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1.
Science ; 190(4212): 382-3, 1975 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-1179215

RESUMO

Sexual reproduction predominates among organisms mainly because most evolutionary change is concentrated in speciation events, and asexual species cannot speciate in the normal sense. Asexual clones seldom diversify rapidly enough to overcome normal rates of extinction. In contrast, phylogenetic groups of sexual species (clades) commonly develop broad, heterogeneous adaptive zones rapidly enough to ensure survival.


Assuntos
Evolução Biológica , Reprodução , Sexo , Animais , Meio Ambiente , Recombinação Genética , Reprodução Assexuada
2.
Science ; 166(3905): 634-5, 1969 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-17778205

RESUMO

Oblique and chevron-like ridges on the shell surfaces of certain burrowing bivalve mollusks grip the sediment during shell-rocking movements to aid in sediment penetration. These ridges (characterized by steep dorsal slopes and gentle ventral slopes) have evolved through convergence in several families in association with particular behavioral and ecological traits.

3.
Science ; 266(5189): 1340-4, 1994 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-17772839

RESUMO

Three tests based on fossil data indicate that high rates of extinction recorded in the penultimate (Guadalupian) stage of the Paleozoic era are not artifacts of a poor fossil record. Instead, they represent an abrupt mass extinction that was one of the largest to occur in the past half billion years. The final mass extinction of the era, which took place about 5 million years after the Guadalupian event, remains the most severe biotic crisis of all time. Taxonomic losses in the Late Permian were partitioned among the two crises and the intervening interval, however, and the terminal Permian crisis eliminated only about 80 percent of marine species, not 95 or 96 percent as earlier estimates have suggested.

4.
Mil Psychol ; 2(2): 108-114, 2015 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-26236093

RESUMO

Military spouses often have concerns regarding the impact of their communication on soldiers during deployment. However, literature is mixed regarding how communication between soldiers and spouses may impact soldiers' self-reported work functioning during deployment, suggesting the need to evaluate moderating factors. In the current study, three relationship factors (marital satisfaction, conflictual communication, and proportion of conversation focused on problems) were tested as moderators of communication frequency and negative marriage-to-work spillover for soldiers. Whereas the three relationship factors were independently related to negative spillover, none significantly moderated the relationship between communication frequency and spillover. The overall pattern of results suggests that (a) lower marital satisfaction, a focus on problems during communication, and conflictual communication are each strongly linked to spillover for deployed soldiers, and (b) military couples may be self-restricting deployment communication frequency when experiencing less marital satisfaction and higher rates of negative communication. Implications for communication during deployment are discussed.

5.
J Mass Spectrom ; 35(3): 402-7, 2000 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-10767770

RESUMO

The metabolism and urinary excretion of a 100 mg dose of the non-sedating anxiolytic drug buspirone was examined using high-performance liquid chromatography/electrospray ionization mass spectrometry in the positive ion mode. In addition to a significant proportion of unchanged buspirone we were able to detect three major metabolite classes. These were identified as monohydroxy, dihydroxy and dihydroxymethoxy products. Detection of the metabolites and the parent drug was possible in all the urine samples collected (1-12 h) post-administration.


Assuntos
Ansiolíticos/metabolismo , Buspirona/metabolismo , Cavalos/metabolismo , Espectrometria de Massas/métodos , Animais , Ansiolíticos/química , Ansiolíticos/urina , Buspirona/química , Buspirona/urina , Cromatografia Líquida de Alta Pressão/métodos , Cavalos/urina , Hidroxilação
6.
Science ; 192(4236): 267-9, 1976 Apr 16.
Artigo em Inglês | MEDLINE | ID: mdl-17831162
7.
J Consult Clin Psychol ; 61(1): 70-7, 1993 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-8450110

RESUMO

This article reports the 4- and 5-year follow-up results of evaluating the effects of a marital distress prevention program. The program, Prevention and Relationship Enhancement Program (PREP), is a 5-session program designed to teach couples effective communication and conflict management skills. At the 5-year follow-up, intervention, as compared with control, couples had higher levels of positive and lower levels of negative communication skills and lower levels of marital violence. Data are also presented on couples who declined the program. Issues are discussed concerning selection effects, change mechanisms, and future directions for prevention research.


