title: The outcome and implications of public precautionary measures in Taiwan-declining respiratory disease cases in the COVID-19 pandemic.

authors: Hsieh, Chih-Chia

subjects: COVID-19

abstract: With the rapid development of the COVID-19 pandemic, countries are trying to cope with increasing medical demands, and, at the same time, to reduce the increase of infected numbers by implementing a number of public health measures, namely non-pharmaceutical interventions (NPIs). These public health measures can include social distancing, frequent handwashing, and personal protective equipment (PPE) at the personal level; at the community and the government level, these measures can range from canceling activities, avoiding mass gatherings, closing facilities, and, at the extreme, enacting national or provincial lockdowns. Rather than completely stopping the infectious disease, the major purpose of these NPIs in facing an emerging infectious disease is to reduce the contact rate within the population, and reduce the spread of the virus until the time a vaccine or reliable medications become available. The idea is to avoid a surge of patients with severe symptoms beyond the capacity of the hospitals' medical resources, which would lead to more mortality and morbidity. While many countries have experienced steep curves in new cases, some, including Hong Kong, Vietnam, South Korea, New Zealand, and Taiwan, seem to have controlled or even eliminated the infection locally. From its first case of COVID-19 on the 21 January until the 12 May, Taiwan had 440 cases, including just 55 local infections, and seven deaths in total, representing 1.85 cases per 100,000 population and a 1.5% death rate (based on the Worldometer 2020 statistics of Taiwan's population of 23.8 million). This paper presents evidence that spread prevention involving mass masking and universal hygiene at the early stage of the COVID-19 pandemic resulted in a 50% decline of infectious respiratory diseases, based on historical data during the influenza season in Taiwan. These outcomes provide potential support for the effectiveness of widely implementing public health precaution measures in controlling COVID-19 without a lockdown policy.

text: The outcome and implications of public precautionary measures in Taiwan-declining respiratory disease cases in the COVID-19 pandemic. With the rapid development of the COVID-19 pandemic, countries are trying to cope with increasing medical demands, and, at the same time, to reduce the increase of infected numbers by implementing a number of public health measures, namely non-pharmaceutical interventions (NPIs). These public health measures can include social distancing, frequent handwashing, and personal protective equipment (PPE) at the personal level; at the community and the government level, these measures can range from canceling activities, avoiding mass gatherings, closing facilities, and, at the extreme, enacting national or provincial lockdowns. Rather than completely stopping the infectious disease, the major purpose of these NPIs in facing an emerging infectious disease is to reduce the contact rate within the population, and reduce the spread of the virus until the time a vaccine or reliable medications become available. The idea is to avoid a surge of patients with severe symptoms beyond the capacity of the hospitals' medical resources, which would lead to more mortality and morbidity. While many countries have experienced steep curves in new cases, some, including Hong Kong, Vietnam, South Korea, New Zealand, and Taiwan, seem to have controlled or even eliminated the infection locally. From its first case of COVID-19 on the 21 January until the 12 May, Taiwan had 440 cases, including just 55 local infections, and seven deaths in total, representing 1.85 cases per 100,000 population and a 1.5% death rate (based on the Worldometer 2020 statistics of Taiwan's population of 23.8 million). This paper presents evidence that spread prevention involving mass masking and universal hygiene at the early stage of the COVID-19 pandemic resulted in a 50% decline of infectious respiratory diseases, based on historical data during the influenza season in Taiwan. These outcomes provide potential support for the effectiveness of widely implementing public health precaution measures in controlling COVID-19 without a lockdown policy.

