Ultra Model Sets 40 Al 50 ##HOT##
The TCL 4-Series, available at Sam's Club, has been named the "best budget TV" of 2019 by CNET. And as for best picture quality? That goes to the LG OLEDC9 Series, per CNET's reviewer, and Sam's Club carries those models, too.
Ultra Model Sets 40 Al 50
Sam's Club has TV deals on wall mount and freestanding models. We also sell TV stands are affordable prices. And don't forget to check out our TV Buying Guide. Consider Sam's Club your one-stop shop for all your home needs, whether you're looking for kitchen appliances, a new TV or nintendo.
It's a pity Shimano doesn't make it easier to put together a wide-range system like this. They could offer SGS versions of the Ultegra and 105 Shadow rear derailleurs, for example, with the capability to handle 11-40, 11-42 or even 11-46 cassettes. And they need to offer chainsets with smaller rings and front derailleurs that work with them. Maybe next year, eh?
One of the first things you see when shopping for a TV is its resolution. You'll often see the resolution slapped right on the box or even in the model name. 4k TVs started to dominate the TV market in the middle of the 2010s, and they soon took over from 1080p as the most common resolution found on TVs. Almost every TV from big manufacturers has a 4k resolution, and it's actually hard to find 1080p TVs now, but what exactly are the differences between each?
It's becoming harder to find 1080p TVs in the 2020s, and they're usually limited to small, entry-level models. If you have limited space and need a small TV, you'll likely need to get a 1080p model, since 4k TVs are usually available in larger sizes.
8k TVs are starting to hit the market with a few models, like the Samsung Q900TS 8k QLED. An 8k resolution has 7680 horizontal pixels and 4320 vertical pixels for a total of over 33 million pixels, which is four times more than 4k. This allows for an incredible amount of detail, but it may only be noticeable if you sit really close to the screen. There's also a limited amount of 8k content available, and it requires a large amount of bandwidth. Even the new HDMI 2.1 standard can only support uncompressed 8k content up to 30fps with chroma 4:4:4.
When you're shopping for a TV, it's likely you're going to get a 4k model. A TV's resolution can be its main selling point, as it's easy to throw the 4k label on any TV, but the resolution is only one small factor in the total picture quality. While 4k is an upgrade from 1080p, it may be hard to notice the difference in resolution if you sit far from the TV, or if you just watch 1080p content. Since most TVs now are 4k and it's hard to find 1080p models, you won't really have to choose between 4k and 1080p anyway.
We report sequencing and assembly of a reference human genome for GM12878 from the Utah/CEPH pedigree, using MinION R9.4 1D chemistry, including ultra-long reads up to 882 kb in length. GM12878 has been sequenced on a wide variety of platforms, and has well-validated variation call sets, which enabled us to benchmark our results20.
Alternative approaches to improve assembly accuracy using different base-callers and exploiting the ionic current signal were attempted on a subset of reads from chromosome 20. Assembly consensus improvement using raw output is commonly used when assembling single-molecule data. To quantify the effect of base-calling on the assembly, we reassembled the read sets from Metrichor and Scrappie with the same Canu parameters used for the whole-genome data set. While all assemblies had similar contiguity, using Scrappie reads improved accuracy from 95.74% to 97.80%. Signal-level polishing of Scrappie-assembled reads using nanopolish increased accuracy to 99.44%, and polishing with Illumina data brought the accuracy up to 99.96% (Table 1).
(a) SignalAlign methylation probabilities compared to bisulfite sequencing frequencies at all called sites. (b) Nanopolish methylation frequencies compared to bisulfite sequencing at all called sites. (c) SignalAlign methylation probabilities compared to bisulfite sequencing frequencies at sites covered by at least ten reads in the nanopore and bisulfite data sets; reads were not filtered for quality. (d) Nanopolish methylation frequencies compared to bisulfite sequencing at sites covered by at least ten reads in the nanopore and bisulfite data sets. A minimum log-likelihood threshold of 2.5 was applied to remove ambiguous reads. N = sample size, r = Pearson correlation coefficient.
