837 resultados para head tracking


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The use of antimicrobial agents has facilitated the dissemination of multi-resistant microorganisms, compromising dental and medical treatment. The aim of this study was to evaluate the distribution of different opportunistic microbial species in patients who suffered head and neck trauma, under temporary maintenance in nosocomial environment, particularly intensive care units, on the occurrence of such microorganisms in the oral cavity of the patients. It was selected 38 patients subjected to head and neck traumas. After emergency surgical procedures, clinical samples of saliva, sub and supragingival biofilms and mucosal surfaces were collected at two different moments: just after stabilization of the patient and soon after patients’ release from medical units. The presence of opportunistic and superinfecting microorganisms was evaluated by culture on selective and non-selective media, and the presence of the family Enterobacteriaceae, as well as genera Enterococcus, Pseudomonas, and Staphylococcus was assessed by PCR. It was found that the use of antimicrobials, even for short periods of time was sufficient to facilitate colonization by microorganisms of the families Enterobacteriaceae and Pseudomonadaceae, as well as yeasts and enterococci. These results support the concept that medical and dental teams should make a periodically change of antimicrobials used in treatment protocols in hospital for head and neck trauma patients, in order to minimize dissemination of opportunistic or superinfecting microorganisms.

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Collectively, the observations indicate that the overall warming of the Arctic system continued in 2007. There are some elements that are stabilizing or returning to climatological norms. These mixed tendencies illustrate the sensitivity and complexity of the Arctic System. Atmosphere: Hot spot shifts toward Europe Ocean: North Pole Temperatures at depth returning to 1990s values Sea Ice: Summer extent at record minimum Greenland: Recent warm temperatures associated with net ice loss Biology: increasing tundra shrub cover and variable treeline advance; up to 80% declines in some caribou herds while goose populations double Land: Increase in permafrost temperatures The Arctic Report Card 2007 is introduced as a means of presenting clear, reliable and concise information on recent observations of environmental conditions in the Arctic, relative to historical time series records. It provides a method of updating and expanding the content of the State of the Arctic Report, published in fall 2006, to reflect current conditions. Material presented in the Report Card is prepared by an international team of scientists and is peer-reviewed by topical experts nominated by the US Polar Research Board. The audience for the Arctic Report Card is wide, including scientists, students, teachers, decision makers and the general public interested in Arctic environment and science. The web-based format will facilitate future timely updates of the content.

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The U.S. Geological Survey (USGS) is committed to providing the Nation with credible scientific information that helps to enhance and protect the overall quality of life and that facilitates effective management of water, biological, energy, and mineral resources (http://www.usgs.gov/). Information on the Nation’s water resources is critical to ensuring long-term availability of water that is safe for drinking and recreation and is suitable for industry, irrigation, and fish and wildlife. Population growth and increasing demands for water make the availability of that water, now measured in terms of quantity and quality, even more essential to the long-term sustainability of our communities and ecosystems. The USGS implemented the National Water-Quality Assessment (NAWQA) Program in 1991 to support national, regional, State, and local information needs and decisions related to water-quality management and policy (http://water.usgs.gov/nawqa). The NAWQA Program is designed to answer: What is the condition of our Nation’s streams and ground water? How are conditions changing over time? How do natural features and human activities affect the quality of streams and ground water, and where are those effects most pronounced? By combining information on water chemistry, physical characteristics, stream habitat, and aquatic life, the NAWQA Program aims to provide science-based insights for current and emerging water issues and priorities. From 1991-2001, the NAWQA Program completed interdisciplinary assessments and established a baseline understanding of water-quality conditions in 51 of the Nation’s river basins and aquifers, referred to as Study Units (http://water.usgs.gov/nawqa/studyu.html).

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The integration of CMOS cameras with embedded processors and wireless communication devices has enabled the development of distributed wireless vision systems. Wireless Vision Sensor Networks (WVSNs), which consist of wirelessly connected embedded systems with vision and sensing capabilities, provide wide variety of application areas that have not been possible to realize with the wall-powered vision systems with wired links or scalar-data based wireless sensor networks. In this paper, the design of a middleware for a wireless vision sensor node is presented for the realization of WVSNs. The implemented wireless vision sensor node is tested through a simple vision application to study and analyze its capabilities, and determine the challenges in distributed vision applications through a wireless network of low-power embedded devices. The results of this paper highlight the practical concerns for the development of efficient image processing and communication solutions for WVSNs and emphasize the need for cross-layer solutions that unify these two so-far-independent research areas.

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A low-cost circuit was developed for stable and efficient maximum power point (MPP) tracking in autonomous photo voltaic-motor systems with variable-frequency drives (VFDs). The circuit is made of two resistors, two capacitors, and two Zener diodes. Its input is the photovoltaic (PV) array voltage and its output feeds the proportional-integral-derivative (PID) controller usually integrated into, the drive. The steady-state frequency-voltage oscillations induced by the circuit were treated in a simplified mathematical model, which was validated by widely characterizing a PV-powered centrifugal pump. General procedures for circuit and controller tuning were recommended based on model equations. The tracking circuit presented here is widely applicable to PV-motor system with VFDs, offering an. efficient open-access technology of unique simplicity. Copyright (C) 2010 John Wiley & Sons, Ltd.

