Consistent stoichiometric long-term relationships between nutrients and chlorophyll-a across shallow lakes.

Aquatic ecosystems are threatened by eutrophication from nutrient pollution. In lakes, eutrophication causes a plethora of deleterious effects, such as harmful algal blooms, fish kills and increased methane emissions. However, lake-specific responses to nutrient changes are highly variable, complicating eutrophication management.

Nitrate as a predictor of cyanobacteria biomass in eutrophic lakes in a climate change context.

We aimed to predict cyanobacteria biomass and nitrate (NO) concentrations in Lake Võrtsjärv, a large, shallow, and eutrophic lake in Estonia. We used a model chain based on the succession of a mechanistic (INCA-N) model and an empirical, generalized linear model. INCA-N model calibration and validation was performed with long term climate and catchment parameters.

Hurricane Disturbance Stimulated Nitrification and Altered Ammonia Oxidizer Community Structure in Lake Okeechobee and St. Lucie Estuary (Florida).

Nitrification is an important biological link between oxidized and reduced forms of nitrogen (N). The efficiency of nitrification plays a key role in mitigating excess N in eutrophic systems, including those with cyanobacterial harmful algal blooms (cyanoHABs), since it can be closely coupled with denitrification and removal of excess N. Recent work suggests that competition for ammonium (NH ) between ammonia oxidizers and cyanoHABs can help determine microbial community structure.

External Sources Inhibit Benthic Phosphorus Fluxes in the Lower Great Miami River, Southwest Ohio.

Human activities have increased nutrient loadings to aquatic ecosystems, especially during the past century. During low river flow in late summer and early fall, elevated concentrations of phosphorus (P) and nitrogen are present in the temperate Lower Great Miami River and contribute to its eutrophication. Although wastewater treatment plants are suspected of being major sources of P to the river, riverbed sediment has not been examined as an additional potential source of P.

Reduced forms of nitrogen are a driver of non-nitrogen-fixing harmful cyanobacterial blooms and toxicity in Lake Erie.

Western Lake Erie (WLE) experiences anthropogenic eutrophication and annual, toxic cyanobacterial blooms of non-nitrogen (N) fixing Microcystis. Numerous studies have shown that bloom biomass is correlated with an increased proportion of soluble reactive phosphorus loading from the Maumee River. Long term monitoring shows that the proportion of the annual Maumee River N load of non-nitrate N, or total Kjeldahl nitrogen (TKN), has also increased significantly (Spearman's ρ = 0.

Ammonium recycling supports toxic Planktothrix blooms in Sandusky Bay, Lake Erie: Evidence from stable isotope and metatranscriptome data.

Sandusky Bay, Lake Erie, receives high nutrient loadings (nitrogen and phosphorus) from the Sandusky River, which drains an agricultural watershed. Eutrophication and cyanobacterial harmful algal blooms (cyanoHABs) persist throughout summer. Planktothrix agardhii is the dominant bloom-forming species and the main producer of microcystins in Sandusky Bay.

Community Biological Ammonium Demand: A Conceptual Model for Cyanobacteria Blooms in Eutrophic Lakes.

Cyanobacterial harmful algal blooms (CyanoHABs) are enhanced by anthropogenic pressures, including excessive nutrient (nitrogen, N, and phosphorus, P) inputs and a warming climate. Severe eutrophication in aquatic systems is often manifested as non-N-fixing CyanoHABs (e.g.

Mitigating cyanobacterial harmful algal blooms in aquatic ecosystems impacted by climate change and anthropogenic nutrients.

Mitigating the global expansion of cyanobacterial harmful blooms (CyanoHABs) is a major challenge facing researchers and resource managers. A variety of traditional (e.g.

It Takes Two to Tango: When and Where Dual Nutrient (N & P) Reductions Are Needed to Protect Lakes and Downstream Ecosystems.

Preventing harmful algal blooms (HABs) is needed to protect lakes and downstream ecosystems. Traditionally, reducing phosphorus (P) inputs was the prescribed solution for lakes, based on the assumption that P universally limits HAB formation. Reduction of P inputs has decreased HABs in many lakes, but was not successful in others.

Dynamic, mechanistic, molecular-level modelling of cyanobacteria: Anabaena and nitrogen interaction.

Phytoplankton (eutrophication, biogeochemical) models are important tools for ecosystem research and management, but they generally have not been updated to include modern biology. Here, we present a dynamic, mechanistic, molecular-level (i.e.

Controlling cyanobacterial blooms in hypertrophic Lake Taihu, China: will nitrogen reductions cause replacement of non-N2 fixing by N2 fixing taxa?

