Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta

Ultrasonographic evaluation of two protocols of synchronization of estrus in cows

The loss of an estrous cycle is critical in any production system. Especially in artificial insemination programs in which the detection of estrus depends on the human factor. The detection of estrus, has been one of the limitations for the massive use of artificial insemination. Therefore, the application of estrus and ovulation synchronization methods is very important in reproductive management in cattle. The objective was to evaluate by ultrasonography two estrus synchronization protocols in beef cows (Aberdeen angus). The research was carried out at the Research and Production Center (CIP) Chuquibambilla of the National University of the Altiplano. The experiment was performed with 30 cows that were divided into two groups of 15 for the first protocol (T1-Ovsynch) and 15 animals for the second protocol (T2-CIDR-synch). The ovarian function for T1 was 50% for both the right and left ovary, while for T2 it was 75 and 25% for right and left ovary, respectively; Presence of corpus luteum (CL) was 75% of cows for T1 and 60% of cows for T2, the follicle growth rate was for T1 of 0.5 ± 0.87 mm and for T2 of 1.2 ± 0.74 mm; The maximum diameter of the ovarian follicle for TI was 8.09 ± 3.23 mm and for T2 of 10.2 ± 3.16 mm and the pregnancy rate for T1 was 33.3% and for T2 of 66.7%. In conclusion, ultrasonographic evaluation is a useful tool for evaluating estrus synchronization protocols. Real-time observation of the synchrony of the emergence of a new follicular wave (at the beginning of the treatments) and ovulation in both protocols, resulting in a higher pregnancy rate

Sensitive detection of mitochondrial DNA variants for analysis of mitochondrial DNA-enriched extracts from frozen tumor tissue

Abstract Large variation exists in mitochondrial DNA (mtDNA) not only between but also within individuals. Also in human cancer, tumor-specific mtDNA variation exists. In this work, we describe the comparison of four methods to extract mtDNA as pure as possible from frozen tumor tissue. Also, three state-of-the-art methods for sensitive detection of mtDNA variants were evaluated. The main aim was to develop a procedure to detect low-frequent single-nucleotide mtDNA-specific variants in frozen tumor tissue. We show that of the methods evaluated, DNA extracted from cytosol fractions following exonuclease treatment results in highest mtDNA yield and purity from frozen tumor tissue (270-fold mtDNA enrichment). Next, we demonstrate the sensitivity of detection of low-frequent single-nucleotide mtDNA variants (≤1% allele frequency) in breast cancer cell lines MDA-MB-231 and MCF-7 by single-molecule real-time (SMRT) sequencing, UltraSEEK chemistry based mass spectrometry, and digital PCR. We also show de novo detection and allelic phasing of variants by SMRT sequencing. We conclude that our sensitive procedure to detect low-frequent single-nucleotide mtDNA variants from frozen tumor tissue is based on extraction of DNA from cytosol fractions followed by exonuclease treatment to obtain high mtDNA purity, and subsequent SMRT sequencing for (de novo) detection and allelic phasing of variants