The mobilization and transport of newly fixed carbon are driven by plant water use in an experimental rainforest under drought

Non-structural carbohydrates (NSCs) are building blocks for biomass and fuel metabolic processes. However, it remains unclear how tropical forests mobilize, export, and transport NSCs to cope with extreme droughts. We combined drought manipulation and ecosystem 13CO2 pulse-labeling in an enclosed rainforest at Biosphere 2, assessed changes in NSCs, and traced newly assimilated carbohydrates in plant species with diverse hydraulic traits and canopy positions. We show that drought caused a depletion of leaf starch reserves and slowed export and transport of newly assimilated carbohydrates below ground. Drought effects were more pronounced in conservative canopy trees with limited supply of new photosynthates and relatively constant water status than in those with continual photosynthetic supply and deteriorated water status. We provide experimental evidence that local utilization, export, and transport of newly assimilated carbon are closely coupled with plant water use in canopy trees. We highlight that these processes are critical for understanding and predicting tree resistance and ecosystem fluxes in tropical forest under drought.

Medial Ulnar Collateral Ligament Reconstruction with Allograft Provides Excellent Clinical Outcomes, High Rates of Return to Play, and a Low Incidence of Postoperative Complications: A Systematic Review

PURPOSE

To perform a systematic review evaluating clinical outcomes in patients undergoing medial ulnar collateral ligament reconstruction (MUCLR) with soft tissue allograft.

METHODS

A systematic review of the literature was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. The primary outcomes evaluated were patient-reported outcome scores, return to play (RTP) rates, incidence of postoperative complications, and rates of graft rupture or mechanical failure.

RESULTS

The literature search identified 395 articles and five studies met final inclusion criteria following full-text review. A total of 274 patients were analyzed in the included studies and follow up ranged from 3.0 to 7.6 years. Two studies (n patients = 141) reported outcomes exclusively of MUCLR with allograft, while three studies (n patients = 133) reported outcomes in patients undergoing MUCLR with either allograft or autograft. Allograft sources included gracilis, semitendinosus, plantaris, peroneus longus, and palmaris longus. Level of patient athletic competition ranged from recreational athletes to the professional level, however, non-athletes in the setting of trauma were also included. The RTP rate following MUCLR with soft tissue allograft was 95.3%, and 89.3% of patients returned to a similar or higher level of play postoperatively. The Timmerman-Andrews score was reported in two studies, and the means postoperatively ranged from 94.55 to 97. Postoperative complication rates were low (range, 0% to 20%) and there were no reported incidences of allograft rupture or mechanical failure.

CONCLUSION

Based on the available data, soft tissue allograft for MUCLR in athletic patient populations provides excellent clinical outcomes, high rates of RTP, and low rates of postoperative complications and graft failure at short-term follow-up. There remains a lack of high-quality evidence directly comparing autograft versus allograft outcomes in elite overhead throwing athletes to support allograft as an acceptable alternative for MUCLR in this patient population.

Projected Colorectal Cancer Incidence and Mortality Based on Observed Adherence to Colonoscopy and Sequential Stool-Based Screening

INTRODUCTION

Modeling supporting recommendations for colonoscopy and stool-based colorectal cancer (CRC) screening tests assumes 100% sequential participant adherence. The impact of observed adherence on the long-term effectiveness of screening is unknown. We evaluated the effectiveness of a program of screening colonoscopy every 10 years vs annual high-sensitivity guaiac-based fecal occult blood testing (HSgFOBT) using observed sequential adherence data.

METHODS

The MIcrosimulation SCreening ANalysis (MISCAN) model used observed sequential screening adherence, HSgFOBT positivity, and diagnostic colonoscopy adherence in HSgFOBT-positive individuals from the National Colonoscopy Study (single-screening colonoscopy vs ≥4 HSgFOBT sequential rounds). We compared CRC incidence and mortality over 15 years with no screening or 10 yearly screening colonoscopy vs annual HSgFOBT with 100% and differential observed adherence from the trial.

RESULTS

Without screening, simulated incidence and mortality over 15 years were 20.9 (95% probability interval 15.8-26.9) and 6.9 (5.0-9.2) per 1,000 participants, respectively. In the case of 100% adherence, only screening colonoscopy was predicted to result in lower incidence; however, both tests lowered simulated mortality to a similar level (2.1 [1.6-2.9] for screening colonoscopy and 2.5 [1.8-3.4] for HSgFOBT). Observed adherence for screening colonoscopy (83.6%) was higher than observed sequential HSgFOBT adherence (73.1% first round; 49.1% by round 4), resulting in lower simulated incidence and mortality for screening colonoscopy (14.4 [10.8-18.5] and 2.9 [2.1-3.9], respectively) than HSgFOBT (20.8 [15.8-28.1] and 3.9 [2.9-5.4], respectively), despite a 91% adherence to diagnostic colonoscopy with FOBT positivity. The relative risk of CRC mortality for screening colonoscopy vs HSgFOBT was 0.75 (95% probability interval 0.68-0.80). Findings were similar in sensitivity analyses with alternative assumptions for repeat colonoscopy, test performance, risk, age, and projection horizon.

DISCUSSION

Where sequential adherence to stool-based screening is suboptimal and colonoscopy is accessible and acceptable-as observed in the national colonoscopy study, microsimulation, comparative effectiveness, screening recommendations.

Bornean tropical forests recovering from logging at risk of regeneration failure

Active restoration through silvicultural treatments (enrichment planting, cutting climbers and liberation thinning) is considered an important intervention in logged forests. However, its ability to enhance regeneration is key for long-term recovery of logged forests, which remains poorly understood, particularly for the production and survival of seedlings in subsequent generations. To understand the long-term impacts of logging and restoration we tracked the diversity, survival and traits of seedlings that germinated immediately after a mast fruiting in North Borneo in unlogged and logged forests 30-35 years after logging. We monitored 5119 seedlings from germination for ~1.5 years across a mixed landscape of unlogged forests (ULs), naturally regenerating logged forests (NR) and actively restored logged forests via rehabilitative silvicultural treatments (AR), 15-27 years after restoration. We measured 14 leaf, root and biomass allocation traits on 399 seedlings from 15 species. Soon after fruiting, UL and AR forests had higher seedling densities than NR forest, but survival was the lowest in AR forests in the first 6 months. Community composition differed among forest types; AR and NR forests had lower species richness and lower evenness than UL forests by 5-6 months post-mast but did not differ between them. Differences in community composition altered community-weighted mean trait values across forest types, with higher root biomass allocation in NR relative to UL forest. Traits influenced mortality ~3 months post-mast, with more acquisitive traits and relative aboveground investment favoured in AR forests relative to UL forests. Our findings of reduced seedling survival and diversity suggest long time lags in post-logging recruitment, particularly for some taxa. Active restoration of logged forests recovers initial seedling production, but elevated mortality in AR forests lowers the efficacy of active restoration to enhance recruitment or diversity of seedling communities. This suggests current active restoration practices may fail to overcome barriers to regeneration in logged forests, which may drive long-term changes in future forest plant communities.

