East-to-west human dispersal into Europe 1.4 million years ago

Stone tools stratified in alluvium and loess at Korolevo, western Ukraine, have been studied by several research groups1-3 since the discovery of the site in the 1970s. Although Korolevo's importance to the European Palaeolithic is widely acknowledged, age constraints on the lowermost lithic artefacts have yet to be determined conclusively. Here, using two methods of burial dating with cosmogenic nuclides4,5, we report ages of 1.42 ± 0.10 million years and 1.42 ± 0.28 million years for the sedimentary unit that contains Mode-1-type lithic artefacts. Korolevo represents, to our knowledge, the earliest securely dated hominin presence in Europe, and bridges the spatial and temporal gap between the Caucasus (around 1.85-1.78 million years ago)6 and southwestern Europe (around 1.2-1.1 million years ago)7,8. Our findings advance the hypothesis that Europe was colonized from the east, and our analysis of habitat suitability9 suggests that early hominins exploited warm interglacial periods to disperse into higher latitudes and relatively continental sites-such as Korolevo-well before the Middle Pleistocene Transition.

The Influence of Various Adhesive Systems and Polishing Methods on Enamel Surface Roughness after Debonding of Orthodontic Brackets: A Three-Dimensional In Vitro Evaluation

A slight alteration of the enamel surface is inevitable upon debonding of orthodontic brackets, adhesive removal, and finishing/polishing. The aim of this in vitro study was to compare two adhesives and three polishing methods by measuring enamel surface roughness using confocal laser scanning microscopy (CLSM). Brackets were bonded on 42 extracted human premolars using Transbond XT (Transbond group) or Fuji Ortho (Fuji group). After debracketing, adhesives were removed with a tungsten carbide bur, and surfaces were polished using Sof-Lex discs, a rotary brush with a prophylactic paste (Depural), or a prophylactic cup with two polishing pastes (n = 7 in each subgroup). Surface roughness (S_a, S_ku, S_q, and S_z) was measured using CLSM and compared before treatment (T₁), after debracketing and adhesive removal (T₂), and after polishing (T₃). The data were statistically analyzed using the Mann-Whitney U and Kruskal-Wallis tests with Bonferroni correction. The time required for adhesive removal was measured and compared using a two-sample t-test. Surface roughness at T₂ increased compared to T₁, but the difference was significant only for the Fuji group (p < 0.01). The time required to remove Transbond XT (94.1 ± 6.8 s) was significantly higher compared to Fuji (72.1 ± 5.9 s, p < 0.0001). Polishing with Sof-Lex discs resulted in lower surface roughness compared to T₁ (p = 0.018). Using Depural and polishing pastes showed no significant difference in surface roughness compared to T₁, except for a significant decrease in S_a and S_q for Transbond (p = 0.043) and in S_ku for Fuji (p = 0.018) after polishing with Depural. In conclusion, the removal of Transbond took significantly longer, but there were fewer residues of composite resin on the enamel surface. Sof-Lex discs decreased enamel roughness, whereas enamel morphology and roughness were similar to the pre-treatment state after polishing with polishing pastes.

Comparison of spontaneous eruption and modified closed eruption technique with palatal traction in alignment of impacted maxillary central incisor teeth

BACKGROUND

Central incisor impaction is a rare condition with potentially severe clinical and psychological implications for the patient. Treatment techniques vary according to the pretreatment situation and individual factors. The aim of this study was to compare the esthetic outcomes and treatment times between two different approaches.

MATERIALS AND METHODS

In this retrospective study, thirty-one consecutive patients (13 boys, 18 girls; average age 9.5 ± 2.3 years) with a total of 34 impacted permanent upper central incisors were included in the study. Patients were divided into two groups according to method of treatment. Group A comprised patients in whom spontaneous eruption occurred after space opening (n = 12), and Group B comprised patients in whom teeth showed no eruption and required treatment with a modified closed eruption method with palatally oriented traction (n = 19). Treatment time and esthetic outcomes were assessed and compared between groups.

