Prevalence and risk factors associated with tuberculosis mortality in Brunei Darussalam

Objective:To determine the prevalence and risk factors associated with tuberculosis mortality in Brunei Darussalam and to explore its underlying causes.Methods:A retrospective cohort study was conducted where data on socio-demographics,clinical characteristics and treatment outcomes of all tuberculosis patients registered at the National tuberculosis Coordinating Centre between 2013 and 2017 were collected.Overall tuberculosis mortality and the proportion of tuberculosis-related deaths were calculated.Logistic regression analysis was used to determine the risk factors of tuberculosis mortality when compared to those who are cured and/or completed tuberculosis treatment.Results:Of 1107 tuberculosis cases,99 died,giving an overall tuberculosis mortality rate of 8.9%(95%CI 7.4%-10.8%).Significant risk factors associated with tuberculosis mortality were age≥40 years(adjusted OR for 40-59 years was 3.89;95%CI 1.13-1.69;adjusted OR for≥60 years was 22.3;95%CI 7.27-91.9,using 20-39 years as reference),female sex(adjusted OR 1.74;95%CI 1.09-2.79),having renal disease(adjusted OR 25.7;95%CI 2.82-191.50)and having any cancers(adjusted OR 3.61;95%CI 1.26-10.00).The majority(75.8%)of the recorded deaths were not related to tuberculosis.Conclusions:Tuberculosis patients who were older than 40 years,female,and having renal disease and any cancer will need close monitoring in their management program to prevent tuberculosis mortality.Clinicians should also focus on other non-tuberculosis aspects of the patient’s medical history.

Latent tuberculosis infection in health-care workers in the government sector in Brunei Darussalam:A cross-sectional study

Objective:Health-care workers(HCWs)are known to be at high risk for occupational biological hazards,and this includes exposure to mycobacterium tuberculosis(TB)which can result in either active or latent TB infection(LTBI).This study aims to provide an overview of the incidence of LTBI among HCWs in Brunei Darussalam,to examine associated risk factors,and to evaluate LTBI treatment compliance.Materials and Methods:This is a retrospective cross-sectional study which was conducted using data from January 2018 to December 2021,on notified cases of LTBI in HCWs which identified 115 cases.Demographic data,underlying medical conditions,and compliance to treatment were assessed through reviews of their electronic health records.Results:The incidence of LBTI was 14.6/year/1000 HCWs.The incidence rate reached a high of 24.6/1000 in 2020,and majority of cases were in the older age groups.There was good treatment acceptance and compliance(82.6%),and this was observed to be significantly higher in females than males(P=0.02).Conclusion:This study showed an average incidence of LTBI of 14.6/1000 HCWs over 4 years and high LTBI treatment acceptance(82.6%)and compliance.Emphasis on infection prevention and control measures in health-care settings and actions to increase awareness of LTBI are crucial interventions toward reducing the burden of LTBI.

Knowledge, attitudes and practice survey on Zika virus infection among pregnant women in Brunei Darussalam

To assess the knowledge, attitudes, and practices(KAP) on Zika virus infection among pregnant women in Brunei Darussalam by a cross-sectional survey. Methods: Between February and June 2017, we recruited 234 pregnant women from all government healthcare centres at Brunei-Muara district, using a modified systematic sampling approach. A pre-tested and self-administered questionnaire was used and data analysis was conducted using descriptive statistics and multiple logistic regression analyses. Results: The study participants were mainly Malay(87.2%) and their mean age was 28.0 years. The median knowledge score was 13, out of a possible score of 28. Most participants(92.7%) knew that Zika virus was transmitted by mosquito bites whereas some(34.6%) knew that sexual transmission was also possible. Media(radio, television or newspapers) was the preferred source of updated information on Zika virus, followed by healthcare workers(44.0%), government announcements(43.2%), and social media(38.0%). Pregnant women who were 25 years old or older [Adj. OR=3.62(95% CI: 1.57, 9.51)], not Malays [Adj. OR=3.32(95% CI: 1.35, 8.55)], and had an average monthly household income of more than BND $3 000 [Adj. OR=4.06(95% CI: 1.81, 19.44)] were more likely to score higher for knowledge on Zika virus. The median prevention practice score was 23, out of a possible score of 36. Most participants reported wearing covering clothes(98.3%) and kept their living surroundings clean(99.6%). Most participants(88.0%) agreed that Zika is an important issue in their community. Conclusion: We found a lack of knowledge on Zika virus infection among pregnant women attending government maternal and child healthcare centres in Brunei Darussalam, in particular that Zika virus can be sexually transmitted. Such information could be well disseminated at the healthcare centre level. Health literacy studies should be conducted to understand the facilitators and barriers of KAP on Zika virus infection among pregnant women.

