Effect Of Pool Size Research Articles

Resource Management and Pricing for Cloud Computing Based Mobile Blockchain With Pooling

In a public blockchain system applying Proof of Work (PoW), the participants need to compete with their computing resources for reward, which is challenging for resource-limited devices. Mobile blockchain is proposed to facilitate the application of blockchain for mobile service, in which the lightweight devices can participate mining by renting resources from the Cloud Computing Service Provider (CCSP), but CCSP usually does not have the information about the demand preference of users. In this paper, a contract model is adopted to address the cloud computing resource allocation and pricing problem in the mobile blockchain. In particular, an adverse selection contract solution is proposed to overcome the information asymmetry problem, and resource pooling is introduced to improve the stability of users rewards. Simulation results show that the information asymmetry problem is well overcome by adverse selection contract so that CCSP can obtain more utility than linear pricing contracts. Furthermore, the resource pooling could effectively improve the users and CCSPs utilities. When the size of the mining pool is large enough, it can achieve an improvement effect of more than 10 times. The effect of pool size and user type distribution on CCSPs utility is also studied.

Laboratory evaluation of stable isotope labeling of Culicoides (Diptera: Ceratopogonidae) for adult dispersal studies

BackgroundStable isotope labeling is a promising method for use in insect mark-capture and dispersal studies. Culicoides biting midges, which transmit several important animal pathogens, including bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV), are small flies that develop in various semi-aquatic habitats. Previous Culicoides dispersal studies have suffered from the limitations of other labeling techniques, and an inability to definitively connect collected adult midges to specific immature development sites.ResultsAdult C. sonorensis were successfully labeled with 13C and 15N stable isotopes as larvae developing in a semi-aquatic mud substrate in the laboratory. High and low-dose isotope treatments for both elements significantly enriched midges above the background isotope levels of unenriched controls. Enrichment had no effect on C. sonorensis survival, though a slight (~ 5 day) delay in emergence was observed, and there was no significant effect of pool size on 13C or 15N enrichment levels.ConclusionsStable isotope labeling is life-long, and does not interfere with natural insect behaviors. Stable isotope enrichment using 13C or 15N shows promise for Culicoides dispersal studies in the field. This method can be used to identify adult dispersal from larval source habitat where a midge developed. It may be possible to detect a single enriched midge in a pool of unenriched individuals, though further testing is needed to confirm the sensitivity of this method.

Sizing the pool of online users: a dynamic pricing model for online travel agencies

In the modern travel market, online travel agencies (OTAs) compete intensively for online users who are valuable resources that support the OTAs’ long-term development. To expand their pool of online users, a few OTAs use aggressive pricing strategies (e.g., providing extremely low price for newly enlisted customers). However, such approach can create other management issues (e.g., financial burden). Noting that pricing strategies for sizing the pool of online users are less addressed by current literature, this paper considers a dynamic pricing problem in which an OTA actively optimizes entrance prices for newly enlisted customers to encourage them to join the pool. The essence of this problem is how to achieve an adequately sized pool supporting long-term profit through dynamic pricing. By analysing this problem, several findings on the interplay between price choosing and pool sizing are obtained. First, we proved the monotonicity of the optimal entrance price relative to the pool size, which demonstrates the positive effect of pool size on pricing decisions. Second, we showed that the optimal entrance price would be lower than operational cost, resulting in negative profits from newly enlisted customers when the pool size is smaller than a breakeven point. Third, we characterised the steady-state pool size and revealed the eventual convergence of the pool size and the pricing decisions. This result implies that the OTA has two pricing strategies, namely, penetration and constant.

The influence of pool size on species diversity and water chemistry in temporary rock pools on Domboshawa Mountain, northern Zimbabwe

The effect of pool size (area and depth) on species diversity and physicochemical characteristics of rock pool habitats on Domboshawa Mountain, northern Zimbabwe, was studied from December 2006 to May 2007. Pools were categorised based on maximum depth. Pool duration was a key factor structuring pool communities, driving their species diversity and nutrient content. Active predatory insects (Coleoptera, Odonata, Hemiptera) and zooplankton (Cladocera, Copepoda, Rotifera species) were associated with long-lived pools. As pool duration increased, early phytoplankton communities dominated by short-residence green algae were replaced by blue-green algae. The number of species present increased as pool area increased. Using depth as a proxy for disturbance, species composition in rock pools was influenced by the duration of inundation. A unique rock pool community with a filter-feeding component dominated by Cladocera, and from which large branchiopods were absent, is described. Nutrient status and community diversity in rock pools are determined by pool size, and pool depth, a proxy for habitat duration, is a major structuring factor in these temporary aquatic habitats.

