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1.
Sensors (Basel) ; 23(1)2023 Jan 03.
Artículo en Inglés | MEDLINE | ID: mdl-36617123

RESUMEN

The commonly accepted definition of sustainability considers the availability of relevant resources to make an activity feasible and durable while also recognizing users' support as an essential part of the social side of sustainability. IoT represents a disruption in the general scenario of computing for both users and professionals. The real expansion and integration of applications based on IoT depend on our capacity of exploring the necessary skills and professional profiles that are essential for the implementation of IoT projects, but also on the perception of relevant aspects for users, e.g., privacy, legal, IPR, and security issues. Our participation in several EU-funded projects with a focus on this area has enabled the collection of information on both sides of IoT sustainability through surveys but also by collecting data from a variety of sources. Thanks to these varied and complementary sources of information, this article will explore the user and professional aspects of the sustainability of the Internet of Things in practice.


Asunto(s)
Internet de las Cosas , Humanos , Privacidad , Encuestas y Cuestionarios , Europa (Continente)
2.
Sensors (Basel) ; 22(19)2022 Oct 10.
Artículo en Inglés | MEDLINE | ID: mdl-36236779

RESUMEN

Designing and developing artificial intelligence (AI)-based systems that can be trusted justifiably is one of the main issues aviation must face in the coming years. European Union Aviation Safety Agency (EASA) has developed a user guide that could be potentially transformed as means of compliance for future AI-based regulation. Designers and developers must understand how the learning assurance process of any machine learning (ML) model impacts trust. ML is a narrow branch of AI that uses statistical models to perform predictions. This work deals with the learning assurance process for ML-based systems in the field of air traffic control. A conflict detection tool has been developed to identify separation infringements among aircraft pairs, and the ML algorithm used for classification and regression was extreme gradient boosting. This paper analyses the validity and adaptability of EASA W-shaped methodology for ML-based systems. The results have identified the lack of the EASA W-shaped methodology in time-dependent analysis, by showing how time can impact ML algorithms designed in the case where no time requirements are considered. Another meaningful conclusion is, for systems that depend highly on when the prediction is made, classification and regression metrics cannot be one-size-fits-all because they vary over time.


Asunto(s)
Inteligencia Artificial , Aviación , Algoritmos , Aviación/métodos , Certificación , Aprendizaje Automático
3.
BMC Pregnancy Childbirth ; 21(1): 120, 2021 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-33563237

RESUMEN

BACKGROUND: The interaction of hormonal factors are crucial for good foetal development. During the second trimester of gestation, most of the main physiological processes of foetal development occur. Therefore, the aim of this study was to determine the variations in the physiological levels of cortisol, estriol, estrone sulphate, and progesterone during the second trimester (weeks 12-26) in order to establish normal ranges that can serve as indicators of foetal well-being and good functioning of the foetal-placental unit. METHODS: Saliva samples from 106 pregnant women were collected weekly (from week 12 to week 26 of gestation), and hormonal measurements were assayed by an enzyme immunoassay. The technique used for hormone measurements was highly sensitive and served as a non-invasive method for sample collection. RESULTS: The results revealed a statistically significant (p<0.05) difference between cortisol, progesterone, and oestrogens throughout the second trimester, with a more substantial relationship between oestrogens and progesterone [P4-E3 (r=0.427); P4-E1SO4 (r=0.419)]. By analysing these hormone concentrations, statistically significant (p<0.05) elevations in progesterone, cortisol, and estriol levels were found at the 16th [(P4 (0.78±0.088), C(1.99±0.116), E3(2.513±0.114)]; 18th [(P4 (1.116±0.144), C(3.409±0.137), E3(3.043±0.123)] and 23rd week of gestation [(P4(1.36±0.153), C(1.936±0.11), E3(2.657±0.07)]. Estrone sulphate levels appeared to increase progressively throughout the second trimester [from 1.103±0.03 to 2.244±0.09]. CONCLUSION: The 18th week of gestation seems to constitute a very important week during foetal adrenal development, and the analysis of the main hormones involved in foetal development, provided more precise information regarding the proper functioning of the foetal unit and foetal development.


