Direct Observation of Polaritonic Chemistry by Nuclear Magnetic Resonance Spectroscopy

Polaritonic chemistry is emerging as a powerful approach to modifying the properties and reactivity of molecules and materials. However, probing how the electronics and dynamics of molecular systems change under strong coupling has been challenging due to the narrow range of spectroscopic techniques that can be applied in situ. Here we develop microfluidic optical cavities for vibrational strong coupling (VSC) that are compatible with nuclear magnetic resonance (NMR) spectroscopy using standard liquid NMR tubes. VSC is shown to influence the equilibrium between two conformations of a molecular balance sensitive to London dispersion forces, revealing an apparent change in the equilibrium constant under VSC. In all compounds studied, VSC does not induce detectable changes in chemical shifts, J-couplings, or spin-lattice relaxation times. This unexpected finding indicates that VSC does not substantially affect molecular electron density distributions, and in turn has profound implications for the possible mechanisms at play in polaritonic chemistry under VSC and suggests that the emergence of collective behavior is critical.

Assessing watercourse quality using results-based indicators in an agri-environment scheme

Small watercourses are essential contributors to catchment water quality, but they continue to suffer degradation across Europe. A results-based agri-environment scheme, aimed at improving watercourse quality in Ireland, developed a rapid drainage assessment to identify point source risks. The assessment uses a scoring system based on visual indicators of nutrient and sediment risk, linking the outcomes to farmer payments. To understand how this novel drainage risk assessment relates to instream watercourse quality, we used three macroinvertebrate-based biotic indices (Q-value, Small Stream Impact Score and Proportion of Sediment Sensitive Invertebrates). Macroinvertebrate kick-sampling and physiochemical analysis were completed in May and July 2021 for 12 'At Risk' and 12 'Not at Risk' small watercourses as identified by the results-based scheme. Results show that the scheme's drainage risk assessment can identify point source risks but we found it does not directly reflect local instream quality as assessed by the biotic indices. Unexpectedly, the biotic indices showed watercourse degradation in 58% of the upstream (control) sampling points, indicating impacts not captured by the drainage risk assessment. Small watercourses displayed high heterogeneity, with significant species turnover between the sampling months. The Small Stream Impact Score was less influenced by temporal change than the Q-value index. There was a significant relationship between instream watercourse quality and sedimentation, as quantified by the Proportion of Sediment Sensitive Invertebrates. Including a measurement of instream sedimentation in the drainage assessments would improve the identification of risks and management. These results show that by linking farmer payments to the drainage risk assessments results-based payment schemes could positively contribute to improving catchment scale watercourse quality, but further work is required to capture wider sources of freshwater impacts.

'I mean, I wouldn't say I was sober': Exploring the psychosocial impact of e-scooter injuries and aligning a collaborative public health response

ISSUE ADDRESSED

E-scooters are sought after for their cost-effectiveness, sustainability, and efficiency in urban transportation. However, this popularity has been accompanied by a surge in injuries, prompting a deeper investigation into the factors influencing risk perceptions among e-scooter users.

METHODS

Using a qualitative approach, we conducted 19 interviews with those who attended an emergency department as a result of e-scooter injury. We aimed to understand the psychosocial effects of these incidents and employed thematic analysis to discern recurrent patterns in participants' experiences, focusing on alterations in daily life, community response, perception shifts, and avenues to enhance safety awareness.

RESULTS

The findings underscored significant disruptions to daily life due to injuries, demonstrating enduring impacts on lifestyle and wellbeing. Participants exhibited a perceptual shift, transitioning from perceiving e-scooters as enjoyable to viewing them as dangerous. Recommendations for enhancing safety awareness included accessible and clear safety education, pre-ride briefings, real-time safety guidance, temporal rental restrictions, and mandatory breathalysers before e-scooter use.

CONCLUSIONS

The study underscores the importance of considering not only the individual experiences and perceptions of e-scooter injuries but also the broader social context, including the night-time economy. Leveraging peer narratives and community engagement is vital to reshape risk perceptions and promote harm reduction messages. SO WHAT?: A comprehensive approach through proactive interventions and robust educational strategies is essential to foster responsible e-scooter usage and prioritise public safety.

