Finite Dimension Wyner-Ziv Lattice Coding for Two-Way Relay Channel

International audienceTwo-way relay channel (TWRC) models a cooperative communication situation performing duplex transmission via a relay station. For this channel, we have shown previously that a lattice-based physical layer network coding strategy achieves, at the limit of arbitrarily large dimension, the same rate as that offered by the random coding-based regular compress-and-forward. In this paper, we investigate a practical coding scheme using finite dimension lattices and offering a reasonable performance-complexity trade-off. The algorithm relies on lattice based quantization for Wyner-Ziv coding. We characterize the rate region allowed by our coding scheme, discuss the design criteria, and illustrate our results with some numerical examples

Elevated CO2has concurrent effects on leaf and grain metabolism but minimal effects on yield in wheat

While the general effect of CO2 enrichment on photosynthesis, stomatal conductance, N content, and yield has been documented, there is still some uncertainty as to whether there are interactive effects between CO2 enrichment and other factors, such as temperature, geographical location, water availability, and cultivar. In addition, the metabolic coordination between leaves and grains, which is crucial for crop responsiveness to elevated CO2, has never been examined closely. Here, we address these two aspects by multi-level analyses of data from several free-air CO2 enrichment experiments conducted in five different countries. There was little effect of elevated CO2 on yield (except in the USA), likely due to photosynthetic capacity acclimation, as reflected by protein profiles. In addition, there was a significant decrease in leaf amino acids (threonine) and macroelements (e.g. K) at elevated CO2, while other elements, such as Mg or S, increased. Despite the non-significant effect of CO2 enrichment on yield, grains appeared to be significantly depleted in N (as expected), but also in threonine, the S-containing amino acid methionine, and Mg. Overall, our results suggest a strong detrimental effect of CO2 enrichment on nutrient availability and remobilization from leaves to grains.This work was supported by the Department of Industry, Energy and Innovation of the Government of Navarre (PI040 TRIGOCLIM). The technical support given by Inés Urretavizcaya, Petra Högy, and Jürgen Franzaring in harvesting and sample management is acknowledged. JC was supported by an Australia Awards PhD Scholarship. GT was supported by a Connect Talent Award from the Region Pays de la Loire – Angers Loire Metropole (France). Research at the Australian Grains Free Air CO2 Enrichment (AGFACE) facility was jointly run by the University of Melbourne and Agriculture Victoria with funding from the Grains Research and Development Corporation (under contract no. DAV00137) and the Australian Commonwealth Department of Agriculture and Water Resources (under contract no. FtRG 1193982-41). CAAS-FACE was supported by the National Key Research and Development Project (under contracts 2016YFD0300401 and 2019YFA0607403). The FACE experiment in Italy was supported by the AGER project ‘Durum wheat adaptation to global change: effect of elevated CO2 on yield and quality traits’ and by the collaboration CREA-CNR. Finally, the authors also acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI)

Elevated CO2 has concurrent effects on leaf and grain metabolism but minimal effects on yield in wheat

