Radioactive seed localization is a safe and effective tool for breast cancer surgery: an evaluation of over 25,000 cases.

Radioactive seed localization (RSL) provides a precise and efficient method for removing non-palpable breast lesions. It has proven to be a valuable addition to breast surgery, improving perioperative logistics and patient satisfaction. This retrospective review examines the lessons learned from a high-volume cancer center's RSL program after 10 years of practice and over 25 000 cases. We provide an updated model for assessing the patient's radiation dose from RSL seed implantation and demonstrate the safety of RSL to staff members. Additionally, we emphasize the importance of various aspects of presurgical evaluation, surgical techniques, post-surgical management, and regulatory compliance for a successful RSL program. Notably, the program has reduced radiation exposure for patients and medical staff.

Impact of shield location on staff and caregiver dose rates for I-131 radiopharmaceutical therapy patients.

The goal of this study is to investigate the effect of the location and width of a single lead shield on the dose rate of staff and caregivers in a hospital room with an I-131 patient. The best orientation of the patient and caregiver relative to the shield was determined based on minimizing staff and caregiver radiation dose rates. Shielded and unshielded dose rates were simulated using a Monte Carlo computer simulation and validated using real-world ionisation chamber measurements. Based on a radiation transport analysis using an adult voxel phantom published by the International Commission on Radiological Protection, placing the shield near the caregiver yielded the lowest dose rates. However, this strategy reduced the dose rate in only a tiny area of the room. Furthermore, positioning the shield near the patient in the caudal direction provided a modest dose rate reduction while shielding a large room area. Finally, increased shield width was associated with decreasing dose rates, but only a four-fold dose-rate reduction was observed for standard width shields. The recommendations of this case study may be considered as potential candidate room configurations where radiation dose rates are minimized, however these findings must be weighed against additional clinical, safety, and comfort considerations.

TRAF3IP2-IL-17 Axis Strengthens the Gingival Defense against Pathogens.

Recent genome-wide association studies have suggested novel risk loci associated with periodontitis, which is initiated by dysbiosis in subgingival plaque and leads to destruction of teeth-supporting structures. One such genetic locus was the tumor necrosis factor receptor-associated factor 3 interacting protein 2 (TRAF3IP2), a gene encoding the gate-keeping interleukin (IL)-17 receptor adaptor. In this study, we first determined that carriers of the lead exonic variant rs13190932 within the TRAF3IP2 locus combined with a high plaque microbial burden was associated with more severe periodontitis than noncarriers. We then demonstrated that TRAF3IP2 is essential in the IL-17-mediated CCL2 and IL-8 chemokine production in primary gingival epithelial cells. Further analysis suggested that rs13190932 may serve a surrogate variant for a genuine loss-of-function variant rs33980500 within the same gene. Traf3ip2 null mice (Traf3ip2-/-) were more susceptible than wild-type (WT) mice to the Porphyromonas gingivalis-induced periodontal alveolar bone loss. Such bone loss was associated with a delayed P. gingivalis clearance and an attenuated neutrophil recruitment in the gingiva of Traf3ip2-/- mice. Transcriptomic data showed decreased expression of antimicrobial genes, including Lcn2, S100a8, and Defb1, in the Traf3ip2-/- mouse gingiva in comparison to WT mice prior to or upon P. gingivalis oral challenge. Further 16S ribosomal RNA sequencing analysis identified a distinct microbial community in the Traf3ip2-/- mouse oral plaque, which was featured by a reduced microbial diversity and an overabundance of Streptococcus genus bacteria. More P. gingivalis was observed in the Traf3ip2-/- mouse gingiva than WT control animals in a ligature-promoted P. gingivalis invasion model. In agreement, neutrophil depletion resulted in more local gingival tissue invasion by P. gingivalis. Thus, we identified a homeostatic IL-17-TRAF3IP2-neutrophil axis underpinning host defense against a keystone periodontal pathogen.

An investigation of blood, milk, and urine test patterns for the diagnosis of ketosis in dairy cows in early lactation.

