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1.
J Sex Marital Ther ; 50(4): 527-541, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38567544

RESUMEN

This study examines dyadic data from 299 married and 242 cohabiting Black heterosexual couples in the United States (an understudied cross-section of the population) and assesses individual (actor) effects as well as couple (partner) effects of sexual sanctification and relationship satisfaction. Higher levels of sexual sanctification were associated with higher levels of relationship satisfaction for women and men in the actor effects, but no significant associations were found in the partner effects for couples. Additionally, initial findings suggest that sexual sanctification may act as a relational protective factor for Black married and cohabiting couples. Implications for further research as well as practical applications for clergy, therapists, and practitioners working with Black heterosexual couples in sexual relationships are also discussed.


Asunto(s)
Negro o Afroamericano , Heterosexualidad , Satisfacción Personal , Parejas Sexuales , Humanos , Masculino , Femenino , Heterosexualidad/psicología , Adulto , Negro o Afroamericano/psicología , Parejas Sexuales/psicología , Estados Unidos , Relaciones Interpersonales , Conducta Sexual/psicología , Persona de Mediana Edad , Esposos/psicología , Matrimonio/psicología
2.
J Clin Child Adolesc Psychol ; : 1-15, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38530356

RESUMEN

OBJECTIVE: Current antibullying programs can reduce overall rates of victimization but appear to overlook processes that give rise to persistent peer victimization. Needed are studies that delineate the interplay between social contextual and individual difference variables that contribute to persistent peer victimization. We examined the extent to which two individual-difference variables - internalizing symptoms (IS) and anxiety sensitivity (AS) - moderated the link between children's average social preference score across the school year and their status as persistent victims. METHOD: Participants included 659 4th-grade students (Mage = 9.31 years, SD = 0.50, 51.8% girls; 42.3% Latinx, 28.9% non-Hispanic White, 10.2% Pacific Islander, 7.7% Bi/Multiracial, 1.9% Black, 1.7% Asian, 1.7% Native American, and 3.4% unreported) from 10 public elementary schools in the U.S. RESULTS: As expected, higher social preference scores predicted a decreased likelihood of being persistently victimized. Conversely, IS and AS were positively linked to persistent victim status. AS significantly moderated the link between social preference and persistent victim status such that for children with high AS, compared to those with AS scores at or below the mean, the negative association between social preference and persistent victim status was attenuated. CONCLUSIONS: Findings provide evidence that children who experience high levels of IS and AS are at risk for being persistently victimized by peers and that high AS could signal increased risk for persistent victimization even when children are generally liked by peers. We discuss the implications of these findings for efforts to develop focused interventions for chronically bullied children.

3.
J Intellect Disabil Res ; 68(4): 369-376, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38229473

RESUMEN

BACKGROUND: Neurocognitive functioning is an integral phenotype of 22q11.2 deletion syndrome relating to severity of psychopathology and outcomes. A neurocognitive battery that could be administered remotely to assess multiple cognitive domains would be especially beneficial to research on rare genetic variants, where in-person assessment can be unavailable or burdensome. The current study compares in-person and remote assessments of the Penn computerised neurocognitive battery (CNB). METHODS: Participants (mean age = 17.82, SD = 6.94 years; 48% female) completed the CNB either in-person at a laboratory (n = 222) or remotely (n = 162). RESULTS: Results show that accuracy of CNB performance was equivalent across the two testing locations, while slight differences in speed were detected in 3 of the 11 tasks. CONCLUSIONS: These findings suggest that the CNB can be used in remote settings to assess multiple neurocognitive domains.


