Gender equity and fertility intentions in Italy and the Netherlands

Fertility levels have fallen drastically in most industrialized countries. Diverse theoretical and empirical frameworks have had difficulty in explaining these unprecedented low levels of fertility. More recently, however, attention has turned from classic explanations, such as women’s increased labour market participation, to gender equity as the essential link to understand this phenomenon. The increase in women’s labour market participation did not prompt an increase in men’s domestic duties, which is often referred to women’s ‘dual burden’ or ‘second shift’. Institutions and policies within countries also facilitate or constrain the combination of women’s employment with fertility. This paper provides an empirical test of gender equity theory by examining whether the unequal division of household labour leads to lower fertility intentions of women in different institutional contexts. Italy constitutes a case of high gender inequity, low female labour market participation and the lowest-low fertility. The Netherlands has moderate to low gender inequity, high part-time female labour market participation and comparatively higher fertility. Using data from the 2003 Italian Multipurpose Survey - Family and Social Actors and the 2004/5 Dutch sample from the European Social Survey, a series of logistic regression models test this theory. A central finding is that the unequal division of household labour only has a significant impact on women’s fertility intentions when they already carry the load of high paid work hours or children, a finding that is particularly significant for working women in Italy.fertility, fertility intentions, gender, paid and unpaid work

Development of a Method of Analysis by High Performance Liquid Chromatography for Products of the Nitric Acid Oxidation of D-Glucose

This thesis explored the development of a faster and more efficient means of qualitative and quantitative analysis of the products of the nitric acid oxidation of D-glucose and other simple sugars, for the Shafizadeh Rocky Mountain Center for Wood and Carbohydrate Chemistry. During the research, analysis was carried out based on previous work completed in a similar area using two Aminex HPX-87H+ cation-exchange columns at different temperatures, and plumbed in series. Standards were filtered and injected on to the columns, then eluted with 5 mM sulfuric acid. A total run time of 33 minutes enabled the elution of all products and by-products of the reaction. Retention times of standards and the use of spiking helped specify and quantify unknowns in samples from a series of oxidation reactions involving D-glucose and other aldoses. The PrevailTM Organic acid (OA) column was said to provide 'unsurpassed resolution of organic acids'. It was therefore investigated, and a method was developed and refined in order to optimise conditions enabling the column's use for the required analyses. The optimised parameters were established as: ambient temperature with an eluent of 10 mM KH2PO4 adjusted to a pH of 2.1 with phosphoric acid. The sample size was 5 uL with a flow rate of 0.3 mL/min, giving a total run time of approximately 13 minutes. The Aminex HPX-87H+ column method and the PrevailTM OA method were compared to determine the superior method for the analyses intended. While some improvements were made for detection in the PrevailTM OA method, results were not satisfactory. This was due in part to limits imposed on the PrevailTM OA column method, which prevented the use of gradient elution. The Aminex HPX-87H+ column method outlined herein provides superior resolution for the nitric acid oxidation of D-glucose to D-glucaric acid, and in conclusion it is suggested that the Aminex HPX-87H+ column method be used

Bifidobacterial Dominance of the Gut in Early Life and Acquisition of Antimicrobial Resistance.

Bifidobacterium species are important commensals capable of dominating the infant gut microbiome, in part by producing acids that suppress growth of other taxa. Bifidobacterium species are less prone to possessing antimicrobial resistance (AMR) genes (ARGs) than other taxa that may colonize infants. Given that AMR is a growing public health crisis and ARGs are present in the gut microbiome of humans from early life, this study examines the correlation between a Bifidobacterium-dominated infant gut microbiome and AMR levels, measured by a culture-independent metagenomic approach both in early life and as infants become toddlers. In general, Bifidobacterium dominance is associated with a significant reduction in AMR in a Bangladeshi cohort, both in the number of acquired AMR genes present and in the abundance of AMR genes. However, by year 2, Bangladeshi infants had no significant differences in AMR related to their early-life Bifidobacterium levels. A generalized linear model including all infants in a previously published Swedish cohort found a significant negative association between log-transformed total AMR and Bifidobacterium levels, thus confirming the relationship between Bifidobacterium levels and AMR. In both cohorts, there was no change between early-life and later-life AMR abundance in high-Bifidobacterium infants but a significant reduction in AMR abundance in low-Bifidobacterium infants. These results support the hypothesis that early Bifidobacterium dominance of the infant gut microbiome may help reduce colonization by taxa containing ARGs.IMPORTANCE Infants are vulnerable to an array of infectious diseases, and as the gut microbiome may serve as a reservoir of AMR for pathogens, reducing the levels of AMR in infants is important to infant health. This study demonstrates that high levels of Bifidobacterium are associated with reduced levels of AMR in early life and suggests that probiotic interventions to increase infant Bifidobacterium levels have the potential to reduce AMR in infants. However, this effect is not sustained at year 2 of age in Bangladeshi infants, underscoring the need for more detailed studies of the biogeography and timing of infant AMR acquisition

The fecal resistome of dairy cattle is associated with diet during nursing.

