8,194 research outputs found
Pyruvate Formate Lyase and Acetate Kinase are Essential for Anaerobic Growth of \u3cem\u3eEscherichia coli\u3c/em\u3e on Xylose
During anaerobic growth of bacteria, organic intermediates of metabolism, such as pyruvate or its derivatives, serve as electron acceptors to maintain the overall redox balance. Under these conditions, the ATP needed for cell growth is derived from substrate-level phosphorylation. In Escherichia coli, conversion of glucose to pyruvate yields 2 net ATPs, while metabolism of a pentose, such as xylose, to pyruvate only yields 0.67 net ATP per xylose due to the need for one (each) ATP for xylose transport and xylulose phosphorylation. During fermentative growth, E. coli produces equimolar amounts of acetate and ethanol from two pyruvates, and these reactions generate one additional ATP from two pyruvates (one hexose equivalent) while still maintaining the overall redox balance. Conversion of xylose to acetate and ethanol increases the net ATP yield from 0.67 to 1.5 per xylose. An E. coli pfl mutant lacking pyruvate formate lyase cannot convert pyruvate to acetyl coenzyme A, the required precursor for acetate and ethanol production, and could not produce this additional ATP. E. coli pfl mutants failed to grow under anaerobic conditions in xylose minimal medium without any negative effect on their survival or aerobic growth. An ackA mutant, lacking the ability to generate ATP from acetyl phosphate, also failed to grow in xylose minimal medium under anaerobic conditions, confirming the need for the ATP produced by acetate kinase for anaerobic growth on xylose. Since arabinose transport by AraE, the low-affinity, high-capacity, arabinose/H+ symport, conserves the ATP expended in pentose transport by the ABC transporter, both pfl and ackA mutants grew anaerobically with arabinose. AraE-based xylose transport, achieved after constitutively expressing araE, also supported the growth of the pfl mutant in xylose minimal medium. These results suggest that a net ATP yield of 0.67 per pentose is only enough to provide for maintenance energy but not enough to support growth of E. coli in minimal medium. Thus, pyruvate formate lyase and acetate kinase are essential for anaerobic growth of E. coli on xylose due to energetic constraints
Graduation Rate Differences by Ethnicity/Race at Texas Community Colleges: A Statewide, Multiyear Examination
In this multiyear, statewide investigation, the degree to which differences were present in graduation rates between Black and White, Black and Hispanic, and Black and Asian students was addressed for the 2007-2008 academic year to the 2015-2016 academic years. Inferential statistical procedures revealed the presence of statistically significant differences for all 9 academic years. In all 9 years, Black students had statistically significantly lower graduation rates than White, Hispanic, and Asian students. Also identified were the Texas community colleges that had the highest and that had the lowest graduation rates of their Black students in the last two academic years. Implications of these findings and recommendations for future research were discussed
Social enterprise policy design: Constructing social enterprise in the UK and Korea
Taking the elusive definition of social enterprise as its starting point, this study seeks to understand the impact of government policies on the development of social enterprises in the national contexts of the UK and South Korea. The social construction of target populations is utilised as a theoretical framework in order to identify which factors influence government policy. A comparison of the two countries over a 14-year period from 1997 to 2010 reveals that, despite very different contexts, governments in both countries have taken an instrumental approach to social enterprise. This tendency is more pronounced in Korea however, where government has limited the input of stakeholders and used an approval system to control access to the social enterprise name. The study concludes by recommending a more value-oriented approach to social enterprise
âTalent-spottingâ or âsocial magicâ? Inequality, cultural sorting and constructions of the ideal graduate in elite professions
Graduate outcomes â including rates of employment and earnings â are marked by persistent
inequalities related to social class, as well as gender, ethnicity and institution. Despite national
policy agendas related to social mobility and âfair access to the professionsâ, high-status occupations
are disproportionately composed of those from socially privileged backgrounds, and evidence
suggests that in recent decades many professions have become less socially representative.
