Search

Over the last 50 years, access to new data and analytical tools has expanded the study of analytical paleobiology, contributing to innovative analyses of biodiversity dynamics over Earth's history. Despite—or even spurred by—this growing availability of resources, analytical paleobiology faces deep-rooted obstacles that stem from the need for more equitable access to data and best practices to guide analyses of the fossil record. Recent progress has been accelerated by a collective push toward more collaborative, interdisciplinary, and open science, especially by early-career researchers. Here, we survey four challenges facing analytical paleobiology from an early-career perspective: (1) accounting for biases when interpreting the fossil record; (2) integrating fossil and modern biodiversity data; (3) building data science skills; and (4) increasing data accessibility and equity. We discuss recent efforts to address each challenge, highlight persisting barriers, and identify tools that have advanced analytical work. Given the inherent linkages between these challenges, we encourage discourse across disciplines to find common solutions. We also affirm the need for systemic changes that reevaluate how we conduct and share paleobiological research.

Gels self-assembled from colloidal nanoparticles (NPs) translate the size-dependent properties of nanostructures to materials with macroscale volumes. Large spanning networks of NP chains provide high interconnectivity within the material necessary for a wide range of properties from conductivity to viscoelasticity. However, a great challenge for nanoscale engineering of such gels lies in being able to accurately and quantitatively describe their complex non-crystalline structure that combines order and disorder. The quantitative relationships between the mesoscale structural and material properties of nanostructured gels are currently unknown. Here, it is shown that lead telluride NPs spontaneously self-assemble into a spanning network hydrogel. By applying graph theory (GT), a method for quantifying the complex structure of the NP gels is established using a topological descriptor of average nodal connectivity that is found to correlate with the gel's mechanical and charge transport properties. GT descriptions make possible the design of non-crystalline porous materials from a variety of nanoscale components for photonics, catalysis, adsorption, and thermoelectrics.

With the overwhelming COVID‐19 pandemic in Africa, many other severe epidemics have been given low priority, such as viral hepatitis. Patient mortality due to viral hepatitis has raised concern to COVID‐19 patients due to compromise with undiagnosed hepatitis in Africa. The pandemic has worsened the control of the viral hepatitis epidemic as healthcare control facilities have moved their focus towards curbing COVID‐19 infections. However, different challenges have arisen to viral hepatitis patients because of low health attention that declines the progress of already diagnosed hepatitis patients. Follow‐up plans, routine testing and treatment plans for viral hepatitis are no longer as strict with the human resources transferred towards combating the pandemic. Thus, a global effort is required to abide by renewed recommendations to eradicate viral hepatitis in Africa that also fit the current picture of the COVID‐19 pandemic. The article discusses the current challenges viral hepatitis patients faced during the COVID‐19 pandemic and important recommendations that can see through these challenges in Africa.

Crinoids were among the most abundant marine benthic animals throughout the Palaeozoic, but their body size evolution has received little attention. Here, we compiled a comprehensive database on crinoid calyx biovolumes throughout the Palaeozoic. A model comparison approach revealed contrasting and complex patterns in body size dynamics between the two major crinoid clades (Camerata and Pentacrinoidea). Interestingly, two major drops in mean body size at around two mass extinction events (during the late Ordovician and the late Devonian respectively) are observed, which is reminiscent of current patterns of shrinking body size of a wide range of organisms as a result of climate change. The context of some trends (marked declines during extinctions) suggests the cardinal role of abiotic factors (dramatic climate change associated with extinctions) on crinoid body size evolution; however, other patterns (two intervals with either relative stability or steady size increase in periods between mass extinctions) are more consistent with biotic drivers.

