A population of Desertifilum (Cyanobacteria, Oscillatoriales) from an oligotrophic desertic biotope was isolated and characterized using a polyphasic approach including molecular, morphological, and ...ecological information. The population was initially assumed to be a new species based on ecological and biogeographic separation from other existing species, however, phylogenetic analyses based on sequences of the 16S rRNA gene and 16S–23S ITS region, placed this strain clearly within the type species, Desertifilum tharense. Comparative analysis of morphology, 16S rRNA gene similarity, 16S–23S ITS secondary structure, and percent dissimilarity of the ITS regions for all characterized strains supports placing the six Desertifilum strains (designated as PD2001/TDC17, UAM‐C/S02, CHAB7200, NapGTcm17, IPPAS B‐1220, and PMC 872.14) into D. tharense. The recognition of Desertifilum salkalinema and Desertifilum dzianense is not supported, although our analysis does support continued recognition of Desertifilum fontinale. Pragmatic criteria for recognition of closely related species are proposed based on this study and others, and more rigorous review of future taxonomic papers is recommended.
A number of heterocytous, mat‐forming, tapering cyanobacteria in Rivulariaceae have recently been observed in both the Atlantic and Pacific coasts in the rocky intertidal and supratidal zones. These ...belong to the genera Nunduva, Kyrtuthrix, and Phyllonema and have been the subject of several recent studies. Herein, two new species of Nunduva (N. komarkovae and N. sanagustinensis) and two new species of Kyrtuthrix (K. munecosensis and K. totonaca) are characterized and described from the coasts of Mexico. Genetic separation based on the 16S‐23S ITS region was pronounced (>10% in all comparisons). Morphological differences between all existing species in these two genera were also observed, but the group is morphologically complex, and these taxa are considered pseudocryptic. Nunduva and Kyrtuthrix remain morphologically and phylogenetically separate even with the addition of new species. However, how long will this remain the case? Many new genera and species of cyanobacteria have recently been described. Will the taxonomy of cyanobacteria eventually become saturated? Will we start to see multiple populations for the same cryptic species, or will future taxonomists collapse multiple species into fewer species, or multiple genera into single genera. The description of even more Nunduva and Kyrtuthrix species causes us to pause and evaluate the future of cyanobacterial taxonomy. These same questions are faced by algal taxonomists studying other phyla, and the resolution may ultimately be similar.
There is insufficient available information on behavioral changes in the absence of cognitive impairment as factors increasing the risk of conversion to dementia.
To observe and analyze patients with ...mild behavioral impairment (MBI), mild cognitive impairment (MCI), and a psychiatry group (PG) to compare the risk of progression to dementia.
From 677 initially assessed ≥60-year-old patients, a series of 348 patients was studied for a five-year period until censoring or conversion to dementia: 96 with MBI, 87 with MCI, and 165 with general psychiatry disorders, including 4 subgroups: Anxiety, Depression, Psychosis and Others. All patients were assessed with clinical, psychiatric, neurological, neuropsychological, and neuroimaging studies.
From 348 patients, 126 evolved to dementia (36.2%). Conversion was significantly higher in MBI (71.5%), followed by the MCI-MBI overlap (59.6%) and MCI (37.8%) groups, compared to PG (13.9%) (Log-rank p < 0.001). MCI patients mostly converted to Alzheimer's dementia, while MBI converted to frontotemporal dementia and Lewy body dementia. Patients in PG converted to Lewy body dementia and frontotemporal dementia.
Conversion to dementia is significantly higher in patients with neuropsychiatric symptoms. The MBI concept generates a new milestone in the refining of diagnosis of neurodegenerative diseases and the possibility of creating neuropsychiatric profiles. Its earlier identification will allow new possibilities for therapeutic intervention.
Chagas disease or American trypanosomiasis is a pathology affecting about 8–11 million people in Mexico, Central America, and South America, more than 300 000 persons in the United States as well as ...an indeterminate number of people in other non-endemic countries such as USA, Spain, Canada and Switzerland. The aetiological agent is Trypanosoma cruzi, a protozoan transmitted by multiple routes; among them, congenital route emerges as one of the most important mechanisms of spreading Chagas disease worldwide even in non-endemic countries and the oral route as the responsible of multiple outbreaks of acute Chagas disease in regions where the vectorial route has been interrupted. The aim of this review is to illustrate the recent research and advances in host-pathogen interaction making a model of how the virulence factors of the parasite would interact with the physiology and immune system components of the placental barrier and gastrointestinal tract in order to establish a response against T. cruzi infection. This review also presents the epidemiological, clinical and diagnostic features of congenital and oral Chagas disease in order to update the reader about the emerging scenarios of Chagas disease transmission.
