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79 result(s) for "GONZÁLEZ, OLGA RAMOS"
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The green areas of San Juan, Puerto Rico
Green areas, also known as green infrastructure or urban vegetation, are vital to urbanites for their critical roles in mitigating urban heat island effects and climate change and for their provision of multiple ecosystem services and aesthetics. Here, I provide a high spatial resolution snapshot of the green cover distribution of the city of San Juan, Puerto Rico, by incorporating the use of morphological spatial pattern analysis (MSPA) as a tool to describe the spatial pattern and connectivity of the city’s urban green areas. Analysis of a previously developed IKONOS 4-m spatial resolution classification of the city of San Juan from 2002 revealed a larger area of vegetation (green areas or green infrastructure) than previously estimated by moderate spatial resolution imagery. The city as a whole had approximately 42% green cover and 55% impervious surfaces. Although the city appeared greener in its southern upland sector compared to the northern coastal section, where most built-up urban areas occurred (66% impervious surfaces), northern San Juan had 677 ha more green area cover dispersed across the city than the southern component. MSPA revealed that most forest cover occurred as edges and cores, and green areas were most commonly forest cores, with larger predominance in the southern sector of the municipality. In dense, built-up, urban land, most of the green areas occurred in private yards as islets. When compared to other cities across the United States, San Juan was most similar in green cover features to Boston, Massachusetts, and Miami, Florida. Per capita green space for San Juan (122.2 m²/inhabitant) was also comparable to these two U.S. cities. This study explores the intra-urban vegetation variation in the city of San Juan, which is generally overlooked by moderate spatial resolution classifications in Puerto Rico. It serves as a starting point for green infrastructure mapping and landscape pattern analysis of the urban green spaces within the city of San Juan. The effectiveness of research and city planning will be further enhanced as a result of this type of finer-scale urban cover exploration.
Vegetation cover in relation to socioeconomic factors in a tropical city assessed from sub-meter resolution imagery
Fine-scale information about urban vegetation and social-ecological relationships is crucial to inform both urban planning and ecological research, and high spatial resolution imagery is a valuable tool for assessing urban areas. However, urban ecology and remote sensing have largely focused on cities in temperate zones. Our goal was to characterize urban vegetation cover with sub-meter (<1 m) resolution aerial imagery, and identify social-ecological relationships of urban vegetation patterns in a tropical city, the San Juan Metropolitan Area, Puerto Rico. Our specific objectives were to (1) map vegetation cover using sub-meter spatial resolution (0.3-m) imagery, (2) quantify the amount of residential and non-residential vegetation, and (3) investigate the relationship between patterns of urban vegetation vs. socioeconomic and environmental factors. We found that 61% of the San Juan Metropolitan Area was green and that our combination of high spatial resolution imagery and object-based classification was highly successful for extracting vegetation cover in a moist tropical city (97% accuracy). In addition, simple spatial pattern analysis allowed us to separate residential from non-residential vegetation with 76% accuracy, and patterns of residential and non-residential vegetation varied greatly across the city. Both socioeconomic (e.g., population density, building age, detached homes) and environmental variables (e.g., topography) were important in explaining variations in vegetation cover in our spatial regression models. However, important socioeconomic drivers found in cities in temperate zones, such as income and home value, were not important in San Juan. Climatic and cultural differences between tropical and temperate cities may result in different social-ecological relationships. Our study provides novel information for local land use planners, highlights the value of high spatial resolution remote sensing data to advance ecological research and urban planning in tropical cities, and emphasizes the need for more studies in tropical cities.