Snails of the genus Cremnoconchus - the only freshwater members of the gastropod family Littorinidae - are endemic to the spray zones of numerous waterfalls in the Western Ghats of India. Cremnoconchus consists of nine described and possibly numerous undescribed species as many of these appear to be restricted to specific waterfalls. This is the first attempt at resolving the relationships between the various species in this genus and establishing its monophyly in the family. Further, we also undertake species delimitation analysis to characterize cryptic diversity in this group. Phylogenetic analyses based on nuclear and mitochondrial genes support the monophyly of Cremnoconchus within the family. A fossil-calibrated Bayesian time tree suggests that this freshwater lineage diverged from its marine counterparts around 90.40 million years ago. The separation of Cremnoconchus from its marine ancestors might have been facilitated by the break-up of Gondwana or fluctuating sea levels during this period. Species delimitation analysis retrieved 12 potentially undescribed species in this group. These species formed two distinct clades in the phylogeny, one largely confined to the northern Western Ghats and the other to the central Western Ghats. Species belonging to the northern and central Western Ghats seem to have separated around 56.11 mya, i.e. after the northern Western Ghats were formed. Additionally, spatial isolation due to the patchiness of suitable habitats (waterfalls) and low mobility might have facilitated their diversification.

Wide bandgap perovskites (>1.7 eV) find applications in multi-junction solar cells and semi-transparent absorbers for building integrated photo-voltaics. Here we present the improvement in morphology and power conversion efficiency (PCE) of two mixed halide perovskite compositions: MAPbIBr 2 and MAPbBr 3 by methyl amine (MA) vapor treatment. MA treatment improves the morphology and surface coverage leading to increase in open-circuit voltage (V oc ) and short-circuit current (J sc ). Further two polymers are used as hole-transporting materials which have better HOMO matching with perovskite than Spiro-OMeTAD and results in V oc of 1.12 V and 1.17 V for MAPbIBr 2 and MAPbBr 3 respectively compared to 0.95 V and 1.10 V of the corresponding devices with Spiro-OMeTAD as HTL.

Isolation of high molecular weight DNA from gastropod molluscs and its subsequent PCR amplification is considered difficult due to excessive mucopolysaccharides secretion which co-precipitate with DNA and obstruct successful amplification. In an attempt to address this issue, we describe a modified CTAB DNA extraction method that proved to work significantly better with a number of freshwater and terrestrial gastropod taxa. We compared the performance of this method with Qiagen(®) DNeasy Blood and Tissue Kit. Reproducibility of amplification was verified using a set of taxon-specific primers, wherein modified CTAB extracted DNA could be replicated at least four out of five times but kit extracted DNA could not be replicated. In addition, sequence quality was significantly better with CTAB extracted DNA. This could be attributed to the removal of polyphenolic compounds by polyvinyl pyrrolidone which is the only difference between conventional and modified CTAB DNA extraction methods for animals. The genomic DNA isolated using modified CTAB protocol was of high quality (A260/280 ≥ 1.80) and could be used for downstream reactions even after long-term storage (more than 2 years). ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s13205-020-2051-7) contains supplementary material, which is available to authorized users.

Earthworm, Eutyphoeus gammiei, homogenate (EGH) was screened for wound healing activity on human keratinocyte cell line, HaCat, by cell proliferation and migration assays. The maximum proliferation and migration of keratinocyte cells were observed at the dose of 25μg/ml. As cell proliferation and migration are key factors for wound healing, the study clearly suggests the potential role of earthworm species Eutyphoeus gammiei on wound healing. Keywords: Eutyphoeus gammiei, Keratinocyte, MTT assay, scratch assay.

The Seychelles archipelago is unique among isolated oceanic islands because it features an endemic radiation of caecilian amphibians (Gymnophiona). In order to develop population genetics resources for this system, we identified microsatellite loci using unassembled Illumina MiSeq data generated from a genomic library of Grandisonia alternans, a species that occurs on multiple islands in the archipelago. Applying a recently described method (PALFINDER) we identified 8001 microsatellite loci that were potentially informative for population genetics analyses. Of these markers, we screened 60 loci using five individuals, directly sequenced several amplicons to confirm their identity, and then used eight loci to score allele sizes in 64 G. alternans individuals originating from five islands. A number of these individuals were sampled using non-lethal methods, demonstrating the efficacy of non-destructive molecular sampling in amphibian research. Although two loci satisfied our criteria as diploid, neutrally evolving loci with the statistical power to detect population structure, our success in identifying reliable loci was very low. Additionally, we discovered some issues with primer redundancy and differences between Illumina and Sanger sequences that suggest some Illumina-inferred loci are invalid. We investigated cross-species utility for eight loci and found most could be successfully amplified, sequenced and aligned across other species and genera of caecilians from the Seychelles. Thus, our study in part supported the validity of using PALFINDER with unassembled reads for microsatellite discovery within and across species, but importantly identified major limitations to applying this approach to small datasets (ca. 1 million reads) and loci with small tandem repeat sizes.