Asunto(s)
Síndrome de DiGeorge , Humanos , Femenino , Adolescente , Masculino , Síndrome de DiGeorge/complicaciones , Síndrome de DiGeorge/psicología , Cognición , Pruebas Neuropsicológicas , Psicopatología , Fenotipo
4.
Photosynth Res ; 2023 Nov 01.
Artículo en Inglés | MEDLINE | ID: mdl-37910331

RESUMEN

Hybrid complexes incorporating synthetic Mn-porphyrins into an artificial four-helix bundle domain of bacterial reaction centers created a system to investigate new electron transfer pathways. The reactions were initiated by illumination of the bacterial reaction centers, whose primary photochemistry involves electron transfer from the bacteriochlorophyll dimer through a series of electron acceptors to the quinone electron acceptors. Porphyrins with diphenyl, dimesityl, or fluorinated substituents were synthesized containing either Mn or Zn. Electrochemical measurements revealed potentials for Mn(III)/Mn(II) transitions that are ~ 0.4 V higher for the fluorinated Mn-porphyrins than the diphenyl and dimesityl Mn-porphyrins. The synthetic porphyrins were introduced into the proteins by binding to a four-helix bundle domain that was genetically fused to the reaction center. Light excitation of the bacteriochlorophyll dimer of the reaction center resulted in new derivative signals, in the 400 to 450 nm region of light-minus-dark spectra, that are consistent with oxidation of the fluorinated Mn(II) porphyrins and reduction of the diphenyl and dimesityl Mn(III) porphyrins. These features recovered in the dark and were not observed in the Zn(II) porphyrins. The amplitudes of the signals were dependent upon the oxidation/reduction midpoint potentials of the bacteriochlorophyll dimer. These results are interpreted as photo-induced charge-separation processes resulting in redox changes of the Mn-porphyrins, demonstrating the utility of the hybrid artificial reaction center system to establish design guidelines for novel electron transfer reactions.

5.
Diabet Med ; 40(4): e15035, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36576331

RESUMEN

AIMS: Facilitated self-management support programmes have become central to the treatment of chronic diseases including diabetes. For many children and young people with diabetes (CYPD), the impact on glycated haemoglobin (HbA1c ) and a range of self-management behaviours promised by these programmes remain unrealised. This warrants an appraisal of current thinking and the existing evidence to guide the development of programmes better targeted at this age group. METHODS: Create a narrative review of systematic reviews produced in the last 3 years that have explored the impact on CYPD of the four key elements of self-management support programmes: education, instruction and advice including peer support; psychological counselling via a range of therapies; self-monitoring, including diaries and telemetric devices; and telecare, the technology-enabled follow-up and support by healthcare providers. RESULTS: Games and gamification appear to offer a promising means of engaging and educating CYPD. Psychological interventions when delivered by trained practitioners, appear to improve HbA1c and quality of life although effect sizes were small. Technology-enabled interactive diaries can increase the frequency of self-monitoring and reduce levels of HbA1c . Telecare provided synchronously via telephone produced significant improvements in HbA1c . CONCLUSIONS: The cost-effective flexibility of increasing the reliance on technology is an attractive proposition; however, there are resource implications for digital connectivity in underserved populations. The need remains to improve the understanding of which elements of each component are most effective in a particular context, and how to optimise the influence and input of families, caregivers and peers.


Asunto(s)
Diabetes Mellitus , Automanejo , Humanos , Niño , Adolescente , Calidad de Vida , Revisiones Sistemáticas como Asunto , Teléfono
6.
J Prev Alzheimers Dis ; 9(4): 672-678, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36281671

RESUMEN

Alzheimer's disease and related dementias (ADRD) is two times more prevalent among compared to non-Hispanic Whites. Despite the higher prevalence of ADRD among older African Americans, recent estimates suggest research enrollment by those who identify as African American remains limited. The purpose of the study is to 1) explore how a culturally tailored community education program impacts clinical trial interest and enrollment in ADRD research studies and to 2) identify how applicable the African American community perceived the culturally tailored curriculum. Using a community-engaged research approach, we collaborated with predominately African American serving community-based organizations to support content development and delivery of Aging with Grace (AWG), a culturally tailored ADRD educational curriculum. A total of five AWG presentations were given to 66 attendees. Most attendees (67%) expressed interest in participating in clinical trials after attending AWG. Enrollment increased within an observational study (84%) and lifestyle prevention clinical trials (52%) from 2018 to 2019. Attendees (32%) also perceived an increase in ADRD knowledge from attending AWG and 89.1% believed more African Americans should participate in research. Our work demonstrates the effectiveness of a culturally tailored community education program to enhance knowledge, clinical trial interest, and recruitment into observational studies and lifestyle ADRD clinical trials among older African Americans. Education programs developed in partnership with the community can serve as bridge to research participation for underrepresented minorities in clinical research. Future studies should assess long-term retention of knowledge and research readiness.


