Mixing and Circulation in the Tropical Atlantic Cruise No. M98

July 01 – July 28, 2013 Fortaleza (Brazil) – Walvis Bay (Namibia

A Measurement of Coherent Neutral Pion Production in Neutrino Neutral Current Interactions in NOMAD

We present a study of exclusive neutral pion production in neutrino-nucleus Neutral Current interactions using data from the NOMAD experiment at the CERN SPS. The data correspond to $1.44 \times 10^6$ muon-neutrino Charged Current interactions in the energy range $2.5 \leq E_{\nu} \leq 300$ GeV. Neutrino events with only one visible $\pi^0$ in the final state are expected to result from two Neutral Current processes: coherent $\pi^0$ production, {\boldmath $\nu + {\cal A} \to \nu + {\cal A} + \pi^0$} and single $\pi^0$ production in neutrino-nucleon scattering. The signature of coherent $\pi^0$ production is an emergent $\pi^0$ almost collinear with the incident neutrino while $\pi^0$'s produced in neutrino-nucleon deep inelastic scattering have larger transverse momenta. In this analysis all relevant backgrounds to the coherent $\pi^0$ production signal are measured using data themselves. Having determined the backgrounds, and using the Rein-Sehgal model for the coherent $\pi^0$ production to compute the detection efficiency, we obtain {\boldmath $4630 \pm 522 (stat) \pm 426 (syst)$} corrected coherent-$\pi^0$ events with $E_{\pi^0} \geq 0.5$ GeV. We measure {\boldmath $\sigma (\nu {\cal A} \to \nu {\cal A} \pi^0) = [ 72.6 \pm 8.1(stat) \pm 6.9(syst) ] \times 10^{-40} cm^2/nucleus$}. This is the most precise measurement of the coherent $\pi^0$ production to date.Comment: 23 pages, 9 figures, accepted for publication in Phys. Lett.

Altered striatal endocannabinoid signaling in a transgenic mouse model of spinocerebellar ataxia type-3

Spinocerebellar ataxia type-3 (SCA-3) is the most prevalent autosomal dominant inherited ataxia. We recently found that the endocannabinoid system is altered in the post-mortem cerebellum of SCA-3 patients, and similar results were also found in the cerebellar and brainstem nuclei of a SCA-3 transgenic mouse model. Given that the neuropathology of SCA-3 is not restricted to these two brain regions but rather, it is also evident in other structures (e.g., the basal ganglia), we studied the possible changes to endocannabinoid signaling in the striatum of these transgenic mice. SCA-3 mutant mice suffer defects in motor coordination, balance and they have an abnormal gait, reflecting a cerebellar/brainstem neuropathology. However, they also show dystonia-like behavior (limb clasping) that may be related to the malfunction/deterioration of specific neurons in the striatum. Indeed, we found a loss of striatal projecting neurons in SCA-3 mutant mice, accompanied by a reduction in glial glutamate transporters that could potentially aggravate excitotoxic damage. In terms of endocannabinoid signaling, no changes in CB2 receptors were evident, yet an important reduction in CB1 receptors was detected by qPCR and immunostaining. The reduction in CB1 receptors was presumed to occur in striatal afferent and efferent neurons, also potentially aggravating excitotoxicity. We also measured the endocannabinoid lipids in the striatum and despite a marked increase in the FAAH enzyme in this area, no overall changes in these lipids were found. Collectively, these studies confirm that the striatal endocannabinoid system is altered in SCA-3 mutant mice, adding to the equivalent changes found in other strongly affected CNS structures in this type of ataxia (i.e.: the cerebellum and brainstem). These data open the way to search for drugs that might correct these changes.Funding: This study has been supported: (i) by MICINN (SAF2009-11847 and SAF2015-68580-C2-1-R), CIBERNED (CB06/05/0089) and “Fundación Eugenio Rodríguez Pascual”, to JFR; (ii) by the Research and Education Component of the Advancing a Healthier Wisconsin Endowment at the Medical College of Wisconsin, to CJH; and (iii) by Fundação para a Ciência e Tecnologia through the project POCI-01-0145-FEDER-016818 (PTDC/NEU-NMC/3648/2014) and co-financed by the Portuguese North Regional Operational Program (ON.2 – O Novo Norte) under the National Strategic Reference Framework (QREN), through the European Regional Development Fund (FEDER), to PM. Carmen Rodríguez-Cueto was a predoctoral fellow supported by FPI Program-Ministry of Science. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.info:eu-repo/semantics/publishedVersio

The Cool Farm Biodiversity metric: an evidence-based online tool to report and improve management of biodiversity at farm scale

