62 research outputs found
Possible roles, positions, factors and components of dairying in organic farming – a rewiev, mapping, survey and comparison in the Czech Republic
The full-value experiment is questionable in evaluation organic dairying. It is problem to do a trial under
comparable conditions for comparison of organic and conventional farming because of legislative reasons
and necessity of long period of such event. Most of comparisons are carried out as practice descriptive
observations and any of them has been carried out about milk production. That is main reason, why the aim of
this work is to carry out a opening of monitoring of some production conditions and results of bio-dairying in
the Czech Republic (CR). The quality aspects of sources, procedures and products are main topics of solution
of projects about organic farming philosophy, in particular in solution of organic dairy foodstuff chain. There
were choosen twelve organic dairy farms (survey II, 2006) for more detail research of production conditions
according to results of exploratory questionnaire (2006, survey I, n = 85 pieces of questionnaire and 58
organic farms, which practicise dairying) in the CR. The climatology characteristics of selected organic dairy
farms were as follows: (I) 562±149 m above sea level on the average (from 270 to 970 m a. s. l.); (II)
571.0±69.9 m above sea level, mean year temperature 6.0±1.1 ºC and average year rainfall sum 843.0±184.3
mm. It is clear according to previously mentioned figures that the organic (ecology) dairy farming is realized
mostly in the mountain or sub-mountain areas (less favourable areas, LFAs) as compared to climatic
conditions of CR mean profile.
The results of investigation of organic farm (E) and breeder conditions and dairy cow health state,
reproduction performance and milk quality in organic farms (I data file) as compared to conventional dairy
cow herds (K) were: milk yield (E) was 14.2±3.4 kg of milk/cow/day on average and 5165±1112 kg/cow/year;
E farms have 50 % free stables, some of them as different untraditional modifications (mostly in herds with
low number of dairy cows); it is necessary to increase this amount for welfare improvement in the future;
there are 52 % of binding stables in K herds; there (E) is high occurrence frequency of can milking
equipments (46.4 %); there are 5.4 % cases of hand milking, 21.4 % of pipeline milking equipments and 26.8
% of milking parlours; there (K) are 3 % of can milking equipments, 50 % of pipeline milking equipments
and 47 % of milking parlours; the average organic herd has 60±91 heads it means about 1/3 of K herd in the
CR; geometrical average (xg) of organic herd size is 17 heads; daily milk deliveries were 1318±1475 kg in
summer and 976±1368 kg in winter season (there is too high variability in the mentioned indicators); breed
structure of E herds is 59.8 % of Bohemian Spotted cattle, 18.8 % of Holstein (H), 12.5 % of Jersey breed; H
breed is dominating 47.5 % in K herds; average ratio of excluded milk (for secretion disorders or treatment)
is 2.99 % in E herds and 4.6 % in K herds (P<0.01); also there (E) is lower occurrence of clinical mastitis
0.53±1.97 %; service period is 124.3 days in K and 98.7±46,1 days in E herds on average (P<0.01); there (E)
is better insemination index 1.66±0.45 in comparison to K herds 2.07 (P<0.01); there is longer longevity as
duration of production life of dairy cows in E herds (6.02 lactations, „about 141 % better”) in comparison to
K herds (2.50 lactations, P<0.01); milk quality showed the average total mesophilic bacteria count (CPM)
36.0±26.8 ths. CFU/ml in organic farms (E), which is comparable to the conventional farms (K); somatic cell
count (PSB) was 192±87 ths./ml in E herds and 256 ths./ml in K herds, which is in connection with the lower ratio of milk exclusion from delivery in E herds; an occurrence of residues of inhibitory substances (RIL) was
not reported in E herds, which is more advantageous in comparison to the K herds (0.16 %) and it could be
an impact of lowered antibiotica drug use; the average fat and lactose contents (T; 4.05±0.19 %) and (L;
4.83±0.15 %) are well comparable with K farms and the results show on higher energy deficiency in E herd
nutrition.
The water quality (II) is necessary in dairying as well. Drinking water is necessary for health of animals
(their watering) and for milk quality (milking equipment sanitation) as well. Drinking water is asked in dairy
farms by legislation. The E farm water quality: the nitrate level varied in the range from 1.63 to 28 mg/l with
average 10.5 mg/l in ecological farms and standard limit 50 mg/l was not exceeded; the levels of nitrite and
ammonia ions were mostly under detection limit of method; legislative limit <0.5 mg/l was not exceeded by
nitrite and once by ammonia ions 0.81 mg/l. The microbiological indicators are more sensitive of course. In
total the limits were exceeded 7× u in coliform bacteria, 3× in streptococci and Escherichia coli was
confirmed 3× (in comparison to demand 0). Therefore it is necessary to take care of incidental water source
sanitation.
