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Selected AbstractsThe organisation of invertebrate brains: cells, synapses and circuitsACTA ZOOLOGICA, Issue 1 2010Ian A. Meinertzhagen Abstract Meinertzhagen, I.A. 2010. The organisation of invertebrate brains: cells, synapses and circuits. ,Acta Zoologica (Stockholm) 91: 64,71 Invertebrate brains are structurally diverse. Neuron numbers range from ,102 to 108 in different groups, compared with larger numbers in vertebrate brains, ,107 to 1014. The underpopulated brains of invertebrates are noted in their extreme cases for having few cells, and neurons that can be identified from animal to animal, many known in great detail. Although few in number, invertebrate neurons nevertheless comprise many classes. Correlated with the paucity of their number they are sparsely connected, many having ,50 synapses or fewer. Synaptic densities, roughly 1 per ,m3 of neuropile, differ little from those for much larger vertebrate neurons. Invertebrate neurons differ from their vertebrate counterparts in the position of their soma, generally in a cortex surrounding the neuropile that consequently occupies a relatively small volume. Their axons typically lack myelin and, supporting a range of conduction velocities, have diameters that differ over a wide range, from 103 to 10,1,m. Nerves with thousands of axons differ from neuropile fascicles, which typically have 20 or less. Unlike most vertebrate synapses, but like those of the vertebrate retina, synapses in many invertebrate groups , probably all ecdysozoans and possibly some lophotrochozoans , have synaptic contacts with multiple postsynaptic elements, dyads, triads and so on. [source] Activation drives PD-1 expression during vaccine-specific proliferation and following lentiviral infection in macaquesEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 5 2008David Abstract Recent data supports that increased expression of PD-1, a negative regulator of immune function, is associated with T cell exhaustion during chronic viral infection. However, PD-1 expression during acute infection and vaccination has not been studied in great detail in primates. Here, we examine PD-1 expression on CD3+ T cells following DNA vaccination or lentiviral infection of macaques. Ex vivo peptide stimulation of PBMC from DNA-vaccinated uninfected macaques revealed a temporal increase in PD-1 expression in proliferating antigen-specific CD8+ T cells. Following the initial increase, PD-1 expression steadily declined as proliferation continued, with a concomitant increase in IFN-, secretion. Subsequent examination of PD-1 expression on T cells from uninfected and lentivirus-infected non-vaccinated macaques revealed a significant increase in PD-1 expression with lentiviral infection, consistent with previous reports. PD-1 expression was highest on cells with activated memory and effector phenotypes. Despite their decreased telomere length, PD-1hi T cell populations do not appear to have statistically significant uncapped telomeres, typically indicative of proliferative exhaustion, suggesting a different mechanistic regulation of proliferation by PD-1. Our data indicate that PD-1 expression is increased as a result of T cell activation during a primary immune response as well as during persistent immune activation in macaques. Supporting Information for this article is available at www.wiley-vch.de/contents/jc_2040/2008/37857_s.pdf [source] Microbial biodegradation of polyaromatic hydrocarbonsFEMS MICROBIOLOGY REVIEWS, Issue 6 2008Ri-He Peng Abstract Polycyclic aromatic hydrocarbons (PAHs) are widespread in various ecosystems and are pollutants of great concern due to their potential toxicity, mutagenicity and carcinogenicity. Because of their hydrophobic nature, most PAHs bind to particulates in soil and sediments, rendering them less available for biological uptake. Microbial degradation represents the major mechanism responsible for the ecological recovery of PAH-contaminated sites. The goal of this review is to provide an outline of the current knowledge of microbial PAH catabolism. In the past decade, the genetic regulation of the pathway involved in naphthalene degradation by different gram-negative and gram-positive bacteria was studied in great detail. Based on both genomic and proteomic data, a deeper understanding of some high-molecular-weight PAH degradation pathways in bacteria was provided. The ability of nonligninolytic and ligninolytic fungi to transform or metabolize PAH pollutants has received considerable attention, and the biochemical principles underlying the degradation of PAHs were examined. In addition, this review summarizes the information known about the biochemical processes that determine the fate of the individual components of PAH mixtures in polluted