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Selected AbstractsTo Commit or Not to Commit: Modeling Agent Conversations for ActionCOMPUTATIONAL INTELLIGENCE, Issue 2 2002Roberto A. Flores Conversations are sequences of messages exchanged among interacting agents. For conversations to be meaningful, agents ought to follow commonly known specifications limiting the types of messages that can be exchanged at any point in the conversation. These specifications are usually implemented using conversation policies (which are rules of inference) or conversation protocols (which are predefined conversation templates). In this article we present a semantic model for specifying conversations using conversation policies. This model is based on the principles that the negotiation and uptake of shared social commitments entail the adoption of obligations to action, which indicate the actions that agents have agreed to perform. In the same way, obligations are retracted based on the negotiation to discharge their corresponding shared social commitments. Based on these principles, conversations are specified as interaction specifications that model the ideal sequencing of agent participations negotiating the execution of actions in a joint activity. These specifications not only specify the adoption and discharge of shared commitments and obligations during an activity, but also indicate the commitments and obligations that are required (as preconditions) or that outlive a joint activity (as postconditions). We model the Contract Net Protocol as an example of the specification of conversations in a joint activity. [source] Manganese cell labeling of murine hepatocytes using manganese(III)-transferrin,CONTRAST MEDIA & MOLECULAR IMAGING, Issue 3 2008Christopher H. Sotak Abstract Manganese(III)-transferrin [Mn(III),Tf] was investigated as a way to accomplish manganese-labeling of murine hepatocytes for MRI contrast. It is postulated that Mn(III),Tf can exploit the same transferrin-receptor-dependent and -independent metabolic pathways used by hepatocytes to transport the iron analog Fe(III),Tf. More specifically, it was investigated whether manganese delivered by transferrin could give MRI contrast in hepatocytes. Comparison of the T1 and T2 relaxation times of Mn(III),Tf and Fe(III),Tf over the same concentration range showed that the r1 relaxivities of the two metalloproteins are the same in vitro, with little contribution from paramagnetic enhancement. The degree of manganese cell labeling following incubation for 2,7,h in 31.5,µm Mn(III),Tf was comparable to that of hepatocytes incubated in 500,µm Mn2+ for 1,h. The intrinsic manganese tissue relaxivity between Mn(III),Tf-labeled and Mn2+ -labeled cells was found to be the same, consistent with Mn(III) being released from transferrin and reduced to Mn2+. For both treatment regimens, manganese uptake by hepatocytes appeared to saturate in the first 1,2,h of the incubation period and may explain why the efficiency of hepatocyte cell labeling by the two methods appeared to be comparable in spite of the ,16-fold difference in effective manganese concentration. Hepatocytes continuously released manganese, as detected by MRI, and this was the same for both Mn2+ - and Mn(III),Tf-labeled cells. Manganese release may be the result of normal hepatocyte function, much in the same way that hepatocytes excrete manganese into the bile in vivo. This approach exploits a biological process,namely receptor binding, endocytosis and endosomal acidification,to initiate the release of an MRI contrast agent, potentially conferring more specificity to the labeling process. The ubiquitous expression of transferrin receptors by eukaryotic cells should make Mn(III),Tf particularly useful for manganese labeling of a wide variety of cells both in culture and in vivo. Published in 2008 by John Wiley & Sons, Ltd. [source] Early handling reduces vulnerability of rats to activity-based anorexiaDEVELOPMENTAL PSYCHOBIOLOGY, Issue 7 2006O. Carrera Abstract Resistance to restricted feeding with and without wheel access was tested in rats handled (H) for 20 days since birth. Weight loss produced by 1.5-hr restricted food access was less in H than in non-handled (NH) males when tested aged 41 days. At this age combining food restriction with access to a running wheel (a procedure commonly known as activity-based anorexia, ABA) produced very rapid weight loss and no effect of handling was detected. When 75-day females were tested in the same way, under the ABA procedure H rats took longer than NH controls to reach the removal criterion. Simply restricting food access in these females produced variable weight loss, without detection of any handling effect. No differences in food intake or running were detected between H and NH rats in either males or females. In conclusion, handling seems to have a direct effect on rats' later response to either food deprivation alone or to an ABA procedure. © 2006 Wiley Periodicals, Inc. Dev Psychobiol 48: 520,527, 2006. [source] Emotion, Perception and PerspectiveDIALECTICA, Issue 1 2006Julien A. Deonna The content of an emotion, unlike the content of a perception, is directly dependent on the motivational set of the subject experiencing the emotion. Given the instability of this motivational set, it might be thought that there is no sense in which emotions can be said to pick up information about the environment in the same way that perception does. Whereas it is admitted that perception tracks for us what is the case in the environment, no such tracking relation, it is argued, holds between one's emotions and what they are about. It is to this worry , that the construal of the emotions as perceptions inevitably raises , that this paper tries to respond. In this paper, I suggest that when it is realized that one dimension of perception itself is directly dependent on the perceiver's perspective on