The welfare effects of inflation: a cost-benefit perspective

This paper reviews theory and evidence of the welfare effects of inflation from a costbenefit perspective. Basic models and selected empirical results are discussed. Historically, in assessing the welfare effects of inflation, the distortion of money demand played a prominent role. More recently, interactions of inflation and taxation came into focus. Growth effects of inflation as well as welfare effects of unanticipated inflation and of inflation uncertainty are also addressed. To assess the policy question whether inflation should be reduced or eliminated, the costs of disinflation play a role. Finally, the trade-off between the benefits of reducing inflation and the costs of disinflation is discussed and an overall assessment of the net welfare effects of achieving price stability is provided. --Inflation,price stability,welfare costs and benefits,distortions,money demand,consumption allocation,tax-inflation interaction

The Role of Beliefs for the Sustainability of the Fiscal Constitution

Why does the government not defect from the constitution? This article focuses on the dynamic restraints the government faces under the rule of law: violations against unconstitutional laws are not punished under the constitution. If a violating government cannot commit itself never to reinstall the constitution enforcing an unconstitutional law becomes difficult. Citizens? expectations to go unpunished when not complying may be self-fulfilling. Deriving the equilibrium of a global game we show that this mechanism is effectively deterring a government from defecting from a constitutionally permissible tax rate. --tax evasion,global games,selffulfilling expectations,dynamic policy restraints

Human Pheromones: Integrating Neuroendocrinology and Ethology

The effect of sensory input on hormones is essential to any explanation of mammalian behavior, including aspects of physical attraction. The chemical signals we send have direct and developmental effects on hormone levels in other people. Since we don't know either if, or how, visual cues might have direct and developmental effects on hormone levels in other people, the biological basis for the development of visually perceived human physical attraction is currently somewhat questionable. In contrast, the biological basis for the development of physical attraction based on chemical signals is well detailed

Wahrnehmung von Wirtsdüften durch Forstschädlinge : Vergleich zwischen einem Holzbrüter und einem Rindenbrüter

The blue pine wood borer (Phaenops cyanea) and the black pine sawyer beetle (Monochamus galloprovincialis) (Fig. 1) both are pests of the white pine (Pinus silvestris) and other Pinus species. Both insects have nearly the same demands regarding their breeding site. Larval development requires a fresh, unwilted inner bark. An infestation occurs on freshly cut trees or on trees suffering from stress (e.g. after dry seasons, loss of needles caused by feeding caterpillars or damage by forest fires). Phaenops cyanea detects susceptible pines by their volatile emissions (SCHÜTZ et al. 2004) and is able to infest the trees already at a low stress level. During feeding the larvae avoid the resin ducts of the tree and thus evade the oleoresin defence. The beetle is endemic in Europe and – under favourable climatic conditions – can cause substantial damage to pine forests. It is the most significant bark-breeding beetle of white pine in the lowlands of north-eastern Germany. Monochamus galloprovincialis is found in Europe and northern Africa. The larvae tend to a more copious feeding which makes them more susceptible to the oleoresin defence of the tree. Thus, M. galloprovincialis prefers trees that are weakened by a higher degree of stress. The economic damage caused by feeding of thebeetle is low. However, the beetle has gained a special attention of forest scientists because of its association with the nematode Bursaphelenchus xylophilus which is causing the pine wilt disease (PWD) in Pinus. The only outbreak of the PWD within Europe is limited to an area of 258.000 ha in Portugal. (MOTA et al. 1999).Die Forstschädlinge Phaenops cyanea (Coleoptera: Buprestidae) und Monochamus galloprovincialis (Coleoptera: Cerambycidae) befallen beide Kiefern (Pinus sylvestris), die geschwächt sind, z.B. durch Wasser-Stress. Die Larven von P. cyanea entwickeln sich in oder unter der Rinde, während Larven von M. galloprovincialis nach einem Fraß im Kambium des befallenen Baumes auch tief in das Holz eindringen. P. cyanea befällt bereits Bäume, die nur einem geringen Stress ausgesetzt waren, während M. galloprovincialis Bäume bevorzugt, die erheblich geschwächt oder bereits tot sind. Die vorliegende Studie soll anhand elektrophysiologischer Experimente untersuchen, welchen olfaktorischen Hinweisen die beiden Insekten bei ihrer Suche nach einem geeigneten Eiablageplatz folgen. Duftstoffe von Pinus sylvestris wurden auf Aktivkohle gesammelt und mit Gaschromatographie, Massenspektroskopie und Elektroantennographie untersucht (GC-MS/ EAD). Die stärksten Signale von P. cyanea traten im Retentionsindex-Bereich von 936 (α-Pinen) bis 1200 auf, wobei insbesondere bizyklische Terpene und Terpenoide wie α-Pinen, β-Pinen, 1,8-Cineol und trans- Verbenol detektiert wurden. M. galloprovincialis reagierte auf einen weiteren Bereich von Stoffen, ebenfalls beginnend mit α-Pinen, bis hin zu Stoffen mit einem Retentionsindex von ca. 1300. Es scheint eine spezifische Empfindlichkeit für monozyklische und azyklische Terpene und Terpenoide vorzuliegen, insbesondere für γ-Terpinen, Terpinolen, β-Myrcen und p-Cymen

