Population structure of Lower Nubia in the Mesolithic-Christian groups

For almost 100 years, population structure in Nubians has been speculated upon. Initially, most scholars contended that Nubian biological evolution was the product of biological diffusion, or extraregional gene flow, from the different populations they came into contact with. In 1968, Adams put forth a new way to look at the archaeological record. He argued that the archaeological record was reflective of an in situ change, where Nubians evolved culturally without influences from other populations. Later, Carlson and Van Gerven (1979) hypothesized that the same forces that formed the archaeological record were also operating biologically. Since Adams and Carlson and Van Gerven suggested an alternative way to look at Nubian cultural and biological evolution, most research (with the exception of DNA studies) have concurred with their conclusions. The body of research into Nubian biological evolution is vast and incorporates DNA, craniometrics, dental metrics, and dental nonmetrics.However, very little work has been done with cranial discrete traits. In this dissertation, seven questions and their corollaries of Nubian population structure will be examined utilizing cranial discrete traits. Population genetics statistics for quantitative traits have become popular in craniometric data studies. Because of their effectiveness in deciphering subtle aspects of population structure, this dissertation will adapt the continuous population genetics statistics for use with categorical or discrete data. The results of the inquiry into Nubian population structure depict a complex pattern of biological evolution that suggests in situ evolution did not operate alone. Rather, sometimes in situ evolution occurred, while other times biological diffusion influenced their evolution. These interesting results mainly support the DNA evidence, which found evidence of multiple migrations across Nubia (Fox 1997; Krings et al. 1999).Sample size may have affected these results, as several of the samples numbered less than 30. However, small samples should not be ignored because they can contribute much information about past populations. Furthermore, this dissertation successfully modified and applied population genetics statistics to categorical data and can serve as a stepping stone for more sophisticated techniques to be applied to the methodology employed within

Magnetic field induced nutation of the exciton-polariton polarization in (Cd,Zn)Te crystals

We study the polarization dynamics of exciton-polaritons propagating in sub-mm thick (Cd,Zn)Te bulk crystals using polarimetric time-of-flight techniques. The application of a magnetic field in Faraday geometry leads to synchronous temporal oscillations of all Stokes parameters of an initially linearly or circularly polarized, spectrally broad optical pulse of 150 fs duration propagating through the crystal. Strong dispersion for photon energies close to the exciton resonance leads to stretching of the optical pulse to a duration of 200$-$300 ps and enhancement of magneto-optical effects such as the Faraday rotation and the non-reciprocal birefringence. The oscillation frequency of the exciton-polariton polarization increases with magnetic field $B$, reaching 10 GHz at $B\sim 5$T. Surprisingly, the relative contributions of Faraday rotation and non-reciprocal birefringence undergo strong changes with photon energy, which is attributed to a non-trivial spectral dependence of Faraday rotation in the vicinity of the exciton resonance. This leads to polarization nutation of the transmitted optical pulse in the time domain. The results are well explained by a model that accounts for Faraday rotation and magneto-spatial dispersion in zinc-blende crystals. We evaluate the exciton $g$-factor $|g_{\rm exc}|=0.2$ and the magneto-spatial constant $V= 5 \times 10^{-12}$ eVcm$\textup{T}^{-1}$.Comment: 11 pages, 6 figure

The Benefits of Peer Review and a Multisemester Capstone Writing Series on Inquiry and Analysis Skills in an Undergraduate Thesis.

This study examines the relationship between the introduction of a four-course writing-intensive capstone series and improvement in inquiry and analysis skills of biology senior undergraduates. To measure the impact of the multicourse write-to-learn and peer-review pedagogy on student performance, we used a modified Valid Assessment of Learning in Undergraduate Education rubric for Inquiry and Analysis and Written Communication to score senior research theses from 2006 to 2008 (pretreatment) and 2009 to 2013 (intervention). A Fisher-Freeman-Halton test and a two-sample Student's t test were used to evaluate individual rubric dimensions and composite rubric scores, respectively, and a randomized complete block design analysis of variance was carried out on composite scores to examine the impact of the intervention across ethnicity, legacy (e.g., first-generation status), and research laboratory. The results show an increase in student performance in rubric scoring categories most closely associated with science literacy and critical-thinking skills, in addition to gains in students' writing abilities

More Automation and Less Cognitive Control of Imagined Walking Movements in High- Versus Low-Fit Older Adults

