SparCL: Sparse Continual Learning on the Edge

Existing work in continual learning (CL) focuses on mitigating catastrophic forgetting, i.e., model performance deterioration on past tasks when learning a new task. However, the training efficiency of a CL system is under-investigated, which limits the real-world application of CL systems under resource-limited scenarios. In this work, we propose a novel framework called Sparse Continual Learning(SparCL), which is the first study that leverages sparsity to enable cost-effective continual learning on edge devices. SparCL achieves both training acceleration and accuracy preservation through the synergy of three aspects: weight sparsity, data efficiency, and gradient sparsity. Specifically, we propose task-aware dynamic masking (TDM) to learn a sparse network throughout the entire CL process, dynamic data removal (DDR) to remove less informative training data, and dynamic gradient masking (DGM) to sparsify the gradient updates. Each of them not only improves efficiency, but also further mitigates catastrophic forgetting. SparCL consistently improves the training efficiency of existing state-of-the-art (SOTA) CL methods by at most 23X less training FLOPs, and, surprisingly, further improves the SOTA accuracy by at most 1.7%. SparCL also outperforms competitive baselines obtained from adapting SOTA sparse training methods to the CL setting in both efficiency and accuracy. We also evaluate the effectiveness of SparCL on a real mobile phone, further indicating the practical potential of our method.Comment: Published at NeurIPS 2022 as a conference pape

Metagenomic Sequencing Identifies Highly Diverse Assemblages of Dinoflagellate Cysts in Sediments From Ships\u27 Ballast Tanks

Ships\u27 ballast tanks have long been known as vectors for the introduction of organisms. We applied next-generation sequencing to detect dinoflagellates (mainly as cysts) in 32 ballast tank sediments collected during 2001-2003 from ships entering the Great Lakes or Chesapeake Bay and subsequently archived. Seventy-three dinoflagellates were fully identified to species level by this metagenomic approach and single-cell polymerase chain reaction (PCR)-based sequencing, including 19 toxic species, 36 harmful algal bloom (HAB) forming species, 22 previously unreported as producing cysts, and 55 reported from ballast tank sediments for the first time (including 13 freshwater species), plus 545 operational taxonomic units (OTUs) not fully identified due to a lack of reference sequences, indicating tank sediments are repositories of many previously undocumented taxa. Analyses indicated great heterogeneity of species composition among samples from different sources. Light and scanning electron microscopy and single-cell PCR sequencing supported and confirmed results of the metagenomic approach. This study increases the number of fully identified dinoflagellate species from ballast tank sediments to 142 (\u3e 50% increase). From the perspective of ballast water management, the high diversity and spatiotemporal heterogeneity of dinoflagellates in ballast tanks argues for continuing research and stringent adherence to procedures intended to prevent unintended introduction of non-indigenous toxic and HAB-forming species

Alpha-Tubulin and Small Subunit rRNA Phylogenies of Peritrichs Are Congruent and Do Not Support the Clustering of Mobilids and Sessilids (Ciliophora, Oligohymenophorea)

Peritrich ciliates have been traditionally subdivided into two orders, Sessilida and Mobilida within the subclass Peritrichia. However, all the existing small subunit (SSU) rRNA phylogenetic trees showed that the sessilids and mobilids did not branch together. To shed some light on this disagreement, we tested whether or not the classic Peritrichia is a monophyletic group by assessing the reliability of the SSU rRNA phylogeny in terms of congruency with alpha-tubulin phylogeny. For this purpose, we obtained 10 partial alpha-tubulin sequences from peritrichs and built phylogenetic trees based on alpha-tubulin nucleotide and amino acid data. A phylogenetic tree from the alpha-tubulin and SSU rRNA genes in combination was also constructed and compared with that from the SSU rRNA gene using a similar species sampling. Our results show that the mobilids and sessilids are consistently separated in all trees, which reinforces the idea that the peritrichs do not constitute a monophyletic group. However, in all alpha-tubulin gene trees, the urceolariids and trichodiniids do not group together, suggested mobilids may not be a monophyletic group

