A first test of the hypothesis of biogenic magnetite-based heterogeneous ice-crystal nucleation in cryopreservation

An outstanding biophysical puzzle is focused on the apparent ability of weak, extremely low-frequency oscillating magnetic fields to enhance cryopreservation of many biological tissues. A recent theory holds that these weak magnetic fields could be inhibiting ice-crystal nucleation on the nanocrystals of biological magnetite (Fe_3O_4, an inverse cubic spinel) that are present in many plant and animal tissues by causing them to oscillate. In this theory, magnetically-induced mechanical oscillations disrupt the ability of water molecules to nucleate on the surface of the magnetite nanocrystals. However, the ability of the magnetite crystal lattice to serve as a template for heterogeneous ice crystal nucleation is as yet unknown, particularly for particles in the 10–100 nm size range. Here we report that the addition of trace-amounts of finely-dispersed magnetite into ultrapure water samples reduces strongly the incidence of supercooling, as measured in experiments conducted using a controlled freezing apparatus with multiple thermocouples. SQUID magnetometry was used to quantify nanogram levels of magnetite in the water samples. We also report a relationship between the volume change of ice, and the degree of supercooling, that may indicate lower degassing during the crystallization of supercooled water. In addition to supporting the role of ice-crystal nucleation by biogenic magnetite in many tissues, magnetite nanocrystals could provide inexpensive, non-toxic, and non-pathogenic ice nucleating agents needed in a variety of industrial processes, as well as influencing the dynamics of ice crystal nucleation in many natural environments

Magnetic control of heterogeneous ice nucleation with nanophase magnetite: Biophysical and agricultural implications

In supercooled water, ice nucleation is a stochastic process that requires ∼250–300 molecules to transiently achieve structural ordering before an embryonic seed crystal can nucleate. This happens most easily on crystalline surfaces, in a process termed heterogeneous nucleation; without such surfaces, water droplets will supercool to below −30 °C before eventually freezing homogeneously. A variety of fundamental processes depends on heterogeneous ice nucleation, ranging from desert-blown dust inducing precipitation in clouds to frost resistance in plants. Recent experiments have shown that crystals of nanophase magnetite (Fe_3O_4) are powerful nucleation sites for this heterogeneous crystallization of ice, comparable to other materials like silver iodide and some cryobacterial peptides. In natural materials containing magnetite, its ferromagnetism offers the possibility that magneto-mechanical motion induced by external oscillating magnetic fields could act to disrupt the water–crystal interface, inhibiting the heterogeneous nucleation process in subfreezing water and promoting supercooling. For this to act, the magneto-mechanical rotation of the particles should be higher than the magnitude of Brownian motions. We report here that 10-Hz precessing magnetic fields, at strengths of 1 mT and above, on ∼50-nm magnetite crystals dispersed in ultrapure water, meet these criteria and do indeed produce highly significant supercooling. Using these rotating magnetic fields, we were able to elicit supercooling in two representative plant and animal tissues (celery and bovine muscle), both of which have detectable, natural levels of ferromagnetic material. Tailoring magnetic oscillations for the magnetite particle size distribution in different tissues could maximize this supercooling effect

Restrictive ID policies: implications for health equity

We wish to thank Synod Community Services for their critical work to develop, support, and implement a local government-issued ID in Washtenaw County, MI. We also thank Yousef Rabhi of the Michigan House of Representatives and Janelle Fa'aola of the Washtenaw ID Task Force, Lawrence Kestenbaum of the Washtenaw County Clerk's Office, Sherriff Jerry Clayton of the Washtenaw County Sherriff's Office, and the Washtenaw ID Task Force for their tireless commitment to developing and supporting the successful implementation of the Washtenaw ID. Additionally, we thank Vicenta Vargas and Skye Hillier for their contributions to the Washtenaw ID evaluation. We thank the Curtis Center for Research and Evaluation at the University of Michigan School of Social Work, the National Center for Institutional Diversity at the University of Michigan, and the University of California-Irvine Department of Chicano/Latino Studies and Program in Public Health for their support of the Washtenaw ID community-academic research partnership. Finally, we thank the reviewers for their helpful comments on earlier drafts of this manuscript. (Curtis Center for Research and Evaluation at the University of Michigan School of Social Work; National Center for Institutional Diversity at the University of Michigan; University of California-Irvine Department of Chicano/Latino Studies; Program in Public Health)https://link.springer.com/content/pdf/10.1007/s10903-017-0579-3.pdfPublished versio

Magnetic control of heterogeneous ice nucleation with nanophase magnetite: Biophysical and agricultural implications

In supercooled water, ice nucleation is a stochastic process that requires ∼250–300 molecules to transiently achieve structural ordering before an embryonic seed crystal can nucleate. This happens most easily on crystalline surfaces, in a process termed heterogeneous nucleation; without such surfaces, water droplets will supercool to below −30 °C before eventually freezing homogeneously. A variety of fundamental processes depends on heterogeneous ice nucleation, ranging from desert-blown dust inducing precipitation in clouds to frost resistance in plants. Recent experiments have shown that crystals of nanophase magnetite (Fe_3O_4) are powerful nucleation sites for this heterogeneous crystallization of ice, comparable to other materials like silver iodide and some cryobacterial peptides. In natural materials containing magnetite, its ferromagnetism offers the possibility that magneto-mechanical motion induced by external oscillating magnetic fields could act to disrupt the water–crystal interface, inhibiting the heterogeneous nucleation process in subfreezing water and promoting supercooling. For this to act, the magneto-mechanical rotation of the particles should be higher than the magnitude of Brownian motions. We report here that 10-Hz precessing magnetic fields, at strengths of 1 mT and above, on ∼50-nm magnetite crystals dispersed in ultrapure water, meet these criteria and do indeed produce highly significant supercooling. Using these rotating magnetic fields, we were able to elicit supercooling in two representative plant and animal tissues (celery and bovine muscle), both of which have detectable, natural levels of ferromagnetic material. Tailoring magnetic oscillations for the magnetite particle size distribution in different tissues could maximize this supercooling effect