Asunto(s)
Enfermedad de Alzheimer , Negro o Afroamericano , Humanos , Educación en Salud , Proyectos de Investigación
7.
AIDS Res Hum Retroviruses ; 38(9): 735-742, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35778856

RESUMEN

Hypertension (HTN) is a common comorbidity among people with HIV and associated with an increased risk for atherosclerotic cardiovascular disease and chronic kidney disease. The relationship of antiretroviral therapy (ART) initiation to incident HTN remains a clinical question. We determined HTN incidence at 48 weeks of follow-up among ART-naive participants without HTN and not taking antihypertensive medications at ART initiation through randomized clinical trials through the AIDS Clinical Trial Group between 1999 and 2011. We assessed the association of baseline characteristics, including randomized ART agents with HTN incidence at 48 weeks using Poisson regression models. Incident HTN was defined as blood pressure ≥130/80 mmHg, or use of antihypertensive medication. Among 2,614 participants, mean age was 37 ± 10 years, 79% male sex, and 36% African American race. After 48 weeks, 839 participants (32%) developed HTN. Receiving a non-nucleoside reverse transcriptase inhibitor (NNRTI) was associated with an increased relative risk (RR) of incident HTN, while the risk was lower for protease inhibitor use. Stavudine and efavirenz were associated with an increased RR of developing HTN, while tenofovir disoproxil fumarate, darunavir/ritonavir, and atazanavir/ritonavir were associated with a decreased risk of developing HTN. Additionally, older age, higher body mass index (BMI), and having hepatitis C were associated with an increased risk for developing HTN, while women and participants with a higher baseline CD4 count were at a decreased risk of developing HTN at 48 weeks. One third of these ART naive participants developed HTN after ART initiation. NNRTIs, notably efavirenz, and stavudine were associated with an increased risk of HTN. Additional factors associated with HTN included traditional factors like older age and higher BMI, and advanced HIV disease (lower CD4 count). (Clinicaltrials.gov: NCT00001137).


Asunto(s)
Fármacos Anti-VIH , Infecciones por VIH , Hipertensión , Adulto , Alquinos/efectos adversos , Fármacos Anti-VIH/efectos adversos , Antihipertensivos/uso terapéutico , Benzoxazinas/efectos adversos , Ciclopropanos/efectos adversos , Femenino , Infecciones por VIH/tratamiento farmacológico , Humanos , Hipertensión/epidemiología , Masculino , Persona de Mediana Edad , Factores de Riesgo , Ritonavir/efectos adversos , Estavudina/efectos adversos
8.
Sci Rep ; 12(1): 2893, 2022 02 21.
Artículo en Inglés | MEDLINE | ID: mdl-35190594

RESUMEN

Polarisation-sensitive optical coherence tomography (PS-OCT) offers a novel, non-invasive method of assessing skin fibrosis in the multisystem disease systemic sclerosis (SSc) by measuring collagen retardance. This study aimed to assess retardance as a biomarker in SSc. Thirty-one patients with SSc and 27 healthy controls (HC) underwent PS-OCT imaging. 'Skin score' was assessed by clinical palpation (0-3 scale). A subset of ten patients and ten age/sex-matched HC had a biopsy and longitudinal imaging. Histological assessment included quantification of epidermal thickness, collagen content (to assess fibrosis) and matrix metalloproteinase (MMP) activity (in situ zymography). PS-OCT images were assessed for epidermal thickness (structure) and fibrosis (retardance). Positive correlation was observed between epidermal thickness as measured by histology and structural PS-OCT (r = 0.79; p < 0.001). Retardance was: HC mean 0.21 (SD 0.21) radian/pixel; SSc skin score 0, 0.30 (0.19); skin score 1, 0.11 (0.16); skin score 2, 0.06 (0.12); skin score 3, 0.36 (0.35). Longitudinal retardance decreased at one-week across groups, increasing at one-month for HC/skin score 0-1; HC biopsy site retardance suggests scarring is akin to fibrosis. Relationships identified between retardance with both biopsy and skin score data indicate that retardance warrants further investigation as a suitable biomarker for SSc-related fibrosis.


