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The important role of facial elements (hooked beak and conspicuous eye colour) in the recognition of avian predators has been repeatedly demonstrated. However, no attention has yet been paid to the importance of their canonical configuration i.e., the relative position of the eyes and beak. In our study, we tested the ability of untrained wild tits to recognise a dangerous predator (a sparrowhawk) with inverted eye and beak positions (invert dummy) and with one eye above and one below the beak (inline dummy) in aviary experiments. A dummy of a sparrowhawk with its head devoid of eyes and beak (empty dummy) served as a baseline alongside dummies of an unmodified sparrowhawk and a pigeon (as a harmless control). The experiment was carried out in two variants, with the complete dummy of the sparrowhawk visible and with the body of the dummy hidden in the bushes, from which only the head was visible. The tits showed no more fear towards the eyeless and beakless dummy than they did towards the pigeon. Towards the dummy with the modified configuration, the tits showed no less fear than towards the unmodified sparrowhawk, but in the case of the variant with an eye above and below the beak, their behaviour was different and can be interpreted as increased fear but also as surprise. Thus, the tits perceive a disturbance in the configuration of the predator faces, but do not show unambiguous signs of holistic processing i.e., impaired recognition of the inverted face.

Aims: The main aim of our study was to demonstrate the difference in endothelial cell density between a group of keratoconus contact lens users and non-contact lens users (without keratoconus). Material and methods: In our study we had data from 96 subjects with an average age of 40.5 ±14.05 years. For the purposes of our study, we worked with each eye separately for each subject (n = 192). Keratoconus (research group) was diagnosed in 97 eyes. The mean age of the patients in the research group was 41.9 ±10.6 years. Keratoconus was not diagnosed in the remaining 95 eyes (control group). The mean age of the patients in the control group was 39.5 ±16.6 years. In the keratoconus group, the patients wore hard contact lenses (HCL) in a total of 43 eyes, hybrid contact lenses (HbCL) in 48 eyes and soft contact lenses (SCL) in 6 eyes. The average total period of contact lens use in the research group was 10.6 ±2.36 years. Results: The average number of endothelial cells in the research group was 2607.11 ±298.45 cells per mm2. The average number of endothelial cells in the control group was 2831.94 ±523.51 cells per mm2. We tested these two variables using a T-test, which showed a statistically significant difference (p

The red-backed shrike (

Background During recognition process, multiple parameters of the encountered stimulus may play a role. Previous studies with wild birds identified the importance of several salient features (e.g., eyes, beak, prominent elements of colouration) which birds use to recognise other bird species, such as predators or nest parasites. In the present study, we observed the responses of passerines visiting winter feeders to stimuli in the form of dummies of Eurasian sparrowhawk which were modified in body size and/or colouration but always carried the salient features of raptors (hooked beak, talons) and one species-specific feature of the sparrowhawk (yellow eyes). In the vicinity of a feeder, we placed a dummy of an unmodified sparrowhawk, life-sized sparrowhawk with pigeon, great tit, or robin colouration, a small, great tit-sized sparrowhawk dummy with unmodified or pigeon colouration, or an unmodified pigeon dummy, which functioned as a harmless control. Then we measured how it affected the number of visits. Results We found that birds were less afraid of small dummies regardless of their colouration than they were of life-sized raptor dummies or even the pigeon dummy. This contrasts with the results of a previous laboratory experiment where great tits’ reaction to small dummies was comparably fearful to their response to life-size dummies. In our experiment, birds were also not afraid of life-sized dummies with modified colouration except for a robin-coloured dummy, which caused an equally significant fear reaction as an unmodified sparrowhawk dummy. It is likely that this dummy resembled the colouration of a male sparrowhawk closely enough to cause this effect. Conclusions Based on our observations, we conclude that birds use contextual features to evaluate the size of other birds. Distance and familiar reference points seem to play an important part in this process.

Birds are strongly motivated to recognize various predators to secure survival and reproductive success. Thus, predator recognition provides a useful tool for the investigation of the process of discrimination and categorization in non-trained animals. The most important role in this process is usually attributed to the prominent unique features shared by all members within the wider category of predators (sharp teeth or beaks, claws, talons and conspicuous eyes). However, birds are also able to discriminate between particular predator species according to their species-specific features (based mainly on colouration). We manipulated general raptor salient features (hooked beak, talons with claws and eyes with supraorbital ridges) and/or species-specific plumage colouration on the dummy of a Eurasian kestrel (Falco tinnunculus) to investigate their importance in the recognition process of the red-backed shrikes (Lanius collurio) during nest defence. We showed that the presence of general raptor salient features is necessary for the recognition of a predator. The kestrel dummy with natural species-specific colouration with altered raptor salient features was treated by shrikes as a harmless bird. Nevertheless, pronounced changes in colouration also prevented successful recognition of the dummy as a kestrel, even when raptor salient features of a raptor were present.

