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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
101

J Psi Measurement in Au+Au Collisions at sqrt (sNN) = 39 and 62.4 GeV

Sen, Abhisek 26 November 2012 (has links)
J/psi production is considered a very important probes for studying the properties of quark-gluon plasma (QGP). At the PHENIX experiment at Brookhaven National Laboratory, a large suppression of J/psi production in Au+Au collisions at 200 GeV center of mass energy as compared to the binary collision scaled p+p collisions was observed. The level of suppression is similar to that observed at other energies at CERN's SPS and LHC experiments. This work addresses the PHENIX J/psi measurements at sqrt{s_{NN}}= 39 and 62 GeV Au+Au collisions. These allow for the energy dependent J/psi suppression measurements in order to disentangle the important contributing factors of J/psi production. J/psi results over a wide range of center of mass energies (39-200 GeV) from PHENIX are discussed, in addition to a comprehensive comparison with other experiments.
102

Social learning and action understanding in human observers: contributions of sensori-motor constraints and prior information / Apprendimento sociale e comprensione delle azioni in osservatori umani: contributi dei vincoli sensori-motori e dell'informazione a priori

Jacquet, Pierre Olivier <1980> 04 July 2012 (has links)
The aim of this thesis was to investigate the respective contribution of prior information and sensorimotor constraints to action understanding, and to estimate their consequences on the evolution of human social learning. Even though a huge amount of literature is dedicated to the study of action understanding and its role in social learning, these issues are still largely debated. Here, I critically describe two main perspectives. The first perspective interprets faithful social learning as an outcome of a fine-grained representation of others’ actions and intentions that requires sophisticated socio-cognitive skills. In contrast, the second perspective highlights the role of simpler decision heuristics, the recruitment of which is determined by individual and ecological constraints. The present thesis aims to show, through four experimental works, that these two contributions are not mutually exclusive. A first study investigates the role of the inferior frontal cortex (IFC), the anterior intraparietal area (AIP) and the primary somatosensory cortex (S1) in the recognition of other people’s actions, using a transcranial magnetic stimulation adaptation paradigm (TMSA). The second work studies whether, and how, higher-order and lower-order prior information (acquired from the probabilistic sampling of past events vs. derived from an estimation of biomechanical constraints of observed actions) interacts during the prediction of other people’s intentions. Using a single-pulse TMS procedure, the third study investigates whether the interaction between these two classes of priors modulates the motor system activity. The fourth study tests the extent to which behavioral and ecological constraints influence the emergence of faithful social learning strategies at a population level. The collected data contribute to elucidate how higher-order and lower-order prior expectations interact during action prediction, and clarify the neural mechanisms underlying such interaction. Finally, these works provide/open promising perspectives for a better understanding of social learning, with possible extensions to animal models. / L’obbiettivo della presente tesi consiste nell’esaminare il contributo dell’informazione a priori e dei vincoli sensorimotori per la comprensione delle azioni altrui, e nello stimare le loro conseguenze sull’evoluzione del apprendimento sociale. Nonostante allo studio della comprensione dell’azione e al suo ruolo nell’ apprendimento sociale sia dedicata un’ampia letteratura, queste problematiche rimangono molto dibattute. Nella tesi illustro due prospettive. La prima interpreta l’apprendimento sociale di alto livello come il prodotto di una rappresentazione a grana fine delle azioni e intenzioni altrui che richiede sofisticate abilità socio-cognitive. La seconda prospettiva sottolinea il ruolo di euristiche decisionali più semplici, il cui reclutamento è determinato da vincoli individuali ed ecologici. Attraverso quattro lavori sperimentali, viene dimostrato che questi due contributi non sono mutuamente esclusivi. Un primo studio esamina il ruolo della corteccia frontale inferiore (IFC), dell’area intraparietale anteriore (AIP) e della corteccia somatosensoriale primaria (S1) nel riconoscimento delle azioni, usando un paradigma di transcranial magnetic stimulation adaptation (TMSA). Il secondo lavoro studia se, e come, informazioni a priori di ordine superiore (acquisite dal campionamento probabilistico di eventi passati) e inferiore (derivate dalla stima degli impedimenti biomecanicci legati alle azione osservate) interagiscono durante la predizione delle intenzioni altrui. Usando una procedura di single-pulse TMS, il terzo lavoro esamina se l’interazione fra queste due classi di informazioni a priori modula l’attività del sistema motorio. Il quarto studio testa l’ampiezza con cui vincoli comportamentali ed ecologici possono influenzare, a livello popolazionale, la comparsa di strategie d’apprendimento sociale di grana fine. I dati raccolti contribuiscono a delucidare come le aspettative a priori di ordine superiore e inferiore interagiscano durante la predizione dell’azione, e chiarificano i meccanismi neurali sottostanti questa interazione. Infine, questi lavori aprono prospettive promettenti per una migliore comprensione dell’apprendimento sociale umano, con possibile estensioni ai modelli animali.
103