Refuge size, group living and symbiosis: testing the “resource economic monopolization” hypothesis with the shrimp Betaeus lilianae and description of its partnership with the crab Platyxanthus crenulatus

Theory predicts that refuge size is most relevant in driving the population distribution of marine organisms. Relatively small refuges are expected to harbor single or pairs of conspecifics because defense against intruders is energetically inexpensive. Relatively large shelters should harbor aggregations because guarding behaviors turn energetically expensive. Here, we used the intertidal shrimp Betaeus lilianae to test the hypothesis that species inhabiting large refuges live in aggregations and not solitarily or in pairs. Also, we provided information on the lifestyle of this species, specifically regarding a newly discovered partnership with the crab Platyxanthus crenulatus. In agreement with theoretical expectations, Betaeus lilianae was found living in aggregations in rock pools, characterized by their large size. Shrimp aggregations featured female-biased sex ratios more frequently than expected by chance alone and had no particular complex social structure. There was no effect of pool size and shrimp group size on sex ratio and no significant relationship between the difference in body size of the largest and second largest male and shrimp group size was observed. Relative growth analyses showed that the major claw had positive allometry in males and females but relative claw growth was greater in males. The information above permitted rejecting several alternative hypotheses on the mating system of B. lilianae: it is neither socially monogamous nor features a promiscuous pure-search mating system. Additional studies are needed to reveal the mating behavior of the studied species. Field observations and laboratory experiments demonstrated that B. lilianae associate preferentially with the crab P. crenulatus.

Diagnostic algorithm for HBV safe transfusion.

Nucleic acid testing (NAT) has been introduced in blood donation screening in the late 1990s and was progressively extended with the availability of commercial assays initially for HCV, to HIV-1 and more recently to HBV1, 2. The main objective of HCV and HIV-1 RNA screening was the detection of window period infections (WP) for viruses that replicate very quickly with a viral load doubling time of 14 and 20 hours, respectively3. As a result, substantial increase in concentration of viral genomes is achieved in a short period of time ( 10E4IU/mL. Under such circumstances, the dilution factor introduced by pooling 24–96 plasma samples from individual donations did not substantially affect the identification of HCV and HIV-1 WP infections. However, plasma pooling being introduced for the economic purpose of decreasing the cost of NAT, several cases of HIV-1 transmission by lack of assay sensitivity related to sample pooling were reported4–6. Despite these few failures, the impact of NAT for HCV and HIV-1 reduced the residual risk of transfusion-transmission of these viruses below 1 per million donations in most developed countries where it was introduced2, 7. The issue of decreased sensitivity due to sample pooling became considerably more critical when HBV DNA screening was added to HCV and HIV-1 in triplex assays able to simultaneously detect all three viral genomes. Contrary to the relatively simple situation of HCV and HIV-1 where nearly 100% of samples containing viral RNA after the WP were seropositive for virus specific antibodies, discrepancies between serological HBV screening with HBsAg and DNA were found with considerable frequency8. Depending on the studies and the HBV genotype, 2–15% of HBV infected samples contained HBsAg without detectable DNA9 or DNA without detectable HBsAg10. As a result, 65–95% of potentially infectious HBV-containing donations were reactive to both types of assays. In addition, during the window period, the viral replication doubling time is considerably longer than for HCV and HIV-1 (estimated between 2 to 3 days) and it takes several weeks before viral load reaches concentrations ranging between 10E3 to 10E5 IU/mL and HBsAg becomes detectable3, 11. In this situation, the effect of pool size becomes more critical for WP identification. In addition, preliminary data collected in the past 10 years as well as more recent data obtained in areas where HBV DNA was screened in blood donor populations revealed substantial numbers of what is now known as 'occult' HBV infection (OBI) or carriage. This condition is defined as viral DNA without detectable HBsAg observed after the initial period of primary infection and most of the time accompanied by the presence of anti-HBc12. OBIs identified in apparently healthy blood donors have been further studied and characterised serologically, molecularly and to some extent clinically8, 13–15. OBIs are found mostly in older men, the viral load is generally below 1,000 IU/mL, in most cases <100 IU/mL, accompanied by anti-HBc and normal ALT level. Approximately half of these cases also carry anti-HBs indicating viral persistence in otherwise resolved infections. In very few cases, OBI may be negative for both anti-HBc and anti-HBs corresponding to 'primary' occult HBV infection16, which is defined as acute HBsAg negative infection. The very low viral load observed in most OBIs has two important consequences: 1. sample pooling considerably reduces the yield of cases and affects blood safety improvement; 2. It complicates the screening algorithm as well as the confirmation process. The present review will focus on the issue of confirmation of blood donation samples positive for HBV DNA but negative for HBsAg.

