bluuebunny/crossref_metadata_2025 huggingface dataset:
Discovery and characterization of human antibody inhibitors of pregnancy-associated plasma protein-A
Authors: Chen Ting , Hogan Shannon , Conley Greg , Pazmany Csaba , Wu Qi-Long , McNeil Gary L. , Bassill Gary , MacIntyre Andrew N. , Martik Diana , Nixon Andrew E. , Sexton Daniel J.
Published: May 2007

Pregnancy-associated plasma protein-A (PAPP-A) is a metalloprotease that cleaves insulin-like growth factor-binding proteins (IGFBPs) to release bioactive levels of free insulin-like growth factor. Specific and potent inhibitors of PAPP-A may further elucidate the biological functions of this protease and could prove to be of therapeutic value. Phage display was used to discover fully human antibody inhibitors of PAPP-A activity towards IGFBP4 cleavage. Estimates of the inhibition constants for these antibodies were subsequently determined using a novel continuous assay of PAPP-A protease activity that uses an internally quenched synthetic peptide substrate (DX-1655). DX-1655 was hydrolyzed by PAPP-A with a K
m of 33 μM and a k
cat of 0.3 s-1 (k
cat/K
m=9.1×103 M-1 s-1). PAPP-A activity towards DX-1655 displays a bell-shaped pH profile, with pK
a values of 8.2 and 10.8 and a maximum rate at approximately pH 9.5. Using this continuous assay, we measured apparent K
i values of 1.7±0.2 and 7.4±1.5 nM for the F2 and D9 antibodies, respectively.
Two α subunits and one β subunit of meprin zinc-endopeptidases are differentially expressed in the zebrafish Danio rerio
Authors: Schütte Andre , Lottaz Daniel , Sterchi Erwin E. , Stöcker Walter , Becker-Pauly Christoph
Published: May 2007

Meprins are members of the astacin family of metalloproteases expressed in epithelial tissues, intestinal leukocytes and certain cancer cells. In mammals, there are two homologous subunits, which form complex glycosylated disulfide-bonded homo- and heterooligomers. Both human meprin α and meprin β cleave several basement membrane components, suggesting a role in epithelial differentiation and cell migration. There is also evidence that meprin β is involved in immune defence owing to its capability of activating interleukin-1β and the diminished mobility of intestinal leukocytes in meprin β-knockout mice. Here we show for the first time by reverse transcription PCR, immunoblotting and immunofluorescence analyses that meprins are expressed not only in mammals, but also in the zebrafish Danio rerio. In contrast to the human, mouse and rat enzymes, zebrafish meprins are encoded by three genes, corresponding to two homologous α subunits and one β subunit. Observations at both the mRNA and protein level indicate a broad distribution of meprins in zebrafish. However, there are strikingly different expression patterns of the three subunits, which is consistent with meprin expression in mammals. Hence, D. rerio appears to be a suitable model to gain insight into the basic physiological functions of meprin metalloproteases.
Expression of the protein phosphatase 1 inhibitor KEPI is downregulated in breast cancer cell lines and tissues and involved in the regulation of the tumor suppressor EGR1 via the MEK-ERK pathway
Authors: Wenzel Katrin , Daskalow Katjana , Herse Florian , Seitz Susanne , Zacharias Ute , Schenk Jörg A. , Schulz Herbert , Hubner Norbert , Micheel Burkhard , Schlag Peter M. , Osterziel Karl J. , Ozcelik Cemil , Scherneck Siegfried , Jandrig Burkhard
Published: May 2007

KEPI is a protein kinase C-potentiated inhibitory protein for type 1 Ser/Thr protein phosphatases. We found no or reduced expression of KEPI in breast cancer cell lines, breast tumors and metastases in comparison to normal breast cell lines and tissues, respectively. KEPI protein expression and ubiquitous localization was detected with a newly generated antibody. Ectopic KEPI expression in MCF7 breast cancer cells induced differential expression of 95 genes, including the up-regulation of the tumor suppressors EGR1 (early growth response 1) and PTEN (phosphatase and tensin homolog), which is regulated by EGR1. We further show that the up-regulation of EGR1 in MCF7/KEPI cells is mediated by MEK-ERK signaling. The inhibition of this pathway by the MEK inhibitor UO126 led to a strong decrease in EGR1 expression in MCF7/KEPI cells. These results reveal a novel role for KEPI in the regulation of the tumor suppressor gene EGR1 via activation of the MEK-ERK MAPK pathway.
“Taking the piss”: Functions of banter in the IT industry
Authors: Plester Barbara A , Sayers Janet
Published: May 2007

This paper shows how banter helps forge organizational culture by facilitating socialization of work group members and presents original research conducted in three IT companies. Informants identified their style of humor as “taking the piss,” a colloquial term meaning to use jocular abuse to deflate someone else's ego to bring them to the same level as others. The IT organizations studied were young, creative and energetic and the banter was lively and almost always enjoyed. Six main functions of banter were identified: making a point, boredom busting, socialization, celebrating differences, displaying the culture, and highlighting and defining status. Banter occurred more readily when it involved popular and well-liked colleagues that were fully socialized into the organizational culture. Personal characteristics and traits—such as ethnicity, gender, age, height or dress style—were the target of much banter. Much of the literature discussing banter has focused on the negative effects of jocular abuse at work. This paper emphasises how banter helped facilitate functioning cultural systems in the organizations studied. However, for those not socialized through the banter into the in-group, banter was often experienced as painful, exclusionary and even insulting.
Temporal and spatial variation of physical, biological, and chemical parameters in a large waste stabilisation pond, and the implications for WSP modelling
Authors: Sweeney D.G. , Nixon J.B. , Cromar N.J. , Fallowfield H.J.
Published: May 2007