Aims: Metamorphopsia is important symptom of macular disease. The most common simple detection method of metamorphopsia is Amsler grid. Usually it is used monocularly with best correction for near. Patient should evaluate grid deformation and describe position of the deformity. This method is based on qualitative principle. For quantitative evaluation we can use Software D Chart (Thomson Software Solution). This instrument enables evaluate degree and position of the metamorphopsia in central visual field. Our goal was to establish M-score values in group of young healthy subjects without correction (M-score natural), with cylindrical spectacle lens (M-score SL) and in group of patients with age related degeneration (M-score ARMD). Objects and Methods: We had 33 probands divided into 2 samples. The first sample contains 15 young probands with average age 23 years without any eye pathology. The second sample contains 18 patients with ARMD (7 with dry form and 11 with wet form). In our study we used software D Chart (Thomson Software Solution). This software was use in Acer PC with touchable screen. We note total M-score in right eye of all probands. Level for statistic evaluation was set on p = 0.05. Results: Natural M-score values for young probands was: median 0, minimum 0, maximum 2.3. With cylindrical lens we got these values: median 25.2, minimum 3.6, maximum 41.6. In second sample with probands suffer from ARMD we got these values: median 0.8, minimum 0, maximum 29.4. Wilcoxon non-parametric test was used for statistical evaluation. We proved statistically significant difference between all variables. M-score natural vs. M-score SL showed p < 0.001, M-score natural vs. M-score ARMD showed p = 0.04 and M-score SL vs. M-score ARMD showed p < 0.001. Conclusion: Our study showed statistically significant differences between variable M-score natural, M-score SL and M-score ARMD. We found that printed Amsler grid as well as its digital modification D Chart are suitable for determining metamorphopsia in central visual field. The main advantage of D Chart is quantitative evaluation of the test with M-score and digital registration of retinal changes during patient´s follow up.

Eavesdropping on heterospecific alarm calls is a crucial source of information for many species (including corvids) and it is effective especially if these species form mixed-species flocks, have a similar spectrum of predators, and share habitat. Previous research on wild common ravens (Corvus corax) has shown that they react to the jackdaws’ alarm call. We tested their responses to the heterospecific alarm calls of various bird species differing in familiarity and taxonomical relatedness to ravens. Two other corvid species (the blue jay Cyanocitta cristata and the European jay Garrulus glandarius) and two non-corvids (the black-headed gull Chroicocephalus ridibundus and the laughing gull Leucophaeus atricilla) were presented. We played back the tested alarm calls to free-ranging ravens at a feeding site and observed the ravens’ responses to particular stimuli. We observed three behavioural responses made by the tested ravens: flying away, freezing (ceasing to move and crouching on the ground), and vigilance (observing the surroundings). The ravens responded to the Eurasian jay alarm call by freezing and flying away and to the blue jay alarm call by freezing and vigilance. The laughing gull alarm call induced mostly vigilance and the black-headed gull alarm call did not elicit any reaction. The responses to the alarm calls of both jays were similar to the responses to the playbacks of conspecific alarm calls, used as control (as well as to the response to a jackdaw alarm call from the previous study), which may point to the existence of a specific corvid characteristic in their alarm calls. The response to the alarm calls of both American species included vigilance, which suggests an uncertainty about the meaning of the call.

Nesting birds often respond to human disturbance as to a predatory act. In the case of the high Arctic, the disturbance of incubating birds may bring further complications due to egg cooling. In addition, it is assumed that birds in the high Arctic are not shy and do not respond to human presence fearfully. We tested how quickly the Arctic terns (Sterna paradisaea) nesting in two colonies in Svalbard return to the nest after human disturbance. One colony was situated inside a town where the terns were regularly harassed by human presence. The second colony was on a glacial foreland where breeding terns have limited experience with humans. We found that terns without frequent experience with humans returned to the nest about 5 min after disturbance, while urban terns habituated to human presence returned within a few tens of seconds. The urban terns in this way likely solve the risk of spending too much time off the nest, which could lead under the conditions of the high Arctic to the stopping of embryogenesis. Terns from a remote colony do not show lower hatching success of their eggs than the urban ones, however, incubation and the whole population of terns could be threatened when there is more frequent disturbance by researchers or tourists.

