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1.
J Archaeol Method Theory ; 30(3): 757-804, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37600347

RESUMEN

Personal ornaments are widely viewed as indicators of social identity and personhood. Ornaments are ubiquitous from the Late Pleistocene to the Holocene, but they are most often found as isolated objects within archaeological assemblages without direct evidence on how they were displayed. This article presents a detailed record of the ornaments found in direct association with an Early Mesolithic buried female infant discovered in 2017 at the site of Arma Veirana (Liguria, Italy). It uses microscopic, 3D, and positional analyses of the ornaments as well as a preliminary perforation experiment to document how they were perforated, used, and what led to their deposit as part of the infant's grave goods. This study provides important information on the use of beads in the Early Mesolithic, in general, as well as the relationship between beads and young subadults, in particular. The results of the study suggest that the beads were worn by members of the infant's community for a considerable period before they were sewn onto a sling, possibly used to keep the infant close to the parents while allowing their mobility, as seen in some modern forager groups. The baby was then likely buried in this sling to avoid reusing the beads that had failed to protect her or simply to create a lasting connection between the deceased infant and her community. Supplementary Information: The online version contains supplementary material available at 10.1007/s10816-022-09573-7.

2.
J Geophys Res Biogeosci ; 127(8): e2022JG006876, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-36248721

RESUMEN

High-resolution space-based spectral imaging of the Earth's surface delivers critical information for monitoring changes in the Earth system as well as resource management and utilization. Orbiting spectrometers are built according to multiple design parameters, including ground sampling distance (GSD), spectral resolution, temporal resolution, and signal-to-noise ratio. Different applications drive divergent instrument designs, so optimization for wide-reaching missions is complex. The Surface Biology and Geology component of NASA's Earth System Observatory addresses science questions and meets applications needs across diverse fields, including terrestrial and aquatic ecosystems, natural disasters, and the cryosphere. The algorithms required to generate the geophysical variables from the observed spectral imagery each have their own inherent dependencies and sensitivities, and weighting these objectively is challenging. Here, we introduce intrinsic dimensionality (ID), a measure of information content, as an applications-agnostic, data-driven metric to quantify performance sensitivity to various design parameters. ID is computed through the analysis of the eigenvalues of the image covariance matrix, and can be thought of as the number of significant principal components. This metric is extremely powerful for quantifying the information content in high-dimensional data, such as spectrally resolved radiances and their changes over space and time. We find that the ID decreases for coarser GSD, decreased spectral resolution and range, less frequent acquisitions, and lower signal-to-noise levels. This decrease in information content has implications for all derived products. ID is simple to compute, providing a single quantitative standard to evaluate combinations of design parameters, irrespective of higher-level algorithms, products, applications, or disciplines.

3.
Folia Morphol (Warsz) ; 81(2): 520-525, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-33778941

RESUMEN

Understanding anatomical variations as well as normal anatomy of the muscles and tendons of the hand is vital for successful clinical evaluation and surgery. A number of extensor muscle and tendon variations have been reported in the literature, including duplication, triplication, and absence. We report a rare anatomical variation that includes bilateral absence of the extensor indicis (EI) muscles and bilateral duplication of the extensor digitorum (ED) tendon to the second digit in the forearm of an 83-year-old male cadaver during routine upper limbs dissection. In the present case, only three muscles were present in the deep compartment: extensor pollicis longus (EPL), extensor pollicis brevis (EPB), and abductor pollicis longus (APL) with bilateral absence of EI. The reported prevalence of bilateral absence of EI muscle and tendon ranges from 0.5% to 3.5%. The prevalence of an additional index tendon arising bilaterally from the ED muscle belly is 3.2% of the population. Extension of the index finger is governed by the actions of EI and ED. However, the four tendons of ED are linked to each other by juncturae tendinum, restricting independent extension of the digits in certain postures, e.g. when the hand is fisted. With fisted hand, EI controls extension of the index finger. Clinically, EI tendons are used for tendon reconstruction procedures to restore function to the hand and thumb after trauma or tendon rupture. This report highlights the importance of anticipating anatomical variations and conducting pre-operative evaluations to confirm the presence of EI when planning tendon transfer procedures.


