Kooperativer Bibliotheksverbund

Berlin Brandenburg

and
and

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
Filter
Language
Year
  • 1
    Language: English
    In: Analytical and bioanalytical chemistry, August 2011, Vol.401(2), pp.657-66
    Description: Nowadays, the most common strategies used in quantitative proteomics are based on isotope-coded labeling followed by specific molecule mass spectrometry. The implementation of inductively coupled plasma mass spectrometry (ICP-MS) for quantitative purposes can solve important drawbacks such as lack of sensitivity, structure-dependent responses, or difficulties in absolute quantification. Recently, lanthanide-containing labels as metal-coded affinity tag (MeCAT) reagents have been introduced, increasing the interest and scope of elemental mass spectrometry techniques for quantitative proteomics. In this work one of the first methodologies for absolute quantification of peptides and proteins using MeCAT labeling is presented. Liquid chromatography (LC) interfaced to ICP-MS has been used to separate and quantify labeled peptides while LC coupled to electrospray ionization mass spectrometry served for identification tasks. Synthetic-labeled peptides were used as standards to calibrate the response of the detector with compounds as close as possible to the target species. External calibration was employed as a quantification technique. The first step to apply this approach was MeCAT-Eu labeling and quantification by isotope dilution ICP-MS of the selected peptides. The standards were mixed in different concentrations and subjected to reverse-phase chromatography before ICP-MS detection to consider the column effect over the peptides. Thus, the prepared multi-peptide mix allowed a calibration curve to be obtained in a single chromatographic run, correcting possible non-quantitative elutions of the peptides from the column. The quantification strategy was successfully applied to other labeled peptides and to standard proteins such as digested lysozyme and bovine serum albumin.
    Keywords: Metals -- Chemistry ; Muramidase -- Analysis ; Peptides -- Analysis ; Serum Albumin, Bovine -- Analysis ; Staining and Labeling -- Methods
    ISSN: 16182642
    E-ISSN: 1618-2650
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Language: English
    In: The Science of the Total Environment, Nov 15, 2015, Vol.533, p.40(9)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.scitotenv.2015.06.090 Byline: Diego Fernandez, Katharina Voss, Mirco Bundschuh, Jochen P. Zubrod, Ralf B. Schafer Abstract: Large amounts of fungicides are applied globally and partly enter freshwater ecosystems. A few laboratory studies examined their effects on decomposer communities and the ecosystem process of litter decomposition (LD), whereas the field situation remains largely unknown. We conducted a field study with 17 stream sites in a German vineyard area where fungicides represent the dominant pest control agent. Passive samplers were used to monitor 15 fungicides and 4 insecticides in streams and their toxicity was described using the toxic unit approach, whereas sediment samples were taken to characterise total copper concentrations. Microbial and leaf-shredding invertebrate community composition and related LD rates were assessed at each site. The structure of microbial and shredder communities as well as fungal biomass changed along the fungicide toxicity gradient. The changes in microbial endpoints were associated with a reduction of microbial LD rate of up to 40% in polluted streams. By contrast, neither the invertebrate LD rate nor in-situ measured gammarid feeding rates correlated with fungicide toxicity, but both were negatively associated with sediment copper concentrations. A subsequent laboratory experiment employing field fungicide concentrations suggested that the microbial community changes are causal. Overall, our results suggest that fungicides can affect LD under field conditions. Article History: Received 20 April 2015; Revised 22 June 2015; Accepted 22 June 2015 Article Note: (miscellaneous) Editor: D. Barcelo
    Keywords: Fungicides – Analysis ; Vineyards – Analysis ; Wineries – Analysis ; Freshwater Ecosystems – Analysis ; Sediments (Geology) – Analysis
    ISSN: 0048-9697
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 3
    Language: English
