Scaling of Hunter Gatherer Camp Size and Human Sociality

One of the most commonly-observed properties of human settlements, both past and present, is the tendency for larger settlements to display higher population densities. Work in urban science and archaeology suggests this densification pattern reflects an emergent spatial equilibrium where individuals balance movement costs with social interaction benefits, leading to increases in aggregate productivity and social interdependence. In this context, it is perhaps not surprising that the more temporary camps created by mobile hunters and gatherers exhibit a tendency to become less dense with their population size. Here we examine why this difference occurs and consider conditions under which hunter-gatherer groups may transition to sedentism and densification. We investigate the relationship between population and area in mobile hunter-gatherer camps using a dataset, representing a large cross-cultural sample, derived from the ethnographic literature. We present a model based on the interplay between social interactions and scalar stress for the relationship between camp area and group size that describes the observed patterns among mobile hunter-gatherers. The model highlights the tradeoffs between the costs and benefits of proximity and interaction that are common to all human aggregations and specifies the constraints that must be overcome for economies of scale and cooperation to emerge

Stripper System Performance in the Replacement Tritium Facility

The Replacement Tritium Facility (RTF) at the Savannah River Site in the United States was designed and built to handle kilogram levels of tritium. The RTF was started up in January 1994. All the design objectives were achieved. To minimize tritium release to the environment, the tritium handling process is installed inside nitrogen-atmosphere gloveboxes. Any tritium that might leak from the process to the gloveboxes is recovered by stripper systems. The tritium concentration in the gloveboxes is normally maintained at below 0.1 Ci/m{sup 3}. During a large tritium leak from the process to the glovebox, the stripper system lowered the tritium concentration in the glovebox from about 8,000 Ci/m{sup 3} to about 100 Ci/m{sup 3} in one hour. After that the tritium concentration decreased very slowly. It required 5 days of stripping before the concentration was down to about 10 Ci/m{sup 3}

Urbanism and the division of labour in the Roman Empire

One of the hallmarks of human agglomeration is an increase in the division of labour, but the exact nature of this relationship has been debated among anthropologists, sociologists, economists, and historians and archaeologists. Over the last decade, researchers investigating contemporary urban systems have suggested a novel explanation for the links between the numbers of inhabitants in settlements and many of their most important characteristics, which is grounded in a view of settlements as social networks embedded in built environments. One of the remarkable aspects of this approach is that it is not based on the specific conditions of the modern world (such as capitalism or industrialization), which raises the issue of whether the relationships observed in contemporary urban systems can also be detected in pre-modern urban or even non-urban systems. Here, we present a general model for the relationship between the population and functional diversity of settlements, where the latter is viewed as an indicator of the division of labour. We then explore the applicability of this model to pre-modern contexts, focusing on cities in the Roman Empire, using estimates of their numbers of inhabitants, numbers of documented professional associations, and numbers of recorded inscriptions to develop an index of functional diversity. Our results are consistent with theoretical expectations, adding further support to the view that urban systems in both contemporary and pre-modern contexts reflect a common set of generative processes

Tritium stripping by a catalytic exchange stripper

A catalytic exchange process for stripping elemental tritium from gas streams has been demonstrated. The process uses a catalyzed isotopic exchange reaction between tritium in the gas phase and protium or deuterium in the solid phase on alumina. The reaction is catalyzed by platinum deposited on the alumina. The process has been tested with both tritium and deuterium. Decontamination factors (ration of inlet and outlet tritium concentrations) as high as 1000 have been achieved, depending on inlet concentration. The test results and some demonstrated applications are presented

Settlement scaling and increasing returns in an ancient society

A key property of modern cities is increasing returns to scale—the finding that many socioeconomic outputs increase more rapidly than their population size. Recent theoretical work proposes that this phenomenon is the result of general network effects typical of human social networks embedded in space and, thus, is not necessarily limited to modern settlements. We examine the extent to which increasing returns are apparent in archaeological settlement data from the pre-Hispanic Basin of Mexico. We review previous work on the quantitative relationship between population size and average settled area in this society and then present a general analysis of their patterns of monument construction and house sizes. Estimated scaling parameter values and residual statistics support the hypothesis that increasing returns to scale characterized various forms of socioeconomic production available in the archaeological record and are found to be consistent with key expectations from settlement scaling theory. As a consequence, these results provide evidence that the essential processes that lead to increasing returns in contemporary cities may have characterized human settlements throughout history, and demonstrate that increasing returns do not require modern forms of political or economic organization

The Global Dynamics of Inequality (GINI) project: analysing archaeological housing data

The GINI project investigates the dynamics of inequality among populations over the long term by synthesising global archaeological housing data. This project brings archaeologists together from around the world to assess hypotheses concerning the causes and consequences of inequality that are of relevance to contemporary societies globally

Clinical presentation, auscultation recordings, ultrasonographic findings and treatment response of 12 adult cattle with chronic suppurative pneumonia: case study

