sequence is deduced.Nucleotide sequence and deduced amino acid sequence of the strain are analyzed and compared with other BVDV strains from Genebank with the aid of DNAstar software.The results show that the obtained fragment of HB-DCZ strain contains 665 bp nucleotides,which indicate that there is no insertion in the isolated virus genome.The homologies of nucleotide sequences show that HB-DCZ strain has 99.1%,97.4%,92.3%,77%,76.9%,76.4% and 76.2%,sequence similarity with 184,ZM195,Osloss,Oregon C24V,Singer,NADL,and S D-I,respectively.According to the nucleotide sequences of the obtained fragments,the 208 corresponding amino acids are deduced.The homologies of amino acid sequences show that HB-DCZ strain had 100%,93.3%,91.3% and 83.2% sequence similarity with VEDEVAC,Osloss,ILLC and Oregon C24V,respectively.In conclusion,HB-DCZ strain has no exogenous sequence insertion,no gene recombination,no gene rearrangement and no gene deficiency.HB-DCZ strain is closely related to BVDV Osloss strain,and belongs to subtype Ib.

  14. Strain distribution and electronic structures of the InAs/GaAs quantum ring molecule in an applied electric field

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    The strain distribution and electronic structures of the InAs/GaAs quantum ring molecule are calculated via the finite element method.In our model,three identical InAs quantum rings are aligned vertically and embedded in the cubic GaAs barrier.Considering the band edge modification induced by the strain,the electronic ground state and the dependence of ground state energy on geometric parameters of the quantum ring molecule are investigated.The change of localization of the wavefunction resulting from the applied electric field along the growth direction is observed.The ground state energy decreases as the electric field intensity increases in a parabolic-like mode.The electric field changes the monotonic dependence of the energy level on the inter-ring distance into a non-monotonic one.However,the electric field has no effect on the relationships between the energy level and other geometric parameters such as the inner radius and outer radius.

  15. Electric field controlled strain induced reversible switching of magnetization in Galfenol nanomagnets delineated on PMN-PT substrate

    Science.gov (United States)

    Ahmad, Hasnain; Atulasimha, Jayasimha; Bandyopadhyay, Supriyo

    We report a non-volatile converse magneto-electric effect in elliptical Galfenol (FeGa) nanomagnets of ~300 nm lateral dimensions and ~10nm thickness delineated on a PMN-PT substrate. This effect can be harnessed for energy-efficient non-volatile memory. The nanomagnets are fabricated with e-beam lithography and sputtering. Their major axes are aligned parallel to the direction in which the substrate is poled and they are magnetized in this direction with a magnetic field. An electric field in the opposite direction generates compressive strain in the piezoelectric substrate which is partially transferred to the nanomagnets and rotates their magnetization away from the major axes to metastable orientations. There they remain after the field is removed, resulting in non-volatility. Reversing the electric field generates tensile strain which returns the magnetization to the original state. The two states can encode two binary bits which can be written using the correct voltage polarity, resulting in non-toggle behavior. Scaled memory fashioned on this effect can exhibit write energy dissipation of only ~2 aJ. Work is supported by NSF under ECCS-1124714 and CCF-1216614. Sputtering was carried out at NIST Gaithersburg.

  16. Laboratory and field evaluation of an entomopathogenic fungus, Isaria cateniannulata strain 08XS‐1, against Tetranychus urticae (Koch)

    Science.gov (United States)

    Zhang, Xiaona; Zou, Xiao; Guo, Jianjun

    2016-01-01

    Abstract BACKGROUND The two‐spotted mite, Tetranychus urticae Koch, is one of the most serious mite pests of crops throughout the world. Biocontrol of the mite with fungal agents has long been paid much attention because of the development of insecticide resistance and the severe restriction of chemical pesticides. In this study, the efficacy of submerged conidia of the entomopathogenic fungus Isaria cateniannulata strain 08XS‐1 against T. urticae eggs, larvae and female adults was evaluated at different temperatures and humidity in the laboratory and under field conditions. RESULTS The results showed that a suspension of 2 × 107 submerged conidia mL −1 caused the highest mortalities of mite eggs, larvae and females (100, 100 and 70% respectively) at 100% relative humidity and 25 °C in the laboratory. In the field experiments against the mites, a suspension of 2 × 108 submerged conidia mL −1 achieved significant efficiency – the relative control effects were 88.6, 83.8 and 83%, respectively, in cucumber, eggplant and bean fields after 10 days of treatment. CONCLUSION The results suggest that the I. cateniannulata strain 08XS‐1 is a potential fungal agent, with acceptable production cost of conidia, against T. urticae in the field in an area such as southwestern China with higher air humidity. © 2016 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry. PMID:26775712

  17. Assessment of Plasmodium falciparum resistance to ferroquine (SSR97193 in field isolates and in W2 strain under pressure

    Directory of Open Access Journals (Sweden)

    Pradines Bruno

    2006-02-01

    Full Text Available Abstract Background Ferroquine (FQ, or SSR97193, is a novel antimalarial drug currently in phase I clinical trials. FQ is a unique organometallic compound designed to overcome the chloroquine (CQ resistance problem. FQ revealed to be equally active on CQ-sensitive and CQ-resistant Plasmodium falciparum laboratory strains and field isolates. FQ is also curative on rodent malaria parasites. As FQ will be tested in patients, the potential for resistance to this drug was evaluated. Methods The relationship between CQ-resistant transporter gene genotype and susceptibility to FQ were studied in 33 Cambodian P. falciparum field isolates previously studied for their in vitro response to CQ. In parallel, the ability of the CQ-resistant strain W2, to become resistant to FQ under drug pressure was assessed. Results The IC50 values for FQ in field isolates were found to be unrelated to mutations occurring in the P. falciparum chloroquine resistance transporter (PfCRT or to the level of expression of the corresponding mRNA. In vitro, under a drug pressure of 100 nM of FQ, transient survival was observed in only one of two experiments. Conclusion Field isolates studies and experimental drug pressure experiments showed that FQ overcomes CQ resistance, which reinforces the potential of this compound as a new antimalarial drug.

  18. 猪源牛病毒性腹泻病毒SH-28分离株的全基因组序列及遗传进化分析%Complete genomic sequencing and analysis of the pig bovine viral diarrhea virus strain SH-28

    Institute of Scientific and Technical Information of China (English)

    陶洁; 王银; 廖金虎; 杨颖; 羊扬; 朱国强

    2013-01-01

    The complete genome of a pig bovine viral diarrhea virus (BVDV) SH-28 was sequenced in order to analyze the genetic difference between pig BVDV and bovine BVDV. Amplified by RT-PCR,18 fragments of SH-28 were cloned into pGEM-T and then sent for sequencing by commerical serves. The retrieved sequences were timed and aligned with CLUSTX(1.8) and Lasergene. Ultimately, we obtained the complete sequence of SH-28. The genome of SH-28 comprises 12 279 nucleotides and contains a large open reading frame (ORF) encoding a polyprotein of 3 895 amino acids. The 5',3'-untranslated region (5'-UTR,3'-UTR) are 385 nt and 206 nt, respectively. The phylogenetic tree of complete sequence showed that SH-28 and HLJ-10 were in the same branch,yet it was most similar to XJ-04 (92. 3%) and divergent with the other pig BVDV-1 (ZM-95,SD0806)(70. 0%,70. 1%). The phylogenetic tree of 5'-UTR showed that SH-28 belonged to BVDV-2a2 while HLJ-10 and XJ-04 were classified into BVDV-2al. Therefore, we speculate that SH-28 is a new BVDV-2 isolate different from the previous BVDV-2 strains and may originate from bovine BVDV-2.%为了解猪源牛病毒性腹泻病毒(BVDV)与牛源BVDV在遗传特性上的差异,本试验对实验室分离保存的1株猪源BVDV(SH-28)进行了全基因组测序.利用反转录-聚合酶链式反应(RT-PCR)方法分段扩增了SH-28分离株的18条cDNA片段,分别克隆于pGEM-T质粒载体并进行测序,用CLUSTX(1.8)和Lasergene软件进行序列的剪切和拼接,最终获得SH-28基因组序列全长为12 279个核苷酸(nt),开放阅读框(ORF)长11 685 nt,编码3 895个氨基酸(aa),5'-UTR和3’-UTR分别长385 nt和206 nt.全基因组进化树结果表明,虽然SH-28与HLJ-10同处于一个分支上,但其与XJ-04的全基因组核苷酸同源性最高(92.3%),而与另外2株猪源BVDV-1(ZM-95、SD0806)的亲缘性较远(70.0%、70.1%).5’-UTR进化树结果显示,SH-28分离株属于BVDV-2a2基因亚型,而HLJ-10和J-04株属于BVDV-2a1.

  19. New bridge-circuit-type detector to measure precise resistance change of strain gauge at low temperature and magnetic field

    Science.gov (United States)

    Ohashi, Masashi; Kishii, Nobuya; Tateno, Shota

    2016-04-01

    We report a new highly accurate and versatile bridge-circuit-type detector that has a simple structure and demonstrates a low degree of error for measurements of thermal expansion and magnetostriction by the strain gauge method. As an example, a commercial physical property measurement system (PPMS) is combined with a compact bridge-circuit box. Thermal expansion and magnetostriction are calculated from the resistance of the bridge and bridge voltage, measured by the operation of a standard PPMS resistivity option. The performance of the new detector is demonstrated by measuring the temperature and magnetic field dependences of the strain to obtain the thermal expansion coefficient and magnetostriction of the single crystals of rare-earth compounds RAl2 (R = Dy, Tb).

  20. Effect of uniaxial strain on electrical properties of CNT-based junctionless field-effect transistor: Numerical study

    Science.gov (United States)

    Pourian, Parisa; Yousefi, Reza; Ghoreishi, Seyed Saleh

    2016-05-01

    Numerical studies on junctionless carbon nanotube field-effect transistors (JL-CNTFETs) have indicated that these devices produce more ON current than silicon junctionless transistors in comparable dimensions. Nevertheless, due to the smaller bandgap and quantum confinement effects, they provide weaker results in the OFF state. Since the change of energy bandgap is one of the effects of applying uniaxial strain on CNTs, in this paper, using non-equilibrium Green's function method (NEGF), the effects of applying strain on electrical characteristics of JL-CNTFETs, such as ION and IOFF, intrinsic delay, ION/IOFF ratio, power-delay product, unity-gain frequency, gate transconductance, and output resistance are investigated. The simulation results show that uniaxial stain, significantly alters the OFF state behavior and as a result the electrical properties of the device.

  1. A comparative study of P450 gene expression in field and laboratory Musca domestica L. strains

    DEFF Research Database (Denmark)

    Højland, Dorte Heidi; Vagn Jensen, Karl-Martin; Kristensen, Michael

    2014-01-01

    BACKGROUND The housefly is a global pest that has developed resistance to most insecticides applied for its control. Resistance has been associated with cytochrome P450 monooxygenases (P450s). The authors compare the expression of six genes possibly associated with insecticide resistance in three...... in the multiresistant strain (P houseflies indicates a possible role of this gene in metabolic resistance. There is a strong indication...

  2. Correlation between clinico-pathological outcome and typing of Haemophilus parasuis field strains

    OpenAIRE

    Aragon, Virginia; Cerdà-Cuéllar, Marta; Fraile, Lorenzo; Mombarg, Mark; Nofrarías, Miquel; Olvera, Alexandre; Sibila, Marina; Solanes, David; Segalés, Joaquim

    2010-01-01

    Abstract Haemophilus parasuis is the etiologic agent of Glasser's disease in pigs, which is pathologically characterized by serofibrinous polyserositis and arthritis. H. parasuis include virulent and non-virulent strains and confirmation of virulence in H. parasuis is still dependent on experimental reproduction of the disease. Since the variability in virulence is supported by serotyping and genotyping (particularly, multilocus sequence typing [MLST]), we examined the relationship...

  3. Full-Field Measurements on Low-Strained Geomaterials Using Environmental Scanning Electron Microscopy and Digital Image Correlation: Improved Imaging Conditions

    OpenAIRE

    Wang, Linlin; Bornert, Michel; Heripre, Eva; CHANCHOLE, Serge; TANGUY, Alexandre

    2014-01-01

    Full-field strain measurement at microscale on geomaterials by means of hydromechanical in situ testing and imaging in an environmental scanning electron microscope and digital image correlation techniques is a challenging task because of both low magnitude of investigated strains (typically of the order of 10?3) and unfavourable imaging conditions. In view of improving strain measurement accuracy, three major sources of measurement errors are evaluated, and methods to minimise their effects ...

  4. Physical and genetic mapping of the genomes of five Mycoplasma hominis strains by pulsed-field gel electrophoresis

    DEFF Research Database (Denmark)

    Ladefoged, Søren; Christiansen, Gunna

    1992-01-01

    We present the complete maps of five Mycoplasma hominis genomes, including a detailed restriction map and the locations of a number of genetic loci. The restriction fragments were resolved by field inversion gel electrophoresis or by the contour-clamped homogeneous-electric-field system of pulsed......-field gel electrophoresis. All the ApaI, SmaI, BamHI, XhoI, and SalI restriction sites (total of 21 to 33 sites in each strain) were placed on the physical map, yielding an average resolution of 26 kb. The maps were constructed using three different approaches: (i) size determination of DNA fragments...... partially or completely cleaved with one or two restriction enzymes, (ii) hybridization analysis with purified restriction fragments and specific probes, and (iii) use of linking clones. A genetic map was constructed by hybridization with gene-specific probes for rpoA, rpoC, rrn, tuf, gyrB, hup, fts...

  5. Dot-field effect transistor: Using locally strained silicon for MOSFET applications

    Energy Technology Data Exchange (ETDEWEB)

    Moers, Juergen; Gerharz, Julian; Mussler, Gregor; Gruetzmacher, Detlev [Institute for Bio and Nanosystems, Research Centre Juelich (Germany); Biasotto, Cleber; Jovanovic, Vladimir; Nanver, Lis [DIMES, TU Delft (Netherlands)

    2010-07-01

    Typical dimensions of electronic devices have been scaled into the sub-50 nm range. The use of trained silicon for carrier mobility enhancement is a route to meet the challenges occurring at those dimensions. By means of templated self assembly of SiGe-dots on prepatterned substrates and epitaxial overgrowth a silicon layer is created, which is strained on top of the SiGe-dots and their near vicinity. Integrating the MOSFET on the dot will use the strain to improve the device performance. During processing special emphasis has to be laid on the overlay accuracy and low thermal budget processing to prevent intermixing of the strained silicon layer with the SiGe-dot. While the gate dielectric was deposited by CVD the activation of dopants was done by laser annealing. DotFET devices with gate lengths between 50 and 200 nm and gate widths between 100 and 300 nm were fabricated with 15 nm SiON as gate dielectric. First measurements show an improved current drivability in respect to reference devices processed on the same wafer, indicating the suitability of this device concept. Further improvements can be reached by removing the SiGe-dot from beneath the gate.

  6. Laboratory and field evaluation of entomopathogenic fungi for the control of amitraz-resistant and susceptible strains of Rhipicephalus decoloratus.

    Science.gov (United States)

    Murigu, Mercy M; Nana, Paulin; Waruiru, Robert M; Nga'nga', Chege J; Ekesi, Sunday; Maniania, Nguya K

    2016-07-30

    Rhipicephalus decoloratus causes serious economic losses in cattle industry every year in East Africa. Biological control using entomopathogenic fungi is seen as a promising alternative to chemical acaricides being used for their control. The pathogenicity of Metarhizium anisopliae and of Beauveria bassiana isolates was tested in the laboratory against amitraz-resistant and amitraz-susceptible strains of R. decoloratus. Unfed larvae were sprayed with conidial suspensions of 1×10(9) conidia ml(-1). Fungal isolates were pathogenic to R. decoloratus larvae, causing mortality of between 10.0 and 100% and between 12.1 and 100% of amitraz-susceptible and amitraz-resistant strains, respectively. The LT50 values of selected fungal isolates varied between 2.6-4.2days in amitraz-susceptible strain and between 2.8-3.9days in amitraz-resistant strain. The LC50 values varied between 0.4±0.1 and 200.0±60×10(3) conidia ml(-1) and between 0.1±0.1 and 200.0±31.0×10(3) conidia ml(-1) in amitraz-susceptible and amitraz-resistant strains, respectively. Metarhizium anisopliae isolate ICIPE 7 outperformed the other isolates and was selected for compatibility study with amitraz and field trial. ICIPE 7 was compatible with amitraz. In the field, four treatments including control, ICIPE 7 alone, amitraz alone and ICIPE 7/amitraz were applied on cattle. All the treatments significantly reduced the number of ticks on all the sampling dates: day 7 (F3,8=3.917; P=0.0284), day 14 (F3,8=9.090; P=0.0275), day 21 (F3,8=37.971; P=0.0001) and day 28 (F3,8=8.170; P=0.0016) compared to the control. Results of the present study indicate that ICIPE 7 can be used for the management of amitraz-resistant strain of R. decoloratus. PMID:27369570

  7. Comparison of the breadth and complexity of bovine viral diarrhea (BVDV) populations circulating in 34 persistently infected cattle generated in one outbreak

    Science.gov (United States)

    Exposure to bovine viral diarrhea viruses (BVDV) may result in acute and persistent infections. Persistent infections are the consequence of in utero exposure during the first trimester of gestation. The resulting persistently infected (PI) animals are immunotolerant to the virus. Clinical presen...

  8. Aspergillus flavus genetic diversity of corn fields treated with non-toxigenic strain afla-guard in the southern U.S

    Science.gov (United States)

    Aspergillus flavus genetic diversity of corn fields treated with the non-toxigenic strain Afla-Guard (NRRL 21882) was determined for 384 A. flavus isolates from 14 locations within 6 states in the southern U.S. ELISA test has determined low levels of toxigenic strains (only 91 positive). Nearly hal...

  9. Virulent Properties of Russian Bovine Viral Diarrhea Virus Strains in Experimentally Infected Calves

    OpenAIRE

    Glotov, Alexander G.; Tatyana I. Glotova; Koteneva, Svetlana V.; Semenova, Olga V.; Alexander A. Sergeev; Titova, Ksenya A.; Morozova, Anastasia A.; Sergeev, Artemiy A.

    2016-01-01

    The results of experimental study of three noncytopathic and two cytopathic bovine viral diarrhea virus (BVDV) strains isolated from cattle in the Siberian region and belonging to the type 1 (subtypes 1a, 1b, and 1d) have been presented. All investigated strains caused the development of infectious process in the seronegative 4–6-month-old calves after aerosol challenge with the dose of 6 log10 TCID50. The greatest virulence had noncytopathic strain and cytopathic strain related to the subtyp...

  10. The Advance of Molecular Biology Research of BVDV%牛病毒性腹泻-粘膜病病毒(BVDV)的分子生物学研究进展

    Institute of Scientific and Technical Information of China (English)

    项勋; 段纲; 李志敏

    2004-01-01

    牛病毒性腹泻-粘膜病病毒(Bovine viral diarrhea-mucosal disease virus,BVDV)是引起牛病毒性腹泻-粘膜病的病原,欧美牛体中普遍存在轻性或隐性感染,与猪瘟病毒(HCV)、羊边界病病毒(BDV)具有1种共同抗原,有交叉反应,牛体中的抗体检出率高.本文通过对BVDV的分子生物学的概述,总结BVDV最新的分子生物学研究进展,为进一步预防和控制BVDV提供理论依据.

  11. 牛病毒性腹泻/黏膜病病毒(BVDV/MDV)的分子生物学研究进展%Prospect of the molecular biology study on BVDV/MDV

    Institute of Scientific and Technical Information of China (English)

    姜宇; 刘亚刚; 吴皎; 张金灵; 贾清

    2006-01-01

    牛病毒性腹泻/粘膜病病毒(Bovine viral diarrhea virus/mucosal disease virus,BVDV/MDV)是引起牛病毒性腹泻/粘膜病的病原,与猪瘟病毒(CSFV)、羊边界病病毒(BDV)同属.其基因组由5'非翻译区(5'UTR)、一个大的开放阅读框(ORF)和3'非编码区(3'NCR)组成,编码结构蛋白P14、gP48、gP25、gP53及几种非结构蛋白.下面就BVD/MD的分子生物学研究进展做一综述,以便给该病的进一步防制奠定理论基础.

  12. Strains and axial outflows in the field of a rotating black hole

    CERN Document Server

    Bini, Donato; Geralico, Andrea

    2014-01-01

    We study the behaviour of an initially spherical bunch of accelerated particles emitted along trajectories parallel to the symmetry axis of a rotating black hole. We find that, under suitable conditions, curvature and inertial strains compete to model the shape of axial outflows of matter contributing to generate jet-like structures. This is of course a purely kinematical effect which does not account by itself for physical processes underlying the formation of jets. In our analysis a crucial role is played by a property of the electric and magnetic part of the Weyl tensor to be Lorentz-invariant boosting along the axis of symmetry in Kerr spacetime.

  13. Random amplified polymorphic DNA assay is less discriminant than pulsed-field gel electrophoresis for typing strains of methicillin-resistant Staphylococcus aureus.

    OpenAIRE

    Saulnier, P; Bourneix, C; Prévost, G; Andremont, A

    1993-01-01

    Twenty-six strains of methicillin-resistant Staphylococcus aureus with different pulsed-field gel electrophoresis fingerprints were tested by random amplified polymorphic DNA assay with three primers, resulting in 15 to 20 different random amplified polymorphic DNA fingerprints. By summing the results for the three primers, the number of different fingerprints increased to 25, but two strains could not be differentiated. We conclude that pulsed-field gel electrophoresis remains the best metho...

  14. A infecção pelo vírus da diarréia viral bovina (BVDV) no Brasil: histórico, situação atual e perspectivas Bovine viral diarrhea virus (BVDV) infection in Brazil: history, current situation and perspectives

    OpenAIRE

    Flores, Eduardo F; Rudi Weiblen; Fernanda S. Flores Vogel; Paulo M. Roehe; Amauri A. Alfieri; Edviges M. Pituco

    2005-01-01

    O vírus da Diarréia Viral Bovina (BVDV) possui distribuição mundial e é considerado um dos principais patógenos de bovinos. A infecção e as enfermidades associadas ao BVDV têm sido descritas no Brasil desde os anos 60. Diversos relatos sorológicos, clínico-patológicos e de isolamento do agente demonstram a ampla disseminação da infecção no rebanho bovino brasileiro. Além de sorologia positiva em níveis variáveis em bovinos de corte e leite, anticorpos contra o BVDV têm sido ocasionalmente det...

  15. Sudden motility reversal indicates sensing of magnetic field gradients in Magnetospirillum magneticum AMB-1 strain.

    Science.gov (United States)

    González, Lina M; Ruder, Warren C; Mitchell, Aaron P; Messner, William C; LeDuc, Philip R

    2015-06-01

    Many motile unicellular organisms have evolved specialized behaviors for detecting and responding to environmental cues such as chemical gradients (chemotaxis) and oxygen gradients (aerotaxis). Magnetotaxis is found in magnetotactic bacteria and it is defined as the passive alignment of these cells to the geomagnetic field along with active swimming. Herein we show that Magnetospirillum magneticum (AMB-1) show a unique set of responses that indicates they sense and respond not only to the direction of magnetic fields by aligning and swimming, but also to changes in the magnetic field or magnetic field gradients. We present data showing that AMB-1 cells exhibit sudden motility reversals when we impose them to local magnetic field gradients. Our system employs permalloy (Ni(80)Fe(20)) islands to curve and diverge the magnetic field lines emanating from our custom-designed Helmholtz coils in the vicinity of the islands (creating a drop in the field across the islands). The three distinct movements we have observed as they approach the permalloy islands are: unidirectional, single reverse and double reverse. Our findings indicate that these reverse movements occur in response to magnetic field gradients. In addition, using a permanent magnet we found further evidence that supports this claim. Motile AMB-1 cells swim away from the north and south poles of a permanent magnet when the magnet is positioned less than ∼30 mm from the droplet of cells. All together, these results indicate previously unknown response capabilities arising from the magnetic sensing systems of AMB-1 cells. These responses could enable them to cope with magnetic disturbances that could in turn potentially inhibit their efficient search for nutrients. PMID:25478682

  16. Enhancing the stability and ecological safety of mass-reared transgenic strains for field release by redundant conditional lethality systems.

    Science.gov (United States)

    Handler, Alfred M

    2016-04-01

    The genetic manipulation of agriculturally important insects now allows the development of genetic sexing and male sterility systems for more highly efficient biologically-based population control programs, most notably the Sterile Insect Technique (SIT), for both plant and animal insect pests. Tetracycline-suppressible (Tet-off) conditional lethal systems may function together so that transgenic strains will be viable and fertile on a tetracycline-containing diet, but female-lethal and male sterile in tetracycline-free conditions. This would allow their most efficacious use in a unified system for sterile male-only production for SIT. A critical consideration for the field release of such transgenic insect strains, however, is a determination of the frequency and genetic basis of lethality revertant survival. This will provide knowledge essential to evaluating the genetic stability of the lethality system, its environmental safety, and provide the basis for modifications ensuring optimal efficacy. For Tet-off lethal survival determinations, development of large-scale screening protocols should also allow the testing of these modifications, and test the ability of other conditional lethal systems to fully suppress propagation of rare Tet-off survivors. If a dominant temperature sensitive (DTS) pupal lethality system proves efficient for secondary lethality in Drosophila, it may provide the safeguard needed to support the release of sexing/sterility strains, and potentially, the release of unisex lethality strains as a form of genetic male sterility. Should the DTS Prosβ2(1) mutation prove effective for redundant lethality, its high level of structural and functional conservation should allow host-specific cognates to be created for a wide range of insect species. PMID:26097098

  17. Random amplified polymorphic DNA assay is less discriminant than pulsed-field gel electrophoresis for typing strains of methicillin-resistant Staphylococcus aureus.

    Science.gov (United States)

    Saulnier, P; Bourneix, C; Prévost, G; Andremont, A

    1993-04-01

    Twenty-six strains of methicillin-resistant Staphylococcus aureus with different pulsed-field gel electrophoresis fingerprints were tested by random amplified polymorphic DNA assay with three primers, resulting in 15 to 20 different random amplified polymorphic DNA fingerprints. By summing the results for the three primers, the number of different fingerprints increased to 25, but two strains could not be differentiated. We conclude that pulsed-field gel electrophoresis remains the best method of typing methicillin-resistant S. aureus strains. PMID:8463406

  18. Ability to differentiate between cp and ncp BVDV by microarrays: towards an application in clinical veterinary medicine?

    Science.gov (United States)

    Werling, Dirk; Ruryk, Andriy; Heaney, Judith; Moeller, Eva; Brownlie, Joe

    2005-10-18

    Microarray expression profiling provides a comprehensive portrait of the transcriptional world enabling us to view the organism as a 'system' that is more than the sum of its parts. The vigilance of cells to environmental change, the alacrity of the transcriptional response, the short half-life of cellular mRNA and the genome-scale nature of the investigation collectively explain the power of this method. These same features pose the most significant experimental design and execution issues which, unless surmounted, predictably generate a distorted image of the transcriptome. Conversely, the expression profile of a properly conceived and conducted microarray experiment can be used for hypothesis testing: disclosure of the metabolic and biosynthetic pathways that underlie adaptation of the organism to infectious processes; the identification of co-ordinately regulated genes; the regulatory circuits and signal transduction systems that mediate the adaptive response; and temporal features of developmental programmes. The study of viral pathogenesis by microarray expression profiling poses special challenges and opportunities. Although the technical hurdles are many, obtaining expression profiles of an organism growing in tissue will probably reveal strategies for growth and survival of the virus in the host's cells. Here, we show data obtained using a tailored microarray system based on synthetic polynucleotides derived from human sequences (SIRS-Lab GmbH, Jena, Germany) to study the effect of cytopathogenic (cpe) and non-cytopathogenic (ncp) bovine viral diarrhoea virus (BVDV) infection of bovine macrophages, focusing on intracellular signalling molecules. Of the 575 genes present on the array, more than 70% showed a reaction with the oligonuleotides spotted on the array, and 26 genes were differentially expressed comparing cDNA derived from cpe and ncp infected cells. These data will help to further understand our knowledge regarding BVDV infection, and will

  19. Inter-dot strain field effect on the optoelectronic properties of realistic InP lateral quantum-dot molecules

    International Nuclear Information System (INIS)

    We report on numerical simulations of InP surface lateral quantum-dot molecules on In0.48Ga0.52 P buffer, using a model strictly derived by experimental results by extrapolation of the molecules shape from atomic force microscopy images. Our study has been inspired by the comparison of a photoluminescence spectrum of a high-density InP surface quantum dot sample with a numerical ensemble average given by a weighted sum of simulated single quantum-dot spectra. A lack of experimental optical response from the smaller dots of the sample is found to be due to strong inter-dot strain fields, which influence the optoelectronic properties of lateral quantum-dot molecules. Continuum electromechanical, k→·p→ bandstructure, and optical calculations are presented for two different molecules, the first composed of two dots of nearly identical dimensions (homonuclear), the second of two dots with rather different sizes (heteronuclear). We show that in the homonuclear molecule the hydrostatic strain raises a potential barrier for the electrons in the connection zone between the dots, while conversely the holes do not experience any barrier, which considerably increases the coupling. Results for the heteronuclear molecule show instead that its dots do not appear as two separate and distinguishable structures, but as a single large dot, and no optical emission is observed in the range of higher energies where the smaller dot is supposed to emit. We believe that in samples of such a high density the smaller dots result as practically incorporated into bigger molecular structures, an effect strongly enforced by the inter-dot strain fields, and consequently it is not possible to experimentally obtain a separate optical emission from the smaller dots

  20. Inter-dot strain field effect on the optoelectronic properties of realistic InP lateral quantum-dot molecules

    Energy Technology Data Exchange (ETDEWEB)

    Barettin, Daniele, E-mail: Daniele.Barettin@uniroma2.it; Auf der Maur, Matthias [Department of Electronic Engineering, University of Rome “Tor Vergata,” Via del Politecnico 1, 00133, Rome (Italy); De Angelis, Roberta; Prosposito, Paolo; Casalboni, Mauro [Department of Industrial Engineering, University of Rome Tor Vergata, Via del Politecnico 1 00133 Rome, Italy and INSTM, Unitá di ricerca dell' Universitá di Roma “Tor Vergata,” Via della Ricerca Scientifica 1, 00133, Rome (Italy); Pecchia, Alessandro [CNR-ISMN, via Salaria Km. 29.300, 00017 Monterotondo, Rome (Italy)

    2015-03-07

    We report on numerical simulations of InP surface lateral quantum-dot molecules on In{sub 0.48}Ga{sub 0.52 }P buffer, using a model strictly derived by experimental results by extrapolation of the molecules shape from atomic force microscopy images. Our study has been inspired by the comparison of a photoluminescence spectrum of a high-density InP surface quantum dot sample with a numerical ensemble average given by a weighted sum of simulated single quantum-dot spectra. A lack of experimental optical response from the smaller dots of the sample is found to be due to strong inter-dot strain fields, which influence the optoelectronic properties of lateral quantum-dot molecules. Continuum electromechanical, k{sup →}·p{sup →} bandstructure, and optical calculations are presented for two different molecules, the first composed of two dots of nearly identical dimensions (homonuclear), the second of two dots with rather different sizes (heteronuclear). We show that in the homonuclear molecule the hydrostatic strain raises a potential barrier for the electrons in the connection zone between the dots, while conversely the holes do not experience any barrier, which considerably increases the coupling. Results for the heteronuclear molecule show instead that its dots do not appear as two separate and distinguishable structures, but as a single large dot, and no optical emission is observed in the range of higher energies where the smaller dot is supposed to emit. We believe that in samples of such a high density the smaller dots result as practically incorporated into bigger molecular structures, an effect strongly enforced by the inter-dot strain fields, and consequently it is not possible to experimentally obtain a separate optical emission from the smaller dots.

  1. Identification of nif genes in N2-fixing bacterial strains isolated from rice fields along the Yangtze River Plain.

    Science.gov (United States)

    Xie, Guang Hui; Cui, Zongjun; Yu, Jun; Yan, Jing; Hai, Weili; Steinberger, Yosef

    2006-01-01

    The aim of this research was to identify nifH and nifHDKYE ' genes in twenty strains of N2-fixing heterotrophic bacteria isolated from rice fields in the Yangtze River Plain. Southern hybridization of the total DNA from each strain was performed with the Klebsiella pneumoniae nifHDKYE ' gene probe (6.2 kb Eco RI fragment from pSA30) and the Azospirillum brasilense nifH gene probe (0.6 kb Eco RI-Hin dIII fragment from pHU8). We found that Eco RI fragments of total DNA from Aeromonas hydrophila HY2, Bacillus azotoformans FD, Bacillus licheniformis NCH1, NCH5, WH4, Bacillus brevis NC2, Bacillus pumilus NC12, Bacillus cereus NCH2, Citrobacter freundii HY5, HY9, Derxia gummosa HZ5, Pseudomonas mendocina HZ1 and Pseudomonas pseudoalcaligenes WH3 were positively hybridized with both of the probes. Agrobacterium radiobacter HY17, Corynebacterium sp. HY12, YZ and Pseudomonas sp. HY11 had Eco RI fragments hybridized with the K. pneumoniae nifHDKYE ' gene probe. An Eco RI fragment of total DNA from Bacillus megaterium YY4 was positively hybridized to the A. brasilense nifH gene probe. No hybridization sign was found in the total DNA fragments from Alcaligenes cupidus YY6 and Corynebacterium sp. NC11 hybridized with either of the gene probes. The data provide the number and size of EcoRI fragments of the total DNA hybridized with the nif gene probes for these strains of rarely studied species, suggesting additional evidence for N2 fixing and nif gene diversity of N2-fixing bacteria in rice fields along the Yangtze River Plain.

  2. Field longevity of a fluorescent protein marker in an engineered strain of the pink bollworm, Pectinophora gossypiella (Saunders.

    Directory of Open Access Journals (Sweden)

    Michelle Walters

    Full Text Available The cotton pest, pink bollworm (Pectinophora gossypiella (Saunders, is a significant pest in most cotton-growing areas around the world. In southwestern USA and northern Mexico, pink bollworm is the target of the sterile insect technique (SIT, which relies on the mass-release of sterile pink bollworm adults to over-flood the wild population and thereby reduce it over time. Sterile moths reared for release are currently marked with a dye provided in their larval diet. There are concerns, however, that this marker fails from time to time, leading to sterile moths being misidentified in monitoring traps as wild moths. This can lead to expensive reactionary releases of sterile moths. We have developed a genetically marked strain that is engineered to express a fluorescent protein, DsRed2, which is easily screened under a specialised microscope. In order to test this marker under field conditions, we placed wild-type and genetically marked moths on traps and placed them in field cages. The moths were then screened, in a double-blind fashion, for DsRed2 fluorescence at regular intervals to determine marker reliability over time. The marker was shown to be robust in very high temperatures and generally proved reliable for a week or longer. More importantly, genotyping of moths on traps by PCR screening of the moths was 100% correct. Our findings indicate that this strain--and fluorescent protein markers in general--could make a valuable contribution to SIT.

  3. Monitoring chronic infection with a field strain of Aleutian mink disease virus

    DEFF Research Database (Denmark)

    Jensen, Trine Hammer; Hammer, Anne Sofie; Chriél, Mariann

    2014-01-01

    Aleutian mink disease virus (AMDV) readily spread within farmed mink and causes chronic infections with significant impacts for welfare and economy. In the present study a currently circulating Danish AMDV strain was used to induce chronic experimental infection of farmed mink.PCR was used...... to detect viral DNA in full blood, organs, faeces and oro-nasal swabs weekly for the first 8 weeks and then biweekly for another 16 weeks after AMDV challenge inoculation of wild type mink. The mink (n=29) was infected and seroconverted 2–3 weeks after AMDV inoculation and AMDV antibodies persisted during...... the maximum experimental period of 24 weeks. Viraemia and faecal excretion of viral DNA was detected in the mink (n=29) at various and intermittent time intervals. Excretion of viral DNA in oro-nasal swabs was detected for 1–8 weeks in 21 mink. This highlights the risk of transmitting AMDV between infected...

  4. Manipulation of magnetic phase separation and orbital occupancy in manganites by strain engineering and electric field

    Science.gov (United States)

    Cui, Bin; Song, Cheng; Pan, Feng; Key Laboratory of Advanced Materials (MOE) Team

    2015-03-01

    The modification of electronic phases in correlated oxides is one of the core issues of condensed matter. We report the reversible control of ferromagnetic phase transition in manganite films by ionic liquid gating, replicating the La1-xSrxMnO3 (LSMO) phase diagram. The formation and annihilation of an insulating and magnetically hard phase in the soft magnetic matrix, which randomly nucleates and grows across the film, is directly observed under different gate voltages (VG) . The realization of reversible metal-insulator transition in colossal magnetoresistance materials can lead to the development of four-state memories. The orbital occupancy and magnetic anisotropy of LSMO films are manipulated by VG in a reversible and quantitative manner. Positive and negative VG increases and reduces the occupancy of the orbital and magnetic anisotropy that were initially favored by strain (irrespective of tensile and compressive), respectively. This finding fills in the blank of electrical manipulation of four degrees of freedom in correlated system.

  5. Structural change and straining in Fe-Pd polycrystals by magnetic field

    Energy Technology Data Exchange (ETDEWEB)

    Wada Taishi; Liang Yuanchang; Kato, Hiroyuki; Tagawa, Tetsuya; Taya, Minoru; Mori, T

    2003-11-25

    The effect of a magnetic field on martensite structures in Fe-30 and -30.5at.% Pd has been studied using optical and electron (TEM) microscopy. No appreciable change to the martensite structure is observed with optical microscopy when a magnetic field of {approx}8x10{sup 5} A m{sup -1} is applied to a sample in the fully martensite state. The fractions of elementary martensite units (Bain correspondence variants--BCVs), existing as alternately stacked twins in a martensite plate and observed by electron microscopy, remain almost the same whether a TEM foil is under practically no magnetic field or under a field of more than {approx}8x10{sup 5} A m{sup -1}. Fe-Pd is more difficult to magnetically saturate in the martensite state than in the austenite state, even though the saturation magnetization is only slightly smaller in the former state. Hysteresis in a magnetization-magnetic field relationship is small. From these observations, it is concluded that the magnetization in the martensite state is mostly achieved by rotation of the magnetization vector, with hardly any contribution from the movement of magnetic domain walls. This is reasoned using the argument that the interfaces of BCVs offer large resistance to the movement of magnetic domain walls.

  6. Analysis of viremia and transplacental transmission of field and rescued strains of BTV-2 and BTV-8 following inoculation of pregnant sheep

    DEFF Research Database (Denmark)

    Rasmussen, Lasse Dam; Savini, Giovanni; Palmarini, Massimo;

    2012-01-01

    viruses by making defined reassortants. To date, only a few experiments have investigated whether field and rescued virus strains behave similarly in vivo. Methods Twenty-four sheep (in 4 groups of 6) were inoculated (s.c.) with 4 strains of BTV in late pregnancy (approx. 1 month before lambing......). The viruses used were: BTV-2 wt (Italian field strain), BTV-2 (rescued), BTV-8 wt (field strain from the Netherlands) and BTV-8 (rescued). Four sheep were non-inoculated controls. Blood samples from the sheep were tested frequently for viremia and anti-BTV antibodies (by ELISA) in the period until lambing...... have being tested for the presence of anti-BTV antibodies and for virus (RT-qPCR). Results All inoculated animals developed viremia. The viremia was significantly higher at all sampling points following inoculation (panimals inoculated with BTV-2 wt compared...

  7. Large electric-field control of perpendicular magnetic anisotropy in strained [Co/Ni] / PZT heterostructures

    Science.gov (United States)

    Gopman, Daniel; Dennis, Cindi; Chen, P. J.; Iunin, Yury; Shull, Robert

    We present a piezoelectric/ferromagnetic heterostructure with PMA - a Co/Ni multilayer sputtered directly onto a Pb(Zr,Ti)O3 (PZT) substrate. Chemical-mechanical polishing was used to reduce the roughness of PZT plates to below 2 nm rms, enabling optimal magnetoelectric coupling via the direct interface between PZT and sputtered Co/Ni films with large PMA (Keff = (95 +/-9 kJ/m3)) . We grew the following layer stack: Ta(3)/Pt(2)/[Co(0.15)/Ni(0.6)]x4/Co(0.15)/Pt(2)/Ta(3); numbers in parentheses indicate thicknesses in nm. Applied electric fields up to +/- 2 MV/m to the PZT generated 0.05% in-plane compression in the Co/Ni multilayer, enabling a large electric-field reduction of the PMA (ΔKeff >= 103 J/m3) and of the coercive field (35%). Our results demonstrate that: (i) heterostructures combining PZT and [Co/Ni] exhibit larger PMA (Keff ~105 J/m3) than previous magnetoelectric heterostructures based on Co/Pt and CoFeB, enabling thermally stable hybrid magnetoelectric/spintronic devices only tens of nm in diameter and (ii) electric-field control of the PMA is promising for more energy efficient switching of spintronic devices.

