Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 56
Filtrar
Mais filtros

Base de dados
Tipo de documento
Intervalo de ano de publicação
1.
Behav Brain Sci ; 47: e138, 2024 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-38934458

RESUMO

Elizabeth Spelke's What Babies Know is a scholarly presentation of core knowledge theory and a masterful compendium of empirical evidence that supports it. Unfortunately, Spelke's principal theoretical assumption is that core knowledge is simply the innate product of cognitive evolution. As such, her theory fails to explicate the developmental mechanisms underlying the emergence of the cognitive systems on which that knowledge depends.


Assuntos
Desenvolvimento Infantil , Cognição , Humanos , Lactente , Desenvolvimento Infantil/fisiologia , Cognição/fisiologia , Conhecimento
2.
Behav Brain Sci ; 46: e220, 2023 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-37695006

RESUMO

Polygenic scores cannot elucidate the mechanisms that produce behavioral phenotypes (including "intelligence"). Therefore, they are unlikely to yield helpful interventions. Moreover, they are poor predictors of individuals' developmental outcomes. Burt's critique is well-supported by the details of molecular biology. Specifically, experiences affect epigenetic factors that influence phenotypes via how the genome functions, a fact that lends support to Burt's conclusions.


Assuntos
Epigênese Genética , Inteligência , Humanos
3.
Dev Sci ; 21(4): e12613, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29143410

RESUMO

Some cognitive abilities exhibit reliable gender differences, with females outperforming males in specific aspects of verbal ability, and males showing an advantage on certain spatial tasks. Among these cognitive gender differences, differences in mental rotation are the most robust, and appear to be present even in infants. A large body of animal research suggests that gonadal hormones, particularly testosterone, during early development could contribute to this gender difference in mental rotation. Also, substantial evidence supports an influence of socialization on mental rotation performance. The present study investigated the relationship of two types of factors, early postnatal testosterone exposure and parental attitudes about gender, to mental rotation performance in 61 healthy infants (29 males, 32 females). We measured salivary testosterone at two time points: 1-2.5 months of age and 5-6 months of age. Infants' mental rotation performance and parents' attitudes about gender were assessed at 5-6 months of age. As predicted, testosterone concentrations were significantly higher in boys than girls in early infancy (d = 0.54), and boys performed significantly better than girls on mental rotation (d = 0.64). A significant positive correlation between testosterone at age 1-2.5 months and mental rotation was found only in boys (r = 0.50, p = .01). A significant negative correlation between parents' gender-stereotypical attitudes and mental rotation performance was found only in girls (r = -.57, p = .002). These findings suggest that the early postnatal testosterone surge (also known as "mini-puberty") may have organizational influences on mental rotation performance in boys, and that parents may influence their daughters' mental rotation abilities beginning very early in life.


Assuntos
Cognição , Pais/psicologia , Feminino , Humanos , Lactente , Masculino , Fatores Sexuais , Estereotipagem , Testosterona/análise
4.
Biomacromolecules ; 17(3): 710-22, 2016 Mar 14.
Artigo em Inglês | MEDLINE | ID: mdl-26771518

RESUMO

A pressing need exists for autoimmune disease therapies that act in an antigen-specific manner while avoiding global immunosuppression. Multivalent soluble antigen arrays (SAgAPLP:LABL), designed to induce tolerance to a specific multiple sclerosis autoantigen, consist of a flexible hyaluronic acid (HA) polymer backbone cografted with multiple copies of autoantigen peptide (PLP) and cell adhesion inhibitor peptide (LABL). Previous in vivo studies revealed copresentation of both signals on HA was necessary for therapeutic efficacy. To elucidate therapeutic cellular mechanisms, in vitro studies were performed in a model B cell system to evaluate binding and specificity. Compared to HA and HA arrays containing only grafted PLP or LABL, SAgAPLP:LABL displaying both PLP and LABL exhibited greatly enhanced B cell binding. Furthermore, the binding avidity of SAgAPLP:LABL was primarily driven by the PLP antigen, determined via flow cytometry competitive dissociation studies. Fluorescence microscopy showed SAgAPLP:LABL induced mature receptor clustering that was faster than other HA arrays with only one type of grafted peptide. SAgAPLP:LABL molecules also reduced and inhibited IgM-stimulated signaling as discerned by a calcium flux assay. The molecular mechanisms of enhanced antigen-specific binding, mature receptor clustering, and dampened signaling observed in B cells may contribute to SAgAPLP:LABL therapeutic efficacy.


