bluuebunny/crossref_metadata_2025 huggingface dataset:
Metastatic Bone Disease in Patients with Solid Tumors–-Burden of Bone Disease and the Role of Zoledronic Acid
Authors: Hirsh Vera
Published: November 2017

Bisphosphonates have become an integral component of the therapeutic repertoire for cancer patients at risk for skeletal-related events (SREs) such as pathologic fractures, bone pain requiring palliative radiotherapy, the need for orthopedic surgery, spinal cord compression, and hypercalcemia of malignancy because of bone metastases. Administered via monthly 15-minute infusion of up to 4 mg (depending on creatinine clearance rate), zoledronic acid (ZOL) has been approved for preventing SREs in patients with bone metastases from any solid tumor or bone lesions from multiple myeloma. Although there have been limited head-to-head comparison trials between bisphosphonates, ZOL displayed benefits beyond pamidronate in a large-scale comparative trial in patients with bone metastases from breast cancer. Monitoring of serum creatinine levels and oral health is important to ensure safety and comfort during treatment. In addition to the established benefits of bisphosphonates in the advanced cancer setting, there is a strong preclinical rationale and emerging clinical evidence that ZOL has antitumor activities and can delay metastasis in patients with early breast cancer. Studies are underway in patients with other tumor types, and the role of bisphosphonates is likely to evolve.
A Review of Sildenafil in the Treatment of Pediatric Pulmonary Arterial Hypertension
Authors: Krishnan Usha , Lovig Leif
Published: November 2017

This is a review article that discusses the role of sildenafil in pediatric pulmonary hypertension. The etiopathogenesis as well as prognosis for pediatric pulmonary hypertension (PH) differs from adults. The basic tenets of targeted management of PH however are similar. Sildenafil and other phosphodiesterase-5 inhibitors play a very important role in PH management, especially because of the ease of administration, low adverse effect profile, better tolerability and relative cost effectiveness. This is especially vital in situations where inhaled nitric oxide is not easily available and fills an important therapeutic gap. Large double blinded and controlled studies studying the effects of sildenafil in pediatric PH are not available. Equally vital would be long term efficacy studies, which should be initiated through large multicenter trials, to study the beneficial as well as long term side effects of this medication in the pediatric age group.
Management of Transfusional Chronic Iron Overload: Focus on Deferasirox
Authors: Pilo Federica , Di Tucci Anna Angela , Dessì Laura , Angelucci Emanuele
Published: November 2017

Most patients with hereditary or chronic acquired anemias are dependent on regular red cell transfusions. Untreated iron overload from transfusions is responsible for morbidity and mortality in patients with thalassemia major. However, clinical consequences of parenchymal iron overload have been reported not only in thalassemia major but also in patients with myelodysplastic syndrome. The current standard in iron chelation therapy is deferoxamine mesylate (Desferal®). Deferasirox is the first oral iron chelator approved in the Europe Union for use in patients with transfusional iron overload with different diseases. The aim of this review is to examine the properties and management of Deferasirox.
A Review of Raltegravir and its Use in HIV-1 Infection
Authors: Boesecke Christoph , Gelgor Linda
Published: November 2017

Raltegravir is the first antiretroviral drug in the class of integrase inhibitors approved for the treatment of human immunodeficiency virus type 1 (HIV-1) in combination with other antiretroviral agents in treatment-experienced adults with evidence of ongoing viral replication and resistance to multiple antiretroviral drugs. Since raltegravir has a different mechanism of action to the currently licensed antiretroviral agents, it is a welcome addition in the treatment of HIV-1. Results from clinical studies to date indicate that raltegravir exhibits potent antiviral activity particularly against HIV-1 strains which exhibit resistance to other classes of antiretroviral drugs. It is well tolerated and has a favorable safety profile. Long-term follow-up data on its resistance profile and on potential interactions with other antiretroviral as well as concomitant medications will ultimately define its future role in the treatment of HIV-1 infection. This review briefly describes the mechanism of action of raltegravir and its pharmacokinetic profile, summarizes efficacy and safety data from recent clinical trials and implications for the use in treatment-naïve as well as treatment-experienced patients, depicts raltegravir's emerging resistance profile, and highlights potential drug-drug interactions.
Safety and Efficacy of Panitumumab in the Treatment of Metastatic Colorectal Cancer
Authors: Freeman Daniel J.
Published: November 2017

Therapies targeting epidermal growth factor receptor (EGFR) are a promising recent development in the treatment of metastatic colorectal cancer (mCRC). Panitumumab is a fully human anti-EGFR monoclonal antibody that competitively inhibits the binding of all known EGFR ligands, including epidermal growth factor and transforming growth factor alpha, to cells expressing EGFR. In patients with mCRC, panitumumab monotherapy has resulted in favorable clinical responses, including increases in objective response rate, stable disease rate, and progression-free survival. Panitumumab has also shown promising antitumor activity in combination with selected chemotherapy regimens. Responses and improvements in progression-free survival associated with panitumumab monotherapy in patients with mCRC appear to be confined to patients whose tumors express wild-type KRAS. Therapy with panitumumab is generally well tolerated; the most common adverse events observed include skin-related toxicities, gastrointestinal toxicities, and hypomagnesemia. Infusion reactions are rare, and the agent has low immunogenicity.
Bevacizumab: Review of Development, Pharmacology, and Application to Brain Tumors
Authors: Newton Herbert B.
Published: November 2017