  8. Effects of phosphorus fertilizer rate and Pseudomonas fluorescens strain on field pea (Pisum sativum subsp. arvense (L. Asch. growth and yield

    Directory of Open Access Journals (Sweden)

    Bahram SALEHI

    2015-11-01

    Full Text Available A field experiment was conducted at Rezvanshahr, Guilan province, Iran, to evaluate the effects of phosphorus fertilizer rate and Pseudomonas fluorescens strains on growth and yield of field pea (Pisum sativum L.. The experimental design was a randomized complete block in a factorial arrangement with three replicates. Factors were phosphorus fertilizer rates (0, 25, 50, 75, and 100 kg P2O5 ha-1 as triple superphosphate, and seed inoculation with P. florescens strains [control (non-inoculated, inoculated with strain R41, and strain R187. Analysis of variance showed that plant height, seed yield, pod number per m2, 100-seed weight, biological yield, harvest index, and leaf P concentration were significantly influenced by phosphorus fertilizer rate and P. florescens strain. At the same time, phosphorus fertilizer rate × P. fluorescens strain interaction was significant only for 100-seed weight. On the other hand, seed number per pod was significantly affected neither by phosphorus fertilizer rate nor by pseudomonas strains. Result showed that seed yield was significantly increased from 1099 ± 67 to 1898 ± 118 kg ha-1 as P2O5 application rate increased from 0 to 75 kg ha-1, and thereafter relatively remained constant. There was no significant difference in seed yield between plants raised from inoculated seeds with P. fluorescens, strain R187 (1664 ± 97 kg ha-1 and those raised from inoculated seeds with P. fluorescens, strain R41 (1669 ± 104 kg ha-1. At the same time, plants raised from inoculated seeds with P. fluorescens (both strains produced greater grain yield compared to those raised from uninoculated seeds (1370 ± 80 kg ha-1. Based on the results of this study, P2O5 application at the rate of 75 kg ha-1 and inoculation with pseudomonas bacteria are recommended for obtaining the greatest seed yield in field pea.

  9. Wave Phase-Sensitive Transformation of 3d-Straining of Mechanical Fields

    Science.gov (United States)

    Smirnov, I. N.; Speranskiy, A. A.

    2015-11-01

    It is the area of research of oscillatory processes in elastic mechanical systems. Technical result of innovation is creation of spectral set of multidimensional images which reflect time-correlated three-dimensional vector parameters of metrological, and\\or estimated, and\\or design parameters of oscillations in mechanical systems. Reconstructed images of different dimensionality integrated in various combinations depending on their objective function can be used as homeostatic profile or cybernetic image of oscillatory processes in mechanical systems for an objective estimation of current operational conditions in real time. The innovation can be widely used to enhance the efficiency of monitoring and research of oscillation processes in mechanical systems (objects) in construction, mechanical engineering, acoustics, etc. Concept method of vector vibrometry based on application of vector 3D phase- sensitive vibro-transducers permits unique evaluation of real stressed-strained states of power aggregates and loaded constructions and opens fundamental innovation opportunities: conduct of continuous (on-line regime) reliable monitoring of turboagregates of electrical machines, compressor installations, bases, supports, pipe-lines and other objects subjected to damaging effect of vibrations; control of operational safety of technical systems at all the stages of life cycle including design, test production, tuning, testing, operational use, repairs and resource enlargement; creation of vibro-diagnostic systems of authentic non-destructive control of anisotropic characteristics of materials resistance of power aggregates and loaded constructions under outer effects and operational flaws. The described technology is revolutionary, universal and common for all branches of engineering industry and construction building objects.

  10. Photovoltaic and magnetic properties of BiFeO3/TiO2 heterostructures under epitaxial strain and an electric field

    International Nuclear Information System (INIS)

    First-principles calculations show that the photovoltaic effect of the BiFeO3/TiO2 heterostructures in the visible-light region can be improved by applying epitaxial strain and an electric field. The multi-field coupling effect in the interface makes the heterojunction an intriguing candidate towards fabricating the multifunctional photoelectric devices, and the microscopic mechanism involved is attributed to the spin transfer and charge rearrangement between the Fe 3d and O 2p orbitals in the vicinity of the interface. - Highlights: • The photovoltaic effect in BiFeO3/TiO2 can be tuned by strain and an electric field. • The magnetization in the interface is reversed by strain. • There exists multi-field coupling in the interface

  11. Photovoltaic and magnetic properties of BiFeO{sub 3}/TiO{sub 2} heterostructures under epitaxial strain and an electric field

    Energy Technology Data Exchange (ETDEWEB)

    Feng, Hong-Jian, E-mail: hjfeng@nwu.edu.cn

    2015-03-01

    First-principles calculations show that the photovoltaic effect of the BiFeO{sub 3}/TiO{sub 2} heterostructures in the visible-light region can be improved by applying epitaxial strain and an electric field. The multi-field coupling effect in the interface makes the heterojunction an intriguing candidate towards fabricating the multifunctional photoelectric devices, and the microscopic mechanism involved is attributed to the spin transfer and charge rearrangement between the Fe 3d and O 2p orbitals in the vicinity of the interface. - Highlights: • The photovoltaic effect in BiFeO{sub 3}/TiO{sub 2} can be tuned by strain and an electric field. • The magnetization in the interface is reversed by strain. • There exists multi-field coupling in the interface.

  12. A model for the prediction of Nb sub 3 Sn critical current as a function of field, temperature, strain, and radiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Summers, L.T.; Guinan, M.W.; Miller, J.R.; Hahn, P.A. (Lawrence Livermore National Lab., CA (United States))

    1991-03-01

    This paper reports on conductors designed for fusion machines which operate on high fields, under large mechanical loads, and in a high neutron flux. Present designs favor the use of Nb{sub 3}Sn with force-cooling by supercritical-helium to extract large nuclear and ac loss heat loads. Consequently, the magnet designer must have a good knowledge of the critical current of the superconductor as a function of field, strain, temperature, and radiation damage. Expanding on work by Hampshire, et al, and Ekin, combined with radiation-damage studies of Nb{sub 3}Sn, we express the critical field (B{sub c20}) as function of temperature, strain and damage energy (E{sub d}). Similarly, the zero-field critical temperature (T{sub c0}) is expressed as a function of strain and damage energy.

  13. Tunnel field-effect transistors with germanium/strained-silicon hetero-junctions for low power applications

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Minsoo, E-mail: minsoo@mosfet.t.u-tokyo.ac.jp; Kim, Younghyun; Yokoyama, Masafumi; Nakane, Ryosho; Kim, SangHyeon; Takenaka, Mitsuru; Takagi, Shinichi

    2014-04-30

    We have studied a simple structure n-channel tunnel field-effect transistor with a pure-Ge/strained-Si hetero-junction. The device operation was demonstrated for the devices fabricated by combining epitaxially-grown Ge on strained-silicon-on-insulator substrates. Atomic-layer-deposition-Al{sub 2}O{sub 3}-based gate stacks were formed with electron cyclotron resonance plasma post oxidation to ensure the high quality metal–oxide–semiconductor interface between the high-k insulator and Ge. While the gate leakage current and drain current saturation are well controlled, relatively higher minimum subthreshold swing of 125 mV/dec and lower I{sub ON}/I{sub OFF} ratio of 10{sup 3}–10{sup 4} were obtained. It is expected that these device characteristics can be improved by further process optimization. - Highlights: • Layer by layer growth of Ge • Uniform interface between Ge and the insulator • Gate leakage current and drain current saturation seem to be well controlled. • The output characteristics show good saturation.

  14. The demonstration of nonlinear analytic model for the strain field induced by thermal copper filled TSVs (through silicon via

    Directory of Open Access Journals (Sweden)

    M. H. Liao

    2013-08-01

    Full Text Available The thermo-elastic strain is induced by through silicon vias (TSV due to the difference of thermal expansion coefficients between the copper (∼18 ppm/ °C and silicon (∼2.8 ppm/ °C when the structure is exposed to a thermal ramp budget in the three dimensional integrated circuit (3DIC process. These thermal expansion stresses are high enough to introduce the delamination on the interfaces between the copper, silicon, and isolated dielectric. A compact analytic model for the strain field induced by different layouts of thermal copper filled TSVs with the linear superposition principle is found to have large errors due to the strong stress interaction between TSVs. In this work, a nonlinear stress analytic model with different TSV layouts is demonstrated by the finite element method and the analysis of the Mohr's circle. The characteristics of stress are also measured by the atomic force microscope-raman technique with nanometer level space resolution. The change of the electron mobility with the consideration of this nonlinear stress model for the strong interactions between TSVs is ∼2–6% smaller in comparison with those from the consideration of the linear stress superposition principle only.

  15. Microhardness and Strain Field Characterization of Self-Reacting Friction Stir and Plug Welds of Dissimilar Aluminum Alloys

    Science.gov (United States)

    Horton, Karla Renee

    2011-01-01

    Friction stir welding (FSW) is a solid state welding process with potential advantages for aerospace and automotive industries dealing with light alloys. Self-reacting friction stir welding (SR-FSW) is one variation of the FSW process being developed at the National Aeronautics and Space Administration (NASA) for use in the fabrication of propellant tanks. Friction plug welding is used to seal the exit hole that remains in a circumferential SR-FSW. This work reports on material properties and strain patterns developed in a SR-FSW with a friction plug weld. Specifically, this study examines the behavior of a SR-FSW formed between an AA 2014-T6 plate on the advancing side and an AA 2219-T87 plate on the retreating side and a SR-FSW (AA 2014-T6 to AA 2219-T87) with a 2219-T87 plug weld. This study presents the results of a characterization of the micro-hardness, joint strength, and strain field characterization of SR-FSW and FPW joints tested at room temperature and cryogenic temperatures.

  16. Carrier transport in strained N-channel field effect transistors with channel proximate silicon-carbon source/drain stressors

    Science.gov (United States)

    Koh, Shao-Ming; Samudra, Ganesh S.; Yeo, Yee-Chia

    2010-07-01

    We investigate the carrier transport characteristics in strained n-channel metal-oxide-semiconductor field effect transistors (nFETs) with embedded silicon-carbon (Si:C) source/drain (S/D) stressors formed in close proximity to the channel, taking parasitic resistance into account in the extraction of carrier transport parameters. While bringing the Si:C S/D stressors closer to the channel improves their effectiveness in imparting tensile strain to the channel, degradation in ballistic efficiency due to increased carrier scattering is observed. Fortunately, this is more than compensated by an increase in the carrier injection velocity vinj. For channel-proximate (CP) Si:C S/D nFETs with gate lengths ranging from 100 to 130 nm, a ˜10% drive current IDsat enhancement is observed with a ˜15% improvement in vinj. These findings clarified experimentally that in addition to mobility enhancement, vinj improvement also plays a significant role in the IDsat enhancement achieved by CP Si:C S/D nFETs.

  17. Temperature dependence of the magnetic-field-induced strain of NiMnGa in the presence of an acoustic drive

    Science.gov (United States)

    Peterson, Bradley W.; Allen, Samuel M.; O'Handley, Robert C.

    2008-08-01

    A small amplitude acoustic signal was applied to a Ni-Mn-Ga single crystal. The effect of the acoustic signal in enhancing the magnetic-field-induced strain was measured as a function of temperature over the range of 1-35°C below the austenite-start temperature. Strain output was found to decrease with decreasing temperature as a result of lowered twin-boundary mobility. The combination of a piezoelectric drive with the magnetic drive yields an improvement in strain response for all temperatures investigated; however, the piezoenhanced, field-induced strain is maximized at 12.5°C, where ∂ɛ /∂T is maximum.

  18. Observation of nano-indent induced strain fields and dislocation generation in silicon wafers using micro-Raman spectroscopy and white beam X-ray topography

    Energy Technology Data Exchange (ETDEWEB)

    Allen, D., E-mail: david.allen2@mail.dcu.i [Dublin City University, Research Institute for Networks and Communications Engineering, Dublin 9 (Ireland); Wittge, J.; Zlotos, A. [University Freiburg, Kristallographie, Gewowiss. Institut, Freiburg (Germany); Gorostegui-Colinas, E.; Garagorri, J. [Centro de Estudios e Investigaciones Tecnicas de Gipuzkoa, CEIT, San Sebastian (Spain); McNally, P.J. [Dublin City University, Research Institute for Networks and Communications Engineering, Dublin 9 (Ireland); Danilewsky, A.N. [University Freiburg, Kristallographie, Gewowiss. Institut, Freiburg (Germany); Elizalde, M.R. [Centro de Estudios e Investigaciones Tecnicas de Gipuzkoa, CEIT, San Sebastian (Spain)

    2010-02-15

    In the semiconductor manufacturing industry, wafer handling introduces micro-cracks at the wafer edge. During heat treatment these can produce larger, long range cracks in the wafer which can cause wafer breakage during manufacture. Two complimentary techniques, micro-Raman spectroscopy (muRS) and White Beam Synchrotron X-ray Topography (WBSXRT) were employed to study both the micro-cracks and the associated strain fields produced by nano-indentations in Si wafers, which were used as a means of introducing controlled strain in the wafers. It is shown that both the spatial lateral and depth distribution of these long range strain fields are relatively isotropic in nature. The Raman spectra suggest the presence of a region under tensile strain beneath the indents, which can indicate a crack beneath the indent and the data strongly suggests that there exists a minimum critical applied load below which cracking will not initiate.

  19. Nanoscale strain distributions in embedded SiGe semiconductor devices revealed by precession electron diffraction and dual lens dark field electron holography

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Y. Y. [IBM Micro-Electronics Division, 2070 Route 52, Hopewell Junction, New York 12570 (United States); Cooper, D.; Bernier, N. [University Grenoble Alpes, F-38000 Grenoble (France); CEA, LETI, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Rouviere, J. [University Grenoble Alpes, F-38000 Grenoble (France); CEA, INAC, MINATEC Campus, 17 rue des Martyrs, 38054 Grenoble Cedex 9 (France); Murray, C. E.; Bruley, J. [IBM T. J. Watson Research Center, 1101 Kitchawan Road, Route 134, Yorktown Heights, New York 10598 (United States)

    2015-01-26

    The detailed strain distributions produced by embedded SiGe stressor structures are measured at high spatial resolution with high precision, with dual lens dark field electron holography and precession electron diffraction. Shear strain and lattice rotation within the crystalline lattice are observed at the boundaries between the SiGe and Si regions. The experimental results are compared to micromechanical modeling simulations to understand the mechanisms of elastic relaxation on all the modes of deformation at a sub-micron length scale.

  20. Study on the characteristics of rock failure strain and acoustic emission field for two parallelling faults with the same slip direction including asperities

    Institute of Scientific and Technical Information of China (English)

    焦明若; 张国民; 马胜利; 马宏生

    2002-01-01

    By dealing with strain and acoustic emission (AE) data for two parallelling faults's instability and failure with the same slip direction including asperities, the temporal-spatial evolution of strain and AE field distribution on the asperity of parallelling faults is analyzed. Furthermore the failure process of asperities and interaction among the asperities, i.e., positive and negative seismicity are discussed. Results show that instability and failure for the parallelling faults is a kind of negative seismicity.

  1. Comparison of the breadth and complexity of bovine viral diarrhea (BVDV) populations circulating in 34 persistently infected cattle generated in one outbreak.

    Science.gov (United States)

    Ridpath, J F; Bayles, D O; Neill, J D; Falkenberg, S M; Bauermann, F V; Holler, L; Braun, L J; Young, D B; Kane, S E; Chase, C C L

    2015-11-01

    Exposure to bovine viral diarrhea viruses (BVDV) results in acute and persistent infections. Persistent infections result from in utero exposure during the first trimester of gestation. Clinical presentation, in persistently infected cattle (PI), is highly variable. The reasons for this variation is largely unknown. The BVDV circulating in PI exist as quasispecies (swarms of individual viruses). An outbreak resulting in 34 PI cattle presented an opportunity to compare a large number of PI׳s. Methods were developed to compare the circulating viral populations within PI animals. It was found that PI animals generated in the same outbreak carry circulating viral populations that differ widely in size and diversity. Further, it was demonstrated that variation in PI viral populations could be used as a quantifiable phenotype. This observation makes it possible to test the correlation of this phenotype to other phenotypes such as growth rate, congenital defects, viral shed and cytokine expression.

  2. Anticorpos neutralizantes contra o vírus da Diarréia Viral Bovina (BVDV: comparação entre um imunógeno experimental atenuado e três vacinas comerciais inativadas Vaccination-induced neutralizing antibodies against bovine viral diarrhea virus (BVDV: comparison between an experimental modified-live vaccine and three comercial inactivated vaccines

    Directory of Open Access Journals (Sweden)

    Marcelo de Lima

    2005-02-01

    Full Text Available Os títulos e duração de anticorpos neutralizantes contra o vírus da Diarréia Viral Bovina (BVDV induzidos por uma vacina experimental atenuada (vacina A: dose única foram comparados com os induzidos por três vacinas comerciais inativadas (B, C e D: duas doses com intervalo de 30 dias. Trinta dias após a vacinação (vacina A ou após a segunda dose (vacinas B, C e D, anticorpos neutralizantes contra o BVDV-1 foram detectados em todos os animais (12/12 do grupo A (título médio geométrico GMT=1612,7; em 32 de 36 animais do grupo B (GMT=14,3; 22 de 28 do grupo C (GMT=25,1; e em 16 de 30 do grupo D (GMT=40,0. Anticorpos frente ao BVDV-2 foram detectados em todos os animais do grupo A (GMT=151,0; em 27 de 36 do grupo B (GMT=10,0; 12 de 28 do grupo C (GMT=11,5 e em 10 de 30 animais do grupo D (GMT=10,0. No dia 180 após a vacinação, o número de animais que ainda apresentava anticorpos contra o BVDV-1 e os GMTs para cada grupo foram: vacina A (12/12, GMT=905,0; vacina B (30/36, GMT=28,3; vacina C (20/28, GMT=28,3; vacina D (14/30, GMT=16,1; e contra o BVDV-2 foram: vacina A (12/12, GMT=56,6; vacina B (18/36, GMT=16,8; vacina C (10/28, GMT=21,6 e vacina D (6/30, GMT=16,1. Os títulos médios (GMTs induzidos pela vacina A foram significativamente superiores aos demais, tanto para o BVDV-1 (PThe titers and duration of neutralizing antibodies against bovine viral diarrhea virus (BVDV induced by an experimental attenuated vaccine (vaccine A: one dose were compared to those induced by three commercial inactivated ones (B, C and D: two doses at a 30 day interval. Thirty days after vaccination (vaccine A or the second dose (vaccines B, C and D, neutralizing antibodies to BVDV-1 were detected in all calves (12/12 from group A (mean geometric titer GMT=1612.7; in 32 out of 36 from group B (GMT=14.3; 22/28 from group C (GMT=25.1; 16/30 from group D (GMT=40.0. Antibodies reacting with BVDV-2 were detected in all animals from group A (GMT=151.0; 27

  3. How accurately can subject-specific finite element models predict strains and strength of human femora? Investigation using full-field measurements.

    Science.gov (United States)

    Grassi, Lorenzo; Väänänen, Sami P; Ristinmaa, Matti; Jurvelin, Jukka S; Isaksson, Hanna

    2016-03-21

    Subject-specific finite element models have been proposed as a tool to improve fracture risk assessment in individuals. A thorough laboratory validation against experimental data is required before introducing such models in clinical practice. Results from digital image correlation can provide full-field strain distribution over the specimen surface during in vitro test, instead of at a few pre-defined locations as with strain gauges. The aim of this study was to validate finite element models of human femora against experimental data from three cadaver femora, both in terms of femoral strength and of the full-field strain distribution collected with digital image correlation. The results showed a high accuracy between predicted and measured principal strains (R(2)=0.93, RMSE=10%, 1600 validated data points per specimen). Femoral strength was predicted using a rate dependent material model with specific strain limit values for yield and failure. This provided an accurate prediction (strain accuracy was comparable to that obtained in state-of-the-art studies which validated their prediction accuracy against 10-16 strain gauge measurements. Fracture force was accurately predicted, with the predicted failure location being very close to the experimental fracture rim. Despite the low sample size and the single loading condition tested, the present combined numerical-experimental method showed that finite element models can predict femoral strength by providing a thorough description of the local bone mechanical response. PMID:26944687

  4. Modulation of metal-insulator transitions by field-controlled strain in NdNiO3/SrTiO3/PMN-PT (001) heterostructures

    Science.gov (United States)

    Heo, Seungyang; Oh, Chadol; Eom, Man Jin; Kim, Jun Sung; Ryu, Jungho; Son, Junwoo; Jang, Hyun Myung

    2016-02-01

    The band width control through external stress has been demonstrated as a useful knob to modulate metal-insulator transition (MIT) in RNiO3 as a prototype correlated materials. In particular, lattice mismatch strain using different substrates have been widely utilized to investigate the effect of strain on transition temperature so far but the results were inconsistent in the previous literatures. Here, we demonstrate dynamic modulation of MIT based on electric field-controlled pure strain in high-quality NdNiO3 (NNO) thin films utilizing converse-piezoelectric effect of (001)-cut - (PMN-PT) single crystal substrates. Despite the difficulty in the NNO growth on rough PMN-PT substrates, the structural quality of NNO thin films has been significantly improved by inserting SrTiO3 (STO) buffer layers. Interestingly, the MIT temperature in NNO is downward shifted by ~3.3 K in response of 0.25% in-plane compressive strain, which indicates less effective TMI modulation of field-induced strain than substrate-induced strain. This study provides not only scientific insights on band-width control of correlated materials using pure strain but also potentials for energy-efficient electronic devices.

  5. High-field magnetotransport in strained La{sub 2-x}Sr{sub x}CuO{sub 4} films

    Energy Technology Data Exchange (ETDEWEB)

    Sekitani, Tsuyoshi; Sato, Hisashi; Naito, Michio; Miura, Noboru

    2003-05-15

    We present the transport properties of the low-temperature normal-state for strained La{sub 2-x}Sr{sub x}CuO{sub 4} (LSCO) films achieved by suppressing superconductivity with high magnetic fields up to 50 T. Systematic measurements were performed on six MBE grown films with three different doping levels (underdope, optimumdope, and overdope) and also with either compressive or tensile epitaxial strain. The results showed that the low-temperature semiconducting upturn observed in under- or optimum-doped LSCO bulk single crystals is significantly suppressed by in-plane compressive strain.

  6. Mechanical noise limit of a strain coupled magneto(elasto)electric sensor operating under a magnetic or an electric field modulation

    OpenAIRE

    X. Zhuang; Sing, M. Lam Chok; Lam Chok Sing, Marc; Dolabdjian, C.; Wang, Y.(Institute of High Energy Physics, Beijing, 100049, China); P. Finkel; Li, J; Viehland, D.

    2014-01-01

    International audience; The mechanical noise limit of a strain coupled Magneto(elasto)Electric (ME) composite has been investigated when a magnetic or an electric field modulation is applied to sense a low frequency magnetic field and access DC field measurement capabilities. The sensitivity and noise of such a composite sensor was derived from constitutive equations based on the piezoelectric and ferromagnetic material properties. The analysis was used to evaluate the equivalent noise floor ...

  7. Suitability of vaccinia virus and bovine viral diarrhea virus (BVDV for determining activities of three commonly-used alcohol-based hand rubs against enveloped viruses

    Directory of Open Access Journals (Sweden)

    Steinmann Jochen

    2007-02-01

    Full Text Available Abstract Background A procedure for including activity against enveloped viruses in the post-contamination treatment of hands has been recommended, but so far no European standard is available to implement it. In 2004, the German Robert Koch-Institute (RKI and the German Association for the Control of Virus Disease (DVV suggested that vaccinia virus and bovine viral diarrhea virus (BVDV should be used as test viruses in a quantitative suspension test to determine the activity of a disinfectant against all enveloped viruses. Methods We have studied the activities of three commonly-used alcohol-based hand rubs (hand rub A, based on 45% propan-2-ol, 30% propan-1-ol and 0.2% mecetronium etilsulfate; hand rub B, based on 80% ethanol; hand rub C, based on 95% ethanol against vaccinia virus and BVDV, and in addition against four other clinically relevant enveloped viruses: herpes simplex virus (HSV types 1 and 2, and human and avian influenza A virus. The hand rubs were challenged with different organic loads at exposure time of 15, 30 and 60 s. According to the guidelines of both BGA/RKI and DVV, and EN 14476:2005, the reduction of infectivity of each test virus was measured on appropriate cell lines using a quantitative suspension test. Results All three alcohol-based hand rubs reduced the infectivity of vaccinia virus and BVDV by ≥ 4 log10-steps within 15 s, irrespective of the type of organic load. Similar reductions of infectivity were seen against the other four enveloped viruses within 15 s in the presence of different types of organic load. Conclusion Commonly used alcohol-based hand rubs with a total alcohol concentration ≥ 75% can be assumed to be active against clinically relevant enveloped viruses if they effectively reduce the infectivities of vaccinia virus and BVDV in a quantitative suspension test.

  8. Development and evaluation of a replicon particle vaccine expressing the E2 glycoprotein of bovine viral diarrhea virus (BVDV in cattle

    Directory of Open Access Journals (Sweden)

    Loy John Dustin

    2013-01-01

    Full Text Available Abstract Background Bovine viral diarrhea virus is one of the most significant and costly viral pathogens of cattle worldwide. Alphavirus-derived replicon particles have been shown to be safe and highly effective vaccine vectors against a variety of human and veterinary pathogens. Replicon particles are non-propagating, DIVA compatible, and can induce both humoral and cell mediated immune responses. This is the first experiment to demonstrate that Alphavirus-based replicon particles can be utilized in a standard prime/boost vaccination strategy in calves against a commercially significant bovine pathogen. Findings Replicon particles that express bovine viral diarrhea virus sub-genotype 1b E2 glycoprotein were generated and expression was confirmed in vitro using polyclonal and monoclonal antibodies specific to E2. Vaccine made from particles was generated in Vero cells and administered to BVDV free calves in a prime/boost regimen at two dosage levels. Vaccination resulted in neutralizing antibody titers that cross-neutralized both type 1 and type 2 BVD genotypes following booster vaccination. Additionally, high dose vaccine administration demonstrated some protection from clinical disease and significantly reduced the degree of leukopenia caused by viral infection. Conclusions Replicon particle vaccines administered in a prime/boost regimen expressing BVDV E2 glycoprotein can induce cross-neutralizing titers, reduce leukopenia post challenge, and mitigate clinical disease in calves. This strategy holds promise for a safe and effective vaccine to BVDV.

  9. Effect of in-plane magnetic field and applied strain in quantum spin Hall systems: Application to InAs/GaSb quantum wells

    Science.gov (United States)

    Hu, Lun-Hui; Xu, Dong-Hui; Zhang, Fu-Chun; Zhou, Yi

    2016-08-01

    Motivated by the recent discovery of quantized spin Hall effect in InAs/GaSb quantum wells [Du, Knez, Sullivan, and Du, Phys. Rev. Lett. 114, 096802 (2015), 10.1103/PhysRevLett.114.096802], we theoretically study the effects of in-plane magnetic field and strain effect to the quantization of charge conductance by using Landauer-B ütikker formalism. Our theory predicts a robustness of the conductance quantization against the in-plane magnetic field up to a very high field of 20 T. We use a disordered hopping term to model the strain and show that the strain may help the quantization of the conductance. Relevance to the experiments will be discussed.

  10. Caracterização preliminar de amostras do vírus da Diarréia Viral Bovina (BVDV isoladas no Brasil Preliminary characterization of brazilian isolates of bovine viral diarrhea virus (BVDV

    Directory of Open Access Journals (Sweden)

    Sônia A. Botton

    1998-04-01

    Full Text Available O presente artigo relata a caracterização inicial de 19 amostras do vírus da Diarréia Viral Bovina (BVDV isoladas no Brasil, com relação a aspectos biológicos, antigênicos e moleculares. Onze amostras foram isoladas de fetos bovinos, seis foram obtidas do sangue de animais clinicamente saudáveis de rebanhos com problemas reprodutivos e duas amostras foram isoladas de casos clínicos de enfermidade gastrentérica. Os casos de doença entérica afetaram animais jovens e cursaram com diarréia, às vezes sanguinolenta, erosões e ulcerações na mucosa oronasal e do trato digestivo, e eventualmente hemorragias digestivas e petéquias na vulva. Dezesseis amostras (84,2%, incluindo aquelas isoladas de fetos e dos casos clínicos, pertencem ao biotipo não-citopático (ncp. A replicação de outras três amostras (15,8%, foi caracterizada pelo aparecimento de vacuolização e destruição progressiva do tapete celular. A análise das amostras que produziram citopatologia, após clonagem, revelou tratar-se de populações mistas composta de vírus citopáticos (cp e não-citopáticos. A análise de polipeptídeos virais através de SDS-PAGE seguida de "Western-immunoblot" revelou a produção da proteína não-estrutural NS3/p80 em células infectadas com as amostras cp. Em contraste, não se evidenciou a geração da NS3/p80 em células infectadas com as amostras ncp que produziram apenas o polipeptídeo precursor NS23/p125. A subsequente análise de reatividade frente a um painel de 15 anticorpos monoclonais (AcMs revelou uma diversidade antigênica marcante entre os isolados, sobretudo na glicoproteína E2/gp53. Embora um AcM contra essa glicoproteína reagiu com 18 isolados (94,7%, outros nove AcMs anti-E2/gp53 reconheceram entre zero e 57,9% das amostras brasileiras. A grande variabilidade antigênica detectada entre as amostras brasileiras do BVDV pode ter importantes implicações para o diagnóstico e estratégias de controle e imuniza

  11. 牦牛病毒性黏膜病病毒P125基因的克隆及序列分析%Cloning and Bioinformatics Analysis of the P125 Gene of Bovine Viral Diarrhea Virus Strain Yak

    Institute of Scientific and Technical Information of China (English)

    刘亚刚; 孙凯; 王研; 王盼盼; 胡炳峰; 王文伯

    2012-01-01

    According to the sequence data of BVDV strain published by GenBank, five set of primers were designed and used to amplify P125 gene of BVDV strain yak by the method of PCR. A specific 3475 bp DNA segment was amplified, which was cloned into pMD19-T vector. The positive recombinant clone was identified by plasmid PCR and restriction enzyme digestion. Compared with BLAST, the P125 gene of BVDV strain yak exhibited the highest homology with strain NADL, but they only shared 63. 4% , showing that the P125 gene of BVDV strain yak had great variation. This might be the virus to adapt to yak and the ecological environment of the plateau,or the virus might also have an independent source of genetic.%试验参考GenBank中发表的牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)毒株基因组序列设计了5对引物,利用PCR扩增出预期的3475 bp目的片段;将扩增产物连接至pMD19-T载体,经质粒PCR鉴定及双酶切鉴定获得阳性重组质粒并进行核苷酸序列测定.经BLAST同源性分析表明,牦牛BVDV P125基因与BVDV-Ⅰ型的NADL毒株P125基因的同源性为63.4%.系统分析结果表明,牦牛P125基因与BVDV标准毒株P125基因在遗传进化与亲缘关系上均较远,这可能是因为环境诱变的结果或该毒株具有新的遗传衍化来源.

  12. Diversidade antigênica de amostras do vírus da diarréia viral bovina isoladas no Brasil: implicações para o diagnóstico e estratégias de imunização Antigenic diversity of Brazilian isolates of bovine viral diarrhea virus (BVDV): implications for diagnosis and immunization strategies

    OpenAIRE

    Flores, E. F.; R. Weiblen; L.H.V.G. Gil; F.L. Tobias; M. Lima; D.C. Garcez; S.A. Botton

    2000-01-01

    Seqüenciamento e análise filogenética de 17 amostras do vírus da diarréia viral bovina (BVDV) isoladas no Brasil identificaram quatro amostras (23,5%) do genótipo 1a (BVDV-1a), nove amostras (52,9%) do genótipo 1b (BVDV tipo 1b) e quatro amostras (23,5%) do genótipo 2 (BVDV tipo 2). As amostras brasileiras de BVDV tipo 2 apresentaram-se genotipicamente distintas dos BVDV tipo 2 até então identificados na América do Norte e Europa, sugerindo pertencerem a um novo subgenótipo. A caracterização ...

  13. Full genome characterisation of bluetongue virus serotype 6 from the Netherlands 2008 and comparison to other field and vaccine strains.

    Directory of Open Access Journals (Sweden)

    Sushila Maan

    Full Text Available In mid September 2008, clinical signs of bluetongue (particularly coronitis were observed in cows on three different farms in eastern Netherlands (Luttenberg, Heeten, and Barchem, two of which had been vaccinated with an inactivated BTV-8 vaccine (during May-June 2008. Bluetongue virus (BTV infection was also detected on a fourth farm (Oldenzaal in the same area while testing for export. BTV RNA was subsequently identified by real time RT-PCR targeting genome-segment (Seg- 10, in blood samples from each farm. The virus was isolated from the Heeten sample (IAH "dsRNA virus reference collection" [dsRNA-VRC] isolate number NET2008/05 and typed as BTV-6 by RT-PCR targeting Seg-2. Sequencing confirmed the virus type, showing an identical Seg-2 sequence to that of the South African BTV-6 live-vaccine-strain. Although most of the other genome segments also showed very high levels of identity to the BTV-6 vaccine (99.7 to 100%, Seg-10 showed greatest identity (98.4% to the BTV-2 vaccine (RSAvvv2/02, indicating that NET2008/05 had acquired a different Seg-10 by reassortment. Although Seg-7 from NET2008/05 was also most closely related to the BTV-6 vaccine (99.7/100% nt/aa identity, the Seg-7 sequence derived from the blood sample of the same animal (NET2008/06 was identical to that of the Netherlands BTV-8 (NET2006/04 and NET2007/01. This indicates that the blood contained two different Seg-7 sequences, one of which (from the BTV-6 vaccine was selected during virus isolation in cell-culture. The predominance of the BTV-8 Seg-7 in the blood sample suggests that the virus was in the process of reassorting with the northern field strain of BTV-8. Two genome segments of the virus showed significant differences from the BTV-6 vaccine, indicating that they had been acquired by reassortment event with BTV-8, and another unknown parental-strain. However, the route by which BTV-6 and BTV-8 entered northern Europe was not established.

  14. Resposta sorológica e avaliação de proteção fetal em ovelhas prenhes vacinadas contra o vírus da diarréia viral bovina (BVDV

    Directory of Open Access Journals (Sweden)

    Vogel Fernanda Silveira Flores

    2001-01-01

    Full Text Available A resposta sorológica e proteção fetal conferida por três vacinas inativadas contra o vírus da diarréia viral bovina (BVDV (vacinas A, B e C foram avaliadas através de vacinação e posterior desafio de ovelhas prenhes com amostras brasileiras de BVDV-1 e BVDV-2. Níveis baixos a moderados de anticorpos neutralizantes anti-BVDV-1 foram detectados na maioria dos animais (45/47 aos 30 dias após a segunda dose vacinal (títulos médios geométricos [GMT] de 124,7; 74,6 e 26,7 para as vacinas A, B e C, respectivamente. Em contraste, atividade neutralizante anti-BVDV-2 não foi detectada em vários animais (12/47 e foi de magnitude inferior nos três grupos vacinais (GMTs 19,1; 14,1 e 15,1. Os títulos médios de anticorpos reduziram-se significativamente no dia 180, sendo que vários animais já não apresentavam atividade neutralizante detectável frente ao BVDV-1 (grupo B=1/19; C=8/14 e principalmente frente ao BVDV-2 (A=7/14; B=13/19; C=13/14. Nessa data, os títulos médios de anticorpos contra as amostras utilizadas no desafio eram de 91,9; 15,1 e 60,6 (SV-126.8, BVDV-1 e de 10; <10 e 28,3 (SV-260, BVDV-2 nos grupos A, B e C, respectivamente. Nos três grupos vacinais, os níveis de anticorpos neutralizantes contra essas amostras não foram suficientes para prevenir a replicação, disseminação virêmica e transmissão transplacentária dos vírus aos fetos. O vírus foi detectado no sangue e nos fetos de todas as ovelhas vacinadas com as vacinas A (10/10, B (9/9 e C (8/8. Esses resultados demonstram que as vacinas testadas induziram níveis moderados a baixos de anticorpos neutralizantes contra o BVDV-1 e, principalmente contra o BVDV-2 na maioria dos animais; e que esses níveis não foram suficientes para prevenir a infecção fetal frente ao desafio com amostras de BVDV-1 e BVDV-2. Adicionalmente, os resultados confirmam a adequação de ovelhas prenhes para estudos de proteção fetal por vacinas contra o BVDV.

  15. On field acquisition technology of the low strain reflection signal%论低应变反射波信号现场采集技术

    Institute of Scientific and Technical Information of China (English)

    刘新文

    2009-01-01

    Combining with the wide application of the low strain reflection signal in project, the author analyzes the theory of getting pile foun-dation detection based on the low strain reflection signal, aiming at the attention problems of the low strain field acquisiton and combining with project practice gets analysis and conclusion, so as to promote application of the low strain reflection signal method.%结合低应麦反射波法在工程中的广泛应用,分析了低应变反射波法进行桩基检测的原理,针对低应变检测现场采集应注意的问题,结合工程实例进行了分析总结,以推广低应变反射波法的应用.

  16. Mapping strain fields induced in Zr-based bulk metallic glasses during in-situ nanoindentation by X-ray nanodiffraction

    Energy Technology Data Exchange (ETDEWEB)

    Gamcová, J.; Bednarčík, J.; Franz, H. [DESY, Notkestraße 85, Hamburg 22547 (Germany); Mohanty, G.; Wehrs, J.; Michler, J. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstraße 39, Thun 3602 (Switzerland); Michalik, Š. [Institute of Physics ASCR, Na Slovance 2, Praha 18221 (Czech Republic); Krywka, C. [HZG, Institut für Werkstoffforschung, Notkestraße 85, Hamburg 22547 (Germany); Breguet, J. M. [Empa, Swiss Federal Laboratories for Materials Science and Technology, Laboratory for Mechanics of Materials and Nanostructures, Feuerwerkerstraße 39, Thun 3602 (Switzerland); Alemnis GmbH, Feuerwerkerstraße 39, Thun 3602 (Switzerland)

    2016-01-18

    A pioneer in-situ synchrotron X-ray nanodiffraction approach for characterization and visualization of strain fields induced by nanoindentation in amorphous materials is introduced. In-situ nanoindentation experiments were performed in transmission mode using a monochromatic and highly focused sub-micron X-ray beam on 40 μm thick Zr-based bulk metallic glass under two loading conditions. Spatially resolved X-ray diffraction scans in the deformed volume of Zr-based bulk metallic glass covering an area of 40 × 40 μm{sup 2} beneath the pyramidal indenter revealed two-dimensional map of elastic strains. The largest value of compressive elastic strain calculated from diffraction data at 1 N load was −0.65%. The region of high elastic compressive strains (<−0.3%) is located beneath the indenter tip and has radius of 7 μm.

  17. Genetic variation of Border disease virus species strains

    Directory of Open Access Journals (Sweden)

    Massimo Giangaspero

    2011-12-01

    Full Text Available The 5´-untranslated region of Pestivirus strains isolated from domestic and wild animals were analysed to determine their taxonomic status according to nucleotide changes in the secondary genomic structure using the palindromic nucleotide substitutions (PNS method. A total of 131 isolates out of 536 Pestivirus strains evaluated, were clustered as Border disease virus (BDV species. The BDV strains were further divided into at least 8 genotypes or subspecies. Thirty-two isolates from small ruminants suffering from clinical symptoms of Border disease were clustered into bovine viral diarrhoea virus 1 (BVDV-1, BVDV-2 and classical swine fever (hog cholera virus species and also into the tentative BDV-2 species. Since the definition of an infectious disease is based primarily on a specific causative pathogen and taking into account the heterogeneity of the genus Pestivirus, clinical cases should be named according to the laboratory results. The PNS procedure could be useful for laboratory diagnosis of Border disease in domestic and wild ruminants.