Modulation of Polar Auxin Transport Identifies the Molecular Determinants of Source-Sink Carbon Relationships and Sink Strength in Poplar

Source-to-sink carbon (C) allocation driven by the sink strength, i.e., the ability of a sink organ to import C, plays a central role in tissue growth and biomass productivity. However, molecular drivers of sink strength have not been thoroughly characterized in trees. Auxin, as a major plant phytohormone, regulates the mobilization of photoassimilates in source tissues and elevates the translocation of carbohydrates toward sink organs, including roots. In this study, we used an 'auxin-stimulated carbon sink' approach to understand the molecular processes involved in the long-distance source-sink C allocation in poplar. Poplar cuttings were foliar sprayed with polar auxin transport modulators, including auxin enhancers (AE) (i.e., IBA and IAA) and auxin inhibitor (AI) (i.e., NPA), followed by a comprehensive analysis of leaf, stem, and root tissues using biomass evaluation, phenotyping, C isotope labeling, metabolomics, and transcriptomics approaches. Auxin modulators altered root dry weight and branching pattern, and AE increased photosynthetically fixed C allocation from leaf to root tissues. The transcriptome analysis identified highly expressed genes in root tissue under AE condition including transcripts encoding polygalacturonase and β-amylase that could increase the sink size and activity. Metabolic analyses showed a shift in overall metabolism including an altered relative abundance levels of galactinol, and an opposite trend in citrate levels in root tissue under AE and AI conditions. In conclusion, we postulate a model suggesting that the source-sink C relationships in poplar could be fueled by mobile sugar alcohols, starch metabolism-derived sugars, and TCA-cycle intermediates as key molecular drivers of sink strength.

Impact on the health service in the Top End, Northern Territory following the introduction of an electric scooter sharing service

OBJECTIVE

To investigate patients presenting to EDs following the recent introduction of a shared electric scooter (e-scooter) scheme in Northern Territory (NT).

METHODS

We conducted a prospective observational cohort study in Darwin, a regional city in NT, Australia with a population of approximately 150 000. Any patient who disclosed involvement of an e-scooter in the reason for their presentation to the ED was included. A descriptive analysis was derived for age, sex, triage time, alcohol level, injury type and the requirement of operating theatre, inpatient stay or ED discharge. Categorical variables were analysed using χ² -tests, with odds ratios (ORs), 95% confidence intervals (CIs) and P-values reported. Costing analysis to ED of attendances and inpatient hospital admissions was undertaken.

RESULTS

There were 111 presentations over the 8-month study period (January-September 2021). Forty-nine percent (n = 51) of patients were male and 51% (n = 54) were female. Extremity (n = 70) and craniofacial (n = 61) injuries were most common and approximately a quarter of patients (n = 24) required operative management for injuries sustained. Approximately half (n = 51) of patients were intoxicated and the average alcohol level of those tested was 0.18% (range 0.05-0.49%). The average cost per ED attendance was AU$777 and total cost of inpatient admissions being AU$352 255. All inpatient admissions were a result of injury while intoxicated.

CONCLUSION

Harm minimisations strategies targeting implementation of alcohol testing and penalties for riders may be able to reduce the effect that the introduction of e-scooters on the strained health system in the NT.

Repercussions of Rejecting Unwanted Advances: Gender Differences in Experience and Concern

Here we investigated how a history of experiencing unwanted advances-both sexual and romantic-impact a person's stress and strategies when rejecting future advances. In this study (N = 465; 71% women), women reported experiencing unwanted advances earlier in life compared to men, and these women were more likely to have greater worry over such advances. Additionally, women tended to worry more than men about the repercussions of rejecting these advances (e.g., being hit, being yelled at). Lastly, women were more likely to employ a myriad of strategies (e.g., run away, call a friend) to ensure their safety when rejecting an advance. In contrast, men were more likely to remain friends with the rejected person. Ultimately, women have to deal with rejecting advances at an early age and this early onset has consequences for future dating.

Experimental and cross-cultural evidence that parenthood and parental care motives increase social conservatism

Differences in attitudes on social issues such as abortion, immigration and sex are hugely divisive, and understanding their origins is among the most important tasks facing human behavioural sciences. Despite the clear psychological importance of parenthood and the motivation to provide care for children, researchers have only recently begun investigating their influence on social and political attitudes. Because socially conservative values ostensibly prioritize safety, stability and family values, we hypothesized that being more invested in parental care might make socially conservative policies more appealing. Studies 1 (preregistered; n = 376) and 2 (n = 1924) find novel evidence of conditional experimental effects of a parenthood prime, such that people who engaged strongly with a childcare manipulation showed an increase in social conservatism. Studies 3 (n = 2610, novel data from 10 countries) and 4 (n = 426 444, World Values Survey data) find evidence that both parenthood and parental care motivation are associated with increased social conservatism around the globe. Further, most of the positive association globally between age and social conservatism is accounted for by parenthood. These findings support the hypothesis that parenthood and parental care motivation increase social conservatism.

