bluuebunny/crossref_metadata_2025 huggingface dataset:
The population demography of Betula maximowicziana, a cool‐temperate tree species in Japan, in relation to the last glacial period: its admixture‐like genetic structure is the result of simple population splitting not admixing
Authors: Tsuda Y. , Nakao K. , Ide Y. , Tsumura Y.
Published: February 2015

Conservation of the local genetic variation and evolutionary integrity of economically and ecologically important trees is a key aspect of studies involving forest genetics, and a population demographic history of the target species provides valuable information for this purpose. Here, the genetic structure of 48 populations of Betula maximowicziana was assessed using 12 expressed sequence tag–simple sequence repeat (EST‐SSR) markers. Genetic diversity was lower in northern populations than southern ones and structure analysis revealed three groups: northern and southern clusters and an admixed group. Eleven more genomic‐SSR loci were added and the demographic history of these three groups was inferred by approximate Bayesian computation (ABC). The ABC revealed that a simple split scenario was much more likely than isolation with admixture, suggesting that the admixture‐like structure detected in this species was due to ancestral polymorphisms. The ABC analysis suggested that the population growth and divergence of the three groups occurred 96 800 (95% CI, 20 500–599 000) and 28 300 (95% CI, 8700–98 400) years ago, respectively. We need to be aware of several sources of uncertainty in the inference such as assumptions about the generation time, overlapping of generations, confidence intervals of the estimated parameters and the assumed model in the ABC. However, the results of the ABC together with the model‐based maps of reconstructed past species distribution and palaeoecological data suggested that the modern genetic structure of B. maximowicziana originated prior to the last glacial maximum (LGM) and that some populations survived in the northern range even during the LGM.
IV. REACTIVITY AND SLEEP IN INFANTS: A LONGITUDINAL OBJECTIVE ASSESSMENT
Authors: De Marcas Gali S. , Soffer‐Dudek Nirit , Dollberg Shaul , Bar‐Haim Yair , Sadeh Avi
Published: February 2015

Sleep patterns and temperament in the first year of life are closely related. However, research utilizing objective, rather than subjective measurements of sleep and temperament is scarce and results are inconsistent. In addition, a relative lack of longitudinal data prevents inference of causality between the two constructs. In this study, infant sleep was objectively assessed among 95 infants at 3, 6, and 12 months‐of‐age with an actigraph in the home setting. Reactivity to sound, light, and touch, a specific aspect of temperament, was behaviorally assessed at 3 and 6 months, both during sleep (at home) and during waking (at the laboratory). Expected maturational trends were recorded in sleep, with a temporal increase in sleep efficiency and percent of motionless sleep. Quadratic (i.e., inverse U shape) relations were found, especially among girls, when predicting change in sleep by reactivity thresholds, suggesting that both hyposensitive and hypersensitive infants are at risk for poor sleep quality. These are the first research findings suggesting that low reactivity in infancy might be associated with compromised sleep quality. The observed nonlinear effects may account for null or inconsistent results in previous studies that explored only linear associations between temperament and sleep. Future studies should address both extremes of the temperament continuum when exploring relations with sleep patterns.
VII. INFANT SLEEP DEVELOPMENT FROM 3 TO 6 MONTHS POSTPARTUM: LINKS WITH MATERNAL SLEEP AND PATERNAL INVOLVEMENT
Authors: Tikotzky Liat , Sadeh Avi , Volkovich Ella , Manber Rachel , Meiri Gal , Shahar Golan
Published: February 2015

The aims of this longitudinal study were to examine (a) development of infant sleep and maternal sleep from 3 to 6 months postpartum; (b) concomitant and prospective links between maternal sleep and infant sleep; and (c) triadic links between paternal involvement in infant caregiving and maternal and infant sleep. The study included 57 families that were recruited during pregnancy. Maternal and infant sleep was assessed using actigraphy and sleep diaries for 5 nights. Both fathers and mothers completed a questionnaire assessing the involvement of fathers relative to mothers in infant caregiving. The results demonstrated moderate improvement in infant and maternal sleep percent between 3 and 6 months. Maternal sleep percent at 3 months significantly predicted infant sleep percent at 6 months. Greater paternal involvement in infant daytime and nighttime caregiving at 3 months significantly predicted more consolidated maternal and infant sleep at 6 months. These findings suggest that maternal sleep is an important predictor of infant sleep and that increased involvement of fathers in infant caregiving responsibilities may contribute to improvements in both maternal and infant sleep during the first 6 months postpartum.
ORGANIZED CRIMES AGAINST NATURE: ELEPHANTS IN SOUTHERN AFRICA
Authors: LOPES ADRIAN A.
Published: February 2015

