612 research outputs found
Inert strength measurement on silica soaked at 250°C in liquid water and water vapour
The effect of water soaking and heat-treatment in saturated water vapour at
250°C for 192 h on the strength of silica glass is studied. Bending strength
meaurements in liquid nitrogen showed a clear increase of the inert strength
for heat-treated specimens over that of the untreated material. The increase
in strength is interpreted as the consequence of water diffusion into exposed
surfaces of the test specimen, which results in swelling of the glass and
shielding of cracks, present in the surface of the glass. Experimental results
are compared with theoretical predictions
Dietary restraint moderates the effects of food exposure on women's body and weight satisfaction
The influence of dietary restraint and food exposure on body satisfaction was tested. Body and weight satisfaction were measured before and after exposure to either high-or low-caloric food, without actual eating. Independent of caloric condition, higher dietary restraint was associated with a decrease in body satisfaction after food exposure. With regard to weight satisfaction, however, the association between higher dietary restraint and decreased weight satisfaction was specific for the high-caloric condition. Thus, the actual eating of food is not necessary for decreased body and weight satisfaction to occur, suggesting an exposure-induced activation of dysfunctional cognitions in restrained eaters
Evaluation of crack-terminating angles in heat-treated silica DCDC-specimens
Cracks terminating at free surfaces are affected by local stresses in the surface region. Under residual compression, the crack front must retard and under residual tensile stresses advance, both compared with the crack contour in the absence of stresses. This effect can be used for an estimation of residual surface stresses in silica generated during the silica/water reaction and caused by volume swelling. A strong shielding stress intensity factor of about -2.5 MPa was found for DCDC specimen heat-treated for 192h at 250°C in water. This result is a clear indication for compressive stresses developing in the water diffusion zone at the surface
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Learning to trust: trust and attachment in early psychosis
Background
Distrust and social dysfunction are characteristic in psychosis and may arise from attachment insecurity, which is elevated in the disorder. The relationship between trust and attachment in the early stages of psychosis is unknown, yet could help to understand interpersonal difficulties and disease progression. This study aimed to investigate whether trust is reduced in patients with early psychosis and whether this is accounted for by attachment avoidance and attachment anxiety.
Method
We used two trust games with a cooperative and unfair partner in a sample of 39 adolescents with early psychosis and 100 healthy controls.
Results
Patients had higher levels of attachment anxiety, but the groups did not differ in attachment avoidance. Basic trust was lower in patients than controls, as indicated by lower initial investments. During cooperation patients increased their trust towards levels of controls, i.e. they were able to learn and to override initial suspiciousness. Patients decreased their trust less than controls during unfair interactions. Anxious attachment was associated with higher basic trust and higher trust during unfair interactions and predicted trust independent of group status.
Discussion
Patients showed decreased basic trust but were able to learn from the trustworthy behaviour of their counterpart. Worries about the acceptance by others and low self-esteem are associated with psychosis and attachment anxiety and may explain behaviour that is focused on conciliation, rather than self-protection
Whole-plant mineral partitioning during the reproductive development of rice (Oryza sativa L.)
Minimal information exists on whole-plant dynamics of mineral flow. Understanding these phenomena in a model plant such as rice could help in the development of nutritionally enhanced cultivars. A whole-plant mineral accumulation study was performed in rice (cv. Kitaake), using sequential harvests during reproductive development panicle exertion, grain filling, and full maturity stages in order to characterize mineral accumulation in roots, non-flag leaves, flag leaves, stems/sheaths, and panicles. Partition quotient analysis showed that Fe, Zn, Cu and Ni are preferentially accumulated in roots; Mn and Mg are accumulated in leaves; Mo, Ca, and S in roots and leaves; and K in roots, leaves and stems/sheaths. Correlation analysis indicated that changes in the concentrations of mineral pairs Fe-Mn, K-S, Fe-Ni, Cu-Mg, Mn-Ni, S-Mo, Mn-Ca, and Mn-Mg throughout the reproductive development of rice were positively correlated in all four of the above ground organs evaluated, with Fe-Mn and K-S being positively correlated also in roots, which suggest that root-to-shoot transfer is not driven simply by concentrations in roots. These analyses will serve as a starting point for a more detailed examination of mineral transport and accumulation in rice plants
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Cooperation and sensitivity to social feedback during group interactions in schizophrenia