Effect of Plyometric Jump Training on Skeletal Muscle Hypertrophy in Healthy Individuals: A Systematic Review With Multilevel Meta-Analysis

Objective: To examine the effect of plyometric jump training on skeletal muscle hypertrophy in healthy individuals.

Methods: A systematic literature search was conducted in the databases PubMed, SPORTDiscus, Web of Science, and Cochrane Library up to September 2021.

Results: Fifteen studies met the inclusion criteria. The main overall finding (44 effect sizes across 15 clusters median = 2, range = 1–15 effects per cluster) indicated that plyometric jump training had small to moderate effects [standardised mean difference (SMD) = 0.47 (95% CIs = 0.23–0.71); p < 0.001] on skeletal muscle hypertrophy. Subgroup analyses for training experience revealed trivial to large effects in non-athletes [SMD = 0.55 (95% CIs = 0.18–0.93); p = 0.007] and trivial to moderate effects in athletes [SMD = 0.33 (95% CIs = 0.16–0.51); p = 0.001]. Regarding muscle groups, results showed moderate effects for the knee extensors [SMD = 0.72 (95% CIs = 0.66–0.78), p < 0.001] and equivocal effects for the plantar flexors [SMD = 0.65 (95% CIs = −0.25–1.55); p = 0.143]. As to the assessment methods of skeletal muscle hypertrophy, findings indicated trivial to small effects for prediction equations [SMD = 0.29 (95% CIs = 0.16–0.42); p < 0.001] and moderate-to-large effects for ultrasound imaging [SMD = 0.74 (95% CIs = 0.59–0.89); p < 0.001]. Meta-regression analysis indicated that the weekly session frequency moderates the effect of plyometric jump training on skeletal muscle hypertrophy, with a higher weekly session frequency inducing larger hypertrophic gains [β = 0.3233 (95% CIs = 0.2041–0.4425); p < 0.001]. We found no clear evidence that age, sex, total training period, single session duration, or the number of jumps per week moderate the effect of plyometric jump training on skeletal muscle hypertrophy [β = −0.0133 to 0.0433 (95% CIs = −0.0387 to 0.1215); p = 0.101–0.751].

Conclusion: Plyometric jump training can induce skeletal muscle hypertrophy, regardless of age and sex. There is evidence for relatively larger effects in non-athletes compared with athletes. Further, the weekly session frequency seems to moderate the effect of plyometric jump training on skeletal muscle hypertrophy, whereby more frequent weekly plyometric jump training sessions elicit larger hypertrophic adaptations.

Multiple Discrimination and Its Consequences for the Mental Health of Ethnic Minorities

Discrimination is a violation of human rights. The Universal Declaration of Human Rights proclaims in Art. 1 the equality of all human beings without distinction as to race, colour, sex, sexual orientation, religion, age or health. International law assigns three main characteristics to discrimination: disadvantageous treatment, based on unlawful grounds, and lack of reasonable and objective justification. Thus, it must be based on an unlawful characteristic: Ethnicity, religion, national or social origin, language, physical appearance, descent, gender, sexual orientation, age or disability. A growing body of literature has recognized health disparities and has investigated the relationship between discrimination and poor health outcomes. Ethnic minority groups across the world face social and psychological challenges linked to their minority status, often involving discrimination. Furthermore, cumulative exposure to racial discrimination has incremental negative long-term effects on the mental health of ethnic minority people.Studies that examine exposure to discrimination only at one point in time may underestimate the contribution of racism to poor health. Lower patient-centered care was associated with higher perceptions of discrimination, despite experiences of continuous discrimination or discrimination experienced as different types. Further, dissatisfaction with care was associated with discrimination, particularly when experienced in various forms. These findings reinforce a need for patient-provider communication that is inclusive and eliminates perceptions of discrimination and bias, increases patient-centeredness, and improves overall clinical care. Additionally, these results stress the need for more research investigating the relationship between discrimination and outcomes in patients, as perceived discrimination manifests as a significant barrier to effective disease management.

Disclosure

No significant relationships.

