title: Urban planning provides potential for lake restoration through catchment re-vegetation

authors: Duggan, Ian C.

subjects: Oligotrophication

abstract: Encroachment of urban areas into forest and farmland is typically considered to have detrimental effects on terrestrial and aquatic ecosystems. Most restoration strategies for lakes affected by urban development represent expensive short-term fixes requiring on-going management, with long-term restoration requiring external nutrient inputs (typically the major impact of urban development) to be significantly reduced. This study details, using a simple nutrient budget, the effects of the conversion of farmland to native forest in a lake catchment (Waiwhakareke/Horseshoe Lake in the Waiwhakareke Natural Heritage Park (WHNP), New Zealand) during urban encroachment. I show how far-sighted planning employed by management authorities can lead to urban growth being beneficial to aquatic systems. Even using this method, however, managers should not expect lakes to become immediately available as amenities. Although reduction in external nutrient loads brought about by the reforestation of lake catchments in urban areas will ultimately lead to phosphorus reduction and concomitant water quality improvements, such responses may take a number of years due a continued release of nutrients from bottom sediments if they are initially within rural catchments. Urban management authorities therefore need to possess a long-term outlook and commitment to such projects. Overall, the WHNP project acts as a model for future urban development and spread of cities, providing opportunities for the long-term restoration and conservation of lakes.

text: Urban planning provides potential for lake restoration through catchment re-vegetation Encroachment of urban areas into forest and farmland is typically considered to have detrimental effects on terrestrial and aquatic ecosystems. Most restoration strategies for lakes affected by urban development represent expensive short-term fixes requiring on-going management, with long-term restoration requiring external nutrient inputs (typically the major impact of urban development) to be significantly reduced. This study details, using a simple nutrient budget, the effects of the conversion of farmland to native forest in a lake catchment (Waiwhakareke/Horseshoe Lake in the Waiwhakareke Natural Heritage Park (WHNP), New Zealand) during urban encroachment. I show how far-sighted planning employed by management authorities can lead to urban growth being beneficial to aquatic systems. Even using this method, however, managers should not expect lakes to become immediately available as amenities. Although reduction in external nutrient loads brought about by the reforestation of lake catchments in urban areas will ultimately lead to phosphorus reduction and concomitant water quality improvements, such responses may take a number of years due a continued release of nutrients from bottom sediments if they are initially within rural catchments. Urban management authorities therefore need to possess a long-term outlook and commitment to such projects. Overall, the WHNP project acts as a model for future urban development and spread of cities, providing opportunities for the long-term restoration and conservation of lakes.

year: 2012

title: Low-cost fluid flow sensor to enable electronic control of fractional distillation columns

authors: Scott, Jonathan B.

subjects: sensors

abstract: A sensor is described that measures fluid flow up to 20 ml/minute, and down to 0.001 ml/minute. The measurement involves counting drips as they fall through a pair of optical beams. The beams are formed using a pair of ordinary optical proximity sensors arranged to face each other so that each photo- receiver sees the other sensor’s emitter. The beams operate at two different frequencies so as to prevent reflected signals interfering. Only two sensors, an 8-pin microcontroller, and four resistors are required for the sensing. Calibration for a specific fluid is straightforward. An ethanol-water mixture produces 16 drips/ml, significantly different from the default pharmaceutical value of 12 drips/ml.

text: Low-cost fluid flow sensor to enable electronic control of fractional distillation columns A sensor is described that measures fluid flow up to 20 ml/minute, and down to 0.001 ml/minute. The measurement involves counting drips as they fall through a pair of optical beams. The beams are formed using a pair of ordinary optical proximity sensors arranged to face each other so that each photo- receiver sees the other sensor’s emitter. The beams operate at two different frequencies so as to prevent reflected signals interfering. Only two sensors, an 8-pin microcontroller, and four resistors are required for the sensing. Calibration for a specific fluid is straightforward. An ethanol-water mixture produces 16 drips/ml, significantly different from the default pharmaceutical value of 12 drips/ml.

year: 2021

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