Forest structure and carbon dynamics of an intact lowland mixed dipterocarp forest in Brunei Darussalam

Tropical forests play a critical role in mitigating climate change because they account for large amount o terrestrial carbon storage and productivity.However,there are many uncertainties associated with the estimation o carbon dynamics.We estimated forest structure and carbon dynamics along a slope（17.3°–42.8°）and to assess the relations between forest structures,carbon dynamics,and slopes in an intact lowland mixed dipterocarp forest,in Kuala Belalong,Brunei Darussalam.Living biomass,basa area,stand density,crown properties,and tree family composition were measured for forest structure.Growth rate,litter production,and litter decomposition rates were also measured for carbon dynamics.The crown form index and the crown position index were used to assess crown properties,which we categorized into five stages,from very poor to perfect.The living biomass,basal area and stand density were 261.5–940.7 Mg ha-1,43.6–63.6 m2ha-1and 6,675–8400 tree ha-1,respectively.The average crown form and position index were 4,which means that the crown are mostly symmetrical and sufficiently exposed for photosynthesis.The mean biomass growth rate,litter production,litter decomposition rate were estimated as11.9,11.6 Mg ha-1a-1,and 7.2 g a-1,respectively.Biomass growth rate was significantly correlated with living biomass,basal area,and crown form.Crown form appeared to strongly influence living biomass,basal area and biomass growth rate in terms of light acquisition.However,basal area,stand density,crown properties,and biomass growth rate did not vary by slope or tree family composition.The results indicate that carbon accumulation by tree growth in an intact lowland mixed dipterocarp forest depends on crown properties.Absence of any effect of tree family composition on carbon accumulation suggests that the main driver of biomass accumulation in old-growth forests of Borneo is not species-specific characteristics of tree species.

Ethnobotanical review and pharmacological properties of selected medicinal plants in Brunei Darussalam:Litsea elliptica,Dillenia suffruticosa,Dillenia excelsa,Aidia racemosa,Vitex pinnata and Senna alata

The aim of the current study is to review the medicinal properties of the plants found in Brunei Darussalam namely Litsea elliptica, Dillenia suffruticosa, Dillenia excelsa, Aidia racemosa, Vitex pinnata and Senna alata. The known phytochemical constituents of these plants and their ability to bring about a range of biological activities are included in this review. These plants have been used traditionally for a multitude of diseases and illnesses. There is a lot of untapped potential in these medicinal plants which could cure multiple diseases.

Chronic kidney disease in children and adolescents in Brunei Darussalam

AIM: To determine epidemiology of Bruneian paediatric chronic kidney disease(CKD) patients and factors that affect growth and progression of disease. METHODS: A cross-sectional study conducted on all children below 18 years old who were diagnosed with CKD over a ten year period(2004 to 2013). The reference population was all children(< 18 years old) suffering from CKD and attending the tertiary paediatric nephrology clinic in Brunei Darussalam. Demographic(current age, age of diagnosis, gender, ethnicity), anthropometric(weight and height), diagnosis, laboratory data(serum creatinine and haemoglobin, urinalysis) and blood pressure were extracted from the patients' clinical case notes and recorded using a data collection form. RESULTS: The study revealed a high national prevalence [736 per million child population(pmcp)] and incidence(91 pcmp) of CKD. If CKD was defined at Stage 1, 2, 3, 4 or 5, the associated prevalence figures were 736, 132, 83, 50 and 33 pmcp. Glomerulonephritis accounted for 69% of all prevalent cases, followed by congenital abnormalities of kidney and urinary tract(20%) and tubulointerstitial diseases(8%). Minimal change disease being the most common histological diagnosis. The median age of diagnosis was 4.5 years, with congenital disease patients experiencing an earlier onset of diagnosis. A large proportion of patients were below the 5% percentile for height and weight. Non-glomerular diseases, adolescent and female patients were significantly associated with poor growth, but not glomerular filtration rate, age of diagnosis or steroid usage. CONCLUSION: Brunei has a high prevalence of chronic kidney disease in the paediatric population with glomerulonephritis being the most common disease.

