Exceptionally Large Icebergs and Ice Islands in Eastern Canadian Waters: A Review of Sightings from 1900 to Present

A review of post-1900 sightings of ice islands and exceptionally large icebergs in eastern Canadian waters between Baffin Bay and the Grand Banks demonstrates that current estimates of the maximum expected iceberg lengths are below many of the reported values. Analysis of these sightings reveals that for the area south of 55 N the frequency of sightings and the maximum reported lengths were greater during the first half of this century than during the period 1950-90. However, recent sightings in 1991 demonstrate that exceptionally large icebergs should still be considered when designing fixed offshore structures for the Grand Banks or Labrador Shelf.Key words: icebergs, ice islands, Labrador Sea, Grand Banks, offshore oilUne recension des observations postérieures à 1900 concernant les îles de glace et les icebergs de taille exceptionnelle dans les eaux canadiennes orientales situées entre la baie de Baffin et les Grands Bancs de Terre-Neuve révèle que les estimations courantes des longueurs maximales d'icebergs escomptées se situent en dessous de bien des valeurs rapportées. Une analyse de ces observations montre que pour la zone au sud du 55° N, la fréquence des observations et les longueurs maximales rapportées étaient plus grandes durant la première moitié de ce siècle que durant la période allant de 1950 à 1990. De récentes observations faites en 1991 révèlent cependant que la conception des structures fixes en mer sur les Grands Bancs ou sur le plateau continental du Labrador devrait toujours tenir compte des icebergs de taille exceptionnelle.Mots clés : icebergs, îles de glace, mer du Labrador, Grands Bancs, pétrole exploité en me

Recent Year-to-year Variations in Seasonal Temperatures and Sea Ice Conditions in the Eastern Canadian Arctic

Mean summer and winter temperatures for the 1957-1978 period have been analyzed for four eastern Arctic stations. Standard deviations on the order of 3° C in winter and 10° C in summer indicate the magnitude of the interannual variations, and these departures are found to be synchronous over the region. Several indices of sea ice severity also show significant year-to-year variations, but these are not spatially coherent. Relationships between climatic parameters and sea ice are examined in order to explain these differences

Bostonia. Volume 6

Founded in 1900, Bostonia magazine is Boston University's main alumni publication, which covers alumni and student life, as well as university activities, events, and programs

Referees’ Decision Making Behavior and the Sport Home Advantage Phenomenon

The aim of this investigation was to examine the decision making behavior of soccer officials (referees) in English Premiership matches to establish whether a bias, as perceived by the media and professional players, does or does not exist. Using notational analysis, this investigation used three trained professional soccer referees to assess the decisions made by match-day officials in favor of home and away teams during the entirety of ten-matched Premiership soccer fixtures. Results revealed a non-significant trend, x2 = .843, p > .05, where the number of decisions awarded by the referees favored the home team. However, significant differences were observed in the number of contentious and incorrect / missed decisions awarded in favor of the home teams compared to away teams, χ2 = 4.17, p < .05 and χ2 = 3.86, p < .05, respectively. Conclusions from this investigation indicate that soccer referees exhibit bias in favor of home teams and suggest that referee decision making behavior may be one mechanistic explanation of the home advantage phenomenon in soccer

The fairness, predictive validity and acceptability of multiple mini interview in an internationally diverse student population--a mixed methods study