ecosystems. A deeper understanding of the microorganism-mediated mechanisms of catalysis of PAHs will facilitate the development of new methods to enhance the bioremediation of PAH-contaminated sites. [source] Charles Darwin, ichthyology and the species conceptFISH AND FISHERIES, Issue 3 2002Daniel Pauly Abstract This contribution presents the ichthyological writings of Charles Darwin (1809,1882), by periods, viz. ,the years prior to the voyage of the Beagle' (about 1825,1830); ,the Beagle years' (1831,1836); ,from the return of the Beagle to the Foundation of Origin' (1837,1844); and ,the mature Darwin' (1845,1882). Overall, this material covers 45 000 words penned by Darwin, but represents only 0.7% of his lifetime output of about 6 million words, indicating a limited interest in fish. However, this sample, briefly described here, but analysed in great detail in a forthcoming volume on Darwin's Fishes, allows drawing inferences on Darwin's working style that were missed in conventional biographies. On the other hand, it is suggested, based on a close reading of the 6th (1876) edition of Origin, that Darwin was not particularly interested in the theoretical issues now associated with the species concept, nor indeed with other levels of the Linnean system. [source] Aspects of stability and phenomenology in type IIA orientifolds with intersecting D6-branesFORTSCHRITTE DER PHYSIK/PROGRESS OF PHYSICS, Issue 1 2004T. OttArticle first published online: 14 JAN 200 Abstract Intersecting branes have been the subject of an elaborate string model building for several years. After a general introduction into string theory, this work introduces in detail the toroidal and -orientifolds. The picture involving D9-branes with B-fluxes is shortly reviewed, but the main discussion employs the T-dual picture of intersecting D6-branes. The derivation of the R-R and NS-NS tadpole cancellation conditions in the conformal field theory is shown in great detail. Various aspects of the open and closed chiral and non-chiral massless spectrum are discussed, involving spacetime anomalies and the generalized Green-Schwarz mechanism. An introduction into possible gauge breaking mechanisms is given, too. Afterwards, both ,, = 1 supersymmetric and non-supersymmetric approaches to low energy model building are treated. Firstly, the problem of complex structure instabilities in toroidal ,R -orientifolds is approached by a -orbifolded model. In particular, a stable non-supersymmetric standard-like model with three fermion generations is discussed. This model features the standard model gauge groups at the same time as having a massless hypercharge, but possessing an additional global B - L symmetry. The electroweak Higgs mechanism and the Yukawa couplings are not realized in the usual way. It is shown that this model descends naturally from a flipped SU(5) GUT model, where the string scale has to be at least of the order of the GUT scale. Secondly, supersymmetric models on the -orbifold are discussed, involving exceptional 3-cycles and the explicit construction of fractional D-branes. A three generation Pati-Salam model is constructed as a particular example, where several brane recombination mechanisms are used, yielding non-flat and non-factorizable branes. This model even can be broken down to a MSSM-like model with a massless hypercharge. Finally, the possibility that unstable closed and open string moduli could have played the role of the inflaton in the evolution of the universe is being explored. In the closed string sector, the important slow-rolling requirement can only be fulfilled for very specific cases, where some moduli are frozen and a special choice of coordinates is taken. In the open string sector, inflation does not seem to be possible at all. [source] HR's new ROI: Return on intangiblesHUMAN RESOURCE MANAGEMENT, Issue 2 2005Dave Ulrich A new human resource ROI has been identified: return on intangibles. Intangibles represent the hidden value of a firm and are becoming an increasingly important portion of a firm's total market capitalization. Six actions that HR professionals can take to create sustainable intangible value are presented in great detail. The emerging focus on intangibles opens the way for HR professionals to more readily link their work to shareholder value. © 2005 Wiley Periodicals, Inc. [source] Basic Process Capability Indices: An Expository ReviewINTERNATIONAL STATISTICAL REVIEW, Issue 3 2008Mohammed Z. Anis Summary A review of the four basic process capability indices has been made. The interrelationship among these indices has been highlighted. Attention has been drawn to their drawbacks. The relation of these indices to the proportion nonconforming has been dwelt upon and the requirement of the adequate sample size has been