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The aim of the study was to determine the dependence between Test Day (TD) milk productivity traits and somatic cells count (SCC) in milk and also the influence of the factors: farm, parity and TD recording season of Holstein cows. The survey included a total of 484 lactating cows from 8 cattle farms in Bulgaria. A total of 3473 TD records including data on TD milk yield, fat %, protein % and SCC in milk were used. A statistically significant effect of the farm, recording season, and SCC on TD milk yield, fat % and protein % was reported. The highest TD milk yield was reported in spring (22.42 kg), followed by winter (21.95 kg). In winter and autumn were reported higher mean values for TD fat (3.77 and 3.84%) and TD protein (3.38 and 3.40%) content in milk. At the highest SCC – above 999 000 cells/ml, the highest average daily milk yield – 24.1 kg and the lowest fat (3.48%) was reported. With the highest and positive statistically significant value was the phenotypic correlation between TD milk yield and SCC (0.21). The correlation with TD fat % was statistically significant, with negative value (- 0.07).

Received: October 6th, 2020 ; Accepted: February 1st, 2021 ; Published: March 18th, 2021 ; Correspondence: tonchopenev@abv.bg The aim of the research was to study the effect of heat stress (HS) on some physiological and productive traits in Holstein-Friesian dairy cows. The study included 22 cows on different parities. In the building where the cows were housed, the temperature-humidity index (THI) was reported at 10:00 and 15:00 h, at the same time the rectal temperature (RT) and respiratory rate (RR) were reported for each of the examined cows. The daily rumen activity was taken from the SCR system by Allflex. The average THI values in May were 71, in June - 75, in July - 74, and in August - 77, from which it follows that in the summer months the cows were in conditions of mild to moderate heat stress throughout the day. The average daily milk yield of the cows increased from May to June and reached 41.44 kg day-1 , then decreased in July and August to 37.2 and 32.48 kg day-1 , respectively. With an increase in the THI values, an increase in the RR and RT was registered, as in THI above 79 the RR was 56.54 per min, and the RT was 39.33 °C. With increasing the THI values, the rumination of the cows decreased from 563 per day at THI < 72 to 542.5 at THI > 79. In cows with high daily milk yield, a higher RT was registered, and in cows with more than 50 kg per day, the RT was 39.09 °С. A more intense rumination was found in cows with higher daily milk yield. In cows with an average daily milk yield of 33.26 kg, an average of 450 ruminations per day were reported, and in those with an average milk yield of up to 42.89 kg - 650 ruminations per day. From the research conducted it was found that the studied physiological traits - rectal temperature, respiration rate and rumination are influenced by HS and the intensity of this effect depend on the daily milk yield of cows and THI levels.

2018 Ocean Sciences Meeting, 11-16 February, in Portland, Oregon, Phytoplankton cell size is a fundamental master trait that affects most phytoplankton ecological processes (e.g. growth rates, grazing rates), as well as sinking rates of the resulting organic matter, and hence the biological carbon pump. Interaction with the environment varies among different size groups; e.g., in nutrient-poor subtropical waters, small phytoplankton acquire nutrients more efficiently due to their higher surface area-to-volume ratio. Conversely, in nutrient-rich waters, large phytoplankton dominate because of higher intrinsic growth rates. Climate driven changes in temperature, light and nutrients result in changes in ecosystem size composition, with implications for global ecology and the biological carbon pump. We have previously shown that ocean ecosystem properties and their climate responses over the 21st century vary much more across climate models than chemical and physical properties, reflecting gaps in biological knowledge and modeling. Here we propose a novel theoretical approach to understand and predict the dynamics of phytoplankton community structure to environmental variability and change. We start by analyzing the biological equations behind simple NPP and NPPZ models and a complex climate model (GFDL-TOPAZ) and make analytical predictions about the relative response of two major phytoplankton size classes to climate change. We predict the existence of critical background nutrient thresholds which separate regimes where small (large) phytoplankton respond more (less) to nutrient, temperature or light changes, respectively. We next focus on defining emerging relationships between (a) large phytoplankton biomass and total biomass; (b) percent large phytoplankton and total biomass; (c) Chl and phytoplankton biomass (carbon). We test our theoretical predictions across other CMIP5 (Coupled Model Intercomparison Project 5) climate models and with observations of phytoplankton community composition from in-situ and satellite color data