Development, degeneration and neural network of the bodily self

Gessaroli, Erica <1983> 28 April 2014 (has links)
The question addressed by this dissertation is how the human brain builds a coherent representation of the body, and how this representation is used to recognize its own body. Recent approaches by neuroimaging and TMS revealed hints for a distinct brain representation of human body, as compared with other stimulus categories. Neuropsychological studies demonstrated that body-parts and self body-parts recognition are separate processes sub-served by two different, even if possibly overlapping, networks within the brain. Bodily self-recognition is one aspect of our ability to distinguish between self and others and the self/other distinction is a crucial aspect of social behaviour. This is the reason why I have conducted a series of experiment on subjects with everyday difficulties in social and emotional behaviour, such as patients with autism spectrum disorders (ASD) and patients with Parkinson’s disease (PD). More specifically, I studied the implicit self body/face recognition (Chapter 6) and the influence of emotional body postures on bodily self-processing in TD children as well as in ASD children (Chapter 7). I found that the bodily self-recognition is present in TD and in ASD children and that emotional body postures modulate self and others’ body processing. Subsequently, I compared implicit and explicit bodily self-recognition in a neuro-degenerative pathology, such as in PD patients, and I found a selective deficit in implicit but not in explicit self-recognition (Chapter 8). This finding suggests that implicit and explicit bodily self-recognition are separate processes subtended by different mechanisms that can be selectively impaired. If the bodily self is crucial for self/other distinction, the space around the body (personal space) represents the space of interaction and communication with others. When, I studied this space in autism, I found that personal space regulation is impaired in ASD children (Chapter 9).
104

Determinants of Yeast Prion Stability

Davies, Linda Emily 24 February 2009 (has links)
S. cerevisiae Sup35p inhabits two metastable states: functional translation termination factor; and prion-like aggregate [PSI+], which propagates by converting soluble Sup35p to its own misfolded form. Once initiated, Sup35p polymerization in [PSI+] cells is spontaneous, but [PSI+] prion inheritance depends on the Hsp104p disaggregase. To identify Hsp104-interacting sequences, Sup35p was subjected to a systematic deletion screen. [PSI+] maintenance by mutant Sup35p was assessed in both presence and absence of plasmid-encoded WT Sup35p in haploid sup35 cells. Large deletions abolished [PSI+], implying perturbations of prion structure, while others imparted [PSI+]-dependent toxicity. Removal of a single 25aa segment destabilised [PSI+] inheritance, resulting in enhanced rates of prion loss. This is consistent with the expected prion propagation defect in response to reduced Hsp104p interaction. However, several mutants containing this 25aa segment share the destabilised prion phenotype, suggesting chaperone/prion interactions are strongly context-dependent, and no one Sup35p region is solely responsible for Hsp104p recognition.
105