Ketosis in dairy cattle is primarily diagnosed based on the concentrations of ketone bodies in the blood, milk, or urine. Cow-side tests using these fluids are available for rapid detection of elevated concentrations of ketone bodies. Although these tests have been extensively validated, the performance of different tests has not been compared over time. Our objectives were to investigate the relationship between point-of-care diagnostic tests measuring the concentrations of ß-hydroxybutyrate (BHB) in blood (BT; Precision Xtra, Abbott Laboratories), BHB in milk (MT; Keto-Test, Elanco), and acetoacetate (AcAc) in urine (UT; Ketostix, Bayer Corporation) through cases of ketosis. Holstein cows (n = 148) were screened daily for hyperketonemia (HYK; blood BHB ≥1.2 mmol/L) from 3 to 16 d in milk (DIM); moreover, milk and urine samples were collected concomitantly and tested for ketones (ketosis thresholds: 100 µmol/L milk BHB and 5 mg/dL urine AcAc). Of the animals screened (n = 148), 74% were diagnosed with HYK. When diagnosed with HYK, cows were treated with propylene glycol orally once daily for 5 d. After the day of diagnosis (d 0), hyperketonemic cows were retested with BT, MT, and UT for 3 d (d 1, 2, and 3). We assessed the diagnostic test performance and time to ketosis (survival analyses and Cox proportional hazards models) of MT and UT compared with BT. Considering all paired samples (before and after diagnosis of HYK), MT had 61% sensitivity and 91% specificity, whereas the UT had 77% sensitivity and 94% specificity compared with BT. The specificity of MT and UT increased from d 0 to d 1, decreased on d 2, and increased on d 3. The median time to diagnosis of ketosis in blood was 5 DIM (95% CI 5 to 7 DIM); moreover, MT and UT had 2 d greater median time to diagnosis of ketosis compared with the BT [7 DIM (6 to 11 d); and 7 DIM (6 to 13 d), respectively]. We concluded that the UT is a more sensitive predictor of blood BHB concentration than the MT. The UT and MT tests diagnosed ketotic cows approximately 2 d later than the BT. The possible consequences of delay in detection of ketosis in milk and urine should be investigated.

Reducing milking frequency from twice to once daily as an adjunct treatment for ketosis in lactating dairy cows-A randomized controlled trial.

This randomized controlled trial investigated the effects of temporarily reducing milking frequency (MF) on the resolution of ketosis and milk production in dairy cows in early lactation. To detect ketosis [blood ß-hydroxybutyrate (BHB) ≥1.2 mmol/L], Holstein cows were screened daily from 3 to 16 d in milk using a cow-side meter. Cows diagnosed with ketosis (n = 104) were randomly assigned to twice-daily milking (TDM) or reduced to once-daily milking (ODM) for 2 wk, then returned to twice-daily milking. Both treatment groups received a 5-d treatment of an oral propylene glycol drench (PG; 300 g) beginning on the afternoon of the diagnosis; cows received additional 5-d PG treatments if they had a ketotic test result (blood BHB ≥1.2 mmol/L) at least 4 d after finishing the first PG treatment. Blood BHB tests were conducted for the first 3 d after ketosis diagnosis, and then once every 3 d for 21 d of trial (DOT). Milk and milk component data were collected weekly for 15 wk following trial enrollment. The ODM group showed rapidly and markedly decreased blood BHB concentrations (primiparous cows: 1 DOT, 0.92 ODM vs. 1.22 TDM, 15 DOT, 0.55 vs. 0.81 mmol/L; multiparous cows: 1 DOT, 1.01 vs. 1.40, 15 DOT, 0.78 vs. 1.65 mmol/L). In addition, a logistic regression model indicated that ODM cows were less likely to have blood BHB concentrations ≥1.2 mmol/L [primiparous cows: 3 DOT: ODM 1% (95% confidence interval: 0-10%) vs. TDM 43% (30-58%), 15 DOT ODM 0% (0-0.2%) vs. TDM 22% (13-36%); multiparous cows: 3 DOT: ODM 33% (24-44%) vs. TDM 59% (48-69%), 15 DOT ODM 20.9% (13-31%) vs. TDM 64% (53-74%)]. The proportion of ODM cows that required additional treatments of PG were substantially lower than the TDM group (ODM: 39%; TDM: 64%) than the TDM cows during the initial 21-d period. However, during the 2-wk treatment period, cows in the ODM group produced 26% less milk and 25% less energy-corrected milk than the TDM cows. During wk 3 to 15, when all cows were milked twice daily, ODM cows produced less milk (-14%) and energy-corrected milk (-12%) compared with the TDM group. Milk protein percentage was greater, and milk fat percentage and linear score tended to be greater in the ODM group over 15 wk. In conclusion, a 2-wk reduction of MF in ketotic cows from twice to once daily with treatment with PG resolved ketosis and decreased blood BHB concentrations more effectively than treating TDM cows with PG alone. However, the 2-wk MF reduction had immediate and long-term (up to 13 wk after cessation of MF reduction) negative effects on milk production.

