Structural and chemical requirements for histidine phosphorylation by the chemotaxis kinase CheA

The CheA histidine kinase initiates the signal transduction pathway of bacterial chemotaxis by autophosphorylating a conserved histidine on its phosphotransferase domain (P1). Site-directed mutations of neighboring conserved P1 residues (Glu-67, Lys-48, and His-64) show that a hydrogen-bonding network controls the reactivity of the phospho-accepting His (His-45) in Thermotoga maritima CheA. In particular, the conservative mutation E67Q dramatically reduces phospho-transfer to P1 without significantly affecting the affinity of P1 for the CheA ATP-binding domain. High resolution crystallographic studies revealed that although all mutants disrupt the hydrogen-bonding network to varying degrees, none affect the conformation of His-45. N-15-NMR chemical shift studies instead showed that Glu-67 functions to stabilize the unfavored (NH)-H-delta 1 tautomer of His-45, thereby rendering the N-epsilon 2 imidazole unprotonated and well positioned for accepting the ATP phosphoryl group

Assessment of Automated Analyses of Cell Migration on Flat and Nanostructured Surfaces

Motility studies of cells often rely on computer software that analyzes time-lapse recorded movies and establishes cell trajectories fully automatically. This raises the question of reproducibility of results, since different programs could yield significantly different results of such automated analysis. The fact that the segmentation routines of such programs are often challenged by nanostructured surfaces makes the question more pertinent. Here we illustrate how it is possible to track cells on bright field microscopy images with image analysis routines implemented in an open-source cell tracking program, PACT (Program for Automated Cell Tracking). We compare the automated motility analysis of three cell tracking programs, PACT, Autozell, and TLA, using the same movies as input for all three programs. We find that different programs track overlapping, but different subsets of cells due to different segmentation methods. Unfortunately, population averages based on such different cell populations, differ significantly in some cases. Thus, results obtained with one software package are not necessarily reproducible by other software

The Development and Study of Some Composite Membranes Based on Polyurethanes and Iron Oxide Nanoparticles

To improve the performance of composite membranes, their morphology can be tailored by precise control of the fabrication methods and processing conditions. To this end, the aim of this study was to develop novel high-performance composite membranes based on polyurethane matrix and magnetic nanoparticles with the desired morphology and stability, by selecting the proper method and fabrication systems. These well-prepared composite membranes were investigated from the point of view of their morphological, physico-chemical, mechanical, dielectric, and magnetic properties. In addition, their in vitro cytocompatibility was also verified by the MTT assay and their cell morphology. The results of this study can provide valuable information regarding the preparation of magnetic polyurethane-based composite membranes that could be used to design some suitable devices with tailored properties, in order to improve the image quality in magnetic resonance imaging investigations and to suppress local image artifacts and blurring

Essentials of surgical anatomy and technique in TAPP repair of inguinal hernia

Laparoscopic hernia repair has opened a new era in hernia surgery shifting paradigms from anterior to posterior approaches. This has exposed surgeons to new anatomical perspectives, technical challenges and clinical implications all of which preventing the technique from becoming ubiquitous despite numerous advantages, limited contraindications and low recurrence rates. In order to address the difficult learning curve of the laparoscopic transabdominal preperitoneal hernia repair this paper presents the experience and points of view from a tertiary surgical department on the systematization of anatomical concepts pertinent to the TAPP repair technique, a decalogue of suggestions related to the surgical technique and a short reminder of the most common complications and how to avoid them. Revising the anatomy essentials and proposing a decalogue of the surgical technique and a memento on the most common complications will provide young surgeons with a scaffold of basic knowledge on TAPP hernia repair

Conflicting interests between local governments and the European target of no net land take

To halt land take in Europe, the European Union set a “no net land take by 2050″ target in 2011. However, land take continues to occur in European countries, with recent studies suggesting that local decision-making is playing a major role in these land-use conversions. In this study, we investigated how urban growth boundaries (UGBs) are used by local governments to manage urban growth in Romania. A mixed-method approach was adopted, combining analysis of UGB changes over the past decade in all Romanian cities (N = 319) with a survey among representatives of local governments involved in land-use decision-making (N = 91 cities). The results showed that many cities have expanded their UGBs, despite population loss and sufficient undeveloped land within UGBs, showing that local government decisions conflict with policy targets at the European level. This is even the case when there is no physical need for land-take limits to be exceeded. We show that population dynamics and the extent of nature conservation areas significantly contribute to UGB changes, though these explain just a small fraction of all UGB changes. Furthermore, we identified a wide range of motivations among decision-makers regarding changing UGBs, including not only the fiscal system but also cities’ competitiveness and decisions about the long-term vision for development. We argue that policy innovations in urban containment should (i) aim to balance the interests of governments at different administrative levels, (ii) account for the particularities of each state member's planning system, and (iii) allow for integrated and strategic city planning

