Dissociating visuo-spatial and verbal working memory: It’s all in the features

Echoing many of the themes of the seminal work of Atkinson and Shiffrin (1968), this paper uses the Feature Model (Nairne, 1988, 1990; Neath & Nairne, 1995) to account for performance in working memory tasks. The Brooks verbal and visuo-spatial matrix tasks were performed alone, with articulatory suppression, or with a spatial suppression task; the results produced the expected dissociation. We used Approximate Bayesian Computation techniques to fit the Feature Model to the data and showed that the similarity-based interference process implemented in the model accounted for the data patterns well. We then fit the model to data from Guérard and Tremblay (2008); the latter study produced a double dissociation while calling upon more typical order reconstruction tasks. Again, the model performed well. The findings show that a double dissociation can be modelled without appealing to separate systems for verbal and visuo-spatial processing. The latter findings are significant as the Feature Model had not been used to model this type of dissociation before; importantly, this is also the first time the model is quantitatively fit to data. For the demonstration provided here, modularity was unnecessary if two assumptions were made: (1) the main difference between spatial and verbal working memory tasks is the features that are encoded; (2) secondary tasks selectively interfere with primary tasks to the extent that both tasks involve similar features. It is argued that a feature-based view is more parsimonious (see Morey, 2018) and offers flexibility in accounting for multiple benchmark effects in the field

Cause and Possible Treatments of Foot Lesions in Captive Syrian Hamsters (Mesocricetus auratus)

Syrian hamsters (Mesocricetus auratus) run extensively in exercise wheels. This running may cause paw lesions. Three treatments of these wounds (topical application of vitamin E, wheel blocking, and a combination of both) were compared using both sexes. A pretreatment period with or without wheels lasted 15 days and the ensuing treatment period lasted 45 days. At the end of the pre-treatment period, none of the animals without wheels had paw wounds, whereas at least 75% of the females and 100% of the males with wheels did. Females had fewer and smaller wounds than males at this point. At the end of the treatment period, no effect of vitamin E could be discerned, but significant wound healing occurred after wheel blocking in both males and females. Wheel blocking is an easy way to prevent or treat paw wounds, but it presents problems in terms of animal welfare, as wheels are an important cage enrichment for hamsters

Genetic diversity and dynamics of the Noir Marron settlement in French Guyana : A study combining mitochondrial DNA, Y chromosome and HTLV-1 genotyping [Abstract]

The Noir Marron are the direct descendants of thousands of African slaves deported to the Guyanas during the Atlantic Slave Trade and later escaped mainly from Dutch colonial plantations. Six ethnic groups are officially recognized, four of which are located in French Guyana: the Aluku, the Ndjuka, the Saramaka, and the Paramaka. The aim of this study was: (1) to determine the Noir Marron settlement through genetic exchanges with other communities such as Amerindians and Europeans; (2) to retrace their origins in Africa. Buffy-coat DNA from 142 Noir Marron, currently living in French Guyana, were analyzed using mtDNA (typing of SNP coding regions and sequencing of HVSI/II) and Y chromosomes (typing STR and SNPs) to define their genetic profile. Results were compared to an African database composed by published data, updated with genotypes of 82 Fon from Benin, and 128 Ahizi and 63 Yacouba from the Ivory-Coast obtained in this study for the same markers. Furthermore, the determination of the genomic subtype of HTLV-1 strains (env gp21 and LTR regions), which can be used as a marker of migration of infected populations, was performed for samples from 23 HTLV-1 infected Noir Marron and compared with the corresponding database. MtDNA profiles showed a high haplotype diversity, in which 99% of samples belonged to the major haplogroup L, frequent in Africa. Each haplotype was largely represented on the West African coast, but notably higher homologies were obtained with the samples present in the Gulf of Guinea. Y Chromosome analysis revealed the same pattern, i.e. a conservation of the African contribution to the Noir Marron genetic profile, with 98% of haplotypes belonging to the major haplogroup E1b1a, frequent in West Africa. The genetic diversity was higher than those observed in African populations, proving the large Noir Marron’s fatherland, but a predominant identity in the Gulf of Guinea can be suggested. Concerning HTLV-1 genotyping, all the Noir Marron strains belonged to the large Cosmopolitan A subtype. However, among them 17/23 (74%) clustered with the West African clade comprizing samples originating from Ivory-Coast, Ghana, Burkina-Fasso and Senegal, while 3 others clustered in the Trans-Sahelian clade and the remaining 3 were similar to strains found in individuals in South America. Through the combined analyses of three approaches, we have provided a conclusive image of the genetic profile of the Noir Marron communities studied. The high degree of preservation of the African gene pool contradicts the expected gene flow that would correspond to the major cultural exchanges observed between Noir Marron, Europeans and Amerindians. Marital practices and historical events could explain these observations. Corresponding to historical and cultural data, the origin of the ethnic groups is widely dispatched throughout West Africa. However, all results converge to suggest an individualization from a major birthplace in the Gulf of Guinea

