An Analysis of Youth and Adult Ontario Recreational Travel Characteristics: A Pilot Study in the City of Waterloo for the Summer of 1972

This paper examines the travel patterns of youth and adult recreational participants from Waterloo, Ontario. Specifically, the study pertains to the travel done by these participants in Ontario, during the summer of 1972, and as such, contributes to the sparse literature available on the subject. It is discovered, that when youth are disaggregated from the population, one is able to determine the recreation travel differences between both parties, with a high degree of accuracy. The fact that a large percent of youth and adults frequent areas of their particular choice, indicates that there must be recognizable characteristics in both parties which address this type of activity. The travel patterns of all recreationalists are influenced to different degrees by time, locale, participants, period, and economics. The effect of these variables can be determined for the individual groups. By analysis of the characters which govern and regulate the degree of recreation participation, the state of familiarity can be established for the activities undertaken. Those individuals who are interested in learning how youth and adult populations function in the spatial dimension, may well find this paper useful

Embracing the mantra of modellers and synthesizing omics, experiments and models

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/136256/1/emi412491.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/136256/2/emi412491_am.pd

Advancing Geomicrobiology and Microbial Geochemistry

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/106754/1/eost2014EO100008.pd

Photosynthetic Versatility in the Genome of Geitlerinema sp. PCC 9228 (Formerly Oscillatoria limnetica ‘Solar Lake’), a Model Anoxygenic Photosynthetic Cyanobacterium

Anoxygenic cyanobacteria that use sulfide as the electron donor for photosynthesis are a potentially influential but poorly constrained force on Earth’s biogeochemistry. Their versatile metabolism may have boosted primary production and nitrogen cycling in euxinic coastal margins in the Proterozoic. In addition, they represent a biological mechanism for limiting the accumulation of atmospheric oxygen, especially before the Great Oxidation Event and in the low-oxygen conditions of the Proterozoic. In this study, we describe the draft genome sequence of Geitlerinema sp. PCC 9228, formerly Oscillatoria limnetica ‘Solar Lake’, a mat-forming diazotrophic cyanobacterium that can switch between oxygenic photosynthesis and sulfide-based anoxygenic photosynthesis. Geitlerinema possesses three variants of psbA, which encodes protein D1, a core component of the photosystem II reaction center. Phylogenetic analyses indicate that one variant is closely affiliated with cyanobacterial psbA genes that code for a D1 protein used for oxygen-sensitive processes. Another version is phylogenetically similar to cyanobacterial psbA genes that encode D1 proteins used under microaerobic conditions, and the third variant may be cued to high light and/or elevated oxygen concentrations. Geitlerinema has the canonical gene for sulfide quinone reductase (SQR) used in cyanobacterial anoxygenic photosynthesis and a putative transcriptional regulatory gene in the same operon. Another operon with a second, distinct sqr and regulatory gene is present, and is phylogenetically related to sqr genes used for high sulfide concentrations. The genome has a comprehensive nif gene suite for nitrogen fixation, supporting previous observations of nitrogenase activity. Geitlerinema possesses a bidirectional hydrogenase rather than the uptake hydrogenase typically used by cyanobacteria in diazotrophy. Overall, the genome sequence of Geitlerinema sp. PCC 9228 highlights potential cyanobacterial strategies to cope with fluctuating redox gradients and nitrogen availability that occur in benthic mats over a diel cycle. Such dynamic geochemical conditions likely also challenged Proterozoic cyanobacteria, modulating oxygen production. The genetic repertoire that underpins flexible oxygenic/anoxygenic photosynthesis in cyanobacteria provides a foundation to explore the regulation, evolutionary context, and biogeochemical implications of these co-occurring metabolisms in Earth history

Curvature corrections in DGP brane cosmology

We consider a DGP inspired brane scenario where the action on the brane is augmented by a function of the Ricci scalar, ${\cal L}(R)$. The cosmological implications that such a scenario entails are examined for $R^{n}$ and shown to be consistent with a universe expanding with power-law acceleration. It is shown that two classes of solutions exist for the usual FRW metric and small Hubble radii. When the Hubble radius becomes larger, we either have a transition to a fully 5D regime or to a self-inflationary solution which produces a late accelerated expansion such that the radius becomes a function of $n$.Comment: 11 pages, 2 figure

Graviton Mass or Cosmological Constant?