Tropical tree ectomycorrhiza are distributed independently of soil nutrients

Mycorrhizae, a form of plant-fungal symbioses, mediate vegetation impacts on ecosystem functioning. Climatic effects on decomposition and soil quality are suggested to drive mycorrhizal distributions, with arbuscular mycorrhizal plants prevailing in low-latitude/high-soil-quality areas and ectomycorrhizal (EcM) plants in high-latitude/low-soil-quality areas. However, these generalizations, based on coarse-resolution data, obscure finer-scale variations and result in high uncertainties in the predicted distributions of mycorrhizal types and their drivers. Using data from 31 lowland tropical forests, both at a coarse scale (mean-plot-level data) and fine scale (20 × 20 metres from a subset of 16 sites), we demonstrate that the distribution and abundance of EcM-associated trees are independent of soil quality. Resource exchange differences among mycorrhizal partners, stemming from diverse evolutionary origins of mycorrhizal fungi, may decouple soil fertility from the advantage provided by mycorrhizal associations. Additionally, distinct historical biogeographies and diversification patterns have led to differences in forest composition and nutrient-acquisition strategies across three major tropical regions. Notably, Africa and Asia's lowland tropical forests have abundant EcM trees, whereas they are relatively scarce in lowland neotropical forests. A greater understanding of the functional biology of mycorrhizal symbiosis is required, especially in the lowland tropics, to overcome biases from assuming similarity to temperate and boreal regions.

Medial elbow injuries in the throwing athlete

There has been an epidemic increase in injuries to the elbow in our youth sports over the past 15 years. Initially, career-ending elbow injuries occurred almost exclusively in the professional population. The landmark procedure developed by Dr. Frank Jobe, colloquially termed "Tommy John surgery" after the initial player in whom he performed the surgical procedure, allowed roughly two-thirds of professional athletes to return to play at or near the same level. As the surgical procedure became more widespread, modifications of the technique by Jobe and many other contributors raised the return-to-play level to 85%-94% of players regaining the ability to return to sport at the preinjury level. Almost simultaneously, the emphasis on velocity in the professional ranks led to an unintentional increase in stress on the throwing elbow. This was magnified in our athletes by the advent of year-round sports, as well as the formation of "showcase" events to demonstrate skills and measure velocity. This, unfortunately, has resulted in an increase in both repetitive stress injuries and acute traumatic injuries in our young athletes. The purpose of this article is to discuss age-related injuries from both a preventative standpoint and a treatment standpoint.

Punctuated equilibrium at 50: Anything there for evolutionary anthropology? Yes; definitely

The theory of punctuated equilibrium (PE) was developed a little over 50 years ago to explain long-term, large-scale appearance and disappearance of species in the fossil record. A theory designed specifically for that purpose cannot be expected, out of the box, to be directly applicable to biocultural evolution, but in revised form, PE offers a promising approach to incorporating not only a wealth of recent empirical research on genetic, linguistic, and technological evolution but also large databases that document human biological and cultural diversity across time and space. Here we isolate the fundamental components of PE and propose which pieces, when reassembled or renamed, can be highly useful in evolutionary anthropology, especially as humanity faces abrupt ecological challenges on an increasingly larger scale.

Protein interaction network revealed by quantitative proteomic analysis links TFIIB to multiple aspects of the transcription cycle

Although TFIIB is widely regarded as an initiation factor, recent reports have implicated it in multiple aspects of eukaryotic transcription. To investigate the broader role of TFIIB in transcription, we performed quantitative proteomic analysis of yeast TFIIB. We purified two different populations of TFIIB; one from soluble cell lysate, which is not engaged in transcription, and the other from the chromatin fraction which yields the transcriptionally active form of the protein. TFIIB purified from the chromatin exhibits several interactions that explain its non-canonical roles in transcription. RNAPII, TFIIF and TFIIH were the only components of the preinitiation complex with a significant presence in chromatin TFIIB. A notable feature was enrichment of all subunits of CF1 and Rat1 3' end processing-termination complexes in chromatin-TFIIB preparation. Subunits of the CPF termination complex were also detected in both chromatin and soluble derived TFIIB preparations. These results may explain the presence of TFIIB at the 3' end of genes during transcription as well as its role in promoter-termination interaction.

Mycorrhizal feedbacks influence global forest structure and diversity

One mechanism proposed to explain high species diversity in tropical systems is strong negative conspecific density dependence (CDD), which reduces recruitment of juveniles in proximity to conspecific adult plants. Although evidence shows that plant-specific soil pathogens can drive negative CDD, trees also form key mutualisms with mycorrhizal fungi, which may counteract these effects. Across 43 large-scale forest plots worldwide, we tested whether ectomycorrhizal tree species exhibit weaker negative CDD than arbuscular mycorrhizal tree species. We further tested for conmycorrhizal density dependence (CMDD) to test for benefit from shared mutualists. We found that the strength of CDD varies systematically with mycorrhizal type, with ectomycorrhizal tree species exhibiting higher sapling densities with increasing adult densities than arbuscular mycorrhizal tree species. Moreover, we found evidence of positive CMDD for tree species of both mycorrhizal types. Collectively, these findings indicate that mycorrhizal interactions likely play a foundational role in global forest diversity patterns and structure.

Global Run-On sequencing to measure nascent transcription in Saccharomyces cerevisiae

Global Run-On sequencing is a reliable and widely used approach for monitoring nascent transcription on a genomewide scale. The assay has been successfully used for studying global transcription in humans, plants, worms, flies, and fission yeast. Here we describe a GRO-seq protocol for studying transcription in budding yeast, Saccharomyces cerevisiae. Briefly, the technique involves permeabilization of actively growing yeast cells, allowing transcription to proceed in permeabilized cells in the presence of brominated UTP, affinity purification of bromo-UMP incorporated nascent transcripts followed by cDNA library construction, deep sequencing, and mapping against the reference genome. The approach maps the position of transcriptionally active RNA polymerase on a genomewide basis. In addition to identifying the complete set of transcriptionally active genes in a cell under a given set of conditions, the method can be used to determine elongation rate, termination defect and promoter directionality at the genomewide level. The approach is especially useful in identifying short-lived unstable transcripts that are rapidly degraded even before they leave the nucleus.

Fixation devices for anterior shoulder instability

PURPOSE

Over the past 40 years, advances in the development of anchors and sutures have contributed to the improvement in surgical outcomes for treatment of shoulder instability. Important choices in surgery when treating instability include the use of knotless versus knotted suture anchors, and bony versus soft tissue reconstruction techniques.

METHODS

A literature review was conducted to evaluate the history of instability of the shoulder and the results of specific fixation techniques including bony and soft tissue reconstructions as well as knotted and knotless suture anchors.

RESULTS

As knotless suture anchors have continued to grow in popularity since their development in 2001, many studies have compared this newer technique to that of the standard knotted suture anchors. In general, these studies have demonstrated no difference in patient-reported outcome measures between the two options. Additionally, the choice of bony versus soft tissue reconstructions is patient specific as it depends on the specific pathology or combination of injuries.

