bluuebunny/crossref_metadata_2025 huggingface dataset:
A critical humidity threshold for monsoon transitions
Authors: Schewe J. , Levermann A. , Cheng H.
Published: May 2011

Abstract. Monsoon systems around the world are governed by the so-called moisture-advection feedback. Here we show that, in a minimal conceptual model, this feedback implies a critical threshold with respect to the atmospheric specific humidity qo over the ocean adjacent to the monsoon region. If qo falls short of this critical value qoc, monsoon rainfall over land cannot be sustained. Such a case could occur if evaporation from the ocean was reduced, e.g. due to low sea surface temperatures. Within the restrictions of the conceptual model, we estimate qoc from present-day reanalysis data for four major monsoon systems, and demonstrate how this concept can help understand abrupt variations in monsoon strength on orbital timescales as found in proxy records.
Glacial CO2 cycle as a succession of key physical and biogeochemical processes
Authors: Brovkin V. , Ganopolski A. , Archer D. , Munhoven G.
Published: May 2011

Abstract. During glacial-interglacial cycles, atmospheric CO2 concentration varied by about 100 ppmv in amplitude. While testing mechanisms that had led to the low glacial CO2 level could be done in equilibrium model experiments, an ultimate goal is to explain CO2 changes in transient simulations through the complete glacial-interglacial cycle. A computationally efficient Earth System model of intermediate complexity CLIMBER-2 is used to simulate global biogeochemistry over the last glacial cycle (126 kyr). The physical core of the model (atmosphere, ocean, land and ice sheets) is driven by orbital changes and reconstructed radiative forcing from greenhouses gases, ice, and aeolian dust. The carbon cycle model is able to reproduce the main features of the CO2 changes: a 50 ppmv CO2 drop during glacial inception, a minimum concentration at the last glacial maximum by 80 ppmv lower than the Holocene value, and an abrupt 60 ppmv CO2 rise during the deglaciation. The model deep ocean δ13C also resembles reconstructions from deep-sea cores. The main drivers of atmospheric CO2 evolve with time: changes in sea surface temperatures and in the volume of bottom water of southern origin controls atmospheric CO2 during the glacial inception and deglaciation, while changes in carbonate chemistry and marine biology are dominant during the first and second parts of the glacial cycle, respectively. These feedback mechanisms could also significantly impact the ultimate climate response to the anthropogenic perturbation.
Holocene evolution of the Southern Hemisphere westerly winds in transient simulations with global climate models
Authors: Varma V. , Prange M. , Merkel U. , Kleinen T. , Lohmann G. , Pfeiffer M. , Renssen H. , Wagner A. , Wagner S. , Schulz M.
Published: May 2011

Abstract. The Southern Hemisphere Westerly Winds (SWW) have been suggested to exert a critical influence on global climate through wind-driven upwelling of deep water in the Southern Ocean and the potentially resulting atmospheric CO2 variations. The investigation of the temporal and spatial evolution of the SWW along with forcings and feedbacks remains a significant challenge in climate research. In this study, the evolution of the SWW under orbital forcing from the mid-Holocene (7 kyr BP) to pre-industrial modern times (250 yr BP) is examined with transient experiments using the comprehensive coupled global climate model CCSM3. In addition, a model inter-comparison is carried out using orbitally forced Holocene transient simulations from four other coupled global climate models. Analyses and comparison of the model results suggest that the annual and seasonal mean SWW were subject to an overall strengthening and poleward shifting trend during the course of the mid-to-late Holocene under the influence of orbital forcing, except for the austral spring season, where the SWW exhibited an opposite trend of shifting towards the equator.
Runoff regime estimation at high-elevation sites: a parsimonious water balance approach
Authors: Bartolini E. , Allamano P. , Laio F. , Claps P.
Published: May 2011

Abstract. We develop a water balance model, parsimonious both in terms of parameterization and of required input data, to characterize the average runoff regime of high-elevation and scarcely monitored basins. The model uses a temperature threshold to partition precipitation into rainfall and snowfall, and to estimate evapotranspiration volumes. The role of snow in the transformation of precipitation into runoff is investigated at the monthly time scale through a specific snowmelt module that estimates melted quantities by a non-linear function of temperature. A probabilistic representation of temperature is also introduced, in order to mimic its sub-monthly variability. To account for the commonly reported rainfall underestimation at high elevations, a two-step precipitation adjustment procedure is implemented to guarantee the closure of the water balance. The model is applied to a group of catchments in the North-Western Italian Alps, and its performances are assessed by comparing measured and simulated runoff regimes both in terms of total bias and anomalies, by means of a new metric, specifically conceived to compare the shape of the two curves. The obtained results indicates that the model is able to predict the observed runoff seasonality satisfactorily, notwithstanding its parsimony (the model has only two parameters to be estimated). In particular, when the parameter calibration is performed separately for each basin, the model proves to be able to reproduce the runoff seasonality. At the regional scale (i.e., with uniform parameters for the whole region), the performance is less positive, but the model is still able to discern among different mechanisms of runoff formation that depend on the role of the snow storage. Because of its parsimony and the robustness in the approach, the model is suitable for application in ungauged basins and for large scale investigations of the role of climatic variables on water availability and runoff timing in mountainous regions.
The International Soil Moisture Network: a data hosting facility for global in situ soil moisture measurements
Authors: Dorigo W. A. , Wagner W. , Hohensinn R. , Hahn S. , Paulik C. , Xaver A. , Gruber A. , Drusch M. , Mecklenburg S. , van Oevelen P. , Robock A. , Jackson T.
Published: May 2011

