PEAT-CLSM: A Specific Treatment of Peatland Hydrology in the NASA Catchment Land Surface Model.

Peatlands are poorly represented in global Earth system modeling frameworks. Here we add a peatland-specific land surface hydrology module (PEAT-CLSM) to the Catchment Land Surface Model (CLSM) of the NASA Goddard Earth Observing System (GEOS) framework. The amended TOPMODEL approach of the original CLSM that uses topography characteristics to model catchment processes is discarded, and a peatland-specific model concept is realized in its place. To facilitate its utilization in operational GEOS efforts, PEAT-CLSM uses the basic structure of CLSM and the same global input data. Parameters used in PEAT-CLSM are based on literature data. A suite of CLSM and PEAT-CLSM simulations for peatland areas between 40°N and 75°N is presented and evaluated against a newly compiled data set of groundwater table depth and eddy covariance observations of latent and sensible heat fluxes in natural and seminatural peatlands. CLSM's simulated groundwater tables are too deep and variable, whereas PEAT-CLSM simulates a mean groundwater table depth of -0.20 m (snow-free unfrozen period) with moderate temporal fluctuations (standard deviation of 0.10 m), in significantly better agreement with in situ observations. Relative to an operational CLSM version that simply includes peat as a soil class, the temporal correlation coefficient is increased on average by 0.16 and reaches 0.64 for bogs and 0.66 for fens when driven with global atmospheric forcing data. In PEAT-CLSM, runoff is increased on average by 38% and evapotranspiration is reduced by 19%. The evapotranspiration reduction constitutes a significant improvement relative to eddy covariance measurements.

Atmospheric deposition, CO2, and change in the land carbon sink.

Concentrations of atmospheric carbon dioxide (CO2) have continued to increase whereas atmospheric deposition of sulphur and nitrogen has declined in Europe and the USA during recent decades. Using time series of flux observations from 23 forests distributed throughout Europe and the USA, and generalised mixed models, we found that forest-level net ecosystem production and gross primary production have increased by 1% annually from 1995 to 2011. Statistical models indicated that increasing atmospheric CO2 was the most important factor driving the increasing strength of carbon sinks in these forests. We also found that the reduction of sulphur deposition in Europe and the USA lead to higher recovery in ecosystem respiration than in gross primary production, thus limiting the increase of carbon sequestration. By contrast, trends in climate and nitrogen deposition did not significantly contribute to changing carbon fluxes during the studied period. Our findings support the hypothesis of a general CO2-fertilization effect on vegetation growth and suggest that, so far unknown, sulphur deposition plays a significant role in the carbon balance of forests in industrialized regions. Our results show the need to include the effects of changing atmospheric composition, beyond CO2, to assess future dynamics of carbon-climate feedbacks not currently considered in earth system/climate modelling.

Anti-contactin-associated protein-2 encephalitis: relevance of antibody titres, presentation and outcome.

BACKGROUND AND PURPOSE: To clarify the relevance of titres of IgG antibodies against contactin-associated protein-2 (CASPR2) in diagnosing anti-CASPR2 encephalitis and to describe features and outcomes. METHODS: This was a retrospective analysis of 64 patients with CASPR2 antibodies, categorized independently as 'autoimmune encephalitis' or 'other disease'. Logistic regression methods were performed to identify potential predictors of 'autoimmune encephalitis' in addition to CASPR2 antibodies. RESULTS: An upfront CASPR2 antibody serum titre cut-off at ≥1:200 had a diagnostic sensitivity of 85% and a specificity of 81%. Logistic regression analyses indicated that, in addition to titre, encephalitic magnetic resonance imaging (MRI) was a significant predictor of 'autoimmune encephalitis' (Nagelkerke's R2 = 0.81, P < 0.001) with high sensitivity (84%) and very high specificity (100%). Patients with CASPR2 antibodies and an estimated probability of >70% of having anti-CASPR2 encephalitis (n = 22) had limbic encephalitis (n = 18, one patient plus ataxia), Morvan syndrome (n = 2) or a hyperkinetic movement disorder (n = 2). Median modified Rankin score (mRS) at diagnosis was 3 (range 1-4). Twenty patients were male; median age was 64 (range 54-75) years; 5/15 patients with cerebrospinal fluid data had intrathecal CASPR2 antibody synthesis, and 12/19 with follow-ups >3 months (median 12 months, range 4-43 months) improved by ≥1 mRS point resulting in a median mRS of 2 (range 0-6; one death; all but one having received immunotherapy); and 2/15 patients with follow-up MRI developed hippocampal atrophy. CONCLUSIONS: Only higher CASPR2 serum antibody titres indicate anti-CASPR2 encephalitis, and diagnostic accuracy increases if MRI findings are considered. Anti-CASPR2 encephalitis has characteristic features and a favourable outcome with immunotherapy.