Minor Keywords of Political Theory: Migration as a Critical Standpoint. A collaborative project of collective writing

Coordinated and Edited by: N De Genova, M Tazzioli Co-Authored by: Claudia Aradau, Brenna Bhandar, Manuela Bojadzijev, Josue David Cisneros, N De Genova, Julia Eckert, Elena Fontanari, Tanya Golash-Boza, Jef Huysmans, Shahram Khosravi, Clara Lecadet, Patrisia Macías-Rojas, Federica Mazzara, Anne McNevin, Peter Nyers, Stephan Scheel, Nandita Sharma, Maurice Stierl, Vicki Squire, M Tazzioli, Huub van Baar and William Walter

Turning the Tables: Media Constructions of British Asians from Victims to Criminals, 1962 to 2011

Book synopsis: Media, Crime and Racism draws together contributions from scholars at the leading edge of their field across three continents to present contemporary and longstanding debates exploring the roles played by media and the state in racialising crime and criminalising racialised minorities. Comprised of empirically rich accounts and theoretically informed analysis, this dynamic text offers readers a critical and in-depth examination of contemporary social and criminal justice issues as they pertain to racialised minorities and the media. Chapters demonstrate the myriad ways in which racialised ‘others’ experience demonisation, exclusion, racist abuse and violence licensed – and often induced – by the state and the media. Together, they also offer original and nuanced analysis of how these processes can be experienced differently dependent on geography, political context and local resistance. This collection critically reflects on a number of globally significant topics including the vilification of Muslim minorities, the portrayal of the refugee ‘crisis’ and the representations and resistance of Indigenous and Black communities. This volume demonstrates that processes of racialisation and criminalisation in media and the state cannot be understood without reference to how they are underscored and inflected by gender and power. Above all, the contributors to this volume demonstrate the resistance of racialised minorities in localised contexts across the globe: against racialisation and criminalisation and in pursuit of racial justice

Laparoscopic correction of perforated peptic ulcer: first choice? A review of literature

Background Perforated peptic ulcer (PPU), despite antiulcer medication and Helicobacter eradication, is still the most common indication for emergency gastric surgery associated with high morbidity and mortality. Outcome might be improved by performing this procedure laparoscopically, but there is no consensus on whether the benefits of laparoscopic closure of perforated peptic ulcer outweigh the disadvantages such as prolonged surgery time and greater expense. Methods An electronic literature search was done by using PubMed and EMBASE databases. Relevant papers written between January 1989 and May 2009 were selected and scored according to Effective Public Health Practice Project guidelines. Results Data were extracted from 56 papers, as summarized in Tables 1-7. The overall conversion rate for laparoscopic correction of perforated peptic ulcer was 12.4%, with main reason for conversion being the diameter of perforation. Patients presenting with PPU were predominantly men (79%), with an average age of 48 years. Onethird had a history of peptic ulcer disease, and one-fifth took nonsteroidal anti-inflammatory drugs (NSAIDs). Only 7% presented with shock at admission. There seems to be no consensus on the perfect setup for surgery and/or operating technique. In the laparoscopic groups, operating time was significant longer and incidence of recurrent leakage at the repair site was higher. Nonetheless there was significant less postoperative pain, lower morbidity, less mortality, and shorter hospital stay. Conclusion There are good arguments that laparoscopic correction of PPU should be first treatment of choice. A Boey score of 3, age over 70 years, and symptoms persisting longer than 24 h are associated with higher morbidity and mortality and should be considered contraindications for laparoscopic intervention

Slavery and the Revival of Anti-slavery Activism

This chapter sets out the volumes critical approach to the dominant discourse on modern slavery and its impulse to question the assumptions and the politics behind that discourse. It explores the limits of the modern slavery rhetoric for understanding the complicated logics of agency, freedom and belonging, and of past, present and future, for those who are constituted as slaves. Document type: Part of book or chapter of boo

Displacement and Resettlement: Understanding the Role of Climate Change in Contemporary Migration

How do we understand displacement and resettlement in the context of climate change? This chapter outlines challenges and debates in the literature connecting climate change to the growing global flow of people. We begin with an outline of the literature on environmental migration, specifically the definitions, measurements, and forms of environmental migration. The discussion then moves to challenges in the reception of migrants, treating the current scholarship on migrant resettlement. We detail a selection of cases in which the environment plays a role in the displacement of a population, including sea level rise in Pacific Island States, cyclonic storms in Bangladesh, and desertification in West Africa, as well as the role of deforestation in South America’s Southern Cone as a driver of both climate change and migration. We outline examples of each, highlighting the complex set of losses and damages incurred by populations in each case

Management of intra-abdominal infections : recommendations by the WSES 2016 consensus conference

This paper reports on the consensus conference on the management of intra-abdominal infections (IAIs) which was held on July 23, 2016, in Dublin, Ireland, as a part of the annual World Society of Emergency Surgery (WSES) meeting. This document covers all aspects of the management of IAIs. The Grading of Recommendations Assessment, Development and Evaluation recommendation is used, and this document represents the executive summary of the consensus conference findings.Peer reviewe