275 research outputs found
Modelling of Thermal Sterilization of high-moisture snack foods: feasibility analysis and optimization
High-moisture snacks, such as steamed buns and rice cakes, are traditional and popular in Asian countries. However, their shelf life is short, primarily due to microbial spoilage. Current manufacturing methods address this shortcoming through the use of chemical preservatives. To satisfy consumersâ demand for preservative-free food, thermal sterilization of a model high-moisture snack (steamed rice cakes) is investigated in this work. Bacillus cereus spores are heat-resistant pathogens typically found in rice products; hence, they constitute a suitable candidate to assess the effectiveness of thermal sterilization. A validated combination of predicted temperature profile of rice cakes based on thermal properties extracted experimentally with thermal inactivation kinetics of B. cereus spores allows us to assess the sensitivity of processing conditions to sterilization efficiency. Using both experimentation and modelling, it is shown that enhancement of heat transfer by improving convection from the heating medium (either water or steam) has a limited effect on inactivation due to the intrinsic kinetics of spore inactivation
Human rhinovirus-induced inflammatory responses are inhibited by phosphatidylserine containing liposomes
Human rhinovirus (HRV) infections are major contributors to the healthcare burden associated with acute exacerbations of chronic airway disease, such as chronic obstructive pulmonary disease and asthma. Cellular responses to HRV are mediated through pattern recognition receptors that may in part signal from membrane microdomains. We previously found Toll-like receptor signaling is reduced, by targeting membrane microdomains with a specific liposomal phosphatidylserine species, 1-stearoyl-2-arachidonoyl-sn-glycero-3-phospho-L-serine (SAPS). Here we explored the ability of this approach to target a clinically important pathogen. We determined the biochemical and biophysical properties and stability of SAPS liposomes and studied their ability to modulate rhinovirus-induced inflammation, measured by cytokine production, and rhinovirus replication in both immortalized and normal primary bronchial epithelial cells. SAPS liposomes rapidly partitioned throughout the plasma membrane and internal cellular membranes of epithelial cells. Uptake of liposomes did not cause cell death, but was associated with markedly reduced inflammatory responses to rhinovirus, at the expense of only modest non-significant increases in viral replication, and without impairment of interferon receptor signaling. Thus using liposomes of phosphatidylserine to target membrane microdomains is a feasible mechanism for modulating rhinovirus-induced signaling, and potentially a prototypic new therapy for viral-mediated inflammation
A first-in-human phase I study to determine the maximum tolerated dose of the oral Src/ABL inhibitor AZD0424
BACKGROUND: Src is involved in cancer invasion and metastasis. AZD0424, an oral inhibitor of Src and ABL1, has shown evidence of anti-tumour activity in pre-clinical studies. METHODS: A phase Ia, dose escalation study was performed to assess the safety of continuous oral dosing with AZD0424 in advanced solid tumours. Secondary objectives included investigation of AZD0424 pharmacokinetics, effect on Src activity using markers of bone turnover, and anti-tumour activity. RESULTS: 41 patients were treated; 34 received AZD0424 once-daily at doses ranging from 5âmg to 150âmg, and 7 received 40âmg bi-daily 41.5% of patients experienced at least one AZD0424-related adverse event that was Grade 3-5 in severity, with patients treated at doses above 60âmg per day experiencing multiple treatment-related toxicities. The most commonly observed AZD0424-related adverse events were nausea, fatigue, anorexia and alopecia. Cmaxand AUC increased linearly with dose and the mean±standard deviation t1/2was 8.4±2.8âh. Clear evidence of Src target inhibition was seen at doses â©Ÿ20âmg per day. No responses were observed and 7 patients (17.1%) achieved stable disease lasting 6 weeks or more. CONCLUSIONS: AZD0424 displayed no evidence of efficacy as monotherapy despite a clear pharmacodynamic effect. Further evaluation of AZD0424 monotherapy in patients with solid tumours is not recommended
Virus infection and grazing exert counteracting influences on survivorship of native bunchgrass seedlings competing with invasive exotics
1. âInvasive annual grasses introduced by European settlers have largely displaced native grassland vegetation in California and now form dense stands that constrain the establishment of native perennial bunchgrass seedlings. Bunchgrass seedlings face additional pressures from both livestock grazing and barley and cereal yellow dwarf viruses (B/CYDVs), which infect both young and established grasses throughout the state. 2. âPrevious work suggested that B/CYDVs could mediate apparent competition between invasive exotic grasses and native bunchgrasses in California. 3. âTo investigate the potential significance of virus-mediated mortality for early survivorship of bunchgrass seedlings, we compared the separate and combined effects of virus infection, competition and simulated grazing in a field experiment. We infected two species of young bunchgrasses that show different sensitivity to B/CYDV infection, subjected them to competition with three different densities of exotic annuals crossed with two clipping treatments, and monitored their growth and first-year survivorship. 4. âAlthough virus infection alone did not reduce first-year survivorship, it halved the survivorship of bunchgrasses competing with exotics. Within an environment in which competition strongly reduces seedling survivorship (as in natural grasslands), virus infection therefore has the power to cause additional seedling mortality and alter patterns of establishment. 5. âSurprisingly, clipping did not reduce bunchgrass survivorship further, but rather doubled it and disproportionately increased survivorship of infected bunchgrasses. 6. âTogether with previous work, these findings show that B/CYDVs can be potentially powerful elements influencing species interactions in natural grasslands. 7. âMore generally, our findings demonstrate the potential significance of multitrophic interactions in virus ecology. Although sometimes treated collectively as plant âpredatorsâ, viruses and herbivores may exert influences that are distinctly different, even counteracting
