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  • Author: Robert Mikuła x
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The quasigeoid modelling in New Zealand using the boundary element method

We compile a quasigeoid model at the study area of New Zealand using the boundary element method (BEM). The direct BEM formulation for the Laplace equation is applied to obtain a numerical solution to the linearized fixed gravimetric boundaryvalue problem in points at the Earth's surface. The numerical scheme uses the collocation method with linear basis functions. It involves a discretisation of the Earth's surface which is considered as a fixed boundary. The surface gravity disturbances represent the oblique derivative boundary condition. The geocentric positions of the collocation points are determined combining the digital elevation data and the a priori quasigeoid model (onshore) and the mean sea surface topography (offshore). In our numerical realization, we use the global elevation data from SRTM30PLUS_V5.0, the detailed DTM of New Zealand, the EGM2008 quasigeoid heights, and the mean sea surface topography from the DNSC08 marine database. The gravity disturbances are computed using two heterogeneous gravity data sets: the altimetry-derived gravity anomalies from the DNSC08 gravity database (offshore) and the observed ground gravity anomalies from the GNS Science gravity database (onshore). The transformation of gravity anomalies to gravity disturbances is realized using the quasigeoid heights calculated from the EGM2008 global geopotential model. The new experimental quasigeoid model NZQM2010 is compiled at the study area of New Zealand bounded by the parallels of 34 and 47.5 arc-deg southern latitude and the meridians of 166 and 179 arc-deg eastern longitude. The least-squares analysis is applied to combine the gravimetric solution with GPS-levelling data using a 7-parameter model. NZQM2010 is validated using GPS-levelling data and compared with the existing regional and global quasigeoid models NZGeoid2009 and EGM2008. The validation at GPS-levelling testing network in New Zealand shows a similar STD fit of all investigated quasigeoid models with the geometric height anomalies computed from GPS-levelling data between 7 cm (NZGeoid2009) and 8 cm (NZQM2010 and EGM2008). The inaccuracies of the compiled quasigeoid models in New Zealand are expected to be mainly due to the presence of large systematic errors and inconsistencies of levelling networks throughout the country. Another source of the inaccuracy is an insufficient coverage and a low accuracy of gravity data especially over large parts of the South Island.

Abstract

The aim of the study was to evaluate the distribution and number of mast cells and eosinophils in rat mammary gland tumours induced by N-Nitroso-N-methylurea. The highest density of mast cells was found in cystic papillary adenocarcinomas of grade II. Eosinophils were detected only in the cystic papillary adenocarcinoma of grades I and II, in non-invasive cribriform adenocarcinoma and comedo-type carcinoma. Mast cell populations were observed perivascularly in the tumour stroma, in the host tumour interface, as well as in necrotic areas of neoplasms. Mast cells were observed to be intact according to their morphological changes, collectively referred to as degranulation. The obtained results indicate that mast cells and eosinophils play an important role in tumour micro-environment formation. The increased density of these cells in experimentally-induced rat mammary gland tumours suggests a poor prognosis in these cancers. Our results also confirmed that rat mammary gland tumours are good models for the study of breast cancers.

Abstract

The paper deals with the complex refractive index in the IR light region of two types of samples (i) as prepared black silicon, and (ii) thermally oxidized black silicon (BSi) nano-crystalline specimens produced both by the surface structure chemical transfer method using catalytic Ag evaporated spots (as prepared sample) and by the catalytic Pt catalytic mesh (thermally oxidized sample). We present, compare, and discuss the values of the IR complex refractive index obtained by calculation using the Kramers-Krönig transformation. Results indicate that small differences between optical properties of as prepared black Si and thermally oxidized BSi are given by: (i) – oxidation procedure, (ii) – thickness of the formed black Si layer, mainly, not by utilization of different catalytic metals, and by iii) the different thickness. Contamination of the surface by different catalytic metals contributes almost equally to the calculated values of the corresponding complex refractive index.

Abstract

In this paper, we propose a novel approach to approximate the solution of the Laplace equation with an oblique derivative boundary condition by the finite element method. We present and analyse diverse testing experiments to study its behaviour and convergence. Finally, the usefulness of this approach is demonstrated by using it to gravity field modelling, namely, to approximate the solution of a geodetic boundary value problem in Himalayas.

Abstract

The aim of the study was to determine the effect of the limitation of energy intake by restrictive dry matter intake in the faroff part (from -56 d to -22 d) of dry period on the colostrum quality and the calf immunological status. Thirty-eight Polish Holstein- Friesian Black and White multiparous cows and their calves were randomly allotted to one of the two dietary treatments in the far-off period. In group ADLIB, diet was offered ad libitum (2.0% body weight), while in group REST, dry matter intake was restricted to 1.5% of body weight. Lowered feed intake in the far-off period did not have a statistically significant influence on the quality of colostrum. On the 3rd d of calves’ life, serum concentrations of immunoglobulins, albumins, globulins, total protein, and IGF-1 were not affected by treatments of dam in the far-off period. The concentrations of total Ig and G and A immunoglobulins of 21-day-old calves from cows fed ad libitum during the far-off period was found to be significantly lower compared to REST group. No significant differences in birth weight and growth rate during the first 21 d of life were found. Limiting maternal diet in far-off period did not affect negatively colostrum quality and calves` immune response during early stages of their life.

