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1.
PLoS One ; 18(9): e0291130, 2023.
Article in English | MEDLINE | ID: mdl-37713398

ABSTRACT

We introduce a general framework for empirically detecting interactions in communities of entities characterized by different features. This approach is inspired by ideas and methods coming from ecology and finance and is applied to a large dataset extracted from the cryptocurrency market. The inter-species interaction network is constructed using a similarity measure based on the log-growth rate of the capitalizations of the cryptocurrency market. The detected relevant interactions are only of the cooperative type, and the network presents a well-defined clustered structure, with two practically disjointed communities. The first one is made up of highly capitalized cryptocurrencies that are tightly connected, and the second one is made up of small-cap cryptocurrencies that are loosely linked. This approach based on the log-growth rate, instead of the conventional price returns, seems to enhance the discriminative potential of the network representation, highlighting a modular structure with compact communities and a rich hierarchy that can be ascribed to different functional groups. In fact, inside the community of the more capitalized coins, we can distinguish between clusters composed of some of the more popular first-generation cryptocurrencies, and clusters made up of second-generation cryptocurrencies. Alternatively, we construct the network of directed interactions by using the partial correlations of the log-growth rate. This network displays the important centrality of Bitcoin, discloses a core cluster containing a branch with the most capitalized first-generation cryptocurrencies, and emphasizes interesting correspondences between the detected direct pair interactions and specific features of the related currencies. As risk strongly depends on the interaction structure of the cryptocurrency system, these results can be useful for assisting in hedging risks. The inferred network topology suggests fewer probable widespread contagions. Moreover, as the riskier coins do not strongly interact with the others, it is more difficult that they can drive the market to more fragile states.


Subject(s)
Ecology , Probability
2.
Nutr Cancer ; 69(8): 1272-1280, 2017.
Article in English | MEDLINE | ID: mdl-29068700

ABSTRACT

Obesity is associated with non-alcoholic steatohepatitis (NASH) and hepatocellular carcinoma (HCC). Obesity and metabolic abnormalities resulting in low-grade inflammation can increase the risk of developing NASH and HCC. NASH, a risk factor for HCC, is characterized by increased inflammation, lipid accumulation, and liver injury. Obesogenic proteins modulate signaling pathways that induce physiological changes including lipogenesis, ROS, and inflammation. Silibinin, a polyphenol in milk thistle seed, has been shown to have anti-inflammatory properties. Studies have yet to determine whether silibinin can be used to dissect the obesity-cancer link to delay progression of liver cancer. Using an in vitro model, sera from obese (OB), overweight (OW), or normal weight (NW) males (based on BMI) were used to determine the efficacy of silibinin to reduce the pro-tumorigenic properties of obesity. HepG2 cells were exposed to OB, OW, NW ± silibinin and tested for growth, ROS, lipogenesis, MMP-9, invasion and protein expression. Silibinin suppressed obesity-induced growth, ROS, lipogenesis, MMP-9, and cell invasion. These physiological changes corresponded with decreased FASN, IL-6, IL-1B, and phosphorylated Erk. We describe the differential effect of sera from OB, OW, and NW males on characteristics relevant for liver cancer and the potential use of silibinin to mitigate these effects.


Subject(s)
Liver Neoplasms/drug therapy , Obesity/drug therapy , Silymarin/pharmacology , Body Mass Index , Carcinoma, Hepatocellular/complications , Carcinoma, Hepatocellular/drug therapy , Cell Proliferation/drug effects , Fatty Acid Synthase, Type I/genetics , Fatty Acid Synthase, Type I/metabolism , Hep G2 Cells , Humans , Inflammation , Interleukin-1beta/genetics , Interleukin-1beta/metabolism , Interleukin-6/genetics , Interleukin-6/metabolism , Lipogenesis/drug effects , Liver Neoplasms/complications , Male , Matrix Metalloproteinase 9/genetics , Matrix Metalloproteinase 9/metabolism , Obesity/complications , Overweight/complications , Overweight/drug therapy , Reactive Oxygen Species/metabolism , Risk Factors , Silybin
3.
Neotrop Entomol ; 45(4): 341-50, 2016 Aug.
Article in English | MEDLINE | ID: mdl-26911160

