Browsing by Author "Xu, J."

Now showing 1 - 4 of 4

Effectiveness of protected areas in preventing rubber expansion and deforestation in Xishuangbanna, Southwest China
(Land Degradation & Development, 2018) Sarathchandra, C.; Dossa, G.G.; Ranjitkar, N.B.; Chen, H.; Deli, Z.; Ranjitkar, S.; De Silva, K.H.W.L.; Wickramasinghe, S.; Xu, J.; Harrison, R.D.
Protected areas (PAs) are supposedly key refuges for the world's remaining biodiversity. Our study site, Xishuangbanna, harbors a high proportion of China's biodiversity but is threatened by rapid deforestation and expansion of monoculture rubber. We quantified the success of Xishuangbanna's PAs in preventing deforestation.Most previous analyses of PA effectiveness have insufficiently accounted for biases arising from PA location and establishment, because they overlooked the importance of site‐matching in accounting for landscape change.We used matching methods to minimize such biases in comparing land use conversion rates inside and outside‐PAs. By 2010, Xishuangbanna had 3,455.5 km2 (~18%) designated as PAs. However, rubber occupied 22% of its land area and was expanding at a rate of 153.4 km2/year. Between 1988 and 2010, conventional analysis showed a deforestation rate of 9.3 km2/year. However, matching analysis showed a significantly higher rate of deforestation, 10.7 km2/year, which resulted in the deforestation of ~11% of PA's land. We argue that PAs were less effective than had previously been thought. The situation worsened from 2002 to 2010, when the deforestation rate within PAs was actually higher than that of outside PAs, although this difference was not significant. The designated higher levels of protection in ‘core’ zones were also unsuccessful in preventing deforestation. At current rates, within the next 50 years, a further 16% of PAs would be deforested in Xishuangbanna. This could even be an underestimate, as without intervention, drivers of deforestation tend to accelerate. Therefore, reviewing and strengthening current PA management policies is essential.
A Functional element necessary for fetal hemoglobin silencing
(Massachusetts Medical Society, 2011) Sankaran, V.G.; Xu, J.; Byron, R.; Greisman, H.A.; Fisher, C.; Weatherall, D.J.; Sabath, D.E.; Groudine, M.; Orkin, S.H.; Premawardhena, A.; Bender, M.A.
BACKGROUND: An improved understanding of the regulation of the fetal hemoglobin genes holds promise for the development of targeted therapeutic approaches for fetal hemoglobin induction in the β-hemoglobinopathies. Although recent studies have uncovered trans-acting factors necessary for this regulation, limited insight has been gained into the cis-regulatory elements involved. METHODS: We identified three families with unusual patterns of hemoglobin expression, suggestive of deletions in the locus of the β-globin gene (β-globin locus). We performed array comparative genomic hybridization to map these deletions and confirmed breakpoints by means of polymerase-chain-reaction assays and DNA sequencing. We compared these deletions, along with previously mapped deletions, and studied the trans-acting factors binding to these sites in the β-globin locus by using chromatin immunoprecipitation. RESULTS: We found a new (δβ)(0)-thalassemia deletion and a rare hereditary persistence of fetal hemoglobin deletion with identical downstream breakpoints. Comparison of the two deletions resulted in the identification of a small intergenic region required for γ-globin (fetal hemoglobin) gene silencing. We mapped a Kurdish β(0)-thalassemia deletion, which retains the required intergenic region, deletes other surrounding sequences, and maintains fetal hemoglobin silencing. By comparing these deletions and other previously mapped deletions, we elucidated a 3.5-kb intergenic region near the 5' end of the δ-globin gene that is necessary for γ-globin silencing. We found that a critical fetal hemoglobin silencing factor, BCL11A, and its partners bind within this region in the chromatin of adult erythroid cells. CONCLUSIONS: By studying three families with unusual deletions in the β-globin locus, we identified an intergenic region near the δ-globin gene that is necessary for fetal hemoglobin silencing. (Funded by the National Institutes of Health and others.).
Spatial Variation in Trophic Structure of Dominant Fish Species in Lake Dongting, China during Dry Season
(Water, 2018) Yu, J.; Guo, L.; Zhang, H.; Xu, J.; Hu, H.; Xue, T; Luo, C.; Yi, C.; Hu, Y.; De Silva, K.; Xie, P.
Understanding trophic interactions in food webs is crucial to revealing the transfer of substances and energy from primary food sources to consumers in aquatic ecosystems. We hypothesize that the trophic structure of consumers can be significantly affected by primary food sources (pelagic, benthic, and littoral sources) through complex trophic interactions. This study used stable isotope analysis and Bayesian mixing models to estimate the trophic levels of fish consumers and the contributions of primary food sources in the three sub-lakes (Eastern, Southern, and Western Dongting) of Lake Dongting, which have different physical and chemical parameters of water, fish species diversity, and plankton (phytoplankton and zooplankton) density. Results showed the differences in community structures of fish among sub-lakes. Fish trophic levels were significantly higher in Eastern Dongting than those in the two other areas. The contributions of primary food sources to fishes were as follows: the pelagic source was the main basal food source in Eastern Dongting, and littoral and pelagic sources played equally essential roles in Southern Dongting; fishes in Western Dongting relied on more benthic source to growth than those in the two other regions. This study can fill gaps in our knowledge of the influence of the underlying food available on trophic structure of consumers by exploring the role of primary food sources and making the trophic structure of consumers in the aquatic food web highly complicated and diverse through control of the distribution of primary food sources.
