In this paper, we are concerned with the detection and tracking of a target in TBD context. We propose here an efficient particle filter based on a relevant proposal density justified by radar detection considerations. This filter performs well compared to the classical laws used in the literature, especially in terms of speed of convergence for detection. We also identify a minimum number of p...

We study 6,686 IPOs spanning the period 1981-2005 and find that the new issues puzzle disappears in a Fama-French three-factor framework. IPOs do not underperform in the aftermarket on a risk-adjusted basis and do not underperform a matched sample of non-issuers. IPO underperformance is concentrated in the 1980’s and early 1990’s, and IPO’s either perform the same as the market, or outperform o...

We show that a one-sector real business cycle model with mild increasing returns-toscale and variable capital utilization is able to produce qualitatively realistic business cycles driven solely by aggregate demand shocks. In particular, a positive government spending shock can lead to simultaneous increases in output, consumption, investment, employment, labor productivity and the real wage. O...

Warm temperature promotes flowering in Arabidopsis thaliana and this response involves multiple signalling pathways. To understand the temporal dynamics of temperature perception, tests were carried out to determine if there was a daily window of enhanced sensitivity to warm temperature (28 °C). Warm temperature applied during daytime, night-time, or continuously elicited earlier flowering, but...

Phenological changes among plants due to climate change are well documented, but often hard to interpret. In order to assess the adaptive value of observed changes, we study how annual plants with and without growth constraints should optimize their flowering time when productivity and season length changes. We consider growth constraints that depend on the plant's vegetative mass: self-shading...

Winter-annual ecotypes of Arabidopsis are relatively late flowering, unless the flowering of these ecotypes is promoted by exposure to cold (vernalization). This vernalization-suppressible, late-flowering phenotype results from the presence of dominant, late-flowering alleles at two loci, FRIGIDA (FRI) and FLOWERING LOCUS C (FLC). In this study, we report that flc null mutations result in early...

Flowering at the appropriate time of year is essential for successful reproduction in plants. We found that HAP3b in Arabidopsis (Arabidopsis thaliana), a putative CCAAT-binding transcription factor gene, is involved in controlling flowering time. Overexpression of HAP3b promotes early flowering while hap3b, a null mutant of HAP3b, is delayed in flowering under a long-day photoperiod. Under sho...

Higher plants exhibit a variety of different life histories. Annual plants live for less than a year and after flowering produce seeds and senesce. By contrast perennials live for many years, dividing their life cycle into episodes of vegetative growth and flowering. Environmental cues control key check points in both life histories. Genes controlling responses to these cues exhibit natural gen...

to determine effects of phenyl-phethalamate acid on yield and yield components of tomato, cucumber, eggplant and cabbage, this experiment was investigated in a randomized complete block design with three replications in the spring and summer of 2010. treatments included the time and number of foliar spraying with phenyl-phethalamate acid (1000 ppm). control plants were not sprayed. the first st...

background & aim: thyme is common named thymus vulgaris l. belongs to lamiaceae family. thyme is a most important medicinal plant that was used in pharmaceutical, food, cosmetics hygienic industries in most of developed countries. experimental: determine optimum of harvest time this plant was done in a random block design with three replications was conducted in field islamic azad universi...