title: Towards Internet scale simulation

authors: McGregor, Anthony James

subjects: Discrete Event Simulation

abstract: Simulation of the Internet has long been understood to be very challenging mostly because of its scale, diversity and the lack of detailed knowledge of many of its components. However, two recent developments (macroscopic topology discovery and large memory servers) mean that some of these problems are now more tractable. Although problems like the lack of detailed link information remain, models are are useful for some problems that require an understanding of how an application interacts with the Internet as a whole. The paper presents is-0, an Internet Simulator. is-0 derives its model of Internet topology directly from the output of an Internet topology mapping project. Efficient design allows is-0 to simulate packet-by-packet, hop-by-hop behaviour at Internet scale. Validation of is-0, an example application and performance measurements are included.

text: Towards Internet scale simulation Simulation of the Internet has long been understood to be very challenging mostly because of its scale, diversity and the lack of detailed knowledge of many of its components. However, two recent developments (macroscopic topology discovery and large memory servers) mean that some of these problems are now more tractable. Although problems like the lack of detailed link information remain, models are are useful for some problems that require an understanding of how an application interacts with the Internet as a whole. The paper presents is-0, an Internet Simulator. is-0 derives its model of Internet topology directly from the output of an Internet topology mapping project. Efficient design allows is-0 to simulate packet-by-packet, hop-by-hop behaviour at Internet scale. Validation of is-0, an example application and performance measurements are included.

year: 2011

title: The effect of eccentric cycle training on physiological and performance parameters in cycling.

authors: Dillon, Piers, Callum

abstract: Prior research has demonstrated the benefits of 3 to 8 weeks of eccentric cycle  training in athletes, the elderly, and in suffers of various pathophysiological conditions. Eccentric cycling requires participants to absorb force generated by an electric motor that drives a traditional cycle crank in a reverse fashion. Relative to traditional concentric cycle training, eccentric cycling is lower in metabolic cost and facilitates greater force production through multi-joint leg actions.  
Chapter 2 reports on an investigation that utilises an eccentric cycling ergometer to evaluate and observe the influence of eccentric cycle training on a range of key performance parameters, and physiological measures on a well-trained cycling population. Specifically, in this novel study we assessed the physiological performance measures of leg spring stiﬀness, 4 s mean maximal sprint power, 4-km time-trial performance, and economy prior to, during, and following periodised eccentric cycle training. The investigation recruited eight healthy well-trained male participants (mean ± SD; age: 33 ± 12 yr; mass: 80 ± 11 kg; VO₂peak: 64 ± 8 ml.kg⁻¹.min⁻¹) to take part in a 6 week, 12 session eccentric cycling study. Utilising a commercially available eccentric ergometer (Cyclus2, Leipzig, Germany), the participants replaced two hours of their weekly cycle training, with eccentric cycling. Initial training loads were prescribed based on 25% of participant 4 s mean maximal sprint power (MM4SP). Stepwise increases of training load occurred every 3ʳᵈ training session. Assessments of submaximal hopping to evaluate leg spring stiﬀness, 4 s mean maximal sprint power and 4-km time-trial performance were conducted, prior-to, during the 3ʳᵈ week (Mid), and 1 and 4 weeks following the eccentric cycling intervention. Over a 6 week period, this stepwise approach led to an increase in workload from 25% to 50% of participant MM4SP. Overall participants achieved 97 ± 4% of their individual prescribed training load during the 6 week eccentric cycling training intervention.  
Relative to baseline measures, muscle stiffness effects were very likely positive (35.8 ± 30.4%) at week 3 (Mid), and at 1 week post (57.7 ± 22.3 and 46.6 ± 26.0%) week 4 post intervention. Effects for 4 s mean maximal sprint power were likely beneficial at 60 rpm at week 11 relative to both baseline, and week 7. Similarly, likely beneficial effects were reported at 120 (week 7 – pre), and 135 rpm (week 11 – pre). 4-km time-trial performance, at Mid (mean ± SD %: 0.2 ± 2.8%), and 1 week (0.7 ± 2.3%) post-training produced unclear alterations, while likely beneficial improvements were seen at week 4 (2.3 ± 3.6%) post-training. The findings of the current study suggest that 12 sessions of eccentric training over a 6 week period improved 4-km time-trial performance, and muscle stiffness within a well-trained population. Outcomes for the remaining endurance and sprint performance related measures however predominantly resulted as unaltered or unclear over the participant population

