86,865 research outputs found
Conformational Stability of Neuroglobin Helix F: Possible Effects on the Folding Pathway within the Globin Family
No full textNeuroglobin is a recently discovered member of the globin family, mainly observed in neurons and retina. Despite the low sequence identity (less than 20% over the whole sequence for the human proteins), the general fold of neuroglobin closely resembles that of myoglobin. The latter is a paradigmatic protein for folding studies, whereas much less is known about the neuroglobin folding pathway. In this work, we show how the structural features of helix F in neuroglobin and myoglobin could represent a pivotal difference in their folding pathways. Former studies widely documented that myoglobin lacks helix F in the apo form. In this study, limited proteolysis experiments on aponeuroglobin showed that helix F does not undergo proteolytic cleavage, suggesting that, also in the apo form, this helix maintains a rigid and structured conformation. To understand better the structural properties of helices F in the two proteins, we analyzed peptides encompassing helix F of neuroglobin and myoglobin in the wild-type and mutant forms. NMR and CD experiments revealed a helical conformation for neuroglobin helix F peptide, at both pH 7 and pH 2, absent in the myoglobin peptide. In particular, NMR data suggest a secondary structure stabilization effect caused by hydrophobic interactions involving Tyr88, Leu89 and Leu92. Molecular dynamics simulations performed on the apo and holo forms of the two proteins reveal the persistence of helix F in neuroglobin even in the absence of heme. Conversely myoglobin shows a higher mobility of the N-terminus of helix F on heme removal, which leads to the loss of secondary structure
An architecture for task execution in adverse environments
No full textThis thesis describes an architecture for distributed computation in mobile environments. Here, the workflow stands for the operational aspect of a work procedure. This notion subsumes the structure of the tasks, who performs them, what their operation structure is, how they are synchronized, how information flows to support the tasks and how they are tracked. The designed architecture is tested in a proof-of-concept implementation named Distributed Workflow Execution Architecture for Mobile (DWEAM). The interest in distributed workflow execution architectures is long-standing. However, there has not yet been an adequate treatment of workflow execution in mobile systems. The benefits of such a system would be collected by users who perform a coordinated task in a complex environment and must establish own coordination infrastructure to do so. Typical users are the members of emergency rescue teams, i.e.~police, fire brigade or medical personnel, when handling an incident, where the cooperation between the team members is hindered by mobility and adverse communication conditions. The communication via the gsm networks, that are used in small scale operations in urban areas cannot offer appropriate quality of service in face of escalation or infrastructure damage. The now-aged broadcast radio (i.e. walkie-talkie) typically does not support the coupling with information systems, as it is is intended for the communication between humans. We therefore consider a system architecture that addresses the communication issues, while being infrastructure-independent and supporting both the work procedures for human operators, as well as that of the information systems. First, the DWEAM problem is put into a broader context of mixed-initiative multi-actor, multi-agent systems. It is seen that DWEAM is but a single component of a larger system, called combined. The unifying description of combined is given, and the requirements for the integrated combined system are given. Following this description, we give an overview and commentary of the related work. We describe the toolkit that is used in the subsequent chapters, which relies on the usage of the Object-Z language, and the process model of the cpn. We then formalize the task of DWEAM, and complete the description of the used framework by specifying the distributed blackboard. We then describe the method used to cast the informal descriptions of inter-related tasks into a cpn. The cpn description is then converted into an implementation using a distributed blackboard. Afterwards the description of the operating environment and the storage model is given. We investigate the connectivity function for a set of nodes in two dimensions. Having done that, we turn our attention to the storage model, where we estimate the performance of the data partitioning to achieve the token preservation. For data distribution, the notions of producers and consumers are introduced, and the Service Discovery Problem (SDP) is defined. The Core-Based Tree (CBT) is afterwards used to provide a solution to the SDP, by finding the producers and consumers which are compatible, i.e. those that communicate through the delivery of data objects. A detailed analysis of the CBT construction algorithm is given, with the cpn descriptions of its phases and the discussion about its performance. All the data distributed in the DWEAM system must conform to the Dataspace model. It then becomes possible to define the matching algorithm. In it, the CBT structure constructed earlier is used to compute the matching between the compatible producers and consumers. The proof of the matching algorithm is given, followed by the cpn description of the implementation. The thesis is concluded by the list of contributions, the explanation of the outlook of distributed workflow execution in the contemporary context, and gives pointers to future work.Electrical Engineering, Mathematics and Computer Scienc
Variations on the Author
No full text“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Conformational stability of Neuroglobin helix F: possible effects on the folding pathway within the globin family
No full text[Newspaper Clipping: Author Claims Evidence of Second JFK Assassin #1]
No full textNewspaper article titled "Author Claims Evidence of Second JFK Assassin." The article states that author Richard J. Whalen concluded "that there is circumstantial evidence to support the theory of a second assassin in the shooting of President John F. Kennedy.