Poaching of elephants in Southern Africa is now dominated by international groups following a model of organized crime. This shift, from poaching conducted by small, local groups; with limited mobility, weapons, and technology, to individuals who organize, finance, equip, and transport well‐armed poaching units to previously scouted locations, has made the protection of elephants in Southern Africa much more difficult and dangerous. This paper develops a model of high‐tech criminal poaching. A poaching organization makes a decision on the number of “planned poaching expeditions.” If a poaching unit is intercepted the entire organization is destroyed, but is replaced by a new organization in the next year. The operating life of a poaching organization is a stochastic process, which in turn induces a stochastic evolution in the elephant population. Under plausible conditions, the number of planned poaching expeditions is highly sensitive to the probability of interception by anti‐poaching patrols, but is nonresponsive to reductions in the black‐market ivory price. Thereby it might be better to focus conservation efforts on increasing the probability of intercepting poaching units rather than trying to control black market ivory prices. A benchmark value of poaching expeditions is identified—above which elephants may slowly decline to extinction.
Simulation Evidence on Theory‐based and Statistical Identification under Volatility Breaks
Authors: Herwartz Helmut , Plödt Martin
Published: February 2015

Beside a priori theoretical assumptions on instantaneous or long‐run effects of structural shocks, sign restrictions have become a prominent means for structural vector autoregressive (SVAR) analysis. Moreover, changes in second order moments of systems of time series can be fruitfully exploited for identification purposes in SVARs. By means of Monte Carlo studies, we examine to what degree theory‐based and statistical identification approaches offer an accurate quantification of the true structural relations in a standard model for monetary policy analysis. Subsequently, we discuss how identifying information from theory‐based and statistical approaches can be combined on the basis of a low‐dimensional empirical model of US monetary policy.
Non‐adherence in children with asthma reviewed: The need for improvement of asthma care and medical education
Authors: Klok Ted , Kaptein Adrian A. , Brand Paul L. P.
Published: February 2015

Adherence to daily inhaled corticosteroid therapy is a key determinant of asthma control. Therefore, improving adherence to inhaled corticosteroids is the most effective method through which healthcare providers can help children with uncontrolled asthma. However, identifying non‐adherent patients is difficult, and electronic monitoring is the only reliable method to assess adherence. (Non‐)adherence is a complex behavioural process influenced by many interacting factors. Intentional barriers to adherence are common; driven by illness perceptions and medication beliefs, patients and parents deliberately choose not to follow the doctor's recommendations. Common non‐intentional barriers are related to family routines, child‐raising issues, and to social issues such as poverty. Effective interventions improving adherence are complex, because they take intentional and non‐intentional barriers to adherence into account. There is evidence that comprehensive, guideline‐based asthma self‐management programmes can be successful, with excellent adherence and good asthma control. Patient‐centred care focused on healthcare provider–patient/parent collaboration is the key factor determining the success of guided self‐management programmes. Such care should focus on shared decision‐making as this has been shown to improve adherence and healthcare outcomes. Current asthma care falls short because many physicians fail to adhere to asthma guidelines in their diagnostic approach and therapeutic prescriptions, and because of the lack of application of patient‐centred health care. Increased awareness of the importance of patient‐centred communication and increased training in patient‐centred communication skills of undergraduates and experienced attending physicians are needed to improve adherence to daily controller therapy and asthma control in children with asthma.
Gas induction for pyloromyotomy
Authors: Scrimgeour Gemma E. , Leather Nicholas W.F. , Perry Rachel S. , Pappachan John V. , Baldock Andrew J.
Published: February 2015

Background

Infants with pyloric stenosis are considered to be at high risk of aspiration on induction of anesthesia. Traditionally, texts have recommended classic rapid sequence induction (RSI) or awake intubation (AI). AI has generally fallen out of favor, while the components of RSI have become increasingly controversial. Infants are at high risk of hypoxemia if ventilation is not maintained while waiting for neuromuscular blockade to establish. The efficacy of cricoid pressure (CP) to prevent aspiration has not been proven. It can impair visualization of the glottis and make intubation difficult. It is debatable whether any RSI technique is needed for pyloromyotomy. A recent review of 235 infants reported no aspiration events. These children were anesthetized with a variety of techniques, including RSI, gas induction, and AI. In our institution, we teach a gaseous induction. The nasogastric tube is used to empty the stomach and anesthesia is induced with sevoflurane. A nondepolarizing muscle relaxant is administered and ventilation maintained until neuromuscular blockade is established and intubating conditions are optimal. We report our experience of this technique.

Method

A retrospective medical notes review of all patients undergoing pyloromyotomy between 2005 and 2012.

Results

There were 269 patients (84.4% male, mean weight 3.74 kg ± 0.74). Two hundred and fifty‐two (93.7%) received gas inductions and 17 (6.3%) intravenous (IV) inductions. Two children received an RSI. No patient‐specific factors were identified to explain operator choice in those receiving IV inductions. There were no recorded aspiration events.

Conclusion

Gas induction can be considered for children undergoing pyloromyotomy.
An Algorithm for Automated Estimation of Road Roughness from Mobile Laser Scanning Data
Authors: Kumar Pankaj , Lewis Paul , McElhinney Conor P. , Rahman Alias Abdul
Published: February 2015

Road roughness is the deviation of a road surface from a designed surface grade that influences safety conditions for road users. Mobile laser scanning (MLS) systems provide a rapid, continuous and cost‐effective way of collecting highly accurate and dense 3D point‐cloud data along a route corridor. In this paper an algorithm for the automated estimation of road roughness from MLS data is presented, where a surface grid is fitted to the lidar points associated with the road surface. The elevation difference between the lidar points and their surface grid equivalents provides residual values in height which can be used to estimate roughness along the road surface. Tests validated the new road‐roughness algorithm by successfully estimating surface conditions on multiple road sections. These findings contribute to a more comprehensive approach to surveying road networks.
Aquagrams of Raw Milk for Oestrus Detection in Dairy Cows
Authors: Takemura G , Bázár G , Ikuta K , Yamaguchi E , Ishikawa S , Furukawa A , Kubota Y , Kovács Z , Tsenkova R
Published: February 2015

