A Stability Switch for Proteins

A paper published in the September 8 issue of Cell [1] describes a generally applicable approach for chemical control of protein stability, with potential for broad use in chemical genetics

In Infancy, It’s the Extremes of Arousal That Are ‘Sticky’: Naturalistic Data Challenge Purely Homeostatic Approaches to Studying Self-Regulation

Most theoretical models of arousal/regulatory function emphasise the maintenance of homeostasis; consistent with this, most previous research into arousal has concentrated on examining individuals’ recovery following the administration of experimentally administered stressors. Here, we take a different approach: we recorded day-long spontaneous fluctuations in autonomic arousal (indexed via electrocardiogram, heart rate variability and actigraphy) in a cohort of 82 typically developing 12-month-old infants while they were at home and awake. Based on the aforementioned models, we hypothesised that extreme high or low arousal states might be more short-lived than intermediate arousal states. Our results suggested that, contrary to this, both low- and high-arousal states were more persistent than intermediate arousal states. The same pattern was present when the data were viewed over multiple epoch sizes from 1 second to 5 minutes; over 10-15-minute time-scales, high-arousal states were more persistent than low- and intermediate states. One possible explanation for these findings is that extreme arousal states have intrinsically greater hysteresis; another is that, through ‘metastatic’ processes, small initial increases and decreases in arousal can become progressively amplified over time. Rather than exclusively studying recovery, we argue that future research into self regulation during early childhood should instead examine the mechanisms through which some states can be maintained, or even amplified, over time

Coptic documents relating to the monasteries of Apa Apollo at Bawit and Titkooh in the Hermopolite nome

This thesis is concerned with the interpretation of Coptic and Greek documents from the two Coptic monasteries founded by Apa Apollo at Bawit and Titicooh in the Hermopolite nome in Egypt. It uses Coptic and Greek sources to illustrate the workings of these monasteries in the VI-IXth Centuries C.E. One hundred and six Coptic and two Greek documents are edited, twenty-one of which have been published previously. None of the documents is dated and all but a few are unprovenanced; they comprise legal texts, orders, tax demands, accounts, lists and letters which are currently in the possession of libraries, museums and private collections around the world. Many of the documents mention a monastery of Apa Apollo which is, or may be, located in the Hermopolite nome; most of them are written by or addressed to monks from that institution. One of the main aims of the thesis is to ascertain which texts relate to the Bawit and which to the Titkooh monastery of Apa Apollo. The existence of other, unconnected Egyptian monasteries named after other Apollos complicates the process of identifying the Hermopolite monasteries of Apa Apollo. I include in the thesis texts which do not mention a monastery of Apa Apollo but which appear to be related to an Hermopolite one from external evidence, such as the circumstances of their acquisition, or from internal evidence, particularly linguistic, palaeographical, prosopographical, and toponomastic data. One chapter examines documents concerned with the collection of aparchê chiefly by monks of a monastery of Apa Apollo. Other chapters investigate documents which contain two epistolary formulae which I have identified as peculiar to documents relating to the Hermopolite monasteries of Apa Apollo: "I, brother (pason) NN am writing", and "Our father is the one who writes"

