The structure of the QL and QT approximations to the plasma refractive index

The quasi-longitudinal and quasi-transverse approximations to the Appleton-Lassen refractive index formula for a homogeneous magneto-ionic medium have been known and used for over half a century. These formulae are derived by various methods, using the procedures of elementary analysis and algebra. In the present paper an investigation is made so as to discover why these formulae take the particular forms that are so well known. To this end, the basic propagation equations are generalized to n dimensions, and the corresponding refractive indices and their various approximations are examined in their generality. A ladder of such formulae is produced, with the three-dimensional case sitting at its lowest rung. The structure of all the formulae is thereby exhibited, and the reasons for their particular algebraic forms when n = 3 can be clearly demonstrated.     

Body Mass Estimates in Dogs and North American Gray Wolves Using Limb Element Dimensions

Body mass is a key biometric that is useful in interpreting many aspects of an animal's life history. For many species, including dogs and wolves, methods for estimating body mass are not well developed. This paper assesses the utility of using limb dimensions to predict body mass in dogs and North American wolves. Regression analyses are utilized here to explore the correlations between limb dimensions and body masses of modern dogs and wolves, all of known body mass at death. These analyses reveal that a number of limb end dimensions are correlated with body mass in both dogs and wolves. Regression formulae generated through the analyses appear to allow body masses to be predicted with relatively small margins of error, often less than 10%. Formulae are calculated for groups with and without juveniles. In some cases, the dimensions of the juvenile specimens plot distinctly from those of adults, indicating that regression formulae specifically for juvenile canids may be needed. The strength of the limb dimension correlations is then compared with that of regression formulae for dog and wolf cranio‐mandibular dimensions. For the dogs, the cranio‐mandibular dimensions appear to slightly out‐perform the limb element dimensions in predicting body mass. The wolf limb dimensions, however, always appear to provide better predictions of body mass than do the skull dimensions. The newly developed regression formulae are applied to several Middle Holocene dog skeletons from Siberia for which previous body mass estimates are available, the latter based on cranial dimensions. These two sets of estimates are then compared. The overall results of our study indicate the need for further research, particularly with larger sample sizes, including more juvenile specimens. We also argue that work on body size estimation in single dog breeds may be warranted in some cases. Copyright © 2016 John Wiley & Sons, Ltd.     

The use of dental crown heights for constructing age profiles of red deer and similar species in archaeological samples

The analysis of dental crown heights in a sample of known-age American Red deer (known in America as “elk”) has permitted the derivation of formulae for the prediction of age from crown height. The ages predicted from crown heights closely approximate true ages, when both predicted and true ages are grouped into broad, but still useful age classes. At least for the Red deer or “elk” dP₄, M₂ and M₃, age prediction formulae very similar to the empirically derived ones may be constructed by making certain hypothetical assumptions about the nature and rate of crown attrition. This suggests that these assumptions may be used to construct age prediction formulae in situations where an empirical relationship between age and crown height has not been or cannot be established. With certain provisos noted in the text, the age prediction formulae that result will probably provide reasonably reliable age profiles for the numerous ungulate species whose teeth are similar in structure to those of Red deer or “elk” and at least as hypsodont.     

Estimating Body Mass in Dogs and Wolves Using Cranial and Mandibular Dimensions: Application to Siberian Canids

Previously developed regression formulae for estimating body mass in dogs and wolves based on cranial and mandibular dimensions are evaluated using modern canid specimens of known weight at death. Some of these equations proved reliable, but others have large standard errors of estimate and likely produce unreliable mass estimates. New sets of equations for estimating body mass in dogs and wolves are produced using our datasets, including a set of equations developed from combining the dog and wolf biometric data into a single population. The resulting regression equations allow body mass to be estimated from a series of cranial and mandibular dimensions with relatively low errors. Further, our datasets include larger numbers of specimens of larger ranges of body mass than in these previous studies. When the equations are applied to a suite of dogs and one wolf from Eastern Siberia, several patterns emerge. First, hunter–gatherers' dogs in this region vary widely in terms of body size, even within a limited geographic area and time period. Some were quite large, similar in size to modern Siberian huskies. Second, pastoralists' dogs are less variable in terms of body mass, but this may reflect the nature of our samples. In particular, pastoralists' dogs nearly all were sacrificed juvenile dogs, some of which appear to have been eaten. These dogs seem to have been approached adult body size when they were selected for sacrifice. Finally, our findings help to highlight the need for further refinement in methods used to study ancient canid remains. Copyright © 2014 John Wiley & Sons, Ltd.     

