RNA World and The Development of RNA Protocells

Origins of life research, also known as pre-biotic chemistry or astrobiology, aims to unravel the mystery of the first cell’s origin on Earth. This interdisciplinary field encompasses biology, chemistry, and physics, with the primary goal of understanding the conditions necessary for life to emerge from abiotic environments. The RNA world hypothesis suggests that early life initially used RNA instead of DNA to store genomic information and for enzymatic functions. Protocells, membrane-bound entities with metabolic processes and self-replication capabilities, likely preceded the emergence of true cells. The challenges associated with RNA world is currently an active field of research. Advancements in our understanding of artificial protocells could shed light on the conditions necessary for natural protocell formation as well as the feasibility of an RNA world

Fabrication techniques developed for small- diameter, thin-wall tungsten and tungsten alloy tubing

Report describes methods for the fabrication of tungsten and tungsten alloys into small-diameter, thin-wall tubing of nuclear quality. The tungsten, or tungsten alloy tube blanks are produced by double extrusion. Plug-drawing has emerged as an excellent secondary fabrication technique for the reduction of the overall tube dimensions

Countryside biogeography of neotropical herbaceous and shrubby plants

As human impacts on the environment intensify, the future of plant and animal biodiversity will depend increasingly on the floras surviving in human-dominated "countryside" habitats. To begin to characterize these floras for the Neotropics, we investigated the richness and composition of herbaceous and shrubby plant communities in six forested and deforested habitats, in three replicated study areas (7.5-km in diameter), of southern Costa Rica. We chose habitat types that are common throughout the tropics, to begin building a general understanding of both the habitats of origin and the diversity of countryside floras. Focal forest habitats were understory, 1- to 2-year-old tree-fall gaps, and riverbanks, all in primary forest. Focal deforested habitats were ungrazed road verges, grazed pasture, and riverbanks in grazed pasture. Non-riverbank habitats were sampled both near and far from. forest edge. In total, we sampled 772 species from 79 families, similar to 40% of the non-tree plant diversity of the region. Only 6% of identified species are known to be exotic. In each study area, understory and pasture plots were consistently species poor, while tree-fall gaps and road verges near forest were consistently the most species-rich habitats. In each study area, we found the same proportion of species restricted to forested habitats (similar to 45%) and deforested habitats (similar to 37%), and the same proportion of "countryside-habitat generalists" ( similar to 18%) occurring in both forested and deforested habitats. However, different forested habitats supported different proportions of country side-habitat generalists in each study area, although understory plots consistently 'supported the fewest generalists. Among forested habitats, riverbanks were the most similar floristically to deforested habitats. Pasture riverbanks and road verges near forest supported plant communities most similar to those in forested habitats. The uniqueness and richness of each habitat suggests that countrysides with diverse land uses can support many native herbaceous and shrubby plant species. As it becomes increasingly difficult to protect large tracts of undisturbed tropical forest, we suggest that conservation goals expand to encompass maintenance of heterogeneity in countryside landscapes

Diet of the west coast rock lobster Jasus Lalandii: Influence of lobster size, sex, capture depth, latitude and moult stage

Diets of male and female West Coast rock lobster Jasus lalandii in South Africa were compared across a large size range of 10–85 mm carapace length (CL). The diets of male rock lobsters were compared betweentwo different depths, different seasons, across the moult cycle, and among eight sites along the South-Western Cape coast. There was no significant difference in diet between male and female rock lobsters for any of thesize-classes examined. Male rock lobsters showed large differences in diet between small and large size-classes. The diet of small lobsters (80mm CL) fed on few species, and fish and ribbed mussels were their most abundant prey items. There were some dietary differences between individuals captured at 20 m and those collected at 50 m, but these differences were less marked than between the two sampling sites (the Knol and Olifantsbos). There was seasonal variation in diet at the Dassen Island and Olifantsbos sites. Cannibalism was highest during the moulting periods. Gut fullness varied seasonally at Dassen Island, and was consistently high at Olifantsbos. However, the proportion of the population feeding showed marked seasonal trends at both sites, tracking the commercial catch per unit effort of rock lobster. Ribbed mussels were a ubiquitous and dominant component of the diet at the eight sites sampled. However, south of Dassen Island, black mussels Choromytilus meridionalis were scarce in the diet of rock lobster and sponges predominated. Gut fullness was lowest at the northernmostsites

The potential for using acoustic tracking to monitor the movement of the West Coast rock lobster Jasus lalandii

