Northeastern Atlantic benthic foraminifera during the last 45,000 years: Changes in productivity seen from the bottom up

We studied benthic foraminifera from the last 45 kyr in the >63 mu m size fraction in Biogeochemical Ocean Flux Studies (BOFS) cores 5K (50 degrees 41.3'N, 21 degrees 51.9'W, depth 3547 m) and 14K (58 degrees 37.2'N, 19 degrees 26.2'W, depth 1756 m), at a time resolution of several hundreds to a thousand years. The deepest site showed the largest fluctuations in faunal composition, species richness, and benthic foraminiferal accumulation rates; the fluctuations resulted from changes in abundance of Epistominella exigua and Alabaminella weddellensis. In the present oceans, these species bloom opportunistically when a spring plankton bloom results in seasonal deposition of phytodetritus on the seafloor. The ''phytodetritus species'' had very low relative abundances and accumulation rates during the last glacial maximum. A strong increase in absolute and relative abundance of E. exigua and A weddellensis during deglaciation paralleled the decrease in abundance of the polar planktonic foraminifer Neogloboquadrina pachyderma (s), and the increase in abundance of warmer water planktonic species such as Globigerina bulloides. This strong increase in relative abundance of the ''phytodetritus species'' and the coeval increase in benthic foraminiferal accumulation rate were thus probably caused by an increase in the deposition of phytodetritus to the seafloor (and thus probably of surface productivity) when the polar front retreated to higher latitudes. The abundance of ''phytodetritus species'' decreased during the Younger Dryas, but not to the low levels of fully glacial conditions. During Heinrich events (periods of excessive melt-water formation and ice rafting) benthic accumulation rates were very low, as were the absolute and relative abundances of the ''phytodetritus species'', supporting suggestions that surface productivity was very low during these events. In both cores Pullenia and Cassidulina species were common during isotope stages 2, 3 and 4, as were bolivinid, buliminid and uvigerinid species. High relative abundances of these species have been interpreted as indicative either of sluggish deep water circulation or of high organic carbon fluxes to the seafloor. In our cores, relative abundances of these species are negatively correlated with benthic foraminiferal accumulation rates, and we can thus not interpret them as indicative of increased productivity during glacials. The percentage of these ''low oxygen'' species calculated on a ''phytodetritus species'' - free basis decreased slightly at deglaciation at 5K, but not at 14K. This suggests that decreased production of North Atlantic Deep Water during the last glacial might have slightly affected benthic foraminiferal faunas in the eastern North Atlantic at 3547 m depth, but not at 1756 m. In conclusion, major changes in deep-sea benthic foraminiferal faunas over the last 45,000 years in our cores from the northeastern Atlantic were the result of changes in surface water productivity, not of changes in deep water circulation; productivity was lower during the glacial, probably because of extensive ice cover

An Update on Machine Learning in Neuro-oncology Diagnostics

Imaging biomarkers in neuro-oncology are used for diagnosis, prognosis and treatment response monitoring. Magnetic resonance imaging is typically used throughout the patient pathway because routine structural imaging provides detailed anatomical and pathological information and advanced techniques provide additional physiological detail. Following image feature extraction, machine learning allows accurate classification in a variety of scenarios. Machine learning also enables image feature extraction de novo although the low prevalence of brain tumours makes such approaches challenging. Much research is applied to determining molecular profiles, histological tumour grade and prognosis at the time that patients first present with a brain tumour. Following treatment, differentiating a treatment response from a post-treatment related effect is clinically important and also an area of study. Most of the evidence is low level having been obtained retrospectively and in single centres.Comment: arXiv admin note: substantial text overlap with arXiv:1910.0744

Does cognitive ability influence responses to the Warwick-Edinburgh Mental Well-Being Scale?