CONCLUSION

In each surgery performed for shoulder instability, it is vitally important that we try to restore normal anatomy. The normal anatomy is best established by knotted mattress sutures. However, loop laxity and tear through by the sutures in the capsule can eliminate this restoration, increasing risk of failure. Knotless anchors may allow better soft tissue fixation of the labrum and capsule to the glenoid, but without complete restoration of normal anatomy.

Randomized Trial of Facilitated Adherence to Screening-Colonoscopy Versus Sequential Fecal-Based Blood Test

BACKGROUND AND AIMS

Colorectal cancer (CRC) screening guidelines include screening-colonoscopy and sequential high sensitivity fecal occult blood testing (HSgFOBT), with expectation of similar effectiveness based on the assumption of similar high adherence. However, adherence to screening-colonoscopy compared to sequential HSgFOBT has not been reported. In this randomized clinical trial, we assessed adherence and pathology findings for a single screening-colonoscopy versus sequential and non-sequential HSgFOBT.

METHODS

Participants aged 40-69 were enrolled in three centers, which represented different clinical settings. Participants were randomized into a single screening-colonoscopy arm versus sequential HSgFOBT arm comprised of 4-7 rounds. Initial adherence to screening-colonoscopy and sequential adherence to HSgFOBT, follow-up colonoscopy for positive HSgFOBT tests, crossover to colonoscopy, and detection of advanced neoplasia or large serrated lesions (ADN-SER) were measured.

RESULTS

3,523 participants were included in the trial with 1761 and 1762 participants randomized to the screening-colonoscopy and HSgFOBT arms, respectively. Adherence was 1473 (83.6%) for the screening-colonoscopy arm versus 1288 (73.1%) for the HSgFOBT arm after one round (RR=1.14, [95% CI 1.10-1.19] P ≤0.001), but only 674 (38.3%) over four sequential HSgFOBT rounds (RR=2.19, [95% CI 2.05-2.33]). Overall adherence to any screening increased to 1558 (88.5%) in the screening-colonoscopy arm during the entire study period and 1493 in the HSgFOBT arm (84.7%) (RR=1.04, [95% CI 1.02-1.07]). 436 (24.7%) participants crossed over to screening-colonoscopy over the first four rounds. ADN-SER were detected in 121 (8.2%) of the 1473 participants in the colonoscopy arm who were adherent to protocol in the first 12 months of the study, whereas the detection of ADN-SER among those who were not sequentially adherent (N=709) to HSgFOBT was subpar (0.6%) (RR=14.72, [95% CI 5.46-39.67]) when compared to those who were sequentially adherent (3.3%) (N=647) (RR=2.52, [95% CI 1.61-3.98]) to HSgFOBT in the first four rounds. When including colonoscopies from HSgFOBT patients who were never positive yet crossed over (N=1483), 5.5% of ADN-SER were detected (RR=1.50, [95% CI 1.15-1.96]) in the first four rounds.

CONCLUSIONS

Observed adherence to sequential rounds of HSgFOBT was suboptimal when compared to a single screening-colonoscopy. The detection of ADN-SER was inferior when non-sequential HSgFOBT adherence was compared to sequential adherence. However, the greatest number of ADN-SER was detected among those who crossed over to colonoscopy and opted to receive a colonoscopy. The effectiveness of a HSgFOBT screening program may be enhanced if crossover to screening-colonoscopy is permitted.

The road to recovery: a synthesis of outcomes from ecosystem restoration in tropical and sub-tropical Asian forests

Current policy is driving renewed impetus to restore forests to return ecological function, protect species, sequester carbon and secure livelihoods. Here we assess the contribution of tree planting to ecosystem restoration in tropical and sub-tropical Asia; we synthesize evidence on mortality and growth of planted trees at 176 sites and assess structural and biodiversity recovery of co-located actively restored and naturally regenerating forest plots. Mean mortality of planted trees was 18% 1 year after planting, increasing to 44% after 5 years. Mortality varied strongly by site and was typically ca 20% higher in open areas than degraded forest, with height at planting positively affecting survival. Size-standardized growth rates were negatively related to species-level wood density in degraded forest and plantations enrichment settings. Based on community-level data from 11 landscapes, active restoration resulted in faster accumulation of tree basal area and structural properties were closer to old-growth reference sites, relative to natural regeneration, but tree species richness did not differ. High variability in outcomes across sites indicates that planting for restoration is potentially rewarding but risky and context-dependent. Restoration projects must prepare for and manage commonly occurring challenges and align with efforts to protect and reconnect remaining forest areas. The abstract of this article is available in Bahasa Indonesia in the electronic supplementary material. This article is part of the theme issue 'Understanding forest landscape restoration: reinforcing scientific foundations for the UN Decade on Ecosystem Restoration'.

How Do The Top 10 Known Offending Drug Classes Associated With Decreased Bone Mineral Density Affect Total Shoulder Arthroplasty Outcomes?

BACKGROUND

Many regularly prescribed classes of drugs are known to negatively impact bone health. However, it is unclear if perioperative use of these drugs impacts total shoulder arthroplasty (TSA) outcomes. The purpose of this study was to analyze the impact of perioperative use of 10 drug classes with known negative effects on bone health on prosthesis-related outcomes of TSA.

METHODS

Patients who underwent primary TSA were retrospectively identified in the PearlDiver database. Within this population, patients prescribed proton pump inhibitors (PPIs), thiazolidinediones (TZDs), loop diuretics, glucocorticoids, aromatase inhibitors, calcineurin inhibitors, selective serotonin inhibitors (SSRIs), antiepileptic drugs (AEDs), first-generation antipsychotics (FGAs), and second-generation antipsychotics (SGAs) within 6 months before or 6 months after primary TSA were identified (n = 23,748). These patients were propensity score matched 1:1 with controls (n = 23,748) on age, sex, and several comorbidities. After matching, patients with perioperative drug exposure were divided into 10 subgroups (i.e., one for each drug class). Rates of prosthesis-related complications among patients taking each medication class versus controls were compared with multivariable logistic regression.

RESULTS

Relative to controls, SGA exposure was associated with significantly higher rates of all cause revision (OR 1.68) and aseptic revision (OR 1.57). Loop diuretic exposure was associated with significantly higher rates of all-cause revision (OR 1.44) and aseptic revision (OR 1.43). Glucocorticoid exposure was associated with significantly higher rates of all-cause revision (OR 1.32) and aseptic revision (OR 1.30). SSRI exposure was associated with significantly higher rates of all-cause revision (OR 1.27) and aseptic revision (OR 1.24). Periprosthetic fracture, aseptic loosening, and septic revision was comparable for all drug cohorts compared to matched controls (all p > 0.05). Patients with perioperative exposure to PPIs, TZDs, FGAs, AEDs, aromatase inhibitors, and calcineurin inhibitors displayed comparable rates of all queried complications compared to controls (all p > 0.05).