Assuntos
Comunicação , Conflito Psicológico , Terapia Conjugal/métodos , Casamento/psicologia , Adolescente , Adulto , Feminino , Seguimentos , Humanos , Masculino , Avaliação de Processos e Resultados em Cuidados de Saúde , Resolução de Problemas
8.
Artigo em Inglês | MEDLINE | ID: mdl-12554133

RESUMO

Mass spectrometric analyses of the recombinant proteins in Eprex and Aranesp were undertaken with the goal of producing reference mass spectra and evaluating strategies to improve its applicability as a method for equine and canine doping control of these substances. A simple, low chemical noise deglycosylation reaction removed microheterogeneity due to post-translational carbohydrate attachment and both proteins were detectable using MALDI-TOF-MS. Deglycosylated human erythropoietin (hEPO) was also detected using HPLC-ESI-MS. This is the first time that spectra of deglycosylated Eprex and Aranesp have been published. Eight synthetic reference standards, which match peptides produced by endoproteinase Glu-C enzymatic cleavage of Aranesp and/or Eprex, were analysed by ESI-MS and ESI-MS-MS. The E12 Glu-C peptide, common to both proteins, was detected at the low femtomole-level using gradient nano-HPLC-ESI-MS-MS in the positive ion mode.


Assuntos
Eritropoetina/análogos & derivados , Eritropoetina/análise , Ácidos Cafeicos/análise , Carboidratos , Cromatografia Líquida de Alta Pressão , Darbepoetina alfa , Dissulfetos/análise , Dopagem Esportivo , Glicosilação , Humanos , Hidrólise , Indicadores e Reagentes , Nanotecnologia , Proteínas Recombinantes , Padrões de Referência , Espectrometria de Massas por Ionização por Electrospray , Espectrometria de Massas por Ionização e Dessorção a Laser Assistida por Matriz
9.
Carbohydr Res ; 175(1): 77-83, 1988 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-3288342

RESUMO

The structure of the repeating unit of the capsular polysaccharide from Escherichia coli serotype K36 has been established from the results of spectroscopic and chemical analyses of (a) P1, the tetrasaccharide obtained on depolymerisation of the polysaccharide with a bacteriophage-borne endo-galactosidase, (b) P1-alditol, and (c) the original polysaccharide. The repeating unit, which is identical to that reported for Klebsiella K57, has the following structure. (Formula: see text).


Assuntos
Colífagos/enzimologia , Escherichia coli/imunologia , Galactosidases/metabolismo , Polissacarídeos Bacterianos , Configuração de Carboidratos , Sequência de Carboidratos , Escherichia coli/enzimologia , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular
10.
Carbohydr Res ; 200: 449-56, 1990 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-2199039

RESUMO

The primary structure of the acidic capsular polysaccharide of Escherichia coli K57 was elucidated by methylation analysis and 1D- and 2D-n.m.r. spectroscopy. The repeating unit was identified as a linear tetrasaccharide having the structure shown. ----2)-beta-D-Ribf-(1----4)-beta-D-Galp-(1----3)-alpha-D-GlcpNAc-( 1----4)-alpha - D-GalpA-(1----.


