Plant species diversity of pastures in the Naryn Oblast (Kyrgyzstan)

Traditional pastoral practices in Kyrgyzstan have been transformed into more intensive forms of pastoral land use during the Soviet colonial period, and once again modified after independence in 1991. Kyrgyz winter pastures close to settlements are subject to degradation processes, while remote summer pastures are less affected. It is largely unknown to what extent current grazing regimes, repeatedly modified during the post-Soviet transformation process, have influenced plant species diversity of mountain pastures. This paper aims to analyze inventory (α) and differentiation (β) diversity of pastures in the Naryn Oblast, where winter pastures are subject to increased grazing pressure. We used a non-asymptotic approach in order to infer Hill numbers, i.e. the effective number of species at different levels of q (where q = 0: species richness, q = 1: Shannon diversity, q = 2: Simpson diversity) to make fair comparisons among assemblages of winter and summer pastures. We established sample-size-based rarefaction (interpolation) and prediction (extrapolation) curves, and assessed beta diversity by implementing an ANOSIM and by calculating Jaccard and Sørensen indices. We also inspected the occurrence of rare endemic plants, which might play a key role in local ecosystem processes and are important for biodiversity conservation. Increased grazing pressure on winter pastures mainly results from abandoned seasonal livestock migration and unbalanced grazing intensity between seasonal pastures. Our results show that inventory diversity is higher on summer pastures and that species composition between summer and winter pastures differs significantly. Winter pastures are less species-rich but have a higher percentage of rare endemic species

In a no-win situation: The employment–health dilemma

Work and organizational psychology (WOP) research has to date mostly focused on people privileged to have the choice between several attractive job options and less on people who are restricted in their job choice (e.g., due to their qualification or personal contingencies) and have to choose from fewer and often less-than-optimal jobs. Often, the jobs available to the latter are characterized by precarious employment and hazardous working conditions which can put them in the difficult situation of having to choose between a health-threatening job and possible unemployment. Building on interdisciplinary literature, we propose the employment–health dilemma (E-H dilemma) as a framework for analyzing this intrapersonal conflict of having to choose between employment (incurring health threats) and health (incurring economic threats) and discuss potential antecedents and consequences of the E-H dilemma at the societal, organizational, and individual level. We outline the implications of the E-H dilemma and make a case for examining the full spectrum of job choice situations in WOP research. In doing so, we demonstrate what WOP can gain by embracing a more inclusive and multidisciplinary approach: uncovering processes in their entirety (e.g., job choice decisions of all people) and strengthening the role and legitimacy of WOP in society

Ethnic Differences in Context: Does Emotional Conflict Mediate the Effects of Both Team- and Individual-Level Ethnic Diversity on Emotional Strain?

Work teams are becoming increasingly heterogeneous with respect to their team members’ ethnic backgrounds. Two lines of research examine ethnic diversity in work teams: The compositional approach views team-level ethnic heterogeneity as a team characteristic, and relational demography views individual-level ethnic dissimilarity as an individual member’s relation to their team. This study compares and contrasts team-level ethnic heterogeneity and individual-level ethnic dissimilarity regarding their effects on impaired well-being (i.e., emotional strain) via team- and individual-level emotional conflict. Fifty teams of retail chain salespeople (n = 602) participated in our survey at two points of measurement. Based on the ethnic background of team members, we calculated team-level ethnic heterogeneity that applied to all members, and individual-level ethnic dissimilarity within the team that varied according to each member’s ethnic background. Multilevel path modeling showed that high levels of team-level ethnic heterogeneity were related to high levels of emotional strain via team-level emotional conflict. However, the opposite was found for individual-level ethnic dissimilarity. We discussed this difference by contextualizing individual-level ethnic dissimilarity in the team-level heterogeneity and social status of ethnic groups in society at large. Our findings suggest that the social status of the ethnic group to which team members belong may impact how ethnic diversity relates to team processes and well-being.Humboldt-Universität zu Berlin (1034)Peer Reviewe

Static and dynamic 3D culture of neural precursor cells on macroporous cryogel microcarriers

Neural precursor cells have been much studied to further our understanding of the far-reaching and controversial question of adult neurogenesis. Currently, differentiation of primary neural precursor cells from the mouse dentate gyrus via 2-dimentional in vitro culture yields low numbers of neurons, a major hindrance to the field of study. 3-dimentional “neurosphere” culture allows better 3D cell-cell contact, but control over cell differentiation is poor because nutrition and oxygen restrictions at the core of the sphere causes spontaneous differentiation, predominantly to glial cells, not neurons. Our group has developed macroporous scaffolds, which overcome the above-mentioned problems, allowing long-term culture of neural stem cells, which can be differentiated into a much higher yield of neurons. Herein we describe a method for culturing neural precursor cells on RGD peptide functionalized-heparin containing cryogel scaffolds, either in standard non-adherent well-plates (static culture) or in spinner flasks (dynamic culture). This method includes: • The synthesis and characterization of heparin based microcarriers. • A “static” 3D culture method for that does not require spinner flask equipment. • “Dynamic” culture in which cell loaded microcarriers are transferred to a spinner flask. © 2020 The Author

Reversible cation exchange on macroscopic CdSe/CdS and CdS nanorod based gel networks

