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1.
Phys Rev Lett ; 132(9): 091801, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38489635

RESUMO

If dark matter is ultralight, the number density of dark matter is very high, and the techniques of zero-temperature field theory are no longer valid. The dark matter number density modifies the vacuum, giving it a non-negligible particle occupation number. For fermionic dark matter, this occupation number can be no larger than one. However, in the case of bosons, the occupation number is unbounded. If there is a large occupation number, the Bose enhancement needs to be taken into consideration for any process involving particles which interact with the dark matter. Because the occupation number scales inversely with the dark matter mass, this effect is most prominent for ultralight dark matter. In fact, the Bose enhancement effect from the background is so significant for ultralight dark matter that, if dark matter is a dark photon, the correction to the anomalous magnetic moment is larger than experimental uncertainties for a mixing parameter of the order of 10^{-16} and a dark photon mass of the order of 10^{-20} eV. Furthermore, the constraint on the mixing parameter scales linearly with the dark photon mass, and so new significant constraints can be placed on the dark matter mass all the way up to 10^{-14} eV. Future experiments measuring g-2 will probe even smaller gauge mixing parameters.

2.
Sci Adv ; 10(10): eadj3460, 2024 Mar 08.
Artigo em Inglês | MEDLINE | ID: mdl-38446893

RESUMO

We examine the characteristics and causes of southeast Australia's Tinderbox Drought (2017 to 2019) that preceded the Black Summer fire disaster. The Tinderbox Drought was characterized by cool season rainfall deficits of around -50% in three consecutive years, which was exceptionally unlikely in the context of natural variability alone. The precipitation deficits were initiated and sustained by an anomalous atmospheric circulation that diverted oceanic moisture away from the region, despite traditional indicators of drought risk in southeast Australia generally being in neutral states. Moisture deficits were intensified by unusually high temperatures, high vapor pressure deficits, and sustained reductions in terrestrial water availability. Anthropogenic forcing intensified the rainfall deficits of the Tinderbox Drought by around 18% with an interquartile range of 34.9 to -13.3% highlighting the considerable uncertainty in attributing droughts of this kind to human activity. Skillful predictability of this drought was possible by incorporating multiple remote and local predictors through machine learning, providing prospects for improving forecasting of droughts.


Assuntos
Mudança Climática , Secas , Humanos , Austrália , Temperatura Baixa , Aprendizado de Máquina
3.
Nat Commun ; 15(1): 1703, 2024 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-38402212

RESUMO

Fusion-positive rhabdomyosarcoma (FP-RMS) is an aggressive pediatric sarcoma driven primarily by the PAX3-FOXO1 fusion oncogene, for which therapies targeting PAX3-FOXO1 are lacking. Here, we screen 62,643 compounds using an engineered cell line that monitors PAX3-FOXO1 transcriptional activity identifying a hitherto uncharacterized compound, P3FI-63. RNA-seq, ATAC-seq, and docking analyses implicate histone lysine demethylases (KDMs) as its targets. Enzymatic assays confirm the inhibition of multiple KDMs with the highest selectivity for KDM3B. Structural similarity search of P3FI-63 identifies P3FI-90 with improved solubility and potency. Biophysical binding of P3FI-90 to KDM3B is demonstrated using NMR and SPR. P3FI-90 suppresses the growth of FP-RMS in vitro and in vivo through downregulating PAX3-FOXO1 activity, and combined knockdown of KDM3B and KDM1A phenocopies P3FI-90 effects. Thus, we report KDM inhibitors P3FI-63 and P3FI-90 with the highest specificity for KDM3B. Their potent suppression of PAX3-FOXO1 activity indicates a possible therapeutic approach for FP-RMS and other transcriptionally addicted cancers.


