75 research outputs found
Conformal gravity: light deflection revisited and the galactic rotation curve failure
We show how Conformal Gravity (CG) has to satisfy a fine-tuning condition to
describe the rotation curves of disk galaxies without the aid of dark matter.
Interpreting CG as a gauge natural theory yields conservation laws and their
associated superpotentials without ambiguities. We consider the light
deflection of a point-like lens and impose that the two Schwarzschild-like
metrics with and without the lens are identical at infinite distances from the
lens. The energy conservation law implies that the parameter in the
linear term of the metric has to vanish, otherwise the two metrics are
physically inaccessible from each other. This linear term is responsible to
mimic the role of dark matter in disk galaxies and gravitational lensing
systems. Our analysis shows that removing the need of dark matter with CG thus
relies on a fine-tuning condition on . We also illustrate why the
results of previous investigations of gravitational lensing in CG largely
disagree. These discrepancies derive from the erroneous use of the deflection
angle definition adopted in General Relativity, where the vacuum solution is
asymptotically flat, unlike CG. In addition, the lens mass is identified with
various combinations of the metric parameters. However, these identifications
are arbitrary, because the mass is not a conformally invariant quantity, unlike
the conserved charge associated to the energy conservation law. Based on this
conservation law and by removing the fine-tuning condition on , i.e. by
setting , the energy difference between the metric with the
point-like lens and the metric without it defines a conformally invariant
quantity that can in principle be used for (1) a proper derivation of light
deflection in CG, and (2) the identification of the lens mass with a function
of the parameters and of the Schwarzschild-like metric.Comment: 16 pages, 1 figure. Revised version according to the referees
comments. The results reported in the original version remain unchange
In memoriam two distinguished participants of the Bregenz Symmetries in Science Symposia: Marcos Moshinsky and Yurii Fedorovich Smirnov
Some particular facets of the numerous works by Marcos Moshinsky and Yurii
Fedorovich Smirnov are presented in these notes. The accent is put on some of
the common interests of Yurii and Marcos in physics, theoretical chemistry, and
mathematical physics. These notes also contain some more personal memories of
Yurii Smirnov.Comment: Submitted for publication in Journal of Physics: Conference Serie
On Clinical Agreement on the Visibility and Extent of Anatomical Layers in Digital Gonio Photographs
Purpose: To quantitatively evaluate the inter-annotator variability of clinicians tracing the contours of anatomical layers of the iridocorneal angle on digital gonio photographs, thus providing a baseline for the validation of automated analysis algorithms. Methods: Using a software annotation tool on a common set of 20 images, five experienced ophthalmologists highlighted the contours of five anatomical layers of interest: iris root (IR), ciliary body band (CBB), scleral spur (SS), trabecular meshwork (TM), and cornea (C). Inter-annotator variability was assessed by (1) comparing the number of times ophthalmologists delineated each layer in the dataset; (2) quantifying how the consensus area for each layer (i.e., the intersection area of observers\u2019delineations) varied with the consensus threshold; and (3) calculating agreement among annotators using average per-layer precision, sensitivity, and Dice score. Results: The SS showed the largest difference in annotation frequency (31%) and the minimum overall agreement in terms of consensus size ( 3c28% of the labeled pixels). The average annotator\u2019s per-layer statistics showed consistent patterns, with lower agreement on the CBB and SS (average Dice score ranges of 0.61\u20130.7 and 0.73\u20130.78, respectively) and better agreement on the IR, TM, and C (average Dice score ranges of 0.97\u20130.98, 0.84\u20130.9, and 0.93\u20130.96, respectively). Conclusions: There was considerable inter-annotator variation in identifying contours of some anatomical layers in digital gonio photographs. Our pilot indicates that agreement was best on IR, TM, and C but poorer for CBB and SS. Translational Relevance: This study provides a comprehensive description of interannotator agreement on digital gonio photographs segmentation as a baseline for validating deep learning models for automated gonioscopy
