Introducing many-body physics using atomic spectroscopy

Atoms constitute relatively simple many-body systems, making them suitable objects for developing an understanding of basic aspects of many-body physics. Photoabsorption spectroscopy is a prominent method to study the electronic structure of atoms and the inherent many-body interactions. In this article the impact of many-body effects on well-known spectroscopic features such as Rydberg series, Fano resonances, Cooper minima, and giant resonances is studied, and related many-body phenomena in other fields are outlined. To calculate photoabsorption cross sections the time-dependent configuration interaction singles (TDCIS) model is employed. The conceptual clearness of TDCIS in combination with the compactness of atomic systems allows for a pedagogical introduction to many-body phenomena.Comment: 15 pages, 6 figures, 1 table. The following article has been accepted by American Journal of Physic

Pentamethylcyclopentadienyl[bis(trimethylsilyl)methylen]phosphan - ein Phosphaalken mit einer reaktiven PC-Einfachbindung

Synthesis, spectroscopic data and X-ray structure determination of a novel phosphaalkene, Me5C5-P=C(SiMe3)2 1, are reported. It is shown by dynamic 1H-NMR spectroscopy that 1 exhibits thermal E/Z-isomerization of the double bond at ambient temperature. Reactions of 1 involve electrophilic attack of the π-system with hard (H+) and soft (Ag+) Lewis-acids, and an unusual cleavage of a PC-single bond on reaction with metal complexes (MeCN)3M(CO)3, (M = Mo, W)

Metallophospha-alkenes: a simple access and some reactivities involving the phosphorus atom

The synthesis and studies on the reactive behaviour of metallophospha-alkenes are reported

Männer, Väter, Jungen - kontrovers

Bislang kein Thema für standpunkt : sozial: Maenner, Vaeter, Soehne. Die wenigen Ausnahmen lassen sich an den Fingern einer Hand abzaehlen und bestaetigen nur die Regel. Und das, obwohl das herkoemmliche Bild vom "starken Geschlecht" schon laenger ins Gerede gekommen und stattdessen das Schlagwort von der "Krise des Mannes" allseits zu vernehmen ist. Lothar Boehnisch bringt die veränderte Situation auf den Punkt, wenn er feststellt: "Maennlichkeit ist vom Status- zum Bewältigungsproblem geworden". Grund genug für standpunkt : sozial, das Maenner-Thema in seiner Bedeutung fuer die Sozialarbeit aufzunehmen und nach neuen Konzepten fuer die Arbeit mit Maennern, Vaetern und Jungen zu schauen. Einen ersten Einblick in die aktuelle Situation will dieser Themen - Schwerpunkt bieten

Thyroid function tests in patients taking thyroid medication in Germany: Results from the population-based Study of Health in Pomerania (SHIP)

<p>Abstract</p> <p>Background</p> <p>Studies from iodine-sufficient areas have shown that a high proportion of patients taking medication for thyroid diseases have thyroid stimulating hormone (TSH) levels outside the reference range. Next to patient compliance, inadequate dosing adjustment resulting in under- and over-treatment of thyroid disease is a major cause of poor therapy outcomes. Using thyroid function tests, we aim to measure the proportions of subjects, who are under- or over-treated with thyroid medication in a previously iodine-deficient area.</p> <p>Findings</p> <p>Data from 266 subjects participating in the population-based Study of Health in Pomerania (SHIP) were analysed. All subjects were taking thyroid medication. Serum TSH levels were measured using immunochemiluminescent procedures. TSH levels of < 0.27 or > 2.15 mIU/L in subjects younger than 50 years and < 0.19 or > 2.09 mIU/L in subjects 50 years and older, were defined as decreased or elevated, according to the established reference range for the specific study area. Our analysis revealed that 56 of 190 (29.5%) subjects treated with thyroxine had TSH levels outside the reference range (10.0% elevated, 19.5% decreased). Of the 31 subjects taking antithyroid drugs, 12 (38.7%) had TSH levels outside the reference range (9.7% elevated, 29.0% decreased). These proportions were lower in the 45 subjects receiving iodine supplementation (2.2% elevated, 8.9% decreased). Among the 3,974 SHIP participants not taking thyroid medication, TSH levels outside the reference range (2.8% elevated, 5.9% decreased) were less frequent.</p> <p>Conclusion</p> <p>In concordance with previous studies in iodine-sufficient areas, our results indicate that a considerable number of patients taking thyroid medication are either under- or over-treated. Improved monitoring of these patients' TSH levels, compared to the local reference range, is recommended.</p

Expression patterns of protein C inhibitor in mouse development

Proteolysis of extracellular matrix is an important requirement for embryonic development and is instrumental in processes such as morphogenesis, angiogenesis, and cell migration. Efficient remodeling requires controlled spatio-temporal expression of both the proteases and their inhibitors. Protein C inhibitor (PCI) effectively blocks a range of serine proteases, and recently has been suggested to play a role in cell differentiation and angiogenesis. In this study, we mapped the expression pattern of PCI throughout mouse development using in situ hybridization and immunohistochemistry. We detected a wide-spread, yet distinct expression pattern with prominent PCI levels in skin including vibrissae, and in fore- and hindgut. Further sites of PCI expression were choroid plexus of brain ventricles, heart, skeletal muscles, urogenital tract, and cartilages. A strong and stage-dependent PCI expression was observed in the developing lung. In the pseudoglandular stage, PCI expression was present in distal branching tubules whereas proximal tubules did not express PCI. Later in development, in the saccular stage, PCI expression was restricted to distal bronchioli whereas sacculi did not express PCI. PCI expression declined in postnatal stages and was not detected in adult lungs. In general, embryonic PCI expression indicates multifunctional roles of PCI during mouse development. The expression pattern of PCI during lung development suggests its possible involvement in lung morphogenesis and angiogenesis

Agouti-related peptide neural circuits mediate adaptive behaviors in the starved state

In the face of starvation, animals will engage in high-risk behaviors that would normally be considered maladaptive. Starving rodents, for example, will forage in areas that are more susceptible to predators and will also modulate aggressive behavior within a territory of limited or depleted nutrients. The neural basis of these adaptive behaviors likely involves circuits that link innate feeding, aggression and fear. Hypothalamic agouti-related peptide (AgRP)-expressing neurons are critically important for driving feeding and project axons to brain regions implicated in aggression and fear. Using circuit-mapping techniques in mice, we define a disynaptic network originating from a subset of AgRP neurons that project to the medial nucleus of the amygdala and then to the principal bed nucleus of the stria terminalis, which suppresses territorial aggression and reduces contextual fear. We propose that AgRP neurons serve as a master switch capable of coordinating behavioral decisions relative to internal state and environmental cues