The spatial and temporal variation of physical, chemical, and biological parameters was determined, in summer and winter, at nine sites in a large (112 ha) waste stabilisation pond (WSP) at the Bolivar Wastewater Treatment Plant. Each site was extensively sampled over the course of one day, with the nine sites sampled over successive days at exactly the same times of day, progressing in the direction of bulk flow through the pond. Analyses of covariance were used to test the independent impact of site and climate on the way in which the mean values and stratification gradient of the physical, chemical, and biological parameters varied diurnally at each site. In both winter and summer studies there was a very strong correlation at all sites between changes in temperature, pH and dissolved oxygen (DO). Mean pond temperatures were higher in summer than winter, and thermal stratification was more common in summer. In summer, during the day at each site, concentrations of chlorophyll-a, DO, suspended solids and pH increased with higher solar radiation levels. This relationship was less evident in winter. There was no systematic depth or temporal variation identified in either the summer or winter study for the broad range of chemical parameters measured. Mean values for these parameters, and to a lesser extent their stratification gradients, increased by varying extents throughout the day at the different sites in both summer and winter, irrespective of changes in climate when the different sites were sampled. Sites nearer the inlet to the WSP recorded lower NH4N and higher NO2N and NO3N concentrations than the rest of the WSP. This was indicative of nitrification. Somewhat surprisingly, high DO concentrations were also recorded at these sites near the inlets. Computational fluid dynamics (CFD) modelling, incorporating the predominant wind conditions, offers a rationale for these observations. Recirculation was evident, which may increase the residence time for the slow growing autotrophic nitrifying bacteria and recirculate oxygen rich water around these sites — conditions which would enhance nitrification. Understanding the effect of these variations, overlaid by the influence of hydraulic and temporal scenarios, assists in developing a mechanistic understanding of pond operation.
Physical and hydrodynamic characteristics of a dairy shed waste stabilisation pond system
Authors: Fyfe J. , Smalley J. , Hagare D. , Sivakumar M.
Published: May 2007

Waste stabilization pond systems are widely used to treat animal wastes under highly variable hydraulic loading regimes. These systems have received limited research attention with regard to their hydrodynamic behaviour and the potential impact of shock hydraulic loading on their performance. In this study a two-stage dairy shed waste stabilisation pond system was topographically surveyed to determine the physical shape and the theoretical hydraulic retention time (HRT) of each pond, as well as the extent of sludge accumulation in the primary pond. The primary pond was then subjected to a series of drogue tracking runs whereby weighted floating survey targets with submerged ‘sails’ were tracked during their movement through the pond at times of peak flow in order to characterise the hydrodynamic behaviour of the pond. The full capacity volumes of the primary and secondary ponds were calculated to be 1285 m3 and 2391 m3, respectively. Sludge had been accumulating in the primary pond at a rate of 0.73 m3/d over a period of 2.4 years and this has reduced the active treatment volume of the pond to 657 m3. Based on mean outflow, the HRTs of the ponds were 40 d and 137 d, respectively. The drogue runs revealed a vortex-like mixing pattern within the pond with higher velocities around the perimeter of the pond between the inlet and outlet, and lower velocities in the centre of the pond. In-pond velocities seemed relatively high in comparison with those from other drogue studies of larger ponds and the surging inflow caused the formation of a flow ‘jet’ that potentially contributed to significant short-circuiting. The range of influence of this flow jet, however, was limited to within 15 m of the inlet, suggesting that short-circuiting would be likely to occur only under certain high inflow conditions.
Dynamic variation of supernatant quality in a dairy shed waste stabilisation pond system
Authors: Fyfe J. , Sivakumar M. , Hagare D. , Jenkins A.
Published: May 2007

An intensive monitoring program of a standard two-stage dairy shed waste stabilisation pond system was undertaken to determine the incidence and extent of spatial and temporal variation of basic physio-chemical parameters, and to shed light on the longer term dynamic nature of in-pond conditions. The anaerobic–facultative pond system, located in a remote rural area, treats wastewater from the hosing down and hydraulic flushing of the milking parlour and holding yard at the farm dairy shed. A number of multi-parameter water quality field monitoring probes were permanently deployed at various locations within the two ponds to enable continuous measurement of temperature, pH, conductivity and dissolved oxygen. In addition, profiling of the supernatant of both ponds was undertaken at different times of the year to examine vertical variation of the same parameters. Continuous monitoring revealed spatial homogeneity in EC and pH levels in the upper metre of both ponds. Physio-chemical parameters also appear to change uniformly across the ponds in response to external stimuli such as rainfall. Neither pond, however, exhibits homogeneity down the profile of the supernatant. Seasonal stratification is prevalent in the facultative pond suggesting poor vertical mixing, while the anaerobic pond is notably affected by sludge accumulation. A long-term pattern of rising conductivity in both ponds indicated accumulation of dissolved salt species in the system due to recirculation of reclaimed effluent for hydraulic flushing of the dairy shed. In the facultative pond, diurnal fluctuations in dissolved oxygen, oxidation-reduction potential and turbidity during warmer months of the year closely followed temperature swings. The extensive data collected in this study provides a detailed picture of the physio-chemical dynamics of two-stage stabilisation pond systems treating dairy shed wastewater.
Ammonia and phosphorus removal in polishing ponds: a case study in Southeast Brazil
Authors: Bastos R.K.X. , Rios E.N. , Dornelas F.L. , Assunção F.A.L. , Nascimento L.E.
Published: May 2007

Ammonia and phosphorus removal were evaluated over four years monitoring of an experimental wastewater treatment plant in Brazil: initially a UASB reactor (real scale) + three shallow polishing ponds (pilot scale), afterwards a UASB + submerged aerated biofilter (BF) (real scale) + the same pond series. Shallow ponds (h < 0.90m) provided considerable ammonia removal, but phosphorus removal was somewhat poorer. An equation was derived for the estimation of ammonia pond effluent, based on the same assumptions of the well known Pano and Middlebrooks model. According to the experimental data, an effluent suitable for aquaculture should be achieved with retention time of 25 days.
Canal networks as extended waste stabilization ponds: fate of pathogens in constructed waterways in Pathumthani Province, Thailand
Authors: Anceno A.J. , Ozaki M. , Dang Y.N.D. , Chuluun B. , Shipin O.V.
Published: May 2007