Although acoustic tracking has been used to study the movement of several species of clawed and spiny lobsters, only recent technological advances have provided sufficiently small transmitters to examine the utility of using acoustic tracking as a means to analyse the movement of relatively small spiny lobsters, such as Jasus lalandii. The effect of the transmitter on the mobility of J. lalandii was tested in aquarium experiments and was shown to have no influence on movement in three separate experiments. Thereafter, adult male rock lobsters (86–98mm carapace length) were tracked in field trials for up to 32 days at Betty's Bay (n = 4) and Hermanus (n = 5) off the Western Cape, South Africa. Tracking J. lalandii in the field using acoustic tags was successful, even in areas with dense kelp beds and rocky outcrops. The signal from the transmitters was readily detectable from the surface and subsequent use of underwater tracking equipment enabled visual confirmation of the position of the rock lobsters. Lobsters moved significantly longer distances (>45m day−1) in the first two days following tagging than during any subsequent time period (<10m day−1). This suggests that transmitter attachment and/or handling altered the movement pattern for the first 72 hours after tagging. During the period of observation, J. lalandii displayed classical nomadic behaviour

Species and functional diversity of native and human-dominated plant communities

Despite growing attention to how human activities alter plant communities, little is known about the ecosystem consequences of these changes. We explore the relationship between species and functional diversity of herbaceous and shrubby plant communities in forested and deforested habitats in three Neotropical landscapes. We focus on six traits: pollination mechanism, dispersal mechanism, growth form, fruit type, fruit size, and seed size. We ask: (1) What is the relationship between species richness and functional diversity (trait state richness)? (2) Do species/functional diversity relationships differ between forested and deforested habitats? and (3) Are observed species/functional diversity patterns more consistent with ecological filtering or differentiation-based assembly processes? We show that species richness is often a weak surrogate for functional diversity, depending on the trait. Species/functional diversity relationships differ significantly between forested and deforested habitats, but the nature of-differences is trait dependent. Dispersal mechanism and fruit type number increased more rapidly in deforested than forested habitats, but the opposite was true for most other traits. Using a null model, we found evidence of ecological filtering for most traits in both habitats. Results demonstrate that deforested habitats do not necessarily contain lower functional diversity than forest but that the ecological assembly processes influencing community function in deforested communities differ dramatically from forest

A bridge between the RNA and protein worlds? Accelerating delivery of chemical reactivity to RNA and DNA by a specific short peptide (AAKK)4

AbstractBackground: RNA can catalyze diverse chemical reactions, leading to the hypothesis that an RNA world existed early in evolution. Today, however, catalysis by naturally occurring RNAs is rare and most chemical transformations within cells require proteins. This has led to interest in the design of small peptides capable of catalyzing chemical transformations.Results: We demonstrate that a short lysine-rich peptide (AAKK)4 can deliver a nucleophile to DNA or RNA and amplify the rate of chemical modification by up to 3400-fold. We also tested similar peptides that contain ornithine or arginine in place of lysine, peptides with altered stereochemistry or orientation, and peptides containing eight lysines but with different spacing. Surprisingly, these similar peptides function much less well, suggesting that specific combinations of amino acids, charge distribution, and stereochemistry are necessary for the rate enhancement by (AAKK)4.Conclusions: By appending other reactive groups to (AAKK)4 it should be possible to greatly expand the potential for small peptides to directly catalyze modification of DNA or RNA or to act as cofactors to promote ribozyme catalysis

Community Health Workers: Implementing a System in Kentucky

A Community Health Worker (CHW) is a frontline public health worker who is a trusted member of and/or has an unusually close understanding of the community served. This trusting relationship enables the CHW to serve as a liaison/link/intermediary between health/social services and the community to facilitate access to services and improve the quality and cultural competence of service delivery. A CHW also builds individual and community capacity by increasing health knowledge and self-sufficiency through a range of activities such as outreach, community education, informal counseling, social support and advocacy. (American Public Health Association) Recognized as professional members of the health care workforce who effectively address social determinants of health and reduce health disparities (US Department of Health and Human Services) Roles and Responsibilities: Outreach and community mobilization Community/cultural liaison Case management and care coordination Home-based support Health promotion and health coaching System navigation Participatory researc

The Effects of HB1519 Funding on Early Childhood Programs

Includes bibliographical reference.In 1998, the Missouri Legislature created the Early Childhood Care and Education Fund (HB1519). The Department of Elementary and Secondary Education and the Department of Social Services funded a three-year study that evaluated the development and care of children participating in programs across the state that were supported by HB1519 funds compared to children participating in programs that did not receive funding. Program quality was evaluated using the Infant-Toddler Environmental Rating Scale, the Family Daycare Environmental Rating Scale and the Early Childhood Environmental Rating Scale-Revised. Furthermore, the intellectual abilities of children who attended high quality programs were compared to the abilities of children who attended programs of lower quality using the Peabody Picture Vocabulary Test and the Woodcock-Johnson Test of Cognitive Abilities.Funded by the Missouri Department of Social Services and the Missouri Department of Elementary and Secondary Education