Percutaneous Electrical Nerve Field Stimulation in Children and Adolescents With Functional Dyspepsia-Integrating a Behavioral Intervention.

OBJECTIVES: Functional dyspepsia (FD) includes postprandial distress and epigastric pain syndrome. Percutaneous electrical nerve field stimulation (PENFS) in addition to behavioral interventions (BI) has shown benefits in children with functional abdominal pain but not specifically in FD. We aimed to assess the efficacy of PENFS for treating FD and compare the outcomes with those who received the combination of PENFS + BI. MATERIALS AND METHODS: Charts of patients with FD who completed four weeks of PENFS were evaluated. A subset of patients received concurrent BI. Demographic data, medical history, and symptoms were documented. Outcomes at different time points included subjective symptom responses and validated questionnaires collected clinically (Abdominal Pain Index [API], Nausea Severity Scale [NSS], Functional Disability Inventory [FDI], Pittsburgh Sleep Quality Index [PSQI], Children's Somatic Symptoms Inventory [CSSI], Patient-Reported Outcomes Measurement Information Systems [PROMIS] Pediatric Anxiety and Depression scales). RESULT: Of 84 patients, 61% received PENFS + BI, and 39% received PENFS alone. In the entire cohort, API (p < 0.0001), NSS (p = 0.001), FDI (p = 0.001), CSSI (p < 0.0001), PSQI (p = 0.01), PROMIS anxiety (p = 0.02), and depression (p = 0.01) scores improved from baseline to three weeks and at three months. Subjective responses showed nausea improvement (p = 0.01) and a trend for improvement in abdominal pain (p = 0.07) at week three. Abdominal pain subjectively improved at week three and three months (p = 0.003 and 0.02, respectively), nausea at week three and three months (p = 0.01 and 0.04, respectively), and a trend for improvement in sleep disturbances at week three and three months (p = 0.08 and p = 0.07, respectively) in the PENFS + BI group vs PENFS alone. CONCLUSION: Abdominal pain, nausea, functioning, somatization, sleep disturbances, anxiety, and depression improved at three weeks and three months after PENFS in pediatric FD. Subjective pain and nausea improvement were greater in the PENFS + BI group than in the group with PENFS alone, suggesting an additive effect of psychologic therapy.

Blocking HIV-1 Infection by Chromosomal Integrative Expression of Human CD4 on the Surface of Lactobacillus acidophilus ATCC 4356.

Lactobacillus bacteria are potential delivery vehicles for biopharmaceutical molecules because they are well-recognized as safe microorganisms that naturally inhabit the human body. The goal of this study was to employ these lactobacilli to combat human immunodeficiency virus type 1 (HIV-1) infection and transmission. By using a chromosomal integration method, we engineered Lactobacillus acidophilus ATCC 4356 to display human CD4, the HIV-1 receptor, on the cell surface. Since human CD4 can bind to any infectious HIV-1 particles, the engineered lactobacilli can potentially capture HIV-1 of different subtypes and prevent infection. Our data demonstrate that the CD4-carrying bacteria are able to adsorb HIV-1 particles and reduce infection significantly in vitro and also block intrarectal HIV-1 infection in a humanized mouse model in preliminary tests in vivo Our results support the potential of this approach to decrease the efficiency of HIV-1 sexual transmission.IMPORTANCE In the absence of an effective vaccine, alternative approaches to block HIV-1 infection and transmission with commensal bacteria expressing antiviral proteins are being considered. This report provides a proof-of-concept by using Lactobacillus bacteria stably expressing the HIV-1 receptor CD4 to capture and neutralize HIV-1 in vitro and in a humanized mouse model. The stable expression of antiviral proteins, such as CD4, following genomic integration of the corresponding genes into this Lactobacillus strain may contribute to the prevention of HIV-1 sexual transmission.

Active Boulder Movement at High Martian Latitudes.

Lobate stony landforms occur on steep slopes at high latitudes on Mars. We demonstrate active boulder movement at seven such sites. Submeter-scale boulders frequently move distances of a few meters. The movement is concentrated in the vicinity of the lobate landforms but also occurs on other slopes. This provides evidence for a newly discovered, common style of activity on Mars, which may play an important role in slope degradation. It also opens the possibility that the lobate features are currently forming in the absence of significant volumes of liquid water.

Daily or intermittent budesonide in preschool children with recurrent wheezing.

