bluuebunny/crossref_metadata_2025 huggingface dataset:
561 Impact of Support Group for Teen Burn Survivors
Authors: Castro Alexis , Muro Marissa , Dominic William , Kopari Nicole M
Published: March 2020

Introduction

The recovery of a burn survivor continues long after the physical wounds are healed. Peer support groups offer survivors an opportunity for psychosocial recovery, particularly in the areas of self-acceptance, changes in perspective, and identity. Multiple published studies have found group support to be beneficial. We identified a need to provide a separate teen burn survivor support group to optimize engagement and to address specific age appropriate discussions.

Methods

The support group included female burn survivors 14–17 years of age. The group sessions were facilitated by a child life specialist and a burn nurse. Meetings were held on the same evenings as adult support groups to allow parents of the teen survivors to attend the adult meeting. During the first meeting, participants were given the opportunity to share topics they would like to discuss, and these were incorporated into the curriculum. Topics specific to teens included identity issues, body image, peer relationships, and what it means to be a burn survivor advocate. Additional outings have been incorporated such as family dinners and movie nights. After 15 months, participants were surveyed on their overall experience.

Results

The group was established in February 2018 and has had a steady participation of teen burn survivors. All teen burn survivors completed the participation survey. All teens strongly agreed their experience was positive, felt more connected to the other participants through the group activities, felt accepted by the other group members, and would recommend the teen support group to other teen burn survivors. Teens rated positive results for learning about themselves as a burn survivor, changing their perspective on their recovery, and the importance of participating in a support group.

Conclusions

Teen burn survivor support group has been shown to be a sustainable method to support these burn survivors and provide them with an opportunity for psychosocial recovery.

Applicability of Research to Practice

By sharing our experience with a teen burn survivor support group, we hope to inspire other burn centers in developing ways that their facility can meet the needs of burn survivors.
706 Frostbite and Drugs of Abuse: Friend or Foe?
Authors: Wagner Anne L Lambert , Dyamenahalli Kiran U , Smith Tyler M , Duffy Patrick , Kovacs Elizabeth J , Wiktor Arek J
Published: March 2020

Introduction

In the literature, the incidence of alcohol and/or drug use among burn patients ranges from 16.4%-69%. Burn patients with positive toxicology (tox) screens on admission are known to have increased rates of morbidity and mortality. To date little has been published on the effects of positive alcohol and/or drug screens on outcomes in the frostbite population. The objective of this study was to investigate the incidence of drugs and alcohol use in admitted patients with severe frostbite and their association with clinical outcomes.

Methods

A retrospective cohort study was conducted on 141 frostbite patients admitted to a verified burn center from November 2015 to March 2019. Patients were identified using our burn registry and relevant data was obtained through chart reviews. The primary comparison was between patients with and without a positive tox screen on admission, assessing administration of thrombolytics (tPA) and rates of amputation. Contingency analysis for categorical variables was performed using Fisher’s exact test, while the Mann-Whitney U test was used for continuous variables, reporting, two-tailed p values.

Results

Tox screens were positive in 77.3% (109) of frostbite patients: 52.5% (74) for marijuana and 56.7% (80) for alcohol. Homelessness accounted for 50.4% (71) and 63.1% (89) were tobacco users. Compared to patients with negative tox screens, significantly higher rates of amputation were found in those using marijuana (p=0.016), other drugs of abuse (p=0.008) and tobacco (p=0.0093). Significantly higher limb salvage rates were found in patients presenting with a negative tox screen (p=0.0077). Only tobacco users had a significantly greater length of stay (p=0.02). 36.2% (51) of the patients received tPA with no difference in administration rates between positive and negative tox screened patients. Patients receiving tPA had significantly lower rates of amputation (p=0.02). 51.8% (73) of admitted patients were homeless, with 83.6% (61) testing tox positive. Both increased hospital length of stay (p=< 0.001) and amputation rates (p=0.0004) were observed in the homeless frostbite population.

Conclusions

Drugs, alcohol and homelessness significantly impact clinical outcomes in frostbite patients. Homelessness, marijuana, tobacco and other drugs of abuse are associated with significantly higher rates of amputation despite receiving tPA at the same rate. Administration of tPA is significant in lowering amputation rates.

Applicability of Research to Practice

The association between drugs of abuse, homelessness and frostbite highlight the need for increased preventative efforts especially in the homeless population.
714 IL-6 and Soluble IL-6 Receptor – Two Sides of the Same Coin
Authors: Rehou Sarah , Abdullahi Abdikarim , Jeschke Marc G
Published: March 2020

Introduction

Interleukin (IL)-6 is a multifunctional cytokine that has both a pro- and anti-inflammatory role. In many studies, IL-6 has been shown to increase rapidly after burn injury and is associated with poor outcomes. IL-6 can signal via its soluble IL-6 Receptor (sIL-6R) and is referred to as trans-signaling, which is regarded as the pro-inflammatory pathway. The role of sIL-6R post-burn injury has not yet been explored. We hypothesized that patients with a lower ratio of IL-6 to sIL-6R would have worse outcomes.