emphasized. Cautionary remarks on the use of these indices in the case of nonnormal distributions, skewed distributions, and autocorrelated data are also presented. The effect of measurement error on process capability indices has been dealt with in great detail. Résumé Une revue des quatre index de capacité de procédé fondamentaux a été faite. L'inter-relation entre ces index a été soulignée. L'attention a été dessinée à leurs inconvénients. La relation de ces index au nonconformer de proportion a été demeurée sur et la condition de la taille d'échantillon suffisante a été soulignée. Les remarques d'avertissement sur l'usage de ces index dans le cas de distributions nonnormaux, les distributions déformés et les données d'auto-correspondu sont aussi présentés. L'effet d'erreur de mesure sur les index de capacité de procédé a été traité dans les moindres détails. [source] Searching for Neuroglobin's role in the brainIUBMB LIFE, Issue 8-9 2007Karin Nienhaus Abstract Neuroglobin is a small globin that plays an important role in the protection of brain neurons from ischemic and hypoxic injuries. The molecular mechanisms by which Ngb performs its physiological function are still under debate. Suggestions include oxygen storage and delivery, scavenging of NO and/or reactive oxygen species, oxygen sensing and signal transduction. In recent years, the molecular structures of Ngb with carbon monoxide bound to the heme iron and without an exogenous ligand have been solved, and interesting structural changes have been noticed upon ligand binding. Moreover, equilibrium and kinetic properties of the reactions with ligands have been examined in great detail. Here we summarize the molecular properties of Ngb and discuss them in relation to the potential physiological functions. [source] Dynamics of mucosal dimensions after root coverage with a bioresorbable membraneJOURNAL OF CLINICAL PERIODONTOLOGY, Issue 1 2000Hans-Peter Müller Abstract Background: So far, the clinical effects of the placement of a resorbable membrane for guided tissue regeneration have not been studied in humans in great detail. The dynamics of the resorptive processes, in particular, appear to be rather speculative. In the present longitudinal study, specific alterations of the dimensions of the dentogingival mucosa were explored after surgical root coverage by using a bioresorbable membrane and a coronally-repositioned flap. Methods: The study population consisted of 14 patients with a total of 31 predominantly shallow, Miller class I, II or III recessions. The thickness of the masticatory and lining mucosa before and after surgical intervention was measured with an ultrasonic device. Results: Mean (±sd) recession depth and width were 2.85±1.29 and 4.46±1.14 mm, respectively. After 12 months, 51±29% of the recession depth (p<0.001) and 13±35% of its width (n.s.) were covered. Root coverage seems to be rather defect-type sensitive with best results obtained at canines with relatively shallow recessions. Mucosal thickness was considerably increased after surgery with a gradual decrease during the following 9 months. Thus, thickness of the marginal tissue rose from 0.82±0.27 mm to 1.49±0.54 mm 3 months after placement of the membrane (p<0.001). After 12 months, a mean thickness of 1.03±0.40 mm was observed (p<0.001). Even more pronounced alterations were noted for the alveolar lining mucosa with a threefold increase of thickness 3 months after surgery and a gradual decrease to about 1 mm after 12 months. Conclusions: The present results point to the considerable space making capacity of the bioresorbable membrane which probably allows for the ingrowth of a granulation tissue derived from the underlying structures. The gradual decline in mucosal thickness between months 6 and 9 after surgery may be paralleled by the maturation of the granulation tissue while complete resorption of the membrane had been accomplished. [source] IDENTIFICATION OF SALT FEATURES IN SEISMIC DATAJOURNAL OF PETROLEUM GEOLOGY, Issue 4 2008M. K. Jenyon Deciding on the viability of a salt deposit as a possible site for storage-cavern solution mining requires detailed geological studies of the salt and of its confining formations. Borehole data alone can seldom deliver the information required for such a study. It can impart great detail of the subsurface but only at the actual borehole location in an area. The most practical approach to developing 3D information is to carry out a seismic survey tied in to one or more boreholes which have been logged geophysically Ideally, a high-resolution seismic survey is needed to study relatively shallow zones of the subsurface and resolve the top and base of fairly thin beds. However in some cases it is possible to use "reach-me-down" seismic data acquired previously during hydrocarbon