Differentiation of human and calf isolates of Giardia intestinalis : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Microbiology at Massey University

Traditionally farm runoff has been blamed for the contamination of aquatic waterways with Giardia cysts especially during the natural calving seasons. But despite Giardia intestinalis being one of the most commonly acquired waterborne gastrointestinal parasites in humans little is known about the extent of G.intestinalis transmission between humans and animals throughout a defined geographical region, This study examines the characterisation of human, calf and laboratory adapted isolates of G.intestinalis. Specific amplification primers were developed to target a section of the ribosomal DNA (rDNA) unit. This locus is considered to be rapidly evolving and therefore suitable for use in the elucidation of phylogenetic relationships between G.intestinalis isolates. The isolates characterised were collected in the Waikato district from naturally infected humans and calves throughout 1998 but especially during the spring calving season of August and September. Giardia from calves from a second province as well as laboratory adapted isolates cultured from a variety of hosts were also surveyed. Sequence analysis of human, calf and laboratory adapted G.intestinalis isolates showed the presence of three distinct groups. All calf G.intestinalis isolates clustered together despite differences in the collection time and site. The human G.intestinalis isolates split into two clusters, corresponding to recognised 'Polish' and 'Belgian' subtypes. Surprisingly the laboratory adapted isolates grouped with the human 'polish' subtype despite striking differences in isolate origin. The current data strongly suggests that host specific G.intestinalis strains are present in the environment. Cross-transmission has so far not been detected. The occurrence of isolate specific rDNA sequences enabled the development of diagnostic polymerase chain reaction (PCR) amplification primers. In conjunction with the existing primers these allow the identification of human specific Giardia as well as differentiating between the 'Belgian' and 'polish' subtypes. These primers offer the ability to quickly and economically identify potential sources of human giardiasis in the environment. Using such molecular tools may lead to an overall decrease in human giardiasis resulting from environmental contamination sources

Proving Differential Privacy with Shadow Execution

Recent work on formal verification of differential privacy shows a trend toward usability and expressiveness -- generating a correctness proof of sophisticated algorithm while minimizing the annotation burden on programmers. Sometimes, combining those two requires substantial changes to program logics: one recent paper is able to verify Report Noisy Max automatically, but it involves a complex verification system using customized program logics and verifiers. In this paper, we propose a new proof technique, called shadow execution, and embed it into a language called ShadowDP. ShadowDP uses shadow execution to generate proofs of differential privacy with very few programmer annotations and without relying on customized logics and verifiers. In addition to verifying Report Noisy Max, we show that it can verify a new variant of Sparse Vector that reports the gap between some noisy query answers and the noisy threshold. Moreover, ShadowDP reduces the complexity of verification: for all of the algorithms we have evaluated, type checking and verification in total takes at most 3 seconds, while prior work takes minutes on the same algorithms.Comment: 23 pages, 12 figures, PLDI'1

SAMBA: Superconducting antenna-coupled, multi-frequency, bolometric array

We present a design for a multipixel, multiband (100 GHz, 200 GHz and 400 GHz) submillimeter instrument: SAMBA (Superconducting Antenna-coupled, Multi-frequency, Bolometric Array). SAMBA uses slot antenna coupled bolometers and microstrip filters. The concept allows for a much more compact, multiband imager compared to a comparable feedhorn-coupled bolometric system. SAMBA incorporates an array of slot antennas, superconducting transmission lines, a wide band multiplexer and superconducting transition edge bolometers. The transition-edge film measures the millimeter-wave power deposited in the resistor that terminates the transmission line

Assessing ballast treatment standards for effect on rate of establishment using a stochastic model of the green crab

This paper describes a stochastic model used to characterize the probability/risk of NIS establishment from ships' ballast water discharges. Establishment is defined as the existence of a sufficient number of individuals of a species to provide for a sustained population of the organism. The inherent variability in population dynamics of organisms in their native or established environments is generally difficult to quantify. Muchqualitative information is known about organism life cycles and biotic and abiotic environmental pressures on the population, but generally little quantitative data exist to develop a mechanistic model of populations in such complex environments. Moreover, there is little quantitative data to characterize the stochastic fluctuations of population size over time even without accounting for systematic responses to biotic and abiotic pressures. This research applies an approach using life-stage density and fecundity measures reported in research to determine a stochastic model of an organism's population dynamics. The model is illustrated withdata from research studies on the green crab that span a range of habitats of the established organism and were collected over some years to represent a range of time-varying biotic and abiotic conditions that are expected to exist in many receiving environments. This model is applied to introductions of NIS at the IMO D-2 and the U.S. ballast water discharge standard levels designated as Phase Two in the United States Coast Guard'sNotice of Proposed Rulemaking. Under a representative range of ballast volumes discharged at U.S. ports, the average rate of establishment of green crabs for ballast waters treated to the IMO-D2 concentration standard (less than 10 organisms/m3) is predicted to be reduced to about a third the average rate from untreated ballast water discharge. The longevity of populations from the untreated ballast water discharges is expected to be reducedby about 90% by treatment to the IMO-D2 concentration standard

