Content Delivery and Sharing in Federated Cloud Storage

Cloud-based storage is becoming a cost-effective solution for agencies, hospitals, government instances and scientific centers to deliver and share contents to/with a set of end-users. However, reliability, privacy and lack of control are the main problems that arise when contracting content delivery services with a single cloud storage provider. This paper presents the implementation of a storage system for content delivery and sharing in federated cloud storage networks. This system virtualizes the storage resources of a set of organizations as a single federated system, which is in charge of the content storage. The architecture includes a metadata management layer to keep the content delivery control in-house and a storage synchronization worker/monitor to keep the state of storage resources in the federation as well as to send contents near to the end-users. It also includes a redundancy layer based on a multi-threaded engine that enables the system to withstand failures in the federated network. We developed a prototype based on this scheme as a proof of concept. The experimental evaluation shows the benefits of building content delivery systems in federated cloud environments, in terms of performance, reliability and profitability of the storage space.The work presented in this paper has been partially supported by EU under the COST programme Action IC1305, Network for Sustainable Ultrascale Computing (NESUS)

CloudChain: A novel distribution model for digital products based on supply chain principles

Cloud computing is a popular outsourcing solution for organizations to support the information management during the life cycle of digital information goods. However, outsourcing management with a public provider results in a lack of control over digital products, which could produce incidents such as data unavailability during service outages, violations of confidentiality and/or legal issues. This paper presents a novel distribution model of digital products inspired by lean supply chain principles called CloudChain, which has been designed to support the information management during digital product lifecycle. This model enables connected networks of customers, partners and organizations to conduct the stages of digital product lifecycle as value chains. Virtual distribution channels are created over cloud resources for applications of organizations to deliver digital products to applications of partners through a seamless information flow. A configurable packing and logistic service was developed to ensure confidentiality and privacy in the product delivery by using encrypted packs. A chain management architecture enables organizations to keep tighter control over their value chains, distribution channels and digital products. CloudChain software instances were integrated to an information management system of a space agency. In an experimental evaluation CloudChain prototype was evaluated in a private cloud where the feasibility of applying supply chain principles to the delivery of digital products in terms of efficiency, flexibility and security was revealed.This work was partially funded by the sectorial fund of research, technological development and innovation in space activities of the Mexican National Council of Science and Technology (CONACYT) and the Mexican Space Agency (AEM), project No. 262891

SkyCDS: A resilient content delivery service based on diversified cloud storage

Cloud-based storage is a popular outsourcing solution for organizations to deliver contents to end-users. However, there is a need for contingency plans to ensure service provision when the provider either suffers outages or is going out of business. This paper presents SkyCDS: a resilient content delivery service based on a publish/subscribe overlay over diversified cloud storage. SkyCDS splits the content delivery into metadata and content storage flow layers. The metadata flow layer is based on publish-subscribe patterns for insourcing the metadata control back to content owner. The storage layer is based on dispersal information over multiple cloud locations with which organizations outsource content storage in a controlled manner. In SkyCDS, the content dispersion is performed on the publisher side and the content retrieving process on the end-user side (the subscriber), which reduces the load on the organization side only to metadata management. SkyCDS also lowers the overhead of the content dispersion and retrieving processes by taking advantage of multi-core technology. A new allocation strategy based on cloud storage diversification and failure masking mechanisms minimize side effects of temporary, permanent cloud-based service outages and vendor lock-in. We developed a SkyCDS prototype that was evaluated by using synthetic workloads and a study case with real traces. Publish/subscribe queuing patterns were evaluated by using a simulation tool based on characterized metrics taken from experimental evaluation. The evaluation revealed the feasibility of SkyCDS in terms of performance, reliability and storage space profitability. It also shows a novel way to compare the storage/delivery options through risk assessment. (C) 2015 Elsevier B.V. All rights reserved.The work presented in this paper has been partially supported by EU under the COST programme Action IC1305, Network for Sustainable Ultrascale Computing (NESUS)

Estudio de las lesiones neoplásicas metacrónicas en el carcinoma colorrectal

Fundamento. Analizar la frecuencia y las características de las lesiones neoplásicas metacrónicas, carcinomas y adenomas, tras la resección de un cáncer colo-rectal (CCR). Pacientes y métodos. Revisamos 382 CCR operados y seguidos mediante colonoscopias completas en dos hospitales de nuestra comunidad. Analizamos las lesiones metacrónicas registradas valorando su localización, momento del diagnóstico, histología, número y tamaño. Estudiamos la frecuencia de adenomas de aparición precoz (12 meses), comparando su tamaño con respecto al resto de lesiones. Resultados. La mediana de seguimiento fue de 48 meses (12-112), con 2,74±1,47 colonoscopias/caso. Diagnosticamos 7 cánceres metacrónicos (1,8%), 4 de ellos en estadio I. La mediana de tiempo hasta su diagnóstico fue de 24 meses (13-54). Registramos adenomas metacrónicos en 162 casos (42,4%), sin diferencias entre los dos hospitales: 42,1% vs. 43,8% (p=0,88). Un 6,3% de los pacientes presentaron adenomas avanzados. En 164 casos en que el primer control se efectuó a los 12 meses, la incidencia de adenomas fue del 24%. Los adenomas fueron mayoritariamente únicos (60,8%) y menores de 5 mm (68,5%). En un 55,5% de los casos con pólipos, alguno tenía una localización proximal. El diagnóstico se realizó en la 1ª exploración (56,2%), 2ª (27,8%) ó 3ª (9%). La mediana de tiempo hasta el diagnóstico fue de 21 meses (12-112) para el adenoma simple y de 35 (12-112) para el avanzado. Conclusiones. Nuestro seguimiento permitió aplicar un tratamiento teóricamente curativo en la mayoría de los carcinomas metacrónicos diagnosticados. La alta incidencia de adenomas y su frecuente localización proximal hacen necesario un seguimiento con colonoscopias completas, que debería iniciarse al año de la operación y podría pasar a ser menos estricto tras tres exploraciones consecutivas sin pólipos

