Comparative evaluation of two simple diffuse reflectance models for biological tissue applications

We present a comparative evaluation of two simple diffuse reflectance models for biological tissue applications. One model is based on a widely accepted and used in biomedical optics implementation of diffusion theory, and the other one is based on a semiempirical approach derived from basic physical principles. We test the models on tissue phantoms and on human skin, utilizing a standard six-around-one optical fiber probe for light delivery and collection. We show that both models are suitable for use with an optical fiber probe and illustrate the potential, applicability, and validity range of the models.     

Assessment of donkey milk chemical,microbiological and sensory attributes in Greece and Cyprus

This study aimed to assess the nutritional, hygienic and sensory characteristics of donkey milk produced in Greece and Cyprus. The average values for pH, fat, protein and lactose were 7.14, 0.52 g/100 mL, 1.22 g/100 mL and 7.01 g/100 mL, respectively, whereas aflatoxin M1 and beta‐lactam residues were not detected in any sample. The microbiological analysis revealed very low somatic cell counts and total microbial counts, while Escherichia coli, Salmonella spp and Listeria monocytogenes were not detected in any sample. The sensory evaluation classified the milk as white, thin, with a slightly sweet pleasant taste, pleasant milky aroma, sweet flavour and no persistent aftertaste.     

Wood availability and habitat heterogeneity drive spatiotemporal habitat use by riverine cyprinids under flow intermittence

Interspecies and intraspecies variation in the use of wooded habitats has been studied for salmonids, but little is known about nonsalmonid species. In this study, we explored spatiotemporal differences in the distribution of three cyprinid species at habitats of varying wood density and at habitats of varying heterogeneity in a Mediterranean intermittent river (Evrotas, southern Greece). Hydroecological data from 843 microhabitats across four sites and in five sampling periods were collected and analysed using generalized linear mixed effects models. Adult chubs, minnowroaches, and minnows and, to a lesser degree, juvenile chubs, preferred complex, wooded habitats, characterized by lower flow velocities, higher water depths, finer substrate, and increased canopy cover, compared with wood‐free and noncomplex habitats. At the advanced stage of the dry period, the deeper, wooded habitats served as drought refugia; all fish groups, except for the adult chub, resorted to these habitats during autumn. In contrast, no such shifts were evident in early summer at the onset of the dry period. In late spring, all fish groups had higher densities at wooded habitats, a shift probably associated with reproduction. Wood density did not affect fish habitat use, as fish densities were similar across wooded habitats. In contrast, habitat heterogeneity significantly affected fish densities; more adult chubs and minnows were observed in complex habitats, whereas juvenile chubs and minnowroaches clearly preferred less complex habitats. We conclude that the targeted maintenance of instream wood structures to ensure habitat heterogeneity is a key‐action for the successful conservation of riverine fish populations.     

Legal personality and economic livelihood of the Whanganui River: a call for community entrepreneurship

ABSTRACT

Legislation in New Zealand dictates that the Whanganui River is a living entity and a legal person. Guardians uphold the river’s environmental, social, cultural and economic well-being. We provide a conceptual discussion of the river’s economic well-being, understood as the mutual enhancement of natural and human elements through community entrepreneurship that is based on human and non-human capabilities. We discuss human economic activity that preserves the right of the river to be free from pollution and form an integral part of the Māori culture and tradition, the improvement of Māori living conditions, and their rights to self-determination and prior consent.     

Biochemical Analysis of Leukocytes after In Vitro and In Vivo Activation with Bacterial and Fungal Pathogens Using Raman Spectroscopy

Biochemical information from activated leukocytes provide valuable diagnostic information. In this study, Raman spectroscopy was applied as a label-free analytical technique to characterize the activation pattern of leukocyte subpopulations in an in vitro infection model. Neutrophils, monocytes, and lymphocytes were isolated from healthy volunteers and stimulated with heat-inactivated clinical isolates of Candida albicans, Staphylococcus aureus, and Klebsiella pneumoniae. Binary classification models could identify the presence of infection for monocytes and lymphocytes, classify the type of infection as bacterial or fungal for neutrophils, monocytes, and lymphocytes and distinguish the cause of infection as Gram-negative or Gram-positive bacteria in the monocyte subpopulation. Changes in single-cell Raman spectra, upon leukocyte stimulation, can be explained with biochemical changes due to the leukocyte’s specific reaction to each type of pathogen. Raman spectra of leukocytes from the in vitro infection model were compared with spectra from leukocytes of patients with infection (DRKS-ID: DRKS00006265) with the same pathogen groups, and a good agreement was revealed. Our study elucidates the potential of Raman spectroscopy-based single-cell analysis for the differentiation of circulating leukocyte subtypes and identification of the infection by probing the molecular phenotype of those cells.     

