Katalysis: helping Andean farmers adapt to climate change

Recent studies of global climate change paint a bleak picture for the Andes. Researchers have proposed expert-led solutions, such as improved climatic modelling and forecasting, and the breeding of drought-tolerant crop varieties. In this article, the authors argue that farmers need to shape the research agenda according to local priorities, and that smallholders and researchers should learn together. The Katalysis approach to climate change adaptation is on enhancing local knowledge of climate change and creating opportunities for coping with it. Katalysis aims at helping rural people to creatively manage their own resources in response to the growing threat of climate change. Katalysis builds on Farmer Field Schools ‘discovery learning’ tradition and other flexible, knowledge based approaches for improving agriculture through farmer participation in group problem-solving. The approach requires strong facilitators with flexible programmes and funding to support open-ended learning-action. Donor and development agencies must hand over more trust and responsibility to communities to design and implement their own agendas. Local people and outsiders need to be free to learn from each other, and to learn as they go along

Increasing throughput in IEEE 802.11 by optimal selection of backoff parameters

Engineering and Physical Sciences Research Council. Grant Number: EP/G012628/

Condition monitoring and prognostic indicators for network reliability

Large-scale investment in transmission and distribution networks are planned over the next 10-15 years to meet future demand and changes in power generation. However, it is important that existing assets continue to operate reliably and their health maintained. A research project is considering the increased use of simulation models that could provide accurate prognostics, targeting maintenance and reduce in service failures. Such models could be further refined with parameters obtained from on-line measurements at the asset. It is also important to consider the future development of the research agenda for condition monitoring of power networks and with colleagues from National Grid, PPA Energy and the Universities of Manchester and Strathclyde, the research team are preparing a Position Paper on this subject

Modeling, analyzing and controlling hybrid systems by Guarded Flexible Nets

A number of artificial and natural systems can be modeled as hybrid models in which continuous and discrete variables interact. Such hybrid models are usually challenging to analyze and control due to the computational complexity associated with existing methods. In this paper, the novel modeling formalism of Guarded Flexible Nets (GFNs) is proposed for the modeling, analysis and control of hybrid system. A GFN consists of an event net that determines how the state changes as processes execute, and an intensity net that determines the speeds of the processes. In a GFN, the continuous state is given by the value of its state variables, and the discrete state is given by the region within which such variables lie. GFNs are shown to possess a high modeling power while offering appealing analysis and control possibilities

PHASIC MUSCLE ACTIVITY OF THE LOWER EXTREMITY AT DIFFERENT POWERS AND PEDALLING CADENCES IN CYCLE ERGOMETRY

Changes in muscle activity occur with changes in cycling cadence and power output. An understanding of these changes can aid in strength training and performance evaluation. Although the integrated EMG has been frequently studied, phasic muscle activity is evaluated less often. Phasic activity was measured relative to the crank position from 0º at top dead center (TDC) through a fill revolution. Four muscles on three experienced recreational cyclists were monitored at cadences of 60rpm, 80rpq and l00rpm and at power levels of 150W, 300W, and 450W. Surface electrodes and videography were utilized to determine the start and stop position of muscle activity relative to each crank revolution. A fill-rectification of the raw EMG signal was then used to determine activity above the threshold. Rectus femoris activity started earlier in the crank cycle with each increase in cadence. However, it stopped later for only the first increment in cadence and remained constant for the second. These changes increased the duration of muscle activity at the higher cadences. Power output had no effect on the duration of rectus femoris activity, however the activity did shift relative to the crank cycle. The vastus lateralis activity showed similar changes in duration. Relative to power output, the duration of vastus lateralis activity was higher at the highest power output. The gluteus maximus and biceps femoris were also considered, but were not analyzed. The EMG results of the gluteus maximus had a small magnitude that was obscured by noise. The start and stop points of the biceps femoris activity were obscured when the asymmetrical raw EMG pattern was My rectified. Further study of these muscles as well as larger sample size would enhance the knowledge for improved cycle training

Oblique triangular antiferromagnetic phase in CsCu1−x_{1-x}Cox_xCl3_3

The spin-1/2 stacked triangular antiferromagnet CsCu$_{1-x}$Co$_x$Cl$_3$ with $0.015<x<0.032$ undergoes two phase transitions at zero field. The low-temperature phase is produced by the small amount of Co$^{2+}$ doping. In order to investigate the magnetic structures of the two ordered phases, the neutron elastic scattering experiments have been carried out for the sample with $x\approx 0.03$. It is found that the intermediate phase is identical to the ordered phase of CsCuCl$_3$, and that the low-temperature phase is an oblique triangular antiferromagnetic phase in which the spins form a triangular structure in a plane tilted from the basal plane. The tilting angle which is 42$^{\circ}$ at $T=1.6$ K decreases with increasing temperature, and becomes zero at $T_{\rm N2} =7.2$ K. An off-diagonal exchange term is proposed as the origin of the oblique phase.Comment: 6 pages, 7 figure

Magnetotransport with two occupied subbands in a Si(100) inversion layer

We have studied an electron transport in inversion layers of high-mobility Si(100) samples. At high electron concentrations and temperatures below 4.2 K, two series of Shubnikov-de Haas oscillations have been observed. The temperature damping of the second series oscillations indicates that the second occupied subband belongs to the first energy level of the fourfold-degenerate ladder $0'$. Samples with two occupied subbans exhibit a strong anomalous negative magnetoresitance, reaching $\rm \approx 25 \%$ of a zero field value at $B =$ 12 T. The resistance decrease is more pronounced for lower temperatures and higher electron concentrations. We explain this behaviour by an increase of the second subband mobility due to the freezing-out of the scattering of $0'$ electrons. Based on the measured periods of SdH oscillations, we conclude that the electrons are distributed inhomogeneously beneath the sample gate.Comment: 4 pages. RevTex text and 4 PostScript figures in a single tar-compressed file produced by 'uufiles

