Examining the variation in consent in general surgery

INTRODUCTION

Consent is a fundamental aspect of surgery and expectations around the consent process have changed following the Montgomery vs Lanarkshire Health Board (2015) court ruling. This study aimed to identify trends in litigation pertaining to consent, explore variation in how consent is practised among general surgeons and identify potential causes of this variation.

METHODS

This mixed-methods study examined temporal variation in litigation rates relating to consent (between 2011 and 2020), using data obtained from National Health Service (NHS) Resolutions. Semi-structured clinician interviews were then conducted to gain qualitative data regarding how general surgeons take consent, their ideologies and their outlook on the recent legal changes. The quantitative component included a questionnaire survey aiming to explore these issues with a larger population to improve the generalisability of the findings.

RESULTS

NHS Resolutions litigation data showed a significant increase in litigation pertaining to consent following the 2015 health board ruling. The interviews demonstrated considerable variation in how surgeons approach consent. This was corroborated by the survey, which illustrated considerable variation in how consent is documented when different surgeons are presented with the same case vignette.

CONCLUSION

A clear increase in litigation relating to consent was seen in the post-Montgomery era, which may be due to legal precedent being established and increased awareness of these issues. Findings from this study demonstrate variability in the information patients receive. In some cases, consent practices did not adequately meet current regulations and therefore are susceptible to potential litigation. This study identifies areas for improvement in the practice of consent.

Role of pitch in toddler looking to new and given referents in American English

This study examined how toddler looking to a discourse referent is mediated by the information status of the referent and the pitch contour of the referring expression. Eighteen-month-olds saw a short discourse of three sets of images with the proportion of looking time to a target analyzed during the final image. At test, the information status of the referent was either new or given and the referring expression was presented with one of three pitch contours (flat f0, monotonal (~H*), or bitonal (~L+H*)). In Experiment 1, toddlers looked reliably longer to a target referent when it was either new to the discourse or carried a non-flat pitch contour. In Experiment 2, the referring expression was removed to observe effects of information status alone on looking to a target referent. Toddlers looked significantly longer to a target when it was new versus given. More fine-grained time course analyses of eye movements revealed differences in the speed and duration of fixation to a target. Overall, the experiments show that discourse reference in toddlers is mediated by the presence of newness and pitch contours, even in the case of given information.

Examining the barriers faced by female surgical trainees: a qualitative study

INTRODUCTION

Today, women make up 56% of medical students, yet just 13% of surgical consultants - a number that has remained static since 2013. This qualitative study explored some of the barriers to female success in modern surgery.

METHODS

Semistructured qualitative interviews were undertaken primarily with female surgical trainees to determine the barriers they face. Male trainees and training programme directors (TPDs) were also interviewed for triangulation.

RESULTS

20 interviews were performed (16 female trainees, 3 male trainees, and 1 TPD) between October 2019 and March 2020. Family pressures and becoming a mother were significant barriers for women training in surgery - a barrier that did not apply to male trainees who were fathers, often resulting in women choosing to train less than full time (LTFT). Unfortunately LTFT training presents further obstacles for female trainees. The set-up of the national training programme in surgery provides many non-gender-specific barriers, chiefly moving hospital every 6 months causing disrupted training and long commutes, disproportionately affecting females with child care responsibilities. Sexism and discrimination are still common, both from colleagues and patients. Many participants perceived inherent differences between genders in communication and methods for coping with stress.

CONCLUSION

Greater gender equality in surgery may be achieved by changes in the structure and organisation of training to reduce the tension between the professional role and the predominantly female-led role of raising children. Better equality and diversity training and awareness at all levels in surgery may help to mitigate some of the conscious and unconscious bias that still exists.

Bridging the age gap in breast cancer: impact of omission of breast cancer surgery in older women with oestrogen receptor-positive early breast cancer on quality-of-life outcomes

BACKGROUND

Primary endocrine therapy may be an alternative treatment for less fit women with oestrogen receptor (ER)-positive breast cancer. This study compared quality-of-life (QoL) outcomes in older women treated with surgery or primary endocrine therapy.

METHODS

This was a multicentre, prospective, observational cohort study of surgery or primary endocrine therapy in women aged over 70 years with operable breast cancer. QoL was assessed using European Organisation for Research and Treatment of cancer QoL questionnaires QLQ-C30, -BR23, and -ELD14, and the EuroQol Five Dimensions 5L score at baseline, 6 weeks, and 6, 12, 18, and 24 months. Propensity score matching was used to adjust for baseline variation in health, fitness, and tumour stage.

RESULTS

The study recruited 3416 women (median age 77 (range 69-102) years) from 56 breast units. Of these, 2979 (87.2 per cent) had ER-positive breast cancer; 2354 women had surgery and 500 received primary endocrine therapy (125 were excluded from analysis due to inadequate data or non-standard therapy). Median follow-up was 52 months. The primary endocrine therapy group was older and less fit. Baseline QoL differed between the groups; the mean(s.d.) QLQ-C30 global health status score was 66.2(21.1) in patients who received primary endocrine therapy versus 77.1(17.8) among those who had surgery plus endocrine therapy. In the unmatched analysis, changes in QoL between 6 weeks and baseline were noted in several domains, but by 24 months most scores had returned to baseline levels. In the matched analysis, major surgery (mastectomy or axillary clearance) had a more pronounced adverse impact than primary endocrine therapy in several domains.

CONCLUSION

Adverse effects on QoL are seen in the first few months after surgery, but by 24 months these have largely resolved. Women considering surgery should be informed of these effects.

