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Copepods are an important part of the marine food web because of their high biomass productivity and nutrient turnover rate compared to other zooplankton in the marine ecosystem. Despite their great ecological role in the ocean, there is only limited information available on the consequences of ocean acidification (OA) induced by the future increase in CO 2 on the planet. More specifically, there is almost no information about the impact of OA on the European copepod Calanipeda aquaedulcis Kritschagin, 1873. Therefore, the present investigation hypothesized that OA would not produce negative multigenerational effects on the survival and reproductive performance of this copepod species. Here we assessed, the multigenerational (F1 and F2) effect of OA on eight important reproductive traits (maturity, prosome length, fertility, egg release, hatching success, survival rate, reproductive performance, and the total number of adults per generation). For this study, C. aquaedulcis were collected from the Guadalquivir River (southwest of Spain) and were exposed to four different pH gradients (pH 8.1 as control and pH 7.5, 7.0, 6.5 as acidified conditions) to mimic the future seawater acidification scenarios. The survival rate from nauplius to adult, C. aquaedulcis was significantly reduced by pHs and across generations. Besides, results also indicated that there were marked effects on fertility, reflected by a significantly lower number of eggs per female in each generation. Similarly, hatching success also showed a decreasing pattern towards low pH, and importantly, F1 females had lower hatching success than F0 females. While a beneficial parental effect was detected in the offspring in response to OA, it was insufficient to offset the negative effects caused by it. The findings presented here appear to have ecological significance, as decreasing the reproductive performance of copepods may have a negative impact on the marine food web, as ichthyofaunal feeding and growth are heavily reliant on this component of the food web. [Display omitted] • Low pH reduced fertility of C. aquaedulcis , affecting the length of ovigerous females. • Stress due to OA increases the shedding of gravid females from their unhatched egg sacs. • Hatching success is reduced at low pH, while there is no variation in age at first reproduction. • Beneficial parental effects were detected in the offspring in response to OA. • The development of the nauplius phase showed significant delays in OA treatments. [ABSTRACT FROM AUTHOR]

In this paper, an investigation of snake robot movement scenario has been discussed and analyzed. Angular velocity, snake robot movement trends and motion shape are involved in this investigation by implementation of serpentine locomotion. Experiment the real snake to extract motion and force data is quite difficult to handle. Thus a new model of the test bed for robot handling and gathering data are proposed in this research. Grid like elastic strings with a particular tension are installed on the transparent table to extract the snake motion direction data to enable the snake force calculation. Then shape measurement belt and kinect sensor will establish the motion data. A snake robot is developed in this paper to perform the preparatory experimental work to go for the real snake experiment involving snake locomotion in future. [ABSTRACT FROM AUTHOR]

Ocean acidification (OA) has received more attention in the marine research community in recent years than any other topic. Excess carbon dioxide makes the ocean more acidic, threatening marine ecosystems. There has been little research on the impact of OA on crustaceans, particularly on their physiological and potential ecosystem-level consequences. Thus, we investigated the impacts of OA on the physiological and biochemical characteristics of the estuarine amphipod Ampelisca brevicornis. Ovigerous amphipods were harvested from nature and maintained in the laboratory to produce juveniles, which were then further reared to obtain the mature adults (F0) and successive offspring (F1). For this study, four pH treatments (pH 8.1, 7.5, 7.0, and 6.5) mimicking future OA were evaluated to understand the physiological and biochemical effects on the organisms. The findings of this study suggest that A. brevicornis is more vulnerable to OA than was previously established in short-term trials. The survival was significantly reduced as pH decreased over time and a significant interaction between pH and time was observed. Survival was higher in F1 than in F0 juveniles and vice versa in terms of growth. Animal's physiological responses such as growth, burrowing behavior, locomotor activity, swimming speed, ventilation rate and reproductive performance were negatively influenced by acidification. These physiological characteristics can be linked to the oxidative stress induced by global change conditions because excess of free radicals degrade cell functioning, affecting species' biochemical and physiological performance. These alterations may have long-term negative impacts, with ecological consequences. The results of this study provide baseline information regarding the effect of OA on this keystone crustacean that may be useful in simulating the impacts of OA to develop different conceptual models for a better understanding of the consequences and implications of climate change in the future for managing marine ecosystems. [Display omitted] • Acidification had a deleterious impact on physiological and biochemical responses. • Ampelisca altered the age and size of reproductive maturity. • Antioxidant mechanisms were overcome in predicted acidified conditions. • The impact on growth had serious consequences on reproductive performance. • Survival was high in generation F1 than F0 juveniles and vice-versa in growth. [ABSTRACT FROM AUTHOR]

