Genomes shed light on the evolution of Begonia, a mega-diverse genus.

Clarifying the evolutionary processes underlying species diversification and adaptation is a key focus of evolutionary biology. Begonia (Begoniaceae) is one of the most species-rich angiosperm genera with c. 2000 species, most of which are shade-adapted. Here, we present chromosome-scale genome assemblies for four species of Begonia (B. loranthoides, B. masoniana, B. darthvaderiana and B. peltatifolia), and whole genome shotgun data for an additional 74 Begonia representatives to investigate lineage evolution and shade adaptation of the genus. The four genome assemblies range in size from 331.75 Mb (B. peltatifolia) to 799.83 Mb (B. masoniana), and harbor 22 059-23 444 protein-coding genes. Synteny analysis revealed a lineage-specific whole-genome duplication (WGD) that occurred just before the diversification of Begonia. Functional enrichment of gene families retained after WGD highlights the significance of modified carbohydrate metabolism and photosynthesis possibly linked to shade adaptation in the genus, which is further supported by expansions of gene families involved in light perception and harvesting. Phylogenomic reconstructions and genomics studies indicate that genomic introgression has also played a role in the evolution of Begonia. Overall, this study provides valuable genomic resources for Begonia and suggests potential drivers underlying the diversity and adaptive evolution of this mega-diverse clade.

Evolution of endemism on a young tropical mountain.

Tropical mountains are hot spots of biodiversity and endemism, but the evolutionary origins of their unique biotas are poorly understood. In varying degrees, local and regional extinction, long-distance colonization, and local recruitment may all contribute to the exceptional character of these communities. Also, it is debated whether mountain endemics mostly originate from local lowland taxa, or from lineages that reach the mountain by long-range dispersal from cool localities elsewhere. Here we investigate the evolutionary routes to endemism by sampling an entire tropical mountain biota on the 4,095-metre-high Mount Kinabalu in Sabah, East Malaysia. We discover that most of its unique biodiversity is younger than the mountain itself (6 million years), and comprises a mix of immigrant pre-adapted lineages and descendants from local lowland ancestors, although substantial shifts from lower to higher vegetation zones in this latter group were rare. These insights could improve forecasts of the likelihood of extinction and 'evolutionary rescue' in montane biodiversity hot spots under climate change scenarios.

Recurrence of Melanoma After a Negative Sentinel Node Biopsy: Predictors and Impact of Recurrence Site on Survival.

BACKGROUND: Factors that predict melanoma recurrence after a negative sentinel lymph node biopsy (SLNB) are not well-defined. We evaluated melanoma recurrence patterns, factors prognostic for recurrence, and the impact of recurrence on outcomes after a negative SLNB. METHODS: The Sentinel Lymph Node Working Group database was evaluated from 1996 to 2016 for negative SLNB melanoma patients. Clinicopathologic characteristics were correlated with recurrence, overall survival (OS), and melanoma-specific survival (MSS). RESULTS: Median follow-up was 32.1 months. Recurrences developed in 558 of 5351 negative SLN patients (10.4%). First-site of recurrence included a local or in-transit recurrence (LITR) in 221 cases (4.1%), nodal recurrence (NR) in 109 cases (2%), and distant recurrence (DR) in 220 cases (4.1%). On multivariable analysis, age, thickness, head/neck or lower extremity primary, and microsatellitosis significantly predicted for an LITR as first-site. Having an LITR as first-site significantly predicted for a subsequent NR and DR, and significantly predicted for worse OS and MSS. Furthermore, thickness and head/neck or lower extremity primary significantly predicted for an NR as first-site, while a prior LITR significantly predicted for a subsequent NR. Factors significantly predictive for a DR included thickness, head/neck or trunk primary, ulceration, and lymphovascular invasion. Patients with any type of locoregional recurrence were at higher risk for a DR. CONCLUSIONS: Recurrences occur in 10.4% of negative SLN patients, with LITR and DR being the most common types. Importantly, having an LITR significantly predicts for a subsequent NR and DR, and is prognostic for worse survival after a negative SLNB.