Added sensitivity of component-resolved diagnosis in hymenoptera venom-allergic patients with elevated serum tryptase and/or mastocytosis.

BACKGROUND: Anaphylaxis caused by hymenoptera venom allergy is associated with elevation of baseline serum tryptase (sBT) and/or mastocytosis in about 5% of patients. Up to now, no information has become available on single venom allergen sIgE reactivity and the usefulness of component-resolved approaches to diagnose this high-risk patient group. To address the component-resolved sIgE sensitization pattern and diagnostic sensitivity in hymenoptera venom-allergic patients with elevated sBT levels and/or mastocytosis, a panel of yellow jacket and honeybee venom allergens was applied on a widely used IgE immunoassay platform. METHODS: Fifty-three patients with mastocytosis and/or elevated sBT tryptase level and systemic reactions to hymenoptera venoms were analyzed for their IgE reactivity to recombinant yellow jacket and honeybee venom allergens by Immulite3 g. RESULTS: sIgE reactivity to Ves v 1, Ves v 5, Api m 1 to Api m 4 and Api m 10 was found at a similar frequency in hymenoptera venom-allergic patients with and without elevated sBT levels and/or mastocytosis. However, the use of the recombinant allergens and a diagnostic cutoff of 0.1 kUA /L allowed the diagnosis of patients with otherwise undetectable IgE to venom extract. The diagnostic sensitivity of yellow jacket venom allergy using the combination of Ves v 1 and Ves v 5 was 100%. CONCLUSIONS: In high-risk patients with elevated sBT levels and/or mastocytosis, the use of molecular components and decreasing the threshold sIgE level to 0.1 kUA /L may be needed to avoid otherwise undetectable IgE to hymenoptera venom extracts in about 8% of such patients.

Api m 10, a genuine A. mellifera venom allergen, is clinically relevant but underrepresented in therapeutic extracts.

BACKGROUND: Generalized systemic reactions to stinging hymenoptera venom constitute a potentially fatal condition in venom-allergic individuals. Hence, the identification and characterization of all allergens is imperative for improvement of diagnosis and design of effective immunotherapeutic approaches. Our aim was the immunochemical characterization of the carbohydrate-rich protein Api m 10, an Apis mellifera venom component and putative allergen, with focus on the relevance of glycosylation. Furthermore, the presence of Api m 10 in honeybee venom (HBV) and licensed venom immunotherapy preparations was addressed. METHODS: Api m 10 was produced as soluble, aglycosylated protein in Escherichia coli and as differentially glycosylated protein providing a varying degree of fucosylation in insect cells. IgE reactivity and basophil activation of allergic patients were analyzed. For detection of Api m 10 in different venom preparations, a monoclonal human IgE antibody was generated. RESULTS: Both, the aglycosylated and the glycosylated variant of Api m 10 devoid of cross-reactive carbohydrate determinants (CCD), exhibited IgE reactivity with approximately 50% of HBV-sensitized patients. A corresponding reactivity could be documented for the activation of basophils. Although the detection of the native protein in crude HBV suggested content comparable to other relevant allergens, three therapeutical HBV extracts lacked detectable amounts of this component. CONCLUSION: Api m 10 is a genuine allergen of A. mellifera venom with IgE sensitizing potential in a significant fraction of allergic patients independent of CCD reactivity. Thus, Api m 10 could become a key element for component-resolved diagnostic tests and improved immunotherapeutic approaches in hymenoptera venom allergy.

Association between structural abnormalities and fMRI response in the amygdala in patients with temporal lobe epilepsy.

