Isolation and identification of two marine-derived Streptomyces from marine mud of coast and offshore Zhuhai, and bioactive potential for plant pathogenic fungi

Two different actinomycete strains (XAS585 and XAS588), producing antifungal substances, were isolated from the marine mud of coast and offshore Zhuhai city, Guangdong province, China. On the basis of micro-morphology, physiological and chemotaxonomic characterization and phylogenetic similarity of 16S rDNA gene sequences, the strains XAS585 and XAS588 were identified as Streptomyces roseobiolascens XAS585 and Streptomyces roseofulvus XAS588, respectively. Antifungal profiles of the ethyl acetate extracts of the two strains fermented broth (FBE) were evaluated against the test phytopathogenic fungi; the results showed that the FBE of S. roseobiolascens XAS585 exhibited strong antifungal activity against mycelia growth of all test fungi at 150 μg/ml, while the FBE of S. roseobiolascens XAS588 also exhibited strong antifungal activity, except Sclerotinia scleroitiorum, Valsa mali and Cercospora sorghi at 150 μg/ml. In addition, the FBE of both strains at 100 g/ml showed inhibitory effect against the condina germination of Alternaria alternate, Exserlhilum turcicum and Bipolaris sorokiniana. This study showed that the two marinederived Streptomyces may provide potent sources for antifungal metabolites.Key words: Actinomycete, phytopathogenic fungi, antimicrobial activity, marine mud, Streptomyces roseobiolascens XAS585, Streptomyces roseofulvus XAS588

Likelihood Analysis for the Ratio of Means of Two Independent Log-Normal Distributions

Existing methods for comparing the means of two independent skewed log-normal distributions do not perform well in a range of small-sample settings such as a small-sample bioavailability study. In this article, we propose two likelihood-based approaches—the signed log-likelihood ratio statistic and modified signed log-likelihood ratio statistic—for inference about the ratio of means of two independent log-normal distributions. More specifically, we focus on obtaining p -values for testing the equality of means and also constructing confidence intervals for the ratio of means. The performance of the proposed methods is assessed through simulation studies that show that the modified signed log-likelihood ratio statistic is nearly an exact approach even for very small samples. The methods are also applied to two real-life examples.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/65218/1/j.0006-341X.2002.00463.x.pd

Synthetic white balancing for intra-operative hyperspectral imaging

Hyperspectral imaging shows promise for surgical applications to non-invasively provide spatially-resolved, spectral information. For calibration purposes, a white reference image of a highly-reflective Lambertian surface should be obtained under the same imaging conditions. Standard white references are not sterilizable, and so are unsuitable for surgical environments. We demonstrate the necessity for in situ white references and address this by proposing a novel, sterile, synthetic reference construction algorithm. The use of references obtained at different distances and lighting conditions to the subject were examined. Spectral and color reconstructions were compared with standard measurements qualitatively and quantitatively, using $\Delta E$ and normalised RMSE respectively. The algorithm forms a composite image from a video of a standard sterile ruler, whose imperfect reflectivity is compensated for. The reference is modelled as the product of independent spatial and spectral components, and a scalar factor accounting for gain, exposure, and light intensity. Evaluation of synthetic references against ideal but non-sterile references is performed using the same metrics alongside pixel-by-pixel errors. Finally, intraoperative integration is assessed though cadaveric experiments. Improper white balancing leads to increases in all quantitative and qualitative errors. Synthetic references achieve median pixel-by-pixel errors lower than 6.5% and produce similar reconstructions and errors to an ideal reference. The algorithm integrated well into surgical workflow, achieving median pixel-by-pixel errors of 4.77%, while maintaining good spectral and color reconstruction.Comment: 22 pages, 10 figure

LAMOST Observations in 15 \textit{K}2 Campaigns: I. Low resolution spectra from LAMOST DR6

The LAMOST-\textit{K}2 (L\textit{K}2) project, initiated in 2015, aims to collect low-resolution spectra of targets in the \textit{K}2 campaigns, similar to LAMOST-\textit{Kepler} project. By the end of 2018, a total of 126 L\textit{K}2 plates had been observed by LAMOST. After cross-matching the catalog of the LAMOST data release 6 (DR6) with that of the \textit{K}2 approved targets, we found 160,619 usable spectra of 84,012 objects, most of which had been observed more than once. The effective temperature, surface gravity, metallicity, and radial velocity from 129,974 spectra for 70,895 objects are derived through the LAMOST Stellar Parameter Pipeline (LASP). The internal uncertainties were estimated to be 81 K, 0.15 dex, 0.09 dex and 5 kms$^{-1}$, respectively, when derived from a spectrum with a signal-to-noise ratio in the $g$ band (SNR$_g$) of 10. These estimates are based on results for targets with multiple visits. The external accuracies were assessed by comparing the parameters of targets in common with the APOGEE and GAIA surveys, for which we generally found linear relationships. A final calibration is provided, combining external and internal uncertainties for giants and dwarfs, separately. We foresee that these spectroscopic data will be used widely in different research fields, especially in combination with \textit{K}2 photometry.Comment: 31 pages, 9 figures, 6 tables, accepted by ApJ