Using motor imagery, we investigated brain activation in simple and complex walking tasks (walking forward and backward on a treadmill) and analyzed if the motor status of older adults influenced these activation patterns. Fifty-one older adults (64–79 years of age) were trained in motor execution and imagery and then performed the imagination task and two control tasks (standing, counting backward) in a horizontal position within a 3T MRI scanner (first-person perspective, eyes closed). Walking backward as compared to walking forward required larger activations in the primary motor cortex, supplementary motor area, parietal cortex, thalamus, putamen, and caudatum, but less activation in the cerebellum and brainstem. Motor high-fit individuals showed more activations and larger BOLD signals in motor-related areas compared to low-fit participants but demonstrated lower activity in the dorsolateral prefrontal cortex. Moreover, parietal activation in high-fit participants remained stable throughout the movement period whereas low-fit participants revealed an early drop in activity in this area accompanied by increasing activity in frontal brain regions. Overall, walking forward seemed to be more automated (more activation in cerebellum and brainstem), whereas walking backward required more resources, e.g., for visual-spatial processing and sensorimotor control. Low-fit subjects in particular seemed to require more cognitive resources for planning and controlling. High-fit subjects, on the contrary, revealed more movement automation and a higher “attention span.” Our results support the hypothesis that high fitness corresponds with more automation and less cognitive control of complex motor tasks, which might help to free up cognitive resources

Evaluating Nubian Population Structure from Cranial Nonmetric Traits: Gene Flow, Genetic Drift, and Population History of the Nubian Nile Valle

Paleolithic archaeological and skeletal remains from the Nile Valley have yielded a complex picture of life along the river. Sociocultural and sociopolitical events during this timeframe shaped population structure, while gene flow and genetic drift further developed it. In this paper, we take a population genetics approach to modeling Nubian biological relationships in an effort to describe how an accumulation of events formed Nubian population structure. A variety of Nubian samples were utilized, spanning the Mesolithic-Christian time periods, and geographically, from just above the first through the third cataracts. Population genetics statistics were employed to estimate and depict biological affinities (Mahalanobis D2 with a tetrachoric matrix, principal coordinates analysis, Fst, and Relethford Blangero residuals) and supplemented by spatial-temporal modeling (Mantel tests and PROTESTs). Variation is high amongst these groups, indicating an intricate pattern of relationships in their population history where similar levels of gene flow probably stemmed from extensive cultural contact with Egypt and other populations in a variety of contexts. Genetic drift is also apparent in some of these sites, which is consistent with social and political histories of these groups. Traditional modeling of spatial-temporal patterning was not successful, which may be attributed to the non-linear, loose clustering of Nubian groups by site. Collectively, the archaeological, biological, and environmental evidence support the ideas of multiple populations living in Lower Nubia during the Paleolithic, and/or a new population entering the area and shaping Nubian population structure

A Map of Periodicity Orthogonal to Frequency Representation in the Cat Auditory Cortex

Harmonic sounds, such as voiced speech sounds and many animal communication signals, are characterized by a pitch related to the periodicity of their envelopes. While frequency information is extracted by mechanical filtering of the cochlea, periodicity information is analyzed by temporal filter mechanisms in the brainstem. In the mammalian auditory midbrain envelope periodicity is represented in maps orthogonal to the representation of sound frequency. However, how periodicity is represented across the cortical surface of primary auditory cortex (AI) remains controversial. Using optical recording of intrinsic signals, we here demonstrate that a periodicity map exists in primary AI of the cat. While pure tone stimulation confirmed the well-known frequency gradient along the rostro-caudal axis of AI, stimulation with harmonic sounds revealed segregated bands of activation, indicating spatially localized preferences to specific periodicities along a dorso-ventral axis, nearly orthogonal to the tonotopic gradient. Analysis of the response locations revealed an average gradient of − 100° ± 10° for the periodotopic, and −12° ± 18° for the tonotopic map resulting in a mean angle difference of 88°. The gradients were 0.65 ± 0.08 mm/octave for periodotopy and 1.07 ± 0.16 mm/octave for tonotopy indicating that more cortical territory is devoted to the representation of an octave along the tonotopic than along the periodotopic gradient. Our results suggest that the fundamental importance of pitch, as evident in human perception, is also reflected in the layout of cortical maps and that the orthogonal spatial organization of frequency and periodicity might be a more general cortical organization principle

Estudio de condiciones técnicas de servicio para la implantación de vehículos ferroviarios híbridos para trabajos de mantenimiento de vías y catenarias

