Long Range Optical Distance Sensors for Liquid Metal Free Surface Detection

For the demonstration of fusion power plant technology, DEMO dedicated materials are necessary to cope with the harsh environment of high energy neutrons. For this purpose, the international neutron irradiation facility for fusion materials IFMIF/DEMO Oriented Neutron Source (DONES) is planned to be built in Granda, Spain. In the DONES facility, a deuteron beam hitting the lithium target produces a high energy neutron flux. Due to the high-power density, the windowless target is a free surface liquid lithium flow in a duct with a concave backplate. In order to keep the heat released by the beam within the liquid lithium and to avoid its intrusion in the backplate, a stable configuration of the free surface flow with a setpoint layer thickness of 25 ± 1 mm is crucial. In particular, stable wave structures, so called wakes, which occur from accumulated impurities at the nozzle edge, can cause a critical local decrease in the layer thickness of more than 1 mm. Therefore, it is necessary to better understand the nature of these wakes and to be able to monitor the surface profile to shut down the beam in case of a critical thickness loss, but to avoid unintended shutdowns. In the context of this work, currently available optical sensors were tested on their capability of detecting a specular liquid metal surface at measurement distances of several meters. After an initial selection, two optical sensors were further considered. Experiments with the liquid metal alloy GaInSn and simulations with the software Blender of the selected optical sensors for their capability of measuring distances of liquid metal were conducted. The results showed a significant dependency of the measurement results on the waviness of the liquid metal surface. Nevertheless, it was possible to resolve the wavy liquid metal surface with a sufficient resolution to detect critical wake structures

On the embryonic and post-embryonic development of Pseudopallene sp. (Arthropoda, Pycnogonida) with special focus on neurogenesis and nervous system differentiation

Diese Arbeit befasst sich mit der Entwicklung der Asselspinne Pseudopallene sp. (Arthropoda, Pycnogonida). Die Morphogenese und Nervensystementwicklung werden mithilfe von Rasterelektronenmikroskopie, Histologie, Immunhistochemie und Genexpressionsstudien untersucht. Während der Proboscisbildung lassen sich keine Anzeichen für ein Labrum erkennen. Aufgrund des Fehlens von Palpen- und Ovigeranlagen und der frühen Entwicklung der Laufbeinsegmente ist kein embryonales Protonymphon-Stadium identifizierbar. Die Evolution verschiedener Larvenformen der Pycnogoniden wird im Hinblick auf phylogenetische Studien diskutiert. Die frühen Prozesse im Neuroektoderm zeigen Ähnlichkeiten zu Eucheliceraten und Myriapoden. Hierzu zählen das Fehlen morphologisch distinkter Zelltypen, die Bildung von Zellinternalisierungszentren, die Immigration vorwiegend post-mitotischer Ganglionzellen mit erhöhter Delta-Genexpression und fast ausschließlich tangentiale Zellteilungen. Anschließend bilden sich pro Neuromer ein Paar Invaginationen, was durch Vergrößerung der apikalen Zellen begleitet wird. Letztere sind aufgrund ihrer hohen Mitoseaktivität, ihres asymmetrischen Teilungsmodus und des anhaltenden Zuwachses der basalen Ganglionzellen als stammzellartige neuronale Vorläuferzellen identifizierbar. Hierauf basierend wird die Validität von stammzellartigen neuronalen Vorläuferzellen als Synapomorphie der Krebse und Insekten diskutiert. Zwei evolutionäre Szenarien zur Arthropoden-Neurogenese werden erörtert. In der post-embryonalen Phase lösen sich die invaginierten Zellregionen vom Ektoderm ab. Sie bilden apikal auf den Ganglien paarige Zellcluster und bleiben mit deren Somacortex über fibrilläre ‚cell streams‘ verbunden. Der weitere Zuwachs an Ganglionzellen und die exklusive Zellproliferation in den cluster-stream-Systemen weisen letztere als post-embryonale neurogenetische Nischen aus. Ähnlichkeiten zu der neurogenetischen Nische im Deutocerebrum der decapoden Krebse werden aufgezeigt.This study addresses aspects of the development of the sea spider Pseudopallene sp. (Arthropoda, Pycnogonida). In order to investigate morphogenesis and nervous system development, a combination of scanning electron microscopy, histology, immunohistochemistry and gene expression studies is used. Embryonic proboscis development shows no signs of a labrum. The lack of palpal and ovigeral limbs and the early anlagen of the walking leg segments lead to the rejection of an embryonized protonymphon stage during Pseudopallene development. The evolution of pycnogonid hatching stages is evaluated in light of recent phylogenetic analyses. Early neurogenesis shares similarities with euchelicerates and myriapods, including the lack of morphologically distinct neuroectodermal cell types, formation of transient cell internalization sites, immigration of mostly post-mitotic ganglion cells with elevated levels of Delta gene expression and predominantly tangentially oriented cell divisions in the neuroectoderm. Subsequently, paired invaginations form in each neuromere, being accompanied by marked enlargement of the apical cells. Due to their high mitotic activity, their asymmetric division mode and a marked cell number increase in the ganglia, the big cells are identified as stem cell-like neuronal precursors. Based on this, the validity of stem cell-like neuronal precursors as synapomorphy of crustaceans and hexapods is discussed. Two scenarios on the evolution of arthropod neurogenesis are presented. During the post-embryonic phase, the invaginating cell regions detach internally and form paired cell clusters at the apical ganglion sides. Each cluster remains connected to the ganglion soma cortex via fibrous cell streams. Increasing ganglion cell numbers and exclusive occurrence of mitoses within the cluster-stream-systems characterize the latter as post-embryonic neurogenic niches. Similarities to the neurogenic niche in the deutocerebrum of decapod crustaceans are discussed