The effect of origin of water source (communal water pipes or own well in the organic farm area) which
was used in the organic farming (II) was: the more marked result differences were not observed between own
wells (S) and communal water supply (V) in E farms; an exception was stated in insignificantly better results
of hygienic indicators of communal supply; therefore it is necessary to put the higher importance on
sanitation of own water sources. There were identified eight own wells and four communal supply. E. g.
nitrate levels were a little higher for wells 11.7 > 8.2 mg/l. The nitrites were not different. Chemical oxygen
consumption was 0.45 and 0.52 mg/l. The more expressive differences were identified in chlorides, sulphates
and Mg: 8.33 and 3.02 mg/l; 27.9 and 16.8 mg/l; 18.9 and 3.5 mg/l
SEPARATION OF SULFUR-CONTAINING FATTY ACIDS FROM GARLIC, ALLIUM SATIVUM, USING SERIALLY COUPLED CAPILLARY COLUMNS WITH CONSECUTIVE NONPOLAR, SEMIPOLAR, AND POLAR STATIONARY PHASES
SUMMARY A GC-MS method with serially coupled capillary columns containing consecutive nonpolar, semipolar, and polar stationary phases has been used for determination of fatty acids in garlic (Allium sativum). Saturated (14:0, 15:0, 16:0, and 18:0), unsaturated (7-16:1, 7-18:1, 9-18:1, 9,12-18:2, 9,12,15-18:3), and unusual cyclic sulfur-containing fatty acids in garlic were identified by GC-MS
Influences of Different Milk Yields of Holstein Cows on Milk Quality Indicators in the Czech Republic
The milk yield (MY) is an important economic and health factor closely connected with the health status of dairy cows, their reproduction performance, longevity and milk composition and properties (MIs). The differences within MIs between high yielding herd (Group 1; 10 282 kg per lactation) and three herds with average MY (Group 2; 7 926 kg) were tested. The files with 96 and 290 milk samples were collected in summer and winter feeding seasons and well balanced in lactation factors. Group 1 had higher genetical value, better nutrition and was milked three times per day and its MY was higher by 30% (P P P > 0.05). The U was probably higher due to higher loading of the nitrogen nutrition (4.27 > 3.57 mmol l-1) in MY 1. Surprisingly, SCC was higher (112 > 81 103 ml-1) and AC lower ((0.0374) 0.0250 -1) in Group 1. Both the MIs did not indicate problems of the health status. An indicator of energy nutrition balance as fat/protein ratio was not influenced (1.15 ± 0.24 versus 1.16 ± 0.23; P > 0.05), despite the large difference between MY 1 and 2. URN was higher in MY 1 (46.5 > 39.1%) due to more efficient nutrition, like in U. The high MY had no negative impacts on MIs with well balanced nutrition of Holstein cattle
Spin states of asteroids in the Eos collisional family
Eos family was created during a catastrophic impact about 1.3 Gyr ago.
Rotation states of individual family members contain information about the
history of the whole population. We aim to increase the number of asteroid
shape models and rotation states within the Eos collision family, as well as to
revise previously published shape models from the literature. Such results can
be used to constrain theoretical collisional and evolution models of the
family, or to estimate other physical parameters by a thermophysical modeling
of the thermal infrared data. We use all available disk-integrated optical data
(i.e., classical dense-in-time photometry obtained from public databases and
through a large collaboration network as well as sparse-in-time individual
measurements from a few sky surveys) as input for the convex inversion method,
and derive 3D shape models of asteroids together with their rotation periods
and orientations of rotation axes. We present updated shape models for 15
asteroids and new shape model determinations for 16 asteroids. Together with
the already published models from the publicly available DAMIT database, we
compiled a sample of 56 Eos family members with known shape models that we used
in our analysis of physical properties within the family. Rotation states of
asteroids smaller than ~20 km are heavily influenced by the YORP effect, whilst
the large objects more or less retained their rotation state properties since
the family creation. Moreover, we also present a shape model and bulk density
of asteroid (423) Diotima, an interloper in the Eos family, based on the
disk-resolved data obtained by the Near InfraRed Camera (Nirc2) mounted on the
W.M. Keck II telescope.Comment: Accepted for publication in ICARUS Special Issue - Asteroids: Origin,
Evolution & Characterizatio
Asteroids' physical models from combined dense and sparse photometry and scaling of the YORP effect by the observed obliquity distribution
The larger number of models of asteroid shapes and their rotational states
derived by the lightcurve inversion give us better insight into both the nature
of individual objects and the whole asteroid population. With a larger
statistical sample we can study the physical properties of asteroid
populations, such as main-belt asteroids or individual asteroid families, in
more detail. Shape models can also be used in combination with other types of
observational data (IR, adaptive optics images, stellar occultations), e.g., to
