107 research outputs found
Combined pesticide exposure severely affects individual- and colony-level traits in bees
Reported widespread declines of wild and managed insect pollinators have serious consequences for global ecosystem services and agricultural production [1–3]. Bees contribute approximately 80% of insect pollination, so it is important to understand and mitigate the causes of current declines in bee populations [4–6]. Recent studies have implicated the role of pesticides in these declines, as exposure to these chemicals has been associated with changes in bee behaviour [7–11] and reductions in colony queen production [12]. However, the key link between changes in individual behaviour and the consequent impact at the colony level has not been shown. Social bee colonies depend on the collective performance of many individual workers. Thus, although field-level pesticide concentrations can have subtle or sublethal effects at the individual level [8], it is not known whether bee societies can buffer such effects or whether it results in a severe cumulative effect at the colony level. Furthermore, widespread agricultural intensification means that bees are exposed to numerous pesticides when foraging [13–15], yet the possible combinatorial effects of pesticide exposure have rarely been investigated [16,17]. Here we show that chronic exposure of bumblebees to two pesticides (neonicotinoid and pyrethroid) at concentrations that could approximate field-level exposure impairs natural foraging behaviour and increases worker mortality leading to significant reductions in brood development and colony success. We found that worker foraging performance, particularly pollen collecting efficiency, was significantly reduced with observed knock-on effects for forager recruitment, worker losses and overall worker productivity. Moreover, we provide evidence that combinatorial exposure to pesticides increases the propensity of colonies to fail
Neonicotinoid Insecticides and Their Impacts on Bees: A Systematic Review of Research Approaches and Identification of Knowledge Gaps
It has been suggested that the widespread use of neonicotinoid insecticides threatens bees, but research on this topic has been surrounded by controversy. In order to synthesize which research approaches have been used to examine the effect of neonicotinoids on bees and to identify knowledge gaps, we systematically reviewed research on this subject that was available on the Web of Science and PubMed in June 2015. Most of the 216 primary research studies were conducted in Europe or North America (82%), involved the neonicotinoid imidacloprid (78%), and concerned the western honey bee Apis mellifera (75%). Thus, little seems to be known about neonicotinoids and bees in areas outside Europe and North America. Furthermore, because there is considerable variation in ecological traits among bee taxa, studies on honey bees are not likely to fully predict impacts of neonicotinoids on other species. Studies on crops were dominated by seed-treated maize, oilseed rape (canola) and sunflower, whereas less is known about potential side effects on bees from the use of other application methods on insect pollinated fruit and vegetable crops, or on lawns and ornamental plants. Laboratory approaches were most common, and we suggest that their capability to infer real-world consequences are improved when combined with information from field studies about realistic exposures to neonicotinoids. Studies using field approaches often examined only bee exposure to neonicotinoids and more field studies are needed that measure impacts of exposure. Most studies measured effects on individual bees. We suggest that effects on the individual bee should be linked to both mechanisms at the sub-individual level and also to the consequences for the colony and wider bee populations. As bees are increasingly facing multiple interacting pressures future research needs to clarify the role of neonicotinoids in relative to other drivers of bee declines
Treatment of Tumors of the Spine
Thirty-one patients with spinal tumors underwent reconstructive surgery with our spinal instrumentation system (MPDS and MADS), with or without our new vertebral tumor prosthesis. The characteristics of the spinal tumors were analysed statistically and the treatment outcome was evaluated. There were 4 benign tumors, 6 malignant tumors, and 21 metastatic tumors. The malignant tumors involved the sacrum more frequently than the benign tumors (p=0.0098). Metastatic tumors involved the thoracic spine more frequently than benign or malignant tumors (p=0.0161). The average number of affected vertebrae was 1.2 in the benign tumors, 1.8 in the malignant tumors, and 2.4 in the metastatic tumors. The metastatic tumors had a tendency to involve the anterior or middle part of the spine more frequently than the benign or malignant tumors (statistically not significant). After surgery, neurological improvement was noted in 8 patients, nochange in 19 patients, and impairment due to resection of the nerve roots in sacral tumors in 4 patients
Perioperative complications after surgical treatment in degenerative adult de novo scoliosis
Abstract Background Degenerative adult de novo (DAD) scoliosis appears characteristically in the sixth or seventh decade with symptoms of severe back pain and radiculopathy or spinal claudication. The aim of this study was to enhance the knowledge of perioperative complications and detect possible risk factors in this selective DAD scoliosis surgery. Methods This retrospective study included only patients with DAD scoliosis undergone correction spondylodesis with previous failure of conservative treatment. Excluded were patients with other types of scoliosis and previous fusion surgeries. Patient epidemiological data, medical comorbidities and treatments were included. Intraoperative data and perioperative complications were documented. Analyses regarding early, late and no complications were undertaken. Results A total of 92 patients with a mean age of 67.29 ± 7.93 years and clinical follow-up visits of minimum 12 months were included. On average, 5.26 ± 2.24 segments were fused. Early complications (e.g. wound healing defects, paresis, screw loosing) occurred in 23 patients and often required a re-operation. Cardiac arrhythmias, pacemaker and coumarin derivative therapies were associated with increased perioperative complications. The transforaminal lumbar interbody fusion technique was associated with early complications. Adjacent segment failure occurred in 36% and was the major late complication. Twenty patients did not have any complications in the minimum follow-up. Conclusions This study analysed a selective DAD scoliosis collective and its’ surgical treatment outcomes. It identified numerous perioperative complications (adjacent segment failure, postoperative paresis and epidural hematoma) and multiple possible predisposing risk factors (e.g. operative techniques and anti-coagulation therapies). This here gained information raises awareness in preoperative patient selection and preparation. Further studies in DAD scoliosis and a risk-adjusted patient selection/preparation are needed to improve treatment quality and outcomes
Magneto-Optics of Excited States of the Donor–Exciton Complex in CdS A Proof for the Excited-Hole-States Model
Novel AI-Based Algorithm for the Automated Computation of Coronal Parameters in Adolescent Idiopathic Scoliosis Patients
Study design:
Retrospective, mono-centric cohort research study.