Abstract

The aim of the study was to investigate experimentally the effects of restricted or ad libitum feeding in the far-off period on performance of dairy cows. Two groups of Polish Holstein-Friesian cows having 19 animals in each group were allotted to two planes of nutrition in the far-off period from -56 to -22 days. The ADLIB group was fed ad libitum (DMI 12.9 kg) while in the RES group the dry matter intake was restricted by 3 kg DM compared to the average dry matter during the last 7 days in the ADLIB group. Average daily energy intake decreased from 8.90 UFL in the ADLIB to 6.83 UFL in the RES group. In the close-up period and after parturition, the cows of both groups were given the same diet. In restrictively fed cows, there was a tendency to a greater decrease in BCS during both the dry period (P=0.09) and lactation (P=0.07). After parturition milk production, fertility indices and blood concentration of IGF-1, insulin and glucose were not significantly affected by the far-off treatment. In the RES group, lower BHBA 3 days before calving and on day 5 of lactation and lower NEFA on day 28 of lactation were recorded. Also in this group higher levels of glucose 3 days before calving, triiodothyronine (T3) on days -30 and 5, and thyroxine (T4) on days -3 and 28 were observed. It is concluded that restricted feeding in the far-off period positively affected blood indicators of lipomobilization during the transition period, but had little effect on performance of lactating cows. In spite of low energy, high-fibre diet offered ad libitum in the faroff period resulted in the energy overfeeding compared to the INRA system recommendation.

Abstract

The aim of the study was to investigate the effect of BCS (Body Condition Score) on the calving day and its decrease during early lactation on the biochemical blood indices and reproductive performance. One hundred and thirty-one Polish Holstein-Friesian cows were divided into three groups according to the North-American body condition score on the calving day (AC≤3.5 point BCS; MID 3.51-3.75 point BCS; FAT>3.75 point BCS) and according to the decrease in BCS during early lactation (HG >0.49 point BCS; WEL 0.49-0.25 point BCS, L<0.25 point BCS). In current study, significant interaction between change of BCS during early lactation and time of blood sampling on BHBA concentration was observed. In the AC group (≤3.5 BCS), the highest concentrations of glucose on 3 and 5 d of lactation compared to the MID and FAT groups and of insulin on 28 d and also IGF-I on 5 and 28 d of lactation compared to the FAT group were recorded. In the FAT group, the highest concentration of NEFA on 3 and 5 d compared to the AC group and of BHBA on 28 d of lactation compared to the MID group was recorded. The body condition score on the parturition day affected the reproductive performance; in the FAT group (>3.75 BCS) the lowest conception rate of the first insemination, insemination index and thereby the longest days open were observed. The highest decreases in BCS (HG >0.49 points) resulted in increased concentrations of NEFA on 3 d and of BHBA on 3 and 5 d. Moreover, in the HG group, the lowest concentration of T3 on 3, 5 and 28 d as compared to the WEL group was recorded. We concluded that the BCS (>3.5 points) on the calving day had a significantly negative effect on the metabolic status of dairy cows in the postpartum period estimated by the concentration of biochemical blood indices characterising carbohydrates (IGF-I, insulin) and lipid (NEFA, BHBA) metabolism and also the reproductive performance such as the conception rate of the first insemination, insemination index, days open. We suggested that the blood serum concentrations of IGF-I and NEFA were the most sensitive biochemical markers of the metabolic status of dairy cows in our study.

Abstract

For several years in Europe, there has been a growing interest in the use of native sources of protein (e.g. lupine seeds) in poultry nutrition. The current study aimed to investigate the effectiveness of a microbial phytase in broiler diets with the addition of different levels of white lupin seeds. A total of 480 one-day-old male broiler chickens (Ross 308) were randomly divided into six dietary treatments (10 replications/8 birds per group). The basal diet contained SBM as the main protein source and experimental treatments were prepared with white lupin meal (WLM) at 3 levels (0, 10, and 20 %) and with or without phytase inclusion. The experiment was divided into two feeding periods: from 1 to 14 day (starter) and from 15 to 35 day (grower). Diets with phytase addition were deficient in Ca, and nonphytate P. All diets were fed in mash form and offered ad libitum. On day 35th excreta were collected and on day 36th, ten chickens from each group were euthanized and blood, tibia, and digesta samples were collected for further analysis. The 20 % addition of WLM negatively increased the content of phytic-P. The results showed that feed conversion ratio (FCR) and body weight gain (BWG) were not affected by phytase inclusion but by the WLM level alone. In addition, birds fed the diet with 20% WLM were characterized to have the lowest BWG and the highest FCR of all groups. There were no significant differences in feed intake (FI) among chickens fed control and experimental treatments. Regardless of the white lupin level addition, phytase addition improved (P<0.001) nitrogen-corrected apparent metabolizable energy (AMEN). In conclusion, the addition of phytase positively influenced the performance and availability of minerals (Ca and P) regardless of the level of WLM used. However, with regard to the use of WLM in poultry nutrition, it can be assumed that 10 % addition is safe and does not affect performance.