Ultrahydrophobic melamine sponge via interfacial modification with reduced graphene oxide/titanium dioxide nanocomposite and polydimethylsiloxane for oily wastewater treatment

Three-dimensional(3D)porous absorbents have attracted significant attention in the oily wastewater treatment technology due to their high porosity and elasticity.Given their amphiphilic surface,they have a propensity to simultaneously absorb water and oil,which restricts their range of applications.In this study,a reduced graphene oxide and titanium dioxide nanocomposite(rGO/TiO_(2))was used to fabricate an ultra-hydrophobic melamine sponge(MS)through interfacial modification using a solution immersion technique.To further modify it,poly-dimethylsiloxane(PDMS)was grafted onto its surface to establish stronger covalent bonds with the composite.The water contact angle of the sponge(rGO/TiO_(2)/PDMS/MS)was 164.2°,which satisfies the condition for ultrahydrophobicity.The evidence of its water repellency was demonstrated by the Cassie-Baxter theory and the lotus leaf effect.As a result of the increased density of rGO/TiO_(2)/PDMS/MS,it recorded an initial capacity that was 2 g/g lower than the raw MS for crude oil absorption.The raw MS retained 53% of its initial absorption capacity after 20 cycles of absorption,while rGO/TiO_(2)/PDMS/MS retained 97%,suggesting good recyclability.Excellent oil and organic solvent recovery(90%-96%)was demonstrated by rGO/TiO_(2)/PDMS/MS in oil-water combinations.In a continuous separation system,it achieved a remarkable separation efficiency of 2.4×10^(6)L/(m^(3)·h),and in turbulent emulsion separation,it achieved a demulsification efficiency of 90%-91%.This study provides a practical substitute for massive oil spill cleaning.

Reservoir quality of the Late Cretaceous Volador Formation of the Latrobe group,Gippsland Basin,Australia:Implications from integrated analytical techniques

Increasing demand for energy due to the populous Eastern Australia has driven oil and gas industries to find new sources of hydrocarbons as they are the primary energy suppliers.Intensive study has been done on the Volador Formation in the Gippsland Basin by means of core-based petrophysical,sedimentological,and petrographic analyses as well as well log-based interpretation and capillary pressure test.Five wells from Kipper,Basker and Tuna fields with available dataset were investigated in this study:Kipper-1,Basker-1,Basker-2,Basker-5 and Tuna-4.Overall,the formation has good reservoir quality based on the high porosity and permeability values obtained through core and well log petrophysical analyses.The formation made up of mostly moderate to coarse quartz grains that has experienced strong anti-compaction and is poorly cemented.Montmorillonite and illite clays are seen dispersed in the rock formation,with the minority being mixed clays.These clays and diagenetic features including kaolinite cement and quartz overgrowth that can lead to porosity reduction only have insignificant impact on the overall reservoir quality.In addition,capillary pressure data shows that most samples are found in the transition to good reservoir zones(<50%saturation).The results obtained from this study have shown that the Volador Formation in the Gippsland Basin is worth for hydrocarbon exploration.

