Chronometers and Units in Early Archaeology and Paleontology

Early in the nineteenth century, geologist Charles Lyell reasoned that successively older faunas would contain progressively more extinct species and younger faunas relatively more extant species. The present, with one-hundred percent extant species, was the chronological anchor. In archaeology a similar notion underpins the direct historical approach: Successively older cultures will contain progressively fewer of the cultural traits found in extant cultures and relatively more prehistoric traits. As in Lyell\u27s scheme, the chronological anchor is the present. When A. L. Kroeber invented frequency seriation in the second decade of the twentieth century, he retained the present as a chronological anchor but reasoned that the oldest cultural manifestation would contain the highest percentage of a variant, or what came to be known as a style, of an ancient trait, and successively younger cultural manifestations would have progressively lower percentages of that variant. The principle of overlapping permitted building sequences of fossils and artifacts, but differences in the units that allowed the chronometers to be operationalized reveal significant epistemological variation in how historical research is undertaken. This variation should be of considerable interest to paleobiologists and archaeologists alike, especially given recent archaeological interest in creating and explaining historical lineages of artifacts

Host Genomic Influences on HIV/AIDS

The AIDS era has seen multiple advances in the power of genetics research; scores of host genetic protective factors have been nominated and several have translated to the bedside. We discuss how genomics may inform HIV/AIDS prevention, treatment and eradication

Seriation, Superposition, and Interdigitation: a History of Americanist Graphic Depictions of Culture Change

Histories of Americanist archaeology regularly confuse frequency seriation with a technique for measuring the passage of time based on superposition - percentage stratigraphy - and fail to mention interdigitation as an important component of some percentage-stratigraphic studies. Frequency seriation involves the arrangement of collections so that each artifact type displays a unimodal frequency distribution, but the direction of time\u27s flow must be determined from independent evidence. Percentage stratigraphy plots the fluctuating frequencies of types, but the order of collections is based on their superposition, which in turn illustrates the direction of time\u27s flow. Interdigitation involves the integration of sets of percentage-stratigraphy data from different horizontal proveniences under the rules that (1) the order of superposed collections cannot be reversed and (2) each type must display a unimodal frequency distribution. Ceramic stratigraphy is similar to occurrence seriation, as both focus on the presence-absence of types with limited temporal distributions - index fossils - but the former uses the superposed positions of types to indicate the direction of time\u27s flow, whereas occurrence seriation does not

Use of Irradiated and Formalin-fixed Trichomonas vaginalis to Examine Protective Immune Responses in the Mouse Intraperitoneal Model

Gamma irradiated Trichomonas vaginalis was used to initiate a protective immune response in mice by intraperitoneal inoculation using host mortality as the measure of virulence. Irradiated trichomonads of a virulent strain gave some immune protection but no more so than the use of formalin-fixed, virulent trichomonads. A formalin-fixed virulent strain combined with complete Freund\u27s adjuvant (CFA) gave complete protection. Metabolically produced antigens do not appear to be important in conferring protective immunity in these experiments. A common laboratory strain of T. vaginalis (ATCC 30001) was used as an avirulent control. It gave no protection against a virulent strain. Combining CFA with ATCC 30001 (avirulent) gave partial protection indicating that a protective antigen is present, but needed an immune stimulant to be detected. IgG analysis corresponded to the mortality results with the avirulent strain being the weakest responder and the strongest being the formalin-fixed virulent strain with CFA. Western blot analysis indicated a band of about 31-kDa that was present using the protocols that showed from partial to complete protection. This band was not present using the avirulent strain but appeared with the addition of CFA. These results indicated that a 31-kDa protein is present in the avirulent strain but it requires an immune stimulant to be revealed. Whether this antigen confers protective immunity or not in the mouse intraperitoneal model is an open question

What Is Evolution? A Response to Bamforth

Douglas Bamforth\u27s recent paper in American Antiquity, Evidence and Metaphor in Evolutionary Archaeology, charges that Darwinism has little to offer archaeology except in a metaphorical sense. Specifically, Bamforth claims that arguments that allegedly link evolutionary processes to the archaeological record are unsustainable. Given Bamforth\u27s narrow view of evolution: that it must be defined strictly in terms of changes in gene frequency: he is correct. But no biologist or paleontologist would agree with Bamforth\u27s claim that evolution is a process that must be viewed fundamentally at the microlevel. Evolutionary archaeology has argued that materials in the archaeological record are phenotypic in the same way that hard parts of organisms are. Thus changes in the frequencies of archaeological variants can be used to monitor the effects of selection and drift on the makers and users of those materials. Bamforth views this extension of the human phenotype as metaphorical because to him artifacts are not somatic features, meaning their production and use are not entirely controlled by genetic transmission. He misses the critical point that in terms of evolution, culture is as significant a transmission system as genes are. There is nothing metaphorical about viewing cultural transmission from a Darwinian point of view

