Consensus is growing among ecologists that energy and the factors influencing its utilization can play overarching roles in regulating large-scale patterns of biodiversity. The deep sea—the world's largest ecosystem—has simplified energetic inputs and thus provides an excellent opportunity to study how these processes structure spatial diversity patterns. Two factors influencing energy availability and use are chemical (productive) and thermal energy, here represented as seafloor particulate organic carbon (POC) flux and temperature. We related regional patterns of benthic molluscan diversity in the North Atlantic to these factors, to conduct an explicit test of species–energy relationships in the modern day fauna of the deep ocean. Spatial regression analyses in a model-averaging framework indicated that POC flux had a substantially higher relative importance than temperature for both gastropods and protobranch bivalves, although high correlations between variables prevented definitive interpretation. This contrasts with recent research on temporal variation in fossil diversity from deep-sea cores, where temperature is generally a more significant predictor. These differences may reflect the scales of time and space at which productivity and temperature operate, or differences in body size; but both lines of evidence implicate processes influencing energy utilization as major determinants of deep-sea species diversity.
species–energy; productivity; temperature; mollusc; diversity
Lithodid crabs (and other skeleton-crushing predators) may have been excluded from cold Antarctic continental shelf waters for more than 14 Myr. The west Antarctic Peninsula shelf is warming rapidly and has been hypothesized to be soon invaded by lithodids. A remotely operated vehicle survey in Palmer Deep, a basin 120 km onto the Antarctic shelf, revealed a large, reproductive population of lithodids, providing the first evidence that king crabs have crossed the Antarctic shelf. DNA sequencing and morphology indicate the lithodid is Neolithodes yaldwyni Ahyong & Dawson, previously reported only from Ross Sea waters. We estimate a N. yaldwyni population density of 10 600 km−2 and a population size of 1.55 × 106 in Palmer Deep, a density similar to lithodid populations of commercial interest around Alaska and South Georgia. The lithodid occurred at depths of more than 850 m and temperatures of more than 1.4°C in Palmer Deep, and was not found in extensive surveys of the colder shelf at depths of 430–725 m. Where N. yaldwyni occurred, crab traces were abundant, megafaunal diversity reduced and echinoderms absent, suggesting that the crabs have major ecological impacts. Antarctic Peninsula shelf waters are warming at approximately 0.01°C yr−1; if N. yaldwyni is currently limited by cold temperatures, it could spread up onto the shelf (400–600 m depths) within 1–2 decades. The Palmer Deep N. yaldwyni population provides an important model for the potential invasive impacts of crushing predators on vulnerable Antarctic shelf ecosystems.
lithodids; invasion; Antarctic; climate warming; bioturbation; biodiversity loss
Mitral valve annular calcification has long been a challenge in repairing posterior mitral valve prolapse. Folding valvuloplasty of the posterior leaflet without resection provides a means of circumventing common procedural complications. This report demonstrates the success of folding valvuloplasty without resection in the treatment of mitral valve prolapse and severe annular calcification.
Mitral valve repair; Valvuloplasty; Calcification mitral annulus
The aim of this study was to compare the cost and effectiveness of a minimally invasive (MI) versus traditional sternotomy (ST) approach for mitral valve surgery (MVS).
From 1/1/03–12/31/08, 847 patients underwent isolated MVS at our institution. Propensity matching on 22 clinical variables was carried out to generate a study cohort of 434 patients (217 matched pairs). Direct and indirect costs from the hospital perspective were retrospectively obtained from our finance department. Total hospital costs were further stratified into 13 standardized institutional billing categories. In addition, data on morbidity, mortality, discharge location, hospital readmissions within one year, and freedom from reoperation were obtained.
Compared to ST, MIMVS was associated with a $9,054 ± 3,302 lower mean total hospital cost (p=0.006), driven largely by a reduction in direct (p=0.003) versus indirect costs (p=0.06). Among the 13 billing categories, MIMVS was associated with a significant reduction in costs of: cardiac imaging (p=0.004), laboratory tests (p=0.005), boarding and nursing (p=0.001), and radiology (p=0.002). More patients in the ST group required intubation for > 72 hours (p=0.019); however, there were no differences in morbidity or long-term survival (p=0.334). There were a higher proportion of MI patients discharged home with no nursing services (p=0.018), and a higher proportion of readmissions among ST patients within one year (p=0.023). There were no differences in freedom from reoperation between groups (p=0.574).
