Control Plane Compression

We develop an algorithm capable of compressing large networks into a smaller ones with similar control plane behavior: For every stable routing solution in the large, original network, there exists a corresponding solution in the compressed network, and vice versa. Our compression algorithm preserves a wide variety of network properties including reachability, loop freedom, and path length. Consequently, operators may speed up network analysis, based on simulation, emulation, or verification, by analyzing only the compressed network. Our approach is based on a new theory of control plane equivalence. We implement these ideas in a tool called Bonsai and apply it to real and synthetic networks. Bonsai can shrink real networks by over a factor of 5 and speed up analysis by several orders of magnitude.Comment: Extended version of the paper appearing in ACM SIGCOMM 201

Morphological variability of the Aspius aspius taeniatus (Eichwald, 1831) in the Southern Caspian Sea Basin

Traditional morphometric measurements and meristic counts were used to investigate the hypothesis of population fragmentation of Mash mahi, Aspius aspius taeniatus (Eichwald, 1831) among two fishing areas in southern Caspian Sea basin (Tonekabon:32 specimens and Sari:34 specimens ). Univariate analysis of variance showed significant differences between the means of the two groups for 12 out of 26 standardized morphometric measurement and three out of nine meristic counts. In discriminant function analysis (DFA), the proportion of individuals correctly classified into their original groups was 82.1% and 61.2% for morphometric and meristic characteristics, respectively. Clustering based on Euclidean distances among groups of centroids using an UPGMA and also principal component analysis’ results (PCA) for morphometric and meristic data indicated that two samples of Mash mahi were distinct from each other in these regions, while there were a relatively high degree of overlap between two locations

The Architectural Competition. Research Inquiries and Experiences

This publication is an anthology featuring 26 papers presented at the Conference on Architectural Competitions organised by the School of Architecture and the Built Environment at KTH Royal Institute of Technology in Stockholm from the 16th to the 18th October 2008. What can be learnt from the Stockholm Conference? Firstly, whilst there is only limited research being carried out, at separate universities and institutions focusing on the study of architectural competitions in Europe, there is a vast potential for further research into how architectural firms, their affiliated architectural associations and the competition organisers can cooperate to improve competition processes and outcomes. Secondly, it has demonstrated that both researchers and professional practices can benefit from the development of robust, two-way communication aimed at bothdispelling the myths associated with the architectural competition and to test its perceived realities. For these reasons we hope this anthology will support the establishment and maintenance of a network that will promote communication between the various architectural competition stakeholders and further encourage the exchange of information and knowledge sharing. The conference has demonstrated that scientific research into the architectural competition can offer a multifaceted field of study of significant importance to university based researchers, practicing architects and urban planners alike. By learning from the Stockholm conference, we can reflect upon the various research challenges that will occur in the future and rethink the use of competitions as a design tool to facilitate the production of innovative ideas, improve standards and the commissioning of projects

Effects of different levels of energy and protein sources on the growth performance, feeding, survival rate and the chemical body composition of juvenile Pacific white shrimp (Litopenaeus vannamei)

The present study was carried out in order to establish an economical effective diet for the Pacific white shrimp in the southern part conditions of Iran. Three dietary energy levels (E1=262, E2=312, E3=362 Kcal 100 g^-1 diet) and 6 ratios of fish meal (FM): soybean meal (SBM) [(P1= 100% FM+ 0% SBM), (P2= 80% FM+ 20% SBM), (P3= 60% FM+ 40% SBM), (P4= 40% FM+ 60% SBM), (P5= 20% FM+ 80% SBM), (P6= 0% FM+ 100% SBM)], 18 experimental diets were prepared. Completely randomized design was used to assign 54 polyethylene 300 litre round tanks provided by aeration and was stocked by 19 juvenile shrimp as 3 replicates to each treatment. Shrimps average weight was about 0.77 g at the start. After 56 days culture period, maximum growth and nutritional performance were observed in the P6E1 and P5E1 treatments. In addition, the highest survival rate of the shrimps was observed in the P1E1, P1E2, P3E3 and P5E3 treatments. Results indicated that protein, fat, fiber and ash contents of carcase were significantly affected by the treatments (P<0.05). Results of the present study suggest the replacement possibility of at least 80% of dietary fishmeal by soybean meal in the diet of Pacific white shrimp in the conditions of southern part of Iran