Asunto(s)
Desarrollo Fetal , Segundo Trimestre del Embarazo/metabolismo , Adulto , Estriol/metabolismo , Estrona/análogos & derivados , Estrona/metabolismo , Femenino , Humanos , Hidrocortisona/metabolismo , Estudios Longitudinales , Embarazo , Progesterona/metabolismo , Saliva/metabolismo
4.
Entropy (Basel) ; 22(2)2020 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-33285934

RESUMEN

The expected growth of air traffic in the following decades demands the implementation of new operational concepts to avoid current limitations of the air traffic management system. This paper focuses on the strategic conflict management for four-dimensional trajectories (4DT) in free-route airspace. 4DT has been proposed as the future operational concept to manage air traffic. Thus, aircraft must fulfil temporary restrictions at specific waypoints in the airspace based on time windows. Based on the temporary restrictions, a strategic conflict management method is proposed to calculate the conflict probability of an aircraft pair (that intersects in the air) and to calculate temporary-blocking windows that quantify the time span at which an aircraft cannot depart because one conflict could occur. This methodology was applied in a case-study for an aircraft pair, including the uncertainty associated with 4DT. Moreover, a sensitivity analysis was performed to characterise the impact of wind conditions and speed control on the temporary-blocking windows. The results concluded that it is feasible to propose 4DT strategic de-confliction based on temporary-blocking windows. Although, uncertainty variables such as wind and speed control impact on the conflict probability and the size of the temporary-blocking windows.

5.
Entropy (Basel) ; 21(1)2019 Jan 19.
Artículo en Inglés | MEDLINE | ID: mdl-33266807

RESUMEN

A software bug is characterized by its attributes. Various prediction models have been developed using these attributes to enhance the quality of software products. The reporting of bugs leads to high irregular patterns. The repository size is also increasing with enormous rate, resulting in uncertainty and irregularities. These uncertainty and irregularities are termed as veracity in the context of big data. In order to quantify these irregular and uncertain patterns, the authors have appliedentropy-based measures of the terms reported in the summary and the comments submitted by the users. Both uncertainties and irregular patterns have been taken care of byentropy-based measures. In this paper, the authors considered that the bug fixing process does not only depend upon the calendar time, testing effort and testing coverage, but it also depends on the bug summary description and comments. The paper proposed bug dependency-based mathematical models by considering the summary description of bugs and comments submitted by users in terms of the entropy-based measures. The models were validated on different Eclipse project products. The models proposed in the literature have different types of growth curves. The models mainly follow exponential, S-shaped or mixtures of both types of curves. In this paper, the proposed models were compared with the modelsfollowingexponential, S-shaped and mixtures of both types of curves.

6.
Gac Med Mex ; 153(6): 662-671, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-29206822

RESUMEN

OBJECTIVE: To analyze the type of injuries and the characteristics and geographical distribution of road accidents where motorcycles were involved in Mexico. METHODS: A descriptive analysis of second-hand information sources was conducted, including the number of accidents (N = 41,881), total number of injured people (N = 13,916) and medical expenses (N = 9,111) associated to motorcycle accidents during 2014. RESULTS: Motorcycles represent 13.14% of the total number of deaths in road accidents in Mexico, and the Southeast region of Mexico registers the highest proportion of fatal injuries. Of the total number of motorcycles, 1.84% (95% confidence interval [CI]: 1.83-1.86) were involved in a collision. 3.64 (95% CI: 3.39-3.89) people died and 105.5 (95% CI: 104.1-106.8) were injured in every 10,000. Out of the total number of injuries, 76.6% were male and 53.74% were women. 55.1% of deaths were caused by intracranial trauma. Only 16.6% wore a helmet at the time of the accident, and those not wearing a helmet had a 2.11 (odds ratio [OR]: 2.1; CI 95%: 1.8-2.4) higher chance of head injury. Regarding the severity of the crash, those occurred in suburban areas (OR: 6.58; CI 95%: 5.69-7.60), in unpaved surfaces (OR: 4.13; CI 95%: 3.04-5.61), after low alcohol consumption (OR: 1.89; CI 95%: 1.46-2.44), at night (OR: 2.24; CI 95%: 1.95-2.57) and on weekends (OR: 1.65; CI 95%: 1.44-1.90), had the highest chance of turning into a fatal accident. CONCLUSIONS: In spite of the progress made in terms of road safety, motorcycle accidents are still increasing, and the use of a helmet is still proportionally low. More information on these groups and risk factors needs to be available so people are better informed. Also, regulations need improvements regarding the use of security equipment like helmets in order to reduce injuries and fatal accidents.