Capsule endoscopy interpretation: the role of physician extenders

Background and aims: capsule endoscopy (CE) allows for a new era in small-bowel examination. Nevertheless, physicians’ time for CE-interpretation remains longer than desirable. Alternative strategies to physicians have not been widely investigated. The aim of this study was to evaluate the accuracy of physician extenders in CE-interpretation. Material and methods: one CE-experienced gastroenterologist and two physician extenders reviewed independently 20 CEprocedures. Each reader was blinded to the findings of their colleagues. A consensus formed by the readers and a second CE-experienced gastroenterologist was used as gold standard. Number, type and location of images selected, character of CEexams and their relationship with indications were recorded. Gastric emptying time (GEt), small-bowel transit time (SBTt) and time spent by readers were also noted. Results: sensitivity and specificity for “overall” lesions was 79 and 99% for the gastroenterologist; 86 and 43% for the nurse; and 80 and 57% for the resident. All 34 “major” lesions considered by consensus were found by the readers. Agreement between consensus and readers for images classification and procedures interpretation was good to excellent (κ from 0.55 to 1). No significant differences were found in the GEt and SBTt obtained by consensus and readers. The gastroenterologist was faster than physician extenders (mean time spent was 51.9 ± 13.5 minutes versus 62.2 ± 19 and 60.9 ± 17.1 for nurse and resident, respectively; p < 0.05). Conclusions: physician extenders could be the perfect complement to gastroenterologists for CE-interpretation but gastroenterologists should supervise their findings. Future cost-efficacy analyses are required to assess the benefits of this alternative

Gastroduodenal injury after radioembolization of hepatic tumors

Radioembolization is a new tool for the treatment of hepatic tumors that consists in the injection of biocompatible microspheres carrying radioisotopes into the hepatic artery or its branches. METHODS: We have performed radioembolization in 78 patients with hepatic tumors using resin-based microspheres loaded with yttrium-90. All patients were previously evaluated to minimize the risk of hazardous irradiation to nontarget organs and to obtain the data needed for dose calculation. RESULTS: We report a complication found in three cases (3.8%) that consists of abdominal pain resulting from gastroduodenal lesions and that had a chronic, insidious course. Microscopically, microspheres were detected in the specimens obtained from all affected gastric areas. Since these gastroduodenal lesions do not appear when nonradiating microspheres are injected in animals, lesions are likely to be due to radiation and not to an ischemic effect of vascular occlusion by spheres. CONCLUSIONS: We believe that a pretreatment evaluation that includes a more thorough scrutiny of the hepatic vascularization in search of small collaterals connecting to the gastroduodenal tract can help prevent this awkward complicatio

Mural Endocarditis: The GAMES Registry Series and Review of the Literature

Spanish Collaboration on Endocarditis—Grupo de Apoyo al Manejo de la Endocarditis infecciosa en España (GAMES).[Introduction] Mural infective endocarditis (MIE) is a rare type of endovascular infection. We present a comprehensive series of patients with mural endocarditis.[Methods] Patients with infectious endocarditis (IE) from 35 Spanish hospitals were prospectively included in the GAMES registry between 2008 and 2017. MIEs were compared to non-MIEs. We also performed a literature search for cases of MIE published between 1979 and 2019 and compared them to the GAMEs series.[Results] Twenty-seven MIEs out of 3676 IEs were included. When compared to valvular IE (VIE) or device-associated IE (DIE), patients with MIE were younger (median age 59 years, p < 0.01). Transplantation (18.5% versus 1.6% VIE and 2% DIE, p < 0.01), hemodialysis (18.5% versus 4.3% VIE and 4.4% DIE, p = 0.006), catheter source (59.3% versus 9.7% VIE and 8.8% DIE, p < 0.01) and Candida etiology (22.2% versus 2% DIE and 1.2% VIE, p < 0.01) were more common in MIE, whereas the Charlson Index was lower (4 versus 5 in non-MIE, p = 0.006). Mortality was similar. MIE from the literature shared many characteristics with MIE from GAMES, although patients were younger (45 years vs. 56 years, p < 0.001), the Charlson Index was lower (1.3 vs. 4.3, p = 0.0001), catheter source was less common (13.9% vs. 59.3%) and there were more IVDUs (25% vs. 3.7%). S. aureus was the most frequent microorganism (50%, p = 0.035). Systemic complications were more common but mortality was similar.[Conclusion] MIE is a rare entity. It is often a complication of catheter use, particularly in immunocompromised and hemodialysis patients. Fungal etiology is common. Mortality is similar to other IEs.Peer reviewe