bluuebunny/crossref_metadata_2025 huggingface dataset:
Research Methods in Practice: The Development of Problem-Based Learning Materials for Teaching Qualitative Research Methods to Undergraduate Students
Authors: Wiggins Sally , Burns Victoria
Published: November 2010

Research methods is often considered one of the more challenging subjects to teach (and learn), yet it is arguably the most important; to equip students with the skills to carry out their own research is a fundamental aspect of many psychology courses. The issues raised by qualitative research methods teaching in particular – differing epistemologies, challenging ‘objectivity’ and alternative validation practices – pose further challenges for students. In this article, we report on a project that applies problem-based learning (PBL) principles to qualitative research methods teaching. PBL has already been effectively used in many other disciplines as a way to encourage student autonomy within the learning process and to deepen understanding of key issues, and there is a huge potential for its application within research methods teaching. We report on each stage of the project: a review of PBL and research methods teaching literature, a preliminary survey of current PBL use in UK psychology departments, and an outline of the drafted PBL materials.
SUMS: A Flexible Approach to the Teaching and Learning of Statistics
Authors: Swingler Maxine V. , Bishop Paul , Swingler Kevin M.
Published: November 2010

Statistical Understanding Made Simple (SUMS) ( http://www.gla.ac.uk/sums ) is an online statistics tutorial generator which covers basic statistical concepts and focuses on applying these concepts to real data. Instructors can upload their own data to the site, and students choose the level at which they want to work from one of three levels. SUMS adopts a teaching approach where each concept is explained, the student explores the concept with an interactive game, and then applies their knowledge to a concrete example (using data provided by the instructor). SUMS was evaluated to determine its effectiveness as a stand-alone resource for psychology students and as a resource to support a psychology laboratory class, using a measure of statistics self-efficacy (based on Finney & Schraw, 2003) and a statistics comprehension test. Results of the evaluation showed that overall, SUMS had a positive impact on students' statistics comprehension and self-efficacy.
Facilitating Collaborative Learning Using Online Wikis: Evaluation of Their Application Within Postgraduate Psychology Teaching
Authors: Hulbert-Williams Nicholas J.
Published: November 2010

Virtual learning environments (VLEs) are helpful in achieving a blended learning approach to higher education. Online wikis are proposed as a potentially useful method to encourage collaborative learning through the VLE. The present study integrated wiki software into a module for Masters-level applied psychology students. Seventeen students participated in a week-long online group-based wiki task as a standard part of their course. The use of wiki technology to develop an innovative research idea was evaluated both by analysis of output (tracking of engagement with the intervention) and by self-report questionnaire (evaluation of the intervention) collected from a subsample of 14 students. Results indicate that the students enjoyed the task and perceived educational benefit from it. However, the content of the wikis created suggests that the instructions given to the students may not have been clear enough, and in particular that students were unsure of what the nature and purpose of a wiki is. Students clearly needed more preparatory training in using this technology, and clearer explanation of expected outputs, before beginning this task. This study provides further evidence that students benefit from, and enjoy, blended learning approaches and that wikis represent a useful way to integrate blended and collaborative learning principles.
But I'm No Expert! Peer Assessment by First-Year Psychology Undergraduates
Authors: Kingsley Barbara
Published: November 2010

The inclusion of peer assessment in an overall programme of assessment can offer benefits to learning. In the current study students' perceptions of peer assessment were evaluated and their ability accurately to assess others' work measured. From a cohort of first-year undergraduate psychology students, data regarding positive and negative aspects of the peer assessment process allowed a 21 item peer assessment questionnaire to be developed. Fifty-seven participants completed the questionnaire, and two weeks later marks given by those students during a peer assessment exercise were compared to marks awarded by experienced tutors for the same pieces of work. Findings from a comparison of student and tutor marks are discussed in terms of students' critical evaluation skills.
Defining Asbestos: Differences between the Built and Natural Environments
Authors: Gunter Mickey E.
Published: November 2010

Asbestos – while most think they know what this material is, few understand the current issues surrounding it. Few would also realize that asbestos is the form of a mineral, and even fewer would know that there are different types of asbestos, that not only had different industrial
applications, but pose differing health risks when inhaled. Asbestos was in wide-spread use mid-last century in many consumer products, and no doubt saved thousands of lives, but by the latter part of last century concerns over its health risk caused its use to wane, to the point it was removed
from many buildings. So in many ways the asbestos story was coming to an end in the 1990s, but two events in the USA – the vermiculite ore produced from Libby, Montana which contained amphibole asbestos and was used in a million homes in the USA as attic insulation and the concern for
exposure to asbestos occurring in its natural setting in El Dorado Hills, California led to an increased concern of the potential for low-level environmental exposure to asbestos to the general public. The current dilemma we find ourselves in, especially in the USA, deals with the relationships
between our knowledge of handling asbestos and an understanding of its risk potential in the built environment versus the natural environment. And one perfect metaphor for this is the term used by many non-geologists to differentiate asbestos in the built vs natural environment – 'naturally
occurring asbestos'. Clearly a misstatement, but only one of many we must deal with as we struggle to understand the risk to humans of natural occurrences of asbestos. This paper will try and address some of these issues centering around those occurring in the USA.
Quantification of the Total Amount of Artemisinin in Leaf Samples by Thin Layer Chromatography
Authors: Quennoz Mélanie , Bastian Christèle , Simonnet Xavier , Grogg Alain F.
Published: November 2010

