34 research outputs found

    Learnability Shapes Typology: The Case of the Midpoint Pathology

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    The midpoint pathology (in the sense of Kager 2012) characterizes a type of unattested stress system in which the stressable window contracts to a single word-internal syllable in some words, but not others. Kager (2012) shows that the pathology is a prediction of analyses employing contextual lapse constraints (e.g. *ExtLapseR; no 000 strings at the right edge) and argues that the only way to avoid it is to eliminate these constraints from Con. This article explores an alternative: that systems exhibiting the midpoint pathology are unattested not because the constraints that would generate them are absent from Con, but because they are difficult to learn. This study belongs to a growing body of work exploring the idea that phonological typology is shaped by considerations of learnability.

    An Identity Preference in Ngbaka Vowels

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    In a large Ngbaka dictionary (Henrix et al. 2015), segmental identity between vowels is systematically overrepresented: cases of identity like [kɔkɔ] 'to cover oneself' and [ɓɛnɛ] 'to consult an oracle' occur significantly more often than predicted by the frequencies of the individual vowels alone. I show that the best-fit statistical model of the lexical data includes a predictor for identity: non-identical vowels are dispreferred. The implication of this finding is that the phonological grammar must be able to reference identity directly (following MacEachern 1999, Coetzee & Pater 2008, Gallagher & Coon 2009, Gallagher 2013, 2014, a.o.)

    A cyclic factorial typology of Pama-Nyungan stress

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    I investigate the nature of accentual faithfulness constraints and their rankings relative to markedness constraints, starting from an analysis of stress in 23 Pama-Nyungan (PN) and neighboring Australian aboriginal languages (e.g. Pintupi, Diyari, Warlpiri). In many of these systems, unsuffixed forms are stressed identically, but suffixed forms differ according to the type of paradigmatic uniformity effect observed. The proposed account differs from prior work (e.g. Crowhurst 1994, Kager 1997, Kenstowicz 1998) as it does not appeal to feet and uses directional base-derivative (BD) identity constraints (Benua 1997) to model cyclic effects. Predictions of the constraint set are explored through a factorial typology. To constrain the typology's predictions, I introduce the visibility hypothesis: constraints backed by positive evidence from frequent forms dominate constraints that lack such evidence. Integrating the visibility hypothesis into the factorial typology results in accurately restrictive predictions for the typology of stress-morphology interactions

    Segmental Blocking in Dissimilation: An Argument for Co-Occurrence Constraints

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    Most contemporary work assumes that dissimilation is motivated by featural co-occurrence constraints: a process that maps /X...X/ to [X...Y] (for example) is explained by positing a ban on co-occurring [X]s (e.g. Alderete 1997, Suzuki 1998; though cf. Bennett 2015). I show how this approach can be extended to analyze the typology of segmental blocking effects in long-distance consonant dissimilation, and provide evidence from lexical statistics in support of the analysis. Preliminary results indicate that the proposed analysis makes more accurately restrictive predictions than available alternatives

    Intestinal schistosomiasis in Uganda at high altitude (>1400 m): malacological and epidemiological surveys on Mount Elgon and in Fort Portal crater lakes reveal extra preventive chemotherapy needs

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    Background Intestinal schistosomiasis is of public health importance in Uganda but communities living above 1400 m are not targeted for control as natural transmission is thought unlikely. To assess altitudinal boundaries and at-risk populations, conjoint malacological and epidemiological surveys were undertaken on Mount Elgon (1139 m–3937 m), in Fort Portal crater lakes and in the Rwenzori Mountains (1123 m–4050 m). Methods Seventy freshwater habitats [Mount Elgon (37), Fort Portal crater lakes (23), Rwenzori Mountains (8) and Lake Albert (2)] were inspected for Biomphalaria species. Water temperature, pH and conductivity were recorded. A parasitological examination of 756 schoolchildren [Mount Elgon (300), Fort Portal crater lakes (456)] by faecal microscopy of duplicate Kato-Katz smears from two consecutive stool samples was bolstered by antigen (urine-CCA dipstick) and antibody (SEA-ELISA) diagnostic assays. Results Biomphalaria spp. was found up to 1951 m on Mount Elgon and 1567 m in the Fort Portal crater lakes. Although no snail from Mount Elgon shed cercariae, molecular analysis judged 7.1% of snails sampled at altitudes above 1400 m as having DNA of Schistosoma mansoni; in Fort Portal crater lakes three snails shed schistosome cercariae. Prevalence of intestinal schistosomiasis as measured in schoolchildren by Kato-Katz (Mount Elgon = 5.3% v. Fort Portal crater lakes = 10.7%), CCA urine-dipsticks (18.3% v. 34.4%) and SEA-ELISA (42.3% v. 63.7%) showed negative associations with increasing altitude with some evidence of infection up to 2000 m. Conclusions Contrary to expectations, these surveys clearly show that natural transmission of intestinal schistosomiasis occurs above 1400 m, possibly extending up to 2000 m. Using spatial epidemiological predictions, this now places some extra six million people at-risk, denoting an expansion of preventive chemotherapy needs in Uganda