With equivalent efficacy across a range of measures and lower costs compared to ST, MIMVS represents a cost-saving strategy for MVS.
There is little information on the relative survival of coronary artery bypass graft (CABG) surgery and percutaneous coronary intervention with stenting with follow-up longer than 5 years. This study tested the hypothesis that CABG surgery is associated with lower risk of long-term (8-year) mortality than stenting with bare-metal stents for multivessel coronary disease.
We identified 18,359 patients with multivessel disease who underwent isolated CABG surgery and 13,377 patients who received BMS in 1999–2000 in New York, and followed their vital status through 2007 using the National Death Index. We matched CABG and stent patients on the number of diseased coronary vessels, proximal left anterior descending (LAD) artery disease, and propensity of undergoing CABG surgery based on numerous patient characteristics, and compared the survival after the two procedures.
In the 7,235 pairs of matched patients, the overall 8-year survival rates were 78.0% for CABG surgery and 71.2% for stenting (hazard ratio = 0.68, 95% confidence interval: 0.64 to 0.74, P<0.001). For anatomic groups classified by the number of diseased vessels and proximal LAD involvement, the hazard ratios ranged from 0.53 (P<0.001) for patients with 3-vessel disease involving proximal LAD artery disease to 0.78 (P=0.05) for patients with 2-vessel disease but no disease in the LAD artery. A lower risk of death after CABG surgery was observed in all subgroups stratified by a number of baseline risk factors.
CABG surgery is associated with lower risk of death than stenting with bare-metal stents for multivessel coronary disease.
Coronary artery bypass grafts; Coronary percutaneous interventions; Outcomes
Sediments associated with hydrothermal venting, methane seepage and large organic falls such as whale, wood and plant detritus create deep-sea networks of soft-sediment habitats fueled, at least in part, by the oxidation of reduced chemicals. Biological studies at deep-sea vents, seeps and organic falls have looked at macrofaunal taxa, but there has yet to be a systematic comparison of the community-level attributes of sediment macrobenthos in various reducing ecosystems. Here we review key similarities and differences in the sediment-dwelling assemblages of each system with the goals of (1) generating a predictive framework for the exploration and study of newly identified reducing habitats, and (2) identifying taxa and communities that overlap across ecosystems. We show that deep-sea seep, vent and organic-fall sediments are highly heterogeneous. They sustain different geochemical and microbial processes that are reflected in a complex mosaic of habitats inhabited by a mixture of specialist (heterotrophic and symbiont-associated) and background fauna. Community-level comparisons reveal that vent, seep and organic-fall macrofauna are very distinct in terms of composition at the family level, although they share many dominant taxa among these highly sulphidic habitats. Stress gradients are good predictors of macrofaunal diversity at some sites, but habitat heterogeneity and facilitation often modify community structure. The biogeochemical differences across ecosystems and within habitats result in wide differences in organic utilization (i.e., food sources) and in the prevalence of chemosynthesis-derived nutrition. In the Pacific, vents, seeps and organic-falls exhibit distinct macrofaunal assemblages at broad-scales contributing to ß diversity. This has important implications for the conservation of reducing ecosystems, which face growing threats from human activities.