  18. Genetic characterization of bovine viral diarrhea virus strains in Beijing, China and innate immune responses of peripheral blood mononuclear cells in persistently infected dairy cattle.

    Science.gov (United States)

    Weng, Xiao Gang; Song, Quan Jiang; Wu, Qiong; Liu, Ming Chao; Wang, Meng Ling; Wang, Jiu Feng

    2015-01-01

    To acquire epidemiological data on the bovine viral diarrhea virus (BVDV) and identify cattle persistently infected (PI) with this virus, 4,327 samples from Holstein dairy cows were screened over a four-year period in Beijing, China. Eighteen BVD viruses were isolated, 12 from PI cattle. Based on genetic analysis of their 5'-untranslated region (5'-UTR), the 18 isolates were assigned to subgenotype BVDV-1m, 1a, 1d, 1q, and 1b. To investigate the innate immune responses in the peripheral-blood mononuclear cells of PI cattle, the expression of Toll-like receptors (TLRs), RIG-I-like receptors, interferon-α (IFN-α), IFN-β, myxovirus (influenza virus) resistance 1 (MX1), and interferon stimulatory gene 15 (ISG15) was assessed by qPCR. When compared with healthy cattle, the expression of TLR-7, IFN-α, and IFN-β mRNA was downregulated, but the expression of MX1 and ISG-15 mRNA was upregulated in PI cattle. Immunoblotting analysis revealed that the expression of interferon regulatory factor 3 (IRF-3) and IRF-7 was lower in PI cattle than in healthy cattle. Thus, BVDV-1m and 1a are the predominant subgenotypes in the Beijing region, and the strains are highly divergent. Our findings also suggest that the TLR-7/IRF-7 signaling pathway plays a role in evasion of host restriction by BVDV.

  19. Biological Control of Pathogens Causing Root Rot Complex in Field Pea Using Clonostachys rosea Strain ACM941.

    Science.gov (United States)

    Xue, Allen G

    2003-03-01

    ABSTRACT Pea root rot complex (PRRC), caused by Alternaria alternata, Aphanomyces euteiches, Fusarium oxysporum f. sp. pisi, F. solani f. sp. pisi, Mycosphaerella pinodes, Pythium spp., Rhizoctonia solani, and Sclerotinia sclerotiorum, is a major yield-limiting factor for field pea production in Canada. A strain of Clonostachys rosea (syn. Gliocladium roseum), ACM941 (ATCC 74447), was identified as a mycoparasite against these pathogens. When grown near the pathogen, ACM941 often was stimulated to produce lateral branches that grew directly toward the pathogen mycelium, typically entwining around the pathogen mycelium. When applied to the seed, ACM941 propagated in the rhizosphere and colonized the seed coat, hypocotyl, and roots as the plant developed and grew. ACM941 significantly reduced the recovery of all fungal pathogens from infected seed, increased in vitro seed germination by 44% and seedling emergence by 22%, and reduced root rot severity by 76%. The effects were similar to those of thiram fungicide, which increased germination and emergence by 33 and 29%, respectively, and reduced root rot severity by 65%. When soil was inoculated with selected PRRC pathogens in a controlled environment, seed treatment with ACM941 significantly increased emergence by 26, 38, 28, 13, and 21% for F. oxysporum f. sp. pisi, F. solani f. sp. pisi, M. pinodes, R. solani, and S. sclerotiorum, respectively. Under field conditions from 1995 to 1997, ACM941 increased emergence by 17, 23, 22, 13, and 18% and yield by 15, 6, 28, 6, and 19% for the five respective pathogens. The seed treatment effects of ACM941 on these PRRC pathogens were greater or statistically equivalent to those achieved with thiram. Results of this study suggest that ACM941 is an effective bioagent in controlling PRRC and is an alternative to existing chemical products. PMID:18944343

  20. Brucella abortus Strain RB51 Vaccine: Immune Response after Calfhood Vaccination and Field Investigation in Italian Cattle Population

    Directory of Open Access Journals (Sweden)

    Manuela Tittarelli

    2008-01-01

    Full Text Available Immune response to Brucella abortus strain RB51 vaccine was measured in cattle vaccinated at calfhood. After an increase at day 6 post-vaccination (pv, the antibody level recorded in the 10 vaccinated animals remained constant for two months, and then progressively decreased. All vaccinated animals remained negative from day 162 pv to the end of the study (day 300 pv. Only at days 13 and 14 pv the RB51-CFT showed 100% sensitivity (credibility interval (CI 76.2%–100%. The results indicate that the possibility to use RB51-CFT for the identification of cattle vaccinated at calfhood with RB51 is limited in time. A field investigation was carried out on 26,975 sera collected on regional basis from the Italian cattle population. The study outcomes indicate that in case of RB51-CFT positive results observed in officially Brucellosis-free (OBF areas and, in any case, when an illegal use of RB51 vaccine is suspected, the use of the RB51-CFT alone is not sufficient to identify all the vaccinated animals. The design of a more sophisticated diagnostic protocol including an epidemiological investigation, the use of RB51-CFT, and the use of the skin test with RB51 as antigen is deemed more appropriate for the identification of RB51 vaccinated animals.

  1. Direct coupled-field numerical simulation of stress and strain of a pipeline subjected to thermally stratified flow

    International Nuclear Information System (INIS)

    This work refers to a numerical analysis to study damages due to thermal fatigue caused by thermal stratification in horizontal pipes. When a pipe is subjected to a thermal stratified flow, non-linear longitudinal and circumferential loads and thermal stripping appear. This phenomenon is present in Nuclear Power Plants (NPP) piping and analysis performed up to the 80's considered only linear loads. Consequently, failure was recorded in many pipes of NPP. In this work, a finite element model simulating the AISI 304L stainless steel pipe, part of the injection nozzle of a NPP steam generator, subjected to thermo-mechanical loading due to thermal stratification effects is presented. The model considered specific geometric characteristics in order to obtain Froude numbers ranging from 0.02 to 0.2, the same range of PWR (Pressurized Water Reactors) NPPs. Coupled thermo-mechanical numerical simulations were performed using ANSYS as finite element platform, with temperatures and pressure inputs taken from results of a conducted thermo-hydraulic experiment. Strain fields obtained will be used as first approximation to design an experiment for thermal fatigue evaluation. (author)

  2. Direct coupled-field numerical simulation of stress and strain of a pipeline subjected to thermally stratified flow

    Energy Technology Data Exchange (ETDEWEB)

    Silva, Luiz Leite da; Rezende, Hugo Cezar; Mansur, Tanius Rodrigues [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mails: silvall@cdtn.br; hcr@cdtn.br; tanius@cdtn.br; Cimini Junior, Carlos Alberto [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil)]. E-mail: cimini@demec.ufmg.br

    2007-07-01

    This work refers to a numerical analysis to study damages due to thermal fatigue caused by thermal stratification in horizontal pipes. When a pipe is subjected to a thermal stratified flow, non-linear longitudinal and circumferential loads and thermal stripping appear. This phenomenon is present in Nuclear Power Plants (NPP) piping and analysis performed up to the 80's considered only linear loads. Consequently, failure was recorded in many pipes of NPP. In this work, a finite element model simulating the AISI 304L stainless steel pipe, part of the injection nozzle of a NPP steam generator, subjected to thermo-mechanical loading due to thermal stratification effects is presented. The model considered specific geometric characteristics in order to obtain Froude numbers ranging from 0.02 to 0.2, the same range of PWR (Pressurized Water Reactors) NPPs. Coupled thermo-mechanical numerical simulations were performed using ANSYS as finite element platform, with temperatures and pressure inputs taken from results of a conducted thermo-hydraulic experiment. Strain fields obtained will be used as first approximation to design an experiment for thermal fatigue evaluation. (author)

  3. Investigation on field method using strain measurement on pipe surface to measure pressure pulsation in piping systems

    International Nuclear Information System (INIS)

    Accurate evaluation of the occurrence location and amplitude of pressure pulsations in piping systems can lead to efficient plant maintenance by preventing fatigue failure of piping and components because the pulsations can be one of the main causes of vibration fatigue and acoustic noise in piping. A non-destructive field method to measure pressure pulsations easily and directly was proposed to replace conventional methods such as prediction using numerical simulations and estimation using locally installed pressure gauges. The proposed method was validated experimentally by measuring pulsating flow in a mock-up piping system. As a result, it was demonstrated that the method to combine strain measurement on the outer surface of pipe with the formula for thick-walled cylinders could measure amplitudes and behavior of the pressure pulsations with a practical accuracy. Factors affecting the measurement accuracy of the proposed method were also discussed. Furthermore, the applicability of the formula for thin-walled cylinders was examined for variously shaped pipes. (author)

  4. Field-oriented trial of the Chinese Brucella suis strain 2 vaccine on sheep and goats in Libya.

    Science.gov (United States)

    Mustafa, A A; Abusowa, M

    1993-01-01

    The Chinese Brucella suis S2 vaccine was studied in a flock of sheep and goats in field conditions. The locally-produced vaccine was orally administered in the form of a drench to 446 ewes, 50 lambs and 20 adult goats. After vaccination, abortion and excretion of the vaccine strain in vaginal discharges or in milk did not occur. Serological tests became positive in 92% of animals at 4 wk post-vaccination and declined to near nil after 1 yr. The protection conferred by the vaccine against a double virulent B melitensis conjunctival challenge which infected 10/10 control ewes was on average 53% in ewes (32/60) and 71% in goats (5/7). Abortion rates were respectively 100% (7/7) in control ewes versus 44% (25/57) and 28% (2/7) in vaccinated ewes and goats. The vaccine was thus found to be safe, antigenic and reasonably protective against the challenge dose used. PMID:8260964

  5. Characterization of Mycoplasma hyosynoviae strains by amplified fragment length polymorphism analysis, pulsed-field gel electrophoresis and 16S ribosomal DNA sequencing

    DEFF Research Database (Denmark)

    Kokotovic, Branko; Friis, N.F.; Ahrens, Peter

    2002-01-01

    , were investigated by analysis of amplified fragment length polymorphisms of the Bgl II and Mfe I restriction sites and by pulsed-field gel electrophoresis of a Bss HII digest of chromosomal DNA. Both methods allowed unambiguous differentiation of the analysed strains and showed similar discriminatory...

  6. Draft Genome Sequence of Methylosinus sp. Strain 3S-1, an Isolate from Rice Root in a Low-Nitrogen Paddy Field.

    Science.gov (United States)

    Bao, Zhihua; Shinoda, Ryo; Minamisawa, Kiwamu

    2016-01-01

    N2-fixing methanotrophs play an important role in the methane-nitrogen cycle in rice paddies. We report here the draft genome sequence of Methylosinus sp. strain 3S-1 isolated from rice root in a paddy field without N fertilizer input. PMID:27587832

  7. Bovine herpesvirus-1: Genetic diversity of field strains from cattle with respiratory disease, genital, fetal disease and systemic neonatal disease and their relationship to vaccine strains.

    Science.gov (United States)

    Fulton, R W; d'Offay, J M; Dubovi, E J; Eberle, R

    2016-09-01

    Bovine herpesvirus-1 (BoHV-1) causes disease in cattle with varied clinical forms. In the U.S. there are two BoHV1 subtypes, BoHV-1.1 and BoHV-1.2b. Control programs in North America incorporate modified live (MLV) or killed (KV) viral vaccines. However, BoHV-1 strains continue to be isolated from diseased animals or fetuses after vaccination. It is possible to differentiate BoHV-1 wild-type from MLV vaccine strains by determining their single nucleotide polymorphism (SNP) patterns through either whole-genome sequencing or PCR sequencing of genomic regions containing vaccine-defining SNPs. To determine the BoHV-1 subtype in clinical isolates and their relationship to MLV strains, 8 isolates from varied clinical disease at three different laboratories in the U.S. were sequenced and phylogenetically analyzed. Five samples were isolated within the past 5 years from New York and 3 were archived samples recovered 35 years prior from Oklahoma and Louisiana. Based on phylogenetic analysis, four of the cases appeared to be due to an MLV vaccine: 3 cases of aborted fetuses and one neonate with systemic BoHV-1 disease. One aborted fetus was from a herd with no reported history of MLV vaccination in two years. The remaining four isolates did not group with any MLV vaccines: two were associated with bovine respiratory disease, one with vulvovaginitis, and a fourth was determined to be a BoHV-1.2b respiratory isolate. Recovery of BoHV-1.1 that is very closely related to an MLV vaccine virus from a herd not receiving vaccines in an extended period prior to its isolation suggests that MLV viruses may remain latent or circulate within herds for long periods. PMID:27374060

  8. Isolation and Characterization of Two Cyanobacterial Strains Calothrix Sp. and Microchaete Sp. from Rice Fields of Karimganj District, Assam, North East India

    Directory of Open Access Journals (Sweden)

    Moirangthem Thajamanbi

    2016-08-01

    Full Text Available Studies on various nitrogen fixing microalgal strains found in the rice paddy field soils are carried out in different parts of the world. In the present study two cyanobacterial strains belonging to the order nostocales, Calothrix sp. and Microchaete sp. were isolated from the rice fields of Karimganj district, South Assam, India and characterized based on their morphological, biochemical and molecular analysis. For the phenotypic characterization - growth, pigments (chlorophyll a, total carotenoid content, phycobiliproteins and biochemical properties (total carbohydrate and soluble proteins were studied. The study showed that both strains contain lower phycoerythrin content as compared to the other pigments. The Microchaete strain contain a higher total carotenoid content while chlorophyll a accumulation was higher in the Calothrix strain. Phylogenetic compairision was made using 16S rRNA gene sequences including other sequences of Calothrix, Microchaete and Tolypothrix species from GenBank. The results showed that polyphasic approach provides necessary information for the identification of cyanobacterial species using morphological analysis in combination with molecular techniques.

  9. Variation in susceptibility of laboratory and field strains of three stored-grain insect species to beta-cyfluthrin and chlorpyrifos-methyl plus deltamethrin applied to concrete surfaces

    Science.gov (United States)

    The efficacy of beta-cyfluthrin and chlorpyrifos-methyl plus deltamethrin applied to clean, concrete floors of empty bins prior to grain storage against field strains of stored-grain insects is unknown. We exposed adults of 16 strains of the red flour beetle, Tribolium castaneum (Herbst); 8 strains ...

  10. Risk assessment, cross-resistance potential, and biochemical mechanism of resistance to emamectin benzoate in a field strain of house fly (Musca domestica Linnaeus).

    Science.gov (United States)

    Khan, Hafiz Azhar Ali; Akram, Waseem; Khan, Tiyyabah; Haider, Muhammad Saleem; Iqbal, Naeem; Zubair, Muhammad

    2016-05-01

    Reduced sensitivity to insecticides in insect pests often results in control failures and increases in the dose and frequency of applications, ultimately polluting the environment. Reduced sensitivity to emamectin benzoate, a broad-spectrum agrochemical belonging to the avermectin group of pesticides, was reported in house flies (Musca domestica L.) collected from Punjab, Pakistan, in 2013. The aim of the present study was to investigate the risk for resistance development, biochemical mechanism, and cross-resistance potential to other insecticides in an emamectin benzoate selected (EB-SEL) strain of house flies. A field-collected strain showing reduced sensitivity to emamectin was re-selected in the laboratory for five consecutive generations and compared with a laboratory susceptible (Lab-Susceptible) reference strain, using bioassays. The field strain showed rapid development of resistance to emamectin (resistance ratio (RR) increased from 35.15 to 149.26-fold) as a result of selection experiments; however, resistance declined when the selection pressure uplifted. The EB-SEL strain showed reduction in resistance to abamectin, indoxacarb, and thiamethoxam. The results of synergism experiments using piperonyl butoxide (PBO) and S,S,S-tributylphosphorotrithioate (DEF) enzyme inhibitors and biochemical analyses revealed that the metabolic resistance mechanism was not responsible in developing emamectin resistance in the EB-SEL strain. In conclusion, the risk for the rapid development of emamectin resistance under continuous selection pressure suggests using a multifaceted integrated pest management approach for house flies. Moreover, the instable nature of emamectin resistance in the EB-SEL strain and lack of cross-resistance to other insecticides provide windows for the rotational use of insecticides with different modes of action. This will ultimately reduce emamectin selection pressure and help improving management programs for house flies without polluting the

  11. Extracting full-field dynamic strain on a wind turbine rotor subjected to arbitrary excitations using 3D point tracking and a modal expansion technique

    Science.gov (United States)

    Baqersad, Javad; Niezrecki, Christopher; Avitabile, Peter

    2015-09-01

    Health monitoring of rotating structures such as wind turbines and helicopter rotors is generally performed using conventional sensors that provide a limited set of data at discrete locations near or on the hub. These sensors usually provide no data on the blades or inside them where failures might occur. Within this paper, an approach was used to extract the full-field dynamic strain on a wind turbine assembly subject to arbitrary loading conditions. A three-bladed wind turbine having 2.3-m long blades was placed in a semi-built-in boundary condition using a hub, a machining chuck, and a steel block. For three different test cases, the turbine was excited using (1) pluck testing, (2) random impacts on blades with three impact hammers, and (3) random excitation by a mechanical shaker. The response of the structure to the excitations was measured using three-dimensional point tracking. A pair of high-speed cameras was used to measure displacement of optical targets on the structure when the blades were vibrating. The measured displacements at discrete locations were expanded and applied to the finite element model of the structure to extract the full-field dynamic strain. The results of the paper show an excellent correlation between the strain predicted using the proposed approach and the strain measured with strain-gages for each of the three loading conditions. The approach used in this paper to predict the strain showed higher accuracy than the digital image correlation technique. The new expansion approach is able to extract dynamic strain all over the entire structure, even inside the structure beyond the line of sight of the measurement system. Because the method is based on a non-contacting measurement approach, it can be readily applied to a variety of structures having different boundary and operating conditions, including rotating blades.

  12. Practical aspects of strain measurement in thin SiGe layers by (004) dark-field electron holography in Lorentz mode.

    Science.gov (United States)

    Denneulin, T; Cooper, D; Rouviere, J L

    2014-07-01

    Dark-field electron holography (DFEH) is a powerful transmission electron microscopy technique for mapping strain with nanometer resolution and high precision. However the technique can be difficult to set up if some practical steps are not respected. In this article, several measurements were performed on thin Si(1-x)Gex layers using (004) DFEH in Lorentz mode. Different practical aspects are discussed such as sample preparation, reconstruction of the holograms and interpretation of the strain maps in terms of sensitivity and accuracy. It was shown that the measurements are not significantly dependent on the preparation tool. Good results can be obtained using both FIB and mechanical polishing. Usually the most important aspect is a precise control of the thickness of the sample. A problem when reconstructing (004) dark-field holograms is the relatively high phase gradient that characterises the strained regions. It can be difficult to perform reconstructions with high sensitivity in both strained and unstrained regions. Here we introduce simple methods to minimise the noise in the different regions using a specific mask shape in Fourier space or by combining several reconstructions. As a test, DFEH was applied to the characterization of eight Si(1-x)Gex samples with different Ge concentrations. The sensitivity of the strain measured in the layers varies between 0.08% and 0.03% for spatial resolutions of 3.5-7 nm. The results were also compared to finite element mechanical simulations. A good accuracy of ±0.1% between experiment and simulation was obtained for strains up to 1.5% and ±0.25% for strains up to 2.5%.

  13. Genome Sequences of Two Pseudomonas syringae pv. tomato Race 1 Strains, Isolated from Tomato Fields in California

    OpenAIRE

    Thapa, Shree P.; Coaker, Gitta

    2016-01-01

    Pseudomonas syringae pv. tomato race 1 strains have evolved to overcome genetic resistance in tomato. Here, we present the draft genome sequences of two race 1 P. syringae pv. tomato strains, A9 and 407, isolated from diseased tomato plants in California.

  14. Establishment and Application of One-step RT-PCR Assay for BVDV Detection%牛病毒性腹泻病毒一步法.RT-PCR检测方法的建立及应用

    Institute of Scientific and Technical Information of China (English)

    于新友; 李天芝; 沈志强

    2015-01-01

    An one-step RT-PCR assay for detection of BVDV was established using a pair of primers based on the 5'-untranslated region gene of bovine viral diarrhea virus (BVDV), and the speciifcity, sensitivity were studied.This method speciifcally amplify a fragment from BVDV, but not from control virus, with a detection limit of 1pg RNA of BVDV.Therefore the established one-step RT-PCR technique provided a sensitive, speciifc, fast and reliablemethod for diagnosis and epizootic study of the BVDV.%根据牛病毒性腹泻病毒(BVDV)5′端非编码区基因保守序列设计引物,建立了检测BVDV一步法反转录-聚合酶链(RT-PCR)方法,并对其特异性、敏感性进行了研究。结果表明,该方法对BVDV检测的灵敏度达到1pg RNA,特异性强、敏感性高,可用于牛病毒性腹泻病的早期确诊和病毒鉴定。

  15. Genetic Structure Change in Harvard Vaccine Strain of Clostridium Tetani for the Period of 1990 to 2010 by Pulsed-Field Gel Electrophoresis

    Directory of Open Access Journals (Sweden)

    Ahmad Sakhravi

    2013-07-01

    Full Text Available Background: PFGE facilitates the differential migration of large DNA fragments through agarose gel by constantly changing the direction of the electrical field during electrophoresis. Possibility of high difference between strains and repeatability make PFGE one of the strong molecular methods in study of bacterial strains in epidemiology. To identifying and DNA fingerprinting of vaccine strain of Clostridium tetani by PFGE technique. Also, possibility of genotyping profile changes in frequency of vaccine strain of C. tetani during the period of 1990 to 2011.Materials and Methods: The vaccine strain of C. tetani was provided by Razi Vaccine and Serum Research Institute in Karaj. The seeds were inoculated into Columbia blood agar and grown for 72 h. The cultures were incubated at 35°C in anaerobic conditions. The PFGE analyses were performed using genomic DNA digested with the restriction enzyme SmaI. The electrophoresis analyses were carried out on a CHEF DR III apparatus (Bio-Rad and band patterns obtained were then analyzed.Results: The PFGE profile obtained from vaccine strain during a period of more than two decades revealed no remarkable genetic changes and mutations. This type of analysis provides detailed data useful for surveillance of vaccine strains and isolates as well as for the selection of certain predominant profiles for further investigation.Conclusion: This study showed no considerable change in chromosomal genome of Harvard, the vaccine strain. It is therefore concluded that the vaccine produced by Razi Institute had evidently no alteration or modification in accordance to PFGE profile analysis during a period of more than two decades.

  16. Enhanced carrier mobility and direct tunneling probability of biaxially strained Ge{sub 1−x}Sn{sub x} alloys for field-effect transistors applications

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Lei; Liang, Renrong, E-mail: liangrr@tsinghua.edu.cn, E-mail: junxu@tsinghua.edu.cn; Wang, Jing; Xu, Jun, E-mail: liangrr@tsinghua.edu.cn, E-mail: junxu@tsinghua.edu.cn [Tsinghua National Laboratory for Information Science and Technology, Institute of Microelectronics, Tsinghua University, Beijing 100084 (China)

    2015-05-14

    The carrier transport and tunneling capabilities of biaxially strained Ge{sub 1−x}Sn{sub x} alloys with (001), (110), and (111) orientations were comprehensively investigated and compared. The electron band structures of biaxially strained Ge{sub 1−x}Sn{sub x} alloys were calculated by the nonlocal empirical pseudopotential method and the modified virtual crystal approximation was adopted in the calculation. The electron and hole effective masses at the band edges were extracted using a parabolic line fit. It is shown that the applied biaxial strain and the high Sn composition are both helpful for the reduction of carrier effective masses, which leads to the enhanced carrier mobility and the boosted direct band-to-band-tunneling probability. Furthermore, the strain induced valance band splitting reduces the hole interband scattering, and the splitting also results in the significantly enhanced direct tunneling rate along the out-of-plane direction compared with that along the in-plane direction. The biaxially strained (111) Ge{sub 1−x}Sn{sub x} alloys exhibit the smallest band gaps compared with (001) and (110) orientations, leading to the highest in-plane and out-of-plane direct tunneling probabilities. The small effective masses on (110) and (111) planes in some strained conditions also contribute to the enhanced carrier mobility and tunneling probability. Therefore, the biaxially strained (110) and (111) Ge{sub 1−x}Sn{sub x} alloys have the potential to outperform the corresponding (001) Ge{sub 1−x}Sn{sub x} devices. It is important to optimize the applied biaxial strain, the Sn composition, and the substrate orientation for the design of high performance Ge{sub 1−x}Sn{sub x} field-effect transistors.

  17. A Study of Piezoelectric Field Related Strain Difference in GaN-Based Blue Light-Emitting Diodes Grown on Silicon(111) and Sapphire Substrates.

    Science.gov (United States)

    Jeon, K S; Sung, J H; Lee, M W; Song, H Y; Shin, H Y; Park, W H; Jang, Y I; Kang, M G; Choi, Y H; Lee, J S; Ko, D H; Ryu, H Y

    2016-02-01

    We investigate the strain difference in InGaN/GaN multiple quantum wells of blue light-emitting diode (LED) structures grown on silicon(1 11) and c-plane sapphire substrates by comparing the strength of piezo-electric fields in MQWs. The piezo-electric fields for two LED samples grown on silicon and sapphire substrates are measured by using the reverse-bias electro-reflectance (ER) spectroscopy. The flat-band voltage is obtained by measuring the applied reverse bias voltage that induces a phase inversion in the ER spectra, which is used to calculate the strength of piezo-electric fields. The piezo-electric field is determined to be 1.36 MV/cm for the LED on silicon substrate and 1.83 MV/cm for the LED on sapphire substrate. The ER measurement results indicate that the strain-induced piezo-electric field is greatly reduced in the LED grown on silicon substrates consistent with previous strain measurement results by micro-Raman spectroscopy and high-resolution transmission electron microscopy. PMID:27433673

  18. THz Radiation from Intracavity Saturable Bragg Reflector in Magnetic Field with Self-Started Mode-Locking by Strained Saturable Bragg Reflector

    Science.gov (United States)

    Liu, Tze-An; Huang, Kai-Fung; Pan, Ci-Ling; Liu, Zhenlin; Ono, Shingo; Ohtake, Hideyuki; Sarukura, Nobuhiko

    1999-11-01

    We demonstrate a new configuration for intracavity generation of THz radiation. A magnetic-field-biased saturable Bragg reflector (SBR) located inside the femtosecond laser cavity is the emitter, while a strained saturable Bragg reflector (SSBR) achieves self-started mode-locking without focusing. The calibrated power of the emitted THz radiation is estimated to be approximately 45 nW with a peak frequency at 0.72 THz and width of approximately 0.7 THz under a 0.88 T magnetic field. The quadratic dependence of THz-radiation power by the SBR on the magnetic field is also observed for the first time.

  19. Impact of oral meloxicam and long-distance transport on cell-mediated and humoral immune responses in feedlot steers receiving modified live BVDV booster vaccination on arrival.

    Science.gov (United States)

    Van Engen, N K; Platt, R; Roth, J A; Stock, M L; Engelken, T; Vann, R C; Wulf, L W; Busby, W D; Wang, C; Kalkwarf, E M; Coetzee, J F

    2016-07-01

    The objective of this study was to investigate the impact of oral meloxicam (MEL) and long-distance transportation on cell-mediated immunity (CMI) in preconditioned steers receiving a booster vaccination on arrival. We hypothesized that steers treated with MEL at 1mg/kg body weight, 6h before night-time transport, would be less immunocompromised on arrival (day 0) and after 7days, and that CMI following vaccination with a modified live bovine viral diarrhea virus (BVDV) recall antigen would be increased. Brahman crossbreed steers, 13-17 months of age (n=87), were randomly assigned to one of four treatment groups: MEL, transported (MTR) (n=22), MEL, non-transported (MNT) (n=22), lactose placebo, transported (CTR) (n=21), and lactose placebo, non-transported (CNT) (n=22). MTR and CTR steers were transported for approximately 16h non-stop on a truck from Mississippi to Iowa (approximately 1300km), whereas steers in the MNT and CNT groups remained in Mississippi as non-transported controls. Body weight was measured and jugular blood was collected at -1, 0, and 7days from all steers at the same time, regardless of location. Multi-parameter flow cytometry (MP-FCM) was used to identify T-cell subsets and detect the expression of three activation markers (CD25 [interleukin (IL)-2 receptor], intracellular interferon-gamma [IFNγ], and IL-4) after in vitro stimulation with BVDV recall antigen. Plasma cortisol concentration was measured on day -1, 0, and 7 as a marker of transport-associated stress. Serum antibody titer to BVDV was assessed on day -1 and day 7 post-booster vaccination. Whole-blood samples were analyzed using MP-FCM on days 0 and 7. Results were log transformed and analyzed using repeated measures of analysis of variance. Compared with non-transported controls, transport led to an increase in BVDV-induced expression of CD25, IFNγ, and IL-4 in CD4(+), CD8(+), and γδ(+) T-cell subsets (P0.10). A treatment*transport interaction was noted for the increase in IL

  20. A combined in silico/in vitro approach unveils common molecular requirements for efficient BVDV RdRp binding of linear aromatic N-polycyclic systems.

    Science.gov (United States)

    Carta, A; Briguglio, I; Piras, S; Corona, P; Ibba, R; Laurini, E; Fermeglia, M; Pricl, S; Desideri, N; Atzori, E M; La Colla, P; Collu, G; Delogu, I; Loddo, R

    2016-07-19

    In this work, we present and discuss a comprehensive set of both newly and previously synthesized compounds belonging to 5 distinct molecular classes of linear aromatic N-polycyclic systems that efficiently inhibits bovine viral diarrhea virus (BVDV) infection. A coupled in silico/in vitro investigation was employed to formulate a molecular rationale explaining the notable affinity of all molecules to BVDV RNA dependent RNA polymerase (RdRp) NS5B. We initially developed a three-dimensional common-feature pharmacophore model according to which two hydrogen bond acceptors and one hydrophobic aromatic feature are shared by all molecular series in binding the viral polymerase. The pharmacophoric information was used to retrieve a putative binding site on the surface of the BVDV RdRp and to guide compound docking within the protein binding site. The affinity of all compounds towards the enzyme was scored via molecular dynamics-based simulations, showing high correlation with in vitro EC50 data. The determination of the interaction spectra of the protein residues involved in inhibitor binding highlighted amino acids R295 and Y674 as the two fundamental H-bond donors, while two hydrophobic cavities HC1 (residues A221, I261, I287, and Y289) and HC2 (residues V216, Y303, V306, K307, P408, and A412) fulfill the third pharmacophoric requirement. Three RdRp (K263, R295 and Y674) residues critical for drug binding were selected and mutagenized, both in silico and in vitro, into alanine, and the affinity of a set of selected compounds towards the mutant RdRp isoforms was determined accordingly. The agreement between predicted and experimental data confirmed the proposed common molecular rationale shared by molecules characterized by different chemical scaffolds in binding to the BVDV RdRp, ultimately yielding compound 6b (EC50 = 0.3 μM; IC50 = 0.48 μM) as a new, potent inhibitor of this Pestivirus. PMID:27161176

  1. Integrated control of an acaricide-resistant strain of the cattle tick Rhipicephalus microplus by applying Metarhizium anisopliae associated with cypermethrin and chlorpyriphos under field conditions.

    Science.gov (United States)

    Webster, Anelise; Reck, José; Santi, Lucélia; Souza, Ugo A; Dall'Agnol, Bruno; Klafke, Guilherme M; Beys-da-Silva, Walter O; Martins, João Ricardo; Schrank, Augusto

    2015-01-30

    The efficacy of the fungus Metarhizium anisopliae to control ticks has been shown in several in vitro experiments. However, few studies have been undertaken in field conditions in order to demonstrate the applicability of its use as a biological control of ticks and its combination with chemical acaricides. The aim of the present study was to evaluate the efficacy of M. anisopliae to control an acaricide-resistant strain of Rhipicephalus microplus under laboratory and field conditions. First, the compatibility of M. anisopliae strain (TIS-BR03) with commercial acaricides and its potential to control the cattle tick were evaluated in vitro. In general, acaricide treatments had mild effects on fungus viability. In the field experiment, the median of treatment efficacy with acaricide only, M. anisopliae only and combination of M. anisopliae with acaricide were 71.1%, 56.3% and 97.9%, respectively. There is no statistical difference between groups treated with M. anisopliae and acaricide alone. Thus, in this work we have demonstrated the applicability of M. anisopliae use associated or not with chemical acaricides on field conditions in order to control an acaricide-resistant strain of the cattle tick R. microplus. PMID:25577676

  2. Full-field mapping of internal strain distribution in red sandstone specimen under compression using digital volumetric speckle photography and X-ray computed tomography

    Directory of Open Access Journals (Sweden)

    Lingtao Mao

    2015-04-01

    Full Text Available It is always desirable to know the interior deformation pattern when a rock is subjected to mechanical load. Few experimental techniques exist that can represent full-field three-dimensional (3D strain distribution inside a rock specimen. And yet it is crucial that this information is available for fully understanding the failure mechanism of rocks or other geomaterials. In this study, by using the newly developed digital volumetric speckle photography (DVSP technique in conjunction with X-ray computed tomography (CT and taking advantage of natural 3D speckles formed inside the rock due to material impurities and voids, we can probe the interior of a rock to map its deformation pattern under load and shed light on its failure mechanism. We apply this technique to the analysis of a red sandstone specimen under increasing uniaxial compressive load applied incrementally. The full-field 3D displacement fields are obtained in the specimen as a function of the load, from which both the volumetric and the deviatoric strain fields are calculated. Strain localization zones which lead to the eventual failure of the rock are identified. The results indicate that both shear and tension are contributing factors to the failure mechanism.

  3. A model for the prediction of Nb sub 3 Sn critical current as a function of field, temperature, strain, and radiation damage

    Energy Technology Data Exchange (ETDEWEB)

    Summers, L.T.; Guinan, M.W.; Miller, J.R.; Hahn, P.A.

    1990-09-21

    Conductors designed for fusion machines must operate at high fields, under large mechanical loads, and in a high neutron flux. Present designs favor the use of Nb{sub 3}Sn with force-cooling by supercritical helium to extract large nuclear and ac loss heat loads. Consequently, the magnet designer must have a good knowledge of the critical current of the superconductor as a function of field, strain, temperature, and radiation damage. Expanding on work by Hampshire, et al. and Ekin, combined with radiation damage studies of Nb{sub 3}Sn, we express the critical field (B{sub c20}) as function of temperature, strain and damage energy (E{sub d}). Similarly, the zero-field critical temperature (T{sub c0}) is expressed as a function of strain and damage energy. The expressions of B{sub c20} and T{sub c0} are combined into a functional form that allows an accurate and consistent estimate of the critical current density at the operating conditions of fusion magnet conductors. 9 refs., 4 figs.

  4. A theory of the strain-dependent critical field in Nb3Sn, based on anharmonic phonon generation

    CERN Document Server

    Valentinis, D F; Bordini, B; Rossi, L

    2014-01-01

    We propose a theory to explain the strain dependence of the critical properties in A15 superconductors. Starting from the strong-coupling formula for the critical temperature, and assuming that the strain sensitivity stems mostly from the electron-phonon alpha F-2 function, we link the strain dependence of the critical properties to a widening of alpha F-2. This widening is attributed to the nonlinear generation of phonons, which takes place in the anharmonic deformation potential induced by the strain. Based on the theory of sum- and difference-frequency wave generation in nonlinear media, we obtain an explicit connection between the widening of alpha F-2 and the anharmonic energy. The resulting model is fit to experimental datasets for Nb3Sn, and the anharmonic energy extracted from the fits is compared with first-principles calculations.

  5. Whole genome characterisation and engineering of chimaeric rotavirus-like particles using African rotavirus field strains / Khuzwayo Chidiwa Jere

    OpenAIRE

    Jere, Khuzwayo Chidiwa

    2012-01-01

    Despite the global licensure of two live-attenuated rotavirus vaccines, Rotarix® and RotaTeq®, rotavirus remains the major cause of severe dehydrating diarrhoea in young mammals and the need for further development of additional rotavirus vaccines, especially vaccines effective against regional strains in developing country settings, is increasing. The design and formulation of new effective multivalent rotavirus vaccines is complicated by the wide rotavirus strain diversity. N...

  6. Population Genetic Structure of Listeria monocytogenes Strains as Determined by Pulsed-Field Gel Electrophoresis and Multilocus Sequence Typing

    DEFF Research Database (Denmark)

    Henri, Clémentine; Félix, Benjamin; Guillier, Laurent;

    2016-01-01

    Listeria monocytogenes is a ubiquitous bacterium that may cause the foodborne illness listeriosis. Only a small amount of data about the population genetic structure of strains isolated from food is available. This study aimed to provide an accurate view of the L. monocytogenes food strain popula......, meat products, and dairy products. We opened the way to source attribution modeling in order to quantify the relative importance of the main food matrices.......Listeria monocytogenes is a ubiquitous bacterium that may cause the foodborne illness listeriosis. Only a small amount of data about the population genetic structure of strains isolated from food is available. This study aimed to provide an accurate view of the L. monocytogenes food strain...... population in France. From 1999 to 2014, 1,894 L. monocytogenes strains were isolated from food at the French National Reference Laboratory for L. monocytogenes and classified according to the five risk food matrices defined by the European Food Safety Authority (EFSA). A total of 396 strains were selected...

  7. Martensitic transformation and magnetic-field-induced strain in magnetic shape memory alloy NiMnGa melt-spun ribbon

    Energy Technology Data Exchange (ETDEWEB)

    Guo Shihai; Zhang Yanghuan; Quan Baiyun; Li Jianliang; Wang Xinlin [Dept. of Functional Material Research, Central Iron and Steel Research Inst., Beijing, BJ (China)

    2005-07-01

    A non-stoichiometric polycrystalline Ni{sub 50}Mn{sub 27}Ga{sub 23} magnetic shape memory alloy was prepared by melt-spinning technology. The effects of melt-spinning on the martensitic transformation and magnetic-field-induced strain (MFIS) of the melt-spun ribbon were investigated. The experimental results show that the melt-spun ribbon undergoes the thermal-elastic martensitic transformation and exhibits the thermo-elastic shape memory effect. But the martensitic transformation temperature decreases and Curie temperature remains unchanged. A particular internal stress induced by melt-spinning made a texture structure in the melt-spun ribbon, which made the melt-spun ribbon obtain larger transition-induced strain and MFIS. The internal stress was released under cycling of magnetic field. This resulted in a decrease of MFIS of the melt-spun ribbon. (orig.)

  8. Brucella abortus 1119-3 O-chain polysaccharide to differentiate sera from B. abortus S-19-vaccinated and field-strain-infected cattle by agar gel immunodiffusion.

    OpenAIRE

    Cherwonogrodzky, J W; Nielsen, K H

    1988-01-01

    Purified Brucella abortus 1119-3 and Brucella melitensis 16M lipopolysaccharide O-chain polysaccharides were not precipitated in agar gel immunodiffusion by any of 24 sera from vaccinated cattle but were precipitated by 18 of 24 sera from infected cattle. This difference can be used to differentiate sera of cattle vaccinated with B. abortus S-19 from sera of some field-strain-infected cattle.

  9. Effects of ambient temperature and early open-field response on the behaviour, feed intake and growth of fast- and slow-growing broiler strains

    DEFF Research Database (Denmark)

    Nielsen, Birte Lindstrøm

    2012-01-01

    in an open-field test on day 3 after hatching, fast-growing Ross 208 and slow-growing i657 chickens were allocated on day 13 to one of the 48 groups. Each group included either six active or six passive birds from each strain and the groups were housed in floor-pens littered with wood chips and fitted......Increased activity improves broiler leg health, but also increases the heat production of the bird. This experiment investigated the effects of early open-field activity and ambient temperature on the growth and feed intake of two strains of broiler chickens. On the basis of the level of activity...... with two heat lamps. Each group was fed ad libitum and subjected to one of the three temperature treatments: two (HH; 268C), one (HC; 168C to 268C) or no (CC; 168C) heat lamps turned on. Production and behavioural data were collected every 2 weeks until day 57. For both strains, early open-field activity...

  10. Retrospective epidemiological evaluation of molecular and animal husbandry data within the bovine viral diarrhoea virus (BVDV) control programme in Western Austria during 2009-2014.

