1,877 research outputs found
Constraints on the development of coal mining in arctic Alaska based on review of Eurasian arctic practices
Arctic Alaska's enormous reserves of coal may be a significant future source of energy for the United States and for the Pacific Basin. Large coal reserves have been developed in the Arctic portions of Eurasia, where
problems similar to those that might be encountered in Alaska have already been faced. To determine the nature of these problems, the Mineral Industry
Research Laboratory of the University of Alaska, under contracts S 0133057 with the U.S. Bureau of Mines, has conducted a literature review on Eurasian coal mining and visited mines in Svalbard, Norway; Carmacks, Y.T.; and Healy, Alaska. The purpose was to establish the most significant physical constraints which may apply to the eventual development of Northwestern Arctic Alaskan coal.Contract S 0133057 with the U.S. Bureau of Mine
Parenting Styles and Influences of Millennial Parents in the Development of Values System of Grade 7 Learners in Negros Occidental: A Case Study
This qualitative research determined the parenting styles and influences of millennial parents in the values development system of Grade 7 learners in Negros Occidental: A case study. Diana Baumrind describes three parenting styles that affect the values development of children (Santrock, 2017) but in Nancy Darling (1999) cited by Situmorang (2021) in his study perceived parenting styles urges that parenting styles focus on four typologies; authoritative, authoritarian, indulgent and uninvolved. Influences of millennial parents in terms of character and religious aspects of millennial parents (Moriss, 2022) may have a role in the values development system for their children. A case study approach was used to gather primary data through in- depth interviews with our ten (10) millennial participants in Negros Occidental. Thematic analysis was used to analyze the classifications and present themes or patterns that relate to the data with the following steps: finalizing data, assigning preliminary code, searching for themes, reviewing themes, defining and naming themes, and producing reports (Braun & Clarke, 2006). The findings revealed that the majority of the study concluded that the authoritative parenting style is the parenting style of millennial parents prefer to employ, which affects or influence the values development system of their children positively. The study shows that the love, respect, open communication, and self-discipline of millennial parents influence the opportunities to improve their children's family significantly in helping their children build and refine their positive values development system. The study was organized into five parts. First, the introduction. Second, the theoretical framework. Third part is the review of the related literature about parenting styles, values development system, and influences of millennial parents. Fourth part is the purpose of the study and the research questions. The fifth part is the Research methodology which includes research design and research procedure and sampling. The sixth part is the results and discussion. Lastly, are the conclusion and recommendations of the research
Accumulation of plutonium in mammalian wildlife tissues: comparison of recent data with the ICRP distribution models
We examined the distribution of plutonium (Pu) in the tissues of mammalian wildlife to address the paucity of such data under environmental exposure conditions. Pu activity concentrations were measured in Macropus rufus (red kangaroo), Oryctolagus cuniculus (European rabbit), and Pseudomys hermannsburgensis (sandy inland mouse)inhabiting the relatively undisturbed, semi-arid conditions at the former Taranaki weapons test site at Maralinga, Australia. Of the absorbed Pu (distributed via circulatory and lymph systems) accumulation was foremost in bone (83% ±10% SD), followed by muscle (9% ±10%), liver (7% ±7%), kidneys (0.5% ±0.3%), and heart (0.4% ±0.4%). The bone values are higher than those reported in ICRP 19 and 48 (45-50% bone), while the liver values are lower than ICRP values (30-45% liver). The ICRP values were based on data dominated by relatively soluble forms of Pu, including prepared solutions and single-atom ions produced by decay following the volatilisation of uranium during nuclear detonation (fallout Pu, ICRP 1986). In contrast, the Maralinga data relates to low-soluble forms of Pu used in tests designed to simulate accidental release and dispersal. We measured Pu in lung, GI-tract and the skin and fur as distinct from the absorbed Pu in bone, liver, muscle, and kidneys. Compared with the mean absorbed activity concentrations, the results for lung tissues were higher by up to one order of magnitude, and those in the GI tract contents and the washed skin/fur were higher by more than two orders of magnitude. These elevated levels are consistent with the presence of low-soluble Pu, including particulate forms, which pass through, or adhere upon, certain organs, but are not readily absorbed into the bloodstream. This more transitory Pu can provide dose to the lung and GI tract organs, as well as provide potential transfer of contamination when consumed in