Further constraints on the diagenetic influences and salinity effect on Globigerinoides ruber (white) Mg/Ca thermometry: Implications in the Mediterranean Sea
No full textWe analyzed Mg/Ca ratios of the planktonic species Globigerinoides ruber (white) picked from 49 box core samples covering the whole Mediterranean Sea and 2 core tops from the Atlantic Ocean. Over the entire data set, we found no significant correlation between Mg/Ca and delta(18)O-derived calcification temperatures. This lack of correlation is chiefly due to the presence of an early diagenetic, Mg-rich calcite coating, which can constitute up to 20% of the total shell calcite in the central and eastern Mediterranean basin and result in anomalously high Mg/Ca values and a high scattering. In the western Mediterranean Sea, however, G. ruber Mg/Ca scattering shows smaller amplitude and Mg-rich calcite remains under the XRD detection limit. SEM observations indicate that only a few samples are affected by trace amounts of post-mortem calcite overgrowths (most of this calcite being likely removed during the chemical cleaning for Mg/Ca analyses). Using core top sediments from the western Mediterranean Sea, we performed an empirical calibration exercise, which confirms that G. ruber Mg/Ca is not only related to temperature but it is also significantly affected by sea surface salinity. This salinity effect is not specific to high salinity environments such as the Mediterranean Sea, since it appears to be coherent with recent results obtained on Indo-Pacific and Atlantic surface sediments, which suggest that a +1 (psu) change in SSS results in a +1.7 degrees C Mg/Ca-temperature bias. This sensitivity to salinity is significantly higher than those deduced from culture experiments
Also By The Same Author: AKTiveAuthor, a Citation Graph Approach to Name Disambiguation
No full textThe desire for definitive data and the semantic web drive for inference over heterogeneous data sources requires co-reference resolution to be performed on those data. In particular, name disambiguation is required to allow accurate publication lists, citation counts and impact measures to be determined. This paper describes a graph-based approach to author disambiguation on large-scale citation networks. Using self-citation, co-authorship and document source analyses, AKTiveAuthor clusters papers, achieving precision of 0.997 and recall of 0.818 over a test group of eight surname clusters
John F. Kennedy telegram to Roosevelt
No full textJersey Homesteads (later the Borough of Roosevelt) was established in the 1930s as an agro-industrial cooperative community. It was established specifically for urban Jewish garment workers, many of whom had emigrated from Europe. President John F. Kennedy sent a telegram to the citizens of Roosevelt, New Jersey, apologizing for not being able to attend the memorial dedication in honor of former President Franklin Delano Roosevelt. (Jersey Homesteads became Roosevelt in 1945 in honor of the president.) President Kennedy expressed his gratitude to the people of Roosevelt for constructing the memorial, and commented that it will serve as a constant reminder of Roosevelt's good works
Logarithmic variance profiles and the corresponding f-1 spectra of temperature fluctuations in turbulent Rayleigh-Bénard convection
No full textWe report experimental results for the temperature variance 2(z) and the corresponding frequency spectra P(f) in turbulent Rayleigh-Bénard convection (RBC) in a cylindrical sample of aspect ratioT= D/L = 1:00 (D = 1:12 m is the diameter and L = 1:12 m the height). The measurements were conducted in the Rayleigh-number range 1011 < Ra < 1:35 1014 and Pr ' 0:8. For Ra = 1:35x1014, 2(z) could be described well by a logarithmic dependence on the vertical position z in a range of z 1 < z < z 2 with z 1 ' 70 and z 2 = 0:1L. Here L=(2Nu) is the thickness of a thin thermal sublayer adjacent to the horizontal plate where the heat flux (denoted by the Nusselt number Nu) is carried mostly by thermal diffusion. In the log layer, we found that the temperature spectra had a significant frequency range over which P(f) f with close to 1. As Ra decreased, increased so that the log layer became thinner. At Ra = 2:05 1011, z 2 < z 1 and therefore there was no range for a log layer. Correspondingly, the temperature spectrum near the horizontal plate did not have the f1 scaling form either
Maine author Franklin F. Gould recalls his first glimpse of the outside world
No full textMaine author Franklin F. Gould recalls his first glimpse of the outside world as he relates how, as a young farm boy in the late 1800\u27s, he drove his father\u27s horses on an errand to an icebound river
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