1,154 research outputs found
The effect of integrin a1b1 on Smad2/3 and phosphoSmad2/3 expression in murine chondrocytes
Background: Chondrocytes, the cells of cartilage, maintain and repair the extracellularmatrix by secreting and degrading proteins such as collagen type II andaggrecan.1 Integrins are transmembrane adhesion proteins that cells use to both bindto and sense the extracellular matrix. Chondrocytes express many different types ofintegrin molecules and this study focuses on the collagen II and VI receptor integrina1b1. Transforming growth factor-beta (TGF-b) stimulates chondrocytes to repaircartilage through a number of intracellular pathways of which the Smad2/3 pathwayis a known major fibrotic pathway.2 An excess build-up of bony tissue leads to theformation of fibrotic osteoarthritis (OA) in integrin a1-null mice at an earlier age andto a more severe extent than wild type controls.3 Based on these data we hypothesizethat integrin a1b1 controls the sensitivity of chondrocytes to TGF-b. When integrina1b1 is missing chondrocytes are oversensitive to TGF-b, possibly through Smad2/3pathway up regulation. The objective of this experiment is to measure the proteinlevels of Smad2/3 and phosphoSmad2/3 in wild type and integrin a1-null murinechondrocytes. We expect up regulation of phosphoSmad2/3 in integrin a1-null micecompared to wild-type controls.3Methods: Enzymatically isolated chondrocytes from 4-6 month old mice weresonicated and the released protein concentrated through centrifugal filtration. Proteinwas measured through Western-blotting analysis.Results: Integrin a1-null murine chondrocytes contain Smad2.Discussion: Smad2 has been shown in wild-type chondrocytes, but not previously inintegrin a1-null chondrocytes.4 However, Smad2/3 and up-regulated phosphoSmad2/3have been found in integrin a1-null renal medulla cells.2 With further development oftechniques, Smad3 and phosphoSmad2/3 will be measured in wild-type and integrina1-null murine chondrocytes and thus the pathway for fibrotic OA in integrin a1-nullmice can be further determined
Warming temperatures increase microbial consumption of marine organic matter
Marine microbes are vital to oceanic ecosystems and influence the global climate through their paramount role in Earth’s biogeochemical cycles. With this intricate role in ecosystems, it is important to understand the effect of increasing ocean temperatures on the cycling of organic matter (OM), which is hypothesized to contribute a positive feedback to future warming via an acceleration in microbial respiration of OM to CO2. We experimentally investigated the temperature sensitivity of microbial consumption of marine particulate OM focused in the rapidly warming Gulf of Maine during the 2019 and 2020 Fall phytoplankton bloom. The overall rate and quantity of microbial OM (C, N, and P pools) consumption at in situ versus elevated temperatures were quantified within bottle incubations over the course of two weeks. The results indicate that OM incubated at warmer temperatures (+5 – 6°C) was consumed at a faster rate with an overall larger quantity consumed compared to cooler temperatures (12 – 14°C). Additionally, nitrate that initially accumulated from the consumption of particulate organic nitrogen (PON), was readily consumed at later time points at both temperatures, possibly related to the carbon-rich, nitrogen-poor quality of the in situ OM. In 2020, more nitrogen-rich OM was preferentially consumed at cooler temperatures, leaving behind carbon-rich OM. Whereas at warmer temperatures, carbon-rich OM was preferentially consumed presumably due to it being a bioavailable energy source to fuel elevated metabolic rates. The empirically estimated temperature coefficient (Q10) ranged from 2.66 – 3.42 in 2019 versus 0.94 – 1.21 in 2020, dependent on the OM elemental pool, suggesting temperature plays an important role in OM consumption, but is not the only factor contributing to the rates and magnitude of OM consumption by marine microbes
'Like-With-Like’: A Comparison of Natural and Synthetic Stitching Threads used in Textile Conservation
This paper reports research undertaken to investigate
thread types used in textile conservation
by quantitatively evaluating tensile strength and
damage to conserved samples. A literature review
and questionnaire sent to textile conservators
were used to establish the most commonly used
threads for laid-thread couching treatments and
the rationale behind thread choice. Most common
threads found were two-ply hair silk and polyester
Tetex as well as other fine polyester, silk and cotton
varieties. Three natural fibre plain-weave artefact
samples conserved by laid-thread couching with
five different thread types (lace cotton, hair silk,
organsin, Skala and Tetex) were subjected to either
tensile strength testing or a fixed-load experiment
for two weeks. The tensile strength tests determined
that the conservation treatment provided
effective support and different thread types did
not give statistically different results. The fixed-load
experiment determined that longer time periods
created more damage, even with lighter loads
Mapping teachers' preparedness to teach and support children on the autism spectrum in Ras Al Khaimah
According to the World Health Organization, autism is one of the most common disabilities in the world. The number of children with a diagnosis of autism continues to rise globally, including in the United Arab Emirates (UAE). Research has established that appropriate educational provision is one of the best ways to support children and young people on the autism spectrum and that teacher attitudes have a significant influence on the inclusion of these students in school. However, very little research has been undertaken in the UAE. To address this gap, this study was conducted in Ras Al Khaimah to understand teachers' current knowledge and attitudes toward students on the autism spectrum. Using an online questionnaire, thirty-nine responses were collected from Ras Al Khaimah teachers. The results show that teachers have a mixed knowledge of autism; they demonstrate a good understanding of autism in some areas but also lack information or knowledge in others. Similarly, while they are in favor of inclusive education as a concept, they also expressed concerns about including students who may need additional support because of their communication or behavioral differences. Based on the research findings, this paper recommends steps that can be taken to increase inclusive educational practices for students on the autism spectrum in the emirate
