Introduction and Overview

Global Agricultural Trade and Developing Countries explores the outstanding issues in global agricultural trade policy and evolving world production and trade patterns. This book presents research findings based on a series of commodity studies of significant economic importance to developing countries. Setting the stage with background chapters and investigations of cross-cutting issues, the authors describe trade and domestic policy regimes affecting agricultural and food markets and analyze product standards and compliance costs and their effects on agricultural and food trade. They then examine the impact and effectiveness of preferences and review the evidence on attempts to decouple agricultural support from agricultural output. Finally, they assess the potential gains from global liberalization in agricultural and food markets, and their sensitivity to various assumptions. Within this broad context of global agricultural policies and reforms, the authors then present detailed studies of commodity markets that feature distorted policy regimes among industrial and developing countries or that are important contributors to exports of developing countries. The commodities analyzed are sugar, dairy, rice, wheat, groundnuts, fruits and vegetables, cotton, seafood, and coffee. These commodity studies analyze current policy regimes in key producing and consuming countries, document the magnitude of these distortions, and estimate the distributional impacts-winners and losers-of trade and domestic policy reforms as well as their impact on trade flows and production location. Global Agricultural Trade and Developing Countries will aid policymakers and researchers in approaching global negotiations and in evaluating domestic policies on agriculture. This book compliments the findings of Agriculture and the WTO: Creating a Trading System for Development.

Maximum likelihood estimation of Gaussian mixture models using stochastic search

Cataloged from PDF version of article.Gaussian mixture models (GMM), commonly used in pattern recognition and machine learning, provide a flexible probabilistic model for the data. The conventional expectation-maximization (EM) algorithm for the maximum likelihood estimation of the parameters of GMMs is very sensitive to initialization and easily gets trapped in local maxima. Stochastic search algorithms have been popular alternatives for global optimization but their uses for GMM estimation have been limited to constrained models using identity or diagonal covariance matrices. Our major contributions in this paper are twofold. First, we present a novel parametrization for arbitrary covariance matrices that allow independent updating of individual parameters while retaining validity of the resultant matrices. Second, we propose an effective parameter matching technique to mitigate the issues related with the existence of multiple candidate solutions that are equivalent under permutations of the GMM components. Experiments on synthetic and real data sets show that the proposed framework has a robust performance and achieves significantly higher likelihood values than the EM algorithm. (C) 2012 Elsevier Ltd. All rights reserved

Global Agricultural Trade and Developing Countries

Global Agricultural Trade and Developing Countries explores the outstanding issues in global agricultural trade policy and evolving world production and trade patterns. This book presents research findings based on a series of commodity studies of significant economic importance to developing countries. Setting the stage with background chapters and investigations of cross-cutting issues, the authors describe trade and domestic policy regimes affecting agricultural and food markets and analyze product standards and compliance costs and their effects on agricultural and food trade. They then examine the impact and effectiveness of preferences and review the evidence on attempts to decouple agricultural support from agricultural output. Finally, they assess the potential gains from global liberalization in agricultural and food markets, and their sensitivity to various assumptions. Within this broad context of global agricultural policies and reforms, the authors then present detailed studies of commodity markets that feature distorted policy regimes among industrial and developing countries or that are important contributors to exports of developing countries. The commodities analyzed are sugar, dairy, rice, wheat, groundnuts, fruits and vegetables, cotton, seafood, and coffee. These commodity studies analyze current policy regimes in key producing and consuming countries, document the magnitude of these distortions, and estimate the distributional impacts-winners and losers-of trade and domestic policy reforms as well as their impact on trade flows and production location. Global Agricultural Trade and Developing Countries will aid policymakers and researchers in approaching global negotiations and in evaluating domestic policies on agriculture. This book compliments the findings of Agriculture and the WTO: Creating a Trading System for Development.

Tsetse fly (Glossina pallidipes) midgut responses to Trypanosoma brucei challenge

Abstract Background Tsetse flies (Glossina spp.) are the prominent vector of African trypanosome parasites (Trypanosoma spp.) in sub-Saharan Africa, and Glossina pallidipes is the most widely distributed species in Kenya. This species displays strong resistance to infection by parasites, which are typically eliminated in the midgut shortly after acquisition from the mammalian host. Although extensive molecular information on immunity for the related species Glossina morsitans morsitans exists, similar information is scarce for G. pallidipes. Methods To determine temporal transcriptional responses of G. pallidipes to Trypanosoma brucei brucei challenge, we conducted Illumina based RNA-seq on midgut organ and carcass from teneral females G. pallidipes at 24 and 48 h post-challenge (hpc) with T. b. brucei relative to their respective controls that received normal blood meals (without the parasite). We used a suite of bioinformatics tools to determine differentially expressed and enriched transcripts between and among tissues, and to identify expanded transcripts in G. pallidipes relative to their orthologs G. m. morsitans. Results Midgut transcripts induced at 24 hpc encoded proteins were associated with lipid remodelling, proteolysis, collagen metabolism, apoptosis, and cell growth. Midgut transcripts induced at 48 hpc encoded proteins linked to embryonic growth and development, serine endopeptidases and proteosomal degradation of the target protein, mRNA translation and neuronal development. Temporal expression of immune responsive transcripts at 48 relative to 24 hpc was pronounced, indicative of a gradual induction of host immune responses the following challenge. We also searched for G. m. morsitans orthologous groups that may have experienced expansions in the G. pallidipes genome. We identified ten expanded groups in G. pallidipes with putative immunity-related functions, which may play a role in the higher refractoriness exhibited by this species. Conclusions There appears to be a lack of strong immune responses elicited by gut epithelia of teneral adults. This in combination with a compromised peritrophic matrix at this stage during the initial phase of T. b. brucei challenge may facilitate the increased parasite infection establishment noted in teneral flies relative to older adults. Although teneral flies are more susceptible than older adults, the majority of tenerals are still able to eliminate parasite infections. Hence, robust responses elicited at a later time point, such as 72 hpc, may clear parasite infections from the majority of flies. The expanded G. m. morsitans orthologous groups in G. pallidipes may also be functionally associated with the enhanced refractoriness to trypanosome infections reported in G. pallidipes relative to G. m. morsitans