BACKGROUND: Daily inhaled glucocorticoids are recommended for young children at risk for asthma exacerbations, as indicated by a positive value on the modified asthma predictive index (API) and an exacerbation in the preceding year, but concern remains about daily adherence and effects on growth. We compared daily therapy with intermittent therapy. METHODS: We studied 278 children between the ages of 12 and 53 months who had positive values on the modified API, recurrent wheezing episodes, and at least one exacerbation in the previous year but a low degree of impairment. Children were randomly assigned to receive a budesonide inhalation suspension for 1 year as either an intermittent high-dose regimen (1 mg twice daily for 7 days, starting early during a predefined respiratory tract illness) or a daily low-dose regimen (0.5 mg nightly) with corresponding placebos. The primary outcome was the frequency of exacerbations requiring oral glucocorticoid therapy. RESULTS: The daily regimen of budesonide did not differ significantly from the intermittent regimen with respect to the frequency of exacerbations, with a rate per patient-year for the daily regimen of 0.97 (95% confidence interval [CI], 0.76 to 1.22) versus a rate of 0.95 (95% CI, 0.75 to 1.20) for the intermittent regimen (relative rate in the intermittent-regimen group, 0.99; 95% CI, 0.71 to 1.35; P=0.60). There were also no significant between-group differences in several other measures of asthma severity, including the time to the first exacerbation, or adverse events. The mean exposure to budesonide was 104 mg less with the intermittent regimen than with the daily regimen. CONCLUSIONS: A daily low-dose regimen of budesonide was not superior to an intermittent high-dose regimen in reducing asthma exacerbations. Daily administration led to greater exposure to the drug at 1 year. (Funded by the National Heart, Lung, and Blood Institute and others; MIST ClinicalTrials.gov number, NCT00675584.).

Dietary docosahexaenoic acid supplementation in children with autism.

OBJECTIVE: The aim of the study was to determine whether docosahexaenoic acid (DHA) supplementation improves the behavior of children with autism. METHODS: A group of 3- to 10-year-old children with autism were randomized in a double-blind fashion to receive a supplement containing 200 mg of DHA or a placebo for 6 months. The parents and the investigator completed the Clinical Global Impressions-Improvement scale to rate changes in core symptoms of autism after 3 and 6 months. The parents completed the Child Development Inventory and the Aberrant Behavior Checklist, and both parents and teachers completed the Behavior Assessment Scale for Children (BASC) at enrollment and after 6 months. RESULTS: A total of 48 children (40 [83%] boys, mean age [standard deviation] 6.1 [2.0] years) were enrolled; 24 received DHA and 24 placebo. Despite a median 431% increase in total plasma DHA levels after 6 months, the DHA group was not rated as improved in core symptoms of autism compared to the placebo group on the CGI-I. Based on the analysis of covariance models adjusted for the baseline rating scores, parents (but not teachers) provided a higher average rating of social skills on the BASC for the children in the placebo group compared to the DHA group (P = 0.04), and teachers (but not parents) provided a higher average rating of functional communication on the BASC for the children in the DHA group compared to the placebo group (P = 0.02). CONCLUSIONS: Dietary DHA supplementation of 200 mg/day for 6 months does not improve the core symptoms of autism. Our results may have been limited by inadequate sample size.

Ground penetrating radar observations of the contact between the western delta and the crater floor of Jezero crater, Mars.

The delta deposits in Jezero crater contain sedimentary records of potentially habitable conditions on Mars. NASA's Perseverance rover is exploring the Jezero western delta with a suite of instruments that include the RIMFAX ground penetrating radar, which provides continuous subsurface images that probe up to 20 meters below the rover. As Perseverance traversed across the contact between the Jezero crater floor and the delta, RIMFAX detected a distinct discontinuity in the subsurface layer structure. Below the contact boundary are older crater floor units exhibiting discontinuous inclined layering. Above the contact boundary are younger basal delta units exhibiting regular horizontal layering. At one location, there is a clear unconformity between the crater floor and delta layers, which implies that the crater floor experienced a period of erosion before the deposition of the overlying delta strata. The regularity and horizontality of the basal delta sediments observed in the radar cross sections indicate that they were deposited in a low-energy lake environment.

Use of beclomethasone dipropionate as rescue treatment for children with mild persistent asthma (TREXA): a randomised, double-blind, placebo-controlled trial.

