Left dorsolateral prefrontal cortex supports context-dependent prioritisation of off-task thought.

When environments lack compelling goals, humans often let their minds wander to thoughts with greater personal relevance; however, we currently do not understand how this context-dependent prioritisation process operates. Dorsolateral prefrontal cortex (DLPFC) maintains goal representations in a context-dependent manner. Here, we show this region is involved in prioritising off-task thought in an analogous way. In a whole brain analysis we established that neural activity in DLPFC is high both when 'on-task' under demanding conditions and 'off-task' in a non-demanding task. Furthermore, individuals who increase off-task thought when external demands decrease, show lower correlation between neural signals linked to external tasks and lateral regions of the DMN within DLPFC, as well as less cortical grey matter in regions sensitive to these external task relevant signals. We conclude humans prioritise daydreaming when environmental demands decrease by aligning cognition with their personal goals using DLPFC.

Support of adolescents to resist peer pressure and coercion to sexual activity.

AIM: The aim of this study was to explore and describe how peer pressure and coercion to sexual activity manifested among adolescents in a district in South African and how primary healthcare nurses could support them to resist it. BACKGROUND: When adolescents engage in early sexual activity, unplanned pregnancies and sexual transmitted infections become health threats. Notwithstanding the governmental health promotion programmes to improve the sexual health of the youth in South Africa, adolescents are still having unprotected sex and even multiple sex partners. METHODS: A constructivist grounded theory study was done. The initial sample consisted of 10 adolescents and nine professional nurses who were selected from six primary healthcare clinics in the identified district. Constant comparative data collection and analysis were done to identify the initial codes that were theoretically saturated through another round of data collection and analysis involving five participants (four professional nurses and one health educator). FINDINGS: The findings of the study refer to the definition of peer pressure and coercion and the relationship between professional nurses and adolescents. Ways to optimize the relationship in order for nurses to substitute for parental shortcomings in guiding adolescents towards responsible sexual behaviour and to address the adolescents' vulnerability regarding peer pressure were identified. CONCLUSION: Challenging adolescent-nurse interaction incidents were identified that warranted different approaches to build on existing initiatives to improve adolescent-friendly health services. IMPLICATIONS FOR NURSING PRACTICE AND POLICY: Primary healthcare nurses should perform complementary roles to substitute for parents who do not have the skills to guide their adolescent children towards responsible sexual behaviour. Programmes need to be developed to enable nurses to optimize their relationships with adolescents and to deliver services through mobile healthcare units to adolescents where they regular socialize. Management should provide budgets for nurses to use multimedia to interact with adolescents.

An fMRI study of visuo-vestibular interactions following vestibular neuritis.

Vestibular neuritis (VN) is characterised by acute vertigo due to a sudden loss of unilateral vestibular function. A considerable proportion of VN patients proceed to develop chronic symptoms of dizziness, including visually induced dizziness, specifically during head turns. Here we investigated whether the development of such poor clinical outcomes following VN, is associated with abnormal visuo-vestibular cortical processing. Accordingly, we applied functional magnetic resonance imaging to assess brain responses of chronic VN patients and compared these to controls during both congruent (co-directional) and incongruent (opposite directions) visuo-vestibular stimulation (i.e. emulating situations that provoke symptoms in patients). We observed a focal significant difference in BOLD signal in the primary visual cortex V1 between patients and controls in the congruent condition (small volume corrected level of p < .05 FWE). Importantly, this reduced BOLD signal in V1 was negatively correlated with functional status measured with validated clinical questionnaires. Our findings suggest that central compensation and in turn clinical outcomes in VN are partly mediated by adaptive mechanisms associated with the early visual cortex.

The role of energy intake and energy misreporting in the associations between eating patterns and adiposity.

