bluuebunny/crossref_metadata_2025 huggingface dataset:
Experimental Investigation of the Viscous Effect on Two-Phase-Flow Patterns and Hydraulic Performance of Electrical Submersible Pumps
Authors: Trevisan Francisco E. , Prado Mauricio
Published: April 2011

Using a visualization prototype built from original electrical-submersible-pump (ESP) components and with minimal geometrical modifications, a pioneer experimental procedure was developed and conducted to address the viscous effect on liquid/gas two-phase flow through these types of pumps.

Based on dimensionless groups that govern centrifugal-pump single-phase performance, two-phase experiments were conducted at different shaft speeds (15, 25, and 30 Hz), with nonslip void fractions (up to 5%), and viscosity values of 46 to 161 cp, while liquid rates were kept constant at 60% of the maximum rate at the defined shaft speed. High-speed video footage was taken from the entire impeller flow channel, and stage incremental pressure was measured.

The authors identified four liquid/air flow patterns inside the impeller channels: agglomerated bubbles, gas pocket, segregated gas, and intermittent gas. By comparing the images with the differential-pressure data, it was concluded that the agglomerated-bubbles pattern is responsible for the initial head degradation and that the surging event coincides with the gas-pocket structure, indicating that this is an interface-instability problem. Another conclusion made was that the increase in viscosity caused surging to occur at lower void fractions, which could be compensated for by increasing rotational speed.

The significance of this work is given by the fact that several authors hae investigated centrifugal-pump performance under two-phase flow; however, previous experiments have been conducted only with water as the liquid, thus neglecting the viscous effect on the two-phase-flow mixture. In most of the petroleum industry's applications, ESPs operate with oil and natural gas. The present work begins the task of addressing this knowledge gap between scientific research and field applications.
Latest Technological Advances in Rod Pumping Allow Achieving Efficiencies Higher Than With ESP Systems
Authors: Takacs Gabor , Belhaj Hadi
Published: April 2011

Two of the most important artificial-lift methods applied in oil wells are sucker-rod pumping (SRP) and electrical submersible pumping (ESP, with thousands of installations all over the world. Their operational features and application ranges are quite different, but in many cases either of them can be used in a given well. The final selection of the proper method has to be on the basis of energy efficiency, and the one requiring the least amount of surface power input is selected. This paper provides the necessary background for evaluating the effectiveness of the two lift methods investigated and for pinpointing the requirements of achieving maximum power efficiency of artificial lifting.

The power flow in the pumping system is investigated, and the sources of power losses, along with their usual ranges, are described. The overall power efficiency of the system is defined by a simple formula that provides the necessary insight into the main components of the power losses occurring in different system elements. A thorough investigation of the efficiency components allows one to find the factors that most markedly influence the total system's power requirement. As shown in the paper, the most important requirement for achieving maximum effectiveness is the proper choice of the pumping mode (i.e., the combination of plunger size, stroke length, and pumping speed).

The calculation of energy losses in the components of the ESP system is detailed, and the relative importance of the individual losses is shown. Because the components of the ESP system are connected in series, a relatively simple formula can be used to describe the effect of electrical and hydraulic losses on the efficiency of the total system. The terms of the final formula were investigated for their importance and contribution to the overall effectiveness of the ESP system. Results of this investigation provide crucial information that explain how to design an ESP system that provides the highest power efficiency. The practical use of the proposed calculation models is illustrated by presenting an example case where a relatively high liquid rate (1,300 B/D) from the same well is produced by rod pumping and by ESP. Detailed installation designs resulted in several different operation modes for both SRP and ESP. The paper demonstrates that using the latest technologies (e.g., high-strength sucker-rod connections), SRP can compete successfully with ESP installations by attaining higher energy efficiencies.
Pump Intake Pressure Determined From Fluid Levels, Dynamometers, and Valve-Test Measurements
Authors: Rowlan O. Lynn , McCoy James N. , Podio Augusto L.
Published: April 2011

Three pump-intake-pressure (PIP) calculation methods available for wells artificially lifted with sucker rods are discussed in detail in this paper. The values of PIP obtained from acoustic fluid-level measurements in wells with moderate pump submergence can yield PIP estimates that agree with those of pump fluid-load analysis. If PIPs determined using these methods do not agree, then the operator must review the data quality and may reduce the deviation by adjusting certain parameters affecting the calculations. Field data for a significant group of wells are used to compare the PIP results of the three methods. The results show that the PIP computed using the maximum and minimum pump dynamometer loads usually calculates a PIP that is too low, while the PIPs computed using the valve test loads are usually too high. Recommendations are presented for quality control of the computed values.
MHD free convection and mass transfer flow over an infinite vertical porous plate with viscous dissipation
Authors: Poonia Hemant , Chaudhary R.C.
Published: April 2011

An unsteady, two-dimensional, hydromagnetic, laminar mixed convective
boundary layer flow of an incompressible and electrically-conducting fluid
along an infinite vertical plate embedded in the porous medium with heat and
mass transfer is analyzed, by taking into account the effect of viscous
dissipation. The dimensionless governing equations for this investigation
are solved analytically using two-term harmonic and non-harmonic functions.
Numerical evaluation of the analytical results is performed and graphical
results for velocity, temperature and concentration profiles within the
boundary layer are discussed. The results show that increased cooling (Gr >
0) of the plate and the Eckert number leads to a rise in the velocity
profile. Also, an increase in Eckert number leads to an increase in the
temperature. Effects of Sc on velocity and concentration are discussed and
shown graphically.
Study on the Development of Diltiazem HCl Loaded Colonic Drug Delivery Systems (CDDS) Using Various Polymers and Characterization of their Release Profiles by In Vitro Dissolution Studies
Authors: Islam Muhammad Sahidul , Chowdhury Jakir Ahmed , Tania Shirajum Monira
Published: April 2011

