Structural Influences on Participation Rates: A Canada-U.S. Comparison

In contrast to the decline in labour force participation in Canada in the 1990s, the aggregate participation rate in the United States actually rose slightly (up 0.5 percentage points between 1989 and 1997). This US experience provides a useful benchmark for the analysis of the Canadian developments. In the second article of the symposium, Irene Ip, Sheryl King and Geneviève Verdier, while recognizing that cyclical influences have contributed significantly to the decline in labour force participation in the 1990s in Canada relative to the United States, focus on supply-side factors at play in the behviour of the participation rate in the two countries. A key structural variable influencing youth labour force participation is enrolment rates. As the participation rate of students is below that of non-students, increased enrolment tends to reduce aggregate participation. Enrolment rates for teenagers increased 7 percentage points in Canada between 1989 and 1997, and 5 points in the United States; rates for youth adults increased 11 points in Canada and 7 points in the United States. As the U.S. economy enjoyed low unemployment in both 1989 and 1997, the rise in enrolment rates was related to structural factors, such as the growing recognition of the importance of education for success on the job market. Structural factors were undoubtedly at play in Canada . However, the authors suggest that the increase in enrolment rates beyond that experienced in the United States (29 per cent of the increase in enrolment rates for teens and 36 per cent for young adults) may be interpreted as a cyclical response to weak employment opportunities in Canada. The authors find composition changes in the age structure of the population account for about one percentage point of the decline in the aggregate participation rate in Canada between 1989 and 1997, as the relative importance of low-participation rate groups has increased. Based on an analysis of the factors affecting labour force participation of the major age-sex groups, the authors forecast a rise in the aggregate participation rate in Canada from 65.1 per cent in 1998 to 66.6 per cent in 2006. For the United States, the Bureau of Labor Statistics is forecasting a smaller increase, but from a higher level, to 67.6 per cent in 2006 from 67.1 per cent in 1998. The authors expect increases in labour force participation for all age-sex groups in Canada. Between 1998 and 2006, the participation rate is forecast to rise 4.6 percentage points for older men (55 and over), 3.8 points for older women, 3.7 points for prime age women, 8.9 points for teenagers, 3.5 points for young adults, and even 1.0 points for prime-aged men. The 1.5 point increase in the aggregate participation rate is much smaller than almost all the increases in the age-sex group specific rates because of the changing age structure, in particular the increasing proportion of the population in older age groups.Canada, United States, Labour Force Participation, Labor Force Participation, Participation Rate, Labour Force Participation Rate, Labor Force Participation Rate, Age Structure, Age, Sex, Gender, Aging, Ageing

Phonon lasing from optical frequency comb illumination of a trapped ion

An atomic transition can be addressed by a single tooth of an optical frequency comb if the excited state lifetime ($\tau$) is significantly longer than the pulse repetition period ($T_\mathrm{r}$). In the crossover regime between fully-resolved and unresolved comb teeth ($\tau \lessapprox T_\mathrm{r}$), we observe Doppler cooling of a pre-cooled trapped atomic ion by a single tooth of a frequency-doubled optical frequency comb. We find that for initially hot ions, a multi-tooth effect gives rise to lasing of the ion's harmonic motion in the trap, verified by acoustic injection locking. The gain saturation of this phonon laser action leads to a comb of steady-state oscillation amplitudes, allowing hot ions to be loaded directly into the trap and laser cooled to crystallization despite the presence of hundreds of blue-detuned teeth.Comment: 5 pages, 4 figure

Optimisation problems and resolution methods in satellite scheduling and space-craft operation: a survey

The fast development in the production of small, low-cost satellites is propelling an important increase in satellite mission planning and operations projects. Central to satellite mission planning is the resolution of scheduling problem for an optimised allocation of user requests for efficient communication between operations teams at the ground and spacecraft systems. The aim of this paper is to survey the state of the art in the satellite scheduling problem, analyse its mathematical formulations, examine its multi-objective nature and resolution through meta-heuristics methods. Finally, we consider some optimisation problems arising in spacecraft design, operation and satellite deployment systemsPeer ReviewedPostprint (author's final draft

MinION-in-ARMS: Nanopore Sequencing to Expedite Barcoding of Specimen-Rich Macrofaunal Samples From Autonomous Reef Monitoring Structures

