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Aiming Lv,1,2 Tong Ding,2 DeQiong,2 DaWaZhuoMa,2 Long Cai,2 Yutong Zhang,2 Jinyu Yin,2 SeZhen,2 Qiubo Lv11Department of Obstetrics and Gynecology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, Beijing, People's Republic of China; 2Women and Children's Hospital of Tibet Autonomous Region, Lhasa, Tibet Autonomous Region, People's Republic of ChinaCorrespondence: Qiubo Lv, Department of Obstetrics and Gynecology, Beijing Hospital, National Center of Gerontology, Institute of Geriatric Medicine, Chinese Academy of Medical Sciences, No. 1 DaHua Road, Dong Dan, Beijing, 100730, People's Republic of China, Tel +86 13801192185, Fax +86 10 85136220, Email [email protected] Purpose: Pelvic floor disorder (PFD) seriously affects the everyday life of women. This cross-sectional study aimed to evaluate the prevalence and risk factors for postpartum PFD in women living in the Tibet Autonomous Region (TAR).Methods: Parous women who attended the outpatient gynaecology clinic at our hospital between June 2022 and August 2022 were screened in this study. The demographic and clinical data of these women were collected. Their pelvic floor functions were evaluated via a pelvic organ prolapse (POP) quantification examination, the Pelvic Floor Distress Inventory Questionnaire-20 (PFDI-20) and the Overactive Bladder Symptom Score (OABSS).Results: A total of 201 women were included in this study, of whom 81.09% (163/201) were Tibetan. Twenty-seven women (13.43%) were diagnosed with POP stage ≥ 2 and 27 women (13.43%) with an OABSS score ≥ 3. The median PFDI-20 total score was 4.17 (range 0– 43.75). Han women (n = 38) in the TAR had much lower PFDI-20 total scores, compared with Tibetan women (n = 163) (p < 0.05). The results of the multiple linear regression models showed that the PFDI-20 scores obtained from women living in the TAR were closely related to parity, history of heavy weight lifting, age, history of instrumental deliveries, ethnicity and number of caesarean sections.Conclusion: Pelvic floor disorder is common among parous women living in the TAR. Ethnicity, parity, history of heavy weight lifting, age, history of instrumental deliveries and number of caesarean sections are the factors closely related to the PFDI-20 scores. [ABSTRACT FROM AUTHOR]

Understanding the nature of parental melts for pyroxenite veins in supra‐subduction zone (SSZ) ophiolites provides vibrant constraints on melt infiltration processes operating in subduction zones. The Zedang ophiolitic massif in the eastern Yarlung–Zangbo suture zone in Tibet consists of mantle peridotites and a crustal section of gabbro, diabase, and basalt. Veins of two pyroxenite varieties cut the southern part of the Zedang massif. These pyroxenite rocks have different geochemical characteristics, where the first variety (type‐I) has relatively higher contents of SiO2 (51.82–53.08 wt%), MgO (20.08–23.23 wt%), and ΣPGE (3.42–13.97 ppb), and lower Al2O3 (1.59–2.28 wt%) and ΣREE (1.63–2.94 ppm). The second pyroxenite variety (type‐II) is characterized by SiO2 (45.44–49.61 wt%), MgO (16.68–19.78 wt%), Al2O3 (4.24–8.77 wt%), ΣPGE (14.46–322.06 ppb), and ΣREE (5.82–7.44 ppm). Pyroxenite type‐I shows N‐MORB‐like chondrite‐normalized REE patterns. Zircon U‐Pb ages of pyroxenite type‐I (194 ± 10 Ma), associated ophiolitic gabbro (135.3 ± 2.0 Ma), and plagiogranite (124.2 ± 2.3 Ma) evidently imply episodic evolution of the Zedang ophiolites. The mineralogical and geochemical characteristics of the investigated pyroxenites can be explained by subduction‐initiated hydrous melting of metasomatized sub‐arc mantle, later overprinted by sub‐slab mantle melting triggered by upwelling asthenosphere during the Jurassic–Early Cretaceous times. The geochemical variations in pyroxenite vein composition, coupled with age differences amongst the other ophiolite units, may correspond to intermittent emplacement of pyroxenite dikes and isotropic gabbroic intrusions where the geodynamic setting progressed from arc maturation and slab rollback to slab tearing and delamination. [ABSTRACT FROM AUTHOR]

