Multi-Tone Microwave Locking via Real-Time Feedback

Environmental noise coupling to mechanical experiments often introduces low-frequency fluctuations to the resonators, adding noise to measurements and reducing signal to noise. To counter these fluctuations, we demonstrate a dynamic feedback system implemented by the locking of a microwave drive to the noisy cavity. A homodyne interferometer scheme monitors the cavity resonance fluctuations due to low-frequency noise, which is mitigated by frequency-modulating (FM) the microwave generator. The feedback has a bandwidth of $400$ Hz, with a reduction of cavity fluctuations by $84\%$ integrating up to a bandwidth of $2$ kHz. Moreover, the cavity resonance frequency fluctuations are reduced by $73\%$. This scheme can be scaled to enable multi-tone experiments locked to the same feedback signal. As a demonstration, we apply the feedback to an optomechanical experiment and implement a cavity-locked, multi-tone mechanical measurement. As low-frequency cavity frequency noise can be a limiting factor in many experiments, the multi-tone microwave locking technique presented here is expected to be relevant for a wide range of fields of research.Comment: 7 pages, 5 figure

A method for the deliberate and deliberative selection of policy instrument mixes for climate change adaptation

Policy instruments can help put climate adaptation plans into action. Here, we propose a method for the systematic assessment and selection of policy instruments for stimulating adaptation action. The multi-disciplinary set of six assessment criteria is derived from economics, policy, and legal studies. These criteria are specified for the purpose of climate adaptation by taking into account four challenges to the governance of climate adaptation: uncertainty, spatial diversity, controversy, and social complexity. The six criteria and four challenges are integrated into a step-wise method that enables the selection of instruments starting from a generic assessment and ending with a specific assessment of policy instrument mixes for the stimulation of a specific adaptation measure. We then apply the method to three examples of adaptation measures. The method’s merits lie in enabling deliberate choices through a holistic and comprehensive set of adaptation specific criteria, as well as deliberative choices by offering a stepwise method that structures an informed dialog on instrument selection. Although the method was created and applied by scientific experts, policy-makers can also use the method

Violent conflict and behavior:A field experiment in Burundi

We use a series of field experiments in rural Burundi to examine the impact of exposure to conflict on social, risk, and time preferences. We find that conflict affects behavior: individuals exposed to violence display more altruistic behavior towards their neighbors, are more risk-seeking, and have higher discount rates. Large adverse shocks can thus alter savings and investments decisions, and potentially have long-run consequences—even if the shocks themselves are temporary

Comparison of static immersion and intravenous injection systems for exposure of zebrafish embryos to the natural pathogen Edwardsiella tarda

<p>Abstract</p> <p>Background</p> <p>The zebrafish embryo is an important <it>in vivo </it>model to study the host innate immune response towards microbial infection. In most zebrafish infectious disease models, infection is achieved by micro-injection of bacteria into the embryo. Alternatively, <it>Edwardsiella tarda</it>, a natural fish pathogen, has been used to treat embryos by static immersion. In this study we used transcriptome profiling and quantitative RT-PCR to analyze the immune response induced by <it>E. tarda </it>immersion and injection.</p> <p>Results</p> <p>Mortality rates after static immersion of embryos in <it>E. tarda </it>suspension varied between 25-75%, while intravenous injection of bacteria resulted in 100% mortality. Quantitative RT-PCR analysis on the level of single embryos showed that expression of the proinflammatory marker genes <it>il1b </it>and <it>mmp9 </it>was induced only in some embryos that were exposed to <it>E. tarda </it>in the immersion system, whereas intravenous injection of <it>E. tarda </it>led to <it>il1b </it>and <it>mmp9 </it>induction in all embryos. In addition, microarray expression profiles of embryos subjected to immersion or injection showed little overlap. <it>E. tarda</it>-injected embryos displayed strong induction of inflammatory and defense genes and of regulatory genes of the immune response. <it>E. tarda</it>-immersed embryos showed transient induction of the cytochrome P450 gene <it>cyp1a</it>. This gene was also induced after immersion in <it>Escherichia coli </it>and <it>Pseudomonas aeruginosa </it>suspensions, but, in contrast, was not induced upon intravenous <it>E. tarda </it>injection. One of the rare common responses in the immersion and injection systems was induction of <it>irg1l</it>, a homolog of a murine immunoresponsive gene of unknown function.</p> <p>Conclusions</p> <p>Based on the differences in mortality rates between experiments and gene expression profiles of individual embryos we conclude that zebrafish embryos cannot be reproducibly infected by exposure to <it>E. tarda </it>in the immersion system. Induction of <it>il1b </it>and <it>mmp9 </it>was consistently observed in embryos that had been systemically infected by intravenous injection, while the early transcriptional induction of <it>cyp1a </it>and <it>irg1l </it>in the immersion system may reflect an epithelial or other tissue response towards cell membrane or other molecules that are shed or released by bacteria. Our microarray expression data provide a useful reference for future analysis of signal transduction pathways underlying the systemic innate immune response versus those underlying responses to external bacteria and secreted virulence factors and toxins.</p

