The tuatara genome reveals ancient features of amniote evolution.

The tuatara (Sphenodon punctatus)-the only living member of the reptilian order Rhynchocephalia (Sphenodontia), once widespread across Gondwana1,2-is an iconic species that is endemic to New Zealand2,3. A key link to the now-extinct stem reptiles (from which dinosaurs, modern reptiles, birds and mammals evolved), the tuatara provides key insights into the ancestral amniotes2,4. Here we analyse the genome of the tuatara, which-at approximately 5 Gb-is among the largest of the vertebrate genomes yet assembled. Our analyses of this genome, along with comparisons with other vertebrate genomes, reinforce the uniqueness of the tuatara. Phylogenetic analyses indicate that the tuatara lineage diverged from that of snakes and lizards around 250 million years ago. This lineage also shows moderate rates of molecular evolution, with instances of punctuated evolution. Our genome sequence analysis identifies expansions of proteins, non-protein-coding RNA families and repeat elements, the latter of which show an amalgam of reptilian and mammalian features. The sequencing of the tuatara genome provides a valuable resource for deep comparative analyses of tetrapods, as well as for tuatara biology and conservation. Our study also provides important insights into both the technical challenges and the cultural obligations that are associated with genome sequencing.

Publisher Correction: The tuatara genome reveals ancient features of amniote evolution.

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Using CHROMagar™ STEC medium exclusively does not recover all clinically relevant Shiga toxin-producing Escherichia coli in Aotearoa, New Zealand.

Diagnostic laboratories in Aotearoa, New Zealand (NZ) refer cultures from faecal samples positive for Shiga toxin genes to the national Enteric Reference Laboratory for isolation of Shiga toxin-producing Escherichia coli (STEC) for epidemiological typing. As there was variation in the culture media being referred, a panel of 75 clinical isolates of STEC, representing 28 different serotypes, was used to assess six commercially available media and provide guidance to clinical laboratories. Recommendations were subsequently tested for a 3-month period, where STEC isolations and confirmations were assessed by whole genome sequencing analysis against the culture media referred. CHROMagar™ STEC (CH-STEC; CHROMagar Microbiology, Paris, France) or CH-STEC plus cefixime-tellurite sorbitol MacConkey agar was confirmed inferior to CH-STEC plus blood agar with vancomycin, cefsulodin, and cefixime (BVCC). The former resulted in fewer STEC types (n = 18) being confirmed compared to those from a combination of CH-STEC and BVCC (n = 42). A significant (P < .05) association with an STEC's ability to grow on CH-STEC and the presence of the ter gene cluster, and eae was observed. Culturing screen positive STEC samples onto both CH-STEC and BVCC ensures a consistently higher recovery of STEC from all clinical samples in NZ than CH-STEC alone.

Using eye-tracking to understand relations between visual attention and language in children's spatial skills.

Relations between children's spatial language and spatial skills raise questions regarding whether the effects are unique to language or reflect non-linguistic processes. Different paradigms provided mixed evidence: experimenter-provided language supports spatial performance more than visual cues; however, children's non-verbal attention predicts their spatial performance more than their language production. The current study used eye-tracking during spatial recall to compare effects of language versus visual cues. Four- to five-year-old children completed two tasks requiring memory for the location of a toy under one of four cups in an array of cups and landmarks after a 5 s delay and array rotation. Children first completed the baseline task with non-specific cues, followed by the cue-manipulation task with either language, visual, or non-specific cues provided by the experimenter. As in prior studies, language cues were most effective in facilitating recall. Children's visual attention was directed by both language and visual cues to support their recall. However, visual attention only partially mediated the effects of language: language supported recall above and beyond directing visual attention. These results indicate that visual attention supports spatial recall, but language has additional unique influences. This may result from language providing a more coherent or redundant code to visual information, or due to the pragmatic nature of language cueing relevance in ways visual cues do not. Additionally, differences across conditions may reflect more benefit from endogenous versus exogenous attentional control. Through using eye-tracking, this research provided new insights into processes by which language and visual attention influence children's spatial cognition.