Methods

Patients admitted to our burn centre within 7 days of injury were included in this study. Patients were divided into two groups based on IL-6 and sIL-6R levels measured within the first 30 days post-burn injury. Patients were in the high ratio group if their IL-6:sIL-6R ratio was ≥ 0.185. Clinical outcomes included organ biomarkers, morbidities, and hospital length of stay. Groups were compared using Student’s t-test, Mann-Whitney U, and Fisher’s exact test as appropriate; a P value of < 0.05 was considered statistically significant.

Results

We studied 104 patients, mean age 51 ± 18 years and 24 ± 17% total body surface area (TBSA) burn. There were 49 patients categorized with a low IL-6:sIL-6R ratio and 55 patients with a high IL-6:sIL-6R ratio. Patients in the high IL-6:sIL-6R ratio group had a significantly greater TBSA burn and a significantly greater proportion of patients with inhalation injury (p< 0.05). Levels of sIL-6R were not significantly different among the low and high group (770 ± 264 pg/mL vs. 798 ± 268 pg/mL respectively; p=0.601). However, levels of IL-6 were significantly higher in patients with a high IL-6:sIL-6R ratio (37 IQR 19–97 pg/mL vs. 567 IQR 273–916 pg/mL; p< 0.0001). Mortality was significantly greater in the high IL-6:sIL-6R ratio group (2% vs. 27%; p< 0.001).

Conclusions

Interestingly, patients with a higher ratio of IL-6:sIL-6R had significantly greater mortality. Using sIL-6R as a marker for the proinflammatory immune response, we expected patients with a lower IL-6:sIL-6R ratio to have poor outcomes which are typically associated with a hyperinflammatory or exaggerated immune response. However, the absolute value of sIL-6R did not differ. This suggests that classic signaling of IL-6 via its membrane bound receptor, with an anti-inflammatory function, is an important factor.

Applicability of Research to Practice

The opposing pro- and anti-inflammatory function of IL-6 through trans- and classic signaling is contingent on the ratios expressed. The demonstrated increase in classic signaling highlights the importance of measuring both IL-6 and sIL-6R in future studies. Additionally, it lays the foundation for potential precision medicine approaches to selectively block specific signaling pathways.
760 Patients with Pre-existing Mental Illness Who Developed Stevens-Johnson Syndrome and Toxic Epidermal Necrolysis: Lessons Learned at a Large Tertiary Burn Center and the Importance of Accurately Diagnosing Psychiatric Disorders
Authors: Laughon Sarah L , Duplisea Michael , Ziemer Carolyn , Chrisco Lori , Williams Felicia N , Jones Samuel W , Cairns Bruce , Nizamani Rabia , Gala Gary J
Published: March 2020

Introduction

In recent years, burn centers are managing more patients with exfoliative skin disorders including Stevens-Johnson Syndrome (SJS), Toxic Epidermal Necrolysis (TEN), and SJS/TEN overlap. While it is well known that burn patients have higher rates of co-morbid psychiatric disorders than the general population, the incidence of pre-existing psychiatric disorders among patients who develop SJS, SJS/TEN overlap, and TEN is unknown. This study aimed to characterize a cohort of patients with pre-existing psychiatric disorders admitted to a tertiary burn center for treatment of SJS, SJS/TEN overlap, and TEN with specific focus on those who received the offending agent for a psychiatric indication.

Methods

A retrospective descriptive case series using an institutional burn center registry was performed. All patients admitted to a single verified burn center between January 1, 2009 and December 31, 2018 with biopsy-proven SJS, SJS/TEN overlap, or TEN and the presence of a co-morbid psychiatric disorder were identified. Demographic, hospital, and clinical information were extracted from the burn registry and verified through review of the electronic medical record.

Results

Among 168 patients with biopsy-proven SJS, SJS/TEN overlap, or TEN, 18% (30/168) had a pre-existing psychiatric disorder, with the offending agent being prescribed for a psychiatric indication in 30% (10/30) of patients. Lamotrigine was the offending agent in 80% of cases and prescribed 100% of the time for a psychiatric indication. Of those who received lamotrigine, patients were 100% female, 63% black, and had an average age of 38 years. The mean length of stay was 24 days and 88% received a psychiatric consultation. While 75% of patients were started on lamotrigine for a diagnosis of bipolar disorder, none of these patients met criteria for bipolar disorder.

Conclusions

Pre-existing psychiatric comorbidity is less common among patients that develop SJS, SJS/TEN overlap, and TEN than in burn-injured patients. For patients with pre-existing psychiatric disorders who develop these potentially fatal skin diseases from an offending agent that was prescribed for a psychiatric indication, early involvement of psychiatry colleagues is recommended to ensure proper psychiatric diagnosis and management moving forward.

Applicability of Research to Practice

This study highlights the importance of accurate assessment for and diagnosis of bipolar disorder prior to determining treatment approach. For the burn surgeon treating these patients, early involvement of psychiatric consultants is recommended and extremely important.
778 Association of Demographic and Burn-related Factors to PTSD Pre-screen Survey Results Among Burn Patients
Authors: Spadafore Sophia , Meyer Paul , Spadafore Philomene , Bhattarai Bikash , Foster Kevin N
Published: March 2020

Introduction

A burn injury can be a traumatic experience and many patients suffer physical, social, and psychological consequences. Stress disorders, including posttraumatic stress disorder (PTSD), have been reported to occur after burn injury in 18%-33% of cases, but knowledge about the predictors of PTSD in burn patients is still lacking. The objective of our study is to evaluate the demographic and burn-related factors in these patients associated with screening positive or negative to be at high risk for PTSD.

