Time-referenced effects of an internal vs. external focus of attention on muscular activity and compensatory variability

The paralysis-by-analysis phenomenon, i.e., attending to the execution of one's movement impairs performance, has gathered a lot of attention over recent years (see Wulf, 2007, for a review). Explanations of this phenomenon, e.g., the hypotheses of constrained action (Wulf et al., 2001) or of step-by-step execution (Masters, 1992; Beilock et al., 2002), however, do not refer to the level of underlying mechanisms on the level of sensorimotor control. For this purpose, a “nodal-point hypothesis” is presented here with the core assumption that skilled motor behavior is internally based on sensorimotor chains of nodal points, that attending to intermediate nodal points leads to a muscular re-freezing of the motor system at exactly and exclusively these points in time, and that this re-freezing is accompanied by the disruption of compensatory processes, resulting in an overall decrease of motor performance. Two experiments, on lever sequencing and basketball free throws, respectively, are reported that successfully tested these time-referenced predictions, i.e., showing that muscular activity is selectively increased and compensatory variability selectively decreased at movement-related nodal points if these points are in the focus of attention.

Osteogenic potential of autogenous bone grafts harvested with four different surgical techniques

The osteogenic potential of autogenous bone grafts is superior to that of allografts and xenografts because of their ability to release osteoinductive growth factors and provide a natural osteoconductive surface for cell attachment and growth. In this in vitro study, autogenous bone particles were harvested by four commonly used techniques and compared for their ability to promote an osteogenic response. Primary osteoblasts were isolated and seeded on autogenous bone grafts prepared from the mandibles of miniature pigs with a bone mill, piezo-surgery, bone scraper, and bone drill (bone slurry). The osteoblast cultures were compared for their ability to promote cell attachment, proliferation, and differentiation. After 4 and 8 hrs, significantly higher cell numbers were associated with bone mill and bone scraper samples compared with those acquired by bone slurry and piezo-surgery. Similar patterns were consistently observed up to 5 days. Furthermore, osteoblasts seeded on bone mill and scraper samples expressed significantly elevated mRNA levels of collagen, osteocalcin, and osterix at 3 and 14 days and produced more mineralized tissue as assessed by alizarin red staining. These results suggest that the larger bone graft particles produced by bone mill and bone scraper techniques have a higher osteogenic potential than bone slurry and piezo-surgery.

Stereological Modelling of Random Particles

Stochastic models for three-dimensional particles have many applications in applied sciences. Lévy–based particle models are a flexible approach to particle modelling. The structure of the random particles is given by a kernel smoothing of a Lévy basis. The models are easy to simulate but statistical inference procedures have not yet received much attention in the literature. The kernel is not always identifiable and we suggest one approach to remedy this problem. We propose a method to draw inference about the kernel from data often used in local stereology and study the performance of our approach in a simulation study.

The effects of catecholamine depletion on the neural response to fearful faces in remitted depression

Recent evidence suggests that increased psychophysiological response to negatively valenced emotional stimuli found in major depressive disorder (MDD) may be associated with reduced catecholaminergic neurotransmission. Fourteen unmedicated, remitted subjects with MDD (RMDD) and 13 healthy control subjects underwent catecholamine depletion with oral α-methyl-para-tyrosine (AMPT) in a randomized, placebo-controlled, double-blind crossover trial. Subjects were exposed to fearful (FF) and neutral faces (NF) during a scan with [15O]H2O positron emission tomography to assess the brain-catecholamine interaction in brain regions previously associated with emotional face processing. Treatment with AMPT resulted in significantly increased, normalized cerebral blood flow (CBF) in the left inferior temporal gyrus (ITG) and significantly decreased CBF in the right cerebellum across conditions and groups. In RMDD, flow in the left posterior cingulate cortex (PCC) increased significantly in the FF compared to the NF condition after AMPT, but remained unchanged after placebo, whereas healthy controls showed a significant increase under placebo and a significant decrease under AMPT in this brain region. In the left dorsolateral prefrontal cortex (DLPFC), flow decreased significantly in the FF compared to the NF condition under AMPT, and increased significantly under placebo in RMDD, whereas healthy controls showed no significant differences. Differences between AMPT and placebo of within-session changes in worry-symptoms were positively correlated with the corresponding changes in CBF in the right subgenual prefrontal cortex in RMDD. In conclusion, this study provided evidence for a catecholamine-related modulation of the neural responses to FF expressions in the left PCC and the left DLPFC in subjects with RMDD that might constitute a persistent, trait-like abnormality in MDD.

