bluuebunny/crossref_metadata_2025 huggingface dataset:
Fetomaternal hemorrhage in normal vaginal delivery and in delivery by cesarean section
Authors: Lubusky Marek , Simetka Ondrej , Studnickova Martina , Prochazka Martin , Ordeltova Marta , Vomackova Katherine
Published: February 2012

BACKGROUND: The objective was to determine the incidence and volume of fetomaternal hemorrhage (FMH) in normal vaginal delivery and in delivery by cesarean section. Determination of these variables would enable optimalization of guidelines for D alloimmunization prophylaxis.

STUDY DESIGN AND METHODS: In a prospective cohort study, a total of 3457 examinations were performed, 2413 after normal vaginal delivery and 1044 after cesarean delivery. FMH was assessed by flow cytometry. (FMH is fetal red blood cell [RBC] volume; fetal blood volume is double [expected fetal hematocrit is 50%].)

RESULTS: The fetal RBC volume diagnosed in maternal circulation after delivery ranged from insignificant FMH of not more than 0.1 mL to excessive FMH of 65.9 mL (median, 0.7; mean, 0.78; SD, 1.48). FMH of more than 2.5 mL (immunoglobulin [Ig] G anti‐D insufficient dose 50 µg) was observed in 1.4% (49/3457) and excessive volumes of FMH of more than 5 mL (insufficient dose, 100 µg) in 0.29% (10/3457). Delivery by cesarean section presented a higher risk of incidence of FMH of more than 2.5 mL (odds ratio, 2.2; p = 0.004) when compared with normal vaginal delivery. It did not, however, present a significant risk factor for the incidence of excessive volumes of FMH of more than 5 mL.

CONCLUSION: During normal vaginal delivery as well as during delivery by cesarean section, FMH of less than 5 mL occurs in the great majority of cases, and thus for the prevention of D alloimmunization, an IgG anti‐D dose of 100 µg should be sufficient. Contrarily, only rarely does greater FMH occur and delivery by cesarean section does not present a risk factor.
The detection of clinically relevant contact allergens with a standard screening tray of 28 allergens
Authors: Patel Devika , Belsito Donald V.
Published: February 2012

Background. A standard method for diagnosing allergic contact dermatitis in the United States is the Thin‐layer Rapid Use Epicutaneous (TRUE) test (TRUE Test™), which consists of three panels containing 20 individual allergens and eight allergen mixes. Previous studies had raised concern regarding the adequacy of the initial two‐panel TRUE Test™ system (16 individual allergens and seven allergen mixes) in fully assessing patients with possible allergic contact dermatitis.

Objectives. We sought to investigate the effectiveness of the current three‐panel TRUE Test™ as the sole diagnostic tool for detecting allergic contact dermatitis.

Patients/materials/methods. This study was a retrospective analysis of 2088 patients who underwent patch testing between 1995 and 2010. Study groups were analysed to determine whether positive reactions were to allergens and/or mixes present in the TRUE Test™ panels.

Results. Of the 2088 patch‐tested patients, 1385 had at least one positive reaction. Among these 1385 patients, 27.6% were fully evaluated by use of only the TRUE Test™ series, 49.9% were partially evaluated, and 22.5% did not have any of their allergens detected. On assessment for clinical relevance, similar percentages were observed.

Conclusion. In our study, the current TRUE Test™ series of 28 allergens would have completely identified allergens in only 27.6% of patients. Broadening the standard panel to include common allergens causing >50% of allergic contact dermatitis cases in a given geographical location and aim testing allergens on the basis of the patient's history will increase the test's sensitivity.
Cyclosporine‐A inhibits MMP‐2 and ‐9 activities in the presence of Porphyromonas gingivalis lipopolysaccharide: an experiment in human gingival fibroblast and U937 macrophage co‐culture
Authors: Kuo P.‐J. , Tu H.‐P. , Chin Y.‐T. , Lu S.‐H. , Chiang C.‐Y. , Chen R.‐Y. , Fu E.
Published: February 2012

Kuo PJ, Tu HP, Chin YT, Lu SH, Chiang CY, Chen RY, Fu E. Cyclosporine‐A inhibits MMP‐2 and ‐9 activities in the presence of Porphyromonas gingivalis lipopolysaccharide: an experiment in human gingival fibroblast and U937 macrophage co‐culture. J Periodont Res 2012; 47: 431–438. © 2012 John Wiley & Sons A/S

Background and Objective:  Studies have shown that bacterial plaque and the associated gingival inflammation increase the severity of gingival overgrowth induced by cyclosporine‐A (CsA). This in vitro study aimed to evaluate the effect of CsA on the activities of MMPs from the co‐culture of human gingival fibroblasts and U937 macrophages in the presence or absence of Porphyromonas gingivalis lipopolysaccharide (LPS).

Material and Methods:  Activities of pro‐MMP‐2, MMP‐2 and pro‐MMP‐9 in the supernatants of independent cultures and co‐cultures were examined by zymography. RT‐PCR was selected to evaluate the expression of mRNA for membrane type‐1 (MT1) MMP in the co‐cultures.

