bluuebunny/crossref_metadata_2025 huggingface dataset:
Climate and land use interactively affect lake phytoplankton nutrient limitation status
Authors: Hayes Nicole M. , Vanni Michael J. , Horgan Martin J. , Renwick William H.
Published: August 2014

Climate‐change models predict more frequent and intense summer droughts for many areas, including the midwestern United States. Precipitation quantity and intensity in turn drive the rates and ratios at which nitrogen (N) and phosphorus (P) are exported from watersheds into lakes, but these rates and ratios are also modulated by watershed land use. This led us to ask the question, is the effect of precipitation on phytoplankton nutrient limitation dependent on watershed land use? Across 42 lakes, we found that phytoplankton in lakes in agricultural landscapes were usually P limited but shifted to strong N limitation under increased drought intensity, and that droughts promoted N‐fixing cyanobacteria. In contrast, phytoplankton in lakes with forested watersheds were consistently N limited, regardless of drought status. This climate–land use interaction suggests that droughts may increase the incidence of N limitation in agriculturally impacted lakes. N limitation would likely impair valuable ecosystem services such as drinking water, fisheries, and recreation by promoting the occurrence and severity of cyanobacterial blooms.
Charcoal carbon pool in North American boreal forests
Authors: Hart S. A. , Luckai N. J.
Published: August 2014

Wildfire is the primary disturbance mechanism in much of the boreal forest, initiating succession and influencing ecosystem processes. While most organic matter is consumed, a small amount is converted to charcoal. Fire derived charcoal is highly resistant to mineralization, acting as a recalcitrant C pool, as well as contributing to ecosystem function through nutrient retention and nitrification. In this study we examined the charcoal content of soils across a 14–208‐year post‐fire chronosequence in the southern boreal forest of North America, and compared wildfire derived charcoal to laboratory produced charcoal. Charcoal stocks averaged 4.09 Mg ha−1 representing 2.19 Mg C ha−1; 8–10% of soil C in typical boreal soils. NMR results showed charcoal to be primarily aryl C with smaller amounts of alkyl‐C, O‐alkyl, and methoxyl groups. Charcoal stocks changed substantially over time with C content declining from 56% to 46% and a loss of more labile C groups. Charcoal from stands greater than 140 years old was almost entirely aryl C. Laboratory produced charcoal between 300 and 350°C was found to have comparable properties to wildfire charcoal. Charcoal C stocks in our study are 2–3 times greater than those reported for Eurasian boreal ecosystems, where non‐stand replacing fire is the predominant disturbance; suggesting global estimates of boreal charcoal C stocks may need to be revised upwards to account for greater wildfire intensity in North American boreal forests. Boreal charcoal stocks in this study were found to represent an important long‐term soil C stock, large enough to affect soil processes. Changes in C content and chemical composition, however, occur over time, especially in the first ∼100 years. In the absence of fire, management of boreal charcoal stocks may be required to maintain ecosystem function and C balance.
Net primary production and soil respiration in New England hemlock forests affected by the hemlock woolly adelgid
Authors: Finzi Adrien C. , Raymer Poliana C. L. , Giasson Marc-André , Orwig David A.
Published: August 2014

The abundance of eastern hemlock (Tsuga canadensis) in eastern US forests has declined since the 1950s owing to the introduction of the non‐native insect, hemlock woolly adelgid (HWA, Adelges tsugae). In southern New England, eastern hemlock is being replaced by the deciduous tree species, black birch (Betula lenta). To date there is little understanding of whether hemlock loss will fundamentally alter ecosystem C balance and component fluxes. In this study, we use a comparative approach to study potential changes in C fluxes and N cycling associated with HWA‐induced hemlock decline and replacement. The stands include primary‐ and secondary‐growth hemlock forests (>230 and 132 years old, respectively), recently disturbed stands (5 and 18 years old) that now have rapidly growing black birch saplings, and a mature black birch stand of age similar to the second‐growth hemlock stand. We found that aboveground net primary production was higher in the aggrading black birch stand and significantly so at 18‐years post‐HWA compared to the secondary‐hemlock stand it would likely replace. Rapid forest regrowth was accompanied by significantly higher rates of N uptake from the soil but also higher N‐use efficiency because most of the N taken up from the soil was allocated to the production of wood with a high C‐to‐N ratio. In contrast to patterns of aboveground production, the rate of soil respiration was lowest in the young stands and not significantly different from the second‐growth hemlock stand, suggesting little net effect of stand replacement on soil C efflux. The leaf litter decomposition study showed that black birch litter decomposed more rapidly than hemlock litter but that there was no effect of stand type on the rate of decomposition. Analyses of extracellular microbial exoenzyme activity painted a more nuanced pattern of variation among stands, with fine root biomass the only weakly explanatory variable. In combination with our prior work on C stocks, these results suggest that forests affected by HWA in southern New England will remain a sink for atmospheric CO2 despite reorganization of stand structure and species composition.
Managing landscapes for multiple objectives: alternative forage can reduce the conflict between deer and forestry
Authors: Jarnemo Anders , Minderman Jeroen , Bunnefeld Nils , Zidar Josefina , Månsson Johan
Published: August 2014