Questions Can Answer Questions About Mechanisms of Preschoolers' Selective Word Learning

This study examined how inferences about epistemic competence and generalized labeling errors influence children's selective word learning. Three- to 4-year-olds (N = 128) learned words from informants who asked questions about objects, mentioning either correct or incorrect labels. Such questions do not convey stark differences in informants' epistemic competence. Inaccurate labels, however, generate error signals that can lead to weaker encoding of novel information. Preschoolers retained novel labels from both informants but were slower to respond in the Inaccurate Labeler condition. When the test procedure was not sensitive to the strength of information encoding, children performed above chance in both conditions and their response times did not differ. These results suggest that epistemic-level inferences and error generalizations influence preschoolers' selective word learning concurrently.

Bridging the Age Gap: a prognostic model that predicts survival and aids in primary treatment decisions for older women with oestrogen receptor-positive early breast cancer

BACKGROUND

A prognostic model was developed and validated using cancer registry data. This underpins an online decision support tool, informing primary treatment choice for women aged 70 years or older with hormone receptor-positive early breast cancer.

METHODS

Data from women diagnosed between 2002 and 2010 in the English Northern and Yorkshire and West Midlands regions were used to develop the model. Primary treatment options of surgery with adjuvant endocrine therapy or primary endocrine therapy were compared. Models predicting the hazard of breast cancer-specific mortality and hazard of other-cause mortality were combined to derive survival probabilities. The model was validated externally using data from the Eastern Cancer Registration and Information Centre.

RESULTS

The model was developed using data from 23 842 women, and validated externally on a data set from 14 526 patients. The overall model calibration was good. At 2 and 5 years, predicted mortality from breast cancer and other causes differed from the observed rate by less than 1 per cent. At 5 years, there were slight overpredictions in breast cancer mortality (2629 predicted versus 2556 observed deaths; P = 0·142) and mortality from all causes (6399 versus 6320 respectively; P = 0·583). The discrepancy varied between subgroups. Model discrimination was 0·75 or above for all mortality measures.

CONCLUSION

A prognostic model for older women with oestrogen receptor-positive early breast cancer was developed and validated in the present study. This forms a basis for an online decision support tool (https://agegap.shef.ac.uk/).

Breast cancer surgery in older women: outcomes of the Bridging Age Gap in Breast Cancer study

Background

Breast cancer surgery in older women is variable and sometimes non-standard owing to concerns about morbidity. Bridging the Age Gap in Breast Cancer is a prospective multicentre cohort study aiming to determine factors influencing treatment selection and outcomes from surgery for older patients with breast cancer.

Methods

Women aged at least 70 years with operable breast cancer were recruited from 57 UK breast units between 2013 and 2018. Associations between patient and tumour characteristics and type of surgery in the breast and axilla were evaluated using univariable and multivariable analyses. Oncological outcomes, adverse events and quality-of-life (QoL) outcomes were monitored for 2 years.

Results

Among 3375 women recruited, surgery was performed in 2816 patients, of whom 24 with inadequate data were excluded. Sixty-two women had bilateral tumours, giving a total of 2854 surgical events. Median age was 76 (range 70–95) years. Breast surgery comprised mastectomy in 1138 and breast-conserving surgery in 1716 procedures. Axillary surgery comprised axillary lymph node dissection in 575 and sentinel node biopsy in 2203; 76 had no axillary surgery. Age, frailty, dementia and co-morbidities were predictors of mastectomy (multivariable odds ratio (OR) for age 1·06, 95 per cent c.i. 1·05 to 1·08). Age, frailty and co-morbidity were significant predictors of no axillary surgery (OR for age 0·91, 0·87 to 0·96). The rate of adverse events was moderate (551 of 2854, 19·3 per cent), with no 30-day mortality. Long-term QoL and functional independence were adversely affected by surgery.

Conclusion

Breast cancer surgery is safe in women aged 70 years or more, with serious adverse events being rare and no mortality. Age, ill health and frailty all influence surgical decision-making. Surgery has a negative impact on QoL and independence, which must be considered when counselling patients about choices.

Underspecification in toddlers' and adults' lexical representations

Recent research has shown that toddlers' lexical representations are phonologically detailed, quantitatively much like those of adults. Studies in this article explore whether toddlers' and adults' lexical representations are qualitatively similar. Psycholinguistic claims (Lahiri & Marslen-Wilson, 1991; Lahiri & Reetz, 2002, 2010) based on underspecification (Kiparsky, 1982 et seq.) predict asymmetrical judgments in lexical processing tasks; these have been supported in some psycholinguistic research showing that participants are more sensitive to noncoronal-to-coronal (pop → top) than to coronal-to-noncoronal (top → pop) changes or mispronunciations. Three experiments using on-line visual world procedures showed that 19-month-olds and adults displayed sensitivities to both noncoronal-to-coronal and coronal-to-noncoronal mispronunciations of familiar words. No hints of any asymmetries were observed for either age group. There thus appears to be considerable developmental continuity in the nature of early and mature lexical representations. Discrepancies between the current findings and those of previous studies appear to be due to methodological differences that cast doubt on the validity of claims of psycholinguistic support for lexical underspecification.

Adjuvant Chemotherapy for Breast Cancer in Older Women: An Analysis of Retrospective English Cancer Registration Data

AIMS

Adjuvant chemotherapy is recommended as a treatment for women with high recurrence risk early breast cancer. Older women are less likely to receive chemotherapy than younger women. This study investigated the impact of chemotherapy on breast cancer-specific survival in women aged 70 + years using English registry data.