Chrysogorgia pendula Versluys 1902

Chrysogorgia pendula Versluys, 1902 Figs. 52–71; Tables 8, 9 Chrysogorgia pendula Versluys, 1902: 73–74, figs. 113–118. Chrysogorgia pendula: Kükenthal, 1919: 526. Chrysogorgia pendula: Pasternak, 1981: 50. Material examined. MBM286359, station FX-Dive 172 (17°23′21″N, 153°5′32″E), Kocebu Guyot in Magellan Seamounts, 1353 m, 1 April 2018. MBM286360, station FX-Dive 132 (10°23′21″N, 140°9′28″E), a seamount (tentatively named as M4) on the Caroline Ridge, 1417 m, 14 August 2017. MBM286863, station FX-Dive 211 (10°2′59″N, 140°10′30″E), a seamount (tentatively named as M5) on the Caroline Ridge, 1473 m, 29 May 2019; MBM286864, station FX-Dive 221 (10°3′05″N, 140°9′24″E), M5 seamount, 2036 m, 9 June 2019. MBM286865, station FX-Dive 210 (10°4′44″N, 140°9′24″E), M5 seamount, 1895 m, 10 June 2019. MBM286866, station FXDive 224 (10°37′33″N, 140°5′22″E), a seamount (tentatively named as M8) on the Caroline Ridge, 1412 m, 12 June 2019; MBM286867, station FX-Dive 227 (10°37′54″N, 140°5′37″E), M8 seamount, depth 1695 m, 15 June 2019. MBM286868, station FX-Dive 226 (10°38′11″N, 140°4′5″E), M8 seamount, 1832 m, 14 June 2019. MBM286869, station FX-Dive 227 (10°37′56″N, 140°5′37″E), M8 seamount, 1711 m, 15 June 2019. MBM286870, station FXDive 221 (10°3′6″N, 140°9′30″E), M5 seamount, 1668m, 9 June 2019. Description. Colony typical bottlebrush-shaped and attached to rocky substrate. Branching sequencing 2/ 5L. Branches arranged closely at the stem base and became loose on the top. Branches usually slightly bend down and form an acute angle with the stem, and subdivided dichotomously. Distance between adjacent branch up to 15 mm, the first internode of branch up to 12 mm long and terminal branchlets up to 16 mm long. Nonterminal polyps usually with an oval body and became narrow at tentacle base, some of them pitcher-like, 1–2 mm tall. Terminal polyps usually cylindrical or conical with its base narrow, up to 3.5 mm tall. Polyps arranged one or two on first and medial internode, and up to four in terminal branchlets. Polyps in stem internodes very small and usually with opening mouth and eight tentacles. Eggs often observed in the oval body of polyps (e.g., Fig. 52C, E). Some polyps and branches occasionally covered with flexible filaments, which could not be digested by sodium hypochlorite, and usually form a slender and sharp point above the head of polyps (Fig. 66C, F–I). Scales in aboral face of tentacle rachis transversely arranged in a single row and a little curved with sparse fine warts, usually branched or forked with irregular shape, some of them nearly smooth and one end become narrow and sharp. Scales in pinnules longitudinally arranged, slender and a little curved, nearly smooth or with sparse fine warts, some of them with one end broad or forked and the other end narrow or sharp. Scales in polyp body wall obliquely or transversely arranged, elongate and nearly smooth with an obvious medial contraction, some of them lobed or forked with irregular shape, occasionally with finely toothed edges and protruding ridges on surface. Some small irregular scales often present and scattered on the outermost layer of the large scales on basal polyp body wall (Fig. 68H). Scales in coenenchyme arranged along to the branch, small and smooth, usually biscuit-like or elongate with a slight medial contraction, some of them crosswise and lobed with irregular shape. Plates or scales in the polyp mouth area near the tentacles sometimes present, small and thick, usually a little curved and coarse with many warts and irregular shape. For the morphological measurements of the ten specimens, see Table 8. Distribution and habitat. Banda Sea, 1595 m (Versluys 1902); Marcus-Necker Ridge, 2060–2100 m (Pasternak 1981); seamounts on the Caroline Ridge, 1412–2036 m; Kocebu Guyot in Magellan Seamounts, 1353 m. Remarks. Chrysogorgia pendula Versluys, 1902 is characterized by a typical bottlebrush-shaped colony, 2/5L branching sequence, pendulous branches, smooth biscuit-like scales in coenenchyme, irregular scales with a medial contraction in polyp body wall, irregular scales with sparse fine warts in tentacles and smooth scales usually with one end broad or forked and the other end narrow in pinnules. Our ten specimens match well with the original description of C. pendula in sclerite forms and pendulous branches, and their 28S rDNA sequences showed they are identical with the intraspecific differences (see the genetic analysis before), we thus identified as the same species. However, there are minor differences among the ten specimens including: (1) the colony is slender bottlebrush-shaped with a little curved stem in MBM286865, typical and regular bottlebrush-shaped in MBM286360, MBM286359, MBM286863, MBM286864, MBM286869 and MBM286870, bottlebrush-shaped with two large branches in MBM286866, relatively bushy and stout bottlebrush-shaped in MBM286867 and MBM286868; (2) scales in coenenchyme are more elongate in MBM286864 and MBM286867, more irregular in MBM286870; (3) scales in pinnules are more forked and irregular in MBM286864, MBM286867 and MBM286870; (4) small and thin sclerites with many warts are more abundant in MBM286869; (5) some polyps of MBM286869 covered with flexible filaments (Fig. 66C, F–I). All of these differences may be caused by different growth stage/environment and inadequate measurement, and are not constant features, and we tend to treat as the conspecific variation. The ten specimens of Chrysogorgia pendula Versluys, 1902 indicate this species have high intraspecific variations.Published as part of Xu, Yu, Zhan, Zifeng & Xu, Kuidong, 2023, Studies on western Pacific gorgonians (Anthozoa: Octocorallia, Chrysogorgiidae). Part 1: a review of the genus Chrysogorgia, with description of a new genus and three new species, pp. 1-107 in Zootaxa 5321 (1) on pages 83-87, DOI: 10.11646/zootaxa.5321.1.1, http://zenodo.org/record/820341