Studies on the drug sensitivity and metabolism of Trichomonas vaginalis

Summary: p. i-v

X-ray studies of defects in diamond and gallium arsenide

Diamonds from mines in South Africa, and the Argyle Mine in Western Australia, have been compared using synchrotron transmission Laue photography (Laue topography), and the Argyle stones were found to be more variable in quality. By measuring the asterism of the Laue spots, quantitative estimates of lattice distortion have been made. The various types of crystal distortion, and their effects on Laue patterns, have been considered, and it has been determined that distortion in the Argyle diamonds primarily takes the form of mosaic structure. A modification of the technique of x-ray spike topography, where parts of the specimen were obscured by a tantalum screen, has been used to estimate platelet dimensions at different positions in type 1a diamonds. Direct measurements of the platelets in some of the samples have been made from transmission electron micrographs, and show that the method is reasonably reliable for platelets below about 400 A in diameter. In the range 1361.3 to 1371.3 wavenumbers, a correlation has been confirmed between 'platelet peak' position in the infrared spectrum and platelet size, in the sense of smaller wavenumbers being associated with larger platelets. Topographs of gallium arsenide wafers, used for device fabrication, have been taken. A dislocation lineage has been studied in a (100) wafer with field effect transistor arrays fabricated onto it. It has been found to cause a drop of approximately 40 mV in the pinch-off voltage of transistors it touches. The feature has been shown to have an associated Burgers vector of the 211-type, and to be accompanied by a lattice tilt in the wafer of nearly 30". Previous work in each area of investigation is reviewed, and brief introductions on diamond and gallium arsenide given, together with introductions to the techniques of topography, using both characteristic x-rays and synchrotron radiation.<p

Changes in behaviour and salivary cortisol following targeted cognitive training in typical 12-month-old infants

Previous research has suggested that early development may be an optimal period to implement cognitive training interventions, particularly those relating to attention control, a basic ability that is essential for the development of other cognitive skills. In the present study, we administered gaze-contingent training (95 minutes across 2 weeks) targeted at voluntary attention control to a cohort of typical 12-month-old children (N = 24) and sham training to a control group (N = 24). We assessed training effects on (a) tasks involving non-trained aspects of attention control: visual sustained attention, habituation speed, visual recognition memory, sequence learning and reversal learning; (b) general attentiveness (on-task behaviours during testing) and (c) salivary cortisol levels. Assessments were administered immediately following the cessation of training and at a 6-week follow-up. On the immediate post-test infants showed significantly more sustained visual attention, faster habituation and improved sequence learning. Significant effects were also found for increased general attentiveness and decreased salivary cortisol. Some of these effects were still evident at the 6-week follow-up (significantly improved sequence learning and marginally improved […] sustained attention). These findings extend the emerging literature showing that attention training is possible in infancy

Toward a Neuroscientific Understanding of Play: A Dimensional Coding Framework for Analyzing Infant-Adult Play Patterns.

Play during early life is a ubiquitous activity, and an individual's propensity for play is positively related to cognitive development and emotional well-being. Play behavior (which may be solitary or shared with a social partner) is diverse and multi-faceted. A challenge for current research is to converge on a common definition and measurement system for play - whether examined at a behavioral, cognitive or neurological level. Combining these different approaches in a multimodal analysis could yield significant advances in understanding the neurocognitive mechanisms of play, and provide the basis for developing biologically grounded play models. However, there is currently no integrated framework for conducting a multimodal analysis of play that spans brain, cognition and behavior. The proposed coding framework uses grounded and observable behaviors along three dimensions (sensorimotor, cognitive and socio-emotional), to compute inferences about playful behavior in a social context, and related social interactional states. Here, we illustrate the sensitivity and utility of the proposed coding framework using two contrasting dyadic corpora (N = 5) of mother-infant object-oriented interactions during experimental conditions that were either non-conducive (Condition 1) or conducive (Condition 2) to the emergence of playful behavior. We find that the framework accurately identifies the modal form of social interaction as being either non-playful (Condition 1) or playful (Condition 2), and further provides useful insights about differences in the quality of social interaction and temporal synchronicity within the dyad. It is intended that this fine-grained coding of play behavior will be easily assimilated with, and inform, future analysis of neural data that is also collected during adult-infant play. In conclusion, here, we present a novel framework for analyzing the continuous time-evolution of adult-infant play patterns, underpinned by biologically informed state coding along sensorimotor, cognitive and socio-emotional dimensions. We expect that the proposed framework will have wide utility amongst researchers wishing to employ an integrated, multimodal approach to the study of play, and lead toward a greater understanding of the neuroscientific basis of play. It may also yield insights into a new biologically grounded taxonomy of play interactions

Emotional valence modulates the topology of the parent-infant inter-brain network.

