Motion sensitive interneurons in the optomotor system of the fly

The three horizontal cells of the lobula plate of the blowflyCalliphora erythrocephala were studied anatomically and physiologically by means of cobalt impregnations and intracellular recordings combined with Procion and Lucifer Yellow injections. The cells are termed north, equatorial and south horizontal cell (HSN, HSE, HSS) and are major output neurons of the optic lobe. 1. The dendritic arborizations of the HSN, HSE, HSS reside in a thin anterior layer of the lobula plate and extend over the dorsal, equatorial and ventral parts of this neuropil, respectively. Due to the retinotopic organization of the optic lobe, these parts correspond anatomically to respective regions of the ipsilateral visual field. Homologue horizontal cells in both lobula plates of the same animal and in different animals are highly variable with respect to their individual dendritic branching patterns. They are extraordinarily constant, on the other hand, with regard to the position and size of their dendritic fields as well as their dendritic branching density distributions. Each cell covers about 40% of the total area of the lobula plate and shows the highest dendritic density near the lateral margin of the neuropil which subserves the frontal eye region. The axons of the horizontal cells are relatively short and large in diameter; they terminate in the posterior ventrolateral protocerebrum. 2. The horizontal cells are directionally selective motion sensitive visual interneurons responding preferentially to progressive (front to back) motion in the ipsilateral visual field with graded depolarization of their axons and superimposed action potentials. Stimulation with motion in the reverse direction leads to hyperpolarizing graded responses. The HSE and HSN are additionally activated by regressive motion in the contralateral visual field.     

Functional role of membrane-bound adenylyl cyclases and coupled to them receptors and G-proteins in regulation of fertility of spermatozoa

The cAMP-dependent signaling cascades play the key role in regulation of fertility of spermatozoa. Synthesis of cAMP in spermatozoa is realized both by soluble, and by transmembrane (membrane-bound) forms of adenylyl cyclases (AC). For the recent years numerous data appeared about the presence in spermatozoa at different stages of their maturation of a wide spectrum isoforms of membrane-bound AC and their regulation by hormones and hormone-like substances via the coupled to B-proteins receptors (GPCR). Agonists of GPCR in spermatozoa can be adenosine, biogenic amines, peptide hormones, odorants. Study of structural-functional organization and regulatory properties of AC of the signal system in spermatozoa is of great practical significance for reproductive technologies, as via the membrane-bound AC forms and signal cascades there are controlled such processes as motility and chemotaxis of spermatozoa, their capability for capacitation acrosomal reaction. In the review there are summarized and analyzed data on functioning and role of AC of signal system in spermatozoa of human and vertebrate animals and are discussed achievements and unsolved problems in this field.     

Field Enhancement of Tip with Spiral Nanostructure

Recently, tips suitable for illuminating from top to bottom have received great attraction due to high energy utilization and easiness of constituting array, which can increase scan efficiency to realize large-area rapid microprobe scan. In this work, we study the field enhancement on a cone tip with a planar Archimedes’ spiral nanostructure under an illumination of circularly polarized light. By means of a simulation based on phase matching theory and finite-difference time-domain, it is demonstrated that electric field intensity in close proximity to the tip, which is contributed by evanescent mode (EM) and propagating mode (PM) of surface plasmon polaritons (SPPs) induced from Archimedes’ spiral slits, increases 3 orders of magnitude than that of the incoming beam. The beam induced by the tip has a full width at half maximum of 10 nm (~0.015λ₀).     

A bibliometric investigation of life cycle assessment research in the web of science databases

Purpose

Over the past few decades, life cycle assessment (LCA) methodologies have been developed extensively, and there has been a growing interest in LCA research. However, as attested by scientific literature, few systematic, synthesizing, and visualizing studies have been found on LCA research which show how this field has evolved over time. The goal of this mainly bibliometric, empirical study is to get insight into publication performance of global LCA research, characterize its intellectual structure, and trace its evolution by using the bibliometric method with visual mapping.