Artemisinin is a natural molecule highly active against malaria. At present, the extraction of this molecule from the leaves of Artemisia annua L. remains the only viable method to produce cheaply large quantities of artemisinin. Agronomic research on this plant species aims
to improve agricultural yields, to decrease production costs and to ensure a steady global supply of artemisinin. These research activities require an easy, rapid, low cost, and reliable analytical technique to quantify the artemisinin content in the leaves. Thin layer chromatography (TLC)
methods to quantify this molecule have already been published. However, this method does not allow the quantification of the total artemisinin content in the leaves. In order to validate the TLC method, results obtained with this method were related to results for the same samples obtained
by accelerated solvent extraction and high pressure liquid chromatography with an evaporative light scattering detector (ASE-HPLC-ELSD). Using the Nernst partition law, a corrective factor of 1.21 is suggested to enable information about the true total amount of artemisinin in leaf samples
to be obtained within a range of 0.25 to 3%. In conclusion, this study proposes for the first time a corrective factor in order to quantify the total artemisinin content of A. annua leaves with TLC.
Flavonoids from Halostachys caspica and Their Antimicrobial and Antioxidant Activities
Authors: Liu Hao , Mou Yan , Zhao Jianglin , Wang Jihua , Zhou Ligang , Wang Mingan , Wang Daoquan , Han Jianguo , Yu Zhu , Yang Fuyu
Published: November 2010

Seven flavonoids have been isolated from the aerial parts of Halostachys caspica C. A. Mey. (Chenopodiaceae) for the first time. By means of physicochemical and spectrometric analysis, they were identified as luteolin (1), chrysin (2), chrysin 7-O-β-D-glucopyranoside (3), quercetin (4), quercetin 3-O-β-D-glucopyranoside (5), isorhamentin-3-O-β-D-glucopyranoside (6), and isorhamentin-3-O-β-D-rutinoside (7). All flavonoids were evaluated to show a broad antimicrobial spectrum of activity on microorganisms including seven bacterial and one fungal species as well as pronounced antioxidant activity. Among them, the aglycones with relatively low polarity had stronger bioactivity than their glycosides. The results suggested that the isolated flavonoids could be used for future development of antimicrobial and antioxidant agents, and also provided additional data for supporting the use of H. caspica as forage.
Seven Years’ Observation of Mid-Upper Tropospheric Methane from Atmospheric Infrared Sounder
Authors: Xiong Xiaozhen , Barnet Chris , Maddy Eric , Wei Jennifer , Liu Xingpin , Pagano Thomas S.
Published: November 2010

The Atmospheric Infrared Sounder (AIRS) on EOS/Aqua platform provides a measurement of global methane (CH4) in the mid-upper troposphere since September, 2002. As a thermal infrared sounder, the most sensitivity of AIRS to atmospheric CH4 is in the mid-upper troposphere with the degree of freedom of ~1.0. Validation of AIRS CH4 product versus thousands of aircraft profiles (convolved using the AIRS averaging kernels) demonstrates that its RMS error (RMSE) is mostly less than 1.5%, and its quality is pretty stable from 2003 to 2009. For scientific analysis of the spatial and temporal variation of mid-upper tropospheric CH4 (MUT-CH4) in the High Northern Hemisphere (HNH), it is more valuable to use the AIRS retrieved CH4 in a layer of about 100 hPa below tropopause (“Representative Layer”) than in a fixed pressure layer. Further analysis of deseasonalized time-series of AIRS CH4 in both a fixed pressure layer and the “Representative Layer” of AIRS (only for the HNH) from 2003 to 2009 indicates that, similar to the CH4 in the marine boundary layer (MBL) that was found to increase in 2007–2008, MUT-CH4 was also observed to have a recent increase but the most significant increase occurred in 2008. MUT-CH4 continued to increase in 2009, especially in the HNH. Moreover, the trend of MUT-CH4 from 2006 to 2008 is lower than the trend of CH4 in the MBL by 30–40% in both the southern hemisphere and HNH. This delay for the MUT-CH4 increase of about one year than CH4 in the MBL as well as the smaller increase trend for MUT-CH4 suggest that surface emission is likely a major driver for the recent CH4 increase. It is also found that the seasonal cycle of MUT-CH4 is different from CH4 in the MBL due to the impact of transport, in addition to the surface emission and the photochemical loss.
A Comparison Between Methods of Selecting Cluster Head
Authors: Brisha Ayman Mohammd
Published: November 2010

In wireless sensor networks (WSNs), hierarchical network structures have the advantage of providing scalable and resource efficient solutions. The routing methods which are used in the wireless sensor networks deal with clustering methods to diminish the amount of data transmission from the perspective of energy efficiency. Cluster-based architecture provide an effective architecture for data-gathering in wireless sensor networks. Dynamic clustering is a method which are used to supplement the problem of a high energy demands by distributing energy consumption through the re-selection of the cluster head node. However, this method modifies the cluster structure each time the cluster head node is re-selected, thereby increasing energy demands. In this paper we present a comparison between Selecting Cluster Head Randomly (SCHR) and Well Selected Cluster Heads (WSCH). The results had indicated that, WSCH methods perform better than the SCHR.
Pharmacotherapy of Narcolepsy: Focus on Sodium Oxybate
Authors: Kothare Sanjeev V. , Kaleyias Joseph
Published: November 2010