Práce se zabývá korelací výsledků nízkoteplotních zkoušek asfaltových směsí s výsledky nízkoteplotních zkoušek nejčastěji používaných asfaltových pojiv. Vlastnosti používaných materiálů v teplotách, které se s měnícím klimatem stále častěji přibližují kritickým hodnotám, jsou stále více aktuálním tématem, které nesmí být opomínáno. Snahou této práce je poukázat na míru v jaké je možné ovlivnit tyto vlastnosti pomocí různých pojiv. Pro tento účel byly provedeny zkoušky, kterými jsou mimo jiné určení kritické teploty zkouškou nízkoteplotních vlastností s rovnoměrným řízeným poklesem teploty (TSRST), kritického bodu lámavosti dle Fraase a průhybového trámečkového reometru. The paper deals with results of tests for low temperature properties of asphalt mixtures in correlation with results of tests on low temperature properties of the bitumen used in those. Properties of materials used in temperatures, which with changing climate keep approaching the critical value, are still very current topic, which cannot be overlooked. The aim of this paper is to point out the extent in which we can affect these properties with different binders. For this purpose, low temperature tests were carried out which include the thermal stress restrained specimen test to set critical temperature of asphalt mixture, Fraasse breaking point and the bending beam rheometer.

Despite object categorization being an important ability for the survival of wild animals, the principles behind this ability have been only scarcely studied using wild-ranging, untrained animals. Reiterating our previous study undertaken with wild-ranging titmice on winter feeders (Nováková et al. Behav Process 143:7-12, 2017), we aimed to test two hypotheses of object recognition proposed by animal psychology studies: the particulate feature theory and recognition by components in the methodological paradigm of nest defence. We tested whether the parents of the red-backed shrike (Lanius collurio) recognize the dummies of the common kestrel (Falco tinnunculus), which is a potential predator of large chicks or fledglings, as a threat in case when their body parts are scrambled. The kestrel dummy was presented with the head at the top, in the middle, and at the bottom of the body. We showed that the shrikes did not consider dummies of a kestrel with an inappropriately placed head as a threat to the nest and attacked it equally scarcely as the harmless control. These results support the theory of recognition by components, presuming that the mutual position of body parts is essential for appropriate recognition of the object. When the body parts were scrambled, most of shrikes were not able to identify the kestrel in such an object despite all local features (eye, beak, colouration, and claws) being present. Nevertheless, shrikes did not consider the scrambled dummies as completely harmless, because they fed their chicks in their presence significantly less often than in the presence of harmless control.

The study examines the sensitivity and specificity of spectral OCT in detecting early glaucoma. The aim was to evaluate data obtained by RNFL analysis in 4 observed quadrants and to compare it with the resulting diagnosis of glaucoma neuropathy determined subsequently on the basis of changes in the visual field. This concerns a retrospective study numbering 31 probands who underwent OCT examination at our centre in the period from 2008 to 2017. Test statistics demonstrated sensitivity of OCT examination (specific RNFL analysis) of 63.64% and specificity of 90%. The used ROC (receiver operating characteristic curve) test showed an AUC (area under curve) value of 0.734 on a statistically significant level of p = 0.0097. We therefore found that the instrument Spectral OCT SLO, with the aid of RNFL analysis, was effective in determining probands in whom development of glaucoma pathology was subsequently confirmed.

1. Few, if any, experimental tests have demonstrated the anti‐predator protection of the developmental stages of ladybirds (Coleoptera: Coccinellidae) against vertebrates, despite the fact that both the visual appearance of ladybirds and the content of defensive compounds fulfil the definition of an aposematic prey. 2. In this study, avian predators of three species were confronted with fourth‐instar larvae and pupae of the harlequin ladybird (Harmonia axyridis) – a large, conspicuous, and toxic ladybird species. 3. The selected predators differed in their individual experience and attitude to ladybirds. Wild‐caught great tits (Parus major) strongly avoided attacking ladybirds in general, whereas wild‐caught tree sparrows (Passer montanus) were willing to include ladybirds in their diet. Domestic chicks (Gallus gallus domesticus) have never been confronted with ladybirds but usually show avoidance of aposematic signals. In this study, great tits and domestic chicks avoided both developmental stages, but in the case of chicks the avoidance had to be learned over the course of repeated encounters. Sparrow avoidance was significantly lower, with more than one‐third of the prey being attacked and eaten. 4. The protection of both developmental stages of ladybirds is similar to adults, despite substantially different visual appearance.

