Status and Power Do Not Modulate Automatic Imitation of Intransitive Hand Movements

The tendency to mimic the behaviour of others is affected by a variety of social factors, and it has been argued that such “mirroring” is often unconsciously deployed as a means of increasing affiliation during interpersonal interactions. However, the relationship between automatic motor imitation and status/power is currently unclear. This paper reports five experiments that investigated whether social status (Experiments 1, 2, and 3) or power (Experiments 4 and 5) had a moderating effect on automatic imitation (AI) in finger-movement tasks, using a series of different manipulations. Experiments 1 and 2 manipulated the social status of the observed person using an associative learning task. Experiment 3 manipulated social status via perceived competence at a simple computer game. Experiment 4 manipulated participants’ power (relative to the actors) in a card-choosing task. Finally, Experiment 5 primed participants using a writing task, to induce the sense of being powerful or powerless. No significant interactions were found between congruency and social status/power in any of the studies. Additionally, Bayesian hypothesis testing indicated that the null hypothesis should be favoured over the experimental hypothesis in all five studies. These findings are discussed in terms of their implications for AI tasks, social effects on mimicry, and the hypothesis of mimicry as a strategic mechanism to promote affiliation.     

T1 Relaxation Time in Lungs of Asymptomatic Smokers

Purpose

Interest in using T₁ as a potential MRI biomarker of chronic obstructive pulmonary disease (COPD) has recently increased. Since tobacco smoking is the major risk factor for development of COPD, the aim for this study was to examine whether tobacco smoking, pack-years (PY), influenced T₁ of the lung parenchyma in asymptomatic current smokers.

Materials and Methods

Lung T₁ measurements from 35 subjects, 23 never smokers and 12 current smokers were retrospectively analyzed from an institutional review board approved study. All 35 subjects underwent pulmonary function test (PFT) measurements and lung T_1, with similar T₁ measurement protocols. A backward linear model of T₁ as a function of FEV₁, FVC, weight, height, age and PY was tested.

Results

A significant correlation between lung T₁ and PY was found with a negative slope of -3.2 ms/year (95% confidence interval [CI] [-5.8, -0.6], p = 0.02), when adjusted for age and height. Lung T₁ shortens with ageing among all subjects, -4.0 ms/year (95%CI [-6.3, -1.7], p = 0.001), and among the never smokers, -3.7 ms/year (95%CI [-6.0, -1.3], p = 0.003).

Conclusions

A correlation between lung T₁ and PY when adjusted for both age and height was found, and T₁ of the lung shortens with ageing. Accordingly, PY and age can be significant confounding factors when T₁ is used as a biomarker in lung MRI studies that must be taken into account to detect underlying patterns of disease.     

Infants' Peripheral Blood Lymphocyte Composition Reflects Both Maternal and Post-Natal Infection with Plasmodium falciparum

Maternal parasitoses modulate fetal immune development, manifesting as altered cellular immunological activity in cord blood that may be linked to enhanced susceptibility to infections in early life. Plasmodium falciparum typifies such infections, with distinct placental infection-related changes in cord blood exemplified by expanded populations of parasite antigen-specific regulatory T cells. Here we addressed whether such early-onset cellular immunological alterations persist through infancy. Specifically, in order to assess the potential impacts of P. falciparum infections either during pregnancy or during infancy, we quantified lymphocyte subsets in cord blood and in infants'' peripheral blood during the first year of life. The principal age-related changes observed, independent of infection status, concerned decreases in the frequencies of CD4⁺, NK^dim and NKT cells, whilst CD8⁺, Treg and Teff cells'' frequencies increased from birth to 12 months of age. P. falciparum infections present at delivery, but not those earlier in gestation, were associated with increased frequencies of Treg and CD8⁺ T cells but fewer CD4⁺ and NKT cells during infancy, thus accentuating the observed age-related patterns. Overall, P. falciparum infections arising during infancy were associated with a reversal of the trends associated with maternal infection i.e. with more CD4⁺ cells, with fewer Treg and CD8⁺ cells. We conclude that maternal P. falciparum infection at delivery has significant and, in some cases, year-long effects on the composition of infants'' peripheral blood lymphocyte populations. Those effects are superimposed on separate and independent age- as well as infant infection-related alterations that, respectively, either match or run counter to them.     