The occurrence and fate of surface water and wastewater pathogens (faecal coliforms, Escherichia coli, Giardia lamblia and Cryptosporidium parvum) in two constructed waterways and a pond-based AIT wastewater treatment plant (AIT WWTP) in Pathumthani, Thailand were studied in the context of several biogeochemical factors and in relation to pollutional pressure and seasonal phenomena with a view to proposing potential mechanisms for their removal. More data on pathogen removal in a given local context would provide assurance that some pathogens could serve as suitable indicator organisms and predict removal of different pathogenic microorganisms such as protozoan parasites covered in this study. The enumeration technique for protozoan pathogens was improved in terms of application of emerging novel molecular technologies for the development of a fast but affordable microbiological method. Potential risk of waterborne disease outbreak in pertinent communities was then characterized using established infection probability models and the compiled pathogen occurrence data. Overall, we have addressed several strategic priorities of pathogen research in waste stabilization ponds in developing tropical countries like Thailand.
Fate of endocrine disrupters in waste stabilization pond systems
Authors: Gomez E. , Wang X. , Dagnino S. , Leclercq M. , Escande A. , Casellas C. , Picot B. , Fenet H.
Published: May 2007

The performance in the removal of estrogenicity from wastewater was studied in three wastewater treatment plants (WWTPs). Different treatment processes were evaluated: stabilization ponds and trickling filter. Sampling was performed from the input to the output of the treatment systems. The total estrogenic activity was determined with MCF-7-derived cell lines which express the endogenous estrogen receptor α. The two wastewater stabilization ponds with long retention time had high removal of estrogenicity (90% to 95%). Trickling filters despite being effective at removing organic load were less effective in removing estrogenicity (42%), and post tertiary ponds enhanced estrogenicity removal.
Symbiotic algal bacterial wastewater treatment: effect of food to microorganism ratio and hydraulic retention time on the process performance
Authors: Medina M. , Neis U.
Published: May 2007

Algal incorporation into the biomass is important in an innovative wastewater treatment that exploits the symbiosis between bacterial activated sludge and microalgae (Chlorella vulgaris sp. Hamburg). It allows a good and easy algae separation by means of clarification. The effect of process parameters food to microorganisms ratio (F/M) and hydraulic retention time (HRT) on the process performance, evaluated by settleability, microalgae incorporation to biomass and nutrient removal, was studied. HRT hinted at a significant influence in the growth rate of algae, while F/M turned out to be important for stability when algae are incorporated into the biomass. This parameter also affects the total nitrogen removal of the treatment. Stable flocs with incorporated algae and supernatants with low free swimming algae concentrations were obtained at high HRT and low F/M values.
Improvement of oxygen transfer efficiency in aerated ponds using liquid-film-assisted approach
Authors: Zhu H. , Imai T. , Tani K. , Ukita M. , Sekine M. , Higuchi T. , Zhang Z.
Published: May 2007

In aerated ponds, oxygen is generally supplied through either diffused or mechanical aeration means. Surface transfer and bubble transfer both contribute significantly to oxygen transfer in a diffused aeration system. In the present study, a liquid-film-forming apparatus (LFFA) is successfully developed on a laboratory scale to improve considerably the surface transfer via the unique liquid film transfer technique. The experimental results show that the volumetric mass transfer coefficient for LFFA alone is found to be as much as 5.3 times higher than that for water surface and that the total volumetric mass transfer coefficient for the liquid film aeration system increases by 37% in comparison with a conventional aeration system. Additionally, by tuning finely the structural parameters of the LFFA, it can also lead to high dissolved oxygen (DO) water with the DO percent saturation greater than 90%. More importantly, this result is accomplished by simply offering a single-pass aeration at a depth as shallow as 26 cm. As a result, the objective of economical energy consumption in aerated ponds can be realized by lowering the aeration depth without sacrificing the aeration efficiency. It is noteworthy that the data presented in this study are acquired either numerically or experimentally.
Biogas production from anaerobic waste stabilisation ponds treating dairy and piggery wastewater in New Zealand
Authors: Park J.B.K. , Craggs R.J.
Published: May 2007

New Zealand has over 1000 anaerobic wastewater stabilisation ponds used for the treatment of wastewater from farms and industry. Traditional anaerobic ponds were not designed to optimise anaerobic digestion of wastewater biomass to produce biogas and these uncovered ponds allowed biogas to escape to the atmosphere. This release of biogas not only causes odour problems, but contributes to GHG (greenhouse gas) emissions and is wasteful of energy that could be captured and used. Biogas production from anaerobic stabilisation ponds treating piggery and dairy wastewater was measured using floating 25 m2 HDPE covers on the pond surface. Biogas composition was analysed monthly and gas production was continually monitored. Mean areal biogas (methane) production rates from piggery and dairy anaerobic ponds were 0.78 (0.53) m3/m2/d and 0.03 (0.023) m3/m2/d respectively. Average CH4 content of the piggery and dairy farm biogas were 72.0% and 80.3% respectively. Conversion of the average volume of methane gas that could be captured from the piggery and dairy farm ponds (393.4 m3/d and 40.7 m3/d) to electricity would reduce CO2 equivalent GHG emissions by 5.6 tonnes/d and 0.6 tonnes/d and generate 1,180 kWh/d and 122 kWh/d. These results suggest that anaerobic ponds in New Zealand release considerable amounts of GHG and that there is great potential for energy recovery.
Maturation ponds, rock filters and reedbeds in the UK: statistical analysis of winter performance
Authors: Johnson M. , Camargo Valero M.A. , Mara D.D.
Published: May 2007

