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1.
Brain Res ; 1837: 148958, 2024 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-38685371

RESUMO

Vocal and swallowing deficits are common in Parkinson disease (PD). Because these impairments are resistant to dopamine replacement therapies, vocal and lingual exercise are the primary treatment, but not all individuals respond to exercise and neural mechanisms of treatment response are unclear. To explore putative mechanisms, we used the progressive Pink1-/- rat model of early to mid-stage PD and employed vocal and lingual exercises at 6- and 10-months of age in male Pink1-/- and wild type (WT) rats. We hypothesized that vocal and lingual exercise would improve vocal and tongue use dynamics and increase serotonin (5HT) immunoreactivity in related brainstem nuclei. Rats were tested at baseline and after 8 weeks of exercise or sham exercise. At early-stage PD (6 months), vocal exercise resulted in increased call complexity, but did not change intensity, while at mid-stage (10 months), vocal exercise no longer influenced vocalization complexity. Lingual exercise increased tongue force generation and reduced relative optical density of 5HT in the hypoglossal nucleus at both time points. The effects of vocal and lingual exercise at these time points are less robust than in prodromal stages observed in previous work, suggesting that early exercise interventions may yield greater benefit. Future work targeting optimization of exercise at later time points may facilitate clinical translation.


Assuntos
Modelos Animais de Doenças , Doença de Parkinson , Língua , Vocalização Animal , Animais , Língua/fisiopatologia , Masculino , Doença de Parkinson/fisiopatologia , Vocalização Animal/fisiologia , Proteínas Quinases/metabolismo , Proteínas Quinases/genética , Ratos , Condicionamento Físico Animal/fisiologia , Condicionamento Físico Animal/métodos , Serotonina/metabolismo , Ratos Transgênicos
2.
Nat Commun ; 15(1): 1812, 2024 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-38418834

RESUMO

Calcium carbonate (CaCO3) is abundant on Earth, is a major component of marine biominerals and thus of sedimentary and metamorphic rocks and it plays a major role in the global carbon cycle by storing atmospheric CO2 into solid biominerals. Six crystalline polymorphs of CaCO3 are known-3 anhydrous: calcite, aragonite, vaterite, and 3 hydrated: ikaite (CaCO3·6H2O), monohydrocalcite (CaCO3·1H2O, MHC), and calcium carbonate hemihydrate (CaCO3·½H2O, CCHH). CCHH was recently discovered and characterized, but exclusively as a synthetic material, not as a naturally occurring mineral. Here, analyzing 200 million spectra with Myriad Mapping (MM) of nanoscale mineral phases, we find CCHH and MHC, along with amorphous precursors, on freshly deposited coral skeleton and nacre surfaces, but not on sea urchin spines. Thus, biomineralization pathways are more complex and diverse than previously understood, opening new questions on isotopes and climate. Crystalline precursors are more accessible than amorphous ones to other spectroscopies and diffraction, in natural and bio-inspired materials.


Assuntos
Antozoários , Nácar , Animais , Carbonato de Cálcio/química , Minerais/química , Cristalização
3.
Ophthalmol Sci ; 4(2): 100416, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38170125

RESUMO

Purpose: To investigate the histology of Bruch's membrane (BM) calcification in pseudoxanthoma elasticum (PXE) and correlate this to clinical retinal imaging. Design: Experimental study with clinicopathological correlation. Subjects and Controls: Six postmortem eyes from 4 PXE patients and 1 comparison eye from an anonymous donor without PXE. One of the eyes had a multimodal clinical image set for comparison. Methods: Calcification was labeled with OsteSense 680RD, a fluorescent dye specific for hydroxyapatite, and visualized with confocal microscopy. Scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy (SEM-EDX) and time-of-flight secondary ion mass spectrometry (TOF-SIMs) were used to analyze the elemental and ionic composition of different anatomical locations. Findings on cadaver tissues were compared with clinical imaging of 1 PXE patient. Main Outcome Measures: The characteristics and topographical distribution of hydroxyapatite in BM in eyes with PXE were compared with the clinical manifestations of the disease. Results: Analyses of whole-mount and sectioned PXE eyes revealed an extensive, confluent OsteoSense labeling in the central and midperipheral BM, transitioning to a speckled labeling in the midperiphery. These areas corresponded to hyperreflective and isoreflective zones on clinical imaging. Scanning electron microscopy coupled with energy-dispersive x-ray spectroscopy and TOF-SIMs analyses identified these calcifications as hydroxyapatite in BM of PXE eyes. The confluent fluorescent appearance originates from heavily calcified fibrous structures of both the collagen and the elastic layers of BM. Calcification was also detected in an aged comparison eye, but this was markedly different from PXE eyes and presented as small snowflake-like deposits in the posterior pole. Conclusions: Pseudoxanthoma elasticum eyes show extensive hydroxyapatite deposition in the inner and outer collagenous and elastic BM layers in the macula with a gradual change toward the midperiphery, which seems to correlate with the clinical phenotype. The snowflake-like calcification in BM of an aged comparison eye differed markedly from the extensive calcification in PXE. Financial Disclosures: Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