Bevacizumab is a humanised monoclonal antibody targeted to the vascular endothelial growth factor (VEGF). VEGF is the ligand for VEGF receptors (VEGFR), which are important for the development and maintenance of the angiogenic phenotype in high-grade solid tumors, including malignant gliomas. An overview of angiogenesis, VEGF, VEGFR, and the pharmacology of bevacizumab will be presented. Bevacizumab is active in pre-clinical testing against glioma tissue cultures and xenograft models. In the clinical setting, in combination with irinotecan and other chemotherapy agents, it has shown significant activity in patients with glioblastoma multiforme (GBM) and other brain tumors. Objective responses on neuro-imaging have been noted in 30%-60% of reported cases. Prolongation of progression-free survival and overall survival have also been suggested in many reports. Treatment of bevacizumab is associated with potential side effects, including thromboembolic disorders, fatigue, intracranial hemorrhage, proteinuria, hypertension, and bowel perforation.
Pharmacotherapy of Complicated Urinary Tract and Intra-abdominal Infections with Doripenem
Authors: Nicasio Anthony M. , Kuti Joseph L. , Nicolau David P.
Published: November 2017

Due to the growing rate of multi-drug resistant bacteria in complicated infections, the need for new broad-spectrum antimicrobials is paramount. Doripenem, a new addition to the intravenous carbapenem class, has recently been approved for the treatment of complicated lower urinary tract infections and/or pyelonephritis (cUTI) and complicated intra-abdominal infections (cIAI) in adult patients. Doripenem exhibits potent in vitro and in vivo bactericidal activity against an assortment of Gram-positive and Gram-negative aerobic and anaerobic organisms, including Pseudomonas aeruginosa, Acinetobacter baumannii, and Enterobacteriaceae that produce extended spectrum beta-lactamases (ESBL). Relative to other available carbapenems, doripenem typically displays MICs that are 1-2 dilutions lower than meropenem and 2-4 dilutions lower than imipenem against P. aeruginosa. Since the kidneys primarily excrete doripenem as whole drug, dose adjustments are needed in patients with renal impairment. Doripenem 500 mg q8 h demonstrated non-inferiority to levofloxacin 250 mg q24 h in clinical trials of patients with cUTI; it was non-inferior to meropenem 1000 mg q8 h in patients with cIAI. Doripenem's broad spectrum of activity, in vitro potency against particularly difficult to treat organisms, and desirable safety profile make it an attractive option in the treatment of cUTI and cIAI.
Safety and Efficacy of Cefazolin Sodium in the Management of Bacterial Infection and in Surgical Prophylaxis
Authors: Kusaba Tetsuro
Published: November 2017

Cefazolin sodium is a first-generation cephalosporin antibiotic and has been used worldwide since the early 1970s. It is used for the treatment of bacterial infections in various organs, such as the respiratory tract, skin and skin structure, genital tract, urinary tract, biliary tract, and bone and joint infections. It has also been used for septicemia due to susceptible gram-positive cocci (except Enterococcus), some gram-negative bacilli including E. coli, Proteus, and Klebsiella may be susceptible, and for perioperative prophylaxis. After the introduction of penicillins and other cephalosporins, occasional outbreaks of methicillin-resistant Staphylococcus aureus were noted. As a result, vancomycin use was increased; however, very recently and most alarmingly, vancomycin-resistant strains have been described. In this setting, to avoid the risk of the development of vancomycin-resistant strains further, vancomycin use should be curtailed. In consideration of this historical background, the appropriate use of antibiotics, such as dosage, dosage intervals, and the duration of administration is required not only for the protection of patients’ health but also for the prevention of the development of drug resistance. Cefazolin has been used in clinical practice for about 40 years, and a large body of evidence has been accumulated, and its efficacy and safety are well established compared with other antibiotics. Therefore, cefazolin has been chosen as a first-line anti-microbial for prophylaxis after various surgical procedures, including cardiovascular surgery, hysterectomy, arthroplasty and so on. Based on these facts, especially for the prophylaxis of surgical site infections, the first-generation cephalosporin, cefazolin, is now being “re-visited”.
Present and Prospective Pharmacotherapy for the Management of Patients with Type 2 Diabetes
Authors: Corsino Leonor , Cox Mary Elizabeth , Rowell Jennifer , Green Jennifer B.
Published: November 2017

Diabetes Mellitus is a chronic condition prevalent worldwide. Type 2 diabetes is the most common form of diabetes, comprising 90% to 95% of all cases. Over the last few decades, the importance of glycemic control and its impact on prevention of diabetes-related complications has been documented in multiple clinical trials. As most patients with type 2 diabetes will require pharmacologic intervention to achieve and maintain appropriate glycemic control, new medications targeting different aspects of the pathophysiology of type 2 diabetes have been a significant focus of research and development. During the last decade, multiple new medications for diabetes management have become available: these medications have novel mechanisms of action, differences in effectiveness, and varying side effect profiles which will be reviewed in this article. Some of these newer medications, such as the GLP-1 analogues and DPP-4 inhibitors, have become widely accepted as therapeutic options for the management of type 2 diabetes. Additional classes of glucose-lowering medications are expected to become available in the near future. This manuscript will summarize available data regarding these newer and prospective medications for the management of type 2 diabetes.
Therapeutic Options in Multiple Myeloma: Focus on Bortezomib
Authors: Roodman G. David
Published: November 2017

