The importance of clean dwellings

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Analysis of the chargino and neutralino mass parameters at one-loop level

In the Minimal Supersymmetric Standard Model (MSSM) the masses of the neutralinos and charginos depend on the gaugino and higgsino mass parameters M, M' and $\mu$. If supersymmetry is realized, the extraction of these parameters from future high energy experiments will be crucial to test the underlying theory. We present a consistent method how on-shell parameters can be properly defined at one-loop level and how they can be determined from precision measurements. In addition, we show how a GUT relation for the parameters M and M' can be tested at one-loop level. The numerical analysis is based on a complete one-loop calculation. The derived analytic formulae are given in the appendix.Comment: 16 pages, 8 figure

A new record of Percursaria percursa (Ulvaceae, Ulvales) on the North Island, New Zealand

The filamentous green alga Percursaria percursa (Ulvaceae, Ulvales) was recorded for the first time on the North Island of New Zealand at mokoroa Estuary, Tauranga Harbour. This species is previously known within New Zealand from only two records, both from the South Island. In Tauranga Harbour, this species was restricted to anoxic estuarine sediments where mangrove forests had been mulched, and mulchate left in situ. Percursaria percursa was found intertwined with Ulva spp. and Rhizoclonium spp. Surveys of other North and South Island estuaries suggest that this alga, although occurring as part of nuisance green algal blooms in Tauranga Harbour, has only colonized human-impacted locations, and has not yet been observed in natural' estuarine ecosystems in New Zealand. As this species was found intertwined with other mat-forming filamentous green algae, it can easily be misidentified in the field, leading to both over- and under-reporting of species occurrence

Navigation/traffic control satellite mission study. Volume 3 - System concepts

Satellite network for air traffic control, solar flare warning, and collision avoidanc

The contribution of energy efficiency towards the success of industrial organisations in South Africa

The original publication is available at http://sajie.journals.ac.zaENGLISH ABSTRACT: Internationally, governments and lobby groups increasingly put pressure on organisations to reduce their impact on the environment. To this end, various studies show the drivers, barriers, and contributions of energy efficiency towards a more sustainable environment, particularly through reduced greenhouse gas emissions and other by-products. In the study summarised in this paper, the factors that drive organisational success were compared with the effects that energy efficiency projects have on organisations. Methods, policies, and strategies on the application of energy efficiency were also studied. The findings are that, in general, most organisations have energy efficiency policies and strategies in place, and they include internal and external stakeholders in their energy efficiency efforts. These efforts also show a positive correlation with the factors that contribute to the perceived success of organisations in the South African industrial sector. These strategies must be maintained in the longer term, as energy efficiency will play a more important role in the future.AFRIKAANSE OPSOMMING: Organisasies, wêreldwyd, word toenemend onder druk geplaas deur regerings- en aksiegroepe om hul impak op die omgewing te verminder. Na aanleiding hiervan toon verskeie studies die drywers, struikelblokke en bydraes van energie-doeltreffendheid na ʼn meer volhoubare omgewing, veral ten opsigte van groenhuisgas-emissies en ander neweprodukte. In hierdie studie is die faktore wat die sukses van organisasies dryf vergelyk met die effek van die toepassing van energiedoeltreffendheidsprojekte op organisasies. Metodes, beleid en strategieë in terme van die toepassing van energiedoeltreffendheid is ook bestudeer. Die bevindinge is dat die meeste organisasies, oor die algemeen, beleid en strategieë in plek het in terme van energiedoeltreffendheid; dié organisasies sluit interne en eksterne belanghebbendes in waar hulle strewe na energiedoeltreffendheid. Hierdie aktiwiteite toon ʼn positiewe korrelasie met die faktore wat waarde bydra ten opsigte van die oënskynlike sukses van organisasies in die Suid-Afrikaanse industriële sektor. Dus moet hierdie strategieë in plek gehou word in die langtermyn, aangesien energiedoeltreffendheid ʼn belangriker rol sal speel in die toekoms