MATERIALS AND METHODS

Cancer registration data were obtained from two English regions from 2002 to 2012 (n = 29 728). The impact of patient-level characteristics on the probability of receiving adjuvant chemotherapy was explored using logistic regression. Survival modelling was undertaken to show the effect of chemotherapy and age/health status on breast cancer-specific survival. Missing data were handled using multiple imputation.

RESULTS

In total, 11 735 surgically treated early breast cancer patients were identified. Use of adjuvant chemotherapy has increased over time. Younger age at diagnosis, increased nodal involvement, tumour size and grade, oestrogen receptor-negative or human epidermal growth factor receptor 2-positive disease were all associated with increased probability of receiving chemotherapy. Chemotherapy was associated with a significant reduction in the hazard of breast cancer-specific mortality in women with high risk cancer, after adjusting for patient-level characteristics (hazard ratio 0.74, 95% confidence interval 0.67-0.81).

DISCUSSION

Chemotherapy is associated with an improved breast cancer-specific survival in older women with early breast cancer at high risk of recurrence . Lower rates of chemotherapy use in older women may, therefore, contribute to inferior cancer outcomes. Decisions on potential benefits for individual patients should be made on the basis of life expectancy, treatment tolerance and patient preference.

Asymmetric discrimination of nonspeech tonal analogues of vowels

Directional asymmetries reveal a universal bias in vowel perception favoring extreme vocalic articulations, which lead to acoustic vowel signals with dynamic formant trajectories and well-defined spectral prominences because of the convergence of adjacent formants. The present experiments investigated whether this bias reflects speech-specific processes or general properties of spectral processing in the auditory system. Toward this end, we examined whether analogous asymmetries in perception arise with nonspeech tonal analogues that approximate some of the dynamic and static spectral characteristics of naturally produced /u/ vowels executed with more versus less extreme lip gestures. We found a qualitatively similar but weaker directional effect with 2-component tones varying in both the dynamic changes and proximity of their spectral energies. In subsequent experiments, we pinned down the phenomenon using tones that varied in 1 or both of these 2 acoustic characteristics. We found comparable asymmetries with tones that differed exclusively in their spectral dynamics, and no asymmetries with tones that differed exclusively in their spectral proximity or both spectral features. We interpret these findings as evidence that dynamic spectral changes are a critical cue for eliciting asymmetries in nonspeech tone perception, but that the potential contribution of general auditory processes to asymmetries in vowel perception is limited. (PsycINFO Database Record (c) 2019 APA, all rights reserved).

Eighteen-month-olds selectively generalize words from accurate speakers to novel contexts

The present studies examine whether and how 18-month-olds use informants' accuracy to acquire novel labels for novel objects and generalize them to a new context. In Experiment 1, two speakers made statements about the labels of familiar objects. One used accurate labels and the other used inaccurate labels. One of these speakers then introduced novel labels for two novel objects. At test, toddlers saw those two novel objects and heard an unfamiliar voice say one of the labels provided by the speaker. Only toddlers who had heard the novel labels introduced by the accurate speaker looked at the appropriate novel object above chance. Experiment 2 explored possible mechanisms underlying this difference in generalization. Rather than making statements about familiar objects' labels, both speakers asked questions about the objects' labels, with one speaker using accurate labels and the other using inaccurate labels. Toddlers' generalization of novel labels for novel objects was at chance for both speakers, suggesting that toddlers do not simply associate hearing the accurate label with the reliability of the speaker. We discuss these results in terms of potential mechanisms by which children learn and generalize novel labels across contexts from speaker reliability.

Young infants' discrimination of subtle phonetic contrasts

It is generally accepted that infants initially discriminate native and non-native contrasts and that perceptual reorganization within the first year of life results in decreased discrimination of non-native contrasts, and improved discrimination of native contrasts. However, recent findings from Narayan, Werker, and Beddor (2010) surprisingly suggested that some acoustically subtle native-language contrasts might not be discriminated until the end of the first year of life. We first provide countervailing evidence that young English-learning infants can discriminate the Filipino contrast tested by Narayan et al. when tested in a more sensitive paradigm. Next, we show that young infants learning either English or French can also discriminate comparably subtle non-native contrasts from Tamil. These findings show that Narayan et al.'s null findings were due to methodological choices and indicate that young infants are sensitive to even subtle acoustic contrasts that cue phonetic distinctions cross-linguistically. Based on experimental results and acoustic analyses, we argue that instead of specific acoustic metrics, infant discrimination results themselves are the most informative about the salience of phonetic distinctions.

What influences healthcare professionals' treatment preferences for older women with operable breast cancer? An application of the discrete choice experiment

INTRODUCTION

Primary endocrine therapy (PET) is used variably in the UK as an alternative to surgery for older women with operable breast cancer. Guidelines state that only patients with "significant comorbidity" or "reduced life expectancy" should be treated this way and age should not be a factor.

METHODS

A Discrete Choice Experiment (DCE) was used to determine the impact of key variables (patient age, comorbidity, cognition, functional status, cancer stage, cancer biology) on healthcare professionals' (HCP) treatment preferences for operable breast cancer among older women. Multinomial logistic regression was used to identify associations.

RESULTS

40% (258/641) of questionnaires were returned. Five variables (age, co-morbidity, cognition, functional status and cancer size) independently demonstrated a significant association with treatment preference (p < 0.05). Functional status was omitted from the multivariable model due to collinearity, with all other variables correlating with a preference for operative treatment over no preference (p < 0.05). Only co-morbidity, cognition and cancer size correlated with a preference for PET over no preference (p < 0.05).