Asunto(s)
Antebrazo , Tendones , Anciano de 80 o más Años , Variación Anatómica , Cadáver , Humanos , Masculino , Músculo Esquelético/anatomía & histología , Tendones/anatomía & histología , Pulgar/anatomía & histología , Pulgar/cirugía
4.
Ulster Med J ; 90(1): 7-9, 2021 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-33642626

RESUMEN

INTRODUCTION: Possibly In the UK there are currently over 26,000 patients admitted to hospital for acute pancreatitis per annum and the incidence is rising. 55% of patients consult the internet for information regarding their medical condition. As the number of people using the internet has increased 57% since 2006, it is increasingly important for medical professionals to direct patients to accurate online sources of information. This paper aims to evaluate the quality of information available online for acute pancreatitis. METHODS: The term 'acute pancreatitis' was searched using http://www.google.com, http://www.bing.com, and http://www.yahoo.com. The top 10 results of each of these websites were assessed using the University of Michigan consumer health website evaluation checklist. RESULTS: Of the 30 websites found, 4 were excluded from the evaluation. Within the 26 evaluated websites there was high variability in website quality. However, the authors would have used 18 of the websites again for the purpose of finding out information on acute pancreatitis. 15 websites had a named author of which 11 displayed their credentials. 8 of the websites had been updated within the last year. 10 websites displayed a bias or conflict of interest. Generally, the layout and design of websites was good, however 7 of the websites contained distracting graphics and 9 of the websites had no search facility. DISCUSSION: Doctors should give patients the information they want and need. With a high percentage of patients using the internet, medical professionals should recommend good quality websites to their patients. Engaging in this process could improve the consenting process as patients would be better informed. Good quality websites allows patients to explore conditions by themselves, with a re-consultation facilitating further discussion. Failure to engage in internet-based information risks patients making misinformed decisions due to bias and conflict of interest.


Asunto(s)
Información de Salud al Consumidor , Internet , Pancreatitis , Informática Aplicada a la Salud de los Consumidores , Humanos , Motor de Búsqueda
5.
BJOG ; 125(3): 374, 2018 02.
Artículo en Inglés | MEDLINE | ID: mdl-28636771
11.
J Synchrotron Radiat ; 21(Pt 6): 1262-8, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25343793

RESUMEN

Discovery of new materials drives the deployment of new technologies. Complex technological requirements demand precisely tailored material functionalities, and materials scientists are driven to search for these new materials in compositionally complex and often non-equilibrium spaces containing three, four or more elements. The phase behavior of these high-order composition spaces is mostly unknown and unexplored. High-throughput methods can offer strategies for efficiently searching complex and multi-dimensional material genomes for these much needed new materials and can also suggest a processing pathway for synthesizing them. However, high-throughput structural characterization is still relatively under-developed for rapid material discovery. Here, a synchrotron X-ray diffraction and fluorescence experiment for rapid measurement of both X-ray powder patterns and compositions for an array of samples in a material library is presented. The experiment is capable of measuring more than 5000 samples per day, as demonstrated by the acquisition of high-quality powder patterns in a bismuth-vanadium-iron oxide composition library. A detailed discussion of the scattering geometry and its ability to be tailored for different material systems is provided, with specific attention given to the characterization of fiber textured thin films. The described prototype facility is capable of meeting the structural characterization needs for the first generation of high-throughput material genomic searches.

12.
Integr Comp Biol ; 54(6): 1148-58, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25237138

RESUMEN

Most primates are able to move with equal facility on the ground and in trees, but most use the same quadrupedal gaits in both environments. A few specialized primates, however, use a suspensory or leaping mode of locomotion when in the trees but a bipedal gait while on the ground. This is a rare behavioral pattern among mammals, and the extent to which the bipedal gaits of these primates converge and are constrained by the anatomical and neurological adaptations associated with arboreal locomotion is poorly understood. Sifakas (Propithecus), primates living only in Madagascar, are highly committed vertical clingers and leapers that also spend a substantial amount of time on the ground. When moving terrestrially sifakas use a unique bipedal galloping gait seen in no other mammals. Little research has examined the mechanics of these gaits, and most of that research has been restricted to controlled captive conditions. The energetic costs associated with leaping and bipedal galloping are unknown. This study begins to fill that gap using triaxial accelerometry to characterize and compare the dynamics of sifakas' leaping and bipedal galloping behavior. As this is a relatively novel approach, the first goal of this article is to explore the feasibility of collecting such data on free-roaming animals and attempt to automate the identification of leaping and bipedal behavior within the output. The second goal is to compare the overall accelerations of the body and to use that as an approximation of aspects of energetic costs during leaping and bipedalism. To achieve this, a lightweight accelerometer was mounted on freely moving sifakas. The resulting acceleration profiles were processed, and sequences of leaps (bouts) were automatically extracted from the waveforms with 85% accuracy. Both vector dynamic body acceleration and overall dynamic body acceleration (ODBA) were used to characterize locomotor patterns and energy expenditure during leaping and bipedalism. The unique kinematics of the gait of sifakas, and the mechanics of bouts involving a string of successive leaps or gallops, appear to minimize redirections of the center of mass as well as the number of acceleration peaks and ODBAs. These results suggest that bipedal galloping is not only a reflection of the unique anatomical configuration of a leaping primate, but it may also provide a musculoskeletal and an energetic advantage to sifakas. In that sense, bipedal galloping represents an advantageous way for sifakas to move when transitioning from arboreal leaping to terrestrial locomotion.