Asunto(s)
Esclerodermia Sistémica/diagnóstico por imagen , Piel/diagnóstico por imagen , Piel/patología , Tomografía de Coherencia Óptica/métodos , Adulto , Anciano , Biomarcadores , Colágeno/metabolismo , Femenino , Fibrosis , Humanos , Masculino , Persona de Mediana Edad , Esclerodermia Sistémica/patología , Piel/metabolismo , Factores de Tiempo
9.
Clin Immunol Commun ; 2: 130-135, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38013966

RESUMEN

INTRODUCTION: The AbC-19™ lateral flow immunoassay (LFIA) performance was evaluated on plasma samples from a SARS-CoV-2 vaccination cohort, WHO international standards for anti-SARS-CoV-2 IgG (human), individuals ≥2 weeks from infection of RT-PCR confirmed SARS-CoV-2 genetic variants, as well as microorganism serology. METHODS: Pre-vaccination to three weeks post-booster samples were collected from a cohort of 111 patients (including clinically extremely vulnerable patients) from Northern Ireland. All patients received Oxford-AstraZeneca COVID-19 vaccination for the first and second dose, and Pfizer-BioNTech for the third (first booster). WHO international standards, 15 samples from 2 variants of concern (Delta and Omicron) and cross-reactivity with plasma samples from other microorganism infections were also assessed on AbC-19™. RESULTS: All 80 (100%) participants sampled post-booster had high positive IgG responses, compared to 38/95 (40%) participants at 6 months post-first vaccination. WHO standard results correlated with information from corresponding biological data sheets, and antibodies to all genetic variants were detected by LFIA. No cross-reactivity was found with exception of one (of five) Dengue virus samples. CONCLUSION: These findings suggest BNT162b2 booster vaccination enhanced humoral immunity to SARS-CoV-2 from pre-booster levels, and that this antibody response was detectable by the LFIA. In combination with cross-reactivity, standards and genetic variant results would suggest LFIA may be a cost-effective measure to assess SARS-CoV-2 antibody status.

10.
Neurobiol Aging ; 109: 113-124, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34715442

RESUMEN

Layer 3 (L3) pyramidal neurons in aged rhesus monkey lateral prefrontal cortex (LPFC) exhibit significantly elevated excitability in vitro and reduced spine density compared to neurons in young subjects. The time-course of these alterations, and whether they can be ameliorated in middle age by the powerful anti-oxidant curcumin is unknown. We compared the properties of L3 pyramidal neurons from the LPFC of behaviorally characterized rhesus monkeys over the adult lifespan using whole-cell patch clamp recordings and neuronal reconstructions. Working memory (WM) impairment, neuronal hyperexcitability, and spine loss began in middle age. There was no significant relationship between neuronal properties and WM performance. Middle-aged subjects given curcumin exhibited better WM performance and less neuronal excitability compared to control subjects. These findings suggest that the appropriate time frame for intervention for age-related cognitive changes is early middle age, and points to the efficacy of curcumin in delaying WM decline. Because there was no relationship between excitability and behavior, the effects of curcumin on these measures appear to be independent.


Asunto(s)
Envejecimiento/efectos de los fármacos , Envejecimiento/patología , Curcumina/administración & dosificación , Curcumina/farmacología , Suplementos Dietéticos , Memoria a Corto Plazo/efectos de los fármacos , Memoria a Corto Plazo/fisiología , Corteza Prefrontal/efectos de los fármacos , Corteza Prefrontal/patología , Células Piramidales/efectos de los fármacos , Células Piramidales/patología , Factores de Edad , Envejecimiento/psicología , Animales , Femenino , Macaca mulatta , Masculino , Técnicas de Placa-Clamp , Células Piramidales/fisiología , Factores de Tiempo
11.
Gastrointest Endosc ; 94(1): 60-67.e1, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33385462