The tectonic transition from oceanic subduction to continental collision is a fundamental process during orogenesis, yet the nature of such transition and associated deep geodynamic processes for the Tibetan Plateau are still controversial. The long‐lived magmatism of the Gangdese Belt of southern Tibet provides an excellent opportunity to study the tectonic transition from subduction of the Neo‐Tethys oceanic lithosphere to the continental collision between Indian and Asian plates. We present zircon U–Pb–Hf isotopes, whole‐rock geochemistry, and Sr–Nd isotopes for the intrusions from Maizhokunggar, southern Lhasa Terrane. The zircon U–Pb dating indicates that two episodes of magmatism occurred in the Maizhokunggar region, ca. 70 Ma diorites and ca. 60 Ma granitoids. The ca. 70 Ma diorites are medium‐K calc‐alkaline and characterized by pronounced high‐field‐strength element depletion and light rare earth element enrichment, similar to arc‐type rocks. They have homogeneous (87Sr/86Sr)i ratios (0.70378–0.70424) and εNd(t) values (+2.6 to +3.4), and εHf(t) (+5.9 to +13.0) with relatively young depleted mantle model ages (307–762 Ma), suggesting that they were generated from the juvenile mafic lower crust induced by the underplating of basaltic magmas from depleted mantle wedge. The ca. 60 Ma granitoids, Kajiacun (KJC) granodiorites, and Qulongxue (QLX) and Bangdacun (BDC) monzogranites are high‐K series and metaluminous to weakly peraluminous. The KJC granodiorites with high Sr/Y ratios (25–43) are adakitic and were likely derived from partial melting of a thickened lower crust. The BDC monzogranites have more evolved Sr–Nd–Hf isotopes and older Nd–Hf model ages than the QLX monzogranites. These geochemical variations were mainly controlled by the fractionation crystallization with assimilation of ancient crustal materials. We propose that at ca. 70 Ma, the subduction of the Neo‐Tethys oceanic slab triggered the partial melting of the juvenile lower crust and formed the diorites with arc affinity, and then the initial collision (>60 Ma) between the Indian and Asian plates caused locally thickened lower crust, resulting in adakitic granodiorites. Our study sheds light on the lithospheric scale magma evolution from the deep mantle to the shallow crust during the critical geodynamic transition to collision, and early uplift. [ABSTRACT FROM AUTHOR]

Purpose: Medication nonadherence is one of the most significant obstacles to tuberculosis (TB) control worldwide. Identification of the factors associated with medication nonadherence is important. However, few related studies have been carried out in Tibet. This study aimed to explore factors influencing medication nonadherence to pulmonary TB (PTB) treatment in Tibet, China, from the patient perspective. Patients and Methods: In this qualitative study, seventeen PTB patients in Tibet were recruited by purposive and maximum variation sampling methods. In-depth semistructured interviews were conducted to collect data on factors influencing medication nonadherence, and Colaizzi's seven-step method was used to analyze the data. Results: The medication nonadherence of PTB patients in Tibet was influenced by one or a combination of the following four factors. First, patient-related factors included a lack of knowledge of PTB treatment, poor self-management capability, poor self-regulation capability and misperception of health condition. Second, a medication-related factor was medication side effects. Third, health service-related factors included the poor treatment skills of doctors in primary hospitals and a lack of directly observed treatment (DOT). Last, sociocultural factors included the effect of traditional Tibetan medicine, lack of family member support and discrimination. Conclusion: Multiple interplaying factors influenced medication nonadherence during PTB treatment in Tibet, and the main influencing factors were a lack of knowledge about PTB treatment, poor self-management capability, and the effect of traditional Tibetan medicine. TB health workers in Tibet should provide permanently viewable PTB treatment knowledge materials to PTB patients when oral health education is conducted, find feasible alternative strategies to DOT and establish links to traditional Tibetan medicine hospitals. [ABSTRACT FROM AUTHOR]