Achilles tendon rupture: what you need to know.

Heel pain and a history of a 'pop' or feeling 'something go' are the buzz phrases classically associated with Achilles tendon rupture. However, the diagnosis is often missed in clinical practice because of the assumption that this is a sporting injury suffered only by the young or middle-aged. In a sedentary older patient, the injury may be dismissed as an ankle sprain. If swelling is present but no injury is recalled then deep vein thrombosis is suspected, but Achilles rupture is not. The diagnosis of Achilles tendon rupture is clinical, based on history and examination. Radiological imaging (ultrasound scan) is useful to plan orthopaedic management and exclude concomitant deep vein thrombosis. In most cases, non-operative management with the ankle held plantar flexed in a boot is the current best practice.

Evidence of Small Airways Disease and the Immediate Effects of Lumacaftor/Ivacaftor in Children with Cystic Fibrosis.

Aim The aim of this study was to explore risk factors for acute changes in lung function following initiation of lumacaftor/ivacaftor (LUM/IVA) in children with cystic fibrosis. Methods Retrospective review of all children commenced on LUM/IVA treatment over a one-year period. CT Thorax images were reviewed for evidence of air trapping using the Brody score. Results Data was collected from 15 children. A transient decline in ppFEV1 was observed after initiation of LUM/IVA in 93% (n=14) of patients with an absolute mean decline of -10.8%. There was a statistically significant inverse relationship between ΔFEV1 and baseline ppFEV1. There was no relationship between air trapping score and ΔFEV1 (p=0.41). Conclusion Pre-existing small airways disease is not a risk factor for acute changes in lung function following initiation of LUM/IVA. Our results suggest that a LUM/IVA-related decline in lung function is more significant in CF children with higher baseline FEV1.

Epidemiology of UK Military Exercise SAIF SAREEA 3: future planning for hot climates.

INTRODUCTION: Epidemiological data captured from military exercises and operations can highlight treatment requirements specific to operating in certain environmental conditions. Such data is invaluable to enable accurate planning for future exercises. Epidemiological data were collected during Exercise SAIF SAREEA 3 (SS3) to provide an insight into medical provision requirements for low-tempo military operations in hot, desert climates. METHOD: Epidemiological data was collected from all consultations conducted during the exercise within the LAND Medical Reception Station, 24 August-14 November 2018, using Epi-NATO surveillance systems. RESULTS: Of the 1414 total consultations recorded, 759 were first presentations and 665 were follow-up consultations, with 35 referrals made to hospitals. 1348 days of limited duties were given and 258 working days were lost. The most common coding reported for consultations were 'non-battle non-sport related injuries', 'sport related injuries' and 'dermatological'. DISCUSSION: The data highlight the most common cause of injuries and the role of assets such as dental, sexual and mental health services for future deployments. A number of explanations are considered in relation to the patterns identified and the effect on future planning for working in hot climates. Furthermore, Exercise SS3 had reduced numbers of personnel requiring deployed Role 2 or host nation hospital services, which again raises further considerations for future deployments.

Medical data collection on UK Military Exercise Saif Sareea 3: the EpiNATO-2 surveillance system.

INTRODUCTION: Epidemiological data from military exercises are important to identify trends in medical presentations and treatment requirements to aid planning for future operations. UK Military exercises use the EpiNATO-2 surveillance system for this purpose, however it has some limitations in the spectrum of data it can collect. An enhanced reporting system titled EpiNATO-2 PLUS was developed and introduced in all LAND (Army) Role 1 Medical Treatment Facilities (MTFs) as part of Exercise Saif Sareea 3 (SS3). It was assessed as part of a Quality Improvement Project for its utility in terms of spectrum and validity of data capture. METHOD: Epidemiological data were collected over a 2-month period from medical consultations in Camp Shafa during SS3 by EpiNATO-2 or EpiNATO-2 PLUS. This involved categorisation of symptoms into a coding system which represents a spectrum of clinical presentations, as well as collecting data on the effect of medical issues on personnel productivity. Halfway through the collection period, an EpiNATO-2 PLUS education session and Summary Guide were introduced. Data were audited for the period before and after these introductions. RESULTS: Of the 1163 consultations conducted in the 2-month period, the use of EpiNATO-2 PLUS captured an additional 169 patient contacts not collected by EpiNATO-2. The provision of a summary guide and teaching session decreased coding errors in the second audit period from 12.9% to 6.8% for EpiNATO-2 and from 19.4% to 6.6% for EpiNATO-2 PLUS, respectively. CONCLUSIONS: The use of EpiNATO-2 PLUS collected a broader spectrum of medical activity in the Role 1 MTF, by capturing an additional 10% of the clinical workload compared with EpiNATO-2. The increase in coding accuracy correlates with the introduction of the education session and EpiNATO-2 PLUS Summary Guide. It is recommended that EpiNATO-2 PLUS is used in future deployments.