This investigation describes the preparation and in vitro evaluation of Colonic Drug Delivery of Diltiazem HCl tablet. Methocel K 4M premium, Methocel K 100M premium CR, Methocel K 15M CR and Xanthan gum were used for release controlling properties. For this purpose, tablets containing 90 mg of Diltiazem HCl along with different amounts of the aforementioned polymers were prepared using direct compression technique. All the formulations were then evaluated for thickness, hardness, diameter, weight variation and in vitro drug release characteristics as per USP monograph. Tablets prepared were placed in a basket type dissolution apparatus containing HCl solution (pH-1.2) for the first 2 hours and phosphate buffer (pH-7.4) for the next 6 hours of the study. The amount of drug released was determined at 237nm by a UV-visible spectrophotometer. Fitting of release data to different kinetic models showed that Methocel K 4M premium containing matrices conformed based to Korsmeyer release kinetics, Methocel K 100M CR based matrices to Korsmeyer and zero order, Methocel K 15M CR based matrices to zero order kinetics and Xanthan gum containing tablets to either of Higuchi and Korsmeyer release kinetics. The release exponent (n) derived from Korsmeyer-Peppas equation for the studied formulations implied that the release of Diltiazem HCl from Methocel K 4M premium based matrices and Methocel K 100M CR based formulations was Super case II transport mechanism. The value of release exponent (n) for Methocel K 15M CR containing matrices was mainly governed by Super case II transport. Xanthan gum based formulations was Anomalous/ Non-Fickian. Briefly, Methocel K 15M CR was found to be suitable for sustaining the release of Diltiazem HCl from matrix formulation inside the colon. Key words: Colonic Drug Delivery; Direct Compression; Methocel K 4M premium; Methocel K 100M CR; Methocel K 15M CR; Xanthan gum. DOI: 10.3329/dujps.v9i1.7424 Dhaka Univ. J. Pharm. Sci. 9(1): 7-13, 2010 (June)
Preparation and Evaluation of Cellulose Acetate Phthalate and Ethyl cellulose based Microcapsules of Diclofenac Sodium using Emulsification and Solvent-Evaporation Method
Authors: Rahman Md Mominur , Islam Md Saiful , Sharmin Nahid , Chowdhury Jakir Ahmed , Jalil Reza-ul
Published: April 2011

Diclofenac sodium (DS) microspheres were prepared with two different polymers, ethyl cellulose (EC) and cellulose acetate phthalate (CAP). Emulsification-solvent evaporation method was used to prepare the microspheres. Liquid paraffin containing 1.5% (w/w) span 80 was the external phase and acetone-polymer solution was the internal phase. EC and CAP, both as single and as mixture, were used to encapsulate DS. EC microspheres were more spherical in shape and showed more entrapment efficiency than CAP microspheres. The size of the microspheres varied between 560-920 μm and as high as 90% loading efficiency was obtained. In vitro release study was carried out in 0.1 N hydrochloric acid solution (pH 1.2) for first 2 hours followed by in phosphate buffer solution (pH 6.8) for next 4 hours. After first 2 hours of dissolution in 0.1 N hydrochloric acid, EC microspheres released 24% of DS whereas CAP microspheres released only 2% DS. After 4 hours of dissolution in phosphate buffer, 60% DS was released from EC microspheres and almost all drug was released from CAP microspheres. Combination of EC and CAP showed more sustaining action than the individual polymer in both the dissolution media. DS release from EC microspheres followed Higuchi model whereas CAP microspheres followed first order model. Key word: Diclofenac sodium; microsphere; Ethyl cellulose; Cellulose acetate pthalate DOI: 10.3329/dujps.v9i1.7428 Dhaka Univ. J. Pharm. Sci. 9(1): 39-46 2010 (June)
Studies of Biologically Active Heterocycles: Synthesis, Characterization and Antimicrobial Activity of Some 5-Substitutd-2-Amino-1,3,4-Oxadiazoles
Authors: Kumar Sanjeev
Published: April 2011

In the present study, 5-substituted-2-amino-1,3,4-oxadiazoles (4a-k) have been synthesized by the electrochemical oxidation of semicarbazones (3a-k) using platinum anode at room temperature under controlled potential electrolysis in an undivided cell assembly. The structural assignment of these compounds (4a-k) has been made on the basis of elemental analysis, IR, 1H NMR and 13C NMR. The synthesized compounds were screened for their inhibiting activity against Klebsilla penumoniae, Escherichia coli, Bassilus subtilis and Streptococcus aureus and antifungal activity against Aspergillus niger and Crysosporium pannical and results have been compared with the standard antibacterial agents, Streptomycin and antifungal drug, Griseofulvin. The Compounds exhibited significant antibacterial activity and antifungal activity. Key words: Electrochemical oxidation; controlled potential; 5-substituted-2-amino-1,3,4-oxadiazole; semicarbazone; antimicrobial agents DOI: 10.3329/dujps.v9i1.7434 Dhaka Univ. J. Pharm. Sci. 9(1): 53-59 2010 (June)
Components and Insecticidal Activity against the Maize Weevils of Zanthoxylum schinifolium Fruits and Leaves
Authors: Wang Cheng Fang , Yang Kai , Zhang Hai Ming , Cao Jie , Fang Rui , Liu Zhi Long , Du Shu Shan , Wang Yong Yan , Deng Zhi Wei , Zhou Ligang
Published: April 2011