Over the past decade, minimally invasive cardiothoracic surgery (MICS) has grown in popularity. This growth has been driven, in part, by a desire to translate many of the observed benefits of minimal access surgery, such as decreased pain and reduced surgical trauma, to the cardiac surgical arena. Initial enthusiasm for MICS was tempered by concerns over reduced surgical exposure in highly complex operations and the potential for prolonged operative times and patient safety. With innovations in perfusion techniques, refinement of transthoracic echocardiography and the development of specialized surgical instruments and robotic technology, cardiac surgery was provided with the necessary tools to progress to less invasive approaches. However, much of the early literature on MICS focused on technical reports or small case series. The safety and feasibility of MICS have been demonstrated, yet questions remain regarding the relative efficacy of MICS over traditional sternotomy approaches. Recently, there has been a growth in the body of published literature on MICS long-term outcomes, with most reports suggesting that major cardiac operations that have traditionally been performed through a median sternotomy can be performed through a variety of minimally invasive approaches with equivalent safety and durability. In this article, we examine the technological advancements that have made MICS possible and provide an update on the major areas of cardiac surgery where MICS has demonstrated the most growth, with consideration of current and future directions.
minimally invasive cardiothoracic surgery; outcomes
Submarine canyons are dramatic and widespread topographic features crossing continental and island margins in all oceans. Canyons can be sites of enhanced organic-matter flux and deposition through entrainment of coastal detrital export, dense shelf-water cascade, channelling of resuspended particulate material and focusing of sediment deposition. Despite their unusual ecological characteristics and global distribution along oceanic continental margins, only scattered information is available about the influence of submarine canyons on deep-sea ecosystem structure and productivity. Here, we show that deep-sea canyons such as the Kaikoura Canyon on the eastern New Zealand margin (42°01′ S, 173°03′ E) can sustain enormous biomasses of infaunal megabenthic invertebrates over large areas. Our reported biomass values are 100-fold higher than those previously reported for deep-sea (non-chemosynthetic) habitats below 500 m in the ocean. We also present evidence from deep-sea-towed camera images that areas in the canyon that have the extraordinary benthic biomass also harbour high abundances of macrourid (rattail) fishes likely to be feeding on the macro- and megabenthos. Bottom-trawl catch data also indicate that the Kaikoura Canyon has dramatically higher abundances of benthic-feeding fishes than adjacent slopes. Our results demonstrate that the Kaikoura Canyon is one of the most productive habitats described so far in the deep sea. A new global inventory suggests there are at least 660 submarine canyons worldwide, approximately 100 of which could be biomass hotspots similar to the Kaikoura Canyon. The importance of such deep-sea canyons as potential hotspots of production and commercial fisheries yields merits substantial further study.
submarine canyons; benthic biomass hotspots; molpadiid holothurians; macrourid fishes; eastern New Zealand margin
Aryl bromides and iodides in the presence of catalytic amounts of a palladacycle derived from acetophenone oxime and 2 equivalents of potassium acetate react with ethylene under ambient pressure (15–30 psi) to give the corresponding vinylarenes. The reactions work with both electron-deficient and electron-rich aryl compounds and tolerate wide variety of common functional groups. Vinyl bromides lead to 1,3-dienes in moderate yields.
A three-step procedure for the synthesis of 2-arylpropionic acids (profens) from vinyl arenes in nearly enantiomerically pure form has been developed. Excellent yields (>97%), regioselectivities (>99%), and enantioselectivities (>97% ee) for the desired branched products were obtained in the asymmetric hydrovinylation reactions of vinyl arenes, and the products from these reactions were transformed into 2-arylpropionic acids via oxidative degradation. Subsequent Curtius or Schmidt rearrangements of these acids provided highly valued 1-arylethyl amines, including a prototypical primary amine with an α-chiral tertiary N-alkyl group, in very good yields.
Over the past decade, minimally invasive cardiac surgery (MICS) has emerged as an accepted approach for the management of cardiac disease that requires a surgical solution. We report the results of an 8-year, single-institution experience with MICS.
Between January 1, 2000 and December 31, 2007, a total of 910 patients underwent MICS. Major cases included aortic valve procedures (71, 7.8%), coronary artery bypass grafting (96, 10.5%), atrioseptal defect repair (103, 11.3%), and mitral valve procedures (507, 55.7%). Major outcomes of interest included the complication and mortality rates.