Microhyla kodial sp. nov. (Fig. 3 A & B) Zoobank ID. urn:lsid:zoobank.org:pub: B78E690B-D70D-44CF-B88B-F2023A22F78D Holotype. NCBS-AY587, an adult female collected from marshy areas in Baikampady, Mangaluru, Dakshina Kannada District, Karnataka, India (12.9518 o N, 74.8089 o E; alt 6 m amsl), by VKK, RUK and NAA, 20:00–22:00 h on 28 th September 2016. Suggested common name: Mangaluru narrow-mouthed frog Etymology. This species is named after Mangaluru city, coastal city of Karnataka, India from where the species has been collected. Mangaluru is known as Kodial in Konkani language. The specific name is an invariable noun in the nominative singular in apposition to generic name. Paratypes. Four females (NCBS-AY588 to NCBS-AY591 ) and five males (NCBS-AY592 to NCBS-AY596), collected from the type locality on 28 th September 2016 between 20:00-22:00h by VKK, RUK and NAA. Diagnosis. The new species is assigned to Microhylidae by the possession of median spiracle in the tadpole stage (Matsui et al. 2013), and to the genus Microhyla owing to the following set of diagnostic characters as described by Parker (1934), Inger (1989) Matsui et al. (2013), Wijayathilaka et al. (2016), Seshadri et al. (2016a) & Khatiwada et al. (2017): Small sized adults with slender body and narrow head; eyes reduced with circular pupil; lack of small spine-like projection of skin at heel and elbow; supratympanic fold present; fingers without webbing; toes with basal webbing; vomerine teeth absent; tongue obovate, entire and free at the base; snout less than twice the diameter of eye; indistinct canthus rostralis; tympanum hidden by skin; palmar tubercles distinct; distinct ovoid shaped inner metatarsal tubercle and rounded outer metatarsal tubercle. Microhyla kodial sp. nov. can be distinguished from all other Microhyla from South and Southeast Asia by the following set of characters: (i) A small sized frog (SVL; male: 16.9–17.4 mm, n = 5 and female: 18.0– 20.4 mm, n = 5); (ii) snout rounded in dorsal and ventral view, canthus rostralis indistinct, snout protrudes beyond mouth in ventral view; (iii) tongue obovate with tip pointed, margin smooth, lingual papilla absent; (iv) absence of lateral dermal fold (dark band) from behind the eye to groin; (v) absence of vertebral stripe (dorsal median line); (vi) absence of superciliary tubercles; (vii) tympanum indistinct hidden by skin; (viii) supratympanic fold present; (ix) head triangular, wider than long; (x) olive-green band on head, forms an arch at about half-length of upper eyelid between the eyes, this distinct band continues as a pattern on dorsum till the vent; (xi) skin tuberculated on dorsum, venter smooth; (xii) grayish-black throat in males; (xiii) first finger is longer than half the length of second finger; (xiv) finger and toe disc without dorsal median groove; (xv) palmar tubercles are well developed, with outer being round and large and inner small and ovoid; (xvi) webbing is absent between the fingers, webbing between the toes is basal; (xvii) inner and outer metatarsal tubercle present, inner metatarsal tubercle is ovoid, half the length of outer metatarsal tubercle which is almost rounded in