4.
J Patient Saf ; 20(4): 299-305, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38240645

RESUMO

OBJECTIVES: Variability in opioid-prescribing practices after common pediatric surgical procedures at our institution prompted the development of opioid-prescribing guidelines that provided suggested dose limitations for narcotics. The aims of this study were to improve opioid prescription practices through implementation of the developed guidelines and to assess compliance and identify barriers preventing guideline utilization. METHODS: We conducted a single-center cohort study of all children who underwent the most common outpatient general surgery procedures at our institution from August 1, 2018, to February 1, 2020. We created guidelines designed to limit opioid prescription doses based on data obtained from standardized postoperative telephone interviews. Three 6-month periods were evaluated: before guideline implementation, after guideline initiation, and after addressing barriers to guideline compliance. Targeted interventions to increase compliance included modification of electronic medical record defaults and provider educations. Differences in opioid weight-based doses prescribed, filled, and taken, as well as protocol adherence between the 3 timeframes were evaluated. RESULTS: A total of 1033 children underwent an outpatient procedure during the 1.5-year time frame. Phone call response rate was 72.22%. There was a significant sustained decrease in opioid doses prescribed ( P < 0.0001), prescriptions filled ( P = 0.009), and opioid doses taken ( P = 0.001) after implementation, without subsequent increase in reported pain on postoperative phone call ( P = 0.96). Protocol compliance significantly improved (62.39% versus 83.98%, P < 0.0001) after obstacles were addressed. CONCLUSIONS: Implementation of a protocol limiting opioid prescribing after frequently performed pediatric general surgery procedures reduced opioids prescribed and taken postoperatively. Interventions that addressed barriers to application led to increased protocol compliance and sustained decreases in opioids prescribed and taken without a deleterious effect on pain control.


Assuntos
Analgésicos Opioides , Fidelidade a Diretrizes , Hospitais Pediátricos , Dor Pós-Operatória , Padrões de Prática Médica , Humanos , Analgésicos Opioides/uso terapêutico , Analgésicos Opioides/administração & dosagem , Dor Pós-Operatória/tratamento farmacológico , Dor Pós-Operatória/prevenção & controle , Criança , Masculino , Padrões de Prática Médica/normas , Padrões de Prática Médica/estatística & dados numéricos , Feminino , Fidelidade a Diretrizes/estatística & dados numéricos , Pré-Escolar , Estudos de Coortes , Lactente , Guias de Prática Clínica como Assunto , Adolescente , Prescrições de Medicamentos/normas , Prescrições de Medicamentos/estatística & dados numéricos
5.
J Mol Cell Cardiol ; 180: 44-57, 2023 07.
Artigo em Inglês | MEDLINE | ID: mdl-37127261

RESUMO

We compared commonly used BAPTA-derived chemical Ca2+ dyes (fura2, Fluo-4, and Rhod-2) with a newer genetically encoded indicator (R-GECO) in single cell models of the heart. We assessed their performance and effects on cardiomyocyte contractility, determining fluorescent signal-to-noise ratios and sarcomere shortening in primary ventricular myocytes from adult mouse and guinea pig, and in human iPSC-derived cardiomyocytes. Chemical Ca2+ dyes displayed dose-dependent contractile impairment in all cell types, and we observed a negative correlation between contraction and fluorescence signal-to-noise ratio, particularly for fura2 and Fluo-4. R-GECO had no effect on sarcomere shortening. BAPTA-based dyes, but not R-GECO, inhibited in vitro acto-myosin ATPase activity. The presence of fura2 accentuated or diminished changes in contractility and Ca2+ handling caused by small molecule modulators of contractility and intracellular ionic homeostasis (mavacamten, levosimendan, and flecainide), but this was not observed when using R-GECO in adult guinea pig left ventricular cardiomyocytes. Ca2+ handling studies are necessary for cardiotoxicity assessments of small molecules intended for clinical use. Caution should be exercised when interpreting small molecule studies assessing contractile effects and Ca2+ transients derived from BAPTA-like chemical Ca2+ dyes in cellular assays, a common platform for cardiac toxicology testing and mechanistic investigation of cardiac disease physiology and treatment.


