Geographic Variation in Native American Anthropometrics: a Spatial Analysis of the Boas and Gifford Datasets

In 1982, anthropometric data that had been lost for decades was rediscovered, and, with it, another chance was granted to add to our knowledge of the physical anthropology of the American Indian. Because previous spatial analysis studies either utilized only a portion of the Boas data and either utilized no statistical analyses or were not published, a more comprehensive spatial analysis is still needed. The purpose of this study is to more comprehensively re-analyze the Boas and Gifford datasets using spatial analysis methods to discover the patterns of variation revealed by the data. The following questions using spatial autocorrelation analysis were addressed. First, is there significant heterogeneity in the anthropometric data? Second, what spatial patterns are revealed by the data? Third, do the data show significant spatial structure? Fourth, do the patterns revealed by the analysis show evidence of the migration or migrations that brought Native Americans to the New World? Matrix correlation analysis utilized to examine what influence language may have had on the variation displayed in the Boas and Gifford data sets. This was thought to be important because languages that are mutually unintelligible can affect the amount of gene flow between populations. The sample sizes consisted of 9024 individuals subdivided into 120 populations for the head dimensions and 8445 individuals spread over 119 populations for the body dimensions. The variables used in the analysis consisted of 12 anthropometric dimensions and 2 additional dimensions, arm length, calculated by subtracting finger height from shoulder height, and leg length, calculated by subtracting sitting height from standing height. The head and body measurements were analyzed separately. After the data were corrected for inter-observer error, and age and sex variation, a variety of univariate and multivariate methods were used to address the above questions. Canonical discriminant analysis was performed to allow the spatial autocorrelation analysis to be done multivariately. For the spatial autocorrelation analysis, fifteen distance classes were chosen and Moran’s I and Geary’s c coefficients were calculated. Because the one-dimensional correlograms used cannot give the direction of the spatial pattern, two-dimensional correlograms were constructed. Six distance classes were used. Because spatial autocorrelation does not take the influence of language on the variation into account, matrix correlation analysis was utilized to assess this influence as well as the role of the interplay between language and geographical distance on the variability of the data. Analyses were run checking for correlations between anthropometrics and geographic distance, anthropometrics and language distance, anthropometrics and geographic distance holding language constant, and anthropometrics and language holding geographic distance constant. In order to check for boundaries to gene flow, Wombling was applied to the data. Plots were generated to show the boundaries discovered by this method. The results of the canonical discriminant analysis, spatial autocorrelation analysis, matrix correlation and Wombling revealed very little evidence for linguistic or geographic patterning in the head data, but evidence of this type was revealed by the body data. Overall, the results showed that the head data produced little evidence for inter-continental migrations, but the body data revealed evidence for at least one such migration. In addition, a complex network of gene drift, regional gene flow, and natural selection was mainly responsible for the variation in the data

Will Free Speech Get a License to Drive in Florida?: A Proposal for Distinguishing Free Speech from Government Speech in Florida Specialty Plate Cases

Specialty license plates for automobiles, which publish individual and special interest Free Speech, present a quagmire for the courts when analyzed through the lens of the First Amendment\u27s Free Speech Clause. While citizens and groups can obtain personalized license plates that publish both symbolic and written speech, state governments often exercise strict editorial control over their license plates. This regulatory scenario raises the dual questions of who is speaking - the government or the private party - and how much constitutional power the government has to engage in viewpoint restriction in regulating that speech in this traditional government forum. The United States Supreme Court has not heard any cases addressing this unique forum. State and federal courts have used several tests to decide this issue and have reached conflicting outcomes. This lack of a uniform analytical framework to guide courts in determining whether specialty license plates are private, government, or hybrid speech allows a State to engage in what is likely impermissible viewpoint restriction. Therefore, the courts must develop a clear test that determines who is speaking in this forum and how much editorial control the State has over the viewpoints that individuals and special interest groups wish to publish in this forum

Enhanced tracking system based on micro inertial measurements unit to measure sensorimotor responses in pigeons

