The effects of organic grass and grass-birdsfoot trefoil pastures on Jersey heifer development: Herbage characteristics affecting intake.

Low dietary energy and decreased intake of herbage have been attributed to the reduced performance of grazing dairy cattle. We hypothesized that grasses with inherently greater energy would interact in a complementary way with condensed tannins (CT) in birdsfoot trefoil to increase herbage intake by grazing dairy heifers. Eight pasture treatments comprising high-sugar perennial ryegrass (Lolium perenne L.), orchardgrass (Dactylis glomerata L.), meadow bromegrass (Bromus riparius Rehmann), and tall fescue [Schendonorus arundinaceus (Schreb.) Dumort] were established in Lewiston, Utah as monocultures and binary mixtures with birdsfoot trefoil (Lotus corniculatus L.; BFT). Pasture treatments were rotationally stocked by Jersey heifers for 105 d in 2017 and 2018, and herbage samples were collected pre- and postgrazing for each 7-d grazing period and analyzed for herbage mass, nutritive value, and apparent herbage intake. We observed differences among pasture treatments in herbage quantity and nutritive value, as well as differences in herbage intake by grazing Jersey heifers. On average, grass-BFT mixtures had greater herbage intake than grass monocultures, and every grass-BFT treatment individually had greater herbage intake than their respective grass monocultures. Using multivariate analyses, we determined that approximately 50% of the variation in herbage intake was due to nutritive and physical herbage characteristics, with the most explanatory being characteristics related to fiber and energy, followed by those related to the percent of BFT in the herbage. Grass monocultures exhibited a range of inherent dietary energy, but there was indication that an imbalance of energy to crude protein (e.g., protein deficient) reduced intake of grass monocultures. Moreover, there was some evidence of a complementary effect between increased dietary energy and CT; however, low CT levels made it impossible to determine the effect of CT on herbage intake per se. This study confirmed that chemical and physical characteristics inherent to different pasture species have a large effect on herbage intake by grazing cattle. Pastures planted to binary mixtures of nutritious grasses and birdsfoot trefoil increase herbage intake of temperate pastures by grazing Jersey heifers.

Heterogeneous Presentations of Pharyngoesophageal Diverticula Occurring after Cervical Spine Surgery.

Dysphagia after anterior cervical spine surgery (ACSS) may be secondary to pharyngoesophageal diverticulum. Our objectives are to (1) highlight the heterogeneity in clinical presentation, (2) discuss pathophysiology and management, and (3) present a comprehensive literature review of these diverticula. All patients undergoing pharyngoesophageal diverticulum repair between 2013 and 2019 were identified. Cases with ACSS history underwent detailed review of clinical presentation, assessment, and management. Literature review and analysis of all reported ACSS-associated pharyngoesophageal diverticula was performed. Two hundred forty-three cases of pharyngoesophageal diverticulum repair were performed during the study period; 13 cases were ACSS-associated. Four types of clinical presentation were identified: (Type A) Spinal hardware present, with videofluoroscopic evidence of exposed hardware; (Type B) Spinal hardware present, without videofluoroscopic evidence of exposed hardware; (Type C) Spinal hardware absent due to prior spinal hardware removal or ACSS performed without hardware; and (Type D) Concurrent esophago-esophageal fistula (EEF) present. All of our cases were evaluated using modified barium swallow study and esophagoscopy and definitively managed with endoscopic diverticulotomy. Literature review identified 21 cases of ACSS-associated pharyngoesophageal diverticulum repair from 18 publications. The majority of cases were identified using barium esophagram (N = 18, 86%) and managed with open diverticulectomy (N = 19, 90%). There were no reports of EEF. ACSS-associated pharyngoesophageal diverticulum must be evaluated with fluoroscopy and endoscopy, which determine presentation type. Presentation type guides management. Esophageal perforation requires hardware removal and perforation repair with flap placement. Endoscopic diverticulotomy was found essential to definitive management.Level of Evidence: 4.

Anosmia in COVID-19: Mechanisms and Significance.