Contents

The purpose of this research was to develop rapid and cost‐effective method for oestrus detection in dairy cows by means of near infrared spectroscopy and aquaphotomics, using raw milk from individual cows. We found that aquaphotomics approach showed consistent specific water spectral pattern of milk at the oestrus periods of the investigated Holstein cows. Characteristic changes were detected especially in foremilk collected at morning milking. They were reflected in calculated aquagrams of milk spectra where distinctive spectral pattern of oestrus showed increased light absorbance of strongly hydrogen‐bonded water. Results showed that monitoring of raw milk near infrared spectra provides an opportunity for analysing hormone levels indirectly, through the changes of water spectral pattern caused by complex physiological changes related to fertile periods.
Clinical features and survival of lung cancer patients with pleural effusions
Authors: Porcel Jose M. , Gasol Ariadna , Bielsa Silvia , Civit Carme , Light Richard W. , Salud Antonieta
Published: February 2015

Background and objective

The clinical relevance of pleural effusions in lung cancer has seldom been approached systematically. The aim of this study was to determine the prevalence, causes and natural history of lung cancer‐associated pleural effusions, as well as their influence on survival.

Methods

Retrospective review of clinical records and imaging of 556 consecutive patients with a newly diagnosed lung cancer over a 4‐year period at our institution.

Results

Lung cancer comprised 490 non‐small cell and 66 small cell types. About 40% of patients with lung cancer developed pleural effusions at some time during the course of their disease. In half the patients, the effusions were too small to be tapped. These effusions did not progress to require a pleural intervention. Patients with minimal effusions had a worse prognosis compared to patients without pleural effusions (median survival of 7.49 vs 12.65 months, P < 0.001). Less than 20% of the 113 patients subjected to a diagnostic thoracentesis had benign causes for their effusions. Palliative pleural procedures (like therapeutic thoracenteses, pleurodesis or tunnelled pleural catheters) were conducted in 79 (84%) of the 94 malignant effusions. An effusion's size equal to or greater than half of the hemithorax was a strong predictor of the need for a palliative procedure. Overall survival of patients with malignant effusions was 5.49 months.

Conclusions

Malignant pleural effusions are a poor prognostic factor in the setting of lung cancer, which includes minimal effusions not amenable to tapping.
Foreign Direct Investment into Open and Closed Cities
Authors: Dascher Kristof
Published: February 2015

This article argues that the more open a city is to immigration, the more likely it is to welcome – and hence also receive – foreign direct investment (FDI). If immigration is allowed to complement the inflow of foreign capital, urban rent rises by more. This extra rise in rent aids in appeasing owners of capital specific to local traditional industries who else become worse off as FDI flows in. The article's model may help give a simple alternative explanation of why urban centers such as Hong Kong, Singapore, Dublin or many cities on China's Eastern coast have received so much more FDI per capita. These cities could draw on a nearby pool of extra labor that – by driving rents up and keeping wages down – may have been decisive in the political struggle over whether to let foreign direct investors in.
A method to discriminate between closely related bovine major histocompatibility complex class I alleles by combining established PCR‐SSP assays with RFLPs
Authors: Svitek N. , Nzau B. , Steinaa L. , Nene V.
Published: February 2015

We have developed a polymerase chain reaction‐sequence‐specific primers‐restriction fragment length polymorphism (PCR‐SSP‐RFLP) method to rapidly differentiate between the A18 and A18 variant (v) BoLA haplotypes and between A14 and A15/A15v BoLA haplotypes in Holstein/Friesian cattle. We used published SSP to PCR amplify BoLA alleles expressed in animals of known haplotype and exposed the amplicons to the restriction enzyme PvuII that was predicted to cut at a unique site in the middle of BoLA‐6*01302 (A18v) and BoLA‐1*00901 (A15) but not in BoLA‐6*01301 (A18) or BoLA‐1*02301 (A14) alleles. Whereas the method does not discriminate between the A15 and A15v haplotypes, as the BoLA‐1*00902 allele associated with A15v also contains a PvuII site, we are interested in cattle of A18 and A14 haplotype for vaccine related studies. Our results also indicated that the BoLA‐6*01302 (A18v) allele is much more abundant than BoLA‐6*01301 (A18) in the cattle that we sampled.
Community effectiveness of copepods for dengue vector control: systematic review
Authors: Lazaro A. , Han W. W. , Manrique‐Saide P. , George L. , Velayudhan R. , Toledo J. , Runge Ranzinger S. , Horstick O.
Published: February 2015

Objective

Vector control remains the only available method for primary prevention of dengue. Several interventions exist for dengue vector control, with limited evidence of their efficacy and community effectiveness. This systematic review compiles and analyses the existing global evidence for community effectiveness of copepods for dengue vector control.

Methods

The systematic review follows the PRISMA statement, searching six relevant databases. Applying all inclusion and exclusion criteria, 11 articles were included.

