LabVIEW interface with Tango control system for a multi-technique X-ray spectrometry IAEA beamline end-station at Elettra Sincrotrone Trieste

A new synchrotron beamline end-station for multipurpose X-ray spectrometry applications has been recently commissioned and it is currently accessible by end-users at the XRF beamline of Elettra Sincrotrone Trieste. The end-station consists of an ultra-high vacuum chamber that includes as main instrument a seven-axis motorized manipulator for sample and detectors positioning, different kinds of X-ray detectors and optical cameras. The beamline end-station allows performing measurements in different X-ray spectrometry techniques such as Microscopic X-Ray Fluorescence analysis (µXRF), Total Reflection X-Ray Fluorescence analysis (TXRF), Grazing Incidence/Exit X-Ray Fluorescence analysis (GI-XRF/GE-XRF), X-Ray Reflectometry (XRR), and X-Ray Absorption Spectroscopy (XAS). A LabVIEW Graphical User Interface (GUI) bound with Tango control system consisted of many custom made software modules is utilized as a user-friendly tool for control of the entire end-station hardware components. The present work describes this advanced Tango and LabVIEW software platform that utilizes in an optimal synergistic manner the merits and functionality of these well-established programming and equipment control tools

Repairing political trust in Tunisia

Purpose: this study aims to identify the responses required to repair political trust in Tunisia and the differences between two key stakeholder groups, namely politicians and voters. Design/methodology/approach: A qualitative longitudinal study was adopted using two data sources: media data from TV political talk shows; and semi-structured interviews conducted with citizens and politicians. Data was collected following several key events that violated trust. Findings: New responses were identified to repair political trust and these were categorized using a trust repair framework. In addition to short and long-term responses a new category, swift response, was identified to resolve immediate political uncertainty. The role of the trustor (i.e. voters) in actively restoring trust was identified for the first time. Research limitations: This study focused on trust repair responses suggested by voters and politicians and not responses that were implemented by the government or political parties during the period of study. The effectiveness of the suggested responses in repairing trust was not therefore evaluated. Practical implications: Identification of the responses required to repair trust with voters and how these differ over time and according to different trust violations will help Tunisian politicians rebuild trust more effectively during election and non-election periods. Notably, differences highlighted between the responses suggested by voters and politicians suggest that politicians may not understand how to repair voter trust. Originality/value: Contrary to previous studies that assume a trustor (the voter) is a passive observer, this research identified the proactive role that citizens play in the trust repair process

RHEED digital image analysis system for in-situ growth rate and alloy composition measurements of GaAs-based nanostructures

Monitoring the intensity of the reflected spot in a RHEED image is the most important method used to control the growth of semiconductors in MBE. The accurate control of both layer thickness and alloy composition is particularly important for the growth of high quality heterostructures. Indeed, under such conditions, extremely uniform and high quality epitaxial devices become possible. RHEED intensity oscillation can be used as accurate, quick and direct measure of the growth rates and alloy compositions as well. Although analog signal could be obtained by using an optical fiber associated to a photo-detector PM tube and a plotter, this method is troublesome and limited. In some application, the availability of the intensity signal as a digital voltage is useful to realize further advanced analysis, and achieve feedback between growth dynamic and the external parameters, such as the cells temperatures and the synchronization of the shutters. In this paper we describe the advantages gained with the upgrade of our analog system into a digital package using CCD camera, frame grabber and a home made software. Its main purpose is to track RHEED intensity changes and measures the rate of oscillation. A state-of-the-art RHEED digital image analysis system gives us the necessary tools to gain insight into the thin film growth process and optimize material quality

Alien marine species of Libya: first inventory and new records in El-Kouf National Park (Cyrenaica) and the neighbouring areas

The presence of marine alien species in El-Kouf National Park and the neighbouring areas was assessed using a compilation of available information and observations, a field survey conducted on October 2010 in the framework of the MedMPAnet project and results of further monitoring during June and September 2012. A total of 9 alien species were reported: the Rhodophyta Asparagopsis taxiformis (Delile) Trevisan de Saint-Léon, the Chlorophyta Caulerpa racemosa var. cylindracea (Sonder) Verlaque, Huisman & Boudouresque, the crab Percnon gibbesi (H. Milne-Edwards, 1853) and the fishes Fistularia commersonii Rüppell, 1838, Siganus luridus (Rüppell, 1829), Siganus rivulatus Forsskål, 1775, Pempheris vanicolensis Cuvier, 1831, Lagocephalus sceleratus (Gmelin, 1789) and Sphyraena flavicauda Rüppell, 1838. Several of them were until now unknown for the National Park. The list of alien marine species of Libya is updated and discussed. Until now 63 marine aliens species were recorded along the Libyan coasts. These include 3 Foraminifera, 3 Ochrophyta, 5 Rhodophyta, 5 Chlorophyta, 1 Magnoliophyta, 11 Arthropoda, 13 Mollusca, 1 Echinodermata and 21 Chordata. Among these Non Indigenous Species, 43 are known as established along the Libyan coast including 8 invasive, 11 casual, 6 questionable, 3 cryptogenic and 1 unknown. An in-depth study of the marine organisms would substantially increase the number of alien species occurring in Libya. Monitoring of marine assemblages of MPAs is a valuable opportunity to go further into the knowledge of native and introduced species