Methods

All patients who met the inclusion/exclusion criteria were administered the 4-item Primary Care Post-Traumatic Stress Disorder screen (PC-PTSD) survey, and subsequently their charts were reviewed. High risk of PTSD was defined as a “yes” answer to three or more survey questions. Variables collected on each subject included gender, date of birth, age at time of burn, date of burn, race, ethnicity, insurance category, TBSA, burn location, and whether surgery was required for the burn. Wilcoxon rank sum test with continuity correction was used to compare patients with a positive screen to those without one. Fisher’s Exact Test for Count Data was used to analyze the associations of gender and need for surgery to the positive or negative screening test results.

Results

Among the 121 patients who met inclusion criteria and had burn mechanism documented, 15 were excluded due to missing information or unclear burn mechanism. Among the 121 patients, 55 (45.5%) screened positive and 66 screened negative. The mean (median) TBSA percentage for the patients screening negative was 4.79 (3.0) and 11.35 (4.5) for the patients who screened positive (P=0.02). 51.8% of females had a positive screening test compared to 40% males (Fisher’s exact P=0.206). Of the patients requiring surgery, 49% of the patients had a positive screening test, compared to only 40% who did not require surgery (Fisher’s exact P = 0.365).

Conclusions

In analyzing these survey results it was clear that burn patients with a higher TBSA are significantly more likely to develop PTSD than those will a smaller TBSA, with the mean TBSA for patients developing PTSD being 11.35%. Probable association was found between developing PTSD and female gender. The need for surgery was also correlated with a slight increase in PTSD, though this was not statistically significant. More research is necessary to determine other factors in burn patients that may be associated with PTSD.

Applicability of Research to Practice

All patients with burns should be screened for PTSD, but particularly those with greater than 11% TBSA. Resources should be given to burn patients at discharge to follow up on the results of their PTSD screening.
785 Beyond the Burn Center: Creating Nursing Clinical Guidelines for Pediatric Burn Patients That Present to Community Emergency Departments
Authors: Nickerson Jillian , Decerbo Paul C
Published: March 2020

Introduction

The goal of this project was to improve the initial care of pediatric burn patients that present to community hospital emergency departments before transfer to a burn center. The pediatric burn center received a transfer of a burn patient from a community emergency department that showed there was room for improvement on the initial care before transfer to the burn center.

Methods

This was a quality improvement project between the pediatric emergency department in conjunction with an outside community hospital emergency department to develop clinical guidelines using the burn centers handbook as well as the most recent ABA and ABLS guidelines to develop standards of care for a pediatric burn patient. These clinical guidelines would serve as recommendations in regards of calculating the total body surface area (TBSA) effected, the calculations of required fluid resuscitation including the addition of maintenance fluids, pain control recommendations, as well as when to transfer to a burn center.

Results

This project resulted in a multi-site collaborative effort which produced a thorough and easy to follow algorithm which takes the care provider through each step of the initial resuscitation of a pediatric burn patient. The algorithm initiates with the primary survey and moves through to the secondary survey with individual color coded categories for each thickness of burn. These categories run through the treatment recommendations while adhering to burn center’s treatment recommendations. This all terminates into a disposition determination for both minor and major burns. The major burn category runs through the transport criteria set forth by The American Burn Association.

Conclusions

Phase one of this project concluded with a collaborative effort between a Community Hospital ED and a Level 1 Burn Center ED. This coordination established an evidence based practice guideline allowing two completely separate departments within the state to provide synergistic and coordinated care to one of the most vulnerable populations.

Applicability of Research to Practice

The algorithm produced by this project while detailed, is a universal approach and can be implemented and adapted by any first line or receiving facility. Moving forward there will be collaborative efforts to conduct exercises involving identification, stabilization, and initial resuscitation of a simulated pediatric burn case at the community hospital for which this diagram was developed for. It is our goal to keep this momentum going and conduct these simulations regularly in order to test the system and make improvements to the algorithm.
786 Guardian Refusal for Pediatric Burn Surgery, What Providers Need to Understand
Authors: Libraro Kaitlyn , Heffernan Jamie , Lorico Jeremiah , Lodescar Rachelle J , Rabbitts Angela
Published: March 2020

Introduction

Pediatric patients, between the age of newborn and 18 years, require legal guardian consent for any surgical procedure. In some cases, despite medical advisement, guardians refuse excision and skin graft for a minor in their care. In these cases, extended healing times, re-admission, scaring, contracture and physical disability may ensue. Our study aims to review contributing factors of guardian refusal and explore the outcomes of such refusals.

Methods

Retrospective chart review of all pediatric patients admitted to a large verified burn center between January 2018 through May 2019 were reviewed for total body surface area (TBSA) burned, age, depth of wound, mechanism, MD recommendation for surgical procedure, operative procedures conducted and length of hospital stay (LOS).