Results

There is evidence that cyclopoid copepods (Mesocyclops spp.) could potentially be an effective vector control option, as shown in five community effectiveness studies in Vietnam. This includes long‐term effectiveness for larval and adult control of Ae. aegypti, as well as dengue incidence. However, this success has so far not been replicated elsewhere (six studies, three community effectiveness studies – Costa Rica, Mexico and USA, and three studies analysing both efficacy and community effectiveness – Honduras, Laos and USA), probably due to community participation, environmental and/or biological factors. Judging by the quality of existing studies, there is a lack of good study design, data quality and appropriate statistics.

Conclusion

There is limited evidence for the use of cyclopoid copepods as a single intervention. There are very few studies, and more are needed in other communities and environments. Clear best practice guidelines for the methodology of entomological studies should be developed.
Knowledge and practice of primary eye care among primary healthcare workers in northern Nigeria
Authors: AbdulRahman Aminatu Ali , Rabiu Mansur Muhammad , Alhassan Mahmoud Babanini
Published: February 2015

Objective

To assess knowledge and practice of primary eye care among primary healthcare workers known as community health extension workers in Funtua district of Nigeria.

Methods

Cross‐sectional mixed method study among health workers employed in government‐owned primary healthcare facilities. Quantitative data were obtained using self‐administered questionnaires and checklists, while qualitative data by modified Delphi technique, role plays and observation. A score of 1 was given for each correct answer, while a total score of ≥60% was considered ‘good’.

Results

Eighty three of 88 health workers participated (94%) in the questionnaire survey; while 16 of them were selected for the qualitative survey. Good scores regarding the knowledge of common eye diseases were obtained by 68.7%, but only 26.4% of them could identify their most important features. Participants could undertake 3 of 5 steps in visual acuity testing. Skills in recognising common eye diseases and their management were weak; while practice was often not according to the guidelines.

Conclusion

Community health extension workers displayed good knowledge of common eye diseases. Areas of weakness are recognition and interpretation of eye signs, and practice rarely follows the guidelines. Preventive medicine was neglected; community health extension workers require practical retraining and supervision to achieve integration of primary eye care into primary healthcare services.
CGR2 and CGR3 have critical overlapping roles in pectin methylesterification and plant growth in Arabidopsis thaliana
Authors: Kim Sang‐Jin , Held Michael A. , Zemelis Starla , Wilkerson Curtis , Brandizzi Federica
Published: February 2015

Pectins are critical polysaccharides of the cell wall that are involved in key aspects of a plant's life, including cell‐wall stiffness, cell‐to‐cell adhesion, and mechanical strength. Pectins undergo methylesterification, which affects their cellular roles. Pectin methyltransferases are believed to methylesterify pectins in the Golgi, but little is known about their identity. To date, there is only circumstantial evidence to support a role for QUASIMODO2 (QUA2)‐like proteins and an unrelated plant‐specific protein, cotton Golgi‐related 3 (CGR3), in pectin methylesterification. To add to the knowledge of pectin biosynthesis, here we characterized a close homolog of CGR3, named CGR2, and evaluated the effect of loss‐of‐function mutants and over‐expression lines of CGR2 and CGR3 in planta. Our results show that, similar to CGR3, CGR2 is a Golgi protein whose enzyme active site is located in the Golgi lumen where pectin methylesterification occurs. Through phenotypical analyses, we also established that simultaneous loss of CGR2 and CGR3 causes severe defects in plant growth and development, supporting critical but overlapping functional roles of these proteins. Qualitative and quantitative cell‐wall analytical assays of the double knockout mutant demonstrated reduced levels of pectin methylesterification, coupled with decreased microsomal pectin methyltransferase activity. Conversely, CGR2 and CGR3 over‐expression lines have markedly opposite phenotypes to the double knockout mutant, with increased cell‐wall methylesterification levels and microsomal pectin methyltransferase activity. Based on these findings, we propose that CGR2 and CGR3 are critical proteins in plant growth and development that act redundantly in pectin methylesterification in the Golgi apparatus.
Dynamic regulation of photosynthesis in Chlamydomonas reinhardtii
Authors: Minagawa Jun , Tokutsu Ryutaro
Published: February 2015

Plants and algae have acquired the ability to acclimatize to ever‐changing environments to survive. During photosynthesis, light energy is converted by several membrane protein supercomplexes into electrochemical energy, which is eventually used to assimilate CO2. The efficiency of photosynthesis is modulated by many environmental factors, including temperature, drought, CO2 concentration, and the quality and quantity of light. Recently, our understanding of such regulators of photosynthesis and the underlying molecular mechanisms has increased considerably. The photosynthetic supercomplexes undergo supramolecular reorganizations within a short time after receiving environmental cues. These reorganizations include state transitions that balance the excitation of the two photosystems: qE quenching, which thermally dissipates excess energy at the level of the light‐harvesting antenna, and cyclic electron flow, which supplies the increased ATP demanded by CO2 assimilation and the pH gradient to activate qE quenching. This review focuses on the recent findings regarding the environmental regulation of photosynthesis in model organisms, paying particular attention to the unicellular green alga Chlamydomonas reinhardtii, which offer a glimpse into the dynamic behavior of photosynthetic machinery in nature.
The Relationship Between Communicable Diseases and FDI Flows: An Empirical Investigation
Authors: Ghosh Sucharita , Renna Francesco
Published: February 2015

