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[1] In the Shiquanhe area of far-western Tibet, midCretaceous strata lie unconformable on ophiolitic melange and Jurassic flysch associated with the Bangong-Nujiang suture zone. On the basis of our mapping and geochronologic studies, we suggest that these Cretaceous strata were shortened by >57% over a north south distance of 50 km during Late Cretaceousearly Tertiary time. The Late Cretaceous Narangjiapo thrust placed Permian strata >20 km over ophiolitic melange and Cretaceous strata. North of the Narangjiapo thrust, >40 km of shortening was accommodated by the Late Cretaceous-early Tertiary south directed Jaggang thrust system that involves Jurassic flysch and Cretaceous strata, and roots into a decollement within ophiolitic melange. The most recent shortening was accommodated to the south of the Narangjiapo thrust, along the north dipping Shiquanhe thrust. The Shiquanhe thrust cuts flat-lying 22.6 ± 0.3 Ma volcanic rocks and underlying folded, Tertiary nonmarine strata in its footwall and was likely active during slip along the Oligocene Gangdese thrust system of southern Tibet. Ophiolitic melange and structurally overlying Jurassic flysch near Shiquanhe are interpreted to represent remnants of a subduction-accretion complex and forearc basin, respectively, that were obducted southward onto the margin of the Lhasa terrane during Late Jurassic-Early Cretaceous closure of the Bangong-Nujiang Ocean. Subsequent imbrication of the obducted sheet could have produced the two eastwest trending belts of ophiolitic melanges, separated by $100 km, in western Tibet. Late Cretaceous-early Tertiary thin-skinned shortening may have been accommodated in the deeper crust by northward underthrusting and duplexing of Lhasa terrane rocks beneath the obducted ophiolitic melange and the Qiangtang terrane to the north.

Geologic mapping and geochronological analysis in southwest (Kailas area) and southeast (Zedong area) Tibet reveal two major episodes of Tertiary crustal shortening along the classic Indus-Tsangpo suture in the Yalu River valley. The older event occurred between ca. 30 and 24 Ma during movement along the north-dipping Gangdese thrust. The development of this thrust caused extensive denudation of the Gangdese batholith in its hanging wall and underthrusting of the Xigaze forearc strata in its footwall. Examination of timing of major tectonic events in central Asia suggests that the initiation of the Gangdese thrust was approximately coeval with the late Oligocene initiation and development of north-south shortening in the eastern Kunlun Shan of northern Tibet, the Nan Shan at the northeastern end of the Altyn Tagh fault, the western Kunlun Shan at the southwestern end of the Altyn Tagh fault, and finally the Tian Shan (north of the Tarim basin). Such regionally synchronous initiation of crustal shortening in and around the plateau may have been related to changes in convergence rate and direction between the Eurasian plate and the Indian and Pacific plates. The younger thrusting event along the Yalu River valley occurred between 19 and 10 Ma along the south-dipping Great Counter thrust system, equivalent to the locally named Renbu-Zedong thrust in southeastern Tibet, the Backthrust system in south-central Tibet, and the South Kailas thrust in southwest Tibet. The coeval development of the Great Counter thrust and the North Himalayan granite-gneiss dome belt is consistent with their development being related to thermal weakening of the north Himalayan and south Tibetan crust, due perhaps to thermal relaxation of an already thickened crust created by the early phase of collision between India and Asia or frictional heating along major thrusts, such as the Main Central thrust, beneath the Himalaya.

Most patients with non-lesional temporal lobe epilepsy (NLTLE) will have the findings of hippocampal sclerosis (HS) on a high resolution MRI. However, a significant minority of patients with NLTLE and electroclinically well-lateralized temporal lobe seizures have no evidence of HS on MRI. Many of these patients have concordant hypometabolism on fluorodeoxyglucose-PET ([18F]FDG-PET). The pathophysiological basis of this latter group remains uncertain. We aimed to determine whether NLTLE without HS on MRI represents a variant of or a different clinicopathological syndrome from that of NLTLE with HS on MRI. The clinical, EEG, [18F]FDG-PET, histopathological and surgical outcomes of 30 consecutive NLTLE patients with well-lateralized EEG but without HS on MRI (HS-ve TLE) were compared with 30 consecutive age- and sex-matched NLTLE patients with well-lateralized EEG with HS on MRI (HS+ve TLE). Both the HS+ve TLE group and the HS-ve TLE patients had a high degree of [18F]FDG-PET concordant lateralization (26 out of 30 HS-ve TLE versus 27 out of 27 HS+ve TLE). HS-ve TLE patients had more widespread hypometabolism on [18F]FDG-PET by blinded visual analysis [odds ratio (OR = + infinity (2.51, -), P = 0.001]. The HS-ve TLE group less frequently had a history of febrile convulsions [OR = 0.077 (0.002-0.512), P = 0.002], more commonly had a delta rhythm at ictal onset [OR = 3.67 (0.97-20.47), P = 0.057], and less frequently had histopathological evidence of HS [OR = 0 (0-0.85), P = 0.031]. There was no significant difference in surgical outcome despite half of those without HS having a hippocampal-sparing procedure. Based on the findings outlined, HS-ve PET-positive TLE may be a surgically remediable syndrome distinct from HS+ve TLE, with a pathophysiological basis that primarily involves lateral temporal neocortical rather than mesial temporal structures.

