On Public Knowledge

In “Elusive Knowledge”, Lewis begins by saying that we know a lot of trite information about the ordinary world. I know what carrots are. I know how to drive a car. I know that when someone greets me and holds out their hand, they expect me to shake it and so on. However, when we talk in philosophical terms about knowledge, we have no reason to say that we really know anything. There seem to be two contexts of knowing something. Regarding the everyday, general type of knowledge, I know a lot. But when I put on my philosopher’s hat, it looks like I can’t say I really know very much at all. As a result, it is argued that either we know lots of things, or we must submit to skepticism. (first paragraph

Control of Proteolysis during the Caulobacter Cell Cycle

Intracellular protein destruction is a carefully coordinated and timed regulatory mechanism that cells utilize to modulate growth, adaptation to environmental cues, and survival. In Caulobacter crescentus, a bacterium known for studies of bacterial cell division cycle, the response regulator CpdR couples phosphorylation events with the AAA+ protease ClpXP to provide punctuated degradation of crucial substrates involved in cell cycle regulation. CpdR functions like an adaptor to alter substrate choice by ClpXP, however it remains unclear how CpdR influences its multiple targets. In this thesis, we show that, unlike canonical ClpXP adaptors, CpdR alone does not strongly bind its substrate. Instead, CpdR binds the N-terminal domain of ClpX and prepares (primes) the unfoldase for substrate engagement. This priming creates a recruitment interface that docks multiple substrates and additional adaptor components. Interestingly, adaptor-dependent priming of ClpX avoids concentration-dependent inhibition that limits traditional, scaffolding adaptors. Control of proteolysis during the Caulobacter cell cycle occurs through proteins involved in a complex phosphosignaling network. We show that this phosphosignal disrupts the interaction between CpdR and ClpX. This regulatory mechanism is efficient because phosphorylated CpdR that cannot bind ClpX should, theoretically, free ClpXP for interaction with its other substrates and adaptors. When dephosphorylated, CpdR binds ClpX, allowing ClpXP to temporarily gain capability to target a completely different range of proteins. Mutations in the predicted response regulator output face of CpdR yielded CpdR variants that impact ClpX binding to cause ranked-order change in adaptor activity and biological function. Through a suppressor mutant screen of a CpdR variant that is hugely defective in binding ClpX, we discover a non-phosphorylatable activated variant of CpdR. Our data suggest that this CpdR variant may have adopted a Mg2+-free conformation, giving us insight to the dynamic states that CpdR can adopt during its regulatory function. Together, these results reveal how a single adaptor can command global changes in proteome composition through priming of a protease

Our Charitable Children

"Charity is a really big word, a really big deal…because it means so many things and is a way of helping so many people... it’s a very big word" (Girl, aged 7) This report presents qualitative evidence from an in-depth, participative action research project with 150 young children aged 4-8 years old regarding their perceptions and experiences of charity and charitable giving. Most young children positively engage in charitable giving through home, school and their community, however less than 20% are aware of the cause area they are being asked to support, and most have little decision making in their giving. Children’s willingness to give increases when they critically engage in the cause area and are facilitated to lead on giving decisions, coupled by increased and sustained efforts to support cause areas that matter to them

Long-Duration Space Exploration and Emotional Health: Recommendations for Conceptualizing and Evaluating Risk.

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.Spaceflight to Mars will by far exceed the duration of any previous mission. Although behavioral health risks are routinely highlighted among the most serious threats to crew safety, understanding of specific emotional responses most likely to occur and interfere with mission success has lagged in comparison to other risk domains. Even within the domain of behavioral health, emotional constructs remain to be ‘unpacked’ to the same extent as other factors such as attention and fatigue. The current paper provides a review of previous studies that have examined emotional responses in isolated, confined, extreme environments (ICE) toward informing a needed research agenda. We include research conducted during space flight, long-duration space simulation analogs, and polar environments and utilize a widely-accepted and studied model of emotion and emotion regulation by Gross [6] to conceptualize specific findings. Lastly, we propose four specific directions for future research: (1) use of a guiding theoretical framework for evaluating emotion responses in ICE environments; (2) leveraging multi-method approaches to improve the reliability of subjective reports of emotional health; (3) a priori selection of precise emotional constructs to guide measure selection; and (4) focusing on positive in addition to negative emotion in order to provide a more complete understanding of individual risk and resilience

Differential effects of calcium- and vitamin D-fortified milk with FOS-inulin compared to regular milk, on bone biomarkers in Chinese pre- and postmenopausal women

PURPOSE: To compare the effects of a high-calcium vitamin D-fortified milk with added FOS-inulin versus regular milk on serum parathyroid hormone, and bone turnover markers in premenopausal (Pre-M) and postmenopausal (PM) women over 12 weeks. METHODS: Premenopausal women (n = 136, mean age 41 (±5) years) and postmenopausal women [n = 121, mean age 59 (±4) years] were recruited, and each age group randomised into two groups to take two glasses per day of control = regular milk (500 mg calcium per day) or intervention (Int) = fortified milk (1000 mg calcium for pre-M women and 1200 mg calcium for PM women, 96 mg magnesium, 2.4 mg zinc, 15 µg vitamin D, 4 g FOS-inulin per day). At baseline, week 4 and week 12 serum minerals and bone biochemical markers were measured and bone density was measured at baseline. RESULTS: Mean 25-hydroxyvitamin D [25(OH) vitamin D3] levels among groups were between 49 and 65 nmol/L at baseline, and over the 12 weeks of supplementation, the fortified milk improved vitamin D status in both Int groups. CTx-1 and PINP reduced significantly in both Pre-M and PM groups over the 12 weeks, with the changes in CTx-1 being significantly different (P < 0.035) between PM control and PM Int groups at week 12. Parathyroid hormone levels were significantly reduced in all groups over time, except for control PM group where levels increased at 12 weeks. CONCLUSION: The overall pattern of responses indicates that while both regular milk and fortified milk reduce bone resorption in young and older women, fortified milk is measurably more effective