Gene tree discordance and coalescent methods support ancient intergeneric hybridisation between Dasymaschalon and Friesodielsia (Annonaceae).

Although hybridisation between closely related species is common and known to be important in plant evolution, hybridisation at the generic level or above is comparatively rare. We address ancient intergeneric hybridisation in the early-divergent angiosperm family Annonaceae by phylogenetic reconstruction, divergence time estimation and coalescent simulation of the genus Dasymaschalon using a multi-locus approach based on molecular data from five chloroplast (matK, psbA-trnH, ndhF, rbcL, and trnL-F) and five nuclear (ITS, ETS, AP3, PhyA, and PhyC) DNA markers. We demonstrate incongruence among different gene trees: Dasymaschalon is retrieved as monophyletic in the nuclear ribosomal tree (based on ITS and ETS), but is non-monophyletic in the chloroplast and Phy-gene trees (with poor resolution in the AP3 tree), with the majority of species assigned to a strongly supported clade but three species (D. filipes, D. longiflorum and D. tibetense) more closely related to the sister genus Friesodielsia. Three contrasting approaches-a coalescent method based on molecular dating, incongruence pattern comparison, and a multi-accession phylogenetic reconstruction-are used to assess the patterns of this gene tree incongruence and test hypotheses of ancient hybridisation and incomplete lineage sorting. Our results support a late Miocene intergeneric hybridisation between members of the Dasymaschalon and Friesodielsia lineages in continental Asia-west Malesia.

The Significance of Upfront Knowledge of N2 Disease in Non-small Cell Lung Cancer.

BACKGROUND: Previous literature suggests that patients with non-small cell lung cancer (NSCLC) and unsuspected N2 disease (cN0, pN2) represent a distinct subgroup associated with improved overall survival compared to patients with N2 disease identified prior to resection (cN2, pN2). METHODS: Retrospective analysis of the National Cancer Database of patients from 2004 to 2011 with cN0 and cN2 status found to be pathologic stage III-N2 NSCLC after surgical resection. Comparison of 5-year survival of patients with unsuspected N2 disease versus those with known N2 disease after surgical resection using Kaplan-Meier analysis was made. The independent effect of unsuspected N2 disease on mortality was analyzed using multivariate analysis. RESULTS: A total of 3271 patients with pathologic stage III-N2 NSCLC underwent curative intent surgical resection with or without adjuvant chemotherapy or chemotherapy and radiation. Unsuspected N2 disease was identified in 48% of patients. Patients with unsuspected N2 disease were more likely to have T1 tumors (37 vs. 32%, p < 0.001). Unsuspected N2 disease did not impact 5-year overall survival compared with known N2 when adjuvant therapy was utilized (40 vs. 37%, p = 0.167). Multivariate analysis identified older age, higher comorbidity score, and treatment with surgery alone as independent risk factors for mortality. The presence of unsuspected N2 disease was not significant in this model. CONCLUSIONS: The findings of this study suggest that unsuspected N2 disease is associated with equivalent 5-year survival compared to cN2 disease when adjuvant therapy is employed. These results support the use of adjuvant chemotherapy and radiation therapy when confronted with unsuspected N2 disease after surgical resection for stage IIIA-NSCLC.

Historical biogeography and ecological niche modelling of the Asimina-Disepalum clade (Annonaceae): role of ecological differentiation in Neotropical-Asian disjunctions and diversification in Asia.

