Flore ("Pteridophyta" et "Spermatophyta") des zones humides du Maroc Méditérranéen: Inventaire et écologie

Despite the interest that one wears increasingly to wetlands through the world, few studies have been devoted to Moroccan wetland flora. After having prospected 45 sites, we have evaluated the specific diversity of wetland flora from 70 floristic inventories. Among 389 recognised species in this study, 175 are wetland species. Rare species or newly quoted have been underlined. On the other hand, the observed plant groupings have been classified according to the physiognomy and the specific composition. A particular attention has been devoted to the discussion of the main ecological factors affecting wetland plant groupings namely : the submersion, the salinity, the domestic organic loading, the local climate and the anthropic perturbations. Thereby, we have ranked dominant species in some ecological groups.Malgré l'intéret qu' on porte de plus en plus aux zones humides á travers le monde, peu d' etudes ont été consacrées á la flore hygrophile marocaine. Aprés avoir prospecté 45 stations, on a évalué la diversité spécifique des hygrophytes du Maroc méditerranéen á partir de 70 relevés floristiques. Sur les 389 espéces reconnues dans cette etude, 175 especes sont caractéristiques des zones humides. Les espéces rares ou nouvellement citées ont été soulignées. D'autre part, les phytocenoses observées ant été classées en fonction de la physionomie et de la composition spécifique. Une attention particuliere a été consacrée á la discussion des principaux facteurs écologiques influant sur les groupements hygrophiles á savoir : la submersion, la salinité, la charge organique domestique, le mésoclimat et les travaux d'aménagement. Ainsi, on a pu regrouper les espéces dominantes en classes écologiques

Environmental Biotechnology Screening Cu and Cd tolerance in Salix species from North Morocco

Hydroponic culture has been used to compare copper and cadmium tolerance in five Salix species from North Morocco using different approaches. Measurements of growth parameters have been combined with those of some photosynthetic parameters. Tolerance index based either on root or shoot growth allowed to define Salix pedicelata and Salix purpurea as Cu and Cd-tolerant species, respectively. From the methodological point of view, the use of tolerance index based on aerial part growth, appeared mostadequate for the screening of metal tolerance in woody plants. On the other hand, no significant effect on chlorophyll content was observed under treatment with either Cu or Cd, in any of the Salix species analyzed. In vitro experiments with thylakoid membranes showed that the effects on the electron transport chain differ for each metal and species used. Furthermore, it seems that metal tolerance at the chloroplast level is distinct to that of the whole plant

Is a multiple excitation of a single atom equivalent to a single excitation of an ensemble of atoms?

Recent technological advances have enabled to isolate, control and measure the properties of a single atom, leading to the possibility to perform statistics on the behavior of single quantum systems. These experiments have enabled to check a question which was out of reach previously: Is the statistics of a repeatedly excitation of an atom N times equivalent to a single excitation of an ensemble of N atoms? We present a new method to analyze quantum measurements which leads to the postulation that the answer is most probably no. We discuss the merits of the analysis and its conclusion.Comment: 3 pages, 3 figure

Analysis of Maize Value Addition among Entrepreneurs in Taraba State, Nigeria

This study analyzed maize value addition among maize entrepreneurs in Taraba State, Nigeria. A multi-stage sampling procedure was used to collect primary data from two hundred and twelve respondents (212), using structured questionnaire. Data were analyzed using descriptive statistics, Value addition model, ANOVA, multinomial logistic regression, log likelihood test ratio and factor analysis. The result of the study revealed that most (62.3%) respondents were males. 61.3% were within the productive age of 21-40 years. Majority (71.1%) were married with household sizes of 6-10. The total of (32.8%) respondents of them had secondary school education, (46.6%) had processing experience of between 6-10 years in processing as their major occupation. proportionate (49.2%) of total respondents had non-farm income of N150,001 per annum. Results of the value addition analysis showed that maize processed as boiled maize is more profitable with a mean of N130, 900 per annum. The result from the multinomial logistic regression on choice of maize processing enterprises revealed that sex had negative coefficient, which implied that male respondents preferred grain production enterprise rather than processing into akamu, corn flour, massa and boiled maize. Also age had negative coefficient, implying that age increase tends to favour grain production than processing. In relation to processing constraints, the maize processing value chain was hampered by the following: inadequate processing facilities, inadequate credit/funds, high cost of transport and inadequate access to inputs. The study concluded that maize value addition is a profitable enterprise and entrepreneurs should be encouraged to venture into it. Also the Agricultural Development Project Programme should send extension agents to processors to encourage processing diversification especially into poultry feeds

Factors Influencing Commercialization of Horticultural Crops Among Smallholder Farmers in Juba, South Sudan