Methods

Based on the data from the ISI Web of Science databases Science Citation Index Expanded (SCI-EXPANDED), Social Sciences Citation Index (SSCI), Conference Proceedings Citation Index—Science (CPCI-S) and Conference Proceedings Citation Index —Social Science & Humanities (CPCI-SSH) in the period of 1998–2013, bibliometric methods are used to investigate general development profiles of LCA research, while knowledge domain visualization technologies are employed to conduct a further co-citation analysis.

Results and discussion

The results and discussions of this research mainly shed light on (1) basic statistics of significant publication performances, (2) research focuses and their intellectual base in LCA research, (3) how the streams of research evolved during the whole period of interest.

Conclusions

A new work on systematic and synthesizing study is conducted in this research to evaluate and map LCA research-related context. Some salient scholarly journals and institutions are identified that have shown a significant impact during the exponential growth of LCA research in the past 16 years. Biofuel, process design, solid waste management, and livestock production-related LCA researches are the main areas where interest is surging, confirmed by the active citers in each specialty. Furthermore, from the perspective of science mapping, evolution of LCA research is traced and some pivot publications are identified, which work as structural holes for the LCA-research development in the given time window.     

Cancer-retina antigens — A new group of tumor antigens

Some photoreceptor proteins normally specific for the eye retina are aberrantly expressed in malignant tumors. These proteins include recoverin, visual rhodopsin, transducin, cGMP-phosphodiesterase 6 (PDE 6), cGMP-dependent cationic channels, guanylyl cyclase 1, rhodopsin kinase, and arrestin. By analogy with cancer-testis antigens, these photoreceptor proteins form the group of cancer-retina antigens. It is shown that an aberrant demethylation of the promoter region of recoverin is involved in the aberrant expression of this protein. The cascade Wnt5a → Frizzled-2 → transducin → PDE 6 is shown to function in skin melanoma cells, and this suggests that these cancer-retina antigens can play a functional role. The events accompanying the signal transduction in this cascade, including those involving calcium ions and cGMP-dependent protein kinase (protein kinase G), are discussed.     

GABA Pharmacology: The Search for Analgesics

Decades of research have been devoted to defining the role of GABAergic transmission in nociceptive processing. Much of this work was performed using rigid, orthosteric GABA analogs created by Povl Krogsgaard-Larsen and his associates. A relationship between GABA and pain is suggested by the anatomical distribution of GABA receptors and the ability of some GABA agonists to alter nociceptive responsiveness. Outlined in this report are data supporting this proposition, with particular emphasis on the anatomical localization and function of GABA-containing neurons and the molecular and pharmacological properties of GABA_A and GABA_B receptor subtypes. Reference is made to changes in overall GABAergic tone, GABA receptor expression and activity as a function of the duration and intensity of a painful stimulus or exposure to GABAergic agents. Evidence is presented that the plasticity of this receptor system may be responsible for the variability in the antinociceptive effectiveness of compounds that influence GABA transmission. These findings demonstrate that at least some types of persistent pain are associated with a regionally selective decline in GABAergic tone, highlighting the need for agents that enhance GABA activity in the affected regions without compromising GABA function over the long-term. As subtype selective positive allosteric modulators may accomplish these goals, such compounds might represent a new class of analgesic drugs.     

On the neuronal basis of figure-ground discrimination by relative motion in the visual system of the fly

It has been concluded in the preceding papers (Egelhaaf, 1985a, b) that two functional classes of output elements of the visual ganglia might be involved in figure-ground discrimination by relative motion in the fly: The Horizontal Cells which respond best to the motion of large textured patterns and the FD-cells which are most sensitive to small moving objects. In this paper it is studied by computer simulations (1) in what way the input circuitry of the FD-cells might be organized and (2) the role the FD-cells play in figure-ground discrimination. The characteristic functional properties of the FD-cells can be explained by various alternative model networks. In all models the main input to the FD-cells is formed by two retinotopic arrays of small-field elementary movement detectors, responding to either front-to-back or back-to-front motion. According to their preferred direction of motion the FD-cells are excited by one of these movement detector classes and inhibited by the other. The synaptic transmission between the movement detectors and the FD-cells is assumed to be non-linear. It is a common property of all these model circuits that the inhibition of the FD-cells induced by large-field motion is mediated by pool cells which cover altogether the entire horizontal extent of the visual field of both eyes. These pool cells affect the response of the FD-cells either by pre- or postsynaptic shunting inhibition. Depending on the FD-cell under consideration, the pool cells are directionally selective for motion or sensitive to motion in either horizontal direction. The role the FD-cells and the Horizontal Cells are likely to play in figure-ground discrimination can be demonstrated by computer simulations of a composite neuronal model consisting of the model circuits for these cell types. According to their divergent spatial integration properties they perform different tasks in figure-ground discrimination: Whereas the Horizontal Cells mainly mediate information on wide-field motion, the FD-cells are selectively tuned to efficient detection of relatively small targets. Both cell classes together appear to be sufficient to account for figure-ground discrimination as it has been shown by analysis at the behavioural level.     