Accurate landform classification is a crucial component of geomorphology. Although extensive classification efforts have been exerted based on the terrain factor, the scale analysis to describe the macro and micro landform features still needs standard measurement. To obtain the appropriate analysis scale of landform structure feature, and then carry out landform classification using the terrain texture, the texture feature is introduced for reflecting landform spatial differentiation and homogeneity. First, applying the ALOS World 3D-30m (AW3D30) DEM and selecting typical landforms of the southwest Tibet Plateau, the discrete wavelet transform (DWT), which acts as the texture feature analysis method, is executed to dissect the multiscale structural features of the terrain texture. Second, through the structural indices of reconstructed texture images, the optimum decomposition scale of DWT is confirmed. Under these circumstances, wavelet coefficients and wavelet energy entropy are extracted as texture features. Finally, the random forest (RF) method is utilized to classify the landform. Results indicate that the texture feature of DWT can achieve higher classification accuracy, which increases by approximately 11.8% compared with the gray co-occurrence matrix (GLCM). [ABSTRACT FROM AUTHOR]

The Lancang River (Upper Mekong) is a key large river in Asia with a prominent knickzone over 500 km distance (27.5‐30.7°N), as it descends the southeastern margin of the Tibetan Plateau. To explore the role of tectonics in regulating the river downcutting at regional and local scales, we reconstructed the rate and spatial pattern of incision within and below the knickzone. We combined the investigation of fluvial terraces with tributary river profile analysis for a 300-km reach near Yunlong below the knickzone (25–27.5°N). We conducted field mapping and dating of strath terraces at the heights of 60–380 m above the trunk river. The overlying terrace deposits comprise fluvial conglomerates and overbank sands as well as tributary alluvial fan conglomerates. K-feldspar post-infrared infrared stimulated luminescence (pIRIR) dating results suggest terrace formation during the Middle Pleistocene and the incision rate varying at <0.59–0.22 mm/yr. The river profiles of most tributaries in the study area are in a transient state with a knickpoint separating an upstream relict graded profile and a downstream steepened reach. These tributary profiles suggest river incision of ~50–1800 m, showing a spatial trend of increase towards the north. Knickpoint elevation and channel steepness of tributaries show a similar spatial pattern of northward increase. We suggest that the spatial variation in river incision along the Lancang River near Yunlong is likely to have been regulated by differential rock uplift in southeastern Tibet. Using the K-feldspar pIRIR dating method, we rectified the incision rate within the knickzone to vary at <0.63–0.28 mm/yr. New dating results thus suggest that terrace-derived incision rates along the Lancang River are similar to regional erosion rates on million-year and millennial time scales in terms of magnitude and spatial pattern. Coupled erosion rates on various time scales along the Lancang River and spatial pattern of river incision near Yunlong supports a primary role of tectonic forcing in shaping the southeastern Tibetan landscape. • River terraces and tributary river profiles used to quantify Lancang River incision. • River terraces used to quantify incision amount and rate since the Middle Pleistocene. • Profiles show spatial gradient in knickpoint elevation, steepness and incision amount. • Incision rate magnitude and spatial patterns in-keeping with regional erosion rates. • Incision patterns controlled by tectonically driven differential rock uplift. [ABSTRACT FROM AUTHOR]

Decoding interwoven tectonic and climatic drivers in global source-to-sink systems remains a major challenge in Earth science. This study demonstrates that the very wide shelf in the northern South China Sea acted as a critical discriminator of signals related to hinterland tectonism and basin rifting. The rifting process is the main driver of variations of detrital zircon (DZ) signals in the succession of the wide shelf. DZ data show an increasing proportion of intrabasinal sediment source that is in phase with seafloor spreading and crustal extension (ca. 32–16 Ma), and then a gradual increase of extrabasinal source until the Pleistocene, in step with post-rifting thermal subsidence. These DZ variations are free of the strongest Cenozoic tectonism, the uplift of the eastern Tibet-Himalayan orogen since ca. 23 Ma, although this regional uplift dominated the DZ-signal variations in the entire deep-water basinal areas of the northern South China Sea basins fed by the Central Canyon of the Qiongdongnan Basin. Moreover, rising of global sea-level driven by the Miocene Climatic Optimum had little impact on sediment delivery in the shelf-to-basin system. The strong decoupling of DZ-variation trends between the shelf and the deep basin in this study underscores the importance of wide shelves in distinguishing different allogenic drivers in global source-to-sink systems. • Basin rifting is the main driver on the provenance change in the shelf of South China Sea. • This provenance change is decoupled from the change in the basinal setting. • Wide shelf is an important discriminator for multiple drivers in source-to-sink systems. [ABSTRACT FROM AUTHOR]

