Arctic sea ice trends and narwhal vulnerability

Conservation measures related to global climate change require that species vulnerability be incorporated into population risk models, especially for those that are highly susceptible to rapid or extreme changes due to specialized adaptation. In the case of Arctic cetaceans, effects of climate change on habitat and prey availability have been subject to intense speculation. Climate perturbations may have significant impacts on the fitness and success of this group, yet measuring these parameters for conservation purposes is complicated by remote and offshore preferences. The narwhal (Monodon monoceros) in Baffin Bay occupies a habitat where reversed (increasing) regional sea ice trends have been detected over 50 years. We used a combination of long-term narwhal satellite tracking data and remotely sensed sea ice concentrations to detect localized habitat trends and examine potential vulnerability. Spatial and temporal variability in the fraction of open water were examined on two narwhal wintering grounds between November and April, 1978-2001 using approximate sea ice concentrations derived from microwave SSMR/SSMI passive brightness temperatures. Less than 3% open water was available to narwhals between 15 January and 15 April, and reached minima of 0.5% open water at the end of March (125 km² out of a 25,000 km² area). Decreasing trends in the fraction of open water, together with increasing trends in interannual variability, were detected on both wintering grounds, significantly in northern Baffin Bay (−0.04% per year, SE 0.02). The limited number of leads and cracks available to narwhals during the winter, in combination with localized decreasing trends in open water and high site fidelity, suggests vulnerability to changes in Arctic sea ice conditions. Increasing risk of ice entrapments, many of which may go undetected in remote offshore areas, should be incorporated into population risk assessments as this may exceed the natural response capacity of the species.     

Crustacean Communities in Canada and Norway: Comparison of Species along A pH Gradient

Increased pH in acid lakes changes the crustacean fauna from communities dominated by acid-tolerant species to communities dominated by more acid-sensitive species. Studies from Canada (Killarney) and southeastern Norway (Østfold county) have demonstrated that planktonic and littoral crustaceans can be used as indicators of such recoveries. In both places the cladocerans Alona rustica and Acantholeberis curvirostris were found in acidic lakes, whereas Alona costata and the copepod Eucyclops macrurus were found in near neutral lakes. The calanoids Diaptomus minutus in North America and Eudiaptomus gracilis in Europe, both dominate in acidic water, and may ecologically be equivalent species. Sometimes the same species occur at different pH in the two continents. Bosmina longirostris and Alonella excisa may serve as examples, but a pertinent question is whether or not they are really the same species.     

The tree planting and protecting culture of cattle ranchers and small-scale agriculturalists in rural Panama: Opportunities for reforestation and land restoration

To examine the opportunities available for designing diverse tree planting and land restoration initiatives in agricultural landscapes that contain tropical dry forests, the tree planting and protecting practices of cattle ranchers and small-scale agriculturalists were examined in two study sites in rural Panama. Ninety-nine tree species were identified that they utilize, plant, or protect on their land, the majority of which are native to Panama. The farmers had diverse reasons for maintaining trees, including improving the environment, providing food and shade for cattle, and generating a source of wood for construction, furniture, and firewood. Most of the trees mentioned in the study provide multiple uses and values and the majority of farmers wanted to plant additional trees. Some differences in species preferences and motivations for planting and protecting trees were seen between sites, thereby suggesting that land restoration and tree planting projects should be site specific. Our data indicate that there are ample opportunities to increase native tree cover in our study sites and highlight the need to incorporate farmer input into project design, implementation, and evaluation as a necessary and continuous feature throughout projects.     

Comparison of cardiopulmonary effects of etorphine and thiafentanil administered as sole agents for immobilization of impala (Aepyceros melampus)

ObjectiveTo compare the cardiopulmonary effects of the opioids etorphine and thiafentanil for immobilization of impala.Study designTwo-way crossover, randomized study.AnimalsA group of eight adult female impala.MethodsImpala were given two treatments: 0.09 mg kg^–1 etorphine or 0.09 mg kg^–1 thiafentanil via remote dart injection. Time to recumbency, quality of immobilization and recovery were assessed. Respiratory rate, heart rate (HR), mean arterial blood pressure (MAP) and arterial blood gases were measured. A linear mixed model was used to analyse the effects of treatments, treatments over time and interactions of treatment and time (p < 0.05).ResultsTime to recumbency was significantly faster with thiafentanil (2.0 ± 0.8 minutes) than with etorphine (3.9 ± 1.6 minutes; p = 0.007). Both treatments produced bradypnoea, which was more severe at 5 minutes with thiafentanil (7 ± 4 breaths minute^–1) than with etorphine (13 ± 12 breaths minute^–1; p = 0.004). HR increased with both treatments but significantly decreased over time when etorphine (132 ± 17 to 82 ± 11 beats minute^–1) was compared with thiafentanil (113 ± 22 to 107 ± 36 beats minute^–1; p < 0.001). Both treatments caused hypertension which was more profound with thiafentanil (mean overall MAP = 140 ± 14 mmHg; p < 0.001). Hypoxaemia occurred with both treatments but was greater with thiafentanil [PaO₂ 37 ± 13 mmHg (4.9 kPa)] than with etorphine [45 ± 16 mmHg (6.0 kPa)] 5 minutes after recumbency (p < 0.001). After 30 minutes, PaO₂ increased to 59 ± 10 mmHg (7.9 kPa) with both treatments (p < 0.001).Conclusions and clinical relevanceThe shorter time to recumbency with thiafentanil may allow easier and faster retrieval in the field. However, thiafentanil caused greater hypertension, and ventilatory effects during the first 10 minutes, after administration.     

