The Problem of Membership in International Organization

Membership problems plague international organizations of all types. All organizations are in some way exclusive, and there is a hierarchy of acceptable joiner-nations with the European nations leading the list. Each organization appears statistically to have a norm of membership toward which its number tends. If it falls short of the norm, it is under compulsion to expand. If it exceeds the norm, expulsions or boycotts are likely to ensue. The ideal condition of an organization, therefore, is normal membership, not necessarily total inclusion of all nations legally admissable. More is to be lost by too large an organization than by one too small. There is a superfluity of discrete national memberships in separate organizations, which necessitates amalgamation of organizations

A Catalogue of Optically Selected Cores

We present a new catalogue of 406 dense cores optically selected by using the STScI Digitized Sky Survey (DSS). In this catalogue 306 cores have neither an Embedded YSO (EYSO) nor a Pre-Main-Sequence (PMS) star, 94 cores have EYSOs (1 core has both an EYSO and a PMS star), and 6 cores have PMS star only. Our sample of dense cores in the catalogue is fairly complete within a category of northern Lynds class 5, 6 clouds, and southern Hartley et al. (1986)'s class A clouds, providing a database useful for the systematic study of dense cores. Most of the cores listed in the catalogue have diameters between $0.05 - 0.36$ pc with a mean of $\sim 0.24$ pc. The sizes ($\sim 0.33$ pc in the mean) of cores with EYSOs are found to be usually larger than the sizes ($\sim 0.22$ pc in the mean) of starless cores. The typical mean gas density of the cores is $\sim7\times 10^3 cm^{-3}$. Most of the cores are more likely elongated than spherical (mean aspect ratio: $\sim 2.4$). The ratio of the number of cores with EYSOs to the number of starless cores for our sample is about 0.3, suggesting that the typical lifetime of starless cores is $0.3-1.6$ Myr, about 3 times longer than the duration of the Class 0 and Class I phases. This lifetime is shorter than expected from models of ambipolar diffusion, by factors of 2-44.Comment: 22 pages, 8 figures, 3 tables, and to appear in ApJS. Harvard-Smithsonian Center for Astrophysic

Habitual levels of higher, but not medium or low, impact physical activity are positively related to lower limb bone strength in older women:findings from a population based study using accelerometers to classify impact magnitude

Summary: This study assessed the effect of accelerometry-measured higher impacts resulting from habitual weight-bearing activity on lower limb bone strength in older women. Despite higher impacts being experienced rarely in this population-based cohort, positive associations were observed between higher vertical impacts and lower limb bone size and strength.  Introduction: We investigated whether the benefit of habitual weight-bearing physical activity (PA) for lower limb bone strength in older women is explained by exposure to higher impacts, as previously suggested by observations in younger individuals.  Methods: Four hundred and eight women from the Cohort for Skeletal Health in Bristol and Avon (COSHIBA), mean 76.8 years, wore tri-axial accelerometers at the waist for a mean of 5.4 days. Y-axis peaks were categorised, using previously identified cutoffs, as low (0.5–1.0 g), medium (1.0–1.5 g), and higher (≥1.5 g) impacts. Mid and distal peripheral quantitative computed tomography scans of the tibia and radius were performed, as were hip and lumbar spine Dual X-ray Absorptiometry (DXA) scans. Regressions between (log transformed) number of low, medium and high impacts, and bone outcomes were adjusted for artefact error grade, age, height, fat and lean mass and impacts in other bands.  Results: Eight thousand eight hundred and nine (4047, 16,882) low impacts were observed during the measurement week, 345 (99, 764) medium impacts and 42 (17, 106) higher impacts (median with 25th and 75th quartiles). Higher vertical impacts were positively associated with lower limb bone strength as reflected by cross-sectional moment of inertia (CSMI) of the tibia [0.042 (0.012, 0.072) p = 0.01] and hip [0.067 (0.001, 0.133) p = 0.045] (beta coefficients show standard deviations change per doubling in impacts, with 95 % confidence interval). Higher impacts were positively associated with tibial periosteal circumference (PC) [0.015 (0.003, 0.027) p = 0.02], but unrelated to hip BMD. Equivalent positive associations were not seen for low or medium impacts. Conclusions: Despite their rarity, habitual levels of higher impacts were positively associated with lower limb bone size and strength, whereas equivalent relationships were not seen for low or medium impacts

Self-Regulation in a Web-Based Course: A Case Study

Little is known about how successful students in Web-based courses self-regulate their learning. This descriptive case study used a social cognitive model of self-regulated learning (SRL) to investigate how six graduate students used and adapted traditional SRL strategies to complete tasks and cope with challenges in a Web-based technology course; it also explored motivational and environmental influences on strategy use. Primary data sources were three transcribed interviews with each of the students over the course of the semester, a transcribed interview with the course instructor, and the students’ reflective journals. Archived course documents, including transcripts of threaded discussions and student Web pages, were secondary data sources. Content analysis of the data indicated that these students used many traditional SRL strategies, but they also adapted planning, organization, environmental structuring, help seeking, monitoring, record keeping, and self-reflection strategies in ways that were unique to the Web-based learning environment. The data also suggested that important motivational influences on SRL strategy use—self-efficacy, goal orientation, interest, and attributions—were shaped largely by student successes in managing the technical and social environment of the course. Important environmental influences on SRL strategy use included instructor support, peer support, and course design. Implications for online course instructors and designers, and suggestions for future research are offered

'The terrible twos': Gaining control in the nursery?

'The terrible twos' are often described as a time of 'gaining control', usually thought of as adults asserting control over children, who learn to control themselves. However, toddlerhood is as much about children learning to take control for themselves. This paper is an attempt to detail something of the social geography in the toddler room of a Scottish nursery, considering both styles of adult control and the ways in which toddlers attempt to appropriate and reconfigure space and time for themselves. That is, the ways in which space and time are negotiated in the course of day-to-day nursery life