Spatio-temporal variation in stream water chemistry in a tropical urban watershed
Urban activities and related infrastructure alter the natural patterns of stream physical and chemical conditions. According to the Urban Stream Syndrome, streams draining urban landscapes are characterized by high concentrations of nutrients and ions, and might have elevated water temperatures and variable oxygen concentrations. Here, we report temporal and spatial variability in stream physicochemistry in a highly urbanized watershed in Puerto Rico. The main objective of the study was to describe stream physicochemical characteristics and relate them to urban intensity, e.g., percent impervious surface cover, and watershed infrastructure, e.g., road and pipe densities. The Río Piedras Watershed in the San Juan Metropolitan Area, Puerto Rico, is one of the most urbanized regions on the island. The Río Piedras presented high solute concentrations that were related to watershed factors, such as percent impervious cover. Temporal variability in ion concentrations lacked seasonality, as did all other parameters measured except water temperature, which was lower during winter and highest during summer, as expected based on latitude. Spatially, stream physicochemistry was strongly related to watershed percent impervious cover and also to the density of urban infrastructure, e.g., roads, pipe, and building densities. Although the watershed is serviced by a sewage collection system, illegal discharges and leaky infrastructure are probably responsible for the elevated ion concentration found. Overall, the Río Piedras is an example of the response of a tropical urban watershed after major sewage inputs are removed, thus highlighting the importance of proper infrastructure maintenance and management of runoff to control ion concentrations in tropical streams.
Long-Term Research at the USDA Forest Service's Experimental Forests and Ranges
The network of experimental forests and ranges administered by the US Department of Agriculture Forest Service consists of 77 properties that are representative of most forest cover types and many ecological regions in the nation. Established as early as 1908, these sites maintain exceptional, long-term databases on environmental dynamics and biotic responses. Early research at these sites focused on silviculture, ecosystem restoration, and watershed management. Over time, many of the properties have evolved into a functional network of ecological observatories through common large-scale, long-term experiments and other approaches. Collaboration with other institutions and research programs fosters intersite research and common procedures for managing and sharing data. Much current research in this network focuses on global change and interdisciplinary ecosystem studies at local to global scales. With this experience in developing networks and compiling records of environmental history, the experimental forests and ranges network can contribute greatly to formation of new networks of environmental observatories.
Endogenous pathway dysregulation in Kluyveromyces marxianus under nitrogen limitation drives 2-phenylethyl acetate and 2-phenylethanol overproduction
The aromatic compounds 2-phenylethanol (2-PE) and 2-phenylethyl acetate (2-PEA) are of high industrial relevance due to their distinctive sensory properties and extensive use in food, fragrance, and wine industries. However, their natural production is costly, motivating interest in sustainable microbial alternatives. This study examined the metabolic regulation of Kluyveromyces marxianus ITD0090, a non-conventional yeast, under nitrogen-limited conditions for enhanced 2-PE and 2-PEA production. Combined genomic and transcriptomic analyses revealed key regulatory points associated with aromatic biosynthesis. K. marxianus ITD0090 showed remarkable metabolic flexibility, favoring 2-PEA over 2-PE. ARO9 overexpression appeared to compensate for ARO8 inactivation, while the shikimate pathway remained active despite external L-phenylalanine, supporting de novo phenylalanine synthesis. The preferential accumulation of 2-PEA may represent a cellular detoxification strategy. These results emphasize the potential of K. marxianus ITD0090 as a robust, non-engineered platform for cost-effective aroma production without genetic modification or expensive supplementation. This work provides novel insights into alternative metabolic strategies in non-conventional yeasts and opens perspectives for optimizing nitrogen- and carbon-regulated pathways to improve the sustainable production of natural flavor compounds.
Naphthoquinone Derivatives from Angustimassarina populi CF-097565 Display Anti-Tumour Activity in 3D Cultures of Breast Cancer Cells
Cancer is one of the leading causes of death worldwide, with breast cancer being the second cause of cancer-related mortality among women. Natural Products (NPs) are one of the main sources for drug discovery. During a screening campaign focused on the identification of extracts from Fundación MEDINA’s library inhibiting the proliferation of cancer cell lines, a significant bioactivity was observed in extracts from cultures of the fungus Angustimassarina populi CF-097565. Bioassay-guided fractionation of this extract led to the identification and isolation of herbarin (1), 1-hydroxydehydroherbarin (4) plus other three naphthoquinone derivatives of which 3 and 5 are new natural products and 2 is herein described from a natural source for the first time. Four of these compounds (1, 3, 4 and 5) confirmed a specific cytotoxic effect against the human breast cancer cell line MCF-7. To evaluate the therapeutic potential of the compounds isolated, their efficacy was validated in 3D cultures, a cancer model of higher functionality. Additionally, an in-depth study was carried out to test the effect of the compounds in terms of cell mortality, sphere disaggregation, shrinkage, and morphology. The cell profile of the compounds was also compared to that of known cytotoxic compounds with the aim to distinguish the drug mode of action (MoA). The profiles of 1, 3 and 4 showed more biosimilarity between them, different to 5, and even more different to other known cytotoxic agents, suggesting an alternative MoA responsible for their cytotoxicity in 3D cultures.
