NASA/USRA high altitude research aircraft. Gryphon: Soar like an eagle with the roar of a lion

At the equator, the ozone layer ranges from 65,000 to 130,000+ feet. This is beyond the capabilities of the ER-2, which is NASA's current high altitude reconnaissance aircraft. The Universities Space Research Association, in cooperation with NASA, is sponsoring an undergraduate program which is geared to designing an aircraft that can study the ozoned layer at the equator. This aircraft must be able to satisfy four mission profiles. Mission one is a polar mission which ranges from Chile to the South Pole and back to Chile, a total range of 6000 n. mi. at 100,000 feet with a 2500 lb. payload. The second mission is also a polar mission with a decreased altitude of 70,000 feet and an increased payload of 4000 lb. For the third mission, the aircraft will take-off at NASA Ames, cruise at 100,000 feet carrying a 2500 lb. payload, and land in Puerto Montt, Chile. The final mission requires the aircraft to take-off at NASA Ames, cruise at 100,000 feet with a 1000 lb. payload, make an excursion to 120,000 feet, and land at Howard AFB, Panama. All three missions require that a subsonic Mach number be maintained due to constraints imposed by the air sampling equipment. The aircraft need not be manned for all four missions. Three aircraft configurations were determined to be the most suitable for meeting the above requirements. The performance of each configuration is analyzed to investigate the feasibility of the project requirements. In the event that a requirement can not be obtained within the given constraints, recommendations for proposal modifications are given

The Effect of Idoxuridine (IDU) on Corneal Stromal Cells in Tissue Culture

Corneal stromal cells were cultured in vitro and exposed to various concentrations of idoxuridine (IDU), ranging from 0 to 1,000 μg of IDU per ml of medium. Inhibition of cell multiplication occurred with concentrations of 0.1 μg per ml. With concentrations of 1.0 μg per ml and greater, there was no increase in cell number from the time of exposure to IDU

Open Infrastructure for Edge : A Distributed Ledger Outlook

High demand for low latency services and local data processing has given rise for edge computing. As opposed to cloud computing, in this new paradigm computational facilities are located close to the end-users and data producers, on the edge of the network, hence the name. The critical issue for the proliferation of edge computing is the availability of local computational resources. Major cloud providers are already addressing the problem by establishing facilities in the proximity of end-users. However, there is an alternative trend, namely, developing open infrastructure as a set of standards, technologies, and practices to enable any motivated parties to offer their computational capacity for the needs of edge computing. Open infrastructure can give an additional boost to this new promising paradigm and, moreover, help to avoid problems for which cloud computing has been long criticized for, such as vendor lock-in or privacy. In this paper, we discuss the challenges related to creating such an open infrastructure, in particular focusing on the applicability of distributed ledgers for contractual agreement and payment. Solving the challenge of contracting is central to realizing an open infrastructure for edge computing, and in this paper, we highlight the potential and shortcomings of distributed ledger technologies in the context of our use case