CONCLUSION

The majority of respondents selected treatment in accordance with current guidelines, however in some scenarios, opinion was divided, and age did appear to be an independent factor that HCPs considered when making a treatment decision in this population.

Do infants discriminate non-linguistic vocal expressions of positive emotions?

Adults are highly proficient in understanding emotional signals from both facial and vocal cues, including when communicating across cultural boundaries. However, the developmental origin of this ability is poorly understood, and in particular, little is known about the ontogeny of differentiation of signals with the same valence. The studies reported here employed a habituation paradigm to test whether preverbal infants discriminate between non-linguistic vocal expressions of relief and triumph. Infants as young as 6 months who had habituated to relief or triumph showed significant discrimination of relief and triumph tokens at test (i.e. greater recovery to the unhabituated stimulus type), when exposed to tokens from a single individual (Study 1). Infants habituated to expressions from multiple individuals showed less consistent discrimination in that consistent discrimination was only found when infants were habituated to relief tokens (Study 2). Further, infants tested with tokens from individuals from different cultures showed dishabituation only when habituated to relief tokens and only at 10-12 months (Study 3). These findings suggest that discrimination between positive emotional expressions develops early and is modulated by learning. Further, infants' categorical representations of emotional expressions, like those of speech sounds, are influenced by speaker-specific information.

What you see isn't always what you get: Auditory word signals trump consciously perceived words in lexical access

Human speech perception often includes both an auditory and visual component. A conflict in these signals can result in the McGurk illusion, in which the listener perceives a fusion of the two streams, implying that information from both has been integrated. We report two experiments investigating whether auditory-visual integration of speech occurs before or after lexical access, and whether the visual signal influences lexical access at all. Subjects were presented with McGurk or Congruent primes and performed a lexical decision task on related or unrelated targets. Although subjects perceived the McGurk illusion, McGurk and Congruent primes with matching real-word auditory signals equivalently primed targets that were semantically related to the auditory signal, but not targets related to the McGurk percept. We conclude that the time course of auditory-visual integration is dependent on the lexicality of the auditory and visual input signals, and that listeners can lexically access one word and yet consciously perceive another.

Parametric Modeling of the Mouse Left Ventricular Myocardial Fiber Structure

Magnetic resonance diffusion tensor imaging (DTI) has greatly facilitated detailed quantifications of myocardial structures. However, structural patterns, such as the distinctive transmural rotation of the fibers, remain incompletely described. To investigate the validity and practicality of pattern-based analysis, 3D DTI was performed on 13 fixed mouse hearts and fiber angles in the left ventricle were transformed and fitted to parametric expressions constructed from elementary functions of the prolate spheroidal spatial variables. It was found that, on average, the myocardial fiber helix angle could be represented to 6.5° accuracy by the equivalence of a product of 10th-order polynomials of the radial and longitudinal variables, and 17th-order Fourier series of the circumferential variable. Similarly, the fiber imbrication angle could be described by 10th-order polynomials and 24th-order Fourier series, to 5.6° accuracy. The representations, while relatively concise, did not adversely affect the information commonly derived from DTI datasets including the whole-ventricle mean fiber helix angle transmural span and atlases constructed for the group. The unique ability of parametric models for predicting the 3D myocardial fiber structure from finite number of 2D slices was also demonstrated. These findings strongly support the principle of parametric modeling for characterizing myocardial structures in the mouse and beyond.

Attention to the mouth and gaze following in infancy predict language development

We investigated longitudinal relations among gaze following and face scanning in infancy and later language development. At 12 months, infants watched videos of a woman describing an object while their passive viewing was measured with an eye-tracker. We examined the relation between infants' face scanning behavior and their tendency to follow the speaker's attentional shift to the object she was describing. We also collected language outcome measures on the same infants at 18 and 24 months. Attention to the mouth and gaze following at 12 months both predicted later productive vocabulary. The results are discussed in terms of social engagement, which may account for both attentional distribution and language onset. We argue that an infant's inherent interest in engaging with others (in addition to creating more opportunities for communication) leads infants to attend to the most relevant information in a social scene and that this information facilitates language learning.

Primary endocrine therapy as a treatment for older women with operable breast cancer - a comparison of randomised controlled trial and cohort study findings

INTRODUCTION

One third of all breast cancers occur in women over the age of 70. Primary endocrine therapy (PET) is used in some women to minimise morbidity in a population with higher rates of comorbidity and frailty. In the UK up to 40% of women over 70 are treated with PET although there is a high rate of variability of practice between centres reflecting a lack of guidance about case selection.

METHODS

A systematic review of the literature was performed to try and establish if this form of treatment is still valid in modern breast practice.

RESULTS

Six randomised controlled trials (RCTs) and 31 non-randomised studies were deemed eligible. Available data demonstrate an advantage for surgery over PET in terms of disease control and a likely survival benefit in patients with a predicted life expectancy of five years or more. Patients treated only with aromatase inhibitors (AIs) had superior rates of disease control when compared to Tamoxifen.

CONCLUSIONS

Guidelines to aid selection are needed but PET should be reserved for patients with reduced predicted life expectancy (e.g. less than five years), with AIs being preferable over Tamoxifen.

A role for the developing lexicon in phonetic category acquisition

Infants segment words from fluent speech during the same period when they are learning phonetic categories, yet accounts of phonetic category acquisition typically ignore information about the words in which sounds appear. We use a Bayesian model to illustrate how feedback from segmented words might constrain phonetic category learning by providing information about which sounds occur together in words. Simulations demonstrate that word-level information can successfully disambiguate overlapping English vowel categories. Learning patterns in the model are shown to parallel human behavior from artificial language learning tasks. These findings point to a central role for the developing lexicon in phonetic category acquisition and provide a framework for incorporating top-down constraints into models of category learning.