Deer (Cervidae) cause considerable damage to forest plantations, crops, and protected habitats. The most common response to this damage is to implement strategies to lower population densities. However, lowering deer density may not always be desirable from hunting, recreational, or conservation perspectives. Therefore, knowledge is needed about additional factors beyond deer density that affect damage levels, and management actions that consider competing management goals. We studied the relationships between levels of bark‐stripping by red deer (Cervus elaphus) on Norway spruce (Picea abies) and (1) relative deer density indices (pellet group count and deer harvest data), (2) availability of alternative natural forage (cover of forage species) and (3) proportion forest in the landscape, both at a forest stand scale and at a landscape scale. Extensive variation in damage level was evident between the six study areas. On a stand scale, the proportion of spruce damaged was positively related to pellet group density, indicating the importance of local deer usage of stands. In addition, available alternative forage in the field layer within spruce stands and proportion forest surrounding stands was negatively related to damage level. On the landscape scale, damage level was negatively related to availability of forage in the field and shrub layers and proportion forest, but was not related to any of the relative deer density indices. Increasing alternative forage may thus decrease damage and thereby reduce conflicts. Additionally, the proportion of forest in the landscape affects damage levels and should thus be considered in landscape planning and when forecasting damage risk. The relationship between local deer usage of stands and damage level suggests that future studies should try to separate the effects of local deer usage and deer density.
Experimental Study of the Fracture and Matrix Effects on Free-Fall Gravity Drainage With Micromodels
Authors: Moghaddam Mehdi Bahari , Rasaei Mohammad Reza
Published: August 2014

Free-fall gravity drainage (FFGD) is the main production mechanism in the gas-invaded zone of fractured reservoirs. The gravity and capillary forces are two major forces that control the production performance of a fractured system under an FFGD mechanism. Gravity force acts as a driving force to remove oil from the matrix block whereas the resistive capillary force tends to keep oil inside the matrix. In this study, a series of experiments was performed to study the effects of the geometrical characteristics of the fracture and matrix on the oil-production rate under an FFGD mechanism by use of a glass micromodel. The oil-recovery factor (RF) was also obtained for a single matrix block by use of different patterns. Results from the experiments show that different flow regimes occur during the production life of a single matrix block under a FFGD mechanism. The fluid flow is controlled by the capillary-dominated regime at the early stage and late time of production life, whereas it shows a stabilized bulk flow under a gravity-dominated regime is exhibited at other times. Experimental results revealed that for a narrow fracture opening, fracture capillary pressure has a form similar to that of the matrix block. Also, it was observed that the oil-production rate and RF of the matrix block decreased as the permeability ratio between two media (matrix block and fracture) increased. Lower production rate is achieved in larger-fracture-spacing micromodels. In addition, wider vertical fractures lead to an early breakthrough of gas in bottom horizontal fracture that makes up the main portion of oil traps in the matrix block, and this reduces the RF. Results from this study show that in a heterogeneous layered matrix block, both the drainage rate and RF decrease in comparison with a homogeneous matrix block. Finally, a multiple linear-regression analysis was performed to understand the dimensionless groups affecting the RF of the FFGD process. It was found that the Bond number cannot truly describe the process and other parameters such as the fracture-/matrix-permeability ratio; fracture spacing and fracture opening should also be considered.
Sailing Can Improve Quality of Life of People with Severe Mental Disorders: Results of a Cross Over Randomized Controlled Trial
Authors: Carta Mauro Giovanni , Maggiani Federica , Pilutzu Laura , Moro Maria Francesca , Mura Gioia , Sancassiani Federica , Vellante Vellante , Migliaccio Gian Mario , Machado Sergio , Nardi Antonio Egidio , Preti Antonio
Published: August 2014

The aim of this study was to evaluate the impact of a sailing rehabilitation program on the quality of life (QoL) in a sample of patients with severe mental disorders. The study adopted a randomized, crossover, waiting-list controlled design. The participants enrolled in the study were outpatients diagnosed with severe chronic mental disorders. The participants (N=40) exposed to rehabilitation with sailing took part in a series of supervised cruises near the gulf of Cagliari, South Sardinia, and showed a statistically significant improvement of their quality of life compared to the control group. This improvement was comparable to the improvement in psychopathologic status and social functioning as shown in a previous report of the same research project. The improvement was maintained at follow-up only during the trial and for a few months later: after 12 months, patients returned to their baseline values and their quality of life showed a worsening trend. This is the first study to show that rehabilitation with sailing may improve the quality of life of people with severe chronic mental disorders. In all likelihood, a program grounded on learning how to manage a sailing vessel - during which patients perform cruises that emphasize the exploration of the marine environment by sailing - might be interesting enough and capture the attention of the patients so as to favour greater effectiveness of standard rehabilitation protocols, but this should be specifically tested.
Are Blood Transfusions Useful for Non-Specific Symptoms of Anemia in the Elderly?
Authors: Raza Sakeena , Wei Jeanne , Ashad Abid Syed , Azhar Gohar
Published: August 2014

Background:

Over 10% of adults older than 65 years have World Health Organization defined anemia (Hemoglobin lower than13 g/dl in men and 12 g/dl in women). It is more prevalent with increasing age, exceeding 20% in the very elderly (85 years and older). Typical symptoms of anemia are nonspecific and often attributed to aging or to an exacerbation of another illness in the elderly.

