Floristic evidence for alternative biome states in tropical Africa.

The idea that tropical forest and savanna are alternative states is crucial to how we manage these biomes and predict their future under global change. Large-scale empirical evidence for alternative stable states is limited, however, and comes mostly from the multimodal distribution of structural aspects of vegetation. These approaches have been criticized, as structure alone cannot separate out wetter savannas from drier forests for example, and there are also technical challenges to mapping vegetation structure in unbiased ways. Here, we develop an alternative approach to delimit the climatic envelope of the two biomes in Africa using tree species lists gathered for a large number of forest and savanna sites distributed across the continent. Our analyses confirm extensive climatic overlap of forest and savanna, supporting the alternative stable states hypothesis for Africa, and this result is corroborated by paleoecological evidence. Further, we find the two biomes to have highly divergent tree species compositions and to represent alternative compositional states. This allowed us to classify tree species as forest vs. savanna specialists, with some generalist species that span both biomes. In conjunction with georeferenced herbarium records, we mapped the forest and savanna distributions across Africa and quantified their environmental limits, which are primarily related to precipitation and seasonality, with a secondary contribution of fire. These results are important for the ongoing efforts to restore African ecosystems, which depend on accurate biome maps to set appropriate targets for the restored states but also provide empirical evidence for broad-scale bistability.

Phylogenomics resolves major relationships and reveals significant diversification rate shifts in the evolution of silk moths and relatives.

BACKGROUND: Silkmoths and their relatives constitute the ecologically and taxonomically diverse superfamily Bombycoidea, which includes some of the most charismatic species of Lepidoptera. Despite displaying spectacular forms and diverse ecological traits, relatively little attention has been given to understanding their evolution and drivers of their diversity. To begin to address this problem, we created a new Bombycoidea-specific Anchored Hybrid Enrichment (AHE) probe set and sampled up to 571 loci for 117 taxa across all major lineages of the Bombycoidea, with a newly developed DNA extraction protocol that allows Lepidoptera specimens to be readily sequenced from pinned natural history collections. RESULTS: The well-supported tree was overall consistent with prior morphological and molecular studies, although some taxa were misplaced. The bombycid Arotros Schaus was formally transferred to Apatelodidae. We identified important evolutionary patterns (e.g., morphology, biogeography, and differences in speciation and extinction), and our analysis of diversification rates highlights the stark increases that exist within the Sphingidae (hawkmoths) and Saturniidae (wild silkmoths). CONCLUSIONS: Our study establishes a backbone for future evolutionary, comparative, and taxonomic studies of Bombycoidea. We postulate that the rate shifts identified are due to the well-documented bat-moth "arms race". Our research highlights the flexibility of AHE to generate genomic data from a wide range of museum specimens, both age and preservation method, and will allow researchers to tap into the wealth of biological data residing in natural history collections around the globe.

Correlation of the Caprini Score and Venous Thromboembolism Incidence Following Primary Total Joint Arthroplasty-Results of a Single-Institution Protocol.

BACKGROUND: Venous thromboembolism (VTE), including pulmonary embolism (PE) and deep vein thrombosis, is a serious complication after total joint arthroplasty (TJA). Risk assessment models are increasingly used to provide patient-specific risk stratification. A recently implemented protocol mandates calculation of a Caprini Score for all surgical patients at our institution. We investigated the accuracy of the Caprini Score in predicting VTE events following TJA. METHODS: A retrospective review of patients undergoing primary total hip (THA) and total knee arthroplasty (TKA) over a 1-year time period was performed. The 90-day postoperative incidence of emergency department evaluations, hospital readmissions, medical complications, need for revision surgery, and symptomatic VTE was recorded. "Preoperative" Caprini Scores routinely recorded per protocol and calculated during review ("Calculated") were compared and assessed for relationship with VTE events. A "VTEstimator" Score was calculated for each patient. RESULTS: Three hundred seventy-six arthroplasties (151 TKA and 225 THA) meeting inclusion criteria were identified. Ten patients (2.5%) had symptomatic VTE postoperatively, with 3 pulmonary embolism (0.8%) and 7 deep vein thrombosis (1.8%). Eight VTE (5.3%) occurred following TKA and 2 (0.9%) occurred following THA. For each surgical characteristic evaluated, no significant difference was observed between mean Preoperative or Calculated Caprini Scores for patients with and without VTE (P > .05). Additionally, the distribution of VTEstimator Scores for patients with and without VTE was not significantly different (P = .93). CONCLUSION: The Caprini risk assessment model does not appear to provide clinically useful risk stratification for TJA patients. Alternative risk stratification protocols may provide assistance in balancing safety and efficacy of thromboprophylaxis.

