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To achieve the elimination of the hepatitis C virus (HCV), sustained and sufficient levels of HCV testing is critical. The purpose of this study was to assess trends in testing and evaluate the effectiveness of strategies to diagnose people living with HCV. Data were from 12 primary care clinics in Victoria, Australia, that provide targeted services to people who inject drugs (PWID), alongside general health care. This ecological study spanned 2009–2019 and included analyses of trends in annual numbers of HCV antibody tests among individuals with no previous positive HCV antibody test recorded and annual test yield (positive HCV antibody tests/all HCV antibody tests). Generalised linear models estimated the association between count outcomes (HCV antibody tests and positive HCV antibody tests) and time, and χ2 test assessed the trend in test yield. A total of 44 889 HCV antibody tests were conducted 2009–2019; test numbers increased 6% annually on average [95% confidence interval (CI) 4–9]. Test yield declined from 2009 (21%) to 2019 (9%) (χ2P = <0.01). In more recent years (2013–2019) annual test yield remained relatively stable. Modest increases in HCV antibody testing and stable but high test yield within clinics delivering services to PWID highlights testing strategies are resulting in people are being diagnosed however further increases in the testing of people at risk of HCV or living with HCV may be needed to reach Australia's HCV elimination goals.
The chapter discusses the scientific and pragmatic challenges to be addressed when planning a study of cognitive psychopathology in children. The quasi-experimental nature of this branch of inquiry necessitates careful consideration of the sampling frame, as well as decisions on how to validly and efficiently measure psychopathology. The design should focus on maximizing the internal validity of the cognitive construct, experimental manipulation, and outcome variables. However, the ultimate significance of a study is also directly related its relevance to real world behaviors of interest. Pragmatic solutions to establishing effective recruitment strategies as well as methods to train research assistants and maintain active assent among child participants with emotional and behavioral concerns are also discussed.
We show that a dense subset of a sufficiently large group multiplication table contains either a large part of the addition table of the integers modulo some k, or the entire multiplication table of a certain large abelian group, as a subgrid. As a consequence, we show that triples systems coming from a finite group contain configurations with t triples spanning
$ O(\sqrt t )$
vertices, which is the best possible up to the implied constant. We confirm that for all t we can find a collection of t triples spanning at most t + 3 vertices, resolving the Brown–Erdős–Sós conjecture in this context. The proof applies well-known arithmetic results including the multidimensional versions of Szemerédi’s theorem and the density Hales–Jewett theorem.
This result was discovered simultaneously and independently by Nenadov, Sudakov and Tyomkyn , and a weaker result avoiding the arithmetic machinery was obtained independently by Wong .
Some firms use hidden knowledge facilitators (HKFs) to facilitate knowledge sharing among employees within intrafirm online communities. These firms hope for enhanced knowledge sharing outcomes within their organizations without letting employees know that HKFs exist. Yet, the extent to which HKFs’ interventions are effective remains unknown to researchers and managers. Built on the knowledge sharing (KS) literature, this study explores the unique roles of HKFs as moderators between a company and its employees. We develop several hypotheses to test the impact of the quantity and quality of HKFs’ online interventions on several KS outcomes. By analyzing log data of a Chinese corporation's online R&D community, we find that (1) the quantity of HKFs’ intervention has a mostly positive impact on KS outcomes; (2) the quality of HKFs’ intervention has a mixed impact on several KS outcomes, depending on which aspect of quantity is considered; and (3) the quality of HKFs’ intervention also moderates the positive impact of the quantity of HKFs’ intervention in different ways on different intended KS outcomes. This study makes a clear contribution to the literature on knowledge sharing and knowledge facilitation by demonstrating the impact of HKFs on KS outcomes in a Chinese context.
We construct longitudinal data from U.S. census records to study the economics of the Dust Bowl migration of the 1930s. Most of our findings contradict long-standing perceptions. While migration rates were high relative to elsewhere in the United States, they were similar to migration rates from the region in the 1920s. Relative to other occupations, farmers were the least likely to move. Furthermore, migrants from the Dust Bowl were not exceptionally likely to move to California. Finally, there was negligible migrant selectivity, and migration was not associated with long-lasting negative labor market outcomes; indeed, for farmers, the gains from migration were positive.
