Structure of a Complete ATP Synthase Dimer Reveals the Molecular Basis of Inner Mitochondrial Membrane Morphology

We determined the structure of a complete, dimeric F1Fo-ATP synthase from yeast Yarrowia lipolytica mitochondria by a combination of cryo-EM and X-ray crystallography. The final structure resolves 58 of the 60 dimer subunits. Horizontal helices of subunit a in Fo wrap around the c-ring rotor, and a total of six vertical helices assigned to subunits a, b, f, i, and 8 span the membrane. Subunit 8 (A6L in human) is an evolutionary derivative of the bacterial b subunit. On the lumenal membrane surface, subunit f establishes direct contact between the two monomers. Comparison with a cryo-EM map of the F1Fo monomer identifies subunits e and g at the lateral dimer interface. They do not form dimer contacts but enable dimer formation by inducing a strong membrane curvature of ∼100°. Our structure explains the structural basis of cristae formation in mitochondria, a landmark signature of eukaryotic cell morphology

Coupling biological detection to liquid chromatography

La forma habitual de probar la actividad biológica de una planta dada es a partir de una extracto crudo y, si resultase de interés, continuar con la tediosa y costosa y laboriosas tareas de fraccionamiento, purificación y análisis sistemático de cada fracción resultante. Este procedimiento es actualmente el mismo para mezclas complejas resultantes de métodos sintéticos modernos como la química combinatoria. El procedimiento para la caracterización del fármaco se verá beneficiada si se puede restringir el estudio a solo aquellas fracciones donde la actividad biológica estaba presente.CONACYT – Consejo Nacional de Ciencia y TecnologíaPROCIENCI

Moral enhancement: do means matter morally?

One of the reasons why moral enhancement may be controversial, is because the advantages of moral enhancement may fall upon society rather than on those who are enhanced. If directed at individuals with certain counter-moral traits it may have direct societal benefits by lowering immoral behavior and increasing public safety, but it is not directly clear if this also benefits the individual in question. In this paper, we will discuss what we consider to be moral enhancement, how different means may be used to achieve it and whether the means we employ to reach moral enhancement matter morally. Are certain means to achieve moral enhancement wrong in themselves? Are certain means to achieve moral enhancement better than others, and if so, why? More specifically, we will investigate whether the difference between direct and indirect moral enhancement matters morally. Is it the case that indirect means are morally preferable to direct means of moral enhancement and can we indeed pinpoint relevant intrinsic, moral differences between both? We argue that the distinction between direct and indirect means is indeed morally relevant, but only insofar as it tracks an underlying distinction between active and passive interventions. Although passive interventions can be ethical provided specific safeguards are put in place, these interventions exhibit a greater potential to compromise autonomy and disrupt identity

Negotiating topic changes:native and non-native English speakers in conversation

There is a tendency to view conversations involving non‐native speakers (NNSs) as inevitably fraught with problems, including an inability to handle topic management. This article, in contrast, will focus on effective topic changes made by non‐native speakers during informal conversations with native speakers of English. A micro‐analysis of ten conversations revealed several ways of shifting conversational topics; however, the article concentrates on those strategies which the participants used to effect a particular type of topic move, namely ‘marked topic changes’, where there is no connection at all with previous talk. The findings show how these topic changes were jointly negotiated, and that the non‐native speakers’ contributions to initiating new topics were competently managed

Mapping NGC 7027 in New Light: CO+^+ and HCO+^+ Emission Reveal Its Photon- and X-ray-Dominated Regions

The young and well-studied planetary nebula NGC 7027 harbors significant molecular gas that is irradiated by luminous, point-like UV (central star) and diffuse (shocked nebular) X-ray emission. This nebula represents an excellent subject to investigate the molecular chemistry and physical conditions within photon- and X-ray-dominated regions (PDRs and XDRs). As yet, the exact formation routes of CO$^+$ and HCO$^+$ in PN environments remain uncertain. Here, we present $\sim$2$"$ resolution maps of NGC 7027 in the irradiation tracers CO$^+$ and HCO$^+$, obtained with the IRAM NOEMA interferometer, along with SMA CO and HST 2.12~$\mu$m H$_2$ data for context. The CO$^+$ map constitutes the first interferometric map of this molecular ion in any PN. Comparison of CO$^+$ and HCO$^+$ maps reveal strikingly different emission morphologies, as well as a systematic spatial displacement between the two molecules; the regions of brightest HCO$^+$, found along the central waist of the nebula, are radially offset by $\sim$1$"$ ($\sim$900 au) outside the corresponding CO$^+$ emission peaks. The CO$^+$ emission furthermore precisely traces the inner boundaries of the nebula's PDR (as delineated by near-IR H$_2$ emission), suggesting that central star UV emission drives CO$^+$ formation. The displacement of HCO$^+$ radially outward with respect to CO$^+$ is indicative that dust-penetrating soft X-rays are responsible for enhancing the HCO$^+$ abundance in the surrounding molecular envelope, forming an XDR. These interferometric CO$^+$ and HCO$^+$ observations of NGC 7027 thus clearly establish the spatial distinction between the PDR and XDR formed (respectively) by intense UV and X-ray irradiation of molecular gas.Comment: 15 pages, 7 figures, 1 tabl

EXAFS investigation of the interaction of hafnium and thorium with humic acid and Bio-Rex 70

The interaction of hafnium(IV) and thorium(iv) with humic acid, HA, is studied using EXAFS and compared to the interaction of these metal ions with carboxylate groups of the cation exchanger Bio-Rex70. Fourier-f'fltered Hf and Th I-,3 edge transmission EXAFS for the first oxygen shell is analyzed. For both Hf(IV)- HA and Hf(IV)-Bio-Rex70, in wet paste and air-dried forms, 6-7 oxygen atoms at R=2.14 A are found. Th(IV)-HA also exhibits coordination similar to Th(IV)-Bio-Rex70. These observations support conclusions from previous studies on U(VI)-HA that metal cations are sorbed primarily onto HA carboxylate groups; other HA functional groups play a less significant role

Pulping characteristics of Willamette Valley grass straws

Published November 1974. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalo