693 research outputs found
Network Structure Explains the Impact of Attitudes on Voting Decisions
Attitudes can have a profound impact on socially relevant behaviours, such as
voting. However, this effect is not uniform across situations or individuals,
and it is at present difficult to predict whether attitudes will predict
behaviour in any given circumstance. Using a network model, we demonstrate that
(a) more strongly connected attitude networks have a stronger impact on
behaviour, and (b) within any given attitude network, the most central attitude
elements have the strongest impact. We test these hypotheses using data on
voting and attitudes toward presidential candidates in the US presidential
elections from 1980 to 2012. These analyses confirm that the predictive value
of attitude networks depends almost entirely on their level of connectivity,
with more central attitude elements having stronger impact. The impact of
attitudes on voting behaviour can thus be reliably determined before elections
take place by using network analyses.Comment: Final version published in Scientific Report
When the clinic is not yet built … the Avian Park Service Learning Centre story
The Ukwanda Centre for Rural Health (UCRH) opened in 2001, followed 10 years later by the establishment of the Ukwanda Rural Clinical School in one of the rural health districts of the Western Cape. This paper relates the journey of the Faculty with the underserviced community of Avian Park through the provision of healthcare services aimed at addressing needs identified by the local community. It attempts to substantiate the meaning of the word Ukwanda, translated ‘to grow’ and ‘develop within the community’ in order to reach the primary goal of being an ‘engaged institution’. The Avian Park Service Learning Centre (APSLC) is the culmination of the aspirations of a number of stakeholders who wanted to respond to the community needs for access to basic healthcare while providing learning opportunities for students. Initially only patients with chronic diseases of lifestyle, tuberculosis (TB) and HIV/AIDS were seen by community care-workers (CCWs). Through a number of service-learning initiatives in Avian Park, a variety of health services have developed in the community. CCWs have become teachers, community developers and an integral part of the health service team. They enhance access to the residents, community projects and networking within the community.The APSLC improves the opportunities to integrate theoretical academic work with practical application, providing students with a unique opportunity to be involved in healthcare service design and development (as active participants, not observers) based on community-identified needs. University and community collaboration has been purposeful and aims to strengthen community engagement, while up-skilling residents and affording community-based education opportunities for health professions
On the Cause of the Mid‐Pleistocene Transition
The Mid-Pleistocene Transition (MPT), where the Pleistocene glacial cycles changed from 41 to ∼100 kyr periodicity, is one of the most intriguing unsolved issues in the field of paleoclimatology. Over the course of over four decades of research, several different physical mechanisms have been proposed to explain the MPT, involving non-linear feedbacks between ice sheets and the global climate, the solid Earth, ocean circulation, and the carbon cycle. Here, we review these different mechanisms, comparing how each of them relates to the others, and to the currently available observational evidence. Based on this discussion, we identify the most important gaps in our current understanding of the MPT. We discuss how new model experiments, which focus on the quantitative differences between the different physical mechanisms, could help fill these gaps. The results of those experiments could help interpret available proxy evidence, as well as new evidence that is expected to become available
On the Cause of the Mid-Pleistocene Transition
The Mid-Pleistocene Transition (MPT), where the Pleistocene glacial cycles changed from 41 to ∼100 kyr periodicity, is one of the most intriguing unsolved issues in the field of paleoclimatology. Over the course of over four decades of research, several different physical mechanisms have been proposed to explain the MPT, involving non-linear feedbacks between ice sheets and the global climate, the solid Earth, ocean circulation, and the carbon cycle. Here, we review these different mechanisms, comparing how each of them relates to the others, and to the currently available observational evidence. Based on this discussion, we identify the most important gaps in our current understanding of the MPT. We discuss how new model experiments, which focus on the quantitative differences between the different physical mechanisms, could help fill these gaps. The results of those experiments could help interpret available proxy evidence, as well as new evidence that is expected to become available
Fused Deposition Modelling of Fibre Reinforced Polymer Composites: A Parametric Review
Fused deposition modelling (FDM) is a widely used additive layer manufacturing process that deposits thermoplastic material layer-by-layer to produce complex geometries within a short time. Increasingly, fibres are being used to reinforce thermoplastic filaments to improve mechanical performance. This paper reviews the available literature on fibre reinforced FDM to investigate how the mechanical, physical, and thermal properties of 3D-printed fibre reinforced thermoplastic composite materials are affected by printing parameters (e.g., printing speed, temperature, building principle, etc.) and constitutive materials properties, i.e., polymeric matrices, reinforcements, and additional materials. In particular, the reinforcement fibres are categorized in this review considering the different available types (e.g., carbon, glass, aramid, and natural), and obtainable architectures divided accordingly to the fibre length (nano, short, and continuous). The review attempts to distil the optimum processing parameters that could be deduced from across different studies by presenting graphically the relationship between process parameters and properties. This publication benefits the material developer who is investigating the process parameters to optimize the printing parameters of novel materials or looking for a good constituent combination to produce composite FDM filaments, thus helping to reduce material wastage and experimental time
Characterization of mucus glycoproteins in the intestinal mucosa of the African elephant (Loxodonta africana) following lectin histochemistry
The glycoproteins of the small intestines, caecum and colon of three adult elephants and one recently
weaned elephant calf were examined by means of lectin histochemistry. Tissue sections were histochemically
stained with peroxidase-labelled concanavalin A (Con A), asparagus-pea (TPA), peanut
(PNA) and wheat-germ (WGA) lectins. Con A and TPA showed no binding activity in the intestinal tract
of the adult elephants or the duodenum and ileum of the elephant calf, but did show a small amount of
binding activity in the caecum and colon of the calf. WGA bound very intensely throughout the intestinal
tracts of the adults and of the calf - especially with the goblet cells located in the crypts of Lieberkuhn
and the glands of Brunner - decreasing in intensity towards the luminal surface of the intestinal tract.
PNA stained the glands of Brunner of the duodenum faintly and the goblet cells of the ileum moderately,
with no staining of the caecum and faint staining of the colon. These results show the distribution of
Con A-, WGA-, PNA- and TPA-binding sites, and the changes that take place in the type of glycoprotein
secreted after a change in the diet of the animal.The articles have been scanned in colour with a HP Scanjet 5590; 600dpi.
Adobe Acrobat XI Pro was used to OCR the text and also for the merging and conversion to the final presentation PDF-format.mn201
Рестрикционное картирование внехромосомного элемента рСА25 Erwinia carotovora
Проведено фiзичне картування позахромосомного елемента рСА25 Erwinia carotovora i його транспозонного варiанта рСА25::Tn9. Плазмiда рСА25 належить до найбiльш поширеного серед ервiнiй розмiрного класу позахромосомних ДНК завдовжки 9,8 т. п. н. На основi отриманих даних побудовано попередню рестрикцiйну карту плазмiди i виявлено мiсце вбудовування транспозону Tn9 у плазмiдну ДНК.The restriction site mapping of Erwinia carotovora’s extrachromosomal element pCA25 and its transposon variant рСА25::Tn9 has been performed. Plasmid pCA25 belongs to the most widespread size class of erwinia’s extrachromosomal DNAs 9.8 kb. The preliminary restriction map of the plasmid has been created, and the site of the Tn9 transposon incorporation has been detected corresponding to the obtained data
Remanufacturing of woven carbon fibre fabric production waste into high performance aligned discontinuous fibre composites
A 1.5-million-year record of orbital and millennial climate variability in the North Atlantic
Climate during the last glacial period was marked by abrupt instability on millennial timescales that included large swings of temperature in and around Greenland (Daansgard-Oeschger events) and smaller, more gradual changes in Antarctica (AIM events). Less is known about the existence and nature of similar variability during older glacial periods, especially during the early Pleistocene when glacial cycles were dominantly occurring at 41 kyr intervals compared to the much longer and deeper glaciations of the more recent period. Here, we report a continuous millennially resolved record of stable isotopes of planktic and benthic foraminifera at IODP Site U1385 (the "Shackleton Site") from the southwestern Iberian margin for the last 1.5 million years, which includes the Middle Pleistocene Transition (MPT). Our results demonstrate that millennial climate variability (MCV) was a persistent feature of glacial climate, both before and after the MPT. Prior to 1.2 Ma in the early Pleistocene, the amplitude of MCV was modulated by the 41 kyr obliquity cycle and increased when axial tilt dropped below 23.5° and benthic δ18O exceeded ∼3.8 ‰ (corrected to Uvigerina), indicating a threshold response to orbital forcing. Afterwards, MCV became focused mainly on the transitions into and out of glacial states (i.e. inceptions and terminations) and during times of intermediate ice volume. After 1.2 Ma, obliquity continued to play a role in modulating the amplitude of MCV, especially during times of glacial inceptions, which are always associated with declining obliquity. A non-linear role for obliquity is also indicated by the appearance of multiples (82, 123 kyr) and combination tones (28 kyr) of the 41 kyr cycle. Near the end of the MPT (∼0.65 Ma), obliquity modulation of MCV amplitude wanes as quasi-periodic 100 kyr and precession power increase, coinciding with the growth of oversized ice sheets on North America and the appearance of Heinrich layers in North Atlantic sediments. Whereas the planktic δ18O of Site U1385 shows a strong resemblance to Greenland temperature and atmospheric methane (i.e. Northern Hemisphere climate), millennial changes in benthic δ18O closely follow the temperature history of Antarctica for the past 800 kyr. The phasing of millennial planktic and benthic δ18O variation is similar to that observed for MIS 3 throughout much of the record, which has been suggested to mimic the signature of the bipolar seesaw - i.e. an interhemispheric asymmetry between the timing of cooling in Antarctica and warming in Greenland. The Iberian margin isotopic record suggests that bipolar asymmetry was a robust feature of interhemispheric glacial climate variations for at least the past 1.5 Ma despite changing glacial boundary conditions. A strong correlation exists between millennial increases in planktic δ18O (cooling) and decreases in benthic δ13C, indicating that millennial variations in North Atlantic surface temperature are mirrored by changes in deep-water circulation and remineralization of carbon in the abyssal ocean. We find strong evidence that climate variability on millennial and orbital scales is coupled across different timescales and interacts in both directions, which may be important for linking internal climate dynamics and external astronomical forcing. Copyright
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