BACKGROUND: Daily inhaled corticosteroids are an effective treatment for mild persistent asthma, but some children have exacerbations even with good day-to-day control, and many discontinue treatment after becoming asymptomatic. We assessed the effectiveness of an inhaled corticosteroid (beclomethasone dipropionate) used as rescue treatment. METHODS: In this 44-week, randomised, double-blind, placebo-controlled trial we enrolled children and adolescents with mild persistent asthma aged 5-18 years from five clinical centres in the USA. A computer-generated randomisation sequence, stratified by clinical centre and age group, was used to randomly assign participants to one of four treatment groups: twice daily beclomethasone with beclomethasone plus albuterol as rescue (combined group); twice daily beclomethasone with placebo plus albuterol as rescue (daily beclomethasone group); twice daily placebo with beclomethasone plus albuterol as rescue (rescue beclomethasone group); and twice daily placebo with placebo plus albuterol as rescue (placebo group). Twice daily beclomethasone treatment was one puff of beclomethasone (40 µg per puff) or placebo given in the morning and evening. Rescue beclomethasone treatment was two puffs of beclomethasone or placebo for each two puffs of albuterol (180 µg) needed for symptom relief. The primary outcome was time to first exacerbation that required oral corticosteroids. A secondary outcome measured linear growth. Analysis was by intention to treat. This study is registered with clinicaltrials.gov, number NCT00394329. RESULTS: 843 children and adolescents were enrolled into this trial, of whom 288 were assigned to one of four treatment groups; combined (n=71), daily beclomethasone (n=72), rescue beclomethasone (n=71), and placebo (n=74)-555 individuals were excluded during the run-in, according to predefined criteria. Compared with the placebo group (49%, 95% CI 37-61), the frequency of exacerbations was lower in the daily (28%, 18-40, p=0·03), combined (31%, 21-43, p=0·07), and rescue (35%, 24-47, p=0·07) groups. Frequency of treatment failure was 23% (95% CI 14-43) in the placebo group, compared with 5·6% (1·6-14) in the combined (p=0·012), 2·8% (0-10) in the daily (p=0·009), and 8·5% (2-15) in the rescue (p=0·024) groups. Compared with the placebo group, linear growth was 1·1 cm (SD 0·3) less in the combined and daily arms (p<0·0001), but not the rescue group (p=0·26). Only two individuals had severe adverse events; one in the daily beclomethasone group had viral meningitis and one in the combined group had bronchitis. INTERPRETATION: Children with mild persistent asthma should not be treated with rescue albuterol alone and the most effective treatment to prevent exacerbations is daily inhaled corticosteroids. Inhaled corticosteroids as rescue medication with albuterol might be an effective step-down strategy for children with well controlled, mild asthma because it is more effective at reducing exacerbations than is use of rescue albuterol alone. Use of daily inhaled corticosteroid treatment and related side-effects such as growth impairment can therefore be avoided. FUNDING: National Heart, Lung and Blood Institute.

Test for Respiratory and Asthma Control in Kids (TRACK): clinically meaningful changes in score.

BACKGROUND: The Test for Respiratory and Asthma Control in Kids (TRACK) is the first validated questionnaire to assess respiratory and asthma control exclusively in young children. OBJECTIVE: We sought to determine the minimally important difference (MID) for interpreting meaningful changes in individual patients' TRACK scores. METHODS: In this prospective, nonrandomized, longitudinal study conducted at 20 US pediatric sites, TRACK was administered at 2 separate clinic visits (4-6 weeks apart) to caregivers of children aged less than 5 years with symptoms consistent with asthma. Anchor-based methods were used to determine the MID from mean score differences between patients based on multiple criteria measures: physician guidelines-based respiratory control rating, physician-recommended changes to therapy, episodes of symptoms lasting more than 24 hours in the past 3 months, oral corticosteroid use for respiratory tract illnesses in the past year, physician-assessed change in control status at follow-up, and caregiver-reported change in respiratory status. The MID also was determined from distribution-based methods. RESULTS: TRACK scores were assessed at baseline (426 caregivers) and follow-up (396 caregivers). Mean differences in TRACK scores between patients differing on criteria measures ranged from 3.4 to 16.4 points (mean, 11.1 points). Distribution-based techniques confirmed these findings. Based on logistic regression analyses, scoring 10 or more points less than 80 on TRACK was associated with an approximately 2-fold increased odds of having uncontrolled asthma or respiratory symptoms. CONCLUSION: Changes in TRACK scores of 10 or more points represent clinically meaningful changes in respiratory control status in individual young children with respiratory symptoms consistent with asthma and should alert health care providers to re-evaluate asthma management.

