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1.
Proc Natl Acad Sci U S A ; 120(11): e2216286120, 2023 03 14.
Artículo en Inglés | MEDLINE | ID: mdl-36897974

RESUMEN

Unlike most higher plants, unicellular algae can acclimate to changes in irradiance on time scales of hours to a few days. The process involves an enigmatic signaling pathway originating in the plastid that leads to coordinated changes in plastid and nuclear gene expression. To deepen our understanding of this process, we conducted functional studies to examine how the model diatom, Phaeodactylum tricornutum, acclimates to low light and sought to identify the molecules responsible for the phenomenon. We show that two transformants with altered expression of two putative signal transduction molecules, a light-specific soluble kinase and a plastid transmembrane protein, that appears to be regulated by a long noncoding natural antisense transcript, arising from the opposite strand, are physiologically incapable of photoacclimation. Based on these results, we propose a working model of the retrograde feedback in the signaling and regulation of photoacclimation in a marine diatom.


Asunto(s)
Diatomeas , Diatomeas/metabolismo , Fototransducción , Transducción de Señal
2.
J Aging Soc Policy ; : 1-14, 2024 Aug 27.
Artículo en Inglés | MEDLINE | ID: mdl-39190824

RESUMEN

The Human Development Index (HDI) is a proxy for the social and economic level of countries, which is related to the health and well-being of older adults. This study aimed to examine the moderating effect of the HDI on the relationship between frailty and health-related quality of life among European older adults. Participants were 23,972 older adults (53.2% female, M = 74.2 years old, SD = 6.75 years old) from 24 European countries, joining wave 8 (2020) of the Survey of Health, Aging, and Retirement in Europe (SHARE). Multilevel modeling was used to analyze nested data. Significant differences in health-related quality of life among the several European Union countries were observed (intraclass correlation coefficient [ICC] = 0.18, LRT (1) = 5568.07, p < .001). The HDI has been shown to moderate the relationship between frailty and health-related quality of life among older adults, buffering the impact of frailty on the health-related quality of life. Since healthy aging is a priority for the European Union, policies mitigating the impact of HDI on the relationship between frailty and health-related quality of life should be implemented.

3.
Curr Psychol ; : 1-19, 2023 Jan 13.
Artículo en Inglés | MEDLINE | ID: mdl-36684465

RESUMEN

Based on social cognitive, reasoned action, and basic needs theories, this study examines whether co-rumination with others about the job search mediates the positive relation between state negative affect and job search intentions. In addition, we looked at how this positive indirect effect interacts with the social support received from different sources (such as friends, family, and significant others) at the beginning and six months after the initial job search process. Using a sample of 87 graduates (job seekers) from a Portuguese masters program, we used multilevel modeling to test this moderated mediation. Ages ranged from 22 to 53 years old (M = 29.45; SD = 7.60). Data were collected using measures to assess negative affect, co-rumination, perceived social support, and job search intentions. We found an indirect effect of state negative affect on job search intentions; when job seekers perceive higher levels of social support from significant others at the beginning of the job search, the positive, mediating role of co-rumination in this relationship is increased. Further, for a sub-sample of six-month job seekers, this positive indirect effect increased when there was also an increased perception of social support from family. Discussion focuses on implications for theory and practice and the role of co-rumination for unemployed people during job search.