Mutations in the voltage-gated sodium channel gene associated with deltamethrin resistance in commercially sourced Phytoseiulus persimilis.

The implementation of Integrated Pest Management in current agricultural practice is a convenient and very effective strategy to keep pest populations under control. The use of biological control agents, such as Phytoseiulus persimilis, is key for the success of such an approach. This predatory mite is widely used as it is very effective for controlling Tetranychus urticae, one of the most devastating crop pests. Here, we identify several mutations located in the voltage-gated sodium channel (VGSC) of commercially sourced P. persimilis that correlate with a reduced susceptibility to the pyrethroid deltamethrin. We found that the mites sourced from two different biocontrol product companies have intrinsic genotypic differences that correlate with their phenotype when tested with different concentrations of deltamethrin. Mites from Syngenta Bioline, carrying the mutations M918L and A1536T, were able to survive deltamethrin concentrations of up to 10 ppm, while the mites from Koppert Biological Systems, with the combination M918L, L925V and S1539T, survived treatment with 40 ppm. All of the point mutations identified in the predatory mite samples are located in a particular region of the VGSC, previously proposed as the binding site for this family of pesticides and identified as a 'hot spot' for resistance.

Artificial Intelligence Tool for Optimizing Eligibility Screening for Clinical Trials in a Large Community Cancer Center.

PURPOSE: Less than 5% of patients with cancer enroll in clinical trials, and 1 in 5 trials are stopped for poor accrual. We evaluated an automated clinical trial matching system that uses natural language processing to extract patient and trial characteristics from unstructured sources and machine learning to match patients to clinical trials. PATIENTS AND METHODS: Medical records from 997 patients with breast cancer were assessed for trial eligibility at Highlands Oncology Group between May and August 2016. System and manual attribute extraction and eligibility determinations were compared using the percentage of agreement for 239 patients and 4 trials. Sensitivity and specificity of system-generated eligibility determinations were measured, and the time required for manual review and system-assisted eligibility determinations were compared. RESULTS: Agreement between system and manual attribute extraction ranged from 64.3% to 94.0%. Agreement between system and manual eligibility determinations was 81%-96%. System eligibility determinations demonstrated specificities between 76% and 99%, with sensitivities between 91% and 95% for 3 trials and 46.7% for the 4th. Manual eligibility screening of 90 patients for 3 trials took 110 minutes; system-assisted eligibility determinations of the same patients for the same trials required 24 minutes. CONCLUSION: In this study, the clinical trial matching system displayed a promising performance in screening patients with breast cancer for trial eligibility. System-assisted trial eligibility determinations were substantially faster than manual review, and the system reliably excluded ineligible patients for all trials and identified eligible patients for most trials.

The challenge of differentiating vaso-occlusive crises from osteomyelitis in children with sickle cell disease and bone pain: A 15-year retrospective review.

PURPOSE: The paediatric sickle cell disease (SCD) osteomyelitis (OM) incidence is 0.3% to 12%. Differentiating vaso-occlusive crises (VOC) from OM is a diagnostic challenge, with limited evidence guiding management. We present a 15-year review of a paediatric sickle cell cohort. We aim to identify OM incidence and provide a management protocol for these children presenting with bone pain. METHODS: A prospective database of children with haemoglobinopathies (2002 to 2017) was analyzed for temperature, C-reactive protein (CRP) and white cell count (WCC) on admission as well as imaging, treatment and cultures. OM diagnosis was supported by imaging and blood cultures. VOC was defined as bone pain that improved without antibiotics. RESULTS: Over 15 years, 96 children with SCD presented 358 times to hospital. Empirical antibiotics were given in 308 presentations. There were five cases of OM (1.4%); two acute and three chronic. In all, 50 presentations of VOC were identified. No significant differences in age were noted between the OM and VOC group. Temperature and CRP were significantly elevated in the OM group with no significant difference in WCC. Cultures were only positive in the chronic OM admissions. There were no cases of septic arthritis. No surgical intervention was required. CONCLUSION: In children with SCD presenting with persistent bone pain, fever, elevated CRP and WCC, OM should be suspected and prompt antibiotic treatment started. Our treatment pathway was successful avoiding OM in 98.6% and septic arthritis in 100%. Further research on novel biological markers distinguishing OM from VOC should be investigated. LEVEL OF EVIDENCE: III.

