Assessment of the patulin contamination level in selected apple-based products available in retail in Poland

The aim of this study was to assess the level of patulin (PAT) contamination in selected apple-based products, including food intended for infants and young children, available in retail in Poland in 2016–2020. The products examined were selected due to their availability on the market and all of them derived from conventional production. All products examined contained only apples in their composition, with no other fruit added. The obtained results were related to the provisional maximum tolerable daily intake (PMTDI) of PAT established by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (JECFA) (WHO 1995). In addition, in selected age groups, exposure assessment resulting from the intake of this toxin in the diet, was estimated. Only 2 of the 47 examined apple products contained PAT. The determined levels of contamination were significantly lower than a maximum acceptable level specified in the provisions of the food law at the level of 50.0 μg kg-1 for apple juice. When considering the value of the average daily consumption of apple juice in Poland, the PAT daily intake from apple juice did not exceed the tolerable daily intake in any of the examined samples and amounted to a maximum of 1.6% of PMTDI. As for one portion recommended for consumption, the result obtained was also below tolerable daily intake and constituted a maximum of 38.7% of PMTDI. These findings are a particularly valuable source of information for farmers, traders and consumers, and confirm health safety of apple juice and apple-based products intended for infants and young children

Introduction

Childhood is an extremely unique period in the life of every human being. During the childhood, small children are not prepared to function in the world at all, yet this period will affect their entire future life. Testament to the complexity of this period are the definitional considerations which need to be accounted for in the pedagogical construction of childhood, which in the Encyclopedia of Childhood runs to seven categories – the psychological, biological, sociological, historical, anthropological-cultural, political, and, finally, the legal.The definition of childhood has been constantly evolving for centuries but now there are new proposals which are more compatible with the development of science “Childhood is a sociological construct, created by children and for children – it is a biological fact which also has a social dimension (…). Children, as members of a society, may construct their own identity and influence the identity of others through their participation in educational dialogue. In this framework, the relationship between children and adults is based on reciprocity, love and the sharing of power and control.Childhood, as with every other period of development, is and should be researched. But childhood research is special, inter alia in view of the dual legal status of the research subjects – children. This requires knowledge from the researcher of both legal regulations as well as the ethical difficulties which may be related to them. The contemporary methodology of social science is extremely rich in the available ways to conduct research, both in quantitative and qualitative ways.Childhood research may be conducted based on various paradigms and methods. If the researcher decides to embark on research with children (the participatory paradigm), it will not only be a methodological challenge, but it will also pose ethical and pedagogical questions. We hope that this edition of the journal will serve to outline the horizons of those research experiences.

Wstęp

Dzieciństwo to niezwykle specyficzny okres w życiu każdego człowieka. To właś­nie w ten czas, w którym mały człowiek w zasadzie w ogóle nie jest przygotowany do samodzielnego funkcjonowania w świecie, zaważy na całym jego przyszłym życiu. O złożoności tego okresu mogą świadczyć rozważania definicyjne, które w Encyklopedii dzieciństwa koncentrują się wokół kilku kategorii: pedagogicznej, psychologicznej biologicznej, socjologicznej, historycznej, antropologiczno-kulturowej, politycznej, i w końcu prawnej.Definicje dzieciństwa w ciągu wieków podlegały zmianom, pojawiały się coraz to nowe propozycje, zgodne z rozwojem nauki. Według jednej z nowszych teorii: „Dzieciństwo jest konstruktem społecznym, tworzonym przez dzieci i dla dzieci – jest więc faktem biologicznym posiadającym też wymiar społeczny (...). Dzieci jako członkowie społeczeństwa mogą konstruować własną tożsamość i posiadać wpływ na tożsamość innych poprzez uczestniczenie w wychowawczym dialogu. W tym ujęciu relacja między dziećmi a dorosłymi opiera się na wzajemności, miłości oraz dzieleniu się władzą i kontrolą”[3].Dzieciństwo, tak jak każdy inny okres życia, jest i powinno być badane. Prace nad dzieciństwem są jednak szczególne, a to ze względu na podwójny status prawny podmiotu badań – dziecka[4]. Sytuacja taka wymaga od badacza znajomości zarówno regulacji prawnych[5], jak i zmierzenia się z trudnościami natury etycznej, jakie mogą się z tym wiązać. Współczesna metodologia badań społecznych jest niezwykle bogata w kwestii sposobów prowadzenia badań, zarówno w strategii ilościowej, jak i jakościowej.Badania nad dzieciństwem mogą być prowadzone w oparciu o różne paradygmaty i metody. Jeśli badacz zdecyduje się na eksplorację z dziećmi (paradygmat partycypacyjny), wówczas będzie to wyzwanie nie tylko metodologiczne, ale też etyczne i pedagogiczne. Mamy nadzieję, że niniejszy numer czasopisma zakreśla szerokie horyzonty takich doświadczeń badawczych.  