Assuntos
Células-Tronco Pluripotentes Induzidas , Miócitos Cardíacos , Animais , Cobaias , Humanos , Camundongos , Cálcio/metabolismo , Corantes/metabolismo , Corantes/farmacologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Contração Miocárdica , Miócitos Cardíacos/metabolismo , Suínos
6.
Am Surg ; 89(6): 2934-2936, 2023 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35435006

RESUMO

Blue Rubber Bleb Nevus Syndrome is a congenital rarity that manifests as vascular malformations throughout the body, including the gastrointestinal tract. With fewer than 300 cases reported, the etiology and clinical course is poorly understood; however, the literature suggests TEK mutations on chromosome 9 result in unregulated angiogenesis. We present the case of a young female treated for anemia of unknown etiology who presented in hemorrhagic shock due to gastrointestinal hemorrhage necessitating small bowel resection, with cutaneous, intestinal, hepatic, and lingual vascular malformations associated with a single somatic pathologic TEK mutation. Although uncommon, this case suggests that Blue Rubber Bleb Nevus Syndrome should be considered in the differential of a patient with persistent anemia and cutaneous lesions, carrying the potential for multiple gastrointestinal vascular malformations progressing to hemorrhage necessitating operative management. Additionally, a severe phenotype can occur without a double-hit TEK mutation.


Assuntos
Neoplasias Gastrointestinais , Nevo Azul , Neoplasias Cutâneas , Malformações Vasculares , Feminino , Humanos , Nevo Azul/complicações , Nevo Azul/diagnóstico , Nevo Azul/genética , Neoplasias Gastrointestinais/complicações , Neoplasias Gastrointestinais/cirurgia , Neoplasias Cutâneas/complicações , Neoplasias Cutâneas/cirurgia , Malformações Vasculares/complicações , Malformações Vasculares/diagnóstico , Malformações Vasculares/cirurgia , Hemorragia Gastrointestinal/cirurgia , Hemorragia Gastrointestinal/complicações
7.
Am Surg ; 89(11): 4310-4315, 2023 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35715017

RESUMO

INTRODUCTION: Sepsis prevention pathways, which often include blood and urine cultures, are common in children's hospitals. Fever and tachycardia, signs often seen in patients with appendicitis, frequently trigger these pathways. We hypothesized that cultures were frequently obtained in children with appendicitis. MATERIALS AND METHODS: We conducted a single-center retrospective cohort study evaluating children with image-confirmed appendicitis from 4/1/2019 to 10/1/2020, coinciding with the initiation of sepsis prevention pathways. Factors associated with culture acquisition, as well as culture results, treatment, and outcomes were evaluated. RESULTS: Six hundred and fifty eight children presented with acute appendicitis during the 1.5-year period, with a median age of 10.67 years (interquartile range (IQR) 8.17-14.08). Cultures were obtained in 22.9%, including blood culture (BCx) in 8.1% and urine culture (UCx) in 17.9%. Culture acquisition decreased by 17.6% after sepsis protocol initiation. Blood culture acquisition correlated with fever (P = .003) and younger age (P = .03), whereas the attainment of BCx and UCx was associated with female sex (P = .04, P < .0001), complicated appendicitis (P = .0001, P = .03), and unknown diagnosis (P < .0001, P < .0001). There were five positive UCx (4.24%); however, all remained asymptomatic despite a short antibiotic duration dictated by institutional appendicitis protocol. The one positive BCx (1.89%) was suspected contamination and not treated. DISCUSSION: The findings of this cohort suggest a low incidence of positive culture as well as lack of impact on clinical management in image-proven appendicitis and the initiation of a sepsis bundle without automatic culture acquisition may result in decreased culture attainment.