RESULTS

The mean treatment time was 22.0 ± 6.7 months, and all teeth were successfully aligned. No statistically significant difference in average treatment time was found between groups in baseline characteristics (p > 0.05). The amount of attached gingiva was significantly smaller when compared to contralateral reference teeth in the closed eruption group (Group B; p = 0.03). However, no difference in amount of attached gingiva was found between both groups (p = 0.26). Additionally, no difference in the clinical crown length was found between groups (p = 0.27).

CONCLUSION

The closed eruption method with palatal traction directed at the peak of the alveolar crest provided results comparable to the physiologic tooth eruption.

The effect of different bonded retainer wires on tooth mobility immediately after orthodontic treatment

OBJECTIVES

This study aimed to compare the immediate influence of four commonly used retainer wires on tooth mobility following orthodontic treatment with fixed appliances.

MATERIALS AND METHODS

Eighty patients after orthodontic treatment were assigned to four study groups (n = 20 in each group). Groups were provided with directly bonded fixed retainers-0.0150″ (group A), 0.0175″ (group B), 0.016 × 0.022″ (group C), and 0.0215″ (group D). Tooth mobility was measured using the Periotest device at two times-after removal of fixed appliance (T1) and after bonding of the retainer (T2). Values of tooth mobility, 'Periotest values', were analysed between groups and compared with the physiologic tooth mobility in a control group of untreated patients (n = 65). Kruskal-Wallis H, Mann-Whitney U, Dunn's test, Fisher's exact test, and binary logistic regression tests were used to analyze the data.

RESULTS

Tooth mobility after orthodontic treatment was significantly increased. While canines remained within normal range of tooth mobility, values for incisors increased on average to the first degree of tooth mobility (slight mobility). Logistic regression analysis identified age as a significant predictor for increased tooth mobility (P = 0.032) with odds ratio 1.065 (95% CI 1.005-1.128), with mobility increasing with age. After bonding of the retainer in all four groups, the tooth mobility was reduced to values which were not significantly different form normal physiological values found in the control group (P > 0.05). There were no differences in the amount of change or in tooth mobility values at T2 between the different types of bonded retainers.

LIMITATIONS

Age of subjects in the control group was significantly higher than that in the study groups. An alternation method was used instead of randomization to distribute the four different types of retainers.

CONCLUSIONS

All of the retainer wires were able to successfully reduce the increased tooth mobility caused by orthodontic treatment to normal levels. The values of tooth mobility after placement of retainers were within the range of physiologic tooth mobility.

The effect of extended lactation on parameters of Wood's model of lactation curve in dairy Simmental cows

Objective

This study was focused on the estimation of parameters of Wood’s model and description of the lactation curve using the cows which were lactated over 24 months on the first lactation.

Methods

The database included 1,333 pure-bred dairy Simmental primiparous cows which lactated for 24 months (732 days). The initial dataset entering the procedure of assessment of parameters of Wood’s function included 35,826 milk yield records. Milk yield was recorded throughout lactation, with the earliest record taken on day 6 and the latest on day 1,348 of lactation. This dataset was used for the assessment of parameters a, b, c of Wood’s model using the non-linear statistical procedure. These parameters were estimated for different length of lactation. The assessed parameters were used for calculation of some characteristics of lactation curves.

Results

The lowest value of a parameter (15.2317) of Wood’s model of lactation curve was found out in lactations up to 305 days long, contrary to b and c parameters which were highest in those lactations (0.1029 and 0.0015, respectively). The maximum value of a parameter (17.4329) was found out in lactations up to 640 days long, unlike b and c parameters which were minimal in those lactations (0.0603 and 0.0010, respectively).

Conclusion

It can be concluded that the parameters of Wood’s model and the shape of lactation curve are changing with the growing number of milk yield records. Also, the assessed parameters revealed a significant milk production potential after 305 days of lactation.