OBJECTIVE: The goal of this study was to investigate whether dysplastic amygdalae show an impaired response as revealed by functional MRI (fMRI). METHODS: A fearful face fMRI paradigm using video sequences, as we have recently applied, was used in 25 patients with temporal lobe epilepsy (TLE): 24 had mesial TLE (14 right-, nine left-sided, one bilateral); one left lateral neocortical TLE. T1-, T2-weighted and fluid attenuated inversion recovery (FLAIR) MRI sequences were assessed for the detection and categorisation of structural amygdalar abnormalities according to size and MR signal intensity. Of the 25 patients, five patients had probable dysplastic amygdala (pDA): two right- and three left-sided. RESULTS: A fearful face paradigm led to significant amygdalar activation in all but one patient (p<0.05). In 15 (60%) of the patients amygdalar activation was found contralateral and in four (16%) ipsilateral to the side of seizure onset. Bilateral amygdalar activation was registered in five (20%) patients. In two patients with right-sided and one with left-sided pDA, fMRI activation was observed only in the contralateral amygdala. In two out of three patients with left-sided pDA we found significant ipsilateral amygdalar fMRI-responses. CONCLUSION: Unilateral pDA does not necessarily affect the amygdalar fMRI BOLD-response.

Codon-optimization of the hemagglutinin gene from the novel swine origin H1N1 influenza virus has differential effects on CD4(+) T-cell responses and immune effector mechanisms following DNA electroporation in mice.

DNA electroporation is a powerful vaccine strategy that could be rapidly adapted to address emerging viruses. We therefore compared cellular and humoral immune responses in mice vaccinated with DNA expression plasmids encoding either the wildtype or a codon-optimized sequence of hemagglutinin from the novel swine origin H1N1 influenza virus. While expression of HA from the wildtype sequence was hardly detectable, the H1N1 hemagglutinin was well expressed from the codon-optimized sequence. Despite poor expression of the wildtype sequence, both plasmids induced similar levels of CD4(+) T-cell responses. However, CD8(+) T-cell and antibody responses were substantially higher after immunization with the codon-optimized DNA vaccine. Thus, efficient induction of immune effector mechanisms against HA of the novel H1N1 influenza virus requires codon-optimization of the DNA vaccines. Since DNA vaccines and several viral vector vaccines employ the same cellular RNA-Polymerase II dependent expression pathway, the poor expression levels from wildtype HA sequences might also limit the induction of immune effector mechanisms by such viral vector vaccines.

Immunogenicity and efficacy of intradermal tattoo immunization with adenoviral vector vaccines.

Since intradermal delivery of DNA vaccines via tattoo device is an efficient strategy to induce antigen-specific immune responses, we evaluated this route of application for adenoviral vector vaccines in mice. Although expression levels were comparable after i.d. injection and i.d. tattoo immunization of adenoviral vectors, the tattoo application confined antigen expression to the upper layers of the dermis. Both delivery approaches resulted in strong CD8+ T-cell and humoral immune responses to three different antigens and conferred protection against mucosal challenge with respiratory syncytial virus. However, in contrast to results obtained with DNA vaccines, intradermal tattoo immunization did not provide any obvious advantage in comparison to simple intradermal injection of the adenoviral vector vaccines.

Contributions of climate, leaf area index and leaf physiology to variation in gross primary production of six coniferous forests across Europe: a model-based analysis.

Gross primary production (GPP) is the primary source of all carbon fluxes in the ecosystem. Understanding variation in this flux is vital to understanding variation in the carbon sink of forest ecosystems, and this would serve as input to forest production models. Using GPP derived from eddy-covariance (EC) measurements, it is now possible to determine the most important factor to scale GPP across sites. We use long-term EC measurements for six coniferous forest stands in Europe, for a total of 25 site-years, located on a gradient between southern France and northern Finland. Eddy-derived GPP varied threefold across the six sites, peak ecosystem leaf area index (LAI) (all-sided) varied from 4 to 22 m(2) m(-2) and mean annual temperature varied from -1 to 13 degrees C. A process-based model operating at a half-hourly time-step was parameterized with available information for each site, and explained 71-96% in variation between daily totals of GPP within site-years and 62% of annual total GPP across site-years. Using the parameterized model, we performed two simulation experiments: weather datasets were interchanged between sites, so that the model was used to predict GPP at some site using data from either a different year or a different site. The resulting bias in GPP prediction was related to several aggregated weather variables and was found to be closely related to the change in the effective temperature sum or mean annual temperature. High R(2)s resulted even when using weather datasets from unrelated sites, providing a cautionary note on the interpretation of R(2) in model comparisons. A second experiment interchanged stand-structure information between sites, and the resulting bias was strongly related to the difference in LAI, or the difference in integrated absorbed light. Across the six sites, variation in mean annual temperature had more effect on simulated GPP than the variation in LAI, but both were important determinants of GPP. A sensitivity analysis of leaf physiology parameters showed that the quantum yield was the most influential parameter on annual GPP, followed by a parameter controlling the seasonality of photosynthesis and photosynthetic capacity. Overall, the results are promising for the development of a parsimonious model of GPP.