Security plane for data authentication in information-centric networks

Orientadores: Maurício Ferreira Magalhães, Jussi KangasharjuTese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Elétrica e de ComputaçãoResumo: A segurança da informação é responsável pela proteção das informações contra o acesso nãoautorizado, uso, modificação ou a sua destruição. Com o objetivo de proteger os dados contra esses ataques de segurança, vários protocolos foram desenvolvidos, tais como o Internet Protocol Security (IPSEC) e o Transport Layer Security (TLS), provendo mecanismos de autenticação, integridade e confidencialidade dos dados para os usuários. Esses protocolos utilizam o endereço IP como identificador de hosts na Internet, tornando-o referência e identificador no estabelecimento de conexões seguras para a troca de dados entre aplicações na rede. Com o advento da Web e o aumento exponencial do consumo de conteúdos, como vídeos e áudios, há indícios da migração gradual do uso predominante da Internet, passando da ênfase voltada para a conexão entre hosts para uma ênfase voltada para a obtenção de conteúdo da rede, paradigma esse conhecido como information-centric networking. Nesse paradigma, usuários buscam por documentos e recursos na Internet sem se importarem com o conhecimento explícito da localização do conteúdo. Como consequência, o endereço IP que previamente era utilizado como ponto de referência do provedor de dados, torna-se meramente um identificador efêmero do local onde o conteúdo está armazenado, resultando em implicações para a autenticação correta dos dados. Nesse contexto, a simples autenticação de um endereço IP não garante a autenticidade dos dados, uma vez que o servidor identificado por um dado endereço IP não é necessariamente o endereço do produtor do conteúdo. No contexto de redes orientadas à informação, existem propostas na literatura que possibilitam a autenticação dos dados utilizando somente o conteúdo propriamente dito, como a utilização de assinaturas digitais por bloco de dado e a construção de árvores de hash sobre os blocos de dados. A ideia principal dessas abordagens é atrelar uma informação do provedor original do conteúdo nos blocos de dados transportados, por exemplo, uma assinatura digital, possibilitando a autenticação direta dos dados com o provedor, independentemente do host onde o dado foi obtido. Apesar do mecanismo citado anteriormente possibilitar tal verificação, esse procedimento é muito oneroso do ponto de vista de processamento, especialmente quando o número de blocos é grande, tornando-o inviável de ser utilizado na prática. Este trabalho propõe um novo mecanismo de autenticação utilizando árvores de hash com o objetivo de prover a autenticação dos dados de forma eficiente e explícita com o provedor original e, também, de forma independente do host onde os dados foram obtidos. Nesta tese, propomos duas técnicas de autenticação de dados baseadas em árvores de hash, chamadas de skewed hash tree (SHT) e composite hash tree (CHT), para a autenticação de dados em redes orientadas à informação. Uma vez criadas, parte dos dados de autenticação é armazenada em um plano de segurança e uma outra parte permanece acoplada ao dado propriamente dito, possibilitando a verificação baseada no conteúdo e não no host de origem. Além disso, essa tese apresenta o modelo formal, a especificação e a implementação das duas técnicas de árvore de hash para autenticação dos dados em redes de conteúdo através de um plano de segurança. Por fim, esta tese detalha a instanciação do modelo de plano de segurança proposto em dois cenários de autenticação de dados: 1) redes Peer-to-Peer e 2) autenticação paralela de dados sobre o HTTPAbstract: Information security is responsible for protecting information against unauthorized access, use, modification or destruction. In order to protect such data against security attacks, many security protocols have been developed, for example, Internet Protocol Security (IPSec) and Transport Layer Security (TLS), providing mechanisms for data authentication, integrity and confidentiality for users. These protocols use the IP address as host identifier on the Internet, making it as a reference and identifier during the establishment of secure connections for data exchange between applications on the network. With the advent of the Web and the exponential increase in content consumption (e.g., video and audio), there is an evidence of a gradual migration of the predominant usage of the Internet, moving the emphasis on the connection between hosts to the content retrieval from the network, which paradigm is known as information-centric networking. In this paradigm, users look for documents and resources on the Internet without caring about the explicit knowledge of the location of the content. As a result, the IP address that was used previously as a reference point of a data provider, becomes merely an ephemeral identifier of where the content is stored, resulting in implications for the correct authentication data. In this context, the simple authentication of an IP address does not guarantee the authenticity of the data, because a hosting server identified by a given IP address is not necessarily the same one that is producing the requested content. In the context of information-oriented networks, some proposals in the literature proposes authentication mechanisms based on the content itself, for example, digital signatures over a data block or the usage of hash trees over data blocks. The main idea of these approaches is to add some information from the original provider in the transported data blocks, for example, a digital signature, enabling data authentication directly with the original provider, regardless of the host where the data was obtained. Although the mechanism mentioned previously allows for such verification, this procedure is very costly in terms of processing, especially when the number of blocks is large, making it unfeasible in practice. This thesis proposes a new authentication mechanism using hash trees in order to provide efficient data authentication and explicitly with the original provider, and also independently of the host where the data were obtained. We propose two techniques for data authentication based on hash trees, called skewed hash tree (SHT) and composite hash tree (CHT), for data authentication in information-oriented networks. Once created, part of the authentication data is stored in a security plane and another part remains attached to the data itself, allowing for the verification based on content and not on the source host. In addition, this thesis presents the formal model, specification and implementation of two hash tree techniques for data authentication in information-centric networks through a security plane. Finally, this thesis details the instantiation of the security plane model in two scenarios of data authentication: 1) Peer-to-Peer and 2) parallel data authentication over HTTPDoutoradoEngenharia de ComputaçãoDoutor em Engenharia Elétric