Halting biodiversity loss and achieving food security are both aims of the United Nations 2030 Agenda for Sustainable Development, but there is complex interplay between them. Agriculture drives biodiversity loss, but biodiversity provides benefits to agriculture. There is substantial potential to develop ‘win-win’ solutions for biodiversity and people within productive farmland, by boosting wildlife that can be supported, whilst maintaining yield and other services. To achieve this, farmers need to be able to assess the impacts of their management on biodiversity at farm scale. While suitable tools exist to drive improvement in biodiversity management, none incorporates evidence on the effectiveness of specific management practices. In this study we present the Cool Farm Biodiversity metric, which generates a farm-scale action-based biodiversity management assessment, scored using expert judgements and expert assessment of experimental evidence. The metric is designed to be biome-specific, so it responds to conservation aims, ecosystem processes and farming systems in particular biomes. To demonstrate that the metric is responsive to changes in farm management, we present an example of use on a large arable farm from the temperate forest biome

A Search for Single Photon Events in Neutrino Interactions

We present a search for neutrino-induced events containing a single, exclusive photon using data from the NOMAD experiment at the CERN SPS where the average energy of the neutrino flux is $\simeq 25$ GeV. The search is motivated by an excess of electron-like events in the 200--475 MeV energy region as reported by the MiniBOONE experiment. In NOMAD, photons are identified via their conversion to $e^+e^-$ in an active target embedded in a magnetic field. The background to the single photon signal is dominated by the asymmetric decay of neutral pions produced either in a coherent neutrino-nucleus interaction, or in a neutrino-nucleon neutral current deep inelastic scattering, or in an interaction occurring outside the fiducial volume. All three backgrounds are determined {\it in situ} using control data samples prior to opening the `signal-box'. In the signal region, we observe {\bf 155} events with a predicted background of {\bf 129.2 $\pm$ 8.5 $\pm$ 3.3}. We interpret this as null evidence for excess of single photon events, and set a limit. Assuming that the hypothetical single photon has a momentum distribution similar to that of a photon from the coherent $\pi^0$ decay, the measurement yields an upper limit on single photon events, {\boldmath $< 4.0 \times 10^{-4}$} per \nm\ charged current event. Narrowing the search to events where the photon is approximately collinear with the incident neutrino, we observe {\bf 78} events with a predicted background of {\bf 76.6 $\pm$ 4.9 $\pm$ 1.9} yielding a more stringent upper limit, {\boldmath $< 1.6 \times 10^{-4}$} per \nm\ charged current event

Persistent effects of pre-Columbian plant domestication on Amazonian forest composition

The extent to which pre-Columbian societies altered Amazonian landscapes is hotly debated. We performed a basin-wide analysis of pre-Columbian impacts on Amazonian forests by overlaying known archaeological sites in Amazonia with the distributions and abundances of 85 woody species domesticated by pre-Columbian peoples. Domesticated species are five times more likely to be hyperdominant than non-domesticated species. Across the basin the relative abundance and richness of domesticated species increases in forests on and around archaeological sites. In southwestern and eastern Amazonia distance to archaeological sites strongly influences the relative abundance and richness of domesticated species. Our analyses indicate that modern tree communities in Amazonia are structured to an important extent by a long history of plant domestication by Amazonian peoples

Geography and ecology shape the phylogenetic composition of Amazonian tree communities.

Aim Amazonia hosts more tree species from numerous evolutionary lineages, both young and ancient, than any other biogeographic region. Previous studies have shown that tree lineages colonized multiple edaphic environments and dispersed widely across Amazonia, leading to a hypothesis, which we test, that lineages should not be strongly associated with either geographic regions or edaphic forest types. Location Amazonia. Taxon Angiosperms (Magnoliids; Monocots; Eudicots). Methods Data for the abundance of 5082 tree species in 1989 plots were combined with a mega-phylogeny. We applied evolutionary ordination to assess how phylogenetic composition varies across Amazonia. We used variation partitioning and Moran's eigenvector maps (MEM) to test and quantify the separate and joint contributions of spatial and environmental variables to explain the phylogenetic composition of plots. We tested the indicator value of lineages for geographic regions and edaphic forest types and mapped associations onto the phylogeny. Results In the terra firme and várzea forest types, the phylogenetic composition varies by geographic region, but the igapó and white-sand forest types retain a unique evolutionary signature regardless of region. Overall, we find that soil chemistry, climate and topography explain 24% of the variation in phylogenetic composition, with 79% of that variation being spatially structured (R2 = 19% overall for combined spatial/environmental effects). The phylogenetic composition also shows substantial spatial patterns not related to the environmental variables we quantified (R2 = 28%). A greater number of lineages were significant indicators of geographic regions than forest types. Main Conclusion Numerous tree lineages, including some ancient ones (>66 Ma), show strong associations with geographic regions and edaphic forest types of Amazonia. This shows that specialization in specific edaphic environments has played a long-standing role in the evolutionary assembly of Amazonian forests. Furthermore, many lineages, even those that have dispersed across Amazonia, dominate within a specific region, likely because of phylogenetically conserved niches for environmental conditions that are prevalent within regions.Na publicação: Joice Ferreira