Myeloma is the most frequent malignancy to involve the bone. The bone microenvironment plays an important role in supporting tumor growth, bone destruction and resistance to chemotherapy. Until the advent of novel therapies such as bortezomib, the prognosis for patients with myeloma did not change significantly over 40 years. The median survival of patients until 1996 was approximately 30 months, and has now improved to almost 5 years. Bortezomib is the first-in-class proteasome antagonist approved for treatment of myeloma. It is active in newly diagnosed, relapsed and refractory patients and is now being used as a platform for combinations with other new agents for myeloma. Its major side effects include neuropathy and thrombocytopenia. In addition to its anti-myeloma effect, bortezomib also targets the bone microenvironment and can inhibit osteoclast formation, and stimulate osteoblast activity in patients with myeloma. Potentially, combination of bortezomib with other agents that stimulate bone formation or block bone resorption will further enhance the anti-myeloma effects of bortezomib and overcome the contribution of the tumor microenvironment to myeloma growth.
Management of EGFR-Mutant Non-Small Cell Lung Cancer: Focus on Gefitinib
Authors: Naito Yoichi , Goto Koichi
Published: November 2017

Gefitinib is a first generation, reversible epidermal growth factor receptor (EGFR) tyrosine kinase inhibitor (TKI), and EGFR TKIs, such as gefitinib and erlotinib, have yielded dramatic and durable responses in approximately 75% of of non-small cell lung cancer (NSCLC) patients whose tumor has an activating EGFR mutation. EGFR mutations are found in approximately 10%-15% of lung cancers in Caucasians, and they are more frequent in female patients, patients with adenocarcinoma, patients who are never-smokers or have a history of light-smoking, and patients with Asian ethnicity. Recent phase III trials comparing gefitinib with standard chemotherapy have demonstrated a similar survival benefit of gefitinib in patients with NSCLC and improved quality of life both in a first-line setting (IPASS; comparing gefitinib with carboplatin/paclitaxel) and a previously-treated setting (INTEREST; comparing gefitinib with docetaxel). Subset analyses of the data obtained in these studies showed that in patients with EGFR-mutant NSCLC gefitinib yielded a higher response rate, longer progression-free survival, and similar overall survival than standard cytotoxic chemotherapy did. The toxicity of EGFR TKIs is generally milder than that of standard cytotoxic chemotherapy. This review focuses on gefitinib, and issues in the management of EGFR-mutant NSCLC are discussed.
Lanreotide Autogel® in the Treatment of Acromegaly
Authors: Roelfsema Ferdinand , Biermasz Nienke R. , Pereira Alberto M. , Romijn Johannes A.
Published: November 2017

Background

In acromegaly expert surgery is curative in only about 60% of patients. Postoperative radiation therapy is associated with a high incidence of hypopituitarism and its effect on GH production is slow, so that adjuvant medical treatment becomes of importance in the management of many patients.

Objective

To delineate the role of lanreotide Autogel® in the treatment of acromegaly.

Methods

Search of Medline, Embase and Web of Science databases for clinical lanreotide studies in acromegaly.

Results

The weighted mean of serum GH normalization by Lanreotide Autogel®, based on 10 published clinical studies, was 58% in 370 patients. These patients were mostly switched from other somatostatin analogs. Serum IGF-I concentration normalized in 48% of these patients. Three small studies, with a total of 60 patients, compared the efficacy of octreotide LAR and that of lanreotide Autogel®. The highest dose of lanreotide appeared to be equivalent with 20 mg of octreotide LAR. Observed side effects were comparable with other somatostatin analogs, including octreotide LAR. Due to the lack of studies with previously, non-medically treated, patients no reliable data on tumor shrinkage is available.

Conclusion

Lanreotide Autogel®, a latecomer in the second generation of somatostatin analogs, has a therapeutic profile similarte octreotide LAR, which is now in clinical use for more than a decade. Preference for one of the drugs is dictated by the physician, patient and the cost of the drug.
Secondary Stroke Prevention, and the Role of Antiplatelet Therapies
Authors: Kirshner Howard S.
Published: November 2017

This review considers treatments of proved efficacy in secondary stroke prevention, with an emphasis on antiplatelet therapy. Most strokes could be prevented, if readily available lifestyle and risk factor modifications could be applied to everyone. In secondary stroke prevention, the same lifestyle and risk factor modifications are also important, along with anticoagulation for patients with cardiac sources of embolus, carotid procedures for patients with significant internal carotid artery stenosis, and antiplatelet therapy. For patients with noncardioembolic ischemic strokes, FDA-approved antiplatelet agents are recommended and preferred over anticoagulants. ASA, clopidogrel, and ASA + ER-DP are recognized as accepted first-line options for secondary prevention of noncardioembolic ischemic stroke. Combined antiplatelet therapy with ASA + clopidogrel has not been shown to carry benefit greater than risk in stroke or TIA patients. Aspirin and extended release dipyridamole appeared to carry a greater benefit over aspirin alone in individual studies, leading to a recommendation of this agent in the AHA guidelines, but the recently completed PRoFESS trial showed no difference in efficacy between clopidogrel and aspirin with extended release dipyridamole, and clopidogrel had better tolerability and reduced bleeding risk.
Pharmacotherapy of Bipolar I Disorder: Focus on Aripiprazole
Authors: Bastiaens Leo
Published: November 2017

