Home About us Contact
|
Home About us Contact | ||
|
|
||
DP
Kinds of DP Selected AbstractsRegulation of oocyte maturation in fishDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 2008Yoshitaka Nagahama A period of oocyte growth is followed by a process called oocyte maturation (the resumption of meiosis) which occurs prior to ovulation and is a prerequisite for successful fertilization. Our studies using fish models have revealed that oocyte maturation is a three-step induction process involving gonadotropin (LH), maturation-inducing hormone (MIH), and maturation-promoting factor (MPF). LH acts on the ovarian follicle layer to produce MIH (17,, 20,-dihydroxy-4-pregnen-3-one, 17,, 20,-DP, in most fishes). The interaction of ovarian thecal and granulosa cell layers (two-cell type model), is required for the synthesis of 17,,20,-DP. The dramatic increase in the capacity of postvitellogenic follicles to produce 17,,20,-DP in response to LH is correlated with decreases in P450c17 (P450c17-I) and P450 aromatase (oP450arom) mRNA and increases in the novel form of P450c17 (P450c17-II) and 20,-hydroxysteroid dehydrogenase (20,-HSD) mRNA. Transcription factors such as Ad4BP/SF-1, Foxl2, and CREB may be involved in the regulation of expression of these steroidogenic enzymes. A distinct family of G-protein-coupled membrane-bound MIH receptors has been shown to mediate non-genomic actions of 17,, 20,-DP. The MIH signal induces the de novo synthesis of cyclin B from the stored mRNA, which activates a preexisting 35 kDa cdc2 kinase via phosphorylation of its threonine 161 by cyclin-dependent kinase activating kinase, thus producing the 34 kDa active cdc2 (active MPF). Upon egg activation, MPF is inactivated by degradation of cyclin B. This process is initiated by the 26S proteasome through the first cut in its NH2 terminus at lysine 57. [source] Embryonic dermal condensation and adult dermal papilla induce hair follicles in adult glabrous epidermis through different mechanismsDEVELOPMENT GROWTH & DIFFERENTIATION, Issue 2 2006Mutsumi Inamatsu Hair induction in the adult glabrous epidermis by the embryonic dermis was compared with that by the adult dermis. Recombinant skin, composed of the adult sole epidermis and the embryonic dermis containing dermal condensations (DC), was transplanted onto the back of nude mice. The epidermis of transplants formed hairs. Histology on the induction process demonstrated the formation of placode-like tissues, indicating that the transplant produces hair follicles through a mechanism similar to that underlying hair follicle development in the embryonic skin. An isolated adult rat sole skin piece, inserted with either an aggregate of cultured dermal papilla (DP) cells or an intact DP between its epidermis and dermis, was similarly transplanted. The transplant produced hair follicles. Histology showed that the epidermis in both cases surrounded the aggregates of DP cells. The epidermis never formed placode-like tissues. Thus, it was concluded that the adult epidermal cells recapitulate the embryonic process of hair follicle development when exposed to DC, whereas they get directly into the anagen of the hair cycle when exposed to DP. The expression pattern of Edar and Shh genes, and P-cadherin protein during the hair follicle development in the two types of transplants supported the above conclusion. [source] Signaling in the third dimension: The peripodial epithelium in eye disc developmentDEVELOPMENTAL DYNAMICS, Issue 9 2009Mardelle Atkins Abstract The eye-antennal imaginal disc of Drosophila melanogaster has often been described as an epithelial monolayer with complex signaling events playing out in two dimensions. However, the imaginal disc actually comprises two opposing epithelia (the peripodial epithelium, or PE, and the disc proper, or DP) separated by a lumen to form a sac-like structure. Recent studies expose complex molecular interactions between the PE and the DP, and reveal dynamic communication between the two tissues. Further findings suggest the PE makes important contributions to DP development by acting as a source of signaling molecules as well as cells. Here we summarize those findings and highlight implications for further research. Developmental Dynamics 238:2139,2148, 2009. © 2009 Wiley-Liss, Inc. [source] A computer program (WDTSRP) designed for computation of sand drift potential (DP) and plotting sand rosesEARTH SURFACE PROCESSES AND LANDFORMS, Issue 6 2007W. A. Saqqa Abstract Wind Data Tabulator and Sand Rose Plotter (WDTSRP) is an interactive developed computer program accessible for estimating sand transport potential by winds in barren sandy deserts. The Fryberger (1979) formula for determining sand drift potential (DP) was adopted to create and develop the computer program. WDTSRP is capable of working out weighting factors (WFs), frequency of wind speed occurrence (t), drift potential (DP), resultant drift potential (RDP) and directional variability of winds (DV) and of plotting sand roses. The developed computer program is built up of a simplified system driven by a group of options and dialogue boxes that allow users to input and handle data easily and systematically. Copyright © 2006 John Wiley & Sons, Ltd. [source] Voltammetry as a Virtual Potentiometric Sensor in Modeling of a Metal-Ligand System and Refinement of Stability Constants.ELECTROANALYSIS, Issue 8 2004Part 1. Abstract A mathematical conversion of data coming from nonequilibrium and dynamic voltammetric techniques (a direct current sampled (DC) and differential pulse (DP) polarography) into potentiometric sensor type of data is described and tested on a dynamic metal-ligand system. A combined experiment involving DCP, DPP and glass electrode potentiometry (GEP) was performed on a single solution sample containing a fixed [LT],:,[MT] ratio (acid-base titration). Dedicated potentiometric software ESTA was successfully employed in the refinement operations performed on virtual potentiometric (VP) data obtained from DC and DP polarography. It was possible to refine stability constants either separately, from VP-DC or VP-DP, or simultaneously from any combination of VP-DC, VP-DP and GEP. The concept of VP-DC or VP-DP is reported for the first