Clinical Outcomes, Costs, and Cost-effectiveness of Strategies for Adults Experiencing Sheltered Homelessness During the COVID-19 Pandemic

Importance: Approximately 356 000 people stay in homeless shelters nightly in the United States. They have high risk of contracting coronavirus disease 2019 (COVID-19). / Objective: To assess the estimated clinical outcomes, costs, and cost-effectiveness associated with strategies for COVID-19 management among adults experiencing sheltered homelessness. / Design, Setting, and Participants: This decision analytic model used a simulated cohort of 2258 adults residing in homeless shelters in Boston, Massachusetts. Cohort characteristics and costs were adapted from Boston Health Care for the Homeless Program. Disease progression, transmission, and outcomes data were taken from published literature and national databases. Surging, growing, and slowing epidemics (effective reproduction numbers [Re], 2.6, 1.3, and 0.9, respectively) were examined. Costs were from a health care sector perspective, and the time horizon was 4 months, from April to August 2020. / Exposures: Daily symptom screening with polymerase chain reaction (PCR) testing of individuals with positive symptom screening results, universal PCR testing every 2 weeks, hospital-based COVID-19 care, alternative care sites (ACSs) for mild or moderate COVID-19, and temporary housing were each compared with no intervention. / Main Outcomes and Measures: Cumulative infections and hospital-days, costs to the health care sector (US dollars), and cost-effectiveness, as incremental cost per case of COVID-19 prevented. / Results: The simulated population of 2258 sheltered homeless adults had a mean (SD) age of 42.6 (9.04) years. Compared with no intervention, daily symptom screening with ACSs for pending tests or confirmed COVID-19 and mild or moderate disease was associated with 37% fewer infections (1954 vs 1239) and 46% lower costs ($6.10 million vs$3.27 million) at an Re of 2.6, 75% fewer infections (538 vs 137) and 72% lower costs ($1.46 million vs$0.41 million) at an Re of 1.3, and 51% fewer infections (174 vs 85) and 51% lower costs ($0.54 million vs$0.26 million) at an Re of 0.9. Adding PCR testing every 2 weeks was associated with a further decrease in infections; incremental cost per case prevented was $1000 at an Re of 2.6,$27 000 at an Re of 1.3, and $71 000 at an Re of 0.9. Temporary housing with PCR every 2 weeks was most effective but substantially more expensive than other options. Compared with no intervention, temporary housing with PCR every 2 weeks was associated with 81$39.12 million) at an Re of 2.6, 82% fewer infections (95) and 2568% higher costs ($38.97 million) at an Re of 1.3, and 59$38.94 million) at an Re of 0.9. Results were sensitive to cost and sensitivity of PCR and ACS efficacy in preventing transmission. / Conclusions and Relevance: In this modeling study of simulated adults living in homeless shelters, daily symptom screening and ACSs were associated with fewer severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections and decreased costs compared with no intervention. In a modeled surging epidemic, adding universal PCR testing every 2 weeks was associated with further decrease in SARS-CoV-2 infections at modest incremental cost and should be considered during future surges

Cost-effectiveness of public health strategies for COVID-19 epidemic control in South Africa

Background Healthcare resource constraints in low and middle-income countries necessitate selection of cost-effective public health interventions to address COVID-19. Methods We developed a dynamic COVID-19 microsimulation model to evaluate clinical and economic outcomes and cost-effectiveness of epidemic control strategies in KwaZulu-Natal, South Africa. Interventions assessed were Healthcare Testing (HT), where diagnostic testing is performed only for those presenting to healthcare centres; Contact Tracing (CT) in households of cases; Isolation Centres (IC), for cases not requiring hospitalisation; community health worker-led Mass Symptom Screening and diagnostic testing for symptomatic individuals (MS); and Quarantine Centres (QC), for contacts who test negative. Given uncertainties about epidemic dynamics in South Africa, we evaluated two main epidemic scenarios over 360 days, with effective reproduction numbers (R e ) of 1.5 and 1.2. We compared HT, HT+CT, HT+CT+IC, HT+CT+IC+MS, HT+CT+IC+QC, and HT+CT+IC+MS+QC, considering strategies with incremental cost-effectiveness ratio (ICER) <US$1,290/year-of-life saved (YLS) to be cost-effective. Findings With R e 1.5, HT resulted in the most COVID-19 deaths and lowest costs over 360 days. Compared with HT, HT+CT+IC+MS reduced mortality by 76$350/YLS). HT+CT+IC+MS+QC provided the greatest reduction in mortality, but increased costs by 95% compared with HT+CT+IC+MS and was not cost-effective (ICER $8,000/YLS). With R e 1.2, HT+CT+IC+MS was the least costly strategy, and HT+CT+IC+MS+QC was not cost-effective (ICER$294,320/YLS). Interpretation In South Africa, a strategy of household contact tracing, isolation, and mass symptom screening would substantially reduce COVID-19 mortality and be cost-effective. Adding quarantine centres for COVID-19 contacts is not cost-effective

