Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
PeerJ ; 8: e8400, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32002331

RESUMO

An isolated hyomandibula from a lower Toarcian carbonate concretion of the Ahrensburg erratics assemblage (Schleswig-Holstein, northern Germany) represents the first record of a chondrosteid fish from the Lower Jurassic of the southwestern Baltic realm. Except for its smaller size, the specimen is morphologically indistinguishable from corresponding elements of Gyrosteus mirabilis from the Toarcian of Yorkshire, England. This find, which probably originates from the western Baltic basin between Bornholm Island (Denmark) and northeastern Germany, markedly expands the known range of this chondrosteid taxon across the northern part of the strait connecting the Boreal Sea with the Tethys Ocean during the Early Jurassic. For the first time the extension of the paleogeographic range of a chondrosteid species beyond its type area is documented, which can contribute to future studies of vertebrate faunal provincialism during the Lower Jurassic in Europe.

2.
PeerJ ; 4: e2813, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-28028478

RESUMO

The holotype of Brancasaurus brancai is one of the most historically famous and anatomically complete Early Cretaceous plesiosaurian fossils. It derived from the Gerdemann & Co. brickworks clay pit near Gronau (Westfalen) in North Rhine-Westphalia, northwestern Germany. Stratigraphically this locality formed part of the classic European "Wealden facies," but is now more formally attributed to the upper-most strata of the Bückeberg Group (upper Berriasian). Since its initial description in 1914, the type skeleton of B. brancai has suffered damage both during, and after WWII. Sadly, these mishaps have resulted in the loss of substantial information, in particular many structures of the cranium and limb girdles, which are today only evidenced from published text and/or illustrations. This non-confirmable data has, however, proven crucial for determining the relationships of B. brancai within Plesiosauria: either as an early long-necked elasmosaurid, or a member of the controversial Early Cretaceous leptocleidid radiation. To evaluate these competing hypotheses and compile an updated osteological compendium, we undertook a comprehensive examination of the holotype as it is now preserved, and also assessed other Bückeberg Group plesiosaurian fossils to establish a morphological hypodigm. Phylogenetic simulations using the most species-rich datasets of Early Cretaceous plesiosaurians incorporating revised scores for B. brancai, together with a second recently named Bückeberg Group plesiosaurian Gronausaurus wegneri (Hampe, 2013), demonstrated that referral of these taxa to Leptocleididae was not unanimous, and that the topological stability of this clade is tenuous. In addition, the trait combinations manifested by B. brancai and G. wegneri were virtually identical. We therefore conclude that these monotypic individuals are ontogenetic morphs and G. wegneri is a junior synonym of B. brancai. Finally, anomalies detected in the diagnostic features for other "Wealden" plesiosaurians have prompted reconsiderations of interspecies homology versus intraspecific variability. We therefore propose that the still unresolved taxonomy of B. brancai should emphasize only those character states evident in the examinable fossil material, and specifically accommodate for growth-related modifications delimited via osteologically mature referred specimens.

3.
Zootaxa ; 4154(2): 197-200, 2016 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-27615836

RESUMO

Two genus-group names of flat-worms-Leptocleidus Mueller, 1936 and Macrorhynchus von Graff, 1882-are junior homonyms that are preoccupied by fossil diapsid reptile genera-Leptocleidus Andrews, 1922, and Macrorhynchus Dunker, 1843-and an extant teleost fish genus-Macrorhynchus [Gmelin, 1801] ex La Cépède, 1800. These are replaced by nomina nova (Pharyngodytes nom. nov.; Graffiellus nom. nov.). Macrorhynchus [Gmelin, 1801] is an objective senior synonym of Macrorhyncus Dumeríl, 1805 ex La Cépède, 1800 (syn. nov.), and a senior homonym of Macrorhynchus Dunker, 1843, and Macrorhynchus von Graff, 1882.