Results:  Activities of MMPs in the co‐cultures were significantly greater when compared with any of the independent cultures. Lipopolysaccharide significantly increased the MMP activities in a dose‐dependent manner in the co‐cultures, whereas CsA inhibited these activities. In the presence of both CsA and LPS, the MMP activities inhibited by CsA could still be observed in the co‐cultures. In the individual cultures, in contrast, the CsA‐inhibited MMP activities, in the presence of LPS, were minimally detected. The mRNA expression of MT1‐MMP was significantly enhanced after LPS treatment; however, this enhancement was inhibited by CsA.

Conclusion:  This study demonstrated that, in co‐cultures of human gingival fibroblasts and U937 macrophages, CsA could inhibit MMP activities in the presence of P. gingivalis LPS. It might be part of the underlying reason for the persistent overgrowth of gingiva seen when bacterial plaque and local inflammation are present during CsA therapy.
Bilateral striopallidodentate calcinosis presenting with psychiatric symptoms and speech disorders
Authors: Ozdilek Betul , Uluc Kayıhan , Gunal Dilek I.
Published: February 2012

Ozdilek B, Uluc K, Gunal DI. Bilateral striopallidodentate calcinosis presenting with psychiatric symptoms and speech disorders.

Background: Bilateral striopallidodentate calcinosis (BSPDC), also known as Fahr's disease, is a rare neurodegenerative disorder characterised by the deposition of calcium and other minerals in the basal ganglia, centrum semiovale and cerebellum. It is usually idiopathic. Its clinical manifestations vary from asymptomatic individuals to neuropsychiatric abnormalities, movement disorders, cerebellar symptoms and cognitive impairments.

Methods: Five cases of BSPDC – all of which include psychiatric symptoms and speech problems – from two families are documented in this article.

Conclusion: The most important diagnostic marker is the demonstration of symmetrical intracranial calcifications. Computerised tomography of the brain is the most frequently used radiologic method to diagnose BSPDC.
The Formula that Killed Wall Street
Authors: Salmon Felix
Published: February 2012

Wall Street in the mid-1980s turned to the quants – brainy financial engineers – to invent new ways to boost profits. They and their managers, though laziness and greed, built a huge financial bubble on foundations that they did not understand. It was a recipe for disaster. The journalist Felix Salmon won the American Statistical Association's Excellence in Statistical Reporting Award for 2010, We reprint his article, first published as the cover story of Wired magazine, because it brilliantly conveys complex statistical concepts to non-specialists.
The influence of steam cleaning procedures on the surface roughness of commonly used type III dental stone for the fabrication of removable dentures
Authors: Cilingir Altug , Geckili Onur , Parlar Zeynep , Gencel Burc , Bozdag Ergun , Temiz Vedat
Published: February 2012

doi: 10.1111/j.1741‐2358.2012.00669.x

The influence of steam cleaning procedures on the surface roughness of commonly used type III dental stone for the fabrication of removable dentures

Objective:  This study investigated the possible detrimental effects of steam treatment on the surface of type III dental stone, which is a common laboratory material used for the construction of removable dentures.

Material and Methods:  Forty dental stone specimens were prepared and divided into four groups (A, B, C and D), and group A was used as the control group. The other groups were treated with steam from a standard distance for varying durations (30, 60 and 120 s).

Results:  The duration of steam cleaning significantly increased Ra values (F = 63.150, p = 0.000). Similarly, the duration of steam application was directly correlated with the weight changes (F = 17.721, p = 0.000). A significant amount of dental stone can be removed from the surface while treating with steam.

Conclusion:  These studies demonstrated that expanded periods of steam cleaning cause weight loss and abrade the surface of type III dental stones; therefore, these devices should be used with caution during denture fabrication procedures.
Effect of genetic variation in the MHC Class II DRB region on resistance and susceptibility to Johne’s disease in endangered Indian Jamunapari goats
Authors: Singh P. K. , Singh S. V. , Singh M. K. , Saxena V. K. , Horin P. , Singh A. V. , Sohal J. S.
Published: February 2012

The pathogenesis of Johne’s disease (JD), caused by Mycobacterium avium subsp. paratuberculosis (MAP), is complex and has not been completely understood yet. In the present study, we analysed the polymorphism in the exon‐2 of the caprine major histocompatibility complex (MHC) Class II DRB region and its association with resistance or susceptibility to JD. A total of 203 Jamunapari goats, which is an Indian endangered breed highly susceptible to JD, kept at a single farm were studied. On the basis of clinical signs, microscopic examination, faecal culture, ELISA and diagnostic PCR, 60 and 143 goats were classified as resistant and susceptible to JD, respectively. PCR‐based restriction fragment length polymorphism (PCR‐RFLP) with two enzymes, PstI and TaqI, was used to assess variation in the DRB gene(s) in all 203 goats studied. Two di‐allelic single nucleotide polymorphisms (SNPs), here referred as ‘P’ and ‘T’, were tested. In each of them, three genotypes were found in the group analysed. The minimum allele frequencies (MAFs) were 0.233 and 0.486 for the P and T SNPs, respectively. Statistically significant associations between alleles, individual genotypes and composed genotypes of both SNPs were found. The frequency of p and t alleles, of individual pp and tt and of composed pptt genotypes were significantly higher (Pcorr < 0.001) in the ‘resistant’ group as compared to the ‘susceptible’ group, while the P and T alleles were associated with susceptibility (Pcorr < 0.001). In heterozygous genotypes, susceptibility was dominant over resistance. The effects of both SNP on resistance and susceptibility were comparable and composed heterozygous genotypes showed intermediate levels of susceptibility in terms of the odds ratio and P‐values calculated.
Highly Potent Antidiuretic Antagonists: Conformational Studies of Vasopressin Analogues Modified with 1‐Naphthylalanine Enantiomers at Position 2
Authors: Lubecka Emilia A. , Ciarkowski Jerzy , Prahl Adam , Sikorska Emilia
Published: February 2012

