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Grylloblatta campodeiformis campodeiformis Walker (Grylloblattodea: Grylloblattidae) was commonly collected during summer from trees killed by the mountain pine beetle, Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), in subalpine forests of Alberta, Canada. Gut content analysis revealed that the grylloblattids fed on subcortical invertebrates. This newly reported habitat association shows that this species is not limited to strictly alpine habitats and glacial margins, and thus may be more widespread and common than suggested by earlier reports.
Human organoid models recapitulate many aspects of the complex composition and function of native organs. One of the main challenges in developing these models is the growth and maintenance of three-dimensional tissue structures and proper cellular organization that enable function. Biomaterials play an important role by providing a defined and tunable three-dimensional environment that is required for complex cellular organization and organoid growth in vitro or in vivo. This review summarizes organoids of the respiratory and digestive system, and the use of biomaterials to improve upon these model systems.
We tested the applicability of the “passive sampling” hypothesis and theory of island biogeography (TIB) for explaining the diversity of forest-dwelling carabid assemblages (Carabidae: Coleoptera) on 30 forested islands (0.2–980.7 ha) in Lac la Ronge and the adjacent mainland in Saskatchewan, Canada. Species richness per unit area increased with distance to mainland with diversity being highest on the most isolated islands. We detected neither a positive species-area relationship, nor significant differences in species richness among island size classes, or between islands and the mainland. Nonetheless, carabid assemblages distinctly differed on islands <1 ha in area and gradually approached the structure of mainland assemblages as island area increased. Small islands were characterised by abundant populations of small-bodied, winged species and few if any large-bodied, flightless species like Carabus taedatus Fabricius. Our findings suggest that neither the “passive sampling” hypothesis nor the theory of island biogeography adequately explain carabid beetle diversity patterns observed among islands in Lac la Ronge. Instead, we hypothesise that population processes such as higher extinction rates of large-bodied, flightless species and the associated release of smaller-bodied, flying species from intra-guild predation on small islands contribute to observed differences in the structure of carabid assemblages between islands.
Whitebark pine, Pinus albicaulis Engelmann (Pinaceae), a foundational species of North American subalpine ecosystems, is endangered across its range and continued decline is inevitable. Little is known about the invertebrate fauna associated with this species which, if specific to whitebark pine, may also be threatened or endangered. We compared the composition of saproxylic beetle assemblages associated with whitebark pine and co-occurring lodgepole pine, Pinus contorta latifolia (Engelmann) Critchfield (Pinaceae), recently killed by mountain pine beetle (MPB), Dendroctonus ponderosae Hopkins (Coleoptera: Curculionidae), in subalpine forests in Alberta, Canada. Redundancy and rarefaction analyses revealed that beetle assemblage composition was influenced by snag class (i.e., time since death) but differed little among the two pine species within snag classes. However, a subset of the assemblage known to be associated with the MPB differed significantly in composition between the two pines. No common species were exclusively associated with whitebark pines; however, seven species were rarely collected only on whitebark pine. With the possible exception of these rare species, felling and burning infested whitebark pines to control the MPB will not likely endanger saproxylic beetles associated with this tree.
Background. A better understanding of the neural basis of social cognition including mindreading (or theory of mind) and empathy might help to explain some deficits in social functioning in people with schizophrenia. Our aim was to review neuroimaging and neuropsychological studies on social cognition, as they may shed light on the neural mechanisms of social cognition and its dysfunction in patients with schizophrenia.
Method. A selective literature review was undertaken.
Results. Neuroimaging and neuropsychological studies suggest convergence upon specific networks for mindreading and empathy (the temporal cortex, amygdala and the prefrontal cortex). The frontal lobe is likely to play a central role in enabling social cognition, but mindreading and empathic abilities may require relatively different weighting of subcomponents within the same frontal-temporal social cognition network.
Conclusions. Disturbances in social cognition may represent an abnormal interaction between frontal lobe and its functionally connected cortical and subcortical areas. Future studies should seek to explore the heterogeneity of social dysfunction within schizophrenia.
The large series of sacrificial victims excavated from the Feathered
Serpent Pyramid (ca. a.d. 200) includes 72 males identified as
soldiers. Although most of these wore pendants of imitation human
maxillae, four soldiers each had between seven and eleven real human
maxillae. Dental dimensions indicate that most, and perhaps all, of
these trophies were from males. Dental attrition levels suggest a
broader and flatter age profile for the pendants than for the soldiers,
with a significantly higher mean age. The oxygen-isotope ratios in the
dental phosphate of the pendant teeth, which indicate the geographic
origins of those individuals, point to their derivation from three
different regions, one of them probably in or near the Basin of Mexico
itself. Apparently the soldiers had fought in more than one campaign,
and the early interactions of Teotihuacan with more distant societies
had sometimes involved an element of violence.
