Host Selection by the Herbivorous Mite Polyphagotarsonemus latus (Acari: Tarsonemidae)

This study examined the host-selection ability of the broad mite Polyphagotarsonemus latus (Banks) (Acari: Tarsonemidae). To make long-distance-shifts from one host plant patch to another, broad mites largely depend on phoretic association with whiteflies. However, the host plants of whiteflies and broad mites are not necessarily the same. We determined the host-preference and acceptance of free-moving and phoretic broad mites using two behavioral bioassays. We used a choice test to monitor host selection by free-moving mites. In the case of phoretic mites, we compared their rate of detachment from the phoretic vector Bemisia tabaci placed on leaves taken from various host plants. The suitability of the plant was further determined by monitoring mite’s fecundity and its offspring development. We compared the mites’ responses to young and old cucumber (Cucumis sativus cv. ‘Kfir’) leaves (3rd and 8–9th leaf from the apex, respectively), and two tomato (Solanum lycopersicum cvs. ‘M82’ and ‘Moneymaker’). Free-moving mites of all stages and both sexes preferred young cucumber leaves to old cucumber leaves and preferred young cucumber rather than young tomato leaves, demonstrating for the first time that broad mites are able to choose their host actively. As for phoretic mated females, although eventually most of the mites abandoned the phoretic vector, the rate of detachment from the whitefly vector was host dependent and correlated with the mites’ fitness on the particular host. In general, host preference of phoretic female mites resembled that of the free-moving female. Cues used by mites for host selection remain to be explored.     

Use of subcritical fluid chromatography for the separation of enantiomers using packed cellulose based stationary phase

Investigations into the parameters affecting the enantiomeric separation of an intermediate in the synthesis of a drug targeted for cardiac arrhythmia is presented. The separation was achieved under subcritical fluid chromatography using CO₂ modified with methanol and co-modifiers isopropyl amine and methylene chloride. The stationary phase was a cellulose based stationary phase manufactured under the trade name Chiracel OB. The results showed the addition of methylene chloride had a noticeable effect on resolution while the separation factor, α, remained constant. The co-modifier, isopropyl amine, did not considerably influence the resolution, or separation factor. Temperature studies were performed in order to establish the thermodynamic parameters of the interaction between the enantiomers and the stationary phase. Plots of In k′ vs. 1/T proved to be curved, while plots of In α vs. 1/T were linear. © 1996 Wiley-Liss, Inc.     

Thermal sensitivity of enzymes in trisomy 21 leukocytes]

Thermosensitivity of glucose 6-phosphate dehydrogenase and myloperoxidase was investigated in the leukocyte lysates from patients with Down's syndrome. A statistically significant enhancement of thermosensitivity of both the enzymes investigated was revealed in the aberrant cells in comparison with the control. The noted differences can be based on the increased incidence of mutation injuries in the aberrant cells, as well as on anomalous postranslational modification of the protein molecules.     

Mathematical model of interphase cell death. Biophysical justification and generalization

The authors propose a biophysical justification of a radiation-induced injury and interphase death of cells. The injury to certain units of the microtrabecular network and cytoskeleton is considered to be a primary biological effect of radiation on cells. The role of these structural changes in the development of the specific radiation response is discussed. It is found possible to describe formally, by the defined parameters of the proposed model, the survival curves for not only interphase but also reproductive cell death.     

Diabetes and the heart: could the diabetic myocardium be protected by preconditioning?

Both type 1 and type 2 diabetes (insulin-dependent and non-insulin dependent diabetes, respectively) are associated with increased risk for microvascular and macrovascular complications including retinopathy, neuropathy, nephropathy and atherosclerosis. Type 2 diabetes markedly increases the risk for cardiovascular morbidity and mortality, which has major public health implications. In this review, molecular mechanisms pertaining to diabetes-induced heart pathology are addressed.     

L1 (LINE-1) retrotransposable elements provide a "fossil" record of the phylogenetic history of murid rodents

The single most difficult problem in phylogenetic analysis is decidingwhether a shared taxonomic character is due to common ancestry or one thatappeared independently due to convergence, parallelism, or reversion to anancestral state. Mammalian L1 retrotransposons undergo periodicamplifications in which multiple copies of the elements are interspersed inthe genome. Because these elements apparently are transmitted only byinheritance and are retained in the genome, a shared L1 amplification eventcan only be an inherited ancestral character. We propose that L1amplification events can be an excellent tool for analyzing mammalianevolution and demonstrate here how we addressed several refractory problemsin rodent systematics using L1 DNA as a taxonomic character.