time and numerous documented and possible advantages are discussed. The proposed procedure can be easily utilized also by nonelectrochemists who are interested in, e.g., the ligand design strategies. [source] Capillary electrophoresis analysis of glucooligosaccharide regioisomersELECTROPHORESIS, Issue 6 2004Gilles Joucla Abstract Complex gluco-oligosaccharide mixtures of two regioisomer series were successfully separated by CE. The gluco-oligosaccharide series were synthesized, employing a dextransucrase from Leuconostoc mesenteroides NRRL B-512F, by successive glucopyranosyl transfers from sucrose to the acceptor glucose or maltose. The glucosyl transfer to both acceptors, occurring through the formation of ,1,6 linkages, differed for the two series only in the glucosidic bond to the reducing end namely ,1,6 or ,1,4 bond for glucose or maltose acceptor, respectively. Thus, the combination of the two series results in mixed pairs of gluco-oligosaccharide regioisomers with different degrees of polymerization (DP). These regioisomer series were first derivatized by reductive amination with 9-aminopyrene-1,4,6-trisulfonate (APTS). Under acidic conditions using triethyl ammonium acetate as electrolyte, the APTS-gluco-oligosaccharides of each series were separated enabling unambiguous size determination by coupling CE to electrospray-mass spectrometry. However, neither these acidic conditions nor alkaline buffer systems could be adapted for the separation of the gluco-oligosaccharide regioisomers arising from the two combined series. By contrast, increased resolution was observed in an alkaline borate buffer, using differential complexation of the regioisomers with the borate anions. Such conditions were also successfully applied to the separation of glucodisaccharide regioisomers composed of ,1,2, ,1,3, ,1,4, and ,1,6 linkages commonly synthesized by glucansucrase enzymes. [source] Contaminant pattern and bioaccumulation of legacy and emerging organhalogen pollutants in the aquatic biota from an e-waste recycling region in South ChinaENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 4 2010Ying Zhang Abstract Legacy pollutants, polychlorinated biphenyls (PCBs), dichlorodiphenyl trichloroethane and its metabolites (DDTs), and some emerging organhalogen pollutants, such as polybrominated diphenyl ethers (PBDEs), hexabromobenzene (HBB), pentabromotoluene (PBT), 2,3,4,5,6-pentabromoethyl benzene (PBEB), 1,2- bis (2,4,6-tribromophenoxy) ethane (BTBPE), and dechlorane plus (DP), were detected in an aquatic food chain (invertebrates and fish) from an e-waste recycling region in South China. Polychlorinated biphenyls, DDTs, PBDEs, and HBB were detected in more than 90% of the samples, with respective concentrations ranging from not detected (ND),32,000,ng/g lipid weight, ND,850,ng/g lipid weight, 8 to 1,300,ng/g lipid weight, and 0.28 to 240,ng/g lipid weight. Pentabromotoluene, PBEB, BTBPE, and DP were also quantifiable in collected samples with a concentration range of ND,40,ng/g lipid weight. The elevated levels of PCBs and PBDEs in the organisms, compared with those in non-e-waste regions in South China, suggest that these two kinds of pollutants derived mainly from e-waste recycling practices. Hexabromobenzene was significantly correlated with PBDEs, implying that HBB come from the release of e-waste along with PBDEs and/or the pyrolysis of BDE209. Most of the compounds whose trophic magnification factor (TMF) could be calculated were found to biomagnify (TMF > 1). Hexabromobenzene was also found, for the first time, to biomagnify in the present food web, with a TMF of 2.1. Environ. Toxicol. Chem. 2010;29:852,859. © 2010 SETAC [source] Dystonic Posturing Associated with Putaminal Hyperperfusion Depicted on Subtraction SPECTEPILEPSIA, Issue 8 2004Masahiro Mizobuchi Summary:,Purpose: Dystonic posturing (DP) is one of the most reliable lateralizing indicators for temporal lobe epilepsy (TLE). We evaluated the ictal hyperperfusional areas in patients with DP by using ictal,interictal subtraction single-photon emission computed tomography (SPECT). Methods: Ninety-seven patients were treated surgically for intractable TLE, and 39 patients underwent ictal and interictal SPECT studies with the same isotope. These patients were divided into three groups: group I with DP of the contralateral side extended to the epileptogenic focus, group II with elevated muscle tonus but without DP, and group III without DP or alteration of muscle tonus. Ictal, interictal SPECT and thin-slice magnetic resonance imaging (MRI) were overlaid by using the automatic multimodality registration program to construct ictal,interictal subtracted images of SPECT on MRI. Results: Thirteen patients belonged to group I; 14, to group II; and 12, to group III. A statistically significant difference in hyperperfusion rate was observed in the putamen (10 patients in group I, three in group II and two in group III; p < 0.01) and mesial temporal lobe (10 patients in group I, seven in group II, and two in group III; p < 0.05) on the ipsilateral side of the epileptogenic focus. No statistically significant difference was observed for other ictal symptoms except ipsilateral upper-limb automatism (eight patients in group I, three in group II, and none in group III; p < 0.01). Conclusions: A strong correlation between DP and hyperperfusion in the putamen and mesial temporal lobe was demonstrated. Some patients showed a wide hyperperfusion area extending from the mesial temporal lobe to putamen, which may correspond to the propagation of epileptic discharges. Our results suggest a correlation between hyperperfusion of putamen and contralateral dystonic posturing. [source] Angelman Syndrome: Difficulties in EEG Pattern Recognition and Possible MisinterpretationsEPILEPSIA, Issue 8 2003Kette D. Valente Summary: Purpose: This study aimed to evaluate the sensitivity of the EEG in Angelman syndrome (AS), to verify the age at onset of suggestive EEGs and to study EEG patterns, analyzing variations and comparing our findings with nomenclature previously used. Methods: Seventy EEG and 15 V-EEGs of 26 patients were analyzed. Suggestive EEG patterns of AS were classified in delta pattern (DP), theta pattern (TP), and