Windbreak Efficiency in Agricultural Landscape of the Central Europe: Multiple Approaches to Wind Erosion Control

Windbreak is one of the key factors for making the agriculture systems successful through reduced wind erosion, improved microclimate, increased biodiversity, and production potentiality of timber and agricultural crops. Even though windbreak occupies only a small part of agricultural landscape, its advantages on the ecological and economical perspective are quite high. This study evaluated the effects of three windbreak types on the wind erosion control in relation to their structural diversities, wind-speed reduction, and optical porosities in the central part of the Czech Republic. Diversity in the windbreak was evaluated based on its species diversity, vertical structure, spatial pattern, and complexities. Wind speed was measured at the different distances on the leeward side of the windbreak and one station placed on the windward side as a control. Windbreak characteristics were described by terrestrial photogrammetry method using the values of optical porosity. The timber volume of the windbreaks with rich biodiversity species ranged from 224 to 443 m³ ha^-1height of the windbreak on the. Results of the windbreak efficiency showed significantly closer relationship between optical porosity and structural indices. The optical porosity significantly correlated with wind-speed reduction, especially in the lower part of the windbreak. A significant dependency of the windbreak efficiency on the tree dominant height was also observed for each windbreak type. The most significant effect on the wind-speed reduction in terms of structural indices had total diversity index and Arten-profile index describing vertical structures, which are recommended together with the optical porosity to evaluate the windbreak efficiency in controlling wind erosion.

The effect of cattle breed, season and type of diet on the fatty acid profile of raw milk

Abstract. The aim of the study was to determine the effect of cow breed, season and type of diet on the fatty acid (FA) profile of raw milk. A 2-year study was conducted on bulk milk samples collected from eight herds consisting of Czech Fleckvieh (CF, four herds) and Holstein (H, four herds) breeds. One half of the herds of each breed was grazed (G), while the other half was not (N). Samples were collected twice in winter (W) and twice in summer (S). Milk yield in CF (5385.50 kg) was lower than in H (7015.15 kg, P <  0.05). The effect of breed was found in odd-chain, branch-chain and hypercholesterolemic FAs (P <  0.05). The content of fat was lower in summer (S) than in winter (W), being 3.71 and 3.91 g 100 g−1, respectively (P <  0.05). The proportion of saturated and polyunsaturated FAs was lower in S than in W (P <  0.05). The content of monounsaturated FAs was higher in S (30.69 g 100 g−1) than in W (27.72 g 100 g−1, P <  0.05). Milk yield in grazing herds (G, 5197.50 kg) was lower (P <  0.05) than in non-grazing herds (N, 7203.75 kg). The sum of saturated and hypercholesterolemic FAs was lower and the sum of monounsaturated and odd-chain FAs was higher in G than in N (P <  0.05). Content of conjugated linoleic acid (CLA) and C18:3n3 was higher in G (0.93 and 0.64 g 100 g−1) than in N (0.42 and 0.39 g 100 g−1, respectively, P <  0.001).

Chemical, physical and technological properties of milk as affected by the mycotoxin load of dairy herds

Abstract. The aim of the study was to determine the impacts of different levels of mycotoxin load of Czech dairy herds on the larger scale of the milk indicators including milk physical and technological properties. During three subsequent years individual milk samples (IMSs) were collected from four herds of Czech Fleckvieh (C) and from four herds of Holstein cows (H). The IMSs were collected regularly twice in summer and twice in winter, resulting in a total of 936 IMSs. The feeding rations consisted mainly of conserved roughage and supplemental mixtures according to milk yield and standard demands. Samples of feedstuffs were collected at the same time as IMSs and were analysed for content of deoxynivalenol (DON), fumonisins (FUM), zearalenone (ZEA), aflatoxin (AFL), and T-2 toxin using enzyme-linked immunosorbent assay (ELISA) methods. Based on the mycotoxin load, herds were divided into three groups – Load 1 (negligible, n =  36), Load 2 (low, n =  192), and Load 3 (medium, n =  708). All feedstuff samples were positive for at least one mycotoxin. The most frequently occurring mycotoxins were FUM, DON, and ZEA. Relatively high incidence of AFL (56 % positive samples) was observed. The following milk indicators were influenced by the mycotoxin load of herds: fat, acetone (Ac), log Ac, pH, electric conductivity, alcohol stability, curds quality, curd firmness, whey volume, whey protein, non-protein nitrogen (NPN), urea N in NPN, fat ∕ crude protein ratio, and casein numbers on crude and true protein basis, respectively (P < 0.05). The overall level of mycotoxin load was relatively low, with no clear effect on milk characteristics.

