Nitrogen Isotopes in Deep Sea Corals; A Potential Tracer of Paleoceanographic Conditions

Abstract In the face of anthropogenic climate change, increasing pressure is being mounted on contextualizing current climate altercations compared to those of the past. One key tracer of climate variation is the isotopic ratio of 15N compared to 14N, which tracks biological and chemical reactions throughout the N cycle. However, it is difficult to find accurate palaeoceanographic records of N isotope fractionation, as most sedimentary and organic samples are subject to extensive diagenesis, degradation, and erosive processes. Scleractinian corals present a potential solution to this lack of accurate data. Multiple studies indicate that, due to their protective aragonite skeletons and quality of being rooted to the seafloor, these corals are exempt from many of the contamination and deterioration issues of other sample types. Yet challenges persist when trying to interpret coral-bound nitrogen in corals as proxies of their environment. Unlike other organisms, corals do not display a consistent ~3.5 ‰ trophic offset in N isotope ratio compared to their diet of POM (particulate organic matter). Instead, their offset is approximately ~8.5 ‰, which is 2-3 ‰ higher than the ubiquitous trophic offset of ~3.5‰, but it is unclear what factors are responsible for this difference. Although multiple theories exist, this study examines the potential influence of preferential uptake of suspended PON (particulate organic nitrogen) by corals as a source of higher d15N relative to sinking PON. Combined with the expected ~3.5 ‰ trophic offset, we hypothesized that because suspended PON has high δ15N, this preferential feeding could result in higher δ15N in corals. However, our results indicate that this is not the case. Instead, the unexpected offset could result from high δ15N in starting nitrate in addition to a higher trophic diet than expected. This study provides a starting point from which to pursue nitrate and zooplankton as determining factors in CB- δ15N

The need for the management of wolves — an open letter

The Southern Mountain and Boreal Woodland Caribou are facing extinction from increased predation, predominantly wolves (Canis lupus) and coyotes (Canis latrans). These predators are increasing as moose (Alces alces) and deer (Odocoileus spp). expand their range north with climate change. Mitigation endeavors will not be sufficient; there are too many predators. The critical habitat for caribou is the low predation risk habitat they select at calving: It is not old growth forests and climax lichens. The southern boundary of caribou in North America is not based on the presence of lichens but on reduced mammalian diversity. Caribou are just as adaptable as other cervids in their use of broadleaf seed plant as forage. Without predator management these woodland caribou will go extinct in our life time

An Introduction to Consumptive Use of Water in South Carolina

Effective water resource management requires understanding the supply of and the demand for water. In South Carolina, as in other places, water demand is often determined using total withdrawal volumes. However, the volume of water that is withdrawn can be significantly different from the volume that is actually consumed, which becomes unavailable for downstream uses. Water used for energy generation is commonly excluded from evaluations of total withdrawal volume because it is often assumed to be no or low consumptive use, meaning much of the withdrawn water is returned to the source and remains available for downstream uses. Additionally, energy production withdrawal volumes may be significantly higher than other sectors’ usage and make it difficult to further compare water use of other sectors. Consumptive use volumes are not readily available for South Carolina and can be challenging to determine. However, estimates of consumptive use could allow more meaningful comparisons between water use sectors’ impacts. The objective of this short communication is to briefly discuss data sources, outline two relatively simple methods for calculating consumptive use with available data, identify challenges and opportunities for additional research, and provide preliminary estimates of consumptive water use volumes per water use sectors in South Carolina. Expanded discussion of consumptive water use of thermoelectric energy generation is included due to the significant total water withdrawals and unique challenges with calculating consumptive use of this sector. These results inform water resource planning and identify additional research opportunities

The Buffalo of the North: Caribou (Rangifer tarandus) and Human Developments

The demography, movement, and behaviour patterns of eight caribou populations (Kaminuriak, Nelchina, Central Arctic, Fortymile, Porcupine, British Columbia, Newfoundland, and Snohetta) exposed to industrial activities or transportation corridors are reviewed. Behaviour patterns of caribou encountering transportation corridors are explainable in terms of adaptive responses to natural environmental features. There is no evidence that disturbance activities or habitat alteration have affected productivity. Transportation corridors have adversely affected caribou numbers by facilitating access by hunters. There are no examples where physical features of corridors or associated disturbances have affected numbers or productivity. Caribou apparently have a high degree of resilience to human disturbance, and seasonal movement patterns and extent of range occupancy appear to be a function of population size rather than of extrinsic disturbance. The carrying capacity of the habitat is based on the space caribou need to interact successfully with their natural predators. Caribou must not be prevented from crossing transportation corridors by the construction of physical barriers, by firing lines created by hunting activity along a corridor, or by intense harassment - a loss in usable space will ultimately result in reduced abundance.Key words: caribou (Rangifer tarandus), disturbance, wolves, predation, overharvest, accessMots clés: caribou (Rangifer tarandus), dérangement, loups, predation, surchasse, l'accès aux chasseur