Asunto(s)
Accidentes de Tránsito/estadística & datos numéricos , Traumatismos Craneocerebrales/epidemiología , Motocicletas/estadística & datos numéricos , Heridas y Lesiones/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Preescolar , Traumatismos Craneocerebrales/mortalidad , Femenino , Dispositivos de Protección de la Cabeza/estadística & datos numéricos , Humanos , Lactante , Masculino , México/epidemiología , Persona de Mediana Edad , Factores de Riesgo , Heridas y Lesiones/mortalidad , Adulto Joven
7.
Anesth Analg ; 122(5): 1370-6, 2016 May.
Artículo en Inglés | MEDLINE | ID: mdl-26859874

RESUMEN

BACKGROUND: Ultralow doses of naloxone, an opioid and toll-like receptor 4 antagonist, blocked remifentanil-induced hyperalgesia and the associated increase in the minimum alveolar concentration (MAC), but not tolerance. The aim was to determine the effects of the toll-like receptor 4 antagonist, ibudilast, on the MAC in the rat and how it might prevent the effects of remifentanil. METHODS: Male Wistar rats were randomly allocated to 5 treatment groups (n = 7 per group): 10 mg/kg ibudilast intraperitoneally, 240 µg/kg/h remifentanil IV, ibudilast plus remifentanil, remifentanil plus naloxone IV, or saline. The sevoflurane MAC was determined 3 times in every rat and every day (days 0, 2, and 4): baseline (MAC-A) and 2 further determinations were made after treatments, 1.5 hours apart (MAC-B and MAC-C). RESULTS: A reduction in baseline MAC was produced on day 0 by ibudilast, remifentanil, remifentanil plus ibudilast, remifentanil plus naloxone (P < 0.01), but not saline. Similar effects were found on days 2 and 4. A tolerance to remifentanil was found on days 0, 2, and 4, which neither ibudilast nor naloxone prevented. The MAC increase produced by remifentanil on day 4 (P = 0.001) was prevented by either ibudilast or naloxone. CONCLUSIONS: Ibudilast, besides reducing the MAC, prevented the delayed increase in baseline MAC produced by remifentanil but not the increase in MAC caused by tolerance to remifentanil.


Asunto(s)
Analgésicos Opioides/farmacología , Anestésicos por Inhalación/farmacología , Conducta Animal/efectos de los fármacos , Éteres Metílicos/farmacología , Umbral del Dolor/efectos de los fármacos , Piperidinas/farmacología , Piridinas/farmacología , Receptor Toll-Like 4/antagonistas & inhibidores , Administración por Inhalación , Analgésicos Opioides/administración & dosificación , Analgésicos Opioides/toxicidad , Anestésicos por Inhalación/administración & dosificación , Animales , Interacciones Farmacológicas , Tolerancia a Medicamentos , Inyecciones Intraperitoneales , Inyecciones Intravenosas , Masculino , Éteres Metílicos/administración & dosificación , Naloxona/farmacología , Antagonistas de Narcóticos/farmacología , Piperidinas/administración & dosificación , Piperidinas/toxicidad , Piridinas/administración & dosificación , Ratas Wistar , Remifentanilo , Sevoflurano , Factores de Tiempo
8.
Plant Physiol ; 166(4): 1972-84, 2014 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-25315603