4.
BMC Nephrol ; 23(1): 218, 2022 06 21.
Artículo en Inglés | MEDLINE | ID: mdl-35729492

RESUMEN

BACKGROUND: The vascular access preservation and the maintenance of a complication-free fistula remains an Achilles' heel of hemodialysis in chronic kidney patients due to its substantial contribution to the morbidity and mortality. Systematic studies in the area of examining cannulation practices, achieving complication-free cannulation, and strategies to improve fistula survival are needed. For this reason, we consider it essential to create and investigate new methodologies for approaching fistula in patients on regular HD. The Multiple Single Cannulation Technique (MuST) is based on the association between the rope-ladder (RL) using the arteriovenous vessel through progressive rotation, and the buttonhole (BH) since there are three specific cannulation sites for each cannulation day during the week. The MuST is simple to implement and seems to be a very promising technique in terms of patient safety. Previous studies already showed an arteriovenous fistula survival similar to RL but significantly higher than BH. METHODS: This MuST study is a multicenter, prospective, non-blind, parallel-group, randomized controlled trial with the intervention group submitted to MuST and a control group undergoing the rope-ladder, up to 100 subjects for each group. Patients will be randomized 1:1 to one of two cannulation technique (CT), and the follow-up period of this study will be 12 months. Primary outcome is to evaluate the arteriovenous fistula survival rate at 12 months determined by the percentage of fistulas in use from the beginning of the study to the date of the first clinical intervention by angioplasty or vascular surgery, to maintain or restore patency (unassisted patency). Secondary outcome is to evaluate arteriovenous fistula survival rate at 12 month determined by the percentage of fistulas in use from the study start to the date of access abandonment due to dysfunction, patient abandonment, or death, treatment change modality or study end. We will also evaluate the assisted primary patency and include the following secondary outcomes associated with the cannulation technique: Infection, Hematoma, Aneurysm development, and pain. DISCUSSION: The study will investigate whether fistula survival can be improved when using cannulation by MuST compared to the RL. MuST study will provide important information on fistula survival when cannulated by MuST but also information related to its use in fistulas previously cannulated by other CTs. TRIAL REGISTRATION: ClinicalTrials.gov identifier NCT05081648 registered on 18 October 2021.


Asunto(s)
Fístula Arteriovenosa , Derivación Arteriovenosa Quirúrgica , Derivación Arteriovenosa Quirúrgica/métodos , Cateterismo/métodos , Humanos , Estudios Multicéntricos como Asunto , Estudios Prospectivos , Ensayos Clínicos Controlados Aleatorios como Asunto , Diálisis Renal/métodos , Resultado del Tratamiento , Grado de Desobstrucción Vascular
5.
Molecules ; 27(15)2022 Aug 05.
Artículo en Inglés | MEDLINE | ID: mdl-35956930

RESUMEN

A sequential design strategy was applied to optimize the secretion of pectinases by a Saccharomyces cerevisiae strain, from Brazilian sugarcane liquor vat, on passion fruit residue flour (PFRF), through solid-state fermentation (SSF). A factorial design was performed to determine the influence variables and two rotational central composite designs were executed. The validated experimental result was of 7.1 U mL-1 using 50% PFRF (w/w), pH 5, 30 °C for 24 h, under static SSF. Polygalacturonase, pectin methyl esterase, pectin-lyase and pectate-lyase activities were 3.5; 0.08; 3.1 and 0.8 U mL-1, respectively. Shotgun proteomics analysis of the crude extract enabled the identification of two pectin-lyases, one pectate-lyase and a glucosidase. The crude enzymatic extract maintained at least 80% of its original activity at pH values and temperatures ranging from 2 to 8 and 30 to 80 °C, respectively, over 60 min incubation. Results revealed that PFRF might be a cost-effective and eco-friendly substrate to produce pectinases. Statistical optimization led to fermentation conditions wherein pectin active proteins predominated. To the extent of our knowledge, this is the first study reporting the synthesis of pectate lyase by S. cerevisiae.


Asunto(s)
Poligalacturonasa , Saccharomyces cerevisiae , Fermentación , Concentración de Iones de Hidrógeno , Pectinas/metabolismo , Poligalacturonasa/metabolismo , Proteómica , Saccharomyces cerevisiae/metabolismo
6.
Nephrol Nurs J ; 48(2): 169-176, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-33886247

RESUMEN

Although buttonhole cannulation has some benefits compared to rope-ladder cannulation, the increase of infection rates represents a major obstacle to patient safety, and its use is questionable in routine clinic practice. On the other hand, rope-ladder cannulation is difficult to implement even with a prescribed protocol, leading the cannulator in daily practice to a possible use of the area technique. This article provides a reflection on the impact of cannulation technique on the safety of patients on regular hemodialysis treatment and describes a new approach for arteriovenous fistula cannulation, the Multiple Single Cannulation Technique (MuST). The MuST has not been described before, but it has been used with promising results. Further studies are needed to confirm the benefits of this cannulation technique.


Asunto(s)
Fístula Arteriovenosa , Derivación Arteriovenosa Quirúrgica , Instituciones de Atención Ambulatoria , Derivación Arteriovenosa Quirúrgica/efectos adversos , Cateterismo/efectos adversos , Humanos , Diálisis Renal/efectos adversos
7.
Ann Sci ; 77(1): 10-25, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-32250204

RESUMEN

Astrologers have exercised self-censorship throughout the centuries in order to fend off criticism. This was largely for religious reasons, but social, political, and ethical motivations also have to be taken into account. This paper explores the main reasons that led astrologers to increase censorship in their writings in the decades that preceded the Church's regulations and offers some examples of this self-imposed restraint in astrological judgements.