This paper focuses on the impact of communicable diseases, which affects the population health component of human capital on worldwide FDI flows. The model controls for endogeneity that can stem from the interconnected relationship between FDI, population health and per capita GDP. After controlling for this endogeneity, we find that communicable diseases have a statistically significant negative effect on FDI, which is 2 to 5 times larger than when using ordinary least squares. The results remain robust to alternative model specifications.
Patient characteristics influencing the variability of distributed parameter‐based models in DCE‐CT kinetic analysis
Authors: La Fontaine M. D. , McDaniel L. S. , Kubicek L. N. , Chappell R. J. , Forrest L. J. , Jeraj R.
Published: February 2015

Kinetic parameter variability may be sensitive to kinetic model choice, kinetic model implementation or patient‐specific effects. The purpose of this study was to assess their impact on the variability of dynamic contrast‐enhanced computed tomography (DCE‐CT) kinetic parameters. A total of 11 canine patients with sinonasal tumours received high signal‐to‐noise ratio, test‐double retest DCE‐CT scans. The variability for three distributed parameter (DP)‐based models was assessed by analysis of variance. Mixed‐effects modelling evaluated patient‐specific effects. Inter‐model variability (CVinter) was comparable to or lower than intra‐model variability (CVintra) for blood flow (CVinter:[4–28%], CVintra:[28–31%]), fractional vascular volume (CVinter:[3–17%], CVintra:[16–19%]) and permeability‐surface area product (CVinter:[5–12%], CVintra:[14–15%]). The kinetic models were significantly (P<0.05) impacted by patient characteristics for patient size, area underneath the curve of the artery and of the tumour. In conclusion, DP‐based models demonstrated good agreement with similar differences between models and scans. However, high variability in the kinetic parameters and their sensitivity to patient size may limit certain quantitative applications.
Hypercalcemia and parathyroid hormone‐related peptide expression in a dog with thyroid carcinoma and histiocytic sarcoma
Authors: Scruggs Jennifer L. , Nobrega‐Lee Michelle , Fry Michael M. , Applegate Rory
Published: February 2015

A 9.5‐year‐old, male castrated Walker Hound was presented for evaluation of progressive weakness, anorexia, and weight loss. Imaging revealed multiple abdominal and thoracic masses and ascites; fine‐needle aspirates of mesenteric and splenic masses confirmed malignancy, most likely histiocytic sarcoma. Laboratory analyses revealed increased ionized calcium and parathyroid hormone‐related peptide (PTH‐rP) concentrations, and concurrent low–normal parathyroid hormone concentration, consistent with humoral hypercalcemia of malignancy. Necropsy was performed after euthanasia. The dog had disseminated histiocytic sarcoma, including sarcomatosis, as well as bilateral thyroid carcinoma. PTH‐rP immunostaining was positive in the thyroid carcinoma but negative in the histiocytic neoplasm. These results suggest that thyroid carcinoma‐associated hypercalcemia can be caused by tumor secretion of PTH‐rP.
Review: Role of genetics and the environment in the pathogenesis of canine atopic dermatitis
Authors: Bizikova Petra , Pucheu‐Haston Cherie M. , Eisenschenk Melissa N. C. , Marsella Rosanna , Nuttall Tim , Santoro Domenico
Published: February 2015

Background

Multiple levels of evidence support the role of genetics and the environment in the pathogenesis of canine atopic dermatitis (AD).

Objectives

This review summarizes the current evidence in genetics and the effect of environmental factors on the development and perpetuation of canine AD.

Methods

Citation databases, abstracts and proceedings from international meetings published between 2001 and 2013 were reviewed in this update. Where necessary, older articles were included for background information.

Results

Canine AD is a heritable disease, in which interaction with environmental factors influences disease risk and phenotype. A study of British guide dogs indicated that nearly 50% of the risk of developing AD was determined by an individual's genotype. Genomic studies performed so far in canine AD have uncovered numerous gene candidates likely to be involved in pathogenesis through their role in immunity, skin barrier formation, apoptosis and inflammation. In addition to genetics, there is evidence to suggest that exposure to certain environmental factors influences the prevalence and course of canine AD. For example, living in rural areas or feeding noncommercial diets was negatively associated with the development of AD in dogs, while exposure to high levels of smoke was associated with increased prevalence of allergic skin disease.

