25 research outputs found
Non-Deployable Miniaturized Quadslot Antenna for Cubesats
The combination of the structural panels of a 1U cubesat and their air gaps can form a quadslot antenna. This type of antenna eliminates the need for a deployment mechanism and reduces the risk of a disconnection from the satellite. The electrical field constructs in an air gap at the corner of two panels, and when all four panels are powered the antenna emits a semi-omnidirectional radiation pattern similar to a dipole. Unlike a dipole, it can radiate up to 5dB of gain instead of 2.15dB. Another benefit to this antenna is its ability to have sensors and or solar cells on the panels without interfering with the radiation pattern. This is because each panel serves two electrical purposes: increasing the electrical length to reduce frequency and providing space for miscellaneous electrical hardware. Overall, this type of antenna provides the same capability as an L-dipole or patch antenna without sacrificing space, increasing cost, or cumulating more risk. The design allows for a variety of flexibility in frequency, bandwidth, physical size, or construction. This was designed and developed at California Polytechnic State University
Noble Systems Inc.: Inside The Mind Of An Entrepreneur
This case illustrates the challenges faced by typical start-up businesses. The company has never earned a profit. Losses are being covered by cash infusions from angel investors. While significant business opportunities are present, the company doesnt have the money to pursue them all. Essentially, the case involves problems of growth, vision, potential, and management. The problems illustrated in the case can be analyzed using theories and approaches such as: SWOT analysis, financial analysis, business valuation, strategic human resource management, and strategic marketing/management. The case and Instructors Manual were written for undergraduate or MBA courses in strategic management. They can also be used in an entrepreneurship course if the instructor wishes to have a case that illustrates the strategic challenges associated with the decision whether to stay small and within the abilities of the founders, or to grow beyond their capabilities
Competition In The eLearning Industry: A Case Study
This paper highlights the structural attributes of the eLearning Industry. The case presents details regarding the evolution of the eLearning market and provides the opportunity for students of strategic management to build critical industry analytical skills by applying a variety of techniques highlighted in the accompanying case teaching note. To obtain a copy of the teaching note, contact the corresponding author by email. The analytical techniques applied include the identification of the chief economic characteristics of the industry, Porter’s five force model of competition, the impact of driving forces on industry structure, and the identification of necessary competitive capabilities (success factors) for success in the eLearning industry
Multiple novel prostate cancer susceptibility signals identified by fine-mapping of known risk loci among Europeans
Genome-wide association studies (GWAS) have identified numerous common prostate cancer (PrCa) susceptibility loci. We have
fine-mapped 64 GWAS regions known at the conclusion of the iCOGS study using large-scale genotyping and imputation in
25 723 PrCa cases and 26 274 controls of European ancestry. We detected evidence for multiple independent signals at 16
regions, 12 of which contained additional newly identified significant associations. A single signal comprising a spectrum of
correlated variation was observed at 39 regions; 35 of which are now described by a novel more significantly associated lead SNP,
while the originally reported variant remained as the lead SNP only in 4 regions. We also confirmed two association signals in
Europeans that had been previously reported only in East-Asian GWAS. Based on statistical evidence and linkage disequilibrium
(LD) structure, we have curated and narrowed down the list of the most likely candidate causal variants for each region.
Functional annotation using data from ENCODE filtered for PrCa cell lines and eQTL analysis demonstrated significant
enrichment for overlap with bio-features within this set. By incorporating the novel risk variants identified here alongside the
refined data for existing association signals, we estimate that these loci now explain ∼38.9% of the familial relative risk of PrCa,
an 8.9% improvement over the previously reported GWAS tag SNPs. This suggests that a significant fraction of the heritability of
PrCa may have been hidden during the discovery phase of GWAS, in particular due to the presence of multiple independent
signals within the same regio
Adding 6 months of androgen deprivation therapy to postoperative radiotherapy for prostate cancer: a comparison of short-course versus no androgen deprivation therapy in the RADICALS-HD randomised controlled trial
Background
Previous evidence indicates that adjuvant, short-course androgen deprivation therapy (ADT) improves metastasis-free survival when given with primary radiotherapy for intermediate-risk and high-risk localised prostate cancer. However, the value of ADT with postoperative radiotherapy after radical prostatectomy is unclear.
Methods
RADICALS-HD was an international randomised controlled trial to test the efficacy of ADT used in combination with postoperative radiotherapy for prostate cancer. Key eligibility criteria were indication for radiotherapy after radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to radiotherapy alone (no ADT) or radiotherapy with 6 months of ADT (short-course ADT), using monthly subcutaneous gonadotropin-releasing hormone analogue injections, daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as distant metastasis arising from prostate cancer or death from any cause. Standard survival analysis methods were used, accounting for randomisation stratification factors. The trial had 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 80% to 86% (hazard ratio [HR] 0·67). Analyses followed the intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and ClinicalTrials.gov, NCT00541047.
Findings
Between Nov 22, 2007, and June 29, 2015, 1480 patients (median age 66 years [IQR 61–69]) were randomly assigned to receive no ADT (n=737) or short-course ADT (n=743) in addition to postoperative radiotherapy at 121 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 9·0 years (IQR 7·1–10·1), metastasis-free survival events were reported for 268 participants (142 in the no ADT group and 126 in the short-course ADT group; HR 0·886 [95% CI 0·688–1·140], p=0·35). 10-year metastasis-free survival was 79·2% (95% CI 75·4–82·5) in the no ADT group and 80·4% (76·6–83·6) in the short-course ADT group. Toxicity of grade 3 or higher was reported for 121 (17%) of 737 participants in the no ADT group and 100 (14%) of 743 in the short-course ADT group (p=0·15), with no treatment-related deaths.