BACKGROUND: International medical students, those attending medical school outside of their country of citizenship, account for a growing proportion of medical undergraduates worldwide. This study aimed to establish the fairness, predictive validity and acceptability of Multiple Mini Interview (MMI) in an internationally diverse student population. METHODS: This was an explanatory sequential, mixed methods study. All students in First Year Medicine, National University of Ireland Galway 2012 were eligible to sit a previously validated 10 station MMI. Quantitative data comprised: demographics, selection tool scores and First Year Assessment scores. Qualitative data comprised separate focus groups with MMI Assessors, EU and Non-EU students. RESULTS: 109 students participated (45% of class). Of this 41.3% (n = 45) were Non-EU and 35.8% (n = 39) did not have English as first language. Age, gender and socioeconomic class did not impact on MMI scores. Non-EU students and those for whom English was not a first language achieved significantly lower scores on MMI than their EU and English speaking counterparts (difference in mean 11.9% and 12.2% respectively, P<0.001). MMI score was associated with English language proficiency (IELTS) (r = 0.5, P<0.01). Correlations emerged between First Year results and IELTS (r = 0.44; p = 0.006; n = 38) and EU school exit exam (r = 0.52; p<0.001; n = 56). MMI predicted EU student OSCE performance (r = 0.27; p = 0.03; n = 64). In the analysis of focus group data two overarching themes emerged: Authenticity and Cultural Awareness. MMI was considered a highly authentic assessment that offered a deeper understanding of the applicant than traditional tools, with an immediate relevance to clinical practice. Cultural specificity of some stations and English language proficiency were seen to disadvantage international students. Recommendations included cultural awareness training for MMI assessors, designing and piloting culturally neutral stations, lengthening station duration and providing high quality advance information to candidates. CONCLUSION: MMI is a welcome addition to assessment armamentarium for selection, particularly with regard to stakeholder acceptability. Understanding the mediating and moderating influences for differences in performance of international candidates is essential to ensure that MMI complies with the metrics of good assessment practice and principles of both distributive and procedural justice for all applicants, irrespective of nationality and cultural background

Increased parental effort fails to buffer the cascading effects of warmer seas on common guillemot demographic rates

Research Funding Natural Environment Research Council Award. Grant Number: NE/R016429/1 UK-SCAPE Programme Delivering National Capability Joint Nature Conservation Committee EU ‘The Effect of Large-scale Industrial Fisheries On Non-Target Species’ FP5 Project ‘Interactions between the Marine environment, PREdators and Prey: Implications for Sustainable Sandeel Fisheries’. Grant Numbers: MS21-013, Q5RS-2000-30864 Ministry of Universities-University of ValenciaPeer reviewedPublisher PD

Community-wide decline in the occurrence of lesser sandeels Ammodytes marinus in seabird chick diets at a North Sea colony

Many pelagic marine ecosystems have a wasp-waist trophic structure characterised by low diversity of mid-trophic species, typically small, shoaling forage fish that are eaten by a wide range of top predators. In the North Sea, this mid-trophic position is occupied by the lesser sandeel Ammodytes marinus. Over the last 30-40 yr, the abundance and length-at-age of sandeels have declined, but information on concurrent changes in the diets of seabird communities is scarce. We used data on chick diet composition, sandeel length-at-age and energy density collected at a colony in the western North Sea from 1973-2015, to test for dietary shifts in this seabird community during a period when a local sandeel fishery opened, operated and was closed. We found a long-term decline in the overall importance (measured as the frequency of occurrence and proportion of biomass in diet samples) of sandeels, particularly 1+ group fish. However, there were species-specific differences such that the overall decline in sandeels was strongest in common guillemots Uria aalge, while the shift from 1+ group to 0 group sandeels was apparent in all species except European shags Phalacrocorax aristotelis. Community-level differences were also apparent in the alternative prey to sandeels, with with common guillemot, razorbill Alca torda, Atlantic puffin Fratercula arctica, and black-legged kittiwake Rissa tridactyla chicks being fed clupeids, predominantly sprat Sprattus sprattus, while shag chicks received a wide range of benthic fish species. There was also evidence for a decline in the quality of sandeels fed to chicks with significant decreases in length-at-age of 0 group and 1+ group. However, there was no significant annual variation in the energy density of sandeels except for 2004, when values were exceptionally low. Neither the opening nor the closing of the sandeel fishery had any detectable effect on chick diet composition, sandeel length or sandeel energy density. Overall, our results suggest marked community-level changes in seabird diet composition over the last 3 decades that may reflect long-term declines in the abundance and quality of their principal prey

Cell-free (RNA) and cell-associated (DNA) HIV-1 and postnatal transmission through breastfeeding