Assuntos
Apendicite , Sepse , Humanos , Criança , Feminino , Apendicite/complicações , Apendicite/diagnóstico , Apendicite/cirurgia , Estudos Retrospectivos , Apendicectomia , Sepse/diagnóstico , Sepse/etiologia , Incidência , Febre/etiologia
8.
Am J Surg ; 224(6): 1445-1449, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36058750

RESUMO

BACKGROUND: While it is assumed adolescents receive comparable trauma care at pediatric trauma centers (PTC), adult trauma centers (ATC), and combined facilities (MTC), this remains understudied. METHODS: We conducted a retrospective cohort study through the NTDB evaluating patients 14-18 years of age who presented to an ACS-verified level 1 or 2 trauma facility between 1/1/2016 and 12/31/2019. Multiple logistic regression analyses were performed to compare mortality risk among trauma facility verification types. RESULTS: 91,881 adolescents presented after trauma over the four-years. Hypotension, severe TBI, firearm mechanism, and ISS >15 were associated with increased mortality. Compared to PTCs, the odds of trauma-related mortality were statistically higher at MTCs (OR 1.82, p = 0.004) and ATCs (OR 1.89-2.05, p = 0.001-0.002). CONCLUSIONS: Injured adolescents receiving care at ATCs and MTCs have higher mortality risk than those cared for at PTCs. Further evaluation of factors associated with this observed difference is warranted and may help identify opportunities to improve outcomes in injured adolescents.


Assuntos
Experiências Adversas da Infância , Armas de Fogo , Adolescente , Criança , Humanos , Adulto Jovem , Escala de Gravidade do Ferimento , Estudos Retrospectivos , Centros de Traumatologia
9.
Elife ; 112022 03 14.
Artigo em Inglês | MEDLINE | ID: mdl-35285796

RESUMO

Anatomical and physiological compartmentalization of neurons is a mechanism to increase the computational capacity of a circuit, and a major question is what role axonal compartmentalization plays. Axonal compartmentalization may enable localized, presynaptic plasticity to alter neuronal output in a flexible, experience-dependent manner. Here, we show that olfactory learning generates compartmentalized, bidirectional plasticity of acetylcholine release that varies across the longitudinal compartments of Drosophila mushroom body (MB) axons. The directionality of the learning-induced plasticity depends on the valence of the learning event (aversive vs. appetitive), varies linearly across proximal to distal compartments following appetitive conditioning, and correlates with learning-induced changes in downstream mushroom body output neurons (MBONs) that modulate behavioral action selection. Potentiation of acetylcholine release was dependent on the CaV2.1 calcium channel subunit cacophony. In addition, contrast between the positive conditioned stimulus and other odors required the inositol triphosphate receptor, which maintained responsivity to odors upon repeated presentations, preventing adaptation. Downstream from the MB, a set of MBONs that receive their input from the γ3 MB compartment were required for normal appetitive learning, suggesting that they represent a key node through which reward learning influences decision-making. These data demonstrate that learning drives valence-correlated, compartmentalized, bidirectional potentiation, and depression of synaptic neurotransmitter release, which rely on distinct mechanisms and are distributed across axonal compartments in a learning circuit.


Assuntos
Acetilcolina , Olfato , Animais , Axônios , Drosophila/fisiologia , Drosophila melanogaster , Corpos Pedunculados/fisiologia , Plasticidade Neuronal/fisiologia , Neurotransmissores , Olfato/fisiologia
10.
J Am Chem Soc ; 144(3): 1332-1341, 2022 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-35037457

RESUMO

The mature skeletons of hard corals, termed stony or scleractinian corals, are made of aragonite (CaCO3). During their formation, particles attaching to the skeleton's growing surface are calcium carbonate, transiently amorphous. Here we show that amorphous particles are observed frequently and reproducibly just outside the skeleton, where a calicoblastic cell layer envelops and deposits the forming skeleton. The observation of particles in these locations, therefore, is consistent with nucleation and growth of particles in intracellular vesicles. The observed extraskeletal particles range in size between 0.2 and 1.0 µm and contain more of the amorphous precursor phases than the skeleton surface or bulk, where they gradually crystallize to aragonite. This observation was repeated in three diverse genera of corals, Acropora sp., Stylophora pistillata─differently sensitive to ocean acidification (OA)─and Turbinaria peltata, demonstrating that intracellular particles are a major source of material during the additive manufacturing of coral skeletons. Thus, particles are formed away from seawater, in a presumed intracellular calcifying fluid (ICF) in closed vesicles and not, as previously assumed, in the extracellular calcifying fluid (ECF), which, unlike ICF, is partly open to seawater. After particle attachment, the growing skeleton surface remains exposed to ECF, and, remarkably, its crystallization rate varies significantly across genera. The skeleton surface layers containing amorphous pixels vary in thickness across genera: ∼2.1 µm in Acropora, 1.1 µm in Stylophora, and 0.9 µm in Turbinaria. Thus, the slow-crystallizing Acropora skeleton surface remains amorphous and soluble longer, including overnight, when the pH in the ECF drops. Increased skeleton surface solubility is consistent with Acropora's vulnerability to OA, whereas the Stylophora skeleton surface layer crystallizes faster, consistent with Stylophora's resilience to OA. Turbinaria, whose response to OA has not yet been tested, is expected to be even more resilient than Stylophora, based on the present data.