Assuntos
Rabdomiossarcoma Alveolar , Rabdomiossarcoma , Criança , Humanos , Fatores de Transcrição Box Pareados/genética , Fatores de Transcrição Box Pareados/metabolismo , Rabdomiossarcoma Alveolar/genética , Linhagem Celular Tumoral , Rabdomiossarcoma/tratamento farmacológico , Rabdomiossarcoma/genética , Proteína Forkhead Box O1/genética , Proteína Forkhead Box O1/metabolismo , Proteínas de Fusão Oncogênica/genética , Proteínas de Fusão Oncogênica/metabolismo , Regulação Neoplásica da Expressão Gênica , Fator de Transcrição PAX3/genética , Fator de Transcrição PAX3/metabolismo , Histona Desmetilases com o Domínio Jumonji/genética , Histona Desmetilases com o Domínio Jumonji/metabolismo , Histona Desmetilases/metabolismo
4.
Cancer Res Commun ; 3(8): 1716-1730, 2023 08.
Artigo em Inglês | MEDLINE | ID: mdl-37663929

RESUMO

Epigenetic reprogramming, mediated by genomic alterations and dysregulation of histone reader and writer proteins, plays a critical role in driving prostate cancer progression and treatment resistance. However, the specific function and regulation of EHMT1 (also known as GLP) and EHMT2 (also known as G9A), well-known histone 3 lysine 9 methyltransferases, in prostate cancer progression remain poorly understood. Through comprehensive investigations, we discovered that both EHMT1 and EHMT2 proteins have the ability to activate oncogenic transcription programs in prostate cancer cells. Silencing EHMT1/2 or targeting their enzymatic activity with small-molecule inhibitors can markedly decrease prostate cancer cell proliferation and metastasis in vitro and in vivo. In-depth analysis of posttranslational modifications of EHMT1 protein revealed the presence of methylation at lysine 450 and 451 residues in multiple prostate cancer models. Notably, we found that lysine 450 can be demethylated by LSD1. Strikingly, concurrent demethylation of both lysine residues resulted in a rapid and profound expansion of EHMT1's chromatin binding capacity, enabling EHMT1 to reprogram the transcription networks in prostate cancer cells and activate oncogenic signaling pathways. Overall, our studies provide valuable molecular insights into the activity and function of EHMT proteins during prostate cancer progression. Moreover, we propose that the dual-lysine demethylation of EHMT1 acts as a critical molecular switch, triggering the induction of oncogenic transcriptional reprogramming in prostate cancer cells. These findings highlight the potential of targeting EHMT1/2 and their demethylation processes as promising therapeutic strategies for combating prostate cancer progression and overcoming treatment resistance. Significance: In this study, we demonstrate that EHMT1 and EHMT2 proteins drive prostate cancer development by transcriptionally activating multiple oncogenic pathways. Mechanistically, the chromatin binding of EHMT1 is significantly expanded through demethylation of both lysine 450 and 451 residues, which can serve as a critical molecular switch to induce oncogenic transcriptional reprogramming in prostate cancer cells.


Assuntos
Hiperplasia Prostática , Neoplasias da Próstata , Masculino , Humanos , Lisina , Histonas , Processos Neoplásicos , Neoplasias da Próstata/genética , Histona-Lisina N-Metiltransferase/genética , Cromatina , Desmetilação , Antígenos de Histocompatibilidade
5.
J Funct Biomater ; 14(9)2023 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-37754863

RESUMO

Catecholamine metabolites are not only involved in primary metabolism, but also in secondary metabolism, serving a diverse array of physiologically and biochemically important functions. Melanin, which originates from dopa and dopamine, found in the hair, eye, and skin of all animals, is an important biopolymeric pigment. It provides protection against damaging solar radiation to animals. N-Acetyldopamine and N-ß-alanyldopamine play a crucial role in the hardening of the exoskeletons of all insects. In addition, insects and other arthropods utilize the melanogenic process as a key component of their defense systems. Many marine organisms utilize dopyl peptides and proteins as bonding materials to adhere to various substrata. Moreover, the complex dopa derivatives that are precursors to the formation of the exoskeletons of numerous marine organisms also exhibit antibiotic properties. The biochemistry and mechanistic transformations of different catecholamine derivatives to produce various biomaterials with antioxidant, antibiotic, crosslinking, and gluing capabilities are highlighted. These reactivities are exhibited through the transient and highly reactive quinones, quinone methides, and quinone methide imine amide intermediates, as well as chelation to metal ions. A careful consideration of the reactivities summarized in this review will inspire numerous strategies for synthesizing novel biomaterials for future medical and industrial use.