&lt;p&gt;Introduction - Transmission through breastfeeding remains important for mother-to-child transmission (MTCT) in resource-limited settings. We quantify the relationship between cell-free (RNA) and cell-associated (DNA) shedding of HIV-1 virus in breastmilk and the risk of postnatal HIV-1 transmission in the first 6 months postpartum.&lt;/p&gt; &lt;p&gt;Materials and Methods - Thirty-six HIV-positive mothers who transmitted HIV-1 by breastfeeding were matched to 36 non-transmitting HIV-1 infected mothers in a case-control study nested in a cohort of HIV-infected women. RNA and DNA were quantified in the same breastmilk sample taken at 6 weeks and 6 months. Cox regression analysis assessed the association between cell-free and cell-associated virus levels and risk of postnatal HIV-1 transmission.&lt;/p&gt; &lt;p&gt;Results - There were higher median levels of cell-free than cell-associated HIV-1 virus (per ml) in breastmilk at 6 weeks and 6 months. Multivariably, adjusting for antenatal CD4 count and maternal plasma viral load, at 6 weeks, each 10-fold increase in cell-free or cell-associated levels (per ml) was significantly associated with HIV-1 transmission but stronger for cell-associated than cell-free levels [2.47 (95% CI 1.33–4.59) vs. aHR 1.52 (95% CI, 1.17–1.96), respectively]. At 6 months, cell-free and cell-associated levels (per ml) in breastmilk remained significantly associated with HIV-1 transmission but was stronger for cell-free than cell-associated levels [aHR 2.53 (95% CI 1.64–3.92) vs. 1.73 (95% CI 0.94–3.19), respectively].&lt;/p&gt; &lt;p&gt;Conclusions - The findings suggest that cell-associated virus level (per ml) is more important for early postpartum HIV-1 transmission (at 6 weeks) than cell-free virus. As cell-associated virus levels have been consistently detected in breastmilk despite antiretroviral therapy, this highlights a potential challenge for resource-limited settings to achieve the UNAIDS goal for 2015 of eliminating vertical transmission. More studies would further knowledge on mechanisms of HIV-1 transmission and help develop more effective drugs during lactation.&lt;/p&gt

Temporal scaling phenomena in groundwater-floodplain systems using robust detrended fluctuation analysis

In order to determine objectively the fractal behaviour of a time series, and to facilitate potential future attempts to assess model performance by incorporating fractal behaviour, a multi-order robust detrended fluctuation analysis (r-DFAn) procedure is developed herein. The r-DFAn procedure allows for robust and automated quantification of mono-fractal behaviour. The fractal behaviour is quantified with three parts: a global scaling exponent, crossovers, and local scaling exponents. The robustness of the r-DFAn procedure is established by the systematic use of robust regression, piecewise linear regression, Analysis of Covariance (ANCOVA) and Multiple Comparison Procedure to determine statistically significant scaling exponents and optimum crossover locations. The MATLAB code implementing the r-DFAn procedure has also been open sourced to enable reproducible results. r-DFAn will be illustrated on a synthetic signal after which is used to analyse high-resolution hydrologic data; although the r-DFAn procedure is not limited to hydrological or geophysical time series. The hydrological data are 4 year-long datasets (January 2012 to January 2016) of 1-min groundwater level, river stage, groundwater and river temperature, and 15-min precipitation and air temperature, at Wallingford, UK. The datasets are analysed in both time and fractal domains. The study area is a shallow riparian aquifer in hydraulic connection to River Thames, which traverses the site. The unusually high resolution datasets, along with the responsive nature of the aquifer, enable detailed examination of the various data and their interconnections in both time- and fractal-domains

Considering the Case for Biodiversity Cycles: Reexamining the Evidence for Periodicity in the Fossil Record

Medvedev and Melott (2007) have suggested that periodicity in fossil biodiversity may be induced by cosmic rays which vary as the Solar System oscillates normal to the galactic disk. We re-examine the evidence for a 62 million year (Myr) periodicity in biodiversity throughout the Phanerozoic history of animal life reported by Rohde & Mueller (2005), as well as related questions of periodicity in origination and extinction. We find that the signal is robust against variations in methods of analysis, and is based on fluctuations in the Paleozoic and a substantial part of the Mesozoic. Examination of origination and extinction is somewhat ambiguous, with results depending upon procedure. Origination and extinction intensity as defined by RM may be affected by an artifact at 27 Myr in the duration of stratigraphic intervals. Nevertheless, when a procedure free of this artifact is implemented, the 27 Myr periodicity appears in origination, suggesting that the artifact may ultimately be based on a signal in the data. A 62 Myr feature appears in extinction, when this same procedure is used. We conclude that evidence for a periodicity at 62 Myr is robust, and evidence for periodicity at approximately 27 Myr is also present, albeit more ambiguous.Comment: Minor modifications to reflect final published versio