Wastewater treatment technologies suitable for serving large populations are generally reliable and reasonably cost-effective, yet they are almost always financially inappropriate for small communities (<2,000 p.e.). Comparative cost data suggests that waste stabilization ponds should be an attractive option for small communities, yet perceptions relating to land costs, climate and effluent quality have limited their application in the UK. This paper details typical UK land costs, climate and winter performance data for a pilot-scale waste stabilization pond with various upgrading technologies: system A, two tertiary maturation ponds in series; B, two tertiary maturation ponds in series followed by a reed bed channel; C, a control rock filter; D, an aerated rock filter; and E, a constructed wetland. System D was found to perform best, closely followed by system B.
Algal growth response and survival in a range of light and temperature conditions: implications for non-steady-state conditions in waste stabilisation ponds
Authors: Bartosh Y. , Banks C.J.
Published: May 2007

Growth and physiological experiments were carried out using Scenedesmus subspicatus and Chlorella vulgaris as representative species typically found in waste stabilisation ponds. These experiments were designed to test the ability of the organisms to survive and grow under a range of different temperatures and light intensities that might occur in mid to high latitude regions. Growth was assessed using optical density and photosynthetic rate for a combination of temperatures of 5, 10, 15 and 20 °C at light intensities of 7.8, 15.7, 31.3, 47, 62.7 and 78.3 μmol m−2 sec−1. C. vulgaris had a higher rate of growth and photosynthetic activity than S. subspicatus at low temperatures but had reached its maximum growth rate at 15 °C. S. subspicatus showed a higher growth rate than C. vulgaris at higher temperatures, and did not achieve its maximum growth rate over the range of temperatures studied. For both species light was not limiting to growth above 47 μmol m−2 sec−1. Survival of the two species under dark conditions was tested at 4 °C and −20 °C using direct plating and growth tests. C. vulgaris was able to survive at 4 °C for a much longer period than S. subspicatus and a portion of the population was able survive −20 °C. The different responses of the two species to dark and cold conditions are indicative of the range that may occur across a wider population, and show why in practice some species may appear earlier and compete more effectively in early spring but then lose advantage as the temperature and light intensity increases into the summer.
Integrated advanced natural wastewater treatment system for small communities
Authors: Surampalli R.Y. , Banerji S.K. , Tyagi R.D. , Yang P.Y.
Published: May 2007

A study was conducted to evaluate the nutrient removal capability of an existing and successfully operated overland flow and wetland wastewater treatment system following a waste stabilization pond. Seasonal temperature effects on performance were also investigated. The treatment system studied consists of a two-cell waste stabilization pond followed by an overland flow system and a wetland system. The influent and effluent samples were analyzed for BOD5, suspended solids (SS), pH, temperature, ammonia nitrogen, nitrate nitrogen, and total phosphorus. The results of the study indicate that the combined pond, overland flow and wetland system provided excellent treatment of municipal wastewater. The overall average BOD5 removal by the entire treatment system was about 90.0% and the overall average suspended solids removal was about 93.4%. The ammonia nitrogen and total phosphorus removal efficiencies of the entire treatment system were 90.7% and 84.2%, respectively.
The Inverted “U-Shaped” Dose-Effect Relationships in Learning and Memory: Modulation of Arousal and Consolidation
Authors: Baldi Elisabetta , Bucherelli Corrado
Published: May 2007

In the ample field of biological non-linear relationships there is also the inverted U-shaped dose-effect. In relation to cognitive functions, this phenomenon has been widely reported for many active compounds, in several learning paradigms, in several animal species and does not depend on either administration route (systemic or endocerebral) or administration time (before or after training). This review summarizes its most interesting aspects. The hypothesized mechanisms supporting it are reported and discussed, with particular emphasis on the participation of emotional arousal levels in the modulation of memory processes. Findings on the well documented relationship between stress, emotional arousal, peripheral epinephrine levels, cerebral norepinephrine levels and memory consolidation are reported. These are discussed and the need for further research is underlined.
Hormetic Influence of Glucocorticoids on Human Memory
Authors: Lupien Sonia J. , Buss Claudia , Schramek Tania E. , Maheu Francoise , Pruessner Jens
Published: May 2007

In this paper, we discuss the effects of glucocorticoids on human learning and memory using the recent model of hormesis proposed by Calabrese and collaborators. Although acute increases in glucocorticoids have been shown to impair memory function in humans, other studies report no such impairments or, in contrast, beneficial effects of acute glucocorticoid increases on human memory function. We summarize these studies and assess whether the wealth of data obtained in humans with regard to the effects of acute increase of glucocorticoids on human cognition are in line with a hormetic function. We then discuss several factors that will have to be taken into account in order to confirm the presence of a hormetic function between glucocorticoids and human cognitive performance.
The Relationship between Acute Glucocorticoid Levels and Hippocampal Function Depends upon Task Aversiveness and Memory Processing Stage
Authors: Conrad Cheryl D.
Published: May 2007

This review evaluates the effects of glucocorticoids (GCs), the adrenal steroids released in response to stress, on memory functions requiring the hippocampus in animals and humans. The data support the hypothesis that the learning function between GCs and hippocampal-dependent memory is modulated by 1) the aversive nature of the learning paradigm and 2) stage of memory processing (acquisition, consolidation, retrieval). When tasks are minimally aversive, the glucocorticoid receptor (GR) mediates an inverted U-shaped relationship between GC levels and hippocampal function, while the mineralocorticoid receptor (MR) mediates attentional processes and/or reaction to novelty. This inverted U-shaped relationship during minimally aversive training paradigms describes GC-mediated memory processing at both acquisition and consolidation. In contrast, highly aversive paradigms activate the amygdala and elevate GCs as part of the training procedure, revealing a nonlinear inverted U-shaped relationship during acquisition and a positive linear function during consolidation. Thus, highly aversive tasks that activate the amygdala shift the memory function from an inverted U-shaped curve to a linear representation between GC levels and memory consolidation.
The Involvement of Calcium in the Protective and Toxic (Nonlinear) Responses of Rodent and Human Astroglial Cells
Authors: Slamon N. Debbie , Mead Carole , Morgan Chris , Mitchell Andy , Pentreath Vic W.
Published: May 2007

