Milk ejection solicitations and non-nutritive nursings: an honest signaling system of need in domestic pigs?

In domestic pigs, about 20% of nursing episodes end without milk transfer (non-nutritive nursings, NNNs). The function of NNNs has not been satisfactorily explained yet. Here, we suggest that NNNs may be a part of an honest signaling system that enables the sow to provide more frequent nutritive nursings (NNs) to those litters that can prove their need through exceptionally frequent milk ejection solicitations. We further propose that the system is kept stable through the accelerating costs attached to the solicitation in the form of NNNs. Based on this hypothesis, we predicted that (P1) with an increasing number of all nursings (ALL = NNNs + NNs) the number of NNs should increase and that (P2) with an increasing number of ALL the proportion of NNNs should increase. We tested P1 and P2 using a meta-analysis applied to data from eight studies that recorded the number of NNs and NNNs in domestic pigs. We confirmed both P1 (NNs increasing with ALL) and P2 (proportion of NNNs increasing with ALL). In combination, these results show a steeply accelerating cost of each additional nutritive nursing that piglets instigate. This cost sets limits to the piglets' ability to solicit higher maternal investment through more frequent nursing solicitations.     

Environmental monitoring within the Slovak Republic

In the Slovak Republic (SR) there has not been a complete and coordinated monitoring system for environment until now. The object of environmental monitoring in the SR has been to evaluate certain areas, e.g. components of the environment and the influences affecting it: atmosphere, water, soil, biota (fauna and flora), geological factors, physical fields, forest, wastes, settlement, landuse, contaminants of the food chain and human stress caused by environmental factors. Individual monitoring systems are being built on the basis of these projects.The Monitoring System for the Environment in the SR has been formed by linkage to the Information System on the Environment in the SR which is a basic source of the data on the state of the environment in the SR and the factors affecting it.The guarantor of both these systems is the Ministry of the Environment of the Slovak Republic.     

Inactivation of bacteria G(+)-S. aureus and G(-)-E. coli by phototoxic polythiophene incorporated in ZSM-5 zeolite

A new heterogeneous photocatalyst was prepared by oxidative polymerization of the thiophene with ferric chloride in the ZSM-5 zeolite type. The synthesized polythiophene absorbs radiation in the visible range of the electromagnetic spectrum and by illumination with visible light generates reactive oxygen species (ROS) in water medium. During illumination reactive hydroxyl radical was detected by the spin trapping EPR method. Efficiency of the photocatalyst was tested on the killing of Gram-positive bacteria Staphylococcus aureus and Gram negative bacteria Escherichia coli.     

The impact of the type and position of the halogen atom on the biodegradation of halosubstituted benzyl alcohols

The biodegradation of 2‐halosubstituted and 4‐halosubstituted benzyl alcohols was studied using two sources of biodegrative micro‐organisms: mixed culture from the ?TUDA waste water treatment plant, Dom?ale, and the white rot fungus Phanerochaete chrysosporium strain MZKI B‐223 (ATCC 24725). The results obtained by this study indicate the interrelationship between the types of micro‐organism used in the experiments and the type and position of the halogen element on the aromatic ring.     

Antimutagenic and bacteriostatic activities of Schiff‐base compounds derived from aminoguanidine,semicarbazone and thiosemicarbazone and a copper(II)‐coordination complex

The Schiff‐base aminoguanidine compounds including a resorcylidene aminoguanidine copper(II) complex that were synthesized at our laboratory posses non‐mutagenic properties when tested with Ames test using Salmonella typhimurium TA97, TA100 and TA102 bacterial strains. These compounds were tested as possible pharmacological agents in preventing a wide array of illnesses. Additionally, some of these compounds exhibit strong antimutagenic and bacteriostatic activity. Nitrovin, a known mutagen, was used in the antimutagenicity tests as the inducer. A three‐dimensional projection of the copper(II) complex was derived by the semi‐empirical method ZINDO/1 to obtain additional information about its structure, and to help elucidate a possible mechanism of action.     

Beliefs about the environment: moving from the egocentric towards the ecocentric perspective

Our behaviour towards the environment depends on our beliefs about the environment. Beliefs, however, are a subject of change, particularly during important life transitions such as the transition to adolescence, because this is a period when an individual develops the ability of complex and abstract reasoning. Understanding this transition is therefore crucial for understanding and predicting the attitudes and courses of action in terms of sustainable development later in life. Due to many methodological constraints, the number of empirical studies examining these issues is very limited; the current study aimed to collect empirical data to explore the origins of our beliefs about the environment-related issues. We devised a picture association test and used it to compare children’s and adolescents’ beliefs about our environment in the context of the means of transportation. A large sample of 2264 participants aged 6–18 years took part in the study. The data supported the claim that children’s beliefs about environment share egocentric properties. The findings represent an important puzzle into the whole picture of children’s thinking and offer us great insight into the origins of beliefs about environment-related questions in adults. Educational implications are addressed.     

Development and growth in synanthropic species: plasticity and constraints

Urbanization poses serious extinction risks, yet some species thrive in urban environments. This may be due to a pronounced developmental plasticity in these taxa, since phenotypically, plastic organisms may better adjust to unpredictable urban food resources. We studied phenotypic plasticity in Nuctenea umbratica, a common European forest and urban vegetation spider. We subjected spiderlings to low (LF), medium (MF) and high (HF) food treatments and documented their growth and developmental trajectories into adulthood. Spiders from the three treatments had comparable numbers of instars and growth ratios, but differed in developmental periods. Longest developing LF spiders (♀?=?390, ♂?=?320 days) had the smallest adults, but MF (♀?=?300, ♂?=?240 days) and HF (♀?=?240, ♂?=?210 days) spiders reached comparable adult sizes through shorter development. While males and females had comparable instar numbers, females had longer development, higher growth ratios, adult sizes and mass; and while males adjusted their moulting to food availability, female moulting depended on specific mass, not food treatment. We discussed the patterns of Nuctenea sex-specific development and compared our results with published data on two other Holarctic urban colonizers (Larinioides sclopetarius, Zygiella x-notata) exhibiting high plasticity and fast generation turn-over. We conclude that despite relatively unconstrained developmental time in the laboratory enabling Nuctenea to achieve maximal mass and size—main female fitness proxies—their relatively fixed growth ratio and long generation turn-over may explain their lower success in urban environments.     

Women infected with parasite Toxoplasma have more sons

The boy-to-girl ratio at birth (secondary sex ratio) is around 0.51 in most populations. The sex ratio varies between societies and may be influenced by many factors, such as stress and immunosuppression, age, primiparity, the sex of the preceding siblings and the socioeconomic status of the parents. As parasite infection affects many immunological and physiological parameters of the host, we analyzed the effect of latent toxoplasmosis on sex ratios in humans. Clinical records of 1,803 infants born from 1996 to 2004 contained information regarding the mother’s age, concentration of anti-Toxoplasma antibodies, previous deliveries and abortions and the sex of the newborn. The results of our retrospective cohort study suggest that the presence of one of the most common parasites (with a worldwide prevalence from 20 to 80%), Toxoplasma gondii, can influence the secondary sex ratio in humans. Depending on the antibody concentration, the probability of the birth of a boy can increase up to a value of 0.72, C.I.₉₅ = (0.636, 0.805), which means that for every 260 boys born, 100 girls are born to women with the highest concentration of anti-Toxoplasma antibodies. The toxoplasmosis associated with immunosuppression or immunomodulation might be responsible for the enhanced survival of male embryos. In light of the high prevalence of latent toxoplasmosis in most countries, the impact of toxoplasmosis on the human population might be considerable.