6.
Nutrients ; 15(18)2023 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-37764827

RESUMO

Diet-related chronic disease is a public health epidemic in the United States. Concurrently, conventional agricultural and food production methods deplete the nutritional content of many foods, sever connections between people and the origin of their food, and play a significant role in climate change. Paradoxically, despite an abundance of available food in the US, many households are unable to afford or attain a healthful diet. The linkages between agriculture, health, and nutrition are undeniable, yet conventional agriculture and healthcare systems tend to operate in silos, compounding these pressing challenges. Operating teaching kitchens in collaboration with local agriculture, including farms, community gardens, vertical farms, and urban agriculture, has the potential to catalyze a movement that emphasizes the role of the food system in promoting human and planetary health, building resilient communities, and encouraging cross-disciplinary collaboration. This paper reviews the current state of agricultural systems, food is medicine, consumer behavior, and the roles within these sectors. This is followed by a series of case studies that fill the gaps between TKs and agriculture. The authors summarize opportunities to combine the knowledge and resources of teaching kitchens and agriculture programs, as well as challenges that may arise along the way.

7.
iScience ; 26(9): 107696, 2023 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-37680461

RESUMO

Although climate models have been used to assess compound events, the combination of multiple hazards or drivers poses uncertainties because of the systemic biases present. Here, we investigate multivariate bias correction for correcting systemic bias in the boundaries that form the inputs of regional climate models (RCMs). This improves the representation of physical relationships among variables, essential for accurate characterization of compound events. We address four types of compound events that result from eight different hazards. The results show that while the RCM simulations presented here exhibit similar performance for some event types, the multivariate bias correction broadly improves the RCM representation of compound events compared to no correction or univariate correction, particularly for coincident high temperature and high precipitation. The RCM with uncorrected boundaries tends to produce a negative bias in the return period of these events, suggesting a tendency to over-simulate compound events with respect to observed events.

8.
Top Companion Anim Med ; 56-57: 100806, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37619774

RESUMO

A 7-month-old female spayed domestic short hair cat was presented for evaluation of inadequate clinical response to medical management for hepatic encephalopathy (HE). An abdominal computed tomography (CT) was to be performed but the cat developed 2 grand mal seizures shortly after presentation. Minimal handling and no drugs had been administered before the seizures. A single dose of diazepam (0.3 mg/kg, IV) was administered after each seizure. Another seizure occurred 24 hours after hospitalization and diazepam (0.5 mg/kg, IV) was once again administered. Seizures ceased but neurological signs worsened and included head pressing, loss of menace response, and a stuporous mentation. Due to unresponsiveness to treatment that included administration of intravenous fluids, levetiracetam, ampicillin/sulbactam, and retention enemas (water with lactulose), a dose of flumazenil (0.01 mg/kg) was administered IV and resulted in immediate but transient improvement of clinical signs. The stuporous state returned after 60 min post-treatment and an additional dose of IV flumazenil (0.01 mg/kg) was administered with the same outcome. Based on this positive clinical response, IV infusion of flumazenil was initiated at 0.01 mg/kg/h following a loading dose of 0.005 mg/kg. Due to minimal improvement in neurological signs, flumazenil IV infusion was increased gradually until reaching the effective dose of 0.1 mg/kg/h. Flumazenil IV infusion was continued for 24 hours with improvements in neurological signs, which did not return upon gradual decrease of the flumazenil dose. This is the first report describing the use of a flumazenil IV infusion to improve neurological signs in a cat with a PSS and HE treated with diazepam.