Autonomous Reef Monitoring Structure (ARMS) are standardized devices for sampling biodiversity in complex marine benthic habitats such as coral reefs. When coupled with DNA sequencing, these devices greatly expand our ability to document marine biodiversity. Unfortunately, the existing workflow for processing macrofaunal samples (\u3e2-mm) in the ARMS pipeline—which involves Sanger sequencing—is expensive, laborious, and thus prohibitive for ARMS researchers. Here, we propose a faster, more cost-effective alternative by demonstrating a successful application of the MinION-based barcoding approach on the \u3e2 mm-size fraction of ARMS samples. All data were available within 3.5–4 h, and sequencing costs relatively low at approximately US$3 per MinION barcode. We sequenced the 313-bp fragment of the cytochrome c oxidase subunit I (COI) for 725 samples on both MinION and Illumina platforms, and retrieved 507–584 overlapping barcodes. MinION barcodes were highly accurate (∼99.9%) when compared with Illumina reference barcodes. Molecular operational taxonomic units inferred between MinION and Illumina barcodes were consistently stable, and match ratios demonstrated highly congruent clustering patterns (≥0.96). Our method would make ARMS more accessible to researchers, and greatly expedite the processing of macrofaunal samples; it can also be easily applied to other small-to-moderate DNA barcoding projects (\u3c10,000 specimens) for rapid species identification and discovery

The State of the Art of Information Integration in Space Applications

This paper aims to present a comprehensive survey on information integration (II) in space informatics. With an ever-increasing scale and dynamics of complex space systems, II has become essential in dealing with the complexity, changes, dynamics, and uncertainties of space systems. The applications of space II (SII) require addressing some distinctive functional requirements (FRs) of heterogeneity, networking, communication, security, latency, and resilience; while limited works are available to examine recent advances of SII thoroughly. This survey helps to gain the understanding of the state of the art of SII in sense that (1) technical drivers for SII are discussed and classified; (2) existing works in space system development are analyzed in terms of their contributions to space economy, divisions, activities, and missions; (3) enabling space information technologies are explored at aspects of sensing, communication, networking, data analysis, and system integration; (4) the importance of first-time right (FTR) for implementation of a space system is emphasized, the limitations of digital twin (DT-I) as technological enablers are discussed, and a concept digital-triad (DT-II) is introduced as an information platform to overcome these limitations with a list of fundamental design principles; (5) the research challenges and opportunities are discussed to promote SII and advance space informatics in future

Edible crabs “Go West”: migrations and incubation cycle of Cancer pagurus revealed by electronic tags

Crustaceans are key components of marine ecosystems which, like other exploited marine taxa, show seasonable patterns of distribution and activity, with consequences for their availability to capture by targeted fisheries. Despite concerns over the sustainability of crab fisheries worldwide, difficulties in observing crabs’ behaviour over their annual cycles, and the timings and durations of reproduction, remain poorly understood. From the release of 128 mature female edible crabs tagged with electronic data storage tags (DSTs), we demonstrate predominantly westward migration in the English Channel. Eastern Channel crabs migrated further than western Channel crabs, while crabs released outside the Channel showed little or no migration. Individual migrations were punctuated by a 7-month hiatus, when crabs remained stationary, coincident with the main period of crab spawning and egg incubation. Incubation commenced earlier in the west, from late October onwards, and brooding locations, determined using tidal geolocation, occurred throughout the species range. With an overall return rate of 34%, our results demonstrate that previous reluctance to tag crabs with relatively high-cost DSTs for fear of loss following moulting is unfounded, and that DSTs can generate precise information with regards life-history metrics that would be unachievable using other conventional means

Compensation of intra-channel nonlinear fibre impairments using simplified digital back-propagation algorithm

We investigate a digital back-propagation simplification method to enable computationally-efficient digital nonlinearity compensation for a coherently-detected 112 Gb/s polarization multiplexed quadrature phase shifted keying transmission over a 1,600 km link (20x80km) with no inline compensation. Through numerical simulation, we report up to 80% reduction in required back-propagation steps to perform nonlinear compensation, in comparison to the standard back-propagation algorithm. This method takes into account the correlation between adjacent symbols at a given instant using a weighted-average approach, and optimization of the position of nonlinear compensator stage to enable practical digital back-propagation