1,332 research outputs found
Análisis antracológico preliminar del sitio arqueológico Los Tres Cerros 1 (Delta Superior del río Paraná), provincia de Entre Ríos
This contribution presents the first anthracological results of Los Tres Cerros 1 (LTC1) archaeological site, located in the insular zone of the Victoria department, Entre Ríos Province, in order to contribute to the understanding of the relationship between human groups whose inhabiting the site and the use of plant resources. The twelve radiocarbon dates obtained from the upper and middle levels of the site date the past human occupation between 1030 and 560 years BP. The coals concentrated and/or dispersed in stratigraphic position found during the excavation of the site were determined. The concentrated charcoals are considered as a sign of human selection and use of forest resources by past human populations, while the dispersed ones were employed to identify trees or shrubs landscape surrounding the mound. Arboreal elements: Ocotea sp. (Lauraceae), Sapium sp. (Euphorbiaceae), Enterolobium sp., Prosopis sp., Acacia sp. (Leguminoseae-Mimosoideae), Erythrina sp. (LeguminoseaePapilionoideae) and Cordia sp. (Boraginaceae); lianas elements: Passiflora? sp. (Passifloraceae?) and herbaceous elements: Cyperus sp. (Cyperaceae) were recognized. The results obtained in this paper are relevant to discuss the multiple uses of the plants by prehispanic human groups which inhabited the Upper Paraná Delta, either as fuels, raw materials for the manufacture of archaeological artifacts, housing or boats.En esta contribución se presentan los primeros análisis antracológicos del sitio arqueológico Los Tres Cerros 1 (LTC1), localizado en la zona insular del departamento Victoria, provincia de Entre Ríos, con la finalidad de contribuir a la comprensión de la relación entre los grupos que habitaban el lugar y la utilización de los recursos vegetales. Las doce dataciones radiocarbónicas obtenidas en los niveles superiores y medios del sitio indican que fue ocupado entre los 1030 y los 560 años AP. Se determinaron los carbones concentrados y/o dispersos hallados en estratigrafía durante la excavación. Los carbones concentrados responden al tipo de madera quemada en los fogones por las poblaciones humanas, mientras que los carbones dispersos aportan información sobre el paisaje herbáceo-leñoso de los alrededores del montículo. Se reconocieron elementos arbóreos asignados a: Ocotea sp. (Lauraceae), Sapium sp. (Euphorbiaceae), Enterolobium sp., Prosopis sp., Acacia sp. (Leguminoseae-Mimosoideae), Erythrina sp. (Leguminoseae-Papilionoideae) y Cordia sp. (Boraginaceae); lianas: Passiflora? sp. (Passifloraceae?) y elementos herbáceos de: Cyperus sp. (Cyperaceae). Los resultados obtenidos en este estudio son relevantes para discutir los múltiples usos que tuvieron las plantas entre las poblaciones prehispánicas del Delta Superior del Paraná, ya sea como combustibles, materias primas para la manufactura de artefactos, la construcción de viviendas y/o de embarcaciones
Inconsistency of the MLE for the joint distribution of interval censored survival times and continuous marks
This paper considers the nonparametric maximum likelihood estimator (MLE) for
the joint distribution function of an interval censored survival time and a
continuous mark variable. We provide a new explicit formula for the MLE in this
problem. We use this formula and the mark specific cumulative hazard function
of Huang and Louis (1998) to obtain the almost sure limit of the MLE. This
result leads to necessary and sufficient conditions for consistency of the MLE
which imply that the MLE is inconsistent in general. We show that the
inconsistency can be repaired by discretizing the marks. Our theoretical
results are supported by simulations.Comment: 27 pages, 4 figure
Digitally-enhanced lubricant evaluation scheme for hot stamping applications
Digitally-enhanced technologies are set to transform every aspect of manufacturing. Networks of sensors that compute at the edge (streamlining information flow from devices and providing real-time local data analysis), and emerging Cloud Finite Element Analysis technologies yield data at unprecedented scales, both in terms of volume and precision, providing information on complex processes and systems that had previously been impractical. Cloud Finite Element Analysis technologies enable proactive data collection in a supply chain of, for example the metal forming industry, throughout the life cycle of a product or process, which presents revolutionary opportunities for the development and evaluation of digitally-enhanced lubricants, which requires a coherent research agenda involving the merging of tribological knowledge, manufacturing and data science. In the present study, data obtained from a vast number of experimentally verified finite element simulation results is used for a metal forming process to develop a digitally-enhanced lubricant evaluation approach, by precisely representing the tribological boundary conditions at the workpiece/tooling interface, i.e., complex loading conditions of contact pressures, sliding speeds and temperatures. The presented approach combines the implementation of digital characteristics of the target forming process, data-guided lubricant testing and mechanism-based accurate theoretical modelling, enabling the development of data-centric lubricant limit diagrams and intuitive and quantitative evaluation of the lubricant performance
Case Report: Spontaneous Remission of an Infraorbital Follicular B-Cell Lymphoma: Case Report and Review of the Literature.
