Effects of pH, sodium bicarbonate, cryoprotectants and foetal bovine serum on the cryopreservation of European eel sperm.

The main objective of the present study was to evaluate the influence of pH and bicarbonate concentration in the activation or inhibition of European eel (Anguilla anguilla) spermatozoa and to evaluate the effect of different cryoprotectants: dimethyl sulphoxide (DMSO), acetamide, ethylene glycol, propanol, glycerol and methanol (MeOH). The effect of these factors was evaluated comparing the percentage of motile cells, the percentage of alive cells (by Hoechst staining) and the spermatozoa morphometry pre- and post-cryopreservation (by computer-assisted morphology analysis). Based on the above findings, three cryoprotectants (DMSO, MeOH and glycerol) were chosen and evaluated in two media (P1 and P1 modified) with different concentrations of NaHCO(3) and in the presence or absence of foetal bovine serum (FBS). The effect of these factors was evaluated comparing the percentage of alive and motile cells post-cryopreservation. DMSO was the cryoprotectant showing better results in relation to the percentage of spermatic alive cells post-freezing and caused a smaller modification of the head spermatozoa morphology. The combination of P1-modified medium with DMSO and containing FBS increased slightly but significantly the percentage of motile spermatozoa post-cryopreservation.     

Nutritional Relationships among Certain Filamentous Fungi and a Marine Nematode

A marine form of nematode, Aphelenchoides sp., can develop and reproduce effectively on viable mycelia of various filamentous fungi including certain widespread marine species. The efficiency of utilization of fungal mycelium by the animal, based on the ratio of the number of nematodes to the dry weight of fungal mycelium, varies greatly among fungi, from less than 100 to as much as 5000 for several of the marine species studied.     

Vergleichende Untersuchungen an Haaren von Labortieren

Comparative examinations on the hairs of laboratory animals
In the white mouse the bristle hairs were on the average 8mm, in the awn hairs 7mm, and the fur hairs 6.5mm long. The values for the white rat were 19mm for the bristle hairs, 11mm for the awn hairs, and 7mm for the fur hairs; they were thus markedly longer. The hairs of the guinea-pig and of the rabbit were two- and three times as long. Hair thickness—especially at the thickest point—was distinctly different for the bristle and awn hairs, while these measurements of the fur hairs did not differ very much among these species. The size of the cuticle scales did not differ much between mouse, rat and rabbit. The medulla of the bristle and awn hairs of mouse and rat and that of the awn hair of the guinea-pig looked similar. However, the medulla of the rabbit was easily distinguished from the other species. The medulla of the fur hairs was constricted only in the mouse and rat. It is possible to identify with certainty the hairs of these four species if complete hair samples are available and if the microscopic measurements given here are taken into consideration.     

Heterocaryotic Nature of Ring Formation in the Predaceous Fungus Dactylella doedycoides

Morphologically indistinguishable conidia of the predaceous nematodeattacking hyphomycete Dactylella doedycoides Drechsler vary in their ability to produce constricting rings, depending upon their heterocaryotic state. Three types are noted: those producing rings with or without stimulation, those never producing rings, and a mixed or wild type, made up of a mixture of the first two types.     

Lunar surface magnetic fields and their interaction with the solar wind: results from lunar prospector

The magnetometer and electron reflectometer experiment on the Lunar Prospector spacecraft has obtained maps of lunar crustal magnetic fields and observed the interaction between the solar wind and regions of strong crustal magnetic fields at high selenographic latitude (30 degreesS to 80 degreesS) and low ( approximately 100 kilometers) altitude. Electron reflection maps of the regions antipodal to the Imbrium and Serenitatis impact basins, extending to 80 degreesS latitude, show that crustal magnetic fields fill most of the antipodal zones of those basins. This finding provides further evidence for the hypothesis that basin-forming impacts result in magnetization of the lunar crust at their antipodes. The crustal magnetic fields of the Imbrium antipode region are strong enough to deflect the solar wind and form a miniature (100 to several hundred kilometers across) magnetosphere, magnetosheath, and bow shock system.     

Frictional melting during the rupture of the 1994 bolivian earthquake

The source parameters of the 1994 Bolivian earthquake (magnitude Mw = 8.3) suggest that the maximum seismic efficiency eta was 0.036 and the minimum frictional stress was 550 bars. Thus, the source process was dissipative, which is consistent with the observed slow rupture speed, only 20% of the local S-wave velocity. The amount of nonradiated energy produced during the Bolivian rupture was comparable to, or larger than, the thermal energy of the 1980 Mount St. Helens eruption and was sufficient to have melted a layer as thick as 31 centimeters. Once rupture was initiated, melting could occur, which reduces friction and promotes fault slip.