We modeled the contribution of read length to assembly quality, predicting that ultra-long read data sets (N50 >100 kb) would substantially improve assembly contiguity (Fig. 4a). We developed a method to produce ultra-long reads by saturating the Oxford Nanopore Rapid Kit with high molecular weight DNA. In so doing we generated an additional 5 coverage (Supplementary Fig. 11). Two additional standard protocol flow cells generated a further 2 coverage and were used as controls for software and base-caller versions. The N50 read length of the ultra-long data set was 99.7 kb (Fig. 4b). Reads were impossible to align efficiently at first, because aligner algorithms are optimized for short reads. Further, CIGAR strings generated by ultra-long reads do not fit in the BAM format specification, necessitating the use of SAM or CRAM formats only ( -specs/issues/40). Instead, we used GraphMap37 to align ultra-long reads to GRCh38, which took >25K CPU hours (Supplementary Table 8). Software optimized for long reads, including NGM-LR38 and Minimap2 (ref. 39), were faster: Minimap2 took 60 CPU hours. More than 80% of bases were in sequences aligned over 90% of their length with GraphMap and more than 60% with minimap2. Median alignment identity was 81% (83 with minimap2), slightly lower than observed for the control flow cells (83.46%/84.64%) and the original data set (83.11%/84.32%). The longest full-length mapped read in the data set (aligned with GraphMap) was 882 kb, corresponding to a reference span of 993 kb.
(a) A model of expected NG50 contig size when correctly resolving human repeats of a given length and identity. The y axis shows the expected NG50 contig size when repeats of a certain length (x axis) or sequence identity (colored lines) can be consistently resolved. Nanopore assembly contiguity (GM12878 20, 30, 35) is currently limited by low coverage of long reads and a high error rate, making repeat resolution difficult. These assemblies approximately follow the predicted assembly contiguity. The projected assembly contiguity using 30 of ultra-long reads (GM12878 30 ultra) exceeds 30 Mbp. A recent assembly of 65 PacBio P6 data with an NG50 of 26 Mbp is shown for comparison (CHM1 P6). (b) Yield by read length (log10) for ligation, rapid and ultra-long rapid library preparations. (c) Chromosomes plot illustrating the contiguity of the nanopore assembly boosted with ultra-long reads. Contig and alignment boundaries, not cytogenetic bands, are represented by a color switch, so regions of continuous color indicate regions of contiguous sequence. White areas indicate unmapped sequence, usually caused by N's in the reference genome. Regions of interest, including the 12 50+ kb gaps in GRCh38 closed by our assembly as well as the MHC (16 Mbp), are outlined in red.
The addition of 5 coverage ultra-long reads more than doubled the previous assembly NG50 to 6.4 Mbp and resolved the MHC locus into a single contig (Fig. 4c). In comparison, a 50 PacBio GM12878 data set with average read length of 4.5 kb assembled with an NG50 contig size of 0.9 Mbp5. Newer PacBio assemblies of a human haploid cell line, with mean read lengths greater than 10 kb, have reached contig NG50s exceeding 20 Mbp at 60 coverage25. We subsampled this data set to a depth equivalent to ours (35) and assembled, resulting in an NG50 of 5.7 Mbp, with the MHC split into >2 contigs. The PacBio assembly is less contiguous, despite a higher average read length and simplified haploid genome.
Here we report that read lengths produced by the MinION nanopore sequencer were dependent on the input fragment length. We found that careful preparation of DNA in solution using classical extraction and purification methods can yield extremely long reads. The longest read lengths were achieved using the transposase-based rapid library kit in conjunction with methods of DNA extraction designed to mitigate shearing. We produced 5 coverage with ultra-long reads, and used this data set to augment our initial assembly. The final 35 coverage assembly has an NG50 of 6.4 Mb. Based on modeling we predict that 30 of ultra-long reads alone would result in an assembly with a contig NG50 in excess of 40 Mb, approaching the contiguity of the current human reference (Fig. 4c). We posit that there may be no intrinsic read-length limit for pore-based sequencers, other than from physical forces that lead to DNA fragmentation in solution. Therefore, there is scope to further improve the read-length results obtained here, perhaps through solid-phase DNA extraction and library preparation techniques, such as agar encasement.
With ultra-long reads we found the longest reads exceeded CIGAR string limitations in the BAM format, necessitating the use of SAM or CRAM ( -specs/issues/40). And, we were unable to complete an alignment of the ultra-long reads using BWA-MEM, and needed to adopt other algorithms, including GraphMap and NGM-LR, to align the reads. This required large amounts of compute time and RAM37,38,50. Availability of our data set has spurred the development of Minimap2 (ref. 39), and we recommend this long-read aligner for use in aligning ultra-long reads on a standard desktop computer. 350c69d7ab