Potassium deficiency,a “smart” cellular switch for sustained high yield hydrogen production by the green alga Scenedesmus obliquus

Hydrogen is considered to be the future optimal energy carrier, and is expected to contribute to the growth of the world's economy by facilitating a stable supply of energy. The ability of green algae to produce hydrogen was discovered 74 years ago. Since then, several attempts were made, to increase hydrogen production yields, sulfur starvation being the best known. The main concern during these attempts was that the achievable increase in yield was not sustainable. In this contribution, potassium deficiency is presented as a biochemical/bioenergetic switch for a sustained high yield of hydrogen production via the photosynthetic apparatus. Potassium can partially be replaced by sodium in the majority of biochemical processes and as a result the system remains functional. However, sodium cannot replace potassium in the conversion of glucose to starch. This fact significantly increased the yield of hydrogen production through the Photosystem II independent pathway, since electrons originating from the metabolism of glucose are used in the continuous donation to the plastoquinone-pool of the photosynthetic electron chain. Additionally, PSII inactivation (and therefore the inhibition of O₂-production), the further synthesis and over activation of Photosystem I and plastidic hydrogenase, generated a sustained increase in hydrogen production, mainly through the PSII-independent pathway. The self regulation of these multistage processes in hermitically closed static systems of Scenedesmus obliquus cultivation, permitted the establishment of anoxic conditions and the continuous electron supply to highly activated hydrogenase, resulting in the sustained high yield hydrogen production and paving the way for future usage in an industrial scale application.     

Anti-Apoptotic and Antioxidant Activities of the Mitochondrial Estrogen Receptor Beta in N2A Neuroblastoma Cells

Estrogens are steroid hormones that play a crucial role in the regulation of the reproductive and non-reproductive system physiology. Among non-reproductive systems, the nervous system is mainly affected by estrogens due to their antioxidant, anti-apoptotic, and anti-inflammatory activities, which are mediated by membranous and nuclear estrogen receptors, and also by non-estrogen receptor-associated estrogen actions. Neuronal viability and functionality are also associated with the maintenance of mitochondrial functions. Recently, the localization of estrogen receptors, especially estrogen receptor beta, in the mitochondria of many types of neuronal cells is documented, indicating the direct involvement of the mitochondrial estrogen receptor beta (mtERβ) in the maintenance of neuronal physiology. In this study, cell lines of N2A cells stably overexpressing a mitochondrial-targeted estrogen receptor beta were generated and further analyzed to study the direct involvement of mtERβ in estrogen neuroprotective antioxidant and anti-apoptotic actions. Results from this study revealed that the presence of estrogen receptor beta in mitochondria render N2A cells more resistant to staurosporine- and H₂O₂-induced apoptotic stimuli, as indicated by the reduced activation of caspase-9 and -3, the increased cell viability, the increased ATP production, and the increased resistance to mitochondrial impairment in the presence or absence of 17-β estradiol (E2). Thus, the direct involvement of mtERβ in antioxidant and anti-apoptotic activities is documented, rendering mtERβ a promising therapeutic target for mitochondrial dysfunction-associated degenerative diseases.     

Activation of Peripheral Blood Mononuclear Cells and Leptin Secretion: New Potential Role of Interleukin-2 and High Mobility Group Box (HMGB)1

Activation of innate immunity and low-grade inflammation contributes to hyperglycemia and an onset of Type 2 Diabetes Mellitus (T2DM). Interleukin-2 (IL-2), leptin, High Mobility Group Box-1 (HMGB-1), and increased glucose concentrations are mediators of these processes also by modulating peripheral blood mononuclear cells (PBMCs) response. The aim of this study was to investigate if HMGB-1 and IL-2 turn on PBMCs and their leptin secretion. In isolated human PBMCs and their subpopulations from healthy individuals and naïve T2DM patients, leptin release, pro-inflammatory response and Toll-like Receptors (TLRs) activation was measured. After treatment with IL-2 and HMGB1, NK (Natural Killer) have the highest amount of leptin secretion, whilst NK-T have the maximal release in basal conditions. TLR4 (TAK242) and/or TLR2 (TLR2-IgA) inhibitors decreased leptin secretion after IL-2 and HMGB1 treatment. A further non-significant increase in leptin secretion was reported in PBMCs of naive T2DM patients in response to IL-2 and HMGB-1 stimulation. Finally, hyperglycemia or hyperinsulinemia might stimulate leptin secretion from PBMCs. The amount of leptin released from PBMCs after the different treatments was enough to stimulate the secretion of IL-1β from monocytes. Targeting leptin sera levels and secretion from PBMCs could represent a new therapeutic strategy to counteract metabolic diseases such as T2DM.     

Searching biosignal databases by content and context: Research Oriented Integration System for ECG Signals (ROISES)

Technological advances in textile, biosensor and electrocardiography domain induced the wide spread use of bio-signal acquisition devices leading to the generation of massive bio-signal datasets. Among the most popular bio-signals, electrocardiogram (ECG) possesses the longest tradition in bio-signal monitoring and recording, being a strong and relatively robust signal. As research resources are fostered, research community promotes the need to extract new knowledge from bio-signals towards the adoption of new medical procedures. However, integrated access, query and management of ECGs are impeded by the diversity and heterogeneity of bio-signal storage data formats. In this scope, the proposed work introduces a new methodology for the unified access to bio-signal databases and the accompanying metadata. It allows decoupling information retrieval from actual underlying datasource structures and enables transparent content and context based searching from multiple data resources. Our approach is based on the definition of an interactive global ontology which manipulates the similarities and the differences of the underlying sources to either establish similarity mappings or enrich its terminological structure. We also introduce ROISES (Research Oriented Integration System for ECG Signals), for the definition of complex content based queries against the diverse bio-signal data sources.