Magnetization of ferrofluids with dipolar interactions - a Born--Mayer expansion

For ferrofluids that are described by a system of hard spheres interacting via dipolar forces we evaluate the magnetization as a function of the internal magnetic field with a Born--Mayer technique and an expansion in the dipolar coupling strength. Two different approximations are presented for the magnetization considering different contributions to a series expansion in terms of the volume fraction of the particles and the dipolar coupling strength.Comment: 19 pages, 11 figures submitted to PR

Strategies Utilized to Prevent and Control SARS-CoV-2 Transmission in Two Congregate, Psychiatric Healthcare Settings During the Pandemic

BACKGROUND: The COVID-19 pandemic has had a substantial effect on the delivery of psychiatric healthcare. Inpatient psychiatric healthcare facilities have experienced outbreaks of COVID-19, making these areas particularly vulnerable. METHODS: Our facility used a multidisciplinary approach to implement enhanced infection prevention and control (IPC) interventions in our psychiatric healthcare areas. RESULTS: In a sixteen-month period during the COVID-19 pandemic, our two facilities provided >29,000 patient days of care to 1,807 patients and identified only forty-seven COVID-19 positive psychiatric health inpatients (47/1,807, or 2.6%). We identified the majority of these cases by testing all patients at admission, preventing subsequent outbreaks. Twenty-one psychiatric healthcare personnel were identified as COVID+ during the same period, with 90% linked to an exposure other than a known positive case at work. DISCUSSION: The IPC interventions we implemented provided multiple layers of safety for our patients and our staff. Ultimately, this resulted in low SARS-CoV-2 infection rates within our facilities. CONCLUSIONS: Psychiatric healthcare facilities are uniquely vulnerable to COVID-19 outbreaks because they are congregate units that promote therapeutic interactions in shared spaces. IPC interventions used in acute medical care settings can also work effectively in psychiatric healthcare, but often require modifications to ensure staff and patient safety

Mortality and pulmonary complications in patients undergoing surgery with perioperative SARS-CoV-2 infection: an international cohort study

Background: The impact of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) on postoperative recovery needs to be understood to inform clinical decision making during and after the COVID-19 pandemic. This study reports 30-day mortality and pulmonary complication rates in patients with perioperative SARS-CoV-2 infection. Methods: This international, multicentre, cohort study at 235 hospitals in 24 countries included all patients undergoing surgery who had SARS-CoV-2 infection confirmed within 7 days before or 30 days after surgery. The primary outcome measure was 30-day postoperative mortality and was assessed in all enrolled patients. The main secondary outcome measure was pulmonary complications, defined as pneumonia, acute respiratory distress syndrome, or unexpected postoperative ventilation. Findings: This analysis includes 1128 patients who had surgery between Jan 1 and March 31, 2020, of whom 835 (74·0%) had emergency surgery and 280 (24·8%) had elective surgery. SARS-CoV-2 infection was confirmed preoperatively in 294 (26·1%) patients. 30-day mortality was 23·8% (268 of 1128). Pulmonary complications occurred in 577 (51·2%) of 1128 patients; 30-day mortality in these patients was 38·0% (219 of 577), accounting for 81·7% (219 of 268) of all deaths. In adjusted analyses, 30-day mortality was associated with male sex (odds ratio 1·75 [95% CI 1·28–2·40], p\textless0·0001), age 70 years or older versus younger than 70 years (2·30 [1·65–3·22], p\textless0·0001), American Society of Anesthesiologists grades 3–5 versus grades 1–2 (2·35 [1·57–3·53], p\textless0·0001), malignant versus benign or obstetric diagnosis (1·55 [1·01–2·39], p=0·046), emergency versus elective surgery (1·67 [1·06–2·63], p=0·026), and major versus minor surgery (1·52 [1·01–2·31], p=0·047). Interpretation: Postoperative pulmonary complications occur in half of patients with perioperative SARS-CoV-2 infection and are associated with high mortality. Thresholds for surgery during the COVID-19 pandemic should be higher than during normal practice, particularly in men aged 70 years and older. Consideration should be given for postponing non-urgent procedures and promoting non-operative treatment to delay or avoid the need for surgery. Funding: National Institute for Health Research (NIHR), Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, NIHR Academy, Sarcoma UK, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research

Modern women or tree-hugging hippies? A Foucauldian discourse analysis of the New Zealand media's representation of waterbirth.