Assuntos
Autoantígenos/imunologia , Antígeno-1 Associado à Função Linfocitária/imunologia , Autoantígenos/química , Linfócitos B/imunologia , Linhagem Celular , Humanos , Ácido Hialurônico/química , Esclerose Múltipla/imunologia , Análise Serial de Proteínas , Transdução de Sinais
5.
Anal Bioanal Chem ; 408(1): 49-65, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26446898

RESUMO

The number and capability of explosives detection and analysis methods have increased dramatically since publication of the Analytical and Bioanalytical Chemistry special issue devoted to Explosives Analysis [Moore DS, Goodpaster JV, Anal Bioanal Chem 395:245-246, 2009]. Here we review and critically evaluate the latest (the past five years) important advances in explosives detection, with details of the improvements over previous methods, and suggest possible avenues towards further advances in, e.g., stand-off distance, detection limit, selectivity, and penetration through camouflage or packaging. The review consists of two parts. Part I discussed methods based on animals, chemicals (including colorimetry, molecularly imprinted polymers, electrochemistry, and immunochemistry), ions (both ion-mobility spectrometry and mass spectrometry), and mechanical devices. This part, Part II, will review methods based on photons, from very energetic photons including X-rays and gamma rays down to the terahertz range, and neutrons.

6.
Anal Bioanal Chem ; 408(1): 35-47, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26462922

RESUMO

The number and capability of explosives detection and analysis methods have increased substantially since the publication of the Analytical and Bioanalytical Chemistry special issue devoted to Explosives Analysis (Moore and Goodpaster, Anal Bioanal Chem 395(2):245-246, 2009). Here we review and critically evaluate the latest (the past five years) important advances in explosives detection, with details of the improvements over previous methods, and suggest possible avenues towards further advances in, e.g., stand-off distance, detection limit, selectivity, and penetration through camouflage or packaging. The review consists of two parts. This part, Part I, reviews methods based on animals, chemicals (including colorimetry, molecularly imprinted polymers, electrochemistry, and immunochemistry), ions (both ion-mobility spectrometry and mass spectrometry), and mechanical devices. Part II will review methods based on photons, from very energetic photons including X-rays and gamma rays down to the terahertz range, and neutrons.


Assuntos
Técnicas de Química Analítica/métodos , Substâncias Explosivas/análise , Animais , Técnicas de Química Analítica/instrumentação , Técnicas de Química Analítica/tendências
7.
Proc Natl Acad Sci U S A ; 110(36): 14540-5, 2013 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-23964124

RESUMO

Although the mineral dolomite is abundant in ancient low-temperature sedimentary systems, it is scarce in modern systems below 50 °C. Chemical mechanism(s) enhancing its formation remain an enigma because abiotic dolomite has been challenging to synthesize at low temperature in laboratory settings. Microbial enhancement of dolomite precipitation at low temperature has been reported; however, it is still unclear exactly how microorganisms influence reaction kinetics. Here we document the abiotic synthesis of low-temperature dolomite in laboratory experiments and constrain possible mechanisms for dolomite formation. Ancient and modern seawater solution compositions, with identical pH and pCO2, were used to precipitate an ordered, stoichiometric dolomite phase at 30 °C in as few as 20 d. Mg-rich phases nucleate exclusively on carboxylated polystyrene spheres along with calcite, whereas aragonite forms in solution via homogeneous nucleation. We infer that Mg ions are complexed and dewatered by surface-bound carboxyl groups, thus decreasing the energy required for carbonation. These results indicate that natural surfaces, including organic matter and microbial biomass, possessing a high density of carboxyl groups may be a mechanism by which ordered dolomite nuclei form. Although environments rich in organic matter may be of interest, our data suggest that sharp biogeochemical interfaces that promote microbial death, as well as those with high salinity may, in part, control carboxyl-group density on organic carbon surfaces, consistent with origin of dolomites from microbial biofilms, as well as hypersaline and mixing zone environments.