Asunto(s)
Astrología/historia , Censura de la Investigación , Cristianismo/historia , Religión y Ciencia , Europa (Continente) , Historia del Siglo XV , Historia Medieval
8.
Nitric Oxide ; 88: 73-86, 2019 07 01.
Artículo en Inglés | MEDLINE | ID: mdl-31026500

RESUMEN

The identification of S-nitrosated substrates and their target cysteine residues is a crucial step to understand the signaling functions of nitric oxide (NO) inside the cells. Here, we show that the key nitrogen metabolic enzyme glutamine synthetase (GS) is a S-nitrosation target in Medicago truncatula and characterize the molecular determinants and the effects of this NO-induced modification on different GS isoenzymes. We found that all the four M. truncatula GS isoforms are S-nitrosated, but despite the high percentage of amino acid identity between the four proteins, S-nitrosation only affects the activity of the plastid-located enzymes, leading to inactivation. A biotin-switch/mass spectrometry approach revealed that cytosolic and plastid-located GSs share an S-nitrosation site at a conserved cysteine residue, but the plastidic enzymes contain additional S-nitrosation sites at non-conserved cysteines, which are accountable for enzyme inactivation. By site-directed mutagenesis, we identified Cys369 as the regulatory S-nitrosation site relevant for the catalytic function of the plastid-located GS and an analysis of the structural environment of the SNO-targeted cysteines in cytosolic and plastid-located isoenzymes explains their differential regulation by S-nitrosation and elucidates the mechanistic by which S-nitrosation of Cys369 leads to enzyme inactivation. We also provide evidence that both the cytosolic and plastid-located GSs are endogenously S-nitrosated in leaves and root nodules of M. truncatula, supporting a physiological meaning for S-nitrosation. Taken together, these results provide new insights into the molecular details of the differential regulation of individual GS isoenzymes by NO-derived molecules and open new paths to explore the biological significance of the NO-mediated regulation of this essential metabolic enzyme.


Asunto(s)
Glutamato-Amoníaco Ligasa/metabolismo , Proteínas de Plantas/metabolismo , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Cisteína/química , Glutamato-Amoníaco Ligasa/química , Glutamato-Amoníaco Ligasa/genética , Glutamato-Amoníaco Ligasa/aislamiento & purificación , Isoenzimas/química , Isoenzimas/genética , Isoenzimas/aislamiento & purificación , Isoenzimas/metabolismo , Medicago truncatula/enzimología , Medicago truncatula/metabolismo , Mutagénesis Sitio-Dirigida , Nitrosación , Hojas de la Planta/enzimología , Hojas de la Planta/metabolismo , Proteínas de Plantas/química , Proteínas de Plantas/genética , Proteínas de Plantas/aislamiento & purificación , Procesamiento Proteico-Postraduccional , Nódulos de las Raíces de las Plantas/enzimología , Nódulos de las Raíces de las Plantas/metabolismo , Alineación de Secuencia
9.
J Sports Sci ; 37(6): 692-700, 2019 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-30326773

RESUMEN

Football is central to the lives of countless individuals around the globe. While most of the attention of those passionate about the sport is focused on the players, football referees are often just as important in shaping the outcome of the games. Therefore, research is increasingly examining the role of referees. Even so, our understanding of the factors that create an excellent football referee is still scarce. Based on our analysis of the opinions of 24 football experts, we demonstrate the multidimensionality of excellence in the performance of football referees. From a Categorical Principal Components Analysis (CatPCA), we were able to pinpoint that football referee excellence is shaped by three distinct dimensions: individual preparation, game preparation and game management. Additionally, we were able to see if these perceptions were different from individuals "within" the game versus those "outside" the game. Namely, we used CatPCA to graphically display the main correlations between the latent dimensions of football refereeing performance and the "inside" and "outside" perspective of the game. The findings of our work contribute towards the knowledge of the factors that shape football referee excellence, while also highlighting areas in need of additional research attention.


Asunto(s)
Conocimiento , Competencia Profesional , Fútbol , Humanos
10.
Hum Psychopharmacol ; 32(3)2017 05.
Artículo en Inglés | MEDLINE | ID: mdl-28635119

RESUMEN

OBJECTIVE: This paper describes the misrepresentation of LSD at Portugal's Boom Festival 2014 and the prevention of unintentional consumption of DOx and 25x-NBOMe among LSD consumers attending a drug-checking service. METHODS: Two hundred forty-five drug samples expected to contain LSD were submitted to the drug-checking service for chemical analysis. One hundred ten post-test questionnaires were successfully matched with test results. RESULTS: About 67.3% of the alleged LSD samples tested contained only LSD; 0.8% contained LSD combined with adulterants; 24.1% did not contain LSD but did contain another psychoactive substance, including 11.4% that were 2,5-dimethoxyamphetamine derivatives and 9.8% that were N-benzyl-2,5-dimethoxyphenethylamine derivatives; and no psychoactive substance was detected in 7.8%. The majority of service users who received unexpected test results regarding their alleged LSD (74.2%) reported that they did not intend to consume the drug. Following dissemination of alerts on day 2, a larger than expected proportion of all tests conducted were for LSD, when comparing the 2014 festival to 2012, where no such alert was disseminated. CONCLUSIONS: Although these results support the provision of integrated drug-checking services in party settings, evidence of their utility and effectiveness would be improved through future research incorporating more robust measures of outcomes following provision of drug-checking results.


Asunto(s)
Anfetaminas/análisis , Alucinógenos/análisis , Vacaciones y Feriados , Drogas Ilícitas/análisis , Dietilamida del Ácido Lisérgico/análisis , Detección de Abuso de Sustancias/métodos , Anfetaminas/efectos adversos , Contaminación de Medicamentos/prevención & control , Alucinógenos/efectos adversos , Humanos , Drogas Ilícitas/efectos adversos , Dietilamida del Ácido Lisérgico/efectos adversos , Portugal/epidemiología , Detección de Abuso de Sustancias/normas
11.
Hum Resour Health ; 15(1): 82, 2017 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-29233172

RESUMEN

BACKGROUND: The European Union member countries reacted differently to the 2008 economic and financial crisis. However, few countries have monitored the outcomes of their policy responses, and there is therefore little evidence as to whether or not savings undermined the performance of health systems. We discuss the situation in Portugal, where a financial adjustment program was implemented between 2011 and 2014, and explore the views of health workers on the effects of austerity measures on quality of care delivery. METHODS: A nationwide survey of physicians' experiences was conducted in 2013-2014 (n = 3442). We used a two-step model to compare public and private services and look at the possible moderating effects of the physicians' specialty and years of practice. Our data analysis included descriptive statistics, the independent t test, analysis of variance (ANOVA), multivariate logistic regression, General Linear Model Univariate Analysis, non-parametric methods (bootstrap), and post hoc probing. RESULTS: Mainly in the public sector, the policy goal of maintaining quality of care was undermined by a lack of resources, the deterioration in medical residency conditions, and to a lesser extent, greater administrative interference in clinical decision-making. Differences in public and private services showed that the effects of the austerity measures were not the same throughout the health system. Our results also showed that physicians with similar years of practice and in the same medical specialty did not necessarily experience the same pressures. CONCLUSIONS: The debate on the effects of austerity measures should focus more closely on health workers' concrete experiences, as they demonstrate the non-linearity between policy setting and expected outcomes. We also suggest that it is necessary to explore the interplay between lower quality and the undermining of trust relationships in health.


Asunto(s)
Actitud del Personal de Salud , Recesión Económica , Servicios de Salud/normas , Médicos , Sector Privado , Sector Público , Calidad de la Atención de Salud , Atención a la Salud , Política de Salud , Recursos en Salud , Humanos , Satisfacción en el Trabajo , Portugal , Encuestas y Cuestionarios
12.
J Clin Psychol Med Settings ; 24(3-4): 289-301, 2017 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-28752271

RESUMEN

Worries are common in surgical patients, especially in children. The present study analyzed the factor structure and the psychometric properties of a Portuguese version of the Child Surgery Worries Questionnaire (CSWQ-P) in a Portuguese sample of 490 children. Exploratory factor analysis, conducted via principal axis factoring with oblimin rotation, provided evidence for a four-factor structure of the 21 item questionnaire. A confirmatory factor analysis was also conducted, showing the good fit of this solution. The CSWQ-P proved to have one more subscale than the original Spanish version CSWQ. Correlations with the children's trait anxiety provided evidence of convergent validity for the CSWQ-P. Females also scored higher on worries than males on all subscales. Psychometric properties of this revised version of the CSWQ provided support for use with young children, and indicate the CSWQ-P has value for use in healthcare practice and in clinical research.