The involvement of [Ca2+]i in the reactive changes of astrocytes which accompany exposure to different chemicals were studied in cultures of C6 and 1321N1 cells. Cells were exposed to up to three serial pulses of the differentiating agent dBcAMP, which induces activation-type changes in the cells. Other cells, with or without the dBcAMP treatments, were treated with a range of concentrations of the antidepressants amitriptyline and fluoxetine and the glial toxicants acrylamide and chloroquine. In some experiments the L-type voltage calcium channel blocker Nifedipine was employed. [Ca2+]i was measured in populations of the cells using Fura-2AM and a charge coupled device (CCD) camera attached to a fluorescence microscope. dBcAMP induced both dose- and time-dependent changes in [Ca2+]i with increases in both the [Ca2+]i oscillations and mean [Ca2+]i (e.g. in C6 cells at 18 min mean [Ca2+]i was 318 ± 20nM following the single differentiating dBcAMP pulses, 489 ± 17nM (p < 0.001) following two serial pulses, and 275 ± 30nM (not significant) following three pulses). Therapeutic doses of fluoxetine and amitriptyline caused increases in the calcium oscillations and the mean calcium concentrations (maximum recorded mean increase was in the C6 cells at 10min by 0.02 μM fluoxetine when [Ca2+]i was 411 ± 35nM c.f. control 254 ± 25nM, p = 0.01). Higher (non-therapeutic) doses of both antidepressants caused significant reductions. Chloroquine and acrylamide also caused dose-dependent bi-phasic types of alterations in [Ca2+]i, with significant reductions at lower, sub-cytotoxic doses followed by significant increases at higher concentrations, approaching those which cause cell damage. Nifedipine treatment caused some reductions in the dBcAMP, antidepressant or toxicant-induced calcium changes, but this substance also initiated cytotoxic alterations. The findings show that both the activation-type changes (which are frequently associated with increased protective capacities) and toxic responses of C6 and 1321N1 cells to different chemical agents are associated with dose-dependent alterations in [Ca2+]i.
Low Dose Effects in Psychopharmacology: Ontogenetic Considerations
Authors: Spear Linda Patia , Varlinskaya Elena I.
Published: May 2007

Low doses of psychoactive drugs often elicit a behavioral profile opposite to that observed following administration of more substantial doses. Our laboratory has observed that these effects are often age-specific in rats. For instance, whereas moderate to high doses of the dopamine agonist apomorphine increase locomotion, suppressed locomotor activity is seen following low dose exposure, with this low dose effect not emerging consistently until adolescence. A somewhat earlier emergence of a low dose “paradoxical” effect is seen with the 5HT1a receptor agonist, 8-OH-DPAT, with late preweanling, but not neonatal, rats showing increases in ingestive behavior at low doses but suppression at higher doses. In contrast to these ontogenetic increases in expression of low dose drug effects, low dose facilitation of social behavior is seen following ethanol only in adolescent rats and not their mature counterparts, although suppression of social interactions at higher doses is seen at both ages. This hormesis-like low dose stimulation appears related in part to overcompensation, with brief social suppression preceding the subsequent stimulation response, and also bears a number of ontogenetic similarities to acute tolerance, a well characterized, rapidly emerging adaptation to ethanol. Implications of these and other ontogenetic findings for studies of hormesis are discussed.
Nonlinear Response for Neoplastic Transformation following Low Doses of Low Let Radiation
Authors: Redpath J. Leslie
Published: May 2007

There are now several independent studies that indicate that the dose-response for the endpoint of radiation-induced neoplastic transformation in vitro is non-linear for low linear energy transfer (LET) radiation. At low doses (<10 cGy) the transformation frequency drops below that seen spontaneously. Importantly, this observation has been made using fluoroscopic energy x-rays, a commonly used modality in diagnostic radiology, the practice of which is responsible for the majority of radiation exposure to the general public. Since the transformation frequency is reduced over a large dose range (0.1 to 10cGy) it is likely that multiple mechanisms are involved and that the relative contribution of these may vary with dose. These include the killing of a subpopulation of cells prone to spontaneous transformation at the lowest doses, and the induction of DNA repair at somewhat higher doses. Protective effects of low doses of low LET radiation on other cancer-relevant endpoints in vitro and in vivo have also been observed by several independent laboratories. These observations strongly suggest that the linear-nonthreshold dose-response model is unlikely to apply to the induction of cancer by low doses of low LET radiation in humans.
The Search for Non-Linear Exposure-Response Relationships at Ambient Levels in Environmental Epidemiology
Authors: Lippmann Morton
Published: May 2007

Environmental exposures to ambient air particulate matter (PM), ozone (O3), environmental tobacco smoke (ETS), and to dioxin and related compounds are of considerable public health concern, and risk assessments for them have generally been based on linear, non-threshold models derived from epidemiological study data. While the epidemiological databases for PM, O3, and ETS have been sufficient to show that adverse health effects are occurring, the relative risks have been quite low, and it has not been possible, to date, to identify thresholds or non-linear relationships for them. For dioxin and related compounds, the evidence for excess cancer risks has been inadequate to establish causality, and there is suggestive evidence that hormesis may have occurred.
Mathematical Modelling of Allelopathy: IV. Assessment of Contributions of Competition and Allelopathy to Interference by Barley
Authors: Li Liu De , An Min , Johnson I.R. , Lovett J.V.
Published: May 2007

