•Currently, Populus spp. timber is not included in Spanish visual grading standard.•Qualifying efficiency of UNE-56544:1997 applied in this timber is not appropriate.•ME-1 visual grade does not ...comply to the minimum values established in EN-338.•Supervised Machine Learning algorithms use improves this qualifying process.•Visual defects, sawing systems and non-destructive variables were better predictors than UNE-56544.
The efficiency of visual grading standards applied to structural timber is often inappropriate, and timber properties are either under or over-graded. Although not included in the current UNE 56544 visual grading standard, machine learning algorithms represent a promising alternative to grade structural timber. The general aim of this research was to compare the performance of machine learning algorithms based on visual defects, non-destructive techniques and sawing systems (“cut type”) with UNE 56544:1997 visual grading in order to predict the qualifying efficiency of Populus x euramericana I-214 structural timber. Visual evaluation, ultrasound and vibrational non-destructive testing, and sawing systems register (radial, tangential and mixed) were applied to characterize 945 beams. In addition, in order to retrieve actual physical-mechanical values, density and static bending destructive testing (EN-408:2011 + A1:2012) was also carried out. Several machine learning algorithms were then used to grade the beams, and their predictive accuracy was compared with that of visual grading. To do so, three scenarios were considered: a first scenario in which only visual variables were used; a second scenario in which “cut type” variables were also included; and a third scenario in which additional non-destructive variables were considered. Results showed a poor level of performance of UNE 56544:1997, with an apparent mismatch between the strength values assigned for each visual grade (established by the EN 338 standard) and the actual values. On the opposite, all algorithms performed better than visual grading and may thus be deemed as promising timber strength grading tools.
In aquatic systems, some substances considered as endocrine disruptors have been detected, which can be due to their incomplete elimination in wastewater treatment plants (WWTPs) and inadequate ...disposal of pharmaceuticals. Among these contaminants are 17α-ethinylestradiol (EE2) and caffeine (CAF). Moreover, it has been reported that this kind of contaminants may provoke different adverse effects in many aquatic organisms. Because of that, in the present study, up-flow anaerobic sludge blanket reactors (UASB) coupled with the Fenton process was evaluated for EE2 and CAF removal spiked in wastewater samples. First, the best reaction conditions were established in each process. For UASB reactor, two hydraulic retention times (HRT 8 and 24 h) were evaluated, achieving the highest chemical organic demand (COD) removal (70 %) and drug elimination (84 %-86 %) with HRT 24 h. Subsequently, Fenton process was conducted at pH 3 with different levels of Fe
2+
(0.05-0.5 mmol/L) and molar ratios Fe
2+
:H
2
O
2
(1:1-1:10). Better results were obtained with 0.5 mmol Fe
2+
/L, and 1:10 ratio molar Fe
2+
:H
2
O
2
. Finally, UASB-Fenton coupled system allowed 80 % of COD decrease, almost complete removal of drugs and the toxicity of samples on Vibrio fischeri was reduced from 73 % to 30 %, demonstrating that this coupled system is a promising and efficient system for pharmaceutical compounds removal from wastewater.
Rattlesnake venoms may be classified according to the presence/absence and relative abundance of the neurotoxic phospholipases A 2 s (PLA 2 s), such as Mojave toxin, and snake venom ...metalloproteinases (SVMPs). In Mexico, studies to determine venom variation in Mojave Rattlesnakes (
) are limited and little is known about the biological and proteolytic activities in this species. Tissue (34) and venom (29) samples were obtained from
from different locations within their distribution in Mexico. Mojave toxin detection was carried out at the genomic (by PCR) and protein (by ELISA) levels for all tissue and venom samples. Biological activity was tested on representative venoms by measuring LD 50 and hemorrhagic activity. To determine the approximate amount of SVMPs, 15 venoms were separated by RP-HPLC and variation in protein profile and proteolytic activity was evaluated by SDS-PAGE (
= 28) and Hide Powder Azure proteolytic analysis (
= 27). Three types of venom were identified in Mexico which is comparable to the intraspecific venom diversity observed in the Sonoran Desert of Arizona, USA: Venom Type A (∼Type II), with Mojave toxin, highly toxic, lacking hemorrhagic activity, and with scarce proteolytic activity; Type B (∼Type I), without Mojave toxin, less toxic than Type A, highly hemorrhagic and proteolytic; and Type A + B, containing Mojave toxin, as toxic as venom Type A, variable in hemorrhagic activity and with intermediate proteolytic activity. We also detected a positive correlation between SVMP abundance and hemorrhagic and proteolytic activities. Although more sampling is necessary, our results suggest that venoms containing Mojave toxin and venom lacking this toxin are distributed in the northwest and southeast portions of the distribution in Mexico, respectively, while an intergradation in the middle of both zones is present.
