214 research outputs found
Effects of quadriceps strength asymmetry, ageing and external loading on stair negotiation
Ageing is associated with reduced stability and increased risk of falls. One risk factor for falls is sarcopenia: age-related muscle loss. Exaggeration of age-related muscle loss in one limb over the other results in strength asymmetry. This asymmetry typically increases with age and previous research has identified negative impact on gait and stability. This thesis develops to, firstly, identify a reliable method to assess strength asymmetry levels (chapter 5), then investigate the effects of quadriceps strength asymmetry on the biomechanics of stair negotiation in a young population (chapter 6) and âsymmetricalâ and âasymmetricalâ older adults (chapter 7), before, finally, studying the effects of external loading (chapter 8).
In the first study, within- and between-day testing of isometric maximal voluntary contractions of the quadriceps identified this method as a reliable method to assess strength levels in both legs, and the percentage asymmetry between legs. Consequent studies used this method to analyse the effect of age (young adults versus older adults), asymmetry (15%) and load carriage (unloaded versus 5% body weight bilaterally versus 10% body weight unilaterally) on a range of kinetic and kinematics variables during stair ascent and descent. The young healthy population (8.8±8.5% asymmetry) demonstrated only two significant differences in biomechanical variables between the stronger and weaker leg out of 60 variables measured. This was possibly as a result of type I error as absolute differences in mean values were negligible. Older adults (16.6±14.2% asymmetry) demonstrated detrimental effects of ageing regardless of asymmetry level, suggesting the overall loss of quadriceps strength due to age seems to play a key role. Results demonstrated greater effects on centre of mass and centre of pressure inclination angles and knees angles, rather than contact time and ground reaction force, suggesting the loss of strength can be controlled for to a greater extent in contact time and force. Under additional demands of external loading, effects of group (i.e., age and asymmetry) were typically not found and significant effects were instead a result of loading, primarily during unilateral load carriage. Greater ground reaction force and lateral inclination towards the load was demonstrated when stepping on the leg ipsilateral to the load. Overall, while the impact of strength asymmetry was minimal, this thesis highlights the important impact of age-related loss of muscle strength on stability during stair negotiation. Furthermore, the findings suggest splitting loads bilaterally when under the additional demands of loading.N/
Typologies of postnatal support and breastfeeding at two months in the UK.
There is extensive evidence to suggest that social support improves breastfeeding outcomes. Building on this evidence-base, public health services and interventions aiming to improve breastfeeding rates have primarily targeted informational and emotional support to mothers, reflecting an individual behaviour-change approach. However, mothers exist within a wider social network, and the characteristics of their broader support networks may be an important predictor of breastfeeding outcomes. Here we explore the typologies of postnatal support for mothers in the UK; a population with one of the lowest breastfeeding rates in Europe. Using retrospective data from an online survey (data collection period December 2017 - February 2018), we carry out a latent class regression (n = 432) to identify "clusters" of postnatal support in our data. Mothers in our sample were most likely to report receiving practical and emotional support from partners and maternal grandmothers, and breastfeeding information from health professionals. We identify three distinct typologies of postnatal support: 1) Extensive support, where mothers received support from a wide range of supporters including partners, maternal grandmothers, friends and health professionals, but mothers were the only ones to feed the infant; 2) Family support, where mothers received support from partners and maternal grandmothers, including with infant feeding, but less likely to receive support from health professionals; and 3) Low support, where mothers primarily received support from partners. 94% of women with extensive support were predicted to be breastfeeding at two months, followed by 48% of mothers in the low support group, and 13% in the family support group. Our findings highlight the complexities of family support and its potential impact on breastfeeding, as well as the significance of professional support. Overall, our results hint at the potential value for health professionals to engage with wider family in order to achieve extensive support for mothers
In the Right Ballpark? Assessing the Accuracy of Net Price Calculators
Large differences often exist between a collegeâs sticker price and net price after accounting for financial aid. Net price calculators (NPCs) were designed to help students more accurately estimate their actual costs to attend a given college. This study assesses the accuracy of information provided by net price calculators. Specifically, we compare NPC estimates of financial aid to actual aid packages for a sample of low-income, first-time college students at seven postsecondary institutions which all utilize the federal template NPC. We find that NPC estimates of grant aid correlate highly with actual grant aid on average, but variation in individual financial aid packages among socioeconomically similar students can be substantial. We offer four recommendations. First, NPC aid estimates should include information on variability, and potentially, on sources of that variability. Second, a basic metric of academic merit such as SAT/ACT scores and GPA should be an optional addition to the federal template NPC. Third, institutions should update the data underlying their NPCs annually. Finally, we recommend that institutions use the âExplanations and Caveatsâ options on the federal NPC template to include additional information that may be helpful for students and families in anticipating their likely college aid and expenses. Our findings have implications for federal policy related to NPCs