Narcolepsy is a complex disease with multiple symptoms that include excessive daytime sleepiness, cataplexy, hypnagogic hallucinations, and sleep paralysis. Pharmacologic management of patients with narcolepsy is based on treating these symptoms. Sodium oxybate, a neurotransmitter product of γ-amino butyric acid (GABA), is a Schedule III controlled substance in the US, approved for the treatment of excessive daytime sleepiness (EDS), and cataplexy in patients with narcolepsy. The purpose of this review is to summarize the current knowledge about treatment of narcolepsy with sodium oxybate and to familiarize readers with the safety and efficacy of sodium oxybate, thus enabling clinicians to optimize their management of narcolepsy. A review of the pharmacokinetics, pharmacodynamics, efficacy in different symptoms of narcolepsy, adverse effects, tolerability, and dosing of sodium oxybate is presented. Sodium oxybate administered as an oral solution has a rapid onset of effect, a short duration of action, and nearly complete metabolism with negligible unchanged γ-hydroxybutyrate (GHB) appearing in the urine. There is mounting evidence suggesting that GHB may function as an endogenous neuromodulator/neurotransmitter. The mechanism by which sodium oxybate has a therapeutic effect in narcolepsy is unclear. The efficacy of oral sodium oxybate on the treatment of narcolepsy was evaluated in two randomized, double-blind, placebo- controlled, multicenter, US and International trials. Treatment of patients with narcolepsy-cataplexy with sodium oxybate leads to reduction in the frequency of cataplexy attacks in a dose-related manner, improved EDS, increased level of alertness and ability to concentrate. The major problem with sodium oxybate remains in its potential for non-medical use to elicit altered states of consciousness; however, abuse and misuse of sodium oxybate has been rare over the 7 years since its introduction in the market. Other issues revolve around twice nightly dosing, and salty taste. The most commonly reported adverse events associated with the use of sodium oxybate and occurring with at least 5% greater frequency than seen in placebo-treated patients were dizziness, headache, nausea, pain, night terrors, enuresis, confusion, infection, vomiting, and urinary incontinence. In conclusion, sodium oxybate significantly improves all symptoms in patients with narcolepsy and is well tolerated.
Pharmacotherapy Update: Treatment of HIV Infection with Darunavir
Authors: Viganò A. , Manfredini V. , Mameli C. , Giacomet V. , Zuccotti G.V.
Published: November 2010

Darunavir is an oral peptidomimetic HIV-1 protease inhibitor with antiretroviral activity against wild type HIV strains and HIV strains with protease inhibitor mutations. Ritonavir-boosted darunavir is rapidly absorbed and it has a higher bioavailability than unboosted darunavir. In HIV infected adults, the pharmacokinetic profile of darunavir showed that the drug concentrations are similar in the age range between 18 to 65 years and unaffected by the presence of moderate renal or hepatic function impairment. Darunavir chemical structure provides a strong interaction between the drug and HIV-1 protease and accounts for its potent antiretroviral activity and high genetic barrier to the development of resistance. The efficacy, safety and tolerability of darunavir have been widely demonstrated in HIV-infected treatment-experienced and naïve adult patients and it's use has been labelled in this population. Recently, upon the approval of the Food and Drug Administration, a 75 mg darunavir's tablet formulation has been licensed for the treatment of HIV-infected children and adolescents in the age range between 6 to 17 years.
Present and Prospective Clinical Therapeutic Options for the Elderly Patient with Hypertension
Authors: Lechleitner Monika , Hoppichler Friedrich
Published: November 2010

Purpose

The purpose of this review was to summarize current treatment guidelines and recently published studies about the efficacy and safety of antihypertensive therapy in elderly patients.

Methods

A literature research (MEDLINE) was performed with respect to the prevalence of hypertension in the elderly, the underlying pathophysiological mechanisms and current treatment options.

Results

Hypertension affects up to 70% of the population aged 65 years and older and results in a significant increase of cardiovascular morbidity and mortality. Antihypertensive drug therapy reduces the risk of cardiovascular complication and end organ damage not only in younger, but also in elderly patients. The most frequently applied classes of antihypertensive medication are diuretics, beta-blockers, ACE-inhibitors, angiotensin II-AT1-receptor blockers, calcium channel blockers, alpha-adrenergic receptor antagonists, centrally acting drugs and vasodilators. Side effects of antihypertensive medication have to be considered especially in the vulnerable elderly patients. The recently published HYVET study added important information on the value of antihypertensive therapy in patients at an age of 80 years or older. In the treatment group with indapamide and periondopril (compared to the placebo group) the risk of stroke was reduced by 30%, all-cause mortality by 21% and cardiovascular mortality by 23%.

