Microbes in the Anthropocene: spillover of agriculturally selected bacteria and their impact on natural ecosystems

Soil microbial communities are enormously diverse, with at least millions of species and trillions of genes unknown to science or poorly described. Soil microbial communities are key components of agriculture, for example in provisioning nitrogen and protecting crops from pathogens, providing overall ecosystem services in excess of $1000bn per year. It is important to know how humans are affecting this hidden diversity. Much is known about the negative consequences of agricultural intensification on higher-organisms, but almost nothing is known about how alterations to landscapes affect microbial diversity, distributions and processes. We review what is known about spatial flows of microbes and their response to land use change, and outline nine hypotheses to adva nce research of microbiomes across landscapes. We hypothesise that intensified agriculture selects for certain taxa and genes, which then “spill over” into adjacent unmodified areas and generate a halo of genetic differentiation around agricultural fields. Consequently, the spatial configuration and management intensity of different habitats combines with the dispersal ability of individual taxa to determine the extent of spillover, which can impact the functioning of adjacent unmodified habitats. When land scapes are heterogeneous and dispersal rates are high, this will select for large genomes that allow exploitation of multiple habitats , a process that may be accelerated through horizontal gene transfer. Continued expansion of agriculture will increase genotypic similarity, making microbial community functioning increasingly variable in human - dominated landscapes , potentially also impacting the consistent provisioning of ecosystem services . While the resulting economic costs have not been calculated, it is clear that dispersal dynamics of microbes should be taken into consideration to ensure that ecosystem functioning and services are maintained in agri - ecosystem mosaics

Computer performance analysis - Measurement objectives and tools

Objectives and measurements in computer performance analysi

The Health Related Components of Physical Fitness in People with Visual Impairment: A Systematic Review

Visual impairment is becoming progressively more common in America’s aging society. Physical inactivity contributes to the development of chronic health conditions. Therefore, it is important to understand the relationship between visual impairment and its impact on health related physical activity and fitness. The purpose of this systematic review is to examine the prevalence of physical activity and the five components of physical fitness in the visually impaired population. This review was limited to articles addressing individuals with “visual impairment,” as defined by the National Eye Institute. The data abstracted included documentation of visual impairment, physical activity rates, physical fitness measures, gender, age, number of participants, and sample size. Results confirm that persons with visual impairment tend to participate in physical activity significantly less than their sighted counterparts and are often less physically fit, especially in regards to body composition, cardiovascular endurance, and muscular strength. Consensus within the research attributes this decreased physical fitness to the lack of sufficient physical activity within the population. The observed lack of physical activity warrants intentionally improving upon the many physiopsychological and social factors which prevent visually impaired children and adults from having equal access to opportunities to engage regularly in physical fitness activities

The "Carex" fen vegetation of northern New South Wales

The floristic composition and extent of Carex-dominated fens in the New South Wales New England Tablelands Bioregion and Barrington Tops area (lat 28° 41’ S–31° 55’ S; long 151° 23’ E–152° 05’ E) together with outliers from the central west (Coonabarabran) are described from 81 full floristic survey sites. These fens contained 234 vascular plant taxa of which 27% were exotic. The fens were dominated by herbaceous vegetation (96% of taxa). Cluster analysis of cover-abundance scores of vascular plant taxa from 81 plots placed within 71 separate Carex fens revealed three alliances: 1) Carex appressa, 2) Scirpus polystachyus – Carex tereticaulis and 3) Carex gaudichaudiana and seven communities: (1) Carex appressa – Stellaria angustifolia Fen (2) Carex appressa Fen (3) Scirpus polystachyus – Carex appressa Fen (4) Carex tereticaulis Fen (5) Carex gaudichaudiana – Isachne globosa Fen (6) Carex sp. Bendemeer – Carex gaudichaudiana Fen (7) Carex gaudichaudiana – Glyceria australis Fen The distribution of alliances showed a pattern of east-west separation. The most easterly alliance shares many features with the Carex gaudichaudiana Alliance of the Monaro Region of southern NSW while the other alliances have no counterparts within the current literature. We estimate that up to 5 000 ha of fen vegetation survive in the New England Bioregion of which 90% is on grazed land and only 0.2% is within conservation reserves. Seven outstanding examples of fens remain; most are examples of Community 5, with one representing Community 6 and none representing the other five communities. Many of these are not secured, and none of those within reserves are in their ‘natural’ state. We therefore strongly encourage measures to allow closure of drains, the opening of dams, and the rehabilitation of important fens such as Bishops, Racecourse and New Country Swamps