shape. Description of holotype (Voucher No. NCBS–AY587, measurements in mm, Fig. 4 A–K; Table 2). Smallsized, adult female (SVL = 18.3). Head small, triangular, wider than long (HW = 4.5; HL = 4.0). Snout acute and rounded in both dorsal and ventral views; rounded in lateral view, upper jaw protrudes slightly in ventral view. Snout length (SL = 2.2) 1.22 times longer than the horizontal diameter of the eye (EL = 1.8). Canthus rostralis indistinct, loreal region concave. Interorbital space sloping towards snout, 1.9 times larger than maximum width of upper eyelid and 1.36 times wider than internarial distance (IUE = 1.9; UEW = 1.0; IN = 1.4). The distance between posterior margins of eyes 1.47 times that of anterior margins (IBE = 4.4; IFE = 3.0). Nostrils are rounded, without any flap, closer to tip of snout than to eye (NS = 0.7; EN = 1.4). Tongue relatively large, obovate, free at base and with smooth margin, lingual papilla absent. Vomerine ridge absent. Tympanum indistinct, supratympanic fold prominent; extending from posterior corner eye to near the insertion of forelimb axilla. Eyes small (EL = 1.8), pupil-rounded. Paratype 5 Paratype 6 Paratype 7 Paratype 8 Paratype 9 Mean±SD Holotype Paratype 1 Paratype 2 Paratype 3 Paratype 4 Mean±SD (592) (593) (594) (595) (596) (587) (588) (589) (590) (591) Male Male Male Male Male Female Female Female Female Female SVL 16.9 17.2 17.4 16.9 17.4 17.16±0.25 18.3 19.2 18 20.4 19.9 19.16±1.02 HW 4.3 4.4 4.3 4.4 4.5 4.38±0.08 4.5 4.7 4.8 4.6 4.7 4.66±0.11 HL 4 3.9 3.8 4 3.9 3.92±0.08 4 4.1 4.2 4.2 4.3 4.16±0.11 HD 2.4 2.1 2.7 2 2.1 2.26±0.28 2.7 2.6 2.6 2.6 2.7 2.64±0.05 IUE 1.8 1.8 1.9 1.7 1.6 1.76±0.11 1.9 2.2 2.1 2 2.1 2.06±0.11 UEW 0.9 1.1 1.2 0.9 1 1.02±0.13 1 1 1.1 1.1 1.2 1.08±0.08 SL 2.5 2.1 2.3 2 1.9 2.16±0.24 2.2 2.2 2.1 2.1 2 2.12±0.08 EL 1.6 1.5 1.8 1.6 1.5 1.6±0.12 1.8 2 1.9 1.7 1.9 1.86±0.11 MN 3.5 2.9 3.4 3 3.1 3.18±0.25 3.9 3.6 3.2 3.4 3.5 3.52±0.25 MFE 2.9 2.4 2.9 2.3 2.2 2.54±0.33 2.4 2 2.3 2.3 2.1 2.22±0.16 MBE 2.1 1.3 1.5 1.7 1.6 1.64±0.29 1.7 1.6 1.7 1.5 1.3 1.56±0.16 IN 1.3 1.4 1.4 1.4 1.4 1.38±0.04 1.4 1.4 1.5 1.5 1.4 1.44±0.05 IFE 3.1 3 3.1 2.9 2.7 2.96±0.16 3 3.1 3.1 3.3 2.9 3.08±0.14 IBE 4.2 4.2 4.4 4.1 4.1 4.2±0.12 4.4 4.6 4.5 4.6 4.8 4.58±0.14 NS 0.7 0.6 0.7 0.7 0.7 0.68±0.04 0.7 0.9 0.8 0.7 0.8 0.78±0.08 EN 1.4 1.4 1.3 1.2 1.3 1.32±0.08 1.4 1.2 1.2 1.2 1.3 1.26±0.08 FLL 2.5 2.6 2.7 2.4 3 2.64±0.23 3.1 3.2 2.9 3.1 3 3.06±0.11 HAL 3.5 3.8 3.5 3 3.8 3.52±0.32 3.9 4.1 3.5 2.7 3.9 3.62±0.55 FD1 0.1 0.2 0.1 0.1 0.2 0.14±0.05 0.1 0.2 0.1 0.2 0.2 0.16±0.05 FD2 0.2 0.3 0.2 0.2 0.2 0.22±0.04 0.2 0.2 0.2 0.3 0.3 0.24±0.05 FD3 0.3 0.2 0.2 0.2 0.1 0.2±0.07 0.3 0.2 0.2 0.2 0.3 0.24±0.05 FD4 0.2 0.2 0.2 0.2 0.2 0.2±0 0.3 0.3 0.2 0.3 0.3 0.28±0.04 FW1 0.1 0.1 0.1 0.2 0.1 0.12±0.04 0.1 0.2 0.1 0.2 0.2 0.16±0.05 FW2 0.2 0.2 0.2 0.2 0.2 0.2±0 0.2 0.2 0.2 0.3 0.3 0.24±0.05 FW3 0.2 0.2 0.2 0.2 0.1 0.18±0.04 0.2 0.2 0.2 0.3 0.3 0.24±0.05 FW4 0.2 0.1 0.2 0.2 0.2 0.18±0.04 0.2 0.2 0.2 0.3 0.3 0.24±0.05 FIL 0.6 0.7 0.6 0.6 0.6 0.62±0.04 0.8 0.7 0.7 0.9 0.8 0.78±0.08 ……continued on the next page Forelimb shorter than hand length (FLL = 3.1; HAL = 3.9). Fingers short, relative lengths of fingers I Skin