CONCLUSION

Compared to matched controls, patients with perioperative exposure to SGAs, loop diuretics, glucocorticoids and SSRIs exhibited significantly higher rates of all-cause and aseptic revisions following primary TSA. Several other medications that are risk factors osteoporosis and fragility fractures did not demonstrate significant associations with any complications, including periprosthetic fracture. These results highlight the need for a thorough review of patients' past medical history and current medication usage prior to preoperative risk counseling for patients seeking TSA.

Demographic consequences of heterogeneity in conspecific density dependence among mast-fruiting tropical trees

The role of conspecific density dependence (CDD) in the maintenance of species richness is a central focus of tropical forest ecology. However, tests of CDD often ignore the integrated effects of CDD over multiple life stages and their long-term impacts on population demography. We combined a 10-year time series of seed production, seedling recruitment and sapling and tree demography of three dominant Southeast Asian tree species that adopt a mast-fruiting phenology. We used these data to construct individual-based models that examine the effects of CDD on population growth rates (λ) across life-history stages. Recruitment was driven by positive CDD for all species, supporting the predator satiation hypothesis, while negative CDD affected seedling and sapling growth of two species, significantly reducing λ. This negative CDD on juvenile growth overshadowed the positive CDD of recruitment, suggesting the cumulative effects of CDD during seedling and sapling development has greater importance than the positive CDD during infrequent masting events. Overall, CDD varied among positive, neutral and negative effects across life-history stages for all species, suggesting that assessments of CDD on transitions between just two stages (e.g. seeds seedlings or juveniles mature trees) probably misrepresent the importance of CDD on population growth and stability.

Comparison of pre-high school and high school football quarterback injuries

OBJECTIVE

To compare the common injuries of pre-high school American football quarterbacks (Pre-HS QBs) and high school American football quarterbacks (HS QBs) within the last 15 years.

METHODS

A retrospective chart review was performed at a sports medicine clinic at a tertiary-level pediatric medical center. Pediatric and adolescent American football quarterback patients who sustained sports-related injuries were extracted. Injury status (acute vs. overuse), injured anatomic locations, injury types, and surgical status were compared by Pre-HS QBs (<14 years old) and HS QBs (14-18 years old).

RESULTS

A total of 121 injuries were found in 118 male Pre-HS QBs (mean age: 12.4 ± 1.6), while 302 injuries were observed in 256 male HS QBs (mean age: 15.8 ± 1.4). Overall, nearly two-third (2/3) of injuries were acute (64.3%) while a little over one-third (1/3) of injuries were overuse in nature (35.7%), and there were no differences between Pre-HS and HS QBs (58.7% vs. 66.7%, p = 0.114). The top 3 injured anatomic locations for Pre-HS QBs were elbow (20.7%), shoulder (18.2%), and head/neck (14.0%). For HS QBs, the top 3 injured anatomic locations were shoulder (24.5%), knee (17.5%), and head/neck (15.2%). There were significant differences in proportion of elbow (20.7% vs. 10.6%, p = 0.006), hip/trunk/upper leg (10.7% vs. 3.3%, p = 0.002), and knee injuries (9.1% vs. 17.5%, p = 0.028) between Pre-HS and HS QBs. Pre-HS QBs had significantly more bony/cartilaginous/labral injuries than their older counterparts (60.3% vs. 46.3%, p = 0.009) while HS QBs experienced significantly more ligamentous injuries than Pre-HS QBs (14.2% vs. 5.8%, p = 0.015).

CONCLUSIONS

QB-associated injuries were distinctively different between Pre-HS and HS QBs. Future studies are warranted to investigate relatively high proportions of elbow injuries as well as bony/cartilaginous/labral injuries found in Pre-HS QBs.

Distribution of biomass dynamics in relation to tree size in forests across the world

Tree size shapes forest carbon dynamics and determines how trees interact with their environment, including a changing climate. Here, we conduct the first global analysis of among-site differences in how aboveground biomass stocks and fluxes are distributed with tree size. We analyzed repeat tree censuses from 25 large-scale (4-52 ha) forest plots spanning a broad climatic range over five continents to characterize how aboveground biomass, woody productivity, and woody mortality vary with tree diameter. We examined how the median, dispersion, and skewness of these size-related distributions vary with mean annual temperature and precipitation. In warmer forests, aboveground biomass, woody productivity, and woody mortality were more broadly distributed with respect to tree size. In warmer and wetter forests, aboveground biomass and woody productivity were more right skewed, with a long tail towards large trees. Small trees (1-10 cm diameter) contributed more to productivity and mortality than to biomass, highlighting the importance of including these trees in analyses of forest dynamics. Our findings provide an improved characterization of climate-driven forest differences in the size structure of aboveground biomass and dynamics of that biomass, as well as refined benchmarks for capturing climate influences in vegetation demographic models.

Management of Posttraumatic Avascular Necrosis of the Proximal Humerus

The etiology of avascular necrosis (AVN) of the proximal humerus can be classified as idiopathic or posttraumatic, the latter being mainly due to proximal humerus fractures. Evidence suggests that posttraumatic AVN may require surgical intervention more often than idiopathic AVN of the proximal humerus. This article provides a comprehensive review of the management of posttraumatic AVN of the proximal humerus. Early stage AVN (stages 1 to 3) is commonly treated with nonoperative intervention or core decompression of the humeral head, whereas later stage disease (stages 4 and 5) may require hemiarthroplasty or total shoulder arthroplasty to restore function. [Orthopedics. 2021;44(6):367-375.].

Prophylaxis for Heterotopic Ossification Following Distal Biceps Tendon Repair

Heterotopic ossification (HO) is a possible complication of distal biceps tendon repair (DBTR). Several agents can prevent HO formation, although relatively few studies have investigated prophylaxis specifically after DBTR. The purposes of this study were to survey members of the American Shoulder and Elbow Surgeons (ASES) to determine (1) what percentage use HO prophylaxis after DBTR; (2) type, dosage, and duration of prophylaxis used; and (3) use of single-incision or double-incision surgical technique. An anonymous electronic survey was distributed to ASES members to determine the use of HO prophylaxis and DBTR technique. The survey included questions regarding the number of DBTRs performed annually; preferred surgical technique and implants; and type, dosage, and duration of HO prophylaxis used before, during, and after surgery. Descriptive statistics were used to analyze the results. Of 173 respondents, 98 (56.6%) performed 1 to 10 DBTRs per year, 65 (37.6%) performed 11 to 25 DBTRs per year, and 10 (5.8%) performed 26 to 50 DBTRs per year. A total of 131 (75.7%) preferred the single-incision technique, whereas 42 (24.3%) preferred the double-incision technique. A total of 94 (54.3%) performed DBTR using a metal button and interference screw, 35 (20.2%) through drill holes, 25 (14.5%) with suture anchors, and 19 (11.0%) with a metal button alone. A total of 132 (76.3%) respondents did not use HO prophylaxis, and 41 (23.7%) used nonsteroidal anti-inflammatory drugs following surgery. A total of 35 (85.4%) used indomethacin, 18 (51.4%) of whom preferred 75 mg/d for 3 to 4 weeks. Heterotopic ossification is a commonly reported complication following DBTR, especially with the double-incision technique. Prophylaxis with anti-inflammatory medications and suppressive modalities (radiation therapy) appear to reduce the incidence of HO. Despite these data, most surgeons (76.3%) do not use HO prophylaxis. Low annual volume of cases, lack of large-volume studies with outcome data, and the dominant use of the single-incision repair technique may explain this. [Orthopedics. 2021;44(4):e588-e592.].

