High Performance Associative Memories and Structured Weight Dilution

Copyright SpringerThe consequences of two techniques for symmetrically diluting the weights of the standard Hopfield architecture associative memory model, trained using a non-Hebbian learning rule, are examined. This paper reports experimental investigations into the effect of dilution on factors such as: pattern stability and attractor performance. It is concluded that these networks maintain a reasonable level of performance at fairly high dilution rates

Design principles for fostering pedagogical provenance through research in technology supported learning

This paper contributes new critical and theoretical approaches that build the capacity to link research and practice in the field of educational technology. Building on a recent meta-narrative review of the problematic concepts of impact and measurability of educational technologies, we explore the case for methodological design principles that could have the effect of increasing the pedagogical provenance of research into technology supported learning. We extend our previous review by exploring how the design principles we have delineated can contribute to evidence, that increases pedagogical provenance. We also extend this work through critical reflection on how meta-narrative approaches to reviews have the potential to contribute to increased pedagogical provenance in ways that systematic reviews often fall short

Exploitation histories of pangolins and endemic pheasants on Hainan Island, China: baselines and shifting social norms

Overexploitation is a critical threat to the survival of many species. The global demand for wildlife products has attracted considerable research attention, but regional species exploitation histories are more rarely investigated. We interviewed 169 villagers living around seven terrestrial nature reserves on Hainan Island, China, with the aim of reconstructing historical patterns of hunting and consumption of local wildlife, including the globally threatened Chinese pangolin (Manis pentadactyla) and Hainan peacock-pheasant (Polyplectron katsumatae), from the mid-20th century onwards. We aimed to better understand the relationship between these past activities and current consumption patterns. Our findings suggest that eating pangolin meat was not a traditional behaviour in Hainan, with past consumption prohibited by local myths about pangolins. In contrast, local consumption of peacock-pheasant meat was a traditional activity. However, later attitudes around hunting pangolins and peacock-pheasants in Hainan were influenced by pro-hunting policies and a state-run wildlife trade from the 1960s to the 1980s. These new social norms still shape the daily lifestyles and perceptions of local people towards wildlife consumption in Hainan today. Due to these specific historical patterns of wildlife consumption, local-adapted interventions such as promoting substitute meat choices and alternative livelihoods might be effective at tackling local habits of consuming wild meat. Our study highlights the importance of understanding the local historical contexts of wildlife use for designing appropriate conservation strategies

Knowledge and attitudes about the use of pangolin scale products in Traditional Chinese Medicine (TCM) within China

1. All eight pangolin species are threatened with extinction, largely through demand for their products including scales, meat and body parts. The demand for pangolin scales has gained attention from many conservation groups due to the large volumes involved in illegal trade. Market demand in China is one of the major drivers for international illegal trade according to confiscation reports, and many conservation interventions have been attempted to reduce this demand. 2. The Traditional Chinese Medicine (TCM) community plays a key role in regulating legal trade and combating illegal trade in pangolin scales. However, this community has been largely overlooked by previous conservation interventions directed at the pangolin scale trade. There has also been little research into the involvement of the TCM community in pangolin scale trade in China. 3. To fill these knowledge gaps, we interviewed TCM doctors from 41 hospitals, shop owners/assistants from 90 TCM shops, two TCM wholesalers, and 2,168 members of the general public in Henan and Hainan provinces, China. Respondents' knowledge of and attitudes towards the pangolin scale trade were investigated using semi-structured and structured questionnaires, with a total of 2,301 respondents. 4. Our results show that TCM practitioners generally have poor awareness of the illegal nature of their behaviours and pangolin scale products involved. Awareness is particularly poor among participants at the end of the trade chain (i.e. end sellers). The public also generally lacked understanding of pangolin products in markets. 5. Results also show that 20 (71%) of 28 doctors believed that the use of pangolin scales in at least some, if not all, treatments could be substituted by other ingredients. 6. These findings suggest that raising awareness of the legality of pangolin scale products and petitioning TCM communities to use alternative substitutes for these products could constitute feasible and effective pangolin conservation interventions. 7. This study provides the first insights into the knowledge of and attitudes towards the pangolin scale trade from the perspective of TCM practitioners, and suggests that collaborating with the TCM community is necessary to combat this illegal trade

Dynamic self-referencing approach to whispering gallery mode biosensing and its application to measurement within undiluted serum

Biosensing within complex biological samples requires a sensor that can compensate for fluctuations in the signal due to changing environmental conditions and nonspecific binding events. To achieve this, we developed a novel self-referenced biosensor consisting of two almost identically sized dye-doped polystyrene microspheres placed on adjacent holes at the tip of a microstructured optical fiber (MOF). Here self-referenced biosensing is demonstrated with the detection of Neutravidin in undiluted, immunoglobulin-deprived human serum samples. The MOF allows remote excitation and collection of the whispering gallery modes (WGMs) of the microspheres while also providing a robust and easy to manipulate dip-sensing platform. By taking advantage of surface functionalization techniques, one microsphere acts as a dynamic reference, compensating for nonspecific binding events and changes in the environment (such as refractive index and temperature), while the other microsphere is functionalized to detect a specific interaction. The almost identical size allows the two spheres to have virtually identical refractive index sensitivity and surface area, while still having discernible WGM spectra. This ensures their responses to nonspecific binding and environmental changes are almost identical, whereby any specific changes, such as binding events, can be monitored via the relative movement between the two sets of WGM peaks.Tess Reynolds, Alexandre Franc, ois, Nicolas Riesen, Michelle E. Turvey, Stephen J. Nicholls, Peter Hoffmann, and Tanya M. Monr