This article makes an original contribution to sociological studies of inequalities in graduate
transitions and elite reproduction through a distinct focus on the âpre-hiringâ practices of graduate
employers. It does this through a critical analysis of the graduate recruitment material of two
popular graduate employers. It shows how, despite espousing commitments to diversity and
inclusion, constructions of the âidealâ graduate privilege individuals who can mobilise and embody
certain valued capitals. Using Bourdieusian concepts of âsocial magicâ and âinstitutional habitusâ, the
article argues that more attention must be paid to how graduate employersâ practices constitute
tacit processes of social exclusion and thus militate against the achievement of more equitable
graduate outcomes and fair access to the âtop jobs
The Student Movement Volume 107 Issue 2: We Prayed, We Changed, We Glowed: Week Three at Andrews University
HUMANS
Change Day Interview: Jessica Bowen, Interviewed by: Gloria Oh
Interview with Brandon Alvarez, Interviewed by: Grace No
Meet Andrew Rappette, AUSA Executive Vice President, Interviewed by: Lauren Kim
ARTS & ENTERTAINMENT
Change Day: Art as a Service, Skyler Campbell
Currently..., Solana Campbell
Disney\u27s D23 Expo Concludes, Andrew Francis
In the Rick of Time: Season 6 Launces Off My 2022 School Year, Grace No
NEWS
Almost Anything Goes, Glow Edition, Yoel Kim & Editors
Lead Levels in Benton Harbor, Abigail Kim
Students React to Queen Elizabeth\u27s Passing, Andrew Francis
IDEAS
iOS 16 and the new iPhone: Bop or Flop?, Rachel Ingram-Clay
Meghan Markle and the British Media, Terika Williams
The Little Mermaid and the Importance of Representation, Genevieve Prouty
PULSE
Change Day 2022, Elizabeth Dovich
Clubs & Organizations Ice Cream Fair, Charisse Lapuebla
Scientists Engaging Beyond Classroom & Lab, Desmond Hartwell Murray
Divine Direction: Week of Prayer at Andrews University, Melissa Moore
LAST WORD
Thoughts at 30,000 Feet, Alannah Tjhatrahttps://digitalcommons.andrews.edu/sm-107/1001/thumbnail.jp
Recommended from our members
Livestock Protection Tools for California Ranchers
Conflicts between livestock and predators are perhaps inevitable, especially on extensively managed rangelands This publication helps producers evaluate livestock lethal and non-lethal protection tools that may fit their site-specific needs
Can I Have A Word? Social Worker Interaction and Sense-Making
This paper explores the ways in which practitioners in children and family social work teams make sense of information in their work. By examining observations and recordings from an ethnographic study, the paper focuses on how informal discussions within the office space inform and affect social workers' analysis (or sense-making). Three elements of sense-making activity are illustrated with vignettes and extracts from field notes: methodical doubt, proximity/reflexivity and security. These three distinct features of practice are then discussed and the significance of the findings considered in relation to contemporary practice. The paper highlights the importance of informal interaction and discussion in the social work office as part of the process of social workers' sense-making. It indicates that feelings of trust and security may be linked to intellectual curiosity and an ability to work with uncertainty in sense-making. Ethnography can provide a means of illuminating this complex and inaccessible element of practice and the findings add to the body of knowledge. Practitioners and organisations may wish to reflect on the findings and consider how they contribute to, and are affected by, such cultures and practices
Manipulating the monolayer : responsive and reversible control of colloidal inorganic nanoparticle properties
Funding: EPSRC EP/K016342/1; Leverhulme Trust: RPG-2015-042For a wide range of nanomaterials, surface-bound molecules play a central role in defining properties, and are key to integration with other components â be they molecules, surfaces, or other nanoparticles. Predictable and general methods for manipulating the surface monolayer are therefore crucial to exploiting this new region of chemical space. This review highlights limitations of the few established methods for controlling nanoparticle-bound molecular functionality, then focuses on emerging new strategies. In particular, approaches that can achieve stimuli-responsive and reversible modification of surface-bound molecules in colloidal solution are examined, with an emphasis on using these methods to control nanoparticle properties such as solvent compatibility, catalytic activity and cytotoxicity. Finally, the outstanding challenges and future potential for precisely controlled nanoparticle bound monolayers are discussed.Publisher PDFPeer reviewe
Polypyrrole-Fe2O3 nanohybrid materials for electrochemical storage
We report on the synthesis and electrochemical characterization of nanohybrid polypyrrole (PPy) (PPy/Fe2O3) materials for electrochemical storage applications. We have shown that the incorporation of nanoparticles inside the PPy notably increases the charge storage capability in comparison to the âpureâ conducting polymer. Incorporation of large anions, i.e., paratoluenesulfonate, allows a further improvement in the capacity. These charge storage modifications have been attributed to the morphology of the composite in which the particle sizes and the specific surface area are modified with the incorporation of nanoparticles. High capacity and stability have been obtained in PC/NEt4BF4 (at 20 mV/s), i.e., 47 mAh/g, with only a 3% charge loss after one thousand cyles. The kinetics of chargeâdischarge is also improved by the hybrid nanocomposite morphology modifications, which increase the rate of insertionâexpulsion of counter anions in the bulk of the film. A room temperature ionic liquid such as imidazolium trifluoromethanesulfonimide seems to be a promising electrolyte because it further increases the capacity up to 53 mAh/g with a high stability during chargeâdischarge processes
The surgical management of hidradenitis suppurativa in the United Kingdom: a national survey of care pathways informing the THESEUS study
Background
The evidence-base underpinning treatment efficacy and effectiveness for hidradenitis suppurativa (HS) is limited, as has been highlighted in the wide-ranging research priorities established by a James Lind Alliance priority-setting partnership (PSP). Understanding the landscape of surgical practice is a key step towards tackling undesired variation in care and resolving treatment uncertainties. This survey of current surgical practice aimed to describe care pathways involving surgeons for the management of HS and surgical approaches to management.
Methods
In the development of the prospective cohort Treatment of Hidradenitis Suppurativa Evaluation Study (THESEUS), a bespoke electronic surgeon survey was conducted to describe variation in care pathways and surgical preferences in the management of HS. This was disseminated to a pre-defined denominator list of surgeons using local collaborators through the reconstructive surgery trials network (RSTN).
Results
Key results were small numbers of surgeons working in formal multidisciplinary teams (MDTs) (8/198, 4%), heterogeneity of first-line intervention, low rates of guideline endorsed treatments (laser and deroofing in particular), variation in wound closure methods and follow-up length, and that over half of respondents do not use well-validated outcome instruments to determine treatment success/failure (110/198, 56%).
Conclusions
This survey demonstrated variation in care, which is likely to be undesirable. Surgeons treating HS patients might consider developing MDTs or referring patients to those with an interest in HS and considering routine outcome measurement. Such steps might reduce variation, increase standardisation of care and improve access to specific treatments
- âŠ