RESUMEN

Nitric oxide (NO) is a unique reactive nitrogen molecule with an array of signaling functions that modulates plant developmental processes and stress responses. To explore the mechanisms by which NO modulates root development, we used a pharmacological approach and NO-deficient mutants to unravel the role of NO in establishing auxin distribution patterns necessary for stem cell niche homeostasis. Using the NO synthase inhibitor and Arabidopsis (Arabidopsis thaliana) NO biosynthesis mutants (nitric oxide-associated1 [noa1], nitrate reductase1 [nia1] and nia2, and nia1 nia2 noa1), we show that depletion of NO in noa1 reduces primary root elongation and increases flavonol accumulation consistent with elevated reactive oxygen species levels. The elevated flavonols are required for the growth effect, because the transparent testa4 mutation reverses the noa1 mutant root elongation phenotype. In addition, noa1 and nia1 nia2 noa1 NO-deficient mutant roots display small root meristems with abnormal divisions. Concomitantly, auxin biosynthesis, transport, and signaling are perturbed. We further show that NO accumulates in cortex/endodermis stem cells and their precursor cells. In endodermal and cortical cells, the noa1 mutant acts synergistically to the effect of the wuschel-related homeobox5 mutation on the proximal meristem, suggesting that NO could play an important role in regulating stem cell decisions, which has been reported in animals.


Asunto(s)
Arabidopsis/fisiología , Ácidos Indolacéticos/metabolismo , Óxido Nítrico/metabolismo , Reguladores del Crecimiento de las Plantas/metabolismo , Nicho de Células Madre/fisiología , Transporte Biológico , Flavonoles/metabolismo , Homeostasis , Meristema/fisiología , Mutación , Nitratos/metabolismo , Raíces de Plantas/fisiología , Tallos de la Planta/fisiología , Especies Reactivas de Oxígeno/metabolismo , Transducción de Señal
9.
J Exp Bot ; 66(10): 2857-68, 2015 May.
Artículo en Inglés | MEDLINE | ID: mdl-25954048

RESUMEN

During the past two decades, nitric oxide (NO) has evolved from a mere gaseous free radical to become a new messenger in plant biology with an important role in a plethora of physiological processes. This molecule is involved in the regulation of plant growth and development, pathogen defence and abiotic stress responses, and in most cases this is achieved through its interaction with phytohormones. Understanding the role of plant growth regulators is essential to elucidate how plants activate the appropriate set of responses to a particular developmental stage or a particular stress. The first task to achieve this goal is the identification of molecular targets, especially those involved in the regulation of the crosstalk. The nature of NO targets in these growth and development processes and stress responses remains poorly described. Currently, the molecular mechanisms underlying the effects of NO in these processes and their interaction with other plant hormones are beginning to unravel. In this review, we made a compilation of the described interactions between NO and phytohormones during early plant developmental processes (i.e. seed dormancy and germination, hypocotyl elongation and root development).


Asunto(s)
Regulación de la Expresión Génica de las Plantas , Óxido Nítrico/metabolismo , Desarrollo de la Planta , Reguladores del Crecimiento de las Plantas/genética , Plantas/genética , Reguladores del Crecimiento de las Plantas/metabolismo , Plantas/metabolismo , Receptor Cross-Talk
10.
Stat Appl Genet Mol Biol ; 13(1): 49-65, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24317791

RESUMEN

DNA microarray experiments require the use of multiple hypothesis testing procedures because thousands of hypotheses are simultaneously tested. We deal with this problem from a Bayesian decision theory perspective. We propose a decision criterion based on an estimation of the number of false null hypotheses (FNH), taking as an error measure the proportion of the posterior expected number of false positives with respect to the estimated number of true null hypotheses. The methodology is applied to a Gaussian model when testing bilateral hypotheses. The procedure is illustrated with both simulated and real data examples and the results are compared to those obtained by the Bayes rule when an additive loss function is considered for each joint action and the generalized loss 0-1 function for each individual action. Our procedure significantly reduced the percentage of false negatives whereas the percentage of false positives remains at an acceptable level.


