Hasil untuk "Physical anthropology. Somatology"

Takashi Yamashita, Yulong Ren, Yuta Kosuge et al.

Abstract Purpose There are no previous reports investigating the effects of different set numbers in low-intensity resistance exercise with slow movement and tonic force generation (LST) on muscle fatigue using surface electromyography (sEMG). This study aimed to examine muscle fatigue induced by one set and three sets of LST and to compare the impact of set differences on muscle activity by comparing LST with traditional high-intensity resistance exercise (TRAD). Methods Twenty-three healthy male students participated in this study. After 1RM testing in each leg was completed, participants were randomly assigned to either a group performing one set of exercises (n = 10) or a group performing three sets (n = 13). Each participant performed the LST protocol (50% 1RM) and the TRAD protocol (80% 1RM) with single leg extension until failure. The LST protocol consisted of a 3-s concentric, a 1-s isometric, and a 3-s eccentric phase. In contrast, the TRAD protocol consisted of a 1-s concentric, a 1-s eccentric, and a 1-s rest phase. For the three-set group, a 2-min rest interval was provided between sets. The outcome measures included maximal isometric knee extension torque (MVC) before and after exercise, root mean square (RMS), and mean power frequency (MPF) values recorded during the exercises. Results No significant differences in MVC were observed between the type of exercise or the number of sets. Similarly, no significant differences in the RMS during the exercise were observed across exercise types or number of sets. On the other hand, with the significant interaction of MPF (p = 0.001, η p 2  = 0.399), there was a significant difference in three sets of LST compared to one set of LST (p = 0.012, d = 1.16) and three sets of TRAD (p < 0.001, d = 0.93). Conclusion Our findings suggest that performing three sets of LST induces significant muscle fatigue. Therefore, we speculate that performing three sets of LST may lead to the accumulation of metabolic stress and thereby cause muscle fatigue.

J. M. Alarcón, E. Lope-Oter, Y. Cano

There is an increasing interest in the community for the Neutron Stars and what we can learn from them. In this review we show how chiral effective field theory, combined with many-body methods, can provide important results that connect Neutron Star properties at zero temperature to nuclear physics and allows to use these compact objects as laboratories of new physics.

Chien-Hsiang Lin, Siao-Man Wu, Chia-Yen Lin et al.

Abstract Understanding the diversity of deep-sea fish fauna based on otoliths in the tropical and subtropical West Pacific has been limited, creating a significant knowledge gap regarding regional and temporal variations in deep-sea fish fauna. To address this gap, we collected a total of 122 bulk sediment samples from the Lower Pliocene Gutingkeng Formation in southwestern Taiwan to reconstruct the otolith-based fish fauna. Using planktonic foraminiferal biostratigraphy, we determined the age of the samples to be 5.6 to 3.1 Ma. A total of 8314 otoliths were assigned to 64 different taxa from 33 families, including the discovery of one new genus, Gutingichthys gen. nov., and three new species: Benthosema duanformis sp. nov., Benthosema parafibulatum sp. nov., and Gutingichthys changi sp. nov. Comparisons with other regional otolith-based assemblages highlighted the exceptional diversity of our collection, making it the most diverse fossil fish fauna reported from Taiwan to date. Otolith diversity analysis revealed very few taxa were dominant in the assemblage, particularly the mesopelagic Myctophidae, with a wide variety of minor taxa. The co-occurrence of shallow-water elements suggests episodic storm events as a potential source. The predominance of deep-sea and oceanic fishes indicated an outer-shelf to upper slope environment, resembling the modern outer-shelf and upper slope fish fauna in the region. Our findings suggest an early establishment and persistent presence of the mesopelagic fish community since the Early Pliocene. Further investigations of the Upper Miocene and Pleistocene sections of the Gutingkeng Formation would provide valuable insights into the evolution of deep-sea fish fauna in the area. ZooBank LSID: urn:lsid:zoobank.org:pub:7A336FC7-0D9A-4D17-B212-0B51427945DD.