Assuntos
Carbonato de Cálcio/química , Microbiologia Ambiental , Magnésio/química , Temperatura , Bactérias/crescimento & desenvolvimento , Bactérias/metabolismo , Reatores Biológicos/microbiologia , Carbonato de Cálcio/metabolismo , Dióxido de Carbono/metabolismo , Precipitação Química , Concentração de Íons de Hidrogênio , Magnésio/metabolismo , Microscopia Eletrônica de Varredura , Modelos Químicos , Salinidade , Água do Mar/microbiologia , Espectrometria por Raios X , Propriedades de Superfície , Difração de Raios X
8.
Behav Anal ; 39(2): 243-258, 2016 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-31976975

RESUMO

The developmental systems approach is a perspective that has been adopted by increasing numbers of developmental scientists since it emerged in the twentieth century. The overview presented in this paper makes clear that proponents of this approach and proponents of modern behavior analysis should be natural allies. Despite some distinctions between the two schools of thought, the essential ideas associated with each are compatible with the other; in particular, scientists in both camps work to analyze the provenance of behavior and recognize the central role that contextual factors play in behavioral expression.

9.
Opt Lett ; 40(19): 4560-2, 2015 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-26421581

RESUMO

Cavity-enhanced spectroscopy is a sensitive optical absorption technique but one where the practical applications have been limited to studying small wavelength ranges. This Letter shows that wideband operation can be achieved by combining techniques usually reserved for the communications community with that of cavity-enhanced spectroscopy, producing a multiplexed real-time cavity-enhanced spectrometer. We use multiple collinear laser sources operating asynchronously and simultaneously while being detected on a single photodetector. This is synonymous with radio frequency (RF) cellular systems in which signals are detected on a single antenna but decoded uniquely. Here, we demonstrate results with spectra of methyl salicylate and show parts-per-billion per root hertz sensitivity measured in real-time.

10.
Opt Express ; 22(9): 10519-34, 2014 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-24921754

RESUMO

Optical cavity enhancement is a highly desirable process to make sensitive direct-absorption spectroscopic measurements of unknown substances, such as explosives, illicit material, or other species of interest. This paper reports advancements in the development of real-time cavity ringdown spectroscopy over a wide-bandwidth, with the aim to make headspace measurements of molecules at trace levels. We report results of two pulsed quantum cascade systems operating between (1200 to 1320)cm(-1) and (1316 to 1613)cm(-1) that measure the headspace of nitromethane, acetonitrile, acetone, and nitroglycerin, where the spectra are obtained in less than four seconds and contain at least 150,000 spectral wavelength datapoints.

11.
J Phys Chem A ; 118(14): 2559-67, 2014 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-24628136

RESUMO

Initiation of the shock driven chemical reactions and detonation of nitromethane (NM) can be sensitized by the addition of a weak base; however, the chemical mechanism by which sensitization occurs remains unclear. We investigated the shock driven chemical reaction in NM and in NM sensitized with diethylenetriamine (DETA), using a sustained 300 ps shock driven by a chirped Ti:sapphire laser. We measured the solutions' visible transient absorption spectra and measured interface particle and shock velocities of the nitromethane solutions using ultrafast dynamic ellipsometry. We found there to be a volume-increasing reaction that takes place around interface particle velocity up = 2.4 km/s and up = 2.2 km/s for neat NM and NM with 5% DETA, respectively. The rate at which transient absorption increases is similar in all mixtures, but with decreasing induction times for solutions with increasing DETA concentrations. This result supports the hypothesis that the chemical reaction mechanisms for shocked NM and NM with DETA are the same. Data from shocked NM are compared to literature experimental and theoretical data.