The global pandemic of coronavirus disease 2019 (COVID-19) caused by SARS-CoV-2 remains a challenge for prevention due to asymptomatic or paucisymptomatic patients. Anecdotal and preliminary evidence from multiple institutions shows that these patients present with a sudden onset of anosmia without rhinitis. We aim to review the pathophysiology of anosmia related to viral upper respiratory infections and the prognostic implications. Current evidence suggests that SARS-CoV-2-related anosmia may be a new viral syndrome specific to COVID-19 and can be mediated by intranasal inoculation of SARS-CoV-2 into the olfactory neural circuitry. The clinical course of neuroinvasion of SARS-CoV-2 is yet unclear, however an extended follow up of these patients to assess for neurological sequelae including encephalitis, cerebrovascular accidents and long-term neurodegenerative risk may be indicated.

The flip side of speaking up: a new model to facilitate positive responses to speaking up in the operating theatre.

BACKGROUND: Speaking up is important for patient safety, but only if the concern raised is acknowledged and responded to appropriately. While the power to change the course of events rests with those in charge, research has focussed on supporting those in subordinate positions to speak up. We propose responsibility also rests with senior clinical staff to respond appropriately. We explored the perceptions of senior staff on being spoken up to in the operating theatre (OT), and factors moderating their response. METHODS: We undertook interviews and focus groups of fully qualified surgeons, anaesthetists, nurses, and anaesthetic technicians working in OTs across New Zealand. We used grounded theory to analyse and interpret the data. RESULTS: With data from 79 participants, we conceptualise three phases in the speaking up interaction: 1) the content of the speaker's message and the tone of delivery; 2) the message interpreted through the receiver's filters, including beliefs on personal fallibility and leadership, respect for the speaker, understanding the challenges of speaking up, and personal cultural and professional norms around communication; and 3) the receiver's subsequent response and its effects on the speaker, the observing OT staff, and patient care. CONCLUSIONS: The speaking up interaction can be high stakes for the whole OT team. The receiver response can strengthen team cohesion and function, or cause distress and tension. Our grounded theory uncovers multiple influences on this interaction, with potential for re-framing and optimising the speaker/receiver interaction to improve team function and patient safety.

Challenging gender stereotypes and advancing inclusive leadership in the operating theatre.

Modern healthcare is delivered by interprofessional teams, and good leadership of these teams is integral to safe patient care. Good leadership in the operating theatre has traditionally been considered as authoritative, confident and directive, and stereotypically associated with men. We argue that this may not be the best model for team-based patient care and promote the concept of inclusive leadership as a valid alternative. Inclusive leadership encourages all team members to contribute to decision-making, thus engendering more team cohesion, information sharing and speaking up, and ultimately enhancing team effectiveness. However, the relational behaviours associated with inclusive leadership are stereotypically associated with women and may not in fact be recognised as leadership. In this article we provide evidence on the advantages of inclusive leadership over authoritative leadership and explore gender stereotypes and obstacles that limit the recognition of inclusive leadership. We propose that operating teams rise above gender stereotypes of leadership. Inclusive leadership can elicit maximum performance of every team member, thus realising the full potential of interprofessional healthcare teams to provide the best care for patients.

Uptake of risk-reducing surgery in BRCA gene carriers in Wales, UK.

Women who inherit a mutated copy of the BRCA gene have a higher lifetime risk of developing breast cancer. No large epidemiological studies exist looking at BRCA mutation carriers in UK populations. All patients with BRCA1/BRCA2 mutation identified between 1995 and 2015 were included. Individuals were identified from a prospectively gathered data base. Genetics case-notes were obtained and retrospective analysis performed. 581 female BRCA mutation carriers were identified with a median age of 34 (18-81) at the time of testing. Of the 301 women who underwent diagnostic testing (symptomatic) 246 had been diagnosed with breast cancer, 89 with ovarian cancer and 37 had both at time of testing. Median age at diagnostic test was 51 (25-81). 33% of women underwent risk-reducing mastectomies (RRM); median age at surgery 45. This compares with 37% of women in this diagnostic group who underwent Risk-reducing bilateral salpingo-oopherectomies (RRBSO) at a median age of 46. Two hundred and eighty women underwent predictive testing (family history, asymptomatic), median age 36 (18-81). 34% of women in this predictive group underwent RRM, median age 37. There was a 29% uptake of RRBSO (median age 44 years). Fifteen women (5%) developed breast cancer after being tested; none of these had undergone RRS. This unique study of all BRCA mutation carriers in Wales shows considerable variation in uptake of RRS. The decision to undergo RRS is complex and involves a number of factors, including a woman's age and life stage. As BRCA testing becomes more frequent and more gene mutation carriers are identified there will be significant implications for service allocation, screening demands, and provision of risk-reducing surgery for this high-risk patient group.

