A Modular Mind? A Test Using Individual Data from Seven Primate Species

It has long been debated whether the mind consists of specialized and independently evolving modules, or whether and to what extent a general factor accounts for the variance in performance across different cognitive domains. In this study, we used a hierarchical Bayesian model to re-analyse individual level data collected on seven primate species (chimpanzees, bonobos, orangutans, gorillas, spider monkeys, brown capuchin monkeys and long-tailed macaques) across 17 tasks within four domains (inhibition, memory, transposition and support). Our modelling approach evidenced the existence of both a domain-specific factor and a species factor, each accounting for the same amount (17%) of the observed variance. In contrast, inter-individual differences played a minimal role. These results support the hypothesis that the mind of primates is (at least partially) modular, with domain-specific cognitive skills undergoing different evolutionary pressures in different species in response to specific ecological and social demands.     

Demographic Trends of Aging — Application to Gerodontology1

Aging of the global world population both in developed and developing countries, an unbalanced male-female ratio within this elderly population, increasing populations – including elderly – within urban areas, all will have a marked effect on the practice of dentistry. Furthermore, major epidemiological changes occurring in the dental field, including an increasing dentition life expectancy, increasing root caries prevalence, decreasing coronal caries rates in children, and the relative increase in the prevalence of periodontal problems will have further impact on the dental care system. Major changes need to be anticipated both at the level of the care provider, including the dentist, the hygienist and the dental assistant, and at the level of the potential patient, especially among the geriatric population, if the profession is to be prepared to adequately address these issues.     

Recovery of15N-labelled fertilizer by Coastal bermudagrass in lignite minesoil

Minesoils developed from lignite surface mining in Texas are nutrient-poor and have a high N retention capacity. A major concern of landowners and soil conservationists is the response of Coastal bermudagrass to the application of low rates of ammonium-N fertilizer on these nutrient-poor minesoils. A glasshouse study, using¹⁵N-labelled ammonium sulfate fertilizer and lignite minesoil, was conducted to measure Coastal bermudagrass biomass production and fertilizer recovery during establishment in response to clipping at 2, 4, and 8 week intervals. At N rates of 0, 40, and 80 kg N ha^–1,increases in N fertilization increased Coastal bermudagrass aboveground biomass 5-fold, but showed only small increases in belowground biomass. Recovery of ammonium-N fertilizer ranged from 54 to 63%. Roots contained approximately the same N content across all fertilizer rates suggesting that young, estabilishing, Coatal bermudagrass roots reserve N until their N requirement is met. As more N is obtained above that which was needed to maintain roots, then additional N taken up by the plant was transported to aboveground plant parts for growth. Frequent clipping intensified N transport to aboveground tissues. Reduced amounts of N were contained in roots after clipping due to reductions in root growth, biomass, and resource demand. Fertilization of Coastal bermudagrass at low N rates with different N fertilizer forms influenced the distribution of N in the plant and affected N recovery by different parts of the plant.     

Abnormal intracellular sorting of O-linked carbohydrate-deficient interleukin-2 receptors.

The synthesis and intracellular sorting of the interleukin-2 (IL-2) receptor were studied with a line of mutant Chinese hamster ovary (CHO) cells with a reversible defect in protein O glycosylation. Under normal culture conditions the mutant ldlD cannot add N-acetylgalactosamine (Ga1NAc) to proteins. Ga1NAc is the first sugar of mucin-type O-linked oligosaccharides attached to protein. This O-glycosylation defect is rapidly corrected when Ga1NAc is added to the culture mediu. An expression vector for the p55 human IL-2 receptor was transfected into wild-type CHO and ldlD cells and the structure, stability, and cell surface expression of the receptor were examined by immunoprecipitation and antibody-binding assays. Essentially all of the mature form of the normally glycosylated IL-2 receptor in both wild-type CHO cells and ldlD cells incubated with Ga1NAc was expressed on the cell surface. The stability of O-linked carbohydrate-deficient (Od) IL-2 receptors (in ldlD cells without Ga1NAc) was normal; however, missorting of the Od receptors resulted in very little cell surface expression. The sialidase sensitivity and endoglycosidase H resistance of mature Od IL-2 receptors suggest that Od receptor missorting occurred in or beyond the trans Golgi apparatus. The abnormal sorting of the Od IL-2 receptor is compared with the O-glycosylation dependence of the surface expression and stability of the low-density lipoprotein receptor, decay-accelerating factor, and the major antigen envelope protein of Epstein-Barr virus.     

Colonization factors of diarrheagenicE. coli and their intestinal receptors

WhileEscherichia coli is common as a commensal organism in the distal ileum and colon, the presence of colonization factors (CF) on pathogenic strains ofE. coli facilitates attachment of the organism to intestinal receptor molecules in a species- and tissue-specific fashion. After the initial adherence, colonization occurs, and the involvement of additional virulence determinants leads to illness. EnterotoxigenicE. coli (ETEC) is the most extensively studied of the five categories ofE. coli that cause diarrheal disease, and has the greatest impact on health worldwide. ETEC can be isolated from domestic animals and humans. The biochemistry, genetics, epidemiology, antigenic characteristics, and cell and receptor binding properties of ETEC have been extensively described. Another major category, enteropathogenicE. coli (EPEC), has virulence mechanisms, primarily effacement and cytoskeletal rearrangement of intestinal brush borders, that are distinct from ETEC. An EPEC CF receptor has been purified and characterized as a sialidated transmembrane glycoprotein complex directly attached to actin, thereby associating CF-binding with host-cell response. Three, additional categories ofE. coli diarrheal disease, their colonization factors and their host cell receptors are discussed. It appears that biofilms exist in the intestine in a manner similar to oral bacterial biofilms, and thatE. coli is part of these biofilms as both commensals and pathogens.Abbreviations CF colonization factor - CFA Colonization Factor Antigen - CS coli-surface-associated antigen - EAggEC enteroaggregativeE. coli - ECDD E. coli diarrheal disease - EHEC enterohemorrhagicE. coli - EIEC enteroinvasiveE. coli - EPEC enteropathogenicE. coli - ETEC enterotoxigenicE. coli - Gal galactose - GalNAc N-acetyl galactosamine - LT heat-labile toxin - NeuAc N-acetyl neuraminic acid - PCF Putative colonization factor - RBC red blood cells - SLT Shiga-like toxin - ST heat-stable toxin     