In our screening program for new agrochemicals from Chinese medicinal herbs and wild plants, Zanthoxylum schinifolium essential oils were found to possess strong insecticidal activity against the maize weevil Sitophilus zeamais. The essential oils of Z. schinifolium fruits and leaves were extracted via hydrodistillation and investigated by GC and GC-MS. Estragole (69.52%) was the major compound of the essential oil of fresh fruits, followed by linalool (8.63%) and limonene (4.34%) and 94.33% of the total components were monoterpenoids. The main components of the essential oil of fresh leaves were linalool (12.94%), ar-tumerone (8.95%), limonene (6.45%) and elixene (5.43%) and only 50.62% were monoterpenoids. However, the essential oil from purchased fruits contained linalool (33.42%), limonene (13.66%) and sabinene (5.72%), followed by estragole (4.67%), nerol (4.56%) and 4-terpineol (4.27%). Estragole, linalool and sabinene were separated and purified by silica gel column chromatography and preparative thin layer chromatography, and further identified by means of physicochemical and spectrometric analysis. The essential oil from the fresh fruits (LD50 = 15.93 μg/adult) possessed two times more toxicity to the insects compared with that of fresh leaves (LD50 = 35.31 μg/adult). Estragole, linalool and sabinene exhibited contact activity against S. zeamais with LD50 values of 17.63, 13.90 and 23.98 μg/adult, respectively. The essential oils of Z. schinifolium possessed strong fumigant toxicity against S. zeamais adults with LC50 values of 13.19 mg/L (fresh fruits), 24.04 mg/L (fresh leaves) and 17.63 mg/L (purchased fruits). Estragole, linalool and sabinene also exhibited strong fumigant toxicity against the maize weevils with LC50 values of 14.10, 10.46 and 9.12 mg/L, respectively.
Lancifoliaine, a New Bisbenzylisoquinoline from the Bark of Litsea lancifolia
Authors: Sulaiman Syazreen Nadia , Mukhtar Mat Ropi , Hadi A Hamid A , Awang Khalijah , Hazni Hazrina , Zahari Azeana , Litaudon Marc , Zaima Kazumasa , Morita Hiroshi
Published: April 2011

A new bisbenzylisoquinoline, lancifoliaine (1), together with seven known alkaloids – N-allyllaurolitsine (2), reticuline (3), actinodaphnine, norboldine, pallidine, cassythicine and boldine – were isolated from the stem bark of Litsea lancifolia (Lauraceae). In addition to that of lancifoliaine, complete 13C-NMR data of N-allyl-laurolitsine (2) was also reported. The alkaloidal structures were elucidated by means of high field 1D- and 2D-NMR IR, UV, and LCMS-IT-TOF spectral data. N-Allyllaurolitsine (2) showed a moderate vasorelaxant activity on isolated rat aorta.
Meaning and Practice of Palliative Care for Hospitalized Older Adults with Life Limiting Illnesses
Authors: Powers Bethel Ann , Norton Sally A. , Schmitt Madeline H. , Quill Timothy E. , Metzger Maureen
Published: April 2011

Objective. To illustrate distinctions and intersections of palliative care (PC) and end-of-life (EOL) services through examples from case-centered data of older adults cared for during a four-year ethnographic study of an acute care hospital palliative care consultation service.Methods. Qualitative narrative and thematic analysis.Results. Description of four practice paradigms (EOL transitions, prognostic uncertainty, discharge planning, and patient/family values and preferences) and identification of the underlying structure and communication patterns of PC consultation services common to them.Conclusions. Consistent with reports by other researchers, study data support the need to move beyond equating PC with hospice or EOL care and the notion that EOL is a well-demarcated period of time before death. If professional health care providers assume that PC services are limited to assisting with and helping patients and families prepare for dying, they miss opportunities to provide care considered important to older individuals confronting life-limiting illnesses.
Surveillance of Aflatoxin and Microbiota Related to Brewer's Grain Destined for Swine Feed in Argentina
Authors: Gerbaldo Gisela A. , Pereyra Carina M. , Cavaglieri Lilia R. , Ruiz Francisco , Pascual Liliana , Dalcero Ana M. , Barberis Isabel L.
Published: April 2011