Determinants of Yeast Prion Stability

Davies, Linda Emily 24 February 2009 (has links)
S. cerevisiae Sup35p inhabits two metastable states: functional translation termination factor; and prion-like aggregate [PSI+], which propagates by converting soluble Sup35p to its own misfolded form. Once initiated, Sup35p polymerization in [PSI+] cells is spontaneous, but [PSI+] prion inheritance depends on the Hsp104p disaggregase. To identify Hsp104-interacting sequences, Sup35p was subjected to a systematic deletion screen. [PSI+] maintenance by mutant Sup35p was assessed in both presence and absence of plasmid-encoded WT Sup35p in haploid sup35 cells. Large deletions abolished [PSI+], implying perturbations of prion structure, while others imparted [PSI+]-dependent toxicity. Removal of a single 25aa segment destabilised [PSI+] inheritance, resulting in enhanced rates of prion loss. This is consistent with the expected prion propagation defect in response to reduced Hsp104p interaction. However, several mutants containing this 25aa segment share the destabilised prion phenotype, suggesting chaperone/prion interactions are strongly context-dependent, and no one Sup35p region is solely responsible for Hsp104p recognition.
106

Formationszeiteffekte in der Produktion von Charmonia in Proton-Kern Kollisionen

Koudela, Daniela, January 2002 (has links)
Heidelberg, Univ., Diplomarb., 2002.
107

Individuální lidský pach jako kriminalistická stopa vytvořená kontaktním nebo bezkontaktním přenosem a jeho odolnost vůči fyzikálním vlivům / Individual human odor as a forensic trail in criminal proceeding made by contact or contactless transmission and its resistance to physical agents

Santariová, Milena January 2016 (has links)
The dissertation thesis consists of four papers that have been published in scientific journals. Study n. 1 The need to recover evidence from water is quite common in criminal investigation. The article deals with the possibility to collect human scent from such objects and with the ability of specially trained dogs to match such scent samples with scent samples collected from detained suspects. During an experiment, designed as a blind one, it has been proved, that human scent can survive on submerged objects and can be later used for scent identification. Study n. 2 To collect odors the Czech Republic Police use special fabric sorbents manufactured under the registered mark ARATEX. Before use the fabric sorbent is treated by water vapor sterilization. After the scent identification the sorbent is destroyed. The goal of the study was to verify if the vapor sterilization is effective enough to remove human scent that has already penetrated into the sorbent structure or in other words if the sorbent can be exposed to vapor sterilization and then used again. Specially trained dogs were used to match starting odors with target odors in the line-ups. The results showed that dogs are able to correctly match human odors even after they have being exposed to vapor sterilization. Study n. 3 The purpose of the study was to determine the temperature at which the human scent is degraded so that a dog would not be able to identify it. In contrast to expectations, eight dogs used in the experiment almost flawlessly identified human scents from five scent donors exposed to temperatures of 100°C, 200°C, 300°C, 400°C, 500°C, 600°C, 700°C, and 800°C. Only two of the dogs were able to identify 5 of 15 scent samples exposed to 900°C. No dog identified a scent exposed to 1000°C. Our study verified heat survivability of human scent far beyond existing expectations. Study n. 4 We tested the hypothesis that if odor fallout (the release of a human odor onto an untouched object) in human subjects exists, then holding a hand above an absorbent will produce a detectable scent which will be subsequently matched in a detection test by trained dogs. Scents were collected from seven males to sterile cotton absorbent squares. The left hand was used to get the control scent and the right hand served as the target scent. Each experimental subject was sitting and his left hand was laid down on a cotton square for 3 min. The right hand was held 5 cm above another cotton square for 3 min. The scent identification was done by two specially trained police German shepherds. Both dogs performed 14 line-ups and correctly matched the collected scents of all test subjects. The results suggest the existence of human odor fallout, whereby a human scent trace is left by humans even if they do not touch an object.
108