    In: Environmental Pollution, Nov, 2014, Vol.194, p.196(7)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.envpol.2014.08.001 Byline: Diego Fernandez, Etienne L.M. Vermeirssen, Nicole Bandow, Katherine Munoz, Ralf B. Schafer Abstract: Rainfall-triggered runoff is a major driver of pesticide input in streams. Only few studies have examined the suitability of passive sampling to quantify such episodic exposures. In this study, we used Emporeacents styrene-divinylbenzene reverse phase sulfonated disks (SDB disks) and event-driven water samples (EDS) to assess exposure to 15 fungicides and 4 insecticides in 17 streams in a German vineyard area during 4 rainfall events. We also conducted a microcosm experiment to determine the SDB-disk sampling rates and provide a free-software solution to derive sampling rates under time-variable exposure. Sampling rates ranged from 0.26 to 0.77 L d.sup.-1 and time-weighted average (TWA) concentrations from 0.05 to 2.11 [mu]g/L. The 2 sampling systems were in good agreement and EDS exceeded TWA concentrations on average by a factor of 3. Our study demonstrates that passive sampling is suitable to quantify episodic exposures from polar organic pesticides. Author Affiliation: (a) Institute for Environmental Sciences, University Koblenz-Landau, Fortstrasse 7, 76829 Landau in der Pfalz, Germany (b) Swiss Centre for Applied Ecotoxicology Eawag-EPFL, Uberlandstrasse 133, 8600 Dubendorf, Switzerland (c) Federal Institute for Materials Research and Testing, Unter den Eichen 87, 12205 Berlin, Germany Article History: Received 23 June 2014; Revised 29 July 2014; Accepted 1 August 2014
    Keywords: Fungicides ; Rain ; Insecticides
    ISSN: 0269-7491
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 4
    Language: English
    In: Analytical chemistry, 03 February 2015, Vol.87(3), pp.1613-21
    Description: Molecular mass spectrometry has been applied to simultaneously obtain molecular and elemental information from metal-containing species. Energy tuning of the higher-energy collision dissociation (HCD) fragmentation cell allows the controlled production of typical peptide fragments or elemental reporter ions informing about the metallic content of the analyzed species. Different instrumental configurations and fragmentation techniques have been tested, and the efficiency extracting the elemental information has been compared. HCD fragmentation operating at very high energy led to the best results. Platinum, lanthanides, and iodine reporter ions from peptides interacting with cisplatin, peptides labeled with lanthanides-MeCAT-IA, and iodinated peptides, respectively, were obtained. The possibility to produce abundant molecular and elemental ions in the same analysis simplifies the correlation between both signals and open pathways in metallomics studies enabling the specific tracking of metal-containing species. The proposed approach has been successfully applied to in solution standards and complex samples. Moreover, interesting preliminary MALDI-imaging experiments have been performed showing similar metal distribution compared to laser ablation (LA)-ICPMS.
    Keywords: Engineering ; Chemistry;
    ISSN: 00032700
    E-ISSN: 1520-6882
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 5
    Language: English
    In: Proceedings of the National Academy of Sciences of the United States of America, 24 May 2016, Vol.113(21), pp.6047-52
    Description: The suprachiasmatic nucleus (SCN) receives direct retinal input from the intrinsically photosensitive retinal ganglion cells (ipRGCs) for circadian photoentrainment. Interestingly, the SCN is the only brain region that receives equal inputs from the left and right eyes. Despite morphological assessments showing that axonal fibers originating from ipRGCs cover the entire SCN, physiological evidence suggests that only vasoactive intestinal polypeptide (VIP)/gastrin-releasing peptide (GRP) cells located ventrally in the SCN receive retinal input. It is still unclear, therefore, which subpopulation of SCN neurons receives synaptic input from the retina and how the SCN receives equal inputs from both eyes. Here, using single ipRGC axonal tracing and a confocal microscopic analysis in mice, we show that ipRGCs have elaborate innervation patterns throughout the entire SCN. Unlike conventional retinal ganglion cells (RGCs) that innervate visual targets either ipsilaterally or contralaterally, a single ipRGC can bilaterally innervate the SCN. ipRGCs form synaptic contacts with major peptidergic cells of the SCN, including VIP, GRP, and arginine vasopressin (AVP) neurons, with each ipRGC innervating specific subdomains of the SCN. Furthermore, a single SCN-projecting ipRGC can send collateral inputs to many other brain regions. However, the size and complexity of the axonal arborizations in non-SCN regions are less elaborate than those in the SCN. Our results provide a better understanding of how retinal neurons connect to the central circadian pacemaker to synchronize endogenous circadian clocks with the solar day.