Assuntos
Escherichia coli/imunologia , Polissacarídeos Bacterianos , Configuração de Carboidratos , Sequência de Carboidratos , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular
11.
Carbohydr Res ; 205: 361-70, 1990 Sep 19.
Artigo em Inglês | MEDLINE | ID: mdl-2276144

RESUMO

The structure of the capsular polysaccharide from Escherichia coli O8:K87:H19 was investigated by methylation analysis and by one- and two-dimensional 1H- and 13C-n.m.r. spectroscopy. The repeating unit was shown to be a branched pentasaccharide with the structure (formula; see text)


Assuntos
Antígenos de Bactérias/química , Polissacarídeos Bacterianos/química , Sequência de Carboidratos , Escherichia coli/análise , Escherichia coli/imunologia , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Estrutura Molecular , Polissacarídeos Bacterianos/imunologia
12.
Carbohydr Res ; 266(1): 95-102, 1995 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-7697653

RESUMO

Trideuteriomethylated and methylated derivatives of the capsular polysaccharide of Escherichia coli K57 were partially cleaved by Et3SiH, using Me3SiOSO2 Me and Me3SiOSO2CF3 as catalysts, to produce oligosaccharide-anhydroalditols. The structures of the trideuteriomethylated trisaccharide- and tetrasaccharide-anhydroalditols isolated were established by FABMS and NMR spectroscopy. Although conditions for the selective production of the tetrasaccharide-anhydroalditol could not be established, oligosaccharide-anhydroalditols were isolated in sufficiently high yield to make this an attractive approach for the structural elucidation of the repeating units of bacterial polysaccharides.


Assuntos
Escherichia coli/química , Polissacarídeos Bacterianos/química , Sequência de Carboidratos , Espectroscopia de Ressonância Magnética , Dados de Sequência Molecular , Oligossacarídeos/química , Espectrometria de Massas de Bombardeamento Rápido de Átomos
13.
J Am Vet Med Assoc ; 173(9): 1173-4, 1978 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-738940

RESUMO

Four gray fox became anorectic and developed diarrhea. Their condition worsened until death. Diagnosis of Tyzzer's disease was made on the basis of clinical signs, gross and microscopic lesions, and the demonstration of Bacillus piliformis in the liver.


Assuntos
Raposas , Hepatopatias/veterinária , Animais , Infecções Bacterianas/microbiologia , Infecções Bacterianas/veterinária , Fígado/microbiologia , Hepatopatias/microbiologia
14.
Food Chem Toxicol ; 48(8-9): 2517-25, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20600539

RESUMO

The fruit of the coffee plant, Coffea arabica, has high phenolic antioxidant and phytonutrient content and could be a beneficial food ingredient. However, the fruit has historically been discarded for the favored harvesting of the coffee bean alone. CoffeeBerry products are derived from the whole fruit and include a ground whole powder, a water extract, and a more recently developed water-ethanol extract. The safety of CoffeeBerry products was evaluated in three genotoxicity studies, three short-term oral toxicity studies, and a 90-day dietary toxicity study. Bacterial mutagenicity studies and a micronucleus test using murine peripheral cells demonstrated that none of the three products showed mutagenic or genotoxic potential. In the short-term studies, despite palatability issues, female rats showed a tolerance for whole powder and ethanol extract at doses up to 8800 mg/kg bw/day. Male rats also exhibited palatability issues and tolerated lower doses of approximately 4000 mg/kg bw/day ethanol extract via gavage and approximately 2100 mg/kg bw/day whole powder or water extract in the diet. When fed in the diet to Sprague-Dawley rats for 90 days, ethanol extract showed no adverse effects at dietary concentrations of up to 5% (approximately 3446 and 4087 mg/kg bw/day for male and female rats, respectively).


Assuntos
Café/toxicidade , Animais , Dieta , Relação Dose-Resposta a Droga , Etanol , Feminino , Frutas/toxicidade , Masculino , Camundongos , Testes para Micronúcleos , Testes de Mutagenicidade , Mutagênicos/toxicidade , Nível de Efeito Adverso não Observado , Extratos Vegetais/química , Extratos Vegetais/toxicidade , Pós , Ratos , Ratos Sprague-Dawley , Salmonella typhimurium/efeitos dos fármacos , Salmonella typhimurium/genética , Solventes
17.
Analyst ; 131(8): 892-4, 2006 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-17028721

RESUMO

The transduction signals from the immobilisation of a class I heavy chain, HLA-A2, on a layer guided acoustic plate mode device, followed by binding of beta(2)-microglobulin and subsequent selective binding of a target peptide are reported.