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Previous studies have reported increased cerebral blood flow (CBF) velocity after decompressive craniectomy in traumatic brain injury (TBI) patients. A 27-year-old man presented with clinical and tomographic signs of cerebral herniation secondary to TBI. Prior to decompressive craniectomy, hemodynamic study by perfusion computed tomography (CT) indicated diffuse cerebral hyperperfusion. Following surgical decompression, the patient recovered neurologically and perfusion CT disclosed a decrease in the intensity of cerebral perfusion. The patient's blood pressure levels were similar at both pre- and postoperative perfusion CT examinations. This finding provides indirect evidence that decompressive craniectomy may improve mechanisms of CBF regulation in TBI, providing pathophysiological insights in the cerebral hemodynamics of TBI patients. This is the first report analyzing the hemodynamic changes through perfusion CT (PCT) in a patient with decompressive craniotomy due to TBI. (C) 2012 Elsevier Masson SAS. All rights reserved.

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This study aimed to investigate the frequency of symptoms of depression in patients with cancer of the head and neck undergoing radiotherapy treatment, in the initial, middle and final stages of the treatment. This is a prospective exploratory quantitative study of 41 patients with head and neck cancer, undergoing radiotherapy treatment in the Oncology Outpatient Clinic of the Beneficencia Portuguese Hospital of Ribeirao Preto. Data were collected through the Beck Depression Inventory instrument, and analyzed quantitatively by means of the Statistical Package for the Social Sciences. Symptoms of dysphoria were found to increase throughout the treatment, as well as the number of patients with depression. The results show the importance for the healthcare professionals to detect the prevalence and the levels of the symptoms of depression, since these symptoms tend to increase and may lead to consequences such as a lack of adherence to treatment and a decrease in the quality of life of these patients.

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This paper presents an optimum user-steered boundary tracking approach for image segmentation, which simulates the behavior of water flowing through a riverbed. The riverbed approach was devised using the image foresting transform with a never-exploited connectivity function. We analyze its properties in the derived image graphs and discuss its theoretical relation with other popular methods such as live wire and graph cuts. Several experiments show that riverbed can significantly reduce the number of user interactions (anchor points), as compared to live wire for objects with complex shapes. This paper also includes a discussion about how to combine different methods in order to take advantage of their complementary strengths.

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Loss of Y-chromosome has been correlated with older age in males. Furthermore, current evidence indicates that Y-chromosome loss also occurs in several human tumors, including head and neck carcinomas. However, the association between Y nullisomy and the occurrence of neoplasias in elderly men has not been well established. In the present study, the association between Y-chromosome loss and head and neck carcinomas was evaluated by comparison to cells from peripheral blood lymphocytes and normal mucosa of cancer-free individuals matched for age using dual-color fluorescence in situ hybridization. Twenty-one patients ranging in age from 28 to 68 years were divided into five-year groups for comparison with 16 cancer-free individuals matched for age. The medical records of all patients were examined to obtain clinical and histopathological data. None of the patients had undergone radiotherapy or chemotherapy before surgery. In all groups, the frequency of Y-chromosome loss was higher among patients than among normal reference subjects (P < 0.0001) and was not age-dependent. These data suggest that Y-chromosome loss is a tumor-specific alteration not associated with advanced age in head and neck carcinomas.

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OBJECTIVE: This study aims to evaluate the production of interferon-gamma and interleukin-10 by stimulated peripheral blood mononuclear cells isolated from patients with supraglottic laryngeal cancer before and after surgical treatment. METHODS: Fourteen patients with advanced supraglottic laryngeal cancer were studied. Cultures of peripheral blood mononuclear cells isolated during the preoperative and late postoperative periods were stimulated with concanavalin A and Bacille Calmette-Guerin, and the supernatant concentrations of interferon-gamma and interleukin-10 were measured. RESULTS: For non-stimulated cultures, the interferon-gamma levels produced by the preoperative period and the late postoperative period cultures were lower than the levels produced by the control group cultures. The interferon-gamma levels after stimulation with concanavalin A were higher in the late postoperative period cultures than in the preoperative evaluation cultures. Stimulation with Bacille Calmette-Guerin led to the production of similar levels of interferon-gamma and interleukin-10 by all cultures; thus, stimulation increased the levels of interferon-gamma produced by both the preoperative and postoperative cultures relative to the levels produced by the corresponding unstimulated cultures. CONCLUSION: Patients with advanced supraglottic laryngeal cancer exhibit an in vitro deficiency in interferongamma secretion by mononuclear cells. Stimulated cells seem to recover this function during the postoperative period.

