Determination of LC50 of copper in Litopenaeus vannamei

We determined the LC50 of copper (as CUSO_4) and it's Maximum Allowable Concentration (MAC) for Litopenaeus vannamei. The study was performed in 2003 for which bioassays were used for acute toxicity tests in a period of 96 hours during which water parameters such as water temperature, pH, dissolved oxygen, hardness, alkalinity were also measured. Ten treatments and three replicates for each treatment were used. A LC50 of 86.71, 27.28, 7.98 and 3.90mg/1 and also Maximum Allowable Concentration of 8.671, 2.728, 0.798 and 0.390mg/1 were determined at 24, 48, 72 and 96 hours post exposure. Results showed that L. vannamei is relatively resistant to copper. Hence, short period application of copper to white shrimp farms for controlling algal bloom is judged harmless to the fish

Effect of different dietary levels of plant protein on growth indexes of white Leg shrimp

The influence of different dietary levels of plant protein (30, 50 and 70%) on growth indices of White Leg Shrimp (Litopenaeus vannamei) fed with an original 38 percent protein was assessed and compared with that of the commercial shrimp diet. The average weight gain at the end of the culture period in treatment 1 (30% plant protein and 70% animal protein), was 5.89 plus or minus 0.06 grams, for treatment 2 (50% plant protein and 50% animal protein), was 6.22 plus or minus 0.25 grams, for treatment 3 (70% plant protein and 30% animal protein), was 6.19 plus or minus 0.24 grams and for the control treatment (20% plant protein and 80% animal protein), was 6.42 plus or minus 0.40 grams. Our study of the influence of experimental and control diets on growth indices including growth rate (GR), food conversion ratio (FCR), protein efficiency ratio (PER), specific growth rate (SGR), and average daily gain (ADG), demonstrated that the indices were better in the control compared to the treatments. No significant difference was found among the treatments and between the treatments and the control for the indices (P>0.05). The percent of net protein utilization (NPU) in treatment 1 was significantly more than other treatments (P<0.05). We also found that the application of diets containing 50% plant protein (with 20% soybean meal) and 70% plant protein (with 41.72% soybean meal) can decrease diet costs. Cost of one kilogram of pellet in treatments 1, 2, 3 were 83.3%, 68.3% and 53.3% lower than the control diet respectively. Decrease of cost in treatment 2 and 3, in comparison to control in terms of lowering shrimp production cost is very important

External Periodic Driving of Large Systems of Globally Coupled Phase Oscillators

Large systems of coupled oscillators subjected to a periodic external drive occur in many situations in physics and biology. Here the simple, paradigmatic case of equal-strength, all-to-all sine-coupling of phase oscillators subject to a sinusoidal external drive is considered. The stationary states and their stability are determined. Using the stability information and numerical experiments, parameter space phase diagrams showing when different types of system behavior apply are constructed, and the bifurcations marking transitions between different types of behavior are delineated. The analysis is supported by results of direct numerical simulation of an ensemble of oscillators

ٍEfficiency of mating disruption for controlling the leopard moth, Zeuzera pyrina L. (Lep.: Cossidae), in walnut orchards

Leopard moth, Zeuzera pyrina L. (Lep.: Cossidae), is a key pest of walnut in Iran. The efficiency of mating disruption by two commercial products including Isonet® Z and Zeumat Universe® was evaluated in 2011 in East Azerbaijan and Kerman provinces. In each hectar, 300-600 pheromone dispensers for mating disruption were attached to the trees before the emergence of adults. Three pheromone traps were also installed in each plot to evaluate the orientation disruption before the adults' emergence. The pheromone traps did not capture any adult in the plots where mating disruption was performed during the experiment in both provinces while the traps caught the adults in the control plots. This result confirmed the efficiency of the used number of products for orientation disruption of the males. The averages of the number of larval entrances on the branches of plots where mating disruption was conducted by Isonet® Z, Zeumat Universe® and control were respectively 0.18 ± 0.03, 0.13 ± 0.02 and 0.45 ± 0.04 in Kerman province, 0.18 ± 0.03, 0.33 ± 0.04 and 0.63 ± 0.07 in East Azarbaiejan province and 0.18 ± 0.02, 0.2 ± 0.02 and 0.52 ± 0.04 (average ± S. E.) for the pooled data of both regions. There was a significant difference among the averages (P < 0.01).The results showed the efficiency of mating disruption technique by both products for reducing the damage of the pest even after one year. The number of larval entrances on the branches of the trees in mating disruption plots was 60-70% less than control plots. The results confirmed that the mating disruption with 300 pheromone dispensers of each product is efficient for reducing the damage of the pest in the walnut orchards

