Climate change, local institutions and adaptation experience: the village tank farming community in the dry zone of Sri Lanka

Farmers are in a continuous process of, individually and as community groups, adjusting to the observed variability in climate parameters. Climate shocks are considered by farmers in their decision-making as factors affecting risk and uncertainty, and farmers make their choices so as to minimize such risks. The overall outcome of these individual and community efforts is known as ‘climate adaptation’, which itself is a continuous process. Farmers are traditionally supported by local institutions in this process, which are also currently in a state of transformation. This study examines the climate adaptation responses of the village tank farming community in the dry zone of Sri Lanka in the context of transforming socioeconomic conditions and with the objective of identifying policy implications for adaptation to global climate change. The study was conducted in six Divisional Secretariat areas in the Anuradhapura District of the North Central Province. Both, primary and secondary data was collected in the study. The major sources of primary data included a series of focus group discussions and key informant interviews conducted with village tank farmers and local officers. The findings reveal that there are two major forms of voluntary adaptation responses by farmers against climate shocks: 1) aligning of farming activities with the recognized seasonal pattern of rainfall; and 2) management of rain water harvested in commonly owned village tanks. Farmers’ adaptation responses have been facilitated by local institutions that helped to adopt joint adaptation responses. However, recent socioeconomic dynamics introduced by rapid population increase, spread of commercial opportunities and change in agricultural technology have drastically altered conditions in the village tanks in favor of developing a commercial farming system. As a result, local institutions that traditionally facilitated the climatic adaptation responses are also in a state of transition. Therefore, farmers face problems in adapting to the impending risks and uncertainties of global climate change. The paper emphasizes the need for appropriate policy measures to facilitate the adaptive capacity of farmers.Length: pp.147-156Climate changeAdaptationFarmersArid landsVillagesTanksCommon property

A control theorem for pp-adic automorphic forms and Teitelbaum's L\mathcal{L}-invariant

In this article, we describe an efficient method for computing Teitelbaum's $p$-adic $\mathcal{L}$-invariant. These invariants are realized as the eigenvalues of the $\mathcal{L}$-operator acting on a space of harmonic cocycles on the Bruhat-Tits tree $\mathcal{T}$, which is computable by the methods of Franc and Masdeu described in \cite{fm}. The main difficulty in computing the $\mathcal{L}$-operator is the efficient computation of the $p$-adic Coleman integrals in its definition. To solve this problem, we use overconvergent methods, first developed by Darmon, Greenberg, Pollack and Stevens. In order to make these methods applicable to our setting, we prove a control theorem for $p$-adic automorphic forms of arbitrary even weight. Moreover, we give computational evidence for relations between slopes of $\mathcal{L}$-invariants of different levels and weights for $p=2$.Comment: 26 page

Did silicon aid in the establishment of the first bacterium?

Silicic acid increased numbers of both aerobic and facultatively anaerobic bacteria in ultrapure water incubated under strict oligotrophic conditions; soil extracts acted as the bacterial inoculum. The results are discussed in relation to the possibility that silicic acid, produced by the hydrolysis of silicates on the early Earth, could have stimulated the growth of the first bacterium, thereby allowing it to become established in the then prevailing conditions (presumed to be oligotrophic)

The open cluster initial-final mass relationship and the high-mass tail of the white dwarf distribution

Recent studies of white dwarfs in open clusters have provided new constraints on the initial - final mass relationship (IFMR) for main sequence stars with masses in the range 2.5 - 6.5 Mo. We re-evaluate the ensemble of data that determines the IFMR and argue that the IFMR can be characterised by a mean initial-final mass relationship about which there is an intrinsic scatter. We investigate the consequences of the IFMR for the observed mass distribution of field white dwarfs using population synthesis calculations. We show that while a linear IFMR predicts a mass distribution that is in reasonable agreement with the recent results from the PG survey, the data are better fitted by an IFMR with some curvature. Our calculations indicate that a significant (~28%) percentage of white dwarfs originating from single star evolution have masses in excess of ~0.8 Mo, obviating the necessity for postulating the existence of a dominant population of high-mass white dwarfs that arise from binary star mergers.Comment: 5 pages, 2 color Postscript figures. Accepted for publication in MNRA

Galactic Escape Speeds in Mirror and Cold Dark Matter Models

The mirror dark matter (MDM) model of Berezhiani et al. has been shown to reproduce observed galactic rotational curves for a variety of spiral galaxies, and has been presented as an alternative to cold dark matter (CDM) models. We investigate possible additional tests involving the properties of stellar orbits, which may be used to discriminate between the two models. We demonstrate that in MDM and CDM models fitted equally well to a galactic rotational curve, one generally expects predictable differences in escape speeds from the disc. The recent radial velocity (RAVE) survey of the Milky Way has pinned down the escape speed from the solar neighbourhood to $v_{esc}=544^{+64}_{-46}$ km s$^{-1}$, placing an additional constraint on dark matter models. We have constructed an MDM model for the Milky Way based on its rotational curve, and find an escape speed that is just consistent with the observed value given the current errors, which lends credence to the viability of the MDM model. The Gaia-ESO spectroscopic survey is expected to lead to an even more precise estimate of the escape speed that will further constrain dark matter models. However, the largest differences in stellar escape speeds between both models are predicted for dark matter dominated dwarf galaxies such as DDO 154, and kinematical studies of such galaxies could prove key in establishing, or abolishing, the validity of the MDM model.Comment: Accepted for publication in the European Physical Journal