Córdoba province in the center of Argentina is an important area of swine production. The use of industry by-product (brewer's grain) as feedstuff for swine is a regular practice and increases animal performance on these animals production. The occurrence of aflatoxin contamination is global, causing severe problems especially in developing countries. No reports on aflatoxin B1production, micoflora, and potential aflatoxin B1producing microorganism from brewer's grain are available. The aims of this study were (1) to isolate the microbiota species from brewer's grain, (2) to determine aflatoxin B1natural contamination levels, and (3) to determine the ability ofAspergillussectionFlaviisolates to produce aflatoxinsin vitro. Physical properties, total fungal counts, lactic acid bacteria, and fungal genera distribution were determined on this substrate. In 65% of the samples, fungal counts were higher than recommended by GMP, and lactic bacterium counts ranged from1.9×105to4.4×109 CFUg−1.Aspergillusspp. prevailed over other fungal genera.Aspergillus flavuswas the prevalent species followed byA. fumigatus. Aflatoxin B1levels in the samples were higher than the recommended limits (20 ng g−1) for complementary feedstuffs. SeveralAspergillussectionFlavistrains were able to produce aflatoxin B1  in vitro. Inadequate storage conditions promote the proliferation of mycotoxin-producing fungal species. Regular monitoring of feeds is required in order to prevent chronic and acute toxic syndromes related to this kind of contamination.
Is Tayside becoming a Scottish hotspot for Lyme borreliosis?
Authors: Slack GS , Mavin S , Yirrell D , Ho-Yen DO
Published: April 2011

The epidemiology of Lyme borreliosis (LB) in Tayside was studied and compared with Highland (an area of high endemicity) and the rest of Scotland. From April 2001 to March 2008 the incidence of LB in Tayside rose from an estimated 2.57 to 5.84 per 100,000 population. In 2008/09 the incidence of LB in Tayside increased further to an estimated 13.85 per 100,000 population. This rise was significant and, although numerically less than that in Highland (37.24 to 49.69 per 100,000 population), it was proportionally much larger (137% vs 33%) and confirmed that LB in Tayside has diverged from that in non-endemic Scottish regions. The dramatic rise of LB in Tayside cannot be accounted for by changes in laboratory protocol or changes in the number or demographics of patients tested. However, changes in climatic conditions and alterations in clinical presentations may have contributed to this significant rise.
Presentations of pyogenic liver abscess in one UK centre over a 15-year period
Authors: Bosanko NC , Chauhan A , Brookes M , Moss M , Wilson PG
Published: April 2011

Background and aim: Pyogenic liver abscess (PLA) has been a condition of high mortality, improving over recent decades with combined antibiotic and percutaneous drainage. We aimed to identify the presenting features, diagnosis, microbiology, treatment and outcome for patients over a 15-year period at an inner-city hospital.

Methods: Patients with an appropriate discharge diagnosis were identified and case records retrospectively analysed.

Results: A total of 73 patient records were analysed. Common presenting features were anorexia, abdominal pain, fever, vomiting and weight loss with raised white cell count, C-reactive protein, alkaline phosphatase and hypoalbuminaemia. The delay following symptom onset to presentation was a mean of 17.3 days. The inclusion of PLA as a possible diagnosis on admission was only considered in 1% of cases. Positive blood or abscess culture was achieved in 63% of cases. We recorded a hospital mortality rate of 11%.

Conclusions: In this sample, PLA was rarely considered as a possible diagnosis at presentation. There are common presenting features, which should prompt early investigation. Our microbiological yield was lower than in some studies and may be due to the early empirical use of antibiotics, without microbiological guidance. Percutaneous drainage and antibiotic treatment remain the mainstay of management. The underlying cause for PLA is often not identified. Emerging septicaemia or underlying malignancy were strong predictors of mortality.
‘No DVT found’ is not a diagnosis: look beyond the D-dimer
Authors: Jamieson A
Published: April 2011

Current clinical practice is often heavily biased towards the exclusion of potentially serious, treatable diagnoses, such as deep venous thrombosis, rather than the positive diagnosis of the patient’s underlying illness which precipitates seeking medical attention. We report a case of leg swelling where deep venous thrombosis was repeatedly excluded as a cause of leg pain and swelling, but where arrival at the correct diagnosis was significantly delayed, in part due to protocol-driven practice.
Cytological recognition of herpes simplex virus infection in bronchoscopic samples from the respiratory tract
Authors: Wilkinson I , Cuschieri KS , Monaghan H , Salter DM , Wallace WA
Published: April 2011

Cytological features suggesting herpes simplex virus (HSV) infection in samples obtained at bronchoscopy have been described only very rarely in routinely processed samples. We report four cases where evidence of HSV infection was identified morphologically in samples processed using thin-layer techniques, with polymerase chain reaction confirmation of the presence of virus in three cases. We suggest that the increased morphological clarity provided by this technique for processing these cytology samples may result in the morphological features of viral infection being seen more frequently. Pathologists reporting such samples need to be aware of this possibility in order to avoid potential misinterpretations. In addition, however, respiratory and intensive care physicians unused to receiving cytology reports indicating ‘HSV infection’ need to be aware that the significance is uncertain and in most cases it is likely to indicate the reactivation of a latent infection.
Do we need more long-term outcome trials for the treatment of hypertension?
Authors: Beevers DG , McInnes GT
Published: April 2011

