Optogenetic manipulation of \u3ci\u3eDrosophila\u3c/i\u3e larval motor circuits

In order to identify specific interneuron populations involved in muscle contraction in Drosophila larva through ontogenetic manipulation of motor neural circuits, I used GAL4-UAS system to generate larvae with channelrhodopsin2 embedded in cell membranes of interneuron populations of interest. I collected extracellular recordings of muscles during contraction in the dissected Drosophila larva. ChR2-stimulated action potentials lead to depolarizing potentials and contraction in muscle cells if the interneuron population of interest is important for Drosophila crawling neural circuits. I compared recordings from negative control, positive control, and experimental populations to identify which interneuron populations are sufficient to generate muscle excitation. These interneuron populations are putative constituents of the Drosophila larval crawling neural circuitry

Controls on microalgal community structures in cryoconite holes upon high Arctic glaciers, Svalbard

Glaciers are known to harbor surprisingly complex ecosystems. On their surface, distinct cylindrical holes filled with meltwater and sediments are considered as hot spots for microbial life. The present paper addresses possible biological interactions within the community of prokaryotic cyanobacteria and eukaryotic microalgae (microalgae) and relations to their potential grazers, additional to their environmental controls. Svalbard glaciers with substantial allochthonous input of material from local sources reveal high microalgal densities. Small valley glaciers with high sediment coverages and high impact of birds show high biomasses and support a high biological diversity. Invertebrate grazer densities do not show any significant negative correlation with microalgal abundances, but a positive correlation with eukaryotic microalgae. Most microalgae found in this study form large colonies ( 25 μm), which may protect them against invertebrate grazing. This finding rather indicates grazing as a positive control on eukaryotic microalgae by nutrient recycling. Density differences between the eukaryotic microalgae and prokaryotic cyanobacteria and their high distinction in RDA and PCA analyses indicate that these two groups are in strong contrast. Eukaryotic microalgae occurred mainly in unstable cryoconite holes with high sediment loads, high N : P ratios, and a high impact of bird guano, as a proxy for nutrients. In these environments autochthonous nitrogen fixation appears to be negligible. Selective wind transport of Oscillatoriales via soil and dust particles is proposed to explain their dominance in cryoconites further away from the glacier margins. We propose that, for the studied glaciers, nutrient levels related to recycling of limiting nutrients is the main factor driving variation in the community structure of microalgae and grazers

Reducing pesticide use in Iowa vineyards: Alternatives to herbicides for vineyard weed management

Mulches can play a role in vineyard management. This project explored the optimum uses and practices for applying various mulches to grape agroecosystems

There and back again: historical perspective and future directions for Vaccinium breeding and research studies

The genus Vaccinium L. (Ericaceae) contains a wide diversity of culturally and economically important berry crop species. Consumer demand and scientific research in blueberry (Vaccinium spp.) and cranberry (Vaccinium macrocarpon) have increased worldwide over the crops' relatively short domestication history (~100 years). Other species, including bilberry (Vaccinium myrtillus), lingonberry (Vaccinium vitis-idaea), and ohelo berry (Vaccinium reticulatum) are largely still harvested from the wild but with crop improvement efforts underway. Here, we present a review article on these Vaccinium berry crops on topics that span taxonomy to genetics and genomics to breeding. We highlight the accomplishments made thus far for each of these crops, along their journey from the wild, and propose research areas and questions that will require investments by the community over the coming decades to guide future crop improvement efforts. New tools and resources are needed to underpin the development of superior cultivars that are not only more resilient to various environmental stresses and higher yielding, but also produce fruit that continue to meet a variety of consumer preferences, including fruit quality and health related trait

Current Wildland Fire Patterns and Challenges in Europe : A Synthesis of National Perspectives

Changes in climate, land use, and land management impact the occurrence and severity of wildland fires in many parts of the world. This is particularly evident in Europe, where ongoing changes in land use have strongly modified fire patterns over the last decades. Although satellite data by the European Forest Fire Information System provide large-scale wildland fire statistics across European countries, there is still a crucial need to collect and summarize in-depth local analysis and understanding of the wildland fire condition and associated challenges across Europe. This article aims to provide a general overview of the current wildland fire patterns and challenges as perceived by national representatives, supplemented by national fire statistics (2009-2018) across Europe. For each of the 31 countries included, we present a perspective authored by scientists or practitioners from each respective country, representing a wide range of disciplines and cultural backgrounds. The authors were selected from members of the COST Action "Fire and the Earth System: Science & Society" funded by the European Commission with the aim to share knowledge and improve communication about wildland fire. Where relevant, a brief overview of key studies, particular wildland fire challenges a country is facing, and an overview of notable recent fire events are also presented. Key perceived challenges included (1) the lack of consistent and detailed records for wildland fire events, within and across countries, (2) an increase in wildland fires that pose a risk to properties and human life due to high population densities and sprawl into forested regions, and (3) the view that, irrespective of changes in management, climate change is likely to increase the frequency and impact of wildland fires in the coming decades. Addressing challenge (1) will not only be valuable in advancing national and pan-European wildland fire management strategies, but also in evaluating perceptions (2) and (3) against more robust quantitative evidence.Peer reviewe

Synthesis and characterization of nanoparticle suspensions: Towards quantitative surface-enhanced Raman spectroscopic sensing

Surface-enhanced Raman spectroscopy (SERS) is an ultrasensitive technique with applications ranging from in vitro and in vivo biological sensing to chemical and explosives detection. In this thesis, we explore the design and characterization of suspensions of nanoparticles prior to their use for SERS-based molecular sensing. A major problem in SERS-based measurements is that the signals are often not interpreted quantitatively. Measurements performed in suspension mimic the nanoprobe-to-nanoprobe optical interactions expected to be found in tissues with embedded nanoprobes while particle-level measurements of synthesized nanoparticles provide the molecular basis for calculations. We find that careful consideration of the localized surface plasmon resonance of SERS nanoprobes with respect to laser excitation wavelength is essential for maximizing detectable SERS signal. Additionally, the reporter molecule load per particle depends on synthesis conditions and the shape of the nanoparticles. Together, well-characterized suspensions can be used to understand the molecular and electromagnetic aspects of recorded SERS data

Heterogeneity of immunoregulatory T cells in human thyroid autoimmunity: influence of thyroid status.

Monoclonal antibodies of the OKT series were used to identify circulating T lymphocytes (OKT3+), their helper-inducer (OKT4+) and suppressor-cytotoxic (OKT8+) subsets and cells bearing Ia antigen (OKIa+) in 75 patients with thyroid autoimmune disorders, including 14 Graves' disease, 21 myxoedema, 20 asymptomatic thyroiditis, 12 Hashimoto's thyroiditis and eight simple goitre with superimposed thyroiditis. In the whole population of patients, a negative correlation was observed between the percentage of OKT8+ cells and serum free thyroxine levels whatever the type of thyroiditis. The percentage of OKT8+ cells was decreased in Graves' disease and increased in myxoedema while it reversed after adequate treatment of the two diseases. However, a trend to a decrease in the proportion of OKT8+ cells was still observed in treated Graves' disease and in all the other groups of thyroiditis with euthyroidism. The minor modifications observed for OKT3+ and OKT4+ cells were in relation with those of OKT8+ cells. There was an increased percentage of Ia+ cells in Graves' disease and in Hashimoto's thyroiditis partly reflecting the presence of activated lymphocytes. In conclusion, these data suggest first of all a direct influence of serum T4 on the distribution of circulating OKT8+ cells in addition to documenting the heterogeneity of T cell immunoregulatory factors