Objectives:
The purpose of this study is to validate a novel artificial intelligence (AI)-based algorithm against human-generated ground truth for radiographic parameters of adolescent idiopathic scoliosis (AIS).
Methods:
An AI-algorithm was developed that is capable of detecting anatomical structures of interest (clavicles, cervical, thoracic, lumbar spine and sacrum) and calculate essential radiographic parameters in AP spine X-rays fully automatically. The evaluated parameters included T1-tilt, clavicle angle (CA), coronal balance (CB), lumbar modifier, and Cobb angles in the proximal thoracic (C-PT), thoracic, and thoracolumbar regions. Measurements from 2 experienced physicians on 100 preoperative AP full spine X-rays of AIS patients were used as ground truth and to evaluate inter-rater and intra-rater reliability. The agreement between human raters and AI was compared by means of single measure Intra-class Correlation Coefficients (ICC; absolute agreement; .75 rated as excellent), mean error and additional statistical metrics.
Results:
The comparison between human raters resulted in excellent ICC values for intra- (range: .97-1) and inter-rater (.85-.99) reliability. The algorithm was able to determine all parameters in 100% of images with excellent ICC values (.78-.98). Consistently with the human raters, ICC values were typically smallest for C-PT (eg, rater 1A vs AI: .78, mean error: 4.7°) and largest for CB (.96, -.5 mm) as well as CA (.98, .2°).
Conclusions:
The AI-algorithm shows excellent reliability and agreement with human raters for coronal parameters in preoperative full spine images. The reliability and speed offered by the AI-algorithm could contribute to the efficient analysis of large datasets (eg, registry studies) and measurements in clinical practice
Superficial fibular nerve variations of fascial piercing: A meta-analysis and clinical consideration
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Association of Scheduled vs Emergency-Only Dialysis With Health Outcomes and Costs in Undocumented Immigrants With End-stage Renal Disease.
Importance:In 40 of 50 US states, scheduled dialysis is withheld from undocumented immigrants with end-stage renal disease (ESRD); instead, they receive intermittent emergency-only dialysis to treat life-threatening manifestations of ESRD. However, the comparative effectiveness of scheduled dialysis vs emergency-only dialysis and the influence of treatment on health outcomes, utilization, and costs is uncertain. Objective:To compare the effectiveness of scheduled vs emergency-only dialysis with regard to health outcomes, utilization, and costs in undocumented immigrants with ESRD. Design, Setting, and Participants:Observational cohort study of 181 eligible adults with ESRD receiving emergency-only dialysis in Dallas, Texas, who became newly eligible and applied for private commercial health insurance in February 2015; 105 received coverage and were enrolled in scheduled dialysis; 76 were not enrolled in insurance for nonclinical reasons (eg, lack of capacity at a participating outpatient dialysis center) and remained uninsured, receiving emergency-only dialysis. We examined data on eligible persons during a 6-month period prior to enrollment (baseline period, August 1, 2014-January 31, 2015) until 12 months after enrollment (follow-up period, March 1, 2015-February 29, 2016), with an intervening 1-month washout period (February 2015). All participants were undocumented immigrants; self-reported data on immigration status was collected from Parkland Hospital electronic health records. Exposures:Enrollment in private health insurance coverage and scheduled dialysis. Main Outcomes and Measures:We used enrollment in health insurance and scheduled dialysis to estimate the influence of scheduled dialysis on 1-year mortality, utilization, and health care costs, using a propensity score-adjusted, intention-to-treat approach, including time-to-event analyses for mortality, difference-in-differences (DiD) negative binomial regression analyses for utilization, and DiD gamma generalized linear regression for health care costs. Results:Of 181 eligible adults with ESRD, 105 (65 men, 40 women; mean age, 45 years) received scheduled dialysis and 76 (38 men, 38 women; mean age, 52 years) received emergency-only dialysis. Compared with emergency-only dialysis, scheduled dialysis was significantly associated with reduced mortality (3% vs 17%, P = .001; absolute risk reduction, 14%; number needed to treat, 7; adjusted hazard ratio, 4.6; 95% CI, 1.2-18.2; P = .03), adjusted emergency department visits (-5.2 vs +1.1 visits/mo; DiD, -6.2; P < .001), adjusted hospitalizations (-2.1 vs -0.5 hospitalizations/6 months; DiD, -1.6; P < .001), adjusted hospital days (-9.2 vs +0.8 days/6 months; DiD, -9.9; P = .007), and adjusted costs (-1452 per person per month; DiD, -$5768; P < .001). Conclusions and Relevance:In this study, scheduled dialysis was significantly associated with reduced 1-year mortality, health care utilization, and costs compared with emergency-only dialysis. Scheduled dialysis should be the universal standard of care for all individuals with ESRD in the United States
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