Multi-year succession of cyanobacteria blooms in a highland reservoir with changing nutrient status, Guizhou Province, China

Over the last 22 years significant phytoplankton changes in Hongfeng lake reservoir have been observed with multiple years of harmful cyanobacteria blooms (cHABs). Fish farming and other anthropogenic activities from 1994-2001 triggered the harmful blooms. Nine years after the cessation of aquaculture, a conversion from problematic species (Microcystis spp, Aphanizomenon flos-aquae) to the less problematic species P. limnetica and other associated non-cyanobacteria taxa was recorded. Through this period of change, trophic factors (bottom-up) were re-examined, and correlations between cHABs and selected environmental variables were observed. Higher temperatures, nutrients (TN, TP) and available light significantly favored the development of Microcystis spp blooms. With declining nutrient loads, and a decline in TP relative to TN there was a competitive shift from Microcystis summer blooms to the growth of Pseudanabaena limnetica and other non-cyanobacteria. Pseudanabaena limnetica was favored over Microcystis spp when temperatures were <20°C and TP was <0.03 mg L-1. The apparent species succession to P. limnetica was enhanced by a competitive advantage under varied light conditions. Multiple environmental and biotic conditions (not always nutrients) were driving cHABs. Although only a selected number of environmental variables were examined, the CCA analysis supports observations that temperature and nutrients were associated with the species shift. The replacement of cHABs with the growth of less toxic cyanobacteria like P. limnetica, and other algae creates an interesting scenario (new community condition) for the removal of problematic taxa in reservoir systems. Diverting or controlling blooms will have direct implications on water quality and economic remediation initiatives in reservoir and lake management

Phase II of the LAMOST-Kepler/K2 survey. I. Time series of medium-resolution spectroscopic observations

Phase \RNum{2} of the LAMOST-{\sl Kepler/K}2 survey (LK-MRS), initiated in 2018, aims at collecting medium-resolution spectra ($R\sim7,500$; hereafter MRS) for more than $50,000$ stars with multiple visits ($\sim60$ epochs) over a period of 5 years (2018 September to 2023 June). We selected 20 footprints distributed across the {\sl Kepler} field and six {\sl K}2 campaigns, with each plate containing a number of stars ranging from $\sim2,000$ to $\sim 3,000$. During the first year of observations, the LK-MRS has already collected $\sim280,000$ and $\sim369,000$ high-quality spectra in the blue and red wavelength range, respectively. The atmospheric parameters and radial velocities for $\sim259,000$ spectra of $21,053$ targets were successfully calculated by the LASP pipeline. The internal uncertainties for the effective temperature, surface gravity, metallicity, and radial velocity are found to be $100$\,K, $0.15$\,dex, $0.09$\,dex, and $1.00$\,km\,s$^{-1}$, respectively. We found $14,997$, $20,091$, and $1,514$ stars in common with the targets from the LAMOST low-resolution survey (LRS), GAIA and APOGEE, respectively, corresponding to a fraction of $\sim70\%$, $\sim95\%$ and $\sim7.2\%$. In general, the parameters derived from LK-MRS spectra are consistent with those obtained from the LRS and APOGEE spectra, but the scatter increases as the surface gravity decreases when comparing with the measurements from APOGEE. A large discrepancy is found with the GAIA values of the effective temperature. The comparisons of radial velocities of LK-MRS to GAIA and LK-MRS to APOGEE nearly follow an Gaussian distribution with a mean $\mu\sim1.10$ and $0.73$\,km\,s$^{-1}$, respectively.Comment: 24 pages, 15 figures, 4 tables, ApJS, accepte