RESUMEN

BACKGROUND AND AIMS: Portal pressure can be used to identify patients with chronic liver disease who have progressed to cirrhosis. Portal pressure can also provide accurate prognostication for patients with cirrhosis. However, there are no practical means for assessment of portal pressure. Although it is well established that the gastric mucosal blood supply increases in patients with cirrhosis, this has been difficult to quantify reproducibly. Our group has developed a novel spectroscopic technology called spatially resolved subdiffuse reflectance spectroscopy (SRSRS), which enables quantification of mucosal microcirculation. We aim to ascertain if quantification of the gastric mucosal microcirculation with SRSRS correlates with clinical evidence of portal hypertension. METHODS: Patients undergoing EGD for clinical indications had 10 measurements taken in the endoscopically normal gastric fundus via SRSRS probe to assess the microcirculation. Cases were defined as patients with cirrhosis (n = 18), and controls were those without evidence of liver disease (n = 18); this was corroborated with transient elastography. RESULTS: The blood volume fraction (P = .06) and subdiffuse reflectance (P = .02) from a shallow depth in the gastric fundus were higher in patients with cirrhosis than those without. These markers were combined to yield an overall optical marker that can differentiate patients with cirrhosis from controls with a sensitivity of 72% and specificity of 94% (area under receiver operating curve, 0.82). CONCLUSIONS: Spectroscopic quantification of gastric fundal mucosal microcirculation is a promising surrogate of clinical correlates of portal hypertension. This approach may represent a less-intrusive surrogate biomarker for liver disease prognostication and potentially response to therapy.


Asunto(s)
Hipertensión Portal , Biomarcadores , Mucosa Gástrica , Humanos , Hipertensión Portal/diagnóstico por imagen , Cirrosis Hepática/complicaciones , Cirrosis Hepática/diagnóstico por imagen , Microcirculación , Análisis Espectral
12.
Rheumatol Int ; 41(6): 1089-1096, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-32797279

RESUMEN

Objective methods are needed to quantify digital artery disease in systemic sclerosis (SSc) for clinical trials of vascular therapies. Our primary aim was to examine feasibility of a novel tomographic three-dimensional-(3-D) ultrasound (tUS) with high-frequency ultrasound (HFUS) or ultra-high-frequency ultrasound (UHFUS) to assess the digital arteries in patients with SSc compared to healthy controls. A secondary objective was to compare the total wall volume (TWV) as a measure of intimal/medial thickness. Eighteen patients with a confirmed diagnosis of SSc were studied by tUS HFUS (17.5 MHz, n = 10) or tUS UHFUS (48 and 70 MHz, n = 8) with equal numbers of healthy controls of similar age and gender. The majority of patients had limited cutaneous SSc and were representative of a spectrum of digital vasculopathy, with over half (n = 6 HFUS and n = 5 UHFUS) having previous digital ulceration. Over half were receiving oral vasodilatory therapy. TWV was measured in both digital arteries of the middle finger bilaterally. At least, two digital arteries could be identified at 17.5 MHz in all patients and healthy controls. Whereas, at least two digital arteries could be identified in relatively fewer patients compared to healthy controls using 48 MHz (n = 6 and 10) and especially 70 MHz (n = 4 and 10) UHFUS. The median difference in TWV between patients and healthy controls was -6.49 mm3 using 17.5 MHz, 1.9 mm3 at 48 MHz, and -0.4 mm3 at 70 MHz. tUS using UHFUS is a feasible method to measure TWV of digital arteries in SSc. Transducer frequency plays an important factor in successful digital artery measurement, with 48 MHz being the optimal frequency.