    Keywords: Circadian ; Iprgcs ; Melanopsin ; Non-Image–Forming Functions ; Suprachiasmatic Nucleus ; Circadian Clocks -- Physiology ; Retinal Ganglion Cells -- Metabolism ; Suprachiasmatic Nucleus -- Metabolism ; Synapses -- Metabolism ; Vision, Ocular -- Physiology
    ISSN: 00278424
    E-ISSN: 1091-6490
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 6
    Language: English
    In: The Science of the Total Environment, August 15, 2012, Vol.432, p.65(13)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.scitotenv.2012.05.077 Byline: Gregory T. Carling, Diego P. Fernandez, William P. Johnson Keywords: Aeolian dust; Trace elements; Mercury; Snow chemistry; Dust chemistry; Wasatch Mountains Abstract: Depth-integrated snow columns were collected at 12 sites across the central Wasatch Mountains, Utah, during March and April 2010 to determine concentrations of trace elements, major anions and cations, and pH. Sample collection was conducted at or near maximum snow accumulation prior to the onset of melt, and included spring dust events driven by southerly pre-frontal winds. Snow samples were melted in the laboratory and subsampled for analyses on filtered (0.45[mu]m) and unfiltered fractions. All measured elements (Al, As, Ba, Ca, Co, Cr, Cu, Fe, Hg, K, Li, Mg, Mn, Na, Ni, Pb, Sb, Sr, Ti, Tl, U, V, and Zn) and major anions (Cl, NO.sub.3, and SO.sub.4) displayed significant increases in concentration (for example, factor of 2 to 5 increases for As, Cr, Hg, and Pb) between the six sites sampled in March (prior to dust events) and the six sites sampled in April (after dust events). Acid neutralizing capacity and pH were also elevated in April relative to March snowpack. Comparison of elemental concentration in the particulate (〉0.45[mu]m; difference between unfiltered and filtered concentration) and soluble (〈0.45[mu]m; filtered concentration) fractions shows that the concentration increase between March and April snowpack for the trace elements is primarily a result of association with dust particles 〉0.45[mu]m. The results suggest that the majority of trace element loading to the Wasatch snowpack occurs via dust deposition. The major elements were primarily loaded in the 〈0.45[mu]m fraction, suggesting deposition of soluble dust particles. The overall findings of this paper are similar to other studies regarding the role of dust on nutrient and trace element accumulation in soils and lake sediments, but to our knowledge this is the first study that compares trace element chemistry of seasonal snowpack before and after dust deposition events. Article History: Received 26 October 2011; Revised 7 May 2012; Accepted 14 May 2012
    ISSN: 0048-9697
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 7
    Language: English
    In: Environmental Pollution, November 2014, Vol.194, pp.196-202
    Description: Rainfall-triggered runoff is a major driver of pesticide input in streams. Only few studies have examined the suitability of passive sampling to quantify such episodic exposures. In this study, we used Empore™ styrene-divinylbenzene reverse phase sulfonated disks (SDB disks) and event-driven water samples (EDS) to assess exposure to 15 fungicides and 4 insecticides in 17 streams in a German vineyard area during 4 rainfall events. We also conducted a microcosm experiment to determine the SDB-disk sampling rates and provide a free-software solution to derive sampling rates under time-variable exposure. Sampling rates ranged from 0.26 to 0.77 L d and time-weighted average (TWA) concentrations from 0.05 to 2.11 μg/L. The 2 sampling systems were in good agreement and EDS exceeded TWA concentrations on average by a factor of 3. Our study demonstrates that passive sampling is suitable to quantify episodic exposures from polar organic pesticides. Episodic exposure to 19 pesticides was determined in vineyard streams using passive sampling in concert with a calibration experiment and a novel algorithm to derive sampling rates.
    Keywords: Passive Sampling ; Pesticide ; Water Monitoring ; Freshwater ; Engineering ; Environmental Sciences ; Anatomy & Physiology
    ISSN: 0269-7491
    E-ISSN: 1873-6424
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 8
    Language: English
    In: Journal of Experimental Psychology: General, 2012, Vol.141(3), pp.527-538
    Description: The time spent making a decision and its quality define a widely studied trade-off. Some models suggest that the time spent is set to optimize reward, as verified empirically in simple-decision making experiments. However, in a more complex perspective compromising components of regulation focus, ambitions, fear, risk and social variables, adjustment of the speed–accuracy trade-off may not be optimal. Specifically, regulatory focus theory shows that people can be set in a promotion mode, where focus is on seeking to approach a desired state (to win), or in a prevention mode, focusing to avoid undesired states (not to lose). In promotion, people are eager to take risks increasing speed and decreasing accuracy. In prevention, strategic vigilance increases, decreasing speed and improving accuracy. When time and accuracy have to be compromised, one can ask which of these 2 strategies optimizes reward, leading to optimal performance. This is investigated here in a unique experimental environment. Decision making is studied in rapid-chess (180 s per game), in which the goal of a player is to mate the opponent in a finite amount of time or, alternatively, time-out of the opponent with sufficient material to mate. In different games, players face strong and weak opponents. It was observed that (a) players adopt a more conservative strategy when facing strong opponents, with slower and more accurate moves, and (b) this strategy is suboptimal: Players increase their winning likelihood against strong opponents using the policy they adopt when confronting opponents with similar strength.