BACKGROUND: The Asimina-Disepalum clade (Annonaceae subfam. Annonoideae tribe Annoneae) includes a major Neotropical-Asian biogeographical disjunction. We evaluate whether this disjunction can be explained by the Eocene boreotropics hypothesis, which relies on the existence of extensive boreotropical forests during the Late Palaeocene-Early Eocene thermal maximum (52-50 Ma), followed by disruption of boreotropical vegetation during post-Eocene cooling. Molecular dating using an uncorrelated relaxed molecular clock (UCLD) model with two fossil calibrations, ancestral range estimation, and ecological niche modelling across evolutionary time were performed. Our focus was the geographical origin of Disepalum and general biogeographic patterns within this genus. Comparison of ecological tolerance among extant species and niche reconstructions at ancestral nodes within the clade enabled insights in likely migration routes of lineages, as well as evaluating the role of bioclimatic ecological differentiation in the diversification of Disepalum within Southeast Asia. RESULTS: The inferred vicariance event associated with the Asimina-Disepalum disjunction is estimated to have originated ca. 40 Mya [95% highest posterior density (HPD): 44.3-35.5 Mya]. The Disepalum crown lineage is estimated to have originated ca. 9 Mya (95% HPD: 10.6-7.6), either in western Malesia and continental Southeast Asia, or exclusively in western Malesia. Ecological niche modelling shows that seasonality of temperature and precipitation are major contributors determining the geographical range of species. Ancestral niche modelling furthermore indicates that the ancestor of the Asimina-Disepalum clade likely had bioclimatic preferences close to conditions found in current tropical and subtropical climates across Asia, whereas the ancestors of the Asimina and Disepalum crown groups are projected onto the more subtropical and tropical regions, respectively. CONCLUSIONS: The vicariance event associated with the Neotropical-Asian disjunction within the Asimina-Disepalum clade likely coincided with climatic deterioration at the Eocene-Oligocene boundary. Although detrended component analyses (DCA) indicate that altitude and seasonality of temperature and precipitation have the greatest influence in determining the geographical range of species, isolation due to palaeogeographic and palaeoclimatic events appears to be of greater significance than climate niche differentiation in driving diversification in Disepalum.

Molecular phylogenetics of the species-rich angiosperm genus Goniothalamus (Annonaceae) inferred from nine chloroplast DNA regions: Synapomorphies and putative correlated evolutionary changes in fruit and seed morphology.

A phylogenetic study of the genus Goniothalamus (Annonaceae) is presented using maximum parsimony, maximum likelihood and Bayesian approaches, with 65 species sampled (48.5% of the genus) based on sequences of nine chloroplast DNA regions (11,214 aligned positions). The resultant phylogeny clearly indicates that Goniothalamus is monophyletic. Preliminary research initially focused on identifying synapomorphies and estimating the phylogenetic signal of selected morphological characters based on parsimony and likelihood ancestral character state reconstructions. This prescreening of characters enabled 40 to be selected for further study, and of these 15 are shown here to demonstrate significant phylogenetic signal and to provide clear synapomorphies for several infrageneric clades. Although floral structure in Goniothalamus is comparatively uniform, suggesting a common basic pattern of pollination ecology, fruit and seed morphology in the genus is very diverse and is presumably associated with different patterns of frugivory. The present study assesses correlations amongst fruit and seed characters which are putatively of functional importance with regard to frugivory and dispersal. One-way phylogenetic ANOVA indicates significant phylogenetically independent correlation between the following fruit and seed characters: fruits borne on older branches and/or on the main trunk have larger monocarps than fruits borne on young branches; and monocarps that contain seeds with a hairy testa are larger than those with glabrous seeds. We discuss fruit morphologies and potential explanations for the inferred correlations, and suggest that they may be the result of adaptation to different frugivores (birds, larger non-volant animal and primate seed dispersers, respectively).

A plastid DNA phylogeny of tribe Miliuseae: insights into relationships and character evolution in one of the most recalcitrant major clades of Annonaceae.