The ability to orientate and navigate is critically important for the survival of all migratory birds and other animals. Progress in understanding the mechanisms underlying these capabilities and, in particular, the importance of a sensitivity to the Earth’s magnetic field has, thus far, been constrained by the limited number of techniques available for the analysis of often complex behavioural responses. Methods used to track the movements of animals, such as birds, have varied depending on the degree of accuracy required. Most conventional approaches involve the use of a camera for recording and then measuring an animal's head movements in response to a variety of external stimuli, such as changes in magnetic fields. However, video tracking analysis (VTA) will generally only provide a 2D tracking of head angle. Moreover, such a video analysis can only provide information about movements when the head is in view of the camera. In order to overcome these limitations, the novel invention reported here utilises a lightweight (<10g) Inertial Measurement Unit (IMU), positioned on the head of a homing pigeon, which contains a sensor with tri-axial orthogonal accelerometers, gyroscopes, and magnetometers. This highly compact (20.3×12.7×3 mm) system, can be programmed and calibrated to provide measurements of the three rotational angles (roll, pitch and yaw) simultaneously, eliminating any drift, i.e. the movement of the pigeon's head is determined by detecting and estimating the directions of motion at all angles (even those outside the defined areas of tracking). Using an existing VTA approach as a baseline for comparison, it is demonstrated IMU technology can comprehensively track a pigeon’s normal head movements with greater precision and in all 3 axes

Monomeric PcrA helicase processively unwinds plasmid lengths of DNA in the presence of the initiator protein RepD

The helicase PcrA unwinds DNA during asymmetric replication of plasmids, acting with an initiator protein, in our case RepD. Detailed kinetics of PcrA activity were measured using bulk solution and a single-molecule imaging technique to investigate the oligomeric state of the active helicase complex, its processivity and the mechanism of unwinding. By tethering either DNA or PcrA to a microscope coverslip surface, unwinding of both linear and natural circular plasmid DNA by PcrA/RepD was followed in real-time using total internal reflection fluorescence microscopy. Visualization was achieved using a fluorescent single-stranded DNA-binding protein. The single-molecule data show that PcrA, in combination with RepD, can unwind plasmid lengths of DNA in a single run, and that PcrA is active as a monomer. Although the average rate of unwinding was similar in single-molecule and bulk solution assays, the single-molecule experiments revealed a wide distribution of unwinding speeds by different molecules. The average rate of unwinding was several-fold slower than the PcrA translocation rate on single-stranded DNA, suggesting that DNA unwinding may proceed via a partially passive mechanism. However, the fastest dsDNA unwinding rates measured in the single-molecule unwinding assays approached the PcrA translocation speed measured on ssDNA

The effect of unilateral disruption of the centrifugal visual system on normal eye development in chicks raised under constant light conditions

The centrifugal visual system (CVS) comprises a visually driven isthmic feedback projection to the retina. While its function has remained elusive, we have previously shown that, under otherwise normal conditions, unilateral disconnection of centrifugal neurons in the chick affected eye development, inducing a reduced rate of axial elongation that resulted in a unilateral hyperopia in the eye contralateral to the lesion. Here, we further investigate the role of centrifugal neurons in ocular development in chicks reared in an abnormal visual environment, namely constant light. The baseline ocular phenotype of constant light-reared chicks (n = 8) with intact centrifugal neurons was assessed over a 3-week post-hatch time period and, subsequently, compared to chicks raised in normal diurnal lighting (n = 8). Lesions of the isthmo-optic tract or sham surgeries were performed in another seventeen chicks, all raised under constant light. Ocular phenotyping was performed over a 21-day postoperative period to assess changes in refractive state (streak retinoscopy) and ocular component dimensions (A-scan ultrasonography). A pathway-tracing paradigm was employed to quantify lesion success. Chicks raised in constant light conditions with an intact CVS developed shallower anterior chambers combined with elongated vitreous chambers relative to chicks raised in normal diurnal lighting. Seven days following surgery to disrupt centrifugal neurons, a significant positive correlation between refractive error asymmetry between the eyes and lesion success was evident, characterized by hyperopia in the eye contralateral to the lesion. By 21 days post-surgery, these contralateral eyes had become emmetropic, while ipsilateral eyes had developed relative axial hyperopia. Our results provide further support for the hypothesis that the centrifugal visual system can modulate eye development

