Sources of errors and uncertainties in the assessment of forest soil carbon stocks at different scales-review and recommendations.

Spatially explicit knowledge of recent and past soil organic carbon (SOC) stocks in forests will improve our understanding of the effect of human- and non-human-induced changes on forest C fluxes. For SOC accounting, a minimum detectable difference must be defined in order to adequately determine temporal changes and spatial differences in SOC. This requires sufficiently detailed data to predict SOC stocks at appropriate scales within the required accuracy so that only significant changes are accounted for. When designing sampling campaigns, taking into account factors influencing SOC spatial and temporal distribution (such as soil type, topography, climate and vegetation) are needed to optimise sampling depths and numbers of samples, thereby ensuring that samples accurately reflect the distribution of SOC at a site. Furthermore, the appropriate scales related to the research question need to be defined: profile, plot, forests, catchment, national or wider. Scaling up SOC stocks from point sample to landscape unit is challenging, and thus requires reliable baseline data. Knowledge of the associated uncertainties related to SOC measures at each particular scale and how to reduce them is crucial for assessing SOC stocks with the highest possible accuracy at each scale. This review identifies where potential sources of errors and uncertainties related to forest SOC stock estimation occur at five different scales-sample, profile, plot, landscape/regional and European. Recommendations are also provided on how to reduce forest SOC uncertainties and increase efficiency of SOC assessment at each scale.

Pentacene on Ni(111): room-temperature molecular packing and temperature-activated conversion to graphene.

We investigate, using scanning tunnelling microscopy, the adsorption of pentacene on Ni(111) at room temperature and the behaviour of these monolayer films with annealing up to 700 °C. We observe the conversion of pentacene into graphene, which begins from as low as 220 °C with the coalescence of pentacene molecules into large planar aggregates. Then, by annealing at 350 °C for 20 minutes, these aggregates expand into irregular domains of graphene tens of nanometers in size. On surfaces where graphene and nickel carbide coexist, pentacene shows preferential adsorption on the nickel carbide phase. The same pentacene to graphene transformation was also achieved on Cu(111), but at a higher activation temperature, producing large graphene domains that exhibit a range of moiré superlattice periodicities.

Tip-induced C-H activation and oligomerization of thienoanthracenes.

The tip of a scanning tunneling microscope (STM) can be used to dehydrogenate freely-diffusing tetrathienoanthracene (TTA) molecules on Cu(111), trapping the molecules into metal-coordinated oligomeric structures. The process proceeds at bias voltages above ~3 V and produces organometallic structures identical to those resulting from the thermally-activated cross-coupling of a halogenated analogue. The process appears to be substrate dependent: no oligomerization was observed on Ag(111) or HOPG. This approach demonstrates the possibility of controlled synthesis and nanoscale patterning of 2D oligomer structures on selected surfaces.

[Recommendations for the clinical use of motor evoked potentials in multiple sclerosis]. / Recomendaciones para la utilización clínica del estudio de potenciales evocados motores en la esclerosis múltiple.

OBJECTIVE: To establish clinical guidelines for the clinical use and interpretation of motor evoked potentials (MEP) in diagnosing and monitoring patients with multiple sclerosis (MS). Recommendations for MEP use and interpretation will help us rationalise and optimise resources used in MS patient diagnosis and follow up. METHOD: We completed an extensive literature review and pooled our own data to produce a consensus statement with recommendations for the clinical use of MEPs in the study of MS. RESULTS: MEPs, in addition to spinal and cranial magnetic resonance imaging (MRI), help us diagnose and assess MS patients whose disease initially presents as spinal cord syndrome and those with non-specific brain MRI findings, or a normal brain MRI and clinical signs of MS. CONCLUSIONS: Whenever possible, a multimodal evoked potential study should be performed on patients with suspected MS in order to demonstrate involvement of the motor pathway which supports a diagnosis of dissemination in space.

Serum endothelial adhesion molecules levels correlate with lesion burden in multiple sclerosis patients treated with interferon beta-1b.

The levels of serum-soluble intracellular adhesion molecule-1 and soluble endothelial-leukocyte adhesion molecule-1, and the Gadolinium-enhanced T1-weighted MRI were studied in a group of patients with relapsing-remitting multiple sclerosis treated with interferon beta-1b and compared to a non-treated control group. The levels of serum-soluble intracellular adhesion molecule-1 and soluble endothelial-leukocyte adhesion molecule-1 increased, after three months treatment, as compared to baseline and the non-treated MS patients. A significant correlation was found in the treated group between serum-soluble endothelial-leukocyte adhesion molecule-1 and the lesion area in the Gadolinium-enhancing (T2 weighted scan) MRI.

The oxidation-reduction state of serum proteins in multiple sclerosis patients: effect of interferon beta-1b.