One of the main challenges to the research on allelopathy is technically the separation of allelopathic effect from competition, and quantitatively, the assessment of the contribution of each component to overall interference. A simple mathematical model is proposed to calculate the contribution of allelopathy and competition to interference. As an example of applying the quantitative model to interference by barley ( Hordeum vulgare cv. Triumph), the approach used was an addition of allelopathic effect, by an equivalent amount, to the environment of the test plant (white mustard, Sinapis alba), rather than elimination of competition. Experiments were conducted in glasshouse to determine the magnitude of the contributions of allelopathy and competition to interference by barley. The leachates of living barley roots significantly reduced the total dry weight of white mustard. The model involved the calculation of adjusted densities to an equivalent basis for modelling the contribution of allelopathy and competition to total interference. The results showed that allelopathy contributed 40%, 37% and 43% to interference by barley at 6, 12 and 18 white mustard pot−1. The consistency in magnitude of the calculated contribution of allelopathic effect by barley across various densities of receiver plant suggested that the adjusted equivalent density is effective and that the model is able to assess the contribution of each component of interference regardless of the density of receiver plant.
Semantic description in MPEG‐7: The rich recursion of ripeness
Authors: Rising III Hawley K. , Jörgensen Corinne
Published: May 2007

Metadata describing multimedia can address a wide variety of purposes, from the purely physical characteristics of an item, to the circumstances surrounding its production, to attributes that cannot necessarily be determined by examining the item itself directly. These latter attributes, often dealing with “meaning” or interpretation of an item's content, are frequently deemed too difficult to determine and subject to individual and cultural variability. At the same time, however, research has shown that these abstract, interpretive attributes, which carry meaning, are frequently the ones for which people search. To describe an item fully, therefore, means to describe it at both the “syntactic” and the “semantic” levels. This article discusses the development of the semantic description schemes within the MPEG‐7 standard from both a historical and an intellectual perspective, as well as the difficulties inherent in creating a descriptive schema that can fully capture the complexity of “narrative worlds.”
Automatic user preference learning for personalized electronic program guide applications
Authors: Lim Jeongyeon , Kang Sanggil , Kim Munchurl
Published: May 2007

In this article, we introduce a user preference model contained in the User Interaction Tools Clause of the MPEG‐7 Multimedia Description Schemes, which is described by a UserPreferences description scheme (DS) and a UsageHistory description scheme (DS). Then we propose a user preference learning algorithm by using a Bayesian network to which weighted usage history data on multimedia consumption is taken as input. Our user preference learning algorithm adopts a dynamic learning method for learning real‐time changes in a user's preferences from content consumption history data by weighting these choices in time. Finally, we address a user preference–based television program recommendation system on the basis of the user preference learning algorithm and show experimental results for a large set of realistic usage‐history data of watched television programs. The experimental results suggest that our automatic user reference learning method is well suited for a personalized electronic program guide (EPG) application.
Enabling MPEG‐7 structural and semantic descriptions in retrieval applications
Authors: Benitez Ana B. , Zhong Di , Chang Shih‐Fu
Published: May 2007

The MPEG‐7 standard supports the description of both the structure and the semantics of multimedia; however, the generation and consumption of MPEG‐7 structural and semantic descriptions are outside the scope of the standard. This article presents two research prototype systems that demonstrate the generation and consumption of MPEG‐7 structural and semantic descriptions in retrieval applications. The active system for MPEG‐4 video object simulation (AMOS) is a video object segmentation and retrieval system that segments, tracks, and models objects in videos (e.g., person, car) as a set of regions with corresponding visual features and spatiotemporal relations. The region‐based model provides an effective base for similarity retrieval of video objects. The second system, the Intelligent Multimedia Knowledge Application (IMKA), uses the novel MediaNet framework for representing semantic and perceptual information about the world using multimedia. MediaNet knowledge bases can be constructed automatically from annotated collections of multimedia data and used to enhance the retrieval of multimedia.
Co‐determination of ATP and proteins in Triton X 100 non‐ionic detergent‐opened monolayer cultured cells
Authors: Kőszegi Tamás , Petrik József , Vladimir‐Knežević Sanda , Nagy Sándor
Published: May 2007

Human monolayer cells (HEp‐2 and Hep G2) were cultured in 96‐well plates. A modified Triton X 100 nonionic detergent extraction method was used for releasing intracellular ATP and protein in one step. The detergent technique was compared to perchloric acid (PCA) extraction. ATP was determined by the firefly bioluminescence method and ATP values were referred to cell protein (ATP:protein ratio). There was no significant difference in ATP data between detergent and PCA treatments. The ATP:protein ratio seems to be a sensitive tool for characterizing the metabolic activity of monolayer tissue culture cells. The protein‐mobilizing capability of Triton X 100 depends on the type of cell culture used. Our modified extraction gives reliable ATP:protein values with one simple extraction step. Copyright © 2007 John Wiley & Sons, Ltd.
Studien in der heterocyclischen Reihe. I. Mitteil.: Eine neue Synthese der 2.4‐Diamino‐6‐alkyl‐5‐aryl‐pyrimidine („Daraprim”︁)
Authors: Logemann Willy , Almirante Luigi , Caprio Lorenzo
Published: May 2007

Das von P. B. Russell und G. H. Hitchings1) vor kurzem für die Therapie der Malaria dargestellte 2.4‐Diamino‐6‐äthyl‐5‐p‐chlorphenyl‐pyrimidin („Daraprim”︁) wird aus α‐Propionyl‐α‐p‐chlorphenyl‐acetonitril und Guanidin über eine Amin‐natrium‐Verbindung des Nitrils synthetisiert. Des weiteren werden einige analoge Synthesen ähnlicher Produkte beschrieben.
Über das Indolo‐(2.3‐b)‐carbazol und weitere Umsetzungsprodukte der Diindolyl‐(3.3′)‐methane (II. Mitteil. zur Chemie des Indols)
Authors: Von Dobeneck Henning , Maas Ingeborg
Published: May 2007