Speech and Gesture Production Provide Unique Insights Into Young Children's Spatial Reasoning.

This study took a novel approach to understanding the role of language in spatial development by combining approaches from spatial language and gesture research. It analyzed forty-three 4.5- to 6-year-old's speech and gesture production during explanations of reasoning behind performance on Spatial Analogies and Children's Mental Transformation Tasks. Results showed that speech and gesture relevant for solving the trials (disambiguating correct choices) predicted spatial performance when controlling for age, gender, and spatial words and gestures produced. Children performed the spatial tasks well if they produced relevant information either verbally through speech or nonverbally through gesture. These results highlight the importance of not only focusing on concepts children can reference but also on how such concepts are used in spatial tasks.

Patient experiences of nurse-facilitated advance care planning in a general practice setting: a qualitative study.

BACKGROUND: Advance care planning (ACP) can offer benefits to patients and their families, especially when delivered in outpatient settings, but uptake remains low. Common barriers for health professionals include a perceived lack of time and adequate training, experience, and confidence in conducting ACP. Patient-reported barriers include a lack of awareness of ACP or discomfort initiating or engaging in discussions about end-of-life. METHODS: We aimed to explore patients' perspectives of an ACP intervention designed to address common barriers to uptake in the general practice setting. We provided training and support to doctors and general practice nurses (GPNs) to initiate and lead ACP discussions at their respective practices (2014 to 2015). Following the intervention, we conducted interviews with patients to explore their experience of engaging in ACP in the general practice setting. Thematic analysis was used to inductively code transcripts and identify key themes from semi-structured interviews with patients. RESULTS: Six major themes relating to patient experiences of GPN-facilitated ACP were identified: working through ideas, therapeutic relationship with nurses, significance of making wishes known, protecting family from burden, autonomy in decision-making, and challenges of family communication. The patients valued the opportunity to speak about issues that are important to them with the GPN who they found to be compassionate and caring. The patients felt that ACP would lead to significant benefits not only to themselves but also for their family. Despite encouragement to involve other family members, most patients attended the ACP discussions alone or as a couple; many did not see the relevance of their family being involved in the discussions. Some patients felt uncomfortable or reluctant in communicating the results of their discussion with their family. CONCLUSIONS: With adequate training and support, GPNs are able to initiate and facilitate ACP conversations with patients. Their involvement in ACP can have significant benefits for patients. Psychosocial and relational elements of care are critical to patient satisfaction. Our findings show that some patients may feel uncomfortable or reluctant to communicate the results of their ACP discussions with their family. A future larger study is required to verify the findings of this pilot study.

Agreement between diagnoses of otitis media by audiologists and otolaryngologists in Aboriginal Australian children.

OBJECTIVES: To determine the degree of agreement of diagnoses by audiologists and otolaryngologists of otitis media (OM) in Aboriginal children. DESIGN: Cross-sectional study of agreement between diagnoses. SETTING: Study of Environment on Aboriginal Resilience and Child Health (SEARCH), a prospective cohort study of Aboriginal children attending four Aboriginal Community Controlled Health Services in New South Wales (three metropolitan, one regional) during 2008-2012. PARTICIPANTS: 1310 of 1669 SEARCH participants (78.5%; mean age, 7.0 years; SD, 4.4 years) were assessed and received a diagnosis from one of five experienced audiologists. Test results (but not case histories) were forwarded to one of three otolaryngologists for blinded independent assessment. MAIN OUTCOME MEASURES: Agreement of OM diagnoses by audiologists and otolaryngologists at ear and child levels; correctness of audiologist diagnoses (otolaryngologist diagnosis as reference). RESULTS: Paired diagnoses by audiologists and otolaryngologists were available for 863 children at the child level and 1775 ears (989 children) at the ear level. Otolaryngologists diagnosed OM in 251 children (29.1%), including 11 (1.3%) with tympanic membrane perforation, and in 396 ears (22.3%), including 12 (0.7%) with perforation. Agreement between audiologists and otolaryngologists for OM at the ear level was 92.2% (κ = 0.78; 95% CI, 0.74-0.82), and at the child level 91.7% (κ = 0.81; 95% CI, 0.77-0.85). No otolaryngologist-diagnosed perforation was missed by audiologists. Among 1000 children triaged by an audiologist, there would be 45 false positives and 30 false negatives when compared with assessments by an otolaryngologist, with no missed perforations. CONCLUSIONS: There was substantial agreement between audiologists' and otolaryngologists' diagnoses of OM in a high prevalence population of Aboriginal children. In settings with limited access to otolaryngologists, audiologists may appropriately triage children and select those requiring specialist review.