Suture anchor fixation of displaced olecranon fractures in the elderly: a case series and surgical technique.

BACKGROUND: Olecranon fractures are common in elderly patients, causing significant morbidity and functional impairment. Traditional surgical treatments are often complicated by hardware failure and prominence, frequently requiring reoperation. To address these concerns, a suture anchor fixation technique was developed and clinically evaluated. METHODS: A consecutive series of elderly patients treated with this technique from 2006 to 2013 at a single institution were studied. All cases were surgically repaired with nonmetallic fully threaded suture anchors in a double-row fashion. Clinical outcome measures including the shortened Disabilities of the Arm, Shoulder, and Hand score, the Oxford Elbow Score, and the 12-Item Short Form Health Survey score were obtained. RESULTS: Eight female patients with Mayo IIA or IIB fractures were identified. The mean age of the patients at time of operation was 73.5 ± 10.7 years (range, 59.3-88.8 years). The average time from injury to operation was 5.7 ± 3.7 days. The average follow-up was 5.1 ± 2.5 years (range, 0.8-7.4 years). Six patients were available for long-term follow-up; 1 patient had died, and 1 patient was unable to be contacted despite multiple attempts. There were no intraoperative complications or reoperations. All 8 patients healed uneventfully in an acceptable position without displacement. Postoperatively, the average Oxford Elbow Score was 47.17 ± 2.04; the average shortened Disabilities of the Arm, Shoulder, and Hand score was 6.43 ± 9.47; and the average 12-Item Short Form Health Survey scores were 49.02 ± 16.59 and 55.38 ± 4.05 for the physical and mental component scales, respectively. CONCLUSION: Suture anchor fixation of olecranon fractures in the elderly population provides excellent long-term radiographic and clinical outcomes without hardware complications associated with traditional fixation methods.

Bicruciate Retaining Total Knee Arthroplasty: Short-Term Clinical Outcomes Using a Novel Prosthesis.

There is renewed interest in bicruciate retaining (BCR) total knee arthroplasty (TKA), which preserves anatomy and more closely replicates native kinematics, theoretically allowing for improved functional results when compared to posterior stabilized (PS) TKA or cruciate retaining (CR) TKA. The purpose of this study is to report early clinical and radiographic results for a novel BCR TKA design.

Comparison Between the Attune and PFC Sigma in Total Knee Arthroplasty: No Difference in Patellar Clunk and Crepitus or Anterior Knee Pain.

Patellar crepitus and clunk (PCC) is a known complication in total knee arthroplasty (TKA) and the cause of dissatisfaction. Patellofemoral articulations have reportedly been optimized in newer TKAs. This study compared the incidence of PCC between a historical and modern TKA design. A single-surgeon retrospective review of primary PFC Sigma (DePuy Synthes, Warsaw, Indiana) or Attune TKA (DePuy Synthes) was performed. A total of 114 PFC Sigma and 103 Attune implants were analyzed at a mean 3.2 years follow-up for overall PCC, painful PCC, anterior knee pain (regardless of crepitus), and PCC necessitating revision. Similar rates of overall PCC (14.6% vs 20.2%, P=.803), painful PCC (8.7% vs 6.1%, P=.605), and anterior knee pain (15.5% vs 9.7%, P=.219) were observed in the Attune and PFC Sigma groups, respectively. No clinically significant differences in range of motion, pain, or Knee Society Scores were found between groups. Subgroup analyses of mobile vs fixed bearing PFC Sigma implants demonstrated higher rates of overall PCC (32.4% vs 15.0%, P=.043), painful PCC (20.6% vs 5.0%, P=.016), anterior knee pain (17.6% vs 1.3%, P=.003), and crepitus requiring revision surgery (17.6% vs 1.3%, P=.003) for mobile bearing PFC Sigma implants. No difference was found in the rates of anterior knee pain or PCC between the PFC Sigma and Attune implants. Subgroup analysis suggests that a mobile bearing PFC Sigma implant results in higher PCC. The authors believe the true incidence of anterior knee pain and PCC is underreported in the literature because many outcome measures do not capture these complications. [Orthopedics. 2020;43(6):e508-e514.].