Ciliate Environmental Diversity Can Be Underestimated by the V4 Region of SSU rDNA: Insights from Species Delimitation and Multilocus Phylogeny of Pseudokeronopsis (Protist, Ciliophora)

Metabarcoding and high-throughput sequencing methods have greatly improved our understanding of protist diversity. Although the V4 region of small subunit ribosomal DNA (SSU-V4 rDNA) is the most widely used marker in DNA metabarcoding of eukaryotic microorganisms, doubts have recently been raised about its suitability. Here, using the widely distributed ciliate genus Pseudokeronopsis as an example, we assessed the potential of SSU-V4 rDNA and four other nuclear and mitochondrial markers for species delimitation and phylogenetic reconstruction. Our studies revealed that SSU-V4 rDNA is too conservative to distinguish species, and a threshold of 97% and 99% sequence similarity detected only one and three OTUs, respectively, from seven species. On the basis of the comparative analysis of the present and previously published data, we proposed the multilocus marker including the nuclear 5.8S rDNA combining the internal transcribed spacer regions (ITS1-5.8S-ITS2) and the hypervariable D2 region of large subunit rDNA (LSU-D2) as an ideal barcode rather than the mitochondrial cytochrome c oxidase subunit 1 gene, and the ITS1-5.8S-ITS2 as a candidate metabarcoding marker for ciliates. Furthermore, the compensating base change and tree-based criteria of ITS2 and LSU-D2 were useful in complementing the DNA barcoding and metabarcoding methods by giving second structure and phylogenetic evidence

