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Many studies have reported associations between prenatal stress and the development of psychotic, anxiety and depressive disorders; however, to date no studies have investigated potential associations with personality disorders.
Aims
This study investigated potential associations between exposure to prenatal stress and personality disorder in offspring.
Method
In a subsample (N = 3626) of a large Finnish birth cohort, we used logistic regression models to examine associations between self-reported maternal stress during pregnancy, collected monthly during antenatal clinic appointments, and personality disorder in offspring. Familial and outcome information were obtained by linking data from the Finnish Hospital Discharge Register and the Finnish Population Register.
Results
Compared with those unexposed, children exposed to any maternal stress during gestation had three times the odds of developing a personality disorder (odds ratio 3.28, 95% CI 1.75–6.15, P < 0.0001). Those exposed to moderate stress had three times the odds (odds ratio 3.13, 95% CI 1.42–6.88, P = 0.005) and those exposed to severe stress had seven times the odds (odds ratio 7.02, 95% CI 2.08–23.66, P = 0.002) of developing a personality disorder. These associations remained after adjusting for parental psychiatric history, comorbid psychiatric diagnoses, prenatal smoking and antenatal depression.
Conclusions
Exposure to stress during gestation increases the odds of personality disorder in offspring, independent of other psychiatric disorders. These results suggest the assessment of maternal stress and well-being during pregnancy may be useful in identifying those at greatest risk of developing personality disorder, and highlight the importance of prenatal care for good maternal mental health during pregnancy.
The rocky shores of the north-east Atlantic have been long studied. Our focus is from Gibraltar to Norway plus the Azores and Iceland. Phylogeographic processes shape biogeographic patterns of biodiversity. Long-term and broadscale studies have shown the responses of biota to past climate fluctuations and more recent anthropogenic climate change. Inter- and intra-specific species interactions along sharp local environmental gradients shape distributions and community structure and hence ecosystem functioning. Shifts in domination by fucoids in shelter to barnacles/mussels in exposure are mediated by grazing by patellid limpets. Further south fucoids become increasingly rare, with species disappearing or restricted to estuarine refuges, caused by greater desiccation and grazing pressure. Mesoscale processes influence bottom-up nutrient forcing and larval supply, hence affecting species abundance and distribution, and can be proximate factors setting range edges (e.g., the English Channel, the Iberian Peninsula). Impacts of invasive non-native species are reviewed. Knowledge gaps such as the work on rockpools and host–parasite dynamics are also outlined.
Prehospital identification of large vessel occlusion (LVO) stroke may expedite treatment by direct transport to comprehensive stroke centers (CSCs) with endovascular capabilities. The Cincinnati Prehospital Stroke Scale (CPSS) is commonly used for prehospital stroke detection. We aimed to assess whether (1) a high CPSS score can identify LVO and (2) an Emergency Medical Service (EMS) redirection protocol based on high CPSS accelerated endovascular treatment (EVT).
Methods:
A retrospective comparison of patients transported by EMSs for suspected stroke to a high-volume CSC over a 16-month period, before and after implementation of an EMS redirection protocol based on high CPSS score (3/3). Charts were reviewed to determine the presence of LVO. Time to EVT and 3-month outcomes were compared before and after implementation.
Results:
A prehospital CPSS 3/3 score was found in 223 (59%) patients, demonstrating positive and negative predictive values for LVO of 29% and 94%, respectively. CPSS-based EMS redirection increased the proportion of EVT performed after direct transport to CSC [before: 21 (36%), after: 45 (63%), p < 0.01] and decreased median first door-to-groin puncture time by 28 minutes [109 (interquartile range (IQR) 64–116) versus 81 (IQR 56–130), p = 0.03]. At 3 months, the proportion of patients achieving functional independence (modified Rankin score 0–2) went from 20/57 (35%) to 29/68 (43%) (p = 0.39) following implementation.
Conclusions:
CPSS-based EMS redirection accelerated identification of LVO strokes in the out-of-hospital setting and decreased time to EVT. Nevertheless, this protocol was also associated with high rates of non-LVO stroke. Impact on clinical outcomes should be evaluated in a larger cohort.