BACKGROUND/OBJECTIVES: Research examining associations between eating occasion (EO) frequency and adiposity is inconclusive; studies examining the impact of energy misreporting are rare. This study examined associations between eating patterns and adiposity, with adjustment for energy misreporting, in a nationally representative sample of Australian adults. SUBJECTS/METHODS: Dietary intake was assessed via two 24-h recalls collected during the 2011-12 National Nutrition and Physical Activity Survey (n=4050 adults, aged ⩾19 years). Frequencies of all EOs, meals and snacks were calculated. Height, weight and waist circumference (WC) were measured. Energy misreporting was assessed as the ratio of energy intake to predicted energy expenditure (EI:EE). Energy misreporters were identified by EI:EE ratios, <0.68 or >1.32. Multivariate regression models assessed associations between eating patterns and body mass index (BMI), WC, overweight/obesity (BMI ⩾25 kg m-2) and central overweight/obesity (WC ⩾94 cm in men and ⩾80 cm in women). RESULTS: After adjustment for covariates and EI:EE, frequency of all EOs, meals (women only) and snacks was positively associated with WC and BMI (all P<0.01). Snack, but not meal frequency, was also associated with overweight/obesity (men: OR=1.22, 95% CI 1.07-1.39; women: OR=1.26, 95% CI 1.10-1.43) and central overweight/obesity (men: OR=1.17, 95% CI 1.04-1.32; women: OR=1.21, 95% CI 1.06-1.37). Multivariate analysis that excluded energy misreporters and adjusted for EI yielded either null or inverse associations (P<0.05). CONCLUSIONS: These findings suggest that the associations between eating patterns and adiposity are complicated by the role of EI and energy misreporting. Longitudinal research that considers the impact of EI and energy misreporting is needed to better understand the relationship between eating patterns and obesity.

Psilocybin with psychological support improves emotional face recognition in treatment-resistant depression.

RATIONALE: Depressed patients robustly exhibit affective biases in emotional processing which are altered by SSRIs and predict clinical outcome. OBJECTIVES: The objective of this study is to investigate whether psilocybin, recently shown to rapidly improve mood in treatment-resistant depression (TRD), alters patients' emotional processing biases. METHODS: Seventeen patients with treatment-resistant depression completed a dynamic emotional face recognition task at baseline and 1 month later after two doses of psilocybin with psychological support. Sixteen controls completed the emotional recognition task over the same time frame but did not receive psilocybin. RESULTS: We found evidence for a group × time interaction on speed of emotion recognition (p = .035). At baseline, patients were slower at recognising facial emotions compared with controls (p < .001). After psilocybin, this difference was remediated (p = .208). Emotion recognition was faster at follow-up compared with baseline in patients (p = .004, d = .876) but not controls (p = .263, d = .302). In patients, this change was significantly correlated with a reduction in anhedonia over the same time period (r = .640, p = .010). CONCLUSIONS: Psilocybin with psychological support appears to improve processing of emotional faces in treatment-resistant depression, and this correlates with reduced anhedonia. Placebo-controlled studies are warranted to follow up these preliminary findings.

Functional neuroimaging of visuo-vestibular interaction.

The brain combines visual, vestibular and proprioceptive information to distinguish between self- and world motion. Often these signals are complementary and indicate that the individual is moving or stationary with respect to the surroundings. However, conflicting visual motion and vestibular cues can lead to ambiguous or false sensations of motion. In this study, we used functional magnetic resonance imaging to explore human brain activation when visual and vestibular cues were either complementary or in conflict. We combined a horizontally moving optokinetic stimulus with caloric irrigation of the right ear to produce conditions where the vestibular activation and visual motion indicated the same (congruent) or opposite directions of self-motion (incongruent). Visuo-vestibular conflict was associated with increased activation in a network of brain regions including posterior insular and transverse temporal areas, cerebellar tonsil, cingulate and medial frontal gyri. In the congruent condition, there was increased activation in primary and secondary visual cortex. These findings suggest that when sensory information regarding self-motion is contradictory, there is preferential activation of multisensory vestibular areas to resolve this ambiguity. When cues are congruent, there is a bias towards visual cortical activation. The data support the view that a network of brain areas including the posterior insular cortex may play an important role in integrating and disambiguating visual and vestibular cues.

Is the relationship between sedentary behaviour and cardiometabolic health in adolescents independent of dietary intake? A systematic review.

