Theoretical and Experimental Analysis for Cleaning Ice Cores from EstisolTM 140 Drill Liquid

Featured ApplicationThis work gives indications for cleaning and preservation of ice cores, which will be drilled in Antarctica during the EU project Beyond EPICA Oldest Ice and provides general guidelines for ice drilling activities and preservation of ice cores.To reconstruct climate history of the past 1.5 Million years, the project: Beyond EPICA Oldest Ice (BEOI) will drill about 2700 m of ice core in East Antarctica (2021-2025). As drilling fluid, an aliphatic ester fluid, Estisol(TM) 140, will be used. Newly drilled ice cores will be retrieved from the drill soaked in fluid, and this fluid should be removed from the cores. Most of it will be vacuum-cleaned off in a Fluid Extraction Device and wiped off with paper towels. Based on our experiences in Greenland deep ice coring, most of the residual fluid can be removed by storing the cores openly on shelves in a ventilated room. After a week of "drying", the cores have a dry feel, handling them do not give "wet" gloves and they can easily be marked with lead pencils. This paper presents a theoretical investigation and some simple testing on the "drying" process. The rates of sublimation of ice and evaporation of fluid have been calculated at different temperatures. The calculations show that sublimation of the ice core should not occur, and that evaporation of fluid should be almost negligible. Our test results support these calculations, but also revealed significant fluid run-off and dripping, resulting in the removal of most of the fluid in a couple of days, independent of temperature and ventilation conditions. Finally, we discuss crucial factors that ensure optimal long-term ice core preservation in storage, such as temperature stability, defrosting cycles of freezers and open core storage versus storage of cores in insulated crates

Concentration of trace inorganic species in surface snow at NEEM, Greenland

第3回極域科学シンポジウム/第35回極域気水圏シンポジウム 11月29日（木） 国立国語研究所 ２階ロビ

Preadmission antidepressant use and bladder cancer: a population-based cohort study of stage at diagnosis, time to surgery, and surgical outcomes

BACKGROUND: Among cancer patients, prior antidepressant use has been associated with impaired survival. This could be due to differences in stage at diagnosis, in receipt of treatment, or in treatment complications. The purpose of this study was, therefore, to examine if preadmission antidepressant use in patients with bladder cancer is associated with tumor stage at diagnosis, rate of cystectomy, and surgical outcomes, including survival. METHODS: We performed a registry-based cohort study including all patients with incident invasive bladder cancer in Denmark 2005-2015. Exposure was defined as redemption of two or more antidepressant prescriptions one year before cancer diagnosis. We compared tumor stage using logistic regression, postsurgical inpatient length of stay using linear regression, and other outcomes using Cox regression. All results were adjusted for age, sex, comorbidity, and marital status. RESULTS: Among 10,427 bladder cancer patients, 10% were antidepressant users. At diagnosis, 51% of users and 52% of non-users had muscle-invasive disease. However, upon adjustment for age, sex, comorbidity, and marital status, users had lower odds of muscle-invasive disease (adjusted odds ratio 0.86 (95% confidence interval (CI) 0.74-0.99)). Among patients with muscle-invasive disease, fewer users than non-users had surgery within three months (15% vs. 24%, adjusted hazard ratio (aHR) 0.75 (95% CI 0.59-0.95)). Of 2532 patients undergoing surgery, 6% were antidepressant users. Postsurgical inpatient length of stay did not differ between users and non-users. The 30-day cumulative incidence of readmission was higher for users (41% vs. 33%, aHR 1.33 (95% CI 1.05-1.67)), while the 90-day incidence of postoperative procedures was 44% for users and 38% for non-users (aHR 1.18 (95% CI 0.93-1.51)). One-year mortality was comparable in users (15%) and non-users (14%). CONCLUSIONS: Antidepressant use in bladder cancer patients was associated with less advanced stage at diagnosis and lower rate of cystectomy. After cystectomy, users had higher rate of readmission and postoperative procedures than non-users, but we found no difference in length of stay or one-year mortality. The results point to the importance of differentiated clinical care according to individual patient characteristics

Assessing the reproductive biology of the Greenland shark (Somniosus microcephalus)

The Greenland shark (Somniosus microcephalus, Squaliformes: Somniosidae) is a long-lived Arctic top predator, which in combination with the high historical and modern fishing pressures, has made it subject to increased scientific focus in recent years. Key aspects of reproduction are not well known as exemplified by sparse and contradictory information e.g. on birth size and number of pups per pregnancy. This study represents the first comprehensive work on Greenland shark reproductive biology based on data from 312 specimens collected over the past 60 years. We provide guidelines quantifying reproductive parameters to assess specific maturation stages, as well as calculate body length-at-maturity (TL50) which was 2.84±0.06 m for males and 4.19±0.04 m for females. From the available information on the ovarian fecundity of Greenland sharks as well as a meta-analysis of Squaliform reproductive parameters, we estimate up to 200–324 pups per pregnancy (depending on maternal size) with a body length-at-birth of 35–45 cm. These estimates remain to be verified by future observations from gravid Greenland sharks

Greenland Shark (<i>Somniosus microcephalus</i>) Stomach Contents and Stable Isotope Values Reveal an Ontogenetic Dietary Shift

Current knowledge on the feeding ecology of the Greenland shark (Somniosus microcephalus), a potential top predator in arctic marine ecosystems, is based on small sample sizes as well as narrow size ranges of sharks. Therefore, potential size-related feeding patterns remain poorly documented. Using stomach content data (N = 88) and stable isotope values of white muscle tissue (N = 40), this study evaluates the diet of sharks ranging in size from 81 to 474 cm (total length). The importance of prey categories (“Fish,” “Mammal,” “Squid,” “Crustacean,” and “Other”) was evaluated based on the reconstructed prey biomass of the stomach contents. Stable isotope values of δ13C and δ15N ranged between -14.4 to -19.9‰ and 11.8 to 17.2‰, respectively. The importance of each prey category was estimated by the Index of Relative Importance (IRI). Our findings suggest that the smallest Greenland sharks (200 cm) mainly feed on higher trophic level prey such as seals, epibenthic and benthic fishes including gadoids (Gadidae), skates (Rajidae), righteye flounders (Pleuronectidae), lumpfish (Cyclopteridae), wolffish (Anarhichadidae), and redfish (Sebastidae). Redfish were, however, only found to be important in the largest sharks sampled (>400 cm). In addition to demonstrating ontogenetic shifts in their feeding preferences, this study supports that Greenland sharks are capable of active predation on fast swimming seals and large fishes

Retrieving a common accumulation record from Greenland ice cores for the past 1800 years

Abstract. In the accumulation zone of the Greenland ice sheet the annual accumulation rate may be determined through identification of the annual cy-cle in the isotopic climate signal and other parameters that exhibit seasonal vari-ations. On an annual basis the accumulation rate in different Greenland ice cores is highly variable, and the degree of correlation between accumulation series from different ice cores is low. However, when using multi year averages of the dif-ferent accumulation records the correlation increases significantly. A statistical model has been developed to estimate the common climate signal in the differ-ent accumulation records through optimization of the ratio between the variance of the common signal and of the residual. Using this model a common Green-land accumulation record with five years resolution for the past 1800 years has been extracted. The record establishes a climatic record which implies that very dry conditions during the 13th century together with dry and cold spells dur-ing the 14th century may have put extra strain on the Norse population in Green-land and have contributed to their extinction