    Keywords: Chess ; Decision Making ; Response Time ; Adaptation ; Speed–Accuracy Trade-Off
    ISSN: 0096-3445
    E-ISSN: 1939-2222
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 9
    Language: English
    In: Computers & Education, Oct, 2013, Vol.68, p.307(7)
    Description: To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.compedu.2013.05.018 Byline: Matias Lopez-Rosenfeld, Andrea Paula Goldin, Sebastian Lipina, Mariano Sigman, Diego Fernandez Slezak Abstract: There is big consensus that computer games may be an effective way of learning and many initiatives are being developed where aspects from cognitive sciences are being applied in the development of these games. In this article, we present Mate Marote, a flexible framework for large-scale educational interventions. Based on the delivery programs of computers to each student in Argentinian schools, we developed an environment that provides activities/games and registers usage statistics. This framework keeps installation up-to-date connecting with a central server as Internet connection is detected, synchronizing new activities, version updates and usage history. As a first testbed intervention, we deployed three games in La Rioja province (Argentina), where OLPC is the official program. These games were focused on training inhibitory control, working memory and planning skills. We found that usage statistics of games replicate previous results found at the laboratory, showing that this platform works as an intervention framework despite its unsupervised nature. Author Affiliation: (a) Laboratorio de Inteligencia Artificial Aplicada, Departamento de Computacion, FCEyN, UBA, Argentina (b) Laboratorio de Neurociencia Integrativa, Departamento de Fisica, FCEyN UBA and IFIBA, CONICET, Pabellon 1, Ciudad Universitaria, Buenos Aires C1428EGA, Argentina (c) Universidad Torcuato Di Tella, Alte. Juan Saenz Valiente 1010, Buenos Aires C1428BIJ, Argentina (d) Unidad de Neurobiologia Aplicada, UNA-CEMIC-CONICET, Argentina (e) Universidad Nacional de San Martin, Argentina Article History: Received 20 February 2013; Revised 13 May 2013; Accepted 17 May 2013
    Keywords: Computer Games -- Usage ; Response To Intervention (Education) -- Methods ; Teaching Methods
    ISSN: 0360-1315
    Source: Cengage Learning, Inc.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 10
    Language: English
    In: Analytical and Bioanalytical Chemistry, 2011, Vol.401(2), pp.657-666
    Description: Nowadays, the most common strategies used in quantitative proteomics are based on isotope-coded labeling followed by specific molecule mass spectrometry. The implementation of inductively coupled plasma mass spectrometry (ICP-MS) for quantitative purposes can solve important drawbacks such as lack of sensitivity, structure-dependent responses, or difficulties in absolute quantification. Recently, lanthanide-containing labels as metal-coded affinity tag (MeCAT) reagents have been introduced, increasing the interest and scope of elemental mass spectrometry techniques for quantitative proteomics. In this work one of the first methodologies for absolute quantification of peptides and proteins using MeCAT labeling is presented. Liquid chromatography (LC) interfaced to ICP-MS has been used to separate and quantify labeled peptides while LC coupled to electrospray ionization mass spectrometry served for identification tasks. Synthetic-labeled peptides were used as standards to calibrate the response of the detector with compounds as close as possible to the target species. External calibration was employed as a quantification technique. The first step to apply this approach was MeCAT-Eu labeling and quantification by isotope dilution ICP-MS of the selected peptides. The standards were mixed in different concentrations and subjected to reverse-phase chromatography before ICP-MS detection to consider the column effect over the peptides. Thus, the prepared multi-peptide mix allowed a calibration curve to be obtained in a single chromatographic run, correcting possible non-quantitative elutions of the peptides from the column. The quantification strategy was successfully applied to other labeled peptides and to standard proteins such as digested lysozyme and bovine serum albumin. Figure MeCAT_Eu labeling after tryptic digestion for absolute protein quantification by LC-ICP-MS
    Keywords: Quantitative proteomics ; ICP-MS ; MeCAT ; Lanthanide labeling ; Absolute quantification
    ISSN: 1618-2642
    E-ISSN: 1618-2650
    Source: Springer Science & Business Media B.V.
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. Further information can be found on the KOBV privacy pages