Zeolites and amorphous silica-alumina (ASA), which both provide Brønsted acid sites (BASs), are the most extensively used solid acid catalysts in the chemical industry. It is widely believed that BASs consist only of tetra-coordinated aluminum sites (AlIV) with bridging OH groups in zeolites or nearby silanols on ASA surfaces. Here we report the direct observation in ASA of a new type of BAS ba...

Autonomous Land Vehicles (ALVs), due to their considerable potential applications in areas such as mining and defence, are currently the focus of intense research at robotics institutes worldwide. Control systems that provide reliable navigation, often in complex or previously unknown environments, is a core requirement of any ALV implementation. Three key aspects for the provision of such auto...

Facedwith the prevalence ofmulti-spatial resolution satellite data sets, selecting data with an appropriate resolution has become a new problem. This paper analyses the significance of scale selection of remote sensing images and discusses a geo-statistics based method for selecting the optimal spatial resolution of a remote sensing image. Breaking through the limitation of traditional average ...

In this article, a new collision-avoidance scheme is proposed for autonomous land vehicle (ALV) navigation in indoor corridors. The goal is to conduct indoor collisionfree navigation of a three-wheel ALV among static obstacles with no a priori position information as well as moving obstacles with unknown trajectories. Based on the predicted positions of obstacles, a local collision-free path is...

According to current models of retrovirus infection, receptor binding to the surface subunit (SU) of the envelope glycoprotein (Env) triggers a conformational change in the transmembrane subunit (TM) that mediates virus fusion to cell membranes. To understand how this occurs, we investigated the role of the receptor Tva in avian leukosis virus-A (ALV-A) infection. We find that Tva binding induc...

To study the effect of intron size on splicing efficiency we have varied the size of the avian leukosis virus (ALV) env mRNA intron in a cloned ALV genome. This was accomplished by deletion of ALV sequences or insertion of phage lambda DNA. The effect of these modifications on splicing was analyzed by microinjection of the modified clones into RSV(-) chicken cells. Viral env mRNA when transcrib...

ion-Link-View [Hill92] (kurz ALV, ausgesprochen "Elwie") wurde als Grundlage des Groupware-Systems Rendezvous benutzt [HBP+93]. Die Motivation für ALV war, jedem Benutzer eine individuelle Sicht auf gemeinsame Daten anzubieten. Eine Sicht kann zur Laufzeit eingerichtet und geändert werden. So können beispielsweise statistische Daten für einen Benutzer als Kuchendiagramm, für einen anderen als H...

BACKGROUND End-tidal P(CO(2)) (Pe'(CO(2))) is routinely used in the clinical assessment of the adequacy of ventilation because it provides an estimate of Pa(CO(2)). How well Pe'(CO(2)) reflects Pa(CO(2)) depends on the gradient between them, expressed as ΔPa-e'(CO(2)). The major determinant of ΔPa-e'(CO(2)) is alveolar dead space (Vd(alv)). The fraction of inspired O(2) (Fi(O(2))) is not though...

Leukocytoclastic vasculitis (LV) is characterized by neutrophilic invasion and fibrinoid necrosis along with endothelial enlargement in postcapillary venules. Annular appearance of LV (ALV) is rare, but it can be accompanied by several systemic diseases. One of these systemic diseases is ulcerative colitis (UC), a subgroup of inflammatory bowel disease. Only one case was previously reported in ...