Asunto(s)
Ansiedad/psicología , Comparación Transcultural , Psicometría/estadística & datos numéricos , Procedimientos Quirúrgicos Operativos/psicología , Encuestas y Cuestionarios , Adolescente , Ansiedad/diagnóstico , Actitud Frente a la Muerte , Carácter , Niño , Preescolar , Femenino , Humanos , Masculino , Reproducibilidad de los Resultados , Factores Sexuales , Estadística como Asunto
13.
Trop Anim Health Prod ; 49(2): 273-279, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-27957652

RESUMEN

This study was conducted on 78 13-month-old crossbred beef heifers that weighed 215 kg in Southern Rio Grande do Sul (RS) State, Brazil. We evaluated the performance of beef heifers that were reared in a pasture system that received a mineral supplement energy-type protein with added sodium lasalocid (LAS). The heifers were randomly and uniformly divided into 2 groups, with 39 animals in each group. One group of animals received a mineral supplement energy-type protein without sodium lasalocid (CON), and the other group received a mineral supplement energy-type protein with added LAS. The mean feed intake, the body weight (BW), the average daily gain (ADG), the body condition score (BCS), and ovarian cyclicity were recorded, and economic parameters were calculated. No differences in supplement intake were observed between the groups, which ensures adequate intake of the other components of the mineral mixture, which are part of the nutritional requirements for the production process. Similarly, no difference in the ADG was observed between treatments. We observed that the heifers in the LAS group had a higher BW gain (51 kg) that the CON heifers (40 kg; P < 0.05). In addition, LAS-supplemented heifers had a higher BCS (3.53) than CON heifers (3.38) at the end of the experiment (P < 0.05). The heifers supplemented with LAS had a higher profitability than the CON heifers, even with the higher cost of the supplement containing LAS; this effect was due to the higher live BW at the end of the study. We concluded that the administration of a mineral supplement energy-type protein with added LAS has beneficial effects on beef heifers in terms of production and economic feasibility.


Asunto(s)
Bovinos/crecimiento & desarrollo , Ionóforos/administración & dosificación , Lasalocido/administración & dosificación , Aumento de Peso/efectos de los fármacos , Alimentación Animal/análisis , Crianza de Animales Domésticos , Animales , Brasil , Dieta/veterinaria , Suplementos Dietéticos/análisis , Femenino , Distribución Aleatoria
14.
Int J Biometeorol ; 60(1): 151-7, 2016 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-26049285

RESUMEN

The objective of this study was to evaluate the seasonal effects of the environment on sperm quality in subtropical region determined by temperature and humidity index (THI). We used 20 Brangus bulls (5/8 Angus × 3/8 Nellore) aged approximately 24 months at the beginning of the study. Semen evaluations were performed twice per season during 1 year. Climate THI data were collected from an automatic weather station from the National Institute of Meteorology. Infrared thermography images were used to determine the temperature of the proximal and distal poles of the testis to assess the testicular temperature gradient (TG). The seasonal effects on seminal and climatic variables were analyzed with ANOVA using MIXED procedure of SAS. Sperm motility in spring (60.1%), summer (57.6%), and autumn (64.5%) showed difference compared to winter (73.0%; P < 0.01). TG was negatively correlated with THI at 18 days (spermiogenesis) (-0.76; P < 0.05) and at 12 days (epididymal transit) (-0.85; P < 0.01). Ocular temperature (OcT) had a positive correlation with THI at 18 days (0.78; P < 0.05) and at 12 days (0.84; P < 0.01). Motility showed a negative correlation with THI only at 18 days (-0.79; P < 0.05). During spermiogenesis, the TG had higher negative correlation compared to OcT (-0.97; P < 0.01) and rectal temperature (-0.72; P < 0.05). Spermatozoa with distal midpiece reflex were correlated with THI during transit epididymis (0.72; P < 0.05). Seminal parameters are not affected when THI reaches 93.0 (spermiogenesis) and 88.0 (epididymal transit). We concluded that infrared thermography can be adopted as an indirect method in order to assess the effect of environmental changes in TG and OcT of Brangus bulls.