108 COMBATTING CONFUSION: SIMULATION-BASED MEDICAL EDUCATION FOR DEALING WITH DELIRIUM

Background

Delirium is a complex, costly, and common clinical syndrome. Simulation-based medical education has been shown to be effective in enhancing the confidence, knowledge and skills of healthcare professionals in the management of delirium. We piloted an inter-professional education simulation on delirium in an acute hospital setting. The session’s design was informed by participating in ‘Sim Stars’, a regional simulation development competition.

Methods

We iteratively developed a low-fidelity simulation scenario on the recognition, prevention and management of delirium. The resulting simulation was piloted during an hour-long multidisciplinary departmental teaching session in a lecture hall setting. A candidate was asked to review an acutely confused patient (played by a ‘confederate’) on call. The candidate was expected to screen for delirium using the 4AT tool; assess for possible causes of delirium; and implement an appropriate management plan. After the session, qualitative feedback from the participants and audience was sought.

Results

This pilot simulation included one candidate (medical Senior House Officer); two confederates (Consultant Geriatrician, Advanced Nurse Practitioner); two facilitators (Consultant Geriatrician, Advanced Nurse Practitioner); and an audience of 17 members. Feedback indicated that learners and trainers found this a helpful and enjoyable pedagogical method. Areas for improvement were highlighted, including providing advance notice for learners of the topic to be simulated; a more structured introduction defining the learning outcomes and declaring a ‘blame free’ environment; improved script for the patient confederate; and that having a team of learners (rather than specialists) to play ‘confederates’ may help improve team-building and reduce learner anxiety.

Conclusion

This pilot simulation received positive appraisals from the team, and plans are underway to incorporate simulation more regularly into departmental teaching. Suggestions to improve future simulations were welcomed. Given its low-fidelity, this scenario can easily be used at any site for simulation-based training.

A landscape classification map of Ireland and its potential use in national land use monitoring

This study presents a novel landscape classification map of the Republic of Ireland and is the first to identify broad landscape classes by incorporating physiographic and land cover data. The landscape classification responds to commitments to identify and classify the Irish landscape as a signatory to the European Landscape Convention. The methodology applied a series of clustering iterations to determine an objective multivariate classification of physiographic landscape units and land cover datasets. The classification results determined nine statistically significant landscape classes and the development of a landscape classification map at a national scale. A statistical breakdown of land cover area and diversity of each class was interpreted, and a comparison was extended using independent descriptive variables including farmland use intensity, elevation, and dominant soil type. Each class depicts unique spatial and composition characteristics, from coastal, lowland and elevated, to distinct and dominating land cover types, further explained by the descriptive variables. The significance of individual classes and success of the classification is discussed with particular reference to the wider applicability of the map. The transferability of the methodology to other existing physiographic maps and environmental datasets to generate new landscape classifications is also considered. This novel work facilitates the development of a strategic framework to efficiently monitor, compare and analyse ecological and other land use data that is spatially representative of the distribution and extent of land cover in the Irish countryside.

Participation of Glutamatergic Ionotropic Receptors in Excitotoxicity: The Neuroprotective Role of Prolactin

Glutamate (Glu) is known as the main excitatory neurotransmitter in the central nervous system. It can trigger a series of processes ranging from synaptic plasticity to neurophysiological regulation. To carry out its functions, Glu acts via interaction with its cognate receptors, which are ligand-dependent. Glutamatergic receptors include ionotropic and metabotropic categories. The first allows the passage of ions through the postsynaptic membrane, while the metabotropic subtype activates signaling cascades through second messengers. It is well known that an excess of extracellular Glu concentration induces overstimulation of ionotropic glutamatergic receptors (iGluRs), causing the excitotoxicity phenomenon that leads to neuronal damage and cell death. Excitotoxicity plays a crucial role in different brain pathologies such as brain strokes, epilepsy and neurodegenerative disorders. However, until now, there are no effective neuroprotective compounds to prevent or rescue neurons from excitotoxicity. Thus, the continuous elucidation of the molecular mechanisms underlying excitotoxicity in order to prevent damage or neuronal death is necessary. Therefore, the aim of this review was to summarize the current knowledge regarding iGluRs, while describing their structures and molecular mechanisms of action, including their role in excitotoxicity, as well as the current strategies to reduce excitotoxic damage. Particularly, strategies mediated by prolactin, a somatotropin family-related hormone that displays a significant neuroprotective effect against both Glu and kainic acid-induced excitotoxicity in the hippocampus, are described. Finally, the role of prolactin as a possible molecule in the treatment of excitotoxicity in neurological diseases is discussed.