PREMISE OF THE STUDY: Tribe Miliuseae (∼25 genera and ∼510 species) includes a substantial part of the species and generic diversity in the pantropical flowering-plant family Annonaceae (∼108 genera and ∼2400 species). Previous molecular phylogenetic analyses have failed to resolve the backbone phylogeny of the tribe, impeding biogeographical and evolutionary studies. We use a dense generic taxon sample (∼89% of generic diversity in Miliuseae) and plastid DNA sequence data (∼7 kb) to clarify the phylogenetic relationships of and within the tribe. METHODS: Parsimony and Bayesian phylogenetic reconstructions and ancestral character-state reconstructions of several reproductive characters were performed. KEY RESULTS: Dendrokingstoniae, Monocarpieae, and Miliuseae are recovered in a strongly supported clade, and each tribe is strongly supported as monophyletic. Miliuseae are characterized by a synapomorphic cryptoaperturate/disulculate pollen apertural system. Stenanona is shown to be nested within the paraphyletic genus Desmopsis. The only Neotropical clade (Sapranthus, Tridimeris, Desmopsis, and Stenanona) in the predominantly Asian Miliuseae is shown to be closely related to an undescribed genus from continental Southeast Asia and the Indo-Malayan and Austral-Pacific genus Meiogyne. Ancestral character-state reconstructions of several reproductive characters that are diagnostically important at the generic level indicate a considerable degree of homoplasy. CONCLUSIONS: The results improve our understanding of the relationships of and within Miliuseae, but parts of the backbone of the phylogeny remain poorly supported. Additional data from variable nuclear markers or reduced-genome-representation approaches seem to be required to further resolve relationships within this recalcitrant clade.

Conservation status assessments of species-rich tropical taxa in the face of data availability limitations: insights from Sulawesi Begonia.

Species conservation assessments using the criteria outlined by the International Union for the Conservation of Nature Red List can be compromised by limited data availability. Species-rich tropical plant taxa with numerous microendemics are particularly problematic. This study focusses on the Begonia flora of the Indonesian island of Sulawesi, comprised of 65 herbaceous species mainly found in rainforest habitats. Sixty-two species are Sulawesi endemics, including 20 species restricted to limestone karst landscapes. Forty-eight species are represented by fewer than 10 herbarium collections. Here, we outline and discuss an approach that, despite these data limitations, allows meaningful conservation assessments by integrating analyses of occurrences, data primarily based on remote sensing approaches, including forest landscape integrity, forest cover loss, and land cover, and extent of suitable habitat estimation. The results indicate that most Sulawesi Begonia species are narrow endemics whose rainforest habitats have substantially deteriorated in the last two decades: 27 species are assessed as Critically Endangered, 24 as Endangered, six as Vulnerable, five as Least Concern, and three species are Data Deficient. Conservation action, including extension of the protected area network in Sulawesi with emphasis on areas of old-growth forest and limestone karst landscapes, and strengthening of ex-situ living collections, is recommended.

The effects of serum calcium and parathyroid hormone changes on psychological and cognitive function in patients undergoing parathyroidectomy for primary hyperparathyroidism.

OBJECTIVE: This study had 2 aims: (1) to assess the timing and magnitude of psychological and neurocognitive changes before and after parathyroidectomy and (2) to examine correlations between changes in serum biomarkers and psychological symptoms and neurocognitive performance. BACKGROUND: Psychological and neurocognitive changes are common in patients with primary hyperparathyroidism (pHPT), but the associations of serum biomarkers and these changes have not been established. METHODS: This prospective cohort study carried out at a large tertiary care referral center from 2004 to 2008 screened all adult patients with the biochemical diagnosis of pHPT who underwent first-time parathyroidectomy. Laboratory results, psychological symptom reports, and results of neurocognitive testing using validated instruments were obtained preoperatively and at 1, 3, and 6 months postoperatively. Outcomes measures included serum calcium, intact parathyroid hormone (iPTH), and thyroid stimulating hormone; psychological symptom inventories (Beck Depression Inventory-II, Brief Symptom Inventory-18, and Spielberger State-Trait Anxiety Inventory); and neurocognitive test scores (Rey Auditory Verbal Learning Test and Groton Maze Learning Test). RESULTS: Two hundred twelve patients were enrolled; mean age was 60 years; 78% were female and had low comorbidity; 78% had parathyroidectomy under ambulatory, minimally invasive techniques; cure rate was 99%. Improvements in psychological and neurocognitive measures were observed at all postoperative follow-up visits. The most pronounced improvements were noted in depressive and anxiety symptoms, and visuospatial and verbal memory. Examination of change scores revealed that postoperative reduction in iPTH was associated with a decrease in state anxiety, which was also associated with improvement in visuospatial working memory. CONCLUSIONS: Reduction in mood and anxiety symptoms is associated with reductions in both iPTH and spatial working memory in patients with pHPT who undergo successful parathyroidectomy.

