951 resultados para Kim, Jaegwon: Physicalism, or something near enough
Resumo:
Breeding birds vocalize to find mates and establish and defend territories, but these same critical communications may also attract predators or brood parasites, placing birds in a cruel bind. Although vigilant birds may better maintain social relationships with mates and neighbors through frequent vocalizations, reticent birds may reduce risk to their nests by being relatively quiet and making infrequent vocalizations. Selection for vocalization patterns that minimize brood parasitism might be particularly strong for birds that are unable to fledge both their own young and the parasite. Temporal plasticity in the frequency of vocalizations near nests, however, may allow birds to balance trade-offs and optimize nest-defense strategies. The Black-capped Vireo (Vireo atricapilla) is an endangered songbird that faces intensive brood parasitism in areas where Brown-headed Cowbirds (Molothrus ater) are present. Vireo nests that produce cowbird fledglings always fail to fledge vireo young. We recorded vocalizations at vireo nests across three nesting stages (building, laying, and early incubation) and three periods of the day (morning, midday, and evening) and compared vocalization frequency with eventual depredation or parasitism fate as well as local cowbird density to test two hypotheses. The predator-attraction hypothesis predicts that predators will be attracted by frequent vocalizations, whereas cowbirds will parasitize nests with relatively quiet parents and less predation risk; thus, vireos will experience trade-offs between reticence and vigilance in mediating specific risks. The parasite-assessment hypothesis predicts that vireos will become more secretive as local cowbird densities increase. Vireo vocalization response to nest predation and parasitism risk interacted with nest stage, and we found little evidence of risk mediation through vocalizations except during the building stage. Vireos, however, did benefit overall by optimizing temporal patterns in vocalizations. Vireo nests were less likely to be depredated or parasitized if males vocalized most during laying and least during the middle of the day. Birds vocalized more during the midday and less during the laying period when local cowbird densities were higher, however, perhaps demonstrating limited plasticity in social communication.
Resumo:
Introducción: la colecistectomía laparoscópica es la técnica de elección en pacientes con indicación de extracción quirúrgica de la vesícula; sin embargo, en promedio 20% de éstos requieren conversión a técnica abierta. En este estudio se evaluaron los factores de riesgo preoperatorios para conversión en colecistectomía laparoscópica de urgencia. Metodología: se realizó un estudio de casos y controles no pareado. Se obtuvo información sociodemográfica y de variables de interés de los registros de historias clínicas de pacientes operados entre el 2013 y 2016. Se identificaron los motivos de conversión de técnica quirúrgica. Se caracterizó la población de estudio y se estimaron asociaciones según la naturaleza de las variables. Mediante un análisis de regresión logística se ajustaron posibles variables de confusión. Resultados: se analizaron los datos de 444 pacientes (111 casos y 333 controles). La causa de conversión más frecuente fue la dificultad técnica (50,5%). Se encontró que la mayor edad, el sexo masculino, el antecedente de cirugía abierta en hemiabdomen superior, el signo de Murphy clínico positivo, la dilatación de la vía biliar, la leucocitosis y la mayor experiencia del cirujano, fueron factores de riesgo para conversión. Se encontró un área bajo la curva ROC= 0,743 (IC95% 0,692–0,794, p= <0,001). Discusión: existen unos factores que se asocian a mayor riesgo de conversión en colecistectomía laparoscópica. La mayoría se relacionan con un proceso inflamatorio más severo, por lo que se debe evitar la prolongación del tiempo de espera entre el inicio de los síntomas y la extirpación quirúrgica de la vesícula.
