32 research outputs found
The Seventeenth Data Release of the Sloan Digital Sky Surveys: Complete Release of MaNGA, MaStar and APOGEE-2 Data
This paper documents the seventeenth data release (DR17) from the Sloan Digital Sky Surveys; the fifth and final release from the fourth phase (SDSS-IV). DR17 contains the complete release of the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey, which reached its goal of surveying over 10,000 nearby galaxies. The complete release of the MaNGA Stellar Library (MaStar) accompanies this data, providing observations of almost 30,000 stars through the MaNGA instrument during bright time. DR17 also contains the complete release of the Apache Point Observatory Galactic Evolution Experiment 2 (APOGEE-2) survey which publicly releases infra-red spectra of over 650,000 stars. The main sample from the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), as well as the sub-survey Time Domain Spectroscopic Survey (TDSS) data were fully released in DR16. New single-fiber optical spectroscopy released in DR17 is from the SPectroscipic IDentification of ERosita Survey (SPIDERS) sub-survey and the eBOSS-RM program. Along with the primary data sets, DR17 includes 25 new or updated Value Added Catalogs (VACs). This paper concludes the release of SDSS-IV survey data. SDSS continues into its fifth phase with observations already underway for the Milky Way Mapper (MWM), Local Volume Mapper (LVM) and Black Hole Mapper (BHM) surveys
The Use of Project Time Management Processes and the Schedule Performance of Construction Projects in Mexico
Delays have been frequently reported as the cause of several conflicts that affect the different parties involved in construction projects. Project Time Management (PTM) includes a number of planning and controlling processes that are recommended for complying with requirements related to project time. The study reported in this paper aimed at assessing the use of PTM processes and its relation with project schedule performance (i.e., timely completion). Seven PTM processes and seventy-seven tasks associated with them were identified from the literature that is globally relevant to project management. The study included the assessment of fourteen school construction projects executed by a public agency in the Yucatan Peninsula, Mexico. These projects were monitored during the construction phase in order to measure two different variables: the use of processes related to PTM (i.e., schedule planning and controlling processes) and the project schedule performance. For each of these projects a Use Index was obtained for assessing the first variable, while the Schedule Performance Index and the Schedule Variance were computed to assess the second one. The results demonstrated there is statistical dependence between these two variables. Most of the projects that attained timely completion also made a greater use of the PTM processes
Comparative kinetic characterization of the activity of glycosylated and non-glycosylated trypsin-like serine protease isolated from adults of Rhyzopertha dominica (Coleoptera: Bostrichidae) reared on the grain of three different cultivars of wheat
Rhyzopertha dominica is a pest that uses trypsin-like serine protease enzymes to hydrolyse the proteins in the cereal grains on which it feeds. The present study reveals for the first time that that there are both glycosylated and non-glycosylated serine proteases. The progeny of R. dominica reared on the grain three varieties of wheat were used to fractionate their trypsin-like serine proteases using Concanavalin A affinity chromatography. The albumin fractions from the wheat cultivars used in this study were subjected to size exclusion chromatography to fractionate the albumin inhibitors that are highly specific for the serine protease activity of R. dominica. Kinetic and thermodynamic assays were used to differentiate both types of enzymes. In general, the catalytic efficiency values Vmax/Km for glycosylated proteases were higher, indicating that glycosylation increases the affinity for the substrate. Inhibition assays using wheat albumins revealed that the glycosylated enzymes had higher Ki values, indicating a low affinity for the inhibitors than the non-glycosylated enzymes. Thermodynamic analysis indicates that glycosylation increases the activation energy Ea improving the serine proteases' catalysis. Thus it is likely that R. dominica uses glycosylated proteases in order to optimize the hydrolysis of cereal proteins and nullify the action of wheat grain protease inhibitors and increase its chances of survival
A Open One-Step RT-qPCR for SARS-CoV-2 detection
<p>Sequences of the plasmids needed to purify the required enzymes for a standardized One-Step open RT-qPCR protocol to detect SARS-CoV-2 RNA in clinical samples. Supplementary Information</p><p>Filetype GB</p>
Oribatid mites and springtails from a coffee plantation in Sierra Sur, Oaxaca, Mexico Ácaros oribatídeos e colêmbolos de uma plantação de café em Sierra Sur, Oaxaca, México
The objective of this work was to compare the oribatid mite and springtail communities in three plots with different soil use - Coffee (CP), secondary vegetation or fallow fields (acahual, A) and a cloud mountain forest (CMF) - within a coffee plantation located in Santa Maria Huatulco, Oaxaca State, Mexico. In each plot 20 samples (10 of soil, 10 of litter) were taken and processed in Berlese funnels. The extracted fauna was preserved in 70% ethanol. A total of 3,031 oribatid mites belonging to 33 species, and 1,177 specimens of springtails belonging to 43 species, were collected. The number of species recorded was: 27 at CP (14 oribatids; 13 springtails), 44 at A (19 oribatids; 25 springtails) and 62 at CMF (32 for each group). A total of 26 oribatid and 27 springtail species was found in the soil, and 25 oribatid and 32 springtail species were found in the litter. The most abundant species were the oribatids Rostroztes foveolatus (Haplozetidae), Tectocepheus sp. (Tecocepheidae), Karenella sp. (Oppidae), Atropacarus (Hoplophorella) cf. fonseciai (Phthiracaridae), Epilohmannia pallida americana (Epilohmannidae), and the springtails Ceratophysella cf. gibbosa (Hypogastruridae), Mesaphorura sp. (Tullbergidae) and Proisotoma cf. minuta (Isotomidae). Fourteen families and 18 species of Oribatida species and 5 families and 34 species of Collembola were recorded for the first time for the State.