Abstract. In situ measurements of soil moisture are invaluable for calibrating and validating land surface models and satellite-based soil moisture retrievals. In addition, long-term time series of in situ soil moisture measurements themselves can reveal trends in the water cycle related to climate or land cover change. Nevertheless, on a worldwide basis the number of meteorological networks and stations measuring soil moisture, in particular on a continuous basis, is still limited and the data they provide lack standardization of technique and protocol. To overcome many of these limitations, the International Soil Moisture Network (ISMN; http://www.ipf.tuwien.ac.at/insitu) was initiated to serve as a centralized data hosting facility where globally available in situ soil moisture measurements from operational networks and validation campaigns are collected, harmonized, and made available to users. Data collecting networks share their soil moisture datasets with the ISMN on a voluntary and no-cost basis. Incoming soil moisture data are automatically transformed into common volumetric soil moisture units and checked for outliers and implausible values. Apart from soil water measurements from different depths, important metadata and meteorological variables (e.g., precipitation and soil temperature) are stored in the database. These will assist the user in correctly interpreting the soil moisture data. The database is queried through a graphical user interface while output of data selected for download is provided according to common standards for data and metadata. Currently (status May 2011), the ISMN contains data of 19 networks and more than 500 stations located in North America, Europe, Asia, and Australia. The time period spanned by the entire database runs from 1952 until the present, although most datasets have originated during the last decade. The database is rapidly expanding, which means that both the number of stations and the time period covered by the existing stations are still growing. Hence, it will become an increasingly important resource for validating and improving satellite-derived soil moisture products and studying climate related trends. As the ISMN is animated by the scientific community itself, we invite potential networks to enrich the collection by sharing their in situ soil moisture data.
Estimation of soil moisture using trapezoidal relationship between remotely sensed land surface temperature and vegetation index
Authors: Wang W. , Huang D. , Wang X.-G. , Liu Y.-R. , Zhou F.
Published: May 2011

Abstract. The trapezoidal relationship between land surface temperature (Ts) and Vegetation Index (VI) was used to estimate soil moisture in the present study. An iterative algorithm is proposed to estimate the vertices of the Ts ~ VI trapezoid theoretically for each pixel, and then Water Deficit Index (WDI) is calculated based on the Ts ~ VI trapezoid using MODIS remotely sensed measurements of surface temperature and enhanced vegetation index (EVI). The capability of using WDI based on Ts ~ VI trapezoid to estimate soil moisture is evaluated using soil moisture observations and antecedent precipitation in the Walnut Gulch Experimental Watershed (WGEW) in Arizona, USA. The result shows that, the Ts ~ VI trapezoid based WDI can capture temporal variation in surface soil moisture well, but the capability of detecting spatial variation is poor for such a semi-arid region as WGEW.
On the colour and spin of epistemic error (and what we might do about it)
Authors: Beven K. , Smith P. J. , Wood A.
Published: May 2011

Abstract. Disinformation as a result of epistemic error is an issue in hydrological modelling. In particular the way in which the colour in model residuals resulting from epistemic errors should be expected to be non-stationary means that it is difficult to justify the spin that the structure of residuals can be properly represented by statistical likelihood functions. To do so would be to greatly overestimate the information content in a set of calibration data and increase the possibility of both Type I and Type II errors. Some principles of trying to identify periods of disinformative data prior to evaluation of a model structure of interest, are discussed. An example demonstrates the effect on the estimated parameter values of a hydrological model.
Endovascular Electrocardiography to Guide Placement of Totally Implantable Central Venous Catheters in Oncologic Patients
Authors: Pelagatti Cecilia , Villa Gianluca , Casini Andrea , Chelazzi Cosimo , De Gaudio Angelo Raffaele
Published: May 2011

Purpose

Appropriate tip position of totally implantable central venous catheters is essential in order to prevent catheter-related complications, in particular thrombosis. Endovascular electrocardiography is an economic and safe method to guide placement of catheters into the central veins. Although widely utilized, there is still lack of conclusive evidence about its efficacy. The aim of the study was to assess the efficacy and safety of endovascular electrocardiographic guided placement compared to the anthropometric method.

Methods

Endovascular ECG was employed to guide electrocardiographic placement of a central venous catheter in a cohort of oncologic patients. The rate of correct placement and the incidence of catheter-related thrombosis were considered. Patients in which central venous catheters were inserted with the anthropometric technique were considered as control group.

