High-gradient normal-conducting RF structures for muon cooling channels

We present a status report on the research and development of high-gradient normal-conducting RF structures for the ionization cooling of muons in a neutrino factory or muon collider. High-gradient RF structures are required in regions enclosed in strong focusing solenoidal magnets, precluding the application of superconducting RF technology [1]. We propose using linear accelerating structures, with individual cells electromagnetically isolated, to achieve the required gradients of over 15 MV/m at 201 MHz and 30 MV/m at 805 MHz. Each cell will be powered independently, and cell length and drive phase adjusted to optimize shunt impedance of the assembled structure. This efficient design allows for relatively small field enhancement on the structure walls, and an accelerating field approximately 1.7 times greater than the peak surface field. The electromagnetic boundary of each cell may be provided by a thin Be sheet, or an assembly of thin-walled metal tubes. Use of thin, low-Z materials will allow passage of the muon beams without significant deterioration in beam quality due to scattering. R and D in design and analysis of robust structures that will operate under large electric and magnetic fields and RF current heating are discussed, including the experimental program based in a high-power test laboratory developed for this purpose

Integrating sequence and array data to create an improved 1000 Genomes Project haplotype reference panel

A major use of the 1000 Genomes Project (1000GP) data is genotype imputation in genome-wide association studies (GWAS). Here we develop a method to estimate haplotypes from low-coverage sequencing data that can take advantage of single-nucleotide polymorphism (SNP) microarray genotypes on the same samples. First the SNP array data are phased to build a backbone (or 'scaffold') of haplotypes across each chromosome. We then phase the sequence data 'onto' this haplotype scaffold. This approach can take advantage of relatedness between sequenced and non-sequenced samples to improve accuracy. We use this method to create a new 1000GP haplotype reference set for use by the human genetic community. Using a set of validation genotypes at SNP and bi-allelic indels we show that these haplotypes have lower genotype discordance and improved imputation performance into downstream GWAS samples, especially at low-frequency variants. © 2014 Macmillan Publishers Limited. All rights reserved

Global data set of long-term summertime vertical temperature profiles in 153 lakes

peer reviewedClimate change and other anthropogenic stressors have led to long-term changes in the thermal structure, including surface temperatures, deepwater temperatures, and vertical thermal gradients, in many lakes around the world. Though many studies highlight warming of surface water temperatures in lakes worldwide, less is known about long-term trends in full vertical thermal structure and deepwater temperatures, which have been changing less consistently in both direction and magnitude. Here, we present a globally-expansive data set of summertime in-situ vertical temperature profiles from 153 lakes, with one time series beginning as early as 1894. We also compiled lake geographic, morphometric, and water quality variables that can influence vertical thermal structure through a variety of potential mechanisms in these lakes. These long-term time series of vertical temperature profiles and corresponding lake characteristics serve as valuable data to help understand changes and drivers of lake thermal structure in a time of rapid global and ecological change. © 2021, The Author(s)

Survival of stocked barramundi, Lates calcarifer (Bloch), in a coastal river system in far northern Queensland, Australia

As part of an ongoing study to investigate the efficacy and cost-benefit ratio of stock enhancement of barramundi, Lates calcarifer (Bloch), in coastal river systems, about 69,000 fingerlings have been released into the Johnstone River in northern Queensland, Australia, since 1993. All stocked barramundi were marked with coded wire tags to allow their discrimination from naturally recruited fish and to allow subsequent determination of fish size, release site, and release year class. The initial experimental design used two size classes of fish (30–40 mm and 50–60 mm total length), which were released into freshwater, estuarine and upper tidal habitats. The stocked barramundi took about three years to reach the minimum legal size of 580 mm total length. Stocked fish comprised about 20% of barramundi from the relevant size classes in research catches. No significant difference was found in the numbers of fish returned from the two different stocking size classes. Most stocked fish (62%) were recaptured within 3 km of their release site, but 38% undertook intrariverine movements of up to 37 km. Angler record cards and commercial catch data are being used in an effort to detect measurable increases in catch per unit effort in the recreational and commercial fishery sectors. Cost-benefit analysis indicates that less than 1% of stocked barramundi need to be recaptured to cover the costs of the stocking program

Importance of Release Habitat for Survival of Stocked Barramundi in Northern Australia

Barramundi Lates calcarifer is a large, euryhaline, catadromous centropomid found throughout much of the Indo-West Pacific, including northern Australia where it is highly sought after as a sport, recreational, and commercial species. It also supports a growing aquaculture industry, and it was the successful development of technology for the large-scale production of this species that prompted interest in stock enhancement. There is evidence that the recreational and commercial fisheries are in decline (Rimmer and Russell 1998), and stock enhancement is perceived as one of a number of management tools that could be used to address this issue. Stock enhancement programs in Queensland coastal rivers have been under way since the early 1990s. Additionally, new put-and-take recreational fisheries for barramundi have been created in freshwater impoundments using hatchery-reared barramundi. Since 1992, the Queensland Department of Primary Industries (DPI) has released more than 120,000 hatchery-reared juvenile barramundi as small as 30 mm total length (TL) into the Johnstone River in northeastern Australia, as part of an experimental stock-enhancement program. Stocked fish take between three to four years before they are recruited into the fishery but now make up about 19% and 13% of the recreational and commercial catches, respectively (Russell and Rimmer 1997; Rimmer and Russell 1998). The study also provided useful information on barramundi movements. Most (62%) stocked fish, particularly juveniles, were recaptured within 3 km of their release location, and 37% made intra-riverine movements of between 3 and 37 km. Five fish made inter-riverine or coastal movements (Russell and Rimmer 1997; Rimmer and Russell 1998)