En el marco de la colaboración entre la UPC (Universistat Politècnica de Catalunya) y la TMB (Transport Metropolitans de Barcelona), este Proyecto Final de Carrera trata de las condiciones técnicas de servicio para la implantación de vehículos híbridos para el mantenimiento de vías y catenarias. Hemos estudiado los problemas planteados por el uso de máquinas térmicas de tipo Diesel dentro de los túneles del metro de Barcelona, que son la presencia de gases tóxicos de combustión, ruido, y calor en lugares de trabajo confinados. La degradación consecuente de la salud de los operarios también se ha podido admitir como un riesgo económico por la empresa TMB, además del posible incumplimiento de las normas medio-ambientales europeas. Para resolver este problema, la TMB tiene planteado cambiar sus dresinas térmicas por dresinas utilizando un medio de propulsión de tipo híbrido. Para elegir el mejor sistema de hibridación a partir de las tecnologías ya desarrolladas, hemos hecho un estudio comparativo entre tres vehículos ferroviarios que utilizan distintas soluciones de hibridación. Bi-modo Diesel/catenaria para los trenes Mitrac Hybrid, Diesel/baterías para las locomotoras RailPower, y catenaria/baterías para algunos tranvías Bombardier o Alstom que necesitan pasar unos lugares sin electrificación. Hemos llegado a la conclusión de que la alternativa 3 parece poco probable, y que como la alternativa 1 utiliza el mismo motor que la solución actual (consumo de combustible conocido), entonces hemos elegido proceder al dimensionamiento de la alternativa 2. Para hacer eso, hemos estudiado las necesidades de potencia motriz del vehículo mediante una curva de esfuerzo-velocidad, en la cual hemos visto la influencia de los diversos parámetros. Luego, hemos dimensionado energéticamente las diferentes fuentes energéticas: un grupo Diesel para proveer una potencia media al vehículo, un lote de baterías para suplir al grupo Diesel durante los picos de potencia, y un lote de súper-condensadores para preservar la vida de las baterías en caso de ciclos de alta frecuencia. Integrando las diferentes perdidas y una gestión frecuencial adecuada, hemos calculado las energías y las potencias útiles en función de la potencia instantánea de la misión P(t), lo que nos permite deducir los números mínimos de elementos a emplear para cada elemento. Como estos parámetros dependen de P(t) y de la potencia nominal del grupo Diesel PGEN, se podría optimizar nuestra solución minimizando la potencia del nuevo grupo Diesel pero teniendo en cuenta el límite de espacio disponible en la dresina. Al final, para que la solución satisfaga todos los requisitos impuestos por los criterios de éxito del proyecto (como por ejemplo el consumo de combustible, o el coste del sistema), hemos hecho unos estudios comparativos en función de la potencia del grupo Diesel que elegiríamos, a partir de los cuales se podrá verificar el cumplimiento. En efecto, como no tenemos el gráfico de la potencia P(t), no hemos podido sacar valores numéricos del dimensionamiento de nuestro sistema. Por último, hemos hecho una previsión temporal y económica del proyecto de industrialización, previsto por un año y un millón de euros, recordando unas reglas de legislación que se tendrían que cumplir

Estudio de condiciones técnicas de servicio para la implantación de vehículos ferroviarios híbridos para trabajos de mantenimiento de vías y catenarias

En el marco de la colaboración entre la UPC (Universistat Politècnica de Catalunya) y la TMB (Transport Metropolitans de Barcelona), este Proyecto Final de Carrera trata de las condiciones técnicas de servicio para la implantación de vehículos híbridos para el mantenimiento de vías y catenarias. Hemos estudiado los problemas planteados por el uso de máquinas térmicas de tipo Diesel dentro de los túneles del metro de Barcelona, que son la presencia de gases tóxicos de combustión, ruido, y calor en lugares de trabajo confinados. La degradación consecuente de la salud de los operarios también se ha podido admitir como un riesgo económico por la empresa TMB, además del posible incumplimiento de las normas medio-ambientales europeas. Para resolver este problema, la TMB tiene planteado cambiar sus dresinas térmicas por dresinas utilizando un medio de propulsión de tipo híbrido. Para elegir el mejor sistema de hibridación a partir de las tecnologías ya desarrolladas, hemos hecho un estudio comparativo entre tres vehículos ferroviarios que utilizan distintas soluciones de hibridación. Bi-modo Diesel/catenaria para los trenes Mitrac Hybrid, Diesel/baterías para las locomotoras RailPower, y catenaria/baterías para algunos tranvías Bombardier o Alstom que necesitan pasar unos lugares sin electrificación. Hemos llegado a la conclusión de que la alternativa 3 parece poco probable, y que como la alternativa 1 utiliza el mismo motor que la solución actual (consumo de combustible conocido), entonces hemos elegido proceder al dimensionamiento de la alternativa 2. Para hacer eso, hemos estudiado las necesidades de potencia motriz del vehículo mediante una curva de esfuerzo-velocidad, en la cual hemos visto la influencia de los diversos parámetros. Luego, hemos dimensionado energéticamente las diferentes fuentes energéticas: un grupo Diesel para proveer una potencia media al vehículo, un lote de baterías para suplir al grupo Diesel durante los picos de potencia, y un lote de súper-condensadores para preservar la vida de las baterías en caso de ciclos de alta frecuencia. Integrando las diferentes perdidas y una gestión frecuencial adecuada, hemos calculado las energías y las potencias útiles en función de la potencia instantánea de la misión P(t), lo que nos permite deducir los números mínimos de elementos a emplear para cada elemento. Como estos parámetros dependen de P(t) y de la potencia nominal del grupo Diesel PGEN, se podría optimizar nuestra solución minimizando la potencia del nuevo grupo Diesel pero teniendo en cuenta el límite de espacio disponible en la dresina. Al final, para que la solución satisfaga todos los requisitos impuestos por los criterios de éxito del proyecto (como por ejemplo el consumo de combustible, o el coste del sistema), hemos hecho unos estudios comparativos en función de la potencia del grupo Diesel que elegiríamos, a partir de los cuales se podrá verificar el cumplimiento. En efecto, como no tenemos el gráfico de la potencia P(t), no hemos podido sacar valores numéricos del dimensionamiento de nuestro sistema. Por último, hemos hecho una previsión temporal y económica del proyecto de industrialización, previsto por un año y un millón de euros, recordando unas reglas de legislación que se tendrían que cumplir