Bipolar disorder is a common and complex condition, starting early in life and continuing throughout the life cycle. Most people suffering from bipolar disorder manifest other problems as well, including metabolic disturbances, cardiovascular disease, anxiety disorders, substance use disorders, attention deficit hyperactivity disorder, and borderline personality disorder, among others. The treatment of bipolar disorder needs to be conceptualized within this context of early onset, chronic course, and significant co-morbidity. Because of its unique mode of action, its efficacy and its good tolerability profile, aripiprazole is well placed among the different treatment options to benefit the patient with bipolar disorder. This article will focus on aripiprazole's pharmacology, efficacy, effectiveness, and tolerability from a clinical perspective, while considering the complexities of bipolar disorder.
Management of Asthma with ICS and LABAs: Different treatment strategies
Authors: Van Den Berge M , Ten Hacken NHT , Kerstjens HAM , Postma DS
Published: November 2017

In recent years considerable insight has been gained in the optimal management of adult asthma. In asthma patients who have persistent symptoms despite the daily use of (a low dose) inhaled corticosteroids (ICS), adding a long-acting β2-agonist to ICS improves asthma control and decreases the number of exacerbations. Currently two different LABAs are available, ie formoterol and salmeterol. The most important difference between both LABAs is a more rapid onset of action of formoterol (2-5 minutes) when compared to salmeterol (15-30 minutes). Partly based on these pharmacological differences, two major different approaches have been put forward to asthma management. The first approach (Gaining Optimal Asthma Control) is promoted by the producers of fluticasone/salmeterol and recommends to step up ICS to the dose needed to achieve optimal asthma control in order to keep the patient symptom free and to prevent exacerbations. The second approach is promoted by the producers of budesonide/formoterol and recommends a low maintenance dose which can be adjusted up or down according to the clinical control of asthma. Initially, a treatment strategy with Adjustable Maintenance Dosing with budesonide/formoterol was introduced. At a later time, this concept was changed to the Symbicort Maintenance And Reliever Therapy (SMART) approach. The aim of this manuscript is to review the current literature on the management of asthma with ICS and LABAs and to discuss the different treatment strategies.
Good News from Aliskiren?
Authors: Verdecchia Paolo , Angeli Fabio , Reboldi Gianpaolo
Published: November 2017

The renin-angiotensin system can be inhibited through inhibition of angiotensin I generation from angiotensinogen by direct renin inhibitors, inhibition of angiotensin II generation from angiotensin I by angiotensin-converting enzyme inhibitors and by direct inhibition of the action of angiotensin II receptor level. Aliskiren, the first direct renin inhibitor to reach the market, is a low molecular weight, orally active, hydrophilic nonpeptide. It blocks angiotensin I generation, while plasma renin concentration increases because the drugs blocks the negative feed-back exerted by angiotensin II on renin synthesis. Aliskiren is suitable for once-daily administration because of its long pharmacological half-life. Because of its mechanism of action, aliskiren may provide the additional opportunity to inhibit progression of atherosclerosis at tissue level. Hypertension is an approved indication for aliskiren, which is also promising for the treatment of heart failure and diabetic nephropathy. The efficacy of this drug on major clinical events is being tested in large ongoing clinical trials.
Safety and Efficacy of Didanosine Enteric-Coated Capsule in Patients with HIV-1 Infection
Authors: Arenas-Pinto Alejandro
Published: November 2017

Didanosine (ddl) has been used to treat HIV infection, in combination with other anti-retroviral drugs, for over 15 years. However, the use of the original formulation of ddI was limited by serious gastro-intestinal adverse effects, which were mainly attributable to the buffer used to protect ddI from the effect of gastric pH. Didanosine enteric-coated capsule (ddI-EC), a more recently introduced formulation, is less likely to cause gastrointestinal intolerance and its absorption might not be compromised by food intake. In this review we discuss efficacy of ddI-EC-containing anti-retroviral combinations (cART) both in naïve and previously treated patients. Because of its favorable resistance profile, ddI-EC has been shown to be potentially efficacious in rescuing patients in virological failure, even if they have nucleoside reverse transcriptase inhibitors (NRTI)-associated resistance mutations. However, ddI has been shown as a potent inducer of mitochondrial dysfunction. Peripheral neuropathy, severe hyperlactatemia and pancreatitis have all been described in patients exposed to ddI. Close monitoring of patients on ddI-EC-containing cART and low threshold for treatment modifications are required to prevent major complications. In the context of once daily cART, ddI-EC is a valid option, particularly when other agents are not available, or when other medical conditions preclude the use of drugs such as tenofovir or abacavir. The role of ddI-EC in second line cART may be even more important in resource-limited settings where additional options are lacking.
The Treatment of Ankylosing Spondylitis and Psoriatic Arthritis with Etanercept: A Comprehensive Review
Authors: Collamer Angelique N. , Battafarano Daniel F.
Published: November 2017