The genome of Shorea leprosula (Dipterocarpaceae) highlights the ecological relevance of drought in aseasonal tropical rainforests

Hyperdiverse tropical rainforests, such as the aseasonal forests in Southeast Asia, are supported by high annual rainfall. Its canopy is dominated by the species-rich tree family of Dipterocarpaceae (Asian dipterocarps), which has both ecological (e.g., supports flora and fauna) and economical (e.g., timber production) importance. Recent ecological studies suggested that rare irregular drought events may be an environmental stress and signal for the tropical trees. We assembled the genome of a widespread but near threatened dipterocarp, Shorea leprosula, and analyzed the transcriptome sequences of ten dipterocarp species representing seven genera. Comparative genomic and molecular dating analyses suggested a whole-genome duplication close to the Cretaceous-Paleogene extinction event followed by the diversification of major dipterocarp lineages (i.e. Dipterocarpoideae). Interestingly, the retained duplicated genes were enriched for genes upregulated by no-irrigation treatment. These findings provide molecular support for the relevance of drought for tropical trees despite the lack of an annual dry season.

Association between post-concussion symptoms and oculomotor deficits among adolescents

PURPOSE

To examine the association between Post-Concussion Symptom Scale (PCSS) scores, Convergence Insufficiency Symptom Survey (CISS) scores, and oculomotor deficits post-concussion.

METHODS

Records of adolescent patients examined in a multidisciplinary concussion clinic between July 2014 and May 2019 were reviewed. PCSS and CISS scores, results of eye examination and oculomotor assessment, concussion history, and demographics were abstracted.

RESULTS

One hundred and forty patient records (median age, 15.3 years; 52 males, presented 109 days (median) from their most recent concussion) met inclusion criteria. Mean total scores on PCSS and CISS were 46.67 ± 25.89 and 27.13 ± 13.22, respectively, and were moderately correlated with each other (r = 0.53, p < .001). Oculomotor deficits were observed in 123 (88%) patients. Step-wise linear regression identified increased PCSS total score to be significantly associated with decreased amplitude of accommodation (p < .001). Increased CISS total score was significantly associated with receded near point of convergence, developmental eye movement test error scores, and cause of concussion.

CONCLUSION

High PCSS scores may indicate an accommodation deficit and thus prompt an oculomotor assessment in patients following a concussion. Using the CISS and a detailed oculomotor assessment may reveal underlying oculomotor deficits, which may benefit from treatment.

Editorial Commentary: Shoulder Biceps Tenotomy Versus Tenodesis Surgical Decision Making Must be Individualized for Each Patient

The optimal treatment for proximal biceps tendon lesions identified at the time of arthroscopic rotator cuff repair remains a topic for debate. The decision between biceps tenotomy and tenodesis is one in which we will likely never have a clear-cut answer. Proponents of biceps tenotomy and biceps tenodesis will cite the pros and cons of each surgical option to support their treatment of choice. Several meta-analyses have shown no superior outcomes with either treatment. Cost analysis and surgical efficiency may favor biceps tenotomy, whereas the possible development of a Popeye deformity, biceps cramping, and supination strength favor tenodesis. The surgical treatment of choice requires an informed discussion and shared decision making between surgeon and patient to determine patients' expectations and maximize surgical outcomes for each individual patient.

Genetics of canine myxomatous mitral valve disease

Myxomatous mitral valve disease (MMVD) is the most common heart disease and cause of cardiac death in domestic dogs. MMVD is characterised by slow progressive myxomatous degeneration from the tips of the mitral valves onwards with subsequent mitral valve regurgitation, and left atrial and ventricular dilatation. Although the disease usually has a long asymptomatic period, in dogs with severe disease, mortality is typically secondary to left-sided congestive heart failure. Although it is not uncommon for dogs to survive long enough in the asymptomatic period to die from unrelated causes; a proportion of dogs rapidly advance into congestive heart failure. Heightened prevalence in certain breeds, such as the Cavalier King Charles Spaniel, has indicated that MMVD is under a genetic influence. The genetic characterisation of the factors that underlie the difference in progression of disease is of strong interest to those concerned with dog longevity and welfare. Advanced genomic technologies have the potential to provide information that may impact treatment, prevalence, or severity of MMVD through the elucidation of pathogenic mechanisms and the detection of predisposing genetic loci of major effect. Here we describe briefly the clinical nature of the disorder and consider the physiological mechanisms that might impact its occurrence in the domestic dog. Using results from comparative genomics we suggest possible genetic approaches for identifying genetic risk factors within breeds. The Cavalier King Charles Spaniel breed represents a robust resource for uncovering the genetic basis of MMVD.

"Current concepts and expert practice report: Augmentation of rotator cuff repairs"

Rotator cuff tears are common shoulder injuries expected to increase with the growth of the aging population. Although a small subset of patients with low functional demands can be treated nonoperatively, surgical intervention is a cost-effective solution, which can restore shoulder function and help patients return to activity sooner. While multiple surgical options are available, rotator cuff repair is a highly utilized procedure with varying success. Due to a large proportion of rotator cuff repairs still failing to completely heal, this procedure requires careful planning to achieve anatomical and biomechanically stability. New technology and techniques are being explored to help increase the success of rotator cuff repairs with an increasing focus on augmentation. The current article gives a brief overview of pertinent anatomy, treatment options, and challenges in healing of rotator cuff repairs. Thereafter, the merits of different types of rotator cuff repair augmentation available will be discussed as well as the authors' experience in utilizing biologic augmentation and surgical technique.

Critical Involvement of TFIIB in Viral Pathogenesis

Viral infections and the harm they cause to their host are a perpetual threat to living organisms. Pathogenesis and subsequent spread of infection requires replication of the viral genome and expression of structural and non-structural proteins of the virus. Generally, viruses use transcription and translation machinery of the host cell to achieve this objective. The viral genome encodes transcriptional regulators that alter the expression of viral and host genes by manipulating initiation and termination steps of transcription. The regulation of the initiation step is often through interactions of viral factors with gene specific factors as well as general transcription factors (GTFs). Among the GTFs, TFIIB (Transcription Factor IIB) is a frequent target during viral pathogenesis. TFIIB is utilized by a plethora of viruses including human immunodeficiency virus, herpes simplex virus, vaccinia virus, Thogoto virus, hepatitis virus, Epstein-Barr virus and gammaherpesviruses to alter gene expression. A number of viral transcriptional regulators exhibit a direct interaction with host TFIIB in order to accomplish expression of their genes and to repress host transcription. Some viruses have evolved proteins with a three-dimensional structure very similar to TFIIB, demonstrating the importance of TFIIB for viral persistence. Upon viral infection, host transcription is selectively altered with viral transcription benefitting. The nature of viral utilization of TFIIB for expression of its own genes, along with selective repression of host antiviral genes and downregulation of general host transcription, makes TFIIB a potential candidate for antiviral therapies.