Assuntos
Platelmintos/classificação , Animais , Fósseis/história , História do Século XIX , História do Século XX , Terminologia como Assunto
4.
Eur J Paediatr Neurol ; 20(1): 147-51, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26387070

RESUMO

OBJECTIVE: Mutations in the CDKL5 gene cause an early-onset epileptic encephalopathy. To date, little is known about effective antiepileptic treatment in this disorder. METHOD: Accordingly, the aim of this retrospective study was to explore the role of different antiepileptic drugs (AEDs) and the ketogenic diet (KD) in the treatment of this rare genetic disorder. We evaluated the efficacy in 39 patients with CDKL5 mutations at 3, 6 and 12 months after the introduction of each treatment. One patient was lost to follow-up after 6 and 12 months. RESULTS: The responder rate (>50% reduction in seizure frequency) to at least one AED or KD was 69% (27/39) after 3 months, 45% (17/38) after 6 months and 24% (9/38) after 12 months. The highest rate of seizure reduction after 3 months was reported for FBM (3/3), VGB (8/25), CLB (4/17), VPA (7/34), steroids (5/26), LTG (5/23) and ZNS (2/11). Twelve patients (31%) experienced a seizure aggravation to at least one AED. Most patients showed some but only initial response to various AEDs with different modes of actions. SIGNIFICANCE: Considering both age-related and spontaneous fluctuation in seizure frequency and the unknown impact of many AEDs or KD on cognition, our data may help defining realistic treatment goals and avoiding overtreatment in patients with CDKL5 mutations. There is a strong need to develop new treatment strategies for patients with this rare mutation.


Assuntos
Anticonvulsivantes/uso terapêutico , Dieta Cetogênica , Epilepsia/dietoterapia , Epilepsia/tratamento farmacológico , Adulto , Epilepsia/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Mutação , Proteínas Serina-Treonina Quinases/genética , Estudos Retrospectivos , Convulsões/prevenção & controle , Resultado do Tratamento , Adulto Jovem
5.
PLoS One ; 8(4): e60571, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23560099

RESUMO

A fragmentary cervico-pectoral lateral spine and partial humerus of an ankylosaur from the Early Cretaceous (early Valanginian) of Gronau in Westfalen, northwestern Germany, are described. The spine shows closest morphological similarities to the characteristic cervical and pectoral spines of Hylaeosaurus armatus from the late Valanginian of England. An extensive comparison of distal humeri among thyreophoran dinosaurs supports systematic differences in the morphology of the distal condyli between Ankylosauria and Stegosauria and a referral of the Gronau specimen to the former. The humerus fragment indicates a rather small individual, probably in the size range of H. armatus, and both specimens are determined herein as ?Hylaeosaurus sp.. A short overview of other purported ankylosaur material from the Berriasian-Valanginian of northwest Germany shows that, aside from the material described herein, only tracks can be attributed to this clade with confidence at present.


Assuntos
Dinossauros/anatomia & histologia , Fósseis , Úmero/anatomia & histologia , Paleontologia , Coluna Vertebral/anatomia & histologia , Animais , Dinossauros/classificação , Alemanha , Filogeografia
6.
Opt Express ; 21(25): 31098-104, 2013 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-24514684

RESUMO

We present a diode incorporating a large number (12) of GaAs quantum wells that emits light from exciton-polariton states at room temperature. A reversely biased tunnel junction is placed in the cavity region to improve current injection into the device. Electroluminescence studies reveal two polariton branches which are spectrally separated by a Rabi splitting of 6.5 meV. We observe an anticrossing of the two branches when the temperature is lowered below room temperature as well as a Stark shift of both branches in a bias dependent photoluminescence measurement.


Assuntos
Arsenicais/química , Gálio/química , Iluminação/instrumentação , Pontos Quânticos , Semicondutores , Desenho de Equipamento , Análise de Falha de Equipamento , Integração de Sistemas , Temperatura
8.
Eur Arch Otorhinolaryngol ; 269(7): 1755-8, 2012 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22045302

RESUMO

Since inner ear hair cells are mechano-electric transducers the control of hydrostatic pressure in the inner ear is crucial. Most studies analyzing dynamics and regulation of inner ear hydrostatic pressure performed pressure measurements in the cochlea. The present study is the first one reporting about absolute hydrostatic pressure values in the labyrinth. Hydrostatic pressure of the endolymphatic system was recorded in all three semicircular canals. Mean pressure values were 4.06 cmH(2)O ± 0.61 in the posterior, 3.36 cmH(2)O ± 0.94 in the anterior and 3.85 cmH(2)O ± 1.38 in the lateral semicircular canal. Overall hydrostatic pressure in the vestibular organ was 3.76 cmH(2)O ± 0.36. Endolymphatic hydrostatic pressure in all three semicircular canals is the same (p = 0.310). With regard to known endolymphatic pressure values in the cochlea from past studies vestibular pressure values are comparable to cochlear values. Until now it is not known whether the reuniens duct and the Bast's valve which are the narrowest passages in the endolymphatic system are open or closed. Present data show that most likely the endolymphatic system is a functionally open entity.


