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‣ Slow oscillation electrical brain stimulation during waking promotes EEG theta activity and memory encoding

Kirov, Roumen; Weiss, Carsten; Siebner, Hartwig R.; Born, Jan; Marshall, Lisa
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
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The application of transcranial slow oscillation stimulation (tSOS; 0.75 Hz) was previously shown to enhance widespread endogenous EEG slow oscillatory activity when applied during a sleep period characterized by emerging endogenous slow oscillatory activity. Processes of memory consolidation typically occurring during this state of sleep were also enhanced. Here, we show that the same tSOS applied in the waking brain also induced an increase in endogenous EEG slow oscillations (0.4–1.2 Hz), although in a topographically restricted fashion. Applied during wakefulness tSOS, additionally, resulted in a marked and widespread increase in EEG theta (4–8 Hz) activity. During wake, tSOS did not enhance consolidation of memories when applied after learning, but improved encoding of hippocampus-dependent memories when applied during learning. We conclude that the EEG frequency and related memory processes induced by tSOS critically depend on brain state. In response to tSOS during wakefulness the brain transposes stimulation by responding preferentially with theta oscillations and facilitated encoding.

‣ Transformations, transport, and potential unintended consequences of high sulfur inputs to Napa Valley vineyards

Hinckley, Eve-Lyn S.; Matson, Pamela A.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
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Unintended anthropogenic deposition of sulfur (S) to forest ecosystems has a range of negative consequences, identified through decades of research. There has been far less study of purposeful S use in agricultural systems around the world, including the application of elemental sulfur (S0) as a quick-reacting fungicide to prevent damage to crops. Here we report results from a three-year study of the transformations and flows of applied S0 in soils, vegetation, and hydrologic export pathways of Napa Valley, CA vineyards, documenting that all applied S is lost from the vineyard ecosystem on an annual basis. We found that S0 oxidizes rapidly to sulfate () on the soil surface where it then accumulates over the course of the growing season. Leaf and grape tissues accounted for only 7–13% of applied S whereas dormant season cover crops accounted for 4–10% of applications. Soil S inventories were largely and ester-bonded sulfates; they decreased from 1,623 ± 354 kg ha-1 during the dry growing season to 981 ± 526 kg ha-1 (0–0.5 m) during the dormant wet season. Nearly all S applied to the vineyard soils is transported offsite in dissolved oxidized forms during dormant season rainstorms. Thus, the residence time of reactive S is brief in these systems...

‣ High-yield maize with large net energy yield and small global warming intensity

Grassini, Patricio; Cassman, Kenneth G.
Fonte: National Academy of Sciences Publicador: National Academy of Sciences
Tipo: Artigo de Revista Científica
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Addressing concerns about future food supply and climate change requires management practices that maximize productivity per unit of arable land while reducing negative environmental impact. On-farm data were evaluated to assess energy balance and greenhouse gas (GHG) emissions of irrigated maize in Nebraska that received large nitrogen (N) fertilizer (183 kg of N⋅ha−1) and irrigation water inputs (272 mm or 2,720 m3 ha−1). Although energy inputs (30 GJ⋅ha−1) were larger than those reported for US maize systems in previous studies, irrigated maize in central Nebraska achieved higher grain and net energy yields (13.2 Mg⋅ha−1 and 159 GJ⋅ha−1, respectively) and lower GHG-emission intensity (231 kg of CO2e⋅Mg−1 of grain). Greater input-use efficiencies, especially for N fertilizer, were responsible for better performance of these irrigated systems, compared with much lower-yielding, mostly rainfed maize systems in previous studies. Large variation in energy inputs and GHG emissions across irrigated fields in the present study resulted from differences in applied irrigation water amount and imbalances between applied N inputs and crop N demand, indicating potential to further improve environmental performance through better management of these inputs. Observed variation in N-use efficiency...

‣ Development of mathematical descriptions of mammalian cell culture kinetics for the optimization of fed-batch bioreactors

Glacken, Michael W. (Michael William)
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 236 leaves; 23821173 bytes; 23820932 bytes; application/pdf; application/pdf
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by Michael W. Glacken.; Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Applied Biological Sciences, 1987.; Bibliography: leaves 216-226.

‣ Fundamentals of biopolymer accumulation in immobilized acinetobacter calcoaceticus system

Wang, Sy-Dar
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 280 leaves; 15486694 bytes; 15486451 bytes; application/pdf; application/pdf
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by Sy-dar Wang.; Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Applied Biological Sciences, 1988.; Vita.; Bibliography: leaves 264-278.

