Demographic variation and habitat specialization of tree species in a diverse tropical forest of Cameroon

Background： Many tree species in tropical forests have distributions tracking local ridge-slope-valley topography. Previous work in a 50-ha plot in Korup National Park, Cameroon, demonstrated that 272 species, or 63% of those tested, were significantly associated with topography. Methods： We used two censuses of 329,000 trees ≥1 cm dbh to examine demographic variation at this site that would account for those observed habitat preferences. We tested two predictions. First, within a given topographic habitat, species specializing on that habitat （＇residents＇） should outperform species that are specialists of other habitats （＇foreigners＇）. Second, across different topographic habitats, species should perform best in the habitat on which they specialize （＇home＇） compared to other habitats （＇away＇）. Species＇ performance was estimated using growth and mortality rates. Results： In hierarchical models with species identity as a random effect, we found no evidence of a demographic advantage to resident species. Indeed, growth rates were most often higher for foreign species. Similarly, comparisons of species on their home vs. away habitats revealed no sign of a performance advantage on the home habitat. Conclusions＂ We reject the hypothesis that species distributions along a ridge-valley catena at Korup are caused by species differences in trees _〉1 cm dbh. Since there must be a demographic cause for habitat specialization, we offer three alternatives. First, the demographic advantage specialists have at home occurs at the reproductive or seedling stage, in sizes smaller than we census in the forest plot. Second, species may have higher performance on their preferred habitat when density is low, but when population builds up, there are negative density-dependent feedbacks that reduce performance. Third, demographic filtering may be produced by extreme environmental conditions that we did not observe during the census interval.

Possibility of avoiding legumes-deriving boost of N 2 O emissions in tropical monoculture tree plantations

Recent reports warned that planting leguminous trees under monocultures elevates nitrous oxide(N2O)emissions through N-rich litter inputs.We hypothesized that planting trees on sandy soil can avoid the legume-derived boost of N2O emissions through limiting water availability for N2O production.Effects of planting legumes on methane(CH4)uptakes were also examined.N2O emissions and CH4uptakes were compared among five tropical tree plantation stands including three leguminous stands(Acacia auriculiformis,Acacia mangium,and Xylia xylocarpa)and two non-leguminous stands(Eucalyptus camaldulensis,and Hope a odorata).Due to lower water contents of the soil,the N2O fluxes in our study site were at the lower end of the tropical rain forests.As we hypothesized,no clear differences in N2O emissions were obs erved between leguminous and non-leguminous stands.CH4uptake rates in the present study were lower than those of other tropical forests.CH4uptakes in leguminous stands did not differ from those in non-leguminous stands.Overall,we demonstrated that planting leguminous trees on sandy soils has a potential to enable us to manage leguminous monoculture tree plantations without boosting N2O emissions or reducing CH4uptakes.

Dynamic Pricing of Tropical Fruits in Hainan Based on Internet of Things Technology

In recent years,the Internet of Things(IoT)technology has been widely used in the production and sales of tropical fruits,with strong practicability and wide application prospects.The tropical fruit dynamic pricing model based on the IoT technology can promote the healthy development of the tropical fruit industry in Hainan and ensure the income of fruit farmers.Based on IoT technology,the quality grade of tropical fruits in Hainan is obtained.According to the dynamic pricing strategy of revenue management,a dynamic pricing model based on the quality of tropical fruits and a dynamic pricing model based on consumer segmentation are established to study the dynamic pricing problem under the condition of maximum profit for tropical fruit sellers.The research results show that for different fruit quality and consumer groups,different pricing models are required for pricing,in order to get the maximum profit from tropical fruit sales.Sellers must flexibly adopt different dynamic pricing models to price tropical fruits to enhance the competitiveness of the tropical fruit industry.