While the general effect of CO2 enrichment on photosynthesis, stomatal conductance, N content, and yield has been documented, there is still some uncertainty as to whether there are interactive effects between CO2 enrichment and other factors, such as temperature, geographical location, water availability, and cultivar. In addition, the metabolic coordination between leaves and grains, which is crucial for crop responsiveness to elevated CO2, has never been examined closely. Here, we address these two aspects by multi-level analyses of data from several free-air CO2 enrichment experiments conducted in five different countries. There was little effect of elevated CO2 on yield (except in the USA), likely due to photosynthetic capacity acclimation, as reflected by protein profiles. In addition, there was a significant decrease in leaf amino acids (threonine) and macroelements (e.g. K) at elevated CO2, while other elements, such as Mg or S, increased. Despite the non-significant effect of CO2 enrichment on yield, grains appeared to be significantly depleted in N (as expected), but also in threonine, the S-containing amino acid methionine, and Mg. Overall, our results suggest a strong detrimental effect of CO2 enrichment on nutrient availability and remobilization from leaves to grains.This work was supported by the Department of Industry, Energy and Innovation of the Government of Navarre (PI040 TRIGOCLIM). The technical support given by Inés Urretavizcaya, Petra Högy, and Jürgen Franzaring in harvesting and sample management is acknowledged. JC was supported by an Australia Awards PhD Scholarship. GT was supported by a Connect Talent Award from the Region Pays de la Loire – Angers Loire Metropole (France). Research at the Australian Grains Free Air CO2 Enrichment (AGFACE) facility was jointly run by the University of Melbourne and Agriculture Victoria with funding from the Grains Research and Development Corporation (under contract no. DAV00137) and the Australian Commonwealth Department of Agriculture and Water Resources (under contract no. FtRG 1193982-41). CAAS-FACE was supported by the National Key Research and Development Project (under contracts 2016YFD0300401 and 2019YFA0607403). The FACE experiment in Italy was supported by the AGER project ‘Durum wheat adaptation to global change: effect of elevated CO2 on yield and quality traits’ and by the collaboration CREA-CNR. Finally, the authors also acknowledge support of the publication fee by the CSIC Open Access Publication Support Initiative through its Unit of Information Resources for Research (URICI

Penerapan Kode Etik Pustakawan di Perpustakaan Universitas Negeri Padang

Writing this article aims to describe (1) the implementation of the code of ethica librarian at the Librarian of the University of Padang; (2) the obstacles ancounteredin the implementation of the code of ethics oflibrarians and describe the efforts made to overcome the obstacles in the implementation of the code of ethics of librarians. Data collected by observation and interview with the librarian at the Library of the State University of Padang. Data analisis was done descriptively, it can be concluded that (1) Librarian Padang State University has been applying the basic attitude of librarians with the users, the relationship between librarians, community relations. But not all librarians are able to apply the code of conduct in the workplace, there are still many librarians who only know the code of ethics of librarians without applying the code of ethics of librarians; (2) in moking application of the Code Librarian at the Library of the University of Padang still has many obstacles, obstacles encounteredis the lack of know ledge of librarians about the basic attitude of librarians and do not know the code of ethics as a librarian professionals, lack of talent librarians to communicate and get along, so librarian hostility in serving meanwhile, efforts to be made by librarians terkain this obstacle is not maximized

Social accountability and poverty reduction in Tanzania: a case of selected local government authorities

Journal of Public Sector Management, 2013; 2 (2): 1-45Accountability as a concept as per the Tanzania's central and Local Governments Authorities (LGA's) literally means the LGAs measure of compliance to government set guidelines and rules for financial, administrative and policy implementation as opposed to the public demand for accessibility to information, priority setting, peoples participation, public services and decision making. The practical evidence of failing development projects and programmes, deepening poverty, socio-economic inequalities and gender injustices present strong challenges, especially for initiatives under 'traditional' government approaches, resulting in demands for the rethinking of development. The current study mainly aimed at determining whether LGA's were socially accountable to their residents' thus contributing topoverty reduction. Specifically, the study aimed at assessing the LGA's budgetary allocation and utilization to the sectors of agriculture, health, education and infrastructure, which are important areas for poverty reduction. In collaboration with localpeople and their organizations and community groups, CSOs have been able to collect and analyze Council information deducting inefficiencies, lack of capacities, financial mismanagement; fund misuse, underutilization and under expenditures mostly on the development budget. These are some of the key indicators of lack of social accountability of the councils to the people they are supposed to serve. On the other hand, some Councils have indicated their willingness to account to localpeoples' concerns while addressing shortfalls and lack of capacity to implement what is expected of their dues

Carbohydrate and amino acid dynamics during grain growth in four temperate cereals under well-watered and water-limited regimes