Asunto(s)
Perfilación de la Expresión Génica , Análisis de Secuencia por Matrices de Oligonucleótidos , Algoritmos , Teorema de Bayes , Estudios de Casos y Controles , Neoplasias del Colon/genética , Neoplasias del Colon/metabolismo , Interpretación Estadística de Datos , Árboles de Decisión , Humanos , Modelos Estadísticos , Transcriptoma
11.
Plant Cell ; 23(2): 641-60, 2011 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-21357490

RESUMEN

The integration of cell division in root growth and development requires mediation of developmental and physiological signals through regulation of cyclin-dependent kinase activity. Cells within the pericycle form de novo lateral root meristems, and D-type cyclins (CYCD), as regulators of the G1-to-S phase cell cycle transition, are anticipated to play a role. Here, we show that the D-type cyclin protein CYCD2;1 is nuclear in Arabidopsis thaliana root cells, with the highest concentration in apical and lateral meristems. Loss of CYCD2;1 has a marginal effect on unstimulated lateral root density, but CYCD2;1 is rate-limiting for the response to low levels of exogenous auxin. However, while CYCD2;1 expression requires sucrose, it does not respond to auxin. The protein Inhibitor-Interactor of CDK/Kip Related Protein2 (ICK2/KRP2), which interacts with CYCD2;1, inhibits lateral root formation, and ick2/krp2 mutants show increased lateral root density. ICK2/KRP2 can modulate the nuclear levels of CYCD2;1, and since auxin reduces ICK2/KRP2 protein levels, it affects both activity and cellular distribution of CYCD2;1. Hence, as ICK2/KRP2 levels decrease, the increase in lateral root density depends on CYCD2;1, irrespective of ICK2/CYCD2;1 nuclear localization. We propose that ICK2/KRP2 restrains root ramification by maintaining CYCD2;1 inactive and that this modulates pericycle responses to auxin fluctuations.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/genética , Proteínas de Ciclo Celular/metabolismo , Ciclinas/metabolismo , Ácidos Indolacéticos/farmacología , Raíces de Plantas/crecimiento & desarrollo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Ciclo Celular , Proteínas de Ciclo Celular/genética , Núcleo Celular/genética , Ciclinas/genética , Regulación de la Expresión Génica de las Plantas , Mutación , Raíces de Plantas/genética , Raíces de Plantas/metabolismo , Complejo de la Endopetidasa Proteasomal/metabolismo
12.
Proc Natl Acad Sci U S A ; 108(45): 18506-11, 2011 Nov 08.
Artículo en Inglés | MEDLINE | ID: mdl-22021439

RESUMEN

Nitric oxide (NO) is considered a key regulator of plant developmental processes and defense, although the mechanism and direct targets of NO action remain largely unknown. We used phenotypic, cellular, and genetic analyses in Arabidopsis thaliana to explore the role of NO in regulating primary root growth and auxin transport. Treatment with the NO donors S-nitroso-N-acetylpenicillamine, sodium nitroprusside, and S-nitrosoglutathione reduces cell division, affecting the distribution of mitotic cells and meristem size by reducing cell size and number compared with NO depletion by 2-(4-carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO). Interestingly, genetic backgrounds in which the endogenous NO levels are enhanced [chlorophyll a/b binding protein underexpressed 1/NO overproducer 1 (cue1/nox1) mirror this response, together with an increased cell differentiation phenotype. Because of the importance of auxin distribution in regulating primary root growth, we analyzed auxin-dependent response after altering NO levels. Both elevated NO supply and the NO-overproducing Arabidopsis mutant cue1/nox1 exhibit reduced expression of the auxin reporter markers DR5pro:GUS/GFP. These effects were accompanied by a reduction in auxin transport in primary roots. NO application and the cue1/nox1 mutation caused decreased PIN-FORMED 1 (PIN1)-GFP fluorescence in a proteasome-independent manner. Remarkably, the cue1/nox1-mutant root phenotypes resemble those of pin1 mutants. The use of both chemical treatments and mutants with altered NO levels demonstrates that high levels of NO reduce auxin transport and response by a PIN1-dependent mechanism, and root meristem activity is reduced concomitantly.