Assuntos
Doenças do Gato , Derivação Portossistêmica Transjugular Intra-Hepática , Gatos , Feminino , Animais , Diazepam/uso terapêutico , Flumazenil/uso terapêutico , Derivação Portossistêmica Transjugular Intra-Hepática/veterinária , Convulsões/veterinária , Catalase , Doenças do Gato/tratamento farmacológico
9.
Sci Rep ; 13(1): 11503, 2023 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-37532699

RESUMO

Increasing levels of photovoltaic (PV) penetration to the electricity grid brings challenges to both design and operation of the grid due to its vulnerability to climate change. A crucial aspect of PV operation is power ramps leading to variability and instability in the grid. With notable large-scale PV deployment planned, including the world's largest planned solar energy infrastructure in Powell Creek Australia, characterising future ramps is crucial for ensuring stable power generation to support large-scale economic development. Using CORDEX-Australasia projections under RCP8.5 and RCP4.5 emission scenarios, future solar ramps across Australia have been characterised up to 2100. Results predict a reduction in ramp magnitude across Australia, with changes in frequency and period length varying with the location. This work highlights the importance of considering future changes in climate when designing large-scale solar farms to ensure the incorporation of frequency control devices and storage plans for a reliable power supply.

10.
ACS Infect Dis ; 9(6): 1245-1256, 2023 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-37163243

RESUMO

The continuing emergence of antibiotic-resistant microbes highlights the need for the identification of new chemotypes with antimicrobial activity. One of the most prolific sources of antimicrobial molecules has been the systematic screening of natural product samples. The National Institute of Allergy and Infectious Diseases and the National Cancer Institute here report a large screen of 326,656 partially purified natural product fractions against a panel of four microbial pathogens, resulting in the identification of >3000 fractions with antifungal and/or antibacterial activity. A small sample of these active fractions was further purified and the chemical structures responsible for the antimicrobial activity were elucidated. The proof-of-concept study identified many different chemotypes, several of which have not previously been reported to have antimicrobial activity. The results show that there remain many unidentified antibiotic compounds from nature.


Assuntos
Anti-Infecciosos , Produtos Biológicos , Estados Unidos , Produtos Biológicos/farmacologia , Produtos Biológicos/química , National Cancer Institute (U.S.) , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Extratos Vegetais
11.
J Natl Cancer Inst ; 115(11): 1404-1419, 2023 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-37195421

RESUMO

BACKGROUND: We investigated the role of A2B-adenosine receptor in regulating immunosuppressive metabolic stress in the tumor microenvironment. Novel A2B-adenosine receptor antagonist PBF-1129 was tested for antitumor activity in mice and evaluated for safety and immunologic efficacy in a phase I clinical trial of patients with non-small cell lung cancer. METHODS: The antitumor efficacy of A2B-adenosine receptor antagonists and their impact on the metabolic and immune tumor microenvironment were evaluated in lung, melanoma, colon, breast, and epidermal growth factor receptor-inducible transgenic cancer models. Employing electron paramagnetic resonance, we assessed changes in tumor microenvironment metabolic parameters, including pO2, pH, and inorganic phosphate, during tumor growth and evaluated the immunologic effects of PBF-1129, including its pharmacokinetics, safety, and toxicity, in patients with non-small cell lung cancer. RESULTS: Levels of metabolic stress correlated with tumor growth, metastasis, and immunosuppression. Tumor interstitial inorganic phosphate emerged as a correlative and cumulative measure of tumor microenvironment stress and immunosuppression. A2B-adenosine receptor inhibition alleviated metabolic stress, downregulated expression of adenosine-generating ectonucleotidases, increased expression of adenosine deaminase, decreased tumor growth and metastasis, increased interferon γ production, and enhanced the efficacy of antitumor therapies following combination regimens in animal models (anti-programmed cell death 1 protein vs anti-programmed cell death 1 protein plus PBF-1129 treatment hazard ratio = 11.74 [95% confidence interval = 3.35 to 41.13], n = 10, P < .001, 2-sided F test). In patients with non-small cell lung cancer, PBF-1129 was well tolerated, with no dose-limiting toxicities; demonstrated pharmacologic efficacy; modulated the adenosine generation system; and improved antitumor immunity. CONCLUSIONS: Data identify A2B-adenosine receptor as a valuable therapeutic target to modify metabolic and immune tumor microenvironment to reduce immunosuppression, enhance the efficacy of immunotherapies, and support clinical application of PBF-1129 in combination therapies.