determine sizes and thermal properties. We use all available photometric data
of asteroids to derive their physical models by the lightcurve inversion method
and compare the observed pole latitude distributions of all asteroids with
known convex shape models with the simulated pole latitude distributions. We
used classical dense photometric lightcurves from several sources and
sparse-in-time photometry from the U.S. Naval Observatory in Flagstaff,
Catalina Sky Survey, and La Palma surveys (IAU codes 689, 703, 950) in the
lightcurve inversion method to determine asteroid convex models and their
rotational states. We also extended a simple dynamical model for the spin
evolution of asteroids used in our previous paper. We present 119 new asteroid
models derived from combined dense and sparse-in-time photometry. We discuss
the reliability of asteroid shape models derived only from Catalina Sky Survey
data (IAU code 703) and present 20 such models. By using different values for a
scaling parameter cYORP (corresponds to the magnitude of the YORP momentum) in
the dynamical model for the spin evolution and by comparing synthetics and
observed pole-latitude distributions, we were able to constrain the typical
values of the cYORP parameter as between 0.05 and 0.6.Comment: Accepted for publication in A&A, January 15, 201
(704) Interamnia: a transitional object between a dwarf planet and a typical irregular-shaped minor body
Context. With an estimated diameter in the 320–350 km range, (704) Interamnia is the fifth largest main belt asteroid and one of the few bodies that fills the gap in size between the four largest bodies with D > 400 km (Ceres, Vesta, Pallas and Hygiea) and the numerous smaller bodies with diameter ≤200 km. However, despite its large size, little is known about the shape and spin state of Interamnia and, therefore, about its bulk composition and past collisional evolution.
Aims. We aimed to test at what size and mass the shape of a small body departs from a nearly ellipsoidal equilibrium shape (as observed in the case of the four largest asteroids) to an irregular shape as routinely observed in the case of smaller (D ≤ 200 km) bodies.
Methods. We observed Interamnia as part of our ESO VLT/SPHERE large program (ID: 199.C-0074) at thirteen different epochs. In addition, several new optical lightcurves were recorded. These data, along with stellar occultation data from the literature, were fed to the All-Data Asteroid Modeling algorithm to reconstruct the 3D-shape model of Interamnia and to determine its spin state.
Results. Interamnia’s volume-equivalent diameter of 332 ± 6 km implies a bulk density of ρ = 1.98 ± 0.68 g cm−3, which suggests that Interamnia – like Ceres and Hygiea – contains a high fraction of water ice, consistent with the paucity of apparent craters. Our observations reveal a shape that can be well approximated by an ellipsoid, and that is compatible with a fluid hydrostatic equilibrium at the 2σ level.
Conclusions. The rather regular shape of Interamnia implies that the size and mass limit, under which the shapes of minor bodies with a high amount of water ice in the subsurface become irregular, has to be searched among smaller (D ≤ 300 km) less massive (m ≤ 3 × 1019 kg) bodies
(216) Kleopatra, a low density critically rotating M-type asteroid
Context. The recent estimates of the 3D shape of the M/Xe-type triple asteroid system (216) Kleopatra indicated a density of ~5 g cm−3, which is by far the highest for a small Solar System body. Such a high density implies a high metal content as well as a low porosity which is not easy to reconcile with its peculiar “dumbbell” shape.
Aims. Given the unprecedented angular resolution of the VLT/SPHERE/ZIMPOL camera, here, we aim to constrain the mass (via the characterization of the orbits of the moons) and the shape of (216) Kleopatra with high accuracy, hence its density.
Methods. We combined our new VLT/SPHERE observations of (216) Kleopatra recorded during two apparitions in 2017 and 2018 with archival data from the W. M. Keck Observatory, as well as lightcurve, occultation, and delay-Doppler images, to derive a model of its 3D shape using two different algorithms (ADAM, MPCD). Furthermore, an N-body dynamical model allowed us to retrieve the orbital elements of the two moons as explained in the accompanying paper.
Results. The shape of (216) Kleopatra is very close to an equilibrium dumbbell figure with two lobes and a thick neck. Its volume equivalent diameter (118.75 ± 1.40) km and mass (2.97 ± 0.32) × 1018 kg (i.e., 56% lower than previously reported) imply a bulk density of (3.38 ± 0.50) g cm−3. Such a low density for a supposedly metal-rich body indicates a substantial porosity within the primary. This porous structure along with its near equilibrium shape is compatible with a formation scenario including a giant impact followed by reaccumulation. (216) Kleopatra’s current rotation period and dumbbell shape imply that it is in a critically rotating state. The low effective gravity along the equator of the body, together with the equatorial orbits of the moons and possibly rubble-pile structure, opens the possibility that the moons formed via mass shedding.