In this paper, we investigated the structure–activity relationship of two vasopressin analogues, [Cpa1,(L‐1‐Nal)2]AVP (I) and [Cpa1,(D‐Nal)2]AVP (II) by NMR spectroscopy and molecular modeling. Both peptides exhibit antioxytocic and antipressor potency. Inversion of configuration of the residue at position 2 converted a weak antidiuretic agonist (peptide I) into a highly potent antidiuretic antagonist (peptide II). For this reason, the purpose of our study was to explain the causes of different interactions of the analogues with V2 receptors. The results have shown that both analogues display the tendency to adopt β‐turns in the 1–4 and 2–5 fragments, which is characteristic of OT and V1a receptors antagonists. In addition, the [Cpa1,(L‐1‐Nal)2]AVP (I) shows the propensity to assume β‐turn at position 7,8, which is believed to enhance antidiuretic activity, although not being crucial for its appearance. Moreover, the C‐terminal amide group seems to be crucial for signal transduction. Its high accessibility in [Cpa1,(L‐1‐Nal)2]AVP (I) in contrast to [Cpa1,(D‐1‐Nal)2]AVP (II), probably results in V2 receptor activation.
Analysis of the European captive Southern white rhinoceros Ceratotherium simum simum population using the International Studbook for the African White Rhinoceros (2001–2004) and integrating reproductive health findings
Authors: Reid C. E. , Versteege L. , Ludwig A. , Hermes R.
Published: February 2012

The goal of ex situ conservation is to maintain genetic diversity, avoid inbreeding and maximize equal representation of founder individuals. Analysis of a well‐maintained studbook yields important data concerning fertility and mortality that is invaluable to ex situ conservation. To evaluate the reproductive status of the European captive Southern white rhinoceros Ceratotherium simum simum population, basic demographics and population parameters were calculated using the International Studbook for the African White Rhinoceros Ceratotherium simum (2001–2004) data with the integration of recent scientific findings regarding reproductive health of individuals within the ‘reproductive age’. Kinship analysis of the 2001–2004 population was also performed to evaluate genetic diversity. Results indicated the population is declining 1·19 times faster than it is growing. To realize a 1% population increase at the 2001–2004 death rate, reproduction would have to increase by 214%. It is necessary to increase the genetically contributing subpopulation and to achieve a reproduction capacity that surpasses the rate currently possible with natural mating.
Reproductive characteristics ofNewWorld monkeys
Authors: Martin R. D.
Published: February 2012

Reproductive aspects ofNewWorld monkeys are reviewed in an evolutionary context. Molecular phylogenies clearly show that they are monophyletic. However, they also show that clawedNewWorld monkeys are not sister to all other platyrrhines. Instead, the first divergence separated titis, sakis and uakaris from all others. Some resulting cladistic classifications confusingly include clawedNewWorld monkeys inCebidae. Yet a classical grade‐based classification can maintain a division betweenCebidae andCallitrichidae (which are specialized evolutionary dwarfs). In molecular trees,Callimicoalso consistently nests within callitrichids, being more closely related to marmosets than tamarins. Ovarian cycles and gestation are reviewed, notably in comparison to the sister group (OldWorld monkeys, apes and humans).NewWorld monkeys similarly have invasive placentation and menstruation (albeit weakly evident in callitrichids).NewWorld monkeys are unusual among primates because ovarian cycle lengths are often reduced.Cebids have single births; but marmosets and tamarins show secondary evolution of multiple births, with a highly unusual shared placental circulation resulting in chimaerism. The lag phase in early gestation also shows secondary extension among callitrichids, includingCallimico. Multiple pregnancies were seemingly secondarily suppressed during evolution ofCallimicofrom an ancestor shared with marmosets.
Fulfilling the Promise: Creating a Child Development Research Agenda With Native Communities
Authors: Fitzgerald Hiram E. , Farrell Patricia
Published: February 2012

Abstract— The historic trauma of boarding schools and similar efforts to eradicate Native culture and identity had a profound effect on tribal family and community life. One result is that American Indian/Alaska Native families have largely been excluded from the child development research enterprise of the past 60 years. Creating a tribal applied developmental science has promise for advancing studies of American Indian/Alaska Native child development. Realizing the promise will depend on the extent to which investigators use community‐based participatory research strategies, embrace diversity in world views, emphasize cocreation of research designs and programs, and promote identity development through restoration and preservation of tribal culture and language.
Child Development Research in North American Native Communities—Looking Back and Moving Forward: Introduction
Authors: Sarche Michelle Christensen , Whitesell Nancy Rumbaugh
Published: February 2012

Abstract— The study of Native children’s development in the United States and Canada has lagged behind that of other populations. As a result, there is limited research literature to inform efforts to address the challenges faced by Native children and their families, including disparities in mental health problems such as substance abuse, suicide, mental disorders, and academic achievement. This article provides a brief overview of the historical context of children’s development in Native communities and introduces the Native Children’s Research Exchange (NCRE), formed in 2008 to facilitate child development research with tribal communities. The following collection of articles, written by NCRE scholars, reviews existing research, highlights challenges encountered in this work, and points to an agenda for furthering developmental research within Native cultures.
Dysphagia associated with presumed pharyngeal dysfunction in 16 neonatal foals
Authors: HOLCOMBE S. J. , HURCOMBE S. D. , BARR B. S. , SCHOTT II H. C.
Published: February 2012

Reasons for performing study:Dysphagia due to pharyngeal dysfunction occurs in human neonates and is associated with prematurity and hypoxic episodes. This syndrome probably occurs in neonatal foals but has not been reported.