predator-prey food chains, or during human foodstuff consumption. For example, activity concentrations in O. cuniculus edible samples prepared according to traditional aboriginal methods were more than two orders of magnitude higher than in muscle alone. The increase was due to inclusion of GI tract components and contents in the traditional method. Our results provide new insights into the sequestration of Pu in mammalian tissues under environmental exposure conditions. These results contrast with those related to the specific forms of Pu and exposure conditions upon which the ICRP models were based. However, they provide data relevant to the assessment of key environmental legacy waste sites, and of potential release scenarios for the low-soluble oxide forms in the growing worldwide inventory of Pu associated with power production
Highly divergent 16S rRNA sequences in ribosomal operons of Scytonema hyalinum (Cyanobacteria)
A highly divergent 16S rRNA gene was found in one of the five ribosomal operons present in a species complex currently circumscribed as Scytonema hyalinum (Nostocales, Cyanobacteria) using clone libraries. If 16S rRNA sequence macroheterogeneity among ribosomal operons due to insertions, deletions or truncation is excluded, the sequence heterogeneity observed in S. hyalinum was the highest observed in any prokaryotic species thus far (7.3± 9.0%). The secondary structure of the 16S rRNA molecules encoded by the two divergent operons was nearly identical, indicating possible functionality. The 23S rRNA gene was examined for a few strains in this complex, and it was also found to be highly divergent from the gene in Type 2 operons (8.7%), and likewise had nearly identical secondary structure between the Type 1 and Type 2 operons. Furthermore, the 16S-23S ITS showed marked differences consistent between operons among numerous strains. Both operons have promoter sequences that satisfy consensus requirements for functional prokaryotic transcription initiation. Horizontal gene transfer from another unknown heterocytous cyanobacterium is considered the most likely explanation for the origin of this molecule, but does not explain the ultimate origin of this sequence, which is very divergent from all 16S rRNA sequences found thus far in cyanobacteria. The divergent sequence is highly conserved among numerous strains of S. hyalinum, suggesting adaptive advantage and selective constraint of the divergent sequence
Reframing landscape fragmentation's effects on ecosystem services.
REVIEWLandscape structure and fragmentation have important effects on ecosystem services, with a common assumption being that fragmentation reduces service provision. This is based on fragmentation's expected effects on ecosystem service supply, but ignores how fragmentation influences the flow of services to people. Here we develop a new conceptual framework that explicitly considers the links between landscape fragmentation, the supply of services, and the flow of services to people. We argue that fragmentation's effects on ecosystem service flow can be positive or negative, and use our framework to construct testable hypotheses about the effects of fragmentation on final ecosystem service provision. Empirical efforts to apply and test this framework are critical to improving landscape management for multiple ecosystem services.Australian Research Council Discovery ProjectAustralian Research Council's Centre of Excellence for Environmental DecisionsNERCChile Ministry of EducationCSIRO Integrative Natural Resource Management postgraduate fellowshipsCOLCIENCIA
Non-simply-laced Lie algebras via F theory strings
In order to describe the appearance in F theory of the non--simply--laced Lie
algebras, we use the representation of symmetry enhancements by means of string
junctions. After an introduction to the techniques used to describe symmetry
enhancement, that is algebraic geometry, BPS states analysis and string
junctions, we concentrate on the latter. We give an explicit description of the
folding of D_{2n} to B_n of the folding of E_6 to F_4 and that of D_4 to G_2 in
terms of junctions and Jordan strings. We also discuss the case of C_n, but we
are unable in this case to provide a string interpretation.Comment: 24 pages, 3 figure
Dose modelling comparison for terrestrial biota: IAEA EMRAS II Biota Working Group's Little Forest Burial Ground scenario
Radiological doses to terrestrial biota have been examined in a model inter-comparison study that emphasised the identification of factors causing variability in dose estimation. Radiological dose rates were modelled for ten species representing a diverse range of terrestrial plant and animals with varying behavioural and physical attributes. Dose to these organisms may occur from a range of gamma (Co-60, Cs-137), beta (Sr-90) and alpha (Th-232, U-234 and U-238, Pu-238, Pu-239/240 and Am-241) emitting radionuclides. Whilst the study was based on a specific site - the Little Forest Burial Ground, New South Wales, and Australia - it was intended to be representative of conditions at sites throughout the world where low levels of radionuclides exist in soil due to waste disposal or similar activities
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