    Science.gov (United States)

    Schoepf, Karl; Revilla-Fernández, Sandra; Steinrigl, Adolf; Fuchs, Reinhard; Sailer, Andreas; Weikel, Joachim; Schmoll, Friedrich

    2016-01-01

    A retrospective epidemiological investigation of molecular and animal husbandry data collected over an observation period of five years (2009-2014) within the compulsory bovine viral diarrhoea virus (BVDV) control programme in Western Austria, covering the federal provinces of Tyrol and Vorarlberg is presented in this study. Samples collected from 232 infected calves were phylogenetically classified based on the 5' untranslated region (5'UTR). All but 13 samples, which were typed as border disease virus subtype 3 (BDV-3), belonged to the bovine viral diarrhoea virus genotype 1 (BVDV-1) and clustered within six different subtypes (1b, 1e, 1f, 1h, 1d and 1k). Movement data and survival times from infected individual animals were analysed because of their potential of passing on infection to naive herds. From the moment of submission of the laboratory results, 180 animals were culled within the first month, 13 lived longer than two but not longer than six months and seven infected animals lived longer than one year. 13 of the infected animals were born on alpine pastures and eleven infected animals were grazed on mountain pastures during summer. The movement of infected animals and the role of trade in alpine areas are a possible source for spreading the infection, thus hampering the progress of eradication.

  11. THE CURRENT PREVALENCE STATUS OF BVDV IN CHINA%牛病毒性腹泻在中国的流行现状分析

    Institute of Scientific and Technical Information of China (English)

    朱礼倩; 周艳君; 于海; 童光志

    2011-01-01

    牛病毒性腹泻是由牛病毒性腹泻病毒(Bovine viral diarrhea virus,BVDV)引起的,主要侵害牛、羊、鹿、牦牛等反刍动物及猪的一种重要传染病。该病对畜牧业危害巨大,欧美等国家已经开始实施BVDV根除计划。该病在中国广泛流行,本文就BVDV在中国的流行状况进行分析和概述。%Bovine viral diarrhea virus(BVDV) imposes severe threat to cattle,sheep and other ruminants and swine.The disease has caused significant economical loss to cattle farms worldwide.The eradication program for BVDV has being carried out in Europe.Bovine viral diarrhea virus is widely distributed in China.The prevalence of BVDV in China was updated in the review.

  12. The role of herpesviruses (BoHV-1 and BoHV-4) and pestiviruses (BVDV and BDV) in ruminant abortion cases in western Turkey.

    Science.gov (United States)

    Tuncer-Göktuna, Pelin; Alpay, Gizem; Öner, Eda Baldan; Yeşilbağ, Kadir

    2016-06-01

    The economic impact of abortions in ruminant breeders is one of the biggest problems in livestock. Of the infectious agents, viruses, especially herpesviruses and pestiviruses, are the most important causative agents of abortion in ruminants. In the present study, the role of herpesviruses (bovine herpesvirus-1 (BoHV-1), bovine herpesvirus-4 (BoHV-4)) and pestiviruses (bovine viral diarrhea virus (BVDV), border disease virus (BDV)) was investigated in cases of ruminant abortion between 2007 and 2015 in western Turkey. Out of 81 aborted fetal samples (60 calves, 19 lambs, and 2 kids), 42 were positive, which included 31 calves, 9 lambs, and 2 goats; 39 aborted fetal samples were negative for the pestivirus antigen ELISA. BoHV-1 antigen ELISA was positive in 3 cases which included 2 calves and 1 lamb; the remainder 78 cases were negative. Pestivirus and BoHV-1 were positive in 51.85 and 3.70 %, respectively, of the samples. According to PCR analysis, BoHV-4 was not encountered in any of the tested samples. In one of the calf fetus samples, both BVDV and BoHV-1 were positive; in one of the lamb fetus samples, BoHV-1 was positive. There was a much higher level of pestivirus antigen than the other viral agents evaluated in the study (p viral cause of ruminant abortions in the examined area. PMID:27038195

  13. A non-contacting approach for full field dynamic strain monitoring of rotating structures using the photogrammetry, finite element, and modal expansion techniques

    Science.gov (United States)

    Baqersad, Javad

    Health monitoring of rotating structures such as wind turbines and helicopter rotors is generally performed using conventional sensors that provide a limited set of data at discrete locations near or on the hub. These sensors usually provide no data on the blades or interior locations where failures may occur. Within this work, an unique expansion algorithm was extended and combined with finite element (FE) modeling and an optical measurement technique to identify the dynamic strain in rotating structures. The merit of the approach is shown by using the approach to predict the dynamic strain on a small non-rotating and rotating wind turbine. A three-bladed wind turbine having 2.3-meter long blades was placed in a semi-built-in boundary condition using a hub, a machining chuck, and a steel block. A finite element model of the three wind turbine blades assembled to the hub was created and used to extract resonant frequencies and mode shapes. The FE model was validated and updated using experimental modal tests. For the non-rotating optical test, the turbine was excited using a sinusoidal excitation, a pluck test, arbitrary impacts on three blades, and random force excitations with a mechanical shaker. The response of the structure to the excitations was measured using three-dimensional point tracking. A pair of high-speed cameras was used to measure the displacement of optical targets on the structure when the blades were vibrating. The measured displacements at discrete locations were expanded and applied to the finite element model of the structure to extract the full-field dynamic strain. The results of the work show an excellent correlation between the strain predicted using the proposed approach and the strain measured with strain-gages for all of the three loading conditions. Similar to the non-rotating case, optical measurements were also preformed on a rotating wind turbine. The point tracking technique measured both rigid body displacement and flexible

  14. Rapid real-time PCR methods to distinguish Salmonella Enteritidis wildtype field isolates from vaccine strains Salmovac SE/Gallivac SE and AviPro SALMONELLA VAC E.

    Science.gov (United States)

    Maurischat, Sven; Szabo, Istvan; Baumann, Beatrice; Malorny, Burkhard

    2015-05-01

    Salmonella enterica serovar Enteritidis is a major non-typhoid Salmonella serovar causing human salmonellosis mainly associated with the consumption of poultry and products thereof. To reduce infections in poultry, S. Enteritidis live vaccine strains AviPro SALMONELLA VAC E and Salmovac SE/Gallivac SE have been licensed and used in several countries worldwide. To definitively diagnose a S. Enteritidis contamination in vaccinated herds a reliable and fast method for the differentiation between vaccine and wildtype field isolates is required. In this study, we developed and validated real-time PCR (qPCR) assays to distinguish those variants genetically. Suitable target sequences were identified by whole genome sequencing (WGS) using the Illumina MiSeq system. SNP regions in kdpA and nhaA proved to be most useful for differentiation of AviPro SALMONELLA VAC E and Salmovac SE/Gallivac SE, respectively, from wildtype strains. For each vaccine strain one TaqMan-qPCR assay and one alternative approach using High Resolution Melting (HRM) analysis was designed. All 30 Salmovac SE and 7 AviPro SALMONELLA VAC E vaccine strain reisolates tested were correctly identified by both approaches (100% inclusivity). Furthermore, all 137 (TaqMan) and 97 (HRM) Salmonella non-vaccine and related Enterobacteriaceae strains tested were excluded (100% exclusivity). The analytical detection limits were determined to be approx. 10(2) genome copies/reaction for the TaqMan and 10(4) genome copies/reaction for the HRM approach. The real-time PCR assays proved to be a reliable and fast alternative to the cultural vaccine strain identification tests helping decision makers in control measurements to take action within a shorter period of time. PMID:25794902

  15. Association of Job Strain With Cortisol and Alpha-Amylase Among Shift-Working Health Care Professionals in Laboratory and Field.

    Science.gov (United States)

    Karhula, Kati; Härmä, Mikko; Sallinen, Mikael; Lindholm, Harri; Hirvonen, Ari; Elovainio, Marko; Kivimäki, Mika; Vahtera, Jussi; Puttonen, Sampsa

    2016-01-01

    Although the prevalence of work-related stress has increased, knowledge on the contributions of that stress to long-term adverse health effects is still lacking. Stress biomarkers can reveal early signs of negative health effects, but no previous studies have measured both acute stress reactions and long-term exposure to job strain using both salivary cortisol and α-amylase (AA). The present study examines the association between job strain and these biomarkers among shift-working female health care professionals in the laboratory and the field. The 95 participants were recruited from hospital wards categorized in either the top (high job strain [HJS] group, n = 42) or the bottom quartile of job strain (low job strain [LJS] group, n = 53), as rated by survey responses. Participants' self-perceived job strain was at least as high or low as the ward's average estimation. Saliva samples were collected during the Trier Social Stress Test (TSST), preselected morning and night shifts, and a day off. There was a larger increase in the cortisol concentration of participants in the HJS than in the LJS group (2.27- vs. 1.48-fold, respectively, nonsignificant) during the TSST. Participants in the HJS group also had higher salivary AA levels 30 min after awakening on the morning-shift day than those in the LJS group (p = .02), whereas the salivary cortisol awakening response on the day off was higher in the LJS group (p = .05, education as a covariate). The remaining stress-biomarker results did not differ significantly between groups. These data suggest that HJS in shift-working health care professionals is weakly associated with changes in stress biomarkers. PMID:25827426

  16. Strain-mediated electric-field control of exchange bias in a Co90Fe10/BiFeO3/SrRuO3/PMN-PT heterostructure

    Science.gov (United States)

    Wu, S. Z.; Miao, J.; Xu, X. G.; Yan, W.; Reeve, R.; Zhang, X. H.; Jiang, Y.

    2015-03-01

    The electric-field (E-field) controlled exchange bias (EB) in a Co90Fe10/BiFeO3 (BFO)/SrRuO3/PMN-PT heterostructure has been investigated under different tensile strain states. The in-plane tensile strain of the BFO film is changed from +0.52% to +0.43% as a result of external E-field applied to the PMN-PT substrate. An obvious change of EB by the control of non-volatile strain has been observed. A magnetization reversal driven by E-field has been observed in the absence of magnetic field. Our results indicate that a reversible non-volatile E-field control of a ferromagnetic layer through strain modulated multiferroic BFO could be achieved at room temperature.

  17. Relaxation of the three dimensional strain field near a notch in Zr-2.5nb ct specimen

    International Nuclear Information System (INIS)

    The time-dependent, elastic lattice strain distribution ahead of a blunt notch in a curved, compact toughness (CT) specimen has been examined analytically and compared to experimental results. The CT specimen was manufactured from Zr-2.5Nb pressure tube material that is used for the manufacturing of pressure tubes in CANDU power generating stations. The thermally-induced creep strain distribution in the specimen was determined experimentally using neutron diffraction techniques. A three dimensional (3-D) finite element analysis of the compact toughness specimen is performed using as material subroutine, a self-consistent polycrystalline model that takes into account the anisotropic plastic and creep response of the Zr-2.5Nb material. This material model allows for the quantitative determination of the strain and stress distribution that evolve during the loading of the specimen. The stresses from the 3-D finite element calculation were then processed through the elasto-plastic polycrystalline code to extract the lattice strains in a given specimen direction. It was found that the lattice strains in the plane of the notch calculated at various time intervals compare very well with the distribution and magnitude of the experimentally determined measurements obtained at the same time intervals by means of neutron diffraction. The experimental results have shown that localised stress relaxation does occur near a notch region and that the model does capture this phenomenon. This indicates that in-service pressure tubes will have a higher tolerance to surface defects as a result of stress relaxation occurring due to creep

  18. Técnica rápida de neutralização viral para a detecção de anticorpos contra o vírus da Diarréia Viral Bovina (BVDV no leite A rapid virus-neutralization test for detection of antibodies against bovine viral diarrhea virus (BVDV in milk

    Directory of Open Access Journals (Sweden)

    Scherer Charles Fernando Capinos

    2002-04-01

    Full Text Available A identificação de rebanhos positivos para o vírus da Diarréia Viral Bovina (BVDV através de detecção de anticorpos no leite pode viabilizar programas de controle em larga escala. Com esse objetivo, a técnica de soro-neutralização (SN foi adaptada para a pesquisa de anticorpos em amostras de leite. A adaptação consistiu na redução do tempo de incubação do teste, seguida da detecção de antígenos virais por imunofluorescência. A redução do tempo de incubação minimizou os efeitos tóxicos do leite sobre as células de cultivo, além de permitir a obtenção dos resultados em 24 horas. A técnica rápida (SNR foi inicialmente testada em 1.335 amostras de soro bovino, apresentando sensibilidade de 93,7% e concordância de 91,1% em relação à SN tradicional. A SNR foi também utilizada para testar 423 amostras de soro bovino que apresentaram toxicidade para as células na SN tradicional, detectando 316 (74,7% amostras positivas. O teste de amostras de soro e leite de 520 vacas em lactação demonstrou que a SNR pode detectar anticorpos no leite de vacas com títulos séricos a partir de 10. Atividade neutralizante anti-BVDV no leite foi detectada em 97,4% (191/196 de vacas com títulos séricos ³ 320; em 92,9% (79/85 de vacas com títulos de 160; em 88% (59/67 de vacas títulos de 80. A freqüência de animais positivos na SNR foi de 76,9% (40/52 para animais com títulos séricos de 40; 61,3% (19/31 com títulos de 20 e de 33,3% (10/30 para vacas com títulos de 10. Esses resultados demonstram que a técnica de SNR é adequada para a pesquisa de anticorpos anti-BVDV no leite, principalmente em animais com títulos moderados e altos de anticorpos. Essa técnica pode ser utilizada para testar amostras coletivas de leite e identificar rebanhos com atividade viral. A utilização dessa técnica pode viabilizar programas regionais de combate à infecção, pois permite testar um grande número de amostras e identificar rebanhos

  19. Influence of Schottky drain contacts on the strained AlGaN barrier layer of AlGaN/AlN/GaN heterostructure field-effect transistors

    Institute of Scientific and Technical Information of China (English)

    Cao Zhi-Fang; Lin Zhao-Jun; Li Yuan-Jie; Luan Chong-Biao; Wang Zhan-Guo

    2013-01-01

    Rectangular Schottky drain A1GaN/AlN/GaN heterostructure field-effect transistors (HFETs) with different gate contact areas and conventional A1GaN/A1N/GaN HFETs as control were both fabricated with same size.It was found there is a significant difference between Schottky drain A1GaN/A1N/GaN HFETs and the control group both in drain series resistance and in two-dimensional electron gas (2DEG) electron mobility in the gate--drain channel.We attribute this to the different influence of Ohmic drain contacts and Schottky drain contacts on the strained A1GaN barrier layer.For conventional AlGaN/AlN/GaN HFETs,annealing drain Ohmic contacts gives rise to a strain variation in the A1GaN barrier layer between the gate contacts and the drain contacts,and results in strong polarization Coulomb field scattering in this region.In Schottky drain A1GaN/A1N/GaN HFETs,the strain in the A1GaN barrier layer is distributed more regularly.

  20. Strained Silicon Photonics

    OpenAIRE

    Wehrspohn, Ralf B; Jörg Schilling; Christian Bohley; Clemens Schriever

    2012-01-01

    A review of recent progress in the field of strained silicon photonics is presented. The application of strain to waveguide and photonic crystal structures can be used to alter the linear and nonlinear optical properties of these devices. Here, methods for the fabrication of strained devices are summarized and recent examples of linear and nonlinear optical devices are discussed. Furthermore, the relation between strain and the enhancement of the second order nonlinear susceptibility is inves...

  1. Martensitic Transformation and Magnetic-Field-Induced Strain in Magnetic Shape Memory Alloy NiMnGa Melt-Spun Ribbon

    Institute of Scientific and Technical Information of China (English)

    Shihai GUO; Yanghuan ZHANG; Jianliang LI; Baiyun QUAN; Yan QI; Xinlin WANG

    2005-01-01

    A magnetic shape memory alloy with nonstoichiometric Ni5oMn27Ga23 was prepared by using melt-spinning technology. The martensitic transformation and the magnetic-field-induced strain (MFIS) of the polycrystalline melt-spun ribbon were investigated. The experimental results showed that the melt-spun ribbons underwent thermal-elastic martensitic transformation and reverse transformation in cooling and heating process and exhibited typical thermoelastic shape memory effect. However the start temperature for martensitic transformation decreased from 286 K for as-cast alloy to 254 K for as-quenched ribbon and Curie temperature remains approximately constant. A particular internal stress induced by melt-spinning resulted in the formation of a texture structure in the ribbons, which made the ribbons obtain larger martensitic transformation strain and MFIS. The internal stress was released substantially after annealing, which resulted in a decrease of MFIS of the ribbons.

  2. Faulting of rocks in three-dimensional strain fields I. Failure of rocks in polyaxial, servo-control experiments

    Science.gov (United States)

    Reches, Z.; Dieterich, J.H.

    1983-01-01

    The dependence of the number of sets of faults and their orientation on the intermediate strain axis is investigated through polyaxial tests, reported here, and theoretical analysis, reported in an accompanying paper. In the experiments, cubic samples of Berea sandstone, Sierra-White and Westerly granites, and Candoro and Solnhofen limestones were loaded on their three pairs of faces by three independent, mutually perpendicular presses at room temperature. Two of the presses were servo-controlled and applied constant displacement rates throughout the experiment. Most samples display three or four sets of faults in orthorhombic symmetry. These faults form in several yielding events that follow a stage of elastic deformation. In many experiments, the maximum and the intermediate compressive stresses interchange orientations during the yielding events, where the corresponding strains are constant. The final stage of most experiments is characterized by slip along the faults. ?? 1983.

  3. Antimicrobial resistance, genotypic characterization and pulsed-field gel electrophoresis typing of extended spectrum β-lactamases-producing clinical Escherichia coli strains in Macao, China

    Institute of Scientific and Technical Information of China (English)

    YE Qian-hong; LAU Ying; LIANG Bin; TIAN Su-fei

    2011-01-01

    Background The rise of the production of CTX-M class extended spectrum β-lactamases (ESBLs) has been well documented in traveling countries but no data are found for Macao,an international travel city.The objectives of this study were to identify the antimicrobial resistance pattern,and determine the prevalence,genotype and clonal relationship of ESBLs in 209 clinical Escherichia coli strains from Macao,China.Methods Antimicrobial susceptibility test was performed to determine the resistance patterns of the isolates using the disk diffusion method with 17 antimicrobial agents.Phenotypic detection was screened and confirmed according to the Clinical and Laboratory Standards Institute.Genotypic characterization was detected by isoelectric focusing analysis,polymerase chain reaction and sequencing.The clonal relationship between the different ESBL isolates was studied by pulsed-field gel electrophoresis (PFGE).Results Imipenem and meropenem exhibited 100% susceptible among 209 strains.Overall,82.3%,67.3%,52.9%,51.2% and 51.0% of the isolates displayed resistance to ampicillin,tetracylcline,ciprofloxacin,sulfamethoxazole trimethoprin and gentamycin.The prevalence rate of ESBLs was 30.1%.Antibiotic resistances were found to be significantly higher among the ESBL producing group compared to non-ESBL producing group.We detected CTX-M-14 to be the major genotypic characterization of ESBLs (76.2%).Two strains showed indistinguishable patterns by PFGE.Conclusions The prevalence of antimicrobial resistance is alarming high in Macao.Antimicrobial resistance is significantly higher among the ESBL producing group.This study documented CTX-M-14 as the predominant ESBL type.Although indistinguishable pattern was found between two strains,it was too small to decide whether any of the investigated strains was epidemic.Our findings may be also pertinent for other geographic areas undergoing similar travel characteristics to understand the corresponding effects on bacterial

  4. New bridge circuit-type detector to measure precise resistance change of strain gauge at low temperature and magnetic field

    OpenAIRE

    Ohashi, Masashi; Kishii, Nobuya; Tateno, Shota

    2016-01-01

    We report a new highly accurate and versatile bridge-circuit-type detector that has a simple structure and demonstrates a low degree of error for measurements of thermal expansion and magnetostriction by the strain gauge method. As an example, a commercial physical property measurement system (PPMS) is combined with a compact bridge-circuit box. Thermal expansion and magnetostriction are calculated from the resistance of the bridge and bridge voltage, measured by the operation of a standard P...

  5. Toxicity of Pyrethroid and Organophosphorous Insecticides against Two Field Collected Strains of the German Cockroach Blattella germanica (Blattaria: Blattellidae)

    OpenAIRE

    Limoee, Mojtaba; Davari, Behroz; Moosa-Kazemi, Seyed Hassan

    2012-01-01

    Background: The German cockroach, Blattella germanica is a major hygienic pest and mechanical vector for pathogenic agents in hospitals and residential areas. The development of insecticide resistance is a serious problem in controlling of this pest. Toxicity of four commonly used insecticides (permethrin, cypermethrin, malathion and chlorpyrifos) against two hospital- collected strains of the German cockroach was investigated. Methods: Topical bioassay methods were carried out for detecting ...

  6. Strain field of interstitial hydrogen atom in body-centered cubic iron and its effect on hydrogen-dislocation interaction

    OpenAIRE

    Wang, Shuai; Takahashi, Keisuke; Hashimoto, Naoyuki; Isobe, Shigehito; Ohnuki, Somei

    2013-01-01

    Effect of hydrogen in body-centered cubic iron is explored by using the density function theory. Hydrogen atoms increase the concentration of free electrons in the simulation cell and have bonding interaction with Fe atom. Caused by anisotropic strain components of hydrogen atoms in the tetrahedral sites, elastic interaction for hydrogen with screw dislocation has been found. The dependence of hydrogen-screw dislocation interaction on hydrogen concentration is confirmed by repeated stress rel...

  7. Several mutations of Zymoseptoria tritici field strains lead to MFS1 overexpression and multi-drug-resistance (MDR)

    OpenAIRE

    Fillinger, Sabine; Omrane, Selim; Audeon, Colette; Ignace, Amandine; Duplaix, Clémentine; Aouini, Lamia; Kema, Gert; Walker, Anne-Sophie

    2016-01-01

    Multidrug resistance (MDR) is a common trait developed by many organisms to counteract chemicals and/or drugs used against them. The basic MDR mechanism is relying on an overexpressed efflux transport system that actively expulses the toxic agent outside the cell. In fungi, MDR (or PDR) has been extensively studied in Saccharomyces cerevisiae and Candida albicans. Plant pathogenic fungi are also concerned by this phenomenon. MDR strains were detected in septoria leaf blotch (Zymoseptoria trit...

  8. Field-induced phase switching and electrically driven strains in sol-gel derived antiferroelectric (Pb,Nb)(Zr,Sn,Ti)O3 thin layers

    International Nuclear Information System (INIS)

    Tin-modified lead zirconate titanate thin layers were prepared by a sol-gel method. A room- temperature antiferroelectric (AFE) phase composition Pb0.99Nb0.02[(Zr0.58Sn0.42)0.96Ti0.04] 0.98O3 was prepared and examined for weak- and high-field dielectric properties as a function of temperature, with emphasis on field-induced AFE-ferroelectric (FE) switching characteristics. Thin layers processed with a lead oxide cover coat were found to be free of any secondary phases and showed improved properties. Room-temperature values of dielectric constant K'=390 and saturation polarization Ps=20 μC/cm2 were obtained with field-induced strains up to 0.15% in submicron grain structures. copyright 1995 American Institute of Physics

  9. Characterization of BoHV-5 field strains circulation and report of transient specific subtype of bovine herpesvirus 5 in Argentina

    Directory of Open Access Journals (Sweden)

    Thiry Julien

    2011-02-01

    Full Text Available Abstract Background Bovine herpesvirus 5 (BoHV-5 is a member of the subfamily Alphaherpesvirinae responsible for meningo-encephalitis in young cattle. The first case of bovine meningo-encephalitis associated with a herpesvirus infection was reported in Australia. The current geographical distribution of BoHV-5 infection is mainly restricted to South America, especially Brazil and Argentina. Outbreaks of BoHV-5 are regularly observed in Argentina suggesting the circulation of the virus in the bovine population. Results Seventeen field strains of BoHV-5 isolated from 1984 to now were confirmed by differential PCR and subjected to restriction endonuclease analysis (REA. Viral DNA was cleaved with BstEII which allows the differentiation among subtypes a, b and non a, non b. According to the REA with BstEII, only one field strain showed a pattern similar to the Argentinean A663 strain (prototype of BoHV-5b. All other isolates showed a clear pattern similar to the Australian N569 strain (prototype of BoHV-5a consistent with the subtypes observed in Brazil, the other South-American country where BoHV-5 is known to be prevalent. The genomic region of subtype b responsible for the distinct pattern was determined and amplified by PCR; specifically a point mutation was identified in glycoprotein B gene, on the BstEII restriction site, which generates the profile specific of BoHV-5b. Conclusions This is the first report of circulation of BoHV-5a in Argentina as the prevailing subtype. Therefore the circulation of BoHV-5b was restricted to a few years in Argentina, speculating that this subtype was not able to be maintained in the bovine population. The mutation in the gB gene is associated with the difference in the restriction patterns between subtypes "a" and "b".

  10. Effects of local field and inherent strain in reflectance anisotropy spectra of A{sup III}B{sup V} semiconductors with naturally oxidized surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Berkovits, V. L.; Kosobukin, V. A.; Gordeeva, A. B. [Ioffe Physical Technical Institute of the Russian Academy of Sciences, 26 Politekhnicheskaya, 194021 Saint Petersburg (Russian Federation)

    2015-12-28

    Reflectance anisotropy (RA) spectra of naturally oxidized (001) surfaces of GaAs and InAs crystals are measured for photon energies from 1.5 up to 5.5 eV. The differential high-accuracy RA spectra reveal features substantially different from those caused by either a reconstruction of clean surface or a built-in near-surface electric field. Models of atomic structure with anisotropic transition layers of excess arsenic atoms specific for GaAs(001)/oxide and InAs(001)/oxide interfaces are proposed. In conformity with these models, a general theory of reflectance anisotropy is developed for semiconductor/oxide interfaces within the Green's function technique. The theory takes into account the combined effect of local field due to interface dipoles and of intrinsic near-surface strain of the crystal. Measured RA spectra are analyzed in the model of valence-bond dipoles occupying a rectangular lattice in a multilayer medium. Comparing the measured and calculated spectra, we conclude that RA spectra of oxidized GaAs(001) and InAs(001) surfaces are simultaneously influenced by interface and near-surface anisotropies. The former is responsible for the broad-band spectral features which are associated with polarizability of the valence bonds attached to As atoms at the crystal/oxide interface. The near-surface anisotropy is due to inherent uniaxial straining the near-surface region of crystal. The effect of strain on RA spectra is experimentally and theoretically substantiated for GaAs crystal wafers undergone a uniaxial applied stress. Basically, this work results in the following. It establishes the physical nature of different levels of RA spectra observed in a majority of papers, but never analyzed. It demonstrates how the studied features of RA spectra could be applied for optical characterization of strained interfaces and atomic layers.

  11. Application of restriction fragment length polymorphism analysis to simple and rapid genotyping of bovine viral diarrhea virus strains isolated in Japan.

    Science.gov (United States)

    Seki, Yoshihisa; Seimiya, Yukio M; Motokawa, Masato; Yaegashi, Gakuji; Nagai, Makoto; Hayashi, Michiko

    2008-04-01

    The E2 regions of 177 bovine viral diarrhea virus (BVDV) strains isolated in Japan between 1957 and 2006 were analyzed for genotyping. The strains were classified into 8 genotypes (1a, 1b, 1c, 1d, 1e, 1f, So and 2a) based on the phylogenetic analysis. The restriction fragment length polymorphism (RFLP) analysis of the RT-PCR products using 6 selected enzymes (Apo I, Mly I, BstAP I, Pvu II, Ear I, EcoR V) disclosed the cutting patterns classified into 11 groups (I-XI), each of that consisted of strains belonging to a single genotype. Namely, groups-I and -II were composed by genotype-1a strains, groups-III and -IV by 1b strains, and groups-V and -VI by 1c strains. Other groups-VII, -VIII, -IX, -X and -XI comprised genotypes-1d, -1e, -1f, -So and -2a strains, respectively. The results suggest that the RFLP analysis can simply and rapidly differentiate the 8 genotypes of BVDV strains.

  12. Electric-field-induced strain contributions in morphotropic phase boundary composition of (Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-BaTiO{sub 3} during poling

    Energy Technology Data Exchange (ETDEWEB)

    Khansur, Neamul H.; Daniels, John E. [School of Materials Science and Engineering, UNSW Australia, New South Wales 2052 (Australia); Hinterstein, Manuel [School of Materials Science and Engineering, UNSW Australia, New South Wales 2052 (Australia); Institute for Applied Materials, Karlsruhe Institute for Technology, P.O. Box 3640, 76021 Karlsruhe (Germany); Wang, Zhiyang [School of Materials Science and Engineering, UNSW Australia, New South Wales 2052 (Australia); The Australian Synchrotron, Clayton, Victoria 3168 (Australia); Groh, Claudia [Institute of Materials Science, Technische Universität Darmstadt, Alarich-Weiss-Straße 2, 64287 Darmstadt (Germany); Jo, Wook [School of Materials Science and Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919 (Korea, Republic of)

    2015-12-14

    The microscopic contributions to the electric-field-induced macroscopic strain in a morphotropic 0.93(Bi{sub 1/2}Na{sub 1/2}TiO{sub 3})−0.07(BaTiO{sub 3}) with a mixed rhombohedral and tetragonal structure have been quantified using full pattern Rietveld refinement of in situ high-energy x-ray diffraction data. The analysis methodology allows a quantification of all strain mechanisms for each phase in a morphotropic composition and is applicable to use in a wide variety of piezoelectric compositions. It is shown that during the poling of this material 24%, 44%, and 32% of the total macroscopic strain is generated from lattice strain, domain switching, and phase transformation strains, respectively. The results also suggest that the tetragonal phase contributes the most to extrinsic domain switching strain, whereas the lattice strain primarily stems from the rhombohedral phase. The analysis also suggests that almost 32% of the total strain is lost or is a one-time effect due to the irreversible nature of the electric-field-induced phase transformation in the current composition. This information is relevant to on-going compositional development strategies to harness the electric-field-induced phase transformation strain of (Bi{sub 1/2}Na{sub 1/2})TiO{sub 3}-based lead-free piezoelectric materials for actuator applications.

  13. Laboratory and field tests of spray-dried and granular formulations of a Bacillus thuringiensis strain with insecticidal activity against the sugarcane borer.

    Science.gov (United States)

    Rosas-García, Ninfa M

    2006-09-01

    Formulations of Bacillus thuringiensis Berliner (Bt) with insecticidal activity against the sugarcane borer, Diatraea saccharalis Fabricius (Lepidoptera: Pyralidae), were developed and tested under laboratory and field conditions. The formulations were prepared using biodegradable polymers such as modified corn starch as an encapsulating agent, gelatin as an adherent, powdered sugarcane as a feeding stimulant and a Bt var. kurstaki GM-34 strain from a non-sugarcane region as the active ingredient. The spore-crystal complex of this strain was mixed at three different concentrations (30, 70 and 100 g kg(-1)) with the other ingredients. The blends were prepared as spray-dried and granular formulations, and then submitted to laboratory tests with two day old larvae of D. saccharalis and field tests in sugarcane crops with natural sugarcane borer infestation. Spray-dried formulations in laboratory bioassays caused mortality near 100% with all three concentrations, and granular formulations caused mortality around 84%. The field tests showed that spray-dried formulations at 70 and 100 g kg(-1) concentrations were as effective as a commercial bioinsectide (Lepinox), while granular formulations were ineffective. PMID:16786544

  14. Field Strain Measurement on the Fiber Scale in Carbon Fiber Reinforced Polymers Using Global Finite-Element Based Digital Image Correlation

    KAUST Repository

    Tao, Ran

    2015-05-01

    Laminated composites are materials with complex architecture made of continuous fibers embedded within a polymeric resin. The properties of the raw materials can vary from one point to another due to different local processing conditions or complex geometrical features for example. A first step towards the identification of these spatially varying material parameters is to image with precision the displacement fields in this complex microstructure when subjected to mechanical loading. This thesis is aimed to accurately measure the displacement and strain fields at the fiber-matrix scale in a cross-ply composite. First, the theories of both local subset-based digital image correlation (DIC) and global finite-element based DIC are outlined. Second, in-situ secondary electron tensile images obtained by scanning electron microscopy (SEM) are post-processed by both DIC techniques. Finally, it is shown that when global DIC is applied with a conformal mesh, it can capture more accurately sharp local variations in the strain fields as it takes into account the underlying microstructure. In comparison to subset-based local DIC, finite-element based global DIC is better suited for capturing gradients across the fiber-matrix interfaces.

  15. The influences of thickness of spacing layer and the elastic anisotropy on the strain fields and band edges of InAs/GaAs conical shaped quantum dots

    Institute of Scientific and Technical Information of China (English)

    Liu Yu-Min; Yu Zhong-Yuan; Ren Xiao-Min

    2009-01-01

    Based on the continuum elastic theory, this paper presents a finite element analysis to investigate the influences of elastic anisotropy and thickness of spacing layer on the strain field distribution and band edges (both conduction band and valence band) of the InAs/GaAs conical shaped quantum dots. To illustrate these effects, we give detailed comparisons with the circumstances of isolated and stacking quantum dot for both anisotropic and isotropic elastic characteristics. The results show that, in realistic materials design and theoretical predication performances of the optoelectronie devices, both the elastic anisotropy and thickness of the spacing layer of stacked quantum dot should be taken into consideration.

  16. Comparison of the prevalence and incidence of infection with bovine virus diarrhoea virus (BVDV) in Denmark and Michigan and association with possible risk factors

    DEFF Research Database (Denmark)

    Houe, H.; Baker, J.C.; Maes, R.K.;

    1995-01-01

    summarized and it was investigated if any of these risk factors had significant effect on the presence of animals persistently infected (PI) with BVDV in the dairy herds. Information on the cattle population density in the 2 areas was obtained from statistical yearbooks. Further information...... for the individual farms on age distribution, housing of animals, herd size, pasturing and purchasing policy was gathered. The prevalence of PI animals was more than 10 times higher in Denmark as compared to Michigan. In herds without PI animals, the annual incidence of seroconversion as calculated from the age...... specific prevalence of antibody carriers varied in most age groups between 20-25% in Denmark and between 5-10% in Michigan. All investigated risk factors except for herd size were in favour of a lower prevalence of infection in Michigan. The use of having animals on pasture and at the same time having...

  17. Field performance of new cowpea cultivars inoculated with efficient nitrogen-fixing rhizobial strains in the Brazilian Semiarid

    Directory of Open Access Journals (Sweden)

    Rita de Cássia Nunes Marinho

    2014-05-01

    Full Text Available The objective of this work was to evaluate the contribution of efficient nitrogen-fixing rhizobial strains to grain yield of new cowpea cultivars, indicated for cultivation in the Brazilian Semiarid region, in the sub-medium of the São Francisco River Valley. Two experiments were set up at the irrigated perimeters of Mandacaru (Juazeiro, state of Bahia and Bebedouro (Petrolina, state of Pernambuco. The treatments consisted of single inoculation of five rhizobial strains - BR 3267, BR 3262, INPA 03-11B, UFLA 03-84 (Bradyrhizobium sp., and BR 3299T (Microvirga vignae -, besides a treatment with nitrogen and a control without inoculation or N application. The following cowpea cultivars were evaluated: BRS Pujante, BRS Tapaihum, BRS Carijó, and BRS Acauã. A randomized complete block design, with four replicates, was used. Inoculated plants showed similar grain yield to the one observed with plants fertilized with 80 kg ha-1 N. The cultivars BRS Tapaihum and BRS Pujante stood out in grain yield and protein contents when inoculated, showing their potential for cultivation in the sub-medium of the São Francisco River Valley.

  18. Single and Low-level Oocyst Infections of Drug-resistant Field Strains of Eimeria tenella in Medicated Birds

    Science.gov (United States)

    Lee, Eng-Hong

    1979-01-01

    Five out of ten birds infected with a single oocyst of strain Gt2 of Eimeria tenella and medicated with the recommended level of robenidine were found positive in the first experiment and four in the second in comparison with seven and six respectively in nonmedicated birds. Six birds out of ten were found positive in the two groups of similarly medicated birds infected with two or four oocysts each. Although single oocyst infections of strain Lilly 155 were unsuccessful, six out of ten birds were found positive in birds infected with ten oocysts each. All single and low-level oocyst infections were accomplished with oocysts previously treated with β-glucuronidase and broken into sporocysts prior to infections. The overall results suggested that when a coccidium became resistant to an anticoccidial drug, only one or a few occysts were needed to start an infection if the drug was continued. The results also showed that, perhaps, successful single or low-level oocyst infections can also be used as a criterion for demonstrating drug resistance in coccidia. PMID:570880

  19. A first modeling of dynamic and static crustal strain field from near-field dilatation measurements: example of the 2013 M_w 6.2 Ruisui earthquake, Taiwan

    Science.gov (United States)

    Canitano, Alexandre; Hsu, Ya-Ju; Lee, Hsin-Ming; Linde, Alan T.; Sacks, Selwyn

    2016-07-01

    We analyze the high-resolution dilatation data for the October 2013 M_w 6.2 Ruisui, Taiwan, earthquake, which occurred at a distance of 15-20 km away from a Sacks-Evertson dilatometer network. Based on well-constrained source parameters (strike=217°, dip=48°, rake=49°), we propose a simple rupture model that explains the permanent static deformation and the dynamic vibrations at short period (˜ 3.5-4.5 s) for most of the four sites with less than 20 % of discrepancies. This study represents a first attempt of modeling simultaneously the dynamic and static crustal strain using dilatation data. The results illustrate the potential for strain recordings of high-frequency seismic waves in the near-field of an earthquake to add constraints on the properties of seismic sources.

  20. Dependence of third-order nonlinear susceptibility on strain induced piezoelectric field in InxGa1-xN/GaN quantum well

    Institute of Scientific and Technical Information of China (English)

    Yaochen Bai(白瑶晨); Jingliang Liu(刘景良); Duanzheng Yao(姚端正)

    2004-01-01

    The third-order susceptibility of InxGa1-xN/GaN quantum well (QW) has been investigated by taking into account the strain-induced piezoelectric (PZ) field, and the effective-mass SchrSdinger equation is solved numerically. It is shovn that the third-order susceptibility for third harmonic generation (THG)of InxGa1-x,N/GaN QW is related to indium content in QW and the intensity of the PZ field. The characteristics ofX(3)THG(-3ω,(3) ω, ω,ω) as the function of the wavelength of incident beam, well width and indium content, have been analyzed.

  1. Bovine viral diarrhea virus: molecular cloning of genomic RNA and its diagnostic application

    Energy Technology Data Exchange (ETDEWEB)

    Brock, K.V.

    1987-01-01

    Molecular cloning of a field isolate of bovine viral diarrhea virus (BVDV) strain 72 RNA was done in this study. The sensitivity and specificity of cloned cDNA sequences in hybridization assays with various BVDV strains were determined. cDNA was synthesized from polyadenylated BVDV RNA templates with oligo-dT primers, reverse transcriptase, and DNA polymerase I. The newly synthesized double-stranded BVDV cDNA was C-tailed with terminal deoxytransferase and annealed into G-tailed, Pst-1-cut pUC9 plasmid. Escherichia coli was transformed with the recombinant plasmids and a library of approximately 200 BVDV specific cDNA clones varying in length from 0.5 to 2.6 kilobases were isolated. The sensitivity and specificity of hybridization between the labelled cDNA and BVDV target sequences were determined. Cloned BVDV sequences were isolated from pUC9 plasmid DNA and labelled with /sup 32/P by nick translation. The detection limit by dot blot hybridization assay was 20 pg of purified genomic BVDV RNA. cDNA hybridization probes were specific for all strains of BVDV tested, regardless of whether they were noncytopathic and cytopathic, but did not hybridize with heterologous bovine viruses tested. Probes did not hybridize with uninfected cell culture or cellular RNA. Hybridization probes were at least as sensitive as infectivity assays in detecting homologous virus.

  2. Bovine viral diarrhea virus: molecular cloning of genomic RNA and its diagnostic application

    International Nuclear Information System (INIS)

    Molecular cloning of a field isolate of bovine viral diarrhea virus (BVDV) strain 72 RNA was done in this study. The sensitivity and specificity of cloned cDNA sequences in hybridization assays with various BVDV strains were determined. cDNA was synthesized from polyadenylated BVDV RNA templates with oligo-dT primers, reverse transcriptase, and DNA polymerase I. The newly synthesized double-stranded BVDV cDNA was C-tailed with terminal deoxytransferase and annealed into G-tailed, Pst-1-cut pUC9 plasmid. Escherichia coli was transformed with the recombinant plasmids and a library of approximately 200 BVDV specific cDNA clones varying in length from 0.5 to 2.6 kilobases were isolated. The sensitivity and specificity of hybridization between the labelled cDNA and BVDV target sequences were determined. Cloned BVDV sequences were isolated from pUC9 plasmid DNA and labelled with 32P by nick translation. The detection limit by dot blot hybridization assay was 20 pg of purified genomic BVDV RNA. cDNA hybridization probes were specific for all strains of BVDV tested, regardless of whether they were noncytopathic and cytopathic, but did not hybridize with heterologous bovine viruses tested. Probes did not hybridize with uninfected cell culture or cellular RNA. Hybridization probes were at least as sensitive as infectivity assays in detecting homologous virus

  3. A novel field transplantation technique reveals intra-specific metal-induced oxidative responses in strains of Ectocarpus siliculosus with different pollution histories.