Morphology and phylogenetic analysis of five deep-sea golden gorgonians (Cnidaria, Octocorallia, Chrysogorgiidae) in the Western Pacific Ocean, with the description of a new species

Explorations of seamounts in the Western Pacific Ocean and South China Sea resulted in collecting 18 specimens of golden gorgonians. Based on the morphology and the genetic analysis of mtMutS, they are described as one new species, Chrysogorgia carolinensis sp. nov., and four known species, including Chrysogorgia dendritica Xu, Zhan & Xu, 2020, Metallogorgia melanotrichos (Wright & Studer, 1889), Metallogorgia macrospina Kükenthal, 1919, and Pseudochrysogorgia bellona Pante & France, 2010. Chrysogorgia carolinensis belongs to the Chrysogorgia “group A, Spiculosae” with rods or spindles distributed in the polyp-body wall and tentacles, and differs from all of its congeners except C. dendritica by the 1/3L branching sequence and amoeba-shaped sclerites at the basal polyp body. The mtMutS sequence of C. carolinensis sp. nov. has six deletion mutations compared to those of its congeners, supporting the establishment of the new species. Although no genetic variability was observed between the closely related species C. dendritica and C. abludo Pante & Watling, 2012, the former is different from the latter by the apparently irregular sclerites in the polyp body wall. The two specimens of Metallogorgia melanotrichos match well with the original description except for relatively larger polyps, while the M. macrospina specimens have slightly smaller polyps than the holotype. The juvenile of Metallogorgia has an obvious morphological difference with the adults in the colony shape and branches, but they can be unified by the same polyps and sclerites as well as mitochondrial MutS sequences. Thus, the generic diagnosis of Metallogorgia is slightly extended to include the morphology of juveniles. The morphology of Pseudochrysogorgia bellona Pante & France, 2010, as a new record for the South China Sea, matches well with that of the original description. In the phylogenetic trees, the Chrysogorgia species are separated into two clades, and while Metallogorgia and Pseudochrysogorgia formed a sister clade

Morphological and Molecular Characterization of Five Species Including Three New Species of Golden Gorgonians (Cnidaria: Octocorallia) from Seamounts in the Western Pacific

Members of genus Iridogorgia Verrill, 1883 are the typical deep-sea megabenthos with only seven species reported. Based on an integrated morphological-molecular approach, eight sampled specimens of Iridogorgia from seamounts in the tropical Western Pacific are identified as three new species, and two known species I. magnispiralis Watling, 2007 and I. densispicula Xu, Zhan, Li and Xu, 2020. Iridogorgia flexilis sp. nov. is unique in having a very broad polyp body base with stout and thick scales. Iridogorgia densispiralis sp. nov. can be distinguished by rods present in both polyps and coenenchyme, and I. verrucosa sp. nov. is characterized by having numerous verrucae in coenenchyme and irregular spindles and scales in the polyp body wall. Phylogenetic analysis based on the nuclear 28S rDNA indicated that I. densispiralis sp. nov. showed close relationships with I. splendens Watling, 2007 and I. verrucosa sp. nov., and I. flexilis sp. nov. formed a sister clade with I. magnispiralis. In addition, due to Rhodaniridogorgia fragilis Watling, 2007 nested into the Iridogorgia clade in mtMutS-COI trees and shared highly similar morphology to the latter, we propose to eliminate the genus Rhodaniridogorgia by establishing a new combination Iridogorgia fragilis (Watling, 2007) comb. nov. and resurrecting I. superba Nutting, 1908

Studies on western Pacific gorgonians (Anthozoa: Octocorallia, Chrysogorgiidae). Part 1: a review of the genus Chrysogorgia, with description of a new genus and three new species

Xu, Yu, Zhan, Zifeng, Xu, Kuidong (2023): Studies on western Pacific gorgonians (Anthozoa: Octocorallia, Chrysogorgiidae). Part 1: a review of the genus Chrysogorgia, with description of a new genus and three new species. Zootaxa 5321 (1): 1-107, DOI: https://doi.org/10.11646/zootaxa.5321.1.1, URL: http://dx.doi.org/10.11646/zootaxa.5321.1.

