Plant and supplementary food sources effect the development of <Emphasis Type="Italic">Dicyphus errans</Emphasis> (Hemiptera: Miridae)

Dicyphus errans (Wolff) (Hemiptera: Miridae) is an omnivorous predator of several pests attacking tomato and other vegetable crops. The nymphal development of D. errans was studied in the presence of Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) eggs with or without a water source and in the presence of a leaf of cucumber, eggplant or tomato supplemented with variable food types (E. kuehniella eggs, Artemia sp. cysts, pollen or milk powder) or without the provision of any food. Water provision was found to be essential for the completion of nymphal development even when animal food was offered to predators. When nymphs foraged on leaves in the absence of any food type, development was significantly more favoured on eggplant and cucumber than on tomato. E. kuehniella eggs and Artemia sp. cysts enhanced development of D. errans in comparison to milk powder and pollen. Development and female weight were improved when the food types were offered to the nymphs on a plant leaf than when were provided together with only water. This study contributes to understanding the importance of water vs. plant feeding for the development of D. errans and reveals implications for its mass rearing and application in biological control.     

Wheat plant selection for high yields entailed improvement of leaf anatomical and biochemical traits including tolerance to non-optimal temperature conditions

Assessment of photosynthetic traits and temperature tolerance was performed on field-grown modern genotype (MG), and the local landrace (LR) of wheat (Triticum aestivum L.) as well as the wild relative species (Aegilops cylindrica Host.). The comparison was based on measurements of the gas exchange (A/c_i, light and temperature response curves), slow and fast chlorophyll fluorescence kinetics, and some growth and leaf parameters. In MG, we observed the highest CO₂ assimilation rate \(\left( {{A_{{\text{C}}{{\text{O}}_2}}}} \right),\) electron transport rate (J_max) and maximum carboxylation rate \(\left( {{V_{{{\text{C}}_{\hbox{max} }}}}} \right)\). The Aegilops leaves had substantially lower values of all photosynthetic parameters; this fact correlated with its lower biomass production. The mesophyll conductance was almost the same in Aegilops and MG, despite the significant differences in leaf phenotype. In contrary, in LR with a higher dry mass per leaf area, the half mesophyll conductance (g_m) values indicated more limited CO₂ diffusion. In Aegilops, we found much lower carboxylation capacity; this can be attributed mainly to thin leaves and lower Rubisco activity. The difference in CO₂ assimilation rate between MG and others was diminished because of its higher mitochondrial respiration activity indicating more intense metabolism. Assessment of temperature response showed lower temperature optimum and a narrow ecological valence (i.e., the range determining the tolerance limits of a species to an environmental factor) in Aegilops. In addition, analysis of photosynthetic thermostability identified the LR as the most sensitive. Our results support the idea that the selection for high yields was accompanied by the increase of photosynthetic productivity through unintentional improvement of leaf anatomical and biochemical traits including tolerance to non-optimal temperature conditions.     

Haplotype analysis of vernalization loci in European barley germplasm reveals novel <Emphasis Type="Italic">VRN-H1</Emphasis> alleles and a predominant winter <Emphasis Type="Italic">VRN-H1/VRN-H2</Emphasis> multi-locus haplotype

In barley, variation in the requirement for vernalization (an extended period of low temperature before flowering can occur) is determined by the VRN-H1, -H2 and -H3 loci. In European cultivated germplasm, most variation in vernalization requirement is accounted for by alleles at VRN-H1 and VRN-H2 only, but the range of allelic variation is largely unexplored. Here we characterise VRN-H1 and VRN-H2 haplotypes in 429 varieties representing a large portion of the acreage sown to barley in Western Europe over the last 60 years. Analysis of genotype, intron I sequencing data and growth habit tests identified three novel VRN-H1 alleles and determined the most frequent VRN-H1 intron I rearrangements. Combined analysis of VRN-H1 and VRN-H2 alleles resulted in the classification of seventeen VRN-H1/VRN-H2 multi-locus haplotypes, three of which account for 79% of varieties. The molecular markers employed here represent powerful diagnostic tools for prediction of growth habit and assessment of varietal purity. These markers will also allow development of germplasm to test the behaviour of individual alleles with the aim of understanding the relationship between allelic variation and adaptation to specific agri-environments.     