Assuntos
Concentração de Íons de Hidrogênio
11.
Mol Syst Des Eng ; 7(11): 1415-1421, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-37927331

RESUMO

Herein, we report the crystal structure of 2,7-dichlorofluorescein methyl ester (DCF-ME) and its fluorescence response to hydroxyapatite binding. The reported fluorophore is very selective for staining the bone matrix and provides turn-on fluorescence upon hydroxyapatite binding. The reported fluorophore can readily pass the cell membrane of the C2C12 cell line, and it is non-toxic for the cell line. The reported fluorophore DCF-ME may find applications in monitoring bone remodeling and microcalcification as an early diagnosis tool for breast cancer and age-related macular degeneration.

12.
BMC Cancer ; 21(1): 1061, 2021 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-34565342

RESUMO

BACKGROUND: Neuroblastoma (NB) patients with MYCN amplification or overexpression respond poorly to current therapies and exhibit extremely poor clinical outcomes. PI3K-mTOR signaling-driven deregulation of protein synthesis is very common in NB and various other cancers that promote MYCN stabilization. In addition, both the MYCN and mTOR signaling axes can directly regulate a common translation pathway that leads to increased protein synthesis and cell proliferation. However, a strategy of concurrently targeting MYCN and mTOR signaling in NB remains unexplored. This study aimed to investigate the therapeutic potential of targeting dysregulated protein synthesis pathways by inhibiting the MYCN and mTOR pathways together in NB. METHODS: Using small molecule/pharmacologic approaches, we evaluated the effects of combined inhibition of MYCN transcription and mTOR signaling on NB cell growth/survival and associated molecular mechanism(s) in NB cell lines. We used two well-established BET (bromodomain extra-terminal) protein inhibitors (JQ1, OTX-015), and a clinically relevant mTOR inhibitor, temsirolimus, to target MYCN transcription and mTOR signaling, respectively. The single agent and combined efficacies of these inhibitors on NB cell growth, apoptosis, cell cycle and neurospheres were assessed using MTT, Annexin-V, propidium-iodide staining and sphere assays, respectively. Effects of inhibitors on global protein synthesis were quantified using a fluorescence-based (FamAzide)-based protein synthesis assay. Further, we investigated the specificities of these inhibitors in targeting the associated pathways/molecules using western blot analyses. RESULTS: Co-treatment of JQ1 or OTX-015 with temsirolimus synergistically suppressed NB cell growth/survival by inducing G1 cell cycle arrest and apoptosis with greatest efficacy in MYCN-amplified NB cells. Mechanistically, the co-treatment of JQ1 or OTX-015 with temsirolimus significantly downregulated the expression levels of phosphorylated 4EBP1/p70-S6K/eIF4E (mTOR components) and BRD4 (BET protein)/MYCN proteins. Further, this combination significantly inhibited global protein synthesis, compared to single agents. Our findings also demonstrated that both JQ1 and temsirolimus chemosensitized NB cells when tested in combination with cisplatin chemotherapy. CONCLUSIONS: Together, our findings demonstrate synergistic efficacy of JQ1 or OTX-015 and temsirolimus against MYCN-driven NB, by dual-inhibition of MYCN (targeting transcription) and mTOR (targeting translation). Additional preclinical evaluation is warranted to determine the clinical utility of targeted therapy for high-risk NB patients.


Assuntos
Acetanilidas/farmacologia , Azepinas/farmacologia , Compostos Heterocíclicos com 3 Anéis/farmacologia , Proteína Proto-Oncogênica N-Myc/antagonistas & inibidores , Neuroblastoma/tratamento farmacológico , Sirolimo/análogos & derivados , Serina-Treonina Quinases TOR/antagonistas & inibidores , Triazóis/farmacologia , Proteínas Adaptadoras de Transdução de Sinal/efeitos dos fármacos , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Proteínas de Ciclo Celular/efeitos dos fármacos , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cisplatino/farmacologia , Regulação para Baixo , Sinergismo Farmacológico , Fator de Iniciação 4E em Eucariotos/efeitos dos fármacos , Fator de Iniciação 4E em Eucariotos/metabolismo , Pontos de Checagem da Fase G1 do Ciclo Celular/efeitos dos fármacos , Humanos , Proteína Proto-Oncogênica N-Myc/metabolismo , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Proteínas Quinases S6 Ribossômicas 70-kDa/efeitos dos fármacos , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Transdução de Sinais , Sirolimo/farmacologia , Esferoides Celulares/efeitos dos fármacos , Serina-Treonina Quinases TOR/metabolismo , Fatores de Transcrição/efeitos dos fármacos , Fatores de Transcrição/metabolismo
13.
Oecologia ; 197(3): 577-588, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34546496