Sample-specific (universal) metric approaches for determining the sex of immature human skeletal remains using permanent tooth dimensions

In this paper, three approaches for developing sample-specific sex determination methods of immature skeletal remains based on permanent tooth dimensions are proposed and tested using a sample of identified skeletons. The sample comprises adult and subadult individuals selected from the Lisbon documented skeletal collection, housed at the National Museum of Natural History in Lisbon, Portugal. Faciolingual and mesiodistal diameters were the tooth dimensions utilized. In the first approach, sex-specific logistic regression formulae based on adult tooth dimensions are developed and then used to determine the sex of the subadult sample. The second and third approaches are based on the sectioning point procedure, which uses the overall mean of a measurement (tooth diameter) collected from the sample as the discriminant criteria for determining the sex of the individuals in that sample. While in the second approach the adult overall mean of each dimension is used as the discriminant criteria for determining the sex of the subadults, in the third approach it is the subadult overall mean of each dimension that comprises the discriminant criteria that is applied back to the subadults for determining sex. Results show that the canines are the teeth with the highest sexual dimorphism and methods of sex determination based on canine dimensions provide correct allocation accuracies between 58.8% and 100% depending on the diameter and the approach that is being used. Canine faciolingual dimensions provide the best overall results. Combinations of measurements from the same and different teeth do not increase significantly the accuracy of the methods and approaches. Some of the problems of subadult sex determination methods based on adult tooth dimensions result from differing levels of sexual dimorphism between the adult and subadult segment of the sample. Mortality or cultural bias may increase or decrease the sexual dimorphism of the subadults compared to the adults. Small subadult samples utilized in this study may also raise questions regarding the accuracy of the three different sample-specific approaches. However, high consistency of results using the canine and different approaches, suggests that adult and subadult canine dimensions can be reliable sex discriminators of immature skeletal remains in archaeological samples. The major advantage of the approaches presented here is that they can be used to derive sample-specific methods and, therefore, eliminate the problem of applying morphological or metric methods to individuals originating from a population that differs from the one that contributed to the development of the method.     

Refining the Quadratic Crown Height Method of age estimation: do elk teeth wear quadratically with age?

Teeth are the basis for the best methods for estimating the age-at-death of archaeological and paleontological faunal remains, because they change by eruption and wear throughout an individual's life and because they preserve well. However, age-at-death can be difficult to estimate when teeth are isolated or when no known-age reference sample is available. For these reasons, researchers developed the Quadratic Crown Height Method (QCHM), a set of quadratic formulae that can be used to predict age-at-death from tooth crown height, when unworn crown height and the ages when the tooth erupts and when its crown height should reach zero can be estimated. Previous tests of the QCHM suggest that modified equations could improve the method. Here, we use crown height measurements on a sample of 226 known-age Rocky Mountain elk (Cervus elaphus) to perform such modifications. We adjust the age at which each tooth type's crown height reaches zero from the species' potential ecological longevity or average maximum life span to an age that we empirically estimate for each tooth type. We also empirically assess whether for different elk teeth the exponent in the QCHM formula is actually equal to 2; it is for M1, but for P4 it is about 1, indicating a roughly linear relationship. The exponents for M2 and M3 are intermediate, being closer to 1.5. Because different teeth wear at different rates and wear completely away at different ages, we recommend that researchers use the modified equations provided here to estimate age-at-death for samples of Cervus elaphus.     

Overpressure in the Malay Basin and prediction methods

Predrill overpressure prediction is important for well planning and migration modeling for prospect evaluation. The Eaton (Journal of Petroleum Technology, 24 , 1972, 929) and Bowers (SPE Drilling & Completion, 10 , 1995, 89) methods are used worldwide for postdrill overpressure prediction using sonic log and predrill overpressure prediction using seismic interval velocity. In this research, these two methods were used for overpressure prediction using 3D anisotropic prestack depth‐migrated seismic interval velocity in a field of the Malay Basin. In the shallow overpressured zone, where the mechanism of overpressure is undercompaction, the onset of overpressure was predicted reasonably well using the Eaton and Bowers methods with their standard parameters (i.e., Eaton exponent 3 and Bowers loading curve) for seismic velocity. However, in the deep overpressured zone, where fluid expansion is the cause of overpressure generation, these methods underpredicted the high overpressure. In the deep overpressured zone, the overpressures were better predicted by applying a correction to the Eaton method. On the other hand, the Bowers unloading parameters for the fluid expansion mechanisms did not show any significant effect on overpressure prediction. Hence, in the study area, the Bowers method is not effective for 3D overpressure prediction using seismic velocity, whereas the Eaton method is more robust and can be used for 3D overpressure prediction from seismic velocity.     