The epidemiology of arterial hypertension and its treatment has been underlined by a huge research literature. Consistently raised arterial blood pressure in a clinic or home setting is a simple clinical observation that marks a predilection to a variety of fatal and non-fatal vascular disease events. Over the past 50 years tolerable, safe and effective primary and secondary medicines to offset a substantial amount of the associated morbidity and mortality risk of elevated blood pressure have emerged. Due to the nature of the population-relative risk and low absolute risk of this phenomenon it has often taken very large numbers of patients recruited from multiple centres in several countries and huge financial investment to define these profiles. Few national clinical research funds have invested in this process and it has often been left to a relatively small group of investigators to work closely with the commercial producers of new medicines to complete the essential outcome trials on which much of contemporary cardiovascular medical practice is based. Currently there are few, if any, significant new drug entities relevant to raised blood pressure under development. Most of the underlying clinical management principles and associations are clear. Achieved blood pressure, through patient adherence and variable prescriber practice, defines outcomes for individuals. The theoretical likelihood of a major step forward in the understanding of raised arterial blood pressure or a preferred means for population management is low. Moreover, with few new drug entities, investment in major outcome trials is unlikely to be proposed and the target for new trials is perhaps less apparent. While there can be no doubt that few areas in recent medical practice have benefited more from such huge achievements in underlining treatment, is it time to move on from the cardiovascular mega trial in hypertension? In this controversy we have asked two international authorities in blood pressure care to address the case for and against further mega trials in this area of practice.
Functional neurological symptoms
Authors: Stone J
Published: April 2011

Functional neurological symptoms refer to neurological symptoms that are not explained by disease. They may also be called psychogenic, nonorganic, somatoform, dissociative or conversion symptoms. The most common functional neurological symptoms are non-epileptic attacks and functional weakness. These are common in neurology and general medical practice, especially in emergency situations, where they can be mistaken for epilepsy or stroke. Many studies have shown that these symptoms often persist, are associated with distress and disability and, in the right hands, have a low rate of misdiagnosis. Physicians are often uncertain how to approach patients with these problems. Are patients making up the symptoms? How can the diagnosis be made confidently? What is the best way to explain the diagnosis to the patient? Does treatment ever help? This review takes readers through these questions with practical tips for avoiding common pitfalls, both in diagnosis and management. There is no good evidence that these symptoms are any more ‘made up’ than irritable bowel symptoms or chronic pain. The diagnosis should usually be made by a neurologist on the basis of positive signs of inconsistency such as Hoover’s sign or the typical features of a non-epileptic attack. A ‘functional’ model of the symptoms is useful both in thinking about the problem and when explaining the symptoms to the patient. There are many useful steps in management that do not require a detailed understanding of aetiology in an individual patient.
Recent advances in the management of viral hepatitis
Authors: Holt A
Published: April 2011

While viral hepatitis is a global problem its prevalence in the UK is often underestimated. Chronic infection with the hepatitis B and/or C virus causes significant morbidity and mortality. New treatments that attenuate viral replication or induce immunity against infection have transformed the management of these conditions, but their effectiveness comes at some cost – both in financial terms and in the side-effect profile associated with treatment. Viral resistance promises to be an ongoing problem, particularly in patients who have an inadequate response to antiviral therapy or are non-adherent with treatment protocols. This article explores new developments in the treatment of chronic hepatitis B and C infection, and describes current protocols for managing patients with these conditions.
Hong Kong’s first Professor of Pathology and the laboratory of the Royal College of Physicians of Edinburgh
Authors: Ho FCS
Published: April 2011

At a time when the role of the laboratory in clinical medicine and in medical research was evolving rapidly, a young Chinese graduate of the Hong Kong College of Medicine and the University of Edinburgh undertook a period of intensive training at the laboratory of the Royal College of Physicians of Edinburgh that was to play a pivotal role in determining his future career as the first Professor of Pathology at the University of Hong Kong and its first professor of Chinese descent. Chung Yik Wang’s subsequent achievements over a span of ten years were a testament to the solid foundation that had been laid during that early period, and was an excellent example of how the skills of medical science could be transferred across continents to best effect. Tragically, Wang’s career was cut short when he succumbed to tuberculosis, the disease he had spent many years studying.
The lack of a child, the loss of a throne: the infertility of the first royal couple of Greece (1833–62)
Authors: Poulakou-Rebelakou E , Tsiamis C , Tompros N , Creatsas G
Published: April 2011

The first dynasty in Greece after its independence in 1830 was founded in 1833 with Otto, the son of Ludwig I of Bavaria. In 1836 Otto married Amalia, the daughter of the Grand Duke of Oldenburg. The people of Greece anticipated that the marriage would result in an heir to the throne, establishing the new dynasty. The failure of the royal couple to produce an heir was a major reason for their subsequent abdication. For many years both were subjected to repeated examinations by Greek and German physicians, especially Amalia, who was considered to be largely responsible for the infertility. In this paper we discuss possible diagnoses and describe the various treatments suggested for, and applied to, the infertility. We also review the consequent political controversies and the problems created among the royal families of Europe who wanted to replace the Wittelsbach dynasty with another royal line – a situation that led, in 1863, to the succession of the Danish Schleswig-Holstein-Sonderburg-Glücksburg dynasty to the Greek throne.
The history of Ephedra (ma-huang)
Authors: Lee MR
Published: April 2011