Results

The rate of correct placement was 91% and 50% for ECG-guided and anthropometric catheters (p<0.0001) respectively. None of the patients suffered from early insertion-related complications. The rate of catheter-related vascular thrombosis was lower for ECG-guided catheters (3.6% vs. 9.6%, n.s.), in particular for left-inserted catheters (0% vs. 33.3%, p=0.02).

Conclusion

Endovascular electrocardiography was more effective than the anthropometric technique in placement of implantable central venous catheters and was associated with a lower incidence of catheter-related thrombosis, in particular for those inserted from the left-side.
The Electrocardiographic Method for Positioning the Tip of Central Venous Catheters
Authors: Pittiruti Mauro , La Greca Antonio , Scoppettuolo Giancarlo
Published: May 2011

Tip position of a central venous access is of paramount importance and should be verified before starting infusion. Intra-procedural methods for verifying the location of the tip are to be preferred, since they avoid the risks, delays and costs of repositioning the tip. Among the intra-procedural methods, the electrocardiography (EKG) method has many advantages since it is as accurate as fluoroscopy, but simpler, more readily available, less expensive, safer and more cost-effective. The only contraindication to utilizing the EKG method is the difficulty in identifying the standard P-wave on a surface EKG (this happens - usually because of severe arrhythmias, such as atrial fibrillation - in only approximately 7% of cases: although such patients are easily identified before the procedure, and are referred to other methods for tip positioning). When dealing with the insertion of peripherally inserted central catheters (PICC), the EKG method (using the column of saline technique) virtually has no risk of false positives. The EKG method removes the need for the post-procedural chest x-ray, as long as there is no expected risk of pleuropulmonary damage to be ruled out (example: ultrasound guided central venipuncture for central venous catheter insertion or any kind of PICC insertion). In conclusion, evidence is mounting that the EKG method may be a valid and cost-effective alternative to the standard radiological control of the location of the tip of any central venous access device (VAD), and that will rapidly become the preferential method for confirming the tip position during PICC insertion.
The Economic Impact of Yacht Charter Tourism on the Balearic Economy
Authors: Alcover Antonio , Alemany Marga , Jacob Marta , Payeras Margarita , García Antonia , Martínez-Ribes Lorena
Published: May 2011

This paper evaluates the impact of yacht charter tourism on the economy of the Balearic Islands, one of the most popular yachting tourism destinations in the Mediterranean. Empirical evidence, from a sample of yacht charter tourists and a database on charter firms in the Balearics provided by the National Charter Federation, gives information on daily tourist expenditure, the number of charter tourists and firms' turnover and employment. More than 100,000 tourists come annually to the Balearics to charter yachts. Average daily expenditure per tourist, including charter cost and other spending on hotel accommodation, bars and restaurants, shopping and other items, is €170; however, average daily expenditure varies depending on the typology of boat rented. When tourist spending in the country of origin is included, average daily expenditure rises to €203.90. Daily expenditure is higher than that of a traditional tourist (€105.20) and similar to that of a golf tourist (€211). Finally, yacht charter activity in the Balearics contributes to the generation of around 866 jobs in the archipelago.
Interdependence of International Tourism Demand and Volatility in Leading ASEAN Destinations
Authors: Chang Chia-Lin , Khamkaew Thanchanok , Tansuchat Roengchai , McAleer Michael
Published: May 2011

International and domestic tourism are leading economic activities in today's world. Tourism has been known to generate goods and services directly and indirectly, attract foreign currency, stimulate employment and provide opportunities for investment. It has also been recognized as an important means of achieving economic development. Substantial research has been conducted to evaluate the role of international tourism, and its associated volatility, within and across various economies. This paper applies several recently developed models of multivariate conditional volatility to investigate the interdependence of international tourism demand, as measured by international tourist arrivals, and its associated volatility in the four leading destinations in ASEAN, namely Indonesia, Malaysia, Singapore and Thailand. Each of these countries has attractive tourism characteristics, such as significant cultural and natural resources. Shocks to international tourism demand volatility could affect, positively or negatively, the volatility in the tourism demand of neighbouring countries. The empirical results should encourage regional cooperation in tourism development among ASEAN member countries and also mobilize international and regional organizations to provide appropriate policy actions.
Mass Beach Tourism and Economic Growth: Lessons from Tunisia
Authors: Cortés-Jiménez Isabel , Nowak Jean-Jacques , Sahli Mondher
Published: May 2011

This paper examines the relationship between tourism exports, imports of capital goods and economic growth, with special reference to Tunisia over the period 1975–2007. The dynamic interaction between these variables is examined within a vector error correction model using the Johansen technique of cointegration with structural changes and the multivariate Granger causality test. The authors consider that tourism may affect economic growth through two different channels, the TLG and TKIG mechanisms. Their findings reveal a complex picture of the relationship between these variables. There seems to be no TLG mechanism in Tunisia, while the TKIG mechanism appears as a short-run phenomenon only. In total, tourism exports have contributed significantly towards financing the country's imports of capital goods, but they have not been the principal engine of long-term growth. On the contrary, the results support the hypothesis of a growth-led tourism in this country. They also provide evidence of a strong unidirectional causality from economic growth to imports of capital goods.
Evaluation of Agritourism Activity in Italy: Facility Based or Local Culture Based?
Authors: Ohe Yasuo , Ciani Adriano
Published: May 2011

This paper identifies which diversified activities influence the price level of agritourism and how they do so. A hypothesis that contrasts two types of activity (facility based and local culture based) is examined. First, from a conceptual perspective, the authors note that agritourism based on local cultural resources can internalize positive externalities, which are uniquely nurtured local cultural resources, into income – unlike facility based activity that has no connection with local cultural resources. Second, the results of estimations from a price determinant ordered logit model demonstrate that owning a swimming pool is the most common and influential factor in enhancing the price level, while regional diversity is observed in local cultural resource based activities such as restaurants, World Heritage Sites and DOC wines. These findings indicate that hardware based evolution is more effective in the short term than evolution based on software. Nevertheless, this hardware based evolution of agritourism is founded implicitly on an assumption of continuously growing demand and sufficient financial capability for the fixed investment. When growth in demand becomes stagnant, facility installation can be a heavy burden on operators. Consequently, for the sustainable development of agritourism, it will be necessary to harness the locality so as to create a balance between facility based services and local culture based services.
The Significance of Festivals to Regional Economies: Measuring the Economic Value of the Grahamstown National Arts Festival in South Africa
Authors: Saayman Melville , Rossouw Riaan
Published: May 2011

This paper estimates the economic value of South Africa's longest running national arts festival, the Grahamstown National Arts Festival in the Eastern Cape Province. The Eastern Cape is a middle-income province (6.6% of national GDP), settles 9.6% of the South African population and has a high unemployment rate. A survey was conducted in July 2009, with 450 visitors completing a structured questionnaire at various sampling locations across the festival area. A social accounting matrix (SAM) for the province was used to estimate the economic value of the arts festival to the region's economy (adopting the classical SAMs multiplier approach) with visitor depending data. This research shows that the festival makes a significant contribution to revenue generation as well as to job creation, thereby confirming that investments made by government in arts and culture can address economic objectives.
A Microeconomic Model of Multidestination Tourism Trips
Authors: De Oliveira Santos Glauber Eduardo , Ramos Vicente , Rey-Maquieira Javier
Published: May 2011

A significant share of tourism trips includes visits to more than one destination. The only formal theoretical frameworks available for explaining consumers' choices of multidestination tourism trips (MTTs) are based on Lancaster's (1966) characteristics theory. This paper proposes a theoretical model of MTT choices based on the traditional economic theory of consumption. Some particularities of the traditional model regarding MTTs are discussed, such as the proper shape of utility functions, special transport costs and the existence of two budget constraints. The model shows that the MTT paradigm may unfold special demand effects. Negative income effects may be experienced by destinations considered as normal goods, and positive price effects may be experienced by non-Giffen destinations.
Change in the Managerial Efficiency and Management Technology of Hotels: An Application to Thailand
Authors: Untong Akarapong , Kaosa-Ard Mingsarn , Ramos Vicente , Rey-Maquieira Javier
Published: May 2011

This article estimates the change in managerial efficiency and management technology of a sample of hotels in Chiang Mai, Thailand, during 2002–2006. The study applies the data envelopment analysis (DEA) methodology proposed by Banker et al (1984) to examine managerial efficiency in 2002 and 2006. The Malmquist productivity approach developed by Färe et al (1992) is employed to evaluate the change in managerial efficiency and management technology over the same period. The results show that medium-sized and small hotels tend to be more managerially efficient than large hotels. The total factor productivity declined slightly owing to a lack of investment in management technology. Instead, the hotels in the sample concentrated on improving managerial effort. This shortfall in technology investment could hamper productivity in the longer term.
A Composite Leading Indicator for the Hotel Industry
Authors: Tang Candy Mei Fung , Kulendran Nada
Published: May 2011

This study constructs composite leading indicators to predict turns in the growth cycle of hotel occupancy for hotels in Hong Kong with different tariffs, as well as for all hotels in Hong Kong. First, a composite leading indicator for each of the top five source markets – mainland China, Taiwan, Japan, the USA and South Korea – was constructed using selected economic variables. Second, a composite leading indicator for all hotel categories in Hong Kong was constructed by combining the leading indicators constructed for each source market, using tourism market share and the cross-correlation coefficient as weightings. Third, the combined composite indicator was compared with the published OECD composite leading indicator and the OECD business survey index, which were constructed using the same weighting methods. In order to identify the best weighting method and to select the best composite leading indicator for different tariff categories of hotels, this study assessed the probability forecasts from the logistic regression leading indicator models using the quadratic probability score (QPS). The result shows that the composite leading indicator combined with tourism market share provides more accurate forecasts than the composite leading indicator combined with the coefficient of correlation.
Seasonal Pattern and Amplitude – a Logical Framework to Analyse Seasonality in Tourism: An Application to Bed Occupancy in Sicilian Hotels
Authors: De Cantis Stefano , Ferrante Mauro , Vaccina Franco
Published: May 2011

