Corticosteroid-induced hyperammonaemic encephalopathy in a woman with late-onset ornithine transcarbamylase deficiency.

Ornithine transcarbamylase deficiency (OTCD) is a rare, X linked disorder that can manifest in late adulthood in heterozygous females as severe hyperammonaemia following environmental stressors. We present a case of hyperammonaemic encephalopathy that was triggered by glucocorticoid administration in an adult woman with heterozygous OTCD with clinical response to haemodialysis, ammonia scavengers and a high-calorie, low-protein diet.

Steerable Ureteroscopic Renal Evacuation (SURE) for Large Renal Stones: A Multi-Institutional Center Study.

BACKGROUND: The results of a recent pilot study suggest that steerable ureteroscopic renal evacuation (SURE) is safe and more effective in stone removal than basketing following laser lithotripsy. The objective of this retrospective study was to further assess the safety and efficacy of SURE using the CVAC® Aspiration System (Calyxo, Inc., Pleasanton, CA) in patients with large stone burdens. MATERIALS AND METHODS: Patients with a baseline stone burden of ≥10 mm who underwent SURE were identified. Subject demographics, secondary procedures, complications, and stone clearance (defined as percent baseline volume reduction) were evaluated. Sub-analyses were performed to explore patients identified as high-risk for percutaneous nephrolithotomy (PCNL) because 1) they were on anticoagulation or antiplatelet therapy at the time of procedure, or 2) they had limited mobility due to neurological conditions. RESULTS: Identified patients (N=43) had a mean pre-operative stone burden of 29±12 mm and mean stone volume of 3,092±5,002 mm3. Approximately one-half of patients (n=24, 55.8%) had computerized tomography (CT) imaging at follow-up, and of those, eight (33.3%) had no residual stones, 22 (91.7%) had >90% stone clearance, 23 (95.8%) had >80% stone clearance and 24 (100%) had >60% stone clearance. Stone clearance based on baseline stone burden varied between 93.8% and 98.9%. At baseline, 21 patients were anticipated to require staged ureteroscopy; however, only two of those (9.5%) needed secondary procedures. High-risk patients (n=22) were on anticoagulation or antiplatelet therapy (n=12) or had neurologic conditions (n=10). Stone clearance was 97% among patients in the anticoagulated cohort with postoperative CT imaging, and 83% in patients with neurologic conditions. There were no device-related complications and no post-operative admissions. CONCLUSIONS: The CVAC® Aspiration System is safe and effective for treating large stone burdens, including in high-risk patients, and may decrease the need for PCNL or secondary procedures.

Safer medicines To reduce falls and refractures for OsteoPorosis (#STOP): a study protocol for a randomised controlled trial of medical specialist-initiated pharmacist-led medication management reviews in primary care.

INTRODUCTION: Minimal trauma fractures (MTFs) often occur in older patients with osteoporosis and may be precipitated by falls risk-increasing drugs. One category of falls risk-increasing drugs of concern are those with sedative/anticholinergic properties. Collaborative medication management services such as Australia's Home Medicine Review (HMR) can reduce patients' intake of sedative/anticholinergics and improve continuity of care. This paper describes a protocol for an randomised controlled trial to determine the efficacy of an HMR service for patients who have sustained MTF. METHOD AND ANALYSIS: Eligible participants are as follows: ≥65 years of age, using ≥5 medicines including at least one falls risk-increasing drug, who have sustained an MTF and under treatment in one of eight Osteoporosis Refracture Prevention clinics in Australia. Consenting participants will be randomised to control (standard care) or intervention groups. For the intervention group, medical specialists will refer to a pharmacist for HMR focused on reducing falls risk predominately through making recommendations to reduce falls risk medicines, and adherence to antiosteoporosis medicines. Twelve months from treatment allocation, comparisons between groups will be made. The main outcome measure is participants' cumulative exposure to sedative and anticholinergics, using the Drug Burden Index. Secondary outcomes include medication adherence, emergency department visits, hospitalisations, falls and mortality. Economic evaluation will compare the intervention strategy with standard care. ETHICS AND DISSEMINATION: Approval was obtained via the New South Wales Research Ethics and Governance Information System (approval number: 2021/ETH12003) with site-specific approvals granted through Human Research Ethics Committees for each research site. Study outcomes will be published in peer-reviewed journals. It will provide robust insight into effectiveness of a pharmacist-based intervention on medicine-related falls risk for patients with osteoporosis. We anticipate that this study will take 2 years to fully accrue including follow-up. TRIAL REGISTRATION NUMBER: ACTRN12622000261718.