Wireless recording of the calls of Rousettus aegyptiacus and their reproduction using electrostatic transducers

Bats are capable of imaging their surroundings in great detail using echolocation. To apply similar methods to human engineering systems requires the capability to measure and recreate the signals used, and to understand the processing applied to returning echoes. In this work, the emitted and reflected echolocation signals of Rousettus aegyptiacus are recorded while the bat is in flight, using a wireless sensor mounted on the bat. The sensor is designed to replicate the acoustic gain control which bats are known to use, applying a gain to returning echoes that is dependent on the incurred time delay. Employing this technique allows emitted and reflected echolocation calls, which have a wide dynamic range, to be recorded. The recorded echoes demonstrate the complexity of environment reconstruction using echolocation. The sensor is also used to make accurate recordings of the emitted calls, and these calls are recreated in the laboratory using custom-built wideband electrostatic transducers, allied with a spectral equalization technique. This technique is further demonstrated by recreating multi-harmonic bioinspired FM chirps. The ability to record and accurately synthesize echolocation calls enables the exploitation of biological signals in human engineering systems for sonar, materials characterization and imaging

Soleus stretch reflex during cycling

The modulation and strength of the human soleus short latency stretch reflex was investigated by mechanically perturbing the ankle during an unconstrained pedaling task. Eight subjects pedaled at 60 rpm against a preload of 10 Nm. A torque pulse was applied to the crank at various positions during the crank cycle, producing ankle dorsiflexion perturbations of similar trajectory. The stretch reflex was greatest during the power phase of the crank cycle and was decreased to the level of background EMG during recovery. Matched perturbations were induced under static conditions at the same crank angle and background soleus EMG as recorded during the power phase of active pedaling. The magnitude of the stretch reflex was not statistically different from that during the static condition throughout the power phase of the movement. The results of this study indicate that the stretch reflex is not depressed during active cycling as has been shown with the H-reflex. This lack of depression may reflect a decreased susceptibility of the stretch reflex to inhibition, possibly originating from presynaptic mechanisms

On the validity of mean-field amplitude equations for counterpropagating wavetrains

We rigorously establish the validity of the equations describing the evolution of one-dimensional long wavelength modulations of counterpropagating wavetrains for a hyperbolic model equation, namely the sine-Gordon equation. We consider both periodic amplitude functions and localized wavepackets. For the localized case, the wavetrains are completely decoupled at leading order, while in the periodic case the amplitude equations take the form of mean-field (nonlocal) Schr\"odinger equations rather than locally coupled partial differential equations. The origin of this weakened coupling is traced to a hidden translation symmetry in the linear problem, which is related to the existence of a characteristic frame traveling at the group velocity of each wavetrain. It is proved that solutions to the amplitude equations dominate the dynamics of the governing equations on asymptotically long time scales. While the details of the discussion are restricted to the class of model equations having a leading cubic nonlinearity, the results strongly indicate that mean-field evolution equations are generic for bimodal disturbances in dispersive systems with \O(1) group velocity.Comment: 16 pages, uuencoded, tar-compressed Postscript fil

An Exact Algorithm for Side-Chain Placement in Protein Design

Computational protein design aims at constructing novel or improved functions on the structure of a given protein backbone and has important applications in the pharmaceutical and biotechnical industry. The underlying combinatorial side-chain placement problem consists of choosing a side-chain placement for each residue position such that the resulting overall energy is minimum. The choice of the side-chain then also determines the amino acid for this position. Many algorithms for this NP-hard problem have been proposed in the context of homology modeling, which, however, reach their limits when faced with large protein design instances. In this paper, we propose a new exact method for the side-chain placement problem that works well even for large instance sizes as they appear in protein design. Our main contribution is a dedicated branch-and-bound algorithm that combines tight upper and lower bounds resulting from a novel Lagrangian relaxation approach for side-chain placement. Our experimental results show that our method outperforms alternative state-of-the art exact approaches and makes it possible to optimally solve large protein design instances routinely