Children's attention to task-relevant information accounts for relations between language and spatial cognition.

Children's spatial language reliably predicts their spatial skills, but the nature of this relation is a source of debate. This investigation examined whether the mechanisms accounting for such relations are specific to language use or reflect a domain-general mechanism of selective attention. Experiment 1 examined whether 4-year-olds' spatial skills were predicted by their selective attention or their adaptive language use. Children completed (a) an attention task assessing attention to task-relevant color, size, and location cues; (b) a description task assessing adaptive language use to describe scenes varying in color, size, and location; and (c) three spatial tasks. There was correspondence between the cue types that children attended to and produced across description and attention tasks. Adaptive language use was predicted by both children's attention and task-related language production, suggesting that selective attention underlies skills in using language adaptively. After controlling for age, gender, receptive vocabulary, and adaptive language use, spatial skills were predicted by children's selective attention. The attention score predicted variance in spatial performance previously accounted for by adaptive language use. Experiment 2 followed up on the attention task (Experiment 2a) and description task (Experiment 2b) from Experiment 1 to assess whether performance in the tasks related to selective attention or task-specific demands. Performance in Experiments 2a and 2b paralleled that in Experiment 1, suggesting that the effects in Experiment 1 reflected children's selective attention skills. These findings show that selective attention is a central factor supporting spatial skill development that could account for many effects previously attributed to children's language use.

Producing Spatial Words Is Not Enough: Understanding the Relation Between Language and Spatial Cognition.

Prior research has investigated the relation between children's language and spatial cognition by assessing the quantity of children's spatial word production, with limited attention to the context in which children use such words. This study tested whether 4-year-olds children's (N = 41, primarily white middle class) adaptive use of task-relevant language across contexts predicted their spatial skills. Children were presented with a spatial scene description task, four spatial tasks, and vocabulary assessments. Children's adaptive use of task-relevant language was more predictive of their spatial skills than demographic and language factors (e.g., quantity of spatial words produced). These findings identify new links between language and spatial cognition and highlight the importance of understanding the quality, not just quantity, of children's language use.

Sixteen kiwi (Apteryx spp) transcriptomes provide a wealth of genetic markers and insight into sex chromosome evolution in birds.