Application of Adaptive Learning Networks for the Characterization of Two-Dimensional and Three-Dimensional Defects in Solids

The objective of the work was to develop an ultrasonic inversion procedure which (1) discriminates, (2) sizes, and (3) determines the orientation of two-dimensional (crack-like) and· three-dimensional (void-like) defects in materials. Adaptive learning networks (ALN\u27s) were used to estimate directly the defect size and orientation parameters from the spectrum of the echo transient. A 19-element hexagonal synthetic array measured the scattered field within a 60-degree solid angle aperture. The ALN\u27 s were trained on theoretically generated spectral data where the crack forward scattering model was based on the Geometrical Diffraction Theory and the void model was based on the exact Scattering Matrix Theory. The theoretically trained models were evaluated on both theoretical and experimental data. Excellent results were obtained, and the errors for size and odentation estimates were, in general, less than 10%. The significance of this work is that: (1) the ALN approach to defect characteristics provides a systematic procedure for discovering relationships in the data which could otherwise be overlooked, and (2) significant economic benefits can be gained by simulating difficult-to-produce defect reflector scenarios. Furthermore, a result of this work has been the development of an algorithm which can ultimately be applied in field and industrial use

Publishing Archaeology in Science and Scientific American, 1940-2003

Many new, or processual, archaeologists of the 1960s argued that Americanist archaeology became scientific only in the 1960s. The hypothesis that the rate of publication of archaeological research in Science and Scientific American increased after about 1965, as new archaeologists sought to demonstrate to their peers and other scientists that archaeology was indeed a science, is disconfirmed. The rate of archaeological publication in these journals increased after 1955 because the effort to be more scientific attributed to the processualists began earlier. Higher publication rates in both journals appear to have been influenced by an increased amount of archaeological research, a higher rate of archaeological publication generally, and increased funding. The hypothesis that editorial choice has strongly influenced what has been published in Science is confirmed; articles focusing on multidisciplinary topics rather than on narrow archaeological ones dominate the list of titles over the period from 1940 through 2003

The Acute Effects of Cardiorespiratory Exercise on Telomere-Associated Genes and MicroRNA Expression in Immune Cell Subsets.

The acute effects of cardiorespiratory exercise on telomere-associated genes and microRNA expression in immune cell subsets. CHILTON WL, MARQUES FZ, O’BRIEN BJ, and CHARCHAR F. School of Health Sciences; University of Ballarat; Victoria, Australia. ABSTRACT Telomeres are specialized nucleoprotein structures that protect the ends of linear chromosomes from degradation. Habitual physical activity is positively associated with longer leukocyte telomere length; however the molecular mechanisms underpinning the association are unclear. Human telomerase reverse transcriptase (hTERT) is the rate-limiting component of the telomere extending enzyme telomerase. The effective functioning of the adaptive immune system depends heavily upon the replicative potential of T cells, which is largely determined by telomere length and hTERT expression. Sirtuin 6 (SIRT6) also serves important pro-telomeric functions via an interaction with telomeric chromatin and regulatory roles in genome stabilization and DNA repair. It is unknown if cardiorespiratory exercise acutely regulates mRNA levels of hTERT, SIRT6 or other telomere-associated genes in white blood cells in general and T cell subsets in particular. Additionally, the exercise-induced regulation of microRNAs (short, non-coding RNA molecules that negatively regulate gene expression) with potential telomeric functions is unknown. Twenty-three healthy males (mean age=23.96 ±1.49 years) undertook 30min of treadmill running at 80% of previously determined VO2peak. Blood samples were taken before exercise, immediately post-exercise and 60min post-exercise. White blood cells and flow cytometry-sorted T cell subsets were assessed via quantitative polymerase chain reaction for differential regulation of telomeric genes and microRNAs. Expression levels of hTERT and SIRT6 mRNA were up-regulated following exercise in white blood cells and various T cell subsets (CD4+ naïve, CD4+ memory, CD8+ naïve, and CD8+ memory). Additionally, exercise differentially regulated several genes associated with telomere structure. A total of 56 microRNAs were differentially regulated post-exercise, six of which were investigated for potential telomeric functions. MicroRNAs-186, 636, 15a, and 96 showed significant up-regulation 60min post-exercise. MicroRNAs-186 and 636 showed detectable differential regulation in naïve and memory subsets. Intense cardiorespiratory exercise differentially regulated a host of telomeric genes in white blood cells and T cell subsets. Furthermore, it resulted in differential regulation of 56 microRNAs, some of which have binding potential to telomeric genes. Importantly, we demonstrated cell type-specific expression patterns in telomeric genes and microRNA. These results could have important implications for T cell-dependent immune functions and telomere homeostasis