Examples of adapted ethnographic approaches for participatory design
Citation: Kingery-Page, K., Glastetter, A., DeOrsey, D., and J.Falcone (2016)."Examples of adapted ethnographic approaches for participatory design. Landscape Research Record, 5.In landscape architecture practice, participatory design approaches emphasize community workshops and charrettes. But marginalized voices are often suppressed during group meetings, if those at the margins are invited at all. To expand inclusion in the design process, we propose adapting classic ethnographic methods such as one-on-one interviews and direct observation. The benefit of adapted ethnography is that it gives us first-person accounts of a place and of peopleâs needs. Adapted ethnographic methods allow designers to observe how people really use and feel about places, and are well-suited to one-on-one interactions with stakeholders. Although ethnographic methods can be usefully adapted to landscape architecture processes, this adaptation differs from true ethnography. Developing an ethnographic narrative is a deep and long term endeavor, often occupying the majority of an ethnographerâs career. To adapt ethnographic methods for use during a relatively short period of time, a spatial designer must limit the inquiry to a specific âlensâ or particular question related to the community design at hand. Recently, we used an adapted ethnographic approach in the design process for a temporary park and associated streetscape in a Midwestern city with slightly less than a half million residents. We sought to understand downtown residentâs lived experiences downtown, their perceptions of downtown place identity, and what they most valued in a temporary park
Atropisomeric diaryl ethers and other non-biaryl atropisomers
Atropisomerism is a property exhibited by molecules where rotation about one or more bonds is restricted. Along with biaryls, which are widely utilised in asymmetric catalysis, several other classes of compounds display atropisomerism. These molecules have applications in enantioselective synthesis, asymmetric catalysis and have been used to relay stereochemical information. There are, however, a number of challenges associated with their asymmetric synthesis (Chapter 1). This thesis describes research carried out on the synthesis and asymmetric synthesis of atropisomeric diaryl ethers. Chapter 2.1 explains how these ethers are synthesised in multi-gram quantities and to allow the incorporation of large ortho substituents. Having a number of diaryl ethers with suitable substitution patterns to achieve atropisomerism, Chapter 2.2 goes on to report two novel and complimentary biocatalytic approaches to the enantioselective synthesis of diaryl ethers by desymmetrisation. This chapter also describes a possible route towards the synthesis of a diaryl ether based ligand. Chapter 2.3 reports the lateral lithiation of meso diaryl ethers to yield diastereomeric atropisomers stereoselectively. Our attempts to use (-)-sparteine in lateral lithiations to desymmetrise a diaryl ether enantioselectively is also described. We go on to determine the configurational integrity of our organolithiums and the reaction pathway that exists in lithium substitution. Finally, the diastereoselective synthesis of both a diaryl ether (via a stereoselective reduction of a pro-chiral ketone) and a diaryl sulfide (via an addition reaction) is described in chapter 2.4. This chapter also reports the conformational behaviour of a diaryl amide in solution.EThOS - Electronic Theses Online ServiceEPSRCGSK Case AwardGBUnited Kingdo
Atropisomeric diaryl ethers and other non-biaryl atropisomers
Atropisomerism is a property exhibited by molecules where rotation about one or more bonds is restricted. Along with biaryls, which are widely utilised in asymmetric catalysis, several other classes of compounds display atropisomerism. These molecules have applications in enantioselective synthesis, asymmetric catalysis and have been used to relay stereochemical information. There are, however, a number of challenges associated with their asymmetric synthesis (Chapter 1). This thesis describes research carried out on the synthesis and asymmetric synthesis of atropisomeric diaryl ethers. Chapter 2.1 explains how these ethers are synthesised in multi-gram quantities and to allow the incorporation of large ortho substituents. Having a number of diaryl ethers with suitable substitution patterns to achieve atropisomerism, Chapter 2.2 goes on to report two novel and complimentary biocatalytic approaches to the enantioselective synthesis of diaryl ethers by desymmetrisation. This chapter also describes a possible route towards the synthesis of a diaryl ether based ligand. Chapter 2.3 reports the lateral lithiation of meso diaryl ethers to yield diastereomeric atropisomers stereoselectively. Our attempts to use (-)-sparteine in lateral lithiations to desymmetrise a diaryl ether enantioselectively is also described. We go on to determine the configurational integrity of our organolithiums and the reaction pathway that exists in lithium substitution. Finally, the diastereoselective synthesis of both a diaryl ether (via a stereoselective reduction of a pro-chiral ketone) and a diaryl sulfide (via an addition reaction) is described in chapter 2.4. This chapter also reports the conformational behaviour of a diaryl amide in solution.EThOS - Electronic Theses Online ServiceEPSRCGSK Case AwardGBUnited Kingdo
Subjective environmental experiences and womenâs breastfeeding journeys: a survival analysis using an online survey of UK mothers
