Evaluating Competition between Verbal and Implicit Systems with Functional Near-Infrared Spectroscopy

In category learning, explicit processes function through the prefrontal cortex (PFC) and implicit processes function through the basal ganglia. Research suggested that these two systems compete with each other. The goal of this study was to shed light on this theory. 15 undergraduate subjects took part in an event-related experiment that required them to categorize computer-generated line-stimuli, which varied in length and/or angle depending on condition. Subjects participated in an explicit rule-based (RB) condition and an implicit information-integration (II) condition while connected to a functional near-infrared spectroscopy (fNIRS) apparatus, which measured the hemodynamic response (HR) in their PFC. Each condition contained 2 blocks. We hypothesized that the competition between explicit and implicit systems (COVIS) would be demonstrated if, by block 2, task-accuracy was approximately equal across conditions with PFC activity being comparatively higher in the II condition. This would indicate that subjects could learn the categorization task in both conditions but were only able to decipher an explicit rule in the RB condition; their PFC would struggle to do so in the II condition, resulting in perpetually high activation. In accordance with predictions, results revealed no difference in accuracy across conditions with significant difference in channel activation. There were channel trends (p \u3c .1) which showed PFC activation decrease in the RB condition and increase in the II condition by block 2. While these results support our predictions, they are largely nonsignificant, which could be attributed to the event-related design. Future research should utilize a larger samples size for improved statistical power

The Cdc31p-binding protein Kar1p is a component of the half bridge of the yeast spindle pole body

KAR1 has been identified as an essential gene which is involved in karyogamy of mating yeast cells and in spindle pole body duplication of mitotic cells (Rose, M. D., and G. R. Fink. 1987. Cell. 48:1047-1060). We investigated the cell cycle-dependent localization of the Kar1 protein (Kar1p) and its interaction with other SPB components. Kar1p is associated with the spindle pole body during the entire cell cycle of yeast. Immunoelectron microscopic studies with anti-Kar1p antibodies or with the monoclonal antibody 12CA5 using an epitope-tagged, functional Kar1p revealed that Kar1p is associated with the half bridge or the bridge of the spindle pole body. Cdc31p, a Ca(2+)-binding protein, was previously identified as the first component of the half bridge of the spindle pole body (Spang, A., I. Courtney, U. Fackler, M. Matzner, and E. Schiebel. 1993. J. Cell Biol. 123:405-416). Using an in vitro assay we demonstrate that Cdc31p specifically interacts with a short sequence within the carboxyl terminal half of Kar1p. The potential Cdc31p-binding sequence of Kar1p contains three acidic amino acids which are not found in calmodulin-binding peptides, explaining the different substrate specificities of Cdc31p and calmodulin. Cdc31p was also able to bind to the carboxy terminus of Nuflp/Spc110p, another component of the SPB (Kilmartin, J. V., S. L. Dyos, D. Kershaw, and J. T. Finch. 1993. J. Cell Biol. 123:1175-1184). The association of Kar1p with the spindle pole body was independent of Cdc31p. Cdc31p, on the other hand, was not associated with SPBs of kar1 cells

A family case of fertile human 45,X,psu dic(15;Y) males

We report on a familial case including four male probands from three generations with a 45,X,psu dic(15;Y)(p11.2;q12) karyotype. 45,X is usually associated with a female phenotype and only rarely with maleness, due to translocation of small Y chromosomal fragments to autosomes. These male patients are commonly infertile because of missing azoospermia factor regions from the Y long arm. In our familial case we found a pseudodicentric translocation chromosome, that contains almost the entire chromosomes 15 and Y. The translocation took place in an unknown male ancestor of our probands and has no apparent effect on fertility and phenotype of the carrier. FISH analysis demonstrated the deletion of the pseudoautosomal region 2 (PAR2) from the Y chromosome and the loss of the nucleolus organizing region (NOR) from chromosome 15. The formation of the psu dic(15;Y) chromosome is a reciprocal event to the formation of the satellited Y chromosome (Yqs). Statistically, the formation of 45,X,psu dic(15;Y) (p11.2;q12) is as likely as the formation of Yqs. Nevertheless, it has not been described yet. This can be explained by the dicentricity of this translocation chromosome that usually leads to mitotic instability and meiotic imbalances. A second event, a stable inactivation of one of the two centromeres is obligatory to enable the transmission of the translocation chromosome and thus a stably reduced chromosome number from father to every son in this family