exploration. Although these data were not designed to meet the requirements of salt deposit studies, they may still be adequate for the purpose. Their use will lead to quicker and lower-cost results than the commissioning of a full field seismic survey with concomitant processing, although in both cases a seismic interpretation would be required. [source] Applications of model ,-hairpin peptidesJOURNAL OF PHARMACEUTICAL SCIENCES, Issue 12 2004Carol E. Stotz Abstract In recent years, ,-hairpin peptides have been studied in great detail. Much of the focus has been on the thermodynamic stability of ,-hairpin structure. Structural measurements have been conducted with nuclear magnetic resonance, with additional information obtained from circular dichroism, Fourier transform infrared, and molecular dynamic simulation studies. Point mutations, both in the ,-strands and in the turn region, have systematically explored the role of turn sequence, side-chain,side-chain interactions, intramolecular hydrogen bonding, and ,-strand length on ,-hairpin peptide conformational stability. In addition to studying the elements of structural stability independently, the cooperative nature of the individual components to combine to form the overall structure has also been investigated. Because the ,-hairpin peptides often spontaneously form their conformation, they have begun to serve as models for studying peptide binding and therapeutic agents. © 2004 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 93:2881,2894, 2004 [source] Constraining the age of Lateglacial and early Holocene pollen zones and tephra horizons in southern Sweden with Bayesian probability methods,JOURNAL OF QUATERNARY SCIENCE, Issue 4 2006B. Wohlfarth Abstract The sediment sequence from Hässeldala port in southeastern Sweden provides a unique Lateglacial/early Holocene record that contains five different tephra layers. Three of these have been geochemically identified as the Borrobol Tephra, the Hässeldalen Tephra and the 10-ka Askja Tephra. Twenty-eight high-resolution 14C measurements have been obtained and three different age models based on Bayesian statistics are employed to provide age estimates for the five different tephra layers. The chrono- and pollen stratigraphic framework supports the stratigraphic position of the Borrobol Tephra as found in Sweden at the very end of the Older Dryas pollen zone and provides the first age estimates for the Askja and Hässeldalen tephras. Our results, however, highlight the limitations that arise in attempting to establish a robust, chronologically independent lacustrine sequence that can be correlated in great detail to ice core or marine records. Radiocarbon samples are prone to error and sedimentation rates in lake basins may vary considerably due to a number of factors. Any type of valid and ,realistic' age model, therefore, has to take these limitations into account and needs to include this information in its prior assumptions. As a result, the age ranges for the specific horizons at Hässeldala port are large and calendar year estimates differ according to the assumptions of the age-model. Not only do these results provide a cautionary note for over-dependence on one age-model for the derivation of age estimates for specific horizons, but they also demonstrate that precise correlations to other palaeoarchives to detect leads or lags is problematic. Given the uncertainties associated with establishing age,depth models for sedimentary sequences spanning the Lateglacial period, however, this exercise employing Bayesian probability methods represents the best possible approach and provides the most statistically significant age estimates for the pollen zone boundaries and tephra horizons. Copyright © 2006 John Wiley & Sons, Ltd. [source] Assessment of the role of heparan sulfate in high molecular weight kininogen binding to human umbilical vein endothelial cellsJOURNAL OF THROMBOSIS AND HAEMOSTASIS, Issue 11 2003L.P. Fernando Summary., The assembly and activation of the kinin forming system components on human umbilical vein endothelial cells (HUVEC) have been studied in great detail. Proteins such as gC1qR, cytokeratin-1 and u-PAR have been identified to be responsible for Zn2+ -dependent binding of high molecular weight kininogen (HK) to HUVEC. Heparan sulfate has also been shown to have a major role in Zn2+ -dependent binding of HK to the endothelial cell line, Ea.hy 926. In this study, we have analyzed the possible contribution of heparan sulfate to high molecular weight kininogen binding to HUVEC using multiple approaches. The presence of heparan sulfate on HUVEC was analyzed by staining with an antibody specific for heparan sulfate. Incubation of the cells with bacterial heparinases removed the heparan sulfate from the cell surface