Climate Resilient Development and Discourse in the Peruvian Highlands

This dissertation strives to rethink apolitical and ahistorical efforts for adapting to climate change in terms of a political struggle for survival in times of radical global environmental change. Drawing on ethnographic and participatory fieldwork with agro-pastoralists of the Peruvian Andes, government officials and international NGO actors, this dissertation follows emergent climate-resilient discourse of rapid glacier retreat as it travels from global origins and articulates with local culture and indigenous ecologies in the Cordillera Blanca. Through this research, I offer a critical interpretive analysis of modern, capitalist and rationalist ways of knowing and planning for climate change, finding that such adaptation efforts in the Andes constitutes hegemonic, discursive practices that reproduce uneven geographies of power and subalternize “other” ways of knowing about, and responding to, climate change. This research probes questions of power and equity in multi-scalar adaptation efforts across four axes: indigenous representations, environmental narratives, adaptation imaginaries and collaborative governance. Across the resultant dissertation chapters I argue that a certain type of power, the ‘coloniality of power’ (Quijano, 2000), emerges as a recurrent motif in adaptation practices in the so-called “Third-World”. As modern politics for climate change prove to be hostile spaces for indigenous peoples and subaltern knowledges, this research attempts to understand and map out a plurality of adaptation imaginaries from the local to the global, illuminating their synergies and honoring their incommensurability. After providing a critical reflexive review of collaborative adaptation efforts in post-colonial ecologies, I call for adaptation otherwise as an advance of counter-hegemonic and decolonial adaptation projects. Three relational lessons for adaptation otherwise that are drawn from the participatory and collaborative engagements undertaken in this research are suggested for decolonizing the development-adaptation enterprise, including: i) a recognition and defense of difference, ii) learning to learn from below, and iii) bridging

Interaction between current imbalance and magnetization in LHC cables

The quality of the magnetic field in superconducting accelerator magnets is associated with the properties of the superconducting cable. Current imbalances due to coupling currents ¿I, as large as 100 A, are induced by spatial variations of the field sweep rate and contact resistances. During injection at a constant field all magnetic field components show a decay behavior. The decay is caused by a diffusion of coupling currents into the whole magnet. This results in a redistribution of the transport current among the strands and causes a demagnetization of the superconducting cable. As soon as the field is ramped up again after the end of injection, the magnetization rapidly recovers from the decay and follows the course of the original hysteresis curve. In order to clarify the interactions between the changes in current and magnetization during injection the authors performed a number of experiments. A magnetic field with a spatially periodic pattern was applied to a superconducting wire in order to simulate the coupling behavior in a magnet. This model system was placed into a stand for magnetization measurements and the influence of different powering conditions was analyze

Stretching single polysaccharide molecules using AFM: A potential method for the investigation of the intermolecular uronate distribution of alginate?

Illustrative examples of the way in which the molecular force-extension behaviour of polysaccharides is governed by the nature of the linkage between their constituent pyranose rings are presented for a series of standard homopolymers. These results agree with previously proposed general hypotheses regarding the possibility of generating force-induced conformational transitions, and with the predictions of a model in which the inter-conversion of pyranose conformers is assumed to be an equilibrium process on the timescale of the molecular stretching. Subsequently, we investigate the potential of the technique in the characterisation of co-polymeric polysaccharides in which the nature of the glycan linkages is different between the two distinct residue types. Specifically, we explore the possibility that the ratio of mannuronic acid (M) to guluronic acid (G) in alginate chains will be reflected in their single molecule stretching behaviour, owing to their contrasting equatorial and axial linkages. Furthermore, as the technique described interrogates the sample one polymer at a time we outline the promise of, and the obstacles to, obtaining a new level of characterisation using this methodology where differences observed in the single molecule stretching curves obtained from single alginate samples reflectsomething of the real intermolecular distribution of the M / G ratio

Photovoltaic cells energy performance enhancement with down-converting photoluminescence phosphors

Phosphors, synthesized by the urea homo-precipitation method, were examined as ultraviolet-spectral down conversion materials for improving the light absorption and electrical characteristics of commercial single-junction silicon solar cells. The photovoltaic (PV) cells were coated with erbium and terbium doped gadolinium oxysulfide phosphors encapsulated in ethyl vinyl-acetate binder using blade screen printing technique, and the optimum concentration of phosphor in the composite resulted in the largest light conversion, and superior electrical output and energy transfer efficiency. Moreover, the results demonstrated that the composition of dispersed phosphors has a strong influence on the amount of ultraviolet-light converted and electron transition capacity of PV cells. The experimental results showed in an optimized PV cell, an enhancement of 0.54% (from 12.11% to 12.65%) in the energy conversion of a Si-based PV cell was achieved.Mr. Ben Parker of LOT-QuantumDesig

Electrocardiographic assessments and cardiac events after fingolimod first dose – a comprehensive monitoring study

Background First dose observation for cardiac effects is required for fingolimod, but recommendations on the extent vary. This study aims to assess cardiac safety of fingolimod first dose. Individual bradyarrhythmic episodes were evaluated to assess the relevance of continuous electrocardiogram (ECG) monitoring. Methods START is an ongoing open-label, multi-center study. At the time of analysis 3951 patients were enrolled. The primary endpoints are the incidence of bradycardia (heart rate < 45 bpm) and second-/third-degree AV blocks during treatment initiation. The relevance of Holter was assessed by matching ECG findings with the occurrence of clinical symptoms as well as by rigorous analysis of AV blocks with regard to the duration of pauses and the minimal heart rate recorded during AV block. Results Thirty-one patients (0.8%) developed bradycardia (<45 bpm), 62 patients (1.6%) had second-degree Mobitz I and/or 2:1 AV blocks with a lowest reading (i.e. mean of ten consecutive beats) of 35 bpm and the longest pause lasting for 2.6 s. No Mobitz II or third-degree AV blocks were observed. Only one patient complained about mild chest discomfort and fatigue. After 1 week, there was no second -/third-degree AV block. Conclusions Continuous Holter ECG monitoring in this large real-life cohort revealed that bradycardia and AV conduction abnormalities were rare, transient and benign. No further unexpected abnormalities were detected. The data presented here give an indication that continuous Holter ECG monitoring does not add clinically relevant value to patients’ safety. Trial registration NCT01585298; registered April 23, 2012

