Attitudes of Nunavut Inuit toward Killer Whales (Orcinus orca)

Killer whale (Orcinus orca) sightings are increasing throughout the eastern Canadian Arctic, and residents of Nunavut are concerned about the possible impact of killer whale predation on other marine mammals that are of socio-economic and cultural importance to Inuit. We analyzed the attitudes of Inuit towards killer whales, drawing on 105 semi-directed interviews conducted in 11 eastern Nunavut communities (Kivalliq and Qikiqtaaluk regions) between 2007 and 2010. Information gathered included interviewees’ firsthand knowledge, as well as knowledge they had gained through oral history. Interviews provided data on interactions between Inuit and killer whales, physical descriptions and nature of killer whales in this region, overall opinion of interviewees with respect to killer whales, historical use of the animal, opinions regarding research on killer whales and effects of killer whales on other species, particularly the whales and seals harvested for Inuit subsistence. Interviewees described killer whales as their helpers more often than as their competitors, but also as feared and dangerous. Overall, negative opinions were more common than positive opinions, and some interviewees also had a conflicted attitude towards killer whales. More participants viewed killer whales as smart and fast than as beautiful and playful. Inuit attitudes toward killer whales did not vary significantly with sex, age, hunter status, or experience with killer whales, but did vary somewhat across regions. Inuit knowledge and perspectives play a critical role in wildlife management, especially in a changing Arctic. Conservation and management of species that are important to the Inuit subsistence harvest in Nunavut must take into consideration killer whale predation, Inuit knowledge, and Inuit views and attitudes towards killer whales.Les observations d’épaulards (Orcinus orca) augmentent dans l’est de l’Arctique canadien, et les habitants du Nunavut s’inquiètent des effets possibles de la prédation des épaulards à l’égard d’autres mammifères marins qui revêtent une importance socioéconomique et culturelle pour les Inuits. Nous avons analysé les attitudes des Inuits vis-à-vis des épaulards, nous appuyant ainsi sur 105 entrevues semi-dirigées réalisées dans 11 collectivités de l’est du Nunavut (les régions de Kivalliq et de Qikiqtaaluk) entre 2007 et 2010. Les connaissances directes des personnes interviewées font partie des renseignements qui ont été recueillis, de même que les connaissances obtenues par le biais de l’histoire orale. Les entrevues ont ainsi permis d’obtenir des données sur les interactions entre les Inuits et les épaulards, sur les descriptions physiques et sur la nature des épaulards de cette région, en plus de recueillir l’opinion générale des personnes interviewées au sujet des épaulards, l’utilisation historique de cet animal, les opinions en matière de recherche sur les épaulards et les effets des épaulards sur d’autres espèces, plus particulièrement les baleines et les phoques capturés pour la subsistance des Inuits. Selon les personnes interviewées, les épaulards leur viennent davantage en aide au lieu d’entrer en concurrence avec elles, mais cela dit, elles les craignent et les trouvent dangereux. Dans l’ensemble, il y avait plus d’opinions négatives que d’opinions positives, et certaines personnes interviewées avaient même une attitude conflictuelle à l’égard des épaulards. Plus nombreux étaient les participants qui considéraient les épaulards comme intelligents et rapides que comme beaux et enjoués. Les attitudes des Inuits envers les épaulards ne variaient pas beaucoup en fonction du sexe, de l’âge, du type de chasseur ou de l’expérience qu’ils possédaient avec les épaulards, mais ils variaient quelque peu d’une région à l’autre. Les connaissances et les perspectives des Inuits jouent un rôle critique dans la gestion de la faune, surtout dans l’Arctique en pleine évolution. La conservation et la gestion des espèces qui revêtent de l’importance dans les récoltes de subsistance des Inuits au Nunavut doivent tenir compte de la prédation par les épaulards, des connaissances des Inuits de même que des points de vue et des attitudes des Inuits vis-à-vis des épaulards

First mid-infrared spectrum of a faint high-z galaxy: Observations of CFRS 14.1157 with the Infrared Spectrograph on the Spitzer Space Telescope