Resumo:
Se presentan los modelos de hopping de rango variable (variable range hopping; VRH), vecinos cercanos (nearest neighbor hopping; NNH) y barreras de potencial presentes en las fronteras de grano; como mecanismos de transporte eléctrico predominantes en los materiales semiconductores para aplicaciones fotovoltaicas. Las medidas de conductividad a oscuras en función de temperatura fueron realizadas para región de bajas temperaturas entre 120 y 400 K con Si y compuestos Cu3BiS2 y Cu2ZnSnSe4. Siguiendo la teoría de percolación, se obtuvieron parámetros hopping y la densidad de estados cerca del nivel de Fermi, N(EF), para todas las muestras. A partir de los planteamientos dados por Mott para VRH, se presentó el modelo difusional, que permitió establecer la relación entre la conductividad y la densidad de estados de defecto o estados localizados en el gap del material. El análisis comparativo entre modelos, evidenció, que es posible obtener mejora hasta de un orden de magnitud en valores para cada uno de los parámetros hopping que caracterizan el material.
Resumo:
The signature of 60Fe in deep-sea crusts indicates that one or more supernovae exploded in the solar neighbourhood about 2.2 million years ago1–4. Recent isotopic analysis is consistent with a core-collapse or electron-capture supernova that occurred 60 to 130 parsecs from the Sun5. Moreover, peculiarities in the cosmic ray spectrum point to a nearby supernova about two million years ago6. The Local Bubble of hot, diffuse plasma, in which the Solar System is embedded, originated from 14 to 20 supernovae within a moving group, whose surviving members are now in the Scorpius– Centaurus stellar association7,8. Here we report calculations of the most probable trajectories and masses of the supernova progenitors, and hence their explosion times and sites. The 60Fe signal arises from two supernovae at distances between 90 and 100 parsecs. The closest occurred 2.3 million years ago at present-day galactic coordinates l = 327°, b = 11°, and the second-closest exploded about 1.5 million years ago at l = 343°, b = 25°, with masses of 9.2 and 8.8 times the solar mass, respectively. The remaining supernovae, which formed the Local Bubble, contribute to a smaller extent because they happened at larger distances and longer ago (60Fe has a half- life of 2.6 million years9,10). There are uncertainties relating to the nucleosynthesis yields and the loss of 60Fe during transport, but they do not influence the relative distribution of 60Fe in the crust layers, and therefore our model reproduces the measured relative abundances very well.
Resumo:
Wireless Power Transfer has become a promising technology to overcome the limits of wired solutions. Within this framework, the objective of this thesis is to study a WPT link at millimeter waves involving a particular type of antenna working in the radiative near-field, known as Bessel Beam (BB) Launcher. This antenna has been chosen for its peculiarity of generating a Bessel Beam which is by nature non-diffractive, showing good focusing and self-healing capabilities. In particular, a Bull-Eye Leaky Wave Antenna is designed and analysed, fed by a loop antenna and resonating at approximately 30 GHz. The structure excites a Hybrid-TE mode showing zeroth-order Bessel function over the z-component of the magnetic field. The same antenna is designed with two different dimensions, showing good wireless power transport properties. The link budgets obtained for different configurations are reported. With the aim of exploiting BB Launchers in wearable applications, a further analysis on the receiving part is conducted. For WPT wearable or implantable devices a reduced dimension of the receiver system must be considered. Therefore, an electrically large loop antenna in planar technology is modified, inserting phase shifters in order to increase the intensity of the magnetic field in its interrogation zone. This is fundamental when a BB Launcher is involved as transmitter. The loop antenna, in reception, shows a further miniaturization level since it is built such that its interrogation zone corresponds to the main beam dimension of transmitting BB Launcher. The link budget is evaluated with the new receiver showing comparable results with respect to previous configurations, showing an efficient WPT link for near-field focusing. Finally, a matching network and a full-wave rectifying circuit are attached to two of the different receiving systems considered. Further analysis will be carried out about the robustness of the square loop over biological tissues.