Background: Buprenorphine/naloxone (bup/nal) is a partial opioid agonist/antagonist and recommended first line treatment for opioid use disorder (OUD). Emergency departments (EDs) are a key point of contact with the healthcare system for patients living with OUD. Aim Statement: We implemented a multi-disciplinary quality improvement project to screen patients for OUD, initiate bup/nal for eligible individuals, and provide rapid next business day walk-in referrals to addiction clinics in the community. Measures & Design: From May to September 2018, our team worked with three ED sites and three addiction clinics to pilot the program. Implementation involved alignment with regulatory requirements, physician education, coordination with pharmacy to ensure in-ED medication access, and nurse education. The project is supported by a full-time project manager, data analyst, operations leaders, physician champions, provincial pharmacy, and the Emergency Strategic Clinical Network leadership team. For our pilot, our evaluation objective was to determine the degree to which our initiation and referral pathway was being utilized. We used administrative data to track the number of patients given bup/nal in ED, their demographics and whether they continued to fill bup/nal prescriptions 30 days after their ED visit. Addiction clinics reported both the number of patients referred to them and the number of patients attending their referral. Evaluation/Results: Administrative data shows 568 opioid-related visits to ED pilot sites during the pilot phase. Bup/nal was given to 60 unique patients in the ED during 66 unique visits. There were 32 (53%) male patients and 28 (47%) female patients. Median patient age was 34 (range: 21 to 79). ED visits where bup/nal was given had a median length of stay of 6 hours 57 minutes (IQR: 6 hours 20 minutes) and Canadian Triage Acuity Scores as follows: Level 1 – 1 (2%), Level 2 – 21 (32%), Level 3 – 32 (48%), Level 4 – 11 (17%), Level 5 – 1 (2%). 51 (77%) of these visits led to discharge. 24 (47%) discharged patients given bup/nal in ED continued to fill bup/nal prescriptions 30 days after their index ED visit. EDs also referred 37 patients with OUD to the 3 community clinics, and 16 of those individuals (43%) attended their first follow-up appointment. Discussion/Impact: Our pilot project demonstrates that with dedicated resources and broad institutional support, ED patients with OUD can be appropriately initiated on bup/nal and referred to community care.
We read with interest the recent editorial, “The Hennepin Ketamine Study,” by Dr. Samuel Stratton commenting on the research ethics, methodology, and the current public controversy surrounding this study.1 As researchers and investigators of this study, we strongly agree that prospective clinical research in the prehospital environment is necessary to advance the science of Emergency Medical Services (EMS) and emergency medicine. We also agree that accomplishing this is challenging as the prehospital environment often encounters patient populations who cannot provide meaningful informed consent due to their emergent conditions. To ensure that fellow emergency medicine researchers understand the facts of our work so they may plan future studies, and to address some of the questions and concerns in Dr. Stratton’s editorial, the lay press, and in social media,2 we would like to call attention to some inaccuracies in Dr. Stratton’s editorial, and to the lay media stories on which it appears to be based.
Ho JD, Cole JB, Klein LR, Olives TD, Driver BE, Moore JC, Nystrom PC, Arens AM, Simpson NS, Hick JL, Chavez RA, Lynch WL, Miner JR. The Hennepin Ketamine Study investigators’ reply. Prehosp Disaster Med. 2019;34(2):111–113
OBJECTIVES/SPECIFIC AIMS: To introduce CCTS to the clinical and translational research community. METHODS/STUDY POPULATION: Established in the summer of 2017, the Center for Clinical and Translational Science (CCTS) fosters cooperative clinical and translational sciences between the University of Mississippi School of Pharmacy (UMSOP) and the University of Mississippi Medical Center (UMMC). CCTS facilitates the translation of basic research discoveries into clinically validated therapies to improve the health of populations in Mississippi and beyond. Priority areas of investigation in CCTS include Cardiometabolic disorders, Cancer, Neuroscience, Infectious diseases, Precision Medicine, and Community-Based Research. To accomplish CCTS mission three overarching goals have been defined: I) Develop progressive and sustainable capacity for clinical and translational research in Mississippi; II) Promote interprofessional engagement in clinical and translational science; and III) Foster research collaboration among stakeholders in and outside of Mississippi. RESULTS/ANTICIPATED RESULTS: To carry its CCTS’s mission three research units have been established: 1) The Pre-clinical Research Unit: Develops processes to move basic science discoveries towards translation into research in humans. This unit provides guidance in the development of Investigational New Drug (IND) applications; and identifies and pursues opportunities to develop progressive capacities for in vitro, ex vivo, in vivo, and in silico approaches for evaluating new pharmaceutical and therapeutic agents. 2) The Clinical Research Unit: Transitions projects that have received IND approval into the first phase of clinical trials. It also transitions clinical trials from Phase I to Phase II and to Phase III; develops standard operating procedures (SOPs), personnel training plans, and policies to guide clinical research; works with industry sponsors and governmental funding agencies; and assures compliance with regulatory requirements. 3) Community/population Research Unit: Develops, coordinates, and facilitates research activities and translation between clinical and community/population research stages. To do so, this unit works closely with community partners and Population Health programs on the Oxford and Jackson campuses. DISCUSSION/SIGNIFICANCE OF IMPACT: Since its inception, the CCTS has surpassed 1.5 million dollars in competitive funding. This early success positions the CCTS well to promote research collaboration between UMSOP and UMMC and to progress in becoming a national leader in clinical and translational investigation.