Results

Of the 265 pediatric patients admitted to the Burn Service, 32 (12%) were recommended surgical intervention during their hospitalization. Of these, 25 (78%) guardians consented for surgical skin grafting procedures following recommendation; 3 (9%) guardians delayed treatment consent by an average of 5 days; and 4 (13%) refused surgical consent for skin grafting procedures entirely. The average TBSA for patients recommended for surgical intervention was 8.7, those who accepted surgical intervention had an average TBSA of 8.35, compared to the 11.25 TBSA who refused surgical intervention. Average inpatient length of stay for patients whose guardians consented to surgical intervention promptly was 15.8 days. Despite an average 5 day delay in consent, guardians who deferred consent for surgical intervention doubled their length of stay (31.1 inpatient days). The four guardians who refused recommended surgical intervention had an average inpatient stay of 8.25 days. This finding is consistent with multi-day dressing use and outpatient clinic management. Of note, the four patients that did not receive surgical intervention for burn wound management were linked by common cultural background.

Conclusions

Pediatric burn injury is both acute and chronic, and the shock of initial injury is often overwhelming for both the patient and the guardian. Furthermore, guardians are then asked to make surgical decisions for a minor in their care. The burn team needs to have a heightened awareness of the cultural norms in the communities they serve to ensure quality care deliverance and patient safety.

Applicability of Research to Practice

Directly Applicable.
791 Institutional Experience Using a Treatment Algorithm for Electrical Injury
Authors: Nisar Saira , Keyloun John W , McLawhorn Melissa M , Moffatt Lauren T , Travis Taryn E , Shupp Jeffrey W , Johnson Laura S
Published: March 2020

Introduction

Electrical injury has a low incidence, however is often associated with significant morbidity and mortality. There is some variability in the initial diagnosis and management of patients injured by electricity among institutions. This is particularly evident when non-burn specialists are managing care. This may result in unnecessary testing, monitoring, or admissions. The goal of this study was to examine the effectiveness of an electrical injury treatment algorithm (Figure), aimed to identify patients at risk for complications and reduce unnecessary investigations.

Methods

After IRB approval, demographics, laboratory tests, length of stay, telemetry monitoring, and disposition were collected for patients arriving to a regional burn center with the diagnosis of electrical injury from December 2012 to September 2018. Patients with arc injury were treated based on thermal injury algorithm and thus were excluded. Results were compared for patients who were admitted with electrical injury before and after implementation of the algorithm in July 2015.

Results

Fifty-eight patients were included in the pre-algorithm cohort and 38 in the post-algorithm cohort. Mean age in both groups was 36±12. There were no significant differences between groups in age, cutaneous burn area or gender. Incidence of creatine kinase, troponin, and urinary myoglobin testing in pre-algorithm cohort was significantly higher compared to post-algorithm cohort (81% vs. 47%, p< 0.05, 77% vs. 34%, p< 0.05 and 79% vs. 45%, p< 0.05 respectively). There was a trend towards higher number of days on telemetry prior to the protocol implementation but this was not found to be significant (3.6±6 vs. 1.1±0.3, p=0.054). One patient in each cohort had a pre-hospital cardiac arrest and attended the hospital with ACLS in progress and was subsequently pronounced dead. There were no significant differences in length of stay (6±11 vs. 3±3.6, p=0.11) or intensive care unit admission (33% vs. 27%, p=0.5).

Conclusions

An electrical injury treatment algorithm provides a way to triage patients appropriately for admission to the hospital and reducing the number of laboratory tests. Continued data collection and targeted quality improvement will guide further protocolization for the management of these patients. This will ultimately reduce unnecessary admissions to the hospital and the amount of clinical testing without affecting outcomes.

Applicability of Research to Practice

Electrical injury treatment algorithm provides a way to triage patients appropriately for admission to the burn center and reduces unnecessary investigation.
812 Standardization of Burn Pain Control in the Outpatient Burn Population
Authors: Sturgill Karli , Lou Richard B , Bard Maryke
Published: March 2020

Introduction

Nationwide there is a recognized need for regulation and standardization of prescription opioids for acute pain due to the opioid epidemic. Limited data exists about standardization of burn pain treatment in the outpatient setting; however, there are various treatment plans and minimal regulation of opioid prescriptions. The purpose of this study was to create a method of standardization of burn pain treatment and prescription of opioids for the burn outpatient.

Methods

A retrospective chart review was performed analyzing burn outpatient pain control regimens and indications for prescription opioids at a verified burn center. Factors such as burn size (TBSA), anatomical location, hospital length of stay, procedural sedation use, past medical history, surgical intervention, time since surgery, and psych history or elevated depression score were examined to create an objective scorecard. From the collected data, a treatment tier was created using ibuprofen and acetaminophen alternation as baseline pain control. The second and third tiers added oxycodone in increasing frequency for breakthrough of severe pain. Two exceptions were created for active cellulitis and a burn presenting in the first 12 hours since injury. Remaining unused opioid doses were also reviewed.

Results

Preliminary data collected from a 3 month trial demonstrated no significant change in the amount of opioids prescribed. There were 136 patients treated by burn advanced practice providers and the scorecard was used on 68 patients. On average, 7 opioid unused doses were remaining. Data using the current scorecard continues to be collected in the outpatient burn population.

Conclusions

Initial results conclude that there was no significant change in the amount of opioids prescribed but compliance was found to be a limiting factor in the data, as the scorecard was only used in 50% of the patients treated by the burn advance practice providers. Additional studies are needed to quantify improved compliance, patient satisfaction and increase in patient education on the treatment of pain.