Species packing and the latitudinal gradient in beta-diversity

The decline in species richness at higher latitudes is among the most fundamental patterns in ecology. Whether changes in species composition across space (beta-diversity) contribute to this gradient of overall species richness (gamma-diversity) remains hotly debated. Previous studies that failed to resolve the issue suffered from a well-known tendency for small samples in areas with high gamma-diversity to have inflated measures of beta-diversity. Here, we provide a novel analytical test, using beta-diversity metrics that correct the gamma-diversity and sampling biases, to compare beta-diversity and species packing across a latitudinal gradient in tree species richness of 21 large forest plots along a large environmental gradient in East Asia. We demonstrate that after accounting for topography and correcting the gamma-diversity bias, tropical forests still have higher beta-diversity than temperate analogues. This suggests that beta-diversity contributes to the latitudinal species richness gradient as a component of gamma-diversity. Moreover, both niche specialization and niche marginality (a measure of niche spacing along an environmental gradient) also increase towards the equator, after controlling for the effect of topographical heterogeneity. This supports the joint importance of tighter species packing and larger niche space in tropical forests while also demonstrating the importance of local processes in controlling beta-diversity.

Implant-Free Subpectoral Biceps Tenodesis Is Biomechanically at Higher Risk of Spiral Fracture of the Humerus Compared With Implant-Free Suprapectoral Biceps Tenodesis

Purpose

To compare the likelihood of spiral fracture of the humerus using torsional load to failure after intraosseous biceps tenodesis at the position of the arthroscopic suprapectoral tenodesis versus the subpectoral meta-diaphyseal location.

Methods

Eight matched pairs of humeri were dissected. Unicortical tenodesis holes were drilled, either at the bottom of the bicipital groove (group 1) or just below the pectoralis major tendon insertion (subpectoral) in the humeral diaphysis (group 2). Tenodesis was performed in a 7-mm bone tunnel, with suture fixation distal to this site using 2 separate 2-mm holes, secured with No. 2 polyester suture. Each humerus was potted in plaster and mounted to a hydraulic torsional load frame, consistent with previously validated models for creating humeral spiral fractures. External rotation torque was applied to each humerus distally until fracture occurred. The paired t test was used to compare the 2 groups.

Results

Fracture occurred at the subpectoral cortical drill hole in all 8 specimens in group 2. In group 1, only 2 fractures occurred through the tenodesis hole, with spiral fracture resulting in the diaphysis of the humerus in 6 of 8 specimens. Average torque to failure measured 31.35 Nm in group 1 and 25.08 Nm in group 2; the difference was statistically significant (P < .0001).

Conclusions

Subpectoral cortical drill holes for biceps tenodesis were shown to be a stress riser for humeral spiral fracture. Suprapectoral cortical drill holes were shown to be significantly less of a stress riser. The amount of torque required to fracture the humerus through the subpectoral drill holes was less than with the suprapectoral drill holes. Only 2 fractures occurred through the suprapectoral tenodesis holes, and significantly more torque was required to create these fractures.

Clinical Relevance

Clinically, the difference between suprapectoral and subpectoral tenodesis fracture potential should be considered when selecting a tenodesis location.

Traumatic Elbow Instability: How to Fix It and When to Phone a Friend

Traumatic elbow instability is a difficult condition to manage. Many surgeons consider the elbow a perplexing black box and evaluating damaged structures in the setting of pain and swelling a diagnostic challenge. Injury most commonly occurs from a fall onto an outstretched hand but also results from elbow dislocation, direct trauma, and sporting activities. The injury can initiate on the medial or lateral side, depending on forearm position at the time of injury, and usually follows a predictable pattern, with progressive instability caused by soft-tissue disruption and fractures of the medial or lateral column. Primary medial instability, lateral instability, and 
combined injury patterns have been described and discussed. Simple elbow dislocations and certain fractures can be managed nonsurgically, whereas complex patterns of instability and fracture-dislocations routinely require surgery. Stiffness and nerve injury are the most common complications and occur from both surgical and nonsurgical management. This chapter describes the diagnosis and management of traumatic elbow instability and the management of its sequela.

Medical Therapies for Concussion

The medications used in postconcussion syndrome are typically used to help manage or minimize disruptive symptoms while recovery proceeds. These medications are not routinely used in most concussions that recover within days to weeks. However, it is beneficial to be aware of medication options that may be used in athletes with prolonged concussion symptoms or for those that have symptom burdens that preclude entry into basic concussion protocols. Medications and supplements remain a small part of the concussion treatment plan, which may include temporary academic adjustments, physical therapy, vestibular and ocular therapy, psychological support, and graded noncontact exercise.

Youth American football quarterback injuries: a descriptive study of 15 years of retrospective data

Objectives: To describe common injuries of youth American football quarterbacks (QBs) cared for in a regional sports medicine center within the last 15 years. Methods: A retrospective chart review of all male youth American football QB patients who sustained sports-related injuries at a regional pediatric medical center between 01/01/2003 and 10/01/2018. Patients were identified using HoundDog to search the term 'quarterback.' Records were then reviewed to identify all male QBs ≤ 18 years of age. Injures that were not a result of football participation were excluded. Main outcome variables were injured anatomic locations, injury types, surgical status, and settings in which the injury was sustained. Descriptive statistics were used to analyze the outcome variables. Results: A total of 374 QBs (mean age: 14.6 ± 2.1) sustained a total of 423 injuries. The top 5 injured anatomic locations were shoulder (22%), knee (15%) head/neck (14%), elbow (13%), and wrist/hand/lower arm (11%). Most injuries (64.3%) were acute; 35.7% were chronic in nature. Most acute injuries (55.5%) occurred during games. Of the chronic injuries, 47.0% occurred during off-season and 34.4% occurred in-season. Among all injuries, 22.9% were surgical cases, and the top 3 anatomic locations of surgery were knee (35.0%), shoulder (20.7%), and elbow (18.7%). Conclusions: The shoulder is the most commonly injured body part among young QBs seeking care in a regional pediatric medical center, although the knee is the most commonly injured body part that requires surgery. Most QB injuries are acute in mechanism and the majority of these acute injuries occur during games.

Restoring Horizontal Stability of the Acromioclavicular Joint: Open Acromioclavicular Ligament Reconstruction and Repair With Semitendinosus Allograft

Injuries to the acromioclavicular (AC) joint are common and comprise ∼12% of shoulder injuries. Stability to the AC joint depends on the coracoclavicular (CC) ligaments for vertical stability and AC ligaments and capsular structures for horizontal stability. Injuries to the AC ligaments can lead to horizontal instability of the AC joint. There is no gold standard technique for treating these injuries surgically, and many of the described procedures focus on vertical instability rather than horizontal instability. This article describes an open AC ligament reconstruction with semitendinosus allograft to restore horizontal stability of the AC joint.