Identification of new business models in micro and small enterprises in the energy sector

The initial identification of new business models in micro- and medium-sized energy enterprises is the aim of this paper. Based on the literature review, different definitions of business models were presented and a range of research conducted by other authors focusing on the business models in the energy sector was shortly described. The state of the art allows to identify a research gap suggesting that this type of companies has not yet been studied. Presented results of the research were addressed to micro- and medium-sized energy enterprises producing or delivering services connected with e.g. energy efficiency. The research was conducted with the use of a direct questionnaire on 30 respondents in November 2019. It was identified that the business models of these enterprises are classical. Two types of models were distinguished i.e. for companies whose key customers are households (B2C model) and business (B2B model)

Energy Prosumers : Profiling the Energy Microgeneration Market In Lower Silesia, Poland

Microgeneration of energy has the potential to become an important component of the energy policy of many governments, because it may substantially lower carbon emissions and reduce the need for new infrastructure. Nevertheless, from recent studies it follows that, even in the developed countries, microgeneration technology is far from being widely adopted. In this study, we use data collected in a survey conducted in Lower Silesia, a south-western region of Poland, to build behavioural profiles of energy consumers, in order to get some insights into barriers to microgeneration becoming extensively adopted. In particular, we exploit the decision tree method to determine typical attributes of potential prosumers, to find the relative importance of these attributes and, finally, to make some predictions based on data that were not used in constructing the model. From our findings, it follows that economical criteria are the most important triggers for considering the installation of microgeneration technologies. Thus any governmental initiative promoting pro-ecological behaviours, including the use of renewable energy sources, should be based primarily on financial incentives to succeed. (original abstract

The ImageStream System: a key step to a new era in imaging.

The aim of this article is to provide a brief review about the ImageStream system a novel tool for multiparameter cell analysis in flow. The instrument integrates the features of flow cytometry and fluorescence microscopy combined with a modern methodology for image analysis. Similar to flow cytometry, ImageStream allows analysis of a large number of cells based on their fluorescence features and provides statistical analysis of these features. Additionally, ImageStream allows detailed morphometric cellular analysis based on acquired cellular images integrating various morphometric and photometric features of the examined cells. Simply stated, ImageStream system is an advanced flow cytometer acquiring both integrated fluorescence signals as well as high quality fluorescence images and allowing muliparameter analysis. The innovative features of the instrument offer new analytical capabilities and allow for a multitude of possible applications beyond the current means of flow cytometry. While this article summarizes basic information about the features of ImageStream and its applications based on the available literature and it also describes our own experience

Impact of graphene-based surfaces on the basic biological properties of human umbilical cord mesenchymal stem cells : implications for ex vivo cell expansion aimed at tissue repair

The potential therapeutic applications of mesenchymal stem/stromal cells (MSCs) and biomaterials have attracted a great amount of interest in the field of biomedical engineering. MSCs are multipotent adult stem cells characterized as cells with specific features, e.g., high differentiation potential, low immunogenicity, immunomodulatory properties, and efficient in vitro expansion ability. Human umbilical cord Wharton’s jelly-derived MSCs (hUC-MSCs) are a new, important cell type that may be used for therapeutic purposes, i.e., for autologous and allogeneic transplantations. To improve the therapeutic efficiency of hUC-MSCs, novel biomaterials have been considered for use as scaffolds dedicated to the propagation and differentiation of these cells. Nowadays, some of the most promising materials for tissue engineering include graphene and its derivatives such as graphene oxide (GO) and reduced graphene oxide (rGO). Due to their physicochemical properties, they can be easily modified with biomolecules, which enable their interaction with different types of cells, including MSCs. In this study, we demonstrate the impact of graphene-based substrates (GO, rGO) on the biological properties of hUC-MSCs. The size of the GO flakes and the reduction level of GO have been considered as important factors determining the most favorable surface for hUC-MSCs growth. The obtained results revealed that GO and rGO are suitable scaffolds for hUC-MSCs. hUC-MSCs cultured on: (i) a thin layer of GO and (ii) an rGO surface with a low reduction level demonstrated a viability and proliferation rate comparable to those estimated under standard culture conditions. Interestingly, cell culture on a highly reduced GO substrate resulted in a decreased hUC-MSCs proliferation rate and induced cell apoptosis. Moreover, our analysis demonstrated that hUC-MSCs cultured on all the tested GO and rGO scaffolds showed no alterations of their typical mesenchymal phenotype, regardless of the reduction level and size of the GO flakes. Thus, GO scaffolds and rGO scaffolds with a low reduction level exhibit potential applicability as novel, safe, and biocompatible materials for utilization in regenerative medicine

Gradient chitosan hydrogels modified with graphene derivatives and hydroxyapatite : physiochemical properties and initial cytocompatibility evaluation

In this study, we investigated preparation of gradient chitosan-matrix hydrogels through a novel freezing–gelling–thawing method. The influence of three types of graphene family materials (GFM), i.e., graphene oxide (GO), reduced graphene oxide (rGO), and poly(ethylene glycol) grafted graphene oxide (GO-PEG), as well as hydroxyapatite (HAp) on the physicochemical and biological properties of the composite hydrogels was examined in view of their potential applicability as tissue engineering scaffolds. The substrates and the hydrogel samples were thoroughly characterized by X-ray photoelectron spectroscopy, X-ray diffractometry, infrared spectroscopy, digital and scanning electron microscopy, rheological and mechanical analysis, in vitro chemical stability and bioactivity assays, as well as initial cytocompatibility evaluation with human umbilical cord Wharton’s jelly mesenchymal stem cells (hUC-MSCs). We followed the green-chemistry approach and avoided toxic cross-linking agents, using instead specific interactions of our polymer matrix with tannic acid, non-toxic physical cross-linker, and graphene derivatives. It was shown that the most promising are the gradient hydrogels modified with GO-PEG and HAp