Objectives:The objectives of this study were to describe 1) a series of neonatal foals with dysphagia due to pharyngeal dysfunction; 2) the progression, treatment and resolution of the dysphagia; 3) the comorbidities; and 4) the prognosis for life and athleticism for affected foals.

Methods:Records from 3 referral equine hospitals were reviewed from neonatal foals with dysphagia of pharyngeal origin. Inclusion criteria were a normal to strong suckle, dysphagia evidenced by milk at the nostrils after nursing the dam, and endoscopic examination of the airway. Foals with mechanical reasons for dysphagia, botulism or hyperkalaemic periodic paralysis were not included.

Results:Sixteen neonatal foals qualified for the study. Eight (50%) were premature and/or diagnosed with hypoxic ischaemic encephalopathy. Twelve (75%) had aspiration pneumonia. Fifteen foals were discharged alive from the hospital, nursing the mare with no evidence of dysphagia (n = 14), or mild dysphagia (n = 1), a mean ± s.d. of 7 ± 6 days (median = 6.3 days, range 0–22 days) after hospital admission. One foal was subjected to euthanasia in hospital. Follow‐up information was available for 14 animals. Thirteen of 16 (81%) were alive and included one yearling and 12 horses >2 years old. Seven of the 14 (50%) were racing, training or in work, and 6 horses were pets, breeding animals or had unknown athletic status. Two had laryngeal deficits. One foal was subjected to euthanasia within weeks of discharge from the hospital due to aspiration pneumonia.

Conclusion:Dysphagia related to pharyngeal dysfunction occurs in equine neonates and can resolve, but may require days to weeks of supportive care. Prognosis for life is favourable and for athleticism fair.
Treatment with histamine‐type 2receptor antagonists and omeprazole increase the risk of diarrhoea in neonatal foals treated in intensive care units
Authors: FURR M. , COHEN N. D. , AXON J. E. , SANCHEZ L. C. , PANTALEON L. , HAGGETT E. , CAMPBELL R. , TENNENT‐BROWN B.
Published: February 2012

Reasons for performing study:The use of anti‐ulcer medication in the neonatal intensive care unit (ICU) is common due to the concern for development of catastrophic gastric ulcer disease. In man, however, the use of acid‐suppressive medication has been shown in some studies to be a substantial risk factor for the development ofClostridium difficile‐associated diarrhoea (CDAD), bacteraemia and neonatal sepsis.

Objective:The purpose of the study reported herein is to evaluate the influence of anti‐ulcer medications on the development of diarrhoea in the neonatal foal.

Hypothesis:The use of anti‐ulcer medication does not alter the incidence of diarrhoea in foals treated in an ICU.

Methods:The records of 1710 foals from 6 different equine hospitals were examined and the use of anti‐ulcer drugs was recorded. The presence of in‐hospital acquired diarrhoea, CDAD,Clostridium perfringens‐associated diarrhoea, neonatal sepsis and salmonellosis were documented. In addition, the presence of gastric ulceration, duration of hospital stay and short‐term outcome were examined.

Results:The use of anti‐ulcer medications increased the odds of in‐hospital diarrhoea by 2.0 (95% CI 1.4–2.9; P<0.0001), relative to the use of no anti‐ulcer medication. There was no significant association of anti‐ulcer medication with CDAD (P = 0.3189) (OR 2.0; 95% CI 0.4–9.5). Further, results indicated that decreased prevalence of gastric ulceration was not associated with use of anti‐ulcer drugs among foals in the study for which these data were known (P = 0.5522).

Conclusions:Use of anti‐ulcer drugs increases the odds of developing diarrhoea, and may not reduce the incidence of gastric ulceration in hospitalised equine neonates.

Potential relevance:The use of anti‐ulcer drugs in neonatal foals being treated in a hospital setting should be carefully evaluated on an individual basis to determine if such use is warranted.
Energy expenditure of critically ill neonatal foals
Authors: JOSE‐CUNILLERAS E. , CORRADINI J. VIU, I. , ARMENGOU L. , CESARINI C. , MONREAL L.
Published: February 2012

Reasons for performing study:Nutritional support in critically ill neonatal foals is of great importance given their high metabolic rate and minimal stores of energy and protein. Nutrient requirements of healthy growing foals have been estimated based on daily milk intake; however, little is known about the resting energy expenditure (REE) of sick foals.

Objectives:To determine REE in critically ill neonatal foals (sepsis and/or hypoxic‐ischaemic encephalopathy [HIE] and compare this with REE in control foals.