Last-male sperm precedence in Rhynchophorus ferrugineus (Olivier): observations in laboratory mating experiments with irradiated males

The Red PalmWeevil (RPW)Rhynchophorus ferrugineus(Olivier 1790) is an invasive pest from southeastern Asia and Melanesia that in the last 30 years has spread widely in the Middle East and Mediterranean Basin. Its stem-boring larvae cause great damage to several palm species of the Arecaceae family, many of which are economically important for agricultural and ornamental purposes. Therefore, great attention has recently been focused in studying this species to identify sustainable and effective eradication strategies, such as sterile insect technique (SIT). The rapid spread of RPW is associated with its high reproductive success. To evaluate the suitability of a SIT strategy, particular physiological and behavioral aspects of RPW reproduction, such as the presence of polyandry and post-copulatory sperm selection mechanisms, were investigated. To determine paternity of progeny from multiply mated females, double-crossing experiments were carried out confining individual females with either a wild-type male or a γ-irradiated male (Co-60). Fecundity and fertility of females were scored to evaluate post-copulatory sperm selection. Results showed that progeny were almost exclusively produced by the sperm of the second male, suggesting that a last-male sperm precedence is expressed at high levels in this species, and providing interesting insights for an area-wide RPW management strategy such as the SIT

Impacts of COVID-19 on the Energy System

This Briefing Paper explores the impact the COVID-19 pandemic had on the UK’s energy sector over the course of the first government-mandated national lockdown that began on 23 March 2020. Research from several aspects of the Integrated Development of Low-carbon Energy Systems (IDLES) programme at Imperial College London is presented in one overarching paper. The main aim is to determine what lessons can be learnt from that lockdown period, given the unique set of challenges it presented in our daily lives and the changes it brought about in energy demand, supply, and use. Valuable insights are gained into how working-from-home policies, electric vehicles, and low-carbon grids can be implemented, incentivised, and managed effectively

Somatic Integration of Single Ion Channel Responses of α7 Nicotinic Acetylcholine Receptors Enhanced by PNU-120596

Positive allosteric modulators of highly Ca2+-permeable α7 nicotinic acetylcholine receptors, such as PNU-120596, may become useful therapeutic tools supporting neuronal survival and function. However, despite promising results, the initial optimism has been tempered by the concerns for cytotoxicity. The same concentration of a given nicotinic agent can be neuroprotective, ineffective or neurotoxic due to differences in the expression of α7 receptors and susceptibility to Ca2+ influx among various subtypes of neurons. Resolution of these concerns may require an ability to reliably detect, evaluate and optimize the extent of α7 somatic ionic influx, a key determinant of the likelihood of neuronal survival and function. In the presence of PNU-120596 and physiological choline (∼10 µM), the activity of individual α7 channels can be detected in whole-cell recordings as step-like current/voltage deviations. However, the extent of α7 somatic influx remains elusive because the activity of individual α7 channels may not be integrated across the entire soma, instead affecting only specific subdomains located in the channel vicinity. Such a compartmentalization may obstruct detection and integration of α7 currents, causing an underestimation of α7 activity. By contrast, if step-like α7 currents are integrated across the soma, then a reliable quantification of α7 influx in whole-cell recordings is possible and could provide a rational basis for optimization of conditions that support survival of α7-expressing neurons. This approach can be used to directly correlate α7 single-channel activity to neuronal function. In this study, somatic dual-patch recordings were conducted using large hypothalamic and hippocampal neurons in acute coronal rat brain slices. The results demonstrate that the membrane electrotonic properties do not impede somatic signaling, allowing reliable estimates of somatic ionic and Ca2+ influx through α7 channels, while the somatic space-clamp error is minimal (∼0.01 mV/µm). These research efforts could benefit optimization of potential α7-PAM-based therapies

