796 resultados para Pocahontas, -1617
Resumo:
We present entire sequences of two hymenopteran mitochondrial genomes and the major portion of three others. We combined these data with nine previously sequenced hymenopteran mitochondrial genomes. This allowed us to infer and analyze the evolution of the 67 mitochondrial gene rearrangements so far found in this order. All of these involve tRNA genes, whereas four also involve larger (protein-coding or ribosomal RNA) genes. We find that the vast majority of mitochondrial gene rearrangements are independently derived. A maximum of four of these rearrangements represent shared, derived organizations, whereas three are convergently derived. The remaining mitochondrial gene rearrangements represent new mitochondrial genome organizations. These data are consistent with the proposal that there are an enormous number of alternative mitochondrial genome organizations possible and that mitochondrial genome organization is, for the most part, selectively neutral. Nevertheless, some mitochondrial genes appear less mobile than others. Genes close to the noncoding region are generally more mobile but only marginally so. Some mitochondrial genes rearrange in a pattern consistent with the duplication/random loss model, but more mitochondrial genes move in a pattern inconsistent with this model. An increased rate of mitochondrial gene rearrangement is not tightly associated with the evolution of parasitism. Although parasitic lineages tend to have more mitochondrial gene rearrangements than nonparasitic lineages, there are exceptions (e.g., Orussus and Schlettererius). It is likely that only a small proportion of the total number of mitochondrial gene rearrangements that have occurred during the evolution of the Hymenoptera have been sampled in the present study.
Resumo:
In strengthening systems, the CFRP (Carbon Fibre Reinforced Polymer) materials typically have excellent resistance against environmental conditions; however, the performance of adhesives between CFRP and steel is generally affected by various environmental conditions such as marine environment, cold and hot weather. This paper presents the comparative durability study of CFRP strengthened tubular steel structures by using two different adhesives such as MBrace saturant and Araldite K630 under four-point bending. The program consisted of testing twelve CFRP strengthened specimens having treated with epoxy based adhesion promoter, untreated surface and one unstrengthened specimen and conditioned under cold weather for 3 and 6 months to determine the environmental durability. The beams were then loaded to failure in quasi-static manner under four-point bending. The structural responses of CFRP strengthened tubular steel beams were compared in terms of failure load, stiffness and modes of failure. The research findings show that the cold weather immersion had adversely affected the durability of CFRP strengthened steel members. Design factor is also proposed to address the short-terms durability performance under cold weather.
Resumo:
Many software applications extend their functionality by dynamically loading libraries into their allocated address space. However, shared libraries are also often of unknown provenance and quality and may contain accidental bugs or, in some cases, deliberately malicious code. Most sandboxing techniques which address these issues require recompilation of the libraries using custom tool chains, require significant modifications to the libraries, do not retain the benefits of single address-space programming, do not completely isolate guest code, or incur substantial performance overheads. In this paper we present LibVM, a sandboxing architecture for isolating libraries within a host application without requiring any modifications to the shared libraries themselves, while still retaining the benefits of a single address space and also introducing a system call inter-positioning layer that allows complete arbitration over a shared library’s functionality. We show how to utilize contemporary hardware virtualization support towards this end with reasonable performance overheads and, in the absence of such hardware support, our model can also be implemented using a software-based mechanism. We ensure that our implementation conforms as closely as possible to existing shared library manipulation functions, minimizing the amount of effort needed to apply such isolation to existing programs. Our experimental results show that it is easy to gain immediate benefits in scenarios where the goal is to guard the host application against unintentional programming errors when using shared libraries, as well as in more complex scenarios, where a shared library is suspected of being actively hostile. In both cases, no changes are required to the shared libraries themselves.
Resumo:
Glasses have been prepared by conventional quenching techniques in the ternary sulphate system KzSO4-Na2SO4-ZnSO4, in the range 30-80 % ZnS04. The proportions of alkali sulphates in the glass have been varied widely. The glass formation region has been delineated and densities, refractive indices and microhardnesses have been measured. The heat capacities of the glasses have been measured over a wide range of temperature by differential scanning calorimetry. The effect of composition on molar volume, molar polarization and glass transition have been explained on the basis of a random close-packing model.
Resumo:
This paper compares classified normalized difference vegetation index images of cotton crops derived from both low and high resolution satellite imagery to determine the most accurate and feasible option for Australian cotton growers. It also demonstrates a rapid automated processing and internet delivery system for distributing satellite SPOT-2 imagery. Also provided is the profile of two case studies conducted in the Darling Towns demonstrating the potential benefit of adopting this technology for improving in-season agronomic crop assessments and therefore enable improved management decisions to be made.