Screen time, but not overall sedentary behaviour, is consistently related to cardiometabolic health in adolescents. Because of the associations screen time has with dietary intake, diet may be an important factor in the screen time and health relationship; however, evidence has not previously been synthesized. Thus, the aim of this systematic review was to explore whether the associations between various sedentary behaviours and cardiometabolic risk markers are independent of dietary intake in adolescents. Online databases and personal libraries were searched for peer-reviewed original research articles published in English before March 2014. Included studies assessed associations between sedentary behaviour and cardiometabolic markers in 12- to 18-year-olds and adjusted for dietary intake. Twenty-five studies met the inclusion criteria. From the 21 studies examining sedentary behaviour and adiposity, the majority found significant positive associations between television viewing, screen time and self-reported overall sedentary behaviour with markers of adiposity, independent of dietary intake. No significant associations between screen time with blood pressure and cholesterol were reported. Sedentary behaviour appears to be associated with adiposity in adolescents, irrespective of dietary intake. However, the variability of dietary variables between studies suggests further work is needed to understand the role of dietary intake when examining these associations in youth.

Clustering of diet, physical activity and sedentary behaviour among Australian children: cross-sectional and longitudinal associations with overweight and obesity.

BACKGROUND/OBJECTIVES: Evidence suggests diet, physical activity (PA) and sedentary behaviour cluster together in children, but research supporting an association with overweight/obesity is equivocal. Furthermore, the stability of clusters over time is unknown. The aim of this study was to examine the clustering of diet, PA and sedentary behaviour in Australian children and cross-sectional and longitudinal associations with overweight/obesity. Stability of obesity-related clusters over 3 years was also examined. SUBJECTS/METHODS: Data were drawn from the baseline (T1: 2002/2003) and follow-up waves (T2: 2005/2006) of the Health Eating and Play Study. Parents of Australian children aged 5-6 (n=87) and 10-12 years (n=123) completed questionnaires. Children wore accelerometers and height and weight were measured. Obesity-related clusters were determined using K-medians cluster analysis. Multivariate regression models assessed cross-sectional and longitudinal associations between cluster membership, and body mass index (BMI) Z-score and weight status. Kappa statistics assessed cluster stability over time. RESULTS: Three clusters, labelled 'most healthy', 'energy-dense (ED) consumers who watch TV' and 'high sedentary behaviour/low moderate-to-vigorous PA' were identified at baseline and at follow-up. No cross-sectional associations were found between cluster membership, and BMI Z-score or weight status at baseline. Longitudinally, children in the 'ED consumers who watch TV' cluster had a higher odds of being overweight/obese at follow-up (odds ratio=2.8; 95% confidence interval: 1.1, 6.9; P<0.05). Tracking of cluster membership was fair to moderate in younger (K=0.24; P=0.0001) and older children (K=0.46; P<0.0001). CONCLUSIONS: This study identified an unhealthy cluster of TV viewing with ED food/drink consumption, which predicted overweight/obesity in a small longitudinal sample of Australian children. Cluster stability was fair to moderate over 3 years and is a novel finding. Prospective research in larger samples is needed to examine how obesity-related clusters track over time and influence the development of overweight and obesity.

Clustering of children's obesity-related behaviours: associations with sociodemographic indicators.

BACKGROUND/OBJECTIVES: Research suggests obesity-related behaviours cluster together in children and adolescents, but how these cluster patterns differ by sociodemographic indicators remains unclear. Furthermore, few studies examining clustering of behaviours have included younger children or an objective measure of physical activity (PA) and sedentary behaviour. Therefore, the aim of this study was to examine clustering patterns of diet, PA and sedentary behaviour in 5- to 6- and 10- to 12-year-old children, and their cross-sectional associations with sociodemographic indicators. SUBJECTS/METHODS: In this cross-sectional study, data from the baseline wave (2002/2003) of the Health Eating and Play study (HEAPS) were used. Questionnaires were completed by parents of Australian children aged 5-6 (n=362) and 10-12 years (n=610). Children wore accelerometers for up to 7 days. K-medians cluster analysis identified groups of children with similar diet, PA and sedentary behaviours. Chi-square tests assessed cluster differences by gender, maternal education and marital status. RESULTS: For each age group, three reliable and meaningful clusters were identified and labelled 'most healthy', 'energy-dense (ED) consumers who watch TV' and 'high sedentary behaviour/low moderate-to-vigorous PA (MVPA)'. Clusters varied by sociodemographic indicators. For example, a higher proportion of older girls comprised the 'high sedentary behaviour/low MVPA' cluster (χ(2)=22.4, P<0.001). Among both age groups, the 'ED consumers who watch TV' cluster comprised more children with lower educated mothers (younger children: χ(2)=34.9, P<0.001; older children: χ(2)=27.3, P<0.001). CONCLUSIONS: Identification of cluster patterns of obesity-related risk factors in children, and across sociodemographic groups may assist the targeting of public health initiatives, to those most in need.