posterior discharges (PDs). Generic terms were used to simplify the analysis. Results: Suggestive EEGs were observed in 25 (96.2%) patients. DP occurred in 22 patients with four variants,hypsarrhythmic-like: irregular, high-amplitude, generalized delta activity (DA) with multifocal epileptiform discharges (EDs); slow variant: regular, high-amplitude, generalized DA with rare EDs; ill-defined slow spike-and-wave: regular, high-amplitude, generalized DA with superimposed EDs characterizing a slow wave, with notched appearance; triphasic-like: rhythmic, moderate-amplitude DA over anterior regions with superimposed EDs. TP was observed in eight patients, as generalized or over the posterior regions. PDs were seen in 19 patients as runs of sharp waves or runs of high-amplitude slow waves with superimposed EDs. TP was the only age-related pattern (younger than 8 years) and observed only in patients with deletion. In 15 patients who had an EEG before the clinical diagnosis, 60% had a suggestive tracing. Conclusions: Although some EEG descriptions are not very detailed, and every author describes findings in a slightly different manner, obviously a common denominator must exist. In this context, EEG seems to be a very sensitive method for the diagnosis of AS, offering an opportunity to corroborate this etiologic diagnosis. Conversely, we do not believe that these patterns may be accounted as specific, except for the delta pattern, which seems to be extremely unusual in other syndromes. Other EEG patterns observed in AS, such as theta activity and PDs, occur in a wide variety of disorders. Nonetheless, their importance for the EEG diagnosis of AS is supported by the fact that they are associated with other features and may be helpful in a proper clinical setting. [source] Intestinal double-positive CD4+CD8+ T,cells are highly activated memory cells with an increased capacity to produce cytokinesEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2006Bapi Pahar Dr. Abstract Peripheral blood and intestinal CD4+CD8+ double-positive (DP) T,cells have been described in several species including humans, but their function and immunophenotypic characteristics are still not clearly understood. Here we demonstrate that DP T,cells are abundant in the intestinal lamina propria of normal rhesus macaques (Macaca mulatta). Moreover, DP T,cells have a memory phenotype and are capable of producing different and/or higher levels of cytokines and chemokines in response to mitogen stimulation compared to CD4+ single-positive T,cells. Intestinal DP T,cells are also highly activated and have higher expression of CCR5, which makes them preferred targets for simian immunodeficiency virus/HIV infection. Increased levels of CD69, CD25 and HLA-DR, and lower CD62L expression were found on intestinal DP T,cells populations compared to CD4+ single-positive T,cells. Collectively, these findings demonstrate that intestinal and peripheral blood DP T,cells are effector cells and may be important in regulating immune responses, which distinguishes them from the immature DP cells found in the thymus. Finally, these intestinal DP T,cells may be important target cells for HIV infection and replication due to their activation, memory phenotype and high expression of CCR5. [source] MHC class II-independent CD25+ CD4+ CD8,,,+ ,,, T cells attenuate CD4+ T cell-induced transfer colitisEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 3 2004Tamara Krajina Abstract CD4+ ,,, T cell populations that develop in mice deficient in MHC class II (through ,knockout' of either the A,, or the A, chain of the I-Ab molecule) comprise a major ,single-positive' (SP) CD4+ CD8, subset (60,90%) and a minor ,double-positive' (DP) CD4+ CD8,,,+ subset (10,40%). Many DP T cells found in spleen, mesenteric lymph nodes (MLN) and colonic lamina propria (cLP) express CD25, CD103 and Foxp3. Adoptive transfer of SP but not DP T cells from A,,/, or A,,/, B6 mice into congenic RAG,/, hosts induces colitis. Transfer of SP T cells repopulates the host with only SP T cells; transfer of DP T cells repopulates the host with DP and SP T cells. Anti-CD25 antibody treatment of mice transplanted with DP T cells induces severe, lethal colitis; anti-CD25 antibody treatment of mice transplanted with SP T cells further aggravates the course of severe colitis. Hence, regulatory CD25+ T cells within (or developing from) the DP T cell population of MHC class II-deficient mice control the colitogenic potential of CD25, CD4+ T cells. [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] Polymers from renewable resources: Bulk ATRP of fatty alcohol-derived methacrylatesEUROPEAN JOURNAL OF LIPID SCIENCE AND TECHNOLOGY, Issue 9 2008Gökhan Çayli Abstract Copper-mediated atom transfer radical polymerization (ATRP) of lauryl methacrylate (LMA) and other long-chain methacrylates was investigated in bulk at 35,°C by using CuCl/N,N,N,,N,,N,, -pentamethyldiethylenetriamine (PMDETA)/tricaprylylmethylammonium chloride (Aliquat®336) as the catalyst system and ethyl 2-bromoisobutyrate (EBIB) as the initiator. The investigated monomers can be derived from fatty alcohols and are therefore an important renewable resource for a sustainable development of our future. The amounts of ligand, Aliquat®336 and CuCl were optimized and the effect of their concentrations on the control of the polymerization and the observed conversions were investigated. It was found that a molar ratio of EBIB/CuCl/Ligand/Aliquat®336 of 1,:,1,:,3,:,1 provided the highest conversions of LMA and the best controlled polymerizations. These optimized conditions allowed for the synthesis of poly(lauryl methcarylate)s with different targeted DP (25, 50, 75, 100, 120, 240, and 500), including high-molecular-weight polymers with narrow molecular weight distributions. In addition, methacrylate monomers were prepared from fatty alcohols (capric, myristic, palmitic, stearic) and polymerized using the developed procedure to obtain polymers with the same DP and different chain lengths (C10, C12, C14, C16, and C18) of pending alkyl groups. Finally, the thermal properties of these polymers were examined by differential scanning calorimetry and thermogravimetric analysis. [source] Effect of auditory cortex