3,258 research outputs found
Diffusional Relaxation in Random Sequential Deposition
The effect of diffusional relaxation on the random sequential deposition
process is studied in the limit of fast deposition. Expression for the coverage
as a function of time are analytically derived for both the short-time and
long-time regimes. These results are tested and compared with numerical
simulations.Comment: 9 pages + 2 figure
Colonization of the developing rhizosphere of sugar beet seedlings by potential biocontrol agents applied as seed treatments
Aims: Poor colonization of the rhizosphere is a major constraint of seed treatment biological control. The objectives of this study were to; examine the colonization of the rhizosphere of sugar beet seedlings by selected rhizobacteria; determine the influence of the host rhizosphere and percolating water on the distribution of the bacteria; and deliver two biological control agents (BCAs) by co-inoculation. Methods and Results: Rifampicin-resistant bacterial strains (Rif(+)) applied as single treatments to seed sown in columns of field soil produced persistent populations of 5-9 log(10) cfu g(-1) in the infection court of the damping-off pathogen Aphanomyces cochlioides in a controlled environment. However, isolates varied in their ability to colonize the lower rhizosphere. Percolating water significantly increased the colonization of the upper rhizosphere. Bacterial populations in the soil profiles of "non-rhizosphere" controls declined markedly with time. There was no interaction between the two selected BCAs applied as a seed treatment mixture. Conclusions: The distribution of the bacteria resulted primarily from root colonization although percolating water may modify the colonization profiles. Co-inoculation of the sugar-beet rhizosphere is a viable proposition. Significance and Impact of Study: Potential BCAs were successfully delivered to the known infection court of A. cochloides and persisted for the infection period. This bioassay can be used as a tool for the selection of BCAs for field trials
Adolescents care but don't feel responsible for farm animal welfare
Adolescents are the next generation of consumers with the potential to raise standards of farm animal welfareâto theirsatisfactionâif their preferences and concerns are translated into accurate market drivers and signals. There are no published data about adolescent views of farm animal welfare to allow meaningful design, implementation, and evaluation of educational strategies to improve consideration ofâand behavior towardâfarm animals. Knowledge of farm animal welfare, as well as beliefs and attitudes about farm animal welfare and behavioral intention relevant to it were determined in a sample of ukadolescents, using a survey incorporating an extended version of the theory of planned behavior and novel assessment tools. Our results indicate that adolescents have only a limited knowledge of welfare problems for farm animals and welfare-relevant product labels. Intentions to identify welfare standards for the animals from whom their food was derived were weak. Although they cared about farm animal welfare and agreed with fundamental principlesâfor example, the provision of space and the absence of pain and sufferingâlike adults they held limited belief in the power and responsibility that they possess through their choices as consumers; responsibility was often shifted to others, such as the government and farmers
Diagnosis and Correction of Nutritional Disorders in Ginger
This booklet contains descriptions and photographs of symptoms of deficiencies and toxicities of nutrients, including nitrogen, phosphorus, potassium, calcium, magnesium, sulfur, iron, boron, manganese, zinc, copper and molybdenum, and advice on treatment of affected crops
Protocols for optimal readout of qubits using a continuous quantum nondemolition measurement
We study how the spontaneous relaxation of a qubit affects a continuous
quantum non-demolition measurement of the initial state of the qubit. Given
some noisy measurement record , we seek an estimate of whether the qubit
was initially in the ground or excited state. We investigate four different
measurement protocols, three of which use a linear filter (with different
weighting factors) and a fourth which uses a full non-linear filter that gives
the theoretically optimal estimate of the initial state of the qubit. We find
that relaxation of the qubit at rate strongly influences the fidelity
of any measurement protocol. To avoid errors due to this decay, the measurement
must be completed in a time that decrease linearly with the desired fidelity
while maintaining an adequate signal to noise ratio. We find that for the
non-linear filter the predicted fidelity, as expected, is always better than
the linear filters and that the fidelity is a monotone increasing function of
the measurement time. For example, to achieve a fidelity of 90%, the box car
linear filter requires a signal to noise ratio of in a time
whereas the non-linear filter only requires a signal to noise ratio of .Comment: 12 pages, 6 figure
Shining a light on the composition and distribution patterns of mesophotic and subphotic fish communities in Hawaiâi
As agencies shift from single-species management to ecosystem-based fisheries
management, ecosystem models are gaining interest for understanding species dynamics in relation
to oceanographic and ecological processes and human marine uses. However, information on
community structure or distribution of many species that occupy deep (>30 m) waters is largely
unavailable. We amassed a total of 24 686 fish observations of 523 species/taxa for the 30â410 m
depth areas surrounding the main Hawaiian Islands (MHI). We also obtained estimates of geomorphological
variables, including substrate type, slope, rugosity, and ridge-like features. Using these
2 data sources, we (1) identified distinct fish communities along the 30â410 m depth gradient, and
(2) generated relative biomass maps for fish functional groups. We showed that the mesophotic
zone ranges between 30 and 129 m, with a fish faunal break at 60 m. Beyond this zone, 4 subphotic
zones were identified: upper rariphotic (130â169 m), mid-rariphotic (170â239 m), lower rariphotic
(240â319 m), and upper bathyal (320â410 m). We assigned fish species to functional groups partly
based on identified depth ranges and fitted general additive models (GAMs) integrating geomorphological
covariates to the functional group relative biomass estimates to determine the environmental
variables that best predict the probability of encounter and relative biomass of each fish
functional group. Finally, GAM predictions were employed to map functional group relative biomass
distributions. These distribution maps showed a high relative biomass of many groups in the
center of the MHI chain. This study contributes to a better understanding of fish community structure
around the MHI and will inform ecosystem model parameterization
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