Improving magnetic resonance spectroscopy in the brainstem periaqueductal gray using spectral registration

Purpose: Functional understanding of the periaqueductal gray (PAG), a clinically relevant brainstem region, can be advanced using ¹H‐MRS. However, the PAG's small size and high levels of physiological noise are methodologically challenging. This study aimed to (1) improve ¹H‐MRS quality in the PAG using spectral registration for frequency and phase error correction; (2) investigate whether spectral registration is particularly useful in cases of greater head motion; and (3) examine metabolite quantification using literature‐based or individual‐based water relaxation times. Methods: Spectra were acquired in 33 healthy volunteers (50.1 years, SD = 17.19, 18 females) on a 3 T Philipps MR system using a point‐resolved spectroscopy (PRESS) sequence optimized with very selective saturation pulses (OVERPRESS) and voxel‐based flip angle calibration (effective volume of interest size: 8.8 × 10.2 × 12.2 mm³). Spectra were fitted using LCModel and SNR, NAA peak linewidths and Cramér‐Rao lower bounds (CRLBs) were measured after spectral registration and after minimal frequency alignment. Results: Spectral registration improved SNR by 5% (p = 0.026, median value post‐correction: 18.0) and spectral linewidth by 23% (p < 0.001, 4.3 Hz), and reduced the metabolites' CRLBs by 1% to 15% (p < 0.026). Correlational analyses revealed smaller SNR improvements with greater head motion (p = 0.010) recorded using a markerless motion tracking system. Higher metabolite concentrations were detected using individual‐based compared to literature‐based water relaxation times (p < 0.001). Conclusion: This study demonstrates high‐quality ¹H‐MRS acquisition in the PAG using spectral registration. This shows promise for future ¹H‐MRS studies in the PAG and possibly other clinically relevant brain regions with similar methodological challenges

Fostering Empathic Skills in Mainstream Public School Pupils: Efficacy Assessment of the EPaN Empathy Training Program

Empathic skills are called for in every social interaction, but there are few evidence-based programs in the mainstream public school sector exclusively dedicated to fostering the empathic sub-components of recognition of emotions, emotional perspective taking and affective responsiveness in pupils. The EPaN program is based on the latest scientific knowledge and best practices that can be taught in the classroom.In the course of eight school weeks, using a pre-post-test design we studied the effectiveness of an empathy training program (EPaN) in nine classes with a total of 123 mainstream public school pupils aged 11.2 to 15.2 years, divided into intervention groups that were assigned a total of 24 exercises of 15 to 40 minutes duration and control groups that followed the regular lesson plan.After the training, variance analysis showed a significant improvement in the empathic sub-capacities for recognition of emotion, emotional perspective taking and affective responsiveness in the intervention groups compared to the control groups. These results are examined in light of their importance and adaptability of the EPaN program to educational practice

In situ temperature determination using magnetic resonance spectroscopy thermometry for noninvasive postmortem examinations

Magnetic resonance spectroscopy (MRS) thermometry offers a noninvasive, localized method for estimating temperature by leveraging the temperature‐dependent chemical shift of water relative to a temperature‐stable reference metabolite under suitable calibration. Consequentially, this technique has significant potential as a tool for postmortem MR examinations in forensic medicine and pathology. In these examinations, the deceased are examined at a wide range of body temperatures, and MRS thermometry may be used for the temperature adjustment of magnetic resonance imaging (MRI) protocols or for corrections in the analysis of MRI or MRS data. However, it is not yet clear to what extent postmortem changes may influence temperature estimation with MRS thermometry. In addition, N‐acetylaspartate, which is commonly used as an in vivo reference metabolite, is known to decrease with increasing postmortem interval (PMI). This study shows that lactate, which is not only present in significant amounts postmortem but also has a temperature‐stable chemical shift, can serve as a suitable reference metabolite for postmortem MRS thermometry. Using lactate, temperature estimation in postmortem brain tissue of severed sheep heads was accurate up to 60 h after death, with a mean absolute error of less than 0.5°C. For this purpose, published calibrations intended for in vivo measurements were used. Although postmortem decomposition resulted in severe metabolic changes, no consistent deviations were observed between measurements with an MR‐compatible temperature probe and MRS thermometry with lactate as a reference metabolite. In addition, MRS thermometry was applied to 84 deceased who underwent a MR examination as part of the legal examination. MRS thermometry provided plausible results of brain temperature in comparison with rectal temperature. Even for deceased with a PMI well above 60 h, MRS thermometry still provided reliable readings. The results show a good suitability of MRS thermometry for postmortem examinations in forensic medicine