Asunto(s)
Bovinos/fisiología , Reproducción , Termografía , Animales , Temperatura Corporal , Humedad , Rayos Infrarrojos , Masculino , Estaciones del Año , Motilidad Espermática , Espermatogénesis , Temperatura , Testículo/fisiología
15.
J Adolesc ; 52: 76-88, 2016 10.
Artículo en Inglés | MEDLINE | ID: mdl-27498001

RESUMEN

Adolescents' signs of emotional insecurity in the context of interparental conflict (IC) - emotional reactivity, internal representations (i.e., constructive/destructive; spillover) and behavioral responses (i.e., withdrawal; inhibition; involvement) - were examined as mediators in the relation between IC and adolescents' self-representations. Self-reported measures were filled out by 221 Portuguese adolescents (59.3% girls; Mage = 12.91), attending public elementary and secondary schools. IC predicted less favorable self-representations. Adolescents' emotional reactivity and withdrawal mediated the relation between IC and emotional and physical appearance self-representations, while conflict spillover representations and constructive family representations mediated associations between IC and instrumental self-representations. This study emphasizes the importance of interparental conflict and adolescent emotional insecurity in the construction of their self-representations, having important theoretical and practical implications. It highlights the value of analyzing the specific role of several emotional insecurity dimensions, and informs practitioners' work aimed at promoting constructive conflict and adaptive emotional regulation skills.


Asunto(s)
Conducta del Adolescente/psicología , Emociones , Conflicto Familiar/psicología , Autoimagen , Adolescente , Niño , Femenino , Humanos , Masculino , Portugal
16.
J Ment Health ; 25(1): 55-61, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-26828897

RESUMEN

BACKGROUND: People with mental illness who internalize stigma often experience reduced self-esteem and impaired quality of life (QOL). AIMS: To propose a theoretical model in which self-esteem mediates the effects of internalized stigma on the multidimensional domains comprising QOL. METHOD: In 403 inpatients and outpatients (DSM-IV, American Psychiatric Association, 1994), from hospital-based and community mental health facilities, self-report measures of internalized stigma (ISMI), self-esteem (RSES) and QOL (WHOQOL-Bref) were administrated. RESULTS: Structural equation modeling results supported the proposed model. Self-esteem fully mediated the relation between internalized stigma and the physical and the social relationships domains, and partially mediated the relationship between internalized stigma and psychological, environment and level of independence QOL domains. Such results provided empirical support and shed light upon previous research. Specifically the results emphasize the mediating role that self-esteem plays in the degree to which internalized stigma exerts a negative effect on specific QOL domains. CONCLUSIONS: Self-esteem appears to be a core element in reducing the negative effects of internalized stigma on aspects of QOL among people with mental illness. These findings suggest there is a crucial impact regarding clinical mental health interventions along with important theoretical implications.


Asunto(s)
Trastornos Mentales/psicología , Calidad de Vida/psicología , Autoimagen , Estereotipo , Adulto , Anciano , Femenino , Humanos , Masculino , Persona de Mediana Edad , Pruebas Psicológicas , Adulto Joven
17.
Mol Plant Microbe Interact ; 28(12): 1353-63, 2015 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-26422404

RESUMEN

Nitric oxide (NO) is involved in various plant-microbe interactions. In the symbiosis between soil bacterium Sinorhizobium meliloti and model legume Medicago truncatula, NO is required for an optimal establishment of the interaction but is also a signal for nodule senescence. Little is known about the molecular mechanisms responsible for NO effects in the legume-rhizobium interaction. Here, we investigate the contribution of the bacterial NO response to the modulation of a plant protein post-translational modification in nitrogen-fixing nodules. We made use of different bacterial mutants to finely modulate NO levels inside M. truncatula root nodules and to examine the consequence on tyrosine nitration of the plant glutamine synthetase, a protein responsible for assimilation of the ammonia released by nitrogen fixation. Our results reveal that S. meliloti possesses several proteins that limit inactivation of plant enzyme activity via NO-mediated post-translational modifications. This is the first demonstration that rhizobia can impact the course of nitrogen fixation by modulating the activity of a plant protein.


