Abstract. Accurate assessment of anthropogenic carbon dioxide (CO2) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO2 emissions (EFOS) are based on energy statistics and cement production data, while emissions from land-use change (ELUC), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO2 concentration is measured directly, and its growth rate (GATM) is computed from the annual changes in concentration. The ocean CO2 sink (SOCEAN) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO2 sink (SLAND) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (BIM), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ. For the year 2021, EFOS increased by 5.1 % relative to 2020, with fossil emissions at 10.1 ± 0.5 GtC yr−1 (9.9 ± 0.5 GtC yr−1 when the cement carbonation sink is included), and ELUC was 1.1 ± 0.7 GtC yr−1, for a total anthropogenic CO2 emission (including the cement carbonation sink) of 10.9 ± 0.8 GtC yr−1 (40.0 ± 2.9 GtCO2). Also, for 2021, GATM was 5.2 ± 0.2 GtC yr−1 (2.5 ± 0.1 ppm yr−1), SOCEAN was 2.9 ± 0.4 GtC yr−1, and SLAND was 3.5 ± 0.9 GtC yr−1, with a BIM of −0.6 GtC yr−1 (i.e. the total estimated sources were too low or sinks were too high). The global atmospheric CO2 concentration averaged over 2021 reached 414.71 ± 0.1 ppm. Preliminary data for 2022 suggest an increase in EFOS relative to 2021 of +1.0 % (0.1 % to 1.9 %) globally and atmospheric CO2 concentration reaching 417.2 ppm, more than 50 % above pre-industrial levels (around 278 ppm). Overall, the mean and trend in the components of the global carbon budget are consistently estimated over the period 1959–2021, but discrepancies of up to 1 GtC yr−1 persist for the representation of annual to semi-decadal variability in CO2 fluxes. Comparison of estimates from multiple approaches and observations shows (1) a persistent large uncertainty in the estimate of land-use change emissions, (2) a low agreement between the different methods on the magnitude of the land CO2 flux in the northern extratropics, and (3) a discrepancy between the different methods on the strength of the ocean sink over the last decade. This living data update documents changes in the methods and data sets used in this new global carbon budget and the progress in understanding of the global carbon cycle compared with previous publications of this data set. The data presented in this work are available at https://doi.org/10.18160/GCP-2022 (Friedlingstein et al., 2022b).
Background:Pseudomeningocele is a known operative complication of Chiari decompression with significant morbidity.Methods:A retrospective analysis of 150 consecutive patients from November 1991 to June 2011 was conducted. Symptomatic pseudomeningocele was defined clinically; to meet definition it must have required operative intervention. Variables evaluated included sex, age, use of graft, and use of operative sealant. The Chi-square, Fisher test, and the two-sample t-test were used as appropriate to determine significance. Multiple logistic regression was used to determine independent risk factors for complication.Results:A total of 67.3% of patients were female, with average age being 39.7 years. A total of 67.3% of patients had a graft placed with the most common being fascia lata. Only nine patients (6%) presented with pseudomeningocele. Factors observed to be significantly associated with pseudomeningocele development were age and use of sealant. Age and sealant use were also independent risk factors for complication. Adjusted for the significant effect of age, odds for complication among patients with sealant usage were 6.67 times those for patients without sealant. Adjusted for the significance of sealant usage, there is a 6% increase in odds for complication for every year increase in patient's age.Conclusions:A statistically significant relationship exists between age and sealant use and the risk of developing a postoperative pseudomeningocele. Emphasis and attention must be placed on meticulous closure technique. This information can aide in preoperative planning and patient selection.
Background:There is scant literature evaluating the indications, techniques, and outcomes of minimally invasive spine (MIS) surgery undertaken for pediatric and adolescent spine pathology. Our study attempts to evaluate the safe and effective use of MIS techniques in pediatric and adolescent patients and to appreciate the technical nuances of MIS surgery for this age group.Methods:Consecutive pediatric and adolescent patients undergoing elective MIS lumbar procedures, from 2008 to 2016, were retrospectively analyzed from the practice of a single fellowship-trained academic spinal neurosurgeon. Information was retrieved regarding procedure and disease pathology. Descriptive data was obtained including age, sex, body mass index (BMI), insurance coverage, smoking status, and co-morbidities. Outcome measures were recorded including intraoperative complications, revision surgery, and return-to-function.Results:Sixteen patients underwent 17 surgeries. The median BMI was 29.2 (range, 20.8–41.5). Age ranged from 12 to 19 years. Nearly 20% of the patients in our series were smokers. Most patients underwent discectomy, with L5-S1 being the most common level. One patient underwent direct pars defect repair and another underwent recurrent discectomy. More than 90% of the patients were complication-free at follow-up period of 6 months. One patient had a recurrent disc herniation and another had a superficial wound infection. Overall, 82.4% patients enjoyed full return to sports such as weight lifting, gymnastics, and contact sports. One patient required pain management to help alleviate ongoing pain. Another patient required a course of outpatient rehabilitation to help with a “foot drop.”Conclusion:Our series illustrates the effective application of MIS techniques among carefully selected pediatric patients. Emphasis is on using a smaller (16 mm) tubular retractor and causing minimal disruption of paraspinal osseo-tendinous structures. MIS techniques can be successfully applied to the pediatric and adolescent age group.