Resumo:
This PhD research investigates sealing practices in the Near East during the Late Bronze II period (ca. 1375-1175 BCE). Sealings from archaeological contexts in the Southern Levant, North Syria, Upper and Lower Mesopotamia and South-Western Iran are taken under consideration and analyzed on multiple aspects at local, regional, and international levels. The contextual, functional, and iconographic analysis of these materials, in fact, allows to reconstruct the nature of the transactions and the agents involved in the sealing operations within local administrative systems, highlighting at the same time aspects of inter-regional interactions during the age of internationalism. Following a survey of the available evidence, a corpus consisting of 1845 records from 28 different sites across the ANE, has been filed using MS Access and MS Excel, including 740 unpublished sealing from Karkemish. Among this large evidence, the corpus of recently discovered sealings from Karkemish and the other scattered sealings from the North Syrian provinces, for instance, provide insights on the core-periphery relationships under the Hittite Empire; while the deposit from Building P at Tell Sheikh Hamad, that of the Middle Assyrian houses at Tell Fekheriye, and of the dunnu of Tell Sabi Abyad, significantly contributes to defining the administration of provinces within the Middle Assyrian state and the regional circulation of good. The less extensive evidence from South Mesopotamia under the Kassite rule and from Middle Elamite contexts in South-Western Iran somewhat contribute as well to the understanding of sealing practices in the LB II period. The South Levantine kingdoms, on the other hand, seems participates to the Egyptian regional network of exchanges and sealing practices.
Resumo:
Revascularization outcome depends on microbial elimination because apical repair will not happen in the presence of infected tissues. This study evaluated the microbial composition of traumatized immature teeth and assessed their reduction during different stages of the revascularization procedures performed with 2 intracanal medicaments. Fifteen patients (7-17 years old) with immature teeth were submitted to the revascularization procedures; they were divided into 2 groups according to the intracanal medicament used: TAP group (n = 7), medicated with a triple antibiotic paste, and CHP group (n = 8), dressed with calcium hydroxide + 2% chlorhexidine gel. Samples were taken before any treatment (S1), after irrigation with 6% NaOCl (S2), after irrigation with 2% chlorhexidine (S3), after intracanal dressing (S4), and after 17% EDTA irrigation (S5). Cultivable bacteria recovered from the 5 stages were counted and identified by means of polymerase chain reaction assay (16S rRNA). Both groups had colony-forming unit counts significantly reduced after S2 (P < .05); however, no significant difference was found between the irrigants (S2 and S3, P = .99). No difference in bacteria counts was found between the intracanal medicaments used (P = .95). The most prevalent bacteria detected were Actinomyces naeslundii (66.67%), followed by Porphyromonas endodontalis, Parvimonas micra, and Fusobacterium nucleatum, which were detected in 33.34% of the root canals. An average of 2.13 species per canal was found, and no statistical correlation was observed between bacterial species and clinical/radiographic features. The microbial profile of infected immature teeth is similar to that of primarily infected permanent teeth. The greatest bacterial reduction was promoted by the irrigation solutions. The revascularization protocols that used the tested intracanal medicaments were efficient in reducing viable bacteria in necrotic immature teeth.
Resumo:
A miniaturised gas analyser is described and evaluated based on the use of a substrate-integrated hollow waveguide (iHWG) coupled to a microsized near-infrared spectrophotometer comprising a linear variable filter and an array of InGaAs detectors. This gas sensing system was applied to analyse surrogate samples of natural fuel gas containing methane, ethane, propane and butane, quantified by using multivariate regression models based on partial least square (PLS) algorithms and Savitzky-Golay 1(st) derivative data preprocessing. The external validation of the obtained models reveals root mean square errors of prediction of 0.37, 0.36, 0.67 and 0.37% (v/v), for methane, ethane, propane and butane, respectively. The developed sensing system provides particularly rapid response times upon composition changes of the gaseous sample (approximately 2 s) due the minute volume of the iHWG-based measurement cell. The sensing system developed in this study is fully portable with a hand-held sized analyser footprint, and thus ideally suited for field analysis. Last but not least, the obtained results corroborate the potential of NIR-iHWG analysers for monitoring the quality of natural gas and petrochemical gaseous products.