It has been suggested that how individuals respond to self-report items relies on cognitive processing. We hypothesized that an individual's level of cognitive ability may influence these processes such that, if there is a hierarchy of items within a particular questionnaire, as demonstrated by Mokken scaling, the strength of that hierarchy will vary according to cognitive ability. Using data on 8,643 men and women from the National Child Development Survey (1958 birth cohort; Power, & Elliott, 2006), we investigated, using Mokken scaling, whether the 14 items that make up the Warwick-Edinburgh Mental Well-Being Scale (Tennant et al., 2007)-completed when the participants were 50 years of age-form a hierarchy and whether that hierarchy varied according to cognitive ability at age 11 years. Among the sample as a whole, we found a moderately strong unidimensional hierarchy of items (Loevinger's coefficient [H] = 0.48). We split participants into 3 groups according to cognitive ability and analyzed the Mokken scaling properties of each group. Only the medium and high cognitive ability groups had acceptable (?0.3) invariant item ordering (assessed using the HT statistic). This pattern was also found when the 3 cognitive ability groups were assessed within men and women separately. Greater attention should be paid to the content validity of questionnaires to ensure they are applicable across the spectrum of mental ability

Typescript of Thomas Eyre Booth\u27s Remembrances of Father (Edmund Booth Deaf Pioneer and California Gold Miner)

https://scholarlycommons.pacific.edu/grcc/1041/thumbnail.jp

Misconceptions in ancient and medieval history.

Thesis (Ed.M.)--Boston Universit

Exploring your Inner Hades: DNA as Mortuary Archaeology

Two revolutions in using human genetics to investigate the past are beginning to have a profound effect on how the public regard heritage and their connection to it. Direct-to-consumer genetic ancestry tests (GATs) are becoming a popular way for the public to explore their familial history and ancestry. Major advances in ancient DNA methods mean that the field is beginning to live up to its early promise. Both of these analyses can be considered forms of public mortuary archaeology in how they are perceived to provide an individual an interface with their recent and more ancient ancestors, their own personal Hades, referring to the Ancient Greek home of the dead. GATs are useful for resolving genealogy and determining the origins of an individual’s recent ancestors, but have been criticized for reifying differences between populations, failing to give clear guidance on how they should be interpreted and making exaggerated links to historic groups of people that are at the heart of genetically determinist nationalistic origin myths. Recent palaeogenomic studies of prehistoric Europeans have found evidence for population discontinuity that will have repercussions for the public’s perception of archaeological mortuary sites and the communities who built them. Public archaeologists are going to have to engage increasingly with these types of data to combat the misappropriation of genetic results in defining rights and affinities to archaeological heritage

Guiding Attention in Controlled Real-World Environments

The ability to direct a viewer\u27s attention has important applications in computer graphics, data visualization, image analysis, and training. Existing computer-based gaze manipulation techniques, which direct a viewer\u27s attention about a display, have been shown to be effective for spatial learning, search task completion, and medical training applications. This work extends the concept of gaze manipulation beyond digital imagery to include controlled, real-world environments. This work addresses the main challenges in guiding attention to real-world objects: determining what object the viewer is currently paying attention to, and providing (projecting) a visual cue on a different part of the scene in order to draw the viewer\u27s attention there. The developed system consists of a pair of eye-tracking glasses to determine the viewer\u27s gaze location, and a projector to create the visual cue in the physical environment. The results of a user study show that the system is effective for directing a viewer\u27s gaze in the real-world. The successful implementation has applicability in a wide range of instructional environments, including pilot training and driving simulators

Rovibrational Resonance Effects In Collision-Induced Electronic Energy Transfer: I2(E,v=0-2)+CF4

Collisions of I-2 in the E(0(g)(+)) electronic state with CF4 molecules induce electronic energy transfer to the nearby D, beta, and D-\u27 ion-pair states. Simulations of dispersed fluorescence spectra reveal collision-induced electronic energy transfer rate constants and final vibrational state distributions within each final electronic state. In comparison with earlier reports on I-2(upsilon(E)=0-2) collisions with He or Ar atoms, we find markedly different dynamics when I-2, excited to the same rovibronic states, collides with CF4. Final vibrational state distributions agree with the associated Franck-Condon factors with the initially prepared state to a greater degree than those found with He or Ar collision partners and suggest that internal degrees of freedom in the CF4 molecule represent a substantial means for accepting the accompanying loss of I-2 vibronic energy. Comparison of the E -\u3e D transfer of I-2 excited to the J=23 and J=55 levels of the upsilon(E)=0 state reveals the onset of specific, nonstatistical dynamics as the available energy is increased above the threshold for excitation of the low frequency nu(2) bending mode of CF4. (c) 2006 American Institute of Physics