Nature, Prescribed: Evaluating Social Outdoor Activity as a Solution to Loneliness

There is a rich array of studies and scientific reviews documenting the psychological wellbeing derived from contact with nature and outdoor activity. The primary avenue in the literature connecting nature to improved mental and physical health is through nature&rsquo;s restorative and stress-reducing qualities, its capacity to focus our attention, and our biological tendency to prefer natural settings. However, less is known about the effects of social connection in the outdoors as another possible mechanism underlying the positive relationship between wellness and nature. Social connectedness experienced while spending time outdoors with others is being reviewed as an avenue to reduce stress and improve mood and overall wellbeing. In this dissertation, I examine the potential for nature-based social activities to serve as an antidote to loneliness via three studies of individuals learning and socializing in the natural world. I explore the impact of socially organized nature-based activities including community gardening, nature walks, nature photography, nature-based mindfulness activities, and nature-based educational and arts activities on study participants&rsquo; socioemotional wellbeing. I take a multidisciplinary, community-based approach to identify ideal features of nature-based social interventions, using qualitative interviewing, participant observation, cross-sectional and pre-post survey, group based photo elicitation, and reflective journal analysis. Situated in the global loneliness epidemic, this dissertation builds on the evidence of how nature-based interventions impact population health by evaluating the inputs that could be applied to a broader non-medical prescribing modality for addressing loneliness.&nbsp;</p

Searching for Scandinavians in pre-Viking Scotland : Molecular fingerprinting of Early Medieval combs

The character and chronology of Norse colonisation in Early Medieval northern Scotland (8th–10th centuries AD) is hotly debated. The presence of reindeer antler raw material in ‘native’ or ‘Pictish’ type combs from the Orkney Isles, northern Scotland has been put forward as evidence for a long and largely peaceful initial period of cultural contact, as opposed to a shorter, more polarised period probably in the late ninth century. Here this hypothesis is tested using a minimally-destructive collagen peptide mass fingerprinting method (ZooMS) to speciate the raw material of 20 combs. Eleven were identified as red deer, four as reindeer and one as whale. The accuracy and gentleness of this method was tested by the subsequent application of ancient DNA (aDNA) methods to fourteen of the same samples: in ten, amplification was successful and all supported the preliminary ZooMS identification. All ‘native’-type combs in the sample are identified as red deer, and all Norse types as reindeer. These results challenge previous species identifications for these combs' raw materials. The balance of evidence no longer supports the existence of a long period of cultural contact between Atlantic Scotland and Scandinavian settlers before the late 9th century. ZooMS is shown to have considerable potential for identification of worked bone and antler artefacts, with applications in archaeology and wildlife/art-history forensics

Upward spirals of positive emotion and coping: Replication, extension, and initial exploration of neurochemical substrates

The broaden-and-build theory (Fredrickson, 1998, 2001) predicts that positive emotions broaden the scopes of attention and cognition, thereby facilitating the building of personal resources and initiating upward spirals toward increasing emotional well-being. This study attempts to replicate and extend previous empirical support for this model. Using a sample of 185 undergraduates, we assessed whether positive affect and broad-minded coping, interpersonal trust, and social support reciprocally and prospectively predict one another over a two-month period, and whether this upward spiral might be partially based in changes in dopaminergic functioning. As hypothesized, PA and positive coping did mutually build on one another, as did PA and interpersonal trust. Contrary to expectation, PA did not demonstrate an upward spiral relation with social support. Results suggest further study of the relationship between PA and changes in dopamine metabolite levels over time is warranted

A measurement of the tau mass and the first CPT test with tau leptons

We measure the mass of the tau lepton to be 1775.1+-1.6(stat)+-1.0(syst.) MeV using tau pairs from Z0 decays. To test CPT invariance we compare the masses of the positively and negatively charged tau leptons. The relative mass difference is found to be smaller than 3.0 10^-3 at the 90% confidence level.Comment: 10 pages, 4 figures, Submitted to Phys. Letts.

A Measurement of Rb using a Double Tagging Method

The fraction of Z to bbbar events in hadronic Z decays has been measured by the OPAL experiment using the data collected at LEP between 1992 and 1995. The Z to bbbar decays were tagged using displaced secondary vertices, and high momentum electrons and muons. Systematic uncertainties were reduced by measuring the b-tagging efficiency using a double tagging technique. Efficiency correlations between opposite hemispheres of an event are small, and are well understood through comparisons between real and simulated data samples. A value of Rb = 0.2178 +- 0.0011 +- 0.0013 was obtained, where the first error is statistical and the second systematic. The uncertainty on Rc, the fraction of Z to ccbar events in hadronic Z decays, is not included in the errors. The dependence on Rc is Delta(Rb)/Rb = -0.056*Delta(Rc)/Rc where Delta(Rc) is the deviation of Rc from the value 0.172 predicted by the Standard Model. The result for Rb agrees with the value of 0.2155 +- 0.0003 predicted by the Standard Model.Comment: 42 pages, LaTeX, 14 eps figures included, submitted to European Physical Journal