Broad spectrum antiviral fractions from the lichen Ramalina farinacea (L.) Ach.

BACKGROUND: An ethylacetate-soluble fraction (ET4) from the lichen Ramalina farinacea has previously been shown to inhibit the infectivity of lentiviral and adenoviral vectors, as well as wild-type HIV-1. We now determined the antiviral activity of ET4 against other wild-type viruses, including the herpes simplex virus type 1 (HSV-1) and the respiratory syncytial virus (RSV). METHODS: Wild-type HIV-1, HSV-1 or RSV were pre-incubated with various concentrations of ET4 for 30 min at 37 degrees C before adding to P4CCR5 indicator cell line (HIV-1), ELVIS TM indicator cell line (HSV-1) or HEp2 cell line (RSV) in 96-well microtitre plates. Controls contain virus alone without ET4. The anti-HIV and anti-HSV activities were quantified by estimating beta-galactosidase expression of the respective indicator cell lines while the anti-RSV activity was determined via an immunofluorescent technique, employing monoclonal mouse antibody against the P-protein of RSV. Toxicity of ET4 to cell lines was evaluated in parallel using either the BrdU incorporation method or the MTT method. The effect of ET4 on the enzymatic activity of HIV-1 reverse transcriptase was also evaluated using a chemiluminescent reverse transcriptase assay. Bioassay-guided fractionation of the whole methanol extract of R. farinacea involved sequential screening of HPLC fractions using a vector-based assay technique. RESULTS: ET4 inhibited HSV-1 and RSV potently (IC(50)=6.09 and 3.65 microg/ml, respectively). Time-of-addition studies suggest that both entry and post-entry steps of the HIV-1 replication cycle and the entry step of the RSV replication cycle are targeted. Furthermore, ET4 inhibited HIV-1 reverse transcriptase with an IC(50) of 0.022 microg/ml. Bioassay-guided fractionation of ET4 led to the identification sub-fraction rfO, with activity against lentiviral vector and HIV-1 (RNA viruses) but not against HSV-1 (DNA virus) and sub-fraction rfM, with activity against HSV-1 but not against the lentiviral vector. CONCLUSIONS: ET4 represents a novel fraction from the lichen R. farinacea with broad spectrum antiviral activity against DNA viruses (adenovirus and HSV-1) and RNA viruses (HIV-1 and RSV). The effect against DNA and RNA viruses is mediated by different sub-fractions within R. farinacea.

Potential anti-respiratory syncytial virus lead compounds from Aglaia species.

Although the global prevalence of respiratory syncytial virus (RSV) infection, especially among infants and young children is on the increase, there are only limited therapeutic options for treatment of this disease. Therefore, the search for novel antiviral inhibitors of RSV has become more intensive. In a pilot screening of eighteen compounds from various Aglaia species for anti-RSV activity, we identified dammarenolic acid (ignT1), aglaiol (dupT1) and niloticin (cucT1) as potential anti-RSV compounds, with ignT1 being the most potent. Methylation of ignT1 results in a complete loss of anti-RSV activity. Time of addition studies reveal that both ignT1 and dupT1 target the RSV replication at a post-entry stage, although ignT1 was more potent. Dammarenolic acid (ignT1) was also more cytotoxic than aglaiol (dupT1). By carrying out parallel anti-RSV screening with aphidicolin (a highly cytotoxic diterpenoid) and ignT1, we showed that although aphidicolin was more cytotoxic than ignT1, it had virtually no anti-RSV activity. Therefore, dammarenolic acid, aglaiol and niloticin demonstrate potent anti-RSV activity that shouldbe explored further in the current search for anti-RSV therapeutic agents.