<br>O objetivo deste trabalho foi comparar as comunidades de ácaros oribatídeos e de colêmbolos em três parcelas com uso diferente do solo - plantação de café (CP), a vegetação secundária ou pousio (acahual, A) e a floresta nublada de montanha (CMF) - em uma plantação de café situada na municipalidade de Santa María Huatulco, estado de Oaxaca, México. Vinte amostras foram tomadas em cada lote (dez do solo, dez de serapilheira) e processadas em funis de Berlese. A fauna extraída foi preservada em álcool 70%. Um total de 3.031 ácaros oribatídeos pertencentes a 33 espécies e de 1.177 espécimes de colêmbolos de 43 espécies foram coletados. Os números de espécies encontradas foram: 27 no CP (14 oribatídeos e 13 colêmbolos); 44 em A (19 oribatídeos e 25 colêmbolos); e 62 no CMF (32 para cada grupo). Foram encontradas 26 espécies de ácaros oribatídeos e 27 de colêmbolos no solo e 25 espécies de ácaros e 32 de colêmbolos na serapilheira. As espécies mais abundantes foram os oribatídeos Rostroztes foveolatus (Haplozetidae), Tectocepheus sp. (Tecocepheidae), Karenella sp. (Oppidae), Atropacarus (Hoplophorella) cf. fonseciai (Phthiracaridae), Epilohmannia pallida americana (Epilohmannidae); e os colêmbolos Ceratophysella cf. gibbosa (Hypogastruridae), Mesaphorura sp. (Tullbergidae) and Proisotoma cf. minuta (Isotomidae). Foram registradas 18 espécies e 14 famílias de Oribatida e 34 espécies e 5 famílias de Collembola como novos registros para o estado
CDC SARS-CoV-2 N1 and N2 probe-based One-Step RT-qPCR assays performed with synthetic RNA using homebrew M-MLV RT and Taq DNA pol.
(A-B) Representative amplification curves using N1 and N2 CDC-approved double-quenched probes. Each curve represents a specific dilution of SARS-CoV-2 synthetic N RNA used as template: 1.4 x 107 copies approximately (red line), 1.4 x 106 (yellow line), 1.4 x 105 (green line), 1.4 x 104 (light blue line), 1.4 x 103 (blue line), 1.4 x 102 (purple line), 1.4 x 101 (light brown line) and no template control (NTC, gray line). Amplification curves for synthetic N RNA from MERS-CoV (black dashed line) and SARS-CoV-1 (orange dashed line) are also indicated. Characteristic Cq values are indicated on the upper left side of each panel. N.d.: non-detected (no Cq reported).</p
Probe-based Open One-Step RT-qPCR reaction mix (M-MLV RT and Taq DNA pol) provides comparable results to commercial kits in SARS-CoV-2 clinical samples.
Scatterplot of the Cq values of positive (blue circles) and negative (red squares) samples obtained by the commercial and open RT-qPCR reaction master mixes using the N1 and N2 primer/probe sets (A and B, respectively). The numbers displayed in each sample match those displayed in Table 3 (# Sample). If a Cq value was not detected in the sample, it appears in the ND area of the graph depending on whether this occurred in the commercial kit (green rectangle), the open probe-based kit (gray rectangle), or both (intersections between the rectangles). For each combination of primers and probes, the linear trend of the positive samples is shown (blue dotted line) along with the corresponding value of r2. ND: non-detected.</p
S1 Raw images -
The COVID-19 pandemic has resulted in millions of deaths globally, and while several diagnostic systems were proposed, real-time reverse transcription polymerase chain reaction (RT-PCR) remains the gold standard. However, diagnostic reagents, including enzymes used in RT-PCR, are subject to centralized production models and intellectual property restrictions, which present a challenge for less developed countries. With the aim of generating a standardized One-Step open RT-qPCR protocol to detect SARS-CoV-2 RNA in clinical samples, we purified and tested recombinant enzymes and a non-proprietary buffer. The protocol utilized M-MLV RT and Taq DNA pol enzymes to perform a Taqman probe-based assay. Synthetic RNA samples were used to validate the One-Step RT-qPCR components, demonstrating sensitivity comparable to a commercial kit routinely employed in clinical settings for patient diagnosis. Further evaluation on 40 clinical samples (20 positive and 20 negative) confirmed its comparable diagnostic accuracy. This study represents a proof of concept for an open approach to developing diagnostic kits for viral infections and diseases, which could provide a cost-effective and accessible solution for less developed countries.</div
Dye-based One-Step RT-qPCR cycling conditions.
The COVID-19 pandemic has resulted in millions of deaths globally, and while several diagnostic systems were proposed, real-time reverse transcription polymerase chain reaction (RT-PCR) remains the gold standard. However, diagnostic reagents, including enzymes used in RT-PCR, are subject to centralized production models and intellectual property restrictions, which present a challenge for less developed countries. With the aim of generating a standardized One-Step open RT-qPCR protocol to detect SARS-CoV-2 RNA in clinical samples, we purified and tested recombinant enzymes and a non-proprietary buffer. The protocol utilized M-MLV RT and Taq DNA pol enzymes to perform a Taqman probe-based assay. Synthetic RNA samples were used to validate the One-Step RT-qPCR components, demonstrating sensitivity comparable to a commercial kit routinely employed in clinical settings for patient diagnosis. Further evaluation on 40 clinical samples (20 positive and 20 negative) confirmed its comparable diagnostic accuracy. This study represents a proof of concept for an open approach to developing diagnostic kits for viral infections and diseases, which could provide a cost-effective and accessible solution for less developed countries.</div
One-Step RT-qPCR reaction mix using M-MLV RT and Taq DNA pol.
One-Step RT-qPCR reaction mix using M-MLV RT and Taq DNA pol.</p