Increased focus on the mouth among infants in the first year of life: A longitudinal eye-tracking study

The present study examines face-scanning behaviors of infants at 6, 9, and 12 months as they watched videos of a woman describing an object in front of her. The videos were created to vary information in the mouth (speaking vs. smiling) and the eyes (gazing into the camera vs. cueing the infant with head turn or gaze direction to an object being described). Infants tended to divide their attention between the eyes and the mouth, looking less at the eyes with age and more at the mouth than the eyes at 9 and 12 months. Attention to the mouth was greater on speaking trials than on smiling trials at all three ages, and this difference increased between 6 and 9 months. Despite consistent results within subjects, there was considerable variation between subjects. This raises the question of whether a developmental "norm" of face scanning in infancy ought to be pursued. Rather, these data add to emerging evidence suggesting that individual differences in face scanning might reliably predict aspects of later development.

Word-level information influences phonetic learning in adults and infants

Infants begin to segment words from fluent speech during the same time period that they learn phonetic categories. Segmented words can provide a potentially useful cue for phonetic learning, yet accounts of phonetic category acquisition typically ignore the contexts in which sounds appear. We present two experiments to show that, contrary to the assumption that phonetic learning occurs in isolation, learners are sensitive to the words in which sounds appear and can use this information to constrain their interpretation of phonetic variability. Experiment 1 shows that adults use word-level information in a phonetic category learning task, assigning acoustically similar vowels to different categories more often when those sounds consistently appear in different words. Experiment 2 demonstrates that 8-month-old infants similarly pay attention to word-level information and that this information affects how they treat phonetic contrasts. These findings suggest that phonetic category learning is a rich, interactive process that takes advantage of many different types of cues that are present in the input.

Adults show less sensitivity to phonetic detail in unfamiliar words, too

Young word learners fail to discriminate phonetic contrasts in certain situations, an observation that has been used to support arguments that the nature of lexical representation and lexical processing changes over development. An alternative possibility, however, is that these failures arise naturally as a result of how word familiarity affects lexical processing. In the present work, we explored the effects of word familiarity on adults' use of phonetic detail. Participants' eye movements were monitored as they heard single-segment onset mispronunciations of words drawn from a newly learned artificial lexicon. In Experiment 1, single-feature onset mispronunciations were presented; in Experiment 2, participants heard two-feature onset mispronunciations. Word familiarity was manipulated in both experiments by presenting words with various frequencies during training. Both word familiarity and degree of mismatch affected adults' use of phonetic detail: in their looking behavior, participants did not reliably differentiate single-feature mispronunciations and correct pronunciations of low frequency words. For higher frequency words, participants differentiated both 1- and 2-feature mispronunciations from correct pronunciations. However, responses were graded such that 2-feature mispronunciations had a greater effect on looking behavior. These experiments demonstrate that the use of phonetic detail in adults, as in young children, is affected by word familiarity. Parallels between the two populations suggest continuity in the architecture underlying lexical representation and processing throughout development.

Is It a Noun or Is It a Verb? Resolving the Ambicategoricality Problem

In many languages, significant numbers of words are used in more than one grammatical category; English, in particular, has many words that can be used as both nouns and verbs. Such ambicategoricality potentially poses problems for children trying to learn the grammatical properties of words and has been used to argue against the logical possibility of learning grammatical categories from syntactic distribution alone. This article addresses how often English-learning children hear words used across categories, whether young language learners might be sensitive to perceptual cues that differentiate noun and verb uses of such words and how young speakers use ambicategorical words. The findings suggest that children hear considerably less cross-category usage than is possible and are sensitive to perceptual cues that distinguish the two categories. Furthermore, in early language production, children's cross-category production mirrors the statistics of their linguistic environments, suggesting that they are distinguishing noun and verb uses of individual words in natural language exposure. Taken together, these results indicate that cues in the speech stream may help children resolve the ambicategoricality problem.

Abdominal trauma in primary blast injury

BACKGROUND

Blast injury is uncommon, and remains poorly understood by most clinicians outside regions of active warfare. Primary blast injury (PBI) results from the interaction of the blast wave with the body, and typically affects gas-containing organs such as the ear, lungs and gastrointestinal tract. This review investigates the mechanisms and injuries sustained to the abdomen following blast exposure.

METHODS

MEDLINE was searched using the keywords 'primary blast injury', 'abdominal blast' and 'abdominal blast injury' to identify English language reports of abdominal PBI. Clinical reports providing sufficient data were used to calculate the incidence of abdominal PBI in hospitalized survivors of air blast, and in open- and enclosed-space detonations.

RESULTS

Sixty-one articles were identified that primarily reported clinical or experimental abdominal PBI. Nine clinical reports provided sufficient data to calculate an incidence of abdominal PBI; 31 (3·0 per cent) of 1040 hospitalized survivors of air blast suffered abdominal PBI, the incidence ranging from 1·3 to 33 per cent. The incidence for open- and enclosed-space detonations was 5·6 and 6·7 per cent respectively. The terminal ileum and caecum were the most commonly affected organs. Surgical management of abdominal PBI is similar to that of abdominal trauma of other causes.

CONCLUSION

Abdominal PBI is uncommon but has the potential for significant mortality and morbidity, which may present many days after blast exposure. It is commoner after blast in enclosed spaces and under water.