Analysis of quality-related proteins in golden pompano(Trachinotus ovatus)fillets with modified atmosphere packaging under superchilling storage

Here,we aimed to study the changes in proteome of golden pompano fillets during post-mortem storage.Tandem mass tags(TMT)-labeled quantitative proteomic strategy was applied to investigate the relationships between protein changes and quality characteristics of modified atmosphere packaging(MAP)fillets during superchilling(-3°C)storage.Scanning electron microscopy was used to show that the muscle histology microstructure of fillets was damaged to varying degrees,and low-field nuclear magnetic resonance was used to find that the immobilized water and free water in the muscle of fillets changed significantly.Total sulfhydryl content,TCA-soluble peptides and Ca2+-ATPase activity also showed that the fillet protein had a deterioration by oxidation and denaturation.The Fresh(FS),MAP,and air packaging(AP)groups were set.Total of 150 proteins were identified as differential abundant proteins(DAPs)in MAP/FS,while 209 DAPs were in AP/FS group.The KEGG pathway analysis indicated that most DAPs were involved in binding proteins and protein turnover.Correlation analysis found that 52 DAPs were correlated with quality traits.Among them,8 highly correlated DAPs are expected to be used as potential quality markers for protein oxidation and water-holding capacity.These results provide a further understanding of the muscle deterioration mechanism of packaging golden pompano fillets during superchilling.

Insight into the quality deterioration induced by microorganisms in Litopenaeus vannamei during superchilling storage

Quality deterioration induced by microbial community in Litopenaeus vannamei during superchilling storage were demonstrated in this study.In this study,6 microorganisms were identified as the biomarkers by 16S rDNA sequencing and 71 differential metabolites were identified by untargeted metabolomics.The correlation analysis between microorganisms and differential metabolites revealed that Oceanicaulis,Aliihoeflea,Prauserella,Chelativorans and Pseudoalteromonas had the potential to be the important microorganisms of deterioration of superchilled shrimp.Moreover,the spearman correlation analysis revealed that lightness value had highly significant correlation with Shewanella(P<0.01),and thiobarbituric acid content,total viable count value,total sulfhydryl content,trichloroacetic acid-soluble peptide and Ca2+-ATPase activity showed significantly correlation with Oceanicaulis,Prauserella,Chelativorans,Aliihoefl ea and Pseudoalteromonas(P<0.05).This study offers a better understanding for mechanisms behind quality degradation induced by microorganisms,which may help the quality maintaining of Pacific white shrimp during superchilling storage.

Role of macroscopic on-site evaluation of endoscopic ultrasoundguided fine-needle aspiration/biopsy:Results of a multicentric prospective study

BACKGROUND The concept of macroscopic on-site evaluation(MOSE)was introduced in 2015 when the endoscopist observed better diagnostic yield when the macroscopically visible core on MOSE was superior to 4 mm.Recent studies suggest that MOSE by the endoscopist may be an excellent alternative to rapid on-site evaluation,and some classi-fications have been published.Few studies have assessed the adequacy of histologic cores in MOSE during endoscopic ultrasound-guided fine-needle aspiration/biopsy(EUS-FNA/FNB).AIM To evaluate the performance of MOSE during EUS-FNA/FNB.METHODS This multicentric prospective study was conducted in 16 centers in 3 countries(Egypt,Iraq,and Morocco)and included 1108 patients with pancreatic,biliary,or gastrointestinal pathology who were referred for EUS examination.We prospectively analyzed the MOSE in 1008 patients with available histopathological reports according to 2 classifications to determine the adequacy of the histological core samples.Data management and analysis were performed using a Statistical Package for Social Sciences(SPSS)version 27.RESULTS A total of 1074 solid lesions were biopsied in 1008 patients with available cytopathological reports.Mean age was 59 years,and 509 patients(50.5%)were male.The mean lesion size was 38 mm.The most frequently utilized needles were FNB-Franseen(74.5%)and 22 G(93.4%),with a median of 2 passes.According to 2 classifications,618 non-bloody cores(61.3%)and 964 good samples(95.6%)were adequate for histological evaluation.The overall diagnostic yield of cytopathology was 95.5%.The cytological examination confirmed the diagnosis of malignancy in 861 patients(85.4%),while 45 samples(4.5%)were inconclusive.Post-procedural adverse events occurred in 33 patients(3.3%).Statistical analysis showed a difference between needle types(P=0.035)with a high sensitivity of FNB(97%).The analysis of the relationship between the MOSE-score and the final diagnosis showed a significant difference between the different scores of the MOSE(P<0.001).CONCLUSION MOSE is a simple method that allows endoscopists to increase needle passes to improve sample quality.There is significantly higher FNB sensitivity and cytopathology diagnostic yield with good MOSE cores.