Ephedra is a Chinese shrub which has been used in China for medicinal purposes for several thousand years. The pure alkaloid ephedrine was first isolated and characterised by Nagai in 1885. It was then forgotten until it was rediscovered by Chen and Schmidt in the early 1920s. Its actions on the adrenoceptors could be classified into separate alpha and beta effects – a defining moment in the history of autonomic pharmacology. Ephedrine became a highly popular and effective treatment for asthma, particularly because, unlike adrenaline (until then the standard therapy), it can be given by mouth. Ephedrine as a treatment for asthma reached its zenith in the late 1950s, since when there has been a gradual and inevitable decline in its therapeutic use. From mainstream medicine, ephedrine moved into the twilight zone of street drugs and nutritional supplements. Ephedra and ephedrine products are now banned in many countries, as they are a major source for the production of the addictive compound methamphetamine (crystal meth).
Vascular cognitive impairment: epidemiology, subtypes, diagnosis and management
Authors: Black SE
Published: April 2011

Dementia occurs after stroke in 25% of patients but also can arise from covert cerebrovascular disease (CVD). ‘Silent’ lacunes occur in 25% of the elderly, often associated with focal or confluent hyperintensities on T2-weighted magnetic resonance imaging, which are detected in 95% of seniors. These covert infarcts predict future stroke and faster cognitive decline. Best practice guidelines advocate screening for cognitive impairment in all phases of overt stroke, when covert CVD is uncovered, when vascular risk factors are present and if patients present with cognitive complaints. Standardised testing is recommended, emphasising executive function and speed of processing. Cholinesterase inhibitors have cognitive enhancing effects in vascular dementia, but the major thrust is still aggressive management of vascular risk factors and healthy lifestyle choices. Given that mixed Alzheimer’s dementia and CVD is likely the most common substrate for dementia and that they share common vascular risk factors, a major goal for vascular medicine is cerebrovascular protection, not just to prevent heart attack and stroke, but also to maintain brain health and delay dementia.
A new estimation of the recent tropospheric molecular hydrogen budget using atmospheric observations and variational inversion
Authors: Yver C. E. , Pison I. C. , Fortems-Cheiney A. , Schmidt M. , Chevallier F. , Ramonet M. , Jordan A. , Søvde O. A. , Engel A. , Fisher R. E. , Lowry D. , Nisbet E. G. , Levin I. , Hammer S. , Necki J. , Bartyzel J. , Reimann S. , Vollmer M. K. , Steinbacher M. , Aalto T. , Maione M. , Arduini J. , O'Doherty S. , Grant A. , Sturges W. T. , Forster G. L. , Lunder C. R. , Privalov V. , Paramonova N. , Werner A. , Bousquet P.
Published: April 2011

Abstract. This paper presents an analysis of the recent tropospheric molecular hydrogen (H2) budget with a particular focus on soil uptake and European surface emissions. A variational inversion scheme is combined with observations from the RAMCES and EUROHYDROS atmospheric networks, which include continuous measurements performed between mid-2006 and mid-2009. Net H2 surface flux, then deposition velocity and surface emissions and finally, deposition velocity, biomass burning, anthropogenic and N2 fixation-related emissions were simultaneously inverted in several scenarios. These scenarios have focused on the sensibility of the soil uptake value to different spatio-temporal distributions. The range of variations of these diverse inversion sets generate an estimate of the uncertainty for each term of the H2 budget. The net H2 flux per region (High Northern Hemisphere, Tropics and High Southern Hemisphere) varies between −8 and +8 Tg yr−1. The best inversion in terms of fit to the observations combines updated prior surface emissions and a soil deposition velocity map that is based on bottom-up and top-down estimations. Our estimate of global H2 soil uptake is −59±9 Tg yr−1. Forty per cent of this uptake is located in the High Northern Hemisphere and 55% is located in the Tropics. In terms of surface emissions, seasonality is mainly driven by biomass burning emissions. The inferred European anthropogenic emissions are consistent with independent H2 emissions estimated using a H2/CO mass ratio of 0.034 and CO emissions within the range of their respective uncertainties. Additional constraints, such as isotopic measurements would be needed to infer a more robust partition of H2 sources and sinks.
Using boundary layer equilibrium to reduce uncertainties in transport models and CO2 flux inversions
Authors: Williams I. N. , Riley W. J. , Torn M. S. , Berry J. A. , Biraud S. C.
Published: April 2011

Abstract. This paper reexamines evidence for previously hypothesized errors in atmospheric transport models and CO2 flux inversions by evaluating the diagnostics used to infer vertical mixing rates from observations. Several conventional mixing diagnostics are compared to analyzed mixing using data from the US Southern Great Plains Atmospheric Radiation Measurement Climate Research Facility, the CarbonTracker data assimilation system based on Transport Model version 5 (TM5), and atmospheric reanalyses. The results demonstrate that previous diagnostics based on boundary layer depth and vertical concentration gradients are unreliable indicators of vertical mixing. Vertical mixing rates are anti-correlated with boundary layer depth at some sites, diminishing in summer when the boundary layer is deepest. Vertical CO2 gradients between the boundary layer and free-troposphere are strongly affected by seasonal surface fluxes and therefore do not accurately reflect vertical mixing rates. The finite timescale over which vertical tracer gradients relax toward equilibrium is proposed as an improved mixing diagnostic, which can be applied to observations and model simulations of CO2 or other conserved boundary layer tracers with surface sources and sinks. This diagnostic does not require dynamical variables from the transport models, and is independent of possible systematic biases in prior- and post-inversion seasonal surface fluxes. Results indicate that observations frequently cited as evidence for systematic biases in atmospheric transport models are insufficient to prove that such biases exist. Some previously hypothesized transport model biases, if found and corrected, could cause inverse estimates to further diverge from land-based estimates.
Aircraft study of the impact of lake-breeze circulations on trace gases and particles during BAQS-Met 2007
Authors: Hayden K. L. , Sills D. M. L. , Brook J. R. , Li S.-M. , Makar P. A. , Markovic M. Z. , Liu P. , Anlauf K. G. , O'Brien J. M. , Li Q. , McLaren R.
Published: April 2011