Applicability of Research to Practice

A pain medication tool to standardize pain treatment for the outpatient may be valuable in burn centers.
870 Delineation of Burn Surgery Coaching Trees: Describing Generational Influences of Leadership in Burn Care
Authors: Joe Victor C
Published: March 2020

Introduction

Genealogies, or family trees, provide graphic representations of family history, tracing lines of decent among its members. Professional sports, most notably the National Football League (NFL), have borrowed this concept in delineating “coaching trees”. Connections among coaches can be described by the head coach-assistant coach relationships and utilized to demonstrate philosophical influences among coaches. This project was an attempt to explore the application of this concept to the profession of burn surgery and see if it could provide insight into the relationships (i.e., mentorship) that have influenced generations of burn surgeons over the past fifty years.

Methods

The first step in the process was to examine data sources. This consisted of gleaning information from the American Burn Association (ABA) archives (1976–1996) housed at the National Library of Medicine, the digital archives of the ABA, relevant review of the peer-reviewed literature, the public domain (world wide web), and documentation from various burn programs. The next step was to consider varying methodological approaches to the construction of the tree.

Results

While coaching relationships in the NFL represent a complex adaptive network, the relationships in an burn surgical coaching tree represent an even more complex network and the analogies between the two systems break down. As an exploratory project, the decision was made to construct several different trees with relative simple relational lines, concentrating central nodes on various past association presidents, prominent burn directors, and robust burn fellowship programs. This was done to illustrate proof-of-concept and inform future iterations of the project.

Conclusions

Creating burn surgery coaching trees can be done demonstrating relatively simple relational lines and provide basic illustrations of the influences of leadership among generations and institutions. More advanced mathematical and social science methodologies can be applied to explore these relationships in greater depth and elucidate a more thorough understanding of successful relationships, mentorship, and leadership dynamics in this complex adaptive network.

Applicability of Research to Practice

The description of coaching trees provides important insights into the history of burn surgery and the process can be replicated for other professions represented on the burn care team. It validates the importance of maintaining robust archives for our posterity. The information thus organized may inform the approach of the organization and/or inclined individual leaders on how mentorship occurs within our profession.
Innovation Considerations in Horizontal Merger Control
Authors: Kokkoris Ioannis , Valletti Tommaso
Published: March 2020

This paper focuses on the assessment of mergers and in particular on unilateral effects analysis where innovation plays an important role. The paper discusses the economic theories behind innovation, how we move from the traditional product-by-product market definition to pipeline competition and innovation competition and the concept of innovation space. The paper provides a structural analysis of unilateral effects in such markets analyzing how competition authorities should assess a transaction where the main theory of harm is based on innovation considerations.
Involvement of a truncated MADS-box transcription factor ZmTMM1 in root nitrate foraging
Authors: Liu Ying , Jia Zhongtao , Li Xuelian , Wang Zhangkui , Chen Fanjun , Mi Guohua , Forde Brian , Takahashi Hideki , Yuan Lixing
Published: March 2020

Plants can develop root systems with distinct anatomical features and morphological plasticity to forage nutrients distributed heterogeneously in soils. Lateral root proliferation is a typical nutrient-foraging response to a local supply of nitrate, which has been investigated across many plant species. However, the underlying mechanism in maize roots remains largely unknown. Here, we report on identification of a maize truncated MIKC-type MADS-box transcription factor (ZmTMM1) lacking K- and C-domains, expressed preferentially in the lateral root branching zone and induced by the localized supply of nitrate. ZmTMM1 belongs to the AGL17-like MADS-box transcription factor family that contains orthologs of ANR1, a key regulator for root nitrate foraging in Arabidopsis. Ectopic overexpression of ZmTMM1 recovers the defective growth of lateral roots in the Arabidopsis anr1 agl21 double mutant. The local activation of glucocorticoid receptor fusion proteins for ZmTMM1 and an artificially truncated form of AtANR1 without the K- and C-domains stimulates the lateral root growth of the Arabidopsis anr1 agl21 mutant, providing evidence that ZmTMM1 encodes a functional MADS-box that modulates lateral root development. However, no phenotype was observed in ZmTMM1-RNAi transgenic maize lines, suggesting a possible genetic redundancy of ZmTMM1 with other AGL17-like genes in maize. A comparative genome analysis further suggests that a nitrate-inducible transcriptional regulation is probably conserved in both truncated and non-truncated forms of ZmTMM1-like MADS-box transcription factors found in grass species.
Radiative AGN feedback on a moving mesh: the impact of the galactic disc and dust physics on outflow properties
Authors: Barnes David J , Kannan Rahul , Vogelsberger Mark , Marinacci Federico
Published: March 2020

