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Spherical nanoparticles (NPs) of cadmium and lead sulfides (diameter 37 ± 5 and 24 ± 4 nm, respectively) have been found to be cytotoxic for HL-1 cardiomyocytes as evidenced by decrease in adenosine triphosphate–dependent luminescence. Cadmium sulfide (CdS)-NPs were discovered to produce a much greater cytotoxic impact than lead sulphide (PbS)-NP. Given the same dose range, CdS-NP reduced the number of calcium spikes. A similar effect was observed for small doses of PbS-NP. In addition to cell hypertrophy under the impact of certain doses of CdS-NP and PbS-NP, doses causing cardiomyocyte size reduction were identified. For these 3 outcomes, we obtained both monotonic “dose–response” functions (well approximated by the hyperbolic function) and different variants of non-monotonic ones for which we found adequate mathematical expressions by modifying certain models of hormesis available in the literature. Data analysis using a response surface linear model with a cross-term provided new support to the previously established postulate that a diversity of types of joint action characteristic of one and the same pair of damaging agents is one of the important assertions of the general theory of combined toxicity. © The Author(s) 2020.

Nanoparticles of metals and their oxides (Me-NPs) are of special interest in the light of health risks assessment and management, because, along with engineered Me-NPs, there exists usually a substantial fraction of nanoscale ("ultrafine") particles of the same substances within the particle size distribution of condensation aerosols generated by arc-welding, metallurgical, and some chemical technologies. The nonspecific responses of the organism to the impact of Me-NP included: changes in the cytological and some biochemical characteristics of the bronchoalveolar lavage fluid caused by the deposition of particles in the lower airways, various manifestations of systemic toxicity including significant damage to the liver and kidneys, moderate neurological disturbances associated with possible penetration of Me-NP into the brain from the blood as well as from the nasal mucous membrane along the olfactory pathway, a paradoxically low manifestation of pulmonary pathology due to low chronic retention of nanoparticles in the lungs, and a genotoxic effect on the organism level. The toxicity and even genotoxicity of Me-NPs can be significantly attenuated by adequately composed combinations of some bioactive agents in innocuous doses. © Published under licence by IOP Publishing Ltd.

Aim: Many medical universities rely these days on trained student tutors to enable faculty-wide undergraduate ultrasound training. However, there is neither consensus on an optimal method nor any developed and agreed standard in the training of these student tutors. Usually internships and courses are employed which have both a specific set of advantages and disadvantages. We conducted a prospective quasi-randomized study of assess the effects of three types of tutor training on the resulting improvement in scanning skills of their tutees.Methods: Three batches of student tutors were trained by a course only (C-group), by an internship only (I-group) or by a course and an internship (CI-group). The respective gains in ultrasound scanning skills of the tutees were measured prospectively. A total 75 of the 124 5th year medical students (60.5%) who attended the mandatory ultrasound course completed both pre- and post-exams on a voluntary basis. Within a limit of eight minutes and three images, they were asked to depict and label a maximum of 14 anatomical structures. Two blinded raters independently awarded two points for each label with an identifiable structure and one point for each label with a possibly identifiable structure.Results: In all three groups, the tutees improved significantly by more than doubling their pre-score results and comparably (Gains: C-group 9.19±5.73 points, p<.0001, I-group 9.77±4.81 points, p<.0001, CI-group 8.97±5.49 points, p<.0001).Conclusion: Student tutors, who were trained with a course or an internship or a course and an internship could teach scanning skills to 5th year medical students very effectively and with similar success., Ziel: Viele medizinische Universitäten bieten heutzutage mit der Hilfe von ausgebildeten studentischen Tutoren eine fakultätsweite Ultraschall-Grundausbildung an. Es gibt jedoch weder einen Konsens über eine optimale Methode noch einen verbindlichen Standard für die Ausbildung dieser studentischen Tutoren. In der Regel werden zur Ausbildung Praktika und Kurse eingesetzt, die sowohl spezifische Vor- als auch Nachteile aufweisen.Wir führten eine prospektive, quasi-randomisierte Studie durch, um die Auswirkungen von drei Arten von Tutorentraining auf die daraus resultierende Verbesserung der Scanfähigkeiten ihrer Tutees zu bewerten.Methoden: Drei Gruppen studentischer Tutoren wurden nur durch einen Kurs (K-Gruppe), nur durch eine Famulatur (F-Gruppe) oder durch einen Kurs und eine Famulatur (KF-Gruppe) geschult. Die jeweiligen Zuwächse an Scanfähigkeiten der Tutees wurden prospektiv gemessen. 75 der 124 Medizinstudenten im fünften Studienjahr (60,5%), die den curricularen Ultraschallkurs besuchten, haben sowohl den Vor- als auch den Nachtest auf freiwilliger Basis absolviert. Innerhalb von acht Minuten sollten maximal 14 anatomische Strukturen in drei Bildern dargestellt und beschriftet werden. Zwei verblindete Bewerter vergaben unabhängig voneinander zwei Punkte für jede sicher identifizierbare Struktur und einen Punkt für jede möglicherweise identifizierbare Struktur.Ergebnisse: In allen drei Gruppen verbesserten sich die Tutees signifikant, indem sie ihre Ergebnisse von vor dem Unterricht mehr als verdoppelten (Zuwachs: K-Gruppe 9,19±5,73 Punkte, p<0,0001; F-Gruppe 9,77±4,81 Punkte, p<0,0001; KF-Gruppe 8,97±5,49 Punkte, p<0,0001).Fazit: Studentische Tutoren, die mit einem Kurs oder einer Famulatur oder einem Kurs und einer Famulatur geschult wurden, konnten Medizinstudenten im 5. Jahr sehr effektiv und mit vergleichbarem Erfolg Scanfähigkeiten vermitteln.