lesions on the discrimination of frequency-modulated tones in ratsEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 6 2006Natalia Rybalko Abstract The lateralization of functions to individual hemispheres of the mammalian brain remains, with the exception of the human brain, unresolved. The aim of this work was to investigate the ability to discriminate between falling and rising frequency-modulated (FM) stimuli in rats with unilateral or bilateral lesions of the auditory cortex (AC). Using an avoidance conditioning procedure, thirsty rats were trained to drink in the presence of a rising FM tone and to stop drinking when a falling FM tone was presented. Rats with a lesion of the AC were able to learn to discriminate between rising and falling FM tones; however, they performed significantly worse than did control rats. A greater deficit in the ability to discriminate the direction of frequency modulation was observed in rats with a right or bilateral AC lesion. The discrimination performance (DP) in these rats was significantly worse than the DP in rats with a left AC lesion. Animals with a right or bilateral AC lesion improved their DP mainly by recognizing the pitch at the beginning of the stimuli. The lesioning of the AC in trained animals caused a significant decrease in DP, down to chance levels. Retraining resulted in a significant increase in DP in rats with a left AC lesion; animals with a right lesion improved only slightly. The results demonstrate a hemispheric asymmetry of the rat AC in the recognition of FM stimuli and indicate the dominance of the right AC in the discrimination of the direction of frequency modulation. [source] Reorganization of hair follicles in human skin organ culture induced by cultured human follicle-derived cellsEXPERIMENTAL DERMATOLOGY, Issue 8 2005Walter Krugluger Abstract:, Studies of human hair follicle (HF) induction by follicle-derived cells have been limited due to a lack of suitable test systems. In this study, we established a skin organ culture system which supports HF formation by follicle-derived cells. Long-term skin organ cultures were set up from human retroauricular skin specimens and maintained in culture for up to 8 weeks. In vitro expanded human HF-derived cells from the dermal papilla (DP) and the outer root sheath (ORS) were injected together into the skin specimens and evaluated for their ability to induce reorganization of HFs. Macroscopic analysis of the cultured skin specimens demonstrated the growth of velus-like hair after 4 weeks in culture. Histologic evaluation of the cultured skin specimens after 8 weeks of culture revealed multiple miniaturized HFs with sebaceous glands. In addition, cell clusters of various differentiation stages could be demonstrated in serial sections of the cultured skin specimens. Labeling of HF-derived cells with the fluorescence dye CFDA-1 prior to injection suggested a de novo reorganization of HFs out of the injected cells. In conclusion, the study demonstrated HF formation by HF-derived cells in an in vitro skin organ culture model. [source] Genetics of dermatofibrosarcoma protuberans family of tumors: From ring chromosomes to tyrosine kinase inhibitor treatmentGENES, CHROMOSOMES AND CANCER, Issue 1 2003Nicolas Sirvent Dermatofibrosarcoma protuberans (DP) is a rare, slow-growing, infiltrating dermal neoplasm of intermediate malignancy, made up of spindle-shaped tumor cells often positive for CD34. The preferred treatment is wide surgical excision with pathologically negative margins. At the cytogenetic level, DP cells are characterized by either supernumerary ring chromosomes, which have been shown by using fluorescence in situ hybridization techniques to be derived from chromosome 22 and to contain low-level amplified sequences from 17q22-qter and 22q10,q13.1, or t(17;22), that are most often unbalanced. Both the rings and linear der(22) contain a specific fusion of COL1A1 with PDGFB. Similar to other tumors, the COL1A1-PDGFB fusion is occasionally cryptic, associated with complex chromosomal rearrangements. Although rings have been mainly observed in adults, translocations have been reported in all pediatric cases. DP is therefore a unique example of a tumor in which (i) the same molecular event occurs either on rings or linear translocation derivatives, (ii) the chromosomal abnormalities display an age-related pattern, and (iii) the presence of the specific fusion gene is associated with the gain of chromosomal segments, probably taking advantage of gene dosage effects. In all DP cases that underwent molecular investigations, the breakpoint localization in PDGFB was found to be remarkably constant, placing exon 2 under the control of the COL1A1 promoter. In contrast, the COL1A1 breakpoint was found to be variably located within the exons of the ,-helical coding region (exons 6,49). No preferential COL1A1 breakpoint and no correlation between the breakpoint location and the age of the patient or any clinical or histological particularity have been described. The COL1A1-PDGFB fusion is detectable by multiplex RT-PCR with a combination of forward primers designed from a variety of COL1A1 exons and one reverse primer from PDGFB exon 2. Recent studies have determined the molecular identity of "classical" DP, giant cell fibroblastoma, Bednar tumor, adult superficial fibrosarcoma, and the granular cell variant of DP. In approximately 8% of DP cases, the COL1A1-PDGFB fusion is not found, suggesting that genes other than COL1A1 or PDGFB might be involved in a subset of cases. It has been proposed that PDGFB acts as a mitogen in DP cells by autocrine stimulation of the PDGF receptor. It is encouraging that inhibitory effects of the PDGF receptor tyrosine kinase antagonist imatinib mesylate have been demonstrated in vivo; such targeted therapies might be warranted in the near future for treatment of the few DP cases not manageable by surgery. © 2003 Wiley-Liss, Inc. [source] Modeled interactive effects of precipitation, temperature, and [CO2] on ecosystem carbon and water dynamics in different climatic zonesGLOBAL CHANGE BIOLOGY, Issue 9 2008YIQI LUO Abstract Interactive effects of multiple global change factors on ecosystem processes are complex. It is relatively