Methods:Critically ill newborn foals admitted to the Fundació Hospital Clínic Veterinari, Universitat Autònoma de Barcelona, Spain from March 2009 to February 2011 were included in this study. Healthy neonatal foals and foals with nonsystemic conditions were used as controls. Oxygen consumption and CO2production were measured with a respiratory monitor connected to a tight fitting facemask and REE (kcal/kg bwt/day) was calculated with the abbreviated Weir formula. Measurements were performed within 24 h of admission and repeatedly during hospitalisation.

Results:Twenty‐seven foals were included (16 critically ill foals and 11 controls) and a total of 47 measurements were performed. In the critically ill, REE was reduced (mean ± s.e. 49.5 ± 2.1 kcal/kg bwt/day) on admission relative to the controls. In surviving foals (n = 5), REE before hospital discharge was not different (68.4 ± 7.0 kcal/kg bwt/day) from control foals (64.8 ± 2.7 kcal/kg bwt/day).

Conclusions:REE was lower in critically ill foals upon admission (40–50 kcal/kg bwt/day) and normalised before hospital discharge (60–80 kcal/kg bwt/day).

Potential relevance:Critically ill neonatal foals tolerating enteral feeding would receive approximately their REE when given 10% of their bodyweight in mare's milk daily. For sick neonates unable to tolerate enteral nutrition, provision of 50 kcal/kg bwt/day would be a reasonable goal for parenteral nutrition.
Endocrine adaptations in the foal over the perinatal period
Authors: FOWDEN A. L. , FORHEAD A. J. , OUSEY J. C.
Published: February 2012

In adapting to lifeex utero, the foal encounters a number of physiological challenges.It has to assume the nutritional, respiratory and excretory functions of the placenta and activate full regulatory control over its own internal environment for the first time.To achieve this, there must be structural and functional changes to a wide range of tissues including several endocrine glands. In most species, including the horse, these maturational changes begin in late gestation and continue into the first few days of neonatal life. Consequently, during this perinatal period, there are major changes in the sensitivity and/or set point of key endocrine axes, which alter the circulating hormone concentrations in the foal. In turn, these endocrine changes are responsible for many of the other physiological adaptations essential for neonatal survival. The perinatal alterations in the hypothalamic‐pituitary‐adrenal (HPA) axis are particularly important in these processes, although the sympatho‐adrenal medullary axis and endocrine pancreas also have key roles in ensuring homeostasis during the multiple novel stimuli experienced at birth. Abnormalities in the perinatal endocrine profile caused by adverse conditions before or after birth may, therefore, lead to maladaptation or aid survival of the newborn foal depending on the specific circumstances. This review examines the perinatal changes in endocrinology in normal and compromised foals and the role of these endocrine changes in the physiological adaptations to extrauterine life with particular emphasis on the HPA axis, adreno‐medullary catecholamines and the endocrine pancreas.
Influence of elevated liver fat on circulating adipocytokines and insulin resistance in obese Hispanic adolescents
Authors: Kim J. S. , Lê K.‐A. , Mahurkar S. , Davis J. N. , Goran M. I.
Published: February 2012

Objective

We performed this study to examine the metabolic differences arising from higher liver fat accumulation in obese Hispanic adolescents, with a particular focus on circulating levels of adipocytokines and insulin resistance.

Methods

Forty‐one obese Hispanic adolescents (15.3 ± 1.0 years, body mass index percentile: 97.0 ± 3.9) were assessed for: visceral adipose tissue (VAT), subcutaneous adipose tissue (SAT) and hepatic fat fraction (HFF) by magnetic resonance imaging; fasting measures of serum glucose, insulin and adipocytokines; homeostasis model assessment of insulin resistance (HOMA‐IR); and insulin sensitivity (SI) and the acute insulin response to glucose (AIR) by intravenous glucose tolerance test. Subjects with normal levels of HFF (below 5%; n = 25) were compared to those with HFF > 5% (n = 16).

Results

The two groups differing in HFF were similar for total body fat, VAT and SAT. The group with HFF > 5% had significantly (P < 0.05) higher interleukin‐8 (IL‐8) (6.1 ± 1.6 vs. 3.2 ± 0.4 pg mL−1), NGF (30.2 ± 9.9 vs. 13.9 ± 1.6 pg mL−1), HOMA‐IR (8.8 ± 1.1 vs. 5.5 ± 0.5), AIR (1869 ± 206 vs. 1092 ± 165) and a tendency for lower SI (1.2 ± 0.4 vs. 2.1 ± 0.3; P = 0.06), with no significant differences in any of other factors measured.

Conclusions

These data suggest that elevated liver fat is most closely associated with elevated serum IL‐8 and NGF levels as well as increased AIR and HOMA‐IR. These elevated factors may play significant roles in the metabolic abnormalities associated with elevated liver fat in obese Hispanics.
Velocity Profiles in a Cylindrical Liquid Jet by Reconstructed Velocimetry
Authors: Castrejón-Pita J. R. , Hoath S. D. , Hutchings I. M.
Published: February 2012

An experimental setup and a simple reconstruction method are presented to measure velocity fields inside slightly tapering cylindrical liquid jets traveling through still air. Particle image velocimetry algorithms are used to calculate velocity fields from high speed images of jets of transparent liquid containing seed particles. An inner central plane is illuminated by a laser sheet pointed at the center of the jet and visualized through the jet by a high speed camera. Optical distortions produced by the shape of the jet and the difference between the refractive index of the fluid and the surrounding air are corrected by using a ray tracing method. The effect of the jet speed on the velocity fields is investigated at four jet speeds. The relaxation rate for the velocity profile downstream of the nozzle exit is reasonably consistent with theoretical expectations for the low Reynolds numbers and the fluid used, although the velocity profiles are considerably flatter than expected.
Flow Analysis and Assessment of Loss Models in the Symmetric Volute of a Turbo-Blower
Authors: Kim Semi , Park Junyoung , Choi Bumseok , Baek Jehyun
Published: February 2012