Asunto(s)
Proteínas de Arabidopsis/fisiología , Ácidos Indolacéticos/metabolismo , Proteínas de Transporte de Membrana/fisiología , Meristema/crecimiento & desarrollo , Óxido Nítrico/fisiología , Raíces de Plantas/crecimiento & desarrollo , Arabidopsis/crecimiento & desarrollo , Transporte Biológico , Donantes de Óxido Nítrico/administración & dosificación , Nitroprusiato/administración & dosificación , Reacción en Cadena en Tiempo Real de la Polimerasa
14.
Sci Rep ; 14(1): 17683, 2024 Jul 26.
Artículo en Inglés | MEDLINE | ID: mdl-39085249

RESUMEN

In the digitization era, the battery consumption factor plays a vital role for the devices that operate Android software, expecting them to deliver high performance and good maintainability.The study aims to analyze the Android-specific code smells, their impact on battery consumption, and the formulation of a mathematical model concerning static code metrics hampered by the code smells. We studied the impact on battery consumption by three Android-specific code smells, namely: No Low Memory Resolver (NLMR), Slow Loop (SL) and Unclosed Closable, considering 4,165 classes of 16 Android applications. We used a rule-based classification method that aids the refactoring ideology. Subsequently, multi-linear regression (MLR) modeling is used to evaluate battery usage against the software metrics of smelly code instances. Moreover, it was possible to devise a correlation for the software metric influenced by battery consumption and rule-based classifiers. The outcome confirms that the refactoring of the considered code smells minimizes the battery consumption levels. The refactoring method accounts for an accuracy of 87.47% cumulatively. The applied MLR model has an R-square value of 0.76 for NLMR and 0.668 for SL, respectively. This study can guide the developers towards a complete package for the focused development life cycle of Android code, helping them minimize smartphone battery consumption and use the saved battery lives for other operations, contributing to the green energy revolution in mobile devices.

16.
Animals (Basel) ; 13(16)2023 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-37627374

RESUMEN

Ensuring the effective management of every rhinoceros population is crucial for securing a future for the species, especially considering the escalating global threat of poaching and the challenges faced in captive breeding programs for this endangered species. Steroid hormones play pivotal roles in regulating diverse biological processes, making fecal hormonal determinations a valuable non-invasive tool for monitoring adrenal and gonadal endocrinologies and assessing reproductive status, particularly in endangered species. The purpose of this study was to develop a statistical model for predicting the sex of white rhinoceroses using hormonal determinations obtained from a single fecal sample. To achieve this, 562 fecal samples from 15 individuals of the Ceratotherium simum species were collected, and enzyme immunoassays were conducted to determine the concentrations of fecal cortisol, progesterone, estrone, and testosterone metabolites. The biological validation of the method provided an impressive accuracy rate of nearly 80% in predicting the sex of hypothetically unknown white rhinoceroses. Implementing this statistical model for sex identification in white rhinoceroses would yield significant benefits, including a better understanding of the structure and dynamics of wild populations. Additionally, it would enhance conservation management efforts aimed at protecting this endangered species. By utilizing this innovative approach, we can contribute to the preservation and long-term survival of white rhinoceros populations.