    Concussion, Microvascular Injury, and Early Tauopathy in Young Athletes After Impact Head Injury and an Impact Concussion Mouse Model

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    The mechanisms underpinning concussion, traumatic brain injury, and chronic traumatic encephalopathy, and the relationships between these disorders, are poorly understood. We examined post-mortem brains from teenage athletes in the acute-subacute period after mild closed-head impact injury and found astrocytosis, myelinated axonopathy, microvascular injury, perivascular neuroinflammation, and phosphorylated tau protein pathology. To investigate causal mechanisms, we developed a mouse model of lateral closed-head impact injury that uses momentum transfer to induce traumatic head acceleration. Unanaesthetized mice subjected to unilateral impact exhibited abrupt onset, transient course, and rapid resolution of a concussion-like syndrome characterized by altered arousal, contralateral hemiparesis, truncal ataxia, locomotor and balance impairments, and neurobehavioural deficits. Experimental impact injury was associated with axonopathy, blood-brain barrier disruption, astrocytosis, microgliosis (with activation of triggering receptor expressed on myeloid cells, TREM2), monocyte infiltration, and phosphorylated tauopathy in cerebral cortex ipsilateral and subjacent to impact. Phosphorylated tauopathy was detected in ipsilateral axons by 24 h, bilateral axons and soma by 2 weeks, and distant cortex bilaterally at 5.5 months post-injury. Impact pathologies co-localized with serum albumin extravasation in the brain that was diagnostically detectable in living mice by dynamic contrast-enhanced MRI. These pathologies were also accompanied by early, persistent, and bilateral impairment in axonal conduction velocity in the hippocampus and defective long-term potentiation of synaptic neurotransmission in the medial prefrontal cortex, brain regions distant from acute brain injury. Surprisingly, acute neurobehavioural deficits at the time of injury did not correlate with blood-brain barrier disruption, microgliosis, neuroinflammation, phosphorylated tauopathy, or electrophysiological dysfunction. Furthermore, concussion-like deficits were observed after impact injury, but not after blast exposure under experimental conditions matched for head kinematics. Computational modelling showed that impact injury generated focal point loading on the head and seven-fold greater peak shear stress in the brain compared to blast exposure. Moreover, intracerebral shear stress peaked before onset of gross head motion. By comparison, blast induced distributed force loading on the head and diffuse, lower magnitude shear stress in the brain. We conclude that force loading mechanics at the time of injury shape acute neurobehavioural responses, structural brain damage, and neuropathological sequelae triggered by neurotrauma. These results indicate that closed-head impact injuries, independent of concussive signs, can induce traumatic brain injury as well as early pathologies and functional sequelae associated with chronic traumatic encephalopathy. These results also shed light on the origins of concussion and relationship to traumatic brain injury and its aftermath.awx350media15713427811001

    Post-traumatic growth enhances social identification in liver transplant patients: a longitudinal study

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    Objective: The main aim of this paper is to investigate the prediction that greater subjective identification with relevant groups and social categories (i.e. family ) can be an outcome of post-traumatic growth (PTG). To date there are no studies that have explored these relationships. Methods: A longitudinal study was conducted with a group of 100 liver transplant patients from the outpatient populations of the participating centre. Data were collected by means of a self-report questionnaire, which was completed at two different time points (T1 and T2) that were 24 months apart. PTG was assessed using the Post-Traumatic Growth Inventory, while both transplantee and family identification were assessed using group identification scales. A path model was tested, using a structural equation model (SEM) approach, to examine the reciprocal effects among family identification, transplantee identification, and PTG over time. Results: As predicted, we found that greater PTG T1 predicted both greater family identification T2 and marginally greater transplantee identification T2. However, the two identification variables did not predict PTG over time. Conclusions: The results show that family identification and transplantee identification may be outcomes of the PTG process, confirming the importance of adopting a thriving multidimensional model of adjustment to medical illness, whereby people facing adverse life events, such as transplantation, may flourish rather than deteriorate psychologically

    Continuous glucose monitoring in pregnant women with type 1 diabetes (CONCEPTT): a multicentre international randomised controlled trial.