ABSTRACT

Coleoptera is the largest and diverse group of organisms, but few studies are dedicated to determine the diversity and feeding guilds of saproxylic Coleoptera. We demonstrate the diversity, abundance, feeding guilds, and succession process of Coleoptera associated with decaying wood in a tropical deciduous forest in the Mixteca Poblana, Mexico. Decaying wood was sampled and classified into four stages of decay, and the associated Coleoptera. The wood was identified according to their anatomy. Diversity was estimated using the Simpson index, while abundance was estimated using a Kruskal-Wallis test; the association of Coleoptera with wood species and decay was assessed using canonical correspondence analysis. Decay wood stage I is the most abundant (51%), followed by stage III (21%). We collected 93 Coleoptera belonging to 14 families, 41 genera, and 44 species. The family Cerambycidae was the most abundant, with 29% of individuals, followed by Tenebrionidae with 27% and Carabidae with 13%. We recognized six feeding guilds. The greatest diversity of Coleoptera was recorded in decaying Acacia farnesiana and Bursera linanoe. Kruskal-Wallis analysis indicated that the abundance of Coleoptera varied according to the species and stage of decay of the wood. The canonical analysis showed that the species and stage of decay of wood determined the composition and community structure of Coleoptera.


Subject(s)
Coleoptera , Wood , Animals , Forests , Mexico , Population Dynamics
4.
Matern Child Health J ; 17(3): 539-44, 2013 Apr.
Article in English | MEDLINE | ID: mdl-22535218

ABSTRACT

To evaluate the relationship between changes in fecundity rates and maternal age and the impact of maternal age on low birth weight (LBW) rates in a developed region in southern Brazil. A time series study evaluating birth weight and maternal ages through the born alive information system (SINASC) in Porto Alegre from 1996 to 2008. The Chi-square test for trends was used to evaluate the trend of LBW and fecundity rates at each maternal age. Population attributed risk (PAR) was used to calculate the impact of maternal age on LBW rates. The study included 271,100 newborns. There was a significant reduction in fecundity rates in all age groups younger than 34 years, but especially in the groups between 20 and 29 years. Overall LBW increased from 9.3 to 10.7 % (P < 0.001). The PAR for LBW showed a reduction in the group from 17 to 19 years (from 1.7 % in 1996-1999 to 0.1 % in 2004-2008), and an increase in the groups from 35 to 39 years (from 2.0 % in 1996-1999 to 2.3 % in 2004-2008) and above 40 (from 1.1 % in 1996-1999 to 1.5 % in 2004-2008). There was a significant change in fecundity pattern in the last 12 years in southern Brazil. Adolescent mothers were surpassed by mothers over 30 years of age in terms of vulnerability for LBW babies. The results show a change in the maternal age distribution towards older mothers, accompanied by an increasing incidence of LBW. This demographic transition also involved a paradoxical pattern with a remarkable reduction in fecundity rates in intermediate maternal age groups with concomitant increase in their risk for LBW.


Subject(s)
Birth Rate/trends , Infant, Low Birth Weight , Live Birth/epidemiology , Population Dynamics/statistics & numerical data , Adolescent , Adult , Age Distribution , Brazil/epidemiology , Female , Fertility , Humans , Infant, Newborn , Male , Maternal Age , Mothers/statistics & numerical data , Population Dynamics/trends , Population Surveillance , Pregnancy , Pregnancy Rate , Risk Factors , Socioeconomic Factors , Young Adult
6.
Pediatr Pathol ; 10(6): 993-9, 1990.
Article in English | MEDLINE | ID: mdl-2082343

ABSTRACT

An 8-year-old girl with a long history of cardiac disease had restrictive filling of both ventricles, severe atrioventricular valve regurgitation, and extreme dilation of both atria. At necropsy the inflow areas of both ventricles were small, and part of the left ventricle lacked compact myocardium. Histology revealed myofiber hypertrophy and focal dysplasia (disarray) in both ventricles. The findings suggest an abnormality of cardiac development that occurred before gestation week 5.


Subject(s)
Heart Defects, Congenital/pathology , Child , Female , Heart Defects, Congenital/diagnosis , Heart Defects, Congenital/embryology , Heart Ventricles/abnormalities , Heart Ventricles/embryology , Humans , Myocardium/pathology
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