Disentangling long bones of foxes (Vulpes vulpes and Alopex lagopus) from arctic archaeological sites

To discern the presence of two anatomically close species within an archaeological assemblage is always a problem for the analyst. A particularly interesting case is the distinction between the red fox (Vulpes vulpes) and the arctic fox (Alopex lagopus), which is often determined using non-rigorous criteria and producing results that must be regarded with caution. Classical methods for separating these two species and determining sexual dimorphism, and eventually the sex ratio, such as analyses using uni- and bivariate plots, are based on arbitrarily fixed limits between sexes. In this text, a more robust statistical method termed mixture analysis (MA) is used to determine the species of limb bones from foxes. First, the MA is applied to a sample of each species using metric data taken from a collection of present-day fox skeletons. Afterwards, the MA is applied to archaeological samples dated to the Dorset period and retrieved from the Tayara site (near Salluit, South Hudson Strait, Nunavik). The results clearly demonstrate that the greatest length (GL) of long bones, especially the humerus and tibia, is the best measurement for distinguishing the species, followed by the distal breadth and the proximal breadth; and that GL is better suited for sexing foxes. The results of MA applied to the Tayara site collection lead to the conclusion that the red fox is present along with the arctic fox among the assemblage, and that there is no fox body size change during the last two millennia in the Eastern Arctic.     

EXAMINING ICHTHYOFAUNAL REMAINS FOR EVIDENCE OF FISHING TECHNOLOGIES EMPLOYED IN GEORGIA ESTUARIES DURING THE LATE ARCHAIC PERIOD

Abstract

Previous analyses of vertebrate collections from Late Archaic (ca. 4500–3000 B.P.) shell rings on numerous Georgia sea islands indicate that fishes comprise the majority of individuals. Material culture associated with fishing is not recovered from these sites, however. Two methods are used to determine how people captured fishes using ichthyofaunal remains from five shell rings. Fish taxa are characterized according to schooling or nonschooling behaviors. Archaeological specimens representing the minimum number of individuals from the three most abundant fish families also are measured, and standard lengths of fish individuals are estimated using allometric formulae. The distribution of standard lengths are compared to expected size distributions of populations captured with specific fishing technologies, such as weirs, traps, nets, hooks, and spears. Results suggest that Late Archaic people of the Georgia coast fished estuaries using mass-capture technologies, such as weir, trap, and net fishing.     

The use of summed radiocarbon probability distributions in archaeology: a review of methods

Using a database of Australian archaeological radiocarbon dates (n = 2996), this paper explores three key methodological issues associated with the use of summed probability plots of radiocarbon data: 1) the minimum sample size needed for a statistically reliable plot; 2) the effect of radiocarbon calibration on the structure of these plots; and 3) the application of a taphonomic correction to such time-series data. The results identify several protocols, recommended as best-practice when using summed probability plots: 1) a minimum sample size of 500 radiocarbon dates should be used, and the sample size and the mean of the standard deviations of the radiocarbon dates (ΔT) in the sample should both be reported; 2) a moving average trendline of 500-800 years should be used to offset the effects of the calibration process; and 3) Surovell et al. “Correcting temporal frequency distributions for taphonomic bias” [Journal of Archaeological Science 36 (2009) 1715-1724] is explored, with modifications and temporal limits (<25,000 cal years BP) proposed. Correction of time-series data using theoretical taphonomic correction curves is useful as a heuristic tool but can obscure real trends if applied routinely. Comparison between summed probability plots and other occupation data is presented and shows good correlation. However it is recommended that plots are supplemented by other archaeological indices and the cross-comparison of such multiple proxies will strengthen identification of occupation trends.     