Automated detection and quantitation of bacterial RNA by using electrical microarrays.

Low-density electrical 16S rRNA specific oligonucleotide microarrays and an automated analysis system have been developed for the identification and quantitation of pathogens. The pathogens are Escherichia coli, Pseudomonas aeruginosa, Enterococcus faecalis, Staphylococcus aureus, and Staphylococcus epidermidis, which are typically involved in urinary tract infections. Interdigitated gold array electrodes (IDA-electrodes), which have structures in the nanometer range, have been used for very sensitive analysis. Thiol-modified oligonucleotides are immobilized on the gold IDA as capture probes. They mediate the specific recognition of the target 16S rRNA by hybridization. Additionally three unlabeled oligonucleotides are hybridized in close proximity to the capturing site. They are supporting molecules, because they improve the RNA hybridization at the capturing site. A biotin labeled detector oligonucleotide is also allowed to hybridize to the captured RNA sequence. The biotin labels enable the binding of avidin alkaline phophatase conjugates. The phosphatase liberates the electrochemical mediator p-aminophenol from its electrically inactive phosphate derivative. The electrical signals were generated by amperometric redox cycling and detected by a unique multipotentiostat. The read out signals of the microarray are position specific current and change over time in proportion to the analyte concentration. If two additional biotins are introduced into the affinity binding complex via the supporting oligonucleotides, the sensitivity of the assays increase more than 60%. The limit of detection of Escherichia coli total RNA has been determined to be 0.5 ng/microL. The control of fluidics for variable assay formats as well as the multichannel electrical read out and data handling have all been fully automated. The fast and easy procedure does not require any amplification of the targeted nucleic acids by PCR.

The second cysteine protease inhibitor, EhICP2, has a different localization in trophozoites of Entamoeba histolytica than EhICP1.

The genome of Entamoeba histolytica contains two genes encoding inhibitors of cysteine proteases of the chagasin family. In contrast to that of EhICP1, the derived primary structure of the second inhibitor, EhICP2, possesses a typical N-terminal signal sequence. Processed EhICP2 is as weakly related to amoebiasin-1 (27% identity) as to chagasin (identity 30%), indicating a different evolutionary origin of both amebic genes. By Northern blots, we confirmed the expression of the ehicp2 gene, and in Western blots, the presence of the 11.5-kDa protein in trophozoite extracts was demonstrated. The inhibitor localized to large intracellular structures clearly differs from those containing EhICP1 as shown by indirect immunofluorescence. Recombinant EhICP2 significantly inhibited the cysteine protease activity of the amebic cell extract but with a lower extent than EhICP1. An overlay assay using a crude trophozoite extract demonstrated binding affinity of the amebic cysteine protease EhCP1 to EhICP2.

DNA hybridization detection on electrical microarrays using coulostatic pulse technique.

We demonstrated a novel application of transient coulostatic pulse technique for the detection of label free DNA hybridization on nm-sized gold interdigitated ultramicroelectrode arrays (Au-IDA) made in silicon technology. The array consists of eight different positions with an Au-IDA pair at each position arranged on the Si-based Biochip. Immobilization of capture probes onto the Au-IDA was accomplished by self-assembling of thiol-modified oligonucleotides. Target hybridization was indicated by a change in the magnitude of the time dependant potential relaxation curve in presence of electroactive Fe(CN)(6)(3-) in the phosphate buffer solution. While complementary DNA hybridization showed 50% increase in the relaxation potential, the non-complementary DNA showed a negligible change. A constant behaviour was noted for all positions. The dsDNA specific intercalating molecule, methylene blue, was found to be enhancing the discrimination effect. The changes in the relaxation potential curves were further corroborated following the ELISA like experiments using ExtraAvidine alkaline phosphatase labelling and redox recycling of para-aminophenol phosphate at IDAs. The coulostatic pulse technique was shown to be useful for identifying DNA sequences from brain tumour gene CK20, human herpes simplex virus, cytomegalovirus, Epstein-Barr virus and M13 phage. Compared to the hybridization of short chain ONTs (27 mers), the hybridization of long chain M13 phage DNA showed three times higher increase in the relaxation curves. The method is fast enough to monitor hybridization interactions in milli or microsecond time scales and is well suitable for miniaturization and integration compared to the common impedance techniques for developing capacitative DNA sensors.