12.
Front Psychol ; 15: 1415651, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39346501

RESUMO

Mental rotation (MR) is an important feature of spatial cognition invoking mental imagery of an object's appearance when viewed from a new orientation. Prior studies have revealed evidence of MR in infants, including a sex difference similar to that detected in older populations. Some of these studies used visual habituation methods whereby infants were familiarized with an object rotating through a 240° angle, followed by test trials showing either the habituation object or a mirror image object rotating through the previously unseen 120° angle. Significantly longer looking at either of these objects was taken to reflect infants' ability to recognize the habituation object even when seen from a novel viewpoint, suggesting the capacity for MR. However, these infants' responses could, in theory, be explained with reference to perceptual discrimination rather than MR, because the views of the habituation and test objects were very similar in some video frames. In the current study, we observed a diverse population of 5-month-olds (24 females, 24 males) for evidence of MR through 30° of arc. In this more challenging test, our stimuli left a 30° gap angle between critical video frames representing the habituation and test objects. Consistent with earlier reports, we found that relative to female infants, male infants looked significantly longer at the mirror image test stimulus immediately following habituation. These results add to an emerging consensus that some young infants are capable of MR, and that male and female infants on average behave differently in this type of MR task.

13.
J Phys Chem A ; 117(29): 6158-63, 2013 Jul 25.
Artigo em Inglês | MEDLINE | ID: mdl-23656314

RESUMO

Laser shock Hugoniot data were obtained using ultrafast dynamic ellipsometry (UDE) for both nonideal (ethanol/water solutions with mole percent χ(ethanol) = 0%, 3.4%, 5.4%, 7.5%, 9.7%, 11%, 18%, 33%, 56%, 100%) and ideal liquid mixtures (toluene/fluorobenzene solutions with mole percent χ(toluene) = 0%, 26.0%, 49.1%, 74.9%, 100%). The shock and particle velocities obtained from the UDE data were compared to the universal liquid Hugoniot (ULH) and to literature shock (plate impact) data where available. It was found that the water UDE data fit to a ULH-form equation suggests an intercept of 1.32 km/s, lower than the literature ambient sound speed in water of 1.495 km/s (Mijakovic et al. J. Mol. Liq. 2011, 164, 66-73). Similarly, the ethanol UDE data fit to a ULH-form equation suggests an intercept of 1.45 km/s, which lies above the literature ambient sound speed in ethanol of 1.14 km/s. Both the literature plate impact and UDE Hugoniot data lie below the ULH for water. Likewise, the literature plate impact and UDE Hugoniot data lie above the ULH for ethanol. The UDE Hugoniot data for the mixtures of water and ethanol cross the predictions of the ULH near the same concentration where the sound speed reaches a maximum. In contrast, the UDE data from the ideal liquids and their mixtures are well behaved and agree with ULH predictions across the concentration range. The deviations of the nonideal ethanol/water data from the ULH suggest that complex hydrogen bonding networks in ethanol/water mixtures alter the compressibility of the mixture.

14.
Dev Psychobiol ; 55(1): 13-21, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-22711075

RESUMO

To help introduce the idea of homology into developmental psychology, this article presents some of the concepts, distinctions, and guidelines biologists and philosophers of biology have devised to study homology. Some unresolved issues related to this idea are considered as well. Because homology reflects continuity across time, developmental scientists should find this concept to be useful in the study of psychological/behavioral development, just as biologists have found it essential in the study of the evolution and development of morphological and other characteristics.