Nutritive value of palm kernel meal in diets for growing rabbits

The aim of this work was to determine the nutritive value of palm kernel meal (PKM) in diets for growing rabbits. In Experiment 1, 20 New Zealand × Californian growing rabbits 50 d-old were used to determine energy, crude protein, fibre and fat digestibility of PKM. The nutritive value was estimated by the difference method using a basal diet and another diet made by substituting 200 g/kg of basal diet with PKM. Energy, crude protein, ether extract and neutral detergent fibre of PKM digestibilities were, respectively, 0.549 (±0.056, SE), 0.541 (±0.069), 0.850 (±0.048) and 0.430 (±0.101), and the digestible energy concentration was 10.9 MJ/kg (±1.03) DM. In Experiment 2, 412 rabbits were allocated at random to the two experimental diets to measure growing performance. Inclusion of 200 g PKM/kg in the diet did not affect feed or digestible energy intake but decreased slightly (by around 5%) average daily gain (P = 0.003) and feed efficiency (P < 0.001). Neither mortality nor Clostridium perfringens counts in soft faeces were affected by type of diet. Palm kernel meal can be considered a palatable source of fibre, protein and fat for rabbits and can substitute significant amounts of other fibrous ingredients in the diet without adverse effects on growth performance

Enhancing the bioconversion of winery and olive mill waste mixtures into lignocellulolytic enzymes and animal feed by Aspergillus uvarum using a packed-bed bioreactor

Wineries and olive oil industries are dominant agro-industrial activities in southern European regions. Olive pomace, exhausted grape marc and vine shoot trimmings are lignocellulosic residues generated by these industries, which could be valued biotechnologically. In the present work these residues were used as substrate to produce cellulases and xylanases through solid-state fermentation using Aspergillus uvarum. For that, two factorial designs (32) were first planned to optimize substrate composition, temperature and initial moisture level. Subsequently, the kinectics of cellulolytic enzymes production, fungal growth and fermented solid were characterized, Finally, the process was performed in a packed-bed bioreactor. The results showed that cellulase activity improved with the optimization processes, reaching 33.56 U/g, and with the packed-bed bioreactor aeration of 0.2 L/min, reaching 38.51 U/g. The composition of fermented solids indicated their potential use for animal feed because cellulose, hemicellulose, lignin and phenolic compounds were partially degraded 28.08, 10.78, 13.3 and 28.32% respectively, crude protein was increased from 8.47% to 17.08%, and, the mineral contents meet the requirements of main livestock.J.M.S. was supported by Grant SFRH/BPD/84440/2012 from Fundacao para a Ciencia e Tecnologia (FCT), Portugal. L.A. was supported by Grant Incentivo/EQB/LA0023/2014 from O Novo Norte (ON.2). We thank FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the Project "BioInd - Biotechnology and Bioengineering for improved Industrial and Agro-Food processes, Rer. NORTE-07-0124-FEDER-000028" co-funded by the Programa Operacional Regional do Norte (ON.2), QREN, FEDE

Combined optical coherence tomography and intravascular ultrasound radio frequency data analysis for plaque characterization. Classification accuracy of human coronary plaques in vitro

This study was performed to characterize coronary plaque types by optical coherence tomography (OCT) and intravascular ultrasound (IVUS) radiofrequency (RF) data analysis, and to investigate the possibility of error reduction by combining these techniques. Intracoronary imaging methods have greatly enhanced the diagnostic capabilities for the detection of high-risk atherosclerotic plaques. IVUS RF data analysis and OCT are two techniques focusing on plaque morphology and composition. Regions of interest were selected and imaged with OCT and IVUS in 50 sections, from 14 human coronary arteries, sectioned post-mortem from 14 hearts of patients dying of non-cardiovascular causes. Plaques were classified based on IVUS RF data analysis (VH-IVUSTM), OCT and the combination of those. Histology was the benchmark. Imaging with both modalities and coregistered histology was successful in 36 sections. OCT correctly classified 24; VH-IVUS 25, and VH-IVUS/OCT combined, 27 out of 36 cross-sections. Systematic misclassifications in OCT were intimal thickening classified as fibroatheroma in 8 cross-sections. Misclassifications in VH-IVUS were mainly fibroatheroma as intimal thickening in 5 cross-sections. Typical image artifacts were found to affect the interpretation of OCT data, misclassifying intimal thickening as fibroatheroma or thin-cap fibroatheroma. Adding VH-IVUS to OCT reduced the error rate in this study

Low cost feeding strategies for dual purpose cattle in Venezuela

This simulation study was to evaluate low cost feeding strategies in response to higher cost of commercial concentrates to maintain current milk sales from dual purpose cattle herds in the humid lowlands of western Venezuela. Data were from farm surveys in 1987 and 1988. Baseline net margins from milk and beef per cow per year were $132 and$99 for two farm cases with average dally milk of 10 and 7 kg/cow and grazing mature forage supplemented with commercial concentrate. Alternative diets were 1) improving forage quality by more intensive grazing; 2) replacing commercial concentrate with a mixture of cassava tuber (Manihot esculenta), urea, and molasses and 3) supplementing grazing with a mixture of molasses and urea. Alternatively priced feeding strategies were compared by partial budgeting. Using less mature forage was .always more profitable than mature grass. Feeding molasses and urea with mature forage increased profits at least $64/cow on the high milk yield farm and$44/cow on the low milk yield farm compared with feeding commercial concentrate. The most costly cassava mixture with mature forage increased annual profit over the baseline diet at least $11/ cow on the high milk yield farm and by$22/cow on the low yield farm. Efficient use of existing feed resources may enhance economical livestock production in the humid lowlands of Venezuela