Non-Hodgkin lymphomas comprise a heterogeneous group of malignancies, with a wide scope of clinical, radiological and histological presentations. In this paper, a case is presented of a 59-year-old white male with an infraorbital follicular B-cell lymphoma, which appeared as a painless mass in the left cheek. The lymphoma achieved spontaneous remission five and a half months after his diagnostic incision biopsy. The literature is reviewed, focusing on this rare site of presentation and spontaneous remission. In literature, only four cases have been reported with a follicular B-cell lymphoma of the cheek or infraorbital region, and only 26 cases of spontaneous remission of an extracranial non-Hodgkin lymphoma in the head and neck region have been described. To the authors' best knowledge, this is the first time spontaneous remission of an infraorbital follicular lymphoma could be observed. The nature of the processes inducing spontaneous remission remains obscure. It is important to recognize this phenomenon as this might prevent unnecessary treatment
Clinical application of stem cell therapy in Parkinson's disease
Cell replacement therapies in Parkinson's disease (PD) aim to provide long-lasting relief of patients' symptoms. Previous clinical trials using transplantation of human fetal ventral mesencephalic (hfVM) tissue in the striata of PD patients have provided proof-of-principle that such grafts can restore striatal dopaminergic (DA-ergic) function. The transplants survive, reinnervate the striatum, and generate adequate symptomatic relief in some patients for more than a decade following operation. However, the initial clinical trials lacked homogeneity of outcomes and were hindered by the development of troublesome graft-induced dyskinesias in a subgroup of patients. Although recent knowledge has provided insights for overcoming these obstacles, it is unlikely that transplantation of hfVM tissue will become routine treatment for PD owing to problems with tissue availability and standardization of the grafts. The main focus now is on producing DA-ergic neuroblasts for transplantation from stem cells (SCs). There is a range of emerging sources of SCs for generating a DA-ergic fate in vitro. However, the translation of these efforts in vivo currently lacks efficacy and sustainability. A successful, clinically competitive SC therapy in PD needs to produce long-lasting symptomatic relief without side effects while counteracting PD progression
An efficient semiparametric maxima estimator of the extremal index
The extremal index , a measure of the degree of local dependence in
the extremes of a stationary process, plays an important role in extreme value
analyses. We estimate semiparametrically, using the relationship
between the distribution of block maxima and the marginal distribution of a
process to define a semiparametric model. We show that these semiparametric
estimators are simpler and substantially more efficient than their parametric
counterparts. We seek to improve efficiency further using maxima over sliding
blocks. A simulation study shows that the semiparametric estimators are
competitive with the leading estimators. An application to sea-surge heights
combines inferences about with a standard extreme value analysis of
block maxima to estimate marginal quantiles.Comment: 17 pages, 7 figures. Minor edits made to version 1 prior to journal
publication. The final publication is available at Springer via
http://dx.doi.org/10.1007/s10687-015-0221-
Layering and temperature-dependent magnetization and anisotropy of naturally produced Ni/NiO multilayers
Ni/NiO multilayers were grown by magnetron sputtering at room temperature,
with the aid of the natural oxidation procedure. That is, at the end of the
deposition of each single Ni layer, air is let to flow into the vacuum chamber
through a leak valve. Then, a very thin NiO layer (~1.2nm) is formed.