to the level seen with a control antibody, however, the Zn2+ -dependent binding of HK was not affected. Further, blocking of heparan sulfate with a specific antibody to heparan sulfate even after digestion with heparinases did not reduce HK binding whereas antibodies to the proteins gC1qR and cytokeratin-1 consistently reduced the binding of HK to the endothelial cells. The binding intensities of FITC-labeled HK were similar in heparinase-treated and -untreated HUVEC. The rate of kallikrein formation by the assembly of factor XII, HK and PK were similar in both heparinase-treated and non-treated HUVEC. All of these data indicate that heparan sulfate does not contribute significantly to HK binding to HUVEC. [source] Thermovoltaic properties of hornet silkMICROSCOPY RESEARCH AND TECHNIQUE, Issue 11 2006S. Volynchik Abstract In silk from the larval silk caps of the Oriental hornet Vespa orientalis (Hymenoptera, Vespinae), temperature-dependent changes in the electric voltage have been recorded, with rise in the voltage occurring mainly upon rise in the temperature between 10,36°C. The peak voltage was measured between 32,38°C and attained 240,360 mV, but with further increase in temperature, the voltage decreased, dropping to 0 mV at about 45,50°C. Upon second measurement (of same silk specimen), the voltage peak usually occurred later (by 8,9°C) and at higher temperature than in the first measurement. Continuous measurements during warming up to 30°C followed by cooling down to 15°C yielded an hysteresis between the warming "line" and the cooling "line", the former often straight and the latter usually curved. Maintaining the silk specimen at a fixed temperature for a prolonged period (hours) initially causes the voltage to rise, then remain steady, and finally drop. Boiling the silk caps in tap water for 7,10 min exerts some changes in the silk properties, mainly a decrease in voltage level. The general behavior of the silk suggests that it is a polymer endowed with the qualities of an organic semiconductor. The various properties of the larval silk are discussed in great detail. Microsc. Res. Tech., 2006. © 2006 Wiley-Liss, Inc. [source] From fundamental studies of sporulation to applied spore researchMOLECULAR MICROBIOLOGY, Issue 2 2005Imrich Barák Summary Sporulation in the Gram-positive bacterium, Bacillus subtilis, has been used as an excellent model system to study cell differentiation for almost half a century. This research has given us a detailed picture of the genetic, physiological and biochemical mechanisms that allow bacteria to survive harsh environmental conditions by forming highly robust spores. Although many basic aspects of this process are now understood in great detail, including the crystal and NMR structures of some of the key proteins and their complexes, bacterial sporulation still continues to be a highly attractive model for studying various cell processes at a molecular level. There are several reasons for such scientific interest. First, some of the complex steps in sporulation are not fully understood and/or are only described by ,controversial' models. Second, intensive research on unicellular development of a single microorganism, B. subtilis, left us largely unaware of the multitude of diverse sporulation mechanisms in many other Gram-positive endospore and exospore formers. This diversity would likely be increased if we were to include sporulation processes in the Gram-negative spore formers. Spore formers have great potential in applied research. They have been used for many years as biodosimeters and as natural insecticides, exploited in the industrial production of enzymes, antibiotics, used as probiotics and, more, exploited as possible vectors for drug delivery, vaccine antigens and other immunomodulating molecules. This report describes these and other aspects of current fundamental and applied spore research that were presented at European Spores Conference held in Smolenice Castle, Slovakia, June 2004. [source] Social aspect of sustainable packagingPACKAGING TECHNOLOGY AND SCIENCE, Issue 6 2010Norbisimi Nordin Abstract Sustainability is one of the ,buzz' words that is highly discussed in the area of packaging nowadays. For many product manufacturing business, incorporation of sustainability principles into their business practice can only be visualized by others in the end product through packaging. Besides the criteria, underlying concepts and principles, most discussions towards achieving goals for sustainable packaging are focused on details of models and practices adopted by the industry, and the effectiveness and practicality of these practices in balancing the economic profits and environmental benefits. While the economic and environmental bases of packaging sustainability have been examined and