Standardization of harvesting age of bamboo shoots with respect to nutritional and anti-nutritional components

Bamboo shoots can be harvested at different ages but the data on the changes in nutritional composition with age are scanty. We standardized harvesting age of bamboo shoots in central India to obtain best quality produce with respect to nutritional composition. The shoots harvested on different days （2–20 days after emergence from ground） were analyzed for their nutritional （dietary fibres, carbohydrates, proteins, total phenols, ascorbic acid, sodium, potassium, phosphorus, calcium, magnesium and phenolic acids） and anti nutritional （cyanogen） constituents. A significant variation （at p ≤ 0.5） was observed in the nutritional composition of shoots of Dendrocalamus asper, D. strictus and Bambusa tulda harvested at different days. An overall decrease was observed in proteins and total phenols while dietary fibres and carbohydrates increased with ages. Significant variation （at p ≤ 0.5） was also observed in phenolic acids while minerals did not vary significantly. Results revealed that the optimum harvesting age for D. asper, D. strictus and B. tulda was on 10–14 days, 6–10 days and 10–16 days （after emergence from the ground） respectively. These results can be used to obtain quality bamboo shoots.

Prevalence and risk factors of asymptomatic hepatitis C virus infection in Egyptian children

AIM: To identify the prevalence, risk factors and manifestations of asymptomatic hepatitis C virus (HCV) infection in Egyptian children. METHODS: Children at the age of 1-9 years were screened for HCV antibodies and alanine aminotransferase (ALT) levels. Every child with elevated ALT and/or detectable HCV antibodies was tested for HCV RNA by RT-PCR and compared with two negative controls for risk factors and signs and symptoms of liver disease.RESULTS: We screened 1042 children, six of them had elevated ALT, negative HCV antibody and positive RNA, likely representing acute hepatitis C cases. Fifteen children were HCV seropositive, 5 of them were HCV RNA positive. Asymptomatic HCV infection was present in 2.02% (positive results for either HCV antibodies or HCV-RNA or both). Symptoms such as diarrhea, abdominal pain, history of fatigue and school absence because of illness and risk factors such as dental care were significantly more common among HCV positive cases than among controls. None of the HCV positive children was diagnosed as having signs of advanced liver disease upon clinical or ultrasonographic examination. CONCLUSION: Asymptomatic HCV infection is detectable in 2.02% Egyptian children.

Quantification by allometric equations of carbon sequestered by Tectona grandis in different agroforestry systems

Non destructive methods for quantification of carbon seques- tration in tropical trees are inadequately developed. We described a stan- dardized method for estimating carbon stock in teak （Tectona grandis Linn. F.）. We developed linear allometric equations using girth at breast height （GBH）, height and age to quantify above ground biomass （AGB）. We used AGB to estimate carbon stock for teak trees of different age groups （1.5, 3.5, 7.5, 13.5, 18.5 and 23.5 years）. The regression equation with GBH, y = 3.174x - 21.27, r2=0.898 （p 〈0.01）, was found precise and convenient due to the difficulty in determination of height and age in dense natural forests of teak. The equation was evaluated in teak agroforestry systems that included Triticum aestivum （wheat）, Cicer arietinum （gram）, Withania somnifera （ashwagandha）,

Effect of seed mass on emergence and seedling development in Pterocarpus marsupium Roxb.

