504 research outputs found
The effect of green biobased binder on structural, mechanical, liquid absorption and wetting properties of coated papers
Synthetic styrene-butadiene (SB) and styrene-acrylic (SA) latex binders used in paper coating formulations are common and based on unsustainable petroleum sources. Today\u27s papermaking industry turns towards sustainable substitutes that do not compromise quality, and reduce carbon emission, toxic substance release and waste disposal concerns related to fossil fuel sources. In this study, colloidal starch-based latex nanoparticles that do not require cooking were used for pigment coating and coated on the paper surfaces. The effects of these new biobased binders on the structural and mechanical strength properties, liquid absorption, wetting and surface topography of the paper were investigated and compared with the properties of coated paper that SB latex was used as a coating binder. The results demonstrated that the biobased latex decreases the grammage of paper while maintaining an identical thickness relative to the SB latex samples. The porosity, permeability and roughness of biobased latex are found higher than the SB latex. The biobased latex successfully replaced SB latex at 1:1 ratio and enabled an equivalent of bursting, tear, tensile strength and structural properties
The Case for a Sociology of Dying, Death and Bereavement
YesDying, death and bereavement do not occur in a social vacuum. How individuals and groups experience these phenomena will be largely influenced by the social context in which they occur. To develop an adequate understanding of dying, death and bereavement we therefore need to incorporate a sociological perspective into our analysis. This paper examines why a sociological perspective is necessary and explores various ways in which sociology can be of practical value in both intellectual and professional contexts. A case study comparing psychological and sociological perspectives is offered by way of illustration
Bereavement and the role of religious and cultural factors.
yesThe aim of this article is to give an overview of some of the key dimensions of variation in cultural and religious rituals during the immediate period after a death and in the longer term, in order to inform service delivery in multi-cultural societies. For each area we give examples of different customs, and consider their functions and possible impact. Dimensions considered in the immediate period after bereavement are: The time and space given to formal rituals, expression of feelings, assertion of status and disposal of the body. In the longer term, we look at variations in remembering the deceased and in continuing bonds. Throughout we consider the interplay between individual responses and the personÂżs cultural and religious context. Our objective is to provide an accessible introduction for practitioners new to working with bereavement and provide a succinct reference point for more experienced bereavement workers.Full text made available 1st May 2014 at the end of the publisher's embargo period
Thermoelectric Response of an Interacting Two-Dimensional Electron Gas in Quantizing Magnetic Field
We present a discussion of the linear thermoelectric response of an
interacting electron gas in a quantizing magnetic field. Boundary currents can
carry a significant fraction of the net current passing through the system. We
derive general expressions for the bulk and boundary components of the number
and energy currents. We show that the local current density may be described in
terms of ``transport'' and ``internal magnetization'' contributions. The latter
carry no net current and are not observable in standard transport experiments.
We show that although Onsager relations cannot be applied to the local current,
they are valid for the transport currents and hence for the currents observed
in standard transport experiments. We relate three of the four thermoelectric
response coefficients of a disorder-free interacting two-dimensional electron
gas to equilibrium thermodynamic quantities. In particular, we show that the
diffusion thermopower is proportional to the entropy per particle, and we
compare this result with recent experimental observations.Comment: 18 pages, 2 postscript figures included. Revtex with epsf.tex and
multicol.sty. In the revised version, the comparison with experimental
observations at is extended to include the possibility of
corrections due to weak impurity scattering. The conclusions that we reach
regarding the applicability of the composite fermion model at these filling
fractions are not affecte
Bereavement and palliative care: A public health perspective
In recent years there has been an increasing emphasis upon public health perspectives that place palliative care in the context of end-of-life services across whole populations. There is little corresponding public health interest in bereavement. Yet if we have to develop relevant, coherent, and comprehensive end-of-life care policies and practices, public health approaches to palliative care need to be accompanied by public health approaches to bereavement care. We argue here that palliative care services should match their commitment to providing a good death with a commitment to supporting good grief, and that this means investing their efforts principally in developing community capacity for bereavement care rather than seeking to deliver specialized bereavement services to relatives and friends of those who have received palliative care services
Hormonal Signal Amplification Mediates Environmental Conditions during Development and Controls an Irreversible Commitment to Adulthood