Conclusions

It is becoming clear that canine AD is genotypically complex and influenced by a variety of environmental factors. Well‐designed studies with sufficient statistical power will be critical to identify the complex genetic and environmental factors involved in disease development and progression. Recognition of such factors may help to identify new targets for therapy and enable better disease prevention and management.
Effect of 1,8-Diiodooctane on the Performance of P3HT:PCBM Solar Cells
Authors: Nasiri M. , Abbasi F.
Published: February 2015

Effect of 1,8-diiodooctane on the performance of poly(3-hexylthiophene) (P3HT):[6,6]-phenyl-C61-butyric acid methyl ester (PCBM) solar cells with glass/indium tin oxide (ITO)/poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS)/P3HT: PCBM/Ca/Al structure was studied. The morphology and thickness of the active layer were investigated using atomic force microscopy (AFM). The UV-visible spectroscopy and X-ray diffraction (XRD) analysis were used to study the absorption behavior (of the solutions and coated layers) and crystallinity of the active layer, respectively. The results show that the existence of 1,8-diiodooctane reduced the open circuit voltage from 0.81 to 0.52 V and increased the short circuit current by about three folds; the fill factor (FF) and power conversion efficiency were increased from 36.0 to 54.1% and 0.47% to 1.54%, respectively. These changes can be attributed to the enhanced crystallinity of P3HT or the doping effect of 1,8-diiodooctane on P3HT chains. UV-visible analysis demonstrated that the addition of 1,8-diiodooctane to the solution did not change the absorption onset, whereas in the coated layers, the maximum absorption peak shifted to higher wavelengths. The XRD analyses demonstrated the enhancement of crystallinity of P3HT upon the introduction of 1,8-diiodooctane.
Prediction of Two-Phase Heat Transfer Coefficients in a Horizontal Pipe for Different Inclined Positions With Artificial Neural Networks
Authors: Sobhanifar Najmeh , Ahmadloo Ebrahim , Azizi Sadreddin
Published: February 2015

This paper presents the application of artificial neural network (ANN) in prediction of heat transfer coefficients (HTCs) of two-phase flow of air–water in a pipe in the horizontal and slightly upward inclined (2, 5, and 7 deg) positions. For this purpose, the superficial liquid and gas Reynolds numbers and the inclination of the pipe were used as input parameters, while the HTCs of two-phase flow were used as output parameters in training and testing of the multilayered, feedforward, backpropagation neural networks. In this present study, experimental data were taken from literature and then used for the ANN model. The superficial liquid and gas Reynolds numbers ranged from 740 to 26,100 and 560 to 47,600 for water and air, respectively. The mean deviations against experimental data were determined for the model. Results showed that the network predictions were in very good agreement with the experimental HTC data, whereas the correlation showed more deviations. Finally, results showed that the accuracy between the neural network predictions and experimental data was achieved with mean relative error (MRE) of 2.92% and correlation coefficient (R) that was 0.997 for all datasets, which suggests the reliability of the ANNs as a strong tool for predicting HTCs with two-phase flows.
Notes on Steady Natural Convection Heat Transfer by Double Diffusion From a Heated Cylinder Buried in a Saturated Porous Media
Authors: Chaves Carlos Alberto , Lamas Wendell de Queiroz , Nunes Luiz Eduardo Nicolini do Patrocinio , Camargo Jose Rui , Grandinetti Francisco Jose
Published: February 2015

This paper aims to present numerical solutions for the problem of steady natural convection heat transfer by double diffusion from a heated cylinder buried in a saturated porous media exposed to constant uniform temperature and concentration in the cylinder and in the media surface. A square finite domain 3 × 3 and acceptance criterion converged solution with an absolute error under 1 × 10−3 were considered to obtain results presented. The Patankar's power law for approaching of variables calculated T, C, and ϕ also was adopted. In order of method validation, an investigation of mesh points number as function of Ra, Le, and N was done. A finite volume scheme has been used to predict the flow, temperature, and concentration distributions at any space from a heat cylinder buried into a fluid-saturated porous medium for a bipolar coordinates system. Examples presented show that the differences in the flow distribution caused not only when Rayleigh number range is considered but also when Lewis number range is considered. Further, increase in the Rayleigh number has a significant influence in the flow distribution when the concentration distribution is considered. Steady natural convection heat transfer by double diffusion from a heated cylinder buried in a saturated porous medium is studied numerically using the finite volume method. To model fluid flow inside the porous medium, the Darcy equation is used. Numerical results are obtained in the form of streamlines, isotherms, and isoconcentrations. The Rayleigh number values range from 0 to 1000, the Lewis number values range from 0 to 100, and the buoyancy ratio number is equal to zero. Calculated values of average heat transfer rates agree reasonably well with values reported in the literature.
Influences of the Operating Conditions on the Rotordynamic Forces Acting on a Three-Bladed Inducer Under Forced Whirl Motion
Authors: Valentini Dario , Pace Giovanni , Torre Lucio , Pasini Angelo , d’Agostino Luca
Published: February 2015

In the present paper, the results from an extensive experimental characterization of the rotordynamic forces acting on a whirling three-bladed, tapered-hub, variable-pitch inducer are presented. The campaign has been conducted in the Cavitating Pump Rotordynamic Test Facility (CPRTF) at ALTA S.p.A. The forces acting on the impeller have been measured by means of a rotating dynamometer mounted just behind the inducer. The roles of the rotor whirl motion, flow rate, cavitating condition, and liquid temperature have been investigated. The analysis has been conducted by means of the classical rotordynamic approach together with a recent experimental technique, consisting in measuring the rotordynamic forces continuous behavior (spectra) as functions of the whirl excitation frequency. This technique allows for evaluating information from experiments more rapidly and accurately with regards to previous methods. Therefore, it is useful to better capture the complexity of the rotordynamic forces and assess their consequences on the stability of axial inducers.
Control and Motion Planning of a Nonholonomic Parallel Orienting Platform
Authors: Jakubiak Janusz , Magiera Władyslaw , Tchoń Krzysztof
Published: February 2015