This paper summarises developments in understanding sea level change during the Quaternary in Scotland since the publication of the Quaternary of Scotland Geological Conservation Review volume in 1993. We present a review of progress in methodology, particularly in the study of sediments in isolation basins and estuaries as well as in techniques in the field and laboratory, which have together disclosed greater detail in the record of relative sea level (RSL) change than was available in 1993. However, progress in determining the record of RSL change varies in different areas. Studies of sediments and stratigraphy offshore on the continental shelf have increased greatly, but the record of RSL change there remains patchy. Studies onshore have resulted in improvements in the knowledge of rock shorelines, including the processes by which they are formed, but much remains to be understood. Studies of Late Devensian and Holocene RSLs around present coasts have improved knowledge of both the extent and age range of the evidence. The record of RSL change on the W and NW coasts has disclosed a much longer dated RSL record than was available before 1993, possibly with evidence of Meltwater Pulse 1A, while studies in estuaries on the E and SW coasts have disclosed widespread and consistent fluctuations in Holocene RSLs. Evidence for the meltwater pulse associated with the Early Holocene discharge of Lakes Agassiz–Ojibway in N America has been found on both E and W coasts. The effects of the impact of storminess, in particular in cliff-top storm deposits, have been widely identified. Further information on the Holocene Storegga Slide tsunami has enabled a better understanding of the event, but evidence for other tsunami events on Scottish coasts remains uncertain. Methodological developments have led to new reconstructions of RSL change for the last 2000 years, utilising state-of-the-art GIA models and alongside coastal biostratigraphy to determine trends to compare with modern tide gauge and documentary evidence. Developments in GIA modelling have provided valuable information on patterns of land uplift during and following deglaciation. The studies undertaken raise a number of research questions which will require addressing in future work.
The discipline of electroacoustic music is most commonly associated with acousmatic musical forms such as tape-music and musique concrète, and the electroacoustic historical canon primarily centres around the mid-twentieth-century works of Pierre Schaeffer, Karlheinz Stockhausen, John Cage and related artists. As the march of technology progressed in the latter half of the twentieth century, alternative technologies opened up new areas within the electroacoustic discipline such as computer music, hyper-instrument performance and live electronic performance. In addition, the areas of electromagnetic actuation and musical robotics also allowed electroacoustic artists to actualise their works with real-world acoustic sound-objects instead of or along side loudspeakers. While these works owe much to the oft-cited pioneers mentioned above, there exists another equally significant alternative history of artists who utilised electric, electronic, pneumatic, hydraulic and other sources of power to create what is essentially electroacoustic music without loudspeakers. This article uncovers this ‘missing history’ and traces it to its earliest roots over a thousand years ago to shed light on often-neglected technological and artistic developments that have shaped and continue to shape electronic music today.
We report a longitudinal comprehension study of (long) passive constructions in two native-Spanish child groups differing by age of initial exposure to L2 English (young group: 3;0–4;0; older group: 6;0–7;0), where amount of input, L2 exposure environment, and socioeconomic status are controlled. Data from a forced-choice task show that both groups comprehend active sentences, not passives, initially (after 3·6 years of exposure). One year later, both groups improve, but only the older group reaches ceiling on both actives and passives. Two years from initial testing, the younger group catches up. Input alone cannot explain why the younger group takes five years to accomplish what the older group does in four. We claim that some properties take longer to acquire at certain ages because language development is partially constrained by general cognitive and linguistic development (e.g. de Villiers, 2007; Long & Rothman, 2014; Paradis, 2008, 2010, 2011; Tsimpli, 2014).