Starch grain characterization of Prosopis chilensis (Mol.) Stuntz and P. flexuosa DC,and the analysis of their archaeological remains in Andean South America

The fruit (pods) of Prosopis (Fabaceae) are frequently recovered from pre-Hispanic Argentinian archaeological sites, suggesting that this genus was of importance in ancient economies in this region. Yet it is only recently that archaeobotanists have begun to carry out systematic research into this genus. Therefore many questions remain to be addressed concerning the food value of Prosopis fruit, and its potential contribution. This paper examines starch from the pods of two species, Prosopis flexuosa and Prosopis chilensis, for the purposes of describing and classifying their morphological features and biometrical parameters. Pods of both species were gathered from two extremes (northern and southern) of the Hualfín Valley, Catamarca, Argentina. Starch abundance is estimated and compared with that of Zea mays, an economically important plant with high concentrations of starch. This paper reveals that Prosopis pods contain very low amounts of starch compared to starch-rich edible species. Despite this, the recovery of Prosopis starch grains can be successfully used to assess archaeological tool uses. Prosopis starch grains were found to be highly variable in shape. Grain size ranged between 10 and 20 μm. Granule irregularity and the high birefringence under polarized light are two of the most important diagnostic features. No significant statistical differences were found in the structure (morphology, size and hilum) of the starch of the same species from both localities. Finally, the implications for the role of this plant in past societies are discussed.     

The effect of a priori knowledge on parameter estimation errors with applications to incoherent scatter

The dependence of the width of the a posteriori distribution (i.e. parameter estimation error) in a multiparameter fit on the a priori width of another parameter is studied in the framework of linear statistical inversion theory. An exact formula is given which makes it possible to estimate how accurate the a priori information on a given parameter must be in order to obtain the other parameter with a prescribed accuracy. These estimates are useful in those cases where some errors are strongly correlated, like the ion temperature and the O⁺ content in incoherent scatter measurements with the EISCAT UHF radar. The dependence of the solution on the accuracy of the power profile estimates is given. Likewise, the behaviour of the error when a linear combination of the parameters is known exactly is given. The formulae given have a very simple geometrical meaning, and together they give a complete solution to the problem of estimating the accuracies in a multiparameter fit when a linear combination of the variables is known with a prescribed accuracy. It is shown that under the conditions considered in this paper, oxygen content can be determined to an accuracy of 10 % when the ion temperature is known to within 7 %, if we can assume that the collision frequency is zero.     

Sources of variation in carnivore tooth-mark frequencies in a modern spotted hyena (Crocuta crocuta) den assemblage,Amboseli Park,Kenya

Distributions and frequencies of carnivore tooth-marks on large mammal long-bone fragments are commonly used to infer the timing of hominin and carnivore access to prey resources in archaeofaunal assemblages. The strength of these inferences, however, is limited by a broad and currently inexplicable range of tooth-mark frequencies across experimental and archaeological assemblages. Controlling for this variation first requires that the sources be identified. Several sources of variation are examined here in an analysis of tooth-marked bone recovered from a modern spotted hyena (Crocuta crocuta) den assemblage in Amboseli Park, Kenya. Results indicate that tooth-mark frequencies: (1) depend on fragment size, (2) vary across mammals of different size classes, (3) are highly variable across equivalent portions of different long-bone elements, and (4) on certain long-bone portions are correlated with bone density and can be depressed in archaeological assemblages subjected to density-mediated attrition. Stronger inferences based on tooth-mark frequencies will require that such variation be taken into consideration, and methods for doing so are suggested.     

Principles and Methods of Regional Geographical Prediction

A research methodology for purposes of geographical prediction is proposed. A region is considered the most likely object of geographical prediction, which is designed to forecast the most likely modifications of the natural environment under the impact of human activity, and the expected working and living conditions for man in the altered environment. The predictive process should focus on phenomena and processes that change through time and can be tested on the basis of known regularities and relationships. Predictive techniques may include both general scientific methods used for prediction and cause-and-effect relationships peculiar to geography. Among the most useful general techniques are extrapolation, expert evaluations, model building and comparative methods.     

A Model to Relate the Size of the Central Business District to the Population of a City

A set of dynamic models of CBD growth are developed. They hypothesize that growth rates depend upon the population growth rate together with the increasing unwillingness of people to travel to the city center as city size increases. A prediction of the model is that absolute decreases in CBD size can occur associated simply with population growth rather than technological change as is usually postulated. The models are tested using retail sales data for the United States. Good predictions are generally found, especially when the unique CBD of New York City is removed from the data set. However, the model which has the greatest theoretical validity relative to central place theory does not have the best fit to the data. Implications of this are discussed, along with those of utilizing transformations in regression models.     

