88 research outputs found
An Analysis of Morphological Differences in the Femoral Diaphyseal Midshaft Between Fossil and Modern Humans
The understanding of morphological variation between fossil and modern humans
is critical to the discussion of evolutionary processes within the Homo lineage.
Neanderthals are recognizably distinct in their morphology from Late Pleistocene Homo
sapiens and recent modern humans, especially in the femoral midshaft cross-section.
These lineages are often assumed to be independent when applying statistical methods to
account for these morphological differences. The shared evolutionary history of fossil
and modern humans, however, increases the likelihood that the distinction in observable
traits cannot entirely be attributed to divergent selective pressures; morphological
variation is obscured by phylogenetic signal and therefore violates assumptions of
statistical independence. In order to understand the observed variation between these
groups, phylogenetic signal must be taken into account.
To test for phylogenetic signal in the femoral cross-section in recent human
evolution, geometric morphometric shape data was taken from fossil groups
(Neanderthals and Late Pleistocene Homo sapiens) and compared to a global recent
modern human sample. This shape data was isolated from other morphological
constraints through Procrustes superimposition and mapped onto a phylogeny created
from mitochondrial genomes from geographic and temporally comparable populations.
The trends in femoral midshaft cross-sectional shape variation were examined through
Principal Component Analyses and Canonical Variate Analyses and showed
concentrated shape change in the region of the pilaster. A permutation test indicated that
phylogenetic signal is present in the femoral midshaft shape. The presence of this signal
between fossil and modern human groups stresses the importance of taking into account,
and controlling for, shared evolutionary history in comparative analyses. In order to
understand the nature of the phylogenetic signal present in the femoral midshaft,
independent contrasts were calculated and a multivariate regression was performed to
test for the impact of evolutionary allometry.
The results showed that allometric changes throughout modern and fossil human
evolutionary history had an insignificant impact on changes in shape, explaining only
20% of shape variation. This, therefore, suggests that the observed shape changes at the
femoral midshaft between these groups are not due to evolutionary allometry but can be
attributed to other factors, such as behavioral, genetic, or environmental pressures
An Analysis of Morphological Differences in the Femoral Diaphyseal Midshaft Between Fossil and Modern Humans
The understanding of morphological variation between fossil and modern humans
is critical to the discussion of evolutionary processes within the Homo lineage.
Neanderthals are recognizably distinct in their morphology from Late Pleistocene Homo
sapiens and recent modern humans, especially in the femoral midshaft cross-section.
These lineages are often assumed to be independent when applying statistical methods to
account for these morphological differences. The shared evolutionary history of fossil
and modern humans, however, increases the likelihood that the distinction in observable
traits cannot entirely be attributed to divergent selective pressures; morphological
variation is obscured by phylogenetic signal and therefore violates assumptions of
statistical independence. In order to understand the observed variation between these
groups, phylogenetic signal must be taken into account.
To test for phylogenetic signal in the femoral cross-section in recent human
evolution, geometric morphometric shape data was taken from fossil groups
(Neanderthals and Late Pleistocene Homo sapiens) and compared to a global recent
modern human sample. This shape data was isolated from other morphological
constraints through Procrustes superimposition and mapped onto a phylogeny created
from mitochondrial genomes from geographic and temporally comparable populations.
The trends in femoral midshaft cross-sectional shape variation were examined through
Principal Component Analyses and Canonical Variate Analyses and showed
concentrated shape change in the region of the pilaster. A permutation test indicated that
phylogenetic signal is present in the femoral midshaft shape. The presence of this signal
between fossil and modern human groups stresses the importance of taking into account,
and controlling for, shared evolutionary history in comparative analyses. In order to
understand the nature of the phylogenetic signal present in the femoral midshaft,
independent contrasts were calculated and a multivariate regression was performed to
test for the impact of evolutionary allometry.