Feedback from accreting supermassive black holes (BHs), active galactic nuclei (AGNs), is now a cornerstone of galaxy formation models. In this work, we present radiation-hydrodynamic simulations of radiative AGN feedback using the novel arepo-rt code. A central BH emits radiation at a constant luminosity and drives an outflow via radiation pressure on dust grains. Utilizing an isolated Navarro–Frenk–White (NFW) halo we validate our set-up in the single- and multiscattering regimes, with the simulated shock front propagation in excellent agreement with the expected analytic result. For a spherically symmetric NFW halo, an examination of the simulated outflow properties with radiation collimation demonstrates a decreasing mass outflow rate and momentum flux, but increasing kinetic power and outflow velocity with decreasing opening angle. We then explore the impact of a central disc galaxy and the assumed dust model on the outflow properties. The contraction of the halo during the galaxy’s formation and modelling the production of dust grains result in a factor 100 increase in the halo’s optical depth. Radiation then couples momentum more efficiently to the gas, driving a stronger shock and producing a mass-loaded $\sim \!10^{3}\, \mathrm{M}_{\odot }\, \mathrm{yr}^{-1}$ outflow with a velocity of $\sim \!2000\, \mathrm{km}\, \mathrm{s}^{-1}$. However, the inclusion of dust destruction mechanisms, like thermal sputtering, leads to the rapid destruction of dust grains within the outflow, reducing its properties below the initial NFW halo. We conclude that radiative AGN feedback can drive outflows, but a thorough numerical and physical treatment is required to assess its true impact.
Modelling the tightest relation between galaxy properties and dark matter halo properties from hydrodynamical simulations of galaxy formation
Authors: He Jian-hua
Published: March 2020

We investigate how a property of a galaxy correlates most tightly with a property of its host dark matter halo, using state-of-the-art hydrodynamical simulations of galaxy formation: EAGLE, Illustris, and IllustrisTNG. Unlike most of the previous work, our analyses focus on all types of galaxies, including both central and satellite galaxies. We find that the stellar mass of a galaxy at the epoch of the peak circular velocity with an evolution correction gives the tightest such correlation to the peak circular velocity Vpeak of the galaxy’s underling dark matter halo. The evolution of galaxy stellar mass reduces rather than increases scatter in such a relation. We also find that one major source of scatter comes from star stripping due to the strong interactions between galaxies. Even though, we show that the size of scatter predicted by hydrodynamical simulations has a negligible impact on the clustering of dense Vpeak-selected subhalo from simulations, which suggests that even the simplest subhalo abundance matching (SHAM), without scatter and any additional free parameter, can provide a robust prediction of galaxy clustering that can agree impressively well with the observations from the Sloan Digital Sky Survey (SDSS) main galaxy survey.
Limitations to the ‘basic’ HOD model and beyond
Authors: Hadzhiyska Boryana , Bose Sownak , Eisenstein Daniel , Hernquist Lars , Spergel David N
Published: March 2020

We use the IllustrisTNG cosmological, hydrodynamical simulations to test fundamental assumptions of the mass-based halo occupation distribution (HOD) approach to modelling the galaxy–halo connection. By comparing the clustering of galaxies measured in the 300 Mpc TNG box (TNG300) with that predicted by the standard (basic) HOD model, we find that, on average, the ‘basic’ HOD model underpredicts the real-space correlation function in the TNG300 box by ∼15 per cent on scales of $1 \,\,\lt\,\, r \,\,\lt\,\, 20 \ {\rm Mpc}\, h^{-1}$, which is well beyond the target precision demanded of next-generation galaxy redshift surveys. We perform several tests to establish the robustness of our findings to systematic effects, including the effect of finite box size and the choice of halo finder. In our exploration of ‘secondary’ parameters with which to augment the ‘basic’ HOD, we find that the local environment of the halo, the velocity dispersion anisotropy, β, and the product of the half-mass radius and the velocity dispersion, σ2Rhalfmass, are the three most effective measures of assembly bias that help reconcile the ‘basic’ HOD-predicted clustering with that in TNG300. In addition, we test other halo properties such as halo spin, formation epoch, and halo concentration. We also find that at fixed halo mass, galaxies in one type of environment cluster differently from galaxies in another. We demonstrate that a more complete model of the galaxy–halo connection can be constructed if we combine both mass and local environment information about the halo.
The VMC survey – XXXVI. Young stellar variability in the Large Magellanic Cloud
Authors: Zivkov Viktor , Oliveira Joana M , Petr-Gotzens Monika G , Rubele Stefano , Cioni Maria-Rosa L , van Loon Jacco Th , de Grijs Richard , Emerson Jim , Ivanov Valentin D , Marconi Marcella , Moretti Maria Ida , Ripepi Vincenzo , Niederhofer Florian , Sun Ning-Chen
Published: March 2020

Studies of young stellar objects (YSOs) in the Galaxy have found that a significant fraction exhibits photometric variability. However, no systematic investigation has been conducted on the variability of extragalactic YSOs. Here we present the first variability study of massive YSOs in an $\sim 1.5\, \mathrm{deg^2}$ region of the Large Magellanic Cloud (LMC). The aim is to investigate whether the different environmental conditions in the metal-poor LMC ($\sim 0.4\!-\!0.5\, \mathrm{Z_{\odot }}$) have an impact on the variability characteristics. Multi-epoch near-infrared (NIR) photometry was obtained from the VISTA Survey of the Magellanic Clouds (VMC) and our own monitoring campaign using the VISTA telescope. By applying a reduced χ2-analysis, stellar variability was identified. We found 3062 candidate variable stars from a population of 362 425 stars detected. Based on several Spitzer studies, we compiled a sample of high-reliability massive YSOs: a total of 173 massive YSOs have NIR counterparts (down to $K_s\sim 18.5\,$mag) in the VMC catalogue, of which 39 display significant (>3σ) variability. They have been classified as eruptive, fader, dipper, short-term variable, and long-period variable YSOs based mostly on the appearance of their Ks-band light curves. The majority of YSOs are aperiodic; only five YSOs exhibit periodic light curves. The observed amplitudes are comparable or smaller than those for Galactic YSOs (only two Magellanic YSOs exhibit $\Delta K_s\gt 1\,$mag), not what would have been expected from the typically larger mass accretion rates observed in the Magellanic Clouds.
Dynamics of genetic variation in transcription factors and its implications for the evolution of regulatory networks in Bacteria
Authors: Ali Farhan , Seshasayee Aswin Sai Narain
Published: March 2020

