Isolation of viruses responsible for the demise of an Emiliania huxleyi bloom in the English Channel

This study used analytical flow cytometry (AFC) to monitor the abundance of phytoplankton, coccoliths, bacteria and viruses in a transect that crossed a high reflectance area in the western English Channel. The high reflectance area, observed by satellite, was caused by the demise of an Emiliania huxleyi bloom. Water samples were collected from depth profiles at four stations, one station outside and three stations inside the high reflectance area. Plots of transect data revealed very obvious differences between Station 1, outside, and Stations 2–4, inside the high reflectance area. Inside, concentrations of viruses were higher; E. huxleyi cells were lower; coccoliths were higher; bacteria were higher and virus:bacteria ratio was lower than at Station 1, outside the high reflectance area. This data can simply be interpreted as virus-induced lysis of E. huxleyi cells in the bloom causing large concentrations of coccoliths to detach, resulting in the high reflectance observed by satellite imagery. This interpretation was supported by the isolation of two viruses, EhV84 and EhV86, from the high reflectance area that lysed cultures of E. huxleyi host strain CCMP1516. Basic characterization revealed that they were lytic viruses approximately 170 nm–190 nm in diameter with an icosahedral symmetry. Taken together, transect and isolation data suggest that viruses were the major contributor to the demise of the E. huxleyi population in the high reflectance area. Close coupling between microalgae, bacteria and viruses contributed to a large organic carbon input. Consequent cycling influenced the succession of an E. huxleyi-dominated population to a more characteristic mixed summer phytoplankton community

Analisis Kepuasan Pelanggan Menggunakan Atribut Pelayanan Prima Dengan Mengintegrasikan Importance Performance Analysis (IPA) Dan Quality Function Deployment (Qfd) (Studi Kasus: PT. Sang Hyang Seri (Persero)-malang)

Kenaikan produksi padi tidak lepas dari semakin banyaknya penggunaan benih padi bersertifikat oleh petani. Kondisi ini berdampak pada perluasan pasar di Indonesia yang mengakibatkan persaingan industri perbenihan semakin tinggi serta setiap Perusahaan berpacu untuk mencari pelanggan termasuk PT.SHS. PT.SHS singkatan dari PT.Sang Hyang Seri adalah Perusahaan yang bergerak dibidang perbenihan. PT.SHS dituntut untuk memperbaiki mutu pelayanan.Pelayanan prima dianggap tepat sebagai USAha mencapai kepuasan pelanggan. Dalam penelitian ini digunakan integrasi Importance Performance Analysis (IPA) dan Quality Function Deployment (QFD). Dari hasil IPA dapat diketahui 11 atribut yang diprioritaskan pada kuadran satu ”Concentrate Here” yaitu kemampuan berkomunikasi,pegawai bertanggung awab atas pelayanannya,tersedia fasilitas penunjang, penampilan fisik pegawai rapi,sikap pegawai menghargai,sopan kepada pelanggan, pegawai mendengarkan,memahami kebutuhan pelanggan, pegawai bekerja sesuai prosedur,merespon keluhan yang disampaikan pelanggan,pegawai melayani kebutuhan pelanggan dan pegawai mencurahkan perhatian kepada pelanggan. Berdasarkan hasil analisis QFD, prioritas utama rekomendasi perbaikan yang dapat dilakukan PT.SHS yaitu pelaksanaan training pelayanan karyawan

Diffraction-limited imaging with ground-based optical telescopes

The construction of diffraction-limited images with ground-based optical telescopes by means of closure-phase observations is explored. The effect of redundant baselines on closure-phase observations is analyzed, and it is shown that for bright objects a nonredundant-mask approach is superior to the use of the full aperture. Observations of closure phase with a nonredundant mask on the 200 in. Hale Telescope are presented, and compared with the predictions of atmospheric seeing theory. It is demonstrated that fairly complex images can be constructed from closure-phase observations alone

Assessing South African Construction Worker’s Knowledge of Modern Technologies for Effective Material Management

Material management is a matter of concern for construction stakeholders in South Africa.  ICT is the way forward for all sectors upon which the economy thrives both in the national and international level. Incorporating modern technologies will lead to effective material management. However, the level of awareness of modern technologies among South African construction stakeholders needs to be assessed. The study adopted a quantitative approach where questionnaires were administered to professionals in the South African construction industry. Descriptive statistics tools were used to analyse the gathered data. Findings showed that construction stakeholders in South Africa are aware of modern technologies for effective management. The tools according to the level of awareness are Microsoft programs, barcoding, RFID, construction materials planning systems and materials handling equipment selection advisor. Also, the level of importance of these tools according to Stakeholders in South African Construction industry are Microsoft programmes, Barcoding, RFID, materials handling equipment selection advisor, construction materials exchange and construction materials planning system. Therefore, it is evident that there is still unyielding to recent technological move in the construction industry, which may be preventing the progressive growth. It is imperative to indulge modern technologies to counter this problem which in turn help effective material management

A Study of Nine High-Redshift Clusters of Galaxies: IV. Photometry and Sp ectra of Clusters 1324+3011 and 1604+4321

