Determining the neurotransmitter concentration profile at active synapses

Establishing the temporal and concentration profiles of neurotransmitters during synaptic release is an essential step towards understanding the basic properties of inter-neuronal communication in the central nervous system. A variety of ingenious attempts has been made to gain insights into this process, but the general inaccessibility of central synapses, intrinsic limitations of the techniques used, and natural variety of different synaptic environments have hindered a comprehensive description of this fundamental phenomenon. Here, we describe a number of experimental and theoretical findings that has been instrumental for advancing our knowledge of various features of neurotransmitter release, as well as newly developed tools that could overcome some limits of traditional pharmacological approaches and bring new impetus to the description of the complex mechanisms of synaptic transmission

A well-defined readily releasable pool with fixed capacity for storing vesicles at calyx of Held.

The readily releasable pool (RRP) of vesicles is a core concept in studies of presynaptic function. However, operating principles lack consensus definition and the utility for quantitative analysis has been questioned. Here we confirm that RRPs at calyces of Held from 14 to 21 day old mice have a fixed capacity for storing vesicles that is not modulated by Ca2+. Discrepancies with previous studies are explained by a dynamic flow-through pool, established during heavy use, containing vesicles that are released with low probability despite being immediately releasable. Quantitative analysis ruled out a posteriori explanations for the vesicles with low release probability, such as Ca2+-channel inactivation, and established unexpected boundary conditions for remaining alternatives. Vesicles in the flow-through pool could be incompletely primed, in which case the full sequence of priming steps downstream of recruitment to the RRP would have an average unitary rate of at least 9/s during heavy use. Alternatively, vesicles with low and high release probability could be recruited to distinct types of release sites; in this case the timing of recruitment would be similar at the two types, and the downstream transition from recruited to fully primed would be much faster. In either case, further analysis showed that activity accelerates the upstream step where vesicles are initially recruited to the RRP. Overall, our results show that the RRP can be well defined in the mathematical sense, and support the concept that the defining mechanism is a stable group of autonomous release sites

Decision-making of English Netball Superleague umpires: Contextual and dispositional influences

Objectives. The decisions made by officials have a direct bearing on the outcomes of competitive sport contests. In an exploratory study, we examine the interrelationships between the decisions made by elite netball umpires, the potential contextual and environmental influences (e.g., crowd size), and the umpires’ dispositional tendencies – specifically, their propensity to deliberate and ruminate on their decisions. Design/Method. Filmed footage from 60 England Netball Superleague matches was coded using performance analysis software. We measured the number of decisions made overall, and for home and away teams; league position; competition round; match quarter; and crowd size. Additionally, 10 umpires who officiated in the matches completed the Decision-Specific Reinvestment Scale (DSRS). Results. Regression analyses predicted that as home teams’ league position improved the number of decisions against away teams increased. A model comprising competition round and average league position of both teams predicted the number of decisions made in matches, but neither variable emerged as a significant predictor. The umpire analyses revealed that greater crowd size was associated with an increase in decisions against away teams. The Decision Rumination factor was strongly negatively related to the number of decisions in Quarters 1 and 3, this relationship was driven by fewer decisions against home teams by umpires who exhibited higher Rumination subscale scores. Conclusions. These findings strengthen our understanding of contextual, environmental, and dispositional influences on umpires’ decision-making behaviour. The tendency to ruminate upon decisions may explain the changes in decision behaviour in relation to the home team advantage effect

Studi Sumber Timbulan Sampah Di Pasar Daya Makassar

Abstrak\ud Peningkatan jumlah timbulan sampah dipengaruhi oleh aktifitas pengunjung dan penjual di Pasar Daya Makassar. Apabila tidak diimbangi dengan sistem pengelolaan yang tepat, dapat menghambat aktifitas di perdagangan dan menjadi permasalahan yang sulit diselesaikan. Kebijakan pihak PD Pasar dalam pengelolaan sampah saat ini hanya menerapkan singgle method, yaitu wadah-kumpul-angkut-buang, sampah sepenuhnya dibuang ke Tempat Pembuangan Akhir (TPA). Untuk mencegah kebuntuan sistem pengelolaan sampah, perlu dikembangkan metode-metode pengelolaan alternatif guna mengoptimalkan proses pengelolaan sampah yang dihasilkan di Pasar Daya Makassar, sehingga dapat mengurangi volume sampah yang masuk ke TPA dan memaksimalkan penggunaan kembali material serta penghematan terhadap biaya pengelolaan sampah Pasar. Adapun pengambilan dan pengukuran sampel sampah dengan menggunakan metode SNI 19-3964-1994 (metode pengambilan dan pengukuran contoh timbulan dan komposisi sampah perkotaan). Pengambilan sampel sampah dilakukan di tiap titik yang sudah ditentukan. Penelitian ini diharapkan untuk mendapatkan jenis sampah yang terdapat di Pasar Daya Makassa

The Effect of Blurred Perceptual Training on the Decision Making of Skilled Football Referees