    Science.gov (United States)

    Sáez, Claudio A; González, Alberto; Contreras, Rodrigo A; Moody, A John; Moenne, Alejandra; Brown, Murray T

    2015-04-01

    A novel field transplantation technique, in which seaweed material is incorporated into dialysis tubing, was used to investigate intra-specific responses to metals in the model brown alga Ectocarpus siliculosus. Metal accumulation in the two strains was similar, with higher concentrations in material deployed to the metal-contaminated site (Ventanas, Chile) than the pristine site (Quintay, Chile). However, the oxidative responses differed. At Ventanas, strain Es147 (from low-polluted site) underwent oxidative damage whereas Es524 (from highly polluted site) was not affected. Concentrations of reduced ascorbate (ASC) and reduced glutathione (GSH) were significantly higher in Es524. Activities of the antioxidant enzymes superoxide dismutase (SOD), ascorbate peroxidase (APX), catalase (CAT), and glutathione reductase (GR) all increased in Es524, whereas only SOD increased in Es147. For the first time, employing a field transplantation technique, we provide unambiguous evidence of inter-population variation of metal-tolerance in brown algae and establish that antioxidant defences are, in part, responsible.

  4. Field induced domain switching as the origin of anomalous lattice strain along non-polar direction in rhombohedral BiScO{sub 3}-PbTiO{sub 3} close to the morphotropic phase boundary

    Energy Technology Data Exchange (ETDEWEB)

    Lalitha, K. V.; Ranjan, Rajeev, E-mail: rajeev@materials.iisc.ernt.in [Department of Materials Engineering, Indian Institute of Science, Bangalore 560012 (India); Fancher, Chris M.; Jones, Jacob L. [Department of Materials Science and Engineering, North Carolina State University, Raleigh, North Carolina 27695 (United States)

    2015-08-03

    The lattice strain and domain switching behavior of xBiScO{sub 3}–(1-x)PbTiO{sub 3} (x = 0.40) was investigated as a function of cyclic field and grain orientation by in situ X-ray diffraction during application of electric fields. The electric field induced 200 lattice strain was measured to be five times larger than the 111 lattice strain in pseudorhombohedral xBiScO{sub 3}–(1-x)PbTiO{sub 3} (x = 0.40). It is shown that the anomalous 200 lattice strain is not an intrinsic phenomenon, but arises primarily due to stress associated with the reorientation of the 111 domains in dense polycrystalline ceramic.

  5. The prevalence of different strains of Rhizoctonia solani associated with Rhizoctonia crown and root rot symptoms in Ontario sugarbeet fields

    Science.gov (United States)

    Rhizoctonia crown and root rot (RCRR) [Rhizoctonia solani Kühn] is an important disease of sugarbeets in southwestern Ontario, Canada. A survey of commercial sugarbeet fields was completed in 2010 and 2011 to determine the range of R. solani anastomosis groups (AGs) and inter-specific groups (ISGs) ...

  6. Near-Field High-Resolution Seismic, Strain and Displacement Measurements for Earthquake Source Studies in Deep Mines in South Africa

    Science.gov (United States)

    Johnston, M. J.; Reches, Z.; van Aswegan, G.; McGarr, A.; Lockner, D.; Sellers, E.; Ben Zion, Y.; Williams, C.

    2004-12-01

    Unique access to information on the physics of the earthquake source (earthquake nucleation, fault rupture, heat generation, stress state, seismic wave propagation, fault displacement, material properties and particularly changes in some of these parameters prior to rupture) exists in the near-field of mining-induced earthquakes in deep gold mines in South Africa. The new NSF funded Natural Earthquake Laboratory in South African Mines (NELSAM) will provide seismic velocity/acceleration, ground strain, temperature, fault displacement, acoustic emission (AE), and perhaps self-potential (SP) data in small 3-D arrays across and within active faults in two different mines. 3-component accelerometers to be installed in or near the faults have a range from micro g to 0.5 g in the band 0.05 - 500 Hz. Fault displacement meters (creepmeters) to be installed at low angles across faults within boreholes have a range of microns to 0.2 m and cover the frequency range from DC to 100 Hz. Successful measurement of total displacement will depend on the creepmeter reference length surviving the fault rupture. Temperature will be measured to millidegrees C at points within, and at increasing distances from fault zones, to capture the heat generated by future and past earthquakes. Strain transients will be measured with 3-component near-fault borehole strainmeters with capacitance displacement transducers providing a resolution transducers will be installed together with each accelerometer and supplement the current mine seismic network. AE and SP will be measured within boreholes crossing faults if recording capability is sufficient. All data will be digitally sampled and transmitted to the surface in real-time for analysis to focus on unraveling the physics of the nucleation process, non-linear deformation prior to rupture, propagating aseismic slip, and variation in the material properties of near-fault materials (e.g. state/rate dependent friction). Similar high-resolution borehole

  7. Achieving high performance electric field induced strain: a rational design of hyperbranched aromatic polyamide functionalized graphene-polyurethane dielectric elastomer composites.

    Science.gov (United States)

    Chen, Tian; Qiu, Jinhao; Zhu, Kongjun; Li, Jinhuan; Wang, Jingwen; Li, Shuqin; Wang, Xiaoliang

    2015-03-26

    Dielectric elastomers have great potentials as flexible actuators in micro-electromechanical systems (MEMS) due to their large deformation, light weight, mechanical compliancy, and low cost. The low dielectric constant of these elastomers requires a rather high voltage electric field, which has greatly limited their applications. In this work, a diaphragm-type flexible microactuator comprising a hyperbranched aromatic polyamide functionalized graphene (HAPFG) filler embedded into the polyurethane (PU) dielectric elastomer matrix is described. The rational designed HAPFG sheets exhibits uniform dispersion in PU matrix and strong adhesion with the matrix by hydrogen-bond coupling. Consequently, the HAPFG-PU composites possess high dielectric performance and low loss modulus. The effect of hyperbranched aromatic polyamide functionalized graphene on high voltage electric field induced strain was experimentally investigated using the Fotonic sensor. The high electric field response of the composite was discussed by applying different kinds of alternating-current field. In addition, a comparison of the breakdown strength between the HAPFG-PU composite and the pure PU was carried out. PMID:25741878

  8. Strain fields in histological slices of brain tissue determined by synchrotron radiation-based micro computed tomography.

    Science.gov (United States)

    Germann, Marco; Morel, Anne; Beckmann, Felix; Andronache, Adrian; Jeanmonod, Daniel; Müller, Bert

    2008-05-15

    Accurate knowledge of the morphology of the human brain is required for minimally or non-invasive surgical interventions. On the (sub-)cellular level, brain tissue is generally characterized using optical microscopy, which allows extracting morphological features with a wide spectrum of staining procedures. The preparation of the histological slices, however, often leads to artifacts resulting in imperfect morphological data. In addition, the generation of 3D data is time-consuming. Therefore, we propose synchrotron radiation-based micro computed tomography (SRmicroCT) avoiding preparation artifacts and giving rise to the 3D morphology of features such as gray and white matter on the micrometer level. One can differentiate between white and gray matter without any staining procedure because of different X-ray absorption values. At the photon energy of 10keV, the white matter exhibits the absorption of 5.08 cm(-1), whereby the value for the gray matter corresponds to 5.25 cm(-1). The tomography data allow quantifying the local strains in the histological images using registration algorithms. The deformation of histological slices compared to the SRmicroCT in a 2D-2D registration leads to values of up to 6.3%. Mean deformation values for the Nissl-stained slices are determined to about 1%, whereas the myelin-stained slices yield slightly higher values than 2%.

  9. FEA modeling of effect of axial feeding velocity on strain field of rotary swaging process of pure magnesium

    Institute of Scientific and Technical Information of China (English)

    RONG Li; NIE Zuo-ren; ZUO Tie-yong

    2006-01-01

    A coupled thermal-mechanical model of the rotary swaging of pure magnesium was developed using the general finite-element software program MSC/Marc to visualize the effect of axial feeding velocity on the rotary swaging process. The radial displacement occurring in one pulse impact increases in proportion to axial feeding velocity (vax). When the other processing parameters are fixed, the surface roughness of the swaged bar increases with vax and is in parabolic relation with vax. There exists a minimum velocity vax, min below which the decrease of vax will no longer improve the surface roughness. Under the technological conditions of this simulation, when the finial diameter d=6.6 mm, vax, min=1.82 m/min, and when d=7.0 mm, vax, min=1.83 m/min. If Ra=3.2 is required for the end product, then vax, max=6.02 m/min is gotten for d=6.6 mm and vax, max=7.05 m/min for d=7.0mm. The increase of vax has no notable influence on strain distribution along radial direction. The errors between the experimental and simulated height of the spiral spine-like ridges are below 8.0%.

  10. New method of determination of spot welding-adhesive joint fatigue life using full field strain evolution

    Science.gov (United States)

    Sadowski, T.; Kneć, M.

    2016-04-01

    Fatigue tests were conducted since more than two hundred years ago. Despite this long period, as fatigue phenomena are very complex, assessment of fatigue response of standard materials or composites still requires a long time. Quite precise way to estimate fatigue parameters is to test at least 30 standardized specimens for the analysed material and further statistical post processing is required. In case of structural elements analysis like hybrid joints (Figure 1), the situation is much more complex as more factors influence the fatigue load capacity due to much more complicated structure of the joint in comparison to standard materials specimen, i.e. occurrence of: welded hot spots or rivets, adhesive layers, local notches creating the stress concentrations, etc. In order to shorten testing time some rapid methods are known: Locati's method [1] - step by step load increments up to failure, Prot's method [2] - constant increase of the load amplitude up to failure; Lehr's method [2] - seeking for the point during regular fatigue loading when an increase of temperature or strains become non-linear. The present article proposes new method of the fatigue response assessment - combination of the Locati's and Lehr's method.

  11. 2D Ball-and-Socket Tectonic Rotation in a Heterogeneous Strain Field: The 2013 Mw7.7 Balochistan, Pakistan Earthquake

    Science.gov (United States)

    Barnhart, W. D.; Hayes, G. P.; Briggs, R. W.; Gold, R. D.; Bilham, R. G.

    2014-12-01

    The September 2013 Mw7.7 Balochistan strike-slip earthquake ruptured a ~200 km long segment of the curved Hoshab fault within the Makran accretionary prism - the active zone of convergence between the northward subducting Arabia plate and overriding Eurasia. The Hoshab fault ruptured bilaterally with ~10 m of mean sinistral and ~1.7 m of dip slip along the length of the rupture, quantified jointly from geodetic and seismological observations. This rupture is unusual because the fault dips ~60o towards the focus of a small circle centered in northwest Pakistan, and, despite a 30o increase in obliquity along the curving strike of the fault with respect to Arabia:Eurasia convergence, the ratio of strike and dip slip remain relatively uniform. Static friction prior to rupture was unusually weak ( <0.05) as inferred from topographic and slab profiles, and friction may have approached zero during dynamic rupture, thus permitting in part this unusual event. In this presentation, we argue that the northward dipping Hosab fault defines the northern rim of a structural unit in southeast Makran. This unit rotates - akin to a 2-D ball-and-socket joint - counter clockwise in response to India's penetration into the Eurasia plate. According to this interpretation, the mechanically weak Makran accretionary prism is subjected to a highly heterogeneous strain and deforms in response to convergence from both the Arabia and India plates. Rotation of the southeast Makran block accounts for complexity in the Chaman fault system and, in principle, reduces the seismic potential near Karachi by accommodating some slip along the southern Ornach-Nal fault. At the same time, geological indicators and along-strike fault slip profiles indicate that the Hoshab fault may also slip as a reverse fault in response to Arabia:Eurasia convergence - indicating that a single fault may accommodate multiple components of strain partitioning in a heterogeneous strain field over several seismic cycles.

  12. Transient rheological behavior of natural polysaccharide xanthan gum solutions in start-up shear flow fields: An experimental study using a strain-controlled rheometer

    Science.gov (United States)

    Lee, Ji-Seok; Kim, Yong-Seok; Song, Ki-Won

    2015-08-01

    The objective of the present study is to experimentally investigate the transient rheological behavior of concentrated xanthan gum solutions in start-up shear flow fields. Using a strain-controlled rheometer, a number of constant shear rates were suddenly imposed to aqueous xanthan gum solutions with different concentrations and the resultant shear stress responses were measured with time. The main findings obtained from this study can be summarized as follows: (1) For all shear rates imposed, however low it may be, the shear stress is rapidly increased with time (stress overshoot) upon inception of steady shear flow before passing through the maximum stress value and then gradually decreased with time (stress decay) until reaching a steady state flow. (2) As the imposed shear rate is increased, a more pronounced stress overshoot takes place and the maximum stress value becomes larger, whereas both times at which the maximum stress is observed and needed to reach a steady state flow are shortened. (3) The maximum shear stress is linearly increased with shear rate in a double logarithmic scale and becomes larger with increasing concentration at equal shear rates. In addition, the time at which the maximum stress occurs exhibits a linear relationship with the inverse of shear rate in a double logarithmic scale for all xanthan gum solutions, regardless of their concentrations. (4) The shear stress is sharply increased with an increase in strain until reaching the maximum stress at small range of deformations. The maximum stress is observed at similar strain values, irrespective of the imposed shear rates lower than 10 1/s. (5) The Bird-Leider model can be successfully used with regard to quantitatively predicting the transient behavior of concentrated xanthan gum solutions. However, this model has a fatal weakness in terms of describing a decrease in shear stress (stress decay).

  13. Diffraction tomography of strain

    OpenAIRE

    Lionheart, W R B; Withers, P. J.

    2015-01-01

    We consider whether it is possible to recover the three dimensional strain field tomographically from neutron and x-ray diffraction data for polycrystalline materials. We show that the distribution of strain transverse to a ray cannot be deduced from one diffraction pattern accumulated along that path, but that a certain moment of that data corresponds to the transverse ray transform of the strain tensor and so may be recovered by inverting that transform given sufficient data. We show that t...

  14. Multiphasic characterization of a plant growth promoting bacterial strain, Burkholderia sp, 7016 and its effect on tomato growth in the field

    Institute of Scientific and Technical Information of China (English)

    GAO Miao[1; ZHOU Jian-jiao[1; WANG En-tao[2; CHEN Qian[1; XU Jing[1; SUN Jian-guana[1

    2015-01-01

    Aiming at searching for plant growth promoting rhizobacteria (PGPR), a bacterium strain coded as 7016 was isolated from soybean rhizosphere and was characterized in the present study. It was identified as Burkholderia sp. based on 16S rDNA sequence analysis, as well as phenotypic and biochemical characterizations. This bacterium presented nitrogenase activity, 1-aminocyclopropane-l-carboxylic acid (ACC) deaminase activity and phosphate solubilizing ability; inhibited the growth of Sclerotinia sclerotiorum, Gibberella zeae and Verticillium dahliae; and produced small quantities of indole acetic acid (IAA). In green house experiments, significant increases in shoot height and weight, root length and weight, and stem diameter were observed on tomato plants in 30 d after inoculation with strain 7016. Result of 16S rDNA PCR-DGGE showed that 7016 survived in the rhizosphere of tomato seedlings. In the field experiments, Burkholderia sp. 7016 enhanced the tomato yield and significantly promoted activities of soil urease, phosphatase, sucrase, and catalase. All these results demonstrated Burkholderia sp. 7016 as a valuable PGPR and a candidate of biofertilizer.

  15. Capsid proteins from field strains of foot-and-mouth disease virus confer a pathogenic phenotype in cattle on an attenuated, cell-culture-adapted virus

    DEFF Research Database (Denmark)

    Bøtner, Anette; Kakker, Naresh K.; Barbezange, Cyril;

    2011-01-01

    cells than the rescued parental O1K B64 virus. The two chimeric viruses displayed the expected antigenicity in serotype-specific antigen ELISAs. Following inoculation of each virus into cattle, the rescued O1K B64 strain proved to be attenuated whereas, with each chimeric virus, typical clinical signs......Chimeric foot-and-mouth disease viruses (FMDVs) have been generated from plasmids containing full-length FMDV cDNAs and characterized. The parental virus cDNA was derived from the cell-culture-adapted O1Kaufbeuren B64 (O1K B64) strain. Chimeric viruses, containing capsid coding sequences derived...... from the O/UKG/34/2001 or A/Turkey 2/2006 field viruses, were constructed using the backbone from the O1K B64 cDNA, and viable viruses (O1K/O-UKG and O1K/A-Tur, respectively) were successfully rescued in each case. These viruses grew well in primary bovine thyroid cells but grew less efficiently in BHK...

  16. Effect of Trichoderma harzianum biomass and Bradyrhizobium sp. strain NC 92 to control leaf blight disease of bambara groundnut (Vigna subterranea caused by Rhizoctonia solani in the field

    Directory of Open Access Journals (Sweden)

    Mana Kanjanamaneesathian

    2007-01-01

    Full Text Available Four hundred and sixty two strains of Trichoderma spp. were isolated from 23 soil samples in which groundnut (Arachis hypogaea L. and bambara groundnut (Vigna subterranea L. had been planted in Songkhla, Phattalung, Nakhon Si Thammarat, Narathiwat and Yala provinces. These fungi were tested against Rhizoctonia solani, a causal agent of leaf blight of bambara groundnut, using dual culture technique on PDA medium. Among 462 isolates tested, 226 isolates had an ability to overgrow R. solani completely. Further testing found 13 isolates having the ability to parasitize mycelia of R. solani. Among these isolates, ThB-1-54 produced a cellulolytic enzyme on congo-red agar. This isolate was later identified as T. harzianum Rifai. In the field test, applying biomass of the isolate ThB-1-54 cultured on ground mesocarp fiber of oil palm, the combination of the isolate ThB-1-54 on ground mesocarp fiber of oil palm and Bradyrhizobium sp. (strain NC 92, or fungicide (iprodione had no effect on disease severity, yield, or the amount of total nitrogen content in stems or seeds of bambara groundnut plant.

  17. Field performance of Alnus cordata Loisel (Italian alder) inoculated with Frankia and VA-mycorrhizal strains in mine-spoil afforestation plots

    Energy Technology Data Exchange (ETDEWEB)

    Lumini, E.; Bosco, M.; Puppi, G.; Isopi, R.; Frattegiani, M.; Burseti, E.; Favili, F.

    1994-05-01

    Mixed stands of {ital Alnus cordata}, {ital Eleagnus} spp. and broad leaf timber trees have been successfully used for reclamation of mine spoils in surface mined areas of central Italy. Trials showed that the use of mycorrhizal planting stock may improve the establishment of plants on mine spoils. Alder seeds were sown in pots filled with peat moss and lignite mine spoils and Fungal strains {ital Glomus mosscae} and {ital G. fasciculatum} were inoculated into the pots. A Frankia strain isolated from {ital A. cordata} was also tested. Plants were then outplanted after measuring shoot height and collar diameter. The planting was done in mid-January among commercial trees ({ital Quercus robur}, {ital Fraxinus oxyphilla}, and {ital Prunus avium}). Plants became highly nodulated in the pots. Mycorrhizal infection was about 30% on inoculate plants but did not occur on uninoculated plants. Aboveground biomass at out-planting was significantly greater in the Frankia inoculated plants. There was generally more N in plant leaves in the inoculate plants than in the uninoculated ones. Plant survival in the field after one winter was 83% on average. One year after planting, the inoculated plants were significantly bigger as were the Frankia inoculated plants. The combination of Frankia and Glomus was very effective (contrary to other studies).

  18. A three dimensional field formulation, and isogeometric solutions to point and line defects using Toupin's theory of gradient elasticity at finite strains

    Science.gov (United States)

    Wang, Z.; Rudraraju, S.; Garikipati, K.

    2016-09-01

    We present a field formulation for defects that draws from the classical representation of the cores as force dipoles. We write these dipoles as singular distributions. Exploiting the key insight that the variational setting is the only appropriate one for the theory of distributions, we arrive at universally applicable weak forms for defects in nonlinear elasticity. Remarkably, the standard, Galerkin finite element method yields numerical solutions for the elastic fields of defects that, when parameterized suitably, match very well with classical, linearized elasticity solutions. The true potential of our approach, however, lies in its easy extension to generate solutions to elastic fields of defects in the regime of nonlinear elasticity, and even more notably for Toupin's theory of gradient elasticity at finite strains (Toupin Arch. Ration. Mech. Anal., 11 (1962) 385). In computing these solutions we adopt recent numerical work on an isogeometric analytic framework that enabled the first three-dimensional solutions to general boundary value problems of Toupin's theory (Rudraraju et al. Comput. Methods Appl. Mech. Eng., 278 (2014) 705). We first present exhaustive solutions to point defects, edge and screw dislocations, and a study on the energetics of interacting dislocations. Then, to demonstrate the generality and potential of our treatment, we apply it to other complex dislocation configurations, including loops and low-angle grain boundaries.

  19. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama. Annual report, March 1996--March 1997

    Energy Technology Data Exchange (ETDEWEB)

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Groshong, R.H.

    1997-08-01

    Gilbertown Field is the oldest oil field in Alabama and produces oil from chalk of the Upper Cretaceous Selma Group and from sandstone of the Eutaw Formation along the southern margin of the Gilbertown fault system. Most of the field has been in primary recovery since establishment, but production has declined to marginally economic levels. This investigation applies advanced geologic concepts designed to aid implementation of improved recovery programs. The Gilbertown fault system is detached at the base of Jurassic salt. The fault system began forming as a half graben and evolved in to a full graben by the Late Cretaceous. Conventional trapping mechanisms are effective in Eutaw sandstone, whereas oil in Selma chalk is trapped in faults and fault-related fractures. Burial modeling establishes that the subsidence history of the Gilbertown area is typical of extensional basins and includes a major component of sediment loading and compaction. Surface mapping and fracture analysis indicate that faults offset strata as young as Miocene and that joints may be related to regional uplift postdating fault movement. Preliminary balanced structural models of the Gilbertown fault system indicate that synsedimentary growth factors need to be incorporated into the basic equations of area balance to model strain and predict fractures in Selma and Eutaw reservoirs.

  20. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama. Final report, March 1996--September 1998

    Energy Technology Data Exchange (ETDEWEB)

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Carroll, R.E.; Groshong, R.H.; Jin, G.

    1998-12-01

    This project was designed to analyze the structure of Mesozoic and Tertiary strata in Gilbertown Field and adjacent areas to suggest ways in which oil recovery can be improved. The Eutaw Formation comprises 7 major flow units and is dominated by low-resistivity, low-contrast play that is difficult to characterize quantitatively. Selma chalk produces strictly from fault-related fractures that were mineralized as warm fluid migrated from deep sources. Resistivity, dipmeter, and fracture identification logs corroborate that deformation is concentrated in the hanging-wall drag zones. New area balancing techniques were developed to characterize growth strata and confirm that strain is concentrated in hanging-wall drag zones. Curvature analysis indicates that the faults contain numerous fault bends that influence fracture distribution. Eutaw oil is produced strictly from footwall uplifts, whereas Selma oil is produced from fault-related fractures. Clay smear and mineralization may be significant trapping mechanisms in the Eutaw Formation. The critical seal for Selma reservoirs, by contrast, is where Tertiary clay in the hanging wall is juxtaposed with poorly fractured Selma chalk in the footwall. Gilbertown Field can be revitalized by infill drilling and recompletion of existing wells. Directional drilling may be a viable technique for recovering untapped oil from Selma chalk. Revitalization is now underway, and the first new production wells since 1985 are being drilled in the western part of the field.

  1. A nationwide database linking information on the hosts with sequence data of their virus strains: A useful tool for the eradication of bovine viral diarrhea (BVD) in Switzerland.

    Science.gov (United States)

    Stalder, Hanspeter; Hug, Corinne; Zanoni, Reto; Vogt, Hans-Rudolf; Peterhans, Ernst; Schweizer, Matthias; Bachofen, Claudia

    2016-06-15

    Pestiviruses infect a wide variety of animals of the order Artiodactyla, with bovine viral diarrhea virus (BVDV) being an economically important pathogen of livestock globally. BVDV is maintained in the cattle population by infecting fetuses early in gestation and, thus, by generating persistently infected (PI) animals that efficiently transmit the virus throughout their lifetime. In 2008, Switzerland started a national control campaign with the aim to eradicate BVDV from all bovines in the country by searching for and eliminating every PI cattle. Different from previous eradication programs, all animals of the entire population were tested for virus within one year, followed by testing each newborn calf in the subsequent four years. Overall, 3,855,814 animals were tested from 2008 through 2011, 20,553 of which returned an initial BVDV-positive result. We were able to obtain samples from at least 36% of all initially positive tested animals. We sequenced the 5' untranslated region (UTR) of more than 7400 pestiviral strains and compiled the sequence data in a database together with an array of information on the PI animals, among others, the location of the farm in which they were born, their dams, and the locations where the animals had lived. To our knowledge, this is the largest database combining viral sequences with animal data of an endemic viral disease. Using unique identification tags, the different datasets within the database were connected to run diverse molecular epidemiological analyses. The large sets of animal and sequence data made it possible to run analyses in both directions, i.e., starting from a likely epidemiological link, or starting from related sequences. We present the results of three epidemiological investigations in detail and a compilation of 122 individual investigations that show the usefulness of such a database in a country-wide BVD eradication program.

  2. A nationwide database linking information on the hosts with sequence data of their virus strains: A useful tool for the eradication of bovine viral diarrhea (BVD) in Switzerland.

    Science.gov (United States)

    Stalder, Hanspeter; Hug, Corinne; Zanoni, Reto; Vogt, Hans-Rudolf; Peterhans, Ernst; Schweizer, Matthias; Bachofen, Claudia

    2016-06-15

    Pestiviruses infect a wide variety of animals of the order Artiodactyla, with bovine viral diarrhea virus (BVDV) being an economically important pathogen of livestock globally. BVDV is maintained in the cattle population by infecting fetuses early in gestation and, thus, by generating persistently infected (PI) animals that efficiently transmit the virus throughout their lifetime. In 2008, Switzerland started a national control campaign with the aim to eradicate BVDV from all bovines in the country by searching for and eliminating every PI cattle. Different from previous eradication programs, all animals of the entire population were tested for virus within one year, followed by testing each newborn calf in the subsequent four years. Overall, 3,855,814 animals were tested from 2008 through 2011, 20,553 of which returned an initial BVDV-positive result. We were able to obtain samples from at least 36% of all initially positive tested animals. We sequenced the 5' untranslated region (UTR) of more than 7400 pestiviral strains and compiled the sequence data in a database together with an array of information on the PI animals, among others, the location of the farm in which they were born, their dams, and the locations where the animals had lived. To our knowledge, this is the largest database combining viral sequences with animal data of an endemic viral disease. Using unique identification tags, the different datasets within the database were connected to run diverse molecular epidemiological analyses. The large sets of animal and sequence data made it possible to run analyses in both directions, i.e., starting from a likely epidemiological link, or starting from related sequences. We present the results of three epidemiological investigations in detail and a compilation of 122 individual investigations that show the usefulness of such a database in a country-wide BVD eradication program. PMID:26403669

  3. Finite Element Analysis of Magnetic Microparticle Induced Strain on a Fibrin Matrix due to the Influence of an Electromagnetic Field

    CERN Document Server

    Averett, Rodney D; Scogin, Tyler; Walker, Mitchell L R

    2016-01-01

    Blood clots occur in the human body when they are required to prevent bleeding. In pathological states such as diabetes and sickle cell disease, blood clots can also form undesirably due to hypercoagulable plasma conditions. With the continued effort in developing fibrin therapies for potential life-saving solutions, more mechanical modeling is needed to understand the properties of fibrin structures with inclusions. In this study, a fibrin matrix embedded with magnetic micro particles was subjected to a magnetic field to determine the plastic deformation of the clot. Using finite element analysis, we estimate the magnetic force from an electromagnet at a sample space located approximately 3 cm away from the coil center. This electromagnetic force along with gravity is applied on a fibrin sub model to calculate the stresses and displacements. Initial analyses show the forces are not sufficient to create fibrinolysis and hence we extended the study using parametric sweep analysis and redesign the coil paramete...

  4. Strain localization along the Main Boundary Thrust (MBT) zone in the Eastern Himalaya: insights from field and experimental studies

    Science.gov (United States)

    Ghosh, Subhajit; Bose, Santanu; Mandal, Nibir

    2016-04-01

    The southward tapering Himalayan tectonic wedge is sliding over the upper boundary of the subducting Indian crust that act as the basal low angle detachment fault, known as the Main Himalayan Thrust (MHT). It is now established that at least four crustal-scale south verging thrust faults, such as Main Central Thrust (MCT), Daling Thrust (~ Ramgarh Thrust ~ Shumar Thrust) (DT), Main Boundary Thrust (MBT) and Main Frontal Thrust (MFT), have emerged from the MHT, striking the entire length of Himalayan mountain belts. These structures accommodated hundreds of kilometers of crustal shortening since India-Asia collision and eventually, juxtaposed different tectono-metamorphic rocks in their hanging wall. Field investigations reveal increased number of thrust faults towards the frontal Himalayan mountain belts and their spacing between the successive thrusts are relatively small in contrast to the hinterland part of the mountain belt. For example, in the Eastern Himalayan belt the MBT zone in the Lesser Himalayan Sequence is marked by several such closely spaced thrusts. The present work is aimed to delineate factors that likely to have influenced for the development of such high frequency thrusting. Employing the model of Coulomb Wedge Theory (CWT), several researchers have shown that spacing between two consecutive thrusts is a function of basal friction and pore fluid pressure ratio. However, this model does not explain the cause of closely spaced thrust localization towards the frontal mountain belts during the wedge growth. Our present study using field relations and physical modeling shows that relative strength difference between the basal low angle detachment fault and the interface-strength of the varying lithology of the cover rocks has a major role for such thrust localization with narrow thrust spacing. Moreover, our findings may become useful for structural interpretation for the localization of Main Boundary Thrust zone in the frontal Himalayan mountain

  5. Pulsed-Field Gel Electrophoresis Typing of Escherichia coli Strains from Samples Collected before and after Pivmecillinam or Placebo Treatment of Uncomplicated Community-Acquired Urinary Tract Infection in Women

    OpenAIRE

    Ejrnaes, Karen; Sandvang, Dorthe; Lundgren, Bettina; Ferry, Sven; Holm, Stig; Monsen, Tor; Lundholm, Rolf; Frimodt-Moller, Niels

    2006-01-01

    The primary infecting Escherichia coli strains from 156 women with community-acquired uncomplicated urinary tract infection (UTI) randomized to pivmecillinam or placebo and the E. coli strains causing UTI at two follow-up visits were typed using pulsed-field gel electrophoresis (PFGE). In the pivmecillinam treatment group PFGE showed that among patients having a negative urine culture at the first follow-up 77% (46/60) had a relapse with the primary infecting E. coli strain and 23% (14/60) ha...

  6. Caracterização de cepas de referência de Leptospira sp utilizando a técnica de pulsed field gel electrophoresis Characterization of Leptospira sp reference strains using the pulsed field gel electrophoresis technique

    Directory of Open Access Journals (Sweden)

    Lívia Machry

    2010-04-01

    Full Text Available INTRODUÇÃO: A leptospirose é uma zoonose endêmica, mundialmente distribuída, causada por bactérias do gênero Leptospira. Este gênero compreende espécies patogênicas e saprofíticas, com mais de 200 sorovares distintos, dificultando sua caracterização. A técnica de pulsed field gel electrophoresis tem sido empregada como uma ferramenta para auxiliar nesta caracterização. Os objetivos deste trabalho foram padronizar a técnica de PFGE, determinar os perfis moleculares das cepas de referência utilizadas pelo Laboratório de Referência Nacional para Leptospirose/Centro Colaborador da Organização Mundial de Saúde para Leptospirose e criar um banco de dados com estes perfis. MÉTODOS: Foram analisadas, por PFGE, dezenove cepas utilizando a enzima de restrição NotI. RESULTADOS: Cada cepa apresentou um perfil único que pode ser considerado como uma identidade genômica específica, com exceção dos sorovares Icterohaemorrhagiae e Copenhageni, cujos perfis foram indistinguíveis. CONCLUSÕES: Dessa forma, foi possível a criação de um banco de perfis moleculares que está sendo utilizado no Laboratório para a comparação e identificação de cepas isoladas de quadros clínicos.INTRODUCTION: Leptospirosis is an endemic zoonosis of worldwide distribution, caused by bacteria of the genus Leptospira. This genus includes pathogenic and saprophytic species, with more than 200 different serovars, thus making it difficult to characterize. The technique of pulsed field gel electrophoresis has been used as a tool to aid in this characterization. The aims of this study were to standardize the PFGE technique, determine the molecular profiles of reference strains used at the National Reference Laboratory for Leptospirosis/World Health Organization Collaborating Center for Leptospirosis and create a database with these profiles. METHODS: Nineteen strains were analyzed by means of PFGE, using the restriction enzyme NotI. RESULTS: Each strain

  7. Multilocus Variable-Number Tandem-Repeat Analysis, Pulsed-Field Gel Electrophoresis, and Antimicrobial Susceptibility Patterns in Discrimination of Sporadic and Outbreak-Related Strains of Yersinia enterocolitica

    Directory of Open Access Journals (Sweden)

    Skurnik Mikael

    2011-02-01

    Full Text Available Abstract Background We assessed the potential of multilocus variable-number tandem-repeat analysis (MLVA, pulsed-field gel electrophoresis (PFGE, and antimicrobial susceptibility testing for discriminating 104 sporadic and outbreak-related Yersinia enterocolitica (YE bio/serotype 3-4/O:3 and 2/O:9 isolates. MLVA using six VNTR markers was performed in two separate multiplex PCRs, and the fluorescently labeled PCR products were accurately sized on an automated DNA sequencer. Results MLVA discriminated 82 sporadic YE 3-4/O:3 and 2/O:9 strains into 77 types, whereas PFGE with the restriction enzyme NotI discriminated the strains into 23 different PFGE pulsotypes. The discriminatory index for a sporadic strain was 0.862 for PFGE and 0.999 for MLVA. MLVA confirmed that a foodborne outbreak in the city of Kotka, Finland in 2003 had been caused by a multiresistant YE 4/O:3 strain that was distinctly different from those of epidemiologically unrelated strains with an identical PFGE pulsotype. The multiresistance of Y. enterocolitica strains (19% of the sporadic strains correlated significantly (p = 0.002 with travel abroad. All of the multiresistant Y. enterocolitica strains belonged to four PFGE pulsotypes that did not contain any susceptible strains. Resistance to nalidixic acid was related to changes in codons 83 or 87 that stemmed from mutations in the gyrA gene. The conjugation experiments demonstrated that resistance to CHL, STR, and SUL was carried by a conjugative plasmid. Conclusions MLVA using six loci had better discriminatory power than PFGE with the NotI enzyme. MLVA was also a less labor-intensive method than PFGE and the results were easier to analyze. The conjugation experiments demonstrated that a resistance plasmid can easily be transferred between Y. enterocolitica strains. Antimicrobial multiresistance of Y. enterocolitica strains was significantly associated with travel abroad.

  8. Strained Silicon Photonics

    Directory of Open Access Journals (Sweden)

    Ralf B. Wehrspohn

    2012-05-01

    Full Text Available A review of recent progress in the field of strained silicon photonics is presented. The application of strain to waveguide and photonic crystal structures can be used to alter the linear and nonlinear optical properties of these devices. Here, methods for the fabrication of strained devices are summarized and recent examples of linear and nonlinear optical devices are discussed. Furthermore, the relation between strain and the enhancement of the second order nonlinear susceptibility is investigated, which may enable the construction of optically active photonic devices made of silicon.

  9. Strain-engineered MOSFETs

    CERN Document Server

    Maiti, CK

    2012-01-01

    Currently strain engineering is the main technique used to enhance the performance of advanced silicon-based metal-oxide-semiconductor field-effect transistors (MOSFETs). Written from an engineering application standpoint, Strain-Engineered MOSFETs introduces promising strain techniques to fabricate strain-engineered MOSFETs and to methods to assess the applications of these techniques. The book provides the background and physical insight needed to understand new and future developments in the modeling and design of n- and p-MOSFETs at nanoscale. This book focuses on recent developments in st

  10. Detección de anticuerpos para BVDV y BoHV-1 en llamas de la región de Tandil - Provincia de Buenos Aires Detection of antibodies to BVDV and BoHV-1 in llamas from Tandil - Province of Buenos Aires

    Directory of Open Access Journals (Sweden)

    P.E. Morán

    2010-12-01

    Full Text Available La llama (Lama glama es la especie predominante de camélidos sudamericanos de la República Argentina, con una población aproximada de 200.000 animales. El aumento de la actividad productiva ha incrementado el transporte y la distribución de animales hacia diferentes regiones del país. Como consecuencia, estas especies interactúan con el ganado doméstico posibilitando la diseminación de agentes infecciosos propios y comunes entre especies. Considerando que los camélidos sudamericanos son susceptibles a la infección con pestivirus y herpesvirus, se planteó realizar un relevamiento serológico de anticuerpos neutralizantes para el virus de la diarrea viral bovina (BVDV y el herpesvirus bovino 1 (BoHV-1. Se analizaron 49 animales de dos rebaños de llamas de la región de Tandil mediante la técnica de seroneutralización sobre cultivos celulares de la línea Madin Darby Bovine Kidney. El 22% (11/49 de los animales expresaron seropositividad a BoHV-1, mientras que el 2% (1/49 fue positivo a BVDV. Estos resultados sugieren circulación viral en la población analizada. Es necesario el monitoreo continuo en las poblaciones de estos rumiantes para identificar factores de riesgo involucrados en la epidemiología de estos agentes virales, considerando los potenciales efectos sobre los programas de control y erradicación.Llama (Lama glama is the predominant species of South American camelids in Argentine Republic, with an estimated population of 200.000 animals. The increasing of productive activity raised the animals transport and distribution to different regions of the country. As a result, the direct contact of these species with cattle increase opportunities for spreading own and common infectious agents among species. Considering that American camelids are susceptible to pestivirus and herpesvirus infections, it was proposed to carry out a serological searching of neutralizing antibodies to bovine viral diarrhea (BVDV and bovine

  11. Complete Genome Sequence of Bradyrhizobium sp. Strain CCGE-LA001, Isolated from Field Nodules of the Enigmatic Wild Bean Phaseolus microcarpus.

    Science.gov (United States)

    Servín-Garcidueñas, Luis E; Rogel, Marco A; Ormeño-Orrillo, Ernesto; Zayas-Del Moral, Alejandra; Sánchez, Federico; Martínez-Romero, Esperanza

    2016-01-01

    We present the complete genome sequence of Bradyrhizobium sp. strain CCGE-LA001, a nitrogen-fixing bacterium isolated from nodules of Phaseolus microcarpus. Strain CCGE-LA001 represents the first sequenced bradyrhizobial strain obtained from a wild Phaseolus sp. Its genome revealed a large and novel symbiotic island. PMID:26988045

  12. InSAR velocity field across the North Anatolian Fault (eastern Turkey): Implications for the loading and release of interseismic strain accumulation

    KAUST Repository

    Cakir, Ziyadin

    2014-10-01

    We use the Persistent Scatterer Interferometric Synthetic Aperture Radar (PS-InSAR) technique with the European Space Agency\\'s Envisat and ERS SAR data acquired on three neighboring descending tracks (T350, T078, and T307) to map the interseismic strain accumulation along a ~225 km long, NW-SE trending section of the North Anatolian Fault that ruptured during the 1939, 1942, and 1943 earthquakes in eastern Turkey. We derive a line-of-sight velocity map of the region with a high spatial resolution and accuracy which, together with the maps of earthquake surface ruptures, shed light on the style of continental deformation and the relationships between the loading and release of interseismic strain along segmented continental strike-slip faults. In contrast with the geometric complexities at the ground surface that appear to control rupture propagation of the 1939 event, modeling of the high-resolution PS-InSAR velocity field reveals a fairly linear and narrow throughgoing shear zone with an overall 20 ± 3 mm/yr slip rate above an unexpectedly shallow 7 ± 2 km locking depth. Such a shallow locking depth may result from the postseismic effects following recent earthquakes or from a simplified model that assumes a uniform degree of locking with depth on the fault. A narrow throughgoing shear zone supports the thick lithosphere model in which continental strike-slip faults are thought to extend as discrete shear zones through the entire crust. Fault segmentation previously reported from coseismic surface ruptures is thus likely inherited from heterogeneities in the upper crust that either preexist and/or develop during coseismic rupture propagation. The geometrical complexities that apparently persist for long periods may guide the dynamic rupture propagation surviving thousands of earthquake cycles.