Feasibility of pooled-sample testing for the detection of porcine reproductive and respiratory syndrome virus antibodies on serum samples by ELISA

Surveillance of porcine reproductive and respiratory syndrome (PRRS) in negative sow farms is usually performed by testing for the presence of antibodies against PRRS virus in serum with a commercial ELISA test. The objective of this study was to evaluate the feasibility of pooling serum samples for detection of PRRS virus antibodies by ELISA. The effect of pool size on the sensitivity and specificity of the ELISA test was evaluated by testing true positive samples and false positive samples, respectively, diluted in negative sera. The effect of three different cut-off values for the interpretation of the diagnostic test (0.4, 0.3 and 0.2) was evaluated as well. Furthermore, the obtained sensitivity and specificity estimates were used to calculate the herd sensitivity and herd specificity of surveillance protocols in different scenarios. The results showed that pooling serum samples to detect PRRSV antibodies resulted in a decrease in sensitivity and an increase in specificity, compared to testing individual samples, while the reduction of the s/ p cut-off value recommended by the manufacturer (0.4) had the opposite effect. We describe an approach that can increase the herd sensitivity of a surveillance protocol for breeding herds, while maintaining high herd specificity and low testing costs. This can be achieved by sampling a larger number of animals and running the samples in pools. Therefore, the conventional monitoring protocols based on ELISA on individual samples can be improved by using pooled-sample testing.

Assessing PAH exposure in feral finfish from the Northwest Atlantic

Polycyclic aromatic hydrocarbon (PAH) concentrations were examined in small finfish (<30 cm) represented by capelin, sand lance, American plaice, yellowtail flounder and herring collected opportunistically in various NAFO divisions. Analyses were performed on whole fish and in a portion of the samples; concentrations in internal organs were compared to the rest of the carcass. The effect of pool size, size differences within and between species, lipid content and location were examined to interpret PAH concentrations. Measurements were carried out before the development of the Hibernia oil fields and represent baseline levels for future comparison. Limits in assessing future risk that could be due to discharges of produced water or accidental oil spills are also discussed. Increasing knowledge on the bioaccumulation of PAH, on the production of bile metabolites, the formation of DNA-adducts and of the potential toxic effects associated with PAH will lead to better ecosystem management and protection for future generations.

A113 横型PCCS 2次側水プール内多次元沸騰流解析 : プールサイズの影響(オーガナイズドセッション2 : 複雑な流れにおける熱・物質伝達)

A113 横型PCCS 2次側水プール内多次元沸騰流解析 : プールサイズの影響(オーガナイズドセッション2 : 複雑な流れにおける熱・物質伝達)

Pool size, job stressors, and health problems: A study of data entry clerks

A study was conducted of the health problems of two groups of data entry clerks drawn from 39 government agencies’ pools. One group was formed of 182 clerks who worked in large pools, whereas the second one was composed of 87 clerks in small pools. The clerks who worked in large pools were characterized by a higher rate of occurrence of symptoms of mental health problems (measured by the Ilfeld Index), as well as a higher degree of use of sleeping pills and tranquilizers, than those who worked in the small pools. The effect of pool size was indirect and originated from the more intense job Stressors found in the large pools: greater pressure to increase output, more fragmented work, and bureaucratic work relationships. A more extensive analysis showed the lack of recognition and mobility as a characteristic of all work pools and a major factor of mental health problems.

Lymphopoiesis in the rat. I. The effect of pool size on lymphocyte production.

AbstractA method is described for measuring lymphopoiesis that enables the production of recirculating and non‐recirculating small lymphocytes to be estimated simultaneously. Using this technique, experiments were undertaken to determine whether the production of recirculating cells is influenced by the number present in the recirculating lymphocyte pool. The results suggest that neither a massive lymphocyte transfusion nor depletion of the pool by whole body irradiation or chronic lymph drainage affect the rate at which recirculating small lymphocytes are generated.

The effect of pool size on recombination in phage

The effect of pool size on recombination in phage

Effect of pool size of acid-soluble deoxyribosyl compounds upon trans-N-deoxyribosidase activity in Lactobacillus leichmannii

Effect of pool size of acid-soluble deoxyribosyl compounds upon trans-N-deoxyribosidase activity in Lactobacillus leichmannii