Ruth Mace

Maxwell X. Cai, Kin Long Kelvin Lee

In physics, density $ρ(\cdot)$ is a fundamentally important scalar function to model, since it describes a scalar field or a probability density function that governs a physical process. Modeling $ρ(\cdot)$ typically scales poorly with parameter space, however, and quickly becomes prohibitively difficult and computationally expensive. One promising avenue to bypass this is to leverage the capabilities of denoising diffusion models often used in high-fidelity image generation to parameterize $ρ(\cdot)$ from existing scientific data, from which new samples can be trivially sampled from. In this paper, we propose $ρ$-Diffusion, an implementation of denoising diffusion probabilistic models for multidimensional density estimation in physics, which is currently in active development and, from our results, performs well on physically motivated 2D and 3D density functions. Moreover, we propose a novel hashing technique that allows $ρ$-Diffusion to be conditioned by arbitrary amounts of physical parameters of interest.

Michael Vignal, Gayle Geschwind, Benjamin Pollard et al.

Measurement uncertainty is a critical feature of experimental research in the physical sciences, and the concepts and practices surrounding measurement uncertainty are important components of physics lab courses. However, there has not been a broadly applicable, research-based assessment tool that allows physics instructors to easily measure students' knowledge of measurement uncertainty concepts and practices. To address this need, we employed Evidence-Centered Design to create the Survey of Physics Reasoning on Uncertainty Concepts in Experiments (SPRUCE). SPRUCE is a pre-post assessment instrument intended for use in introductory (first- and second-year) physics lab courses to help instructors and researchers identify student strengths and challenges with measurement uncertainty. In this paper, we discuss the development of SPRUCE's assessment items guided by Evidence-Centered Design, focusing on how instructors' and researchers' assessment priorities were incorporated into the assessment items and how students' reasoning from pilot testing informed decisions around item answer options. We also present an example of some of the feedback an instructor would receive after implementing SPRUCE in a pre-post fashion, along with a brief discussion of how that feedback could be interpreted and acted upon.

DAISUKE AIBA

Mature modifications, ontogeny, and dimorphism of the small-sized tetragonitid ammonoid Tetragonites minimus were investigated in 43 specimens from the Santonian, Upper Cretaceous of the northwestern area of Hokkaido, Japan. Four types of mature modifications were recognised in the shell diameters of 11–13 mm and 16–19 mm, and two differently sized adults were regarded as microconchs and macroconchs respectively. The conch forms of dimorphic pairs were similar in juvenile but differ in the later stage. The supplementary analysis showed that the remarkable adult size differences in antidimorphs continued at least in the Turonian–Santonian. The mature size and size difference between dimorphic pairs decreased chronologically. 36 specimens (84% of examined specimens) were mature, and immature shells were rare in the Santonian. Most of the shells were remarkably well preserved, indicating that T. minimus assemblage fossilised quickly near their original habitat without long-distance post-mortem transport. Hence the bias in the fossil occurrence of adult T. minimus is unlikely to be due to taphonomy such as the bias of fossilisation potential and floatability in the bottom currents. Tetragonites minimus might have been changing their habitats during their life cycle.

Nhat M. Nguyen, Hieu T. Tran, Minh V. Duong et al.

We present a differentiable greenhouse simulation model based on physical processes whose parameters can be obtained by training from real data. The physics-based simulation model is fully interpretable and is able to do state prediction for both climate and crop dynamics in the greenhouse over very a long time horizon. The model works by constructing a system of linear differential equations and solving them to obtain the next state. We propose a procedure to solve the differential equations, handle the problem of missing unobservable states in the data, and train the model efficiently. Our experiment shows the procedure is effective. The model improves significantly after training and can simulate a greenhouse that grows cucumbers accurately.

Daniel Kelshaw, Luca Magri

Measurements on dynamical systems, experimental or otherwise, are often subjected to inaccuracies capable of introducing corruption; removal of which is a problem of fundamental importance in the physical sciences. In this work we propose physics-informed convolutional neural networks for stationary corruption removal, providing the means to extract physical solutions from data, given access to partial ground-truth observations at collocation points. We showcase the methodology for 2D incompressible Navier-Stokes equations in the chaotic-turbulent flow regime, demonstrating robustness to modality and magnitude of corruption.