Asunto(s)
Aceleración , Adaptación Biológica/fisiología , Metabolismo Energético/fisiología , Marcha/fisiología , Locomoción/fisiología , Strepsirhini/fisiología , Árboles , Acelerometría/métodos , Animales , Animales de Zoológico , Fenómenos Biomecánicos
13.
Osteoarthritis Cartilage ; 22(6): 747-55, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24752039

RESUMEN

OBJECTIVE: Pathological gaits have been shown to limit transfer between potential (PE) and kinetic (KE) energy during walking, which can increase locomotor costs. The purpose of this study was to examine whether energy exchange would be limited in people with knee osteoarthritis (OA). METHODS: Ground reaction forces during walking were collected from 93 subjects with symptomatic knee OA (self-selected and fast speeds) and 13 healthy controls (self-selected speed) and used to calculate their center of mass (COM) movements, PE and KE relationships, and energy recovery during a stride. Correlations and linear regressions examined the impact of energy fluctuation phase and amplitude, walking velocity, body mass, self-reported pain, and radiographic severity on recovery. Paired t-tests were run to compare energy recovery between cohorts. RESULTS: Symptomatic knee OA subjects displayed lower energetic recovery during self-selected walking speeds than healthy controls (P = 0.0018). PE and KE phase relationships explained the majority (66%) of variance in recovery. Recovery had a complex relationship with velocity and its change across speeds was significantly influenced by the self-selected walking speed of each subject. Neither radiographic OA scores nor subject self-reported measures demonstrated any relationship with energy recovery. CONCLUSIONS: Knee OA reduces effective exchange of PE and KE, potentially increasing the muscular work required to control movements of the COM. Gait retraining may return subjects to more normal patterns of energy exchange and allow them to reduce fatigue.


Asunto(s)
Aceleración , Metabolismo Energético/fisiología , Limitación de la Movilidad , Osteoartritis de la Rodilla/diagnóstico , Caminata/fisiología , Anciano , Antropometría , Fenómenos Biomecánicos , Índice de Masa Corporal , Estudios de Casos y Controles , Evaluación de la Discapacidad , Femenino , Marcha , Humanos , Modelos Lineales , Masculino , Persona de Mediana Edad , Osteoartritis de la Rodilla/rehabilitación , Dimensión del Dolor , Pronóstico , Valores de Referencia , Índice de Severidad de la Enfermedad , Factores de Tiempo
14.
Proc Natl Acad Sci U S A ; 108(17): 6975-80, 2011 Apr 26.
Artículo en Inglés | MEDLINE | ID: mdl-21474780

RESUMEN

Biological membranes are complex, self-organized structures that define boundaries and compartmentalize space in living matter. Composed of a wide variety of lipid and protein molecules, these responsive surfaces mediate transmembrane signaling and material transport within the cell and with its environment. It is well known that lipid membrane properties change as a function of composition and phase state, and that protein-lipid interactions can induce changes in the membrane's properties and biochemical response. Here, molecular level changes in lipid organization induced by multivalent toxin binding were investigated using grazing incidence X-ray diffraction. Structural changes to lipid monolayers at the air-water interface and bilayers at the solid-water interface were studied before and after specific binding of cholera toxin to membrane embedded receptors. At biologically relevant surface pressures, protein binding perturbed lipid packing within monolayers and bilayers resulting in topological defects and the emergence of a new orientationally textured lipid phase. In bilayers this altered lipid order was transmitted from the receptor laden exterior membrane leaflet to the inner leaflet, representing a potential mechanism for lipid mediated outside-in signaling by multivalent protein binding. It is further hypothesized that cell-surface micro-domains exhibiting this type of lipid order may serve as nucleation sites for vesicle formation in clathrin independent endocytosis of cholera toxin.