Indol und Diindolyl‐(3.3′)‐methane mit freien α‐Stellungen reagieren mit Aldehyden unter Bildung von 5.6.7.12‐Tetrahydro‐indolo‐(2.3‐b)‐carbazolen, während α‐substituierte Diindolyl‐(3.3′)‐methane unter gleichen Bedingungen eine Aufspaltung zu einkernigen Indoleninderivaten erfahren. Auch im Verhalten gegenüber Ketonen zeigt sich ein grundlegender Unterschied zwischen Diindolyl‐(3.3′)‐methanen mit freien und solchen mit besetzten α‐Stellungen. Letztere bilden mit Ketonen asymmetrische Indolyl‐indolenyl‐äthan‐Derivate.
Das Cornubertsche Isomere des 1.3‐Dibenzal‐cyclopentanons‐(2)
Authors: Wanzlick Hans‐Werner , Menz Wolfgang
Published: May 2007

Das von R. Cornubert erhaltene Isomere des 1.3‐Dibenzal‐cyclopentanons‐(2) wird als 2‐Benzyl‐4‐benzal‐cyclopenten‐(1)‐on‐(3) erkannt. Die Darstellung gelingt auf neuem Wege.
Über bi‐homologe Reihen (VII. Mitteil. über isomere und homologe Reihen*)
Authors: Breusch Friederich L.
Published: May 2007

Neun bi‐homologe Reihen, teilweise bis zu einer Alkylkettenlänge von zweimal 20 Kohlenstoff‐Atomen, wurden synthetisiert. Der Verlauf der Schmelzpunktskurven dieser bihomologen Reihen wird besprochen.
β‐Aminosäuren, V. Mitteil.: Isomerieerscheinungen der γ‐Methylmercapto‐crotonsäure; eine vereinfachte Darstellung von β‐Methionin
Authors: Birkofer Leonhard , Hartwig Ingeborg
Published: May 2007

Die bisher nur schlecht zugängliche γ‐Methylmercapto‐crotonsäure wurde durch Umsetzung von γ‐Brom‐crotonsäureester mit Methylmercaptan und tertiären Aminen in guter Ausbeute gewonnen. Beim Verseifen des γ‐Methylmercapto‐crotonsäureesters mit Barytwasser entsteht neben der gewünschten Säure durch Isomerisierung die γ‐Methylmercapto‐vinylessigsäure, die teilweise Ringschluß zum γ‐Methylmercapto‐γ‐butyrolacton erleidet. Durch Variation der Versuchs‐bedingungen konnte die Ausbeute an d,l‐β‐Methionin beim Anlagern von Ammoniak an γ‐Methylmercapto‐crotonsäure von 18% auf 64% erhöht werden.
Über Thiazole, XX. Mitteil.): Die wahre Konstitution des in der Literatur beschriebenen, 2‐Amino‐5‐methyl‐1.3.4‐thiodiazins
Authors: Beyer Hans , lässig Wolfgang , Bulka Ehrenfried
Published: May 2007

Der von J. McLean und F. J. Wilson1) für, 2‐Amino‐5‐methyl‐1.3.4‐thiodiazin gehaltenen Verbindung kommt die Konstitution des 3‐Amino‐4‐methyl‐thiazolon‐(2)‐imids (IV) zu. Demgegenüber liegt in der von uns dargestellten und in der XV. Mitteil.2) als, 3‐Amino‐4‐methyl‐thiazolon‐(2)‐imid bezeichneten Verbindung das eigentliche 2‐Amino‐5‐methyl‐1.3.4‐thiodiazin (II) vor.

Der Konstitutionsbeweis für das 3‐Amino‐4‐methyl‐thiazolon‐(2)‐imid konnte durch Überführung in eine Nitrosoverbindung des 2‐Amino‐4‐methyl‐thiazols erbracht werden.

Bei der Kondensation von Chloraceton mit Thiosemicarbazid‐hydrochlorid in wäßriger bzw. 1 bis 2 n salzsaurer Lösung entsteht fast quantitativ das Chloraceton‐thiosemicarbazon, das sich beim Erwärmen in alkoholischer Lösung zum 2‐Amino‐5‐methyl‐1.3.4‐thiodiazin (II) cyclisiert. Dieses lagert sich unter dem Einfluß starker Salzsäure unter Ringverengung in das 3‐Amino‐4‐methyl‐thiazolon‐(2)‐imid (IV) und beim Erhitzen mit Benzaldehyd in alkoholischer Lösung in die Benzalverbindung des 4‐Methyl‐thiazolyl‐(2)‐hydrazins (III) um.

Für den Reaktionsverlauf der obigen Kondensationen werden in Abhängigkeit von der Acidität des Mediums drei verschiedene Wege diskutiert. Außerdem erfahren die in der XV. Mitteil.2) angeführten Cyclisierungsreaktionen und intramolekularen Umlagerungen eine andere theoretische Deutung.
Über Thiazole, XXII. Mitteil.): Über das 2‐Hydrazino‐5‐methyl‐1.3.4‐thiodiazin und dessen Umlagerung in das 3‐Amino‐4‐methyl‐thiazolon‐(2)‐hydrazon
Authors: Beyer Hans , Läussig Wolfgang , Schultz Ulrich
Published: May 2007

Die Kondensation von Chloraceton mit Thiocarbohydrazid führt in 2n salzsaurer Lösung zum Mono‐chloraceton‐thiocarbohydrazon, das beim Erhitzen in alkoholischer Lösung zum 2‐Hydrazino‐5‐methyl‐1.3.4‐thiodiazin cyclisiert wird. Dieses lagert sich bei der Einwirkung von konz. Salzsäure intramolekular in das 3‐Amino‐4‐methyl‐thiazolon‐(2)‐Hydrazon um. Ebenso geht die Monobenzal‐Verbindung des 2‐Hydrazino‐5‐methyl‐1.3.4‐thiodiazins auf Zugabe von 2nHCl in der Hitze unter Ringverengung in das strukturisomere Benzaldehyd‐[3‐amino‐4‐methyl‐thiazolon‐(2)]‐azin über. Aus diesem erhält man mit Benzaldehyd eine Dibenzal‐Verbindung, die andererseits auch aus dem 3‐Amino‐4‐methyl‐thiazolon‐(2)‐hydrazon mit 2 Moll. Benzaldehyd darstellbar ist.