Physiological responses of the Asian Sea Bass, Lates calcarifer to water quality deterioration during simulated live transport: acidosis, red-cell swelling, and levels of ions and ammonia in the plasma

Water is a major expense when air-freighting live fish. However, reducing the volume of water relative to the amount of product usually results in more rapid water quality deterioration and higher mortality due to the higher concentration of excretory products in closed transport systems. The major water quality effects experienced by fish during transport are: low dissolved oxygen levels due to oxygen consumption by respiration; accumulation of carbon dioxide from respiration; depression of pH caused by carbon dioxide accumulation; and increased ammonia levels resulting from ammonia excretion. The physiological responses of seawater-adapted barramundi, Lates calcarifer, were studied during simulated live transport and transport under circumstances of elevated CO2 or NH3. Blood samples were removed from fish exposed to these treatments and compared to samples from control fish, (free in the tank) and fish confined in a box but with free-flowing seawater. Analysing the blood samples showed that simulated transport caused the plasma pH of the fish to fall, threatening the blood's ability to transport oxygen, but the red blood cells apparently defended their internal pH and oxygen transport capacity, and swelled measurably as a result. Exposing fish to unusually high carbon dioxide or ammonia levels caused plasma pH to fall to near lethal levels. The effects of both carbon dioxide and ammonia need to be considered when studying the responses of barramundi to live transport. Water quality parameters during fish transport do not act in isolation. Attempts to reduce carbon dioxide accumulation, for example, by using a buffer to control the water pH, may influence the fish's ability to excrete ammonia

Physiological responses of the Asian Sea Bass, Lates calcarifer to water quality deterioration during simulated live transport: acidosis, red-cell swelling, and levels of ions and ammonia in the plasma

Water is a major expense when air-freighting live fish. However, reducing the volume of water relative to the amount of product usually results in more rapid water quality deterioration and higher mortality due to the higher concentration of excretory products in closed transport systems. The major water quality effects experienced by fish during transport are: low dissolved oxygen levels due to oxygen consumption by respiration; accumulation of carbon dioxide from respiration; depression of pH caused by carbon dioxide accumulation; and increased ammonia levels resulting from ammonia excretion. The physiological responses of seawater-adapted barramundi, Lates calcarifer, were studied during simulated live transport and transport under circumstances of elevated CO2 or NH3. Blood samples were removed from fish exposed to these treatments and compared to samples from control fish, (free in the tank) and fish confined in a box but with free-flowing seawater. Analysing the blood samples showed that simulated transport caused the plasma pH of the fish to fall, threatening the blood's ability to transport oxygen, but the red blood cells apparently defended their internal pH and oxygen transport capacity, and swelled measurably as a result. Exposing fish to unusually high carbon dioxide or ammonia levels caused plasma pH to fall to near lethal levels. The effects of both carbon dioxide and ammonia need to be considered when studying the responses of barramundi to live transport. Water quality parameters during fish transport do not act in isolation. Attempts to reduce carbon dioxide accumulation, for example, by using a buffer to control the water pH, may influence the fish's ability to excrete ammonia

International human rights law – lessons in the era of COVID-19

The COVID-19 pandemic has brought the connections between law and public health into stark relief. The pandemic has demonstrated both the essential nature of global cooperation and international regulation to promote universal rights to life and health, and the potentially harmful impacts of limitations imposed on human rights in time of emergency. It has also tested the international human rights framework, which allows for permissible limitations on human rights where required, but which remains subject to widely varying domestic implementation. In this paper, we explore the relationship between international human rights law and the COVID-19 pandemic, including a focus on the rights of vulnerable individuals and communities who have experienced disproportionate impacts from both the pandemic itself and from measures that constrain the exercise of human rights. We propose that the inquiry and monitoring mechanisms of the UN human rights bodies provide important avenues for addressing the human rights implications of COVID-19 and Government responses to the pandemic. We also review Australia’s domestic implementation of international human rights law and its relevance in the era of COVID-19, noting the piecemeal approach to human rights protection under Australian law. We conclude that this time of emergency provides an opportunity for the progressive development of international human rights law, via principles of reciprocity, social protection, human rights preparedness and comprehensive normative protection for a right to public health

The potential of tropical paracalanid copepods as live feeds in aquaculture

The small calanoid copepods Bestiolina similis and Parvocalanus crassirostris (Paracalanidae) are compared to Acartia sinjiensis, a species of the copepod genus most commonly cultured to provide larval diets for tropical snappers and groupers. All species are easily maintained in culture, though cultures of Acartia spp. are easier to establish because of the positive phototactic behaviour of this genus. B. similis and P. crassirostris are smaller than A. sinjiensis, and consequently, their developmental\ud stages are more suited to larval fish requiring small prey items. In addition, siphon-avoidance experiments indicated that adults of these species were more vulnerable to predation, though this was not the case for juvenile copepods. Egg production was maximised with larger algal cells, especially Rhodomonas sp. and Heterocapsa niei: B. similis fed H. niei achieved the highest egg production rates (48 eggs female 1 day 1). Lipid composition of all species was low and variable (11–26 mg g 1) under our culture conditions, in contrast to results from temperate copepod species or from wild-caught copepods. All three species studied had DHA/EPA/ARA ratios that met or exceeded those recommended for marine larval fish feeds (DHA/EPA/ARA-14:3:1, 20:9:1 and 25:6:1 for A. sinjiensis, P. crassirostris and B. similis, respectively). On the basis of size of developmental stages, susceptibility to\ud predation, growth rate and nutritional composition, B. similis was the best candidate for larval fish diets.\u