Genes, culture, and the human niche: An overview

The sharp distinction between biological traits and culturally based traits, which had long been standard in evolutionary approaches to behavior, was blurred in the early 1980s by mathematical models that allowed a co-dependent evolution of genetic transmission and cultural information. Niche-construction theory has since added another contrast to standard evolutionary theory, in that it views niche construction as a cause of evolutionary change rather than simply a product of selection. While offering a new understanding of the coevolution of genes, culture, and human behavior, niche-construction models also invoke multivariate causality, which require multiple time series to resolve. The empirical challenge lies in obtaining time-series data on causal pathways involved in the coevolution of genes, culture, and behavior. This is a significant issue in archeology, where time series are often sparse and causal behaviors are represented only by proxies in the material record.

The extended evolutionary synthesis and human origins: Archaeological perspectives

Recent developments in evolutionary biology have led to a call for an extension of standard evolutionary theory, with its emphasis on processes such as selection and drift, into a much larger theoretical framework that includes processes such as niche construction, developmental plasticity, inclusive inheritance, and developmental bias. Skeptics argue that these processes are already subsumed within the standard theory and thus an extension is not required. Here, we outline what this evolutionary "rethink" might mean for the study of human origins. Specifically, can paleoanthropologists benefit from an extended theoretical toolkit? The papers in this special issue suggest it can be useful but may not be necessary, depending on the kinds of questions that are being asked.

Platelet-Rich Plasma Is an Equal Alternative to Surgery in the Treatment of Type 1 Medial Epicondylitis

Background:

Medial epicondylitis (ME) is characterized as an overuse injury resulting in pathological alterations of the common flexor tendon at the elbow. Platelet-rich plasma (PRP) has recently become of interest in the treatment of musculoskeletal conditions as an alternative to operative management.

Purpose:

To compare the outcomes of recalcitrant type 1 ME after treatment with either PRP or surgery.

Study Design:

Cohort study; Level of evidence, 3.

Methods:

To compare the 2 methods of treatment, we performed a retrospective review of 33 patients diagnosed with type 1 ME from 2006 to 2016 with a minimum clinical follow-up of 1 year who had failed an initial nonoperative treatment program of injections, medication, topical creams, and/or physical therapy. Overall, 15 patients were treated with a series of 2 leukocyte-rich PRP injections, and 18 patients were treated with surgery. Outcome measures included time to pain-free status, time to full range of motion (ROM), the Mayo Elbow Performance Score (MEPS), and the Oxford Elbow Score (OES). Each patient had at least 1-year follow-up. They were then contacted by telephone to determine final scores at a minimum 2-year follow-up. Unsuccessful outcomes were determined by the Nirschl grading system and failure to reach pain-free status, achieve baseline ROM, or return to previous activity.

Results:

The mean final follow-up was 3.9 years. A statistically significant improvement was noted in both time to full ROM (42.3 days for PRP vs 96.1 days for surgery; P < .01) and time to pain-free status (56.2 days for PRP vs 108.0 days for surgery; P < .01). Successful outcomes were observed in 80% of patients treated with PRP and 94% of those treated operatively (P = .37). No significant difference was found in return-to-activity rates, overall successful outcomes, MEPS scores, or OES scores.

Conclusion:

In this case series, the use of PRP showed clinically similar outcomes to those of surgery in recalcitrant type 1 ME. PRP can be considered as an alternative to surgery in the treatment of recurrent ME, with an earlier time to full ROM and time to pain-free status compared with surgery.

Continuing Play, Symptom Severity, and Symptom Duration After Concussion in Youth Athletes

OBJECTIVE

To determine whether continuing to play after a concussion is associated with higher symptom burden or prolonged symptom duration.

DESIGN

Patients who presented for care at a sport concussion clinic within the first 3 weeks of injury were asked whether they continued to play immediately after their injury.

SETTING

Sport concussion clinic within a regional tertiary care hospital.

MAIN OUTCOME MEASURES

Clinical outcomes including symptom severity, symptom duration, age, time from injury-clinical presentation, sex, sport type, previous concussion history, and whether or not they experienced loss of consciousness or amnesia at the time of injury were recorded. Univariable comparisons between those who did and did not report continuing play were conducted. Multivariable linear regression models were constructed to identify the independent association of continuing to play postinjury with symptom burden and symptom recovery time, while controlling for the effect of potential confounding variables.

RESULTS

A total of 516 patients were included in the study, assessed a mean of 12.1 ± 5.2 days postinjury (35% female, mean age = 14.5 ± 2.3 years). A total of 227 (44%) continued play after sustaining a concussion. Continuing to play postconcussion was independently associated with higher symptom severity during the initial clinical evaluation [β-coefficient = 6.144, 95% confidence interval (CI), 1.357-10.93], but not with symptom duration evaluation (β-coefficient = 1.794, 95% CI, -15.66 to 19.25).

CONCLUSION

Those who continued to play postconcussion presented with more severe symptoms after injury. Recognition of suspected concussion and removal from play on diagnosis confirmation may lead to better initial clinical outcomes after concussion among child and adolescent athletes.

Physical Activity Following Hip Arthroscopy in Young and Middle-Aged Adults: A Systematic Review

Background

Hip arthroscopy is a common surgical intervention for young and middle-aged adults with hip-related pain and dysfunction, who have high expectations for returning to physical activity following surgery. The purpose of this review was to evaluate the impact of hip arthroscopy on physical activity post-arthroscopy.

Methods

A systematic search of electronic databases was undertaken in identifying studies from January 1st 1990 to December 5th 2019. The search included English language articles reporting physical activity as an outcome following hip arthroscopy in adults aged 18-50 years. Quality assessment, data extraction and synthesis of included studies were undertaken.

Results

Full text articles (n = 234) were assessed for eligibility following screening of titles and abstracts (n = 2086), yielding 120 studies for inclusion. The majority (86%) of the studies were level 4 evidence. One study reported objective activity data. The most frequently occurring patient-reported outcome measure was the Hip Outcome Score-sport-specific subscale (HOS-SS, 84% of studies). Post--arthroscopy improvement was indicated by large effect sizes for patient-reported outcome measures (standard paired difference [95% confidence interval] −1.35[−1.61 to −1.09] at more than 2 years post-arthroscopy); however, the majority of outcome scores for the HOS-SS did not meet the defined level for a patient-acceptable symptom state.

Conclusion

The current level of available information regarding physical activity for post arthroscopy patients is limited in scope. Outcomes have focused on patients’ perceived difficulties with sport-related activities with a paucity of information on the type, quality and quantity of activity undertaken.

Level of Evidence

Level IV, systematic review of Level 2 through to Level 4 studies

Double-Row Repair for Recalcitrant Medial Epicondylitis

Background:

Various techniques have been described for surgical treatment of recalcitrant medial epicondylitis (ME). No single technique has yet to be proven the most effective.

