Molecular Mapping of Male-Sterility Loci ms2 and ms9 in Soybean

Markers linked to male-sterile, female-fertile loci on the soybean [Glycine max (L.) Merr.] molecular map would facilitate early identification of male-sterile plants. The objectives were to verify the chromosome location of the ms2 (A00–63) mutation, to determine the allelism and the chromosome location of the suspected ms2 [ms? (A00–39)] mutation, and to determine the chromosome location of the ms9 (T359) mutation. Simple sequence repeat (SSR) markers were used to molecularly map the male-sterile, female-fertile loci reported in this study. Segregating F2 populations were developed from crosses of ms?ms? (A00–39) × ‘Minsoy’ (PI 278901), ms2ms2 (A00–63) × Minsoy, and Minsoy × Ms9ms9 (T359H). The ms?(A00–39) locus was positioned on MLG O at 9.9 centiMorgans (cM) distance from the marker Sat_190. The ms2 (A00–63) locus was positioned on molecular linkage group (MLG) O between markers Sat_190 and Scaa001, with a distance of 6.9 and 9.0 cM, respectively. Thems9 locus was located on MLG N between markers Satt521 and Satt237, with a distance of 8.5 and 16.2 cM, respectively. Classical allelism tests confirmed that mutant ms? (A00–39) was allelic to ms2 (A00–63). The A00–39 mutant line was assigned Genetic Type Collection number T375H and gene symbol Ms2ms2 (Ames 2). Thus Genetic Type T360H, previously identified at Ames, Iowa, becomes Ms2ms2 (Ames 1)

Spin-glass model with partially annealed asymmetric bonds

We have considered the two-spin interaction spherical spin-glass model with asymmetric bonds (coupling constants). Besides the usual interactions between spins and bonds and between the spins and a thermostat with temperature $T_{\sigma}$ there is also an additional factor: the bonds are not assumed random {\it a priori} but interact with some other thermostat at the temperature $T_{J}$. We show that when the bonds are frozen with respect to the spins a first order phase transition to a spin-glass phase occurs, and the temperature of this transition tends to zero if $T_J$ is large. Our analytical results show that a spin-glass phase can exist in mean-field models with nonrelaxational dynamics.Comment: 10 pages, late

Advanced Composite Solar Sail System: Demonstrating Deployable Composite Solar Sails for Future Deep Space Small Spacecraft

NASA is developing new deployable structures and materials technologies for solar sail propulsion systems destined for future low-cost deep space missions. Solar sails eliminate the need for conventional rocket propellants, relying instead upon the pressure of sunlight to generate continuous thrust. They can operate indefinitely, limited only by the space environment durability of the solar sail materials and spacecraft electronic systems.At NASA's Langley Research Center in Hampton, Virginia, and NASA's Ames Research Center in California's Silicon Valley, researchers and engineers are planning a mission to demonstrate the next generation of solar sail technology for small interplanetary spacecraft. As part of this development effort, the Advanced Composite Solar Sail System (ACS3) will demonstrate deployment of an approximately 800 square foot (74 square meter) composite boom (mast) solar sail system in low-Earth orbit. This will be the first use of composite booms as well as sail packing and deployment systems for a solar sail in orbit

Dynamics of on-line Hebbian learning with structurally unrealizable restricted training sets

We present an exact solution for the dynamics of on-line Hebbian learning in neural networks, with restricted and unrealizable training sets. In contrast to other studies on learning with restricted training sets, unrealizability is here caused by structural mismatch, rather than data noise: the teacher machine is a perceptron with a reversed wedge-type transfer function, while the student machine is a perceptron with a sigmoidal transfer function. We calculate the glassy dynamics of the macroscopic performance measures, training error and generalization error, and the (non-Gaussian) student field distribution. Our results, which find excellent confirmation in numerical simulations, provide a new benchmark test for general formalisms with which to study unrealizable learning processes with restricted training sets.Comment: 7 pages including 3 figures, using IOP latex2e preprint class fil

Application of two-parameter dynamical replica theory to retrieval dynamics of associative memory with non-monotonic neurons

The two-parameter dynamical replica theory (2-DRT) is applied to investigate retrieval properties of non-monotonic associative memory, a model which lacks thermodynamic potential functions. 2-DRT reproduces dynamical properties of the model quite well, including the capacity and basin of attraction. Superretrieval state is also discussed in the framework of 2-DRT. The local stability condition of the superretrieval state is given, which provides a better estimate of the region in which superretrieval is observed experimentally than the self-consistent signal-to-noise analysis (SCSNA) does.Comment: 16 pages, 19 postscript figure