Searching for a 10^(5-6) K gas component in clusters of galaxies

The far ultraviolet background images from the Galaxy Evolution Explorer were used to examine the reported diffuse 1056 K gas component in galaxy clusters. To remove the scattered starlight from dust component to the UV background the 100 micron images of Schlegel, Finkbeiner, and Davis were used. No confirmations are reported, with upper limits on the UV flux 1015 erg s1 cm2 °A1. This is many orders of magnitude above what would be expected from a blackbody at 107 K. The upper limits on ultraviolet flux are compared with ultraviolet emission from elliptical galaxies and the cluster’s X-ray luminosity. The inability to completely remove the dust component and the presence of residual emission from bright galaxies limited the results.Bergerud, Brandon. (2014). Searching for a 10^(5-6) K gas component in clusters of galaxies. Retrieved from the University Digital Conservancy, https://hdl.handle.net/11299/166538

EMV eller etablert merkevare? En kvantitativ analyse

Denne oppgaven tar utgangspunkt i en antagelse om at etablerte merkevarer reduserer opplevd risiko for forbrukeren, sammenliknet med dagligvarekjedenes egne merkevarer (EMV). Denne antakelsen legges til grunn for en studie av den økende andelen av EMVer som tilbys i norske dagligvarebutikker og av den konkurransen med allerede etablerte merkevarer som denne økningen skaper. For å motivere forbrukeren til å velge EMV, trass i den økte risikoen, er det rimelig å regne med at forbrukeren må tilbys en prisrabatt som kompensasjon. I denne bacheloroppgaven studerer jeg – for utvalgte produkter – hvor stor denne prisrabatten må være. Oppgaven søker å besvare følgende todelte problemstilling: 1. Avhenger kravet til prisrabatt for å velge EMV fremfor etablert merkevare av den opplevde risikoen ved det aktuelle produktet? 2. Avhenger kravet til prisrabatt av sosiale kjennetegn ved den enkelte forbruker? For å besvare denne problemstillingen benytter jeg en kvantitativ tilnærming. Jeg utvikler et sett av hypoteser, som deretter blir testet dels ved hjelp av regresjonsanalyse (OLS) og dels ved hjelp av «paired-sample» t-tester. Jeg studerer blant annet effekten av fem sosiale bakgrunnsvariabler: inntekt, kjønn, alder, utdanning og husholdningsstørrelse. Undersøkelsen og analysen jeg rapporterer i denne oppgaven er basert på et begrenset materiale, som dessuten lider av noen svakheter. Blant annet er antall respondenter begrenset. Det er heller ikke brukt sannsynlighetsutvelging. Det er derfor vanskelig å si hvor representativt utvalget er og i hvilken grad resultatene fra utvalget kan generaliseres til hele populasjonen av kunder i dagligvaremarkedet. Så langt resultatene rekker, tyder de imidlertid på at det har liten hensikt for kjedene å prøve å skreddersy prisrabatter for produkter rettet mot bestemte sosiale grupper. Bakgrunnsvariablene har liten eller ingen betydning for hvor stor prisrabatt som er nødvendig for å motivere kunden til å velge EMV. Resultatene peker derimot i retning av at størrelsen på prisrabatten må avpasses etter den opplevde risikoen som det enkelte produktet medfører for kundene. Spesielt tyder mine funn på at det fordres en høyere prisrabatt for produkter med høy risiko enn for produkter med lav risiko. Utfordringen for kjedene er dermed todelt: For det første må de estimere størrelsen på hvert produkts risiko. For det andre må de finne ut av hvor stor prisrabatt som må til for gitte nivåer på produktrisikoen. Litt spissformulert kan man kanskje si at min hovedkonklusjon er følgende: Kundenes krav til prisrabatt er påvirket av deres oppfatning av produktrisiko, men ikke av deres sosiale gruppetilhørighet