BACKGROUND: Kiwi represent the most basal extant avian lineage (paleognaths) and exhibit biological attributes that are unusual or extreme among living birds, such as large egg size, strong olfaction, nocturnality, flightlessness and long lifespan. Despite intense interest in their evolution and their threatened status, genomic resources for kiwi were virtually non-existent until the recent publication of a single genome. Here we present the most comprehensive kiwi transcriptomes to date, obtained via Illumina sequencing of whole blood and de novo assembly of mRNA sequences of eight individuals from each of the two rarest kiwi species, little spotted kiwi (LSK; Apteryx owenii) and rowi (A. rowi). RESULTS: Sequences obtained were orthologous with a wide diversity of functional genes despite the sequencing of a single tissue type. Individual and composite assemblies contain more than 7900 unique protein coding transcripts in each of LSK and rowi that show strong homology with chicken (Gallus gallus), including those associated with growth, development, disease resistance, reproduction and behavior. The assemblies also contain 66,909 SNPs that distinguish between LSK and rowi, 12,384 SNPs among LSK (associated with 3088 genes), and 29,313 SNPs among rowi (associated with 4953 genes). We found 3084 transcripts differentially expressed between LSK and rowi and 150 transcripts differentially expressed between the sexes. Of the latter, 83 could be mapped to chicken chromosomes with 95% syntenic with chromosome Z. CONCLUSIONS: Our study has simultaneously sequenced multiple species, sexes, and individual kiwi at thousands of genes, and thus represents a significant leap forward in genomic resources available for kiwi. The expression pattern we observed among chromosome Z related genes in kiwi is similar to that observed in ostriches and emu, suggesting a common and ancestral pattern of sex chromosome homomorphy, recombination, and gene dosage among living paleognaths. The transcriptome assemblies described here will provide a rich resource for polymorphic marker development and studies of adaptation of these highly unusual and endangered birds.

Changes in Hox genes' structure and function during the evolution of the squamate body plan.

Hox genes are central to the specification of structures along the anterior-posterior body axis, and modifications in their expression have paralleled the emergence of diversity in vertebrate body plans. Here we describe the genomic organization of Hox clusters in different reptiles and show that squamates have accumulated unusually large numbers of transposable elements at these loci, reflecting extensive genomic rearrangements of coding and non-coding regulatory regions. Comparative expression analyses between two species showing different axial skeletons, the corn snake and the whiptail lizard, revealed major alterations in Hox13 and Hox10 expression features during snake somitogenesis, in line with the expansion of both caudal and thoracic regions. Variations in both protein sequences and regulatory modalities of posterior Hox genes suggest how this genetic system has dealt with its intrinsic collinear constraint to accompany the substantial morphological radiation observed in this group.

Seasonal reproduction of male Gambusia holbrooki (eastern mosquitofish) from two Florida lakes.

Sixteen monthly collections of adult male Gambusia holbrooki (eastern mosquitofish) were obtained from two lakes in central Florida, USA. Lake Woodruff and Lake Apopka are 36 miles apart, but differ in several environmental parameters. Compared with Lake Woodruff, Lake Apopka is warmer, more shallow in sampling areas (particularly during drought conditions; approximately 15-90 cm in Lake Apopka versus 60-120 cm in Lake Woodruff), more turbid, and more heavily contaminated with nutrients and industrial and agricultural chemicals. Here, we present detailed information on seasonal reproduction patterns in mosquitofish in their native range and compare patterns between fish from the two lakes. Male mosquitofish were reproductively active from spring through fall. Spermatogenesis, which is regulated in part by 11-ketotestosterone, ceased in October, and fish stored spermatozoa through the winter for immediate fertilization of offspring in the spring. Compared with Lake Woodruff, fish from Lake Apopka tended to be larger and have longer gonopodia and greater gonado- and hepato-somatic indices (GSI and HSI). High GSI in Apopka fish correlated with greater spermatid production, but fewer mature spermatozoa and either the same or lower sperm counts and sperm viability. Taken together, these observations suggest that differentiation of spermatids to spermatozoa is disrupted in Apopka fish, leading to reductions in fertility in some months. Delivery of sperm to females could also be affected in Apopka fish, which exhibit lower prevalence of efferent duct tissue in the testes during the summer.

A comparison of structural morphometry in children and adults with persistent developmental stuttering.

