On the reaction mechanism of the chemical activation of Quercus Agrifolia char by alkaline hydroxides

Activation of Quercus Agrifolia char with NaOH and KOH using a rotary batch reactor is presented in this work. Several samples of activated carbon showing a very high degree of activation with predominance of microporosity were obtained. Nitrogen and argon were used as gaseous media in the activation procedure. Samples were evaluated using nitrogen adsorption applying BET and DR equation for porosity assessment. The existence of CN⁻ in activated samples suggests the occurrence of not previously reported chemical reactions in this process and could be an indication of the involvement of N₂ in the chemical reaction. Following these results, some additional chemical reactions are proposed as part of the reaction mechanism for MeOH-C-N₂ system.     

A highly stable polyethylene glycol-conjugated human single-chain antibody neutralizing granulocyte-macrophage colony stimulating factor at low nanomolar concentration

GM-CSF (granulocyte-macrophage colony stimulating factor) plays a central role in inflammatory processes. Treatment with antibodies neutralizing murine GM-CSF showed significant therapeutic effects in mouse models of inflammatory diseases. We constructed by phage display technology a human scFv, which could potently neutralize human GM-CSF. At first, a human V(L) repertoire was combined with the V(H) domain of a parental GM-CSF-neutralizing rat antibody. One dominant rat/human scFv clone was selected, neutralizing human GM-CSF with an IC50 of 7.3 nM. The human V(L) of this clone was then combined with a human V(H) repertoire. The latter preserved the CDR 3 of the parental rat V(H) domain to retain binding specificity. Several human scFvs were selected, which neutralized human GM-CSF at low nanomolar concentrations (IC50 > or = 2.6 nM). To increase serum half-life, a branched 40 kDa PEG-polymer was coupled to the most potent GM-CSF-neutralizing scFv (3077) via an additional C-terminal cysteine. PEG conjugation had a negligible effect on the in vitro neutralizing potential of the scFv, although it caused a significant drop in binding affinity owing to a reduced on-rate. It also significantly increased the stability of the scFv at elevated temperatures. In mouse experiments, the PEGylated scFv 3077 showed a significantly prolonged elimination half-life of 59 h as compared with 2 h for the unconjugated scFv version. PEGylated scFv 3077 is a potential candidate for development of a novel antibody therapy to treat pro-inflammatory human diseases.     

The GI-UEV Domain,a Catalytically Inactive Ubiquitin-Conjugating Enzyme Variant With a Role in Translational Regulation

Ubiquitin-conjugating enzymes (UBCs) form the second step in the enzyme cascade required for protein ubiquitylation. Most eukaryotic genomes contain a multitude of different catalytically active UBCs. In addition, several proteins contain homology domains related to UBCs that have lost their catalytic activity and are referred to as “ubiquitin-conjugating enzyme variants” or UEV-domains. A common property of those domains is a role in ubiquitin binding and recognition. We report here on a novel class of more distantly related UEV domains, which forms a superset of the previously described GI-homology region found in Gcn2 and IMPACT proteins. In the Gcn2 and IMPACT protein families, the GI-UEV domain binds to proteins of the Gcn1 family and thus regulates translation levels via eIF2α phosphorylation. Bioinformatical analysis shows that GI-UEV domains occur in a large number of proteins, many of them without an established role in translational regulation. Residue conservation and domain context predict that GI-UEV domains might also have a role in the ubiquitin/proteasome system, suggesting a possible cross-talk between ubiquitylation and translational regulation.     

Interstellar dust laser explorer: a new instrument for elemental and isotopic analysis and imaging of interstellar and interplanetary dust

We present the performance characteristics of a time-of-flight secondary ion mass spectrometer designed for 157 nm laser postionization of sputtered neutrals for high sensitivity elemental and isotopic analyses. The instrument was built with the aim of analyzing rare element abundances in micron to submicron samples such as interstellar grains and cometary dust. Relative sensitivity factors have been determined for secondary ion mass spectrometry which show an exponential dependency against the first ionization potential. This allows elemental abundances to be measured with errors below 25% for most major elements. The accuracy for isotope ratios, where isotopes can be resolved from isobaric interferences, is usually limited only by counting statistics. In laser secondary neutral mass spectrometry, the spatial and temporal overlaps between the laser and sputtered neutral atoms are modeled and predictions of total detection efficiency and isotopic and elemental fractionation are compared with experimental data. Relative sensitivity factors for laser-ionized secondary neutrals from a stainless steel standard are found to vary less than 3% above saturation laser pulse energy enabling more accurate quantification.     

