Biodiversity of Australian marine macroalgae — A progress report

The biodiversity of Australian macroalgae is assessed by reference to species numbers recorded for the various biogeographical and political regions. The figures show a marked disparity between northern and southern Australia, with the former apparently depauperate as compared to the rich flora recorded from Southern Australia. Whilst a reduction in numbers is expected when comparing tropical to temperate regions, the situation in Australia is greatly exaggerated by relative levels of collecting and research. The completion of an Australia-wide macroalgal flora will be severely hampered until additional effort is directed towards these unexplored regions

Interviews with HMA Directors: Major General J.M. Cowan

The Journal of Conventional Weapons Destruction is introducing a section dedicated to sharing the insights and experiences of those working in the field. This issue features HMA directors. Future issues will feature interviews with photojournalists, survivors, and veterans of the HMA community

The Lagrangian Loop Representation of Lattice U(1) Gauge Theory

It is showed how the Hamiltonian lattice $loop$ $representation$ can be cast straightforwardly in the Lagrangian formalism. The procedure is general and here we present the simplest case: pure compact QED. This connection has been shaded by the non canonical character of the algebra of the fundamental loop operators. The loops represent tubes of electric flux and can be considered the dual objects to the Nielsen-Olesen strings supported by the Higgs broken phase. The lattice loop classical action corresponding to the Villain form is proportional to the quadratic area of the loop world sheets and thus it is similar to the Nambu string action. This loop action is used in a Monte Carlo simulation and its appealing features are discussed.Comment: 13 pp, UAB-FT-341/9

The Energy Density of "Wound" Fields in a Toroidal Universe

The observational limits on the present energy density of the Universe allow for a component that redshifts like $1/a^2$ and can contribute significantly to the total. We show that a possible origin for such a contribution is that the universe has a toroidal topology with "wound" scalar fields around its cycles.Comment: 11 pages, 1figur

Opacity calculation for target physics using the ABAKO/RAPCAL code

Radiative properties of hot dense plasmas remain a subject of current interest since they play an important role in inertial confinement fusion (ICF) research, as well as in studies on stellar physics. In particular, the understanding of ICF plasmas requires emissivities and opacities for both hydro-simulations and diagnostics. Nevertheless, the accurate calculation of these properties is still an open question and continuous efforts are being made to develop new models and numerical codes that can facilitate the evaluation of such properties. In this work the set of atomic models ABAKO/RAPCAL is presented, as well as a series of results for carbon and aluminum to show its capability for modeling the population kinetics of plasmas in both LTE and NLTE regimes. Also, the spectroscopic diagnostics of a laser-produced aluminum plasma using ABAKO/RAPCAL is discussed. Additionally, as an interesting application of these codes, fitting analytical formulas for Rosseland and Planck mean opacities for carbon plasmas are reported. These formulas are useful as input data in hydrodynamic simulation of targets where the computation task is so hard that in line computation with sophisticated opacity codes is prohibitive

Clouds, shadows, or twilight? Mayfly nymphs recognise the difference

1. We examined the relative changes in light intensity that initiate night-time locomotor activity changes in nymphs of the mayfly, Stenonema modestum (Heptageniidae). Tests were carried out in a laboratory stream to examine the hypothesis that nymphs increase their locomotion in response to the large and sustained reductions in relative light intensity that take place during twilight but not to short-term daytime light fluctuations or a minimum light intensity threshold. Ambient light intensity was reduced over a range of values representative of evening twilight. Light was reduced over the same range of intensities either continuously or in discrete intervals while at the same time nymph activity on unglazed tile substrata was video recorded. 2. Nymphs increased their locomotor activity during darkness in response to large, sustained relative light decreases, but not in response to short-term, interrupted periods of light decrease. Nymphs did not recognise darkness unless an adequate light stimulus, such as large and sustained relative decrease in light intensity, had taken place. 3. We show that nymphs perceive light change over time and respond only after a lengthy period of accumulation of light stimulus. The response is much lengthier than reported for other aquatic organisms and is highly adaptive to heterogeneous stream environments

How well can the LHC distinguish between the SM light Higgs scenario, a composite Higgs and the Higgsless case using VV scattering channels?

A complete parton level analysis of ll + four jets l = e,mu and 3lv + two jets production at the LHC is presented, including all processes at order \ordEW, \ordQCD and \ordQCDsq when appropriate. The infinite Higgs mass scenario, which is considered as a benchmark for strong scattering theories and is the limiting case for composite Higgs models, and one example of a model incorporating a Strongly Interacting Light Higgs are confronted with the Standard Model light Higgs predictions. This analysis is combined with the results in the lv + four jets channel presented in a previous paper, in order to determine whether a composite Higgs signal can be detected as an excess of events in boson--boson scattering.Comment: Introduced some representative Feynman diagrams. Rearranged section 4. Typos fixed. Published in JHE

Differences in bacterial diversity, composition and function due to long-term agriculture in soils in the Eastern Free State of South Africa

Land-use change from natural to managed agricultural ecosystems significantly impacts soil bacterial diversity and function. The Eastern Free State (EFS) is one of the most productive agricultural regions in South Africa. However, no studies aiming to understand the changes in bacterial diversity, composition and function due to land-use change in this area have been conducted. This study investigated, using high-throughput 16S rRNA gene amplicon sequencing, the e ects of long-term agriculture on bacterial diversity, composition and putative function in the EFS by comparing microbiomes from lands that have been under agronomic activity for over 50 years to those from uncultivated land. Results indicate that agriculture increased bacterial diversity. Soil chemical analysis showed that land-use shifted soils from being oligotrophic to copiotrophic, which changed bacterial communities from being Actinobacteria dominated to Proteobacteria dominated. Predictive functional analysis using Phylogenetic Investigation of Communities by Reconstruction of Unobserved States (PICRUSt) suggested that agricultural soil was abundant in genes associated with plant fitness and plant growth promotion, while non-agricultural soil was abundant in genes related to organic matter degradation. Together, these results suggest that edaphic factors induced by long-term agriculture resulted in shifts in bacterial diversity and putative function in the EFS.Supplementary Material: Figure S1: Sunburst chart showing the total relative abundance of bacterial phyla detected in investigated samples, Figure S2: Rarefaction analyses of samples at phylum level, Figure S3: Unique and shared KEGG Orthologs (KOs) between the agricultural and non-agricultural soils, Figure S4: Extended error bar plot for the six active features (high-level subsystems) that had significant di erences between agricultural and non-agricultural samples, Figure S5. Extended error bar plot showing the abundances of functions associated with plant interaction that had significant di erences between agricultural and non-agricultural samples, Figure S6: Heat map showing di erences in relative abundance of the 50 most abundant bacterial genera as revealed by ClustVis statistical analysis, Figure S7. Relative abundance of di erent genera involved in plant growth promotion and plant fitness between agricultural and non- agricultural soils.This research was funded by Potatoes South Africa, grant specific unique reference number (UID) 105649.https://www.mdpi.com/journal/diversityam2020BiochemistryGeneticsMicrobiology and Plant PathologyPlant Production and Soil Scienc