2018 Ocean Sciences Meeting, 11-16 February, in Portland, Oregon, Many climate models show strong variability in preindustrial Southern Ocean (SO) sea surface temperatures (as well as heat fluxes, sea-ice, salinity, and mixed layer depths) associated with open-ocean deep convection through polynyas. The CM2MC model, a coarse-resolution 3° version of GFDL’s ESM2M model, demonstrates regular multi-decadal variability of SO open-sea convection in a 5000-year-long control simulation. Under climate-driven freshening of the surface Southern Ocean, polynya-mediated convection shuts down. We explore the mechanisms for regular SO convection—and its climate-driven shutdown—by analyzing results from 3-member ensembles of a long control simulation, historical and RCP8.5 scenarios up to the year 2100, a SO wind increase experiment, and a SO freshwater hosing experiment. We hypothesize that this regular SO variability is primarily driven by a shallow preconditioning mechanism, where near-surface density anomalies induce destratification of the water column at the site of polynya formation. We also explore a simple 2 layer and sea-ice column model to understand this convective oscillation. We hypothesize that a delicate equilibrium between warming from CDW, cooling from the atmosphere, and freshening from ice dynamics can explain the emerging time-scales of internal oscillation in the system. SO water mass formation is significantly impacted by variability in convection. We propose that Antarctic Bottom Water (AABW) formation and the Antarctic Circumpolar Current (ACC) increase in decades with strong convection, while Antarctic Intermediate Water (AAIW) decreases. An analysis of the oceanic implications of a permanent shutdown of convection with climate warming (and under freshwater hosing) shows AABW formation drastically decreasing, along with complex behavior of the intermediate and mode waters. The AABW and AAIW also serve as teleconnections pathways for northward propagation of temperature and salinity anomaly signals, respectively. These signals propagate with a rapid 20-year timescale, indicating an important role for large-scale waves

The spatial distribution of the air-sea flux of carbon dioxide is a poor indicator of the underlying ocean circulation and of ocean carbon storage. The weak dependence on circulation arises because mixing-driven changes in solubility-driven and biologically-driven air-sea fluxes largely cancel out. This cancellation occurs because mixing driven increases in the poleward residual mean circulation result in more transport of both remineralized nutrients and heat from low to high latitudes. By contrast, increasing vertical mixing decreases the storage associated with both the biological and solubility pumps, as it decreases remineralized carbon storage in the deep ocean and warms the ocean as a whole.

Homocysteine lowering with folic acid has been shown to be ineffective in reducing vascular events in patients with established cardiovascular disease. However, it may be beneficial in the early stages of atherosclerosis particularly for the population at risk. We have investigated the effect of folic acid administration on homocysteine levels, endothelial function, and leukocyte adhesion molecules in atorvastatin-treated patients. Thirty-nine patients were randomized to folic acid 5 mg daily or no additional treatment. Plasma total homocysteine levels were determined by high-performance liquid chromatography. Biochemical and hematologic tests were performed using routine automated analyzer methods. We examined the expression of l-selectin (CD62L); α -subunits of integrins LFA-1 (CD11a), Mac-1 (CD11b), and VLA-4 (CD49d); and β -subunit of β -2 integrins (CD18) by an immunofluorescence method using single-step staining of whole blood with monoclonal antibodies. The fluorescence was quantified by flow cytometry. Reactivity of the forearm skin microvascular bed to thermal and ischemic stimuli was measured using laser Doppler flowmetry. Postocclusive and thermal reactive hyperemia tests were performed. Statistical analysis used 2-sample t test and paired t test. Homocysteine levels decreased significantly in the folic acid–treated group (11.78 ± 2.7 vs 9.75 ± 1.89 μ mol/L, P μ mol/L). There was no effect of folic acid treatment on leukocyte expression of cell adhesion molecules or microvascular reactivity. The lack of effect of folic acid on microvascular reactivity and leukocyte adhesion molecules supports the evidence against the beneficial effects of folic acid administration in the early stages of atherogenesis.

In the field of livestock breeding the investigation of the factors that influence to the highest degree the efficiency (e.g. milk yield) is essential for determining the conditions for the improvement of the overall production results. To extract relevant information from the data the appropriate mathematical methods are very useful. The aim of this work is to demonstrate the capabilities of the method of Classification and regression trees (CART) for statistical data processing including data of ordinal and nominal type. For a sample of 97 observations of cattle from 4 farms in Bulgaria, two decision trees are built for studying dependence of the 305 days milk yield for Holshte in cows with respect to 13 independent variables – 12 conformation traits and farm. The model with 12 independent variables for conformation traits describes 48% of the data and identifies the main factors for quantities of milk – udder width, locomotion, stature and chest width with normalized importance 100%, 48.1%, 41.2% and 39%, respectively. The second model includes the farm where the cattle are reared as 13th independent variable and this expanded model accounts for 70% of the data. Following the obtained rules for both models, predictions for new data could be made before end of lactations.