  13. Synchrotron-radiation x-ray multiple diffraction applied to the study of electric-field-induced strain in an organic nonlinear optical material

    Science.gov (United States)

    Avanci, L. H.; Cardoso, L. P.; Sasaki, J. M.; Girdwood, S. E.; Roberts, K. J.; Pugh, D.; Sherwood, J. N.

    2000-03-01

    In this work, distortions produced in the unit cell of a MBANP [(-)-2-(α-methylbenzylamino)-5-nitropyridine] nonlinear organic crystal under the influence of an applied electric field, E-->, are investigated by using synchrotron-radiation x-ray multiple diffraction (XRMD). The method is based in the inherent sensitivity of this technique to determine small changes in the crystal lattice, which provide peak position changes in the XRMD pattern (Renninger scan). A typical Renninger scan shows numerous secondary peaks, each one carrying information on one particular direction within the crystal. The (hkl) peak position in the pattern, for a fixed wavelength, is basically a function of the unit cell lattice parameters. Thus small changes in any parameter due to a strain produced by E--> give rise to a corresponding variation in the (hkl) peak position and the observed strain is related to the piezoelectric coefficients. The advantage of this method is the possibility of determining more than one piezoelectric coefficient from a single Renninger scan measurement [L. H. Avanci, L. P. Cardoso, S. E. Girdwood, D. Pugh, J. N. Sherwood, and K. J. Roberts, Phys. Rev. Lett. 81, 5426 (1998)]. The method has been applied to the MBANP (monoclinic, point group 2) crystal and we were able to determine four piezoelectric coefficients: \\|d21\\|=0.2(1)×10-11 CN-1, \\|d22\\|=24.8(3)×10-11 CN-1, \\|d23\\|=1.3(1)×10-11 CN-1, and \\|d25\\|=5.9(1)×10-11 CN-1. The measurements were carried out using the SRS stations 16.3, Daresbury Laboratory, Warrington, UK.

  14. Differential sensitivity of five cyanobacterial strains to ammonium toxicity and its inhibitory mechanism on the photosynthesis of rice-field cyanobacterium Ge-Xian-Mi (Nostoc)

    International Nuclear Information System (INIS)

    Effects of two fertilizers, NH4Cl and KCl, on the growth of the edible cyanobacterium Ge-Xian-Mi (Nostoc) and four other cyanobacterial strains were compared at pH 8.3 ± 0.2 and 25 deg. C. Their growth was decreased by at least 65% at 10 mmol L-1 NH4Cl but no inhibitory effect was observed at the same level of KCl. Meanwhile, the strains exhibited a great variation of sensitivity to NH4+ toxicity in the order: Ge-Xian-Mi > Anabaena azotica FACHB 118 > Microcystis aeruginosa FACHB 905 > M. aeruginosa FACHB 315 > Synechococcus FACHB 805. The 96-h EC50 value for relative growth rate with regard to NH4+ for Ge-Xian-Mi was 1.105 mmol L-1, which was much less than the NH4+ concentration in many agricultural soils (2-20 mmol L-1). This indicated that the use of ammonium as nitrogen fertilizer was responsible for the reduced resource of Ge-Xian-Mi in the paddy field. After 96 h exposure to 1 mmol L-1 NH4Cl, the photosynthetic rate, Fv/Fm value, saturating irradiance for photosynthesis and PSII activity of Ge-Xian-Mi colonies were remarkably decreased. The chlorophyll synthesis of Ge-Xian-Mi was more sensitive to NH4+ toxicity than phycobiliproteins. Thus, the functional absorption cross section of Ge-Xian-Mi PSII was increased markedly at NH4Cl levels ≥1 mmol L-1 and the electron transport on the acceptor side of PSII was significantly accelerated by NH4Cl addition ≥3 mmol L-1. Dark respiration of Ge-Xian-Mi was significantly increased by 246% and 384% at 5 and 10 mmol L-1 NH4Cl, respectively. The rapid fluorescence rise kinetics indicated that the oxygen-evolving complex of PSII was the inhibitory site of NH4+

  15. Recent crustal deformation of İzmir, Western Anatolia and surrounding regions as deduced from repeated GPS measurements and strain field

    Science.gov (United States)

    Aktuğ, Bahadır; Kılıçoğlu, Ali

    2006-07-01

    To investigate contemporary neotectonic deformation in İzmir, Western Anatolia and in its neighborhood, a relatively dense Global Positioning System (GPS) monitoring network was established in 2001. Combination of three spatially dense GPS campaigns in 2001, 2003 and 2004 with temporally dense campaigns between 1992 and 2004 resulted in a combined velocity field representing active deformation rate in the region. We computed horizontal and vertical velocity fields with respect to Earth-centered, Earth-fixed ITRF2000, to Eurasia and to Anatolia as well. The rates of principal and shear strains along with rigid-body rotation rates were derived from velocity field. Results show east-west shortening between Karaburun Peninsula and northern part of İzmir Bay together with the extension of İzmir Bay in accordance with general extension regime of Western Anatolia and Eastern Agea. East-west shortening and north-south extension of Karaburun Peninsula are closely related to right-lateral faulting and a clockwise rotation. There exists a block in the middle of the peninsula with a differential motion at a rate of 3-5 ± 1 mm/year and 5-6 ± 1 mm/year to the east and south, respectively. As is in Western Anatolia, north-south extension is dominant in almost all parts of the region despite the fact that they exhibit significantly higher rates in the middle of the peninsula. Extensional rates along Tuzla Fault lying nearly perpendicular to İzmir Bay and in its west are maximum in the region with an extension rate of 300-500 ± 80-100 nanostrain/year and confirm its active state. Extensional rates in other parts of the region are at level of 50-150 nanostrain/year as expected in the other parts of Western Anatolia.

  16. Characterization of the photosynthetic conditions and pigment profiles of the colour strains of Hypnea musciformis from field-collected and in vitro cultured samples

    Directory of Open Access Journals (Sweden)

    Daniela R. P. Fernandes

    2012-08-01

    Full Text Available Hypnea musciformis (Wulfen JV Lamour. is a species of great economic interest as it produces Κ-carrageenan and has shown biological activities against HIV and HSV viruses. This species displays different colour strains in its natural habitat, which may have implications for the biotechnological potential of the species. The aim of this study was to characterize the photosynthetic apparatus and pigment profile of three colour strains of H. musciformis (green, brown and red in their natural habitat and in culture. Chlorophyll a fluorescence of photosystem II was measured with a pulse-amplitude modulated fluorometer and pigments were quantified by spectrofluorimetry (chlorophyll a and spectrophotometry (phycobiliproteins. In the natural habitat, we detected significant differences between the colour strains for the following photochemical parameters: the green strain had a higher effective quantum yield (ΦPSII than the red strain and a higher maximum relative electron transport rate (rETRmax than the brown and red strains. Saturation irradiances were 1000 µE.m-2.s-1 (green and 500 µE.m-2.s-1 (brown and red. Concerning in vitro culture, the green strain presented the lowest ΦPSII, rETRmax, and α rETR, while the brown strain presented the highest values for these same parameters. The chlorophyll a content of the cultured green strain was the lowest. The phycoerythrin contents of the three colour strains were unchanged by either natural of in vitro conditions: lower in green, intermediate in brown and higher in the red strain, ensuring the chromatic identity of the strains. Our results suggest that the green strain has a better performance when exposed to high irradiance, but a lower efficiency under low irradiance compared to the brown and red strains.

  17. Compressively strained SiGe band-to-band tunneling model calibration based on p-i-n diodes and prospect of strained SiGe tunneling field-effect transistors

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Kuo-Hsing; Meyer, Kristin De [imec, Kapeldreef 75, 3001 Leuven (Belgium); Department of Electrical Engineering, KU Leuven, Leuven (Belgium); Verhulst, Anne S.; Rooyackers, Rita; Douhard, Bastien; Delmotte, Joris; Bender, Hugo; Richard, Olivier; Vandervorst, Wilfried; Simoen, Eddy; Hikavyy, Andriy; Loo, Roger; Arstila, Kai; Collaert, Nadine; Thean, Aaron; Heyns, Marc M. [imec, Kapeldreef 75, 3001 Leuven (Belgium)

    2014-12-07

    Band-to-band tunneling parameters of strained indirect bandgap materials are not well-known, hampering the reliability of performance predictions of tunneling devices based on these materials. The nonlocal band-to-band tunneling model for compressively strained SiGe is calibrated based on a comparison of strained SiGe p-i-n tunneling diode measurements and doping-profile-based diode simulations. Dopant and Ge profiles of the diodes are determined by secondary ion mass spectrometry and capacitance-voltage measurements. Theoretical parameters of the band-to-band tunneling model are calculated based on strain-dependent properties such as bandgap, phonon energy, deformation-potential-based electron-phonon coupling, and hole effective masses of strained SiGe. The latter is determined with a 6-band k·p model. The calibration indicates an underestimation of the theoretical electron-phonon coupling with nearly an order of magnitude. Prospects of compressively strained SiGe tunneling transistors are made by simulations with the calibrated model.

  18. Area balance and strain in an extensional fault system: Strategies for improved oil recovery in fractured chalk, Gilbertown Field, southwestern Alabama -- Year 2. Annual report, March 1997--March 1998

    Energy Technology Data Exchange (ETDEWEB)

    Pashin, J.C.; Raymond, D.E.; Rindsberg, A.K.; Alabi, G.G.; Carroll, R.E.

    1998-09-01

    Gilbertown Field is the oldest oil field in Alabama and has produced oil from fractured chalk of the Cretaceous Selma Group and glauconitic sandstone of the Eutaw Formation. Nearly all of Gilbertown Field is still in primary recovery, although waterflooding has been attempted locally. The objective of this project is to analyze the geologic structure and burial history of Mesozoic and Tertiary strata in Gilbertown Field and adjacent areas in order to suggest ways in which oil recovery can be improved. Indeed, the decline of oil production to marginally economic levels in recent years has made this type of analysis timely and practical. Key technical advancements being sought include understanding the relationship of requisite strain to production in Gilbertown reservoirs, incorporation of synsedimentary growth factors into models of area balance, quantification of the relationship between requisite strain and bed curvature, determination of the timing of hydrocarbon generation, and identification of the avenues and mechanisms of fluid transport.

  19. Evaluation of resistance in a selected field strain of Haemonchus contortus to ivermectin and moxidectin using the Larval Migration on Agar Test

    Directory of Open Access Journals (Sweden)

    Fernanda S. Fortes

    2013-02-01

    Full Text Available Haemonchus contortus is one of the most common and economically significant causes of disease in small ruminants worldwide, and the control programs of parasitic nematodes - including H. contortus - rely mostly on the use of anthelmintic drugs. The consequence of the use of this, as the sole sanitary strategy to avoid parasite infections, was the reduction of the efficacy of all chemotherapeutic products with a heavy selection for resistance. The widespread of anthelmintic resistance and the difficulty of its early diagnosis has been a major concern for the sustainable parasite management on farms. The objective of this research was to determine and compare the ivermectin (IVM and moxidectin (MOX effect in a selected field strain of H. contortus with a known resistance status, using the in vitro larval migration on agar test (LMAT. Third stage larvae of the selected isolate were obtained from faecal cultures of experimentally infected sheep and incubated in eleven increasing diluted concentrations of IVM and MOX (6, 12, 24, 48, 96, 192, 384, 768, 1536, 3072 and 6144µg/mL. The dose-response sigmoidal curves were obtained using the R² value of >0.90 and the lethal concentration (LC50 dose for the tested anthelmintic drugs using a four-parameter logistic model. The LC50 value for MOX was significantly lower than IVM (1.253µg/mL and 91.06µg/mL, identifying the H. contortus isolate as considerably less susceptible to IVM compared to MOX. Furthermore, the LMAT showed a high consistency (p<0.0001 and provided to be a useful diagnostic tool for monitoring the resistance status of IVM and MOX in H. contortus field isolate, as well as it may be used for official routine drug monitoring programs under the Ministry of Agriculture (MAPA guidance.

  20. Microstructure and local strain fields in a high-alloyed austenitic cast steel and a steel-matrix composite material after in situ tensile and cyclic deformation

    Energy Technology Data Exchange (ETDEWEB)

    Weidner, A.; Biermann, H. [Institute of Materials Engineering, Technische Universitaet Bergakademie Freiberg (Germany); Yanina, A.; Guk, S.; Kawalla, R. [Institute of Metal Forming, Technische Universitaet Bergakademie Freiberg (Germany)

    2011-09-15

    The tensile and cyclic deformation behaviour of a new metastable austenitic stainless cast TRIP (TRansformation Induced Plasticity) steel and a composite material consisting of austenitic steel matrix (AISI 304) with 5% MgO partially stabilized ZrO{sub 2} (MgO-PSZ) was studied in-situ in a scanning electron microscope (SEM). In-situ tests in the SEM show the evolution of the microstructure with the strain for uniaxial deformation and the number of cycles during fatigue, respectively. Initially, deformation bands develop. In these bands, the face-centred cubic austenite transforms into the hexagonal {epsilon}-martensite and subsequently to the body-centred cubic {alpha}'- martensite. This evolution was studied by different SEM techniques. Electron backscatter diffraction (EBSD) was applied for phase and orientation identification. The dislocation arrangement was investigated applying the electron channelling contrast imaging (ECCI) technique to different deformation stages. The studies are completed with measurements of local displacement fields using digital image correlation (DIC). (Copyright copyright 2011 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)

  1. Effects of electric-field-induced piezoelectric strain on the electronic transport properties of La{sub 0.9}Ce{sub 0.1}MnO{sub 3} thin films

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, R.K., E-mail: zrk@ustc.edu [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hong Kong (China); Dong, S.N. [Department of Physics and Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026 (China); Wu, Y.Q.; Zhu, Q.X. [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Wang, Y.; Chan, H.L.W. [Department of Applied Physics and Materials Research Center, The Hong Kong Polytechnic University, Hong Kong (China); Li, X.M.; Luo, H.S. [State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 200050 (China); Li, X.G. [Department of Physics and Hefei National Laboratory for Physical Sciences at Microscale, University of Science and Technology of China, Hefei 230026 (China)

    2012-12-15

    The authors constructed multiferroic structures by growing La{sub 0.9}Ce{sub 0.1}MnO{sub 3} (LCEMO) thin films on piezoelectric 0.68Pb(Mg{sub 1/3}Nb{sub 2/3})O{sub 3}-0.32PbTiO{sub 3} (PMN-PT) single-crystal substrates. Due to the efficient elastic coupling at the interface, the electric-field-induced piezoelectric strain in PMN-PT substrates is effectively transferred to LCEMO films and thus, leads to a decrease in the resistance and an increase in the magnetoresistance of the films. Particularly, it was found that the resistance-strain coefficient [({Delta}R/R){sub film}/({Delta}{epsilon}{sub zz}){sub film}] of the LCEMO film was considerably enhanced by the application of magnetic fields, demonstrating strong coupling between the lattice and the spin degrees of freedom. ({Delta}R/R){sub film}/({Delta}{epsilon}{sub zz}){sub film} at 122 K was enhanced by {approx} 28.8% by a magnetic field of 1.2 T. An analysis of the overall results demonstrates that the phase separation is crucial to understand strain-mediated modulation of electronic transport properties of manganite film/PMN-PT multiferroic structures. - Highlights: Black-Right-Pointing-Pointer La{sub 0.9}Ce{sub 0.1}Mn{sub O3} films were epitaxially grown on piezoelectric single crystals. Black-Right-Pointing-Pointer Piezoelectric strain influences the electronic transport properties of films. Black-Right-Pointing-Pointer Magnetic field enhances the piezoelectric strain effect. Black-Right-Pointing-Pointer Phase separation is crucial to understand the piezoelectric strain effect.

  2. 蚌埠市某奶牛场IBRV和BVDV的血清学调查%Serological Investigation on IBRV and BVDV in a Dairy Farm of Bengbu

    Institute of Scientific and Technical Information of China (English)

    钟承; 潘玲; 刘亚

    2012-01-01

    To determining the prevalence of infectious bovine rhinotracheitis(IBR) and bovine viral diarrhea(BVD) in a dairy farm of Bengbu, 94 serum samples were collected from 3 non-immune dairy herds for testing the antibodies against IBRV and BVDV. For IBR, 65 serum samples were positive with a total positive rate 69.15%. For BVD, 83 serum were positive with a total positive rate 88.30%. The results indicated that BVD was prevalent in thc farm of Bengbu and preventative control methods should be taken.%本试验对蚌埠市一家未进行牛传染性鼻气管炎及病毒性腹泻免疫的规模化奶牛场的94份奶牛血清样品,分别使用牛传染性鼻气管炎及病毒性腹泻抗体ELISA试剂盒进行检测,共检出牛传染性鼻气管炎阳性血清65份,阳性检出率为69.15%;病毒性腹泻阳性血清83份,阳性检出率为88.30%。结果表明,该规模化奶牛场存在牛传染性鼻气管炎及病毒性腹泻的感染和接触史,应采取净化措施进行控制。

  3. Differential sensitivity of five cyanobacterial strains to ammonium toxicity and its inhibitory mechanism on the photosynthesis of rice-field cyanobacterium Ge-Xian-Mi (Nostoc)

    Energy Technology Data Exchange (ETDEWEB)

    Dai Guozheng [College of Life Sciences, Central China Normal University, Wuhan 430079, Hubei (China); Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, Hubei (China); Deblois, Charles P. [Department des Sciences Biologiques, TOXEN, Canada Research Chair on Ecotoxicology of Aquatic Microorganisms, Universite du Quebec a Montreal, Succursale Centre-ville, C.P. 8888 Montreal, Quebec H3C 3P8 (Canada); Liu Shuwen [College of Life Sciences, Central China Normal University, Wuhan 430079, Hubei (China); Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, Hubei (China); Juneau, Philippe [Department des Sciences Biologiques, TOXEN, Canada Research Chair on Ecotoxicology of Aquatic Microorganisms, Universite du Quebec a Montreal, Succursale Centre-ville, C.P. 8888 Montreal, Quebec H3C 3P8 (Canada); Qiu Baosheng [College of Life Sciences, Central China Normal University, Wuhan 430079, Hubei (China); Hubei Key Laboratory of Genetic Regulation and Integrative Biology, Central China Normal University, Wuhan 430079, Hubei (China)], E-mail: bsqiu@public.wh.hb.cn

    2008-08-29

    Effects of two fertilizers, NH{sub 4}Cl and KCl, on the growth of the edible cyanobacterium Ge-Xian-Mi (Nostoc) and four other cyanobacterial strains were compared at pH 8.3 {+-} 0.2 and 25 deg. C. Their growth was decreased by at least 65% at 10 mmol L{sup -1} NH{sub 4}Cl but no inhibitory effect was observed at the same level of KCl. Meanwhile, the strains exhibited a great variation of sensitivity to NH{sub 4}{sup +} toxicity in the order: Ge-Xian-Mi > Anabaena azotica FACHB 118 > Microcystis aeruginosa FACHB 905 > M. aeruginosa FACHB 315 > Synechococcus FACHB 805. The 96-h EC{sub 50} value for relative growth rate with regard to NH{sub 4}{sup +} for Ge-Xian-Mi was 1.105 mmol L{sup -1}, which was much less than the NH{sub 4}{sup +} concentration in many agricultural soils (2-20 mmol L{sup -1}). This indicated that the use of ammonium as nitrogen fertilizer was responsible for the reduced resource of Ge-Xian-Mi in the paddy field. After 96 h exposure to 1 mmol L{sup -1} NH{sub 4}Cl, the photosynthetic rate, F{sub v}/F{sub m} value, saturating irradiance for photosynthesis and PSII activity of Ge-Xian-Mi colonies were remarkably decreased. The chlorophyll synthesis of Ge-Xian-Mi was more sensitive to NH{sub 4}{sup +} toxicity than phycobiliproteins. Thus, the functional absorption cross section of Ge-Xian-Mi PSII was increased markedly at NH{sub 4}Cl levels {>=}1 mmol L{sup -1} and the electron transport on the acceptor side of PSII was significantly accelerated by NH{sub 4}Cl addition {>=}3 mmol L{sup -1}. Dark respiration of Ge-Xian-Mi was significantly increased by 246% and 384% at 5 and 10 mmol L{sup -1} NH{sub 4}Cl, respectively. The rapid fluorescence rise kinetics indicated that the oxygen-evolving complex of PSII was the inhibitory site of NH{sub 4}{sup +}.

  4. Spatiotemporal distribution of strain field and hydraulic conductivity at the Phoenix valley basins, constrained using InSAR time series and time-dependent models

    Science.gov (United States)

    Miller, M. M.; Shirzaei, M.

    2015-12-01

    Poroelastic theory suggests that long-term aquifer deformation is linearly proportional to changes in pore pressure. Land subsidence is the surface expression of deformation occurring at depth that is observed with dense, detailed, and high precision interferometric SAR data. In earlier work, Miller & Shirzaei [2015] identified zones of subsidence and uplift across the Phoenix valley caused by pumping and artificial recharge operations. we combined ascending and descending Envisat InSAR datasets to estimate vertical and horizontal displacement time series from 2003-2010. Next, wavelet decomposition was used to extract and compare the elastic components of vertical deformation and hydraulic head data to estimate aquifer storage coefficients. In the following, we present the results from elastic aquifer modeling using a 3D array of triangular dislocations, extending from depth of 0.5 to 3.5 km. We employ a time-dependent modeling scheme to invert the InSAR displacement time series, solving for the spatiotemporal distribution of the aquifer-aquitard compaction. Such models are used to calculate strain and stress fields and forecast the location of extensional cracks and earth fissures, useful for urban planning and management. Later, applying the framework suggested by Burbey [1999], the optimum compaction model is used to estimate the 3D distribution of hydraulic conductivities as a function of time. These estimates are verified using in-situ and laboratory observations and provide unique evidence to investigate the stress-dependence of the hydraulic conductivity and its variations due to pumping, recharge, and injection. The estimates will also be used in groundwater flow models, enhancing water management in the valley and elsewhere. References Burby, T. J. (1999), Effects of horizontal strain in estimating specific storage and compaction in confined and leaky aquifer systems, Hydrogeology Journal, 7(6), 521-532, doi:10.1007/s100400050225. Miller, M. M., and M

  5. The strained state cosmology

    CERN Document Server

    Tartaglia, Angelo

    2015-01-01

    Starting from some relevant facts concerning the behaviour of the universe over large scale and time span, the analogy between the geometric approach of General Relativ- ity and the classical description of an elastic strained material continuum is discussed. Extending the elastic deformation approach to four dimensions it is shown that the accelerated expansion of the universe is recovered. The strain field of space-time repro- duces properties similar to the ones ascribed to the dark energy currently called in to explain the accelerated expansion. The strain field in the primordial universe behaves as radiation, but asymptotically it reproduces the cosmological constant. Subjecting the theory to a number of cosmological tests confirms the soundness of the approach and gives an optimal value for the one parameter of the model, i.e. the bulk modulus of the space-time continuum. Finally various aspects of the Strained State Cosmology (SSC) are discussed and contrasted with some non-linear massive gravity theor...

  6. Role of InxGa1-xAs Layer Composition in Modifying Strain Fields and Carrier Confinement Potentials in a Close-stacked InAs/GaAs Quantum Dot System

    Science.gov (United States)

    Lee, Woong; Yoo, Yo-Han; Shin, Hyunho; Myoung, Jae-Min

    2005-05-01

    Role of the composition of InxGa1-xAs strain-relief layer (SRL) in controlling the strain fields and consequent modification of band structures in a close-stacked multi-layer InAs/GaAs quantum dot (QD) system was investigated within the framework of continuum elasticity and model solid theory. It was predicted that strains in the QDs are significantly relieved in proportion to the In concentration in the InxGa1-xAs SRLs between InAs QD and GaAs cap layer. The relaxation of strains caused substantial shift of the conduction band edge in the QDs mainly by the relief of hydrostatic strain component resulting in narrower bandgap within the QDs with increasing In concentration. It is interpreted that such strain relaxation and subsequent band structure modifications are responsible for the experimentally observed redshift of photo-luminescence (PL) spectra elsewhere. Therefore, together with existing experimental work, it is confirmed that conduction band edges of QD systems can be tailored by the control of the SRL composition allowing more flexibility in bandgap engineering.

  7. An Ultrasonic Strain Gauge

    OpenAIRE

    Kersemans, Mathias; Allaer, Klaas; Degrieck, Joris; Van Den Abeele, Koen; Pyl, Lincy; Zastavnik, Filip; Sol, Hugo; Van Paegem, Wim

    2014-01-01

    A method is introduced for the measurements of strain exploiting the interaction between ultrasound waves and characteristics of the insonified specimen. First, the response of obliquely incident harmonic waves to a deterministic surface roughness is utilized. Analysis of backscattered amplitudes in Bragg diffraction geometry then yields a measure for the in-plane strain field by mapping any shift in angular dependency. Secondly, the analysis of the reflection characteristics of normal incide...

  8. Contribution to the large and stable electric field induced strain for textured Pb(Mg1/3Nb2/3)0.675Ti0.325O3 ceramics

    Science.gov (United States)

    Zeng, Jiangtao; Zhao, Kunyu; Ruan, Wei; Ruan, Xuezheng; Zheng, Liaoying; Li, Guorong

    2016-08-01

    Textured Pb(Mg1/3Nb2/3)0.675Ti0.325O3 (PMN-PT) ceramics were prepared by the templated grain growth method with 3% plate-like BaTiO3 as templates. The degree of grain orientation was about 81% by calculating from the XRD pattern. Temperature dependence of electric field induced strain was measured for both untextured and textured PMN-PT ceramics. The results show that the electric field induced strain for textured PMN-PT ceramics is much larger and more stable than that for untextured PMN-PT ceramics in a wide temperature range. The contribution from the piezoelectric effect and electrostrictive effect to the strain was analyzed, and it was found that textured PMN-PT ceramics exhibited electrostrictive coefficient Q33 as high as 5.19 × 10-2 m4 C-2 and it was comparable to that of PMN-PT single crystals. The electrostrictive effect contributed the main part of the enhancement of electric field induced strain for textured PMN-PT ceramics.

  9. Resolving the velocity and strain fields in the Upper Rhine Graben Area from a Combination of Levelling, GNSS and InSAR

    Science.gov (United States)

    Westerhaus, Malte; Fuhrmann, Thomas; Mayer, Michael; Zippelt, Karl; Heck, Bernhard

    2016-04-01

    The Upper Rhine Graben (URG), located in the tri-national region between Germany, France and Switzerland is the most prominent segment of the European Cenozoic rift system. In recent times, the URG area is characterised by small tectonic movements (less than 1 mm/a) and moderate seismicity up to M=5. Historically, earthquake magnitudes exceeding M=6 have been reported showing that the seismic hazard is quite high. The contemporary tectonic surface deformations are superimposed by displacements caused by anthropogenic activities in various locations in the area, such as coal and potash mining, groundwater usage, oil extraction, geothermal energy and CO2 storage. We use data sets from levelling campaigns, InSAR and permanent GNSS sites to raise an inventory of the current 3D surface displacements and strain rates in the URG with high precision and high spatial resolution. Precise levellings carried out by the surveying authorities of Germany, France and Switzerland since the end of the 19th century have been combined to form a network of levelling lines. A kinematic network adjustment is applied on the levelling data, providing an accurate solution for vertical displacement rates at the levelling benchmarks. InSAR is used to fill gaps in the interior of the levelling loops and to significantly increase the number of points. All the available ERS-1/2 and Envisat scenes from two acquisition geometries covering a period from 1992 to 2000 and 2002 to 2010, resp., are processed according to the Persistent-Scatterer approach. In addition, coordinate time series of 76 permanent sites of the GNSS URG Network are used to support the derivation of the horizontal velocity field of the region. Daily GPS-solutions obtained in differential mode are available since 2004. In a first step, estimates of the surface displacement rates are derived from each technique starting from the raw data. Subsequently, the single-technique deformation estimates are mathematically combined to a 3D

  10. Proteção fetal frente a desafio com o vírus da Diarréia Viral Bovina (BVDV) em ovelhas imunizadas com duas amostras de vírus modificadas experimentalmente

    OpenAIRE

    Brum Mário C.S.; Weiblen Rudi; Flores Eduardo F.; Pituco Edviges M.; Tobias Fernando L.; Winkelmann Evandro R.

    2002-01-01

    Duas amostras do vírus da Diarréia Viral Bovina (BVDV) submetidas a múltiplas passagens em cultivo celular e exposição à radiação ultravioleta (UV) a cada passagem foram avaliadas como candidatos a vírus vacinais. As amostras foram testadas quanto à sua atenuação para bezerros e fetos ovinos, reatividade antigênica contra isolados de campo, e capacidade de induzir proteção fetal em ovelhas prenhes. Inoculação intramuscular (IM) dos vírus modificados em quatro bezerros produziu apenas uma elev...

  11. Electric-field-controlled interface strain coupling and non-volatile resistance switching of La1-xBaxMnO3 thin films epitaxially grown on relaxor-based ferroelectric single crystals

    Science.gov (United States)

    Zheng, Ming; Zhu, Qiu-Xiang; Li, Xue-Yan; Yang, Ming-Min; Wang, Yu; Li, Xiao-Min; Shi, Xun; Luo, Hao-Su; Zheng, Ren-Kui

    2014-09-01

    We have fabricated magnetoelectric heterostructures by growing ferromagnetic La1-xBaxMnO3 (x = 0.2, 0.4) thin films on (001)-, (110)-, and (111)-oriented 0.31Pb(In1/2Nb1/2)O3-0.35Pb(Mg1/3Nb1/2)O3-0.34PbTiO3 (PINT) ferroelectric single-crystal substrates. Upon poling along the [001], [110], or [111] crystal direction, the electric-field-induced non-180° domain switching gives rise to a decrease in the resistance and an enhancement of the metal-to-insulator transition temperature TC of the films. By taking advantage of the 180° ferroelectric domain switching, we identify that such changes in the resistance and TC are caused by domain switching-induced strain but not domain switching-induced accumulation or depletion of charge carriers at the interface. Further, we found that the domain switching-induced strain effects can be efficiently controlled by a magnetic field, mediated by the electronic phase separation. Moreover, we determined the evolution of the strength of the electronic phase separation against temperature and magnetic field by recording the strain-tunability of the resistance [(ΔR/R)strain] under magnetic fields. Additionally, opposing effects of domain switching-induced strain on ferromagnetism above and below 197 K for the La0.8Ba0.2MnO3 film and 150 K for the La0.6Ba0.4MnO3 film, respectively, were observed and explained by the magnetoelastic effect through adjusting the magnetic anisotropy. Finally, using the reversible ferroelastic domain switching of the PINT, we realized non-volatile resistance switching of the films at room temperature, implying potential applications of the magnetoelectric heterostructure in non-volatile memory devices.

  12. Genetic diversity of the S10 RNA segment of field and vaccine strains of bluetongue virus from the P. R. China.

    Science.gov (United States)

    Zhang, Yifang; Du, Xiaogang; Li, Wengui; Li, Jinyao; Liu, Jianping; Zhu, Jianbo; Zhang, Nianzu

    2010-02-01

    Bluetongue virus (BTV) infection of ruminants is endemic throughout tropical and subtropical regions of the world. However, the molecular epidemiology of BTV infection in China has not yet been reported. In this study, the S10 gene segments from 30 BTV isolates, one attenuated BTV strain, one vaccine BTV strain, and one South Africa BTV prototype strain, were sequenced. Phylogenetic analysis of the S10 genes showed that Chinese BTV isolates could be classified into two phyletic subgroups, and the clustering of Chinese BTV viruses was dependent on their geographical origin and the number of generations for which they had been propagated, rather than their host species or year of isolation.

  13. Tuning competition between metallic and insulating phases with strain, light and electric field in thin films of La0.39Pr0.24Ca0.37MnO3

    International Nuclear Information System (INIS)

    The electric field and photo illumination effects in thin films of La0.39Pr0.24Ca0.37MnO3(LPCMO)/SrTiO3 with different thicknesses (15, 40 and 120 nm) have been systematically investigated. X-ray diffraction measurements demonstrate that these grown films are epitaxial and c axis oriented. Due to strain relaxation, these films are in different strain states. It is found that the strain state can greatly change not only the electrical properties but also the responses to external perturbations. The thinner film experiences a larger tensile in-plane strain and has a more robust insulating state. The low-temperature insulating state in the 120 nm sample is readily destroyed by a small electric field or light illumination without a bias voltage. Both the critical light density and the critical electric field used to collapse the insulating state in the 40 nm LPCMO film are much larger than those in the 120 nm sample. It is revealed that the bias electric field and light illumination play complementary roles. Light illumination can reduce the critical bias electric field. The 15 nm sample exhibits a robust insulating state, which cannot be destroyed by a combination of a bias voltage of 200 V (E = 4 × 105 V m−1) and light illumination (λ = 532 nm, P = 2 mW cm−2). Large transient photoconductivity has been observed in the 40 nm sample under low bias voltages and in the 15 nm sample under all bias voltages. The observed transient photoconductivity and persistent photoconductivity are believed to have different origins. (paper)

  14. Plane strain test for metal sheet characterization

    OpenAIRE

    Flores, Paulo; Bonnet, Félix; Habraken, Anne

    2007-01-01

    This article shows the influence of a plane strain test specimen geometry on the measurable strain field and the influence of free edge effects over the stress computation. The experimental strain field distribution is measured over the whole deformable zone of a plane strain test specimen by an optical strain gauge. The chosen material is the DC06 IF steel of 0.8 mm thickness. The stress field is computed for several geometries at different strain levels by a Finite Element (FE) commer...

  15. A study on relation between acoustic emission and characteristic displacement field on the sample with multi en echelon structures - The theoretic and experimental explorations of strain gap

    Institute of Scientific and Technical Information of China (English)

    陈顺云; 许昭永; 杨润海; 赵晋明; 郝锦琦; 王赟赟; 王正荣; 熊秉衡

    2002-01-01

    Based on the phenomena that the deformation gap was observed before the great Tangshang earthquake, this paper discusses the strain gap according to test and theory. The (strain) patterns were recorded photographically by real-time holographic interferometry and shadow optical method of caustics, as soon as the loading process started. In the meantime, the AE (acoustic emission) signals were recorded by a micro crack information storage-analysis system. According to damage theory and location of micro fracture, we have studied the stain gap and gained: a) It is necessary that strain gap appears under the condition of linear elasticity theory, and its situation is relatively stable, corresponding to stress concentration. b) Micro fractures, which appear initially at area of high stress, occur rarely at the strain gap, and their locations are finally in the zone between the stress concentration area and the strain gap, which indicate the clusters or groups. However, the major macro fracture (final rupture) started from the shadow areas, and then grew quickly towards the strain gaps, which resulted in failure of sample.

  16. Role of phonon scattering by elastic strain field in thermoelectric Sr1−xYxTiO3−δ

    KAUST Repository

    Bhattacharya, S.

    2014-06-12

    Perovskite-type SrTiO3-δ ceramics are multifunctional materials with significant potential as n-type thermoelectric (TE) materials. The electronic and thermal transport properties of spark plasma sintered polycrystalline Sr1-xYxTiO3-δ (x=0.05, 0.075, 0.1) ceramics are systematically investigated from (15-800) K. The Sr0.9Y0.1TiO3-δ simultaneously exhibits a large Seebeck coefficient, α>-80μV/K and moderately high electrical resistivity, ρ∼0.8mΩ-cm at a carrier concentration of ∼1021cm-3 at 300K resulting in a high TE power factor defined herein as (α2σT)∼0.84W/m-K at 760K. Despite the similar atomic masses of Sr (87.6g/mol) and Y (88.9g/mol), the lattice thermal conductivity (κL) of Sr1-xY xTiO3-δ is significantly reduced with increased Y-doping, owing to the smaller ionic radii of Y3+ (∼1.23Å, coordination number 12) compared to Sr2+ (∼1.44Å, coordination number 12) ions. In order to understand the thermal conductivity reduction mechanism, the κL in the Sr1-xY xTiO3-δ series are phenomenologically modeled with a modified Callaway\\'s equation from 30-600K. Phonon scattering by elastic strain field due to ionic radii mismatch is found to be the prominent scattering mechanism in reducing κL of these materials. In addition, the effect of Y-doping on the elastic moduli of Sr1-xY xTiO3-δ (x=0, 0.1) is investigated using resonant ultrasound spectroscopy, which exhibits an anomaly in x=0.1 in the temperature range 300-600K. As a result, the phonon mean free path is found to be further reduced in the Sr0.9Y0.1TiO3-δ compared to that of SrTiO3-δ, resulting in a considerably low thermal conductivity κ∼2.7W/m-K at 760K. Finally, we report a thermoelectric figure of merit (ZT)∼0.3 at 760K in the Sr0.9Y 0.1TiO3-δ, the highest ZT value reported in the Y-doped SrTiO3 ceramics thus far. © 2014 AIP Publishing LLC.

  17. Phase transition strain and large magnetic field induced strain in Ni{sub 50.5}Mn{sub 24}Ga{sub 25.5} unidirectionally solidified alloy[75.30.Kz; 75.80.+q; 81.30.Kf; NiMnGa; Unidirectional solidification; Martensitic phase transition; Heusler alloy; Preferential orientation

    Energy Technology Data Exchange (ETDEWEB)

    Liang, T.; Jiang, C.B.; Xu, H.B. E-mail: xuhb@public.bta.net.cn; Liu, Z.H.; Zhang, M.; Cui, Y.T.; Wu, G.H

    2004-01-01

    A large magnetic-field-induced strain (MFIS) of 1150 ppm has been obtained in textured Ni{sub 50.5}Mn{sub 24}Ga{sub 25.5} polycrystal prepared by vertical zone melting unidirectional solidification. X-ray diffraction measurements of the cubic structure reveal that the preferential orientation along the growth direction is (2 2 0). Expansion and shrinkage phenomenon upon the martensitic transition has been observed at 223 K (martensitic transition temperature M{sub s}), indicating the existence of a preferential orientation of martensitic variants to minimize elastic energy. This martensitic transition strain can be enhanced six times, up to 1.5% shrinkage with a bias magnetic field of 1.5 T.

  18. BVDV对后备牛生长发育状况及繁殖性能的影响%Effects of BVDV on Growth and Reproductive Performance in Heifers

    Institute of Scientific and Technical Information of China (English)

    马翀; 黄凯; 张俊杰; 邵晓磊; 马宏磊; 刘善超; 罗杨; 李锡智; 郭刚

    2012-01-01

    牛病毒性腹泻/黏膜病(BVD/MD)是一种严重危害奶牛健康的病毒性传染病,其病原为牛病毒性腹泻病毒(BVDV)。BVDV感染牛后主要表现两种状态,即一过性感染(TI)和持续性感染(PI)。BVD在牛场的流行,可严重影响奶牛的生产性能、繁殖性能及牛群健康状况,对奶牛的影响可表现为流产、胎儿畸形、腹泻和免疫抑制等。怀孕母牛在特定妊娠阶段感染BVDV后,可娩出PI犊牛,部分PI犊牛能像正常犊牛一样生长发育至成年,但其生长发育状况和繁殖性能较同龄健康牛差异十分明显。为评价BVDV对后备牛生长发育及繁殖状况的影响,笔者采用ELISA方法检出北京地区28个规模化奶牛场141头BVDV—PI牛,并与同龄健康牛生长发育及繁殖数据相比较,结果表明,BVDV—PI后备牛各月龄段的体高、体重均低于健康后备牛,其首次输精日龄、配准日龄、耗精量明显高于健康后备牛,而一次情期受胎率显著低于健康后备牛。数据显示,BVDV严重影响后备牛的生长发育及繁殖状况。%Bovine viral diarrhea/mucosal disease is one of the most important viral diseases which severe damage the health of cattle. The pathogen of BVD is bovine viral diarrhea virus, represented the prototype member of the pestivirus genus, family Flaviviridae. The genome is made up of a single molecule of linear positive-sense single-stranded ribonucleic acid (RNA) molecule. BVDV infection has two main types, transient infection (TI) and persistent infection (PI). BVD (bovine viral diarrhoea) virus can cause significant damage to cattle health, fertility and productivity. BVDV can cause abortion, diarrhea, malformations, immunosuppression, and so on. Fetal infections in the special stage of gestation may generate persistent infection calves. Some of the PI calves will grow normal like healthy calves, but the growth and reproductive performance is not

  19. Innate immune responses of calves during transient infection with a noncytopathic strain of bovine viral diarrhea virus

    DEFF Research Database (Denmark)

    Muller-Doblies, D.; Arquint, A.; Schaller, P.;

    2004-01-01

    In this study, six immunocompetent calves were experimentally infected with a noncytopathic strain of bovine viral diarrhea virus (BVDV), and the effects of the viral infection on parameters of the innate immune response of the host were analyzed. Clinical and virological data were compared...... with the temporal activation of the alpha/beta interferon-regulated Mx gene in white blood cells (WBC) and skin as well as the upregulation of the acute-phase serum proteins haptoglobin (Hp) and serum amyloid A (SAA). The viral strain used did provoke transient health impairment, namely, fever and leukopenia...... that were associated with viremia, viral shedding with nasal secretions, and antiviral seroconversion. Complete recovery was observed within 3 weeks. Elevated levels of SAA and Hp were apparent from days 4 to 13 and 8 to 11, respectively. In WBC, the levels of Mx mRNA and Mx protein were elevated from days...