17.
Sci Total Environ ; 861: 160534, 2023 Feb 25.
Artículo en Inglés | MEDLINE | ID: mdl-36574545

RESUMEN

The escape behaviour, measured as flight initiation distance (FID; the distance at which individuals take flight when approached by a potential predator, usually a human in the study systems), is a measure widely used to study fearfulness and risk-taking in animals. Previous studies have shown significant differences in the escape behaviour of birds inhabiting cemeteries and urban parks in European cities, where birds seem to be shyer in the latter. We collected a regional dataset of the FID of birds inhabiting cemeteries and parks across Latin America in peri-urban, suburban and urban parks and cemeteries. FIDs were recorded for eighty-one bird species. Mean species-specific FIDs ranged from 1.9 to 19.7 m for species with at least two observations (fifty-seven species). Using Bayesian regression modelling and controlling for the phylogenetic relatedness of the FID among bird species and city and country, we found that, in contrast to a recent publication from Europe, birds escape earlier in cemeteries than parks in the studied Latin American cities. FIDs were also significantly shorter in urban areas than in peri-urban areas and in areas with higher human density. Our results indicate that some idiosyncratic patterns in animal fearfulness towards humans may emerge among different geographic regions, highlighting difficulties with scaling up and application of regional findings to other ecosystems and world regions. Such differences could be associated with intrinsic differences between the pool of bird species from temperate European and mostly tropical Latin American cities, characterized by different evolutionary histories, but also with differences in the historical process of urbanization.


Asunto(s)
Cementerios , Ecosistema , Animales , Humanos , América Latina , Filogenia , Parques Recreativos , Teorema de Bayes , Aves , Ciudades , Europa (Continente)
18.
Proc Natl Acad Sci U S A ; 106(52): 22528-33, 2009 Dec 29.
Artículo en Inglés | MEDLINE | ID: mdl-20018777

RESUMEN

Root cell division occurs primarily in the apical meristem, from which cells are displaced into the basal meristem, where division decreases and cell length increases before the final differentiation zone. The organization of the root in concentric files implies coordinated division and differentiation of cell types, including the xylem pole pericycle cells, which uniquely can resume division to initiate lateral roots (LR). Here, we show that D-type cyclin CYCD4;1 is expressed in meristematic pericycle protoxylem poles and is required for normal LR density. Cycd4;1 mutants also show a displacement of the apical/basal meristem boundary in the pericycle and longer pericycle basal meristem cells, whereas other cell layers and overall meristem size and root growth are unaffected. Auxin is proposed to separately prepattern and stimulate LR initiation. Stimulation is unimpaired in cycd4;1, suggesting CYCD4;1 requirement for normal spacing but not initiation. Both pericycle cell length and LR density phenotypes of cycd4;1 are rescued by low concentrations of applied auxin, suggesting that the basal meristem has a role in determining LR density. We further show CYCD4;1 is rate-limiting for sucrose-dependent LR formation, since CYCD4;1 expression is sucrose-dependent and wild-type roots fully phenocopy cycd4;1 in sucrose absence. We conclude that CYCD4;1 links meristem pericycle cell behavior to LR density consistent with a basal meristem prepatterning model and that D-type cyclins can confer division potential of defined cell types through cell-specific expression patterns.


Asunto(s)
Proteínas de Arabidopsis/metabolismo , Arabidopsis/crecimiento & desarrollo , Arabidopsis/metabolismo , Ciclinas/metabolismo , Arabidopsis/genética , Proteínas de Arabidopsis/genética , Secuencia de Bases , Tipificación del Cuerpo , Ciclinas/genética , ADN de Plantas/genética , Regulación del Desarrollo de la Expresión Génica , Regulación de la Expresión Génica de las Plantas , Genes de Plantas , Ácidos Indolacéticos/farmacología , Meristema/crecimiento & desarrollo , Meristema/metabolismo , Modelos Biológicos , Mutación , Fenotipo , Raíces de Plantas/efectos de los fármacos , Raíces de Plantas/crecimiento & desarrollo , Raíces de Plantas/metabolismo , Plantas Modificadas Genéticamente , Regiones Promotoras Genéticas , Sacarosa/metabolismo
19.
Plant Physiol ; 152(1): 133-50, 2010 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-19889877