Resumo:
Northern Australia is considered to be one of the last strongholds for three critically endangered sawfishes, Pristis zijsron, Pristis clavata, and Pristis microdon, making these populations of global significance. Population structure and levels of genetic diversity were assessed for each species across northern Australia using a portion of the mitochondrial control region. Statistically significant genetic structure was detected in all three species, although it was higher in P. microdon (F-ST = 0.811; N = 149) than in either P. clavata (F-ST = 0.419; N = 73) or P. zijsron (F-ST = 0.202; N = 49), possibly due to a much higher and/or localized level of female philopatry in P. microdon. The overall levels of haplotype diversity in P. zijsron (h = 0.555), P. clavata (h = 0.489), and P. microdon (h = 0.650) were moderate, although it appears to be reduced in the assemblages of P. zijsron and P. clavata in the Gulf of Carpentaria (h = 0.342 and h = 0.083, respectively). Since female migration (replenishment) between regions is unlikely, conservation plans should strive to maintain current levels of diversity and abundances in the regional assemblages of each species.
Resumo:
The durability of carbon fibre reinforced polymer (CFRP) strengthened steel circular hollow section (CHS) members has now become a real challenge to researchers. In addition, various parameters that may affect the durability of such members have not been revealed yet. This paper presents brief experimental results and the first finite element (FE) approach of CFRP strengthened steel CHS beams conditioned in simulated sea water, along with an accelerated corrosion environment at ambient (24 OC ± 4 OC) and 50 OC temperatures. The beams were loaded to failure under four-point bending. It was found that the strength and stiffness reduced significantly after conditioning in an accelerated corrosion environment. Numerical simulation is implemented using the ABAQUS static general approach. A cohesive element was utilised to model the interface element and an 8-node quadrilateral in-plane general-purpose continuum shell was used to model CFRP elements. A mixed mode cohesive law was deployed for all the three components of stresses in the proposed FE approach, which were one normal component and two shear components. The validity of the FE models was ascertained by comparing the ultimate load and load vs deflection response from experimental results. A range of parametric studies were conducted to investigate the effects of bond length, adhesive types, thickness and diameter of tubes. The results of parametric studies indicated that the adhesive with high tensile modulus performed better and durability design factors varied from section to section.
Resumo:
Demographic changes necessitate that companies commit younger workers and motivate older workers through work design. Age-related differences in occupational goals should be taken into account when accomplishing these challenges. In this study, we investigated goal contents and goal characteristics of employees from different age groups. We surveyed 150 employees working in the service sector (average age = 44 years, age range 19 to 60 years) on their most important occupational goals. Employees who stated goals from the area of organizational citizenship were significantly older than employees with other goals. Employees who stated goals from the areas of training and pay/career were significantly younger than employees with other goals. After controlling for gender, education, and work characteristics, no age-related differences were found in the goal areas teamwork, job security, working time, well-being, and new challenges. In addition, no relationships were found between age and the goal characteristics specificity, planning intensity, as well as positive and negative goal emotions. We recommend that companies provide older workers with more opportunities for organizational citizenship and commit younger workers by providing development opportunities and adequate pay
Resumo:
Systematic relationships between the rusts on Goodeniaceae and Stylidiaceae were examined using phylogenetic analyses with two loci (internal transcribed spacer, large subunit region) from ribosomal DNA. Fresh specimens and herbarium material of four rust species (Puccinia dampierae, P. gilgiana, P. saccardoi and Uromyces scaevolae) from the Goodeniaceae and one (P. stylidii) from the Stylidiaceae were examined. A further species (P. lagenophorae) that is reported from hosts in Goodeniaceae and Asteraceae was included in our analysis. Our phylogenetic analysis recovered the rusts on Goodeniaceae and Stylidiaceae in clades sister to P. lagenophorae on Asteraceae. This supported a taxonomy in which P. lagenophorae is restricted to Asteraceae. Descriptions or taxonomic notes are provided for all of the known rusts on Goodeniaceae and Stylidiaceae.