The objectives of the present study were to investigate the flow structure and assess the accuracy of loss correlations in the symmetric volute of a turbo-blower using 3D steady flow analysis methods. To accurately model the flow field in the volute, an impeller with a single blade, a diffuser with 13 vanes, and a volute were used as the calculation domains for the computational fluid dynamics (CFD) simulations. Numerical results were validated by comparison with experimental results for the performance of a turbo-blower operated under three operating conditions: high (0.38 kg/s), normal (0.3 kg/s), and low (0.23 kg/s) mass flow rates. The accuracy of the loss correlation sets reported in four previous studies was compared with the CFD simulation predictions. These comparisons showed that the correlation sets did not accurately represent the total pressure loss in the symmetric volute of a turbo-blower, and a modified correlation set that included adjustments for the loss coefficients was proposed. Detailed investigations of the simulated flow fields were compared to understand the flow characteristics in the volute under the designed operating conditions.
Policies to Address Conflicts Between Passenger and Freight Rail Service in the U.S.
Authors: Guerrero Sebastian , Argote Juan , Carrel Andre , Mazare Pierre-Emmanuel
Published: February 2012

A renewed interest in expanding passenger service on rail in the US faces challenges and opportunities in that most of the railroads are privately owned. Up to this point railroad network capacity has kept up with demand relatively well. However, signs of strain are apparent looking into the future as freight volumes increase with globalization and conflicts with passenger trains increase with the addition of more intercity and commuter lines. Case studies were conducted to understand the relationship between passenger and freight operations in the US and to identify areas of conflict and opportunities for improvement. Common conflicts arise from differing objectives and include cost sharing, safety, liability and infrastructure needs. Currently, public agencies and railroad companies deal with these conflicts through an outdated regulatory framework that in many cases does not serve the interests of either party; improvements here are possible. Additionally, a greater use of hybrid agreements where government agencies fund capacity improvements for passenger and freight operations simultaneously may offer the best approach for dealing with these conflicts and adapting the rail network to meet demands into the future.
State Rail Plans: The Integration of Freight and Passenger Rail Planning
Authors: Keller Kevin
Published: February 2012

The Passenger Rail Investment and Improvement Act of 2008 (PRIIA) was created to reauthorize the National Railroad Passenger Corporation, better known as Amtrak, and strengthen the US passenger rail network by tasking Amtrak, the U.S. Department of Transportation (US DOT), Federal Railroad Administration (FRA), States, and other stakeholders in improving service, operations, and facilities. PRIIA also tasks States with establishing or designating a State rail transportation authority that will develop Statewide rail plans to set policy involving freight and passenger rail transportation within their boundaries, establish priorities and implementation strategies to enhance rail service in the public interest, and serve as the basis for Federal and State rail investments within the State. In order to comply with PRIIA, State rail plans are required to address a broad spectrum of issues, including an inventory of the existing rail transportation system, rail services and facilities within the State. They must also include an explanation of the State’s passenger rail service objectives, an analysis of rail’s transportation, economic, and environmental impacts in the State, and a long-range investment program for current and future freight and passenger infrastructure in the State. The plans are to be coordinated with other State transportation planning programs and clarify long-term service and investment needs and requirements. This paper and presentation will illustrate the steps required in preparing a State rail plan and the benefits of having a properly developed plan.
Examination of Vehicle Performance at High Speed and High Cant Deficiency
Authors: Marquis Brian , LeBlanc Jon , Tajaddini Ali
Published: February 2012

In the US, increasing passenger speeds to improve trip time usually involves increasing speeds through curves. Increasing speeds through curves will increase the lateral force exerted on track during curving, thus requiring more intensive track maintenance to maintain safety. These issues and other performance requirements including ride quality and vehicle stability, can be addressed through careful truck design. Existing high-speed rail equipment, and in particular their bogies, are better suited to track conditions in Europe or Japan, in which premium tracks with little curvature are dedicated for high-speed service. The Federal Railroad Administration has been conducting parametric simulation studies that examine the performance of rail vehicles at high speeds (greater than 90 mph) and at high cant deficiency (greater than 5 inches). The purpose of these analyses is to evaluate the performance of representative vehicle designs subject to different combinations of track geometry variations, such as short warp and alinement.
Preliminary Results of the Trespass Prevention Research Study in West Palm Beach, Florida
Authors: daSilva Marco , Carroll Anya
Published: February 2012