Conclusion

Co-morbidities and age related changes of pharmacokinetics and pharmacodynamics require a very distinct choice of therapy in elderly people. Individual drug classes might be of advantage in certain conditions, including diabetes mellitus, renal dysfunction, heart failure and stroke.
Pharmacotherapy of Chronic Heart Failure in the Elderly: A Review of the Evidence
Authors: Ripley Toni L. , Hennebry Thomas A.
Published: November 2010

Heart failure (HF) is a very prevalent disease in the United States and in Europe, with the highest prevalence among older patients. Population estimates suggest substantial growth among the elderly over the next four decades. However, older patients are underrepresented in clinical trials evaluating HF therapies and are less likely to receive the medications shown in these trials to reduce the morbidity and mortality associated with HF. Age-related differences exist in cardiovascular function that may affect disease progression, clinical presentation, and/or response to therapy. Further, medication use in older patients is complicated by physiologic changes in pharmacokinetics and the presence of multiple co-morbidities, which leads to polypharmacy and the related complications. We reviewed the pharmacotherapy clinical trials in HF to review the results specifically in older patients. Trials were included in this review if clinical endpoints were evaluated, if data regarding the participants’ age was reported, and if the intervention studied was in a medication class that is generally recommended for patients with HF by published guidelines. Although some non-randomized data shows benefits of standard therapies may be maintained among patients with HF ≥ 60 years old, the randomized controlled trials that have been published to date showed no benefit and no harm in this group. Cautious HF management among older patients is critical as additional evidence is pursued.
Psychotropic Effects of Anticonvulsant Drugs in Patients with Epilepsy
Authors: Mula Marco
Published: November 2010

Anticonvulsant drugs continue to be the mainstay of epilepsy treatment but benefits of seizure control need to be balanced with the psychotropic potential of this class of compounds. The present paper is aimed at discussing positive and negative effects of anticonvulsant drugs on mood in patients with epilepsy. In general terms, the use in monotherapy, adopting slow titration schedules and low doses when possible, can significantly reduce the occurrence of treatment emergent adverse events. The mental state of the patient need to be taken into account in order to really optimize the anticonvulsant drug treatment.
Methadone Cardiotoxicity in Pain Management–-An Important Issue for Clinicians
Authors: Leppert Wojciech
Published: November 2010

Morphine or other strong opioids (fentanyl, oxycodone, hydromorphone, buprenorphine) are usually administered in patients with severe cancer and chronic non-malignant pain. However, when these analgesics are ineffective in terms of analgesia or induce intractable adverse effects, a switch to methadone might prove beneficial. Consequently methadone is used in opioid rotation (switch) when other opioids have failed. Methadone may be considered as the first strong opioid, especially in patients with neuropathic pain and renal failure. Still, methadone dosing is more difficult than dosing of other strong opioids due to unpredictable pharmacokinetics, numerous drug interactions and a possibility of QTc interval prolongation. Preferably, methadone should be prescribed by physicians experienced in cancer and chronic pain management. The knowledge on methadone cardiotoxicity among health care professionals is limited. The aim of this article is to outline methadone drug interactions and adverse effects with focus on the QTc interval prolongation. Several recommendations grounded in the literature review are provided to clinicians who use methadone in pain management.
Intranasal Ciclesonide in Allergic Rhinitis
Authors: Vliagoftis Harissios
Published: November 2010

Allergic rhinitis affects more than 20% and is responsible for very high direct and indirect costs. Nasal corticosteroids are the principle pharmaceutical option for the treatment of allergic rhinitis. They are more effective than all other therapeutic options and in addition to improving symptoms of allergic rhinitis they also improve quality of life in patients suffering from allergic rhinitis. There are many intranasal corticosteroids approved for the treatment of allergic rhinitis in pediatric and adult populations. Ciclesonide has shown so far a very good safety and pharmacokinetic profile and is effective for treatment of symptoms in both seasonal and perennial allergic rhinitis. This review summarizes the studies describing these effects of intranasal ciclesonide.
Muscarinic Receptor Antagonists, the Overactive Bladder and Efficacy against Urinary Urgency
Authors: Mansfield Kylie J.
Published: November 2010

The overactive bladder (OAB) is a debilitating condition in which patients suffer from urinary urgency, frequency and nocturia with or without urge urinary incontinence. The mainstay of pharmacotherapy for OAB is muscarinic receptor antagonists, which have been shown to be effective treatments for the symptoms of OAB. The mechanism underlying the efficacy of antimuscarinic agents against the symptoms of OAB is not completely understood. This review explores the role of bladder mucosal muscarinic receptors in the signaling pathways that are activated in response to bladder filling. The cholinergic system is seen to be involved in bladder afferent signaling at many levels and as such muscarinic receptor antagonists may affect bladder signaling via numerous pathways including release of mediators from the bladder urothelium and activation of suburothelial myofibroblasts and afferent nerves. Therefore the mucosal cholinergic system may represent another target for the antimuscarinic agents used to treat OAB.
A Review of Docetaxel: Its Use in the Treatment of Gastric Cancer
Authors: Inno Alessandro , Basso Michele , Cassano Alessandra , Barone Carlo
Published: November 2010