Asunto(s)
Arterias/diagnóstico por imagen , Dedos/irrigación sanguínea , Esclerodermia Sistémica/complicaciones , Anciano , Estudios de Casos y Controles , Estudios Transversales , Femenino , Dedos/diagnóstico por imagen , Humanos , Imagenología Tridimensional , Masculino , Persona de Mediana Edad , Esclerodermia Sistémica/fisiopatología , Tomografía Computarizada por Rayos X , Ultrasonografía
13.
medRxiv ; 2020 Sep 18.
Artículo en Inglés | MEDLINE | ID: mdl-32995812

RESUMEN

BACKGROUND: The COVID-19 pandemic has major ramifications for global health and the economy, with growing concerns about economic recession and implications for mental health. Here we investigated the associations between COVID-19 pandemic-related income loss with financial strain and mental health trajectories over a 1-month course. METHODS: Two independent studies were conducted in the U.S and in Israel at the beginning of the outbreak (March-April 2020, T1; N = 4 171) and at a 1-month follow-up (T2; N = 1 559). Mixed-effects models were applied to assess associations among COVID-19-related income loss, financial strain, and pandemic-related worries about health, with anxiety and depression, controlling for multiple covariates including pre-COVID-19 income. FINDINGS: In both studies, income loss and financial strain were associated with greater depressive symptoms at T1, above and beyond T1 anxiety, worries about health, and pre-COVID-19 income. Worsening of income loss was associated with exacerbation of depression at T2 in both studies. Worsening of subjective financial strain was associated with exacerbation of depression at T2 in one study (US). INTERPRETATION: Income loss and financial strain were uniquely associated with depressive symptoms and the exacerbation of symptoms over time, above and beyond pandemic-related anxiety. Considering the painful dilemma of lockdown versus reopening, with the tradeoff between public health and economic wellbeing, our findings provide evidence that the economic impact of COVID-19 has negative implications for mental health. FUNDING: This study was supported by grants from the National Institute of Mental Health, the US-Israel Binational Science Foundation, Foundation Dora and Kirsh Foundation.

14.
Phys Rev Lett ; 125(2): 025103, 2020 Jul 10.
Artículo en Inglés | MEDLINE | ID: mdl-32701350

RESUMEN

We report measurements of lower-hybrid drift waves driving electron heating and vortical flows in an electron-scale reconnection layer under a guide field. Electrons accelerated by the electrostatic potential of the waves exhibit perpendicular and nongyrotropic heating. The vortical flows generate magnetic field perturbations comparable to the guide field magnitude. The measurements reveal a new regime of electron-wave interaction and how this interaction modifies the electron dynamics in the reconnection layer.

15.
Scand J Rheumatol ; 49(3): 239-243, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31928291

RESUMEN

Objective: Despite being a cardinal clinical sign of systemic sclerosis (SSc), digital pitting has been little studied. Our objective was to test, in a pilot study, the hypothesis that pitting is painful and associated with digital vascular disease severity.Method: Fifty patients with SSc were recruited: 25 with and 25 without digital pitting. Fingertip pain was assessed on a 0-10 scale. Thermography of both hands assessed surface temperature, allowing calculation of the distal-dorsal difference (temperature gradient) for each finger. Nailfold capillaroscopy was performed in each finger using a dermatoscope, and graded on a 0-3 scale (0 = normal; 3 = grossly abnormal).Results: In the 25 patients with digital pitting, 65 fingers in total were affected (mainly the index and middle fingers). Pain scores were higher in 'pitting' patients [median 4 (interquartile range 3-8) vs 0 (0-2), p < 0.001], and pitting patients reported that pitting impacted on activities of everyday living. Temperature gradients along the fingers did not differ significantly between patients with and without pitting (p = 0.248). Pitting patients were more likely to have 'grossly abnormal' capillaries than those without pitting, and less likely to have 'no/mild' nailfold capillary changes.Conclusions: Digital pitting is painful and impacts on hand function. Capillaroscopy findings provide further support for an association between pitting and severity of digital vascular change. Larger, more comprehensive studies are required to examine the pathophysiology of pitting and to pave the way to therapeutic intervention, ideally including preventive strategies.