Methods:

We present a case series of patients between ages 65-99 years who were followed at the Senior Health clinic and presented with nonspecific symptoms. All these patients were found to have life-threatening anemia requiring blood transfusions.

Design:

Case series.

Results:

All our elderly patients experienced good outcomes in terms of resolution of their symptoms and improvement in functional status. There was a significant difference in the total number of symptoms pre-transfusion compared with symptoms post-transfusion (p < 0.01). There were no adverse outcomes.

Conclusion:

Our case series suggests that symptoms of anemia in the elderly are often attributed to aging or other disease co-morbidities. Nonspecific symptoms like dyspnea, fatigue and confusion should not be ignored. Management decisions regarding anemia should involve functional assessment of the elderly subject. Immediate arrangements for transfusion must be made if the elderly patient is symptomatic regardless of the hemoglobin level. If monitored appropriately, blood transfusions can prolong survival, improve quality of life and functional status of the older individual.
Associations and Outcomes of Septic Pulmonary Embolism
Authors: Goswami Umesh , Brenes Jorge A , Punjabi Gopal V , LeClaire Michele M , Williams David N
Published: August 2014

Background:

Septic pulmonary embolism is a serious but uncommon syndrome posing diagnostic challenges because of its broad range of clinical presentation and etiologies.

Objective:

To understand the clinical and radiographic associations of septic pulmonary embolism in patients presenting to an acute care safety net hospital.

Methods:

We conducted a retrospective analysis of imaging and electronic health records of all patients diagnosed with septic pulmonary embolism in our hospital between January 2000 and January 2013.

Results:

41 episodes of septic pulmonary embolism were identified in 40 patients aged 17 to 71 years (median 46); 29 (72%) were men. Presenting symptoms included: febrile illness (85%); pulmonary complaints (66%) including pleuritic chest pain (22%), cough (19%) and dyspnea (15%); and those related to the peripheral foci of infection (24%) and shock (19%). Sources of infection included: skin and soft tissue (44%); infective endocarditis (27%); and infected peripheral deep venous thrombosis (17%). 35/41 (85%) were bacteremic with staphylococcus aureus. All patients had peripheral nodular lesions on chest CT scan. Treatment included intravenous antibiotics in all patients. Twenty six (63%) patients required pleural drainage and/or drainage of peripheral abscesses. Seven (17%) patients received systemic anticoagulants. Eight (20%) patients died due to various complications.

Conclusion:

The epidemiology of septic pulmonary embolism has broadened over the past decade with an increase in identified extrapulmonary, non-cardiac sources. In the context of an extrapulmonary infection, clinical features of persistent fever, bacteremia and pulmonary complaints should raise suspicion for this syndrome, and typical findings on the chest CT scans confirm the diagnosis. Antibiotics, local drainage procedures and increasingly, anticoagulation are keys to successful outcomes.
Glycolysis in Patients with Age-Related Macular Degeneration
Authors: Yokosako Kanako , Mimura Tatsuya , Funatsu Hideharu , Noma Hidetaka , Goto Mari , Kamei Yuko , Kondo Aki , Matsubara Masao
Published: August 2014

Purpose:

Retinal adenosine triphosphate is mainly produced via glycolysis, so inhibition of glycolysis may promote the onset and progression of age-related macular degeneration (AMD). When glycolysis is inhibited, pyruvate is metabolized by lactic acid fermentation instead of entering the mitochondrial tricarboxylic acid (TCA) cycle. We measured urinary pyruvate and lactate levels in patients with AMD.

Methods:

Eight patients with typical AMD (tAMD group) and 9 patients with polypoidal choroidal vasculopathy (PCV group) were enrolled. Urinary levels of pyruvate, lactate, α-hydroxybutyrate, and β-hydroxybutyrate were measured in all patients.

Results:

The mean urinary levels of pyruvate and lactate were 8.0 ± 2.8 and 7.5 ± 8.3 μg/mg creatinine (reference values: 0.5-6.6 and 0.0-1.6), respectively, with the mean increase over the reference value being 83.6 ± 51.1% and 426.5 ± 527.8%, respectively. In 12 patients (70.6%), the lactate/pyruvate ratio was above the reference range. Urinary levels of α-hydroxybutyrate and β-hydroxybutyrate were decreased by -31.9 ± 15.2% and -33.1 ± 17.5% compared with the mean reference values. There were no significant differences of any of these glycolysis metabolites between the tAMD and PCV groups. Multivariate analysis revealed that none of the variables tested, including patient background factors (age, hypertension, diabetes, hyperlipidemia, cerebrovascular disease, alcohol, smoking, visual acuity, and AMD phenotype), were significantly associated with the lactate/pyruvate ratio.

