Consumption of nematodes by fungivorous mites, Tyrophagus spp. (Acarina: Astigmata: Acaridae).

Free-living nematodes may be attacked and eaten by soil mites which are normally considered fungivores or saprophages. Three species in the genus Tyrophagus, common inhabitants of grassland soils and also common pests in stored products, museums and laboratories, are predators of nematodes. All active stages of the mites will voraciously consume nematodes. When offered nematodes and a choice of other food (baker's yeast and algae), 11% of the Tyrophagus putrescentiae, 23% of the T. zachvatkini, and 56% of the T. similis tested fed on nematodes. Tyrophagus zechvatkini and similis were reared on a diet consisting entirely of nematodes, and developed at rates similar to a fungal diet and produced viable offspring. Agar cultures of Aphelenchus avenae which were inoculated with five mating pairs of Tyrophagus zachvatkini had populations that were one-third less than mite-free controls. Observations indicate that nematodes may be attacked by tyrophagid mites when in a dry, anhydrobiotic state.

Comparison of drinking patterns measured by daily reports and timeline follow back.

The major objective of this study was to compare near real-time daily alcohol consumption data over the course of 366 consecutive days with retrospective reports by means of the timeline follow-back (TLFB). Participants (N = 33) responded for 366 days on an interactive voice response (IVR) system by entering alcohol consumption data daily using the touch-tone pads of their telephones. In-person interviews were conducted every 13 weeks during which participants were administered the TLFB. The correlations between the IVR and TLFB for amount consumed, drinking days, and heavy drinking days were modest. There was a wide variability across participants in their individual correlations for these variables. Participants who were diagnosable with a lifetime DSM-IV alcohol disorder at baseline significantly underreported their drinking compared with participants who were not diagnosable. The authors were unable to ascertain variables that influenced accurate reporting on the TLFB.

An introduction to selected elements of research.

The purpose of this paper, the first in a two-part series, is to provide an introduction to selected elements of research for the practising pharmacist. It is not intended to provide the reader with all the tools necessary to plan, conduct and report a research study. One paper cannot achieve this since entire books have been devoted to single components of research. Through the examination and discussion of the structure of a research report as presented in this paper, the reader should derive a basic understanding of selected aspects of research. A subsequent paper will present an approach to evaluating reports of research studies. The background provided by both papers should make it possible for pharmacists to review more objectively the increasing number of journal articles reporting research studies. Readers should also gain an appreciation of the complexity of the research process and the time required to prepare a paper acceptable for publication. They will not be in a position to evaluate all the details in the research report.

Antagonists of Plant-parasitic Nematodes in Florida Citrus.

In a survey of antagonists of nematodes in 27 citrus groves, each with a history of Tylenchulus semipenetrans infestation, and 17 noncitrus habitats in Florida, approximately 24 species of microbial antagonists capable of attacking vermiform stages of Radopholus citrophilus were recovered. Eleven of these microbes and a species of Pasteuria also were observed attacking vermiform stages of T. semipenetrans. Verticillium chlamydosporium, Paecilomyces lilacinus, P. marquandii, Streptomyces sp., Arthrobotrys oligospora, and Dactylella ellipsospora were found infecting T. semipenetrans egg masses. Two species of nematophagous amoebae, five species of predatory nematodes, and 29 species of nematophagous arthropods also were detected. Nematode-trapping fungi and nematophagous arthropods were common inhabitants of citrus groves with a history of citrus nematode infestation; however, obligate parasites of nematodes were rare.

Species, guilds, and functional groups: taxonomy and behavior in nematophagous arthropods.

Phylogenetic relationship is an indication of shared abilities, or at least of shared constraints, on morphology, physiology, and behavior; but is phylogenetic relationship a sufficient criterion for predicting ecological function? Ecologists have assumed that the function of invertebrates in soil systems can be predicted at a low level of taxonomic resolution, but our research indicates that critical functional parameters -- e.g., feeding behavior, developmental rate, and reproductive mode -- are rarely predictable above the generic level. Since morphology is more strongly conserved than behavior, feeding guilds or functional groups based on broad taxonomic relationship or untested assumptions about correlations between trophic morphology and feeding behavior have little meaning for nematophagous arthropods from grassland soils in Colorado.

Influence of Lectins on Constricting Ring Formation by Arthrobotrys dactyloides.