Degaussing and Decay Reduction in the Short Superconducting Dipole Models for the LHC

The time decay of field harmonics during current plateaus is a known drawback of superconducting accelerator magnets. The present understanding of this phenomenon refers to a combination of flux creep and of the interaction between the redistribution of currents in Rutherford cables and the filament magnetization. Current cycles of decreasing amplitude, called here degaussing, were found to reduce significantly the decay observed in accelerator magnets. This paper reports on the measured reduction of decay obtained in short dipole models for the LHC and on one experiment with a single LHC strand

Plasmonic gold helices for the visible range fabricated by oxygen plasma purification of electron beam induced deposits

Electron beam induced deposition (EBID) currently provides the only direct writing technique for truly three-dimensional nanostructures with geometrical features below 50 nm. Unfortunately, the depositions from metal-organic precursors suffer from a substantial carbon content. This hinders many applications, especially in plasmonics where the metallic nature of the geometric surfaces is mandatory. To overcome this problem a post-deposition treatment with oxygen plasma at room temperature was investigated for the purification of gold containing EBID structures. Upon plasma treatment, the structures experience a shrinkage in diameter of about 18 nm but entirely keep their initial shape. The proposed purification step results in a core-shell structure with the core consisting of mainly unaffected EBID material and a gold shell of about 20 nm in thickness. These purified structures are plasmonically active in the visible wavelength range as shown by dark field optical microscopy on helical nanostructures. Most notably, electromagnetic modeling of the corresponding scattering spectra verified that the thickness and quality of the resulting gold shell ensures an optical response equal to that of pure gold nanostructures

Cover Article Research Articles, Systems/Circuits

Double cones are the most common photoreceptor cell type in most avian retinas, but their precise functions remain a mystery. Among their suggested functions are luminance detection, polarized light detection, and light-dependent, radical-pair-based magnetoreception. To better understand the function of double cones, it will be crucial to know how they are connected to the neural network in the avian retina. Here we use serial sectioning, multi-beam scanning electron microscopy (ssmSEM) to investigate double cone anatomy and connectivity with a particular focus on their contacts to other photoreceptor and bipolar cells in the chicken retina. We found that double cones are highly connected with neighbouring double cones and with other photoreceptor cells through telodendria-to-terminal and telodendria-to-telodendria contacts. We also identified 15 bipolar cell types based on their axonal stratifications, photoreceptor contact pattern, soma position, and dendritic and axonal field mosaics. Thirteen of these 15 bipolar cell types contacted at least one or both members of the double cone. All bipolar cells were bi- or multistratified. We also identified surprising contacts between other cone types and between rods and cones. Our data indicate a much more complex connectivity network in the outer plexiform layer of the avian retina than originally expected

Variation in Manduca sexta pollination-related floral traits and reproduction in a wild tobacco plant

Most flowering plants depend on animal pollination for successful sexual reproduction. Floral signals such as color, shape, and odor are crucial in establishing this (often mutualistic) interaction. Plant and pollinator phenotypes can vary temporally but also spatially, thus creating mosaic-like patterns of local adaptations. Here, we investigated natural variation in floral morphology, flower volatile emission, and phenology in four accessions of a self-compatible wild tobacco, Nicotiana attenuata, to assess how these traits match the sensory perception of a known pollinator, the hawkmoth Manduca sexta. These accessions differ in floral traits and also in their habitat altitudes. Based on habitat temperatures, the accession occurring at the highest altitude (California) is less likely to be visited by M. sexta, while the others (Arizona, Utah 1, and Utah 2) are known to receive M. sexta pollinations. The accessions varied significantly in flower morphologies, volatile emissions, flower opening, and phenology, traits likely important for M. sexta perception and floral handling. In wind tunnel assays, we assessed the seed set of emasculated flowers after M. sexta visitation and of natural selfed and hand-pollinated selfed flowers. After moth visitations, plants of two accessions (Arizona and Utah 2) produced more capsules than the other two, consistent with predictions that accessions co-occurring with M. sexta would benefit more from the pollination services of this moth. We quantified flower and capsule production in four accessions in a glasshouse assay without pollinators to assess the potential for self-pollination. The two Utah accessions set significantly more seeds after pollen supplementation compared with those of autonomous selfing flowers, suggesting a greater opportunistic benefit from efficient pollinators than the other two. Moreover, emasculated flowers of the accession with the most exposed stigma (Utah 2) produced the greatest seed set after M. sexta visitation. This study reveals intraspecific variation in pollination syndromes that illuminate the potential of a plant species to adapt to local pollinator communities, changing environments, and altered pollination networks

Relative timing jitter measurements with an indirect phase comparison method

We propose and demonstrate experimentally a method for the sensitive measurement of the relative timing jitter of two mode-locked lasers, which can be either free-running or timing-synchronized to a common reference oscillator. The method is based on the indirect comparison of the phases of two photodetector outputs, using a microwave oscillator, the noise of which does not affect the results, electronic mixers, and a sampling oscilloscope. We carefully analyze and experimentally demonstrate the potential of this method. Compared to phase detector methods, it has a broader scope of applications and a lower sensitivity to intensity noise. We also obtained data on the coupling of intensity to timing noise in photodetector