Clinical Benefit in Response to Palbociclib Treatment in Refractory Uterine Leiomyosarcomas with a Common CDKN2A Alteration.

BACKGROUND: Uterine leiomyosarcoma (uLMS) responds poorly to conventional chemotherapeutic agents, and personalized therapies have yet to be systematically explored. Comprehensive genomic profiling (CGP) can identify therapeutic targets and provide insight into the biology of this highly aggressive tumor. We report a case of uLMS treated with the CGP-matched therapy palbociclib, a CDK4/6 inhibitor, with sustained clinical benefit in this rare and deadly malignancy. MATERIALS AND METHODS: This study analyzed 279 clinically advanced/recurrent uLMS samples. Median patient age was 54 years (range, 23-83 years). DNA was extracted from 40 µm of formalin-fixed, paraffin-embedded sections, and CGP was performed on hybridization-captured, adaptor ligation-based libraries for up to 405 cancer-related genes plus introns from up to 31 genes frequently rearranged in cancer. Sequencing data were analyzed for base pair substitutions, insertions/deletions, copy number alterations, and rearrangements. RESULTS: CGP shows that 97.1% of uLMS harbor at least one alteration, and approximately 57% harbor alterations in one or more therapeutically targetable pathways. CDKN2A mutations that inactivate p16INK4a were identified in 11% of uLMS. We report the first demonstration of clinical benefit in response to palbociclib treatment for a uLMS patient with a CDKN2A mutation, resulting in disease stabilization and significant symptom reduction. CONCLUSION: A patient with uLMS harboring a CDKN2A mutation experienced clinical benefit from treatment with palbociclib, and genomic analysis of 279 uLMS samples revealed that 19% of patients had mutations affecting the cyclin-dependent kinase (CDK) pathway. These observations provide a rationale for a clinical trial investigating treatment with CDK pathway inhibitors for uLMS harboring relevant genomic alterations. The Oncologist 2017;22:416-421Implications for Practice: Comprehensive genomic profiling (CGP) of individuals with uterine leiomyosarcoma (uLMS) indicates that nearly 20% of patients may harbor a mutation affecting the cyclin-dependent kinase (CDK) pathway. The case presented demonstrates that a CDK inhibitory drug may provide clinical benefit to such individuals. Given the lack of curative therapies for uLMS, CGP could be performed on all cases of advanced uLMS and a CDK inhibitor could be recommended (preferably as part of a clinical trial) for individuals harboring a mutation in the CDK pathway.

Biaxial mechanical properties of human vocal fold cover under vocal fold elongation.

Mechanical properties of the human vocal fold cover layer were experimentally investigated in uniaxial and biaxial tensile tests. The results showed a coupling effect between the stress conditions along the anterior-posterior and transverse directions, with vocal fold elongation increasing vocal fold stiffness along both directions, thus allowing more efficient control of the fundamental frequency of voice through vocal fold elongation. This study also shows that vocal folds were nearly isotropic at resting conditions, thus a tendency to vibrate with incomplete glottal closure, but became increasingly anisotropic with increasing vocal fold elongation.

The influence of corticosteroid treatment on the outcome of influenza A(H1N1pdm09)-related critical illness.

BACKGROUND: Patients with 2009 pandemic influenza A(H1N1pdm09)-related critical illness were frequently treated with systemic corticosteroids. While observational studies have reported significant corticosteroid-associated mortality after adjusting for baseline differences in patients treated with corticosteroids or not, corticosteroids have remained a common treatment in subsequent influenza outbreaks, including avian influenza A(H7N9). Our objective was to describe the use of corticosteroids in these patients and investigate predictors of steroid prescription and clinical outcomes, adjusting for both baseline and time-dependent factors. METHODS: In an observational cohort study of adults with H1N1pdm09-related critical illness from 51 Canadian ICUs, we investigated predictors of steroid administration and outcomes of patients who received and those who did not receive corticosteroids. We adjusted for potential baseline confounding using multivariate logistic regression and propensity score analysis and adjusted for potential time-dependent confounding using marginal structural models. RESULTS: Among 607 patients, corticosteroids were administered to 280 patients (46.1%) at a median daily dose of 227 (interquartile range, 154-443) mg of hydrocortisone equivalents for a median of 7.0 (4.0-13.0) days. Compared with patients who did not receive corticosteroids, patients who received corticosteroids had higher hospital crude mortality (25.5% vs 16.4%, p = 0.007) and fewer ventilator-free days at 28 days (12.5 ± 10.7 vs 15.7 ± 10.1, p < 0.001). The odds ratio association between corticosteroid use and hospital mortality decreased from 1.85 (95% confidence interval 1.12-3.04, p = 0.02) with multivariate logistic regression, to 1.71 (1.05-2.78, p = 0.03) after adjustment for propensity score to receive corticosteroids, to 1.52 (0.90-2.58, p = 0.12) after case-matching on propensity score, and to 0.96 (0.28-3.28, p = 0.95) using marginal structural modeling to adjust for time-dependent between-group differences. CONCLUSIONS: Corticosteroids were commonly prescribed for H1N1pdm09-related critical illness. Adjusting for only baseline between-group differences suggested a significant increased risk of death associated with corticosteroids. However, after adjusting for time-dependent differences, we found no significant association between corticosteroids and mortality. These findings highlight the challenges and importance in adjusting for baseline and time-dependent confounders when estimating clinical effects of treatments using observational studies.

