The ciliate Diploplastron affine is known as a common species of the rumen fauna in cattle and sheep. This protozoon is able to digest cellulose, whereas its amylolytic activity is not well known. ...The objective of the reported studies was to examine the ability of D. affine to digest starch and to use this polysaccharide to cover the requirement for energy. The enzymatic studies showed that the protozoal cell extract degraded starch to reducing products with the rate being equivalent to 2.4 ± 0.47 μmol/L glucose per mg protein per min. Maltose, maltotriose and a small quantity of glucose were the end products of starch degradation. The degradation rate of maltose was only 0.05 μmol/L glucose per mg protein per min. Two peaks in α-amylase and a single peak in maltase activity were found following molecular filtration of ciliate cell extract, whereas three starch-degrading enzymes were identified by a zymographic technique. Incubation of the bacteria-free ciliates with starch in the presence of antibiotics resulted in a release of volatile fatty acids with the net rate of 25 pmol per protozoan per h. Acetic acid followed by butyric acid was the main product of starch fermentation. The results confirmed the ability of D. affine to utilize starch in energy-yielding processes.
Photometric observations of 283 Emma (1998, 2000, 2001, 2004), 665 Sabine (1998, 1999, 2001, 2004, 2005), and 690 Wratislavia (1998, 2000, 2004, 2005- 2006) carried out on 44 nights at two ...observatories are presented. Using all available lightcurves, the spin vectors, senses of rotation, and shape models for these three asteroids have been determined.
CCD photometry of 809 Lundia obtained between September 2005 and January 2006 at Borowiec and Pic du Midi Observatories demonstrates that this object is a synchronous binary system with an orbital ...period of 15.418 ± 0.001 h. In this paper, we present the results of photometric observations of Lundia from two oppositions in 2005/2006 and 2007, as well as the first modelling of the system. For simplicity we assumed a fluid-like nature for each component with a modified Roche model and a triaxial ellipsoid shape in kinematic models. Our models provided similar results. Poles of the orbit in ecliptic coordinates are lambda = 119 ± 2°, beta = 28 ± 4° (modified Roche) or lambda = 120 ± 5°, beta = 18 ± 12° (kinematic). Triaxial ellipsoid shape solutions and a separation between components of 15.8 km are given after taking an equivalent diameter of 9.1 km from H = 11.8 mag and assuming an albedo of 0.4. The orbital period of the Lundia system obtained from modelling is the same as from the lightcurve analysis i.e., 15.418 ± 0.001 h. The bulk density of both components is 1.64 or 1.71 ± 0.01 g/cm^3. The double system of Lundia probably originates from the fission process of a single body that could have been spun up by the YORP effect. The predicted lightcurves for future oppositions are also presented.
The ability of rumen ciliates to digest chitin is clearly recognized. We investigated the chitinolytic system of the rumen ciliate Eudiplodinium maggii. The ciliates were grown in a selectively ...faunated sheep. They were isolated from the rumen and purified by sedimentation. A crude enzyme preparation was prepared following incubation of ciliates with antibiotics. This was done in order to reduce their contamination with intracellular bacteria. The activity of particular enzymes was examined by quantification of the products released from specific substrates. It was stated that the optimum conditions for the detected activities varied between 4.5 and 5.5 pH, and 45 and 55 °C. β-N-Acetylglucosaminidase was found as an enzyme of the highest activity (4.2 μmol/l released product per mg protein per h). The activities of endochitinase and exochitinase were almost two times lower than that of β-N-acetylglucosaminidase. Zymographic studies revealed the presence of two endochitinases, two exochitinases and two β-N-acetylglucosaminidases in the examined preparation.
We present a set of new photometric observations of three main belt asteroids: 160 Una, 747 Winchester, and 849 Ara. This, combined with the available data, allowed us to construct their physical ...models. The lightcurve inversion method was used to obtain their spins and shapes. We have resolved problems with the rotation period of 160 Una, and found it to be $11.033176 \pm 0.000011$ h, almost twice the value given in the literature.
We present photometric observations of three asteroids: 73 Klytia, 377 Campania, and 378 Holmia, together with their spin and shape models. The models were constructed with the lightcurve inversion ...method, using all available lightcurves of these objects. In the case of Campania, the long persisting doubts about its rotational period have been resolved. Various authors state periods between 8.48 and 16 h, while the period we determined is 11.664401 pm 0.000010 h.
A long-term adaptive optics (AO) campaign of observing the double Asteroid (90) Antiope has been carried out in 2003–2005 using 8–10-m class telescopes, allowing prediction of the circumstances of ...mutual events occurring during the July 2005 opposition Marchis, F., Descamps, P., Hestroffer, D., Berthier, J., de Pater, I., 2004. Bull. Am. Astron. Soc. 36, 1180. This is the first opportunity to use complementary lightcurve and AO observations to extensively study the (90) Antiope system, an interesting visualized binary doublet system located in the main belt. The orbital parameters derived from the AO observations have served as input quantities for the derivation of a whole set of other physical parameters (namely shapes, surface scattering, bulk density, and internal properties) from analysis of collected lightcurves. To completely model the observed lightcurves, we employed Roche figures to construct an overall shape solution. The combination of these complementary observations has enabled us to derive a reliable physical and orbital solution for the system. Our model is consistent with a system of slightly non-spherical components, having a size ratio of 0.95 (with
R
avg
=
42.9
±
0.5
km
, separation
=
171
±
1
km
), and exhibiting equilibrium figures for homogeneous rotating bodies. A comparison with grazing occultation event lightcurves suggests that the real shapes of the components do not depart from Roche equilibrium figures by more than 10%. The J2000 ecliptic coordinates of the pole of the system are
λ
n
=
200
°
±
2
°
and
α
n
=
38
°
±
2
°
. The orbital period was refined to
P
=
16.5051
±
0.0001
h
, and the density is found to be slightly lower than previous determinations, with a value of
1.25
±
0.05
g
/
cm
3
, leading to a significant macro-porosity of 30%. Possible scenarios for the origin of the system are also discussed.
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