Single-grain and multi-grain OSL dating of river terrace sediments in the Tabernas Basin, SE Spain
River terraces represent important records of landscape response to e.g. base-level change and tectonic movement. Both these driving forces are important in the southern Iberian Peninsula. In this study, Optically Stimulated Luminescence (OSL) dating was used to date two principal river terraces in the Tabernas Basin, SE Spain. A total of 23 samples was collected from the fluvial terraces for dating using quartz OSL. Sixteen of the samples could not be dated because of low saturation levels (e.g. typical 2xD0 < 50 Gy). The remaining seven samples (5 fossil and 2 modern analogues) were investigated using both multi-grain and single-grain analysis. Single grain results show that: (i) measurements from multi-grain aliquots overestimate ages by up to ⌠4 ka for modern analogues and young samples (<5 ka), presumably because (ii) the presence of many saturated grains has biased the multi-grain results to older ages. Despite the unfavourable luminescence characteristics we are able to present the first numerical ages for two terrace aggradation stages in the Tabernas Basin, one at âŒ16 ka and the other within the last 2 ka
A Bayesian analysis of pentaquark signals from CLAS data
We examine the results of two measurements by the CLAS collaboration, one of
which claimed evidence for a pentaquark, whilst the other found no
such evidence. The unique feature of these two experiments was that they were
performed with the same experimental setup. Using a Bayesian analysis we find
that the results of the two experiments are in fact compatible with each other,
but that the first measurement did not contain sufficient information to
determine unambiguously the existence of a . Further, we suggest a
means by which the existence of a new candidate particle can be tested in a
rigorous manner.Comment: 5 pages, 3 figure
First measurement of direct photoproduction on the proton
We report on the results of the first measurement of exclusive
meson photoproduction on protons for GeV and GeV. Data were collected with the CLAS detector at the Thomas
Jefferson National Accelerator Facility. The resonance was detected via its
decay in the channel by performing a partial wave analysis of the
reaction . Clear evidence of the meson
was found in the interference between and waves at GeV. The -wave differential cross section integrated in the mass range of
the was found to be a factor of 50 smaller than the cross section
for the meson. This is the first time the meson has been
measured in a photoproduction experiment
Controls on dryland mountain landscape development along the NW Saharan desert margin: Insights from Quaternary river terrace sequences (DadĂšs River, south-central High Atlas, Morocco)
This study documents river terraces from upstream reaches of the Dad es River, a major fluvial system
draining the south-central High Atlas Mountains. Terraces occur as straths with bedrock bases positioned
at 10 m altitudinal intervals up to 40 m (T1-T5) above the valley floor, becoming less common between
50 and 140 m. The rock strength, stratigraphy and structure of the mountain belt influences terrace
distribution. Terraces are absent in river gorges of structurally thickened limestone; whilst welldeveloped,
laterally continuous terraces (T1-T4) form along wide valleys occupying syncline structures
dominated by weaker interbedded limestone-mudstone. Terrace staircases develop in confined canyons
associated with weaker lithologies and influence from structural dip and stratigraphic configuration.
Terraces comprise a bedrock erosion surface overlain by fluvial conglomerates, rare overbank sands
and colluvium. This sequence with some OSL/IRSL age control, suggests terrace formation over a 100 ka
climate cycle with valley floor aggradation during full glacials and incision during glacial-interglacial
transitions. This integrates with other archives (e.g. lakes, glaciers, dunes), appearing typical of landscape
development along the NW Saharan margin south of the High Atlas, and similar to patterns in the
western-southern Mediterranean. The 100 ka climate cycle relationship suggests that the terrace
sequence documents Late-Middle Pleistocene landscape development.
Consistent altitudinal spacing of terraces and their distribution throughout the orogen suggests sustained
base-level lowering linked to uplift-exhumation of the High Atlas. Low incision rates (<0.2 mm
a 1) and general absence of terrace deformation suggests dominance of isostatically driven base-level
lowering with relief generation being Early Pleistocene or older.National Geographic research grant (8609-09
Central Santa Catarina coastal dunefields chronology and their relation to relative sea level and climatic changes
During the past decades, there have been contrarian explanations for the formation and stabilization of coastal dunefields: while many authors believe the dunes formation would be enhanced by falling sea level, others argue that a rising or stable sea level context would be favorable. For Brazilian coastal dunefields, the second hypothesis seems to be more consistent with the luminescence ages found so far; however, most of these data were obtained without using the SAR protocol. Another point of concern is the role of climate change in the aeolian system, which is still not very clear. The aim of this paper is to try to clarify these two questions. To this end, five coastal dunefields were selected in central Santa Catarina coast. The remote sensing and dating results allowed the discrimination and mapping of at least four aeolian generations. Their age distribution in relation to the global curve of relative sea level variation during the Late Pleistocene allows us to suggest that the formation of Aeolian dunefields in the coastal context is supported by stable relative sea level. However, relative sea level is not the only determinant for the formation and preservation of the aeolian coastal dunes. Evidences of climatic control indicate that the initiation of dunefields would be favored by periods of less humidity while their stabilization would occur preferably during the periods of rain intensification, connected to monsoon activity
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