Asunto(s)
Membrana Celular/química , Lípidos de la Membrana/química , Proteínas de la Membrana/química , Membranas Artificiales , Modelos Biológicos , Membrana Celular/metabolismo , Toxina del Cólera/química , Toxina del Cólera/metabolismo , Endocitosis/fisiología , Lípidos de la Membrana/metabolismo , Proteínas de la Membrana/metabolismo , Transducción de Señal/fisiología
15.
Phys Rev Lett ; 102(23): 238101, 2009 Jun 12.
Artículo en Inglés | MEDLINE | ID: mdl-19658974

RESUMEN

The structure of single supported dipalmitoyl-phosphatidylcholine bilayers prepared by vesicle fusion or Langmuir-Blodgett-Schaeffer (LBS) deposition techniques was characterized by x-ray reflectivity and grazing incidence diffraction in bulk water. LBS bilayers display symmetric leaflets similar to monolayer structures, while vesicle fusion yields more inhomogeneous bilayers. Diffraction establishes that lipids are always coupled across the bilayer even when leaflets are deposited independently and suggests the existence of orientational texture.


Asunto(s)
Membrana Dobles de Lípidos/química , 1,2-Dipalmitoilfosfatidilcolina/química , Modelos Moleculares , Agua/química , Difracción de Rayos X
16.
Biophys J ; 95(7): 3278-86, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18599631

RESUMEN

Using synchrotron grazing-incidence x-ray diffraction (GIXD) and reflectivity, the in-plane and out-of-plane structures of mixed-ganglioside GT(1b)-phospholipid monolayers were investigated at the air-liquid interface and compared with monolayers of the pure components. The receptor GT(1b) is involved in the binding of lectins and toxins, including botulinum neurotoxin, to cell membranes. Monolayers composed of 20 mol % ganglioside GT(1b), the phospholipid dipalmitoyl phosphatidylethanolamine (DPPE), and the phospholipid dipalmitoyl phosphatidylcholine (DPPC) were studied in the gel phase at 23 degrees C and at surface pressures of 20 and 40 mN/m, and at pH 7.4 and 5. Under these conditions, the two components did not phase-separate, and no evidence of domain formation was observed. The x-ray scattering measurements revealed that GT(1b) was intercalated within the host DPPE/DPPC monolayers, and slightly expanded DPPE but condensed the DPPC matrix. The oligosaccharide headgroups extended normally from the monolayer surfaces into the subphase. This study demonstrated that these monolayers can serve as platforms for investigating toxin membrane binding and penetration.


Asunto(s)
1,2-Dipalmitoilfosfatidilcolina/metabolismo , Membrana Celular/química , Membrana Celular/metabolismo , Gangliósidos/metabolismo , Fosfatidiletanolaminas/metabolismo , Difracción de Rayos X , Conformación de Carbohidratos , Gangliósidos/química , Membrana Dobles de Lípidos/metabolismo , Presión , Propiedades de Superficie
17.
Biophys J ; 95(2): 629-40, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18359802

RESUMEN

Cholera toxin is a highly efficient biotoxin, which is frequently used as a tool to investigate protein-membrane interactions and as a reporter for membrane rafts. Cholera toxin binds selectively to gangliosides with highest affinity to GM(1). However, the mechanism by which cholera toxin crosses the membrane remains unresolved. Using x-ray reflectivity and grazing incidence diffraction, we have been able to monitor the binding and penetration of cholera toxin into a model lipid monolayer containing the receptor GM(1) at the air-water interface. Very high toxin coverage was obtained allowing precise measurements of how toxin binding alters lipid packing. Grazing incidence x-ray diffraction revealed the coexistence of two monolayer phases after toxin binding. The first was identical to the monolayer before toxin binding. In regions where toxin was bound, a second membrane phase exhibited a decrease in order as evidenced by a larger area per molecule and tilt angle with concomitant thinning of the monolayer. These results demonstrate that cholera toxin binding induces the formation of structurally distinct, less ordered domains in gel phases. Furthermore, the largest decrease in lateral order to the monolayer occurred at low pH, supporting a low endosomal pH in the infection pathway. Surprisingly, at pH = 8 toxin penetration by the binding portion of the toxin, the B(5) pentamer, was also observed.


