121 research outputs found

    Shape and spin distributions of asteroid populations from brightness variation estimates and large databases

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    Context. Many databases on asteroid brightnesses (e.g. ALCDEF, WISE) are potential sources for extensive asteroid shape and spin modelling. Individual lightcurve inversion models require several apparitions and hundreds of data points per target. However, we can analyse the coarse shape and spin distributions over populations of at least thousands of targets even if there are only a few points and one apparition per asteroid. This is done by examining the distribution of the brightness variations observed within the chosen population. Aims. Brightness variation has been proposed as a population-scale rather than individual-target observable in two studies so far. We aim to examine this approach rigorously to establish its theoretical validity, degree of ill-posedness, and practical applicability. Methods. We model the observed brightness variation of a target population by considering its cumulative distribution function (CDF) caused by the joint distribution function of two fundamental shape and spin indicators. These are the shape elongation and the spin latitude of a simple ellipsoidal model. The main advantage of the model is that we can derive analytical basis functions that yield the observed CDF as a function of the shape and spin distribution. The inverse problem can be treated linearly. Even though the inaccuracy of the model is considerable, databases of thousands of targets should yield some information on the distribution. Results. We establish the theoretical soundness and the typical accuracy limits of the approach both analytically and numerically. Using simulations, we derive a practical estimate of the model distribution in the (shape, spin)-plane. We show that databases such as Wide-field Infrared Survey Explorer (WISE) yield coarse but robust estimates of this distribution, and as an example compare various asteroid families with each other.Comment: 16 pages, 21 figures, manuscript accepted in Astronomy & Astrophysics, to be published in section 10. Planets and planetary system

    Possible roles, positions, factors and components of dairying in organic farming – a rewiev, mapping, survey and comparison in the Czech Republic

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    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

    A COMPARISON OF SELECTED MILK INDICATORS IN ORGANIC HERDS WITH CONVENTIONAL HERD AS REFERENCE

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    In a historical sense, current organic farming is an old-new alternative under changed world conditions. Organic dairying (O) is an alternative of friendly use of the environment in time of presupposed global climate changes. Potential impact of organic farming on raw cow-milk quality, composition and properties, as conpared to conventional milk production (C), were evaluatedin this paper on the basis of selectedm ilk indicators (MIs). Total solids, whey volume, pH of milk fermentation ability (FAM-pH), FAM streptococci, FAM noble lactic acid bacteria, I and Cu were higher in C milk (P0.05) were observed in pH, rennet coagulation time, curd quality, FAM lactobacilli and streptococci/lactobacilli, Na, Mn and Zn. In general, the differences were a little more advantageous for O milk from both technological and nutritional point of view, particularly because of AS (0.461 .81m m), FAM-T (27.3 4.6 ) , Ca (1172 < l257 mg.kg-1)P, ( 950 < l004 mg. kg-1) and Mg 107.4<ll2.0mg.kg{) results. Organic milk can also produce better environment for yoghurt fermentation. Nevertheless, the results obtained should not be overestimated as both sources produced milk of good quality. Additional results are needed to prove organic milk benefits

    Cyclobutane-Containing Alkaloids: Origin, Synthesis, and Biological Activities

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    Present review describes research on novel natural cyclobutane-containing alkaloids isolated from terrestrial and marine species. More than 60 biological active compounds have been confirmed to have antimicrobial, antibacterial, antitumor, and other activities. The structures, synthesis, origins, and biological activities of a selection of cyclobutane-containing alkaloids are reviewed. With the computer program PASS some additional biological activities are also predicted, which point toward new possible applications of these compounds. This review emphasizes the role of cyclobutane-containing alkaloids as an important source of leads for drug discovery

    Impact of Different Milk Yields on Milk Quality in Bohemian Spotted Cattle

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    Building A Winning NFL Roster: Best Practices For Sustained Success

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    The purpose of this capstone is to identify and analyze the factors that contribute to team success in the National Football League through a review of relevant literature, a survey of league personnel, and firsthand experience as a football administrator. This project first studies quantitative data regarding player acquisition, specifically the data behind the NFL entry draft. Next, the current literature regarding off the field processes such as leadership, organizational culture and engagement were reviewed and finally, a two-step Delphi method survey was distributed to a panel of current league professionals. This paper aims to find the most efficient and effective way for teams to acquire players and several ways to optimize that talent based on the best practices researched in organizational culture and leadership

    SEPARATION OF SULFUR-CONTAINING FATTY ACIDS FROM GARLIC, ALLIUM SATIVUM, USING SERIALLY COUPLED CAPILLARY COLUMNS WITH CONSECUTIVE NONPOLAR, SEMIPOLAR, AND POLAR STATIONARY PHASES

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    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

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    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

    ANGULAR CHLOROPHYLL INDICES ESTIMATES DERIVED FROM GROUND-BASED DIURNAL COURSE DATA AND MULTIANGULAR CHRIS-PROBA DATA: TWO CASE STUDIES

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    ABSTRACT At leaf and plant level chlorophyll indices have shown strong correlations with chlorophyll content and photosynthesis-related processes. However, at canopy level additional abiotic and biotic factors confound the fidelity of these indices. For instance, the Photochemical Reflectance Index (PRI) is known to be sensitive to viewing angles and canopy structure. In this paper we present case studies of two natural canopies at different scales where the influence of sun-target-sensor geometry and canopy structure is inter-compared for a range of chlorophyll indices. In the first case study, surface reflectance was measured in a montane grassland ecosystem located at the Bily Kriz experimental study site (Czech republic) using a stationary mounted AISA (Airborne Imaging Spectrometer for Applications) spectrometer. The experimental set-up resulted in a ground pixel resolution of ~2mm. The effects of changing sun angles on the indices were assessed through a diurnal sampling between 9:00 and 15:00 hrs (local time). Classes of shaded and illuminated photosynthetic (PV) and non-photosynthetic vegetation (NPV) were distinguished per image using a pixel wise classification. The relative contributions of confounding factors as well as the influence of the diurnal variability on performance of the selected chlorophyll indices were evaluated. In the second case study, surface reflectance was measured over an Alpine coniferous ecosystem in the Swiss National Park (Switzerland) using multiangular hyperspectral CHRIS-PROBA (Compact High Resolution Imaging Spectrometer onboard the Project for On-board Autonomy) satellite system with a ground pixel resolution of 17 m. The angular signature of PRI and the structure invariant pigment index (SIPI) was assessed using CHRIS data. Besides, we evaluated the influence of varying tree crown composition and varying viewing angles to the chlorophyll indices with a radiative transfer model FLIGHT. In both cases, the PRI and the green NDVI (gNDVI) responded extremely sensitively to the considered confounding factors at canopy level. The Transformed Chlorophyll Absorption in Reflectance Index normalized by the Optimized Soil-Adjusted Vegetation Index (TCARI/OSAVI), designed to be insensitive to background and LAI variations, responded more sensitively than the conventional NDVI. No certain sensitivity was found for SIPI. The pronounced sensitivity of e.g. PRI and gNDVI, on one hand, and the inconsistency between the chlorophyll indices, on the other hand, erodes the fidelity to use these spectral indices as an effective non-destructive chlorophyll detector
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