Assuntos
Comportamento/fisiologia , Evolução Biológica , Biologia do Desenvolvimento , Psicologia , Animais , Humanos
15.
Ann N Y Acad Sci ; 1529(1): 21-32, 2023 11.
Artigo em Inglês | MEDLINE | ID: mdl-37750405

RESUMO

Evolution and development are interrelated processes influenced by genomic, epigenetic, and environmental factors. Epigenetic processes serve critical roles in development and operate as intermediaries that connect the genome to the rest of the world. Therefore, it is of interest to consider the evolution of epigenetic processes. The developmental systems perspective offers a distinctive, coherent, integrative way to understand the relationships between evolution, epigenetics, development, and the effects of experienced contexts. By adopting this perspective, this paper draws attention to the role of exaptation in the evolution of epigenetics in the RNA world and addresses the role of epigenetics in the later evolution of developmental processes such as cellular differentiation, learning, and memory. In so doing, the paper considers the appearance and functions of epigenetics in evolutionary history-sketching a pathway by which epigenetic processes might have evolved via exaptation and then contributed to the later development and evolution of phenotypes.


Assuntos
Epigênese Genética , Epigenômica , Humanos , RNA , Fenótipo , Evolução Biológica
16.
Prog Biophys Mol Biol ; 178: 72-77, 2023 03.
Artigo em Inglês | MEDLINE | ID: mdl-36682588

RESUMO

In the predominately gene-centered view of 20th century biology, the relationship between genotype and phenotype was essentially a relationship between cause and effect, between a plan and a product. Abandoning the idea of genes as inherited instructions or blueprints for phenotypes raises the question of how to best account for observed phenotypic stability and variability within and across generations of a population. We argue that the processes responsible for phenotypic stability and the processes responsible for phenotypic variability are one and the same, namely, the dynamics of development. This argument proposes that stability of phenotypic form is found not because of the transmission of genotypes, genetic programs, or the transfer of internal blueprints, but because similar internal and external conditions-collectively conceptualized as resources of development-can be reliably reconstituted in each generation. Variability of phenotypic form, which is an indispensable feature of any evolving system, relies on these same resources, but because the internal and external conditions of development are not reconstituted identically in succeeding generations, these conditions-and the phenotypes to which they give rise-will always be characterized by at least some variability.


Assuntos
Evolução Biológica , Determinismo Genético , Fenótipo , Genótipo
17.
J Am Chem Soc ; 134(23): 9796-804, 2012 Jun 13.
Artigo em Inglês | MEDLINE | ID: mdl-22642269

RESUMO

Heat shock protein 90 (Hsp90) represents a promising therapeutic target for the treatment of cancer and other diseases. Unfortunately, results from clinical trials have been disappointing as off-target effects and toxicities have been observed. These detriments may be a consequence of pan-Hsp90 inhibition, as all clinically evaluated Hsp90 inhibitors simultaneously disrupt all four human Hsp90 isoforms. Using a structure-based approach, we designed an inhibitor of Grp94, the ER-resident Hsp90. The effect manifested by compound 2 on several Grp94 and Hsp90α/ß (cytosolic isoforms) clients were investigated. Compound 2 prevented intracellular trafficking of the Toll receptor, inhibited the secretion of IGF-II, affected the conformation of Grp94, and suppressed Drosophila larval growth, all Grp94-dependent processes. In contrast, compound 2 had no effect on cell viability or cytosolic Hsp90α/ß client proteins at similar concentrations. The design, synthesis, and evaluation of 2 are described herein.


Assuntos
Desenho de Fármacos , Proteínas de Choque Térmico HSP70/antagonistas & inibidores , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/metabolismo , Animais , Linhagem Celular , Drosophila/efeitos dos fármacos , Drosophila/crescimento & desenvolvimento , Células HEK293 , Proteínas de Choque Térmico HSP70/química , Proteínas de Choque Térmico HSP90/antagonistas & inibidores , Proteínas de Choque Térmico HSP90/metabolismo , Humanos , Fator de Crescimento Insulin-Like II/metabolismo , Proteínas de Membrana/química , Modelos Moleculares , Conformação Proteica/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Receptores Toll-Like/metabolismo
18.
Antimicrob Agents Chemother ; 56(8): 4184-8, 2012 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-22615279

