Problems in determination of skeletal lead burden in archaeological samples: an example from the First African Baptist Church population

Human bone lead content has been demonstrated to be related to socioeconomic status, occupation and other social and environmental correlates. Skeletal tissue samples from 135 individuals from an early nineteenth century Philadelphia cemetery (First African Baptist Church) were studied by electrothermal atomic absorption spectrometry and X-ray fluorescence for lead content. High bone lead levels led to investigation of possible diagenetic effects. These were investigated by several different approaches including distribution of lead within bone by X-ray fluorescence, histological preservation, soil lead concentration and acidity as well as location and depth of burial. Bone lead levels were very high in children, exceeding those of the adult population that were buried in the cemetery, and also those of present day adults. The antemortem age-related increase in bone lead, reported in other studies, was not evidenced in this population. Lead was evenly deposited in areas of taphonomic bone destruction. Synchrotron X-ray fluorescence studies revealed no consistent pattern of lead microdistribution within the bone. Our conclusions are that postmortem diagenesis of lead ion has penetrated these archaeological bones to a degree that makes their original bone lead content irretrievable by any known method. Increased bone porosity is most likely responsible for the very high levels of lead found in bones of newborns and children.     

Virtual Bystanders in a Language Lesson: Examining the Effect of Social Evaluation,Vicarious Experience,Cognitive Consistency and Praising on Students' Beliefs,Self-Efficacy and Anxiety in a Virtual Reality Environment

Bystanders in a real world''s social setting have the ability to influence people’s beliefs and behavior. This study examines whether this effect can be recreated in a virtual environment, by exposing people to virtual bystanders in a classroom setting. Participants (n = 26) first witnessed virtual students answering questions from an English teacher, after which they were also asked to answer questions from the teacher as part of a simulated training for spoken English. During the experiment the attitudes of the other virtual students in the classroom was manipulated; they could whisper either positive or negative remarks to each other when a virtual student was talking or when a participant was talking. The results show that the expressed attitude of virtual bystanders towards the participants affected their self-efficacy, and their avoidance behavior. Furthermore, the experience of witnessing bystanders commenting negatively on the performance of other students raised the participants’ heart rate when it was their turn to speak. Two-way interaction effects were also found on self-reported anxiety and self-efficacy. After witnessing bystanders’ positive attitude towards peer students, participants’ self-efficacy when answering questions received a boost when bystanders were also positive towards them, and a blow when bystanders reversed their attitude by being negative towards them. Still, inconsistency, instead of consistency, between the bystanders’ attitudes towards virtual peers and the participants was not found to result in a larger change in the participants’ beliefs. Finally the results also reveal that virtual flattering or destructive criticizing affected the participants’ beliefs not only about the virtual bystanders, but also about the neutral teacher. Together these findings show that virtual bystanders in a classroom can affect people’s beliefs, anxiety and behavior.     

The adenylate kinase genes of M. voltae,M. thermolithotrophicus,M. jannaschii,and M. igneus define a new family of adenylate kinases

The adenylate kinase genes (adkA) were cloned from four closely related methanogenic members of the Archaea: the mesophile Methanococcus voltae (Mv), the thermophile M. thermolithotrophicus (Mt) and the hyperthermophiles M. jannaschii (Mj) and M. igneus (Mi). All four genes encode a protein of 192 amino acids (aa), and the four enzymes were closely related, with 68–81% aa identity in pairwise comparisons. It is anticipated that the enzyme set will provide the basis for studies that can establish the structural basis for ADK thermal stability. Mj and Mi contained a gene homologous to M. vannielii secY upstream of adkA, while Mv and Mt contained an unidentified, yet conserved, upstream open reading frame (ORF). Mt, Mj and Mi, but not Mv, contained an unidentified, yet highly conserved, ORF directly downstream of adkA. Based on their size, predicted secondary structure and phylogenetic relation to bacterial and eukaryotic adenylate kinases (ADK), it was concluded that the archaeal adkA genes encoded a unique class of ADK, and suggested that Euryarchaeotal and Crenarchaeotal branches of the Archaea contain separate subclasses of the enzyme.     

Development of microsatellite markers in Myotis sodalis and cross-species amplification in M. gricescens, M. leibii, M. lucifugus, and M. septentrionalis

The Indiana bat (Myotis sodalis) is a highly endangered vespertilionid bat whose distribution is associated with limestone caves in the eastern United States. We present nine new polymorphic nuclear microsatellite markers for Myotis sodalis developed using an enriched library method. A total of 62 M. sodalis from two populations were used to estimate genetic diversity parameters. In M. sodalis, the number of alleles observed for each locus ranged from 17 to 48 alleles and expected heterozygosity ranged from 0.894 to 0.973. The 9 microsatellite markers were also tested on M. gricescens, M. leibii, M. lucifugus, and M. septentrionalis. These polymorphic microsatellite markers provide a valuable tool for investigating the population genetics of these species and will provide important genetic data useful for the conservation and recovery of the endangered Indiana bat.     

Inbreeding in Saguenay-Lac-St-Jean (Quebec, Canada): a study of Catholic Church dispensations 1842-1971.

Saguenay-Lac-St-Jean (SLSJ) is a rather geographically isolated region of Quebec which shows a high occurrence of hereditary disorders. It has been suggested that high inbreeding might explain this situation. We studied the inbreeding in the SLSJ region by 10-year periods from 1842 till 1971 using the Catholic Church dispensations. The values of the mean inbreeding coefficient were found to be low during the whole period, reaching a peak of 22.94 x 10(-4) during the period 1902-1911. The values observed in the SLSJ were lower than those found in most regions of Quebec and similar to those reported in European populations.     

Metarhizium frigidum sp. nov.: a cryptic species of M. anisopliae and a member of the M. flavoviride complex

The anamorph genus Metarhizium is composed of arthropod pathogens, several with broad geographic and host ranges. Members of the genus, including "M. anisopliae var. frigidum" nomen nudum and Metarhizium flavoviride, have been used as biological insecticides. In a recent revision of the genus the variety "M. anisopliae var. frigidum" was suggested to be a synonym of M. flavoviride based largely on ITS sequence phylogenetic analysis. In this study we conducted morphological evaluations and multigene phylogenetic analyses with EF-1alpha, RPB1 and RPB2 for strains of M. flavoviride and "M. anisopliae var. frigidum." Included in these evaluations were the ex-type of M. flavoviride var. flavoviride and what likely would be considered the "ex-type' of the invalidly published taxon "M. anisopliae var. frigidum". Based on morphological and molecular evidence we conclude that "M. anisopliae var. frigidum" is distinct from M. flavoviride and the taxon M. frigidum sp. nov. is described.     

In celebration of Sydney M. Finegold, M.D.: bacteroides fragilis in the colon: the good & the bad

Dr. Sydney Finegold is one of the most heralded leaders in the discovery, classification and scientific knowledge of anaerobic bacteria. On this occasion of his 90th birthday, this paper celebrates his lifetime of accomplishments and provides a perspective on the changes and growth in our understanding of one anaerobic species, Bacteroides fragilis. Over the last nearly 40 years, clinical and research data have fostered our current view that B. fragilis are essential symbiotes as well as, in some circumstances, pathogens with the capacity to induce both acute systemic and abdominal illnesses and possibly chronic colonic diseases.