Over the past decades, cation exchange reactions applied to nanoparticles have opened up synthetic pathways to nanocrystals, which were not accessible by other means before. The limitation of cation exchange on the macroscopic scale of bulk materials is given by the limited ion diffusion within the crystal structure. Lyogels or aerogels are macroscopic, highly voluminous, porous materials composed of interconnected nanoscopic building blocks and hence represent a type of bridge between the macroscopic and the nanoscopic world. To demonstrate the feasibility of cation exchange on such macroscopic nanomaterials, the cation exchange on CdSe/CdS core/shell and CdS nanorod based lyogels to Cu2−xSe/ Cu2−xS and Cu2−xS and the reversible exchange back to CdSe/CdS and CdS lyogels is presented. These copper-based lyogels can also be used as an intermediate state on the way to other metal chalcogenidebased macroscopic structures. By reversed cation exchange back to cadmium an additional proof is given, that the crystal structures remain unchanged. It is shown that cation exchange reactions can also be transferred to macroscopic objects like aerogels or lyogels. This procedure additionally allows the access of aerogels which cannot be synthesized via direct destabilization of the respective colloidal solutions

Static and dynamic 3D culture of neural precursor cells on macroporous cryogel microcarriers

Neural precursor cells have been much studied to further our understanding of the far-reaching and controversial question of adult neurogenesis. Currently, differentiation of primary neural precursor cells from the mouse dentate gyrus via 2-dimentional in vitro culture yields low numbers of neurons, a major hindrance to the field of study. 3-dimentional “neurosphere” culture allows better 3D cell-cell contact, but control over cell differentiation is poor because nutrition and oxygen restrictions at the core of the sphere causes spontaneous differentiation, predominantly to glial cells, not neurons. Our group has developed macroporous scaffolds, which overcome the above-mentioned problems, allowing long-term culture of neural stem cells, which can be differentiated into a much higher yield of neurons. Herein we describe a method for culturing neural precursor cells on RGD peptide functionalized-heparin containing cryogel scaffolds, either in standard non-adherent well-plates (static culture) or in spinner flasks (dynamic culture). This method includes: • The synthesis and characterization of heparin based microcarriers. • A “static” 3D culture method for that does not require spinner flask equipment. • “Dynamic” culture in which cell loaded microcarriers are transferred to a spinner flask

Macroporous heparin-based microcarriers allow long-term 3D culture and differentiation of neural precursor cells

Adult neurogenesis and the neurogenic niche in the dentate gyrus are subjects of much research interest. Enhancing our knowledge of this niche process and the role played by this unique microenvironment would further our understanding of plasticity and its relevance for cognition in health and disease. The complex three-dimensional (3D) nature of the niche microenvironment is poorly recapitulated in current cell culture experimental procedures. Neural precursor cells (NPCs) are cultured either on two-dimensional (2D) surfaces, where cells quickly reach confluency and passaging is required, or as 3D neurospheres, with the limitation of poor diffusion of nutrients and thus partial differentiation of cells over time. Herein, we culture NPCs on microscale scaffolds termed microcarriers, composed of poly(ethylene glycol) and heparin, designed to more closely represent the 3D environment of the neurogenic niche. The interconnected macroporous structure of the microcarriers allows NPCs to attach to their pore walls with subsequent continuous proliferation (analyzed up to 28 days) without formation of a necrotic core. Removal of basic fibroblast growth factor and epidermal growth factor from the culture medium results in differentiation of the NPCs. Unlike 2D culture, a high percentage of neurons was achieved on the microcarriers (22% MAP2 positive cells) indicating that these 3D microscale scaffolds give a more conducive environment for neuronal differentiation. Microcarrier culture of NPCs allows long-term cell expansion and better differentiation, which provides superior culture conditions for studying/modelling the neurogenic niche

Ba3Ga3N5 - A Novel Host Lattice for Eu2+ - Doped Luminescent Materials with Unexpected Nitridogallate Substructure

The alkaline earth nitridogallate Ba3Ga3N5 was synthesized from the elements in a sodium flux at 760°C utilizing weld shut tantalum ampules. The crystal structure was solved and refined on the basis of single-crystal X-ray diffraction data. Ba3Ga3N5 (space group C2/c (No. 15), a = 16.801(3), b = 8.3301(2), c = 11.623(2) Å, β = 109.92 (3)°, Z = 8) contains a hitherto unknown structural motif in nitridogallates, namely, infinite strands made up of GaN4 tetrahedra, each sharing two edges and at least one corner with neighboring GaN4 units. There are three Ba2+ sites with coordination numbers six or eight, respectively, and one Ba2+ position exhibiting a low coordination number 4 corresponding to a distorted tetrahedron. Eu2+ - doped samples show red luminescence when excited by UV irradiation at room temperature. Luminescence investigations revealed a maximum emission intensity at 638 nm (FWHM =2123 cm−1). Ba3Ga3N5 is the first nitridogallate for which parity allowed broadband emission due to Eu2+ - doping has been found. The electronic structure of both Ba3Ga3N5 as well as isoelectronic but not isostructural Sr3Ga3N5 was investigated by DFT methods. The calculations revealed a band gap of 1.53 eV for Sr3Ga3N5 and 1.46 eV for Ba3Ga3N5