Conclusion:

A high lactate/pyruvate ratio is a well-known marker of mitochondrial impairment, and it indicates poor oxidative function in AMD. Our results suggest that increased lactate levels may be implicated in the pathogenesis of AMD.
Enhancing Auditor Professional Skepticism: The Professional Skepticism Continuum
Authors: Glover Steven M. , Prawitt Douglas F.
Published: August 2014

This summary is based on a paper by Glover and Prawitt (2013) that was commissioned and published by the Standards Working Group of the Global Public Policy Committee, a working group that comprises the six largest international audit networks. The application of professional skepticism by auditors is important to audit quality. However, various definitions of, and perspectives on, professional skepticism exist in the auditing literature. We propose a “professional skepticism continuum” that acknowledges that the appropriate application of professional skepticism will depend on the risk characteristics of the account and assertion. We also lay out the different structural levels where professional skepticism is applied and where threats to its appropriate application can arise. We argue that regulation can actually threaten the appropriate application of auditor skepticism if regulation and/or inspection focus is not properly aligned with relevant audit risks. Finally, we provide some ideas and recommendations on how the application of professional skepticism might be enhanced on the part of auditors, as well as how other key stakeholders can contribute to its effective application.
Comments by the Auditing Standards Committee of the Auditing Section of the American Accounting Association on PCAOB Release No. 2013-009, Proposed Rule on Improving the Transparency of Audit: Proposed Amendments to PCAOB Auditing Standards to Provide Disclosure in the Auditor's Report of Certain Participants in the Audit
Authors: Anderson Urton L. , Gaynor Lisa Milici , Hackenbrack Karl E. , Lisic Ling Lei , Wu Yi-Jing
Published: August 2014

On December 4, 2013 the Public Company Accounting Oversight Board (PCAOB) solicited public comments on its reproposed amendments to its standards that would improve the transparency of public company audits. The amendments would require (1) disclosure in the auditor's report of the name of the engagement partner, and (2) disclosure in the auditor's report of the names, locations, and extent of participation of other independent public accounting firms that took part in the audit and the locations and extent of participation of other persons not employed by the auditor that took part in the audit. The comment period initially ended on February 3, 2014, but was subsequently extended to March 17, 2014. This commentary summarizes the contributors' views on these amendments.

Data Availability: The exposure drafts of the proposed and reproposed rules and related information are available at: http://pcaobus.org/Rules/Rulemaking/Pages/Docket029.aspx
The Reliance of External Auditors on Internal Audit's Use of Continuous Audit
Authors: Malaescu Irina , Sutton Steve G.
Published: August 2014

As a response to the increased demand for timely and ongoing assurance over the effectiveness of risk management and control systems, companies are moving toward a more automated control environment through the implementation of continuous audit modules. The purpose of this study is to evaluate external auditors' reliance on internal audit's work when advanced audit techniques are introduced by the internal auditor and the impact this reliance has on budgeted audit hours. Prior literature suggests that internal control deficiencies also have an impact on external auditor reliance and the audit budget. The reliance decision of an external auditor has important economic consequences and implications for efficiency and effectiveness of the overall audit. In recent years, the PCAOB has encouraged greater such reliance to improve audit efficiency. An experiment is conducted with 87 experienced external auditors to investigate the theorized effects. Using a 2 × 2 between-subjects factorial design, the frequency of the internal audit (traditional versus continuous audit) and prior year material weakness (absent versus present) are manipulated. Consistent with predictions, we find that auditors are willing to rely more on internal audit work in a continuous audit environment than in a traditional environment, and this effect is magnified when the prior year audit report on the effectiveness of internal controls indicates that controls are working properly. The presence of a material weakness, however, negatively impacts judgments on the budget for the valuation of a complex account. In addition, both material weakness and continuous audit have an impact on the overall audit budget, which is reduced only when the company has no prior year material weakness and a functioning continuous audit module is put in place. The results show that auditors increase budgeted hours for the engagement at a higher rate when the client uses traditional internal audit procedures.
On the Association between Donor-Imposed Financial Inflexibility and Future Donations to Charitable Organizations
Authors: Surysekar Krishnamurthy , Turner Elizabeth H. , Wheatley Clark M.
Published: August 2014

We address the impact of financial flexibility on organizational performance in a not-for-profit (NFP) setting. Specifically, we examine the link between donor-imposed financial inflexibility and subsequent donations. Donors sometimes impose restrictions on NFP use of the donated resources. These restrictions arise because of donors' preferences regarding how the assets are used, or as a mechanism for donors to monitor the actions of NFP management. Restricted donations cause financial inflexibility and limit managerial discretion. We examine the costs and benefits of restricting managerial discretion and find a negative relation between future donations and high levels of donor restriction. Specifically, we empirically demonstrate that when restricted assets comprise a high percentage of total assets, additional increases in restricted assets are associated with an overall reduction in future donations.
Hydraulic Device for Simulation of Pressure Shocks
Authors: Lindák Stanislav , Majdan Radoslav , Janoško Ivan , Pap Miroslav , Szabó Mário
Published: August 2014

