Ab initio molecular dynamics of the reactivity of vitamin C toward hydroxyl and $$ {HO}_2/{O}_2^{-} $$ radicals

Vitamin C is one of the most abundant exogenous antioxidants in the cell, and it is of the utmost importance to elucidate its mechanism of action against radicals. In this study, the reactivity of vitamin C toward OH and \( {HO}_2/{O}_2^{-} \) radicals in aqueous medium was analyzed by ab initio molecular dynamics using CPMD code. The simulations led to results similar to those of static studies or experiments for the pair of \( {HO}_2/{O}_2^{-} \) radicals but bring new insights for the reactivity with hydroxyl radical: the reaction takes place before the formation of an adduct and consists of two steps: first an electron is transferred to hydroxyl radical and then the ascorbyl radical loses a proton.

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Graphical Abstract Reactivity of vitamin C toward hydroxyl and \( {HO}_2/{O}_2^{-} \) radicals

     

History of Pregnancy Loss Increases the Risk of Mental Health Problems in Subsequent Pregnancies but Not in the Postpartum

While grief, emotional distress and other mental health conditions have been associated with pregnancy loss, less is known about the mental health impact of these events during subsequent pregnancies and births. This paper examined the impact of any type of pregnancy loss on mental health in a subsequent pregnancy and postpartum. Data were obtained from a sub-sample (N = 584) of the 1973-78 cohort of the Australian Longitudinal Study on Women''s Health, a prospective cohort study that has been collecting data since 1996. Pregnancy loss was defined as miscarriage, termination due to medical reasons, ectopic pregnancy and stillbirth. Mental health outcomes included depression, anxiety, stress or distress, sadness or low mood, excessive worry, lack of enjoyment, and feelings of guilt. Demographic factors and mental health history were controlled for in the analysis. Women with a previous pregnancy loss were more likely to experience sadness or low mood (AOR = 1.75, 95% CI: 1.11 to 2.76, p = 0.0162), and excessive worry (AOR = 2.01, 95% CI: 1.24 to 3.24, p = 0.0043) during a subsequent pregnancy, but not during the postpartum phase following a subsequent birth. These results indicate that while women who have experienced a pregnancy loss are a more vulnerable population during a subsequent pregnancy, these deficits are not evident in the postpartum.     

Conformational analysis of macrocyclic frankincense (<Emphasis Type="Italic">Boswellia</Emphasis>) diterpenoids

Frankincense oleoresin has been used in traditional medicine for more than 5000 years. The phytochemistry of frankincense (Boswellia spp.) resins includes triterpenoids (including boswellic acids and their derivatives), diterpenoids (cembrenoids and cneorubenoids), and essential oils. The macrocyclic cembrene diterpenoids may play a part in the biological activities of frankincense resin, but neither the biological targets nor the modes of interaction with the targets are currently known. How these macrocycles interact with biological macromolecules likely depends on what conformation(s) are energetically available to them. In this work, a conformational analysis of 15 Boswellia cembrene diterpenoids and 1 verticillane diterpenoid was carried out at the B3LYP/6-31G* and M06-2X/6-31G* levels of theory, including the SM8 aqueous solvation model. The lowest-energy conformations of boscartin B and incensole oxide were the same as the previously reported X-ray crystal structures, while the lowest-energy conformations of boscartins A and C were very similar to the crystal structures. Boscartins D-H and isoincensole oxide showed only one low-energy conformation for each compound and are predicted to be conformationally locked. Incensole, isoincensolol, and serratol are predicted to be conformationally mobile with several low-energy forms. The conformational mobility of Boswellia cembrenoid diterpenoids depends largely on the degree of epoxidation, either oxirane or tetrahydrofuran rings.     

Evidence of multiple introductions and genetic admixture of the Asian brush-clawed shore crab <Emphasis Type="Italic">Hemigrapsus takanoi</Emphasis> (Decapoda: Brachyura: Varunidae) along the Northern European coast

The Asian brush-clawed shore crab Hemigrapsus takanoi is a non-indigenous species along the Northern European coast. Although the history of range expansion of European H. takanoi has been well-documented, little is known about the genetic compositions of either the introduced European populations or the native Asian ones. We therefore collected H. takanoi broadly from their native Asian sites and introduced European ranges, and genotyped them by sequencing the mitochondrial 16S RNA gene and by analyzing nuclear microsatellite loci. Our results revealed that the H. takanoi Bay of Seine (France) populations consisted of a genetic admixture between populations in Japan and those in the Yellow Sea region. These French populations should be carefully monitored in the future, since the genetic admixture of multiple source populations may accelerate range expansion in non-indigenous organisms. Our results also suggested that shipping lines from East Asia were more probable vectors than historical juvenile oyster transportations from Japan for the foundation of present European H. takanoi populations. Interestingly, gene flow between populations in Japan and those in the Yellow Sea region (i.e., domestic invasion) was not observed despite the higher potential for artificial translocations via shipping lines in the native Asian range compared with those from Asia to Europe. The lack of domestic invasions implied that intra-specific priority effects of the resident H. takanoi populations played an important role in preventing the successful colonization of artificially-transferred individuals.     

