Heart–Brain Interactions in the MR Environment: Characterization of the Ballistocardiogram in EEG Signals Collected During Simultaneous fMRI

The ballistocardiographic (BCG) artifact is linked to cardiac activity and occurs in electroencephalographic (EEG) recordings acquired inside the magnetic resonance (MR) environment. Its variability in terms of amplitude, waveform shape and spatial distribution over subject’s scalp makes its attenuation a challenging task. In this study, we aimed to provide a detailed characterization of the BCG properties, including its temporal dependency on cardiac events and its spatio-temporal dynamics. To this end, we used high-density EEG data acquired during simultaneous functional MR imaging in six healthy volunteers. First, we investigated the relationship between cardiac activity and BCG occurrences in the EEG recordings. We observed large variability in the delay between ECG and subsequent BCG events (ECG–BCG delay) across subjects and non-negligible epoch-by-epoch variations at the single subject level. The inspection of spatial–temporal variations revealed a prominent non-stationarity of the BCG signal. We identified five main BCG waves, which were common across subjects. Principal component analysis revealed two spatially distinct patterns to explain most of the variance (85% in total). These components are possibly related to head rotation and pulse-driven scalp expansion, respectively. Our results may inspire the development of novel, more effective methods for the removal of the BCG, capable of isolating and attenuating artifact occurrences while preserving true neuronal activity.     

Description of a new species Physaloptera goytaca n. sp. (Nematoda,Physalopteridae) from Cerradomys goytaca Tavares,Pessôa & Gonçalves, 2011 (Rodentia,Cricetidae) from Brazil

Parasitology Research - Nematodes of the genus Physaloptera are common in rodents, including in species of the Family Cricetidae. There is no report of nematodes parasitizing Cerradomys goytaca, so...     

The ethics of relationality in implementation and evaluation research in global health: reflections from the Dream-A-World program in Kingston,Jamaica

Background

Despite recent developments aimed at creating international guidelines for ethical global health research, critical disconnections remain between how global health research is conducted in the field and the institutional ethics frameworks intended to guide research practice.

Discussion

In this paper we attempt to map out the ethical tensions likely to arise in global health fieldwork as researchers negotiate the challenges of balancing ethics committees’ rules and bureaucracies with actual fieldwork processes in local contexts. Drawing from our research experiences with an implementation and evaluation project in Jamaica, we argue that ethical research is produced through negotiated spaces and reflexivity practices that are centred on relationships between researchers and study participants and which critically examine issues of positionality and power that emerge at multiple levels. In doing so, we position ethical research practice in global health as a dialectical movement between the spoken and unspoken, or, more generally, between operationalized rules and the embodied relational understanding of persons.

Summary

Global health research ethics should be premised not upon passive accordance with existing guidelines on ethical conduct, but on tactile modes of knowing that rely upon being engaged with, and responsive to, research participants. Rather than focusing on the operationalization of ethical practice through forms and procedures, it is crucial that researchers recognize that each ethical dilemma encountered during fieldwork is unique and rooted in social contexts, interpersonal relationships, and personal narratives.

     

Interaction Behaviors of Bilingual Parents With Their Young Children With Autism Spectrum Disorder

Given concerns that bilingual exposure might confuse children with disabilities—including autism spectrum disorder (ASD)—bilingual parents may restrict exposure to one language, often the community-dominant language. We investigated a potential consequence of this decision; the possibility that non-native language use might influence parental communicative behaviors during interaction with the child. We recruited 39 parent–child dyads, each with a young child with ASD (mostly boys) and parent/carer (mostly mothers). Parents were either monolingual speakers of community-dominant English (n = 20) or bilingual with English as the second language (n = 19). We confirmed our assumption that the latter group would have significantly poorer non-native English language via standardized assessment of expressive vocabulary, and ensured children were matched on age, ASD symptoms, and developmental level. We sampled parent–child interaction—including in each of bilinguals’ native and non-native languages—and coded parents’ amount and complexity of speech, communicative synchrony, and imitations and expansions of their child’s speech. Few differences presented across bilingual parents’ native versus non-native language samples, but this group showed reduced synchrony and use of expansions compared to monolinguals. Further, bilinguals’ English-language knowledge was associated with self-reported comfort using this language and with two coded interaction measures. These empirical data only partially support qualitative accounts that non-native language use may influence bilingual parents’ interaction behaviors with their young children. With growing rates of ASD diagnosis and increasing cultural/linguistic diversity around the world, further dedicated clinical and experimental attention to this issue is clearly warranted.     

National Trends in Cholecystectomy and Endoscopic Retrograde Cholangiopancreatography During Index Hospitalization for Mild Gallstone Pancreatitis

World Journal of Surgery - Guidelines call for cholecystectomy during the index hospitalization for patients with gallstone pancreatitis. Therefore, the study sought to determine the trends for...