This study addresses the political and military structure of early Teotihuacan through the analysis of oxygen-isotope ratios in skeletal phosphate from 41 victims of a sacrifice associated with the Feathered Serpent Pyramid. Oxygen-isotope ratios are markers of geographic identity. A comparison of bone and enamel values, which provides a contrast between environments experienced during growth and those of adulthood, illustrates that at least four different regions are represented in this sample. Those identified as soldiers had either lived locally since childhood or had moved to Teotihuacan from several foreign locations. Most had lived in Teotihuacan for a prolonged period before their death. This pattern suggests foreign “recruitment” or mercenary behavior. The women had either lived all their lives in Teotihuacan or had moved from there to a foreign location. Most of the individuals in the center of the pyramid (burial 14) did not come from Teotihuacan, nor had they lived in the city long before their deaths. We suggest that the choice of victims was meant to demonstrate Teotihuacan's powerful ideology to the rest of the Mesoamerican world. Notably, this isotopic evidence of physical interaction between Teotihuacan and foreign regions considerably predates the currently existing archaeological evidence.
The ABA-1 protein of Ascaris lumbricoides (of humans) and Ascaris suum (of pigs) is abundant in the pseudocoelomic fluid
of the parasites and also appears to be released by the tissue-parasitic larvae and the adult stages. The genes encoding the
polyprotein precursor of ABA-1 (aba-1) were found to be arranged similarly in the two taxa, comprising tandemly
repeating units encoding a large polyprotein which is cleaved to yield polypeptides of approximately 15 kDa which fall
into 2 distinct classes, types A and B. The polyprotein possibly comprises only 10 units. The aba-1 gene of A. lumbricoides
is polymorphic, and the majority of substitutions observed occur in or near predicted loop regions in the encoded proteins.
mRNA for ABA-1 is present in infective larvae within the egg, and in all parasitic stages, but was not detectable in
unembryonated eggs. ABA-1 mRNA was confined to the gut of adult parasites, and not in body wall or reproductive
tissues. Recombinant protein representing a single A-type unit for the A. lumbricoides aba-1 gene was produced and found
to bind retinol (Vitamin A) and a range of fatty acids, including the pharmacologically active lipids lysophosphatidic acid,
lysoplatelet activating factor, and there was also evidence of binding to leukotrienes. It failed to bind to any of the
anthelmintics screened. Differential Scanning Calorimetry showed that the recombinant protein was highly stable, and
unfolded in a single transition at 90·4 °C. Analysis of the transition indicated that the protein occurs as a dimer and that
the dimer dissociates simultaneously with the unfolding of the monomer units.
PET studies of verbal fluency in schizophrenia report a failure of ‘deactivation’ of left superior temporal gyrus (STG) in the presence of activation of left dorsolateral prefrontal cortex (DLPFC), which deficit has been attributed to underlying ‘functional disconnectivity’.
To test whether these findings provide trait-markers for schizophrenia.
We used H215O PET to examine verbal fluency in 10 obligate carriers of the predisposition to schizophrenia, 10 stable patients and 10 normal controls.
We found no evidence of a failure of left STG deactivation in carriers or patients. Instead, patients failed to deactivate the precuneus relative to other groups. We found no differences in functional connectivity between left DLPFC and left STG but patients exhibited significant disconnectivity between left DLPFC and anterior cingulate cortex.
Failure of left STG ‘deactivation’ and left fronto-temporal disconnectivity are not consistent findings in schizophrenia; neither are they trait-markers for genetic risk. Prefrontal functional disconnectivity here may characterise the schizophrenic phenotype.
Cement-based waste forms are one of the most widely used waste disposal options, yet definitive knowledge of the fate of the waste species inside the waste form is lacking. A fundamental understanding of the chemistry and microstructure of the waste forms would lead to a better understanding of the mass transfer of the waste species, more confidence in predicting and extrapolating waste-form performance, and improved design of waste forms. Better and cheaper leach tests would lead to quicker and more cost-effective screening of waste-form alternatives, cement-based and otherwise. In addition, assessment of durability may be important to predicting waste-form performance in the field over periods of decades and centuries.
Assemblages of carabid beetles occurring in anthropogenic habitats in western Canada include native and introduced species. In this study, about 70% of the native species encountered in anthropogenic habitats have their main centres of abundance in native grassland. Twenty species known from British Columbia are of recent European origin. These species were probably introduced in ballast carried by commercial sailing vessels or in shipments of nursery stock. The species that have successfully colonized western Canada cannot be distinguished from a random sample of the estimated source fauna with respect to either taxonomic distribution or body size. However, all introduced species are characteristic of disturbed and/or anthropogenic habitats in Great Britain and are strictly synanthropic in British Columbia. Where they occurred, introduced species were usually numerically dominant members of anthropogenic assemblages. Both flight and human-assisted transport must be invoked to explain the patterns of range expansion observed for introduced species. Although the presence of introduced species was correlated with reduced diversity of native species, the carabid fauna of western Canada has been generally enriched because only one native species is strictly synanthropic.