379 research outputs found

    Relating in situ hydraulic conductivity, particle size and relative density of superficial deposits in a heterogeneous catchment

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    Estimating the permeability of superficial deposits is fundamental to many aspects of catchment science, but can be problematic where insufficient in situ measurements are available from pumping tests in piezometers. Consequently, common practice is to estimate permeability from the material description or, where available, particlesize distribution using a formula such as Hazen. In this study, we examine the relationships between particlesize, relativedensity and hydraulicconductivity in superficial deposits in Morayshire, Northern Scotland: a heterogeneous environment typical of many catchments subject to previous glaciations. The superficial deposits comprise glaciofluvial sands and gravels, glacial tills and moraines, raised marine sediments, and blown sands. Thirty-eight sites were investigated: hydraulicconductivity measurements were made using repeated Guelph permeameter measurements, cone resistance was measured in situ with a Panda dynamic cone penetrometer; material descriptions were made in accordance with BS5930:1999; and disturbed samples were taken for particlesize analysis. Overall hydraulicconductivity (K) varied from 0.001 m/d to >40 m/d; glacial till had the lowest K (median 0.027 m/d) and glacial moraine the highest K (median 30 m/d). However, within each geological unit there was great variability in measured hydraulicconductivity values. Multiple linear regression of the data indicated that log d10 and relativedensity (indicated by cone resistance or BS5930:1999 soil state description) were independent predictors of log K and together gave a relationship with an R2 of 0.80. Material description using the largest fraction (e.g. sand or gravel) had little predictive power. Therefore, in heterogeneous catchments, the permeability of superficial deposits is most strongly related to the finest fraction (d10) and relativedensity of the material. In situ Guelph permeameter measurements at outcrops with good geological characterisation provide an easy and reliable method of determining the permeability of particular units of superficial deposits

    Savings behavior and financial problems among college students: the role of financial literacy in Malaysia

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    This study analyzes the relationship of savings behavior and financial problems to financial literacy among college students in Malaysia. Controlling for correlates of financial literacy, multivariate analysis of a sample obtained at 11 colleges and universities demonstrated that students who had higher financial knowledge test scores were more likely to report savings behavior and also reported fewer financial problems. The influence of childhood consumer experience and financial socialization agents on savings and financial problems was more mixed, indicating that financial experience before college may create bad habits or poor attitudes toward financial management that could be mitigated through financial education during college. Implications of these findings for targeting financial education on particular kinds of students are discussed

    Resilience and longevity: expert survivorship of centenarians

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    Centenarians are survivors, and many among them exemplify sustained competence into very old age. This paper highlights three important resilience domains among centenarians: personal resilience (e.g., personality), cognitive resilience (e.g., intellectual functioning), and social and economic resilience (e.g., social support and economic resources)

    Groundwater, flooding and hydrological functioning in the Findhorn floodplain, Scotland

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    A large floodplain of the River Findhorn, northeast Scotland, was investigated using hydrogeological and hydrochemical methods (including residence time indicators) to characterise groundwater/surface-water coupling and groundwater flooding. The study demonstrated widespread stratification within the floodplain: shallow (30 mm). Persistent groundwater flooding occurs within topographical lows and also in the discharge zone where it is largely managed with a series of drains constructed in the 19th century. The significant and complex role of groundwater in floodplains, demonstrated by this study, highlights the importance of fully considering groundwater in flood management schemes

    The Relationship between Physical Health and Psychological Well-Being among Oldest-Old Adults

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    The purpose of this study was to evaluate the relationship between physical health and psychological well-being among oldest-old adults. Structural equation modeling was performed to examine health influences on psychological well-being among 306 octogenarians and centenarians from the Georgia Centenarian Study. Latent variables were created to reflect subjective health, as measured by self-ratings of health and objective health, as measured by physical health impairment (i.e., health problems, past and present diseases, hospitalization) and biomarkers (i.e., hemoglobin and albumin). Psychological well-being was measured by positive and negative affect. There were significant direct effects of subjective health on affect and significant indirect effects of objective health through subjective health on positive affect and negative affect. Subjective health took the role of a mediator between objective health and psychological well-being. These results highlight the status and perceptions of health as a critical indicator for well-being in extreme old age

    Correlates of Functional Capacity Among Centenarians

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    This study investigated correlates of functional capacity among participants of the Georgia Centenarian Study. Six domains (demographics and health, positive and negative affect, personality, social and economic support, life events and coping, distal influences) were related to functional capacity for 234 centenarians and near centenarians (i.e., 98 years and older). Data were provided by proxy informants. Domain-specific multiple regression analyses suggested that younger centenarians, those living in the community and rated to be in better health were more likely to have higher functional capacity scores. Higher scores in positive affect, conscientiousness, social provisions, religious coping, and engaged lifestyle were also associated with higher levels of functional capacity. The results suggest that functional capacity levels continue to be associated with age after 100 years of life and that positive affect levels and past lifestyle activities as reported by proxies are salient factors of adaptation in very late life