‣ A recombinant DNA approach to the design and synthesis of novel polysaccharides

Easson, Donald Davidson, 1961-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 128 leaves; 6593604 bytes; 6593359 bytes; application/pdf; application/pdf
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by Donald Davidson Easson Jr.; Thesis (Sc. D.)--Massachusetts Institute of Technology, Dept. of Applied Biological Sciences, 1988.; Vita.; Bibliography: leaves 119-125.

‣ Pseudopoly(amino acids) : a study of the synthesis and characterization of polyesters made from α-L-amino acids

Yu, Heewon
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 220 [i.e. 231] leaves; 12708874 bytes; 12708632 bytes; application/pdf; application/pdf
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by Heewon Yu.; Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Applied Biological Sciences, 1988.; Vita.; Includes bibliographical references.

‣ Mutational spectra of MNNG and ICR-191 in human cells

Cariello, Neal Foster
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 2 v. ([1], 380 leaves); 29092938 bytes; 29092697 bytes; application/pdf; application/pdf
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by Neal Foster Cariello.; Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Applied Biological Sciences, 1988.; Includes bibliographical references.

‣ Purification and properties of heparinase from Flavobacterium heparinum

Zimmerman, Joseph James Francis
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 151 leaves; 10019322 bytes; 10019079 bytes; application/pdf; application/pdf
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by Joseph James Francis Zimmerman.; Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Applied Biological Sciences, 1988.; Title as it appeared in M.I.T. Graduate List September 1988: Heparin degrading enzymes from Flavobacterium heparinum.; Includes bibliographical references.

‣ DNA technology for Corynebacterium glutamicum : isolation and characterization of amino acid biosynthetic genes

Follettie, Maximillian Todd
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 186 leaves; 12901076 bytes; 12900834 bytes; application/pdf; application/pdf
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by Maximillian Todd Follettie.; Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Applied Biological Sciences, 1989.; Includes bibliographical references (leaves 168-186).

‣ Studies on cell disruption and cell debris removal in downstream bioprocessing

Sánchez-Ruiz, Sergio A
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 182 leaves; 11205711 bytes; 11205469 bytes; application/pdf; application/pdf
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by Sergio A. Sanchez-Ruiz.; Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Applied Biological Sciences, 1989.; Includes bibliographical references (leaves 176-181).

‣ P- and S- wave tomography of the crust and uppermost mantle in China and surrounding areas; P-wave and S-wave tomography of the crust and uppermost mantle in China and surrounding areas

Sun, Youshun, 1970-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 314 leaves; 73002625 bytes; 73004015 bytes; application/pdf; application/pdf
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This thesis involves inverting the seismic structure of the crust and uppermost mantle in China from the P- and S-wave travel-time tomography. The main contributions of this research are: 1) introducing the adaptive moving window method to obtain 2338 1D P and S models in China; 2) introducing a tomographic method to perform the 3D body wave travel-time tomography with the Moho discontinuity included. Both horizontal and vertical resolutions are highly controlled and smooth transitions among adjacent locations are guaranteed in the final models. To achieve these objectives, the Monte-Carlo (random search) method and the Gauss-Newton method are applied iteratively to find the nonlinear least square solutions and to optimize the models in the crust and uppermost mantle. The models we obtained provide accurate travel-time calculation, ground-truth event relocation and seismogram fittings. These models can therefore be applied to reliable earthquake location. Geological, geodynamic, and volcanic implications of our models are discussed in this thesis. Our tomographic models provide new insights into the geological structure and tectonics of the region, such as lithological variations and large fault zones across the major geological terranes.; (cont.) Compared with previous tomographic studies...

‣ Non invasive brain stimulation : modeling and experimental analysis of transcranial magnetic stimulations and transcranial DC stimulation as a modality for neuropathology treatment; TMS stimulations and tDCS as a modality for neuropathology treatment

Wagner, Timothy A. (Timothy Andrew), 1974-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 301 p.
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This thesis will explore the use of Transcranial Magnetic Stimulation (TMS) and Transcranial DC Stimulation (tDCS) as modalities for neuropathology treatment by means of both experimental and modeling paradigms. The first and primary modality that will be analyzed is Transcranial Magnetic Stimulation (TMS). TMS is a technique that uses the principle of electromagnetic induction to focus induced currents in the brain and modulate cortical function. These currents can be of sufficient magnitude to depolarize neurons, and when these currents are applied repetitively (repetitive Transcranial Magnetic Stimulation (rTMS)) they can modulate cortical excitability, decreasing or increasing it, depending on the parameters of stimulation. This thesis will explore important facets of the electromagnetic field distributions and fundamental electromagnetic interactions to lay the foundation for future development of a more complete neural model and improved stimulation techniques. First, TMS will be analyzed as a technique used in normal healthy subjects. Finite element modeling (FEM) studies will be explored for realistic healthy human head models with a particular focus placed on the TMS induced cortical currents and their dependency on coil position...