The Role of the DNA Damage Response Kinase Ataxia Telangiectasia Mutated in Neuroprotection

It has been estimated that a human cell is confronted with 1 million DNA lesions every day, one fifth of which may originate from the activity of Reactive Oxygen Species (ROS) alone [1,2]. Terminally differentiated neurons are highly active cells with, if any, very restricted regeneration potential [3]. In addition, genome integrity and maintenance during neuronal development is crucial for the organism. Therefore, highly accurate and robust mechanisms for DNA repair are vital for neuronal cells. This requirement is emphasized by the long list of human diseases with neurodegenerative phenotypes, which are either caused by or associated with impaired function of proteins involved in the cellular response to genotoxic stress [4-8]. Ataxia Telangiectasia Mutated (ATM), one of the major kinases of the DNA Damage Response (DDR), is a node that links DDR, neuronal development, and neurodegeneration [2,9-12]. In humans, inactivating mutations of ATM lead to Ataxia-Telangiectasia (A-T) disease [11,13], which is characterized by severe cerebellar neurodegeneration, indicating an important protective function of ATM in the nervous system [14]. Despite the large number of studies on the molecular cause of A-T, the neuroprotective role of ATM is not well established and is contradictory to its general proapoptotic function. This review discusses the putative functions of ATM in neuronal cells and how they might contribute to neuroprotection.     

First-Person Perspective Virtual Body Posture Influences Stress: A Virtual Reality Body Ownership Study

In immersive virtual reality (IVR) it is possible to replace a person’s real body by a life-sized virtual body that is seen from first person perspective to visually substitute their own. Multisensory feedback from the virtual to the real body (such as the correspondence of touch and also movement) can also be present. Under these conditions participants typically experience a subjective body ownership illusion (BOI) over the virtual body, even though they know that it is not their real one. In most studies and applications the posture of the real and virtual bodies are as similar as possible. Here we were interested in whether the BOI is diminished when there are gross discrepancies between the real and virtual body postures. We also explored whether a comfortable or uncomfortable virtual body posture would induce feelings and physiological responses commensurate with the posture. We carried out an experiment with 31 participants in IVR realized with a wide field-of-view head-mounted display. All participants were comfortably seated. Sixteen of them were embodied in a virtual body designed to be in a comfortable posture, and the remainder in an uncomfortable posture. The results suggest that the uncomfortable body posture led to lesser subjective BOI than the comfortable one, but that participants in the uncomfortable posture experienced greater awareness of their autonomic physiological responses. Moreover their heart rate, heart rate variability, and the number of mistakes in a cognitive task were associated with the strength of their BOI in the uncomfortable posture: greater heart rate, lower heart rate variability and more mistakes were associated with higher levels of the BOI. These findings point in a consistent direction—that the BOI over a body that is in an uncomfortable posture can lead to subjective, physiological and cognitive effects consistent with discomfort that do not occur with the BOI over a body in a comfortable posture.     

Green fluorescent protein – Tagged HCV non-enveloped capsid like particles: Development of a new tool for tracking HCV core uptake

Circulating ‘free’ non-enveloped Hepatitis C virus (HCV) core protein has been demonstrated in HCV-infected patients, and HCV subgenomes with deletions of the envelope proteins have been previously identified. Initial studies from our laboratory, previously published, indicated that expression of HCV core in insect cells can direct the formation of capsid-like particles lacking the envelope glycoproteins. These protein nanospheres, morphologically similar to natural capsids, were shown to be taken up by human hepatic cells and to produce cell-signalling events. To follow the intracellular fate of these particles we fused the core protein to eGFP. We demonstrate that the chimeric proteins core₁₇₃-eGFP, eGFP-core₁₉₁ and eGFP-core₁₇₃ can be efficiently expressed, self-assembled, and form fluorescent non-enveloped capsid-like particles. By using confocal microscopy and FACS analysis, we provide evidence that the fluorescent nanospheres can not only enter human hepatic cells – the main target of HCV – but also human immune cells such as T and B lymphocytes, as well as human myeloid leukaemia cells differentiated along the monocyte/macrophage-like pathway. The fluorescent particles might thus be used to trace the intracellular trafficking of naked HCV capsids as showed by live microscopy and to further understand their biological significance.