Scaling percentages and distributional patterns of benthic foraminifera with flux rates of organic carbon

Seafloor organic matter flux from marine primary productivity is quantified, and the range of annual flux rates is calculated and compared to the counts of benthic foraminifera at 382 surface sediment stations from the equatorial Guinea Basin to the Arctic Ocean. Benthic foraminifera show high variability in flux range dependent distributional patterns, with maximum deviations at lowest percentages. The occurrence of a single species covers flux ranges within one to three orders of magnitude. Only a small number of species shows a correlation of this broad range of organic fluxes versus percentages in a count. For C. wuellerstorfi a functional relationship for the recalculation of flux rates from percentages in a count can be given within a standard deviation below 2 g organic carbon [m 2 yr 1]. However, such functions have to be restricted to a specific size range counted. The patterns of dominance more closely scale the environmental optimum of the species in general. For interspecific combinations, these patterns identify the ranges of overlap, where it is impossible to distinguish between higher or lower fluxes on the basis of faunal composition. This is quantified for the co-occurrence of C. wuellerstorfi and U. peregrina near 20% for one species. On an ocean wide scale, a number of taxa can be used to define threshold values for the nutritive needs of the assemblages, most pronounced within annual flux ranges at 2-3 g org. C [m-2]. Different trophic needs of species can be attributed to their infaunal, epibenthic, or opportunistic behavior respectively, and examples for the flux dependent takeover in dominance are given. These quantifications may offer approximations for flux rate dependent faunal patterns in surface sediments and for the detection of flux rate dependent faunal fluctuations in the Quaternary record

A robust calibration of the clumped isotopes to temperature relationship for foraminifers

The clumped isotope (Δ47) proxy is a promising geochemical tool to reconstruct past ocean temperatures far back in time and in unknown settings, due to its unique thermodynamic basis that renders it independent from other environmental factors like seawater composition. Although previously hampered by large sample-size requirements, recent methodological advances have made the paleoceanographic application of Δ47 on small (<5 mg) foraminifer samples possible. Previous studies show a reasonable match between Δ47 calibrations based on synthetic carbonate and various species of planktonic foraminifers. However, studies performed before recent methodological advances were based on relatively few species and data treatment that is now outdated. To overcome these limitations and elucidate species-specific effects, we analyzed 14 species of planktonic foraminifers in sediment surface samples from 13 sites, covering a growth temperature range of ∼0–28 °C. We selected mixed layer-dwelling and deep-dwelling species from a wide range of ocean settings to evaluate the feasibility of temperature reconstructions for different water depths. Various techniques to estimate foraminifer calcification temperatures were tested in order to assess their effects on the calibration and to find the most suitable approach. Results from this study generally confirm previous findings that there are no species-specific effects on the Δ47-temperature relationship in planktonic foraminifers, with one possible exception. Various morphotypes of Globigerinoides ruber were found to often deviate from the general trend determined for planktonic foraminifers. Our data are in excellent agreement with a recent foraminifer calibration study that was performed with a different analytical setup, as well as with a calibration based exclusively on benthic foraminifers. A combined, methodologically homogenized dataset also reveals very good agreement with an inorganic calibration based on travertines. Our findings highlight the potential of the Δ47 paleothermometer to be applied to recent and extinct species alike to study surface ocean temperatures as well as thermocline variability for a multitude of settings and time scales

Disconnection between genetic and morphological diversity in the planktonic foraminifer Neogloboquadrina pachyderma from the Indian sector of the Southern Ocean

Eight SSU rDNA genetic types have been described in the planktonic foraminifera Neogloboquadrina pachyderma, but the level of correlation between genetic diversity and morphological variation remains unknown in this morphospecies. In this study, we combine molecular and morphometric analyses of specimens of N. pachyderma sampled during two consecutive years across a latitudinal gradient in the Indian sector of the Southern Ocean. We observe that three genetic types of N. pachyderma inhabit the (sub-)polar waters of the southern Indian Ocean where they have equivalent regional distributions to those previously observed in the South Atlantic. The geographic ranges of these genetic types are largely overlapping. Our morphometric data show that contrary to other planktonic foraminiferal morphospecies, there is no relationship between genetic diversity and morphological differentiation in at least two of the austral representatives of N. pachyderma (Type III and Type IV) despite a high morphological variability and large genetic distance between these types. These genetic types of N. pachyderma in the southern Indian Ocean thus constitute true cryptic species of planktonic foraminifera