texture and colour in preservative. Skin of dorsum, snout, between eyes, sides of head, upper part of flanks, forelimbs and hind limbs is slight to moderately tuberculated; ventral skin is smooth. Dorsal coloration pale gray; upper eyelid is dark gray in color. A light olive-green band between the eyes. Forelimbs and hind limbs light brown with dark brown cross bands. Cross bands are distinct in shank and foot. Ventral region pale cream colored; throat has white blotches near the margins of lower jaw and lower margin of the upper jaw; light yellow pigmentation at the junction of forelimbs. Limbs are pale in color compared to the body. Skin texture and color in life. Skin has small to medium sized tubercles all over the dorsum, faint tubercles on foot (not visible in preserved specimens). Skin on the underside is smooth. Overall grayish-brown in color with thick dark olive-green band on head, forming an arch at about half-length of upper eyelid between the eyes, this distinct band continues as a pattern on dorsum till the vent. Dark olive-green to dark-brown cross bands are prominent in forearm, feet, thigh, shank and toes. Supratympanic fold shows black pigmentation. Iris brown/black with golden yellow mottles. Pupil black. Ventral parts creamish-white throughout. Variation. Sexes dimorphic, females larger than males (SVL: males, 16.9–17.4 mm, n = 5; females, 18.0– 20.4 mm, n = 5). Grayish-black subgular vocal sac present in males. Gravid females contained un-pigmented eggs, which were visible in the belly near the groin. Advertisement call description. Microhyla kodial sp. nov. makes characteristic sounds with continuous notes ‘Ttrrrt…… ttrrrt….ttrrrt….’. It is observed that there are 2 to 7 pulses in each call (6±2 pulses, n= 50) with pulse rate of 14.97±1.38 pulses/s. Average dominant frequency was 3752.16±233.06 Hz (range: 3359.20–4220.50 Hz) and call duration was 0.33± 0.07 s. (range: 0.11– 0.42 s.). Waveform and spectrogram of sample calls of Microhyla kodial sp. nov. is shown in Fig. 5. Summary statistics for call characteristics is given in the Table 4. A video clip of advertisement call of M. kodial is at https://youtu.be/B0Bj8xWng8k

Effective conservation action relies on access to the best-available species data. Reptiles have often been overlooked in conservation prioritization, especially because of a paucity of population data. Using data for 549 reptile populations representing 194 species from the Living Planet database, we provide the first detailed analysis of this database for a specific taxonomic group. We estimated an average global decline in reptile populations of 54–55% between 1970 and 2012. Disaggregated indices at taxonomic, system, and biogeographical levels showed trends of decline, often with wide confidence intervals because of a prevalence of short time series. We assessed gaps in our reptile time-series data and examined what types of publication they primarily originated from to provide an overview of the range of data sources captured in the Living Planet database. Data were biased toward crocodilians and chelonians, with only 1% and 2% of known lizard and snake species represented, respectively. Pop...