3D reservoir characterization of the Mangahewa Formation,Mangahewa Field,Taranaki Basin,New Zealand

The Mangahewa Formation is the primary reservoir target in the Mangahewa Field in the Taranaki Basin,New Zealand.This formation is distinguished by its marginal marine substantial tight-sand reservoir,having thickness exceeding 800 m.The aim of this study is to assess the reservoir properties of the Mangahewa Formation through 3D reservoir modeling,employing 3D seismic data,core data,and well data from the Mangahewa Field.Utilizing variance attributes,the faults and horizons have been identified successfully within the field.The majority of the interpreted faults exhibit dip angles exceeding 60,with a maximum displacement of 118 m.To detect direct hydrocarbon indicators,root-mean-square amplitude seismic attribute,envelope,and generalized spectral decomposition techniques have been employed.Subsequently,four lithofacies,comprising 78.3%sandstone,9.2%siltstone,9.5%claystone,and 3.0%coal have been established by utilizing the Sequential Indicator Simulation(SIS)algorithm to create a lithofacies model.A property model has been generated using the Sequential Gaussian Simulation(SGS)algorithm.Petrophysical evaluation indicates that the Mangahewa Formation exhibits reservoir qualities ranging from fair to good,with porosity levels between 8%and 11%,permeability averaging up to 10 mD,variable shale volumes,and hydrocarbon saturation in the range of 40%e50%.This study's methodologies and findings can serve as a valuable foundation for similar investigations in other tightsand gas fields located in different regions.

Reservoir quality evaluation of the Narimba Formation in Bass Basin,Australia:Implications from petrophysical analysis,sedimentological features,capillary pressure and wetting fluid saturation

The evaluation of reservoir quality was accomplished on the Late Paleocene to Early Eocene Narimba Formation in Bass Basin,Australia.This study involved combination methods such as petrophysical analysis,petrography and sedimentological studies,reservoir quality and fluid flow units from derivative parameters,and capillary pressure and wetting fluid saturation relationship.Textural and diagenetic features are affecting the reservoir quality.Cementation,compaction,and presence of clay minerals such as kaolinite are found to reduce the quality while dissolution and secondary porosity are noticed to improve it.It is believed that the Narimba Formation is a potential reservoir with a wide range of porosity and permeability.Porosity ranges from 3.1%to 25.4%with a mean of 15.84%,while permeability ranges between 0.01 mD and 510 mD,with a mean of 31.05 mD.Based on the heterogenous lithology,the formation has been categorized into five groups based on permeability variations.Group I showed an excellent to good quality reservoir with coarse grains.The impacts of both textural and diagenetic features improve the reservoir and producing higher reservoir quality index(RQI)and flow zone indicators(FZI)as well as mostly mega pores.The non-wetting fluid migration has the higher possibility to flow in the formation while displacement pressure recorded as zero.Group II showed a fair quality reservoir with lower petrophysical properties in macro pores.The irreducible water saturation is increasing while the textural and digenetic properties are still enhancing the reservoir quality.Group III reflects lower quality reservoir with mostly macro pores and higher displacement pressure.It may indicate smaller grain size and increasing amount of cement and clay minerals.Group IV,and V are interpreted as a poor-quality reservoir that has lower RQI and FZI.The textural and digenetic features are negatively affecting the reservoir and are leading to smaller pore size and pore throat radii(r35)values to be within the range of macro,meso-,micro-,and nano pores.The capillary displacement pressure curves of the three groups show increases reaching the maximum value of 400 psia in group V.Agreement with the classification of permeability,r35 values,and pore type can be used in identifying the quality of reservoir.

Salivary leptin concentrations in Bruneian secondary school children

Objective:To investigate the association between leptin levels and body mass index in Bruneian secondary school students.Methods:The body mass index of Bruneian secondary school students(aged 11–18years) was determined before collecting their saliva using the passive drool technique.Salivary leptin concentration was determined by ELISA.Results:Correlation and partial correlation(controlled for age) analyses showed no significant differences between the levels of salivary leptin of normal weight and overweight students.Conclusions:No significant increase in the salivary leptin concentration was observed in overweight compared with normal weight Bruneian secondary school students.