Resumo:
Sexual dysfunction (SD) affects up to 80% of multiple sclerosis (MS) patients and pelvic floor muscles (PFMs) play an important role in the sexual function of these patients. The objective of this paper is to evaluate the impact of a rehabilitation program to treat lower urinary tract symptoms on SD of women with MS. Thirty MS women were randomly allocated to one of three groups: pelvic floor muscle training (PFMT) with electromyographic (EMG) biofeedback and sham neuromuscular electrostimulation (NMES) (Group I), PFMT with EMG biofeedback and intravaginal NMES (Group II), and PFMT with EMG biofeedback and transcutaneous tibial nerve stimulation (TTNS) (Group III). Assessments, before and after the treatment, included: PFM function, PFM tone, flexibility of the vaginal opening and ability to relax the PFMs, and the Female Sexual Function Index (FSFI) questionnaire. After treatment, all groups showed improvements in all domains of the PERFECT scheme. PFM tone and flexibility of the vaginal opening was lower after the intervention only for Group II. All groups improved in arousal, lubrication, satisfaction and total score domains of the FSFI questionnaire. This study indicates that PFMT alone or in combination with intravaginal NMES or TTNS contributes to the improvement of SD.
Resumo:
The vast majority of maternal deaths in low-and middle-income countries are preventable. Delay in obtaining access to appropriate health care is a fairly common problem which can be improved. The objective of this study was to explore the association between delay in providing obstetric health care and severe maternal morbidity/death. This was a multicentre cross-sectional study, involving 27 referral obstetric facilities in all Brazilian regions between 2009 and 2010. All women admitted to the hospital with a pregnancy-related cause were screened, searching for potentially life-threatening conditions (PLTC), maternal death (MD) and maternal near-miss (MNM) cases, according to the WHO criteria. Data on delays were collected by medical chart review and interview with the medical staff. The prevalence of the three different types of delays was estimated according to the level of care and outcome of the complication. For factors associated with any delay, the PR and 95%CI controlled for cluster design were estimated. A total of 82,144 live births were screened, with 9,555 PLTC, MNM or MD cases prospectively identified. Overall, any type of delay was observed in 53.8% of cases; delay related to user factors was observed in 10.2%, 34.6% of delays were related to health service accessibility and 25.7% were related to quality of medical care. The occurrence of any delay was associated with increasing severity of maternal outcome: 52% in PLTC, 68.4% in MNM and 84.1% in MD. Although this was not a population-based study and the results could not be generalized, there was a very clear and significant association between frequency of delay and severity of outcome, suggesting that timely and proper management are related to survival.
Resumo:
69
Resumo:
Split-plot design (SPD) and near-infrared chemical imaging were used to study the homogeneity of the drug paracetamol loaded in films and prepared from mixtures of the biocompatible polymers hydroxypropyl methylcellulose, polyvinylpyrrolidone, and polyethyleneglycol. The study was split into two parts: a partial least-squares (PLS) model was developed for a pixel-to-pixel quantification of the drug loaded into films. Afterwards, a SPD was developed to study the influence of the polymeric composition of films and the two process conditions related to their preparation (percentage of the drug in the formulations and curing temperature) on the homogeneity of the drug dispersed in the polymeric matrix. Chemical images of each formulation of the SPD were obtained by pixel-to-pixel predictions of the drug using the PLS model of the first part, and macropixel analyses were performed for each image to obtain the y-responses (homogeneity parameter). The design was modeled using PLS regression, allowing only the most relevant factors to remain in the final model. The interpretation of the SPD was enhanced by utilizing the orthogonal PLS algorithm, where the y-orthogonal variations in the design were separated from the y-correlated variation.