her environment, then emotion, which is also essentially perspectival in this sense, bears the comparison with perception very well. After having clarified the nature and the role that perspective plays in perception, I argue that, in the case of emotions, the same perspectival role can be played by agents' long-standing evaluative tendencies and character traits. The resulting conception of emotion as perception is then tested against possible objections. [source] TERRORISM AND THE RETURNS TO OILECONOMICS & POLITICS, Issue 3 2009BROCK BLOMBERG The effect of terrorism on global oil prices has been largely explained through demand-side effects. We estimate an empirical model to re-examine the effect of terrorism on the price of global oil stocks across oil market regimes that reflect different supply constraints. We believe that terrorism will have larger impacts when global capacity is tight (i.e. when global demand is close to global supply). This means that any shock to capacity (say by conflict) should have the largest impact on profits before the first OPEC shock in the early 1970s. Since then, conflict shocks would not allow firms to exploit production in the same way, thus reducing the available profits that could be garnered by such production manipulation. If capacity constraints are binding when a conflict occurs, then we predict that a positive stock price reaction can be expected for oil firms from such a shock. We exploit a new panel dataset to investigate the relationship between oil profitability and conflict, using conflict data from the top 20 oil producing and exporting countries in the world. We show that in the later part of our sample, 1974,2005, as cartel behavior of OPEC member countries has diminished and as conflict has become more regular and thus the information surrounding it noisier, oil stock prices do not increase in response to conflict. However, in earlier capacity constrained eras, we find that oil stocks can in fact increase in response to conflict. In some cases, the impact of conflict may cause the return of oil stocks to increase by as much as 10 percentage points. [source] Working Electrodes from Amalgam Paste for Electrochemical MeasurementsELECTROANALYSIS, Issue 4 2008Bogdan Yosypchuk Abstract Paste electrode with paste amalgam as an active electrode material is described here for the first time. Designed electrode from silver paste amalgam (AgA-PE) is solely metallic and does not contain any organic binder. Mechanical surface regeneration of AgA-PE is performed in the same way as for classical carbon paste electrodes and reproducibility of such regeneration is about 10%. Electrochemical surface regeneration appeared very efficient for most measurements. In dependence on paste metal content, the electrode surface can be liquid (resembling a film) or rather solid. The hydrogen overvoltage on AgA-PE is high, and the electrode allows measurements at highly negative potentials. AgA-PE is well suited for study of reduction or oxidation processes without an accumulation step. Anodic stripping voltammetry of some metals tested on the electrode is influenced by formation of intermetallic compounds. The measurement based on cathodic stripping voltammetry (adenine, cysteine) and on catalytic processes from adsorbed state (complex of osmium tetroxide with 2,2,-bipyridine) can be performed on AgA-PE practically under the same conditions as found earlier for HMDE and for silver solid amalgam electrode. The working electrode from paste amalgam combines the advantages of paste and metal electrodes. [source] Using Film Text to Support Reluctant WritersENGLISH IN EDUCATION, Issue 1 2002Collette Higgins Abstract This article is the result of working with several schools concerned with improving achievement in boys' writing. It begins by describing a range of effective teaching and learning strategies, observed in my role as a Literacy Consultant, which had a positive influence on writers especially boys. The article goes on to explore how a small group of boys, described by their teacher as ,reluctant writers', were encouraged by the use of film text to make the most of their preferences for action-driven narratives to improve story writing. It suggests that ,slowing down' this action in the author's eye gives pupils, and boys in particular, an opportunity to consider detail to enhance composition in the same way that a film director uses camera angles to capture the viewer's attention. [source] The exponentiated Gumbel distribution with climate applicationENVIRONMETRICS, Issue 1 2006Saralees Nadarajah Abstract The Gumbel distribution is perhaps the most widely applied statistical distribution for climate modeling. In this article we introduce a distribution that generalizes the standard Gumbel distribution in the same way the exponentiated exponential distribution generalizes the standard exponential distribution. We refer to this new distribution as the exponentiated Gumbel distribution. We provide a comprehensive treatment of the mathematical properties of this new distribution and illustrate its use for modeling rainfall data from Orlando, Florida. Among the mathematical properties, we derive the analytical shapes of the corresponding probability density function and the hazard rate function, calculate expressions for the nth moment and the asymptotic distribution of the extreme order statistics, and investigate the variation of the skewness and kurtosis measures. We also discuss estimation by the method of maximum likelihood. Copyright © 2005 John Wiley & Sons, Ltd. [source] Embryonic Arrhythmia by Inhibition of HERG Channels: A Common Hypoxia-related Teratogenic Mechanism for Antiepileptic Drugs?EPILEPSIA, Issue 5 2002Faranak Azarbayjani Summary: ,Purpose: There is evidence that drug-induced embryonic arrhythmia initiates phenytoin (PHT) teratogenicity. The arrhythmia, which links to the potential of PHT to