Optimal deployment of components of cloud-hosted application for guaranteeing multitenancy isolation

One of the challenges of deploying multitenant cloud-hosted services that are designed to use (or be integrated with) several components is how to implement the required degree of isolation between the components when there is a change in the workload. Achieving the highest degree of isolation implies deploying a component exclusively for one tenant; which leads to high resource consumption and running cost per component. A low degree of isolation allows sharing of resources which could possibly reduce cost, but with known limitations of performance and security interference. This paper presents a model-based algorithm together with four variants of a metaheuristic that can be used with it, to provide near-optimal solutions for deploying components of a cloud-hosted application in a way that guarantees multitenancy isolation. When the workload changes, the model based algorithm solves an open multiclass QN model to determine the average number of requests that can access the components and then uses a metaheuristic to provide near-optimal solutions for deploying the components. Performance evaluation showed that the obtained solutions had low variability and percent deviation when compared to the reference/optimal solution. We also provide recommendations and best practice guidelines for deploying components in a way that guarantees the required degree of isolation

Four minutes for a patient, twenty seconds for a relative - an observational study at a university hospital

Abstract Background In the modern hospital environment, increasing possibilities in medical examination techniques and increasing documentation tasks claim the physicians' energy and encroach on their time spent with patients. This study aimed to investigate how much time physicians at hospital wards spend on communication with patients and their families and how much time they spend on other specific work tasks. Methods A non-participatory, observational study was conducted in thirty-six wards at the University Medical Center Freiburg, a 1700-bed academic hospital in Germany. All wards belonging to the clinics of internal medicine, surgery, radiology, neurology, and to the clinic for gynaecology took part in the study. Thirty-four ward doctors from fifteen different medical departments were observed during a randomly chosen complete work day. The Physicians' time for communication with patients and relatives and time spent on different working tasks during one day of work were assessed. Results 374 working hours were analysed. On average, a physician's workday on a university hospital ward added up to 658.91 minutes (10 hrs 58 min; range 490 - 848 min). Looking at single items of time consumption on the evaluation sheet, discussions with colleagues ranked first with 150 minutes on average. Documentation and administrative requirements took an average time of 148 minutes per day and ranked second. Total time for communication with patients and their relatives was 85 minutes per physician and day. Consequently, the available time for communication was 4 minutes and 17 seconds for each patient on the ward and 20 seconds for his or her relatives. Physicians assessed themselves to communicate twice as long with patients and sevenfold with relatives than they did according to this study. Conclusions Workload and time pressure for physicians working on hospital wards are high. To offer excellent medical treatment combined with patient centred care and to meet the needs of patients and relatives on hospital wards, physicians should be given more time to focus on core clinical tasks. Time and health care management solutions to minimize time pressure are required. Further research is needed to assess quality of communication in hospital settings.</p

Palliative Cancer Care: An Epidemiologic Study

Purpose To analyze the need for palliative care in hospital patients who have cancer. Palliative care is an essential component of comprehensive cancer care and identification of palliative care needs (PCNs) of patients with cancer is a topic that has not been thoroughly studied. Patients and Methods Data were collected prospectively from inpatients of University Medical Center Freiburg in Freiburg, Germany, with 982 hospital beds included in the study. During the observation period of 17 months, each patient discharged from a hospital ward was screened by surveying the treating physician who was responsible for dismissal about patients' PCNs based on the WHO 1990 definition of palliative care. To complete obligatory electronic discharge management, a modified dismissal form asking to classify the patient as having PCN "yes/no" had to be filled out for each patient discharged. Results The response rate was 96% with data for 39,849 patients that could be analyzed. A total of 6.9% of all hospital patients and 9.1% of patients older than age 65 years were considered to have PCNs. Of the 2,757 patients with PCNs, 67% (n = 1,836) had cancer. Among the 11,584 patients with cancer, 15.8% were classified as having PCNs. PCNs were particularly high in patients with head and neck cancer (28.3%), malignant melanoma (26.0%), and brain tumors (18.2%). Suffering from cancer increases the probability of developing PCNs by a factor of 3.63 (95% CI, 3.27 to 4.04). For patients with metastatic cancer, the risk of developing PCNs is increased 12-fold (odds ratio, 12.27; 95% CI, 11.07 to 13.60). Conclusion Structures to provide palliative care for patients with cancer are needed. J Clin Oncol 29: 646-650. (C) 2011 by American Society of Clinical Oncolog