RESUMO

The composition of plant-pollinator interactions-i.e., who interacts with whom in diverse communities-is highly dynamic, and we have a very limited understanding of how interaction identities change in response to perturbations in nature. One prediction from niche and diet theory is that resource niches will broaden to compensate for resource reductions driven by perturbations, yet this has not been empirically tested in plant-pollinator systems in response to real-world perturbations in the field. Here, we use a long-term dataset of floral visitation to Ipomopsis aggregata, a montane perennial herb, to test whether the breadth of its floral visitation niche (i.e., flower visitor richness) changed in response to naturally occurring drought perturbations. Fewer floral resources are available in drought years, which could drive pollinators to expand their foraging niches, thereby expanding plants' floral visitation niches. We compared two drought years to three non-drought years to analyze changes in niche breadth and community composition of floral visitors to I. aggregata, predicting broadened niche breadth and distinct visitor community composition in drought years compared to non-drought years. We found statistically significant increases in niche breadth in drought years as compared to non-drought conditions, but no statistically distinguishable changes in community composition of flower visitors. Our findings suggest that plants' floral visitation niches may exhibit considerable plasticity in response to disturbance. This may have widespread consequences for community-level stability as well as functional consequences if increased niche overlap affects pollination services.


Assuntos
Secas , Polinização , Flores , Plantas
14.
Sci Rep ; 11(1): 13098, 2021 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-34162943

RESUMO

In order to behave appropriately in a rapidly changing world, individuals must be able to detect when changes occur in that environment. However, at any given moment, there are a multitude of potential changes of behavioral significance that could occur. Here we investigate how knowledge about the space of possible changes affects human change point detection. We used a stochastic auditory change point detection task that allowed model-free and model-based characterization of the decision process people employ. We found that subjects can simultaneously apply distinct timescales of evidence evaluation to the same stream of evidence when there are multiple types of changes possible. Informative cues that specified the nature of the change led to improved accuracy for change point detection through mechanisms involving both the timescales of evidence evaluation and adjustments of decision bounds. These results establish three important capacities of information processing for decision making that any proposed neural mechanism of evidence evaluation must be able to support: the ability to simultaneously employ multiple timescales of evidence evaluation, the ability to rapidly adjust those timescales, and the ability to modify the amount of information required to make a decision in the context of flexible timescales.

15.
Proc Natl Acad Sci U S A ; 118(26)2021 06 29.
Artigo em Inglês | MEDLINE | ID: mdl-34162704

RESUMO

Biodiversity losses are a major driver of global changes in ecosystem functioning. While most studies of the relationship between biodiversity and ecosystem functioning have examined randomized species losses, trait-based filtering associated with species-specific vulnerability to drivers of diversity loss can strongly influence how ecosystem functioning responds to declining biodiversity. Moreover, the responses of ecosystem functioning to diversity loss may be mediated by environmental variability interacting with the suite of traits remaining in depauperate communities. We do not yet understand how communities resulting from realistic diversity losses (filtered by response traits) influence ecosystem functioning (via effect traits of the remaining community), especially under variable environmental conditions. Here, we directly test how realistic and randomized plant diversity losses influence productivity and invasion resistance across multiple years in a California grassland. Compared with communities based on randomized diversity losses, communities resulting from realistic (drought-driven) species losses had higher invasion resistance under climatic conditions that matched the trait-based filtering they experienced. However, productivity declined more with realistic than with randomized species losses across all years, regardless of climatic conditions. Functional response traits aligned with effect traits for productivity but not for invasion resistance. Our findings illustrate that the effects of biodiversity losses depend not only on the identities of lost species but also on how the traits of remaining species interact with varying environmental conditions. Understanding the consequences of biodiversity change requires studies that evaluate trait-mediated effects of species losses and incorporate the increasingly variable climatic conditions that future communities are expected to experience.