Immune checkpoint inhibitor lichenoid eruption due to pembrolizumab.

Pembrolizumab is an immune checkpoint inhibitor used in many cancer types, including genitourinary cancers. Although immunotherapies have dramatically changed the landscape of cancer treatment by providing an alternative to traditional chemotherapy, they have been associated with significant immune-related adverse events (IRAEs) with wide-ranging clinical manifestations. We present the case of an elderly woman on pembrolizumab for metastatic bladder cancer who developed cutaneous IRAE with lichenoid eruptions that responded to high-dose intravenous glucocorticoids.

A near-miss diagnosis of necrotizing breast fasciitis complicated by atrial fibrillation secondary to septic focus: a case report and brief review of literature.

Necrotizing fasciitis of the breast is a rare, life-threatening entity characterized by a rapidly aggressive infection of the soft tissue. There are few literature reports on necrotizing fasciitis at the level of the breast tissue as the most common locations are within the abdominal wall or extremities, but this entity can lead to sepsis and systemic multiorgan failure if not adequately managed. Here, we report a case that highlights the course of a 68-year-old African American female with a past medical history of hypertension, hyperlipidemia, and poorly controlled diabetes mellitus, who presented with the complaint of a painful right breast abscess with intermittent, purulent drainage. An initial point-of-care ultrasound displayed an area of induration of the right breast as well as soft tissue edema with no identifiable fluid collection. A subsequent CT abdomen and pelvis was obtained given new onset abdominal pain, which demonstrated incidental findings of inflammatory changes and subcutaneous emphysema along with colonic diverticulosis. Surgical intervention was immediately sought for which she underwent debridement and exploration of the right breast with findings that were consistent with necrotizing transformation. The patient was sent back to the OR for an additional surgical debridement the next day. Of note, the patient had post-op atrial fibrillation with rapid ventricular response and had to be admitted to the ICU for conversion to sinus rhythm. She returned to sinus rhythm and was transferred back to medicine before application of a negative pressure wound dressing on discharge. The patient was transitioned from Enoxaparin to Apixaban for anticoagulation control in the setting of atrial fibrillation before being discharged to a Skilled Nursing Facility with long-term antibiotics. This case highlights the difficulty and significance in establishing a prompt diagnosis for necrotizing fasciitis.

Uptake of pharmacist recommendations by patients after discharge: Implementation study of a patient-centered medicines review service.

BACKGROUND: Polypharmacy and potentially inappropriate medicine use is common in older people, resulting in harm increased by lack of patient-centred care. Hospital clinical pharmacy services may reduce such harm, particularly prevalent at transitions of care. An implementation program to achieve such services can be a complex long-term process. OBJECTIVES: To describe an implementation program and discuss its application in the development of a patient-centred discharge medicine review service; to assess service impact on older patients and their caregivers. METHOD: An implementation program was begun in 2006. To assess program effectiveness, 100 patients were recruited for follow-up after discharge from a private hospital between July 2019 and March 2020. There were no exclusion criteria other than age less than 65 years. Medicine review and education were provided for each patient/caregiver by a clinical pharmacist, including recommendations for future management, written in lay language. Patients were asked to consult their general practitioner to discuss those recommendations important to them. Patients were followed-up after discharge. RESULTS: Of 368 recommendations made, 351 (95%) were actioned by patients, resulting in 284 (77% of those actioned) being implemented, and 206 regularly taken medicines (19.7 % of all regular medicines) deprescribed. CONCLUSION: Implementation of a patient-centred medicine review discharge service resulted in patient-reported reduction in potentially inappropriate medicine use and hospital funding of this service. This study was registered retrospectively on 12th July 2022 with the ISRCTN registry, ISRCTN21156862, https://www.isrctn.com/ISRCTN21156862 .

Laminectomy as treatment for abrupt neurological decline in acrodysostosis: A case report.