Laser augmented by brachytherapy versus laser alone in the palliation of adenocarcinoma of the oesophagus and cardia: a randomised study

Background: Many patients with advanced malignant dysphagia are not suitable for definitive treatment. The best option for palliation of dysphagia varies between patients. This paper looks at a simple technique for enhancing laser recanalisation. Aim: To assess the value of adjunctive brachytherapy in prolonging palliation of malignant dysphagia by endoscopic laser therapy. Patients: Twenty two patients with advanced malignant dysphagia due to adenocarcinoma of the oesophagus or gastric cardia, unsuitable for surgery or radical chemoradiotherapy. Methods: Patients able to eat a soft diet after laser recanalisation were randomised to no further therapy or a single treatment with brachytherapy (10 Gy). Results were judged on the quality and duration of dysphagia palliation, need for subsequent intervention, complications, and survival. Results: The median dysphagia score for all patients two weeks after initial treatment was 1 (some solids). The median dysphagia palliated interval from the end of initial treatment to recurrent dysphagia or death increased from five weeks (control group) to 19 weeks (brachytherapy group). Three patients had some odynophagia for up to six weeks after brachytherapy. There was no other treatment related morbidity or mortality. Further intervention was required in 10 of 11 control patients (median five further procedures) compared with 7/11 brachytherapy patients (median two further procedures). There was no difference in survival (median 20 weeks (control), 26 weeks (brachytherapy)). Conclusions: Laser therapy followed by brachytherapy is a safe, straightforward, and effective option for palliating advanced malignant dysphagia, which is complementary to stent insertion

Downregulation of Fzd6 and Cthrc1 and upregulation of olfactory receptors and protocadherins by dietary beta-carotene in lungs of Bcmo1-/- mice.

An ongoing controversy exists on beneficial versus harmful effects of high beta-carotene (BC) intake, especially for the lung. To elucidate potential mechanisms, we studied effects of BC on lung gene expression. We used a beta-carotene 15,15'-monooxygenase 1 (Bcmo1) knockout mouse (Bcmo1-/-) model, unable to convert BC to retinoids, and wild-type mice (Bcmo1+/+) mice to dissect the effects of intact BC from effects of BC metabolites. As expected, BC supplementation resulted in a higher BC accumulation in lungs of Bcmo1-/- mice than in lungs of Bcmo1+/+ mice. Whole mouse genome transcriptome analysis on lung tissue revealed that more genes were regulated in Bcmo1-/- mice than Bcmo1+/+ mice upon BC supplementation. Frizzled homolog 6 (Fzd6) and collagen triple helix repeat containing 1 (Cthrc1) were significantly downregulated (fold changes -2.99 and -2.60, respectively, false discovery rate <0.05) by BC in Bcmo1-/-. Moreover, many olfactory receptors and many members of the protocadherin family were upregulated. Since both olfactory receptors and protocadherins have an important function in sensory nerves and Fzd6 and Cthrc1 are important in stem cell development, we hypothesize that BC might have an effect on the highly innervated pulmonary neuroendocrine cell (PNEC) cluster. PNECs are highly associated with sensory nerves and are important cells in the control of stem cells. A role for BC in the innervated PNEC cluster might be of particular importance in smoke-induced carcinogenesis since PNEC-derived lung cancer is highly associated with tobacco smoke

Downregulation of Fzd6 and Cthrc1 and upregulation of olfactory receptors and protocadherins by dietary beta-carotene in lungs of Bcmo1-/- mice.

An ongoing controversy exists on beneficial versus harmful effects of high beta-carotene (BC) intake, especially for the lung. To elucidate potential mechanisms, we studied effects of BC on lung gene expression. We used a beta-carotene 15,15'-monooxygenase 1 (Bcmo1) knockout mouse (Bcmo1-/-) model, unable to convert BC to retinoids, and wild-type mice (Bcmo1+/+) mice to dissect the effects of intact BC from effects of BC metabolites. As expected, BC supplementation resulted in a higher BC accumulation in lungs of Bcmo1-/- mice than in lungs of Bcmo1+/+ mice. Whole mouse genome transcriptome analysis on lung tissue revealed that more genes were regulated in Bcmo1-/- mice than Bcmo1+/+ mice upon BC supplementation. Frizzled homolog 6 (Fzd6) and collagen triple helix repeat containing 1 (Cthrc1) were significantly downregulated (fold changes -2.99 and -2.60, respectively, false discovery rate <0.05) by BC in Bcmo1-/-. Moreover, many olfactory receptors and many members of the protocadherin family were upregulated. Since both olfactory receptors and protocadherins have an important function in sensory nerves and Fzd6 and Cthrc1 are important in stem cell development, we hypothesize that BC might have an effect on the highly innervated pulmonary neuroendocrine cell (PNEC) cluster. PNECs are highly associated with sensory nerves and are important cells in the control of stem cells. A role for BC in the innervated PNEC cluster might be of particular importance in smoke-induced carcinogenesis since PNEC-derived lung cancer is highly associated with tobacco smoke