The evolution of regulatory networks in Bacteria has largely been explained at macroevolutionary scales through lateral gene transfer and gene duplication. Transcription factors (TF) have been found to be less conserved across species than their target genes (TG). This would be expected if TFs accumulate mutations faster than TGs. This hypothesis is supported by several lab evolution studies which found TFs, especially global regulators, to be frequently mutated. Despite these studies, the contribution of point mutations in TFs to the evolution of regulatory network is poorly understood. We tested if TFs show greater genetic variation than their TGs using whole-genome sequencing data from a large collection of Escherichia coli isolates. TFs were less diverse than their TGs across natural isolates, with TFs of large regulons being more conserved. In contrast, TFs showed higher mutation frequency in adaptive laboratory evolution experiments. However, over long-term laboratory evolution spanning 60 000 generations, mutation frequency in TFs gradually declined after a rapid initial burst. Extrapolating the dynamics of genetic variation from long-term laboratory evolution to natural populations, we propose that point mutations, conferring large-scale gene expression changes, may drive the early stages of adaptation but gene regulation is subjected to stronger purifying selection post adaptation.
Dual BRAF/MEK blockade restores CNS responses in BRAF-mutant Erdheim–Chester disease patients following BRAF inhibitor monotherapy
Authors: Mazor Roei D , Weissman Ran , Luckman Judith , Domachevsky Liran , Diamond Eli L , Abdel-Wahab Omar , Shapira Shirley , Hershkovitz-Rokah Oshrat , Groshar David , Shpilberg Ofer
Published: March 2020

Background

Erdheim–Chester disease (ECD), a rare inflammatory myeloid neoplasm, is known to be fundamentally reliant on the constitutive activation of the MAPK signaling pathway in the majority of patients. Consequently, inhibition of the V600E-mutant BRAF kinase has proven to be a safe and efficacious long-term therapeutic strategy for BRAF-mutant ECD patients. Nevertheless, in a subset of patients with CNS disease, the efficacy of long-term treatment may diminish, facilitating suboptimal responses or disease progression.

Methods

We retrospectively describe 3 BRAF-mutant ECD patients whose treatment with Vemurafenib was upgraded to Vemurafenib/Cobimetinib due to either disease progression, insufficient response, or unacceptable toxicity. CNS response to therapy was evaluated using magnetic resonance imaging (MRI) and extra-cranial disease was monitored using 18F-fludeoxyglucose positron emission tomography/computed tomography (PET/CT).

Results

Three patients with a mean age of 52.6 years were treated with Vemurafenib for a mean duration of 26.6 months (range: 6–52). Monotherapies were upgraded to Vemurafenib/Cobimetinib dual therapy. The combination therapy was administered for a mean duration of 21 months (range: 19–23). All patients exhibited clinical and neurological improvement. Regression of lesions on MRI was noted in 2 patients. Both patients characterized by a PET-avid disease responded to the biological treatment regimen with complete metabolic remissions.

Conclusion

Dual inhibition of BRAF and downstream MEK may be a safe and effective therapeutic strategy for BRAF-mutant ECD patients for whom BRAF inhibitor therapy proved insufficient and as such appropriate for the long-term management of CNS disease in ECD.
Dynamics of Intra-Party Organisation in the Digital Age: A Grassroots Analysis of Digital Adoption
Authors: Dommett Katharine , Temple Luke , Seyd Patrick
Published: March 2020

Over recent decades, scholars have explored political parties’ adoption of digital technology. Tracing successive eras of change, scholarship has examined the degree to which digital disrupts or embeds traditional power structures—with many studies finding evidence of ‘controlled-interactivity’. In this article, we revisit debates around the adoption of digital tools from a bottom-up perspective. Moving beyond attempts to categorise elite strategies for digital adoption, we consider practices on the ground to document how, in practice, digital technology is being taken up and used. Using a case study of the UK Labour Party, we categorise a range of different practices, highlighting and theorising the presence of digital adherents, laggards, entrepreneurs, renegades and refuseniks. Discussing the drivers of these practices, we offer new insight into variations in digital adoption and consider the significance of these trends for our understanding of party organisation.
Social support and public health promotion in ‘The man in a box’
Authors: Van Overmeire Roel
Published: March 2020