Purpose:

To evaluate the clinical outcomes of a double-row repair for ME.

Study Design:

Case series; Level of evidence, 4.

Methods:

A retrospective review was performed on 31 consecutive patients (33 elbows) treated surgically for ME with a minimum clinical follow-up of 2 years. All patients were initially managed nonoperatively with anti-inflammatories, steroid injections, topical creams, and physical therapy. Outcome measures at final follow-up included visual analog scale (VAS) scores (scale, 0-10), time to completely pain-free state, time to full range of motion (FROM), Mayo Elbow Performance Scores (MEPS), and Oxford Elbow Scores (OES). Patients were contacted by telephone to determine current functional outcomes, pain, activity, functional limitations, and MEPS/OES. Successful and unsuccessful outcomes were determined by the Nirschl grading system.

Results:

The mean clinical and telephone follow-up periods were 2.3 and 3.6 years, respectively, and 31 of 33 (94%) elbows were found to have a successful outcome. The mean VAS improvement was 4.9 points, from 5.8 preoperatively to 0.9 postoperatively (P < .001). The mean MEPS and OES at final follow-up were 95.1 and 45.3, respectively. The mean time to pain-free state and time to FROM were 87.4 and 96 days, respectively. Unlike prior studies, no difference in outcome was found between those with and without ulnar neuritis preoperatively (P = .67).

Conclusion:

A double-row repair is effective in decreasing pain and improving the overall function for recalcitrant ME. Uniquely, the presence of preoperative ulnar neuritis was associated with higher patient-reported preoperative pain scores but not with poor outcomes using this protocol.

RNA polymerase II plays an active role in the formation of gene loops through the Rpb4 subunit

Gene loops are formed by the interaction of initiation and termination factors occupying the distal ends of a gene during transcription. RNAPII is believed to affect gene looping indirectly owing to its essential role in transcription. The results presented here, however, demonstrate a direct role of RNAPII in gene looping through the Rpb4 subunit. 3C analysis revealed that gene looping is abolished in the rpb4Δ mutant. In contrast to the other looping-defective mutants, rpb4Δ cells do not exhibit a transcription termination defect. RPB4 overexpression, however, rescued the transcription termination and gene looping defect of sua7-1, a mutant of TFIIB. Furthermore, RPB4 overexpression rescued the ssu72-2 gene looping defect, while SSU72 overexpression restored the formation of gene loops in rpb4Δ cells. Interestingly, the interaction of TFIIB with Ssu72 is compromised in rpb4Δ cells. These results suggest that the TFIIB-Ssu72 interaction, which is critical for gene loop formation, is facilitated by Rpb4. We propose that Rpb4 is promoting the transfer of RNAPII from the terminator to the promoter for reinitiation of transcription through TFIIB-Ssu72 mediated gene looping.

Rating news claims: Feature selection and evaluation

News claims that travel the Internet and online social networks (OSNs) originate from different, sometimes unknown sources, which raises issues related to the credibility of those claims and the drivers behind them. Fact-checking websites such as Snopes, FactCheck, and Emergent use human evaluators to investigate and label news claims, but the process is labor- and time-intensive. Driven by the need to use data analytics and algorithms in assessing the credibility of news claims, we focus on what can be generalized about evaluating human-labeled claims. We developed tools to extract claims from Snopes and Emergent and used public datasets collected by and published on those websites. Claims extracted from those datasets were supervised or labeled with different claim ratings. We focus on claims with definite ratings-false, mostly false, true, and mostly true, with the goal of identifying distinctive features that can be used to distinguish true from false claims. Ultimately, those features can be used to predict future unsupervised or unlabeled claims. We evaluate different methods to extract features as well as different sets of features and their ability to predict the correct claim label. By far, we noticed that OSN websites report high rates of false claims in comparison with most of the other website categories. The rate of reported false claims is higher than the rate of true claims in fact-checking websites in most categories. At the content-analysis level, false claims tend to have more negative tones in sentiments and hence can provide supporting features to predict claim classification.

Algorithm for Reliable Detection of Pulse Onsets in Cerebral Blood Flow Velocity Signals

Transcranial Doppler (TCD) ultrasound has been demonstrated to be a valuable tool for assessing cerebral hemodynamics via measurement of cerebral blood flow velocity (CBFV), with a number of established clinical indications. However, CBFV waveform analysis depends on reliable pulse onset detection, an inherently difficult task for CBFV signals acquired via TCD. We study the application of a new algorithm for CBFV pulse segmentation, which locates pulse onsets in a sequential manner using a moving difference filter and adaptive thresholding. The test data set used in this study consists of 92,012 annotated CBFV pulses, whose quality is representative of real world data. On this test set, the algorithm achieves a true positive rate of 99.998% (2 false negatives), positive predictive value of 99.998% (2 false positives), and mean temporal offset error of 6.10 ± 4.75 ms. We do note that in this context, the way in which true positives, false positives, and false negatives are defined caries some nuance, so care should be taken when drawing comparisons to other algorithms. Additionally, we find that 97.8% and 99.5% of onsets are detected within 10 and 30 ms, respectively, of the true onsets. The algorithm's performance in spite of the large degree of variation in signal quality and waveform morphology present in the test data suggests that it may serve as a valuable tool for the accurate and reliable identification of CBFV pulse onsets in neurocritical care settings.

Above and beyond: holographic tracking of axial displacements in holographic optical tweezers

How far a particle moves along the optical axis in a holographic optical trap is not simply dictated by the programmed motion of the trap, but rather depends on an interplay of the trap's changing shape and the particle's material properties. For the particular case of colloidal spheres in optical tweezers, holographic video microscopy reveals that trapped particles tend to move farther along the axial direction than the traps that are moving them and that different kinds of particles move by different amounts. These surprising and sizeable variations in axial placement can be explained by a dipole-order theory for optical forces. Their discovery highlights the need for real-time feedback to achieve precise control of colloidal assemblies in three dimensions and demonstrates that holographic microscopy can meet that need.

Double Row-Equivalent PASTA Repair Technique

Articular surface partial rotator cuff tendon tears are a common source of shoulder pain and dysfunction, and there is no consensus regarding the optimal arthroscopic treatment. Commonly accepted techniques, such as transtendinous repair or tear takedown with primary repair, may violate healthy tendon tissue and increase the suture anchor density. In this note, we describe an outside-in double row-equivalent technique for repair of partial articular-sided rotator cuff tears. A medial row of inverted horizontal mattress stitches is placed percutaneously using spinal needles to shuttle partially absorbable braided sutures into the joint. The technique may incorporate a soft tissue biceps tenodesis into the rotator cuff with a second, oblique medial row mattress stitch. Suture limbs are retrieved and tied in the subacromial space and then secured to a lateral anchor. The result is a side-to-side double row-equivalent rotator cuff repair, anatomically reproducing the footprint of the rotator cuff without removing healthy tissue. We believe this is an efficient and reproducible technique that preserves intact bursal tissue, limits implant costs, and produces reliable healing in partial articular-sided tears of the rotator cuff.