Parathyroidectomy in the elderly: analysis of 7313 patients.

BACKGROUND: The elderly are the fastest growing subset of the U.S. population, and suffer most from primary hyperparathyroidism. This is the first multi-institutional study to characterize 30-d outcomes in elderly patients undergoing parathyroidectomy. MATERIALS AND METHODS: Patients who underwent parathyroidectomy for primary hyperparathyroidism in ACS-NSQIP, 2005-8, were stratified into age groups: 45-64, 65-79, and ≥80 y. Independent patient variables included gender, race, inpatient/outpatient type, anesthesia, ASA classification, functional status, and presence/absence of >30 conditions. Outcomes included overall/system-specific complications, return to the OR, operating times, LOS, 30-d mortality. Patients 65-79 and ≥80 y were compared with younger ones using multivariable linear and logistic regression. RESULTS: A total of 7313 patients were identified: 77.8% women, 77.2% White, and 95.6% underwent first-time parathyroidectomy. Patients 65-79 and ≥ 80 y were more likely to have inpatient parathyroidectomies compared with younger patients (42.4%, 46.8% versus 36.0%) and higher ASA classification (42.4%, 59.8% versus 24.2%, all P < 0.01). Patients ≥ 80 y were less likely than those 45-64 y to receive general anesthesia (84.9% versus 89.8%, P < 0.01). Patients ≥ 65 y were more likely to have ≥1 complication (2.2% versus 1.3%, P < 0.01) and respiratory-specific complications compared with younger patients (0.9% versus 0.3%, P < 0.01). Patients 65-79 and ≥80 y were more likely to have extended hospital stays (7.7%, 12.2% versus 6.5%, P < 0.01); mortality rate for patients ≥ 80 y was higher (0.8% versus <0.1%, P < 0.01). On multivariable analysis, patients ≥ 65 y had increased risks for overall/respiratory complications and extended hospital stays, (all P < 0.01). CONCLUSIONS: Elderly patients sustain more morbidity following parathyroidectomy. Advanced age may be an independent risk factor worth considering in surgical decision-making.

Mycena citrinomarginata is associated with roots of the perennial grass Festuca roemeri in Pacific Northwest prairies.

Prairies in the Pacific Northwest are dominated by perennial bunchgrasses. A Mycena in the citrinomarginata complex was observed to tightly co-occur with bunchgrasses at several prairie study sites. Mapping and spatial statistics showed that it was strongly and significantly associated with Festuca roemeri tussocks. We further found that this fungus is attached to F. roemeri roots (17/17 examined) and both specific primers and next-generation DNA sequencing established that the fungus is in the roots, suggesting that M. citrinomarginata may be endophytic or biotrophic in some contexts, and not simply saprotrophic. These results combined with a literature review indicate that Mycena species are often found as endophytes in grass roots. Given the importance of grasses and grasslands for humans, this ecological association deserves further study.

Phylogenomics resolves deep subfamilial relationships in Malvaceae s.l.

