Health Concerns Versus Mobile Data Needs: Conjoint Measurement of Preferences for Mobile Communication Network Scenarios

As demands for mobile broadband services and ubiquitous network coverage in our societies are increasing, the mobile communication network infrastructure has to be expanded. Concurrently, the technical infrastructure of mobile communication technologies (base stations) raises the public's concerns about health risks due to electromagnetic fields (EMF). By applying conjoint analyses, the study empirically investigates the relationship between mobile data demands, different base station locations, the prevalence of perceived health complaints, and the impact of compensation payments. Findings show that health concerns are the most critical factor for mobile network communication scenario preferences, followed by data rate availability. In the decision scenarios, base station location and compensation payments played a minor role. Two user groups, cellphone and smart phone users who differ in their sensitivity regarding health concerns and data demands, were identified by segmentation analysis. By means of a sensitivity analysis, different mobile communication network scenarios were analyzed. Outcomes show the importance of integrating users’ preferences into the design of mobile communication networks. This especially refers to an increased sensitivity regarding health concerns in cellphone users and minimum requirements for data rates at least sufficient for the usage of mobile Internet services for smart phone users.     

Ureter Regeneration–The Proper Scaffold Has to Be Defined

The aim of this study was to compare two different acellular scaffolds: natural and synthetic, for urinary conduit construction and ureter segment reconstruction. Acellular aortic arch (AAM) and poly(L-lactide-co-caprolactone) (PLCL) were used in 24 rats for ureter reconstruction in both tested groups. Follow-up period was 4 weeks. Intravenous pyelography, histological and immunohistochemical analysis were performed. All animals survived surgical procedures. Patent uretero-conduit junction was observed only in one case using PLCL. In case of ureter segment reconstruction ureters were patent in one case using AAM and in four cases using PLCL scaffolds. Regeneration of urothelium layer and focal regeneration of smooth muscle layer was observed on both tested scaffolds. Obtained results indicates that synthetic acellular PLCL scaffolds showed better properties for ureter reconstruction than naturally derived acellular aortic arch.     

Disentangling natural and anthropogenic drivers of changes in a shallow lake using palaeolimnology and historical archives

Shallow lakes are susceptible to catastrophic regime shifts characterised by the presence or absence or macrophytes. However, the long-term controls on macrophyte succession in shallow lakes are incompletely understood. To investigate this, we analysed multiple sediment proxies in Lake Rotcze (Eastern Poland), a small, shallow and densely macrophyte-covered lake to (1) reconstruct the ‘reference conditions’ (sensu WFD) and development of the lake in recent centuries, (2) compare historical evidence with the sedimentary record, and (3) identify the natural and anthropogenic drivers of macrophyte succession. Before the twentieth century, conditions in the lake may be referred to as ‘reference conditions’. Subsequently forest clearance in the catchment resulted in lower water transparency, but concurrent catchment drainage lowered water levels and increased macrophyte development. Since 1950 elevated nutrient supply and climatically driven increases in water levels led to the deterioration of water transparency and partial macrophyte withdrawal. At the end of the twentieth century lake-level drawdown led to low phytoplankton biomass and clear water creating a novel ecosystem where macrophytes invade the whole lake. These patterns suggest that both natural and anthropogenically induced water level fluctuations have been critical drivers of macrophyte development.     

Thermally-induced structural and chemical alteration of organic-walled microfossils: an experimental approach to understanding fossil preservation in metasediments

The identification and confirmation of bona fide Archean–Paleoproterozoic microfossils can prove to be a challenging task, further compounded by diagenetic and metamorphic histories. While structures of likely biological origin are not uncommon in Precambrian rocks, the search for early fossil life has been disproportionately focused on lesser thermally altered rocks, typically greenschist or lower‐grade metamorphism. Recently, however, an increasing number of inferred micro‐ and macrofossils have been reported from higher‐grade metasediments, prompting us to experimentally test and quantify the preservability of organic‐walled microfossils over varying durations of controlled heating and under two differing redox conditions. Because of their relatively low‐intensity natural thermal alteration, acritarchs from the Mesoproterozoic Ruyang Group were chosen as subjects for experimental heating at approximately 500°C, with durations ranging from 1 to 250 days and in both oxic (normal present day conditions) and anoxic conditions. Upon extraction, the opacity, reflectivity, color, microchemistry, and microstructures of the heated acritarchs were characterized using optic microscopy, scanning electron microscopy, Raman spectroscopy, and X‐ray photoelectron spectroscopy. The results differ for acritarchs prepared under oxic vs. anoxic conditions, with the anoxic replicates surviving experimental heating longer and retaining biological morphologies better, despite an increasing degree of carbonization with continuous heating. Conversely, the oxic replicates show aggressive degradation. In conjunction with fossils from high‐grade metasediments, our data illustrate the preservational potential of organic‐walled microfossils subjected to metamorphism in reducing conditions, offer insights into the search for microfossils in metasediments, and help to elucidate the influence of time on the carbonization/graphitization processes during thermal alteration.     