Patients with schizophrenia show reduced cooperation and less sensitivity to social cues in pairwise interactions, however, it remains unclear whether these mechanisms are also present in interactions within social groups. We used a public goods game to investigate cooperation and sensitivity to social feedback in group interactions in 27 patients with schizophrenia and 27 healthy controls. Participants played 40 trials in two conditions: 1) no fine (20 trials): participants had the choice of investing into the public good (i.e. cooperating) or not (i.e. defecting), 2) fine (20 trials): participants had the same choice but defectors could be punished by the other players. On the first trial, patients invested less in the public good than healthy controls. In the no fine condition, controls decreased their investments over time, but patients did not. The possibility of being fined for defecting and actually being fined led to significantly higher cooperation in both groups. This shows that the groups were equally sensitive to social enforcement and social feedback. Our findings suggest that patients tend to approach social group interactions with less cooperative behaviour, which could contribute to social dysfunction in daily-life. However, an intact sensitivity to social enforcement and feedback indicates that patients can adjust their behaviour accordingly in group interactions
Arabidopsis thaliana zinc accumulation in leaf trichomes is correlated with zinc concentration in leaves
Zinc (Zn) is a key micronutrient for plants and animals, and understanding Zn homeostasis in plants can improve both agriculture and human health. While root Zn transporters in plant model species have been characterized in detail, comparatively little is known about shoot processes controlling Zn concentrations and spatial distribution. Previous work showed that Zn hyperaccumulator species such as Arabidopsis halleri accumulate Zn and other metals in leaf trichomes. To date there is no systematic study regarding Zn accumulation in the trichomes of the non-accumulating, genetic model species A. thaliana. Here, we used Synchrotron X-Ray Fluorescence mapping to show that Zn accumulates at the base of trichomes of A. thaliana. Using transgenic and natural accessions of A thaliana that vary in bulk leaf Zn concentration, we demonstrate that higher leaf Zn increases total Zn found at the base of trichome cells. Our data indicates that Zn accumulation in trichomes is a function of the Zn status of the plant, and provides the basis for future studies on a genetically tractable plant species to understand the molecular steps involved in Zn spatial distribution in leaves
Pilot-scale crossflow-microfiltration and pasteurization to remove spores of Bacillus anthracis (Sterne) from milk
High-temperature, short-time pasteurization of milk
is ineffective against spore-forming bacteria such as
Bacillus anthracis (BA), but is lethal to its vegetative
cells. Crossflow microfiltration (MF) using ceramic
membranes with a pore size of 1.4 μm has been shown
to reject most microorganisms from skim milk; and,
in combination with pasteurization, has been shown to
extend its shelf life. The objectives of this study were
to evaluate MF for its efficiency in removing spores
of the attenuated Sterne strain of BA from milk; to
evaluate the combined efficiency of MF using a 0.8-μm
ceramic membrane, followed by pasteurization (72°C,
18.6 s); and to monitor any residual BA in the permeates
when stored at temperatures of 4, 10, and 25°C
for up to 28 d. In each trial, 95 L of raw skim milk
was inoculated with about 6.5 log10 BA spores/mL of
milk. It was then microfiltered in total recycle mode
at 50°C using ceramic membranes with pore sizes of
either 0.8 μm or 1.4 μm, at crossflow velocity of 6.2 m/s
and transmembrane pressure of 127.6 kPa, conditions
selected to exploit the selectivity of the membrane.
Microfiltration using the 0.8-μm membrane removed
5.91 ± 0.05 log10 BA spores/mL of milk and the 1.4-
μm membrane removed 4.50 ± 0.35 log10 BA spores/
mL of milk. The 0.8-μm membrane showed efficient
removal of the native microflora and both membranes
showed near complete transmission of the casein proteins.
Spore germination was evident in the permeates
obtained at 10, 30, and 120 min of MF time (0.8-μm
membrane) but when stored at 4 or 10°C, spore levels
were decreased to below detection levels (≤0.3 log10
spores/mL) by d 7 or 3 of storage, respectively. Permeates
stored at 25°C showed coagulation and were
not evaluated further. Pasteurization of the permeate
samples immediately after MF resulted in additional
spore germination that was related to the length of
MF time. Pasteurized permeates obtained at 10 min of
MF and stored at 4 or 10°C showed no growth of BA
by d 7 and 3, respectively. Pasteurization of permeates
obtained at 30 and 120 min of MF resulted in spore
germination of up to 2.42 log10 BA spores/mL. Spore
levels decreased over the length of the storage period
at 4 or 10°C for the samples obtained at 30 min of MF
but not for the samples obtained at 120 min of MF.
This study confirms that MF using a 0.8-μm membrane
before high-temperature, short-time pasteurization
may improve the safety and quality of the fluid milk
supply; however, the duration of MF should be limited
to prevent spore germination following pasteurization
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