Is early word-form processing stress-full? How natural variability supports recognition

In a series of studies, we examined how mothers naturally stress words across multiple mentions in speech to their infants and how this marking influences infants' recognition of words in fluent speech. We first collected samples of mothers' infant-directed speech using a technique that induced multiple repetitions of target words. Acoustic analyses revealed that mothers systematically alternated between emphatic and nonemphatic stress when talking to their infants. Using the headturn preference procedure, we then tested 7.5-month-old infants on their ability to detect familiarized bisyllabic words in fluent speech. Stress of target words (emphatic and nonemphatic) was systematically varied across familiarization and recognition phases of four experiments. Results indicated that, although infants generally prefer listening to words produced with emphatic stress, recognition was enhanced when the degree of emphatic stress at familiarization matched the degree of emphatic stress at recognition.

The influence of categories on perception: explaining the perceptual magnet effect as optimal statistical inference

A variety of studies have demonstrated that organizing stimuli into categories can affect the way the stimuli are perceived. We explore the influence of categories on perception through one such phenomenon, the perceptual magnet effect, in which discriminability between vowels is reduced near prototypical vowel sounds. We present a Bayesian model to explain why this reduced discriminability might occur: It arises as a consequence of optimally solving the statistical problem of perception in noise. In the optimal solution to this problem, listeners' perception is biased toward phonetic category means because they use knowledge of these categories to guide their inferences about speakers' target productions. Simulations show that model predictions closely correspond to previously published human data, and novel experimental results provide evidence for the predicted link between perceptual warping and noise. The model unifies several previous accounts of the perceptual magnet effect and provides a framework for exploring categorical effects in other domains.

Acoustical cues and grammatical units in speech to two preverbal infants

The current study examines the syntactic and prosodic characteristics of the maternal speech to two infants between six and ten months. Consistent with previous work, we find infant-directed speech to be characterized by generally short utterances, isolated words and phrases, and large numbers of questions, but longer utterances are also found. Prosodic information provides cues to grammatical units not only at utterance boundaries, but also at utterance-internal clause boundaries. Subject-verb phrase boundaries in questions also show reliable prosodic cues, although those of declaratives do not. Prosodic information may thus play an important role in providing preverbal infants with information about the grammatically relevant word groupings. Furthermore, questions may play an important role in infants' discovery of verb phrases in English.

Rapid acquisition of phonological alternations by infants

We explore whether infants can learn novel phonological alternations on the basis of distributional information. In Experiment 1, two groups of 12-month-old infants were familiarized with artificial languages whose distributional properties exhibited either stop or fricative voicing alternations. At test, infants in the two exposure groups had different preferences for novel sequences involving voiced and voiceless stops and fricatives, suggesting that each group had internalized a different familiarization alternation. In Experiment 2, 8.5-month-olds exhibited the same patterns of preference. In Experiments 3 and 4, we investigated whether infants' preferences were driven solely by preferences for sequences of high transitional probability. Although 8.5-month-olds in Experiment 3 were sensitive to the relative probabilities of sequences in the familiarization stimuli, only 12-month-olds in Experiment 4 showed evidence of having grouped alternating segments into a single functional category. Taken together, these results suggest a developmental trajectory for the acquisition of phonological alternations using distributional cues in the input.

Twenty-two-month-olds discriminate fluent from disfluent adult-directed speech

Deviation of real speech from grammatical ideals due to disfluency and other speech errors presents potentially serious problems for the language learner. While infants may initially benefit from attending primarily or solely to infant-directed speech, which contains few grammatical errors, older infants may listen more to adult-directed speech. In a first experiment, Post-verbal infants preferred fluent speech to disfluent speech, while Pre-verbal infants showed no preference. In a second experiment, Post-verbal infants discriminated disfluent and fluent speech even when lexical information was removed, showing that they make use of prosodic properties of the speech stream to detect disfluency. Because disfluencies are highly correlated with grammatical errors, this sensitivity provides infants with a means of filtering ungrammaticality from their input.

Mommy and me: familiar names help launch babies into speech-stream segmentation

How do infants find the words in the tangle of speech that confronts them? The present study shows that by as early as 6 months of age, infants can already exploit highly familiar words-including, but not limited to, their own names-to segment and recognize adjoining, previously unfamiliar words from fluent speech. The head-turn preference procedure was used to familiarize babies with short passages in which a novel word was preceded by a familiar or a novel name. At test, babies recognized the word that followed the familiar name, but not the word that followed the novel name. This is the youngest age at which infants have been shown capable of segmenting fluent speech. Young infants have a powerful aid available to them for cracking the speech code. Their emerging familiarity with particular words, such as their own and other people's names, can provide initial anchors in the speech stream.

A statistical basis for speech sound discrimination

Infants under six months are able to discriminate native and non-native consonant contrasts equally well, but as they learn the phonological systems of their native language, this ability declines. Current explanations of this phenomenon agree that the decline in discrimination ability is linked to the formation of native-language phonemic categories. The goal of this study was to evaluate the role of input statistics in learning these categories: our hypothesis was that relative frequency is a determinant of the relative order in which categories are acquired. English-learning infants of two age groups (6.5 months and 8.5 months) were tested on their ability to discriminate non-native consonant contrasts using the Conditioned Head Turn Procedure. As predicted, older infants were worse in their performance on the more frequent coronal stop contrast than on the less frequent dorsal stop contrast. In contrast, 6.5-month-olds discriminated both contrasts equally well. An adult control group tested with an AX task also discriminated both contrasts equally. These results provide preliminary confirmation of the hypothesis that frequency plays an important role in tuning of phonological systems to properties of the native language. A simple attractor model suffices to account for these and previous results on loss of discrimination of non-native-language contrasts and suggests that the technique of measuring graded loss of multiple contrasts, in combination with observation of input frequencies, can offer a powerful method of assessing infants' phonological representations.