RESUMO

A major limitation in the identification of novel antichlamydial compounds is the paucity of effective methods for large-scale compound screening. The immunofluorescence assay is the preferred approach for accurate quantification of the intracellular growth of Chlamydia. In this study, an immunofluorescence image-based method (termed image-based automated chlamydial identification and enumeration [iBAChIE]) was customized for fully automated quantification of Chlamydia infection using the freely available open-source image analysis software program CellProfiler and the complementary data exploration software program CellProfiler Analyst. The method yielded enumeration of different species and strains of Chlamydia highly comparably to the conventional manual methods while drastically reducing the analysis time. The inhibitory capability of established antichlamydial activity was also evaluated. Overall, these data support that iBAChIE is a highly effective tool for automated quantification of Chlamydia infection and assessment of antichlamydial activities of molecules. Furthermore, iBAChIE is expected to be amenable to high-throughput screening studies for inhibitory compounds and fluorescently labeled molecules to study host-pathogen interactions.


Assuntos
Antibacterianos/farmacologia , Infecções por Chlamydia/tratamento farmacológico , Infecções por Chlamydia/microbiologia , Chlamydia/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Imunofluorescência , Interações Hospedeiro-Patógeno , Humanos , Processamento de Imagem Assistida por Computador , Camundongos , Testes de Sensibilidade Microbiana
19.
Chem Res Toxicol ; 25(9): 1955-63, 2012 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-22867114

RESUMO

The hepatotoxicity of thioacetamide (TA) has been known since 1948. In rats, single doses cause centrolobular necrosis accompanied by increases in plasma transaminases and bilirubin. To elicit these effects, TA requires oxidative bioactivation, leading first to its S-oxide (TASO) and then to its chemically reactive S,S-dioxide (TASO(2)), which ultimately modifies amine-lipids and proteins. To generate a suite of liver proteins adducted by TA metabolites for proteomic analysis and to reduce the need for both animals and labeled compounds, we treated isolated hepatocytes directly with TA. Surprisingly, TA was not toxic at concentrations up to 50 mM for 40 h. On the other hand, TASO was highly toxic to isolated hepatocytes as indicated by LDH release, cellular morphology, and vital staining with Hoechst 33342/propidium iodide. TASO toxicity was partially blocked by the CYP2E1 inhibitors diallyl sulfide and 4-methylpyrazole and was strongly inhibited by TA. Significantly, we found that hepatocytes produce TA from TASO relatively efficiently by back-reduction. The covalent binding of [(14)C]-TASO is inhibited by unlabeled TA, which acts as a "cold-trap" for [(14)C]-TA and prevents its reoxidation to [(14)C]-TASO. This in turn increases the net consumption of [(14)C]-TASO despite the fact that its oxidation to TASO(2) is inhibited. The potent inhibition of TASO oxidation by TA, coupled with the back-reduction of TASO and its futile redox cycling with TA, may help explain phenomena previously interpreted as "saturation toxicokinetics" in the in vivo metabolism and toxicity of TA and TASO. The improved understanding of the metabolism and covalent binding of TA and TASO facilitates the use of hepatocytes to prepare protein adducts for target protein identification.


Assuntos
Hepatócitos/metabolismo , Tioacetamida/análogos & derivados , Tioacetamida/metabolismo , Animais , Células Cultivadas , Citocromo P-450 CYP2E1/metabolismo , Inibidores do Citocromo P-450 CYP2E1 , Hepatócitos/efeitos dos fármacos , L-Lactato Desidrogenase/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Tioacetamida/toxicidade
20.
Am Psychol ; 77(6): 784-785, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-36074571

RESUMO

Disciplines like evolutionary developmental psychology admirably focus on trying to rehabilitate narrow evolutionary psychology (NEP) from within, by adding a developmental focus to NEP's tenets of adaptationism and computationalism. We argue, however, that these tenets are fundamentally incompatible with taking psychology and its development seriously, and that the kinds of modifications introduced by evolutionary developmental psychologists do not go deep enough to qualitatively change the nondevelopmental outlook of NEP. (PsycInfo Database Record (c) 2022 APA, all rights reserved).


Assuntos
Evolução Biológica , Psicologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA