Paying for school: an overview of charter school finance

This paper examines the current state of the market for charter school finance and will focus specifically on programs and financing structures for school facilities.Education - Economic aspects

Different evolutionary pathways underlie the morphology of wrist bones in hominoids

BACKGROUND The hominoid wrist has been a focus of numerous morphological analyses that aim to better understand long-standing questions about the evolution of human and hominoid hand use. However, these same analyses also suggest various scenarios of complex and mosaic patterns of morphological evolution within the wrist and potentially multiple instances of homoplasy that would benefit from require formal analysis within a phylogenetic context.We identify morphological features that principally characterize primate - and, in particular, hominoid (apes, including humans) - wrist evolution and reveal the rate, process and evolutionary timing of patterns of morphological change on individual branches of the primate tree of life. Linear morphological variables of five wrist bones - the scaphoid, lunate, triquetrum, capitate and hamate - are analyzed in a diverse sample of extant hominoids (12 species, 332 specimens), Old World (8 species, 43 specimens) and New World (4 species, 26 specimens) monkeys, fossil Miocene apes (8 species, 20 specimens) and Plio-Pleistocene hominins (8 species, 18 specimens). RESULT Results reveal a combination of parallel and synapomorphic morphology within haplorrhines, and especially within hominoids, across individual wrist bones. Similar morphology of some wrist bones reflects locomotor behaviour shared between clades (scaphoid, triquetrum and capitate) while others (lunate and hamate) indicate clade-specific synapomorphic morphology. Overall, hominoids show increased variation in wrist bone morphology compared with other primate clades, supporting previous analyses, and demonstrate several occurrences of parallel evolution, particularly between orangutans and hylobatids, and among hominines (extant African apes, humans and fossil hominins). CONCLUSIONS Our analyses indicate that different evolutionary processes can underlie the evolution of a single anatomical unit (the wrist) to produce diversity in functional and morphological adaptations across individual wrist bones. These results exemplify a degree of evolutionary and functional independence across different wrist bones, the potential evolvability of skeletal morphology, and help to contextualize the postcranial mosaicism observed in the hominin fossil record

Service centres and rural-urban interaction in the North West Midlands: an appraisal of measures of centrality within the lower orders of a central place system

Service centres and rural-urban interaction in the north-west Midlands; an appraisal of measures of centrality within the lower orders of a central place system. This thesis is concerned with a comprehensive analysis and interpretation of the functional status and pattern of distribution of service centres in a rural part of England, and with the way in which these centres interact with their hinterlands. It commences with a review of the published work in this field, partly in order to try to introduce some order and thematic classification into the diverse range of contributions from many disciplines which have followed from Christaller's work of the 1930's, and partly in order that this study may be seen as a logical progression from earlier work. The main themes of central place study are critically examined, although in order to avoid needless repetition with other studies the emphasis is laid upon material which has appeared since 1964. Some of the ideas and problems discussed are taken up in more detail in subsequent parts of the text. The first main section (Chs.3-6) deals with the measurement of settlement centrality, and the question of grouping settlements into a functional hierarchy. A measure of the functional complexity of towns and villages in the survey area is built up from information gathered from a variety of published sources, and from detailed field investigation. By the use of location coefficients an index of functional status is devised, and this is used as the basis for arranging the settlements into a ranked order of size. Retail functions are considered as but one element of a settlement's total functional composition, and in order to broaden the base of measurement, particularly for smaller centres, service functions and social facilities are also examined. In addition, the complex inter relationships of these functions, both within individual centres and across the whole range of settlements, are discussed. Several alternative approaches to the measurement of centrality are presented and compared, but it is the method based upon each settlement's provision of retail and service facilities which forms the first part of the procedure for ranking centres into a functional hierarchy. Different ranking and clustering techniques are examined, and an iterative grouping procedure which produces a logical statement of the hierarchy, together with a measure of accuracy for each inter group boundary, is explained and implemented. This method, which is described in chapter 6, scans a list of settlements, each of whose functional status is expressed as a single numerical score, and systematically amalgamates the most similar items into a subset. Similarity in this context is measured in terms of the Error Sum of Squares, and a hierarchy with eight distinct orders of settlements is described. It is suggested that measures based solely upon a centre's functional provision give a very restricted, and often inaccurate, assessment of centrality. In order to avoid this, and in an attempt to illustrate a totally different facet of the involved concept of centrality, the second section is devoted to an analysis of the use characteristics of the service centres and the nature of their zones of influence. The information upon which this section is based was mostly gathered by means of a postal questionnaire survey. An examination of the Journeys made to towns and villages for shopping and for services,forms the initial part of an investigation into the way in which these centres exert their influence over the surrounding rural areas. The frequency of such visits, and their destinations, are analysed and a nodal structure of the area is outlined. A consideration of the journeys to shop for a selected list of goods and services leads to several qualifications to the concept of the range of a good being suggested. The delimitation of urban hinterlands by both theoretical and empirical means is discussed, and several different hinterlands are constructed and compared for the towns in the study area. The boundary of a town's hinterland is in fact a zone of transition, and there is shown to be considerable overlap between the areas of influence of adjacent towns. There are also certain areas, in the interstices in the network of urban hinterlands where no town exerts a dominant influence. Individual rural people however are dominated very strongly by a single town for the provision of goods and services. Empirical hinterlands are constructed for the main urban centres, and the internal structure of these areas is examined. It is suggested that there is considerable variation in the strength of a town's influence throughout its hinterland, with the main independent variable being distance. The decline of a town's influence with distance for a number of different measures, can be described in general terms by a negative exponential function. The precise nature of this distance-decay function, and the numerical value of the exponents, is shown to vary according to the grade of the town. In this respect two distinct regimes of influence are shown to exist for grade 1 and grade 2 centres, thus confirming the distinction between these two orders previously found on the basis of their functional provision. Finally the irregularities of the hinterlands of the towns in the study area are discussed, and the characteristics of grade 1 and grade 2 hinterlands for a range of different goods and services are outlined. General conclusions are presented at the end of sections I and II, and the text is accompanied by fifty figures, thirty-six tables and five technical appendices