Is Using the Strengths and Difficulties Questionnaire in a Community Sample the Optimal Way to Assess Mental Health Functioning?

An important characteristic of a screening tool is its discriminant ability or the measure’s accuracy to distinguish between those with and without mental health problems. The current study examined the inter-rater agreement and screening concordance of the parent and teacher versions of SDQ at scale, subscale and item-levels, with the view of identifying the items that have the most informant discrepancies; and determining whether the concordance between parent and teacher reports on some items has the potential to influence decision making. Cross-sectional data from parent and teacher reports of the mental health functioning of a community sample of 299 students with and without disabilities from 75 different primary schools in Perth, Western Australia were analysed. The study found that: a) Intraclass correlations between parent and teacher ratings of children’s mental health using the SDQ at person level was fair on individual child level; b) The SDQ only demonstrated clinical utility when there was agreement between teacher and parent reports using the possible or 90% dichotomisation system; and c) Three individual items had positive likelihood ratio scores indicating clinical utility. Of note was the finding that the negative likelihood ratio or likelihood of disregarding the absence of a condition when both parents and teachers rate the item as absent was not significant. Taken together, these findings suggest that the SDQ is not optimised for use in community samples and that further psychometric evaluation of the SDQ in this context is clearly warranted.     

Mit dem integrierten pflanzenschutz ins neue jahrtausend*

Mit dem integrierten Pflanzenschutz steht zu Beginn des neuen Jahrtausends eine Strategie zur Verfügung, die einer modernen, wettbewerbsfähigen Landwirtschaft eine nachhaltige und ökologisch fundierte Entwicklung sichert. Die Absicht, die biologische Bekämpfung in landwirtschaftlichen Kulturpflanzenbeständen als Alternative zum chemischen Pflanzenschutz zu etablieren, hat sich als Fehlorientierung erwiesen. Gezielten, d.h. auf Basis wissenschaftlich fundierter Schad‐ oder Bekämpfungsschwellen beruhenden chemischen Maßnahmen gegen Schädlinge, Krankheitserreger und Unkräuter kommt auch zukünftig eine überragende Bedeutung zu. Im Vorfeld des chemischen Pflanzenschutzes verdienen acker‐ und pflanzenbauliche Kulturmaßnahmen und die Resistenzzüchtung besondere Beachtung. Letztere dürfte durch die Nutzung der modernen Gentechnik und Biotechnologie völlig neuartige Impulse erhalten, zu überraschenden Lösungen bei der Schaderregerbekämpfung führen und somit auch den Umfang des chemischen Pflanzenschutzes reduzieren helfen.

Die unverzichtbare Integration ökologischer Belange in den landwirtschaftlichen Pflanzenschutz muss mit Sachkunde, Realitätsnähe und auf der Grundlage wissenschaftlich fundierter Ergebnisse und Aussagen erfolgen. Wichtig ist vor allem die exakte Kenntnis der aktuellen ökologischen Situation, um Fehlinterpretationen zu vermeiden und Wunschdenken und spekulativen Aussagen den Nährboden zu entziehen.

In der ökologischen Forschung stehen seit Jahrzehnten die epigäischen Raubarthro‐poden, namentlich Webspinnen (Araneae), Laufkäfer (Carabidae) und Kurzflügelkäfer (Staphylinidae), im Mittelpunkt des Interesses, da sie wertvolle Bioindikatoren für Diversität, Stabilität und Belastbarkeit auch von Agrarökosystemen darstellen.

Vergleichende ökologische Studien auf großen Winterweizenflächen in einer “ausgeräumten”;, strukturarmen Agrarlandschaft in Sachsen‐Anhalt (Raum Halle/Saale) und auf einem kleinen Winterweizenfeld in einer reich strukturierten Feldflur in Niedersachsen (Raum Braunschweig) belegen eindrucksvoll, dass bei Beachtung der Normen des integrierten Pflanzenschutzes auf großen Schlägen keine ökologischen Defizite eintreten. Bei Webspinnen und Laufkäfern konnte in den großen Beständen sogar eine signifikant höhere Artendichte gegenüber der kleinen Fläche registriert werden.