Policy interventions, perceptions, and pro-environmental behavior for sustainable oil palm cultivation in Indonesia

In the last decades, oil palm cultivation has increased rapidly to meet the rising demands for vegetable oils worldwide. While in the 1970s, two million tons of palm oil on 3.3 million hectares of land were produced worldwide, production levels have increased by 36 times in 2019, to around 72.3 million tons on 28.3 million hectares of land. There are two main reasons for the rapid expansion. Oil palms can produce more tons per hectare compared to any other crop. In addition, it is very versatile in its use and can be used in the food industry, for cosmetics, industrial and agrochemical products, and biodiesel. Indonesia has been the biggest oil palm producer worldwide since 2008. The oil palm boom has brought economic benefits such as increases in incomes and living standards for the producers and others along the value chain. Besides the economic benefits that the oil palm industry has entailed, the massive land-use transformation and the common management practices applied have led to immense environmental degradation that affects the local population, rural and urban, but also beyond borders. Against this background, the focus of this dissertation is on the economic and environmental trade-offs of oil palm cultivation. The dissertation also addresses the environmental dimension of oil palm cultivation by examining climate change perceptions, environmental concern, and pro-environmental behavior among the local population. The present dissertation comprises three essays and addresses three broad research objectives: First, to assess the adoption decisions of an agricultural technology that generates positive environmental effects among small-scale oil palm farmers to support sustainable oil palm cultivation; second, to examine the environmental concern and pro-environmental behavior among the local population in a setting characterized by a rapid land-use transformation in the Global South; and third, to understand climate change perceptions among small-scale oil palm farmers in a setting of rapid land-use change. The analysis of the three essays relies on primary data collection in Jambi, Sumatra, Indonesia, from 2019 and 2020 and consists of a total of 757 respondents, where 408 are oil palm farmers and 349 are respondents from Jambi City. This research was conducted in the frame of the Collaborative Research Center (CRC) 990: Ecological and Socioeconomic Functions of Tropical Lowland Rainforest Transformation System (EFForTS) in Indonesia. The first essay focuses on the adoption of an agricultural technology that is socially desirable and generates positive environmental effects with delayed private benefits for the adopters. In the case of welfare-enhancing technologies such as improved seeds or fertilizer, scholars have shown that subsidies can be an adequate instrument to motivate adoption. Yet, for agricultural technologies such as native tree planting, that are socially desirable and need maintenance evidence remains limited on how to stimulate adoption, tree survival, and additional investments into this technology effectively. We implemented two policy interventions with oil palm smallholders to analyze the adoption of native tree planting, tree survival, and engagement in additional planting efforts. In the first treatment, oil palm farmers received information with regards to native tree planting and three native tree seedlings for free (subsidy treatment). In the second treatment, oil palm farmers received the same information about native tree planting and had then the opportunity to buy three native tree seedlings through an auction mechanism (price treatment). Our results show that under a subsidy scheme, farmers have a higher probability to plant the tree seedlings they received and they also plant more tree seedlings compared to the treatment where farmers had the opportunity to buy the seedlings. The higher planting intensity in the subsidy treatment led to a higher tree survival rate. Yet, we find a tendency towards more additional planting efforts in the price treatment pointing towards crowding-out effects of farmers in the subsidy treatment. The cost-effectiveness analysis that we conducted, reflects our results when focussing only on the trees that we provided. More tree seedlings were planted in the subsidy treatment which was also more expensive compared to the price treatment. The cost-effectiveness is higher for the price treatment when including additional planting efforts. This is driven by few farmers though. The second essay addresses environmental concern and pro-environmental behavior among the local population living in an oil palm cultivating hotspot in the Global South. Scholars have shown that negative environmental repercussions have an effect on environmental concern and the engagement in pro-environmental behavior