Hasil untuk "Biology (General)"

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DOAJ Open Access 2025
Variation in Anthyllis vulneraria L. populations in adjacent regions across acidic and basic soils in Val Piora

Ermelinda Gjeta, Diellëza Lajçi, Avni Hajdari et al.

Populations of Anthyllis vulneraria ssp. vulneraria and A. vulneraria ssp. vallesiaca are found in close vicinity in Val Piora, where the geological situation changes abruptly between basic and acidic substrates. At three sites with populations of A. vulneraria s. lato, one in basic soil, one in acidic soil, and one in a mixed area, three samples of a total of sixty plants were collected, and flower morphology and physiological activity was determined. Of each population, the number of plants using Braun-Blanquet squares was determined. The frequency and indication values showed that the two subspecies are adapted to different pH values. A. v. ssp. vallesiaca and A. v. ssp. vulneraria are clearly well separated by the red striped keel, the flag dimension, and flower size. In areas where the two species overlap, introgression occurs. The hybrid population consisted of yellow hybrid plants with red keel, yellow plants, and white plants with a red keel. The hybrids are present at a pH value between the ones of the two subspecies. The rapid increase in chlorophyll fluorescence also clearly showed that the two subspecies differed in their kinetics. The values of the hybrid plants (yellow with red keel) were between those of the populations of the two subspecies.

Biology (General)
DOAJ Open Access 2025
The influence of a conservation‐based grazing program on greater sage‐grouse habitat selection

Jennifer E. Helm, Elizabeth G. Simpson, Lorelle I. Berkeley et al.

Abstract Understanding how vegetation management affects animals' habitat selection patterns is critical for comprehensive conservation planning. As part of a decade‐long study (2011–2019) of 486 adult female sage‐grouse in central Montana, we investigated how a conservation‐based grazing program (CGP) affected greater sage‐grouse (Centrocercus urophasianus) habitat selection at two temporal scales: (a) the seasonal scale (four biologically relevant seasons) and (b) the annual scale. We used resource selection functions to assess sage‐grouse selection for pastures enrolled in a CGP as well as plant functional type and topography. We found that sage‐grouse strongly selected shrub cover, flatter slopes, and less tree cover. They selected CGP‐enrolled pastures (Pre‐, During‐, and Post‐grazing system implementation) over Non‐CGP pastures during all seasons except the summer–fall. During the summer–fall, they selected pastures where CGP implementation was complete. Future research is needed to determine whether selection for CGP‐enrolled pastures was due to unmeasured, underlying differences between CGP and non‐CGP pastures or CGP enrollment patterns rather than effects of different grazing systems, as well as whether these habitat selection differences are linked to demographic rates or population dynamics.

Ecology, General. Including nature conservation, geographical distribution
DOAJ Open Access 2024
Climate factors dominate the elevational variation in grassland plant resource utilization strategies

Jinkun Ye, Yuhui Ji, Jinfeng Wang et al.

Specific leaf area (SLA) and leaf dry matter content (LDMC) are key leaf functional traits often used to reflect plant resource utilization strategies and predict plant responses to environmental changes. In general, grassland plants at different elevations exhibit varying survival strategies. However, it remains unclear how grassland plants adapt to changes in elevation and their driving factors. To address this issue, we utilized SLA and LDMC data of grassland plants from 223 study sites at different elevations in China, along with climate and soil data, to investigate variations in resource utilization strategies of grassland plants along different elevational gradients and their dominant influencing factors employing linear mixed-effects models, variance partitioning method, piecewise Structural Equation Modeling, etc. The results show that with increasing elevation, SLA significantly decreases, and LDMC significantly increases (P < 0.001). This indicates different resource utilization strategies of grassland plants across elevation gradients, transitioning from a “faster investment-return” at lower elevations to a “slower investment-return” at higher elevations. Across different elevation gradients, climatic factors are the main factors affecting grassland plant resource utilization strategies, with soil nutrient factors also playing a non-negligible coordinating role. Among these, mean annual precipitation and hottest month mean temperature are key climatic factors influencing SLA of grassland plants, explaining 28.94% and 23.88% of SLA variation, respectively. The key factors affecting LDMC of grassland plants are mainly hottest month mean temperature and soil phosphorus content, with relative importance of 24.24% and 20.27%, respectively. Additionally, the direct effect of elevation on grassland plant resource utilization strategies is greater than its indirect effect (through influencing climatic and soil nutrient factors). These findings emphasize the substantive impact of elevation on grassland plant resource utilization strategies and have important ecological value for grassland management and protection under global change.