expensive to explore those interactions in manipulative experiments. We conducted a modeling analysis to identify potentially important interactions and to stimulate hypothesis formulation for experimental research. Four models were used to quantify interactive effects of climate warming (T), altered precipitation amounts [doubled (DP) and halved (HP)] and seasonality (SP, moving precipitation in July and August to January and February to create summer drought), and elevated [CO2] (C) on net primary production (NPP), heterotrophic respiration (Rh), net ecosystem production (NEP), transpiration, and runoff. We examined those responses in seven ecosystems, including forests, grasslands, and heathlands in different climate zones. The modeling analysis showed that none of the three-way interactions among T, C, and altered precipitation was substantial for either carbon or water processes, nor consistent among the seven ecosystems. However, two-way interactive effects on NPP, Rh, and NEP were generally positive (i.e. amplification of one factor's effect by the other factor) between T and C or between T and DP. A negative interaction (i.e. depression of one factor's effect by the other factor) occurred for simulated NPP between T and HP. The interactive effects on runoff were positive between T and HP. Four pairs of two-way interactive effects on plant transpiration were positive and two pairs negative. In addition, wet sites generally had smaller relative changes in NPP, Rh, runoff, and transpiration but larger absolute changes in NEP than dry sites in response to the treatments. The modeling results suggest new hypotheses to be tested in multifactor global change experiments. Likewise, more experimental evidence is needed for the further improvement of ecosystem models in order to adequately simulate complex interactive processes. [source] Application of Direct Push Methods to Investigate Uranium Distribution in an Alluvial AquiferGROUND WATER MONITORING & REMEDIATION, Issue 4 2009Wesley McCall The U.S. EPA 2000 Radionuclide Rule established a maximum contaminant level (MCL) for uranium of 30 µg/L. Many small community water supplies are struggling to comply with this new regulation. At one such community, direct push (DP) methods were applied to obtain hydraulic profiling tool (HPT) logs and install small diameter wells in a section of alluvial deposits located along the Platte River. This work was conducted to evaluate potential sources of elevated uranium in the Clarks, Nebraska drinking water supply. HPT logs were used to understand the hydrostratigraphy of a portion of the aquifer and guide placement of small diameter wells at selected depth intervals. Low-flow sampling of the wells provided water quality parameters and samples for analysis to study the distribution of uranium and variations in aquifer chemistry. Contrary to expectations, the aquifer chemistry revealed that uranium was being mobilized under anoxic and reducing conditions. Review of the test well and new public water supply well construction details revealed that filter packs extended significantly above the screened intervals of the wells. These filter packs were providing a conduit for the movement of groundwater with elevated concentrations of uranium into the supply wells and the community drinking water supply. The methods applied and lessons learned here may be useful for the assessment of unconsolidated aquifers for uranium, arsenic, and many other drinking water supply contaminants. [source] Sequence dependence of cell growth inhibition by EGFR,tyrosine kinase inhibitor ZD1839, docetaxel, and cisplatin in head and neck cancerHEAD & NECK: JOURNAL FOR THE SCIENCES & SPECIALTIES OF THE HEAD AND NECK, Issue 10 2009Carmen M. Klass MD Abstract Background This study was to explore whether the efficacy of the epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor ZD1839 (Z, Iressa, gefitinib) plus chemotherapeutic agents docetaxel (D) and cisplatin (P) may benefit from sequencing of the combination. Methods Three head and neck cancer cell lines were used to study the effect of various combinations of and relative sequencing of D, P, and Z in cell growth inhibition. A population pharmacokinetic stimulation study was conducted on Z in silico and used together with the growth inhibition data to derive principles for future in vivo use of this drug combination. Results The inhibitory effects of Z on combinations of D and P were sequence dependent. Treatment simultaneously with DPZ or with DP followed by Z (DP,Z) showed synergistic effects in all 3 cell lines. However, sequencing with Z followed by DP (Z,DP), gave an antagonistic effect, suggesting that D and P should be administered when the effect of Z is low. The induction of apoptosis was also sequence dependent. The in silico pharmacokinetic study suggested the feasibility of deriving a 5-day-on/2-day-off regimen for Z, in which D and P administration commences when levels of Z are low, allowing levels of Z to accumulate sufficiently during the remainder of the cycle. Conclusion These data suggests that it is feasible to design clinical trials with these settings to maximize the efficacy of this combined drug regimen. © 2009 Wiley Periodicals, Inc. Head Neck, 2009 [source] Comparison of different methodologies for CD4 estimation in a clinical settingHIV MEDICINE, Issue 4 2008S Jeganathan Objective To compare flow cytometry assays, using traditional dual platform (DP) or newer single platform (SP) for CD4 enumeration. Method Records of subjects enrolled in four separate clinical trials using the same central laboratory [SP methodology (Trucount)] were reviewed retrospectively. Eighteen subjects had 60 matching contemporaneous samples at multiple timepoints. Results DP flow cytometry yielded higher CD4 counts in 50/60 assays (83%). CD4 count and percentage by the two methods showed strong correlation for the counts (r=0.965, P<0.0001) and percentages (r=0.959, P<0.0001). Bland,Altman plot analysis showed that the limits of variation were within agreeable limits of ±2SD in 56/60 (93.3%) samples tested. Twenty-five (42%) samples had a difference of >50 cells/,L. Of these six (24%) exceeded 100 cells. Conclusion This study is in agreement