Resumo:
Seizures in some 30% to 40% of patients with epilepsy fail to respond to antiepileptic drugs or other treatments. While much has been made of the risks of new drug therapies, not enough attention has been given to the risks of uncontrolled and progressive epilepsy. This critical review summarizes known risks associated with refractory epilepsy, provides practical clinical recommendations, and indicates areas for future research. Eight international epilepsy experts from Europe, the United States, and South America met on May 4, 2013, to present, review, and discuss relevant concepts, data, and literature on the consequences of refractory epilepsy. While patients with refractory epilepsy represent the minority of the population with epilepsy, they require the overwhelming majority of time, effort, and focus from treating physicians. They also represent the greatest economic and psychosocial burdens. Diagnostic procedures and medical/surgical treatments are not without risks. Overlooked, however, is that these risks are usually smaller than the risks of long-term, uncontrolled seizures. Refractory epilepsy may be progressive, carrying risks of structural damage to the brain and nervous system, comorbidities (osteoporosis, fractures), and increased mortality (from suicide, accidents, sudden unexpected death in epilepsy, pneumonia, vascular disease), as well as psychological (depression, anxiety), educational, social (stigma, driving), and vocational consequences. Adding to this burden is neuropsychiatric impairment caused by underlying epileptogenic processes (essential comorbidities), which appears to be independent of the effects of ongoing seizures themselves. Tolerating persistent seizures or chronic medicinal adverse effects has risks and consequences that often outweigh risks of seemingly more aggressive treatments. Future research should focus not only on controlling seizures but also on preventing these consequences.
Resumo:
To assess quality of care of women with severe maternal morbidity and to identify associated factors. This is a national multicenter cross-sectional study performing surveillance for severe maternal morbidity, using the World Health Organization criteria. The expected number of maternal deaths was calculated with the maternal severity index (MSI) based on the severity of complication, and the standardized mortality ratio (SMR) for each center was estimated. Analyses on the adequacy of care were performed. 17 hospitals were classified as providing adequate and 10 as nonadequate care. Besides almost twofold increase in maternal mortality ratio, the main factors associated with nonadequate performance were geographic difficulty in accessing health services (P < 0.001), delays related to quality of medical care (P = 0.012), absence of blood derivatives (P = 0.013), difficulties of communication between health services (P = 0.004), and any delay during the whole process (P = 0.039). This is an example of how evaluation of the performance of health services is possible, using a benchmarking tool specific to Obstetrics. In this study the MSI was a useful tool for identifying differences in maternal mortality ratios and factors associated with nonadequate performance of care.
Resumo:
Obstructive lung diseases of different etiologies present with progressive peripheral airway involvement. The peripheral airways, known as the silent lung zone, are not adequately evaluated with conventional function tests. The principle of gas washout has been used to detect pulmonary ventilation inhomogeneity and to estimate the location of the underlying disease process. Volumetric capnography (VC) analyzes the pattern of CO2 elimination as a function of expired volume. To measure normalized phase 3 slopes with VC in patients with non-cystic fibrosis bronchiectasis (NCB) and in bronchitic patients with chronic obstructive pulmonary disease (COPD) in order to compare the slopes obtained for the groups. NCB and severe COPD were enrolled sequentially from an outpatient clinic (Hospital of the State University of Campinas). A control group was established for the NCB group, paired by sex and age. All subjects performed spirometry, VC, and the 6-Minute Walk Test (6MWT). Two comparisons were made: NCB group versus its control group, and NCB group versus COPD group. The project was approved by the ethical committee of the institution. Statistical tests used were Wilcoxon or Student's t-test; P<0.05 was considered to be a statistically significant difference. Concerning the NCB group (N=20) versus the control group (N=20), significant differences were found in body mass index and in several functional variables (spirometric, VC, 6MWT) with worse results observed in the NCB group. In the comparison between the COPD group (N=20) versus the NCB group, although patients with COPD had worse spirometric and 6MWT values, the capnographic variables mean phase 2 slope (Slp2), mean phase 3 slope normalized by the mean expiratory volume, or mean phase 3 slope normalized by the end-tidal CO2 concentration were similar. These findings may indicate that the gas elimination curves are not sensitive enough to monitor the severity of structural abnormalities. The role of normalized phase 3 slope may be worth exploring as a more sensitive index of small airway disease, even though it may not be equally sensitive in discriminating the severity of the alterations.