The Sinking of the M.S. Explorer: Implications for Cruise Tourism in Arctic Canada

BUILT IN 1969, AND AFFECTIONATELY KNOWN as “thelittle red ship, ” the MS Explorer was the first vesselspecifically designed for transport of passengers in the polar regions (Fig. 1). Under the name Lindblad Ex-plorer, she took passengers to Antarctica in the 1969–70 austral summer (Splettstoesser, 2000), and in 1984 sh

A Review of Tourism Research in the Polar Regions

Polar travel has grown dramatically in the last two decades and in recent years has become the focus of academic inquiry. Using a model initially developed for understanding the nature of culture, action, and knowledge in the development of human geography, we explore the nature, scale, and scope of research related to tourism in the Arctic and the Antarctic. We take a comparative approach to highlight the tourism issues that are largely similar in the two polar regions. Polar tourism research appears to cluster around four main areas: tourism patterns, tourism impacts, tourism policy and management, and tourism development. By assessing these emerging research clusters, we identify research gaps and potentially fruitful lines of inquiry.Ces vingt dernières années, les voyages polaires ont beaucoup gagné en popularité, au point où une équipe de chercheurs s’est récemment penchée sur cette forme de tourisme. À l’aide d’un modèle qui servait, à l’origine, à comprendre la nature de la culture, de l’action et des connaissances du développement de la géographie humaine, on a exploré la nature, l’échelle et l’étendue des recherches effectuées en rapport avec le tourisme dans l’Arctique et dans l’Antarctique. Grâce à une démarche comparative, on a mis en évidence les enjeux touristiques qui se ressemblent beaucoup dans les deux régions polaires. La recherche sur le tourisme polaire semble se concentrer sur quatre grands aspects, soit les tendances en matière de tourisme, les incidences du tourisme, les politiques et la gestion du tourisme ainsi que le développement du tourisme. Grâce à l’évaluation de ces aspects de la recherche, on réussit à déterminer les écarts de recherche ainsi que les champs d’enquête qui pourraient éventuellement porter fruits

Duality Invariance of Cosmological Perturbation Spectra

I show that cosmological perturbation spectra produced from quantum fluctuations in massless or self-interacting scalar fields during an inflationary era remain invariant under a two parameter family of transformations of the homogeneous background fields. This relates slow-roll inflation models to solutions which may be far from the usual slow-roll limit. For example, a scale-invariant spectrum of perturbations in a minimally coupled, massless field can be produced by an exponential expansion with $a\propto e^{Ht}$, or by a collapsing universe with $a\propto (-t)^{2/3}$.Comment: 5 pages, Latex with Revtex. Hamiltonian formulation added and discussion expanded. Version to appear in Phys Rev

Genesis of ancestral haplotypes: RNA modifications and reverse transcription–mediated polymorphisms

Understanding the genesis of the block haplotype structure of the genome is a major challenge. With the completion of the sequencing of the Human Genome and the initiation of the HapMap project the concept that the chromosomes of the mammalian genome are a mosaic, or patchwork, of conserved extended block haplotype sequences is now accepted by the mainstream genomics research community. Ancestral Haplotypes (AHs) can be viewed as a recombined string of smaller Polymorphic Frozen Blocks (PFBs). How have such variant extended DNA sequence tracts emerged in evolution? Here the relevant literature on the problem is reviewed from various fields of molecular and cell biology particularly molecular immunology and comparative and functional genomics. Based on our synthesis we then advance a testable molecular and cellular model. A critical part of the analysis concerns the origin of the strand biased mutation signatures in the transcribed regions of the human and higher primate genome, A-to-G versus T-to-C (ratio ~1.5 fold) and C-to-T versus G-to-A (≥1.5 fold). A comparison and evaluation of the current state of the fields of immunoglobulin Somatic Hypermutation (SHM) and Transcription-Coupled DNA Repair focused on how mutations in newly synthesized RNA might be copied back to DNA thus accounting for some of the genome-wide strand biases (e.g., the A-to-G vs T-to-C component of the strand biased spectrum). We hypothesize that the genesis of PFBs and extended AHs occurs during mutagenic episodes in evolution (e.g., retroviral infections) and that many of the critical DNA sequence diversifying events occur first at the RNA level, e.g., recombination between RNA strings resulting in tandem and dispersed RNA duplications (retroduplications), RNA mutations via adenosine-to-inosine pre-mRNA editing events as well as error prone RNA synthesis. These are then copied back into DNA by a cellular reverse transcription process (also likely to be error-prone) that we have called "reverse transcription-mediated long DNA conversion." Finally we suggest that all these activities and others can be envisaged as being brought physically under the umbrella of special sites in the nucleus involved in transcription known as "transcription factories."