Assessment of semi-natural habitats and landscape features on Irish farmland: New insights to inform EU Common Agricultural Policy implementation

Concerns over the loss of biodiversity and ecosystem services in farmland have prompted the development of agri-environment policy measures aimed at reducing farming pressure and maintaining semi-natural habitats in farmed landscapes. However, further knowledge is needed to guarantee successful agri-environment measures implementation. The current study assessed the quantity and the quality of semi-natural habitats in farms across a gradient of farming intensities in two contrasting regions in Ireland. Policy protection seemed fundamental for semi-natural habitats preservation. Habitats not protected by agricultural policy relied on extensive farming and are in danger of disappearing if they are intensified or abandoned. Due to the lack of policy incentives for habitat quality, no correlations were found between farming intensity and share of semi-natural habitats with habitat quality. Therefore, extensive farming and retention of habitats alone may not reverse the decline of farmland quality and biodiverisity and, thus, measures incentivising the environmental quality may be more successful.

Core Minimal Datasets to Advance Clinical Research for Priority Epidemic Diseases

The Ebola virus disease outbreak in west Africa has prompted significant progress in responding to the clinical needs of patients affected by emerging infectious disease outbreaks. Among the noteworthy successes of vaccine trials, and the commendable efforts to implement clinical treatment trials during Ebola outbreaks, we should also focus on strengthening the collection and curation of epidemiological and observational data that can improve the conception and design of clinical research.

Hedgerow typology and condition analysis to inform greenway design in rural landscapes

Over the past decades, Western European hedgerows have been declining as a result of land use change. Disused infrastructure corridors such as railways and tramways can host a range of existing and returning semi-natural habitats, including extensive hedgerow networks. However, long term corridor abandonment can result in network deterioration to gappy hedgerows, lines of trees and eventually individual scrub features. The loss of hedgerows results in the loss of many ecosystem services, habitat for species and landscape connectivity. This highlights an increasing need to find innovative solutions to recognise and appropriately maintain these hedgerow networks. European Greenways typically 'upcycle' disused infrastructure transport corridors for multi-use, non-motorised recreational public infrastructure. The potential for European greenways to maintain and restore hedgerows is of interest as a novel planning mechanism for enhancing green infrastructure in general. The aim of this study is to inform Greenway design and management through the evaluation of hedgerow significance (historical, ecological and landscape), condition and composition within a rural European Greenway landscape context. 81 hedgerows were sampled along a 70 km proposed Greenway route traversing a range of extensive and intensive landscapes. Hedgerows were surveyed using a rapid field score sheet which enabled significance and condition scoring. A hedgerow typology was subsequently developed based on species composition assemblages. Hedgerows were found to be highly ecologically significant and species rich throughout the route. On-going land use intensification was evident as significant sections of the former railway corridor were subsumed into intensive agriculture and afforestation. Management recommendations need to be adapted to the particular hedgerow group and surrounding landscape context, and take into account the varied requirements of different taxonomic groups. The study findings show Greenways have the potential to act as multi-functional green infrastructure (accomplishing both ecological and recreational objectives) through informed design to reinforce their nature conservation role and recognising hedgerows as integral landscape feature of Greenway corridor, at local level and as part of a wider European network.

Landscape typology and ecological connectivity assessment to inform Greenway design

European Greenway developments typically 'upcycle' disused transport corridors for multi-use, non-motorised public infrastructure. The linear and relatively undisturbed nature of these disused infrastructures means many currently function as high quality ecological corridors. Corridors providing connectivity among habitat patches can mitigate the effects of fragmentation on biodiversity, allowing species dispersal throughout the landscape matrix. The sustainable integration of Greenway infrastructure and ecological corridor functions requires consideration during design, development and maintenance stages, taking into account surrounding landscape composition and connectivity. This paper presents a method to characterise a proposed Greenway corridor landscape, focusing on habitat composition and ecosystems connectivity. Morphological Spatial Pattern Analysis (MSPA) was used to comprehensively describe the structural connectivity of linear and spatial habitats occurring within the study area. A subsequent multivariate classification of structural connectivity and habitat data determined six distinctive landscape characters. Interpretation of these landscape characters highlights the principal habitat compositions and connectivity conditions in terms of habitat core, links and potential linkages. For example one landscape was intensified, yet retained high woodland connectivity, while another diverse habitat landscape supported little connectivity for woodland and grasslands. The results of this study suggest significant opportunities exist to enhance European landscape connectivity through informed Greenway development. Crucial habitat linkages can be optimised along Greenway infrastructure, contributing towards the realisation of European Greenways as Green Infrastructure and true sustainable projects.