An anatomical and functional characterisation of the avian centrifugal visual system: a feedback pathway from the brain to the retina

The centrifugal visual system (CVS) is a feedback pathway of predominantly visual information from the brain to both eyes, but principally to the contralateral retina. The CVS is often considered to be something of a peculiarity, regarded as being specific to birds (Aves). Indeed, so-called ‘higher’ vertebrate species are assumed not to even possess such a centrifugal pathway when, in fact, an efferent projection to the retina has been conclusively demonstrated in all vertebrate groups (including humans). Perhaps this point of view reflects the lack of progress made in the elucidation of function in the bird, the dominant model for CVS research in the 120 years since being first described. In the series of experiments presented here, I have begun to investigate the role of the CVS in the modulation of eye growth. In addition, I have addressed a number of unknowns that exist regarding the midbrain connectivity of the CVS. In a series of four parallel lesion experiments, the centrifugal efferent pathway to the retina was unilaterally disrupted in post hatch chicks, raised under different developmental conditions. Under normal visual conditions but in the absence of centrifugal efferents, eyes contralateral to the lesion developed shorter eyes and moderate, relative hyperopia (long-sightedness). In contrast, under constant light conditions, ipsilateral eyes became significantly shorter than fellow (i.e. contralateral) eyes. Compensation for, and recovery from, plus and minus lens-imposed defocus in contralateral eyes was largely unaffected. Centrifugal efferents emanate from two distinct midbrain populations: the isthmo-optic nucleus (ION) and the surrounding scattered cells within the ectopic area (EA). From experiments using pathway tracing techniques, I have demonstrated that, unlike cells of the ION, EA cells do not receive input from primary visual areas. In addition I present evidence for a possible ‘cross-talk’ pathway between centrifugal cells on either side of the midbrain, and discuss its potential involvement in the normally symmetrical eye growth

Why Isn't the head-direction system necessary for direction? Lessons from the lateral mammillary nuclei

Complex spatial representations in the hippocampal formation and related cortical areas require input from the head direction system. However, a recurrent finding is that behavior apparently supported by these spatial representations does not appear to require input from generative head direction regions, i.e., lateral mammillary nuclei (LMN). Spatial tasks that tax direction discrimination should be particularly sensitive to the loss of head direction information, however, this has been repeatedly shown not to be the case. A further dissociation between electrophysiological properties of the head direction system and behavior comes in the form of geometric-based navigation which is impaired following lesions to the head direction system, yet head direction cells are not normally guided by geometric cues. We explore this apparent mismatch between behavioral and electrophysiological studies and highlight future experiments that are needed to generate models that encompass both neurophysiological and behavioral findings

Modest Declines in Proteome Quality Impair Hematopoietic Stem Cell Self-Renewal.

Low protein synthesis is a feature of somatic stem cells that promotes regeneration in multiple tissues. Modest increases in protein synthesis impair stem cell function, but the mechanisms by which this occurs are largely unknown. We determine that low protein synthesis within hematopoietic stem cells (HSCs) is associated with elevated proteome quality in vivo. HSCs contain less misfolded and unfolded proteins than myeloid progenitors. Increases in protein synthesis cause HSCs to accumulate misfolded and unfolded proteins. To test how proteome quality affects HSCs, we examine Aarssti/sti mice that harbor a tRNA editing defect that increases amino acid misincorporation. Aarssti/sti mice exhibit reduced HSC numbers, increased proliferation, and diminished serial reconstituting activity. Misfolded proteins overwhelm the proteasome within Aarssti/sti HSCs, which is associated with increased c-Myc abundance. Deletion of one Myc allele partially rescues serial reconstitution defects in Aarssti/sti HSCs. Thus, HSCs are dependent on low protein synthesis to maintain proteostasis, which promotes their self-renewal