Asunto(s)
Dedos/fisiopatología , Dolor/fisiopatología , Esclerodermia Difusa/fisiopatología , Esclerodermia Limitada/fisiopatología , Anciano , Estudios de Casos y Controles , Femenino , Dedos/irrigación sanguínea , Dedos/patología , Humanos , Masculino , Angioscopía Microscópica , Persona de Mediana Edad , Dolor/etiología , Proyectos Piloto , Esclerodermia Difusa/complicaciones , Esclerodermia Difusa/patología , Esclerodermia Limitada/complicaciones , Esclerodermia Limitada/patología , Esclerodermia Sistémica/fisiopatología , Venenos de Escorpión , Índice de Severidad de la Enfermedad , Úlcera Cutánea/etiología , Termografía
16.
Integr Org Biol ; 2(1): obaa006, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33791550

RESUMEN

Warning signals in chemically defended organisms are critical components of predator-prey interactions, often requiring multiple coordinated display components for effective communication. When threatened by a predator, venomous coral snakes (genus Micrurus) display a vigorous, non-locomotory thrashing behavior that has previously been qualitatively described. Given the high contrast and colorful banding patterns of these snakes, this thrashing display is hypothesized to be a key component of a complex aposematic signal under strong stabilizing selection across species in a mimicry system. By experimentally testing snake response across simulated predator cues, we analyzed variation in the presence and expression of a thrashing display across five species of South American coral snakes. Although the major features of the thrash display were conserved across species, we found that predator cue type, snake body size, and species identity predict significant inter- and intraspecific variation in the propensity to perform a display, the duration of thrashing, and the curvature of snake bodies. We also found an interaction between curve magnitude and body location that clearly shows which parts of the display vary most across individuals and species. Our results suggest that contrary to the assumption that all Micrurus species and individuals perform the same display, a high degree of variation exists despite presumably strong selection to conserve a common signal. This quantitative behavioral characterization presents a new framework for analyzing the non-locomotory motions displayed by snakes in a broader ecological context, especially for signaling systems with complex interaction across multiple modalities.


Un análisis cuantitativo de las serpientes coral (Genero: Micrurus) revela una variación inesperada de los comportamientos anti-depredadores estereotipados dentro de un sistema de mímicoLas señales de advertencia en organismos con defensas químicas son componentes críticos de las interacciones depredador-presa, que a menudo requieren múltiples componentes de visualización coordinados para una comunicación efectiva. Cuando son amenazadas por un depredador, las serpientes de coral venenosas (género Micrurus) muestran un comportamiento vigoroso de coletazos, no locomotor, que solo se ha descrito cualitativamente. Dado el alto contraste y los patrones de bandas coloridas de estas serpientes, se supone que este comportamiento de coletazos es un componente clave de una señal aposemática compleja bajo una fuerte selección estabilizadora entre especies en un sistema de mímica. Al probar experimentalmente la respuesta de las serpientes a través de señales simuladas de depredadores, analizamos la variación en la presencia y la expresión de coletazos en cinco especies de serpientes de coral de América del Sur. Aunque las principales características de la muestra se conservaron en todas las especies, encontramos que el tipo de señal de depredación, el tamaño del cuerpo de la serpiente y la especie en si predicen una variación significativa inter e intraespecífica en la probabilidad a realizar la conducta, la duración del coletazo y la curvatura del cuerpo de las serpientes. También encontramos una interacción entre la magnitud de la curva y la ubicación del cuerpo que muestra claramente qué partes del cuerpo varían más entre individuos y especies. Nuestros resultados sugieren que, contrariamente a la suposición de que todas las especies e individuos realizan el mismo comportamiento, persiste un alto grado de variación en el comportamiento de coletazos exhibido por las serpientes de coral Micrurus a pesar de una selección presumiblemente fuerte para converger en una señal común. Esta caracterización cuantitativa del comportamiento presenta un nuevo marco para analizar los movimientos no locomotores mostrados por las serpientes en un contexto ecológico más amplio, especialmente para los sistemas de señalización con interacción compleja a través de múltiples modalidades. Translated to Spanish by YE Jimenez (yordano_jimenez@brown.edu).