Integrated Focal Plane Arrays for Millimeter-wave Astronomy

We are developing focal plane arrays of bolometric detectors for sub-millimeter and millimeter-wave astrophysics. We propose a flexible array architecture using arrays of slot antennae coupled via low-loss superconducting Nb transmission line to microstrip filters and antenna-coupled bolometers. By combining imaging and filtering functions with transmission line, we are able to realize unique structures such as a multi-band polarimeter and a planar, dispersive spectrometer. Micro-strip bolometers have significantly smaller active volume than standard detectors with extended absorbers, and can realize higher sensitivity and speed of response. The integrated array has natural immunity to stray radiation or spectral leaks, and minimizes the suspended mass operating at 0.1 - 0.3 K. We also discuss future space-borne spectroscopy and polarimetry applications

A Mediterranean undercurrent seeding experiment (AMUSE) : part II: RAFOS float data report, May 1993-March 1995

This is the final data report of all acoustically tracked RAFOS data collected in 1993-1995 during A Mediterranean Undercurrent Seeding Experiment (AMUSE). The overall objective of the program was to observe directly the spreading pathways by which Mediterranean Water enters the North Atlantic. This includes the direct observation of Mediterranean eddies (meddies), which is one mechanism that transports Mediterranean Water to the North Atlantic. The experiment was comprised of a repeated high-resolution expendable bathythermograph (XBT) section and RAFOS float deployments across the Mediterranean Undercurrent south of Portugal near 8.5°W. A total of 49 floats were deployed at a rate of about two floats per week on 23 cruises on the chartered Portuguese-based vessel, Kialoa II, and one cruise on the R/V Endeavor. The floats were ballasted for 1100 or 1200 decibars (db) to seed the lower salinity core of the Mediterranean Undercurrent. The objectives of the Lagrangian float study were (1) to identify where meddies form, (2) to make the first direct estimate of meddy formation frequency, (3) to estimate the fraction of time meddies are being formed, and (4) to determine the pathways by which Mediterranean Water which is not trapped in meddies enters the North Atlantic.Funding was provided by the National Science Foundation through Grant No. OCE-91-01033 to the Woods Hole Oceanographic Institution and Grant No. OCE-91-00724 to Scripps Institution of Oceanography, and by the Luso-American Foundation for Development through Grant No. 54/93 to the University of Lisbon

Moving on : the challenges for foreign language learning on transition from primary to secondary school

Europe's commitment to language learning has resulted in higher percentages of pupils studying foreign languages during primary education. In England, recent policy decisions to expand foreign language learning at primary level by 2010 create major implications for transition to secondary. This paper presents findings on transition issues from case studies of a DfES-funded project evaluating 19 local authority Pathfinders piloting the introduction of foreign language learning at primary level. Research on transition in other countries sets these findings in context. Finally, it investigates the challenges England faces for transition in the light of this expansion and discusses future implications

Design of broadband filters and antennas for SAMBA

We present a design for multipixel, multiband submillimeter instrument: SAMBA (Superconducting Antenna-coupled, Multi-frequency, Bolometric Array). SAMBA uses antenna coupled bolometers and microstrip filters. The concept allows for a much more compact, multiband imager compared to a comparable feedhorn-coupled bolometric system. SAMBA incorporates an array of slot antennas, superconducting transmission lines, a wide band multiplexer and superconducting transition edge bolometers. The transition-edge film measures the millimeter-wave power deposited in the resistor that terminates the transmission line

Transition-edge superconducting antenna-coupled bolometer

We report test results for a single pixel antenna-coupled bolometric detector. Our device consists of a dual slot microstrip antenna coupled to an Al/Ti/Au voltage-biased transition edge superconducting bolometer (TES). The coupling architecture involves propagating the signal along superconducting microstrip lines and terminating the lines at a normal metal resistor colocated with a TES on a thermally isolated island. The device, which is inherently polarization sensitive, is optimized for 140 GHz band measurements. In the thermal bandwidth of the TES, we measure a noise equivalent power of 2.0 × 10^(-17) W/√Hz in dark tests that agrees with calculated NEP including only contributions from thermal, Johnson and amplifier noise. We do not measure any excess noise at frequencies between 1 and 200 Hz. We measure a thermal conductance G ~5.5 × 10^(-11) W/K. We measure a thermal time constant as low as 437μs at 3μV bias when stimulating the TES directly using an LED