This cross-sectional study aimed to differentiate earlier occurring neuroanatomical differences that may reflect core deficits in stuttering versus changes associated with a longer duration of stuttering by analysing structural morphometry in a large sample of children and adults who stutter and age-matched controls. Whole-brain T1-weighted structural scans were obtained from 166 individuals who stutter (74 children, 92 adults; ages 3-58) and 191 controls (92 children, 99 adults; ages 3-53) from eight prior studies in our laboratories. Mean size and gyrification measures were extracted using FreeSurfer software for each cortical region of interest. FreeSurfer software was also used to generate subcortical volumes for regions in the automatic subcortical segmentation. For cortical analyses, separate ANOVA analyses of size (surface area, cortical thickness) and gyrification (local gyrification index) measures were conducted to test for a main effect of diagnosis (stuttering, control) and the interaction of diagnosis-group with age-group (children, adults) across cortical regions. Cortical analyses were first conducted across a set of regions that comprise the speech network and then in a second whole-brain analysis. Next, separate ANOVA analyses of volume were conducted across subcortical regions in each hemisphere. False discovery rate corrections were applied for all analyses. Additionally, we tested for correlations between structural morphometry and stuttering severity. Analyses revealed thinner cortex in children who stutter compared with controls in several key speech-planning regions, with significant correlations between cortical thickness and stuttering severity. These differences in cortical size were not present in adults who stutter, who instead showed reduced gyrification in the right inferior frontal gyrus. Findings suggest that early cortical anomalies in key speech planning regions may be associated with stuttering onset. Persistent stuttering into adulthood may result from network-level dysfunction instead of focal differences in cortical morphometry. Adults who stutter may also have a more heterogeneous neural presentation than children who stutter due to their unique lived experiences.

Do Not Cut Off Your Tail: A Mega-Analysis of Responses to Auditory Perturbation Experiments.

PURPOSE: The practice of removing "following" responses from speech perturbation analyses is increasingly common, despite no clear evidence as to whether these responses represent a unique response type. This study aimed to determine if the distribution of responses to auditory perturbation paradigms represents a bimodal distribution, consisting of two distinct response types, or a unimodal distribution. METHOD: This mega-analysis pooled data from 22 previous studies to examine the distribution and magnitude of responses to auditory perturbations across four tasks: adaptive pitch, adaptive formant, reflexive pitch, and reflexive formant. Data included at least 150 unique participants for each task, with studies comprising younger adult, older adult, and Parkinson's disease populations. A Silverman's unimodality test followed by a smoothed bootstrap resampling technique was performed for each task to evaluate the number of modes in each distribution. Wilcoxon signed-ranks tests were also performed for each distribution to confirm significant compensation in response to the perturbation. RESULTS: Modality analyses were not significant (p > .05) for any group or task, indicating unimodal distributions. Our analyses also confirmed compensatory reflexive responses to pitch and formant perturbations across all groups, as well as adaptive responses to sustained formant perturbations. However, analyses of sustained pitch perturbations only revealed evidence of adaptation in studies with younger adults. CONCLUSION: The demonstration of a clear unimodal distribution across all tasks suggests that following responses do not represent a distinct response pattern, but rather the tail of a unimodal distribution. SUPPLEMENTAL MATERIAL: https://doi.org/10.23641/asha.24282676.

De novo sequence assembly and characterisation of a partial transcriptome for an evolutionarily distinct reptile, the tuatara (Sphenodon punctatus).

BACKGROUND: The tuatara (Sphenodon punctatus) is a species of extraordinary zoological interest, being the only surviving member of an entire order of reptiles which diverged early in amniote evolution. In addition to their unique phylogenetic placement, many aspects of tuatara biology, including temperature-dependent sex determination, cold adaptation and extreme longevity have the potential to inform studies of genome evolution and development. Despite increasing interest in the tuatara genome, genomic resources for the species are still very limited. We aimed to address this by assembling a transcriptome for tuatara from an early-stage embryo, which will provide a resource for genome annotation, molecular marker development and studies of development and adaptation in tuatara. RESULTS: We obtained 30 million paired-end 50 bp reads from an Illumina Genome Analyzer and assembled them with Velvet and Oases using a range of kmers. After removing redundancy and filtering out low quality transcripts, our transcriptome dataset contained 32911 transcripts, with an N50 of 675 and a mean length of 451 bp. Almost 50% (15965) of these transcripts could be annotated by comparison with the NCBI non-redundant (NR) protein database or the chicken, green anole and zebrafish UniGene sets. A scan of candidate genes and repetitive elements revealed genes involved in immune function, sex differentiation and temperature-sensitivity, as well as over 200 microsatellite markers. CONCLUSIONS: This dataset represents a major increase in genomic resources for the tuatara, increasing the number of annotated gene sequences from just 60 to almost 16,000. This will facilitate future research in sex determination, genome evolution, local adaptation and population genetics of tuatara, as well as inform studies on amniote evolution.