Docetaxel, a member of the taxane family, promotes cell death by binding β-tubulin and has demonstrated activity against several human malignancies, both as a single agent and in combination therapy. It has been approved in Europe and the US as front-line treatment for advanced gastric cancer in combination with cisplatin and fluorouracil (DCF regimen). This approval was based on the results of a pivotal study (V325) which demonstrated that the addition of docetaxel to the reference regimen of cisplatin and fluorouracil improves overall survival and progression-free survival with a better quality of life despite increased toxicity (mainly haematological). Modifications of DCF regimen have been successfully investigated as a means of making the treatment more tolerable and suitable also for elderly patients or patients with poor performance status. Emerging data from several phase II studies suggest that other docetaxel-based combination regimens with anthracyclines or irinotecan have interesting activity with acceptable toxicity profiles, but the true efficacy of these regimens needs to be assessed in large randomized phase III studies. Thus, the best docetaxel-containing regimen has yet to be identified. Docetaxel also represents a good candidate for combination with novel molecular target agents. In light of the high response rates observed in phase II-III studies, a docetaxel-based chemotherapy regimen might also be considered a treatment option as perioperative or adjuvant therapy in potentially curable gastric cancer and further studies with or without biological agents are eagerly awaited in this setting.
Treatment of Idiopathic Chronic Constipation and Irritable Bowel Syndrome with Constipation: What Role for Lubiprostone?
Authors: Ambizas Emily M. , Patel Priti N.
Published: November 2010

Lubiprostone is a novel chloride channel 2 activator indicated for the treatment of chronic idiopathic constipation in adults and constipation-predominant irritable bowel syndrome (IBS-C) in adult women. It is effective for chronic constipation at a dose of 24 mcg twice daily and for IBS-C at a dose of 8 mcg twice daily. Lubiprostone is well-tolerated, with nausea and headache being the most commonly reported adverse drug reactions. It also has a low potential for drug-drug interactions. Lubiprostone is a potential treatment for both disorders, which have few treatment options available. Studies of longer duration will help more firmly establish its use for these chronic conditions.
Treatment of Non-Small Cell Lung Cancer: Focus on Pemetrexed Disodium
Authors: Feliciano Josephine , Patel Jyoti
Published: November 2010

Pemetrexed (Alimta, Eli Lilly) is a multi-targeted anti-folate originally approved for its use in malignant mesothelioma. Based on results from phase III clinical investigations, it is now approved for use as a single agent in the second-line setting and in combination with platinum therapy in the first-line setting for advanced non-small cell lung cancer. It is also under investigation in earlier stages of non small cell lung cancer including in the adjuvant setting and with radiation. It has shown to be particularly efficacious for non-squamous histology and is well tolerated. Toxicity includes, but is not limited to hematologic toxicity and gastrointestinal toxicity, which are minimized by vitamin B12 and folic acid supplementation. Recent analyses also suggest cost-effectiveness of this agent in patient with advanced, non-squamous cell non-small cell lung cancer.
Efficacy and Safety of Galantamine Hydrobromide in the Treatment of Mild to Moderate Dementia
Authors: Oremus Mark , Santaguida Pasqualina , Raina Parminder
Published: November 2010

We conducted a systematic review and meta analysis of randomized controlled trials of galantamine hydrobromide in the treatment of mild to moderate dementia. Following a literature search and screening process, we included 15 trials and five companion papers in the review. Moderate-quality evidence suggested galantamine-treated persons generally had better outcomes than placebo-treated persons after a maximum 6-month follow-up. Outcome domains included cognitive function, global function, behaviour and mood, and activities of daily living. The evidence requires careful interpretation because ‘better outcomes’ can mean less deterioration, rather than improvement, relative to placebo. Galantamine has not been shown to halt dementia progression nor reverse disease course. The most frequently reported harms were nausea, diarrhea, and dizziness. Reported rates of these harms were highly variable (range, 0%–40%); reporting was at high risk of bias because authors rarely specified the frequency or timing of harms assessment, nor did they report active methods of collecting harms.
The annual cycle in lower stratospheric temperatures revisited
Authors: Fueglistaler S. , Haynes P. H. , Forster P. M.
Published: November 2010

Abstract. Observed lower stratospheric temperatures show a prominent annual cycle. The cycles in the tropics and Northern Hemisphere are in phase and the cycle in the Southern Hemisphere has the opposite phase. In an elegant and influential paper, Yulaeva, Holton and Wallace (1994) explained the observed pattern as a direct consequence of hemispheric asymmetries in the dynamical forcing of the stratospheric circulation. They showed that in Microwave Sounding Unit channel 4 (weighting centered in the lower stratosphere) data the combined extratropical and the tropical temperature cycle nearly compensate and interpreted the out-of-phase temperature variations between tropics and extratropics as the temperature response to an annual cycle in the wave driven residual circulation. We show that the near-compensation of temperature variations emphasised by Yulaeva et al. (1994) is artefact of the weighting function of the MSU-4 channel and does not hold on individual pressure levels. We discuss in detail the conditions required that temperature variations compensate, and what insights can be obtained from analysis of tropical, extratropical and global mean temperature variations. Dynamically induced seasonal variations of lower stratospheric ozone lead to an amplification of the seasonal temperature cycle particularly in the tropics. The latitudinal structure of thermal stratification also induces a significant deviation from compensation of tropical and combined extratropical temperature variations. In line with Yulaeva et al. (1994) we affirm that the see-saw pattern in the annual cycles of tropical and combined extratropical temperatures provides an important pointer to mechanistic models for interannual variability and trends, but additionally conclude that the latitudinal structure of stratification and the feedback of dynamically-induced ozone variations on temperatures should be included as leading order processes in such models.
Influence of meteorology on PM10 trends and variability in Switzerland from 1991 to 2008
Authors: Barmpadimos I. , Hüglin C. , Keller J. , Henne S. , Prévôt A. S. H.
Published: November 2010