Tilting a ground-state reactivity landscape by vibrational strong coupling

Many chemical methods have been developed to favor a particular product in transformations of compounds that have two or more reactive sites. We explored a different approach to site selectivity using vibrational strong coupling (VSC) between a reactant and the vacuum field of a microfluidic optical cavity. Specifically, we studied the reactivity of a compound bearing two possible silyl bond cleavage sites—Si–C and Si–O, respectively—as a function of VSC of three distinct vibrational modes in the dark. The results show that VSC can indeed tilt the reactivity landscape to favor one product over the other. Thermodynamic parameters reveal the presence of a large activation barrier and substantial changes to the activation entropy, confirming the modified chemical landscape under strong coupling.

IFT80 mutations cause a novel complex ciliopathy phenotype with retinal degeneration

Ciliopathies, a growing pleotropic class of diseases due to mutations in genes that play an important role in primary cilia function. These highly conserved organelles are key to cell signaling. We now know, that mutations in one gene may lead to more than one ciliopathy phenotype and that one ciliopathy phenotype may be due to mutations in more than one gene. We studied the case of a female child with a novel ciliopathy phenotype and identified two novel mutations in the gene IFT80. Previously, mutations in IFT80 have been associated with a very narrow rib cage and failure of the lungs. Bone anomalies are also part of this IFT80-condition but with no vision problems documented. Our case had none of the features known to be associated with IFT80 mutations and had retinal degeneration (RD). This work broadens the IFT80-phenotype spectrum and also shows RD can be a feature of many ciliopathies.

Health promotion through sport: international sport federations’ priorities, actions and opportunities

Objective

To identify areas of priority and activity for international sportsfederations (IFs) with respect to athlete health and safety, and global health. Results serve to direct the work of the Association of Summer Olympic IF Medical and Scientific Consultative Group, the International Olympic Committee and to influence IFs’ planning and priorities.

Methods

The 28 IFs participating in the Summer Olympic Games (2016) were asked to rank the relative importance of 11 health-related topics and to report their activities or research initiatives on 27 identified topics using an electronic survey. A comparison with a similar survey (2012) was made.

Results

The response rate was 100%. In general, the ‘fight against doping’ had the highest priority followed by ‘image as a safe sport’. The topics with the lowest importance ratings were ‘increasing the number of elite athletes’, and ‘health of the general population’. Despite ranking ‘health of your athletes,’ as a top priority, IFs are not addressing all aspects of athlete health. In comparison with 2012, there was a significant decrease in priority for IFs is ‘health of the general population’.

Conclusion

Despite the widespread knowledge of the importance of the promotion of physical activity (sport) on global health, the decreasing priority and programming of the IFs on physical activity promotion is concerning. Although IFs have prioritised the protection of the health of elite athletes, there are gaps in programming demonstrating that IFs are missing important areas of athlete health. Improving recreational athlete health programming could also benefit population health as well as improve IF fan base and sport participation.

Improvements to sample processing and measurement to enable more widespread environmental application of tritium

Previous measurements have demonstrated the wealth of information that tritium (T) can provide on environmentally relevant processes. We present modifications to sample preparation approaches that enable T measurement by proportional counting on small sample sizes equivalent to 120mg of water and demonstrate the accuracy of these methods on a suite of standardized water samples. We identify a current quantification limit of 92.2 TU which, combined with our small sample sizes, correlates to as little as 0.00133Bq of total T activity. This enhanced method should provide the analytical flexibility needed to address persistent knowledge gaps in our understanding of both natural and artificial T behavior in the environment.