Infants' Listening Preferences: Baby Talk or Happy Talk?

The most robust finding on infants' listening preferences has been widely characterized as a preference for baby talk (BT) over adult-directed speech (ADS). Although prosodic modifications characteristic of BT also convey positive affect, differences in affect across BT and ADS speech registers have not been controlled in previous studies. This set of experiments sought to elucidate the basis for 6-month-olds' listening preference by independently manipulating affect and speech register. When affect was held constant, no preference for any speech register was observed. Moreover, when ADS stimuli presented more positive affect than BT stimuli, infants' preferences followed the positive affect. Higher and more variable pitch was neither necessary nor sufficient for determining infants' preferences, although pitch characteristics may modulate affect-based preferences. The BT preference is thus attributable to a more general preference for speech that imparts relatively positive affect, a preference perhaps ascribable to a preexisting general-purpose mechanism opportunistically exploited by language.

Is intrinsic sphincter deficiency a complication of simple hysterectomy?

PURPOSE

Intrinsic sphincter deficiency may cause disabling stress urinary incontinence. While some pelvic operations are implicated as a cause of this condition, simple hysterectomy for benign disease is not recognized as one of them. We evaluated the association of simple hysterectomy with intrinsic sphincter deficiency.

MATERIALS AND METHODS

We performed a case control study to assess the association of simple hysterectomy with intrinsic sphincter deficiency in a consecutive group of 387 incontinent women. From 1995 to 1997 we identified 67 patients with and 67 controls without a history of hysterectomy. Further comparison was done after forming a subgroup at low risk for intrinsic sphincter deficiency. All patients were evaluated by a fluoroscopic urodynamic technique and abdominal leak point pressure was determined.

RESULTS

Intrinsic sphincter deficiency was present in 48% of the 67 patients and 24% of the 67 controls. In the lower risk subgroup we noted this condition in 29 patients (52%) and 53 controls (21%).

CONCLUSIONS

In this population of incontinent women intrinsic sphincter deficiency, as diagnosed by low abdominal leak point pressure, appears to be a complication of simple hysterectomy.

Circadian rhythm of the preovulatory surge of luteinizing hormone and its relationships to rhythms of body temperature and locomotor activity in turkey hens

Simultaneous measurements of plasma LH, body temperature, and locomotor activity were made in laying turkey hens and are reported. Blood samples were remotely collected using a jugular cannula system, and body temperature and locomotor activity were remotely monitored using a radiotelemetry system in freely moving laying turkeys. Under a photoschedule of 14L:10D, the period for preovulatory surges of LH was 25.7 +/- 0.4 h while the periods for peak body temperature and onset of sustained locomotor activity were 24.9 +/- 0.4 and 25.7 +/- 0.5 h, respectively. During exposure to constant light, the periods for preovulatory surges of LH, peak body temperature, and onset of sustained locomotor activity increased to 27.9 +/- 0.9, 26.7 +/- 0.7, and 27.4 +/- 0.7 h, respectively. With the 14L:10D photoschedule, initiation of LH surges was restricted to the scotophase, but after 8 days of constant light, initiation of LH surges had dispersed throughout the 24-h subjective day and night. With constant light, the amplitude of the peak body temperature rhythm decreased, while the duration of the locomotor activity rhythm became broadened and, in some birds, disorganized. Peak body temperature and onset of locomotor activity rhythms and LH surges did not coincide, even though peak body temperature, onset of locomotor activity, and LH surges had similar periods. It is concluded that 1) the photoschedule influences the periods of the LH surge, peak body temperature, and onset of locomotor activity; and 2) a specific or direct relationship between the rhythms of LH surge, body temperature, and locomotor activity remains to be determined in laying turkey hens.

Effects of 60 Hz magnetic field exposure on polymorphonuclear leukocyte activation

We have investigated the effects of a sinusoidal 60 Hz magnetic field on free radical (superoxide anion) production, degranulation (beta-glucuronidase and lysozyme release) and viability in human neutrophils (PMNs). Experiments were performed blindly in very controlled conditions to examine the effects of a magnetic field in resting PMNs and in PMNs stimulated with a tumor promoter: phorbol 12-myristate 13-acetate (PMA). Exposure of unstimulated human PMNs to a 60 Hz magnetic field did not affect the functions examined. In contrast, exposure of PMNs to a 22 milliTesla (mT), 60 Hz magnetic field induced significant increases in superoxide anion (O2-) production (26.5%) and in beta-glucuronidase release (53%) when the cells were incubated with a suboptimal stimulating dose of PMA. Release of lysozyme and lactate dehydrogenase was unchanged by the magnetic field, whether the cells were stimulated or not. A 60 Hz magnetic field did not have any effect on O2- generation by a cell-free system xanthine/xanthine oxidase, suggesting that a magnetic field could upregulate common cellular events (signal transduction) leading to O2- generation and beta-glucuronidase release. In conclusion, exposure of PMNs to a 22 mT, 60 Hz magnetic field potentiates the effect of PMA on O2- generation and beta-glucuronidase release. This effect could be the result of an alteration in the intracellular signaling.

Newborn infants' sensitivity to perceptual cues to lexical and grammatical words

In our study newborn infants were presented with lists of lexical and grammatical words prepared from natural maternal speech. The results show that newborns are able to categorically discriminate these sets of words based on a constellation of perceptual cues that distinguish them. This general ability to detect and categorically discriminate sets of words on the basis of multiple acoustic and phonological cues may provide a perceptual base that can help older infants bootstrap into the acquisition of grammatical categories and syntactic structure.