Episodes of Early Pleistocene West Antarctic Ice Sheet Retreat Recorded by Iceberg Alley Sediments

Ice loss in the Southern Hemisphere has been greatest over the past 30 years in West Antarctica. The high sensitivity of this region to climate change has motivated geologists to examine marine sedimentary records for evidence of past episodes of West Antarctic Ice Sheet (WAIS) instability. Sediments accumulating in the Scotia Sea are useful to examine for this purpose because they receive iceberg-rafted debris (IBRD) sourced from the Pacific- and Atlantic-facing sectors of West Antarctica. Here we report on the sedimentology and provenance of the oldest of three cm-scale coarse-grained layers recovered from this sea at International Ocean Discovery Program Site U1538. These layers are preserved in opal-rich sediments deposited ∼1.2 Ma during a relatively warm regional climate. Our microCT-based analysis of the layer's in-situ fabric confirms its ice-rafted origin. We further infer that it is the product of an intense but short-lived episode of IBRD deposition. Based on the petrography of its sand fraction and the Phanerozoic 40Ar/39Ar ages of hornblende and mica it contains, we conclude that the IBRD it contains was likely sourced from the Weddell Sea and/or Amundsen Sea embayment(s) of West Antarctica. We attribute the high concentrations of IBRD in these layers to “dirty” icebergs calved from the WAIS following its retreat inland from its modern grounding line. These layers also sit at the top of a ∼366-m thick Pliocene and early Pleistocene sequence that is much more dropstone-rich than its overlying sediments. We speculate this fact may reflect that WAIS mass-balance was highly dynamic during the ∼41-kyr (inter)glacial world.Postprin

Plasmodium falciparum population dynamics in a cohort of pregnant women in Senegal

<p>Abstract</p> <p>Background</p> <p>Pregnant women acquire protective antibodies that cross-react with geographically diverse placental <it>Plasmodium falciparum </it>isolates, suggesting that surface molecules expressed on infected erythrocytes by pregnancy-associated malaria (PAM) parasites have conserved epitopes and, that designing a PAM vaccine may be envisaged. VAR2CSA is the main candidate for a pregnancy malaria vaccine, but vaccine development may be complicated by its sequence polymorphism.</p> <p>Methods</p> <p>The dynamics of <it>P. falciparum </it>genotypes during pregnancy in 32 women in relation to VAR2CSA polymorphism and immunity was determined. The polymorphism of the <it>msp2 </it>gene and five microsatellites was analysed in consecutive parasite isolates, and the <it>DBL5ε + Interdomain 5 </it>(<it>Id5</it>) part of the <it>var2csa </it>gene of the corresponding samples was cloned and sequenced to measure variation.</p> <p>Results</p> <p>In primigravidae, the multiplicity of infection in the placenta was associated with occurrence of low birth weight babies. Some parasite genotypes were able to persist over several weeks and, still be present in the placenta at delivery particularly when the host anti-VAR2CSA antibody level was low. Comparison of diversity among genotyping markers confirmed that some PAM parasites may harbour more than one <it>var2csa </it>gene copy in their genome.</p> <p>Conclusions</p> <p>Host immunity to VAR2CSA influences the parasite dynamics during pregnancy, suggesting that the acquisition of protective immunity requires pre-exposure to a limited number of parasite variants. Presence of highly conserved residues in surface-exposed areas of the VAR2CSA immunodominant DBL5ε domain, suggest its potential in inducing antibodies with broad reactivity.</p

Expedition 382 Preliminary Report: Iceberg Alley and Subantarctic Ice and Ocean Dynamics