Etanercept is a dimeric recombinant soluble tumor necrosis factor (TNF) receptor protein utilized in the treatment of various inflammatory diseases, including ankylosing spondylitis and psoriatic arthritis. Etanercept binds the proinflammatory cytokine TNF and blocks its interaction with soluble TNF receptors, thus decreasing the inflammatory response. Several randomized controlled clinical trials have demonstrated the efficacy, safety and tolerability of etanercept in the treatment of both ankylosing spondylitis and psoriatic arthritis. These trials have also shown significant reductions in markers of systemic inflammation and improvements in patient-reported quality of life measures. Inhibition of radiographic progression has been established in etanercept-treated psoriatic arthritis patients, and ankylosing spondylitis patients have demonstrated decreases in bony inflammation; however, current data does not support a reduction in bone proliferation in ankylosing spondylitis patients. Concerns regarding long-term toxicity, efficacy, and cost-effectiveness considerations persist and guidelines have been published to assist the clinician with appropriate patient selection for this biologic therapy. Current data indicates etanercept therapy has been a very successful and well-tolerated therapy for numerous ankylosing spondylitis and psoriatic arthritis patients and will likely continue to be a cornerstone therapy for treatment of these challenging diseases in the foreseeable future.
Topical Testosterone Gel for the Treatment of Male Hypogonadism
Authors: Udeoji Dioma U. , Phan Anita , Katsiyiannis Peter , Willix Robert , Schwarz Ernst R.
Published: November 2017

Objective

This review describes the current knowledge of biological external testosterone (T) application using dermal products for the treatment of late-onset male hypogonadism (LOH).

Methods

An English language search of medical literature using Pubmed was conducted between January of 1984 and March of 2012 using the search term ‘testosterone gel’. Special emphasis was given to clinical controlled trials and large case studies.

Results

We describe the current knowledge on testosterone replacement therapy using gel applications. A reference search revealed 1567 publications; 44 were clinical studies in human patients with male hypogonadism, 80 were reviews, 27 were case reports, and 9 were retrospective studies. Data from the literature and from 20 clinical studies involving human patients were analyzed since they met the inclusion criteria of testosterone gel administration in hypogonadal males. For the purpose of this review, a total number of 2,378 human patients were studied. Overall, biological T administration resulted in improvement of sexual dysfunction and symptoms of metabolic syndrome and represented an effective and safe treatment option for hypogonadal men.

Conclusions

Administration of biological T gel appears to represent a valid alternative treatment option for male hypogonadism with a favorite efficacy and safety profile.
Profiling of Saharan dust from the Caribbean to western Africa – Part 1: Layering structures and optical properties from shipborne polarization/Raman lidar observations
Authors: Rittmeister Franziska , Ansmann Albert , Engelmann Ronny , Skupin Annett , Baars Holger , Kanitz Thomas , Kinne Stefan
Published: November 2017

Abstract. We present final and quality-assured results of multiwavelength polarization/Raman lidar observations of the Saharan air layer (SAL) over the tropical Atlantic. Observations were performed aboard the German research vessel R/V Meteor during the 1-month transatlantic cruise from Guadeloupe to Cabo Verde over 4500 km from 61.5 to 20° W at 14–15° N in April–May 2013. First results of the shipborne lidar measurements, conducted in the framework of SALTRACE (Saharan Aerosol Long-range Transport and Aerosol–Cloud Interaction Experiment), were reported by Kanitz et al.(2014). Here, we present four observational cases representing key stages of the SAL evolution between Africa and the Caribbean in detail in terms of layering structures and optical properties of the mixture of predominantly dust and aged smoke in the SAL. We discuss to what extent the lidar results confirm the validity of the SAL conceptual model which describes the dust long-range transport and removal processes over the tropical Atlantic. Our observations of a clean marine aerosol layer (MAL, layer from the surface to the SAL base) confirm the conceptual model and suggest that the removal of dust from the MAL, below the SAL, is very efficient. However, the removal of dust from the SAL assumed in the conceptual model to be caused by gravitational settling in combination with large-scale subsidence is weaker than expected. To explain the observed homogenous (height-independent) dust optical properties from the SAL base to the SAL top, from the African coast to the Caribbean, we have to assume that the particle sedimentation strength is reduced and dust vertical mixing and upward transport mechanisms must be active in the SAL. Based on lidar observations on 20 nights at different longitudes in May 2013, we found, on average, MAL and SAL layer mean values (at 532 nm) of the extinction-to-backscatter ratio (lidar ratio) of 17±5 sr (MAL) and 43±8 sr (SAL), of the particle linear depolarization ratio of 0.025±0.015 (MAL) and 0.19±0.09 (SAL), and of the particle extinction coefficient of 67±45 Mm−1 (MAL) and 68±37 Mm−1 (SAL). The 532 nm optical depth of the lofted SAL was found to be, on average, 0.15±0.13 during the ship cruise. The comparably low values of the SAL mean lidar ratio and depolarization ratio (compared to typical pure dust values of 50–60 sr and 0.3, respectively) in combination with backward trajectories indicate a smoke contribution to light extinction of the order of 20 % during May 2013, at the end of the burning season in central-western Africa.
Sources and oxidative potential of water-soluble humic-like substances (HULISWS) in fine particulate matter (PM2.5) in Beijing
Authors: Ma Yiqiu , Cheng Yubo , Qiu Xinghua , Cao Gang , Fang Yanhua , Wang Junxia , Zhu Tong , Yu Jianzhen , Hu Di
Published: November 2017