  20. Screening of lipase producing strains in oil field%油污土壤中脂肪酶产生菌的筛选

    Institute of Scientific and Technical Information of China (English)

    袁树先; 赵岩; 郭成; 盖秋竹

    2012-01-01

    In order to obtain lipase-producing strain of the bacteria. Thus obtain high activity strains. By adding olive oil as the sole carbon source for enrichment culture, and then a transparent ring plate screening method to screen out from the soil samples can be formed on bromocresol purple medium yellow transparent circle colonies, and then cultured in Rhodamine B, Based on the live bacteria, as well as to get high hydrolysis ring size flask was re-screening high-living strains, and then measured the enzyme activity probably, there are four strains of lipase by screening bacteria produce higher enzyme activity.%为了获得脂肪酶产生菌的菌种,进而获得高酶活菌株.通过添加橄榄油作为唯一碳源进行富集培养,然后以透明圈平板筛选法从富油土样中筛选出能够在溴甲酚紫培养基上形成黄色透明圈的菌落,再在罗丹明B的培养基上得到高活菌种以及水解圈大小,摇瓶复筛得高活菌株,进而测定酶的活力,经筛选有10株脂肪酶产生菌酶活力较高.

  1. Evaluation of Infectivity, Virulence and Transmission of FDMV Field Strains of Serotypes O and A Isolated In 2010 from Outbreaks in the Republic of Korea.

    Science.gov (United States)

    Pacheco, Juan M; Lee, Kwang-Nyeong; Eschbaumer, Michael; Bishop, Elizabeth A; Hartwig, Ethan J; Pauszek, Steven J; Smoliga, George R; Kim, Su-Mi; Park, Jong-Hyeon; Ko, Young-Joon; Lee, Hyang-Sim; Tark, Dongseob; Cho, In-Soo; Kim, Byounghan; Rodriguez, Luis L; Arzt, Jonathan

    2016-01-01

    Since the early 2000s outbreaks of foot-and-mouth disease (FMD) have been described in several previously FMD-free Asian nations, including the Republic of Korea (South Korea). One outbreak with FMD virus (FDMV) serotype A and two with serotype O occurred in South Korea in 2010/2011. The causative viruses belonged to lineages that had been spreading in South East Asia, far East and East Asia since 2009 and presented a great threat to the countries in that region. Most FMDV strains infect ruminants and pigs, as it happened during the outbreaks of FMDV serotype O in South Korea. Contrastingly, the strain of serotype A affected only ruminants. Based upon these findings, the intention of the work described in the current report was to characterize and compare the infectivity, virulence and transmission of both strains under laboratory conditions in cattle and pigs, by direct inoculation and contact exposure. As expected, FMDV serotype O was highly virulent in both cattle and swine by contact exposure and direct inoculation. Surprisingly, FMDV serotype A was highly virulent in swine, but was less infectious in cattle by contact exposure to infected swine or cattle. Interestingly, similar quantities of aerosolized FMDV RNA were detected during experiments with viruses of serotypes O and A. Specific virus-host interaction of A/SKR/2010 could affect the transmission of this strain to cattle, and this may explain in part the limited spread of the serotype A epizootic. PMID:26735130

  2. An Inactivated Vaccine from a Field Strain of Bovine Herpesvirus-1 (BoHV-1) has High Antigenic Mass and Induces Strong Efficacy in a Rabbit Model

    Institute of Scientific and Technical Information of China (English)

    Julian Ruiz-Sáenz; Jairo Jaime; Victor Vera

    2013-01-01

    Bovine Herpesvirus-1 (BoHV-1) is a DNA virus belonging to the family Herpesviridae,subfamily Alfaherpesvirinae;it is a worldwide pathogen,causing serious economic losses in livestock.In Colombia there have been multiple isolates of BoHV-1 that have been subjected to molecular characterization,classifying most of the country isolates as BoHV-1.1.In the present study we developed and evaluated an ethyleneimine binary inactivated isolate from the native BoHV-1 strain (Córdoba-2) in a rabbit model of vaccination and infection.The vaccine was evaluated in two phases,one of immunogenicity with vaccination and a booster after 21 days,and an evaluation phase of protection against challenge with a highly virulent reference strain.The results demonstrate optimum serum-conversion,with protective neutralizing antibody titers 28 days post vaccination and optimal protection against challenge with the reference strain with decreased clinical signs of infection,protection against the onset of fever and decrease of virus excretion post challenge.In conclusion,our results show the enormous potential that an immunogenic inactivated vaccine has produced from the native BoHV-1.1 strain,which produces a high antigen mass to the vaccine to induce optimal immunity and protection,and it is a strong candidate for evaluation and possible future use in different cattle populations.

  3. Evaluation of Infectivity, Virulence and Transmission of FDMV Field Strains of Serotypes O and A Isolated In 2010 from Outbreaks in the Republic of Korea.

    Directory of Open Access Journals (Sweden)

    Juan M Pacheco

    Full Text Available Since the early 2000s outbreaks of foot-and-mouth disease (FMD have been described in several previously FMD-free Asian nations, including the Republic of Korea (South Korea. One outbreak with FMD virus (FDMV serotype A and two with serotype O occurred in South Korea in 2010/2011. The causative viruses belonged to lineages that had been spreading in South East Asia, far East and East Asia since 2009 and presented a great threat to the countries in that region. Most FMDV strains infect ruminants and pigs, as it happened during the outbreaks of FMDV serotype O in South Korea. Contrastingly, the strain of serotype A affected only ruminants. Based upon these findings, the intention of the work described in the current report was to characterize and compare the infectivity, virulence and transmission of both strains under laboratory conditions in cattle and pigs, by direct inoculation and contact exposure. As expected, FMDV serotype O was highly virulent in both cattle and swine by contact exposure and direct inoculation. Surprisingly, FMDV serotype A was highly virulent in swine, but was less infectious in cattle by contact exposure to infected swine or cattle. Interestingly, similar quantities of aerosolized FMDV RNA were detected during experiments with viruses of serotypes O and A. Specific virus-host interaction of A/SKR/2010 could affect the transmission of this strain to cattle, and this may explain in part the limited spread of the serotype A epizootic.

  4. Toxicity of Pyrethroid and Organophosphorous Insecticides against Two Field Collected Strains of the German Cockroach Blattella Germanica (Blattaria: Blattellidae from Hospitals in Hamadan, Iran

    Directory of Open Access Journals (Sweden)

    Mojtaba Limoee

    2012-12-01

    Full Text Available Background: The German cockroach, Blattella germanica is a major hygienic pest and mechanical vector for path­ogenic agents in hospitals and residential areas. The development of insecticide resistance is a serious problem in controlling of this pest. Toxicity of four commonly used insecticides (permethrin, cypermethrin, malathion and chlorpyrifos against two hospital- collected strains of the German cockroach was investigated.Methods: Topical bioassay methods were carried out for detecting insecticide susceptibility of adult male cock­roaches. For each insecticide, four to six concentrations resulting in >0% and <100% mortality were used. Three to six replicates of 10 cockroaches per concentration were conducted. The differences between LD50 (µg/g values were considered statistically significant only when the 95% confidence intervals did not overlap.Results: Two hospital- collected strains of the German cockroach showed low to moderate levels of resistance to chlorpyrifos, permethrin, malathion and cypermethrin based on resistance ratios compared with susceptible strain.Conclusion: The low level chlorpyrifos resistance suggesting this insecticide may still provide adequate control of these strains. While the obsereved moderate levels of resistance to cypermethrin could imply developing resistance to this compound.

  5. Toxicity of Pyrethroid and Organophosphorous Insecticides against Two Field Collected Strains of the German Cockroach Blattella Germanica (Blattaria: Blattellidae) from Hospitals in Hamadan, Iran

    OpenAIRE

    Mojtaba Limoee; Behroz Davari; Seyad Hassan Moosa-Kazemi

    2012-01-01

    Background: The German cockroach, Blattella germanica is a major hygienic pest and mechanical vector for path­ogenic agents in hospitals and residential areas. The development of insecticide resistance is a serious problem in controlling of this pest. Toxicity of four commonly used insecticides (permethrin, cypermethrin, malathion and chlorpyrifos) against two hospital- collected strains of the German cockroach was investigated.Methods: Topical bioassay methods were carried out for detecting ...

  6. Effect of Trichoderma harzianum biomass and Bradyrhizobium sp. strain NC 92 to control leaf blight disease of bambara groundnut (Vigna subterranea) caused by Rhizoctonia solani in the field

    OpenAIRE

    Mana Kanjanamaneesathian; Paranee Sawangsri; Ashara Pengnoo; Jira Suwanprasert

    2007-01-01

    Four hundred and sixty two strains of Trichoderma spp. were isolated from 23 soil samples in which groundnut (Arachis hypogaea L.) and bambara groundnut (Vigna subterranea L.) had been planted in Songkhla, Phattalung, Nakhon Si Thammarat, Narathiwat and Yala provinces. These fungi were tested against Rhizoctonia solani, a causal agent of leaf blight of bambara groundnut, using dual culture technique on PDA medium. Among 462 isolates tested, 226 isolates had an ability to overgrow R. solani co...

  7. Study on the development of high yielding alcohol resistant strain of Saccharomyces cerevisiae and the Influence of Magnetic field on Saccharomyces cerevisiae Inoculum for the production of Alcohol and Vinegar from apple juice.

    Directory of Open Access Journals (Sweden)

    Rabiul Haque

    2014-12-01

    Full Text Available Natural vinegar is one of the fermented products which has some potentiality with respect to a nutraceutical standpoint. The present study is an optimization of the fermentation conditions for apple juice vinegar production from aple juice wine, this biochemical process being aided by Acetobacter aceti.We have studied on the development of high yielding alcohol resistant strain of Saccharomyces cerevisiae for the production of alcohol. Overflow metabolism is an undesirable characteristic of aerobic cultures of Saccharomyces cerevisiae during biomassdirected processes. It results from elevated apple juice containing sugar consumption rates that cause a high substrate conversion to ethanol and other bi-products, severely affecting cell physiology, bioprocess performance, and biomass yields. Fed-batch culture, where sucrose consumption rates are controlled by the external addition of sugar aiming at its low concentrations in the fermentor, is the classical bioprocessing alternative to prevent sugar fermentation by yeasts. However, fed-batch fermentations present drawbacks that could be overcome by simpler batch cultures at relatively high initial sugar concentrations From the results it is clear that strain T2. which has been exposed to 15% alcohol for 18 hrs is the high yielding strain, as it gives 16% alcohol after distillation. We also find that as the exposure is increased, that is, with increasing exposure to 20% alcohol for 5 hrs, 18 hrs, and 20 hrs, the production of alcohol decreases. Saccharomyces cerevisiae yeast cells strain T2. which has been exposed to 15% alcohol for 18 hrs were exposed to a homogenous static magnetic field of 125 mT for periods of 24, 48 or 72 hours and then used as inoculum for the alcoholic fermentation. The exposure to the magnetic field improved the fermentation process kinetics. Biomass and ethanol yields of fermentations inoculated with treated inoculum were higher than those in the control fermentation, which

  8. Clinical Presentation Resembling Mucosal Disease Associated with 'HoBi'-like Pestivirus in a Field Outbreak.

    Science.gov (United States)

    Weber, M N; Mósena, A C S; Simões, S V D; Almeida, L L; Pessoa, C R M; Budaszewski, R F; Silva, T R; Ridpath, J F; Riet-Correa, F; Driemeier, D; Canal, C W

    2016-02-01

    The genus Pestivirus of the family Flaviviridae consists of four recognized species: Bovine viral diarrhoea virus 1 (BVDV-1), Bovine viral diarrhoea virus 2 (BVDV-2), Classical swine fever virus (CSFV) and Border disease virus (BDV). Recently, atypical pestiviruses ('HoBi'-like pestiviruses) were identified in batches of contaminated foetal calf serum and in naturally infected cattle with and without clinical symptoms. Here, we describe the first report of a mucosal disease-like clinical presentation (MD) associated with a 'HoBi'-like pestivirus occurring in a cattle herd. The outbreak was investigated using immunohistochemistry, antibody detection, viral isolation and RT-PCR. The sequence and phylogenetic analysis of 5'NCR, N(pro) and E2 regions of the RT-PCR positive samples showed that four different 'HoBi'-like strains were circulating in the herd. The main clinical signs and lesions were observed in the respiratory and digestive systems, but skin lesions and corneal opacity were also observed. MD characteristic lesions and a pestivirus with cytopathic biotype were detected in one calf. The present study is the first report of a MD like presentation associated with natural infection with 'HoBi'-like pestivirus. This report describes the clinical signs and provides a pathologic framework of an outbreak associated with at least two different 'HoBi'-like strains. Based on these observations, it appears that these atypical pestiviruses are most likely underdiagnosed in Brazilian cattle. PMID:24735072

  9. Analysis of pulsed-field gel electrophoresis molecular subtyping of Shigella strains in Shenzhen%深圳市志贺菌脉冲场电泳分子分型分析

    Institute of Scientific and Technical Information of China (English)

    兰全学; 扈庆华; 石晓路; 王冰; 林一曼; 程锦泉; 张顺祥

    2008-01-01

    目的 分析深圳市2001-2006年分离志贺菌菌株之间的相关性,初步建立志贺菌的脉冲场电泳(pulsed-field gel electrophoresis,PFGE)分子分型监测网络.方法 55株志贺菌基因组DNA经Xba Ⅰ酶切,通过PFGE获得电泳图谱,利用BioNumerics软件对图谱进行聚类分析.结果 55株志贺菌被分为41种PFGE图谱,聚类分析显示32株细菌谱型属于同一个群,其余菌株谱型差异较大.结论 深圳地区存在遗传紧密相关的志贺菌流行克隆,也存在遗传不相关克隆.PFGE分子分型监测网络的建立,有助于细菌性痢疾的主动监测、暴发调查和传染源追踪.%Objective To analyze the genetic relations of Shigella isolated from Shenzhen in 2001-2006 and develop primary molecular subtyping surveillance network of Shigella. Methods Chromosomal DNAs from 55 isolated in agarose were digested with the restriction enzyme Xba Ⅰ , and then were analyzed by pulsed-field gel electrophoresis. Pulsed-field gel electrophoresis (PFGE) patterns were clustered using BioNumerics software. Results All 41 distinctive PFGE patterns were identified among 55 strains. 32 strains belonged to one cluster. Differences were observed in other strains. Conclusion Both genetic-related clones and non-related clones of Shigella existed in Shenzhen. The development of PFGE molecular subtyping surveillance network would contribute to the active surveillance, outbreak investigation and source tracking for Shigellosis.

  10. Using optical full-field measurement based on digital image correlation to measure strain on a tree subjected to mechanical load

    OpenAIRE

    Sebera, V.; Praus, L.; Tippner, J.; Kunecký, J. (Jiří); Čepela, J.; Wimmer, R.

    2014-01-01

    The goal of this study was to analyze and measure the displacement and strain response behavior of the tree (Juglans regia L.) subjected to a mechanical load. The analysis addresses issues of tree biomechanics that call for a high-quality deformation data measured on trees’ surfaces in a noninvasive way. For these purposes, the 3D digital image correlation (3D-DIC) was proposed and tested against standard extensometers. The measured tree was subjected to a bending by a pulling test to...

  11. Strain Field Quantitative Measurement around GP Zones Formed by an Al-Zn-Mg-Cu Alloy Spray Deposition%喷射沉积Al-Zn-Mg-Cu合金GP区应变场的定量测试

    Institute of Scientific and Technical Information of China (English)

    侯小虎; 白朴存; 赵春旺; 邢永明

    2011-01-01

    In order to quantitatively measure the lattice strain distribution around GP zone. an Al122n2. 4Mg1. 1Cu alloy was prepared by spray deposition. Alloy samples were subsequently processed by hot extrusion, solid solution treatment at 758K for 2 hours and aging at 393K for 20 hours. The structure and strain field of GP zones in the alloy was experimentally investigated based on High Resolution Transmission Electon Microscopy (HRTEM) and geometric phase analysis (GPA).Experimental results show that obvious strain difference around GP zones are generated along different directions; the largest strain (εxx = -0. 092)occures along the habit plane normal direction of GP zones, the minimum value(εyy = -0. 004)occures along the habit plane parallel direction. Above results may explain the difference of hinder dislocation motion around GP zone. The difference of strain distribution along different directions around GP zone results in different strain strengthening effect, which causes the difference of hinder dislocation motion.%为定量测试喷射沉积合金GP区周围的晶格应变的分布,利用喷射成形技术制备了Al12Zn2.4Mg1.1Cu合金.随后对合金进行热挤压、758K固溶2小时和393K时效20小时处理.利用高分辨透射电子显微镜(High Resolution Transmission Electron Microscopy,HRTEM)和几何相位分析(Geometric Phase Analysis,GPA)软件对GP区的结构和应变场进行了测量和分析.结果表明,GP区附近的应变值在各方向差别较大,沿GP区惯习面法线方向的应变最大(εxx=-0.092),与惯习面平行方向上的应变最小(εyy=-0.004).该项结果可解释GP 区附近位错运动的差异:由于应变场在各方向上存在较大差别,产生的应变强化效果不同,导致阻碍位错运动的能力也有所不同.

  12. High-amplitude THz and GHz strain waves, generated by ultrafast screening of piezoelectric fields in InGaN/GaN multiple quantum wells

    DEFF Research Database (Denmark)

    Porte, Henrik; van Capel, P.J.S.; Turchinovich, Dmitry;

    2010-01-01

    Screening of large built-in piezoelectric fields in InGaN/GaN quantum wells leads to high-amplitude acoustic emission. We will compare acoustic emission by quantum wells with different thicknesses with photoluminescence; indicating screening.......Screening of large built-in piezoelectric fields in InGaN/GaN quantum wells leads to high-amplitude acoustic emission. We will compare acoustic emission by quantum wells with different thicknesses with photoluminescence; indicating screening....

  13. Strain and Ferroelectric-Field Effects Co-mediated Magnetism in (011)-CoFe2O4/Pb(Mg1/3Nb2/3)0.7Ti0.3O3 Multiferroic Heterostructures.

    Science.gov (United States)

    Wang, Ping; Jin, Chao; Zheng, Dongxing; Li, Dong; Gong, Junlu; Li, Peng; Bai, Haili

    2016-09-14

    Electric-field mediated magnetism was investigated in CoFe2O4 (CFO, deposited by reactive cosputtering under different oxygen flow rates) films fabricated on (011)-Pb(Mg1/3Nb2/3)0.7Ti0.3O3 (PMN-PT) substrates. Ascribed to the volatile strain effect of PMN-PT, the magnetization of the CFO films decreases along the [01-1] direction whereas it increases along the [100] direction under the electric field, which is attributed to the octahedron distortion in the spinel ferrite. Moreover, a nonvolatile mediation was obtained in the CFO film with low oxygen flow rate (4 sccm), deriving from the ferroelectric-field effect, in which the magnetization is different after removing the positive and negative fields. The cooperation of the two effects produces four different magnetization states in the CFO film with low oxygen flow rate (4 sccm), compared to the only two different states in the CFO film with high oxygen flow rate (10 sccm). It is suggested that the ferroelectric-field effect is related to the oxygen vacancies in CFO films.

  14. Strain engineering of graphene: a review

    Science.gov (United States)

    Si, Chen; Sun, Zhimei; Liu, Feng

    2016-02-01

    Graphene has intrigued the science community by many unique properties not found in conventional materials. In particular, it is the strongest two-dimensional material ever measured, being able to sustain reversible tensile elastic strain larger than 20%, which yields an interesting possibility to tune the properties of graphene by strain and thus opens a new field called ``straintronics''. In this article, the current progress in the strain engineering of graphene is reviewed. We first summarize the strain effects on the electronic structure and Raman spectra of graphene. We then highlight the electron-phonon coupling greatly enhanced by the biaxial strain and the strong pseudomagnetic field induced by the non-uniform strain with specific distribution. Finally, the potential application of strain-engineering in the self-assembly of foreign atoms on the graphene surface is also discussed. Given the short history of graphene straintronics research, the current progress has been notable, and many further advances in this field are expected.

  15. Comparison of molecular and biological characteristics of a modified live porcine reproductive and respiratory syndrome virus (PRRSV) vaccine (ingelvac PRRS MLV), the parent strain of the vaccine (ATCC VR2332), ATCC VR2385, and two recent field isolates of PRRSV.

    Science.gov (United States)

    Opriessnig, T; Halbur, P G; Yoon, K-J; Pogranichniy, R M; Harmon, K M; Evans, R; Key, K F; Pallares, F J; Thomas, P; Meng, X J

    2002-12-01

    The objectives of this study were to compare the molecular and biological characteristics of recent porcine reproductive and respiratory syndrome virus (PRRSV) field isolates to those of a modified live virus (MLV) PRRS vaccine and its parent strain. One hundred seventeen, 4-week-old pigs were randomly assigned to six groups. Group 1 (n = 20) served as sham-inoculated negative controls, group 2 (n = 19) was inoculated with Ingelvac PRRS MLV vaccine, group 3 (n = 20) was inoculated with the parent strain of the vaccine (ATCC VR2332), group 4 (n = 19) was inoculated with vaccine-like PRRSV field isolate 98-38803, group 5 (n = 19) was inoculated with PRRSV field isolate 98-37120, and group 6 (n = 20) was inoculated with known high-virulence PRRSV isolate ATCC VR2385. The levels of severity of gross lung lesions (0 to 100%) among the groups were significantly different at both 10 (P < 0.0001) and 28 days postinoculation (p.i.) (P = 0.002). At 10 days p.i., VR2332 (26.5% +/- 4.64%) and VR2385 (36.4% +/- 6.51%) induced gross lesions of significantly greater severity than 98-38803 (0.0% +/- 0.0%), 98-37120 (0.8% +/- 0.42%), Ingelvac PRRS MLV (0.9% +/- 0.46%), and negative controls (2.3% +/- 1.26%). At 28 days p.i., 98-37120 (17.2% +/- 6.51%) induced gross lesions of significantly greater severity than any of the other viruses. Analyses of the microscopic-interstitial-pneumonia-lesion scores (0 to 6) revealed that VR2332 (2.9 +/- 0.23) and VR2385 (3.1 +/- 0.35) induced significantly more severe lesions at 10 days p.i. At 28 days p.i., VR2385 (2.5 +/- 0.27), VR2332 (2.3 +/- 0.21), 98-38803 (2.6 +/- 0.29), and 98-37120 (3.0 +/- 0.41) induced significantly more severe lesions than Ingelvac PRRS MLV (0.7 +/- 0.17) and controls (0.7 +/- 0.15). The molecular analyses and biological characterizations suggest that the vaccine-like isolate 98-38803 (99.5% amino acid homology based on the ORF5 gene) induces microscopic pneumonia lesions similar in type to, but different in severity

  16. Biochemical analysis of bovine viral diarrhea virus polypeptides and studies of strain variation

    Energy Technology Data Exchange (ETDEWEB)

    Raisch, K.P.

    1989-01-01

    Intracellular viral-specific polypeptides from the National Animal Disease Laboratory (NADL) strain of bovine viral diarrhea virus were studied by biosynthesis labelling, radioimmunoprecipitation (RIP), hypertonic initiation block (HIB) and polyacrylamide gel electrophoresis (PAGE). Eighteen virus-specific proteins were identified; thirteen were glycosylated (gp170, p135, p130, gp118, gp82, p80, gp74, gp63, gp60, p59, gp53, gp50, gp45, gp42, p37, gp32, gp25 and p22). When glycosylation was inhibited by tunicamycin, five {sup 35}S-methionine labelled proteins displayed increased electrophoretic mobility (gp170 to p165, gp74 to p66, gp53 to p45, gp50 to p42 and gp25 to p20) and four could not be identified. Similar shifts in mobility were observed following in vitro deglycosylation with endoglycosidases H and F indicating that the nine glycoproteins contained N-linked simple or high mannose containing moieties. Biosynthetic labelling in the presence of the ionophore, monensin, or in vitro deglycosylation with the endoglycosidase, O-glycanase, had no effect, which is consistent with the absence of O-linked carbohydrates in BVDV-specific proteins. N-linked glycosylation of BVDV proteins is critical for infectivity, because the virus from cells treated with tunicamycin was devoid of infectivity, whereas the virus from monensin-treated cells was fully infective. Partitioning of p130, p59, gp53-50, and p37 into solutions of Triton X-114 tentatively identified these molecules as partially hydrophobic transmembrane proteins. Biosynthesis in the presence of {sup 3}H-myristate and {sup 3}H-palmitate did not result in specifically labelled viral proteins indicating predominantly noncovalent nature of putative interactions of these proteins with membranes. Partial proteolytic peptide mapping revealed similarities among gp170, p130 and p80 and between gp53 and gp50.

  17. Biochemical analysis of bovine viral diarrhea virus polypeptides and studies of strain variation

    International Nuclear Information System (INIS)

    Intracellular viral-specific polypeptides from the National Animal Disease Laboratory (NADL) strain of bovine viral diarrhea virus were studied by biosynthesis labelling, radioimmunoprecipitation (RIP), hypertonic initiation block (HIB) and polyacrylamide gel electrophoresis (PAGE). Eighteen virus-specific proteins were identified; thirteen were glycosylated (gp170, p135, p130, gp118, gp82, p80, gp74, gp63, gp60, p59, gp53, gp50, gp45, gp42, p37, gp32, gp25 and p22). When glycosylation was inhibited by tunicamycin, five 35S-methionine labelled proteins displayed increased electrophoretic mobility (gp170 to p165, gp74 to p66, gp53 to p45, gp50 to p42 and gp25 to p20) and four could not be identified. Similar shifts in mobility were observed following in vitro deglycosylation with endoglycosidases H and F indicating that the nine glycoproteins contained N-linked simple or high mannose containing moieties. Biosynthetic labelling in the presence of the ionophore, monensin, or in vitro deglycosylation with the endoglycosidase, O-glycanase, had no effect, which is consistent with the absence of O-linked carbohydrates in BVDV-specific proteins. N-linked glycosylation of BVDV proteins is critical for infectivity, because the virus from cells treated with tunicamycin was devoid of infectivity, whereas the virus from monensin-treated cells was fully infective. Partitioning of p130, p59, gp53-50, and p37 into solutions of Triton X-114 tentatively identified these molecules as partially hydrophobic transmembrane proteins. Biosynthesis in the presence of 3H-myristate and 3H-palmitate did not result in specifically labelled viral proteins indicating predominantly noncovalent nature of putative interactions of these proteins with membranes. Partial proteolytic peptide mapping revealed similarities among gp170, p130 and p80 and between gp53 and gp50

  18. Magnetostriction strain measurement: heterodyne laser interferometry versus strain gauge technique

    OpenAIRE

    Gorji Ghalamestani, Setareh; Vandevelde, Lieven; J.J. Dirckx, Joris; Melkebeek, Jan

    2013-01-01

    Deformation of the ferromagnetic material, known as magnetostriction, causes vibrations and noise of electrical machines and transformer cores. A setup by using heterodyne laser interferometers has been built to measure the magnetostriction strains as a function of the applied magnetic field. The measurement results on a sample of nonoriented electrical steel are presented in this work. These results are compared with those obtained by using a strain gauge setup. The laser measurements are l...

  19. Application of One-step RT-PCR Used to Detect Bulk Milk in BVDV Eradication Programme%一步法RT—PCR检测大缸奶在BVDV清除计划中的应用

    Institute of Scientific and Technical Information of China (English)

    黄凯; 邵晓磊; 李锡智

    2011-01-01

    本文利用一步法RT—PCR对28个牛场共计50份大缸奶样进行了BVDV核酸检测。在与全群抗原检测结果对比后发现.9个已知存有PI牛的泌乳牛群,其大缸奶核酸检测均为阳性,其余41个已知无PI牛的泌乳牛群.除1个因为存在急性感染牛造成阳性结果外,其余40个均为阴性。由此可见,本方法对与泌乳牛群内是否存在PI牛可以做出准确判断,其检测灵敏度和特异性均为100%,阳性预测结果可信度为0.9(9/10),阴性预测结果可信度为0.98(40/41)。此外.针对50个大缸奶样进行的抗体检测表明,对于已感染牛场,泌乳牛群是否存在PI牛,抗体水平没有明显差异(OD1.12±0.12vsOD1.34±0.23,P〉0.05)。实验室条件下,本试验使用的RT—PCR方法对于阳性乳的最低检出限为50uL/头,因此理论上,最多可从1000份样品中检出阳性乳成分(总体积为50mL)。综上可知,本试验确立的RT—PCR方法灵敏度高、特异性强,可对泌乳牛群是否存在PI牛进行准确预测,相比大缸奶抗体检测更具实际指导意义,联合ELISA—Ag使用时还可大幅度降低泌乳牛群BVDV清除计划的检测成本,因而值得推广使用。%A single step, single-tube reverse transcriptase-polymerase chain reaction (RT-PCR) test was developed to detect the presence of bovine viral diarrhoea virus(BVDV) in somatic cells from bulk milk samples. The test was validated by examining 50 bulk milk samples from 28 herds with result of BVDV elimination programme. Results showed that a total of 9 groups which contained one persistently infected animal were positive on bulk milk samples. Another 41 herds were negative except one herd which was positive because there was one acute infection cow. So the test was proved to be highly specific and sensitivity, which the positive predictive value(PPV) and the negative predictive value

  20. Muscle strain injuries.

    Science.gov (United States)

    Garrett, W E

    1996-01-01

    One of the most common injuries seen in the office of the practicing physician is the muscle strain. Until recently, little data were available on the basic science and clinical application of this basic science for the treatment and prevention of muscle strains. Studies in the last 10 years represent action taken on the direction of investigation into muscle strain injuries from the laboratory and clinical fronts. Findings from the laboratory indicate that certain muscles are susceptible to strain injury (muscles that cross multiple joints or have complex architecture). These muscles have a strain threshold for both passive and active injury. Strain injury is not the result of muscle contraction alone, rather, strains are the result of excessive stretch or stretch while the muscle is being activated. When the muscle tears, the damage is localized very near the muscle-tendon junction. After injury, the muscle is weaker and at risk for further injury. The force output of the muscle returns over the following days as the muscle undertakes a predictable progression toward tissue healing. Current imaging studies have been used clinically to document the site of injury to the muscle-tendon junction. The commonly injured muscles have been described and include the hamstring, the rectus femoris, gastrocnemius, and adductor longus muscles. Injuries inconsistent with involvement of a single muscle-tendon junction proved to be at tendinous origins rather than within the muscle belly. Important information has also been provided regarding injuries with poor prognosis, which are potentially repairable surgically, including injuries to the rectus femoris muscle, the hamstring origin, and the abdominal wall. Data important to the management of common muscle injuries have been published. The risks of reinjury have been documented. The early efficacy and potential for long-term risks of nonsteroidal antiinflammatory agents have been shown. New data can also be applied to the field

  1. Efficacy of Pseudomonas fluorescens strain CL145A spray dried powder for controlling zebra mussels adhering to native unionid mussels within field enclosures

    Science.gov (United States)

    Luoma, James A.; Weber, Kerry L.; Severson, Todd J.; Mayer, Denise A.

    2015-01-01

    The efficacy of a commercially prepared spray dried powder (SDP) formulation of Pseudomonas fluorescens (strain CL145A) was evaluated for removing zebra mussels (Dreissena polymorpha) adhering to a population of unionid mussels in Lake Darling (Alexandria, Minnesota). Two groups of unionid mussels were used in the study. Unionid mussels were collected near the test area, weighed, photographed, individually tagged, and randomly allocated to one of nine test enclosures in equal proportions and then divided into two groups. The first group of unionid mussels (Group 1, n = 5 per test enclosure) were indiscriminately selected from each test enclosure and used to estimate the number of zebra mussels adhering to unionid mussels prior to exposure. The second group of unionid mussels (Group 2, n = 22 per test enclosure) were used to evaluate the efficacy of SDP for removal of adhering zebra mussels. Both Group 1 and Group 2 mussels were used to evaluate the effects of SDP exposure on unionid mussel survival.

  2. Selective Discrimination of Listeria monocytogenes Epidemic Strains by a Mixed-Genome DNA Microarray Compared to Discrimination by Pulsed-Field Gel Electrophoresis, Ribotyping, and Multilocus Sequence Typing

    OpenAIRE

    Borucki, Monica K.; Kim, So Hyun; Call, Douglas R.; Smole, Sandra C.; Pagotto, Franco

    2004-01-01

    Listeria monocytogenes can cause serious illness in humans, and subsequent epidemiological investigation requires molecular characterization to allow the identification of specific isolates. L. monocytogenes is usually characterized by serotyping and is subtyped by using pulsed-field gel electrophoresis (PFGE) or ribotyping. DNA microarrays provide an alternative means to resolve genetic differences among isolates, and unlike PFGE and ribotyping, microarrays can be used to identify specific g...

  3. Exploring Mechanisms of Resistance to Respiratory Inhibitors in Field Strains of Botrytis cinerea, the Causal Agent of Gray Mold ▿ †

    OpenAIRE

    Leroux, Pierre; Gredt, Michel; Leroch, Michaela; Walker, Anne-Sophie

    2010-01-01

    Respiratory inhibitors are among the fungicides most widely used for disease control on crops. Most are strobilurins and carboxamides, inhibiting the cytochrome b of mitochondrial complex III and the succinate dehydrogenase of mitochondrial complex II, respectively. A few years after the approval of these inhibitors for use on grapevines, field isolates of Botrytis cinerea, the causal agent of gray mold, resistant to one or both of these classes of fungicide were recovered in France and Germa...

  4. FIELD TRIAL OF PHOSPHINE FUMIGATION ON HIGH RESISTANT STRAINS OF TRIBOLIUM CASTANEUM(HERBST)IN STORED WHEAT IN HORIZONTAL STORAGE%实仓熏蒸磷化氢高抗性赤拟谷盗的研究

    Institute of Scientific and Technical Information of China (English)

    朱建民; 王殿轩; 孙颖; 宋涛; 刘建岭; 杨堃; 张龙; 唐多; 李兆东

    2011-01-01

    在高大平房仓储藏小麦中采用熏蒸试验比较了磷化氢对抗性倍数分别为1、2.5、64和206倍的赤拟谷盗品系杀虫效果.主要结果为:在施药后第2天磷化氢浓度达到210 mL/m3以上,且在经过210~520 mL/m3上升和520~350 mL/m3的变化情况下,抗性2.5倍的品系在3d内全部死亡,抗性64倍的害虫完全死亡时间为6 d,抗性206倍的成虫则在第9天完全死亡.无抗性的害虫经培养也没有出现子代成虫,抗性品系即时死亡率达96%的样品经后期培养其中出现少量子代成虫,但其繁殖力明显小于未进行熏蒸的同品系害虫.结果表明,密闭性较好的高大平房仓中很小的剂量即可保持较高的磷化氢浓度,也可在较短时间内杀死高抗性赤拟谷盗.%A field fumigation of phosphine was carried out on four strains of Tribolium castaneum (Herbst) with resistant factor (Rf) of 1、2.5、64 and 206 in stored wheat in horizontal storage.The results showed that the full mortality time of the strain with Rf 2.5 was three days, the full mortality time of the strain with Rf 64 was six days, and the full mortality time of the strain with Rf 206 was nine days under the condition that the phosphine concentration reached 210 mL/m3 on the second day after fumigation, then rose to 210 mL/m3 and 520 mL/m3 and changed between 520 mL/m3 and 350 mL/m3.There were no progeny reproduced by the adults of low level resistance strains after fumigation forty days.The resistant strains with 96% sudden mortality rate reproduced a small amount of adults of the offspring after cultivation, but the reproductive ability was remarkably lower than that of the non-fumigated insects of the same strains.The results indicated that higher phosphine concentration could be kept in a high and large flat warehouse by adding a very low dosage of phosphine, and Tribolium castaneum (Herbst) with high resistance could be killed in a short time.

  5. Comparison of Virulence Gene Identification, Ribosomal Spacer PCR, and Pulsed-Field Gel Electrophoresis for Typing of Staphylococcus aureus Strains Isolated from Cases of Subclinical Bovine Mastitis in the United States.

    Science.gov (United States)

    Adkins, Pamela R F; Middleton, John R; Fox, Lawrence K

    2016-07-01

    Staphylococcus aureus is one of the most important pathogens causing contagious mastitis in dairy cattle worldwide. The objectives of this study were to determine if recently described S. aureus genotype B was present among previously characterized isolates from cases of bovine intramammary infection in the United States and to compare pulsed-field gel electrophoresis (PFGE) to the combination of ribosomal spacer PCR (RS-PCR) and virulence gene identification for typing of S. aureus strains. The hypothesis was that isolates that were previously characterized as contagious would be identified as genotype B and that the results of the two strain-typing methods would be comparable. Isolates were selected from a collection of S. aureus isolates from eight dairy farms. Mammary quarter milk somatic cell count (SCC) and N-acetyl-β-d-gluconaminidase (NAGase) activity data were known and used to evaluate strain pathogenicity. RS-PCR was performed with conventional gel electrophoresis, and PCR was used for toxin gene identification. RS-PCR patterns were associated with a specific virulence gene pattern, as previously reported. Five RS-PCR banding patterns were identified. None of the isolates were characterized as genotype B. No association between RS-PCR types and milk SCC was found; however, NAGase activity was significantly higher in milk from mammary glands infected with RS-PCR banding type 1 (RSP type 1) than in milk from those infected with RSP type 2. The discriminatory power values were 1.0 and 0.46 for PFGE and RS-PCR, respectively. These data suggest that genotype B may have a limited geographic distribution and that PFGE is more discriminatory than RS-PCR performed with conventional gel electrophoresis for typing of S. aureus isolates of bovine origin.

  6. Comparison of Virulence Gene Identification, Ribosomal Spacer PCR, and Pulsed-Field Gel Electrophoresis for Typing of Staphylococcus aureus Strains Isolated from Cases of Subclinical Bovine Mastitis in the United States.