Assuntos
Carcinoma Pulmonar de Células não Pequenas , Neoplasias Pulmonares , Humanos , Animais , Camundongos , Carcinoma Pulmonar de Células não Pequenas/tratamento farmacológico , Receptor A2B de Adenosina/metabolismo , Microambiente Tumoral , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Terapia de Imunossupressão , Adenosina/metabolismo , Fosfatos , Linhagem Celular Tumoral
12.
ACS Omega ; 8(10): 9250-9256, 2023 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-36936303

RESUMO

National Cancer Institute (NCI) Program for Natural Product Discovery is a new initiative aimed at creating new technologies for natural product-based drug discovery. Here, we present the development of a neural network-based bioinformatics platform for visualization and analysis of natural product high-throughput screening data using the NCI's 60 human tumor cell anticancer drug screen. We demonstrate how the tool enables visualization of similar patterns of response that can be parsed both chemically and taxonomically, grouping NCI-60 biological profiles in one easy-to-use bioinformatics interface.

13.
Scand J Trauma Resusc Emerg Med ; 31(1): 7, 2023 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-36782273

RESUMO

BACKGROUND: Community First Responder (CFR) schemes are a long-established service supplementing ambulance trusts in their local community in the United Kingdom. CFRs are community members who volunteer to respond to people with life-threatening conditions. Previous studies highlighted the motivations for becoming CFRs, their training, community (un)awareness and implications of their work on themselves and others. The practices of CFRs in prehospital care remain underexplored. Therefore, we aimed to explore real-world practice of Community First Responders and their contribution to prehospital emergency care. METHODS: We conducted 47 interviews with CFRs (21), CFR leads (15), ambulance clinicians (4), commissioners (2) and patients and relatives (5) from six ambulance services and regions of England, United Kingdom. Thematic analysis enabled identification of themes and subthemes, with subsequent interpretation built on the theory of practice wisdom. RESULTS: Our analysis revealed the embeddedness of the concept of doing the right thing at the right time in CFR practice. CFRs' work consisted of a series of sequential and interconnected activities which included: identifying patients' signs, symptoms and problems; information sharing with the ambulance control room on the patient's condition; providing a rapid emergency response including assessment and care; and engaging with ambulance clinicians for patient transfer. The patient care sequence began with recognising patients' signs and symptoms, and validation of patient information provided by the ambulance control room. The CFRs shared patient information with ambulance control who in turn notified the ambulance crew en-route. The practices of CFRs also included delivery of emergency care before ambulance clinicians arrived. Following the delivery of a rapid emergency response, CFRs engaged with the ambulance crew to facilitate patient transfer to the nearest medical facility. CONCLUSION: The sequential CFR practices supported ambulance services in delivering prehospital and emergency care in rural areas. CFR practices were founded on the principle of practice wisdom where CFRs constructed their practice decisions based on the patient's condition, their training, availability of equipment and medications and their scope of practice.


Assuntos
Anseriformes , Serviços Médicos de Emergência , Socorristas , Humanos , Animais , Reino Unido , Inglaterra , Pesquisa Qualitativa
14.
Pharmaceutics ; 14(11)2022 Nov 11.
Artigo em Inglês | MEDLINE | ID: mdl-36432630

RESUMO

The effect of preformed protein coronas on immunoassays for Dengue nonstructural protein 1 (NS1) immunoassays was investigated. The composition of the protein corona that forms around nanoparticle-antibody conjugates in human serum was characterized, and selected proteins from the corona were used for preformed coronas (human serum albumin and apolipoprotein A1). Coronas were formed and characterized by dynamic light scattering (DLS), and the nanoparticle-conjugate was probed by optical absorption spectroscopy. Immunoassays were run, and performance was quantified by analyzing the strip intensity as a function of NS1 concentration. The preformed coronas influenced the limit of detection (LOD) of the assay and the affinity for the NS1 target (KD). The resulting KD and LODs for the NP-Ab-ApoA1 immunoprobes were 0.83 nM and 1.24 nM, respectively. For the NP-Ab -HSA coronas, the test line intensity was lower by 33% at a given NS1 concentration than for the NP-Ab immunoprobes, and KD was 0.14 nM, a slightly higher affinity. Due to the relatively large error of the negative control, a meaningful LOD for the NP-Ab with HSA coronas could not be determined.