Implications for psychedelic-assisted psychotherapy: functional magnetic resonance imaging study with psilocybin.

BACKGROUND: Psilocybin is a classic psychedelic drug that has a history of use in psychotherapy. One of the rationales for its use was that it aids emotional insight by lowering psychological defences. AIMS: To test the hypothesis that psilocybin facilitates access to personal memories and emotions by comparing subjective and neural responses to positive autobiographical memories under psilocybin and placebo. METHOD: Ten healthy participants received two functional magnetic resonance imaging scans (2 mg intravenous psilocybin v. intravenous saline), separated by approximately 7 days, during which they viewed two different sets of 15 positive autobiographical memory cues. Participants viewed each cue for 6 s and then closed their eyes for 16 s and imagined re-experiencing the event. Activations during this recollection period were compared with an equivalent period of eyes-closed rest. We split the recollection period into an early phase (first 8 s) and a late phase (last 8 s) for analysis. RESULTS: Robust activations to the memories were seen in limbic and striatal regions in the early phase and the medial prefrontal cortex in the late phase in both conditions (P<0.001, whole brain cluster correction), but there were additional visual and other sensory cortical activations in the late phase under psilocybin that were absent under placebo. Ratings of memory vividness and visual imagery were significantly higher after psilocybin (P<0.05) and there was a significant positive correlation between vividness and subjective well-being at follow-up (P<0.01). CONCLUSIONS: Evidence that psilocybin enhances autobiographical recollection implies that it may be useful in psychotherapy either as a tool to facilitate the recall of salient memories or to reverse negative cognitive biases.

The management of infant developmental needs by community nurses. Part 1: description of the responsibilities of community nurses with regard to the management of infant developmental needs.

This article is one of two that describes the responsibilities of community nurses, according to their legal scope of practice, with regard to the management of developmental needs of infants in primary health care clinics in South Africa. A subsequent article describes the development of guidelines for the support of community nurses to address the developmental needs of infants 0-2 years. While evidence confirms that developmental surveillance should be incorporated into the ongoing health care of the infant, such services are not consistently provided in health care settings and, if provided, the delivery thereof suffers from significant inadequacies. A case study strategy was used to investigate the phenomenon and content analysis utilised to analyze the data. The Transactional Model of Development was selected to interpret the data obtained in the study. Findings of the study show that infant developmental care is not included to its fullest potential in the health care delivered to infants and their families, thereby indicating that community nurses do not meet the standards of the profession with regard to the management of infant developmental needs. Health service managers need to review their commitment and type of support to community nurses, if infant developmental care, as part of community nurses' responsibilities, is to be effective and of high quality. Furthermore, community nurses and other health care professionals must recognize the nature and potential of inter-professional collaboration to ensure positive outcomes for infants with developmental delays and disabilities.

The management of infant developmental needs by community nurses. Part 2: the development of guidelines for the support of community nurses in the management of infant developmental needs.

In the previous article, the author described, according to the scope of practice of registered nurses, the responsibilities of community nurses with regard to the management of infant developmental needs in primary health care clinics in South Africa. In this article, the focus is on the development of guidelines for the support of community nurses in fulfilling these responsibilities. Before the development of the guidelines is addressed, a brief overview of the background of the study, assumptions of the researcher and the methodology of the study is given. The development of the set of guidelines (DEFINE HOPE) is set against the background of the drive to improve the quality of developmental care for infants and their families. As guidelines help to translate scientific information into statements, it could be valuable to community nurses to improve their delivery of developmental care. To gather evidence for the formulation of the guidelines, the researcher utilised the themes identified during the analysis process in phase one of the research; investigated research articles; and compared findings and recommendations of the articles with the research findings obtained in phase one. In addition to the research findings and literature review, a focus group (health care professionals represented in the case study), was utilised to assist with the final development and validation of the guidelines. The researcher adapted a number of desirable attributes for guidelines, which are indicated in the literature, to compile the criteria for validation of the guidelines. In conclusion, guidelines are necessary to support community nurses in finding "best practice" within their scope of practice to ensure higher quality of developmental care to families with infants 0-2 years.

