Relationships Between Basal Cover and Forage Production

Percentage composition by species is an important measurement used in range ecology. It can be based on either basal cover or forage production. Most range managers are interested in composition based on production although composition by basal cover is easier and quicker to determine. Therefore, if the relationships between these two measurements were known, it would be possible to obtain date rapidly on basal cover and convert them to data representing production. The purpose of this project was to study the relationship between these two measurements. However, it must be considered preliminary as many years\u27 data will be necessary to establish an accurate correlation. This experiment was conducted on an ungrazed area of the mixed prairie situated near the Cedar Bluff reservoir in Trego County, Kansas. Data were gathered from two range sites, the upland and the break site. The upland soil was a deep, heavy, silty clay loam and supported a typical short grass vegetation dominated by blue grama (Bouteloua gracilis) and buffalo grass (Buchloe dactyloides). The break site was located on a gradual west-facing slope near the upland site. The calcareous soil was relatively shallow and supported primarily mid-grass vegetation dominated by blue grama, side-oats grama (Bouteloua curtipendula), little bluestem (Andropogon scoparius) and big bluestem (Andropogon gerardi). Square-foot quadrats, randomly located, were used to sample the vegetation. One hundred sampling units from the upland and 300 from the break site were taken. Data gathered included actual basal cover of all species, percentage composition based on basal cover by each species, and height of each species. The grasses were then clipped by species and bagged separately. When air dried, they were weighed to the nearest one-tenth of a gram. Composition by forage production was then calculated and available for comparison. Calculations were made of the mean, standard deviation, and standard error. Correlation coefficients were used to compare the relationship of basal cover, forage production and height of the dominant grasses. The upland site had a basal cover of 56.0 per cent. Percentage composition by basal cover was 66.1 per cent buffalo grass, 33.3 blue grama, and 0.6 per cent sand dropseed (Sporobolus cryptandrus). Percentage composition calculated from forage production was 53.4 per cent buffalo, 44.8 per cent blue grama and 1.8 per cent sand dropseed. The multiple correlation coefficients among basal area, height and yield for blue grama were 0.89 and for buffalo grass 0.93. Total basal cover on the break site was 16.1 per cent. Of this, blue grama made up 21.5 per cent, side-oats grama, 40.8, big bluestem 17.7, and little bluestem 11.7 per cent. Eight minor grasses accounted for the remaining 8.7 per cent. When per centage composition was based on forage production, blue grama made up 14.9 per cent, big bluestem 21.1, little bluestem 20.3, and side-oats grama 35.2 per cent. The multiple correlation coefficients among basal area, height and yield on this break site were 0.91 for big bluestem, 0.89 for little bluestem, 0.93 for blue grama, and 0.85 for side-oats grama. Although no definite conclusions could be reached from one year\u27s data, tentative multiple regression equations were derived for each of the major species. If their validity could be established, they could permit estimation of yield from date about basal area and height. Continued research is necessary to establish such a relationship

BBN For Pedestrians

The simplest, `standard' model of Big Bang Nucleosynthesis (SBBN) assumes three light neutrinos (N_nu = 3) and no significant electron neutrino asymmetry, leaving only one adjustable parameter: the baryon to photon ratio eta. The primordial abundance of any one nuclide can, therefore, be used to measure the baryon abundance and the value derived from the observationally inferred primordial abundance of deuterium closely matches that from current, non-BBN data, primarily from the WMAP survey. However, using this same estimate there is a tension between the SBBN-predicted 4He and 7Li abundances and their current, observationally inferred primordial abundances, suggesting that N_nu may differ from the standard model value of three and/or that there may be a non-zero neutral lepton asymmetry (or, that systematic errors in the abundance determinations have been underestimated or overlooked). The differences are not large and the allowed ranges of the BBN parameters permitted by the data are quite small. Within these ranges, the BBN-predicted abundances of D, 3He, 4He, and 7Li are very smooth, monotonic functions of eta, N_nu, and the lepton asymmetry. It is possible to describe the dependencies of these abundances (or powers of them) upon the three parameters by simple, linear fits which, over their ranges of applicability, are accurate to a few percent or better. The fits presented here have not been maximized for their accuracy but, for their simplicity. To identify the ranges of applicability and relative accuracies, they are compared to detailed BBN calculations; their utility is illustrated with several examples. Given the tension within BBN, these fits should prove useful in facilitating studies of the viability of proposals for non-standard physics and cosmology, prior to undertaking detailed BBN calculations.Comment: Submitted to a Focus Issue on Neutrino Physics in New Journal of Physics (www.njp.org

Sea floor bedforms and their influence on slope accommodation (2019)

We sincerely thank Petroleum Geo-Services (PGS) Investigação Petrolífera Limitada, and specifically David Hajovsky and Scott Opdyke, that kindly provided the dataset and allowed us to show these results. We would also like to thank Schlumberger for providing academic licenses of their software (Petrel). We are grateful to Associate Editor Kei Ogata for his support, and we sincerely thank reviewers Daniele Casalbore and Kamaldeen Omosanya for their comments and suggestions that significantly improved the quality of the manuscript.Peer reviewedPostprin

Interpreting syndepositional sediment remobilization and deformation beneath submarine gravity flows; a kinematic boundary layer approach