VEGF: A potential target for hydrocephalus

Growth factors are primarily responsible for the genesis, differentiation and proliferation of cells and maintenance of tissues. Given the central role of growth factors in signaling between cells in health and in disease, it is understandable that disruption of growth factor-mediated molecular signaling can cause diverse phenotypic consequences including cancer and neurological conditions. This review will focus on the specific questions of enlarged cerebral ventricles and hydrocephalus. It is also well known that angiogenic factors, such as vascular endothelial growth factor (VEGF), affect tissue permeability through activation of receptors and adhesion molecules; hence, recent studies showing elevations of this factor in pediatric hydrocephalus led to the demonstration that VEGF can induce ventriculomegaly and altered ependyma when infused in animals. In this review, we discuss recent findings implicating the involvement of biochemical and biophysical factors that can induce a VEGF-mimicking effect in communicating hydrocephalus and pay particular attention to the role of the VEGF system as a potential pharmacological target in the treatment of some cases of hydrocephalus. The source of VEGF secretion in the cerebral ventricles, in periventricular regions and during pathologic events including hydrocephalus following hypoxia and hemorrhage is sought. The review is concluded with a summary of potential non-surgical treatments in preclinical studies suggesting several molecular targets including VEGF for hydrocephalus and related neurological disorders.     

Feral pigs as hosts for Amblyomma sculptum (Acari: Ixodidae) populations in the Pantanal,Mato Grosso do Sul,Brazil

The Pantanal in Brazil is the largest floodplain of the world. This ecosystem, rich in wildlife, has a large feral pig population. Such a large host biomass must have a strong influence on the parasite fauna. In this work, we evaluated the role of feral pigs in the maintenance of Amblyomma sculptum (formerly Amblyomma cajennense), the most prevalent tick species in the Pantanal. Tick infestations were evaluated on 243 feral pigs and their environment. The suitability of domestic pigs, representing their feral relatives, to A. sculptum adults and nymphs was assessed experimentally. Tick infestation of feral pigs was strongly associated with that of the environment: 96 and 97 % of the ticks, respectively, were A. sculptum. The infestation prevalence on this host species was close to 90 % in the dry season and 100 % in the wet season and mean infestation intensity was above 30 ticks in both seasons. Suitability of pigs as hosts for A. sculptum was shown by the high proportion of nymphs and female ticks found engorging on captured feral pigs and adequate biological parameters displayed by ticks from experimental infestations of domestic pigs. Other tick species on feral pigs, albeit in much lower numbers, were Amblyomma parvum and Ornithodorus rostratus. Results show that feral pigs feed a high proportion of the A. sculptum adults and nymphs in their territories and should be a target for tick-borne diseases studies. This is particularly relevant to public health because all the main tick species found on feral pigs are aggressive to humans as well.     