Many studies have investigated seasonality in tourism in terms of its causes and impacts, from both theoretical and applied perspectives. However, the definition of seasonality and, most of all, its application and measurement have not received the same degree of attention. In recognizing that seasonality has two main facets – pattern and amplitude – this paper critically examines the main seasonality measures proposed in the tourism literature, classifying them according to their properties and their most appropriate use. The framework then proposed is used to analyse a standard and comparable efficiency measure, such as the bed occupancy rate of Sicilian accommodation establishments, placing particular attention on its seasonality.
Trade and Value Developments in the Danish Second-Home Sector: Implications for Tourism Policies
Authors: Hjalager Anne-Mette , Staunstrup Jan Kloster , Ibsen Rikke
Published: May 2011

The 220,000 second homes in Denmark are very important tourism and leisure resources. This study documents the development in property values and the trade in second homes during the period 1994–2008 and links property values to socio-economic characteristics, events in the lives of the owners and geography. The study finds that ownership of second homes is still fairly well distributed socially, but that there is a clear trend towards the exclusion of those with lower incomes and of families with children. The average age of owners is rising. Second homes play a subtle role not only as holiday resources, but also in the combined housing economy and investment of Danish families. Indirectly, the developments in the trade and value of second homes have implications for future tourism policies. The continuous availability of privately owned second homes on the rental market is of immense importance for the attractiveness of the Danish tourism product in general, and for specific destinations in particular. Rising property prices in the years up to 2008 and a lack of incentives to upgrade the standard of these houses may compromise mainstream Danish tourism policies.
Measuring the Economic Value and Social Viability of a Cultural Festival as a Tourism Prototype
Authors: Herrero Luis César , Sanz José ángel , Devesa María
Published: May 2011

Cities with an important historical cultural heritage are aiming to strengthen their appeal to tourists by organizing numerous complementary activities, such as music festivals, in an attempt to consolidate and enhance their image as cultural sites and diversify the flow of tourism demand. This paper estimates the willingness to pay for a music festival in the city of Santiago de Compostela, Spain, and analyses the results according to the socio-demographic and behavioural characteristics of audiences and tourists. The authors use the contingent valuation method, an appropriate technique for valuing non-market public goods, yet one that has scarcely been employed in the case of cultural goods of a temporary nature, such as a music festival. The findings to emerge may prove useful in understanding the demand for these goods, as well as in measuring the social viability of these tourist projects if willingness to pay is taken as an estimate of derived social benefit. This outcome may prove suitable input for a cost–benefit analysis.
Terrorism and Tourism in Developed versus Developing Countries
Authors: Thompson Alexi
Published: May 2011

This paper compares the effect of terrorism on the tourism industry in developing and developed countries. Analysis of a cross-sectional data set of 60 countries supports the hypothesis that terrorism's effect on the tourism industry is larger in developing countries than in developed countries. Based on this result, developing countries especially should implement ways to prevent terrorism and avoid the detrimental effects on their tourism industry.
Thrombotic Occlusion of All Left Coronary Branches in a Young Woman with Severe Ulcerative Colitis
Authors: Gustavsson Carl Gunnar , Svensson Peter J. , Hertervig Erik , Sandhall Lennart , Hårdhammar Peter , Malcevschi-Lind Natascia , Olsson Sven-Erik
Published: May 2011

Background. The thrombosis risk is increased in active ulcerative colitis. The limited number of reported complications have predominantly been cerebrovascular but other vessel territories may also be affected. Patient. During a severe attack of ulcerative colitis a 37-year-old woman suffered occlusion of all left coronary artery branches. Serial angiographies showed progressive recanalisation of the coronary arteries during anticoagulation, but no atherosclerotic stenosis. The cause of infarction was thus considered to be an extensive coronary thrombosis. However, a large battery of blood tests failed to identify any procoagulant abnormality. Conclusion. Evidence is now accumulating that the increased thrombosis risk also may involve the coronary arteries, even in young patients. To the best of our knowledge this is the third reported case of myocardial infarction despite angiographically normal coronary arteries in a patient with active ulcerative colitis. The extent of affected myocardium was in this case exceptionally large.
A Case of Primary Tubercular Mastitis Masquerading as Carcinoma Breast
Authors: Singhal Sameer
Published: May 2011

Primary extrapulmonary tuberculosis occurring in the breast is extremely rare. In the absence of well-defined clinical features, the true nature of the disease remains obscure and it is often mistaken for carcinoma or pyogenic breast abscess. It also presents a diagnostic problem on radiological and microbiological investigations and thus high index of suspicion acquires an important position. This paper highlights the importance of considering every breast lump as a potential case of tubercular mastitis especially in endemic countries like India that should be subjected to fine needle aspiration cytology or excisional biopsy before considering surgical options like complete mastectomy, without relying only on clinicoradiological findings.
Tooth Extraction in Patients on Oral Anticoagulants: Prospective Study Conducted in 108 Brazilian Patients
Authors: Pereira Claudio Maranhão , Gasparetto Patrícia Freire , Carneiro Danilo Santos , Corrêa Maria Elvira P. , Souza Cármino Antônio
Published: May 2011