15.
Science ; 378(6620): 655-659, 2022 11 11.
Artigo em Inglês | MEDLINE | ID: mdl-36356148

RESUMO

Short-duration rainfall extremes can cause flash flooding with associated impacts. Previous studies of climate impacts on extreme precipitation have focused mainly on daily rain totals. Subdaily extremes are often generated in small areas that can be missed by gauge networks or satellites and are not resolved by climate models. Here, we show a robust positive trend of at least 20% per decade in subhourly extreme rainfall near Sydney, Australia, over 20 years, despite no evidence of trends at hourly or daily scales. This trend is seen consistently in storms tracked using multiple independent ground radars, is consistent with rain-gauge data, and does not appear to be associated with known natural variations. This finding suggests that subhourly rainfall extremes may be increasing substantially faster than those on more widely reported time scales.


Assuntos
Inundações , Chuva , Clima , Austrália
16.
Proc Natl Acad Sci U S A ; 119(8)2022 02 22.
Artigo em Inglês | MEDLINE | ID: mdl-35173043

RESUMO

Safe and efficacious systemic delivery of messenger RNA (mRNA) to specific organs and cells in vivo remains the major challenge in the development of mRNA-based therapeutics. Targeting of systemically administered lipid nanoparticles (LNPs) coformulated with mRNA has largely been confined to the liver and spleen. Using a library screening approach, we identified that N-series LNPs (containing an amide bond in the tail) are capable of selectively delivering mRNA to the mouse lung, in contrast to our previous discovery that O-series LNPs (containing an ester bond in the tail) that tend to deliver mRNA to the liver. We analyzed the protein corona on the liver- and lung-targeted LNPs using liquid chromatography-mass spectrometry and identified a group of unique plasma proteins specifically absorbed onto the surface that may contribute to the targetability of these LNPs. Different pulmonary cell types can also be targeted by simply tuning the headgroup structure of N-series LNPs. Importantly, we demonstrate here the success of LNP-based RNA therapy in a preclinical model of lymphangioleiomyomatosis (LAM), a destructive lung disease caused by loss-of-function mutations in the Tsc2 gene. Our lung-targeting LNP exhibited highly efficient delivery of the mouse tuberous sclerosis complex 2 (Tsc2) mRNA for the restoration of TSC2 tumor suppressor in tumor and achieved remarkable therapeutic effect in reducing tumor burden. This research establishes mRNA LNPs as a promising therapeutic intervention for the treatment of LAM.


Assuntos
Sistemas de Liberação de Medicamentos/métodos , Linfangioleiomiomatose/tratamento farmacológico , RNA Mensageiro/administração & dosagem , Animais , Feminino , Técnicas de Transferência de Genes , Engenharia Genética/métodos , Lipossomos/química , Lipossomos/farmacologia , Pulmão/citologia , Pulmão/patologia , Pneumopatias/tratamento farmacológico , Pneumopatias/metabolismo , Linfangioleiomiomatose/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Nanopartículas/química , Coroa de Proteína/química , Coroa de Proteína/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/farmacologia , RNA Interferente Pequeno/metabolismo
17.
Rapid Commun Mass Spectrom ; 36(4): e9226, 2022 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-34820920