Ground penetrating radar observations of subsurface structures in the floor of Jezero crater, Mars.

The Radar Imager for Mars Subsurface Experiment instrument has conducted the first rover-mounted ground-penetrating radar survey of the Martian subsurface. A continuous radar image acquired over the Perseverance rover's initial ~3-kilometer traverse reveals electromagnetic properties and bedrock stratigraphy of the Jezero crater floor to depths of ~15 meters below the surface. The radar image reveals the presence of ubiquitous strongly reflecting layered sequences that dip downward at angles of up to 15 degrees from horizontal in directions normal to the curvilinear boundary of and away from the exposed section of the Séitah formation. The observed slopes, thicknesses, and internal morphology of the inclined stratigraphic sections can be interpreted either as magmatic layering formed in a differentiated igneous body or as sedimentary layering commonly formed in aqueous environments on Earth. The discovery of buried structures on the Jezero crater floor is potentially compatible with a history of igneous activity and a history of multiple aqueous episodes.

Test for respiratory and asthma control in kids (TRACK): a caregiver-completed questionnaire for preschool-aged children.

BACKGROUND: A validated questionnaire is needed to monitor respiratory control in preschool-aged children. OBJECTIVE: We sought to develop and validate a caregiver-completed questionnaire that measures respiratory control in young children. METHODS: A 33-item questionnaire that included asthma impairment and risk items was administered to 486 caregivers of children aged younger than 5 years with a current, recent, or past history of respiratory symptoms. Stepwise regression was used to select a subset of items with the greatest discriminant validity in relation to guidelines-defined asthma control in a random two-thirds development sample. Reliability, validity, and ability to screen for respiratory control problems were tested in development and validation samples (remaining one-third sample). RESULTS: The content of the 5 items selected, the Test for Respiratory and Asthma Control in Kids (TRACK), included frequency of respiratory symptoms (wheeze, cough, shortness of breath), activity limitation, and nighttime awakenings in the past 4 weeks; rescue medication use in the past 3 months; and oral corticosteroid use in the previous year. Reliability was greater than 0.70 in both samples. ANOVA showed that mean scores differed significantly (P < .001) in the expected direction across both samples for 3 levels of guidelines-based respiratory control, physician-recommended change in therapy, and symptom status. In the development and validation samples, screening analyses revealed areas under the receiver operating characteristic curve of 0.88 and 0.82, respectively; control status was correctly classified in 81% and 78% of cases. CONCLUSION: TRACK is a valid, easy-to-administer, caregiver-completed questionnaire of respiratory control in preschool-aged children with symptoms consistent with asthma.

Relationship between parenting stress and concerns identified by developmental screening and their effects on parental medical care-seeking behavior.

This cross-sectional study examines the relationship between parenting stress and concerns identified by developmental screening and their effects on parents' decisions to seek medical care for their children. A total of 182 parents completed both the Parenting Stress Index (PSI) and the Parents' Evaluation of Developmental Status (PEDS) when their children were admitted to a sick child care program that provides parents the option of requesting medical evaluations for their children with mild acute illnesses. Although 31.6% of parents (N = 62) requested medical evaluations, neither PSI nor PEDS scores were associated with these requests. However, PEDS scores indicating significant parental concerns about their child's development or behavior predicted clinically significant levels of parenting stress on the PSI (odds ratio 4.9; 95% confidence interval, 1.5-15.9; P = .007). Primary pediatric health care providers who routinely perform developmental screening need to consider this relationship when interpreting developmental screening results and offer supportive and referral services to families as needed.

Episodic use of an inhaled corticosteroid or leukotriene receptor antagonist in preschool children with moderate-to-severe intermittent wheezing.