discussed in great detail, the same is not true of social consideration. Although the success of sustainable packaging development actually relies on both technological development and social considerations, many of the social aspects of sustainable packaging are often overlooked. Although many companies have been putting the efforts and initiatives to elevate sustainability from an abstract goal into an immediate priority, relatively little is known about the consumers' insights of packaging sustainability. Recognizing the consumers as the final arbiter of the success of sustainable packaging, this paper will explore consumers' perceptions on the sustainable packaging concept, their perceptions of the impact to the environment and discuss factors that drive consumers' preferences and purchase decision. Discussion and information gathered in this paper is aimed to stimulate understanding on the importance of the social dimension of packaging sustainability and its role in supporting the efforts to improve sustainability practice. Copyright © 2010 John Wiley & Sons, Ltd. [source] Relationship between psychiatric symptoms and regional cerebral blood flow in patients with mild Alzheimer's diseasePSYCHOGERIATRICS, Issue 3 2008Keisuke NAKAJIMA Abstract Background:, Behavioral and psychological symptoms of dementia (BPSD) are frequently observed in patients with dementia and often cause serious problems. However, the cause of BPSD has not yet been elucidated. Moreover, the precise evaluation of BPSD in mild dementia has not been studied in any great detail. In the present study, we investigated the relationship between psychiatric symptoms and regional cerebral blood flow (rCBF) in patients with mild Alzheimer's disease (AD). Methods:, The present study included 47 patients (20 men and 27 women) who were diagnosed with mild AD. Mean patient age was 72.8 ± 8.2 years. Single photon emission computed tomography (SPECT) with 99mTc-ethyl cysteinate dimer (99mTc-ECD) was performed in all patients. The SPECT data were analyzed using a three-dimensional stereotactic region of interest template, which evaluated CBF in 24 segments. Psychiatric symptoms were evaluated in patients using the Brief Psychiatric Rating Scale. Each psychiatric symptom was designated as ,symptom present' in cases in which the BPRS item score was more than 3. We compared 10 segments of rCBF in symptom-present patients with those in symptom-absent patients. Results:, Motor retardation was the most common psychiatric symptom (36.2%), followed by depression (19.1%), anxiety (17.0%), emotional withdrawal (17.0%), and somatic concern (14.9%). Alzheimer's disease patients with motor retardation exhibited a tendency towards lower rCBF in seven segments (left callosomarginal, bilateral parietal, bilateral angular, and bilateral temporal). However, no specific tendency was observed in depression, anxiety, and somatic concern. Conclusions:, In the present study, we observed a tendency for decreased brain perfusion in patients with motor retardation. Further studies are necessary to confirm that this trend contributes to the appearance of psychiatric symptoms in patients with mild AD. [source] Temple, Economy, and Religion in First Millennium BabyloniaRELIGION COMPASS (ELECTRONIC), Issue 6 2008Michael Kozuh The study of economy and religion in Babylonia during the first millennium bc is primarily that of two well-documented temples, the Eanna temple of the city of Uruk and the Ebabbar of Sippar. The administrative archives of those temples , consisting of tens of thousands of cuneiform texts , allow us to understand parts of the temple economy in great detail, while at the same time this abundance of material frustrates traditional approaches to Babylonian religion. This essay aims in general to emphasize that Babylonian temples were large-scale, multifaceted religious institutions. Capitalizing on recent advancements in our technical understanding of the temple economy, it integrates these advancements into issues of broader religious, historical, intellectual, and economic significance. In particular, it stresses three points: first, the temples' amalgamated ruling structure fostered institutional permanence and should therefore be understood as a challenge to the ,temple-as-household' metaphor; second, large-scale centralization of wealth in the temples was necessary for advancements in Babylonian learned culture (especially in astronomy and mathematics); and, finally, the centralization of manpower in the temples gave them particular advantages in the politics of the first millennium bc. In the end, I argue that all of these are in fact manifestations of Babylonian religion in themselves. [source] Practitioner Review: The Role of Direct Observation in the Assessment of Young ChildrenTHE