Malvaceae s.l., the most diverse family within Malvales, includes well-known species of great economic importance like cotton, cacao, and durian. Despite numerous phylogenetic analyses employing multiple markers, relationships between several of its nine subfamilies, particularly within the largest lineage /Malvadendrina, remain unclear. In this study, we attempted to resolve the relationships within the major clades of Malvaceae s.l. using plastid genomes of 48 accessions representing all subfamilies. Maximum likelihood and Bayesian analyses recovered a fully resolved and well-supported topology confirming the split of the family into /Byttneriina (/Grewioideae +/Byttnerioideae) and /Malvadendrina. Within /Malvadendrina, /Helicteroideae occupied the earliest branching position, followed by /Sterculioideae, /Brownlowioideae, /Tiliodeae, and /Dombeyoideae formed a clade sister to /Malvatheca (/Malvoideae +/Bombacoideae), a grouping morphologically supported by the lack of androgynophore. Results from dating analyses suggest that all subfamilies originated during hot or warm phases in the Late Cretaceous to Paleocene. This study presents a well-supported phylogenetic framework for Malvaceae s.l. that will aid downstream revisions and evolutionary studies of this economically important plant family.

Chromosome-level reference genome of the soursop (Annona muricata): A new resource for Magnoliid research and tropical pomology.

The flowering plant family Annonaceae includes important commercially grown tropical crops, but development of promising species is hindered by a lack of genomic resources to build breeding programs. Annonaceae are part of the magnoliids, an ancient lineage of angiosperms for which evolutionary relationships with other major clades remain unclear. To provide resources to breeders and evolutionary researchers, we report a chromosome-level genome assembly of the soursop (Annona muricata). We assembled the genome using 444.32 Gb of DNA sequences (676× sequencing depth) from PacBio and Illumina short-reads, in combination with 10× Genomics and Bionano data (v1). A total of 949 scaffolds were assembled to a final size of 656.77 Mb, with a scaffold N50 of 3.43 Mb (v1), and then further improved to seven pseudo-chromosomes using Hi-C sequencing data (v2; scaffold N50: 93.2 Mb, total size in chromosomes: 639.6 Mb). Heterozygosity was very low (0.06%), while repeat sequences accounted for 54.87% of the genome, and 23,375 protein-coding genes with an average of 4.79 exons per gene were annotated using de novo, RNA-seq and homology-based approaches. Reconstruction of the historical population size showed a slow continuous contraction, probably related to Cenozoic climate changes. The soursop is the first genome assembled in Annonaceae, supporting further studies of floral evolution in magnoliids, providing an essential resource for delineating relationships of ancient angiosperm lineages. Both genome-assisted improvement and conservation efforts will be strengthened by the availability of the soursop genome. As a community resource, this assembly will further strengthen the role of Annonaceae as model species for research on the ecology, evolution and domestication potential of tropical species in pomology and agroforestry.

Correlated evolution of diaspore traits and potential frugivore-mediated selection in a fleshy-fruited tropical lineage (Artabotrys, Annonaceae).

Dispersal syndromes are often defined by reference to fruit traits that are associated with distinct frugivore guilds. Studies rarely examine the relationship between seed traits and frugivores or test the alternative hypothesis that traits are shaped by climatic variables. We assess whether the evolution of seed size and physical defense are correlated with dispersal-related traits and climatic variables in Artabotrys, a fleshy-fruited tropical lineage. Diaspore traits and WorldClim bioclimatic variables were compiled for 43 species. Correlated evolution was evaluated using phylogenetic regression and model-fitting approaches. The best-fitting multioptima Ornstein-Uhlenbeck model suggests that lineages with smooth testa and thin pericarp (SP) have evolved toward smaller seeds with a thinner testa, whereas lineages with rough testa and/or thick pericarp have evolved toward larger seeds with a thicker testa. A smooth testa facilitates spitting and/or swallowing of intact seeds while fruits with thin pericarp may be preferentially consumed by frugivores with less destructive oral processing, enabling lower investment in seed physical defense in SP lineages. Moreover, small seeds are more likely to be swallowed intact with a food bolus. The effect of climate on seed size and physical defense is equivocal and warrants further investigation.

