High-power microwave radiation as an alternative insect control method for stored products.

ABSTRACT Insect mortality studies were performed with a high-power microwave source operating at a frequency of 10.6 GHz at power levels of 9-20 kW to irradiate samples of soft wite wheat, Triticum aestivum (L.), infested with maize weevil, Sitophilus zeamais Motschul-sky, and ground wheat infested with red flour beetle, Tribolium castaneum (Herbst). These pests are common internal and external feeders in stored products, respectively. Samples at various age intervals from egg to adult were exposed. The results support the hypothesis that the insect-to-host dissipation ratio increases at frequencies >2.45 GHz. Mean mortalities 93% occurred for all ages of S. zeamais and 94% for adults and larvae of T. castaneum for mean specific input energies of 51 J/g and 53 J/g, respectively, indicating that S. zeamais is more susceptible. Extrapolating the results to the cost of treating the product in bulk volume at a busbar electric energy cost of $0.05 per kW-h (3,600 kJ) indicates a unit cost for electric energy ranging only from$0.056 per bushel of wheat infested with S. zeamais to $0.139 per hundred weight of ground wheat infested with T. castuneum

Space-time versus particle-hole symmetry in quantum Enskog equations

The non-local scattering-in and -out integrals of the Enskog equation have reversed displacements of colliding particles reflecting that the -in and -out processes are conjugated by the space and time inversions. Generalisations of the Enskog equation to Fermi liquid systems are hindered by a request of the particle-hole symmetry which contradicts the reversed displacements. We resolve this problem with the help of the optical theorem. It is found that space-time and particle-hole symmetry can only be fulfilled simultaneously for the Bruckner-type of internal Pauli-blocking while the Feynman-Galitskii form allows only for particle-hole symmetry but not for space-time symmetry due to a stimulated emission of Bosons

Kinetic Properties of a Bose-Einstein Gas at Finite Temperature

We study, in the framework of the Boltzmann-Nordheim equation (BNE), the kinetic properties of a boson gas above the Bose-Einstein transition temperature $T_c$. The BNE is solved numerically within a new algorithm, that has been tested with exact analytical results for the collision rate of an homogeneous system in thermal equilibrium. In the classical regime ($T > 6~ T_c$), the relaxation time of a quadrupolar deformation in momentum space is proportional to the mean free collision time $\tau_{relax} \sim T^{-1/2}$. Approaching the critical temperature ($T_c < T < 2.7~ T_c$), quantum statistic effects in BNE become dominant, and the collision rate increases dramatically. Nevertheless, this does not affect the relaxation properties of the gas that depend only on the spontaneous collision term in BNE. The relaxation time $\tau_{relax}$ is proportional to $(T - T_c)^{-1/2}$, exhibiting a critical slowing down. These phenomena can be experimentally confirmed looking at the damping properties of collective motions induced on trapped atoms. The possibility to observe a transition from collisionless (zero-sound) to hydrodynamic (first-sound) is finally discussed.Comment: RevTeX, 5 figures. Submitted to Phys. Rev.

Quantum Kinetic Theory I: A Quantum Kinetic Master Equation for Condensation of a weakly interacting Bose gas without a trapping potential

A Quantum Kinetic Master Equation (QKME) for bosonic atoms is formulated. It is a quantum stochastic equation for the kinetics of a dilute quantum Bose gas, and describes the behavior and formation of Bose condensation. The key assumption in deriving the QKME is a Markov approximation for the atomic collision terms. In the present paper the basic structure of the theory is developed, and approximations are stated and justified to delineate the region of validity of the theory. Limiting cases of the QKME include the Quantum Boltzmann master equation and the Uehling-Uhlenbeck equation, as well as an equation analogous to the Gross-Pitaevskii equation.Comment: 37 pages, 4 figure

Patterns of Diversity in Soft-Bodied Meiofauna: Dispersal Ability and Body Size Matter

Background: Biogeographical and macroecological principles are derived from patterns of distribution in large organisms, whereas microscopic ones have often been considered uninteresting, because of their supposed wide distribution. Here, after reporting the results of an intensive faunistic survey of marine microscopic animals (meiofauna) in Northern Sardinia, we test for the effect of body size, dispersal ability, and habitat features on the patterns of distribution of several groups.Methodology/Principal Findings: As a dataset we use the results of a workshop held at La Maddalena (Sardinia, Italy) in September 2010, aimed at studying selected taxa of soft-bodied meiofauna (Acoela, Annelida, Gastrotricha, Nemertodermatida, Platyhelminthes and Rotifera), in conjunction with data on the same taxa obtained during a previous workshop hosted at Tjärnö (Western Sweden) in September 2007. Using linear mixed effects models and model averaging while accounting for sampling bias and potential pseudoreplication, we found evidence that: (1) meiofaunal groups with more restricted distribution are the ones with low dispersal potential; (2) meiofaunal groups with higher probability of finding new species for science are the ones with low dispersal potential; (3) the proportion of the global species pool of each meiofaunal group present in each area at the regional scale is negatively related to body size, and positively related to their occurrence in the endobenthic habitat.Conclusion/Significance: Our macroecological analysis of meiofauna, in the framework of the ubiquity hypothesis for microscopic organisms, indicates that not only body size but mostly dispersal ability and also occurrence in the endobenthic habitat are important correlates of diversity for these understudied animals, with different importance at different spatial scales. Furthermore, since the Western Mediterranean is one of the best-studied areas in the world, the large number of undescribed species (37%) highlights that the census of marine meiofauna is still very far from being complete