17.
Anal Chem ; 92(2): 2052-2057, 2020 01 21.
Artículo en Inglés | MEDLINE | ID: mdl-31874025

RESUMEN

Cortisol is an important steroid hormone in human physiology. Variations or abnormalities in the physiological cortisol levels control acute and chronic stress response, as well as contribute to diseases and syndromes including Addison's disease and Cushing syndrome. The ability to monitor cortisol levels in the physiological range is key in diagnosis and monitoring of these conditions, where current methodology for determination of cortisol levels relies on instrumentation that requires extensive sample preparation, long run times, and is destructive to the sample. Raman spectroscopy provides rapid sample analysis with relatively simple instrumentation; however, Raman spectroscopy is an inherently weak technique. To provide an enhanced Raman signal, we use surface enhanced Raman spectroscopy (SERS) which utilizes oscillating electric fields of metal nanoparticles, enhancing the overall electric field and therefore resulting in an enhanced signal. We demonstrate SERS-based detection of cortisol in the physiologically relevant range using colloidal silver nanoparticles in ethanolic solutions and bovine serum albumin. The SERS spectra obtained in an ethanol matrix demonstrate a sigmoidal concentration response over the physiologically relevant concentration range, with a limit of detection established at 177 nM. Analysis of cortisol solutions in a complex matrix (bovine serum albumin in phosphate buffered saline) is also demonstrated through the use of principal components analysis, a multivariate technique, which shows the separation of cortisol in a linear fashion with respect to cortisol concentration.


Asunto(s)
Hidrocortisona/análisis , Animales , Bovinos , Teoría Funcional de la Densidad , Hidroxilamina/química , Nanopartículas del Metal/química , Conformación Molecular , Albúmina Sérica Bovina/química , Plata/química , Espectrometría Raman , Propiedades de Superficie
18.
Restor Neurol Neurosci ; 37(4): 347-362, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-31282441

RESUMEN

BACKGROUND: Exosomes from mesenchymal stromal cells (MSCs) are endosome-derived vesicles that have been shown to enhance functional recovery in rodent models of stroke. OBJECTIVE: Building on these findings, we tested exosomes as a treatment in monkeys with cortical injury. METHODS: After being trained on a task of fine motor function of the hand, monkeys received a cortical injury to the hand representation in primary motor cortex. Twenty-four hours later and again 14 days after injury, monkeys received exosomes or vehicle control. Recovery of motor function was followed for 12 weeks. RESULTS: Compared to monkeys that received vehicle, exosome treated monkeys returned to pre-operative grasp patterns and latency to retrieve a food reward in the first three-five weeks of recovery. CONCLUSIONS: These results provide evidence that in monkeys exosomes delivered after cortical injury enhance recovery of motor function.


Asunto(s)
Exosomas , Corteza Motora/efectos de los fármacos , Corteza Motora/lesiones , Destreza Motora/efectos de los fármacos , Recuperación de la Función/efectos de los fármacos , Animales , Conducta Animal/efectos de los fármacos , Modelos Animales de Enfermedad , Macaca mulatta
19.
Phys Rev E ; 99(4-1): 043204, 2019 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-31108651

RESUMEN

The electron diffusion region (EDR) is the region where magnetic reconnection is initiated and electrons are energized. Because of experimental difficulties, the structure of the EDR is still poorly understood. A key question is whether the EDR has a homogeneous or patchy structure. Here we report Magnetospheric Multiscale (MMS) spacecraft observations providing evidence of inhomogeneous current densities and energy conversion over a few electron inertial lengths within an EDR at the terrestrial magnetopause, suggesting that the EDR can be rather structured. These inhomogenenities are revealed through multipoint measurements because the spacecraft separation is comparable to a few electron inertial lengths, allowing the entire MMS tetrahedron to be within the EDR most of the time. These observations are consistent with recent high-resolution and low-noise kinetic simulations.

20.
Nature ; 569(7757): E9, 2019 May.
Artículo en Inglés | MEDLINE | ID: mdl-31073227

RESUMEN

Change history: In this Letter, the y-axis values in Fig. 3f should go from 4 to -8 (rather than from 4 to -4), the y-axis values in Fig. 3h should appear next to the major tick marks (rather than the minor ticks), and in Fig. 1b, the arrows at the top and bottom of the electron-scale current sheet were going in the wrong direction; these errors have been corrected online.

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