In this paper, we present results of long-term stability tests of a low-loss (

Red-backed shrikes (Lanius collurio) show a substantial variability in their nest defence behaviour, which usually follows the rules of optimal parental behaviour, vigorously attacking egg and chick predators and only passively guarding against harmless animals. Nevertheless, shrikes hesitate to attack the Eurasian magpie (Pica pica), which specializes in plundering passerine nests. Our previous studies have suggested that this behaviour may be the result of an alternative defence strategy, relying on nest crypsis. To test this hypothesis, at the shrike nests, we presented a magpie dummy associated with playbacks drawing the predators' attention to the presence of the nest. We predicted that the presentation of a magpie dummy associated with shrike alarm calls moves the parents to action, causing them to chase the magpie away from the nest. We showed that the presence of a magpie dummy associated with shrike alarm calls elicits a significantly more active response in shrike parents compared to a magpie dummy associated with neutral song. Parents actively moved around the dummy and produced alarm calls; nevertheless, most of the tested pairs hesitated to attack the dummy. We may conclude that the low nest defence activity of shrike parents towards magpie dummy was partly the result of an alternative strategy, which may be cancelled out by alerting the predator to the location of the nest; nevertheless, shrikes seem to be afraid of the magpie and hesitate to attack it physically.

The formation of defects and imperfections in the soldering process can have many causes, which primarily include a poorly setup technological process, inappropriate or inappropriately used materials and their combinations, the effect of the surroundings and design errors. This chapter lists some examples of errors that can occur in soldering, while review is devoted to selected defects: non-wettability of the solder pads, dewetting, wrong solder mask design, warpage, head-in-pillow, cracks in the joints, pad cratering, black pad, solder beading, tombstoning, dendrites, voids, flux spattering from the solder paste, popcorning and whiskers.

Purpose: We usually use objective and subjective methods for examination of the eye astigmatism in optometry, respectively ophthalmology. Objective methods enable to measure sphere-cylindrical refraction of the eye. If we want to prescribe new glasses or contact lenses we usually use subjective methods. The aim of this study was to measure sensitivity and specificity of some subjective and objective methods for examination of the eye astigmatism. We supposed that automatic objective refraction will be the most exact method so we choose this method as the reference method. For comparison we chose subjective methods Jackson crossed cylinders (JCC), fogging method (FM) and objective method Spot Vision Screener (SVS, Welch Allyn). Materials and methods: We had in total 30 subjects with average age 23 years (SD 1 year) in our study. We made each measurement per eye separately and it was independent measurement so we could use measurement from each eye (n = 60). Each eye was firstly measured by subjective method FM, followed by JCC method and finally was use objective method Spot Vision Screener (SVS, Welch Allyn). Measurement with objective instrument TRK-1P (TOPCON) was use as reference measurement. The significance level was set at p = 0.05. Results: In variable FM we measured sensitivity 76.2 % and specificity 66.7 %. Criterion for positive finding was -0.25 D. Result was statistically significant on level p < 0.001. In variable JCC we measured sensitivity 95.2 % and specificity 66.7 %. Criterion for positive finding was -0.25 D. Result was statistically significant on level p < 0.001. In variable SVS we measured sensitivity 47.6 % and specificity 94.4 %. Criterion for positive finding was -0.75 D. Result was statistically significant on level p < 0.001. Direct comparison of all methods showed statistically important difference between techniques JCC and FM (p = 0.0095). In other method we did not find statistically important difference (FM vs. SVS, p = 0.526 and JCC vs. SVS, p = 0.105). Conclusion: All subjective and objective techniques were statistically significant in detection of eye astigmatism. Comparison of ROC curves showed statistically significant difference between FM and JCC technique. The JCC method showed the highest sensitivity, whereas SVS highest specificity.

Birds are strongly motivated to recognize various predators to secure survival and reproductive success. Thus, predator recognition provides a useful tool for the investigation of the process of discrimination and categorization in non-trained animals. The most important role in this process is usually attributed to the prominent unique features shared by all members within the wider category of predators (sharp teeth or beaks, claws, talons and conspicuous eyes). However, birds are also able to discriminate between particular predator species according to their species-specific features (based mainly on colouration). We manipulated general raptor salient features (hooked beak, talons with claws and eyes with supraorbital ridges) and/or species-specific plumage colouration on the dummy of a Eurasian kestrel (Falco tinnunculus) to investigate their importance in the recognition process of the red-backed shrikes (Lanius collurio) during nest defence. We showed that the presence of general raptor salient features is necessary for the recognition of a predator. The kestrel dummy with natural species-specific colouration with altered raptor salient features was treated by shrikes as a harmless bird. Nevertheless, pronounced changes in colouration also prevented successful recognition of the dummy as a kestrel, even when raptor salient features of a raptor were present.

