Language learning with interactive virtual agent scenarios and speech recognition: Lessons learned

The SPELL (Spoken Electronic Language Learning) system is a self‐access computer‐assisted language learning (CALL) package that integrates speaker‐independent continuous speech recognition technology with virtual worlds and embodied virtual agents to create an environment in which learners can converse in the target language within meaningful contextualized scenarios. In this paper we provide an overview of the functionality, architecture, and implementation of the SPELL system. We also describe four phases of usability evaluation conducted with the system and summarize the main results of these user assessments. Finally, we discuss the most significant lessons learned in the development and evaluation of the system. The paper focuses on the technological aspects of the system and its evaluation for usability and robustness, rather than its pedagogical methodology. Copyright © 2008 John Wiley & Sons, Ltd.     

Bulk tank milk antibody ELISA as a biosecurity tool for detecting dairy herds with past exposure to Mycoplasma bovis

In Australia, one of the biosecurity recommendations to help prevent the introduction of Mycoplasma bovis into a dairy herd is to use a PCR assay on bulk tank milk (BTM) samples to evaluate the M. bovis infection status of potential source herds. An alternative approach is to assess the immunological status of the herd with respect to previous exposure to M. bovis via the use of an ELISA that is commercially available for use on cattle milk and serum. The objectives of this study were to (1) evaluate factors potentially associated with variation in the ELISA BTM optical density coefficient (ODC%) in previously exposed herds, (2) evaluate the association between the proportion of cows that are ELISA positive and the BTM ELISA ODC%, (3) assess agreement between the BTM ELISA and PCR and culture, and (4) compare BTM ELISA ODC% between the “hospital” herd and the main lactating herd on the same farm. Bulk tank milk samples (n = 192) were collected from 19 dairy herds with a history of clinical M. bovis disease and from 6 control herds (herds with no known clinical cases of mycoplasmosis). For 28 of the BTM samples collected, blood was also collected from 50 lactating cows contributing to that bulk tank sample. From 1 herd, concurrent paired BTM samples were collected from the main herd and the hospital herd on 16 occasions. All BTM samples were analyzed by ELISA (Bio-X Bio K 302, Bio-X Diagnostics, Rochefort, Belgium), PCR, and culture. The BTM ELISA ODC% was associated with time since initial M. bovis outbreak and time since the start of the herd's calving period. Following an initial outbreak of M. bovis, the BTM ELISA ODC% was highest in the first 8 mo. In split- and seasonal-calving herds, significantly higher BTM ELISA ODC% results were observed 5 to 8 wk after the commencement of the calving period. A significant association was observed between the within-herd seroprevalence for the lactating herd and BTM ELISA ODC%, but within-herd seroprevalence explained little of the variation in BTM ELISA ODC%. When comparing the BTM ELISA with a multiplex probe PCR and culture followed by 16S to 23S rRNA sequencing, there was virtually no agreement above that expected by chance; prevalence-adjusted bias-adjusted kappa values were 0.22 and 0.25 for ELISA category versus PCR category and culture, respectively. Finally, the hospital herd BTM ELISA ODC% mirrored that for the main herd BTM but was significantly higher. This study demonstrates that this commercially available ELISA used on BTM samples may complement the use of BTM PCR or culture in identifying herds from which purchase of animals may pose a higher biosecurity risk for introduction of M. bovis into noninfected herds.     

Technological,Regulatory, and Ethical Aspects of In Vitro Meat: A Future Slaughter‐Free Harvest

Defined as meat cultured in a laboratory within a bioreactor under controlled artificial conditions, in vitro meat is a relatively recent area that has opened a whole universe of possibilities and opportunities for the meat sector. With improved chemical and microbial safety and varied options, in vitro meat has been proposed as a green, healthy, environmentally friendly, and nutritionally better product that is free from animal suffering and death. Cell culture and tissue culture are the most probable technologies for the development of this futuristic muscle product. However, there are many challenges in the production of a suitable product at an industrial scale under a sustainable production system and a great body of research is required to fill the gaps in our knowledge. Many materials used in the product development are novel and untested within the food industry and demand urgent regulatory and safety assessment systems capable of managing any risks associated with the development of cultured meat. The future of this product will depend on the actions of governments and regulatory agencies. This article highlights emerging biotechnological options for the development of cultured meat and suggests ways to integrate these emerging technologies into meat research. It considers the problems and possibilities of developing cultured meat, opportunities, ethical issues as well as emerging safety and regulatory issues in this area.     

Assessing ovulation detection performance in commercial dairy herds using progesterone concentrations from limited numbers of strategically collected milk samples