To describe a massive graviton in 4D Minkowski space-time one introduces a quadratic term in the Lagrangian. This term, however, can lead to a readjustment or instability of the background instead of describing a massive graviton on flat space. We show that for all local Lorentz-invariant mass terms Minkowski space is unstable. We start with the Pauli-Fierz (PF) term that is the only local mass term with no ghosts in the linearized approximation. We show that nonlinear completions of the PF Lagrangian give rise to instability of Minkowski space. We continue with the mass terms that are not of a PF type. Although these models are known to have ghosts in the linearized approximations, nonlinear interactions can lead to background change due to which the ghosts are eliminated. In the latter case, however, the graviton perturbations on the new background are not massive. We argue that a consistent theory of a massive graviton on flat space can be formulated in theories with extra dimensions. They require an infinite number of fields or non-local description from a 4D point of view.Comment: 16 pages; references and comments adde

Brans-Dicke DGP Brane Cosmology

We consider a five dimensional DGP-brane scenario endowed with a non-minimally coupled scalar field within the context of Brans-Dicke theory. This theory predicts that the mass appearing in the gravitational potential is modified by the addition of the mass of the effective intrinsic curvature on the brane. We also derive the effective four dimensional field equations on a 3+1 dimensional brane where the fifth dimension is assumed to have an orbifold symmetry. Finally, we discuss the cosmological implications of this setup, predicting an accelerated expanding universe with a value of the Brans-Dicke parameter $\omega$ consistent with values resulting from the solar system observations.Comment: 12 pages, 1 figure, to appear in JCA

International partnerships in developing and deploying health open educational resources

Lack of training opportunities for new and practicing health care professionals constitutes a major barrier to patient care in many developing countries. Open Educational Resources (OER) hold the potential to provide more training materials and alternative learning opportunities for health professionals. OER are teaching and learning materials made freely and openly available for students, faculty, and self learners around the world. OER is not an online distance learning program. The focus of OER is on scaling up teaching and learning capacity in partner institutions by co-creating new learning materials and converting existing materials into OER. The context for which OER content is produced is often different from the contexts in which it is used. Thus, one of the major challenges of OER is to understand how to create a sustainable OER model to ensure that OER production and use fit different learning and teaching environments. The panel will share their perspectives on the following issues: - How are different types of OER created and packaged for delivery and use? - What are the challenges brought about by different contexts of knowledge creation and use? - How do we design new tools and leverage the existing tools (Sakai course management system, Adobe Connect and similar web conferencing systems, OpenCast and lecture capture systems) to facilitate the creation and use of knowledge? - How can we produce sustainable models of OER creation and use?Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/78320/1/1450460148_ftp.pd

Versatile Photophysiology of Compositionally Similar Cyanobacterial Mat Communities Inhabiting Submerged Sinkholes of Lake Huron

Recently discovered submerged sinkholes in Lake Huron are high-sulfur, lowoxygen extreme environments for microbial life. In order to understand the relationship between the physical environment, photophysiology and community composition, we measured the physical conditions, photophysiological indices, and genetic diversity at 3 microbial mat sites bathed in high conductivity groundwater under a natural light gradient during 2012 and 2013. A strong seasonal trend prevailed at all sites, characterized by decreased photosynthetic yield (Fv’/Fm’; 0.25 to 0.40) during the summer (April to August) and increased yield (0.70 to 0.75) during the winter (November to March). Chlorophyll a content varied seasonally in a similar manner to photo - synthetic yield. All sites were dominated by \u3e80% abundance of one cyanobacterial group, most closely related to Phormidium sp. Phycobilins (phycocyanin and phycoerythrin) were consistently higher in concentration than chlorophyll. Photosynthetic yield was statistically indistinguishable between sites, suggesting that these mat communities are able to acclimate across a wide range of photosynthetically active radiation (PAR). Interestingly, these cyanobacteria carried out oxygenic photosynthesis in the presence of in vitro H2S, further suggestive of their versatile photophysiologies under variable redox conditions. Collectively, our study provides insight into the adaptive capabilities of cyanobacteria by revealing how they photophysiologically respond to changes in light climate and redox conditions, and are thereby able to inhabit a wide range of physico-chemical environments. Such versatile physiologies may have enabled their ancestors to thrive across a range of habitats on early Earth