Antimicrobial resistance is a global public health concern, and livestock play a significant role in selecting for resistance and maintaining such reservoirs. Here we study the succession of dairy cattle resistome during early life using metagenomic sequencing, as well as the relationship between resistome, gut microbiota, and diet. In our dataset, the gut of dairy calves serves as a reservoir of 329 antimicrobial resistance genes (ARGs) presumably conferring resistance to 17 classes of antibiotics, and the abundance of ARGs declines gradually during nursing. ARGs appear to co-occur with antibacterial biocide or metal resistance genes. Colostrum is a potential source of ARGs observed in calves at day 2. The dynamic changes in the resistome are likely a result of gut microbiota assembly, which is closely associated with diet transition in dairy calves. Modifications in the resistome may be possible via early-life dietary interventions to reduce overall antimicrobial resistance

Effects of Exogenous Yeast and Bacteria on the Microbial Population Dynamics and Outcomes of Olive Fermentations.

In this study, we examined Sicilian-style green olive fermentations upon the addition of Saccharomyces cerevisiae UCDFST 09-448 and/or Pichia kudriazevii UCDFST09-427 or the lactic acid bacteria (LAB) Lactobacillus plantarum AJ11R and Leuconostoc pseudomesenteroides BGM3R. Olives containing S. cerevisiae UCDFST 09-448, a strain able to hydrolyze pectin, but not P. kudriazevii UCDFST 09-427, a nonpectinolytic strain, exhibited excessive tissue damage within 4 weeks. DNA sequencing of fungal internal transcribed spacer (ITS) regions and comparisons to a yeast-specific ITS sequence database remarkably showed that neither S. cerevisiae UCDFST 09-448 nor P. kudriazevii UCDFST 09-427 resulted in significant changes to yeast species diversity. Instead, Candida boidinii constituted the majority (>90%) of the total yeast present, independent of whether S. cerevisiae or P. kudriazevii was added. By comparison, Lactobacillus species were enriched in olives inoculated with potential starter LAB L. plantarum AJ11R and L. pseudomesenteroides BGM3R according to community 16S rRNA gene sequence analysis. The bacterial diversity of those olives was significantly reduced and resembled control fermentations incubated for a longer period of time. Importantly, microbial populations were highly dynamic at the strain level, as indicated by the large variations in AJ11R and BGM3R cell numbers over time and reductions in the numbers of yeast isolates expressing polygalacturonase activity. These findings show the distinct effects of exogenous spoilage and starter microbes on indigenous communities in plant-based food fermentations that result in very different impacts on product quality. IMPORTANCE Food fermentations are subject to tremendous selective pressures resulting in the growth and persistence of a limited number of bacterial and fungal taxa. Although these foods are vulnerable to spoilage by unintended contamination of certain microorganisms, or alternatively, can be improved by the deliberate addition of starter culture microbes that accelerate or beneficially modify product outcomes, the impact of either of those microbial additions on community dynamics within the fermentations is not well understood at strain-specific or global scales. Herein, we show how exogenous spoilage yeast or starter lactic acid bacteria confer very different effects on microbial numbers and diversity in olive fermentations. Introduced microbes have long-lasting consequences and result in changes that are apparent even when levels of those inoculants and their major enzymatic activities decline. This work has direct implications for understanding bacterial and fungal invasions of microbial habitats resulting in pivotal changes to community structure and function

Potentials of Mean Force as a Starting Point for Understanding Biomolecular Interactions.

Computer simulations on the molecular dynamics of biological molecules can be used to explore the behavior of large molecules with a level of detail not possible in experiments. It is necessary to be cautious, however, when designing and interpreting such simulations, as the techniques commonly used to improve efficiency of simulations can lead to unrealistic results. The work presented in this dissertation explores ways in which the accuracy of molecular dynamics simulations can be both improved and validated by experimental data, primarily through the use of potentials of mean force (PMFs). Experimental input was used in the development of an umbrella sampling protocol by fitting restraining potentials to an experimental PMF. The method was tested on a model peptide using a ”guiding” PMF from simulations and then validated using an experimental PMF from force manipulation studies on a mechanical protein. The results show that the experimentally guided umbrella sampling replicates the appropriate pathways for both systems, whereas naively chosen potentials fail to do so. Experimental findings were also used in the design of steered molecular dynamics simulations on the β domain of streptokinase. High-temperature simulations were used to smooth the energy surface and enable the system to explore alternate unfolding pathways. The results show three distinct pathways, in agreement with experimental evidence of three types of behavior under force. The simulations reveal that the source of the differences are hydrophobic interaction in the core of the protein. Multi-dimensional PMFs were calculated to describe these pathways energetically. All-atom simulations were also used to study a different type of system, the interactions between DNA and a Polyamidoamine dendrimer. Both the dendrimer and DNA were found to deform substantially upon binding. While the interactions were shown to be driven primarily by electrostatics, we also find that ordered waters extend the interaction distance beyond the range of direct electrostatics for one orientation of the dendrimer. These water effects contribute almost a third of the total interaction free energy of the system. PMFs calculated in these simulations were used to calculate force extension curves which agree with experiments on DNA condensed by dendrimers.Ph.D.BiophysicsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/75883/1/pisaster_1.pd