Effectiveness of janus kinase inhibitors in relapsing giant cell arteritis in real-world clinical practice and review of the literature
Background A substantial proportion of patients with giant cell arteritis (GCA) relapse despite standard therapy with glucocorticoids, methotrexate and tocilizumab. The Janus kinase/signal transducer and activator of transcription (JAK/STAT) signalling pathway is involved in the pathogenesis of GCA and JAK inhibitors (JAKi) could be a therapeutic alternative. We evaluated the effectiveness of JAKi in relapsing GCA patients in a real-world setting and reviewed available literature. Methods Retrospective analysis of GCA patients treated with JAKi for relapsing disease at thirteen centers in Spain and one center in United States (01/2017-12/2022). Outcomes assessed included clinical remission, complete remission and safety. Clinical remission was defined as the absence of GCA signs and symptoms regardless of the erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP) values. Complete remission was defined as the absence of GCA signs and symptoms along with normal ESR and CRP values. A systematic literature search for other JAKi-treated GCA cases was conducted. Results Thirty-five patients (86% females, mean age 72.3) with relapsing GCA received JAKi therapy (baricitinib, n  = 15; tofacitinib, n  = 10; upadacitinib, n  = 10). Before JAKi therapy, 22 (63%) patients had received conventional synthetic immunosuppressants (e.g., methotrexate), and 30 (86%) biologics (e.g., tocilizumab). After a median (IQR) follow-up of 11 (6-15.5) months, 20 (57%) patients achieved and maintained clinical remission, 16 (46%) patients achieved and maintained complete remission, and 15 (43%) patients discontinued the initial JAKi due to relapse ( n  = 11 [31%]) or serious adverse events ( n  = 4 [11%]). A literature search identified another 36 JAKi-treated GCA cases with clinical improvement reported for the majority of them. Conclusions This real-world analysis and literature review suggest that JAKi could be effective in GCA, including in patients failing established glucocorticoid-sparing therapies such as tocilizumab and methotrexate. A phase III randomized controlled trial of upadacitinib is currently ongoing (ClinicalTrials.gov ID NCT03725202).
Trends in medically serious suicide attempts before and after COVID-19: a four-year retrospective analysis (2018–2022)
Background Suicide has become a first-order public health concern after the negative impact of COVID-19 on the general population’s mental health. Several studies have analyzed the trends in suicide attempts (SA) before and after the onset of the pandemic, but few studies focus on the impact of the pandemic on medically serious suicide attempts (MSSA). Methods Participants were 385 hospitalized individuals ≥ 16 years old who made MSSA identified retrospectively through a review of e-medical records between 2018 and 2022 (“pre-COVID-19” and “COVID” periods). The two groups were compared on sociodemographic and clinical variables using Chi-square or Exact Fisher’s tests for categorical variables and a Mann-Whitney test for continuous variables. To study the variation in MSSA over time, MSSA were aggregated monthly. Joinpoint regression analyses were used to assess time trends. Results A sample of 161 MSSA patients, 80 women and 81 men, were selected from 385 admissions after a suicide attempt (SA) in the four years ( n  = 160 pre-COVID period vs. n  = 225 COVID period) (OR = 1.41; CI 95% = 1.0003–1.7223, p  < 0.001). Sixty-eight patients with MSSA were admitted during the first period, and 93 during the COVID period (OR = 1.4 ; CI 95% = 1–1.9 ; p  < 0.05). MSSA patients were more likely to be admitted to an intensive care unit during the COVID period than during the pre-COVID period (OR = 3.5; CI 95% = 1.7–6.9; p  < 0.001). Conclusions This study highlights the need for research on suicide risk during and after crisis periods, such as the COVID-19 pandemic. It provides valuable knowledge on the incidence of SA needing hospitalization, MSSA, and highly severe MSSA for four years before and after the pandemic onset.