Ballistic study on the penetration potential and injury potential of different bullet types in the use of a newly developed bullet shooting stunner for adequate stunning of heavy cattle

IntroductionRecently, a special bullet shooting stunner for heavy cattle has been developed that fires a bullet instead of a bolt. In the search for a suitable ammunition, the following criteria must be met: First, the energy of the bullet must be sufficient to penetrate the thick frontal bones of heavy cattle. Second, the injury potential at the corresponding penetration depth should preferably be large in order to damage brain tissue relevant to stunning. Third, the bullet must not perforate the occipital bone (over-penetration).MethodsFour different bullet types [Hornady FTX, Hydra-Shok, Black Mamba, and a common full metal jacket (FMJ) bullet] were evaluated in a series of experiments on soap blocks and removed bone plates followed by computed tomography examinations. Penetration potential was evaluated in terms of kinetic energy relative to the caliber of the bullet, i.e., mean energy density (ED). Injury potential was evaluated by the mean extent of the cavity volume (e$_{CV}$) at the relevant penetration depth of 5.5 to 7.5 cm in the soap block.ResultsAll four bullet types passed through the frontal bone plate. The ED was 17.50 J/mm$^{2}$ (Hornady FTX), 17.46 J/mm$^{2}$ (Hydra-Shok), 13.47 J/mm$^{2}$ (Black Mamba), and 13.47 J/mm$^{2}$ (FMJ). The Hornady FTX and the Hydra-Shok each fragmented heavily. The FMJ was excluded after three experiments due to over-penetrations. The e$_{CV}$ was e$_{CV}$ = 3.77 cm$^{2}$ (Hornady FTX), 2.71 cm$^{2}$ (Hydra-Shok), and 1.31 cm$^{2}$ (Black Mamba), with a significant difference (p = 0.006) between the Hornady FTX and the Black Mamba.DiscussionFor use in heavy cattle, the Hornady FTX and the Hydra-Shok are recommended due to the larger e$_{CV}$ than the Black Mamba

Effects of Psychotherapy on Glutamatergic Neurotransmission

Introduction: Psychodynamic psychotherapy is an effective and widely used treatment for major depressive disorder (MDD); however, little is known about neurobiological changes associated with induced symptom improvement. Methods: Proton magnetic resonance spectroscopy with a two-dimensional J-resolved sequence served to test the relationship between glutamate (Glu) and glutamine (Gln) levels, measured separately in pregenual anterior cingulate cortex (pgACC) and the anterior midcingulate cortex (aMCC) as a control region, with change in depression symptoms after 6 months of weekly psychodynamic psychotherapy sessions in MDD patients. Depressed (N = 45) and healthy (N = 30) subjects participated in a baseline proton magnetic resonance spectroscopy measurement and a subgroup of MDD subjects (N = 21) then received once-a-week psychodynamic psychotherapy and participated in a second proton magnetic resonance spectroscopy measurement after 6 months. Change in depression symptoms was assessed using the Hamilton Depression Rating Scale (HAMD). Results: Higher pretreatment pgACC Gln concentrations in MDD patients compared to healthy controls were associated with symptom severity. Patients and controls did not differ regarding Gln levels in aMCC nor regarding Glu levels in both regions. The association of pgACC Gln concentration and severity of depressive symptoms was reversed after 6 months of psychotherapy in MDD subjects. Regarding Gln in aMCC as well as Glu in both regions, there were no significant associations with improvement of depressive symptoms in the course of psychotherapy. Discussion: Findings indicate specific regional effects of psychodynamic psychotherapy on glutamatergic neurotransmission and thereby highlight the key role of the pgACC in both depression pathophysiology and recovery