Geographic patterns of tree dispersal modes in Amazonia and their ecological correlates

Unidad de excelencia María de Maeztu CEX2019-000940-MAim: To investigate the geographic patterns and ecological correlates in the geographic distribution of the most common tree dispersal modes in Amazonia (endozoochory, synzoochory, anemochory and hydrochory). We examined if the proportional abundance of these dispersal modes could be explained by the availability of dispersal agents (disperser-availability hypothesis) and/or the availability of resources for constructing zoochorous fruits (resource-availability hypothesis). Time period: Tree-inventory plots established between 1934 and 2019. Major taxa studied: Trees with a diameter at breast height (DBH) ≥ 9.55 cm. Location: Amazonia, here defined as the lowland rain forests of the Amazon River basin and the Guiana Shield. Methods: We assigned dispersal modes to a total of 5433 species and morphospecies within 1877 tree-inventory plots across terra-firme, seasonally flooded, and permanently flooded forests. We investigated geographic patterns in the proportional abundance of dispersal modes. We performed an abundance-weighted mean pairwise distance (MPD) test and fit generalized linear models (GLMs) to explain the geographic distribution of dispersal modes. Results: Anemochory was significantly, positively associated with mean annual wind speed, and hydrochory was significantly higher in flooded forests. Dispersal modes did not consistently show significant associations with the availability of resources for constructing zoochorous fruits. A lower dissimilarity in dispersal modes, resulting from a higher dominance of endozoochory, occurred in terra-firme forests (excluding podzols) compared to flooded forests. Main conclusions: The disperser-availability hypothesis was well supported for abiotic dispersal modes (anemochory and hydrochory). The availability of resources for constructing zoochorous fruits seems an unlikely explanation for the distribution of dispersal modes in Amazonia. The association between frugivores and the proportional abundance of zoochory requires further research, as tree recruitment not only depends on dispersal vectors but also on conditions that favour or limit seedling recruitment across forest types

Tissue engineering of functional articular cartilage: the current status

Osteoarthritis is a degenerative joint disease characterized by pain and disability. It involves all ages and 70% of people aged >65 have some degree of osteoarthritis. Natural cartilage repair is limited because chondrocyte density and metabolism are low and cartilage has no blood supply. The results of joint-preserving treatment protocols such as debridement, mosaicplasty, perichondrium transplantation and autologous chondrocyte implantation vary largely and the average long-term result is unsatisfactory. One reason for limited clinical success is that most treatments require new cartilage to be formed at the site of a defect. However, the mechanical conditions at such sites are unfavorable for repair of the original damaged cartilage. Therefore, it is unlikely that healthy cartilage would form at these locations. The most promising method to circumvent this problem is to engineer mechanically stable cartilage ex vivo and to implant that into the damaged tissue area. This review outlines the issues related to the composition and functionality of tissue-engineered cartilage. In particular, the focus will be on the parameters cell source, signaling molecules, scaffolds and mechanical stimulation. In addition, the current status of tissue engineering of cartilage will be discussed, with the focus on extracellular matrix content, structure and its functionality

Differing patterns of selection and geospatial genetic diversity within two leading Plasmodium vivax candidate vaccine antigens

Although Plasmodium vivax is a leading cause of malaria around the world, only a handful of vivax antigens are being studied for vaccine development. Here, we investigated genetic signatures of selection and geospatial genetic diversity of two leading vivax vaccine antigens--Plasmodium vivax merozoite surface protein 1 (pvmsp-1) and Plasmodium vivax circumsporozoite protein (pvcsp). Using scalable next-generation sequencing, we deep-sequenced amplicons of the 42 kDa region of pvmsp-1 (n = 44) and the complete gene of pvcsp (n = 47) from Cambodian isolates. These sequences were then compared with global parasite populations obtained from GenBank. Using a combination of statistical and phylogenetic methods to assess for selection and population structure, we found strong evidence of balancing selection in the 42 kDa region of pvmsp-1, which varied significantly over the length of the gene, consistent with immune-mediated selection. In pvcsp, the highly variable central repeat region also showed patterns consistent with immune selection, which were lacking outside the repeat. The patterns of selection seen in both genes differed from their P. falciparum orthologs. In addition, we found that, similar to merozoite antigens from P. falciparum malaria, genetic diversity of pvmsp-1 sequences showed no geographic clustering, while the non-merozoite antigen, pvcsp, showed strong geographic clustering. These findings suggest that while immune selection may act on both vivax vaccine candidate antigens, the geographic distribution of genetic variability differs greatly between these two genes. The selective forces driving this diversification could lead to antigen escape and vaccine failure. Better understanding the geographic distribution of genetic variability in vaccine candidate antigens will be key to designing and implementing efficacious vaccines