inhibit a specific potassium channel (Ikr), may result in episodes of embryonic ischemia and generation of reactive oxygen species (ROS) at reperfusion. This study sought to determine whether the proposed mechanism might be relevant for the teratogenic antiepileptic drug trimethadione (TMO). Methods: Effects on embryonic heart rhythm during various stages of organogenesis were examined in CD-1 mice after maternal administration (125,1,000 mg/kg) of dimethadione (DMO), the pharmacologically active metabolite of TMO. Palatal development was examined after administration of a teratogenic dose of DMO and after simultaneous treatment with DMO and a ROS-capturing agent (,-phenyl- N -tert-butyl-nitrone; PBN). The Ikr blocking potentials of TMO and DMO were investigated in HERG-transfected cells by using voltage patch-clamping tests. Results: DMO caused stage-specific (gestation days 9,13 only) and dose-dependent embryonic bradycardia and arrhythmia at clinically relevant maternal plasma concentrations (3,11 mM). Hemorrhage in the nasopharyngeal part of the embryonic palate (within 24 h) preceded cleft palate in fetuses at term. Simultaneous treatment with PBN significantly reduced the incidence of DMO-induced cleft palate, from 40 to 13%. Voltage patch-clamping studies showed that particularly DMO (70% inhibition), but also TMO, had Ikr blocking potential at clinically relevant concentrations. Conclusions: TMO teratogenicity, in the same way as previously shown for PHT, was associated with Ikr -mediated episodes of embryonic cardiac arrhythmia and hypoxia/reoxygenation damage. [source] A Behavioral Syndrome in the Adzuki Bean Beetle: Genetic Correlation Among Death Feigning, Activity, and Mating BehaviorETHOLOGY, Issue 2 2010Satoshi Nakayama When studying animal behavior, it is often necessary to examine traits as a package, rather than as isolated units. Evidence suggests that individuals behave in a consistent manner across different contexts or over time; that is, behavioral syndromes. We compared locomotor activity levels and mating success between beetles derived from two regimes artificially selected for the duration of death-feigning behavior in the adzuki bean beetle, Callosobruchus chinensis. The two selection regimes comprised strains with higher (L) and lower (S) intensity (frequency and duration) of death-feigning behavior, respectively. We found that S strains had higher activity levels than L strains for both sexes, i.e., there is a negative genetic correlation between death feigning and activity. In addition, we found that S strains had higher mating success than L strains, presumably due to higher activity, in males but not in females. We thus demonstrate that death feigning is genetically correlated to mating behavior in males but not females in this species, suggesting that behavioral correlations may not always reflect in the same way in both sexes. [source] Shaman/Scientist: Jungian Insights for the Anthropological Study of ReligionETHOS, Issue 4 2001Associate Professor Karen A. Smyers Anthropology still regards the experience of religion the same way it did when its interpretive paradigm was based on "scientific objectivity." To understand this situation, the work of C. G. Jung is helpful in two ways. First, by exploring how anthropology has dismissed Jung as a cultural universalist and/or mystic, often without an actual consideration of his writings, we see how he signifies what the field defines itself against. Second, Jung's empirical forays into the religious worldview provide us with both methodological and descriptive insights about that realm in which many of our informants (and even some anthropologists) live. [source] Retinol binding protein isolated from acute renal failure patients inhibits polymorphonuclear leucocyte functionsEUROPEAN JOURNAL OF CLINICAL INVESTIGATION, Issue 11 2004G. Cohen Abstract Background, Protein factors accumulating in sera of patients with end-stage renal disease (ESRD) that interfere with the nonspecific immune response by inhibiting essential functions of polymorphonuclear leucocytes (PMNLs) have previously been described. No such factor has been isolated from acute renal failure (ARF) patients to date. Materials and methods, Using a three-step chromatographic procedure involving ion exchange, size exclusion and hydrophobic interaction chromatography we purified the apo- and holo-form of retinol binding protein (RBP) from high-flux dialyser (polyacrylonitrile; AN69) ultrafiltrates of patients with ARF. Their effect on the chemotaxis of PMNLs isolated from healthy donors was determined by the under-agarose method. Whole-blood assays applying flow cytometry were used to assess phagocytosis and the oxidative metabolism of PMNLs. Apoptosis was assessed by determining the DNA content using propidium iodide. Results, Isolated apo- and holo-forms of RBP were truncated on their C-terminus as determined by mass spectrometry. All isolates significantly inhibited the chemotactic movement of PMNLs obtained from healthy donors and the PMNL oxidative metabolism stimulated by E. coli. These effects were concentration dependent. Retinol binding protein had no influence on the PMNL oxidative metabolism stimulated by PMA and on PMNL phagocytosis. Commercially available RBP isolated from urine influenced PMNL functions in the same way. Inhibition of p38 mitogen-activated protein kinase (MAPK) by SB203580 significantly attenuated the phagocytosis-induced respiratory burst and RBP did not lead to a further decrease. Polymorphonuclear leucocyte apoptosis was significantly inhibited by RBP. Conclusions, The apo- and holo-forms of RBP isolated from the ultrafiltrate of ARF patients inhibit PMNL chemotaxis, oxidative metabolism and apoptosis. Therefore, RBP may be considered a uraemic toxin contributing to a disturbed immune defence. [source] Improving clinical assessment: evaluating students' ability to