Cruise Tourism and Sea Ice in Canada's Hudson Bay Region

Tourism in the Hudson Bay region of central northern Canada generally is associated with non-consumptive forms of nature-based activities (such as polar bear viewing). However, the region has experienced variable growth in the cruise sector in recent years. This paper examines patterns of cruise activity in all subregions of the Hudson Bay region during three cruise seasons (2006, 2008, and 2009) and mainly reveals a pattern of decline. Since the prevalence of sea ice is an important part of visitor experiences of polar cruises, we examine sea ice change and occurrence of icebergs in the Hudson Bay region. Our sea ice analysis suggests that the length of the navigable shipping season is increasing in this region, which may facilitate both earlier and later shipping. But in terms of cruise traffic, we suggest that the demise of ice coverage signals a possible decline in cruise activity in most of the Hudson Bay region because ice-supported wildlife may shift north with the diminishing ice regime. Given the possible environmental and socio-cultural implications of changing cruise activity patterns in the Arctic and the absence of broad-scale monitoring and surveillance of the industry, use of these available data sources is vital to building a clearer picture.De manière générale, le tourisme dans la région de la baie d’Hudson du centre-nord du Canada se rapporte à des activités non consomptibles en plein air (comme l’observation des ours polaires). Toutefois, ces dernières années, le secteur des croisières de cette région a enregistré un taux de croissance variable. La présente communication se penche sur les tendances en matière de croisières dans toutes les sous-régions de la région de la baie d’Hudson au cours de trois saisons de croisière (2006, 2008 et 2009), ce qui laisse principalement entrevoir un déclin à cet égard. Puisque l’existence de glace de mer revêt une grande importance pour les visiteurs des croisières polaires, nous avons examiné les changements en matière de glace de mer et l’occurrence d’icebergs dans la région de la baie d’Hudson. Notre analyse de la glace de mer laisse voir que la longueur de la saison de navigation augmente dans cette région, ce qui peut avoir pour effet de faciliter la navigation en début et en fin de saison. Cela dit, sur le plan de la circulation de croisière, nous donnons à penser que la disparition de la couche de glace laisse entrevoir un déclin possible des activités de croisière dans la plupart de la région de la baie d’Hudson parce que la faune qui évolue sur la glace pourrait s’en aller vers le nord en raison du régime de glaces à la baisse. Compte tenu des incidences environnementales et socioculturelles susceptibles de découler des tendances changeantes relativement aux activités de croisière dans l’Arctique et de l’absence de suivi et de surveillance à grande échelle de l’industrie, il est essentiel de recourir aux sources de données disponibles afin d’obtenir un meilleur aperçu de la situation

Sea Ice in Canada’s Arctic: Implications for Cruise Tourism

Although cruise travel to the Canadian Arctic has grown steadily since 1984, some commentators have suggested that growth in this sector of the tourism industry might accelerate, given the warming effects of climate change that are making formerly remote Canadian Arctic communities more accessible to cruise vessels. Using sea-ice charts from the Canadian Ice Service, we argue that Global Climate Model predictions of an ice-free Arctic as early as 2050–70 may lead to a false sense of optimism regarding the potential exploitation of all Canadian Arctic waters for tourism purposes. This is because climate warming is altering the character and distribution of sea ice, increasing the likelihood of hull-penetrating, high-latitude, multi-year ice that could cause major pitfalls for future navigation in some places in Arctic Canada. These changes may have negative implications for cruise tourism in the Canadian Arctic, and, in particular, for tourist transits through the Northwest Passage and High Arctic regions.Bien que le nombre de voyages de croisières se soit accru régulièrement depuis 1984, certains commentateurs ont laissé entendre que la croissance de ce secteur de l’industrie touristique pourrait s’intensifier en raison des effets de réchauffement du changement climatique qui rendent des lieux de l’Arctique canadien autrefois éloignés plus accessibles aux navires de croisière. En nous appuyant sur les cartes de la fréquence de présence de glace de mer du Service canadien des glaces, nous soutenons que les prédictions du modèle climatique mondial selon lesquelles il n’y aurait plus de glace dans l’Arctique dès les années 2050 à 2070 pourraient engendrer un faux sens d’optimisme en ce qui a trait à l’exploitation éventuelle de toutes les eaux de l’Arctique canadien à des fins touristiques. Cela s’explique par le fait que le réchauffement climatique modifie le caractère et la répartition de la glace de mer, ce qui a pour effet d’augmenter la possibilité de la présence de glace de haute latitude datant de nombreuses années et capable de pénétrer les coques, glace qui pourrait présenter des pièges importants en matière de navigation future dans certains endroits de l’Arctique canadien. Ces changements pourraient avoir des incidences négatives sur le tourisme de croisière dans l’Arctique canadien et, en particulier, sur les transits touristiques dans le passage du Nord-Ouest et les régions de l’Extrême-Arctique

