The cosmopolitan echiniscid genus Hypechiniscus contains exclusively rare species. In this contribution, by combining statistical morphometry and molecular phylogeny, we present qualitative and quantitative aspects of Hypechiniscus diversity, which remained hidden under the two purportedly cosmopolitan species: H. gladiator and H. exarmatus. A neotype is designated for H. gladiator from Creag Meagaidh (Scotland), and an informal re-description is provided for H. exarmatus based on animals from Creag Meagaidh and the Isle of Skye (Inner Hebrides). Subspecies/forms of H. gladiator are suppressed due to the high developmental variability of the cirrus dorsalis. At the same time, four species of the genus are described: H. daedalus sp. nov. from Roan Mountain and the Great Smoky Mountains (Southern Appalachian Mountains, USA), H. flavus sp. nov. and H. geminus sp. nov. from the Yatsugatake Mountains (Honshu, Japan), and H. cataractus sp. nov. from the Malay Archipelago (Borneo and the Moluccas). Dorsal and ventral sculpturing, together with morphometric traits, are shown to be the key characters that allow for the phenotypic discrimination of species within the genus. Furthermore, the morphology of Hypechiniscus is discussed and compared to that of the most similar genera, Pseudechiniscus and Stellariscus. Finally, a diagnostic key to all recognized Hypechiniscus species is provided.

Thesis(M.Sc. Agricultural Management (Horticulture)) -- University of Limpopo, 2021 / Amaranthus species, with their adaptability to grow under various agro-ecologies and soil types, have gained considerable attention in food security due to their high nutritional content. However, various Amaranthus species are host to the root-knot (Meloidogyne species) nematodes, with limited information on how the pest could affect the nutritional composition of the crop. In other crops, infestation with Meloidogyne species have deleterious effects on accumulation of certain essential mineral nutrient elements. However, the influence of Meloidogyne species on essential mineral nutrient elements had not been documented on Amaranthus. The objectives of the study, therefore, were to determine the influence of infestation by Meloidogyne species on growth and accumulation of selected malnutrition elements in four exotic Amaranthus relative to the local cultivar under both greenhouse and field conditions. In the greenhouse study, hardened-off seedlings were transplanted into 20-cm diameter plastic pots containing a steam-pasteurised growing mixture. The 5 × 2 factorial experiments were arranged in a randomised complete block design, with five replications. The first and second factors were five Amaranthus cultivars and two Meloidogyne species, namely, M. incognita and M. javanica. At 60 days after inoculation, plant growth and nematode variables were assessed using standard procedures. Roots of all five Amaranthus cultivars were heavily galled, with limited cultivar × nematode interactions on plant variables. Additionally, the common factor that influenced either plant or nutrient element variables was the cultivar type, whereas those of nematodes were highly variable, particularly on nutrient elements. Three best performing cultivars were further tested under field conditions under nematode infested and untreated control plots. An exotic cv. ′Tanzania′ had higher dry shoot mass, plant height and stem diameter, and accumulated higher Ca and K content than ′Candatus′ and ′Local 33′. Overall, the cultivar × nematode interaction reduced Na content in leaf tissues of Amaranthus cultivars under field conditions. / University of Venda, University of Limpopo and Agricultural Research Council

A new cycad species, Cycas fushunensis sp. nov., is described from the Lutetian Jijuntun Formation at Fushun Coalmine, Liaoning Province, northeast China, based on a well-preserved partial frond containing about 15 leaflets. The fossil is characterized by a single strong vein per leaflet, decurrent leaflet base and haplocheilic stomata, suggesting that the fossil is attributed to the genus Cycas of Cycadaceae. Epidermal anatomical comparisons between the fossil and 17 selected modern Cycas species further indicate that C. fushunensis sp. nov. closely resembles Cycas panzhihuaensis Zhou et Yang, an endemic cycad to southwest China, due to characters shared, such as the straight anticlinal walls of both adaxial and abaxial epidermal cells and granular to striate cuticular characters on the internal surface of guard cell periclinal walls. The occurrence of close-to-modern Cycas from the early Cenozoic largely casts doubt on a hypothesis of the late Miocene differentiation of modern cycads, suggested by a recent molecular phylogenetic study.