Development and validation status of the IFMIF High Flux Test Module

The development of the IFMIF (International Fusion Material Irradiation Facility) High Flux Test Module in the EVEDA (Engineering Validation and Engineering Design Activities) phase up to 2013 includes conceptual design, engineering analyses, as well as design and engineering validation by building of prototypes and their testing. The High Flux Test Module is the device to facilitate the irradiation of SSTT samples of RAFM steels at temperatures 250–550 °C and up to an accumulated irradiation damage of 150 dpa. The requirements, the current design and the performance of the module are discussed, and the development process is outlined.     

Method for rapid testing of thermo-mechanical characteristics of solder joints

The creep behavior of alternative soft solder alloys is not, as a rule, well known. This characteristic is however very important for the prediction of a joint's long-term reliability. Conventional test methods are often impractical, slow and deliver only qualitative results. The new testing method presented is able to provide very fast quantitative values of thermo-mechanical characteristics. This paper shows latest results, comparison with standard testing, investigation of high temperature applications and new fields of use.     

Local perspectives in conservation politics: the case of the Ría Lagartos Biosphere Reserve, Yucatán, México

Local perspectives are presented on the conflicts and contradictions in the Ría Lagartos Biosphere Reserve, one of 10 priority reserve areas in México that receive financing from the World Bank and other development and conservation institutions. There are four villages into the reserve, whose total population ranges from 800 to 2500 inhabitants. At this reserve, decision-makers and administrators have focused on biological conservation, failing to understand the social and political relations of the local people, which are strongly affected by globalization and modern conservation policy. Modern conservation is a western discourse on nature, is a kind of “licence to conserve”, analogous to an automobile driver's licence. Conservation in Ría Lagartos means prohibition to the local population hence conflicts frequently arise between them and both local and federal authorities. However, there is an urgent need to move forward and recognise the diversity of discourses on nature that give rise to different kinds of knowledge and practices of conservation variously called popular, traditional, indigenous, and folk. This paper discusses the institutionalization of conservation in a natural protected area (biosphere reserve) in the northwest of Yucatán Peninsula. The researcher initially established rapport with the communities of this region more than 10 years ago, working on various ethnographic research projects from then to the present. This long-term relationship has (1) deepened the level of trust, (2) contributed substantially to the background knowledge critical for identifying local factors of importance, and (3) provided information necessary for the proper wording of questions in the local parlance. The research reported here continued to use the same ethnographic approach used in the former research projects, an ethnographic method including participant observation and informal interviews in homes, work places, local stores, and other places normally frequented by the local consultants. The research reported in this article was done from August 1996 to July 1997 in the three communities of the Biosphere Reserve of Ría Lagartos: Río Lagartos, San Felipe and Las Coloradas.     

A Second Failure to Replicate the Gottman et al. (1995) Typology of Men Who Abuse Intimate Partners...and Possible Reasons Why.

The present study attempts to replicate Gottman et al.'s (1995; see record 1995-44075-001; and Jacobson & Gottman, 1998) psychophysiological study that classifies partner assaultive men into two distinct groups: heart rate (HR) decelerators (Type 1 batterers) and HR accelerators (Type 2 batterers). Current results indicate no significant differences between Type 1 and Type 2 batterers on the antisocial spectrum of behaviors. Resting HR, rather than HR change, was negatively related to the antisocial spectrum of behavior for batterers with severe, clinical levels of violence only. Reasons for subsequent failures to replicate the Type 1 versus Type 2 distinctions may be attributable to unusually high autonomic arousal during baseline in the original study. Consideration of resting HR and the use of dimensional as opposed to categorical approaches in analyzing the heterogeneity of batterers are proposed as possible solutions to clarifying inconsistencies across laboratories. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive, social, motivational and health aspects of students in laptop classrooms

Effects on cognitive performance, social atmosphere, communication, motivation and aspects of strain were investigated when laptops were integrated in classrooms. According to a quasi‐experimental design 27 laptop students were compared with 22 non‐laptop students from the same high school, aged 17–18 years. Results of tests and questionnaires showed that laptop students had better spatial abilities and computer skills, furthermore higher participation, learning interest, motivation and pressure to perform were found in laptop classrooms. However, laptop students experienced greater physical discomfort, particularly in their arms, but concerning creativity, social intelligence and mental stress no group differences occurred. Results indicate that laptops integrated in teaching can enhance learning and motivation in schools, at least after 1.7 years of introduction, but health risks must be considered.