Influence of gastrointestinal parasitism on biochemical variables in blood of laying hens
ABSTRACT
Objective. This study describes the influence of endoparasites and diet on biochemical variables in sera of brown laying hens. Materials and methods. Biochemical parameters (seric levels of cholesterol, triglycerides, total protein, uric acid, albumin, and alanine aminotransferase activity) were assessed in blood samples of poultry. Three populations of laying hens of different properties (n=20 each) represented our experimental design, from which blood (serum) and feces were collected for biochemical and parasitological analyzes, respectively. Results. From 60 feces samples evaluated 49 were positive for the presence of parasites and 11 were negative. Among the positive samples, 23 had infection with Eimeria spp and the other 26 samples had mixed parasitism with Eimeria spp and Heterakis gallinarum, which influenced (increasing) the levels of total protein and globulin. However, when parasites were analyzed separately, it was observed that the infection by Eimeria spp affected parameters such as cholesterol (which increased, p=0.001) and triglycerides, showing lower results than when the hen was parasitized by Eimeria spp. (p=0.01). Significant (p<0.05) difference was observed in all biochemical variables when the three diets were compared. Conclusions. Our results allowed concluding that the parasitic infection and diet in laying hens influenced the results of serum biochemical parameters evaluated. The main conclusion we found that parasitism caused an increase in total protein and globulin (ie immune response), and there was a negative correlation between parasite load and albumin, uric acid and ALT
Supplementation with spray-dried porcine plasma in piglets at birth: effects on protein metabolism and performance.
Resumo: Este estudo foi planejado para avaliar se a suplementação de leitões com plasma sanguíneo suíno desidratado (PSSP) no dia do nascimento tem efeito positivo sobre o metabolismo proteico e ganho de peso (GP) em leitões, bem como no desempenho na fase de creche. Selecionamos 30 leitegadas de marrãs, das quais, no mínimo um casal de leitões para cada tratamento/leitegada foi selecionado. Os tratamentos foram: TA = controle sem PSSP, TB = administração oral de 10 g de PSSP e TC = 20 g de PSSP. No nascimento, os leitões foram pesados, identificados e distribuídos aleatoriamente. Os pesos corporais também foram avaliados nos dias 7, 14 e 19. Foram coletadas amostras de sangue para medir o nível de uréia, proteína total (PT), albumina (AB) e globulina (GB). No desmame, 70 leitões de cada tratamento foram distribuídos em cinco grupos (réplicas) de 14 leitões (sete machos e sete fêmeas). Os dados de pesos (animais e consumo de ração) foram coletados no pós-desmame e também a cada troca de dieta (dias 14, 28 e 42 da fase de creche). Durante as duas primeiras semanas na maternidade, não houve efeitos dos tratamentos para todas as variáveis avaliadas. Na terceira semana, os leitões de TC apresentaram níveis séricos mais altos para as variáveis PT e GB, mas o GT foi menor nos leitões comparado ao controle. Não houve efeito dos tratamentos no GT durante todo o período lactente. Não houve efeitos residuais no desempenho da fase de creche; no entanto, os leitões tratados tiveram menos necessidade de medicamentos. A suplementação com PSSP não influenciou o desempenho zootécnico nas duas primeiras semanas ou durante todo o período lactente. O grupo TC apresentou níveis mais altos de globulina do que o grupo TA. Na fase de creche, não houve efeitos no desempenho; no entanto, houve uma maior incidência de animais doentes do grupo TA. Abstract: This research was designed to evaluate whether supplementation of piglets with spray dried porcine plasma (SDPP) on the day of birth, have positive effect on protein metabolism and weight gain (WG) in suckling piglets, as well as on performance at the nursery phase. We selected 30 litters from gilts of at least one pair of piglets for each treatment, TA= control without SDPP, TB= oral administration of 10 g of SDPP, and TC= 20 g of SDPP. At birth, the piglets were weighed, identified and randomly distributed. Body weights were also measured on days 7, 14 and 19. Blood samples were collected to measure the level of urea, total protein (TP), albumin (AB) and globulin (GB). At weaning, 70 piglets from each treatment were distributed in five groups (replicates) of 14 piglets (seven males and seven females). Weights (animals and feed intake) were taken at