The concentration of reduction equivalents in serum was studied in a cohort of healthy individuals, in a group of multiple sclerosis (MS) patients undergoing treatment with interferon beta-1b and another group of MS patients who refused treatment with interferon beta-1b. Two classes of sulfhydryl groups were detectable in serum: (1) the uncovered sulfhydryls, accessible to the oxidation-reduction substrate 5,5-dithiobis-(-2-nitrobenzoic acid) (DTNB); and (2) the hidden sulfhydryls that required previous heat denaturation of serum proteins to become accessible to DTNB. The concentration of the reduced form of both the uncovered- and hidden-type of sulfhydryls was higher in the serum of MS patients than in healthy individuals. Interferon beta-1b lowered the plasma concentration of the uncovered reduced sulfhydryls after 3 months of treatment. This was in contrast to a minor effect of interferon beta-1b in the hidden-form of sulfhydryl groups. The results suggest that the concentration of reduced sulfhydryls is a biochemical marker of the in vivo oxidation/reduction reactions in MS.

[Changes in lymphocyte subsets s and treatment with beta interferon in active multiple sclerosis]. / Evolución de subpoblaciones linfocitarias y tratamiento con interferón beta en la esclerosis múltiple activa.

INTRODUCTION: We report that interferon beta decreases CD8 T cells percentage and increases CD4/CD8 cell's rate in vivo in Multiple Sclerosis (MS) patients. PATIENTS AND METHODS: We studied 40 patients (22 women and 18 men) with clinically definite active MS who received IFN beta. Twenty-six were treated with nIFN (9 MU/week) and 14 with rIFN (28 MU/week). All patients except two with secondary progressive forms presented relapsing remitting courses. Mean age and mean age at onset were 36.5 +/- 9 and 27.8 +/- 7 years respectively. Mean EDSS score was 2.96 +/- 1.8. Patients were reviewed at four weeks and every eight weeks and periodical studies of immunity were performed. T cell subpopulations (CD3, CD4, CD8 and NK) were studied byflow cytometry. RESULTS: The evolution of CD8 T cell percentage showed a statistically significant decrease in all blood samples after 20 weeks of treatment with rIFN (24.3 +/- 8 vs 34.7 +/- 5 in the control group) and after 36 weeks for nIFN beta group (25.7 +/- 6 vs 33.0 +/- 4 in the control group). No changes were detected in CD4 T cell subset. The evolution of CD4/CD8 T cell rate showed an increase over the cut-off (2.200) in all blood samples after 20 weeks of treatment with rIFN (2.302 +/- 1.12, 2.332 +/- 0.99 and 2.488 +/- 1.61 for 20, 28 and 36 weeks respectively) and after 52 weeks for nIFN beta group (2.128 +/- 1.07, 2.346 +/- 1.09 and 3.168 +/- 3.87 for 52, 60 and 68 weeks respectively). CONCLUSIONS: Both nIFN and rIFN beta are able in vivo to decrease CD8 percentage of T cells and increase CD4/CD8+ T cell rate. The increase in the rate is produced earlier in the rIFN treated group.

Human lymphocytotoxic monoclonal autoantibodies from a highly sensitized renal dialysis patient.

A panel of 5 human monoclonal autolymphocytotoxic antibodies (IRM-3, IRM-4, IRM-7, IRM-8, and IRM-10) of the IgM class was established from a highly sensitized renal dialysis patient (IRM), by the generation of mouse-human heterohybridomas. This panel was screened for reactivity against foreign and autoantigens by ELISA, and for reactivity against different tissue sections and HEp-2 slide preparations by indirect immunofluorescence. Cytotoxicity screening of heterohybridoma supernatants gave broad panel reactivity profiles, being cytotoxic against B cells from patient IRM and also against most B cells tested and less reactive with chronic lymphocytic leukemia B cells; T cells were the least sensitive target. Immunoblotting showed that monoclonal IRM displayed some heterogeneity in their binding profiles, although all of them recognized a cellular structure of 26 kDa. None of the heterohybridoma cell lines exhibited cytoplasmic nor surface staining with an anti-CD5 mAb. Results obtained showed that all the autolymphocytotoxic mAbs generated were also able to react against certain nuclear and cytoplasmic self-structures as well as foreign compounds. Monoclonal antibody IRM-7 and, to a lesser degree, IRM-10 exhibited multispecific properties similar to those observed for polyreactive or natural antibodies.

Induction of antihemagglutinin antibodies by polyclonal antiidiotype antibodies.

Antiidiotypic antibodies can be envisioned as an alternative approach in the development of vaccines against influenza virus, which exhibits natural antigenic variations. In our work, we obtained two polyclonal cross-reactive anti-Id antibodies against PY102, VM113, and VM202 mAbs, which in turn are specific respectively for PR8 virus and laboratory-induced virus variants (PY102-V1 and VM113-V1). With these cross-reactive anti-Id antibodies, we were able to elicit anti-HA antibodies in mice. In comparing the anti-HA antibody response in animals injected with anti-Id antibodies to those immunized with PR8 influenza virus, we demonstrated that the HI titer was higher after virus immunization and that the PR8 virus boost was more efficient in this group. Our results showed that the polyclonal cross-reactive anti-Id antibodies were more efficient than the individual anti-Ids at eliciting responses. At the same time, we demonstrated that PR8-primed T cells, cultured with B cells from animals immunized with anti-Id antibodies, were able to produce anti-PR8 antibodies subsequent to stimulation with influenza virus.