Health benefits of Green and Black Tea: A Review

Tea, (Camellia sinensis) is grown in about thirty countries and next to water, is the most widely consumed beverage in theworld. Based on the type of the processing, three tea types can be identified as Green, Black and Oolong tea. Drinking tea has beenconsidered a health-promoting habit since ancient times. The modern medicinal research isproviding a scientific basis for this belief. Various studies have suggested the health promoting effects of green and black tea is due to its polyphenolic compounds mainly catechins. Unlike green tea, health benefits of consuming black tea are not extensively discussed. This review is mainly focused on the health benefits of consuming green and black tea

Enantiospecific Detection of Chiral Nanosamples Using Photoinduced Force

We propose a high-resolution microscopy technique for enantiospecific detection of chiral samples down to sub-100-nm size based on force measurement. We delve into the differential photoinduced optical force ΔF exerted on an achiral probe in the vicinity of a chiral sample when left and right circularly polarized beams separately excite the sample-probe interactive system. We analytically prove that ΔF is entangled with the enantiomer type of the sample enabling enantiospecific detection of chiral inclusions. Moreover, we demonstrate that ΔF is linearly dependent on both the chiral response of the sample and the electric response of the tip and is inversely related to the quartic power of probe-sample distance. We provide physical insight into the transfer of optical activity from the chiral sample to the achiral tip based on a rigorous analytical approach. We support our theoretical achievements by several numerical examples highlighting the potential application of the derived analytic properties. Lastly, we demonstrate the sensitivity of our method to enantiospecify nanoscale chiral samples with chirality parameter on the order of 0.01 and discuss how the sensitivity of our proposed technique can be further improved

Scanning thermal profiler

Journal ArticleA new high-resolution profilometer has been demonstrated based upon a noncontacting nearfield thermal probe. The thermal probe consists of a thermocouple sensor with dimensions approaching 100 nm. Profiling is achieved by scanning the heated sensor above but close to the surface of a solid. The conduction of heat between tip and sample via the air provides a means for maintaining the sample spacing constant during the lateral scan. The large difference in thermal properties between air and solids makes the profiling technique essentially independent of the material properties of the solid. Noncontact profiling of resist and metal films has shown a lateral resolution of 100 nm and a depth solution of 3 nm. The basic theory of the new probe is described and the results presented

High resolution thermal microscopy

Journal ArticleA new high resolution thermal microscope has been demonstrated capable of imaging thermal fields with sub 1000 angstom resolution. It is based upon a non-contacting near field thermal probe. The thermal probe consists of a thermocouple sensor on the end of a tip with sub 1000 angstrom dimensions. The probe tip is scanned in close proximity to a solid or liquid surface and the local temperature is mapped with a resolution determined by the size of the tip. Material independent surface profiling has also been demonstrated with the thermal probe, providing a lateral resolution of approximately 300 angstroms. Temperature mapping and surface profiling results are presented on both electronic and biological materials

“Tell me what I should watch”: A customer value perspective of YouTube metadata

YouTube is increasingly being considered a lucrative means of earning money in addition to becoming popular among viewers. To gain these benefits YouTube content creators (YouTubers) need to first attract viewers’ attention to their videos and then persuade them to watch. YouTube metadata, such as the title, thumbnail, description, and keywords, can assist in achieving both objectives. This has been established in the current literature which shows, for example, that metadata optimizing can increase view counts. While these studies have demonstrated the end result of metadata optimization, they do not indicate why viewers respond to different characteristics of metadata in different ways. We contribute to the literature on marketing and consuming YouTube videos by examining, using Holbrook’s (1999) value typology for theorisation, how viewers experience the metadata and how these experiences contribute to the overall value creation process of watching YouTube videos. We employed an interpretive, qualitative research design in conducting the study, using focus group discussions with 21 young YouTube viewers as the data collection method. Data were analysed using thematic analysis. Key findings were that metadata can both deliver value (efficiency) and provide signals about values delivered through the video (excellence and aesthetics). Further, the play value viewers get from interacting with the video is indirectly influenced by the metadata. We also identified that although viewers commonly expect some characteristics in the title and thumbnail, irrespective of their purpose of using YouTube, the importance of each differs when they seek information or entertainment gratification. Further, when value promises made by the metadata are not delivered through the videos, viewers respond negatively. Keywords: Entertainment gratification, Information gratification, Metadata optimization, Value, YouTub