Geomorphological Investigations in the Torngat Mountains of Northeastern Labrador-Ungava

... The central area of study lay athwart the Labrador-Quebec boundary on the watershed between Nakvak Brook, which drains into Saglek Fiord, and the Koroksoak (Korok) River, which flows westwards into Ungava Bay. ... Attention was concentrated on an extensive system of lateral moraines and kame terraces which slope eastwards from the watershed towards the head of Saglek Fiord. Similar systems were examined in the through-troughs to the south. The whole complex represents the late-Pleistocene limits of trunk glaciers flowing through the mountains towards the east and supplied by an ice cap of continental proportions west of the height of land. At this stage the higher summits stood as nunataks well above the level of the ice, and an extensive series of ice-dammed lakes was held against the western slopes of the highland finding outlets over ice-free cols into the Atlantic. Detailed studies in the watershed area provide a chronology of the final emergence of the area from the last ice sheet, and the draining of the ice-dammed lakes. A final stage was represented by a mass of ice in the lower valley of the Koroksoak which dammed a lake to the level of the col, at 1,050 feet, whence it drained into Nakvak Brook and ultimately into the Atlantic. Glacial erratics, found on summits up to 4,000 feet above sea level, corroborate the conclusions of the previous summer's work suggesting that at some stage the highest summits were inundated by ice flowing from the west. The data compiled from the two summers' work prompt the conclusion that during late-Pleistocene times the Torngat Mountains were influenced by two distinct glaciations, separated by an interglacial period of considerable intensity. The final glaciation, during which large areas remained ice-free, is tentatively correlated with the "classical" Wisconsin of central North America whereas the date of the preceding glacial period is uncertain. It may be the equivalent of the Illinoian Glaciation, or even be of post-Sangamon age, and in this case be comparable with a cold phase tentatively identified in central North America, which is older than the "classical" Wisconsin Glaciation, and is separated from the latter by a warmer period. Reconnaissance from the air during flights along the Labrador coast and some distance inland suggests that these general conclusions might well be applicable to the entire coastal zone of Labrador. ..

Glaciation of the Torngat Mountains, Northern Labrador

Considers role of these mountains in glaciation of Labrador-Ungava, assessing particularly events in late-Wisconsin times with respect to final disappearance of both continental and local ice masses. Conflicting theories are discussed, and evidence presented, based on physiography and findings from summer 1956 field work, including unmistakable erratics on summits at 4,000-5,000 ft. The highest summits were completely submerged by eastward moving continental ice during the Wisconsin glaciation; local glaciers never reached significant dimensions; rapid melting in situ of thick masses of ice occurred during the final Wisconsin stages. Two or three separate glacial periods are recognized from the morphology of the area. Instantaneous glaciation of a large area of the Labrador-Ungava Plateau probably initiated a continental ice sheet in northeastern North America at the onset of each glacial period. Also pub. in International Union of Geodesy and Geophysics, Association of Scientific Hydrology, 11th assembly report of proceedings 1958, v. 4, p. 372-86

Perceptions of trekking tourism and social and environmental change in Nepal's Himalayas

The Himalayas are among the world’s youngest mountain ranges. In addition to the geologic processes of mountain building and erosion, they are also highly vulnerable to human influenced change, occurring at local, national, regional, and international scales. A photo-elicitation methodology is employed to show how residents perceive those changes from historical perspectives, as well as their current conditions and impacts on their daily lives. Nepal’s Khumbu region has undergone major social and environmental transformations since the 1960s when international trekking first began to influence the area's economy. The current perceptions of Khumbu residents of these changes is assessed through photo-elicitation interviews. Their responses are placed in the historical context of: (i) institutional and political changes, much of which have been driven by national government policies; (ii) social and economic changes, for which the tourism economy has been central; and (iii) environmental changes, reflecting the impacts of resource management and climate change. The mostly positive perceptions of Khumbu residents toward how their region has changed reflects general improvements in the physical and cultural landscapes of the Khumbu over time, as well as its continuing geographic isolation, which has helped to slow the rate of globalization, while also keeping the region a dynamic and popular tourist destination

Prediction of disability-free survival in healthy older people

Prolonging survival in good health is a fundamental societal goal. However, the leading determinants of disability-free survival in healthy older people have not been well established. Data from ASPREE, a bi-national placebo-controlled trial of aspirin with 4.7 years median follow-up, was analysed. At enrolment, participants were healthy and without prior cardiovascular events, dementia or persistent physical disability. Disability-free survival outcome was defined as absence of dementia, persistent disability or death. Selection of potential predictors from amongst 25 biomedical, psychosocial and lifestyle variables including recognized geriatric risk factors, utilizing a machine-learning approach. Separate models were developed for men and women. The selected predictors were evaluated in a multivariable Cox proportional hazards model and validated internally by bootstrapping. We included 19,114 Australian and US participants aged ≥65 years (median 74 years, IQR 71.6–77.7). Common predictors of a worse prognosis in both sexes included higher age, lower Modified Mini-Mental State Examination score, lower gait speed, lower grip strength and abnormal (low or elevated) body mass index. Additional risk factors for men included current smoking, and abnormal eGFR. In women, diabetes and depression were additional predictors. The biased-corrected areas under the receiver operating characteristic curves for the final prognostic models at 5 years were 0.72 for men and 0.75 for women. Final models showed good calibration between the observed and predicted risks. We developed a prediction model in which age, cognitive function and gait speed were the strongest predictors of disability-free survival in healthy older people. Trial registration Clinicaltrials.gov (NCT01038583)

Scintillator ageing of the T2K near detectors from 2010 to 2021

The T2K experiment widely uses plastic scintillator as a target for neutrino interactions and an active medium for the measurement of charged particles produced in neutrino interactions at its near detector complex. Over 10 years of operation the measured light yield recorded by the scintillator based subsystems has been observed to degrade by 0.9–2.2% per year. Extrapolation of the degradation rate through to 2040 indicates the recorded light yield should remain above the lower threshold used by the current reconstruction algorithms for all subsystems. This will allow the near detectors to continue contributing to important physics measurements during the T2K-II and Hyper-Kamiokande eras. Additionally, work to disentangle the degradation of the plastic scintillator and wavelength shifting fibres shows that the reduction in light yield can be attributed to the ageing of the plastic scintillator. The long component of the attenuation length of the wavelength shifting fibres was observed to degrade by 1.3–5.4% per year, while the short component of the attenuation length did not show any conclusive degradation