Proteomic Investigation of the HIV Receptors CD4 and DC-Sign/CD209

HIV infection and disease is a multistage process that involves a variety of cell types as the virus spreads through the body. Initially, dendritic cells (DCs) present at the mucosal site of infection bind and internalise HIV for degradation and presentation to T cells. As the DCs migrate to lymph nodes and mature, part of the internalised virions remains infective inside endosomal compartments. During formation of the immunological synapse between CD4 T cells and DCs, infective virions from dendritic cells are transferred to CD4 T cells leading to a strong infection of those cells allowing rapid virus dissemination throughout the body and establishment of the typical HIV infection. Various membrane receptors are involved in this process. Initial HIV binding to DCs is mediated by C-type lectin receptors such as the mannose receptor or DC-SIGN (DC specific intracellular adhesion molecule 3 grabbing non integrin) which is followed by virus internalisation and lysis albeit virus induced changes in endocytic routing prevents a proportion from degradation. Productive infection of DCs has also been observed allowing trans infection of CD4 T cells through a different mechanism. HIV infection of CD4 T cells, DCs and other cells is a multistep process initiated by binding of HIV envelope gp120 to the CD4 receptor, a 55 kDa transmembrane glycoprotein. Subsequent conformational changes in gp120 allow binding to a chemokine receptor, either CCR5 or CXCR4, followed by membrane fusion and infection. The aim of this thesis was to investigate protein associations with the HIV receptors DC-SIGN and CD4 in order to elucidate the mechanism of complex formation, virus entry and/or defining target sites for antiretroviral drugs. This thesis used a proteomic approach for studying the receptors with mass spectrometry-based protein identification as its core technology. A range of different approaches were developed and compared for identification of protein interactions and characterisation of the identified protein associations. An affinity purification of the CD4 receptor complex from lymphoid cells was used as the basis for detecting novel CD4-binding proteins. For this approach a strategy based on mass spectrometry identification of CD4 associating proteins using affinity chromatography and affinity-tag mediated purification of tryptic peptides was developed. This method proved successful for the identification of CD4 interacting proteins such as the strongly associated kinase p56lck, however a limited number of non-specifically bound proteins were also identified along the receptor complex. Using one-dimensional SDS-polyacrylamide gel electrophoresis followed by in-gel digests and mass spectrometry analysis, a large number of non-specifically binding proteins were identified along the CD4/lck complex. Evaluation of different lysis buffers in several independent experiments demonstrated that there was a large and inconsistent array of proteins that were obviously non-specifically bound to the receptor. No further specific binding partners were detected. These data suggested that protein interactions of CD4 on this cell type are of weak and/or transient nature. It also demonstrated a need for careful interpretation of proteomic data in the light of the propensity of non-specific binding under these conditions. To overcome dissociation of weak protein interactions, a method was developed using chemical cross-linking to preserve weak protein interactions on lymphoid cells. Affinity purification was used to purify CD4 along with cross-linked associated proteins and mass spectrometry analysis identified an interaction with the transferrin receptor CD71 and the tyrosine phosphatase CD45. The CD45-CD4 interaction is well known. The CD4-CD71 interaction was demonstrated to be a result from colocalization of the two molecules during formation of endocytic vesicles. Flow cytometry-based fluorescence resonance energy transfer (FRET) measurements were applied to confirm colocalization. A similar interaction was suspected for CD4 and DC-SIGN on the plasma membrane of DCs as cis infection of DCs has been demonstrated i.e. initial binding to DC-SIGN then to CD4/CCR5 on the same cell. Therefore, protein associations of DC-SIGN were investigated using the developed techniques. Using cross-linking, DC-SIGN was shown to assemble in large complexes on the surface of immature monocyte-derived DCs. Mass spectrometry analysis of the purified complexes identified them as homo-oligomers of DC-SIGN. The absence of CD4 suggested that the fraction interacting with CD4 at any one time must be small. The complexes of DC-SIGN were further characterised to be tetramers and successfully co-immunoprecipitated with HIV gp120 and mannan. DC-SIGN monomers were not evident demonstrating that the assembly of DC-SIGN into tetramers is required for high affinity binding of its natural and viral ligands. Thus potential antiviral agents aimed at blocking the early stage of HIV binding to DCs must simulate tetramers in order to neutralise the virus efficiently. Overall the thesis provides new information on protein interactions of CD4 and DC-SIGN, a careful investigation of "proteomics" techniques for identifying the proteins in affinity-purified samples and demonstrates the need for multifaceted analytical approaches to probe complex cellular systems