Conformational changes of recombinant human granulocyte-colony stimulating factor induced bypH and guanidine hydrochloride

Fluorescence and circular dichroism were used to follow thepH-dependent conformational changes of granulocyte colony stimulating factor (G-CSF). Tryptophan fluorescence of the spectra monitored at 344 nm, or after deconvolution of the emission spectra, at 345 nm, showed a decrease in intensity on going frompH 7 to 4, with a midtransitionpH of 5.8. On the other hand, tyrosine fluorescence measured either by the ratio of intensity at 308 nm to that at 344 nm, or by the fluorescence intensity at 303 nm after deconvolution of the spectra, increased in intensity as thepH was changed from 6 to 2.5, with a midtransitionpH of 4.5. Near UV circular dichroic spectra also showed changes betweenpH 7.5 and 4.5, which correlated with the transition monitored by the tryptophan fluorescence. The guanidine hydrochloride-induced conformational changes of G-CSF at fivepH values from 2.5 to 7.5 were also studied. Circular dichroic and fluorescence spectra revealed minor conformational changes by the addition of 1 or 2 M guanidine HCl at allpH values examined, while the major conformational transition occurred between 2 and 4 M guanidine hydrochloride. The secondary structure of the protein was most stable betweenpH 3.3 and 4.5. The guanidine HCl-induced denaturation of G-CSF involved more than a two-state transition, with detectable intermediate(s) present, and the structure of the intermediate(s) appeared to depend on thepH used. These results are consistent with thepH dependence of the structure described above, and demonstrate the complex conformational properties of G-CSF.     

Effect of Interparticle Field Enhancement in Self-Assembled Silver Aggregates on Surface-Enhanced Raman Scattering

The presence of so-called hot spots, regions with strongly enhanced electromagnetic field, is a critical property of a substrate enabling detection of surface-enhanced Raman scattering (SERS) signals at high enhancement levels. In this work, the effect of interparticle field enhancement on SERS signals was investigated comparing SERS spectra of ethylenediaminetetraacetic-disodium salt in the chemically produced colloids with isolated and aggregated silver nanoparticles using 473 and 532-nm wavelength excitation. The presence of aggregates in the colloidal solution resulted in SERS spectra that were insensitive to wavelength excitation and much richer in structural information and of higher resolution than the corresponding SERS spectra for the colloid with isolated nanoparticles. The experimental SERS spectra were found to be consistent with the finite-difference time-domain simulation results that explored the electromagnetic response of the isolated and aggregated nanoparticles. These results provide more evidence to suggest that the aggregate formation offers favorable electromagnetic properties increasing sensitivity of Raman spectroscopy.     

Myeloid-derived suppressor cells and their role in CTLA-4 blockade therapy

Immune checkpoints are a series of inhibitory pathways that are crucial for modulating the intensity and duration of immune response. Among these checkpoints, cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4) has been shown to be a key regulator of the early activation of naïve and memory T cells. Immune checkpoint blockade is emerging as one of the most promising therapeutic approaches directed toward the activation of the immune response against tumors. The first of these therapies that has been FDA approved is ipilimumab, a fully human monoclonal antibody that blocks CTLA-4. The in cis effects that CTLA-4 blockade has on T cells have been properly described, but there are still questions to be answered regarding the indirect or in trans effects. One of the alternative cellular populations that may play a role in the outcome of CTLA-4 blockade therapy is myeloid-derived suppressor cells (MDSCs), which have recently been associated with clinical outcome in advanced melanoma. In addition to this, MDSCs have been shown to be decreased in number and functional potential after treatment with ipilimumab. A better clarification of what effects CTLA-4 blockade may have on these cellular populations is likely to provide insights on possible predictive biomarkers for CTLA-4 blockade therapy.     