Marine heatwaves and the collapse of marginal North Atlantic kelp forests.

Extreme climatic events including marine heatwaves (MHWs) are becoming more frequent and severe in the Anthropocene. However, our understanding of how these events affect population dynamics of ecologically important species is limited, in part because extreme events are rare and difficult to predict. Here, we quantified the occurrence and severity of MHWs over 60 years in warm range edge kelp forests on both sides of the North Atlantic. The cumulative annual intensity of MHWs increased two- to four-fold during this period, coinciding with the disappearance of kelps. We experimentally demonstrated a relationship between strong and severe 2018 heatwaves and high kelp mortality in both regions. Patterns of kelp mortality were strongly linked to maximum temperature anomalies, which crossed lethal thresholds in both regions. Translocation and tagging experiments revealed similar kelp mortality rates on reefs dominated by healthy kelp forests and degraded sediment-laden algal 'turfs', indicating equal vulnerability to extreme events. These results suggest a mechanistic link between MHWs and broad-scale kelp loss, and highlight how warming can make ecosystem boundaries unstable, forcing shifts to undesirable ecosystem states under episodically extreme climatic conditions.

Synthetic Mesh Allograft Reconstruction for Extensor Mechanism Insufficiency After Knee Arthroplasty.

Extensor mechanism (EM) insufficiency after knee arthroplasty is a rare but devastating complication resulting in severe disability. To date, primary repair and allograft reconstructive options have produced suboptimal results. A synthetic mesh allograft reconstruction technique has recently been introduced with promising outcomes. A retrospective chart review was performed to identify all patients who experienced EM failure after total or unicompartmental knee arthroplasty and subsequently underwent synthetic mesh EM reconstruction using a previously described technique. Patient demographics, pre- and postoperative knee range of motion and residual extensor lag, pre- and postoperative pain and functional outcome scores, and complications were extracted during the chart review. Twelve patients met inclusion criteria: 3 with patellar tendon and 9 with quadriceps tendon defects. At mean follow-up of 27.0 months, all patients were ambulatory, with a mean residual extensor lag of 12.9° (range, 0°-30°). Mean visual analog scale pain score decreased significantly after EM reconstruction: 4.6±2.3 (range, 1-8) preoperatively vs 1.8±2.4 (range, 0-7) postoperatively (P=.01). The mean Knee Society knee score improved from 41.5±11.1 (range, 21-57) preoperatively to 79.5±13.8 (range, 54-90) postoperatively (P<.0001). The mean Knee Society function score improved from 14.6±12.3 (range, 0-40) preoperatively to 64.2±27.1 (range, 5-95) postoperatively (P<.0001). One clinical failure occurred as a result of prosthetic joint infection. Synthetic mesh EM reconstruction effectively restores knee function for a variety of EM deficiencies following knee arthroplasty. [Orthopedics. 2019; 42(4):e385-e390.].

Outcomes Following Arthroscopic Repair of Posterior Labral Tears in Patients Older Than 35 Years.

Although the results of arthroscopic management of posterior labral pathology in young athletes have been reported extensively in the literature, the clinical outcomes in older patients are unknown. This retrospective review included patients older than 35 years who underwent arthroscopic posterior labral repair. Functional outcome scores were collected, and subgroup analyses were performed to evaluate the impact of patient-specific factors. Forty-three patients met the inclusion criteria; average follow-up was 36.9 months (range, 24-54 months). Mean patient age at the time of surgery was 40.9 years (range, 35-57 years). Average outcome scores at final follow-up were Quick Disabilities of the Arm, Shoulder and Hand Scale (QuickDASH), 19±22; Simple Shoulder Test (SST), 9.9±3; Western Ontario Shoulder Instability Index (WOSI), 601±546; and Single Assessment Numeric Evaluation (SANE), 79.6%±23.4%. No significant differences in outcomes were observed in patients with preoperative symptomatic instability, active workers' compensation claims, or traumatic injury (P>.05). The presence of intraoperatively definable chondral damage (Outerbridge grade III or higher) was associated with significantly worse final functional outcomes (QuickDASH: 29 vs 11.9, P=.03; SST: 8.5 vs 10.9, P=.02; WOSI: 875 vs 407, P=.01; and SANE: 70.6% vs 86%, P=.05). One patient (2%) experienced a minor postoperative complication, and 3 patients (7%) required subsequent procedures: 2 total shoulder arthroplasties and 1 revision labral repair. The results of arthroscopic posterior labral repair in patients older than 35 years were variable and worse than those previously reported in younger patients. The presence of chondral damage at the time of the index procedure was a negative predictive factor. [Orthopedics. 2017; 40(2):e305-e311.].