    Science.gov (United States)

    Adkins, Pamela R F; Middleton, John R; Fox, Lawrence K

    2016-07-01

    Staphylococcus aureus is one of the most important pathogens causing contagious mastitis in dairy cattle worldwide. The objectives of this study were to determine if recently described S. aureus genotype B was present among previously characterized isolates from cases of bovine intramammary infection in the United States and to compare pulsed-field gel electrophoresis (PFGE) to the combination of ribosomal spacer PCR (RS-PCR) and virulence gene identification for typing of S. aureus strains. The hypothesis was that isolates that were previously characterized as contagious would be identified as genotype B and that the results of the two strain-typing methods would be comparable. Isolates were selected from a collection of S. aureus isolates from eight dairy farms. Mammary quarter milk somatic cell count (SCC) and N-acetyl-β-d-gluconaminidase (NAGase) activity data were known and used to evaluate strain pathogenicity. RS-PCR was performed with conventional gel electrophoresis, and PCR was used for toxin gene identification. RS-PCR patterns were associated with a specific virulence gene pattern, as previously reported. Five RS-PCR banding patterns were identified. None of the isolates were characterized as genotype B. No association between RS-PCR types and milk SCC was found; however, NAGase activity was significantly higher in milk from mammary glands infected with RS-PCR banding type 1 (RSP type 1) than in milk from those infected with RSP type 2. The discriminatory power values were 1.0 and 0.46 for PFGE and RS-PCR, respectively. These data suggest that genotype B may have a limited geographic distribution and that PFGE is more discriminatory than RS-PCR performed with conventional gel electrophoresis for typing of S. aureus isolates of bovine origin. PMID:27194685

  7. 一步法RT-PCR检测血清混合样品在BVDV清除计划中的应用%The Application of the One-Step RT-PCR Method to Detect the Serum Mixed Samples in BVDV Eradication Programme

    Institute of Scientific and Technical Information of China (English)

    黄凯; 邵晓磊; 马翀

    2011-01-01

    Total 58 of BVDV (Bovine Viral diarrhea virus) antigen positive sera were detected by one-step RT-PCR method. The results revealed that the minimum detection limit was 5μL/per sample, and the standard sera value of OD was 0.3. In addition, the mathematical deduction proved that the test cost of BVDV eradication programme was the lowest, when the number of the serum mixed samples were 10 to 30. Compared with only using ELISA-Ag, the testing cost of RT-PCR and ELISA-Ag conjunctive use reduced 70%. In one words, the one-step RT-PCR which was used in our study has high sensitivity and specificity. When taking ELISA-Ag conjunotive use in BVDV eradication programme, the test cost could be reduced greatly, so this method was worth to use.%利用一步法RT-PCR对58份BVDV抗原阳性血清进行检测.试验证明,对OD450=0.3的标准血清,该方法的最低检出限为5μL/头,血清混合检测时至少可将60份OD450>0.3的阳性血清等量混合.此外,RT-PCR与ELISA-Ag联合使用时,数学推导证明当混合样品为10~30个/份时,BVDV清除计划检测成本最低,相比单独使用ELISA-Ag,成本至少下降70%.综上,本试验确立的一步法RT-PCR灵敏度高,特异性好,联合ELISA-Ag使用,可大幅降低BVDV清除计划的检测成本,故值得推广使用.

  8. Strain-Gated Field Effect Transistor of a MoS2-ZnO 2D-1D Hybrid Structure.

    Science.gov (United States)

    Chen, Libo; Xue, Fei; Li, Xiaohui; Huang, Xin; Wang, Longfei; Kou, Jinzong; Wang, Zhong Lin

    2016-01-26

    Two-dimensional (2D) molybdenum disulfide (MoS2) is an exciting material due to its unique electrical, optical, and piezoelectric properties. Owing to an intrinsic band gap of 1.2-1.9 eV, monolayer or a-few-layer MoS2 is used for fabricating field effect transistors (FETs) with high electron mobility and on/off ratio. However, the traditional FETs are controlled by an externally supplied gate voltage, which may not be sensitive enough to directly interface with a mechanical stimulus for applications in electronic skin. Here we report a type of top-pressure/force-gated field effect transistors (PGFETs) based on a hybrid structure of a 2D MoS2 flake and 1D ZnO nanowire (NW) array. Once an external pressure is applied, the piezoelectric polarization charges created at the tips of ZnO NWs grown on MoS2 act as a gate voltage to tune/control the source-drain transport property in MoS2. At a 6.25 MPa applied stimulus on a packaged device, the source-drain current can be tuned for ∼25%, equivalent to the results of applying an extra -5 V back gate voltage. Another type of PGFET with a dielectric layer (Al2O3) sandwiched between MoS2 and ZnO also shows consistent results. A theoretical model is proposed to interpret the received data. This study sets the foundation for applying the 2D material-based FETs in the field of artificial intelligence.

  9. Magneto-strain-driven quantum engine on a graphene flake

    OpenAIRE

    Peña, Francisco J.; Muñoz, Enrique

    2015-01-01

    We propose a novel conceptual design for a graphene-based quantum engine, driven by a superposition of mechanical strain and an external magnetic field. Engineering of strain in a nanoscale graphene flake creates a gauge field with an associated uniform pseudo-magnetic field. The strain-induced pseudo-magnetic field can be combined with a real magnetic field, leading to the emergence of discrete relativistic Landau levels within the single-particle picture. The inter-level distance and hence ...

  10. Calculation of the stress-strain stiffness matrix for given strains in an inelastic material

    Energy Technology Data Exchange (ETDEWEB)

    Friedrich, C.M.

    1978-01-01

    In the implicit method of non-linear analysis of stiffness matrices of finite elements, deflection fields and hence strains are assumed known at one stage of the calculations. A procedure is developed to calculate the stress-strain stiffness matrix from the strains without iteration of the stress components when the material is inelastic.

  11. Finite Fault Analysis and Near Field Dynamic Strains and Rotations due to the 11/05/2011 (Mw5.2) Lorca Earthquake, South-Eastern Spain

    CERN Document Server

    Santoyo, Miguel Angel

    2012-01-01

    The 11/5/2011 Lorca, Spain earthquake (Mw=5.2) and its foreshock produced extensive damage to buildings and infrastructures within the town of Lorca and vicinity. During these earthquakes, evidence of rotational behaviour and permanent deformations in many structures were observed. The closest accelerometric station that recorded the ground motions was located about 6.0 km from the hypocentral zone. To analyze these aspects and study the source properties from the near-field, I obtained by an appropriate double time-integration procedure of accelerograms, the displacement time histories including the static component. Using these data I calculated the foreshock and the mainshock slip distributions by means of a complete waveform kinematic inversion. To study the dynamic deformations, the 3D tensor of displacement gradients at Lorca station was computed by a single station method. This was done assuming the incidence of body waves at the recording location. Using the finite fault inversion results and a first ...

  12. Symbiotic N2-Fixation Estimated by the 15N Tracer Technique and Growth of Pueraria phaseoloides (Roxb.) Benth. Inoculated with Bradyrhizobium Strain in Field Conditions

    Science.gov (United States)

    Sarr, Papa Saliou; Okon, Judith Wase; Begoude, Didier Aime Boyogueno; Araki, Shigeru; Ambang, Zachée; Shibata, Makoto; Funakawa, Shinya

    2016-01-01

    This field experiment was established in Eastern Cameroon to examine the effect of selected rhizobial inoculation on N2-fixation and growth of Pueraria phaseoloides. Treatments consisted of noninoculated and Bradyrhizobium yuanmingense S3-4-inoculated Pueraria with three replications each. Ipomoea batatas as a non-N2-fixing reference was interspersed in each Pueraria plot. All the twelve plots received 2 gN/m2 of 15N ammonium sulfate 10% atom excess. At harvest, dry matter yields and the nitrogen derived from atmospheric N2-fixation (%Ndfa) of inoculated Pueraria were significantly (P crop's biomass and represent a good strategy to improve soil fertility for subsequent cultivation. PMID:26904363

  13. 16S rRNA and omp31 gene based molecular characterization of field strains of B. melitensis from aborted foetus of goats in India.

    Science.gov (United States)

    Singh, Ajay; Gupta, Vivek Kumar; Kumar, Amit; Singh, Vikas Kumar; Nayakwadi, Shivasharanappa

    2013-01-01

    Brucellosis is a reemerging infectious zoonotic disease of worldwide importance. In human, it is mainly caused by Brucella melitensis, a natural pathogen for goats. In India, a large number of goats are reared in semi-intensive to intensive system within the close vicinity of human being. At present, there is no vaccination and control strategy for caprine brucellosis in the country. Thus, to formulate an effective control strategy, the status of etiological agent is essential. To cope up with these, the present study was conducted to isolate and identify the prevalent Brucella species in caprine brucellosis in India. The 30 samples (fetal membrane, fetal stomach content and vaginal swabs) collected throughout India from the aborted fetus of goats revealed the isolation of 05 isolates all belonging to Brucella melitensis biovars 3. All the isolates produced amplification products of 1412 and 720 bp in polymerase chain reaction with genus and species specific 16S rRNA and omp31 gene based primers, respectively. Moreover, the amplification of omp31 gene in all the isolates confirmed the presence of immuno dominant outer membrane protein (31 kDa omp) in all the field isolates of B. melitensis in aborted foetus of goats in India. These findings can support the development of omp31 based specific serodiagnostic test as well as vaccine for the control of caprine brucellosis in India.

  14. 16S rRNA and Omp31 Gene Based Molecular Characterization of Field Strains of B. melitensis from Aborted Foetus of Goats in India

    Directory of Open Access Journals (Sweden)

    Ajay Singh

    2013-01-01

    Full Text Available Brucellosis is a reemerging infectious zoonotic disease of worldwide importance. In human, it is mainly caused by Brucella melitensis, a natural pathogen for goats. In India, a large number of goats are reared in semi-intensive to intensive system within the close vicinity of human being. At present, there is no vaccination and control strategy for caprine brucellosis in the country. Thus, to formulate an effective control strategy, the status of etiological agent is essential. To cope up with these, the present study was conducted to isolate and identify the prevalent Brucella species in caprine brucellosis in India. The 30 samples (fetal membrane, fetal stomach content and vaginal swabs collected throughout India from the aborted fetus of goats revealed the isolation of 05 isolates all belonging to Brucella melitensis biovars 3. All the isolates produced amplification products of 1412 and 720 bp in polymerase chain reaction with genus and species specific 16S rRNA and omp31 gene based primers, respectively. Moreover, the amplification of omp31 gene in all the isolates confirmed the presence of immuno dominant outer membrane protein (31 kDa omp in all the field isolates of B. melitensis in aborted foetus of goats in India. These findings can support the development of omp31 based specific serodiagnostic test as well as vaccine for the control of caprine brucellosis in India.

  15. 牛病毒性腹泻弱毒活疫苗免疫持续期的研究%The Efficacy of the Live Attenuated Bovine Viral Diarrhea Virus SM Vaccine Strain

    Institute of Scientific and Technical Information of China (English)

    张淑琴; 郭利; 王炜; 张亭亭; 吴永旺; 武华

    2012-01-01

    The study was designed to evaluate neutralizing (SN) antibodies against bovine viral diarrhea virus (BVDV) in the calves vaccinated with the live attenuated bovine viral diarrhea virus SM vaccine. A total of 30 healthy calves at weaning were randomly divided into two groups, with 15 calves in vaccinate group and 15 in control group. The attenuated BVDV SM vaccine strain was administrated via intramuscular injection on the neck at a single dose and challenged with a virulent BVDV-JL virus by nasal spray. The blood samples were collected at different time points for monitoring SN antibody titers. The results indicated that the SN antibody titers in the vaccinated calves maintained at a relative high level until 12 month post-vaccination, and the vaccinated calves were effectively protected from the challenge, as detected by the white blood cell count (WBC) and virus shedding. Therefore, the duration of immunity of the vaccine was at lease for 9 months.%为检测牛病毒性腹泻病毒(BVDV)弱毒活疫苗在免疫牛体内抗体产生及其消长规律,评价弱毒疫苗的保护效力,并确定免疫持续期,本试验对免疫试验牛每头颈部肌肉接种BVDV SM株弱毒疫苗104.5TCID50/头,监测血清抗体效价,进行免疫持续期的确定.在疫苗免疫后的6、9和12个月分别抽取5头免疫组和5头对照组牛采用BVDV-JL强毒株进行攻毒试验,每头牛攻毒剂量为6×107.0 TCID50/mL.结果显示疫苗免疫后12个月时血清中和抗体效价仍维持在1∶1048以上,攻毒结果显示3个时间点强毒攻击后,免疫组所有动物白细胞数量都没有下降也没有分离到病毒,而对照组动物白细胞数下降均超过30%,6和9个月动物均分离到病毒,而12个月对照组动物由于年龄大,没有分离到病毒,因此暂定此疫苗的免疫持续期为9个月.

  16. 抗CP型、NCP型牛病毒性腹泻病毒高免卵黄抗体的制备%Preparation of IgY against Cytopathic (CP) and Noncytopathic (NCP) Bovine Viral Diarrhea Virus (BVDV)

    Institute of Scientific and Technical Information of China (English)

    赵玉龙; 吾莫尔; 薄新文; 李岩; 钟发刚; 李娜; 库朝锋

    2009-01-01

    本研究采用致细胞病变(cytopathic,CP)型牛病毒性腹泻病毒(bovine viral diarrhea virus,BVDV)标准毒和非致细胞病变(noncytopathic,NCP)型新疆优势毒株免疫产蛋鸡,用改良PEG法提取卵黄抗体(IgY),并对提取的IgY采用SDS-PAGE检测纯度,间接ELISA检测免疫后每隔7 d的抗体效价,并测定所得抗体对NCP型BVDV的中和效价.结果表明,用该法提取的IgY纯度较高;间接ELISA结果证明,经过4次免疫后,抗CP型BVDV的效价达到1:32000,抗NCP型BVDV的效价达到1:40000,3个月后再次检测,卵黄抗体效价未见明显下降.最后一次免疫14 d的抗体对NCP型BVDV的中和效价达到1×10-3.

  17. 青海牦牛BVDV E0基因的表达与抗原性检测%Prokaryotic expression and detection of antigencity of E0 protein of bovine viral diarrhea virus from yak in China

    Institute of Scientific and Technical Information of China (English)

    王光华; 叶成玉; 蔡其刚; 王戈平; 陆艳; 张芳芳; 马利青; 周继章

    2013-01-01

    将青海牦牛病毒性腹泻病毒(BVDV) QHZK株的E0基因亚克隆人原核表达载体pET-32(α),构建了重组表达载体pET-32 (α)-E0,然后用重组质粒转化Rosetta(DE3)感受态细胞,并利用IPTG诱导蛋白表达.表达的蛋白用His-Band镍柱进行亲合层析纯化,Western-blot鉴定表达蛋白.结果显示,E0基因可在大肠杆菌中获得表达,表达产物的分子质量约为44ku,与预计的蛋白分子质量大小一致.Western-blot分析表明,该蛋白可以与BVDV标准阳性血清产生特异性结合反应,具有良好的抗原性,为BVDV亚单位疫苗的研究奠定了基础.

  18. Geobacteraceae strains and methods

    Energy Technology Data Exchange (ETDEWEB)

    Lovley, Derek R.; Nevin, Kelly P.; Yi, Hana

    2015-07-07

    Embodiments of the present invention provide a method of producing genetically modified strains of electricigenic microbes that are specifically adapted for the production of electrical current in microbial fuel cells, as well as strains produced by such methods and fuel cells using such strains. In preferred embodiments, the present invention provides genetically modified strains of Geobacter sulfurreducens and methods of using such strains.

  19. Isolation, identification of antagonistic rhizobacterial strains obtained from chickpea (cicer arietinum l.) field and their in-vitro evaluation against fungal root pathogens

    International Nuclear Information System (INIS)

    Plant growth promoting rhizobacteria (PGPR), are associated with roots, found in the rhizosphere and can directly or indirectly enhance the plant growth. In this study soil was collected from rhizosphere of chickpea fields of different areas of Rawalpindi division of Pakistan. PGPR were isolated, screened and characterized. Eight isolates of rhizobacteria (RHA, RPG, RFJ, RC, RTR, RT and RK) were isolated from Rawalpindi division and were characterized. The antagonistic activity of these PGPR isolates against root infecting fungi (Fusarium oxysporum and Verticillium spp.,) was done and production of indole acetic acid (IAA), siderophore and P-solubilization was evaluated. The isolates RHA, RPG, RFJ, RC, RRD and RT were found to be positive in producing siderophore, IAA and P-solubilization. Furthermore, most of the isolates showed antifungal activity against Fusarium oxysporum, and Verticillium spp. The rhizobacterial isolates RHA, RPG, RFJ, RC, RRD, RTR, RT and RK were used as bio-inoculants that might be beneficial for chickpea cultivation as the rhizobacterial isolates possessed the plant growth promoting characters i.e. siderophore, IAA production, phosphate solubilization. In in vitro tests, Pseudomonas sp. and Bacillus spp. inhibited the mycelial growth of the fungal root pathogens. The isolates (RHA and RPG) also significantly increased (60-70%) seed germination, shoot length, root length of the chickpea. The incidence of fungi was reduced by the colonization of RHA and RPG which enhanced the seedling vigor index and seed germination. The observations revealed that isolates RHA and RPG is quite effective to reduce the fungal root infection in greenhouse, and also increases seed yields significantly. These rhizobacterial isolates appear to be efficient yield increasing as well as effective biocontrol agent against fungal root pathogen. (author)

  20. Muscle strain (image)

    Science.gov (United States)

    A muscle strain is the stretching or tearing of muscle fibers. A muscle strain can be caused by sports, exercise, a ... something that is too heavy. Symptoms of a muscle strain include pain, tightness, swelling, tenderness, and the ...

  1. Muscle strain treatment

    Science.gov (United States)

    Treatment - muscle strain ... Question: How do you treat a muscle strain ? Answer: Rest the strained muscle and apply ice for the first few days after the injury. Anti-inflammatory medicines or acetaminophen ( ...

  2. Aggregation and distribution of strains in microparasites.

    OpenAIRE

    Lord, C. C.; Barnard, B.; Day, K; Hargrove, J. W.; McNamara, J J; Paul, R E; Trenholme, K; Woolhouse, M. E.

    1999-01-01

    Recent research has shown that many parasite populations are made up of a number of epidemiologically distinct strains or genotypes. The implications of strain structure or genetic diversity for parasite population dynamics are still uncertain, partly because there is no coherent framework for the interpretation of field data. Here, we present an analysis of four published data sets for vector-borne microparasite infections where strains or genotypes have been distinguished: serotypes of Afri...

  3. Application and Field Welding Technology of Large Strain Steel Pipe in Pipeline Construction%大应变钢管在管道建设中的应用及现场焊接技术

    Institute of Scientific and Technical Information of China (English)

    隋永莉

    2013-01-01

    In this article,it introduced the related technical requirements of large strain steel pipe application,discussed and analyzed the technical characteristics and difficulties confronted in field welding.Aimed at some problems,such as insufficient strength of welding material,near weld zone of circumferential welded joint softening,difficultly realize high strength match for welded joint,it put forward increasing the width and reinforcement of cap weld in circumferential weld welding.That is to adopting reinforce method to make the whole strength of welded joint is higher than that of base metal,strictly control the upper limit value of tensile strength,reduce softening degree and softening width of welding,in order to realize high strength match of circumferential weld.The large strain steel pipe is with sufficient strength and deformability,its demand to overall performance of circumferential welded joint is higher.In practical application,it should comprehensively consider steel pipe,welding material,welding process and other factors,only to ensure safety application of large strain steel pipe in pipeline construction.%介绍了大应变钢管应用的相关技术要求,探讨分析了大应变钢管现场焊接的技术特点和面临的难题,针对焊接材料强度不足及环焊接头近缝区软化,难以实现焊接接头高强匹配的问题,提出在环焊缝焊接时,增加盖面焊缝的宽度和余高,即采用补强的方法使得环焊接头的整体强度高于母材,并在制造过程中严格控制抗拉强度上限值,降低焊接软化程度和软化宽度,以实现环焊缝的高强匹配的.大应变钢管具有足够的强度和变形能力,对环焊接头的综合性能要求更高,实际应用中应综合考虑钢管、焊材和焊接工艺等各方面因素,才能保证大应变钢管在管道建设中安全应用.

  4. Characterization of the time-dependent strain field at seismogenic depths using first-motion focal mechanisms: Observations of large-scale decadal variations in stress along the San Andrea fault system

    Science.gov (United States)

    Sipkin, S.A.; Silver, P.G.

    2003-01-01

    We present a method for summing moment tensors derived from first-motion focal mechanisms to study temporal dependence in features of the subsurface regional strain field. Time-dependent processes are inferred by comparing mechanisms summed over differing time periods. We apply this methodology to seismogenic zones in central and southern California using focal mechanisms produced by the Northern and Southern California Seismograph Networks for events during 1980-1999. We find a consistent pattern in both the style of deformation (strike-slip versus compressional) and seismicity rate across the entire region. If these temporal variations are causally related, it suggests a temporal change in the regional-scale stress field. One change consistent with the observations is a rotation in the regional maximum horizontal compressive stress direction, followed by a reversal to the original direction. Depending upon the dominant style of deformation locally, this change in orientation of the regional stress will tend to either enhance or hinder deformation. The mode of enhanced deformation can range from increased microseismicity and creep to major earthquakes. We hypothesize that these temporal changes in the regional stress field are the result of subtle changes in apparent relative plate motion between the Pacific and North American plates, perhaps due to long-range postseismic stress diffusion. Others have hypothesized that small changes in plate motion over thousands of years, and/or over decades, are responsible for changes in the style of deformation in southern California. We propose that such changes, over the course of just a few years, also affect the style of deformation.

  5. A Wireless Strain Sensor Network for Structural Health Monitoring

    OpenAIRE

    Chengyin Liu; Jun Teng; Ning Wu

    2015-01-01

    Structural strain under external environmental loads is one of the main monitoring parameters in structural health monitoring or dynamic tests. This paper presents a wireless strain sensor network (WSSN) design for monitoring structural dynamic strain field. A precision strain sensor board is developed and integrated with the IRIS mote hardware/software platform for multichannel strain gauge signal conditioning and wireless monitoring. Measurement results confirm the sensor’s functionality re...

  6. 界面残余应变场的会聚束电子衍射测定%Residual strain fields determined at composite interface using convergent beam electron diffraction

    Institute of Scientific and Technical Information of China (English)

    邹化民; 王仁卉

    2002-01-01

    The residual strain fields at composites interface were studied with two convergent beam electron diffraction (CBED) techniques. One technique is conventional in focus CBED, in which the residual strains were determined by using optimization algorithms to fit the calculated higher order Laue zone (HOLZ) linepatterns with experimental ones. A method for optimization of the adjustable parameters was proposed. Another technique is defocus large angle CBED (LACBED), inwhich the diffraction lines near the interface became shifted, split and twisted, because near the interface the lattice plane spacings are changed and planes are rotated and bent due to residual stresses and surface relaxation. Local lattice plane rotations due to surface relaxation are also dependent on the eigenstrain. By fitting the experimental LACBED pattern with the pattern calculated using dynamical theory, the eigenstrain was determined. These techniques were applie to maesure interfacial fields in particle reinforced composie AI2O3/AI and whisker reinface ;metal matrix (K2O.6TiO2)w/AI%用两种会聚束电子衍射(CBED)技术研究了复合材料界面残余应变场.常规正焦CBED方法中,用优化算法使计算的高阶Laue带(HOLZ)线图与实验图达到最佳拟合,进而确定残余应变.给出了一种减少优化计算中可调参数数目的方法.残余应变与表面弛豫引起的界面附近点阵平面面间距的变化、点阵平面的旋转与弯曲使得离焦的大角度会聚束电子衍射(LACBED)图中的衍射线移位、分裂与弯曲.表面弛豫引起的点阵平面的旋转也决定于本征应变.通过使动力学理论计算的LACBED图与实验图达最佳拟合,可以确定本征应变.用该方法研究了颗粒增强复合材料Al2O3/Al与晶须增强复合材料 (K2O@6TiO2) w/Al的界面残余应变场.

  7. Isolation and Identification of Bovine Viral Diarrhea Virus Shandong Strain%牛病毒性腹泻病毒山东株的分离与鉴定

    Institute of Scientific and Technical Information of China (English)

    侯佩莉; 杨宏军; 宋玲玲; 王洪梅; 刘来兴; 何洪彬

    2013-01-01

    牛病毒性腹泻病毒是牛病毒性腹泻-黏膜病的重要病原体,该病毒病是极为复杂、呈多临床类型表现的传染病,给世界养牛业造成了巨大的经济损失.本研究从疑似牛病毒性腹泻-黏膜病的粪便中分离得到一株病毒能使MDBK细胞产生细胞病变,经RT-PCR检测及扩增产物测序进一步证实,该病毒为牛病毒性腹泻-黏膜病病毒,TCID50测定该病毒的滴度为107.15TCID50/ml.该病毒株的分离鉴定为牛病毒性腹泻病毒疫苗的研制奠定了基础.%Bovine viral diarrhea virus ( BVDV) is the causative agent of bovine viral diarrhoea, and is u-biquitous in cattle. It is very complex and presents a wide range of clinical manifestations, which causes large economic loss to cattle industry around the world. In this study, a virus strain causing cytopathic effect of ma-din -darby bovinekidney (MDBK) was isolated from the bovine excrement and identified as BVDV by RT -PCR and sequencing analysis. The virus titer was 10 7.15 TCID50/ml. The isolation and identification of this virus strain laid foundation for exploring its vaccine.

  8. Comparison of Recognized Pestivirus Species with Two New Putative Species Represented by the Strains Pronghorn and Bungowannah

    Science.gov (United States)

    Aim: Currently four species of pestiviruses are recognized by the International Committee on Viral Taxonomy (ICTV). They are bovine viral diarrhea virus genotype 1 (BVDV1), bovine viral diarrhea virus genotype 2 (BVDV2), border disease virus (BDV) and classical swine fever virus (CSFV). A tentati...

  9. Phase-field-crystal simulation of edge dislo cation climbing and gliding under shear strain%剪切应变下刃型位错的滑移机理的晶体相场模拟∗

    Institute of Scientific and Technical Information of China (English)

    高英俊; 全四龙; 邓芊芊; 罗志荣; 黄创高; 林葵

    2015-01-01

    针对刃型位错的滑移运动,构建包含外力场与晶格原子密度耦合作用的体系自由能密度函数,建立剪切应变作用体系的晶体相场模型。模拟了双相双晶体系的位错攀移和滑移运动,计算了位错滑移的Peierls势垒和滑移速度。结果表明:施加较大的剪切应变率作用,体系能量变化为单调光滑曲线,位错以恒定速度做连续运动,具有刚性运动特征;剪切应变率较小时,体系能量变化出现周期波动特征,位错运动是处于低速不连续运动状态,运动出现周期“颠簸”式滑移运动,具有黏滞运动特征;位错启动运动,存在临界的势垒。位错启动攀移运动的Peierls势垒要比启动滑移Peierls势垒大几倍。位错攀移和滑移运动特征与实验结果相符合。%Structural kinetics in crystalline solids is driven heterogeneously at an atomic level by localized defects, which in turn drive mesoscopic and macroscopic phenomena such as structural phase transformation, fracture, and other forms of plastic flows. A complete description of such processes therefore requires a multiscale approach. Existing modeling methods typically operate exclusively either on an atomic scale or on a mesoscopic scale and macroscopic scale. Phase-field-crystal model, on the other hand, provides a framework that combines atomic length scale and mesoacpoic/diffusive time scale, with the potential reaching a mesoacpoic length through systemic multiscale expansion method. In order to study the dislocation movement under shear strain, the free energy density functional including the exerting shear force term is constructed and also the phase field crystal model for system of shear stain is established. The climb and glide of single dislocation in two-grain system are simulated, and the glide velocity of dislocation and the Peierls potential for dislocation gliding are calculated. The results show that the energy curve changing

  10. Development of an antigen-capture ELISA for detecting bovine viral diarrhea virus%牛病毒性腹泻病毒(BVDV)抗原捕获ELISA检测方法的建立

    Institute of Scientific and Technical Information of China (English)

    张丽颖; 刘畅; 鲍永华; 赵志辉

    2009-01-01

    用牛病毒性腹泻病毒(BVDV)单克隆抗体包被酶标板,以兔多克隆抗体作为夹心抗体,建立BVDV抗原捕获ELISA(AC-ELISA)检测方法,优化反应条件并对该方法的稳定性等指标进行了测试和评价.结果表明,单抗最佳包被质量浓度为5μg/mL,兔多抗血清最佳质量浓度为10μg/mL;单抗在4℃包被12~24 h,多抗在37℃作用1 h为双抗体的最佳反应条件;酶标抗体最适稀释度1∶10000,最适作用时间为1 h;采用1%BSA和1%明胶分别在抗体包被后和加入待检抗原反应后进行两次封闭效果好.用AC-ELISA方法检测临床采集的11份牛腹泻病料和12份健康牛组织样品,同时以病毒分离和RT-PCR检测方法做对比,3种方法符合率很高.研究表明AC-ELISA方法稳定性好,可用于BVDV的临床快速检测.

  11. Polymorphic Amplified Typing Sequences and Pulsed-Field Gel Electrophoresis Yield Comparable Results in the Strain Typing of a Diverse Set of Bovine Escherichia coli O157:H7 Isolates

    Directory of Open Access Journals (Sweden)

    Indira T. Kudva

    2012-01-01

    Full Text Available Polymorphic amplified typing sequences (PATS, a PCR-based Escherichia coli O157:H7 (O157 strain typing system, targets insertions-deletions and single nucleotide polymorphisms at XbaI and AvrII restriction enzyme sites, respectively, and the virulence genes (stx1, stx2, eae, hlyA in the O157 genome. In this study, the ability of PATS to discriminate O157 isolates associated with cattle was evaluated. An in-depth comparison of 25 bovine O157 isolates, from different geographic locations across Northwest United States, showed that about 85% of these isolates shared the same dendogram clade by PATS and pulsed-field gel electrophoresis (PFGE, irrespective of the restriction enzyme sites targeted. The Pearson’s correlation coefficient, r, calculated at about 0.4, 0.3, and 0.4 for XbaI-based, AvrII-based and combined-enzymes PATS and PFGE similarities, respectively, indicating that these profiles shared a good but not high correlation, an expected inference given that the two techniques discriminate differently. Isolates that grouped differently were better matched to their locations using PATS. Overall, PATS discriminated the bovine O157 isolates without interpretive biases or sophisticated analytical software, and effectively complemented while not duplicating PFGE. With its quick turnaround time, PATS has excellent potential as a convenient tool for early epidemiological or food safety investigations, enabling rapid notification/implementation of quarantine measures.

  12. Film germanium strain gauges for cryogenic temperatures

    International Nuclear Information System (INIS)

    Strain-measuring characteristics of strain gauges (SG) based on germanium films on gallium arsenide designed for operation in 4-100 K temperature interval and strain range ε∼(±0.3%) are presented. SG are characterized by weak temperature dependences of resistance and strain sensitivity in the temperature range measured. It is shown that in the low-temperature region SG based on heteroepitaxial germanium films on gallium arsenide are no worse than the best domestic and foreign semiconducting and metal SG and are perspective for cryogenic object diagnostics under magnetic field effect

  13. SEEPAGE FIELD-STRAIN FIELD COUPLING ANALYSIS FOR ROCK MASSES OF COAL SEAM FLOOR DURING MINING ABOVE A CONFINED AQUIFER%煤层底板岩体采动渗流场-应变场耦合分析

    Institute of Scientific and Technical Information of China (English)

    姚多喜; 鲁海峰

    2012-01-01

    根据五沟煤矿1018 工作面地质及水文地质条件,应用三维快速拉格朗日(FLAC3D)流固耦合分析模块,采用变渗透系数方法,对该工作面底板岩体采动渗流应变机制进行数值模拟研究.分析结果表明:采动影响下,围岩渗透系数发生较大的变化,处在采空区正上方的泥岩段最大达到原始渗透系数的1293倍;根据渗流场分析,工作面采动并没有破坏底板隔水层的阻水性能,采动裂隙没有导通灰岩含水层,灰岩水涌入回采工作面形成水害可能性较小;工作面正下方岩体单元安全度小于1的区域最大深度为30 m.综合渗流场以及隔水底板单元安全度分析结果,10煤底板下灰岩水溃入工作面形成水害可能性较小.%Based on the geological and hydrogeological conditions of the face 1018 in Wugou coal mine, the fluid-solid coupling module in FLAC3D with changeable permeability coefficient is adopted to simulate the whole process of damage and failure of rock masses at floor of the coal seam No. 10. The results indicate that the permeability coefficient of surrounding rocks changes a lot due to mining. The maximum permeability coefficient reaches 1 293 times of the original one, which happens at the immediate roof of mined-out area. According to the analysis of seepage field, mining does not destroy water resistance of floor aquifer. Mining fissures do not connect limestone aquifers, and water in the limestone is less likely to flow into stopes to cause damage. The maximum depth of rock masses with element safety degree less than one is about 30 m. According to the change of permeability coefficient of and the analytical results of element safety degree of rock masses, safe mining of the face 1018 can be ensured.

  14. Program Calibrates Strain Gauges

    Science.gov (United States)

    Okazaki, Gary D.

    1991-01-01

    Program dramatically reduces personnel and time requirements for acceptance tests of hardware. Data-acquisition system reads output from Wheatstone full-bridge strain-gauge circuit and calculates strain by use of shunt calibration technique. Program nearly instantaneously tabulates and plots strain data against load-cell outputs. Modified to acquire strain data for other specimens wherever full-bridge strain-gauge circuits used. Written in HP BASIC.

  15. Heterogeneity of inelastic strain during creep of Carrara marble: Microscale strain measurement technique

    Science.gov (United States)

    Quintanilla-Terminel, Alejandra; Evans, Brian

    2016-08-01

    We combined the split cylinder technique with microfabrication technology to observe strain heterogeneities that were produced during high-pressure transient creep of Carrara marble. Samples were patterned with a custom-designed grid of markers spaced 10 µm apart and containing an embedded coordinate system. The microscale strain measurement (MSSM) technique described here allowed us to analyze the local strain distribution with unprecedented detail over large regions. The description of the strain field is a function of the area over which strain is being computed. The scale at which the strain field can be considered homogeneous can provide insight into the deformation processes taking place. At 400-500°C, when twinning production is prolific, we observe highly strained bands that span several grains. One possible cause for the multigrain bands is the need to relieve strain incompatibilities that result when twins impinge on neighboring grains. At 600-700°C, the strain fields are still quite heterogeneous, and local strain varies substantially within grains and near grain boundaries, but the multigrain slip bands are not present. Deformation is concentrated in much smaller areas within grains and along some grain boundaries. The disappearance of the multigrain slip bands occurs when the deformation conditions allow additional slip systems to be activated. At 600°C, when the total strain is varied from 0.11 to 0.36, the spatial scale of the heterogeneity does not vary, but there are increases in the standard deviation of the distribution of local strains normalized by the total strain; thus, we conclude that the microstructure does not achieve a steady state in this strain interval.

  16. Muestreo predial pequeño para predecir una infección activa por virus diarrea viral bovina (VDVB en planteles lecheros de la Xª Región de Chile A small herd sample to predict an active infection with bovine viral diarrhea virus (BVDV in dairy herds of X Region, Chile

    Directory of Open Access Journals (Sweden)

    G. REINHARDT

    2002-01-01

    Full Text Available La diarrea viral bovina está distribuida mundialmente y la mayoría del ganado es seropositivo, aunque la seroprevalencia varía entre predios y grupos de edad. Los animales con infección persistente son los transmisores más eficientes, pasan desapercibidos y son la fuente más importante para la perpetuación de la infección. Este trabajo entrega los resultados del análisis serológico de una muestra predial de 10 animales entre 6 y 12 meses de edad de 44 predios lecheros de la X Región de Chile. Se constató que en 35 planteles (79.5% existiría infección activa con virus diarrea viral bovina, pues al menos 6 de los 10 sueros estudiados presentaron anticuerpos. De esta manera, mediante una muestra pequeña de animales jóvenes es posible predecir, con certeza, la presencia de infección activa en los plantelesBovine viral diarrhea virus (BVDV has a worldwide distribution and most cattle are seropositive, although the prevalence may vary among herds and among different age groups. Persistently infected (PI animals are the most efficient transmitters of infection often remaining unnoticed in the herds thus, becoming the most important source to perpetuate the infection. In each of the 44 dairy herds studied from X Region, Chile, ten young stock aged 6 _ 12 months were tested for antibodies against BVDV. In 35 dairy herds (79.5% BVDV active infection was predicted because at least 6 over ten sera were antibody carriers. Thus, based on few blood samples, herds with PI animals and herds without PI animals could be distinguished with a high degree of accuracy

  17. Afinidades antigênicas de amostras de campo do vírus da bronquite infecciosa das galinhas com a amostra Massachusetts M41 Antigenic affinities of infectious bronchitis virus field isolates to Massachusetts M41 strain

    Directory of Open Access Journals (Sweden)

    M.B. Souza

    2001-04-01

    vaccine strains to unrelated heterologous IBV serotypes. The detection of three M41-related isolates (208-1972, PM1-1987 and PM2-1987 indicate that, despite the high variability and pressure for changes in the S1 protein, M41 clones are still present in the field and may point out that the survival strategies for isolates should include mechanisms that preserve the best fits for cellular receptors.

  18. Pulsed-field gel electrophoresis typing of Escherichia coli strains from samples collected before and after pivmecillinam or placebo treatment of uncomplicated community-acquired urinary tract infection in women

    DEFF Research Database (Denmark)

    Ejrnaes, Karen; Sandvang, Dorthe; Lundgren, Bettina;

    2006-01-01

    ). The finding that the majority of UTIs at follow-up are caused by the primary infecting E. coli strain supports the theory of a vaginal and rectal reservoir but could also support the recent discovery that E. coli strains are able to persist in the bladder epithelium despite appropriate antibiotic treatment...

  19. Development and application of a specific SCAR marker for detection of a released Metarhizium acridum strain M189 in the field%绿僵菌M189菌株特异性SCAR标记的建立及田间监测应用

    Institute of Scientific and Technical Information of China (English)

    苏宇; 农向群; 张泽华

    2012-01-01

    To monitor the effect of a Metarhizium acridum strain spread in the field, a DNA molecular marker to differentiate a released strain from other strains or native isolates was developed. Sixteen arbitrary primers to amplify the genomic DNA of 51 Metarhizium strains were used and 81 polymorphic sites were obtained. Among them, 30 polymorphic bands were obtained from the strain M189. One band ascertained to be specificity to the strain M189 was sequenced and transformed as a specific SCAR (sequence characterized amplified regions) marker for this strain. The marker sensitivity was tested and confirmed by identifying strain M189 from 51examined strains. The SCAR marker was used to distinguish 3 isolates from the soil samples collected from the field and confirmed one of them being the released strain M189.%为了监测生防真菌绿僵菌菌株在田间释放后的回收,有必要建立菌株DNA分子标记,以此将应用的菌株与其他菌株或田间的土著分离株鉴别开来.作者采用16条随机引物扩增了51株绿僵菌菌株的基因组DNA,得到81个多态性位点.其中M189菌株多态性位点30个,分析得到1个特异性位点,并将该位点的DNA片段测序后转化成为特异性SCAR标记.检验确定了该标记的敏感性,可以从供试的51株菌株中准确鉴定出目的菌株M189.并用该标记检测了从田间回收的3个分离株,确定其中1个与应用菌株M189一致.

  20. Growth and (137)Cs uptake and accumulation among 56 Japanese cultivars of Brassica rapa, Brassica juncea and Brassica napus grown in a contaminated field in Fukushima: Effect of inoculation with a Bacillus pumilus strain.

    Science.gov (United States)

    Djedidi, Salem; Kojima, Katsuhiro; Ohkama-Ohtsu, Naoko; Bellingrath-Kimura, Sonoko Dorothea; Yokoyama, Tadashi

    2016-06-01

    Fifty six local Japanese cultivars of Brassica rapa (40 cultivars), Brassica juncea (10 cultivars) and Brassica napus (6 cultivars) were assessed for variability in growth and (137)Cs uptake and accumulation in association with a Bacillus pumilus strain. Field trial was conducted at a contaminated farmland in Nihonmatsu city, in Fukushima prefecture. Inoculation resulted in different responses of the cultivars in terms of growth and radiocesium uptake and accumulation. B. pumilus induced a significant increase in shoot dry weight in 12 cultivars that reached up to 40% in one B. rapa and three B. juncea cultivars. Differences in radiocesium uptake were observed between the cultivars of each Brassica species. Generally, inoculation resulted in a significant increase in (137)Cs uptake in 22 cultivars, while in seven cultivars it was significantly decreased. Regardless of plant cultivar and bacterial inoculation, the transfer of (137)Cs to the plant shoots (TF) varied by a factor of up to 5 and it ranged from to 0.011 to 0.054. Five inoculated cultivars, showed enhanced shoot dry weights and decreased (137)Cs accumulations, among which two B. rapa cultivars named Bitamina and Nozawana had a significantly decreased (137)Cs accumulation in their shoots. Such cultivars could be utilized to minimize the entry of radiocesium into the food chain; however, verifying the consistency of their radiocesium accumulation in other soils is strongly required. Moreover, the variations in growth and radiocesium accumulation, as influenced by Bacillus inoculation, could help selecting well grown inoculated Brassica cultivars with low radiocesium accumulation in their shoots. PMID:26986237