Auscultation is considered the critical component of the veterinary clinical examination for the diagnosis of bovine respiratory disease but the accuracy with which adventitious sounds reflect underlying lung pathology remains largely unproven. Modern portable ultrasound machines provide the veterinary practitioner with an inexpensive, non-invasive tool with which to examine the pleural surfaces and superficial lung parenchyma. Simultaneous recording of sounds overlying normal lung and defined pathology allows critical assessment of auscultated sounds in the same animal removing confounding factors such as respiratory rate and thickness of the chest wall (body condition). Twelve cows, referred to the University of Edinburgh Veterinary School, were diagnosed with chronic suppurative pneumonia and enrolled into this prospective study to record and monitor lung sounds, ultrasonographic findings, and response to a standardised antibiotic treatment regimen. Most cows (8/12) had a normal rectal temperature on presentation but all cows had received antibiotic therapy at some time in the previous two weeks and six animals were receiving antibiotic treatment upon admission. All cattle were tachypnoeic (>40 breaths per minute) with frequent and productive coughing, halitosis, and a purulent nasal discharge most noticeable when the head was lowered. Ultrasonographic examination of the chest readily identified pathological changes consistent with severe lung pathology subsequently confirmed as chronic suppurative pneumonia in four cows at necropsy; eight cows recovered well after antibiotic treatment and were discharged two to six weeks after admission. It proved difficult to differentiate increased audibility of normal lung sounds due to tachypnoea from wheezes; coarse crackles were not commonly heard. In general, sounds were reduced in volume over consolidated lung relative to normal lung tissue situated dorsally. Rumen contraction sounds were commonly transmitted over areas of lung pathology. Trueperella (formerly Arcanobacterium) pyogenes was isolated from three of four lung tissue samples at necrospy. Treatment with procaine penicillin for 42 consecutive days resulted in marked improvement with return to normal appetite and improvement in body condition in 8 of 12 cows (67%) where lesions did not extend more than 10-15 cm above the level of the olecranon on both sides of the chest

The Global Dynamics of Inequality (GINI) project: analysing archaeological housing data

The GINI project investigates the dynamics of inequality among populations over the long term by synthesising global archaeological housing data. This project brings archaeologists together from around the world to assess hypotheses concerning the causes and consequences of inequality that are of relevance to contemporary societies globally

Impaired Thymic Selection and Abnormal Antigen-Specific T Cell Responses in Foxn1Δ/Δ Mutant Mice

Foxn1(Δ/Δ) mutant mice have a specific defect in thymic development, characterized by a block in TEC differentiation at an intermediate progenitor stage, and blocks in thymocyte development at both the DN1 and DP cell stages, resulting in the production of abnormally functioning T cells that develop from an atypical progenitor population. In the current study, we tested the effects of these defects on thymic selection.We used Foxn1(Δ/Δ); DO11 Tg and Foxn1(Δ/Δ); OT1 Tg mice as positive selection and Foxn1(Δ/Δ); MHCII I-E mice as negative selection models. We also used an in vivo system of antigen-specific reactivity to test the function of peripheral T cells. Our data show that the capacity for positive and negative selection of both CD4 and CD8 SP thymocytes was reduced in Foxn1(Δ/Δ) mutants compared to Foxn1(+/Δ) control mice. These defects were associated with reduction of both MHC Class I and Class II expression, although the resulting peripheral T cells have a broad TCR Vβ repertoire. In this deficient thymic environment, immature CD4 and CD8 SP thymocytes emigrate from the thymus into the periphery. These T cells had an incompletely activated profile under stimulation of the TCR signal in vitro, and were either hypersensitive or hyporesponsive to antigen-specific stimulation in vivo. These cell-autonomous defects were compounded by the hypocellular peripheral environment caused by low thymic output.These data show that a primary defect in the thymic microenvironment can cause both direct defects in selection which can in turn cause indirect effects on the periphery, exacerbating functional defects in T cells

The Periotest Method: Implant-Supported Framework Precision of Fit Evaluation

: In this study, the Periotest instrument was used to measure the precision of fit between cast high noble-metal frameworks and the supporting implants in a patient-simulation model. Three framework conditions and three implant-location variables were used to evaluate the rigidity of the assembly as measured by the Periotest method. The framework variables were (1) one-piece castings (OPC); (2) sectioned-soldered inaccurate castings (SSIC); and (3) sectioned-soldered accurate castings (SSAC). The implant-location variables were right anterior (RA), center (C), and left anterior (LA). Materials and Methods : The patient simulation model used consisted of three self-tapping BrÅnemark implants in a reasonable arch curvature in bovine bone. Three working casts were fabricated from the patient-simulation model using polyvinyl siloxane and tapered impression copings. From the working casts, three sets of three frameworks were fabricated as OPCs, SSICs, and SSACs using type 3 high noble alloy. The SSICs were fabricated with a quantitative misfit of 101.6 Μm at the facial surface, between the abutment-to-gold cylinder interface at the C implant location. Periotest value (PTV) measurements were made at the midfacial surface of the frameworks directly above each abutment-to-gold cylinder interface. Three measurements were made for each test condition. The data were analyzed to compare framework condition(s) and implant location(s) using ANOVA and Fisher's Protected Least Significant Difference Comparison Test. Results : The ANOVA showed that significant differences exist between the mean PTV data for framework condition and for implant location (p < .01). Significant differences were shown between the mean PTV data for the SSAC assemblies and the OPC and SSIC assemblies. The SSICs displayed a more positive (+) mean PTV than the OPCs. The OPC assemblies had a more positive mean PTV than the SSAC assemblies. The mean PTV data for the SSAC assemblies had a significantly different PTV (p < .01) than the other two framework condition assemblies. The OPC and the SSIC assemblies had PTVs that were not significantly different. The C implant location was significantly different from the RA and the LA implant locations (p < .01). The RA and the LA implant locations were not significantly different from each other. The C implant location always demonstrated the most positive mean PTV regardless of the framework condition being tested. Conclusions : The Periotest instrument quantified differences in the precision of fit between three framework conditions. The SSAC assemblies were significantly more rigid than the OPC and SSIC assemblies. The OPC and SSIC assemblies' mean PTVs were not significantly different. The mean PTVs for the C implant location and the RA and LA implant locations were significantly different (p < .01). The mean PTVs of the RA and LA implant locations were not significantly different. The implant-location PTVs followed the same rank order for all three framework conditions. The procedures used to fabricate a more precise fit between the framework and the supporting implants is influenced by the skill of the clinician and technician.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/75096/1/j.1532-849X.1996.tb00298.x.pd