Abstract. Water-soluble humic-like substances (HULISWS) are a major redox-active component of ambient fine particulate matter (PM2.5); however, information on their sources and associated redox activity is limited. In this study, total HULISWS, various HULISWS species, and HULISWS-associated dithiothreitol (DTT) activity were quantified in PM2.5 samples collected during a 1-year period in Beijing. Strong correlation was observed between HULISWS and DTT activity; both exhibited higher levels during the heating season than during the non-heating season. Positive matrix factorization analysis of both HULISWS and DTT activity was performed. Four combustion-related sources, namely coal combustion, biomass burning, waste incineration, and vehicle exhaust, and one secondary factor were resolved. In particular, waste incineration was identified as a source of HULISWS for the first time. Biomass burning and secondary aerosol formation were the major contributors (> 59 %) to both HULISWS and associated DTT activity throughout the year. During the non-heating season, secondary aerosol formation was the most important source, whereas during the heating season, the predominant contributor was biomass burning. The four combustion-related sources accounted for > 70 % of HULISWS and DTT activity, implying that future reduction in PM2.5 emissions from combustion activities can substantially reduce the HULISWS burden and their potential health impact in Beijing.
Simulation of the Ozone Monitoring Instrument aerosol index using the NASA Goddard Earth Observing System aerosol reanalysis products
Authors: Colarco Peter R. , Gassó Santiago , Ahn Changwoo , Buchard Virginie , da Silva Arlindo M. , Torres Omar
Published: November 2017

Abstract. We provide an analysis of the commonly used Ozone Monitoring Instrument (OMI) aerosol index (AI) product for qualitative detection of the presence and loading of absorbing aerosols. In our analysis, simulated top-of-atmosphere (TOA) radiances are produced at the OMI footprints from a model atmosphere and aerosol profile provided by the NASA Goddard Earth Observing System (GEOS-5) Modern-Era Retrospective Analysis for Research and Applications aerosol reanalysis (MERRAero). Having established the credibility of the MERRAero simulation of the OMI AI in a previous paper we describe updates in the approach and aerosol optical property assumptions. The OMI TOA radiances are computed in cloud-free conditions from the MERRAero atmospheric state, and the AI is calculated. The simulated TOA radiances are fed to the OMI near-UV aerosol retrieval algorithms (known as OMAERUV) is compared to the MERRAero calculated AI. Two main sources of discrepancy are discussed: one pertaining to the OMI algorithm assumptions of the surface pressure, which are generally different from what the actual surface pressure of an observation is, and the other related to simplifying assumptions in the molecular atmosphere radiative transfer used in the OMI algorithms. Surface pressure assumptions lead to systematic biases in the OMAERUV AI, particularly over the oceans. Simplifications in the molecular radiative transfer lead to biases particularly in regions of topography intermediate to surface pressures of 600 and 1013.25 hPa. Generally, the errors in the OMI AI due to these considerations are less than 0.2 in magnitude, though larger errors are possible, particularly over land. We recommend that future versions of the OMI algorithms use surface pressures from readily available atmospheric analyses combined with high-spatial-resolution topographic maps and include more surface pressure nodal points in their radiative transfer lookup tables.
Retrieval of Total Water Vapour in the Arctic Using Microwave Humidity Sounders
Authors: Scarlat Raul Cristian , Melsheimer Christian , Heygster Georg
Published: November 2017

Abstract. Quantitative retrievals of atmospheric water vapour in the Arctic are faced with numerous challenges because of the particular climate characteristics of this area. Here, we attempt to build upon the work of Melsheimer and Heygster (2008) to retrieve total atmospheric water vapour (TWV) in the Arctic from satellite microwave radiometers. While the above mentioned algorithm deals primarily with the ice-covered central Arctic, with this work we are aiming to extend the coverage to low ice cover and ice-free areas. By using modeled values for the microwave emissivity of the ice-free sea surface, we develop two sub-algorithms using different sets of channels that deal solely with open ocean areas. This approach allows us to apply the algorithm to regions where previously no data were available and ensures a more consistent physical analysis of the satellite measurements by taking into account the contribution of the surface emissivity to the measured signal.
Comparison of aerosol optical depth from satellite (MODIS), Sun photometer and pyrheliometer ground-based measurements in Cuba
Authors: Antuña-Marrero Juan Carlos , Cachorro Revilla Victoria , García Parrado Frank , de Frutos Baraja Ángel , Rodríguez Vega Albeth , Mateos David , Estevan Arredondo René , Toledano Carlos
Published: November 2017