Interpretation
Metastatic disease is uncommon following postoperative bed radiotherapy after radical prostatectomy. Adding 6 months of ADT to this radiotherapy did not improve metastasis-free survival compared with no ADT. These findings do not support the use of short-course ADT with postoperative radiotherapy in this patient population
Duration of androgen deprivation therapy with postoperative radiotherapy for prostate cancer: a comparison of long-course versus short-course androgen deprivation therapy in the RADICALS-HD randomised trial
Background
Previous evidence supports androgen deprivation therapy (ADT) with primary radiotherapy as initial treatment for intermediate-risk and high-risk localised prostate cancer. However, the use and optimal duration of ADT with postoperative radiotherapy after radical prostatectomy remains uncertain.
Methods
RADICALS-HD was a randomised controlled trial of ADT duration within the RADICALS protocol. Here, we report on the comparison of short-course versus long-course ADT. Key eligibility criteria were indication for radiotherapy after previous radical prostatectomy for prostate cancer, prostate-specific antigen less than 5 ng/mL, absence of metastatic disease, and written consent. Participants were randomly assigned (1:1) to add 6 months of ADT (short-course ADT) or 24 months of ADT (long-course ADT) to radiotherapy, using subcutaneous gonadotrophin-releasing hormone analogue (monthly in the short-course ADT group and 3-monthly in the long-course ADT group), daily oral bicalutamide monotherapy 150 mg, or monthly subcutaneous degarelix. Randomisation was done centrally through minimisation with a random element, stratified by Gleason score, positive margins, radiotherapy timing, planned radiotherapy schedule, and planned type of ADT, in a computerised system. The allocated treatment was not masked. The primary outcome measure was metastasis-free survival, defined as metastasis arising from prostate cancer or death from any cause. The comparison had more than 80% power with two-sided α of 5% to detect an absolute increase in 10-year metastasis-free survival from 75% to 81% (hazard ratio [HR] 0·72). Standard time-to-event analyses were used. Analyses followed intention-to-treat principle. The trial is registered with the ISRCTN registry, ISRCTN40814031, and
ClinicalTrials.gov
,
NCT00541047
.
Findings
Between Jan 30, 2008, and July 7, 2015, 1523 patients (median age 65 years, IQR 60–69) were randomly assigned to receive short-course ADT (n=761) or long-course ADT (n=762) in addition to postoperative radiotherapy at 138 centres in Canada, Denmark, Ireland, and the UK. With a median follow-up of 8·9 years (7·0–10·0), 313 metastasis-free survival events were reported overall (174 in the short-course ADT group and 139 in the long-course ADT group; HR 0·773 [95% CI 0·612–0·975]; p=0·029). 10-year metastasis-free survival was 71·9% (95% CI 67·6–75·7) in the short-course ADT group and 78·1% (74·2–81·5) in the long-course ADT group. Toxicity of grade 3 or higher was reported for 105 (14%) of 753 participants in the short-course ADT group and 142 (19%) of 757 participants in the long-course ADT group (p=0·025), with no treatment-related deaths.
Interpretation
Compared with adding 6 months of ADT, adding 24 months of ADT improved metastasis-free survival in people receiving postoperative radiotherapy. For individuals who can accept the additional duration of adverse effects, long-course ADT should be offered with postoperative radiotherapy.
Funding
Cancer Research UK, UK Research and Innovation (formerly Medical Research Council), and Canadian Cancer Society
Team Ware an Online Moderated Class Discussion Facility and Beyond
In this paper we discuss the development of an electronic class room discussion facility to train students in the use of electronic meeting rooms for decision-making and problem-solving. This system can be used for other experiential learning exercises such as role playing and negotiation exercises. The paper focuses on the development of a discussion facility for meetings held in the same room. Other types of similar online systems are discussed and their implications reviewed. We also discuss the application of such tools for distance learning systems
The Relationship between Goal Orientation and Simulation Performance with Attitude Change and Perceived Learning: A Follow-Up Study
This study is a follow-up to further explore the relationship between the students’ goal orientation, their success on a simulation exercise, and their perceptions of its value. As with the earlier study, the relationships between financial performance on the simulation and student perceptions of its attractiveness as an educational pedagogy were not significantly moderated by the goal orientation of the student. Limitations and directions for future research are explored
Nightingale: A New Two-Server Approach for Authentication with Short Secrets
Passwords and PINs continue to remain the most widespread forms of user authentication, despite growing awareness of their security limitations. This is because short secrets are convenient, particularly for an increasingly mobile user population. Many users are interested in employing a variety of computing devices with different forms of connectivity and different software platforms. Such users often find it convenient to authenticate by means of passwords and short secrets, to recover lost passwords by answering personal or “life” questions, and to make similar use of relatively weak secrets. In typical authentication methods based on short secrets, the secrets (or related values) are stored in a central database. Often overlooked is the vulnerability of the secrets to theft en bloc in the event of server compromise. With this in mind, Ford and Kaliski and others have proposed various password “hardening ” schemes involving multiple servers, with password privacy assured provided that some servers remain uncompromised. In this paper, we describe a new, two-server secure roaming system that benefits from an especially lightweight new set of protocols. In contrast to previous ideas, ours can be implemented so as to require essentially no intensive cryptographic computation by clients. This and other design features render the system, in our view, the most practical proposal to date in this area. We describe in this paper the protocol and implementation challenges and the design choices underlying the system.