Imelda M. Hausmann, Alexander Nützel, Vanessa Julie Roden et al.

Two marine invertebrate fossil assemblages from the Late Triassic Cassian Formation (Dolomites, northern Italy) were examined to assess their diversity and palaeoecology. Surface and bulk samples from the localities Misurina Landslide and Lago Antorno were taken and analysed separately. Both benthic assemblages are relatively similar in taxonomic composition. Gastropods form the most abundant and diverse group, followed by bivalves. Disarticulated echinoderm ossicles are also common in the bulk sample from Misurina Landslide, but they are rare at Lago Antorno. The Misurina Landslide outcrop has yielded two echinoderm Palaeozoic holdovers, the ophiocistioid Linguaserra triassica and plates of putative proterocidarids, supporting the earlier hypothesis that such basins acted as refugia. The gastropod species Coelostylina conica, Prostylifer paludinaris, and Ampezzopleura hybridopsis are characteristic elements of both assemblages. The gastropod Jurilda elongata, however, is the most abundant species at Misurina Landslide, whereas juveniles of the gastropod species Dentineritaria neritina dominate the assemblage from Lago Antorno. Newly described gastropod taxa are Angulatella bizzarinii Nützel and Hausmann gen. et sp. nov., Bandellina compacta Nützel and Hausmann sp. nov., and Ampezzogyra angulata Nützel and Hausmann sp. nov. Fifty-seven invertebrate species were found in the bulk sample from Misurina Landslide and 26 species were recovered from the bulk sample from Lago Antorno. However, sample size from Lago Antorno was much smaller than that from Misurina. Diversity indices (Shannon, Simpson, Berger-Parker) show similar moderate diversities in both assemblages. Rarefaction curves and rank-abundance distributions also point to very similar diversities and ecological structures of the fossil assemblages. Both assemblages are autochthonous or parautochthonous, stemming from basinal, soft-bottom habitats. Their taxonomic composition differs significantly from that of other faunas known from the Cassian Formation. The tropical marine Cassian palaeoecosystem was highly complex and its diversity is still far from being fully explored.

Antonio Costantini

We present the results of the physics reach of a multi-TeV muon collider for popular models of physics beyond the Standard Model. We include also details about a model predicting the scalar dark matter in the spectrum. Finally we present some preliminary results about the Effective Vector Approximation and its implementation in the Monte Carlo generator {\sc MadGraph5\_aMC@NLO}.

Nandor Verba, Elena Gaura, Stephen McArthur et al.

We have designed a two-stage, 10-step process to give organisations a method to analyse small local energy systems (SLES) projects based on their Cyber Physical System components in order to develop future-proof energy systems. SLES are often developed for a specific range of use cases and functions, and these match the specific requirements and needs of the community, location or site under consideration. During the design and commissioning, new and specific cyber physical architectures are developed. These are the control and data systems that are needed to bridge the gap between the physical assets, the captured data and the control signals. Often, the cyber physical architecture and infrastructure is focused on functionality and the delivery of the specific applications. But we find that technologies and approaches have arisen from other fields that, if used within SLES, could support the flexibility, scalability and reusability vital to their success. As these can improve the operational data systems then they can also be used to enhance predictive functions If used and deployed effectively, these new approaches can offer longer term improvements in the use and effectiveness of SLES, while allowing the concepts and designs to be capitalised upon through wider roll-out and the offering of commercial services or products.

Jessica R. Hoehn, H. J. Lewandowski

Writing is an integral part of the process of science. In the undergraduate physics curriculum, the most common place that students engage with scientific writing is in lab classes, typically through lab notebooks, reports, and proposals. There has not been much research on why and how we include writing in physics lab classes, and instructors may incorporate writing for a variety of reasons. Through a broader study of multiweek projects in advanced lab classes, we have developed a framework for thinking about and understanding the role of writing in lab classes. This framework defines and describes the breadth of goals for incorporating writing in lab classes, and is a tool we can use to begin to understand why, and subsequently how, we teach scientific writing in physics.