Evaluating the surgery literature: can standardizing peer-review today predict manuscript impact tomorrow?

OBJECTIVE: Evidence-based surgery is predicated on the quality of published literature. We measured the quality of surgery manuscripts selected by peer review and identified predictors of excellence. METHODS: One hundred twenty clinical surgery manuscripts were randomly selected from 1998 in 5 eminent peer-reviewed surgery and medical journals. Manuscripts were blinded for author, institution, and journal of origin. Four surgeons and 4 methodologists evaluated the quality using novel instruments based on subject selection, study protocol, statistical analysis/inference, intervention description, outcome assessments, and results presentation. Predictors of quality and impact factor were identified using bivariate and multivariate regression. RESULTS: Oncology was the most common subject (26%), followed by general surgery/gastrointestinal (24%). The average number of study subjects was 417; the majority of manuscripts were American (53%), from a single institution (59%). Eighteen percent had a statistician author. Mean number of citations was 128. Surgery manuscripts from medical, compared with surgery journals, had better total quality scores (3.8 vs. 5.2, P < 0.001). They had more subjects and were more likely to have a statistician as coauthor (43% vs. 10%, P < 0.001), multi-institutional, international collaboration (30% vs. 8%, P < 0.001), and higher citation index (mean: 350 vs. 54, P < 0.001). They were more often foreign (70% vs. 40%, P < 0.001). Independent predictors of quality were having a statistician coauthor, study funding, European origin, and more study subjects. Quality assessment using our instruments predicted the number of citations after 10 years (P < 0.01), along with having a statistician coauthor, international multi-institutional collaboration, and more subjects. CONCLUSION: The quality of surgery manuscripts can be improved by including a statistician as coauthor, with efforts directed toward implementing multi-institutional/interdisciplinary trials. Peer-review across journals can be standardized through the use of instruments measuring methodologic and clinical quality.

Defining the learning curve in robot-assisted thoracoscopic lobectomy.

BACKGROUND: Robot-assisted thoracoscopic lobectomy has been shown to be a safe approach to pulmonary lobectomy. This study sought to define, mathematically, the learning curve for RATS lobectomy. METHODS: Patients undergoing robot-assisted thoracoscopic lobectomy at a single institution from 2010 through 2016 were considered. Covariates included patient demographics, comorbidities, operating time, length of stay, estimated blood loss, and postoperative complications. A cumulative sum analysis of operating time was performed to define the learning curve. RESULTS: A total of 101 patients were included. Three distinct phases of the learning curve were identified: cases 1-22, cases 23-63, and cases 64-101. There was a statistically significant difference in operating time and estimated blood loss between phases 1 and 2 (P < .05, P = .016, respectively) and between phases 1 and 3 (P < .05, P = .006, respectively). There was no statistically significant difference in comorbidities, chest tube duration, length of stay, postoperative complications, or conversion rate across the learning curve. CONCLUSION: Based on operating time, the learning curve for robot-assisted thoracoscopic lobectomy is 22 cases, with mastery achieved after 63 cases. No differences in length of stay, chest tube duration, conversion rate, or complication rate were observed in the learning curve. Other factors not measured in this study may play a role in the learning process and warrant further study.

Clinical and economic outcomes of thyroid and parathyroid surgery in children.