The United States Department of Transportation’s (US DOT) Research and Innovative Technology Administration’s John A. Volpe National Transportation Systems Center (Volpe Center), under the direction of the US DOT Federal Railroad Administration (FRA) Office of Research and Development (R&D), is conducting a Trespass Prevention Research Study (TPRS) in the city of West Palm Beach, Florida. The main objective of this research is to demonstrate potential benefits, including documenting best practices and lessons learned, of implementation and evaluation of trespass prevention strategies on the rail network in West Palm Beach, Florida and all of its rights-of-way. This technical paper will describe and provide the most up-to-date results from this study, which is beginning its second year of a three year study period. The cumulative results of the trespass prevention strategies will be analyzed to better inform the determination of areas of potential risk, develop solutions to prevent and minimize risk exposure and implement successful countermeasures in the future. Preliminary analysis from the WPB corridor trespass prevention activities are described in this technical paper. The ultimate objective of the research is to aid in the development of national recommendations or guidelines for reducing trespass-related incidents and fatalities.
High-Speed Frame Grabber for Track Monitoring Systems
Authors: Liu Yu-Wei , Hsieh Hsiang-Yu , Chen Nanming
Published: February 2012

In recent years, image recognition, along with improvements in image processing technology, has become a mainstream method of object inspection. The quality of images directly affects the image-recognition rate. Track monitoring systems play an important role in ensuring safety and preventing derailments of trains, on the basis of the prevailing track conditions. Therefore, the conditions of track systems are very important. In this research, a high-speed frame grabber system is designed. The triggering rate of its line scan camera can be adjusted to match the vehicle speed of the train, so that the pixels per inch of images captured by this camera are fixed. The hardware equipment of the designed system includes a line scan camera, an image acquisition card, artificial lightings, a contrast sensor, and a system on a programmable chip (SOPC) development board. An exposure time control system is designed on the basis of a field-programmable gate array (FPGA) core. The designed system can acquire clear high-speed images while the vehicle speed changes dramatically. The experimental results confirm the feasibility of using line scan cameras for railway vehicles.
Dynamic Actuation of a Multiple Memory Material Processed Nitinol Linear Actuator
Authors: Pequegnat A. , Vlascov M. , Daly M. , Zhou Y. , Khan M. I.
Published: February 2012

Shape memory alloys such as Nitinol, which is a group of NiTi alloys composed of nearly equiatomic nickel and titanium, finds increasing applications in many industries because of its unique properties including the shape memory effect and pseudoelasticity. In past work simple linear actuators have been developed using Nitinol wire which are actuated and controlled using resistive heating. However, traditional Nitinol materials are batch processed and a monolithic component only possesses a single set of transformation temperatures, limiting the functionality of the actuator. In this work a linear actuator processed using the novel multiple memory material processing technology is presented showing multiple transformations and dynamic actuation by resistive heating. This dynamically controlled actuation greatly improves the functionality of the Nitinol actuator allowing for the realization of new applications and improved control methods. The different transformation temperatures embedded in the monolithic wire actuator following processing are identified using thermo-analytical analysis and the dynamic application of load and displacement are presented using a custom test set-up.
Modeling of Piezoelectric Energy Harvester: A Comparison Between Euler-Bernoulli Theory and Timoshenko Theory
Authors: Zhu Yang , Zu Jean W. , Yao Minghui
Published: February 2012

Harvesting vibration energy using piezoelectric materials has gained considerable attention over the past few years. Typically, a piezoelectric energy harvester is a unimorph or bimorph cantilevered beam which undergoes base vibration. The focus of this paper is to compare the Euler-Bernoulli model and the Timoshenko model, which are both used for modeling the vibration-based energy harvester. Procedures of deriving the electro-mechanical equation of motion are provided, following exact expressions for the electrical output in two models. Parametric case studies are carried out in order to compare the frequency response of two models. Simulation results show that there is a great difference between Euler-Bernoulli model and Timoshenko model at low length-to-thickness aspect ratio. Such difference diminishes and becomes negligible as aspect ratio increases. It is shown that for the design of piezoelectric energy harvester with small aspect ratio, Timoshenko model can be more accurate than Euler-Bernoulli model in predicting the system behavior.
Simultaneous Measurement of Deformation and Fracture of Composite Structures Using Fiber Bragg Grating Sensors
Authors: Kim Hong-Il , Han Jae-Hung , Bang Hyung-Joon , Kim Soo-Hyun , Lee Bongwan
Published: February 2012

Because of high specific strength and many other benefits, the use of composites for the large lightweight structures such as modern aircrafts and wind turbines are increasing. However, one of the serious drawbacks of composites is that the structural failure occurs in complex patterns without yielding. Therefore, structural health monitoring has been intensively investigated for the early detection of any problems in structural integrity. One of the promising sensors for this purpose is fiber Bragg grating (FBG) sensor. They can be easily inserted into the layered-structure of the composite materials due to their small size. The excellent multiplexing capability enables measurement to be taken at multiple points along a single sensor line. As well as damage detection, the structural shape measurement also draws attention. Particularly for structures experiencing aerodynamic forces such as wind turbines or helicopter blades, the structural shape itself is important because the applied aerodynamic forces are affected by structural shape deflections. Therefore, the authors have conducted a series of studies on the structural shape estimation of various structures. We have also developed a wavelength division multiplexing (WDM) Bragg grating sensing system for high speed strain sensing as well as low frequency dynamic strains. In the case of high-speed sensing, the interrogator allows a sampling ratio of over 40 kHz for six linearly arrayed FBG sensors per channel. Utilizing the developed interrogator, this paper presents some experimental results for simultaneous measurement of deformation and fracture signals of composite structures. An array of FBG sensors were installed onto composite beam specimens and the acoustic emission (AE) signals due to structural failure was continuously monitored while the overall structural deflection shape was monitored in real time. The reconstructed shapes of the specimens were in good agreement with the shapes captured from photographs taken with a high-speed camera. In summary, it was demonstrated that both fracture signals and the overall deformation shape of composite structures could be simultaneously monitored.
Improvements to the Kiefer and Lagoudas Model for Prediction of the Magneto-Mechanical Behavior of Magnetic Shape Memory Alloys
Authors: Waldauer Alex , Feigenbaum Heidi P. , Bruno Nickolaus M. , Ciocanel Constantin
Published: February 2012