Ergebnisse über den Einfiuss chemischer Maßnahmen auf die epigäische Fauna liegen von zwei großen Kulturflächen in Obhausen und Peißen (beide Sachsen‐Anhalt) für eine fünfjährige Fruchtfolge vor. Von den sechs Großparzellen (72 m x 200 m) auf jedem Feld dienten zwei als Kontrolle (ohne chemischen Pflanzenschutz), auf zwei Teilstücken gelangten chemische Pflanzenschutzmittel nach dem Schadschwellenkonzept zur Anwendung (integrierter Pflanzenschutz) und auf zwei weiteren Parzellen wurde ein intensiver Einsatz chemischer Mittel praktiziert. Insgesamt konnten etwa 350 000 Arthropoden gefangen und zumeist auch determiniert werden. Die Arten‐ und Individuendichten der Webspinnen, Laufkäfer und Kurzflügler erreichten während der Untersuchungszeit durchgängig hohe Werte, wobei zwischen den Varianten “Kontrolle”; und “integrierter Pflanzenschutz”; kaum Unterschiede auszumachen waren. Selbst im Versuchsglied “intensiver Pflanzenschutz”; erwiesen sich die gelegentlichen Defizite in den Arten‐ und Individuenspektren keineswegs als gravierend, sondern stets als kurzzeitige Effekte. Zum Versuchsende ergaben sich für alle Parzellen nahezu identische Werte für die Entomofauna.

Beachtung verdient auch die Tatsache, dass auf den Parzellen ein Drittel aller für Sachsen‐Anhalt bekannten Webspinnen gefunden wurde (158 Spezies). Gleichermaßen bedeutsam ist der Nachweis von zahlreichen “Rote‐Liste‐Arten”; an Webspinnen und Laufkäfern sowie der Wiederfund einer Webspinne, die in Deutschland als ausgestorben gilt (Nurscia albomaculata Lucas). “Ökologische Reparaturleistungen”; in Gestalt einer Anlage von Saumbiotopen, Hecken, Ackerrandstreifen usw. sind demnach nicht vonnöten. Der Landwirtschaft und dem chemischen Pflanzenschutz einen Verlust oder zumindest einen Rückgang der biologischen Diversität anzulasten, entbehrt angesichts der vorgelegten Fakten und Zahlen jeglicher Grundlage. Auch ein Vergleich der ökologischen Gegebenheiten in den Agrargebieten Mitteldeutschlands in den 50er und 90er Jahren lieferte für spekulative Annahmen keine Anhaltspunkte und Argumente. Es muss vielmehr angenommen werden, dass über das gesamte vergangene Jahrhundert hinweg die Agrarökosysteme mit ihrem Arteninventar, trotz aller Wandlungen in der Landwirtschaft und im Pflanzenschutz, stabil geblieben sind.     

Dissection of the Neonatal Fc Receptor (FcRn)-Albumin Interface Using Mutagenesis and Anti-FcRn Albumin-blocking Antibodies

Albumin is the most abundant protein in blood and plays a pivotal role as a multitransporter of a wide range of molecules such as fatty acids, metabolites, hormones, and toxins. In addition, it binds a variety of drugs. Its role as distributor is supported by its extraordinary serum half-life of 3 weeks. This is related to its size and binding to the cellular receptor FcRn, which rescues albumin from intracellular degradation. Furthermore, the long half-life has fostered a great and increasing interest in utilization of albumin as a carrier of protein therapeutics and chemical drugs. However, to fully understand how FcRn acts as a regulator of albumin homeostasis and to take advantage of the FcRn-albumin interaction in drug design, the interaction interface needs to be dissected. Here, we used a panel of monoclonal antibodies directed towards human FcRn in combination with site-directed mutagenesis and structural modeling to unmask the binding sites for albumin blocking antibodies and albumin on the receptor, which revealed that the interaction is not only strictly pH-dependent, but predominantly hydrophobic in nature. Specifically, we provide mechanistic evidence for a crucial role of a cluster of conserved tryptophan residues that expose a pH-sensitive loop of FcRn, and identify structural differences in proximity to these hot spot residues that explain divergent cross-species binding properties of FcRn. Our findings expand our knowledge of how FcRn is controlling albumin homeostasis at a molecular level, which will guide design and engineering of novel albumin variants with altered transport properties.     