Assuntos
Deslocamentos de Líquidos Corporais/fisiologia , Pressão Hidrostática , Líquidos Labirínticos/fisiologia , Vestíbulo do Labirinto/fisiologia , Animais , Cóclea/fisiologia , Cobaias , Hidrodinâmica , Valores de Referência , Canais Semicirculares/fisiologia
9.
PLoS One ; 6(10): e25693, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-22022431

RESUMO

BACKGROUND: Archosaurs (birds, crocodilians and their extinct relatives including dinosaurs) dominated Mesozoic continental ecosystems from the Late Triassic onwards, and still form a major component of modern ecosystems (>10,000 species). The earliest diverse archosaur faunal assemblages are known from the Middle Triassic (c. 244 Ma), implying that the archosaur radiation began in the Early Triassic (252.3-247.2 Ma). Understanding of this radiation is currently limited by the poor early fossil record of the group in terms of skeletal remains. METHODOLOGY/PRINCIPAL FINDINGS: We redescribe the anatomy and stratigraphic position of the type specimen of Ctenosauriscus koeneni (Huene), a sail-backed reptile from the Early Triassic (late Olenekian) Solling Formation of northern Germany that potentially represents the oldest known archosaur. We critically discuss previous biomechanical work on the 'sail' of Ctenosauriscus, which is formed by a series of elongated neural spines. In addition, we describe Ctenosauriscus-like postcranial material from the earliest Middle Triassic (early Anisian) Röt Formation of Waldhaus, southwestern Germany. Finally, we review the spatial and temporal distribution of the earliest archosaur fossils and their implications for understanding the dynamics of the archosaur radiation. CONCLUSIONS/SIGNIFICANCE: Comprehensive numerical phylogenetic analyses demonstrate that both Ctenosauriscus and the Waldhaus taxon are members of a monophyletic grouping of poposauroid archosaurs, Ctenosauriscidae, characterised by greatly elongated neural spines in the posterior cervical to anterior caudal vertebrae. The earliest archosaurs, including Ctenosauriscus, appear in the body fossil record just prior to the Olenekian/Anisian boundary (c. 248 Ma), less than 5 million years after the Permian-Triassic mass extinction. These earliest archosaur assemblages are dominated by ctenosauriscids, which were broadly distributed across northern Pangea and which appear to have been the first global radiation of archosaurs.


Assuntos
Evolução Biológica , Dinossauros/anatomia & histologia , Filogeografia , Animais , Dinossauros/genética , Fósseis , Alemanha , Paleontologia , Filogenia , Fatores de Tempo
10.
Genes Immun ; 5(5): 435-8, 2004 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-15175649

RESUMO

Chlamydia pneumoniae uses peripheral blood monocytes (PBMC) for systemic dissemination and has been linked to atherogenesis by inflammation mediated via TLR2/4 and CD14. We found 12.8% of 610 coronary artery disease (CAD) patients of Central European background to be chronically infected with C. pneumoniae based on the repeated detection of chlamydial DNA in PBMC. Among those the -159C>T CD14 promoter polymorphism was more frequent (OR 1.7, 95% CI 1.08-2.65, P=0.0224) than among C. pneumoniae-negative subjects matched for age and gender. The Arg753Gln TLR2 and Asp299Gly TLR4 polymorphisms were not related to chlamydial infection. Susceptibility for chronic chlamydial infection of PBMC in CAD patients appears associated with the CD14-159C>T promoter polymorphism encoding for enhanced CD14 expression.