It is important to assess ovulation detection performance in commercial dairy herds both to investigate low reproductive performance and to enable herd managers to monitor the effectiveness of their system for detecting ovulations. A method was developed to assess ovulation detection performance that uses limited numbers of strategically collected milk samples, assesses performance over the period when herd managers are making maximal effort to detect ovulations, and when assessing proportions of ovulations detected, accounts for false positive diagnoses of estrus and for cows that have not recommenced postpartum ovulatory cycles. Milk was sampled from cows not diagnosed in estrus early in the breeding program (about d 26 in year-round calving herds and d 22 in seasonal calving herds); milk samples were also collected from cows on the day of insemination. Cows with high milk progesterone concentrations were assumed to have had undetected ovulations and false positive diagnoses of estrus, respectively. The method was successfully implemented in 161 of 167 commercial dairy herds. Positive predictive values (PPV; the proportions of ovulation diagnoses where ovulation was, in fact, imminent) were generally high in both year-round and seasonal calving herds (median values were 0.96 and 0.97, respectively), but 25% of herds had PPV <0.95. Ovulation detection sensitivities (ODS) were low in most year-round calving herds, but many seasonal calving herds had high ODS values; median ODS were 0.73 and 0.94, respectively. However, in 25% of seasonal calving herds, ODS was <0.91. These findings indicate that this method for assessing ovulation detection performance can be successfully implemented in commercial dairy herds with appropriate professional support. The wide range of ODS and the absence of correlation between ODS and PPV suggest that it is possible for managers of many commercial herds in Australia to achieve increased reproductive efficiency through increases in ODS and PPV.     

Gluten-free pasta production from banana and cassava flours with egg white protein and soy protein addition

Egg white protein and soy protein were incorporated into a banana and cassava flour blend (75:25) to produce gluten-free pasta. The objectives of study were to investigate the effects of the different protein sources on the physico-chemical properties of gluten-free pasta. The levels of protein inclusion were 0%, 5%, 10% and 15% of composite flour (w/w) for each type of protein. Pasta made from 100% durum wheat semolina was used as controls. The protein fortification affected the total starch, resistant starch and protein content of gluten-free pasta compared to semolina pasta. No significant effects of soy/egg white protein addition were found in either insoluble or soluble dietary fibre content. Cooking properties of pasta (optimum cooking time, swelling index, water adsorption index and cooking loss) and texture properties (firmness and extensibility) were affected by the level of protein addition and the type of protein. Results showed the utilisation of 25% cassava flour and protein inclusion have a promising application in gluten-free pasta production.     

Applied and Emerging Methods for Meat Tenderization: A Comparative Perspective

The tenderization process, which can be influenced by both pre‐ and post‐slaughter interventions, begins immediately after an animal's death and is followed with the disruption of the muscle structure by endogenous proteolytic systems. The post‐slaughter technological interventions like electrical stimulation, suspension methods, blade tenderization, tumbling, use of exogenous enzymes, and traditional aging are some of the methods currently employed by the meat industry for improving tenderness. Over the time, technological advancement resulted in development of several novel methods, for maximizing the tenderness, which are being projected as quick, economical, nonthermal, green, and energy‐efficient technologies. Comparison of these advanced technological methods with the current applied industrial methods is necessary to understand the feasibility and benefits of the novel technology. This review discusses the benefits and advantages of different emerging tenderization techniques such as hydrodynamic‐pressure processing, high‐pressure processing, pulsed electric field, ultrasound, SmartStretch^?, Pi‐Vac Elasto‐Pack® system, and some of the current applied methods used in the meat industry.     

Classification of compressed breast shapes for the design of equalization filters in x-ray mammography

We are developing an external filter method for equalizing the x-ray exposure in mammography. Each filter is specially designed to match the shape of the compressed breast border and to preferentially attenuate the x-ray beam in the peripheral region of the breast. To be practical, this method should require the use of only a limited number of custom built filters. It is hypothesized that this would be possible if compressed breasts can be classified into a finite number of shapes. A study was performed to determine the number of shapes. Based on the parabolic appearance of the outer borders of compressed breasts in mammograms, the borders were fit with the polynomial equations y = ax2 + bx3 and y = ax2 + bx3 + cx4. The goodness-of-fit of these equations was compared. The a,b and a,b,c coefficients were employed in a K-Means clustering procedure to classify 470 CC-view and 484 MLO-view borders into 2-10 clusters. The mean coefficients of the borders within a given cluster defined the "filter" shape, and the individual borders were translated and rotated to best match that filter shape. The average rms differences between the individual borders and the "filter" were computed as were the standard deviations of those differences. The optimally shifted and rotated borders were refit with the above polynomial equations, and plotted for visual evaluation of clustering success. Both polynomial fits were adequate with rms errors of about 2 mm for the 2-coefficient equation, and about 1 mm for the 3-coefficient equation. Although the fits to the original borders were superior for the 3-coefficient equation, the matches to the "filter" borders determined by clustering were not significantly improved. A variety of modified clustering methods were developed and utilized, but none produced major improvements in clustering. Results indicate that 3 or 4 filter shapes may be adequate for each mammographic projection (CC- and MLO-view). To account for the wide variations in exposures observed at the peripheral regions of breasts classified to be of a particular shape, it may be necessary to employ different filters for thin, medium and thick breasts. Even with this added requirement, it should be possible to use a small number of filters as desired.     

SULFUR CAPTURE DURING PARTIAL COAL COMBUSTION

A coal-water slurry is an econonical substitute for premium liquid fuels, but the amount of sulfur in coal is usually higher than in petroleum liquids. Lime has been used to capture sulfur in fluidized coal combustion as CaSO₄, but the latter decomposes above 1273 K. We report here on the possible capture of sulfur in the ash as CaS, which has higher thermal stability than CaSO₄. This can be accomplished using a fuel-rich first stage in a coal-water slurry combustor, or under the conditions normally encountered in some coal gasifiers. Thermodynamic calculations and some preliminary experiments suggest that the concept is promising for effective sulfur removal and, by extension, for NO_x, control.