We investigated the effect of seed mass on emergence, seedling survival and growth ofPterocarpus marsupium Roxb., a medium to large, commercially valuable and deciduous tree species. Among the three size classes viz. small （10-12 mm）, medium （13-15 mm） and large （16-17 mm）, the maximum proportion, of seed by number （54.12%） and dry weight （51.87%） was recorded, in the medium size seed class. Seed length and seed width were greatest in the large seed class （16.50 mm, 7.33 mm） followed by medium （13.50 mm, 5.60 mm） and small （11.37 ram, 3.66 mm）. Similarly, hundred seed weight （100 sw） varied from a maximum of 12.92 g in the large seed class to intermediate 10.95 g in the medium seed class and minimum of 7.02 g in the small seed class. The large seed size showed maximum emergence and shoot length over the medium and small seed class. After six months of growth, significant variations due to seed size were also observed for the growth and dry weight of P. marsupium seedlings. Seedling vigour, expressed in terms of height, collar diameter, number of leaves and dry biomass, was sig- nificantly affected by seed class. Seedlings that emerged from large seeds showed better growth and produced heavier seedlings as compared to medium and small seeds.

Detection of schistosomiasis antibodies in urine patients as a promising diagnostic maker

Objective:To determine secreted antischistosoma antibodies in urine and to discern the epidemiological situation of schistosomiasis in the agricultural field labourers’camps city in the Gezira State-central Sudan.Methods:Total of 66 urine and 66 serum paired samples were collected from those who confirmed parasitologically positive and negative with schistosomiasis from the two camps.Samples were tested using ELBA technique to measure and compare the immunoglobulin G(IgG) levels in serum and urine samples of schistosomiasis patients.Results: The overall prevalence of S.mansoni and S.haematobium was 53.8%and 15.4%,while the intensity were(2.04 GMEC) and(0.9 GMEC) respectively.The relative percentage of positive IgG individulas in urine was 92.40%where as 96.97%in serum.Statistically no significant difference between the IgG levels in serum and urine samples was observed.Conclusions:This study shows that the detection of secreted IgG antibodies in urine can substitute serum for diagnosis of schistosomiasis.

Using 16S rDNA Sequencing Technology to Preliminarily Analyze Intestinal Flora in Children with Mycoplasma pneumoniae Pneumonia

Objective We investigated changes in the intestinal flora of children with Mycoplasma pneumoniae pneumonia(MPP).Methods Between September 2019 and November 2019,stool samples from 14 children with MPP from The Fourth Hospital of Baotou city,Inner Mongolia Autonomous Region,were collected and divided into general treatment(AF)and probiotic(AFY)groups,according to the treatment of“combined Bifidobacterium,Lactobacillus,Enterococcus,and Bacillus cereus tablets live”.Highthroughput 16S rDNA sequencing was used to identify intestinal flora.Results Intestinal flora abundance and diversity in children with MPP were decreased.Both Shannon and Simpson indices were lower in the AF group when compared with healthy controls(P<.05).When compared with healthy controls,the proportion of Enterorhabdus was lower in the AF group,while the proportion of Lachnoclostridium was higher(P<0.05).The proportion of Bifidobacteria and Akkermansia was lower in the AFY group but Enterococcus,Lachnoclostridium,Roseburia,and Erysipelatoclostridium proportions were higher.The proportion of Escherichia coli-Shigella in the AFY group after treatment was decreased(P<0.05).Conclusions The intestinal flora of children with MPP is disturbed,manifested as decreased abundance and diversity,and decreased Bifidobacteria.Our probiotic mixture partly improved intestinal flora disorders.