Hepatitis B virus transgenic mouse model of chronic liver disease

A model for hepatitis B virus-associated chronic liver disease has been made using cloned hepatitis B virus DNA as a transgene in a severe combined immunodeficient host. These mice consistently support virus gene expression and replication. After adoptive transfer of unprimed, syngeneic splenocytes, these mice cleared virus from liver and serum, and developed chronic liver disease. This model will permit identification of the host and virus contributions to chronic liver disease in the absence of tolerance.

Phonotactic and prosodic effects on word segmentation in infants

This research examines the issue of speech segmentation in 9-month-old infants. Two cues known to carry probabilistic information about word boundaries were investigated: Phonotactic regularity and prosodic pattern. The stimuli used in four head turn preference experiments were bisyllabic CVC.CVC nonwords bearing primary stress in either the first or the second syllable (strong/weak vs. weak/strong). Stimuli also differed with respect to the phonotactic nature of their cross-syllabic C.C cluster. Clusters had either a low probability of occurring at a word juncture in fluent speech and a high probability of occurring inside of words ("within-word" clusters) or a high probability of occurring at a word juncture and a low probability of occurring inside of words ("between-word" clusters). Our results show that (1) 9-month-olds are sensitive to how phonotactic sequences typically align with word boundaries, (2) altering the stress pattern of the stimuli reverses infants' preference for phonotactic cluster types, (3) the prosodic cue to segmentation is more strongly relied upon than the phonotactic cue, and (4) a preference for high-probability between-word phonotactic sequences can be obtained either by placing stress on the second syllable of the stimuli or by inserting a pause between syllables. The implications of these results are discussed in light of an integrated multiple-cue approach to speech segmentation in infancy.

Phonological and acoustic bases for earliest grammatical category assignment: a cross-linguistic perspective

Maternal infant-directed speech in Mandarin Chinese and Turkish (two mother-child dyads each; ages of children between 0;11 and 1;8) was examined to see if cues exist in input that might assist infants' assignment of words to lexical and functional item categories. Distributional, phonological, and acoustic measures were analysed. In each language, lexical and functional items (i.e. syllabic morphemes) differed significantly on numerous measures. Despite differences in mean values between categories, distributions of values typically displayed substantial overlap. However, simulations with self-organizing neural networks supported the conclusion that although individual dimensions had low cue validity, in each language multidimensional constellations of presyntactic cues are sufficient to guide assignment of words to rudimentary grammatical categories.

Determination of testis temperature rhythms and effects of constant light on testicular function in the domestic fowl (Gallus domesticus)

There is a wide range of opinions regarding the operating temperature of the testis in the domestic fowl. We used physiological monitoring techniques to investigate testis and body temperature over daily periods and under various light regimes to elucidate body temperature gradients in the fowl. We confirm that the operating temperature of the adult fowl's testes is equivalent to core body temperature (40-41 degrees C). Long-term continuous temperature monitoring showed that there was no difference between the temperature of the testis, liver, and peritoneum during a 24-h period either in a normal light:dark cycle or under constant light conditions. However, there was a slight decrease in all temperatures at subjective night in each case, a decrease that does not appear to be sufficient to influence spermatogenesis. Birds maintained under constant light throughout two cycles of the seminiferous epithelium (28 days) still exhibited normal testis function and structure, even when "nightly" testis temperature decrease was the lowest. Thus, by undergoing spermatogenesis at an elevated temperature, the domestic fowl system is unique among the homeothermic animal systems studied to date.

Osteoid osteoma and osteoblastoma: MRI appearances and the significance of ring enhancement

We assessed the value of contrast-enhanced fat-suppressed MRI on nine patients with osteoid osteomas and osteoblastomas. The results were compared with plain films, bone scintigraphy, computed tomography (CT) and pathological specimens. On contrast-enhanced fat-suppressed T1-weighted images the non-calcified nidi showed homogeneous enhancement, whereas the calcified lesions showed a ring enhancement sign that was proportional in intensity to the extent of the remaining part of the vascularized nidus. The degree of bone marrow and soft tissue enhancement was relative to the size and reactive inflammatory changes of the lesions. Although CT was diagnostic in most of the cases and more specific to show the calcified lesions, MRI was confirmatory in one case. We concluded that, although CT is the primary diagnostic investigation in osteoid osteomas, MRI can be reserved for equivocal cases.

Expression pattern and mapping of the murine versican gene (Cspg2) to chromosome 13

Versican is a modular proteoglycan harboring a hyaluronan-binding domain at its amino-terminal end and a selectin-like domain at its carboxyl-terminal end, separated by a large intervening region containing the attachment sites for the glycosaminoglycan side chains. By virtue of its modular nature, versican may play a role in cellular attachment, migration, and proliferation by interacting with cell surfaces and extracellular matrix molecules. To discern the function of versican through the analysis of spontaneous and targeted genetic mutations, we have isolated a mouse versican cDNA encoding part of the hyaluronan-binding region, analyzed its mRNA expression in various adult mouse tissues and embryos, and determined the chromosomal location of the gene. Murine versican was 89% identical to human versican at the amino acid level and was highly expressed in mouse embryos at Days 13, 14, and 18. Expression was also detected in adult mouse brain, heart, lung, spleen, skeletal muscle, skin, tail, kidney, and testis. Using interspecific backcross analysis, we assigned the versican gene (Cspg2) to mouse chromosome 13, in a region that is syntenic with the long arm of human chromosome 5 where the human CSPG2 gene is located.