Two untapered, heterocytous species were observed and collected from the intertidal and supratidal zones of the Mexican coastline of the Pacific Ocean near Oaxaca and from the Gulf of Mexico. These ...populations were highly similar in morphology to the freshwater taxon Petalonema incrustans in the Scytonemataceae. However, 16S rRNA sequence data and phylogenetic analysis indicated that they were sister taxa to the epiphyllic, Brazilian species Phyllonema aveceniicola in the Rivulariaceae, described from culture material. While genetic identity between the two new species was high, they differed significantly in morphology, 16S rRNA gene sequence identity, and sequence and structure of the 16S–23S ITS region. Their morphology differed markedly from the generitype of the previously monotypic Phyllonema, which has tapered, heteropolar, single‐false branched trichomes with very thin or absent sheath. The two new species, Phyllonema ansata and Phyllonema tangolundensis, described from both culture and environmental material, have untapered, isopolar, geminately false branched trichomes with thick, lamellated sheaths, differences so significant that the species would not be placed in Phyllonema without molecular corroboration. The morphological differences are so significant that a formal emendation of the genus is required. These taxa provide a challenge to algal taxonomy because the morphological differences are such that one would logically conclude that they represent different genera, but the phylogenetic evidence for including them all in the same genus is conclusive. This conclusion is counter to the current trend in algal taxonomy in which taxa with minor morphological differences have been repeatedly placed in separate genera based primarily upon DNA sequence evidence.
En este artículo se discute la práctica de la guerra en los grupos sociales antiguos de Costa Rica a través del estudio de artefactos arqueológicos, fuentes etnohistóricas y relatos de tradición oral ...indígena. Primero, se reseñan algunas propuestas sobre el tema realizadas por profesionales en arqueología. Luego, se expone cómo se presenta la guerra tanto en fuentes históricas como en la tradición oral. Finalmente, se interpreta la evidencia arqueológica con base en la estatuaria de las colecciones del Museo Nacional de Costa Rica, el Museo del Jade y de la Cultura Precolombina y el Museo del Oro Precolombino. El estudio resalta la importancia de la figura del guerrero dentro de la estratificación social de las sociedades pasadas, así como el hecho de que la guerra constituía una actividad constante y permanente entre los grupos.
Preventing the adhesion of pathogens to host cells provides an innovative approach to tackling multidrug-resistant bacteria. In this regard, the identification of outer membrane protein A (OmpA) as a ...key bacterial virulence factor has been a major breakthrough. The use of virtual screening helped us to identify a cyclic hexapeptide AOA-2 that inhibits the adhesion of Acinetobacter baumannii, Pseudomonas aeruginosa and Escherichia coli to host cells and the formation of biofilm, thereby preventing the development of infection in vitro and in a murine sepsis peritoneal model. Inhibition of OmpA offers a strategy as monotherapy to address the urgent need for treatments for infections caused by Gram-negative bacilli.
The function of catalases A and T from the budding yeast
Saccharomyces cerevisiae
(
ScCta1
and
ScCtt1
) is to decompose hydrogen peroxide (H
2
O
2
) to mitigate oxidative stress. Catalase orthologs ...are widely found in yeast, suggesting that scavenging H
2
O
2
is crucial to avoid the oxidative damage caused by reactive oxygen species (ROS). However, the function of catalase orthologs has not yet been experimentally characterized in vivo. Here, we heterologously expressed
Debaryomyces hansenii DhCTA1
and
DhCTT1
genes, encoding
ScCta1
and
ScCtt1
orthologs, respectively, in a
S. cerevisiae
acatalasemic strain (
cta1
Δ
ctt1
Δ). We performed a physiological analysis evaluating growth, catalase activity, and H
2
O
2
tolerance of the strains grown with glucose or ethanol as carbon source, as well as under NaCl stress. We found that both genes complement the catalase function in
S. cerevisiae
. Particularly, the strain harboring
DhCTT1
showed improved growth when ethanol was used as carbon source both in the absence or presence of salt stress. This phenotype is attributed to the high catalase activity of
DhCtt1
detected at the exponential growth phase, which prevents intracellular ROS accumulation and confers oxidative stress resistance.
Composting is an alternative for the recovery and recycling of green waste (GW) with the potential to generate a product of high agricultural value. However, composting is affected by the high ...content of slowly degradable lignocellulosic substances that prolong processing time and impact end-product quality. Adding food waste (FW) and bacterial inocula are strategies that can increase the degradation rates of green waste. This study determined the effect of adding a bacterial inocula composed of Bacillus sp. F3×3 and Paenibacillus sp F1A5 and co-substrates on the GW composting processes and end-product quality. Three treatments were evaluated: i) TGW: 100% GW (p/p) without bacterial inocula, ii) TI: 50% GW, 32.5% unprocessed FW (UPFW), 2.5% processed FW (PFW), 13% sawdust (SW) and 2% phosphoric rock (PR) with bacteria inocula during the cooling phase and iii) TNI: mixture 50% GW, 32.5% UPFW, 2.5% PFW, 13% SW and 2% PR without any bacterial inocula. Results showed that bacterial inocula with the co-substrates accelerated the degradation rate of organic matter (TIkG 0.14d−1; TNIkG: 0.1d−1; TGWkG: 0.1d−1), lignocellulose (TI: 31.7%; TNI:23.1%; TGW:15.5%) and increased germination indexes (TI:98.8%; TNI:86.03%; TGW:75.5%). Likewise, the respirometric index (RI) was lowered in TI (3.4 ± 0.1 gCO2 d−1) which indicates a high stability of the end-product. The addition of the bacterial inocula reduced the cooling phase duration by 63% and 20% for TGW and TNI, respectively. The end-product obtained from the TI treatment is considered suitable for use as a soil amendment.
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•Green waste was inoculated with Bacillus sp. and Paenibacillus sp. during composting.•Food waste was added as a co-substrate in the inoculated treatments.•The above amendments reduced cooling phase by 63% and 20% in TGW and TNI.•Both strategies can improve the nutrient content, stability, and maturity of the end-product.
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