Die Konstitution des 3‐Amino‐4‐methyl‐thiazolon‐(2)‐hydrazons wurde durch Desaminierung der N‐Aminogruppe in 3‐Stellung des Benzaldehyd‐[3‐amino‐4‐methyl‐thiazolon‐(2)]‐azins mit 2 Moll. Salpetriger Säure bewiesen. Hierbei findet gleichzeitig Nitrosierung in 5‐Stellung des Thiazolkerns unter Bildung von Benzaldehyd‐[4‐methyl‐5‐nitroso‐thiazolyl‐(2)]‐hydrazon statt, das in Laugen löslich ist.
Darstellung von Polycarbonsäuren, II. Mitteil.): Die Aufspaltung des α‐substituierten Tetrahydrofuran‐Ringes in der Alkalischmelze
Authors: Runge Franz , Hueter Richard , Wulf Horst‐Dieter
Published: May 2007

α‐Tetrahydrofuryl‐alkohole werden in der Alkalischmelze zu ω, ω'‐Dicarbonsäuren aufgespalten. Der Reaktionsmechanismus wird aufgeklärt.
Über γ‐Pyrone und γ‐Pyridone, III. Mitteil.): Carbonsäure‐Derivate von γ‐Pyronen und γ‐Pyridonen
Authors: Heyns Kurt , Vogelsang Gerhard
Published: May 2007

Es werden Synthesen von Pryridon‐(4)‐carbonsäure‐(2)‐hydrazid und von dessen 5‐Oxy‐ und 5‐Alkoxy‐Derivaten beschrieben.
Eine neue Methode zur Darstellung langkettiger Carbonsäuren, X. Mitteil.: Darstellung β‐dimethyl‐verzweigter Carbonsäuren
Authors: Stetter Hermann , Kesseler Helmut , Meisel Hans
Published: May 2007

Das ursprünglich für Dihydroresorcin ausgearbeitete Verfahren wurde auf Dimedon übertragen. Durch Kondensation von Dimedon mit Benzylchlorid und Bromessigester wurden die entsprechenden C‐alkylierten Dimedone erhalten, die bei der reduktiven Säurespaltung 2.2‐Dimethyl‐6‐phenyl‐hexan‐carbonsäure‐(1) und β,β‐Dimethyl‐korksäure ergaben. Durch reduktive Säurespaltung von Methylen‐bis‐dimedon wurde ferner β,β,β′,β′‐Tetramethyl‐brassylsäure erhalten. β,β‐Dimethyl‐azelainsäure bildete sich durch reduktive Säurespaltung des Michael‐Adduktes von Dimedon an Acrylsäureester.
Versuche mit Coniferylalkohol
Authors: Freudenberg Karl , Achtzehn Güunther
Published: May 2007

Der Coniferylalkohol‐methyläther (I) wurde in kristallisiertem Zustande gewonnen. Bei seiner Polymerisation oder Polykondensation durch Säuren tritt ein starker Verlust an Methoxyl ein. Das UV‐Absorptionsspektrum des durch Redoxase hergestellten Dehydrierungspolymerisats des Äthers stimmt mit dem des Lignins überein. Über den Benzyläther‐coniferylalkohol (IV) läβsZt sich mit Jod und Silberbenzoat nach Ch. Prévost das Guajacyl‐glycerin (VII) gewinnen.

Die Reaktionsgeschwindigkeit von o‐Nitro‐phthalsäure‐anhydrid mit Alkoholen und Phenolen wurde untersucht. Im Gegensatz zu einer Angabe in der Literatur ist der Unterschied der Geschwindigkeiten für eine analytische Unterscheidung von primären Alkoholen und anderen Oxyverbindungen nicht ausreichend.
Über Nitrosoverbindungen, III. Mitteil.: Bildung prim. und sek. Bis‐nitroso‐Verbindungen durch Radikalreaktionen und ihre Umwandlung in Oxime
Authors: Müller Eugen , Metzger Horst
Published: May 2007

Bei der Einwirkung eines Gemisches von Stickstoffmonoxyd und Chlor unter gleichzeitiger Belichtung mit UV‐Licht auf Cyclohexan, Toluol oder n‐Heptan entstehen farblose sek. bzw. prim. Bis‐nitroso‐Verbindungen, die im Falle des Cyclohexans und Toluols in Substanz isoliert und deren Konstitution durch eine auf anderem Wege verlaufende eindeutige Synthese bewiesen werden konnte. Auf die Bildung eines Gemisches isomerer Bis‐[x‐nitroso‐n‐heptane] unter den Reaktionsbedingungen läßt sich indirekt schließen und dieser Schluß durch gesonderte Synthese des Bis‐[4‐nitroso‐n‐heptans] ebenfalls erhärten. Alle Bis‐nitroso‐Verbindungen kann man durch kurzes Erwärmen, sei es in Substanz oder in einem geeigneten Lösungsmittel, mit sehr guten Ausbeuten in die entsprechenden Oxime umlagern.