Gene and genon concept: coding versus regulation: A conceptual and information-theoretic analysis of genetic storage and expression in the light of modern molecular biology

We analyse here the definition of the gene in order to distinguish, on the basis of modern insight in molecular biology, what the gene is coding for, namely a specific polypeptide, and how its expression is realized and controlled. Before the coding role of the DNA was discovered, a gene was identified with a specific phenotypic trait, from Mendel through Morgan up to Benzer. Subsequently, however, molecular biologists ventured to define a gene at the level of the DNA sequence in terms of coding. As is becoming ever more evident, the relations between information stored at DNA level and functional products are very intricate, and the regulatory aspects are as important and essential as the information coding for products. This approach led, thus, to a conceptual hybrid that confused coding, regulation and functional aspects. In this essay, we develop a definition of the gene that once again starts from the functional aspect. A cellular function can be represented by a polypeptide or an RNA. In the case of the polypeptide, its biochemical identity is determined by the mRNA prior to translation, and that is where we locate the gene. The steps from specific, but possibly separated sequence fragments at DNA level to that final mRNA then can be analysed in terms of regulation. For that purpose, we coin the new term “genon”. In that manner, we can clearly separate product and regulative information while keeping the fundamental relation between coding and function without the need to introduce a conceptual hybrid. In mRNA, the program regulating the expression of a gene is superimposed onto and added to the coding sequence in cis - we call it the genon. The complementary external control of a given mRNA by trans-acting factors is incorporated in its transgenon. A consequence of this definition is that, in eukaryotes, the gene is, in most cases, not yet present at DNA level. Rather, it is assembled by RNA processing, including differential splicing, from various pieces, as steered by the genon. It emerges finally as an uninterrupted nucleic acid sequence at mRNA level just prior to translation, in faithful correspondence with the amino acid sequence to be produced as a polypeptide. After translation, the genon has fulfilled its role and expires. The distinction between the protein coding information as materialised in the final polypeptide and the processing information represented by the genon allows us to set up a new information theoretic scheme. The standard sequence information determined by the genetic code expresses the relation between coding sequence and product. Backward analysis asks from which coding region in the DNA a given polypeptide originates. The (more interesting) forward analysis asks in how many polypeptides of how many different types a given DNA segment is expressed. This concerns the control of the expression process for which we have introduced the genon concept. Thus, the information theoretic analysis can capture the complementary aspects of coding and regulation, of gene and genon

Life History of Innnature \u3ci\u3eLyctocoris campestris\u3c/i\u3e (Hemiptera: Anthocoridae): Effects of Constant Temperatures and Relative Humidities

Life history of immature Lyctocoris campestris (F.), a predator of stored-product insects, was investigated at 17, 21, 25, and 29°C and =43, =58, and =75% RH in the laboratory. Most life history traits of L. campestris were influenced by temperature, but none of the traits was influenced by relative humidity. The egg incubation period was =7 d at 25- 29°C, but increased sharply at temperatures \u3c25°C. An equation was developed to predict egg incubation period over a range of temperatures. Egg hatch rate did not vary with temperatures nor with the relative humidities. The mean hatch rate ranged from 78 to 86% across different temperatures summed across 3 relative humidities. The instar-specific nymphal development also varied with temperature. The 2nd stadium was the shortest followed by the 3rd, 1st, and the 4th, and the 5th stadium was the longest across all 4 temperatures. However, the ratios of duration of nymphal stadia remained constant across all 4 temperatures tested. Total nymphal durations were 20.5, 27.6, 40.1, and 66.2 d at 29,25,21, and 1~C, respectively; all 4 were significantly different from one another. The relationships between temperature and instar-specific nymphal durations and total nymphal durations were described by the same equation for both females and males; total nymphal durations did not vary with sex. Nymphal survival rates ranged from 0.60 to 1.00 and did not vary significantly with temperature or relative humidity. Sex ratio (proportion of males) of emerging adults ranged from 0.40 to 0.70, but did not differ from 1:1. These life history data are reported in a manner useful for developing a computer model for simulating L. campestris population dynamics