The study included 514 Black-and-White cows from 14 farms of different regions of the country. The cows are on Ist (224), IInd (194) and IIIrd (96) lactation, respectively. A scoring of 24 linear type traits on a scale from 1 to 9 was performed. The average age of first calving (AFC) for all farms included in the study was 880.8 days or 29.4 months. By farms the average age varies from 729.1 to 1266.7 days. A statistically significant effect of age at first calving on the following linear type traits was found: chest width, body depth, rump angle, rump width, fore udder attachment, rear udder height and rear udder width. Between AFC and linear traits stature, chest width, rump angle, rear legs rear view, bone structure, rear udder height, rear udder width and BCS significant negative phenotypic correlations with low to moderate values from -0.12 to -0.27 were reported. Between AFC and the traits fore udder attachment and teat length a significant positive phenotypic correlation of 0.17 and 0.13, respectively, was reported. Cows calved for the first time at an optimal age from 24 to 30 months of age had a wider chest, deeper body, wider rump and rear udder and wider and parallel placed rear legs and thinner and refined bones. The higher age of first calving – over 35 months was not associated with better development of the cows.

We examined the effects of interferon-alpha (IFN-alpha) treatment on the growth, cell cycle, proliferation, and apoptotic parameters as well as adhesive properties and proteome of chronic myelogenous leukemia (CML)-derived K562 cells. IFN-alpha treatment (200 to 600 U/ml, 24 to 72 h) suppressed growth and caused accumulation of K562 cells in the S-phase of cell cycle (increase in S-phase cells by up to 52% in comparison with the untreated controls) at the expenses of cells in G1-phase. No transition of cells to G0-phase occurred as followed from Ki-67 protein determination. Although the level of chimeric gene product, BCR-ABL mRNA coding for BCR-ABL protein with anti-apoptotic properties, decreased by 30%, apoptosis was not triggered as judged from Annexin-V, APO2.7, and TUNEL assays. Adhesion of K562 cells to fibronectin-coated surfaces increased by up to 52% as determined by calcein assay. The proteomic analysis (2-D electrophoresis in combination with mass spectrometry, MALDI-MS) revealed a single protein, ubiquitine cross-reactive protein (UBCR), whose level markedly increased due to IFN-alpha treatment. The ubiquitination-like directed degradation processes may thus play a role in the mechanism of IFN-alpha antiproliferative effects.

Background Comparison between consensual approaches for the detection of paroxysmal nocturnal hemoglobinuria (PNH) clones by flow cytometry (FCM) following the international clinical cytometry society (ICCS) guidelines has not been widely reported. Methods We determined the performance characteristics of 4, 5, and 6-color protocols for white blood cell (WBC) and one and two-color protocols for red blood cell (RBC) evaluation for different PNH target clones and compared results from PNH patient analysis. Results Coefficient of variation (CV) for precision/reproducibility analysis ranged from 0.01%/0.12% to 2.56%/ 3.59% for granulocytes, from 0.07%/0.08% to 3.87%/11.61% for monocytes and from 0.4%/1.02% to 6.53%/ 5.1% for RBCs within different approaches and target PNH clones. Comparison of individual protocols revealed excellent correlation (r = 0.99), Wilcoxon rank tests found no statistically significant differences (p > 0.05), Bland-Altman analysis proved agreement for all PNH clones (mean bias ranging from 0.02 to 2.2). Conclusions Our results confirm good intralaboratory characteristics for precision and reproducibility analysis, excellent correlation and agreement between approaches underlining the primary role of optimally selected glycophosphatidylinositol (GPI)-specific reagents and secondary role of number, type of gating reagents and gating strategy.

Selection based on real problems with the legs and feet – the case of lameness, has low efficiency. Linear type traits describing the structural differences in different body parts including those of the legs and feet can be evaluated directly in a large number of animals at an early stage in the life of cows, by not a large number of specialists. Type traits of legs and feet have low to medium heritability values. There is a genetic relationship both among the various linear foot and leg traits and between them and the issues with animal locomotion. The selection for optimal angle of the foot and the rear leg side view, straight rear legs rear/back view, flat and refined bones and proper locomotion – will result in reduced locomotion problems and diseases of the legs and feet in dairy cows. Negative correlation has been found between problems with legs and feet, milk production and reproductive performance. Problems with legs and feet are one of the causes of premature culling and reduced longevity of dairy cows.