Assuntos
Infecções por Chlamydia/genética , Chlamydophila pneumoniae , Receptores de Lipopolissacarídeos/genética , Monócitos/microbiologia , Polimorfismo Genético , Regiões Promotoras Genéticas/genética , Anticorpos Antibacterianos/biossíntese , Anticorpos Antibacterianos/genética , Infecções por Chlamydia/metabolismo , Infecções por Chlamydia/microbiologia , Frequência do Gene/genética , Predisposição Genética para Doença/genética , Humanos , Monócitos/metabolismo
12.
Avian Dis ; 46(2): 485-92, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12061663

RESUMO

In this paper we report on an outbreak of reovirus, herpesvirus (Pacheco disease), and/or mycosis infection (Aspergillus spp. and Zygomyces spp.) affecting a batch of young African grey parrots (Psittacus erithacus), with 80% morbidity and 30% mortality. Study material was taken from five birds (four dead and one euthanatized) with a range of clinical symptoms (depression, diarrhea, respiratory symptoms). Diagnosis was confirmed by immunohistochemical detection of avian reovirus, electron microscopy, and virus isolation. Viral antigen of reovirus was detected mainly in large mononuclear cells in the bursa of Fabricius and the spleen, pancreas epithelial cells, and circulating cells; lymphoid organs displayed the largest number of immunopositive cells and severe lymphocyte depletion. Bacteriologic study was negative. Reovirus infection was common in all birds studied, whereas Pacheco disease and mycosis were found in only some, suggesting that reovirus could be the initial cause triggering the outbreak and facilitating infection by other agents and their swift spread through the batch.


Assuntos
Doenças das Aves/virologia , Surtos de Doenças/veterinária , Papagaios , Infecções por Reoviridae/veterinária , Reoviridae/isolamento & purificação , Animais , Antígenos Virais/análise , Doenças das Aves/epidemiologia , Doenças das Aves/mortalidade , Doenças das Aves/patologia , Guiné/epidemiologia , Infecções por Herpesviridae/complicações , Infecções por Herpesviridae/patologia , Infecções por Herpesviridae/veterinária , Imuno-Histoquímica/veterinária , Microscopia Eletrônica/veterinária , Micoses/complicações , Micoses/patologia , Micoses/veterinária , Reoviridae/imunologia , Reoviridae/ultraestrutura , Infecções por Reoviridae/complicações , Infecções por Reoviridae/epidemiologia , Infecções por Reoviridae/patologia
13.
Nature ; 415(6875): 1000-3, 2002 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-11875561

RESUMO

Jupiter's X-ray aurora has been thought to be excited by energetic sulphur and oxygen ions precipitating from the inner magnetosphere into the planet's polar regions. Here we report high-spatial-resolution observations that demonstrate that most of Jupiter's northern auroral X-rays come from a 'hot spot' located significantly poleward of the latitudes connected to the inner magnetosphere. The hot spot seems to be fixed in magnetic latitude and longitude and occurs in a region where anomalous infrared and ultraviolet emissions have also been observed. We infer from the data that the particles that excite the aurora originate in the outer magnetosphere. The hot spot X-rays pulsate with an approximately 45-min period, a period similar to that reported for high-latitude radio and energetic electron bursts observed by near-Jupiter spacecraft. These results invalidate the idea that jovian auroral X-ray emissions are mainly excited by steady precipitation of energetic heavy ions from the inner magnetosphere. Instead, the X-rays seem to result from currently unexplained processes in the outer magnetosphere that produce highly localized and highly variable emissions over an extremely wide range of wavelengths.