Vegetation of montane bogs in east-flowing catchments of northern New England, New South Wales

The floristics of the montane bogs in east-flowing catchments of northern New England, north-eastern New South Wales (lat 28° 47’–31° 25’ S; long 151° 50’–152° 30’ E), are described from 62 full floristic survey sites (20 x 20 m in area). Eight vegetation communities are based on flexible UPGMA analysis of cover-abundance scores of vascular plant taxa. Shrub species make up 26% of the flora and herb species 69%, with the remaining taxa trees, climbers or vines. Shrub species were of little diagnostic value, as a few common dominants were shared across most communities. The herbaceous layer was found to be of better circumscriptive value. Communities described (based on dominant herbaceous species) are: (1) Themeda australis – Gonocarpus micranthus, (2) Baumea articulata – Baloskion stenocoleum, (3) Lepidosperma limicola – Baloskion stenocoleum, (4) Baloskion fimbriatum – Lomandra longifolia, (5) Lepyrodia scariosa – Blandfordia grandiflora, (6) Lepidosperma gunnii – Lepidosperma scariosa, (7) Baloskion stenocoleum – Empodisma minus, (8) Lepidosperma limicola – Xyris operculata. The mean annual moisture index was found to account for 26% of the variation in species density. These montane bog systems are some of the richest in Australia, with a high number of rare and restricted taxa. They are vulnerable to both present landuse practices and future changes in climate, are restricted in area, and need further conservation efforts to ensure their long-term survival

Traveling Wave Parametric Amplifier based on a chain of Coupled Asymmetric SQUIDs

A traveling wave parametric amplifier (TWPA) composed of a transmission line made up of a chain of coupled asymmetric superconducting quantum interference devices (SQUIDs) is proposed. The unique nature of this transmission line is that its nonlinearity can be tuned with an external magnetic flux and can even change sign. This feature of the transmission line can be used to perform phase matching in a degenerate four-wave mixing process which can be utilized for parametric amplification of a weak signal in the presence of a strong pump. Numerical simulations of the TWPA design have shown that with tuning, phase matching can be achieved and an exponential gain as a function of the transmission line length can be realized. The flexibility of the proposed design can realize: compact TWPAs with less than 211 unit cells, signal gains greater than 20 dB, 3 dB bandwidth greater than 5.4 GHz, and saturation powers up to -98 dBm. This amplifier design is well suited for multiplexed readout of quantum circuits or astronomical detectors in a compact configuration which can foster on-chip implementations

Anomalies, Chern-Simons Terms and Chiral Delocalization in Extra Dimensions

Gauge invariant topological interactions, such as the D=5 Chern-Simons terms, are required in models in extra dimensions that split anomaly free representations. The Chern-Simons term is necessary to maintain the overall anomaly cancellations of the theory, but it can have significant, observable, physical effects. The CS-term locks the KK-mode parity to the parity of space-time, leaving a single parity symmetry. It leads to new processes amongst KK-modes, eg, the decay of a KK-mode to a 2-body final state of KK-modes. A formalism for the effective interaction amongst KK-modes is constructed, and the decay of a KK-mode to KK-mode plus zero mode is analyzed as an example. We elaborate the general KK-mode current and anomaly structure of these theories. This includes a detailed study of the triangle diagrams and the associated ``consistent anomalies'' for Weyl spinors on the boundary branes. We also develop the non-abelian formalism. We illustrate this by showing in a simple way how a D=5 Yang-Mills ``quark flavor'' symmetry leads to the D=4 chiral lagrangian of mesons and the quantized Wess-Zumino-Witten term.Comment: 51 pages, 3 figures; Corrected typos, amplified discussio