The influence of the nest location and the placement of nipple drinkers on nest use by laying hens in a commercial aviary was assessed. Twenty pens in a laying hen house were equipped with the same commercial aviary system, but the pens differed in the nest location and the placement of nipple drinkers. Nests were placed along the walls in 10 pens, and nipple drinkers were installed in front of the nests in 5 of these pens. The other 10 pens were equipped with nests placed on a tier within the aviary (integrated nests). Nipple drinkers were installed in front of the nests in 5 of these pens. A total of 225 Lohmann Selected Leghorns were housed per pen. The hens were offered 4 nests per pen: 2 facing the service corridor of the laying hen house and 2 facing the outdoor area. The numbers of nest eggs and mislaid eggs were counted daily per pen. At 25, 36, and 43 wk of age, the nest platforms were videotaped and the behavior of laying hens in front of the nests was analyzed. The nest location affected the stationary and locomotive behaviors in front of the nests. Hens in front of the integrated nests and the nests with drinkers displayed more stationary behaviors than hens in front of wall-placed nests or nests without drinkers. No difference in the number of nest eggs could be detected, but the integration of the nests inside the aviary led to a more even distribution of hens while nest searching. In the pens with wall-placed nests, significantly more hens laid eggs in the nests at the wall near the service corridor than at the wall near the outdoor area. Due to this imbalance, crowding in front of the preferred nests occurred and pushing and agonistic interactions on the nest platforms were significantly more frequent. Placement of nipple drinkers in front of nests had no effect on the number of eggs laid in those nests

A systematic review of investigations on productivity, mortality and cannibalism of laying hens housed in aviaries is presented. In Part One we reviewed the studies that compared these parameters between laying hens housed in aviaries and in conventional cages. In Part Two we investigated the relative impact of strain, beak trimming and rearing condition on productivity and mortality in aviaries. The comparative analysis revealed that aviary hens consumed 3.0 % more food than caged hens, and food conversion was 6.7 % higher in aviaries than in cages. On the other hand, the mortality rate and cannibalism rate did not differ significantly between the two housing systems. The analysis of causes of variation in productivity, mortality rate and cannibalism rate in aviaries revealed a strong effect of strain. Beak trimming was associated with a reduced prevalence of cannibalism rates but had no effect on overall mortality. It also reduced egg weight and food consumption. Early access to litter during the rearing period had a positive effect on egg weight; egg mass, food conversion and mortality rate. In conclusion, we found a slightly reduced productivity of aviaries in relation to cages although the mortality rates and the prevalence of cannibalism did not differ between these housing systems. To further improve productivity and reduce mortality of hens housed in aviaries we recommend the choice of suitable strains and the implementation of improved rearing conditions including early access to litter

In Switzerland eggs have not been produced in battery cages since January 1992. During the 10 year period from 1981 farmers replaced their battery cages with deep litter, aviary and grid-floor systems and modified cages. However, the cages used to replace the conventional battery cages and most of the grid- floor systems did not fulfil the requirements of the Swiss Welfare Act and they were not permitted to be advertised or sold thereafter. Sixteen years after the ban on battery cages, the Federal Veterinary Office has undertaken a survey to determine how laying hens are kept in Switzerland and how the alternative systems have fared. The survey was carried out on 96 randomly chosen farms with at least 500 hen places to find out more about the housing conditions, management processes, status and performance of hens. The results show that aviaries are very common in Switzerland (65% of the laying hens) and that the laying performance in these systems is significantly higher than that in grid- floor systems and similar to that in battery cages. Provision of a protected outdoor area is a valuable benefit. To be successful with aviary systems it is necessary for pullets to spend the rearing period under similar housing conditions

Several studies have shown a high prevalence of keel bone deformities in commercial laying hens. The aim of this project was to assess the effects of perch material, a vitamin D feed additive (25-hydroxyvitamin D3; HyD, DSM Nutritional Products, Basel, Switzerland), and genetics on keel bone pathology. The study consisted of 2 experiments. In the first experiment, 4,000 Lohmann Selected Leghorn hens were raised in aviary systems until 18 wk of age. Two factors were investigated: perch material (plastic or rubber-coated metal) and feed (with and without HyD). Afterward, the hens were moved to a layer house with 8 pens with 2 aviary systems. Daily feed consumption, egg production, mortality, and feather condition were evaluated. Every 6 wk, the keel bones of 10 randomly selected birds per pen were palpated and scored. In the second experiment, 2,000 Lohmann Brown (LB) hens and 2,000 Lohmann Brown parent stock (LBPS) hens were raised in a manner identical to the first experiment. During the laying period, the hens were kept in 24 identical floor pens but equipped with different perch material (plastic or rubber-coated metal). The same variables were investigated as in the first experiment. No keel bone deformities were found during the rearing period in either experiment. During the laying period, deformities gradually appeared and reached a prevalence of 35% in the first experiment and 43.8% in the second experiment at the age of 65 and 62 wk, respectively. In the first experiment, neither HyD nor the aviary system had any significant effect on the prevalence of keel bone deformities. In the second experiment, LBPS had significantly fewer moderate and severe deformities than LB, and rubber-coated metal perches were associated with a higher prevalence of keel bone deformities compared with plastic perches. The LBPS laid more but smaller eggs than the LB. Again, HyD did not affect the prevalence of keel bone deformities. However, the significant effect of breed affiliat