Asunto(s)
Toxina del Cólera/química , Membrana Dobles de Lípidos/química , Fluidez de la Membrana , Difracción de Rayos X , Conformación Molecular , Transición de Fase
18.
Biophys J ; 95(2): 641-7, 2008 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18359801

RESUMEN

The structure of cholera toxin (CTAB(5)) bound to its putative ganglioside receptor, galactosyl-N-acetylgalactosaminyl (N-acetyl-neuraminyl) galactosylglucosylceramide (GM(1)), in a lipid monolayer at the air-water interface has been studied utilizing grazing incidence x-ray diffraction. Cholera toxin is one of very few proteins to be crystallized in two dimensions and characterized in a fully hydrated state. The observed grazing incidence x-ray diffraction Bragg peaks indicated cholera toxin was ordered in a hexagonal lattice and the order extended 600-800 A. The pentameric binding portion of cholera toxin (CTB(5)) improved in-plane ordering over the full toxin (CTAB(5)) especially at low pH. Disulfide bond reduction (activation of the full toxin) also increased the protein layer ordering. These findings are consistent with A-subunit flexibility and motion, which cause packing inefficiencies and greater disorder of the protein layer. Corroborative out-of-plane diffraction (Bragg rod) analysis indicated that the scattering units in the cholera layer with CTAB(5) shortened after disulfide bond reduction of the A subunit. These studies, together with Part I results, revealed key changes in the structure of the cholera toxin-lipid system under different pH conditions.


Asunto(s)
Toxina del Cólera/química , Galactosilceramidas/química , Membrana Dobles de Lípidos/química , Fluidez de la Membrana , Difracción de Rayos X , Conformación Molecular , Transición de Fase
19.
Phys Rev Lett ; 100(5): 058103, 2008 Feb 08.
Artículo en Inglés | MEDLINE | ID: mdl-18352436

RESUMEN

We report the first grazing incidence x-ray diffraction measurements of a single phospholipid bilayer at the solid-liquid interface. Our grazing incidence x-ray diffraction and reflectivity measurements reveal that the lateral ordering in a supported DPPE (1, 2-Dipalmitoyl-sn-Glycero-3-Phosphoethanolamine) bilayer is significantly less than that of an equivalent monolayer at the air-liquid interface. Our findings also indicate that the leaflets of the bilayer are uncoupled in contrast to the scattering from free standing phosphatidylcholine bilayers. The methodology presented can be readily implemented to study more complicated biomembranes and their interaction with proteins.


Asunto(s)
Membranas Artificiales , Fosfolípidos/química , Membrana Dobles de Lípidos , Fosfatidiletanolaminas/química , Difracción de Rayos X
20.
J R Soc Interface ; 5(21): 465-75, 2008 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-17974531

RESUMEN

This study quantifies the shape change in elephant manus and pes anatomy with increasing body mass, using computed tomographic scanning. Most manus and pes bones, and manus tendons, maintain their shape, or become more gracile, through ontogeny. Contrary to this, tendons of the pes become significantly more robust, suggesting functional adaptation to increasingly high loads. Ankle tendon cross-sectional area (CSA) scales the highest in the long digital extensor, proportional to body mass(1.08+/-0.21), significantly greater than the highest-scaling wrist tendon (extensor carpi ulnaris, body mass(0.69+/-0.09)). These patterns of shape change relate to the marked anatomical differences between the pillar-like manus and tripod-like pes, consistent with differences in fore- and hindlimb locomotor function. The cartilaginous predigits (prepollux and prehallux) of the manus and pes also become relatively more robust through ontogeny, and their pattern of shape change does not resemble that seen in any of the 10 metacarpals and metatarsals. Their CSAs scale above isometry proportional to body mass(0.73+/-0.09) and body mass(0.82+/-0.07) respectively. We infer a supportive function for these structures, preventing collapse of the foot pad during locomotion.


Asunto(s)
Desarrollo Óseo/fisiología , Elefantes/anatomía & histología , Elefantes/crecimiento & desarrollo , Pie/anatomía & histología , Pie/crecimiento & desarrollo , Animales , Tamaño Corporal
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