Chained Dual-Generative Adversarial Network:A Generalized Defense Against Adversarial Attacks

Neural networks play a significant role in the field of image classification.When an input image is modified by adversarial attacks,the changes are imperceptible to the human eye,but it still leads to misclassification of the images.Researchers have demonstrated these attacks to make production self-driving cars misclassify StopRoad signs as 45 Miles Per Hour(MPH)road signs and a turtle being misclassified as AK47.Three primary types of defense approaches exist which can safeguard against such attacks i.e.,Gradient Masking,Robust Optimization,and Adversarial Example Detection.Very few approaches use Generative Adversarial Networks(GAN)for Defense against Adversarial Attacks.In this paper,we create a new approach to defend against adversarial attacks,dubbed Chained Dual-Generative Adversarial Network(CD-GAN)that tackles the defense against adversarial attacks by minimizing the perturbations of the adversarial image using iterative oversampling and undersampling using GANs.CD-GAN is created using two GANs,i.e.,CDGAN’s Sub-ResolutionGANandCDGAN’s Super-ResolutionGAN.The first is CDGAN’s Sub-Resolution GAN which takes the original resolution input image and oversamples it to generate a lower resolution neutralized image.The second is CDGAN’s Super-Resolution GAN which takes the output of the CDGAN’s Sub-Resolution and undersamples,it to generate the higher resolution image which removes any remaining perturbations.Chained Dual GAN is formed by chaining these two GANs together.Both of these GANs are trained independently.CDGAN’s Sub-Resolution GAN is trained using higher resolution adversarial images as inputs and lower resolution neutralized images as output image examples.Hence,this GAN downscales the image while removing adversarial attack noise.CDGAN’s Super-Resolution GAN is trained using lower resolution adversarial images as inputs and higher resolution neutralized images as output images.Because of this,it acts as an Upscaling GAN while removing the adversarial attak noise.Furthermore,CD-GAN has a modular design such that it can be prefixed to any existing classifier without any retraining or extra effort,and 2542 CMC,2023,vol.74,no.2 can defend any classifier model against adversarial attack.In this way,it is a Generalized Defense against adversarial attacks,capable of defending any classifier model against any attacks.This enables the user to directly integrate CD-GANwith an existing production deployed classifier smoothly.CD-GAN iteratively removes the adversarial noise using a multi-step approach in a modular approach.It performs comparably to the state of the arts with mean accuracy of 33.67 while using minimal compute resources in training.

太阳能集热器强化传热技术的局限性与挑战

目前,太阳能集热器在可再生能源领域发挥着至关重要的作用,这在核心能源专家和研究界得到了广泛的认可。由于这种太阳能收集技术的高能量转换率,迫切需要评价方法,以期改善传热过程。前期研究人员主要致力于工作流体的增强上,而忽略了其他同样有助于增强太阳能集热器传热过程的技术,这使得其他方向的研究逐渐过时了。本研究的主要目的是提供最新的进展和方法,以加强太阳能集热器的传热过程的最新概述。研究了传统技术和创新技术,探讨了它们在提高热性能和整体系统效率方面的有效性。对太阳能集热器强化传热技术的最新研究进行了全面的文献综述。确定了主要挑战、知识差距和局限性,并推荐了潜在的未来研究方案。这篇全面的综述将作为研究人员和主要能源参与者的指南,为太阳能集热器领域提供参考的研究方向。