Mechanisms of Stain Formation on Teeth, in Particular Associated with Metal Ions and Antiseptics

Much has been written on the subject of extrinsic tooth discoloration, but, except when the pigment is intentionally applied, the etiologies and mechanisms are poorly understood. Extrinsic stains have been classified as non-metallic or metallic. The pigment usually lies not on or in the dental tissues, but in surface deposits, particularly the acquired pellicle layer and at sites receiving limited cleaning. Whether pigments absorb, adsorb, or chemically interact with dental surfaces is unclear. Some stains merely seem to reflect the color of the apparent source, whereas others have been ascribed to a secondary chemical alteration of a substance at the tooth or pellicle surface. Theories of chromogenic bacteria and formation of metal sulfides are frequently propounded but without clear supportive evidence. Staining by cationic antiseptics and, to a lesser extent, metal salts has attracted research interest. Chlorhexidine and other cationic antiseptics, it is hypothesized, may catalyze browning reactions or facilitate metal sulfide formation in pellicle. Controlled clinical studies have repeatedly shown that dental and mucosal staining associated with the use of chlorhexidine and some metal salts is dependent upon volunteers' imbibing reasonable quantities of chromogenic beverages, such as tea. However, it must be appreciated that cationic antiseptics and polyvalent metals can precipitate chromogenic material from a large range of dietary compounds. The control of dental staining, at least that associated with chlorhexidine, can be achieved both in vitro and in vivo by the use of oxidizing agents which appear to remove the stain physically from the surfaces.

Variation in Responses to Sprint Training in Male Youth Athletes: A Meta-analysis

The trainability of youths and the existence of periods of accelerated adaptation to training have become key subjects of debate in exercise science. The purpose of this meta-analysis was to characterise youth athletes' adaptability to sprint training across PRE-, MID-, and POST-peak height velocity (PHV) groups. Effect sizes were calculated as a measure of straight-line sprinting performance with studies qualifying based on the following criteria: (a) healthy male athletes who were engaged in organised sports; (b) groups of participants with a mean age between 10 and 18 years; (c) sprint training intervention duration between 4 and 16 weeks. Standardised mean differences showed sprint training to be moderately effective (Effect size=1.01, 95% confidence interval: 0.43-1.59) with adaptive responses being of large and moderate magnitude in the POST- (ES=1.39; 0.32-2.46) and MID- (ES=1.15; 0.40-1.9) PHV groups respectively. A negative effect size was found in the PRE group (ES=-0.18; -1.35-0.99). Youth training practitioners should prescribe sprint training modalities based on biological maturation status. Twice weekly training sessions should comprise up to 16 sprints of around 20 m with a work-to-rest ratio of 1:25 or greater than 90 s.

An implantable 64-channel neural interface with reconfigurable recording and stimulation

Next generation implantable medical devices will have the potential to provide more precise and effective therapies through adaptive closed-loop controllers that combine sensing and stimulation across larger numbers of electrode channels. A major challenge in the design of such devices is balancing increased functionality and channel counts with the miniaturization required for implantation within small anatomical spaces. Customized therapies will require adaptive systems capable of tuning which channels are sensed and stimulated to overcome variability in patient-specific needs, surgical placement of electrodes, and chronic physiological responses. In order to address these challenges, we have designed a miniaturized implantable fully-reconfigurable front-end system that is integrated into the distal end of an 8-wire lead, enabling up to 64 electrodes to be dynamically configured for sensing and stimulation. Full reconfigurability is enabled by two custom 32×2 cross-point switch (CPS) matrix ASICs which can route any electrode to either an amplifier with reprogrammable bandwidth and integrated ADC or to one of two independent stimulation channels that can be driven through the lead. The 8-wire circuit includes a digital interface for robust communication as well as a charge-balanced powering scheme for enhanced safety. The system is encased in a hermetic package designed to fit within a 14 mm bur-hole in the skull for neuromodulation of the brain, but could easily be adapted to enhance therapies across a broad spectrum of applications.

Neural signal processing and closed-loop control algorithm design for an implanted neural recording and stimulation system

