Predicting the potential distribution and habitat variables associated with pangolins in Nepal

Pangolins are highly-threatened due to illegal hunting and poaching, and by the loss, degradation, and fragmentation of their habitats. In Nepal, effective conservation actions for pangolins are scarce due to limited information on the distribution of pangolins in many areas of the country. To identify the nationwide distribution of pangolins in Nepal, and assess the environmental variables associated with their habitat, we conducted an extensive literature review to collate data from previous studies, canvassed information from key informant interviews and expert opinion, and conducted transect surveys and sign surveys. The occurrence of pangolins was recorded based on sightings and indirect signs (such as burrows, digs, tracks, and scats) along 115 belt transects of 500-m length with a fixed width of 50-m, and habitat parameters were surveyed using 347 quadrats of 10 m*10 m. Pangolin presence was confirmed from 61 out of 75 districts from the eastern to the far western parts of the country. The highest frequency of burrows (74%) was observed in the forested habitat constituting brown soil with medium texture (0.02–2 mm) within an elevation range of 500–1500 m above sea level. Logistic regression suggested that the occurrence of pangolin was highly influenced by ground cover and canopy cover of 50–75%, litter depth, and the distance to termite mounds and roads. We used 4136 occurrence GPS points of pangolin burrows that were compiled and collected from the literature review and field surveys in order to predict the potential habitat distribution of pangolin using maximum entropy algorithm (MaxEnt 3.4.1). The model predicted 15.2% (22,393 km2) of the total land of Nepal as potentially suitable habitat for pangolin, with 38.3% (8574 km2) of potential habitat in the eastern region, followed by 37.6% (8432 km2) in the central and 24.1% (5,387 km2) in the western regions. The results of this study present a national baseline for pangolin distribution and serve as an important document for developing and executing conservation actions and management plans for the long-term conservation of pangolins in Nepal

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data

Post Thawing Survival Rate Of Human Embryos In Slow Freezing Versus Vitrification: A Narrative Review

The study compared the outcomes of slow-freeze and vitrification methods for oocyte cryopreservation, analyzing five randomized controlled trials, two cohort studies, and eight systematic reviews and meta-analyses.Slow-freezeis performed at room temperature using a buffered medium supplemented with gentamicin and human serum albumin. It contains 1.5 M 1,2-propanediol and 0.1 M sucrose. On the other hand, vitrification has been the preferred method since 2007. During vitrification, embryos are initially incubated in a solution consisting of 7.5% ethylene glycol and 7.5% dimethyl sulfide, both in Ham's F-10 media. This solution is further supplemented with 20% Albuminal-5. After the initial recovery, the oocytes are aspirated and immersed in a vitrification solution composed of Ham's F-10 medium for a duration of 50 to 60 seconds. The cooling is done via liquid nitrogen, and embryos are stored for months. The survival rate of embryos is the percentage of those that survive after being warmed up. Live birth rates are calculated as the percentage of live births per transferred embryo and warmed embryo. Embryos are selected by biopsy at the zygote or blastocyst stage using non-invasive methods to optimize the success rates of in vitro fertilization. Vitrification has a greater success rate, better survival rates, and transferable embryos, it is chosen for oocyte cryopreservation. Better clinical pregnancy rates and implantation capacity have also been linked to it, notably for blastocysts from In Vitro Maturation programs. To assess effects on neonatal outcomes and congenital abnormalities, additional study is necessary

Overview of the DESI Legacy Imaging Surveys

The DESI Legacy Imaging Surveys (http://legacysurvey.org/) are a combination of three public projects (the Dark Energy Camera Legacy Survey, the Beijing–Arizona Sky Survey, and the Mayall z-band Legacy Survey) that will jointly image ≈14,000 deg2 of the extragalactic sky visible from the northern hemisphere in three optical bands (g, r, and z) using telescopes at the Kitt Peak National Observatory and the Cerro Tololo Inter-American Observatory. The combined survey footprint is split into two contiguous areas by the Galactic plane. The optical imaging is conducted using a unique strategy of dynamically adjusting the exposure times and pointing selection during observing that results in a survey of nearly uniform depth. In addition to calibrated images, the project is delivering a catalog, constructed by using a probabilistic inference-based approach to estimate source shapes and brightnesses. The catalog includes photometry from the grz optical bands and from four mid-infrared bands (at 3.4, 4.6, 12, and 22 μm) observed by the Wide-field Infrared Survey Explorer satellite during its full operational lifetime. The project plans two public data releases each year. All the software used to generate the catalogs is also released with the data. This paper provides an overview of the Legacy Surveys project

The DESI experiment part I: science, targeting, and survey design

DESI (Dark Energy Spectroscopic Instrument) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations (BAO) and the growth of structure through redshift-space distortions with a wide-area galaxy and quasar redshift survey. To trace the underlying dark matter distribution, spectroscopic targets will be selected in four classes from imaging data. We will measure luminous red galaxies up to $z=1.0$. To probe the Universe out to even higher redshift, DESI will target bright [O II] emission line galaxies up to $z=1.7$. Quasars will be targeted both as direct tracers of the underlying dark matter distribution and, at higher redshifts ($2.1 < z < 3.5$), for the Ly-$\alpha$ forest absorption features in their spectra, which will be used to trace the distribution of neutral hydrogen. When moonlight prevents efficient observations of the faint targets of the baseline survey, DESI will conduct a magnitude-limited Bright Galaxy Survey comprising approximately 10 million galaxies with a median $z\approx 0.2$. In total, more than 30 million galaxy and quasar redshifts will be obtained to measure the BAO feature and determine the matter power spectrum, including redshift space distortions

The DESI Experiment Part II: Instrument Design

DESI (Dark Energy Spectropic Instrument) is a Stage IV ground-based dark energy experiment that will study baryon acoustic oscillations and the growth of structure through redshift-space distortions with a wide-area galaxy and quasar redshift survey. The DESI instrument is a robotically-actuated, fiber-fed spectrograph capable of taking up to 5,000 simultaneous spectra over a wavelength range from 360 nm to 980 nm. The fibers feed ten three-arm spectrographs with resolution $R= \lambda/\Delta\lambda$ between 2000 and 5500, depending on wavelength. The DESI instrument will be used to conduct a five-year survey designed to cover 14,000 deg$^2$. This powerful instrument will be installed at prime focus on the 4-m Mayall telescope in Kitt Peak, Arizona, along with a new optical corrector, which will provide a three-degree diameter field of view. The DESI collaboration will also deliver a spectroscopic pipeline and data management system to reduce and archive all data for eventual public use