Figure 1. Simplified geologic map of southwest Tibet compiled from mapping by Augusto Gansser (Heim and Gansser, 1939), Tibetan Bureau of Geology and Mineral Resources (Cheng and Xu, 1987), Yin et al. (1999b), and our own observations.M ABSTRACT Field mapping and geochronologic and thermobarometric analyses of the Gurla Mandhata area, in southwest Tibet, reveal major middle to late Miocene, east-west extension along a normal-fault system, termed the Gurla Mandhata detachment system. The maximum fault slip occurs along a pair of low-angle normal faults that have caused significant tectonic denudation of the Tethyan Sedimentary Sequence, resulting in juxtaposition of weakly metamorphosed Paleozoic rocks and Tertiary sedimentary rocks in the hanging wall over amphibolite-facies mylonitic schist, marble, gneisses, and variably deformed leucogranite bodies in the footwall. The footwall of the detachment fault system records a late Miocene intrusive event, in part contemporaneous with top-to-the-west ductile normal shearing. The consistency of the mean shear direction within the mylonitic footwall rocks and its correlation with structurally higher brittle normal faults suggest that they represent an evolving low-angle normal-fault system. 40 Ar/ 39 Ar data from muscovite and biotite from the footwall rocks indicate that it cooled below 400 ؇C by ca. 9 Ma. Consideration of the original depth and dip angle of the detachment fault prior to exhumation of the footwall yields total slip estimates between 66 and 35 km across the Gurla Mandhata detachment system. The slip estimates and timing constraints on the Gurla Mandhata detachment system are comparable to those estimated on the right-slip Karakoram fault system, to which it is interpreted to be kinematically linked. Moreover, the mean shear-sense direction on both the Karakoram fault and the Gurla Mandhata detachment system overlap along the intersection line between the mean orientations of the faults, which further supports a kinematic association. If valid, this interpretation extends previous results that the Karakoram fault extends to mid-crustal depths.

IgG is the predominant immunoglobulin in cervicovaginal mucus (CVM), yet how IgG in mucus can protect against infections is not fully understood. IgG diffuses rapidly through cervical mucus, slowed only slightly by transient adhesive interactions with mucins. We hypothesize this almost unhindered diffusion allows IgG to accumulate rapidly on pathogen surfaces, and the resulting IgG array forms multiple weak adhesive crosslinks to mucus gel that effectively trap (immobilize) pathogens, preventing them from initiating infections. Here, we report herpes simplex virus serotype 1 (HSV-1) readily penetrated fresh, pH-neutralized ex vivo samples of CVM with low or no detectable levels of anti-HSV-1 IgG, but was trapped in samples with even modest levels of anti-HSV-1 IgG. In samples with little or no endogenous anti-HSV-1 IgG, addition of exogenous anti-HSV-1 IgG, affinity purified from intravenous immunoglobulin, trapped virions at concentrations below those needed for neutralization and with similar potency as endogenous IgG. Deglycosylating purified anti-HSV-1 IgG, or removing its Fc component, markedly reduced trapping potency. Finally, a non-neutralizing IgG against HSV-gG significantly protected mice against vaginal infection, and removing vaginal mucus by gentle lavage abolished protection. These observations suggest IgG-Fc has a glycan dependent “muco-trapping” effector function that may provide exceptionally potent protection at mucosal surfaces.

Field mapping, structural analysis, and geochronologic data from northwestern Nepal reveal major normal right‐slip motion along a previously unrecognized west‐northwest striking system of shear zones that we term the Gurla Mandhata–Humla fault system (GMH). The GMH obliquely cuts across the Greater Himalayan Crystalline sequence and into the Lesser Himalayan imbricate thrust belt via two right‐step‐over structures. The average slip direction on the GMH parallels the strike of the Himalayan orogen. Motion along this fault system has resulted in an apparent left separation of the South Tibet Detachment, Main Central thrust zone, and Lesser Himalayan imbricate thrust belt along a north striking segment of the fault system. We estimate a minimum of 21 km of net slip on the southern branch of the GMH by restoring the trace of the Main Central thrust zone parallel to the average slip direction on the fault. Taking into account slip estimates from the northern branch of the GMH yields a minimum net slip estimate of 24.4 to 32.4 km for the GMH. The 232Th/208Pb ion microprobe monazite ages from leucogranite bodies indicate that motion on the GMH occurred after 15 Ma. Its initiation immediately followed crustal thickening between the Main Central thrust zone and Indus‐Yalu suture zone. Motion on the GMH is contemporaneous with arc‐normal contraction in the southernmost Himalayan orogen. These observations can be explained by a model that involves foreland propagating structural systems facilitating arc‐normal contraction in the foreland and arc‐parallel extension in the hinterland that work together to maintain the arcuate shape of the Himalayan orogen.

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