Cardiovascular and Coordination Training Differentially Improve Cognitive Performance and Neural Processing in Older Adults

Recent studies revealed a positive influence of physical activity on cognitive functioning in older adults. Studies that investigate the behavioral and neurophysiological effects of type and long term duration of physical training, however, are missing. We performed a 12-month longitudinal study to investigate the effects of cardiovascular and coordination training (control group: relaxation and stretching) on cognitive functions (executive control and perceptual speed) in older adults. We analyzed data of 44 participants aged 62–79 years. Participants were trained three times a week for 12 months. Their physical and cognitive performance was tested prior to training, and after 6 and 12 months. Changes in brain activation patterns were investigated using functional MRI. On the behavioral level, both experimental groups improved in executive functioning and perceptual speed but with differential effects on speed and accuracy. In line with the behavioral findings, neurophysiological results for executive control also revealed changes (increases and reductions) in brain activity for both interventions in frontal, parietal, and sensorimotor cortical areas. In contrast to the behavioral findings, neurophysiological changes were linear without indication of a plateau. In both intervention groups, prefrontal areas showed decreased activation after 6 and 12 months when performing an executive control task, as compared to the control group, indicating more efficient information processing. Furthermore, cardiovascular training was associated with an increased activation of the sensorimotor network, whereas coordination training was associated with increased activation in the visual–spatial network. Our data suggest that besides cardiovascular training also other types of physical activity improve cognition of older adults. The mechanisms, however, that underlie the performance changes seem to differ depending on the intervention

Iron Deficiency Anemia, Population Health and Frailty in a Modern Portuguese Skeletal Sample

INTRODUCTION Portugal underwent significant political, demographic and epidemiological transitions during the 20th century resulting in migration to urban areas with subsequent overcrowding and issues with water sanitation. This study investigates population health during these transitions and interprets results within a framework of recent history and present-day public health information. We investigate skeletal evidence for anemia (cribra orbitalia and porotic hyperostosis) as indicators of stress and frailty-i.e., whether the lesions contribute to susceptibility for disease or increased risk of death. METHODS The presence and severity of skeletal lesions were compared against known sex and cause of death data to investigate potential heterogeneity in frailty and the relationship between lesions and risk of dying over time. Additionally, we tested for the presence of selective mortality in our data (i.e., whether or not the sample is biased for individuals with higher frailty). Our sample derives from a large, documented, modern Portuguese collection from Lisbon and is the first study of its kind using a documented collection. The collection represents primarily middle-class individuals. RESULTS AND CONCLUSIONS: Analyses indicated that porotic hyperostosis became more common and severe over time, while cribra orbitalia severity increased over time. Neither process was linked to cause of death. However, there was a significant relationship to sex; males exhibited a higher prevalence and severity of lesions and increased mortality. A Gompertz function showed decreased survivorship in early life but increased survivorship over age 60. Using comorbidities of anemia, we were unable to detect selective mortality-i.e., in our sample, lesions do not represent a sign of poor health or increased frailty and are not significantly linked with a decreased mean age-at-death. However, lesion prevalence and severity do reflect the socioeconomic processes in urban Lisbon during the 1800s and 1900s and the possibility of water-borne parasites as the contributing factor for iron deficiency anemia