885 research outputs found
From Minority Games to real markets
We address the question of market efficiency using the Minority Game (MG)
model. First we show that removing unrealistic features of the MG leads to
models which reproduce a scaling behavior close to what is observed in real
markets. In particular we find that i) fat tails and clustered volatility arise
at the phase transition point and that ii) the crossover to random walk
behavior of prices is a finite size effect. This, on one hand, suggests that
markets operate close to criticality, where the market is marginally efficient.
On the other it allows one to measure the distance from criticality of real
market, using cross-over times. The artificial market described by the MG is
then studied as an ecosystem with different_species_ of traders. This clarifies
the nature of the interaction and the particular role played by the various
populations.Comment: 9 pages, 7 figures, to appear in Quantitative Financ
In vitro evaluation of caseinophosphopeptides from different genetic variants on bone mineralization
Casein phosphopeptides (CPPs) have been shown to enhance calcium solubility and to increase the calcification by in vitro analyses. The aim of our study was to investigate the effects of four selected casein peptides, which differ in the number of phosphorylated serines, on osteoblast mineralization in vitro. The chosen peptides, related to different casein genetic variants, were obtained by chemical synthesis and tested on murine osteoblast cell line (MC3T3-E1). Our results suggest that the distinct peptides in protein hydrolysates may differentially affect calcium deposition in the extracellular matrix and that the genetic variation within the considered peptides is involved in their differential effect
COVID-19: Considerations about immune suppression and biologicals at the time of SARS-CoV-2 pandemic
The extent of the profound immunological and nonimmunological responses linked to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is currently being investigated worldwide due to the large burden associated with death due to SARS-CoV-2 and the short-term consequences of coronavirus disease 2019 (COVID-19). It has been hypothesized that patients on immunosuppressive treatments, including biologics, may have an augmented risk of being infected by SARS-CoV-2; however, there are currently no definitive data about biological drugs and COVID-19 in immune-mediated inflammatory diseases. Current epidemiological models developed to understand how long the COVID-19 epidemic may last are not conclusive and range from sustained epidemics to complete elimination. Nevertheless, even in the best-case scenario of apparent elimination, there is concordance about a possible contagion resurgence as late as 2024. Therefore, knowledge of the impact of SARS-CoV-2 on immune-mediated diseases and among patients treated with biologicals, together with the results of novel and promising COVID-19 treatment strategies targeting the virus and the host immune response (or both), will help us to best manage our patients during this pandemic over the next few years
Internet of robotic things : converging sensing/actuating, hypoconnectivity, artificial intelligence and IoT Platforms
The Internet of Things (IoT) concept is evolving rapidly and influencing newdevelopments in various application domains, such as the Internet of MobileThings (IoMT), Autonomous Internet of Things (A-IoT), Autonomous Systemof Things (ASoT), Internet of Autonomous Things (IoAT), Internetof Things Clouds (IoT-C) and the Internet of Robotic Things (IoRT) etc.that are progressing/advancing by using IoT technology. The IoT influencerepresents new development and deployment challenges in different areassuch as seamless platform integration, context based cognitive network integration,new mobile sensor/actuator network paradigms, things identification(addressing, naming in IoT) and dynamic things discoverability and manyothers. The IoRT represents new convergence challenges and their need to be addressed, in one side the programmability and the communication ofmultiple heterogeneous mobile/autonomous/robotic things for cooperating,their coordination, configuration, exchange of information, security, safetyand protection. Developments in IoT heterogeneous parallel processing/communication and dynamic systems based on parallelism and concurrencyrequire new ideas for integrating the intelligent “devices”, collaborativerobots (COBOTS), into IoT applications. Dynamic maintainability, selfhealing,self-repair of resources, changing resource state, (re-) configurationand context based IoT systems for service implementation and integrationwith IoT network service composition are of paramount importance whennew “cognitive devices” are becoming active participants in IoT applications.This chapter aims to be an overview of the IoRT concept, technologies,architectures and applications and to provide a comprehensive coverage offuture challenges, developments and applications
Analysis of 22 mutations within milk protein genes in Italian Friesian cattle
The bovine milk protein caseins, αS1-CN, β-CN, αS2-CN, and κ-CN are codified by four well characterized genes, named CSN1S1, CSN2, CSN1S2, and CSN3 respectively and clustered in a region of 250-kb of chromosome 6. A recent revision of milk protein nomenclature considering only protein polymorphisms indicates 8 αS1-CN, 4 αS2-CN, 12 β-CN, and 11 κ-CN variants within the genus Bos. Other mutations were found in the non-coding regions of the cluster, such as the promoter regions or the 3'UTR. Many of these polymorphisms, together with others in various genes, such as the one coding for β-lactoglobulin (LGB), show important associations with different milk quality traits. Analyzing all these polymorphisms could help clarify the role of both the casein haplotype and the other polymorphisms in milk composition and cheese-making properties, and could explain which polymorphisms are really or mostly involved. The mPCR-LDR-UA approach recently developed to test simultaneously 22 SNPs in DNA regions responsible for milk protein expression was used to type 250 Italian Friesian cattle. In perfect agreement with literature, the most frequent alleles were CSN1S1*B, CSN2*A2, CSN3*A, variant 2 of CSN1S1 promoter, and variant A of Bov-A2 element. A quite balanced frequency was observed for the LGB*A and LGB*B. No CSN2*C, CSN3*C, and CSN3*H alleles were found. The CSN1S1*C, CSN2*A3, CSN2*I alleles were detected only at the heterozygous condition and at a frequency lower than 2%. The method allowed also finding some unusual intragenic haplotype, such as the Bov-A2 element-CSN3 haplotypes A-B and B-E. As to LGB one of the four SNPs tested was always homozygous for the same mutation, as already noticed. This finding confirms that this synonymous SNP is probably a sequencing mistake or a rare mutation not decisive for the LGB typing in the Italian Friesian. Reducing cost and time for typing simultaneously many SNPs, the method will be applied to a greater number of individuals and to other breeds, aiming to find out a number of animals for each haplotype sufficient for accurate statistical analysis to give a better understanding of the significance of milk protein polymorphism
Characterization of the casein gene complex in West Africa goats and description of a new αs1-casein polymorphism
The analysis of casein polymorphisms was carried
out in West Africa goat populations: Red Sokoto (n =
57), West African Dwarf Nigeria (n = 27), West African
Dwarf Cameroon (n = 39), and Borno (n = 37). The 4
casein genes alphas1 (CSN1S1), beta (CSN2), alphas2 (CSN1S2), and kappa (CSN3) were typed at the DNA level. No null alleles were found in any of the genes analyzed. A PCR single-strand conformation polymorphism method was
implemented for the identification of CSN1S1*F allele
simultaneously with A/01, B/E, N and the new allele.