with previous reports of strong correlation between DP and SP flow cytometry. This review found differences in CD4 counts in a high proportion of samples tested highlighting the importance for clinicians to be aware of such differences when interpreting results from the two methods. [source] Optimization of Train Speed Profile for Minimum Energy ConsumptionIEEJ TRANSACTIONS ON ELECTRICAL AND ELECTRONIC ENGINEERING, Issue 3 2010Masafumi Miyatake Member Abstract The optimal operation of railway systems minimizing total energy consumption is discussed in this paper. Firstly, some measures of finding energy-saving train speed profiles are outlined. After the characteristics that should be considered in optimizing train operation are clarified, complete optimization based on optimal control theory is reviewed. Their basic formulations are summarized taking into account most of the difficult characteristics peculiar to railway systems. Three methods of solving the formulation, dynamic programming (DP), gradient method, and sequential quadratic programming (SQP), are introduced. The last two methods can also control the state of charge (SOC) of the energy storage devices. By showing some numerical results of simulations, the significance of solving not only optimal speed profiles but also optimal SOC profiles of energy storage are emphasized, because the numerical results are beyond the conventional qualitative studies. Future scope for applying the methods to real-time optimal control is also mentioned. Copyright © 2010 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [source] Dipeptidyl peptidase expression during experimental colitis in miceINFLAMMATORY BOWEL DISEASES, Issue 8 2010Roger Yazbeck PhD Abstract Background: We have previously demonstrated that inhibition of dipeptidyl peptidase (DP) activity partially attenuates dextran sulfate sodium (DSS) colitis in mice. The aim of this study was to further investigate the mechanisms of this protection. Materials and Methods: Wildtype (WT) and DPIV,/, mice consumed 2% DSS in drinking water for 6 days to induce colitis. Mice were treated with saline or the DP inhibitors Ile-Pyrr-(2-CN)*TFA or Ile-Thia. DP mRNA and enzyme levels were measured in the colon. Glucagon-like peptide (GLP)-2 and GLP-1 concentrations were determined by radioimmunoassay, regulatory T-cells (Tregs) by fluorescence activated cell sorting (FACS) on FOXp3+T cells in blood, and neutrophil infiltration assessed by myeloperoxidase (MPO) assay. Results: DP8 and DP2 mRNA levels were increased (P < 0.05) in WT+saline mice compared to untreated WT mice with colitis. Cytoplasmic DP enzyme activity was increased (P < 0.05) in DPIV,/, mice at day 6 of DSS, while DP2 activity was increased (P < 0.05) in WT mice with colitis. GLP-1 (63%) and GLP-2 (50%) concentrations increased in WT+Ile-Pyrr-(2-CN)*TFA mice compared to day-0 controls. MPO activity was lower in WT+Ile-Thia and WT+Ile-Pyrr-(2-CN)*TFA treated mice compared to WT+saline (P < 0.001) at day 6 colitis. Conclusions: DP expression and activity are differentially regulated during DSS colitis, suggesting a pathophysiological role for these enzymes in human inflammatory bowel disease (IBD). DP inhibitors impaired neutrophil recruitment and maintenance of the Treg population during DSS-colitis, providing further preclinical evidence for the potential therapeutic use of these inhibitors in IBD. Finally, DPIV appears to play a critical role in mediating the protective effect of DP inhibitors. Inflamm Bowel Dis 2010 [source] Relationship between sick leave, unemployment, disability, and health-related quality of life in patients with inflammatory bowel diseaseINFLAMMATORY BOWEL DISEASES, Issue 5 2006Tomm Bernklev BSc Background: The goal of this study was to determine the rate of work disability, unemployment, and sick leave in an unselected inflammatory bowel disease (IBD) cohort and to measure the effect of working status and disability on the patient's health-related quality of life (HRQOL). Materials and Methods: All eligible patients were clinically examined and interviewed at the 5-year follow-up visit. In addition, they completed the 2 HRQOL questionnaires, the Short Form-36 Health Survey (SF-36) and the Inflammatory Bowel Disease Questionnaire validated for use in Norway (N-IBDQ). Data regarding sick leave, unemployment, and disability pension (DP) also were collected. Results: All together, 495 patients were or had been in the workforce during the 5-year follow-up period since diagnosis. Forty-two patients (8.5%) were on DP compared with 8.8% in the background population. Women with Crohn's disease (CD) had the highest probability of receiving DP (24.6%). A total of 58 patients (11.7%) reported they were unemployed at 5 years. This was equally distributed between men and women but was more frequent in patients with ulcerative colitis. Sick leave for all causes was reported in 47% with ulcerative colitis and 53% with CD, whereas IBD-related sick leave was reported in 18% and 23%, respectively. A majority (75%) had been sick <4 weeks, and a relatively small number of patients (25%) contributed to a large number of the total sick leave days. Both unemployment and DP reduced HRQOL scores, but the most pronounced effect on HRQOL was found in patients reporting IBD-related sick leave, measured with SF-36 and N-IBDQ. The observed differences also were highly clinically significant. Multiple regression analysis confirmed that IBD-related sick leave was the independent variable with the strongest association to the observed reduction in HRQOL scores. Conclusions: Unemployment or sick leave is more common in IBD patients than in the Norwegian background population. The number of patients receiving DP is significantly increased in women with CD but not in the other patient groups. Unemployment, sick leave, and DP are related to the patient's HRQOL in a negative way, but this effect is most pronounced in patients reporting IBD-related sick leave. [source] Inactivation of root canal medicaments by dentine, hydroxylapatite and bovine serum albuminINTERNATIONAL ENDODONTIC JOURNAL, Issue 3 2001I. Portenier Abstract Aim This study examined and compared the inhibition of the antibacterial effect of