The unprecedented sensitivity of the Infrared Spectrograph on the Spitzer Space Telescope allows for the first time the measurement of mid-infrared spectra from 14 to 38 microns of faint high-z galaxies. This unique capability is demonstrated with observations of sources having 16 micron fluxes of 3.6 mJy (CFRS 14.1157) and 0.35 mJy (CFRS 14.9025). A spectral-fitting technique is illustrated which determines the redshift by fitting emission and absorption features characteristic of nearby galaxies to the spectrum of an unknown source. For CFRS 14.1157, the measured redshift is z = 1.00+/-0.20 in agreement with the published result of z = 1.15. The spectrum is dominated by emission from an AGN, similar to the nucleus of NGC 1068, rather than a typical starburst with strong PAH emission like M82. Such spectra will be crucial in characterizing the nature of newly discovered distant galaxies, which are too faint for optical follow-up.Comment: Accepted in ApJ Sup. Spitzer Special Issue, 4 pages, 5 figure

A Spitzer Infrared Spectrograph Survey of Warm Molecular Hydrogen in Ultra-luminous Infrared Galaxies

We have conducted a survey of Ultra-luminous Infrared Galaxies (ULIRGs) with the Infrared Spectrograph on the Spitzer Space Telescope, obtaining spectra from 5.0-38.5um for 77 sources with 0.02<z <0.93. Observations of the pure rotational H2 lines S(3) 9.67um, S(2) 12.28um, and S(1) 17.04um are used to derive the temperature and mass of the warm molecular gas. We detect H2 in 77% of the sample, and all ULIRGs with F(60um)>2Jy. The average warm molecular gas mass is ~2x10^8solar-masses. High extinction, inferred from the 9.7um silicate absorption depth, is not observed along the line of site to the molecular gas. The derived H2 mass does not depend on F(25um)/F(60um), which has been used to infer either starburst or AGN dominance. Similarly, the molecular mass does not scale with the 25 or 60um luminosities. In general, the H2 emission is consistent with an origin in photo-dissociation regions associated with star formation. We detect the S(0) 28.22um emission line in a few ULIRGs. Including this line in the model fits tends to lower the temperature by ~50-100K, resulting in a significant increase in the gas mass. The presence of a cooler component cannot be ruled out in the remainder of our sample, for which we do not detect the S(0) line. The measured S(7) 5.51um line fluxes in six ULIRGs implies ~3x10^6 solar-masses of hot (~1400K) H2. The warm gas mass is typically less than 1% of the cold gas mass derived from CO observations.Comment: Accepted ApJ 01 September 2006, v648n1 issue. 14 pages 12 figures IRAS 06361-6217 the f25/f60 ratio is 0.10 not 1.0

Spectroscopic Redshifts to z > 2 for Optically Obscured Sources Discovered with the Spitzer Space Telescope

We have surveyed a field covering 9.0 degrees^2 within the NOAO Deep Wide-Field Survey region in Bootes with the Multiband Imaging Photometer on the Spitzer Space Telescope (SST) to a limiting 24 um flux density of 0.3 mJy. Thirty one sources from this survey with F(24um) > 0.75 mJy which are optically very faint (R > 24.5 mag) have been observed with the low-resolution modules of the Infrared Spectrograph on SST. Redshifts derived primarily from strong silicate absorption features are reported here for 17 of these sources; 10 of these are optically invisible (R > 26 mag), with no counterpart in B_W, R, or I. The observed redshifts for 16 sources are 1.7 < z < 2.8. These represent a newly discovered population of highly obscured sources at high redshift with extreme infrared to optical ratios. Using IRS spectra of local galaxies as templates, we find that a majority of the sources have mid-infrared spectral shapes most similar to ultraluminous infrared galaxies powered primarily by AGN. Assuming the same templates also apply at longer wavelengths, bolometric luminosities exceed 10^13 L(solar).Comment: Accepted for publication on 7 Feb 2005 in ApJL. 7 pages 2 figure

Spitzer IRS Spectra of Optically Faint Infrared Sources with Weak Spectral Features