Broad-scale niche models are good for examining the potential for invasive species occurrences, but can fall short in providing managers with site-specific locations for monitoring. Using Oklahoma as an example, where invasive bighead carp (Hypophthalmichthys nobilis) are established in certain reservoirs, but predicted to be widely distributed based on broad-scale niche models, we cast bighead carp reproductive ecology in a site-specific geospatial framework to determine their potential establishment in additional reservoirs. Because bighead carp require large, long free-flowing rivers with suitable hydrology for reproduction but can persist in reservoirs, we considered reservoir tributaries with mean annual daily discharge ≥8.5 cubic meters per second (m3/s) and quantified the length of their unimpeded portions. In contrast to published broad-scale niche models that identified nearly the entire state as susceptible to invasion, our site-specific models showed that few reservoirs in Oklahoma (N = 9) were suitable for bighead carp establishment. Moreover, this method was rapid and identified sites that could be prioritized for increased study or scrutiny. Our results highlight the importance of considering the environmental characteristics of individual sites, which is often the level at which management efforts are implemented when assessing susceptibility to invasion.

For the past 5 years we have been conducting a large-scale, multi-habitat inventory of the tardigrades in the Great Smoky Mountains National Park (U.S.A.) as part of the All Taxa Biodiversity Inventory (ATBI) (see www.dlia.org). In terrestrial habitats, we collected moss, lichen, and soil samples from 19 permanent ATBI plots, representing all major land cover types within the park. Each ATBI plot is 100 × 100 m. In each plot, when available, 16 moss samples, 16 lichen samples, and 4 soil samples were collected in paper bags and air dried in the laboratory. Specimens were isolated with LudoxAM centrifugation, and for each sample up to 50 adults plus eggs were individually mounted on microscope slides in Hoyer's medium and identified using phase contrast and DIC microscopy. Additional collections were made in the limestone caves of the Cades Cove region of the park, bird nests, and 13 different streams. To date (1-Jun-06), 589 samples have been collected, and of these 401 have been analyzed, yielding a total of 8133 identifiable tardigrades or, in some cases, species groups. A total of 73 species have been found in the park, 14 of which we believe are new to science. Seven species richness estimators have been developed to predict total species richness (see EstimateS 7.5 software, viceroy.eeb.uconn.edu/ estimates), and these were evaluated by comparing predictions from half of our data to the actual numbers from the total database. The results of this comparison indicate that different estimators work best in different habitats. Using the best estimators in each habitat, EstimateS 7.5 indicates that a total of 96 species are likely to occur throughout the park. Thus, Great Smoky Mountains National Park tardigrade diversity represents 10% of the world's known tardigrade fauna.

Summary. Despite its being the most efficacious drug for symptom reversal in Parkinson's disease (PD), there is concern that chronic levodopa (L-DOPA) treatment may be detrimental. In this paper we review the potential for L-DOPA to 1) autoxidize from a catechol to a quinone, and 2) generate other reactive oxygen species (ROS). Overt toxicity and neuroprotective effects of L-DOPA, both in vivo and in vitro, are described in the context of whether L-DOPA may accelerate or delay progression of human Parkinson's disease.