identify and apply clinical criteriaEUROPEAN JOURNAL OF DENTAL EDUCATION, Issue 3 2010C. Redwood Abstract Aim:, There is ongoing concern by health educators over the inability of professionals to accurately self-assess their clinical behaviour and standards, resulting in doubts over a key expectation of effective self-regulation in the health professions. Participation by students in the assessment process has been shown to increase the understanding of assessment criteria in written assessment tasks. How this might transfer to the clinical setting is the focus of this study. This paper is part of an ongoing investigation of the impact on learning of a series of activities that provides students with opportunities to discuss and apply criteria and standards associated with self-assessment in clinical dentistry. Our aim was to evaluate whether participation in these assessment activities improved the ability of first-year dental students to recognise behaviours demonstrated by ,peers' in videos of clinical scenarios and to relate these to the assessment criteria. Materials and methods:, A series of three workshops in conjunction with weekly clinical assessment activities in Semesters 1 and 2 were use to support first-year students' learning of clinical assessment criteria. The design of the workshops was based on the principles of social constructivist theories of learning and the concept of tacit knowledge. Accordingly workshop activities were planned around videos that were specifically constructed to illustrate procedures and behaviours typical of those observed by staff and tutors in the first year of the dental course at The University of Adelaide, Australia. First-year students viewed the videos prior to and after the workshops and recorded observed behaviours that related to the assessment criteria that were used in their clinical practice course. Student learning outcomes were assessed 10,14 weeks after the initial workshop and again up to 42 weeks later. To check whether learning resulted from repeated viewing of the videos without formal discussion, a reference group of third-year students who did not attend the workshops also viewed the videos two times, separated by 12 weeks, and recorded observations in the same way. Results:, There was no consistent evidence that repeat viewing of the videos in isolation resulted in improved recognition of ,peer' behaviours by third-year dental students. Results for the first-year students indicated that the workshops and clinical assessment activities had a significantly positive effect on the ability of students to identify ,peer' behaviours related to the criteria used for clinical assessment. In particular, students' recognition in others of knowledge and professional behaviours improved significantly. This improvement was retained over the year and students were able to recognise these behaviours in other scenarios relevant to their year level. Conclusions:, This early exposure to the process of clinical assessment, coupled with ongoing self-assessment and tutor feedback throughout first year, improved the ability of first-year students to identify and apply some key assessment criteria to observed ,peer' behaviour, and this ability was retained over time. [source] Calorimetric study of milk fat/rapeseed oil blends and their interesterification productsEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 4 2009Mario Aguedo Abstract Milk fat (MF) and rapeseed oil (RO) blends were analyzed by differential scanning calorimetry (DSC). It was shown that peak and onset temperatures can be used to determine the percentage of each fat in the blend and that the relative enthalpy of one peak assigned to low-melting triacylglycerols (TAG) can also be used to determine the percentage of RO in the blend. A linear relation was also established between MF content of the blend and its dropping point (DP), indicating that DP can be linearly related with the above DSC data. A blend of MF/RO 70,:,30 (wt/wt) was then chosen as a model system for enzymatic interesterification (EIE). The applicability of DSC analyses to EIE products was checked and a correct correlation could be established between DSC values and the interesterification degree and DP. Among the data from the DSC profiles, the peak associated with low-melting TAG was the best indicator of the reaction course. In the same way, a high-melting MF stearin fraction was interesterified with RO. In that case, onset temperatures and peak "a" were better reaction indicators than for the interesterified MF/RO blend. We therefore suggest that values from DSC endotherms could be used to monitor EIE of fat blends. [source] The enigma of Lenin's (1870,1924) maladyEUROPEAN JOURNAL OF NEUROLOGY, Issue 6 2004V. Lerner The health of heads of states is not always handled in the same way as an incapacitating disability in ordinary professionals. Instead of suspension of responsibilities, the health status of political leaders is concealed, especially when the illness is perceived as stigmatizing, such as organic mental impairment or sexual disorder. The objective of the present paper is to analyse the malady of Lenin (1870,1924) in the light of relevant and new medical information. It is hoped that this will accentuate the need for transparency when the health of a statesman is concerned. [source] The Synthesis of the Dimethyl Ester of Quino[4,4a,5,6- efg]-Annulated 7-Demethyl-8-deethylmesoporphyrin and Three of Its Isomers with Unprecedented peri -Condensed Quinoline Porphyrin Structures.EUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 19 2004Molecules with Outstanding Properties as Sensitizers for Photodynamic Therapy in the Far-Red Region of the Visible Spectrum Abstract The mesoporphyrin dimethyl ester nickel complex has been formylated via the Vilsmeier method. The four possible mono meso-formyl derivatives were isolated and characterized. Wadsworth,Emmons