The mean age of the patients was 57 ± 15 years; the mean ejection fraction was 55% ± 11%; and the mean body mass index was 26.1 ± 4.9. Overall, 782 cases (85.9%) were performed through a mini-thoracotomy. Most of the cases were accomplished through central cannulation (765, 84.0%), and venous drainage was most commonly performed in a bicaval fashion (percutaneous superior vena cava and percutaneous inferior vena cava). The mean aortic cross-clamp and cardiopulmonary bypass (CPB) times were 58.1 ± 44.9 and 101.9 ± 66.8 min, respectively. Conversion to full sternotomy occurred in 10 patients, and the median length of stay in hospital was 6 days. The overall complication rate was 8.8%, and the 30-day mortality rate was 2.9%. In the multivariate logistic regression analysis, risk factors associated with in-hospital complications included age, CPB time, arterial cannulation location, conversion from off-CPB to on-CPB, hepatic insufficiency, and diabetes. In the multivariate hazards regression analysis, risk factors associated with mortality included postoperative stroke, renal failure, and sternal wound infection; CPB time; and previous surgery.
In our experience, minimally invasive approaches are effective and reproducible for a variety of cardiac operations, with acceptable operating time durations, morbidity, and mortality.
Fine tuning of the biaryl and amino moieties of Feringa’s phosphoramidite ligands yields structurally simpler, yet more efficient and selective, ligands for asymmetric hydrovinylation of vinylarenes and acylic 1,3-dienes. The enantioselectivities and yields observed in the formation of the 3-arylbutenes are among the highest for all asymmetric catalytic processes reported to date for the synthesis of intermediates for the widely used antiinflammatory 2-arylpropionic acids including naproxen, ibuprofen, fenoprofen, and flurbiprofen.
1-Alkylstyrenes undergo efficient hydrovinylation (addition of ethylene) in the presence of a Ni-catalyst prepared from [(allyl)NiBr]2, Na+ [BAr4]− (Ar = 3,5-bis-trifluromethylphenyl), and a phosphoramidite ligand giving products in excellent yields and enantioselectivities. In many cases phosphoramidites derived from achiral 2,2′-biphenol are almost as good as ligands derived from the more expensive enantiopure 2,2′-binaphthols. The hydrovinylation products, which carry two versatile latent functionalities, an aryl and a vinyl group, are potentially useful for the synthesis of several important natural products containing benzylic all-carbon quaternary centers.
alkenes; asymmetric catalysis; hydrovinylation; phosphoramidite ligands; nickel
Mono- and 2,2′-di-substituted terminal alkenes can be isomerized into the more stable internal Z- and E- alkenes by treating them with catalytic amounts of [(allyl)PdCl]2 or [(allyl)NiBr]2, a triarylphosphine and silver triflate at room temperature. The isomeric ratio (E:Z) depends on the alkenes, the (E)-isomer being the major one. The reaction is tolerant to a wide variety of functional groups including other reactive olefins. Unlike the more reactive Ir catalysts, monosubstituted alkenes give almost exclusively the 2-alkenes. Direct comparison to two of the best-known catalysts for this process, (Ir(PCy3)3]+ [BPh4]−, and Grubbs Generation II metathesis catalyst) is also reported.
1,3-Dienes derived from steroidal D-ring C17-ketones undergo Ni(II)-catalyzed hydrovinylation to give 1,2- or 1,4-addition of ethylene. Using finely tuned phosphoramidite ligands it is possible to synthesize either the C20 (R)- or the C20 (S)-derivatives without mutual contamination. The proportion of the 1,4-adduct, which is also formed stereoselectively, can be minimized by optimizing the reaction conditions. Since the two alkenes in the resultant dienes have differing steric demands for many potential reactions, and are ideally juxtaposed for further D-ring functionalization, these intermediates could be useful for the preparation of biologically important compounds such as vitamin D analogs and various antitumor steroidal glycosides.