Abstract. In the present study, we report the first comparison of the aerosol properties measured with sun photometer at Camagüey, Cuba, with the MODerate resolution Imaging Spectroradiometer (MODIS) instruments on Terra and Aqua satellites. We compared the aerosol optical depth at 550 nm (AOD) and the Ångström Exponent (AE) from the sun photometer for the period 2008 to 2014 with the same variables measured by both MODIS instruments, that are spatially and temporally coincident. The comparison includes AOD derived with both Deep Blue (DB) and Dark Target (DT) algorithms from MODIS Collection 6. The AOD derived with DT algorithm for Terra and Aqua agrees better with AOD from the sun photometer than the AOD derived with DB. Additionally there is little difference between AOD from both satellite instruments, when they are compared with sun photometer AOD, allowing to combine AOD from Terra and Aqua for more comprehensive climatological statistics. The comparison of the AE showed similar results with reports in the literature about the little skills of the current DT and DB algorithms for its retrieval. In addition, we report the comparison of the broadband AOD (BAOD) from pyrheliometer measurements located at Camagüey site and other three meteorological stations along Cuba, with AOD measurements from the sun photometer and from MODIS onboard Terra and Aqua. The comparison of the BAOD from the four sites as a whole with coincident AOD from MODIS onboard Terra and Aqua showed similar results than the ones of the comparison between the sun photometer AOD and the AOD from the two satellite instruments. In the comparison between the BAOD and the AOD at each one of the eight individual sun photometer wavelengths, the results improve in the spectral range 400 to 675 nm, with the best result at 500 nm. The BAOD typical uncertainty ranges from 0.04 to 0.06 at this band. The results from the BAOD comparisons demonstrate its reliability for characterizing AOD at sites with no sun photometer and for extending backward in time AOD estimates.
Large to submesoscale surface circulation and its implications on biogeochemical/biological horizontal distributions during the OUTPACE cruise (SouthWest Pacific)
Authors: Rousselet Louise , de Verneil Alain , Doglioli Andrea M. , Petrenko Anne A. , Duhamel Solange , Maes Christophe , Blanke Bruno
Published: November 2017

Abstract. The patterns of the large-scale, meso- and submesoscale surface circulation on biogeochemical and biological distributions are examined in the Western Tropical South Pacific (WTSP) in the context of the OUTPACE cruise (Feb–April 2015). Multi-disciplinary original in situ observations were achieved along a zonal transect through the WTSP and their analysis was coupled with satellite data. The use of Lagrangian diagnostics allows for the identification of water mass pathways, mesoscale structures, and submesoscale features such as fronts. In particular, we confirmed the existence of a global wind-driven southward circulation of surface waters in the entire WTSP, using a new high-resolution altimetry-derived product, validated by in situ drifters, that includes cyclogeostrophy and Ekman components with geostrophy. Two subregions show counter-intuitive water mass trajectories due to mesoscale circulation: i) the Coral Sea with surface exchanges between the North Vanuatu Jet and the North Caledonian Jet; and ii) the zonal band between 180° W and 170° W with an eastward propagation whereas a westward general direction dominates. Fronts and small-scale features, detected with Finite-Size Lyapunov Exponents (FSLE), are correlated with 25 % of surface tracer gradients which reveals the significance of such structures in the generation of submesoscale surface gradients. Additionally, two high-frequency sampling transects of biogeochemical parameters and micro-organism abundances demonstrate the influence of fronts in controlling the spatial distribution of bacteria and phytoplankton, and as a consequence the microbial community structure. All circulation scales play an important role that has to be taken into account when analysing the data from OUTPACE but also, more generally, to understand the global distribution of biogeochemical components.
Central Arctic Ocean paleoceanography from  ∼  50 ka to present, on the basis of ostracode faunal assemblages from the SWERUS 2014 expedition
Authors: Gemery Laura , Cronin Thomas M. , Poirier Robert K. , Pearce Christof , Barrientos Natalia , O'Regan Matt , Johansson Carina , Koshurnikov Andrey , Jakobsson Martin
Published: November 2017

Abstract. Late Quaternary paleoceanographic changes at the Lomonosov Ridge, central Arctic Ocean, were reconstructed from a multicore and gravity core recovered during the 2014 SWERUS-C3 Expedition. Ostracode assemblages dated by accelerator mass spectrometry (AMS) indicate changing sea-ice conditions and warm Atlantic Water (AW) inflow to the Arctic Ocean from  ∼  50 ka to present. Key taxa used as environmental indicators include Acetabulastoma arcticum (perennial sea ice), Polycope spp. (variable sea-ice margins, high surface productivity), Krithe hunti (Arctic Ocean deep water), and Rabilimis mirabilis (water mass change/AW inflow). Results indicate periodic seasonally sea-ice-free conditions during Marine Isotope Stage (MIS) 3 ( ∼  57–29 ka), rapid deglacial changes in water mass conditions (15–11 ka), seasonally sea-ice-free conditions during the early Holocene ( ∼  10–7 ka) and perennial sea ice during the late Holocene. Comparisons with faunal records from other cores from the Mendeleev and Lomonosov ridges suggest generally similar patterns, although sea-ice cover during the Last Glacial Maximum may have been less extensive at the new Lomonosov Ridge core site ( ∼  85.15° N, 152° E) than farther north and towards Greenland. The new data provide evidence for abrupt, large-scale shifts in ostracode species depth and geographical distributions during rapid climatic transitions.
Trends and regime shifts in climatic conditions and river runoff in Estonia during 1951–2015
Authors: Jaagus Jaak , Sepp Mait , Tamm Toomas , Järvet Arvo , Mõisja Kiira
Published: November 2017