Assuntos
Técnicas Biossensoriais/métodos , Antígeno HLA-A2/metabolismo , Estreptavidina/metabolismo , Técnicas Biossensoriais/instrumentação , Humanos , Microscopia Acústica , Dobramento de Proteína , Mapeamento de Interação de Proteínas , Microglobulina beta-2/metabolismo
18.
Proc Natl Acad Sci U S A ; 72(2): 646-50, 1975 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-1054846

RESUMO

Gradual evolutionary change by natural selection operates so slowly within established species that it cannot account for the major features of evolution. Evolutionary change tends to be concentrated within speciation events. The direction of transpecific evolution is determined by the process of species selection, which is analogous to natural selection but acts upon species within higher taxa rather than upon individuals within populations. Species selection operates on variation provided by the largely random process of speciation and favors species that speciate at high rates or survive for long periods and therefore tend to leave many daughter species. Rates of speciation can be estimated for living taxa by means of the equation for exponential increase, and are clearly higher for mammals than for bivalve mollusks.


Assuntos
Evolução Biológica , Modelos Biológicos , Adaptação Biológica , Animais , Genética Populacional , Mamíferos , Moluscos , Seleção Genética
19.
Proc Natl Acad Sci U S A ; 70(5): 1486-9, 1973 May.
Artigo em Inglês | MEDLINE | ID: mdl-16592084

RESUMO

According to modern ecological theory, high diversity at any trophic level of a community is possible only under the influence of cropping. Until herbivores evolved, single-celled algae of the Precambrain were resource-limited, and a small number of species saturated aquatic environments. In the near-absence of vacant niches, life diversified slowly. Because the changes required to produce the first algae-eating heterotrophs were therefore delayed, the entire system was self-limiting. When the "heterotroph barrier" was finally crossed in the late Precambrian, herbivorous and carnivorous protists arose almost simultaneously, for no major biological differences separate the two groups. These events automatically triggered the formation of a series of self-propagating feedback systems of diversification between adjacent trophic levels. Comparable systems arose among multi-cellular groups, which radiated rapidly from the newly diversifying protist taxa. The sudden proliferation of complex food webs formed by taxa invading previously vacant adaptive zones produced an explosive diversification of life over a period of a few tens of millions of years. The rapid appearance of skeletons in various groups, though of special geological importance, was no more dramatic than other aspects of the radiation. The overall rate of diversification was comparable to rates for less-extensive adaptive radiations of the Phanerozoic.

20.
J Chromatogr B Biomed Appl ; 667(1): 95-103, 1995 May 05.
Artigo em Inglês | MEDLINE | ID: mdl-7663690

RESUMO

A normal-phase HPLC method combined with particle-beam mass spectrometry (PB-MS) was developed for the analysis of non-steroidal anti-inflammatory drugs (NSAIDs). The forty one NSAIDs analysed responded in one or more (electron impact, positive and negative chemical ionisation) modes and highly characteristic spectra were produced. A mixed-mode solid-phase extraction (SPE) method for isolating acidic NSAIDs was developed using the Bond Elut Certify II cartridge. The average recovery was 88.5%. Flunixin, extracted by SPE from urine of a mare to which the meglumine salt had been administered was positively identified by HPLC-PB-MS and HPLC-atmospheric pressure ionization (API) MS methods.


Assuntos
Anti-Inflamatórios não Esteroides/urina , Cromatografia Líquida de Alta Pressão/métodos , Clonixina/análogos & derivados , Espectrometria de Massas/métodos , Animais , Clonixina/urina , Feminino , Cavalos , Pressão
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