RESUMO

RATIONALE: The development of an automated platform for the positional analysis of triglycerides (TAGs) based on electrospray ionization tandem mass spectrometry (ESI-MS/MS) continues to be pursued. This work evaluates the positional sensitivities of the collision-induced dissociation (CID) spectra of a representative set of XYZ triglycerides using sodium, lithium, and ammonium salts as complexing agents. METHODS: A set of triglycerides were synthesized and analyzed via ESI-MS/MS using an ion trap mass spectrometer. Using three different complexing agents, the product ion spectra of the corresponding precursor ions for twelve XYZ TAGs were collected, where X, Y, and Z represent C16:0 , C18:1(c-9) , C18:2(cc-9,12) , and C20:4(cccc-5,8,11,14) fatty acid chains. These data were then used to prepare ternary plots for four positional isomer systems to evaluate the positional sensitivity differences among the three different complexing agents. RESULTS: The positional sensitivities for each of the four positional isomer systems were robust for the sodium and lithium adducts. The CID data for the sodium and lithium TAGs demonstrated an unfavorable loss of the fatty acid in the center position and showed a higher sensitivity to fatty acid position, when compared with the CID data for ammonium adducts, especially for the arachidonic acid containing triglycerides. CONCLUSIONS: The data shows that that the relative abundances of the DAG product ions for the XYZ-type TAGs when using sodium and lithium complexing agent adducts are sensitive to fatty acid position and are consistent for the diverse array of TAGs studied in this work. This suggests that using sodium or lithium as the complexing agent may be advantageous for the development of an automated platform for the positional analysis of complex TAG mixtures based on ESI-MS/MS.

18.
J Environ Manage ; 304: 114221, 2022 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-34891054

RESUMO

Floods are recognized as the costliest type of natural hazard both worldwide and in the United States, with projected increases in frequency and magnitude in the absence of effective adaptation strategies. In the fall of 2018, Hurricane Florence made landfall in southeastern North Carolina, USA, bringing record rainfall and resulting in widespread inundation that impacted many areas outside of the federally designated Special Flood Hazard Area (SFHA). Much of this flooding was from inland pluvial inundation, which is an understudied component of coastal risk and vulnerability assessments primarily due to the scarcity of infrastructure data and historically lower flooding recurrence rates. This has resulted in severe damages in areas that residents and local officials considered at low risk from flooding. Using nearly-coincident high-spatial, high-temporal resolution CubeSat satellite imagery, we quantified the areal extent of post-Hurricane Florence floodwater within and beyond the 100-year floodplain (SFHA) and the proportion of residential structures exposed to flooding within an eight-county study area. We propose a novel approach to estimate flood risk resulting from this singular event (termed an actualized risk index) when compared to a published empirical model of vulnerability. We show that 24.3% of detected floodwater was outside the 100-year floodplain, 43.4% of exposed residential structures are outside the 100-year floodplain, and communities of highest vulnerability are not only along the coast but also inland along the Cape Fear, Northeast Cape Fear, Trenton, and Neuse Rivers. This suggests that the SFHA may not adequately show the spatial distribution of pluvial flood risk in riverine areas, and that misunderstanding of this risk has led to a pattern of development in which houses have a higher than expected risk of flooding. Moreover, this additional flood risk may disproportionately affect lower-income residents of these largely rural areas. These results have important implications in light of recent policy guidance in southeastern USA states that mandate that predictive coastal vulnerability assessments to sea level rise be conducted relative to 100-year SFHA zones.


Assuntos
Tempestades Ciclônicas , Inundações , Previsões , North Carolina , Rios , Imagens de Satélites
19.
Conserv Biol ; 36(3): e13872, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-34856018