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    BACKGROUND: Pregnant women with type 1 diabetes are a high-risk population who are recommended to strive for optimal glucose control, but neonatal outcomes attributed to maternal hyperglycaemia remain suboptimal. Our aim was to examine the effectiveness of continuous glucose monitoring (CGM) on maternal glucose control and obstetric and neonatal health outcomes. METHODS: In this multicentre, open-label, randomised controlled trial, we recruited women aged 18-40 years with type 1 diabetes for a minimum of 12 months who were receiving intensive insulin therapy. Participants were pregnant (≤13 weeks and 6 days' gestation) or planning pregnancy from 31 hospitals in Canada, England, Scotland, Spain, Italy, Ireland, and the USA. We ran two trials in parallel for pregnant participants and for participants planning pregnancy. In both trials, participants were randomly assigned to either CGM in addition to capillary glucose monitoring or capillary glucose monitoring alone. Randomisation was stratified by insulin delivery (pump or injections) and baseline glycated haemoglobin (HbA1c). The primary outcome was change in HbA1c from randomisation to 34 weeks' gestation in pregnant women and to 24 weeks or conception in women planning pregnancy, and was assessed in all randomised participants with baseline assessments. Secondary outcomes included obstetric and neonatal health outcomes, assessed with all available data without imputation. This trial is registered with ClinicalTrials.gov, number NCT01788527. FINDINGS: Between March 25, 2013, and March 22, 2016, we randomly assigned 325 women (215 pregnant, 110 planning pregnancy) to capillary glucose monitoring with CGM (108 pregnant and 53 planning pregnancy) or without (107 pregnant and 57 planning pregnancy). We found a small difference in HbA1c in pregnant women using CGM (mean difference -0·19%; 95% CI -0·34 to -0·03; p=0·0207). Pregnant CGM users spent more time in target (68% vs 61%; p=0·0034) and less time hyperglycaemic (27% vs 32%; p=0·0279) than did pregnant control participants, with comparable severe hypoglycaemia episodes (18 CGM and 21 control) and time spent hypoglycaemic (3% vs 4%; p=0·10). Neonatal health outcomes were significantly improved, with lower incidence of large for gestational age (odds ratio 0·51, 95% CI 0·28 to 0·90; p=0·0210), fewer neonatal intensive care admissions lasting more than 24 h (0·48; 0·26 to 0·86; p=0·0157), fewer incidences of neonatal hypoglycaemia (0·45; 0·22 to 0·89; p=0·0250), and 1-day shorter length of hospital stay (p=0·0091). We found no apparent benefit of CGM in women planning pregnancy. Adverse events occurred in 51 (48%) of CGM participants and 43 (40%) of control participants in the pregnancy trial, and in 12 (27%) of CGM participants and 21 (37%) of control participants in the planning pregnancy trial. Serious adverse events occurred in 13 (6%) participants in the pregnancy trial (eight [7%] CGM, five [5%] control) and in three (3%) participants in the planning pregnancy trial (two [4%] CGM and one [2%] control). The most common adverse events were skin reactions occurring in 49 (48%) of 103 CGM participants and eight (8%) of 104 control participants during pregnancy and in 23 (44%) of 52 CGM participants and five (9%) of 57 control participants in the planning pregnancy trial. The most common serious adverse events were gastrointestinal (nausea and vomiting in four participants during pregnancy and three participants planning pregnancy). INTERPRETATION: Use of CGM during pregnancy in patients with type 1 diabetes is associated with improved neonatal outcomes, which are likely to be attributed to reduced exposure to maternal hyperglycaemia. CGM should be offered to all pregnant women with type 1 diabetes using intensive insulin therapy. This study is the first to indicate potential for improvements in non-glycaemic health outcomes from CGM use. FUNDING: Juvenile Diabetes Research Foundation, Canadian Clinical Trials Network, and National Institute for Health Research

    Predicting distributional restrictions on prenasalized stops

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    Previous studies on prenasalized stops (NCs) focus mainly on issues of derivation and classification, but little is known about their distributional properties. The current study fills this gap. I present results of a survey documenting positional restrictions on NCs, and show that there are predictable and systematic constraints on their distribution. The major finding is that NCs are optimally licensed in contexts where they are perceptually distinct from plain oral and nasal stops. I provide an analysis referencing auditory factors, and show that a perceptual account explains all attested patterns
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