The effects of the slope of an ice–seawater interface on the mechanisms and rate of ablation of the ice by natural convection are examined using turbulence-resolving simulations. Solutions are obtained for ice slopes
$\unicode[STIX]{x1D703}=2^{\circ }{-}90^{\circ }$
, at a fixed ambient salinity and temperature, chosen to represent common Antarctic ocean conditions. For laminar boundary layers the ablation rate decreases with height, whereas in the turbulent regime the ablation rate is found to be height independent. The simulated laminar ablation rates scale with
$(\sin \unicode[STIX]{x1D703})^{1/4}$
, whereas in the turbulent regime it follows a
$(\sin \unicode[STIX]{x1D703})^{2/3}$
scaling, both consistent with the theoretical predictions developed here. The reduction in the ablation rate with shallower slopes arises as a result of the development of stable density stratification beneath the ice face, which reduces turbulent buoyancy fluxes to the ice. The turbulent kinetic energy budget of the flow shows that, for very steep slopes, both buoyancy and shear production are drivers of turbulence, whereas for shallower slopes shear production becomes the dominant mechanism for sustaining turbulence in the convective boundary layer.
Effective treatment of maternal antenatal depression may ameliorate adverse neurodevelopmental outcomes in offspring. We performed two follow-up rounds of children at age 2 and age 5 whose mothers had received either specialized cognitive-behavioural therapy or routine care for depression while pregnant. Of the original cohort of 54 women, renewed consent was given by 28 women for 2-year follow-up and by 24 women for 5-year follow-up. Child assessments at the 2-year follow-up included the Parenting Stress Index (PSI), Bayley Scales of Infant Development (BSID-III) and the Child Behaviour Checklist (CBCL). The 5-year follow-up included the Wechsler Preschool and Primary Scales of Intelligence (WPPSI-III) and again the CBCL. Treatment during pregnancy showed significant benefits for children’s development at age 2, but not at age 5. At 2 years, intervention effects were found with lower scores on the PSI Total score, Parent Domain and Child domain (d=1.44, 1.47, 0.96 respectively). A non-significant trend favoured the intervention group on most subscales of the CBCL and the BSID-III (most notably motor development: d =0.52). In contrast, at 5-year follow-up, no intervention effects were found. Also, irrespective of treatment allocation, higher depression or anxiety during pregnancy was associated with higher CBCL and lower WPPSI-III scores at 5 years. This is one of the first controlled studies to evaluate the long-term effect of antenatal depression treatment on infant neurodevelopmental outcomes, showing some benefit. Nevertheless, caution should be taken interpreting the results because of a small sample size, and larger studies are warranted.
To examine neonatal risk factors associated with recurrent Staphylococcus aureus colonization and to determine the genetic relatedness of S. aureus strains cultured from neonates before and after decolonization.
Study design
Single-center retrospective cohort study of neonates admitted to the neonatal intensive care unit (NICU) from April 2013 to December 2015, during which weekly nasal cultures from hospitalized NICU patients were routinely obtained for S. aureus surveillance.
Setting
Johns Hopkins Hospital’s 45-bed level IV NICU in Baltimore, Maryland.
Methods
Demographics and clinical data were collected on all neonates admitted to the NICU with S. aureus nasal colonization who underwent mupirocin-based decolonization during the study period. A decolonized neonate was defined as a neonate with ≥1 negative culture after intranasal mupirocin treatment. Pulsed-field gel electrophoresis was used for strain typing.