Abstract. Measurements of airborne particles with aerodynamic diameter of 10 μm or less (PM10) and meteorological observations are available from 13 stations distributed throughout Switzerland and representing different site types. The effect of all available meteorological variables on PM10 concentrations was estimated using Generalized Additive Models. Data from each season were treated separately. The most important variables affecting PM10 concentrations in winter, autumn and spring were wind gust, the precipitation rate of the previous day, the precipitation rate of the current day and the boundary layer depth. In summer, the most important variables were wind gust, Julian day and afternoon temperature. In addition, temperature was important in winter. A "weekend effect" was identified due to the selection of variable "day of the week" for some stations. Thursday contributes to an increase of 13% whereas Sunday contributes to a reduction of 12% of PM10 concentrations compared to Monday on average over 9 stations for the yearly data. The estimated effects of meteorological variables were removed from the measured PM10 values to obtain the PM10 variability and trends due to other factors and processes, mainly PM10 emissions and formation of secondary PM10 due to trace gas emissions. After applying this process, the PM10 variability was much lower, especially in winter where the ratio of adjusted over measured mean squared error was 0.27 on average over all considered sites. Moreover, PM10 trends in winter were more negative after the adjustment for meteorology and they ranged between −1.25 μg m−3 yr−1 and 0.07 μg m−3 yr−1. The adjusted trends for the other seasons ranged between −1.34 μg m−3 yr−1 and −0.26 μg m−3 yr−1 in spring, −1.40 μg m−3 yr−1 and −0.28 μg m−3 yr−1 in summer and −1.28 μg m−3 yr−1 and −0.11 μg m−3 yr−1 in autumn. The estimated trends of meteorologically adjusted PM10 were in general non-linear. The two urban street sites considered in the study, Bern and Lausanne, experienced the largest reduction in measured and adjusted PM10 concentrations. This indicates a verifiable effect of traffic emission reduction strategies implemented during the past two decades. The average adjusted yearly trends for rural, urban background and urban street stations were −0.37, −0.53 and −1.2 μg m−3 yr−1 respectively. The adjusted yearly trends for all stations range from −0.15 μg m−3 yr−1 to −1.2 μg m−3 yr−1 or −1.2% yr−1 to −3.3% yr−1.
Synergetic monitoring of Saharan dust plumes and potential impact on surface: a case study of dust transport from Canary Islands to Iberian Peninsula
Authors: Córdoba-Jabonero C. , Sorribas M. , Guerrero-Rascado J. L. , Adame J. A. , Hernández Y. , Lyamani H. , Cachorro V. , Gil M. , Alados-Arboledas L. , Cuevas E. , de la Morena B.
Published: November 2010

Abstract. Synergetic use of meteorological information, remote sensing both ground-based active (lidar) and passive (sun-photometry) techniques together with backtrajectory analysis and in situ measurements is carried out for the characterization of dust intrusions. A case study of air masses advected from Saharan region to the Canary Islands and the Iberian Peninsula, relatively located close and far away from the dust sources, respectively, was monitored from 11 to 19 March 2008. The observations were performed over three Spanish geographically strategic within the dust-influenced area stations along a common dust plume pathway. A 4-day long dust event (13–16 March) over the Santa Cruz de Tenerife Observatory (SCO), and a linked short 1-day dust episode (14 March) in the Southern Iberian Peninsula over both the Atmospheric Sounding Station "El Arenosillo" (ARN) and the Granada station (GRA) were detected. Meteorological situation favoured the dust plume transport over the area under study. Backtrajectory analysis clearly showed the Saharan origin of the dust intrusion. Under the Saharan air masses influence, AERONET Aerosol Optical Depth at 500 nm (AOD500) ranged from 0.3 to 0.6 and Angstrom Exponent at 440/675 nm wavelength pair (AE440/675) was lower than 0.5, indicating a high loading and predominance of coarse particles during those dusty events. Lidar observations characterized their vertical layering structure, identifying different aerosol contributions depending on altitude. In particular, the 3-km height layer observed over ARN and GRA stations corresponds to that dust plume transported from Saharan region after crossing through Canary Islands at 3 km height as observed over SCO site as well. No significant differences were found in the lidar (extinction-to-backscatter) ratio (LR) estimation for that dust plume over all stations when a suitable aerosol scenario for lidar data retrieval is selected. Lidar-retrieved LR values of 65–70 sr were obtained during the principal dusty episodes. These similar LR values found in all the stations suggest that dust properties were kept unchanged in the course of its medium-range transport. In addition, the potential impact on surface of that Saharan dust intrusion over the Iberian Peninsula was evaluated by ground-level in situ measurements for particle deposition assessment together with backtrajectory analysis. However, no connection between those dust plumes and the particle sedimentation registered at ground level is found. Differences on particle deposition process observed in both Southern Iberian Peninsula sites are due to the particular dust transport pattern occurred in each station.
Design and performance of a three-wavelength LED-based total scatter and backscatter integrating nephelometer
Authors: Müller T. , Laborde M. , Kassell G. , Wiedensohler A.
Published: November 2010