14.
Circulation ; 103(3): 351-6, 2001 Jan 23.
Artigo em Inglês | MEDLINE | ID: mdl-11157684

RESUMO

BACKGROUND: Recovery of the intracellular bacterium Chlamydia pneumoniae from atherosclerotic plaques has initiated large studies on antimicrobial therapy in coronary artery disease. The basic concept that antibiotic therapy may eliminate and prevent vascular infection was evaluated in vitro and in vivo by examining the antibiotic susceptibility of C pneumoniae in circulating human monocytes, which are thought to transport chlamydiae from the respiratory tract to the vascular wall. METHODS AND RESULTS: Blood monocytes (CD14+) from 2 healthy volunteers were obtained before and after oral treatment with azithromycin or rifampin and then inoculated with a vascular C pneumoniae strain and continuously cultured in the presence of the respective antibiotic. Progress of infection and chlamydial viability was assessed by immunogold-labeling and detection of C pneumoniae-specific mRNA transcripts. Circulating monocytes from patients undergoing treatment with experimental azithromycin for coronary artery disease were examined for C pneumoniae infection by cell culture. Antibiotics did not inhibit chlamydial growth within monocytes. Electron microscopy showed development of chlamydial inclusion bodies. Reverse transcription-polymerase chain reaction demonstrated continuous synthesis of chlamydial mRNA for 10 days without lysis of the monocytes. The in vivo presence of viable pathogen not eliminated by azithromycin was shown by cultural recovery of C pneumoniae from the circulating monocytes of 2 patients with coronary artery disease. CONCLUSIONS: C pneumoniae uses monocytes as a transport system for systemic dissemination and enters a persistent state not covered by an otherwise effective antichlamydial treatment. Prevention of vascular infection by antichlamydial treatment may be problematic: circulating monocytes carrying a pathogen with reduced antimicrobial susceptibility might initiate reinfection or promote atherosclerosis by the release of proinflammatory mediators.


Assuntos
Antibacterianos/farmacologia , Azitromicina/farmacologia , Chlamydophila pneumoniae/efeitos dos fármacos , Doença das Coronárias/tratamento farmacológico , Monócitos/microbiologia , Rifampina/farmacologia , Idoso , Antibacterianos/uso terapêutico , Azitromicina/uso terapêutico , Células Cultivadas , Chlamydophila pneumoniae/genética , Chlamydophila pneumoniae/patogenicidade , Chlamydophila pneumoniae/ultraestrutura , Doença das Coronárias/sangue , Doença das Coronárias/microbiologia , Humanos , Receptores de Lipopolissacarídeos/imunologia , Masculino , Testes de Sensibilidade Microbiana , Microscopia Imunoeletrônica , Pessoa de Meia-Idade , Monócitos/efeitos dos fármacos , Monócitos/imunologia , RNA Mensageiro/análise , RNA Mensageiro/biossíntese , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Rifampina/uso terapêutico , Fatores de Tempo
15.
Wien Med Wochenschr ; 151(24): 594-9, 2001.
Artigo em Alemão | MEDLINE | ID: mdl-11820176

RESUMO

It is well accepted that coronary artery disease is linked to an inflammatory process. It is unproven however whether either infectious agents may cause or accelerate coronary artery disease or the inflammatory process is due to metabolic or toxic effects. Among the possible infectious agents Chlamydia pneumoniae is the most likely bacterium involved in atherosclerosis. The arguments in favour of Chlamydia pneumoniae originate from seroepidemiologic studies and from detection and isolation of bacteria from vascular lesions. This review summarises the present understanding of the role of bacterial infection for development or progression of coronary artery disease.


Assuntos
Infecções por Chlamydia/diagnóstico , Chlamydophila pneumoniae/patogenicidade , Doença da Artéria Coronariana/diagnóstico , Animais , Infecções por Chlamydia/microbiologia , Doença da Artéria Coronariana/microbiologia , Humanos , Virulência
16.
J Infect Dis ; 181 Suppl 3: S449-51, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10839736

RESUMO

Because individual diagnoses of vascular infection with Chlamydia pneumoniae depend entirely on surgically removed tissues, a better assay to predict vascular infection is needed. Polymerase chain reaction detection of chlamydial DNA was applied to CD14-positive cells collected from 238 patients with angiographically identified unstable angina or acute myocardial infarction. C. pneumoniae was detected in 52 (28%) of 188 persons with unstable angina and in 13 (26%) of 50 persons with myocardial infarction. Differences between groups were not significant. C. pneumoniae is present in monocytes/macrophages of a significant proportion of persons with progressive coronary artery disease. Infarction is not accompanied by a rise in chlamydial detection rates. The potential role of chlamydiae in coronary atherosclerosis may therefore be more related to acceleration of disease or systemic effects by persistent infection than to sudden initiation of infarction by acute infection.