Magnetic shape memory alloys (MSMAs) are a class of materials that exhibit large, recoverable inelastic strain. After cooling from austenite to martensite, MSMAs have a tetragonal crystalline structure with three possible orientations called variants. These variants can rotate as a result of applied stress or applied magnetic field and the resulting inelastic strain can be as high as 10% [1]. To effectively use MSMAs in any potential application, a model that can accurately predict the magneto-mechanical behavior of the MSMA is required. Kiefer and Lagoudas developed a thermodynamic basis for modeling MSMAs and then apply it in the case where two of the three martensitic variants exist [2]. The improvements to the Kiefer and Lagoudas model proposed in this paper include a different analysis of the demagnetizing effect and an inclusion of the resulting axial demagnetizing field.
Simulation and Control Design for Shape Memory Alloy Torque Tubes
Authors: Friedman David H. , Bieniawski Stefan , Hartl Darren
Published: February 2012

Shape Memory Alloy (SMA) driven actuation devices offer the potential for dramatic improvements in flight vehicle performance. Such actuators are ideally suited for the light-weight, low-bandwidth, compact size requirements associated with small changes in the vehicle geometry to enhance performance. Over the last 10+ years SMA-based actuation concepts have been considered for use on commercial aircraft, military aircraft, rotorcraft, and spacecraft. Many of these actuation concepts are driven by twisting SMA tubes which are under variable shear loading. This work extends previous quasi-static modeling work to provide a time-domain coupled thermo-mechanical model for SMA torque tubes. The model includes states associated with the material and states associated with peripheral dynamic systems, such as the heater. Approaches for obtaining the key parameters required by the model directly from experimental data are then described. Steps for developing controllers using these models are then reviewed including linearization and linear quadratic regulator (LQR) based control synthesis. The controller is implemented and tested in closed-loop position tracking experiments. These are completed in a lab setting and the results indicate a robust (in terms of gain and phase margin) and high-performance (in terms of settling time) tracking controller. The complete sequence described in this work illustrates the potential of model based optimal control applied to Shape Memory Alloy torque tubes.
Predictive Modeling of Space Structures for SHM With PWAS Transducers
Authors: Gresil Matthieu , Lin Bin , Shen Yanfeng , Giurgiutiu Victor
Published: February 2012

This paper presents an investigation of predictive modeling of space structures for structural health monitoring (SHM) with piezoelectric wafer active sensors (PWAS) transducers. The development of a suitable SHM system for complex space structure is not trivial; creating a robust SHM capability requires at least: (a) flexible accommodation of numerous configurations; (b) detection of damage in complex multifunctional structures; (c) identification if mechanical interfaces are properly connected. To realize this, we propose a predictive modeling approach using both analytical tools and finite element method (FEM) to study the health status of the structure, the power and energy transduction between the structure and the PWAS. After a review of PWAS principles, the paper discusses the modeling and the power and energy transduction between structurally guided waves and PWAS. The use of guided wave (GW) and the capability of embedded PWAS to perform in situ nondestructive evaluation (NDE) are explored. FEM codes are used to simulate GW of 2D and 3D space structure using the commercials software ABAQUS. PWAS transducers placement at different location on a flat plate and on an isogrid panel was simulated. The signal scattered by a crack emerging from the hole is simulated. Predictive modeling of power and energy transduction is discussed using an analytical approach. This model of 2-D power and energy transduction of PWAS attached to structure allows examination of power and energy flow for a circular crested wave pattern. Wave propagation method for an infinite boundary plate, electromechanical energy transformation of PWAS and structure, and wave propagation energy spread out in 2-D plate are considered. The parametric study of PWAS size, impedance match gives the PWAS design guideline for PWAS sensing and power harvesting applications.
Experimental Investigation of the Transient Behavior of MR Fluids
Authors: Maas Ju¨rgen , Gu¨th Dirk
Published: February 2012

The transient behavior of MRF actuators is an important property for certain applications that is mainly affected by three delays, occurring from the dynamic properties of the coil current, the magnetic field and the torque generation by the MRF. In order to investigate the transient behavior of the generated torque with respect to the magnetic field, which is mainly affected by the motion of the MR particles in the carrier fluid, the mentioned response time of the electrical and magnetic domains must be in an appropriated ratio in comparison to the MRF response time to obtain reliable results by experiments. Therefore a special disc-type test actuator with outstanding dynamics is designed that minimizes the delays by the use of an ultrafast current control and a magnetic core made of soft ferrite material for preventing the effects of eddy currents. For the experimental investigation of the transient behavior of MR fluids, the small signal as well as the large signal behavior is analyzed for different test signals and load conditions of the actuator. Various results of the investigated transient behavior are shown finally for two different MR fluids featuring response times of about 1 ms for the fluid itself and switching times of about 4 ms for the MRF actuator.