Grass lignin acylation: <Emphasis Type="Italic">p</Emphasis>-coumaroyl transferase activity and cell wall characteristics of C3 and C4 grasses

Grasses are a predominant source of nutritional energy for livestock systems around the world. Grasses with high lignin content have lower energy conversion efficiencies for production of bioenergy either in the form of ethanol or to milk and meat through ruminants. Grass lignins are uniquely acylated with p-coumarates (pCA), resulting from the incorporation of monolignol p-coumarate conjugates into the growing lignin polymer within the cell wall matrix. The required acyl-transferase is a soluble enzyme (p-coumaroyl transferase, pCAT) that utilizes p-coumaroyl-CoenzymeA (pCA-CoA) as the activated donor molecule and sinapyl alcohol as the preferred acceptor molecule. Grasses (C3and C4) were evaluated for cell wall characteristics; pCA, lignin, pCAT activity, and neutral sugar composition. All C3 and C4 grasses had measurable pCAT activity, however the pCAT activities did not follow the same pattern as the pCA incorporation into lignin as expected.     

Large-scale production of selected type A trichothecenes: the use of HT-2 toxin and T-2 triol as precursors for the synthesis of <Emphasis Type="Italic">d</Emphasis><Subscript>3</Subscript>-T-2 and <Emphasis Type="Italic">d</Emphasis><Subscript>3</Subscript>-HT-2 toxin

The type A trichothecenes T-2 and HT-2 toxins are toxic secondary metabolites produced by fungi of the Fusarium genus. Their occurrence in cereals, especially in oats, implies health risks for the consumer. Therefore, it is an important task to develop selective and sensitive methods for the analysis of T-2 and HT-2 toxins, and to undertake further studies on their stability and toxicity. Although most toxins are commercially available, their high prices are the limiting factor on the realization of these experiments. Thus, we developed a method for large-scale production of T-2 and HT-2 toxin as well as T-2 triol and T-2 tetraol. T-2 toxin was obtained in gram quantities by biosynthetic production with cultures of F. sporotrichioides. As HT-2 toxin was only formed as a by-product, and T-2 triol and T-2 tetraol were not generated, these compounds were produced by alkaline hydrolysis of T-2 toxin. Separation and isolation of crude toxins was achieved by fast centrifugal partition chromatography (FCPC), which is an efficient tool for the large-scale purification of natural products. Using this fast and yield effective technique, several hundred milligrams of HT-2 toxin, T-2 triol, and T-2 tetraol were obtained. Subsequent, HT-2 toxin and T-2 triol were used for the large-scale synthesis of isotope-labeled T-2 and HT-2 toxin, respectively. Using these standards, an isotope dilution-(ID)-HPLC-MS/MS method for the quantification of T-2 and HT-2 toxin in different matrices was developed.     

Changes of opening angle in hypertensive and hypotensive arteries in 3-day organ culture

To study the effect of pressure changes on the opening angle of arteries in organ culture, tubular segments of porcine common carotid arteries were cultured with pulsatile flow perfusion under hypertensive (150+/-20 mmHg), normotensive (100+/-20 mmHg), or hypotensive (30+/-10 mmHg) pressure while maintaining the arteris at a physiological wall shear stress of approximately 15 dyn/cm(2) for up to 3 days. Arteries were then cut into short ring segments by sections perpendicular to the axis and then cut open radially to observe the opening angle in aerated phosphate buffered saline solution (37 degrees C). Norepinephrine (NE, 10 microM), carbacol (CCh, 100 microM), and sodium nitroprusside (SNP, 10 microM) were added after the radial cut at 30, 20, and 30 min intervals, the opening angles were measured, respectively. Results show that hypertensive arteries developed a significantly larger opening angle than normotensive and hypotensive arteries, associated with a significant increase in cell proliferation. In addition, with smooth muscle contraction activated by NE, the opening angle decreases significantly in hypertensive arteries but has little change in hypotensive and normotensive arteries, indicating an enhancement of smooth muscle contraction on the lumen side of the hypertensive arterial wall. In comparison, hypotensive pressure has little effect on arterial opening angle and cell proliferation.