Thalamic dementia: an example of primary astroglial dystrophy of Seitelberger.

Pure thalamic dementia is highly uncommon and typically demonstrates widespread loss of neurons throughout the thalamus associated with reactive gliosis. This report describes an autopsy case in which there is widespread gliosis of subcortical white matter, focal hippocampal sclerosis and a unique proliferation of protoplasmic astrocytes in the thalamus, with limited bilateral focal loss of neurons. The alterations of the protoplasmic astrocytes consist of proliferation of perivascular feet surrounding blood vessels and velate sheets which surround individual neurons. It is proposed that the astrocytic alterations, or astrocytic dystrophy, constitute the primary and critical pathologic-change, sufficiently severe to produce dementia in the presence of a relatively intact neuronal population.

Pituitary adenoma: a DNA flow cytometric study of 192 clinicopathologically characterized tumors.

A clinically, immunohistochemically and ultrastructurally characterized series of 192 pituitary adenomas was analyzed for DNA content by flow cytometry. Results were assessed not only relative to tumor immunotype, size, and invasiveness, but also with frequency of recurrence. Case selection was non-random; males predominated (1.8:1) and the ratio of macro-to-microadenomas was 4.2:1. Female patients were slightly younger and, in all adenoma categories, less often had invasive tumors: PRL (15%/30%), ACTH (17%/44%), LH/FSH (8%/27%) and null cell adenomas (0%/27%). With the exception of prolactin cell adenomas, similar proportions of macroadenomas and invasive tumors in all tumor subtypes were diploid and non-diploid. Prolactin adenomas differed in that tumors of males showed a high rate of non-diploidy (65%); such tumors were predominantly macroadenomas, but only 28% were invasive. Among GH-containing tumors 78% were macroadenomas, 40% were nondiploid, and the frequency of invasive macroadenomas was higher (49%) than in PRL tumors (21%). ACTH adenomas were mainly microadenomas (81%), their rate invasion (29%) and of non-diploidy being low (14%). Among "non-functioning" (LH/FSH, null cell adenomas), LH/FSH-producing tumors were all macroadenomas, but with low rates of invasion (23%) and non-diploidy (9%). Null cell adenomas, nearly all macroadenomas, had similar low invasion rate (21%), but were more often non-diploid (39%). In all adenoma subgroups S-phase fractions were higher in non-diploid adenomas by an overall ratio of 2.1:1. Prolactin adenomas showed the highest (15.2%) and LH/FSH adenomas the lowest (5.6%) mean S-phase fraction. When compared to long-term follow-up, neither this parameter nor ploidy correlated with tumor size or invasiveness. Lastly, long-term follow-up showed ploidy to be an unreliable predictor of tumor persistence or recurrence.

Dementia: the University of Oklahoma autopsy experience.

The brain from 98 consecutive patients with the clinical diagnosis of dementia were examined at autopsy in a standardized fashion. Alzheimer's Disease was present in 79 of the cases, 76%, but represented the only diagnosis in 41%. Thus, almost 60% had another associated pathologic disorder. Cerebral amyloid angiopathy (CAA) represented the single largest subset, present in 25 cases. 40% were accompanied by either 1) small, microscopic infarcts or cortical scars, or 2) small collections of macrophages containing hemosiderin or small hemorrhages. CAA occurred with both atherosclerotic cortical infarcts and arteriolosclerotic subcortical pallor or lacunar infarcts. Alzheimer's Disease occurred with Diffuse Lewy Body (DLB) Disease in 13 cases. DLB Disease did not occur as a distinct entity, and thus may represent the second largest subset of Alzheimer's Disease. Both Alzheimer's Disease and DLB Disease accounted for dementia in Parkinson's Disease. Almost 25% of all cases had a disorder other than Alzheimer's Disease.

Medullomyoblastoma: case report.