Amygdala fMRI lateralizes temporal lobe epilepsy.

OBJECTIVE: To characterize the clinical value of an fMRI task activating the amygdala in controls and patients with mesial temporal lobe epilepsy (MTLE). METHODS: A fearful face fMRI paradigm using video sequences was developed and investigated in 17 patients with epilepsy (12 had MTLE [6 right- and 6 left-sided]) and 17 healthy control subjects. Reproducibility was demonstrated by reimaging 12 of the control subjects. In addition, parahippocampal activation was measured using Roland's Hometown Walking Task within the same session in all patients and in nine of the control subjects. RESULTS: A fearful face paradigm led to significant amygdala activation (p < 0.001) in all subjects. Amygdala activation was bilateral in control subjects and clearly lateralized in patients with MTLE. Dissociated amygdala and parahippocampal activation was found in three MTLE patients. A combination of results from both fMRI paradigms improved the lateralization of the side of seizure onset in patients with MTLE. CONCLUSIONS: fMRI activation of the amygdala evoked by an animated fearful face paradigm is strong, reproducible, and specific in individual subjects. The combination of the fearful face paradigm and Roland's Hometown Walking Task provides a more reliable presurgical mapping of mesial temporal lobe structures.

In vitro pharmacodynamic evaluation of antiviral medicinal plants using a vector-based assay technique.

AIMS: Medicinal plants are increasingly being projected as suitable alternative sources of antiviral agents. The development of a suitable in vitro pharmacodynamic screening technique could contribute to rapid identification of potential bioactive plants and also to the standardization and/or pharmacokinetic-pharmacodynamic profiling of the bioactive components. METHODS AND RESULTS: Recombinant viral vectors (lentiviral, retroviral and adenoviral) transferring the firefly luciferase gene were constructed and the inhibition of viral vector infectivity by various concentrations of plant extracts was evaluated in HeLa or Hep2 cells by measuring the changes in luciferase activity. Cytotoxicity of the extracts was evaluated in parallel on HeLa or Hep2 cells stably expressing luciferase. Amongst the 15 extracts screened, only the methanol (ME) and the ethyl acetate (ET) fractions of the lichen, Ramalina farinacea specifically reduced lentiviral and adenoviral infectivity in a dose-dependent manner. Further, chromatographic fractionation of ET into four fractions (ET1-ET4) revealed only ET4 to be selectively antiviral with an IC50 in the 20 microg ml(-1) range. Preliminary mechanistic studies based on the addition of the extracts at different time points in the viral infection cycle (kinetic studies) revealed that the inhibitory activity was highest if extract and vectors were preincubated prior to infection, suggesting that early steps in the lentiviral or adenoviral replication cycle could be the major target of ET4. Inhibition of wild-type HIV-1 was also observed at a 10-fold lower concentration of the extract. CONCLUSIONS: The vector-based assay is a suitable in vitro pharmacodynamic evaluation technique for antiviral medicinal plants. The technique has successfully demonstrated the presence of antiviral principles in R. farinacea. SIGNIFICANCE AND IMPACT OF STUDY: Potential anti-HIV medicinal plants could rapidly be evaluated with the reported vector-based technique. The lichen, R. farinacea could represent a lead source of antiviral substances and is thus worthy of further studies.

Label-free impedance detection of oligonucleotide hybridisation on interdigitated ultramicroelectrodes using electrochemical redox probes.