The allele differed from CSN1S1*B by a synonymous
transversion TCG->TCT in the codon corresponding to
Ser66 of the mature protein. The new allele, named
CSN1S1*B', occurred at a high frequency in all the
populations, ranging from 0.295 (West African Dwarf
Cameroon) to 0.405 (Borno). A greater frequency was
found for alleles associated with high alphas1-casein quantity,
as has already been observed in the goat populations
from the Mediterranean area. The intermediate
E allele occurred only in the Red Sokoto and at a low
frequency. The faint F allele occurred in 3 populations
at frequencies lower than 0.03. Linkage disequilibrium
occurred in all the populations, with highly significant
differences in Borno, Red Sokoto, and West Africa
Dwarf Nigeria, and significant differences in West Africa
Dwarf Cameroon. Only 10 haplotypes showed frequencies
>= 0.05 in at least 1 of the 4 populations considered,
and the overall frequency was >0.1 only for 4
haplotypes: BAAB, B'ACA, ACAB, and BACA (in the
order CSN1S1-CSN2-CSN1S2-CSN3). Haplotype
BAAB, postulated as an ancestral haplotype in previous
studies, was the most common haplotype in all breeds
except Borno, where B'ACA was predominant. The results
obtained are of considerable significance given that very little information exists on the subject for African goats. The high frequency of strong alleles in the calcium-sensitive caseins as well as the high linkage disequilibrium found among the casein genes in the African breeds analyzed may suggest that specific casein haplotypes have already been selected due to their advantages for nutrition. Haplotypes providing greater
protein and casein content would increase the energy
content of milk, thus resulting in more favorable growth
and survival of young goats and humans consuming
the milk
Short communication: Carora cattle shows high variability at αsl-casein
The objective of this study was to analyze the genetic variability of milk proteins of the Carora, a shorthorned
Bos taurus cattle breed in Venezuela and in other Southern American countries that is primarily used for milk production. A total of 184 individual milk samples were collected from Carora cattle in 5 herds in Venezuela. The milk protein genes alphas1-casein (CN) (CSN1S1), alphas2-CN (CSN2), beta-CN (CSN3), and beta-lactoglobulin (LGB) were typed at the protein level by isoelectrofocusing. It was necessary to further analyze CSN1S1 at the DNA level by a PCR-based method to distinguish CSN1S1*G from B. Increased variation
was found in particular at the CSN1S1 gene, where 4
variants were identified. The predominant variant was
CSN1S1*B (frequency = 0.8). The second most common
CSN1S1 variant was CSN1S1*G (0.101), followed by CSN1S1*C (0.082). Moreover, a new isoelectrofocusing
pattern was identified, which may result from a novel CSN1S1 variant, named CSN1S1*I, migrating at an intermediate position between CSN1S1*B and CSN1S1*C. Six cows carried the variant at the heterozygous condition. For the other loci, predominance of CSN2*A2 (0.764), CSN3*B (0.609), and LGB*B (0.592) was observed. Haplotype frequencies (AF) at the CSN1S1-CSN2-CSN3 complex were also estimated by
taking association into account. Only 7 haplotypes showed AF values >0.05, accounting for a cumulative frequency of 0.944. The predominant haplotype was B-A2-B (frequency = 0.418), followed by B-A2-A (0.213). The occurrence of the G variant is at a rather high frequency, which is of interest for selection within the Carora breed because of the negative association of this variant with the synthesis of the specific protein. From a cheese-making point of view, this variant is associated with improved milk-clotting parameters but is negatively associated with cheese ripening. Thus, milk protein typing should be routinely carried out in the breed, with particular emphasis on using a DNA test to detect the CSN1S*G variant. The CSN1S*G allele is likely to have descended from the Brown Swiss, which contributed to the Carora breed and also carries this allele
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