Grain development in cereals depends on synthesis and remobilisation compounds such as water-soluble carbohydrates (WSCs), amino acids (AAs), minerals and environmental conditions during pre-and post-anthesis. This study analyses the impact of water stress on metabolite (WSCs, AAs and nitrogen) dynamics between the source (leaves and stems) and sink (grain) organs in triticale, bread wheat, durum wheat and barley. Plants were grown in glasshouse conditions under well-watered (WW) and water-limited (WL) regimes (from flag leaf fully expanded until maturity). The results showed that the stem WSC content and the apparent mobilisation of WSC to the grain were much higher in triticale and were associated with its larger grain size and grain number. In the four cereals, grain weight and the number of kernels per spike were positively associated with stem WSC mobilisation. After anthesis, the AA concentration in leaves was much lower than in the grain. In grain, the main AAs in terms of concentration were Asn, Pro and Gln in triticale, bread, and durum wheat, and Asn, Pro and Val in barley. The water-limited regime reduced grain weight per plant in the four cereal species, but it had no clear effects on WSC content and AAs in leaves and grain. In general, triticale was less affected by WL than the other cereals.The first author (A.M.M.-E.) was supported by FONDECYT Postdoc 3160687. The research was funded by the grants, FONDECYT N 1150353 and 118025

Groundwater recharge in sub-humid drylands under different agricultural systems

Groundwater is a strategic long-term water resource used by an estimated 70% of the populations in sub-Saharan Africa for drinking, irrigation and a wide range of economic activities. Understanding groundwater recharge processes is key for effectively using and managing water resources. Very few studies have used direct groundwater observations to assess the impact of different farming systems on groundwater recharge processes. This study focused on assessing basement aquifer recharge in 4 instrumented catchments in Malawi (Chitedze), Zambia (Liempe and Kabeleka) and Zimbabwe (Domboshawa) within the SADC region between 2019-2022. Employing a range of methods, including direct field observations (groundwater hydrographs, precipitation data, stable isotopes, chloride mass balance and residence time tracer data), we quantify the amount of groundwater recharge as well as the timing and nature of recharge processes under both conservation and conventional tillage systems in these four study sites. Groundwater recharge was measured in most years across the study sites. The study reveals the strong climate controls on seasonal groundwater recharge volumes, the influence of low permeability layers in the unsaturated zone, and the likely magnitude of impact from different farming practices. Groundwater residence times are high (i.e. low fractions of modern recharge, interquartile range 1-5%, n=46), even in shallow piezometers, suggesting these unpumped systems may be highly stratified. The results provide an evidence-based suite of data that reveals much about key controls on groundwater recharge in basement aquifers in sub-humid drylands and will inform the development and management of such groundwater systems. Keywords: Groundwater recharge, basement aquifers, Southern Africa Development Community (SADC

Assessing differences in groundwater recharge flows under conservation agriculture and conventional tillage

Under the pressure of growing populations and risks to food security by increased extreme weather events (droughts and floods), many countries, particularly in semi-arid and arid regions, such as sub-Saharan Africa have promoted a shift to climate-smart agricultural systems such as conservation agriculture (CA). The core principles of CA, along with crop diversification/rotation, comprise minimum tillage and mulching, and previous studies indicate positive effects of these practices on soil moisture balance. However, effects of CA on groundwater recharge, for example changes to quantities, timing or altered recharge pathways have scarcely been investigated in the sub-Sahara environment, and need consideration because they may affect not only groundwater renewability, but potentially also contaminant transport and therefore groundwater quality. In this study, we introduce a plot-scale approach at three sites in Zambia, Zimbabwe and Malawi using a suite of investigation methods to characterize recharge patterns under CA and conventionally tilled plots. In our presented setup, high-resolution (30 minutes) groundwater level and weather data are complemented by monthly groundwater chemistry (major, minor, and trace elements) and stable water isotope analysis from shallow monitoring boreholes over a monitoring period of multiple (2—3) recharge seasons. Annual repeat measurements of residence time tracers (CFCs and SF6) add additional information on groundwater age. Preliminary data analysis indicates that differences in onset and pattern of groundwater recharge between conventionally tilled and CA treatment plots can be observed, which could be valuable information for example in informing best management such as timing of fertilizer and pesticide application. The results of this study can therefore inform policy and decision makers and further our understanding of the effects promoted land use changes may have on local groundwater resources