Drilling predation on serpulid polychaetes (Ditrupa arietina) from the pliocene of the Cope Basin, Murcia Region, Southeastern Spain

We report quantitative analyses of drilling predation on the free-living, tube-dwelling serpulid polychaete Ditrupa arietina from the Cope Cabo marine succession (Pliocene, Spain). Tubes of D. arietina are abundant in the sampled units: 9 bulk samples from 5 horizons yielded ~5925 specimens of D. arietina. Except for fragmentation, tubes were well preserved. Complete specimens ranged from 3.1 to 13.4 mm in length and displayed allometric growth patterns, with larger specimens being relatively slimmer. Drilled Ditrupa tubes were observed in all samples. Drillholes, identified as Oichnus paraboloides, were characterized by circular to elliptical outline (drillhole eccentricity increased with its diameter), parabolic vertical profile, outer diameter larger than inner diameter, penetration of one tube wall only, narrow range of drill-hole sizes, and non-random (anterior) distribution of drillholes. A total of 233 drilled specimens were identified, with drilling frequencies varying across horizons from 2.7% to 21% (3.9% for pooled data). Many tube fragments were broken across a drillhole suggesting that the reported frequencies are conservative and that biologically-facilitated (drill-hole induced) fragmentation hampers fossil preservation of complete serpulid tubes. No failed or repaired holes were observed. Multiple complete drillholes were present (3.9%). Drilled specimens were significantly smaller than undrilled specimens and tube length and drill-hole diameter were weakly correlated. The results suggest that drillholes were produced by a size-selective, site-stereotypic predatory organism of unknown affinity. The qualitative and quantitative patterns reported here are mostly consistent with previous reports on recent and fossil Ditrupa and reveal parallels with drilling patterns documented for scaphopod mollusks, a group that is ecologically and morphologically similar to Ditrupa. Consistent with previous studies, the results suggest that free-dwelling serpulid polychaetes are preyed upon by drilling predators and may provide a viable source of data on biotic interactions in the fossil record.     

Electrospinning of bovine serum albumin. Optimization and the use for production of biosensors

Electrospinning of the globular protein, bovine serum albumin (BSA), was optimized to obtain proteinous fibers suitable as biosensors. It was shown that the as-spun protein preserves its native form, whereas solubility of the cross-linked in the ambient conditions BSA nanofibers evidently decreases. Insoluble BSA fibers can be easily modified to be used as two-dimensional biosensors. Here, we show the micro pH sensor obtained from the BSA fiber stained with a fluorescein derivative (FITC).     

Satellite DNA repeat sequence variation is low in three species of burying beetles in the genus Nicrophorus (Coleoptera: Silphidae)

Three satellite DNA families were identified in three species of burying beetles, Nicrophorus orbicollis, N. marginatus, and N. americanus. Southern hybridization and nucleotide sequence analysis of individual randomly cloned repeats shows that these satellite DNA families are highly abundant in the genome, are composed of unique repeats, and are species-specific. The repeats do not have identifiable core elements or substructures that are similar in all three families, and most interspecific sequence similarity is confined to homopolymeric runs of A and T. Satellite DNA from N. marginatus and N. americanus show single-base-pair indels among repeats, but single-nucleotide substitutions characterize most of the repeat variability. Although the repeat units are of similar lengths (342, 350, and 354 bp) and A + T composition (65%, 71%, and 71%, respectively), the average nucleotide divergence among sequenced repeats is very low (0.18%, 1.22%, and 0.71%, respectively). Transition/transversion ratios from the consensus sequence are 0.20, 0.69, and 0.70, respectively.      

Interaction of DNA-dependent protein kinase with DNA and with Ku: biochemical and atomic-force microscopy studies.

DNA-dependent protein kinase (DNA-PK or the scid factor) and Ku are critical for DNA end-joining in V(D)J recombination and in general non-homologous double-strand break repair. One model for the function of DNA-PK is that it forms a complex with Ku70/86, and this complex then binds to DNA ends, with Ku serving as the DNA-binding subunit. We find that DNA-PK can itself bind to linear DNA fragments ranging in size from 18 to 841 bp double-stranded (ds) DNA, as indicated by: (i) mobility shifts; (ii) crosslinking between the DNA and DNA-PK; and (iii) atomic-force microscopy. Binding of the 18 bp ds DNA to DNA-PK activates it for phosphorylation of protein targets, and this level of activation is not increased by addition of purified Ku70/86. Ku can stimulate DNA-PK activity beyond this level only when the DNA fragments are long enough for the independent binding to the DNA of both DNA-PK and Ku. Atomic-force microscopy indicates that under such conditions, the DNA-PK binds at the DNA termini, and Ku70/86 assumes a position along the ds DNA that is adjacent to the DNA-PK.