Assuntos
Biodiversidade , Biomassa , California , Análise de Componente Principal , Especificidade da Espécie
16.
JASA Express Lett ; 1(5): 053201, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-36154113

RESUMO

This study offers a metric to investigate transition times between articulated notes for reed instruments such as clarinets and bass clarinets. The method requires analysis of measurements of musician mouthpiece pressure. For this paper, the data were recorded using sensor-equipped mouthpieces made for the clarinet and bass clarinet. The method leads to a metric called the transition time (ΔT), which allows for comparing duration measured between notes for clarinets played in different musical contexts (dynamics, tempos, etc.) and playing regimes and between players.


Assuntos
Bass , Música , Animais
17.
Br J Oral Maxillofac Surg ; 58(9): e16-e24, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32800608

RESUMO

Coronectomy is an alternative surgical technique for the management of high-risk third molars. It involves the removal of the crown of a tooth and the deliberate retention of the roots, thereby avoiding injury to the inferior alveolar nerve (IAN). Previous studies have suggested that it reduces the risk of nerve injury when compared with surgical extraction. The purpose of this study was to systematically review the incidence of complications following coronectomy such as IAN injury, pain, dry socket, infection, root migration, and need for re-operation. A comparative cost analysis of coronectomy and surgical extraction was done based on the results of the review. This provides an insight into the economic implications of the two procedures. A search through the MEDLINE database via Ovid, PubMed, Scopus, EMBASE via Ovid, and Web of Science, was carried out to extract randomised and non-randomised controlled trials. Four studies fulfilled the inclusion criteria. A meta-analysis was conducted to measure the overall effect of each outcome. The pooled odds ratio (OR) for IAN injury was 0.16 (95% CI 0.01 to 0.39). Coronectomy reduced this risk by 84%. Dry socket may occur less frequently following coronectomy whereas infection did not show a higher incidence with either intervention. Root migration was found to occur in 13%-85% of cases and the average incidence of re-operation was 2.2%. The ratio of the average costs was 1.12 favouring coronectomy if cone-beam computed tomography (CBCT) was not done prior to the procedure. If a scan was taken routinely for coronectomy, the cost ratio marginally favoured extraction. Coronectomy reduced the risk of nerve injury in high-risk third molars. Definitive conclusions, however, cannot be made for outcomes such as the need for re-operation, which may alter the cost ratio of coronectomy:extraction, as higher quality studies with longer follow-up are needed.


Assuntos
Coroa do Dente , Dente Impactado , Traumatismos do Nervo Trigêmeo , Árvores de Decisões , Humanos , Mandíbula , Nervo Mandibular , Dente Serotino/cirurgia , Coroa do Dente/cirurgia , Extração Dentária/efeitos adversos , Dente Impactado/cirurgia
18.
Mol Cancer Ther ; 19(6): 1351-1362, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32371591

RESUMO

The MYC oncogene is frequently amplified in patients with medulloblastoma, particularly in group 3 patients, who have the worst prognosis. mTOR signaling-driven deregulated protein synthesis is very common in various cancers, including medulloblastoma, that can promote MYC stabilization. As a transcription factor, MYC itself is further known to regulate transcription of several components of protein synthesis machinery, leading to an enhanced protein synthesis rate and proliferation. Thus, inhibiting enhanced protein synthesis by targeting the MYC and mTOR pathways together may represent a highly relevant strategy for the treatment of MYC-driven medulloblastoma. Here, using siRNA and small-molecule inhibitor approaches, we evaluated the effects of combined inhibition of MYC transcription and mTOR signaling on medulloblastoma cell growth/survival and associated molecular mechanism(s) in MYC-amplified (group 3) medulloblastoma cell lines and xenografts. Combined inhibition of MYC and mTOR synergistically suppressed medulloblastoma cell growth and induced G1 cell-cycle arrest and apoptosis. Mechanistically, the combined inhibition significantly downregulated the expression levels of key target proteins of MYC and mTOR signaling. Our results with RNA-sequencing revealed that combined inhibition synergistically modulated global gene expression including MYC/mTOR components. In addition, the combination treatment significantly delayed tumor growth and prolonged survival of MYC-amplified medulloblastoma xenografted mice by downregulating expression of MYC and the key downstream components of mTOR signaling, compared with single-agent therapy. Together, our findings demonstrated that dual inhibition of MYC (transcription) and mTOR (translation) of the protein synthesis pathway can be a novel therapeutic approach against MYC-driven medulloblastoma.