Emotional communication between parents and children is crucial during early life, yet little is known about its neural underpinnings. Here, we adopt a dual connectivity approach to assess how positive and negative emotions modulate the interpersonal neural network between infants and their mothers during naturalistic interaction. Fifteen mothers were asked to model positive and negative emotions toward pairs of objects during social interaction with their infants (mean age 10.3 months) whilst the neural activity of both mothers and infants was concurrently measured using dual electroencephalography (EEG). Intra-brain and inter-brain network connectivity in the 6-9 Hz range (i.e. infant Alpha band) during maternal expression of positive and negative emotions was computed using directed (partial directed coherence, PDC) and non-directed (phase-locking value, PLV) connectivity metrics. Graph theoretical measures were used to quantify differences in network topology as a function of emotional valence. We found that inter-brain network indices (Density, Strength and Divisibility) consistently revealed strong effects of emotional valence on the parent-child neural network. Parents and children showed stronger integration of their neural processes during maternal demonstrations of positive than negative emotions. Further, directed inter-brain metrics (PDC) indicated that mother to infant directional influences were stronger during the expression of positive than negative emotional states. These results suggest that the parent-infant inter-brain network is modulated by the emotional quality and tone of dyadic social interactions, and that inter-brain graph metrics may be successfully applied to examine these changes in parent-infant inter-brain network topology.UK Economic and Social Research Council (ESRC) Transforming Social Sciences Grant ES/N006461/1 (to V.L. and S.W.), a Nanyang Technological University start-up Grant M4081585.SS0 (to V.L.), a Ministry of Education (Singapore) Tier 1 grant M4012105.SS0 (V.L.) and an ESRC Future Research Leaders Fellowship ES/N017560/1 (to S.W.)

Parents mimic and influence their infant’s autonomic state through dynamic affective state matching

When we see someone experiencing an emotion, and when we experience it ourselves, common neurophysiological activity occurs [1, 2]. But although inter-dyadic synchrony, concurrent and sequential [3], has been identified, its functional significance remains inadequately understood. Specifically, how do influences of partner A on partner B reciprocally influence partner A? For example, if I am experiencing an affective state and someone matches their physiological state to mine, what influence does this have on me – the person experiencing the emotion? Here, we investigated this using infant-parent dyads. We developed miniaturised microphones to record spontaneous vocalisations and wireless autonomic monitors to record heart rate, heart rate variability and movement in infants and parents concurrently in naturalistic settings. Overall, we found that infant-parent autonomic activity did not covary across the day – but that ‘high points’ of infant arousal led to autonomic changes in the parent, and that instances where the adult showed greater autonomic responsivity were associated with faster infant quieting. Parental responsivity was higher following peaks in infant negative affect than in positive affect. Overall, parents responded to increases in their child’s arousal by increasing their own. However, when the overall arousal level of the dyad was high, parents responded to elevated child arousal by decreasing their own arousal. Our findings suggest that autonomic state matching has a direct effect on the person experiencing the affective state, and that parental co-regulation may involve both connecting, and disconnecting, their own arousal state from that of the child contingent on context

Stress reactivity speeds basic encoding processes in infants

Acute stress attenuates frontal lobe functioning and increases distractibility while enhancing subcortical processes in both human and nonhuman animals (reviewed by Arnsten [2009] Nature Reviews Neuroscience, 10(6):410–422). To date however these relations have not been examined for their potential effects in developing populations. Here, we examined the relationship between stress reactivity (infants' heart rate response to watching videos of another child crying) and infant performance on measures of looking duration and visual recognition memory. Our findings indicate that infants with increased stress reactivity showed shorter look durations and more novelty preference. Thus, stress appears to lead to a faster, more stimulus-ready attentional profile in infants. Additional work is required to assess potential negative consequences of stimulus-responsivity, such as decreased focus or distractibility. © 2016 Wiley Periodicals, Inc. Dev Psychobiol 58: 546–555, 2016