Before the advent of endovascular coiling, patients with multiple intracranial aneurysms were treated with surgical clipping; however, with the advancements in endovascular technology, intracranial aneurysms can be treated with surgical clipping and/or endovascular coiling. We describe a case of subarachnoid hemorrhage in a patient with 7 intracranial aneurysms. A 45-year-old female developed a sudden headache and left sided hemiparesis. Initial workup showed a subarachnoid hemorrhage in the right Sylvian fissure. Further angiographic workup showed 7 intracranial aneurysms (left and right middle cerebral artery bifurcation, right middle cerebral artery, anterior communicating artery, left posterior communicating artery, right posterior inferior cerebellar artery, and left superior cerebellar artery). The patient underwent two craniotomies for surgical clipping of the anterior circulation aneurysms and endovascular stent-assisted coils for the posterior circulation aneurysms. The need for anti-platelet agents for endovascular treatment of the posterior circulation aneurysms and clinical presentation warranted surgical clipping of the anterior circulation aneurysms prior to endovascular therapy. We describe a case report and decision making for a patient with multiple intracranial aneurysms treated with surgical clipping and endovascular coiling.
HighlightsTo our knowledge, this is the first study to report resting state functional connectivity (FC) abnormalities associated with focal epilepsy caused by a single cerebral cavernous malformation (CCM).We show, by comparing to the data acquired from the age and gender matched control group, that this type of focal epilepsy is associated with the disruption of the normal regional and global FC. The disruption includes a decrease in the coactivation between the region surrounding the CCM lesion, i.e., the lesional region, and its homotopic counterpart, a reduction in FC between the lesional region and the rest of the brain, and decreased FC among the default mode network (DMN).These changes may be alleviated or reversed after the surgical resection of the CCM and the epileptogenic zone has successfully stopped recurrent seizures.Finally, the severity of the FC disruption in the brain tissue adjacent to the CCM may be used to delineate the epileptogenic zone and to aid the surgical resection.
Accurate assessment of anthropogenic carbon dioxide (CO 2 ) emissions and their redistribution among the atmosphere, ocean, and terrestrial biosphere in a changing climate is critical to better understand the global carbon cycle, support the development of climate policies, and project future climate change. Here we describe and synthesize data sets and methodologies to quantify the five major components of the global carbon budget and their uncertainties. Fossil CO 2 emissions (E FOS ) are based on energy statistics and cement production data, while emissions from land-use change (E LUC ), mainly deforestation, are based on land use and land-use change data and bookkeeping models. Atmospheric CO 2 concentration is measured directly, and its growth rate (G ATM ) is computed from the annual changes in concentration. The ocean CO 2 sink (S OCEAN ) is estimated with global ocean biogeochemistry models and observation-based data products. The terrestrial CO 2 sink (S LAND ) is estimated with dynamic global vegetation models. The resulting carbon budget imbalance (B IM ), the difference between the estimated total emissions and the estimated changes in the atmosphere, ocean, and terrestrial biosphere, is a measure of imperfect data and understanding of the contemporary carbon cycle. All uncertainties are reported as ±1σ .For the year 2021, E FOS increased by 5.1 % relative to 2020, with fossil emissions at 10.1 ± 0.5 GtC yr −1 (9.9 ± 0.5 GtC yr −1 when the cement carbonation sink is included), and E LUC was 1.1 ± 0.7 GtC yr −1 , direct atmospheric CO 2 measurements from the Mauna Loa and South Pole stations (Keeling et al., 1976). To account for the difference in mean CO 2 and seasonality between the NOAA/GML and the Scripps station networks used here, the Scripps surface average (from two stations) was de-seasonalized and adjusted to match the NOAA/GML surface average (from multiple stations) by adding the mean difference of 0.667 ppm, calculated here from overlapping data during 1980-2012. crease in 2020) are hard to detect in the atmospheric CO 2 observations.
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