Automatic Clustering of User Behaviour Profiles for Web Recommendation System

Web usage mining,content mining,and structure mining comprise the web mining process.Web-Page Recommendation(WPR)development by incor-porating Data Mining Techniques(DMT)did not include end-users with improved performance in the obtainedfiltering results.The cluster user profile-based clustering process is delayed when it has a low precision rate.Markov Chain Monte Carlo-Dynamic Clustering(MC2-DC)is based on the User Behavior Profile(UBP)model group’s similar user behavior on a dynamic update of UBP.The Reversible-Jump Concept(RJC)reviews the history with updated UBP and moves to appropriate clusters.Hamilton’s Filtering Framework(HFF)is designed tofilter user data based on personalised information on automatically updated UBP through the Search Engine(SE).The Hamilton Filtered Regime Switching User Query Probability(HFRSUQP)works forward the updated UBP for easy and accuratefiltering of users’interests and improves WPR.A Probabilistic User Result Feature Ranking based on Gaussian Distribution(PURFR-GD)has been developed to user rank results in a web mining process.PURFR-GD decreases the delay time in the end-to-end workflow for SE personalization in various meth-ods by using the Gaussian Distribution Function(GDF).The theoretical analysis and experiment results of the proposed MC2-DC method automatically increase the updated UBP accuracy by 18.78%.HFRSUQP enabled extensive Maximize Log-Likelihood(ML-L)increases to 15.28%of User Personalized Information Search Retrieval Rate(UPISRT).For feature ranking,the PURFR-GD model defines higher Classification Accuracy(CA)and Precision Ratio(PR)while uti-lising minimum Execution Time(ET).Furthermore,UPISRT's ranking perfor-mance has improved by 20%.

Multivariate Aggregated NOMA for Resource Aware Wireless Network Communication Security

NonorthogonalMultiple Access(NOMA)is incorporated into the wireless network systems to achieve better connectivity,spectral and energy effectiveness,higher data transfer rate,and also obtain the high quality of services(QoS).In order to improve throughput and minimum latency,aMultivariate Renkonen Regressive Weighted Preference Bootstrap Aggregation based Nonorthogonal Multiple Access(MRRWPBA-NOMA)technique is introduced for network communication.In the downlink transmission,each mobile device’s resources and their characteristics like energy,bandwidth,and trust are measured.Followed by,the Weighted Preference Bootstrap Aggregation is applied to recognize the resource-efficient mobile devices for aware data transmission by constructing the different weak hypotheses i.e.,Multivariate Renkonen Regression functions.Based on the classification,resource and trust-aware devices are selected for transmission.Simulation of the proposed MRRWPBA-NOMA technique and existing methods are carried out with different metrics such as data delivery ratio,throughput,latency,packet loss rate,and energy efficiency,signaling overhead.The simulation results assessment indicates that the proposed MRRWPBA-NOMA outperforms well than the conventional methods.

Reservoir quality evaluation using sedimentological and petrophysical characterization of deep-water turbidites:A case study of Tariki Sandstone Member,Taranaki Basin,New Zealand

The current study aims to ascertain the reservoir characteristics of the Tariki Sandstone Member of the Otaraoa Formation,Taranaki Basin,New Zealand.This study was carried out by integrating the comprehensive petrophysical evaluation,sedimentological and petrographic studies,as well as well log analysis by using data from six wells.The porosity-permeability relationship is used to divide the samples of the Tariki Sandstone Member into reservoir and non-reservoir facies.A thorough petrophysical analysis shows that the maximum porosity values fluctuate between 16.6%and 22.1%,while permeability ranges from 102 mD to 574 mD,which indicates fair to good reservoir quality.Moreover,the Tariki sandstone represents six hydraulic flow units with a high reservoir quality index and flow zone indicator representing good reservoir characteristics.The pore size varies between nano and megapores with dominant macropores.Based on the sedimentological and petrographic analysis,the Tariki Sandstone Member is classified as a combination of subarkose,arkose,and lithic arkose with fine to medium and moderately to moderately well-sorted grains.The main diagenetic factor affecting the reservoir quality is cementation,which occupied all the pores with calcite.On the bright side,the secondary pores are developed due to the dissolution of calcite cement and few grains.The well log analysis demonstrates the presence of low clay volume ranging from 0.3%to 3.1%,fair to good effective porosity values between 13.6%and 15.9%,net pay thickness from 18.29 m to 91.44 m,and hydrocarbon saturation from 56%to 77.9%.The findings from this study revealed that the Tariki Sandstone Member possesses fair to good reservoir quality and hydrocarbon potential,which indicate submarine fans as appealing hydrocarbon reservoirs.This study can be used in similar depositional environments elsewhere in the world.