Targeting CXCR4 with CTCE-9908 inhibits prostate tumor metastasis

Abstract Background CXCL12/CXCR4 transactivation of epidermal growth factor family receptors in lipid raft membrane microdomains on cell surface is thought to mediate tumor growth and subsequent development of metastatic disease. CTCE-9908 is a known inhibitor of CXCR4. Herein, we tested the efficacy of CTCE-9908 in inhibiting prostate cancer cell growth, invasion, and metastasis. Methods We used a panel of in vitro assays utilizing human prostate cancer cell lines and an in vivo orthotopic prostate cancer model to assess the anti-tumoral activity of CTCE-9908. Results We demonstrated that (a) CTCE-9908 treatment resulted in no significant change in the growth of PC-3 and C4-2B cells; (b) 50 μg/ml of CTCE-9908 inhibited the invasive properties of PC-3 cells; (c) 25 mg/kg of CTCE-9908 did not alter primary tumor growth but it did significantly reduce total tumor burden in the animal including the growth of prostate and soft tissue metastases to lymph node and distant organ tissues. Histological analysis showed that CTCE-9908 treatment resulted in tumor necrosis in primary prostate tumors and no significant change in proliferation of tumor cells as measured by Ki-67 staining; (d) CTCE-9908 inhibited the tumor angiogenesis as measured by CD34 positive vessels in tumors. Conclusions These data suggest that CXCR4 inhibition by CTCE-9908 decreases the invasion potential in vitro, which then translated to a reduction of tumor spread with associated reduction in angiogenesis. Hence, CTCE-9908 may prove to be an efficacious novel agent to prevent and treat the spread of metastatic prostate cancer

An implementation proposal of a next generation internet architecture

Orientadores: Mauricio Ferreira Magalhães, Fabio Luciano VerdiDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Eletrica e ComputaçãoResumo: A concepção original da arquitetura da Internet foi baseada em uma rede fixa e confiável. Hoje em dia, a Internet se tornou dinâmica e vulnerável aos ataques de segurança. Também não era prevista a necessidade de integração de tecnologias heterogêneas nem de ambientes sem fio. A arquitetura atual apresenta uma série de barreiras técnicas para prover estes serviços, sendo uma das maiores a sobrecarga semântica do Internet Protocol (IP). O endereço IP atua como localizador na camada de rede e como identificador na camada de transporte, impossibilitando novas funcionalidades como a mobilidade e abrindo brechas de segurança. Este trabalho apresenta uma proposta de implementação de uma arquitetura para Internet de nova geração para o provisionamento de novos serviços de forma natural e integrada para a Internet atual. A proposta de arquitetura de implementação oferece suporte à mobilidade, ao multihoming, à segurança, à integração de redes heterogêneas e às aplicações legadas através da introdução de uma nova camada de identificação na arquitetura atual. Esta nova camada tem por objetivo separar a identidade da localização e se tornar uma opção de comunicação para as redes heterogêneas. Mecanismos adicionais foram propostos para prover o suporte às funcionalidades da arquitetura, tais como a resolução de nomes em identificadores, o roteamento baseado no identificador, a gerência de localização e um plano de controle para a troca de mensagens de sinalização fim-a-fim entre os componentes da arquitetura. Para a validação da arquitetura proposta, um protótipo foi implementado e vários testes de desempenho foram realizados para avaliação do overhead da implementação, do modelo de segurança, da robustez e do suporte à mobilidade e às aplicações legadasAbstract: The original concept of the Internet architecture was based on static and reliable networks. Nowadays, the Internet became more dynamic and vulnerable to security attacks. The integration of heterogeneous technologies and wireless environment were not predicted. The current architecture presents some technical barriers to provide these services. One of these problems is the semantic overload of the Internet Protocol (IP). The IP address acts as locator in the network layer and identifier in the transport layer, preventing new features such as mobility and allowing security flaws. This work presents an implementation proposal of a next generation Internet architecture to provide new services naturally integrated to the Internet. The implementation proposal supports mobility, multihoming, security, heterogeneous networks integration and legacy applications by the introduction of a new identification layer in the current architecture. This new layer will separate the identity from the location and become an option for communication between heterogeneous networks. Additional mechanisms were proposed to support the new functionalities of the architecture, e.g., resolution of names to identifiers, identifier-based routing, location management and a control plane to exchange end-toend signalling control messages between the components of the architecture. In order to evaluate the proposed architecture, a prototype was implemented and some tests were performed considering implementation overhead, security model, robustness and support for mobility and legacy applicationsMestradoEngenharia de ComputaçãoMestre em Engenharia Elétric