Assuntos
Angina Instável/microbiologia , Infecções por Chlamydia/microbiologia , Chlamydophila pneumoniae/isolamento & purificação , Monócitos/microbiologia , Infarto do Miocárdio/microbiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Chlamydophila pneumoniae/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Reação em Cadeia da Polimerase/métodos
17.
Basic Res Cardiol ; 95 Suppl 1: I59-64, 2000.
Artigo em Inglês | MEDLINE | ID: mdl-11192355

RESUMO

It is well accepted that coronary artery disease is linked to an inflammatory process. It is unknown which agents may cause or accelerate coronary artery disease. An inflammation of the vessel wall may be caused by a number of mechanisms such as accumulation of glycosylated proteins in diabetic patients, oxidised LDL in patients with hypercholesterolemia or infectious agents. Among the possible infectious agents Chlamydia pneumoniae is the most likely microorganism involved in atherosclerosis. The arguments in favour of Chlamydia pneumoniae result from seroepidemiologic studies and from detection of chlamydial DNA in atherosclerotic plaques by polymerase chain reaction (PCR). In addition this microorganism is the only one that could be isolated from atherosclerotic tissue. This review summarises the present understanding of the role of an inflammatory process in the development or progression of coronary artery disease.


Assuntos
Doença das Coronárias/etiologia , Doença das Coronárias/microbiologia , Infecções/complicações , Vasculite/complicações , Proteínas de Fase Aguda/metabolismo , Animais , Infecções Bacterianas , Doença das Coronárias/fisiopatologia , Doença das Coronárias/terapia , Progressão da Doença , Humanos , Vasculite/microbiologia , Viroses
18.
Zentralbl Veterinarmed B ; 46(6): 375-80, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10481620

RESUMO

This paper concerns a disease affecting a group of African grey parrots, which involves intranuclear inclusion bodies composed of filamentous material. The disease was characterized by either sudden death or death within 2-3 days from onset of non-specific symptoms. At necropsy, gross lesions included enlarged liver, mild hepatic congestion and focal necrosis. Samples from five birds were fixed in 10% formol and routinely processed for light and electron microscopy. In four birds, numerous hepatocytes displayed an enlarged nucleus, with peripheral margination of chromatin; the nucleus was partially or wholly filled by a basophilic inclusion body. In the remaining bird, inclusion bodies were acidophilic and completely filled the nucleus; nuclear enlargement was less evident than in the other birds. At ultrastructural examination, and in both types of IIB, nuclei contained looped filaments but no evidence of viral structures. However, virion-like structures were observed in the cytoplasm of some hepatocytes.


Assuntos
Doenças das Aves/virologia , Hepatite Animal/virologia , Corpos de Inclusão/ultraestrutura , Papagaios , Animais , Doenças das Aves/epidemiologia , Doenças das Aves/patologia , Surtos de Doenças/veterinária , Infecções por Escherichia coli/patologia , Infecções por Escherichia coli/veterinária , Hepatite Animal/epidemiologia , Hepatite Animal/patologia , Rim/patologia , Rim/ultraestrutura , Fígado/patologia , Fígado/ultraestrutura , Microscopia Eletrônica/veterinária , Infecções por Pasteurella/patologia , Infecções por Pasteurella/veterinária , Vírion/ultraestrutura
20.
J Neural Transm Suppl ; 44: 97-109, 1994.
Artigo em Inglês | MEDLINE | ID: mdl-7897403

RESUMO

Examples are given for assessing parameters for motor activity learning and memory. By using the method of the open field the authors could verify that motor activity decreases with age and that it underlies obviously endogenous rhythms which undergo age dependent alterations (e.g. diminution of the amplitude). From the results of an investigation on the influence of ageing and stress on learning ability and memory of the rat the authors draw the following conclusions: Learning ability declines with advancing age. The effect of ageing on memory could not be clearly shown. The effect of the stressors used (crowding and noise) seems to depend on the season of the year (circannual biorhythm).


Assuntos
Envelhecimento/psicologia , Aprendizagem , Memória , Atividade Motora , Animais , Ritmo Circadiano , Escuridão , Luz , Masculino , Aprendizagem em Labirinto , Probabilidade , Psicometria , Ratos , Ratos Sprague-Dawley , Valores de Referência , Reforço Psicológico
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...