Effects of psychotherapy on glutamatergic neurotransmission

Introduction: Psychodynamic psychotherapy is an effective and widely used treatment for major depressive disorder (MDD); however, little is known about neurobiological changes associated with induced symptom improvement. Methods: Proton magnetic resonance spectroscopy with a two-dimensional J-resolved sequence served to test the relationship between glutamate (Glu) and glutamine (Gln) levels, measured separately in pregenual anterior cingulate cortex (pgACC) and the anterior midcingulate cortex (aMCC) as a control region, with change in depression symptoms after 6 months of weekly psychodynamic psychotherapy sessions in MDD patients. Depressed (N = 45) and healthy (N = 30) subjects participated in a baseline proton magnetic resonance spectroscopy measurement and a subgroup of MDD subjects (N = 21) then received once-a-week psychodynamic psychotherapy and participated in a second proton magnetic resonance spectroscopy measurement after 6 months. Change in depression symptoms was assessed using the Hamilton Depression Rating Scale (HAMD). Results: Higher pretreatment pgACC Gln concentrations in MDD patients compared to healthy controls were associated with symptom severity. Patients and controls did not differ regarding Gln levels in aMCC nor regarding Glu levels in both regions. The association of pgACC Gln concentration and severity of depressive symptoms was reversed after 6 months of psychotherapy in MDD subjects. Regarding Gln in aMCC as well as Glu in both regions, there were no significant associations with improvement of depressive symptoms in the course of psychotherapy. Discussion: Findings indicate specific regional effects of psychodynamic psychotherapy on glutamatergic neurotransmission and thereby highlight the key role of the pgACC in both depression pathophysiology and recovery

Automotive Powertrain Control — A Survey

This paper surveys recent and historical publications on automotive powertrain control. Control-oriented models of gasoline and diesel engines and their aftertreatment systems are reviewed, and challenging control problems for conventional engines, hybrid vehicles and fuel cell powertrains are discussed. Fundamentals are revisited and advancements are highlighted. A comprehensive list of references is provided.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72023/1/j.1934-6093.2006.tb00275.x.pd

On measuring developing central executive processes in pre- and primary school children with the random generation task