Introduction. Dental treatment performed in patients receiving continuous oral anticoagulant drug therapy is becoming increasingly common in dental offices. For these patients it is imperative to carry out careful anamnesis, as well as a multiprofessional clinical evaluation with regard to the risk and control of hemorrhagic or thromboembolic episodes.
Objectives and Material and Methods. The aim is to evaluate postextraction hemorrhagic or thromboembolic episodes in patients who have been on anticoagulant medications for an uninterrupted period of 48 months.
Results. Among the 108 patients evaluated, 215 extractions were performed in which there was only one case of postoperative bleeding. Warfarin was used by 98 patients; Warfarin associated with salicylic acetic acid by 9 patients and salicylic acetic acid in only 1 patient. As regards the serologic tests performed, International Normalized Ratio (INR) ranged from 0.8 to 4.9, with a mean of 3.15.
Conclusion. Extractions in patients on oral anticoagulants must be performed in the least traumatic manner possible. It is not necessary to stop anticoagulant therapy to perform extractions. Local hemostasis techniques, such as obliterative sutures alone are sufficient to prevent hemorrhagic complications.
Urinary Ascites following Mini Lap Tubectomy: A Rare Occurence
Authors: Dahiya Pushpa , Paul Anshu , Dalal Satish
Published: May 2011

Iatrogenic bladder injury is a known complication of laparoscopic and gynecological surgeries with an incidence of 1.5 per 1000 cases. Urinary ascites is a result of undiagnosed iatrogenic bladder injury during pelvic surgeries. We report a rare case of urinary ascites following mini lap tubectomy on the eighth postoperative day. After the diagnosis was made, conservative management was done for the patient, to which she successfully responded.
Genetic Characterization of Porcine Circovirus Type 2 from Pigs with Porcine Circovirus Associated Diseases in Argentina
Authors: Pereda Ariel , Piñeyro Pablo , Bratanich Ana , Quiroga María Alejandra , Bucafusco Danilo , Craig María Isabel , Cappuccio Javier , Machuca Mariana , Rimondi Agustina , Dibárbora Marina , Sanguinetti Hector Ramón , Perfumo Carlos Juan
Published: May 2011

Porcine circovirus type 2 (PCV-2) has been associated with syndromes grouped by the term porcine circovirus associated diseases (PCVAD). The PCV-2 isolates have been grouped into two major groups or genotypes according to their nucleotide sequence of whole genomes and/or ORF-2: PCV-2b, which have, in turn, been subdivided into three clusters (1A–1C), and PCV-2a, which has been subdivided into five clusters (2A–2E). In the present study, we obtained 16 sequences of PCV-2 from different farms from 2003 to 2008, from animals with confirmatory diagnosis of PCVAD. Since results showed an identity of 99.8% among them, they were grouped within a common cluster 1A-B. This preliminary study suggests a stable circulation of PCV-2b among the Argentinean pig population.
Exercise-Induced Right Ventricular Outflow Tract Tachycardia in a Patient with Isolated Left Ventricular Noncompaction
Authors: Güvenç Tolga Sinan , İlhan Erkan , Alper Ahmet Taha , Eren Mehmet
Published: May 2011

Isolated left ventricular noncompaction is a hereditary cardiomyopathy in which a variety of supraventricular and ventricular arrhythmias could be observed. We report a patient with exercise-induced ventricular tachycardia with left bundle branch block morphology that had characteristics of an idiopathic ventricular tachycardia who was subsequently diagnosed as left ventricular noncompaction. Successful remission of arrhythmia was ensured after the introduction of oral beta-blocker therapy.
Existence Results for Boundary Value Problems of Differential Inclusions with Three-Point Integral Boundary Conditions
Authors: Ahmad Bashir , Ntouyas Sotiris K. , Alsaedi Ahmed
Published: May 2011

We discuss the existence of solutions for a boundary value problem of second-order differential inclusions with three-point integral boundary conditions involving convex and nonconvex multivalued maps. Our results are based on the nonlinear alternative of Leray-Schauder type and some suitable theorems of fixed point theory.
Pharmacogenomics in neurology: Current state and future steps
Authors: Chan Andrew , Pirmohamed Munir , Comabella Manuel
Published: June 2011