coupling with the anion of (diethylphosphono)acetonitrile converted these aldehydes into the four novel meso acrylonitriles. Brief treatment of these acrylonitrile systems in hot trichloroacetic acid resulted in the formation of four achiral porphyrin derivatives with unprecedented nickel complexes of quino-fused porphyrins. Subsequent removal of the nickel gave four quino-porphyrin free bases: quino[4,4a,5,6- efg]-annulated 7-demethyl-8-deethylmesoporphyrin dimethyl ester 6a, 2,-(methoxycarbonyl)quino[4,4a,5,6- jkl]-annulated 12-demethyl-13-de[2,-(methoxycarbonyl)ethyl]mesoporphyrin dimethyl ester 6b, 2,-(methoxycarbonyl)quino[4,4a,5,6- qrs]-annulated 18-demethyl-17-de(2,-methoxycarbonylethyl)mesoporphyrin dimethyl ester 6c and quino[4,5,6,7- abt]-annulated 2-demethyl-3-deethylmesoporphyrin dimethyl ester 6d. The structures of these systems were unambiguously determined via mass spectroscopy and a plethora of NMR techniques. In the same way, etioporphyrin and octaethylporphyrin were converted into the corresponding peri -condensed quinoporphyrins as products, which shows that the formation of novel pericondensed quino-porphyrins is a general reaction in the porphyrin series and will have a wide scope in this field. Also, a plausible reaction mechanism for the formation of the quinoporphyrin systems was derived. As a first test for the use of these systems as sensitizers in far-red phototherapy, the quantum yield of singlet oxygen generation by 6a in toluene was studied. This quantum yield is 0.77, which is even higher than the singlet oxygen generation by sensitized meso-tetraphenylporphyrin. Secondly, when Chinese Hamster ovary (CHO) cells were incubated in medium which contained up to 15 ,g/ml of 6a, the survival rate of the cells in the dark is complete within experimental error, showing that under these conditions, 6a is not toxic to CHO cells. When CHO cells incubated in medium containing 6a in concentrations of 1 ,g/ml and higher were treated with white light of intensity 30 mW/cm2 for 15 minutes, complete cell death was observed. Based on these facts, we expect that all four achiral systems will show very promising properties to form the basis of a photodynamic therapy in far-red light. The fact that these systems are achiral is an additional bonus for medical applications. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2004) [source] The structure of perceived qualities of situationsEUROPEAN JOURNAL OF SOCIAL PSYCHOLOGY, Issue 6 2005John A. Edwards Situations can be seen as having attributes or qualities in much the same way as people have traits. The structure of people's perceptions of these situation qualities was explored. A comprehensive list of adjectives that might describe situations was generated, and people rated situations using samples of the words. Across several samples of words and participants and several analytic methods, four factors show up regularly (positivity, negativity, productivity, and ease of negotiation). In a second study, it was shown that these factors predict the way in which people freely sort situations. The conceptual nature of these factors and of situation qualities is discussed, with particular emphasis on how people's goals and perceived outcomes influence their perceptions of situations. Copyright © 2005 John Wiley & Sons, Ltd. [source] Resolving Deadlock: Why International Organisations Introduce Soft LawEUROPEAN LAW JOURNAL, Issue 2 2006Armin Schäfer Instead the EU relies on soft law that does not legally bind governments in the same way as the Community Method used to. The literature assumes that soft law is chosen to achieve common objectives given considerable diversity among the Member States. In contrast, this paper suggests that non-binding coordination is first and foremost a means to foster compromises in the absence of substantial agreements. Three case studies demonstrate that international organisations have repeatedly relied on soft law to overcome disagreements among their members. The IMF, the OECD, and the EU introduced soft coordination at times of institutional crisis to prevent a breakdown of negotiations. [source] Cranial neural crest cell migration in the Australian lungfish, Neoceratodus forsteriEVOLUTION AND DEVELOPMENT, Issue 4 2000Pierre Falck SUMMARY A crucial role for the cranial neural crest in head development has been established for both actinopterygian fishes and tetrapods. It has been claimed, however, that the neural crest is unimportant for head development in the Australian lungfish (Neoceratodus forsteri ,), a member of the group (Dipnoi) which is commonly considered to be the living sister group of the tetrapods. In the present study, we used scanning electron microscopy to study cranial neural crest development in the Australian lungfish. Our results, contrary to those of Kemp, show that cranial neural crest cells do emerge and migrate in the Australian lungfish in the same way as in other vertebrates, forming mandibular, hyoid, and branchial streams. The major difference is in the timing of the onset of cranial neural crest migration. It is delayed in the Australian lungfish in comparison with their living sister group the Lissamphibia. Furthermore, the delay in timing between the emergence of the hyoid and branchial crest streams is very long, indicating a steeper anterior-posterior gradient than in amphibians. We are now extending our work on lungfish head development to include experimental studies (ablation of selected streams of neural crest cells) and fate mapping (using fluoresent tracer dyes such as DiI) to document the normal fate as well as the role in head patterning of the cranial neural crest in the Australian lungfish. [source] Expression and regulation of alkaline phosphatases in human breast cancer MCF-7 cellsFEBS JOURNAL, Issue 5 2000Lai-Chen Tsai The effect of retinoic acid and dexamethasone on alkaline phosphatase (AP) expression was investigated in human breast cancer MCF-7 cells. Cellular AP activity was induced significantly by retinoic acid or dexamethasone in a time-dependent and dose-dependent fashion. A marked synergistic induction of AP activity was observed when the cells were incubated with both agents simultaneously. Two AP isozymes, tissue-nonspecific (TNAP) and intestinal (IAP), were shown to be expressed in MCF-7 cells as confirmed by the differential rate of thermal inactivation of these isozymes and RT-PCR. Based on the two-isozyme thermal-inactivation model, the specific activities for TNAP and IAP in each sample were analyzed. TNAP activity was induced only by retinoic acid and IAP activity was induced only by dexamethasone. Whereas dexamethasone conferred no significant effect on TNAP activity, retinoic acid was shown to inhibit IAP activity by , 50%. Interestingly, TNAP was found to be the only isozyme activity superinduced when the cells were costimulated with retinoic acid and dexamethasone. Northern blot and RT-PCR analysis were then used to demonstrate that the steady-state TNAP mRNA level was also superinduced, which indicates that the superinduction is regulated at the transcriptional or post-transcriptional levels. In the presence of the glucocorticoid receptor antagonist RU486, the dexamethasone-mediated induction of IAP activity was blocked completely as expected. However, the ability of RU486 to antagonize the action of glucocorticoid was greatly compromised in dexamethasone-mediated superinduction of TNAP activity. Furthermore, in the presence of retinoic acid, RU486 behaved as an agonist, and conferred superinduction of TNAP gene expression in the same way as dexamethasone. Taken together, these observations suggest that the induction of IAP activity by dexamethasone and the superinduction of TNAP by dexamethasone were mediated through distinct regulatory pathways. In addition, retinoic acid plays an essential role in the superinduction of TNAP gene expression by enabling dexamethasone to exert its agonist activity, which otherwise has no effect. [source] Regulation of anaerobic arginine catabolism in Bacillus licheniformis by a protein of the Crp/Fnr familyFEMS MICROBIOLOGY LETTERS, Issue 2 2000Abdelouahid Maghnouj Abstract Arginine anaerobic catabolism occurs in Bacillus licheniformis through the arginine deiminase pathway, encoded by the gene cluster arcABDC. We report here the involvement of a new protein, ArcR, in the regulation of the pathway. ArcR is a protein of the Crp/Fnr family encoded by a gene located 109 bp downstream from arcC. It binds to a palindromic sequence, very similar to an Escherichia coli Crp binding site, located upstream from arcA. Residues in the C-terminal domain of Crp that form the DNA binding motif, in particular residues Arg-180 and Glu-181 that make specific bonds with DNA, are conserved in ArcR, suggesting that the complexes formed with DNA by Crp and ArcR are similar. Moreover, the pattern of DNase I hypersensitivity sites induced by the binding of ArcR suggests that ArcR bends the DNA in the same way as Crp. From the absence of anaerobic induction following inactivation of arcR and from the existence of a binding site upstream of the arcA transcription start point, it can be inferred that ArcR is an activator of the arginine deiminase pathway. [source] Population genetic structure reveals terrestrial affinities for a headwater stream insectFRESHWATER BIOLOGY, Issue 10 2007DEBRA S. FINN Summary 1. The spatial distribution of stream-dwelling organisms is often considered to be limited primarily according to the hierarchical structure of the hydrologic network, and previous conceptual models of population genetic structure have reflected this generality. Headwater specialists, however, are confined to short upstream sections of the network, and therefore are unlikely to respond in the same way as species with a broader range of habitat tolerance. 2. Here, we propose a model to describe spatial patterns of genetic diversity in headwater specialists with a limited ability for among-stream dispersal. The headwater model predicts a partitioning of genetic variance according to higher-elevation ,islands' of terrestrial habitat that provide required headwater stream conditions. The model therefore expects a geographic pattern of genetic variance similar to that expected for low-dispersal terrestrial species occupying the adjacent habitat. 3. Using a 1032-bp mitochondrial DNA fragment encompassing parts of the COI and COII genes, we demonstrate that Madrean Sky Islands populations of the giant water bug Abedus herberti conform to the proposed headwater model. Furthermore, they exhibit phylogeographic patterns broadly concordant with those shown for several terrestrial species in the region, including a major zone of discontinuity in the Chiricahua mountain range. 4. Overall, populations are highly isolated from one another, and a nested clade analysis suggested that A. herberti population structure, similarly to terrestrial Sky Islands species studied previously, has been influenced by Pleistocene climatic cycles causing expansion and contraction of temperate woodland habitat. 