Geographical distribution and prevalence of tick‐borne encephalitis virus in questing Ixodes ricinus ticks and phylogeographic structure of the Ixodes ricinus vector in Norway

The tick‐borne encephalitis virus (TBEV), a zoonotic flaviviral infection, is endemic in large parts of Norway and Eurasia. Humans are mainly infected with TBEV via bites from infected ticks. In Norway, the main geographical distribution of ticks is along the Norwegian coastline from southeast (~59°N) and up to the southern parts of Nordland County (~65°N). In this study, we collected ticks by flagging along the coast from Østfold County to Nordland County. By whole‐genome sequencing of the mitochondrial genome of Ixodes ricinus, the phylogenetic tree suggests that there is limited phylogeographic structure both in Norway and in Europe. The overall TBEV prevalence is 0.3% for nymphs and 4.3% for adults. The highest estimated TBEV prevalence in adult ticks was detected in Rogaland and Vestfold County, while for nymphs it is highest in Vestfold, Vest‐Agder and Rogaland. The present work is one of the largest studies on distribution and prevalence of TBEV in ticks in Scandinavia, showing that the virus is wider distributed in Norway than previously anticipated.     

The magnitude and duration of Late Ordovician-Early Silurian glaciation

Understanding ancient climate changes is hampered by the inability to disentangle trends in ocean temperature from trends in continental ice volume. We used carbonate "clumped" isotope paleothermometry to constrain ocean temperatures, and thereby estimate ice volumes, through the Late Ordovician-Early Silurian glaciation. We find tropical ocean temperatures of 32° to 37°C except for short-lived cooling by ~5°C during the final Ordovician stage. Evidence for ice sheets spans much of the study interval, but the cooling pulse coincided with a glacial maximum during which ice volumes likely equaled or exceeded those of the last (Pleistocene) glacial maximum. This cooling also coincided with a large perturbation of the carbon cycle and the Late Ordovician mass extinction.     

Addition of Glucose Oxidase for the Improvement of Refrigerated Dough Quality

Refrigerated dough encompasses a wide range of products and is a popular choice for consumers. Two of the largest problems that occur during refrigerated dough storage are dough syruping and loss of dough strength. The goal of this study was to evaluate glucose oxidase as an additive to refrigerated dough with the purpose of maintaining dough strength and retarding dough syruping. Refrigerated dough was evaluated for the degree of dough syruping (DDS), dough strength, rheological characteristics, baking quality, and protein quality. The addition of glucose oxidase at 10 mg/kg was able to significantly (P < 0.05) reduce dough syruping and maintain the strength of the dough. Addition of glucose oxidase at 5 and 25 mg/kg was not able to reduce the level of dough syruping at a satisfactory level. Degradation of protein was found to occur during storage of refrigerated dough. DDS had a negative correlation (r = –0.60 to –0.94) to the level of polymeric proteins and a positive correlation (r = 0.60 to 0.98) to the low‐molecular‐weight proteins. Overall, glucose oxidase at 10 mg/kg can improve refrigerated dough quality by reducing dough syruping and maintaining dough strength.     

Breed-specific incidence rates of canine primary bone tumors--a population based survey of dogs in Norway

This is one of few published population-based studies describing breed specific rates of canine primary bone tumors. Incidence rates related to dog breeds could help clarify the impact of etiological factors such as birth weight, growth rate, and adult body weight/height on development of these tumors. The study population consisted of dogs within 4 large/giant breeds; Irish wolfhound (IW), Leonberger (LB), Newfoundland (NF), and Labrador retriever (LR), born between January 1st 1989 and December 31st 1998. Questionnaires distributed to owners of randomly selected dogs--fulfilling the criteria of breed, year of birth, and registration in the Norwegian Kennel Club--constituted the basis for this retrospective, population-based survey. Of the 3748 questionnaires received by owners, 1915 were completed, giving a response rate of 51%. Forty-three dogs had been diagnosed with primary bone tumors, based upon clinical examination and x-rays. The breeds IW and LB, with 126 and 72 cases per 10 000 dog years at risk (DYAR), respectively, had significantly higher incidence rates of primary bone tumors than NF and LR (P < 0.0001). Incidence rates for the latter were 11 and 2 cases per 10 000 DYAR, respectively. Pursuing a search for risk factors other than body size/weight is supported by the significantly different risks of developing primary bone tumors between similarly statured dogs, like NF and LB, observed in this study. Defining these breed-specific incidence rates enables subsequent case control studies, ultimately aiming to identify specific etiological factors for developing primary bone tumors.