The suitcase, the samurai sword and the Pumpkin: Asian crime and NZ news media treatment
In 2005 and 2007, two high profile crimes were reported in the New Zealand media. The first case invovled the murder of a young Chinese student, Wan Biao, whose dismembered body was discovered in a suitcase. The second case involved domestic violence in which a Chinese man murdered his wife and fled the scene with their young daughter— who the press later dubbed 'Pumpkin' when she was found abandoned in Melbourne, Australia. The authors discuss how news and current affairs programmes decontextualise 'Asian' stories to portray a clear divide between the 'New zealand' public and the separate 'Asian other'. Asians are portrayed as a homogenous group and the media fails to distinguish between Asians as victims of crimes as a separate category to Asians as perpetrators of crimes. This may have consequences for the New Zealand Asian communities and the wider New Zealand society as a whole. 
Mapping teachers' preparedness to teach and support children on the autism spectrum in Ras Al Khaimah
According to the World Health Organization, autism is one of the most common disabilities in the world. The number of children with a diagnosis of autism continues to rise globally, including in the United Arab Emirates (UAE). Research has established that appropriate educational provision is one of the best ways to support children and young people on the autism spectrum and that teacher attitudes have a significant influence on the inclusion of these students in school. However, very little research has been undertaken in the UAE. To address this gap, this study was conducted in Ras Al Khaimah to understand teachers' current knowledge and attitudes toward students on the autism spectrum. Using an online questionnaire, thirty-nine responses were collected from Ras Al Khaimah teachers. The results show that teachers have a mixed knowledge of autism; they demonstrate a good understanding of autism in some areas but also lack information or knowledge in others. Similarly, while they are in favor of inclusive education as a concept, they also expressed concerns about including students who may need additional support because of their communication or behavioral differences. Based on the research findings, this paper recommends steps that can be taken to increase inclusive educational practices for students on the autism spectrum in the emirate
The Dwarfs Beyond: The Stellar-to-Halo Mass Relation for a New Sample of Intermediate Redshift Low Mass Galaxies
A number of recent challenges to the standard Lambda-CDM paradigm relate to
discrepancies that arise in comparing the abundance and kinematics of local
dwarf galaxies with the predictions of numerical simulations. Such arguments
rely heavily on the assumption that the local dwarf and satellite galaxies form
a representative distribution in terms of their stellar-to-halo mass ratios. To
address this question, we present new, deep spectroscopy using DEIMOS on Keck
for 82 low mass (10^7-10^9 solar masses) star-forming galaxies at intermediate
redshift (z=0.2-1). For 50 percent of these we are able to determine resolved
rotation curves using nebular emission lines and thereby construct the stellar
mass Tully-Fisher relation to masses as low as 10^7 solar masses. Using scaling
relations determined from weak lensing data, we convert this to a
stellar-to-halo mass (SHM) relation for comparison with abundance matching
predictions. We find a discrepancy between the propagated predictions from
simulations compared to our observations, and suggest possible reasons for this
as well as future tests that will be more effective.Comment: 11 pages, 7 figures, submitted to ApJ, comments welcom
Alcohol Hangover and Multitasking: Effects on Mood, Cognitive Performance, Stress Reactivity, and Perceived Effort
The aim of this study was to examine the effects of hangover on mood, multitasking ability, and psychological stress reactivity to cognitive demand. Using a crossover design and semi-naturalistic methodology, 25 participants attended the laboratory in the morning following a night of (i) alcohol abstinence and (ii) alcohol self-administration during a typical night out (with order counterbalanced across participants). They completed a four-module multitasking framework (MTF, a widely used laboratory stressor) and a battery of questionnaires assessing mood, hangover symptom severity, and previous night’s sleep. The effects of the MTF on mood and perceived workload were also assessed. Participants in the hangover condition reported significantly lower alertness and contentment coupled with a higher mental fatigue and anxiety. Multitasking ability was also significantly impaired in the hangover condition. Completion of the cognitive stressor increased reported levels of mental demand, effort, and frustration, and decreased perceived level of performance. MTF completion did not differentially affect mood. Lastly, participants rated their sleep as significantly worse during the night prior to the hangover compared with the control condition. These findings confirm the negative cognitive and mood effects of hangover on mood. They also demonstrate that hangover is associated with greater perceived effort during task performance
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