Many animals can choose between different developmental fates to maximize fitness. Despite the complexity of environmental cues and life history, different developmental fates are executed in a robust fashion. The nematode Caenorhabditis elegans serves as a powerful model to examine this phenomenon because it can adopt one of two developmental fates (adulthood or diapause) depending on environmental conditions. The steroid hormone dafachronic acid (DA) directs development to adulthood by regulating the transcriptional activity of the nuclear hormone receptor DAF-12. The known role of DA suggests that it may be the molecular mediator of environmental condition effects on the developmental fate decision, although the mechanism is yet unknown. We used a combination of physiological and molecular biology techniques to demonstrate that commitment to reproductive adult development occurs when DA levels, produced in the neuroendocrine XXX cells, exceed a threshold. Furthermore, imaging and cell ablation experiments demonstrate that the XXX cells act as a source of DA, which, upon commitment to adult development, is amplified and propagated in the epidermis in a DAF-12 dependent manner. This positive feedback loop increases DA levels and drives adult programs in the gonad and epidermis, thus conferring the irreversibility of the decision. We show that the positive feedback loop canalizes development by ensuring that sufficient amounts of DA are dispersed throughout the body and serves as a robust fate-locking mechanism to enforce an organism-wide binary decision, despite noisy and complex environmental cues. These mechanisms are not only relevant to C. elegans but may be extended to other hormonal-based decision-making mechanisms in insects and mammals
A Small Conductance Calcium-Activated K<sup>+</sup> Channel in C. elegans, KCNL-2, Plays a Role in the Regulation of the Rate of Egg-Laying
In the nervous system of mice, small conductance calcium-activated potassium (SK) channels function to regulate neuronal excitability through the generation of a component of the medium afterhyperpolarization that follows action potentials. In humans, irregular action potential firing frequency underlies diseases such as ataxia, epilepsy, schizophrenia and Parkinson's disease. Due to the complexity of studying protein function in the mammalian nervous system, we sought to characterize an SK channel homologue, KCNL-2, in C. elegans, a genetically tractable system in which the lineage of individual neurons was mapped from their early developmental stages. Sequence analysis of the KCNL-2 protein reveals that the six transmembrane domains, the potassium-selective pore and the calmodulin binding domain are highly conserved with the mammalian homologues. We used widefield and confocal fluorescent imaging to show that a fusion construct of KCNL-2 with GFP in transgenic lines is expressed in the nervous system of C. elegans. We also show that a KCNL-2 null strain, kcnl-2(tm1885), demonstrates a mild egg-laying defective phenotype, a phenotype that is rescued in a KCNL-2-dependent manner. Conversely, we show that transgenic lines that overexpress KCNL-2 demonstrate a hyperactive egg-laying phenotype. In this study, we show that the vulva of transgenic hermaphrodites is highly innervated by neuronal processes and by the VC4 and VC5 neurons that express GFP-tagged KCNL-2. We propose that KCNL-2 functions in the nervous system of C. elegans to regulate the rate of egg-laying. © 2013 Chotoo et al
A transcriptomic snapshot of early molecular communication between Pasteuria penetrans and Meloidogyne incognita
© The Author(s). 2018Background: Southern root-knot nematode Meloidogyne incognita (Kofoid and White, 1919), Chitwood, 1949 is a key pest of agricultural crops. Pasteuria penetrans is a hyperparasitic bacterium capable of suppressing the nematode reproduction, and represents a typical coevolved pathogen-hyperparasite system. Attachment of Pasteuria endospores to the cuticle of second-stage nematode juveniles is the first and pivotal step in the bacterial infection. RNA-Seq was used to understand the early transcriptional response of the root-knot nematode at 8 h post Pasteuria endospore attachment. Results: A total of 52,485 transcripts were assembled from the high quality (HQ) reads, out of which 582 transcripts were found differentially expressed in the Pasteuria endospore encumbered J2 s, of which 229 were up-regulated and 353 were down-regulated. Pasteuria infection caused a suppression of the protein synthesis machinery of the nematode. Several of the differentially expressed transcripts were putatively involved in nematode innate immunity, signaling, stress responses, endospore attachment process and post-attachment behavioral modification of the juveniles. The expression profiles of fifteen selected transcripts were validated to be true by the qRT PCR. RNAi based silencing of transcripts coding for fructose bisphosphate aldolase and glucosyl transferase caused a reduction in endospore attachment as compared to the controls, whereas, silencing of aspartic protease and ubiquitin coding transcripts resulted in higher incidence of endospore attachment on the nematode cuticle. Conclusions: Here we provide evidence of an early transcriptional response by the nematode upon infection by Pasteuria prior to root invasion. We found that adhesion of Pasteuria endospores to the cuticle induced a down-regulated protein response in the nematode. In addition, we show that fructose bisphosphate aldolase, glucosyl transferase, aspartic protease and ubiquitin coding transcripts are involved in modulating the endospore attachment on the nematode cuticle. Our results add new and significant information to the existing knowledge on early molecular interaction between M. incognita and P. penetrans.Peer reviewedFinal Published versio
Beyond the Womb and the Tomb: Identity, (Dis)embodiment and the Life Course
Grounded in the authors’ theoretical and ethnographic work on pregnancy and social life after death, this article explores the ways in which the body is involved in processes of identification. With a focus on the embodied nature of social identity, the article nonetheless problematizes a model of the life course that begins at the moments of birth and ends at death. Instead, it offers a more extended temporal perspective and examines other ways in which identity may be claimed, for example, via material objects and practices which evoke the body as imagined or remembered. By documenting pre-birth and post-mortem identity-making of this kind, it demonstrates how the unborn and the dead may come into social existence. In addition, a cultural privileging of both the body and visuality is shown to shore up the capacity of material objects and practices to shape social identities in a highly selective fashion. The article therefore proposes that models of the life course need to accommodate the meanings of pre-birth and post-mortem materialities and so incorporate a conceptualization of social identity as contested, relational and inevitably incomplete
- …