When judging ambiguous foul situations in football (soccer), referees must attune to the kinematic characteristics inherent in genuine fouls to ensure that they can (i) recognize when a foul has taken place, and (ii) discriminate the presence of deceptive intent on the part of the tackled player. The aim of this study was to determine whether perceptual training that removes superficial visual information would improve the decision-making performance of football referees. Two groups of skilled referees judged ambiguous foul situations on video before and after a training intervention that involved adjudicating foul situations. During the training phase, participants in a blurred-footage training group watched digitally altered, blurred videos that removed superficial visual information, whilst participants in a normal-footage control group viewed the same videos without blur (i.e., with the superficial information present). We hypothesized that blurred-training would train referees to ignore superficial visual information and instead focus on the basic kinematic movements that would better reveal the true nature of the inter-personal interaction. Consistent with this idea, training with blurred footage resulted in a positive change in response accuracy from pre to post-test when compared with normal-footage training. This improvement could not be explained on the basis of changes in response time or bias, but instead reflected a change in the sensitivity to genuine fouls. These findings provide a promising indication of the potential efficacy of blurred-footage training for referees to attune to the kinematic information that characterizes a foul. Blurred training might offer an innovative means of enhancing the decision-making performance of football referees via perceptual training

Observational Behavior Assessment for Psychological Competencies in Police Officers:A Proposed Methodology for Instrument Development

This paper proposes and showcases a methodology to develop an observational behavior assessment instrument to assess psychological competencies of police officers. We outline a step-by-step methodology for police organizations to measure and evaluate behavior in a meaningful way to assess these competencies. We illustrate the proposed methodology with a practical example. We posit that direct behavioral observation can be key in measuring the expression of psychological competence in practice, and that psychological competence in practice is what police organizations should care about. We hope this paper offers police organizations a methodology to perform scientifically informed observational behavior assessment of their police officers’ psychological competencies and inspires additional research efforts into this important area

Criteria for the high quality training of police officers

Training time is a scarce commodity in the police context. It is therefore important to squeeze as much learning out of the available time as possible. High quality training is, however, not a given in the police domain. Police instructors are generally highly motivated to do well and feel a strong sense of responsibility to equip their trainees with adequate skills. However, didactical and pedagogical skills are still often the neglected child in training. Studies have shown there is much to improve in the training of officers. The authors wrote this chapter with police training practitioners in mind and hope the criteria will support their practice and help them to substantiate their practical expertise and motivation to deliver great training with scientifically grounded criteria. They provide didactical criteria for high quality training in the police domain. Their underpinning view of learning is that it is a process that leads to relatively stable changes in behaviour (potential) as a result of specific interactions with the environment. They consider skills to be learned when they are sustained over some time after training (retention) and when they can be applied in various situations (transfer). The criteria they present are based on research on skill acquisition, motor learning, performing under pressure, and motivation. As such they are mostly (but not solely) applicable to the training of perceptual motor skills such as use-of-force and de-escalation training, decision making and acting, and integrated skills training, such as scenario training. The criteria can be used in the design or preparation of training, serve as a guidance for instructors during training sessions, and form criteria to evaluate and monitor the didactical quality of sessions.</p

The impact of community learning during a participatory nursing research project

Background: Community learning is one approach to promote research competencies and to involve nurses and nursing students in research. This study examines the impact of community learning accord-ing to participants-both those inside and outside the community-in a joint nursing research project at a hospital. Method: A qualitative design was se-lected using a participatory approach. Data were col-lected through semistructured interviews, reflections, conversations, and patient input during 2 academic years. Results: Thematic analysis showed 11 themes, which were organized into three clusters: realization, transformation, and influencing factors. Participants perceived changes in practice and described how their perspectives have changed on care, education, and research. Reconsiderations led to some new or revised strategies, and influencing factors were asso-ciated with the contemporary context, degree of in-volvement, and design/facilitation. Conclusion: The impact of community learning emerged and extended beyond community boundaries, and the indicated in-fluencing factors must be taken into account. [J Contin Educ Nurs. 2023;54(3):131-144.]Prevention, Population and Disease management (PrePoD)Public Health and primary car

Presynaptic ATP Decreases During Physiological-Like Activity in Neurons Tuned for High-Frequency Transmission

Recent evidence indicates that the concentration of ATP remains stable during neuronal activity due to activity-dependent ATP production. However, the mechanisms of activity-dependent ATP production remain controversial. To stabilize the ATP concentration, feedforward mechanisms, which may rely on calcium or the sodium-potassium pump, do not require changes in the ATP and ADP concentrations. On the other hand, feedback mechanisms could be triggered by changes in the concentration of the adenine nucleotides. To test the possibility of feedback mechanisms, we quantified the ATP concentration in presynaptic terminals during synaptic activity in acute brain slices from mice stably expressing a genetically encoded ATP sensor. We first focused on the cerebellar mossy fiber bouton (cMFB) as a large presynaptic terminal that is specialized for high-frequency synaptic transmission. At physiological temperature and metabolite concentrations, the resting ATP concentration was in the range of approximately 2.5–2.7 mM. During strong, presumably non-physiological activity, the ATP concentration decreased within a few seconds. Experiments with blockade of ATP production indicated that ATP production increased ~10-fold during neuronal activity. Weaker stimulation resembling physiological activity at this synapse caused a decrease in ATP concentration by ~150 μM. We found similar results with in vivo-recorded spike sequences at the calyx of Held, another central glutamatergic synapse tuned for high-frequency synaptic activity. At conventional small synapses of cultured hippocampal neurons, weak stimulations also caused a decrease in ATP concentrations. Finally, quantitative modeling indicated that a pure ADP-based feedback mechanism can explain the activity-dependent ATP production when assuming a three-times higher maximal rate of ATP production compared to our measured rate of ATP production during high-frequency transmission. Our data reveal ATP reduction in presynaptic terminals during physiological-like activity, provide quantitative constraints on feedback mechanisms, and suggest that the ATP concentration can decrease during signaling, at least in some neuronal compartments of our brain