year: 2020-07-06

title: Biophysical, environmental, and economic implications of removing imported supplementary feed from a pasture-based dairy farm system - An upper North Island case study

authors: McCahon, Kieran Shaun

subjects: Palm kernel expeller

abstract: The biological efficiency and profitability of pasture-based systems is optimised by matching pasture supply with the nutritional demands of the herd across the year. Despite the importance of grazed pasture to the profitability of pasture-based systems, the use of purchased (i.e., non-pasture) feeds (supplementary feeds) has increased considerably over the last two decades within the New Zealand (NZ) dairy industry. 
Supplementary feeds may be offered to maintain or increase dry matter intake (DMI) and milk production during periods when pasture supply is insufficient to meet herd demands (i.e., a pasture deficit). However, published results indicate that, despite greater milk production and gross farm revenue (GFR), imported supplementary feed is not associated with an increase in profitability. In addition, the intensification of grazing systems through concurrent increases in stocking rate (SR) have been associated with poorer environmental outcomes, such as reduced water quality and increased greenhouse gas (GHG) emissions. 
The primary objective of my Masters project was to investigate the biophysical, economic, and environmental effects of removing imported supplementary feed from a typical pasture-based system in the upper North Island of New Zealand. This was conducted over three years in Northland, New Zealand (35⁰56’39”S 173⁰50’34”E), using a quantitative case-study approach that compared three pasture-based dairy farming treatments differing in SR and the nature of feed supply. As a Control treatment, imported supplementary feed was offered as palm kernel expeller (PKE) during periods of pasture deficit (~ 550kg DM/cow/yr; ~ 10% of the cows’ diet; PKE treatment). This was compared with two alternative systems to remove the need for PKE: 1) reduced SR (Pasture treatment); or, 2) growing potentially high yielding forage crops on the dairy platform and maintaining SR (Cropping treatment). I used the nutrient budgeting software OVERSEER to model treatment effects on nitrogen (N) leaching, phosphorous (P) loss, and GHG emissions. In addition, I conducted a Monte Carlo analysis to investigate economic performance of all three treatments and how it varied over a range of key input prices.
On average, despite no significant difference in milk production, operating profit tended to be lower in the Cropping treatment relative to the PKE treatment. In addition, after accounting for variability in market prices, the Cropping treatment returned a lower operating profit at every probability level relative to the PKE treatment and was, therefore, an inferior system for a profit-focused decision maker.
Milk production and associated GFR were lower in the Pasture treatment compared with the PKE treatment; however, there was no effect of treatment on operating profit at average market prices. When accounting for potential market price variability, the PKE treatment returned a greater operating profit in 70% of scenarios. As a result, the PKE treatment would likely provide a preferable system for a profit-focused decision maker, with low to moderate risk aversion. However, the relative profitability of treatments was highly dependent on the marginal milk production response (MMPR) to supplementary feed. Consistently large MMPRs to supplementary feed were achieved in the current study: 30 to 50% greater than published farm systems experiments. A reduction in the MMPR to supplementary feed by 10% eroded the profit advantage of the PKE treatment. In addition, despite no treatment effect on N leaching, GHG emissions tended to be lower in the Pasture treatment relative to the PKE treatment. As a result, a decision maker, paying or receiving incentives to reduce environmental externalities would likely be indifferent between the PKE and Pasture treatments, even with the large MMPR to supplementary feed achieved in the current study. Depending on the potential response to supplementary feed, profitability may be maintained with the removal of imported supplementary feeds from a pasture based system by decreasing SR.