Observational constraints on an inflation model with a running mass

We explore a model of inflation where the inflaton mass-squared is generated at a high scale by gravity-mediated soft supersymmetry breaking, and runs at lower scales to the small value required for slow-roll inflation. The running is supposed to come from the coupling of the inflaton to a non-Abelian gauge field. In contrast with earlier work, we do not constrain the magnitude of the supersymmetry breaking scale, and we find that the model might work even if squark and slepton masses come from gauge-mediated supersymmetry breaking. With the inflaton and gaugino masses in the expected range, and $\alpha = g^2/4\pi$ in the range $10^{-2}$ to $10^{-3}$ (all at the high scale) the model can give the observed cosmic microwave anisotropy, and a spectral index in the observed range. The latter has significant variation with scale, which can confirm or rule out the model in the forseeable future.Comment: Latex, 19 pages, 14 figures, uses epsf.st

Searching for Signatures of Cosmic Superstrings in the CMB

Because cosmic superstrings generically form junctions and gauge theoretic strings typically do not, junctions may provide a signature to distinguish between cosmic superstrings and gauge theoretic cosmic strings. In cosmic microwave background anisotropy maps, cosmic strings lead to distinctive line discontinuities. String junctions lead to junctions in these line discontinuities. In turn, edge detection algorithms such as the Canny algorithm can be used to search for signatures of strings in anisotropy maps. We apply the Canny algorithm to simulated maps which contain the effects of cosmic strings with and without string junctions. The Canny algorithm produces edge maps. To distinguish between edge maps from string simulations with and without junctions, we examine the density distribution of edges and pixels crossed by edges. We find that in string simulations without Gaussian noise (such as produced by the dominant inflationary fluctuations) our analysis of the output data from the Canny algorithm can clearly distinguish between simulations with and without string junctions. In the presence of Gaussian noise at the level expected from the current bounds on the contribution of cosmic strings to the total power spectrum of density fluctuations, the distinction between models with and without junctions is more difficult. However, by carefully analyzing the data the models can still be differentiated.Comment: 15 page

Three-dimensional airway volumes and most constricted areas in children

poster abstractObjective: The objectives of this retrospective study using cone beam computed tomography (CBCT) were to determine if there are differences in the volume of various airway segments and the most constricted area (MCA) of children with different dentoskeletal patterns. Methods: The initial CBCTs of 83 orthodontic patients (30 Angle’s Class I; 26 Class II; and 27 Class III) were collected from a private orthodontic office. Following reliability studies, various parameters of the craniofacial complex, airway volume, and MCA were measured utilizing Dolphin 3D software. Comparisons among the three dental and the skeletal malocclusion classes were performed using one-way ANOVA and Fishers Protected Least Significant. Associations of the airway volumes and the MCA with other parameters were determined using correlation coefficients, accepting p < 0.05 as significant for all tests. Results: Maxillary right sinus volume was the only airway segment showing significant difference among different dental classes. Maxillary sinus volume also correlated moderately with anterior facial height and mandibular length. No significant differences were found between the MCA and different dentoskeletal classifications. Conclusions: The only significant difference in airway parameters among the dentoskeletal classes was that the dental Class II subjects had greater right sinus volume than the other classes. Shorter anterior facial height or mandibular length could be indicators for decreased airway volume in children. Funding: IUSD Graduate Research Committee, IUPUI Three-Dimensional Imaging of the Craniofacial Complex Center, Jarabak Endowed Professorshi