Recent advances in sturgeon nutrition.

Sturgeons are fish species of biological and economical importance, and most of them are endangered, vulnerable or rare because of their large size, late sexual maturity, long period between spawning, and longevity. These unique biological characteristics make them highly susceptible to overfishing, degradation of habitat and spawning ground, and contamination of water and sediments by pollutants. The objective of the current review is not to exhaustively include all studies on sturgeon nutrient requirements and utilizations conducted under laboratory conditions, but to critique some studies and update previous reviews. The goal is to provide a basis for recommendations for future research so that these important fish species can be managed and produced sustainably. Energy, protein, lipid carbohydrate, vitamin, and mineral requirements and utilizations were reviewed or critiqued. Future studies to develop suitable chemically defined diets to support good growth of sturgeon are urgently needed. Furthermore, future experiments should be designed systematically with more consideration on within and among studies and within and among different species of sturgeon. Finally, future experiments should be designed with a systematic approach with multiple doses (inputs) and multiple responses (outputs) at several levels of hierarchical organization in a biological system using traditional biochemical and modern molecular techniques and computer modeling with proper experimental design and methodology. This approach will provide a more realistic and holistic understanding of the mechanisms of nutrient requirements and utilizations, which will help us better manage wild sturgeon stocks and produce sturgeon more efficiently and sustainably under aquaculture conditions

Development of growth rate, body lipid, moisture, and energy models for white sturgeon (Acipenser transmontanus) fed at various feeding rates.

The objectives were to develop and evaluate: 1) growth rate models, 2) body lipid, moisture, and energy models for white sturgeon fed at various feeding rates (FR; % body weight [BW] per day) and then evaluate responses at proportions of optimum feeding rate (OFR) across increasing BW (g). For objective 1, 19 datasets from the literature containing initial BW, FR and specific growth rate (SGR; % BW increase per day) were used. For objective 2, 12 datasets from the literature (11 from objective 1) containing SGR, FR, final BW, body lipid (%), protein (%), ash (%), moisture (%), and energy (kJ/g) were used. The average rearing temperatures was 19.2 ± 1.5 °C (mean ± SD). The average nutrient compositions and gross energy of the diets were 45.7 ± 4.3% protein, 14.8 ± 3.2% lipid, and 20.4 ± 1.3 kJ/g, respectively. The logistic model was used for objectives 1 and 2 to develop a statistical relationship between SGR and FR, then an iterative technique was used to estimate OFR for each dataset. For objective 2, the statistical relationship between body lipid, energy, and moisture and FR was established. Using the OFR estimate, SGR, body lipid, energy and moisture were computed at various FR as a proportion of OFR. Finally, a nonparametric fitting procedure was used to establish relationships between SGR, body lipid, energy and moisture (responses) compared with BW (predictor) at various proportions of OFR. This allows visualization of the effect of under- or over-feeding on the various responses. When examining the differences between OFR at 100% and various proportions of OFR, SGR differences decrease and moisture differences increase as BW increases. Lipid and energy differences decrease as BW increases. To our knowledge, these are the first description of changes in nutrient compositions when white sturgeon are fed at various FR. Because physiological and behavioral properties that are unique to sturgeon, results from this study are specific to sturgeon under the conditions of this study and cannot be compared directly with salmonids even if some of the results are similar. This research provides insight to designing future nutritional studies in sturgeon

Responses of heat shock protein 70 and caspase-3/7 to dietary selenomethionine in juvenile white sturgeon.

An 8-week feeding trial was conducted to investigate the responses of juvenile white sturgeon (Acipenser transmontanus) to elevated dietary selenium (Se) based on the determination of the RNA/DNA ratio in muscle, heat shock protein 70 (Hsp70), and caspase-3/7 in muscle and/or liver tissues. Four semi-purified test diets were prepared by adding different levels of L-selenomethionine (0, 50, 100, and 200 mg/kg diet). The analytical determinations of total Se were 2.2, 19.7, 40.1, and 77.7 mg/kg diet. The sturgeon (initial body weight: 30 ± 2 g; mean ± SEM) were raised in indoor tanks provided with flow through freshwater (18-19 °C). There were three replicates for each dietary treatment with 25 fish per replicate. The liver and muscle tissues were collected at 4 and 8 weeks after feeding the test diets. A significant interaction between duration and levels of dietary Se exposures on RNA/DNA ratio in the muscle tissue was detected (P < 0.05). Although there was no significant main effect due to the duration of dietary Se exposures (i.e., 4 weeks versus 8 weeks) on muscle RNA/DNA ratio (P ≥ 0.05), the ratio was significantly decreased with increasing dietary Se levels. Significant main effects were caused by the duration and levels of dietary Se exposures on Hsp70 in both the muscle and liver tissues, with significant increases in Hsp70 due to a longer exposure (8 weeks) and higher levels (40.1 and 77.7 mg Se/kg diet) of dietary Se. The caspase-3/7 activity in the liver were significantly higher in fish fed the diets containing 40.1 and 77.7 mg Se/kg diet than those fed the other diets. The toxic thresholds of Se in the muscle were estimated to be 32.2 and 26.6 mg Se/kg for the depressed specific growth rate and the induced Hsp70 response in muscle, respectively. This result indicated that the Hsp70 response in muscle is a more sensitive biomarker than the SGR of sturgeon for evaluating Se toxicity in white sturgeon. Results of the current study suggest that a mechanism involved with the activation of stress protein production and apoptosis protects white sturgeon from the lethal effect of Se