This is the final version. Available from International Ocean Discovery Program via the DOI in this record. International Ocean Discovery Program (IODP) Expedition 382, Iceberg Alley and Subantarctic Ice and Ocean Dynamics, investigated the long-term climate history of Antarctica, seeking to understand how polar ice sheets responded to changes in insolation and atmospheric CO2 in the past and how ice sheet evolution influenced global sea level and vice versa. Five sites (U1534–U1538) were drilled east of the Drake Passage: two sites at 53.2°S at the northern edge of the Scotia Sea and three sites at 57.4°–59.4°S in the southern Scotia Sea. We recovered continuously deposited late Neogene sediment to reconstruct the past history and variability in Antarctic Ice Sheet (AIS) mass loss and associated changes in oceanic and atmospheric circulation. The sites from the southern Scotia Sea (Sites U1536–U1538) will be used to study the Neogene flux of icebergs through “Iceberg Alley,” the main pathway along which icebergs calved from the mar- gin of the AIS travel as they move equatorward into the warmer wa- ters of the Antarctic Circumpolar Current (ACC). In particular, sediments from this area will allow us to assess the magnitude of iceberg flux during key times of AIS evolution, including the following: • The middle Miocene glacial intensification of the East Antarctic Ice Sheet, • The mid-Pliocene warm period, • The late Pliocene glacial expansion of the West Antarctic Ice Sheet, • The mid-Pleistocene transition (MPT), and • The “warm interglacials” and glacial terminations of the last 800 ky. We will use the geochemical provenance of iceberg-rafted detritus and other glacially eroded material to determine regional sources of AIS mass loss. We will also address interhemispheric phasing of ice sheet growth and decay, study the distribution and history of land-based versus marine-based ice sheets around the continent over time, and explore the links between AIS variability and global sea level. By comparing north–south variations across the Scotia Sea be- tween the Pirie Basin (Site U1538) and the Dove Basin (Sites U1536 and U1537), Expedition 382 will also deliver critical information on how climate changes in the Southern Ocean affect ocean circulation through the Drake Passage, meridional overturning in the region, water mass production, ocean–atmosphere CO2 transfer by wind- induced upwelling, sea ice variability, bottom water outflow from the Weddell Sea, Antarctic weathering inputs, and changes in oceanic and atmospheric fronts in the vicinity of the ACC. Comparing changes in dust proxy records between the Scotia Sea and Antarctic ice cores will also provide a detailed reconstruction of changes in the Southern Hemisphere westerlies on millennial and orbital timescales for the last 800 ky. Extending the ocean dust record beyond the last 800 ky will help to evaluate dust-climate couplings since the Pliocene, the potential role of dust in iron fertilization and atmospheric CO2 drawdown during glacials, and whether dust input to Antarctica played a role in the MPT. The principal scientific objective of Subantarctic Front Sites U1534 and U1535 at the northern limit of the Scotia Sea is to recon- struct and understand how ocean circulation and intermediate water formation responds to changes in climate with a special focus on the connectivity between the Atlantic and Pacific basins, the “cold water route.” The Subantarctic Front contourite drift, deposited between 400 and 2000 m water depth on the northern flank of an east–west trending trough off the Chilean continental shelf, is ideally situated to monitor millennial- to orbital-scale variability in the export of Antarctic Intermediate Water beneath the Subantarctic Front. During Expedition 382, we recovered continuously deposited sediments from this drift spanning the late Pleistocene (from ~0.78 Ma to recent) and from the late Pliocene (~3.1–2.6 Ma). These sites are expected to yield a wide array of paleoceanographic records that can be used to interpret past changes in the density structure of the Atlantic sector of the Southern Ocean, track migrations of the Sub- antarctic Front, and give insights into the role and evolution of the cold water route over significant climate episodes, including the following: • The most recent warm interglacials of the late Pleistocene and • The intensification of Northern Hemisphere glaciation.National Science Foundatio

Multilab Direct Replication of Flavell, Beach, and Chinsky (1966): Spontaneous Verbal Rehearsal in a Memory Task as a Function of Age