CONTEXT: Clinical and economic outcomes after thyroidectomy/parathyroidectomy in adults have demonstrated disparities based on patient age and race/ethnicity; there is a paucity of literature on pediatric endocrine outcomes. OBJECTIVE: The objective was to examine the clinical and demographic predictors of outcomes after pediatric thyroidectomy/parathyroidectomy. DESIGN: This study is a cross-sectional analysis of Healthcare Cost and Utilization Project-National Inpatient Sample hospital discharge information from 1999-2005. All patients who underwent thyroidectomy/parathyroidectomy were included. Bivariate and multivariate analyses were performed to identify independent predictors of patient outcomes. SUBJECTS: Subjects included 1199 patients 17 yr old or younger undergoing thyroidectomy/parathyroidectomy. MAIN OUTCOME MEASURES: Outcome measures included in-hospital patient complications, length of stay (LOS), and inpatient hospital costs. RESULTS: The majority of patients were female (76%), aged 13-17 yr (71%), and White (69%). Whites were more often in the highest income group (80% vs. 8% for Hispanic and 6% for Black; P < 0.01) and had private/HMO insurance (76% vs. 10% for Hispanic and 5% for Black; P < 0.001) rather than Medicaid (13% vs. 32% for Hispanic and 41% for Black; P < 0.001). Ninety-one percent of procedures were thyroidectomies and 9% parathyroidectomies. Children aged 0-6 yr had higher complication rates (22% vs. 15% for 7-12 yr and 11% for 13-17 yr; P < 0.01), LOS (3.3 d vs. 2.3 for 7-12 yr and 1.8 for 13-17 yr; P < 0.01), and higher costs. Compared with children from higher-income families, those from lower-income families had higher complication rates (11.5 vs. 7.7%; P < 0.05), longer LOS (2.7 vs. 1.7 d; P < 0.01), and higher costs. Children had higher endocrine-specific complication rates than adults after parathyroidectomy (15.2 vs. 6.2%; P < 0.01) and thyroidectomy (9.1 vs. 6.3%; P < 0.01). CONCLUSIONS: Children undergoing thyroidectomy/parathyroidectomy have higher complication rates than adult patients. Outcomes were optimized when surgeries were performed by high-volume surgeons. There appears to be disparity in access to high-volume surgeons for children from low-income families, Blacks, and Hispanics.

Organ Homologies and Perianth Evolution in the Dasymaschalon Alliance (Annonaceae): Inner Petal Loss and Its Functional Consequences.

The Dasymaschalon alliance within the early divergent angiosperm family Annonaceae comprises c. 180 species in four genera (Dasymaschalon, Desmos, Friesodielsia, and Monanthotaxis). The alliance offers an excellent opportunity for investigating perianth evolution and functional adaptations because of the presence of different numbers of petal whorls and contrasting floral chamber morphologies. The absence of the inner petal whorl in Dasymaschalon renders it distinctive in the family: previous studies have suggested that its three outermost stamens might be homologous with the inner petals of the sister genus, Friesodielsia, reflecting a homeotic shift of floral organ identify from inner petals to stamens. To investigate this hypothesis and general perianth evolution in the alliance, we (i) compared the floral vascularization of selected Dasymaschalon and Friesodielsia species using paraffin serial sectioning, and (ii) mapped selected perianth characters of inferred functional significance onto a molecular phylogenetic framework of the Dasymaschalon alliance (46 accessions; five cpDNA, and two nrDNA markers). The results indicate that the vasculature of the outermost stamen whorl of Dasymaschalon does not fuse with the perianth cortical vascular system, but instead splits from the basal traces of the free stamen bundles, contradicting previous inferences of homology with the inner corolla whorl of other Annonaceae. The loss of the inner petal whorl in Dasymaschalon is less likely to be due to a homeotic mutation, and instead possibly involved either the loss of genes that are responsible for determining inner petals or else the expression failure of these genes. Optimizations of perianth characters indicate that the absence of the inner petal whorl and the connivence of outer petals during anthesis are synapomorphic for Dasymaschalon. Circadian trapping of pollinators is inferred either to be derived in the stem lineage of the Dasymaschalon-Friesodielsia clade, or else to have evolved in parallel in the Dasymaschalon and Friesodielsia lineages. Subsequent changes in the remaining petals of Dasymaschalon flowers (which do not fully separate during anthesis) are likely to have enabled perpetuation of the circadian trapping mechanism, lessening the adverse impacts of inner petal loss.