This study has identified the discourses surrounding water birth and analyses how these discourses are utilised by the media in New Zealand to represent water birth. The philosophical approach that underpins the study is that of philosopher Michel Foucault and his theory on discourse, power and the subject. His framework is used in a discourse analysis to reveal three main discourses: the scientific medical discourse, the natural birth discourse and the dive reflex discourse. Data used for this study consisted of 30 newspaper articles containing the word 'water birth' collected over a five-year period (2000-2005) from New Zealand's eight main broadsheet newspapers. Analysis was a two-part process: Foucauldian discourse analysis and a media discourse analysis (Fairclough, 1995b).Firstly, the discourse analysis showed the subject and the power positions each discourse offered women for positioning themselves in that discourse. The literature and texts revealed Foucault's theory on power relations and resultant subjectivity within institutions and how waterbirth within institutions is disciplined, surveilled, excluded and circulated. The second part of the analysis revealed how the media chooses to deploy the three identified discourses that represent waterbirth in New Zealand. This textual analysis followed the framework of Fairclough's (1995b) media discourse analysis, showing media strategies that are used to promote the discourse deemed to be ideologically significant by the media outlet. Textual analysis identified that the scientific medical discourse contests waterbirth as an unsafe, unproven practice that puts babies' lives at risk. This discourse categorises women who choose waterbirth as unsafe, irrational, alternative, tree-hugging hippies who favour perceived benefits of waterbirth for themselves above the safety of their baby. The natural birth discourse contests that waterbirth is a safe practice that has encountered few problems since its emergence as a validated birthing practice in the late 1980s. It promotes waterbirth as having multiple benefits for both mother and baby and as a way of enhancing the physiological process of birth through non-intervention. The dive reflex discourse underpins the issue of babies drowning when born into water. This discourse details a reflex that suppresses the normal breathing mechanisms in neonates at birth. Literature debates its existence and troubles the overall trustworthiness of such a reflex to prevent a baby drowning when born into water. It is this discourse that sways people's views and positioning on the overall discourse of waterbirth

Youth cannabis use in Canada post-legalization: service providers’ perceptions, practices, and recommendations

Abstract Background In 2018, Canada legalized recreational cannabis use with the purpose of protecting youth and restricting access. However, concerns have been raised that this objective has not been met as rates of cannabis use among youth aged 16–24 have not declined. Youth cannabis use is associated with various adverse effects including psychosis, anxiety, depression, suicidality, respiratory distress, cannabinoid hyperemesis syndrome, and intoxications. Service providers play a crucial role in addressing youth cannabis use. This study aimed to understand Ontario service providers’ perceptions, practices, and recommendations on youth cannabis use. Methods This mixed method study included a survey and two focus groups. The survey was distributed to mental health service providers serving youth aged 16–24 across Ontario who were given the option to participate in a focus group. The survey included closed and open-ended questions regarding perceptions, practices, and recommendations, while the focus groups explored these categories in greater depth. Descriptive statistics were used to analyze close-ended questions and interpretative content analysis was applied for open-ended questions. Focus group data were analyzed using thematic analysis. Results The survey was completed by 160 service providers and 12 participated in two focus groups. Regarding perceptions, 60% of survey participants agreed with legalization, 26% had a strong understanding of medical versus recreational cannabis, 84% believed that cannabis has physical and mental health risks, and 49% perceived stigmatization. Less than half of the survey participants reported screening or assessing cannabis use, 16% stated they are highly familiar with treating cannabis use, and 67% reported that they rarely work with families. Subthemes identified in the focus groups under perceptions included normalization and stigmatization, harms for youth, and stigma, racism, and discrimination. Subthemes under practice included cannabis not being the primary focus, challenges with screening, assessment, and intervention, and referral to specialized services. Both the survey and focus group participants recommended increasing public education, enhancing service provider training, improving regulation and policies, reducing stigma and minimization, improving service access, and providing more culturally responsive services. Conclusion Youth cannabis use in Canada remains a significant public health concern, necessitating a more comprehensive plan to protect Ontario youth and reduce associated harms

Larissa Sansour and the Palestinian Ruins of the Future

This article considers how the work of artist Larissa Sansour in A Space Exodus (2009), Nation Estate (2012) and In the Future They Ate from the Finest Porcelain (2016) represents a compelling series of oblique engagements with Palestine’s historical predicament through both comic and poignant deployment of science fiction’s enduring fascination with historicity and the ruins of the future. In tracing how her films situate their narratives in relation to famous examples of science fiction as well as the politics of archaeology and architecture, I am seeking to place Sansour’s complex play with temporality at the heart of both a key tradition in science fiction and the ongoing stasis that continues to beset Palestinians today

Interaction of Diverse Voltage Sensor Homologs with Lipid Bilayers Revealed by Self-Assembly Simulations

Voltage sensors (VS) domains couple the activation of ion channels/enzymes to changes in membrane voltage. We used molecular dynamics simulations to examine interactions with lipids of several VS homologs. VSs in intact channels in the activated state are exposed to phospholipids, leading to a characteristic local distortion of the lipid bilayer which decreases its thickness by ∼10 Å. This effect is mediated by a conserved hydrophilic stretch in the S4–S5 segment linking the VS and the pore domains, and may favor gating charges crossing the membrane. In cationic lipid bilayers lacking phosphate groups, VSs form fewer contacts with lipid headgroups. The S3–S4 paddle motifs show persistent interactions of individual lipid molecules, influenced by the hairpin loop. In conclusion, our results suggest common interactions with phospholipids for various VS homologs, providing insights into the molecular basis of their stabilization in the membrane and how they are altered by lipid modification