saturated calcium hydroxide solution, chlorhexidine acetate and iodine potassium iodide by dentine, hydroxylapatite and bovine serum albumin. MethodologyEnterococcus faecalis strain A197A prepared to a suspension of 3 × 108 cells per ml in 0.5% peptone water was used. Fifty µL of saturated calcium hydroxide solution, 0.05% chlorhexidine acetate or 0.2/0.4% iodine potassium iodide were incubated at 37 °C with 28 mg dentine powder (DP), hydroxylapatite (HA) or bovine serum albumin (BSA) in 50 µL water for 1 h before adding 50 µL of the bacterial suspension. Samples for bacterial culturing were taken from the suspension 1 and 24 h after adding the bacteria. In further experiments, the amount of dentine was stepwise reduced from 28 mg 150 µL,1 to 2.8 mg 150 µL,1. Results Calcium hydroxide was totally inactivated by the presence of 28 mg of DP, HA or BSA. Chlorhexidine (0.05%) was strongly inhibited by BSA and slowed down by dentine. However, HA had little or no inhibitory effect on chlorhexidine. The antibacterial effect of 0.2/0.4% iodine potassium iodide on E. faecalis was totally inhibited by dentine (28 mg), but was practically unaffected by HA or BSA. A stepwise reduction of dentine from 28 mg 150 µL,1 to 2.8 mg 150 µL,1 was followed by a similar reduction of the inhibition of the antibacterial activity of chlorhexidine. Iodine potassium iodide was not inhibited at all with dentine amounts less than 28 mg. However, the effect of saturated calcium hydroxide solution was totally eliminated by dentine, in all four concentrations. Conclusion Inhibition by dentine of the antibacterial activity of calcium hydroxide, chlorhexidine and iodine potassium iodide occurs by different mechanisms. Different components of dentine may be responsible for the inhibition of these three medicaments. Calcium hydroxide was particularly sensitive to inhibition by both inorganic and organic compounds. [source] N -bromosuccinimide oxidation of dipeptides and their amino acids: Synthesis, kinetics and mechanistic studiesINTERNATIONAL JOURNAL OF CHEMICAL KINETICS, Issue 6 2006N. S. Linge Gowda Dipeptides (DP), namely valyl,glycine (Val,Gly), alanyl,proline (Ala,Pro), and valyl,proline (Val,Pro) were synthesized by classical solution phase methods and characterized. The kinetics of oxidation of amino acids (AA) and DP by N -bromosuccinimide (NBS) was studied in the presence of perchlorate ions in acidic medium at 28°C. The reaction was followed spectrophotometrically at ,max = 240 nm. The reactions follow identical kinetics, being first order each in [NBS], [AA], and [DP]. No effect on [H+], reduction product [succinimide], and ionic strength was observed. Effects of varying dielectric constant of the medium and addition of anions such as chloride and perchlorate were studied. Activation parameters have been computed. The oxidation products of the reaction were isolated and characterized. The proposed mechanism is consistent with the experimental results. An apparent correlation was noted between the rate of oxidation of AA and DP. © 2006 Wiley Periodicals, Inc. Int J Chem Kinet 38: 376,385, 2006 [source] Performance analysis of a channel allocation scheme for multi-service mobile cellular networksINTERNATIONAL JOURNAL OF COMMUNICATION SYSTEMS, Issue 2 2007Shensheng Tang Abstract This paper presents a new channel allocation scheme, namely the dynamic partition with pre-emptive priority (DPPP) scheme, for multi-service mobile cellular networks. The system is modelled by a two-dimensional Markov process and analysed by the matrix-analytic method. A pre-emptive priority (PP) mechanism is employed to guarantee the quality of service (QoS) requirement of the real-time (RT) traffic at the expense of some degradation of non-real-time (NRT) traffic, while the victim buffer compensates the degradation and has no negative impact on the RT traffic. The complete service differentiation between new calls and handoff calls from different traffic classes is achieved by using the dynamic partition (DP) concept with the help of related design parameters. The performance analysis and numerical results show that the DPPP scheme, compared with the existing schemes, is effective and practical in multi-service environments. Copyright © 2006 John Wiley & Sons, Ltd. [source] An evaluation of pharmacist-written hospital discharge prescriptions on general surgical wardsINTERNATIONAL JOURNAL OF PHARMACY PRACTICE, Issue 3 2005Mohamed H. Rahman Principal pharmacist, surgical services Objective To evaluate the quality of pharmacist-written hospital discharge prescriptions (DPs) in comparison to those written by doctors. Method The study was carried out in two, week-long phases on the general surgical wards in one UK hospital. In phase 1, doctors wrote the DPs, which were then checked by the ward pharmacist. In phase 2, ward pharmacists wrote the DPs which were then checked by the patient's junior doctor. In both phases, the clinical dispensary pharmacist made their routine check of the prescription prior to dispensing. All interventions were recorded on a pre-piloted data collection form. Key findings In phase 1, doctors wrote 128 DPs; in phase 2, pharmacists wrote 133 DPs. There were 755 interventions recorded during phase 1 in comparison to 76 during phase 2. In phase 1, transcription errors accounted for 118 interventions, 149 were due to ambiguity/illegibility; 488 amendments were to facilitate the dispensing process e.g. clarification of patient, medical and drug details, and dosage form discrepancies. In phase 2, transcription errors accounted for one intervention, 50 interventions were due to ambiguities or illegibility; 25 amendments were to facilitate the dispensing process. During phase 2, doctors made 10 minor alterations to pharmacist-written DPs. On 52 occasions during phase 2, the ward pharmacist had to clarify, prior to writing the DP, either the dose of a drug, or, whether a drug should be continued on discharge, and if so, for what duration. Conclusion Pharmacist-written DPs contained considerably fewer errors, omissions and unclear information in comparison to doctor-written DPs. Doctors recorded no significant alterations when validating pharmacist-written DPs. [source] Linear and non-linear