Deconvolution of Serum Cortisol Levels by Using Compressed Sensing

The pulsatile release of cortisol from the adrenal glands is controlled by a hierarchical system that involves corticotropin releasing hormone (CRH) from the hypothalamus, adrenocorticotropin hormone (ACTH) from the pituitary, and cortisol from the adrenal glands. Determining the number, timing, and amplitude of the cortisol secretory events and recovering the infusion and clearance rates from serial measurements of serum cortisol levels is a challenging problem. Despite many years of work on this problem, a complete satisfactory solution has been elusive. We formulate this question as a non-convex optimization problem, and solve it using a coordinate descent algorithm that has a principled combination of (i) compressed sensing for recovering the amplitude and timing of the secretory events, and (ii) generalized cross validation for choosing the regularization parameter. Using only the observed serum cortisol levels, we model cortisol secretion from the adrenal glands using a second-order linear differential equation with pulsatile inputs that represent cortisol pulses released in response to pulses of ACTH. Using our algorithm and the assumption that the number of pulses is between 15 to 22 pulses over 24 hours, we successfully deconvolve both simulated datasets and actual 24-hr serum cortisol datasets sampled every 10 minutes from 10 healthy women. Assuming a one-minute resolution for the secretory events, we obtain physiologically plausible timings and amplitudes of each cortisol secretory event with R[superscript 2] above 0.92. Identification of the amplitude and timing of pulsatile hormone release allows (i) quantifying of normal and abnormal secretion patterns towards the goal of understanding pathological neuroendocrine states, and (ii) potentially designing optimal approaches for treating hormonal disorders.National Science Foundation (U.S.). Graduate Research Fellowship ProgramNational Institutes of Health (U.S.) (NIH DP1 OD003646)National Science Foundation (U.S.) (0836720)National Science Foundation (U.S.). Office of Emerging Frontiers in Research and Innovation (EFRI-0735956

Assessment of perforated steel beam-to-column connections subjected to cyclic loading

This paper presents a study of welded perforated beam-to-column connections, forming the so-called RWS systems. The effect of using non-standard novel web opening configurations of variable depths and positions is investigated. The ease of manufacturing process together with the improvements on the structural behaviour foreshadows the enhancements gained using these perforated members. It is concluded that using large perforations is an effective way of improving the behaviour of connections enhancing their ductility and their energy dissipation capacity. The connections with novel openings outperform the conventional ones; hence they can be suitably used in the aseismic design of steel frames

Study on effect of enriched Artemia with (HUFA) on reproductive parameters and comparing with current method (used marine worm) in Litopenaeus vannamei

Nowadays, the use of live food enrichment is very common in aquaculture and as a practical method introduced. Artemia a potential food source and quality is suitable, it will have used for feeding fish and crustaceans (shrimp). In this study, Artemia enriched with unsaturated fatty acids used for increase the sexual maturity of the white leg shrimp (Litopenaeus vannamei). Thus, the young brood stocks transferred to Bandarga Research station. In order to achieve optimal weight, Brood stocks were feeding by food concentrate and food frozen fresh. In this study such as 3 treatments each with 3 replicates, which brood stocks were stocking in the fiberglass thank with density 2 to 3 (pieces/m^2). They were feeding with meals different including 1) squid , pen shale and marine polychaeta worm (Perinereis nuntia), 2) squid , pen shale and Artemia biomass "fransiscan", 3) squid , pen shale and Artemia biomass enriched with unsaturated fatty acid (HUFA) SPARI SELCO solution after were eye ablation. The results showed that sexual maturity increased in the brood stocks fed with Artemia enriched which with significantly higher brood stocks fed with Artemia biomass and the marine worm (P 0.05). The other hand, histological studies showed that brood stocks fed with Artemia enriched than other two treatments contain were many mature follicles ready for ovulation. However, there was more absolute fecundity in the brood stocks fed with Artemia enriched, but don't found any significant differences in competition with other two treatments (P>0.05). In addition, during this period, measured and recorded all factors physicochemical water and environment daily. Following this study showed that if the Artemia enriched as part of the diet can both caused eliminate unsaturated fatty acid deficiency diet and improved ovarian development and increase sexual maturity brood stocks female in a short interval. Finally, the results analyzed with statistical software spss 9.0, one way ANOVA and Tukey test