Metastatic lesion of the anterior mandible with an occult primary: a case report.

Metastatic tumors to the oral cavity are relatively uncommon and account for about 1% of all oral cancers. Distant metastases to the jawbone are associated with a poor prognosis and a survival rate that is usually less than one year. The leading common primary sites for these lesions are the breast in females and the lung in males followed by the adrenals, kidneys, prostate, thyroid and colon. In 30% of all cancers, a metastatic lesion could be the first sign of a primary tumor elsewhere in the body. Metastatic lesions to the jaws are known to simulate periodontal and pulpal disease and other radiolucent lesions that can occur in the jaws. Microscopic evaluation with concurrent radiographic skeletal survey is warranted in patients where a metastatic lesion is suspected.

Glenoid Dysplasia.

Glenoid dysplasia is a developmental anomaly of the scapula that is characterized by a bony deficiency of the posteroinferior glenoid and the adjacent scapular neck. Glenoid dysplasia may occur as a primary isolated condition or in association with various syndromes. It is thought to be related to defective ossification of the inferior glenoid precartilage. Radiographs typically demonstrate bilateral, symmetric dysplasia of the scapular neck with a range of associated bony changes. Glenoid dysplasia has been associated with instability and premature glenohumeral arthritis, although the clinical presentation is highly variable. Symptoms are delayed or mitigated as a result of compensatory glenoid labral hyperplasia. The treatment of glenoid dysplasia remains challenging. Nonsurgical treatment is reasonably successful in younger patients, but premature degenerative changes frequently occur. Although favorable results can be obtained with the use of anatomic arthroplasty, continued subluxation and glenoid component failure can lead to unacceptable outcomes.

L5/S1 Fusion Rates in Degenerative Spine Surgery: A Systematic Review Comparing ALIF, TLIF, and Axial Interbody Arthrodesis.

STUDY DESIGN: Systematic review. OBJECTIVE: To determine the fusion rate of an anterior lumbar interbody fusion (ALIF), transforaminal lumbar interbody fusion (TLIF), and axial arthrodesis at the lumbosacral junction in adult patients undergoing surgery for 1- and 2-level degenerative spine conditions. SUMMARY OF BACKGROUND DATA: An L5/S1 interbody fusion is a commonly performed procedure for pathology such as spondylolisthesis with stenosis; however, it is unclear if 1 technique leads to superior fusion rates. MATERIALS AND METHODS: A systematic search of MEDLINE was conducted for literature published between January 1, 1992 and August 17, 2014. All peer-reviewed articles related to the fusion rate of L5/S1 for an ALIF, TLIF, or axial interbody fusion were included. RESULTS: In total, 42 articles and 1507 patients were included in this systematic review. A difference in overall fusion rates was identified, with a rate of 99.2% (range, 96.4%-99.8%) for a TLIF, 97.2% (range, 91.0%-99.2%) for an ALIF, and 90.5% (range, 79.0%-97.0%) for an axial interbody fusion (P=0.005). In a paired analysis directly comparing fusion techniques, only the difference between a TLIF and an axial interbody fusion was significant. However, when only cases in which bilateral pedicle screws supported the interbody fusion, no statistical difference (P>0.05) between the 3 techniques was identified. CONCLUSIONS: The current literature available to guide the treatment of L5/S1 pathology is poor, but the available data suggest that a high fusion rate can be expected with the use of an ALIF, TLIF, or axial interbody fusion. Any technique-dependent benefit in fusion rate can be eliminated with common surgical modifications such as the use of bilateral pedicle screws.

Anterior lumbar spine surgery: a systematic review and meta-analysis of associated complications.

