Above and below the water: Social/ecological transformation in northwest Newfoundland

Marine fisheries and fishing societies develop around the resources provided by a particular ecosystem. As they exploit these resources, fisheries transform the ecosystem, which pushes fishery and society to adapt in turn. This process is illustrated by fisheries, ecological and social data tracking dramatic changes on Newfoundland\u27s Northern Peninsula and its adjacent marine ecosystem, the northern Gulf of St. Lawrence. There a longstanding fishery for cod and other groundfish collapsed in the 1990s, and was replaced by fisheries targeting invertebrates. The new invertebrate fisheries have different socioeconomic characteristics than the former groundfish fisheries. The shift in target species reflects deep ecological changes that were underway at least a decade before official recognition of the crisis. Our analysis of biological data reveals that the main ecological changes occurred during “the glory years” of the 1980s, when Newfoundland\u27s domestic fisheries were at their peak. Overfishing and interactions with adverse climatic conditions drove the changes. As the ecosystem transformed, human population declined due to outmigration, and social indicators show signs of distress. Accounts by outport residents paint a generational picture of social change

Ethnic identity and aspirations among rural Alaska youth

The villages of rural Alaska comprise one of the most exceptional, yet least visible, sociocultural environments in the United States They are geographically remote, and set off from the mainstream also by their unique Eskimo, Indian or Aleut cultures. At the same time many economic, legal and cultural connections pull these villages toward the dominant U.S. society, impelling continual and rapid social change. Our research focuses on adolescents growing up in this culturally complex and changing environment. We employ survey data from adolescents in 19 rural schools to explore relationships between ethnic identity and students\u27 expectations about moving away or attending college. Many students describe their ethnic identity as mixed, both Native and non-Native. On some key variables, the responses of mixed-identity students fall between those of Natives and non-Natives, supporting a theoretical conception of ethnicity as a matter of degree rather than category. Migration and college expectations vary with ethnic identity, but the college expectations/identity relationship fades when we adjust for other variables. Ethnicity affects expectations for the most part indirectly, through “cultural tool kit” variables including family role models and support. Gender differences in expectations, on the other hand, remain substantial even after adjusting for other variables

Ridge Formation and De-Spinning of Iapetus via an Impact-Generated Satellite

We present a scenario for building the equatorial ridge and de-spinning Iapetus through an impact-generated disk and satellite. This impact puts debris into orbit, forming a ring inside the Roche limit and a satellite outside. This satellite rapidly pushes the ring material down to the surface of Iapetus, and then itself tidally evolves outward, thereby helping to de-spin Iapetus. This scenario can de-spin Iapetus an order of magnitude faster than when tides due to Saturn act alone, almost independently of its interior geophysical evolution. Eventually, the satellite is stripped from its orbit by Saturn. The range of satellite and impactor masses required is compatible with the estimated impact history of Iapetus.Comment: 19 pages, 3 figures; Icarus, in pres

Acute Modifications of Circulating Volume and Respiratory Maneuvers in the Cardiovascular Assessment of Long-Duration Crewmembers

This U.S. - Russian project is aimed at improved assessment of cardiac and vascular parameters associated with circulating volume and its distribution in long-duration space flight. Objective responses to modified Valsalva and Mueller maneuvers were measured by cardiac and vascular ultrasound before, during, and after temporary volume redistribution by means of Braslet-M thigh occlusion cuffs (Russia). Braslet-M cuffs are custom fitted to each crewmember prior to launch on the Soyuz as a Russian countermeasure for space adaptation fluid shift

Temporomandibular joint anatomy: Ultrasonographic appearances and sexual dimorphism

Abstract: Introduction: Temporomandibular joint (TMJ) dysfunction is common, with a greater prevalence in females. While magnetic resonance imaging (MRI) is commonly used for clinical investigation, ultrasonography represents a potential alternative in some clinical scenarios. We designed a protocol for ultrasonographic evaluation of the TMJ and assessed its reliability. Presentation was compared between the sexes to establish whether an anatomical dichotomy underlies the female preponderance of TMJ dysfunction. Materials and methods: Ultrasound imaging of the TMJ was carried out in the longitudinal and oblique planes. Standard images were produced using model skulls and healthy volunteers. Measurements were made between the temporal bone, mandibular condyle, joint capsule and overlying skin, as well as of condylar translation during mouth opening. Both joints were scanned in 50 healthy volunteers. Measurements were repeated to evaluate reliability. A novel classification system was used to assess lateral condylar morphology. Results: The protocol facilitated reliable visualization of key anatomical features of the TMJ (average intraclass correlation coefficient = 0.75, p ¯ = 5.4E‐03). Distribution of condylar morphology differed between the sexes. The capsular‐cutaneous distance (‘joint depth’) and condylar‐temporal bone distance (‘interarticular distance’) were significantly greater in males than in females. Conclusions: Ultrasonography provides reliable views of the TMJ in two planes: longitudinal and oblique. Observed sexual dimorphism in TMJ anatomy might be associated with the female preponderance of dysfunction. With a standardized scanning protocol, ultrasound could provide a rapid, cost‐effective alternative to MRI as a point‐of‐care imaging tool in TMJ clinics

Geographically touring the eastern bloc: British geography, travel cultures and the Cold War