JOURNAL OF CHILD PSYCHOLOGY AND PSYCHIATRY AND ALLIED DISCIPLINES, Issue 7 2001A. D. Pellegrini In this review I examine the role of play and assessment in the lives of young children. These two seemingly opposing constructs are first defined. Next, I address a particularly important form of assessment, "high stakes" assessment, and argue that if it must be used, we should use a variety of assessment methods. One such method that I discuss in great detail is the use of direct observations of children's play. Examples of reliable and valid inferences about children's social cognitive functioning made with this family of methods are provided. Two specific observational instruments (one for observing play in the classroom and one for observing play in the playground) are presented. Recommendations for their use by practitioners are made. [source] General Comment No. 17 on "Authors' Rights"THE JOURNAL OF WORLD INTELLECTUAL PROPERTY, Issue 1 2007Hans Morten Haugen General Comment No. 17 on authors' rights is a comprehensive assessment of the normative content of article 15, paragraph 1(c) of the International Covenant on Economic, Social and Cultural Rights (the Covenant). Also, the obligations and violations are spelled out in great detail. It is found that the General Comment makes a clear distinction in principle between standard intellectual property rights and the protection given in accordance with article 15, paragraph 1(c). At the same time, the General Comment does not outline any specific tools for determining when an intellectual effort would result in human rights protection and when it would fall outside of the scope of this protection. Two clarifications have resulted in a positive reception of the General Comment among those who expressed criticism during the drafting. First, General Comment No. 17 acknowledges the need for human rights protection for local and indigenous communities. Second, General Comment No. 17 emphasizes the balance between the private interests of the authors and the other human rights recognized in the Covenant. [source] Study of the Kinetics and Morphology of Gas Hydrate FormationCHEMICAL ENGINEERING & TECHNOLOGY (CET), Issue 8 2006Abstract The kinetics and morphology of ethane hydrate formation were studied in a batch type reactor at a temperature of ca. 270,280,K, over a pressure range of 8.83,16.67,bar. The results of the experiments revealed that the formation kinetics were dependant on pressure, temperature, degree of supercooling, and stirring rate. Regardless of the saturation state, the primary nucleation always took place in the bulk of the water and the phase transition was always initiated at the surface of the vortex (gas-water interface). The rate of hydrate formation was observed to increase with an increase in pressure. The effect of stirring rate on nucleation and growth was emphasized in great detail. The experiments were performed at various stirring rates of 110,190,rpm. Higher rates of formation of gas hydrate were recorded at faster stirring rates. The appearance of nuclei and their subsequent growth at the interface, for different stirring rates, was explained by the proposed conceptual model of mass transfer resistances. The patterns of gas consumption rates, with changing rpm, have been visualized as due to a critical level of gas molecules in the immediate vicinity of the growing hydrate particle. Nucleation and decomposition gave a cyclic hysteresis-like phenomena. It was also observed that a change in pressure had a much greater effect on the rate of decomposition than it did on the formation rate. Morphological studies revealed that the ethane hydrate resembles thread or is cotton-like in appearance. The rate of gas consumption during nucleation, with different rpm and pressures, and the percentage decomposition at different pressures, were explained precisely for ethane hydrate. [source] Entropy production in chiral symmetry breaking transitions,CHIRALITY, Issue 3-4 2008Dilip Kondepudi Abstract It is now well known that nonequilibrium chemical systems may reach conditions that spontaneously generate chiral asymmetry. One can find a host of model reactions that exhibit such behavior in the literature. Among these, models based on one originally devised by Frank have been studied extensively. Though the kinetic aspects of such model reactions have been discussed in great detail, the behavior of entropy in such systems is rarely discussed. In this article, the rate of entropy production per unit volume, ,, in a modified Frank model is discussed. It is shown that the slope of , changes at the point at which the asymmetric states appear, behavior similar to that observed in second-order phase transitions. Chirality, 2008. © 2007 Wiley-Liss, Inc. [source] | |||||||||||||||||||||||||