We describe a new species of the remarkable whalebone-eating siboglinid worm genus, Osedax, from a whale carcass in the shallow north Atlantic, west of Sweden. Previously only recorded from deep-sea (1500–3000 m) whale-falls in the northeast Pacific, this is the first species of Osedax known from a shelf-depth whale-fall, and the first from the Atlantic Ocean. The new species, Osedax mucofloris sp. n., is abundant on the bones of an experimentally implanted Minke whale carcass (Balaenoptera acutorostrata) at 125 m depth in the shallow North Sea. O. mucofloris can be cultured on bones maintained in aquaria. The presence of O. mucofloris in the shallow North Sea and northeast Pacific suggests global distribution on whale-falls for the Osedax clade. Molecular evidence from mitochondrial cytochrome oxidase 1 (CO1) and 18S rRNA sequences suggests that O. mucofloris has high dispersal rates, and provides support for the idea of whale-falls acting as ‘stepping-stones’ for the global dispersal of siboglinid annelids over ecological and evolutionary time.
Annelida; Polychaeta; Siboglinidae; Pogonophora; CO1
The possibility for commercial mining of deep-sea manganese nodules is currently under exploration in the abyssal Clarion-Clipperton Fracture Zone. Nematodes have potential for biomonitoring of the impact of commercial activity but the natural biodiversity is unknown. We investigate the feasibility of nematodes as biomonitoring organisms and give information about their natural biodiversity.
The taxonomic composition (at family to genus level) of the nematode fauna in the abyssal Pacific is similar, but not identical to, the North Atlantic. Given the immature state of marine nematode taxonomy, it is not possible to comment on the commonality or otherwise of species between oceans. The between basin differences do not appear to be directly linked to current ecological factors. The abyssal Pacific region (including the Fracture Zone) could be divided into two biodiversity subregions that conform to variations in the linked factors of flux to the benthos and of sedimentary characteristics. Richer biodiversity is associated with areas of known phytodetritus input and higher organic-carbon flux. Despite high reported sample diversity, estimated regional diversity is less than 400 species.
The estimated regional diversity of the CCFZ is a tractable figure for biomonitoring of commercial activities in this region using marine nematodes, despite the immature taxonomy (i.e. most marine species have not been described) of the group. However, nematode ecology is in dire need of further study.
We have reviewed our data from 391 patients entered into three prospective, double-blind studies of aminoglycosides and evaluated 127 cases to determine whether aminoglycoside-induced auditory toxicity and nephrotoxicity are independent events. The cases selected for evaluation included all patients treated for greater than 3 days (mean, 7.7 days) who had serial creatinine determinations and were able to cooperate with serial bedside audiograms (250 to 8,000 Hz). Patients received either gentamicin, tobramycin, or amikacin. Drug dosage was altered to keep serum levels 1 h after administration between 5 and 10 μg/ml (gentamicin or tobramycin) or 20 and 40 μg/ml (amikacin). The investigators evaluating auditory toxicity and nephrotoxicity were blind to the aminoglycoside being administered. The incidence of auditory toxicity in the nephrotoxic group (18.2%) was not significantly different from that in the nonnephrotoxic group (15.2%) (P = 0.75; Fisher exact test). There was no statistical difference between the nephrotoxic and auditory toxic groups in patient age, total dose of aminoglycoside, initial creatinine level, duration of therapy, or concurrent use of furosemide or cephalothin. We conclude that aminoglycoside-induced auditory toxicity and nephrotoxicity are independent events when the drug is administered for approximately 7 days and when aminoglycoside levels are maintained within a predefined range.
We conducted a prospective, randomized, double-blind comparison of intravenous penicillin and cefamandole in the therapy of pneumococcal pneumonia. Patients received either 1 g of cefamandole or 600,000 U of aqueous penicillin G every 6 h. Of the 100 patients entered into the study, 96 had clinical and radiographic evidence of pneumonia. Microbial etiology was determined from the results of sputum and blood cultures and/or sputum Gram stains. Streptococcus pneumoniae was pathogenic in 49 patients, of whom 24 received cefamandole and 25 received penicillin. There was no statistically significant difference in the response or cure rate. Of the 100 patients, 93 were treated for 3 days or more and were evaluated for adverse effects and toxicity. There was no significant difference between cefamandole-treated and pencillin-treated patients in the incidence of colonization, superinfection, phlebitis, thrombocytosis, decrease in hematocrit, or elevated liver function tests. Eosinophilia occurred more frequently in patients treated with penicillin (20 of 42) than in those treated with cefamandole (11 of 42 (chi square, P < 0.05). Only one patient receiving cefamandole developed a positive direct Coombs test. No patient in either group developed meningitis. We conclude that, with the doses and route of administration employed in this study, cefamandole is as effective as penicillin in the therapy of pneumococcal pneumonia without an increased incidence of colonization, superinfection, or adverse effects.