西北太平洋海岸带大弹涂鱼复合体的隐存种与进化历史

大弹涂鱼Boleophthalmus pectinirostris间断分布于西太平洋海岸带东亚与马来西亚马六甲海峡,但马来西亚种群的分类地位尚存争议。研究使用线粒体ND5基因序列(718 bp)与核位点Rag1基因序列(1395 bp)对西北太平洋海岸带11个地点的45尾大弹涂鱼属鱼类进行系统发育关系重建,结果表明大弹涂鱼包括东亚与马来西亚两个单系群,两者形成姊妹群关系。GMYC分析、*BEAST物种树支持大弹涂鱼东亚谱系和马来西亚谱系是不同种。分子测定年龄分析表明大弹涂鱼东亚谱系与马来西亚谱系之间的分化时间为2.73百万年。因此,西北太平洋海岸带大弹涂鱼是复合体,包括两个物种:东亚种群是大弹涂鱼Boleophthalmus pectinirostris sensu stricto,而马来西亚种群是隐存种Boleophthalmus sp.。大弹涂鱼与隐存种之间的物种分化可能是晚上新世冰期海平面下降产生的地理隔离以及间冰期洋流对基因交流的阻碍两方面相互作用的结果。

Timing of carbonatite-hosted U-polymetallic mineralization in the supergiant Huayangchuan deposit,Qinling Orogen:Constraints from titanite U-Pb and molybdenite Re-Os dating

The newly-discovered supergiant Huayangchuan uranium(U)-polymetallic(Sr,Se,REEs,Ba,Nb and Pb)deposit is located in the Qinling Orogen,central China.The deposit underwent multistage mineralization,with the main carbonatite ore stage being the most important for the U,Nb,REE,Sr and Ba endowments.According to the mineral assemblages,the main carbonatite ore stage can be divided into three substages,i.e.,sulfate(Ba-Sr),alkali-rich U and REE-U mineralization.Main-stage titanite from the Huayangchuan igneous carbonatite are rich in high field strength elements(HFSEs,e.g.,Zr,Nb and REEs),and show clear elemental substitutions(e.g.,Ti vs.Nb+Fe+Al and Ca+Ti vs.Fe+Al+REE).High-precision LA-ICP-MS titanite dating yielded a U-Pb age of 209.0±2.9 Ma,which represents the mainstage mineralization age at Huayangchuan,and is coeval with the local carbonatite dyke intrusion.This mineralization age is further constrained by the Re-Os dating of molybdenite from the Huayangchuan carbonatite,which yielded a weighted mean age of 196.8±2.4 Ma.Molybdenite Re contents(337.55-392.75 ppm)and C-OSr-Nd-Pb isotopic evidence of the Huayangchuan carbonatite both suggest a mantle origin for the carbonatite.Our study supports that the Late Triassic carbonatite magmatism was responsible for the world-class U-Mo-REE mineralization in the Qinling Orogen,and that the regional magmatism and ore formation was likely caused by the closure of the Mianlue ocean and the subsequent North China-South China continent-continent collision.

Comparative Study on Growth Performance of Transgenic(Over-Expressed OsNHX1) and Wild-Type Nipponbare under Different Salinity Regimes

Transgenic Nipponbare which over-expressed a Na＋/H~ antiporter gene OsNHX1 was used to compare its growth performance, water status and photosynthetic efficiency with its wild type under varying salinity regimes. Chlorophyll content, quantum yield and photosynthetic rate were measured to assess the impact of salinity stress on photosynthetic efficiency for transgenic and wild-type Nipponbare. Effects of salinity on water status and gas exchange to both lines were studied by measuring water use efficiency, instantaneous transpiration rate and stomatal conductance. Dry shoot weight and leaf area were determined after three months of growth to assess the impacts of salinity on the growth of those two lines. Our study showed that both lines were affected by salinity stress, however, the transgenic line showed higher photosynthetic efficiency, better utilization of water, and better growth due to low transpiration rate and stomatal conductance. Reduction of photosynthetic efficiency exhibited by the wild-type Nipponbare was correlated to its poor growth under salinity stress.