In this short reflection, a story by Anton Chekhov is used to analyze the link between public health promotion and social support. Social support is important in overcoming mental health problems. However, social support might not always understand the problems someone has, or the person with mental health problems might not be able to express the problems he/she has. Public health promotion is important, because it helps family, friends and colleagues of people with mental health problems understand those problems, and helps those people with mental health problems express themselves toward family, friends and colleagues. This idea is illustrated by using the main character in a story by Anton Chekhov, who is presented as someone without any social support: he cannot express himself toward the townspeople, nor do the townspeople understand him. This short reflection ends with a reminder of the importance of public health promotion, to create understanding for mental health and thus increase access to social support.
Consistent altered internal capsule white matter microstructure in insomnia disorder
Authors: Bresser Tom , Foster-Dingley Jessica C , Wassing Rick , Leerssen Jeanne , Ramautar Jennifer R , Stoffers Diederick , Lakbila-Kamal Oti , van den Heuvel Martijn , van Someren Eus J W
Published: March 2020

Study Objectives

Suggested neural correlates of insomnia disorder have been hard to replicate. Even the most consistent finding, altered white matter microstructure in the anterior limb of the internal capsule, is based on handful studies. The urge for replicable targets to understand the underlying mechanisms of insomnia made us study white matter fractional anisotropy (FA) across three samples of cases and controls.

Methods

3-Tesla MRI diffusion tensor imaging data of three independent samples were combined for analysis, resulting in n = 137 participants, of whom 73 were diagnosed with insomnia disorder and 64 were matched controls without sleep complaints. Insomnia severity was measured with the Insomnia Severity Index (ISI). White matter microstructure was assessed with FA. White matter tracts were skeletonized and analyzed using tract-based spatial statistics. We performed a region-of-interest analysis using linear mixed-effect models to evaluate case–control differences in internal capsule FA as well as associations between internal capsule FA and insomnia severity.

Results

FA in the right limb of the anterior internal capsule was lower in insomnia disorder than in controls (β = −9.76e−3; SE = 4.17e−3, p = .034). In the entire sample, a higher ISI score was associated with a lower FA value of the right internal capsule (β = −8.05e− 4 FA/ISI point, SE = 2.60e− 4, p = .008). Ancillary whole brain voxel-wise analyses showed no significant group difference or association with insomnia severity after correction for multiple comparisons.

Conclusions

The internal capsule shows small but consistent insomnia-related alterations. The findings support a circuit-based approach to underlying mechanisms since this tract connects many brain areas previously implicated in insomnia.
New hemagglutinin dual-receptor-binding pattern of a human-infecting influenza A (H7N9) virus isolated after fifth epidemic wave
Authors: Guo Lei , Li Nan , Li Wenlong , Zhou Jienan , Ning Ruotong , Hou Min , Liu Longding
Published: March 2020

Since 2013, influenza H7N9 virus has caused five epidemic waves of human infection. The virus evolved from low pathogenic to highly pathogenic in wave 5, 2017, while the prevalence of host receptor-binding tropism in human-infecting viruses maintained dual-receptor-binding property with preference for avian receptor. A human-infecting H7N9 virus was isolated after the fifth epidemic wave and possessed an avian and human dual-receptor specificity, with a moderately higher affinity for human receptor binding. A V186I (H3 numbering) substitution in the receptor-binding site of the hemagglutinin (HA) molecule is responsible for the alteration of the dual-receptor-binding tropism. Viral strains which contain I186 amino acid of avian- and human-infecting H7N9 viruses were all isolated during or after wave 5, and their HA genes clustered in a same phylogenetic clade together with 2018–9 H7N9 isolates, highlights a new evolutionary path for human adaption of natural H7N9 viruses.
It may be a stroke, it may be meningo-encephalitis
Authors: Pan Daniel , Bridges Leslie , Cosgrove Catherine , Zhang Liqun
Published: March 2020

An 85-year old lady originally from Gujurat presented to the emergency department with sudden onset left sided weakness and slurred speech. Stroke was suspected. Computed tomography (CT) of the head showed bilateral multiple cortical and subcortical hypodense lesions; magnetic resonance imaging revealed that these lesions were ring enhancing with oedema. Lumbar puncture found an opening pressure of 22cm H2O, 98% lymphocytes (60x106/L) in the cerebrospinal fluid with a normal glucose (6.1mg/L) and high protein (0.66 mg/L). Cerebrospinal fluid culture, PCR and cytology were all negative. The patient was started on empirical therapy for tuberculous meningitis. A subsequent CT chest, abdomen and pelvis however did not find any other significant pathology.

Unfortunately, soon after her investigations, the woman rapidly deteriorated. A joint medical decision was made to shift focus of treatment to palliative care. After death, post-mortem found multiple irregular haemorrhagic solid lesions with dark brown edges. Histopathology confirmed extensive areas of necrosis, within which there were multiple amoebic trophozoites and cysts. A diagnosis of amoebic (it may be) meningo-encephalitis was made. These were thought to be free-living amoebae.

Free-living amoebae are ubiquitous to the environment, and exposure is common. The incidence of amoebic encephalitis however is rare and usually occurs in immunocompromised patients. Portal of entry, especially in cases where the cerebrospinal fluid protein is only mildly raised or normal, is thought to be through the nose or eyes (for example, Acanthamoeba keratitis from contact lenses). Clinicians should consider this as a differential diagnosis for any patient with multiple brain abscesses.