Background: Acrodysostosis (ACRO) is a rare disorder of peripheral bone development which can be either sporadic or inherited with mutations in the PRKAR1A or PDE4D genes. The resulting phenotypical characteristics are variable and overlap with other dysostosis conditions, making diagnosis difficult without genotyping. Vertebral malformations have been reported with ACRO resulting in slowly progressive spinal cord compression leading to radiculopathy or myelopathy. Case Description: A 19-year-old female diagnosed with ACRO presented with progressively worsening lower extremity paraparesis, sensory loss, and urinary retention; she was wheelchair-bound. A magnetic resonance imaging showed cord signal change at the T2/T3 levels with accompanying diffuse cord edema between T6-T8. Six months following a T2/T3 and T6/T7 laminectomy, the patient's symptoms improved, but she still required a wheelchair. Conclusion: Patients with ACRO should be regularly monitored for cord compression to allow for early surgical decompression to prevent long-term, devasting neurological compromise.

Deep Learning for Identification of Alcohol-Related Content on Social Media (Reddit and Twitter): Exploratory Analysis of Alcohol-Related Outcomes.

BACKGROUND: Many social media studies have explored the ability of thematic structures, such as hashtags and subreddits, to identify information related to a wide variety of mental health disorders. However, studies and models trained on specific themed communities are often difficult to apply to different social media platforms and related outcomes. A deep learning framework using thematic structures from Reddit and Twitter can have distinct advantages for studying alcohol abuse, particularly among the youth in the United States. OBJECTIVE: This study proposes a new deep learning pipeline that uses thematic structures to identify alcohol-related content across different platforms. We apply our method on Twitter to determine the association of the prevalence of alcohol-related tweets with alcohol-related outcomes reported from the National Institute of Alcoholism and Alcohol Abuse, Centers for Disease Control Behavioral Risk Factor Surveillance System, county health rankings, and the National Industry Classification System. METHODS: The Bidirectional Encoder Representations From Transformers neural network learned to classify 1,302,524 Reddit posts as either alcohol-related or control subreddits. The trained model identified 24 alcohol-related hashtags from an unlabeled data set of 843,769 random tweets. Querying alcohol-related hashtags identified 25,558,846 alcohol-related tweets, including 790,544 location-specific (geotagged) tweets. We calculated the correlation between the prevalence of alcohol-related tweets and alcohol-related outcomes, controlling for confounding effects of age, sex, income, education, and self-reported race, as recorded by the 2013-2018 American Community Survey. RESULTS: Significant associations were observed: between alcohol-hashtagged tweets and alcohol consumption (P=.01) and heavy drinking (P=.005) but not binge drinking (P=.37), self-reported at the metropolitan-micropolitan statistical area level; between alcohol-hashtagged tweets and self-reported excessive drinking behavior (P=.03) but not motor vehicle fatalities involving alcohol (P=.21); between alcohol-hashtagged tweets and the number of breweries (P<.001), wineries (P<.001), and beer, wine, and liquor stores (P<.001) but not drinking places (P=.23), per capita at the US county and county-equivalent level; and between alcohol-hashtagged tweets and all gallons of ethanol consumed (P<.001), as well as ethanol consumed from wine (P<.001) and liquor (P=.01) sources but not beer (P=.63), at the US state level. CONCLUSIONS: Here, we present a novel natural language processing pipeline developed using Reddit's alcohol-related subreddits that identify highly specific alcohol-related Twitter hashtags. The prevalence of identified hashtags contains interpretable information about alcohol consumption at both coarse (eg, US state) and fine-grained (eg, metropolitan-micropolitan statistical area level and county) geographical designations. This approach can expand research and deep learning interventions on alcohol abuse and other behavioral health outcomes.

Combining Different Docking Engines and Consensus Strategies to Design and Validate Optimized Virtual Screening Protocols for the SARS-CoV-2 3CL Protease.