of individuals. Environmental concern and pro-environmental behavior both indirectly or directly influence decisions made about the sustainable use of natural resources. For policymakers, it is highly relevant to understand how the local population thinks and behaves to develop more targeted policy and outreach instruments to support sustainable land-use changes. While there exists literature on environmental concern and pro-environmental behavior in industrialized nations focusing on rural-urban differences, evidence is scarce for societies in the Global South. In this study, we examine environmental concern and pro-environmental behavior in the Global South where people live in an oil palm cultivating hotspot and in a setting characterized by a rapid land-use transformation. Our results reveal that overall rural residents are significantly more concerned than urban respondents. This is true for general environmental concern, as well as for the specific oil palm concern which shows that oil palm farmers might be aware of the environmental effects of oil palm cultivation. We also find that connectedness with nature, connectedness with oil palms, and the preference for more heterogeneous landscapes are important determinants for environmental concern. For pro-environmental behavior, we find that rural respondents engage more. A higher connectedness with oil palms decreased the engagement in pro-environmental behavior among the respondents while the hours participated in other environmental activities are positively correlated with pro-environmental behavior. The third essay of this dissertation analyzes climate change perceptions of Indonesian small-scale oil palm farmers. The implications that climate change has on agriculture and vice versa are already visible today. On the one hand, the number and severity of climate change-related weather events have increased. On the other hand, agriculture contributes to climate change with the release of huge amounts of CO2. Much of the global warming that is experienced today and for the next 30 years is based on emissions that have already been released into the atmosphere. Yet, the degree of future global warming highly depends on emissions of today and the near future. Hence, adaptation strategies have to become a central strategy today to slow down and decrease the implications of climate change and agriculture on each other in the long term. To do so, climate change perceptions of individuals need to be well understood to develop suitable strategies. In this regard, scholars have shown that farmers seem to be aware of climate change and its potential effects to varying degrees. Important sociodemographic factors that are associated with climate change perceptions are education, age, and wealth amongst others. Yet, evidence remains limited for climate change awareness and the perceived affectedness of small-scale oil palm farmers living in a setting of rapid land-use transformation. In this study, we analyze determinants of climate change awareness and perceived affectedness of small-scale oil palm farmers. Our results reveal that about three-quarters of the respondents are aware of climate change and almost 60 percent feel personally affected by it. Important factors associated with climate change awareness and perceived affectedness are education, age, and wealth. Finally, the experience of extreme weather events seems to not strongly be associated with the climate change perceptions of the oil palm farmers. This dissertation contributes to the actual state of research with regards to the economic and environmental trade-offs of oil palm cultivation as well as to the environmental dimension by examining climate change perceptions, environmental concern, and pro-environmental behavior among the local population. The results indicate firstly, that the adoption of native tree planting can be enhanced by a policy mix that involves the distribution of subsidized tree seedlings as well as value chain development to address multiple barriers to native tree seedlings. Secondly, environmental concern and pro-environmental behavior differ significantly between rural and urban residents, and hence, to overcome a lack of disconnectedness between the general public and the agrarian transformation and strengthen environmental concern and pro-environmental behavior, the spread of information and environmental education seem to be promising. Finally, to support the development of suitable climate change adaptation strategies relevant knowledge needs to be spread among the farmers to create more climate change awareness. Furthermore, as the financial means of the farmers differ but are associated with being better equipped regarding adaptation measures, especially, the poorer farmers need to receive suitable support when it comes to the adoption of adaptation measures taking potential barriers, e.g. financial means, into account.2021-12-0