The Ontogeny of Vocal Sequences: Insights from a Newborn Wild Chimpanzee (Pan troglodytes schweinfurthii)

International Journal of Primatology - Observations of early vocal behaviours in non-human primates (hereafter primates) are important for direct comparisons between human and primate vocal...     

Flow rate and vertical position influence ingestion rates of colonial zebra mussels (Dreissena polymorpha)

1. Zebra mussels aggregate to form dense colonies where, depending on the flow rate, individuals in different vertical locations within the colony may experience restricted food availability. 2. Using ³²P‐labelled Chlamydomonas angulosa, we found ingestion rates of individual mussels located at the surface to exceed those in the bottom of a 6 cm thick colony by up to 75%. 3. Higher velocities (10 and 20 cm s^?1) increased algal delivery to the colony's middle layer (2–4 cm depth), subsequently increasing ingestion rates to equal those in the surface layer, while increasing ingestion only for the smallest mussels in the bottom (4–6 cm). 4. At all vertical locations within the colonies, smaller mussels showed higher ingestion rates per unit mass than larger mussels, particularly at higher flow rates.     

Phosphorylation of rat muscle acetyl-CoA carboxylase by AMP-activated protein kinase and protein kinase A

Winder, W. W., H. A. Wilson, D. G. Hardie, B. B. Rasmussen,C. A. Hutber, G. B. Call, R. D. Clayton, L. M. Conley, S. Yoon, and B. Zhou. Phosphorylation of rat muscle acetyl-CoA carboxylase byAMP-activated protein kinase and protein kinase A. J. Appl. Physiol. 82(1): 219-225, 1997This studywas designed to compare functional effects of phosphorylation of muscleacetyl-CoA carboxylase (ACC) by adenosine 3,5-cyclicmonophosphate-dependent protein kinase (PKA) and by AMP-activatedprotein kinase (AMPK). Muscle ACC (272 kDa) was phosphorylated and thensubjected to sodium dodecyl sulfate-polyacrylamide gel electrophoresisfollowed by autoradiography. Functional effects of phosphorylation weredetermined by measuring ACC activity at different concentrations ofeach of the substrates and of citrate, an activator of the enzyme. Themaximal velocity(V_max) and theMichaelis constants(K_m) for ATP,acetyl-CoA, and bicarbonate were unaffected by phosphorylation by PKA.Phosphorylation by AMPK increased theK_m for ATP andacetyl-CoA. Sequential phosphorylation by PKA and AMPK, first withoutlabel and second with label, appeared to reduce the extent of label incorporation, regardless of the order. The activation constant (K_a) forcitrate activation was increased to the same extent by AMPKphosphorylation, regardless of previous or subsequent phosphorylation by PKA. Thus muscle ACC can be phosphorylated by PKA but with noapparent functional effects on the enzyme. AMPK appears to be the moreimportant regulator of muscle ACC.

     

The recombination activating genes,RAG 1 and RAG 2, are on chromosome 11p in humans and chromosome 2p in mice

The recombination activating genes RAG-1 and RAG-2 are adjacent genes that act synergistically to activate variable-diversity-joining (V(D)J) recombination. Southern analysis of hybrid cell lines derived from patients with the Wilms tumor-aniridia-genitourinary defects-mental retardation (WAGR) syndrome and from mutagenized cell hybrids selected for deletions in chromosome 11 has allowed us to map the chromosomal location of the human RAG locus. The RAG locus defines a new interval of human chromosome 11p, but is not associated with any genetically mapped human disease. Guided by the chromosomal localization of the human recombination activating genes, we have also mapped the location of the mouse Rag locus.     

Evidence for WT1 as a Wilms tumor (WT) gene: intragenic germinal deletion in bilateral WT.

The inactivation of two alleles at a locus on the short arm of chromosome 11 (band 11p13) has been suggested to be critical steps in the development of Wilms tumor (WT), a childhood kidney tumor. Two similar candidate WT cDNA clones (WT33 and LK15) have recently been identified on the basis of both their expression in fetal kidney and their location within the smallest region of overlap of somatic 11p13 deletions in some tumors. These homozygous deletions, however, are large and potentially affect more than one gene. Using a cDNA probe to the candidate gene, we have analyzed DNA from both normal and tumor tissue from WT patients, in an effort to detect rearrangements at this locus. We report here a patient with bilateral WT who is heterozygous for a small (less than 11 kb) germinal deletion within this candidate gene. DNA from both tumors is homozygous for this intragenic deletion allele, which, by RNA-PRC sequence analysis, is predicted to encode a protein truncated by 180 amino acids. These data support the identification of this locus as an 11p13 WT gene (WT1) and provide direct molecular data supporting the two-hit mutational model for WT.