Maternal Health Factors as Risks for Postnatal Depression: A Prospective Longitudinal Study

Purpose

While previous studies have identified a range of potential risk factors for postnatal depression (PND), none have examined a comprehensive set of risk factors at a population-level using data collected prospectively. The aim of this study was to explore the relationship between a range of factors and PND and to construct a model of the predictors of PND.

Methods

Data came from 5219 women who completed Survey 5 of the Australian Longitudinal Study on Women’s Health in 2009 and reported giving birth to a child.

Results

Over 15% of women reported experiencing PND with at least one of their children. The strongest positive associations were for postnatal anxiety (OR = 13.79,95%CI = 10.48,18.13) and antenatal depression (OR = 9.23,95%CI = 6.10,13.97). Positive associations were also found for history of depression and PND, low SF-36 Mental Health Index, emotional distress during labour, and breastfeeding for less than six months.

Conclusions

Results indicate that understanding a woman’s mental health history plays an important role in the detection of those who are most vulnerable to PND. Treatment and management of depression and anxiety earlier in life and during pregnancy may have a positive impact on the incidence of PND.     

Quality,Rigour and Usefulness of Free-Text Comments Collected by a Large Population Based Longitudinal Study - ALSWH

While it is common practice for health surveys to include an open-ended question asking for additional comments, the responses to these questions are often not analysed or used by researchers as data. The current project employed an automated semantic program to assess the useability and thematic content of the responses to an open-ended free response item included in the Australian Longitudinal Study on Women’s Health (ALSWH) surveys. The study examined the comments of three cohorts of women, born between 1973–78, 1946–51, and 1921–26, from Survey 1 (in 1996) and Survey 5 (in 2007–2009). Findings revealed important differences in the health status of responders compared to non-responders. Across all three cohorts, and at both time points, women who commented tended to have poorer physical health (except for women aged 82–87) and social functioning, experienced more life events, were less likely to be partnered, and (except for women aged 18–23 years) more likely to have higher levels of education, than women who did not comment. Results for mental health were mixed. The analysis revealed differences between cohorts as well as changes over time. The most common themes to emerge for the 1973–78 cohort were health, time, pregnant and work, for the 1946–51 cohort, the most common themes were health, life, time and work, while for the 1921–26 cohort, the most common themes were husband, health and family. The concepts and frequency of concepts changed from the first to the fifth survey. For women in the 1973–78 cohort, pregnant emerged as a prevalent theme, while eating disappeared. Among women in the 1946–51 cohort, cancer, operation and medication emerged as prevalent themes, while for women in the 1921–26 cohort, the concept children disappeared, while family emerged. This analysis suggests that free-text comments are a valuable data source, suitable for content, thematic and narrative analysis, particularly when collected over time.     

Assessing the diversity of New Zealand freshwater harpacticoid copepods (Crustacea: Copepoda) using mitochondrial DNA (COI) barcodes

Taxonomic and ecological studies of freshwater harpacticoid copepods are limited globally by the ability to easily and accurately identify specimens. Here, we test the use of the mitochondrial cytochrome c oxidase subunit I (COI) gene locus as a tool for assessing the diversity of freshwater Harpacticoida. We obtained sequences from New Zealand harpacticoid copepods, representing two families, five genera and nine species, including the non-indigenous Elaphoidella sewelli. All species were delineated by the COI gene. However, high intraspecific diversity was evident among populations of Elaphoidella bidens (>12%), and between North and South Island populations of Bryocamptus pygmaeus (>18%), potentially indicating the presence of morphologically cryptic taxa. We suggest that mitochondrial DNA (COI) sequences can provide a useful tool for the routine identification of freshwater harpacticoid copepods. Applications of these data will include assessing species diversity and biogeography as well as assisting with the detection of non-indigenous species.     

The effect of nitrogen limitation on acetyl-CoA carboxylase expression and fatty acid content in Chromera velia and Isochrysis aff. galbana (TISO)

Lipids from microalgae have become a valuable product with applications ranging from biofuels to human nutrition. While changes in fatty acid (FA) content and composition under nitrogen limitation are well documented, the involved molecular mechanisms are poorly understood. Acetyl-CoA carboxylase (ACCase) is a key enzyme in the FA synthesis and elongation pathway. Plastidial and cytosolic ACCases provide malonyl-CoA for de novo FA synthesis in the plastid and FA elongation in the endoplasmic reticulum, respectively. The present study aimed at investigating the expression of plastidial and cytosolic ACCase in Chromera velia and Isochrysis aff. galbana (TISO) and their impact on FA content and elongation level when grown under nitrogen-deplete conditions. In C. velia, plastidial ACCase was significantly upregulated during nitrogen starvation and with culture age, strongly correlating with increased FA content. Conversely, plastidial ACCase of I. aff. galbana was not differentially expressed in nitrogen-deplete cultures, but upregulated during the logarithmic phase of nitrogen-replete cultures. In contrast to plastidial ACCase, the cytosolic ACCase of C. velia was downregulated with culture age and nitrogen-starvation, strongly correlating with an increase in medium-chain FAs. In conclusion, the expression of plastidial and cytosolic ACCase changed with growth phase and nutrient status in a species-specific manner and nitrogen limitation did not always result in FA accumulation.