Tor Ole B. Odden, Elise Lockwood, Marcos D. Caballero

Computation is becoming an increasingly important part of physics education. However, there are currently few theories of learning that can be used to help explain and predict the unique challenges and affordances associated with computation in physics. In this study, we adapt the existing theory of computational literacy, which posits that computational learning can be divided into material, cognitive, and social aspects, to the context of undergraduate physics. Based on an exploratory study of undergraduate physics computational literacy, using a newly-developed teaching tool known as a computational essay, we have identified a variety of student practices, knowledge, and beliefs across these three aspects of computational literacy. We illustrate these categories with data collected from students who engaged in an initial implementation of computational essays in an introductory electricity and magnetism class. We conclude by arguing that this framework can be used to theoretically diagnose student difficulties with computation, distinguish educational approaches that focus on material vs. cognitive aspects of computational literacy, and highlight the benefits and limitations of open-ended projects like computational essays to student learning.

Francois Lanusse, Peter Melchior, Fred Moolekamp

We present a Bayesian machine learning architecture that combines a physically motivated parametrization and an analytic error model for the likelihood with a deep generative model providing a powerful data-driven prior for complex signals. This combination yields an interpretable and differentiable generative model, allows the incorporation of prior knowledge, and can be utilized for observations with different data quality without having to retrain the deep network. We demonstrate our approach with an example of astronomical source separation in current imaging data, yielding a physical and interpretable model of astronomical scenes.

Luciano Maiani, Luisa Bonolis

Personal recollections on theoretical particle physics in the years when the Standard Theory was formed. In the background, the remarkable development of Italian theoretical physics in the second part of the last century, with great personalities like Bruno Touschek, Raoul Gatto, Nicola Cabibbo and their schools.

María Eugenia Luna, Fabián A. Quintero, Maria F. Cesani et al.

El objetivo fue analizar en animales con retardo prenatal de crecimiento (RPC) el efecto de la subnutrición proteico-calórica lactacional y postlactacional sobre la morfología craneofacial, particularizando en el crecimiento de los componentes funcionales neural y facial. Ratas Wistar fueron divididas en los grupos: Control, RPC (inducido por ligamiento parcial de ambas arterias uterinas el día 15 de gestación) y Sham-operado (con igual técnica quirúrgica que RPC aunque sin ligamiento de las arterias). A su vez, el grupo RPC se dividió en: (a) crías lactantes de madres con nutrición normal y a partir del destete alimentadas ad-libitum y (b) crías lactantes de madres con restricción alimentaria del 25% y a partir del destete alimentadas con el 50% de lo consumido por un animal control. Se tomaron radiografías a las edades 1, 21, 42, 63 y 84 y se midieron longitud, ancho y altura de los componentes neural y facial. Se calcularon los índices volumétricos neural y facial y morfométrico neurofacial. Se aplicaron ANOVA y pruebas post-hoc y se calcularon diferencias porcentuales entre medias. Los resultados permitieron concluir que el estrés primario ocurrido durante la vida intrauterina resulta crítico en lo inmediato y en la vida postnatal, ya que aun mediando normonutrición postnatal el retardo de crecimiento perdura. Además, cuando al estrés prenatal le continúa restricción nutricional postnatal los efectos adversos son aditivos provocando retardo del crecimiento aún mayor. Finalmente, mientras que el componente neural es más resistente a las deficiencias nutricionales, el facial presenta mayor plasticidad, hecho que se evidencia en cambios de forma. Palabras clave: crecimiento craneofacial; desnutrición pre y postnatal; craneometría funcional    The aim of the study was to analyze the effect of protein-calorie malnutrition during lactation and post-lactation on craniofacial morphology in intrauterine growth-retarded (IUGR) animals, particularly in the neural and facial functional components. Wistar rats were divided into the following groups: Control, IUGR (induced by partial bending of both uterine vessels at day 15 of gestation), and sham-operated (with the same surgical technique as IUGR, but without vessel bending). The IUGR group was further divided into (a) nursing pups of mothers with normal nutrition and fed ad-libitum at weaning, and (b) nursing pups of mothers with 25% food restriction and fed with 50% of the food ingested by controls at weaning. Radiographs were taken at 1, 21, 42, 63, and 84 days. Neural and facial length, width and height were measured, and neural and facial volumetric and morphometric indices were calculated. ANOVA and post-hoc tests were applied, and percentage differences between means were determined. Results showed that intrauterine stress is critical during early and postnatal life, since even when postnatal nutrition is normal, growth retardation persists. Furthermore, when prenatal stress is followed by postnatal nutritional restriction, adverse effects are additive and cause even greater growth retardation. Finally, while the neural component is more resistant to nutritional deficiencies, the facial component has greater plasticity, as reflected in the shape changes observed. Key words: craniofacial growth; prenatal and postnatal undernutrition; functional craniometre