New photometric and spectroscopic observations of galaxies in the directions of three distant clusters are presented as part of our on-going high-redshift cluster survey. The clusters are CL1324+3011 at z = 0.76, CL1604+4304 at z = 0.90, and CL1604+4321 at z = 0.92. The observed x-ray luminosities in these clusters are at least a factor of 3 smaller than those observed in clusters with similar velocity dispersions at z <= 0.4. These clusters contain a significant population of elliptical-like galaxies, although these galaxies are not nearly as dominant as in massive clusters at z <= 0.5. We also find a large population of blue cluster members. Defining an active galaxy as one in which the rest equivalent width of [OII] is greater than 15 Angstroms, the fraction of active cluster galaxies, within the central 1.0 Mpc, is 45%. In the field population, we find that 65% of the galaxies with redshifts between z = 0.40 and z = 0.85 are active, while the fraction is 79% for field galaxies at z > 0.85. The star formation rate normalized by the rest AB B-band magnitude, SFRN, increases as the redshift increases at a given evolving luminosity. At a given redshift, however, SFRN decreases linearly with increasing luminosity indicating a remarkable insensitivity of the star formation rate to the intrinsic luminosity of the galaxy over the range -18 >= ABB >= -22. Cluster galaxies in the central 1 Mpc regions exhibit depressed star formation rates. We are able to measure significant evolution in the B-band luminosity function over the range 0.1 <= z <= 1. The characteristic luminosity increases by a factor of 3 with increasing redshift over this range.Comment: 64 pages, 18 figures, accepted for publication in the Astronomical Journal on May 25, 2001. Scheduled to appear in Sept 2001 issu

The H Beta Index as an Age Indicator of Old Stellar Systems: The Effects of Horizontal-Branch Stars

The strength of the H$\beta$ index has been computed for the integrated spectra of model globular clusters from the evolutionary population synthesis. These models take into account, for the first time, the detailed systematic variation of horizontal-branch (HB) morphology with age and metallicity. Our models show that the H$\beta$ index is significantly affected by the presence of blue HB stars. Because of the contribution from blue HB stars, the H$\beta$ does not monotonically decrease as metallicity increases at a given age. Instead, it reaches a maximum strength when the distribution of HB stars is centered around 9500 K, the temperature where the H$\beta$ index becomes strongest. Our models indicate that the strength of the H$\beta$ index increases as much as 0.75 {\AA} due to the presence of blue HB stars. The comparison of the recent Keck observations of the globular cluster system in the Milky Way Galaxy with those in giant elliptical galaxies, NGC 1399 and M87, shows a systematic shift in the H$\beta$ against metallicity plane. Our models suggest that this systematic difference is understood if the globular cluster systems in giant elliptical galaxies are several billion years older, in the mean, than the Galactic counterpart. Further observations of globular cluster systems in the external galaxies from the large ground-based telescopes and space UV facilities will enable to clarify whether this difference is indeed due to the age difference or other explanations are also possible.Comment: 21 pages, 8 figures, Accepted for publication in the Astronomical Journal, August 2000 issue, Postscript files are available at http://csaweb.yonsei.ac.kr/~hclee/Hbet

Themed project case study: Quadruple tanks control with PLCs^†

A themed project based on the control of a quadruple tank rig using PLCs has been successfully carried out as part of the MSc in Advanced Control and Systems Engineering at the University of Manchester. The themed project involves ten students who address a single multivariable control challenge under the supervision of two academics and four PhD students. As every student is required to write their own MSc dissertation, the key point is the possibility of using different control techniques to be implemented on different hardware platforms. </jats:p

PENGARUH EKSTRAK METANOL DAN EKSTRAK AIR DAUN BUNGA PUKUL EMPAT TERHADAP PERTUMBUHAN STREPTOCOCCUS PYOGENES

Streptococcus pyogenes merupakan penyebab tersering infeksi saluran pernafasan atas akut seperti tonsilofaringitis dan dapat menimbulkan komplikasi berat. Ekstrak herbal merupakan salah satu alternatif terapi di tengah risiko resistensi bakteri. Ekstrak metanol dan air bunga pukul empat lebih efektif daripada ekstrak etanol dan kloroform dalam menghambat bakteri gram positif dan negatif. Namun peran ekstrak bunga pukul empat dalam menghambat pertumbuhan Streptococcus pyogenes belum diketahui. Penelitian bertujuan untuk mengetahui pengaruh ekstrak metanol dan ekstrak air bunga pukul empat dalam menghambat pertumbuhan Streptococcus pyogenes. Rumusan masalah penelitian ialah apakah terdapat pengaruh ekstrak metanol dan ekstrak air daun bunga pukul empat terhadap pertumbuhan Streptococcus pyogenes. Penelitian bersifat eksperimen laboratorium pada enam kelompok uji yang terdiri dari kontrol negatif, kontrol positif serta empat kelompok konsentrasi dari masing-masing ekstrak terhadap pertumbuhan Streptococcus pyogenes. Pertumbuhan bakteri dinilai dengan mengukur diameter zona hambat. Data dianalisis menggunakan uji korelasi spearman. Skrining fiotkimia didapatkan hasil ekstrak metanol mengandung tanin, saponin, dan alkaloid. Ekstrak air mengandung tanin, alkaloid, dan flavonoid. Dari penelitian didapatkan hubungan antara besar ekstrak metanol daun bunga pukul empat dalam menghambat pertumbuhan Streptococcus pyogenes (P value 0,08). Ekstrak metanol dengan konsentrasi 12,5mg/ml memiliki zona hambat paling besar dibandingkan dengan konsentrasi lain. Data ekstrak air menunjukkan tidak adanya hubungan antara besar konsentrasi ekstrak dengan zona hambat pertumbuhan Streptococcus pyogenes (P value 0,253). Ekstrak metanol bunga pukul empat berpengaruh terhadap pertumbuhan Streptococcus pyogenes, sedangkan ekstrak air tidak berpengaruh. Dapat dilakukan penelitian lanjutan tentang efektivitas ekstrak metanol bunga pukul empat pada hewan coba