Solvable Lattice Gas Models of Random Heteropolymers at Finite Density: II. Dynamics and Transitions to Compact States

In this paper we analyse both the dynamics and the high density physics of the infinite dimensional lattice gas model for random heteropolymers recently introduced in \cite{jort}. Restricting ourselves to site-disordered heteropolymers, we derive exact closed deterministic evolution equations for a suitable set of dynamic order parameters (in the thermodynamic limit), and use these to study the dynamics of the system for different choices of the monomer polarity parameters. We also study the equilibrium properties of the system in the high density limit, which leads to a phase diagram exhibiting transitions between swollen states, compact states, and regions with partial compactification. Our results find excellent verification in numerical simulations, and have a natural and appealing interpretation in terms of real heteropolymers.Comment: 12 pages, 8 eps figures, revised version (to be published in EPJ

Performance evaluation of a combined HiperLAN/2-Bluetooth digital front-end

In our Software-Defined-Radio (SDR) project we aim to combine two receivers (HiperLAN/2 and Bluetooth) on one common platform. In this paper, the main focus is on one of the performance bottlenecks of such a receiver, namely the bandpass filter section in Bluetooth mode. Contributions of inter-symbol interference ISI, adjacent channel interference ACI and noise on the total bit error rate BER are analyzed. The influence of the channel selection filter characteristics on these contributions are researched. Larger values for (for instance) transition bandwidth result in lower order filters that reduce the computational load, which is an important design consideration. This also reduces bit errors caused by ISI, one of the two major contributors to the total BER. On the other hand, lower order filters increase the BER due to ACI. Optimal filter parameters are derived from these trade-offs and applied the system which will be presented

Belichtingsstrategieen bij potplanten

Assimilatiebelichting wordt al een aantal jaren bij potplanten toegepast. Uit onderzoeken, waarbij de invloed van diverse belichtingsduren en -intensiteiten op de groei en bloei van potplanten is onderzocht, is gebleken dat gewassen zeer specifiek hierop kunnen reageren. Daarnaast bleek ook de periode van toepassing (najaar, winter of voorjaar) invloed te hebben op het resultaat. Zowel plantkundig als economisch is het van belang te weten bij welk belichtingsregime potplanten optimaal groeien. Bij de teelt van potplanten speelt daarin de planbaarheid een belangrijke rol. De hoeveelheid licht kan in de winter sterk variëren. Mogelijk kan door de belichting te regelen op basis van lichtsommen (natuurlijk licht plus kunstlicht) een verkorte, homogene en meer planmatige teelt van kwalitatief goede planten bereikt worden. Het regelen op lichtsommen houdt in dat op lichte dagen, dagen met een hoge natuurlijke lichtsom, volstaan kan worden met weinig assimilatielicht. Op donkere dagen zal dan veel assimilatielicht gegeven moeten worden. Bij onderzoek aan het gewas Freesia (LUW en PBG-Naaldwijk) is gebleken dat optimaliseren middels lichtsommen het meeste perspectief biedt bij dat gewas

Cluster derivation of Parisi's RSB solution for disordered systems

We propose a general scheme in which disordered systems are allowed to sacrifice energy equi-partitioning and separate into a hierarchy of ergodic sub-systems (clusters) with different characteristic time-scales and temperatures. The details of the break-up follow from the requirement of stationarity of the entropy of the slower cluster, at every level in the hierarchy. We apply our ideas to the Sherrington-Kirkpatrick model, and show how the Parisi solution can be {\it derived} quantitatively from plausible physical principles. Our approach gives new insight into the physics behind Parisi's solution and its relations with other theories, numerical experiments, and short range models.Comment: 7 pages 5 figure

Integrated control of Striga hermonthica (Del.) Benth. in Burkina Faso through host plant resistance, biocontrol and fertilizers

A two-year field study investigated integrated management of Striga hermonthica on sorghum through host crop resistance, biocontrol (Fusarium oxysporum isolate 34-FO), and fertilizer application. The experiment was conducted in a field with natural Striga infestation at Kouaré Research Station in Fada N’Gourma, Burkina Faso. Treatments combining sorghum resistance with Fusarium inoculum and N-fertilizer or manure significantly reduced emerged Striga plant number, plant vigour and dry biomass of Striga and the area under the Striga number progress curve (ASNPC) in 2002, as compared to the control. Integrated Striga Management (ISM) plots fertilized with urea, urea plus growth medium or urea plus manure associated with Fusarium inoculum resulted in improved sorghum grain yield of at least 15% in 2001 and of at least 97% in 2002. Economic analysis showed that the combination of sorghum resistance with fungal inoculum or urea at 200 kg ha-1 allowed for a significant financial profit in sorghum production. The results suggest that to reduce Striga infestation below economic threshold, ISM treatments should be consistently applied for several years without expecting very high returns.Keywords: Striga hermonthica, integrated control, Fusarium inoculum, Sorghum resistance, fertilization, Burkina Fas