Long Range Optical Distance Sensors for Liquid Metal Free Surface Detection

For the demonstration of fusion power plant technology, DEMO dedicated materials are necessary to cope with the harsh environment of high energy neutrons. For this purpose, the international neutron irradiation facility for fusion materials IFMIF/DEMO Oriented Neutron Source (DONES) is planned to be built in Granda, Spain. In the DONES facility, a deuteron beam hitting the lithium target produces a high energy neutron flux. Due to the high-power density, the windowless target is a free surface liquid lithium flow in a duct with a concave backplate. In order to keep the heat released by the beam within the liquid lithium and to avoid its intrusion in the backplate, a stable configuration of the free surface flow with a setpoint layer thickness of 25 ± 1 mm is crucial. In particular, stable wave structures, so called wakes, which occur from accumulated impurities at the nozzle edge, can cause a critical local decrease in the layer thickness of more than 1 mm. Therefore, it is necessary to better understand the nature of these wakes and to be able to monitor the surface profile to shut down the beam in case of a critical thickness loss, but to avoid unintended shutdowns. In the context of this work, currently available optical sensors were tested on their capability of detecting a specular liquid metal surface at measurement distances of several meters. After an initial selection, two optical sensors were further considered. Experiments with the liquid metal alloy GaInSn and simulations with the software Blender of the selected optical sensors for their capability of measuring distances of liquid metal were conducted. The results showed a significant dependency of the measurement results on the waviness of the liquid metal surface. Nevertheless, it was possible to resolve the wavy liquid metal surface with a sufficient resolution to detect critical wake structures

Alien Registration- Brenneis, Anna K. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/30651/thumbnail.jp

A postlarval instar of Phoxichilidium femoratum (Pycnogonida, Phoxichilidiidae) with an exceptional malformation

Individuals of the marine chelicerate lineage Pycnogonida (sea spiders) show considerable regenerative capabilities after appendage injury or loss. In their natural habitats, especially the long legs of sea spiders are commonly lost and regenerated, as is evidenced by the frequent encounter of specimens with missing or miniature legs. In contrast to this, the collection of individuals with abnormally developed appendages or trunk regions is comparably rare. Here, we studied a remarkable malformation in a postlarval instar of the species Phoxichilidium femoratum (Rathke, 1799) and describe the external morphology and internal organization of the specimen using a combination of fluorescent histochemistry and scanning electron microscopy. The individual completely lacks the last trunk segment with leg pair 4 and the normally penultimate trunk segment bears only a single aberrant appendage resembling an extension of the anteroposterior body axis. Externally, the proximal units of the articulated appendage are unpaired, but further distally a bifurcation into two equally developed leg‐like branches is found. Three‐dimensional reconstruction of the musculature reveals components of two regular leg muscle sets in several of the proximal articles. This confirms interpretation of the entire appendage as a malformed leg and reveals an externally hidden paired organization along its entire proximodistal axis. To explain the origin of this unique malformation, early pioneering studies on the regenerative potential of pycnogonids are evaluated and (a) an injury‐induced partial fusion of the developing limb buds of leg pair 3, as well as (b) irregular leg regeneration following near complete loss of trunk segments 3 and 4 are discussed. Which of the two hypotheses is more realistic remains to be tested by dedicated experimental approaches. These will have to rely on pycnogonid species with established laboratory husbandry in order to overcome the limitations of the few short‐term regeneration studies performed to date.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659National Science Foundation http://dx.doi.org/10.13039/100000001Peer Reviewe