An orienting platform is a mechanism which allows rotation of a spatial object without translational motion of that object. In this work, we study a parallel platform with one passive nonholonomic spherical joint and two series of spherical, actuated prismatic and universal joints (the platform is also known in literature as an (nS)-2SPU wrist). To solve the control and motion planning problems, an analytic approach is used. The design of practical stabilization and tracking algorithm is based on transverse functions and a method for motion planning respecting mechanical singularities is derived from endogenous configuration space approach. It is shown that the system is controllable and locally equivalent to the chained form system. Then, the stabilization, tracking, and motion planning algorithms are proposed. Results are verified with computer simulations. A combination of the open-loop motion planning algorithm and the closed-loop tracking provide a tool for designing a motion planning algorithm respecting mechanical singularities and robust to input disturbances.
Integrated Decision Making in Electric Vehicle and Charging Station Location Network Design
Authors: Kang Namwoo , Feinberg Fred M. , Papalambros Panos Y.
Published: February 2015

A major barrier in consumer adoption of electric vehicles (EVs) is “range anxiety,” the concern that the vehicle will run out of power at an inopportune time. Range anxiety is caused by the current relatively low electric-only operational range and sparse public charging station (CS) infrastructure. Range anxiety may be significantly mitigated if EV manufacturers and CS operators work in partnership using a cooperative business model to balance EV performance and CS coverage. This model is in contrast to a sequential decision-making model where manufacturers bring new EVs to the market first and CS operators decide on CS deployment given EV specifications and market demand. This paper proposes an integrated decision-making framework to assess profitability of a cooperative business model using a multidisciplinary optimization model that combines marketing, engineering, and operations considerations. This model is demonstrated in a case study involving battery EV design and direct current (DC) fast-CS location network in Southeast Michigan. The expected benefits can motive both government and private enterprise actions.
Effects of Grooving in a Hydrostatic Circular Step Thrust Bearing With Porous Facing
Authors: Mahbubur Razzaque M. , Zakir Hossain M.
Published: February 2015

Effects of grooving in a porous faced hydrostatic circular step thrust bearing are investigated using a mathematical model based on the narrow groove theory (NGT). It is shown that enhancement of load capacity by grooving the step is possible at moderate level of permeability of the porous facing. Load capacity drops sharply with the increase of porous facing thickness. However, this drop in load capacity occurs mostly within a small thickness of the porous facing. Considering the coupled effects of permeability and inertia, it is recommended that the dimensionless step location should be 0.5–0.8 and the dimensionless step height should be less than five to take advantage of grooving. The groove geometric parameters such as groove inclination angle, fraction of grooved area and groove depth corresponding to the maximum load capacity are found to be the same for both with and without porous facing. However, with porous facing, the sensitivity of the load capacity on the groove parameters reduces. At high level of permeability, the effects of grooves may become insignificant because of high seepage flow through the porous facing.
Compressed Air Energy Storage Thermal Performance Improvements
Authors: Gaul G. W. , Cornell T. M. , Nakhamkin M. , Paprotna H.
Published: February 2015

This paper covers the development of Compressed Air Energy Storage (CAES) Systems and the methods used to increase performance and efficiency. It shows the evolution from the original non-recuperated cycle to the current designs, and examines the future possibilities of such cycles as CAES at 2500°F (1370°C), CAES with humidification, CAES integrated with coal gasification, and CAES with chemical recuperation.
Performance Improvement in Industrial Gas Turbines
Authors: Diakunchak Ihor S.
Published: February 2015

This paper describes the importance of maintaining high efficiency in industrial gas turbines used in power generation to reduce the consumption of a non-renewable energy resource and to minimize the harmful effects on our environment. The cost of inefficiency in monetary terms and in the production of harmful emissions is described. The significance of maintaining high component efficiency, especially the prevention of compressor fouling, on the overall engine performance is stressed. The effect of each component performance on engine efficiency is described in some detail. Examples on how component efficiencies can be improved are provided. Recommendations are made for reducing energy consumption by optimized operational procedure and improved engine maintenance.
Drug delivery and cell interaction of adhesive poly(ethyleneimine)/sulfated polysaccharide complex particle films
Authors: Müller Martin , Torger Bernhard , Wehrum Diana , Vehlow David , Urban Birgit , Woltmann Beatrice , Hempel Ute
Published: February 2015