Emergency-line calls as an indicator to assess human–wildlife interaction in urban areas

Human–wildlife interactions (HWIs) are increasingly common human disturbances as development continues to remove wildlife habitats. Documenting HWI is critical for environmental protection agencies to develop strategies and management decisions that meet the needs of both people and wildlife. However, evaluation of the frequency and types of HWI at broad spatial scales (e.g., national or regional level) can be costly and difficult to implement by managers. In this study, we apply a novel method for the evaluation of patterns of HWI in urban areas by using publicly available data from emergency calls (ECs) placed by inhabitants of Romania\u27s urban areas. We used information from 4601 ECs placed at the Romanian National Emergency Call System 112, which consisted of (1) wildlife species, (2) spatial location, (3) date and time, and (4) a short description of the emergency. Of the 318 analyzed cities, 300 cities documented ECs on HWI between 2015 and 2020, with roe deer and brown bear being the most frequently mentioned species. We recorded an increasing trend in HWI-related ECs in 73% of the urban areas over the five-year period. We mapped the large-scale distribution of HWI by species and type of interactions in order to capture variations at the national level. Further, we analyzed the social and the biophysical factors potentially influencing the occurrence and frequency of HWI. The results showed that social factors have the same effect on all species, while the effect of the biophysical factors varied between species. Particularly, the presence of large natural habitats, represented by forests, influenced the number of calls only for brown bears. Seminatural landscapes with agricultural land have a different influence in terms of effect and significance for the considered species. Our results suggest that publicly available data from ECs can be used for the rapid assessment of HWI and for evaluating trends and predictors of HWI at broad spatial scales

Can Church Gardens Represent a Valuable Recreation Alternative in Cities?

Urban green infrastructure is a key element in improving quality of life and creating an appropriate framework for sustainable, resilient and inclusive cities. Also, achieving a coherent spatial planning based on development of urban green infrastructure can be an useful solution to negative changes related to environmental quality, segregation and ecosystem services. We use church gardens in Bucharest as a case study to understand how these small green spaces can be integrated into urban planning. The paper aims to analyse the potential of church gardens as recreation areas at city level in Romania. The analysis focused on three major aspects – the spatial distribution of churches, the accessibility of green spaces located in church gardens (calculated both for adults and elderly people as most important groups accessing the gardens) and the characteristics of those gardens in terms of facilities, use and problems (based on a field survey filled for a 20% sample of the 287 churches in Bucharest). The results showed that the homogenous spatial distribution of churches with green gardens makes them accessible for residential areas located far from traditional green recreational areas. In Bucharest, the service areas of churches with green spaces cover 84% of the residential areas when accounting for the adult’s walking speed and 61% when accounting for elderly people. Green spaces in church gardens amount to over 25 ha in Bucharest, with an average of 1737 square meters per garden, representing a surface which could be designed to respond better to the population needs. The major challenges identified in the church gardens are (a) the use of green space for other purposes than recreations, such as storage space for construction materials (31.5%), waste (17.5%), temporal constructions (12.3%) or car parking (21%), and (b) quality of vegetation. Our study highlights that through their number and distribution church gardens can represent an alternative to large green areas if they are opened to the population and used for organising activities and events. Their importance and potential could be increased if designed for such purpose. Such analysis can be useful in the planning process of small urban green areas in order to integrate them into urban management process

Composite Materials Based on Gelatin and Iron Oxide Nanoparticles for MRI Accuracy

The majority of recent studies have focused on obtaining MRI materials for internal use. However, this study focuses on a straightforward method for preparing gelatin-based materials with iron oxide nanoparticles (G–Fe2O3 and G–Fe3O4) for external use. The newly obtained materials must be precisely tuned to match the requirements and usage situation because they will be in close touch with human/animal skin. The biocompatible structures formed by gelatin, tannic acid, and iron oxide nanoparticles were investigated by using FTIR spectroscopy, SEM-EDAX analysis, and contact angle methods. The physico-chemical properties were obtained by using mechanical investigations, dynamic vapor sorption analysis, and bulk magnetic determination. The size and shape of iron oxide nanoparticles dictates the magnetic behavior of the gelatin-based samples. The magnetization curves revealed a typical S-shaped superparamagnetic behavior which is evidence of improved MRI image accuracy. In addition, the MTT assay was used to demonstrate the non-toxicity of the samples, and the antibacterial test confirmed satisfactory findings for all G-based materials