Genetic and functional studies implicate synaptic overgrowth and ring gland cAMP/PKA signaling defects in the Drosophila melanogaster neurofibromatosis-1 growth deficiency.

Neurofibromatosis type 1 (NF1), a genetic disease that affects 1 in 3,000, is caused by loss of a large evolutionary conserved protein that serves as a GTPase Activating Protein (GAP) for Ras. Among Drosophila melanogaster Nf1 (dNf1) null mutant phenotypes, learning/memory deficits and reduced overall growth resemble human NF1 symptoms. These and other dNf1 defects are relatively insensitive to manipulations that reduce Ras signaling strength but are suppressed by increasing signaling through the 3'-5' cyclic adenosine monophosphate (cAMP) dependent Protein Kinase A (PKA) pathway, or phenocopied by inhibiting this pathway. However, whether dNf1 affects cAMP/PKA signaling directly or indirectly remains controversial. To shed light on this issue we screened 486 1(st) and 2(nd) chromosome deficiencies that uncover >80% of annotated genes for dominant modifiers of the dNf1 pupal size defect, identifying responsible genes in crosses with mutant alleles or by tissue-specific RNA interference (RNAi) knockdown. Validating the screen, identified suppressors include the previously implicated dAlk tyrosine kinase, its activating ligand jelly belly (jeb), two other genes involved in Ras/ERK signal transduction and several involved in cAMP/PKA signaling. Novel modifiers that implicate synaptic defects in the dNf1 growth deficiency include the intersectin-related synaptic scaffold protein Dap160 and the cholecystokinin receptor-related CCKLR-17D1 drosulfakinin receptor. Providing mechanistic clues, we show that dAlk, jeb and CCKLR-17D1 are among mutants that also suppress a recently identified dNf1 neuromuscular junction (NMJ) overgrowth phenotype and that manipulations that increase cAMP/PKA signaling in adipokinetic hormone (AKH)-producing cells at the base of the neuroendocrine ring gland restore the dNf1 growth deficiency. Finally, supporting our previous contention that ALK might be a therapeutic target in NF1, we report that human ALK is expressed in cells that give rise to NF1 tumors and that NF1 regulated ALK/RAS/ERK signaling appears conserved in man.

Color Vision and the Railways: Part 1. The Railway LED Lantern Test.

PURPOSE: Lantern tests and practical tests are often used in the assessment of prospective railway employees. The lantern tests rarely embody the actual colors used in signaling on the railways. Practical tests have a number of problems, most notably consistency of application and practicability. This work was carried out to provide the Railway LED Lantern Test (RLLT) as a validated method of assessing the color vision of railway workers. METHODS: The RLLT, a simulated practical test using the same LEDs (light-emitting diodes) as are used in modern railway signals, was developed. It was tested on 46 color vision-normal (CVN) and 37 color vision-deficient (CVD) subjects. A modified prototype was then tested on 106 CVN subjects. RESULTS: All 106 CVN subjects and most mildly affected CVD subjects passed the modified lantern at 3 m. At 6 m, 1 of the 106 normal color vision subjects failed by missing a single red light. All the CVD subjects failed. The RLLT carried out at 3 m allowed mildly affected CVD subjects to pass and demonstrate adequate color vision for the less demanding railway tasks. Carried out at 6 m, it essentially reinforced normal color vision as the standard. CONCLUSIONS: The RLLT is a simply administered test that has a direct link to the actual visual task of the rail worker. The RLLT lantern has been adopted as an approved test in the Australian National Standard for Health Assessment of Rail Safety Workers in place of a practical test. It has the potential to be a valid part of any railway color vision standard.