5. Because they have no ability to disperse among present-day mountaintop habitat islands, A. herberti and other headwater species with limited dispersal ability are vulnerable to the projected increasing rate of climatic warming in this region. [source] Safety pharmacology in the nonclinical assessment of new medicinal products: definition, place, interest and difficultiesFUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 2 2002Jean-Roger Claude Until the year 2000 there was no internationally-accepted definition for the terms used in nonclinical pharmacology (primary, secondary pharmacodynamics, discovery, safety pharmacology, etc). Now, after ICH5 (San Diego, November 2000), a harmonisation of the nomenclature is adopted: safety pharmacology is defined as the studies that investigate the potential undesirable pharmacodynamic effects of a medicinal product on physiological functions in relationship to exposure. Consequently, safety pharmacology studies are a part of the safety assessment for a new product, in the same way than toxicological studies, and a basic battery of tests (core battery) has to be conducted prior to the first administration to humans. Safety pharmacology studies are of peculiar interest: they show a good predictive potential for humans, they do not require a large number of laboratory animals, long-term studies, large amount of products and they are more dynamic and more flexible than toxicological studies. Nevertheless, many difficulties occur for the implementation in industry, related to practical and/or scientific problems: location of the studies, routine activity for the pharmacologists, sometimes difficulties in the relationship between toxicologists and pharmacologists, adaptation to the GLP requirements, elaboration of an early relevant scientific programme, necessity to go to contract-labs or to academic research for unusual or for up to date methods, etc. To conclude, a retrospective timetable of the regulatory evolution for the last 10 years will be provided, as an illustration of the worldwide progress in the concept of `harmonisation' for the assessment of new medicinal products. [source] ,SPRACHKULTUR' IN LAY AND ACADEMIC DISCOURSE IN MODERN GERMANY1GERMAN LIFE AND LETTERS, Issue 4 2008Winifred V. Davies ABSTRACT The term ,Sprachkultur' is common in German-language academic and lay discourse, but what exactly does it mean? Is it used in the same way by trained and lay linguists? This article defines the term and traces its history, before going on to compare and contrast its use by both groups. Data taken from lay-linguistic works are analysed and two recurring motifs (i. the link between morality and linguistic usage and ii. accuracy/clarity) are discussed to see what light they throw on conceptions of language and language use. The concluding section sums up the similarities and differences between lay and academic linguists. The latter tend to concentrate on ,Sprachgebrauchskultur' whereas the former are prepared to criticise the language system as well. The stress laid by lay linguists on accuracy and the link between morality and linguistic choices reflects a ,telementational' view of language which has major shortcomings, and appears to be rooted in a world-view that equates diversity with cultural and ideological fragmentation rather than seeing it as enriching. However, the study of pronouncements by trained linguists shows that their work, too, reflects ideological assumptions about the nature of standard and other varieties of German. [source] Adaptation of soil microbial communities to temperature: comparison of fungi and bacteria in a laboratory experimentGLOBAL CHANGE BIOLOGY, Issue 12 2009GEMA BÁRCENAS-MORENO Abstract Temperature not only has direct effects on microbial activity, but can also affect activity indirectly by changing the temperature dependency of the community. This would result in communities performing better over time in response to increased temperatures. We have for the first time studied the effect of soil temperature (5,50 °C) on the community adaptation of both bacterial (leucine incorporation) and fungal growth (acetate-in-ergosterol incorporation). Growth at different temperatures was estimated after about a month using a short-term assay to avoid confounding the effects of temperature on substrate availability. Before the experiment started, fungal and bacterial growth was optimal around 30 °C. Increasing soil temperature above this resulted in an increase in the optimum for bacterial growth, correlated to soil temperature, with parallel shifts in the total response curve. Below the optimum, soil temperature had only minor effects, although lower temperatures selected for communities growing better at the lowest temperature. Fungi were affected in the same way as bacteria, with large shifts in temperature tolerance at soil temperatures above that of optimum for growth. A simplified technique, only comparing growth at two contrasting temperatures, gave similar results as using a complete temperature curve, allowing for large scale measurements also in field situations with small differences in temperature. [source] Responses of plants in polar regions to UVB exposure: a meta-analysisGLOBAL CHANGE BIOLOGY, Issue 11 2009KEVIN K. NEWSHAM Abstract We report a meta-analysis of data from 34 field studies into the effects of ultraviolet B (UVB) radiation on Arctic and Antarctic bryophytes and angiosperms. The studies measured plant responses to decreases in UVB radiation under screens, natural fluctuations in UVB irradiance or increases in UVB radiation applied from fluorescent UV lamps. Exposure to UVB radiation was found to increase the concentrations of UVB absorbing compounds in leaves or thalli by 7% and 25% (expressed on a mass or area basis, respectively). UVB exposure also reduced aboveground biomass and plant height by 15% and 10%, respectively, and increased DNA damage by 90%. No effects of UVB exposure were found on carotenoid or chlorophyll concentrations, net photosynthesis, Fv/Fm or ,PSII, belowground or total biomass, leaf mass, leaf area or specific leaf area (SLA). The methodology adopted influenced the concentration of UVB absorbing compounds, with screens and natural fluctuations promoting significant changes in the concentrations of these pigments, but lamps failing to elicit a response. Greater reductions in leaf area and SLA, and greater increases in concentrations of carotenoids, were found in experiments based in Antarctica than in those in the Arctic. Bryophytes typically responded in the same way as angiosperms to UVB exposure. Regression analyses