A fully autonomous intracranial device is built to continually record neural activities in different parts of the brain, process these sampled signals, decode features that correlate to behaviors and neuropsychiatric states, and use these features to deliver brain stimulation in a closed-loop fashion. In this paper, we describe the sampling and stimulation aspects of such a device. We first describe the signal processing algorithms of two unsupervised spike sorting methods. Next, we describe the LFP time-frequency analysis and feature derivation from the two spike sorting methods. Spike sorting includes a novel approach to constructing a dictionary learning algorithm in a Compressed Sensing (CS) framework. We present a joint prediction scheme to determine the class of neural spikes in the dictionary learning framework; and, the second approach is a modified OSort algorithm which is implemented in a distributed system optimized for power efficiency. Furthermore, sorted spikes and time-frequency analysis of LFP signals can be used to generate derived features (including cross-frequency coupling, spike-field coupling). We then show how these derived features can be used in the design and development of novel decode and closed-loop control algorithms that are optimized to apply deep brain stimulation based on a patient's neuropsychiatric state. For the control algorithm, we define the state vector as representative of a patient's impulsivity, avoidance, inhibition, etc. Controller parameters are optimized to apply stimulation based on the state vector's current state as well as its historical values. The overall algorithm and software design for our implantable neural recording and stimulation system uses an innovative, adaptable, and reprogrammable architecture that enables advancement of the state-of-the-art in closed-loop neural control while also meeting the challenges of system power constraints and concurrent development with ongoing scientific research designed to define brain network connectivity and neural network dynamics that vary at the individual patient level and vary over time.

Predicting local field potentials with recurrent neural networks

We present a Recurrent Neural Network using LSTM (Long Short Term Memory) that is capable of modeling and predicting Local Field Potentials. We train and test the network on real data recorded from epilepsy patients. We construct networks that predict multi-channel LFPs for 1, 10, and 100 milliseconds forward in time. Our results show that prediction using LSTM outperforms regression when predicting 10 and 100 millisecond forward in time.

Packaging Architecture for an Implanted System that Monitors Brain Activity and Applies Therapeutic Stimulation

Deep brain stimulation therapies for Parkinson's disease utilize hardware that, from a packaging perspective, resembles those that are used in cardiac pacemakers. A hermetic package that contains stimulation electronics and a primary battery supply is implanted under the scalp into a recess formed in the skull. Stimulation probes, each with up to four electrodes, are inserted into the brain and connected to the electronics package via a plug and cable system. Unlike single-target devices such as cochlear implants and pacemakers, achieving this type of neuropsychiatric therapy requires the ability to record and stimulate in multiple and distributive areas of the brain, both cortical and subcortical. By contrast, the closed-loop neural stimulator being developed under the DARPA SUBNETS program utilizes probes, each of which carries up to 64 electrodes that can be switched between recording and stimulation functions. This capability necessitates locating low-noise amplifiers, switching and communication electronics in close proximity to each probe site. Each of these satellite electronics packages requires 10 electrical connections to the hub package, which significantly increases the complexity of the interconnect system relative to the current practice. The power requirements of this system preclude the use of a primary battery supply, so a large lithium ion battery is used, with a recharging coil and electronics. The hub system is composed of a connector header, electronics package, and battery pack that are fabricated separately and are interconnected by a flex circuit board, to allow it to conform to the skull for implanting. The standardized feedthrough substrate on the satellite, which can interface with multiple types of electrodes, along the system being reconfigurable, enables our architecture to support this new clinical research. It also allows the clinician to select satellite-electrode system based on a patient's needs, thus providing a customized, patient-specific therapeutic system. In this article, we have described the various packaging components of this system and the design considerations that drove our technology choices.

Package architecture and component design for an implanted neural stimulator with closed loop control

An implanted neural stimulator with closed loop control requires electrodes for stimulation pulses and recording neuron activity. Our system features arrays of 64 electrodes. Each electrode can be addressed through a cross bar switch, to enable it to be used for stimulation or recording. This electrode switch, a bank of low noise amplifiers with an integrated analog to digital converter, power conditioning electronics, and a communications and control gate array are co-located with the electrode array in a 14 millimeter diameter satellite package that is designed to be flush mounted in a skull burr hole. Our system features five satellite packages connected to a central hub processor-controller via ten conductor cables that terminate in a custom designed, miniaturized connector. The connector incorporates features of high reliability, military grade devices and utilizes three distinct seals to isolate the contacts from fluid permeation. The hub system is comprised of a connector header, hermetic electronics package, and rechargeable battery pack, which are mounted on and electrically interconnected by a flexible circuit board. The assembly is over molded with a compliant silicone rubber. The electronics package contains two antennas, a large coil, used for recharging the battery and a high bandwidth antenna that is used to download data and update software. The package is assembled from two machined alumina pieces, a flat base with brazed in, electrical feed through pins and a rectangular cover with rounded corners. Titanium seal rings are brazed onto these two pieces so that they can be sealed by laser welding. A third system antenna is incorporated in the flexible circuit board. It is used to communicate with an externally worn control package, which monitors the health of the system and allows both the user and clinician to control or modify various system function parameters.