text: Biophysical, environmental, and economic implications of removing imported supplementary feed from a pasture-based dairy farm system - An upper North Island case study The biological efficiency and profitability of pasture-based systems is optimised by matching pasture supply with the nutritional demands of the herd across the year. Despite the importance of grazed pasture to the profitability of pasture-based systems, the use of purchased (i.e., non-pasture) feeds (supplementary feeds) has increased considerably over the last two decades within the New Zealand (NZ) dairy industry. 
Supplementary feeds may be offered to maintain or increase dry matter intake (DMI) and milk production during periods when pasture supply is insufficient to meet herd demands (i.e., a pasture deficit). However, published results indicate that, despite greater milk production and gross farm revenue (GFR), imported supplementary feed is not associated with an increase in profitability. In addition, the intensification of grazing systems through concurrent increases in stocking rate (SR) have been associated with poorer environmental outcomes, such as reduced water quality and increased greenhouse gas (GHG) emissions. 
The primary objective of my Masters project was to investigate the biophysical, economic, and environmental effects of removing imported supplementary feed from a typical pasture-based system in the upper North Island of New Zealand. This was conducted over three years in Northland, New Zealand (35⁰56’39”S 173⁰50’34”E), using a quantitative case-study approach that compared three pasture-based dairy farming treatments differing in SR and the nature of feed supply. As a Control treatment, imported supplementary feed was offered as palm kernel expeller (PKE) during periods of pasture deficit (~ 550kg DM/cow/yr; ~ 10% of the cows’ diet; PKE treatment). This was compared with two alternative systems to remove the need for PKE: 1) reduced SR (Pasture treatment); or, 2) growing potentially high yielding forage crops on the dairy platform and maintaining SR (Cropping treatment). I used the nutrient budgeting software OVERSEER to model treatment effects on nitrogen (N) leaching, phosphorous (P) loss, and GHG emissions. In addition, I conducted a Monte Carlo analysis to investigate economic performance of all three treatments and how it varied over a range of key input prices.
On average, despite no significant difference in milk production, operating profit tended to be lower in the Cropping treatment relative to the PKE treatment. In addition, after accounting for variability in market prices, the Cropping treatment returned a lower operating profit at every probability level relative to the PKE treatment and was, therefore, an inferior system for a profit-focused decision maker.
Milk production and associated GFR were lower in the Pasture treatment compared with the PKE treatment; however, there was no effect of treatment on operating profit at average market prices. When accounting for potential market price variability, the PKE treatment returned a greater operating profit in 70% of scenarios. As a result, the PKE treatment would likely provide a preferable system for a profit-focused decision maker, with low to moderate risk aversion. However, the relative profitability of treatments was highly dependent on the marginal milk production response (MMPR) to supplementary feed. Consistently large MMPRs to supplementary feed were achieved in the current study: 30 to 50% greater than published farm systems experiments. A reduction in the MMPR to supplementary feed by 10% eroded the profit advantage of the PKE treatment. In addition, despite no treatment effect on N leaching, GHG emissions tended to be lower in the Pasture treatment relative to the PKE treatment. As a result, a decision maker, paying or receiving incentives to reduce environmental externalities would likely be indifferent between the PKE and Pasture treatments, even with the large MMPR to supplementary feed achieved in the current study. Depending on the potential response to supplementary feed, profitability may be maintained with the removal of imported supplementary feeds from a pasture based system by decreasing SR.

year: 2019

title: Boat electrofishing survey of fish abundance in the Ohau Channel, Rotorua, in 2015

authors: Hicks, Brendan J.