Assuntos
Azepinas/farmacologia , Neoplasias Cerebelares/tratamento farmacológico , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Imidazóis/farmacologia , Meduloblastoma/tratamento farmacológico , Biossíntese de Proteínas/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-myc/metabolismo , Quinolinas/farmacologia , Triazóis/farmacologia , Animais , Antineoplásicos/farmacologia , Apoptose , Ciclo Celular , Proliferação de Células , Neoplasias Cerebelares/metabolismo , Neoplasias Cerebelares/patologia , Feminino , Humanos , Meduloblastoma/metabolismo , Meduloblastoma/patologia , Camundongos , Camundongos Endogâmicos NOD , Camundongos SCID , Proteínas Proto-Oncogênicas c-myc/genética , Serina-Treonina Quinases TOR/antagonistas & inibidores , Células Tumorais Cultivadas , Ensaios Antitumorais Modelo de Xenoenxerto
19.
Public Health ; 180: 136-140, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31901574

RESUMO

OBJECTIVES: To investigate patient demographics and venue type preferences within community settings associated with re-attendance for chlamydia testing. STUDY DESIGN: Data used for this analysis were obtained from the English National Chlamydia Screening Programme (NCSP) which focuses on prevention, control and treatment of chlamydia in sexually active under-25 year olds. A greater understanding of how young adults attend services helps to inform commissioners regarding where to focus resources within community settings. METHODS: Data from the Chlamydia surveillance system (CTAD) were used to count patient attendances at non-specialist sexual health services (SHSs) among 15-24-year-olds and monitor re-attendance for chlamydia testing within and between community services between 6 and 18 months of their first visit. RESULTS: From January 2013 to December 2016, 866,847 young people underwent 1,041,245 tests for chlamydia. Re-attendance for chlamydia testing was 20.1% (174,398/866,847). Re-attendance rate was 28.5% after a positive test and 19.5% after a negative test. For re-attenders, 64.2% used the same venue type for both visits. General practice (GP) and sexual and reproductive health services (SRH) were the most commonly re-attended services (31.0% and 30.6% respectively). CONCLUSIONS: Only one in five re-attended for chlamydia testing. Re-attendance was associated with having a positive result, accessibility and convenience. Patients are likely to return for testing to services they know. This should be considered by commissioners implementing new re-attendance guidance based on the NCSP.


Assuntos
Infecções por Chlamydia/prevenção & controle , Serviços de Saúde Comunitária/estatística & dados numéricos , Utilização de Instalações e Serviços/estatística & dados numéricos , Programas de Rastreamento/estatística & dados numéricos , Adolescente , Infecções por Chlamydia/epidemiologia , Inglaterra/epidemiologia , Feminino , Medicina Geral/estatística & dados numéricos , Humanos , Masculino , Programas Nacionais de Saúde , Serviços de Saúde Reprodutiva/estatística & dados numéricos , Adulto Jovem
20.
J Phys Chem B ; 123(18): 4108-4117, 2019 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-30998844

RESUMO

Stable glasses are formed during physical vapor deposition (PVD), through the surface-mediated equilibration process. Understanding surface relaxation dynamics is important in understanding the details of this process. Direct measurements of the surface relaxation times in molecular glass systems are challenging. As such, surface diffusion measurements have been used in the past as a proxy for the surface relaxation process. In this study, we show that the absence of enhanced surface diffusion is not a reliable predictor of reduced ability to produce stable glasses. To demonstrate, we have prepared stable glasses (SGs) from two structurally similar organic molecules, 1,3-bis(1-naphthyl)-5-(2-naphthyl)benzene (TNB) and 9-(3,5-di(naphthalen-1-yl)phenyl)anthracene (α,α-A), with similar density increase and improved kinetic stability as compared to their liquid-quenched (LQ) counterparts. The surface diffusion values of these glasses were measured both in the LQ and SG states below their glass transition temperatures ( Tgs) using gold nanorod probes. While TNB shows enhanced surface diffusion in both SG and LQ states, no significant surface Tg diffusion is observed on the surface of α,α-A within our experimental time scales. However, isothermal dewetting experiments on ultrathin films of both molecules below Tg indicate the existence of enhanced dynamics in ultrathin films for both molecules, indirectly showing the existence of an enhanced mobile surface layer. Both films produce stable glasses, which is another indication for the existence of the mobile surface layer. Our results suggest that lateral surface diffusion may not be a good proxy for enhanced surface relaxation dynamics required to produce stable glasses, and thus, other types of measurements to directly probe the surface relaxation times may be necessary.

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