P. J. E. Peebles

The experimental study of gravity became much more active in the late 1950s, a change pronounced enough be termed the birth, or naissance, of experimental gravity physics. I present a review of developments in this subject since 1915, through the broad range of new approaches that commenced in the late 1950s, and up to the transition of experimental gravity physics to what might be termed a normal and accepted part of physical science in the late 1960s. This review shows the importance of advances in technology, here as in all branches of natural science. The role of contingency is illustrated by Robert Dicke's decision in the mid-1950s to change directions in mid-career, to lead a research group dedicated to the experimental study of gravity. The review also shows the power of nonempirical evidence. Some in the 1950s felt that general relativity theory is so logically sound as to be scarcely worth the testing. But Dicke and others argued that a poorly tested theory is only that, and that other nonempirical arguments, based on Mach's Principle and Dirac's Large Numbers hypothesis, suggested it would be worth looking for a better theory of gravity. I conclude by offering lessons from this history, some peculiar to the study of gravity physics during the naissance, some of more general relevance. The central lesson, which is familiar but not always well advertised, is that physical theories can be empirically established, sometimes with surprising results.

José L. Lanata

Como investigadores nos vemos enfrentados a una serie de dilemas que, si bien se relacionan con nuestro tema de estudio, nos colocan frente a situaciones conflictivas. Por un lado, el rápido desarrollo tecnológico que nos permite obtener información cada vez más específica y novedosa, a la vez que la difusión de nuestros resultados es más fácilmente accesible por colegas en diferentes partes del mundo a través de la digitalización y la informática. Así toda investigación, propia o foránea, está al alcance de un “click de mouse”. Por otro, la concientización de que la muestra que trabajamos hoy es pasible de transformarse mañana en una nueva fuente de datos, no sólo nos alerta para su adecuado manejo si no también para su correcta conservación a fin de preservarla convenientemente para que en el futuro se puedan obtener nuevos datos. Esto es también un reto para nosotros como investigadores, aún cuando puedan llegar a contradecir nuestros resultados. Además, el hecho de la existencia de derechos -que a primera instancia parecerían contrapuestos- entre las diferentes partes que intervienen directa o indirectamente en una investigación antropológica, nos enfrenta a desafíos que exceden la meta científica. A esto se le suma la –por el momento- casi ausencia de protocolos que establezcan las pertinentes relaciones y responsabilidades entre nosotros -con derechos como investigadores- y las instituciones a las que pertenecemos. Así no encontramos en una encrucijada en la que se hace imperioso compatibilizar y ecualizar los derechos de las diferentes partes, sin descontar nuestra responsabilidad académica y científica a futuro.

Rosendo Pascual

El presente trabajo presenta una reseña de la historia de la Paleontología de Vertebrados y la investigación actual sobre vertebrados fósiles en la Argentina, en el marco del 25o aniversario desde la fundación de la Asociación Paleontológica Argentina.