Tuberculosis continues to be an important public health problem. Particularly considering Beijing-family strains of Mycobacterium tuberculosis, which have been associated with drug-resistance and ...hypervirulence. The Beijing-like SIT190 (BL) is the most prevalent Beijing strain in Colombia. The pathogenic mechanism and immune response against this pathogen is unknown. Thus, we compared the course of pulmonary TB in BALB/c mice infected with Classical-Beijing strain 391 and BL strain 323. The disease course was different among infected animals with Classical-Beijing and BL strain. Mice infected with BL had a 100% mortality at 45 days post-infection (dpi), with high bacillary loads and massive pneumonia, whereas infected animals with Classical-Beijing survived until 60 dpi and showed extensive pneumonia and necrosis. Lung RNA extraction was carried out at early (day 3 dpi), intermediate (day 14 dpi), and late (days 28 and 60 dpi) time points of infection. Transcriptional analysis of infected mice with Classical-Beijing showed several over-expressed genes, associated with a pro-inflammatory profile, including those for coding for CCL3 and CCL4 chemokines, both biomarkers of disease severity. Conversely, mice infected with BL displayed a profile which included the over-expression of several genes associated with immune-suppression, including Nkiras, Dleu2, and Sphk2, highlighting an anti-inflammatory milieu which would allow high bacterial replication followed by an intense inflammatory response. In summary, both Beijing strains induced a non-protective immune response which induced extensive tissue damage, BL strain induced rapidly extensive pneumonia and death, whereas Classical-Beijing strain produced slower extensive pneumonia later associated with extensive necrosis.
Abbreviations
Mtb: Mycobacterium tuberculosis; SIT: Spoligotype International Type; TB: Tuberculosis; CTB: Classical-typical Beijing; BL: Beijing-Like; CCL3: Chemokine (C-C motif) ligand 3 (CCL3); CCL4: Chemokine (C-C motif) ligand four (CCL4); WHO: World health Organization; DR: Direct Repeats; IFN-γ: Interferon Gamma; IL: Interleukin; TGF-β: Transforming Growth Factor Beta; XDR: Extremely Drug Resistant; MDR: Multi Drug Resistant; MIRU-VNTR: Mycobacterial Interspersed Repetitive Units-Variable Number Tandem repeats; OADC: Oleic Albumin Dextrose Catalase; ATCC: American Type Culture Collection; MOI: Multiplicity of Infection; CFUs: Colony Forming Units; ELISA: enzyme-linked immunosorbent assay; qRT-PCR: Real-Time Quantitative Reverse Transcription PCR; RNA-seq: Ribonucleic Acid sequencing; RIN: RNA Integrity Number; RNA: Ribonucleic Acid; DNA: Deoxyribonucleic Acid; dsDNA HS: Double stranded Deoxyribonucleic Acid High Sensitivity; RAI: Red de Apoyo à la Investigacion, Mexico City, Mexico; DEG: Differential Expressed Genes; GO: Gene Ontology; KEGG: Kyoto Encyclopedia of Genes and Genomes; ORA: Over-Representation Analysis; SNPs: Single Nucleotide Polymorphisms; TNFα: Tumoral necrosis factor alpha; DE: Differential Expression; EPA: Enrichment Pathways Analysis; TLR: Toll-Like receptor; NLRP: NOD-like receptor with Pyrin domain; tRNA: Transfer RNA; MAPK: Mitogen-Activated Protein Kinase; NK: Natural killer; ATP: Adenosine Triphosphate; DGC: dystrophin-glycoprotein complex; PDIM: Ptiocerol Dimicocerosate; NCBI: National Center for Bioinformatics Information
The circulatory system is the main mechanism for transmission of the Hepatitis C Virus (HCV). A new class of HCV infections, Occult HCV infection (OCI), is defined as the presence of HCV-RNA in ...hepatocytes with the absence of HCV in the serum/plasma utilizing current laboratory assays. Different groups have reported the prevalence of OCI; however, its associated risk factors have not been established. In Mexico, there are no reports about OCI, so the objective of our study was to determine the prevalence of OCI in total blood donors in Mexico City, as well as its associated risk factors.
Blood donors that were considered eligible for donation, according to NOM 253-SSA1-2012, were randomly selected. Demographic data was collected from 1,037 donors. Plasma and peripheral blood mononuclear cells were assessed for HCV-RNA. The presence of HCV-RNA was determined by nested PCR for the 5'-UTR region. Logistic regression was used to calculate the odds ratio (OR) and 95% confidence interval (95%CI) to determine the level of association.
The prevalence of OCI was 3.4% among blood donors. Homosexual relationships (OR = 5.52, 95%CI: 1.53-19.92, p<0.05) and acupuncture (OR = 3.56, 95%CI: 1.41-8.98, p<0.05) were significantly associated with OCI.
