Shot noise in semiclassical chaotic cavities

We construct a trajectory-based semiclassical theory of shot noise in clean chaotic cavities. In the universal regime of vanishing Ehrenfest time \tE, we reproduce the random matrix theory result, and show that the Fano factor is exponentially suppressed as \tE increases. We demonstrate how our theory preserves the unitarity of the scattering matrix even in the regime of finite \tE. We discuss the range of validity of our semiclassical approach and point out subtleties relevant to the recent semiclassical treatment of shot noise in the universal regime by Braun et al. [cond-mat/0511292].Comment: Final version, to appear in Physical Review Letter

The Possible Effects of Deleterious Rhizobacterial Combinations on the Growth of the Weed Velvetleaf

The use of biological agents in the control of the invasive weed velvetleaf Abutilon theophrasti is attractive due to this weeds development of herbicide resistance. One option is the utilization of deleterious rhizobacteria with amendments to optimize their effectiveness. Indole acetic acid (IAA)- producing Rhizobium rubi (AT3-4RS/6 (RS) and cyanogenic Pseudomonas putida ATH2-1RI/9 (RI) were used to inoculate soil with and without amino acid amendments. RS & tryptophan (a precursor of IAA synthesis) caused the least velvetleaf shoot growth. All roots were colonized by rhizobacteria, on average, 1.40E+10 CFU/ gram of dry root

Tail asymptotics for processor sharing queues

The basic queueing system considered in this paper is the M/G/1 processor-sharing queue with or without impatience and with finite or infinite capacity. Under some mild assumptions, a criterion for the validity of the reduced-service-rate approximation is established when service times are heavy tailed. This result is applied to various models based on M/G/1 processor-sharing queues

Controlling the Sign of Magnetoconductance in Andreev Quantum Dots

We construct a theory of coherent transport through a ballistic quantum dot coupled to a superconductor. We show that the leading-order quantum correction to the two-terminal conductance of these Andreev quantum dots may change sign depending on (i) the number of channels carried by the normal leads or (ii) the magnetic flux threading the dot. In contrast, spin-orbit interaction may affect the magnitude of the correction, but not always its sign. Experimental signatures of the effect include a non-monotonic magnetoconductance curve and a transition from an insulator-like to a metal-like temperature dependence of the conductance. Our results are applicable to ballistic or disordered dots.Comment: Final version (4pages 3figs)- improved presentation and fig 3, and updated reference

Recurrence of bipolar disorders andmajor depression: A life-longperspective

Abstract.: Objective: : It is not known whether the risk of recurrence declines with time in bipolar disorders and in major depression. This study describes the life-long recurrence risk of bipolar I, bipolar II and major depressive disorders. Method: : 160 bipolar-I, 60 bipolar-II and 186 depressive patients hospitalised between 1959 and 1963 were followed up every five years from 1965 to 1985. The course prior to the index hospitalisation was assessed in retrospect. The recurrence risk was computed by the multiplicative intensity model (Aalen et al. 1980). Results: : The cumulative intensity curves for the transition from states of remission to new episodes remained linear over 30 to 40 years after onset, indicating a constant risk of recurrence over the life-span up to the age of 70 or more. The recurrence risk of bipolar disorders (0.40 episodes per year) was about twice that of depression (0.20 episodes per year); BP-II disorders had only a slightly higher recurrence risk than BP-I disorders. There were no significant gender differences in the course of either bipolar or depressive disorders. Conclusion: : If long-term trials confirm its efficacy, these results support lifelong prophylactic treatment of severe types of mood disorder