Color Vision and the Railways: Part 2. Comparison of the CN Lantern Used on the Canadian Railways and Railway LED Lantern Tests.

PURPOSE: There are two currently available lantern tests that have their design based solely on the practices of the rail industry. These are the CN Lantern (CNLAN) used on the Canadian Railways and the Railway LED Lantern Tests (RLLT). In the same way that the signaling practices differ in the two jurisdictions, the design of the lanterns also differ. The CIE (Commission Internationale de l'Éclairage)-recommended color vision standards for transport predate both lanterns. The study was undertaken to assess the appropriateness of these lanterns in CIE Color Vision Standard 1. CIE Standard 1 is called "Normal color vision" but some very mild anomalous trichromats may pass the specified "lantern test that presents a high level of difficulty." METHODS: The lantern tests were undertaken by 46 color vision-normal and 37 color vision-deficient subjects. RESULTS: Subjects made more errors on the RLLT, and the pattern of errors is different, partly because there are blank presentations in the RLLT and "no light" is an acceptable response. The two lanterns showed agreement on the pass/fail categorization of 73 of the 83 subjects. The RLLT fails more color vision-normal subjects. CONCLUSIONS: Despite the different construction principles, the RLLT and CNLAN have pass/fail levels that are comparable with the Holmes-Wright Type B lantern, which is nominated in CIE Color Vision Standard 1 but is no longer commercially available. The higher failure rate of color vision-normal subjects on the RLLT has been addressed by changing the intensities of the two darkest red lights.

Color Vision and the Railways: Part 3. Comparison of FaLant, OPTEC 900, and Railway LED Lantern Tests.

PURPOSE: The Farnsworth Lantern (FaLant) and the OPTEC 900 are nominated in the Commission Internationale de l'Éclairage (CIE) Color Vision Standard 2. Neither test uses the railway signal color code of red, yellow, and green, and only the OPTEC 900 is commercially available. The Railway LED Lantern Test (RLLT) is based on railway signaling practices in New South Wales, Australia, and is nominated in the Australian railway medical standard. The objective of this study is to compare the performance of the three lantern tests. METHODS: The RLLT, FaLant, and OPTEC 900 were administered to 46 color vision-normal and 37 color vision-deficient (CVD) subjects. RESULTS: The pattern of errors on the RLLT was different from that of the FaLant and OPTEC 900. This may be accounted for, at least in part, by the different colors and the use of blank presentations in the RLLT. The three lanterns showed agreement in failing 21 and passing 6 of the CVD subjects (72.9%). The lanterns gave different results for 10 CVD subjects (27.9%): n = 5 passed only the RLLT and n = 3 passed only the FaLant; n = 1 failed only the FaLant and n = 1 failed only the RLLT. The overall failure rate by CVD for each lantern was 67.6% (RLLT), 73.0% (FaLant), and 78.4% (OPTEC 900). CONCLUSIONS: Despite the different construction principles, the pass/fail levels of the RLLT, FaLant, and OPTEC 900 are comparable and consistent with the performance of other lanterns listed by the CIE for Color Vision Standard 2. The RLLT may be a little easier to pass and is based on the signal color code used and actual signaling practice. We propose that the RLLT is also an appropriate lantern for CIE Color Vision Standard 2.

Laryngotracheal stenosis as a complication of photodynamic therapy.

OBJECTIVE: Photodynamic therapy (PDT) has been proposed as an effective treatment for mucosal carcinomas such as early-stage laryngeal squamous cell carcinoma. Its advantage over other conventional modalities (surgery and chemoradiation) lies in its ability to treat disease while preserving the function and structure of the larynx. While not FDA-approved in the United States, it is used in some countries as a treatment for laryngeal cancer and is an area of active investigation. This report documents a severe complication of tracheostomy-dependent laryngotracheal stenosis resulting from PDT. METHODS: Methods include a case report and review of the literature. RESULTS: A 65-year-old male presented with severe stenosis of the supraglottic, glottic, and subglottic larynx following successful treatment of his laryngeal carcinoma with PDT. His presentation, staged airway reconstruction, and outcome are detailed. CONCLUSION: PDT is a minimally invasive technique which in early clinical trials has matched the effectiveness of conventional therapies for treating early head and neck squamous cell cancers. It uses a photosensitizing agent that is retained by tumor cells, allowing for the selective destruction of neoplastic cells. Permanent sequelae following treatment have rarely been reported; the most commonly described adverse effects include pain, hoarseness, and phototoxicity. However, our case report discusses the potential for significant laryngotracheal stenosis requiring airway reconstruction following PDT.