Every day more than half of the world consumes rice as a primary dietary resource. Thus, rice is one of the most important food crops in the world. Rice and its wild relatives are part of the genus Oryza. Studying the genome structure, function, and evolution of Oryza species in a comparative genomics framework is a useful approach to provide a wealth of knowledge that can significantly improve valuable agronomic traits. The Oryza genus includes 27 species, with 11 different genome types as identified by genetic and cytogenetic analyses. Six genome types, including that of domesticated rice - O. sativa and O. glaberrima, are diploid, and the remaining 5 are tetraploids. Three of the tetraploid species contain the CCDD genome types (O. grandiglumis, O. latifolia, and O. alta), which arose less than 2 million years ago. Polyploidization is one of the major contributors to evolutionary divergence and can thereby lead to adaptation to new environmental niches. An important first step in the characterization of the polyploid Oryza species is the generation of a high-quality reference genome sequence. Unfortunately, up until recently, the generation of such an important and fundamental resource from polyploid species has been challenging, primarily due to their genome complexity and repetitive sequence content. In this project, I assembled two high-quality genomes assemblies for O. grandiglumis and O. latifolia using PacBio long-read sequencing technology and an assembly pipeline that employed 3 genome assemblers (i.e., Canu/2.0, Mecat2, and Flye/2.5) and multiple rounds of sequence polishing with both Arrow and Pilon/1.23. After the primary assembly, sequence contigs were arranged into pseudomolecules, and homeologous chromosomes were assigned to their respective genome types (i.e., CC or DD). Finally, the assemblies were extensively edited manually to close as many gaps as possible. Both assemblies were then analyzed for transposable element and structural variant content between species and homoeologous chromosomes. This enabled us to study the evolutionary divergence of those two genomes, and to explore the possibility of neo-domesticating either species in future research for my PhD dissertation.

No description available.

North American bats face multiple threats, prompting an increase in bat research and conservation efforts in recent decades. Researchers often use acoustic monitoring, which entails recording bats? echolocation calls and subsequently identifying them to species, typically using automated software. Chapter 1 describes an acoustic monitoring program at eight U.S. national parks that aims to assess changes in bat populations over time. Data collected in 2016-2017 showed that activity levels of the little brown bat (Myotis lucifigus) decreased significantly while other species remained stable. Little brown bats have undergone similar population declines elsewhere due to the disease white-nose syndrome. Chapter 2 investigates whether different versions of bat call identification software are comparable to each other and how accurate they are. For the two software programs tested, agreement among versions was variable and species-dependent. Furthermore, newer versions were more conservative in assigning identifications, though not, on average, more accurate.

Thesis(M.Sc.(Plant Protection))-- University of Limpopo,2019 / Previously, cucurbitacin-containing phytonematicides that were drench-applied in black plastic containers filled with pasteurised loam soil when placed on the soil surface had no effect on suppression of population densities of root-knot (Meloidogyne species) nematodes. The active ingredients of cucurbitacin-containing phytonematicides, namely, the cucurbitacins, had been shown to be thermophilic, with the failure of the products explained from the view of the variability induced by container-type and aboveground positioning. The view was investigated further using Nemarioc-AL and Nemafric-BL phytonematicides as influenced by container-type and positioning on growth of tomato (Solanum lycopersicum L.) plants and suppression of M. incognita population densities. Tomato cv. ′Floradade′ seedlings were transplanted into 30-cm-diameter brown pot belowground, brown pot aboveground, black pot belowground, black pot aboveground, 5 L polyethylene plastic bag belowground and 5 L polyethylene plastic bag aboveground, each containing 5-dm3 steam-pasteurised sandy loam soil amended with Hygromix at 3:1 (v/v) ratio. Seedlings were inoculated with 2000 eggs and second-stage juveniles (J2) of M. incognita race 2, with Nemarioc-AL and Nemafric-BL phytonematicides applied once 17 days after inoculation in both Experiment 1 and Experiment 2. Also, standard cultural practices were applied throughout the trial. At 56 days after inoculation, container-type and positioning had significant effects on various plant growth and essential nutrient element variables in Experiment 1 and Experiment 2, except that the six treatments did not have significant effects on nutrient elements and nematode population densities in Experiment 2. Relative to brown plastic pot belowground, treatments either increased or decreased plant growth, essential nutrient elements and nematode densities in Experiment 1, with selective similaritiesin Experiment 2. Specifically, nematode variables except for J2 in soil and total nematode population densities were significantly affected by the treatments in Experiment 2. Relative to the standard, plastic bag belowground increased J2 in soil and total population in soil by 18%. In conclusion, both container-type and positioning had effects on the efficacy of phytonematicides on plant growth, accumulation of essential nutrient elements and suppression of nematode population densities. Consequently, in trials where cucurbitacin-containing phytonematicides are conducted in microplots, brown plastic pots with the belowground positioning should be used to enhance the efficacy of the phytonematicides in stimulating plant growth and suppression of nematode population densities.