Vibration Alert Bracelet for Notification of the Visually and Hearing Impaired

This paper presents the prototype of an electronic vibration bracelet designed to help the visually and hearing impaired to receive and send emergency alerts. The bracelet has two basic functions. The first function is to receive a wireless signal and respond with a vibration to alert the user. The second function is implemented by pushing one button of the bracelet to send an emergency signal. We report testing on a prototype system formed by a mobile application and two bracelets. The bracelets and the application form a complete system intended to be used in retirement apartment communities. However, the system is flexible and could be expanded to add new features or to serve as a research platform for gait analysis and location services. The medical and professional potential of the proposed system is that it offers a simple, modular, and cost-effective alternative to all the existing medical devices with similar functionality currently on the market. The proposed system has an educational potential as well: it can be used as a starting point for capstone projects and demonstration purposes in schools to attract students to STEM disciplines

Reduced expression of the v-SNAREs AtVAMP71/AtVAMP7C gene family in Arabidopsis reduces drought tolerance by suppression of abscisic acid-dependent stomatal closure

Stomatal closure during water stress is a major plant mechanism for reducing the loss of water through leaves. The opening and closure of stomata are mediated by endomembrane trafficking. The role of the vacuolar trafficking pathway, that involves v-SNAREs of the AtVAMP71 family (formerly called AtVAMP7C) in stomatal movements, was analysed. Expression of AtVAMP711–14 genes was manipulated in Arabidopsis plants with sense or antisense constructs by transformation of the AtVAMP711 gene. Antisense plants exhibited decreased stomatal closure during drought or after treatment with abscisic acid (ABA), resulting in the rapid loss of leaf water and tissue collapse. No improvement was seen in plants overexpressing the AtVAMP711 gene, suggesting that wild-type levels of AtVAMP711 expression are sufficient. ABA treatment induced the production of reactive oxygen species (ROS) in guard cells of both wild-type and antisense plants, indicating that correct hormone sensing is maintained. ROS were detected in nuclei, chloroplasts, and vacuoles. ABA treatment caused a significant increase in ROS-containing small vacuoles and also in plastids and nuclei of neighbouring epidermal and mesophyll cells. Taken together, our results show that VAMP71 proteins play an important role in the localization of ROS, and in the regulation of stomatal closure by ABA treatment. The paper also describes a novel aspect of ROS signalling in plants: that of ROS production in small vacuoles that are dispersed in the cytoplasm

The involvement of poly(ADP-ribose) polymerase in the oxidative stress responses in plants

AbstractIn plants many biotic and abiotic stresses can cause secondary oxidative stress. Earlier work showed that, depending on the severity of the oxidative stress, plants can activate either cell protective genes or programmed cell death (PCD). Poly(ADP-ribose) polymerase (PARP) has been implicated as one of the enzymes in the apoptotic pathways induced by DNA damaging agents or oxidative stress. We show that in cultured soybean cells, PARP is involved in responses to mild and severe oxidative stresses, by mediating DNA repair and PCD processes, respectively. Addition of PARP inhibitors reduced the degree of cell death triggered by H2O2. Two windows of NAD consumption after H2O2 treatment were detected. Experiments with transient overexpression of Arabidopsis PARP cDNA promoted DNA repair and inhibited cell death caused by mild oxidative stress. However, following severe stress PARP overexpression increased cell death. Expression of antisense PARP produced the opposite effects: an increase in DNA nicks and inhibition of cell death at high, but not mild doses of H2O2

Capacity to control oxidative stress-induced caspase-like activity determines the level of tolerance to salt stress in two contrasting maize genotypes

The response of two maize (Zea mays L.) genotypes, named GR (salt-tolerant) and SK (salt-sensitive), to salt stress (150 mM NaCl) was investigated under controlled environmental growth conditions. Genotype SK experienced more oxidative damage than the GR genotype when subjected to salt stress, which corresponded to higher O2 - production rate and H2O2 content in the SK genotype than the GR genotype. Induction of caspase-like activity in response to salt stress was stronger in the SK genotype than in the GR genotype. On the other hand, induction of antioxidant enzyme activity to scavenge O2 - and H2O2 in response to salt stress was weaker in the SK genotype than in the GR genotype. Consequently, the higher level of oxidative damage in the SK genotype in response to salt stress was manifested as more extensive cell death and biomass reduction in the SK genotype than it was in the GR genotype. Our results suggest that a direct relationship exists between salt stress-induced oxidative damage and cell death-inducing caspase-like activity, with tolerance to the salt stress being controlled by the efficiency of the plant antioxidant enzymes in limiting salt stress-induced oxidative damage and thus limiting cell death-inducing caspase-like activity. © 2012 Franciszek Górski Institute of Plant Physiology, Polish Academy of Sciences, Kraków