text: The effect of eccentric cycle training on physiological and performance parameters in cycling. Prior research has demonstrated the benefits of 3 to 8 weeks of eccentric cycle  training in athletes, the elderly, and in suffers of various pathophysiological conditions. Eccentric cycling requires participants to absorb force generated by an electric motor that drives a traditional cycle crank in a reverse fashion. Relative to traditional concentric cycle training, eccentric cycling is lower in metabolic cost and facilitates greater force production through multi-joint leg actions.  
Chapter 2 reports on an investigation that utilises an eccentric cycling ergometer to evaluate and observe the influence of eccentric cycle training on a range of key performance parameters, and physiological measures on a well-trained cycling population. Specifically, in this novel study we assessed the physiological performance measures of leg spring stiﬀness, 4 s mean maximal sprint power, 4-km time-trial performance, and economy prior to, during, and following periodised eccentric cycle training. The investigation recruited eight healthy well-trained male participants (mean ± SD; age: 33 ± 12 yr; mass: 80 ± 11 kg; VO₂peak: 64 ± 8 ml.kg⁻¹.min⁻¹) to take part in a 6 week, 12 session eccentric cycling study. Utilising a commercially available eccentric ergometer (Cyclus2, Leipzig, Germany), the participants replaced two hours of their weekly cycle training, with eccentric cycling. Initial training loads were prescribed based on 25% of participant 4 s mean maximal sprint power (MM4SP). Stepwise increases of training load occurred every 3ʳᵈ training session. Assessments of submaximal hopping to evaluate leg spring stiﬀness, 4 s mean maximal sprint power and 4-km time-trial performance were conducted, prior-to, during the 3ʳᵈ week (Mid), and 1 and 4 weeks following the eccentric cycling intervention. Over a 6 week period, this stepwise approach led to an increase in workload from 25% to 50% of participant MM4SP. Overall participants achieved 97 ± 4% of their individual prescribed training load during the 6 week eccentric cycling training intervention.  
Relative to baseline measures, muscle stiffness effects were very likely positive (35.8 ± 30.4%) at week 3 (Mid), and at 1 week post (57.7 ± 22.3 and 46.6 ± 26.0%) week 4 post intervention. Effects for 4 s mean maximal sprint power were likely beneficial at 60 rpm at week 11 relative to both baseline, and week 7. Similarly, likely beneficial effects were reported at 120 (week 7 – pre), and 135 rpm (week 11 – pre). 4-km time-trial performance, at Mid (mean ± SD %: 0.2 ± 2.8%), and 1 week (0.7 ± 2.3%) post-training produced unclear alterations, while likely beneficial improvements were seen at week 4 (2.3 ± 3.6%) post-training. The findings of the current study suggest that 12 sessions of eccentric training over a 6 week period improved 4-km time-trial performance, and muscle stiffness within a well-trained population. Outcomes for the remaining endurance and sprint performance related measures however predominantly resulted as unaltered or unclear over the participant population

year: 2018

title: Outcomes in different ethnic groups of New Zealand patients with screen-detected vs. non-screen-detected breast cancer.

authors: Lawrenson, Ross

subjects: Breast screening

abstract: OBJECTIVE: To compare characteristics and survival of New Zealand European, Māori, and Pacific women with screen-detected vs. non-screen-detected breast cancer. 
METHODS: Women aged 45-69 diagnosed with invasive breast cancer between January 2005 and May 2013 were identified from the Waikato and Auckland Breast Cancer Registries. Patient demographics and tumour characteristics were described by detection mode and ethnicity. Kaplan-Meier method was used to estimate the five-year breast cancer-specific survival of women with stage I-III breast cancer by ethnicity and detection mode. 
RESULTS: Women with screen-detected cancers were older, had smaller tumours, fewer stage IV (0.8% vs. 7.6%), fewer high grade (16.8% vs. 39.0%), and fewer lymph node positive diseases (26.3% vs. 51.5%) than women with non-screen-detected cancers. There were more Luminal A (70.0% vs. 54.0%), fewer human epidermal growth factor receptor 2 positive non-Luminal (4.4% vs. 8.8%), and fewer triple negative cases (7.0% vs. 13.8%) in screen-detected than non-screen-detected cancers. If not screen detected, 22.7% of breast cancers in Pacific women were stage IV compared with 2.4% if screen detected. If not screen detected, the five-year breast cancer-specific survival was 91.1% for New Zealand European women, 84.2% for Māori women, and 80.2% for Pacific women (p-value <0.001). For screen-detected breast cancer, survival between different ethnic groups was similar.
CONCLUSIONS: Breast cancers detected through screening are diagnosed at an earlier stage and have a greater proportion of subtypes, with better outcome. Variations in survival for Māori and Pacific women are only found in women with non-screen-detected breast cancer.

text: Outcomes in different ethnic groups of New Zealand patients with screen-detected vs. non-screen-detected breast cancer. OBJECTIVE: To compare characteristics and survival of New Zealand European, Māori, and Pacific women with screen-detected vs. non-screen-detected breast cancer. 
METHODS: Women aged 45-69 diagnosed with invasive breast cancer between January 2005 and May 2013 were identified from the Waikato and Auckland Breast Cancer Registries. Patient demographics and tumour characteristics were described by detection mode and ethnicity. Kaplan-Meier method was used to estimate the five-year breast cancer-specific survival of women with stage I-III breast cancer by ethnicity and detection mode. 
RESULTS: Women with screen-detected cancers were older, had smaller tumours, fewer stage IV (0.8% vs. 7.6%), fewer high grade (16.8% vs. 39.0%), and fewer lymph node positive diseases (26.3% vs. 51.5%) than women with non-screen-detected cancers. There were more Luminal A (70.0% vs. 54.0%), fewer human epidermal growth factor receptor 2 positive non-Luminal (4.4% vs. 8.8%), and fewer triple negative cases (7.0% vs. 13.8%) in screen-detected than non-screen-detected cancers. If not screen detected, 22.7% of breast cancers in Pacific women were stage IV compared with 2.4% if screen detected. If not screen detected, the five-year breast cancer-specific survival was 91.1% for New Zealand European women, 84.2% for Māori women, and 80.2% for Pacific women (p-value <0.001). For screen-detected breast cancer, survival between different ethnic groups was similar.
CONCLUSIONS: Breast cancers detected through screening are diagnosed at an earlier stage and have a greater proportion of subtypes, with better outcome. Variations in survival for Māori and Pacific women are only found in women with non-screen-detected breast cancer.

year: 2019