Extended use of alanine irradiated in experimental reactor for combined gamma- and neutron-dose assessment by ESR spectroscopy and thermal neutron fluence assessment by measurement of (14)C by LSC

Gamma- and neutron doses in an experimental reactor were measured using alanine/electron spin resonance (ESR) spectrometry. The absorbed dose in alanine was decomposed into contributions caused by gamma and neutron radiation using neutron kerma factors. To overcome a low sensitivity of the alanine/ESR response to thermal neutrons, a novel method has been proposed for the assessment of a thermal neutron flux using the (14)N(n,p) (14)C reaction on nitrogen present in alanine and subsequent measurement of (14)C by liquid scintillation counting (LSC).

Effect of sires on wide scale of milk indicators in first calving Czech Fleckvieh cows

Abstract. The possible genetic impact of sire on cattle populations, herd milk yield and milk traits (fat and protein) have been described in the literature along with its impact on some milk indicators (MIs) as somatic cell count, urea and ketones. There is a dearth of information on the impact on a series of other MIs (physical, chemical, health, technological). The goal of this study was to assess the possible effect of sire on a wide range of MIs including technological properties in Czech Fleckvieh to suggest future possible breeding trends. A series of MIs (n=37) was investigated in individual milk samples (MSs). 191 effective daughters (MSs) were included. The sire groups (n=13) were well balanced in terms of herd, lactation stage and sampling season. Only sires with >5 daughters were ranked. A linear model of analysis variance with the fixed effects, sire and combined factor (herd × year × season) was used. 19 MIs as log count of streptococci in fermentation ability of milk (log FAM–CS), FAM–CS, log total fine microflora count in FAM (log FAM–TCM), FAM–TCM, solids non fat (SNF), iodine content, citric acid (CA), titration acidity in FAM, lactose (L), crude protein (CP), true protein (TP), casein (CAS), dry matter, Mg and P content, milk alcohol stability, electrical conductivity (EC), titration acidity, casein numbers (for CP and TP), log count of lactobacilli in FAM (log FAM–CL), FAM–CL and pH in FAM were influenced by sire (P<0.05). However SNF, CA, L, CAS and perhaps EC could be newly reflected as information for genetic improvement of dairy cattle with connection to dairy milk recovery and cow health. CA (10.08±1.92 mmol×l−1) deserves special attention. The model variablity explanation moved from 6.97 (SCC) over 29.51 (CA) to 48.32 % (pH) for MIs. This is one of few studies to assess the impact of sire over a wide range of MIs and the results warrant careful evaluation and further study.

Relationships of sire breeding values and cutting parts of progeny in Czech Fleckvieh bulls

Abstract. The aim of this study was to assess the effect of the meat yield breeding values of sires on highly valued parts of carcasses in their progeny. The study was carried out on Czech Fleckviehs, a breed dual purpose milk-beef production. Cutting parts evaluated were: round, strip loin and tender loin (first-class meat); rib, shoulder blade (boneless), fore shank, flank, chuck roll + neck (second-class meat) and separable fat. The correlation analysis showed significant negative relationships only for the relative breeding values of trading classes and the rib (r=−0.2079); relative breeding values of net daily gain with strip loin (r=−0.2433). Although strip loin is an important first-class meat cut, the correlation is rather low. Correlations between other meat cuts with breeding values were non-significant. The correlation between meat cuts and age showed the same pattern as correlations between meat cuts and weight at slaughter. Significant negative correlations were found between first-class meat and increasing age (r=−0.1979) and weight (r=−0.2884). In contrast, for second-class meat there were positive correlation with increasing age and weight (r=0.3489 for age, r=0.4495 for weight). This also corresponds with the correlation between age or weight and specific first-class meat cuts (tender loin r=−0.2804, r=−0.3413, strip loin r=−0.3710, r=−0.2012) and second-class meat (sep. fat r=+0.2360, r=+0.2951, r for correlation with age and weight respectively). Based on the calculations of canonical analysis 27.75 % explained variability was found for variables relative breeding value of net daily gain (RBVndg), relative breeding value of trading class (RBVtc), age and weight using a linear combination of variables for individual cuts. At the same time, 14.25 % explained variability was found for cut variables which can be expressed using linear combinations of RBVndg, RBVtc, age and weight.