This work is focused on the design of a hydraulic device on which simulations of pressure shocks can be performed. The hydraulic device was constructed to allow simulations of pressure shocks transferred directly in operating conditions because simulation programs for hydraulic accumulators have only theoretical values while simulation on the designed hydraulic device enables obtaining specific readings directly in operating conditions that can be set. At the first control measurement on the hydraulic device, there occurred pressure shocks generated by the hydraulic device itself, these pressure shocks being undesirable in hydraulic circuits. In order to eliminate pressure shocks in the circuit, a diaphragm accumulator was added to the hydraulic device and was used to verify the function of simulating pressure shocks and eliminating undesirable pressure shocks. During the second control measurement on the hydraulic device, a reduction of unwanted pressure shocks was shown with the help of added diaphragm accumulator, thus the function of the hydraulic device to simulate pressure shocks was confirmed, which may also refect practical application in hydraulic circuits of mobile machines.
Corrosion Resistance of Zinc Coatings With Aluminium Additive
Authors: Votava Jiří
Published: August 2014

This paper is focused on evaluation of anticorrosion protection of inorganic metal coatings such as hot-dipped zinc and zinc-galvanized coatings. The thickness and weight of coatings were tested. Further, the evaluation of ductile characteristics in compliance with the norm ČSN EN ISO 20482 was processed. Based on the scratch tests, there was evaluated undercorrosion in the area of artificially made cut. Corrosion resistance was evaluated in compliance with the norm ČSN EN ISO 9227 (salt-spray test). Based on the results of the anticorrosion test, there can be stated corrosion resistance of each individual protective coating. Tests were processed under laboratory conditions and may vary from tests processed under conditions of normal atmosphere.
Gravimetric analysis of selecteD types of Biofuels
Authors: Mikulová Zuzana , Vitázek Ivan , Klúčik Janko
Published: August 2014

Biomass provides a great diversity of input materials and universal use, not only for heat generation but also electricity generation in modern incinerators. For the most eficient use of solid biofuels, it is necessary to know their physico-chemical properties. The work focuses on the gravimetric analysis of selected types of biofuels. This paper presents the results of measurements for moisture content, ash and combustibles in selected solid biofuels. Experiments represent a follow-up to measurements performed to date.
The predictors of falls in adult and senior women from cities of Lower Silesia, Poland
Authors: Domaradzki Jarosław , Ignasiak Zofia , Stodółka Weronika
Published: August 2014

Purpose

balance disorders are considered a significant problem in the elderly as they are associated with an increased incidence of falls. In effect, they can lead to numerous injuries, disability, or even death. The aim of this study was to explore the relationships between the risk of falling and various factors (morphology, socioeconomic status, physical fitness, and physical activity level) in adult and elderly women.

Methods

The study population sample included 149 women aged 47-89 years living in the province of Lower Silesia, Poland. The women were divided into two age groups of younger (n =83, xage = 59.09 years) and older (n = 66, χage = 70.77 years) participants. Measures included BMI, marital status, and physical activity, physical fitness, and education levels. Statistical analysis included a chi-squared χ2 test, cluster analysis, logistic regression, and correspondence analysis.

Results

BMI and physical fitness were strongly correlated with falls: the higher the bMI (overweight or obese) and the lower physical fitness, the greater the risk of falling. The remaining variables showed a weak relationship with falling.

Conclusions

The fall risk of women who are overweight or obese or with a low physical fitness level is approximately 2.5 times higher than those with normal and healthy levels of BMI and physical fitness. The presence of both risk factors increased the likelihood of falling.
Simulation of Moving Loads in Elastic Multibody Systems With Parametric Model Reduction Techniques
Authors: Fischer Michael , Eberhard Peter
Published: August 2014

In elastic multibody systems, one considers large nonlinear rigid body motion and small elastic deformations. In a rising number of applications, e.g. automotive engineering, turning and milling processes, the position of acting forces on the elastic body varies. The necessary model order reduction to enable efficient simulations requires the determination of ansatz functions, which depend on the moving force position. For a large number of possible interaction points, the size of the reduced system would increase drastically in the classical Component Mode Synthesis framework. If many nodes are potentially loaded, or the contact area is not known a-priori and only a small number of nodes is loaded simultaneously, the system is described in this contribution with the parameter-dependent force position. This enables the application of parametric model order reduction methods. Here, two techniques based on matrix interpolation are described which transform individually reduced systems and allow the interpolation of the reduced system matrices to determine reduced systems for any force position. The online-offline decomposition and description of the force distribution onto the reduced elastic body are presented in this contribution. The proposed framework enables the simulation of elastic multibody systems with moving loads efficiently because it solely depends on the size of the reduced system. Results in frequency and time domain for the simulation of a thin-walled cylinder with a moving load illustrate the applicability of the proposed method.
Helicopter Rotor Sailing by Non-Smooth Dynamics Co-Simulation
Authors: Fancello Matteo , Morandini Marco , Masarati Pierangelo
Published: August 2014