DOAJ Open Access 2024
Prenatal dexamethasone exposure reduces osteoprogenitor proliferation in mice via histone modifications at the Mkp-1 gene locus

Yongheng Xie, Jianwen Su, Mankai Yang et al.

Abstract Prenatal dexamethasone exposure (PDE) has long-term consequences in bone development, though the underlying mechanisms remain unclear. Our results show that PDE offspring exhibit reduced bone mass, fewer osteoblasts and diminished osteoprogenitors proliferation. Further analyses show that PDE increases MKP-1 expression, while decreasing H3 lysine 9 dimethylation (H3K9me2) and H3 lysine 27 trimethylation (H3K27me3) at the Mkp-1 gene locus. Mechanistically, dexamethasone suppresses osteoprogenitors proliferation by upregulating MKP-1 expression, notably through the inhibition of H3K9me2 and H3K27me3 modifications, which promote demethylation and transcriptional activation of the Mkp-1 gene. Importantly, restoring histone methylation balance with PFI-90 or GSK-J4 treatment blocks the inhibitory effects of PDE on MAPK signaling in osteoprogenitors, and mitigates the detrimental impact of PDE on osteoprogenitor proliferation and bone development in the offspring. This study provides new insights into the epigenetic mechanism by which PDE disrupts long-term programming of fetal osteoprogenitor proliferation, ultimately impairing long bone growth in offspring.

Biology (General)
DOAJ Open Access 2023
Dipeptidyl-Aminopeptidases 8 and 9 Regulate Autophagy and Tamoxifen Response in Breast Cancer Cells

Aaron Bettecken, Lisa Heß, Lena Hölzen et al.

The cytosolic dipeptidyl-aminopeptidases 8 (DPP8) and 9 (DPP9) belong to the DPPIV serine proteases with the unique characteristic of cleaving off a dipeptide post-proline from the <i>N</i>-termini of substrates. To study the role of DPP8 and DPP9 in breast cancer, MCF-7 cells (luminal A-type breast cancer) and MDA.MB-231 cells (basal-like breast cancer) were used. The inhibition of DPP8/9 by 1G244 increased the number of lysosomes in both cell lines. This phenotype was more pronounced in MCF-7 cells, in which we observed a separation of autophagosomes and lysosomes in the cytosol upon DPP8/9 inhibition. Likewise, the shRNA-mediated knockdown of either DPP8 or DPP9 induced autophagy and increased lysosomes. DPP8/9 inhibition as well as the knockdown of the DPPs reduced the cell survival and proliferation of MCF-7 cells. Additional treatment of MCF-7 cells with tamoxifen, a selective estrogen receptor modulator (SERM) used to treat patients with luminal breast tumors, further decreased survival and proliferation, as well as increased cell death. In summary, both DPP8 and DPP9 activities confine macroautophagy in breast cancer cells. Thus, their inhibition or knockdown reduces cell viability and sensitizes luminal breast cancer cells to tamoxifen treatment.

DOAJ Open Access 2023
Maturation and harvest time of Ateleia glazioveana Baill. seeds

G. A. Carvalho, P. A. M. Lima, M. A. Carvalho et al.

Abstract Ateleia glazioveana Baill. is a pioneer, rustic and can be used for forest recovery. This work aimed to study the process of physiological maturation of this species. The research was carried out in the city of Alegre - ES, the trees were identified in the floral anthesis and accompanied during the filling of the fruits and development of the seeds until the complete maturation. The fruits were harvested at the following stages 7, 14, 21, 28, 35 and 42 days after anthesis, and characterized according to: morphometry, moisture, fresh and dry mass of fruits and seeds, germination, germination speed index, shoot and root length and dry mass of seedlings. The regression equations were adjusted for the main characteristics analyzed as a function of the harvest period. The point of physiological maturity of timbó occurred at 42 days after anthesis.

Science, Biology (General)
S2 Open Access 2010
Fleas and flea-borne diseases.