东北地区城市规模分布的分形特征

本文借助Zipf公式考察了东北地区(1994)城市规模分布的分形几何特征,发现辽宁省城市规模分布具有双分形结构,吉林省城市规模分布具有单分形结构,而黑龙江省城市规模分布则具有局部分形结构,整个东北地区的城市规模分布呈现局部分形图式,但显示出双分形迹象。文章得出了一些重要的理论结论,并为东北三省的城市体系等级结构优化提出了若干建议。     

Diaphyseal growth in a nineteenth century skeletal sample of subadults from St Thomas' church,Belleville, Ontario

This study presents skeletal growth data for a nineteenth century church cemetery sample from Belleville, Ontario. Skeletal growth profiles (SGPs), plotting measurements of growth against age estimated by tooth formation, were constructed for the sample. Means and confidence intervals for 1-year cohorts up to 12 years of age are presented for each of the long bones, the ilium and scapula. Comparison of the SGPs created for this sample with modern and archaeological samples demonstrates that the nineteenth century Belleville children followed a growth pattern similar to their modern counterparts, at least until 12 years of age. It is recommended that these data can be used by other investigators as a comparative sample of nineteenth century children; they can also be used as standards of growth for the purpose of estimating age from diaphyseal lengths for other archaeological samples of similar temporal context and population affinities. It is argued that confidence intervals rather than standard deviations be used to report variation, as the former controls for sample size as well as variance.     

The craniology and relationships of four species of bos 1. Basic craniology: Bos taurus L. and its absolute size

This paper is the first of a series on the craniology of four species of Bos. Here (and in the next paper) Bos taurus in Britain is used to establish a basic craniology for the genus. In the initial sections notes are made on the nomenclature, material available, history, and age assessment of B. taurus. The subsequent section deals with the effects of sex, age and breed on absolute size.The results show that Bos taurus is very variable, particularly in the length of the horncore. Sex influences certain dimensions very greatly, particularly those of breadth. Although the horns of cows are often longer than those of bulls of the same breed the horncores may be shorter in cows. In studying the effects of age it can be seen that growth rates are initially very high, slowing down at about three years of age. Tooth row length decreases with age and hence it is a particularly unreliable indicator of size. Obviously breed affects size and it has been possible to divide the skulls studied into size groups which correspond well with known body weights.     

Identifying bilateral pairs of deer (Odocoileus sp.) bones: how symmetrical is symmetrical enough?

Identifying bilaterally paired bones in zooarchaeological collections rests on the assumption that left and right skeletal elements from the same organism will be symmetrical. Bilaterally paired bones in an individual are, however, typically asymmetrical to some degree, demanding that the question “How symmetrical is symmetrical enough to identify a bilateral pair?” be answered with control data. The degree of symmetry chosen, or tolerance, will influence both how many true pairs in an archaeological collection are not identified (type I error) and how many false pairs are identified (type II error). Bivariate measures of 60 pairs of astragali and 48 pairs of distal humeri of deer (Odocoileus virginianus and O. hemionus) indicate that both sorts of error are frequent even when a conservative level of tolerance (≤average asymmetry) is used. Simulation of an archaeological collection indicates that as sample size increases, frequencies of both kinds of error increase. Application of the matching criteria and tolerance level to an archaeological collection underscores that the analytical requirements of identifying paired bones are steep.     

Lexsyg — A new system for luminescence research

The newly developed lexsyg system by Freiberg Instruments is a versatile luminescence reader, suited for research on the luminescence of materials, fundamental research in luminescence dating, but also for routine mass measurements in retrospective dosimetry as well as in dating application. The 80 sample storage wheel is disconnected from the measurement chamber and therefore crosstalk of optical stimulation is absent and cross-irradiation is negligible from the α- and β-sources, which are providing very uniform irradiations, with the latter especially designed for radiofluores-cence (RF) measurement. Optical excitation sources and filter wheels to vary detection wavelengths can be programmed to change at almost any time within measurement sequences, including the auto-mated change of an optional wheel holding up to four different detectors. Thermoluminescence meas-urements and preheating are possible with a versatile heater, which can be programmed for linear or non-linear heating or cooling, as well as holding a temperature constant. Rates as well as durations can be varied, together with individual ramping, staging and cooling for an almost unlimited number of steps. Violet- and IR-lasers, green and blue LED-arrays can be operated in continuous (CW) or modulated mode (linear/non-linear), and optionally for pulsed as well as time resolved luminescence detection. Six arrays of power LEDs allow the simulation of different bleaching regimes (‘solar simu-lator’), while luminescence detection can be achieved by a variety of photomultiplier tubes and by CCD cameras for spatially resolved measurements and luminescence spectra.