Phylogenetic analysis of ticks (Acari: Ixodida) using mitochondrial genomes and nuclear rRNA genes indicates that the genus Amblyomma is polyphyletic.

Our understanding of the phylogenetic relationships among tick lineages has been limited by the lack of resolution provided by the most commonly used phylogenetic markers. Mitochondrial genomes are increasingly used to address controversial phylogenetic relationships. To date, the complete mitochondrial genomes of eleven tick species have been sequenced; however, only three of these species are metastriate ticks, the most speciose lineage of ticks. In this study, we present the nucleotide sequences of the complete mitochondrial genomes of five more species of metastriate ticks: Amblyomma elaphense, Amblyomma fimbriatum, Amblyomma sphenodonti, Bothriocroton concolor and Bothriocroton undatum. We use complete mitochondrial genome sequences to address the phylogenetic placement of two morphologically 'primitive' species -Am. elaphense and Am. sphenodonti - with respect to the genus Amblyomma. Our analysis of these five mitochondrial genomes with the other eleven tick mitochondrial genomes, as well as analysis of nuclear rRNA genes, provides strong evidence that the genus Amblyomma is polyphyletic with the inclusion of Am. sphenodonti and Am. elaphense. A new genus or two new genera may be required to describe Am. sphenodonti and Am. elaphense. It is also possible that these two species are sisters to two established genera, Bothriocroton in the case of Am. sphenodonti, and Haemaphysalis in the case of Am. elaphense. However, other arrangements of these taxa cannot be excluded with the current data. Thus, while Am. sphenodonti and Am. elaphense do not belong in the genus Amblyomma, the phylogenetic placement of these two species cannot be resolved without more data from metastriate ticks, either greater sampling of mitochondrial genomes, or a large data set of nuclear genes.

Securing the demographic and genetic future of tuatara through assisted colonization.

Climate change poses a particular threat to species with fragmented distributions and little or no capacity to migrate. Assisted colonization, moving species into regions where they have not previously occurred, aims to establish populations where they are expected to survive as climatic envelopes shift. However, adaptation to the source environment may affect whether species successfully establish in new regions. Assisted colonization has spurred debate among conservation biologists and ecologists over whether the potential benefits to the threatened species outweigh the potential disruption to recipient communities. In our opinion, the debate has been distracted by controversial examples, rather than cases where assisted colonization may be a viable strategy. We present a strategic plan for the assisted migration of tuatara (Sphenodon punctatus), an endemic New Zealand reptile. The plan includes use of extant populations as reference points for comparisons with assisted-colonization populations with respect to demography, phenotypic plasticity, and phenology; optimization of genetic variation; research to fill knowledge gaps; consideration of host and recipient communities; and inclusion of stakeholders in the planning stage. When strategically planned and monitored, assisted colonization could meet conservation and research goals and ultimately result in the establishment of long-term sustainable populations capable of persisting during rapid changes in climate.

Comparisons of Four Diet Quality Indexes to Define Single Meal Healthfulness.