This paper presents the application of a co-simulation approach for the simulation of frictional contact in general-purpose multibody dynamics to a rotorcraft dynamics problem. The proposed approach is based on the co-simulation of a main problem, which is described and solved as a set of differential algebraic equations, with a subproblem that is characterized by nonsmooth dynamics events and solved using a timestepping technique. The implementation and validation of the formulation is presented. The method is applied to the analysis of the droop and anti-flap contacts of helicopter rotor blades. Simulations focusing on the problem of blade sailing are conducted to understand the behavior and assess the validity of the method. For this purpose, the results obtained using a contact model based on Hertzian reaction forces at the interface are compared with those of the proposed approach.
Tracking Control of A Balancing Robot – A Model-Based Approach
Authors: Zaiczek Tobias , Franke Matthias
Published: August 2014

This paper presents a control concept for a single-axle mobile robot moving on the horizontal plane. A mathematical model of the nonholonomic mechanical system is derived using Hamel's equations of motion. Subsequently, a concept for a tracking controller is described in detail. This controller keeps the mobile robot on a given reference trajectory while maintaining it in an upright position. The control objective is reached by a cascade control structure. By an appropriate input transformation, we are able to utilize an input-output linearization of a subsystem. For the remaining dynamics a linear set-point control law is presented. Finally, the performance of the implemented control law is illustrated by simulation results.
Modal Measurements and Model Corrections of A Large Stroke Compliant Mechanism
Authors: Wijma W. , Boer S.E. , Aarts R.G.K.M. , Brouwer D.M. , Hakvoort W.B.J.
Published: August 2014

In modelling flexure based mechanisms, generally flexures are modelled perfectly aligned and nominal values are assumed for the dimensions. To test the validity of these assumptions for a two Degrees Of Freedom (DOF) large stroke compliant mechanism, eigenfrequency and mode shape measurements are compared to results obtained with a flexible multibody model. The mechanism consists of eleven cross flexures and seven interconnecting bodies. From the measurements 30% lower eigenfrequencies are observed than those obtained with the model. With a simplified model, it is demonstrated that these differences can be attributed to wrongly assumed leaf spring thickness and misalignment of the leaf springs in the cross flexures. These manufacturing tolerances thus significantly affect the behaviour of the two DOF mechanism, even though it was designed using the exact constraint design principle. This design principle avoids overconstraints to limit internal stresses due to manufacturing tolerances, yet this paper shows clearly that manufacturing imperfections can still result in significantly different dynamic behaviour.
Implementation of A Geometric Constraint Regularization For Multibody System Models
Authors: Müller Andreas
Published: August 2014

Redundant constraints in MBS models severely deteriorate the computational performance and accuracy of any numerical MBS dynamics simulation method. Classically this problem has been addressed by means of numerical decompositions of the constraint Jacobian within numerical integration steps. Such decompositions are computationally expensive. In this paper an elimination method is discussed that only requires a single numerical decomposition within the model preprocessing step rather than during the time integration. It is based on the determination of motion spaces making use of Lie group concepts. The method is able to reduce the set of loop constraints for a large class of technical systems. In any case it always retains a sufficient number of constraints. It is derived for single kinematic loops.
Development of a Professional Services Management Training Program
Authors: Tupper Lee L. , Bausman Dennis , Chowdhury Mashrur , Bhavsar Parth
Published: August 2014

The lack of training programs in systems that allow insufficient references in departments of transportation (DOTs) can create a procurement and administration process that is inefficient, inconsistent, and ineffective. Public agency activities related to contracts must be efficient, fair, and consistent to maintain compliance with state and federal policies. The South Carolina DOT identified a need to develop a comprehensive training program for professional service contract managers to support consistent and efficient execution of department contracts. The objectives of this study were to develop a training program for South Carolina DOT professional services contract managers and to evaluate the training program for statewide adoption. The study resulted in the development of a comprehensive training program to ensure that current and future South Carolina DOT contract managers across the department procure and administer professional services contracts with consistency and effectiveness. Lessons learned and issues identified during development of the training program by an external research team, with oversight by a South Carolina DOT steering committee, are discussed. The training was implemented with South Carolina DOT contract managers in a pilot training session that included contract managers and their supervisors. This paper's presentation of the training program's development process and unique experiences can be applied to other state DOTs to support the improvement of their procurement and administrative processes.
A Clinical and Histopathological study of Lichenoid Eruption of Skin in Two Tertiary Care Hospitals of Dhaka.
Authors: Khaled A , Banu SG , Kamal M , Manzoor J , Nasir TA
Published: August 2014

Abstract not available DOI: http://dx.doi.org/10.3329/pulse.v5i1.20184 Pulse Vol.5 January 2011 p.12-18
Tricuspid Valve Endocarditis in a 50 year male non-IV drug user.
Authors: Hasan Azizul , Munwar Shams , Rahman Muzibur , Rahman Mahfuzur , Marium Anita , Asaduzzaman Md
Published: August 2014