[Display omitted] • New datas of minerals and petrology for the Yilashan chromitite. • Pyroxenite shows high PPGE/IPGE values, variable Pd/Ir (55.7–316.7), and left-leaning primitive mantle-normalized PGE pattern. • U-Pb age (162.8 ± 3.0 Ma) along with widely variable ε Hf (t) values (−9.2 to +12.0) of zircons recovered form a gabbroic. The Yilashan ophiolite in the southern part of the central Bangong-Nujiang suture zone comprises variably deformed harzburgite, dunite, and less abundant gabbro and pyroxenite pods and crosscutting veins. Cr-spinels in podiform chromitite bodies are characterized by high Cr# (64.3–74.3), high Mg# (58.2–67.5), and consistently low contents of TiO 2 (≤0.12 wt%). Primary melt calculations designate parental boninitic magmas with Al 2 O 3(liquid) contents of 11.67–13.49 wt%, and (FeO/MgO) liquid values of 0.92–1.12. Whole-rock geochemical data of fresh pyroxenite samples are characterized by negative K, Ta, Nb and Zr anomalies, no Eu anomaly, and chondrite-normalized REE patterns comparable to the N-MORB melts. The gabbro samples, in contrast, are high-K calc-alkaline, with elevated contents of LILE (Rb, K, Th) and depleted HFSE (i.e., Nb, Ta, P, Ti), consistent with subduction-related magmas. The fractionated chondrite-normalized REE patterns, high LREE/HREE values, and negative Eu anomalies of these gabbroic rocks are similar to the island arc basalts. Pyroxenite shows high PPGE/IPGE values, variable Pd/Ir (55.7–316.7), and left-leaning primitive mantle-normalized PGE pattern, whereas massive chromitite is enriched in IPGE relative to PPGE. The PGE patterns of pyroxenite and chromitite, though distinct, depict significant fractionation and partial melting in their formation. The elevated contents of PPGEs in pyroxenite suggest derivation from sulfur-saturated magmas as chromitite crystallization scavenged the compatible IPGEs from the parental melt. This assumption is supported by clinopyroxene in pyroxenite with variable Al 2 O 3 contents and variable Cr 2 O 3 contents (0.32 to 0.73 wt%). For the fractionated gabbro unit, zircons yielding a concordia U-Pb age of 162.8 ± 3.0 Ma and widely variable ε Hf (t) values (−9.2 to +12.0) suggest formation from heterogenous or reworked source materials during a Middle Jurassic subduction increment in the Neo-Tethyan Ocean. [ABSTRACT FROM AUTHOR]

The topographic evolution of SE Tibet is essential for understanding the growth of this orogenic plateau margin and the mechanism of continental deformation in general. Stable isotopes have been used to construct the paleo-elevation of SE Tibet during the Cenozoic. However, this methodology's reliability for the region is controversial; the results require validation through other independent constraints. The Eocene-Oligocene adakite-like rocks exposed along the Jinshajiang Suture are mostly the production of melts from the lower crust, and thus their geochemical features are used to track ancient crustal thickness and plateau elevation of SE Tibet. The whole-rock [La/Yb] N ratios indicate a thickened SE Tibet. Meanwhile, the paleo-elevation based on the calculated crustal thickness shows that central and southeastern Tibet had reached modern heights by the early Oligocene, corroborating results by stable isotope paleoaltimetry. Synthesizing previous studies and our results, we suppose that the deformation caused by the India-Aisa collision had propagated to and thickened central and southeastern Tibet before the Eocene-Oligocene. The uplifted and low-gradient plateau margin of SE Tibet had already been formed by this time. The lateral extrusion has mainly accommodated the deformation with minor shortening since the late Eocene. • Eocene-Oligocene adakite-like rocks exposed in SE Tibet were derived from melts in the deep crust. • Whole-rock La/Yb ratio-derived Moho depth indicates a thickened SE Tibet during the late Eocene-early Oligocene. • The paleo-elevation of SE Tibet had reached modern heights before the early Oligocene. [ABSTRACT FROM AUTHOR]