Local physical and social environmental factors are important drivers of human health and behaviour. Environmental perception has been linked with both reproduction and parenting, but links between subjective environmental experiences and breastfeeding remain unclear. Using retrospective data from an online survey of UK mothers of children aged 0â24 months, Cox-Aalen survival models test whether negative subjective environmental experiences negatively correlated with any and exclusive breastfeeding (max n = 473). Matching predictions, hazards of stopping any breastfeeding were increased, albeit non-significantly, across the five environmental measures (HR: 1.05â1.26) Hazards for stopping exclusive breastfeeding were however (non-significantly) reduced (HR: 0.65â0.87). Score processes found no significant time-varying effects. However, estimated cumulative coefficient graphs showed that the first few weeks postpartum were most susceptible to environmental influences and that contrary to our predictions, mothers with worse subjective environmental experiences were less likely to stop breastfeeding at this time. In addition, the hazard of stopping exclusive breastfeeding declined over time for mothers who thought that littering was a problem. The predicted increased hazards of stopping breastfeeding were only evident in the later stages of any breastfeeding and only for mothers who reported littering as a problem or that people tended not to know each other. Perceived harsher physical and social environmental conditions are assumed to deter women from breastfeeding, but this may not always be the case. Womenâs hazards of stopping breastfeeding change over time and there may be particular timepoints in their breastfeeding journeys where subjective environmental experiences play a rol
Relatedness within and between Agta residential groups
Theoretical models relating to the evolution of human behaviour usually make assumptions about the kinship structure of social groups. Since humans were hunterâgatherers for most of our evolutionary history, data on the composition of contemporary hunterâgatherer groups has long been used to inform these models. Although several papers have taken a broad view of hunterâgatherer social organisation, it is also useful to explore data from single populations in more depth. Here, we describe patterns of relatedness among the Palanan Agta, hunterâgatherers from the northern Philippines. Across 271 adults, mean relatedness to adults across the population is r = 0.01 and to adult campmates is r = 0.074, estimates that are similar to those seen in other hunterâgatherers. We also report the distribution of kin across camps, relatedness and age differences between spouses, and the degree of shared reproductive interest between camp mates, a measure that incorporates affinal kinship. For both this this measure (s) and standard relatedness (r), we see no major age or sex differences in the relatedness of adults to their campmates, conditions that may reduce the potential for conflicts of interest within social groups
Sedentarization and maternal childcare networks: role of risk, gender and demography
Women cooperate over multiple domains and while research from western contexts portrays women's networks as limited in size and breadth, women receive help, particularly with childcare, from a diverse range of individuals (allomothers). Nonetheless, little exploration has occurred into why we see such diversity. Wide maternal childcare networks may be a consequence of a lack of resource accumulation in mobile hunterâgatherersâwhere instead households rely on risk-pooling in informal insurance networks. By contrast, when households settle and accumulate resources, they are able toretain riskby absorbing losses. Thus, the size and composition of mothers' childcare networks may depend on risk-buffering, as captured by mobile and settled households in the Agta, a Philippine foraging population with diverse lifestyles. Across 78 children, we find that childcare from grandmothers and sisters was higher in settled camps, while childcare from male kin was lower, offering little support for risk-buffering. Nonetheless, girlsâ workloads were increased in settled camps while grandmothers had fewer dependent children, increasing their availability. These results point to gender-specific changes associated with shifting demographics as camps become larger and more settled. Evidently, women's social networks, rather than being constrained by biology, are responsive to the changing socioecological context.This article is part of the theme issue âCooperation among women: evolutionary and cross-cultural perspectivesâ
Wealth, health and inequality in Agta foragers
Background and objectivesThere is significant evidence from large-scale, industrial and post-industrial societies that greater income and wealth inequality is negatively associated with both population health and increasing health inequalities. However, whether such relationships are inevitable and should be expected to impact the health of small-scale societies as they become more market-integrated is less clear.MethodologyHere, using mixed-effect models, we explore the relationship between health, wealth, wealth inequality and health inequalities in a small-scale foraging population from the Philippines, the Agta.ResultsAcross 11 camps, we find small to moderate degrees of wealth inequality (maximal Gini Coefficient 0.44) which is highest in the most permanent camps, where individuals engage more heavily in the formal market. However, in both adults (n = 161) and children (n = 215), we find little evidence that either wealth or wealth inequality associates with ill health, except for one measure of nutritional conditionâred blood cell count.Conclusions and implicationsWe interpret these results in the light of high levels of cooperation among the Agta which may buffer against the detrimental effects of wealth inequality documented in industrial and post-industrial societies. We observe little intergenerational wealth transmission, highlighting the fluid nature of wealth, and thus wealth inequality, particularly in mobile communities. The deterioration of nutritional status, as indicated by red blood cell counts, requires further investigation before concluding the Agtaâs extensive cooperation networks may be beginning to breakdown in the face of increasing inequality
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