Abstract not available DOI: http://dx.doi.org/10.3329/pulse.v5i1.20190 Pulse Vol.5 January 2011 p.44-49
Miracle Happening In Life: Intra-Abdominal Haemorrhage in Cirrhosis in Pregnancy Managed By Massive Blood Transfusion
Authors: Begum Monowara , Begum Housneara , Rahman Anisur
Published: August 2014

Pregnancy is a rare event in patients with cirrhosis. Recent improvements in the treatment of chronic liver disease have resulted in higher conception rates and more successful pregnancy outcomes. Still pregnancy in cirrhosis is associated with high incidence of fetal loss as well as higher maternal mortality both during pregnancy and in the post-partum period. In this paper we described a case of a successful pregnancy in a young woman with advanced cirrhosis facing life threatening condition in her last trimester and perioperative period. DOI: http://dx.doi.org/10.3329/pulse.v5i1.20191 Pulse Vol.5 January 2011 p.50-53
Teratoma Mimicking Myelolipoma in Adrenal Region
Authors: Agrawal Linika , Khaled Ahmed , Nasir Tareak Al , Zaman Waheed
Published: August 2014

A 19-year-old female presented with backache and left hypochondralgia on and off for one year. Complete blood counts, urinalysis and culture were negative. Ultrasonogram revealed normal kidney and urinary bladder along with a lobulated solid mass at left adrenal region with focal peripheral calcification. Based on the findings, CT scan was advised. CT scan without contrast showed a mass in left adrenal region of approx 3.3x3.2x2.6 cm with punctuate calcification in the wall as well as within the mass. The mass was well encapsulated with predominant fat attenuation interspersed with septae. The left adrenal was not separately identified, hence a presumptive diagnosis of adrenal myelolipoma was considered. The patient underwent left adrenalectomy and the specimen was sent for histopathological examination. Histopathology showed a mass adherent to normal adrenal showing several well differentiated ectodermal structures (tooth, hair follicles, sweat and sebaceous glands etc) consistent with a mature teratoma. The patient recovered uneventfully and is doing well at present. DOI: http://dx.doi.org/10.3329/pulse.v5i1.20192 Pulse Vol.5 January 2011 p.54-56
California Getting Wetter to the North, Drier to the South: Natural Variability or Climate Change?
Authors: Killam Dan , Bui Ann , LaDochy Steve , Ramirez Pedro , Willis Joshua , Patzert William
Published: August 2014

Current climate change projections anticipate that global warming trends will lead to changes in the distribution and intensity of precipitation at a global level. However, few studies have corroborated these model-based results using historical precipitation records at a regional level, especially in our study region, California. In our analyses of 14 long-term precipitation records representing multiple climates throughout the state, we find northern and central regions increasing in precipitation while southern regions are drying. Winter precipitation is increasing in all regions, while other seasons show mixed results. Rain intensity has not changed since the 1920s. While Sacramento shows over 3 more days of rain per year, Los Angeles has almost 4 less days per year in the last century. Both the El Niño-Southern Oscillation (ENSO) and the Pacific Decadal Oscillation (PDO) greatly influence the California precipitation record. The climate change signal in the precipitation records remains unclear as annual variability overwhelms the precipitation trends.
Study on Mixed Working Fluids with Different Compositions in Organic Rankine Cycle (ORC) Systems for Vehicle Diesel Engines
Authors: Yang Kai , Zhang Hongguang , Wang Enhua , Song Songsong , Bei Chen , Chang Ying , Wang Hongjin , Yao Baofeng
Published: August 2014

One way to increase the thermal efficiency of vehicle diesel engines is to recover waste heat by using an organic Rankine cycle (ORC) system. Tests were conducted to study the running performances of diesel engines in the whole operating range. The law of variation of the exhaust energy rate under various engine operating conditions was also analyzed. A diesel engine-ORC combined system was designed, and relevant evaluation indexes proposed. The variation of the running performances of the combined system under various engine operating conditions was investigated. R245fa and R152a were selected as the components of the mixed working fluid. Thereafter, six kinds of mixed working fluids with different compositions were presented. The effects of mixed working fluids with different compositions on the running performances of the combined system were revealed. Results show that the running performances of the combined system can be improved effectively when mass fraction R152a in the mixed working fluid is high and the engine operates with high power. For the mixed working fluid M1 (R245fa/R152a, 0.1/0.9, by mass fraction), the net power output of the combined system reaches the maximum of 34.61 kW. Output energy density of working fluid (OEDWF), waste heat recovery efficiency (WHRE), and engine thermal efficiency increasing ratio (ETEIR) all reach their maximum values at 42.7 kJ/kg, 10.90%, and 11.29%, respectively.
A Rare Case of Aggressive Digital Adenocarcinoma of the Lower Extremity, Masquerading as an Ulcerative Lesion that Clinically Favored Benignancy
Authors: Vazales Ryan , Constant Dustin , Snyder Robert
Published: August 2014