Intra-operative fluoroscopy time and radiation dose during suprapatellar tibial nailing versus infrapatellar tibial nailing.

BACKGROUND: Fractures of the tibial shaft are routinely managed with intramedullary nailing. An increasingly accepted technique is the suprapatellar extended leg method. The aim of this study was to investigate whether the suprapatellar tibial nailing technique offers shorter intraoperative fluoroscopy times and lower radiation doses when compared to the traditional infrapatellar technique. STUDY DESIGN AND METHODS: Data from 200 consecutive intramedullary tibial nailing operations in our level 1 Major Trauma Centre were retrospectively collected from a prospective database (January 2014-December 2017). Only acute diaphyseal nailing procedures were included. The operations were performed by seven senior trauma consultants experienced in both suprapatellar and infrapatellar tibial nailing. The operations were divided into two groups: infrapatellar and suprapatellar. Intraoperative radiation time and dose data were collected. RESULTS: A total of 90 cases were included and analysed. The majority of the patients were male (82%). 37 operations were infrapatellar and 53 were suprapatellar. Independent samples t-test revealed lower radiation time and dose for the suprapatellar group. The infrapatellar group had a mean radiation time of 129.7 ±â€¯56.6 s versus 94.4 ±â€¯47.9 s for the suprapatellar group. The infrapatellar group had a mean radiation dose (Dose Area Product) 53.6 ±â€¯34.2 cGY cm2 versus 38.2 ±â€¯26.7 cGY cm2 for the suprapatellar group. The difference in mean radiation time and mean radiation dose were both significant (p = 0.002 and p = 0.02 respectively). CONCLUSIONS: Suprapatellar tibial nailing is an increasingly accepted technique in the management of tibial fractures. It is shown here that amongst surgeons experienced in both suprapatellar and infrapatellar nailing techniques, the suprapatellar approach trends towards lower use of intra-operative fluoroscopy as measured by time and dose and thus potentially lower radiation exposure to the operating surgeon, assistants and patient.

Immediate weight bearing after plate fixation of fractures of the tibial plateau.

BACKGROUND: Proximal articular fractures of the tibia are commonly stabilised with internal fixation using plates and screws. There is a lack of evidence and conflicting guidelines as to the most suitable post-operative rehabilitation regime including weight bearing status. There are numerous physiological and socioeconomic benefits of early weight bearing after orthopaedic surgery, but concerns remain around loss of fracture reduction. Therefore, the aim of this study is to investigate whether the weight bearing status after tibial plateau plate fixation is associated with any loss of reduction or articular collapse. METHODS: We retrospectively analysed data from our prospectively collected major trauma centre database. All tibial plateau fractures that required open reduction and internal fixation with plate and screws were included. The immediate post-operative weight bearing status of these patients was recorded. Group I consisted of those patients that were either non-weight bearing or touch weight bearing for the first six post-operative weeks. Group II consisted of patients who were instructed to weight bear fully (as tolerated) immediately after the operation. Radiographs were taken on day one post-operation, at six weeks and at three months and analysed for fracture displacement and joint depression or loss of fixation. RESULTS: A total of 90 patients were included in the study. Group I (non-weight bearing or touch weight bearing) consisted of 60 patients (67%). Group II (full weight bearing as tolerated) consisted of 30 patients (33%). The follow up radiographs demonstrated no failure of fixation in either study group. One patient from the weight bearing group had >1 mm joint depression (4 mm) identified at the first follow up, which did not progress. CONCLUSIONS: This study shows immediate post-operative full weight bearing does not affect the fixation or cause articular collapse up to three months after surgery and thus we propose that patients should be allowed to weight bear immediately after surgical stabilisation of tibial plateau fractures. This will enable patients to benefit from the positive effects on fracture healing of early weight bearing post-surgery and avoid the complications of non-weight bearing without loss of fixation or articular collapse.