Simulated x-ray reflectivity patterns reveal that layering is excellent for
individual Ni-layer thickness larger than 2.5nm, which is attributed to the
intercalation of amorphous NiO between the polycrystalline Ni layers. The
magnetization of the films, measured at temperatures 5–300K, has almost bulk-
like value, whereas the films exhibit a trend to perpendicular magnetic
anisotropy (PMA) with an unusual significant positive interface anisotropy
contribution, which presents a weak temperature dependence. The power-law
behavior of the multilayers indicates a non-negligible contribution of higher
order anisotropies in the uniaxial anisotropy. Bloch-law fittings for the
temperature dependence of the magnetization in the spin-wave regime show that
the magnetization in the multilayers decreases faster as a function of
temperature than the one of bulk Ni. Finally, when the individual Ni-layer
thickness decreases below 2nm, the multilayer stacking vanishes, resulting in
a dramatic decrease of the interface magnetic anisotropy and consequently in a
decrease of the perpendicular magnetic anisotropy
A multicenter case registry study on medication-related osteonecrosis of the jaw in patients with advanced cancer
PURPOSE: This observational case registry study was designed to describe the natural history of cancer patients with medication-related osteonecrosis of the jaw (ONJ) and evaluate the ONJ resolution rate. METHODS: Adults with a diagnosis of cancer and with a new diagnosis of ONJ were enrolled and evaluated by a dental specialist at baseline and every 3 months for 2 years and then every 6 months for 3 years until death, consent withdrawal, or loss to follow-up. The primary endpoint was the rate and time course of ONJ resolution. Secondary endpoints included frequency of incident ONJ risk factors, ONJ treatment patterns, and treatment patterns of antiresorptive agents for subsequent ONJ. RESULTS: Overall, 327 patients were enrolled; 207 (63%) were continuing on study at data cutoff. Up to 69% of evaluable patients with ONJ had resolution or improvement during the study. ONJ resolution (AAOMS ONJ staging criteria) was observed in 114 patients (35%); median (interquartile range) time from ONJ onset to resolution was 7.3 (4.5-11.4) months. Most patients (97%) had received antiresorptive medication before ONJ development, 9 patients (3%) had not; 68% had received zoledronic acid, 38% had received denosumab, and 10% had received pamidronate (56% had received bisphosphonates only, 18% had received denosumab only, and 21% had exposure to both). CONCLUSIONS: These results are consistent with those observed in clinical trials evaluating skeletal-related events in patients with advanced malignancy involving bone. Longer follow-up will provide further information on ONJ recurrence and resolution rates between medically and surgically managed patients
Characterization of 3 PET Tracers for Quantification of Mitochondrial and Synaptic Function in Healthy Human Brain: {18}^F-BCPP-EF, {11}^C-SA-4503, and {11}^C-UCB-J
Mitochondrial complex 1 is involved in maintaining brain bioenergetics; σ-1 receptor responds to neuronal stress; and synaptic vesicle protein 2A reflects synaptic integrity. Expression of each of these proteins is altered in neurodegenerative diseases. Here, we characterize the kinetic behavior of 3 PET radioligands—{18}^F-BCPP-EF, {11}^C-SA-4503, and {11}^C-UCB-J for the measurement of mitochondrial complex 1, σ-1 receptor, and synaptic vesicle protein 2A, respectively, and determine appropriate analysis workflows for their application in future studies of the in vivo molecular pathology of these diseases. METHODS: Twelve human subjects underwent dynamic PET scans with each radioligand, including associated arterial blood sampling. A range of kinetic models was investigated to identify an optimal kinetic analysis method for each radioligand and a suitable acquisition duration. RESULTS: All 3 radioligands readily entered the brain and yielded heterogeneous uptake consistent with the known distribution of the targets. The optimal models determined for the regional estimates of volume of distribution were multilinear analysis 1 (MA1) and the 2-tissue-compartment model for {18}^F-BCPP-EF, MA1 for 11}^C-SA-4503, and both MA1 and the 1-tissue-compartment model for {11}^C-UCB-J, respectively, provided good estimates of regional volume of distribution values. An effect of age was observed on {18}^F-BCPP-EF and {11}^C-UCB-J signal in the caudate. CONCLUSION: These ligands can be assessed for their potential to stratify patients or monitor the progression of molecular neuropathology in neurodegenerative diseases
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