The direct detection of oligodeoxynucleotide (ODN) hybridisation using electrochemical impedance spectroscopy was made on interdigitated array (IDA) gold (Au) ultramicroelectrodes manufactured by silicon technology. The immobilisation of single stranded ODNs (ssODNs) was accomplished by self-assembling of thiol-modified ODNs onto an Au-electrode surface. Faradaic impedance was measured in the presence of K(3)[Fe(CN)(6)]. Double strand formation was identified by a decrease of approximately 50% in impedance in the low frequency region in the presence of K(3)[Fe(CN)(6)], compared to the spectrum of single stranded ODN. The frequency dependent diffusion of Fe(CN)(6)(3-) ions through defects in the ODN monolayer determines the impedance of Au-ssODN surface. The influence of DNA intercalator methylene blue on the impedance of both, single and double strands, was examined along with K(3)[Fe(CN)(6)] and confirmed by cyclic voltammetry. The layer densities and the hybridisation have been further corroborated by chronoamperometric redox recycling of para-aminophenol (p-AP) in ELISA like experiments. It can be concluded, that a performed impedance spectroscopy did not change the layer density. The impedance spectroscopy at ultramicroelectrodes combined with faradaic redox reactions enhances the impedimetric detection of DNA hybridisation on IDA platforms.

Europe-wide reduction in primary productivity caused by the heat and drought in 2003.

Future climate warming is expected to enhance plant growth in temperate ecosystems and to increase carbon sequestration. But although severe regional heatwaves may become more frequent in a changing climate, their impact on terrestrial carbon cycling is unclear. Here we report measurements of ecosystem carbon dioxide fluxes, remotely sensed radiation absorbed by plants, and country-level crop yields taken during the European heatwave in 2003. We use a terrestrial biosphere simulation model to assess continental-scale changes in primary productivity during 2003, and their consequences for the net carbon balance. We estimate a 30 per cent reduction in gross primary productivity over Europe, which resulted in a strong anomalous net source of carbon dioxide (0.5 Pg C yr(-1)) to the atmosphere and reversed the effect of four years of net ecosystem carbon sequestration. Our results suggest that productivity reduction in eastern and western Europe can be explained by rainfall deficit and extreme summer heat, respectively. We also find that ecosystem respiration decreased together with gross primary productivity, rather than accelerating with the temperature rise. Model results, corroborated by historical records of crop yields, suggest that such a reduction in Europe's primary productivity is unprecedented during the last century. An increase in future drought events could turn temperate ecosystems into carbon sources, contributing to positive carbon-climate feedbacks already anticipated in the tropics and at high latitudes.

Sensory gating in the human hippocampal and rhinal regions.

OBJECTIVE: The objective of this work was to ascertain if sensory gating can be demonstrated within the human medial temporal lobe. METHODS: Eight patients with intractable epilepsy with depth electrodes implanted in the medial temporal lobe for pre-surgery evaluation underwent evoked response recording to auditory paired-stimuli (S1-S2). Each of the eight subjects had a diagnosis of left medial temporal lobe epilepsy (MTLE). RESULTS: Data from the non-focal right hippocampi revealed a large negative response on S1 (starting at about 190 ms and lasting for approximately 300 ms from stimulus onset). Rhinal region recordings revealed a positive response (starting at about 240 ms with a rapid incline, followed by a long-lasting decline). A significant attenuation of both responses to S2 stimuli was observed. CONCLUSIONS: Data are suggestive of an involvement of the human medial temporal lobe in the processing of simple auditory information which occurs in a time frame later than the neocortical auditory evoked components. The exact role of these anatomical structures in the sensory gating process remains to be defined. SIGNIFICANCE: This study provides the first evidence of an activation of the rhinal cortex after simple auditory stimulation and provides new evidence that the activation of the medial temporal lobe structures occurs at a later stage than that of the neocortex.

Rapid detection of viruses using electrical biochips and anti-virion sera.

AIMS: Rapid detection and quantification of viruses is crucial in clinical practice, veterinary medicine, agriculture, basic research as well as in biotechnological factories. However, although various techniques were described and are currently used, development of more rapid, more sensitive and quantitative methods seems to be still important. METHODS AND RESULTS: Here we describe a method for rapid detection of viruses (using bacteriophages as model viruses), based on electrical biochip array technology with the use of antibodies against capsid proteins. CONCLUSIONS: Using the procedure developed in this work, we were able to detect 2 x 10(4) virions on the chip. The whole assay procedure takes c. 50 min and the assay is quantitative. SIGNIFICANCE AND IMPACT OF THE STUDY: This procedure may be useful in various approaches, including detection of bacteriophage contamination in bioreactors and possibly detection of toxin gene-bearing phages or other viruses in food samples.