This paper aims at analyzing socio-economic and institutional factors influencing the commercialization of horticultural crops among smallholder farm households in Juba, South Sudan. The study adopted a multi-stage sampling technique to select a sample of 151 respondents. The survey was conducted using semi-structured questionnaires to collect primary data. The data collected were analyzed using descriptive statistics and a Tobit regression model by STATA analytical software. The results from descriptive statistics indicated that 77.48% of the farmers are female, 36.65% have access to land, 37.09% have access to education at the primary level, 96.69% have no access to market information, 74.17% do not have group membership and only 54.97% have access to irrigation facilities. The findings further revealed that the mean household commercialization index (HCI) was 74.81% and the specific HCI for the selected vegetable crops; tomato, okra and cowpeas were 74.92%, 72.96%, and 74.84% respectively. The results from the Tobit regression model revealed that commercialization of horticultural crops is influenced by the age of the farmer, farming experience, type of land acquisition, the quantity of crop produced, group membership, total variable costs, total farm revenue, and access to irrigation facilities. The finding revealed that the age of a farmer, types of crop produced, type of land acquisition, and group membership are negatively significant whereas, farming experience, total variable costs, total farm revenue, and access to irrigation facilities are positively significant. The study suggests that further evaluation of the factors influencing the commercialization of indigenous and exotic vegetables would be required in rural and peri-urban settings of South Sudan. This study provides an insight for policymakers to formulate appropriate policies that can promote domestic production and accelerate the transition of smallholder farmers from subsistence to the market-oriented production system. Keywords: Commercialization, Horticultural crops, Peri-urban areas, smallholder, Tobit regression model DOI: 10.7176/JESD/12-14-05 Publication date:July 31st 202

From Traditional Farming in Morocco to Early Urban Agroecology in Northern Mesopotamia: Combining Present-day Arable Weed Surveys and Crop Isotope Analysis to Reconstruct Past Agrosystems in (Semi-)arid Regions

Published by Informa UK Limited, trading as Taylor & Francis GroupWe integrate functional weed ecology with crop stable carbon and nitrogen isotope analysis to assess their combined potential for inferring arable land management practices in (semi-)arid regions from archaeobotanical assemblages. Weed and GIS survey of 60 cereal and pulse fields in Morocco are combined with crop sampling for stable isotope analysis to frame assessment of agricultural labour intensity in terms of manuring, irrigation, tillage and hand-weeding. Under low management intensity weed variation primarily reflects geographical differences, whereas under high management intensity fields in disparate regions have similar weed flora. Manured and irrigated oasis barley fields are clearly discriminated from less intensively manured rain-fed barley terraces in southern Morocco; when fields in northern and southern Morocco are considered together, climatic differences are superimposed on the agronomic intensity gradient. Barley δ13C and δ15N values clearly distinguish among the Moroccan regimes. An integrated approach combines crop isotope values with weed ecological discrimination of low- and high-intensity regimes across multiple studies (in southern Morocco and southern Europe). Analysis of archaeobotanical samples from EBA Tell Brak, Syria suggests that this early city was sustained through extensive (low-intensity, large-scale) cereal farming

On the Web Platform Cornucopia

Peer reviewe

Weak localization in disordered systems at the ballistic limit

The weak localization (WL) contribution to the two-level correlation function is calculated for two-dimensional disordered conductors. Our analysis extends to the nondiffusive (ballistic) regime, where the elastic mean path is of order of the size of the system. In this regime the structure factor (the Fourier transform of the two-point correlator) exhibits a singular behavior consisting of dips superimposed on a smooth positive background. The strongest dips appear at periods of the periodic orbits of the underlying clean system. Somewhat weaker singularities appear at times which are sums of periods of two such orbits. The results elucidate various aspects of the weak localization physics of ballistic chaotic systems.Comment: 13 pages, 13 figure

Phase II TPDCV protocol for pediatric low-grade hypothalamic/chiasmatic gliomas: 15-year update

To report long-term results for children with low-grade hypothalamic/chiasmatic gliomas treated on a phase II chemotherapy protocol. Between 1984 and 1992, 33 children with hypothalamic/chiasmatic LGGs received TPDCV chemotherapy on a phase II prospective trial. Median age was 3.0 years (range 0.3–16.2). Twelve patients (36%) underwent STRs, 14 (42%) biopsy only, and seven (21%) no surgery. Twenty patients (61%) had pathologic JPAs, nine (27%) grade II gliomas, and four (12%) no surgical sampling. Median f/u for surviving patients was 15.2 years (range 5.3–20.7); 20 of the 23 surviving patients had 14 or more years of follow-up. Fifteen-year PFS and OS were 23.4 and 71.2%, respectively. Twenty-five patients progressed, of whom 13 are NED, two are AWD, and 10 have died. All children who died were diagnosed and first treated at age three or younger. Age at diagnosis was significantly associated with relapse and survival (P = 0.004 for PFS and P = 0.037 for OS). No PFS or OS benefit was seen with STR versus biopsy/no sampling (P = 0.58 for PFS, P = 0.59 for OS). For patients with JPAs and WHO grade II tumors, the 15-year PFS was 18.8 and 22.2% (P = 0.95) and 15-year OS was 73.7 and 55.6% (P = 0.17), respectively. Upfront TPDCV for children with hypothalamic/chiasmatic LGGs resulted in 15-year OS of 71.2% and 15-year PFS of 23.4%. No survival benefit is demonstrated for greater extent of resection. Age is a significant prognostic factor for progression and survival