A comparative study of cricotracheal resection and staged laryngotracheoplasty for adult subglottic stenosis.

OBJECTIVE: Cricotracheal resection (CTR) and laryngotracheoplasty (LTP) are open surgical treatments for severe subglottic stenosis. This study aims to compare the applications and outcomes of these techniques. METHOD: Patients with subglottic stenosis at a tertiary academic institution from 2000 to 2012 were identified by diagnosis codes. Patients who underwent LTP or CTR were included. Records were reviewed for treatment data and outcomes. Patients with a history of head and neck malignancy or stenosis without cricoid involvement were excluded. RESULT: Sixty-one and 20 patients underwent LTP and CTR, respectively. When comparing patients receiving LTP and CTR, there was a significant difference in stenosis etiology (P=.014). The groups were similar in Cotton-Myer grade (P=.102). At last follow-up, 80.3% of LTP patients and 90.0% of CTR patients were decannulated. On multivariate analysis, there was a significant association between stenosis grade and decannulation in the LTP group (P=.01). Decannulation was not associated with stenosis grade in the CTR group. In both groups, there was no significant association between decannulation and sex, stenosis etiology, or stenosis length. CONCLUSION: Cricotracheal resection and LTP have both shown excellent long-term decannulation rates. Etiology and stenosis grade are likely to be determining factors when recommending specific surgical interventions for subglottic stenosis.

Effects of vocal fold epithelium removal on vibration in an excised human larynx model.

This study investigated the impact of selective epithelial injury on phonation in an excised human larynx apparatus. With intact epithelium, the vocal folds exhibited a symmetrical vibration pattern with complete glottal closure during vibration. The epithelium was then enzymatically removed from one, then both vocal folds, which led to left-right asymmetric vibration and a decreased closed quotient. Although the mechanisms underlying these vibratory changes are unclear, these results demonstrate that some component of an intact surface layer may play an important role in achieving normal symmetric vibration and glottal closure.

Preservation of cranial nerves during removal of the brain for an enhanced student experience in neuroanatomy classes.

Neuroanatomy teaching at the University of Leeds includes the examination of isolated brains by students working in small groups. This requires the prosected brains to exhibit all 12 pairs of cranial nerves. Traditional methods of removing the brain from the skull involve elevating the frontal lobes and cutting each cranial nerve as the brain is reflected posteriorly. This can leave a substantial length of each nerve attached to the skull base rather than to the removed brain. We have found a posterior approach more successful. In this study, five adult heads were disarticulated at the level of the thyroid cartilage and placed, prone, in a head stand. A wedge of bone from the occipital region was removed before the cerebellum and brainstem were elevated to visualize the cranial nerves associated with the medulla oblongata, cerebellopontine angle and mesencephalic-pontine junction prior to cutting them as close to the skull as possible. Five brains were successfully removed from the skull, each having a full complement of cranial nerves of good length attached to them. This approach significantly increases the length and number of cranial nerves remaining attached to the brain, which supports student education. For integration into head and neck dissection courses, careful consideration will be required to ensure the necks are suitably dissected and to decide whether the cranial nerves are best left attached to the skull base or brain.

Understanding change in recycling and littering behavior across a school social network.

Understanding how communities change requires examining how individuals' beliefs and behaviors are shaped by those around them. This paper investigates behavior change across a large social network following a recycling intervention in a New Zealand high school community. We used a mixed methods design, combining focus group data with social network analysis from two waves of a questionnaire that measured friendship networks; recycling and littering behaviors; perceived behavioral norms; and teacher, friend, and parent encouragement for these behaviors. Recycling behavior increased significantly over the course of our study. Supporting the importance of social networks in this context, both littering and recycling behavior showed clear social clustering. Further, the degree of change in an individuals' littering and recycling behavior across time was predicted by friends' prior behavior. Focus group data provided insight into students' perceptions of social interactions and how these contributed to littering and recycling behavior.