First Measurement of Z/gamma* Production in Compton Scattering of Quasi-real Photons

We report the first observation of Z/gamma* production in Compton scattering of quasi-real photons. This is a subprocess of the reaction e+e- to e+e-Z/gamma*, where one of the final state electrons is undetected. Approximately 55 pb-1 of data collected in the year 1997 at an e+e- centre-of-mass energy of 183 GeV with the OPAL detector at LEP have been analysed. The Z/gamma* from Compton scattering has been detected in the hadronic decay channel. Within well defined kinematic bounds, we measure the product of cross-section and Z/gamma* branching ratio to hadrons to be (0.9+-0.3+-0.1) pb for events with a hadronic mass larger than 60 GeV, dominated by (e)eZ production. In the hadronic mass region between 5 GeV and 60 GeV, dominated by (e)egamma* production, this product is found to be (4.1+-1.6+-0.6) pb. Our results agree with the predictions of two Monte Carlo event generators, grc4f and PYTHIA.Comment: 18 pages, LaTeX, 5 eps figures included, submitted to Physics Letters

Measurement of the B0 Lifetime and Oscillation Frequency using B0->D*+l-v decays

The lifetime and oscillation frequency of the B0 meson has been measured using B0->D*+l-v decays recorded on the Z0 peak with the OPAL detector at LEP. The D*+ -> D0pi+ decays were reconstructed using an inclusive technique and the production flavour of the B0 mesons was determined using a combination of tags from the rest of the event. The results t_B0 = 1.541 +- 0.028 +- 0.023 ps, Dm_d = 0.497 +- 0.024 +- 0.025 ps-1 were obtained, where in each case the first error is statistical and the second systematic.Comment: 17 pages, 4 figures, submitted to Phys. Lett.

Measurement of the B+ and B-0 lifetimes and search for CP(T) violation using reconstructed secondary vertices

The lifetimes of the B+ and B-0 mesons, and their ratio, have been measured in the OPAL experiment using 2.4 million hadronic Z(0) decays recorded at LEP. Z(0) --> b (b) over bar decays were tagged using displaced secondary vertices and high momentum electrons and muons. The lifetimes were then measured using well-reconstructed charged and neutral secondary vertices selected in this tagged data sample. The results aretau(B+) = 1.643 +/- 0.037 +/- 0.025 pstau(Bo) = 1.523 +/- 0.057 +/- 0.053 pstau(B+)/tau(Bo) = 1.079 +/- 0.064 +/- 0.041,where in each case the first error is statistical and the second systematic.A larger data sample of 3.1 million hadronic Z(o) decays has been used to search for CP and CPT violating effects by comparison of inclusive b and (b) over bar hadron decays, No evidence fur such effects is seen. The CP violation parameter Re(epsilon(B)) is measured to be Re(epsilon(B)) = 0.001 +/- 0.014 +/- 0.003and the fractional difference between b and (b) over bar hadron lifetimes is measured to(Delta tau/tau)(b) = tau(b hadron) - tau((b) over bar hadron)/tau(average) = -0.001 +/- 0.012 +/- 0.008

Search for Higgs Bosons in e+e- Collisions at 183 GeV

The data collected by the OPAL experiment at sqrts=183 GeV were used to search for Higgs bosons which are predicted by the Standard Model and various extensions, such as general models with two Higgs field doublets and the Minimal Supersymmetric Standard Model (MSSM). The data correspond to an integrated luminosity of approximately 54pb-1. None of the searches for neutral and charged Higgs bosons have revealed an excess of events beyond the expected background. This negative outcome, in combination with similar results from searches at lower energies, leads to new limits for the Higgs boson masses and other model parameters. In particular, the 95% confidence level lower limit for the mass of the Standard Model Higgs boson is 88.3 GeV. Charged Higgs bosons can be excluded for masses up to 59.5 GeV. In the MSSM, mh > 70.5 GeV and mA > 72.0 GeV are obtained for tan{beta}>1, no and maximal scalar top mixing and soft SUSY-breaking masses of 1 TeV. The range 0.8 < tanb < 1.9 is excluded for minimal scalar top mixing and m{top} < 175 GeV. More general scans of the MSSM parameter space are also considered.Comment: 49 pages. LaTeX, including 33 eps figures, submitted to European Physical Journal

Measurement of triple gauge boson couplings from WW production at LEP energies up to 189 GeV

A measurement of triple gauge boson couplings is presented, based on W-pair data recorded by the OPAL detector at LEP during 1998 at a centre-of-mass energy of 189 GeV with an integrated luminosity of 183 pb^-1. After combining with our previous measurements at centre-of-mass energies of 161-183 GeV we obtain k_g=0.97 +0.20 -0.16, g_1^z=0.991 +0.060 -0.057 and lambda_g=-0.110 +0.058 -0.055, where the errors include both statistical and systematic uncertainties and each coupling is determined by setting the other two couplings to their SM values. These results are consistent with the Standard Model expectations.Comment: 28 pages, 8 figures, submitted to Eur. Phys. J.