Homosexual Orientation in Males: Evolutionary and Ethological Aspects

Evolutionary theory proposes that adaptive traits are reproduced more successfully than maladaptive traits. Accordingly, natural selection should favour heterosexuality as it facilitates reproduction and the propagation of genes. However, the question becomes, what has maintained homosexuality in a small but consistent percentage of the human population? Research into the evolutionary and hormonal factors associated with a homosexual orientation have yielded provocative but inconsistent results. It also suggests that human sexual orientation, and in particular homosexual orientation, is too complex to be described by one simple model or a single research discipline. The current paper treads a new path and emphasises an integrative approach for the understanding of homosexuality. The authors examine the combined effects of evolutionary factors and neurohormonal processes on the development of a homosexual orientation. It is suggested that research into the topic could benefit from an examination of and change in some of the assumptions upon which much past research has been based

Controlled low-temperature molecular manipulation of sexiphenyl molecules on Ag(111) using scanning tunneling microscopy

A novel scanning tunneling microscope manipulation scheme for a controlled molecular transport of weakly adsorbed molecules is demonstrated. Single sexiphenyl molecules adsorbed on a Ag(111) surface at 6 K are shot towards single silver-atoms by excitation with the tip. To achieve atomically straight shooting paths, an electron resonator consisting of linear standing wave fronts is constructed. The sexiphenyl manipulation signals reveal a pi-ring flipping as the molecule moves from hcp to fcc site. Abinitio calculations show an incorporation of the Ag atom below the center of a pi-ring.Comment: 4 pages, 4 figures, accepted for publication in Phys. Rev. Let

Vom Ende der Natur als normativer Begründungsressource in spätmodernen Gesellschaften

"Allgemein wird in der Soziologie heute die selbstkritische Diagnose eines 'ökologischen Defizits' gestellt. Häufig verbunden ist damit die Forderung, Natur als Kategorie in die Soziologie (wieder)einzuführen. Wenn man jedoch akzeptiert, daß Soziologie die Wissenschaft von den gesellschaftlichen Ordnungsvorstellungen und des sinnhaft orientierten Handelns ist, fällt es schwer, einen direkten Bezug zu den stofflich-materiellen Aspekten herzustellen, die Grundlage einer ökologischen Selbstgefährdung sein mögen. Naheliegender und im soziologischen Forschungsprogramm anschlußfähiger erscheint es zunächst, die Bedeutung der jeweiligen Naturvorstellungen für die Begründung gesellschaftlicher Ordnungskonzepte zu untersuchen. In meinem Beitrag vertrete ich die These, daß sich der Geltungsanspruch jeglicher Rekurse auf Natur in spätmodernen Gesellschaften hier als kaum noch begründbar erweist. Denn solange man Natur als gegeben und von gesellschaftlicher Manipulation unbeeinflußt konzipieren konnte, eignete sich der Rekurs auf Natur zur stabilen Grenzziehung für den Geltungsbereich gesellschaftlicher Verantwortung: Gesellschaftliche Entscheidungen sind zu begründen, naturbedingte Ereignisse sind als Schicksal hinzunehmen. Doch mit den wachsenden wissenschaftlich-technischen Manipulationsmöglichkeiten und unter dem Eindruck ökologischer Krisenerscheinungen wird diese Grenzziehung problematisch. An die Stelle der Grenze zwischen Gesellschaft und Natur tritt nun die Grenze zwischen Wissen und Nicht-Wissen. Hier rückt die Wissenschaft in eine Schlüsselstellung für die Integration der ganzen Gesellschaft ein. Aber die Wissenschaft ist selbst, zumindest in ihrem Objektivitätsanspruch und damit in ihrem Anspruch, allgemeingültige Definitionen des Wissensstands liefern zu können, auf die Unterscheidung zwischen Gesellschaft und Natur angewiesen, deren Realitätsgehalt und Gültigkeit gerade im Schwinden begriffen ist. Daraus ergeben sich problematische Konsequenzen, die weder in einer linearen Fortschreibung der Modernisierungstheorie noch im Sinne reflexiver Modernisierung einfach zu lösen sind." (Autorenreferat