The 3CL-Protease appears to be a very promising medicinal target to develop anti-SARS-CoV-2 agents. The availability of resolved structures allows structure-based computational approaches to be carried out even though the lack of known inhibitors prevents a proper validation of the performed simulations. The innovative idea of the study is to exploit known inhibitors of SARS-CoV 3CL-Pro as a training set to perform and validate multiple virtual screening campaigns. Docking simulations using four different programs (Fred, Glide, LiGen, and PLANTS) were performed investigating the role of both multiple binding modes (by binding space) and multiple isomers/states (by developing the corresponding isomeric space). The computed docking scores were used to develop consensus models, which allow an in-depth comparison of the resulting performances. On average, the reached performances revealed the different sensitivity to isomeric differences and multiple binding modes between the four docking engines. In detail, Glide and LiGen are the tools that best benefit from isomeric and binding space, respectively, while Fred is the most insensitive program. The obtained results emphasize the fruitful role of combining various docking tools to optimize the predictive performances. Taken together, the performed simulations allowed the rational development of highly performing virtual screening workflows, which could be further optimized by considering different 3CL-Pro structures and, more importantly, by including true SARS-CoV-2 3CL-Pro inhibitors (as learning set) when available.

Thermal heterogeneity, migration, and consequences for spawning potential of female bull trout in a river-reservoir system.

The likelihood that fish will initiate spawning, spawn successfully, or skip spawning in a given year is conditioned in part on availability of energy reserves. We evaluated the consequences of spatial heterogeneity in thermal conditions on the energy accumulation and spawning potential of migratory bull trout (Salvelinus confluentus) in a regulated river-reservoir system. Based on existing data, we identified a portfolio of thermal exposures and migratory patterns and then estimated their influence on energy reserves of female bull trout with a bioenergetics model. Spawning by females was assumed to be possible if postspawning energy reserves equaled or exceeded 4 kJ/g. Given this assumption, results suggested up to 70% of the simulated fish could spawn each year. Fish that moved seasonally between a cold river segment and a warmer reservoir downstream had a greater growth rate and higher propensity to spawn in a given year (range: 40%-70%) compared with fish that resided solely in the cold river segment (25%-40%). On average, fish that spawned lost 30% of their energy content relative to their prespawn energy. In contrast, fish that skipped spawning accumulated, on average, 16% energy gains that could be used toward future gamete production. Skipped spawning occurred when water temperatures were relatively low or high, and if upstream migration occurred relatively late (mid-July or later) or early (early-May or earlier). Overall, our modeling effort suggests the configuration of thermal exposures, and the ability of bull trout to exploit this spatially and temporally variable thermal conditions can strongly influence energy reserves and likelihood of successful spawning.

Magnitude and direction of stream-forest community interactions change with timescale.

Networks of direct and indirect biotic interactions underpin the complex dynamics and stability of ecological systems, yet experimental and theoretical studies often yield conflicting evidence regarding the direction (positive or negative) or magnitude of these interactions. We revisited pioneering data sets collected at the deciduous forested Horonai Stream and conducted ecosystem-level syntheses to demonstrate that the direction of direct and indirect interactions can change depending on the timescale of observation. Prior experimental studies showed that terrestrial prey that enter the stream from the adjacent forest caused positive indirect effects on aquatic invertebrates during summer by diverting fish consumption. Seasonal and annual estimates of secondary production and organic matter flows along food web pathways demonstrate that this seasonal input of terrestrial invertebrate prey increases production of certain fish species, reversing the indirect effect on aquatic invertebrates from positive at the seasonal timescale to negative at the annual timescale. Even though terrestrial invertebrate prey contributed 54% of the annual organic matter flux to fishes, primarily during summer, fish still consumed 98% of the aquatic invertebrate annual production, leading to top-down control that is not revealed in short-term experiments and demonstrating that aquatic prey may be a limiting resource for fishes. Changes in the direction or magnitude of interactions may be a key factor creating nonlinear or stabilizing feedbacks in complex systems, and these dynamics can be revealed by merging experimental and comparative approaches at different scales.

Cephalomedullary blade cut-ins: a poorly understood phenomenon.