Herein, the authors report and review polyelectrolyte complex (PEC) nanoparticles (NPs) loaded with zoledronate (ZOL) and simvastatin and their effects on bone cells. PEC NPs are intended for modification of bone substitute materials. For characterization, they can be solution casted on germanium (Ge) substrates serving as analytically accessible model substrate. PEC NPs were generated by mixing poly(ethyleneimine) (PEI) either with linear cellulose sulfate (CS) or with branched dextransulfate (DS). Four important requirements for drug loaded PEC NPs and their films are addressed herein, which are the colloidal stability of PEC dispersions (1), interfacial stability (2), cytocompatibility (3), and retarded drug release (4). Dynamic light scattering measurements (DLS) showed that both PEI/CS and PEI/DS PEC NP were obtained with hydrodynamic radii in the range of 35–170 nm and were colloidally stable up to several months. Transmission FTIR spectroscopy evidenced that films of both systems were stable in contact to the release medium up to several days. ZOL-loaded PEI/CS nanoparticles, which were immobilized on an osteoblast-derived extracellular matrix, reduced significantly the resorption and the metabolic activity of human monocyte-derived osteoclasts. FTIR spectroscopy at cast PEC/drug films at Ge substrates revealed retarded drug releases in comparison to the pure drug films.
Comparison between target margins derived from 4DCT scans and real‐time tumor motion tracking: Insights from lung tumor patients treated with robotic radiosurgery
Authors: Descovich Martina , McGuinness Christopher , Kannarunimit Danita , Chen Josephine , Pinnaduwage Dilini , Pouliot Jean , Kased Norbert , Gottschalk Alexander R. , Yom Sue S.
Published: February 2015

Purpose:

A unique capability of the CyberKnife system is dynamic target tracking. However, not all patients are eligible for this approach. Rather, their tumors are tracked statically using the vertebral column for alignment. When using static tracking, the internal target volume (ITV) is delineated on the four‐dimensional (4D) CT scan and an additional margin is added to account for setup uncertainty [planning target volume (PTV)]. Treatment margins are difficult to estimate due to unpredictable variations in tumor motion and respiratory pattern during the course of treatment. The inability to track the target and detect changes in respiratory characteristics might result in geographic misses and local tumor recurrences. The purpose of this study is to develop a method to evaluate the adequacy of ITV‐to‐PTV margins for patients treated in this manner.

Methods:

Data from 24 patients with lesions in the upper lobe (n = 12), middle lobe (n = 3), and lower lobe (n = 9) were included in this study. Each patient was treated with dynamic tracking and underwent 4DCT scanning at the time of simulation. Data including the 3D coordinates of the target over the course of treatment were extracted from the treatment log files and used to determine actual target motion in the superior–inferior (S–I), anterior–posterior (A–P), and left–right (L–R) directions. Different approaches were used to calculate anisotropic and isotropic margins, assuming that the tumor moves as a rigid body. Anisotropic margins were calculated by separating target motion in the three anatomical directions, and a uniform margin was calculated by shifting the gross tumor volume contours in the 3D space and by computing the percentage of overlap with the PTV. The analysis was validated by means of a theoretical formulation.

Results:

The three methods provided consistent results. A uniform margin of 4.5 mm around the ITV was necessary to assure 95% target coverage for 95% of the fractions included in the analysis. In the case of anisotropic margins, the expansion required in the S–I direction was larger (8.1 mm) than those in the L–R (4.9 mm) and A–P (4.5 mm) directions. This margin accounts for variations of target position within the same treatment fraction.

Conclusions:

The use of bony alignment for CyberKnife lung stereotactic body radiation therapy requires careful considerations, in terms of the potential for increased toxicity or local miss. Our method could be used by other centers to determine the adequacy of ITV‐to‐PTV margins for their patients.
Thomas precession and torque
Authors: Rębilas Krzysztof
Published: February 2015

The spin of a gyroscope that undergoes Thomas precession seems to change its direction without any torque, which would mean that conservation of angular momentum is violated. To resolve this paradox, it is shown that the spin dynamics equation describing Thomas precession (the BMT equation) can be written in terms of a torque applied to the spin. A simple method of finding an explicit expression for the torque is presented in the case of a gyroscope performing circular motion. An unexpected oscillatory character of the torque is explained in terms of the difference between the proper spin and the spin observed in the laboratory frame.
Compressed-format compared to regular-format in a first-year university physics course
Authors: Harlow Jason J. B. , Harrison David M. , Honig Eli
Published: February 2015

We compare student performance in two sessions of a large first-year university physics course, one with a normal 12-week term and the other with a compressed 6-week term. Student performance is measured by the normalized gain on the Force Concept Inventory. We find that the gains for the regular-format course are better than the gains for the compressed-format course, and while the differences in gains are small they are statistically significant. Not accounted for are the differences in effectiveness of the different instructors in the two versions of the course.
Age trend of heritability, genetic correlation, and efficiency of early selection for wood quality traits in Scots pine
Authors: Hong Zhou , Fries Anders , Wu Harry X.
Published: February 2015

To examine the efficiency of early selection for wood quality traits in the Scots pine (Pinus sylvestris L.) breeding program in Sweden, a total of 778 wood increment cores were sampled from 179 full-sib families in a single progeny trial at 40 years of age. Age trend of inheritance, age–age genetic correlation, and early selection efficiency for eight wood traits including annual ring width, wood density, microfibril angle (MFA), modulus of elasticity (i.e., wood stiffness; MOE), and fibre dimensions were studied. Heritabilities for the eight wood traits reached a plateau between age 5 years and age 15 years, with the highest heritability for radial fibre width and fibre coarseness (∼0.6) and the lowest heritability for ring width (∼0.2). Heritability reached about 0.4 for both wood density and MFA but only reached about 0.3 for MOE. Genetic correlation from early to reference age 30 years reached a very high level (>0.8) for all eight wood traits at age 5 years. Early selection was effective for wood quality traits in Scots pine, and selection at age 8 years is recommended for MOE in Scots pine.