BACKGROUND: Acute wheezing illnesses in preschoolers require better management strategies to reduce morbidity. OBJECTIVES: We sought to examine the effectiveness of episodic use of an inhaled corticosteroid and a leukotriene receptor antagonist in preschoolers with intermittent wheezing. METHODS: In a randomized, double-blind, placebo-controlled 12-month trial, 238 children aged 12 to 59 months with moderate-to-severe intermittent wheezing received 7 days of either budesonide inhalation suspension (1 mg twice daily), montelukast (4 mg daily), or placebo in addition to albuterol with each identified respiratory tract illness (RTI). Proportion of episode-free days (EFDs) during the 12-month trial was the primary outcome. RESULTS: The 3 treatment groups did not differ in proportions of EFDs, with adjusted mean EFDs of 76% (95% CI, 70% to 81%) for budesonide, 73% (95% CI, 66% to 79%) for montelukast, and 74% (95% CI, 65% to 81%) for conventional therapy (P = .66). The 3 groups did not differ in oral corticosteroid use, health care use, quality of life, or linear growth. However, during RTIs, budesonide and montelukast therapy led to modest reductions in trouble breathing (38% [P = .003] and 37% [P = .003], respectively) and interference with activity scores (32% [P = .01] and 40% [P = .001], respectively) that were most evident in those with positive asthma predictive indices. CONCLUSIONS: In preschool children with moderate-to-severe intermittent wheezing, episodic use of either budesonide or montelukast early in RTIs, when added to albuterol, did not increase the proportion of EFDs or decrease oral corticosteroid use over a 12-month period. However, indicators of severity of acute illnesses were reduced, particularly in children with positive asthma predictive indices.

Sublimation of terrestrial permafrost and the implications for ice-loss processes on Mars.

Sublimation of ice is rate-controlled by vapor transport away from its outer surface and may have generated landforms on Mars. In ice-cemented ground (permafrost), the lag of soil particles remaining after ice loss decreases subsequent sublimation. Varying soil-ice ratios lead to differential lag development. Here we report 52 years of sublimation measurements from a permafrost tunnel near Fairbanks, Alaska, and constrain models of sublimation, diffusion through porous soil, and lag formation. We derive the first long-term in situ effective diffusion coefficient of ice-free loess, a Mars analog soil, of 9.05 × 10-6 m2 s-1, ~5× larger than past theoretical studies. Exposed ice-wedge sublimation proceeds ~4× faster than predicted from analogy to heat loss by buoyant convection, a theory frequently employed in Mars studies. Our results can be used to map near-surface ice-content differences, identify surface processes controlling landform formation and morphology, and identify target landing sites for human exploration of Mars.

Can an Off-Nominal Landing by an MMRTG-Powered Spacecraft Induce a Special Region on Mars When No Ice Is Present?

This work aims at addressing whether a catastrophic failure of an entry, descent, and landing event of a Multimission Radioisotope Thermoelectric Generator-based lander could embed the heat sources into the martian subsurface and create a local environment that (1) would temporarily satisfy the conditions for a martian Special Region and (2) could establish a transport mechanism through which introduced terrestrial organisms could be mobilized to naturally occurring Special Regions elsewhere on Mars. Two models were run, a primary model by researchers at the Lawrence Berkeley National Laboratory and a secondary model by researchers at the Jet Propulsion Laboratory, both of which were based on selected starting conditions for various surface composition cases that establish the worst-case scenario, including geological data collected by the Mars Science Laboratory at Gale Crater. The summary outputs of both modeling efforts showed similar results: that the introduction of the modeled heat source could temporarily create the conditions established for a Special Region, but that there would be no transport mechanism by which an introduced terrestrial microbe, even if it was active during the temporarily induced Special Region conditions, could be transported to a naturally occurring Special Region of Mars.

Report of the Joint Workshop on Induced Special Regions.

The Joint Workshop on Induced Special Regions convened scientists and planetary protection experts to assess the potential of inducing special regions through lander or rover activity. An Induced Special Region is defined as a place where the presence of the spacecraft could induce water activity and temperature to be sufficiently high and persist for long enough to plausibly harbor life. The questions the workshop participants addressed were: (1) What is a safe stand-off distance, or formula to derive a safe distance, to a purported special region? (2) Questions about RTGs (Radioisotope Thermoelectric Generator), other heat sources, and their ability to induce special regions. (3) Is it possible to have an infected area on Mars that does not contaminate the rest of Mars? The workshop participants reached a general consensus addressing the posed questions, in summary: (1) While a spacecraft on the surface of Mars may not be able to explore a special region during the prime mission, the safe stand-off distance would decrease with time because the sterilizing environment, that is the martian surface would progressively clean the exposed surfaces. However, the analysis supporting such an exploration should ensure that the risk to exposing interior portions of the spacecraft (i.e., essentially unsterilized) to the martian surface is minimized. (2) An RTG at the surface of Mars would not create a Special Region but the short-term result depends on kinetics of melting, freezing, deliquescence, and desiccation. While a buried RTG could induce a Special Region, it would not pose a long-term contamination threat to Mars, with the possible exception of a migrating RTG in an icy deposit. (3) Induced Special Regions can allow microbial replication to occur (by definition), but such replication at the surface is unlikely to globally contaminate Mars. An induced subsurface Special Region would be isolated and microbial transport away from subsurface site is highly improbable.