The results showed that allometric changes throughout modern and fossil human
evolutionary history had an insignificant impact on changes in shape, explaining only
20% of shape variation. This, therefore, suggests that the observed shape changes at the
femoral midshaft between these groups are not due to evolutionary allometry but can be
attributed to other factors, such as behavioral, genetic, or environmental pressures
“PROSPERING BECAUSE THAT’S ITS HISTORY”: BLACK RESILIENCE AND HONORS DEVELOPMENT IN HIGHER EDUCATION: MORGAN STATE UNIVERSITY AND THE STATE OF MARYLAND, 1867-1988
This study explores the origins and development of honors education at a Historically Black College and University (HBCU), Morgan State University, within the context of the Maryland higher education system. During the last decades, public and private institutions have invested in honors experiences for their high-ability students. These programs have become recruitment magnets while also raising institutional academic profiles, justifying additional campus resources. The history of higher education reveals simultaneous narratives such as the tension of post-desegregated Black colleges facing uncertain futures; and the progress of the rise and popularity of collegiate honors programs. Both accounts contribute to tracing seemingly parallel histories in higher education that speaks to the development of honors education at HBCUs. While the extant literature on honors development at Historically White Institutions (HWIs) of higher education has gradually emerged, our understanding of activity at HBCUs is spotty at best. One connection of these two phenomena is the development of honors programs at HBCUs. Using Morgan State University, I examine the role and purpose of honors education at a public HBCU through archival materials and oral histories. Major unexpected findings that constructed this historical narrative beyond its original scope were the impact of the 1935/6 Murray v Pearson, the first higher education desegregation case. Other emerging themes were Morgan’s decades-long efforts to resist state control of its governance, Maryland’s misuse of Morrill Act funds, and the border state’s resistance to desegregation. Also, the broader histories of Black education, racism, and Black citizenship from Dred Scott and Plessy, the 1863 Emancipation Proclamation to Brown, inform this study. As themes are threaded together, Critical Race Theory provides the framework for understanding the emerging themes. In the immediate wake of the post-desegregation era, HBCUs had to address future challenges such as purpose and mission. Competing with HWIs for high-achieving Black students was one of the unanticipated consequences of the Brown decision. Often marginalized from higher education research literature, this study will broaden the research repository of honors education by documenting HBCU contributions despite a challenging landscape
Sensors, measurement fusion and missile trajectory optimisation
When considering advances in “smart” weapons it is clear that air-launched systems have adopted an integrated approach to meet rigorous requirements, whereas air-defence systems have not. The demands on sensors, state observation, missile guidance, and simulation for air-defence is the subject of this research. Historical reviews for each topic, justification of favoured techniques and algorithms are provided, using a nomenclature developed to unify these disciplines. Sensors selected for their enduring impact on future systems are described and simulation models provided. Complex internal systems are reduced to simpler models capable of replicating dominant features, particularly those that adversely effect state observers. Of the state observer architectures considered, a distributed system comprising ground based target and own-missile tracking, data up-link, and on-board missile measurement and track fusion is the natural choice for air-defence. An IMM is used to process radar measurements, combining the estimates from filters with different target dynamics. The remote missile state observer combines up-linked target tracks and missile plots with IMU and seeker data to provide optimal guidance information. The performance of traditional PN and CLOS missile guidance is the basis against which on-line trajectory optimisation is judged. Enhanced guidance laws are presented that demand more from the state observers, stressing the importance of time-to-go and transport delays in strap-down systems employing staring array technology. Algorithms for solving the guidance twopoint boundary value problems created from the missile state observer output using gradient projection in function space are presented. A simulation integrating these aspects was developed whose infrastructure, capable of supporting any dynamical model, is described in the air-defence context. MBDA have extended this work creating the Aircraft and Missile Integration Simulation (AMIS) for integrating different launchers and missiles. The maturity of the AMIS makes it a tool for developing pre-launch algorithms for modern air-launched missiles from modern military aircraft.EThOS - Electronic Theses Online ServiceGBUnited Kingdo
The Irish Rover: Phil Lynott and the Search for Identity
Phil Lynott, the lead singer of the rock band Thin Lizzy, was a complex character. An illegitimate black child who grew up in a working-class, Catholic district of Dublin, Ireland in the 1950s, Lynott spent his life searching for a sense of belonging, something which he explored through rock and roll. This study uses Lynott’s song lyrics to investigate his quest for identity. In particular, it identifies the many recurring themes and archetypes in his music that offered multifaceted self-portraits of his internal conflict between being black, Irish, illegitimate, a rockstar, a Lothario, a son, a father, and a husband, all at the same time
Relativistic Binaries in Globular Clusters
Galactic globular clusters are old, dense star systems typically containing
10\super{4}--10\super{7} stars. As an old population of stars, globular
clusters contain many collapsed and degenerate objects. As a dense population
of stars, globular clusters are the scene of many interesting close dynamical
interactions between stars. These dynamical interactions can alter the
evolution of individual stars and can produce tight binary systems containing
one or two compact objects. In this review, we discuss theoretical models of
globular cluster evolution and binary evolution, techniques for simulating this
evolution that leads to relativistic binaries, and current and possible future
observational evidence for this population. Our discussion of globular cluster
evolution will focus on the processes that boost the production of hard binary
systems and the subsequent interaction of these binaries that can alter the
properties of both bodies and can lead to exotic objects. Direct {\it N}-body
integrations and Fokker--Planck simulations of the evolution of globular
clusters that incorporate tidal interactions and lead to predictions of
relativistic binary populations are also discussed. We discuss the current
observational evidence for cataclysmic variables, millisecond pulsars, and
low-mass X-ray binaries as well as possible future detection of relativistic
binaries with gravitational radiation.Comment: 88 pages, 13 figures. Submitted update of Living Reviews articl
- …