Toksični učinci olova u profesionalno izložene indijske obitelji

This article describes an entire family manufacturing lead acid batteries who all suffered from lead poisoning. The family of five lived in a house, part of which had been used for various stages of battery production for 14 years. Open space was used for drying batteries. They all drank water from a well located on the premises. Evaluation of biomarkers of lead exposure and/or effect revealed alarming blood lead levels [(3.92±0.94) µmol L-1], 50 % reduction in the activity of δ-aminolevulinic acid dehydratase [(24.67±5.12) U L-1] and an increase in zinc protoporphyrin [(1228±480) µg L-1]. Liver function tests showed an increase in serum alkaline phosphatase [(170.41±41.82) U L-1]. All other liver function test parameters were normal. Renal function tests showed an increase in serum uric acid [(515.81±86.29) µmol L-1] while urea and creatinine were normal. Serum calcium was low [(1.90±0.42) mmol L-1 in women and (2.09±0.12) mmol L-1 in men], while blood pressure was high in the head of the family and his wife and normal in children. Lead concentration in well water was estimated to 180 µg L-1. The family was referred to the National Referral Centre for Lead Poisoning in India, were they were received treatment and were informed about the hazards of lead poisoning. A follow up three months later showed a slight decrease in blood lead levels and a significant increase in haemoglobin. These findings can be attributed to behavioural changes adopted by the family, even though they continued producing lead batteries.Olovo je sveprisutni metal s mnogo namjena, a čovječanstvo ga rabi već više od 6000 godina. Danas je olovo među najrasprostranjenijim toksinima u okolišu, a drugi je na popisu toksičnih metala, odmah iza arsena. Mnogi još nisu svjesni njegova toksičnoga djelovanja te se i dalje izlažu olovu. Ovdje je opisana obitelj koja proizvodi olovne akumulatore i koja je pretrpjela trovanje olovom zahvaljujući svojoj neobaviještenosti. Ova peteročlana obitelj živjela je u jednome kućanstvu čiji je dio namijenjen različitim fazama proizvodnje akumulatora već 14 godina. Akumulatori su se sušili na otvorenome. Na imanju je bio i bunar s pitkom vodom. Mjerenja biopokazatelja izloženosti olovu i njegova djelovanja u svih pet članova obitelji dovela su do alarmantnoga saznanja o razinama olova u krvi [(3,92±0,94) µmol L-1], 50 %-tnom padu aktivnosti dehidrataze δ-aminolevulinske kiseline [(24,67±5,12) U L-1] te povišenom cinkovu protoporfirinu [(1228±480) µg L-1]. Jetrene probe otkrile su povišene razine alkalne fosfataze u serumu [(170,41±41,82) U L-1]. Ostali su parametri jetrene funkcije bili normalni. Testovi funkcije bubrega otkrili su povišene razine mokraćne kiseline u serumu [(515,81±86,29) µmol L-1], dok su razine ureje i kreatinina bile normalne. Također je zabilježen pad razina kalcija u serumu [(1,90±0,42) mmol L-1 u žena te (2,09±0,12) mmol L-1 u muškaraca]. Povišeni krvni tlak zamijećen je u glave obitelji i njegove supruge, dok je u djece bio normalan. Koncentracija olova u bunarskoj vodi bila je izrazito visoka, prema procjeni 180 µg L-1. Obitelj je upućena u indijski Državni referalni centar za otrovanje olovom (National Referral Centre for Lead Poisoning) gdje je primila lijekove i bila upoznata s činjenicama vezanim uz otrovanje olovom. Tromjesečno je praćenje pokazalo blagi pad razina olova u krvi te značajan porast hemoglobina. Ovi se nalazi mogu pripisati promjenama u ponašanju obitelji, bez obzira na to što je nastavila proizvoditi akumulatore

Constructing majority-rule supertrees

<p>Abstract</p> <p>Background</p> <p>Supertree methods combine the phylogenetic information from multiple partially-overlapping trees into a larger phylogenetic tree called a supertree. Several supertree construction methods have been proposed to date, but most of these are not designed with any specific properties in mind. Recently, Cotton and Wilkinson proposed extensions of the majority-rule consensus tree method to the supertree setting that inherit many of the appealing properties of the former.</p> <p>Results</p> <p>We study a variant of one of Cotton and Wilkinson's methods, called majority-rule (+) supertrees. After proving that a key underlying problem for constructing majority-rule (+) supertrees is NP-hard, we develop a polynomial-size exact integer linear programming formulation of the problem. We then present a data reduction heuristic that identifies smaller subproblems that can be solved independently. While this technique is not guaranteed to produce optimal solutions, it can achieve substantial problem-size reduction. Finally, we report on a computational study of our approach on various real data sets, including the 121-taxon, 7-tree Seabirds data set of Kennedy and Page.</p> <p>Conclusions</p> <p>The results indicate that our exact method is computationally feasible for moderately large inputs. For larger inputs, our data reduction heuristic makes it feasible to tackle problems that are well beyond the range of the basic integer programming approach. Comparisons between the results obtained by our heuristic and exact solutions indicate that the heuristic produces good answers. Our results also suggest that the majority-rule (+) approach, in both its basic form and with data reduction, yields biologically meaningful phylogenies.</p