On culture artefacts in coccolith morphology

Coccolith malformations occur more frequently in cultured specimens than in specimens from natural samples, a phenomenon commonly termed ‘culture artefacts’. The causes of culture artefacts are unknown. Here, we tested the effect of culture flask shape, mixing, and cell density on the morphology of Emiliania huxleyi coccoliths. While there was no effect of different culture flask types typically used in coccolithophore culturing, continuous mixing reduced the percentage of malformations by ca. 11 % in exponential-phase cells (cell density ca. 80 × 103 cells per ml) and ca. 17 % in stationary-phase cells (cell density ca. 2 × 106 cells per ml). Stationary-phase cells displayed 19 % more malformations than mid-exponential-phase cells when not mixed at all and 20 % more malformations when continuously mixed. It is concluded that the lack of mixing and unnaturally high cell densities, typical for coccolithophore stock cultures, are partly responsible for culture artefacts

Episodic Hyponatremia is Associated with Increased Mortality in Hemodialysis Patients

Introduction: Hyponatremia is common in many patient populations and has been linked to increased mortality. Hyponatremia in hemodialysis (HD) patients is also common, yet, only cross-sectional analyses are available. The hypothesis of the current study was that not only persistent, but also episodic hyponatremia in HD patients is associated with increased mortality. Methods: The prevalence of persistent and episodic (short duration (<3 months), high frequency (>=8 episodes) and long duration (>3 months), low (1-3 episodes) and medium (4-7 episodes) frequency) patterns of hyponatremia (plasma Na < 135 mmol/L) was investigated in 2473 patients on in-center HD, using plasma Na levels determined monthly over a median of 4.6 years. Both persistent and episodic hyponatremia are linked to mortality. Results: Normal sodium over the entire observations period was observed in 34% of patients, episodic short duration, high frequency in 9% of patients and long duration, low and medium frequency in 8% of patients. Both persistent hyponatremia and long duration, low/medium frequency were associated with decrease survival compared to patients without hyponatremia. Conclusion: Our results suggest that episodic hyponatremia may be just as an important predictor of mortality as stable hyponatremia.  This result further implies that a cross sectional analysis of hyponatremic patients undergoing hemodialysis may underestimate the risk associated with hyponatremia due to the potential for its episodic nature. *Indicates faculty mento

Antinociceptive activity of the S1P-receptor agonist FTY720

FTY720 is a novel immunosuppressive drug that inhibits the egress of lymphocytes from secondary lymphoid tissues and thymus. In its phosphorylated form FTY720 is a potent S1P receptor agonist. Recently it was also shown that FTY720 can reduce prostaglandin synthesis through the direct inhibition of the cytosolic phospholipase A2 (cPLA2). Since prostaglandins are important mediators of nociception, we studied the effects of FTY720 in different models of nociception. We found that intraperitoneal administration of FTY720 reduced dose-dependently the nociceptive behaviour of rats in the formalin assay. Although the antinociceptive doses of FTY720 were too low to alter the lymphocyte count, prostanoid concentrations in the plasma were dramatically reduced. Surprisingly, intrathecally administered FTY720 reduced the nociceptive behaviour in the formalin assay without altering spinal prostaglandin synthesis, indicating that additional antinociceptive mechanisms beside the inhibition of prostaglandin synthesis are involved. Accordingly, FTY720 reduced also the nociceptive behaviour in the spared nerve injury model for neuropathic pain which does not depend on prostaglandin synthesis. In this model the antinociceptive effect of FTY720 was similar to gabapentin, a commonly used drug to treat neuropathic pain. Taken together we show for the first time that FTY720 possesses antinociceptive properties and that FTY720 reduces nociceptive behaviour during neuropathic pain