BACKGROUND CONTEXT: The anterior approach to the lumbar spine is increasingly used to accomplish various surgical procedures. However, the incidence and risk factors for complications associated with anterior lumbar spine surgery (ALS) have not been fully elucidated. PURPOSE: To identify and document types of complications and complication rates associated with ALS, determine risk factors for these events, and evaluate the effect of measures used to decrease complication rates. STUDY DESIGN: Systematic review and meta-analysis. METHODS: A systematic review of the English-language literature was conducted for articles published between January 1992 and December 2013. A MEDLINE search was conducted to identify articles reporting complications associated with ALS. For each complication, the data were combined using a generalized linear mixed model with a binomial probability distribution and a random effect based on the study. Predictors used were the type of procedure (open, minimally invasive, or laparoscopic), the approach used (transperitoneal vs. retroperitoneal), use of recombinant bone morphogenetic protein-2, use of preoperative computed tomography angiography (CTA), and the utilization of an access surgeon. Open surgery was used as a reference category. RESULTS: Seventy-six articles met final inclusion criteria and reported complication rates in 11,410 patients who underwent arthrodesis and/or arthroplasty via laparoscopic, mini-open, and open techniques. The overall complication rate was 14.1%, with intraoperative and postoperative complication rates of 9.1% and 5.2%, respectively. Only 3% of patients required reoperation or revision procedures. The most common complications reported were venous injury (3.2%), retrograde ejaculation (2.7%), neurologic injury (2%), prosthesis related (2%), postoperative ileus (1.4%), superficial infection (1%), and others (1.3%). Laparoscopic and transperitoneal procedures were associated with higher complication rates, whereas lower complication rates were observed in patients receiving mini-open techniques. Our analysis indicated that the use of recombinant bone morphogenetic protein-2 was associated with increased rates of retrograde ejaculation; however, there may be limitations in interpreting these data. Data regarding the use of preoperative CTA and an access surgeon were limited and demonstrated mixed benefit. CONCLUSIONS: Overall complication rates with ALS are relatively low, with the most common complications occurring at a rate of 1% to 3%. Complication rates are related to surgical technique, approach, and implant characteristics. Further randomized controlled trials are needed to validate the use of preventative measures including CTA and the use of an access surgeon.

Promoting AIDS risk reduction via behavioral training.

The present study employed behavioral techniques to teach assertive strategies designed to reduce the risk of contracting AIDS and to promote "safer-sex" behaviors. A total of 79 university students (38 male and 41 female) were included in the final data analysis. Subjects participated in three one-hour training sessions which included live modeling of assertive interactions, role-playing, behavior shaping, corrective feedback, verbal reinforcement, assertiveness training, and an AIDS educational lecture. Dependent measures included ratings of the key components of assertive behavior from videotaped role-plays at pre- and posttests. Behavioral training had a positive effect on participants' assertive behavior. On the role-play ratings, experimental subjects were rated higher on overall assertiveness than the controls. Even brief behaviorally based educational interventions can produce increases in assertive behaviors known to be related to AIDS prevention, for example, insisting on condom use and requesting information about a prospective partner's sexual and drug use histories. Behavior changes extended to in vivo situations, of course, remain less assured.

Mobility of heavy metals within freshwater sediments affected by motorway stormwater.

The assessment of the mobility and bioavailability of heavy metals in sediment samples requires the use of sequential extraction procedures. Results for sediments taken from an unmanaged motorway detention pond showed heavy metals to be associated with the carbonate and residual fractions. In particular, nickel and cadmium showed a high percentage association, compared with other geochemical fractions, such as carbonates and residual fractions. Copper and zinc were shown to be associated with carbonates and iron-manganese oxides, whereas lead showed the strongest association (72%) with the Fe-Mn oxides. When compared to a groundwater-fed lake on the same site, all heavy metals contained within this sediment were found to be at much lower concentrations and strongly associated with the residual fraction (>50%) and are therefore strongly bound within the sediment. Following discharge via a wet detention pond, stormwater then flows through a series of interconnecting lake systems. Heavy metal fractionation of these interconnecting lakes is discussed and shows changes in fractionation through the lake system for copper, nickel, lead and zinc. The main concern in these lakes is the continued use of calcium carbonate to maintain freshwater pH for coarse fishing. This practice, used until 1999, may present an enhanced risk to the freshwater environment, causing greater mobility of these metals.

Variable optical attenuator for use in the visible spectrum.

A method for attenuating a laser beam based on the excitation of a surface plasmon is described. This attenuator is continuously variable, has a dynamic range of 10(2), has a spectral range covering the visible, does not steer the beam or distort its profile, and can handle powers of at least 1-W cw. Some preliminary results obtained on a crude prototype are presented; final device design and predicted performance are discussed.