abstract: The aim of the survey was to provide on-going monitoring of the fish communities and abundance by boat electrofishing in the Ohau Channel, especially fish species that are taonga to Maori (eels, goldfish, and koura). In the current study, we present the findings from the ninth year of sampling (2015) and a summary of previous surveys.
We used the University of Waikato's 4.5 m-long, aluminium-hulled electrofishing boat to catch a total of total of 1,198 fish and koura (18.9 kg) at 13 sites on 2 December 2015, which comprised 2,671 lineal m and 10,684 m² in area. Koura (freshwater crayfish) and 6 fish species were present, with common bully the most abundant species (up to 45.5 fish 100 m⁻² at the site 6, edge habitat). Goldfish (up to 4.85 100 m⁻²) was the next most abundant species, with most goldfish at sites 7 and 12-13 in and around the side channel. Rainbow trout densities were up to 0.28 fish 100 m⁻². Mean bully density (11.41 fish 100 m⁻²) was much higher than for smelt (0.29 fish 100 m⁻²). Koura had a patchy distribution; only 3 individuals were caught at one site.
Comparing catches over the 9 years of sampling, the mean abundance of common bullies in 2015 was consistent with densities in most post-wall years (after 2007), but lower than in 2007 before wall closure (ANOVA P = 0.001). The cause of fluctuating bully abundance is not known, and was not accounted for by changes in water clarity expressed as black disc distance (BDD), water temperature, or water conductivity. Poor water clarity can reduce the efficiency of electrofishing, but high BDD did not correspond with high common bully densities. In 2015, smelt abundance had recovered somewhat from the low catch in 2014.
Goldfish biomass increased initially (2009-2010) because of targeted fishing in the excavated side branch (site 11), which has dense macrophytes and offers good habitat for goldfish. The continued rise in density from 2012 on, however, suggests a real increase in goldfish numbers. In 2012 and 2013 shortfin eels were caught, but no eels were caught in 2014 and only a single longfin eel was caught in 2015.
Analysis of fish densities before and after wall closure is hampered by the single data point before closure. However, we now have 9 years of post-wall data, and comparison of means suggest that the number of bullies has been lower since 2007. An obvious cause could be interruption of bully migration into the Ohau Channel from Lake Rotoiti by the wall. This suggests that the bully population in the Ohau Channel before wall construction and closure was a mixture of fish from lakes Rotorua and Rotoiti, and that recruitment from Rotoiti is now restricted. This hypothesis is testable with otolith microchemistry.

text: Boat electrofishing survey of fish abundance in the Ohau Channel, Rotorua, in 2015 The aim of the survey was to provide on-going monitoring of the fish communities and abundance by boat electrofishing in the Ohau Channel, especially fish species that are taonga to Maori (eels, goldfish, and koura). In the current study, we present the findings from the ninth year of sampling (2015) and a summary of previous surveys.
We used the University of Waikato's 4.5 m-long, aluminium-hulled electrofishing boat to catch a total of total of 1,198 fish and koura (18.9 kg) at 13 sites on 2 December 2015, which comprised 2,671 lineal m and 10,684 m² in area. Koura (freshwater crayfish) and 6 fish species were present, with common bully the most abundant species (up to 45.5 fish 100 m⁻² at the site 6, edge habitat). Goldfish (up to 4.85 100 m⁻²) was the next most abundant species, with most goldfish at sites 7 and 12-13 in and around the side channel. Rainbow trout densities were up to 0.28 fish 100 m⁻². Mean bully density (11.41 fish 100 m⁻²) was much higher than for smelt (0.29 fish 100 m⁻²). Koura had a patchy distribution; only 3 individuals were caught at one site.
Comparing catches over the 9 years of sampling, the mean abundance of common bullies in 2015 was consistent with densities in most post-wall years (after 2007), but lower than in 2007 before wall closure (ANOVA P = 0.001). The cause of fluctuating bully abundance is not known, and was not accounted for by changes in water clarity expressed as black disc distance (BDD), water temperature, or water conductivity. Poor water clarity can reduce the efficiency of electrofishing, but high BDD did not correspond with high common bully densities. In 2015, smelt abundance had recovered somewhat from the low catch in 2014.
Goldfish biomass increased initially (2009-2010) because of targeted fishing in the excavated side branch (site 11), which has dense macrophytes and offers good habitat for goldfish. The continued rise in density from 2012 on, however, suggests a real increase in goldfish numbers. In 2012 and 2013 shortfin eels were caught, but no eels were caught in 2014 and only a single longfin eel was caught in 2015.
Analysis of fish densities before and after wall closure is hampered by the single data point before closure. However, we now have 9 years of post-wall data, and comparison of means suggest that the number of bullies has been lower since 2007. An obvious cause could be interruption of bully migration into the Ohau Channel from Lake Rotoiti by the wall. This suggests that the bully population in the Ohau Channel before wall construction and closure was a mixture of fish from lakes Rotorua and Rotoiti, and that recruitment from Rotoiti is now restricted. This hypothesis is testable with otolith microchemistry.

year: 2016