Incubation of Arthrobotrys dactyloides conidia in the presence of Radopholus citrophilus in lectin solutions with their corresponding sugars did not alter the stimulation of trap formation in solutions containing lectins alone. The lack of inhibition of lectin-stimulated trap formation by sugars or by lectin denaturation and the lack of lectin specificity indicate that the carbohydrate-binding regions of the particular lectins studied are not the stimulatory moieties of these macromolecules.

Colonization of greenhouse nematode cultures by nematophagous mites and fungi.

Unproductive > 7-year-old greenhouse cultures of citrus nematode (Tylenchulus semipenetrans) had a well-developed soil invertebrate fauna that included nematophagous mite species characteristic of Florida citrus groves. Nematophagous mite densities in box cultures were 285 +/- 42 mites/liter, 2.5 to 25 times higher than densities in citrus nematode-infested groves. Vigorous root-knot nematode (Meloidogyne incognita) cultures grown in steam-pasteurized soil had few nematophagous mites until more than 3 months after inoculation. Mite species diversity had a significant (P < 0.0001) positive linear relationship with culture age that explained about one-half the variance in species number. Nematophagous mite densities rose and then fell with culture age. In root-knot cultures > 3-months-old, mite densities often exceeded 1,000 mites/liter. Twelve species of nematophagous fungi also were isolated from greenhouse nematode cultures.

Living on leaves: mites, tomenta, and leaf domatia.

Structures on the surfaces of leaves strongly affect phylloplane mites. Glandular trichomes defend against some plant parasites but can also mire predators. However, leaves with tomenta of nonglandular trichomes are often inhabited by large populations of predatory mites. Tufts of hairs and other minute structures in the vein axils are called leaf domatia. Comparative observations and experimental data demonstrate that leaves with domatia have enhanced levels of predatory mites. By accumulating predatory mites, leaf domatia act as a kind of constitutive defense against herbivores. Mites benefit from leaf domatia by securing a safe place for oviposition and molting. Like several other plant structures, leaf domatia are the manifestation of a long-term and mutually beneficial interaction between plants and arthropods.

Mites in forest canopies: filling the size distribution shortfall?

Although often unobserved or ignored, mites usually exceed all other arthropods in abundance in forest canopies. Second in species richness only to canopy insects, the arboreal acarofauna is composed of multiple lineages of predators, scavengers, grazers, animal associates, and plant parasites that each have radiated extensively in canopy habitats. The canopy fauna is largely complementary to the mite fauna of the forest floor, suggesting that estimates of more than one million living species of mites are not extreme. Most mites are less than a millimeter in length as adults, and canopy mites tend to be smaller than species from other habitats. Even among mites, however, very small species are relatively rare, and diversity increases with decreasing size only to the penultimate size class (0.316-1 mm). This pattern may be explained by declines in microhabitat diversity or host specificity as the limit of body size in a group of organisms is approached.

Lens rotation and spherocylindrical over-refraction as predictors for soft toric lens evaluation.

Prospective data from 72 patients (128 eyes) fitted with one type of soft toric lens of the double slab-off design were analyzed for lens rotation and spherocylindrical over-refraction (SCO) for the purpose of assessing their accuracy as predictors in soft toric evaluation. Initial trial lens data were compared with final lenses and best spectacle refraction. The mean difference in lens rotation between the initial and final lens visits was 9.9 degrees (SD = 11.5 degrees), and the mean difference between the actual refractive astigmatism and the expected astigmatism, calculated from ophthalmic cross-cylinder equations, was 0.22 D (SD = 0.12 D). Considerable variability existed in lens rotation in the various ametropias during the course of several assessments; SCO provides the best evidence of the fit of toric soft lenses. The implications for other lens types are discussed.

Rotational characteristics and stability of soft toric lenses.

Toric soft contact lenses of a double slab-off design were fitted to 72 patients (128 days) with varying refractive requirements. Rotational characteristics and lens stability were studied as related to sphere power, cylinder power, and axis orientation. The patients were followed over a 1-month period. Although rotation of all lenses was skewed nasally, the total number of all lenses showing no rotation or temporal was somewhat greater than those with nasal rotation. In addition lenses of oblique axis displayed the least amount of rotational instability. Finally this study suggests some differences when comparing the rotational characteristics between with-the-rule and against-the-rule astigmatism correction, low vs. high myopia, and myopia vs. hyperopia.

Middle ultraviolet spectroscopy of suppressant-flame interactions.

By minimization of stray light, it is possible to use the middle ultraviolet to gain useful information on flame-suppressant mechanisms.