Biochemical and behavioral evidence foe hybridization between fire ants,Solenopsis invicta andSolenopsis richteri (Hymenoptera: Formicidae)

Behavioral and biochemical evidence is presented for hybridization between the fire ants,Solenopsis richteri andS. invicta. The response of the two species to extracts of their trail pheromones presented as a point source is clearly species-specific; however, hybrid workers responded to parental Dufour's gland extracts and parental workers responded to Dufour's gland extracts of the hybrid. The behavioral evidence for hybridization was confirmed by gas Chromatograph comparison of the Dufour's gland extracts of the three fire ant forms, which showed a pattern for the hybrid that was intermediate to the two parental species.     

Plug-in Selection of the Number of Frequencies in Regression Estimates of the Memory Parameter of a Long-memory Time Series

We consider the problem of selecting the number of frequencies, m , in a log-periodogram regression estimator of the memory parameter d of a Gaussian long-memory time series. It is known that under certain conditions the optimal m , minimizing the mean squared error of the corresponding estimator of d , is given by m ^(opt)= Cn ^4/5, where n is the sample size and C is a constant. In practice, C would be unknown since it depends on the properties of the spectral density near zero frequency. In this paper, we propose an estimator of C based again on a log-periodogram regression and derive its consistency. We also derive an asymptotically valid confidence interval for d when the number of frequencies used in the regression is deterministic and proportional to n ^4/5. In this case, squared bias cannot be neglected since it is of the same order as the variance. In a Monte Carlo study, we examine the performance of the plug-in estimator of d , in which m is obtained by using the estimator of C in the formula for m ^(opt) above. We also study the performance of a bias-corrected version of the plug-in estimator of d . Comparisons with the choice m = n ^1/2 frequencies, as originally suggested by Geweke and Porter-Hudak (The estimation and application of long memory time series models. Journal of Time Ser. Anal. 4 (1983), 221–37), are provided.     

Benthic macroinvertebrate assemblages in large river secondary channels: Contemporaneous and legacy effects of flow connectivity

In large rivers, secondary channels occur where the main channel is divided by an instream island, forming one or multiple smaller channels outside the main channel. Secondary channels are highly variable in morphometry, flow characteristics, and degree of connectivity to the main channel. Engineered closing structures at the upstream end of most secondary channels restrict inflow from the main channel, resulting in gradients of flow connectivity among secondary channels that vary with river stage. We investigated the relationship of flow connectivity to benthic macroinvertebrate assemblage richness and structure among a series of secondary channels of the Lower Mississippi River. Samples were collected over 2 years at times of high and low river stages. We discovered (1) macroinvertebrate assemblage structure and taxonomic richness varied along the flow connectivity gradient, and (2) there was a legacy effect of prior connection on assemblage structure that lasted up to a year. We contend that for management and restoration planning aimed at conservation of large river biological diversity, an important consideration are the life history requirements of animals utilizing secondary channel habitats.     

Operation of a full-scale pumped flow biofilm reactor (PFBR) under two aeration regimes

A novel technology suitable for centralised and decentralised wastewater treatment has been developed, extensively tested at laboratory-scale, and trialled at a number of sites for populations ranging from 15 to 400 population equivalents (PE). The two-reactor-tank pumped flow biofilm reactor (PFBR) is characterised by: (i) its simple construction; (ii) its ease of operation and maintenance; (iii) low operating costs; (iv) low sludge production; and (v) comprising no moving parts or compressors, other than hydraulic pumps. By operating the system in a sequencing batch biofilm reactor (SBBR) mode, the following treatment can be achieved: 5-day biochemical oxygen demand (BOD5), chemical oxygen demand (COD) and total suspended solids (TSS) reduction; nitrification and denitrification. During a 100-day full-scale plant study treating municipal wastewater and operating at 165 PE and 200 PE (Experiments 1 and 2, respectively), maximum average removals of 94% BOD5, 86% TSS and 80% ammonium-nitrogen (NH4-N) were achieved. During the latter part of Experiment 2, effluent concentrations averaged: 14 mg BOD5/l; 32 mg COD(filtered)/l; 14 mg TSS/l; 4.4 mg NH4-N/l; and 4.0 mg NO3-N/l (nitrate-nitrogen). The average energy consumption was 0.46-0.63 kWh/m3(treated) or 1.25-1.76 kWh/kg BOD5 removed. No maintenance was required during these experiments. The PFBR technology offers a low energy, minimal maintenance technology for the treatment of municipal wastewater.     

Sandtray therapy with a 24-year-old woman in the residual phase of schizophrenia.

Sandtray therapy is a clinical tool for helping a client express and understand his or her unconscious dynamics. It utilizes a sandtray and anywhere from a few hundred to a few thousand figurines in the room for the client to select from. These figurines cover a wide range of people, situations, and objects, from the most ordinary to the mythical. The client makes a story in the sand, which the client and therapist then discuss. It is standard therapeutic wisdom that one should not use techniques involving fantasy with psychotic clients since it is typically too hard for both them and the clinician to contain those fantasies in a healthy manner. Although this is very often true, the authors offer an example of how they were able to use sandtray to great therapeutic advantage with a schizophrenic client in the residual phase of schizophrenia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Respirometric Assessment of Primary Sludge Fermentation Products

This study investigates the potential of primary sludge fermentation for the generation of readily biodegradable substrate. Experimental evaluation indicates that uncontrolled fermentation converted 22% of the initial volatile suspended solids in the sludge into soluble biodegradable chemical oxygen demand (COD). More than 85% of the soluble COD generated was associated with the formation of short chain volatile fatty acids (VFAs). The recoverable fraction of the fermented sludge supernatant may potentially increase the biodegradable COD content of the primary effluent by 5%. The VFA composition predominantly involved acetic and propionic acids as reported in the literature. Due to the high VFA content, activated sludge Model No. 1 could not predict the COD fractionation in the primary sludge; activated sludge Model No. 3 provided a better interpretation of the oxygen uptake profile through initial storage of the VFAs in the sludge.     

Method for Measuring Dipole Parameters of Isolated Hearts and Muscles?Application to Frog Gastrocnemius

Resistor networks were developed to measure the magnitude, direction, and location of the resultant dipole moment of isolated hearts or muscles located at the center of a fluid-filled dish. With the network connected to the dish electrodes, these quantities could be determined from only four bipolar voltage measurements. Energized muscle strips were simulated by dipping pieces of metal of different lengths into the electrolyte. The resultant location was found to be midway between the centers of the two pieces, rather than at the gap between them.     

Isolation of a spotted fever group rickettsia from the Pacific Coast tick, Ixodes pacificus, in Oregon

A rickettsia of the spotted fever group was isolated on three occasions from Ixodes pacificus in western Oregon. These isolations, and additional evidence furnished by complement fixation tests on guinea pigs inoculated with other Oregon ticks of this species, indicate that the association of this rickettsia with the Pacific Coast tick may be widespread. This is the first isolation of a spotted fever group rickettsia from I. pacificus. Because the Oregon isolates are mildly virulent for guinea pigs they resemble the Western U and Rickettsia montana strains of rickettsiae. However, preliminary evidence from cross-immunofluorescence tests of mouse antisera suggests the Tillamook and Grants Pass strains are antigenically different from all known spotted fever group agents.