Asunto(s)
Óxido Nítrico/fisiología , Proteínas de Plantas/metabolismo , Procesamiento Proteico-Postraduccional/fisiología , Sinorhizobium meliloti/fisiología , Medicago truncatula , Mutación , Sinorhizobium meliloti/genética , Tirosina/metabolismo
18.
Acta Crystallogr D Biol Crystallogr ; 70(Pt 4): 981-93, 2014 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-24699643

RESUMEN

The first step of nitrogen assimilation in higher plants, the energy-driven incorporation of ammonia into glutamate, is catalyzed by glutamine synthetase. This central process yields the readily metabolizable glutamine, which in turn is at the basis of all subsequent biosynthesis of nitrogenous compounds. The essential role performed by glutamine synthetase makes it a prime target for herbicidal compounds, but also a suitable intervention point for the improvement of crop yields. Although the majority of crop plants are dicotyledonous, little is known about the structural organization of glutamine synthetase in these organisms and about the functional differences between the different isoforms. Here, the structural characterization of two glutamine synthetase isoforms from the model legume Medicago truncatula is reported: the crystallographic structure of cytoplasmic GSII-1a and an electron cryomicroscopy reconstruction of plastid-located GSII-2a. Together, these structural models unveil a decameric organization of dicotyledonous glutamine synthetase, with two pentameric rings weakly connected by inter-ring loops. Moreover, rearrangement of these dynamic loops changes the relative orientation of the rings, suggesting a zipper-like mechanism for their assembly into a decameric enzyme. Finally, the atomic structure of M. truncatula GSII-1a provides important insights into the structural determinants of herbicide resistance in this family of enzymes, opening new avenues for the development of herbicide-resistant plants.


Asunto(s)
Glutamato-Amoníaco Ligasa/química , Medicago truncatula/enzimología , Secuencia de Aminoácidos , Citosol/enzimología , Isoenzimas/química , Modelos Moleculares , Datos de Secuencia Molecular , Plastidios/enzimología , Estructura Cuaternaria de Proteína , Análisis de Secuencia de Proteína
19.
Br J Psychol ; 115(2): 324-344, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38049953

RESUMEN

Although the perception of justice is a core need of all individuals, the adaptive value of belief in a just world (BJW)-in everyday life and when facing severe distress-has been typically investigated in separate studies. In this article, we tested, in only one study, the possibility that BJW can be a personal resource and a coping resource. We analysed data from the European Social Survey comprised of random representative samples of 27 European countries (N = 24,776 participants). We considered distressing circumstances both at an individual level (health impairment and financial difficulty) and at a macroeconomic contextual level. The results showed that for people both facing and not facing financial or health-related distress, BJW was positively associated with well-being, supporting BJW as a personal resource. Furthermore, we found that the decrease of well-being of people facing distress, both at an individual level and at a contextual level, compared to people not facing distress, was lower for individuals with higher BJW than for individuals with lower BJW, supporting BJW as a coping resource.


Asunto(s)
Proyectos de Investigación , Justicia Social , Humanos , Encuestas y Cuestionarios , Adaptación Psicológica
20.
Res Psychother ; 27(1)2024 Apr 22.
Artículo en Inglés | MEDLINE | ID: mdl-38695608

RESUMEN

In 1988, Bowlby posited that the emotional availability of psychotherapists in establishing a secure base environment is influenced by their personal relational history. Despite the acknowledged influence of the therapist's attachment on therapeutic processes and outcomes, the therapist's role as a secure base figure has received insufficient attention. This study delves into the connection between psychotherapists' attachment organization and their self-perceived roles as secure base figures within clinical contexts. Additionally, we explore the mediating role of emotion regulation processes in this context. The dataset comprises self-reports from 384 psychotherapists with diverse theoretical orientations. Our analysis reveals both direct and indirect effects of psychotherapists' attachment on the provision of a secure base. Emotion regulation, specifically through the dimension of clarity, emerges as a significant mediator in this relationship. This study offers a distinctive contribution to deepening our understanding of the relational dynamics inherent to psychotherapeutic practice. It sheds light on the nuanced relation between attachment and emotion regulation, influencing the psychotherapist's role as a secure base figure in psychotherapy. The discussion of the results additionally emphasizes key implications for clinical practice and therapists' training.

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