Results
Of 2,060 infants screened for S. aureus, 271 (13%) were colonized, and 203 of these 271 (75%) received intranasal mupirocin. Of those treated, 162 (80%) had follow-up surveillance cultures, and 63 of these 162 infants (39%) developed recurrent colonization after treatment. The S. aureus strains were often genetically similar before and after decolonization. The presence of an endotracheal tube or nasal cannula/mask was associated with an increased risk of recurrent S. aureus colonization (hazard ratio [HR], 2.65; 95% confidence interval [CI], 1.19–5.90; and HR, 2.21; 95% CI, 1.02–4.75, respectively).
Conclusion
Strains identified before and after decolonization were often genetically similar, and the presence of invasive respiratory devices increased the risk of recurrent S. aureus nasal colonization in neonates. To improve decolonization efficacy, alternative strategies may be needed.
We aimed to assess the maternal and family determinants of four anthropometric typologies at the household level in Colombia for the years 2000, 2005 and 2010.
Design
We classified children <5 years old according to height-for-age Z-score (<−2) and BMI-for-age Z-score (>2) to assess stunting and overweight/obesity, respectively; mothers were categorized according to BMI to assess underweight (<18·5 kg/m2) and overweight/obesity (≥25·0 kg/m2). At the household level, we established four final anthropometric typologies: normal, underweight, overweight and dual-burden households. Separate polytomous logistic regression models for each of the surveyed years were developed to examine several maternal and familial determinants of the different anthropometric typologies.
Setting
National and sub-regional (urban and rural) representative samples from Colombia, South America.
Subjects
Drawing on data from three waves of Colombia’s Demographic and Health Survey/Encuesta Nacional de Salud (DHS/ENDS), we examined individual and household information from mothers (18–49 years) and their children (birth–5 years).
Results
Higher parity was associated with an increased likelihood of overweight and dual burden. Higher levels of maternal education were correlated with lower prevalence of overweight, underweight and dual burden of malnutrition in all data collection waves. In 2010, participation in nutrition programmes for children <5 years, being an indigenous household, food purchase decisions by the mother and food security classification were also associated with the four anthropometric typologies.
Conclusions
Results suggest that maternal and family correlates of certain anthropometric typologies at the household level may be used to better frame policies aimed at improving social conditions and nutrition outcomes.
We examine the dissolution of a sloping solid surface driven by turbulent compositional convection. The scaling analysis presented by Kerr & McConnochie (J. Fluid Mech., vol. 765, 2015, pp. 211–228) for the dissolution of a vertical wall is extended to the case of a sloping wall. The model has no free parameters and no dependence on height. It predicts that while the interfacial temperature and interfacial composition are independent of the slope, the dissolution velocity is proportional to
$\cos ^{2/3}\unicode[STIX]{x1D703}$
, where
$\unicode[STIX]{x1D703}$
is the angle of the sloping surface to the vertical. The analysis is tested by comparing it with laboratory measurements of the ablation of a sloping ice wall in contact with salty water. We apply the model to make predictions of the turbulent convective dissolution of a sloping ice shelf in the polar oceans.