optimization models for allocation of a limited water supply,IRRIGATION AND DRAINAGE, Issue 1 2004Bijan Ghahraman optimisation de l'irrigation; déficit d'irrigation; Iran Abstract One partial solution to the problem of ever-increasing demands on our water resources is optimal allocation of available water. A non-linear programming (NLP) optimization model with an integrated soil water balance was developed. This model is the advanced form of a previously developed one in which soil water balance was not included. The model also has the advantage of low computer run-time, as compared to commonly used dynamic programming (DP) models that suffer from dimensionality. The model can perform over different crop growth stages while taking into account an irrigation time interval in each stage. Therefore, the results are directly applicable to real-world conditions. However, the time trend of actual evapotranspiration (AET) for individual time intervals fluctuates more than that for growth-stage AETs. The proposed model was run for the Ardak area (45,km NW of the city of Mashhad, Iran) under a single cropping cultivation (corn) as well as a multiple cropping pattern (wheat, barley, corn, and sugar beet). The water balance equation was manipulated with net applied irrigation water to overcome the difficulty encountered with incorrect deep percolation. The outputs of the model, under the imposed seasonal irrigation water shortages, were compared with the results obtained from a simple NLP model. The differences between these two models (simple and integrated) became more significant as irrigation water shortage increased. Oversimplified assumptions in the previous simple model were the main causes of these differences. Copyright © 2004 John Wiley & Sons, Ltd. L'allocation optimale des ressources d'eau disponibles est une réponse partielle au problème de la demande sans cesse croissante de consommation d'eau. Un modèle d'optimisation à programmation non linéaire (NLP) qui intègre un bilan hydrique a été développé. Ce modèle est une version avancée d'un modéle précédent qui n'intégrait pas ce bilan hydrique. Il présente l'avantage de nécessiter moins de puissance informatique en comparaison des modèles à programmation dynamique (DP) généralement utilisés. Le modèle peut s'appliquer à différentes étapes de la croissance des cultures et prend en compte des fréquences d'irrigation variables. Ainsi, les résultats sont directement applicables aux conditions réelles. Le modèle proposé a été utilisé sur une seule culture (maïs) dans la région d'Ardak à 45,km nord-ouest de Mashad, Iran, et sur de multiples cultures (blé, orge, maïs, betterave sucrière). L'équation de bilan hydrique a été calibrée pour maîtriser les difficultés rencontrées avec des mesures d'infiltration incorrectes. Les résultats du modèle, dans le cadre de restrictions d'irrigation saisonnière imposées, ont été comparés avec ceux obtenus par un modèle simple NLP. Les différences entre ces deux modèles (simple et intégré) deviennent plus significatives à mesure que les restrictions d'irrigation augmentent. Les hypothèses trop simplistes du modèle simple sont la cause de ces différences. Copyright © 2004 John Wiley & Sons, Ltd. [source] Evolution of blood parameters during weight loss in experimental obese Beagle dogsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 3-4 2004M. Diez Summary The effects of weight loss on hormonal and biochemical blood parameters were measured monthly [carnitine, creatinine, urea, free T4 (fT4), total T4 (TT4), plasma alkaline phosphatases (ALP), aspartate aminotransferase (AST), alanine aminotransferase (ALT), potassium and total proteins] or bimonthly [cholesterol, triglycerides, non-esterified fatty acids (NEFA), insulin-like growth factor I (IGF-I), glucose, insulin] in eight obese Beagles dogs fed either a high protein dry diet, DP (crude protein 47.5%, on dry matter basis) or a commercial high fibre diet, HF (crude protein 23.8%, crude fibre 23.3%). The dogs were allotted to two groups according to sex and body weight (BW) and they were respectively fed with the DP or the control HF diet during 12,26 weeks, until they reach their optimal BW. The plasma basal triglycerides and cholesterol concentrations were decreased by the two diets but the difference was only significant for the DP diet. The plasma mean NEFA concentration increased regularly over the period with the HF diet, without significant difference between the two diets. No effect of diet or weight loss was observed on plasma carnitine, urea, creatinine, ALP, AST, ALT, potassium, TT4, FT4, IGF-I, glucose and insulin. Weight loss induced a decrease in fT4 plasma concentration (p < 0.001). The high protein diet allowed a safe weight loss. [source] Biodegradable poly(vinyl alcohol)- graft - poly(,-caprolactone) comb-like polyester: Microwave synthesis and its characterizationJOURNAL OF APPLIED POLYMER SCIENCE, Issue 6 2007Zhaoju Yu Abstract Poly(vinyl alcohol)-initiated microwave-assisted ring opening polymerization of ,-caprolactone in bulk was investigated, and a series of poly(vinyl alcohol)- graft -poly(,-caprolactone) (PVA- g -PCL) copolymers were prepared, with the degree of polymerization (DP) of PCL side chains and the degree of substitution (DS) of PVA by PCL being in the range of 3,24 and 0.35,0.89, respectively. The resultant comb-like PVA- g -PCL copolymers were confirmed by means of FTIR, 1H NMR, and viscometry measurement. The introduction of hydrophilic backbone resulted in the decrease in both melting point and crystallization property of the PVA- g -PCL copolymers comparing with linear PCL. With higher microwave power, the DP of PCL side chains and DS of PVA backbone were higher, and the polymerization reaction proceeded more rapidly. Both the DP and monomer conversion increased with irradiation time, while the DS increased first and then remained constant. With initiator in low concentration, the DP and DS were higher, while the monomer was converted more slowly. Microwaves dramatically improved the polymerization reaction in comparison of conventional heating method. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 104, 3973,3979, 2007 [source] | |||||||||||||||||||||||||||||||||||||||||||||||||