International Program to Monitor Cat Flea Populations for Susceptibility to Imidacloprid.

An international team of scientists and veterinarians was assembled in 1999 to develop a monitoring program to determine the susceptibility of cat fleas, Ctenocephalides felis felis (Bouché) (Siphonaptera: Pulicidae), to imidacloprid. Cat flea eggs were collected, shipped to laboratories, and tested for their susceptibility to imidacloprid. Over 3,000 C. felis populations were collected from 2002 to 2017 from 10 different countries. Of these, 66.3% were collected from cats and 33.7% from dogs. C. f. felis populations (n = 2,200) were bioassayed by exposing cat flea eggs and the emerging larvae to a Diagnostic Dose (DD) of 3 ppm imidacloprid in larval rearing medium. Flea eggs hatched and developed in the untreated controls in 1,837 of the isolates (83.5%) bioassayed. Flea isolates (n = 61) that had ≥5% survival at the DD of 3 ppm were retested with a second DD of 3 ppm. None of them had ≥5% survival to the second dose of 3 ppm. Of the 1,837 valid C. felis isolates tested, there has been no evidence of a decreased susceptibility to imidacloprid over the past 17 yr. The methods outlined in this article should provide an acceptable protocol for testing many of the new active ingredients that have been registered for cat flea control.

Radiotherapeutic implications of the updated ICRP thresholds for tissue reactions related to cataracts and circulatory diseases.

Radiation therapy of cancer patients involves a trade-off between a sufficient tumour dose for a high probability of local control and dose to organs at risk that is low enough to lead to a clinically acceptable probability of toxicity. The International Commission on Radiological Protection (ICRP) reviewed epidemiological evidence and provided updated estimates of 'practical' threshold doses for tissue injury, as defined at the level of 1% incidence, in ICRP Publication 118. Particular attention was paid to cataracts and circulatory diseases. ICRP recommended nominal absorbed dose threshold for these outcomes as low as 0.5 Gy. Threshold doses for tissue reactions can be reached in some patients during radiation therapy. Modern treatment planning systems do not account for such low doses accurately, and doses to therapy patients from associated imaging procedures are not generally accounted for. While local control is paramount, the observations of ICRP Publication 118 suggest that radiation therapy plans and processes should be examined with particular care. The research needs are discussed in this paper.

Helium in the eroding atmosphere of an exoplanet.

Helium is the second-most abundant element in the Universe after hydrogen and is one of the main constituents of gas-giant planets in our Solar System. Early theoretical models predicted helium to be among the most readily detectable species in the atmospheres of exoplanets, especially in extended and escaping atmospheres 1 . Searches for helium, however, have hitherto been unsuccessful 2 . Here we report observations of helium on an exoplanet, at a confidence level of 4.5 standard deviations. We measured the near-infrared transmission spectrum of the warm gas giant 3 WASP-107b and identified the narrow absorption feature of excited metastable helium at 10,833 angstroms. The amplitude of the feature, in transit depth, is 0.049 ± 0.011 per cent in a bandpass of 98 angstroms, which is more than five times greater than what could be caused by nominal stellar chromospheric activity. This large absorption signal suggests that WASP-107b has an extended atmosphere that is eroding at a total rate of 1010 to 3 × 1011 grams per second (0.1-4 per cent of its total mass per billion years), and may have a comet-like tail of gas shaped by radiation pressure.

Abrupt Climate Change in an Oscillating World.

The notion that small changes can have large consequences in the climate or ecosystems has become popular as the concept of tipping points. Typically, tipping points are thought to arise from a loss of stability of an equilibrium when external conditions are slowly varied. However, this appealingly simple view puts us on the wrong foot for understanding a range of abrupt transitions in the climate or ecosystems because complex environmental systems are never in equilibrium. In particular, they are forced by diurnal variations, the seasons, Milankovitch cycles and internal climate oscillations. Here we show how abrupt and sometimes even irreversible change may be evoked by even small shifts in the amplitude or time scale of such environmental oscillations. By using model simulations and reconciling evidence from previous studies we illustrate how these phenomena can be relevant for ecosystems and elements of the climate system including terrestrial ecosystems, Arctic sea ice and monsoons. Although the systems we address are very different and span a broad range of time scales, the phenomena can be understood in a common framework that can help clarify and unify the interpretation of abrupt shifts in the Earth system.