Introduction: Patients suffering from out-of-hospital cardiac arrest (OHCA) with an initial shockable rhythm (ventricular tachycardia or ventricular fibrillation) have higher odds of survival than those suffering from non-shockable rhythm (asystole or pulseless electrical activity). Because of that prognostic significance, patients with an initial non-shockable rhythm are often not considered for advanced resuscitation therapies such as extracorporeal resuscitation. However, the prognostic significance of the conversion to a shockable rhythm from an initially non-shockable rhythm remains uncertain. This study aimed to determine the degree of association between the conversion (or not) of a non-shockable rhythm to a shockable rhythm and resuscitation outcomes in patients with OHCA. It was hypothesized that such a conversion would be associated with a higher survival to discharge. Methods: The present study used a registry of adult OHCA between 2010 and 2015 in Montreal, Canada. Adult patients with non-traumatic OHCA and an initial non-shockable rhythm were included. The primary outcome measure was survival to hospital discharge, and the secondary outcome measure was prehospital return of spontaneous circulation (ROSC). The associations of interest were evaluated with univariate logistic regressions and multivariate models controlling for demographic and clinical variables (e.g. age, gender, type of initial non-shockable rhythm, witnessed arrest, bystander cardiopulmonary resuscitation). Assuming a survival rate of 3% and 25% of the variability explained by the control variables, including more than 4580 patients would allow to detect an absolute difference of 4% in survival between both groups with a power of more than 90%. Results: A total of 4893 patients (2869 men and 2024 women) with a mean age of 70 years (standard deviation 17) were included, of whom 450 (9.2%) experienced a conversion to a shockable rhythm during the course of their prehospital resuscitation. Among all patients, 146 patients (3.0%) survived to discharge and 633 (12.9%) experienced prehospital ROSC. In the univariate models, there was no association between the conversion to a shockable rhythm and survival (odds ratio [OR] 1.14 [95% confidence interval {CI} 0.66-1.95]), but a significant assocation was observed with ROSC (OR 2.00 [95% CI 1.57-2.55], p<0.001). However, there was no independent association between the conversion to a shockable rhythm and survival (adjusted OR [AOR] 0.92 [95% CI 0.51-1.66], p=0.78) and prehospital ROSC (AOR 1.30 [95% CI 0.98-1.72], p=0.073). Conclusion: There is no clinically significant association between the conversion to a shockable rhythm and resuscitation outcomes in patients suffering from OHCA. The initial rhythm remains a much better outcome predictor than subsequent rhythms and should be preferred when evaluating the eligibility for advanced resuscitation procedures.
Introduction: Introduction: Paramedics frequently make immediate life-altering decisions with minimal clinical information. This applies to their decision to treat an unconscious patient with naloxone when the history of an opioid overdose cannot be readily established. Among patients treated by paramedics with naloxone, our objective was to compare patient demographics, treatment interventions and clinical response between patients with and without a confirmed history of an opioid overdose. Methods: Methods: This was a retrospective cohort study design of consecutive patients treated with naloxone by paramedics between January 1, 2016, and June 30, 2017. Patients were classified based on whether paramedics did or did not document a history of an opioid overdose. Baseline characteristics, treatment interventions, and response to naloxone were compared between groups. Comparisons were done using a chi-squared or Fishers exact test. Results: Results: We identified 294 patients of whom 113 (38%) did not have a confirmed history of an opioid overdose. The groups were similar in gender, bystander CPR, and bystander administration of naloxone. There were no differences in the presence of pinpoint pupils, initial oxygen saturation, initial Glasgow Coma Score (GCS), respiratory rate, or time on scene. Both patient groups were managed similarly with respect to route of naloxone administration and the use of a bag valve mask. All patients who were intubated were in the no confirmed history group (n=5; p=.003). Post naloxone there were no differences in last recorded vital signs except the no confirmed history group was less likely to achieve a GCS 10 (57% versus 89%; p<.001). The overall post-naloxone development of agitation (9%) was moderate while the need for physical/chemical restraint (2%) was low with no differences between groups. All patients were transported to the hospital. Conclusion: Conclusion: A substantial proportion of patients who received naloxone did not have a confirmed history of an opioid overdose. These patients closely resembled those with a confirmed history with respect to demographics and physical characteristics. The primary difference was a lower proportion of patients with no confirmed history who achieved a post naloxone GCS 10. Despite a moderate development of post naloxone agitation, paramedics were able to manage most of these patients without the use of physical/chemical restraints.
Network analysis is an emerging approach in the study of psychopathology, yet few applications have been seen in eating disorders (EDs). Furthermore, little research exists regarding changes in network strength after interventions. Therefore the present study examined the network structures of ED and co-occurring depression and anxiety symptoms before and after treatment for EDs.
Method
Participants from residential or partial hospital ED treatment programs (N = 446) completed assessments upon admission and discharge. Networks were estimated using regularized Graphical Gaussian Models using 38 items from the Eating Disorders Examination-Questionnaire, Quick Inventory of Depressive Symptomatology, and State-Trait Anxiety Inventory.
Results
ED symptoms with high centrality indices included a desire to lose weight, guilt about eating, shape overvaluation, and wanting an empty stomach, while restlessness, self-esteem, lack of energy, and feeling overwhelmed bridged ED to depression and anxiety symptoms. Comparisons between admission and discharge networks indicated the global network strength did not change significantly, though symptom severity decreased. Participants with denser networks at admission evidenced less change in ED symptomatology during treatment.