RESUMO

International demand for wood and other forest products continues to grow rapidly, and uncertainties remain about how animal communities will respond to intensifying resource extraction associated with woody bioenergy production. We examined changes in alpha and beta diversity of bats, bees, birds, and reptiles across wood production landscapes in the southeastern United States, a biodiversity hotspot that is one of the principal sources of woody biomass globally. We sampled across a spatial gradient of paired forest land-uses (representing pre and postharvest) that allowed us to evaluate biological community changes resulting from several types of biomass harvest. Short-rotation practices and residue removal following clearcuts were associated with reduced alpha diversity (-14.1 and -13.9 species, respectively) and lower beta diversity (i.e., Jaccard dissimilarity) between land-use pairs (0.46 and 0.50, respectively), whereas midrotation thinning increased alpha (+3.5 species) and beta diversity (0.59). Over the course of a stand rotation in a single location, biomass harvesting generally led to less biodiversity. Cross-taxa responses to resource extraction were poorly predicted by alpha diversity: correlations in responses between taxonomic groups were highly variable (-0.2 to 0.4) with large uncertainties. In contrast, beta diversity patterns were highly consistent and predictable across taxa, where correlations in responses between taxonomic groups were all positive (0.05-0.4) with more narrow uncertainties. Beta diversity may, therefore, be a more reliable and information-rich indicator than alpha diversity in understanding animal community response to landscape change. Patterns in beta diversity were primarily driven by turnover instead of species loss or gain, indicating that wood extraction generates habitats that support different biological communities.


Conservación de la Diversidad Alfa y Beta en Paisajes de Producción Maderera Resumen La demanda internacional de madera y otros productos forestales sigue creciendo rápidamente mientras permanecen las incertidumbres sobre cómo responderán las comunidades animales a la intensificación de la extracción de recursos asociada con la producción de bioenergía leñosa. Examinamos los cambios en la diversidad alfa y beta de murciélagos, abejas, aves y reptiles en los paisajes de producción maderera en el sureste de los Estados Unidos, un punto caliente de biodiversidad y una de las fuentes principales de biomasa leñosa a nivel mundial. Muestreamos a lo largo de un gradiente espacial de usos de suelo forestales emparejados (representando la pre- y postcosecha) que nos permitió evaluar los cambios en las comunidades biológicas resultantes de varios tipos de recolección de biomasa. Las prácticas de corta rotación y de eliminación de residuos después de la tala estuvieron asociadas con la reducción de la diversidad alfa (−14.1 y −13.9 especies, respectivamente) y una diversidad beta más baja (es decir, diferencia de Jaccard) entre los pares de uso de suelo (0.46 y 0.50, respectivamente), mientras que el raleo de rotación media incrementó la diversidad alfa (+3.5 especies) y beta (0.59). Durante la duración de una rotación permanente en una sola ubicación, la cosecha de biomasa generalmente derivó en menos biodiversidad. La respuesta de los taxones a la extracción de recursos estuvo muy mal pronosticada por la diversidad alfa: la correlación de las respuestas entre los grupos taxonómicos fue altamente variable (−0.2 a 0.4) con muchas incertidumbres. Como contraste, los patrones de diversidad beta fueron fuertemente coherentes y predecibles en todos los taxones, mientras que la correlación de las respuestas entre los grupos taxonómicos siempre fue positiva (0.05 a 0.4) con incertidumbres más limitadas. Por lo tanto, la diversidad beta puede ser un indicador más confiable y rico en información que la diversidad alfa para entender las respuestas de la comunidad animal a los cambios en el paisaje. Los patrones de la diversidad beta estuvieron impulsados principalmente por la rotación en lugar de la pérdida o ganancia de especies, lo que indica que la extracción de madera genera hábitats que mantienen a diferentes comunidades biológicas.


Assuntos
Conservação dos Recursos Naturais , Madeira , Animais , Biodiversidade , Ecossistema , Florestas
20.
J Org Chem ; 86(23): 17395-17403, 2021 12 03.
Artigo em Inglês | MEDLINE | ID: mdl-34797667

RESUMO

A pseudo-five-component reaction involving double decarboxylative 1,3-dipolar cycloaddition of azomethine ylides with olefinic oxindoles for the diastereoselective synthesis of bispiro[oxindole-pyrrolidine]s is developed. The major diastereomers are unique butterfly shaped compounds with a plane of symmetry. Recyclable zeolite HY acid catalyst is used to promote the reaction, and only CO2 and H2O are generated as byproducts.


Assuntos
Pirrolidinas , Catálise , Reação de Cicloadição , Oxindóis
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