The main goal of our study was to prove short-term objective influence of near addition and relieving prism on accommodative and vergence facility in group of young healthy persons. Further, we wanted to prove objective and subjective difference between two types of soft contact lenses during working with digital device. We had in total 37 subjects in our study. The first group contained 37 subjects with average age 23 years without important eye pathology. The second group contained 8 subjects with the same average age without important eye pathology. In the first group of subjects, we measured binocular accommodative facility (BAF) and binocular vergence facility (BVF) with and without addition 1 D and with and without relieving prism 2 pD BO at working distance 45 cm. In the second group, we evaluated BAF, BVF and standardized questionnaire (Computer Vision Syndrome Questionnaire - CVS-Q, Sequí M. 2015) during usage of two types of soft contact lenses. The first type of contact lenses (type 1) contained relieving prism for PC working and type 2 was soft contact lens with aspheric design. In the first group of subjects, we measured these values: BAF without addition = 12.78 cpm, BAF with addition = 11.57 cpm, BVF without prism = 12.32 cpm, BVF with prism = 11.59 cpm. In the second group of subjects, we measured with contact lens type 1 these values: BAF = 12.13 cpm, BVF = 13.63 cpm and questionnaire score 9.43 points. With contact lens type 2 we measured BAF = 11.75 cpm, BVF = 11.63 cpm and questionnaire score 12.86 points. We proved statistically important different between two variable only in the first group between BAF with and without addition and BVF with and without relieving prism. In conclusion, we found statistically important decrease in variable BAF and BVF with usage of addition and relieving prism. We found that neither addition nor prism have positive influence on increase of BAF and BVF. Subjects in second group had higher BAF and BVF values with both types of contact lenses in comparison with natural values. We found that with contact lens type 1 (with addition) subjects had higher BAF and BVF values in comparison with contact lens type 2 (aspheric). Subjects with contact lens type 1 had also lower (better) questionnaire score, i.e. 9.43 versus 12.86 point. Key words: Digital eyestrain syndrome, accommodative and vergence facility, addition, relieving prism.

Heterospecific alarm calls are typically found in situations where multiple species have a common predator. In birds, they are particularly common in mixed mixed‐species flocks. In species with highly developed social and cognitive abilities like corvids, there is the potential for differential responses to heterospecific vs. conspecific calls according to the riskiness of the habitat. We tested the responses of free‐ranging ravens (Corvus corax) to conspecific alarm calls and compared them to heterospecific alarm calls of jackdaws (Corvus monedula). We observed the proportion of ravens leaving the feeding site after the con‐ or hetero‐specific playback was presented in a situation of low threat (wild boar—Sus scrofa enclosure) and high threat of predation (wolf—Canis lupus enclosure). We show that ravens responded to conspecific calls more intensively at the wolves than at the wild boar, but the response to conspecific calls was in both enclosures stronger than to the control (great tit—Parus major song). The response to the heterospecific alarm was also stronger in the wolves’ enclosure, but it did not differ from control in the wild boar enclosure. These findings suggest that ravens are aware of the meaning of the jackdaw alarm calls, but they respond to it only in a situation of high predatory threat (wolves are present). In the wild boar enclosure, the ravens probably consider jackdaws warning against some other predator, very probably harmless to ravens. This interpretation requires further testing, as both enclosures differ also in respect to other parameters like food quality and shelter availability.

Purpose The purpose of this paper is to increase the reliability of manufactured electronics and to reveal reliability significant factors. The experiments were focused especially on the influence of the reflow oven parameters presented by a heating factor. Design/methodology/approach The shear strength of the surface mount device (SMD) resistors and their joint resistance were analyzed. The resistors were assembled with two Sn/Ag/Cu-based and one Bi-based solder pastes, and the analysis was done for several values of the heating factor and before and after isothermal aging. The measurement of thickness of intermetallic compounds was conducted on the micro-sections of the solder joints. Findings The shear strength of solder joints based on the Sn/Ag/Cu-based solder alloy started to decline after the heating factor reached the value of 500 s · K, whereas the shear strength of the solder alloy based on the Bi alloy (in the measured range) always increased with an increase in the heating factor. Also, the Bi-based solder joints showed shear strength increase after isothermal aging in contrast to Sn/Ag/Cu-based solder joints, which showed shear strength decrease. Originality/value The interpretation of the results of such a comprehensive measurement leads to a better understanding of the mutual relation between reliability and other technological parameters such as solder alloy type, surface finish and parameters of the soldering process.