An improvised in vitro vegetative propagation technique for Bambusa tulda： influence of season, sterilization and hormones

Season and concentration of sterilizing agents play a significant role for establishment of aseptic in vitro shoot cultures and sprouting of nodal explants from field growing culms of bamboo species. In the present investigation the nodal segment explants of Bambusa tulda Roxb collected in different seasons and treated with various concentrations of HgC12 showed significant variation in aseptic culture establishment and bud break. The rainy season （July-August） recorded with highest of 78% aseptic culture establishment whereas autumn recorded with lowest 46%. Summer and winter seasons emerged to be the best period, registering 〉 60% in vitro bud break. On the other hand, the autumn season had the lowest value for bud break, i.e. 42%. Among different doses of sterilizing agent tried, HgC12 0.1% found to be suitable for maximum aseptic culture establishment （66%） as well as bud break （59%）. However, among the interactions, summer season and the dose of 0.1% HgC12 exhibited maximum of 73% response for both aseptic culture establishment and bud break. MS medium （liquid） enriched with 5.0 μM BA ＋5.0 μM Kn [Kinetin （N6-Furfuryladenine）] with additional supplementation of 100 μM glutamine ＋ 0.1 μM IAA supported a maximum in vitro shoot multiplication of 4.75 fold. The proliferated shoots were successfully rooted on MS medium （liquid） supplemented 40 μM coumarin. The plantlets transferred to the polythene bags showed 98% survival.

Female mate choice and the potential for ornament evolution in túngara frogs Physalaemus pustulosus

The potential for ornament evolution in response to sexual selection rests on the interaction between the permissive- ness or selectivity of female preferences and the constraints on male development of signaling related traits. We investigate the former by determining how latent female preferences either exaggerate the magnitude of current traits （i.e. elaborations） or favor novel traits （i.e. innovations）. In tt^ngara frogs, females prefer complex mating calls （whine-chucks） to simple calls （whine only）. The whine is critical for mate recognition while the chuck further enhances the attractiveness of the call. Here we use a combina- tion of synthetic and natural stimuli to examine latent female preferences. Our results show that a diversity of stimuli, including conspecific and heterospecific calls as well as predator-produced and human-made sounds, increase the attractiveness of a call when added to a whine. These stimuli do not make simple calls more attractive than a whine-chuck, however. In rare cases we found stimuli that added to the whine decrease the attractiveness of the call. Overall, females show strong preferences for both elaborations and innovations of the chuck. We argue that the emancipation of these acoustic adornments from mate recognition allows such female permissiveness, and that male constraints on signal evolution are probably more important in explaining why males evolved their specific adornment. Experimentally probing latent female preferences for stimuli out of the species＇ range is a useful means to gain insights about the potential of female choice to influence signal evolution and thus the astounding diversity in male sexually-selected traits [Current Zoology 56 （3）： 343-357, 2010].

Micro RNAs and clinical implications in hepatocellular carcinoma

To assess the role of some circulating miRNAs (miR-23a, miR-203, miR338, miR-34, and miR-16) as tumor markers for diagnosis of hepatocellular carcinoma (HCC). METHODSOne hundred and seventy-one subjects were enrolled, 57 patients with HCC, 57 patients with liver cirrhosis (LC) and 57 healthy subjects as control group. Severity of liver disease was assessed by Child Pugh score. Tumor staging was done using Okuda staging system. Quantification of Micro RNA (miR-23a, miR-203, miR338, miR-34, and miR-16) was performed. RESULTSAll studied miRNA showed significant difference between HCC and cirrhotic patients in comparison to healthy control. miR-23a showed statistically significant difference between HCC and cirrhotic patients being higher in HCC group than cirrhotic. miR-23a is significantly higher in HCC patients with focal lesion size equal or more than 5 cm, patients with multiple focal lesions and Okuda stage III. At cutoff value ≥ 210, miR-23a showed accuracy 79.3% to diagnose HCC patients with sensitivity 89.47% and specificity about 64.91%. At cut off level ≥ 200 ng/mL, serum alpha fetoprotein had 73.68% sensitivity, 52.63% specificity, 43.75% PPV, 80% NPV for diagnosis of HCC. CONCLUSIONMicroRNA 23a can be used as a screening test for early detection of HCC. Also, it is related to larger size of tumour, late Okuda staging and multiple hepatic focal lesions, so it might be a prognostic biomarker.

