107 research outputs found
The revitalised Fonofale as a research paradigm: A perspective on Pacific sexuality and reproduction research
Research into Pacific peoples’ sexuality and reproduction is often complex and conflicts with social tapu. Historically, Pacific sexuality and reproduction research had been approached using a deficits-based lens with minimal congruence of Pacific cultural values. We offer a revitalised Fonofale model (Pulotu-Endemann, 1995) as a research paradigm that centres tapu in all considerations and decisions surrounding the research. This revitalised model offers a strengths-based approach that can promote valuable collection of, and meaningful engagement with data. We offer a case study which utilised this research paradigm as an overarching strategy. Te Tīpani Project was a mixed methods investigation into eighty-two Pacific tertiary students’ understandings of sexuality and reproduction. Pacific research methods and methodologies, including the Kakala model and Talanoa method supported the integration of the paradigm into components of the study. We encourage researchers to utilise this strategy to fulfil their research obligations, as facilitators and guardians (mana tiaki) of the research environment. Pacific research methods, methodologies and epistemologies hold an important place in the field of sensitive Pacific well-being research by enabling cultural consideration and responsiveness
A fresh look at the evolution and diversification of photochemical reaction centers
In this review, I reexamine the origin and diversification of photochemical reaction centers based on the known phylogenetic relations of the core subunits, and with the aid of sequence and structural alignments. I show, for example, that the protein folds at the C-terminus of the D1 and D2 subunits of Photosystem II, which are essential for the coordination of the water-oxidizing complex, were already in place in the most ancestral Type II reaction center subunit. I then evaluate the evolution of reaction centers in the context of the rise and expansion of the different groups of bacteria based on recent large-scale phylogenetic analyses. I find that the Heliobacteriaceae family of Firmicutes appears to be the earliest branching of the known groups of phototrophic bacteria; however, the origin of photochemical reaction centers and chlorophyll synthesis cannot be placed in this group. Moreover, it becomes evident that the Acidobacteria and the Proteobacteria shared a more recent common phototrophic ancestor, and this is also likely for the Chloroflexi and the Cyanobacteria. Finally, I argue that the discrepancies among the phylogenies of the reaction center proteins, chlorophyll synthesis enzymes, and the species tree of bacteria are best explained if both types of photochemical reaction centers evolved before the diversification of the known phyla of phototrophic bacteria. The primordial phototrophic ancestor must have had both Type I and Type II reaction centers
Male partner attendance of skilled antenatal care in peri-urban Gulu district, Northern Uganda
<p>Abstract</p> <p>Background</p> <p>Male partner attendance of skilled Antenatal Care (ANC) is beneficial to improving maternal outcomes. This study investigated the level, perceived benefits and factors associated with male partner attendance of skilled ANC in a peri-urban community recovering from two decades of civil conflict.</p> <p>Methods</p> <p>This cross-sectional survey used multi-stage sampling in 12 villages of Omoro county to select 331 married male respondents aged 18 years or more, whose female spouses had childbirth within 24 months prior to the survey. A structured questionnaire elicited responses about male partner attendance of ANC during pregnancy at a public health facility as the main outcome variable. Analysis used Generalized Linear Model (GLM) in Stata version 10.0 to obtain Prevalence Risk Ratios (PRR) for association between the binary outcome and independent factors. All factors significant at p < 0.15 and potential confounders were included in the multivariable model.</p> <p>Results</p> <p>Overall, 65.4% (95%CI; 60.3, 70.5) male partners attended at least one skilled ANC visit. Mean age was 31.9 years [SD 8.2]. Perceived benefits of attending ANC were: HIV screening (74.5%), monitoring foetal growth (34%) and identifying complications during pregnancy (18.9%). Factors independently associated with higher ANC attendance were: knowledge of 3 or more ANC services (adj.PRR 2.77; 95%CI 2.24, 3.42), obtaining health information from facility health workers (adj.PRR 1.14; 95%CI 1.01, 1.29) and if spouse had skilled attendance at last childbirth (adj.PRR 1.31; 95%CI 1.04-1.64). However, factors for low attendance were: male partners intending their spouse to carry another pregnancy (adj.PRR 0.83; 95%CI 0.71, 0.97) and living more than 5 Km from a health facility (adj.PRR 0.83, 95%CI 0.70, 0.98).