The regulatory role of cyanobacterial High light inducible proteins

SHUKLA, Mahendra Kumar January 2018 (has links)
The aim of the thesis was to elucidate the role of High light inducible proteins (Hlips) in the protection/regulation of the biogenesis of photosynthesis machinery. During the project two Hlip proteins (HliC and HliD) were isolated from the cyanobacterium Synechocystis PCC 6803; either as a pure oligomer (HliC protein) or as a small complex with a putative Photosystem II assembly factor Ycf39 (HliD protein). Pigments bound to purified Hlips were analyzed by state-of-art spectroscopic techniques to elucidate the mechanism of thermal energy dissipation. In addition, this work explained the mechanism of how the HliC protein regulates the interaction between chlorophyll synthase enzyme and the Ycf39 protein. This conceptually new mechanism is based on the replacement of HliD dimers in chlorophyll synthase complexes by stress-induced HliD-HliC heterodimers, which changes the affinity of Ycf39 towards chlorophyll synthase.
109

Desenvolvimento de novas metodologias PSI-MS para bioanálises / Development of new PSI-MS methodologies for bioanalysis

Fernandes, Aline Rosa 02 April 2018 (has links)
Submitted by Franciele Moreira (francielemoreyra@gmail.com) on 2018-05-28T17:55:37Z No. of bitstreams: 2 Dissertação - Aline Rosa Fernandes - 2018.pdf: 2708071 bytes, checksum: 09cf08ef257f815da8d21193826fc32f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-05-29T11:24:27Z (GMT) No. of bitstreams: 2 Dissertação - Aline Rosa Fernandes - 2018.pdf: 2708071 bytes, checksum: 09cf08ef257f815da8d21193826fc32f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-05-29T11:24:27Z (GMT). No. of bitstreams: 2 Dissertação - Aline Rosa Fernandes - 2018.pdf: 2708071 bytes, checksum: 09cf08ef257f815da8d21193826fc32f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2018-04-02 / Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Paper spray ionization (PSI) is an environmental ionization technique in mass spectrometry (MS), where the sample is deposited on triangular paper moistened with solvent and the ionization process occurs by the application of high voltage on the paper. An important factor that can affect its performance is ion suppression. Aiming to reduce this effect and the exclusion of macromolecules in complex samples, the RAM-PSI-MS method for the analysis of dopamine and epinephrine in plasma was developed and validated. A methodology for analyzing creatinine in the urine was also developed using graphene oxide (GO) modified paper. The methods developed were efficient and promising in improving the role for PSI-MS analysis. The graphene oxide coating was able to improve the time and stability of the spray, in addition to reducing the effect of ion suppression. Already coating the paper with ISRP-RAM phase made it possible to analyze a complex sample, such as plasma, without any sample preparation, obtaining very satisfactory results. Showing that it is possible, practically, to eliminate the inherent problems of PSI-MS, only with the paper coating. / Paper spray ionization (PSI) é uma técnica de ionização ambiente em espectrometria de massas (MS), onde a amostra é depositada sobre papel triangular umedecido com solvente e o processo de ionização ocorre pela aplicação de alta voltagem no papel. Um importante fator que pode afetar seu desempenho é a supressão iônica. Visando a diminuição desse efeito e a exclusão de macromoléculas em amostras complexas foi desenvolvido e validado o método RAM-PSI- MS para analise de dopamina e epinefrina em plasma. Foi também desenvolvida uma metodologia para análise de creatinina na urina utilizando um papel modificado com óxido de grafeno (GO). Os métodos desenvolvidos foram eficientes e promissores na melhora do papel para analises de PSI-MS. O revestimento com óxido de grafeno foi capaz de melhorar o tempo e a estabilidade do spray, além de diminuir o efeito de supressão iônica. Já revestindo o papel com fase ISRP-RAM tornou possível analisar uma amostra complexa, como o plasma, sem nenhum preparo de amostra, obtendo resultados bastante satisfatórios. Mostrando que possível, praticamente, eliminar os problemas inerentes do PSI-MS, apenas com o revestimento do papel.
110

LABORATORY CHARACTERIZATION OF COHESIVE SUBGRADE MATERIALS

Khasawneh, Mohammad Ali 23 September 2005 (has links)
No description available.

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