The aim of the present study was to study the effect of the season, period and number of lactation on mastitis incidence and milk yields in dairy cows. The climate in Bulgaria implies the presence of seasonal variations in mastitis prevalence in dairy cows, reared in free-stall barns all the year round: spring – 5.33%, summer – 4.9%, autumn – 4.2% and winter – 4.5%. The mastitis incidence during the lactation periods increased gradually from calving to the 120th lactation day. For the first 120 days of lactation, the mastitis incidence attained 26%. The reduction in milk yields after the lactation peak was associated with gradual decliine in cows affected by mastitis to 1.7% during the last month of lactation. With increasing the number of lactations, mastitis incidence also increased: 23.3% in 1st lactation cows, 26.7% in 2nd lactation cows, 48.9% in 3rd lactation cows and 43.3% in cows in fourth or subsequent lactation. The highest daily milk yield at the peak of lactation (34.05 kg) was established in cows affected by mastitis after the 180th lactation day, followed by cows with mastitis between the 60th and 180th lactation days (32.54 kg), and third came healthy cows (31.98 kg). The lowest daily milk yield at the peak of lactation was demonstrated in cows affected by mastitis in the first 60 days of the lactation (29.39 kg). It was proved that cows with exceptionally high milk yields in the beginning of lactation were more prone to mastitis at a later stage due to weakened systemic resistance and consequent disease. Cows with relatively lower milk yield during the lactation period (7580.3 kg) were more resistant to environmental factors, therefore were not affected by mastitis and produced highquality milk with lower costs vs those with highest milk yields affected by mastitis after the 180th day. These cows produced more milk (7607.9 kg) within a 305- day lactation, but the treatment costs could be hardly compensated. Cows in which mastitis occurred until the 60th and between the 60th and 180th lactation day, produced 7215.5 and 7484.1 kg milk, respectively. The average milk yield per lactation of healthy cows was by 137.83 kg higher than that of cows with mastitis. A statistically significant reduction in milk fat (Р < 0.05) and milk protein (Р < 0.001) between healthy and diseased cows was observed.

The study comprises 143 Black-and-White cows from three cattle farms with free cubicle rearing (one) and tied rearing (two). The number of cows by farms is as follows: farm 1 – 69 cows, farm 2 – 34 cows and farm 3 – 40 cows. All cows in lactation from Ist to VIIth at the time of evaluation have been included, respectively in Ist lactation – 40 cows, in IInd – 28 and in IIIrd and further lactation – 75 cows. To assess the temperament a 5-point scale has been used, respectively 1 – very nervous and 5 – very calm cows. Recording the milking temperament has been done once during lactation and all cows currently in lactation on the three farms have been assessed. Primiparous up to the 30th day after calving have not been included in the assessment. Statistically significant effect of the farm on the milking temperament score has not been reported. In the three studied farms relatively high, above 80% share of calm cows has been reported – scores from 3 to 5. The highest is the relative share of nervous animals (scores 1 and 2) of farm 2 – 17.6%, and the lowest – of farm 3 – 12.5%. Statistically significant effect of the number of lactation on the milking temperament score has been reported. The highest is the percentage of nervous animals – 22.5% in cows at first lactation and, respectively, the lowest is the share of the calm ones – 77.5%. With cows after Ist lactation the percentage of nervous cows is half less and it remains almost unchanged in later lactations. The highest is the LS-mean score for the temperament of cows in IIIrd and further lactations – 4.15, followed by those in IInd. The lowest is the LS-mean score for temperament of cows in first lactation – 3.82.

Histone deacetylase inhibitors (HDACi) are emerging new class of anticancer agents that act by inhibiting cell growth, inducing cell cycle arrest and apoptosis of various cancer cells. However, in some conditions, apoptosis can be blocked and non apoptotic cell death and irreversible growth arrest, namely senescence, can be activated as potential tumor-suppressor mechanism. Here we evaluated the dosage effects of HDAC inhibitors suberoylanilide hydroxamic acid (SAHA) and valproic acid (VPA) in a series of human leukaemia cell lines. We investigated, what concentration of SAHA and VPA can optimally induce apoptosis, growth inhibition or stress-induced premature senescence. We have found that SAHA inhibited proliferation and induced apoptosis in concentration 1000x lower than VPA. The senescence phenotype was preferentially induced by lower dosage of HDACi and required longer incubation time (5 days) while apoptosis was induced by higher dosage and appeared already after 24h. The optimal doses for the induction of cell death are 2,5-5 μM of SAHA and 2,5-5 mM of VPA. These doses of HDACi induce both apoptosis and senescence of studied leukemia cell lines.

Nanofibrous polyacrylonitrile membranes (PANNFM) were obtained by electrospinning and then prepared for immobilizing acetylcholinesterase (AChE). Initially, the chemical modification of PANNFM with ethylenediamine produced reactive groups to overcome their inertness and hydrophobicity. The natural polymer, chitosan, was then tethered on the nanofibrous membranes to improve their biocompatibility. Scanning electron microscopy (SEM) and crosssection SEM were used to determine morphological and porosity changes of the membranes. The immobilized AChE had greater relative activity as well as thermal and storage stability compared to the free enzyme. The bound AChE showed excellent reusability. Chitosan-modified PANNFM was shown to be a suitable strategy for facile immobilization of AChE to produce a promising system that effectively supports biocatalysts.