This paper considers the role of travel in the generation of geographical knowledge of the eastern bloc by British geographers. Based on oral history and surveys of published work, the paper examines the roles of three kinds of travel experience: individual private travels, tours via state tourist agencies, and tours by academic delegations. Examples are drawn from across the eastern bloc, including the USSR, Poland, Romania, East Germany and Albania. The relationship between travel and publication is addressed, notably within textbooks, and in the Geographical Magazine. The study argues for the extension of accounts of cultures of geographical travel, and seeks to supplement the existing historiography of Cold War geography

The influence of specimen size on measurement of thermal or irradiation creep in pressurized tubes

This report discusses thin-walled pressurized tubes which have been developed for measurement of thermal creep and irradiation creep. Miniaturization of these tubes allows more tests to be conducted in the limited reactor space available and decreases the impact of displacement rate gradients and temperature gradients. Studies conducted on a variety of tube sizes show that, when specimen fabrication history and irradiation conditions are properly accounted for, miniaturization can be successfully achieved without producing invalid data

Pulsar rotation measures and the large-scale structure of Galactic magnetic field

The large-scale magnetic field of our Galaxy can be probed in three dimensions using Faraday rotation of pulsar signals. We report on the determination of 223 rotation measures from polarization observations of relatively distant southern pulsars made using the Parkes radio telescope. Combined with previously published observations these data give clear evidence for large-scale counterclockwise fields (viewed from the north Galactic pole) in the spiral arms interior to the Sun and weaker evidence for a counterclockwise field in the Perseus arm. However, in interarm regions, including the Solar neighbourhood, we present evidence that suggests that large-scale fields are clockwise. We propose that the large-scale Galactic magnetic field has a bisymmetric structure with reversals on the boundaries of the spiral arms. Streaming motions associated with spiral density waves can directly generate such a structure from an initial inwardly directed radial field. Large-scale fields increase toward the Galactic Center, with a mean value of about 2~$\mu$G in the Solar neighbourhood and 4~$\mu$G at a Galactocentric radius of 3 kpc.Comment: ApJ accepted. 16 pages, 14 figures, 2 tables, 223 pulsar RM

Cooperation and Contagion in Web-Based, Networked Public Goods Experiments

A longstanding idea in the literature on human cooperation is that cooperation should be reinforced when conditional cooperators are more likely to interact. In the context of social networks, this idea implies that cooperation should fare better in highly clustered networks such as cliques than in networks with low clustering such as random networks. To test this hypothesis, we conducted a series of web-based experiments, in which 24 individuals played a local public goods game arranged on one of five network topologies that varied between disconnected cliques and a random regular graph. In contrast with previous theoretical work, we found that network topology had no significant effect on average contributions. This result implies either that individuals are not conditional cooperators, or else that cooperation does not benefit from positive reinforcement between connected neighbors. We then tested both of these possibilities in two subsequent series of experiments in which artificial seed players were introduced, making either full or zero contributions. First, we found that although players did generally behave like conditional cooperators, they were as likely to decrease their contributions in response to low contributing neighbors as they were to increase their contributions in response to high contributing neighbors. Second, we found that positive effects of cooperation were contagious only to direct neighbors in the network. In total we report on 113 human subjects experiments, highlighting the speed, flexibility, and cost-effectiveness of web-based experiments over those conducted in physical labs

Right Ventricular Tissue Doppler Assessment in Space During Circulating Volume Modification using the Braslet-M Device

This joint U.S. - Russian work aims to establish a methodology for assessing cardiac function in microgravity in association with manipulation of central circulating volume. Russian Braslet-M occlusion cuffs were used to temporarily increase the volume of blood in the lower extremities, which effectively reduces the volume returning to the heart in the central circulation. A novel methodology was tested on the International Space Station (ISS) to assess the volume status of crewmembers by evaluating the responses to application and release of the Braslet-on-occlusion cuffs, as well as to modified Valsalva and Mueller maneuvers. Baseline echocardiographic tissue Doppler imaging (TDI) of the right ventricular free wall with no Braslet applied shows early diastolic E' (16 cm/sec), late diastolic A' (14 cm/sec), and systolic (12 cm/sec) velocities compatible with normal subjects on Earth. TDI of the RV free wall with Braslet applied shows that early diastolic E' decreased by 50% (8 cm/sec), late diastolic A' increased by 45%, and systolic S' remains unchanged. TDI of the RV free wall approximately 8 beats after the Braslet was released shows early diastolic E' (8 cm/sec), late diastolic A' (12 cm/sec), and systolic S' (13 cm/sec) velocities. During this portion of the release, early diastolic E' did not recover to baseline values but late diastolic A' and systolic S' recovered to pre-Braslet values. The pre-systolic cross-sectional area of the internal jugular vein with Braslet off was 1.07 cm(sup 2) and 1.13 cm(sup 2) 10 min after the Braslet was applied. The presystolic cross-sectional area of the common femoral vein with Braslet off was 0.50 cm(sup 2), and was 0.54 cm(sup 2) 10 min after the Braslet was applied. The right ventricular myocardial performance Tei index also was calculated for comparison with typical values found in healthy subjects on Earth. Baseline and Braslet-on values for Tei index were 0.25 and 0.22 respectively. Braslet Tei indices are within normal ranges found in healthy subjects and temporarily become greater than 0.4 during the dynamic Braslet release portion of this study. Tissue Doppler imaging of the right ventricle revealed that the Braslet influenced cardiac preload and that fluid was sequestered in the lower-extremity interstitial and vascular space after only 10 minutes of application. This report demonstrates that Braslet application affects right ventricular physiology in long-duration space flight based on TDI and that this effect is in part due to venous hemodynamics