Conclusions. (216) Kleopatra is a puzzling multiple system due to the unique characteristics of the primary. This system certainly deserves particular attention in the future, with the Extremely Large Telescopes and possibly a dedicated space mission, to decipher its entire formation history
Evidence for differentiation of the most primitive small bodies
Context. Dynamical models of Solar System evolution have suggested that the so-called P- and D-type volatile-rich asteroids formed in the outer Solar System beyond Neptune's orbit and may be genetically related to the Jupiter Trojans, comets, and small Kuiper belt objects (KBOs). Indeed, the spectral properties of P- and D-type asteroids resemble that of anhydrous cometary dust.
Aims. We aim to gain insights into the above classes of bodies by characterizing the internal structure of a large P- and D-type asteroid. Methods. We report high-angular-resolution imaging observations of the P-type asteroid (87) Sylvia with the Very Large Telescope Spectro-Polarimetric High-contrast Exoplanet REsearch (SPHERE) instrument. These images were used to reconstruct the 3D shape of Sylvia. Our images together with those obtained in the past with large ground-based telescopes were used to study the dynamics of its two satellites. We also modeled Sylvia's thermal evolution.
Results. The shape of Sylvia appears flattened and elongated (a/b 1.45; a/c 1.84). We derive a volume-equivalent diameter of 271 ± 5 km and a low density of 1378 ± 45 kg m-3. The two satellites orbit Sylvia on circular, equatorial orbits. The oblateness of Sylvia should imply a detectable nodal precession which contrasts with the fully-Keplerian dynamics of its two satellites. This reveals an inhomogeneous internal structure, suggesting that Sylvia is differentiated.
Conclusions. Sylvia's low density and differentiated interior can be explained by partial melting and mass redistribution through water percolation. The outer shell should be composed of material similar to interplanetary dust particles (IDPs) and the core should be similar to aqueously altered IDPs or carbonaceous chondrite meteorites such as the Tagish Lake meteorite. Numerical simulations of the thermal evolution of Sylvia show that for a body of such a size, partial melting was unavoidable due to the decay of long-lived radionuclides. In addition, we show that bodies as small as 130-150 km in diameter should have followed a similar thermal evolution, while smaller objects, such as comets and the KBO Arrokoth, must have remained pristine, which is in agreement with in situ observations of these bodies. NASA Lucy mission target (617) Patroclus (diameter ≈140 km) may, however, be differentiated
VLT/SPHERE imaging survey of the largest main-belt asteroids: Final results and synthesis
Context. Until recently, the 3D shape, and therefore density (when combining the volume estimate with available mass estimates), and surface topography of the vast majority of the largest (D ≥ 100 km) main-belt asteroids have remained poorly constrained. The improved capabilities of the SPHERE/ZIMPOL instrument have opened new doors into ground-based asteroid exploration.
Aims. To constrain the formation and evolution of a representative sample of large asteroids, we conducted a high-angular-resolution imaging survey of 42 large main-belt asteroids with VLT/SPHERE/ZIMPOL. Our asteroid sample comprises 39 bodies with D ≥ 100 km and in particular most D ≥ 200 km main-belt asteroids (20/23). Furthermore, it nicely reflects the compositional diversity present in the main belt as the sampled bodies belong to the following taxonomic classes: A, B, C, Ch/Cgh, E/M/X, K, P/T, S, and V.
Methods. The SPHERE/ZIMPOL images were first used to reconstruct the 3D shape of all targets with both the ADAM and MPCD reconstruction methods. We subsequently performed a detailed shape analysis and constrained the density of each target using available mass estimates including our own mass estimates in the case of multiple systems.
Results. The analysis of the reconstructed shapes allowed us to identify two families of objects as a function of their diameters, namely “spherical” and “elongated” bodies. A difference in rotation period appears to be the main origin of this bimodality. In addition, all but one object (216 Kleopatra) are located along the Maclaurin sequence with large volatile-rich bodies being the closest to the latter. Our results further reveal that the primaries of most multiple systems possess a rotation period of shorter than 6 h and an elongated shape (c/a ≤ 0.65). Densities in our sample range from ~1.3 g cm−3 (87 Sylvia) to ~4.3 g cm−3 (22 Kalliope). Furthermore, the density distribution appears to be strongly bimodal with volatile-poor (ρ ≥ 2.7 g cm−3) and volatile-rich (ρ ≤ 2.2 g cm−3) bodies. Finally, our survey along with previous observations provides evidence in support of the possibility that some C-complex bodies could be intrinsically related to IDP-like P- and D-type asteroids, representing different layers of a same body (C: core; P/D: outer shell). We therefore propose that P/ D-types and some C-types may have the same origin in the primordial trans-Neptunian disk
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