Abstract. Integrating nephelometers are instruments that directly measure a value close to the light scattering coefficient of airborne particles. Different models of nephelometers have been used for decades for monitoring and research applications. Now, a series of nephelometers (Ecotech models M9003, Aurora 1000 and Aurora 3000) with newly designed light sources based on light emitting diodes are available. This article reports on the design of these integrating nephelometers and a comparison of the Aurora 3000 to another commercial instrument (TSI model 3563) that uses an incandescent lamp. Both instruments are three-wavelength, total and backscatter integrating nephelometers. We present a characterization of the new light source design of the Aurora 3000 and provide parameterizations for its angular sensitivity functions. These parameterizations facilitate to correct for measurement artefacts using Mie-theory. Comparison measurements against the TSI 3563 with laboratory generated white particles and ambient air are shown and discussed. Both instruments agree well within the calibration uncertainties and detection limit for total scattering with differences less than 5%. Differences for backscattering are higher by up to 11%. Highest differences were found for the longest wavelengths, where the signal to noise ratio is lowest. Differences at the blue and green wavelengths are less than 4% and 3%, respectively, for both total and backscattering.
Sediment core fossils in ancient Lake Ohrid: testing for faunal change since the Last Interglacial
Authors: Albrecht C. , Vogel H. , Hauffe T. , Wilke T.
Published: November 2010

Abstract. Ancient Lake Ohrid is probably of early Pleistocene or Pliocene origin and amongst the few lakes in the world harbouring an outstanding degree of endemic biodiversity. Although there is a long history of evolutionary research in Lake Ohrid, particularly on molluscs, a mollusc fossil record has been missing up to date. For the first time, gastropod and bivalve fossils are reported from the basal, calcareous part of a 2.6 m long sediment succession (core Co1200) from the north-eastern part of Lake Ohrid. Electron spin resonance (ESR) dating of mollusc shells from the same stratigraphic level yielded an age of 130 ± 28 ka. Lithofacies III sediments, i.e. a stratigraphic subdivision comprising the basal succession of core Co1200 between 181.5–263 cm, appeared solid, greyish-white, and consisted almost entirely of silt-sized endogenic calcite (CaCO3>70%) and intact and broken mollusc shells. Here we compare the faunal composition of the thanatocoenosis with recent mollusc associations in Lake Ohrid. A total of 13 mollusc species (9 gastropod and 4 bivalve species) could be identified within Lithofacies III sediments. The value of sediment core fossils for reconstructing palaeoenvironmental settings was evaluated and the agreement between sediment and palaeontological proxies was tested. The study also aims at investigating major faunal changes since the Last Interglacial and searching for signs of extinction events. The combined findings of the ecological study and the sediment characteristics suggest deposition in a shallow water environment during the Last Interglacial. The fossil fauna exclusively included species also found in the present fauna, i.e. no extinction events are evident for this site since the Last Interglacial. The thanatocoenosis showed the highest similarity with recent Intermediate Layer (5–25 m water depth) mollusc assemblages. The demonstrated existence of a mollusc fossil record in Lake Ohrid sediment cores also has great significance for future deep drilling projects. It can be hoped that a more far reaching mollusc fossil record will then be obtained, enabling insight into the early evolutionary history of Lake Ohrid.
Nitrous oxide in the Changjiang (Yangtze River) Estuary and its adjacent marine area: Riverine input, sediment release and atmospheric fluxes
Authors: Zhang G.-L. , Zhang J. , Liu S.-M. , Ren J.-L. , Zhao Y.-C.
Published: November 2010

Abstract. Dissolved nitrous oxide (N2O) was measured in the waters of the Changjiang (Yangtze River) Estuary and its adjacent marine area during five surveys covering the period of 2002–2006. Dissolved N2O concentrations ranged from 6.04 to 21.3 nM, and indicate great temporal and spatial variations. Distribution of N2O in the Changjiang Estuary was influenced by multiple factors and the key factor varied between cruises. Dissolved riverine N2O was observed monthly at station Xuliujing of the Changjiang, and ranged from 12.4 to 33.3 nM with an average of 19.4 ± 7.3 nM. N2O concentrations in the river waters showed obvious seasonal variations with higher values occurring in both summer and winter. Annual input of N2O from the Changjiang to the estuary was estimated to be 15.0 × 106 mol/yr. N2O emission rates from the sediments of the Changjiang Estuary in spring ranged from −1.88 to 2.02 μmol m−2 d−1, which suggests that sediment can act as either a source or a sink of N2O in the Changjiang Estuary. Average annual sea-to-air N2O fluxes from the studied area were estimated to be 7.7 ± 5.5, 15.1 ± 10.8 and 17.0 ± 12.6 μmol m−2d−1 using LM86, W92 and RC01 relationships, respectively. Hence the Changjiang Estuary and its adjacent marine area are a net source of atmospheric N2O.
Linking plant ecophysiology to the dynamics of diverse communities
Authors: Bohn K. , Dyke J. G. , Pavlick R. , Reineking B. , Reu B. , Kleidon A.
Published: November 2010

