48 research outputs found

    Chemical Constituents and Evaluation of Antimicrobial and Cytotoxic Activities of Kielmeyera coriacea

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    Many essential oils (EOs) of different plant species possess interesting antimicrobial effects on buccal microorganisms and cytotoxic properties. EOs of Kielmeyera coriacea Mart. & Zucc. were analyzed by gas chromatography coupled to mass spectrometry (GC-MS). The EO from leaves is rich in sesquiterpenes hydrocarbons and oxygenated sesquiterpenes. The three major compounds identified were germacrene-D (24.2%), (E)-caryophyllene (15.5%), and bicyclogermacrene (11.6%). The inner bark EO is composed mainly of sesquiterpenes hydrocarbons and the major components are alpha-copaene (14.9%) and alpha-(E)-bergamotene (13.0%). The outer bark EO is composed mainly of oxygenated sesquiterpenes and long-chain alkanes, and the major components are alpha-eudesmol (4.2%) and nonacosane (5.8%). The wood EO is mainly composed of long-chain alkanes and fatty acids, and the major components are nonacosane (9.7%) and palmitic acid (16.2%). The inner bark EO showed the strongest antimicrobial activity against the anaerobic bacteria Prevotella nigrescens (minimum inhibitory concentration-MIC of 50 µg mL−1). The outer bark and wood EOs showed MICs of 100 µg mL−1 for all aerobic microorganisms tested. The EOs presented low toxicity to Vero cells. These results suggest that K. coriacea, a Brazilian plant, provide initial evidence of a new and alternative source of substances with medicinal interest

    Secular trends and social inequalities in child behavioural problems across three Brazilian cohort studies (1993, 2004 and 2015)

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    Abstract Aims Previous epidemiological evidence identified a concerning increase in behavioural problems among young children from 1997 to 2008 in Brazil. However, it is unclear whether behavioural problems have continued to increase, if secular changes vary between sociodemographic groups and what might explain changes over time. We aimed to monitor changes in child behavioural problems over a 22-year period from 1997 to 2019, examine changing social inequalities and explore potential explanations for recent changes in behavioural problems between 2008 and 2019. Methods The Child Behaviour Checklist was used to compare parent-reported behavioural problems in 4-year-old children across three Brazilian birth cohorts assessed in 1997 (1993 cohort, n = 633), 2008 (2004 cohort, n = 3750) and 2019 (2015 cohort, n = 577). Response rates across all three population-based cohorts were over 90%. Moderation analyses tested if cross-cohort changes differed by social inequalities (demographic and socioeconomic position), while explanatory models explored whether changes in hypothesized risk and protective factors in prenatal development (e.g., smoking during pregnancy) and family life (e.g., maternal depression and harsh parenting) accounted for changes in child behavioural problems from 2008 to 2019. Results Initial increases in child behavioural problems from 1997 to 2008 were followed by declines in conduct problems (mean change = −2.75; 95% confidence interval [CI]: −3.56, −1.94; P < 0.001), aggression (mean change = −1.84; 95% CI: −2.51, −1.17; P < 0.001) and rule-breaking behaviour (mean change = −0.91; 95% CI: −1.13, −0.69 P < 0.001) from 2008 to 2019. Sex differences in rule-breaking behaviour diminished during this 22-year period, whereas socioeconomic inequalities in behavioural problems emerged in 2008 and then remained relatively stable. Consequently, children from poorer and less educated families had higher behavioural problems, compared to more socially advantaged children, in the two more recent cohorts. Changes in measured risk and protective factors partly explained the reduction in behavioural problems from 2008 to 2019. Conclusions Following a rise in child behavioural problems, there was a subsequent reduction in behavioural problems from 2008 to 2019. However, social inequalities increased and remained high. Continued monitoring of behavioural problems by subgroups is critical for closing the gap between socially advantaged and disadvantaged children and achieving health equity for the next generation

    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016
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