‣ Activity recognition with end-user sensor installation in the home

Rockinson, Randy Joseph
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 2 v. (253 leaves)
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In this work, a system for recognizing activities in the home setting that uses a set of small and simple state-change sensors, machine learning algorithms, and electronic experience sampling is introduced. The sensors are designed to be "tape on and forget" devices that can be quickly and ubiquitously installed in home environments. The proposed sensing system presents an alternative to sensors that are sometimes perceived as invasive, such as cameras and microphones. Since temporal information is an important component of activities, a new algorithm for recognizing activities that extends the naive Bayes classifier to incorporate low-order temporal relationships was created. Unlike prior work, the system was deployed in multiple residential environments with non-researcher occupants. Preliminary results show that it is possible to recognize activities of interest to medical professionals such as toileting, bathing, and grooming with detection accuracies ranging from 25% to 89% depending on the evaluation criteria used. Although these preliminary results were based on small datasets collected over a two-week period of time, techniques have been developed that could be applied in future studies and at special facilities to study human behavior such as the MIT Placelab. The system can be easily retrofitted in existing home environments with no major modifications or damage and can be used to enable IT and health researchers to study behavior in the home. Activity recognition is increasingly applied not only in home-based proactive and preventive healthcare applications...

‣ Multiscale determination of in situ stress and fracture properties in reservoirs

Grandi Karam, Samantha, 1973-
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 299 p.
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In this thesis we address the problem of determining in situ stress and fracture properties in reservoirs using borehole logs and surface seismic reflection data. The dissertation covers four subtopics. The first is the determination of horizontal stress magnitudes from measurements in a borehole. Two types of data used are stress-induced rock failures in the borehole, known as "breakouts," and the dispersions of polarized flexural waves which propagate along the borehole. Traditionally these data are analyzed to derive stress orientations but not magnitudes. To determine the magnitude of stresses directly from breakouts, we use an iterative elastic modeling of stresses around the borehole and Mohr-Coulomb failure criterion to match the borehole deformation. As a second method we use dispersion curves of the two polarized flexural waves and their crossover points. These methods are applied to data from a well in northeastern Venezuela. The combination of these two techniques provides a complete profile of stress as a function of depth since the first method is applied at the breakout depths and the second is applied everywhere else in the borehole. Both borehole methods agree in the estimation of stress orientation and magnitude. The maximum horizontal stress is in the NNW-SSE direction...

‣ Non-invasive detection of oral cancer using reflectance and fluorescence spectroscopy

McGee, Sasha Alanda
Fonte: Massachusetts Institute of Technology Publicador: Massachusetts Institute of Technology
Tipo: Tese de Doutorado Formato: 186 p.
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In vivo reflectance and fluorescence spectra were collected from patients with oral lesions, as well as healthy volunteers, in order to evaluate the potential of spectroscopy to serve as a non-invasive tool for the detection oral cancer. A total of 710 spectra were analyzed from 79 healthy volunteers, and 87 spectra from 67 patients. Physical models were applied to the measured spectral data in order to extract quantitative parameters relating to the structural and biochemical properties of the tissue. Data collected from healthy volunteers were used to characterize the relationship between the spectral parameters and tissue anatomy. Diagnostic algorithms for distinguishing various lesion categories were then developed using data collected from patients. The healthy volunteer study demonstrated that tissue anatomy has a strong influence on the spectral parameters. Anatomic sites could be easily distinguished from each other despite the apparent overlap in their parameter distributions. In particular, keratinized sites (gingiva and hard palate) were significantly distinct from other anatomic sites. The results of this study provide strong evidence that a robust and accurate spectroscopic based diagnostic algorithm for oral cancer needs to be applied in a site specific manner. Spectral diagnostic algorithms were developed using the data collected from patients...

‣ Development and Evaluation of Approaches for Quantitative Optical Molecular Imaging of Neoplasia

Rosbach, Kelsey Jane
Fonte: Universidade Rice Publicador: Universidade Rice
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This thesis develops and evaluates three approaches for quantitative molecularly-targeted optical imaging of neoplasia. The first approach focuses on widefield imaging of biomarkers near the tissue surface for early detection applications; this approach is demonstrated in freshly resected oral tissue. Most oral cancers are not detected until the disease has spread, but topical application of targeted imaging agents allows rapid visualization of biomarker expression, giving real-time, objective information. Epidermal growth factor receptor (EGFR) expression was quantified in patient samples using fluorescent epidermal growth factor. Dysplasia (n=4) and cancer (n=13) had an average 2.3-fold and 3.8-fold increase in signal compared to normal tissue. EGFR expression was assessed along with metabolic activity using a fluorescent glucose analog, 2-NBDG, in 9 patient samples. A classification algorithm using quantitative image features resulted in an area under the curve (AUC) of 0.83, though the main advantage of this technique may be to understand spatial heterogeneity of biomarker expression and how this correlates with disease. The next approach focuses on high-resolution optical imaging through a needle to detect metastases in lymphoid tissue for clinical staging applications; this approach is demonstrated in resected lymph nodes from breast cancer patients. These patients often require removal of nodes...