Abstract. The local climate represents the primary selection pressure acting on vegetation, but competitive interactions between plant strategies determine their composition. We link growth and reproduction characteristics from different plant strategies, that emerge from climatic constraints, to their competitive abilities and calculate explicitly their spatial dynamics. DIVE (Dynamics and Interactions of VEgetation), a simple generic model is built, that calculates population dynamics in the presence of perturbations, seed and resource competition. To understand the impacts of competition and perturbations on the population dynamics, a range of sensitivity experiments are conducted. DIVE simulations feature successional dynamics from fast-growing towards slow-growing plant strategies and as such corresponds to widely observed characteristics of terrestrial vegetation. Perturbations, seed and resource competition were found to affect succession and diversity, with the community composition at steady state ranging from competitive exclusion to coexistence and total extinction. We conclude that linking ecophysiological characteristics of vegetation to competition is a valid approach to determine population dynamics. Furthermore, incorporating mechanisms of perturbations and competition may be essential in order to effectively predict the response of community dynamics to changing environmental conditions.
Robustness of the Atlantic-Pacific flow reversal in the early miocene
Authors: Bernsen E. , Dijkstra H. A.
Published: November 2010

Abstract. Based on modeling results and interpretations of observations, it has been suggested that during the early Miocene, a reversal of the Atlantic-Pacific ocean flow through the Panama Strait has occurred. During the Oligocene the net transport was westward, from the Atlantic into the Pacific, whereas in the Miocene the sign of this transport likely reversed to a net eastward transport into the Atlantic. With a global ocean model for the Oligocene and Miocene continental configurations we study the robustness of this flow reversal by carrying out a broad sensitivity analysis, including bottom topography, details of the continental geometry and surface forcing. This sensitivity study is efficiently done by using recent methodology to compute equilibrium solutions to the model. The Atlantic-Pacific flow reversal appears a very robust feature of the global ocean model.
Surface and subsurface flow effect on permanent gully formation and upland erosion near Lake Tana in the northern highlands of Ethiopia
Authors: Tebebu T. Y. , Abiy A. Z. , Zegeye A. D. , Dahlke H. E. , Easton Z. M. , Tilahun S. A. , Collick A. S. , Kidnau S. , Moges S. , Dadgari F. , Steenhuis T. S.
Published: November 2010

Abstract. Gully formation in the Ethiopian Highlands has been identified as a major source of sediment in water bodies, and results in sever land degradation. Loss of soil from gully erosion reduces agricultural productivity and grazing land availability, and is one of the major causes of reservoir siltation in the Nile Basin. This study was conducted in the 523 ha Debre-Mawi watershed south of Bahir Dar, Ethiopia, where gullies are actively forming in the landscape. Historic gully development in a section of the Debre-Mawi watershed was estimated with semi structured farmer interviews, remotely sensed imagery, and measurements of current gully volumes. Gully formation was assessed by instrumenting the gully and surrounding area to measure water table levels and soil physical properties. Gully formation began in the late 1980's following the removal of indigenous vegetation, leading to an increase in surface and subsurface runoff from the hillsides. A comparison of the gully area, estimated from a 0.58 m resolution QuickBird image, with the current gully area mapped with a GPS, indicated that the total eroded area of the gully increased from 0.65 ha in 2005 to 1.0 ha in 2007 and 1.43 ha in 2008. The gully erosion rate, calculated from cross-sectional transect measurements, between 2007 and 2008 was 530 t ha−1 yr−1 in the 17.4 ha area contributing to the gully, equivalent to over 4 cm soil loss over the contributing area. As a comparison, we also measured rill and interrill erosion rates in a nearby section of the watershed, gully erosion rates were approximately 20 times the measured rill and interrill rates. Depths to the water table measured with piezometers showed that in the actively eroding sections of the gully the water table was above the gully bottom and, in stable gully sections the water table was below the gully bottom during the rainy season. The elevated water table appears to facilitate the slumping of gully walls, which causes the gully to widen and to migrate up the hillside.
Formation of Cubic Zirconia by Reactive Arc Evaporation in a Mixture of Nitrogen‐Oxygen Reactive Gas
Authors: Neels A. , Vieira L. de Abreu , Döbeli M. , Dommann A. , Herrán J. , Neff F. , Widrig B. , Brändle H. , Ramm J.
Published: November 2010

Zr(N)O coatings being synthesized by cathodic arc evaporation (P3e™ technology) show that cubic zirconia, ZrO2, can be formed at low substrate temperatures of 550 °C using nitrogen‐oxygen reactive gas mixtures during deposition. The structural properties of the coatings obtained for different nitrogen‐oxygen ratios have been investigated by X‐Ray Diffraction (XRD) techniques. The composition of the layers was studied by RBS and ERDA and the layers morphology by cross sectional SEM. For low oxygen flows, the cubic ZrN and ZrO phase were formed while increased oxygen flow results in a transition starting from the orthorhombic to the cubic and to the monoclinic ZrO2 phase. The phase stability of the cubic ZrO2 phase has been investigated by in situ high temperatures XRD studies in air and reveals a multi step phase transformation starting at about 550 °C with a change to the tetragonal ZrO2 phase and the further transition to the monoclinic phase at higher temperatures.