Behavioural contrast sensitivity in Octopus tetricus was measured in the range of 0.05-12 cycles per degree (cpd) using a fixation reflex. We show that the contrast sensitivity reaches its maximum ...(between 1 and 4%) at 0.3 cpd, and decreases to approximately half of the maximum value at the lowest spatial frequency. Reduction of sensitivity at low spatial frequency is a signature of lateral inhibition in visual systems. In vertebrates and insects, lateral inhibition helps to overcome the bottleneck of encoding information into spikes. In octopus, photoreceptors generate spikes themselves and are directly connected to the brain through their axons. Therefore, the neural processing occurring in the octopus brain cannot help overcome the bottleneck of encoding information into spikes. We conclude that, in octopus, either the lateral inhibition occurs in the brain after information has been encoded into spikes, or photoreceptors inhibit each other. This is the first time behavioural contrast sensitivity has been measured in a cephalopod.
The chemical composition of thermokarst lake ecosystem components is a crucial indicator of current climate change and permafrost thaw. Despite high importance of macrophytes in shallow permafrost ...thaw lakes for control of major and trace nutrients in lake water, the trace element (TE) partitioning between macrophytes and lake water and sediments in the permafrost regions remains virtually unknown. Here we sampled dominant macrophytes in thermokarst lakes of discontinuous and continuous permafrost zones in the Western Siberia Lowland (WSL) and measured major and trace elements in plant biomass, lake water, lake sediments and sediment porewater. All six plant species (Hippuris vulgaris L., Glyceria maxima (Hartm.) Holmb., Comarum palustre L., Ranunculus spitzbergensis Hadac, Carex aquatilis Wahlenb s. str., Menyanthes trifoliata L.) sizably accumulated macronutrients (Na, Mg, Ca), micronutrients (B, Mo, Nu, Cu, Zn, Co) and toxicants (As, Cd). Accumulation of other trace elements, including rare earth elements (REE), in macrophytes relative to pore waters and sediments was highly variable among species. Using miltiparametric statistics, we described the behavior of ТЕ across two permafrost zones and identified several group of elements depending on their sources in the lake ecosystems and their affinity to sediments and macrophytes. Under future climate warming and shifting the permafrost border to the north, we anticipate an increasing uptake of heavy metals and lithogenic low mobile elements such as Ti, Al, Cr, As, Cu, Fe, Ni, Ga, Zr, and REEs by macrophytes in the discontinuous permafrost zone and Ba, Zn, Pb and Cd in the continuous permafrost zone. This may eventually diminish transport of metal micronutrients and geochemical tracers from soils to lakes and rivers and further to the Arctic Ocean.
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•Six macrophytes actively accumulated macronutrient and toxicants relative to lake sediments.•Accumulation of trace elements, including rare earth elements (REE) strongly varied among macrophytes species.•Climate warming may enhance accumulation of trace metals in aquatic plants of thermokarst lakes.•Enhanced uptake of metals by macrophytes due to permafrost thaw may decrease element export from soils to rivers.
Cancer virotherapy is an alternative therapeutic approach based on the viruses that selectively infect and kill tumor cells. Vaccinia virus (VV) is a member of the
Poxviridae
, a family of enveloped ...viruses with a large linear double-stranded DNA genome. The proven safety of the VV strains as well as considerable transgene capacity of the viral genome, make VV an excellent platform for creating recombinant oncolytic viruses for cancer therapy. Furthermore, various genetic modifications can increase tumor selectivity and therapeutic efficacy of VV by arming it with the immune-modulatory genes or proapoptotic molecules, boosting the host immune system, and increasing cross-priming recognition of the tumor cells by T-cells or NK cells. In this review, we summarized the data on bioengineering approaches to develop recombinant VV strains for enhanced cancer immunotherapy.
Over a century ago workers such as J. Lubbock and K. von Frisch developed behavioural criteria for establishing that non-human animals see colour. Many animals in most phyla have since then been ...shown to have colour vision. Colour is used for specific behaviours, such as phototaxis and object recognition, while other behaviours such as motion detection are colour blind. Having established the existence of colour vision, research focussed on the question of how many spectral types of photoreceptors are involved. Recently, data on photoreceptor spectral sensitivities have been combined with behavioural experiments and physiological models to study systematically the next logical question: ‘what neural interactions underlie colour vision?’ This review gives an overview of the methods used to study animal colour vision, and discusses how quantitative modelling can suggest how photoreceptor signals are combined and compared to allow for the discrimination of biologically relevant stimuli.
The development of perspective diagnostic techniques in medicine requires efficient high-throughput biological sample analysis methods. Here, we present an inline cartridge extraction that ...facilitates the screening rate of mass spectrometry shotgun lipidomic analysis of tissue samples. We illustrate the method by its application to tumor tissue identification in neurosurgery. In perspective, this high-performance method provides new possibilities for the investigation of cancer pathogenesis and metabolic disorders.
Chromatin remodeling is an essential part of transcription initiation. We show that at heat shock gene promoters functional interactions between individual ATP-dependent chromatin remodeling ...complexes play critical role in both nucleosome displacement and Pol II recruitment. Using HSP12, HSP82 and SSA4 gene promoters as reporters, we demonstrated that while inactivation of SNF2, a critical ATPase of the SWI/SNF complex, primarily affects the HSP12 promoter, depletion of STH1- a SNF2 homolog from the RSC complex reduces histone displacement and abolishes the Pol II recruitment at all three promoters. From these results, we conclude that redundancy between SWI/SNF and RSC complexes is only partial and likely is affecting different chromatin remodeling steps. While inactivation of other individual ATP-dependent chromatin remodeling complexes negligibly affects reporter promoters, combinatorial inactivation of SNF2 and ISW1 has a synergistic effect by diminishing histone loss during heat induction and eliminating Pol II recruitment. Importantly, it also eliminates preloading of HSF on HSP82 and SSA4 promoters before heat shock and diminishes HSF binding during heat shock. These observations suggest that prior action of chromatin remodeling complexes is necessary for the activator binding.
By means of mixing reaction calorimetry the enthalpy of the complexes formation between Ag+ ions and DNA and dsRNA was measured. It was shown that Ag+ ions are able to form two types of complexes (I ...and II) with dsRNA. Using the method of the competitive reaction with chloride ions the stability constants of complex formation were obtained for dsRNA-Ag+ complexes for different temperatures. These measurements gave the delta H and delta S values for both complexes: delta HI = -74,9 +/- 7,1 kjouls/mol, delta SI = -100.0 +/- 25.0 jouls/mol deg; delta HII = -39,8 +/- 4,2 kjouls/mol, delta SII = +2 +/- 14 jouls/mol deg. The calorimetric results of delta H determination are the same within the limits of experimental errors. The enthalpy term of dsRNA-Ag+ complexes proved to bring the main contribution into the free energy of complex formation.
Drawing on experimental games and surveys conducted with students at two universities in Russia, we compare the behavioral, attitudinal, and demographic traits of students seeking public sector ...employment to the traits of their peers seeking jobs in the private sector. Contrary to similar studies conducted in other high-corruption contexts, such as India, we find evidence that students who prefer a public sector career display less willingness to cheat or bribe in experimental games as well as higher levels of altruism. However, disaggregating public sector career paths reveals distinctions between the federal civil service and other types of public sector employment, with federal government positions attracting students who exhibit some similarities with their peers aspiring to private sector careers. We discuss multiple interpretations consistent with our findings, each of which has implications for the creation of effective anti-corruption policies and for understanding of state capacity in contexts where corruption is widespread.
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