Staphylococcus aureus is routinely recovered from air and surface samples taken aboard the International Space Station (ISS) and poses a health threat to crew. As bacteria respond to the low shear forces engendered by continuous rotation conditions in a Rotating Wall Vessel (RWV) and the reduced gravitational field of near-Earth flight by altering gene expression, we examined the effect of low-shear RWV growth on protein secretion and gene expression by three S. aureus isolates. When cultured under 1 g, the total amount of protein secreted by these strains varied up to fourfold; under continuous rotation conditions, protein secretion by all three strains was significantly reduced. Concentrations of individual proteins were differentially reduced and no evidence was found for increased lysis. These data suggest that growth under continuous rotation conditions reduces synthesis or secretion of proteins. A limited number of changes in gene expression under continuous rotation conditions were noted: in all isolates vraX, a gene encoding a polypeptide associated with cell wall stress, was down-regulated. A vraX deletion mutant of S. aureus SH1000 was constructed: no differences were found between SH1000 and ΔvraX with respect to colony phenotype, viability, protein export, antibiotic susceptibility, vancomycin kill kinetics, susceptibility to cold or heat and gene modulation. An ab initio protein–ligand docking simulation suggests a major binding site for β-lactam drugs such as imipenem. If such changes to the bacterial phenotype occur during spaceflight, they will compromise the capacity of staphylococci to cause systemic infection and to circumvent antibacterial chemotherapy.
In this article I provide a micro-level analysis of primary schooling in Victorian England. Using a new dataset of school-age males linked between the 1851 and 1881 population censuses, I examine the determinants of childhood school attendance and the impact of attendance on adult labor market outcomes. I find that schooling had a positive effect on adult occupational class and that the associated wage gains were likely to have outweighed the cost of schooling. However, this effect was small relative to father's class, and the effect of education on earnings appears to have been small relative to modern results.
This article analyzes rural-urban migration in Great Britain in the latter half of the nineteenth century. Using a new dataset of 28,000 individuals matched between the 1851 and 1881 population censuses, I examine the selection process and treatment effect of migration, controlling for the endogeneity of the migration decision. I find that urban migrants were positively selected—the best of the rural labor pool—and that the economic benefits of migration were substantial. Migrants responded to market signals, and labor markets were largely efficient; however, not all gains from migration were exploited, potentially indicating some degree of inefficiency.
Solvothermal/hydrothermal reactions of 4, 4′-biphenyldicarboxylic acid (H2bpdc) and cobalt (II) salt with pyridine derivative ligands such as 3-methylpyridine (3-pic), 4-methylpyridine (4-pic), as well as a longer terminal ligand 4-benzylpyridine (4-bzpy) generated four new extended structures: 1D zigzag polymer chain 1 crystallized in C2/c with a formula [Co(bpdc)(3-pic)2]·(3-pic); 1D helical chain compound 2 crystallized in P41 with a formula [Co(bpdc)(4-pic)2], 2D non-interpenetrating network 3 crystallized in P2221 with a formula [Co(bpdc)(4-pic)2]·(4-pic)0.5·H2O, and 2D non-interpenetrating network 4 crystallized in P2/c, formulated as [Co(bpdc)(bzpy)2]. Our studies show that terminal ligands play an important role in affecting the dimensionality and topology of the structures formed. Magnetic susceptibility and isothermal magnetization results revealed an antiferromagnetic ground state for 3 with a transition temperature T = 4.7 K, and paramagnetic behavior at high temperature range for 1 and 2.
We have recently developed a device to measure resistivity and Seebeck values of a material as a function of temperature over a range of 80K < T < 700K. These measurements overlap in temperature with our existing apparatus (4K < T < 320K). These measurements are necessary for the investigation of potential thermoelectric materials at elevated temperatures, where power generation applications are important. The probe design allows for various types of samples to be evaluated from needle like samples ( L ≈ 2mm, D ≈ 50μm ) to larger pressed pellet samples ( ≈ 2mm × 2mm × 10mm). Separate high temperature cartridge heaters are used to stabilize both the absolute temperature, T, as well as the temperature difference, ΔT. Thermocouples measuring T+ΔT/2 and T-ΔT/2 are also employed to measure sample voltages for resistance and thermoelectric power. Design details and measurement specifics will be discussed. Data taken on standards a well as some research samples will be presented.
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