A Universal Neutral Gas Profile for Nearby Disk Galaxies

Based on sensitive CO measurements from HERACLES and HI data from THINGS, we show that the azimuthally averaged radial distribution of the neutral gas surface density (Sigma_HI + Sigma_H2) in 33 nearby spiral galaxies exhibits a well-constrained universal exponential distribution beyond 0.2*r25 (inside of which the scatter is large) with less than a factor of two scatter out to two optical radii r25. Scaling the radius to r25 and the total gas surface density to the surface density at the transition radius, i.e., where Sigma_HI and Sigma_H2 are equal, as well as removing galaxies that are interacting with their environment, yields a tightly constrained exponential fit with average scale length 0.61+-0.06 r25. In this case, the scatter reduces to less than 40% across the optical disks (and remains below a factor of two at larger radii). We show that the tight exponential distribution of neutral gas implies that the total neutral gas mass of nearby disk galaxies depends primarily on the size of the stellar disk (influenced to some degree by the great variability of Sigma_H2 inside 0.2*r25). The derived prescription predicts the total gas mass in our sub-sample of 17 non-interacting disk galaxies to within a factor of two. Given the short timescale over which star formation depletes the H2 content of these galaxies and the large range of r25 in our sample, there appears to be some mechanism leading to these largely self-similar radial gas distributions in nearby disk galaxies.Comment: 7 pages, 4 figures, accepted for publication in the Astrophysical Journa

Unusually Luminous Giant Molecular Clouds in the Outer Disk of M33

We use high spatial resolution (~7pc) CARMA observations to derive detailed properties for 8 giant molecular clouds (GMCs) at a galactocentric radius corresponding to approximately two CO scale lengths, or ~0.5 optical radii (r25), in the Local Group spiral galaxy M33. At this radius, molecular gas fraction, dust-to-gas ratio and metallicity are much lower than in the inner part of M33 or in a typical spiral galaxy. This allows us to probe the impact of environment on GMC properties by comparing our measurements to previous data from the inner disk of M33, the Milky Way and other nearby galaxies. The outer disk clouds roughly fall on the size-linewidth relation defined by extragalactic GMCs, but are slightly displaced from the luminosity-virial mass relation in the sense of having high CO luminosity compared to the inferred virial mass. This implies a different CO-to-H2 conversion factor, which is on average a factor of two lower than the inner disk and the extragalactic average. We attribute this to significantly higher measured brightness temperatures of the outer disk clouds compared to the ancillary sample of GMCs, which is likely an effect of enhanced radiation levels due to massive star formation in the vicinity of our target field. Apart from brightness temperature, the properties we determine for the outer disk GMCs in M33 do not differ significantly from those of our comparison sample. In particular, the combined sample of inner and outer disk M33 clouds covers roughly the same range in size, linewidth, virial mass and CO luminosity than the sample of Milky Way GMCs. When compared to the inner disk clouds in M33, however, we find even the brightest outer disk clouds to be smaller than most of their inner disk counterparts. This may be due to incomplete sampling or a potentially steeper cloud mass function at larger radii.Comment: Accepted for Publication in ApJ; 7 pages, 4 figure