Trees of Panama: A complete checklist with every geographic range

Background Central America is one of the most diverse floristic provinces in the world,but comprehensive plant lists for the region are incomplete and need frequent updating.Full geographic ranges of individual species are seldom known.Our detailed forest inventory plots of Panama thus lack a global geographic perspective.In order to provide one,we assembled a thoroughly vetted checklist of all tree species of Panama,along with an estimate of each one’s range size based on published specimen records.Results 1)Panama has 3043 tree species in 141 families and 752 genera;57.6%were≥10 m tall and 16.9%were 3-5 m tall.2)The widest ranges were>1.5×107 km2,covering the entire neotropics and reaching>30∘latitude;12.4%of the species had ranges exceeding 107 km2.The median range was 6.9×105 km2.3)At the other extreme,16.2%of the species had a range<20,000 km2,a criterion suggesting endangered status.4)Range size increased with a tree species’height and varied significantly among families.5)Tree census plots,where we mapped and measured all individuals,captured 27.5%of the tree species,but a biased selection relative to range size;only 4.5%of the species in plots had ranges<20,000 km2.Conclusions Our checklist of the trees of Panama,based on rigorous criteria aimed at matching plot censuses,is 20%larger than previous.By recording species’maximum heights,we allow comparisons with other regions based on matching definitions,and the range sizes provide a quantitative basis for assessing extinction risk.Our next goal is to merge population density from plot censuses to add rigor to predictions of extinction risk of poorly-studied tropical tree species.

Hepatitis C genotype 4: The past, present, and future

Hepatitis C virus(HCV) genotype(GT) 4 represents 12%-15%(15-18 million) of total global HCV infection. It is prevalent in Northern and Equatorial Africa and the Middle East, and is also present in some countries in Europe. GT-4(and subtype 4a in particular) dominates the HCV epidemic in Egypt. In underdeveloped countries, risk factors associated with HCV infection may be due to unsafe medical practices or other factors such as familial transmission, mother's HCV status, or illiteracy. HCV prevention and control programs should include health education, increased community awareness towards the disease, controlling infection distribution in healthcare centers, proper sterilization of medical and dental instruments, and ensuring safe supply of blood and blood-products. Response rates to a 48-wk combined pegylated-interferon(PEG-IFN) and ribavirin(RBV) treatment range from 40%-69%, and HCV-GT-4 has been considered better than GT-1 but worse than GT-2 and GT-3 in treatment with PEG-IFN/RBV. However, with the introduction of the HCV-GT-1 effective protease inhibitors boceprevir and telaprevir in 2011, HCV-GT-4 became the "most difficult(GT) to treat". Recently, the direct-acting antivirals(DAAs) with pan- genotypic activities simeprevir, sofosbuvir, and daclatasvir have been recommended in triple regimens with PEG-IFN/RBV for the treatment of HCV-GT-4. An IFN-free regimen will be available for treatment of all genotypes of HCV in the near future. To date, several DAAs have been developed and are currently being evaluated in various combinations in clinical trials. As new regimens and new agents are being approved by the Food and Drug Administration, we can expect the guidelines for HCV treatment to be changed. The availability of shorter, simpler, and more tolerable treatment regimens can reduce the morbidity and mortality associated with HCV infection. With such a large number of therapeutic agents available, we can end up with a range of choices that we can select from to treat patients.

Cystic pancreatic lesions,the endless dilemma

Cystic pancreatic lesions involve a wide variety of pathological entities that include neoplastic and non-neoplastic lesions.The proper diagnosis,differentiation,and staging of these cystic lesions are considered a crucial issue in planning further management.There are great challenges for their diagnostic models.In our time,new emerging methods for this diagnosis have been discovered.Endoscopic ultrasonography-guided fine-needle aspiration cytology with chemical and molecular analysis of cyst fluid and EUS-guided fine needlebased confocal laser endomicroscopy,through the needle microforceps biopsy,and single-operator cho-langioscopy/pancreatoscopy are promising methods that have been used in the diagnosis of cystic pancreatic lesions.Hereby we discuss the diagnosis of cystic pancreatic lesions and the benefits of various diagnostic models.