OBJECTIVES: Proximal femoral nail antirotation (PFNA) cut-in is a unique phenomenon seen in pertrochanteric hip fractures treated with the PFNA. Cut-in refers to the superomedial migration of the proximal femoral blade into the femoral head and hip joint. We recognize that cut-in is a completely separate entity from the well-described cut-out failure. This study assesses relevant radiological and patient risks factors for cut-in. DESIGN: Retrospective multicenter study looking at patients with pertrochanteric hip fractures managed with the Synthes PFNA SETTING: Four tertiary hospitals over 7 years. PATIENTS: Patients with cut-ins were identified. OUTCOME MEASUREMENT: The radiological appearance of this mode of failure was assessed and compared to cut-outs. Patient demographics, fracture configuration, time to implant failure (cut-in), bone mineral density, tip-apex distance, neck-shaft angle and position of the tip of the helical blade in the femoral head were collected. RESULTS: There was a total of 1027 patients across 4 institutions with 23 patients with cut-in. Average neck-shaft angle was 133 degrees. 16 out of 19 patients had severe osteoporosis with BMD < - 2.5. 14 of 23 patients had poor placement of the blade. 13 of 23 had a tip-apex distance of more than 20 mm. CONCLUSION: We propose a standardized nomenclature of "cut-in" for the phenomenon of superomedial migration of the proximal femoral blade. An anatomical neck-shaft reduction, accurate blade placement and increased surveillance for patients with severe osteoporosis are required to reduce the incidence and morbidity of cut-in.

Manure and tillage use in remediation of eroded land and impacts on soil chemical properties.

Soil loss through wind and water erosion is an ongoing problem in semiarid regions. A thin layer of top soil loss over a hectare of cropland could be corresponding to tons of productive soil loss per hectare. The objectives of this study were to evaluate the influence of beef feedlot manure, tillage and legume grass mixtures on changes in soil quality and nutrient components. The study was initiated in 2006 on an eroded site near Akron, Colorado, on a Norka-Colby very-fine sandy loam (fine-silty, mixed, mesic, Aridic, Argiustolls). Tillage treatments were no-tillage, shallow tillage (sweeps operations with V-blade) and deep tillage (DT; moldboard plow operations). In one set of plots, DT was implemented biannually (DT-2); and in another set the DT was done once at the initiation of the experiment in 2006. Amendments consisted of beef manure and urea (46-0-0), N fertilizer. Both amendments were added at low and high rates. A control treatment, with no fertilizer or manure added, was included with no-tillage and shallow tillage only. Six years of manure addition and tillage significantly altered soil chemical properties compared with fertilizer and grass legume mixtures. Across all the tillage treatments, at the 0-30 cm depth, soil pH from 2006 to 2012, was reduced 1.8 fold with high-manure compared with high-fertilizer treatment. Soil EC, Na, and SAR increased by 2.7 fold while soil P increase by 3.5 fold with high-manure treatment compared with low-manure from 2006 to 2012 across all the tillage treatments at the surface 0-30 cm. Soil organic carbon associated with high-manure was 71% higher than low-manure and 230% higher than high-fertilizer treatments in the 0-60 cm depth. Similar patterns were observed with soil total N. Overall, manure amendments greatly improved the soil nutrient status on this eroded site. However, the legume grass mixtures showed little effect on improving soils chemical properties. The micronutrients supplied by manure improved the soil nutrient status compared with inorganic fertilizer, the grass, and the grass-legume treatments. We concluded that more than six years are needed to measure significant improvements in soil quality from specific treatments, specifically fertilizer, grasses, and grass-legume mixtures in such eroded crop land.

Incorporating food web dynamics into ecological restoration: a modeling approach for river ecosystems.

Restoration is frequently aimed at the recovery of target species, but also influences the larger food web in which these species participate. Effects of restoration on this broader network of organisms can influence target species both directly and indirectly via changes in energy flow through food webs. To help incorporate these complexities into river restoration planning, we constructed a model that links river food web dynamics to in-stream physical habitat and riparian vegetation conditions. We present an application of the model to the Methow River, Washington, USA, a location of on-going restoration aimed at recovering salmon. Three restoration strategies were simulated: riparian vegetation restoration, nutrient augmentation via salmon carcass addition, and side channel reconnection. We also added populations of nonnative aquatic snails and fish to the modeled food web to explore how changes in food web structure mediate responses to restoration. Simulations suggest that side channel reconnection may be a better strategy than carcass addition and vegetation planting for improving conditions for salmon in this river segment. However, modeled responses were strongly sensitive to changes in the structure of the food web. The addition of nonnative snails and fish modified pathways of energy through the food web, which negated restoration improvements. This finding illustrates that forecasting responses to restoration may require accounting for the structure of food webs, and that changes in this structure, as might be expected with the spread of invasive species, could compromise restoration outcomes. Unlike habitat-based approaches to restoration assessment that focus on the direct effects of physical habitat conditions on single species of interest, our approach dynamically links the success of target organisms to the success of competitors, predators, and prey. By elucidating the direct and indirect pathways by which restoration affects target species, dynamic food web models can improve restoration planning by fostering a deeper understanding of system connectedness and dynamics.