Lightning is one of the frequent catastrophic hazards to people and properties across the world. Bangladesh is one of the major lightning prone countries in the world. Information regarding the spatial, temporal and demographic distribution of lightning casualties is required to develop mitigation policies to minimize the impacts of lightning. This study aims to analyse the spatial, temporal and demographic distribution of lightning-related casualties in the northeastern part of Bangladesh from 2016 to 2018. The database of lightning casualties was developed from a variety of sources including government and private agencies. Records dating from 2016 to 2018 indicate that about 78 and 60 people have been killed and injured, respectively by lightning strikes. The highest number of lightning fatalities were reported in the districts of Kishoreganj (31%), Habiganj (18%) and Sunamganj (15%). The overall fatality rate is 1.76 per million people per year, and fatality density rate is 0.00388 per million people km−2 year−1. The majority of fatalities and injuries occurred within the early morning 0800 and early evening 1700 at local time. The number of fatalities was higher in April–May during the pre-monsoon season. The maximum number of people died by lightning during farming activities, followed by fishing, boating or bathing in water bodies. The findings of the study are highly beneficial to the administrator and policymakers to develop lightning mitigation plans, improve public awareness and lightning safety campaign to reduce the impacts of lightning hazards. • Spatio-temporal and demographic distribution of lightning casualties was assessed. • Geospatial techniques were used to process the data and map the casualties. • Identified the spatio-temporal and demographic distribution of lightning casualties. • The results of this study would be useful to develop mitigation policies. [ABSTRACT FROM AUTHOR]

The effect of membrane potential on plasma membrane damage generated by antimicrobial peptides (AMPs) is an important, yet poorly characterized, process. Here, we studied the effect of membrane potential (φ m) on pore formation by magainin 2 (Mag) in single giant unilamellar vesicles (GUVs) composed of dioleoylphosphatidylglycerol (DOPG)/dioleoylphosphatidylcholine (DOPC) membranes. Various membrane potentials in GUVs containing gramicidin A were generated as a result of K+ concentration gradients. First, we examined Mag-generated membrane permeation of the water-soluble fluorescent probe calcein in single DOPG/DOPC-GUVs in the presence of membrane potential. The results indicate that the rate constant (k p) of Mag-induced pore formation increased with increasing negative membrane potentials. Analysis of the rim intensity of single GUVs interacting with low concentrations of a fluorescent probe, carboxyfluorescein-labeled Mag (CF-Mag), using confocal laser scanning microscopy (CLSM) shows that the concentration of CF-Mag in the membrane greatly increased with negative membrane potentials. This indicates that the binding constant of CF-Mag to the membrane increased with more negative membrane potentials. To elucidate the location of Mag in a GUV with φ m during Mag-induced pore formation, we examined the interaction of Mag and a low concentration of a CF-Mag mixture with single GUVs containing the water-soluble fluorescent probe AF647 using CLSM. The data indicate that CF-Mag locates in the external leaflet of single GUVs until just before pore formation. Based on these data, we conclude that the increase in the surface concentration of Mag is one of the primary causes of the increase in k p with negative membrane potential. Unlabelled Image • Magainin 2 (Mag) caused leakage of calcein from GUVs under membrane potential, φ m. • Rate constant of Mag-induced pore formation (k p) increased as ∣ φ m ∣ increased. • Binding constant of CF-Mag to GUV membrane increased with an increase in ∣ φ m ∣. • Under φ m , Mag locates in outer leaflet of GUV until just before pore formation. • Increase in Mag surface concentration is one of main causes of the increase in k p. [ABSTRACT FROM AUTHOR]