Unsupervised classification of remotely sensed images using Gaussian mixture models and particle swarm optimization

Gaussian mixture models (GMM) are widely used for un-supervised classification applications in remote sensing. Expectation-Maximization (EM) is the standard algorithm employed to estimate the parameters of these models. However, such iterative optimization methods can easily get trapped into local maxima. Researchers use population-based stochastic search algorithms to obtain better estimates. We present a novel particle swarm optimization-based algorithm for maximum likelihood estimation of Gaussian mixture models. The proposed approach provides solutions for important problems in effective application of population-based algorithms to the clustering problem. We present a new parametrization for arbitrary covariance matrices that allows independent updating of individual parameters during the search process. We also describe an optimization formulation for identifying the correspondence relations between different parameter orderings of candidate solutions. Experiments on a hyperspectral image show better clustering results compared to the commonly used EM algorithm for estimating GMMs. © 2010 IEEE

Detection of compound structures using a gaussian mixture model with spectral and spatial constraints

Increasing spectral and spatial resolution of new-generation remotely sensed images necessitate the joint use of both types of information for detection and classification tasks. This paper describes a new approach for detecting heterogeneous compound structures such as different types of residential, agricultural, commercial, and industrial areas that are comprised of spatial arrangements of primitive objects such as buildings, roads, and trees. The proposed approach uses Gaussian mixture models (GMMs), in which the individual Gaussian components model the spectral and shape characteristics of the individual primitives and an associated layout model is used to model their spatial arrangements. We propose a novel expectation-maximization (EM) algorithm that solves the detection problem using constrained optimization. The input is an example structure of interest that is used to estimate a reference GMM and construct spectral and spatial constraints. Then, the EM algorithm fits a new GMM to the target image data so that the pixels with high likelihoods of being similar to the Gaussian object models while satisfying the spatial layout constraints are identified without any requirement for region segmentation. Experiments using WorldView-2 images show that the proposed method can detect high-level structures that cannot be modeled using traditional techniques. © 1980-2012 IEEE

Treatment trends for muscle-invasive bladder cancer in Germany from 2006 to 2019

Purpose: To examine national treatment trends of muscle-invasive bladder cancer (MIBC) in Germany with a special focus on radical cystectomy (RC). Patients and methods: Population-based data were derived from the nationwide hospital billing database of the German Federal Statistical Office and institution-related information from the reimbursement.INFO tool based on hospitals’ quality reports from 2006 to 2019. Additionally, we used the German National Center for Cancer Registry data to analyze all cases of bladder cancer with stage ≥ T2 who received RC, chemotherapy, radiation therapy or a combination from 2006 to 2017. Results: The annual number of RC cases in Germany increased by 28% from 5627 cases in 2006 to 7292 cases in 2019 (p = 0.001). The proportion of patients undergoing RC remained constant at about 75% in all age groups between 2006 and 2017 (p = 0.3). Relative to all performed RC, the proportion of patients > 75 years increased from 25% in 2006 to 38% in 2019 (p = 0.03). The proportion of patients receiving a combination of RC and chemotherapy increased from 9% in 2006 to 13% in 2017 (p = 0.005). In 2006, 8 of 299 urology departments (2.7%) performed more than 50 RCs per year, which increased to 17 of 360 (4.7%) in 2019. In 2019, 107 departments (29%) performed 25–49 RCs and 236 (66%) departments performed < 25 RCs. Conclusion: In Germany, three out of four patients with MIBC receive RC and the proportion of patients > 75 years is increasing. The combination of surgery and chemotherapy is increasingly used. With overall increasing case numbers, there is a slight tendency towards centralization.Peer Reviewe

Heimdallr 1 : A system design for the next generation of IoTs

In today’s wired and interconnected world, a sheer number of devices are now able to be connected to the internet and expose the data generated by user inputs or the devices’ built-in sensors. These growing numbers of internet of things (IoT) devices are called smart and they range from mobile phones, smart televisions, IP cameras, household and industrial appliances, to Wi-Fi thermostats and thermometers. The reason for the avalanche of IoT devices is their convenience and remote accessibility over the traditional versions. However, as with other technological breakthroughs, IoT have a major issue regarding the security of access and control of the data generated and hence privacy. To address these issues, we propose in this paper a system based approach: the system consists of two parts to monitor users’ IoTs. The first aspect of this system is a firewall monitoring and controlling the incoming and outgoing traffic to and from the IoT devices which are connected to the internet via a new generation of routers called Heimdallr. The second aspect is to store locally in this router the user’s IoT related data and allow a secure interaction by the user with the data and the IoTs. A third concept introduced in the system to ensure that any updates to the IoT software is verified and certified by a central not-for-profit organization. Heimdallr would not allow any updates to the software to be made unless the update has been certified by this certification agency. The certification agency has a role similar to CSA [1] or UL [2] organizations which provide testing, inspection and certification service and are involved in setting standards. It is worth pointing out that currently in the software domain, all this is done by the for profit corporation without any public oversight. The only beacon is the open source community where dedicated developers donate their time, talent and energy to produce open source sdedicated developers donate their time, talent and energy to produce open source software which is often free and the source code is accessible to anyone to investigate and verify their algorithms and functions.oftware which is often free and the source code is accessible to anyone to investigate and verify their algorithms and functions