Plants and environment: Two decades of research at the Canberra phytotron

The research carried out at the Canberra phytotron, CERES, during the first twenty years of its operation is reviewed as a case study of the opportunities, problems and value of phytotron research. The climatic responses of a large number of species, both wild and domesticated, are examined as well as those of fungal and viral pathogens and rhizobial symbionts. Some aspects of the design of CERES are briefly considered, and a few aspects of the variation between plants in climatic response, with the C₄ photosynthetic syndrome taken as a case history of the linkages between biochemistry, anatomy and response to climate. Research in ecology, forestry, horticulture, plant pathology, rhizobial microbiology, anatomy and ultrastructure—and specific aspects of biochemistry, plant nutrition and genetics—are reviewed to indicate the range of botanical disciplines which can profit from access to a phytotron. The ecological research at CERES, much of it with trees and perennial grasses, particularly highlights the value of combining field and phytotron studies. Work on seed proteins, hybrid vigor and plant growth regulators is also reviewed. The next part of the paper considers the effects of the major environmental factors, temperature, daylength, irradiance, atmospheric CO₂ level and water stress, together with their interactions and the problems of correlating phytotron and field responses. The effect of these factors on the various processes of growth and development are considered, and the stages of development most sensitive to them. An evolutionary perspective on yield potential is then discussed, leading to a consideration of photosynthesis, translocation, partitioning and storage organ growth as yield-determining processes. The final part considers the uses of phytotrons in agricultural, horticultural and forestry research, in terms of examples from work at CERES on the manipulation of breeding systems, the clarification of plant breeding objectives, the use of phytotron conditions for selection, the prediction of adaptation and spread, and models for yield prediction and pest management. Several areas requiring more attention are identified, and some conclusions are drawn on the value of access to a phytotron such as CERES for botanical research of many kinds.     

Composition and ecology of deep-water coral associations

Between 1966 and 1978 SCUBA investigations were carried out in French Polynesia, the Red Sea, and the Caribbean, at depths down to 70 m. Although there are fewer coral species in the Caribbean, the abundance of Scleractinia in deep-water associations below 20 m almost equals that in the Indian and Pacific Oceans. The assemblages of corals living there are described and defined as deep-water coral associations. They are characterized by large, flattened growth forms. Only 6 to 7 % of the species occur exclusively below 20 m. More than 90 % of the corals recorded in deep waters also live in shallow regions. Depth-related illumination is not responsible for depth differentiations of coral associations, but very likely, a complex of mechanical factors, such as hydrodynamic conditions, substrate conditions, sedimentation etc. However, light intensity determines the general distribution of hermatypic Scleractinia in their bathymetric range as well as the platelike shape of coral colonies characteristic for deep water associations. Depending on mechanical factors,Leptoseris, Montipora, Porites andPachyseris dominate as characteristic genera in the Central Pacific Ocean,Podabacia, Leptoseris, Pachyseris andCoscinarea in the Red Sea,Agaricia andLeptoseris in the tropical western Atlantic Ocean.     

Dynamic expression of a Hydra FGF at boundaries and termini

Guidance of cells and tissue sheets is an essential function in developing and differentiating animal tissues. In Hydra, where cells and tissue move dynamically due to constant cell proliferation towards the termini or into lateral, vegetative buds, factors essential for guidance are still unknown. Good candidates to take over this function are fibroblast growth factors (FGFs). We present the phylogeny of several Hydra FGFs and analysis of their expression patterns. One of the FGFs is expressed in all terminal regions targeted by tissue movement and at boundaries crossed by moving tissue and cells with an expression pattern slightly differing in two Hydra strains. A model addressing an involvement of this FGF in cell movement and morphogenesis is proposed: Hydra FGFf-expressing cells might serve as sources to attract tissue and cells towards the termini of the body column and across morphological boundaries. Moreover, a function in morphogenesis and/or differentiation of cells and tissue is suggested.     

MicroRNA Expression Signatures Determine Prognosis and Survival in Glioblastoma Multiforme—a Systematic Overview

Despite advances in our knowledge about glioblastoma multiforme (GBM) pathology, clinical challenges still lie ahead with respect to treatment in GBM due to high prevalence, poor prognosis, and frequent tumor relapse. The implication of microRNAs (miRNAs) in GBM is a rapidly expanding field of research with the aim to develop more targeted molecular therapies. This review aims to present a comprehensive overview of all the available literature, evaluating miRNA signatures as a function of prognosis and survival in GBM. The results are presented with a focus on studies derived from clinical data in databases and independent tissue cohorts where smaller samples sizes were investigated. Here, miRNA associated to longer survival (protective) and miRNA with shorter survival (risk-associated) have been identified and their signatures based on different prognostic attributes are described. Finally, miRNAs associated with disease progression or survival in several studies are identified and functionally described. These miRNAs may be valuable for future determination of patient prognosis and could possibly serve as targets for miRNA-based therapies, which hold a great potential in the treatment of this severe malignant disease.