In neurology, as in any other clinical specialty, there is a need to develop treatment strategies that allow stratification of therapies to optimize efficacy and minimize toxicity. Pharmacogenomics is one such method for therapy optimization: it aims to elucidate the relationship between human genome sequence variation and differential drug responses. Approaches have focused on candidate approaches investigating absorption‐, distribution‐, metabolism, and elimination (ADME)‐related genes (pharmacokinetic pathways), and potential drug targets (pharmacodynamic pathways). To date, however, only few genetic variants have been incorporated into clinical algorithms. Unfortunately, a large number of studies have thrown up contradictory results due to a number of deficiencies, including small sample sizes, inadequate phenotyping, and genotyping strategies. Thus, there still exists an urgent need to establish biomarkers that could help to select for patients with an optimal benefit to risk relationship. Here we review recent advances, and limitations, in pharmacogenomics for agents used in neuroimmunology, neurodegenerative diseases, ischemic stroke, epilepsy, and primary headaches. Further work is still required in all of these areas, which really needs to progress on several fronts, including better standardized phenotyping, appropriate sample sizes through multicenter collaborations and judicious use of new technological advances such as genome‐wide approaches, next generation sequencing and systems biology. In time, this is likely to lead to improvements in the benefit‐harm balance of neurological therapies, cost efficiency, and identification of new drugs. Ann Neurol 2011
Mathematical concept of the Bloch flow equations for general magnetic resonance imaging: A review
Authors: Awojoyogbe O.B. , Dada O.M. , Faromika O.P. , Dada O.E.
Published: May 2011

The recent analytical solutions to the Bloch NMR equations for a general RF excitation have opened many possibilities for further investigations to NMR theory and experiments even at the molecular level. Fortunately, many of the most important but hidden applications of blood flow and general physiological fluid flow parameters can be revealed without too much difficulty if appropriate mathematical techniques are used to explore the new NMR equations derived from the Bloch equations. Generally, we should be very much concerned with analytical results that the Bloch NMR flow equations can provide for different physical, biomedical, geophysical, medical, and environmental situations especially at the molecular level for the purpose of interdisciplinary approach to solve difficult problems. It can be motivating, exciting, and rewarding if attention are focused on the possible application of these analytical techniques and methods suitable for describing each of the various normal and pathological biological conditions. Most solutions presented in this study are described both in isotropic and anisotropic geometries with minimum mathematical assumptions. We discussed a general expression for the diffusion coefficients in the common geometries. These analytical results can prove to be very invaluable in the analysis of restricted flows. It is so much special because it could tell us when restricted flows occur and also reveal the causes of such restriction. Such knowledge can help in finding the causes of many diseases (whose causes are yet unknown) and suggest the best treatment for them. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part A 38A: 85–101, 2011.
Analysis of polycrystal acrylamide by electron spin resonance and thermo‐analytical methods
Authors: Usta Ayhan , Filiz Ali , Birey Mehmet , Ozmen Ayhan
Published: May 2011

Electron spin resonance (ESR), thermogravimetry analysis (TGA), and differential thermal analysis (DTA) were performed on acrylamide (C3H5NO) polycrystal samples. The samples were irradiated at 298 K for 24, 48, 72, and 96 h using 60Co – gamma source. ESR measurements were carried out between 120 and 450 K. The ESR signals were recorded from the samples exposed to 60Co – gamma rays for 72 and 96 h. Between 120 and 450 K the spectra changed in a manner roughly. It was detected by means of e.s.r. spectra that unpaired electron took place due to scission of pi bond in the carbon–carbon double bonds in the substance. The produced radiation damage center on the sample was attributed to ·CH2‐CH‐R Additionally, thermal behavior of the acrylamide samples were investigated by using TGA and DTA methods. It was observed that both irradiated and not irradiated samples decomposed at three steps. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part A 38A: 102–106, 2011.
Analysis of NMR spectra in case of temperature‐dependent chemical exchange between two unequally populated sites
Authors: Římal Václav , Štěpánková Helena , Štěpánek Josef
Published: May 2011

A new approach is introduced for analysis of nuclear magnetic resonance (NMR) spectra measured under conditions of asymmetric chemical exchange. It is based on a simultaneous least‐square fit of a due analytical formula to the experimental NMR spectrum. For this reason, we derived the analytical solution of Bloch‐McConnell equations describing the spectral lineshape in the case of the free induction decay and chemical exchange between two unequally populated sites. The obtained formula is shown to be in agreement with the one derived for continuous wave NMR experiments first published in fifties. On the other hand, typing errors were found in formulae presented in later monographs. Applicability of the approach to extensive NMR data was demonstrated on proton NMR spectra of a self‐complementary oligodeoxynucleotide d(GATGCATC) measured at various temperatures covering the duplex melting. The lineshape analysis of aromatic proton signals provided us the temperature dependence not only of the equilibrium ratio between duplexes and single strands, but also of the kinetics of duplex formation and dissociation, which is not obtainable for a sample in the state of thermodynamic equilibrium by other methods. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part A 38A: 117–127, 2011.
Converting the chemical shift artifact to a spectral image
Authors: Servoss Thomas G. , Hornak Joseph P.
Published: May 2011

