Dark-siren Cosmology with Decihertz Gravitational-wave Detectors

Gravitational waves (GWs) originated from mergers of stellar-mass binary black holes (SBBHs) are considered as dark sirens in cosmology since they usually do not have electromagnetic counterparts. In order to study cosmos with these events, we not only need the luminosity distances extracted from GW signals, but also require the redshift information of sources via, say, matching GW sky localization with galaxy catalogs. Based on such a methodology, we explore how well decihertz GW detectors, DO-Optimal and DECIGO, can constrain cosmological parameters. Using Monte-Carlo simulated dark sirens, we find that DO-Optimal can constrain the Hubble parameter to ${\sigma_{H_0}} / {H_0}\, \lesssim 0.2\%$ when estimating $H_0$ alone, while DECIGO performs better by a factor of 6 with ${\sigma_{H_0}} / {H_0}\lesssim 0.03\%$. Such a good precision of $H_0$ will shed light on the $H_0$ tension. For multiple-parameter estimation, DECIGO can still reach a level of ${\sigma_{H_0}} / {H_0} \lesssim 5\%$. The reason why decihertz detectors perform well is explained by their large numbers of SBBH GW events with good distance and angular resolution.Comment: 11 pages, 7 figures, comments welcom

In-Depth Transcriptome Analysis of the Red Swamp Crayfish <i>Procambarus clarkii</i>

<div><p>The red swamp crayfish <i>Procambarus clarkii</i> is a highly adaptable, tolerant, and fecund freshwater crayfish that inhabits a wide range of aquatic environments. It is an important crustacean model organism that is used in many research fields, including animal behavior, environmental stress and toxicity, and studies of viral infection. Despite its widespread use, knowledge of the crayfish genome is very limited and insufficient for meaningful research. This is the use of next-generation sequencing techniques to analyze the crayfish transcriptome. A total of 324.97 million raw reads of 100 base pairs were generated, and a total of 88,463 transcripts were assembled <i>de novo</i> using Trinity software, producing 55,278 non-redundant transcripts. Comparison of digital gene expression between four different tissues revealed differentially expressed genes, in which more overexpressed genes were found in the hepatopancreas than in other tissues, and more underexpressed genes were found in the testis and the ovary than in other tissues. Gene ontology (GO) and KEGG enrichment analysis of differentially expressed genes revealed that metabolite- and immune-related pathway genes were enriched in the hepatopancreas, and DNA replication-related pathway genes were enriched in the ovary and the testis, which is consistent with the important role of the hepatopancreas in metabolism, immunity, and the stress response, and with that of the ovary and the testis in reproduction. It was also found that 14 vitellogenin transcripts were highly expressed specifically in the hepatopancreas, and 6 transcripts were highly expressed specifically in the ovary, but no vitellogenin transcripts were highly expressed in both the hepatopancreas and the ovary. These results provide new insight into the role of vitellogenin in crustaceans. In addition, 243,764 SNP sites and 43,205 microsatellite sequences were identified in the sequencing data. We believe that our results provide an important genome resource for the crayfish.</p></div

Classification of SNPs identified in the crayfish transcriptome.

<p>Classification of SNPs identified in the crayfish transcriptome.</p

Gene ontology (GO) classification of transcripts of <i>P. clarkii</i>.

<p>GO terms were processed by Blast2Go and categorized at level 2 under three main categories (biological process, cellular component, and molecular function).</p

Cluster of orthologous groups (COG) classification of putative proteins.

<p>Cluster of orthologous groups (COG) classification of putative proteins.</p

RT-PCR amplification and agarose gel (1.5%) electrophoresis of 20 transcripts.

<p>G01–G20: names of transcripts, represented transcript_ID given in Table S10 in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0110548#pone.0110548.s003" target="_blank">File S1</a>; 18S: 18S rRNA transcript; He: hepatopancreas; Mu: muscle; Ov: ovary; Te: testis; M: DNA marker.</p

Length distribution of assembled transcripts of <i>P. clarkii.</i>

<p>Length distribution of assembled transcripts of <i>P. clarkii.</i></p

KEGG pathways enriched in 4 crayfish tissues with Bonferroni-corrected p-values.

<p>KEGG pathways enriched in 4 crayfish tissues with Bonferroni-corrected p-values.</p

KEGG Classification of the genes.

<p>14596 transcripts were assigned to 311 KEGG pathways. The top 20 most abundant KEGG pathways are shown.</p

Differentially expressed genes analysis of four different crayfish tissues.

<p>hep: hepatopancreas; mu: muscle; ov: ovary; te: testis.</p