Turbidite sandstones and related deposits commonly contain deformation structures and remobilized sediment that might have resulted from post-depositional modification such as downslope creep (e.g. slumping) or density-driven loading by overlying deposits. However, we consider that deformation can occur during the passage of turbidity currents that exerted shear stress on their substrates (whether entirely pre-existing strata, sediment deposited by earlier parts of the flow itself or some combination of these). Criteria are outlined here, to avoid confusion with products of other mechanisms (e.g. slumping or later tectonics), which establish the synchronicity between the passage of overriding flows and deformation of their substrates. This underpins a new analytical framework for tracking the relationship between deformation, deposition and the transit of the causal turbidity current, through the concept of kinematic boundary layers. Case study examples are drawn from outcrop (Miocene of New Zealand, and Apennines of Italy) and subsurface examples (Britannia Sandstone, Cretaceous, UK Continental Shelf). Example structures include asymmetric flame structures, convolute lamination, some debritic units and injection complexes, together with slurry and mixed slurry facies. These structures may provide insight into the rheology and dynamics of submarine flows and their substrates, and have implications for the development of subsurface turbidite reservoirs

Invalidation of the Kelvin Force in Ferrofluids

Direct and unambiguous experimental evidence for the magnetic force density being of the form $M\nabla B$ in a certain geometry - rather than being the Kelvin force $M\nabla H$ - is provided for the first time. (M is the magnetization, H the field, and B the flux density.)Comment: 4 pages, 4 figure

The Cosmological Evolution of the Average Mass Per Baryon

Subsequent to the early Universe quark-hadron transition the universal baryon number is carried by nucleons: neutrons and protons. The total number of nucleons is preserved as the Universe expands, but as it cools lighter protons are favored over heavier neutrons reducing the average mass per baryon. During primordial nucleosynthesis free nucleons are transformed into bound nuclides, primarily helium, and the nuclear binding energies are radiated away, further reducing the average mass per baryon. In particular, the reduction in the average mass per baryon resulting from Big Bang Nucleosynthesis (BBN) modifies the numerical factor relating the baryon (nucleon) mass and number densities. Here the average mass per baryon, m_B, is tracked from the early Universe to the present. The result is used to relate the present ratio of baryons to photons (by number) to the present baryon mass density at a level of accuracy commensurate with that of recent cosmological data, as well as to estimate the energy released during post-BBN stellar nucleosynthesis.Comment: 5 pages; no figures; updated references; final version published in JCAP, 10 (2006) 01

Multidisciplinary analysis of a mummified cranium claimed to be that of a medieval execution victim

This article presents a multidisciplinary analysis of a human skull with preserved soft tissue curated by a small museum in Boscastle, Cornwall, UK. The skull lacks a mandible and is coated in a black tar-like substance. Records left by a previous museum curator (now deceased) claimed the skull to be the head of a medieval execution victim. The skull was purportedly recovered from a London church that was destroyed during the Second World War where it had been kept in a carved oak box. If these details are correct, the skull would appear to have been venerated as a relic. The skull and box have been analysed using a range of techniques including computerised tomography, laser scanning, microscopy, infrared spectroscopy and radiocarbon dating. These analyses demonstrated the skull in fact to be that of an Egyptian mummy dating from the Ptolemaic period. Other instances have been noted of parts of Egyptian mummies being presented as European saintly relics, and the ‘Boscastle skull’ would appear to be an example of such. A wider point illustrated by the work presented here is that sufficient application of modern analytical techniques may reveal considerable information regarding human remains which otherwise have little or no provenance. This point strengthens arguments for the retention of such remains by curating institutions

Response of the mantle to flat slab evolution: Insights from local splitting beneath Peru

The dynamics of flat subduction, particularly the interaction between a flat slab and the overriding plate, are poorly understood. Here we study the (seismically) anisotropic properties and deformational regime of the mantle directly above the Peruvian flat slab. We analyze shear wave splitting from 370 local S events at 49 stations across southern Peru. We find that the mantle above the flat slab appears to be anisotropic, with modest average delay times (~0.28?s) that are consistent with ~4% anisotropy in a ~30?km thick mantle layer. The most likely mechanism is the lattice-preferred orientation of olivine, which suggests that the observed splitting pattern preserves information about the mantle deformation. We observe a pronounced change in anisotropy along strike, with predominately trench-parallel fast directions in the north and more variable orientations in the south, which we attribute to the ongoing migration of the Nazca Ridge through the flat slab system

Palynofacies classification of the depositional elements of confined turbidite systems : Examples from the Gres d'Annot, SE France

Acknowledgements We thank BG Brasil for financial support for this project and permission to publish. BG Group is a wholly owned subsidiary of Royal Dutch Shell. McArthur is grateful to the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the scholarship 049/2012. The Agência Nacional do Petróleo (ANP) are thanked for supporting this project. Massimo Zecchin is thanked for handling this paper and Roberto Tinterri is thanked for his constructive review, in addition to an anonymous reviewer.Peer reviewedPostprin

Diffusion and jump-length distribution in liquid and amorphous Cu33_{33}Zr67_{67}

Using molecular dynamics simulation, we calculate the distribution of atomic jum ps in Cu$_{33}$Zr$_{67}$ in the liquid and glassy states. In both states the distribution of jump lengths can be described by a temperature independent exponential of the length and an effective activation energy plus a contribution of elastic displacements at short distances. Upon cooling the contribution of shorter jumps dominates. No indication of an enhanced probability to jump over a nearest neighbor distance was found. We find a smooth transition from flow in the liquid to jumps in the g lass. The correlation factor of the diffusion constant decreases with decreasing temperature, causing a drop of diffusion below the Arrhenius value, despite an apparent Arrhenius law for the jump probability