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Calcium carbonate is one of the most important biominerals, and it is the main constituent of pearls, seashells, and teeth. The in vitro crystallization of calcium carbonate using different organic matrices as templates has been reported. In this work, the growth of calcium carbonate thin films on special organic matrices consisting of layer-by-layer (LbL) polyelectrolyte films deposited on a pre-formed phospholipid Langmuir-Blodgett (LB) film has been studied. Two types of randomly coiled polyelectrolytes have been used: lambda-carrageenan and poly(acrylic acid). A precoating comprised of LB films has been prepared by employing a negatively charged phospholipid, the sodium salt of dimyristoilphosphatidyl acid (DMPA), or a zwitterionic phospholipid, namely dimyristoilphosphatidylethanolamine (DMPE). This approach resulted in the formation of particulate calcium carbonate continuous films with different morphologies, particle sizes, and roughness, as revealed by scanning electron microscopy (SEM) and atomic force microscopy (AFM). The crystalline structure of the calcium carbonate particles was analyzed by Raman spectroscopy. The randomly coiled conformation of the polyelectrolytes seems to be the main reason for the formation of continuous films rather than CaCO3 isolated crystals. (C) 2012 Elsevier B.V. All rights reserved.

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Objectives: The Head and Neck Squamous Cell Carcinoma (HNSCC) ranks sixth worldwide. The mechanisms of growth, invasion and metastasis of this pathology are extensively studied and generally related to specific variations in signaling pathways like the PI3K-Akt; however most of these competent studies have been performed bidimensionally, which may hide important questions. This study sought to analyze the influence of the microenvironment upon the behavior of HNSCC. Study Design: The status of pAkt, NF-kappa B and Cyclin D1 proteins was accessed through immunofluorescence and western blot methods in HNSCC cell lines originating from tongue, pharynx and metastatic lymph node when submitted to a three-dimensional culture model utilizing a matrix system. A bidimensional culture model (monolayer) was used as control. Results: The HNSCC cell lines cultured three-dimensionally exhibited a growth pattern characterized by small isolated islands, different from the control group. When the three-dimensional model was applied, two of the studied cell lines showed the same expression pattern as the bidimensional model regarding nuclear or cytoplasmatic localization, as well as reduction of all protein levels; however, the cell line originated from tongue, which specially has the epidermal growth factor receptor constitutively activated, demonstrated nuclear translocation of pAkt and also an increase in the levels of Cyclin D1. Conclusions: The results suggest the influence of the microenvironment upon the behavior of HNSCC cells due to the changed expression of proteins related to tumor growth and cellular invasion. Furthermore, intrinsically genetic conditions also played important roles over the cells, despite the culture model employed.

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To investigate the potential role of vitamin or mineral supplementation on the risk of head and neck cancer (HNC), we analyzed individual-level pooled data from 12 casecontrol studies (7,002 HNC cases and 8,383 controls) participating in the International Head and Neck Cancer Epidemiology consortium. There were a total of 2,028 oral cavity cancer, 2,465 pharyngeal cancer, 874 unspecified oral/pharynx cancer, 1,329 laryngeal cancer and 306 overlapping HNC cases. Odds ratios (OR) and 95% confidence intervals (CIs) for self reported ever use of any vitamins, multivitamins, vitamin A, vitamin C, vitamin E, and calcium, beta-carotene, iron, selenium and zinc supplements were assessed. We further examined frequency, duration and cumulative exposure of each vitamin or mineral when possible and stratified by smoking and drinking status. All ORs were adjusted for age, sex, race/ethnicity, study center, education level, pack-years of smoking, frequency of alcohol drinking and fruit/vegetable intake. A decreased risk of HNC was observed with ever use of vitamin C (OR = 0.76, 95% CI = 0.590.96) and with ever use of calcium supplement (OR = 0.64, 95% CI = 0.420.97). The inverse association with HNC risk was also observed for 10 or more years of vitamin C use (OR = 0.72, 95% CI = 0.540.97) and more than 365 tablets of cumulative calcium intake (OR = 0.36, 95% CI = 0.160.83), but linear trends were not observed for the frequency or duration of any supplement intake. We did not observe any strong associations between vitamin or mineral supplement intake and the risk of HNC.

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To assess the prevalence of depression and fatigue symptoms in head and neck cancer patients during radiotherapy treatment and relate them symptoms with these patients' quality of life. This is a prospective study. The Beck Depression Inventory (BDI), Piper Fatigue Scale-revised and Functional Assessment Cancer Therapy Head and Neck (FACT-H&N) were applied to 41 head and neck cancer patients at three times: at the start of treatment (T1), approximately 15 days after the start of treatment (T2) and at the end of treatment (T3), approximately 30 days after the start of the radiotherapy. The mean BDI and PIPER increased during the radiotherapy treatment. BDI scores did not demonstrate the presence of depression, although the number of symptoms increased, and the presence of fatigue rose as treatment advanced. The mean FACT H&N decreased in the middle and at the end of treatment, indicating worsening in these patients' Quality of Life. Depression and fatigue symptoms increased during radiotherapy treatment, while QoL levels decreased. This demonstrates that these symptoms are strongly correlated and that their presence negatively influenced QoL. At the start of treatment, nurses need to advise patients and plan care, offering interventions to decrease these symptoms and improve QoL.