A rare case report of Aggressive Digital Adenocarcinoma (ADPCa) is presented complete with a literature review encompassing lesions that pose potential diagnostic challenges. Similarities between basal cell carcinoma (BCC), marjolin’s ulceration/squamous cell carcinoma (MSCC) and ADPCa are discussed. This article discusses potential treatment options for ADPCa and the need for early biopsy when faced with any challenging lesion. An algorithmic approach to ADPCa treatment based on the most current research is recommended.
Air Quality Modeling in Support of the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS)
Authors: Isakov Vlad , Arunachalam Saravanan , Batterman Stuart , Bereznicki Sarah , Burke Janet , Dionisio Kathie , Garcia Val , Heist David , Perry Steve , Snyder Michelle , Vette Alan
Published: August 2014

A major challenge in traffic-related air pollution exposure studies is the lack of information regarding pollutant exposure characterization. Air quality modeling can provide spatially and temporally varying exposure estimates for examining relationships between traffic-related air pollutants and adverse health outcomes. A hybrid air quality modeling approach was used to estimate exposure to traffic-related air pollutants in support of the Near-Road Exposures and Effects of Urban Air Pollutants Study (NEXUS) conducted in Detroit (Michigan, USA). Model-based exposure metrics, associated with local variations of emissions and meteorology, were estimated using a combination of the American Meteorological Society/Environmental Protection Agency Regulatory Model (AERMOD) and Research LINE-source dispersion model for near-surface releases (RLINE) dispersion models, local emission source information from the National Emissions Inventory, detailed road network locations and traffic activity, and meteorological data from the Detroit City Airport. The regional background contribution was estimated using a combination of the Community Multi-scale Air Quality (CMAQ) and the Space-Time Ordinary Kriging (STOK) models. To capture the near-road pollutant gradients, refined “mini-grids” of model receptors were placed around participant homes. Exposure metrics for CO, NOx, PM2.5 and its components (elemental and organic carbon) were predicted at each home location for multiple time periods including daily and rush hours. The exposure metrics were evaluated for their ability to characterize the spatial and temporal variations of multiple ambient air pollutants compared to measurements across the study area.
Modulation of Selectin-Mediated Adhesion of Flowing Lymphoma and Bone Marrow Cells by Immobilized SDF-1
Authors: Hedges Elizabeth , Hughes Andrew , Liesveld Jane , King Michael
Published: August 2014

The α-chemokine, stromal-derived factor-1 (SDF-1), has been linked to the homing of circulating tumor cells to bone. SDF-1 is expressed by bone microvascular cells and osteoblasts and normally functions to attract blood-borne hematopoietic stem and progenitor cells to marrow. It has been shown that treatment of cancer cells with soluble SDF-1 results in a more aggressive phenotype; however, the relevance of the administration of the soluble protein is unclear. As such, a flow device was functionalized with P-selectin and SDF-1 to mimic the bone marrow microvasculature and the initial steps of cell adhesion. The introduction of SDF-1 onto the adhesive surface was found to significantly enhance the adhesion of lymphoma cells, as well as low-density bone marrow cells (LDBMC), both in terms of the number of adherent cells and the strength of cell adhesion. Thus, SDF-1 has a synergistic effect with P-selectin on cancer cell adhesion and may be sufficient to promote preferential metastasis to bone.
The Three Integrated Phases of Left Atrial Macrophysiology and Their Interactions
Authors: Mehrzad Raman , Rajab Mohammad , Spodick David
Published: August 2014

Our understanding of the left atrium is growing, although there are many aspects that are still poorly understood. The left atrium size as an imaging biomarker has been consistently shown to be a powerful predictor of outcomes and of different cardiovascular disorders, such as, but not limited to, atrial fibrillation, congestive heart failure, mitral regurgitation and stroke. Left atrial function has been conventionally divided into three integrated phases: reservoir, conduit and booster-pump. The highly dynamic left atrium and its response to the stretch and secretion of atrial neuropeptides leaves the left atrium far from being a simple transport chamber. The aim of this review is to provide an understanding of the left atrial physiology and its relation to disorders within the heart.
Applying Metabolomics to Understand the Aggressive Phenotype and Identify Novel Therapeutic Targets in Glioblastoma
Authors: Ahmed Kamran , Chinnaiyan Prakash
Published: August 2014

Glioblastoma continues to be an invariably fatal malignancy. The established approach for understanding the biology of these aggressive tumors in an effort to identify novel molecular targets has largely been genotype-based. Unfortunately, clinical gains offered by this level of understanding have been limited, largely based on the complex nature of signaling networks associated with tumorigenesis and the inability to delineate the key “functional” signaling pathways actually driving growth in an individual tumor. Metabolomics is the global quantitative assessment of endogenous metabolites within a biological system, taking into account genetic regulation, altered kinetic activity of enzymes, and changes in metabolic reactions. Thus, compared to genomics and proteomics, metabolomics reflects changes in phenotype and therefore function. In this review, we highlight some of the key advancements that have been made in applying metabolomics to understand the aggressive phenotype of glioblastoma. Collectively, these studies have provided a previously unrecognized window into the underlying biology of these tumors. Current and future efforts are designed to determine how this technology may be applied to improve diagnosis and predict the aggressiveness of glioblastoma, and more importantly, identify novel, therapeutic strategies designed to improve clinical outcomes.