Abstract. Time series of monthly, seasonal and annual mean air temperature, precipitation, snow cover duration and specific runoff of rivers in Estonia are analysed for detecting of trends and regime shifts during 1951–2015. Trend analysis is realised using the Mann–Kendall test and regime shifts are detected with the Rodionov test (sequential t-test analysis of regime shifts). The results from Estonia are related to trends and regime shifts in time series of indices of large-scale atmospheric circulation. Annual mean air temperature has significantly increased at all 12 stations by 0.3–0.4 K decade−1. The warming trend was detected in all seasons but with the higher magnitude in spring and winter. Snow cover duration has decreased in Estonia by 3–4 days decade−1. Changes in precipitation are not clear and uniform due to their very high spatial and temporal variability. The most significant increase in precipitation was observed during the cold half-year, from November to March and also in June. A time series of specific runoff measured at 21 stations had significant seasonal changes during the study period. Winter values have increased by 0.4–0.9 L s−1 km−2 decade−1, while stronger changes are typical for western Estonia and weaker changes for eastern Estonia. At the same time, specific runoff in April and May have notably decreased indicating the shift of the runoff maximum to the earlier time, i.e. from April to March. Air temperature, precipitation, snow cover duration and specific runoff of rivers are highly correlated in winter determined by the large-scale atmospheric circulation. Correlation coefficients between the Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) indices reflecting the intensity of westerlies, and the studied variables were 0.5–0.8. The main result of the analysis of regime shifts was the detection of coherent shifts for air temperature, snow cover duration and specific runoff in the late 1980s, mostly since the winter of 1988/1989, which are, in turn, synchronous with the shifts in winter circulation. For example, runoff abruptly increased in January, February and March but decreased in April. Regime shifts in annual specific runoff correspond to the alternation of wet and dry periods. A dry period started in 1964 or 1963, a wet period in 1978 and the next dry period at the beginning of the 21st century.
DebrisInterMixing-2.3: a finite volume solver for three-dimensional debris-flow simulations with two calibration parameters – Part 2: Model validation with experiments
Authors: von Boetticher Albrecht , Turowski Jens M. , McArdell Brian W. , Rickenmann Dieter , Hürlimann Marcel , Scheidl Christian , Kirchner James W.
Published: November 2017

Abstract. Here, we present validation tests of the fluid dynamic solver presented in von Boetticher et al. (2016), simulating both laboratory-scale and large-scale debris-flow experiments. The new solver combines a Coulomb viscoplastic rheological model with a Herschel–Bulkley model based on material properties and rheological characteristics of the analyzed debris flow. For the selected experiments in this study, all necessary material properties were known – the content of sand, clay (including its mineral composition) and gravel as well as the water content and the angle of repose of the gravel. Given these properties, two model parameters are sufficient for calibration, and a range of experiments with different material compositions can be reproduced by the model without recalibration. One calibration parameter, the Herschel–Bulkley exponent, was kept constant for all simulations. The model validation focuses on different case studies illustrating the sensitivity of debris flows to water and clay content, channel curvature, channel roughness and the angle of repose. We characterize the accuracy of the model using experimental observations of flow head positions, front velocities, run-out patterns and basal pressures.
Intercomparison of different uncertainty sources in hydrological
climate change projections for an alpine catchment (Clutha River,
New Zealand)
Authors: Jobst Andreas M. , Kingston Daniel G. , Cullen Nicolas J. , Schmid Josef
Published: November 2017

Abstract. As climate change is projected to alter both temperature and precipitation, snow controlled mid-latitude catchments are expected to experience substantial shifts in their seasonal regime, which will have direct implications for water management. In order to provide authoritative projections of climate change impacts, the uncertainty inherent to all components of the modelling chain needs to be accounted for. This study assesses the uncertainty in potential impacts of climate change on the hydro-climate of New Zealand’s largest catchment (the Clutha River) using a fully distributed hydrological model (WaSiM) and unique ensemble encompassing different uncertainty sources: General Circulation Model (GCM), emission scenario, bias correction and snow model. The inclusion of snow models is particularly important, given that (1) they are a rarely considered aspect of uncertainty in hydrological modelling studies, and (2) snow has a considerable influence on seasonal patterns of river flow in alpine catchments such as the Clutha. Projected changes in river flow for the 2050s and 2090s encompass substantial increases in streamflow from May to October, and a decline between December and March. The dominant drivers are changes in the seasonal distribution of precipitation (for the 2090s +25 to +76 % in winter) and substantial decreases in the seasonal snow storage due to temperature increase. A quantitative comparison of uncertainty identified GCM structure as the dominant contributor in the seasonal streamflow signal (44–57 %) followed by emission scenario (16–49 %), bias correction (4–22 %) and snow model (3–10 %). While these findings suggest that the role of the snow model is comparatively small, its contribution to the overall uncertainty was still found to be noticeable for winter and summer.