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This article reviews commonly accepted pedagogical practices for educating school-age English language learners, especially those whose first language is Spanish, and challenges these practices on the basis of results from psycholinguistics research that cast doubt on the assumptions underlying them. Policymakers and educators have different ideas about the best methods to teach these students; to a large extent, opinions from both sides are swayed by cultural beliefs, including the idea that children benefit more from language learning when they do not use their languages together in the same context (e.g., in a classroom setting; Petitto et al., 2001; Grosjean, 2006), or that they are delayed when they learn 2 languages simultaneously (Chiocca, 1998; Watson, 1996). But this assumption is undermined by experimental findings showing that second-language learners actually benefit when they use their first language to bootstrap learning of their target language (August, Carlo, Dressler, & Snow, 2005; Dressler, Carlo, Snow, August, & White, 2011; Proctor, August, Carlo, & Snow, 2006). Moreover, recent studies show that mixed-language settings, as compared to single-language settings, do not negatively impact learning outcomes in various academic subjects (Antón, Thierry, & Duñabeitia, 2015; Antón, Thierry, Goborov, Anasagasti, & Duñabeitia, 2016). We discuss evidence that bilinguals’ 2 language systems are frequently coactive via shared representations, and how such interconnectedness can bootstrap language learning without poorly affecting scholastic achievement. In addition, we propose research-based alternatives to common pedagogical practices that would exploit similarities between vocabulary in the first and second language.

The spread of SARS-CoV-2, which causes the disease COVID-19, is difficult to control as some positive individuals, capable of transmitting the disease, can be asymptomatic. Thus, it remains critical to generate noninvasive, inexpensive COVID-19 screening systems. Two such methods include detection canines and analytical instrumentation, both of which detect volatile organic compounds associated with SARS-CoV-2. In this study, the performance of trained detection dogs is compared to a noninvasive headspace-solid phase microextraction-gas chromatography-mass spectrometry (HS-SPME-GC-MS) approach to identifying COVID-19 positive individuals. Five dogs were trained to detect the odor signature associated with COVID-19. They varied in performance, with the two highest-performing dogs averaging 88% sensitivity and 95% specificity over five double-blind tests. The three lowest-performing dogs averaged 46% sensitivity and 87% specificity. The optimized linear discriminant analysis (LDA) model, developed using HS-SPME-GC-MS, displayed a 100% true positive rate and a 100% true negative rate using leave-one-out cross-validation. However, the non-optimized LDA model displayed difficulty in categorizing animal hair-contaminated samples, while animal hair did not impact the dogs’ performance. In conclusion, the HS-SPME-GC-MS approach for noninvasive COVID-19 detection more accurately discriminated between COVID-19 positive and COVID-19 negative samples; however, dogs performed better than the computational model when non-ideal samples were presented.

Chronic wasting disease (CWD) is a fatal transmissible spongiform encephalopathy that affects both free-ranging and farmed cervid species, including mule deer, white-tailed deer, and elk ( Odocoileus hemionus, Odocoileus virginianus , and Cervus canadensis ). Due to the long incubation period and variability of clinical signs, CWD can expand and spread to new areas before they reach diagnostically detectable levels. Antemortem testing methods currently available can be difficult to obtain and to be applied to the large numbers required for adequate surveillance. However, key volatile biomarkers could be harnessed for non-invasive antemortem surveillance. Detection dogs are the most effective tool currently available for volatile detection; dogs can effectively complete wildlife surveys at rates surpassing that of humans. This study is the first to demonstrate that trained detection dogs can be used as an antemortem test for CWD. First, we trained three dogs to differentiate between CWD-positive and CWD-negative white-tailed deer faeces in a laboratory setting. Dogs spent significantly more time at the positive sample than the negative samples, suggesting that they differentiated between the positive and negative volatile signatures. We then trained the same dogs to search for CWD-positive faecal samples in a more naturalistic field setting. In the field, dogs found 8/11 CWD-positive samples and had an average false detection rate of 13%. These results suggest that dogs can be trained to differentiate CWD-positive faeces from CWD-negative faeces in both laboratory and field settings. Future studies will compare canine accuracy to other antemortem methods, as well as improved canine training methods.

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