Iridogorgia densispicula Xu & Zhan & Li & Xu 2020, n. sp.

<i>Iridogorgia densispicula</i> n. sp. <p>(Figs 2 and 3; Table 1)</p> <p>urn:lsid:zoobank.org:act: EC438B59-1AA6-4E32-BC6C-2011D5D67F0B</p> <p> <b>Holotype:</b> MBM286538, collected from the station FX-Dive 137 (10°35.10’N, 140°07.46’E) of a seamount located at the Caroline Plate with water depth of 1204 m, on 21 August 2017. GenBank accession MK 431864.</p> <p> <b>Diagnosis:</b> Colony slender. Polyps with bud-like shape, towards the branch end situated at an acute angle. Sclerites densely arranged in polyps and branches, including the inter-polyp coenenchyme. Tentacles covered with rods, forming eight distinct columns. Scales at bases of polyp usually with sharp ends, and long spindles in coenenchyme.</p> <p> <b>Description:</b> In vivo, colony with a slender stem and four helical turns on the top, growing on a rocky bottom (Fig. 2A). Specimen about 93 cm in height, with a part of straight stem about 28 cm. Each helical turn about 13–15 cm in height and 3–4 cm in diameter. Central axis 3 mm in diameter at base with yellow metallic luster. Branches arranged along one side, about 3–5 mm apart. The shortest branch at the top 5.4 cm, and the longest up to 23.8 cm long with 37 polyps counted (Fig. 2B). Polyps approximately 3–7 mm apart, with a bud-like shape, 1–3 mm in height, and 3–4 mm in width at base. Polyp with an expanded base and tilted at an acute angle with branch (Fig. 2C). Golden eggs present at base and visible under the microscope (Fig. 2D). Tentacles 2–3 mm long, forming eight obvious parallel columns terminating at base. A few verrucae in polyps and branches.</p> <p>Sclerites densely arranged in polyps and branches including the inter-polyp coenenchyme, commonly with small protuberances on surface, sometimes slightly branched (Fig. 2E). Rods longitudinally arranged in tentacles, rarely crossed, sometimes with bulgy edges and large warts, and measuring 164–945 × 27–98 μm with an average of 462 × 38 μm (Fig. 3A). Slender spindles in coenenchyme mostly with two sharp ends, occasionally crossed, and measuring 215–835 × 25–60 μm with an average of 545 × 42 μm (Fig. 3B). Spindle-like scales in polyp bases, usu- ally with a broad waist and sharp ends, sometimes with a slight midway constriction, measuring 102–627 × 16–110 μm with an average of 312 × 59 μm (Fig. 3C).</p> <p> <b>Etymology:</b> Composite of the Latin adjective <i>densus</i> (dense) and the Latin noun <i>spicula</i> (spicule), referring to the densely arranged spicules, a distinct feature of the species.</p> <p> <b>Distribution:</b> Known only from the seamount in the Caroline Plate with water depth of 1204 m. Growing on a rocky bottom with the water temperature 3.6°C and the salinity 35.8.</p>Published as part of <i>Xu, Yu, Zhan, Zifeng, Li, Yang & Xu, Kuidong, 2020, Morphology and phylogenetic analysis of two new species of deep-sea golden gorgonians (Cnidaria: Octocorallia: Chrysogorgiidae) from seamounts in the Western Pacific Ocean, pp. 249-262 in Zootaxa 4731 (2)</i> on pages 251-254, DOI: 10.11646/zootaxa.4731.2.4, <a href="http://zenodo.org/record/3637861">http://zenodo.org/record/3637861</a&gt