The third intensive care bundle with blood pressure reduction in acute cerebral haemorrhage trial (INTERACT3): an international, stepped wedge cluster randomised controlled trial
(Elsevier, 2023) Ma, L.; Hu, X.; Song, L.; Chen, X.; Ouyang, M.; Billot, L.; Li, Q.; Malavera, A.; Li, X.; Muñoz-Venturelli, P.; de Silva, A.; Thang, N.H.; Wahab, K.W.; Pandian, J.D.; Wasay, M.; Pontes-Neto, O.M.; Abanto, C.; Arauz, A.; Shi, H.; Tang, G.; Zhu, S.; She, X.; Liu, L.; Sakamoto, Y.; You, S.; Han, Q.; Crutzen, B.; Cheung, E.; Li, Y.; Wang, X.; Chen, C.; Liu, F.; Zhao, Y.; Li, H.; Liu, Y.; Jiang, Y.; Chen, L.; Wu, B.; Liu, M.; Xu, J.; You, C.; Anderson, C.S.; INTERACT3 Investigators
BACKGROUND: Early control of elevated blood pressure is the most promising treatment for acute intracerebral haemorrhage. We aimed to establish whether implementing a goal-directed care bundle incorporating protocols for early intensive blood pressure lowering and management algorithms for hyperglycaemia, pyrexia, and abnormal anticoagulation, implemented in a hospital setting, could improve outcomes for patients with acute spontaneous intracerebral haemorrhage. METHODS: We performed a pragmatic, international, multicentre, blinded endpoint, stepped wedge cluster randomised controlled trial at hospitals in nine low-income and middle-income countries (Brazil, China, India, Mexico, Nigeria, Pakistan, Peru, Sri Lanka, and Viet Nam) and one high-income country (Chile). Hospitals were eligible if they had no or inconsistent relevant, disease-specific protocols, and were willing to implement the care bundle to consecutive patients (aged ≥18 years) with imaging-confirmed spontaneous intracerebral haemorrhage presenting within 6 h of the onset of symptoms, had a local champion, and could provide the required study data. Hospitals were centrally randomly allocated using permuted blocks to three sequences of implementation, stratified by country and the projected number of patients to be recruited over the 12 months of the study period. These sequences had four periods that dictated the order in which the hospitals were to switch from the control usual care procedure to the intervention implementation of the care bundle procedure to different clusters of patients in a stepped manner. To avoid contamination, details of the intervention, sequence, and allocation periods were concealed from sites until they had completed the usual care control periods. The care bundle protocol included the early intensive lowering of systolic blood pressure (target <140 mm Hg), strict glucose control (target 6·1-7·8 mmol/L in those without diabetes and 7·8-10·0 mmol/L in those with diabetes), antipyrexia treatment (target body temperature ≤37·5°C), and rapid reversal of warfarin-related anticoagulation (target international normalised ratio <1·5) within 1 h of treatment, in patients where these variables were abnormal. Analyses were performed according to a modified intention-to-treat population with available outcome data (ie, excluding sites that withdrew during the study). The primary outcome was functional recovery, measured with the modified Rankin scale (mRS; range 0 [no symptoms] to 6 [death]) at 6 months by masked research staff, analysed using proportional ordinal logistic regression to assess the distribution in scores on the mRS, with adjustments for cluster (hospital site), group assignment of cluster per period, and time (6-month periods from Dec 12, 2017). This trial is registered at Clinicaltrials.gov (NCT03209258) and the Chinese Clinical Trial Registry (ChiCTR-IOC-17011787) and is completed. FINDINGS: Between May 27, 2017, and July 8, 2021, 206 hospitals were assessed for eligibility, of which 144 hospitals in ten countries agreed to join and were randomly assigned in the trial, but 22 hospitals withdrew before starting to enrol patients and another hospital was withdrawn and their data on enrolled patients was deleted because regulatory approval was not obtained. Between Dec 12, 2017, and Dec 31, 2021, 10 857 patients were screened but 3821 were excluded. Overall, the modified intention-to-treat population included 7036 patients enrolled at 121 hospitals, with 3221 assigned to the care bundle group and 3815 to the usual care group, with primary outcome data available in 2892 patients in the care bundle group and 3363 patients in the usual care group. The likelihood of a poor functional outcome was lower in the care bundle group (common odds ratio 0·86; 95% CI 0·76-0·97; p=0·015). The favourable shift in mRS scores in the care bundle group was generally consistent across a range of sensitivity analyses that included additional adjustments for country and patient variables (0·84; 0·73-0·97; p=0·017), and with different approaches to the use of multiple imputations for missing data. Patients in the care bundle group had fewer serious adverse events than those in the usual care group (16·0% vs 20·1%; p=0·0098). INTERPRETATION: Implementation of a care bundle protocol for intensive blood pressure lowering and other management algorithms for physiological control within several hours of the onset of symptoms resulted in improved functional outcome for patients with acute intracerebral haemorrhage. Hospitals should incorporate this approach into clinical practice as part of active management for this serious condition. FUNDING: Joint Global Health Trials scheme from the Department of Health and Social Care, the Foreign, Commonwealth & Development Office, and the Medical Research Council and Wellcome Trust; West China Hospital; the National Health and Medical Research Council of Australia; Sichuan Credit Pharmaceutic and Takeda China.