Metamorphic gradient modification in the Early Cretaceous Northern Andes subduction zone:A record from thermally overprinted high-pressure rocks

New field observations and petrological data from Early Cretaceous metamorphic rocks in the Central Cordillera of the Colombian Andes allowed the recognition of thermally overprinted high-pressure rocks derived from oceanic crust protoliths.The obtained metamorphic path suggests that the rocks evolved from blueschist to eclogite facies towards upper amphibolite to high-pressure granulite facies transitional conditions.Eclogite facies conditions,better recorded in mafic protoliths,are revealed by relic lawsonite and phengite,bleb-to worm-like diopside-albite symplectites,as well as garnet core composition.Upper amphibolite to high pressure granulite facies overprinting is supported by coarse-grained brown-colored Ti-rich amphibole,augite,and oligoclase recrystallization,as well as the record of partial melting leucosomes.Phase equilibria and pressure-temperature(P-T)path modeling suggest initial high-pressure metamorphic conditions M1 yielding 18.2-24.5 kbar and 465-580℃,followed by upper amphibolite to high pressure granulite facies overprinting stage M2 yielding 6.5-14.2 kbar and 580-720℃.Retrograde conditions M3 obtained through chlorite thermometry yield temperatures ranging around 286-400℃at pressures below 6.5-11 kbar.The obtained clockwise P-T path,the garnet zonation pattern revealing a decrease in X_(grs)/X_(prp)related to Mg#increment from core to rim,the presence of partial melting veins,as well as regional constraints,document the modification of the thermal structure of the active subduction zone in Northern Andes during the Early Cretaceous.Such increment of the metamorphic gradient within the subduction interface is associated with slab roll-back geodynamics where hot mantle inflow was triggered.This scenario is also argued by the reported trench-ward magmatic arc migration and multiple extensional basin formation during this period.The presented example constitutes the first report of Cretaceous roll-back-related metamorphism in the Caribbean and Andean realms,representing an additional piece of evidence for a margin-scale extensional event that modified the northwestern border of South America during the Early Cretaceous.

Mycoplasma pneumoniae Macrolide Resistance and MLVA Typing in Children in Beijing,China,in 2016:Is It Relevant?

Objective The aim of this study is to investigate the macrolide resistance rate and molecular type with multiple-locus variable-number tandem-repeat analysis(MLVA)of Mycoplasma pneumoniae of Beijing in 2016 in pediatric patients.Methods Real-time quantitative polymerase chain reaction(PCR)was used to identify M.pneumoniae,and MLVA was performed.The domain V of the 23 S rRNA was sequenced to detect macrolide-resistant point mutations.We also investigated the activities of antibiotics against M.pneumoniae isolates in vitro.Results The PCR detection rate of M.pneumoniae in children in Beijing was 40%,and the macrolide resistance rate was 66%.The A2063 G mutation in the 23 S rRNA V region is the dominant mutation(137/146,93.84%),whereas the A2064 G mutation is rare(9/146,6.16%).Seventy-three samples were typed successfully by MLVA typing,including 86.3%(63/73)were MLVA type 4-5-7-2,and 13.7%(10/73)were MLVA type 3-5-6-2.No other types were found.No strains were resistant to levofloxacin or tetracycline.Conclusion In 2016,a specific decrease in the macrolide resistance rate occurred in Beijing.The detection rate and macrolide resistance rate of outpatients are lower than those of inpatients.The A2063 G mutants M.pneumoniae have high levels of resistance to erythromycin and azithromycin.The primary MLVA type is 4-5-7-2,followed by 3-5-6-2.No other MLVA types were detected.No strains resistant to tetracycline or levofloxacin were found in vitro.