</p> <p>Conclusions</p> <p>Men who were knowledgeable of ANC services, obtained health information from a health worker and whose spouses utilised skilled delivery at last pregnancy were more likely to accompany their spouses at ANC, unlike those who wanted to have more children and lived more than 5 km from the health facility. These findings suggest that empowering male partners with knowledge about ANC services may increase their ANC participation and in turn increase skilled delivery. This strategy may improve maternal health care in post conflict and resource-limited settings.</p
Visualizing the 3D Architecture of Multiple Erythrocytes Infected with Plasmodium at Nanoscale by Focused Ion Beam-Scanning Electron Microscopy
Different methods for three-dimensional visualization of biological structures have been developed and extensively applied by different research groups. In the field of electron microscopy, a new technique that has emerged is the use of a focused ion beam and scanning electron microscopy for 3D reconstruction at nanoscale resolution. The higher extent of volume that can be reconstructed with this instrument represent one of the main benefits of this technique, which can provide statistically relevant 3D morphometrical data. As the life cycle of Plasmodium species is a process that involves several structurally complex developmental stages that are responsible for a series of modifications in the erythrocyte surface and cytoplasm, a high number of features within the parasites and the host cells has to be sampled for the correct interpretation of their 3D organization. Here, we used FIB-SEM to visualize the 3D architecture of multiple erythrocytes infected with Plasmodium chabaudi and analyzed their morphometrical parameters in a 3D space. We analyzed and quantified alterations on the host cells, such as the variety of shapes and sizes of their membrane profiles and parasite internal structures such as a polymorphic organization of hemoglobin-filled tubules. The results show the complex 3D organization of Plasmodium and infected erythrocyte, and demonstrate the contribution of FIB-SEM for the obtainment of statistical data for an accurate interpretation of complex biological structures
Earth: Atmospheric Evolution of a Habitable Planet
Our present-day atmosphere is often used as an analog for potentially
habitable exoplanets, but Earth's atmosphere has changed dramatically
throughout its 4.5 billion year history. For example, molecular oxygen is
abundant in the atmosphere today but was absent on the early Earth. Meanwhile,
the physical and chemical evolution of Earth's atmosphere has also resulted in
major swings in surface temperature, at times resulting in extreme glaciation
or warm greenhouse climates. Despite this dynamic and occasionally dramatic
history, the Earth has been persistently habitable--and, in fact,
inhabited--for roughly 4 billion years. Understanding Earth's momentous changes
and its enduring habitability is essential as a guide to the diversity of
habitable planetary environments that may exist beyond our solar system and for
ultimately recognizing spectroscopic fingerprints of life elsewhere in the
Universe. Here, we review long-term trends in the composition of Earth's
atmosphere as it relates to both planetary habitability and inhabitation. We
focus on gases that may serve as habitability markers (CO2, N2) or
biosignatures (CH4, O2), especially as related to the redox evolution of the
atmosphere and the coupled evolution of Earth's climate system. We emphasize
that in the search for Earth-like planets we must be mindful that the example
provided by the modern atmosphere merely represents a single snapshot of
Earth's long-term evolution. In exploring the many former states of our own
planet, we emphasize Earth's atmospheric evolution during the Archean,
Proterozoic, and Phanerozoic eons, but we conclude with a brief discussion of
potential atmospheric trajectories into the distant future, many millions to
billions of years from now. All of these 'Alternative Earth' scenarios provide
insight to the potential diversity of Earth-like, habitable, and inhabited
worlds.Comment: 34 pages, 4 figures, 4 tables. Review chapter to appear in Handbook
of Exoplanet
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