Das Ziel der vorliegenden Arbeit besteht in der Untersuchung sich entwickelnder zentral-exekutiver Arbeitsgedächtnisprozesse bei Vor- und Grundschulkindern. Dazu wurden fünf Experimente mittels der Random Generation Aufgabe durchgeführt: Hierbei müssen Versuchspersonen Zufallsreihen auf der Grundlage eines vorgegebenen Itempools, z.B. Zahlen oder Tasten eines Keyboards, bilden. In Experiment 1 wurde der Einfluss unterschiedlicher Ausgabemodalitäten (sprachgestützt und motorisch) und der expliziten Begrenzung des Ereignisraumes (geschlossen vs. offen) auf die Randomisierungsleistung von 5-jährigen, 9-jährigen und Erwachsenen untersucht. Neben einem generellen Alterseffekt zeigten sich für die 5-jährigen sowohl in der motorischen als auch verbalen Modalität Schwierigkeiten mit den weniger bekannten Ereignisräumen. Demgegenüber ergab sich innerhalb der 9-jährigen und Erwachsenen ein genereller, wenngleich geringfügiger Leistungsvorteil zugunsten der sprachlichen Modalität. Experiment 2 diente zur Untersuchung der Stabilität von Random Generation Maßen. 6-, 8- und 10-Jährige sowie Erwachsene wurden dreimal im einwöchigen Abstand mittels einer verbalen, räumlichen und motorischen Random Generation Aufgabe untersucht. Es ergaben sich ebeso wie in Experiment 1 Alters- als auch Modalitätsunterschiede, ferner zeigte sich eine zunehmende Stabilität bei der Generierung von Zufallsreihen mit ansteigendem Alter. In Experiment 3 wurden die kurzzeitigen Speicheranforderungen während der Random Generation Aufgabe über die Itempoolgröße sowie eine externe Unterstützung der Ereignisraumrepräsentation variiert. Dabei zeigte sich, dass bei dynamischer Unterstützung die Leistung der 6-jährigen verbessert und die Leistung der 8- und 10-jährigen an das Niveau der Erwachsenen angeglichen werden kann. Damit definieren sich altersbedingte Leistungsunterschiede bei der Random Generation Aufgabe maßgeblich über Speicher und Repräsentationsprozesse. Die Rolle von Inhibitionsprozessen wurde in Experiment 4 untersucht. Hier mussten 6-, 8-, 10-jährige und Erwachsene aus einem zahlenbasierten Itempool gezielt Items auslassen. Die derart variierte Inhibitionsanforderung zeigte jedoch nur einen geringfügigen Einfluss auf die Randomisierungsleistung. Ebenso wie in Experiment 3 konnte ein Effekt des Alters und der dynamischen Unterstützung gefunden werden. In Experiment 5 wurde ein Vergleich von Random Generation mit 6 anderen, etablierten zentral-exekutiven Maßen vorgenommen. Dazu wurden 5-, 6-, 8- und 10-jährige sowie Erwachsene untersucht. Neben deutlichen Altersunterschieden in allen zentral-exekutiven Maßen, ergaben sich Zusammenhangsmuster, die den multi-prozessualen Anforderungscharakter der Random Generation Aufgabe bestätigen. Die Befunde aus den 5 Experimenten zeigen, dass sich zentral-exekutive Entwicklung ab dem 5. Lebensjahr gut abbilden lässt. Darüberhinaus konnte nachgewiesen werden, dass sich Altersdifferenzen bei der Random Generationaufgabe über unterschiedlich geartete Speicher-, Abruf-, Monitoring- und Inhibitionsprozesse konstituieren.The goal of present study is the examination of developing central-executive working memory processes in pre- and primary school children. For this reason 5 experiments were carried out by using the Random Generation task. Within the Random Generation task subjects are required to generate a random series of items, i.e. by using a given amount numbers or keys of a keyboard. Experiment 1 was done to disentangle the influence of different output modalities (verbal and motor) on randomization performance. Furthermore the aspect of the explicit limitation of the item pool (limited vs. open) was also varied. 5-year-olds, 9-year-olds and adults took part in the first experiment. Next to a general age effect the 5-year-olds were found to have difficulties in unfamiliar motor and verbal item pools. Also for the 9-year-olds and adults no linear effect for the factor explicit limitations could be found, albeit the output modality proved to be slightly relevant as verbally based Random Generation was in general more random. In Experiment 2 the stability of Random Generation was investigated. 6-year-olds, 8-year-olds, 10-year-olds and adults were tested three times with an inter test interval of one week. The subjects had to do verbal, spatial and motor Random Generation tasks. As in experiment 1 an effect of age and modality could be found. Moreover stability of randomization performance was found to increase in the older subjects. Experiment 3 was carried out to examine the short-term memory processes within the Random Generation task. This was done by varying the amount of items to be randomized on the one hand and by the presentation of external item pool and monitoring cues on the other hand. Findings indicate that an external support of item representation improves performance of the 6-year-olds and made 8-year-old und 10-year-old subjects perform nearly on an adult level. Therefore it seems that age differences are considerably defined by storage and representation processes. The role of inhibition processes was analyzed in experiment 4: 6-year-olds, 8-year-olds, 10-year-olds and adults had to randomize numbers orally. Additionally they were told to inhibit some specially designated numbers of the original item pool series. The factor of inhibition showed only a small effect on randomization performance, but as in the previous experiment a clear effect of age and external support could be found. In experiment 5 a correlational analysis on Random Generation and 6 different, well established central executive operationalizations was done. 5-year-olds, 6-year-olds, 8-year-olds, 10-year-olds and adults took part in the experiment. A clear age effect was proved for all seven central-executive operationalizations. Further more correlational analysis revealed the multi process demands of the random generation task. The findings from the five experiments indicate that central executive development can be tested and demonstrated from the fifth year of age on. Additionally it could be shown that age differences in the Random Generation task are due to different storage and retrieval processes on the one hand and monitoring and inhibition processes on the other hand