indicated that the percentage difference in UVB dose between treatment and control plots was positively associated with concentrations of UVB absorbing compounds and carotenoids, and negatively so with aboveground biomass and leaf area. We conclude that, despite being dominated by bryophytes, the vegetation of polar regions responds to UVB exposure in a similar way to higher plant-dominated vegetation at lower latitudes. In broad terms, the exposure of plants in these regions to UVB radiation elicits the synthesis of UVB absorbing compounds, reduces aboveground biomass and height, and increases DNA damage. [source] Are local weather, NDVI and NAO consistent determinants of red deer weight across three contrasting European countries?GLOBAL CHANGE BIOLOGY, Issue 7 2009MARÍA MARTÍNEZ-JAUREGUI Abstract There are multiple paths via which environmental variation can impact herbivore ecology and this makes the identification of drivers challenging. Researchers have used diverse approaches to describe the association between environmental variation and ecology, including local weather, large-scale patterns of climate, and satellite imagery reflecting plant productivity and phenology. However, it is unclear to what extent it is possible to find a single measure that captures climatic effects over broad spatial scales. There may, in fact, be no a priori reason to expect populations of the same species living in different areas to respond in the same way to climate as their population may experience limiting factors at different times of the year, and the forms of regulation may differ among populations. Here, we examine whether the same environmental indices [seasonal Real Bioclimatic Index (RBI), seasonal Normalized Difference Vegetation Index (NDVI) and winter North Atlantic Oscillation (NAO)] influence body size in different populations of a large ungulate living in Mediterranean Spain, Western Scotland and Norway. We found substantial differences in the pattern of weight change over time in adult female red deer among study areas as well as different environmental drivers associated with variation in weight. The lack of general patterns for a given species at a continental scale suggest that detailed knowledge regarding the way climate affects local populations is often necessary to successfully predict climate impact. We caution against extrapolation of results from localized climate,population studies to broad spatial scales. [source] "It's All About Perspective": Using Simulations in Multicultural TeachingHISTORY COMPASS (ELECTRONIC), Issue 5 2006Kat Williams Many feminist pedagogues create a classroom climate that transforms the student from a passive beneficiary of knowledge to an active participant in the classroom community. This objective is accomplished in many different ways and while there is no way to ensure student participation in the classroom and not one technique that works for every situation, the common thread is the rejection of traditional, passive forms of learning in favor of alternative, active teaching methods. History is not experienced the same way by all people , it is not a seamless narrative or a single story, but a series of competing voices. To demonstrate my use of historical simulations in the classroom this article focuses on World War II and the alternative perspectives, including women's baseball, to which students are exposed and ultimately represent in the simulation. [source] Open versus laparoscopic resection for liver tumoursHPB, Issue 6 2009Thomas Van Gulik Abstract Background:, The issue under debate is whether laparoscopic liver resections for malignant tumours produce outcomes which are comparable with conventional, open liver resections. Methods:, Literature review on liver resection and laparoscopy. Results:, There are no randomized controlled trials (RCTs) published that provide any evidence for the benefits of laparoscopic liver resections for liver tumours. In case,control series reporting short-term outcomes, laparoscopic liver resection has been shown to have the advantage of a reduced length of hospital stay. There are as yet, however, no adequate long-term survival studies demonstrating that laparoscopic liver resection is oncologically equivalent to open resection. Discussion:, The challenge for the near future is to test the oncological integrity of laparoscopic liver resection in controlled trials in the same way that we have learned from the RCTs carried out in laparoscopic resection for colorectal cancer. It is likely that laparoscopic liver resection will then have to compete with fast-track, open liver resection. Already, concerns have been raised regarding the learning curve required to master the techniques of laparoscopic liver resection. [source] The role of training and technical assistance in supporting the delivery of high quality services in Early Head StartINFANT MENTAL HEALTH JOURNAL, Issue 1-2 2002Tammy L. Mann Training and technical assistance services have been an integral part of the fabric of support that Early Head Start (EHS) programs have utilized as they have worked to implement quality programs. In the same way that EHS has continued to evolve with increased program expansion, so too have the training and technical assistance support services. This article examines that nature of the early system of support and notes challenges that EHS programs faced during their first year of funding and the impact of these challenges on training and technical assistance support. The present day system is composed of a network of national and regional providers and federal staff working in partnership to support EHS programs. The nature of this network is described and recommendations for future areas of emphasis for training and technical assistance support are offered. ©2002 Michigan Association for Infant Mental Health. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||