High kidney concentrations of gentamicin or amikacin, measured by an enzymological assay, were found in 9 of 10 patients who died during therapy with these aminoglycosides. Renal cortical concentrations of gentamicin ranged from 140 to 540 μg/g of tissue, with medullary levels of 128 to 230 μg/g. Concentrations of amikacin ranged from 365 to 1,030 μg/g in the cortex and from 270 to 718 μg/g in the medulla. The only patient with low kidney concentrations was an infant who received a single dose of gentamicin. Tissue levels were high in patients with both normal and abnormal renal function. Our results indicate that gentamicin and amikacin are concentrated in renal cortical and medullary tissue.
The survival difference between off-pump and on-pump coronary artery bypass graft (CABG) surgery for follow-up longer than 5 years is not well understood. The objective of this study is to examine the difference in 7-year mortality after these two procedures.
Methods and Results
New York State’s Cardiac Surgery Reporting System was used to identify the 2,640 off-pump and 5,940 on-pump isolated CABG patients discharged from July through December, 2000. The National Death Index was used to ascertain patients’ vital statuses through 2007. A logistic regression model was fit to predict the probability of receiving an off-pump procedure using baseline patient characteristics. Off-pump and on-pump patients were matched with a 1:1 ratio based on the probability of receiving an off-pump procedure. Kaplan-Meier survival curves for the 2 procedures were compared using the propensity-matched data, and the hazard ratio for death for off-pump in comparison to on-pump procedures was obtained. In subgroup analyses, the significance of interactions between type of surgery and baseline risk factors was tested. In this study, 2,631 pairs of off-pump and on-pump patients were propensity matched. The 7-year Kaplan-Meier survival rates were 71.2% and 73.4% (P=0.07) for off-pump and on-pump surgery, respectively. The hazard ratio for death (off-pump vs. on-pump) was 1.10 (95% confidence interval: 0.99-1.21, P=0.07). No statistical significance was detected for the interaction terms between type of surgery and a number of different baseline risk factors.
The difference in long-term morality between on-pump and off-pump CABG surgery is not statistically significant.
CABG; coronary artery disease; follow-up studies; mortality; off-pump surgery
The deep sea, the largest ecosystem on Earth and one of the least studied, harbours high biodiversity and provides a wealth of resources. Although humans have used the oceans for millennia, technological developments now allow exploitation of fisheries resources, hydrocarbons and minerals below 2000 m depth. The remoteness of the deep seafloor has promoted the disposal of residues and litter. Ocean acidification and climate change now bring a new dimension of global effects. Thus the challenges facing the deep sea are large and accelerating, providing a new imperative for the science community, industry and national and international organizations to work together to develop successful exploitation management and conservation of the deep-sea ecosystem. This paper provides scientific expert judgement and a semi-quantitative analysis of past, present and future impacts of human-related activities on global deep-sea habitats within three categories: disposal, exploitation and climate change. The analysis is the result of a Census of Marine Life – SYNDEEP workshop (September 2008). A detailed review of known impacts and their effects is provided. The analysis shows how, in recent decades, the most significant anthropogenic activities that affect the deep sea have evolved from mainly disposal (past) to exploitation (present). We predict that from now and into the future, increases in atmospheric CO2 and facets and consequences of climate change will have the most impact on deep-sea habitats and their fauna. Synergies between different anthropogenic pressures and associated effects are discussed, indicating that most synergies are related to increased atmospheric CO2 and climate change effects. We identify deep-sea ecosystems we believe are at higher risk from human impacts in the near future: benthic communities on sedimentary upper slopes, cold-water corals, canyon benthic communities and seamount pelagic and benthic communities. We finalise this review with a short discussion on protection and management methods.