    Group Structure and Behaviour of Babirusa (Babyrousa babyrussa) in Northern Sulawesi

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    Studies were carried out at two ‘salt-licks’ in lowland tropical forest on North Sulawesi, Indonesia. During 60 days of observation 586 sightings of babirusa were made comprising 161 of adult males, 155 of adult females, 11 adults of unknown sex, 78 of subadult males, 53 of subadult females and 34 subadults of indeterminate sex; juveniles were observed 94 times, 19 males, 12 females and 63 of unknown sex. We saw 226 groups ranging in size from one to eight animals (median = 2). Almost half the sightings were of solitary animals, usually adult males. Bachelor groups of four or more babirusa were never seen. Adult females were rarely seen without company, often both juveniles and subadults being sighted together with them. There were never more than three adult females in a group. There were about twice as many family groups without adult males as there were with males. Agonistic behaviour between males was confined to ‘threat at a distance’, ‘nose in the air’, ‘head under jaw submission’ and ‘front half supported’ behaviours. There were fewer incidents of female-female agonistic behaviour, but in two, the dominant female chased her inferior off the ‘salt-lick’

    Comparing the Support-Efficacy Model among Centenarians Living in Private Homes, Assisted Living Facilities, and Nursing Homes

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    We investigated the influence of social relations on health outcomes in very late life by examining the support-efficacy convoy model among older adults who resided in three different residential environments (centenarians in private homes, n = 126; centenarians in assisted living facilities, n = 55; centenarians in nursing homes, n = 105). For each group, path analytic models were employed to test our hypotheses; analyses controlled for sex, mental status, education, perceived economic sufficiency, and activities of daily living. The hypothesized relationships among the models' variables were unique to each of the three groups; three different models fit the data depending upon residential environment. The direct and indirect effects of social relations assessments were positive for the mental and physical health of very old adults, suggesting that participants welcomed the support. However, residential status moderated the associations between the assessments of social relations, self-efficacy, and both outcomes, physical and mental health

    Meltwater flow through a rapidly deglaciating glacier and foreland catchment system: Virkisjökull, SE Iceland

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    Virkisjökull is a rapidly retreating glacier in south-east Iceland. A proglacial lake has formed in the last ten years underlain by buried ice. In this study we estimate water velocities through the glacier, proglacial foreland and proglacial river using tracer tests and continuous meltwater flow measurements. Tracer testing from a glacial moulin to the glacier outlet in September 2013 demonstrated a rapid velocity of 0.58 m s�1. This was comparable to the velocity within the proglacial river, also estimated from tracer testing. A subsequent tracer test from the same glacial moulin under low flow conditions in May 2014 demonstrated a slower velocity of 0.07 m s�1. The glacier outlet river sinks back into the buried ice, and a tracer test from this sink point through the proglacial foreland to the meltwater river beyond the lake indicated a velocity of 0.03 m s�1,suggesting that an ice conduit system within the buried ice is transferring water rapidly beneath the lake. Ground penetrating radar profiles confirm the presence of this buried conduit system. This study provides an example of rapid deglaciation being associated with extensive conduit systems that enable rapid meltwater transfer from glaciers through the proglacial area to meltwater rivers

    Large-scale survey of seasonal drinking water quality in Malawi using in situ tryptophan-like fluorescence and conventional water quality indicators

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    Faecally-contaminated drinking water is a risk to human health, with the greatest risks to those living in developing countries. UN Sustainable Development Goal 6 aims to address this issue. Tryptophan-like fluorescence (TLF) shows potential as a rapid method for detecting microbial contamination in drinking water, which could reduce the spread of waterborne diseases. This study is the first to investigate the effectiveness of TLF for a large-scale survey using a randomised, spot-sampling approach. The large-scale survey took place in Malawi, sub-Saharan Africa, in the dry season (n = 183). A subset of sources were revisited at the end of the following wet season (n = 41). The effectiveness of TLF was assessed by comparing TLF results to thermotolerant coliforms (TTC), humic-like fluorescence (HLF), inorganic hydrochemical data and sanitary risk scores. The most prominent differences in microbial water quality were observed between source types, with little variation between districts and seasons. TLF, TTCs, turbidity and sanitary risk scores were all elevated at alternative sources (shallow wells and tap stands) compared to hand-pumped boreholes. In the dry season, 18% of hand-pumped boreholes showed TTC contamination, which increase to 21% in the wet season. Groundwater recharge processes are likely responsible for seasonal variability of inorganic hydrochemistry at hand-pumped boreholes. TLF was able to distinguish no and low WHO risk classes (TTC 0–9 cfu/100 mL) from medium, high and very high risk classes (TTC 10 – >1000 cfu/100 mL). TLF failed to distinguish between no and low risk classes, which limits the use of TLF for assessing water quality to drinking water standards. This dataset indicates that HLF may raise baseline TLF for samples with low TLF values, increasing false positives. Therefore, TLF is better suited as a rapid high-level water quality screening tool to assess moderate and high levels of faecal contamination
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