The protection of Victoria Harbour in Hong Kong : an analysis of civic engagement strategies

published_or_final_versionPolitics and Public AdministrationMasterMaster of Public Administratio

Temporal control of gene deletion in sensory ganglia using a tamoxifen-inducible Advillin-Cre-ERT2 recombinase mouse

<p>Abstract</p> <p>Background</p> <p>Tissue-specific gene deletion has proved informative in the analysis of pain pathways. <it>Advillin </it>has been shown to be a pan-neuronal marker of spinal and cranial sensory ganglia. We generated BAC transgenic mice using the <it>Advillin </it>promoter to drive a tamoxifen-inducible CreERT2 recombinase construct in order to be able to delete genes in adult animals. We used a floxed stop <it>ROSA26LacZ </it>reporter mouse to examine functional Cre expression, and analysed the behaviour of mice expressing Cre recombinase.</p> <p>Results</p> <p>We used recombineering to introduce a CreERT2 cassette in place of exon 2 of the <it>Advillin </it>gene into a BAC clone (RPCI23-424F19) containing the 5' region of the <it>Advillin </it>gene. Transgenic mice were generated using pronuclear injection. The resulting <it>AvCreERT2 </it>transgenic mice showed a highly specific expression pattern of Cre activity after tamoxifen induction. Recombinase activity was confined to sensory neurons and no expression was found in other organs. Less than 1% of neurons showed Cre expression in the absence of tamoxifen treatment. Five-day intraperitoneal treatment with tamoxifen (2 mg per day) induced Cre recombination events in ≈90% of neurons in dorsal root and cranial ganglia. Cell counts of dorsal root ganglia (DRG) from transgenic animals with or without tamoxifen treatment showed no neuronal cell loss. Sensory neurons in culture showed ≈70% induction after 3 days treatment with tamoxifen. Behavioural tests showed no differences between wildtype, <it>AvCreERT2 </it>and tamoxifen-treated animals in terms of motor function, responses to light touch and noxious pressure, thermal thresholds as well as responses to inflammatory agents.</p> <p>Conclusions</p> <p>Our results suggest that the inducible pan-DRG <it>AvCreERT2 </it>deleter mouse strain is a useful tool for studying the role of individual genes in adult sensory neuron function. The pain phenotype of the Cre-induced animal is normal; therefore any alterations in pain processing can be unambiguously attributed to loss of the targeted gene.</p

Genomic DNA functions as a universal external standard in quantitative real-time PCR

Real-time quantitative PCR (qPCR) is a powerful tool for quantifying specific DNA target sequences. Although determination of relative quantity is widely accepted as a reliable means of measuring differences between samples, there are advantages to being able to determine the absolute copy numbers of a given target. One approach to absolute quantification relies on construction of an accurate standard curve using appropriate external standards of known concentration. We have validated the use of tissue genomic DNA as a universal external standard to facilitate quantification of any target sequence contained in the genome of a given species, addressing several key technical issues regarding its use. This approach was applied to validate mRNA expression of gene candidates identified from microarray data and to determine gene copies in transgenic mice. A simple method that can assist achieving absolute quantification of gene expression would broadly enhance the uses of real-time qPCR and in particular, augment the evaluation of global gene expression studies

Ultrafiltration versus diuretics on prognostic cardiac and renal biomarkers in acute decompensated heart failure : a systematic review and meta-analysis

Peer reviewedPublisher PD

Genome and Transcriptome of Clostridium phytofermentans, Catalyst for the Direct Conversion of Plant Feedstocks to Fuels

International audienceClostridium phytofermentans was isolated from forest soil and is distinguished by its capacity to directly ferment plant cell wall polysaccharides into ethanol as the primary product, suggesting that it possesses unusual catabolic pathways. The objective of the present study was to understand the molecular mechanisms of biomass conversion to ethanol in a single organism, Clostridium phytofermentans, by analyzing its complete genome and transcriptome during growth on plant carbohydrates. The saccharolytic versatility of C. phytofermentans is reflected in a diversity of genes encoding ATP-binding cassette sugar transporters and glycoside hydrolases, many of which may have been acquired through horizontal gene transfer. These genes are frequently organized as operons that may be controlled individually by the many transcriptional regulators identified in the genome. Preferential ethanol production may be due to high levels of expression of multiple ethanol dehydrogenases and additional pathways maximizing ethanol yield. The genome also encodes three different proteinaceous bacterial microcompartments with the capacity to compartmentalize pathways that divert fermentation intermediates to various products. These characteristics make C. phytofermentans an attractive resource for improving the efficiency and speed of biomass conversion to biofuels