‣ Aprendizagem centrada no participante ou no professor? Um estudo comparativo em Administração de Materiais; Participant or professor centered learning? A comparative study in Applied Social Sciences

HAZOFF JÚNIOR, Waldemar; SAUAIA, Antonio Carlos Aidar
Fonte: Associação Nacional dos Programas de Pós-graduação em Administração Publicador: Associação Nacional dos Programas de Pós-graduação em Administração
Tipo: Artigo de Revista Científica
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A carga quantitativa presente em disciplinas de Administração tem provocado desconforto nos alunos que buscavam conteúdos humanistas, ao optarem pelas Ciências Sociais Aplicadas. O desconforto se agrava ainda mais quando a disciplina é oferecida às sextas-feiras no período noturno, comprometendo-se a aprendizagem. Formatou-se um estudo com quatro turmas de alunos (matutino e noturno) em duas instituições privadas, onde a disciplina Administração de Materiais e Bens Patrimoniais foi ministrada segundo dois procedimentos: P1 centrado no professor e P2 centrado nos alunos. Ambos fizeram uso das mesmas atividades encadeadas de maneira distinta, alternando-se aulas expositivas centradas no professor, exercícios centrados nos alunos e testes objetivos para avaliação de desempenho. O tratamento estatístico dos dados comprovou efeitos significativamente distintos nos procedimentos adotados, com desempenho superior (significância de 1%) na abordagem centrada nos alunos em ambas as instituições (IES). Conclui-se que além da atitude positiva e determinada do docente, a simples escolha de um procedimento menos centrado no professor e mais orientado para os alunos pode aumentar a eficiência do processo educacional, sem que sejam necessários gastos adicionais.; The quantitative approach in the Business courses has distressed students searching for humanistic contents in Applied Social Sciences area of knowledge. One can observe this in the Materials and Patrimonial Properties Management course taught during the Business Administration program. This situation becomes still worse when the course is offered on Fridays evenings. This study dealt with four classes (morning and evening sessions) in two private institutions. The course was taught according to two procedures: a) professor centered...

‣ Dynamics of coupled Josephson junctions under the influence of applied fields

Nayak, Chitra R; Kuriakose, V C
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
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We investigate the effect of the phase difference of applied fields on the dynamics of mutually coupled Josephson junction. The system desynchronizes for any value of applied phase difference and the dynamics even changes from chaotic to periodic motion for some values of applied phase difference. We report that by keeping the value of phase difference as $\pi$, the system continues to be in periodic motion for a wide range of system parameter values which might be of great practical applications.; Comment: 13 pages 13 figures

‣ Karl Popper’s model under the perspective of the applied social sciences; O modelo de Karl Popper sob a ótica das Ciências Sociais Aplicadas

Campanario, Milton de Abreu; Chagas Junior, Milton de Freitas; Ruiz, Mauro Silva
Fonte: Universidade Federal de Santa Catarina Publicador: Universidade Federal de Santa Catarina
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; ; Formato: application/pdf
Publicado em 26/04/2012 Português
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DOI: http://dx.doi.org/10.5007/2175-8077.2012v14n32p124Karl Popper is the leading philosopher of science in modern times, competing with Thomas Kuhn’s interpretation to the primacy of how to utilize de scientific method. Clearly, there are different versions for a reading of this important author who coined the method called deductive with test. This text recognizes the relevance of Karl Popper’s view of science as a practice in hard and biological fields, where it is widely accepted. However, this popularity is not shared in the applied social sciences area. This is an essay to rescue his contribution in an attempt to translate the concepts he developed in a didactic way. To this end, there will be an introduction to the fundamentals of science as specific form o knowledge, seeking to contrast the deductive and inductive approaches and procedures of what is known as formal science, basic and applied. An attempt to classify the formulation of theoretical propositions is undertaken with the use of different criteria, taking examples in the field of management and economics as an illustration.; DOI: http://dx.doi.org/10.5007/2175-8077.2012v14n32p124Karl Popper é o principal filósofo da ciência na modernidade, disputando com Thomas Kuhn a primazia de interpretação do método científico. Claramente há diferentes visões para uma leitura desse importante autor que cunhou o método chamado de dedutivo com teste. O texto reconhece a relevância da visão de Karl Popperno desenvolvimento de trabalhos científicos das ciências exatas e biológicas...