Conclusions
Findings suggest that symptoms related to shape and weight concerns and guilt are central ED symptoms, while physical symptoms, self-esteem, and feeling overwhelmed are links that may underlie comorbidities in EDs. Results provided some support for the validity of network approaches, in that admission networks conveyed prognostic information. However, the lack of correspondence between symptom reduction and change in network strength indicates that future research is needed to examine network dynamics in the context of intervention and relapse prevention.
This paper consisted of a running commentary by Ernest Hildner on the movie as it was shown. The data from the movie has not yet been fully analyzed and will be published elsewhere. Discussion immediately followed the movie. (ed.)
Research into the gut microbiota of human infants is necessary in order to better understand how inter-species interactions and ecological succession shape the diversity of the gut microbiota, and in turn, how the specific composition of the gut microbiota impacts on host health both during infancy and in later years. Blastocystis is a ubiquitous intestinal protist that has been linked to a number of intestinal and extra-intestinal diseases. However, emerging data show that asymptomatic carriage is common and that Blastocystis is prevalent in the healthy adult gut microbiota. Nonetheless, little is known about the prevalence and diversity of this microorganism in the healthy infant gut, including when and how individuals become colonized by Blastocystis. Here, we surveyed the prevalence and diversity of Blastocystis in an infant population (n = 59) from an industrialized country (Ireland) using Blastocystis-specific primers at three or more time-points up to 24 months old. Only three infants were positive for Blastocystis (prevalence = 5%) and this was only noted for samples collected at month 24. This rate is comparatively low relative to previously reported prevalence rates in the contemporaneous adult population. These data suggest that infants in Westernized countries that are successfully colonized by Blastocystis most likely acquire this microorganism via horizontal transfer.
Within aquatic habitats, the hyper-abundant Order Crustacea appear to be the predominant host group for members of the Phylum Microsporidia. The musculature, a common site of infection, provides access to biochemical (carbohydrate-rich) and physiological (mitochondria-rich) conditions conducive to prolific parasite replication and maturation. The significant proportion of body plan devoted to skeletal musculature in Crustacea provides the location for a highly efficient intracellular parasite factory. In this study, we utilize histological, ultrastructural and phylogenetic evidence to describe a previously known (Inodosporus octospora) and novel (Ovipleistophora arlo n. sp.) microsporidian parasites infecting the musculature of the common prawn (Palaemon serratus) from the same site, at the same time of year. Despite similar clinical signs of infection, both parasites are otherwise distinct in terms of pathogenesis, morphology and phylogeny. Based upon partial subunit ribosomal RNA (SSU rDNA) sequence, we show that that I. octospora may be identical to a Kabatana sp. previously described infecting two-spot goby (Gobiusculus flavescens) in Europe, or at least that Inodosporus and Kabatana genera are synonyms. In addition, SSU rDNA sequence for O. arlo places it within a distinct clade containing Ovipleistophora mirandellae and Ovipleistophora ovariae, both infecting the oocytes of freshwater fish in Europe. Taken together, our data provide strong evidence for trophic-transfer between crustacean and fish hosts for two different microsporidians within clade 5 of the phylum. Furthermore, it demonstrates that morphologically and phylogenetically distinct microsporidians can infect the same tissues of the same host species to impart clinical signs which mimic infection with the other.
The mechanics of snow friction are central to competitive skiing, safe winter driving and efficient polar sleds. For nearly 80 years, prevailing theory has postulated that self-lubrication accounts for low kinetic friction on snow: dry-contact sliding warms snow grains to the melting point, and further sliding produces meltwater layers that lubricate the interface. We sought to verify that self-lubrication occurs at the grain scale and to quantify the evolution of real contact area to aid modeling. We used high-resolution (15 µm) infrared thermography to observe the warming of stationary snow under a rotating polyethylene slider. Surprisingly, we did not observe melting at contacting snow grains despite low friction values. In some cases, slider shear failed inter-granular bonds and produced widespread snow movement with no persistent contacts to melt (μ < 0.03). When the snow grains did not move and persistent contacts evolved, the slider abraded rather than melted the grains at low resistance (μ < 0.05). Optical microscopy revealed that the abraded particles deposited in air pockets between grains and thereby carried heat away from the interface, a process not included in current models. Overall, our results challenge whether self-lubrication is indeed the dominant mechanism underlying low snow kinetic friction.