post-weaning and at each feed change (days 14, 28 and 42 of raising). During the first two weeks of lactation, there were no effects of the treatments for the all evaluated variables. In the third week, TC piglets had higher serum levels of TP and GB, but lower WG than did control piglets. There was no effect of treatments on WG during the entire suckling period. There were no residual effects on nursery phase performance; however, treated piglets had less need for medications. SDPP supplementation did not influence zootechnical performance in the first two weeks or during the entire suckling period. The TC group had higher globulin levels than did the TA group. In the weaning phase, there were no effects on performance; however, there was a higher incidence of diseased animals in the TA group. Resumen: Este estudio fue diseñado para evaluar si la suplementación de lechones con plasma porcino secado por atomización (PPSA) el día del nacimiento, tiene un efecto positivo sobre el metabolismo de las proteínas y el aumento de peso (AP) en lechones lactantes, así como el rendimiento en la fase de cría. Seleccionamos 30 camadas de marranas al menos un par de lechones para cada tratamiento: TA = control sin PPSA, TB = administración oral de 10 g de PPSA y TC = 20 g de PPSA. Al nacer, los lechones fueron pesados, identificados y distribuidos al azar. Los pesos corporales también se midieron los días 7, 14 y 19. Se recogieron muestras de sangre para medir el nivel de urea, proteína total (PT), albúmina (AB) y globulina (GB). Al destete, se distribuyeron 70 lechones de cada tratamiento en cinco grupos (réplicas) de 14 lechones (siete machos y siete hembras). Los pesos (animales y consumo de alimento) se tomaron después del destete y en cada cambio de alimento (días 14, 28 y 42 de crianza). Durante las primeras dos semanas de lactancia, no hubo efectos de los tratamientos para todas las variables evaluadas. En la tercera semana, los lechones TC tenían niveles séricos más altos de TP y GB, pero un AP más bajo que los lechones de control. No hubo efecto de los tratamientos sobre el AP durante todo el período de lactancia. No hubo efectos residuales en el rendimiento de la fase de vivero; sin embargo, los lechones tratados tenían menos necesidad de medicamentos. La suplementación con SDPP no influyó en el rendimiento zootécnico en las primeras dos semanas o durante todo el período de lactancia. El grupo TC tenía niveles de globulina más altos que el grupo TA. En la fase de destete, no hubo efectos en el rendimiento; sin embargo, hubo una mayor incidencia de animales enfermos en el grupo TA
Phase I, open-label study of pasireotide in patients with <i>BRAF-</i>wild type and <i>NRAS</i>-wild type, unresectable and/or metastatic melanoma.
Somatostatin analogues exert antitumour activity via direct and indirect mechanisms. The present study was designed to assess the safety and efficacy of pasireotide in patients with <i>BRAF</i> -wild type (WT) and <i>NRAS</i> -WT metastatic melanoma.
Patients with unresectable and/or metastatic melanoma or Merkel cell carcinoma were eligible. Pasireotide was administered at different doses for ≤8 weeks in dose-escalation phase, followed by long-acting pasireotide 80 mg or lower dose in case of toxicity in follow-up phase up to six additional months. Primary endpoint was safety in the first 8 weeks of dose-escalation phase.
The study was terminated early due to slow recruitment. Of the 10 patients with metastatic melanoma enrolled, only four reached the high dose level: two patients reached 3600 µg in dose-escalation and follow-up phases and two patients reached 3600 µg in dose-escalation and long-acting pasireotide 80 mg in follow-up phases and were stable for >5 months. Most common adverse events (AEs) during dose-escalation phase in ≥2 patients (20%) were: diarrhoea (50%), nausea (50%), fatigue (20%), hyperglycaemia (20%), hypophosphatemia (20%), chills (20%) and tumour pain (20%). Grade 3 or 4 study drug-related AEs were diarrhoea and nausea, reported in one patient. Partial response was documented in one patient and stable disease in another.
Pasireotide was well tolerated, and safety results were similar to those previously reported in other indications. Further studies are needed to evaluate its antitumour activity alone and in combination with other drugs in melanoma
Ventilazione ed esercizio
Relazione tra esercizio fisico e ventilazione .Descrizione del pattern ventilatorio e del lavoro della mucolatura respiratoria durante esercizio
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