This 7-year-old boy presented with a 2-week history of headache, nausea, vomiting, anorexia, lethargy, and unsteadiness of gait. Brain magnetic resonance imaging (MRI) revealed a cystic mass within the vermis of the cerebellum. A suboccipital craniectomy was performed to remove a tumor that contained primitive neuroectodermal cells with florid skeletal muscle differentiation. Immunohistochemical studies and electron microscopy confirmed the presence of both a primitive neuroectodermal component and rhabdomyoblastic differentiation, consistent with the diagnosis of medullomyoblastoma. This exceedingly rare tumor of the cerebellar vermis of children is characterized by two components: primitive neuroectodermal tumor cells and skeletal muscle. Although the histogenesis remains uncertain, advances in immunohistochemistry and electron microscopy suggest the origin of this tumor from a multipotential stem cell precursor.

Importance of sequences adjacent to the terminal tripeptide in the import of a peroxisomal Candida tropicalis protein in plant peroxisomes.

The peroxisome targeting signal (PTS) required for import of the rat acyl-CoA oxidase (AOX; EC 1.3.3.6) and the Candida tropicalis multifunctional protein (MFP) in plant peroxisomes was assessed in transgenic Arabidopsis thaliana (L.) Heynh. The native rat AOX accumulated in peroxisomes in A. thaliana cotyledons and targeting was dependent on the presence of the C-terminal tripeptide S-K-L. In contrast, the native C. tropicalis MFP, containing the consensus PTS sequence A-K-I was not targeted to plant peroxisomes. Modification of the carboxy terminus to the S-K-L tripeptide also failed to deliver the MFP to peroxisomes while addition of the last 34 amino acids of the Brassica napus isocitrate lyase, containing the terminal tripeptide S-R-M, enabled import of the fusion protein into peroxisomes. These results underline the influence of the amino acids adjacent to the terminal tripeptide of the C. tropicalis MFP on peroxisomal targeting, even in the context of a protein having a consensus PTS sequence S-K-L.

Chloroplast acclimation in leaves of Guzmania monostachia in response to high light.

Acclimation of leaves to high light (HL; 650 micromol m(-2) s(-1)) was investigated in the long-lived epiphytic bromeliad Guzmania monostachia and compared with plants maintained under low light (LL; 50 micromol m(-2) s(-1)). Despite a 60% decrease in total chlorophyll in HL-grown plants, the chlorophyll a/b ratio remained stable. Additionally, chloroplasts from HL-grown plants had a much lower thylakoid content and reduced granal stacking. Immunofluorescent labeling techniques were used to quantify the level of photosynthetic polypeptides. HL-grown plants had 30% to 40% of the content observed in LL-grown plants for the light-harvesting complex associated with photosystems I and II, the 33-kD photosystem II polypeptide, and Rubisco. These results were verified using conventional biochemical techniques, which revealed a comparable 60% decrease in Rubisco and total soluble protein. When expressed on a chlorophyll basis, the amount of protein and Rubisco was constant for HL- and LL-grown plants. Acclimation to HL involves a tightly coordinated adjustment of photosynthesis, indicating a highly regulated decrease in the number of photosynthetic units manifested at the level of the content of light-harvesting and electron transport components, the amount of Rubisco, and the induction of Crassulacean acid metabolism. This response occurs in mature leaves and may represent a strategy that is optimal for the resource-limited epiphytic niche.

The distinctive roles of five different ARC genes in the chloroplast division process in Arabidopsis.

ARC (accumulation and replication of chloroplasts) genes control different aspects of the chloroplast division process in higher plants. In order to establish the hierarchy of the ARC genes in the chloroplast division process and to provide evidence for their specific roles, double mutants were constructed between arc11, arc6, arc5, arc3 and arc1 in all combinations and phenotypically analysed. arc11 is a new nuclear recessive mutant with 29 chloroplasts compared with 120 in wild type. All the phenotypes of the double mutants are unambiguous. ARC1 down-regulates proplastid division but is on a separate pathway from ARC3, ARC5, ARC6 and ARC11. ARC6 initiates both proplastid and chloroplast division. ARC3 controls the rate of chloroplast expansion and ARC11 the central positioning of the final division plane in chloroplast division. ARC5 facilitates separation of the two daughter chloroplasts. ARC5 maps to chromosome 3 and ARC11 and ARC6 map approximately 60 cM apart on chromosome 5.