Work by Flavell, Beach, and Chinsky indicated a change in the spontaneous production of overt verbalization behaviors when comparing young children (age 5) with older children (age 10). Despite the critical role that this evidence of a change in verbalization behaviors plays in modern theories of cognitive development and working memory, there has been only one other published near replication of this work. In this Registered Replication Report, we relied on researchers from 17 labs who contributed their results to a larger and more comprehensive sample of children. We assessed memory performance and the presence or absence of verbalization behaviors of young children at different ages and determined that the original pattern of findings was largely upheld: Older children were more likely to verbalize, and their memory spans improved. We confirmed that 5- and 6-year-old children who verbalized recalled more than children who did not verbalize. However, unlike Flavell et al., substantial proportions of our 5- and 6-year-old samples overtly verbalized at least sometimes during the picture memory task. In addition, continuous increase in overt verbalization from 7 to 10 years old was not consistently evident in our samples. These robust findings should be weighed when considering theories of cognitive development, particularly theories concerning when verbal rehearsal emerges and relations between speech and memory

GM and KM immunoglobulin allotypes in the Galician population: new insights into the peopling of the Iberian Peninsula

<p>Abstract</p> <p>Background</p> <p>The current genetic structure of Iberian populations has presumably been affected by the complex orography of its territory, the different people and civilizations that settled there, its ancient and complex history, the diverse and persistent sociocultural patterns in its different regions, and also by the effects of the Iberian Peninsula representing a refugium area after the last glacial maximum. This paper presents the first data on <it>GM </it>and <it>KM </it>immunoglobulin allotypes in the Galician population and, thus, provides further insights into the extent of genetic diversity in populations settled in the geographic extremes of the Cantabrian region of northern Spain. Furthermore, the genetic relationships of Galicians with other European populations have been investigated.</p> <p>Results</p> <p>Galician population shows a genetic profile for <it>GM </it>haplotypes that is defined by the high presence of the European Mediterranean <it>GM</it>*<it>3 23 5* </it>haplotype, and the relatively high incidence of the African marker <it>GM*1,17 23' 5*</it>. Data based on comparisons between Galician and other Spanish populations (mainly from the north of the peninsula) reveal a poor correlation between geographic and genetic distances (<it>r </it>= 0.30, <it>P </it>= 0.105), a noticeable but variable genetic distances between Galician and Basque subpopulations, and a rather close genetic affinity between Galicia and Valencia, populations which are geographically separated by a long distance and have quite dissimilar cultures and histories. Interestingly, Galicia occupies a central position in the European genetic map, despite being geographically placed at one extreme of the European continent, while displaying a close genetic proximity to Portugal, a finding that is consistent with their shared histories over centuries.</p> <p>Conclusion</p> <p>These findings suggest that the population of Galicia is the result of a relatively balanced mixture of European populations or of the ancestral populations that gave rise to them. This would support the importance of the migratory movements that have taken place in Europe over the course of recent human history and their effects on the European genetic landscape.</p

Fluid challenges in intensive care: the FENICE study A global inception cohort study

Fluid challenges (FCs) are one of the most commonly used therapies in critically ill patients and represent the cornerstone of hemodynamic management in intensive care units. There are clear benefits and harms from fluid therapy. Limited data on the indication, type, amount and rate of an FC in critically ill patients exist in the literature. The primary aim was to evaluate how physicians conduct FCs in terms of type, volume, and rate of given fluid; the secondary aim was to evaluate variables used to trigger an FC and to compare the proportion of patients receiving further fluid administration based on the response to the FC.This was an observational study conducted in ICUs around the world. Each participating unit entered a maximum of 20 patients with one FC.2213 patients were enrolled and analyzed in the study. The median [interquartile range] amount of fluid given during an FC was 500 ml (500-1000). The median time was 24 min (40-60 min), and the median rate of FC was 1000 [500-1333] ml/h. The main indication for FC was hypotension in 1211 (59 %, CI 57-61 %). In 43 % (CI 41-45 %) of the cases no hemodynamic variable was used. Static markers of preload were used in 785 of 2213 cases (36 %, CI 34-37 %). Dynamic indices of preload responsiveness were used in 483 of 2213 cases (22 %, CI 20-24 %). No safety variable for the FC was used in 72 % (CI 70-74 %) of the cases. There was no statistically significant difference in the proportion of patients who received further fluids after the FC between those with a positive, with an uncertain or with a negatively judged response.The current practice and evaluation of FC in critically ill patients are highly variable. Prediction of fluid responsiveness is not used routinely, safety limits are rarely used, and information from previous failed FCs is not always taken into account