RESUMEN

The functional protein phosphatase type 2C from beechnut (Fagus sylvatica; FsPP2C1) was a negative regulator of abscisic acid (ABA) signaling in seeds. In this report, to get deeper insight on FsPP2C1 function, we aim to identify PP2C-interacting partners. Two closely related members (PYL8/RCAR3 and PYL7/RCAR2) of the Arabidopsis (Arabidopsis thaliana) BetV I family were shown to bind FsPP2C1 in a yeast two-hybrid screening and in an ABA-independent manner. By transient expression of FsPP2C1 and PYL8/RCAR3 in epidermal onion (Allium cepa) cells and agroinfiltration in tobacco (Nicotiana benthamiana) as green fluorescent protein fusion proteins, we obtained evidence supporting the subcellular localization of both proteins mainly in the nucleus and in both the cytosol and the nucleus, respectively. The in planta interaction of both proteins in tobacco cells by bimolecular fluorescence complementation assays resulted in a specific nuclear colocalization of this interaction. Constitutive overexpression of PYL8/RCAR3 confers ABA hypersensitivity in Arabidopsis seeds and, consequently, an enhanced degree of seed dormancy. Additionally, transgenic 35S:PYL8/RCAR3 plants are unable to germinate under low concentrations of mannitol, NaCl, or paclobutrazol, which are not inhibiting conditions to the wild type. In vegetative tissues, Arabidopsis PYL8/RCAR3 transgenic plants show ABA-resistant drought response and a strong inhibition of early root growth. These phenotypes are strengthened at the molecular level with the enhanced induction of several ABA response genes. Both seed and vegetative phenotypes of Arabidopsis 35S:PYL8/RCAR3 plants are opposite those of 35S:FsPP2C1 plants. Finally, double transgenic plants confirm the role of PYL8/RCAR3 by antagonizing FsPP2C1 function and demonstrating that PYL8/RCAR3 positively regulates ABA signaling during germination and abiotic stress responses.


Asunto(s)
Ácido Abscísico/metabolismo , Fagus/metabolismo , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Proteínas Nucleares/metabolismo , Proteínas de Plantas/metabolismo , Secuencia de Aminoácidos , Fagus/genética , Regulación de la Expresión Génica de las Plantas , Péptidos y Proteínas de Señalización Intracelular/genética , Proteínas Nucleares/genética , Filogenia , Hojas de la Planta/citología , Hojas de la Planta/metabolismo , Proteínas de Plantas/genética , Plantas Modificadas Genéticamente , Semillas/metabolismo , Transducción de Señal/fisiología , Estrés Fisiológico , Nicotiana , Técnicas del Sistema de Dos Híbridos
20.
Front Plant Sci ; 12: 630792, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34122465

RESUMEN

Hormone patterns tailor cell fate decisions during plant organ formation. Among them, auxins and cytokinins are critical phytohormones during early development. Nitric oxide (NO) modulates root architecture by the control of auxin spatial patterns. However, NO involvement during the coordination of shoot organogenesis remains unclear. Here, we explore the effect of NO during shoot development by using a phenotypic, cellular, and genetic analysis in Arabidopsis thaliana and get new insights into the characterization of NO-mediated leaf-related phenotypes. NO homeostasis mutants are impaired in several shoot architectural parameters, including phyllotactic patterns, inflorescence stem elongation, silique production, leaf number, and margin. Auxin distribution is a key feature for tissue differentiation and need to be controlled at different levels (i.e., synthesis, transport, and degradation mechanisms). The phenotypes resulting from the introduction of the cue1 mutation in the axr1 auxin resistant and pin1 backgrounds exacerbate the relationship between NO and auxins. Using the auxin reporter DR5:GUS, we observed an increase in auxin maxima under NO-deficient mutant backgrounds and NO scavenging, pointing to NO-ASSOCIATED 1 (NOA1) as the main player related to NO production in this process. Furthermore, polar auxin transport is mainly regulated by PIN-FORMED 1 (PIN1), which controls the flow along leaf margin and venations. Analysis of PIN1 protein levels shows that NO controls its accumulation during leaf development, impacting the auxin mediated mechanism of leaf building. With these findings, we also provide evidence for the NO opposite effects to determine root and shoot architecture, in terms of PIN1 accumulation under NO overproduction.

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