I. Bitam, K. Dittmar, P. Parola et al.

Flea-borne infections are emerging or re-emerging throughout the world, and their incidence is on the rise. Furthermore, their distribution and that of their vectors is shifting and expanding. This publication reviews general flea biology and the distribution of the flea-borne diseases of public health importance throughout the world, their principal flea vectors, and the extent of their public health burden. Such an overall review is necessary to understand the importance of this group of infections and the resources that must be allocated to their control by public health authorities to ensure their timely diagnosis and treatment.

403 sitasi en Medicine, Biology
DOAJ Open Access 2022
Screening of mcr-1 among Gram-Negative Bacteria from Different Clinical Samples from ICU Patients in Alexandria, Egypt: One-Year Study

Elbaradei Amira, Sayedahmed Mahrous S., El-Sawaf Gamal et al.

Antimicrobial resistance represents a global dilemma. Our present study aimed to investigate the presence of mcr-1 among different Gram-negative bacteria including Enterobacteriaceae (except intrinsically resistant to colistin) and Pseudomonas aeruginosa. Gram-negative bacterial isolates were collected from different ICUs in several Alexandria hospitals from June 2019 to June 2020. The identification of these Gram-negative isolates was made using the VITEK-2® system (BioMérieux, France). SYBR Green-based PCR was used to screen for the presence of mcr-1 using a positive control that we amplified and sequenced earlier in our pilot study. All isolates were screened for the presence of mcr-1 regardless of their colistin susceptibility. Isolates that harbored mcr-1 were tested for colistin susceptibility and for the presence of some beta-lactamase genes. Klebsiella pneumoniae isolates harboring mcr-1 were capsule typed using the wzi sequence analysis. Four hundred eighty isolates were included in this study. Only six isolates harbored mcr-1.1. Of these, four were resistant to colistin, while two (K. pneumoniae and P. aeruginosa) were susceptible to colistin. Five of the six isolates were resistant to carbapenems. They harbored blaOXA-48, and three of them co-harbored blaNDM-1. K-58 was the most often found among our K. pneumoniae harboring mcr-1.1. To our knowledge, this is the first time to report colistin susceptible P. aeruginosa and K. pneumoniae harboring the mcr-1.1 gene in Egypt. Further studies are needed to investigate the presence of the mcr genes among colistin susceptible isolates to shed more light on its significance as a potential threat.

Genetics, Microbiology
DOAJ Open Access 2022
Effects of Luteolin on Human Breast Cancer Using Gene Expression Array: Inferring Novel Genes

Shih-Ho Wang, Chin-Hu Wu, Chin-Chuan Tsai et al.

<i>Taraxacum officinale</i> (dandelion) is often used in traditional Chinese medicine for the treatment of cancer; however, the downstream regulatory genes and signaling pathways mediating its effects on breast cancer remain unclear. The present study aimed to explore the effects of luteolin, the main biologically active compound of <i>T. officinale</i>, on gene expression profiles in MDA-MB-231 and MCF-7 breast cancer cells. The results revealed that luteolin effectively inhibited the proliferation and motility of the MDA-MB-231 and MCF-7 cells. The mRNA expression profiles were determined using gene expression array analysis and analyzed using a bioinformatics approach. A total of 41 differentially expressed genes (DEGs) were found in the luteolin-treated MDA-MB-231 and MCF-7 cells. A Gene Ontology analysis revealed that the DEGs, including AP2B1, APP, GPNMB and DLST, mainly functioned as oncogenes. The human protein atlas database also found that AP2B1, APP, GPNMB and DLST were highly expressed in breast cancer and that AP2B1 (cut-off value, 75%) was significantly associated with survival rate (<i>p</i> = 0.044). In addition, a Kyoto Encyclopedia of Genes and Genomes pathway analysis revealed that the DEGs were involved in T-cell leukemia virus 1 infection and differentiation. On the whole, the findings of the present study provide a scientific basis that may be used to evaluate the potential benefits of luteolin in human breast cancer. Further studies are required, however, to fully elucidate the role of the related molecular pathways.

Biology (General)
DOAJ Open Access 2022
Distribution, source and ecological risk assessment of polycyclic aromatic hydrocarbons in groundwater in a coal mining area, China

Chunlu Jiang, Dashuang Zhao, Xing Chen et al.