Pediatric Urinary Retention in the Emergency Department: A Concerning Symptom with Etiology Outside the Bladder.

BACKGROUND: Urinary retention in an otherwise healthy adolescent is a concerning symptom, in which etiology can range from an extracystic mass to central nervous system involvement (CNS). One possibility is acute disseminated encephalomyelitis (ADEM), a rare inflammatory autoimmune disease that affects the CNS via demyelination. The disease usually is preceded by an acute viral infection, and commonly presents with multifocal neurological deficits. The diagnosis for ADEM is made based on clinical presentation, correlating with findings characterized on magnetic resonance imaging (MRI) in the CNS. CASE REPORT: Our case involves a 16-year-old boy who presented to the Emergency Department (ED) with urinary retention. The patient was an otherwise healthy adolescent who was experiencing intermittent fevers for 1 week, and was found to be monospot positive when seen by his pediatrician. When presenting to the ED, the patient's primary complaint was urinary retention, which he experienced acutely in the middle of the night. Due to the suspicious nature of the patient's symptoms and history of present illness, the patient received a thorough workup including magnetic resonance imaging (MRI) of the patient's brain and spinal cord, which demonstrated findings consistent with ADEM. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: There is very little literature describing a case of ADEM in the ED where the primary manifesting symptom was urinary retention. In addition, it is important that clinicians address acute urinary retention in an otherwise healthy adolescent as a red flag, with the need to rule out concerning etiology.

Beyond crystal balls: crosscutting solutions in global health to prepare for an unpredictable future.

BACKGROUND: Efforts in global heath need to deal not only with current challenges, but also to anticipate new scenarios, which sometimes unfold at lightning speed. Predictive modeling is frequently used to assist planning, but outcomes depend heavily on a subset of critical assumptions, which are mostly hampered by our limited knowledge about the many factors, mechanisms and relationships that determine the dynamics of disease systems, by a lack of data to parameterize and validate models, and by uncertainties about future scenarios. DISCUSSION: We propose a shift from a focus on the prediction of individual disease patterns to the identification and mitigation of broader fragilities in public health systems. Modeling capabilities should be used to perform "stress tests" on how interrelated fragilities respond when faced with a range of possible or plausible threats of different nature and intensity. This system should be able to reveal crosscutting solutions with the potential to address not only one threat, but multiple areas of vulnerability to future health risks. Actionable knowledge not based on a narrow subset of threats and conditions can better guide policy, build societal resilience and ensure effective prevention in an uncertain world.

A comparison of corn (Zea mays L.) residue and its biochar on soil C and plant growth.

In order to properly determine the value of charring crop residues, the C use efficiency and effects on crop performance of biochar needs to be compared to the un-charred crop residues. In this study we compared the addition of corn stalks to soil, with equivalent additions of charred (300 °C and 500 °C) corn residues. Two experiments were conducted: a long term laboratory mineralization, and a growth chamber trial with proso millet plants. In the laboratory, we measured soil mineral N dynamics, C use efficiency, and soil organic matter (SOM) chemical changes via infrared spectroscopy. The 300 °C biochar decreased plant biomass relative to a nothing added control. The 500°C biochar had little to no effect on plant biomass. With incubation we measured lower soil NO3 content in the corn stalk treatment than in the biochar-amended soils, suggesting that the millet growth reduction in the stalk treatment was mainly driven by N limitation, whereas other factors contributed to the biomass yield reductions in the biochar treatments. Corn stalks had a C sequestration use efficiency of up to 0.26, but charring enhanced C sequestration to values that ranged from 0.64 to 1.0. Infrared spectroscopy of the soils as they mineralized showed that absorbance at 3400, 2925-2850, 1737 cm-1, and 1656 cm-1 decreased during the incubation and can be regarded as labile SOM, corn residue, or biochar bands. Absorbances near 1600, 1500-1420, and 1345 cm-1 represented the more refractory SOM moieties. Our results show that adding crop residue biochar to soil is a sound C sequestration technology compared to letting the crop residues decompose in the field. This is because the resistance to decomposition of the chars after soil amendment offsets any C losses during charring of the crop residues.