Resumo:
Hyvinkääläiset työläisnaiset ottivat vuoden 1918 sisällissotaan osaa punakaartin riveissä ruoanlaittajina, sairaanhoitajina sekä asetta kantaneina sotilaina. Valkokaartia tukemaan saapuneet saksalaissotilaat saavuttivat Hyvinkään huhtikuun 20. päivä, ja pitäjä valloitettiin. Osa hyvinkääläisnaisista oli tässä vaiheessa siirtynyt jo pohjoisemmille rintamille. Valkoiset etenivät kuitenkin voittoisasti kohti pohjoista, ja suurin osa hyvinkääläisnaisista oli antautunut 1. toukokuuta mennessä. Tämä tutkimus tarkastelee Hyvinkään punakaartilaisnaisiin kohdistuneita kuulustelututkimuksia ja toimenpiteitä sisällissodan jälkiselvittelyissä, jotka alkoivat huhtikuussa ja jatkuivat vuoden loppuun saakka. Samalla tuon esiin runsaasti uutta tietoa Hyvinkään punakaartilaisnaisten toimista sisällissodassa sekä heidän taustoistaan. Tärkeimpiä lähteitä tutkimuksessani ovat erilaiset Kansallisarkistossa säilytettävät oikeusasiakirjat: Hyvinkään pitäjän kenttäoikeuksien pöytäkirjat, viralliset esitutkintapöytäkirjat sekä valtiorikosoikeuksien ja valtiorikosylioikeuden aktit. Lisäksi olen etsinyt tietoa sodassa ja sen jälkiselvittelyissä surmansa saaneista punaisista hyvinkääläisnaisista. Tässä tärkeimpinä lähteinäni ovat olleet Suomen Sotasurmat 1914–1922 -projektin nimitiedosto sekä valkokaartin kirjanpidosta löytyneet vangitsemistiedot. Olen hyödyntänyt suuren tietomäärän käsittelyssä tilastollisia menetelmiä. Tarkastelen naisia kuitenkin paljon myös yksilötasolla, sillä juuri yksilötarinat rikastuttavat paikallishistoriallista tutkimusta. Tutkimukseni perusteella punaisiksi luokiteltuja hyvinkääläisnaisia menehtyi sisällissodan jälkiselvittelyissä 27 – heistä suurin osa Lahden ja Hämeenlinnan seudulla, missä viimeiset taistelut käytiin. Menehtyneistä naisista moni oli vasta 16–17-vuotias. Myös hyvinkääläisnaisia joutui suurille vankileireille – tässä yhteydessä tarkastelen kahden naisen vankileirimuistelmia. Kotipaikkakunnalla tutkittiin samanaikaisesti kenttäoikeuksissa 64 hyvinkääläisnaista. Kenttäoikeuksien tehtävänä oli kartoittaa punakaartilaisten toimintaa sekä heidän tietojansa paikkakunnalla ja lähiseuduilla tapahtuneista murhista sekä ryöstöistä. Kenttäoikeuksissa kuulustelluista naisista valtaosa vapautettiin lyhyen vankeuden jälkeen. Jälkiselvittelyjen virallisessa vaiheessa 116 hyvinkääläistä punakaartilaisnaista joutui kuulusteluihin. Heistä vajaa puolet oli toiminut sodan aikana erilaisissa huoltotehtävissä mm. punakaartin ruokalassa. 25 naista oli epäiltynä Hyvinkäällä huhtikuussa perustetussa aseellisessa naiskaartissa toimimisesta. Loput olivat toimineet punaisten hallinnossa tai sairaanhoitotehtävissä kotipaikkakunnalla ja rintamilla. Kuulustelujen perusteella 81 naista sai vuoden 1918 jälkipuoliskolla syytteen valtiorikosoikeudessa; heistä suurin osa avunannosta valtiopetokseen. Tutkimukseni kattaa näin kaikkiaan noin 150 hyvinkääläistä punakaartilaisnaista. Tutkimukseni valottaa heidän toimintaansa sodan aikana sekä arvioi rankaisutoimenpiteiden motiiveja. Tutkimukseni mukaan asetta kantaneisiin naisiin suhtauduttiin jälkiselvittelyissä keskimäärin hyvin ankarasti. Muiden punakaartilaisnaisten osalta rankaisutoimenpiteissä ei ollut yhtenäistä linjaa. Perunankuorinta punakaartin ruokalassa saattoi olla tuomittava rikos siinä missä kaartilaisten matkoilla liikkuminen ja ryöstetyn tavaran kätkeminen.
Resumo:
We have previously reported that both Ca2+ and staurosporine-sensitive protein kinase(s) are involved in the cytokinin zeatin induction of cucumber chitinase activity and its protein content (Barwe et al. 2001). To further characterize signal transduction events involved in this cytokinin induction of chitinase gene expression, Northern hybridizations of total RNAs prepared from excised, dark-grown cucumber cotyledons treated with cytokinins and/or various agonists and antagonists of signal transduction components, were carried out using a cucumber acidic chitinase (CACHT) cDNA probe (Metraux et al. 1989). CACHT mRNA increased by approximately 5- to 6-fold in response to exogenous zeatin (Z), zeatin riboside (ZR), and benzyladenine (BA) treatment, but failed to accumulate in response to kinetin (K). Among the cytokinins tested, Z was most effective. The Z-induced accumulation of CACHT mRNA was inhibited by a plasma membrane Ca2+ channel blocker verapamil. Treatment of cotyledons with exogenous CaCl2 and calcium ionophore A23187 in the presence and absence of cytokinin enhanced CACHT mRNA accumulation. These two observations suggest the participation of extracellular calcium in signaling Z-induction. Furthermore, the presence of staurosporine (an inhibitor of protein kinase) in Z treatment reduced CACHT mRNA, suggesting the involvement of phosphorylation of one or more cellular proteins. In addition, we provide evidence that the Z-induction of CACHT mRNA is blocked by protein synthesis inhibitor cycloheximide treatment. Taken together, these results suggest that Ca2+ influx from extracellular space, protein phosphorylation, and concurrent protein synthesis events participate in cytokinin signaling during Z-induced CACHT transcript accumulation.