Why parents seek medical evaluations for their children with mild acute illnesses.

The reasons underlying parents' decisions to seek medical evaluations for their mildly ill children are not well understood. This cross-sectional study tracked parents' requests for on-site medical evaluations at a sick child care program. A logistic regression model identified factors associated with parents' decisions to seek medical evaluations for their children based on the data from parent-completed questionnaires. A convenience sample of 196 parents completed all questionnaires; 62 (31.6%) parents sought medical evaluations. Parents were more likely to seek medical evaluations if they were concerned about missing work (odds ratio = 8.6; 95% confidence interval, 3.3-22.0; P = .0001), if they smoked (odds ratio = 3.7; 95% confidence interval, 1.1-12.4; P = .037), or if their spouse's highest educational attainment was some high school (odds ratio = 0.4; 95% confidence interval, 0.1-1.0; P = .044). The data highlight the problems working parents have in accessing health care during usual working hours and the potential value of convenient health care programs.

The effects of snow and salt on ice table stability in University Valley, Antarctica.

The Antarctic Dry Valleys represent a unique environment where it is possible to study dry permafrost overlaying an ice-rich permafrost. In this paper, two opposing mechanisms for ice table stability in University Valley are addressed: i) diffusive recharge via thin seasonal snow deposits andii) desiccation via salt deposits in the upper soil column. A high-resolution time-marching soil and snow model was constructed and applied to University Valley, driven by meteorological station atmospheric measurements. It was found that periodic thin surficial snow deposits (observed in University Valley) are capable of drastically slowing (if not completely eliminating) the underlying ice table ablation. The effects of NaCl, CaCl2 and perchlorate deposits were then modelled. Unlike the snow cover, however, the presence of salt in the soil surface (but no periodic snow) results in a slight increase in the ice table recession rate, due to the hygroscopic effects of salt sequestering vapour from the ice table below. Near-surface pore ice frequently forms when large amounts of salt are present in the soil due to the suppression of the saturation vapour pressure. Implications for Mars high latitudes are discussed.

The pH dependent reactions of graphene oxide with small molecule thiols.

Graphene oxide (GO) is a heterogenous 2D carbon-based material composed of sp2 and sp3 hybridized carbon atoms and oxygen containing functionalities, i.e., alcohols and epoxides. Thus, the chemical reactivity of GO is complex and both complimentary and contrasting to the reactivity of corresponding small molecules (e.g., tertiary alcohols, epoxides, and alkenes). Understanding the reactivity of GO under different conditions and with different reagents will ensure the chemical composition can be controlled and thus electronic and optical properties dictated, and solubility tuned for desired applications. Reaction of GO nanosheets towards a variety of reagents has been reported, however controlling the reaction pathway of GO nanosheets with a single nucleophile by simple alternation of the reaction medium has not been realized. This ability to tune the reaction by modification of solution pH, for example, would aid in understanding the reactivity of GO. Herein, we report that GO undergoes two distinct reaction pathways with ethane thiol depending on the pH of the reaction media: under aprotic basic conditions GO nanosheets undergo functionalization with minimal reduction, and under superacidic conditions GO nanosheets are reduced with no functionalization.

Exposed subsurface ice sheets in the Martian mid-latitudes.

Thick deposits cover broad regions of the Martian mid-latitudes with a smooth mantle; erosion in these regions creates scarps that expose the internal structure of the mantle. We investigated eight of these locations and found that they expose deposits of water ice that can be >100 meters thick, extending downward from depths as shallow as 1 to 2 meters below the surface. The scarps are actively retreating because of sublimation of the exposed water ice. The ice deposits likely originated as snowfall during Mars' high-obliquity periods and have now compacted into massive, fractured, and layered ice. We expect the vertical structure of Martian ice-rich deposits to preserve a record of ice deposition and past climate.