The chemical shift artifact in magnetic resonance imaging is an undesirable misregistration of components of an image due to their chemical shift differences. The artifact is most prevalent at high magnetic fields with small field gradients and low sampling rates. Exploiting this relationship allows the acquisition of spectral information for each and every voxel of a magnetic resonance image, which in turn provides the opportunity for multispectral diagnosis and analysis approaches. A method of transforming a set of images with different amounts of the chemical shift artifact into a spatial–spatial‐spectral image is presented. The transformation is demonstrated on tomographic magnetic resonance images of a chemical shift phantom and the human leg. As with all spectral imaging techniques, this one is also sensitive to magnetic susceptibility variations across the field of view. The technique can readily separate water and lipid and has a spectral resolution approaching 0.4 ppm. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part A 38A: 107–116, 2011.
Proof that gmT2 is the reciprocal of gmR2
Authors: Bjarnason Thorarin A.
Published: May 2011

When performing multiexponential analysis of relaxation times in the slow exchange regime, it is often convenient to simplify the resulting distribution to one or more relaxation time constants. In doing so, what averaging method should be used and should the rate constant or time constant be reported? This note outlines why the geometric mean is most appropriate and provides a proof that the geometric mean rate and geometric mean time constants are reciprocals, which is counter‐intuitive unless one considers that averaging values in a distribution is different than physically averaging relaxation species. © 2011 Wiley Periodicals, Inc. Concepts Magn Reson Part A 38A: 128–131, 2011.
Intradialytic exercise: A pilot program
Authors: Davis Jane S. , Holcombe Judith
Published: June 2011

Intradialytic exercise is both safe and beneficial for patients; however, worldwide, despite evidence to support its efficacy, it is underutilized. A pilot project in a large inner city hemodialysis unit demonstrated the benefits of introducing a program to improve physical function among the participants.
Association between participant‐identified problems and depression severity in problem‐solving therapy for low‐income homebound older adults
Authors: Choi Namkee G. , Hegel Mark T. , Marinucci Mary Lynn , Sirrianni Leslie , Bruce Martha L.
Published: June 2011

Objectives

The purpose of this study was to examine the relationship between the severity of baseline depressive symptoms and the problems that low‐income homebound older adults (n = 66) identified in their problem‐solving therapy (PST) sessions.

Methods

Depressive symptoms were measured with the 24‐item Hamilton Rating Scale for Depression (HAMD). Participant‐identified problems recorded in the therapists' worksheets were coded into seven categories: living arrangement/housing issues, financial/health care expense issues, family or other relationship issues, hygiene/task issues, social isolation issues, physical/functional health issues, and mental/emotional health issues. T‐tests and ordinary least squares regression analyses were used to examine differences in HAMD scores between those who identified any problem in each category and those who did not.

Results

Participants who had living arrangement/housing and family or other relationship issues had higher baseline HAMD scores than the rest of the participants. At 2‐week posttest, those with living arrangement/housing issues continued to have higher HAMD scores than the others, whereas those with family or other relationship issues did not.

Conclusion

The study findings provide insights into the problems that low‐income, depressed homebound individuals bring to their PST sessions. It was not clear if family conflict or other relationship issues contributed to their depression or vice versa, but it appears that PST may have contributed to alleviating depressive symptoms associated with these issues. Precarious living/housing situations appeared to have had a serious depressogenic effect and could not be easily resolved within a short time frame of the PST process, as these issues required formal support. Copyright © 2011 John Wiley & Sons, Ltd.
Association between plasma paroxetine concentration and changes in plasma brain‐derived neurotrophic factor levels in patients with major depressive disorder
Authors: Yasui‐Furukori Norio , Tsuchimine Shoko , Nakagami Taku , Fujii Akira , Sato Yasushi , Tomita Tetsu , Yoshizawa Kaori , Inoue Yoshimasa , Kaneko Sunao
Published: June 2011

Recent studies have implicated brain‐derived neurotrophic factor (BDNF) in the pathophysiology of depression and in the activities of antidepressant drugs. Serum BDNF levels are lower in depressed patients and increase in response to antidepressant medications; however, no studies have examined the association between plasma concentrations of antidepressant drugs and plasma BDNF levels. We assessed plasma BDNF levels and paroxetine concentrations in 45 patients with major depression who were being treated with paroxetine. Plasma samples were collected between 10:00 h and 12:00 h at baseline and after 1, 2 and 6 weeks of treatment. The BDNF level and paroxetine concentration of each sample were measured via enzyme immunoassay and high‐performance liquid chromatography, respectively. Plasma BDNF levels increased after 2 and 6 weeks of paroxetine treatment. Plasma BDNF levels were significantly lower in men than in women. Changes in plasma BDNF level were correlated with plasma drug concentration after 2 (r = 0.309, p < 0.05) and 6 weeks (r = 0.329, p < 0.05) but not correlated with plasma drug concentration after 1 week (r = 0.284, ns). Multiple regression analysis confirmed that this change was only significantly correlated with plasma paroxetine concentration after 2 (standardised beta = 0.343, p < 0.05) and 6 weeks (standardised beta = 0.375, p < 0.05). These results suggest that paroxetine treatment increases plasma BDNF levels and that plasma paroxetine levels play an important role in changes in plasma BDNF levels. Copyright © 2011 John Wiley & Sons, Ltd.