Abstract. High time-resolved aircraft data, concurrent surface measurements and air quality model simulations were explored to diagnose the processes influencing aerosol chemistry under the influence of lake-breeze circulations in a polluted region of southwestern Ontario, Canada. The analysis was based upon horizontal aircraft transects at multiple altitudes across an entire lake-breeze circulation. Air mass boundaries due to lake-breeze fronts were identified in the aircraft meteorological and chemical data, which were consistent with the frontal locations determined from surface analyses. Observations and modelling support the interpretation of a lake-breeze circulation where pollutants were lofted at a lake-breeze front, transported in the synoptic flow, caught in a downdraft over the lake, and then confined by onshore flow. The detailed analysis led to the development of conceptual models that summarize the complex 3-D circulation patterns and their interaction with the synoptic flow. The identified air mass boundaries, the interpretation of the lake-breeze circulation, and best estimates for air parcel circulation times in the lake-breeze circulation (1.2 to 3.0 h) enabled formation rates of oxygenated organic aerosol (OOA/ΔCO) and SO42− to be determined. The formation rate for OOA, relative to excess CO, was found to be 2.5–6.2 μg m−3 ppmv−1 h−1 and the SO42− formation rate was 1.8–4.6% h−1. The formation rates are enhanced relative to regional background rates implying that lake-breeze circulations are an important dynamic in the formation of SO42− and secondary organic aerosol. The presence of cumulus clouds associated with the lake-breeze fronts suggests that these enhancements could be due to cloud processes. Additionally, the effective confinement of pollutants along the shoreline may have limited pollutant dilution leading to elevated oxidant concentrations.
Spectral dependence of aerosol light absorption over the Amazon Basin
Authors: Rizzo L. V. , Correia A. L. , Artaxo P. , Procópio A. S. , Andreae M. O.
Published: April 2011

Abstract. In this study, we examine the spectral dependence of aerosol absorption at different sites and seasons in the Amazon Basin. The analysis is based on measurements performed during three intensive field experiments at a pasture site (Fazenda Nossa Senhora, Rondônia) and at a primary forest site (Cuieiras Reserve, Amazonas), from 1999 to 2004. Aerosol absorption spectra were measured using two Aethalometers: a 7-wavelength Aethalometer (AE30) that covers the visible (VIS) to near-infrared (NIR) spectral range, and a 2-wavelength Aethalometer (AE20) that measures absorption in the UV and in the visible. As a consequence of biomass burning emissions, about 10 times greater absorption values were observed in the dry season in comparison to the wet season. Power law expressions were fitted to the measurements in order to derive the Ångström exponent for absorption, defined as the negative slope of absorption vs. wavelength in a log-log plot. At the pasture site, about 70% of the Ångström exponents fell between 1.5 and 2.5 during the dry season, indicating that biomass burning aerosols have a stronger spectral dependence than soot carbon particles. Ångström exponents decreased from the dry to the wet season, in agreement with the shift from biomass burning aerosols, predominant in the fine mode, to biogenic and dust aerosols, predominant in the coarse mode. The lowest Ångström exponents (90% of data below 1.5) were observed at the forest site during the dry season. Also, results indicate that low absorption coefficients were associated with Ångström exponents below 1.0. This finding suggests that biogenic aerosols from Amazonia may have a weak spectral dependence for absorption, contradicting our expectations of biogenic particles behaving as brown carbon. Nevertheless, additional measurements should be taken in the future, to provide a complete picture of biogenic aerosol absorption spectral characteristics from different seasons and geographic locations. The assumption that soot spectral properties represent all ambient light absorbing particles may cause a misjudgment of absorption towards the UV, especially in remote areas. Therefore, it is recommended to measure aerosol absorption at several wavelengths from UV to near IR to accurately assess the impact of non-soot aerosols on climate and on photochemical atmospheric processes.
Fluvial organic carbon losses from a Bornean blackwater river
Authors: Moore S. , Gauci V. , Evans C. D. , Page S. E.
Published: April 2011

Abstract. Concentrations of dissolved organic carbon (DOC) and particulate organic carbon (POC) were analysed from the source to the mouth of the River Sebangau in Central Kalimantan, Indonesia during the dry and wet seasons in 2008/2009 and an annual total organic carbon (TOC) flux estimated. DOC concentrations were higher and POC concentrations lower in the wet season compared to the dry season. As seen in other tropical blackwater rivers, DOC concentration is consistently around 10 times greater than POC concentration. We estimate the annual TOC flux discharged to the Java Sea to be 0.46 Tg year−1 comprising of 93% (0.43 Tg) DOC and 7% (0.03 Tg) POC. This equates to a fluvial TOC loss flux per unit area over the entire Sebangau catchment of 88 g C m−2 yr−1. When extrapolating the River Sebangau DOC loss flux (83 g C m−2 yr−1) to the peat covered area of Indonesia (206 950 km2), we estimate a DOC loss of 17.2 Tg C yr−1 or ~10% of current estimates of the global annual riverine DOC discharge into the ocean.
Analysis of projected hydrological behavior of catchments based on signature indices
Authors: Casper M. C. , Grigoryan G. , Gronz O. , Gutjahr O. , Heinemann G. , Ley R. , Rock A.
Published: April 2011