Assessing of growth, antioxidant enzymes, and phytohormone regulation in Cucurbita pepo under cadmium stress

One of the major problems worldwide is soil pollution by trace metal elements, which limits plant productivity and threatens human health. In this work, we have studied the effect of different concentrations of cadmium on Cucurbita pepo plants, evaluating different physiological and biochemical parameters: hormone signaling, metabolite concentration (malondialdehyde and hydrogen peroxide) and, in addition, the antioxidant enzyme activities of catalase and superoxide dismutase were evaluated. The production of biomass decreased under the Cd‐stress. The results showed that C. pepo accumulates higher amounts of Cd2+ in roots than in shoots and fruits. Cd2+ differently affected the content of endogenous phytohormones. Furthermore, data suggest an essential involvement of roots in the regulation of tolerance to trace elements. As a result, indole acetic acid content increased in roots of treated plants, indicating that this phytohormone can stimulate root promotion and growth under Cd‐stress. Similarly, salicylic acid content in roots and shoots increased in response to Cd2+, as well as abscisic acid levels in roots and fruits. In roots, the rambling accumulation pattern observed for jasmonic acid and salicylic acid suggests the lack of a specific regulation role against trace element toxicity. The activity of catalase and superoxide dismutase decreased, disrupted by the metal stress. However, the proline, malondialdehyde and hydrogen peroxide content significantly increased in Cd2+in all the analyzed tissues of the stressed plants. All these data suggest that C. pepo plants are equipped with an effective antioxidant mechanism against oxidative stress induced by cadmium up to a concentration of 500 μM

The role of temperature on the germination activity of leguminous crops exposed to saline conditions

Germination is an important starting point of plant life. Abiotic stresses during the germination stage in seeds can threaten the development process of a plant species. Abiotic factors such as temperature and salt concentration influence the germination process of various crop seeds, including leguminous species. The aim of this study is to determine the germination rate and seedling growth of leguminous cover crops under two different temperatures and four levels of salt stress. Alfalfa (Medicago sativa), red clover (Trifolium pratense), and chickpea (Cicer arietinum) were studied in this in vitro trial. The study results showed that the increase in sodium chloride (NaCl) concentration suppressed the growth of the germinated seedlings. At the same time, the increase in temperature reduced the germination rate of red clover and chickpea at higher salt concentrations. The data also showed a significant relationship between salt concentration and temperature on shoot and radicle growth in all three leguminous species. These data may benefit farmers and growers trying to cultivate these crops in unfavorable conditions

Introduced marine macroflora of Lebanon and its distribution on the Levantine coast

The marine macroflora introduced into Lebanon was studied through an analysis of historical data and field studies carried out since 1991. A total of 29 introduced species have been listed: 3 Chromobionta, 13 Rhodobionta, 12 Chlorobionta and 1 Streptobionta. Among them, Caulerpa taxifolia var. distichophylla, Spatoglossum variabile and Womersleyella setacea are recorded for the first time from Lebanon. Among them, Asparagopsis taxiformis, C. taxifolia var. distichophylla, Cladophora patentiramea, Codium arabicum, Codium parvulum, Galaxaura rugosa, Halophila stipulacea, Hypnea cornuta, Laurencia cf. chondrioides, Lophocladia lallemandii, Stypopodium schimperi, Ulva lactuca and Womersleyella setacea are potentially invasive species, and several of them already occupy extensive stretches of the Lebanese coast. The distribution of species on the Levantine coast, their dynamics and the current status of their populations are discussed.The surveys in 2012, 2013 and 2016 were conducted within the framework of the MedMPAnet Project, implemented by UNEP/MAP-RAC/SPA and funded by RAC/SPA, the European Commission (EC), the Spanish Agency for International Cooperation for Development (AECID), and the French Global Environment Facility (FFEM)

Comparative Analysis of CBRM Cases in Kenya, Ethiopia and Tunisia

In various countries, development and conservation organizations and national policymakers have been experimenting with ways of applying the community-based natural resource management approach to the unique social and biophysical characteristics of pastoralist rangeland settings, with mixed results. We carried out comparative case study research on community-based rangeland management (CBRM) in a variety of settings in Ethiopia, Kenya and Tunisia with the objective of identifying what kinds of strategies and methods work in which social and ecological contexts. We used an “options by context” approach guided by a research protocol that includes key variables and descriptors for characterizing the implementing organization’s approach to CBRM and important contextual factors that may vary from place to place and affect the implementation and success of the approach. The commonalities among our cases include: i) community governance and management structures for rangeland management; ii) the geographic rangeland unit which those structures are managing, and iii) a development agent that is supporting the community. We found that differences among the cases in the challenges faced and their degree of success depended at least as much on certain aspects of social and biophysical context as it did on the exact nature of the approach being implemented by the development agent. For example, the extent to which there are effective natural or social borders that provide the rangeland community with some degree of separation from neighbours is crucial; without such landscape features, the design principle of clearly defined rights to a clearly defined piece of land belonging to a clearly defined community is difficult to implement in any straightforward way. In some pastoral rangeland contexts, conventional community-based approaches need substantial modification to be effective in contexts with the highest levels of spatio-temporal variability, mobility and openness of the landscape