There is a significant presence of OCI in the blood donor population in Mexico City. The main risk factors for OCI transmission are homosexual relationships and acupuncture. This study supports the increased use of sensitive and specific screening tests for blood bank testing.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
To corroborate the ontogenetic shift in the venom composition of the Mexican Black-tailed Rattlesnake (Crotalus molossus nigrescens) previously reported through the census approach, we evaluated the ...shift in the protein profile, lethality, and proteolytic and phospholipase activities of four venom samples obtained in 2015, 2018, 2019, and 2021 from one C. m. nigrescens individual (CMN06) collected in Durango, Mexico. We demonstrated that the venom of C. m. nigrescens changed from a myotoxin-rich venom to a phospholipase A2 and snake venom metalloproteinase-rich venom. Additionally, the proteolytic and phospholipase activities increased with age, but the lethality decreased approximately three times.
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•The ontogenetic venom shift in C. m. nigrescens is reported using a single animal.•Venom composition transitioned from myotoxin-rich to rich in PLA2s and SVMPs.•Ontogenetic venom shift predicts proteolytic, phospholipase, and toxic activities.
The genus Guaiacum belongs to the family Zigophyllaceae, encompassing six species of evergreen trees and shrubs. The geographical distribution model allows designing and creating probabilistic maps ...of sites where species are distributed. The Maxent program projects patterns of geographic distributions by using ecological niche models. In Mexico, several studies indicate that the distribution of G. coulteri covers 11 Protected Natural Areas (ANP, for their name in Spanish) covering 2,777km2; of this area, 75% corresponds to the states of Oaxaca, Sonora and Sinaloa, data which matches that of the present study. The result of ecological niche modeling for G. coulteri has a coverage of 24,908.238 km2 and the surface of the ANPs is 13,545.76 km2; when overlaying them, the niche area within these is 1,104.42 km2, which corresponds to a coverage of 9.21%. The results suggest that modeling of the potential G. coulteri niche matches the current distribution of the species; although there are areas of modeling that are not found within the ANP, the resulting modeling can be used as a basis for proposing specific fieldwork sites.
The genus Guaiacum belongs to the family Zigophyllaceae, encompassing six species of evergreen trees and shrubs. The geographical distribution model allows designing and creating probabilistic maps ...of sites where species are distributed. The Maxent program projects patterns of geographic distributions by using ecological niche models. In Mexico, several studies indicate that the distribution of G. coulteri covers 11 Protected Natural Areas (ANP, for their name in Spanish) covering 2,777km.sup.2; of this area, 75% corresponds to the states of Oaxaca, Sonora and Sinaloa, data which matches that of the present study. The result of ecological niche modeling for G. coulteri has a coverage of 24,908.238 km.sup.2 and the surface of the ANPs is 13,545.76 km.sup.2; when overlaying them, the niche area within these is 1,104.42 km.sup.2, which corresponds to a coverage of 9.21%. The results suggest that modeling of the potential G. coulteri niche matches the current distribution of the species; although there are areas of modeling that are not found within the ANP, the resulting modeling can be used as a basis for proposing specific fieldwork sites.
We studied HLA class I (HLA-A, -B) and class II (HLA-DRB1, -DQB1) allele groups and alleles by PCR-SSP based typing in a total of 15,318 mixed ancestry Mexicans from all the states of the country ...divided into 78 sample sets, providing information regarding allelic and haplotypic frequencies and their linkage disequilibrium, as well as admixture estimates and genetic substructure. We identified the presence of 4268 unique HLA extended haplotypes across Mexico and find that the ten most frequent (HF > 1%) HLA haplotypes with significant linkage disequilibrium (Δ’≥0.1) in Mexico (accounting for 20% of the haplotypic diversity of the country) are of primarily Native American ancestry (A*02~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*08~DQB1*04, A*68~B*39~DRB1*04~DQB1*03:02, A*02~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*14~DQB1*03:01, A*24~B*35~DRB1*04~DQB1*03:02, A*24~B*39~DRB1*04~DQB1*03:02, A*02~B*40:02~DRB1*04~DQB1*03:02, A*68~B*35~DRB1*04~DQB1*03:02, A*02~B*15:01~DRB1*04~DQB1*03:02). Admixture estimates obtained by a maximum likelihood method using HLA-A/-B/-DRB1 as genetic estimators revealed that the main genetic components in Mexico as a whole are Native American (ranging from 37.8% in the northern part of the country to 81.5% in the southeastern region) and European (ranging from 11.5% in the southeast to 62.6% in northern Mexico). African admixture ranged from 0.0 to 12.7% not following any specific pattern. We were able to detect three major immunogenetic clusters correlating with genetic diversity and differential admixture within Mexico: North, Central and Southeast, which is in accordance with previous reports using genome-wide data. Our findings provide insights into the population immunogenetic substructure of the whole country and add to the knowledge of mixed ancestry Latin American population genetics, important for disease association studies, detection of demographic signatures on population variation and improved allocation of public health resources.
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