Abstract. Ecologists and evolutionary biologists perceive the ecological niche as a multidimensional relationship between an organism and its environment. Yet, we know little about the degree to which multiple niche axes evolve in concert across various spatial scales to explain differences in distribution patterns and habitat specialization among lineages. Here we used contemporary phylogenetic approaches to analyze the evolution of species' distributions across multiple spatial scales in Lasthenia, a young and ecologically diverse plant clade largely occurring within the California Floristic Province, USA. Lasthenia species and subspecies range from widely distributed taxa that occupy a diversity of habitat types to locally restricted habitat endemics, including several lineages that are strongly associated with isolated ephemeral wetlands called vernal pools. We quantified the niche of Lasthenia species and subspecies at three different spatial scales: the range-wide climate niche, the habitat niche, and the within-habitat depth niche for those taxa occupying vernal pools. We incorporated phylogenetic uncertainty into our analyses by reanalyzing previously described DNA sequences in a Bayesian context and conducting all subsequent comparative analyses over the resulting posterior distribution of ultrametric phylogenetic trees. Using a biogeographic approach for ancestral habitat reconstruction, we estimated that Lasthenia lineages have undergone up to four independent transitions from strictly terrestrial habitats to a niche that incorporates semiaquatic habitats, and one of these transitions led to the subsequent proliferation of vernal pool species and subspecies. We found that the local niche axis, corresponding to the depth distribution of taxa within pools, was more phylogenetically conserved than the large-scale axes representing climatic associations. Furthermore, we did not find evidence that niche breadth estimates along different axes were consistently correlated, indicating that ecological specialization may be specific to certain niche axes rather than an overall characteristic of a species.

Introduction A significant proportion of patients undergoing endovascular aneurysm repair (EVAR) have common iliac artery aneurysms (CIAA). Aneurysmal involvement at the iliac bifurcation potentially undermines long-term durability. Methods Patients who underwent EVAR with CIAA were identified in two teaching hospitals. Bell-bottom technique (iliac limb ≥ 20mm) (BBT) or internal iliac artery embolization and limb extension to the external iliac artery (IIE+EE) were used. Outcome between these two approaches are compared. Results One hundred and eighty five patients were identified. . Indication for EVAR included asymptomatic AAA (n=157), symptomatic or ruptured aneurysm (n=19), and common iliac artery aneurysm (n=9). Mean AAA diameter was 59 mm. A total of 260 large CIAAs were treated. One hundred and sixty six CIAA limbs were treated with BBT, 94 limbs underwent IIE+EE. Total reintervention rates were similar for BBT (n=19, 11%) and IIE+EE (n=18, 19.1%) (p=0.149). Similar rates of reintervention for type 1b or 3 endoleak are reported, BBT (n=7, 4%) versus IIE+EE (n=4, 4%) (p=1.0). There was no significant difference in limb patency rates. Thirty-day mortality was 1%. Median follow-up was 22 months. While there was no significant difference in complications between the two groups the combined incidence of perioperative complications and reinterventions was higher in the IIE+EE group (49% versus 22%, p-0.002). Conclusion The combined incidence of perioperative complications and reinterventions is significantly higher in the IIE+EE when compared with the BB technique. Therefore, when feasible, BB is desirable..

Background Carotid artery stenting (CAS) has grown as a possible alternative for the treatment of extracranial cerebrovascular disease in the past decade. A pre-existing contralateral carotid artery occlusion has been described as a risk factor for inferior outcomes following carotid endarterectomy (CEA), yet its impact on CAS outcomes is less understood. Methods Retrospective review of 417 CAS procedures from May 2001 through July 2010 at a single center using self-expanding nitinol stents and mechanical embolic protection devices. Patients were divided into those with a pre-existing contralateral carotid occlusion (Group A, n=39) versus those without a contralateral occlusion (Group B, n=378). Patient demographics and co-morbidities as well as 30-day and late death, stroke, and myocardial infarction (MI) rates were analyzed. Mean follow-up was 4.0 years (range 0–9.4 years). Results Overall mean age of the 314 men and 103 women was 70.5 years. In Group A there were 2 (5.1%) octogenarians and 9 patients (23.1%) with symptomatic disease as compared to Group B with 53 (14.0%) octogenarians and 121 (32.0%) patients with symptomatic disease. The overall 30-day death, stroke, and MI rates were 0.5%, 1.9%, and 0.7%. When comparing Group A to Group B these results were not significantly different: death (0% vs 0.5%), stroke (2.6% vs 1.9%), and MI (0% vs 0.8%). Long-term outcomes for Groups A and B were not significantly different: death (25.6% vs 22.2%), stroke (5.3% vs 3.4%), and MI (15.4% vs 14.0%) (p=NS). Conclusion A pre-existing contralateral carotid artery occlusion does not appear to adversely impact CAS outcomes.

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