A comparative analysis of the hominin triquetrum (SKX 3498) from Swartkrans, South Africa

The SKX 3498 triquetrum from Member 2 at Swartkrans Cave, South Africa is the only hominin triquetrum uncovered (and published) thus far from the early Pleistocene hominin fossil record. Although SKX 3498 was found over two decades ago, its morphology has not been formally described or analysed, apart from the initial description. Furthermore, the taxonomic attribution of this fossil remains ambiguous as both Paranthropus and early Homo have been identified at Swartkrans. This analysis provides the first quantitative analysis of the SKX 3498 triquetrum, in comparison to those of extant hominids (humans and other great apes) and other fossil hominins. Although the initial description of the SKX 3498 triquetrum summarised the morphology as generally human-like, this analysis reveals that quantitatively it is often similar to the triquetra of all hominine taxa and not necessarily humans in particular. Shared hominid-like morphology between SKX 3498 and Neanderthals suggests that both may retain the symplesiomorphic hominin form, but that functional differences compared to modern humans may be subtle. Without knowledge of triquetrum morphology typical of earlier Pliocene hominins, the taxonomic affiliation of SKX 3498 remains unclear

Evidence in hand: recent discoveries and the early evolution of human manual manipulation

For several decades, it was largely assumed that stone tool use and production were abilities limited to the genus Homo. However, growing palaeontological and archaeological evidence, comparative extant primate studies, as well as results from methodological advancements in biomechanics and morphological analyses, have been gradually accumulating and now provide strong support for more advanced manual manipulative abilities and tool-related behaviours in pre-Homo hominins than has been traditionally recognized. Here, I review the fossil evidence related to early hominin dexterity, including the recent discoveries of relatively complete early hominin hand skeletons, and new methodologies that are providing a more holistic interpretation of hand function, and insight into how our early ancestors may have balanced the functional requirements of both arboreal locomotion and tool-related behaviours

mRNA and microRNA analysis reveals modulation of biochemical pathways related to addiction in the ventral tegmental area of methamphetamine self-administering rats

Background Methamphetamine is a highly addictive central nervous system stimulant with increasing levels of abuse worldwide. Alterations to mRNA and miRNA expression within the mesolimbic system can affect addiction-like behaviors and thus play a role in the development of drug addiction. While many studies have investigated the effects of high-dose methamphetamine, and identified neurotoxic effects, few have looked at the role that persistent changes in gene regulation play following methamphetamine self-administration. Therefore, the aim of this study was to identify RNA changes in the ventral tegmental area following methamphetamine self-administration. We performed microarray analyses on RNA extracted from the ventral tegmental area of Sprague–Dawley rats following methamphetamine self-administration training (2 h/day) and 14 days of abstinence. Results We identified 78 miRNA and 150 mRNA transcripts that were differentially expressed (fdr adjusted p 0.5); these included genes not previously associated with addiction (miR-125a-5p, miR-145 and Foxa1), loci encoding receptors related to drug addiction behaviors and genes with previously recognized roles in addiction such as miR-124, miR-181a, DAT and Ret. Conclusion This study provides insight into the effects of methamphetamine on RNA expression in a key brain region associated with addiction, highlighting the possibility that persistent changes in the expression of genes with both known and previously unknown roles in addiction occur