Cost-effectiveness of public health strategies for COVID-19 epidemic control in South Africa: a microsimulation modelling study

Background: Health-care resource constraints in low-income and middle-income countries necessitate the identification of cost-effective public health interventions to address COVID-19. We aimed to develop a dynamic COVID-19 microsimulation model to assess clinical and economic outcomes and cost-effectiveness of epidemic control strategies in KwaZulu-Natal province, South Africa. Methods: We compared different combinations of five public health interventions: health-care testing alone, where diagnostic testing is done only for individuals presenting to health-care centres; contact tracing in households of cases; isolation centres, for cases not requiring hospital admission; mass symptom screening and molecular testing for symptomatic individuals by community health-care workers; and quarantine centres, for household contacts who test negative. We calibrated infection transmission rates to match effective reproduction number (Re) estimates reported in South Africa. We assessed two main epidemic scenarios for a period of 360 days, with an Re of 1·5 and 1·2. Strategies with incremental cost-effectiveness ratio (ICER) of less than US$3250 per year of life saved were considered cost-effective. We also did sensitivity analyses by varying key parameters (Re values, molecular testing sensitivity, and efficacies and costs of interventions) to determine the effect on clinical and cost projections. Findings: When Re was 1·5, health-care testing alone resulted in the highest number of COVID-19 deaths during the 360-day period. Compared with health-care testing alone, a combination of health-care testing, contact tracing, use of isolation centres, mass symptom screening, and use of quarantine centres reduced mortality by 94$340 per year of life saved). In settings where quarantine centres were not feasible, a combination of health-care testing, contact tracing, use of isolation centres, and mass symptom screening was cost-effective compared with health-care testing alone (ICER $590 per year of life saved). When Re was 1·2, health-care testing, contact tracing, use of isolation centres, and use of quarantine centres was the least costly strategy, and no other strategies were cost-effective. In sensitivity analyses, a combination of health-care testing, contact tracing, use of isolation centres, mass symptom screening, and use of quarantine centres was generally cost-effective, with the exception of scenarios in which Re was 2·6 and when efficacies of isolation centres and quarantine centres for transmission reduction were reduced. Interpretation: In South Africa, strategies involving household contact tracing, isolation, mass symptom screening, and quarantining household contacts who test negative would substantially reduce COVID-19 mortality and would be cost-effective. The optimal combination of interventions depends on epidemic growth characteristics and practical implementation considerations

Global analysis of Drosophila Cys2-His2 zinc finger proteins reveals a multitude of novel recognition motifs and binding determinants

Cys2-His2 zinc finger proteins (ZFPs) are the largest group of transcription factors in higher metazoans. A complete characterization of these ZFPs and their associated target sequences is pivotal to fully annotate transcriptional regulatory networks in metazoan genomes. As a first step in this process, we have characterized the DNA-binding specificities of 129 zinc finger sets from Drosophila using a bacterial one-hybrid system. This data set contains the DNA-binding specificities for at least one encoded ZFP from 70 unique genes and 23 alternate splice isoforms representing the largest set of characterized ZFPs from any organism described to date. These recognition motifs can be used to predict genomic binding sites for these factors within the fruit fly genome. Subsets of fingers from these ZFPs were characterized to define their orientation and register on their recognition sequences, thereby allowing us to define the recognition diversity within this finger set. We find that the characterized fingers can specify 47 of the 64 possible DNA triplets. To confirm the utility of our finger recognition models, we employed subsets of Drosophila fingers in combination with an existing archive of artificial zinc finger modules to create ZFPs with novel DNA-binding specificity. These hybrids of natural and artificial fingers can be used to create functional zinc finger nucleases for editing vertebrate genomes