Search

Aneurysms of the internal carotid artery (ICA) are subdivided according to their location along the ICA into proximal or paraclinoid aneurysms, aneurysms of the middle segment, and terminal aneurysms. Aneurysms may be related to branches of the ICA—that is, the ophthalmic artery, the posterior communicating artery (Pcom), or the anterior choroidal artery (AChA)—but a considerable proportion are unrelated to side branches. Aneurysms of the ICA can reach giant size and present with optic nerve compression.

We consider graphs that admit polyline drawings where all crossings occur at the same angle α ∈ (0, π/2). We prove that every graph on n vertices that admits such a polyline drawing with at most two bends per edge has O(n) edges. This result remains true when each crossing occurs at an angle from a small set of angles. We also provide several extensions that might be of independent interest.

The Wenchuan earthquake produced surface ruptures with the most complicated structures and the greatest length as compared with the intra-plate reverse faulting earthquakes that have ever been reported so far (Xu et al., 2008a). The earthquake ruptured simultaneously both the NE-trending, NW-dipping Beichuan and Pengguan faults with right-slip component on the middle segment of the Longmenshan thrust belt, resulting in two sub-parallel imbricate surface rupture zones accompanied by a secondary NW-trending rupture zone linking the two major rupture zones at the southern end of the Pengguan fault through a lateral ramp

As ore-controlling structures, the Punda and Selanjan breccia pipes in Sarawak, Malaysia, are typical hypabyssal breccia pipes. Such breccias and their related mineralization types show distinct vertical zonation. The Punda ore-controlling breccia is a characteristic collapse breccia in the top segment of the hypabyssal breccia pipe, indicating that the erosional depth of the breccia pipe is shallow. The Punda breccia pipe controls the occurrence of a typical high sulphidation epithermal deposit and has good mineralization potential at depth. In the Selanjan breccia pipe, the ore-controlling breccia is a typical explosive breccia developed at the bottom of the breccia pipe, and a fluidization breccia in the middle segment of the breccia pipe. The explosive breccia and fluidization breccia control porphyry gold mineralization and low sulphidation epithermal mineralization respecti vely. The erosion of the breccia pipe is deep and is unfavourable for the preservation of gold mineralization.

Based on anatomic investigations of the structure (Bousquet 1977; Fabbriciani et al. 1982a,b; Furst 1903; Last 1948; Tabutin 1977) and function of the popliteus system (Basmajian and Lovejoy 1971; Bousquet 1977; Jakob et al. 1981; Staubli and Birrer 1989; Staubli and Jakob 1988; Staubli et al. 1981), the arthroscopically visible structures of the popliteal hiatus (Patel 1981) were functionally analyzed. The normal functional anatomy was compared with arthroscopically detectable lesions of the popliteus system in acute ruptures of the anterior cruciate ligament (ACL) and chronic ACL-deficient knees (Staubli and Birrer 1989,1990).

In this section we describe the reduction of the remaining eighteen of the 36 cases in (8.0.3), (8.0.4) and (8.0.7). There are again four types of reduced game, corresponding to (A), (B), (C) and (D) in (8.0.4). In our description of these, the first nonzero main-diagonal element is again always -1, and off-diagonal zeros are concentrated in a middle segment of the first subdiagonal. The remainder of th€ matrix is the same in all cases, and may be described by the diagram in Figure 9.

The paper deals with the geological and metallogenic characteristics of a group of tin deposits which are controlled essentially by metamorphism of the Lantang Group of Late Triassic-Early Jurassic sandstone and shale along the Lianhuashan fracture zone. The characteristics of spatial distribution and mineral association of the tin deposits suggest that their formation is closely related to fracturing and metamorphism in the fracture zone. The syngenetic sandstone ellipsoids in some ore deposits are rich in metallic elements, such as Sn, Pb, Zn and Cu, while the oolites are rich in Sn. This indicates that both the ore-forming and the rock-forming elements must have been deposited from the sea water. The oxygen and sulphur isotopes tend to show that the major ore-forming elements and fluids were not of a mantle source.