The impact of exposure to polycyclic aromatic hydrocarbons (PAHs) on the ecological environment has aroused widespread concern in coal mining areas. Coal mining and solid waste accumulation are among the main reasons for the widespread occurrence of PAHs in groundwater in mining areas. In this study, the PAH content in groundwater in a coal mining area in northern Anhui, China, was determined via gas chromatography–mass spectrometry (GC–MS). The seasonal variation, composition, spatial distribution and sources of PAHs were analyzed, and their potential ecological risks were evaluated. The concentration of ∑PAHs in groundwater ranged from 15.04 to 449.13 ng/L, mainly including 2- and 3-ring PAHs. There were obvious differences in the PAH distribution in groundwater, and higher PAH concentrations were detected in groundwater near industrial parks and solid waste dumping areas. Diagnostic ratio analysis indicated that the PAHs mainly originate from the combustion of coal, biomass and petroleum. The positive matrix factorization (PMF) results revealed that coal and biomass combustion, traffic emissions, coking emissions and oil leakage contributed 46.59%, 20.06%, 18.70% and 14.65%, respectively, to the detected PAHs. The ecological risk assessment results indicated that this area experienced a moderate ecological risk, and the mean ecological risk values during the wet season were lower than those during the dry season.

DOAJ Open Access 2022
Profiling metabolites and lipoproteins in COMETA, an Italian cohort of COVID-19 patients.

Veronica Ghini, Gaia Meoni, Lorenzo Pelagatti et al.

Metabolomics and lipidomics have been used in several studies to define the biochemical alterations induced by COVID-19 in comparison with healthy controls. Those studies highlighted the presence of a strong signature, attributable to both metabolites and lipoproteins/lipids. Here, 1H NMR spectra were acquired on EDTA-plasma from three groups of subjects: i) hospitalized COVID-19 positive patients (≤21 days from the first positive nasopharyngeal swab); ii) hospitalized COVID-19 positive patients (>21 days from the first positive nasopharyngeal swab); iii) subjects after 2-6 months from SARS-CoV-2 eradication. A Random Forest model built using the EDTA-plasma spectra of COVID-19 patients ≤21 days and Post COVID-19 subjects, provided a high discrimination accuracy (93.6%), indicating both the presence of a strong fingerprint of the acute infection and the substantial metabolic healing of Post COVID-19 subjects. The differences originate from significant alterations in the concentrations of 16 metabolites and 74 lipoprotein components. The model was then used to predict the spectra of COVID-19>21 days subjects. In this group, the metabolite levels are closer to those of the Post COVID-19 subjects than to those of the COVID-19≤21 days; the opposite occurs for the lipoproteins. Within the acute phase patients, characteristic trends in metabolite levels are observed as a function of the disease severity. The metabolites found altered in COVID-19≤21 days patients with respect to Post COVID-19 individuals overlap with acute infection biomarkers identified previously in comparison with healthy subjects. Along the trajectory towards healing, the metabolome reverts back to the "healthy" state faster than the lipoproteome.

Immunologic diseases. Allergy, Biology (General)
DOAJ Open Access 2021
Detection of Pitt–Hopkins Syndrome Based on Morphological Facial Features

Elena D’Amato, Constantino Carlos Reyes-Aldasoro, Arianna Consiglio et al.

This work describes a non-invasive, automated software framework to discriminate between individuals with a genetic disorder, Pitt–Hopkins syndrome (PTHS), and healthy individuals through the identification of morphological facial features. The input data consist of frontal facial photographs in which faces are located using histograms of oriented gradients feature descriptors. Pre-processing steps include color normalization and enhancement, scaling down, rotation, and cropping of pictures to produce a series of images of faces with consistent dimensions. Sixty-eight facial landmarks are automatically located on each face through a cascade of regression functions learnt via gradient boosting to estimate the shape from an initial approximation. The intensities of a sparse set of pixels indexed relative to this initial estimate are used to determine the landmarks. A set of carefully selected geometric features, for example, the relative width of the mouth or angle of the nose, is extracted from the landmarks. The features are used to investigate the statistical differences between the two populations of PTHS and healthy controls. The methodology was tested on 71 individuals with PTHS and 55 healthy controls. The software was able to classify individuals with an accuracy rate of 91%, while pediatricians achieved a recognition rate of 74%. Two geometric features related to the nose and mouth showed significant statistical difference between the two populations.

Technology, Engineering (General). Civil engineering (General)

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