A systematic review of the energy and climate impacts of teleworking

Information and communication technologies (ICTs) increasingly enable employees to work from home and other locations (‘teleworking’). This study explores the extent to which teleworking reduces the need to travel to work and the consequent impacts on economy-wide energy consumption. Methods/Design: The paper provides a systematic review of the current state of knowledge of the energy impacts of teleworking. This includes the energy savings from reduced commuter travel and the indirect impacts on energy consumption associated with changes in non-work travel and home energy consumption. The aim is to identify the conditions under which teleworking leads to a net reduction in economy-wide energy consumption, and the circumstances where benefits may be outweighed by unintended impacts. The paper synthesises the results of 39 empirical studies, identified through a comprehensive search of 9,000 published articles. Review results/Synthesis: Twenty six of the 39 studies suggest that teleworking reduces energy use, and only eight studies suggest that teleworking increases, or has a neutral impact on energy use. However, differences in the methodology, scope and assumptions of the different studies make it difficult to estimate ‘average’ energy savings. The main source of savings is the reduced distance travelled for commuting, potentially with an additional contribution from lower office energy consumption. However, the more rigorous studies that include a wider range of impacts (e.g. non-work travel or home energy use) generally find smaller savings. Discussion: Despite the generally positive verdict on teleworking as an energy-saving practice, there are numerous uncertainties and ambiguities about its actual or potential benefits. These relate to the extent to which teleworking may lead to unpredictable increases in non-work travel and home energy use that may outweigh the gains from reduced work travel. The available evidence suggests that economy-wide energy savings are typically modest, and in many circumstances could be negative or non-existent

Dinosaur tracks from the Kilmaluag Formation (Bathonian, Middle Jurassic) of Score Bay, Isle of Skye, Scotland, UK

Tracks of a juvenile theropod dinosaur with footprint lengths of between 2 and 9 cm as well as adults of the same ichnospecies with footprints of about 15–25 cm in length were found in the Bathonian (Middle Jurassic) Kilmaluag Formation of Score Bay, northwestern Trotternish Peninsula, Isle of Skye, Scotland, UK. Two footprint sizes occur together on the same bedding plane in the central portion of Score Bay, both in situ and on loose blocks. Another horizon containing footprints above this was also identified. The footprints from the lowest horizon were produced in a desiccated silty mud that was covered with sand. A close association of both adults and juveniles with similar travel direction indicated by the footprints may suggest post-hatching care in theropod dinosaurs. Other footprints, produced on a rippled sandy substrate, have been found on the slightly higher bedding plane at this locality. Loose blocks found 130 m to the northeast in the central part of Score Bay have not been correlated with any in situ sediments, but were preserved in a similar manner to those from the higher bedding plane. These tracks represent the youngest dinosaur remains yet found in Scotland

On the Out of Equilibrium Relaxation of the Sherrington - Kirkpatrick model

We derive analytical results for the large-time relaxation of the Sherrington - Kirkpatrick model in the thermodynamic limit, starting from a random configuration. The system never achieves local equilibrium in any fixed sector of phase-space, but remains in an asymptotic out of equilibrium regime. We propose as a tool, both numerical and analytical, for the study of the out of equilibrium dynamics of spin-glass models the use of `triangle relations' which describe the geometry of the configurations at three (long) different times.Comment: 42 Pages + 3 Figures upon reques

Phase space geometry and slow dynamics

We describe a non-Arrhenius mechanism for slowing down of dynamics that is inherent to the high dimensionality of the phase space. We show that such a mechanism is at work both in a family of mean-field spin-glass models without any domain structure and in the case of ferromagnetic domain growth. The marginality of spin-glass dynamics, as well as the existence of a `quasi equilibrium regime' can be understood within this scenario. We discuss the question of ergodicity in an out-of equilibrium situation.Comment: 23 pages, ReVTeX3.0, 6 uuencoded postscript figures appende

Relationship between spatial proximity and travel-to-work distance : the effect of the compact city

In this paper, an assessment is made of the relationship between selected aspects of spatial proximity (density, diversity, minimum commuting distance, jobs-housing balance and job accessibility) and reported commuting distances in Flanders (Belgium). Results show that correlations may depend on the considered trip end. For example, a high residential density, a high degree of spatial diversity and a high level of job accessibility are all associated with a short commute by residents, while a high job density is associated with a long commute by employees. A jobs-housing balance close to one is associated with a short commute, both by residents and by employees. In general, it appears that the alleged sustainability benefits of the compact city model are still valid in a context of continuously expanding commuting trip lengths