Excessive anthropogenic nitrogen (N) and phosphorus (P) inputs have caused an alarming increase in harmful cyanobacterial blooms, threatening sustainability of lakes and reservoirs worldwide. Hypertrophic Lake Taihu, China's third largest freshwater lake, typifies this predicament, with toxic blooms of the non-N2 fixing cyanobacteria Microcystis spp. dominating from spring through fall.

A shift in the archaeal nitrifier community in response to natural and anthropogenic disturbances in the northern Gulf of Mexico.

The Gulf of Mexico is affected by hurricanes and suffers seasonal hypoxia. The Deepwater Horizon oil spill impacted every trophic level in the coastal region. Despite their importance in bioremediation and biogeochemical cycles, it is difficult to predict the responses of microbial communities to physical and anthropogenic disturbances.

Endovascular treatment of the common femoral artery for limb ischemia.

Objective: To determine the short- and mid-term outcomes of percutaneous endovascular common femoral artery (CFA) revascularization (eCFR) of the CFA.

Methods: A review of patients who underwent eCFR for limb ischemia between 2006 and 2012 was performed. Limb salvage, patient survival, survival free from reintervention, and survival free from amputation rates were determined.

Isolated percutaneous transluminal angioplasty of the profunda femoris artery for limb ischemia.

Objective: To compare the outcome of endovascular profunda femoral artery revascularization (ePFR) with ePFR and concurrent endovascular femoropopliteal revascularization (eFPR).

Methods: A retrospective review of the consecutive patients with PFA and femoropopliteal vaso-occulsive disease who underwent ePFR or ePFR + eFPR for severe limb ischemia was performed.

Results: A total of 18 ePFRs and 26 ePFR + eFPRs were performed; 17 (94%) ePFRs and 22 (85%) ePFR + eFPRs were technically successful.

Periaortic inflammation after endovascular aneurysm repair.

Background: The periaortitis seen with inflammatory abdominal aortic aneurysms usually resolves after repair by both open and endovascular techniques. Conversely, the de novo development of retroperitoneal fibrosis after endovascular aneurysm repair (EVAR) has also been rarely described, and we present a case and also review the literature.

Methods And Results: A 63-year-old man underwent EVAR for an asymptomatic, noninflammatory abdominal aortic aneurysm, presenting 9 months subsequently with left loin pain, raised inflammatory markers, and radiological evidence of periaortic inflammation causing significant left ureteric obstruction.

Controlling harmful cyanobacterial blooms in a hyper-eutrophic lake (Lake Taihu, China): the need for a dual nutrient (N & P) management strategy.

Harmful cyanobacterial blooms, reflecting advanced eutrophication, are spreading globally and threaten the sustainability of freshwater ecosystems. Increasingly, non-nitrogen (N(2))-fixing cyanobacteria (e.g.

Percutaneous ultrasound-guided thrombin injection for the treatment of iatrogenic femoral artery pseudoaneurysms.

Purpose: To audit our experience with ultrasound-guided thrombin injection for the treatment of iatrogenic femoral artery pseudoaneurysms.

Methods: A retrospective study of 85 consecutive patients undergoing percutaneous ultrasound-guided thrombin injection of post-catheterization femoral pseudoaneurysms during the period January 2002 to May 2007.

Results: Pseudoaneurysms had a mean maximum diameter of 3.

The value of urgent carotid surgery for crescendo transient ischemic attacks.

Objective: This study audited operative risk in patients undergoing urgent carotid surgery for crescendo transient ischemic attacks (TIAs).

Methods: Interrogation of the vascular unit database (January 1992 to July 2004) identified 42 patients operated on urgently for crescendo TIAs, which were defined as>or=3 TIAs within the preceding 7 days. Stroke, death, and any major cardiac events were analyzed.

Carotid plaque instability and ischemic symptoms are linked to immaturity of microvessels within plaques.

Background: Instability and rupture of carotid atherosclerotic plaques leads to thromboemboli and ischemic symptoms. Angiogenesis occurs within atherosclerotic plaques, and plaque vulnerability and symptomatic carotid disease have been associated with increased numbers of microvessels. In addition to microvessel number, it is possible that the phenotypes of intraplaque vessels could influence plaque stability.

Endovascular abdominal aortic aneurysm repair in the presence of a kidney transplant: therapeutic considerations.

Abdominal aortic aneurysm (AAA) repair in the presence of a kidney transplant can be extremely challenging, as it carries significant risks of renal ischemia. Endovascular repair is an attractive option, as it can be performed with little or no impairment of renal arterial flow. We describe the endovascular management of a recurrent AAA in a patient with a functioning renal transplant using a custom-made aorto-uni-iliac device.