Abstract. To precisely map the changes in hydrologic response of catchments (e.g., water balance, reactivity or extremes) we need sensitive and interpretable indicators. In this study we defined nine hydrologically meaningful signature indices: five indices were sampled on the flow duration curve, four indices were closely linked to the distribution of event runoff coefficients. We applied these signature indices to the output from three hydrologic catchment models located in the Nahe basin (Western Germany) to detect differences in runoff behavior resulting from different meteorological input data. The models were driven by measured and simulated (COSMO-CLM) meteorological data. It could be shown that application of signature indices is a very sensitive tool to assess differences in simulated runoff behavior resulting from climatic data sets of different sources. The hydrological model acts as a filter for the meteorological input and is therefore very sensitive to biases in mean and spatio-temporal distribution of precipitation and temperature. The selected signature indices allow assessing changes in water balance, vertical water distribution, reactivity, seasonality and runoff generation. Bias correction of temperature fields and adjustment of bias correction of precipitation fields seemed to be indispensable. For this reason, future work will focus on improving bias correction for CCLM data sets. Signature indices may then act as indirect "efficiency measures" or "similarity measures" for the reference period of the simulation.
Imaging the structure of cave ice by ground-penetrating radar
Authors: Hausmann H. , Behm M.
Published: April 2011

Abstract. Several caves in high elevated alpine regions host up to several meters thick ice. The age of the ice may exceed some hundreds or thousands of years. However, structure, formation and development of the ice are not fully understood and are subject to relatively recent investigation. The application of ground-penetrating radar (GPR) enables to determine thickness, volume, basal and internal structure of the ice and provides as such important constraints for related studies. We present results from four caves located in the Northern Calcareous Alps of Austria. We show that the ice is far from being uniform. The base has variable reflection signatures, which is related to the type and size of underlying debris. The internal structure of the cave ice is characterized by banded reflections. These reflection signatures are interpreted as thin layers of sediments and might help to understand the ice formation by representing isochrones. Overall, the relatively low electromagnetic wave speed suggests that the ice is temperate, and that a liquid water content of about 2% is distributed homogenously in the ice.
Phylogenetic Evidence for the Gain and Loss of a Sexually Selected Trait in Sailfin Mollies
Authors: Ptacek Margaret B. , Childress Michael J. , Petersen Jennifer A. , Tomasso Anne O.
Published: April 2011

A phylogenetic comparative approach was used to examine the evolution of the enlarged “sailfin,” characteristic of the monophyletic lineage of sailfin mollies (Poecilia:Mollienesia), but absent in one of its species,P.latipunctata. Ancestral character state reconstructions demonstrated that the ancestral sailfin molly possessed the enlarged sailfin, and, thus, males ofP.latipunctatahave secondarily lost this trait. The strength of female mating preference was measured inP.latipunctatafor two known targets of sexual selection, large male size, and sailfin male phenotype. Females ofP.latipunctatapreferred conspecific males of larger body size to those of smaller body size, but showed no preference for sailfin males of a related species,P.velifera, when compared with males of the shortfin species,P.mexicana. Taken together, these results suggest that the targets of sexual selection may have shifted in this species and that reduction in female preference for sailfin males may have played a role in the loss of this ornament.
Perceived Changes in Communicative Interaction in Atypical Parkinsonism
Authors: Hartelius Lena , Lindberg Johan , Petersson Lena , Saldert Charlotta
Published: April 2011

The aim of this study was to examine if atypical parkinsonism affects the communicative ability in conversational interaction. Fifteen persons close to individuals with atypical parkinsonism answered a questionnaire, “Assessment of Change in Communicative Interaction” (ACCI), estimating perceived change in interactive skills compared to before the onset of the disease. The study also examined if perceived change correlated with disease duration. The results showed that at group level, the participants experienced change in many aspects of conversational interaction, particularly regarding the affected person's speech, body communication, response latency, phrase length, word finding, and ability to make themselves understood. There was no correlation between perceived change and disease duration. In conclusion, results indicated that the communicative interaction of individuals with atypical parkinsonism is significantly affected and that information elicited from significant others can help define specific problem areas or foci of concern that need to be targeted in communicative intervention or at least considered in interaction with these persons.
What Psychologists Know and Believe about Memory: A Survey of Practitioners
Authors: Magnussen Svein , Melinder Annika
Published: April 2011

We surveyed 858 licensed psychologists, members of the Norwegian Psychological Association, about their knowledge and beliefs about human memory. The results were compared to the results of parallel surveys of legal professionals and lay persons, and evaluated in the light of the results of current memory science. The results indicate that psychologists are not memory experts qua psychologists; as a group, psychologists do not score above the level of knowledge of lay persons or trial judges on issues of eyewitness memory, and a substantial minority of the sample of respondents harbours scientifically unproven ideas of memory. The implications of these findings for psychological practice, with special reference to the court room, are briefly discussed. Copyright © 2011 John Wiley & Sons, Ltd.