Well-being and learning in school

Although there are various definitions for the term “well-being,” it is agreed that well-being in school represents a set of subjective feelings and attitudes toward school. Moreover, enjoyment (some use the term “happiness”) is recognized as a core element of well-being in general as well as at school. Well-being in school is defined as an indicator of the quality of scholastic life, and contributes to students’ physical and psychological health and development. As such it is strongly connected to learning. Well-being in school consists of cognitive, emotional, and physical components, i.e., a learner’s thoughts, feelings, and bodily sensations. Consequently, it differs significantly from an individual’s cognitive appraisals like satisfaction, or from discrete positive emotions like enjoyment. Well-being in school can be described through the relationship of positive and negative aspects of school life

Einheit der Diagnose und Vielheit der Therapien: Ergebnis haus- und kinderärztlicher Behandlung von Störungen der Aufmerksamkeit und Hyperaktivität bei Kindern und Jugendlichen 10 Jahre nach Integration verschiedener Behandlungsoptionen

Aufmerksamkeitsstörungen mit und ohne Hyperaktivität (AHDS/ ADS) gehören zu den häufigsten neuropsychiatrischen Diagnosen bei Kindern und Jugendlichen. Stimulantien haben einen hohen Stellenwert bei konventioneller multimodaler Behandlung und unerwünschte Auswirkungen, die nach anderen Therapieoptionen rufen. Es interessiert das Behandlungsergebnis einer einheitlich rekrutierten mit AD(H)S diagnostizierten Kohorte unter verschiedenen Therapieformen. Die Kinder, die nicht am Doppelblind-Versuch der Berner ADHSStudie (Frei H 2005) teilnahmen, werden in 3 diagnostische Gruppen klassifiziert: (A) AD(H)S-Diagnose und homöopathische Therapie (n = 12), (B) AD(H)S-Diagnose und vorwiegend andere Therapien (n = 13), (C) nicht eindeutige AD(H)S-Diagnose und verschiedene Therapieformen (n = 14). Der Behandlungsverlauf wird mit dem Conners’ Global Index (CGI) und offenen Fragen per Fragebogen oder Telefoninterview dokumentiert und überwiegend deskriptiv ausgewertet. Nach 10 Jahren gibt es CGI-Datensätze von 35/39 Personen (90%; 5 weiblich, 30 männlich). Die CGI-Differenz zwischen Diagnose (19.5, Bereich 14–28 Punkte) und Nachuntersuchung (8.7, 1–19) betrug für alle Patienten 10.8 Punkte (56%): in Gruppe A 61%, in den Gruppen B und C je 53%. Von den seit Rekrutierung einmal mit Methylphenidat (MPH, n = 22/39, 56%) behandelten Patienten waren 18 Patienten (82%), von den mit individueller Homöopathie Behandelten (n = 29/39, 75%) waren 17 Patienten (59%) im CGI mehr als 50% verbessert; je 7 Patienten bekamen beide Therapien. Bei 23/39 Patienten (60%) sind die MPHoder homöopathische Therapie abgeschlossen. Zwölf (12) Patienten sind noch in Behandlung: 9 mit MPH, 2 mit Homöopathie und 1 Patient mit beiden Therapien. Bei je drei Patienten waren homöopathische oder MPH-Medikamente nicht genügend erfolgreich, ein Patient erhielt ein Antidepressivum. In Übereinstimmung mit den CGI-Werten bezeichnen 25/35 Patienten (80%) ihr Befinden als besser. Sieben (7) Patienten (20%) bezeichnen ihr Befinden als gleich, obwohl die Differenz zum Ausgangswert mehr als 9 (10–14) Punkte (ca. 50% Besserung) beträgt. Der aktuelle CGI-Wert ist bei 4 dieser Patienten grösser als 14 Punkte und zeigt die Behandlungsbedürftigkeit an. Je 3 dieser 7 Patienten hatten oder haben noch MPH-Therapie mit einer Besserung von derzeit 40%. Die individuelle homöopathische Behandlung des AD(H)S scheint qualitativ der Stimulantientherapie ebenbürtig zu sein und kann deren Nebenwirkungen vermeiden.

Effects of stimulus with proinflammatory mediators on nitric oxide production and matrix metalloproteinase activity in explants of cranial cruciate ligaments obtained from dogs

OBJECTIVE To evaluate the origin and degree of activity of nitric oxide (NO) and matrix metalloproteinase (MMP) in explants of cranial cruciate ligaments (CCLs) obtained from dogs and cultured with and without inflammatory activators. SAMPLE POPULATION Tissue specimens obtained from 7 healthy adult Beagles that were (mean +/- SD) 4.5 +/- 0.5 years old and weighed 12.5 +/- 0.8 kg. PROCEDURE The CCLs were harvested immediately after dogs were euthanatized, and specimens were submitted for explant culture. Cultures were stimulated by incubation with a combination of interleukin-1, tumor necrosis factor-alpha, and lipopolysaccharide, or they were not stimulated. Culture supernatants were examined for production of NO nitrite-nitrate metabolites (NOts) and activity of MMP Cultured specimens were evaluated by use of immunohistochemical analysis to detect activity of inducible NO synthase (iNOS). RESULTS All ligament explants produced measurable amounts of NOts. Stimulated cultures produced significantly more NOts after incubation for 24 and 48 hours, compared with nonstimulated cultures. Production of MMP in supernatants after incubation for 48 hours was significantly higher in stimulated cultures than in nonstimulated cultures. Cells with positive staining for iNOS were detected on all slides. Positively stained cells were predominantly chondroid metaplastic. There was a significant difference in intensity of cell staining between stimulated and non-stimulated cultures. CONCLUSIONS AND CLINICAL RELEVANCE Explant cultures of intact CCLs obtained from dogs produce iNOS-induced NO. Stimulation of chondroid metaplastic cells in CCL of dogs by use of inflammatory activators can increase production of iNOS, NOts, and MMP.