Trabecular bone structure correlates with hand posture and use in hominoids

Bone is capable of adapting during life in response to stress. Therefore, variation in locomotor and manipulative behaviours across extant hominoids may be reflected in differences in trabecular bone structure. The hand is a promising region for trabecular analysis, as it is the direct contact between the individual and the environment and joint positions at peak loading vary amongst extant hominoids. Building upon traditional volume of interest-based analyses, we apply a whole-epiphysis analytical approach using high-resolution microtomographic scans of the hominoid third metacarpal to investigate whether trabecular structure reflects differences in hand posture and loading in knuckle-walking (Gorilla, Pan), suspensory (Pongo, Hylobates and Symphalangus) and manipulative (Homo) taxa. Additionally, a comparative phylogenetic method was used to analyse rates of evolutionary changes in trabecular parameters. Results demonstrate that trabecular bone volume distribution and regions of greatest stiffness (i.e., Young's modulus) correspond with predicted loading of the hand in each behavioural category. In suspensory and manipulative taxa, regions of high bone volume and greatest stiffness are concentrated on the palmar or distopalmar regions of the metacarpal head, whereas knuckle-walking taxa show greater bone volume and stiffness throughout the head, and particularly in the dorsal region; patterns that correspond with the highest predicted joint reaction forces. Trabecular structure in knuckle-walking taxa is characterised by high bone volume fraction and a high degree of anisotropy in contrast to the suspensory brachiators. Humans, in which the hand is used primarily for manipulation, have a low bone volume fraction and a variable degree of anisotropy. Finally, when trabecular parameters are mapped onto a molecular-based phylogeny, we show that the rates of change in trabecular structure vary across the hominoid clade. Our results support a link between inferred behaviour and trabecular structure in extant hominoids that can be informative for reconstructing behaviour in fossil primates

The Primate Wrist

This book demonstrates how the primate hand combines both primitive and novel morphology, both general function with specialization, and both a remarkable degree of diversity within some clades and yet general similarity across many others. Across the chapters, different authors have addressed a variety of specific questions and provided their perspectives, but all explore the main themes described above to provide an overarching “primitive primate hand” thread to the book. Each chapter provides an in-depth review and critical account of the available literature, a balanced interpretation of the evidence from a variety of perspectives, and prospects for future research questions. In order to make this a useful resource for researchers at all levels, the basic structure of each chapter is the same, so that information can be easily consulted from chapter to chapter. An extensive reference list is provided at the end of each chapter so the reader has additional resources to address more specific questions or to find specific data

Microstructural control of ZnO films deposited by RF magnetron sputtering for ultrasound transducers

The aim of this study was to develop a deposition process using RF magnetron sputtering for the production of zinc oxide (ZnO) thin films on glass substrates. These ZnO films were to be used as the active piezoelectric element in very high frequency ultrasound transducers (> 300 MHz). In order to achieve piezoelectric activity the films had to be oriented with the c-axis of the ZnO grains perpendicular to the substrate surface. At the same time, a moderately high, at least 1 m=hr (17 nm=min) deposition rate was required for the production of practical devices. Prior to a full investigation into the sputtering parameters, an initial evaluation of the HHV Auto500 RF magnetron sputter coater system was performed. Using the original chamber configuration it was not possible to deposit ZnO at the required deposition rates. A modification of the growth chamber to allow a reduced target-substrate distance was successful in producing ZnO films at the required deposition rates. A systematic study into the deposition parameters and their effect on the ZnO film quality and deposition rates was then performed and it was found that strong c-axis oriented films could be deposited only when depositing at rates below 15 nm=min at a low substrate temperature (< 50 C). Depositions above this rate resulted in the growth of polycrystalline films. A two-step deposition process was designed to preserve c-axis orientation at high deposition rates up to 28 nm=min. The ZnO films were found to be highly strained due to inherent stress from the sputtering process. The deposition pressure was identified as the most critical deposition parameter for stress control. It was found that deposition above a critical pressure of 1:2 x10-² mbar was essential to prevent mechanical failure of the films. Post growth annealing was investigated and determined to be a viable technique to relax stress and improve the crystalline quality of the films. Finally a four-step deposition process was proposed to facilitate the growth of c-axis oriented ZnO films at relatively high deposition rates whilst minimising film stress

Single injection of novel kappa opioid receptor agonist salvinorin A attenuates expression of cocaine induced behavioral sensitization in rats

Kappa opioid receptor (KOPr) activation antagonizes many cocaine-related behaviors but adverse side effects such as sedation, dysphoria and depression limit their therapeutic use. Recently, salvinorin A (Sal A), a naturally occurring KOPr agonist, has been shown to attenuate cocaineinduced drug-seeking in a model of relapse in rats. The present study evaluated the effects of acute Sal A exposure on cocaine-induced hyperactivity and cocaine sensitization in rats. Acute treatment with the dose of Sal A that decreased drug-seeking in a previous study (0.3 mg/kg), significantly attenuated the expression of cocaine sensitization. This dose of Sal A failed to affect spontaneous locomotion or to produce a conditioned taste aversion to a novel-tasting saccharin solution. However, Sal A decreased climbing and swimming time and increased time spent immobile in the forced swim test. These findings indicate that Sal A, just like traditional KOPr agonists, attenuates cocaine-induced behavioral sensitization but does not produce the adverse effect of conditioned aversion, suggesting improved potential compliance. However, pro-depressive effects were also produced and these effects may limit the therapeutic potential