Exploitation Histories of Pangolins and Endemic Pheasants on Hainan Island, China: Baselines and Shifting Social Norms

Overexploitation is a critical threat to the survival of many species. The global demand for wildlife products has attracted considerable research attention, but regional species exploitation histories are more rarely investigated. We interviewed 169 villagers living around seven terrestrial nature reserves on Hainan Island, China, with the aim of reconstructing historical patterns of hunting and consumption of local wildlife, including the globally threatened Chinese pangolin (Manis pentadactyla) and Hainan peacock-pheasant (Polyplectron katsumatae), from the mid-20th century onwards. We aimed to better understand the relationship between these past activities and current consumption patterns. Our findings suggest that eating pangolin meat was not a traditional behaviour in Hainan, with past consumption prohibited by local myths about pangolins. In contrast, local consumption of peacock-pheasant meat was a traditional activity. However, later attitudes around hunting pangolins and peacock-pheasants in Hainan were influenced by pro-hunting policies and a state-run wildlife trade from the 1960s to the 1980s. These new social norms still shape the daily lifestyles and perceptions of local people towards wildlife consumption in Hainan today. Due to these specific historical patterns of wildlife consumption, local-adapted interventions such as promoting substitute meat choices and alternative livelihoods might be effective at tackling local habits of consuming wild meat. Our study highlights the importance of understanding the local historical contexts of wildlife use for designing appropriate conservation strategies.</jats:p

Identification of beer spoilage microorganisms using the MALDI Biotyper platform

Published online: 9 February 2016Beer spoilage microorganisms present a major risk for the brewing industry and can lead to cost-intensive recall of contaminated products and damage to brand reputation. The applicability of molecular profiling using matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry (MALDI-TOF MS) in combination with Biotyper software was investigated for the identification of beer spoilage microorganisms from routine brewery quality control samples. Reference mass spectrum profiles for three of the most common bacterial beer spoilage microorganisms (Lactobacillus lindneri, Lactobacillus brevis and Pediococcus damnosus), four commercially available brewing yeast strains (top- and bottom-fermenting) and Dekkera/Brettanomyces bruxellensis wild yeast were established, incorporated into the Biotyper reference library and validated by successful identification after inoculation into beer. Each bacterial species could be accurately identified and distinguished from one another and from over 5600 other microorganisms present in the Biotyper database. In addition, wild yeast contaminations were rapidly detected and distinguished from top- and bottom-fermenting brewing strains. The applicability and integration of mass spectrometry profiling using the Biotyper platform into existing brewery quality assurance practices within industry were assessed by analysing routine microbiology control samples from a local brewery, where contaminating microorganisms could be reliably identified. Brewery-isolated microorganisms not present in the Biotyper database were further analysed for identification using LC-MS/MS methods. This renders the Biotyper platform a promising candidate for biological quality control testing within the brewing industry as a more rapid, high-throughput and cost-effective technology that can be tailored for the detection of brewery-specific spoilage organisms from the local environment.Michelle Elizabeth Turvey, Florian Weiland, Jon Meneses, Nick Sterenberg, Peter Hoffman

Real-Time Measurement of F-Actin Remodelling during Exocytosis Using Lifeact-EGFP Transgenic Animals

F-actin remodelling is essential for a wide variety of cell processes. It is important in exocytosis, where F-actin coats fusing exocytic granules. The purpose of these F-actin coats is unknown. They may be important in stabilizing the fused granules, they may play a contractile role and promote expulsion of granule content and finally may be important in endocytosis. To elucidate these functions of F-actin remodelling requires a reliable method to visualize F-actin dynamics in living cells. The recent development of Lifeact-EGFP transgenic animals offers such an opportunity. Here, we studied the characteristics of exocytosis in pancreatic acinar cells obtained from the Lifeact-EGFP transgenic mice. We show that the time-course of agonist-evoked exocytic events and the kinetics of each single exocytic event are the same for wild type and Lifeact-EGFP transgenic animals. We conclude that Lifeact-EGFP animals are a good model to study of exocytosis and reveal that F-actin coating is dependent on the de novo synthesis of F-actin and that development of actin polymerization occurs simultaneously in all regions of the granule. Our insights using the Lifeact-EGFP mice demonstrate that F-actin coating occurs after granule fusion and is a granule-wide event

Attentive Learning of Sequential Handwriting Movements: A Neural Network Model

Defense Advanced research Projects Agency and the Office of Naval Research (N00014-95-1-0409, N00014-92-J-1309); National Science Foundation (IRI-97-20333); National Institutes of Health (I-R29-DC02952-01)