Strong hydrogen bonding in organic synthesis

The preparation of phenacyl and para-phenylphenacyl esters, the reactions of carboxylic acids, phenols, 2-nitropropane and alcohols with alkyl halides in the presence of fluoride anion are described. The reactions are thought to be accelerated by the formation of hydrogen bonds between the fluoride anion and the organic electron acceptor. The fluoride ,carboxylic acids, fluoride-phenols and fluoride-2-nitropropane are better reaction systems than the fluoride-alcohol. The source of the fluoride anion and the choice of solvents are also discussed

Secondary Network Throughput Optimization of NOMA Cognitive Radio Networks Under Power and Secure Constraints

Recently, the combination of cognitive radio networks with the nonorthogonal multiple access (NOMA) approach has emerged as a viable option for not only improving spectrum usage but also supporting large numbers of wireless communication connections. However, cognitive NOMA networks are unstable and vulnerable because multiple devices operate on the same frequency band. To overcome this drawback, many techniques have been proposed, such as optimal power allocation and interference cancellation. In this paper, we consider an approach by which the secondary transmitter (STx) is able to find the best licensed channel to send its confidential message to the secondary receivers (SRxs) by using the NOMA technique. To combat eavesdroppers and achieve reasonable performance, a power allocation policy that satisfies both the outage probability (OP) constraint of primary users and the security constraint of secondary users is optimized. The closed-form formulas for the OP at the primary base station and the leakage probability for the eavesdropper are obtained with imperfect channel state information. Furthermore, the throughput of the secondary network is analyzed to evaluate the system performance. Based on that, two algorithms (i.e., the continuous genetic algorithm (CGA) for CR NOMA (CGA-CRN) and particle swarm optimization (PSO) for CR NOMA (PSO-CRN)), are applied to optimize the throughput of the secondary network. These optimization algorithms guarantee not only the performance of the primary users but also the security constraints of the secondary users. Finally, simulations are presented to validate our research results and provide insights into how various factors affect system performance

Secondary Network Throughput Optimization of NOMA Cognitive Radio Networks Under Power and Secure Constraints

Recently, the combination of cognitive radio networks with the nonorthogonal multiple access (NOMA) approach has emerged as a viable option for not only improving spectrum usage but also supporting large numbers of wireless communication connections. However, cognitive NOMA networks are unstable and vulnerable because multiple devices operate on the same frequency band. To overcome this drawback, many techniques have been proposed, such as optimal power allocation and interference cancellation. In this paper, we consider an approach by which the secondary transmitter (STx) is able to find the best licensed channel to send its confidential message to the secondary receivers (SRxs) by using the NOMA technique. To combat eavesdroppers and achieve reasonable performance, a power allocation policy that satisfies both the outage probability (OP) constraint of primary users and the security constraint of secondary users is optimized. The closed-form formulas for the OP at the primary base station and the leakage probability for the eavesdropper are obtained with imperfect channel state information. Furthermore, the throughput of the secondary network is analyzed to evaluate the system performance. Based on that, two algorithms (i.e., the continuous genetic algorithm (CGA) for CR NOMA (CGA-CRN) and particle swarm optimization (PSO) for CR NOMA (PSO-CRN)), are applied to optimize the throughput of the secondary network. These optimization algorithms guarantee not only the performance of the primary users but also the security constraints of the secondary users. Finally, simulations are presented to validate our research results and provide insights into how various factors affect system performance

New insights into India’s single stock futures markets

This study investigates correlations between India’s bustling single stock futures (SSFs) and its peculiar Badla mechanism. Data from the world’s most active SSF market, the National Stock Exchange (NSE) of India, are used. The results indicated that both the Badla mechanism and the introduction of SSFs seem to have contributed to the higher volatility of the spot markets. Our results show that the NSE’s success with SSFs can be attributed to the peculiar trading conventions of the Badla system. However, we propose that this success could come at the cost of market disability, suggesting that there is justification for strengthening market regulations

New insights into India’s single stock futures markets

This study investigates correlations between India’s bustling single stock futures (SSFs) and its peculiar Badla mechanism. Data from the world’s most active SSF market, the National Stock Exchange (NSE) of India, are used. The results indicated that both the Badla mechanism and the introduction of SSFs seem to have contributed to the higher volatility of the spot markets. Our results show that the NSE’s success with SSFs can be attributed to the peculiar trading conventions of the Badla system. However, we propose that this success could come at the cost of market disability, suggesting that there is justification for strengthening market regulations

Throughput Optimization for NOMA Energy Harvesting Cognitive Radio with Multi-UAV-Assisted Relaying under Security Constraints

This paper investigates the throughput of a non-orthogonal multiple access (NOMA)-based cognitive radio (CR) system with multiple unmanned aerial vehicle (UAV)-assisted relays under system performance and security constraints. We propose a communication protocol that includes an energy harvesting (EH) phase and multiple communication phases. In the EH phase, the multiple UAV relays (URs) harvest energy from a power beacon. In the first communication phase, a secondary transmitter (ST) uses the collected energy to send confidential signals to the first UR using NOMA. Simultaneously, a ground base station communicates with a primary receiver (PR) under interference from the ST. In the subsequent communication phases, the next URs apply the decode-and-forward technique to transmit the signals. In the last communication phase, the Internet of Things destinations (IDs) receive their signals in the presence of an eavesdropper (EAV). Accordingly, the outage probability of the primary network, the throughput of the secondary network, and the leakage probability at the EAV are analyzed. On this basis, we propose a hybrid search method combining particle swarm optimization (PSO) and continuous genetic algorithm (CGA) to optimize the UR configurations and the NOMA power allocation to maximize the throughput of the secondary network under performance and security constraints