BACKGROUND: Many dietary indexes exist to evaluate nutrition quality, but few specifically assess the quality of a single meal. OBJECTIVE: Our aim was to compare 4 different diet quality indexes in their ability to assess the nutrition quality of single meals. DESIGN: This was a secondary analysis of data from the PACE (Effects of Physical Activity Calorie Expenditure) food labeling study (2015-2017). Data were collected in business cafeterias in North Carolina and included photos of lunch trays before consumption from an adult population and serving sizes of each food item. Additional nutrient analysis was conducted to compile macro- and micronutrient data for each food item, in addition to servings provided from each food group. MAIN OUTCOME MEASURES: The main outcome was individual meal nutrition quality. Data from the PACE study were used to calculate the scores of the following diet quality indexes: Healthy Eating Index 2015, Dietary Approaches to Stop Hypertension accordance score, Main Meal Quality Index, and Nutrient Rich Foods Index. STATISTICAL ANALYSIS PERFORMED: To score the meals, algorithms were created in SAS software, version 9.4, to combine individual foods and beverages into meals and calculate scores according to the individual index components. The total scores for each of the indexes were compared using Spearman correlation coefficients. RESULTS: A total of 8,070 observations or "meals" from 379 participants were scored for this study. The scores for each observation varied by index. The Spearman correlation coefficients between the indexes for the total score for all observations ranged from 0.26 to 0.68. The correlation coefficients did not change equally among the indexes when observations were excluded based on predefined criteria for what constitutes a meal. CONCLUSIONS: There is wide variability in scores of the 4 diet quality indexes analyzed in this study. In addition, the indexes show weak to moderate correlation, indicating that the appropriateness of the index will depend greatly on the study questions and objectives.

Characterisation of class II B MHC genes from a ratite bird, the little spotted kiwi (Apteryx owenii).

Major histocompatibility complex (MHC) genes are important for vertebrate immune response and typically display high levels of diversity due to balancing selection from exposure to diverse pathogens. An understanding of the structure of the MHC region and diversity among functional MHC genes is critical to understanding the evolution of the MHC and species resilience to disease exposure. In this study, we characterise the structure and diversity of class II MHC genes in little spotted kiwi Apteryx owenii, a ratite bird representing the basal avian lineage (paleognaths). Results indicate that little spotted kiwi have a more complex MHC structure than that of other non-passerine birds, with at least five class II MHC genes, three of which are expressed and likely to be functional. Levels of MHC variation among little spotted kiwi are extremely low, with 13 birds assayed having nearly identical MHC genotypes (only two genotypes containing four alleles, three of which are fixed). These results suggest that recent genetic drift due to a species-wide bottleneck of at most seven birds has overwhelmed past selection for high MHC diversity in little spotted kiwi, potentially leaving the species highly susceptible to disease.

Modelling speech motor programming and apraxia of speech in the DIVA/GODIVA neurocomputational framework.

BACKGROUND: The Directions Into Velocities of Articulators (DIVA) model and its partner, the Gradient Order DIVA (GODIVA) model, provide neurobiologically grounded, computational accounts of speech motor control and motor sequencing, with applications for the study and treatment of neurological motor speech disorders. AIMS: In this review, we provide an overview of the DIVA and GODIVA models and how they explain the interface between phonological and motor planning systems to build on previous models and provide a mechanistic accounting of apraxia of speech (AOS), a disorder of speech motor programming. MAIN CONTRIBUTION: Combined, the DIVA and GODIVA models account for both the segmental and suprasegmental features that define AOS via damage to (i) a speech sound map, hypothesized to reside in left ventral premotor cortex, (ii) a phonological content buffer hypothesized to reside in left posterior inferior frontal sulcus, and/or (iii) the axonal projections between these regions. This account is in line with a large body of behavioural work, and it unifies several prior theoretical accounts of AOS. CONCLUSIONS: The DIVA and GODIVA models provide an integrated framework for the generation and testing of both behavioural and neuroimaging hypotheses about the underlying neural mechanisms responsible for motor programming in typical speakers and in speakers with AOS.