Spectra have been obtained with the low-resolution modules of the Infrared Spectrograph (IRS) on the Spitzer Space Telescope (Spitzer) for 58 sources having f$_{\nu}$(24 micron) > 0.75 mJy. Sources were chosen from a survey of 8.2 deg$^{2}$ within the NOAO Deep Wide-Field Survey region in Bootes (NDWFS) using the Multiband Imaging Photometer (MIPS) on the Spitzer Space Telescope. Most sources are optically very faint (I > 24mag). Redshifts have previously been determined for 34 sources, based primarily on the presence of a deep 9.7 micron silicate absorption feature, with a median z of 2.2. Spectra are presented for the remaining 24 sources for which we were previously unable to determine a confident redshift because the IRS spectra show no strong features. Optical photometry from the NDWFS and infrared photometry with MIPS and the Infrared Array Camera on the Spitzer Space Telescope (IRAC) are given, with K photometry from the Keck I telescope for some objects. The sources without strong spectral features have overall spectral energy distributions (SEDs) and distributions among optical and infrared fluxes which are similar to those for the sources with strong absorption features. Nine of the 24 sources are found to have feasible redshift determinations based on fits of a weak silicate absorption feature. Results confirm that the "1 mJy" population of 24 micron Spitzer sources which are optically faint is dominated by dusty sources with spectroscopic indicators of an obscured AGN rather than a starburst. There remain 14 of the 58 sources observed in Bootes for which no redshift could be estimated, and 5 of these sources are invisible at all optical wavelengths.Comment: Accepted by Ap

Estimating the Economic Value of Narwhal and Beluga Hunts in Hudson Bay, Nunavut

Hunting of narwhal (Monodon monoceros) and beluga (Delphinapterus leucas) in Hudson Bay is an important activity, providing food and income in northern communities, yet few studies detail the economic aspects of these hunts. We outline the uses of narwhal and beluga and estimate the revenues, costs, and economic use value associated with the hunt on the basis of the harvests in 2007. We also explore the effects of cost sharing and inclusion of opportunity cost of labour on model outputs. For the communities participating in each hunt, the average economic use value was negative (-$9399) for beluga and positive ($133 278) for narwhal. The corresponding per capita value estimates were -$1 for beluga and$44 for narwhal. Including the effects of costEvaluation of a Technique to Trap Lemmings Under the Snow sharing with one other hunting activity in the model increased the economic use values to $266 504 for beluga and$321 500 for narwhal. Narwhals provide a higher value per whale, in addition to a higher per capita total economic value to the community, compared to belugas because resources are shared among fewer communities. However, the beluga hunt overall provides greater revenue because more belugas are harvested. In keeping with literature on other hunting activities in the Arctic, our results indicate that the value of whales to communities is largely due to their food value. Dans la baie d’Hudson, la chasse au narval (Monodon monoceros) et au béluga (Delphinapterus leucas) représente une activité importante en ce sens qu’elle est à la fois une source de nourriture et de revenu pour les collectivités du Nord. Pourtant, peu d’études se penchent sur les aspects économiques de cette activité. Nous faisons mention des utilités du narval et du béluga, puis nous estimons les revenus, les coûts et la valeur utilitaire économique liée à ces activités de chasse en fonction des récoltes de 2007. De plus, nous explorons les effets du partage des coûts et de l’inclusion du coût de substi­tution de la main-d’oeuvre à l’égard des sorties de modèles. Pour les collectivités qui participent à chaque chasse, la valeur utilitaire économique moyenne était négative (‑9 399 $) dans le cas du béluga et positive (133 278$) dans le cas du narval. Les estimations correspondantes des valeurs par habitant étaient de - 1 $pour le béluga et de 44$ pour le narval. L’inclusion des effets du partage des coûts avec une autre activité de chasse au modèle a pour effet d’accroître la valeur utilitaire économique à 266 504 $pour le béluga, et à 321 500$ pour le narval. Les narvals donnent une plus grande valeur par baleine, ainsi qu’une valeur économique totale plus élevée par habitant pour la collectivité, comparativement aux bélugas car les ressources sont partagées entre un moins grand nombre de collectivités. Cependant, dans son ensemble, la chasse au béluga procure un revenu plus élevé parce qu’un plus grand nombre de bélugas est récolté. Conformément à la documentation publiée sur d’autres activités de chasse dans l’Arctique, nos résultats indiquent que pour les collectivités, la valeur des baleines réside princi­palement dans leur valeur alimentaire

The role of body rotation in bacterial flagellar bundling

In bacterial chemotaxis, E. coli cells drift up chemical gradients by a series of runs and tumbles. Runs are periods of directed swimming, and tumbles are abrupt changes in swimming direction. Near the beginning of each run, the rotating helical flagellar filaments which propel the cell form a bundle. Using resistive-force theory, we show that the counter-rotation of the cell body necessary for torque balance is sufficient to wrap the filaments into a bundle, even in the absence of the swirling flows produced by each individual filament