Plant health and food security,linking science,economics, policy and industry

Protecting plant resources from harmful organisms that can spread internationally is a major challenge for plant protection organisations. Natural scientists and economists have methods that contribute to informing and supporting government decision makers in plant health authorities, who also need to account for stakeholders’ views when developing policy and regulations to mitigate plant pest risks. Increasingly plant protection authorities seek to develop integrated decision making through economists and scientists working within an interdisciplinary framework. In this special section of Food Security we introduce a series of papers presented at an international conference that brought together natural scientists, economists, industry representatives and plant health policy makers to report the state of the art and explore the direction and future research needs for such interdisciplinary working to deliver rational plant protection policy and improved food security for the 21st Century. The collection of papers combine contributions from leading academics and influential policy makers and provides cohesive international perspectives on the use of science and economics, as well as their integration, to progress the development of integrated multi-disciplinary plant health policy making around the world. Using a modified version of the world café method during a conference workshop activity, participants identified greater international co-operation as a key mechanism that would reduce international plant health risks. Specifically, co-operation over analysis among stakeholders and along supply chains were seen as key issues.     

Discrediting in a Message Board Forum: The Effects of Social Support and Attacks on Expertise and Trustworthiness

Given the prevalence of online media today, credibility continues to be a popular subject of empirical research. However, studies examining the effects of discrediting strategies are rare. This issue is significant given the popularity of online media and the ease of such sources to spread misinformation. Therefore, the present study examines the effects of attacking the expertise and trustworthiness of a proponent of a major social issue. Results showed that support as well specific combinations of discrediting attack strategies significantly reduced message board readers' perceptions of the proponent's credibility. In addition, attacks on either the proponent's expertise or trustworthiness resulted in a reduced likelihood of readers taking action with respect to the issue.     

Modeling and decoding motor cortical activity using a switching Kalman filter

We present a switching Kalman filter model for the real-time inference of hand kinematics from a population of motor cortical neurons. Firing rates are modeled as a Gaussian mixture where the mean of each Gaussian component is a linear function of hand kinematics. A "hidden state" models the probability of each mixture component and evolves over time in a Markov chain. The model generalizes previous encoding and decoding methods, addresses the non-Gaussian nature of firing rates, and can cope with crudely sorted neural data common in on-line prosthetic applications.     

Volatiles Retention in the Drying of Skin Forming Materials PART 2: Natural Materials

ABSTRACT

The retention of ethanol as a simulated flavour was determined by drying single droplets in a horizontal wind tunnel, with fructose, reconstituted skim milk or coffee as the flavour encapaulant. Droplet temperature histories, ethanol content, and crust structure were evaluated for each encapsulant. No enhancement of volatile retention was obtained with the fructose eolutions irrespective of initial concentration, air velocity, or air temperature. Enhancement of the volatiles retention with the coffee and skim milk solutions correlated with an increase in initial solide concentration. resulting from selective diffusion phenomena and the formation of a resistant skin. In both cases air velocity had no significant effect upon volatiles retention. Skin forming materials with similar characteristics would be advantageous for flavour retention.     

MECHANISMS OF DRYING OF SKIN-FORMING MATERIALS.III. DROPLETS OF NATURAL PRODUCTS.

ABSTRACT

Drying studies were carried out on single droplets suspended from a rotating nozzle in a horizontal wind tunnel. Droplets were of solution of a third type of skin-forming material, namely the natural products skim milk or fructose. Droplet weight and temperature were measured during the drying process. Dried crusts were recovered and examined by Scanning Electron Microscopy.

With this type of material a skin first forms at any drying condition on the surface of the droplet at a cerlain stage of drying. A crust subsequently forms beneath the skin. The final dried panicle retains the structure and properties of the original powder, unless the material is dried at very high temperatures. e.g. >300 °C. which result in burning.

An increase in air temperature resulted in the formation of a smoother skin offering a higher resistance to vapour diffusion. At temperatures over 100 °C droplets exhibited puffing or ballooning phenomena; i.e. they inflated and deflated many times before forming the final dried particles.     

Prior learning and Gibbs reaction-diffusion

This article addresses two important themes in early visual computation: it presents a novel theory for learning the universal statistics of natural images, and, it proposes a general framework of designing reaction-diffusion equations for image processing. We studied the statistics of natural images including the scale invariant properties, then generic prior models were learned to duplicate the observed statistics, based on minimax entropy theory. The resulting Gibbs distributions have potentials of the form U(I; Λ, S)=Σ_α=1^kΣ_x,yλ ^(α)((F^(α)*I)(x,y)) with S={F⁽¹⁾ , F⁽²⁾,...,F^(K)} being a set of filters and Λ={λ⁽¹⁾(),λ⁽²⁾(),...,λ ^(K)()} the potential functions. The learned Gibbs distributions confirm and improve the form of existing prior models such as line-process, but, in contrast to all previous models, inverted potentials were found to be necessary. We find that the partial differential equations given by gradient descent on U(I; Λ, S) are essentially reaction-diffusion equations, where the usual energy terms produce anisotropic diffusion, while the inverted energy terms produce reaction associated with pattern formation, enhancing preferred image features. We illustrate how these models can be used for texture pattern rendering, denoising, image enhancement, and clutter removal by careful choice of both prior and data models of this type, incorporating the appropriate features     

Lactate and malate dehydrogenase and alpha-esterases in oligospermia

Lactate dehydrogenase (LDH), malate dehydrogenase, and alpha-esterase were studied electrophoretically in a total of 99 semen samples obtained from normal, vasectomized, oligospermic, and infertile males. The enzymatic patterns were compared with total sperm count and percentage sperm motility. Lactate dehydrogenase X was absent in semen samples from oligospermic as well as vasectomized males. An extra LDH band (between the second and third LDH bands) was detectable in samples which had a low sperm count but higher motility (80 to 90%). This extra band was absent in samples with higher sperm count regardless of the level of percentage motility, suggesting that the extra band possibly may be related to motility factors of low sperm count but not normal sperm count. The fastest moving alpha-esterase bands were absent in samples from oligospermic or vasectomized males. These bands were also absent in samples from infertile patients having a very low sperm count. It is not clear whether the fast-moving esterase bands are related to sperm count or possible differences in hormonal levels of individuals with low or zero sperm count samples. The patterns of malate dehydrogenase did not differ in individuals with zero, low, or normal sperm count.