The effect of immigration on the adaptation of microbial communities to warming

Theory predicts that immigration can either enhance or impair the rate at which species and whole communities adapt to environmental change, depending on the traits of genotypes and species in the source pool relative to local conditions. These responses in turn will determine how well whole communities function in changing environments. We tested the effects of immigration and experimental warming on microbial communities during an 81 day field experiment. The effects of immigration depended on the warming treatment. In warmed communities immigration was detrimental to community growth whereas in ambient communities it was beneficial. This result is explained if colonists came from a local species pool pre-adapted to ambient conditions. Loss of metabolic diversity, however, was buffered by immigration in both environments. Communities showed increasing local adaptation to temperature conditions during the experiment and this was independent of whether or not they received immigration. Genotypes that comprised the communities were not locally adapted, however, indicating that community local adaptation can be independent of adaptation of component genotypes. Our results are consistent with a greater role for species interactions rather than adaptation of constituent species in determining local adaptation of whole communities, and confirm that immigration can either enhance or impair community responses to environmental change depending on the environmental context

Enthusing and inspiring with reusable kinaesthetic activities

We describe the experiences of three University projects that use a style of physical, non-computer based activity to enthuse and teach school students computer science concepts. We show that this kind of activity is effective as an outreach and teaching resource even when reused across different age/ability ranges, in lecture and workshop formats and for delivery by different people. We introduce the concept of a Reusable Outreach Object (ROO) that extends Reusable Learning Objects. and argue for a community effort in developing a repository of such objects

Fossil trees, tree moulds and tree casts in the Palaeocene Mull Lava Field, NW Scotland: context, formation and implications for lava emplacement

Megafossils and macrofossils of terrestrial plants (trees, leaves, fruiting bodies, etc.) are found in sedimentary and pyroclastic units interbedded with lavas in many ancient lava fields worldwide, attesting to subaerial environments of eruption and the establishment of viable plant communities during periods of volcanic quiescence. Preservation within lava is relatively rare and generally confined to the more robust woody tissues of trees, which are then revealed in the form of charcoal, mineralised tissue or as trace fossil moulds (tree moulds) and casts of igneous rock (tree casts, s.s.). In this contribution, we document several such fossil trees (s.l.), and the lavas with which they are associated, from the Palaeocene Mull Lava Field (MLF) on the Isle of Mull, NW Scotland. We present the first detailed geological account of a unique site within the Mull Plateau Lava Formation (MPLF) at Quinish in the north of the island and provide an appraisal of the famous upright fossil tree – MacCulloch's Tree – remotely located on the Ardmeanach Peninsula on the west coast of the island, and another large upright tree (the Carsaig Tree) near Malcolm's Point in the district of Brolass, SW Mull; both occurring within the earlier Staffa Lava Formation (SLF). The taphonomy of these megafossils, along with palynological and lithofacies assessments of associated strata, allows speculation of likely taxonomic affinity and the duration of hiatuses supporting the establishment of forest/woodland communities. The Ardmeanach and Carsaig specimens, because of their size and preservation as upright (? in situ) casts enveloped by spectacularly columnar-jointed basaltic lava, appear to be unique. The aspect of these trees, the thickness of the enveloping lavas and the arrangement of cooling joints adjacent to the trees, implies rapid emplacement, ponding and slow, static cooling of voluminous and highly fluid basaltic magma. The specimens from Quinish include two prostrate casts and several prostrate moulds that collectively have a preferred orientation, aligning approximately perpendicular to that of the regional Mull Dyke Swarm, the putative fissure source of the lavas, suggesting local palaeo-flow was directed towards the WSW. The Quinish Lava is an excellent example of a classic pāhoehoe (compound-braided) type, preserving some of the best examples of surface and internal features so far noted from the Hebridean Igneous Province (HIP) lava fields. These Mull megafossils are some of the oldest recorded examples, remarkably well preserved, and form a significant feature of the island's geotourism industry